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1

Correction for Thermal EMFs in Thermocouple Feedthroughs  

NASA Technical Reports Server (NTRS)

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.

Ziemke, Robert A.

2006-01-01

2

Anomalous increase of the thermal emf in epitaxial graphene on size-quantized films  

NASA Astrophysics Data System (ADS)

The thermoelectric effect in epitaxial graphene formed on the surface of a size-quantized metal film is examined in the context of a Davydov model. An approach based on the Kubo formula for the conductivity and differential thermal emf is used. It is shown that because of size quantization, near the edges of the energy levels the thermal emf of epitaxial graphene increases to gigantic values of 200 ?V/K, or almost a factor of seven greater than the emf of isolated graphene (about 30 ?V/K).

Alisultanov, Z. Z.; Mirzegasanova, N. A.

2014-05-01

3

Measurement of absolute thermoelectric power by photoemission  

NASA Astrophysics Data System (ADS)

It is pointed out that a determination of the temperature dependence of the Fermi cutoff in the conduction band of a metal provides a means of measuring the thermal emf of a single metal, as well as the absolute thermoelectric power, without use of a reference substance. The energy of the Fermi cutoff is determined by photoemission. The method is illustrated by a crude determination of the thermal emfs of copper and constantan.

Wertheim, G. K.; Buchanan, D. N. E.

1991-12-01

4

Absolute Thermal SST Measurements over the Deepwater Horizon Oil Spill  

NASA Astrophysics Data System (ADS)

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.

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

2010-12-01

5

Absolute Thermal SST Measurements over the Deepwater Horizon Oil Spill  

Microsoft Academic Search

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

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

2010-01-01

6

Appearance of thermochemical emf in some conducting materials  

SciTech Connect

The appearance of an emf in conductors when they are heated is described by the Seebeck and Thompson effects. If some part of the surface of a conductor is covered by a pyrotechnical material and ignited, then while the pyrotechnical material is burning and after it has burned, an emf arises at the ends of the conductor. The direction of the emf depends on the location of maximum temperature of the heated section of the conductor. If the heating is terminated for some time and started up again, then the emf and current appear again, with no necessity for re-application of the pyrotechnical material. Conductors of Nichrome, Constantan and tungsten, as well as graphite rods were studied with small sections of the conductors covered with lead azide, black gunpowder, or match-head composition. The current ranged from -5 to 6 microamps, and the emf from -0.4 to 1 millivolt. The effects described can be used to convert thermal energy into electrical energy in sensors, etc.

Petrov, Y.S.; Maslikhov, V.V.; Shcheglov, V.D.

1983-05-01

7

Significant RF-EMF and thermal levels observed in a computational model of a person with a tibial plate for grounded 40?MHz exposure.  

PubMed

Using numerical modeling, a worst-case scenario is considered when a person with a metallic implant is exposed to a radiofrequency (RF) electromagnetic field (EMF). An adult male standing on a conductive ground plane was exposed to a 40?MHz vertically polarized plane wave field, close to whole-body resonance where maximal induced current flows are expected in the legs. A metal plate (50-300?mm long) was attached to the tibia in the left leg. The findings from this study re-emphasize the need to ensure compliance with limb current reference levels for exposures near whole-body resonance, and not just rely on compliance with ambient electric (E) and magnetic (H) field reference levels. Moreover, we emphasize this recommendation for someone with a tibial plate, as failure to comply may result in significant tissue damage (increases in the localized temperature of 5-10?°C were suggested by the modeling for an incident E-field of 61.4?V/m root mean square (rms)). It was determined that the occupational reference level for limb current (100?mA?rms), as stipulated in the 1998 guidelines of the International Commission on Non-Ionizing Radiation Protection (ICNIRP), is satisfied if the plane wave incident E-field levels are no more than 29.8?V/m?rms without an implant and 23.4?V/m?rms for the model with a 300?mm implant. PMID:24578303

McIntosh, Robert L; Iskra, Steve; Anderson, Vitas

2014-05-01

8

The measurement of absolute thermal neutron flux using liquid scintillation counting techniques  

E-print Network

factor for flux depression due to a neutron absorbing indium foil. Later Tittle (2, 3) studied the same problem and extended Bothe's re- sults to a more useful form. To minimize flux depression and also the self absorption of the induced radioactivity... of the foil, the use of very thin foils has become a standard practice . Greenfield et al . (4) have described in detail the conventional techniques for measuring absolute thermal neutron flux with thin indium foils. The authors discuss the importance...

Walker, Jack Vernon

2012-06-07

9

Securing insurance coverage for EMF claims  

SciTech Connect

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.

Meyer, K.A. (Paul, Hatings, Janofsky Walker, Los Angeles, CA (United States))

1992-02-15

10

Modeling emf, Potential Difference, and Internal Resistance  

NSDL National Science Digital Library

Through class discussion and think-pair-share questions, this activity helps students come to understand the difference between emf and potential difference in electrical circuits. These concepts are broached within the context of internal resistance of batteries.

Steven Maier

11

Biogenic Magnetite and EMF Effects  

NASA Astrophysics Data System (ADS)

Magnetite biomineralization is a genetically-controlled biochemical process through which organisms make perfect ferrimagnetic crystals, usually of single magnetic domain size. This process is an ancient one, having evolved about 2 billion years ago in the magnetotactic bacteria, and presumably was incorporated in the genome of higher organisms, including humans. During this time, DNA replication, protein synthesis, and many other biochemical processes have functioned in the presence of strong static fields of up to 400 mT adjacent to these magnetosomes without any obvious deleterious effects. Recent behavioral experiments using short but strong magnetic pulses in honeybees and birds demonstrates that ferromagnetic materials are involved in the sensory transduction of geomagnetic field information to the nervous system, and both behavioral and direct electrophysiological experiments indicate sensitivity thresholds to DC magnetic fields down to a few nT. However, far more biogenic magnetite is present in animal tissues than is needed for magnetoreception, and the biological function of this extra material is unknown. The presence of ferromagnetic materials in biological systems could provide physical transduction mechanisms for ELF magnetic fields, as well for microwave radiation in the .5 to 10 GHz band where magnetite has its peak ferromagnetic resonance. Elucidation of the cellular ultrastructure and biological function(s) of magnetite might help resolve the question of whether anthropogenic EMFs can cause deleterious biological effects. This work has been supported by grants from the NIH and EPRI.

Kirschvink, Joseph L.

1996-03-01

12

Induced EMF in a coil of wire  

NSDL National Science Digital Library

Students use a simple set up consisting of a coil of wire and a magnet to visualize induced EMF. First, students move a coil of wire near a magnet and observe the voltage that results. They then experiment with moving the wire, magnet, and a second, current carrying coil. Students connect the coil to a circuit and the current from the induced EMF charges a conductor.

VU Bioengineering RET Program, School of Engineering,

13

Methodological approach to EMF protection standards  

NASA Astrophysics Data System (ADS)

Biological and health effects of electromagnetic fields (EMF) have been investigated for many years. Exposure standards have been developed internationally, that provide adequate protection against all known adverse effects of exposure to EMF. The guidelines developed by the International Commission on Non Ionizing Radiation Protection (ICNIRP) are widely recognized and have formed the basis for national regulations in several countries. Concerns for hypothesized, but unproven, long-term effects of chronic exposure to low-level EMFs have created a demand for precautionary measures beyond the standards for recognized, acute effects. However, such measure should be separate from exposure standards, and adopted with special care to avoid undermining the credibility of science-based guidelines, and of health protection agencies.

Vecchia, Paolo

2010-04-01

14

High accuracy, self-calibrating photopyroelectric device for the absolute determination of thermal conductivity and thermal effusivity of liquids  

NASA Astrophysics Data System (ADS)

An improved photopyroelectric approach to simultaneously determine the thermal conductivity and thermal effusivity of minute quantities of liquids, which is based on a combined scan of the modulation frequency and the piston-sensor distance, is presented. A thorough sensitivity analysis and statistical analysis of the fitting uncertainties show that the method is a very accurate tool for the simultaneous determination of the thermal conductivity and thermal effusivity of liquid samples.

Menon, Preethy Chirukandath; Rajesh, Ravindran Nair; Glorieux, Christ

2009-05-01

15

Absolute thermal expansion of copper and aluminum between 5 K and 330 K  

SciTech Connect

Theoretical and experimental results of experiments on thermal expansion of Al and Cu are presented. Experimental apparatus and procedures are described. Results are presented in graphs and plots and discussed. (JRD)

Kroeger, F.R. Jr.

1976-02-01

16

Absolute induction angiometer.  

PubMed

The objective of this method is the continuous recording of vascular diameters and their measurement in absolute terms. This can be accomplished by percutaneously introduced intravascular sensors (IVS) or surgically implanted perivascular sensors (PVS). Both types of sensor are made of bifilar insulated wires forming a bifilar loop. One wire of the bifilar loop acts as a transformer primary inducing an electromotive force (EMF) in the secondary loop wire. The latter EMF is a measure of the vascular diameter. The IVS loop is made of resilient wire and is disposed across a vascular diameter in the central plane of a blood vessel. The sensitivity is such that phasic variations of a few micrometers in the diameter of a major blood vessel (such as the aorta or a coronary artery) can be measured and recorded. The surgically implanted perivascular loop sensor permits observation of vasomotion in a conscious, unrestrained animal. Both IVS and PVS permit observation of coronary vasomotion in the beating heart. Unlike the relative induction angiometer, the present device does not require an extracorporeal magnet. PMID:7362877

Kolin, A

1980-01-01

17

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

PubMed Central

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

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

2014-01-01

18

Dissociative recombination of the deuterated acetaldehyde ion, CD3CDO(+): product branching fractions, absolute cross sections and thermal rate coefficient.  

PubMed

Dissociative recombination of the deuterated acetaldehyde ion CD3CDO(+) has been studied at the heavy-ion storage ring CRYRING, located at the Manne Siegbahn Laboratory, Stockholm, Sweden. Product branching fractions together with absolute DR cross-sections were measured. The branching fractions were determined at a relative collision energy between the ions and the electrons of approximately 0 eV. With a probability of 34% the DR events resulted in no ruptures of bonds between heavy atoms (i.e. no breakage of the C-C bond or the C[double bond, length as m-dash]O bond). In the remaining 66% of the events one of the bonds between the heavy atoms was broken. The energy-dependent cross-section for the DR reaction was measured between approximately 0 and 1 eV relative kinetic energy. In the energy region between 1 meV and 0.2 eV the absolute cross section could be fitted by the expression sigma(E) = 6.8 x 10(-16)E(-1.28) cm(2), whereas in the energy interval between 0.2 and 1 eV the data were best fitted by sigma(E) = 4.1 x 10(-16)E(-1.60) cm(2). From these cross section data the thermal rate coefficient (as a function of the electron temperature), alpha(T) = 9.2 x 10(-7) (T/300)(-0.72) cm(3) s(-1) was obtained. PMID:17538730

Vigren, Erik; Kami?ska, Magdalena; Hamberg, Mathias; Zhaunerchyk, Vitali; Thomas, Richard D; Semaniak, Jacek; Danielsson, Mathias; Larsson, Mats; Geppert, Wolf D

2007-06-14

19

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

SciTech Connect

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.

T. Dan Bracken, Inc.

1997-04-01

20

EMF monitoring-concepts, activities, gaps and options.  

PubMed

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

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

2014-09-01

21

Exposure Knowledge and Risk Perception of RF EMF  

PubMed Central

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

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

2015-01-01

22

Human health effects of EMFs: The cost of doing nothing  

NASA Astrophysics Data System (ADS)

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.

Carpenter MD, David O.

2010-04-01

23

Integrated analysis software for grounding, EMF, and EMI  

Microsoft Academic Search

The current distribution, electromagnetics, grounding, and soil structure analysis (CDEGS) software package for studying problems that involve power system electromagnetic fields (EMFs), electromagnetic interference (EMI), and grounding is described. This package includes three input processors, six engineering applications modules, and six output processors. The relationship between these modules and processors is illustrated. A case study of the inductive interference between

F. P. Dawalibi; F. Donoso

1993-01-01

24

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

Thermal Imaging in the Chemistry Laboratory Thermal imaging devices take advantage of the fact in temperature. This process uses the fact that the amount of radiation emitted by an object is proportional

Short, Daniel

25

Review of the epidemiologic literature on EMF and Health.  

PubMed Central

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

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

2001-01-01

26

Three-phase power factor controller with induced EMF sensing  

NASA Technical Reports Server (NTRS)

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.

Nola, F. J. (inventor)

1984-01-01

27

Absolute Zero  

NASA Astrophysics Data System (ADS)

Absolute Zero is a two hour PBS special attempting to bring to the general public some of the advances made in 400 years of thermodynamics. It is based on the book “Absolute Zero and the Conquest of Cold” by Tom Shachtman. Absolute Zero will call long-overdue attention to the remarkable strides that have been made in low-temperature physics, a field that has produced 27 Nobel Prizes. It will explore the ongoing interplay between science and technology through historical examples including refrigerators, ice machines, frozen foods, liquid oxygen and nitrogen as well as much colder fluids such as liquid hydrogen and liquid helium. A website has been established to promote the series: www.absolutezerocampaign.org. It contains information on the series, aimed primarily at students at the middle school level. There is a wealth of material here and we hope interested teachers will draw their student’s attention to this website and its substantial contents, which have been carefully vetted for accuracy.

Donnelly, Russell J.; Sheibley, D.; Belloni, M.; Stamper-Kurn, D.; Vinen, W. F.

2006-12-01

28

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

SciTech Connect

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.

Wilson, B.W.

1992-06-01

29

Dissociative recombination of fully deuterated protonated acetonitrile, CD3CND+: product branching fractions, absolute cross section and thermal rate coefficient.  

PubMed

The dissociative recombination of fully deuterated protonated acetonitrile, CD(3)CND(+), has been investigated at the CRYRING heavy ion storage ring, located at the Manne Siegbahn Laboratory, Stockholm, Sweden. Branching fractions were measured at approximately 0 eV relative collision energy between the ions and the electrons and in 65% of the DR events there was no rupture of bonds between heavy atoms. In the remaining 35%, one of the bonds between the heavy atoms was broken. The DR cross-section was measured between approximately 0 eV and 1 eV relative collision energy. In the energy region between 1 meV and 0.1 eV the cross section data were best fitted by the expression sigma = 7.37 x 10(-16) (E/eV)(-1.23) cm(2), whereas sigma = 4.12 x 10(-16) (E/eV)(-1.46) cm(2) was the best fit for the energy region between 0.1 and 1.0 eV. From the cross section a thermal rate coefficient of alpha(T) = 8.13 x 10(-7) (T/300)(-0.69) cm(3) s(-1) was deduced. PMID:18597015

Vigren, Erik; Kami?ska, Magdalena; Hamberg, Mathias; Zhaunerchyk, Vitali; Thomas, Richard D; Danielsson, Mathias; Semaniak, Jacek; Andersson, Patrik U; Larsson, Mats; Geppert, Wolf D

2008-07-21

30

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

NASA Technical Reports Server (NTRS)

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.

Howard, David E. (Inventor)

2000-01-01

31

EMF1 and PRC2 cooperate to repress key regulators of Arabidopsis development.  

PubMed

EMBRYONIC FLOWER1 (EMF1) is a plant-specific gene crucial to Arabidopsis vegetative development. Loss of function mutants in the EMF1 gene mimic the phenotype caused by mutations in Polycomb Group protein (PcG) genes, which encode epigenetic repressors that regulate many aspects of eukaryotic development. In Arabidopsis, Polycomb Repressor Complex 2 (PRC2), made of PcG proteins, catalyzes trimethylation of lysine 27 on histone H3 (H3K27me3) and PRC1-like proteins catalyze H2AK119 ubiquitination. Despite functional similarity to PcG proteins, EMF1 lacks sequence homology with known PcG proteins; thus, its role in the PcG mechanism is unclear. To study the EMF1 functions and its mechanism of action, we performed genome-wide mapping of EMF1 binding and H3K27me3 modification sites in Arabidopsis seedlings. The EMF1 binding pattern is similar to that of H3K27me3 modification on the chromosomal and genic level. ChIPOTLe peak finding and clustering analyses both show that the highly trimethylated genes also have high enrichment levels of EMF1 binding, termed EMF1_K27 genes. EMF1 interacts with regulatory genes, which are silenced to allow vegetative growth, and with genes specifying cell fates during growth and differentiation. H3K27me3 marks not only these genes but also some genes that are involved in endosperm development and maternal effects. Transcriptome analysis, coupled with the H3K27me3 pattern, of EMF1_K27 genes in emf1 and PRC2 mutants showed that EMF1 represses gene activities via diverse mechanisms and plays a novel role in the PcG mechanism. PMID:22457632

Kim, Sang Yeol; Lee, Jungeun; Eshed-Williams, Leor; Zilberman, Daniel; Sung, Z Renee

2012-01-01

32

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

SciTech Connect

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.

Enertech Consultants

1996-04-01

33

Discussion of an EMF (electric and magnetic field) protocol  

SciTech Connect

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.

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

1990-07-01

34

The EMF dilemma: Decision-making amid scientific uncertainty  

SciTech Connect

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.

Sage, C. (Sage Associates, Montecito, CA (USA))

1991-04-01

35

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

PubMed Central

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.

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

2014-01-01

36

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

PubMed

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. In vitro 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

D'Angelo, C; Costantini, E; Kamal, M A; Reale, M

2015-01-01

37

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

SciTech Connect

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.

Moore, T. (Electric Power Research Inst., Palo Alto, CA (United States))

1992-03-01

38

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

PubMed Central

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

2012-01-01

39

Teaching Absolute Value Meaningfully  

ERIC Educational Resources Information Center

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…

Wade, Angela

2012-01-01

40

EMF 7 model comparisons: key relationships and parameters  

SciTech Connect

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.

Hickman, B.G.

1983-12-01

41

Nuclear Energy Response in the EMF27 Study  

SciTech Connect

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.

Kim, Son H. [Joint Global Change Research Institute, College Park, MD (United States); Wada, Kenichi [Research Inst. of Innovative Technology for the Earth, Kizagawa-Shi, Kyoto (Japan); Kurosawa, Atsushi [Inst. of Applied Energy, Minato-ku, Tokyo (Japan ); Roberts, Matthew [Stanford University, Stanford, CA (United States)

2014-02-28

42

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

PubMed

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

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

2014-06-01

43

Extremely low frequency electromagnetic fields (EMF) and brain cancer in adults and children: review and comment.  

PubMed Central

Epidemiologic and experimental research on the potential carcinogenic effects of extremely low frequency electromagnetic fields (EMF) has now been conducted for over two decades. Cancer epidemiology studies in relation to EMF have focused primarily on brain cancer and leukemia, both from residential sources of exposure in children and adults and from occupational exposure in adult men. Because genotoxic effects of EMF have not been shown, most recent laboratory research has attempted to show biological effects that could be related to cancer promotion. In this report, we briefly review residential and occupational EMF studies on brain cancer. We also provide a general review of experimental studies as they relate both to the biological plausibility of an EMF-brain cancer relation and to the insufficiency of such research to help guide exposure assessment in epidemiologic studies. We conclude from our review that no recent research, either epidemiologic or experimental, has emerged to provide reasonable support for a causal role of EMF on brain cancer. PMID:11550314

Gurney, J. G.; van Wijngaarden, E.

1999-01-01

44

Contributing to a precise and accurate chronostratigraphic time scale for climatic records: Absolute dating and paleomagnetism in lavas  

NASA Astrophysics Data System (ADS)

Understanding climatic mechanisms requires a robust and precise timescale allowing long-distance and multi-archives correlations. A unique tool to construct such time scales is provided by the Earth magnetic field (EMF), which is independent from climatic variations and the past evolution of which is recorded in most of the geological/climatic archives. Sedimentary sequences provide continuous records of relative intensities of the EMF on stratigraphic time scales, usually based on orbital tuning. They are transferred onto absolute intensity scale and chronological time scale using robust tie points available for the past ~40 ka. However, for older periods this calibration remains poorly constrained. Our study reports on new tie points over the last 200 ka by combining paleomagnetic and geochronological (K/Ar and 40Ar-39Ar dating) studies on lavas. Based on the K-Ar LSCE age database, a set of 18 lava flows corresponding to potential geomagnetic excursions and/or highs and lows in the paleomagnetic intensity as observed from sediments and occurring in the studied time-window were selected in the Canary Islands (Tenerife, La Palma and Gran Canaria). A total of 205 oriented cores were taken from these 18 lava flows. Rock magnetic experiments include thermomagnetic analyses on each core, hysteresis loop and First Order Reversal Curves. Stepwise thermal demagnetizations in zero-field provided reliable mean-site paleomagnetic direction of the EMF for 15 of the flows. Paleointensity values were determined using the original Thellier and Thellier method. Based on previous experiments, 170 samples were analyzed, among which 51% provided reliable paleointensity values (determined using PICRIT-03 criteria). The geochronological study focused on 40Ar-39Ar dating. Based on preliminary paleomagnetic results, 13 flows were analyzed and 11 provided ages consistent at the 2 sigma level with the already available K-Ar ages. This coupled K/Ar - 40Ar-39Ar results strongly constrain the chronological framework. The new obtained paleomagnetic/age data will be compared to both sedimentary and volcanic data base.

Sasco, Romain; Guillou, Herve; Kissel, Catherine; Wandres, Camille; Carracedo, Juan-Carlos; Perez Torrado, Francisco Jose

2014-05-01

45

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

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

46

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

NASA Astrophysics Data System (ADS)

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.

Grigoriev, Yury

2010-04-01

47

A Thermal-Diffusivity-Based Frequency Reference in Standard CMOS With an Absolute Inaccuracy of 0.1% From 55 C to 125 C  

Microsoft Academic Search

An on-chip frequency reference exploiting the well-defined thermal-diffusivity (TD) of IC-grade silicon has been realized in a standard 0.7 ?m CMOS process. A frequency-locked loop (FLL) locks the frequency of a digitally controlled oscillator (DCO) to the process-insensitive phase shift of an electrothermal filter (ETF). The ETF's phase shift is determined by its geometry and by the thermal diffusivity of

S. Mahdi Kashmiri; Michiel A. P. Pertijs; Kofi A. A. Makinwa

2010-01-01

48

Absolute nuclear material assay  

DOEpatents

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.

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

2012-05-15

49

Absolute values of specific heat capacity and thermal conductivity of liquids from different modes of operation of a simple photopyroelectric setup  

Microsoft Academic Search

Photothermal techniques offer a nice tool for the determination of changes in thermal parameters of different types of samples. Using a very thin pyroelectric transducer, a very simple and versatile ac calorimeter can be built. The described inverse pyroelectric technique allows high-resolution ac-calorimetric measurements of the temperature dependence of the specific heat capacity. Since measuring frequencies up to a few

J. Caerels; C. Glorieux; J. Thoen

1998-01-01

50

Absolute airborne gravimetry  

Microsoft Academic Search

This work consists of a feasibility study of a first stage prototype airborne absolute gravimeter system. In contrast to relative systems, which are using spring gravimeters, the measurements acquired by absolute systems are uncorrelated and the instrument is not suffering from problems like instrumental drift, frequency response of the spring and possible variation of the calibration factor. The major problem

Henri Baumann

2005-01-01

51

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

E-print Network

This work presents the direct torque control (DTC) techniques, implemented in four- and six-switch inverter, for brushless dc (BLDC) motors with non-sinusoidal back- EMF using two and three-phase conduction modes. First of all, the classical direct...

Ozturk, Salih Baris

2009-05-15

52

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

ERIC Educational Resources Information Center

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…

Atram, Dattatraya Balaram

2011-01-01

53

Absolute and relative blindsight.  

PubMed

The concept of relative blindsight, referring to a difference in conscious awareness between conditions otherwise matched for performance, was introduced by Lau and Passingham (2006) as a way of identifying the neural correlates of consciousness (NCC) in fMRI experiments. By analogy, absolute blindsight refers to a difference between performance and awareness regardless of whether it is possible to match performance across conditions. Here, we address the question of whether relative and absolute blindsight in normal observers can be accounted for by response bias. In our replication of Lau and Passingham's experiment, the relative blindsight effect was abolished when performance was assessed by means of a bias-free 2AFC task or when the criterion for awareness was varied. Furthermore, there was no evidence of either relative or absolute blindsight when both performance and awareness were assessed with bias-free measures derived from confidence ratings using signal detection theory. This suggests that both relative and absolute blindsight in normal observers amount to no more than variations in response bias in the assessment of performance and awareness. Consideration of the properties of psychometric functions reveals a number of ways in which relative and absolute blindsight could arise trivially and elucidates a basis for the distinction between Type 1 and Type 2 blindsight. PMID:25305691

Balsdon, Tarryn; Azzopardi, Paul

2015-03-01

54

Risk governance for mobile phones, power lines, and other EMF technologies.  

PubMed

Power-frequency electric and magnetic fields (EMFs) have been present in industrialized countries since the late 19th century and a considerable amount of knowledge has been accumulated as to potential health effects. The mainstream scientific view is that even if there is a risk, it is unlikely to be of major public-health significance. EMFs from cellular communications and other radio-frequency technologies have increased rapidly in the last decade. This technology is constantly changing, which makes continued research both more urgent and more challenging. While there are no persuasive data suggesting a health risk, research and particularly exposure assessment is still immature. The principal risk-governance issue with power frequencies is how to respond to weak and uncertain scientific evidence that nonetheless causes public concern. For radio-frequency electromagnetic fields, the issue is how to respond to large potential consequences and large public concern where only limited scientific evidence exists. We survey these issues and identify deficits in risk governance. Deficits in problem framing include both overstatement and understatement of the scientific evidence and of the consequences of taking protective measures, limited ability to detect early warnings of risk, and attempted reassurance that has sometimes been counterproductive. Other deficits relate to the limited public involvement mechanisms, and flaws in the identification and evaluation of tradeoffs in the selection of appropriate management strategies. We conclude that risk management of EMFs has certainly not been perfect, but for power frequencies it has evolved and now displays many successful features. Lessons from the power-frequency experience can benefit risk governance of the radio-frequency EMFs and other emerging technologies. PMID:20723143

Kheifets, Leeka; Swanson, John; Kandel, Shaiela; Malloy, Timothy F

2010-10-01

55

New Thermodynamic Data for Liquid Aluminum-Magnesium Alloys from emf, Vapor Pressures, and Calorimetric Studies  

Microsoft Academic Search

Experimental thermodynamic studies of liquid Al-Mg alloys have been performed by several methods resulting in: (1) Mg activities\\u000a from galvanic cells with liquid electrolytes at temperatures from\\u000a 910 to 1070 K, at XMg = 0.1 to 0.7 and for the dilute range when XMg = 0.0126 to 0.1430 at 927 K; (2) Mg activities from the emf method with solid

Z. Moser; W. Zakulski; K. Rzyman; W. Gasior; Z. Panek; I. Katayama; T. Matsuda; Y. Fukuda; T. Iida; Z. Zajaczkowski; J. Botor

1998-01-01

56

Absolute pitch may not be so absolute.  

PubMed

Most people cannot name the musical note that corresponds to a particular pitch without being provided a reference note, but those people with absolute pitch (AP) can do this accurately. Early experience during a developmental period is often thought to convey identity and stability of the note categories in people with AP, but the plasticity of these categories has not been investigated. Here we provide the first evidence that the note categories of adults with AP can change with listening experience. Participants with AP showed shifts in perception in direct accord with prior exposure to music detuned by a fraction of a semitone. This suggests that the apparent stability of AP categories is conferred not by early experience but rather by the cultural norms adopted for tuning music. PMID:23757308

Hedger, Stephen C; Heald, Shannon L M; Nusbaum, Howard C

2013-08-01

57

Tellurium activities in the Pd-Te system by emf measurements  

NASA Astrophysics Data System (ADS)

The emf of the galvanic cells Pt, C, [Te] Pd-Te, TeO 2¦15 YSZ¦O 2(P O 2 = 0.21 atm), Pt (I) using 15 mass% yttria-stabilized zirconia (15 YSZ) as the solid electrolyte were measured for 15 different alloy compositions ranging from 5 to 64.3 at% Te over the temperature range 550 to 1000 K. Breaks in the plots of emf could be observed in the temperature interval of 740 to 780 K in the composition range 28 to 43 at% Te corresponding to peritectoid, eutectoid, eutectic and peritectic reactions. Combining these data with the emf expression for the cell Pt, C, Te(s or 1), TeO 2(s)¦15 YSZ¦O 2(P O 2 = 0.21 atm), Pt (II) reported in the literature, values of log aTe were computed. Typical expression for the logaTe in the miscibility gap region between PdTe and PdTe 2 was calculated to be ( logaTe( PdTe/ PdTe2) ± 0.14) = 2.3496 - 3001./ T (613-995 K) with reference to liquid tellurium as the standard state. At 700 K, there seems to be a systematic increase in ? overlineGTe values for the compositions from 32 to 38 at% Te instead of a constant value expected from the phase diagrams.

Mallika, C.; Sreedharan, O. M.

1989-09-01

58

Sensorless inverter-fed compressor drive system using saliency back-EMF based intelligent torque observer with MTPA control  

Microsoft Academic Search

A saliency back-EMF based wavelet fuzzy neural network (WFNN) torque observer using a new maximum torque per ampere (MTPA) control is proposed in this study to improve the speed estimating performance of a sensorless interior permanent magnet synchronous motor (IPMSM) drive system. First, the characteristics and mathematical model of the saliency back-EMF based proportional-integral-derivative (PID) torque observer with the mechanical

Faa-Jeng Lin

2014-01-01

59

Relative and Absolute Directions  

NSDL National Science Digital Library

The purpose of this resource is to learn about latitude and longitude while developing math skills. Students begin by asking the simple question: 'Where Am I?' Then they learn about the magnetic Earth and the use of compasses and angles. Students also learn about the difference between relative and absolute locations. Throughout this activity, students practice using a variety of math skills.

The GLOBE Program, University Corporation for Atmospheric Research (UCAR)

2003-08-01

60

Absolute configuration of neostenine  

NASA Astrophysics Data System (ADS)

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.

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

2010-03-01

61

Low frequency EMF regulates chondrocyte differentiation and expression of matrix proteins.  

PubMed

This study describes the enhancement of chondrogenic differentiation in endochondral ossification by extremely low frequency pulsed electric/magnetic fields (EMFs). The demineralized bone matrix (DBM)-induced endochondral ossification model was used to examine the effects of EMF stimulation. [35S]-Sulfate and [3H]-thymidine incorporation and glycosaminoglycan (GAG) content were determined by standard methods. Proteoglycan (PG) and GAG molecular size and composition were determined by gel chromatography and sequential enzyme digestion. Immunohistochemical and Western blot analysis of PGs were done with antibodies 2B6, 3B3, 2D3 and 5D4. Northern analysis of total RNA extracts was performed for aggrecan, and type II collagen. All data was compared for significance by Student's t- or analysis of variance (ANOVA)-tests. The EMF field accelerated chondrogenesis as evidenced by an increase in: (1) 35SO4 incorporation and GAG content, (2) the number of chondrocytes at day 8 of development, (3) the volumetric density of cartilage and (4) the extent of immunostaining for 3B3 and 5D4. No differences in DNA content or [3H]-thymidine incorporation were observed between control and stimulated ossicles, suggesting the absence of enhanced cell proliferation or recruitment as a mechanism for the acceleration. PG and GAG molecular sizes and GAG chemical composition were similar in stimulated and control ossicles, indicating that stimulation resulted in an accelerated synthesis of normal cartilage molecules. The increased expression of PG and type II collagen mRNA as well as a greater immunoreactivity of 3B3 and 5D4 suggest an increase in the rate of differentiation of chondrocytes and enhanced phenotypic maturation. PMID:11853089

Ciombor, Deborah McK; Lester, Gayle; Aaron, Roy K; Neame, Peter; Caterson, Bruce

2002-01-01

62

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

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).

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

1993-08-01

63

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

PubMed

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

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

2011-01-01

64

Absolute airborne gravimetry  

NASA Astrophysics Data System (ADS)

This work consists of a feasibility study of a first stage prototype airborne absolute gravimeter system. In contrast to relative systems, which are using spring gravimeters, the measurements acquired by absolute systems are uncorrelated and the instrument is not suffering from problems like instrumental drift, frequency response of the spring and possible variation of the calibration factor. The major problem we had to resolve were to reduce the influence of the non-gravitational accelerations included in the measurements. We studied two different approaches to resolve it: direct mechanical filtering, and post-processing digital compensation. The first part of the work describes in detail the different mechanical passive filters of vibrations, which were studied and tested in the laboratory and later in a small truck in movement. For these tests as well as for the airborne measurements an absolute gravimeter FG5-L from Micro-G Ltd was used together with an Inertial navigation system Litton-200, a vertical accelerometer EpiSensor, and GPS receivers for positioning. These tests showed that only the use of an optical table gives acceptable results. However, it is unable to compensate for the effects of the accelerations of the drag free chamber. The second part describes the strategy of the data processing. It is based on modeling the perturbing accelerations by means of GPS, EpiSensor and INS data. In the third part the airborne experiment is described in detail, from the mounting in the aircraft and data processing to the different problems encountered during the evaluation of the quality and accuracy of the results. In the part of data processing the different steps conducted from the raw apparent gravity data and the trajectories to the estimation of the true gravity are explained. A comparison between the estimated airborne data and those obtained by ground upward continuation at flight altitude allows to state that airborne absolute gravimetry is feasible and has a spatial resolution comparable to the one of the relative airborne gravimetry. For a wavelength on the order of 11 km the mean value of the resolution of the estimated gravity is 9.7 mGal. Finally some suggestions are formulated for the improvement of the system which should simplify its use, increase the accuracy and reduce its price.

Baumann, Henri

65

Electronic Absolute Cartesian Autocollimator  

NASA Technical Reports Server (NTRS)

An electronic absolute Cartesian autocollimator performs the same basic optical function as does a conventional all-optical or a conventional electronic autocollimator but differs in the nature of its optical target and the manner in which the position of the image of the target is measured. The term absolute in the name of this apparatus reflects the nature of the position measurement, which, unlike in a conventional electronic autocollimator, is based absolutely on the position of the image rather than on an assumed proportionality between the position and the levels of processed analog electronic signals. The term Cartesian in the name of this apparatus reflects the nature of its optical target. Figure 1 depicts the electronic functional blocks of an electronic absolute Cartesian autocollimator along with its basic optical layout, which is the same as that of a conventional autocollimator. Referring first to the optical layout and functions only, this or any autocollimator is used to measure the compound angular deviation of a flat datum mirror with respect to the optical axis of the autocollimator itself. The optical components include an illuminated target, a beam splitter, an objective or collimating lens, and a viewer or detector (described in more detail below) at a viewing plane. The target and the viewing planes are focal planes of the lens. Target light reflected by the datum mirror is imaged on the viewing plane at unit magnification by the collimating lens. If the normal to the datum mirror is parallel to the optical axis of the autocollimator, then the target image is centered on the viewing plane. Any angular deviation of the normal from the optical axis manifests itself as a lateral displacement of the target image from the center. The magnitude of the displacement is proportional to the focal length and to the magnitude (assumed to be small) of the angular deviation. The direction of the displacement is perpendicular to the axis about which the mirror is slightly tilted. Hence, one can determine the amount and direction of tilt from the coordinates of the target image on the viewing plane.

Leviton, Douglas B.

2006-01-01

66

Characterization of the DARA solar absolute radiometer  

NASA Astrophysics Data System (ADS)

The Davos Absolute Radiometer (DARA) prototype is an Electrical Substitution Radiometer (ESR) which has been developed as a successor of the PMO6 type on future space missions and ground based TSI measurements. The DARA implements an improved thermal design of the cavity detector and heat sink assembly to minimize air-vacuum differences and to maximize thermal symmetry of measuring and compensating cavity. The DARA also employs an inverted viewing geometry to reduce internal stray light. We will report on the characterization and calibration experiments which were carried out at PMOD/WRC and LASP (TRF).

Finsterle, W.; Suter, M.; Fehlmann, A.; Kopp, G.

2011-12-01

67

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

PubMed

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

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

2014-12-01

68

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

PubMed

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

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

2014-07-01

69

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

NASA Astrophysics Data System (ADS)

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).

Mallika, C.; Sreedharan, O. M.

1990-03-01

70

The information as Absolute  

E-print Network

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.

Sergey V. Shevchenko; Vladimir V. Tokarevsky

2010-04-20

71

NOVA: Absolute Zero  

NSDL National Science Digital Library

On a hot day, some might wish they could get the temperature down a bit. They might not wish it to be as cold as, say absolute zero, but there are many scientists who are interested in doing just that. For those who are curious, absolute zero clocks in at around minus 460 degrees Fahrenheit. This engaging website is meant to serve as a complementary resource to the two-part series that recently aired on NOVA on this engaging topic. Visitors can start by watching a short preview of the program, and then continuing on to look over some of the special interactive features on the site. All told, there are ten different features, including "A Sense of Scale", "How Low Can You Go?", and "Milestones in Cold Research". The "Milestones in Cold Research" is a great place to start, as it's an interactive timeline that chronicles the "netherworld of extraordinarily low temperatures" as investigated by everyone from Galileo to current researchers. Of course, there are also more playful features here, such as "The Ice Trade", which asks users to dispatch ships loaded with natural ice to Florida, Brazil, and India.

72

Baroelectric Emf of an ion-conducting solid-state cell: Elementary processes in a loaded open system  

NASA Astrophysics Data System (ADS)

The baroelectric emf of an Ag+-conducting solid-state cell Ag-Ag4RbI5-Ag is investigated. It is shown that, when one of the electrodes of the ion-conducting solid-state cell is loaded, the baroelectric emf of the cell is equal to the sum of the electronic and ionic baroelectric contact potential differences. The electronic (ionic) baroelectric contact potential difference is determined by the work done by the load on changing the electrode volume upon the removal of one electron (ion). The elementary processes responsible for the change in the volume due to the removal of a particle are discussed.

Gerbshte?in, Yu. M.; Timoshchenko, N. E.

2007-04-01

73

Environmental Pathology: SY09-2 MULTIPLE SCLEROSIS (MS) AND NEURODEGENERATION: CAUSE AND PATHOGENESIS IN RELATION TO ELECTROMAGNETIC FIELDS (EMF).  

PubMed

Multiple sclerosis (MS) is prevalent in higher latitude areas where geomagnetic storms often occur. The earliest pathological finding is myelin destruction. Myelin is a high capacitance electrolytic capacitor that can store a large amount of charge and energy. Since storms possess high-energy electromagnetic fields (EMF), the capacitor will be overcharged, which may break down the dielectric. As a result, a short circuit occurs and electrolytes heat up and/or the capacitor may burst. Also, EMFs have the potential to induce hotspots in the center of the brain. The increased temperature of the cerebrospinal fluid will cause hot water burns in surrounding areas. Thus, two distinct lesions exist in MS, electric shock and hot water burns. In addition, the overcharged capacitor will produce repetitive or continuous action potentials, causing excess Ca2+ influxes and subsequent excitotoxicity. This leads to mitochondrial dysfunction, including an energy deficit, oxidative stress and apoptosis. Moreover, EMFs activate microglia via activation of voltage-gated ion channels. These MS related neurodegenerative and inflammatory processes could have causes and pathogeneses in common with Alzheimer's, Parkinson's, and amyotrophic lateral sclerosis, which are often reported in MS patients. I hypothesize thus that MS and certain common neurodegenerative diseases are caused by high energy EMF. PMID:25188068

Kudo, Motoshige

2014-10-01

74

Thermodynamic studies on chromium carbides by the electromotive force (emf) method  

Microsoft Academic Search

The Gibbs energies of formation ?fG° of the three carbides Cr3C2, Cr7C3 and Cr23C6 existing in the Cr–C system were re-determined by electromotive force (emf) measurements between 930 and 1120 K using the galvanic cells Cr, CrF2?CaF2?CrF2, CrmCn, CrpCq which give at 1100 K: ?fG° ?Cr3C2?=?84.3 kJ\\/mol, ?fG° ?Cr7C3?=?177 kJ\\/mol and ?fG° ?Cr23C6?=?407 kJ\\/mol. The third-law enthalpies of formation ?fH°

Heiko Kleykamp

2001-01-01

75

Absolute configuration of isoeichlerialactone  

PubMed Central

The title seco-dammarane triterpenoid, C27H42O4 (systematic name: 3-{(3S,3aR,5aR,6S,7S,9aR,9bR)-6,9a,9b-trimethyl-3-[(R)-2-methyl-5-oxotetra­hydro­furan-2-yl]-7-(prop-1-en-2-yl)dodeca­hydro-1H-cyclo­penta­[a]naphthalen-6-yl}propanoic acid), has been isolated for the first time from the seeds of Aglaia forbesii. The mol­ecule has three fused rings and all rings are in trans-fused. The two cyclo­hexane rings are in standard chair conformations and the cyclo­pentane ring adopts an envelope conformation. Its absolute configuration was determined by the refinement of the Flack parameter to 0.26?(17). In the crystal, mol­ecules are linked into chains along [010] by O—H?O hydrogen bonds. PMID:21580698

Fun, Hoong-Kun; Joycharat, Nantiya; Voravuthikunchai, Supayang Piyawan; Chantrapromma, Suchada

2010-01-01

76

The Absolute Relativity Theory  

E-print Network

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.

Jean-Marc Oury; Bruno Heintz

2009-08-18

77

Technical Evaluation Report "COS Thermal Sensitivity"  

E-print Network

.............................................................................................. 2 4.1 FUV Detector Thermal Requirements and managed during the remaining life of the HST. Two thermal issues are discussed in this memo, absolute, thermally induced mechanical distortion and thermally induced detector distortions. Both of these effects

Colorado at Boulder, University of

78

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

SciTech Connect

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.

Hsu, J.S.

2004-09-30

79

Analysis of standard reference materials by absolute INAA  

SciTech Connect

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.

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

1981-07-01

80

Effects of whole body exposure to extremely low frequency electromagnetic fields (ELF-EMF) on serum and liver lipid levels, in the rat  

PubMed Central

Backgound The effects of extremely low-frequency electromagnetic fields (ELF-EMF) on the blood serum and liver lipid concentrations of male Wistar rats were assessed. Methods Animals were exposed to a single stimulation (2 h) of ELF-EMF (60 Hz, 2.4 mT) or sham-stimulated and thereafter sacrificed at different times (24, 48 or 96 h after beginning the exposure). Results Blood lipids showed, at 48 h stimulated animals, a significant increase of cholesterol associated to high density lipoproteins (HDL-C) than those observed at any other studied time. Free fatty acid serum presented at 24 h significant increases in comparison with control group. The other serum lipids, triacylglycerols and total cholesterol did not show differences between groups, at any time evaluated. No statistical differences were shown on total lipids of the liver but total cholesterol was elevated at 24 h with a significant decrease at 96 h (p = 0.026). The ELF-EMF stimulation increased the liver content of lipoperoxides at 24 h. Conclusion Single exposures to ELF-EMF increases the serum values of HDL-C, the liver content of lipoperoxides and decreases total cholesterol of the liver. The mechanisms for the effects of ELF-EMF on lipid metabolism are not well understand yet, but could be associated to the nitric oxide synthase EMF-stimulation. PMID:18021407

Torres-Duran, Patricia V; Ferreira-Hermosillo, Aldo; Juarez-Oropeza, Marco A; Elias-Viñas, David; Verdugo-Diaz, Leticia

2007-01-01

81

Absolute instability in a TWT  

NASA Astrophysics Data System (ADS)

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.

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

1998-11-01

82

Database applicaton for absolute spectrophotometry  

NASA Astrophysics Data System (ADS)

32-bit database application with multidocument interface for Windows has been developed to calculate absolute energy distributions of observed spectra. The original database contains wavelength calibrated observed spectra which had been already passed through apparatus reductions such as flatfielding, background and apparatus noise subtracting. Absolute energy distributions of observed spectra are defined in unique scale by means of registering them simultaneously with artificial intensity standard. Observations of sequence of spectrophotometric standards are used to define absolute energy of the artificial standard. Observations of spectrophotometric standards are used to define optical extinction in selected moments. FFT algorithm implemented in the application allows performing convolution (deconvolution) spectra with user-defined PSF. The object-oriented interface has been created using facilities of C++ libraries. Client/server model with Windows Socket functionality based on TCP/IP protocol is used to develop the application. It supports Dynamic Data Exchange conversation in server mode and uses Microsoft Exchange communication facilities.

Bochkov, Valery V.; Shumko, Sergiy

2002-12-01

83

The role of the JAK2-STAT3 pathway in pro-inflammatory responses of EMF-stimulated N9 microglial cells  

PubMed Central

Background In several neuropathological conditions, microglia can become overactivated and cause neurotoxicity by initiating neuronal damage in response to pro-inflammatory stimuli. Our previous studies have shown that exposure to electromagnetic fields (EMF) activates cultured microglia to produce tumor necrosis factor (TNF)-? and nitric oxide (NO) through signal transduction involving the activator of transcription STAT3. Here, we investigated the role of STAT3 signaling in EMF-induced microglial activation and pro-in?ammatory responses in more detail than the previous study. Methods N9 microglial cells were treated with EMF exposure or a sham treatment, with or without pretreatment with an inhibitor (Pyridone 6, P6) of the Janus family of tyrosine kinases (JAK). The activation state of microglia was assessed via immunoreaction using the microglial marker CD11b. Levels of inducible nitric oxide synthase (iNOS), TNF-? and NO were measured using real-time reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA) and the nitrate reductase method. Activation of JAKs and STAT3 proteins was evaluated by western blotting for specific tyrosine phosphorylation. The ability of STAT3 to bind to DNA was detected with an electrophoresis mobility shift assay (EMSA). Results EMF was found to significantly induce phosphorylation of JAK2 and STAT3, and DNA-binding ability of STAT3 in N9 microglia. In addition, EMF dramatically increased the expression of CD11b, TNF-? and iNOS, and the production of NO. P6 strongly suppressed the phosphorylation of JAK2 and STAT3 and diminished STAT3 activity in EMF-stimulated microglia. Interestingly, expression of CD11b as well as gene expression and production of TNF-? and iNOS were suppressed by P6 at 12 h, but not at 3 h, after EMF exposure. Conclusions EMF exposure directly triggers initial activation of microglia and produces a significant pro-inflammatory response. Our findings confirm that the JAK2-STAT3 pathway may not mediate this initial microglial activation but does promote pro-inflammatory responses in EMF-stimulated microglial cells. Thus, the JAK2-STAT3 pathway might be a therapeutic target for reducing pro-inflammatory responses in EMF-activated microglia. PMID:20828402

2010-01-01

84

Absolute reflectances from reflectometer readings.  

PubMed

Equations have been derived that allow differences in reflectometer readings of the same sample with various reflectometers to be minimized by placing all reflectances on an absolute basis. For pigmented vehicle films the Fresnel reflectances and transmittances at the air-vehicle interface can be calculated for an arbitrary incident angular light distribution. The form of the reflected and transmitted angular distributions can also be calculated. The equations have been used to determine absolute reflectances of titanium dioxide pigmented films from meter readings of two reflectometers-the General Electric Recording and the Colormaster. PMID:20111160

Sullivan, W F

1971-07-01

85

Achieving Climate Change Absolute Accuracy in Orbit  

NASA Technical Reports Server (NTRS)

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.

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

86

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

NASA Technical Reports Server (NTRS)

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.

Cairns, E. J.; Shimotake, H.

1969-01-01

87

Classical Mechanics without Absolute Space  

E-print Network

A relative mechanics with no absolute space is shown to be equivalent to Newtonian mechanics applied in a universe of zero net angular momentum. Closed spaces in General Relativity have no angular momentum and shrivel to one point as the mass-energy contained tends to zero, so obeying Mach's principle on the origin of inertia.

D. Lynden-Bell; J. Katz

1995-10-01

88

Absolute configuration of amphidinin A.  

PubMed

The absolute configurations at six stereogenic centers in amphidinin A (1), a cytotoxic linear polyketide isolated from a symbiotic marine dinoflagellate, Amphidinium sp., were elucidated to be 2R, 4R, 6S, 9R 11R, and 12S by the combination of J-based configuration analysis, modified Mosher's method, and density-functional theory calculations. PMID:24836179

Iwai, Takahiro; Kubota, Takaaki; Kobayashi, Jun'ichi

2014-06-27

89

Absolute transition probabilities of phosphorus.  

NASA Technical Reports Server (NTRS)

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.-

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

1971-01-01

90

Absolute Pitch and Planum Temporale  

Microsoft Academic Search

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

Julian Paul Keenan; Ven Thangaraj; Andrea R. Halpern; Gottfried Schlaug

2001-01-01

91

Thermodynamic behavior of high-T sub c oxide systems via EMF and related measurements  

SciTech Connect

EMF measurements of oxygen fugacities as a function of stoichiometry have been made in the YBa{sub 2}Cu{sub 3}O{sub x}, and NdBa{sub 2}Cu{sub 3}O{sub x}, and Nd{sub 1.81}Ce{sub 0.19}CuO{sub x} superconducting systems in the temperature range 400--750{degree}C by means of an oxygen titration technique with an yttria-stabilized zirconia electrolyte. The object of our current measurements is to investigate the effect of ionic size of Y, Gd and Nd on the thermodynamic behavior and structural transition in the LnBa{sub 2}Cu{sub 3}O{sub x} system. The shape of the 400{degree}C isotherm for NdBa{sub 2}Cu{sub 3}O{sub x} suggests the presence of a miscibility gap at lower temperatures, at values of x that are higher than those in the YBa{sub 2}Cu{sub 3}O{sub x} system. The locations of the miscibility gaps are consistent with the effects of ionic radii on the composition dependence of {Tc} for these systems. Our results explain the two plateaus in measured value of {Tc} as a function of composition for the YBa{sub 2}Cu{sub 3}O{sub x} system and appear to be consistent with the less pronounced {Tc} plateaus found for the NdBa{sub 2}Cu{sub 3}O{sub x} system higher stoichiometry values. For a given oxygen stoichiometry, partial pressures of oxygen above NdBa{sub 2}Cu{sub 3}O{sub x} are higher than for the YBa{sub 2}Cu{sub 3}O{sub x} system in accord with calculated partial molar thermodynamic quantities. The results of limited measurements on the n-type (electron-doped) superconducting Nd{sub 1.81}Ce{sub 0.19}CuO{sub x} system will be presented. A thermodynamic assessment and intercomparison of our oxygen partial pressure measurements with the results of other measurements will be presented. 34 refs., 9 figs., 1 tab.

Tetenbaum, M.; Tumidajaski, P.; Bloom, I.D.; Brown, D.L.; Blander, M.

1991-01-01

92

Potentiality of a New Minimum-Order Back-EMF State-Observer Taking Acceleration into Account for Sensorless Vector Control of Permanent-Magnet Synchronous Motors  

NASA Astrophysics Data System (ADS)

This paper proposes new sensorless vector control methods for permanent-magnet synchronous motors (PMSMs), which are based on a new minimum-order back-EMF state-observer taking acceleration into account, and examines potentiality of the improved back-EMF observer through experiments. Conventional sensorless vector control methods for PMSMs using an estimate of back-EMF are established under the assumption of constant speed or zero acceleration, consequently cannot operate properly at modes requiring rapid speed change especially in low speed region. On the other hand, the proposed back-EMF observer has the following features: 1) it is a new back-EMF state-observer taking acceleration into account and requiring no additional approximation to motor mathematical model; 2) it is a minimum order state-observer; 3) it utilizes motor parameters in the simplest manner; 4) it can be applied to both of salient-pole and non-salient-pole PMSMs; 5) it can be realized in both rotor and stator reference frames. Detailed designs and analyses for the improved state-observer and the sensorless vector control systems in both rotor and stator reference frames are given. In relation to the sensorless vector control systems, this paper newly proposes a double-integral type PLL method and an integral-feedback type acceleration/speed estimation method. Their potentialities are examined through experiments.

Shinnaka, Shinji; Saito, Yoji

93

[Biological mechanisms and health effects of emf in view of requirements of reports on the impact of various installations on the environment].  

PubMed

This paper presents a review of the literature dealing with the health effects of exposure to electromagnetic fields (EMFs) emitted by installations, in case of which reports on their impact on the environment are required. A thesis has been formulated that at present, it is not feasible to meet the requirements of the legislator and present in these reports explicit evidence that EMFs exert harmful effect on humans. The major doubts faced by experts are raised by magnetic fields of the power-line frequency (50 Hz) present in the neighborhood of electric power lines and distribution-transformer stations. Although data indicating that they may increase cancer risk in humans do exist, it is not possible to clearly state that their effect is carcinogenic, but only possibly carcinogenic to humans (according to the IARC categorization) in view of the fact that the mechanisms by which EMFs exert their effect have not yet been elucidated. It has not been evidenced that EMFs emitted by radio and TV broadcasting stations, mobile communications or TETRA system induce any adverse health effects in persons living in their vicinity. However, some reports indicating that they may induce health effects (carcinogenicity and disturbances in the function of the central nervous system) have been published. Therefore, further intensive investigations, especially epidemiological (cohort and case-control) studies are needed. They should involve an appropriate exposure assessment, i.e., estimation of EMF magnitude based on measurements and not on distance from antennas. PMID:17571626

Zmy?lony, Marek

2007-01-01

94

Effect of Pressure on the Emf of W5%Re-W26%Re Thermocouple: Implications for the 660-km Seismic Discontinuity  

NASA Astrophysics Data System (ADS)

It has been long accepted that the phase transformations in olivine are responsible for the observed seismic velocity discontinuities at 410-km and 660-km depths. However, recent in-situ determinations of postspinel phase boundary in olivine have suggested that the phase transformation occurs at a pressure about 2 GPa lower than that at 660-km depth [e.g. Irifune et al. 98, Hirose et al.01]. One of the possible reasons for the discrepancy is the ignored effect of pressure on the electromotive force (emf) of W5%Re-W26%Re (type C) thermocouple. We measured the apparent temperature difference between type C and Pt10%Rh-Pt (type S) thermocouples and emfs of additional thermocouples formed at the four-wire junction between 1 bar and 15 GPa, and between room temperature and 1800 ° C, using a multi-anvil apparatus. Based on extrapolation of the directly measured pressure-induced emf on type S wires to 3.5 GPa and 1000 ° C [Getting and Kennedy, 1970], we estimated the pressure-induced emf on type C wires. Our results suggest that the effect of pressure on the emf of type C thermocouple is not sufficient to explain the observed discrepancy.

Li, J.; Hadidiacos, C.; Mao, H.; Fei, Y.

2002-05-01

95

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

96

The Absolute Spectrum Polarimeter (ASP)  

NASA Technical Reports Server (NTRS)

The Absolute Spectrum Polarimeter (ASP) is an Explorer-class mission to map the absolute intensity and linear polarization of the cosmic microwave background and diffuse astrophysical foregrounds over the full sky from 30 GHz to 5 THz. The principal science goal is the detection and characterization of linear polarization from an inflationary epoch in the early universe, with tensor-to-scalar ratio r much greater than 1O(raised to the power of { -3}) and Compton distortion y < 10 (raised to the power of{-6}). We describe the ASP instrument and mission architecture needed to detect the signature of an inflationary epoch in the early universe using only 4 semiconductor bolometers.

Kogut, A. J.

2010-01-01

97

Impedance of a Spacecraft-Borne Antenna in the Magnetospheric Plasma and Quasi-Equilibrium Noise EMF in the Lower-Hybrid Frequency Band  

NASA Astrophysics Data System (ADS)

We present analytical and numerical estimations of the value and frequency dependence of the impedance and noise electromotive force (EMF) in the context of the conditions which correspond to the trajectories and parameters of the antennas borne by geophysical monitoring satellites. The estimations were obtained for two circular orbits at altitudes of 600 and 1200 km over the Earth's surface in the frequency range from 20 to 120 kHz, which corresponded to the area of the lower-hybrid resonance, where a higher level of noise emissions is observed at the altitudes under consideration. It is shown that near the lower-hybrid resonance frequency, the real part of the antenna impedance is determined by the resonant "monopole" loss by radiation of quasipotential waves. In the nonresonant frequency band (at the frequencies below the frequency of the lowerhybrid resonance), the antenna reactance is determined by the transit loss, which is, however, low as compared with the resonant loss. When the noise was calculated, the medium was assumed to be a two-temperature plasma. The spectral density of the power of the noise EMF lies in the range and is determined mainly by suprathermal electrons. In the nonresonant frequency band, the efficient temperature of noise radiation is equal to the temperature of the "cold" plasma component, and the antenna reactance is determined by the transit loss, i.e., the level of the noise EMF is low as compared with the EMF in the resonant frequency band.

Chugunov, Yu. V.; Grach, V. S.; Pasmanik, D. L.

2013-07-01

98

Dynamic Control of Adsorption Sensitivity for Photo-EMF-Based Ammonia Gas Sensors Using a Wireless Network  

PubMed Central

This paper proposes an adsorption sensitivity control method that uses a wireless network and illumination light intensity in a photo-electromagnetic field (EMF)-based gas sensor for measurements in real time of a wide range of ammonia concentrations. The minimum measurement error for a range of ammonia concentration from 3 to 800 ppm occurs when the gas concentration magnitude corresponds with the optimal intensity of the illumination light. A simulation with LabView-engineered modules for automatic control of a new intelligent computer system was conducted to improve measurement precision over a wide range of gas concentrations. This gas sensor computer system with wireless network technology could be useful in the chemical industry for automatic detection and measurement of hazardous ammonia gas levels in real time. PMID:22346680

Vashpanov, Yuriy; Choo, Hyunseung; Kim, Dongsoo Stephen

2011-01-01

99

An electromagnetic thermotherapy system with a deep penetration depth for percutaneous thermal ablation.  

PubMed

Thermal ablation has been a promising method to remove the cancerous tissues. Electromagnetic-based thermotherapy has been extensively investigated for a variety of medical applications recently. In this study, a prototype electromagnetic thermotherapy system has been developed with a new coil design and a two-section needle. The coil can generate an alternating electromagnetic field (EMF) with a deep penetration depth to remotely heat the needle which is located up to 15 cm away, enabling percutaneous thermal ablation. Several important parameters, including the heating effects of the needle at different positions, the intensity of the EMF and the induced temperature distribution on the surrounding tissue, are first explored. An in vitro animal experiment has also been performed which shows EMF-induced ablation in a porcine liver by the needle. Furthermore, an in vivo experiment on an animal model (a New Zealand white rabbit) is also conducted in the study. Thus, the two-section needle combined with the coil-generated EMF has been demonstrated to be a promising thermotherapy system for percutaneous thermal ablation. PMID:23990331

Huang, Sheng-Chieh; Chang, Yi-Yuan; Kang, Jui-Wen; Tsai, Hung-Wen; Shan, Yan-Shen; Lin, Xi-Zhang; Lee, Gwo-Bin

2014-01-01

100

Apparatus for absolute pressure measurement  

NASA Technical Reports Server (NTRS)

An absolute pressure sensor (e.g., the diaphragm of a capacitance manometer) was subjected to a superimposed potential to effectively reduce the mechanical stiffness of the sensor. This substantially increases the sensitivity of the sensor and is particularly useful in vacuum gauges. An oscillating component of the superimposed potential induced vibrations of the sensor. The phase of these vibrations with respect to that of the oscillating component was monitored, and served to initiate an automatic adjustment of the static component of the superimposed potential, so as to bring the sensor into resonance at the frequency of the oscillating component. This establishes a selected sensitivity for the sensor, since a definite relationship exists between resonant frequency and sensitivity.

Hecht, R. (inventor)

1969-01-01

101

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

NASA Technical Reports Server (NTRS)

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.

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

1978-01-01

102

Near threshold absolute TDCS: first results  

NASA Astrophysics Data System (ADS)

A new method, and first results for an impact energy 2 eV above the threshold of ionisation of helium, are presented for the measurement of absolute triple differential cross sections (TDCS) in a crossed beam experiment. The method is based upon measurement of beam/target overlap densities using known absolute total ionisation cross sections and of detection efficiencies using known absolute double differential cross sections (DDCS). For the present work the necessary absolute DDCS for 1 eV electrons had also to be measured. Results are presented for several different coplanar kinematics and are compared with recent DWBA calculations.

Rösel, T.; Schlemmer, P.; Röder, J.; Frost, L.; Jung, K.; Ehrhardt, H.

1992-12-01

103

Nonequilibrium equalities in absolutely irreversible processes  

NASA Astrophysics Data System (ADS)

We generalize nonequilibrium integral equalities to situations involving absolutely irreversible processes for which the forward-path probability vanishes and the entropy production diverges, rendering conventional integral fluctuation theorems inapplicable. We identify the mathematical origins of absolute irreversibility as the singularity of probability measure. We demonstrate the validity of the obtained equalities for several models.

Murashita, Yûto; Funo, Ken; Ueda, Masahito

2014-10-01

104

Absolute optical metrology : nanometers to kilometers  

NASA Technical Reports Server (NTRS)

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.

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

2005-01-01

105

Investigating Absolute Value: A Real World Application  

ERIC Educational Resources Information Center

Making connections between various representations is important in mathematics. In this article, the authors discuss the numeric, algebraic, and graphical representations of sums of absolute values of linear functions. The initial explanations are accessible to all students who have experience graphing and who understand that absolute value simply…

Kidd, Margaret; Pagni, David

2009-01-01

106

Absolute efficiency measurements with the 10B based Jalousie detector  

NASA Astrophysics Data System (ADS)

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).

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

2014-04-01

107

[The electromagnetic fields of the base stations of mobile radio communication and ecology. The estimation of danger of the base station EMF for population and for bioecosystems].  

PubMed

The estimation of the danger for the population and for the bioecosistems of the electromagnetic conditions around of the base stations was given. The insufficiency of the scientific knowledge does not allow to guarantee the safety of the population and of the bioecosystems in the conditions of a round-the-clock long-term influence of EMF RF. WHO recommends to use "Precautionary principle". PMID:16454342

Grigor'ev, Iu G; Grigor'ev, K A

2005-01-01

108

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

SciTech Connect

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.

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

109

Upregulation of basal TGFbeta1 levels by EMF coincident with chondrogenesis--implications for skeletal repair and tissue engineering.  

PubMed

Members of the TGFbeta/BMP gene family regulate cartilage and bone development. These genes are re-expressed in bone repair and are thought to mediate chondro- and osteoprogenitor cell differentiation. These observations have led to a therapeutic strategy of introducing these growth factors into experimental cartilage and bone defects. Therapeutic efficacy, however, has been limited by diffusion or inactivation of these growth factors from the desired site and by the inability to deliver sustained concentrations of growth factors. This study demonstrates an increase in basal TGFbeta mRNA and protein levels in association with chondrogenic differentiation in endochondral ossification. mRNA is increased by 158%; protein by 23%, and cells immunopositive for TGFbeta by 343% at maximal TGFbeta expression. Importantly, the pattern of TGFbeta expression is preserved throughout the developmental sequence. Our data suggest that the exposure to a specific electromagnetic field (EMF) enhances, but does not disorganize, chondrogenesis and endochondral calcification as well as the normal physiologic expression of TGFbeta. The ability to increase TGFbeta at a moderately low dose for sustained periods of time without disorganizing its physiology suggests the ability to establish temporal concentration gradients of growth factors for the purpose of stimulating skeletal repair. PMID:11918302

Aaron, Roy K; Wang, Shuo; Ciombor, Deborah M

2002-03-01

110

Absolute pitch twin study and segregation analysis.  

PubMed

Absolute pitch is a rare pitch-naming ability with unknown etiology. Some scientists maintain that its manifestation depends solely on environmental factors, while others suggest that genetic factors contribute to it. We sought to further investigate the hypothesis that genetic factors support the acquisition of absolute pitch and to better elucidate the inheritance pattern of this trait. To this end, we conducted a twin study and a segregation analysis using data collected from a large population of absolute pitch possessors. The casewise concordance rate of 14 monozygotic twin pairs, 78.6%, was significantly different from that of 31 dizygotic twin pairs, 45.2%, assuming single ascertainment (x(2) = 5.57, 1 df, p = .018), supporting a role for genetics in the development of absolute pitch. Segregation analysis of 1463 families, assuming single ascertainment, produced a segregation ratio p(D) = .089 with SEp(D) = 0.006. Unlike an earlier segregation analysis on a small number of absolute pitch probands from musically educated families, our study indicates that absolute pitch is not inherited in a simple Mendelian fashion. Based on these data, absolute pitch is likely genetically heterogeneous, with environmental, epigenetic, and stochastic factors also perhaps contributing to its genesis. These findings are in agreement with the results of our recent linkage analysis. PMID:21425900

Theusch, Elizabeth; Gitschier, Jane

2011-04-01

111

Absolute colorimetric characterization of a DSLR camera  

NASA Astrophysics Data System (ADS)

A simple but effective technique for absolute colorimetric camera characterization is proposed. It offers a large dynamic range requiring just a single, off-the-shelf target and a commonly available controllable light source for the characterization. The characterization task is broken down in two modules, respectively devoted to absolute luminance estimation and to colorimetric characterization matrix estimation. The characterized camera can be effectively used as a tele-colorimeter, giving an absolute estimation of the XYZ data in cd=m2. The user is only required to vary the f - number of the camera lens or the exposure time t, to better exploit the sensor dynamic range. The estimated absolute tristimulus values closely match the values measured by a professional spectro-radiometer.

Guarnera, Giuseppe Claudio; Bianco, Simone; Schettini, Raimondo

2014-03-01

112

Absolute, high-resolution optical position encoder  

NASA Astrophysics Data System (ADS)

Modern computer-controlled manufacturing machinery requires the absolute and highly accurate measurement of the linear position. Such an absolute, optical linear position encoder is described here. It is based on the transilluminance of a glass scale with an inexpensive light-emitting diode. The scale has two code tracks, one based on a pseudo-random binary sequence for the coarse determination of position and another periodic code for accurate fine-position measurement. A single-lens telecentric optical system images the code tracks in a mechanically insensitive way onto a custom photodetector. This special detector IC is capable of determining the components of the (complex) Fourier transform for the spatial frequency of the periodic code. The absolute optical position encoder shows a resolution of 10 nm andan absolute accuracy of better than 100 nm over short distances, verified with a commercial laser interferometer.

Engelhardt, Kai; Seitz, Peter

1996-01-01

113

Absolute, high-resolution optical position encoder.  

PubMed

Modern computer-controlled manufacturing machinery requires the absolute and highly accurate measurement of the linear position. Such an absolute, optical linear position encoder is described here. It is based on the transilluminance of a glass scale with an inexpensive light-emitting diode. The scale has two code tracks, one based on a pseudo-random binary sequence for the coarse determination of position and another periodic code for accurate fine-position measurement. A single-lens telecentric optical system images the code tracks in a mechanically insensitive way onto a custom photodetector. This special detector IC is capable of determining the components of the (complex) Fourier transform for the spatial frequency of the periodic code. The absolute optical position encoder shows a resolution of 10 nm and an absolute accuracy of better than 100 nm over short distances, verified with a commercial laser interferometer. PMID:21069000

Engelhardt, K; Seitz, P

1996-01-01

114

Magnifying absolute instruments for optically homogeneous regions  

SciTech Connect

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.

Tyc, Tomas [Institute of Theoretical Physics and Astrophysics, Masaryk University, Kotlarska 2, CZ-61 137 Brno (Czech Republic)

2011-09-15

115

Absolute Continuous Bivariate Generalized Exponential Distribution  

E-print Network

Absolute Continuous Bivariate Generalized Exponential Distribution Debasis Kundu and Rameshwar D. Gupta Abstract Generalized exponential distribution has been used quite effectively to model posi- tively skewed lifetime data as an alternative to the well known Weibull or gamma distributions

Kundu, Debasis

116

Emission trading with absolute and intensity caps  

E-print Network

The Kyoto Protocol introduced emission trading to help reduce the cost of compliances for the Annex B countries that have absolute caps. However, we need to expand the emission trading to cover developing countries in order ...

Song, Jaemin

2005-01-01

117

The absolute magnitudes of Type IA supernovae  

Microsoft Academic Search

Absolute magnitudes in the B, V, and I bands are derived for nine well-observed Type Ia supernovae, using host galaxy distances estimated via the surface brightness fluctuations or Tully-Fisher methods. These data indicate that there is a significant intrinsic dispersion in the absolute magnitudes at maximum light of Type Ia supernovae, amounting to +\\/- 0.8 mag in B, +\\/- 0.6

M. M. Phillips

1993-01-01

118

Dissociative Recombination of HCNH+: Absolute Cross-Sections and Branching Ratios  

Microsoft Academic Search

The dissociative recombination (DR) of HCNH+ has been studied at the heavy ion storage ring CRYRING. The absolute cross-sections have been measured between 0.01 meV and 0.2 eV collision energy. The DR thermal rate coefficients, which can be directly applied to modeling environments in thermal equilibrium, have been found to be 2.8×10-7(300\\/T)0.65 at temperatures T<1000 K. The DR branching fractions

J. Semaniak; B. F. Minaev; A. M. Derkatch; F. Hellberg; A. Neau; S. Rosén; R. Thomas; M. Larsson; H. Danared; A. Paál; M. af Ugglas

2001-01-01

119

Jasminum flexile flower absolute from India--a detailed comparison with three other jasmine absolutes.  

PubMed

Jasminum flexile flower absolute from the south of India and the corresponding vacuum headspace (VHS) sample of the absolute were analyzed using GC and GC-MS. Three other commercially available Indian jasmine absolutes from the species: J. sambac, J. officinale subsp. grandiflorum, and J. auriculatum and the respective VHS samples were used for comparison purposes. One hundred and twenty-one compounds were characterized in J. flexile flower absolute, with methyl linolate, benzyl salicylate, benzyl benzoate, (2E,6E)-farnesol, and benzyl acetate as the main constituents. A detailed olfactory evaluation was also performed. PMID:19831037

Braun, Norbert A; Kohlenberg, Birgit; Sim, Sherina; Meier, Manfred; Hammerschmidt, Franz-Josef

2009-09-01

120

New absolute magnitude calibrations for detached binaries  

NASA Astrophysics Data System (ADS)

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% (??/??0.15). 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: -0.18<(B-V)0<0.91, -1.6absolute magnitude 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.

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

2008-10-01

121

New absolute magnitude calibrations for detached binaries  

E-print Network

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: $-0.18<(B-V)_{0}<0.91$, $-1.6absolute magnitude 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.

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

2008-06-07

122

Absolute Zero: Community Education Outreach Guide  

NSDL National Science Digital Library

This guide provides curricular resources for study of the history and science of the quest for ever colder temperature. Designed for teachers and informal educators of middle school students. this guide offers hands-on demonstrations, questions to encourage student participation, suggestions for class activities, and ways to encourage students to continue studying the science. Topics include low-temperature physics and the impact of technologies such as air conditioning, refrigeration and liquefied gases. This material is related to a two-part public broadcasting special, Absolute Zero, produced by Meridian Productions and Windfall Films. Absolute Zero is underwritten by the National Science Foundation and the Alfred P. Sloan Foundation and is based largely on Tom Shachtmanâs acclaimed book, Absolute Zero and the Conquest of Cold.

2008-09-18

123

Thermal conductivity of liquids  

Microsoft Academic Search

The Bridgman equation for thermal conductivity of liquids is examined and a relation between sonic velocity and latent heat of vaporization is given. A correlation based on the hole theory of liquids is presented. This correlation predicts thermal conductivity in the temperature range of -20° to +80°C for 16 liquids, and at 20°C for 50 liquids with an average absolute

D. S. Viswanath

1967-01-01

124

Precise Measurement of the Absolute Fluorescence Yield  

SciTech Connect

We present preliminary results of the absolute yield of fluorescence emission in atmospheric gases. Measurements were performed at the Fermilab Test Beam Facility with a variety of beam particles and gases. Absolute calibration of the fluorescence yield to 5% level was achieved by comparison with two known light sources - the Cherenkov light emitted by the beam particles, and a calibrated nitrogen laser. The uncertainty of the energy scale of current Ultra-High Energy Cosmic Rays experiments will be significantly improved by the AIRFLY measurement.

Ave, M.; Daumiller, K.; Keilhauer, B.; Klages, H.; Salamida, F.; Smida, R. [Karlsruhe Institute of Technology, IK, Postfach 6980, D - 76021 Karlsruhe (Germany); Bohacova, M.; Nozka, L.; Palatka, M.; Ridky, J.; Schovanek, P. [Institute of Physics of the Academy of Sciences of the Czech Republic, Na Slovance 2, CZ-182 21 Praha 8 (Czech Republic); Di Carlo, P.; Iarlori, M.; Petrera, S.; Rizi, V. [Dipartimento di Fisica dell'Universita de l'Aquila and INFN, Via Vetoio, I-67010 Coppito, Aquila (Italy); Di Giulio, C.; Verzi, V. [Dipartimento di Fisica dell'Universita di Roma Tor Vergata and Sezione INFN, Via della Ricerca Scientifica, I-00133 Roma (Italy); San Luis, P. Facal; Monasor, M.; Privitera, P. [University of Chicago, Enrico Fermi Institute and Kavli Institute for Cosmological Physics, 5640 S. Ellis Ave., Chicago, IL 60637 (United States)

2011-09-22

125

Landsat-7 ETM+ radiometric stability and absolute calibration  

USGS Publications Warehouse

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.

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

2002-01-01

126

New absolute magnitude calibrations for detached binaries  

E-print Network

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: $-0.18<(B-V)_{0}<0.91$, $-1.6

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

2008-01-01

127

Absolute rate theories of epigenetic stability  

Microsoft Academic Search

Spontaneous switching events in most characterized genetic switches are rare, resulting in extremely stable epigenetic properties. We show how simple arguments lead to theories of the rate of such events much like the absolute rate theory of chemical reactions corrected by a transmission factor. Both the probability of the rare cellular states that allow epigenetic escape and the transmission factor

Aleksandra M. Walczak; José N. Onuchic; Peter G. Wolynes

2005-01-01

128

High-accuracy absolute distance metrology Proefschrift  

E-print Network

High-accuracy absolute distance metrology Proefschrift ter verkrijging van de graad van doctor aan and controls the formation with high accuracy is an essential component to enable the science measurement with high accuracy. For Darwin, the required accuracy would be 70 micrometers over a distance of up to 250

129

Absolute partial photoionization cross sections of ozone.  

SciTech Connect

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.

Berkowitz, J.; Chemistry

2008-04-01

130

An Absolute Electrometer for the Physics Laboratory  

ERIC Educational Resources Information Center

A low-cost, easy-to-use absolute electrometer is presented: two thin metallic plates and an electronic balance, usually available in a laboratory, are used. We report on the very good performance of the device that allows precise measurements of the force acting between two charged plates. (Contains 5 footnotes, 2 tables, and 6 figures.)

Straulino, S.; Cartacci, A.

2009-01-01

131

Relaxation of local high temperatures due to shock compression as observed by the emf from a copper-Constantan junction  

Microsoft Academic Search

The anomalous response of a copper-Constantan thermocouple to shock compression, where the junction consists of silver paste and includes a porous layer, is interpreted as being due to local heating and subsequent thermal relaxation by heat conduction. The thermal relaxation pattern, tentatively calculated using the diffusion equation, is consistent with the experimentally observed response.

Ken-Ichi Kondo; Akira Sawaoka

1981-01-01

132

An absolute measure for a key currency  

NASA Astrophysics Data System (ADS)

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.

Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

133

From Hubble's NGSL to Absolute Fluxes  

NASA Technical Reports Server (NTRS)

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.

Heap, Sara R.; Lindler, Don

2012-01-01

134

Absolute and relative dosimetry for ELIMED  

NASA Astrophysics Data System (ADS)

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.

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

2013-07-01

135

Absolute calibration of TFTR helium proportional countersa)  

NASA Astrophysics Data System (ADS)

The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 and 50 ms depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments.

Strachan, J. D.; Barnes, Cris W.; Diesso, M.; Jassby, D.; Johnson, L.; Loughlin, M.; McCauley, S.; Munsat, T.; Roquemore, A. L.

1995-02-01

136

Probing absolute spin polarization at the nanoscale.  

PubMed

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

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

2014-12-10

137

Absolute and relative dosimetry for ELIMED  

SciTech Connect

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.

Cirrone, G. A. P.; Schillaci, F.; Scuderi, V. [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania, Italy and Institute of Physics Czech Academy of Science, ELI-Beamlines project, Na Slovance 2, Prague (Czech Republic)] [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania, Italy and Institute of Physics Czech Academy of Science, ELI-Beamlines project, Na Slovance 2, Prague (Czech Republic); Cuttone, G.; Candiano, G.; Musumarra, A.; Pisciotta, P.; Romano, F. [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania (Italy)] [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania (Italy); Carpinelli, M. [INFN Sezione di Cagliari, c/o Dipartimento di Fisica, Università di Cagliari, Cagliari (Italy)] [INFN Sezione di Cagliari, c/o Dipartimento di Fisica, Università di Cagliari, Cagliari (Italy); Leonora, E.; Randazzo, N. [INFN-Sezione di Catania, Via Santa Sofia 64, Catania (Italy)] [INFN-Sezione di Catania, Via Santa Sofia 64, Catania (Italy); Presti, D. Lo [INFN-Sezione di Catania, Via Santa Sofia 64, Catania, Italy and Università di Catania, Dipartimento di Fisica e Astronomia, Via S. Sofia 64, Catania (Italy)] [INFN-Sezione di Catania, Via Santa Sofia 64, Catania, Italy and Università di Catania, Dipartimento di Fisica e Astronomia, Via S. Sofia 64, Catania (Italy); Raffaele, L. [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania, Italy and INFN-Sezione di Catania, Via Santa Sofia 64, Catania (Italy)] [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania, Italy and INFN-Sezione di Catania, Via Santa Sofia 64, Catania (Italy); Tramontana, A. [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania, Italy and Università di Catania, Dipartimento di Fisica e Astronomia, Via S. Sofia 64, Catania (Italy)] [INFN, Laboratori Nazionali del Sud, Via Santa Sofia 62, Catania, Italy and Università di Catania, Dipartimento di Fisica e Astronomia, Via S. Sofia 64, Catania (Italy); Cirio, R.; Sacchi, R.; Monaco, V. [INFN, Sezione di Torino, Via P.Giuria, 1 10125 Torino, Italy and Università di Torino, Dipartimento di Fisica, Via P.Giuria, 1 10125 Torino (Italy)] [INFN, Sezione di Torino, Via P.Giuria, 1 10125 Torino, Italy and Università di Torino, Dipartimento di Fisica, Via P.Giuria, 1 10125 Torino (Italy); Marchetto, F.; Giordanengo, S. [INFN, Sezione di Torino, Via P.Giuria, 1 10125 Torino (Italy)] [INFN, Sezione di Torino, Via P.Giuria, 1 10125 Torino (Italy)

2013-07-26

138

The absolute bioavailability of caffeine in man  

Microsoft Academic Search

The absolute bioavailability of orally administered caffeine was investigated in 10 healthy adult male volunteers, aged 18.8 to 30.0 years. The subjects were administered a 5 mg\\/kg dose of caffeine as either an aqueous oral solution or an intravenous infusion, on separate occasions about 1 week apart, in a randomized crossover fashion. Plasma samples were collected over the 24-h period

J. Blanchard; S. J. A. Sawers

1983-01-01

139

PROJECTIVE ABSOLUTENESS UNDER SACKS DAISUKE IKEGAMI  

E-print Network

M), to construct the transitive model M[G] of ZFC (called a generic extension). M[G] is the smallest transitive model of ZFC such that M M[G] and G M[G]. Furthermore M[G] is a model on whose properties we-generic filter G over M, is true in M is true in M[G]. If a statement is absolute under some forcing extension

Amsterdam, University of

140

Measurement of absolute gravity acceleration in Firenze  

NASA Astrophysics Data System (ADS)

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 University of Firenze (Italy). In these laboratories, two separate experiments aiming at measuring the Newtonian constant and testing the Newtonian law at short distances are in progress. Both experiments require an independent knowledge on the local value of g. The only available datum, pertaining to the italian zero-order gravity network, was taken more than 20 years ago at a distance of more than 60 km from the study site. 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.

de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

2011-01-01

141

Determination of the absolute contours of optical flats  

NASA Technical Reports Server (NTRS)

Emersons procedure is used to determine true absolute contours of optical flats. Absolute contours of standard flats are determined and a comparison is then made between standard and unknown flats. Contour differences are determined by deviation of Fizeau fringe.

Primak, W.

1969-01-01

142

From Bi-immunity to Absolute Undecidability Laurent Bienvenu  

E-print Network

From Bi-immunity to Absolute Undecidability Laurent Bienvenu , Adam R. Day , Rupert H¨olzl October- pute A on a set of positions of positive upper density. Absolute undecidability is a weakening of bi-immunity. Downey, Jockusch and Schupp [2] asked whether, unlike the case for bi-immunity, there is an absolutely

Paris-Sud XI, Université de

143

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)

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.

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

2006-03-01

144

A very fast and accurate rigorous EMF simulator for EUVL masks based on the pseudo-spectral time-domain method  

NASA Astrophysics Data System (ADS)

Computer simulation can be very useful for developing a better understanding of the printability of buried defects in EUVL masks. At present, the most widely used rigorous methods for this purpose are the finite-difference time-domain (FDTD) and the rigorous coupled wave analysis (RCWA) methods. However, both of these methods require huge computation resources to simulate large 3D EUVL masks accurately. In this paper, a new rigorous EMF simulator based on the pseudo-spectral time-domain (PSTD) method is discussed. PSTD is free from the grid-snapping and numerical-dispersion errors that plague FDTD and has an accuracy equal to that of RCWA. Also, PSTD requires relatively little computer memory and, furthermore, is well suited to parallization on both multi-core CPU and multi-GPU platforms.

Yeung, Michael; Barouch, Eytan

2013-06-01

145

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

NASA Astrophysics Data System (ADS)

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.

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

2007-03-01

146

Absolute Radiometric Calibration of EUNIS-06  

NASA Technical Reports Server (NTRS)

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.

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

2007-01-01

147

Absolute calibration of the Auger fluorescence detectors  

SciTech Connect

Absolute calibration of the Pierre Auger Observatory fluorescence detectors uses a light source at the telescope aperture. The technique accounts for the combined effects of all detector components in a single measurement. The calibrated 2.5 m diameter light source fills the aperture, providing uniform illumination to each pixel. The known flux from the light source and the response of the acquisition system give the required calibration for each pixel. In the lab, light source uniformity is studied using CCD images and the intensity is measured relative to NIST-calibrated photodiodes. Overall uncertainties are presently 12%, and are dominated by systematics.

Bauleo, P.; Brack, J.; Garrard, L.; Harton, J.; Knapik, R.; Meyhandan, R.; Rovero, A.C.; /Buenos Aires, IAFE; Tamashiro, A.; Warner, D.

2005-07-01

148

Distances and absolute magnitudes from trigonometric parallaxes  

E-print Network

We first review the current knowledge of Hipparcos systematic and random errors, in particular small-scale correlations. Then, assuming Gaussian parallax errors and using examples from the recent Hipparcos literature, we show how random errors may be misinterpreted as systematic errors, or transformed into systematic errors. Finally we summarise how to get unbiased estimates of absolute magnitudes and distances, using either Bayesian or non-parametrical methods. These methods may be applied to get either mean quantities or individual estimates. In particular, we underline the notion of astrometry-based luminosity, which avoids the truncation biases and allows a full use of Hipparcos samples.

F. Arenou; X. Luri

1998-12-04

149

Absolute Priority for a Vehicle in VANET  

NASA Astrophysics Data System (ADS)

In today's world, traffic jams waste hundreds of hours of our life. This causes many researchers try to resolve the problem with the idea of Intelligent Transportation System. For some applications like a travelling ambulance, it is important to reduce delay even for a second. In this paper, we propose a completely infrastructure-less approach for finding shortest path and controlling traffic light to provide absolute priority for an emergency vehicle. We use the idea of vehicular ad-hoc networking to reduce the imposed travelling time. Then, we simulate our proposed protocol and compare it with a centrally controlled traffic light system.

Shirani, Rostam; Hendessi, Faramarz; Montazeri, Mohammad Ali; Sheikh Zefreh, Mohammad

150

Continuum limit of electrostatic gyrokinetic absolute equilibrium  

SciTech Connect

Electrostatic gyrokinetic absolute equilibria with continuum velocity field are obtained through the partition function and through the Green function of the functional integral. The new results justify and explain the prescription for quantization/discretization or taking the continuum limit of velocity. The mistakes in the Appendix D of our earlier work [J.-Z. Zhu and G. W. Hammett, Phys. Plasmas 17, 122307 (2010)] are explained and corrected. If the lattice spacing for discretizing velocity is big enough, all the invariants could concentrate at the lowest Fourier modes in a negative-temperature state, which might indicate a possible variation of the dual cascade picture in 2D plasma turbulence.

Zhu Jianzhou [Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China)

2012-06-15

151

Absolute method of measuring magnetic susceptibility  

USGS Publications Warehouse

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.

Thorpe, A.; Senftle, F.E.

1959-01-01

152

Ultrahigh-resolution Cartesian absolute optical encoder  

NASA Astrophysics Data System (ADS)

A new optical encoder which measures absolute, true-Cartesian displacement with ultra-high sensitivity and linearity has been developed at NASA"s Goddard Space Flight Center. The device is the two-dimensional analog of recently developed linear and rotary encoders based on optical pattern recognition. In this encoder, a glass scale carrying absolute Cartesian position information travels with the payload in an X-Y motion system. Because the scale comprises the entire measurement coordinate system in a monolithic form, motion control axes can be skew to one another to an arbitrary degree and can exhibit substantial lateral drift with no effect on the correctness of X-Y readout, thus eliminating challenges of orthogonal mounting for motion axes and challenges of mounting independent encoders parallel to the directions of travel for each constituent X and Y axis. Prototype devices with ranges of 30 x 30 mm and 150 x 150 mm with 5 nm and 50 nm resolutions, respectively, have been built in the laboratory. Performance data from the Cartesian encoder in the Point Target Assembly for the optical calibration stimulus for Hubble Space Telescope"s Wide Field Camera 3 are presented.

Leviton, Douglas B.; Kirk, Jeff; Lobsinger, Luke

2003-11-01

153

The absolute threshold of cone vision.  

PubMed

We report measurements of the absolute threshold of cone vision, which has been previously underestimated due to suboptimal conditions or overly strict subjective response criteria. We avoided these limitations by using optimized stimuli and experimental conditions while having subjects respond within a rating scale framework. Small (1' fwhm), brief (34 ms), monochromatic (550 nm) stimuli were foveally presented at multiple intensities in dark-adapted retina for 5 subjects. For comparison, 4 subjects underwent similar testing with rod-optimized stimuli. Cone absolute threshold, that is, the minimum light energy for which subjects were just able to detect a visual stimulus with any response criterion, was 203 ± 38 photons at the cornea, ~0.47 log unit lower than previously reported. Two-alternative forced-choice measurements in a subset of subjects yielded consistent results. Cone thresholds were less responsive to criterion changes than rod thresholds, suggesting a limit to the stimulus information recoverable from the cone mosaic in addition to the limit imposed by Poisson noise. Results were consistent with expectations for detection in the face of stimulus uncertainty. We discuss implications of these findings for modeling the first stages of human cone vision and interpreting psychophysical data acquired with adaptive optics at the spatial scale of the receptor mosaic. PMID:21270115

Koenig, Darren; Hofer, Heidi

2011-01-01

154

Experimental results for absolute cylindrical wavefront testing  

NASA Astrophysics Data System (ADS)

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.

Reardon, Patrick J.; Alatawi, Ayshah

2014-09-01

155

Twisted absolute instability in lifted flames  

NASA Astrophysics Data System (ADS)

The theory of resonant modes is extended to finite length systems containing pinch points of complex axial wavenumber k0 and frequency ?0 with arbitrary ?kk0=?2? /?k2. The quantity ?kk0 is shown to be an important indicator of how streamwise boundary conditions modify the local absolute mode at (k0,?0). In particular, when Im(?kk0)>0, the pinch point is twisted, and resonant modes owing to streamwise boundary conditions may then have growth rates greater than that of the unbounded absolute mode. In this case, global instability may occur while the flow is only convectively unstable. The premixing zone between the nozzle and a lifted flame on a variable-density jet is an example of a streamwise-confined system containing a twisted pinch point. For this system, linear stability analysis is employed to locate resonant modes along a solution curve in the complex k and ? planes. The orientation of the solution curve predicts destabilization owing to streamwise confinement as well as increasing global frequency with decreasing lift-off height as observed in previous direct numerical simulations. The theory also suggests that low-frequency fluctuations observed in the simulations may be explained by beating between two resonant modes of slightly differing frequencies.

Nichols, Joseph W.; Chomaz, Jean-Marc; Schmid, Peter J.

2009-01-01

156

An absolute cavity pyrgeometer to measure the absolute outdoor longwave irradiance with traceability to international system of units, SI  

NASA Astrophysics Data System (ADS)

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° 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 (U95) of ±3.96 W m-2 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/m2 lower than that measured by the two pyrgeometers that are traceable to WISG, with a standard deviation of ±0.7 W m-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.

Reda, Ibrahim; Zeng, Jinan; Scheuch, Jonathan; Hanssen, Leonard; Wilthan, Boris; Myers, Daryl; Stoffel, Tom

2012-03-01

157

Absolute instability of a viscous hollow jet.  

PubMed

An investigation of the spatiotemporal stability of hollow jets in unbounded coflowing liquids, using a general dispersion relation previously derived, shows them to be absolutely unstable for all physical values of the Reynolds and Weber numbers. The roots of the symmetry breakdown with respect to the liquid jet case, and the validity of asymptotic models are here studied in detail. Asymptotic analyses for low and high Reynolds numbers are provided, showing that old and well-established limiting dispersion relations [J. W. S. Rayleigh, The Theory of Sound (Dover, New York, 1945); S. Chandrasekhar, Hydrodynamic and Hydromagnetic Stability (Dover, New York, 1961)] should be used with caution. In the creeping flow limit, the analysis shows that, if the hollow jet is filled with any finite density and viscosity fluid, a steady jet could be made arbitrarily small (compatible with the continuum hypothesis) if the coflowing liquid moves faster than a critical velocity. PMID:17358457

Gañán-Calvo, Alfonso M

2007-02-01

158

Absolute instability of a viscous hollow jet  

NASA Astrophysics Data System (ADS)

An investigation of the spatiotemporal stability of hollow jets in unbounded coflowing liquids, using a general dispersion relation previously derived, shows them to be absolutely unstable for all physical values of the Reynolds and Weber numbers. The roots of the symmetry breakdown with respect to the liquid jet case, and the validity of asymptotic models are here studied in detail. Asymptotic analyses for low and high Reynolds numbers are provided, showing that old and well-established limiting dispersion relations [J. W. S. Rayleigh, The Theory of Sound (Dover, New York, 1945); S. Chandrasekhar, Hydrodynamic and Hydromagnetic Stability (Dover, New York, 1961)] should be used with caution. In the creeping flow limit, the analysis shows that, if the hollow jet is filled with any finite density and viscosity fluid, a steady jet could be made arbitrarily small (compatible with the continuum hypothesis) if the coflowing liquid moves faster than a critical velocity.

Gañán-Calvo, Alfonso M.

2007-02-01

159

Absolute radiometric calibration of the Thematic Mapper  

NASA Technical Reports Server (NTRS)

Calibration data for the solar reflective bands of the Landsat-5 TM obtained from five in-flight absolute radiometric calibrations from July 1984-November 1985 at White Sands, New Mexico are presented and analyzed. Ground reflectance and atmospheric data were utilized to predict the spectral radiance at the entrance pupil of the TM and the average number of digital counts in each TM band. The calibration of each of the TM solar reflective bands was calculated in terms of average digital counts/unit spectral radiance for each band. It is observed that for the 12 reflectance-based measurements the rms variation from the means as a percentage of the mean is + or - 1.9 percent; for the 11 measurements in the IR bands, it is + or - 3.4 percent; and the rms variation for all 23 measurements is + or - 2.8 percent.

Slater, P. N.; Biggar, S. F.; Holm, R. G.; Jackson, R. D.; Mao, Y.

1986-01-01

160

Absolute beam current monitoring in endstation c  

SciTech Connect

The first few experiments at CEBAF require approximately 1% absolute measurements of beam currents expected to range from 10-25{mu}A. This represents errors of 100-250 nA. The initial complement of beam current monitors are of the non intercepting type. CEBAF accelerator division has provided a stripline monitor and a cavity monitor, and the authors have installed an Unser monitor (parametric current transformer or PCT). After calibrating the Unser monitor with a precision current reference, the authors plan to transfer this calibration using CW beam to the stripline monitors and cavity monitors. It is important that this be done fairly rapidly because while the gain of the Unser monitor is quite stable, the offset may drift on the order of .5{mu}A per hour. A summary of what the authors have learned about the linearity, zero drift, and gain drift of each type of current monitor will be presented.

Bochna, C.

1995-04-01

161

In vivo absorption spectroscopy for absolute measurement  

PubMed Central

In in vivo spectroscopy, there are differences between individual subjects in parameters such as tissue scattering and sample concentration. We propose a method that can provide the absolute value of a particular substance concentration, independent of these individual differences. Thus, it is not necessary to use the typical statistical calibration curve, which assumes an average level of scattering and an averaged concentration over individual subjects. This method is expected to greatly reduce the difficulties encountered during in vivo measurements. As an example, for in vivo absorption spectroscopy, the method was applied to the reflectance measurement in retinal vessels to monitor their oxygen saturation levels. This method was then validated by applying it to the tissue phantom under a variety of absorbance values and scattering efficiencies. PMID:23082298

Furukawa, Hiromitsu; Fukuda, Takashi

2012-01-01

162

Convective Versus Absolute Instability in Mixed Rayleigh-Bénard-Poiseuille Convection  

NASA Astrophysics Data System (ADS)

We investigate the absolute and convective nature of thermal convection rolls of different orientation relative to a mean unidirectional Poiseuille flow through a large Rayleigh-Bénard cell. This question has first been addressed for transverse rolls (TR's) by Müller (1990) who found that for Re>0 the first bifurcation at Ra_crit(Re) leads to convectively unstable TR's, while the transition to absolute instability takes place at a higher Ra_abs>Ra_crit. For longitudinal rolls the question has not yet been fully clarified, due in part to the fact that the linear stability problem for streamwise rolls reduces to the no-flow problem. We show that streamwise rolls do not become absolutely unstable at Ra_crit. Using a generalized analytic dispersion relation as well as direct numerical integration, we determine the 2-D impulse response of the system by applying Brigg's method in the two horizontal wave number planes. We show that, at the transition to absolute instability, the mode with zero group velocity found at the tail of the wave packet is a TR. The implications of these findings for experiments will be discussed.

Monkewitz, P. A.; Carrière, Ph.

1997-11-01

163

Directly Relating Gas-Phase Cluster Measurements to Solution-Phase Hydrolysis, the Absolute Standard Hydrogen Electrode Potential, and the Absolute Proton Solvation Energy  

PubMed Central

Solution-phase, half-cell potentials are measured relative to other half-cell potentials, resulting in a thermochemical ladder that is anchored to the standard hydrogen electrode (SHE), which is assigned an arbitrary value of 0 V. A new method for measuring the absolute SHE potential is demonstrated in which gaseous nanodrops containing divalent alkaline-earth or transition-metal ions are reduced by thermally generated electrons. Energies for the reactions 1) M-(H2O)242+(g)+e?(g)?M(H2O)24+(g) and 2) M(H2O)242+(g)+e?(g)?MOH(H2O)23+(g)+H(g) and the hydrogen atom affinities of MOH(H2O)23+(g) are obtained from the number of water molecules lost through each pathway. From these measurements on clusters containing nine different metal ions and known thermochemical values that include solution hydrolysis energies, an average absolute SHE potential of +4.29 V vs. e?(g) (standard deviation of 0.02 V) and a real proton solvation free energy of ?265 kcal mol?1 are obtained. With this method, the absolute SHE potential can be obtained from a one-electron reduction of nanodrops containing divalent ions that are not observed to undergo one-electron reduction in aqueous solution. PMID:19440999

Donald, William A.; Leib, Ryan D.; O’Brien, Jeremy T.; Williams, Evan R.

2009-01-01

164

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

NASA Astrophysics Data System (ADS)

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.

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

2010-11-01

165

Ultrahigh resolution absolute Cartesian electronic autocollimator  

Microsoft Academic Search

The development of a compact, ultra-high resolution, electronic autocollimator with excellent readout stability, linearity, and coordinate orthogonality is presented. This optical metrology tool relies on new advances in Cartesian optical encoders based on pattern recognition technology. Readout instabilities characteristic of conventional electronic autocollimators whose lateral effect photodetectors and operational amplifiers exhibit temporal and thermal drifts, are absent in this new

Douglas B. Leviton

2003-01-01

166

Absolute nuclear material assay using count distribution (LAMBDA) space  

DOEpatents

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.

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

2012-06-05

167

Absolute brightness temperature measurements at 3.5-mm wavelength. [of sun, Venus, Jupiter and Saturn  

NASA Technical Reports Server (NTRS)

Careful observations have been made at 86.1 GHz to derive the absolute brightness temperatures of the sun (7914 + or - 192 K), Venus (357.5 + or - 13.1 K), Jupiter (179.4 + or - 4.7 K), and Saturn (153.4 + or - 4.8 K) with a standard error of about three percent. This is a significant improvement in accuracy over previous results at millimeter wavelengths. A stable transmitter and novel superheterodyne receiver were constructed and used to determine the effective collecting area of the Millimeter Wave Observatory (MWO) 4.9-m antenna relative to a previously calibrated standard gain horn. The thermal scale was set by calibrating the radiometer with carefully constructed and tested hot and cold loads. The brightness temperatures may be used to establish an absolute calibration scale and to determine the antenna aperture and beam efficiencies of other radio telescopes at 3.5-mm wavelength.

Ulich, B. L.; Rhodes, P. J.; Davis, J. H.; Hollis, J. M.

1980-01-01

168

Absolute measurement of surface and bulk absorption in DUV optics from temperature induced wavefront deformation.  

PubMed

A measurement system for quantitative determination of both surface and bulk contributions to the photo-thermal absorption in DUV optics was developed. It is based upon a Hartmann-Shack wavefront sensor with a sensitivity of ~?/10000 rms, accomplishing precise on-line monitoring of wavefront deformations of a collimated test laser beam transmitted perpendicular through the excimer laser-irradiated site of a cuboid sample. Caused by the temperature dependence of the refractive index as well as thermal expansion, the initially plane wavefront of the test laser is distorted into a cylindrical shape, with bending ends towards the surface. Sign and magnitude depend on index change and expansion. By comparison with thermal theory, this transient wavefront distortion yields a quantitative absolute measure of bulk and surface absorption losses in the sample. First rresults for fused silica are presented. PMID:20941050

Schäfer, Bernd; Schöneck, Matthias; Bayer, Armin; Mann, Klaus

2010-10-11

169

Absolute configuration of naturally occurring glabridin.  

PubMed

The title compound {systematic name: 4-[(3R)-8,8-dimethyl-3,4-dihydro-2H-pyrano[2,3-f]chromen-3-yl]benzene-1,3-diol, commonly named glabridin}, C20H20O4, is a species-specific biomarker from the roots Glycyrrhiza glabra L. (European licorice, Fabaceae). In the present study, this prenylated isoflavan has been purified from an enriched CHCl3 fraction of the extract of the root, using three steps of medium-pressure liquid chromatography (MPLC) by employing HW-40F, Sephadex LH-20 and LiChroCN as adsorbents. Pure glabridin was crystallized from an MeOH-H2O mixture (95:5?v/v) to yield colorless crystals containing one molecule per asymmetric unit (Z' = 1) in the space group P212121. Although the crystal structure has been reported before, the determination of the absolute configuration remained uncertain. Stereochemical analysis, including circular dichroism, NMR data and an X-ray diffraction data set with Bijvoet differences, confirms that glabridin, purified from its natural source, is found only in a C3 R configuration. These results can therefore be used as a reference for the assignment of the configuration and enantiopurity of any isolated or synthetic glabridin sample. PMID:24192160

Simmler, Charlotte; Fronczek, Frank R; Pauli, Guido F; Santarsiero, Bernard D

2013-11-01

170

An Apparatus for Absolute Neutron Flux Measurement  

NASA Astrophysics Data System (ADS)

A fully-absorbing neutron detector is being developed to measure the absolute flux (s-1) of a cold neutron beam at the level of 0.1,%. The device will be used to calibrate a neutron flux monitor used in an in-beam neutron lifetime measurement performed at NIST (?n= (886.3 ±3.4) s). The precision of the measurement was limited by the uncertainty in the efficiency of the neutron flux monitor (0.3,%). The flux monitor operates by counting charged particles produced when neutrons impinge on a ^6Li (or ^10B) foil. Its efficiency was calculated from the cross section, the solid angle subtended by the charged particle detectors, and the amount of neutron-absorbing material present on the foil. Successful calibration would reduce the neutron lifetime uncertainty to approximately 0.25,%. In addition, using the measured solid angle and amount of material on the deposit, a new experimental value for the ^6Li or (^10B) capture cross section will be obtained. Details of the apparatus and the measurement technique along with the status of the experiment will be discussed.

Yue, A.; Greene, G.; Dewey, M. S.; Gilliam, D.; Nico, J.; Laptev, A.

2007-10-01

171

Absolute quantum energy inequalities in curved spacetime  

E-print Network

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.

Christopher J. Fewster; Calvin J. Smith

2007-02-09

172

Absolute calibration of forces in optical tweezers  

NASA Astrophysics Data System (ADS)

Optical tweezers are highly versatile laser traps for neutral microparticles, with fundamental applications in physics and in single molecule cell biology. Force measurements are performed by converting the stiffness response to displacement of trapped transparent microspheres, employed as force transducers. Usually, calibration is indirect, by comparison with fluid drag forces. This can lead to discrepancies by sizable factors. Progress achieved in a program aiming at absolute calibration, conducted over the past 15 years, is briefly reviewed. Here we overcome its last major obstacle, a theoretical overestimation of the peak stiffness, within the most employed range for applications, and we perform experimental validation. The discrepancy is traced to the effect of primary aberrations of the optical system, which are now included in the theory. All required experimental parameters are readily accessible. Astigmatism, the dominant effect, is measured by analyzing reflected images of the focused laser spot, adapting frequently employed video microscopy techniques. Combined with interface spherical aberration, it reveals a previously unknown window of instability for trapping. Comparison with experimental data leads to an overall agreement within error bars, with no fitting, for a broad range of microsphere radii, from the Rayleigh regime to the ray optics one, for different polarizations and trapping heights, including all commonly employed parameter domains. Besides signaling full first-principles theoretical understanding of optical tweezers operation, the results may lead to improved instrument design and control over experiments, as well as to an extended domain of applicability, allowing reliable force measurements, in principle, from femtonewtons to nanonewtons.

Dutra, R. S.; Viana, N. B.; Maia Neto, P. A.; Nussenzveig, H. M.

2014-07-01

173

Thermodynamic data from redox reactions at high temperatures. III. Activity-composition relations in Ni-Pd alloys from EMF measurements at 850–1250 K, and calibration of the NiO+Ni-Pd assemblage as a redox sensor  

Microsoft Academic Search

The assemblage NiO+Ni-Pd alloy has been calibrated as a precise oxygen fugacity sensor in the temperature range 850–1250 K at 1 bar, using an electrochemical technique with oxygen-specific CSZ electrolytes, and Ni+NiO and Cu+Cu2O as the reference electrodes. Nine compositions were studied, ranging from 0.12 to 0.83 XNialloy. Steady EMFs, implying equilibrium, were rapidly achieved in all cells, and were

Mark I. Pownceby; Hugh St. C. O'Neill

1994-01-01

174

Absolute calorimetric calibration of low energy brachytherapy sources  

NASA Astrophysics Data System (ADS)

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.

Stump, Kurt E.

175

Thermal properties measurements in biodiesel oils using photothermal techniques  

NASA Astrophysics Data System (ADS)

In this Letter, thermal lens and open cell photoacoustic techniques are used to measure the thermal properties of biodiesel oils. The absolute values of the thermal effusivity, thermal diffusivity, thermal conductivity and the temperature coefficient of the refractive index were determined for samples obtained from soy, castor bean, sunflower and turnip. The results suggest that the employed techniques may be useful as complementary methods for biodiesel certification.

Castro, M. P. P.; Andrade, A. A.; Franco, R. W. A.; Miranda, P. C. M. L.; Sthel, M.; Vargas, H.; Constantino, R.; Baesso, M. L.

2005-08-01

176

Determination of Absolute Zero Using a Computer-Based Laboratory  

ERIC Educational Resources Information Center

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…

Amrani, D.

2007-01-01

177

Absolute calibration of analog detectors using stimulated parametric down conversion  

Microsoft Academic Search

Spontaneous parametric down conversion has been largely exploited as a tool for absolute calibration of photon counting detectors, photomultiplier tubes or avalanche photodiodes working in Geiger regime. In this work we investigate the extension of this technique from very low photon flux of photon counting regime to the absolute calibration of analog photodetectors at higher photon flux. Moving toward higher

G. Brida; M. Chekhova; M. Genovese; M.-L. Rastello; I. Ruo-Berchera

2009-01-01

178

Safety Logics I: Absolute Safety Zhisheng Huang and John Bell #  

E-print Network

medical safety­critical system would consider states in which the patient dies as a result of treatmentSafety Logics I: Absolute Safety Zhisheng Huang and John Bell # Applied Logic Group Department}@dcs.qmw.ac.uk Abstract In this paper we distinguish between absolute safety and normative safety, and develop a formal

Huang, Zhisheng

179

Quantifying Absolute Protein Synthesis Rates Reveals Principles Underlying  

E-print Network

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

Zhang, Jianzhi

180

Evaluation of the Absolute Regional Temperature Potential  

NASA Technical Reports Server (NTRS)

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.

Shindell, D. T.

2012-01-01

181

Absolute optical surface measurement with deflectometry  

NASA Astrophysics Data System (ADS)

Deflectometry utilises the deformation and displacement of a sample pattern after reflection from a test surface to infer the surface slopes. Differentiation of the measurement data leads to a curvature map, which is very useful for surface quality checks with sensitivity down to the nanometre range. Integration of the data allows reconstruction of the absolute surface shape, but the procedure is very error-prone because systematic errors may add up to large shape deviations. In addition, there are infinitely many combinations for slope and object distance that satisfy a given observation. One solution for this ambiguity is to include information on the object's distance. It must be known very accurately. Two laser pointers can be used for positioning the object, and we also show how a confocal chromatic distance sensor can be used to define a reference point on a smooth surface from which the integration can be started. The used integration algorithm works without symmetry constraints and is therefore suitable for free-form surfaces as well. Unlike null testing, deflectometry also determines radius of curvature (ROC) or focal lengths as a direct result of the 3D surface reconstruction. This is shown by the example of a 200 mm diameter telescope mirror, whose ROC measurements by coordinate measurement machine and deflectometry coincide to within 0.27 mm (or a sag error of 1.3?m). By the example of a diamond-turned off-axis parabolic mirror, we demonstrate that the figure measurement uncertainty comes close to a well-calibrated Fizeau interferometer.

Li, Wansong; Sandner, Marc; Gesierich, Achim; Burke, Jan

182

Development of a graphite probe calorimeter for absolute clinical dosimetry  

SciTech Connect

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.

Renaud, James; Seuntjens, Jan; Sarfehnia, Arman [Medical Physics Unit, McGill University, Montreal, Quebec H3G 1A4 (Canada); Marchington, David [Ionizing Radiation Standards, National Research Council of Canada, Ottawa, Ontario K1A 0R6 (Canada)

2013-02-15

183

Absolute Abundance Measurements in Solar Flares  

NASA Astrophysics Data System (ADS)

We present measurements of elemental abundances in solar flares with EVE/SDO and EIS/Hinode. EVE observes both high temperature Fe emission lines Fe XV-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. Furthermore, we have compared the EVE measurements with corresponding flare observations of intermediate temperature S, Ar, Ca, and Fe emission lines taken with EIS. Our initial calculations also indicate a photospheric composition for these observations. 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 in the non-flaring corona occurs.

Warren, Harry

2014-06-01

184

Measurements of Absolute Abundances in Solar Flares  

NASA Astrophysics Data System (ADS)

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.

Warren, Harry P.

2014-05-01

185

Kinetic regularities of thermal transformations in nanosized lead films  

NASA Astrophysics Data System (ADS)

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.

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

2015-01-01

186

Absolute instability in viscoelastic mixing layers  

NASA Astrophysics Data System (ADS)

The spatiotemporal linear stability of viscoelastic planar mixing layers is investigated. A one-parameter family of velocity profiles is used as the base state with the parameter, S, controlling the amount of shear and backflow. The influence of viscoelasticity in dilute polymer solutions is modeled with the Oldroyd-B and FENE-P constitutive equations. Both models require the specification of the ratio of the polymer-relaxation and convective time scales (the Weissenberg number, We) and the ratio of solvent and solution viscosities (?). The maximum polymer extensibility, L, must also be specified for the FENE-P model. We examine how the variation of these parameters along with the Reynolds number, Re, affects the minimum value of S at which the flow becomes locally absolutely unstable. With the Oldroyd-B model, the influence of viscoelasticity is shown to be almost fully captured by the elasticity, E^* equiv (1-? ) We/Re, and Scrit decreases as elasticity is increased, i.e., elasticity is destabilizing. A simple approximate dispersion relation obtained via long-wave asymptotic analysis is shown to accurately capture this destabilizing influence. Results obtained with the FENE-P model exhibit a rich variety of behavior. At large values of the extensibility, L, results are similar to those for the Oldroyd-B fluid as expected. However, when the extensibility is reduced to more realistic values (L ? 100), one must consider the scaled shear rate, ? _c equiv We S/2L, in addition to the elasticity. When ?c is large, the base-state polymer stress obtained by the FENE-P model is reduced, and there is a corresponding reduction in the overall influence of viscoelasticity on stability. Additionally, elasticity exhibits a stabilizing effect which is driven by the streamwise-normal perturbation polymer stress. As ?c is reduced, the base-state and perturbation normal polymer stresses predicted by the FENE-P model move towards the Oldroyd-B values, and the destabilizing influence of elasticity observed with the Oldroyd-B model is again present.

Ray, Prasun K.; Zaki, Tamer A.

2014-01-01

187

Ultrahigh resolution absolute Cartesian electronic autocollimator  

NASA Astrophysics Data System (ADS)

The development of a compact, ultra-high resolution, electronic autocollimator with excellent readout stability, linearity, and coordinate orthogonality is presented. This optical metrology tool relies on new advances in Cartesian optical encoders based on pattern recognition technology. Readout instabilities characteristic of conventional electronic autocollimators whose lateral effect photodetectors and operational amplifiers exhibit temporal and thermal drifts, are absent in this new technology. An autocollimator with a form factor similar to conventional alignment telescopes has been demonstrated with an angular resolution of 0.02 arcseconds peak-to-peak and less than 0.01 arcseconds rms. Various optical metrology applications for the laboratory and for space flight, including cryostatic ones, are described.

Leviton, Douglas B.

2003-11-01

188

Transition to Absolute Instability for (not so) Dummies  

E-print Network

These notes are intended as an elementary introduction to the concept of absolute instability. The transition from convective instability to absolute instability is an important issue when the stability of stationary flow solutions is investigated. The arguments here described were first developed in the framework of plasma physics and later applied to the hydrodynamics of mixing layers and shear flows. Far from being a comprehensive analysis of this complicated subject, the aim of these notes is just to sketch a rudimentary and quite elementary ground for physicists or engineers which have a familiarity with the basic features of linear stability in fluid dynamics, but are new to the concept of absolute instability.

Barletta, Antonio

2014-01-01

189

ABSOLUTE PROPERTIES OF THE ECCENTRIC ECLIPSING BINARY STAR FT ORIONIS  

SciTech Connect

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.

Sabby, Jeffrey A. [Physics Department, Southern Illinois University Edwardsville, Edwardsville, IL 62025 (United States); Lacy, Claud H. Sandberg [Physics Department, University of Arkansas, Fayetteville, AR 72701 (United States); Ibanoglu, Cafer [Astronomy and Space Sciences Department, Science Faculty, Ege University, 35100 Boronova, Izmir (Turkey); Claret, Antonio, E-mail: jsabby@siue.edu, E-mail: clacy@uark.edu, E-mail: cafer.ibanoglu@ege.edu.tr, E-mail: claret@iaa.es [Instituto de Astrofisica de Andalucia, CSIC, Apdo. Postal 3004, E-18080 Granada (Spain)

2011-06-15

190

Measurement of Disintegration Rates and Absolute {gamma}-ray Intensities  

SciTech Connect

The majority of practical radioactive materials decay by modes that include {gamma}-ray emission. For questions of 'how much' or 'how pure', one must know the absolute intensities of the major radiations. We are using liquid scintillation counting (LSC) to measurements of disintegration rates, coupled with {gamma}-ray spectroscopy to measure absolute {gamma}-ray emission probabilities. Described is a study of the 227Th chain yielding absolute {gamma}-ray intensities with {approx}0.5% accuracy and information on LSC efficiencies.

DeVries, Daniel J.; Griffin, Henry C. [Department of Chemistry, University of Michigan, Ann Arbor, MI 48109 (United States)

2006-03-13

191

Mini-implants and miniplates generate sub-absolute and absolute anchorage  

PubMed Central

The functional demand imposed on bone promotes changes in the spatial properties of osteocytes as well as in their extensions uniformly distributed throughout the mineralized surface. Once spatial deformation is established, osteocytes create the need for structural adaptations that result in bone formation and resorption that happen to meet the functional demands. The endosteum and the periosteum are the effectors responsible for stimulating adaptive osteocytes in the inner and outer surfaces.Changes in shape, volume and position of the jaws as a result of skeletal correction of the maxilla and mandible require anchorage to allow bone remodeling to redefine morphology, esthetics and function as a result of spatial deformation conducted by orthodontic appliances. Examining the degree of changes in shape, volume and structural relationship of areas where mini-implants and miniplates are placed allows us to classify mini-implants as devices of subabsolute anchorage and miniplates as devices of absolute anchorage. PMID:25162561

Consolaro, Alberto

2014-01-01

192

Direct comparisons between absolute and relative geomagnetic paleointensities: Absolute calibration of a relative paleointensity stack  

NASA Astrophysics Data System (ADS)

Absolute geomagnetic paleointensities (APIs) have been estimated from igneous rocks, while relative paleomagnetic intensities (RPIs) have been reported from sediment cores. These two datasets have been treated separately, as correlations between APIs and RPIs are difficult on account of age uncertainties. High-resolution RPI stacks have been constructed from globally distributed sediment cores with high sedimentation rates. Previous studies often assumed that the RPI stacks have a linear relationship with geomagnetic axial dipole moments, and calibrated the RPI values to API values. However, the assumption of a linear relationship between APIs and RPIs has not been evaluated. Also, a quantitative calibration method for the RPI is lacking. We present a procedure for directly comparing API and RPI stacks, thus allowing reliable calibrations of RPIs. Direct comparisons between APIs and RPIs were conducted with virtually no associated age errors using both tephrochronologic correlations and RPI minima. Using the stratigraphic positions of tephra layers in oxygen isotope stratigraphic records, we directly compared the RPIs and APIs reported from welded tuffs contemporaneously extruded with the tephra layers. In addition, RPI minima during geomagnetic reversals and excursions were compared with APIs corresponding to the reversals and excursions. The comparison of APIs and RPIs at these exact points allowed a reliable calibration of the RPI values. We applied this direct comparison procedure to the global RPI stack PISO-1500. For six independent calibration points, virtual axial dipole moments (VADMs) from the corresponding APIs and RPIs of the PISO-1500 stack showed a near-linear relationship. On the basis of the linear relationship, RPIs of the stack were successfully calibrated to the VADMs. The direct comparison procedure provides an absolute calibration method that will contribute to the recovery of temporal variations and distributions of geomagnetic axial dipole moments from RPI stacks for the past several million years.

Mochizuki, N.; Yamamoto, Y.; Hatakeyama, T.; Shibuya, H.

2013-12-01

193

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

NASA Technical Reports Server (NTRS)

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.

Adomian, G.; Miao, C. C.

1973-01-01

194

Temporal Dynamics of Microbial Rhodopsin Fluorescence Reports Absolute Membrane Voltage  

PubMed Central

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

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

2014-01-01

195

Absolutely continuous spectrum of a Schroedinger operator on a tree  

SciTech Connect

We give sufficient conditions for the presence of the absolutely continuous spectrum of a Schroedinger operator on a regular rooted tree without loops (also called regular Bethe lattice or Cayley tree)

Kupin, S. [Universite Aix-Marseille, 39 rue Joliot-Curie, 13453 Marseille Cedex 13 (France)

2008-11-15

196

Absolute dating of the earliest times in China  

Microsoft Academic Search

Based on five lunar eclipses recorded in the Antares calendar, the oldest Chinese calendar, the author presents several absolute datings for the Shang dynasty and the Western Zhou dynasty (1700 - 900 B.C.).

T. Narike

1998-01-01

197

Comparative vs. Absolute Performance Assessment with Environmental Sustainability Metrics  

E-print Network

Comparative vs. Absolute Performance Assessment with Environmental Sustainability Metrics Xun Jin Different goals and potential audiences determine that two types of environmental performance assessments metrics can be partitioned into two camps. One suite of metrics aim to assess the environmental

High, Karen

198

Absolute shape measurements using high-resolution optoelectronic holography methods  

E-print Network

Absolute shape measurements using high- resolution optoelectronic holography methods Cosme Furlong optoelectronic holography (OEH) methodology is described. This description addresses apparatus and analysis holography; shape and deformation measurements; surface tiling. Paper SM-26 received July 30, 1999; revised

Furlong, Cosme

199

Near-Infrared Absolute Photometric Imaging of the Uranian System  

Microsoft Academic Search

We report the first multifilter set of absolutely calibrated near-infrared images of Uranus, its rings, and three major satellites-Titania, Ariel, and Miranda. Along with imagery utilizing the canonical K filter bandpass (effective wavelength 2.20 mum), absolutely calibrated images of the uranian system are presented for the first time for three additional filter bandpasses: J (1.27 mum), H (1.62 mum), and

Kevin H. Baines; Padmavati A. Yanamandra-Fisher; Larry A. Lebofsky; Thomas W. Momary; William Golisch; Charles Kaminski; Walter J. Wild

1998-01-01

200

Absolute calibration of photodetectors: photocurrent multiplication versus photocurrent subtraction  

E-print Network

We report testing of the new absolute method of photodetectors calibration based on the difference-signal measurement for two-mode squeezed vacuum by comparison with the traditional absolute method based on the coincidence counting. Using low-gain parametric down conversion we have measured the quantum efficiency of a counting detector by both methods. The difference-signal method was adapted for the counting detectors by taking into account the dead-time effect.

I. N. Agafonov; M. V. Chekhova; T. Sh. Iskhakov; A. N. Penin; G. O. Rytikov; O. A. Shumilkina

2010-12-15

201

Absolute/convective instability of planar viscoelastic jets  

NASA Astrophysics Data System (ADS)

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.

Ray, Prasun K.; Zaki, Tamer A.

2015-01-01

202

A novel absolute magnetic encoder based on pseudorandom code  

Microsoft Academic Search

In order to improve resolution of multi-pole encoder and realize absolute output, a novel absolute multi-pole encoder structure based on calibration was proposed. Two ring alnicos, defined as look-up table track and index track were used as magnetic source. Look-up table track was magnetized to 8 N-S, three linear evenly placed Hall ICs which air gap is 2 mm are

Yong Liu; Shuanghui Hao; Minghui Hao

2009-01-01

203

Optical absolute difference measurement for gray-scale image matching  

Microsoft Academic Search

In this paper absolute difference measurement (ADM) is proposed for optical gray-scale image recognition. ADM measures the similarity between different gray-scale images and the value of measurement reflects the similarity linearly. Using optical correlation and a novel cycle- encoding method the processing of gray-scale image matching based on absolute difference measurement can be realized simply. This new method can be

Gang Cheng; Guo-Fan Jin; Minxian Wu; Haisong Liu; Qingsheng He

1998-01-01

204

Absolute position measurement using optical detection of coded patterns  

Microsoft Academic Search

Discusses absolute, one- and two-dimensional position measurement using optical detection of coded patterns. A one-dimensional position transducer is described in which both absolute and incremental information are optically encoded on a single track. This concept is extended to a two-dimensional position encoder and both small-scale applications in instrumentation and large-scale applications in the navigation of guided vehicles are described. The

J. T. M. Stevenson; J. R. Jordan

1988-01-01

205

High-performance absolute optical encoder using M-code  

Microsoft Academic Search

We developed a high-resolution absolute optical encode that achieves a resolution of 4,194,304 Division\\/Rev at a diameter of 34mm, based on the new angle detection principles, by which the two sets of interpolation data of two differing cycles and M-Code data are mixed. This absolute encoder also achieves an accuracy of 20 seconds to minimize the sinusoid wave distortion of

Yuji Matsuzoe; Tomoharu Nakayama; Nobuhiko Tsuji; Kouetu Fujita; Toru Yoshizawa

2001-01-01

206

High-performance absolute optical encoder using M-code  

NASA Astrophysics Data System (ADS)

We developed a high-resolution absolute optical encode that achieves a resolution of 4,194,304 Division/Rev at a diameter of 34mm, based on the new angle detection principles, by which the two sets of interpolation data of two differing cycles and M-Code data are mixed. This absolute encoder also achieves an accuracy of 20 seconds to minimize the sinusoid wave distortion of the signal from the photo detector.

Matsuzoe, Yuji; Nakayama, Tomoharu; Tsuji, Nobuhiko; Fujita, Koetsu; Yoshizawa, Toru

2001-10-01

207

Absolutely continuous spectrum for multi-type Galton Watson trees  

E-print Network

We consider multi-type Galton Watson trees that are close to a tree of finite cone type in distribution. Moreover, we impose that each vertex has at least one forward neighbor. Then, we show that the spectrum of the Laplace operator exhibits almost surely a purely absolutely continuous component which is included in the absolutely continuous spectrum of the tree of finite cone type.

Matthias Keller

2012-01-25

208

Absolute and Convective Instability of a Liquid Jet in Microgravity  

NASA Technical Reports Server (NTRS)

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.

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

1996-01-01

209

Quantum refrigerators in quest of the absolute zero  

NASA Astrophysics Data System (ADS)

The second and third laws of thermodynamics can be used to establish a fundamental bound for the maximum possible cooling rate in approaching the absolute zero of temperature. In modeling the behavior of the molecular refrigerators geared toward attaining ultralow temperatures, only quantum mechanical, as opposed to classical physics, models can be admissible. As a simple model, we analyze a three-level quantum refrigerator, and in particular its irreversible thermodynamic performance as absolute zero is approached.

Kosloff, Ronnie; Geva, Eitan; Gordon, Jeffrey M.

2000-06-01

210

On-Orbit Absolute Temperature Calibration Using Multiple Phase Change Materials  

NASA Astrophysics Data System (ADS)

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.

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

2009-12-01

211

An application of Shoenfield's absoluteness theorem to the theory of uniform distribution  

E-print Network

An application of Shoenfield's absoluteness theorem to the theory. Supported by DFG grant Ko 490/7-1 #12; Shoenfield's absoluteness theorem and uniform for logicians, using the technique* * of forcing and Shoenfield's absoluteness theorem for 12-sets

Goldstern, Martin

212

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

PubMed

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(-5) and (1.427 ± 0.009) × 10(-7) m(2) s(-1), respectively, in very good agreement with accepted literature values. PMID:24387453

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

2013-12-01

213

Safety of high speed guided ground transportation systems: An overview of biological effects and mechanisms relevant to EMF exposures from mass transit and electric rail systems. Final report, October 1991-July 1993  

SciTech Connect

The U.S. has implemented a national initiative to develop maglev (magnetic levitation) and other high-speed rail (HSR) systems. There are concerns for potential adverse health effects of the Extremely Low Frequency (3-3,000 Hz) electric and magnetic fields (EMF) produced by these systems. The Environmental Protection Agency's Office of Radiation Programs is assisting the Federal Railroad Administration address these concerns; this comprehensive review is part of that effort. It outlines magnetic field exposure measurements of the TR07 German maglev system compared with other HSR and conventional systems.

Goldberg, R.B.; Creasey, W.A.; Foster, K.R.

1993-08-01

214

EMFs: cutting through the controversy.  

PubMed

SOME SCIENTISTS ALLEGE that exposure to electric and magnetic fields generated by electric power delivery systems is responsible for certain cancers (particularly among children), reproductive dysfunction, birth defects, neurological disorders, and Alzheimer's disease. Some activist groups believe the hazard to be so great that they are calling for closure of schools and other public facilities near power lines and restructuring of the entire electric power delivery system. Some utilities, with equally strong beliefs, claim that there is no proof of risk. They argue that the science is sufficient to confirm the alleged associations and that no action is warranted. This article provides a broad overview of the current scientific data on the association between magnetic fields and disease, providing summary risk estimates and highlighting the uncertainties in the data. Building on this information, three complementary policy perspectives are presented. From a fiscally conservative perspective, the cost of mitigation already instituted far exceeds the health protection offered and mitigation of other environmental risks is more important. From a cost-benefit view, only limited, low-cost mitigation should be considered. These measures, however, would substantially reduce many exposures. From an aggressive exposure reduction perspective, much can be done to reduce exposure by personal and societal actions. If the suggested association is validated, substantially reducing magnetic field exposure could lower health risks. PMID:8643811

Wartenberg, D

1996-01-01

215

EMFs: cutting through the controversy.  

PubMed Central

SOME SCIENTISTS ALLEGE that exposure to electric and magnetic fields generated by electric power delivery systems is responsible for certain cancers (particularly among children), reproductive dysfunction, birth defects, neurological disorders, and Alzheimer's disease. Some activist groups believe the hazard to be so great that they are calling for closure of schools and other public facilities near power lines and restructuring of the entire electric power delivery system. Some utilities, with equally strong beliefs, claim that there is no proof of risk. They argue that the science is sufficient to confirm the alleged associations and that no action is warranted. This article provides a broad overview of the current scientific data on the association between magnetic fields and disease, providing summary risk estimates and highlighting the uncertainties in the data. Building on this information, three complementary policy perspectives are presented. From a fiscally conservative perspective, the cost of mitigation already instituted far exceeds the health protection offered and mitigation of other environmental risks is more important. From a cost-benefit view, only limited, low-cost mitigation should be considered. These measures, however, would substantially reduce many exposures. From an aggressive exposure reduction perspective, much can be done to reduce exposure by personal and societal actions. If the suggested association is validated, substantially reducing magnetic field exposure could lower health risks. Images p205-a p207-a PMID:8643811

Wartenberg, D

1996-01-01

216

SCIENTIFIC CORRESPONDENCE Ferromagnetism and EMFs  

E-print Network

device (SQUID) magnetometers to quantify trace levels of magnetite in various biological and laboratory (flasks, pipettes, centrifuge tubes, and so on) and commercially prepared culture media in tissue them with the cells dur- ing centrifugation. As an example, in a sham experiment we used 50 ml of leuko

217

Absolute irradiance of the Moon for on-orbit calibration  

USGS Publications Warehouse

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.

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

2002-01-01

218

Absolute Neutron Emission Measurement in Burning Plasma Experiments  

NASA Astrophysics Data System (ADS)

The absolute measurement of neutron emission rate from the whole plasma is a very important diagnostics as a fusion power monitor in fusion experimental devices with D-T or D-T operations. Here measurement techniques of time-resolved and time-integrated absolute neutron emission on the present tokamaks and ITER are reviewed. In the present tokamaks, fission chamber installed outside the vacuum vessel are very popular in the absolute neutron emission rate measurement. As well as conventional neutron monitors installed outside the vacuum vessel, in-vessel neutron monitors using micro fission chamber are proposed for the absolute neutron emission rate measurement in ITER. The neutron activation system provides time-integrated measurements of the total neutron yield with high accuracy by using well known neutron reaction cross sections, which is useful to maintain a robust measure of fusion energy production with stability and wide dynamic range. The calibration of the relation between the neutron emission rate in the whole plasma and the output of neutron monitor is the most important issue in the absolute neutron emission rate measurements. The calibration of the neutron detectors has been performed by moving a neutron source such as a 252Cf neutron or a small accelerator-based neutron generator. For the calibration in ITER, the neutron generator with neutron emission rate of 1011 s-1 or stronger is required to obtain high accuracy.

Nishitani, Takeo; Ishikawa, Masao; Kondoh, Takashi; Kusama, Yoshinori; Asai, Keisuke; Sasao, Mmamiko

2008-03-01

219

Absolute Configuration of a Rare Sesquiterpene: (+)-3-Ishwarone.  

PubMed

To determine the absolute configuration of 3-ishwarone, the experimental electronic circular dichroism (ECD), electronic dissymmetry factor (EDF), optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and vibrational dissymmetry factor (VDF) spectra of (+)-3-ishwarone are analyzed with the corresponding density functional theoretical predictions for different diastereomers. ECD and ORD spectra by themselves could not facilitate the determination of the absolute configuration of this molecule. However, the magnitude of the experimental EDF of (+)-3-ishwarone is found to match better with that predicted for the (1R,2S,4S,5R,9R,11R) diastereomer. The analyses of similarity measures between experimental and predicted spectra for VCD and VDF clearly suggested that the absolute configuration of (+)-3-ishwarone is (1R,2S,4S,5R,9R,11R). PMID:25051336

Junior, Fernando M S; Covington, Cody L; de Amorim, Mauro B; Velozo, Leosvaldo S M; Kaplan, Maria A C; Polavarapu, Prasad L

2014-07-22

220

Method and apparatus for two-dimensional absolute optical encoding  

NASA Technical Reports Server (NTRS)

This invention presents a two-dimensional absolute optical encoder and a method for determining position of an object in accordance with information from the encoder. The encoder of the present invention comprises a scale having a pattern being predetermined to indicate an absolute location on the scale, means for illuminating the scale, means for forming an image of the pattern; and detector means for outputting signals derived from the portion of the image of the pattern which lies within a field of view of the detector means, the field of view defining an image reference coordinate system, and analyzing means, receiving the signals from the detector means, for determining the absolute location of the object. There are two types of scale patterns presented in this invention: grid type and starfield type.

Leviton, Douglas B. (Inventor)

2004-01-01

221

Downhole dynamic sealing under differential and absolute pressure conditions  

SciTech Connect

The move towards higher production pressures and temperatures means that seal design for downhole usage may become a limiting factor for the exploitation of future wells. To determine factors associated with seal behavior under severe (HP/HT) conditions, a dynamic seal test facility has been built to simulate downhole conditions up to 15,000 psi and 250 C. A number of novel seal designs have been developed and tested for HP/HT service in downhole completions using this test facility. An important aspect of test procedure is whether the test is performed under absolute or differential pressure conditions. Previous work has emphasized absolute pressure conditions. This paper compares absolute and differential conditions and investigates which of these represents the more severe case.

Shepherd, R.; Stevenson, A. [Materials Engineering Research Lab. Ltd., Hertford (United Kingdom); Abrams, P.I. [Exxon Production Research Co., Houston, TX (United States)

1997-08-01

222

System and method for calibrating a rotary absolute position sensor  

NASA Technical Reports Server (NTRS)

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.

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

2012-01-01

223

Absolute and convective instability of a liquid jet  

NASA Astrophysics Data System (ADS)

Experiments on the absolute and convective instability of a liquid jet in microgravity were conducted at the NASA Lewis Research Center 2.2 second Drop Tower. A total of ten drop tests were performed with glycerin, and nineteen drop tests were performed with Dow Corning 200 series 1000 cSt silicone oil. An absolutely unstable liquid jet was photographed for the first time. Convective instability was characterized by disturbances that grew spatially in amplitude while being convected downstream, while absolute instability was characterized by disturbances that grew rapidly in both space and time, as predicted by the theory. The transitional Reynolds and Weber numbers were also identified and compared with the theoretical prediction.

Vihinen, I.; Lin, S. P.; Chen, J. N.

1996-11-01

224

Instruments for measuring radiant thermal fluxes  

NASA Technical Reports Server (NTRS)

An absolute two-sided radiometer, designed on the principle of replacing absorbed radiant energy with electrical energy, is described. The sensitive element of the detector is a thermoelectric transducer of thermal flux. The fabrication technology, methods of measurement, technical characteristics, and general operation of the instrument are presented.

Gerashenko, O. A.; Sazhina, S. A.

1974-01-01

225

Determining the Absolute Astrometric Error in Chandra Source Catalog Positions  

NASA Astrophysics Data System (ADS)

Although relative errors can readily be calculated, the absolute astrometric accuracy of the source positions in the Chandra Source Catalog (CSC), version 1.0, is a priori unknown. However, the cross-match with stellar objects from the Sloan Digital Sky Survey offers the opportunity to compare the apparent separations of the cross-matched pairs with the formally calculated errors. The analysis of these data allowed us to derive a value of 0farcs16 for the residual absolute astrometric error in CSC positions. This error will be added to the published position errors in the CSC from now on, starting with CSC, version 1.1.

Rots, Arnold H.; Budavári, Tamás

2011-01-01

226

DETERMINING THE ABSOLUTE ASTROMETRIC ERROR IN CHANDRA SOURCE CATALOG POSITIONS  

SciTech Connect

Although relative errors can readily be calculated, the absolute astrometric accuracy of the source positions in the Chandra Source Catalog (CSC), version 1.0, is a priori unknown. However, the cross-match with stellar objects from the Sloan Digital Sky Survey offers the opportunity to compare the apparent separations of the cross-matched pairs with the formally calculated errors. The analysis of these data allowed us to derive a value of 0.''16 for the residual absolute astrometric error in CSC positions. This error will be added to the published position errors in the CSC from now on, starting with CSC, version 1.1.

Rots, Arnold H. [Smithsonian Astrophysical Observatory, 60 Garden Street, MS 67, Cambridge, MA 02138 (United States); Budavari, Tamas, E-mail: arots@cfa.harvard.edu [Department of Physics and Astronomy, Johns Hopkins University, 3400 North Charles Street, Baltimore, MD 21218 (United States)

2011-01-15

227

Absolute instability in a traveling wave tube model  

NASA Astrophysics Data System (ADS)

A model is constructed to evaluate absolute instability which may lead to bandedge oscillations in a traveling wave tube. Under the assumptions (a) that all modes have forward group velocities, and (b) that the slow wave structure has a parabolic dispersion relation in the ?-k plane, the threshold coupling constant (Pierce's parameter C) is calculated for the onset of absolute instability. The effect of distributed resistive loss in the circuit is included. The axial wave number and the characteristic frequency of the oscillation at the onset are given.

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

1998-12-01

228

Absolute Stability Analysis of a Phase Plane Controlled Spacecraft  

NASA Technical Reports Server (NTRS)

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.

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

2010-01-01

229

Absolute measurement of optical surface profile with a Fizeau interferometer  

NASA Astrophysics Data System (ADS)

An optical surface profile is measured with a laser diode Fizeau interferometer using a method of absolute measurement. Wavefront aberration in the interferometer causes an undesirable phase distribution in the interference signal. To eliminate this phase distribution, the object surface is shifted in two directions orthogonal to each other and the difference wavefront of the surface profile of the object is obtained. An absolute surface profile is estimated by representing the object surface with a polynomial function and by solving the difference equations with least-squares method.

Sasaki, Osami; Watanabe, Akihiro; Choi, Samuel; Suzuki, Takamasa

2012-11-01

230

Absolute gain measurement by the image method under mismatched condition  

NASA Technical Reports Server (NTRS)

Purcell's image method for measuring the absolute gain of an antenna is particularly attractive for small test antennas. The method is simple to use and utilizes only one antenna with a reflecting plane to provide an image for the receiving antenna. However, the method provides accurate results only if the antenna is matched to its waveguide. In this paper, a waveguide junction analysis is developed to determine the gain of an antenna under mismatched condition. Absolute gain measurements for two standard gain horn antennas have been carried out. Experimental results agree closely with published data.

Lee, Richard Q.; Baddour, Maurice F.

1987-01-01

231

Non-Invasive Method of Determining Absolute Intracranial Pressure  

NASA Technical Reports Server (NTRS)

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.

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

2004-01-01

232

Absolute determination of the neutron source yield using melamine as a neutron detector  

NASA Astrophysics Data System (ADS)

A new approach to absolute determination of the neutron source yield is presented. It bases on the application of melamine (C3H6N6) to neutron detection combined with Monte Carlo simulations of neutron transport. Melamine has the ability to detect neutrons via 14N(n, p)14C reaction and subsequent determination of 14C content. A cross section for this reaction is relatively high for thermal neutrons (1.827 b) and much lower for fast neutrons. A concentration of 14C nuclei created in the irradiated sample of melamine can be reliably measured with the aid of the accelerator mass spectrometry (AMS). The mass of melamine sufficient for this analysis is only 10 mg. Neutron detection is supported by Monte Carlo simulations of neutron transport carried out with the use of MCNP-4C code. These simulations are aimed at computing the probability of 14C creation in the melamine sample per the source neutron. The result of AMS measurements together with results of MCNP calculations enable us to determine the number of neutrons emitted from the source during the irradiation of melamine. The proposed method was applied for determining the neutron emission from a commercial 252Cf neutron source which was independently calibrated. The measured neutron emission agreed with the certified one within uncertainty limits. The relative expanded uncertainty (k=2) of the absolute neutron source yield determination was estimated at 2.6%. Apart from calibration of radionuclide neutron sources the proposed procedure could facilitate absolute yield measurements for more complex sources. Potential applications of this methodology as it is further developed include diagnostics of inertial confinement fusion and plasma-focus experiments, calibration of neutron measurement systems at tokamaks and accelerator-based neutron sources as well as characterization of neutron fields generated in large particle detectors during collisions of hadron beams.

Ciechanowski, M.; Bolewski, A., Jr.; Kreft, A.

2015-01-01

233

The non-absoluteness of model existence in uncountable cardinals for L1,  

E-print Network

of Infinity. 1 #12;A main tool for absoluteness considerations is Shoenfields absoluteness Theorem (Theo- rem in form of the existence of an infinite in- discernible sequence, which by Shoenfield is absolute). Since also [2]) of having a model of size 1 (which is a 1 1 property and therefore absolute by Shoenfield

234

Calibration of the Absolute OH Content of Olivine  

Microsoft Academic Search

Paterson (1982) developed a method to determine the absolute OH concentration in minerals from the intensity of OH absorptions in the IR spectrum, that has been widely applied to geophysically important earth materials in nature and in laboratory experiments. Subsequent studies have shown the desirability of mineral-specific calibrations of the IR spectrum. Here we report a new calibration of the

G. R. Rossman; D. R. Bell; A. Maldener; D. Endisch; F. Rauch

2001-01-01

235

Chiral Silylation Reagents for the Determination of Absolute Configuration  

E-print Network

-(trifluoromethyl)phenylacetic acid1 (MTPA) and the cor- responding acid chlorides for this purpose has made a particularly important into the corresponding hydroxy methyl ester 2 (Figure 1), with the intention of using the MTPA methodology to compare MTPA to determine this sensitive alcohol's absolute stereochemistry. Similar difficulties in preparing

Weibel, Douglas B.

236

A wireless batch sealed absolute capacitive pressure sensor Orhan Akarb  

E-print Network

, and biomedical systems. Capacitive pressure sensors provide very high pressure sensitivity, low noise, and low the sealed cavity of the sensor and is connected to the pressure sensitive capacitor. Because the inductorA wireless batch sealed absolute capacitive pressure sensor Orhan Akarb , Tayfun Akina,b,* , Khalil

Akin, Tayfun

237

Determination of absolute photoionization cross sections of the phenyl radical  

E-print Network

via 193- or 248-nm dissociation of chlorobenzene. At 10.0 eV, the photoionization cross sections of chlorobenzene with a goal of determining its absolute PI cross sections using the known PI cross section wavelengths to create the radical and taking advantage of the multiple channels for chlorobenzene

Neumark, Daniel M.

238

Temporal Dynamics of Microbial Rhodopsin Fluorescence Reports Absolute Membrane Voltage  

E-print Network

trafficking and signal amplitude, time-domain encoding of absolute voltage could be applied to investigate-protein coupled receptors (3), and redox proteins (4). Bacteria, fungi, plants, and animal cells dynamically regulate voltage in the plasma membrane and in intracellular organelles. Resting potentials range from

Cohen, Adam E.

239

Fabricating the absolute fake: America in contemporary pop culture  

Microsoft Academic Search

Onze wereld wordt gedomineerd door de Amerikaanse popcultuur. Fabricating the Absolute Fake onderzoekt de dynamiek van Amerikanisering aan de hand van hedendaagse films, televisieprogramma's en popsterren die reflecteren op de vraag wat het betekent om Amerikaan in een mondiale popcultuur te zijn. Jaap Kooijman analyseert zowel Amerikaanse popcultuur (Oprah Winfrey, Ally McBeal, Michael Jackson) als Nederlandse populaire cultuur (Ali B.,

J. Kooijman

2008-01-01

240

Weighted Least Absolute Value state estimation using interior point methods  

Microsoft Academic Search

This paper addresses the application of interior point methods to the Weighted Least Absolute Value state estimation problem. Interior point methods are applied to the primal and dual formulations of the problem. The dual formulation involves solving least squares problems identical in structure to those used in conventional Weighted Least Squares state estimation. The dual formulation also provides an initial

H. Singh; F. L. Alvarado

1994-01-01

241

Absolute Calibration of a Large-diameter Light Source  

E-print Network

A method of absolute calibration for large aperture optical systems is presented, using the example of the Pierre Auger Observatory fluorescence detectors. A 2.5 m diameter light source illuminated by an ultra--violet light emitting diode is calibrated with an overall uncertainty of 2.1 % at a wavelength of 365 nm.

Brack, J T; Dorofeev, A; Gookin, B; Harton, J L; Petrov, Y; Rovero, A C

2013-01-01

242

Least absolute deviations estimation for the censored regression model  

Microsoft Academic Search

This paper proposes an alternative to maximum likelihood estimation of the parameters of the censored regression (or censored 'Tobit') model. The proposed estimator is a generalization of least absolute deviations estimation for the standard linear model, and, unlike estimation methods based on the assumption of normally distributed error terms, the estimator is consistent and asymptoti- cally normal for a wide

James L. Powell

1984-01-01

243

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....

244

Images of absolute retardance LDn, using the rotating polariser method  

E-print Network

Images of absolute retardance L·Dn, using the rotating polariser method M. A. GEDAY, W. KAMINSKY, J. Crystallogr. 13, 217), allow one to determine jsin dj, d ¼ 2pLDn/l, Dn ¼ double refraction, L ¼ light path

Kaminsky, Werner

245

Relative versus Absolute Stimulus Control in the Temporal Bisection Task  

ERIC Educational Resources Information Center

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,…

de Carvalho, Marilia Pinhiero; Machado, Armando

2012-01-01

246

Absolute calibration of Landsat instruments using the moon.  

USGS Publications Warehouse

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

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

1985-01-01

247

48-bit absolute internet and Ethernet host numbers  

Microsoft Academic Search

Xerox internets and Ethernet local computer networks use 48-bit absolute host numbers. This is a radical departure from practices currently in use in internetwork systems and local networks. This paper describes how the host numbering scheme was designed in the context of an overall internetwork and distributed systems architecture.

Yogen K. Dalal; Robert S. Printis

1981-01-01

248

Applications of absolute surface metrology by transverse shifting  

NASA Astrophysics Data System (ADS)

A novel and very simple technique has been developed for extracting absolute phase maps from laboratory Fizeau interferometers, and that technique is generalized here to applications in interferometry and adaptive optics. In the original implementation, the phase maps considered were those produced by an interferometer measuring the surface of a high-precision flat mirror. The phase or surface shape measured in such a configuration is known only with respect to the phase map of the interferometer's transmission flat, and so contains substantial errors when precise surfaces are being tested. By making two additional measurements with small lateral shifts of the surface under test, and differencing these, maps of absolute phase differences between neighboring points on the test surface can be made. From these, standard wavefront reconstruction can recover an absolute phase map. Examples of the technique are considered here, including a novel diagnostic of common-path errors in adaptive optics systems. For an architecture in which the common path and the wavefront-sensor path can be adjusted in relative shear, it is possible to apply the requisite transverse shifts and so derive an absolute phase map isolating embedded portions of the system optics.

Bloemhof, E. E.

2012-07-01

249

Europe's Other Poverty Measures: Absolute Thresholds Underlying Social Assistance  

ERIC Educational Resources Information Center

The first thing many learn about international poverty measurement is that European nations apply a "relative" poverty threshold and that they also do a better job of reducing poverty. Unlike the European model, the "absolute" U.S. poverty threshold does not increase in real value when the nation's standard of living rises, even though it is…

Bavier, Richard

2009-01-01

250

Less conservative absolute stability criteria using Integral Quadratic Constraints  

Microsoft Academic Search

Lur'e systems, that are described by the feedback interconnection of a linear time invariant system and a nonlinear system, form an important class of nonlinear systems arising in many modern applications. A number of absolute stability criteria are available where the stability is guaranteed with the nonlinearity restricted to a pre-specified set. Most of these criteria provide sufficient conditions for

Donatello Materassi; Murti V. Salapaka

2009-01-01

251

Measurements of absolute single differential cross section (SDCS)  

E-print Network

Measurements of absolute single differential cross section (SDCS) [Left] and percentage energy res and a resistive anode encoder are presented. A four­element lens mounted at the entrance of the analyser, provides using ion­optics program SIMION6.0 in­ dicates improved focusing properties for this off­ center

Zouros, Theo

252

New ultrahigh-sensitivity absolute, linear, and rotary encoders  

Microsoft Academic Search

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 reliability, 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

Douglas B. Leviton

1998-01-01

253

Urey: to measure the absolute age of Mars  

NASA Technical Reports Server (NTRS)

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.

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

254

Absolute detector quantum-efficiency measurements using correlated photons  

E-print Network

and Technology (NIST). We use pairs of correlated photons to produce spatial maps of the absolute efficiency of parametric down-conversion, which produces optical photons in pairs within a nonlinear crystal. Within the crystal, photons from a pump laser beam, in effect "decay" into pairs of photons under the restrictions

Migdall, Alan

255

Calculating Effective Absolute Permeability in Sandstone\\/Shale Sequences  

Microsoft Academic Search

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

Clayton Deutsch

1989-01-01

256

Ab initio calculation of hydrostatic absolute deformation potential of semiconductors  

E-print Network

on the wavefunction characters of the energy levels.3 It is now well accepted that the difference of the volume. ii The kinetic energy- induced band broadening. When the volume decreases, the bandwidth increasesAb initio calculation of hydrostatic absolute deformation potential of semiconductors Yong-Hua Li

Gong, Xingao

257

Absolute calibration of fusion gamma ray detector on TFTR  

NASA Astrophysics Data System (ADS)

An in situ measurement of the absolute detection efficiency of the fusion gamma ray detector on TFTR has been completed. The efficiency was determined by measuring the yield of the 4.44 MeV gamma ray from a plutonium-berrylium source situated within the vacuum vessel. The absolute detection efficiency at 4.44 MeV is extended to higher energies using the known energy dependence of the gamma ray attenuation coefficients in the vessel port cover, the detector neutron moderator, and the scintillator. The absolute detection efficiency (full energy peak detected gamma rays per source gamma ray) varies from 8.6E-9 at 4.44 MeV to 1.1E-8 at 17 MeV and is insensitive at the few percent level to relatively large variations in the radial profile of the gamma ray source distribution in the plasma. The absolute detection efficiency is used to determine the total d-3He reaction rate during recent deuterium neutral beam heated 3He plasmas on TFTR.

Medley, S. S.; Roquemore, A. L.; Cecil, F. E.

1992-10-01

258

Urey: to measure the absolute age of mars  

Microsoft Academic Search

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. Thus, Mars will join the Earth and the Moon as

James Randolph; Jeffrey Plescia; Yoseph Bar-Cohen; Paul Bartlett; Donald Bickler; Roger Carlson; G. Carr; Michael Fong; Henrik Gronroos; P. J. Guske; Mark Herring; Hamid Javadi; David W. Johnson; Timothy Larson; K. Malaviarachchi; S. Sherrit; S. Stride; A. Trebi-Ollenmu; R. Warwick

2003-01-01

259

Series that Converge Absolutely but Don't Converge  

ERIC Educational Resources Information Center

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.

Kantrowitz, Robert; Schramm, Michael

2012-01-01

260

Handheld Reflective Foil Emissometer with 0.007 Absolute Accuracy at 0.05  

NASA Astrophysics Data System (ADS)

The development and performance of a handheld emissometer for the measurement of the emissivity of highly reflective metallic foils used for the insulation of domestic and commercial buildings are described. Reflective roofing insulation based on a thin coating of metal on a more robust substrate is very widely used in hotter climates to reduce the radiant heat transfer between the ceiling and roof in commercial and residential buildings. The required normal emissivity of these foils is generally below 0.05, so stray reflected ambient infrared radiation (IR) makes traditional reflectance-based measurements of emissivity very difficult to achieve with the required accuracy. Many manufacturers apply additional coatings onto the metallic foil to reduce visible glare during installation on a roof, and to provide protection to the thin reflective layer; however, this layer can also substantially increase the IR emissivity. The system as developed at the National Measurement Institute, Australia (NMIA) is based on the principle of measurement of the modulation in thermal infrared radiation, as the sample is thermally modulated by hot and cold air streams. A commercial infrared to band radiation thermometer with a highly specialized stray and reflected radiation shroud attachment is used as the detector system, allowing for convenient handheld field measurements. The performance and accuracy of the system have been compared with NMIA's reference emissometer systems for a number of typical material samples, demonstrating its capability to measure the absolute thermal emissivity of these very highly reflective foils with an uncertainty of better than.

van der Ham, E. W. M.; Ballico, M. J.

2014-07-01

261

GNSS Absolute Antenna Calibration at the National Geodetic Survey  

NASA Astrophysics Data System (ADS)

Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna models and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these models into analysis software. To help meet the needs of the high-precision GNSS community, the National Geodetic Survey (NGS) now operates an absolute antenna calibration facility. Located in Corbin, Virginia, this facility uses field measurements and actual GNSS satellite signals to quantitatively determine the carrier phase advance/delay introduced by the antenna element. The NGS facility was built to serve traditional NGS constituents such as the surveying and geodesy communities, however calibration services are open and available to all GNSS users as the calibration schedule permits. All phase center patterns computed by this facility will be publicly available and disseminated in both the ANTEX and NGS formats. We describe the NGS calibration facility, and discuss the observation models and strategy currently used to generate NGS absolute calibrations. We demonstrate that NGS absolute phase center variation (PCV) patterns are consistent with published values determined by other absolute antenna calibration facilities, and compare absolute calibrations to the traditional NGS relative calibrations.

Mader, G. L.; Bilich, A. L.; Geoghegan, C.

2011-12-01

262

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

SciTech Connect

The first absolute wind velocities above the cloud-tops were obtained during four planetary phases spanning 82 percent of a synodic period. Bean-integrated Doppler displacements in the non-thermal emission core of (12)C(16)O2 10.33 microns R(8) (obtained at sub-Doppler resolution), 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 +/- 0.1 MHz, allowed S/N-limited line of sight velocity resolution at the 1 m/s level. The spectrometer's diffraction-limited beam and 1-2 arc-second seeing, provided the spatial resolution necessary for circulation model discrimination. Qualitative analysis of beam-integrated winds definitively established a dominant subsolar-antisolar circulation in the lower thermosphere. A retrograde zonal component was also suggested. Beam-integrated winds were modelled with a 100 x 100 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. Detection of a significant zonal component indicates upper thermospheric super-rotation may be coupled to, hence pumped by, cloud level super-rotation. Early heterodyne mesospheric wind measurements were re-examined based on laser stability test results.

Goldstein, J.J.

1989-01-01

263

Thermal conductivity surface for mixtures of methane and ethane  

SciTech Connect

A correlation is presented for the extensive series of thermal conductivity measurements of binary methane-ethane mixtures. The composition dependences of the thermal conductivity in the dilute-gas region, dense-gas and liquid region, and critical region are discussed. The average absolute percentage deviation of the thermal conductivity surface as a function of temperature, density, and composition, from the experimental data, is 1.60%.

Friend, D.G.; Roder, H.M.

1987-01-01

264

On the technique of absolutization of diffuse scattering intensity measurements based on thermal diffuse scattering measurements  

Microsoft Academic Search

Features of microdefect (MD) formation in GaAs(Si) single crystals grown by horizontally oriented crystallization were studied\\u000a by X-ray diffuse scattering (XRDS). Measurements were performed at room temperature (?298 K) and near the liquid nitrogen\\u000a evaporation temperature (?85 K) using an open-flow cooling nitrogen cryostat. A practical technique for measuring XRDS using\\u000a a triple-axis X-ray diffractometer was developed and applied to

V. T. Bublik; K. D. Shcherbachev; M. I. Voronova; E. V. Zhevnerov

2010-01-01

265

A new absolute magnitude calibration for red clump stars  

NASA Astrophysics Data System (ADS)

We present an MV absolute magnitude calibration including the B-V colour and [Fe/H] metallicity for the red clump stars in the globular and open clusters with a wide range of metallicities: MV=0.627(±0.104)(B-V)0+0.046(±0.043)[Fe/H]+0.262(±0.111). The calibration equation is valid in the ranges 0.42<(B-V)0<1.20 mag, -1.55<[Fe/H]<+0.40 dex and 0.43absolute magnitudes for the clump giants can be estimated from the calibration formula.

Bilir, S.; Ak, T.; Ak, S.; Yontan, T.; Bostanc?, Z. F.

2013-10-01

266

First results from Swarm's Absolute Scalar Magnetometers burst mode  

NASA Astrophysics Data System (ADS)

Swarm's Absolute Scalar Magnetometers (ASM) provide absolute scalar measurements of the magnetic field with high accuracy and stability on the three satellites of the mission. These ASMs nominally run at 1 Hz. But they can also run at 250 Hz frequency using a so-called "burst" mode. This possibility is to be taken advantage of during commissioning (on-going, at time of writing this abstract). In particular, the burst mode is to be run simultaneously on all three satellites over several days. Although these burst mode sessions were initially driven by the engineering need to explore the high frequency spectral content of the signal measured by the ASMs, they can also be used to look for meaningful high frequency geomagnetic signal. In this poster, the data acquired (by the time of the meeting) will be presented and their main characteristics discussed.

Hulot, Gauthier; Vigneron, Pierre; Brocco, Laura; Crespo-Grau, Raul; Chulliat, Arnaud; Léger, Jean-Michel; Jager, Thomas; Bertrand, François; Boness, Axel; Fratter, Isabelle

2014-05-01

267

Stellar Absolute Magnitudes via the Statistical Parallax Method  

E-print Network

I review statistical parallax absolute magnitude determinations which employ data from the HIPPARCOS satellite for RR Lyrae and Cepheid variables, and for several other stellar classes. Five groups have studied the RR Lyrae stars, and the results are reassuringly consistent: M_V(RR) = 0.77 +- 0.13 mag at [Fe/H] = -1.6 dex. Extensive Monte Carlo simulations showed that systematic errors are small (~0.03 mag or less), and corrections for them were applied in the above result. The RR Lyrae result is thus very secure. A statistical parallax study of Cepheids found the Period--Luminosity zero-point to be considerably fainter than studies based on HIPPARCOS trigonometric parallaxes. The distance modulus of the Large Magellanic Cloud derived from this zero-point is in excellent agreement with that derived using the RR Lyrae result. I discuss why the statistical parallax absolute magnitude calibrations differ with some other RR Lyrae and Cepheid calibrations.

Andrew C. Layden

1998-10-28

268

In-flight absolute radiometric calibration of the thematic mapper  

NASA Technical Reports Server (NTRS)

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.

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

269

Absolute calibration of Analog Detectors using Stimulated Parametric Down Conversion  

E-print Network

Spontaneous parametric down conversion has been largely exploited as a tool for absolute calibration of photon counting detectors, photomultiplier tubes or avalanche photodiodes working in Geiger regime. In this work we investigate the extension of this technique from very low photon flux of photon counting regime to the absolute calibration of analog photodetectors at higher photon flux. Moving toward higher photon rate, i.e. at high gain regime, with the spontaneous parametric down conversion shows intrinsic limitations of the method, while the stimulated parametric down conversion process, where a seed beam properly injected into the crystal in order to increase the photon generation rate in the conjugate arm, allows us to work around this problem. A preliminary uncertainty budget is discussed.

G. Brida; M. Chekhova; M. Genovese; M. L. Rastello; I. Ruo-Berchera

2008-02-04

270

Absolute calibration of Analog Detectors using Stimulated Parametric Down Conversion  

E-print Network

Spontaneous parametric down conversion has been largely exploited as a tool for absolute calibration of photon counting detectors, photomultiplier tubes or avalanche photodiodes working in Geiger regime. In this work we investigate the extension of this technique from very low photon flux of photon counting regime to the absolute calibration of analog photodetectors at higher photon flux. Moving toward higher photon rate, i.e. at high gain regime, with the spontaneous parametric down conversion shows intrinsic limitations of the method, while the stimulated parametric down conversion process, where a seed beam properly injected into the crystal in order to increase the photon generation rate in the conjugate arm, allows us to work around this problem. A preliminary uncertainty budget is discussed.

Brida, G; Genovèse, M; Rastello, M L; Ruo-Berchera, I

2008-01-01

271

Absolute calibration of analog detectors using stimulated parametric down conversion  

NASA Astrophysics Data System (ADS)

Spontaneous parametric down conversion has been largely exploited as a tool for absolute calibration of photon counting detectors, photomultiplier tubes or avalanche photodiodes working in Geiger regime. In this work we investigate the extension of this technique from very low photon flux of photon counting regime to the absolute calibration of analog photodetectors at higher photon flux. Moving toward higher photon rate, i.e. at high gain regime, with the spontaneous parametric down conversion shows intrinsic limitations of the method, while the stimulated parametric down conversion process, where a seed beam properly injected into the crystal in order to increase the photon generation rate in the conjugate arm, allows us to work around this problem. A preliminary uncertainty budget is discussed.

Brida, G.; Chekhova, M.; Genovese, M.; Rastello, M.-L.; Ruo-Berchera, I.

2009-01-01

272

Stability of absolute depth reconstruction from deflectometric measurement data  

NASA Astrophysics Data System (ADS)

Until recently, the problem of reconstructing specular surface shapes from deflectometric registration data was considered inherently ambiguous, and thus requiring additional information in order to uniquely determine the absolute surface position. In 2013, Liu, Hartley and Salzmann suggested a solution to the reconstruction problem which employed the first-order derivatives of the registration data in order to recover the absolute depth of the surface along each camera ray. In this work, we demonstrate an alternative derivation of equivalent results, leading to more computationally efficient and tractable expressions. Re-formulated in terms of normal vector field, our results provide a natural regularization that together with or without external regularization data could be easily used within the existing reconstruction algorithms. We further elaborate on the stability and the uniqueness of the solution. In particular, we find conditions when a shape cannot be uniquely recovered and identify two equations that characterize the families of such shapes.

Pak, Alexey

2014-07-01

273

Absolute scale-based imaging position encoder with submicron accuracy  

NASA Astrophysics Data System (ADS)

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.

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

2013-04-01

274

Optical absolute difference measurement for gray-scale image matching  

NASA Astrophysics Data System (ADS)

In this paper absolute difference measurement (ADM) is proposed for optical gray-scale image recognition. ADM measures the similarity between different gray-scale images and the value of measurement reflects the similarity linearly. Using optical correlation and a novel cycle- encoding method the processing of gray-scale image matching based on absolute difference measurement can be realized simply. This new method can be used in coherent correlators or incoherent correlators. In this paper a compact hybrid image recognition unit based on an incoherent correlator is constructed. The system has good fault-tolerance ability for rotation distortion, Gauss noise disturbance or information losing. In the experiments some pictures of military objects are processed. The recognition speed is 12 frames per second and the accuracy of recognition is more than 95 percent.

Cheng, Gang; Jin, Guofan; Wu, Minxian; Liu, Haisong; He, Qingsheng

1998-08-01

275

The Euler Equation and¶Absolute Minimizers of L? Functionals  

Microsoft Academic Search

:   The Aronsson-Euler equation for the functional\\u000a \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a on W\\u000a \\u000a \\u000a \\u000a g\\u000a \\u000a \\u000a \\u000a 1, ?(?, ?\\u000a \\u000a m\\u000a \\u000a , i.e., W\\u000a \\u000a 1, ? with boundary data g, is \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a \\u000a This equation has been derived for smooth absolute minimizers, i.e., a function which minimizes F on every subdomain. We prove in this paper that for m=1, n? 1, or n=1, m? 1 an absolute minimizer of

E. N. Barron; R. R. Jensen; C. Y. Wang

2001-01-01

276

Oblique-incidence sounder measurements with absolute propagation delay timing  

SciTech Connect

Timing from the Global Position Satellite (GPS) system has been applied to HF oblique incidence sounder measurements to produce ionograms whose propagation delay time scale is absolutely calibrated. Such a calibration is useful for interpreting ionograms in terms of the electron density true-height profile for the ionosphere responsible for the propagation. Use of the time variations in the shape of the electron density profile, in conjunction with an HF propagation model, is expected to provide better near-term (1-24 hour) HF propagation forecasts than are available from current updating systems, which use only the MUF. Such a capability may provide the basis for HF frequency management techniques which are more efficient than current methods. Absolute timing and other techniques applicable to automatic extraction of the electron-density profile from an ionogram will be discussed.

Daehler, M.

1990-05-03

277

Absolute calibration of TFTR helium proportional counters (abstract)a)  

NASA Astrophysics Data System (ADS)

The TFTR helium proportional counters are located in the central five (5) channels of the TFTR multichannel neutron collimator. These detectors were absolutely calibrated using a 14 MeV neutron generator positioned at the horizontal midplane of the TFTR vacuum vessel. The neutron generator position was scanned in centimeter steps to determine the collimator aperture width to 14 MeV neutrons and the absolute sensitivity of each channel. Neutron profiles were measured for TFTR plasmas with time resolution between 5 and 50 ms depending upon count rates. The He detectors were used to measure the burnup of 1 MeV tritons in deuterium plasmas, the transport of tritium in trace tritium experiments, and the residual tritium levels in plasmas following 50:50 DT experiments.

Strachan, J. D.; Barnes, Cris W.; Diesso, M.; Jassby, D.; Johnson, L.; Loughlin, M.; McCauley, S.; Munsat, T.; Roquemore, A. L.

1995-01-01

278

Assignment of Absolute Configuration to SCH 351448 via Total Synthesis?  

PubMed Central

The synthesis and absolute configuration of SCH 351448, an interesting ionophoric natural product, are reported herein. Mukaiyama aldol-Prins and segment-coupling Prins reactions were employed to construct the constituent tetrahydropyrans of SCH 351448. Efforts to assemble the C2-symmetric core of the natural product by a templated olefin metathesis strategy are described, however, a stepwise fragment assembly was ultimately utilized to complete the target molecule. PMID:18543942

Cheung, Lael L.; Marumoto, Shinji; Anderson, Christopher D.

2008-01-01

279

Absolute Total np and pp Cross Section Determinations  

E-print Network

Absolute total cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses of NN scattering data. These cross sections are compared with most recent ENDF/B and JENDL data files, and the Nijmegen partial-wave analysis. Systematic deviations from the ENDF/B and JENDL evaluations are found to exist in the low-energy region.

Arndt, R A; Laptev, A B; Strakovsky, I I; Workman, R L

2008-01-01

280

Absolute Total np and pp Cross Section Determinations  

E-print Network

Absolute total cross sections for np and pp scattering below 1000 MeV are determined based on partial-wave analyses of NN scattering data. These cross sections are compared with most recent ENDF/B and JENDL data files, and the Nijmegen partial-wave analysis. Systematic deviations from the ENDF/B and JENDL evaluations are found to exist in the low-energy region.

R. A. Arndt; W. J. Briscoe; A. B. Laptev; I. I. Strakovsky; R. L. Workman

2009-01-05

281

Absolute configuration of hydroxycitric acid produced by microorganisms.  

PubMed

Optical resolution for (2S,3R) and (2R,3S)-hydroxycitric acid (HCA) enantiomers was developed using chiral column chromatography. HCA from Bacillus megaterium G45C and Streptomyces sp. U121, newly isolated in our previous study, was analyzed to determine the absolute configuration. These results indicate that both strains generate optically pure (2S,3R)-hibiscus type HCA enantiomer. PMID:16926511

Hida, Hiroyuki; Yamada, Takashi; Yamada, Yasuhiro

2006-08-01

282

Measuring absolute spectral radiance using an Erbium Doped Fibre Amplifier  

E-print Network

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.

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

2012-10-22

283

Measuring absolute spectral radiance using an Erbium Doped Fibre Amplifier  

E-print Network

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.

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

2012-01-01

284

An absolute high performance, self calibrating optical rotary positioning system  

Microsoft Academic Search

The next generation high performance Absolute Rotary Position System with self-calibration capability, incorporating a fast Digital Signal Processing (DSP) algorithm with digital servo control capability, is presented. Critical encoder calibration parameters and their effects on accuracy are discussed with respect to a novel multi-tier Sine\\/Cosine (S\\/C) read-out approach. This approach consists of all S\\/C tracks in place of digital tracks

Asad M. Madni; Mike Jumper; Tim Malcolm

2001-01-01

285

Absolute continuity of hyperbolic invariant measures for endomorphisms  

NASA Astrophysics Data System (ADS)

We prove that, for a C2 non-invertible but non-degenerate map f on a compact Riemannian manifold without boundary, a hyperbolic invariant measure ? is absolutely continuous with respect to the Lebesgue measure on the manifold if, under a condition on the Jacobian of the map, the measure satisfies two entropy formulae for positive exponents [13] and negative exponents [7], respectively. This implies that the entropy production e?(f) = 0 if and only if ? Lt Leb.

Liu, Pei-Dong; Shu, Lin

2011-05-01

286

Synthesis and absolute configuration of hormone alpha1.  

PubMed

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

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

287

Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis  

SciTech Connect

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.

Sannibale, F.; /LBL, Berkeley; Stupakov, G.V.; /SLAC; Zolotorev, M.S.; /LBL, Berkeley; Filippetto, D.; /INFN, Rome; Jagerhofer, L.; /Vienna, Tech. U.

2009-12-09

288

LHD plasma emission measurements by means of absolute XUV photodiodes  

Microsoft Academic Search

The paper describes the measurements of the LHD plasma total radiation. The 16-channel pinhole type array was based on Absolute XUV photodiodes (AXUVD) (www.ird-inc.com). The detectors have an extended range of photon energies 20 eV \\\\x81E10 keV, for which sensitivity is high and approximately constant (0.22-0.27 A\\/W). AXUV diodes are also fast, miniature, easy to use and relatively inexpensive. The

Artem Kostrioukov; Byron Peterson; Shigeru Sudo; Masaki Osakabe; Tetuo Ozaki; Katsumi Ida

2001-01-01

289

Global relative and absolute quantitation in microbial proteomics.  

PubMed

Proteomic studies are designed to yield either qualitative information on proteins (identification, distribution, posttranslational modifications, interactions, structure and function) or quantitative information (abundance, distribution within different localizations, temporal changes in abundance due to synthesis and degradation or both). To this end these studies can draw upon a wide range of qualitative and quantitative gel-based and gel-free techniques. This review summarizes current proteomic workflows for global relative or absolute protein quantitation and their application in microbial physiology. PMID:22445110

Otto, Andreas; Bernhardt, Jörg; Hecker, Michael; Becher, Dörte

2012-06-01

290

Absolute Thermoelectric Power of Pb-Sn Alloys  

NASA Astrophysics Data System (ADS)

In this work, absolute thermoelectric power (ATP) of Pb, Sn, Pb-20 wt.% Sn, Pb-40 wt.% Sn, Pb-60 wt.% Sn, Pb-80 wt.% Sn are measured. Measurements are performed in a temperature gradient furnace from 20°C to 500°C, for both solid and liquid states. Temperatures are measured with T-type copper-constantan thermocouples, while voltage signal between copper electrodes of those thermocouples is recorded in order to calculate ATP of the sample metal.

Kaldre, I.; Fautrelle, Y.; Etay, J.; Bojarevics, A.; Buligins, L.

291

Absolute Rayleigh Intensity and Uniform Optical Conductivity in Carbon Nanotubes  

Microsoft Academic Search

We used a novel on-chip Rayleigh imaging technique to measure the absolute intensity of Rayleigh scattering of single-walled carbon nanotubes. The spatial distribution of the radiation scattered by the nanotubes is determined by their shape, but the intensity and spectrum of the scattered radiation are determined by exciton dynamics, quantum-dot-like optical resonances and other intrinsic properties. Moreover, the nanotubes display

Lihong Herman; Daniel Joh; Jesse Kinder; Sang-Yong Ju; Michael Segal; Jeffreys Johnson; Garnet Chan; Jiwoong Park

2011-01-01

292

Absolute GNSS Antenna Calibration at the National Geodetic Survey  

NASA Astrophysics Data System (ADS)

Geodetic GNSS applications routinely demand millimeter precision and extremely high levels of accuracy. To achieve these accuracies, measurement and instrument biases at the centimeter to millimeter level must be understood. One of these biases is the antenna phase center, the apparent point of signal reception for a GNSS antenna. It has been well established that phase center patterns differ between antenna models and manufacturers; additional research suggests that the addition of a radome or the choice of antenna mount can significantly alter those a priori phase center patterns. For the more demanding GNSS positioning applications and especially in cases of mixed-antenna networks, it is all the more important to know antenna phase center variations as a function of both elevation and azimuth in the antenna reference frame and incorporate these models into analysis software. To help meet the needs of the high-precision GNSS community, the National Geodetic Survey (NGS) now operates an absolute antenna calibration facility. Located in Corbin, Virginia, this facility uses field measurements and actual GNSS satellite signals to quantitatively determine the carrier phase advance/delay introduced by the antenna element. The NGS facility was built to serve traditional NGS constituents such as the surveying and geodesy communities, however calibration services are open and available to all GNSS users as the calibration schedule permits. All phase center patterns computed by this facility will be publicly available and disseminated in both the ANTEX and NGS formats. We describe the NGS calibration facility, and discuss the observation models and strategy currently used to generate NGS absolute calibrations. We demonstrate that NGS absolute phase center variation (PCV) patterns are consistent with published values determined by other absolute antenna calibration facilities, and outline future planned refinements to the system.

Mader, G.; Bilich, A.; Geoghegan, C.

2012-04-01

293

THE ABSOLUTE MAGNITUDES OF TYPE Ia SUPERNOVAE IN THE ULTRAVIOLET  

SciTech Connect

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.

Brown, Peter J.; Roming, Peter W. A.; Ciardullo, Robin; Gronwall, Caryl; Hoversten, Erik A.; Pritchard, Tyler [Department of Astronomy and Astrophysics, Pennsylvania State University, University Park, PA 16802 (United States); Milne, Peter [Steward Observatory, University of Arizona, Tucson, AZ 85719 (United States); Bufano, Filomena; Mazzali, Paolo [INAF-Osservatorio Astronomico di Padova, Vicolo dell'Osservatorio 5, I-35122 Padova (Italy); Elias-Rosa, Nancy [Spitzer Science Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Filippenko, Alexei V.; Li Weidong [Department of Astronomy, University of California, Berkeley, CA 94720-3411 (United States); Foley, Ryan J.; Hicken, Malcolm; Kirshner, Robert P. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Gehrels, Neil; Holland, Stephen T.; Immler, Stefan [NASA Goddard Space Flight Center, Greenbelt, MD 20771 (United States); Phillips, Mark M. [Las Campanas Observatory, Casilla 601, La Serena (Chile); Still, Martin, E-mail: pbrown@physics.utah.ed [Mullard Space Science Laboratory, Department of Space and Climate Physics, University College London, Holmbury St. Mary, Dorking, Surrey, RH5 6NT (United Kingdom)

2010-10-01

294

Absolute measurements of local chromophore concentrations using pulsed photoacoustic spectroscopy  

Microsoft Academic Search

Photoacoustic spectroscopy has the potential to make non-invasive, spatially resolved measurements of absolute chromophore concentrations. This has a wide range of possible applications, for example the mapping of endogenous chromophores such as oxy- (HbO2) and deoxyhaemoglobin (HHb) or externally administered contrast agents designed to target specific tissues or molecular processes. In this study we used near-infrared photoacoustic spectroscopy to determine

J. Laufer; C. Elwell; D. Delpy; P. Beard

2006-01-01

295

Absolute calibration and beam background of the Squid Polarimeter  

SciTech Connect

The problem of beam background in Squid Polarimetry is not without residual benefits. The authors may deliberately generate beam background by gently kicking the beam at the spin tune frequency. This signal may be used to accomplish a simple and accurate absolute calibration of the polarimeter. The authors present details of beam background calculations and their application to polarimeter calibration, and suggest a simple proof-of-principle accelerator experiment.

Blaskiewicz, M.M.; Cameron, P.R.; Shea, T.J. [and others

1996-12-31

296

Absolute intensity of radiation emitted by uranium plasmas  

NASA Technical Reports Server (NTRS)

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.

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

1975-01-01

297

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)

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.

McLeod, David M.; Ataide, Italani; McLeod, Roger D.

2006-03-01

298

Jasminum sambac flower absolutes from India and China--geographic variations.  

PubMed

Seven Jasminum sambac flower absolutes from different locations in the southern Indian state of Tamil Nadu were analyzed using GC and GC-MS. Focus was placed on 41 key ingredients to investigate geographic variations in this species. These seven absolutes were compared with an Indian bud absolute and commercially available J. sambac flower absolutes from India and China. All absolutes showed broad variations for the 10 main ingredients between 8% and 96%. In addition, the odor of Indian and Chinese J. sambac flower absolutes were assessed. PMID:22799098

Braun, Norbert A; Sim, Sherina

2012-05-01

299

Absolute cross sections for electron scattering from furan  

NASA Astrophysics Data System (ADS)

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.

Maljkovi?, J. B.; Blanco, F.; ?urík, R.; García, G.; Marinkovi?, B. P.; Milosavljevi?, A. R.

2012-08-01

300

Switching between visuomotor mappings: learning absolute mappings or relative shifts.  

PubMed

Adaptation to specific visuomotor mappings becomes faster when switching back and forth between them. What is learned when repeatedly switching between the visuomotor mappings: the absolute mappings or the relative shift between the mappings? To test this, we trained participants in a rapid pointing task using a unique color cue as context for each mapping between pointing location and visual feedback. After extensive training, participants adapted to a new mapping using a neutral contextual cue. For catch trials (a change in cue and no visual feedback) different adaptation performances are predicted depending on how the mappings are encoded. When encoding an absolute mapping for each cue, participants would fall back to the mapping associated with the cue irrespective of the state they are currently in. In contrast, when a shift in mapping is encoded for the cue, pointing performance will shift relative to the current mapping by an amount equal to the difference between the previously learned mappings. Results indicate that the contextual cues signal absolute visuomotor mappings rather than relative shifts between mappings. PMID:23447680

van Dam, Loes C J; Hawellek, David J; Ernst, Marc O

2013-01-01

301

Absolute gravity acceleration measurement in atomic sensor laboratories  

NASA Astrophysics Data System (ADS)

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.

de Angelis, M.; Greco, F.; Pistorio, A.; Poli, N.; Prevedelli, M.; Saccorotti, G.; Sorrentino, F.; Tino, G. M.

2012-03-01

302

Peripheral absolute threshold spectral sensitivity in retinitis pigmentosa.  

PubMed Central

Dark-adapted spectral sensitivities were measured in the peripheral retinas of 38 patients diagnosed as having typical retinitis pigmentosa (RP) and in 3 normal volunteers. The patients included those having autosomal dominant and autosomal recessive inheritance patterns. Results were analysed by comparisons with the CIE standard scotopic spectral visibility function and with Judd's modification of the photopic spectral visibility function, with consideration of contributions from changes in spectral transmission of preretinal media. The data show 3 general patterns. One group of patients had absolute threshold spectral sensitivities that were fit by Judd's photopic visibility curve. Absolute threshold spectral sensitivities for a second group of patients were fit by a normal scotopic spectral visibility curve. The third group of patients had absolute threshold spectral sensitivities that were fit by a combination of scotopic and photopic spectral visibility curves. The autosomal dominant and autosomal recessive modes of inheritance were represented in each group of patients. These data indicate that RP patients have normal rod and/or cone spectral sensitivities, and support the subclassification of patients described previously by Massof and Finkelstein. PMID:7459312

Massof, R W; Johnson, M A; Finkelstein, D

1981-01-01

303

A large aperture blackbody bath for calibration of thermal imagers  

NASA Astrophysics Data System (ADS)

Thermal imagers are becoming widely used instruments for noncontact absolute temperature measurements as opposed to previous practice when they were mostly used to measure temperature differences. To assure accurate and reliable absolute temperature measurements, a calibration procedure including evaluation of the thermal imager entire field of view (FOV) is needed. The challenge was to construct a large aperture blackbody, covering the complete FOV of the thermal imager and having better stability and non-uniformity than the thermal sensitivity of the imager. The blackbody calibration bath was designed on hypothesis analogous to the multi zone furnace, where the role of electrical heaters was superseded by electrically controlled valves. The experimental work showed that the designed system enables traceable calibration of thermal imagers in the temperature range from 10 to 70 °C with the expanded uncertainty of 0.2 °C, while further investigations are needed to cover ranges beyond that.

Miklavec, A.; Pušnik, I.; Batagelj, V.; Drnovšek, J.

2013-02-01

304

Laser interferometry method for absolute measurement of the acceleration of gravity  

NASA Technical Reports Server (NTRS)

Gravimeter permits more accurate and precise absolute measurement of g without reference to Potsdam values as absolute standards. Device is basically Michelson laser beam interferometer in which one arm is mass fitted with corner cube reflector.

Hudson, O. K.

1971-01-01

305

An application of Shoenfield's absoluteness theorem to the theory of uniform distribution  

E-print Network

An application of Shoenfield's absoluteness theorem to the theory of uniform distribution Martin uniformly distributed sequences. Supported by DFG grant Ko 490/7­1 #12; Shoenfield's absoluteness theorem of this theorem: One for logicians, using the technique of forcing and Shoenfield's absoluteness theorem for # 1 2

Goldstern, Martin

306

Absolute Earthquake Locations with Differential Data By William Menke and David Schaff  

E-print Network

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

Menke, William

307

A Special Application of Absolute Value Techniques in Authentic Problem Solving  

ERIC Educational Resources Information Center

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…

Stupel, Moshe

2013-01-01

308

Absolute Efficiency Calibration of a Beta-Gamma Detector  

SciTech Connect

Abstract- Identification and quantification of nuclear events such as the Fukushima reactor failure and nuclear explosions rely heavily on the accurate measurement of radioxenon releases. One radioxenon detection method depends on detecting beta-gamma coincident events paired with a stable xenon measurement to determine the concentration of a plume. Like all measurements, the beta-gamma method relies on knowing the detection efficiency for each isotope measured. Several methods are commonly used to characterize the detection efficiency for a beta-gamma detector. The most common method is using a NIST certified sealed source to determine the efficiency. A second method determines the detection efficiencies relative to an already characterized detector. Finally, a potentially more accurate method is to use the expected sample to perform an absolute efficiency calibration; in the case of a beta-gamma detector, this relies on radioxenon gas samples. The complication of the first method is it focuses only on the gamma detectors and does not offer a solution for determining the beta efficiency. The second method listed is not similarly constrained, however it relies on another detector to have a well-known efficiency calibration. The final method using actual radioxenon samples to make an absolute efficiency determination is the most desirable, but until recently it was not possible to produce all four isotopically pure radioxenon. The production, by University of Texas (UT), of isotopically pure radioxenon has allowed the beta-gamma detectors to be calibrated using the absolute efficiency method. The first four radioxenon isotope calibration will be discussed is this paper.

Cooper, Matthew W.; Ely, James H.; Haas, Derek A.; Hayes, James C.; McIntyre, Justin I.; Lidey, Lance S.; Schrom, Brian T.

2013-04-10

309

Morphology and Absolute Magnitudes of the SDSS DR7 QSOs  

NASA Astrophysics Data System (ADS)

The ESA mission Gaia will furnish a complete census of the Milky Way, delivering astrometrics, dynamics, and astrophysics information for 1 billion stars. Operating in all-sky repeated survey mode, Gaia will also provide measurements of extra-galactic objects. Among the later there will be at least 500,000 QSOs that will be used to build the reference frame upon which the several independent observations will be combined and interpreted. Not all the QSOs are equally suited to fulfill this role of fundamental, fiducial grid-points. Brightness, morphology, and variability define the astrometric error budget for each object. We made use of 3 morphological parameters based on the PSF sharpness, circularity and gaussianity, which enable us to distinguish the "real point-like" QSOs. These parameters are being explored on the spectroscopically certified QSOs of the SDSS DR7, to compare the performance against other morphology classification schemes, as well as to derive properties of the host galaxy. We present a new method, based on the Gaia quasar database, to derive absolute magnitudes, on the SDSS filters domain. The method can be extrapolated all over the optical window, including the Gaia filters. We discuss colors derived from SDSS apparent magnitudes and colors based on absolute magnitudes that we obtained tanking into account corrections for dust extinction, either intergalactic or from the QSO host, and for the Lyman ? forest. In the future we want to further discuss properties of the host galaxies, comparing for e.g. the obtained morphological classification with the color, the apparent and absolute magnitudes, and the redshift distributions.

Coelho, B.; Andrei, A. H.; Antón, S.

2014-10-01

310

Pharmacokinetics and absolute bioavailability of epristeride in healthy male subjects.  

PubMed

The objective of the current investigation was to describe the pharmacokinetics and absolute oral bioavailability of epristeride. Twelve healthy male subjects (mean (SD) age, 27 (6.2) years) received a single oral dose of 5 mg and an intravenous infusion of 4.5 mg over 30 min in a crossover fashion. Blood samples were obtained over 72h for the determination of epristeride plasma concentrations using a sensitive high-performance liquid chromatography assay. The lower limit of quantification was 5 ng mL-1. Pharmacokinetic analysis of the plasma concentration-time data was performed by both non-compartmental and compartmental methods. Absolute bioavailability was determined using dose-normalized AUC values following oral and intravenous administration. Epristeride plasma concentrations declined in a biexponential fashion with secondary peaks evident around 24 h in a majority of subjects following both routes of administration. Maximal plasma concentrations were typically achieved approximately 4 h after oral dosing. The mean apparent terminal elimination half-life estimates were similar following intravenous and oral administration and were 27.3 and 26.2 h, respectively. The mean plasma clearance and steady-state volume of distribution were 0.33 (0.09) mL min-1 kg-1 and 0.54 (0.17) L kg-1, respectively. The mean absolute bioavailability was 93% (95% CI: 84%, 104%). Following compartmental analysis of the intravenous data, the mean (SD) lambda 1 and lambda 2 half-life estimates were 2.74 (0.48) and 31.8 (19.5) h, respectively. The % AUC associated with the lambda 2 exponential phase was approximately 68%. This long half-life allows for once-daily dosing of epristeride. PMID:8983399

Benincosa, L J; Audet, P R; Lundberg, D; Zariffa, N; Jorkasky, D K

1996-04-01

311

The absolute radiometric calibration of Terra imaging sensors: MODIS, MISR, and ASTER  

NASA Astrophysics Data System (ADS)

The Terra spacecraft contains five Earth-observation instruments, three of which are multispectral imaging sensors that complement each other in spectral and spatial coverage. The Moderate Resolution Imaging Spectroradiometer (MODIS) has 36 channels ranging from 0.4-14.4 ?m, with spatial resolutions of 250, 500, and 1000 m. The Multi-angle Imaging SpectroRadiometer (MISR) uses individual imaging sensors to view the earth at nine discreet angles. Each radiometer has four channels in the visible and near infrared (VNIR), and the nadir-viewing camera has a spatial resolution of 275 m. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was designed with fourteen bands ranging from 0.5-11.6 ?m. It is the high-resolution sensor on Terra, with a spatial resolution of 15 m in the VNIR, and 30 m in the shortwave infrared (SWIR). This work describes the vicarious techniques used to perform the absolute radiometric calibration of MODIS, MISR, and ASTER in the solar-reflective region (0.4-2.5 ?m). It includes the reflectance-based approach, which uses ground-based personnel to make in situ measurements during the time of overpass. It also includes more recent results that were obtained using the University of Arizona's automated Radiometric Calibration Test Site (RadCaTS) at Railroad Valley, Nevada. In addition to the absolute radiometric calibration of Terra sensors, RadCaTS is used to perform the cross comparison of MODIS, MISR, and ASTER with Landsat 7 ETM+ and Landsat 8 OLI.

Czapla-Myers, Jeffrey; Thome, Kurtis; Anderson, Nikolaus; Biggar, Stuart

2014-10-01

312

SkyProbe, monitoring the absolute atmospheric transmission in the optical  

NASA Astrophysics Data System (ADS)

Mauna Kea is known for its pristine seeing conditions, but sky transparency can be an issue for science operations since 25% of the night are not photometric, mostly due to high-altitude cirrus. Since 2001, the original single-channel SkyProbe has gathered one exposure every minute during each observing night using a small CCD camera with a very wide field of view (35 sq. deg.) encompassing the region pointed by the telescope for science operations, and exposures long enough (40 seconds) to capture at least 100 stars of Hipparcos' Tychos catalog at high galactic latitudes (and up to 600 stars at low galactic latitudes). A key advantage of SkyProbe over direct thermal infrared imaging detection of clouds, is that it allows an accurate absolute measurement, within 5%, of the true atmospheric absorption by clouds affecting the data being gathered by the telescope's main science instrument. This system has proven crucial for decision making in the CFHT queued service observing (QSO), representing today 80% of the telescope time: science exposures taken in non-photometric conditions are automatically registered for being re-observed later on (at 1/10th of the original exposure time per pointing in the observed filters) to ensure a proper final absolute photometric calibration. The new dual color system (simultaneous B&V bands) will allow a better characterization of the sky properties atop Mauna Kea and will enable a better detection of the thinner cirrus (absorption down to 0.02 mag., i.e. 2%). SkyProbe is operated within the Elixir pipeline, a collection of tools used for handling the CFHT CCD mosaics (CFH12K and MegaCam), from data pre-processing to astrometric and photometric calibration.

Cuillandre, Jean-charles; Magnier, Eugene; Mahoney, William

2011-03-01

313

Determination of Absolute Configuration Using Kinetic Resolution Catalysts  

PubMed Central

A new method was developed to assign the absolute configuration of molecules using kinetic resolution catalysts. Secondary alcohols were acylated in the presence of Birman’s S-HBTM and R-HBTM catalysts, and the fast reacting catalyst was identified by NMR analysis of the reaction mixture. A mnemonic was developed to assign configuration based on the identity of the fast-reacting catalyst. The method uses only 1–3 mg of alcohol, and it is more convenient than the Mosher method. The kinetic resolution strategy may be extended to other classes of molecules. PMID:21776975

Wagner, Alexander J.; David, Jonathan G.

2011-01-01

314

Precision Absolute Beam Current Measurement of Low Power Electron Beam  

SciTech Connect

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.

Ali, M. M.; Bevins, M. E.; Degtiarenko, P.; Freyberger, A.; Krafft, G. A.

2012-11-01

315

Weighted least absolute value state estimation using interior point methods  

SciTech Connect

This paper addresses the application of interior point methods to the Weighted Least Absolute Value state estimation problem. Interior point methods are applied to the primal and dual formulations of the problem. The dual formulation involves solving least squares problems identical in structure to those used in conventional Weighted Least Squares state estimation. The dual formulations also provides an initial feasible interior point without any extra effort. Computational issues that are critical to the success of interior point methods are addressed and test results on standard systems are provided.

Singh, H.; Alvarado, F.L. (Univ. of Wisconsin, Madison, WI (United States). Dept. of Electrical and Computer Engineering)

1994-08-01

316

Network topology determination using least absolute value state estimation  

SciTech Connect

In energy control centers, the estimates of the system state can often be affected by errors in the assumptions made about the topology of the network. This paper introduces a technique that avoids making incorrect assumptions about network status by estimating the status of suspect lines as a part of the state estimation process. This is done by introducing additional variables and measurements in the conventional state estimation problem. The success of the method relies on properties of the Least Absolute Value (LAV) estimator (an estimator that minimizes the {ell}{sub 1} norm of the measurement residuals). The performance of the method is demonstrated on standard test systems.

Singh, H.; Alvarado, F.L. [Univ. of Wisconsin, Madison, WI (United States). Dept. of Electrical and Computer Engineering] [Univ. of Wisconsin, Madison, WI (United States). Dept. of Electrical and Computer Engineering

1995-08-01

317

On absolutely minimizing lipschitz extensions and PDE  

Microsoft Academic Search

.  We prove the existence of Absolutely Minimizing Lipschitz Extensions by a method which differs from those used by G. Aronsson\\u000a in general metrically convex compact metric spaces and R. Jensen in Euclidean spaces. Assuming Jensen’s hypotheses, our method\\u000a yields numerical schemes for computing, in euclidean \\u000a $${\\\\mathbb{R}}^n$$\\u000a , the solution of viscosity of equation \\u000a $$\\\\Delta_\\\\infty (u) = 0$$\\u000a with Dirichlet’s condition.

E. Le Gruyer

2007-01-01

318

Diffractive incremental and absolute coding principle for optical rotary sensors.  

PubMed

Rotary sensors are an essential component in numerous applications where a rotation movement has to be detected. With optical encoders, a high angular resolution can be achieved. As a disadvantage, the resolution enhancement is associated with increasing cost. To overcome this issue, a coding principle is presented that uses a diffractive solid measure on a microstructured plastic disc. Like a DVD, this encoder disc can be manufactured in a cost effective injection molding process. For this approach, a differential incremental code, as well as an absolute code, has been developed. PMID:21947000

Hopp, David; Pruss, Christof; Osten, Wolfgang; Seybold, Jonathan; Fritz, Karl-Peter; Botzelmann, Tim; Mayer, Volker; Kück, Heinz

2011-09-10

319

New ultrahigh-sensitivity absolute, linear, and rotary encoders  

NASA Astrophysics Data System (ADS)

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 reliability, 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 demonstrated sensitivity of 10 nm (0.01 micrometers ) with higher sensitivities possible.

Leviton, Douglas B.

1998-10-01

320

Absolute calibration of a CCD camera with twin beams  

E-print Network

We report on the absolute calibration of a CCD camera by exploiting quantum correlation. This novel method exploits a certain number of spatial pairwise quantum correlated modes produced by spontaneous parametric-down-conversion. We develop a measurement model taking into account all the possible source of losses and noise that are not related to the quantum efficiency,accounting for all the uncertainty contributions, and we reach the relative uncertainty of 0.3% in low photon flux regime. This represents a significant step forward for the characterizaion of (scientific) CCDs used in mesoscopic light regime.

I. Ruo-Berchera; A. Meda; I. P. Degiovanni; G. Brida; M. L. Rastello; M. Genovese

2014-05-07

321

Absolute photoionization cross-section of the methyl radical.  

SciTech Connect

The absolute photoionization cross-section of the methyl radical has been measured using two completely independent methods. The CH{sub 3} photoionization cross-section was determined relative to that of acetone and methyl vinyl ketone at photon energies of 10.2 and 11.0 eV by using a pulsed laser-photolysis/time-resolved synchrotron photoionization mass spectrometry method. The time-resolved depletion of the acetone or methyl vinyl ketone precursor and the production of methyl radicals following 193 nm photolysis are monitored simultaneously by using time-resolved synchrotron photoionization mass spectrometry. Comparison of the initial methyl signal with the decrease in precursor signal, in combination with previously measured absolute photoionization cross-sections of the precursors, yields the absolute photoionization cross-section of the methyl radical; {sigma}{sub CH}(10.2 eV) = (5.7 {+-} 0.9) x 10{sup -18} cm{sup 2} and {sigma}{sub CH{sub 3}}(11.0 eV) = (6.0 {+-} 2.0) x 10{sup -18} cm{sup 2}. The photoionization cross-section for vinyl radical determined by photolysis of methyl vinyl ketone is in good agreement with previous measurements. The methyl radical photoionization cross-section was also independently measured relative to that of the iodine atom by comparison of ionization signals from CH{sub 3} and I fragments following 266 nm photolysis of methyl iodide in a molecular-beam ion-imaging apparatus. These measurements gave a cross-section of (5.4 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.460 eV, (5.5 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.466 eV, and (4.9 {+-} 2.0) x 10{sup -18} cm{sup 2} at 10.471 eV. The measurements allow relative photoionization efficiency spectra of methyl radical to be placed on an absolute scale and will facilitate quantitative measurements of methyl concentrations by photoionization mass spectrometry.

Taatjes, C. A.; Osborn, D. L.; Selby, T.; Meloni, G.; Fan, H.; Pratt, S. T.; Chemical Sciences and Engineering Division; SNL

2008-01-01

322

Lens transmission measurement for an absolute radiation thermometer  

SciTech Connect

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.

Hao, X.; Yuan, Z.; Lu, X. [Division of Thermometry and Materials Evaluation, National Institute of Metrology, Beijing (China)] [Division of Thermometry and Materials Evaluation, National Institute of Metrology, Beijing (China)

2013-09-11

323

Measurement of absolute photoluminescence quantum efficiencies in conjugated polymers  

NASA Astrophysics Data System (ADS)

Measurements of absolute photoluminescence (PL) efficiencies have been performed for solid films of several conjugated polymers commonly used for electroluminescence. In poly( p-phenylenevinylene) (PPV), a PL efficiency of 0.27 is measured in samples which show an initial PL decay time-constant of 320 ps. These values indicate that photoexcitation in PPV produces intra-chain singlet excitons with a high quantum yield. The PL efficiencies of derivatives of PPV have been investigated, and efficiencies in excess of 0.4 have been measured for cyano-substituted PPVs.

Greenham, N. C.; Samuel, I. D. W.; Hayes, G. R.; Phillips, R. T.; Kessener, Y. A. R. R.; Moratti, S. C.; Holmes, A. B.; Friend, R. H.

1995-07-01

324

On the convective-absolute nature of river bedform instabilities  

NASA Astrophysics Data System (ADS)

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.

Vesipa, Riccardo; Camporeale, Carlo; Ridolfi, Luca; Chomaz, Jean Marc

2014-12-01

325

Method of differential-phase/absolute-amplitude QAM  

DOEpatents

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.

Dimsdle, Jeffrey William (Overland Park, KS)

2008-10-21

326

Measurements of Absolute Hadronic Branching Fractions of D Mesons  

E-print Network

Using e+e- collisions recorded at the psi(3770) resonance with the CLEO-c detector at the Cornell Electron Storage Ring, we determine absolute hadronic branching fractions of charged and neutral D mesons. Among measurements for both Cabibbo-favored and Cabibbo-suppressed modes, we obtain reference branching fractions B(D0 -> K-pi+)=(3.91 +- 0.08 +- 0.09)% and B(D+ -> K-pi+pi+)=(9.5 +- 0.2 +- 0.3)%, where the uncertainties are statistical and systematic, respectively. Using a determination of the integrated luminosity, we also extract the e+e- -> DDbar cross sections.

Werner M. Sun

2006-03-15

327

Flash Card Pass-Around (Intro to Integers, absolute value)  

NSDL National Science Digital Library

To give them an opportunity to practice double negatives and absolute values, students do several practice problems with them, but with a twist. Every student gets a flashcard with a problem on it and they are told that they need to trade their card with somebody else until they have seen all 12 problems. In this way, every student practices 12 distinct problems and must work with other students to get the cards they need, which promotes student interaction. When the activity is finished, students come together as a class to discuss the answers they got to each of the problems.

2010-01-01

328

First absolute mass measurements of short-lived isotopes  

NASA Astrophysics Data System (ADS)

Absolute mass measurements of short-lived isotopes have been performed at the on-line mass separator ISOLDE at CERN by determining the cyclotron frequencies of ions confined in a Penning trap. The cyclotron frequencies for77,78,85,86,88Rb and88Sr ions could be determined with a resolving power of 3×105 and an accuracy of better than 10-6, which corresponds to 100 keV for mass A=100. The shortest-lived isotope under investigation was77Rb with a half-life of 3.7 min. The resonances obtained for the isobars88Rb and88Sr were clearly resolved.

Bollen, G.; Dabkiewicz, P.; Egelhof, P.; Hilberath, T.; Kalinowsky, H.; Kern, F.; Schnatz, H.; Schweikhard, L.; Stolzenberg, H.; Moore, R. B.; Kluge, H.-J.; Temmer, G. M.; Ulm, G.

1987-12-01

329

Primary activity standardization of ??Tc by three different absolute methods.  

PubMed

The activity concentration of a solution of (99)Tc was absolutely determined by liquid scintillation measurements based on the triple-to double-coincidence ratio method (TDCR) and compared with the results given by 4??(LS)-?(NaI) live-timed anticoincidence (with extending dead-time) and classical 4??(PC)-?(NaI) coincidence counting systems based on using (60)Co as the efficiency-tracing radionuclide. The results of anticoincidence and coincidence counting are, respectively, 0.18% and 0.66% higher than the result from TDCR measurements, but they are consistent within uncertainties. PMID:24365467

da Cruz, Paulo A L; da Silva, Carlos J; Moreira, Denise S; Iwahara, Akira; Tauhata, Luiz; Lopes, Ricardo T

2014-05-01

330

Absolute cross-section normalization of magnetic neutron scattering data  

NASA Astrophysics Data System (ADS)

We discuss various methods to obtain the resolution volume for neutron scattering experiments, in order to perform absolute normalization on inelastic magnetic neutron scattering data. Examples from previous experiments are given. We also try to provide clear definitions of a number of physical quantities which are commonly used to describe neutron magnetic scattering results, including the dynamic spin correlation function and the imaginary part of the dynamic susceptibility. Formulas that can be used for general purposes are provided and the advantages of the different normalization processes are discussed.

Xu, Guangyong; Xu, Zhijun; Tranquada, J. M.

2013-08-01

331

1 Thermal diffusivity of olivine single-crystals and polycrystalline 2 aggregates at ambient conditions--a comparison  

E-print Network

1 Thermal diffusivity of olivine single-crystals and polycrystalline 2 aggregates at ambient mantle materials highlights a large 16 scatter of absolute values of thermal diffusivity. In 17. Here 19 we present new thermal diffusivity measurements on San 20 Carlos olivine single crystals

Tommasi, Andrea

332

Absolute cross sections for elastic electron scattering from methylformamide  

NASA Astrophysics Data System (ADS)

Elastic electron scattering from gaseous methylformamide (N-methylformamide, C2H5NO) has been investigated. Absolute elastic differential cross sections (DCSs) were determined both experimentally and theoretically for the incident energies from 50 to 300 eV. The measurements were performed using a cross-beam technique, for scattering angles from 20° to 110°. Relative elastic DCSs were measured as a function of both the angle and the incident energy and the absolute DCSs were determined using the relative flow method. The calculations of electron interaction cross sections are based on a corrected form of the independent-atom method, known as the SCAR (screen corrected additivity rule) procedure and using an improved quasifree absorption model. Calculated integral cross sections have been presented, as well, both for methylformamide and formamide, in the energy range 10-1000 eV, and discussed. The results are compared with and discussed regarding existing data for other small molecules representing building blocks of large biomolecules.

Maljkovi?, J. B.; Blanco, F.; García, G.; Marinkovi?, B. P.; Milosavljevi?, A. R.

2012-04-01

333

Absolute counting of neutrophils in whole blood using flow cytometry.  

PubMed

Absolute neutrophil count (ANC) is used clinically to monitor physiological dysfunctions such as myelosuppression or infection. In the research laboratory, ANC is a valuable measure to monitor the evolution of a wide range of disease states in disease models. Flow cytometry (FCM) is a fast, widely used approach to confidently identify thousands of cells within minutes. FCM can be optimised for absolute counting using spiked-in beads or by measuring the sample volume analysed. Here we combine the 1A8 antibody, specific for the mouse granulocyte protein Ly6G, with flow cytometric counting in straightforward FCM assays for mouse ANC, easily implementable in the research laboratory. Volumetric and Trucount™ bead assays were optimized for mouse neutrophils, and ANC values obtained with these protocols were compared to ANC measured by a dual-platform assay using the Orphee Mythic 18 veterinary haematology analyser. The single platform assays were more precise with decreased intra-assay variability compared with ANC obtained using the dual protocol. Defining ANC based on Ly6G expression produces a 15% higher estimate than the dual protocol. Allowing for this difference in ANC definition, the flow cytometry counting assays using Ly6G can be used reliably in the research laboratory to quantify mouse ANC from a small volume of blood. We demonstrate the utility of the volumetric protocol in a time-course study of chemotherapy induced neutropenia using four drug regimens. PMID:24995861

Brunck, Marion E G; Andersen, Stacey B; Timmins, Nicholas E; Osborne, Geoffrey W; Nielsen, Lars K

2014-12-01

334

Accurate absolute parameters of the binary system V4089 Sgr  

NASA Astrophysics Data System (ADS)

We carried out a spectroscopic and photometric analysis of the binary V4089 Sgr with the aim to obtain absolute masses and radii of the components and to compare these parameters with stellar evolution theoretical models. We took high-resolution spectra and measured radial velocity using standard cross-correlations and a technique of spectral disentangling. Absolute parameters of the components were determined through the simultaneous fitting of measured radial velocities and Geneva photometric data available in the literature. In this way we obtained MA=2.584±0.008 M?, MB=1.607±0.007 M?, RA=3.959±0.013 R?, and RB=1.605±0.016 R?. The comparison of these parameters with two grids of theoretical models led to estimate narrow ranges of possible values for system metallicity and age. According to circularization theory it was not expected that the binary had achieved a circular orbit as a result of tidal friction, so the null eccentricity found is an interesting fact. On the other hand, we measured the projected rotational velocity of both components and we conclude that the primary is not synchronized with orbital motion.

Veramendi, M. E.; González, J. F.

2015-01-01

335

Absolute cross sections for elastic electron scattering from 3-hydroxytetrahydrofuran  

NASA Astrophysics Data System (ADS)

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).

Milosavljevi?, A. R.; Blanco, F.; Maljkovi?, J. B.; Ševi?, D.; García, G.; Marinkovi?, B. P.

2008-10-01

336

Use of intensity quotients and differences in absolute structure refinement.  

PubMed

Several methods for absolute structure refinement were tested using single-crystal X-ray diffraction data collected using Cu K? radiation for 23 crystals with no element heavier than oxygen: conventional refinement using an inversion twin model, estimation using intensity quotients in SHELXL2012, estimation using Bayesian methods in PLATON, estimation using restraints consisting of numerical intensity differences in CRYSTALS and estimation using differences and quotients in TOPAS-Academic where both quantities were coded in terms of other structural parameters and implemented as restraints. The conventional refinement approach yielded accurate values of the Flack parameter, but with standard uncertainties ranging from 0.15 to 0.77. The other methods also yielded accurate values of the Flack parameter, but with much higher precision. Absolute structure was established in all cases, even for a hydrocarbon. The procedures in which restraints are coded explicitly in terms of other structural parameters enable the Flack parameter to correlate with these other parameters, so that it is determined along with those parameters during refinement. PMID:23719469

Parsons, Simon; Flack, Howard D; Wagner, Trixie

2013-06-01

337

Closed-loop step motor control using absolute encoders  

SciTech Connect

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.

Hicks, J.S.; Wright, M.C.

1997-08-01

338

Absolute Quantification of Selected Proteins in the Human Osteoarthritic Secretome  

PubMed Central

Osteoarthritis (OA) is characterized by a loss of extracellular matrix which is driven by catabolic cytokines. Proteomic analysis of the OA cartilage secretome enables the global study of secreted proteins. These are an important class of molecules with roles in numerous pathological mechanisms. Although cartilage studies have identified profiles of secreted proteins, quantitative proteomics techniques have been implemented that would enable further biological questions to be addressed. To overcome this limitation, we used the secretome from human OA cartilage explants stimulated with IL-1? and compared proteins released into the media using a label-free LC-MS/MS-based strategy. We employed QconCAT technology to quantify specific proteins using selected reaction monitoring. A total of 252 proteins were identified, nine were differentially expressed by IL-1 ? stimulation. Selected protein candidates were quantified in absolute amounts using QconCAT. These findings confirmed a significant reduction in TIMP-1 in the secretome following IL-1? stimulation. Label-free and QconCAT analysis produced equivocal results indicating no effect of cytokine stimulation on aggrecan, cartilage oligomeric matrix protein, fibromodulin, matrix metalloproteinases 1 and 3 or plasminogen release. This study enabled comparative protein profiling and absolute quantification of proteins involved in molecular pathways pertinent to understanding the pathogenesis of OA. PMID:24132152

Peffers, Mandy J.; Beynon, Robert J.; Clegg, Peter D.

2013-01-01

339

Obtaining absolute acoustic spectra in an aerodynamic wind tunnel  

NASA Astrophysics Data System (ADS)

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.

Quayle, Alexander R.; Dowling, Ann P.; Graham, W. R.; Babinsky, H.

2011-05-01

340

Absolute and relative quantification of RNA modifications via biosynthetic isotopomers.  

PubMed

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 (13)C-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

Kellner, Stefanie; Ochel, Antonia; Thüring, Kathrin; Spenkuch, Felix; Neumann, Jennifer; Sharma, Sunny; Entian, Karl-Dieter; Schneider, Dirk; Helm, Mark

2015-01-01

341

Enabling Dark Energy and Beyond Science with Precise Absolute Photometry  

NASA Astrophysics Data System (ADS)

We have obtain WFC3/IR observations of 15 carefully selected stars with the immediate objective of establishing their Absolute Physical Flux (ABF), and an ultimate goal of achieving the sub-1% absolute photometric accuracies required by Dark Energy science with JWST and other facilities. Even with the best data available, the current determination of ABFs is plagued by the reliance on the Vega photometric system, which is known to be problematic primarily due to the fact that Vega is a pole-on rapid rotator with an infrared excess from its circumstellar disk! which makes it difficult to model. Vega is also far too bright for large aperture telescopes. In an effort to remedy these difficulties, teams from the National Institute of Standards (NIST), the University of New Mexico, Johns Hopkins University and STScI have begun to develop a catalog of stars that have spectral energy distributions that are tied directly to NIST (diode) standards with very precisely determined physical characteristics. A key element in this pursuit has been the efforts at STScI to measure the spectra of many of these objects with STIS. We discuss our program to extend this effort into the near-IR which is crucial to reliably extend the SEDs to longer wavelengths, including the mid IR.

Deustua, Susana E.; Hines, D. C.; Bohlin, R.; Gordon, K. D.

2014-01-01

342

Absolute bioavailability and metabolism of aceclofenac in rats.  

PubMed

Aceclofenac is one of the most popular analgesic and anti-inflammatory drugs used for the relief of pain, rheumatoid arthritis, and osteoarthritis. To date, no intravenous preparation of aceclofenac has been developed because of its poor water solubility. In this study, to investigate its absolute bioavailability and metabolism in rats, aceclofenac was dissolved in a sterile aqueous solution containing urea (20 %) and trisodium citrate (10 %), and administered via oral (20 mg/kg) and intravenous (10 mg/kg) routes. Blood samples were taken serially, and aceclofenac and its three major metabolites (4'-hydroxydiclofenac, 4'-hydroxyaceclofenac, and diclofenac) were measured by HPLC-MS/MS. The absolute oral bioavailability of aceclofenac was approximately 15 %. Diclofenac and 4'-hydroxydiclofenac were the main metabolites in rats, in contrast to 4'-hydroxyaceclofenac in humans. The low bioavailability of aceclofenac is likely due to extensive metabolism, and bioavailability may be even lower if the drug were administered as a tablet, considering its low water solubility. This study provides complete time profiles of the plasma concentrations of aceclofenac and its metabolites in rats and highlights the difference in drug metabolism between rats and humans. PMID:24633464

Noh, Keumhan; Shin, Beom Soo; Kwon, Kwang-Il; Yun, Hwi-Yeol; Kim, Eunyoung; Jeong, Tae Cheon; Kang, Wonku

2015-01-01

343

Absolute Calibration of the AXAF Telescope Effective Area  

NASA Technical Reports Server (NTRS)

The prelaunch calibration of AXAF encompasses many aspects of the telescope. In principle, all that is needed is the complete point response function. This is, however, a function of energy, off-axis angle of the source, and operating mode of the facility. No single measurement would yield the entire result. Also, any calibration made prior to launch will be affected by changes in conditions after launch, such as the change from one g to zero g. The reflectivity of the mirror and perhaps even the detectors can change as well, for example by addition or removal of small amounts of material deposited on their surfaces. In this paper, we give a broad view of the issues in performing such a calibration, and discuss how they are being addressed in prelaunch preparation of AXAF. As our title indicates, we concentrate here on the total throughput of the observatory. This can be thought of as the integral of the point response function, i.e. the encircled energy, out ot the largest practical solid angle for an observation. Since there is no standard x-ray source in the sky whose flux is known to the -1% accuracy we are trying to achieve, we must do this calibration on the ground. we also must provide a means for monitoring any possible changes in this calibration from pre-launch until on-orbit operation can transfer the calibration to a celestial x-ray source whose emission is stable. In this paper, we analyze the elements of the absolute throughput calibration, which we call Effective Area. We review the requirements for calibrations of components or subsystems of the AXAF facility, including mirror, detectors, and gratings. We show how it is necessary to calibrate this ground-based detection system at standard man-made x-ray sources, such as electron storage rings. We present the status of all these calibrations, with indications of the measurements remaining to be done, even though the measurements on the AXAF flight optics and detectors will have been completed by the time this paper is presented. We evaluate progress toward the goal of making 1% measurements of the absolute x-ray flux from astrophysical sources, so that comparisons can be made with their emission at other wavelengths, in support of observations such as the Sunyaev-Zeldovitch effect, which can give absolute distance measurements independent of the traditional distance measuring techniques in astronomy.

Kellogg, E.; Cohen, L.; Edgar, R.; Evans, I.; Freeman, M.; Gaetz, T.; Jerius, D.; McDermott, W. C.; McKinnon, P.; Murray, S.; Podgorski, W.; Schwartz, D.; VanSpeybroeck, L.; Wargelin, B.; Zombeck, M.; Weisskopf, M.; Elsner, R.; ODell, S.; Tennant, A.; Kolodziejczak, J.

1997-01-01

344

The thermal conductivity of liquid mixtures at elevated pressures  

Microsoft Academic Search

This paper reports new, absolute measurements of the thermal conductivity of liquid mixtures of n-heptane and isooctane in the pressure range 0.1 to 430 MPa for temperatures of 307.85 and 337.15 K. The results represent a preliminary investigation of the advantages of attempting to describe the isothermal composition dependence of the thermal conductivity of liquid mixtures along isochores, rather than

J. M. N. A. Fareleira; S. F. Y. Li; W. A. Wakeham

1989-01-01

345

Absolute calibration of fiber-coupled single-photon detector.  

PubMed

We show a setup for characterising the efficiency of a single-photon-detector absolutely and with a precision better than 1%. Since the setup does not rely on calibrated devices and can be implemented with standard-optic components, it can be realised in any laboratory. Our approach is based on an Erbium-Doped-Fiber-Amplifier (EDFA) radiometer as a primary measurement standard for optical power, and on an ultra-stable source of spontaneous emission. As a proof of principle, we characterise the efficiency of an InGaAs/InP single-photon detector. We verified the correctness of the characterisation with independent measurements. In particular, the measurement of the optical power made with the EDFA radiometer has been compared to that of the Federal Institute of Metrology using a transfer power meter. Our approach is suitable for frequent characterisations of high-efficient single-photon detectors. PMID:25089427

Lunghi, Tommaso; Korzh, Boris; Sanguinetti, Bruno; Zbinden, Hugo

2014-07-28

346

An absolute scale for measuring the utility of money  

NASA Astrophysics Data System (ADS)

Measurement of the utility of money is essential in the insurance industry, for prioritising public spending schemes and for the evaluation of decisions on protection systems in high-hazard industries. Up to this time, however, there has been no universally agreed measure for the utility of money, with many utility functions being in common use. In this paper, we shall derive a single family of utility functions, which have risk-aversion as the only free parameter. The fact that they return a utility of zero at their low, reference datum, either the utility of no money or of one unit of money, irrespective of the value of risk-aversion used, qualifies them to be regarded as absolute scales for the utility of money. Evidence of validation for the concept will be offered based on inferential measurements of risk-aversion, using diverse measurement data.

Thomas, P. J.

2010-07-01

347

Absolute ball bearing wear measurements from SSME turbopump dynamic signals  

NASA Astrophysics Data System (ADS)

This paper describes how absolute ball bearing wear is measured in an operating turbopump from heavily loaded ball bearing vibration signatures. This technique was developed during testing of the High Pressure Oxygen Turbopump (HPOTP) of the Space Shuttle Main Engine (SSME). A linear correlation was established between the cage frequency harmonic amplitudes on internal strain gages and the measured ball wear from pump disassembly. In a manner similar to that used by Sunnersjö [1] for lightly loaded roller bearings, the dominant cage harmonics in the vibration spectra were shown to correspond to those of a Fourier series representation of the circumferential ball diameter variation or wear pattern. Strain gages and accelerometers on the external pump casing also show similar wear symptoms. These external measurements allow convenient wear monitoring for pre-flight testing of the SSME.

Hine, M. J.

1989-01-01

348

Absolute calibration of fiber-coupled single-photon detector  

E-print Network

We show a setup for characterising the efficiency of a single-photon-detector absolutely and with a precision better of 1%. Since the setup does not rely on calibrated devices and can be implemented with standard-optic components, it can be realised in any laboratory. Our approach is based on an Erbium-Doped-Fiber-Amplifier (EDFA) radiometer as a primary measurement standard for optical power, and on an ultra-stable source of spontaneous emission. As a proof of principle, we characterise the efficiency of an InGaAs/InP single-photon detector. We verified the correctness of the characterisation with independent measurements. In particular, the measurement of the optical power made with the EDFA radiometer has been compared to that of the Swiss Federal Office of Metrology using a transfer power meter. Our approach is suitable for frequent characterisations of high-efficient single-photon detectors.

Tommaso Lunghi; Boris Korzh; Bruno Sanguinetti; Hugo Zbinden

2014-04-14

349

Absolute calibration of fiber-coupled single-photon detector  

E-print Network

We show a setup for characterising the efficiency of a single-photon-detector absolutely and with a precision better of 1%. Since the setup does not rely on calibrated devices and can be implemented with standard-optic components, it can be realised in any laboratory. Our approach is based on an Erbium-Doped-Fiber-Amplifier (EDFA) radiometer as a primary measurement standard for optical power, and on an ultra-stable source of spontaneous emission. As a proof of principle, we characterise the efficiency of an InGaAs/InP single-photon detector. We verified the correctness of the characterisation with independent measurements. In particular, the measurement of the optical power made with the EDFA radiometer has been compared to that of the Swiss Federal Office of Metrology using a transfer power meter. Our approach is suitable for frequent characterisations of high-efficient single-photon detectors.

Lunghi, Tommaso; Sanguinetti, Bruno; Zbinden, Hugo

2014-01-01

350

The chromospherically active binary star EI Eridani I. Absolute dimensions  

E-print Network

We present a detailed determination of the astrophysical parameters of the chromospherically active binary star EI Eridani. Our new radial velocities allow to improve the set of orbital elements and reveal long-term variations of the barycentric velocity. A possible third-body orbit with a period of approximately 19 years is presented. Absolute parameters are determined in combination with the Hipparcos parallax. EI Eri's inclination angle of the rotational axis is confined to 56.0 plus/minus 4.5 degrees, its luminosity class IV is confirmed by its radius of 2.37 plus/minus 0.12 R_Sun. A comparison to theoretical stellar evolutionary tracks suggests a mass of 1.09 plus/minus 0.05 M_Sun and an age of approximately 6.15 Gyr. The present investigation is the basis of our long-term Doppler imaging study of its stellar surface.

A. Washuettl; K. G. Strassmeier; T. Granzer; M. Weber; K. Oláh

2008-09-04

351

Absolute measurements of chlorine Cl+ cation single photoionization cross section  

NASA Astrophysics Data System (ADS)

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.

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

352

Absolute stellar photometry on moderate-resolution FPA images  

USGS Publications Warehouse

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.

Stone, T.C.

2009-01-01

353

An Alpha-Gamma Counter for Absolute Neutron Flux Measurement  

NASA Astrophysics Data System (ADS)

An alpha-gamma counter was used to measure the absolute neutron flux of a monochromatic cold neutron beam to sub-0.1,% precision. Simultaneously, the counter was used to calibrate a thin neutron flux monitor based on neutron absorption on ^6Li to the same precision. This monitor was used in the most precise beam-based measurement of the neutron lifetime, where the limiting systematic effect was the uncertainty in the neutron counting efficiency (0.3,%). The counter uses a thick target of ^10B-enriched boron carbide to completely absorb the beam. The rate of absorbed neutrons is determined by counting 478 keV gamma rays from neutron capture on ^10B with calibrated high-purity germanium detectors. The calibration results and the implications for the neutron lifetime will be discussed.

Yue, A.; Greene, G.; Dewey, M.; Gilliam, D.; Nico, J.; Laptev, A.

2012-03-01

354

A novel diffractive encoding principle for absolute optical encoders  

NASA Astrophysics Data System (ADS)

Rotary and linear position sensors are used in numerous manufacturing and automotive applications, where cost effectiveness and the ability of integration are major goals. To meet the increasing demand for competitive optical rotary encoders, in recent years a novel type of optical encoders have been proposed and demonstrated using a micro grating based encoding scheme. This proceeding will give details on the operation principle of this novel kind of position encoder and will show its performance on two exemplary implementations: A compact absolute rotary encoder with a micro-structured plastic disc, which can be manufactured in a conventional and cost effective DVD-molding process and a linear encoder which is based on a pseudo-random coding scheme. The implementation as well as results from their experimental characterization are presented.

Hopp, D.; Wibbing, D.; Pruss, C.; Osten, W.; Binder, J.; Schinköthe, W.; Sterns, F.; Seybold, J.; Fritz, K.-P.; Mayer, V.; Kück, H.

2011-05-01

355

ABSOLUTE PROPERTIES OF THE ECLIPSING BINARY STAR HY VIRGINIS  

SciTech Connect

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.

Sandberg Lacy, Claud H. [Physics Department, University of Arkansas, Fayetteville, AR 72701 (United States); Fekel, Francis C., E-mail: clacy@uark.edu, E-mail: fekel@evans.tsuniv.edu [Center of Excellence in Information Systems, Tennessee State University, Nashville, TN 37209 (United States)

2011-12-15

356

ABSOLUTE PROPERTIES OF THE ECLIPSING BINARY STAR V335 SERPENTIS  

SciTech Connect

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.

Lacy, Claud H. Sandberg [Physics Department, University of Arkansas, Fayetteville, AR 72701 (United States); Fekel, Francis C. [Center of Excellence in Information Systems, Tennessee State University, Nashville, TN 37209 (United States); Claret, Antonio, E-mail: clacy@uark.edu, E-mail: fekel@evans.tsuniv.edu, E-mail: claret@iaa.es [Instituto de Astrofisica de Andalucia, CSIC, Apdo. Postal 3004, E-18080 Granada (Spain)

2012-08-15

357

ABSOLUTE PROPERTIES OF THE TRIPLE STAR CF TAURI  

SciTech Connect

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.

Lacy, Claud H. Sandberg [Physics Department, University of Arkansas, Fayetteville, AR 72701 (United States); Torres, Guillermo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Claret, Antonio, E-mail: clacy@uark.edu, E-mail: gtorres@cfa.harvard.edu, E-mail: claret@iaa.es [Instituto de Astrofisica de Andalucia, CSIC, Apdo. Postal 3004, E-18080 Granada (Spain)

2012-12-01

358

Lunar eclipse photometry: absolute luminance measurements and modeling.  

PubMed

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

Hernitschek, Nina; Schmidt, Elmar; Vollmer, Michael

2008-12-01

359

Absolute Properties of the Eclipsing Binary Star IM Persei  

NASA Astrophysics Data System (ADS)

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.

Lacy, Claud H. Sandberg; Torres, Guillermo; Fekel, Francis C.; Muterspaugh, Matthew W.; Southworth, John

2015-01-01

360

Absolute luminescence efficiency of ion-bombarded solid argon  

NASA Astrophysics Data System (ADS)

We have directly measured the absolute efficiency of the 9.8-eV M-band luminescence from the decay of Ar*2 excimers in solid Ar bombarded by 1.5-MeV He+ and 10-50-keV H+ ions. About 54% of the electronic energy deposited by the projectiles is converted to 9.8-eV luminescence energy, or about 5.5 photons per 100-eV deposited. The efficiency is also found to be independent of ion and ion energy for those tested over a range of stopping cross sections from 6.5 to 400 eV/(1015 atoms/cm2). This work clearly establishes the M band as the major relaxation pathway for electronically deposited energy in solid Ar, a pathway that is an important source of radiation damage and sputtering and which can be affected by electron emission.

Grosjean, D. E.; Vidal, R. A.; Baragiola, R. A.; Brown, W. L.

1997-09-01

361

Upgrade of absolute extreme ultraviolet diagnostic on J-TEXT.  

PubMed

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. PMID:25430327

Zhang, X L; Cheng, Z F; Hou, S Y; Zhuang, G; Luo, J

2014-11-01

362

Absolute Rayleigh Intensity and Uniform Optical Conductivity in Carbon Nanotubes  

NASA Astrophysics Data System (ADS)

We used a novel on-chip Rayleigh imaging technique to measure the absolute intensity of Rayleigh scattering of single-walled carbon nanotubes. The spatial distribution of the radiation scattered by the nanotubes is determined by their shape, but the intensity and spectrum of the scattered radiation are determined by exciton dynamics, quantum-dot-like optical resonances and other intrinsic properties. Moreover, the nanotubes display a uniform peak optical conductivity ˜8 ê2/ h, which we derive using an exciton model, suggesting universal behaviour similar to that observed in nanotube conductance. We further demonstrate a radiative coupling between two distant nanotubes, with potential applications in metamaterials and optical antennae. This is in contrast to the optical properties of metal nanostructures and show that nanotubes can form ideal optical wires.

Herman, Lihong; Joh, Daniel; Kinder, Jesse; Ju, Sang-Yong; Segal, Michael; Johnson, Jeffreys; Chan, Garnet; Park, Jiwoong

2011-03-01

363

Early results from the Far Infrared Absolute Spectrophotometer (FIRAS)  

NASA Technical Reports Server (NTRS)

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.

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

364

Full field imaging based instantaneous hyperspectral absolute refractive index measurement  

SciTech Connect

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.

Baba, Justin S [ORNL; Boudreaux, Philip R [ORNL

2012-01-01

365

Absolute Radiation Measurements in Earth and Mars Entry Conditions  

NASA Technical Reports Server (NTRS)

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.

Cruden, Brett A.

2014-01-01

366

Absolute Measurement of Tilts via Fourier Analysis of Interferograms  

NASA Technical Reports Server (NTRS)

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.

Toland, Ronald W.

2004-01-01

367

Absolute Measurement of Tilts via Fourier Analysis of Interferograms  

NASA Technical Reports Server (NTRS)

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.

Toland, Ronald W.

2004-01-01

368

Absolute Magnitude Calibration of Geneva Photometry: B-type Stars  

NASA Astrophysics Data System (ADS)

The Hipparcos data give us access, for the first time, to trigonometric parallaxes of B-type stars. This allows us to refine and re-adjust extant empirical absolute magnitude calibrations of the Geneva X and Y reddening-free photometric parameters on the basis of the parallaxes that are presently available. The new calibration presented here, which is totally independent of other data, is compared with results that were derived with earlier versions. Its validity regarding a selection of Ap stars is tested on the basis of their Hipparcos parallaxes. The calibration must, however, not be considered to be optimal until the whole Hipparcos and Tycho data are distributed and enable a definitive study to be undertaken.

Cramer, N.

1997-08-01

369

The Absolute Calibration of the EUV Imaging Spectrometer on Hinode  

NASA Astrophysics Data System (ADS)

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.

Warren, Harry P.; Ugarte-Urra, Ignacio; Landi, Enrico

2014-07-01

370

Method and apparatus for making absolute range measurements  

DOEpatents

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.

Earl, Dennis D. (Knoxville, TN); Allison, Stephen W. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Sanders, Alvin J. (Knoxville, TN)

2002-09-24

371

Absolute Properties of the Eclipsing Binary Star Im Persei  

NASA Astrophysics Data System (ADS)

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.

Sandberg Lacy, Claud H.; Torres, Guillermo; Fekel, Francis C.; Muterspaugh, Matthew W.; Southworth, John

2015-01-01

372

Cylindrical Taylor states conserving total absolute magnetic helicity  

NASA Astrophysics Data System (ADS)

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.

Low, B. C.; Fang, F.

2014-09-01

373

THE ABSOLUTE MAGNITUDE OF RRc VARIABLES FROM STATISTICAL PARALLAX  

SciTech Connect

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.

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 [Observatories of the Carnegie Institution of Washington, 813 Santa Barbara Street, Pasadena, CA 91101 (United States); Szczygie?, Dorota M.; Gould, Andrew [Department of Astronomy, The Ohio State University, 4051 McPherson Laboratory, Columbus, OH 43210 (United States); Sneden, Christopher [Department of Astronomy, University of Texas at Austin, TX 78712 (United States); Dong, Subo [Institute for Advanced Study, 500 Einstein Drive, Princeton, NJ 08540 (United States)

2013-09-20

374

Gravitational Acceleration as a Cue for Absolute Size and Distance  

NASA Technical Reports Server (NTRS)

When an object's motion is influenced by gravity, such as the rise and fall of a thrown ball, the vertical component of acceleration is roughly constant at 9.8 m/sec2. In principle, an observer could use this information to estimate the absolute size and distance of the object (Saxberg, 1987a; Watson, Banks, von Hofsten, & Royden, 1992). In three experiments, we examined the ability to utilize the size and distance information provided by gravitational acceleration. Observers viewed computer simulations of an object rising and falling on a trajectory parallel to the gravitational vector. The simulated objects were three balls of different diameters presented across a wide range of simulated distances. Observers were asked to identify which ball was presented and the distance at which it was presented. The results of Experiment 1 showed that size and distance judgments were significantly better than chance, but not as accurate as expected if the information contained in the dynamics of free fall were used fully utilized. The results of Experiment 2 showed that acceleration information is used, but that observers can also make use of velocity information. Finally, the results of Experiment 3 showed that observers can use projected size information, but that their size and distance judgments are much more accurate when motion information is present as well. These results show that observers can use the information in the dynamics of free fall to estimate absolute size and distance, but their estimates are not as accurate as they could be if the information were used effectively.

Hecht, Heiko; Kaiser, Mary K.; Banks, Martin S.; Hart, Sandra G. (Technical Monitor)

1994-01-01

375

Absolute Calibration of the Extragalactic Mira Period-Luminosity Relation  

NASA Astrophysics Data System (ADS)

In this era of precision measurement of the parameters of the cosmological equation of state, constraining the present-day value of the Hubble constant remains a vital endeavor: uncertainties in H_0 couple directly to imprecision in the matter and dark energy contributions to the evolution of the universe {e.g., w, and w1}. Starting with the HST Key Project more than a decade ago, the uncertainty in H_0 has been cut from over 10% to something approaching 3%. A major advance was made recently, leapfrogging Milky Way calibrations, by directly anchoring the infrared Cepheid Period-Luminosity {PL} relation to NGC 4258, the famous megamaser galaxy with a highly precise geometric distance. We propose to anchor the infrared PL relation of Mira variables to NGC 4258, providing the first-ever absolute extragalactic PL relation of such stars, opening a new avenue for precision H_0 efforts. In the infrared, Miras are comparable in absolute magnitude to Cepheids, and thus are direct complements to Cepheids within the same volume {up to 25 Mpc}. The principal advantage of Miras, however, is that they are 20 times more numerous than Cepheids. Thus, a Mira-focused distance measurement study can cover 5% of the surface area of a Cepheid-focused study and achieve a comparable distance measurement accuracy. Over the 12 proposed visits with WFC3/F160W/F125W, and coupled with previous observations of the field, we expect to discover and characterize 1000 Miras, accurately identifying periods < 550 days. This investment now should demonstrate significant observing efficiency increases for JWST if indeed Miras are found to be an acceptable replacement to Cepheids.

Bloom, Joshua

2013-10-01

376

Absolute Magnitudes of Pan-STARRS 1 Asteroids  

NASA Astrophysics Data System (ADS)

It is well known that the absolute magnitudes (H) in the MPCORB and ASTORB orbital element catalogs suffer from a systematic offset. Juric at al. (2002) found 0.4 mag offset in the SDSS data and detailed light curve studies of WISE asteroids by Pravec et al. (2012) revealed size-dependent offsets of up to 0.5 mag. The offsets are thought to be caused by systematic errors introduced by earlier surveys using different photometric catalogs and filters. The next generation asteroid surveys provide an order of magnitude more asteroids and well-defined and calibrated magnitudes. The Pan-STARRS 1 telescope (PS1) has observed hundreds of thousands asteroids, submitted more than 2 million detections to the Minor Planet Center (MPC) and discovered almost 300 NEOs since the beginning of operations in late 2010. We transformed the observed apparent magnitudes of PS1-detected asteroids from the gP1,rP1,iP1,yP1,zP1 and wP1-bands into Johnson photometric system by assuming the mean S and C-type asteroid color (Fitzsimmons 2011 - personal communication, Schlafly et al. 2012, Magnier et al. 2012 - in preparation) and calculated the absolute magnitude (H) in the V-band and its uncertainty (Bowell et al., 1989) for more than 200,000 known asteroids having on average 6.7 detections per object. The H error with respect to the MPCORB catalog revealed a mean offset of -0.49+0.30 mag in good agreement with published values. We will also discuss the statistical and systematical errors in H and slope parameter G.

Veres, Peter; Jedicke, R.; Denneau, L.; Fitzsimmons, A.; Bolin, B.; Wainscoat, R.; Science Consortium, PS1

2012-10-01

377

On measuring the absolute scale of baryon acoustic oscillations  

NASA Astrophysics Data System (ADS)

The baryon acoustic oscillation (BAO) feature in the distribution of galaxies provides a fundamental standard ruler which is widely used to constrain cosmological parameters. In most analyses, the comoving length of the ruler is inferred from a combination of cosmic microwave background (CMB) observations and theory. However, this inferred length may be biased by various non-standard effects in early universe physics; this can lead to biased inferences of cosmological parameters such as H0, ?m and w, so it would be valuable to measure the absolute BAO length by combining a galaxy redshift survey and a suitable direct low-z distance measurement. One obstacle is that low-redshift BAO surveys mainly constrain the ratio rS/DV(z), where DV is a dilation scale which is not directly observable by standard candles. Here, we find a new approximation DV(z)?34DL(43z)(1+43z)-1(1-0.02455 z3+0.0105 z4) which connects DV to the standard luminosity distance DL at a somewhat higher redshift; this is shown to be very accurate (relative error <0.2 per cent) for all Wilkinson Microwave Anisotropy Probe compatible Friedmann models at z < 0.4, with very weak dependence on cosmological parameters H0, ?m, ?k, w. This provides a route to measure the absolute BAO length using only observations at z ? 0.3, including Type Ia supernovae, and potentially future H0-free physical distance indicators such as gravitational lenses or gravitational wave standard sirens. This would provide a zero-parameter check of the standard cosmology at 103 ? z ? 105, and can constrain the number of relativistic species Neff with fewer degeneracies than the CMB.

Sutherland, Will

2012-10-01

378

New Reference Models for Pacific Absolute Plate Motion  

NASA Astrophysics Data System (ADS)

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.

Wessel, P.

2012-12-01

379

Thermal Conductivity of Liquid InSb and Liquid Ga  

Microsoft Academic Search

The mean thermal conductivity of liquid gallium was measured as 70 ± 7 W m?1 K?1 over the range 250–550 °C. For indium antimonide, Kl = 2.04Ks at the melting temperature with Kl = 9.23 W m?1 K?1 as a reasonable absolute value.

R. G. Seidensticker; M. Rubenstein

1972-01-01

380

Preparation and Thermal Decompositionof Platinum(Il) Metallocycles1  

E-print Network

- PPh: i the initial concentration of the platinum complex was 0.025 M. Yields are relative; absolute of kinetic data obtained at 50, 60, and 70'. d A mixture of two platinum complexes, epimeric with respectPreparation and Thermal Decompositionof Platinum(Il) Metallocycles1 Sir.' We wish to report

Prentiss, Mara

381

A general variational principle for thermal insulation system design  

Microsoft Academic Search

The paper proposes a conceptually new method for thermal insulation system optimization. The method, based on minimizing thermodynamic irreversibility, consists of externally controlling the variation of heat leak with temperature across the insulation. It is demonstrated that the useful power savings registered from applying this design philosophy are important. Prime candidates for this method are insulation systems facing high absolute

Adrian Bejan

1979-01-01

382

Thermal conductivity of liquid InSb and liquid Ga.  

NASA Technical Reports Server (NTRS)

The mean thermal conductivity of liquid gallium was measured as 70 (plus or minus 7) W/m/K over the range 250-550 C. For indium antimonide, Kl = 2.04Ks at the melting temperature with Kl = 9.23 W/m/K- as a reasonable absolute value.

Seidensticker, R. G.; Rubenstein, M.

1972-01-01

383

The essential linearity of thermal radiation net transport  

Microsoft Academic Search

Thermal radiation net transport is proportional to the difference in the fourth powers of the absolute temperatures of the radiator and the receiver. During a study of heat transfer mechanisms in the underground storage tanks for the radioactive wastes at the Hanford Site in Washington, it was discovered that the fourth power difference is approximated by a linear function of

J. J. Barker

1991-01-01

384

Variation in thermal performance and reaction norms among populations of Drosophila melanogaster.  

PubMed

The major goal of evolutionary thermal biology is to understand how variation in temperature shapes phenotypic evolution. Comparing thermal reaction norms among populations from different thermal environments allows us to gain insights into the evolutionary mechanisms underlying thermal adaptation. Here, we have examined thermal adaptation in six wild populations of the fruit fly (Drosophila melanogaster) from markedly different natural environments by analyzing thermal reaction norms for fecundity, thorax length, wing area, and ovariole number under ecologically realistic fluctuating temperature regimes in the laboratory. Contrary to expectation, we found only minor differences in the thermal optima for fecundity among populations. Differentiation among populations was mainly due to differences in absolute (and partly also relative) thermal fecundity performance. Despite significant variation among populations in the absolute values of morphological traits, we observed only minor differentiation in their reaction norms. Overall, the thermal reaction norms for all traits examined were remarkably similar among different populations. Our results therefore suggest that thermal adaptation in D. melanogaster predominantly involves evolutionary changes in absolute trait values rather than in aspects of thermal reaction norms. PMID:24299409

Klepsatel, Peter; Gáliková, Martina; De Maio, Nicola; Huber, Christian D; Schlötterer, Christian; Flatt, Thomas

2013-12-01

385

Geologic application of thermal-inertia mapping from satellite. [Powder River Basin in Wyoming and Montana  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. The proportional and linear relationship between absolute and relative thermal inertia was theoretically evaluated, and a more accurate expression for thermal inertia was proposed. Radiometric and meteorological data from three stations in the Powder River Basin were acquired, as well as 400 miles of low altitude scanner data between July 25-28.

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

1978-01-01

386

Numerical simulation of thermal-hydraulic generators running in a single regime  

NASA Astrophysics Data System (ADS)

The paper presents the basis for the design of thermal-hydraulic generators running in a single regime. The thermal-hydraulic generators in a single regime running represent an absolute novelty worldwide (a pioneer invention). Based on the methodology concerning this subject, the design calculus for an experimental model was developed.

Chioreanu, Nicolae; Mitran, Tudor; Rus, Alexandru; Beles, Horia

2014-06-01

387

Maine's MOLLOCKET and METALLAK: Adherents of God's Secret Spirit Signal, SSS, Applied Physicists of the EMF/Manitou, Doctors, Reincarnationists, "Potlachers," Confidants of the Powerful, and, they Did Own the Land.  

NASA Astrophysics Data System (ADS)

Northeastern ``Indians,'' reputed to ``make the weather,'' actually, from youth, observed earth phenomena, including SSS. These are subtle and barely detectable visual artifacts of the electromagnetic field, special information that led/leads to their spiritual belief in reincarnation, which came from the EMF/SSS communication, backward and forward, (up to) seven generations. It commands communal, democratic, ``potlatch'' redistribution of accumulated wealth, Mother Earth's bounty, from their land, gifted by ``The Great Spirit,'' Manitou, Peru's Ñari Huallac, ``Serpent God.'' Genetics established the non-Asian origins of 1/3 of North American Indians. Linguistics indicates a major impact westwards to us. MILLInocket is ``Adherent of God (Spirit-signal) monk Cathar.'' Katahdin, with a shared root, has Manitou. After 1820, Gov. E. Lincoln and at least one US senator went westward to MetALLAk; his biography is by a Rumford, ME Knight of Pythias. Why? MOLLOCKET frequently asserted ownership of western Maine. ``Great Council Fires,'' religious ``Law Things,'' were at Merrymeeting Bay in pre-Colonial times. ``Medicine men/priests'' often participated as their applied scientist-statesmen. To cite this abstract, use the following reference: http://meetings.aps.org/link/BAPS.2007.NES07.C2.1

Andrade, Jennifer; Ferreira, Nadja; Mc Leod, Roger D.

2007-04-01

388

On-Orbit Absolute Temperature Calibration for CLARREO Using Multiple Phase Change Materials  

Microsoft Academic Search

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

F. A. Best; D. P. Adler; S. D. Ellington; D. J. Thielman; H. E. Revercomb; J. H. Perepezko

2008-01-01

389

On-Orbit Absolute Temperature Calibration Using Multiple Phase Change Materials  

Microsoft Academic Search

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

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

2009-01-01

390

On the Error Sources in Absolute Individual Antenna Calibrations  

NASA Astrophysics Data System (ADS)

The two main methods for antenna calibration currently in use, are anechoic chamber measurements on the one hand and outdoor robot calibration on the other hand. Both techniques differ completely in approach, setup and data processing. Consequently, the error sources for both techniques are totally different as well. Except for the (near field) multi path error, caused by the antenna positioning device, that alters results for both calibration methods. But not necessarily with the same order of magnitude. Literature states a (maximum deviation) repeatability for robot calibration of choke ring antennas of 0.5 mm on L1 and 1 mm on L2 [1]. For anechoic chamber calibration, a value of 1.5 mm on L2 for a resistive ground plane antenna can be found in [2]. Repeatability however masks systematic errors linked with the calibration technique. Hence, comparing an individual calibration obtained with a robot to a calibration of the same antenna in an anechoic chamber, may result in differences that surpass these repeatability thresholds. This was the case at least for all six choke ring antennas studied. The order of magnitude of the differences moreover corresponded well to the values given for a LEIAT504GG in [3]. For some error sources, such as the GNSS receiver measurement noise or the VNA measurement noise, estimates can be obtained from manufacturer specifications in data sheets. For other error sources, such as the finite distance between transmit and receive antenna, or the limited attenuation of reflections on wall absorber, back-of-the-envelope calculations can be made to estimate their order of magnitude. For the error due to (near field) multi path this is harder to do, if not impossible. The more because this strongly depends on the antenna type and its mount. Unfortunately it is, again, this (near field) multi path influence that might void the calibration once the antenna is installed at the station. Hence it can be concluded that at present, due to (near field) multi path errors, both during calibration and later on at the station, absolute sub-millimeter positioning with GPS is not (yet) possible. References [1] G. Wübbena, M. Schmitz, G. Boettcher, C. Schumann, "Absolute GNSS Antenna Calibration with a Robot: Repeatability of Phase Variations, Calibration of GLONASS and Determination of Carrier-to-Noise Pattern", International GNSS Service: Analysis Center workshop, 8-12 May 2006, Darmstadt, Germany. [2] P. Zeimetz, H. Kuhlmann, "On the Accuracy of Absolute GNSS Antenna Calibration and the Conception of a New Anechoic Chamber", FIG Working Week 2008, 14-19 June 2008, Stockholm, Sweden. [3] P. Zeimetz, H. Kuhlmann, L. Wanninger, V. Frevert, S. Schön and K. Strauch, "Ringversuch 2009", 7th GNSS-Antennen-Workshop, 19-20 March 2009, Dresden, Germany.

Aerts, Wim; Baire, Quentin; Bilich, Andria; Bruyninx, Carine; Legrand, Juliette

2013-04-01

391

New experimental methodology, setup and LabView program for accurate absolute thermoelectric power and electrical resistivity measurements between 25 and 1600 K: application to pure copper, platinum, tungsten, and nickel at very high temperatures.  

PubMed

In this paper we describe an experimental setup designed to measure simultaneously and very accurately the resistivity and the absolute thermoelectric power, also called absolute thermopower or absolute Seebeck coefficient, of solid and liquid conductors/semiconductors over a wide range of temperatures (room temperature to 1600 K in present work). A careful analysis of the existing experimental data allowed us to extend the absolute thermoelectric power scale of platinum to the range 0-1800 K with two new polynomial expressions. The experimental device is controlled by a LabView program. A detailed description of the accurate dynamic measurement methodology is given in this paper. We measure the absolute thermoelectric power and the electrical resistivity and deduce with a good accuracy the thermal conductivity using the relations between the three electronic transport coefficients, going beyond the classical Wiedemann-Franz law. We use this experimental setup and methodology to give new very accurate results for pure copper, platinum, and nickel especially at very high temperatures. But resistivity and absolute thermopower measurement can be more than an objective in itself. Resistivity characterizes the bulk of a material while absolute thermoelectric power characterizes the material at the point where the electrical contact is established with a couple of metallic elements (forming a thermocouple). In a forthcoming paper we will show that the measurement of resistivity and absolute thermoelectric power characterizes advantageously the (change of) phase, probably as well as DSC (if not better), since the change of phases can be easily followed during several hours/days at constant temperature. PMID:25273786

Abadlia, L; Gasser, F; Khalouk, K; Mayoufi, M; Gasser, J G

2014-09-01

392

Thermal Insulation  

NASA Technical Reports Server (NTRS)

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.

1984-01-01

393

Application of Mosher's method for absolute configuration assignment and resolution of 2-hydroxypyrrolizidinones.  

PubMed

Derivatization of racemic 2-hydroxypyrrolizidinones with S-(+)-alpha-methoxy-alpha-trifluoromethylphenylacetyl chloride (MTPA-Cl) was successfully used for enantiomer separation and absolute configuration assignment. PMID:15704198

Cordero, Franca M; Pisaneschi, Federica; Salvati, Maria; Valenza, Silvia; Faggi, Cristina; Brandi, Alberto

2005-03-01

394

HST Stellar Standards with 1% Accuracy in Absolute Flux  

E-print Network

Free of any atmospheric contamination, HST provides the best available spectrophotometry from the far-UV to the near-IR for stars as faint as V~16. The HST CALSPEC standard star network is based on 3 standard candles: the hot, pure hydrogen white dwarf (WD) stars G191B2B, GD153, and GD71, which have Hubeny NLTE model flux calculations that require the atomic physics for only one atom. These model flux distributions are normalized to the absolute flux for Vega of 3.46x10^{-9} erg cm^{-2} s^{-1} \\AA^{-1} at 5556\\AA using precise Landolt V band photometry and the V bandpass function corrected for atmospheric transmission by M. Cohen. The 3 primary WD standards provide absolute flux calibrations for FOS, STIS, and NICMOS spectrophotometry from these instruments on the HST. About 32 stellar spectral energy distributions (SEDs) have been constructed with a primary pedigree from the STIS data, which extends from 1150 \\AA for the hot stars to a long wavelength limit of 1\\mu m. NICMOS grism spectrophotometry provides an extension to 1.9\\mu m in the IR for 17 of the HST standards and longward to 2.5\\mu m for a few of the brighter stars. Included among these HST standards are Vega, the Sloan standard BD+17$^{\\circ}$4708, 3 bright solar analog candidates, 3 cool stars of type M or later, and 5 hot WDs. In addition, 4 K giants and 4 main sequence A-stars have NICMOS spectrophotometry from 0.8-2.5\\mu m. The WD fluxes are compared to their modeled SEDs and demonstrate an internal precision of 1-2%, while the A-stars agree with the Cohen IR fluxes to ~2%. Three solar analog candidate stars differ from the solar spectrum by up to 10% in the region of heavy line blanketing from 3000-4000 \\AA and show differences in shape of ~5% in the IR around 1.8\\mu m.

Ralph C. Bohlin

2006-08-31

395

Automatic assignment of absolute configuration from 1D NMR data.  

PubMed

[reaction: see text] Opposite enantiomers exhibit different NMR properties in the presence of an external common chiral element, and a chiral molecule exhibits different NMR properties in the presence of external enantiomeric chiral elements. Automatic prediction of such differences, and comparison with experimental values, leads to the assignment of the absolute configuration. Here two cases are reported, one using a dataset of 80 chiral secondary alcohols esterified with (R)-MTPA and the corresponding (1)H NMR chemical shifts and the other with 94 (13)C NMR chemical shifts of chiral secondary alcohols in two enantiomeric chiral solvents. For the first application, counterpropagation neural networks were trained to predict the sign of the difference between chemical shifts of opposite stereoisomers. The neural networks were trained to process the chirality code of the alcohol as the input, and to give the NMR property as the output. In the second application, similar neural networks were employed, but the property to predict was the difference of chemical shifts in the two enantiomeric solvents. For independent test sets of 20 objects, 100% correct predictions were obtained in both applications concerning the sign of the chemical shifts differences. Additionally, with the second dataset, the difference of chemical shifts in the two enantiomeric solvents was quantitatively predicted, yielding r(2) 0.936 for the test set between the predicted and experimental values. PMID:15760195

Zhang, Qing-You; Carrera, Gonçalo; Gomes, Mário J S; Aires-de-Sousa, João

2005-03-18

396

Absolute interferometric distance measurement using a FM-demodulation technique  

NASA Astrophysics Data System (ADS)

We propose an interferometric method for measuring absolute distances larger than the wavelength. A laser diode is used as a light source. The principle of operation is based on multiple-wavelength interferometry that uses a modulated light source. This method uses the fact that the wavelength of light emitted by the laser diode can be varied by means of the injection current. The modulation of the injection current in combination with the optical heterodyne technique causes a high-frequency phase-modulated detector signal. The phase deviation of the signal is a measure of the optical path difference in the interferometer. By FM demodulation of the detector output with a phase-locked loop demodulator, the optical path difference can be determined directly without the classical ambiguity problem of interferometry. The measuring range in the experiments was limited to 50 mm by the maximum travel range of the used specimen translation stage. Because of the inherent light sensitivity of the method described, the rangefinder can be used for three-dimensional profile measurements on a wide variety of objects, even on diffuse scattering surfaces.

Fischer, Edgar; Dalhoff, Ernst; Heim, Silke; Hofbauer, Ulrich; Tiziani, Hans J.

1995-09-01

397

Absolute interferometric distance measurement using a FM-demodulation technique.  

PubMed

We propose an interferometric method for measuring absolute distances larger than the wavelength. A laser diode is used as a light source. The principle of operation is based on multiple-wavelength interferometry that uses a modulated light source. This method uses the fact that the wavelength of light emitted by the laser diode can be varied by means of the injection current. The modulation of the injection current in combination with the optical heterodyne technique causes a high-frequency phase-modulated detector signal. The phase deviation of the signal is a measure of the optical path difference in the interferometer. By FM demodulation of the detector output with a phase-locked loop demodulator, the optical path difference can be determined directly without the classical ambiguity problem of interferometry. The measuring range in the experiments was limited to 50 mm by the maximum travel range of the used specimen translation stage. Because of the inherent light sensitivity of the method described, the rangefinder can be used for three-dimensional profile measurements on a wide variety of objects, even on diffuse scattering surfaces. PMID:21060384

Fischer, E; Dalhoff, E; Heim, S; Hofbauer, U; Tiziani, H J

1995-09-01

398

An absolute interval scale of order for point patterns.  

PubMed

Human observers readily make judgements about the degree of order in planar arrangements of points (point patterns). Here, based on pairwise ranking of 20 point patterns by degree of order, we have been able to show that judgements of order are highly consistent across individuals and the dimension of order has an interval scale structure spanning roughly 10 just-notable-differences (jnd) between disorder and order. We describe a geometric algorithm that estimates order to an accuracy of half a jnd by quantifying the variability of the size and shape of spaces between points. The algorithm is 70% more accurate than the best available measures. By anchoring the output of the algorithm so that Poisson point processes score on average 0, perfect lattices score 10 and unit steps correspond closely to jnds, we construct an absolute interval scale of order. We demonstrate its utility in biology by using this scale to quantify order during the development of the pattern of bristles on the dorsal thorax of the fruit fly. PMID:25079866

Protonotarios, Emmanouil D; Baum, Buzz; Johnston, Alan; Hunter, Ginger L; Griffin, Lewis D

2014-10-01

399

A new alpha-particle irradiator with absolute dosimetric determination.  

PubMed

A new experimental setup for uniform alpha-particle irradiation of cells in vitro is described. The alpha-particle irradiator is based on a radioactive (212)Pb/(212)Bi source. In the experimental setup proposed, cells are grown directly on a polylysine-coated track-etch material that forms the base of custom-made cell dishes. Alpha-particle irradiation is done through the base of the dish. Immediately prior to irradiation, the cell dish is scanned under a microscope, and images of cells with the corresponding coordinates are saved. After irradiation and after the biological end point under study has been determined, the cell dish is etched to develop alpha-particle tracks in the dish base. A microscope image series of alpha-particle track images is obtained by accurately revisiting every original (preirradiation) cell position in the track-etched dish. The number of alpha-particle traversals of each individual cell is scored by mapping images of alpha-particle tracks onto the images of cells recorded prior to irradiation. The uncertainty of the alpha-particle hit determination is 0.9 microm. The procedure described thus presents a method for radiobiological experiments with absolute, rather than statistical, cell dosimetry. PMID:10630972

Soyland, C; Hassfjell, S P; Steen, H B

2000-01-01

400

ABSOLUTE PROPERTIES OF THE ECLIPSING BINARY STAR BF DRACONIS  

SciTech Connect

BF Dra is now known to be an eccentric double-lined F6+F6 binary star with relatively deep (0.7 mag) partial eclipses. Previous studies of the system are improved with 7494 differential photometric observations from the URSA WebScope and 9700 from the NFO WebScope, 106 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, and 31 accurate radial velocities from the CfA. Very accurate (better than 0.6%) masses and radii are determined from analysis of the two new light curves and four radial velocity curves. Theoretical models match the absolute properties of the stars at an age of about 2.72 Gyr and [Fe/H] = -0.17, and tidal theory correctly confirms that the orbit should still be eccentric. Our observations of BF Dra constrain the convective core overshooting parameter to be larger than about 0.13 H{sub p}. We find, however, that standard tidal theory is unable to match the observed slow rotation rates of the components' surface layers.

Sandberg Lacy, Claud H. [Physics Department, University of Arkansas, Fayetteville, AR 72701 (United States); Torres, Guillermo [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Fekel, Francis C. [Center of Excellence in Information Systems, Tennessee State University, Nashville, TN 37209 (United States); Sabby, Jeffrey A. [Physics Department, Southern Illinois University Edwardsville, Edwardsville, IL 62026 (United States); Claret, Antonio, E-mail: clacy@uark.edu, E-mail: gtorres@cfa.harvard.edu, E-mail: fekel@evans.tsuniv.edu, E-mail: jsabby@siue.edu, E-mail: claret@iaa.es [Instituto de Astrofisica de Andalucia, CSIC, Apdo. Postal 3004, E-18080 Granada (Spain)

2012-06-15

401

Interpretation of the Arcade 2 Absolute Sky Brightness Measurement  

NASA Technical Reports Server (NTRS)

We use absolutely calibrated data between 3 and 90 GHz from the 2006 balloon flight of the ARCADE 2 instrument, along with previous measurements at other frequencies to constrain models of extragalactic emission. Such emission is a combination of the cosmic microwave background (CMB) monopole, Galactic foreground emission, the integrated contribution of radio emission from external galaxies, any spectral distortions present in the CMB, and any other extragalactic source. After removal of estimates of foreground emission from our own Galaxy, and an estimated contribution of external galaxies, we present fits to a combination of the flat-spectrum CMB and potential spectral distortions in the CMB. We find 217 upper limits to CMB spectral distortions of u < 6x10(exp -4) and [Y(sub ff)] < 1x10(exp -4). We also find a significant detection of a residual signal beyond that, which can be explained by the CMB plus the integrated radio emission from galaxies estimated from existing surveys. This residual signal may be due to an underestimated galactic foreground contribution, an unaccounted for contribution of a background of radio sources, or some combination of both. The residual signal is consistent with emission in the form of a power law with amplitUde 18.4 +/- 2.1 K at 0.31 GHz and a spectral index of -2.57 +/- 0.05.

Seiffert, M.; Fixsen, D. J.; Kogut, A.; Levin, S. M.; Limon, M.; Lubin, P. M.; Mirel, P.; Singal, J.; Villela, T.; Wollack, E.; Wuensche, C. A.

2011-01-01

402

On the calculation of absolute macromolecular binding free energies  

PubMed Central

The standard framework for calculating the absolute binding free energy of a macromolecular association reaction A + B ? AB with an association constant KAB is to equate chemical potentials of the species on the left- and right-hand sides of this reaction and evaluate the chemical potentials from theory. This theory involves (usually hidden) assumptions about what constitutes the bound species, AB, and where the contribution of the solvent appears. We present here an alternative derivation that can be traced back to Bjerrum, in which the expectation value of KAB is obtained directly through the statistical mechanical method of evaluating its ensemble (Boltzmann-weighted) average. The generalized Bjerrum approach more clearly delineates: (i) the different contributions to binding; (ii) the origin of the much-discussed and somewhat controversial association entropy term; and (iii) where the solvent contribution appears. This approach also allows approximations required for practical evaluation of the binding constant in complex macromolecular systems, to be introduced in a well defined way. We provide an example, with application to test cases that illustrate a range of binding behavior. PMID:12149474

Luo, Hengbin; Sharp, Kim

2002-01-01

403

Temperature dependence of absolute fluid-state parameters  

NASA Astrophysics Data System (ADS)

The temperature dependence of the vapour and liquid volumes, vv and v1, respectively, of a saturated fluid, 0 < vl ? vc ? vv, d vv/d T < 0 < d vl/d T, and the empirical relation between the volume ratio, vv/ vl, and the evaporation energy, uv - ul, namely ln( vv/ vl) ? ( uv - ul/( RT), are used to derive the temperature dependence of the other state parameters. The pressure, p, is a positive, convex function, increasing as the temperature increases; the chemical potential, ?, is a negative, decreasing, concave function; the entropy, sv, is a positive, decreasing function; the entropy, sl, is a positive, increasing, convex function; the energy, uv, is a positive function; the energy, ul, is a negative, increasing, convex function; the surface tension, ?, is a positive, decreasing function. In particular, one obtains the relations sl ? sc ? sv and ul ? uc ? uv with the limiting values at absolute zero s c/R = 5/2 + limT?0lnV v/v l), slo = 0, uvo = 0, ulo = - ( uv - ul) o and at the critical point s c = overlinecpc/R·v c· dT) c, uc = 0 ( overlinecpc is the specific heat at constant pressure, pc; R is the gas constant).

Elsner, A.

404

Toxicokinetics and absolute oral bioavailability of melamine in broiler chickens.  

PubMed

The objective of this study was to investigate the toxicokinetic characteristics of melamine in broilers due to the limited information available for livestock. Melamine was then administered to broiler chickens at an intravenous (i.v.) or oral (p.o.) dosage of 5.5 mg/kg of body weight, and plasma samples were collected up to 48 h. The concentration of melamine in each plasma sample was analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Melamine was measurable up to 24 h after i.v. and p.o. administration. A one-compartment model was developed to describe the toxicokinetics of melamine in broilers. Following i.v. administration, the values for the elimination half-life (t1/2? ), the volume of distribution (Vd ), and the clearance (CL) were 4.42 ± 1.02 h, 00.52 ± 0.18 L/kg, and 0.08 ± 0.01 L/h/kg, respectively. The absolute oral bioavailability (F) was 95.63 ± 3.54%. The results suggest that most of the administered melamine is favorably absorbed from the alimentary tract and rapidly cleared by the kidneys in broiler chickens. PMID:25066628

Poapolathep, S; Klangkaew, N; Arreesrisom, P; Isariyodom, S; Sugita-Konishi, Y; Kumagai, S; Poapolathep, A

2015-02-01

405

LHD plasma emission measurements by means of absolute XUV photodiodes  

NASA Astrophysics Data System (ADS)

The paper describes the measurements of the LHD plasma total radiation. The 16-channel pinhole type array was based on Absolute XUV photodiodes (AXUVD) (www.ird-inc.com). The detectors have an extended range of photon energies 20 eV \\x81E10 keV, for which sensitivity is high and approximately constant (0.22-0.27 A/W). AXUV diodes are also fast, miniature, easy to use and relatively inexpensive. The plasma radiation profiles were reconstructed using modified Abel inversion procedure. Comparison of the AXUVD data with that obtained from usual metal foil bolometer was made. It shows that on LHD AXUVD cannot be directly used for total radiation power measurements instead of the metal foil bolometer. The reason is the nonlinear spectral response of AXUVD in the low energy part of spectrum (<20 eV). However, for each discharge it is possible to calculate the ratio between the AXUVD and bolometer signals and to use it for AXUVD data correction. Relatively small (<10sinusoidal oscillations of the AXUVD signal were detected during the whole steady state portion of the discharges with the average density higher than 0.5*10**19cm**-3 and He puffing. The frequency changes smoothly during the discharge in the range of 0.5 to 2 kHz.

Kostrioukov, Artem; Peterson, Byron; Sudo, Shigeru; Osakabe, Masaki; Ozaki, Tetuo; Ida, Katsumi

2001-10-01

406

Computational Methodology for Absolute Calibration Curves for Microfluidic Optical Analyses  

PubMed Central

Optical fluorescence and absorption are two of the primary techniques used for analytical microfluidics. We provide a thorough yet tractable method for computing the performance of diverse optical micro-analytical systems. Sample sizes range from nano- to many micro-liters and concentrations from nano- to milli-molar. Equations are provided to trace quantitatively the flow of the fundamental entities, namely photons and electrons, and the conversion of energy from the source, through optical components, samples and spectral-selective components, to the detectors and beyond. The equations permit facile computations of calibration curves that relate the concentrations or numbers of molecules measured to the absolute signals from the system. This methodology provides the basis for both detailed understanding and improved design of microfluidic optical analytical systems. It saves prototype turn-around time, and is much simpler and faster to use than ray tracing programs. Over two thousand spreadsheet computations were performed during this study. We found that some design variations produce higher signal levels and, for constant noise levels, lower minimum detection limits. Improvements of more than a factor of 1,000 were realized. PMID:22163573

Chang, Chia-Pin; Nagel, David J.; Zaghloul, Mona E.

2010-01-01

407

Monochromator-Based Absolute Calibration of a Standard Radiation Thermometer  

NASA Astrophysics Data System (ADS)

Centro Español de Metrología (CEM) is disseminating the International Temperature Scale (ITS-90), at high temperatures, by using the fixed points of Ag and Cu and a standard radiation thermometer. However, the future mise-en-pratique for the definition of the kelvin ( MeP-K) will include the dissemination of the kelvin by primary methods and by indirect approximations capable of exceptionally low uncertainties or increased reliability. Primary radiometry is, at present, able to achieve uncertainties competitive with the ITS-90 above the silver point with one of the possible techniques the calibration for radiance responsivity of an imaging radiometer (radiance method). In order to carry out this calibration, IO-CSIC (Spanish Designated Institute for luminous intensity and luminous flux) has collaborated with CEM, allowing traceability to its cryogenic radiometer. A monochromator integrating sphere-based spectral comparator facility has been used to calibrate one of the CEM standard radiation thermometers. The absolute calibrated standard radiation thermometer has been used to determine the temperatures of the fixed points of Cu, Co-C, Pt-C, and Re-C. The results obtained are 1357.80 K, 1597.10 K, 2011.66 K, and 2747.64 K, respectively, with uncertainties ranging from 0.4 K to 1.1 K.

Mantilla, J. M.; Hernanz, M. L.; Campos, J.; Martín, M. J.; Pons, A.; del Campo, D.

2014-04-01

408

Gravitational acceleration as a cue for absolute size and distance?  

NASA Technical Reports Server (NTRS)

When an object's motion is influenced by gravity, as in the rise and fall of a thrown ball, the vertical component of acceleration is roughly constant at 9.8 m/sec2. In principle, an observer could use this information to estimate the absolute size and distance of the object (Saxberg, 1987a; Watson, Banks, von Hofsten, & Royden, 1992). In five experiments, we examined people's ability to utilize the size and distance information provided by gravitational acceleration. Observers viewed computer simulations of an object rising and falling on a trajectory aligned with the gravitational vector. The simulated objects were balls of different diameters presented across a wide range of simulated distances. Observers were asked to identify the ball that was presented and to estimate its distance. The results showed that observers were much more sensitive to average velocity than to the gravitational acceleration pattern. Likewise, verticality of the motion and visibility of the trajectory's apex had negligible effects on the accuracy of size and distance judgments.

Hecht, H.; Kaiser, M. K.; Banks, M. S.

1996-01-01

409

Absolute measures of the completeness of the fossil record  

NASA Technical Reports Server (NTRS)

Measuring the completeness of the fossil record is essential to understanding evolution over long timescales, particularly when comparing evolutionary patterns among biological groups with different preservational properties. Completeness measures have been presented for various groups based on gaps in the stratigraphic ranges of fossil taxa and on hypothetical lineages implied by estimated evolutionary trees. Here we present and compare quantitative, widely applicable absolute measures of completeness at two taxonomic levels for a broader sample of higher taxa of marine animals than has previously been available. We provide an estimate of the probability of genus preservation per stratigraphic interval, and determine the proportion of living families with some fossil record. The two completeness measures use very different data and calculations. The probability of genus preservation depends almost entirely on the Palaeozoic and Mesozoic records, whereas the proportion of living families with a fossil record is influenced largely by Cenozoic data. These measurements are nonetheless highly correlated, with outliers quite explicable, and we find that completeness is rather high for many animal groups.

Foote, M.; Sepkoski, J. J. Jr; Sepkoski JJ, J. r. (Principal Investigator)

1999-01-01

410

White-dwarf-based evaluation of the GALEX absolute calibration  

NASA Astrophysics Data System (ADS)

This paper describes a revised photometric calibration of the Galaxy Evolution Explorer (GALEX) magnitudes, based on measurements of DA white dwarfs. The photometric magnitudes of white dwarfs measured by GALEX are compared to predicted magnitudes based on independent spectroscopic data (108 stars) and alternately to International Ultraviolet Explorer (IUE) ultraviolet (UV) fluxes of the white dwarfs (218 stars). The results demonstrate a significant non-linear correlation and small offset between archived GALEX fluxes and observed and predicted UV fluxes for our sample. The primary source of non-linearity may be due to detector dead time corrections for brighter stars, but it should be noted that there was a predicted non-linearity in the fainter stars as well. Sample expressions are derived which `correct' observed GALEX magnitudes to an absolute magnitude scale that is linear with respect, and directly related, to the Hubble Space Telescope photometric scale. These corrections should be valid for stars dimmer than magnitudes 9.3 and 10.5 in the near-UV and far-UV, respectively, and brighter than magnitude 17.5 in both.

Camarota, L.; Holberg, J. B.

2014-03-01

411

Method and apparatus for making absolute range measurements  

DOEpatents

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 an object which causes it to be split (hereinafter referred to as a beam splitter''), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beam splitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention. 9 figs.

Allison, S.W.; Cates, M.R.; Key, W.S.; Sanders, A.J.; Earl, D.D.

1999-06-22

412

Absolute phase estimation: adaptive local denoising and global unwrapping.  

PubMed

The paper attacks absolute phase estimation with a two-step approach: the first step applies an adaptive local denoising scheme to the modulo-2 pi noisy phase; the second step applies a robust phase unwrapping algorithm to the denoised modulo-2 pi phase obtained in the first step. The adaptive local modulo-2 pi phase denoising is a new algorithm based on local polynomial approximations. The zero-order and the first-order approximations of the phase are calculated in sliding windows of varying size. The zero-order approximation is used for pointwise adaptive window size selection, whereas the first-order approximation is used to filter the phase in the obtained windows. For phase unwrapping, we apply the recently introduced robust (in the sense of discontinuity preserving) PUMA unwrapping algorithm [IEEE Trans. Image Process.16, 698 (2007)] to the denoised wrapped phase. Simulations give evidence that the proposed algorithm yields state-of-the-art performance, enabling strong noise attenuation while preserving image details. PMID:18846177

Bioucas-Dias, Jose; Katkovnik, Vladimir; Astola, Jaakko; Egiazarian, Karen

2008-10-10

413

Robust absolute magnetometry with organic thin-film devices  

PubMed Central

Magnetic field sensors based on organic thin-film materials have attracted considerable interest in recent years as they can be manufactured at very low cost and on flexible substrates. However, the technological relevance of such magnetoresistive sensors is limited owing to their narrow magnetic field ranges (?30 mT) and the continuous calibration required to compensate temperature fluctuations and material degradation. Conversely, magnetic resonance (MR)-based sensors, which utilize fundamental physical relationships for extremely precise measurements of fields, are usually large and expensive. Here we demonstrate an organic magnetic resonance-based magnetometer, employing spin-dependent electronic transitions in an organic diode, which combines the low-cost thin-film fabrication and integration properties of organic electronics with the precision of a MR-based sensor. We show that the device never requires calibration, operates over large temperature and magnetic field ranges, is robust against materials degradation and allows for absolute sensitivities of <50 nT Hz?1/2. PMID:22692541

Baker, W.J.; Ambal, K.; Waters, D.P.; Baarda, R.; Morishita, H.; van Schooten, K.; McCamey, D.R.; Lupton, J.M.; Boehme, C.

2012-01-01

414

Absolute and relative pitch: Global versus local processing of chords  

PubMed Central

Absolute pitch (AP) is the ability to identify or produce notes without any reference note. An ongoing debate exists regarding the benefits or disadvantages of AP in processing music. One of the main issues in this context is whether the categorical perception of pitch in AP possessors may interfere in processing tasks requiring relative pitch (RP). Previous studies, focusing mainly on melodic and interval perception, have obtained inconsistent results. The aim of the present study was to examine the effect of AP and RP separately, using isolated chords. Seventy-three musicians were categorized into four groups of high and low AP and RP, and were tested on two tasks: identifying chord types (Task 1), and identifying a single note within a chord (Task 2). A main effect of RP on Task 1 and an interaction between AP and RP in reaction times were found. On Task 2 main effects of AP and RP, and an interaction were found, with highest performance in participants with both high AP and RP. Results suggest that AP and RP should be regarded as two different abilities, and that AP may slow down reaction times for tasks requiring global processing. PMID:24855499

Ziv, Naomi; Radin, Shulamit

2014-01-01

415

Absolute pitch exhibits phenotypic and genetic overlap with synesthesia.  

PubMed

Absolute pitch (AP) and synesthesia are two uncommon cognitive traits that reflect increased neuronal connectivity and have been anecdotally reported to occur together in an individual. Here we systematically evaluate the occurrence of synesthesia in a population of 768 subjects with documented AP. Out of these 768 subjects, 151 (20.1%) reported synesthesia, most commonly with color. These self-reports of synesthesia were validated in a subset of 21 study subjects, using an established methodology. We further carried out combined linkage analysis of 53 multiplex families with AP and 36 multiplex families with synesthesia. We observed a peak NPL LOD = 4.68 on chromosome 6q, as well as evidence of linkage on chromosome 2, using a dominant model. These data establish the close phenotypic and genetic relationship between AP and synesthesia. The chromosome 6 linkage region contains 73 genes; several leading candidate genes involved in neurodevelopment were investigated by exon resequencing. However, further studies will be required to definitively establish the identity of the causative gene(s) in the region. PMID:23406871

Gregersen, Peter K; Kowalsky, Elena; Lee, Annette; Baron-Cohen, Simon; Fisher, Simon E; Asher, Julian E; Ballard, David; Freudenberg, Jan; Li, Wentian

2013-05-15

416

Method and apparatus for making absolute range measurements  

DOEpatents

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 an object which causes it to be split (hereinafter referred to as a "beamsplitter"), and then to a target. The beam is reflected from the target onto a screen containing an aperture spaced a known distance from the beamsplitter. The aperture is sized so as to produce a Fresnel diffraction pattern. A portion of the beam travels through the aperture to a detector, spaced a known distance from the screen. The detector detects the central intensity of the beam. The distance from the object which causes the beam to be split to the target can then be calculated based upon the known wavelength, aperture radius, beam intensity, and distance from the detector to the screen. Several apparatus embodiments are disclosed for practicing the method embodiments of the present invention.

Allison, Stephen W. (Knoxville, TN); Cates, Michael R. (Oak Ridge, TN); Key, William S. (Knoxville, TN); Sanders, Alvin J. (Knoxville, TN); Earl, Dennis D. (Knoxville, TN)

1999-01-01

417

Absolute paleointensity from Hawaiian lavas younger than 35 ka  

USGS Publications Warehouse

Paleointensity studies have been conducted in air and in argon atmosphere on nine lava flows with radiocarbon ages distributed between 3.3 and 28.2 ka from the Mauna Loa volcano in the big island of Hawaii. Determinations of paleointensity obtained at eight sites depict the same overall pattern as the previous results for the same period in Hawaii, although the overall average field intensity appears to be lower. Since the present results were determined at higher temperatures than in the previous studies, this discrepancy raises questions regarding the selection of low versus high-temperature segments that are usually made for absolute paleointensity. The virtual dipole moments are similar to those displayed by the worldwide data set obtained from dated lava flows. When averaged within finite time intervals, the worldwide values match nicely the variations of the Sint-200 synthetic record of relative paleointensity and confirm the overall decrease of the dipole field intensity during most of this period. The convergence between the existing records at Hawaii and the rest of the world does not favour the presence of persistent strong non-dipole components beneath Hawaii for this period.

Valet, J.-P.; Tric, E.; Herrero-Bervera, E.; Meynadier, L.; Lockwood, J.P.

1998-01-01

418

Thermal unobtainiums? The perfect thermal conductor and  

E-print Network

Thermal unobtainiums? The perfect thermal conductor and the perfect thermal insulator David G condensate of magnons #12;Outline--toward perfect thermal insulators · Einstein and minimum thermal Gratefully acknowledge support from ONR and AFOSR #12;Outline--toward perfect thermal conductors

Braun, Paul

419

Absolutely Continuous Convolutions of Singular Measures and an Application to the Square Fibonacci Hamiltonian  

E-print Network

We prove for the square Fibonacci Hamiltonian that the density of states measure is absolutely continuous for almost all pairs of small coupling constants. This is obtained from a new result we establish about the absolute continuity of convolutions of measures arising in hyperbolic dynamics with exact-dimensional measures.

David Damanik; Anton Gorodetski; Boris Solomyak

2014-08-28

420

RESEARCH ARTICLE Absolute calibration of Analog Detectors using Stimulated Parametric Down Conversion  

Microsoft Academic Search

() Spontaneous parametric down conversion has been largely exploited as a tool for absolute calibration of photon counting detectors, photomultiplier tubes or avalanche photodiodes working in Geiger regime. In this work we investigate the extension of this technique from very low photon flux of photon counting regime to the absolute calibration of analog photodetectors at higher photon flux. Moving toward

G. Brida; M. Chekhova; M. Genovese; M. L. Rastello; I. Ruo-Berchera

421

Absolute Vacuum Ultraviolet Oscillator Strengths in Co II and the Interstellar Cobalt Abundance  

Microsoft Academic Search

We report the first laboratory measurements of 10 absolute oscillator strengths (f-values) for vacuum ultraviolet lines of Co II. The oscillator strengths are measured with the High Sensitivity Absorption Spectroscopy Experiment at the University of Wisconsin. The measurements serve as a test of theoretical work on Co II f-values and set an absolute scale for relative oscillator strengths from spectra

K. L. Mullman; J. E. Lawler; J. Zsargó; S. R. Federman

1998-01-01

422

Absolute velocity of North America during the Mesozoic from paleomagnetic data  

E-print Network

Absolute velocity of North America during the Mesozoic from paleomagnetic data Myrl E. Beck Jr paleomagnetic data to map Mesozoic absolute motion of North America, using paleomagnetic Euler poles (PEP the apparent polar wander (APW) path constructed using poles from southwestern North America

Housen, Bernie

423

Absolute testing of the reference surface of a Fizeau interferometer through even\\/odd decompositions  

Microsoft Academic Search

Absolute testing of spherical surfaces is a technological necessity because of increased accuracy requirements. In a Fizeau setup, the main part of the interferometer deviations thereby comes from the reference surface. We demonstrate the validity of an absolute testing procedure for the reference surface that has been proposed earlier. The procedure relies on the decomposition of the surface deviations into

R. Schreiner; J. Schwider; N. Lindlein; K. Mantel

2008-01-01

424

The absolute zero point method to improve the positional accuracy for PDS microdensitometer coordinate system - hardware  

Microsoft Academic Search

The logic circuit design of the absolute zero signal for PDS coordinate system is introduced. The key point is to make use of the phase relation between the zero signal and B-phase signal on the linear optical encoder. A logic circuit is designed to extract the absolute zero signal with a high repeatability of less than 1 mum.

Hui Fang; You-Yi Zhang

1993-01-01

425

Using the image acquisition capabilities of the optical mouse sensor to build an absolute rotary encoder  

Microsoft Academic Search

In this paper, the optical mouse sensor is proposed as the main sensor of an absolute rotary encoder. The image acquired by the optical sensor is used to read a positioning binary code printed on an internal rotary surface to obtain the absolute rotary position. The two-dimensional image matrix acquisition is more robust than the single reading point approach used

M. Tresanchez; T. Pallejà; M. Teixidó; J. Palacín

2010-01-01

426

Analysis of Thin Beams and Cables Using the Absolute Nodal Coordinate Formulation  

Microsoft Academic Search

The purpose of this paper is to present formulations for beam elements based on the absolute nodal co-ordinate formulation that can be effectively and efficiently used in the case of thin structural applications. The numerically stiff behaviour resulting from shear terms in existing absolute nodal co-ordinate formulation beam elements that employ the continuum mechanics approach to formulate the elastic forces

Johannes Gerstmayr; Ahmed A. Shabana

2006-01-01

427

Absolute configuration and conformational analysis of sesquiterpene lactone glycoside studied by vibrational circular dichroism spectroscopy  

NASA Astrophysics Data System (ADS)

The absolute configuration of the guaiane-type sesquiterpene lactone 8-epiisolippidiol-3- O-?- D-glucopyranoside, isolated from plants of the genus Crepis, and the predominant solution-state conformation in CD 3OD were determined by comparison of experimental and calculated VCD spectra. It has been found that the reported stereostructure of the compound corresponds to its absolute configuration.

Michalski, Oskar; Kisiel, Wanda; Michalska, Klaudia; Setnicka, Vladimir; Urbanova, Marie

2007-12-01

428

Absolute dune ages and implications for the time of formation of gullies in Nirgal Vallis, Mars  

Microsoft Academic Search

Transverse dunes cover the valley floor of Nirgal Vallis, a 670 km long valley network at 318°E and 29°S. The dunes are superposed by small undeformed impact craters, which implies that the dunes are inactive under present atmospheric conditions. The last active phase of dune movement (absolute age) can be determined by crater size frequency distributions. The derived absolute ages

D. Reiss; S. van Gasselt; G. Neukum; R. Jaumann

2004-01-01

429

Basque spatial cases and the ergative-absolutive synchretismi Ricardo Etxepare (IKER-UMR5478, CNRS)  

E-print Network

and absolutive arguments in some of the dialects of Basque. This synchretism, which can be found in western and central dialects of Basque, resolves in favour of absolutive marking, and has been taken to be the product connections emerging from the analysis are, I think, relatively clear, their materialization in terms

Paris-Sud XI, Université de

430

Improvements of the Maximum Intersection Method for 3D Absolute Earthquake Locations  

E-print Network

Improvements of the Maximum Intersection Method for 3D Absolute Earthquake Locations by Thomas of the maximum intersection (MAXI) method in which absolute earthquake location is defined by the maximum a technique that minimizes travel-time residues. To conclude, we apply the MAXI method to locate earthquakes

Demouchy, Sylvie

431

Absolute quantum photoyield of ion damaged diamond surfaces A. Laikhtman and A. Hoffmana)  

E-print Network

-9 INTRODUCTION It is very difficult to prepare synthetic diamond films free of defects and impuritiesAbsolute quantum photoyield of ion damaged diamond surfaces A. Laikhtman and A. Hoffmana We report on the absolute quantum photoyield QPY measurements from defective diamond surfaces

432

J. Phys. D: Appl. Phys. 29 (1996) 10741079. Printed in the UK Measurement of the absolute  

E-print Network

abberated above 40 mW of pump laser power. This low value for the upper limit of pump power is due and Tam 1981). Quite recently we measured absolute quantum yields of fluorescence emission from laser dyesJ. Phys. D: Appl. Phys. 29 (1996) 1074­1079. Printed in the UK Measurement of the absolute

Harilal, S. S.

433

A New Approach For Absolute Temperature Calibration: Application to the CLARREO Mission  

Microsoft Academic Search

A novel scheme to provide on-orbit absolute calibration of blackbody temperature sensors (on-demand) has been demonstrated using a copy of the engineering model version of a space flight hardware blackbody design (GIFTS). The scheme uses the phase change signature of reference materials to assign an absolute temperatures scale to the blackbody sensors over a large temperature range. Uncertainties of better

F. A. Best; D. P. Adler; S. D. Ellington; D. J. Thielman; H. E. Revercomb; J. G. Anderson

2007-01-01

434

On-orbit absolute calibration of temperature with application to the CLARREO mission  

Microsoft Academic Search

NASA's anticipated plan for a mission dedicated to climate (CLARREO) will hinge upon the ability to fly absolute standards that can provide the basis to meet stringent requirements on measurement accuracy For example, instrumentation designed to measure spectrally resolved infrared radiances will require high-emissivity calibration blackbodies having absolute temperature uncertainties of better than 0.045 K (3 sigma). A novel scheme

Fred A. Best; Douglas P. Adler; Scott D. Ellington; Donald J. Thielman; Henry E. Revercomb

2008-01-01

435

Absolute magnitudes for late-type dwarf stars for Sloan photometry  

E-print Network

We present a new formula for absolute magnitude determination for late-type dwarf stars as a function of (g-r) and (r-i) for Sloan photometry. The absolute magnitudes estimated by this approach are brighter than those estimated by colour-magnitude diagrams, and they reduce the luminosity function rather close to the luminosity function of Hipparcos.

S. Bilir; S. Karaali; S. Tuncel

2005-03-18

436

Free volume hypothetical scanning molecular dynamics method for the absolute free energy of liquids  

E-print Network

Free volume hypothetical scanning molecular dynamics method for the absolute free energy of liquids for calculating the absolute entropy, S, and free energy, F, by analyzing Boltzmann samples obtained by Monte energy evaluation is a central issue in atomistic modeling.1­5 When the free energy is known, equilibrium

Meirovitch, Hagai

437

An Absolute Radius Scale for Saturn's Rings from Cassini Occultations  

NASA Astrophysics Data System (ADS)

Abstract (2,250 Maximum Characters): The Cassini mission has provided a remarkable opportunity to investigate the structure and dynamics of the Saturn ring system at the sub-km radial scale, using hundreds of individual stellar and radio occultations from the UVIS, VIMS, and RSS instruments. From precise measurements of ring and gap edges, we have been able to determine the orbital characteristics of over one hundred features in the rings. A crucial step in the orbital determination is the establishment of a highly accurate radius scale for the rings. This is compounded by uncertainties in the positions of the occulted stars, km-scale trajectory errors in the spacecraft location, and inexact knowledge of the direction and precession rate of Saturn’s pole. We have taken an iterative approach in which we identify a set of 30 or so putative circular, equatorial features, solve for along-track trajectory errors for each occultation, and use this best-fitting orbital solution to establish the reference system for determination of the orbits of non-circular ring features. Using thousands of individual measurements of rings in the Cassini data, we have determined an absolute radius scale for each contributing occultation with an accuracy of about 200 m for the C and B rings and the Cassini Division. This enables us to detect and measure very small dynamical effects such as weak normal modes in ring edges, and to determine the phases of density waves, including very short wavelength outer Lindblad resonances in the C ring, as reported at this meeting. We calculate the sensitivity of the radius scale to the assumed pole direction and precession rate. Ultimately, we will combine these results with Voyager, HST, and pre-Cassini Earth-based occultation measurements to refine our knowledge of Saturn’s pole direction and precession.

McGhee, Colleen; French, R. G.; Jacobson, R. A.; Nicholson, P. D.; Colwell, J. E.; Marouf, E. A.; Lonergan, K.; Sepersky, T.

2013-05-01

438

Absolute Measurement Of EUV Radiation From An Undulator  

SciTech Connect

Driven by the needs for microlithography, powerful sources for extreme ultraviolet (EUV) radiation at wavelengths around 13 nm are currently under development. For absolute photon flux measurements of highly intense and extremely pulsed radiation in the VUV and EUV spectral range, a detector system based on the photoionization of rare gases has been developed. Due to its extended dynamic range, the device can be calibrated with spectrally dispersed synchrotron radiation at low photon intensities, but applied for high power sources like recently at the VUV-FEL of the TESLA test facility at DESY. The detector is free of degradation and almost transparent, and therefore suitable for intensity monitoring. Here we describe the application of the detector for flux measurements at a beamline for undispersed, deflected undulator radiation in the PTB Radiometry Laboratory at the electron storage ring BESSY II. This beamline is used for development and lifetime testing of components for EUV lithography, where accurate determination of the incident radiant power is needed, e.g. for exposure dose control. Taking advantage of the characteristic photoionization cross sections for different rare gases in the soft x-ray wavelength range, contributions of higher undulator harmonics could be determined and suppressed for EUV (13 nm) power measurements. While in normal operation the BESSY II radiation can be seen as quasi-continuous (500 MHz repetition rate), in single-bunch operation mode (1.25 MHz) measurements of the power for single EUV pulses have been performed. This demonstrates the capability of the gas detector for a broad range of applications with pulsed EUV sources.

Gottwald, A.; Klein, R.; Mueller, R.; Richter, M.; Sorokin, A.A.; Ulm, G. [Physikalisch-Technische Bundesanstalt, Abbestr. 2-12, 10587 Berlin (Germany)

2004-05-12

439

Absolute parameters of young stars - I. U Ophiuci  

NASA Astrophysics Data System (ADS)

We have carried out an investigation of the early-type multiple star U Oph. We have used new high-resolution spectroscopy with the High Efficiency and Resolution Canterbury University Large Echelle Spectrograph (HERCULES) and 1-m McLellan Telescope of the University of Canterbury at Mt John University Observatory and literature-sourced optical and ultraviolet photometry. We applied the local reduction package [HERCULES Reduction Software Package (HRSP)] and other software to the spectroscopic data to find radial velocities. Information limit optimization techniques (ILOT) utilizing physically realistic fitting functions were applied to these data to yield new sets of absolute parameters: M1 = 5.13, M2 = 4.56 (+/-2 per cent); R1 = 3.41, R2 = 3.08 (+/-1 per cent); for the early-type eclipsing binary that dominates the system. We have combined times-of-minima photometry with other data for the triple system that makes up ADS 10428A, utilizing the wide orbit of Wolf et al. as well as HIPPARCOS astrometry of U Oph. ILOT techniques applied to the astrometric orbit yield a mass of the third star as 0.83Msolar. We estimate an age of the system of around 30-40Myr, from the isochrones of Bertelli, results given by Vaz, Andersen & Claret, as well as our own tests with an updated version of Paczy?ski's stellar modelling code. This age and other details are consistent with a possible origin in Gould's Belt. Such information for this, and comparable young multiple star systems, may help to clarify general properties of star formation and the subtle interactions of stars and their environment.

Budding, E.; Inlek, G.; Demircan, O.

2009-02-01

440

Absolute Pitch: Effects of Timbre on Note-Naming Ability  

PubMed Central

Background Absolute pitch (AP) is the ability to identify or produce isolated musical tones. It is evident primarily among individuals who started music lessons in early childhood. Because AP requires memory for specific pitches as well as learned associations with verbal labels (i.e., note names), it represents a unique opportunity to study interactions in memory between linguistic and nonlinguistic information. One untested hypothesis is that the pitch of voices may be difficult for AP possessors to identify. A musician's first instrument may also affect performance and extend the sensitive period for acquiring accurate AP. Methods/Principal Findings A large sample of AP possessors was recruited on-line. Participants were required to identity test tones presented in four different timbres: piano, pure tone, natural (sung) voice, and synthesized voice. Note-naming accuracy was better for non-vocal (piano and pure tones) than for vocal (natural and synthesized voices) test tones. This difference could not be attributed solely to vibrato (pitch variation), which was more pronounced in the natural voice than in the synthesized voice. Although starting music lessons by age 7 was associated with enhanced note-naming accuracy, equivalent abilities were evident among listeners who started music lessons on piano at a later age. Conclusions/Significance Because the human voice is inextricably linked to language and meaning, it may be processed automatically by voice-specific mechanisms that interfere with note naming among AP possessors. Lessons on piano or other fixed-pitch instruments appear to enhance AP abilities and to extend the sensitive period for exposure to music in order to develop accurate AP. PMID:21085598

Vanzella, Patrícia; Schellenberg, E. Glenn

2010-01-01

441

PHASES: A Project to Perform Absolute Spectrophotometry from Space  

NASA Astrophysics Data System (ADS)

This paper presents the current status of the opto-mechanical design of PHASES (Planet Hunting and AsteroSeismology Explorer Spectrophotometer), which is a project to develop a space-borne telescope to obtain absolute flux calibrated spectra of bright stars. The science payload is intended to be housed in a micro-satellite launched into a low-earth Sun-synchronous orbit with an inclination to the equator of 98.7° and a local time ascending node LTAN of 6:00 AM. PHASES will be able to measure micromagnitude photometric variations due to stellar oscillations/activity and planet/moon transits. It consists of a 20 cm aperture modified Baker telescope feeding two detectors: the tracking detector provides the fine telescope guidance system with a required pointing stability of 0.2?, and the science detector performs spectrophotometry in the wavelength range 370-960 nm with a resolving power between 200 and 900. The spectrograph is designed to provide 1% RMS flux calibrated spectra with signal-to-noise ratios > 100 for stars with V < 10 in short integration times. Our strategy to calibrate the system using A type stars is explained. From comparison with model atmospheres it would be possible to determine the stellar angular diameters with an uncertainty of approximately 0.5%. In the case of a star hosting a transiting planet it would be possible to derive its light curve, and then the planet to stellar radius ratio. Bright stars have high precision Hipparcos parallaxes and the expected level of accuracy for their fluxes will be propagated to the stellar radii, and more significantly to the planetary radii. The scientific drivers for PHASES give rise to some design challenges, which are particularly related to the opto-mechanics for extreme environmental conditions. The optical design has been developed with the primary goal of avoiding stray light reaching the science detector. Three different proposals for the opto-mechanical design are under investigation.

del Burgo, C.; Vather, D.; Allende Prieto, C.; Murphy, N.

2013-04-01

442

Absolute Measurements Of Methane On Mars: The Current Status.  

NASA Astrophysics Data System (ADS)

Our study of methane on Mars now extends over three Mars years, sampling a wide range of seasons with significant spatial coverage. Three spectrometer-telescope combinations were used. With the spectrometer slit oriented North-South on the planet, we obtain simultaneous spectra at latitudes along the central meridian. Successive longitudes are sampled as the planet rotates, and the combination then permits partial mapping of the planet. We earlier reported differential detections of methane and water on Mars. Here, we present absolute extractions of methane, based on improved analytical procedures developed since 2005. We now identify and correct instrumental effects such as variations in resolving power along the slit, second-order optical fringe removal, and correction of (minor) internal scattered light. We synthesize the fully-resolved terrestrial transmittance spectrum, convolve it to the instrumental resolution, and subtract it from the measured Mars-Earth spectrum. Fraunhofer lines are removed from the residual Mars spectra along with spectral lines of water and of (newly identified by us) carbon dioxide isotopomers. The residuals are then inspected for signatures of methane and other possible trace constituents such as HDO and H2O (Villanueva et al., this Conference). On certain dates, the residual spectra display spectral lines at the Doppler-shifted positions expected for methane on Mars. The positive indications favor certain seasons (e.g., Ls = 121° & 155°) and locations. Mixing ratios derived from those residuals (up to 60 ppb) greatly exceed upper limits obtained at other seasons (e.g., < 3ppb at Ls = 17°) these variations could be consistent with episodic release. The CH4 spatial extent requires transport over large distances (coupled with eddy diffusion), and destruction lifetimes of order one year. Details will be presented and implications will be discussed. This work was supported by NASA's Astrobiology, Planetary Astronomy, and Postdoctoral Programs, and NSF's RUI Program.

Mumma, Michael J.; Villanueva, G. L.; Novak, R. E.; Hewagama, T.; Bonev, B. P.; DiSanti, M. A.; Smith, M. D.

2008-09-01

443

Feasibility of absolute cerebral tissue oxygen saturation during cardiopulmonary resuscitation  

PubMed Central

Introduction Current monitoring during cardiopulmonary resuscitation (CPR) is limited to clinical observation of consciousness, breathing pattern and presence of a pulse. At the same time, the adequacy of cerebral oxygenation during CPR is critical for neurological outcome and thus survival. Cerebral oximetry, based on near-infrared spectroscopy (NIRS), provides a measure of brain oxygen saturation. Therefore, we examined the feasibility of using NIRS during CPR. Methods Recent technologies (FORE-SIGHT™ and EQUANOX™) enable the monitoring of absolute cerebral tissue oxygen saturation (SctO2) values without the need for pre-calibration. We tested both FORE-SIGHT™ (five patients) and EQUANOX Advance™ (nine patients) technologies in the in-hospital as well as the out-of-hospital CPR setting. In this observational study, values were not utilized in any treatment protocol or therapeutic decision. An independent t-test was used for statistical analysis. Results Our data demonstrate the feasibility of both technologies to measure cerebral oxygen saturation during CPR. With the continuous, pulseless near-infrared wave analysis of both FORE-SIGHT™ and EQUANOX™ technology, we obtained SctO2 values in the absence of spontaneous circulation. Both technologies were able to assess the efficacy of CPR efforts: improved resuscitation efforts (improved quality of chest compressions with switch of caregivers) resulted in higher SctO2 values. Until now, the ability of CPR to provide adequate tissue oxygenation was difficult to quantify or to assess clinically due to a lack of specific technology. With both technologies, any change in hemodynamics (for example, ventricular fibrillation) results in a reciprocal change in SctO2. In some patients, a sudden drop in SctO2 was the first warning sign of reoccurring ventricular fibrillation. Conclusions Both the FORE-SIGHT™ and EQUANOX™ technology allow non-invasive monitoring of the cerebral oxygen saturation during CPR. Moreover, changes in SctO2 values might be used to monitor the efficacy of CPR efforts. PMID:23448653

2013-01-01

444

Eigenvalues, separability and absolute separability of two-qubit states  

NASA Astrophysics Data System (ADS)

Substantial progress has recently been reported in the determination of the Hilbert-Schmidt (HS) separability probabilities for two-qubit and qubit-qutrit (real, complex and quaternionic) systems. An important theoretical concept employed has been that of a separability function. It appears that if one could analogously obtain separability functions parameterized by the eigenvalues of the density matrices in question-rather than the diagonal entries, as originally used-comparable progress could be achieved in obtaining separability probabilities based on the broad, interesting class of monotone metrics (the Bures, being its most prominent [minimal] member). Though large-scale numerical estimations of such eigenvalue-parameterized functions have been undertaken, it seems desirable also to study them in lower-dimensional specialized scenarios in which they can be exactly obtained. In this regard, we employ an Euler-angle parameterization of SO(4) derived by S. Cacciatori (reported in an Appendix)—in the manner of the SU(4)-density-matrix parameterization of Tilma, Byrd and Sudarshan. We are, thus, able to find simple exact separability (inverse-sine-like) functions for two real two-qubit (rebit) systems, both having three free eigenvalues and one free Euler angle. We also employ the important Verstraete-Audenaert-de Moor bound to obtain exact HS probabilities that a generic two-qubit state is absolutely separable (that is, cannot be entangled by unitary transformations). In this regard, we make copious use of trigonometric identities involving the tetrahedral dihedral angle ?=cos-1({1}/{3}).

Slater, Paul B.

2009-01-01

445

Usage tests of oak moss absolutes containing high and low levels of atranol and chloroatranol.  

PubMed

Atranol and chloroatranol are strong contact allergens in oak moss absolute, a lichen extract used in perfumery. Fifteen subjects with contact allergy to oak moss absolute underwent a repeated open application test (ROAT) using solutions of an untreated oak moss absolute (sample A) and an oak moss absolute with reduced content of atranol and chloroatranol (sample B). All subjects were in addition patch-tested with serial dilutions of samples A and B. Statistically significantly more subjects reacted to sample A than to sample B in the patch tests. No corresponding difference was observed in the ROAT, though there was a significant difference in the time required to elicit a positive reaction. Still, the ROAT indicates that the use of a cosmetic product containing oak moss absolute with reduced levels of atranol and chloroatranol is capable of eliciting an allergic reaction in previously sensitised individuals. PMID:24287679

Mowitz, Martin; Svedman, Cecilia; Zimerson, Erik; Bruze, Magnus

2014-07-01

446

Single-track absolute position encoding method based on spatial frequency of stripes  

NASA Astrophysics Data System (ADS)

A new method of single-track absolute position encoding based on spatial frequency of stripes is proposed. Instead of using pseudorandom-sequence arranged stripes as in conventional situations, this kind of encoding method stores the location information in the frequency space of the stripes, which means the spatial frequency of stripes varies with position and indicates position. This encoding method has a strong fault-tolerant capability with single-stripe detecting errors. The method can be applied to absolute linear encoders, absolute photoelectric angle encoders or two-dimensional absolute linear encoders. The measuring apparatus includes a CCD image sensor and a microscope system, and the method of decoding this frequency code is based on FFT algorithm. This method should be highly interesting for practical applications as an absolute position encoding method.

Xiang, Xiansong; Lu, Yancong; Wei, Chunlong; Zhou, Changhe

2014-11-01

447

Observed and projected changes in absolute temperature records across the contiguous United States  

NASA Astrophysics Data System (ADS)

in the extent of absolute, all-time, daily temperature records across the contiguous United States were examined using observations and climate model simulations. Observations from station data and reanalysis from 1980 to 2013 show increased extent of absolute highest temperature records and decreased extent of absolute lowest temperature records. Conversely, station data from 1920 to 2013 showed decreased extent of absolute highest records with nearly half of such records occurring in the 1930s during exceptional widespread drought. Simulated changes in the extent of absolute temperature records from climate model experiments were in general agreement with observed changes for recent decades. However, fewer lowest temperature records and highest temperature records were observed since 2000 than simulated by most models. Climate models project a continued increase in the occurrence of highest temperature records and decline in lowest temperature records through the mid-21st century.

Abatzoglou, John T.; Barbero, Renaud

2014-09-01

448

The thermal conductivity of benzene and toluene  

SciTech Connect

The thermal conductivity of liquid toluene and benzene was measured in the temperature range 298 to 370 K, near the saturation line, using an absolute transient hot-wire technique. The measurements were made in a modified version of an existing instrument, equipped with a new automatic Wheatstone bridge, computer controlled. The bridge measures the time that the resistance of a 7-{mu}m-diameter platinum wire takes to reach predetermined values, programmed by the computer. The computer can generate up to 1,024 analog voltages, via a 12-bit D/A converter. The accuracy of the measurements with this new arrangement was assessed by measuring the thermal conductivity of a primary standard, toluene, at several temperatures and was found to be of the order of 0.3%. Benzene was chosen because it is under study as a possible secondary standard for liquid thermal conductivity by the Subcommittee on Transport Properties of IUPAC.

Ramires, M.L.V.; Vieira dos Santos, F.J.; Mardolcar, U.V.; Nieto de Castro, C.A. (Instituto Superior Tecnico, Lisbon (Portugal))

1989-09-01

449

Thermal Conductivity of Subcooled Liquid Hydrogen  

NASA Astrophysics Data System (ADS)

Here we present thermal conductivity measurements of subcooled equilibrium liquid hydrogen in the temperature range from 15 to 23 K and under pressures up to 1 MPa. The measurements have been done in a horizontal, guarded, flat-plates calorimeter. One dimensional heat transfer between the hot and the cold plates of the calorimeter is achieved by the placement of two thermal guards. Capacitance measurement between the calorimeter plates gives a precise and accurate value for the gap. A two-stage Gifford-McMahon cryocooler provides the cooling power to the calorimeter. The absolute temperatures are monitored using ruthenium oxide temperature sensors calibrated against the saturated vapor-pressure line of equilibrium hydrogen. Results reported in this paper are compared to existing data and an analytical model. Knowledge of the density dependence to the thermal conductivity is expected to be useful for subcooled hydrogen transport processes.

Charignon, T.; Celik, D.; Hemmati, A.; Van Sciver, S. W.

2008-03-01

450

Analyzing absolute paleointensity determinations: Acceptance criteria and the software ThellierTool4.0  

NASA Astrophysics Data System (ADS)

The ThellierTool4.0 is an intuitive and easy-to-use software which provides the possibility to analyze a wide range of different modifications of the Thellier absolute paleointensity experiment (available at http://earthref.org/tools/). Besides the Arai plot for paleointensity determination, orthogonal projections of the direction, decay of NRM during thermal demagnetization, and additional plots regarding alteration and multidomain checks enable the user to visualize the quality of individual determinations. Experimental checks for magnetomineralogical changes, either in-field or zero-field pTRM* checks, are evaluated regarding their differences to the corresponding pTRM* acquisition in two most commonly used ways. Furthermore, a measure for the cumulative alteration differences beginning at room temperature is calculated, and the possibility to correct for magnetomineralogical changes is provided. Two different experimental methods to check for multidomain bias are supported and analyzed by the software. Intensity differences recorded by pTRM*-tail checks are calculated. Accounting for the directional difference between applied laboratory field and magnetization of the sample, the effective pTRM*-tail is determined, and thus failures of Thellier's law of independence are monitored. Failures of the law of additivity, experimentally observed by additivity checks, are also evaluated by the software. The vectorial character of individual measurements is fully considered for all calculations. Uniform selection criteria for acceptance and rejection of determinations can be applied, and a set of such criteria with emphasis on minimal bias due to alteration, multidomain remanence, and analysis/experimental inaccuracies is suggested.

Leonhardt, R.; Heunemann, C.; KráSa, D.

2004-12-01

451

A New Absolute Plate Motion Model for Africa  

NASA Astrophysics Data System (ADS)

The India-Eurasia collision, a change in relative plate motion between Australia and Antarctica, and the coeval ages of the Hawaiian Emperor Bend (HEB) and Louisville Bend of ~Chron 22-21 all provide convincing evidence of a global tectonic plate reorganization at ~50 Ma. Yet if it were a truly global event, then there should be a contemporaneous change in Africa absolute plate motion (APM) reflected by physical evidence somewhere on the Africa plate. This evidence might be visible in the Reunion-Mascarene bend, which exhibits many HEB-like features such as a large angular change close to ~50 Ma. Recently, the Reunion hotpot trail has been interpreted as a continental feature with incidental hotspot volcanism. Here we propose the alternative hypothesis that the northern portion of the chain between Saya de Malha and the Seychelles (Mascarene Plateau) formed as the Reunion hotspot was situated on the Carlsberg Ridge, contemporaneously forming the Chagos-Laccadive Ridge on the India plate. We have created a 4-stage model that explores how a simple APM model fitting the Mascarene Plateau can also satisfy the age progressions and geometry of other hotspot trails on the Africa plate. This type of model could explain the apparent bifurcation of the Tristan hotspot chain, the age reversals seen along the Walvis Ridge and the diffuse nature of the St. Helena chain. To test this hypothesis we have made a new African APM model that goes back to ~80 Ma using a modified version of the Hybrid Polygonal Finite Rotation Method. This method uses seamount chains and their associated hotspots as geometric constraints for the model, and seamount age dates to determine its motion through time. The positions of the hotspots can be moved to get the best fit for the model and to explore the possibility that the ~50 Ma bend in the Reunion-Mascarene chain reflects Africa plate motion. We will examine how well this model can predict the key features reflecting Africa plate motion and contrast its predictions with other proposed models.

Maher, S. M.; Wessel, P.; Müller, D.; Harada, Y.

2013-12-01

452

Absolute Magnitudes of Pan-STARRS PS1 Asteroids  

NASA Astrophysics Data System (ADS)

Absolute magnitude (H) of an asteroid is a fundamental parameter describing the size and the apparent brightness of the body. Because of its surface shape, properties and changing illumination, the brightness changes with the geometry and is described by the phase function governed by the slope parameter (G). Although many years have been spent on detailed observations of individual asteroids to provide H and G, vast majority of minor planets have H based on assumed G and due to the input photometry from multiple sources the errors of these values are unknown. We compute H of ~ 180 000 and G of few thousands asteroids observed with the Pan-STARRS PS1 telescope in well defined photometric systems. The mean photometric error is 0.04 mag. Because on average there are only 7 detections per asteroid in our sample, we employed a Monte Carlo (MC) technique to generate clones simulating all possible rotation periods, amplitudes and colors of detected asteroids. Known asteroid colors were taken from the SDSS database. We used debiased spin and amplitude distributions dependent on size, spectral class distributions of asteroids dependent on semi-major axis and starting values of G from previous works. H and G (G12 respectively) were derived by phase functions by Bowell et al. (1989) and Muinonen et al. (2010). We confirmed that there is a positive systematic offset between H based on PS1 asteroids and Minor Planet Center database up to -0.3 mag peaking at 14. Similar offset was first mentioned in the analysis of SDSS asteroids and was believed to be solved by weighting and normalizing magnitudes by observatory codes. MC shows that there is only a negligible difference between Bowell's and Muinonen's solution of H. However, Muinonen's phase function provides smaller errors on H. We also derived G and G12 for thousands of asteroids. For known spectral classes, slope parameters agree with the previous work in general, however, the standard deviation of G in our sample is twice as larger, most likely due to sparse phase curve sampling. In the near future we plan to complete the H and G determination for all PS1 asteroids (500,000) and publish H and G values online. This work was supported by NASA grant No. NNX12AR65G.

Veres, Peter; Jedicke, R.; Fitzsimmons, A.; Denneau, L.; Wainscoat, R.; Bolin, B.; PS1SC Collaboration

2013-10-01

453

THERMAL HYDRAULICS KEYWORDS: thermal hydraulics,  

E-print Network

-fluid modeling of nuclear reactor systems. Thermal-hydraulic analysis codes such as RELAP5-3D ~Ref. 1! and FLICA regions of the system. In fact, the CFD code FLUENT has previously been coupled to RELAP5-3D ~Refs. 3

Smith, Barton L.

454

Absolute versus temporal anomaly and percent of saturation soil moisture spatial variability for six networks worldwide  

NASA Astrophysics Data System (ADS)

analysis of the spatial-temporal variability of soil moisture can be carried out considering the absolute (original) soil moisture values or relative values, such as the percent of saturation or temporal anomalies. Over large areas, soil moisture data measured at different sites can be characterized by large differences in their minimum, mean, and maximum absolute values, even though in relative terms their temporal patterns are very similar. In these cases, the analysis considering absolute compared with percent of saturation or temporal anomaly soil moisture values can provide very different results with significant consequences for their use in hydrological applications and climate science. In this study, in situ observations from six soil moisture networks in Italy, Spain, France, Switzerland, Australia, and United States are collected and analyzed to investigate the spatial soil moisture variability over large areas (250-150,000 km2). Specifically, the statistical and temporal stability analyses of soil moisture have been carried out for absolute, temporal anomaly, and percent of saturation values (using two different formulations for temporal anomalies). The results highlight that the spatial variability of the soil moisture dynamic (i.e., temporal anomalies) is significantly lower than that of the absolute soil moisture values. The spatial variance of the time-invariant component (temporal mean of each site) is the predominant contribution to the total spatial variance of absolute soil moisture data. Moreover, half of the networks show a minimum in the spatial variability for intermediate conditions when the temporal anomalies are considered, in contrast with the widely recognized behavior of absolute soil moisture data. The analyses with percent saturation data show qualitatively similar results as those for the temporal anomalies because of the applied normalization which reduces spatial variability induced by differences in mean absolute soil moisture only. Overall, we find that the analysis of the spatial-temporal variability of absolute soil moisture does not apply to temporal anomalies or percent of saturation values.

Brocca, L.; Zucco, G.; Mittelbach, H.; Moramarco, T.; Seneviratne, S. I.

2014-07-01

455

Thermal Imaging and the Landsat Data Continuity Mission  

NASA Astrophysics Data System (ADS)

Requirements for thermal data were initially left out of Landsat Data Continuity Mission (LDCM) specifications. This omission represented a departure from data continuity. The earth observing sensors aboard Landsat 4, Landsat 5, and Landsat 7 all collected image data for a single thermal band (1040 1250 nm) with spatial resolutions of 120 m (Landsat 4 and Landsat 5) or 60 m (Landsat 7). NASA is now considering restoration of LDCM requirements for thermal data due to an increasing appreciation for the societal benefits of thermal data. In particular, the emergence of energy balance models for operational water management has raised awareness. Landsat thermal data used in conjunction with energy balance models is proving to be an efficient, cost-effective, and synoptic approach to water management in the western U.S. and world wide. Specifications for LDCM thermal images have been drafted. Two bands are specified to facilitate atmospheric correction for the retrieval of absolute surface temperature. A spatial resolution of 120 m is specified for thermal images after consideration of potential cost impacts and the maturity of thermal detector technology. Currently, NASA is considering including these thermal imaging specifications as an option in a request for proposals (RFP) for a free flying LDCM satellite. An option in the LDCM RFP offers a possibility of continuing the collection of Landsat thermal images and an option falls short of a firm requirement. The presentation will provide the status of thermal imaging requirements for the LDCM.

Irons, J. R.; Markham, B. L.

2006-12-01

456

Thermal reactor  

NASA Astrophysics Data System (ADS)

A thermal reactor apparatus and method of pyrolyticaly decomposing silane gas into liquid silicon product and hydrogen by-product gas is disclosed. The thermal reactor has a reaction chamber which is heated well above the decomposition temperature of silane. An injector probe introduces the silane gas tangentially into the reaction chamber to form a first, outer, forwardly moving vortex containing the liquid silicon product and a second, inner, rewardly moving vortex containing the by-product hydrogen gas. The liquid silicon in the first outer vortex deposits onto the interior walls of the reaction chamber to form an equilibrium skull layer which flows to the forward or bottom end of the reaction chamber where it is removed. The by-product hydrogen gas in the second inner vortex is removed from the top or rear of the reaction chamber by a vortex finder. The injector probe which introduces the silane gas into the reaction chamber is continually cooled by a cooling jacket.

Levin, H.; Ford, L. B.

1980-02-01

457

Thermal Clothing  

NASA Technical Reports Server (NTRS)

Gateway Technologies, Inc. is marketing and developing textile insulation technology originally developed by Triangle Research and Development Corporation. The enhanced thermal insulation stems from Small Business Innovation Research contracts from NASA's Johnson Space Center and the U.S. Air Force. The effectiveness of the insulation comes from the microencapsulated phase-change materials originally made to keep astronauts gloved hands warm. The applications for the product range from outer wear, housing insulation, and blankets to protective firefighting gear and scuba diving suits. Gateway has developed and begun marketing thermal regulating products under the trademark, OUTLAST. Products made from OUTLAST are already on the market, including boot and shoe liners, winter headgear, hats and caps for hunting and other outdoor sports, and a variety of men's and women's ski gloves.

1997-01-01

458

Thermal Analysis  

NASA Astrophysics Data System (ADS)

The University of Georgia used NASTRAN, a COSMIC program that predicts how a design will stand up under stress, to develop a model for monitoring the transient cooling of vegetables. The winter use of passive solar heating for poultry houses is also under investigation by the Agricultural Engineering Dept. Another study involved thermal analysis of black and green nursery containers. The use of NASTRAN has encouraged student appreciation of sophisticated computer analysis.

1986-01-01

459

Absolute photonic band gap in 2D honeycomb annular photonic crystals  

NASA Astrophysics Data System (ADS)

Using the plane wave expansion method, we investigate the effects of structural parameters on absolute photonic band gap (PBG) in two-dimensional honeycomb annular photonic crystals (PCs). The results reveal that the annular PCs possess absolute PBGs that are larger than those of the conventional air-hole PCs only when the refractive index of the material from which the PC is made is equal to 4.5 or larger. If the refractive index is smaller than 4.5, utilization of anisotropic inner rods in honeycomb annular PCs can lead to the formation of larger PBGs. The optimal structural parameters that yield the largest absolute PBGs are obtained.

Liu, Dan; Gao, Yihua; Tong, Aihong; Hu, Sen

2015-01-01

460

Absolute measurement of flats with the method of shift-rotation  

NASA Astrophysics Data System (ADS)

We present an absolute measurement of flats in a Fizeau interferometer with the method of shift-rotation, which only requires rotational measurements and shift measurement with a translation. Experiments have been carried out to verify the validity of the absolute testing method, and the results show that the reference surface deviation measured with the shift-rotation method agrees well with that of another calibration result with traditional three-flat absolute procedure; the root-mean-square (RMS) of the residual figure between them is ˜0.4 nm.

Song, Weihong; Wu, Fan; Hou, Xi; Zhao, Wenchuan; Wan, Yongjian

2013-09-01

461

On the absolute calibration of SO2 cameras  

NASA Astrophysics Data System (ADS)

Sulphur dioxide emission flux measurements are an important tool for volcanic monitoring and eruption risk assessment. The SO2 camera technique remotely measures volcanic emissions by analysing the ultraviolet absorption of SO2 in a narrow spectral window between 305 nm and 320 nm using solar radiation scattered in the atmosphere. The SO2 absorption is selectively detected by mounting band-pass interference filters in front of a two-dimensional, UV-sensitive CCD detector. While this approach is simple and delivers valuable insights into the two-dimensional SO2 distribution, absolute calibration has proven to be difficult. An accurate calibration of the SO2 camera (i.e., conversion from optical density to SO2 column density, CD) is crucial to obtain correct SO2 CDs and flux measurements that are comparable to other measurement techniques and can be used for volcanological applications. The most common approach for calibrating SO2 camera measurements is based on inserting quartz cells (cuvettes) containing known amounts of SO2 into the light path. It has been found, however, that reflections from the windows of the calibration cell can considerably affect the signal measured by the camera. Another possibility for calibration relies on performing simultaneous measurements in a small area of the camera's field-of-view (FOV) by a narrow-field-of-view Differential Optical Absorption Spectroscopy (NFOV-DOAS) system. This procedure combines the very good spatial and temporal resolution of the SO2 camera technique with the more accurate column densities obtainable from DOAS measurements. This work investigates the uncertainty of results gained through the two commonly used, but quite different calibration methods (DOAS and calibration cells). Measurements with three different instruments, an SO2 camera, a NFOV-DOAS system and an Imaging DOAS (IDOAS), are presented. We compare the calibration-cell approach with the calibration from the NFOV-DOAS system. The respective results are compared with measurements from an IDOAS to verify the calibration curve over the spatial extend of the image. Our results show that calibration cells can lead to an overestimation of the SO2 CD by up to 60% compared with CDs from the DOAS measurements. Besides these errors of calibration, radiative transfer effects (e.g. light dilution, multiple scattering) can significantly influence the results of both instrument types. These effects can lead to an even more significant overestimation or, depending on the measurement conditions, an underestimation of the true CD. Previous investigations found that possible errors can be more than an order of magnitude. However, the spectral information from the DOAS measurements allows to correct for these radiative transfer effects. The measurement presented in this work were taken at Popocatépetl, Mexico, between 1 March 2011 and 4 March 2011. Average SO2 emission rates between 4.00 kg s-1 and 14.34 kg s-1 were observed.

Lübcke, P.; Bobrowski, N.; Illing, S.; Kern, C.; Alvarez Nieves, J. M.; Vogel, L.; Zielcke, J.; Delgado Granados, H.; Platt, U.

2012-09-01

462

Thermal conductivity of subcooled liquid oxygen  

NASA Astrophysics Data System (ADS)

The thermal conductivity of liquid oxygen below 80 K and pressures up to 1 MPa has been measured using a horizontal, guarded, flat-plate calorimeter. The working equation of the calorimeter is based on the one-dimensional Fourier's law. The gap between the calorimeter plates was measured in situ from a capacitance measurement. The cooling power to the calorimeter is provided by a two-stage Gifford-McMahan cryocooler. The absolute temperatures are measured using platinum resistance thermometers. The results are compared to existing data and analytical models.

Celik, D.; Van Sciver, S. W.

2005-09-01