Science.gov

Sample records for absolute temperature means

  1. Introducing the Mean Absolute Deviation "Effect" Size

    ERIC Educational Resources Information Center

    Gorard, Stephen

    2015-01-01

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

  2. Physics of negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Abraham, Eitan; Penrose, Oliver

    2017-01-01

    Negative absolute temperatures were introduced into experimental physics by Purcell and Pound, who successfully applied this concept to nuclear spins; nevertheless, the concept has proved controversial: a recent article aroused considerable interest by its claim, based on a classical entropy formula (the "volume entropy") due to Gibbs, that negative temperatures violated basic principles of statistical thermodynamics. Here we give a thermodynamic analysis that confirms the negative-temperature interpretation of the Purcell-Pound experiments. We also examine the principal arguments that have been advanced against the negative temperature concept; we find that these arguments are not logically compelling, and moreover that the underlying "volume" entropy formula leads to predictions inconsistent with existing experimental results on nuclear spins. We conclude that, despite the counterarguments, negative absolute temperatures make good theoretical sense and did occur in the experiments designed to produce them.

  3. Cosmology with negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Vieira, J. P. P.; Byrnes, Christian T.; Lewis, Antony

    2016-08-01

    Negative absolute temperatures (NAT) are an exotic thermodynamical consequence of quantum physics which has been known since the 1950's (having been achieved in the lab on a number of occasions). Recently, the work of Braun et al. [1] has rekindled interest in negative temperatures and hinted at a possibility of using NAT systems in the lab as dark energy analogues. This paper goes one step further, looking into the cosmological consequences of the existence of a NAT component in the Universe. NAT-dominated expanding Universes experience a borderline phantom expansion (w < -1) with no Big Rip, and their contracting counterparts are forced to bounce after the energy density becomes sufficiently large. Both scenarios might be used to solve horizon and flatness problems analogously to standard inflation and bouncing cosmologies. We discuss the difficulties in obtaining and ending a NAT-dominated epoch, and possible ways of obtaining density perturbations with an acceptable spectrum.

  4. Negative absolute temperature for mobile particles

    NASA Astrophysics Data System (ADS)

    Braun, Simon; Ronzheimer, Philipp; Schreiber, Michael; Hodgman, Sean; Bloch, Immanuel; Schneider, Ulrich

    2013-05-01

    Absolute temperature is usually bound to be strictly positive. However, negative absolute temperature states, where the occupation probability of states increases with their energy, are possible in systems with an upper energy bound. So far, such states have only been demonstrated in localized spin systems with finite, discrete spectra. We realized a negative absolute temperature state for motional degrees of freedom with ultracold bosonic 39K atoms in an optical lattice, by implementing the attractive Bose-Hubbard Hamiltonian. This new state strikingly revealed itself by a quasimomentum distribution that is peaked at maximum kinetic energy. The measured kinetic energy distribution and the extracted negative temperature indicate that the ensemble is close to degeneracy, with coherence over several lattice sites. The state is as stable as a corresponding positive temperature state: The negative temperature stabilizes the system against mean-field collapse driven by negative pressure. Negative temperatures open up new parameter regimes for cold atoms, enabling fundamentally new many-body states. Additionally, they give rise to several counterintuitive effects such as heat engines with above unity efficiency.

  5. Kelvin and the absolute temperature scale

    NASA Astrophysics Data System (ADS)

    Erlichson, Herman

    2001-07-01

    This paper describes the absolute temperature scale of Kelvin (William Thomson). Kelvin found that Carnot's axiom about heat being a conserved quantity had to be abandoned. Nevertheless, he found that Carnot's fundamental work on heat engines was correct. Using the concept of a Carnot engine Kelvin found that Q1/Q2 = T1/T2. Thermometers are not used to obtain absolute temperatures since they are calculated temperatures.

  6. Consistent thermostatistics forbids negative absolute temperatures

    NASA Astrophysics Data System (ADS)

    Dunkel, Jörn; Hilbert, Stefan

    2014-01-01

    Over the past 60 years, a considerable number of theories and experiments have claimed the existence of negative absolute temperature in spin systems and ultracold quantum gases. This has led to speculation that ultracold gases may be dark-energy analogues and also suggests the feasibility of heat engines with efficiencies larger than one. Here, we prove that all previous negative temperature claims and their implications are invalid as they arise from the use of an entropy definition that is inconsistent both mathematically and thermodynamically. We show that the underlying conceptual deficiencies can be overcome if one adopts a microcanonical entropy functional originally derived by Gibbs. The resulting thermodynamic framework is self-consistent and implies that absolute temperature remains positive even for systems with a bounded spectrum. In addition, we propose a minimal quantum thermometer that can be implemented with available experimental techniques.

  7. Evaluation of the Absolute Regional Temperature Potential

    NASA Technical Reports Server (NTRS)

    Shindell, D. T.

    2012-01-01

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

  8. Absolute Temperature Monitoring Using RF Radiometry in the MRI Scanner

    PubMed Central

    El-Sharkawy, AbdEl-Monem M.; Sotiriadis, Paul P.; Bottomley, Paul A.; Atalar, Ergin

    2007-01-01

    Temperature detection using microwave radiometry has proven value for noninvasively measuring the absolute temperature of tissues inside the body. However, current clinical radiometers operate in the gigahertz range, which limits their depth of penetration. We have designed and built a noninvasive radiometer which operates at radio frequencies (64 MHz) with ∼100-kHz bandwidth, using an external RF loop coil as a thermal detector. The core of the radiometer is an accurate impedance measurement and automatic matching circuit of 0.05 Ω accuracy to compensate for any load variations. The radiometer permits temperature measurements with accuracy of ±0.1°K, over a tested physiological range of 28° C–40° C in saline phantoms whose electric properties match those of tissue. Because 1.5 T magnetic resonance imaging (MRI) scanners also operate at 64 MHz, we demonstrate the feasibility of integrating our radiometer with an MRI scanner to monitor RF power deposition and temperature dosimetry, obtaining coarse, spatially resolved, absolute thermal maps in the physiological range. We conclude that RF radiometry offers promise as a direct, noninvasive method of monitoring tissue heating during MRI studies and thereby providing an independent means of verifying patient-safe operation. Other potential applications include titration of hyper- and hypo-therapies. PMID:18026562

  9. Passive absolute age and temperature history sensor

    DOEpatents

    Robinson, Alex; Vianco, Paul T.

    2015-11-10

    A passive sensor for historic age and temperature sensing, including a first member formed of a first material, the first material being either a metal or a semiconductor material and a second member formed of a second material, the second material being either a metal or a semiconductor material. A surface of the second member is in contact with a surface of the first member such that, over time, the second material of the second member diffuses into the first material of the first member. The rate of diffusion for the second material to diffuse into the first material depends on a temperature of the passive sensor. One of the electrical conductance, the electrical capacitance, the electrical inductance, the optical transmission, the optical reflectance, or the crystalline structure of the passive sensor depends on the amount of the second material that has diffused into the first member.

  10. Nonexistence of equilibrium states at absolute negative temperatures

    NASA Astrophysics Data System (ADS)

    Romero-Rochín, Víctor

    2013-08-01

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

  11. Generalized approach for using unbiased symmetric metrics with negative values: normalized mean bias factor and normalized mean absolute error factor

    EPA Science Inventory

    Unbiased symmetric metrics provide a useful measure to quickly compare two datasets, with similar interpretations for both under and overestimations. Two examples include the normalized mean bias factor and normalized mean absolute error factor. However, the original formulations...

  12. Negative absolute temperature for motional degrees of freedom.

    PubMed

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

    2013-01-04

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

  13. Generalized approach for using unbiased symmetric metrics with negative values: normalized mean bias factor and normalized mean absolute error factor

    SciTech Connect

    Gustafson, William I.; Yu, Shaocai

    2012-10-23

    Unbiased symmetric metrics provide a useful measure to quickly compare two datasets, with similar interpretations for both under and overestimations. Two examples include the normalized mean bias factor and normalized mean absolute error factor. However, the original formulations of these metrics are only valid for datasets with positive means. This paper presents a methodology to use and interpret the metrics with datasets that have negative means. The updated formulations give identical results compared to the original formulations for the case of positive means, so researchers are encouraged to use the updated formulations going forward without introducing ambiguity.

  14. The relationship between indoor and outdoor temperature, apparent temperature, relative humidity, and absolute humidity.

    PubMed

    Nguyen, J L; Schwartz, J; Dockery, D W

    2014-02-01

    Many studies report an association between outdoor ambient weather and health. Outdoor conditions may be a poor indicator of personal exposure because people spend most of their time indoors. Few studies have examined how indoor conditions relate to outdoor ambient weather. The average indoor temperature, apparent temperature, relative humidity (RH), and absolute humidity (AH) measured in 16 homes in Greater Boston, Massachusetts, from May 2011 to April 2012 was compared to measurements taken at Boston Logan airport. The relationship between indoor and outdoor temperatures is nonlinear. At warmer outdoor temperatures, there is a strong correlation between indoor and outdoor temperature (Pearson correlation coefficient, r = 0.91, slope, β = 0.41), but at cooler temperatures, the association is weak (r = 0.40, β = 0.04). Results were similar for outdoor apparent temperature. The relationships were linear for RH and AH. The correlation for RH was modest (r = 0.55, β = 0.39). Absolute humidity exhibited the strongest indoor-to-outdoor correlation (r = 0.96, β = 0.69). Indoor and outdoor temperatures correlate well only at warmer outdoor temperatures. Outdoor RH is a poor indicator of indoor RH, while indoor AH has a strong correlation with outdoor AH year-round.

  15. Crystal face temperature determination means

    DOEpatents

    Nason, D.O.; Burger, A.

    1994-11-22

    An optically transparent furnace having a detection apparatus with a pedestal enclosed in an evacuated ampule for growing a crystal thereon is disclosed. Temperature differential is provided by a source heater, a base heater and a cold finger such that material migrates from a polycrystalline source material to grow the crystal. A quartz halogen lamp projects a collimated beam onto the crystal and a reflected beam is analyzed by a double monochromator and photomultiplier detection spectrometer and the detected peak position in the reflected energy spectrum of the reflected beam is interpreted to determine surface temperature of the crystal. 3 figs.

  16. Means of determining extrusion temperatures

    DOEpatents

    McDonald, Robert E.; Canonico, Domenic A.

    1977-01-01

    In an extrusion process comprising the steps of fabricating a metal billet, heating said billet for a predetermined time and at a selected temperature to increase its plasticity and then forcing said heated billet through a small orifice to produce a desired extruded object, the improvement comprising the steps of randomly inserting a plurality of small metallic thermal tabs at different cross sectional depths in said billet as a part of said fabricating step, and examining said extruded object at each thermal tab location for determining the crystal structure at each extruded thermal tab thus revealing the maximum temperature reached during extrusion in each respective tab location section of the extruded object, whereby the thermal profile of said extruded object during extrusion may be determined.

  17. Crystal face temperature determination means

    DOEpatents

    Nason, Donald O.; Burger, Arnold

    1994-01-01

    An optically transparent furnace (10) having a detection apparatus (29) with a pedestal (12) enclosed in an evacuated ampule (16) for growing a crystal (14) thereon. Temperature differential is provided by a source heater (20), a base heater (24) and a cold finger (26) such that material migrates from a polycrystalline source material (18) to grow the crystal (14). A quartz halogen lamp (32) projects a collimated beam (30) onto the crystal (14) and a reflected beam (34) is analyzed by a double monochromator and photomultiplier detection spectrometer (40) and the detected peak position (48) in the reflected energy spectrum (44) of the reflected beam (34) is interpreted to determine surface temperature of the crystal (14).

  18. Absolute surface profilometry of an object with large gaps by means of monochromatic laser interferometry

    NASA Astrophysics Data System (ADS)

    Liu, Zhiqiang; Uchikawa, Kiyoshi; Takeda, Mitsuo

    2011-05-01

    We propose a technique for monochromatic laser interferometry capable of absolute surface profilometry of an object with large height gaps exceeding a half wavelength. The technique does not use a broadband source, such as a low-coherence or multi-wavelength source, or a wavelength-tunable device, which causes a dispersion problem. Instead, we make use of the phase change of monochromatic light through the angular shift of illumination introduced by tilting the optical axis of the interferometer. For oblique illumination at angle θ, the phase difference between the test and reference surfaces separated by distance d is given by ΔΦ = 2kd cosθ , where k = 2π /λ is a wavenumber. In effect, the change of illumination angle θ functions as the change of wavelength λ . Therefore, while using a monochromatic laser light source, we can realize the same effect as a multi-wavelength source. From the relation between the illumination angle and the phase change, the absolute distance d between the test and reference surfaces can be determined without ambiguity of an integer multiple of a half wavelength associated with monochromatic interferometry. The large gap height can be determined also without ambiguity from the change of the absolute distance d across the boundary of the gap. Because the resolution of the absolute distance measurement by means of illumination angle change is not high enough by itself, we enhance the resolution by the following procedure. We first estimate the gap height to an integer multiple of a half wavelength by tilting the optical axis. Then the fractional portion of the phase is measured by setting the optical axis perpendicular to the test surface as in conventional interferometry. By combining the integer and the fractional portion, we can determine the absolute gap height with high accuracy and a large dynamic range exceeding a half wavelength. We present an experimental demonstration with a traditional Twyman-Green interferometer, in

  19. The relationship between indoor and outdoor temperature, apparent temperature, relative humidity, and absolute humidity

    PubMed Central

    Nguyen, Jennifer L.; Schwartz, Joel; Dockery, Douglas W.

    2013-01-01

    Introduction Many studies report an association between outdoor ambient weather and health. Outdoor conditions may be a poor indicator of personal exposure because people spend most of their time indoors. Few studies have examined how indoor conditions relate to outdoor ambient weather. Methods and Results The average indoor temperature, apparent temperature, relative humidity (RH), and absolute humidity (AH) measured in 16 homes in Greater Boston, Massachusetts, from May 2011 - April 2012 was compared to measurements taken at Boston Logan airport. The relationship between indoor and outdoor temperatures is non-linear. At warmer outdoor temperatures, there is a strong correlation between indoor and outdoor temperature (Pearson correlation coefficient, r = 0.91, slope, β = 0.41), but at cooler temperatures, the association is weak (r = 0.40, β = 0.04). Results were similar for outdoor apparent temperature. The relationships were linear for RH and AH. The correlation for RH was modest (r = 0.55, β = 0.39). AH exhibited the strongest indoor-to-outdoor correlation (r = 0.96, β = 0.69). Conclusions Indoor and outdoor temperatures correlate well only at warmer outdoor temperatures. Outdoor RH is a poor indicator of indoor RH, while indoor AH has a strong correlation with outdoor AH year-round. PMID:23710826

  20. Articulated Multimedia Physics, Lesson 14, Gases, The Gas Laws, and Absolute Temperature.

    ERIC Educational Resources Information Center

    New York Inst. of Tech., Old Westbury.

    As the fourteenth lesson of the Articulated Multimedia Physics Course, instructional materials are presented in this study guide with relation to gases, gas laws, and absolute temperature. The topics are concerned with the kinetic theory of gases, thermometric scales, Charles' law, ideal gases, Boyle's law, absolute zero, and gas pressures. The…

  1. Trends in mean and extreme temperatures over Ibadan, Southwest Nigeria

    NASA Astrophysics Data System (ADS)

    Abatan, Abayomi A.; Osayomi, Tolulope; Akande, Samuel O.; Abiodun, Babatunde J.; Gutowski, William J.

    2017-01-01

    In recent times, Ibadan has been experiencing an increase in mean temperature which appears to be linked to anthropogenic global warming. Previous studies have indicated that the warming may be accompanied by changes in extreme events. This study examined trends in mean and extreme temperatures over Ibadan during 1971-2012 at annual and seasonal scales using the high-resolution atmospheric reanalysis from European Centre for Medium-Range Weather Forecasts (ECMWF) twentieth-century dataset (ERA-20C) at 15 grid points. Magnitudes of linear trends in mean and extreme temperatures and their statistical significance were calculated using ordinary least squares and Mann-Kendall rank statistic tests. The results show that Ibadan has witnessed an increase in annual and seasonal mean minimum temperatures. The annual mean maximum temperature exhibited a non-significant decline in most parts of Ibadan. While trends in cold extremes at annual scale show warming, trends in coldest night show greater warming than in coldest day. At the seasonal scale, we found that Ibadan experienced a mix of positive and negative trends in absolute extreme temperature indices. However, cold extremes show the largest trend magnitudes, with trends in coldest night showing the greatest warming. The results compare well with those obtained from a limited number of stations. This study should inform decision-makers and urban planners about the ongoing warming in Ibadan.

  2. Fast, Computer Supported Experimental Determination of Absolute Zero Temperature at School

    ERIC Educational Resources Information Center

    Bogacz, Bogdan F.; Pedziwiatr, Antoni T.

    2014-01-01

    A simple and fast experimental method of determining absolute zero temperature is presented. Air gas thermometer coupled with pressure sensor and data acquisition system COACH is applied in a wide range of temperature. By constructing a pressure vs temperature plot for air under constant volume it is possible to obtain--by extrapolation to zero…

  3. Electrical Noise and the Measurement of Absolute Temperature, Boltzmann's Constant and Avogadro's Number.

    ERIC Educational Resources Information Center

    Ericson, T. J.

    1988-01-01

    Describes an apparatus capable of measuring absolute temperatures of a tungsten filament bulb up to normal running temperature and measuring Botzmann's constant to an accuracy of a few percent. Shows that electrical noise techniques are convenient to demonstrate how the concept of temperature is related to the micro- and macroscopic world. (CW)

  4. Meaning of temperature in different thermostatistical ensembles.

    PubMed

    Hänggi, Peter; Hilbert, Stefan; Dunkel, Jörn

    2016-03-28

    Depending on the exact experimental conditions, the thermodynamic properties of physical systems can be related to one or more thermostatistical ensembles. Here, we survey the notion of thermodynamic temperature in different statistical ensembles, focusing in particular on subtleties that arise when ensembles become non-equivalent. The 'mother' of all ensembles, the microcanonical ensemble, uses entropy and internal energy (the most fundamental, dynamically conserved quantity) to derive temperature as a secondary thermodynamic variable. Over the past century, some confusion has been caused by the fact that several competing microcanonical entropy definitions are used in the literature, most commonly the volume and surface entropies introduced by Gibbs. It can be proved, however, that only the volume entropy satisfies exactly the traditional form of the laws of thermodynamics for a broad class of physical systems, including all standard classical Hamiltonian systems, regardless of their size. This mathematically rigorous fact implies that negative 'absolute' temperatures and Carnot efficiencies more than 1 are not achievable within a standard thermodynamical framework. As an important offspring of microcanonical thermostatistics, we shall briefly consider the canonical ensemble and comment on the validity of the Boltzmann weight factor. We conclude by addressing open mathematical problems that arise for systems with discrete energy spectra.

  5. Validation of Mean Absolute Sea Level of the North Atlantic obtained from Drifter, Altimetry and Wind Data

    NASA Technical Reports Server (NTRS)

    Maximenko, Nikolai A.

    2003-01-01

    Mean absolute sea level reflects the deviation of the Ocean surface from geoid due to the ocean currents and is an important characteristic of the dynamical state of the ocean. Values of its spatial variations (order of 1 m) are generally much smaller than deviations of the geoid shape from ellipsoid (order of 100 m) that makes the derivation of the absolute mean sea level a difficult task for gravity and satellite altimetry observations. Technique used by Niiler et al. for computation of the absolute mean sea level in the Kuroshio Extension was then developed into more general method and applied by Niiler et al. (2003b) to the global Ocean. The method is based on the consideration of balance of horizontal momentum.

  6. Investigating the monthly mean stream temperature dynamics

    NASA Astrophysics Data System (ADS)

    Gallice, Aurélien; Huwald, Hendrik; Schaefli, Bettina; Rinaldo, Andrea; Lehning, Michael

    2014-05-01

    Affecting the habitat suitability of many fish species, water temperature is a hydrological factor of great concern in the actual context of climate change. Despite more than 40 years of research on this topic, the impact of landscape on the dynamics of stream temperature is still not entirely understood. In the present study, we analyzed the monthly mean stream temperature measurements collected in 26 medium-sized catchments (3-300 km2) in Switzerland. While selecting the catchments, particular attention was given to cover a large range of different geomorphological conditions, especially regarding altitude, slope and aspect. Despite these differences, it was surprisingly found that the thermal regimes of almost all the investigated streams followed a same annual trend. Only the amplitude and the minimum value of this trend were observed to differ between the individual catchments. These two factors could be successfully related to geomorphological characteristics of the catchments using multi-linear regression. The shape of the annual trend was found to vary from one year to the other. This inter-annual variability was attributed to climate, based on the significant correlation between the annual trend and air temperature. As a result of the present study, we obtained a regression model to estimate the monthly mean stream temperature in ungauged catchments based on country-wide available geomorphological variables and the average of the monthly mean air temperature over Switzerland.

  7. Modeling monthly mean air temperature for Brazil

    NASA Astrophysics Data System (ADS)

    Alvares, Clayton Alcarde; Stape, José Luiz; Sentelhas, Paulo Cesar; de Moraes Gonçalves, José Leonardo

    2013-08-01

    Air temperature is one of the main weather variables influencing agriculture around the world. Its availability, however, is a concern, mainly in Brazil where the weather stations are more concentrated on the coastal regions of the country. Therefore, the present study had as an objective to develop models for estimating monthly and annual mean air temperature for the Brazilian territory using multiple regression and geographic information system techniques. Temperature data from 2,400 stations distributed across the Brazilian territory were used, 1,800 to develop the equations and 600 for validating them, as well as their geographical coordinates and altitude as independent variables for the models. A total of 39 models were developed, relating the dependent variables maximum, mean, and minimum air temperatures (monthly and annual) to the independent variables latitude, longitude, altitude, and their combinations. All regression models were statistically significant ( α ≤ 0.01). The monthly and annual temperature models presented determination coefficients between 0.54 and 0.96. We obtained an overall spatial correlation higher than 0.9 between the models proposed and the 16 major models already published for some Brazilian regions, considering a total of 3.67 × 108 pixels evaluated. Our national temperature models are recommended to predict air temperature in all Brazilian territories.

  8. Effects of confining pressure, pore pressure and temperature on absolute permeability. SUPRI TR-27

    SciTech Connect

    Gobran, B.D.; Ramey, H.J. Jr.; Brigham, W.E.

    1981-10-01

    This study investigates absolute permeability of consolidated sandstone and unconsolidated sand cores to distilled water as a function of the confining pressure on the core, the pore pressure of the flowing fluid and the temperature of the system. Since permeability measurements are usually made in the laboratory under conditions very different from those in the reservoir, it is important to know the effect of various parameters on the measured value of permeability. All studies on the effect of confining pressure on absolute permeability have found that when the confining pressure is increased, the permeability is reduced. The studies on the effect of temperature have shown much less consistency. This work contradicts the past Stanford studies by finding no effect of temperature on the absolute permeability of unconsolidated sand or sandstones to distilled water. The probable causes of the past errors are discussed. It has been found that inaccurate measurement of temperature at ambient conditions and non-equilibrium of temperature in the core can lead to a fictitious permeability reduction with temperature increase. The results of this study on the effect of confining pressure and pore pressure support the theory that as confining pressure is increased or pore pressure decreased, the permeability is reduced. The effects of confining pressure and pore pressure changes on absolute permeability are given explicitly so that measurements made under one set of confining pressure/pore pressure conditions in the laboratory can be extrapolated to conditions more representative of the reservoir.

  9. Monitoring global monthly mean surface temperatures

    NASA Technical Reports Server (NTRS)

    Trenberth, Kevin E.; Christy, John R.; Hurrell, James W.

    1992-01-01

    The accuracy of the global surface air temperature (SST) estimates for a particular month over the past decade is assessed using all of the in situ observations available today. The sources of noise in the data, the numbers of observations, and the spatial coverage are appraised for the comparison with the climate signal, and different analyzed results are compared to determine their reproducibility. The data are further evaluated by comparing anomalies of near-global monthly mean surface temperatures with those of global satellite channel 2 microwave sounding unit temperatures for 144 months from 1979 to 1990. The results indicate that the inherent noise level in an SST observation is about 1.0 C, and this is compounded when the observation is made in regions of large temperature gradient.

  10. BOREAS AFM-06 Mean Temperature Profile Data

    NASA Technical Reports Server (NTRS)

    Wilczak, James; Hall, Forrest G. (Editor); Newcomer, Jeffrey A. (Editor); Smith, David E. (Technical Monitor)

    2000-01-01

    The Boreal Ecosystem-Atmosphere Study (BOREAS) Airborne Fluxes and Meteorology (AFM)-6 team from the National Oceanic and Atmospheric Adminsitration/Environment Technology Laboratory (NOAA/ETL) operated a 915-MHz wind/Radio Acoustic Sounding System (RASS) profiler system in the Southern Study Area (SSA) near the Old Jack Pine (OJP) tower from 21 May 1994 to 20 Sep 1994. The data set provides temperature profiles at 15 heights, containing the variables of virtual temperature, vertical velocity, the speed of sound, and w-bar. The data are stored in tabular ASCII files. The mean temperature profile data are available from the Earth Observing System Data and Information System (EOSDIS) Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC). The data files are available on a CD-ROM (see document number 20010000884).

  11. Persistency in monthly mean temperatures in Europe

    NASA Astrophysics Data System (ADS)

    Rasol, Dubravka; Ólafsson, Haraldur

    2016-04-01

    Time series from a number of weather stations in Europe have been studied in order to assess the persistency of montly mean temperatures. In most regions, the correlation between the mean temperatures of two months next to each other in time has maxima in the summer and in the winter, while there are minima in the sping and the autumn. An exception from this is in the oceanic warm climate in the southwest, where the spring minimum is missing. A plausible explanation for the positive correlation in the winter may be related to snow on the ground. The snow is associated with cold spells and increases the albedo, contributing to extension of the low temperatures. The summertime correlation may be related to the water content of the soil. A cold and rainy period results in wet soil and subsequently, relatively large part of the energy of the incoming solar radiation is consumed by evaporation, rather than sensible heating. In the spring, there is generally no snow on the ground and in the autumn, the air temperature is not as sensitive to the water content of the soil as in the summer. This may explain the low correlation in spring and autumn.

  12. Monitoring global monthly mean surface temperatures

    SciTech Connect

    Trenberth, K.E.; Hurrell, J.W. ); Christy, J.R. )

    1992-12-01

    An assessment is made of how well the monthly mean surface temperatures for the decade of the 1980s are known. The sources of noise in the data, the numbers of observations, and the spatial coverage are appraised for comparison with the climate signal, and different analyzed results are compared to see how reproducible they are. The data are further evaluated by comparing anomalies of near-global monthly mean surface temperatures with those of global satellite channel 2 microwave sounding unit (MSU) temperatures for 144 months from 1979 to 1990. Very distincitve patterns are seen in the correlation coefficients, which range from high (> 0.8) over the extratropical continents of the Northern Hemisphere, to moderate ([approximately] 0.5) over tropical and subtropical land areas, to very low over the southern oceans and tropical western Pacific. The physical difference between the two temperature measurements is one factor in these patterns. The correlation coefficient is a measure of the signal-to-noise ratio, and largest values are found where the climate signal is largest, but the spatial variation in the inherent noise in the surface observations over the oceans is the other major factor in accounting for the pattern. 42 refs., 12 figs., 4 tab.

  13. Temperature-dependent Absolute Refractive Index Measurements of Synthetic Fused Silica

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.; Frey, Bradley J.

    2006-01-01

    Using the Cryogenic, High-Accuracy Refraction Measuring System (CHARMS) at NASA's Goddard Space Flight Center, we have measured the absolute refractive index of five specimens taken from a very large boule of Corning 7980 fused silica from temperatures ranging from 30 to 310 K at wavelengths from 0.4 to 2.6 microns with an absolute uncertainty of plus or minus 1 x 10 (exp -5). Statistical variations in derived values of the thermo-optic coefficient (dn/dT) are at the plus or minus 2 x 10 (exp -8)/K level. Graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient are presented for selected wavelengths and temperatures along with estimates of uncertainty in index. Coefficients for temperature-dependent Sellmeier fits of measured refractive index are also presented to allow accurate interpolation of index to other wavelengths and temperatures. We compare our results to those from an independent investigation (which used an interferometric technique for measuring index changes as a function of temperature) whose samples were prepared from the same slugs of material from which our prisms were prepared in support of the Kepler mission. We also compare our results with sparse cryogenic index data from measurements of this material from the literature.

  14. Dynamic contribution to hemispheric mean temperature trends

    SciTech Connect

    Wallace, J.M.; Zhang, Y.; Renwick, J.A.

    1995-11-03

    On the basis of land station data from the Northern Hemisphere, it was determined that roughly half of the temporal variance of monthly mean hemispheric mean anomalies in surface air temperature during the period from 1900 through 1990 were linearly related to the amplitude of a distinctive spatial pattern in which the oceans are anomalously cold and the continents are anomalously warm poleward of 40 degrees north when the hemisphere is warm. Apart from an upward trend since 1975, to which El Nino has contributed, the amplitude time series associated with this pattern resembles seasonally dependent white noise. it is argued that the variability associated with this pattern is dynamically induced and is not necessarily an integral part of the fingerprint of global warming. 12 refs., 5 figs., 1 tab.

  15. Application of Mean of Absolute Deviation Method for the Selection of Best Nonlinear Component Based on Video Encryption

    NASA Astrophysics Data System (ADS)

    Anees, Amir; Khan, Waqar Ahmad; Gondal, Muhammad Asif; Hussain, Iqtadar

    2013-07-01

    The aim of this work is to make use of the mean of absolute deviation (MAD) method for the evaluation process of substitution boxes used in the advanced encryption standard. In this paper, we use the MAD technique to analyze some popular and prevailing substitution boxes used in encryption processes. In particular, MAD is applied to advanced encryption standard (AES), affine power affine (APA), Gray, Lui J., Residue Prime, S8 AES, SKIPJACK, and Xyi substitution boxes.

  16. Electron cyclotron emission measurements on JET: Michelson interferometer, new absolute calibration, and determination of electron temperature.

    PubMed

    Schmuck, S; Fessey, J; Gerbaud, T; Alper, B; Beurskens, M N A; de la Luna, E; Sirinelli, A; Zerbini, M

    2012-12-01

    At the fusion experiment JET, a Michelson interferometer is used to measure the spectrum of the electron cyclotron emission in the spectral range 70-500 GHz. The interferometer is absolutely calibrated using the hot/cold technique and, in consequence, the spatial profile of the plasma electron temperature is determined from the measurements. The current state of the interferometer hardware, the calibration setup, and the analysis technique for calibration and plasma operation are described. A new, full-system, absolute calibration employing continuous data acquisition has been performed recently and the calibration method and results are presented. The noise level in the measurement is very low and as a result the electron cyclotron emission spectrum and thus the spatial profile of the electron temperature are determined to within ±5% and in the most relevant region to within ±2%. The new calibration shows that the absolute response of the system has decreased by about 15% compared to that measured previously and possible reasons for this change are presented. Temperature profiles measured with the Michelson interferometer are compared with profiles measured independently using Thomson scattering diagnostics, which have also been recently refurbished and recalibrated, and agreement within experimental uncertainties is obtained.

  17. Review of deformation behavior of tungsten at temperature less than 0.2 absolute melting temperature

    NASA Technical Reports Server (NTRS)

    Stephens, J. R.

    1972-01-01

    The deformation behavior of tungsten at temperatures 0.2 T sub m is reviewed, with primary emphasis on the temperature dependence of the yield stress and the ductile-brittle transition temperature. It appears that a model based on the high Peierls stress of tungsten best accounts for the observed mechanical behavior at low temperatures. Recent research is discussed which suggests an important role of electron concentration and bonding on the mechanical behavior of tungsten. It is concluded that future research on tungsten should include studies to define more clearly the correlation between electron concentration and mechanical behavior of tungsten alloys and other transition metal alloys.

  18. Measurements of absolute absorption cross sections of ozone in the 185- to 254-nm wavelength region and the temperature dependence

    NASA Technical Reports Server (NTRS)

    Yoshino, K.; Esmond, J. R.; Freeman, D. E.; Parkinson, W. H.

    1993-01-01

    Laboratory measurements of the relative absorption cross sections of ozone at temperatures 195, 228, and 295 K have been made throughout the 185 to 254 nm wavelength region. The absolute absorption cross sections at the same temperatures have been measured at several discrete wavelengths in the 185 to 250 nm region. The absolute cross sections of ozone have been used to put the relative cross sections on a firm absolute basis throughout the 185 to 255 nm region. These recalibrated cross sections are slightly lower than those of Molina and Molina (1986), but the differences are within a few percent and would not be significant in atmospheric applications.

  19. Thermoelectric refrigerator having improved temperature stabilization means

    DOEpatents

    Falco, Charles M.

    1982-01-01

    A control system for thermoelectric refrigerators is disclosed. The thermoelectric refrigerator includes at least one thermoelectric element that undergoes a first order change at a predetermined critical temperature. The element functions as a thermoelectric refrigerator element above the critical temperature, but discontinuously ceases to function as a thermoelectric refrigerator element below the critical temperature. One example of such an arrangement includes thermoelectric refrigerator elements which are superconductors. The transition temperature of one of the superconductor elements is selected as the temperature control point of the refrigerator. When the refrigerator attempts to cool below the point, the metals become superconductors losing their ability to perform as a thermoelectric refrigerator. An extremely accurate, first-order control is realized.

  20. The impact of water temperature on the measurement of absolute dose

    NASA Astrophysics Data System (ADS)

    Islam, Naveed Mehdi

    To standardize reference dosimetry in radiation therapy, Task Group 51 (TG 51) of American Association of Physicist's in Medicine (AAPM) recommends that dose calibration measurements be made in a water tank at a depth of 10 cm and at a reference geometry. Methodologies are provided for calculating various correction factors to be applied in calculating the absolute dose. However the protocol does not specify the water temperature to be used. In practice, the temperature of water during dosimetry may vary considerably between independent sessions and different centers. In this work the effect of water temperature on absolute dosimetry has been investigated. Density of water varies with temperature, which in turn may impact the beam attenuation and scatter properties. Furthermore, due to thermal expansion or contraction air volume inside the chamber may change. All of these effects can result in a change in the measurement. Dosimetric measurements were made using a Farmer type ion chamber on a Varian Linear Accelerator for 6 MV and 23 MV photon energies for temperatures ranging from 10 to 40 °C. A thermal insulation was designed for the water tank in order to maintain relatively stable temperature over the duration of the experiment. Dose measured at higher temperatures were found to be consistently higher by a very small magnitude. Although the differences in dose were less than the uncertainty in each measurement, a linear regression of the data suggests that the trend is statistically significant with p-values of 0.002 and 0.013 for 6 and 23 MV beams respectively. For a 10 degree difference in water phantom temperatures, which is a realistic deviation across clinics, the final calculated reference dose can differ by 0.24% or more. To address this effect, first a reference temperature (e.g.22 °C) can be set as the standard; subsequently a correction factor can be implemented for deviations from this reference. Such a correction factor is expected to be of similar

  1. Is absolute noninvasive temperature measurement by the Pr[MOE-DO3A] complex feasible.

    PubMed

    Hentschel, M; Findeisen, M; Schmidt, W; Frenzel, T; Wlodarczyk, W; Wust, P; Felix, R

    2000-02-01

    Recently, the feasibility of the praseodymium complex of 10-(2-methoxyethyl)-1,4,7,10-tetraaza-cyclododecane-1,4,7-tr iacetate (Pr[MOE-DO3A]) for non-invasive temperature measurement via 1H spectroscopy has been demonstrated. Particularly the suitability of the complex for non-invasive temperature measurements including in vivo spectroscopy without spatial resolution as well as first spectroscopic imaging measurements at low temporal resolution (> or = 4 min) and high temporal resolution (breath hold, approximately 20 s) has been shown. As of today, calibration curves according to the particular experimental conditions are necessary. This work aims to clarify whether the Pr[MOE-DO3A] probe in conjunction with 1H-NMR spectroscopy allows non-invasive absolute temperature measurements with high accuracy. The measurement results from two different representative media, distilled water and human plasma, show a slight but significant dependence of the calibration curves on the surrounding medium. Calibration curves in water and plasma were derived for the temperature dependence of the chemical shift difference (F) between Pr[MOE-DO3A]'s OCH3 and water with F = -(27.53 +/- 0.04) + (0.125 +/- 0.001) x T and F = -(27.61 +/- 0.02) + (0.129 +/- 0.001) x T, respectively, with F in ppm and T in degrees C. However, the differences are minuscule even for the highest spectral resolution of 0.001 ppm/pt, so that they are indistinguishable under practical conditions. The estimated temperature errors are +/- 0.18 degrees C for water and +/- 0.14 degrees C for plasma and with that only slightly worse than the measurement accuracy of the fiber-optical temperature probe (+/- 0.1 degrees C). It can be concluded that the results obtained indicate the feasibility of the 1H spectroscopy method in conjunction with the Pr[MOE-DO3A] probe for absolute temperature measurements, with a maximum accuracy of +/- 0.2 degrees C.

  2. Absolute calibration of the OMEGA streaked optical pyrometer for temperature measurements of compressed materials

    DOE PAGES

    Gregor, M. C.; Boni, R.; Sorce, A.; ...

    2016-11-29

    Experiments in high-energy-density physics often use optical pyrometry to determine temperatures of dynamically compressed materials. In combination with simultaneous shock-velocity and optical-reflectivity measurements using velocity interferometry, these experiments provide accurate equation-of-state data at extreme pressures (P > 1 Mbar) and temperatures (T > 0.5 eV). This paper reports on the absolute calibration of the streaked optical pyrometer (SOP) at the Omega Laser Facility. The wavelength-dependent system response was determined by measuring the optical emission from a National Institute of Standards and Technology–traceable tungsten-filament lamp through various narrowband (40 nm-wide) filters. The integrated signal over the SOP’s ~250-nm operating range ismore » then related to that of a blackbody radiator using the calibrated response. We present a simple closed-form equation for the brightness temperature as a function of streak-camera signal derived from this calibration. As a result, error estimates indicate that brightness temperature can be inferred to a precision of <5%.« less

  3. Absolute calibration of the OMEGA streaked optical pyrometer for temperature measurements of compressed materials

    NASA Astrophysics Data System (ADS)

    Gregor, M. C.; Boni, R.; Sorce, A.; Kendrick, J.; McCoy, C. A.; Polsin, D. N.; Boehly, T. R.; Celliers, P. M.; Collins, G. W.; Fratanduono, D. E.; Eggert, J. H.; Millot, M.

    2016-11-01

    Experiments in high-energy-density physics often use optical pyrometry to determine temperatures of dynamically compressed materials. In combination with simultaneous shock-velocity and optical-reflectivity measurements using velocity interferometry, these experiments provide accurate equation-of-state data at extreme pressures (P > 1 Mbar) and temperatures (T > 0.5 eV). This paper reports on the absolute calibration of the streaked optical pyrometer (SOP) at the Omega Laser Facility. The wavelength-dependent system response was determined by measuring the optical emission from a National Institute of Standards and Technology-traceable tungsten-filament lamp through various narrowband (40-nm-wide) filters. The integrated signal over the SOP's ˜250-nm operating range is then related to that of a blackbody radiator using the calibrated response. We present a simple closed-form equation for the brightness temperature as a function of streak-camera signal derived from this calibration. Error estimates indicate that brightness temperature can be inferred to a precision of <5%.

  4. Absolute calibration of the OMEGA streaked optical pyrometer for temperature measurements of compressed materials

    SciTech Connect

    Gregor, M. C.; Boni, R.; Sorce, A.; Kendrick, J.; McCoy, C. A.; Polsin, D. N.; Boehly, T. R.; Celliers, P. M.; Collins, G. W.; Fratanduono, D. E.; Eggert, J. H.; Millot, M.

    2016-11-29

    Experiments in high-energy-density physics often use optical pyrometry to determine temperatures of dynamically compressed materials. In combination with simultaneous shock-velocity and optical-reflectivity measurements using velocity interferometry, these experiments provide accurate equation-of-state data at extreme pressures (P > 1 Mbar) and temperatures (T > 0.5 eV). This paper reports on the absolute calibration of the streaked optical pyrometer (SOP) at the Omega Laser Facility. The wavelength-dependent system response was determined by measuring the optical emission from a National Institute of Standards and Technology–traceable tungsten-filament lamp through various narrowband (40 nm-wide) filters. The integrated signal over the SOP’s ~250-nm operating range is then related to that of a blackbody radiator using the calibrated response. We present a simple closed-form equation for the brightness temperature as a function of streak-camera signal derived from this calibration. As a result, error estimates indicate that brightness temperature can be inferred to a precision of <5%.

  5. Calculation of the absolute thermodynamic properties of association of host-guest systems from the intermolecular potential of mean force.

    PubMed

    Ghoufi, Aziz; Malfreyt, Patrice

    2006-12-14

    The authors report calculations of the intermolecular potential of mean force (PMF) in the case of the host-guest interaction. The host-guest system is defined by a water soluble calixarene and a cation. With an organic cation such as the tetramethylammonium cation, the calixarene forms an insertion complex, whereas with the Lanthane cation, the supramolecular assembly is an outer-sphere complex. The authors apply a modified free energy perturbation method and the force constraint technique to establish the PMF profiles as a function of the separation distance between the host and guest. They use the PMF profile for the calculation of the absolute thermodynamic properties of association that they compare to the experimental values previously determined. They finish by giving some structural features of the insertion and outer-sphere complexes at the Gibbs free energy minimum.

  6. Lifespan metabolic potential of the unicellular organisms expressed by Boltzmann constant, absolute temperature and proton mass

    NASA Astrophysics Data System (ADS)

    Atanasov, Atanas Todorov

    2016-12-01

    The unicellular organisms and phages are the first appeared fundamental living organisms on the Earth. The total metabolic energy (Els, J) of these organisms can be expressed by their lifespan metabolic potential (Als, J/kg) and body mass (M, kg): Els =Als M. In this study we found a different expression - by Boltzmann's constant (k, J/K), nucleon mass (mp+, kg) of protons (and neutrons), body mass (M, kg) of organism or mass (Ms) of biomolecules (proteins, nucleotides, polysaccharides and lipids) building organism, and the absolute temperature (T, K). The found equations are: Els= (M/mp+)kT for phages and Els=(Ms/mp+)kT for the unicellular organisms. From these equations the lifespan metabolic potential can be expressed as: Als=Els/M= (k/mp+)T for phages and Als=Els/M= (k/3.3mp+)T for unicellular organisms. The temperature-normated lifespan metabolic potential (Als/T, J/K.kg) is equals to the ratio between Boltzmann's constant and nucleon mass: Als/T=k/mp+ for phages and Als/T=k/3.3mp+ for unicellular organisms. The numerical value of the k/mp+ ratio is equals to 8.254×103 J/K.kg, and the numerical value of k/3.3mp+ ratio is equal to 2.497×103 J/K.kg. These values of temperature-normated lifespan metabolic potential could be considered fundamental for the unicellular organisms.

  7. Drug Treated Schizophrenia, Schizoaffective and Bipolar Disorder Patients Evaluated by qEEG Absolute Spectral Power and Mean Frequency Analysis

    PubMed Central

    Wix-Ramos, Richard; Moreno, Xiomara; Capote, Eduardo; González, Gilbert; Uribe, Ezequiel

    2014-01-01

    Objective Research of electroencephalograph (EEG) power spectrum and mean frequency has shown inconsistent results in patients with schizophrenic, schizoaffective and bipolar disorders during medication when compared to normal subjects thus; the characterization of these parameters is an important task. Methods We applied quantitative EEG (qEEG) to investigate 38 control, 15 schizophrenic, 7 schizoaffective and 11 bipolar disorder subjects which remaine under the administration of psychotropic drugs (except control group). Absolute spectral power (ASP), mean frequency and hemispheric electrical asymmetry were measured by 19 derivation qEEG. Group mean values were compared with non parametrical Mann-Whitney test and spectral EEG maps with z-score method at p < 0.05. Results Most frequent drug treatments for schizophrenic patients were neuroleptic+antiepileptic (40% of cases) or 2 neuroleptics (33.3%). Schizoaffective patients received neuroleptic+benzodiazepine (71.4%) and for bipolar disorder patients neuroleptic+antiepileptic (81.8%). Schizophrenic (at all derivations except for Fp1, Fp2, F8 and T6) and schizoaffective (only at C3) show higher values of ASP (+57.7% and +86.1% respectively) compared to control group. ASP of bipolar disorder patients did not show differences against control group. The mean frequency was higher at Fp1 (+14.2%) and Fp2 (+17.4%) in bipolar disorder patients than control group, but no differences were found in frequencies between schizophrenic or schizoaffective patients against the control group. Majority of spectral differences were found at the left hemisphere in schizophrenic and schizoaffective but not in bipolar disorder subjects. Conclusion The present report contributes to characterize quantitatively the qEEG in drug treated schizophrenic, schizoaffective or bipolar disorder patients. PMID:24851121

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

    NASA Technical Reports Server (NTRS)

    Anderson, James E.

    1986-01-01

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

  9. Kelvin Absolute Temperature Scale Identified as Length Scale and Related to de Broglie Thermal Wavelength

    NASA Astrophysics Data System (ADS)

    Sohrab, Siavash

    Thermodynamic equilibrium between matter and radiation leads to de Broglie wavelength λdβ = h /mβvrβ and frequency νdβ = k /mβvrβ of matter waves and stochastic definitions of Planck h =hk =mk <λrk > c and Boltzmann k =kk =mk <νrk > c constants, λrkνrk = c , that respectively relate to spatial (λ) and temporal (ν) aspects of vacuum fluctuations. Photon massmk =√{ hk /c3 } , amu =√{ hkc } = 1 /No , and universal gas constant Ro =No k =√{ k / hc } result in internal Uk = Nhνrk = Nmkc2 = 3 Nmkvmpk2 = 3 NkT and potential pV = uN\\vcirc / 3 = N\\ucirc / 3 = NkT energy of photon gas in Casimir vacuum such that H = TS = 4 NkT . Therefore, Kelvin absolute thermodynamic temperature scale [degree K] is identified as length scale [meter] and related to most probable wavelength and de Broglie thermal wavelength as Tβ =λmpβ =λdβ / 3 . Parallel to Wien displacement law obtained from Planck distribution, the displacement law λwS T =c2 /√{ 3} is obtained from Maxwell -Boltzmann distribution of speed of ``photon clusters''. The propagation speeds of sound waves in ideal gas versus light waves in photon gas are described in terms of vrβ in harmony with perceptions of Huygens. Newton formula for speed of long waves in canals √{ p / ρ } is modified to √{ gh } =√{ γp / ρ } in accordance with adiabatic theory of Laplace.

  10. Teaching Absolute Value Meaningfully

    ERIC Educational Resources Information Center

    Wade, Angela

    2012-01-01

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

  11. Tools for Physiology Labs: An Inexpensive Means of Temperature Control

    PubMed Central

    Krans, Jacob L.; Hoy, Ronald R.

    2005-01-01

    We describe a simple means of modulating preparation temperature, which may be useful in undergraduate physiology laboratories. The device was developed in an effort to make teaching exercises that involve temperature modulation accessible at low cost. Although we were interested in using the device specifically with the larval fruit fly preparation, it is applicable to many preparations and temperature sensitive phenomena. Feedback driven thermoregulators offer superior precision in experiments requiring temperature control, but can be prohibitively expensive, require power supplies and circuitry, and often generate large switching transients (artifacts) during physiological recording. Moreover, many interesting exercises involving temperature control can be carried out with a slightly reduced level of temperature precision. PMID:23493108

  12. On the global mean temperature of the thermosphere

    NASA Technical Reports Server (NTRS)

    Roble, R. G.; Emergy, B. A.

    1983-01-01

    It is pointed out that the global mean temperature structure of the thermosphere above 120 km is primarily maintained by the absorption of solar extreme ultraviolet (EUV) flux at wavelengths less than 1025 A and solar ultraviolet (UV) flux. A number of previous calculations of the global mean temperature profile have determined that it is not possible to obtain agreement between the calculated global mean exospheric temperature and observed values. Since those studies, a considerable amount of new information on this problem has been obtained, including data obtained with the aid of the Atmospheric Explorer satellites. The present investigation is, therefore, concerned with a reexamination of the question whether there is enough solar UV radiation and auroral energy input to maintain the observed global mean temperature structure of the thermosphere above 120 km. It is found that for solar cycle minimum conditions there is an approximate balance between absorbed solar radiation and downward molecular thermal conduction.

  13. Evaluation of mean skin temperature formulas by infrared thermography

    NASA Astrophysics Data System (ADS)

    Choi, J. K.; Miki, K.; Sagawa, S.; Shiraki, K.

    To study the reliabiliity of formulas for calculating mean skin temperature (Tsk), values were computed by 18 different techniques and were compared with the mean of 10,841 skin temperatures measured by infrared thermography. One hundred whole-body infrared thermograms were scanned in ten resting males while changing the air temperature from 40° C to 4° C. Local, regional average and mean skin temperatures were obtained using an image processing system. The agreement frequency, defined as the percentage of the calculated Tsk values which agreed with the corresponding infrared thermographic Tsk within +/-0.2° C, ranged for with the various formulas from 7% to 80%. In many sites, the local skin temperature did not coincide with the regional average skin temperature. When the local skin temperatures which showed the highest percentage similarity to the regional average skin temperature within +/-0.4° C were applied to the formula, the agreement frequency was markedly improved for all formulas. However, the agreement frequency was not affected by changing the weighting factors from specific constants to individually measured values of regional surface area. By applying the physiologically reliable accuracy range of +/-0.2° C in the moderate and +/-0.4° C in the cool condition, agreement frequencies of at least 95% were observed in formulas involving seven or more skin temperature measurement sites, including the hand and foot. We conclude that calculation of a reliable mean skin temperature must involve more than seven skin temperature measurement sites regardless of ambient temperature. Optimal sites for skin temperature measurement are proposed for various formulas.

  14. GSOD Based Daily Global Mean Surface Temperature and Mean Sea Level Air Pressure (1982-2011)

    SciTech Connect

    Xuan Shi, Dali Wang

    2014-05-05

    This data product contains all the gridded data set at 1/4 degree resolution in ASCII format. Both mean temperature and mean sea level air pressure data are available. It also contains the GSOD data (1982-2011) from NOAA site, contains station number, location, temperature and pressures (sea level and station level). The data package also contains information related to the data processing methods

  15. Spatiotemporal trends in mean temperatures and aridity index over Rwanda

    NASA Astrophysics Data System (ADS)

    Muhire, I.; Ahmed, F.

    2016-01-01

    This study aims at quantifying the trends in mean temperatures and aridity index over Rwanda for the period of 1961-1992, based on analysis of climatic data (temperatures, precipitations, and potential evapotranspiration). The analysis of magnitude and significance of trends in temperatures and aridity index show the degree of climate change and mark the level of vulnerability to extreme events (e.g., droughts) in different areas of the country. The study reveals that mean temperatures increased in most parts of the country, with a significant increase observed in the eastern lowlands and in the southwestern parts. The highlands located in the northwest and the Congo-Nile crest showed a nonsignificant increase in mean temperatures. Aridity index increased only in March, April, October, and November, corresponding with the rainy seasons. The remaining months of the year showed a decreasing trend. At an annual resolution, the highlands and the western region showed a rise in aridity index with a decreasing pattern over the eastern lowlands and the central plateau. Generally, the highlands presented a nonsignificant increase in mean temperatures and aridity index especially during the rainy seasons. The eastern lowlands showed a significant increase in mean temperatures and decreasing trends in aridity index. Therefore, these areas are bound to experience more droughts, leading to reduced water and consequent decline in agricultural production. On the other hand, the north highlands and southwest region will continue to be more productive.

  16. THERMAL COMFORT IN RELATION TO MEAN SKIN TEMPERATURE,

    DTIC Science & Technology

    Nude men were exposed to a range of ambient temperatures and were brought to a condition of thermal comfort by adjustment of the incident radiation...was evident that mean skin temperature, per se, was not a dependable criterion of thermal comfort . (Author)

  17. Seasonal mean temperature changes control future heat waves

    NASA Astrophysics Data System (ADS)

    Argüeso, Daniel; Di Luca, Alejandro; Perkins-Kirkpatrick, Sarah E.; Evans, Jason P.

    2016-07-01

    Increased temperature will result in longer, more frequent, and more intense heat waves. Changes in temperature variability have been deemed necessary to account for future heat wave characteristics. However, this has been quantified only in Europe and North America, while the rest of the globe remains unexplored. Using late century global climate projections, we show that annual mean temperature increases is the key factor defining heat wave changes in most regions. We find that commonly studied areas are an exception rather than the standard and the mean climate change signal generally outweighs any influence from variability changes. More importantly, differences in warming across seasons are responsible for most of the heat wave changes and their consideration relegates the contribution of variability to a marginal role. This reveals that accurately capturing mean seasonal changes is crucial to estimate future heat waves and reframes our interpretation of future temperature extremes.

  18. Easy Absolute Values? Absolutely

    ERIC Educational Resources Information Center

    Taylor, Sharon E.; Mittag, Kathleen Cage

    2015-01-01

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

  19. Extreme High-Temperature Events: Changes in their probabilities with Changes in Mean Temperature.

    NASA Astrophysics Data System (ADS)

    Mearns, Linda O.; Katz, Richard W.; Schneider, Stephen H.

    1984-12-01

    Most climate impact studies rely on changes in means of meteorological variables, such as temperature, to estimate potential climate impacts, including effects on agricultural production. However, extreme meteorological events, say, a short period of abnormally high temperatures, can have a significant harmful effect on crop growth and final yield. The characteristics of daily temperature time series, specifically mean, variance and autocorrelation, are analyzed to determine possible ranges of probabilities of certain extreme temperature events [e.g., runs of consecutive daily maximum temperatures of at least 95°F (35°C)] with changes in mean temperature of the time series. The extreme temperature events considered are motivated primarily by agricultural concerns, particularly, the effects of high temperatures on corn yields in the U.S. Corn Belt. However, runs of high temperatures can also affect, for example, energy demand or morbidity and mortality of animals and humans.The relationships between changes in mean temperature and the corresponding changes in the probabilities of these extreme temperature events are quite nonlinear, with relatively small changes in mean temperature sometimes resulting in relatively large changes in event probabilities. In particular, the likelihood of occurrence of a run of five consecutive daily maximum temperatures of at least 95°F under a 3°F (1.7°C) increase in the mean (holding the variance and autocorrelation constant) is about three times greater than that under the current climate at Des Moines, Moreover, by allowing either the variance or the autocorrelation as well as the mean to change, this likelihood of a run event varies over a relatively wide range of values. These changes in the probabilities of extreme events need to be taken into consideration in order to obtain realistic estimates of the impact of climate changes such as increases in mean temperature that may arise from increases in atmospheric carbon dioxide

  20. A density-functional study of the phase diagram of cementite-type (Fe,Mn)3C at absolute zero temperature.

    PubMed

    Von Appen, Jörg; Eck, Bernhard; Dronskowski, Richard

    2010-11-15

    The phase diagram of (Fe(1-x) Mn(x))(3)C has been investigated by means of density-functional theory (DFT) calculations at absolute zero temperature. The atomic distributions of the metal atoms are not random-like as previously proposed but we find three different, ordered regions within the phase range. The key role is played by the 8d metal site which forms, as a function of the composition, differing magnetic layers, and these dominate the physical properties. We calculated the magnetic moments, the volumes, the enthalpies of mixing and formation of 13 different compositions and explain the changes of the macroscopic properties with changes in the electronic and magnetic structures by means of bonding analyses using the Crystal Orbital Hamilton Population (COHP) technique.

  1. Absolute Zero

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    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.

  2. [Interpolation of daily mean temperature by using geographically weighted regression-Kriging].

    PubMed

    Zhang, Guo-feng; Yang, Li-rong; Qu, Ming-kai; Chen, Hui-lin

    2015-05-01

    Air temperature is the input variable of numerous models in agriculture, hydrology, climate, and ecology. Currently, in study areas where the terrain is complex, methods taking into account correlation between temperature and environment variables and autocorrelation of regression residual (e.g., regression Kriging, RK) are mainly adopted to interpolate the temperature. However, such methods are based on the global ordinary least squares (OLS) regression technique, without taking into account the spatial nonstationary relationship of environment variables. Geographically weighted regression-Kriging (GWRK) is a kind of method that takes into account spatial nonstationarity relationship of environment variables and spatial autocorrelation of regression residuals of environment variables. In this study, according to the results of correlation and stepwise regression analysis, RK1 (covariates only included altitude), GWRK1 (covariates only included altitude), RK2 (covariates included latitude, altitude and closest distance to the seaside) and GWRK2 (co-variates included altitude and closest distance to the seaside) were compared to predict the spatial distribution of mean daily air temperature on Hainan Island on December 18, 2013. The prediction accuracy was assessed using the maximum positive error, maximum negative error, mean absolute error and root mean squared error based on the 80 validation sites. The results showed that GWRK1's four assessment indices were all closest to 0. The fact that RK2 and GWRK2 were worse than RK1 and GWRK1 implied that correlation among covariates reduced model performance.

  3. Extreme operative temperatures are better descriptors of the thermal environment than mean temperatures.

    PubMed

    Camacho, Agustín; Trefaut Rodrigues, Miguel; Navas, Carlos

    2015-01-01

    In ecological studies of thermal biology the thermal environment is most frequently described using the mean or other measures of central tendency in environmental temperatures. However, this procedure may hide biologically relevant thermal variation for ectotherms, potentially misleading interpretations. Extremes of operative temperatures (EOT) can help with this problem by bracketing the thermal environment of focal animals. Within this paper, we quantify how mean operative temperatures relate to the range of simultaneously available operative temperatures (a measure of error). We also show how EOT: 1) detect more thermal differences among microsites than measures of central tendency, like the mean OT, 2) allow inferring on microsite use by ectothermic animals, and 3) clarify the relationships between field operative temperatures and temperatures measured at weather stations (WS). To do that, we explored operative temperatures measured at four sites of the Brazilian Caatingas and their correspondent nearest weather stations. We found that the daily mean OT can hide temperature ranges of 41 °C simultaneously available at our study sites. In addition, EOT detected more thermal differences among microsites than central quantiles. We also show how EOT allow inferring about microsite use of ectothermic animals in a given site. Finally, the daily maximum temperature and the daily temperature range measured at WSs predicted well the minimum available field OT at localities many kilometers away. Based on our results, we recommend the use of EOT, instead of mean OT, in thermal ecology studies.

  4. Thermodynamic meaning of local temperature of nonequilibrium open quantum systems

    NASA Astrophysics Data System (ADS)

    Ye, LvZhou; Zheng, Xiao; Yan, YiJing; Di Ventra, Massimiliano

    2016-12-01

    Measuring the local temperature of nanoscale systems out of equilibrium has emerged as a new tool to study local heating effects and other local thermal properties of systems driven by external fields. Although various experimental protocols and theoretical definitions have been proposed to determine the local temperature, the thermodynamic meaning of the measured or defined quantities remains unclear. By performing analytical and numerical analysis of bias-driven quantum dot systems both in the noninteracting and strongly-correlated regimes, we elucidate the underlying physical meaning of local temperature as determined by two definitions: the zero-current condition that is widely used but not measurable and the minimal-perturbation condition that is experimentally realizable. We show that, unlike the zero-current condition, the local temperature determined by the minimal-perturbation protocol establishes a quantitative correspondence between the nonequilibrium system of interest and a reference equilibrium system, provided the probed system observable and the related electronic excitations are fully local. The quantitative correspondence thus allows the well-established thermodynamic concept to be extended to nonequilibrium situations.

  5. Radiometric absolute noise-temperature measurement system features improved accuracy and calibration ease

    NASA Technical Reports Server (NTRS)

    Brown, W.; Ewen, H.; Haroules, G.

    1970-01-01

    Radiometric receiver system, which measures noise temperatures in degrees Kelvin, does not require cryogenic noise sources for routine operation. It eliminates radiometer calibration errors associated with RF attenuation measurements. Calibrated noise source is required only for laboratory adjustment and calibration.

  6. Effects of temperature excursions on mean kinetic temperature and shelf life.

    PubMed

    Kommanaboyina, B; Rhodes, C T

    1999-12-01

    The international acceptance of the definition of controlled room temperature (CRT) has given additional impetus to the use of mean kinetic temperature (MKT) as a method of quantifying temperatures during transport and storage and consequent possible effects on drug product stability. The present paper explores some of the implications of the MKT concept and considers the effect of temperature excursions on MKT values and hence on stability of drug products.

  7. Temperature and pressure dependence of the absolute rate constant for the reactions of NH2 radicals with acetylene and ethylene

    NASA Technical Reports Server (NTRS)

    Bosco, S. R.; Nava, D. F.; Brobst, W. D.; Stief, L. J.

    1984-01-01

    The absolute rate constants for the reaction between the NH2 free radical and acetylene and ethylene is measured experimentally using a flash photolysis technique. The constant is considered to be a function of temperature and pressure. At each temperature level of the experiment, the observed pseudo-first-order rate constants were assumed to be independent of flash intensity. The results of the experiment indicate that the bimolecular rate constant for the NH2 + C2H2 reaction increases with pressure at 373 K and 459 K but not at lower temperatures. Results near the pressure limit conform to an Arrhenius expression of 1.11 (+ or -) 0.36 x 10 to the -13th over the temperature range from 241 to 459 K. For the reaction NH2 + C2H4, a smaller rate of increase in the bimolecular rate constant was observed over the temperature range 250-465 K. The implications of these results for current theoretical models of NH2 + C2H2 (or H4) reactions in the atmospheres of Jupiter and Saturn are discussed.

  8. Absolute Summ

    NASA Astrophysics Data System (ADS)

    Phillips, Alfred, Jr.

    Summ means the entirety of the multiverse. It seems clear, from the inflation theories of A. Guth and others, that the creation of many universes is plausible. We argue that Absolute cosmological ideas, not unlike those of I. Newton, may be consistent with dynamic multiverse creations. As suggested in W. Heisenberg's uncertainty principle, and with the Anthropic Principle defended by S. Hawking, et al., human consciousness, buttressed by findings of neuroscience, may have to be considered in our models. Predictability, as A. Einstein realized with Invariants and General Relativity, may be required for new ideas to be part of physics. We present here a two postulate model geared to an Absolute Summ. The seedbed of this work is part of Akhnaton's philosophy (see S. Freud, Moses and Monotheism). Most important, however, is that the structure of human consciousness, manifest in Kenya's Rift Valley 200,000 years ago as Homo sapiens, who were the culmination of the six million year co-creation process of Hominins and Nature in Africa, allows us to do the physics that we do. .

  9. Is the global mean temperature trend too low?

    NASA Astrophysics Data System (ADS)

    Venema, Victor; Lindau, Ralf

    2015-04-01

    The global mean temperature trend may be biased due to similar technological and economic developments worldwide. In this study we want to present a number of recent results that suggest that the global mean temperature trend might be steeper as generally thought. In the Global Historical Climate Network version 3 (GHCNv3) the global land surface temperature is estimated to have increased by about 0.8°C between 1880 and 2012. In the raw temperature record, the increase is 0.6°C; the 0.2°C difference is due to homogenization adjustments. Given that homogenization can only reduce biases, this 0.2°C stems from a partial correction of bias errors and it seems likely that the real non-climatic trend bias will be larger. Especially in regions with sparser networks, homogenization will not be able to improve the trend much. Thus if the trend bias in these regions is similar to the bias for more dense networks (industrialized countries), one would expect the real bias to be larger. Stations in sparse networks are representative for a larger region and are given more weight in the computation of the global mean temperature. If all stations are given equal weight, the homogenization adjustments of the GHCNv3 dataset are about 0.4°C per century. In the subdaily HadISH dataset one break with mean size 0.12°C is found every 15 years for the period 1973-2013. That would be a trend bias of 0.78°C per century on a station by station basis. Unfortunately, these estimates strongly focus on Western countries having more stations. It is known from the literature that rich countries have a (statistically insignificant) stronger trend in the global datasets. Regional datasets can be better homogenized than global ones, the main reason being that global datasets do not contain all stations known to the weather services. Furthermore, global datasets use automatic homogenization methods and have less or no metadata. Thus while regional data can be biased themselves, comparing them

  10. The Stumbling Block of the Gibbs Entropy: the Reality of the Negative Absolute Temperatures

    NASA Astrophysics Data System (ADS)

    Anghel, Dragoş-Victor

    2016-02-01

    The second Tisza-Callen postulate of equilibrium thermodynamics states that for any system there exists a function of the system extensive parameters, called entropy, defined for all equilibrium states and having the property that the values assumed by the extensive parameters in the absence of a constraint are those that maximize the entropy over the manifold of constrained equilibrium states. Based on the thermodynamic evolution of systems which (in the Boltzmann description) have positive and negative temperatures, we show that this postulate is satisfied by the Boltzmann formula for the entropy and may be violated by the Gibbs formula, therefore invalidating the later. Vice versa, if we assume, by reductio ad absurdum, that for some thermodynamic systems the equilibrium state is determined by the Gibbs' prescription and not by Boltzmann's, this implies that such systems have macroscopic fluctuations and therefore do not reach the thermodynamic equilibrium.

  11. The brightness temperature of Venus and the absolute flux-density scale at 608 MHz.

    NASA Technical Reports Server (NTRS)

    Muhleman, D. O.; Berge, G. L.; Orton, G. S.

    1973-01-01

    The disk temperature of Venus was measured at 608 MHz near the inferior conjunction of 1972, and a value of 498 plus or minus 33 K was obtained using a nominal CKL flux-density scale. The result is consistent with earlier measurements, but has a much smaller uncertainty. Our theoretical model prediction is larger by a factor of 1.21 plus or minus 0.09. This discrepancy has been noticed previously for frequencies below 1400 MHz, but was generally disregarded because of the large observational uncertainties. No way could be found to change the model to produce agreement without causing a conflict with well-established properties of Venus. Thus it is suggested that the flux-density scale may require an upward revision, at least near this frequency, in excess of what has previously been considered likely.

  12. Differences between true mean temperatures and means calculated with four different approaches: a case study from three Croatian stations

    NASA Astrophysics Data System (ADS)

    Bonacci, Ognjen; Željković, Ivana

    2016-12-01

    Different countries use varied methods for daily mean temperature calculation. None of them assesses precisely the true daily mean temperature, which is defined as the integral of continuous temperature measurements in a day. Of special scientific as well as practical importance is to find out how temperatures calculated by different methods and approaches deviate from the true daily mean temperature. Five mean daily temperatures were calculated (T0, T1, T2, T3, T4) using five different equations. The mean of 24-h temperature observations during the calendar day is accepted to represent the true, daily mean T0. The differences Δi between T0 and four other mean daily temperatures T1, T2, T3, and T4 were calculated and analysed. In the paper, analyses were done with hourly data measured in a period from 1 January 1999 to 31 December 2014 (149,016 h, 192 months and 16 years) at three Croatian meteorological stations. The stations are situated in distinct climatological areas: Zagreb Grič in a mild climate, Zavižan in the cold mountain region and Dubrovnik in the hot Mediterranean. Influence of fog on the temperature is analysed. Special attention is given to analyses of extreme (maximum and minimum) daily differences occurred at three analysed stations. Selection of the fixed local hours, which is in use for calculation of mean daily temperature, plays a crucial role in diminishing of bias from the true daily temperature.

  13. Effects of Temperature, Relative Humidity, Absolute Humidity, and Evaporation Potential on Survival of Airborne Gumboro Vaccine Virus

    PubMed Central

    Zhao, Yang; Dijkman, Remco; Fabri, Teun; de Jong, Mart C. M.; Groot Koerkamp, Peter W. G.

    2012-01-01

    Survival of airborne virus influences the extent of disease transmission via air. How environmental factors affect viral survival is not fully understood. We investigated the survival of a vaccine strain of Gumboro virus which was aerosolized at three temperatures (10°C, 20°C, and 30°C) and two relative humidities (RHs) (40% and 70%). The response of viral survival to four metrics (temperature, RH, absolute humidity [AH], and evaporation potential [EP]) was examined. The results show a biphasic viral survival at 10°C and 20°C, i.e., a rapid initial inactivation in a short period (2.3 min) during and after aerosolization, followed by a slow secondary inactivation during a 20-min period after aerosolization. The initial decays of aerosolized virus at 10°C (1.68 to 3.03 ln % min−1) and 20°C (3.05 to 3.62 ln % min−1) were significantly lower than those at 30°C (5.67 to 5.96 ln % min−1). The secondary decays at 10°C (0.03 to 0.09 ln % min−1) tended to be higher than those at 20°C (−0.01 to 0.01 ln % min−1). The initial viral survival responded to temperature and RH and potentially to EP; the secondary viral survival responded to temperature and potentially to RH. In both phases, survival of the virus was not significantly affected by AH. These findings suggest that long-distance transmission of airborne virus is more likely to occur at 20°C than at 10°C or 30°C and that current Gumboro vaccination by wet aerosolization in poultry industry is not very effective due to the fast initial decay. PMID:22156417

  14. CMOS temperature sensor using a resistively degenerated common-source amplifier biased by an adjustable proportional-to-absolute-temperature voltage

    NASA Astrophysics Data System (ADS)

    Wang, Ruey-Lue; Fu, Chien-Cheng; Yu, Chi; Hao, Yi-Fan; Shi, Jian-Liang; Lin, Chen-Fu; Liao, Hsin-Hao; Tsai, Hann-Huei; Juang, Ying-Zong

    2014-01-01

    A high-linearity CMOS temperature sensor with pulse output is presented. The temperature core is a resistively degenerated common-source amplifier which gate is biased by a proportional-to-absolute-temperature (PTAT) voltage generator. The source resistor is made of polysilicon which resistance has a PTAT characteristic. The current flowing through the resistor exhibits a PTAT characteristic with high linearity of 99.99% at least for a temperature range from 0 to 125 °C. The PTAT voltage generator can be adjusted by a bias voltage Vb and hence the PTAT current can also be adjusted by the Vb. The PTAT current is mirrored to an added current controlled oscillator which output pulse frequencies also exhibit a PTAT characteristic. For the chip using the 0.35 µm process, the plots of measured pulse frequencies against temperature exhibit the sensitivity of 2.30 to 2.24 kHz/°C with linearity of more than 99.99% at the Vb of 1 to 1.2 V.

  15. What does global mean temperature tell us about local climate?

    PubMed

    Sutton, Rowan; Suckling, Emma; Hawkins, Ed

    2015-11-13

    The subject of climate feedbacks focuses attention on global mean surface air temperature (GMST) as the key metric of climate change. But what does knowledge of past and future GMST tell us about the climate of specific regions? In the context of the ongoing UNFCCC process, this is an important question for policy-makers as well as for scientists. The answer depends on many factors, including the mechanisms causing changes, the timescale of the changes, and the variables and regions of interest. This paper provides a review and analysis of the relationship between changes in GMST and changes in local climate, first in observational records and then in a range of climate model simulations, which are used to interpret the observations. The focus is on decadal timescales, which are of particular interest in relation to recent and near-future anthropogenic climate change. It is shown that GMST primarily provides information about forced responses, but that understanding and quantifying internal variability is essential to projecting climate and climate impacts on regional-to-local scales. The relationship between local forced responses and GMST is often linear but may be nonlinear, and can be greatly complicated by competition between different forcing factors. Climate projections are limited not only by uncertainties in the signal of climate change but also by uncertainties in the characteristics of real-world internal variability. Finally, it is shown that the relationship between GMST and local climate provides a simple approach to climate change detection, and a useful guide to attribution studies.

  16. Thermometry, calorimetry, and mean body temperature during heat stress.

    PubMed

    Kenny, Glen P; Jay, Ollie

    2013-10-01

    Heat balance in humans is maintained at near constant levels through the adjustment of physiological mechanisms that attain a balance between the heat produced within the body and the heat lost to the environment. Heat balance is easily disturbed during changes in metabolic heat production due to physical activity and/or exposure to a warmer environment. Under such conditions, elevations of skin blood flow and sweating occur via a hypothalamic negative feedback loop to maintain an enhanced rate of dry and evaporative heat loss. Body heat storage and changes in core temperature are a direct result of a thermal imbalance between the rate of heat production and the rate of total heat dissipation to the surrounding environment. The derivation of the change in body heat content is of fundamental importance to the physiologist assessing the exposure of the human body to environmental conditions that result in thermal imbalance. It is generally accepted that the concurrent measurement of the total heat generated by the body and the total heat dissipated to the ambient environment is the most accurate means whereby the change in body heat content can be attained. However, in the absence of calorimetric methods, thermometry is often used to estimate the change in body heat content. This review examines heat exchange during challenges to heat balance associated with progressive elevations in environmental heat load and metabolic rate during exercise. Further, we evaluate the physiological responses associated with heat stress and discuss the thermal and nonthermal influences on the body's ability to dissipate heat from a heat balance perspective.

  17. What does global mean temperature tell us about local climate?

    PubMed Central

    Sutton, Rowan; Suckling, Emma; Hawkins, Ed

    2015-01-01

    The subject of climate feedbacks focuses attention on global mean surface air temperature (GMST) as the key metric of climate change. But what does knowledge of past and future GMST tell us about the climate of specific regions? In the context of the ongoing UNFCCC process, this is an important question for policy-makers as well as for scientists. The answer depends on many factors, including the mechanisms causing changes, the timescale of the changes, and the variables and regions of interest. This paper provides a review and analysis of the relationship between changes in GMST and changes in local climate, first in observational records and then in a range of climate model simulations, which are used to interpret the observations. The focus is on decadal timescales, which are of particular interest in relation to recent and near-future anthropogenic climate change. It is shown that GMST primarily provides information about forced responses, but that understanding and quantifying internal variability is essential to projecting climate and climate impacts on regional-to-local scales. The relationship between local forced responses and GMST is often linear but may be nonlinear, and can be greatly complicated by competition between different forcing factors. Climate projections are limited not only by uncertainties in the signal of climate change but also by uncertainties in the characteristics of real-world internal variability. Finally, it is shown that the relationship between GMST and local climate provides a simple approach to climate change detection, and a useful guide to attribution studies. PMID:26438282

  18. Use of the portable infrared thermometer as a means of measuring limb surface temperature in the horse

    SciTech Connect

    Palmer, S.E.

    1981-01-01

    Evaluation was made of the portable infrared thermometer to measure limb surface temperature in 3 horses--first standing in a stall and then placed in lateral recumbency under general anesthesia. To determine the effect of pigment, black and white targets were examined with the instrument under various clinical conditions. In each horse, thermal gradient measurements were consistent along the extremities. Mean limb surface temperatures were less than rectal temperature and greater than ambient temperature. Limb surface temperatures measured in lateral recumbency under general anesthesia were uniformly higher than those obtained in the standing position in the stall. The average SD of absolute temperature measurements made under general anesthesia was +/- 0.1 C, whereas the average SD of those made in standing horses was +/- 0.2 C. For practical use, the latter deviation of +/- 0.2 C was considered more appropriate as the limit of significance for clinical measurements made with the instrument. When used indoors in the absence of direct sunlight, the influence of pigment on measurements made with the instrument was not significant. Optimal conditions for the clinical use of the portable infrared thermometer are defined and factors which affect limb surface temperature are discussed.

  19. Relationship between global mean sea-level and global mean temperature in a climate simulation of the past millennium

    NASA Astrophysics Data System (ADS)

    Storch, Hans Von; Zorita, Eduardo; González-Rouco, Jesús F.

    2008-11-01

    The possibility of using global mean near-surface temperature, its rate of change or the global mean ocean heat-flux as predictors to statistically estimate the change of global mean sea-level is explored in the context of a long climate simulation of the past millennium with the climate model ECHO-G. Such relationships have recently been proposed to by-pass the difficulty of estimating future sea-level changes based on simulations with coarse-resolution climate models. It is found that, in this simulation, a simple linear relationship between mean temperature and the rate of change of sea level does not exist. A regression parameter linking both variables, and estimated in sliding 120-year windows, varies widely along the simulation and, in some periods, even attains negative values. The ocean heat-flux and the rate-of-change of mean temperature seem to better capture the rate-of-change of sea level due to thermal expansion.

  20. A Climatology of Monthly Mean Sea Surface Temperatures for the Gulf of Mexico,

    DTIC Science & Technology

    1978-01-01

    This report presents monthly mean sea surface temperatures for the Gulf of Mexico in one degree quadrangles. It also includes a short discussion of the temperature data and the ocean currents in the Gulf of Mexico .

  1. Absolute Photometry

    NASA Astrophysics Data System (ADS)

    Hartig, George

    1990-12-01

    The absolute sensitivity of the FOS will be determined in SV by observing 2 stars at 3 epochs, first in 3 apertures (1.0", 0.5", and 0.3" circular) and then in 1 aperture (1.0" circular). In cycle 1, one star, BD+28D4211 will be observed in the 1.0" aperture to establish the stability of the sensitivity and flat field characteristics and improve the accuracy obtained in SV. This star will also be observed through the paired apertures since these are not calibrated in SV. The stars will be observed in most detector/grating combinations. The data will be averaged to form the inverse sensitivity functions required by RSDP.

  2. Absolute and relative blindsight.

    PubMed

    Balsdon, Tarryn; Azzopardi, Paul

    2015-03-01

    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.

  3. Interaction of Mean Temperature and Daily Fluctuation Influences Dengue Incidence in Dhaka, Bangladesh.

    PubMed

    Sharmin, Sifat; Glass, Kathryn; Viennet, Elvina; Harley, David

    2015-01-01

    Local weather influences the transmission of the dengue virus. Most studies analyzing the relationship between dengue and climate are based on relatively coarse aggregate measures such as mean temperature. Here, we include both mean temperature and daily fluctuations in temperature in modelling dengue transmission in Dhaka, the capital of Bangladesh. We used a negative binomial generalized linear model, adjusted for rainfall, anomalies in sea surface temperature (an index for El Niño-Southern Oscillation), population density, the number of dengue cases in the previous month, and the long term temporal trend in dengue incidence. In addition to the significant associations of mean temperature and temperature fluctuation with dengue incidence, we found interaction of mean and temperature fluctuation significantly influences disease transmission at a lag of one month. High mean temperature with low fluctuation increases dengue incidence one month later. Besides temperature, dengue incidence was also influenced by sea surface temperature anomalies in the current and previous month, presumably as a consequence of concomitant anomalies in the annual rainfall cycle. Population density exerted a significant positive influence on dengue incidence indicating increasing risk of dengue in over-populated Dhaka. Understanding these complex relationships between climate, population, and dengue incidence will help inform outbreak prediction and control.

  4. Absolute dose measurements by means of a small cylindrical ionization chamber for very high dose per pulse high energy electron beams

    SciTech Connect

    Karaj, E.; Righi, S.; Di Martino, F.

    2007-03-15

    Very high dose per pulse (3-13 cGy/pulse) high energy electron beams are currently produced by special linear accelerators (linac) dedicated to Intra Operative Radiation Therapy (IORT). The electron beams produced by such linacs are collimated by special Perspex applicators of various size and cylindrically shaped. The biggest problems from the dosimetric point of view are caused by the high dose-per-pulse values and the use of inclined applicators. In this work measurements of absolute dose for the inclined applicators were done by using a small cylindrical ionization chamber, type CC01 (Wellhofer), a parallel plane ionization chamber type Markus (PTW 23343) and radiochromic films type EBT. We show a method which allows calculating the quality correction factors for CC01 chamber with an uncertainty of 1% and the absolute dose value for the inclined applicators using CC01 with an uncertainty of 3.1% for electron beams of energy of 6 and 7 MeV produced by the linac dedicated to IORT Novac7.

  5. Measurement of absolute transition frequencies of {sup 87}Rb to nS and nD Rydberg states by means of electromagnetically induced transparency

    SciTech Connect

    Mack, Markus; Karlewski, Florian; Hattermann, Helge; Hoeckh, Simone; Jessen, Florian; Cano, Daniel; Fortagh, Jozsef

    2011-05-15

    We report the measurement of absolute excitation frequencies of {sup 87}Rb to nS and nD Rydberg states. The Rydberg transition frequencies are obtained by observing electromagnetically induced transparency on a rubidium vapor cell. The accuracy of the measurement of each state is < or approx. 1 MHz, which is achieved by frequency stabilizing the two diode lasers employed for the spectroscopy to a frequency comb and a frequency comb calibrated wavelength meter, respectively. Based on the spectroscopic data we determine the quantum defects of {sup 87}Rb, and compare it with previous measurements on {sup 85}Rb. We determine the ionization frequency from the 5S{sub 1/2}(F=1) ground state of {sup 87}Rb to 1010.029 164 6(3)THz, providing the binding energy of the ground state with an accuracy improved by two orders of magnitude.

  6. An evaluation of monthly mean MSU and ECMWF global atmospheric temperatures for monitoring climate

    NASA Technical Reports Server (NTRS)

    Hurrell, James W.; Trenberth, Kevin E.

    1992-01-01

    The usefulness of global satellite sounding data for monitoring climate was assessed by comparing monthly mean brightness temperature anomalies derived from channel 2 of the microwave sounding units (MSUs) on board NOAA satellites over the past decade with both weighted and pressure-level ECMWF monthly mean temperatures for 96 months from 1982 to 1989. Results show that very good agreement exists between the MSU and the weighted ECMWF temperatures over the period considered, with grid-point correlations exceeding 0.85. Comparisons with individual pressure-level temperatures from ECMWF showed high correlations at 300 mb over most of the globe.

  7. Hot of Not: Physiological versus Meteorological Heatwaves-Support for a Mean Temperature Threshold.

    PubMed

    Luther, Matt; Gardiner, Fergus W; Hansen, Claire; Caldicott, David

    2016-07-26

    The aim of this study was to determine whether a revised heat warning threshold provides an enhanced predictive tool for increases in Emergency Department heat-related presentations in Canberra, Australia. All Emergency Department triage records containing the word "heat", as well as those diagnosing a heat related illness for the summer periods 2013/2014, 2014/2015, and 2015/2016 were searched. Then a medical record review was conducted to confirm that the patient's presentation was related to environmental heat, which was defined by the final clinical diagnosis, presentation complaint and details of the patient's treatment. Researchers then compared this presentation data, to a mean threshold formula. The mean threshold formula included the past three consecutive daily mean temperatures and the last measured temperature upon presentation. This formula was designed to take into account the variance of night-time lows, with concurrent daily ambient temperatures, and was used to determine whether there was a correlation between heat-related presentations and increasing mean temperatures. Heat-related presentations appeared to occur when the mean threshold temperature reached 25 °C (77 °F), with significant increases when the mean threshold reached 30 °C (86 °F). These results confirm that a mean temperature of 30 °C corresponds to a relevant local public health heat-related threat.

  8. Hot of Not: Physiological versus Meteorological Heatwaves—Support for a Mean Temperature Threshold

    PubMed Central

    Luther, Matt; Gardiner, Fergus W.; Hansen, Claire; Caldicott, David

    2016-01-01

    The aim of this study was to determine whether a revised heat warning threshold provides an enhanced predictive tool for increases in Emergency Department heat-related presentations in Canberra, Australia. All Emergency Department triage records containing the word “heat”, as well as those diagnosing a heat related illness for the summer periods 2013/2014, 2014/2015, and 2015/2016 were searched. Then a medical record review was conducted to confirm that the patient’s presentation was related to environmental heat, which was defined by the final clinical diagnosis, presentation complaint and details of the patient’s treatment. Researchers then compared this presentation data, to a mean threshold formula. The mean threshold formula included the past three consecutive daily mean temperatures and the last measured temperature upon presentation. This formula was designed to take into account the variance of night-time lows, with concurrent daily ambient temperatures, and was used to determine whether there was a correlation between heat-related presentations and increasing mean temperatures. Heat-related presentations appeared to occur when the mean threshold temperature reached 25 °C (77 °F), with significant increases when the mean threshold reached 30 °C (86 °F). These results confirm that a mean temperature of 30 °C corresponds to a relevant local public health heat-related threat. PMID:27472348

  9. Absolute absorption coefficient of C6H2 in the mid-UV range at low temperature; implications for the interpretation of Titan atmospheric spectra.

    PubMed

    Bénilan, Y; Bruston, P; Raulin, F; Courtin, R; Guillemin, J C

    1995-01-01

    The interpretation of mid-UV albedo spectra of planetary atmospheres, especially that of Titan, is the main goal of the SIPAT (Spectroscopie uv d'Interet Prebiologique dans l'Atmosphere de Titan) research program. This laboratory experiment has been developed in order to systematically determine the absorption coefficients of molecular compounds which are potential absorbers of scattered sunlight in planetary atmospheres, with high spectral resolution, and at various temperatures below room temperature. From photochemical modelling and experimental simulations, we may expect triacetylene (C6H2) to be present in the atmosphere of Titan, even though it has not yet been detected. We present here the first determination of the absolute absorption coefficient of that compound in the 200-300 nm range and at two temperatures (296 K and 233 K). The temperature dependence of the C6H2 absorption coefficient in that wavelength range is compared to that previously observed in the case of cyanoacetylene (HC3N). We then discuss the implications of the present results for the interpretation of Titan UV spectra, where it appears that large uncertainities can be introduced either by the presence of trace impurities in laboratory samples or by the variations of absorption coefficients with temperature.

  10. Meaning

    NASA Astrophysics Data System (ADS)

    Harteveld, Casper

    The second world to be considered concerns Meaning. In contrast to Reality and Play, this world relates to the people, disciplines, and domains that are focused on creating a certain value. For example, if this value is about providing students knowledge about physics, it involves teachers, the learning sciences, and the domains education and physics. This level goes into the aspects and criteria that designers need to take into account from this perspective. The first aspect seems obvious when we talk of “games with a serious purpose.” They have a purpose and this needs to be elaborated on, for example in terms of what “learning objectives” it attempts to achieve. The subsequent aspect is not about what is being pursued but how. To attain a value, designers have to think about a strategy that they employ. In my case this concerned looking at the learning paradigms that have come into existence in the past century and see what they have to tell us about learning. This way, their principles can be translated into a game environment. This translation involves making the strategy concrete. Or, in other words, operationalizing the plan. This is the third aspect. In this level, I will further specifically explain how I derived requirements from each of the learning paradigms, like reflection and exploration, and how they can possibly be related to games. The fourth and final aspect is the context in which the game is going to be used. It matters who uses the game and when, where, and how the game is going to be used. When designers have looked at these aspects, they have developed a “value proposal” and the worth of it may be judged by criteria, like motivation, relevance, and transfer. But before I get to this, I first go into how we human beings are meaning creators and what role assumptions, knowledge, and ambiguity have in this. I will illustrate this with some silly jokes about doctors and Mickey Mouse, and with an illusion.

  11. Estimation of daily mean air temperature from satellite derived radiometric data

    NASA Technical Reports Server (NTRS)

    Phinney, D.

    1976-01-01

    The Screwworm Eradication Data System (SEDS) at JSC utilizes satellite derived estimates of daily mean air temperature (DMAT) to monitor the effect of temperature on screwworm populations. The performance of the SEDS screwworm growth potential predictions depends in large part upon the accuracy of the DMAT estimates.

  12. Zero-Temperature, Mean-Field Theory of Atomic Bose-Einstein Condensates

    PubMed Central

    Edwards, Mark; Dodd, R. J.; Clark, Charles W.; Burnett, K.

    1996-01-01

    We review the application of zero-temperature, mean-field theory to current experimental atomic Bose-Einstein condensates. We assess the validity of the approximations made by comparing the mean-field results with a variety of experimental data. PMID:27805108

  13. Analysis of weighted mean temperature of Algeria for GNSS water vapor sounding

    NASA Astrophysics Data System (ADS)

    Song, DongSeob; Boutiouta, Seddik

    2014-05-01

    Atmospheric water vapour is important for the climate system and a key to understand the hydrological cycle. The hydrological cycle describes the transfer of water in solid, liquid and gaseous form through these phases as well as the physical movement of water within the ecosystem of the earth and between its atmospheres; oceans and continents. Nowadays the accuracy of water vapour estimates based on GNSS observations is comparable to radiosonde and radiometer data. On the other hand, the solution of GNSS precipitable water vapour can be quantified the radiosonde humidity errors and biases with the role of radiosonde observations in the climate studies. The weighted mean temperature in troposphere is a critical parameter in the conversion of wet zenith delay to perceptible water vapour in GNSS Meteorology. In the retrieval of integrated water vapour from GNSS zenith wet delay, effect of temperature is to be taken into account. However, effect of temperature and water vapour partial pressure are interrelated. Therefore, the vertical profiles of temperature are taken into account through a term called weighted mean temperature. In this study, we processed the radiosonde data which are provided by World Meteorological Observation network and surface temperature data at 5 stations in Algeria from 2006 to 2007 to determine weighted mean temperature equation. The coefficients a and b are of weighted mean temperature linear equation were determined by a least square regression method of the 4,944 data pairs after outlier data, which are over 3σ of differences between mean temperature in troposphere and surface temperature, were eliminated. Finally, we determined the Algerian weighted mean temperature model (AWMTM) that the relationship between mean temperature as function of surface temperature for the entire Algerian area, with the RMSE and the correlation coefficient of AWMTM are represented about 6.80 K and 0.75, respectively. The stations which are located in desert

  14. Absolute rate determinations and temperature dependences of the gas-phase reactions of O( 3P) with halogenated propenes

    NASA Astrophysics Data System (ADS)

    Cometto, Pablo M.; Teruel, Mariano A.; Taccone, Raúl A.; Lane, Silvia I.

    2006-01-01

    The rate constants for the gas-phase reactions of ground state oxygen atoms with CF 3CH dbnd CH 2 (1), CF 3CF dbnd CF 2 (2) and CF 3CCl dbnd CCl 2 (3) have been measured directly using a discharge flow tube employing the O( 3P) chemiluminescence titration method. The experiments were carried out under pseudo-first-order conditions with [O( 3P)] 0 ≪ [propene] 0. The temperature dependences of the reactions were studied for the first time in the range 298-363 K. The Arrhenius expressions obtained (in units of cm 3 molecule -1 s -1) were: k1 = (0.28 ± 0.09) × 10 -11 exp[-(10.4 ± 0.9) × 10 3/ RT], k2 = (1.57 ± 0.72) × 10 -11 exp[-(15.6 ± 1.3) × 10 3/ RT], k3 = (2.23 ± 1.27) × 10 -11 exp[-(16.0 ± 1.6) × 10 3/ RT]. All the rate coefficients display a positive temperature dependence which points to the importance of the irreversibility of the addition mechanism for these reactions. Halogen substitution in the alkenes is discussed in terms of reactivity with O( 3P) and its relation with the ionization potential.

  15. Absolute rate of the reaction of O/3-P/ with hydrogen sulfide over the temperature range 263 to 495 K

    NASA Technical Reports Server (NTRS)

    Whytock, D. A.; Timmons, R. B.; Lee, J. H.; Michael, J. V.; Payne, W. A.; Stief, L. J.

    1976-01-01

    The technique of flash photolysis coupled with time resolved detection of O via resonance fluorescence has been used to obtain rate constants for the reaction of O(3-P) with H2S at temperatures from 263 to 495 K and at pressures in the range 10-400 torr. Under conditions where secondary reactions are avoided, the measured rate constants for the primary step obey the Arrhenius equation k = (7.24 plus or minus 1.07) x 10 to the -12th exp(-3300 plus or minus 100/1.987 T) cu cm/molecules/s. Experiments with D2S show that the reaction exhibits a primary isotope effect, in support of a hydrogen abstraction mechanism.

  16. Sampling biases in datasets of historical mean air temperature over land.

    PubMed

    Wang, Kaicun

    2014-04-10

    Global mean surface air temperature (Ta) has been reported to have risen by 0.74°C over the last 100 years. However, the definition of mean Ta is still a subject of debate. The most defensible definition might be the integral of the continuous temperature measurements over a day (Td0). However, for technological and historical reasons, mean Ta over land have been taken to be the average of the daily maximum and minimum temperature measurements (Td1). All existing principal global temperature analyses over land rely heavily on Td1. Here, I make a first quantitative assessment of the bias in the use of Td1 to estimate trends of mean Ta using hourly Ta observations at 5600 globally distributed weather stations from the 1970s to 2013. I find that the use of Td1 has a negligible impact on the global mean warming rate. However, the trend of Td1 has a substantial bias at regional and local scales, with a root mean square error of over 25% at 5° × 5° grids. Therefore, caution should be taken when using mean Ta datasets based on Td1 to examine high resolution details of warming trends.

  17. Sampling Biases in Datasets of Historical Mean Air Temperature over Land

    NASA Astrophysics Data System (ADS)

    Wang, Kaicun

    2014-04-01

    Global mean surface air temperature (Ta) has been reported to have risen by 0.74°C over the last 100 years. However, the definition of mean Ta is still a subject of debate. The most defensible definition might be the integral of the continuous temperature measurements over a day (Td0). However, for technological and historical reasons, mean Ta over land have been taken to be the average of the daily maximum and minimum temperature measurements (Td1). All existing principal global temperature analyses over land rely heavily on Td1. Here, I make a first quantitative assessment of the bias in the use of Td1 to estimate trends of mean Ta using hourly Ta observations at 5600 globally distributed weather stations from the 1970s to 2013. I find that the use of Td1 has a negligible impact on the global mean warming rate. However, the trend of Td1 has a substantial bias at regional and local scales, with a root mean square error of over 25% at 5° × 5° grids. Therefore, caution should be taken when using mean Ta datasets based on Td1 to examine high resolution details of warming trends.

  18. A review of progress towards understanding the transient global mean surface temperature response to radiative perturbation

    NASA Astrophysics Data System (ADS)

    Yoshimori, Masakazu; Watanabe, Masahiro; Shiogama, Hideo; Oka, Akira; Abe-Ouchi, Ayako; Ohgaito, Rumi; Kamae, Youichi

    2016-12-01

    The correct understanding of the transient response to external radiative perturbation is important for the interpretation of observed climate change, the prediction of near-future climate change, and committed warming under climate stabilization scenarios, as well as the estimation of equilibrium climate sensitivity based on observation data. It has been known for some time that the radiative damping rate per unit of global mean surface temperature increase varies with time, and this inconstancy affects the transient response. Knowledge of the equilibrium response alone is insufficient, but understanding the transient response of the global mean surface temperature has made rapid progress. The recent progress accompanies the relatively new concept of the efficacies of ocean heat uptake and forcing. The ocean heat uptake efficacy associates the temperature response induced by ocean heat uptake with equilibrium temperature response, and the efficacy of forcing compares the temperature response caused by non-CO2 forcing with that by CO2 forcing.

  19. 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

    NASA Astrophysics Data System (ADS)

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

    2014-09-01

    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.

  20. 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

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

    2014-09-01

    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.

  1. 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

    SciTech Connect

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

    2014-09-15

    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.

  2. Examination of the Armagh Observatory Annual Mean Temperature Record, 1844-2004

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.; Hathaway, David H.

    2006-01-01

    The long-term annual mean temperature record (1844-2004) of the Armagh Observatory (Armagh, Northern Ireland, United Kingdom) is examined for evidence of systematic variation, in particular, as related to solar/geomagnetic forcing and secular variation. Indeed, both are apparent in the temperature record. Moving averages for 10 years of temperature are found to highly correlate against both 10-year moving averages of the aa-geomagnetic index and sunspot number, having correlation coefficients of approx. 0.7, inferring that nearly half the variance in the 10-year moving average of temperature can be explained by solar/geomagnetic forcing. The residuals appear episodic in nature, with cooling seen in the 1880s and again near 1980. Seven of the last 10 years of the temperature record has exceeded 10 C, unprecedented in the overall record. Variation of sunspot cyclic averages and 2-cycle moving averages of temperature strongly associate with similar averages for the solar/geomagnetic cycle, with the residuals displaying an apparent 9-cycle variation and a steep rise in temperature associated with cycle 23. Hale cycle averages of temperature for even-odd pairs of sunspot cycles correlate against similar averages for the solar/geomagnetic cycle and, especially, against the length of the Hale cycle. Indications are that annual mean temperature will likely exceed 10 C over the next decade.

  3. Mean body temperature does not modulate eccrine sweat rate during upright tilt.

    PubMed

    Wilson, Thad E; Cui, Jian; Crandall, Craig G

    2005-04-01

    Conflicting reports exist about the role of baroreflexes in efferent control of eccrine sweat rate. These conflicting reports may be due to differing mean body temperatures between studies. The purpose of this project was to test the hypothesis that mean body temperature modulates the effect of head-up tilt on sweat rate and skin sympathetic nerve activity (SSNA). To address this question, mean body temperature (0.9.internal temperature + 0.1.mean skin temperature), SSNA (microneurography of peroneal nerve, n = 8), and sweat rate (from an area innervated by the peroneal nerve and from two forearm sites, one perfused with neostigmine to augment sweating at lower mean body temperatures and the second with the vehicle, n = 12) were measured in 13 subjects during multiple 30 degrees head-up tilts during whole body heating. At the end of the heat stress, mean body temperature (36.8 +/- 0.1 to 38.0 +/- 0.1 degrees C) and sweat rate at all sites were significantly elevated. No significant correlations were observed between mean body temperature and the change in SSNA during head-up tilt (r = 0.07; P = 0.62), sweating within the innervated area (r = 0.06; P = 0.56), sweating at the neostigmine treated site (r = 0.04; P = 0.69), or sweating at the control site (r = 0.01; P = 0.94). Also, for each tilt throughout the heat stress, there were no significant differences in sweat rate (final tilt sweat rates were 0.69 +/- 0.11 and 0.68 +/- 0.11 mg.cm(-2).min(-1) within the innervated area; 1.04 +/- 0.16 and 1.06 +/- 0.16 mg.cm(-2).min(-1) at the neostigmine-treated site; and 0.85 +/- 0.15 and 0.85 +/- 0.15 mg.cm(-2).min(-1) at the control site, for supine and tilt, respectively). Hence, these data indicate that mean body temperature does not modulate eccrine sweat rate during baroreceptor unloading induced via 30 degrees head-up tilt.

  4. Long term mean annual water temperature for stream reaches in Pacific Northwest United States

    USGS Publications Warehouse

    ,

    2012-01-01

    Long-term mean annual water temperature (degrees Celsius) was estimated for the E2RF1 stream network (Brakebill and Terziotti, 2011) located within the Pacific Northwest region of the United States (HUC2 = 17; the Columbia River basin, the Puget Sound watershed, the coastal drainages of Washington and Oregon, and the closed basins in southern Oregon). Multiple linear regressions were used to select reach-scale watershed attributes (explanatory variables) for predicting the long-term mean annual water temperature (dependent variable) at a set of USGS water-quality monitoring stations. The results from the multiple linear regressions were used to predict the long-term mean water temperature for the Pacific Northwest reaches in the E2RF1 network.

  5. Scaling analysis of the mean and variariance of temperature in a developing thermal boundary layer

    NASA Astrophysics Data System (ADS)

    Byers, Clayton; Hultmark, Marcus

    2016-11-01

    A developing thermal boundary layer in a turbulent boundary layer is investigated both theoretically and experimentally. A scaling analysis of the mean temperature field and temperature variance, 1/2 θ2 , is developed by utilizing the "Asymptotic Invariance Principle" developed by George and Castillo (1997), including the possible effects of the Reynolds and Prandtl number. The derived solution for the inner and outer scaling is then used to develop a "heat transfer law" for the wall heat flux, qw. The condition of constant wall temperature is utilized, with an analysis of the temperature field treated as a passive scalar through ensuring the temperature differences remain small. Data collection is performed with a nanoscale temperature sensor, providing an improvement to performance over previous cold wire data acquisition. Supported by NSF (CBET-1510100 program manager Dimitrios Papavassiliou) and ONR (N00014-12-1-0875 and N00014-12-1-0962 program manager Ki-Han Kim).

  6. Water color affects the stratification, surface temperature, heat content, and mean epilimnetic irradiance of small lakes

    USGS Publications Warehouse

    Houser, J.N.

    2006-01-01

    The effects of water color on lake stratification, mean epilimnetic irradiance, and lake temperature dynamics were examined in small, north-temperate lakes that differed widely in water color (1.5-19.8 m -1). Among these lakes, colored lakes differed from clear lakes in the following ways: (i) the epilimnia were shallower and colder, and mean epilimnetic irradiance was reduced; (ii) the diel temperature cycles were more pronounced; (iii) whole-lake heat accumulation during stratification was reduced. The depth of the epilimnion ranged from 2.5 m in the clearest lake to 0.75 m in the most colored lake, and 91% of the variation in epilimnetic depth was explained by water color. Summer mean morning epilimnetic temperature was ???2??C cooler in the most colored lake compared with the clearest lake. In clear lakes, the diel temperature range (1.4 ?? 0.7??C) was significantly (p = 0.01) less than that in the most colored lake (2.1 ?? 1.0??C). Change in whole-lake heat content was negatively correlated with water color. Increasing water color decreased light penetration more than thermocline depth, leading to reduced mean epilimnetic irradiance in the colored lakes. Thus, in these small lakes, water color significantly affected temperature, thermocline depth, and light climate. ?? 2006 NRC.

  7. Finite temperature inelastic mean free path and quasiparticle lifetime in graphene

    NASA Astrophysics Data System (ADS)

    Li, Qiuzi; Das Sarma, S.

    2013-02-01

    We adopt the GW and random phase approximations to study finite temperature effects on the inelastic mean free path and quasiparticle lifetime by directly calculating the imaginary part of the finite temperature self-energy induced by electron-electron interaction in extrinsic and intrinsic graphene. In particular, we provide the density-dependent leading order temperature correction to the inelastic scattering rate for both single-layer and double-layer graphene systems. We find that the inelastic mean free path is strongly influenced by finite-temperature effects. We present the similarity and the difference between graphene with linear chiral band dispersion and conventional two-dimensional electron systems with parabolic band dispersion. We also compare the calculated finite temperature inelastic scattering length with the elastic scattering length due to Coulomb disorder and comment on the prospects for quantum interference effects showing up in low-density graphene transport. We also carry out inelastic scattering calculation for electron-phonon interaction, which by itself gives rather long carrier mean free paths and lifetimes since the deformation potential coupling is weak in graphene, and therefore electron-phonon interaction contributes significantly to the inelastic scattering only at relatively high temperatures.

  8. Time series modelling of global mean temperature for managerial decision-making.

    PubMed

    Romilly, Peter

    2005-07-01

    Climate change has important implications for business and economic activity. Effective management of climate change impacts will depend on the availability of accurate and cost-effective forecasts. This paper uses univariate time series techniques to model the properties of a global mean temperature dataset in order to develop a parsimonious forecasting model for managerial decision-making over the short-term horizon. Although the model is estimated on global temperature data, the methodology could also be applied to temperature data at more localised levels. The statistical techniques include seasonal and non-seasonal unit root testing with and without structural breaks, as well as ARIMA and GARCH modelling. A forecasting evaluation shows that the chosen model performs well against rival models. The estimation results confirm the findings of a number of previous studies, namely that global mean temperatures increased significantly throughout the 20th century. The use of GARCH modelling also shows the presence of volatility clustering in the temperature data, and a positive association between volatility and global mean temperature.

  9. Temperature measurement of mineral melt by means of a high-speed camera.

    PubMed

    Bizjan, Benjamin; Širok, Brane; Drnovšek, Janko; Pušnik, Igor

    2015-09-10

    This paper presents a temperature evaluation method by means of high-speed, visible light digital camera visualization and its application to the mineral wool production process. The proposed method adequately resolves the temperature-related requirements in mineral wool production and significantly improves the spatial and temporal resolution of measured temperature fields. Additionally, it is very cost effective in comparison with other non-contact temperature field measurement methods, such as infrared thermometry. Using the proposed method for temperatures between 800°C and 1500°C, the available temperature measurement range is approximately 300 K with a single temperature calibration point and without the need for camera setting adjustments. In the case of a stationary blackbody, the proposed method is able to produce deviations of less than 5 K from the reference (thermocouple-measured) temperature in a measurement range within 100 K from the calibration temperature. The method was also tested by visualization of rotating melt film in the rock wool production process. The resulting temperature fields are characterized by a very good temporal and spatial resolution (18,700 frames per second at 128  pixels×328  pixels and 8000 frames per second at 416  pixels×298  pixels).

  10. A regional neural network model for predicting mean daily river water temperature

    USGS Publications Warehouse

    Wagner, Tyler; DeWeber, Jefferson Tyrell

    2014-01-01

    Water temperature is a fundamental property of river habitat and often a key aspect of river resource management, but measurements to characterize thermal regimes are not available for most streams and rivers. As such, we developed an artificial neural network (ANN) ensemble model to predict mean daily water temperature in 197,402 individual stream reaches during the warm season (May–October) throughout the native range of brook trout Salvelinus fontinalis in the eastern U.S. We compared four models with different groups of predictors to determine how well water temperature could be predicted by climatic, landform, and land cover attributes, and used the median prediction from an ensemble of 100 ANNs as our final prediction for each model. The final model included air temperature, landform attributes and forested land cover and predicted mean daily water temperatures with moderate accuracy as determined by root mean squared error (RMSE) at 886 training sites with data from 1980 to 2009 (RMSE = 1.91 °C). Based on validation at 96 sites (RMSE = 1.82) and separately for data from 2010 (RMSE = 1.93), a year with relatively warmer conditions, the model was able to generalize to new stream reaches and years. The most important predictors were mean daily air temperature, prior 7 day mean air temperature, and network catchment area according to sensitivity analyses. Forest land cover at both riparian and catchment extents had relatively weak but clear negative effects. Predicted daily water temperature averaged for the month of July matched expected spatial trends with cooler temperatures in headwaters and at higher elevations and latitudes. Our ANN ensemble is unique in predicting daily temperatures throughout a large region, while other regional efforts have predicted at relatively coarse time steps. The model may prove a useful tool for predicting water temperatures in sampled and unsampled rivers under current conditions and future projections of climate

  11. Coherent variations of monthly mean total ozone and lower stratospheric temperature

    NASA Technical Reports Server (NTRS)

    Randel, William J.; Cobb, Janel B.

    1994-01-01

    Space-time patterns of correlation between total ozone and lower stratospheric temperature are documented, based on 14 years (1979-1992) of global monthly mean observations. Data are obtained from the total ozone mapping spectrometer (TOMS) and microwave sounding unit (MSU) channel 4, the latter being a weighted mean temperature of the 150- to 50-mbar layer. These data are analyzed (separately) for linear trend, solar cycle, quasi-biennial oscillation (QBO), and El Nino-Southern Oscillation (ENSO) variations via linear regression: significant signals are identified for each term, and the corresponding structures in ozone and temperature are found to be highly coherent. The temperature trends derived here show significant cooling of the lower stratosphere over Northern Hemisphere (NH) midlatitudes in winter-spring and over Antarctica in Southern Hemisphere (SH) spring; the overall space-time patterns are similar to those determined for ozone trends. Interestingly, temperatures do not decrease over SH midlatitudes during midwinter, in spite of large ozone losses. These data furthermore show globally coherent ozone and temperature perturbations associated with both QBO and ENSO variations; a new result here show large total ozone anomalies in middle-to-high latitudes of both hemispheres associated with ENSO events. Residuals from the ozone and temperature time series (defined as the deseasonalized total minus the regression fits) show strong positive correlation in middle-to-high latitudes but weak correlations in the trop ics. Time periods following the volcanic eruptions of El Chichon and Pinatubo are clearly identified from the coupled signatures of decreased ozone and increased temperature, opposite to the positive ozone-temperature correlations observed at other times. The ratios of ozone to temperature anomalies derived here show quantitative signatures indicating that either radiative (trend, solar, and QBO) or dynamical (ENSO and residuals) processes are

  12. Cryogenic, Absolute, High Pressure Sensor

    NASA Technical Reports Server (NTRS)

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

    2001-01-01

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

  13. Mean-field phase diagram of disordered bosons in a lattice at nonzero temperature

    NASA Astrophysics Data System (ADS)

    Krutitsky, K. V.; Pelster, A.; Graham, R.

    2006-09-01

    Bosons in a periodic lattice with on-site disorder at low but nonzero temperatures are considered within a mean-field theory. The criteria used for the definition of the superfluid, Mott insulator and Bose glass are analysed. Since the compressibility never vanishes at nonzero temperatures, it cannot be used as a general criterion. We show that the phases are unambiguously distinguished by the superfluid density and the density of states of the low-energy excitations. The phase diagram of the system is calculated. It is shown that even a tiny temperature leads to a significant shift of the boundary between the Bose glass and superfluid.

  14. Critical temperature for {alpha}-particle condensation within a momentum-projected mean-field approach

    SciTech Connect

    Sogo, T.; Roepke, G.; Lazauskas, R.

    2009-05-15

    {alpha}-particle (quartet) condensation in homogeneous spin-isospin symmetric nuclear matter is investigated. The usual Thouless criterion for the critical temperature is extended to the quartet case. The in-medium four-body problem is strongly simplified by the use of a momentum-projected mean-field ansatz for the quartet. The self-consistent single-particle wave functions are shown and discussed for various values of the density at the critical temperature. Excellent agreement of the critical temperature with a numerical solution of the Faddeev-Yakubovsky equation is obtained.

  15. Reduction of phonon mean free path: From low-temperature physics to room temperature applications in thermoelectricity

    NASA Astrophysics Data System (ADS)

    Bourgeois, Olivier; Tainoff, Dimitri; Tavakoli, Adib; Liu, Yanqing; Blanc, Christophe; Boukhari, Mustapha; Barski, André; Hadji, Emmanuel

    2016-12-01

    It has been proposed for a long time now that the reduction of the thermal conductivity by reducing the phonon mean free path is one of the best way to improve the current performance of thermoelectrics. By measuring the thermal conductance and thermal conductivity of nanowires and thin films, we show different ways of increasing the phonon scattering from low-temperature up to room-temperature experiments. It is shown that playing with the geometry (constriction, periodic structures, nano-inclusions), from the ballistic to the diffusive limit, the phonon thermal transport can be severely altered in single crystalline semiconducting structures; the phonon mean free path is in consequence reduced. The diverse implications on thermoelectric properties will be eventually discussed.

  16. Use of ice cores from glaciers with melting for reconstructing mean summer temperature variations

    NASA Astrophysics Data System (ADS)

    Nakazawa, Fumio; Fujita, Koji

    This study examines a new method for reconstructing mean summer temperature variations by using an ice core from a wet-snow zone on a summer-accumulation-type glacier. In July 2001, a 25.1 m deep ice core was recovered from the accumulation area of Sofiyskiy glacier (49°47‧ N, 87°43‧ E; 3435 m a.s.l.), located in the southern Chuyskiy range of the Russian Altai mountains, and a 4.5 m deep pit was excavated about 50 m northwest of the drill site. The observation site has a positive balance even during summer when melting occurs. The summer balance for each year from 1990 to 2000 was estimated from Pinaceae and Artemisia pollen peaks in these samples. Pinaceae pollen marks spring, whereas Artemisia pollen marks autumn. Moreover, meltwater intrusion did not reach the previous year's accumulation. Thus, the ice between these pollen peaks in the same year was used to estimate a summer balance. The reconstructed summer balance variations were negatively correlated with mean summer temperature variations (r = -0.72, P < 0.05). This study shows that, for summer-accumulation-type glaciers such as Sofiyskiy glacier, the most important climate factor controlling the glacier's surface mass balance is mean summer temperature. Therefore, the summer layer thickness in an ice core can be used as a proxy for reconstructing mean summer temperature variations.

  17. Daily Mean Temperature Affects Urolithiasis Presentation in Seoul: a Time-series Analysis.

    PubMed

    Lee, SeoYeon; Kim, Min-Su; Kim, Jung Hoon; Kwon, Jong Kyou; Chi, Byung Hoon; Kim, Jin Wook; Chang, In Ho

    2016-05-01

    This study aimed to investigate the overall cumulative exposure-response and the lag response relationships between daily temperature and urolithiasis presentation in Seoul. Using a time-series design and distributing lag nonlinear methods, we estimated the relative risk (RR) of urolithiasis presentation associated with mean daily temperature, including the cumulative RR for a 20 days period, and RR for individual daily lag through 20 days. We analyzed data from 14,518 patients of 4 hospitals emergency department who sought medical evaluation or treatment of urolithiasis from 2005-2013 in Seoul. RR was estimated according to sex and age. Associations between mean daily temperature and urolithiasis presentation were not monotonic. Furthermore, there was variation in the exposure-response curve shapes and the strength of association at different temperatures, although in most cases RRs increased for temperatures above the 13°C reference value. The RRs for urolothiasis at 29°C vs. 13°C were 2.54 in all patients (95% confidence interval [CI]: 1.67-3.87), 2.59 in male (95% CI, 1.56-4.32), 2.42 in female (95% CI, 1.15-5.07), 3.83 in male less than 40 years old (95% CI, 1.78-8.26), and 2.47 in male between 40 and 60 years old (95% CI, 1.15-5.34). Consistent trends of increasing RR of urolithiasis presentation were observed within 5 days of high temperatures across all groups. Urolithiasis presentation increased with high temperature with higher daily mean temperatures, with the strongest associations estimated for lags of only a few days, in Seoul, a metropolitan city in Korea.

  18. Daily Mean Temperature Affects Urolithiasis Presentation in Seoul: a Time-series Analysis

    PubMed Central

    2016-01-01

    This study aimed to investigate the overall cumulative exposure-response and the lag response relationships between daily temperature and urolithiasis presentation in Seoul. Using a time-series design and distributing lag nonlinear methods, we estimated the relative risk (RR) of urolithiasis presentation associated with mean daily temperature, including the cumulative RR for a 20 days period, and RR for individual daily lag through 20 days. We analyzed data from 14,518 patients of 4 hospitals emergency department who sought medical evaluation or treatment of urolithiasis from 2005-2013 in Seoul. RR was estimated according to sex and age. Associations between mean daily temperature and urolithiasis presentation were not monotonic. Furthermore, there was variation in the exposure-response curve shapes and the strength of association at different temperatures, although in most cases RRs increased for temperatures above the 13°C reference value. The RRs for urolothiasis at 29°C vs. 13°C were 2.54 in all patients (95% confidence interval [CI]: 1.67-3.87), 2.59 in male (95% CI, 1.56-4.32), 2.42 in female (95% CI, 1.15-5.07), 3.83 in male less than 40 years old (95% CI, 1.78-8.26), and 2.47 in male between 40 and 60 years old (95% CI, 1.15-5.34). Consistent trends of increasing RR of urolithiasis presentation were observed within 5 days of high temperatures across all groups. Urolithiasis presentation increased with high temperature with higher daily mean temperatures, with the strongest associations estimated for lags of only a few days, in Seoul, a metropolitan city in Korea. PMID:27134497

  19. Errors of five-day mean surface wind and temperature conditions due to inadequate sampling

    NASA Technical Reports Server (NTRS)

    Legler, David M.

    1991-01-01

    Surface meteorological reports of wind components, wind speed, air temperature, and sea-surface temperature from buoys located in equatorial and midlatitude regions are used in a simulation of random sampling to determine errors of the calculated means due to inadequate sampling. Subsampling the data with several different sample sizes leads to estimates of the accuracy of the subsampled means. The number N of random observations needed to compute mean winds with chosen accuracies of 0.5 (N sub 0.5) and 1.0 (N sub 1,0) m/s and mean air and sea surface temperatures with chosen accuracies of 0.1 (N sub 0.1) and 0.2 (N sub 0.2) C were calculated for each 5-day and 30-day period in the buoy datasets. Mean values of N for the various accuracies and datasets are given. A second-order polynomial relation is established between N and the variability of the data record. This relationship demonstrates that for the same accuracy, N increases as the variability of the data record increases. The relationship is also independent of the data source. Volunteer-observing ship data do not satisfy the recommended minimum number of observations for obtaining 0.5 m/s and 0.2 C accuracy for most locations. The effect of having remotely sensed data is discussed.

  20. Contributed Review: Absolute spectral radiance calibration of fiber-optic shock-temperature pyrometers using a coiled-coil irradiance standard lamp

    NASA Astrophysics Data System (ADS)

    Fat'yanov, O. V.; Asimow, P. D.

    2015-10-01

    We describe an accurate and precise calibration procedure for multichannel optical pyrometers such as the 6-channel, 3-ns temporal resolution instrument used in the Caltech experimental geophysics laboratory. We begin with a review of calibration sources for shock temperatures in the 3000-30 000 K range. High-power, coiled tungsten halogen standards of spectral irradiance appear to be the only practical alternative to NIST-traceable tungsten ribbon lamps, which are no longer available with large enough calibrated area. However, non-uniform radiance complicates the use of such coiled lamps for reliable and reproducible calibration of pyrometers that employ imaging or relay optics. Careful analysis of documented methods of shock pyrometer calibration to coiled irradiance standard lamps shows that only one technique, not directly applicable in our case, is free of major radiometric errors. We provide a detailed description of the modified Caltech pyrometer instrument and a procedure for its absolute spectral radiance calibration, accurate to ±5%. We employ a designated central area of a 0.7× demagnified image of a coiled-coil tungsten halogen lamp filament, cross-calibrated against a NIST-traceable tungsten ribbon lamp. We give the results of the cross-calibration along with descriptions of the optical arrangement, data acquisition, and processing. We describe a procedure to characterize the difference between the static and dynamic response of amplified photodetectors, allowing time-dependent photodiode correction factors for spectral radiance histories from shock experiments. We validate correct operation of the modified Caltech pyrometer with actual shock temperature experiments on single-crystal NaCl and MgO and obtain very good agreement with the literature data for these substances. We conclude with a summary of the most essential requirements for error-free calibration of a fiber-optic shock-temperature pyrometer using a high-power coiled tungsten halogen

  1. Contributed Review: Absolute spectral radiance calibration of fiber-optic shock-temperature pyrometers using a coiled-coil irradiance standard lamp

    SciTech Connect

    Fat’yanov, O. V. Asimow, P. D.

    2015-10-15

    We describe an accurate and precise calibration procedure for multichannel optical pyrometers such as the 6-channel, 3-ns temporal resolution instrument used in the Caltech experimental geophysics laboratory. We begin with a review of calibration sources for shock temperatures in the 3000-30 000 K range. High-power, coiled tungsten halogen standards of spectral irradiance appear to be the only practical alternative to NIST-traceable tungsten ribbon lamps, which are no longer available with large enough calibrated area. However, non-uniform radiance complicates the use of such coiled lamps for reliable and reproducible calibration of pyrometers that employ imaging or relay optics. Careful analysis of documented methods of shock pyrometer calibration to coiled irradiance standard lamps shows that only one technique, not directly applicable in our case, is free of major radiometric errors. We provide a detailed description of the modified Caltech pyrometer instrument and a procedure for its absolute spectral radiance calibration, accurate to ±5%. We employ a designated central area of a 0.7× demagnified image of a coiled-coil tungsten halogen lamp filament, cross-calibrated against a NIST-traceable tungsten ribbon lamp. We give the results of the cross-calibration along with descriptions of the optical arrangement, data acquisition, and processing. We describe a procedure to characterize the difference between the static and dynamic response of amplified photodetectors, allowing time-dependent photodiode correction factors for spectral radiance histories from shock experiments. We validate correct operation of the modified Caltech pyrometer with actual shock temperature experiments on single-crystal NaCl and MgO and obtain very good agreement with the literature data for these substances. We conclude with a summary of the most essential requirements for error-free calibration of a fiber-optic shock-temperature pyrometer using a high-power coiled tungsten halogen

  2. Fundamental limitations of noninvasive temperature imaging by means of ultrasound echo strain estimation.

    PubMed

    Miller, Naomi R; Bamber, Jeffrey C; Meaney, Paul M

    2002-10-01

    Ultrasonic estimation of temperature-induced echo strain has been suggested as a means of predicting the location of thermal lesions formed by focused ultrasound (US) surgery before treatment. Preliminary investigations of this technique have produced optimistic results because they were carried out with rubber phantoms and used room temperature, rather than body temperature, as the baseline. The objective of the present study was to determine, through modelling, the likely feasibility of using ultrasonic temperature imaging to detect and localise the focal region of the heating beam for a medium with a realistic temperature-dependence of sound speed subjected to a realistic temperature rise. We determined the minimum ultrasonic signal-to-noise ratio (SNR) required to visualise the heated region for liver of varying fat content. Due to the small (0.5%) change in sound speed at the focus, the threshold SNR for normal liver (low fat content) was found to be at least 20 dB. This implies that temperature imaging in this tissue type will only be feasible if the effects of electronic noise can be minimised and if other sources of noise, such as cardiac-induced motion, do not substantially reduce the visibility of the focal region. For liver of intermediate fat content, the heated region could not be visualised even when the echo data were noise-free. Tissues with a very high fat content are likely to represent the most favourable conditions for ultrasonic temperature imaging.

  3. Assimilating continental mean temperatures to reconstruct the climate of the late pre-industrial period

    NASA Astrophysics Data System (ADS)

    Matsikaris, Anastasios; Widmann, Martin; Jungclaus, Johann

    2016-06-01

    An on-line, ensemble-based data assimilation (DA) method is performed to reconstruct the climate for 1750-1850 AD, and the performance is evaluated on large and small spatial scales. We use a low-resolution version of the Max Planck Institute for Meteorology MPI-ESM model and assimilate the PAGES 2K continental mean temperature reconstructions for the Northern Hemisphere (NH). The ensembles are generated sequentially for sub-periods based on the analysis of previous sub-periods. The assimilation has good skill for large-scale temperatures, but there is no agreement between the DA analysis and proxy-based reconstructions for small-scale temperature patterns within Europe or with reconstructions for the North Atlantic Oscillation (NAO) index. To explain the lack of added value in small spatial scales, a maximum covariance analysis (MCA) of links between NH temperature and sea level pressure is performed based on a control simulation with MPI-ESM. For annual values, winter and spring the Northern Annular Mode (NAM) is the pattern that is most closely linked to the NH continental temperatures, while for summer and autumn it is a wave-like pattern. This link is reproduced in the DA for winter, spring and annual means, providing potential for constraining the NAM/NAO phase and in turn regional temperature variability. It is shown that the lack of actual small-scale skill is likely due to the fact that the link might be too weak, as the NH continental mean temperatures are not the best predictors for large-scale circulation anomalies, or that the PAGES 2K temperatures include noise. Both factors can lead to circulation anomalies in the DA analysis that are substantially different from reality, leading to unrealistic representation of small-scale temperature variability. Moreover, we show that even if the true amplitudes of the leading MCA circulation patterns were known, there is still a large amount of unexplained local temperature variance. Based on these results, we

  4. Second Law Violations by Means of a Stratification of Temperature Due to Force Fields

    NASA Astrophysics Data System (ADS)

    Trupp, Andreas

    2002-11-01

    In 1868 J.C. Maxwell proved that a perpetual motion machine of the second kind would become possible, if the equilibrium temperature in a vertical column of gas subject to gravity were a function of height. However, Maxwell had claimed that the temperature had to be the same at all points of the column. So did Boltzmann. Their opponent was Loschmidt. He claimed that the equilibrium temperature declined with height, and that a perpetual motion machine of the second kind operating by means of such column was compatible with the second law of thermodynamics. Extending the general idea behind Loschmidt's concept to other force fields, gravity can be replaced by molecular forces acting on molecules that try to escape from the surface of a liquid into the vapor space. Experiments proving the difference of temperature between the liquid and the vapor phase were conducted in the 19th century already.

  5. Increases in both temperature means and extremes likely facilitate invasive herbivore outbreaks

    PubMed Central

    Ju, Rui-Ting; Zhu, Hai-Yan; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2015-01-01

    Although increases in mean temperature (MT) and extreme high temperature (EHT) can greatly affect population dynamics of insects under global warming, how concurrent changes in both MT and EHT affect invasive species is largely unknown. We used four thermal regimes to simulate the increases in summer temperature and compared their effects on the life-history traits of three geographical populations (Chongqing, Wuhan and Shanghai) of an invasive insect, Corythucha ciliata, in China. The four thermal regimes were control (i.e., natural or ambient), an increase in MT (IMT), an increase in EHT, and a combination of IMT + EHT. We found that the three warming regimes significantly increased the developmental rate but did not affect the survival, sex ratio, longevity, or fecundity of C. ciliata. Consequently, the intrinsic rate of natural increase (rm) was enhanced and the number of days required for population doubling (t) was reduced by the warming regimes. The demographic parameters did not significantly differ among the three populations. These results indicate that population size of C. ciliata may be enhanced by increases in both temperature means and extremes. The increases in summer temperature associated with climate change, therefore, would likely facilitate population outbreaks of some thermophilic invasive insects. PMID:26502826

  6. Increases in both temperature means and extremes likely facilitate invasive herbivore outbreaks.

    PubMed

    Ju, Rui-Ting; Zhu, Hai-Yan; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2015-10-27

    Although increases in mean temperature (MT) and extreme high temperature (EHT) can greatly affect population dynamics of insects under global warming, how concurrent changes in both MT and EHT affect invasive species is largely unknown. We used four thermal regimes to simulate the increases in summer temperature and compared their effects on the life-history traits of three geographical populations (Chongqing, Wuhan and Shanghai) of an invasive insect, Corythucha ciliata, in China. The four thermal regimes were control (i.e., natural or ambient), an increase in MT (IMT), an increase in EHT, and a combination of IMT + EHT. We found that the three warming regimes significantly increased the developmental rate but did not affect the survival, sex ratio, longevity, or fecundity of C. ciliata. Consequently, the intrinsic rate of natural increase (rm) was enhanced and the number of days required for population doubling (t) was reduced by the warming regimes. The demographic parameters did not significantly differ among the three populations. These results indicate that population size of C. ciliata may be enhanced by increases in both temperature means and extremes. The increases in summer temperature associated with climate change, therefore, would likely facilitate population outbreaks of some thermophilic invasive insects.

  7. Increases in both temperature means and extremes likely facilitate invasive herbivore outbreaks

    NASA Astrophysics Data System (ADS)

    Ju, Rui-Ting; Zhu, Hai-Yan; Gao, Lei; Zhou, Xu-Hui; Li, Bo

    2015-10-01

    Although increases in mean temperature (MT) and extreme high temperature (EHT) can greatly affect population dynamics of insects under global warming, how concurrent changes in both MT and EHT affect invasive species is largely unknown. We used four thermal regimes to simulate the increases in summer temperature and compared their effects on the life-history traits of three geographical populations (Chongqing, Wuhan and Shanghai) of an invasive insect, Corythucha ciliata, in China. The four thermal regimes were control (i.e., natural or ambient), an increase in MT (IMT), an increase in EHT, and a combination of IMT + EHT. We found that the three warming regimes significantly increased the developmental rate but did not affect the survival, sex ratio, longevity, or fecundity of C. ciliata. Consequently, the intrinsic rate of natural increase (rm) was enhanced and the number of days required for population doubling (t) was reduced by the warming regimes. The demographic parameters did not significantly differ among the three populations. These results indicate that population size of C. ciliata may be enhanced by increases in both temperature means and extremes. The increases in summer temperature associated with climate change, therefore, would likely facilitate population outbreaks of some thermophilic invasive insects.

  8. High temperature attack of ores by means of a liquor essentially containing a soluble bicarbonate

    SciTech Connect

    Bosca, B.; Maurel, P.; Nicolas, F.

    1981-10-20

    A process for the oxidizing attack at high temperature of ores containing at least one metal belonging to the group formed by uranium, vanadium and molybdenum, by means of an aqueous liquor containing a majority of sodium bicarbonate and a minority of sodium carbonate according to a ratio by weight of sodium bicarbonate to sodium carbonate of at least 1.5, in the presence of free oxygen injected into the reaction medium, this medium being maintained at a temperature of between 160/sup 0/C and 300/sup 0/C. For at most six hours.

  9. The Quantitative Relationship Between ISO 15197 Accuracy Criteria and Mean Absolute Relative Difference (MARD) in the Evaluation of Analytical Performance of Self-Monitoring of Blood Glucose (SMBG) Systems.

    PubMed

    Pardo, Scott; Simmons, David A

    2016-09-01

    The relationship between International Organization for Standardization (ISO) accuracy criteria and mean absolute relative difference (MARD), 2 methods for assessing the accuracy of blood glucose meters, is complex. While lower MARD values are generally better than higher MARD values, it is not possible to define a particular MARD value that ensures a blood glucose meter will satisfy the ISO accuracy criteria. The MARD value that ensures passing the ISO accuracy test can be described only as a probabilistic range. In this work, a Bayesian model is presented to represent the relationship between ISO accuracy criteria and MARD. Under the assumptions made in this work, there is nearly a 100% chance of satisfying ISO 15197:2013 accuracy requirements if the MARD value is between 3.25% and 5.25%.

  10. Absolute airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Baumann, Henri

    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

  11. Assimilating Continental Mean Temperatures to Reconstruct the Climate of the Late Pre-industrial Period

    NASA Astrophysics Data System (ADS)

    Matsikaris, A.; Widmann, M.; Jungclaus, J. H.

    2015-12-01

    Climate reconstructions for the pre-instrumental period are either based on climate proxy data or on numerical simulations. However, both approaches are associated with substantial uncertainties. In principle, the best state estimates can be expected by employing data assimilation (DA) techniques, which systematically combine the empirical information from proxy data with the representation of the processes that govern the climate system given by climate models. Here, an ensemble-based DA method is performed to reconstruct the climate of the period 1750-1850 AD, and the performance is evaluated on large and small spatial scales. We use a low-resolution version of the Max Planck Institute for Meteorology's MPI-ESM model and assimilate the PAGES 2K continental mean temperature reconstructions for the Northern Hemisphere (NH). The ensembles are generated sequentially for sub-periods based on the analysis of previous sub-periods. The assimilation has good skill for large-scale temperatures, but there is no agreement between the DA analysis and proxy-based reconstructions for small-scale temperature variability within Europe or with reconstructions for the North Atlantic Oscillation (NAO) index. To explain the lack of added value in the DA, a Maximum Covariance Analysis (MCA) of links between NH temperature and sea level pressure (SLP) is performed on a control run with MPI-ESM. The analysis shows that the Northern Annular Mode (NAM) is the pattern that is most closely linked to the NH continental temperatures. This link is reproduced in the assimilation run for winter, spring and annual means, providing potential for constraining the NAM/NAO phase and in turn, for regional temperature variability in the DA. It is shown that the lack of actual skill for these aspects is likely due to the fact that either the link might be too weak, as the continental mean temperatures are not the best predictors for the NAM (they are reconstructed by many proxies in locations not linked

  12. Oxygen isotope ratios in trees reflect mean annual temperature and humidity.

    PubMed

    Burk, R L; Stuiver, M

    1981-03-27

    Values of the oxygen isotope ratios (delta(18)O) in tree-ring cellulose closely reflect the delta(18)O values in atmospheric precipitation and hence mean annual temperature. The change in delta(18)O in cellulose is 0.41 per mil per degree Celsius for selected near-coastal stations. The values of delta(18)O in precipitation and cellulose also change with altitude, as demonstrated for Mount Rainier, Washington. A temperature lapse rate of 5.2 degrees +/- 0.5 degrees C per 1000 meters calculated from cellulose delta(18)O values agrees with the accepted mean annual lapse rate of 5 degrees C per 1000 meters for this region. Cellulose delta(18)O values and delta(18)O values of carbon dioxide equilibrated with leaf water differ by a fixed 16 per mil.

  13. Oxygen isotope ratios in trees reflect mean annual temperature and humidity

    SciTech Connect

    Burk, R.L.; Stuiver, M.

    1981-03-27

    Values of the oxygen isotope ratios (delta/sup 18/O) in tree-ring cellulose closely reflect the delta/sup 18/O values in atmospheric precipitation and hence mean annual temperature. The change in delta/sup 18/O in cellulose is 0.41 per mil per degree Celsius for selected near-coastal stations. The values of delta/sup 18/O in precipitation and cellulose also change with altitude, as demonstrated for Mount Rainier, Washington. A temperature lapse rate of 5.2/sup 0/ +/- 0.5/sup 0/C per 1000 meters calculated from cellulose delta/sup 18/O values agrees with the accepted mean annual lapse rate of 5/sup 0/C per 1000 meters for this region. Cellulose delta/sup 18/O values and delta/sup 18/O values of carbon dioxide equilibrated with leaf water differ by a fixed 16 per mil.

  14. Oxygen isotope ratios in trees reflect mean annual temperature and humidity

    SciTech Connect

    Burk, R.L.; Stuiver, M.

    1981-03-27

    Values of the oxygen isotope ratios (delta/sup 18/O) in tree-ring cellulose closely reflect the delta/sup 18/O values in atmospheric precipitation and hence mean annual temperature. The change in delta/sup 18/O in cellulose is 0.41 per mil per degree Celsius for selected near-coastal stations. The values of delta/sup 18/O in precipitation and cellulose also change with altitude, as demonstrated for Mount Rainier, Washington. A temperature lapse rate of 5.2/sup 0/ per 1000 meters calculated from cellulose delta/sup 18/O values agrees with the accepted mean annual lapse rate of 5/sup 0/C per 1000 meters for this region.

  15. Mean velocity and temperature profiles in a sheared diabatic turbulent boundary layer

    NASA Astrophysics Data System (ADS)

    Li, Dan; Katul, Gabriel G.; Bou-Zeid, Elie

    2012-10-01

    In the atmospheric surface layer, modifications to the logarithmic mean velocity and air temperature profiles induced by thermal stratification or convection are accounted for via stability correction functions ϕm and ϕh, respectively, that vary with the stability parameter ς. These two stability correction functions are presumed to be universal in shape and independent of the surface characteristics. To date, there is no phenomenological theory that explains all the scaling laws in ϕh with ς, how ϕh relates to ϕm, and why ϕh ⩽ ϕm is consistently reported. To develop such a theory, the recently proposed links between the mean velocity profile and the Kolmogorov spectrum of turbulence, which were previously modified to account for the effects of buoyancy, are generalized here to include the mean air temperature profile. The resulting theory explains the observed scaling laws in ϕm and ϕh reported in many field and numerical experiments, predicts their behaviors across a wide range of atmospheric stability conditions, and elucidates why heat is transported more efficiently than momentum in certain stability regimes. In particular, it is shown that the enhancement in heat transport under unstable conditions is linked to a "scale-resonance" between turnover eddies and excursions in the instantaneous air temperature profiles. Excluding this scale-resonance results in the conventional Reynolds analogy with ϕm = ϕh across all stability conditions.

  16. Solar Cycle Variability in Mean Thermospheric Composition and Temperature Induced by Atmospheric Tides

    NASA Astrophysics Data System (ADS)

    Jones, M., Jr.; Forbes, J. M.; Hagan, M. E.

    2015-12-01

    Vertically-propagating atmospheric thermal tides whose origins lie in Earth's lower atmosphere are now widely recognized as one of the dominant "meteorological" drivers of space weather. Many prior research efforts have focused on documenting and understanding the role that dissipating tides play in determining the longitudinal and seasonal variability associated with lower thermospheric winds, temperature, and constituent densities. However, considerably less attention has focused on understanding the potential solar cycle variability in the mean thermospheric state induced by the tides. In this paper we utilize the National Center for Atmospheric Research Thermosphere-Ionosphere-Electrodynamics General Circulation Model (TIE-GCM), forced with observationally-based tides at the model lower boundary from the Climatological Tidal Model of the Thermosphere (CTMT, from Oberheide et al. [2011]), to elucidate how the dissipating tides induce variations of up to 30 K in the zonal-mean thermosphere temperature between solar minimum and maximum. Numerical experiments are performed for the month of September and for solar minimum, medium, and maximum conditions in order to quantify the solar cycle variability associated with the different terms in the thermodynamic energy, major and minor neutral constituent continuity equations. Our analysis indicates that solar cycle variability in neutral temperatures results from a combination of net eddy heat transport effects and tidal modulation of net nitric oxide (NO) cooling. The chemical and dynamical pathways through which dissipating tides affect mean NO cooling differently at solar minimum and maximum are diagnosed.

  17. On Statistical Methods for Common Mean and Reference Confidence Intervals in Interlaboratory Comparisons for Temperature

    NASA Astrophysics Data System (ADS)

    Witkovský, Viktor; Wimmer, Gejza; Ďuriš, Stanislav

    2015-08-01

    We consider a problem of constructing the exact and/or approximate coverage intervals for the common mean of several independent distributions. In a metrological context, this problem is closely related to evaluation of the interlaboratory comparison experiments, and in particular, to determination of the reference value (estimate) of a measurand and its uncertainty, or alternatively, to determination of the coverage interval for a measurand at a given level of confidence, based on such comparison data. We present a brief overview of some specific statistical models, methods, and algorithms useful for determination of the common mean and its uncertainty, or alternatively, the proper interval estimator. We illustrate their applicability by a simple simulation study and also by example of interlaboratory comparisons for temperature. In particular, we shall consider methods based on (i) the heteroscedastic common mean fixed effect model, assuming negligible laboratory biases, (ii) the heteroscedastic common mean random effects model with common (unknown) distribution of the laboratory biases, and (iii) the heteroscedastic common mean random effects model with possibly different (known) distributions of the laboratory biases. Finally, we consider a method, recently suggested by Singh et al., for determination of the interval estimator for a common mean based on combining information from independent sources through confidence distributions.

  18. Monthly mean global climatology of temperature, wind, geopotential height and pressure for 0-120 km

    NASA Technical Reports Server (NTRS)

    Chandra, Sushil; Schoeberl, Mark R.; Fleming, Eric L.; Barnett, John J.

    1990-01-01

    This paper presents a monthly mean climatology of zonal mean temperature, zonal wind, and geopotential height with nearly pole-to-pole coverage (80 deg S-80 deg N) for 0-120 km which can be used as a function of altitude and pressure. This climatology reproduces most of the characteristic features of the atmosphere such as the lowering and cooling of the mesopause and the lowering and warming of the stratopause during the summer months at high latitudes. A series of zonal wind profiles is also presented comparing this climatological wind with monthly mean climatological direct wind measurements in the upper mesosphere and lower thermosphere. The two data sets compare well below 80 km, with some general seasonal trend agreement observed above 80 km. The zonal wind at the equator presented here simulates the observed features of the semiannual oscillation in the upper stratosphere and mesosphere.

  19. Efficiencies of power plants, quasi-static models and the geometric-mean temperature

    NASA Astrophysics Data System (ADS)

    Johal, Ramandeep S.

    2017-02-01

    Observed efficiencies of industrial power plants are often approximated by the square-root formula: 1 - √T-/T+, where T+(T-) is the highest (lowest) temperature achieved in the plant. This expression can be derived within finite-time thermodynamics, or, by entropy generation minimization, based on finite rates for the processes. In these analyses, a closely related quantity is the optimal value of the intermediate temperature for the hot stream, given by the geometric-mean value: √T+/T-. In this paper, instead of finite-time models, we propose to model the operation of plants by quasi-static work extraction models, with one reservoir (source/sink) as finite, while the other as practically infinite. No simplifying assumption is made on the nature of the finite system. This description is consistent with two model hypotheses, each yielding a specific value of the intermediate temperature, say T1 and T2. The lack of additional information on validity of the hypothesis that may be actually realized, motivates to approach the problem as an exercise in inductive inference. Thus we define an expected value of the intermediate temperature as the equally weighted mean: (T1 + T2)/2. It is shown that the expected value is very closely given by the geometric-mean value for almost all of the observed power plants.

  20. Long-range persistence in the global mean surface temperature and the global warming "time bomb"

    NASA Astrophysics Data System (ADS)

    Rypdal, M.; Rypdal, K.

    2012-04-01

    Detrended Fluctuation Analysis (DFA) and Maximum Likelihood Estimations (MLE) based on instrumental data over the last 160 years indicate that there is Long-Range Persistence (LRP) in Global Mean Surface Temperature (GMST) on time scales of months to decades. The persistence is much higher in sea surface temperature than in land temperatures. Power spectral analysis of multi-model, multi-ensemble runs of global climate models indicate further that this persistence may extend to centennial and maybe even millennial time-scales. We also support these conclusions by wavelet variogram analysis, DFA, and MLE of Northern hemisphere mean surface temperature reconstructions over the last two millennia. These analyses indicate that the GMST is a strongly persistent noise with Hurst exponent H>0.9 on time scales from decades up to at least 500 years. We show that such LRP can be very important for long-term climate prediction and for the establishment of a "time bomb" in the climate system due to a growing energy imbalance caused by the slow relaxation to radiative equilibrium under rising anthropogenic forcing. We do this by the construction of a multi-parameter dynamic-stochastic model for the GMST response to deterministic and stochastic forcing, where LRP is represented by a power-law response function. Reconstructed data for total forcing and GMST over the last millennium are used with this model to estimate trend coefficients and Hurst exponent for the GMST on multi-century time scale by means of MLE. Ensembles of solutions generated from the stochastic model also allow us to estimate confidence intervals for these estimates.

  1. Of mast and mean: differential-temperature cue makes mast seeding insensitive to climate change.

    PubMed

    Kelly, Dave; Geldenhuis, Andre; James, Alex; Penelope Holland, E; Plank, Michael J; Brockie, Robert E; Cowan, Philip E; Harper, Grant A; Lee, William G; Maitland, Matt J; Mark, Alan F; Mills, James A; Wilson, Peter R; Byrom, Andrea E

    2013-01-01

    Mast-seeding plants often produce high seed crops the year after a warm spring or summer, but the warm-temperature model has inconsistent predictive ability. Here, we show for 26 long-term data sets from five plant families that the temperature difference between the two previous summers (ΔT) better predicts seed crops. This discovery explains how masting species tailor their flowering patterns to sites across altitudinal temperature gradients; predicts that masting will be unaffected by increasing mean temperatures under climate change; improves prediction of impacts on seed consumers; demonstrates that strongly masting species are hypersensitive to climate; explains the rarity of consecutive high-seed years without invoking resource constraints; and generates hypotheses about physiological mechanisms in plants and insect seed predators. For plants, ΔT has many attributes of an ideal cue. This temperature-difference model clarifies our understanding of mast seeding under environmental change, and could also be applied to other cues, such as rainfall.

  2. Room temperature screening of thermal conductivity by means of thermal transient measurements

    NASA Astrophysics Data System (ADS)

    García-Cañadas, Jorge; Cheng, Shudan; Márquez-García, Lourdes; Prest, Martin J.; Akbari-Rahimabadi, Ahmad; Min, Gao

    2016-10-01

    A proof of concept of the possibility to estimate thermal conductivity of bulk disc samples at room temperature by means of thermal decays is demonstrated. An experimental set-up was designed and fabricated, which is able to perform thermal transient measurements by using a specially designed multifunctional probe that has the ability to measure temperature at its tip. Initially, the probe is heated by a heater coil located in its interior until the tip temperature reaches a steady state. Then, the probe is contacted with a disc sample which produces a temperature decay until a new state is reached. The difference between the initial and final states temperatures shows a correlation with the thermal conductivity of the sample. Employing a calibration equation, obtained using reference materials, the thermal conductivity can be calculated. Reasonably good random and systematic errors (<13% and ~9% respectively) are obtained. Theoretical simulations performed using COMSOL show a good qualitative agreement with experimental results. This new method involves an inexpensive and simple set-up which can be especially useful for thermal conductivity screening and high-throughput measurements.

  3. Comparison of different methods of estimating the mean radiant temperature in outdoor thermal comfort studies.

    PubMed

    Krüger, E L; Minella, F O; Matzarakis, A

    2014-10-01

    Correlations between outdoor thermal indices and the calculated or measured mean radiant temperature T(mrt) are in general of high importance because of the combined effect on human energy balance in outdoor spaces. The most accurate way to determine T(mrt) is by means of integral radiation measurements, i.e. measuring the short- and long-wave radiation from six directions using pyranometers and pyrgeometers, an expensive and not always an easily available procedure. Some studies use globe thermometers combined with air temperature and wind speed sensors. An alternative way to determine T(mrt) is based on output from the RayMan model from measured data of incoming global radiation and morphological features of the monitoring site in particular sky view factor (SVF) data. The purpose of this paper is to compare different methods to assess the mean radiant temperature T(mrt) in terms of differences to a reference condition (T(mrt) calculated from field measurements) and to resulting outdoor comfort levels expressed as PET and UTCI values. The T(mrt) obtained from field measurements is a combination of air temperature, wind speed and globe temperature data according to the forced ventilation formula of ISO 7726 for data collected in Glasgow, UK. Four different methods were used in the RayMan model for T(mrt) calculations: input data consisting exclusively of data measured at urban sites; urban data excluding solar radiation, estimated SVF data and solar radiation data measured at a rural site; urban data excluding solar radiation with SVF data for each site; urban data excluding solar radiation and including solar radiation at the rural site taking no account of SVF information. Results show that all methods overestimate T(mrt) when compared to ISO calculations. Correlations were found to be significant for the first method and lower for the other three. Results in terms of comfort (PET, UTCI) suggest that reasonable estimates could be made based on global radiation

  4. A PV view of the zonal mean distribution of temperature and wind in the extratropical troposphere

    NASA Technical Reports Server (NTRS)

    Sun, De-Zheng; Lindzen, Richard S.

    1994-01-01

    The dependence of the temperature and wind distribution of the zonal mean flow in the extratropical troposphere on the gradient of pontential vorticity along isentropes is examined. The extratropics here refer to the region outside the Hadley circulation. Of particular interest is whether the distribution of temperature and wind corresponding to a constant potential vorticity (PV) along isentropes resembles the observed, and the implications of PV homogenization along isentropes for the role of the tropics. With the assumption that PV is homogenized along isentropes, it is found that the temperature distribution in the extratropical troposphere may be determined by a linear, first-order partial differential equation. When the observed surface temperature distribution and tropical lapse rate are used as the boundary conditions, the solution of the equation is close to the observed temperature distribution except in the upper troposphere adjacent to the Hadley circulation, where the troposphere with no PV gradient is considerably colder. Consequently, the jet is also stronger. It is also found that the meridional distribution of the balanced zonal wind is very sensitive to the meridional distribution of the tropopause temperature. The result may suggest that the requirement of the global momentum balance has no practical role in determining the extratropical temperature distribution. The authors further investigated the sensitivity of the extratropical troposphere with constant PV along isentropes to changes in conditions at the tropical boundary (the edge of the Hadley circulation). It is found that the temperature and wind distributions in the extratropical troposphere are sensitive to the vertical distribution of PV at the tropical boundary. With a surface distribution of temperature that decreases linearly with latitude, the jet maximum occurs at the tropical boundary and moves with it. The overall pattern of wind distribution is not sensitive to the change of

  5. Significant influences of global mean temperature and ENSO on extreme rainfall over Southeast Asia

    NASA Astrophysics Data System (ADS)

    Villafuerte, Marcelino, II; Matsumoto, Jun

    2014-05-01

    Along with the increasing concerns on the consequences of global warming, and the accumulating records of disaster related to heavy rainfall events in Southeast Asia, this study investigates whether a direct link can be detected between the rising global mean temperature, as well as the El Niño-Southern Oscillation (ENSO), and extreme rainfall over the region. The maximum likelihood modeling that allows incorporating covariates on the location parameter of the generalized extreme value (GEV) distribution is employed. The GEV model is fitted to annual and seasonal rainfall extremes, which were taken from a high-resolution gauge-based gridded daily precipitation data covering a span of 57 years (1951-2007). Nonstationarities in extreme rainfall are detected over the central parts of Indochina Peninsula, eastern coasts of central Vietnam, northwest of the Sumatra Island, inland portions of Borneo Island, and on the northeastern and southwestern coasts of the Philippines. These nonstationarities in extreme rainfall are directly linked to near-surface global mean temperature and ENSO. In particular, the study reveals that a kelvin increase in global mean temperature anomaly can lead to an increase of 30% to even greater than 45% in annual maximum 1-day rainfall, which were observed pronouncedly over central Vietnam, southern coast of Myanmar, northwestern sections of Thailand, northwestern tip of Sumatra, central portions of Malaysia, and the Visayas island in central Philippines. Furthermore, a pronounced ENSO influence manifested on the seasonal maximum 1-day rainfall; a northward progression of 10%-15% drier condition over Southeast Asia as the El Niño develops from summer to winter is revealed. It is important therefore, to consider the results obtained here for water resources management as well as for adaptation planning to minimize the potential adverse impact of global warming, particularly on extreme rainfall and its associated flood risk over the region

  6. Recent trend analysis of mean air temperature in Greece based on homogenized data

    NASA Astrophysics Data System (ADS)

    Mamara, A.; Argiriou, A. Α.; Anadranistakis, M.

    2016-11-01

    Numerous studies analyze the temperature variations in the Mediterranean area due to the anticipated impact of climate change in this part of the world. A number of studies examined the temperature climate in Greece, but few are based on a large number of synoptic stations covering all regions and climatic zones and even fewer are based on homogenized data set series, despite the fact that climatological studies must use high-quality homogeneous data series. The present work reviews previous studies dealing with climatic changes in Greece and addresses changes of mean air temperature, based on a large set of homogenized data from 52 synoptic stations. A statistically significant negative trend during 1960-1976 and a positive one during 1977-2004 were revealed. During 1960-1976, the lowest negative annual temperature trend is observed in Crete. During 1977-2004, the northern region of Greece was characterized by prominent annual warming, whereas the north and central Aegean Sea and the semi-mountainous area were characterized by the lowest warming. All stations are characterized by high seasonal trends in summer; the most extreme trends are observed in the northern and eastern regions and in the Attica area. Positive temperature trends occur from May to October, while negative trends dominate from November to February. The most pronounced warming is recorded in June and July, and the most strongly decreasing trend occurs in November. Annual temperature trends in northern Greece follow the hemispheric pattern, and the overall summer warming in Greece is greater than the hemisphere's.

  7. Beyond mean-field properties of binary dipolar Bose mixtures at low temperatures

    NASA Astrophysics Data System (ADS)

    Pastukhov, Volodymyr

    2017-02-01

    We rigorously analyze the low-temperature properties of homogeneous three-dimensional two-component Bose mixture with dipole-dipole interaction. For such a system the effective hydrodynamic action that governs the behavior of low-energy excitations is derived. The infrared structure of the exact single-particle Green's functions is obtained in terms of macroscopic parameters, namely the inverse compressibility and the superfluid density matrices. Within the one-loop approximation we calculate some of the most relevant observable quantities and give the beyond mean-field stability condition for the binary dipolar Bose gas in the dilute limit. A brief variational derivation of the coupled equations that describe macroscopic hydrodynamics of the system in the external nonuniform potential at zero temperature is presented.

  8. Spatiotemporal Divergence of the Warming Hiatus over Land Based on Different Definitions of Mean Temperature.

    PubMed

    Zhou, Chunlüe; Wang, Kaicun

    2016-08-17

    Existing studies of the recent warming hiatus over land are primarily based on the average of daily minimum and maximum temperatures (T2). This study compared regional warming rates of mean temperature based on T2 and T24 calculated from hourly observations available from 1998 to 2013. Both T2 and T24 show that the warming hiatus over land is apparent in the mid-latitudes of North America and Eurasia, especially in cold seasons, which is closely associated with the negative North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) and cold air propagation by the Arctic-original northerly wind anomaly into mid-latitudes. However, the warming rates of T2 and T24 are significantly different at regional and seasonal scales because T2 only samples air temperature twice daily and cannot accurately reflect land-atmosphere and incoming radiation variations in the temperature diurnal cycle. The trend has a standard deviation of 0.43 °C/decade for T2 and 0.41 °C/decade for T24, and 0.38 °C/decade for their trend difference in 5° × 5° grids. The use of T2 amplifies the regional contrasts of the warming rate, i.e., the trend underestimation in the US and overestimation at high latitudes by T2.

  9. Spatiotemporal Divergence of the Warming Hiatus over Land Based on Different Definitions of Mean Temperature

    PubMed Central

    Zhou, Chunlüe; Wang, Kaicun

    2016-01-01

    Existing studies of the recent warming hiatus over land are primarily based on the average of daily minimum and maximum temperatures (T2). This study compared regional warming rates of mean temperature based on T2 and T24 calculated from hourly observations available from 1998 to 2013. Both T2 and T24 show that the warming hiatus over land is apparent in the mid-latitudes of North America and Eurasia, especially in cold seasons, which is closely associated with the negative North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) and cold air propagation by the Arctic-original northerly wind anomaly into mid-latitudes. However, the warming rates of T2 and T24 are significantly different at regional and seasonal scales because T2 only samples air temperature twice daily and cannot accurately reflect land-atmosphere and incoming radiation variations in the temperature diurnal cycle. The trend has a standard deviation of 0.43 °C/decade for T2 and 0.41 °C/decade for T24, and 0.38 °C/decade for their trend difference in 5° × 5° grids. The use of T2 amplifies the regional contrasts of the warming rate, i.e., the trend underestimation in the US and overestimation at high latitudes by T2. PMID:27531421

  10. Spatiotemporal Divergence of the Warming Hiatus over Land Based on Different Definitions of Mean Temperature

    NASA Astrophysics Data System (ADS)

    Zhou, Chunlüe; Wang, Kaicun

    2016-08-01

    Existing studies of the recent warming hiatus over land are primarily based on the average of daily minimum and maximum temperatures (T2). This study compared regional warming rates of mean temperature based on T2 and T24 calculated from hourly observations available from 1998 to 2013. Both T2 and T24 show that the warming hiatus over land is apparent in the mid-latitudes of North America and Eurasia, especially in cold seasons, which is closely associated with the negative North Atlantic Oscillation (NAO) and Arctic Oscillation (AO) and cold air propagation by the Arctic-original northerly wind anomaly into mid-latitudes. However, the warming rates of T2 and T24 are significantly different at regional and seasonal scales because T2 only samples air temperature twice daily and cannot accurately reflect land-atmosphere and incoming radiation variations in the temperature diurnal cycle. The trend has a standard deviation of 0.43 °C/decade for T2 and 0.41 °C/decade for T24, and 0.38 °C/decade for their trend difference in 5° × 5° grids. The use of T2 amplifies the regional contrasts of the warming rate, i.e., the trend underestimation in the US and overestimation at high latitudes by T2.

  11. Behavior of zonal mean aerosol extinction ratio and its relationship with zonal mean temperature during the winter 1978-1979 stratospheric warming

    NASA Technical Reports Server (NTRS)

    Wang, P.-H.; Mccormick, M. P.

    1985-01-01

    The behavior of the zonal mean aerosol extinction ratio in the lower stratosphere near 75 deg N and its relationship with the zonal mean temperature during the January-February 1979 stratospheric sudden warming have been investigated based on the satellite sensor SAM II (Stratospheric Aerosol Measurement) and auxiliary meteorological measurements. The results indicate that distinct changes in the zonal mean aerosol extinction ratio occurred during this stratospheric sudden warming. It is also found that horizontal eddy transport due to planetary waves may have played a significant role in determining the distribution of the zonal mean aerosol extinction ratio.

  12. Climate reconstructions of the NH mean temperature: Can underestimation of trends and variability be avoided?

    NASA Astrophysics Data System (ADS)

    Christiansen, Bo

    2010-05-01

    Knowledge about the climate in the period before instrumental records are available is based on climate proxies obtained from tree-rings, sediments, ice-cores etc. Reconstructing the climate from such proxies is therefore necessary for studies of climate variability and for placing recent climate change into a longer term perspective. More than a decade ago pioneering attempts at using a multi-proxy dataset to reconstruct the Northern Hemisphere (NH) mean temperature resulted in the much published "hockey-stick"; a NH mean temperature that did not vary much before the rapid increase in the last century. Subsequent reconstructions show some differences but the overall "hockey-stick" structure seems to be a persistent feature However, there has been an increasing awareness of the fact that the applied reconstruction methods underestimate the low-frequency variability and trends. The recognition of the inadequacies of the reconstruction methods has to a large degree originated from pseudo-proxy studies, i.e., from long climate model experiments where artificial proxies have been generated and reconstructions based on these have been compared to the known model climate. It has also been found that reconstructions contain a large element of stochasticity which is revealed as broad distributions of skills. This means that it is very difficult to draw conclusions from a single or a few realizations. Climate reconstruction methods are based on variants of linear regression models relating temperatures and proxies. In this contribution we review some of the theory of linear regression and error-in-variables models to identify the sources of the underestimation of variability. Based on the gained insight we formulate a reconstruction method supposed to minimize this underestimation. The method is tested by applying it to an ensemble of surrogate temperature fields based on two climate simulations covering the last 500 and 1000 years. Compared to the RegEM TTLS method and a

  13. Absolutely classical spin states

    NASA Astrophysics Data System (ADS)

    Bohnet-Waldraff, F.; Giraud, O.; Braun, D.

    2017-01-01

    We introduce the concept of "absolutely classical" spin states, in analogy to absolutely separable states of bipartite quantum systems. Absolutely classical states are states that remain classical (i.e., a convex sum of projectors on coherent states of a spin j ) under any unitary transformation applied to them. We investigate the maximal size of the ball of absolutely classical states centered on the maximally mixed state and derive a lower bound for its radius as a function of the total spin quantum number. We also obtain a numerical estimate of this maximal radius and compare it to the case of absolutely separable states.

  14. Analytical solution for the effect of increasing CO2 on global mean temperature

    NASA Astrophysics Data System (ADS)

    Wigley, T. M. L.; Schlesinger, M. E.

    1985-06-01

    The effect on global mean temperature of forcing by a step function change in CO2 concentration and by a steady CO2 increase is analyzed. The former case involves a response time which is strongly dependent on both the effective diffusivity of the ocean below the upper mixed layer, or kappa, and the climate sensitivity, or dT(2x). In the latter case the damped response means that, at any given time, the climate system may be quite far removed from its equilibrium with the prevailing CO2 level. In earlier work this equilibrium was expressed as lag time, but this is shown to be misleading because of the sensitivity of the lag to the history of past CO2 variations. Since both the lag and the degree of disequilibrium are strongly dependent on kappa and dT(2x), and because of uncertainties in the preindustrial CO2 level, the observed global warming over the past 100 years can be shown to be compatible with a wide range of CO2-doubling temperature changes.

  15. Monthly mean global climatology of temperature, wind, geopotential height, and pressure for 0 - 120 km

    NASA Technical Reports Server (NTRS)

    Fleming, Eric L.; Chandra, Sushil; Schoeberl, Mark R.; Barnett, John J.

    1988-01-01

    A monthly mean climatology is presented of temperature, wind, and geopotential height with nearly pole-to-pole coverage (80 S to 80 N) for 0 to 210 km, which can be used as a function of altitude and pressure. The purpose is to provide a reference for various atmospheric research and analysis activities. Data sources and methods of computation are described; in general, hydrostatic and thermal wind balance are maintained at all levels and latitudes. As observed in a series of cross-sectional plots, this climatology accurately reproduces most of the characteristic features of the atmosphere such as equatorial wind and the general structure of the tropopause, stratopause, and mesopause. A series of zonal wind profiles is also represented comparing this climatological wind with monthly mean climatological direct wind measurements in the upper mesosphere and lower thermosphere. The temperature and zonal wind climatology at stratospheric levels is compared with corresponding data from the National Meteorological Center, and general agreement is observed between the two data sets. Tables of the climatological values as a function of latitude and height for each month are contained in Appendix B, and are also available in floppy disk.

  16. Cenozoic mean greenhouse gases and temperature changes with reference to the Anthropocene.

    PubMed

    Glikson, Andrew

    2016-12-01

    Cenozoic greenhouse gases (GHG) variations and warming periods underscore the extreme rates of current climate change, with major implications for the adaptability and survivability of terrestrial and marine habitats. Current rise rate of greenhouse gases, reaching 3.3 ppm CO2 per year during March 2015-2016, is the fastest recorded since the Paleocene-Eocene Thermal Event (PETM) when carbon release to the atmosphere was about an order of magnitude less than at present. The ice core evidence of concentration of (GHG) and temperatures in the atmosphere/ocean/cryosphere system over the last 740 kyr suggests that the rate of rise in GHG over the last ~260 years, CO2 rates rising from 0.94 ppm yr(-1) in 1959 (315.97 ppm) to 1.62 ppm yr(-1) in 2000 (369.52 ppm) to 3.05 ppm yr(-1) in 2015 (400.83 ppm), constitutes a unique spike in the history of the atmosphere. The reliance of pre-740 kyr paleoclimate estimates on multiple proxies, including benthic and plankton fossils, fossil plants, residual organic matter, major and trace elements in fossils, sediments and soils, place limits on the resolution of pre-upper Pleistocene paleoclimate estimates, rendering it likely recorded mean Cenozoic paleoclimate trends may conceal abrupt short-term climate fluctuations. However, as exemplified by the Paleocene-Eocene thermal maximum (PETM) and earlier GHG and temperature spikes associated with major volcanic and asteroid impact events, the long-term residence time of CO2 in the atmosphere extends the signatures of abrupt warming events to within detection limits of multiple paleoproxies. The mean post-1750 temperature rise rate (approximately ~0.0034 °C per yr, or ~0.008 °C per yr where temperature is not masked by sulfur aerosols) exceeds those of the PETM (approximately ~0.0008-0.0015 °C per yr) by an order of magnitude and mean glacial termination warming rates (last glacial termination [LGT] ~ 0.00039; Eemian ~0.0004 °C per yr) by near to an order of magnitude

  17. Database applicaton for absolute spectrophotometry

    NASA Astrophysics Data System (ADS)

    Bochkov, Valery V.; Shumko, Sergiy

    2002-12-01

    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.

  18. Estimation of offshore humidity fluxes from sonic and mean temperature profile data

    NASA Astrophysics Data System (ADS)

    Foreman, R. J.; Emeis, S. M.

    2009-09-01

    A new simple method is employed to estimate the virtual potential temperature flux in marine conditions in the absence of any reliable hygrometry measurements. The estimate is made from a combination of sonic and cup anemometer measurements. Since the measurement of temperature by a sonic is humidity dependent, it overestimates the heat flux by a magnitude of 0.51?w?q?, where ? is the potential temperature in Kelvin and w?q? is the humidity flux. However, the quantity of interest for many applications is the virtual potential temperature flux w???v, which itself overestimates the heat flux by a magnitude of 0.61?w?q?. The virtual potential temperature flux is thus estimated by w-???v = w???s + 0.1?w?q?, (1) where w???s is the measured sonic anemometer heat flux. To properly estimate w?q?, fast response hygrometers are required, but in their absence, mean measurements can be used. While we have access to standard hygrometers, there are reasons to question the validity of results from these. Therefore, we propose that w???v be estimated by equating the stability parameter z?L, where z is the height and L the Obukhov length (which contains w???v and hence eq. (1)) with the bulk Richardson number and solving for w?q?, giving ( 3 --?? ) w-?q? = - 10 u*Rb-+ w-?-s . kzg ?v (2) Upon substituting eq. (2) into (1), and comparing terms on the right hand side of eq. (1), it is found that the contribution of the moisture term is an order of magnitude greater than that of the sonic measurement. This result is broadly consistent with previously published measurements, for example by Sempreviva and Gryning (1996) and Edson et al. (2004), of humidity fluxes using fast-response hygrometers in marine environments. We conclude that moisture effects are the chief determinant of instability in the marine surface layer. Consequently, the not unusual neglect of humidity effects in analytical and modelling efforts will result in a poor estimation of such quantities as the Obukhov length

  19. Conductive and evaporative precooling lowers mean skin temperature and improves time trial performance in the heat.

    PubMed

    Faulkner, S H; Hupperets, M; Hodder, S G; Havenith, G

    2015-06-01

    Self-paced endurance performance is compromised by moderate-to-high ambient temperatures that are evident in many competitive settings. It has become common place to implement precooling prior to competition in an attempt to alleviate perceived thermal load and performance decline. The present study aimed to investigate precooling incorporating different cooling avenues via either evaporative cooling alone or in combination with conductive cooling on cycling time trial performance. Ten trained male cyclists completed a time trial on three occasions in hot (35 °C) ambient conditions with the cooling garment prepared by (a) immersion in water (COOL, evaporative); (b) immersion in water and frozen (COLD, evaporative and conductive); or (c) no precooling (CONT). COLD improved time trial performance by 5.8% and 2.6% vs CONT and COOL, respectively (both P < 0.05). Power output was 4.5% higher for COLD vs CONT (P < 0.05). Mean skin temperature was lower at the onset of the time trial following COLD compared with COOL and CONT (both P < 0.05) and lasted for the first 20% of the time trial. Thermal sensation was perceived cooler following COOL and COLD. The combination of evaporative and conductive cooling (COLD) had the greatest benefit to performance, which is suggested to be driven by reduced skin temperature following cooling.

  20. Numerical study of heterogeneous mean temperature and shock wave in a resonator

    NASA Astrophysics Data System (ADS)

    Yano, Takeru

    2015-10-01

    When a frequency of gas oscillation in an acoustic resonator is sufficiently close to one of resonant frequencies of the resonator, the amplitude of gas oscillation becomes large and hence the nonlinear effect manifests itself. Then, if the dissipation effects due to viscosity and thermal conductivity of the gas are sufficiently small, the gas oscillation may evolve into the acoustic shock wave, in the so-called consonant resonators. At the shock front, the kinetic energy of gas oscillation is converted into heat by the dissipation process inside the shock layer, and therefore the temperature of the gas in the resonator rises. Since the acoustic shock wave travels in the resonator repeatedly over and over again, the temperature rise becomes noticeable in due course of time even if the shock wave is weak. We numerically study the gas oscillation with shock wave in a resonator of square cross section by solving the initial and boundary value problem of the system of three-dimensional Navier-Stokes equations with a finite difference method. In this case, the heat conduction across the boundary layer on the wall of resonator causes a spatially heterogeneous distribution of mean (time-averaged) gas temperature.

  1. Mid-Piacensian mean annual sea surface temperature: an analysis for data-model comparisons

    USGS Publications Warehouse

    Dowsett, Harry J.; Robinson, Marci M.; Foley, Kevin M.; Stoll, Danielle K.

    2010-01-01

    Numerical models of the global climate system are the primary tools used to understand and project climate disruptions in the form of future global warming. The Pliocene has been identified as the closest, albeit imperfect, analog to climate conditions expected for the end of this century, making an independent data set of Pliocene conditions necessary for ground truthing model results. Because most climate model output is produced in the form ofmean annual conditions, we present a derivative of the USGS PRISM3 Global Climate Reconstruction which integrates multiple proxies of sea surface temperature (SST) into single surface temperature anomalies. We analyze temperature estimates from faunal and floral assemblage data,Mg/Ca values and alkenone unsaturation indices to arrive at a single mean annual SST anomaly (Pliocene minus modern) best describing each PRISM site, understanding that multiple proxies should not necessarily show concordance. The power of themultiple proxy approach lies within its diversity, as no two proxies measure the same environmental variable. This data set can be used to verify climate model output, to serve as a starting point for model inter-comparisons, and for quantifying uncertainty in Pliocene model prediction in perturbed physics ensembles.

  2. Numerical study of heterogeneous mean temperature and shock wave in a resonator

    SciTech Connect

    Yano, Takeru

    2015-10-28

    When a frequency of gas oscillation in an acoustic resonator is sufficiently close to one of resonant frequencies of the resonator, the amplitude of gas oscillation becomes large and hence the nonlinear effect manifests itself. Then, if the dissipation effects due to viscosity and thermal conductivity of the gas are sufficiently small, the gas oscillation may evolve into the acoustic shock wave, in the so-called consonant resonators. At the shock front, the kinetic energy of gas oscillation is converted into heat by the dissipation process inside the shock layer, and therefore the temperature of the gas in the resonator rises. Since the acoustic shock wave travels in the resonator repeatedly over and over again, the temperature rise becomes noticeable in due course of time even if the shock wave is weak. We numerically study the gas oscillation with shock wave in a resonator of square cross section by solving the initial and boundary value problem of the system of three-dimensional Navier-Stokes equations with a finite difference method. In this case, the heat conduction across the boundary layer on the wall of resonator causes a spatially heterogeneous distribution of mean (time-averaged) gas temperature.

  3. Leaf litter decomposition rates increase with rising mean annual temperature in Hawaiian tropical montane wet forests.

    PubMed

    Bothwell, Lori D; Selmants, Paul C; Giardina, Christian P; Litton, Creighton M

    2014-01-01

    Decomposing litter in forest ecosystems supplies nutrients to plants, carbon to heterotrophic soil microorganisms and is a large source of CO2 to the atmosphere. Despite its essential role in carbon and nutrient cycling, the temperature sensitivity of leaf litter decay in tropical forest ecosystems remains poorly resolved, especially in tropical montane wet forests where the warming trend may be amplified compared to tropical wet forests at lower elevations. We quantified leaf litter decomposition rates along a highly constrained 5.2 °C mean annual temperature (MAT) gradient in tropical montane wet forests on the Island of Hawaii. Dominant vegetation, substrate type and age, soil moisture, and disturbance history are all nearly constant across this gradient, allowing us to isolate the effect of rising MAT on leaf litter decomposition and nutrient release. Leaf litter decomposition rates were a positive linear function of MAT, causing the residence time of leaf litter on the forest floor to decline by ∼31 days for each 1 °C increase in MAT. Our estimate of the Q 10 temperature coefficient for leaf litter decomposition was 2.17, within the commonly reported range for heterotrophic organic matter decomposition (1.5-2.5) across a broad range of ecosystems. The percentage of leaf litter nitrogen (N) remaining after six months declined linearly with increasing MAT from ∼88% of initial N at the coolest site to ∼74% at the warmest site. The lack of net N immobilization during all three litter collection periods at all MAT plots indicates that N was not limiting to leaf litter decomposition, regardless of temperature. These results suggest that leaf litter decay in tropical montane wet forests may be more sensitive to rising MAT than in tropical lowland wet forests, and that increased rates of N release from decomposing litter could delay or prevent progressive N limitation to net primary productivity with climate warming.

  4. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  5. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  6. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  7. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  8. 46 CFR 154.1836 - Vapor venting as a means of cargo tank pressure and temperature control.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... temperature control. 154.1836 Section 154.1836 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY... LIQUEFIED GASES Operations § 154.1836 Vapor venting as a means of cargo tank pressure and temperature... cargo pressure and temperature control system under §§ 154.701 through 154.709 is operating and...

  9. Projected Changes in Seasonal Mean Temperature and Rainfall (2011-2040) in Cagayan Valley, Philippines

    NASA Astrophysics Data System (ADS)

    Basconcillo, J. Q.; Lucero, A. J. R.; Solis, A. S.; Kanamaru, H.; Sandoval, R. S.; Bautista, E. U.

    2014-12-01

    Among Filipinos, a meal is most often considered incomplete without rice. There is a high regard for rice in the entire archipelago that in 2012, the country's rice production was accounted to more than 18 million tons with an equivalent harvested area of 4.7 million hectares. This means that from the 5.4 million hectares of arable land in the Philippines, 11 percent are found and being utilized for rice production in Cagayan Valley (CV). In the same year, more than 13 percent of the country's total annual rice production was produced in CV. Rice production also provides employment to 844,000 persons (out of 1.4 million persons) which suggest that occupation and livelihood in Cagayan Valley are strongly anchored in rice production. These figures outline the imaginable vulnerability of rice production in CV amidst varying issues such as land conversion, urbanization, increase in population, retention of farming households, and climate change. While all these issues are of equal importance, this paper is directed towards the understanding the projected changes in seasonal rainfall and mean temperature (2011-2040). It is envisioned by this study that a successful climate change adaptation starts with the provision of climate projections hence this paper's objective to investigate on the changes in climate patterns and extreme events. Projected changes are zonally limited to the Provinces of Cagayan, Isabela, Nueva Vizcaya, and Quirino based on the statistical downscaling of three global climate models (BCM2, CNCM3, and MPEH5) and two emission scenarios (A1B and A2). With the idea that rainfall and temperature varies with topography, the AURELHY technique was utilized in interpolating climate projections. Results obtained from the statistical downscaling showed that there will be significant climate changes from 2011-2040 in terms of rainfall and mean temperature. There are also indications of increasing frequency of extreme 24-hour rainfall and number of dry days

  10. Absolute nuclear material assay

    DOEpatents

    Prasad, Manoj K [Pleasanton, CA; Snyderman, Neal J [Berkeley, CA; Rowland, Mark S [Alamo, CA

    2012-05-15

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

  11. Absolute nuclear material assay

    DOEpatents

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

    2010-07-13

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

  12. NAO implicated as a predictor of Northern Hemisphere mean temperature multidecadal variability

    NASA Astrophysics Data System (ADS)

    Li, Jianping; Sun, Cheng; Jin, Fei-Fei

    2013-10-01

    twentieth century Northern Hemisphere mean surface temperature (NHT) is characterized by a multidecadal warming-cooling-warming pattern followed by a flat trend since about 2000 (recent warming hiatus). Here we demonstrate that the North Atlantic Oscillation (NAO) is implicated as a useful predictor of NHT multidecadal variability. Observational analysis shows that the NAO leads both the detrended NHT and oceanic Atlantic Multidecadal Oscillation (AMO) by 15-20 years. Theoretical analysis illuminates that the NAO precedes NHT multidecadal variability through its delayed effect on the AMO due to the large thermal inertia associated with slow oceanic processes. An NAO-based linear model is therefore established to predict the NHT, which gives an excellent hindcast for NHT in 1971-2011 with the recent flat trend well predicted. NHT in 2012-2027 is predicted to fall slightly over the next decades, due to the recent NAO decadal weakening that temporarily offsets the anthropogenically induced warming.

  13. Influence of ground surface characteristics on the mean radiant temperature in urban areas

    NASA Astrophysics Data System (ADS)

    Lindberg, Fredrik; Onomura, Shiho; Grimmond, C. S. B.

    2016-09-01

    The effect of variations in land cover on mean radiant temperature ( T mrt ) is explored through a simple scheme developed within the radiation model SOLWEIG. Outgoing longwave radiation is parameterised using surface temperature observations on a grass and an asphalt surface, whereas outgoing shortwave radiation is modelled through variations in albedo for the different surfaces. The influence of ground surface materials on T mrt is small compared to the effects of shadowing. Nevertheless, altering ground surface materials could contribute to a reduction in T mrt to reduce the radiant load during heat-wave episodes in locations where shadowing is not an option. Evaluation of the new scheme suggests that despite its simplicity it can simulate the outgoing fluxes well, especially during sunny conditions. However, it underestimates at night and in shadowed locations. One grass surface used to develop the parameterisation, with very different characteristics compared to an evaluation grass site, caused T mrt to be underestimated. The implications of using high temporal resolution (e.g. 15 minutes) meteorological forcing data under partly cloudy conditions are demonstrated even for fairly proximal sites.

  14. A study of radiometric surface temperatures: Their fluctuations, distribution and meaning. [Voves, France

    NASA Technical Reports Server (NTRS)

    Perrier, A.; Itier, B.; Boissard, P. (Principal Investigator); Goillot, C.; Belluomo, P.; Valery, P.

    1980-01-01

    A consecutive night and day flight and measurements on the ground, were made in the region of Voves, south of Chartres. The statistical analysis of the thermal scanner data permitted the establishment of criteria for the homogeneity of surfaces. These criteria were used in defining the surface temperature values which are most representative for use in an energy balance approach to evapotranspiration (day) and heat balance (night). For a number of maize fields that airborne thermal scanner data permitted a detailed energy analysis of different fields of a same crop to be carried out. Such a detailed analysis was not necessary for a calculation of crop evapotranspiration which could be evaluated from the mean temperature of the crop surface. A differential analysis day night is of interest for enhancing the contrast between types of surfaces, as well as for a better definition of the daily energy balance. It should be stressed that, for a homogeneous region, a study such as the present one, could be carried out on a relatively small part of the total surface, as the results for a surface of 2.5 x 2 sq km were not significantly different from those obtained from a surface three times larger.

  15. Gravity Wave Variance in LIMS Temperatures. Part II: Comparison with the Zonal-Mean Momentum Balance.

    NASA Astrophysics Data System (ADS)

    Fetzer, Eric J.; Gille, John C.

    1996-02-01

    Zonal-mean gravity wave variance in the Limb Infrared Monitor of the Stratosphere (LIMS) temperature data is seen to correlate strongly with the residual term in the LIMS zonal-mean momentum budget throughout much of the observed mesosphere. This momentum residual is attributed to gravity wave momentum transport at scales that cannot be directly sampled by the LIMS instrument Correlation is highest in the vicinity of the fall and winter mesospheric jets, where both gravity wave variance and momentum residual reach their largest values. Correlation is also high in the Southern Hemisphere subtropical mesophere, where gravity wave variance and the momentum residual have broad temporal maxima during the easterly acceleration of the stratopause semi-annual oscillation (SAO). This subtropical correlation has important implications for the SAO eastward acceleration, which several studies suggest is forced by gravity wave momentum flux divergence. Correlation between gravity wave variance and inferred gravity wave momentum flux divergence is unexpected because variance is dominated by large scales and long periods (inertio-gravity waves), while both theoretical arguments and ground-based observations indicate that momentum transport is dominated by periods under 1 h. The results of this study suggest a broadband gravity wave field experiencing forcing and loss processes, which are largely independent of frequency.

  16. Iron overload detection in rats by means of a susceptometer operating at room temperature

    NASA Astrophysics Data System (ADS)

    Marinelli, M.; Gianesin, B.; Avignolo, C.; Minganti, V.; Parodi, S.

    2008-12-01

    Biosusceptometry is a non-invasive procedure for determination of iron overload in a human body; it is essentially an assessment of the diamagnetic (water) and paramagnetic (iron) properties of tissues. We measured in vivo iron overload in the liver region of 12 rats by a room temperature susceptometer. The rats had been injected with sub-toxic doses of iron dextran. A quantitative relationship has been observed between the measurements and the number of treatments. The assessment of iron overload requires evaluating the magnetic signal corresponding to the same rat ideally without the overload. This background value was extrapolated on the basis of the signal measured in control rats versus body weight (R2 = 0.73). The mean iron overload values for the treated rats, obtained after each iron injection, were significantly different from the means of the corresponding control rats (p < 0.01). The in vivo measurements have been complemented by chemical analysis on excised livers and other organs (R2 = 0.89). The magnetic moment of iron atoms in liver tissues was measured to be 3.6 Bohr magneton. Evaluation of the background signal is the limit to the measure; the error corresponds to about 30 mg (1 SD) of iron while the instrument sensitivity is more than a factor of 10 better.

  17. Thermodynamic properties of rhodium at high temperature and pressure by using mean field potential approach

    NASA Astrophysics Data System (ADS)

    Kumar, Priyank; Bhatt, Nisarg K.; Vyas, Pulastya R.; Gohel, Vinod B.

    2016-10-01

    The thermophysical properties of rhodium are studied up to melting temperature by incorporating anharmonic effects due to lattice ions and thermally excited electrons. In order to account anharmonic effects due to lattice vibrations, we have employed mean field potential (MFP) approach and for thermally excited electrons Mermin functional. The local form of the pseudopotential with only one effective adjustable parameter rc is used to construct MFP and hence vibrational free energy due to ions - Fion. We have studied equation of state at 300 K and further, to access the applicability of present conjunction scheme, we have also estimated shock-Hugoniot and temperature along principle Hugoniot. We have carried out the study of temperature variation of several thermophysical properties like thermal expansion (βP), enthalpy (EH), specific heats at constant pressure and volume (CP and CV), specific heats due to lattice ions and thermally excited electrons ( and , isothermal and adiabatic bulk moduli (BT and Bs) and thermodynamic Gruneisen parameter (γth) in order to examine the inclusion of anharmonic effects in the present study. The computed results are compared with available experimental results measured by using different methods and previously obtained theoretical results using different theoretical philosophy. Our computed results are in good agreement with experimental findings and for some physical quantities better or comparable with other theoretical results. We conclude that local form of the pseudopotential used accounts s-p-d hybridization properly and found to be transferable at extreme environment without changing the values of the parameter. Thus, even the behavior of transition metals having complexity in electronic structure can be well understood with local pseudopotential without any modification in the potential at extreme environment. Looking to the success of present scheme (MFP + pseudopotential) we would like to extend it further for the

  18. A variable temperature EPR study of Mn(2+)-doped NH(4)Cl(0.9)I(0.1) single crystal at 170 GHz: zero-field splitting parameter and its absolute sign.

    PubMed

    Misra, Sushil K; Andronenko, Serguei I; Chand, Prem; Earle, Keith A; Paschenko, Sergei V; Freed, Jack H

    2005-06-01

    EPR measurements have been carried out on a single crystal of Mn(2+)-doped NH(4)Cl(0.9)I(0.1) at 170-GHz in the temperature range of 312-4.2K. The spectra have been analyzed (i) to estimate the spin-Hamiltonian parameters; (ii) to study the temperature variation of the zero-field splitting (ZFS) parameter; (iii) to confirm the negative absolute sign of the ZFS parameter unequivocally from the temperature-dependent relative intensities of hyperfine sextets at temperatures below 10K; and (iv) to detect the occurrence of a structural phase transition at 4.35K from the change in the structure of the EPR lines with temperature below 10K.

  19. Are recent global mean temperature trends anomalous relative to the CMIP5 ensemble?

    NASA Astrophysics Data System (ADS)

    Lin, M.; Huybers, P. J.

    2015-12-01

    Recent studies have described a slow-down in the rise in global mean temperature over the past 15 years, noting that these trends are anomalous with respect to the trends predicted by the CMIP5 ensemble. This result has been shown to be sensitive to the choice of starting year when assessing the hiatus with a simple linear regression. It is also sensitive to assumptions about the independence of CMIP5 ensemble members when estimating distributions of the CMIP5 ensemble. We address these interdependences of ensemble members by exploring two end-member scenarios of the CMIP5 ensemble: one in which each ensemble member is assumed independent and a second in which modeling centers are assumed independent. A more stable metric of trend, the δ-slope, is employed to measure the recent divergence of a temperature time-series from the average CMIP5 projection. When treating each CMIP5 ensemble member as independent, we find that observed recent trends are anomalous for all hiatus periods starting after 1997 at the 95% confidence level. However, for the scenario assuming modeling centers to be independent, we find that observed recent trends are consistent with the CMIP5 ensemble at the 95% confidence level. This result holds across all plausible hiatus starting years tested (1990-2005). Using the Ansari-Bradley rank-sum test, seven modeling centers comprising 58 ensemble members are each shown to have lower spread in δ-slope values than the distribution of δ slope values of CMIP5 ensemble members outside each modeling center at the 95% confidence level. This supports the end-member scenario that treats each modeling center as independent. In addition, examination of spatial patterns of δ-slope in each CMIP5 ensemble member reveals that the simulation that is closest to observations in global mean temperature δ-slope value also has one of the highest δ-slope spatial pattern correlations with observations. This pattern reflects a strong negative phase of the Pacific

  20. Temperature and bath size in exact diagonalization dynamical mean field theory.

    PubMed

    Liebsch, Ansgar; Ishida, Hiroshi

    2012-02-08

    Dynamical mean field theory (DMFT), combined with finite-temperature exact diagonalization, is one of the methods used to describe electronic properties of strongly correlated materials. Because of the rapid growth of the Hilbert space, the size of the finite bath used to represent the infinite lattice is severely limited. In view of the increasing interest in the effect of multi-orbital and multi-site Coulomb correlations in transition metal oxides, high-T(c) cuprates, iron-based pnictides, organic crystals, etc, it is appropriate to explore the range of temperatures and bath sizes in which exact diagonalization provides accurate results for various system properties. On the one hand, the bath must be large enough to achieve a sufficiently dense level spacing, so that useful spectral information can be derived, especially close to the Fermi level. On the other hand, for an adequate projection of the lattice Green's function onto a finite bath, the choice of the temperature is crucial. The role of these two key ingredients in exact diagonalization DMFT is discussed for a wide variety of systems in order to establish the domain of applicability of this approach. Three criteria are used to illustrate the accuracy of the results: (i) the convergence of the self-energy with the bath size, (ii) the quality of the discretization of the bath Green's function, and (iii) comparisons with complementary results obtained via continuous-time quantum Monte Carlo DMFT. The materials comprise a variety of three-orbital and five-orbital systems, as well as single-band Hubbard models for two-dimensional triangular, square and honeycomb lattices, where non-local Coulomb correlations are important. The main conclusion from these examples is that a larger number of correlated orbitals or sites requires a smaller number of bath levels. Down to temperatures of 5-10 meV (for typical bandwidths W ≈ 2 eV) two bath levels per correlated impurity orbital or site are usually adequate.

  1. Electron cyclotron emission spectra in X- and O-mode polarisation at JET: Martin-Puplett interferometer, absolute calibration, revised uncertainties, inboard/outboard temperature profile, and wall properties

    NASA Astrophysics Data System (ADS)

    Schmuck, S.; Fessey, J.; Boom, J. E.; Meneses, L.; Abreu, P.; Belonohy, E.; Lupelli, I.

    2016-09-01

    At the tokamak Joint European Torus (JET), the electron cyclotron emission spectra in O-mode and X-mode polarisations are diagnosed simultaneous in absolute terms for several harmonics with two Martin-Puplett interferometers. From the second harmonic range in X-mode polarisation, the electron temperature profile can be deduced for the outboard side (low magnetic field strength) of JET but only for some parts of the inboard side (high magnetic field strength). This spatial restriction can be bypassed, if a cutoff is not present inside the plasma for O-mode waves in the first harmonic range. Then, from this spectral domain, the profile on the entire inboard side is accessible. The profile determination relies on the new absolute and independent calibration for both interferometers. During the calibration procedure, the antenna pattern was investigated as well, and, potentially, an increase in the diagnostic responsivity of about 5% was found for the domain 100-300 GHz. This increase and other uncertainty sources are taken into account in the thorough revision of the uncertainty for the diagnostic absolute calibration. The uncertainty deduced and the convolution inherent for Fourier spectroscopy diagnostics have implications for the temperature profile inferred. Having probed the electron cyclotron emission spectra in orthogonal polarisation directions for the first harmonic range, a condition is derived for the reflection and polarisation-scrambling coefficients of the first wall on the outboard side of JET.

  2. Absolute Standards for Climate Measurements

    NASA Astrophysics Data System (ADS)

    Leckey, J.

    2016-10-01

    In a world of changing climate, political uncertainty, and ever-changing budgets, the benefit of measurements traceable to SI standards increases by the day. To truly resolve climate change trends on a decadal time scale, on-orbit measurements need to be referenced to something that is both absolute and unchanging. One such mission is the Climate Absolute Radiance and Refractivity Observatory (CLARREO) that will measure a variety of climate variables with an unprecedented accuracy to definitively quantify climate change. In the CLARREO mission, we will utilize phase change cells in which a material is melted to calibrate the temperature of a blackbody that can then be observed by a spectrometer. A material's melting point is an unchanging physical constant that, through a series of transfers, can ultimately calibrate a spectrometer on an absolute scale. CLARREO consists of two primary instruments: an infrared (IR) spectrometer and a reflected solar (RS) spectrometer. The mission will contain orbiting radiometers with sufficient accuracy to calibrate other space-based instrumentation and thus transferring the absolute traceability. The status of various mission options will be presented.

  3. Validation of the mean radiant temperature simulated by the RayMan software in urban environments

    NASA Astrophysics Data System (ADS)

    Lee, Hyunjung; Mayer, Helmut

    2016-11-01

    The RayMan software is worldwide applied in investigations on different issues in human-biometeorology. However, only the simulated mean radiant temperature ( T mrt) has been validated so far in a few case studies. They are based on T mrt values, which were experimentally determined in urban environments by use of a globe thermometer or applying the six-directional method. This study analyses previous T mrt validations in a comparative manner. Their results are extended by a recent validation of T mrt in an urban micro-environment in Freiburg (southwest Germany), which can be regarded as relatively heterogeneous due to different shading intensities by tree crowns. In addition, a validation of the physiologically equivalent temperature (PET) simulated by RayMan is conducted for the first time. The validations are based on experimentally determined T mrt and PET values, which were calculated from measured meteorological variables in the daytime of a clear-sky summer day. In total, the validation results show that RayMan is capable of simulating T mrt satisfactorily under relatively homogeneous site conditions. However, the inaccuracy of simulated T mrt is increasing with lower sun elevation and growing heterogeneity of the simulation site. As T mrt represents the meteorological variable that mostly governs PET in the daytime of clear-sky summer days, the accuracy of simulated T mrt is mainly responsible for the accuracy of simulated PET. The T mrt validations result in some recommendations, which concern an update of physical principles applied in the RayMan software to simulate the short- and long-wave radiant flux densities, especially from vertical building walls and tree crowns.

  4. Ecosystem carbon storage does not vary with mean annual temperature in Hawaiian tropical montane wet forests.

    PubMed

    Selmants, Paul C; Litton, Creighton M; Giardina, Christian P; Asner, Gregory P

    2014-09-01

    Theory and experiment agree that climate warming will increase carbon fluxes between terrestrial ecosystems and the atmosphere. The effect of this increased exchange on terrestrial carbon storage is less predictable, with important implications for potential feedbacks to the climate system. We quantified how increased mean annual temperature (MAT) affects ecosystem carbon storage in above- and belowground live biomass and detritus across a well-constrained 5.2 °C MAT gradient in tropical montane wet forests on the Island of Hawaii. This gradient does not systematically vary in biotic or abiotic factors other than MAT (i.e. dominant vegetation, substrate type and age, soil water balance, and disturbance history), allowing us to isolate the impact of MAT on ecosystem carbon storage. Live biomass carbon did not vary predictably as a function of MAT, while detrital carbon declined by ~14 Mg of carbon ha(-1) for each 1 °C rise in temperature - a trend driven entirely by coarse woody debris and litter. The largest detrital pool, soil organic carbon, was the most stable with MAT and averaged 48% of total ecosystem carbon across the MAT gradient. Total ecosystem carbon did not vary significantly with MAT, and the distribution of ecosystem carbon between live biomass and detritus remained relatively constant across the MAT gradient at ~44% and ~56%, respectively. These findings suggest that in the absence of alterations to precipitation or disturbance regimes, the size and distribution of carbon pools in tropical montane wet forests will be less sensitive to rising MAT than predicted by ecosystem models. This article also provides needed detail on how individual carbon pools and ecosystem-level carbon storage will respond to future warming.

  5. The observed sensitivity of high clouds to mean surface temperature anomalies in the tropics

    NASA Astrophysics Data System (ADS)

    Zelinka, Mark D.; Hartmann, Dennis L.

    2011-12-01

    Cloud feedback represents the source of largest diversity in projections of future warming. Observational constraints on both the sign and magnitude of the feedback are limited, since it is unclear how the natural variability that can be observed is related to secular climate change, and analyses have rarely been focused on testable physical theories for how clouds should respond to climate change. In this study we use observations from a suite of satellite instruments to assess the sensitivity of tropical high clouds to interannual tropical mean surface temperature anomalies. We relate cloud changes to a physical governing mechanism that is sensitive to the vertical structure of warming. Specifically, we demonstrate that the mean and interannual variability in both the altitude and fractional coverage of tropical high clouds as measured by CloudSat, the Moderate Resolution Imaging Spectroradiometer, the Atmospheric Infrared Sounder, and the International Satellite Cloud Climatology Project are well diagnosed by upper tropospheric convergence computed from the mass and energy budget of the clear-sky atmosphere. Observed high clouds rise approximately isothermally in accordance with theory and exhibit an overall reduction in coverage when the tropics warms, similar to their behavior in global warming simulations. Such cloud changes cause absorbed solar radiation to increase more than does outgoing longwave radiation, resulting in a positive but statistically insignificant net high cloud feedback in response to El Niño-Southern Oscillation. The results suggest that the convergence metric based on simple mass and energy budget constraints may be a powerful tool for understanding observed and modeled high cloud behavior and for evaluating the realism of modeled high cloud changes in response to a variety of forcings.

  6. Temperature dependence for the absolute rate constant for the reaction CH/sub 2/OH + O/sub 2/. -->. HO/sub 2/ + H/sub 2/CO from 215 to 300 K

    SciTech Connect

    Nesbitt, F.L.; Payne, W.A.; Stief, L.J.

    1988-07-14

    The absolute rate constant for the reaction CH/sub 2/OH + O/sub 2/ ..-->.. HO/sub 2/ + H/sub 2/CO has been determined from 215 to 300 K in a discharge flow system at 1-Torr pressure. The decay of CH/sub 2/OH was monitored in excess O/sub 2/ by collision-free sampling mass spectrometry. The temperature dependence observed is quite different from the usual Arrhenius form. For the 215-250 K interval, an activation energy of 3.4 kcal/mol is obtained. Above 250 K, the rate constant increases at a slower rate; previous high-temperature studies (1000-2000 K) again show a faster increase in the rate constant. A possible explanation for these observations is that the reaction mechanism changes from addition at low temperature to direct abstraction at high temperatures.

  7. The contribution of greenhouse gases to the recent slowdown in global-mean temperature trends

    NASA Astrophysics Data System (ADS)

    Checa-Garcia, R.; Shine, K. P.; Hegglin, M. I.

    2016-09-01

    The recent slowdown in the rate of increase in global-mean surface temperature (GMST) has generated extensive discussion, but little attention has been given to the contribution of time-varying trends in greenhouse gas concentrations. We use a simple model approach to quantify this contribution. Between 1985 and 2003, greenhouse gases (including well-mixed greenhouse gases, tropospheric and stratospheric ozone, and stratospheric water vapour from methane oxidation) caused a reduction in GMST trend of around 0.03-0.05 K decade-1 which is around 18%-25% of the observed trend over that period. The main contributors to this reduction are the rapid change in the growth rates of ozone-depleting gases (with this contribution slightly opposed by stratospheric ozone depletion itself) and the weakening in growth rates of methane and tropospheric ozone radiative forcing. Although CO2 is the dominant greenhouse gas contributor to GMST trends, the continued increase in CO2 concentrations offsets only about 30% of the simulated trend reduction due to these other contributors. These results emphasize that trends in non-CO2 greenhouse gas concentrations can make significant positive and negative contributions to changes in the rate of warming, and that they need to be considered more closely in analyses of the causes of such variations.

  8. R-vine models for spatial time series with an application to daily mean temperature.

    PubMed

    Erhardt, Tobias Michael; Czado, Claudia; Schepsmeier, Ulf

    2015-06-01

    We introduce an extension of R-vine copula models to allow for spatial dependencies and model based prediction at unobserved locations. The proposed spatial R-vine model combines the flexibility of vine copulas with the classical geostatistical idea of modeling spatial dependencies using the distances between the variable locations. In particular, the model is able to capture non-Gaussian spatial dependencies. To develop and illustrate our approach, we consider daily mean temperature data observed at 54 monitoring stations in Germany. We identify relationships between the vine copula parameters and the station distances and exploit these in order to reduce the huge number of parameters needed to parametrize a 54-dimensional R-vine model fitted to the data. The new distance based model parametrization results in a distinct reduction in the number of parameters and makes parameter estimation and prediction at unobserved locations feasible. The prediction capabilities are validated using adequate scoring techniques, showing a better performance of the spatial R-vine copula model compared to a Gaussian spatial model.

  9. On the Trend of the Annual Mean, Maximum, and Minimum Temperature and the Diurnal Temperature Range in the Armagh Observatory, Northern Ireland, Dataset, 1844 -2012

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2013-01-01

    Examined are the annual averages, 10-year moving averages, decadal averages, and sunspot cycle (SC) length averages of the mean, maximum, and minimum surface air temperatures and the diurnal temperature range (DTR) for the Armagh Observatory, Northern Ireland, during the interval 1844-2012. Strong upward trends are apparent in the Armagh surface-air temperatures (ASAT), while a strong downward trend is apparent in the DTR, especially when the ASAT data are averaged by decade or over individual SC lengths. The long-term decrease in the decadaland SC-averaged annual DTR occurs because the annual minimum temperatures have risen more quickly than the annual maximum temperatures. Estimates are given for the Armagh annual mean, maximum, and minimum temperatures and the DTR for the current decade (2010-2019) and SC24.

  10. System for controlling absolute humidity in a work area

    SciTech Connect

    Norris, P.K.; Oliver, P.S.

    1987-05-05

    A system is described for controlling absolute humidity of air which is removed from an area, passed through an air washer and returned through a duct to the area. The system comprises: a first sensor located within the area for generating a first signal representative of the absolute humidity of air within the area; a second sensor located in a discharge air plenum portion of the washer for generating a second signal representative of the dry bulb temperature of air discharged from the washer; and control means responsive to the first and second signals for producing a third signal which is applied to the washer to control the dry bulb temperature of air discharged from the washer.

  11. Daily Mean Temperature and Clinical Kidney Stone Presentation in Five U.S. Metropolitan Areas: A Time-Series Analysis

    PubMed Central

    Pulido, Jose E.; Gasparrini, Antonio; Saigal, Christopher S.; Horton, Benjamin P.; Landis, J. Richard; Madison, Rodger; Keren, Ron

    2014-01-01

    Background: High ambient temperatures are a risk factor for nephrolithiasis, but the precise relationship between temperature and kidney stone presentation is unknown. Objectives: Our objective was to estimate associations between mean daily temperature and kidney stone presentation according to lag time and temperatures. Methods: Using a time-series design and distributed lag nonlinear models, we estimated the relative risk (RR) of kidney stone presentation associated with mean daily temperatures, including cumulative RR for a 20-day period, and RR for individual daily lags through 20 days. Our analysis used data from the MarketScan Commercial Claims database for 60,433 patients who sought medical evaluation or treatment of kidney stones from 2005–2011 in the U.S. cities of Atlanta, Georgia; Chicago, Illinois; Dallas, Texas; Los Angeles, California; and Philadelphia, Pennsylvania. Results: Associations between mean daily temperature and kidney stone presentation were not monotonic, and there was variation in the exposure–response curve shapes and the strength of associations at different temperatures. However, in most cases RRs increased for temperatures above the reference value of 10°C. The cumulative RR for a daily mean temperature of 30°C versus 10°C was 1.38 in Atlanta (95% CI: 1.07, 1.79), 1.37 in Chicago (95% CI: 1.07, 1.76), 1.36 in Dallas (95% CI: 1.10, 1.69), 1.11 in Los Angeles (95% CI: 0.73, 1.68), and 1.47 in Philadelphia (95% CI: 1.00, 2.17). Kidney stone presentations also were positively associated with temperatures < 2°C in Atlanta, and < 10°C in Chicago and Philadelphia. In four cities, the strongest association between kidney stone presentation and a daily mean temperature of 30°C versus 10°C was estimated for lags of ≤ 3 days. Conclusions: In general, kidney stone presentations increased with higher daily mean temperatures, with the strongest associations estimated for lags of only a few days. These findings further support an

  12. The role of Atlantic Multi-decadal Oscillation in the global mean temperature variability

    SciTech Connect

    Chylek, Petr; Klett, James D.; Dubey, Manvendra K.; Hengartner, Nicolas

    2016-11-01

    We simulated the global mean 1900–2015 warming by 42 Coupled Models Inter-comparison Project, phase 5 (CMIP5) climate models varies between 0.58 and 1.70 °C. The observed warming according to the NASA GISS temperature analysis is 0.95 °C with a 1200 km smoothing radius, or 0.86 °C with a 250 km smoothing radius. The projection of the future 2015–2100 global warming under a moderate increase of anthropogenic radiative forcing (RCP4.5 scenario) by individual models is between 0.7 and 2.3 °C. The CMIP5 climate models agree that the future climate will be warmer; however, there is little consensus as to how large the warming will be (reflected by an uncertainty of over a factor of three). Moreover, a parsimonious statistical regression model with just three explanatory variables [anthropogenic radiative forcing due to greenhouse gases and aerosols (GHGA), solar variability, and the Atlantic Multi-decadal Oscillation (AMO) index] accounts for over 95 % of the observed 1900–2015 temperature variance. This statistical regression model reproduces very accurately the past warming (0.96 °C compared to the observed 0.95 °C) and projects the future 2015–2100 warming to be around 0.95 °C (with the IPCC 2013 suggested RCP4.5 radiative forcing and an assumed cyclic AMO behavior). The AMO contribution to the 1970–2005 warming was between 0.13 and 0.20 °C (depending on which AMO index is used) compared to the GHGA contribution of 0.49–0.58 °C. During the twenty-first century AMO cycle the AMO contribution is projected to remain the same (0.13–0.20 °C), while the GHGA contribution is expected to decrease to 0.21–0.25 °C due to the levelling off of the GHGA radiative forcing that is assumed according to the RCP4.5 scenario. Therefore, the anthropogenic contribution and natural variability are expected to contribute about equally to the anticipated global warming during the second half of the twenty-first century for the RCP4.5 trajectory.

  13. The role of Atlantic Multi-decadal Oscillation in the global mean temperature variability

    NASA Astrophysics Data System (ADS)

    Chylek, Petr; Klett, James D.; Dubey, Manvendra K.; Hengartner, Nicolas

    2016-11-01

    The global mean 1900-2015 warming simulated by 42 Coupled Models Inter-comparison Project, phase 5 (CMIP5) climate models varies between 0.58 and 1.70 °C. The observed warming according to the NASA GISS temperature analysis is 0.95 °C with a 1200 km smoothing radius, or 0.86 °C with a 250 km smoothing radius. The projection of the future 2015-2100 global warming under a moderate increase of anthropogenic radiative forcing (RCP4.5 scenario) by individual models is between 0.7 and 2.3 °C. The CMIP5 climate models agree that the future climate will be warmer; however, there is little consensus as to how large the warming will be (reflected by an uncertainty of over a factor of three). A parsimonious statistical regression model with just three explanatory variables [anthropogenic radiative forcing due to greenhouse gases and aerosols (GHGA), solar variability, and the Atlantic Multi-decadal Oscillation (AMO) index] accounts for over 95 % of the observed 1900-2015 temperature variance. This statistical regression model reproduces very accurately the past warming (0.96 °C compared to the observed 0.95 °C) and projects the future 2015-2100 warming to be around 0.95 °C (with the IPCC 2013 suggested RCP4.5 radiative forcing and an assumed cyclic AMO behavior). The AMO contribution to the 1970-2005 warming was between 0.13 and 0.20 °C (depending on which AMO index is used) compared to the GHGA contribution of 0.49-0.58 °C. During the twenty-first century AMO cycle the AMO contribution is projected to remain the same (0.13-0.20 °C), while the GHGA contribution is expected to decrease to 0.21-0.25 °C due to the levelling off of the GHGA radiative forcing that is assumed according to the RCP4.5 scenario. Thus the anthropogenic contribution and natural variability are expected to contribute about equally to the anticipated global warming during the second half of the twenty-first century for the RCP4.5 trajectory.

  14. The role of Atlantic Multi-decadal Oscillation in the global mean temperature variability

    DOE PAGES

    Chylek, Petr; Klett, James D.; Dubey, Manvendra K.; ...

    2016-11-01

    We simulated the global mean 1900–2015 warming by 42 Coupled Models Inter-comparison Project, phase 5 (CMIP5) climate models varies between 0.58 and 1.70 °C. The observed warming according to the NASA GISS temperature analysis is 0.95 °C with a 1200 km smoothing radius, or 0.86 °C with a 250 km smoothing radius. The projection of the future 2015–2100 global warming under a moderate increase of anthropogenic radiative forcing (RCP4.5 scenario) by individual models is between 0.7 and 2.3 °C. The CMIP5 climate models agree that the future climate will be warmer; however, there is little consensus as to how largemore » the warming will be (reflected by an uncertainty of over a factor of three). Moreover, a parsimonious statistical regression model with just three explanatory variables [anthropogenic radiative forcing due to greenhouse gases and aerosols (GHGA), solar variability, and the Atlantic Multi-decadal Oscillation (AMO) index] accounts for over 95 % of the observed 1900–2015 temperature variance. This statistical regression model reproduces very accurately the past warming (0.96 °C compared to the observed 0.95 °C) and projects the future 2015–2100 warming to be around 0.95 °C (with the IPCC 2013 suggested RCP4.5 radiative forcing and an assumed cyclic AMO behavior). The AMO contribution to the 1970–2005 warming was between 0.13 and 0.20 °C (depending on which AMO index is used) compared to the GHGA contribution of 0.49–0.58 °C. During the twenty-first century AMO cycle the AMO contribution is projected to remain the same (0.13–0.20 °C), while the GHGA contribution is expected to decrease to 0.21–0.25 °C due to the levelling off of the GHGA radiative forcing that is assumed according to the RCP4.5 scenario. Therefore, the anthropogenic contribution and natural variability are expected to contribute about equally to the anticipated global warming during the second half of the twenty-first century for the RCP4.5 trajectory.« less

  15. Optomechanics for absolute rotation detection

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar

    2016-07-01

    In this article, we present an application of optomechanical cavity for the absolute rotation detection. The optomechanical cavity is arranged in a Michelson interferometer in such a way that the classical centrifugal force due to rotation changes the length of the optomechanical cavity. The change in the cavity length induces a shift in the frequency of the cavity mode. The phase shift corresponding to the frequency shift in the cavity mode is measured at the interferometer output to estimate the angular velocity of absolute rotation. We derived an analytic expression to estimate the minimum detectable rotation rate in our scheme for a given optomechanical cavity. Temperature dependence of the rotation detection sensitivity is studied.

  16. Effect of mean annual temperature on nutrient return via litterfall in Hawaiian tropical montane wet forests

    NASA Astrophysics Data System (ADS)

    Litton, C. M.; Freeman, K. R.; Giardina, C. P.; Selmants, P.

    2012-12-01

    Rising temperatures are predicted to influence nutrient cycling and availability in terrestrial ecosystems. Changes in nutrient availability, in turn, have important implications for terrestrial ecosystem C cycling and storage. However, the magnitude and direction of temperature-induced changes in nutrient availability, as well as variations across important micro- and macronutrients, remain poorly constrained, particularly in tropical forests which play a disproportionately large role in global C cycling. The return of nutrients to soil via aboveground litterfall is a sensitive, integrated index of stand-level biogeochemical process rates. As a result, quantifying the response of nutrient return via litterfall to increases in mean annual temperature (MAT) can yield valuable insights into how whole ecosystems will respond to future warming. We examined the effects of MAT on nutrient return via litterfall over one year for nine nutrients (N, P, Ca, Mg, K, Mn, Cu, Zn and Fe) in tropical montane wet forests located across a highly constrained MAT gradient where N and P are believed to co-limit stand-level productivity. Specifically, we analyzed stand-level patterns of litterfall mass, nutrient return via litterfall, and nutrient use efficiencies across nine permanent plots spanning a 5.2°C MAT gradient (13.0 to 18.2°C; corresponding to 1,600 to 800 m a.s.l) on the Island of Hawaii. Litterfall mass increased linearly and positively with MAT, indicating that stand-level productivity increases with MAT. The return of N, K, Mg and Zn via litterfall also increased linearly with MAT, while the return of Cu via litterfall decreased linearly with MAT. Nutrient use efficiencies increased linearly with MAT for Cu and Mn, and decreased linearly with MAT for K, Mg and Zn. No patterns in P cycling were evident, despite that it is believed to co-limit productivity in these forests based on prior fertilization experiments. These data suggest that increasing MAT will increase the

  17. Intrinsic optimum temperature of the diamondback moth and its ecological meaning.

    PubMed

    Shi, Peijian; Li, Bai-Lian; Ge, Feng

    2012-06-01

    Temperature can notably affect development rate and intrinsic rate of increase of the diamondback moth, Plutella xylostella L. The intrinsic rate of increase is usually regarded as a good measure of fitness in insects, and the constant temperature at which the intrinsic rate of increase reaches its maximum is defined as the "optimal" temperature for an insect species to survive. The estimates of optimal temperature for some insects and mites are ~30°C. However, the Sharpe-Schoolfield-Ikemoto model provides an estimate about the intrinsic optimum temperature at which the probability of an enzyme being in the active state is maximal. The intrinsic optimum temperature is considered to be the most suitable temperature for an insect species to survive. The estimates of intrinsic optimum temperature for some insects and mites are ~20°C. The optimal temperature and the intrinsic optimum temperature of the diamondback moth were estimated in the current study. The former estimate is 28.4 (95% CI: 26.2-28.8°C), whereas the latter estimate is 19.4°C (95% CI: 17.9-20.5°C). Considering the daily average air temperatures during the peaks of the diamondback moth in China, the intrinsic optimum temperature of 19.4°C might represent the most suitable temperature for this insect to survive. We also discussed whether it is sounded to use the intrinsic rate of increase as the fitness. Because the intrinsic rate of increase cannot reflect the density-dependence of population and the trade-off between individual body mass and population size, it is inappropriate to equate these two concepts.

  18. Absolute CF{sub 2} density and gas temperature measurements by absorption spectroscopy in dual-frequency capacitively coupled CF{sub 4}/Ar plasmas

    SciTech Connect

    Liu, Wen-Yao; Xu, Yong Peng, Fei; Gong, Fa-Ping; Li, Xiao-Song; Zhu, Ai-Min; Liu, Yong-Xin; Wang, You-Nian

    2014-10-15

    Broadband ultraviolet absorption spectroscopy has been used to determine the CF{sub 2} radical density in dual-frequency capacitively coupled CF{sub 4}/Ar plasmas, using the CF{sub 2} A{sup ~1}B{sub 1}←X{sup ~1}A{sub 1} system of absorption spectrum. The rotational temperature of ground state CF{sub 2} and excited state CF was also estimated by using A{sup ~1}B{sub 1}←X{sup ~1}A{sub 1} system and B{sup 2}Δ−X{sup 2}Π system, respectively. The translational gas temperature was deduced from the Doppler width of the Ar{sup *}({sup 3}P{sub 2}) and Ar{sup *}({sup 3}P{sub 0}) metastable atoms absorption line by using the tunable diode laser absorption spectroscopy. The rotational temperatures of the excited state CF are about 100 K higher than those of ground state CF{sub 2}, and about 200 K higher than the translational gas temperatures. The dependences of the radical CF{sub 2} density, electron density, electron temperature, rotational temperature, and gas temperature on the high frequency power and pressure have been analyzed. Furthermore, the production and loss mechanisms of CF{sub 2} radical and the gas heating mechanisms have also been discussed.

  19. Absolute CF2 density and gas temperature measurements by absorption spectroscopy in dual-frequency capacitively coupled CF4/Ar plasmas

    NASA Astrophysics Data System (ADS)

    Liu, Wen-Yao; Xu, Yong; Liu, Yong-Xin; Peng, Fei; Gong, Fa-Ping; Li, Xiao-Song; Zhu, Ai-Min; Wang, You-Nian

    2014-10-01

    Broadband ultraviolet absorption spectroscopy has been used to determine the CF2 radical density in dual-frequency capacitively coupled CF4/Ar plasmas, using the CF2 A ˜ 1 B 1 ← X ˜ 1 A 1 system of absorption spectrum. The rotational temperature of ground state CF2 and excited state CF was also estimated by using A ˜ 1 B 1 ← X ˜ 1 A 1 system and B 2 Δ - X 2 Π system, respectively. The translational gas temperature was deduced from the Doppler width of the Ar*(3P2) and Ar*(3P0) metastable atoms absorption line by using the tunable diode laser absorption spectroscopy. The rotational temperatures of the excited state CF are about 100 K higher than those of ground state CF2, and about 200 K higher than the translational gas temperatures. The dependences of the radical CF2 density, electron density, electron temperature, rotational temperature, and gas temperature on the high frequency power and pressure have been analyzed. Furthermore, the production and loss mechanisms of CF2 radical and the gas heating mechanisms have also been discussed.

  20. Absolute neutrino mass scale

    NASA Astrophysics Data System (ADS)

    Capelli, Silvia; Di Bari, Pasquale

    2013-04-01

    Neutrino oscillation experiments firmly established non-vanishing neutrino masses, a result that can be regarded as a strong motivation to extend the Standard Model. In spite of being the lightest massive particles, neutrinos likely represent an important bridge to new physics at very high energies and offer new opportunities to address some of the current cosmological puzzles, such as the matter-antimatter asymmetry of the Universe and Dark Matter. In this context, the determination of the absolute neutrino mass scale is a key issue within modern High Energy Physics. The talks in this parallel session well describe the current exciting experimental activity aiming to determining the absolute neutrino mass scale and offer an overview of a few models beyond the Standard Model that have been proposed in order to explain the neutrino masses giving a prediction for the absolute neutrino mass scale and solving the cosmological puzzles.

  1. Study on a mean radiant temperature measure tool based on an almost spherical array of radiometric sensors.

    PubMed

    Fontana, L

    2012-11-01

    Mean radiant temperature has significant influence on indoor thermal comfort conditions. It has gained greater importance with the wider application of heating and cooling systems based on the use of large surfaces with a temperature slightly higher or lower than the indoor temperature (hot/cold floors or ceilings), because these systems operate through the radiant temperature control. The most used tool to measure radiant temperature, the globe thermometer, still has large margins of error, most of all due to the uncertainty in the evaluation of the convection heat exchanges between the globe surface and the indoor air. The feasibility of a device to measure mean radiant temperature in indoor condition, alternative to the globe-thermometer (obtained placing radiometric sensors (thermopiles) on the sides of different geometric regular solids), is proposed. The behavior has been investigated for different regular solids, such as the residual error and its dependence on walls average temperature, non-uniformity magnitude, orientation and position of the solid in the enclosure, room shape, non-uniformity temperature distribution. Icosahedron shape shows an excellent behavior, with errors lower than 0.1 K in all the examined conditions.

  2. Study on a mean radiant temperature measure tool based on an almost spherical array of radiometric sensors

    NASA Astrophysics Data System (ADS)

    Fontana, L.

    2012-11-01

    Mean radiant temperature has significant influence on indoor thermal comfort conditions. It has gained greater importance with the wider application of heating and cooling systems based on the use of large surfaces with a temperature slightly higher or lower than the indoor temperature (hot/cold floors or ceilings), because these systems operate through the radiant temperature control. The most used tool to measure radiant temperature, the globe thermometer, still has large margins of error, most of all due to the uncertainty in the evaluation of the convection heat exchanges between the globe surface and the indoor air. The feasibility of a device to measure mean radiant temperature in indoor condition, alternative to the globe-thermometer (obtained placing radiometric sensors (thermopiles) on the sides of different geometric regular solids), is proposed. The behavior has been investigated for different regular solids, such as the residual error and its dependence on walls average temperature, non-uniformity magnitude, orientation and position of the solid in the enclosure, room shape, non-uniformity temperature distribution. Icosahedron shape shows an excellent behavior, with errors lower than 0.1 K in all the examined conditions.

  3. The absolute path command

    SciTech Connect

    Moody, A.

    2012-05-11

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

  4. Changes in mean and extreme temperature and precipitation over the arid region of northwestern China: Observation and projection

    NASA Astrophysics Data System (ADS)

    Wang, Yujie; Zhou, Botao; Qin, Dahe; Wu, Jia; Gao, Rong; Song, Lianchun

    2017-03-01

    This paper reports a comprehensive study on the observed and projected spatiotemporal changes in mean and extreme climate over the arid region of northwestern China, based on gridded observation data and CMIP5 simulations under the RCP4.5 and RCP8.5 scenarios. The observational results reveal an increase in annual mean temperature since 1961, largely attributable to the increase in minimum temperature. The annual mean precipitation also exhibits a significant increasing tendency. The precipitation amount in the most recent decade was greater than in any preceding decade since 1961. Seasonally, the greatest increase in temperature and precipitation appears in winter and in summer, respectively. Widespread significant changes in temperature-related extremes are consistent with warming, with decreases in cold extremes and increases in warm extremes. The warming of the coldest night is greater than that of the warmest day, and changes in cold and warm nights are more evident than for cold and warm days. Extreme precipitation and wet days exhibit an increasing trend, and the maximum number of consecutive dry days shows a tendency toward shorter duration. Multi-model ensemble mean projections indicate an overall continual increase in temperature and precipitation during the 21st century. Decreases in cold extremes, increases in warm extremes, intensification of extreme precipitation, increases in wet days, and decreases in consecutive dry days, are expected under both emissions scenarios, with larger changes corresponding to stronger radiative forcing.

  5. Inference of Global Mean Temperature Trend and Climate Change from MSU and AMSU

    NASA Technical Reports Server (NTRS)

    Prabhakara, Cuddapah; Iacovazzi, R. A., Jr.; Yoo, J.-M.; Lau, William K. M. (Technical Monitor)

    2001-01-01

    Microwave Sounding Unit (MSU) and Advanced MSU (AMSU) radiometers flown on the NOAA operational satellite series are potentially valuable as global temperature monitoring devices. Spencer and Christy pioneered the analysis of mid-tropospheric temperature, given by MSU Channel 2 (Ch 2) at 53.74 GHz, to derive the global temperature trend. Also, in addition to monitoring global temperature, these microwave radiometers have the potential to reveal interannual climate signals in tropics. We have analyzed the data of MSU Ch 2 and AMSU Ch 5 (53.6 GHz) from the NOAA operational satellites for the period 1980 to 2000, utilizing the NOAA calibration procedure. The data are corrected for the satellite orbital drift based on the temporal changes of the on-board warm blackbody temperature. From our analysis, we find that the global temperature increased at a rate of 0.13 +/- 0.05 Kdecade(sup -1) during 1980 to 2000. From an Empirical Orthogonal Function (EOF) analysis of the MSU global data, we find that the mid-tropospheric temperature in middle and high latitudes responds to the ENSO forcing during the Northern Hemisphere Winter in a distinct manner. This mid-latitude response is opposite in phase to that in the tropics. This result is in accord with simulations performed with an ECMWF global spectral model. This study shows a potential use of the satellite observations for climatic change.

  6. Stratospheric dynamical effects of solar ultraviolet variations: Evidence from zonal mean ozone and temperature data

    SciTech Connect

    Hood, L.L.; Jirikowic, J.L. )

    1991-04-20

    Cross-spectral analysis of low-altitude average Nimbus 7 stratospheric and mesospheric sounder (SAMS) temperature deviations versus Nimbus 7 solar backscattered ultraviolet (SBUV) solar 205 nm flux measurements in the 1-3 mbar pressure range yields significant coherence at periods near 27 and 13 days. This supports earlier correlative evidence that the ozone response to solar ultraviolet variations is supplemented by a coupled temperature response in the upper stratosphere. Comparisons of improved one-dimensional radiative photochemical model calculations with ozone and temperature response measurements at low latitudes yields agreement only in the case of ozone at levels below 3 mbar. An additional, presumably dynamical, component of the upper stratospheric response is suggested. Cross-spectral analysis of low-latitude average SAMS temperature deviations versus higher-latitude temperature fluctuations of opposite sign in the winter hemisphere also yields significant coherency at periods near 27 and 13 days. Latitudinal temperature oscillations of this type result from interference between stationary and traveling wave components at stratospheric heights. It is therefore hypothesized that solar ultraviolet variations may force or modulate traveling waves with periods near 27 and 13 days in the upper stratosphere. The existence of such waves with higher amplitude near solar maximum than near solar minimum may help to explain observed solar cycle variations of zonally averaged winds and temperature in the upper stratosphere.

  7. Analysis of trait mean and variability versus temperature in trematode cercariae: is there scope for adaptation to global warming?

    PubMed

    Studer, A; Poulin, R

    2014-05-01

    The potential of species for evolutionary adaptation in the context of global climate change has recently come under scrutiny. Estimates of phenotypic variation in biological traits may prove valuable for identifying species, or groups of species, with greater or lower potential for evolutionary adaptation, as this variation, when heritable, represents the basis for natural selection. Assuming that measures of trait variability reflect the evolutionary potential of these traits, we conducted an analysis across trematode species to determine the potential of these parasites as a group to adapt to increasing temperatures. Firstly, we assessed how the mean number of infective stages (cercariae) emerging from infected snail hosts as well as the survival and infectivity of cercariae are related to temperature. Secondly and importantly in the context of evolutionary potential, we assessed how coefficients of variation for these traits are related to temperature, in both cases controlling for other factors such as habitat, acclimatisation, latitude and type of target host. With increasing temperature, an optimum curve was found for mean output and mean infectivity, and a linear decrease for survival of cercariae. For coefficients of variation, temperature was only an important predictor in the case of cercarial output, where results indicated that there is, however, no evidence for limited trait variation at the higher temperature range. No directional trend was found for either variation of survival or infectivity. These results, characterising general patterns among trematodes, suggest that all three traits considered may have potential to change through adaptive evolution.

  8. Evidence of Non-Mean-Field-Like Low-Temperature Behavior in the Edwards-Anderson Spin-Glass Model

    NASA Astrophysics Data System (ADS)

    Yucesoy, B.; Katzgraber, Helmut G.; Machta, J.

    2012-10-01

    The three-dimensional Edwards-Anderson and mean-field Sherrington-Kirkpatrick Ising spin glasses are studied via large-scale Monte Carlo simulations at low temperatures, deep within the spin-glass phase. Performing a careful statistical analysis of several thousand independent disorder realizations and using an observable that detects peaks in the overlap distribution, we show that the Sherrington-Kirkpatrick and Edwards-Anderson models have a distinctly different low-temperature behavior. The structure of the spin-glass overlap distribution for the Edwards-Anderson model suggests that its low-temperature phase has only a single pair of pure states.

  9. Mean surface temperature prediction models for broiler chickens—a study of sensible heat flow

    NASA Astrophysics Data System (ADS)

    Nascimento, Sheila Tavares; da Silva, Iran José Oliveira; Maia, Alex Sandro Campos; de Castro, Ariane Cristina; Vieira, Frederico Marcio Corrêa

    2014-03-01

    Body surface temperature can be used to evaluate thermal equilibrium in animals. The bodies of broiler chickens, like those of all birds, are partially covered by feathers. Thus, the heat flow at the boundary layer between broilers' bodies and the environment differs between feathered and featherless areas. The aim of this investigation was to use linear regression models incorporating environmental parameters and age to predict the surface temperatures of the feathered and featherless areas of broiler chickens. The trial was conducted in a climate chamber, and 576 broilers were distributed in two groups. In the first trial, 288 broilers were monitored after exposure to comfortable or stressful conditions during a 6-week rearing period. Another 288 broilers were measured under the same conditions to test the predictive power of the models. Sensible heat flow was calculated, and for the regions covered by feathers, sensible heat flow was predicted based on the estimated surface temperatures. The surface temperatures of the feathered and featherless areas can be predicted based on air, black globe or operative temperatures. According to the sensible heat flow model, the broilers' ability to maintain thermal equilibrium by convection and radiation decreased during the rearing period. Sensible heat flow estimated based on estimated surface temperatures can be used to predict animal responses to comfortable and stressful conditions.

  10. Multi-Species Temperature and Proxy Reconstructions of the Tropical Pacific Mean State across Marine Isotope Stage 3

    NASA Astrophysics Data System (ADS)

    Hertzberg, J. E.; Schmidt, M. W.

    2015-12-01

    The current climatic mean state of the Pacific is characterized by trade wind induced upwelling of cold water in the east and accumulation of warm surface waters in the west, resulting in a strong E-W sea surface temperature (SST) gradient. The initiation and propagation of ENSO events are due to perturbations in this system. Changes in the mean state have the potential to alter ENSO-related processes, feedbacks, and properties. However, it remains unclear how ENSO feedbacks interact as the mean state changes - an increasingly important question as current climate warms, potentially altering the mean state. Here, we use the abrupt climate warming events of Marine Isotope Stage 3 from 32-64 kyr as a natural experiment for understanding how the tropical Pacific mean state varied across past periods of rapid climate warming. We measured Mg/Ca ratios in the thermocline dwelling planktonic foraminifera N. dutertrei as a proxy for thermocline temperature variability from Eastern Pacific sediment core MV1014-17JC (0°10.8'S, 85°52.0'W). Reconstructing subsurface temperatures removes the seasonal cycle imprint on SSTs, and instead, thermocline temperatures vary with ENSO conditions. Our record reveals that interstadial warming events are characterized by a more El Niño-like mean state, characterized by increased thermocline temperatures up to 6°C. Thermocline warming events are more pronounced from 64-44 kyr when overall global climate was in a warmer state. Moving from 44-32 kyr, our record shows cooler thermocline temperatures, suggesting a shift to a more La Niña-like mean state, as climate began transitioning into the Glacial Maximum. We also measured Mg/Ca ratios in the surface dwelling planktonic foraminifera G. ruber. Our G. ruber SST record displays the same cooling trend as the N. dutertrei record from 64-32 kyr. SSTs cool 1-1.5°C while thermocline temperatures cool 2.5-3°C. Preliminary comparison with a SST record from the Western Pacific suggests a

  11. Multi-Species Temperature and Proxy Reconstructions of the Tropical Pacific Mean State across Marine Isotope Stage 3

    NASA Astrophysics Data System (ADS)

    Hendry, K. R.; Pike, J.; McManus, J. F.; Robinson, L. F.

    2014-12-01

    The current climatic mean state of the Pacific is characterized by trade wind induced upwelling of cold water in the east and accumulation of warm surface waters in the west, resulting in a strong E-W sea surface temperature (SST) gradient. The initiation and propagation of ENSO events are due to perturbations in this system. Changes in the mean state have the potential to alter ENSO-related processes, feedbacks, and properties. However, it remains unclear how ENSO feedbacks interact as the mean state changes - an increasingly important question as current climate warms, potentially altering the mean state. Here, we use the abrupt climate warming events of Marine Isotope Stage 3 from 32-64 kyr as a natural experiment for understanding how the tropical Pacific mean state varied across past periods of rapid climate warming. We measured Mg/Ca ratios in the thermocline dwelling planktonic foraminifera N. dutertrei as a proxy for thermocline temperature variability from Eastern Pacific sediment core MV1014-17JC (0°10.8'S, 85°52.0'W). Reconstructing subsurface temperatures removes the seasonal cycle imprint on SSTs, and instead, thermocline temperatures vary with ENSO conditions. Our record reveals that interstadial warming events are characterized by a more El Niño-like mean state, characterized by increased thermocline temperatures up to 6°C. Thermocline warming events are more pronounced from 64-44 kyr when overall global climate was in a warmer state. Moving from 44-32 kyr, our record shows cooler thermocline temperatures, suggesting a shift to a more La Niña-like mean state, as climate began transitioning into the Glacial Maximum. We also measured Mg/Ca ratios in the surface dwelling planktonic foraminifera G. ruber. Our G. ruber SST record displays the same cooling trend as the N. dutertrei record from 64-32 kyr. SSTs cool 1-1.5°C while thermocline temperatures cool 2.5-3°C. Preliminary comparison with a SST record from the Western Pacific suggests a

  12. About the physical meaning of the critical temperature for catastrophic optical damage in high power quantum well laser diodes

    NASA Astrophysics Data System (ADS)

    Souto, J.; Pura, J. L.; Jiménez, J.

    2016-02-01

    It is usually assumed that the catastrophic optical damage of high power laser diodes is launched when a critical local temperature (T c) is reached; temperatures ranging from 120 °C to 200 °C were experimentally reported. However, the physical meaning of T c in the degradation process is still unclear. In this work we show that, in the presence of a local heat source in the active region, the temperature of the laser structure, calculated using finite element methods, is widely inhomogeneously distributed among the different layers forming the device. This is due to the impact that the low dimensionality and the thermal boundary resistances have on the thermal transport across the laser structure. When these key factors are explicitly considered, the quantum well (QW) temperature can be several hundred degrees higher than the temperature of the guides and cladding layers. Due to the size of the experimental probes, the measured critical temperature is a weighted average over the QW, guides, and claddings. We show the existence of a large difference between the calculated average temperature, equivalent to the experimentally measured temperature, and the peak temperature localized in the QW. A parallel study on double heterostructure lasers is also included for comparison.

  13. Nuclear matter properties in the relativistic mean-field theory at finite temperature with interaction between sigma-omega mesons

    SciTech Connect

    Costa, R. S.; Duarte, S. B.; Oliveira, J. C. T.; Chiapparini, M.

    2010-05-21

    We study the nuclear matter properties in the regime of high temperatures using a relativistic mean-field theory. Contrasting with the usual linear Walecka model, we include the sigma-omega meson coupling in order to investigate the role of this interaction in the nucleon effective mass behavior. Some numerical results are presented and discussed.

  14. Hadronic matter at finite temperature and density within an effective relativistic mean-field model

    NASA Astrophysics Data System (ADS)

    Lavagno, A.

    2012-10-01

    We study hot and dense hadronic matter by means of an effective relativistic mean-field model with the inclusion of the full octet of baryons, the Δ-isobar degrees of freedom and the lightest pseudoscalar and vector mesons. These last particles are considered by taking into account an effective chemical potential and an effective mass depending on the self-consistent interaction between baryons. The analysis is performed by requiring the Gibbs conditions on the global conservation of baryon number, electric charge fraction and zero net strangeness.

  15. Monthly Mean Time Series of Temperature and Salinity in Monterey Bay, 1951-1991

    DTIC Science & Technology

    1991-12-01

    series, themal conditions, water mass, seasonal changes 19 ABSTRACT (continue on reverse if necessary and identify by block number) Temperature and...STUDIES ........ ............... 1 B. PURPOSE ........... .................... 2 C. GENERAL DESCRIPTION OF STUDY AREA .... ....... 3 D. CALFORNIA CURRENT...SYSTEM ...... ........... 5 E. SEASONAL CHANGES IN MONTEREY BAY .... ....... 8 1. The Davidson Current Period .... ........ 8 2. The Upwelling Period

  16. Detecting and adjusting temporal inhomogeneity in Chinese mean surface air temperature data

    NASA Astrophysics Data System (ADS)

    Li, Qingxiang; Liu, Xiaoning; Zhang, Hongzheng; Thomas C., Peterson; David R., Easterling

    2004-04-01

    Adopting the Easterling-Peterson (EP) techniques and considering the reality of Chinese meteorological observations, this paper designed several tests and tested for inhomogeneities in all Chinese historical surface air temperature series from 1951 to 2001. The result shows that the time series have been widely impacted by inhomogeneities resulting from the relocation of stations and changes in local environment such as urbanization or some other factors. Among these factors, station relocations caused the largest magnitude of abrupt changes in the time series, and other factors also resulted in inhomogeneities to some extent. According to the amplitude of change of the difference series and the monthly distribution features of surface air temperatures, discontinuities identified by applying both the E-P technique and supported by China’s station history records, or by comparison with other approaches, have been adjusted. Based on the above processing, the most significant temporal inhomogeneities were eliminated, and China’s most homogeneous surface air temperature series has thus been created. Results show that the inhomogeneity testing captured well the most important change of the stations, and the adjusted dataset is more reliable than ever. This suggests that the adjusted temperature dataset has great value of decreasing the uncertaities in the study of observed climate change in China.

  17. Scale-dependency of the global mean surface temperature trend and its implication for the recent hiatus of global warming

    PubMed Central

    Lin, Yong; Franzke, Christian L. E.

    2015-01-01

    Studies of the global mean surface temperature trend are typically conducted at a single (usually annual or decadal) time scale. The used scale does not necessarily correspond to the intrinsic scales of the natural temperature variability. This scale mismatch complicates the separation of externally forced temperature trends from natural temperature fluctuations. The hiatus of global warming since 1999 has been claimed to show that human activities play only a minor role in global warming. Most likely this claim is wrong due to the inadequate consideration of the scale-dependency in the global surface temperature (GST) evolution. Here we show that the variability and trend of the global mean surface temperature anomalies (GSTA) from January 1850 to December 2013, which incorporate both land and sea surface data, is scale-dependent and that the recent hiatus of global warming is mainly related to natural long-term oscillations. These results provide a possible explanation of the recent hiatus of global warming and suggest that the hiatus is only temporary. PMID:26259555

  18. Scale-dependency of the global mean surface temperature trend and its implication for the recent hiatus of global warming.

    PubMed

    Lin, Yong; Franzke, Christian L E

    2015-08-11

    Studies of the global mean surface temperature trend are typically conducted at a single (usually annual or decadal) time scale. The used scale does not necessarily correspond to the intrinsic scales of the natural temperature variability. This scale mismatch complicates the separation of externally forced temperature trends from natural temperature fluctuations. The hiatus of global warming since 1999 has been claimed to show that human activities play only a minor role in global warming. Most likely this claim is wrong due to the inadequate consideration of the scale-dependency in the global surface temperature (GST) evolution. Here we show that the variability and trend of the global mean surface temperature anomalies (GSTA) from January 1850 to December 2013, which incorporate both land and sea surface data, is scale-dependent and that the recent hiatus of global warming is mainly related to natural long-term oscillations. These results provide a possible explanation of the recent hiatus of global warming and suggest that the hiatus is only temporary.

  19. The link between the solar dynamo and climate - The evidence from a long mean air temperature series from Northern Ireland

    NASA Astrophysics Data System (ADS)

    Butler, C. J.; Johnston, D. J.

    1994-09-01

    It has been shown by Friis-Christensen and Lassen (1991) that there is a close correspondence in the behavior of the mean northern hemisphere air temperature and the length of the sunspot cycle, over the period 1861-1990. This result would appear to be of considerable importance for studies of both past and future climate and suggests that as the solar dynamo speeds up it causes, by some process as yet unknown, an increase in the temperature of the Earth's troposphere. In this paper we extend the comparison between sunspot cycle length and temperature back to the late 18th century using data accumulated at Armagh Observatory since 1795. Our data strongly support the contention that solar variability has been the principal cause of temperature changes over the past two centuries.

  20. Selective determination of methyl mercury in biological samples by means of programmed temperature gas chromatography.

    PubMed

    Lorenzo, R A; Carro, A; Rubí, E; Casais, C; Cela, R

    1993-01-01

    A programmed temperature gas chromatographic method is presented by which it is possible to carry out routine analysis of methyl mercury in biological samples prepared according to the AOAC official first action recommendations without the need for preliminary treatment of the columns. This method greatly extends the life of the columns as well as the useful time for analysis; it has good linearity and repeatability. With the proposed method a total of 36 samples can be analyzed daily.

  1. Intraseasonal Variations in Tropical Deep Convection, Tropospheric Mean Temperature and Cloud-Induced Radiative Fluxes

    NASA Technical Reports Server (NTRS)

    Ramey, Holly S.; Robertson, Franklin R.

    2009-01-01

    Intraseasonal variability of deep convection represents a fundamental mode of variability in the organization of tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, we examine the projection of ISOs on the tropically-averaged temperature and energy budget. The area of interest is the global oceans between 20oN/S. Our analysis then focuses on these questions: (i) How is tropospheric temperature related to tropical deep convection and the associated ice cloud fractional amount (ICF) and ice water path (IWP)? (ii) What is the source of moisture sustaining the convection and what role does deep convection play in mediating the PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007) with some modifications and some additional diagnostics of both clouds and boundary layer thermodynamics. A composite ISO time series of cloud, precipitation and radiation quantities built from nearly 40 events during a six-year period is referenced to the atmospheric temperature signal. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. While there is a decrease in net TOA radiation that develops after the peak in deep convective rainfall, there seems little evidence that an "Infrared Iris"- like mechanism is dominant. Rather, the cloud-induced OLR increase seems largely produced by weakened convection with warmer cloud tops. Tropical ISO events offer an accessible target for studying ISOs not just in terms of propagation mechanisms, but on their global signals of heat, moisture and radiative flux feedback processes.

  2. Cryogenic temperature control by means of energy storage materials. [for long space voyages

    NASA Technical Reports Server (NTRS)

    Grodzka, P. G.; Picklesimer, E. A.; Connor, L. E.

    1977-01-01

    An investigation was conducted to study the concept of thermal control by means of physical or chemical reaction heats for applications involving the storage of cryogens during long-term space voyages. The investigation included some preliminary experimental tests of energy storage material (ESM) effectiveness. The materials considered can store and liberate large amounts of thermal energy by means of mechanisms such as sensible heat, heat of fusion, and physical or chemical reaction heat. A differential thermal analysis was utilized in the laboratory tests. Attention is given to the evaluation of cryogenic ESM thermal control concepts, the experimental determination of phase change materials characteristics, and adsorption ESMs. It is found that an ESM shield surrounded by multiple layer insulation provides the best protection for a cryogen store.

  3. Millimeter wave radiometry as a means of determining cometary surface and subsurface temperature

    NASA Technical Reports Server (NTRS)

    Hobbs, R. W.; Brandt, J. C.; Maran, S. P.

    1981-01-01

    Thermal emission spectra for a variety of cometary nucleus models were evaluated by a radiative transfer technique adapted from modeling of terrestrial ice and snow fields. It appears that millimeter wave sensing from an interplanetary spacecraft is the most effective available means for distinguishing between alternate models of the nucleus and for evaluating the thermal state of the layer which is below the instantaneous surface where modern theories of the nucleus indicate that sublimation of the cometary volatiles actually occurs.

  4. Diagnostics of Rotational Temperature and Mean Electron Energy Distribution of DC Glow Discharge Using Spectral Image Processing

    NASA Astrophysics Data System (ADS)

    Shimizu, Daisuke; Sasamoto, Ryo; Matsumoto, Takao; Izawa, Yasuji; Nishijima, Kiyoto

    2014-10-01

    The non-thermal plasma has been used in various application fields of manufacturing industry such as surface reforming, plasma etching, deposited film forming. The gas temperature and electron energy in non-thermal plasma play a key role of production of active species. Therefore, it is essential to understand the properties of non-thermal plasma for effective plasma applications. In this study, the two-dimensional rotational temperature and mean electron energy distribution of DC glow discharge plasma under various air pressures were observed using spectral image processing. Rotational temperature distribution was estimated from the emission intensity ratio of head and tail of 2nd positive system band of N2 (0, 2). On the other hand, mean electron energy was estimated from the emission intensity ratio of 2nd positive system band of N2 (0, 2) and 1st negative system band of N2+ (0, 0). The each spectral images were taken by an ICCD camera with narrow band-path filters respectively. As a result, the dependences of rotational temperature and mean electron energy distribution in DC glow discharge on ambient air pressure were clearly observed using spectral image processing.

  5. Trends of mean and extreme temperature indices since 1874 at low-elevation sites in the southern Alps

    NASA Astrophysics Data System (ADS)

    Brugnara, Yuri; Auchmann, Renate; Brönnimann, Stefan; Bozzo, Alessio; Berro, Daniele Cat; Mercalli, Luca

    2016-04-01

    We describe the recovery of three daily meteorological records for the southern Alps (Domodossola, Riva del Garda, and Rovereto), all starting in the second half of the nineteenth century. We use these new data, along with additional records, to study regional changes in the mean temperature and extreme indices of heat waves and cold spells frequency and duration over the period 1874-2015. The records are homogenized using subdaily cloud cover observations as a constraint for the statistical model, an approach that has never been applied before in the literature. A case study based on a record of parallel observations between a traditional meteorological window and a modern screen shows that the use of cloud cover can reduce the root-mean-square error of the homogenization by up to 30% in comparison to an unaided statistical correction. We find that mean temperature in the southern Alps has increased by 1.4°C per century over the analyzed period, with larger increases in daily minimum temperatures than maximum temperatures. The number of hot days in summer has more than tripled, and a similar increase is observed in duration of heat waves. Cold days in winter have dropped at a similar rate. These trends are mainly caused by climate change over the last few decades.

  6. GASEOUS MEAN OPACITIES FOR GIANT PLANET AND ULTRACOOL DWARF ATMOSPHERES OVER A RANGE OF METALLICITIES AND TEMPERATURES

    SciTech Connect

    Freedman, Richard S.; Lustig-Yaeger, Jacob; Fortney, Jonathan J.; Lupu, Roxana E.; Marley, Mark S.; Lodders, Katharina

    2014-10-01

    We present new calculations of Rosseland and Planck gaseous mean opacities relevant to the atmospheres of giant planets and ultracool dwarfs. Such calculations are used in modeling the atmospheres, interiors, formation, and evolution of these objects. Our calculations are an expansion of those presented in Freedman et al. to include lower pressures, finer temperature resolution, and also the higher metallicities most relevant for giant planet atmospheres. Calculations span 1 μbar to 300 bar, and 75-4000 K, in a nearly square grid. Opacities at metallicities from solar to 50 times solar abundances are calculated. We also provide an analytic fit to the Rosseland mean opacities over the grid in pressure, temperature, and metallicity. In addition to computing mean opacities at these local temperatures, we also calculate them with weighting functions up to 7000 K, to simulate the mean opacities for incident stellar intensities, rather than locally thermally emitted intensities. The chemical equilibrium calculations account for the settling of condensates in a gravitational field and are applicable to cloud-free giant planet and ultracool dwarf atmospheres, but not circumstellar disks. We provide our extensive opacity tables for public use.

  7. An improved empirical dynamic control system model of global mean sea level rise and surface temperature change

    NASA Astrophysics Data System (ADS)

    Wu, Qing; Luu, Quang-Hung; Tkalich, Pavel; Chen, Ge

    2017-03-01

    Having great impacts on human lives, global warming and associated sea level rise are believed to be strongly linked to anthropogenic causes. Statistical approach offers a simple and yet conceptually verifiable combination of remotely connected climate variables and indices, including sea level and surface temperature. We propose an improved statistical reconstruction model based on the empirical dynamic control system by taking into account the climate variability and deriving parameters from Monte Carlo cross-validation random experiments. For the historic data from 1880 to 2001, we yielded higher correlation results compared to those from other dynamic empirical models. The averaged root mean square errors are reduced in both reconstructed fields, namely, the global mean surface temperature (by 24-37%) and the global mean sea level (by 5-25%). Our model is also more robust as it notably diminished the unstable problem associated with varying initial values. Such results suggest that the model not only enhances significantly the global mean reconstructions of temperature and sea level but also may have a potential to improve future projections.

  8. Gaseous Mean Opacities for Giant Planet and Ultracool Dwarf Atmospheres over a Range of Metallicities and Temperatures

    NASA Astrophysics Data System (ADS)

    Freedman, Richard S.; Lustig-Yaeger, Jacob; Fortney, Jonathan J.; Lupu, Roxana E.; Marley, Mark S.; Lodders, Katharina

    2014-10-01

    We present new calculations of Rosseland and Planck gaseous mean opacities relevant to the atmospheres of giant planets and ultracool dwarfs. Such calculations are used in modeling the atmospheres, interiors, formation, and evolution of these objects. Our calculations are an expansion of those presented in Freedman et al. to include lower pressures, finer temperature resolution, and also the higher metallicities most relevant for giant planet atmospheres. Calculations span 1 μbar to 300 bar, and 75-4000 K, in a nearly square grid. Opacities at metallicities from solar to 50 times solar abundances are calculated. We also provide an analytic fit to the Rosseland mean opacities over the grid in pressure, temperature, and metallicity. In addition to computing mean opacities at these local temperatures, we also calculate them with weighting functions up to 7000 K, to simulate the mean opacities for incident stellar intensities, rather than locally thermally emitted intensities. The chemical equilibrium calculations account for the settling of condensates in a gravitational field and are applicable to cloud-free giant planet and ultracool dwarf atmospheres, but not circumstellar disks. We provide our extensive opacity tables for public use.

  9. Ratios of Record High to Record Low Temperatures in Europe Show an Accelerating Trend Since 2000 Despite a Slowdown in Mean Temperature Trends

    NASA Astrophysics Data System (ADS)

    Beniston, M.

    2014-12-01

    The present study has examined the behavior of extreme high and low temperatures in Euirope since the mid-20th century, in terms of the ratio of number of days per year with record Tmax and record Tmin. The investigations have shown that there has been a clear and massive increase in the number of high Tmax: low Tmin ratios in the most recent decade of the 1951-2013 temperature record for 30 selected observation stations in Europe. This sharp increase is seen to occur despite an apparent hiatus - or at least a reduction in the rate of warming - since the early 2000s, as observed not only in Europe but on a hemispheric basis too. The «explosion» of record high:record low temperature ratios since 2000, despite relatively small increases in mean temperatures in the last 10-15 years of the observational record, can be explained by a non-linear (quadratic) relation between mean temperatures and the Tmax:Tmin record ratios. It is suggested here that the increases are probably a consequence of increasing dryness during the summer in the Mediterranean region (where today there are on average 30 more dry days than in the 1950s), and a reduction in the cold season conducive to snow days in Arctic summers and Northern European springs (with up to 40 days less freezing days than 60 years previously). Both effects can serve to amplify positive temperature feedbacks in the lower atmosphere that result in strong increases in the number of Tmax record high temperatures and correspondingly strong reductions in the number of Tmin record low temperatures.

  10. Climate-change impact on the 20th-century relationship between the Southern Annular Mode and global mean temperature

    PubMed Central

    Wang, Guojian; Cai, Wenju

    2013-01-01

    The positive phase of the El Niño-Southern Oscillation (ENSO) increases global mean temperature, and contributes to a negative phase of the Southern Annular Mode (SAM), the dominant mode of climate variability in the Southern Hemisphere. This interannual relationship of a high global mean temperature associated with a negative SAM, however, is opposite to the relationship between their trends under greenhouse warming. We show that over much of the 20th century this relationship undergoes multidecadal fluctuations depending on the intensity of ENSO. During the period 1925–1955, subdued ENSO activities weakened the relationship. However, a similar weakening has occurred since the late 1970s despite the strong ENSO. We demonstrate that this recent weakening is induced by climate change in the Southern Hemisphere. Our result highlights a rare situation in which climate change signals emerge against an opposing property of interannual variability, underscoring the robustness of the recent climate change. PMID:23784087

  11. Intra-seasonal Oscillations (ISO) of Zonal-Mean Meridional Winds and Temperatures as Measured by UARS

    NASA Technical Reports Server (NTRS)

    Huang, Frank T.; Mayr, Hans G.; Reber, Carl A.

    2004-01-01

    Based on an empirical analysis of measurements with the High Resolution Doppler Imager (HRDI) on the UARS spacecraft in the upper mesosphere (95 km), persistent and regular intra-seasonal oscillations (ISO) with periods of about 2 to 4 months have recently been reported in the zonal-mean meridional winds. Similar oscillations have also been discussed independently in a modeling study, and they were attributed to wave-mean-flow interactions. The observed and modeled meridional wind ISOs were largely confined to low latitudes. We report here an analysis of concurrent temperature measurements on UARS, which produces oscillations similar to those seen in the meridional winds. Although the temperature oscillations are observed at lower altitudes (55 km), their phase variations with latitude are qualitatively consistent with the inferred properties seen in the meridional winds and thus provide independent evidence for the existence of ISOs in the mesosphere.

  12. A chironomid-based mean July temperature inference model from the south-east margin of the Tibetan Plateau, China

    NASA Astrophysics Data System (ADS)

    Zhang, Enlou; Chang, Jie; Cao, Yanmin; Tang, Hongqu; Langdon, Pete; Shulmeister, James; Wang, Rong; Yang, Xiangdong; Shen, Ji

    2017-03-01

    A chironomid-based calibration training set comprised of 100 lakes from south-western China was established. Multivariate ordination analyses were used to investigate the relationship between the distribution and abundance of chironomid species and 18 environmental variables from these lakes. Canonical correspondence analyses (CCAs) and partial CCAs showed that mean July temperature is one of the independent and significant variables explaining the second-largest amount of variance after potassium ions (K+) in 100 south-western Chinese lakes. Quantitative transfer functions were created using the chironomid assemblages for this calibration data set. The second component of the weighted-average partial least squares (WA-PLS) model produced a coefficient of determination (r2bootstrap) of 0.63, maximum bias (bootstrap) of 5.16 and root-mean-square error of prediction (RMSEP) of 2.31 °C. We applied the transfer functions to a 150-year chironomid record from Tiancai Lake (26°38'3.8 N, 99°43' E; 3898 m a.s.l.), Yunnan, China, to obtain mean July temperature inferences. We validated these results by applying several reconstruction diagnostics and comparing them to a 50-year instrumental record from the nearest weather station (26°51'29.22'' N, 100°14'2.34'' E; 2390 m a.s.l.). The transfer function performs well in this comparison. We argue that this 100-lake large training set is suitable for reconstruction work despite the low explanatory power of mean July temperature because it contains a complete range of modern temperature and environmental data for the chironomid taxa observed and is therefore robust.

  13. Electronic Absolute Cartesian Autocollimator

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B.

    2006-01-01

    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

  14. Evidence of Non-Mean-Field-Like Low-Temperature Behavior in the Edwards-Anderson Spin-Glass Model

    NASA Astrophysics Data System (ADS)

    Yucesoy, Burcu; Katzgraber, Helmut G.; Machta, Jonathan

    2013-03-01

    The three and four-dimensional Edwards-Anderson and mean-field Sherrington-Kirkpatrick Ising spin glasses are studied via large-scale Monte Carlo simulations at low temperatures, deep within the spin-glass phase. Performing a careful statistical analysis of several thousand independent disorder realizations and using an observable that detects peaks in the overlap distribution, we show that the Sherrington-Kirkpatrick and Edwards-Anderson models have a distinctly different low-temperature behavior. The structure of the spin-glass overlap distribution for the Edwards-Anderson model suggests that its low-temperature phase has only a single pair of pure states. J. M. and B. Y. are supported in part by the NSF (Grant No. DMR-0907235 and DMR-1208046).

  15. Investigating high mortality during the cold season: mapping mean weather patterns of temperature and pressure

    NASA Astrophysics Data System (ADS)

    Allen, Michael J.; Lee, Cameron C.

    2014-11-01

    Due to a number of complicating factors, cold-related mortality has long been understudied. Through a synoptic climatological, environment-to-circulation perspective, this research takes a unique approach in examining anomalous surface temperature and pressure map patterns associated with the days leading up to high-mortality, spike days for Chicago, Illinois during the cold season. Atmospheric conditions leading to spike days during the cold season were evaluated through both seasonal anomaly and 1-day anomaly maps. Results indicate that high-mortality days are typically preceded by unseasonably cold weather situated over the region from 2 to 5 days beforehand, with significantly higher than average pressure 1 to 2 days before a mortality spike. As this system moves eastward, a significant 1-day warming trend accompanying a significant drop in sea level pressure follows—occurring on the day of the mortality spike or 1 day prior. Both scenarios—cold, high pressure air exposure and the rapid change in weather—are consistent with previous literature connecting them as factors contributing to cold-related mortality increases, with this sequence possibly playing a key role in yielding mortality levels anomalous enough to meet the threshold for a spike.

  16. A Dynamic Approach to Addressing Observation-Minus-Forecast Mean Differences in a Land Surface Skin Temperature Data Assimilation System

    NASA Technical Reports Server (NTRS)

    Draper, Clara; Reichle, Rolf; De Lannoy, Gabrielle; Scarino, Benjamin

    2015-01-01

    In land data assimilation, bias in the observation-minus-forecast (O-F) residuals is typically removed from the observations prior to assimilation by rescaling the observations to have the same long-term mean (and higher-order moments) as the corresponding model forecasts. Such observation rescaling approaches require a long record of observed and forecast estimates, and an assumption that the O-F mean differences are stationary. A two-stage observation bias and state estimation filter is presented, as an alternative to observation rescaling that does not require a long data record or assume stationary O-F mean differences. The two-stage filter removes dynamic (nonstationary) estimates of the seasonal scale O-F mean difference from the assimilated observations, allowing the assimilation to correct the model for synoptic-scale errors without adverse effects from observation biases. The two-stage filter is demonstrated by assimilating geostationary skin temperature (Tsk) observations into the Catchment land surface model. Global maps of the O-F mean differences are presented, and the two-stage filter is evaluated for one year over the Americas. The two-stage filter effectively removed the Tsk O-F mean differences, for example the GOES-West O-F mean difference at 21:00 UTC was reduced from 5.1 K for a bias-blind assimilation to 0.3 K. Compared to independent in situ and remotely sensed Tsk observations, the two-stage assimilation reduced the unbiased Root Mean Square Difference (ubRMSD) of the modeled Tsk by 10 of the open-loop values.

  17. Absolute-structure reports.

    PubMed

    Flack, Howard D

    2013-08-01

    All the 139 noncentrosymmetric crystal structures published in Acta Crystallographica Section C between January 2011 and November 2012 inclusive have been used as the basis of a detailed study of the reporting of absolute structure. These structure determinations cover a wide range of space groups, chemical composition and resonant-scattering contribution. Defining A and D as the average and difference of the intensities of Friedel opposites, their level of fit has been examined using 2AD and selected-D plots. It was found, regardless of the expected resonant-scattering contribution to Friedel opposites, that the Friedel-difference intensities are often dominated by random uncertainty and systematic error. An analysis of data collection strategy is provided. It is found that crystal-structure determinations resulting in a Flack parameter close to 0.5 may not necessarily be from crystals twinned by inversion. Friedifstat is shown to be a robust estimator of the resonant-scattering contribution to Friedel opposites, very little affected by the particular space group of a structure nor by the occupation of special positions. There is considerable confusion in the text of papers presenting achiral noncentrosymmetric crystal structures. Recommendations are provided for the optimal way of treating noncentrosymmetric crystal structures for which the experimenter has no interest in determining the absolute structure.

  18. Bias correction of global and regional simulated daily precipitation and surface mean temperature over Southeast Asia using quantile mapping method

    NASA Astrophysics Data System (ADS)

    Ngai, Sheau Tieh; Tangang, Fredolin; Juneng, Liew

    2017-02-01

    A trend preserving quantile mapping (QM) method was applied to adjust the biases of the global and regional climate models (GCM and RCMs) simulated daily precipitation and surface mean temperature over Southeast Asia regions based on APHRODITE dataset. Output from four different RCMs as well as their driving GCM in CORDEX-EA archive were corrected to examine the added value of RCMs dynamical downscaling in the context of bias adjustment. The result shows that the RCM biases are comparable to that of the GCM biases. In some instances, RCMs amplified the GCM biases. Generally, QM method substantially improves the biases for both precipitation and temperature. However, the bias adjustment method works better for surface mean temperature and less so for daily precipitation. The large inter-models variability is reduced remarkably after bias adjustment. Overall, study indicates no strong evident that RCMs downscaling as an immediate step before bias correction provides additional improvement to the sub-regional climate compared to the correction directly carried out on their forcing GCM.

  19. Global-mean temperature change from shipping toward 2050: improved representation of the indirect aerosol effect in simple climate models.

    PubMed

    Lund, Marianne Tronstad; Eyring, Veronika; Fuglestvedt, Jan; Hendricks, Johannes; Lauer, Axel; Lee, David; Righi, Mattia

    2012-08-21

    We utilize a range of emission scenarios for shipping to determine the induced global-mean radiative forcing and temperature change. Ship emission scenarios consistent with the new regulations on nitrogen oxides (NO(x)) and sulfur dioxide (SO(2)) from the International Maritime Organization and two of the Representative Concentration Pathways are used as input to a simple climate model (SCM). Based on a complex aerosol-climate model we develop and test new parametrizations of the indirect aerosol effect (IAE) in the SCM that account for nonlinearities in radiative forcing of ship-induced IAE. We find that shipping causes a net global cooling impact throughout the period 1900-2050 across all parametrizations and scenarios. However, calculated total net global-mean temperature change in 2050 ranges from -0.03[-0.07,-0.002]°C to -0.3[-0.6,-0.2]°C in the A1B scenario. This wide range across parametrizations emphasizes the importance of properly representing the IAE in SCMs and to reflect the uncertainties from complex global models. Furthermore, our calculations show that the future ship-induced temperature response is likely a continued cooling if SO(2) and NO(x) emissions continue to increase due to a strong increase in activity, despite current emission regulations. However, such cooling does not negate the need for continued efforts to reduce CO(2) emissions, since residual warming from CO(2) is long-lived.

  20. Absolute Radiation Thermometry in the NIR

    NASA Astrophysics Data System (ADS)

    Bünger, L.; Taubert, R. D.; Gutschwager, B.; Anhalt, K.; Briaudeau, S.; Sadli, M.

    2017-04-01

    A near infrared (NIR) radiation thermometer (RT) for temperature measurements in the range from 773 K up to 1235 K was characterized and calibrated in terms of the "Mise en Pratique for the definition of the Kelvin" (MeP-K) by measuring its absolute spectral radiance responsivity. Using Planck's law of thermal radiation allows the direct measurement of the thermodynamic temperature independently of any ITS-90 fixed-point. To determine the absolute spectral radiance responsivity of the radiation thermometer in the NIR spectral region, an existing PTB monochromator-based calibration setup was upgraded with a supercontinuum laser system (0.45 μm to 2.4 μm) resulting in a significantly improved signal-to-noise ratio. The RT was characterized with respect to its nonlinearity, size-of-source effect, distance effect, and the consistency of its individual temperature measuring ranges. To further improve the calibration setup, a new tool for the aperture alignment and distance measurement was developed. Furthermore, the diffraction correction as well as the impedance correction of the current-to-voltage converter is considered. The calibration scheme and the corresponding uncertainty budget of the absolute spectral responsivity are presented. A relative standard uncertainty of 0.1 % (k=1) for the absolute spectral radiance responsivity was achieved. The absolute radiometric calibration was validated at four temperature values with respect to the ITS-90 via a variable temperature heatpipe blackbody (773 K ...1235 K) and at a gold fixed-point blackbody radiator (1337.33 K).

  1. Comparative analysis of insect succession data from Victoria (Australia) using summary statistics versus preceding mean ambient temperature models.

    PubMed

    Archer, Mel

    2014-03-01

    Minimum postmortem interval (mPMI) can be estimated with preceding mean ambient temperature models that predict carrion taxon pre-appearance interval. But accuracy has not been compared with using summary statistics (mean ± SD of taxon arrival/departure day, range, 95% CI). This study collected succession data from ten experimental and five control (infrequently sampled) pig carcasses over two summers (n = 2 experimental, n = 1 control per placement date). Linear and exponential preceding mean ambient temperature models for appearance and departure times were constructed for 17 taxa/developmental stages. There was minimal difference in linear or exponential model success, although arrival models were more often significant: 65% of linear arrival (r2 = 0.09–0.79) and exponential arrival models (r2 = 0.05–81.0) were significant, and 35% of linear departure (r2 = 0.0–0.71) and exponential departure models (r2 = 0.0–0.72) were significant. Performance of models and summary statistics for estimating mPMI was compared in two forensic cases. Only summary statistics produced accurate mPMI estimates.

  2. Absolute Equilibrium Entropy

    NASA Technical Reports Server (NTRS)

    Shebalin, John V.

    1997-01-01

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

  3. Absolute multilateration between spheres

    NASA Astrophysics Data System (ADS)

    Muelaner, Jody; Wadsworth, William; Azini, Maria; Mullineux, Glen; Hughes, Ben; Reichold, Armin

    2017-04-01

    Environmental effects typically limit the accuracy of large scale coordinate measurements in applications such as aircraft production and particle accelerator alignment. This paper presents an initial design for a novel measurement technique with analysis and simulation showing that that it could overcome the environmental limitations to provide a step change in large scale coordinate measurement accuracy. Referred to as absolute multilateration between spheres (AMS), it involves using absolute distance interferometry to directly measure the distances between pairs of plain steel spheres. A large portion of each sphere remains accessible as a reference datum, while the laser path can be shielded from environmental disturbances. As a single scale bar this can provide accurate scale information to be used for instrument verification or network measurement scaling. Since spheres can be simultaneously measured from multiple directions, it also allows highly accurate multilateration-based coordinate measurements to act as a large scale datum structure for localized measurements, or to be integrated within assembly tooling, coordinate measurement machines or robotic machinery. Analysis and simulation show that AMS can be self-aligned to achieve a theoretical combined standard uncertainty for the independent uncertainties of an individual 1 m scale bar of approximately 0.49 µm. It is also shown that combined with a 1 µm m‑1 standard uncertainty in the central reference system this could result in coordinate standard uncertainty magnitudes of 42 µm over a slender 1 m by 20 m network. This would be a sufficient step change in accuracy to enable next generation aerospace structures with natural laminar flow and part-to-part interchangeability.

  4. Comparison of Variability of the Monthly Mean Temperature of the ECMWF and NCEP Reanalyses and CCM3 and CSM Simulations

    SciTech Connect

    Boyle, J.

    2000-03-01

    The low frequency variation in the three dimensional air temperature fields of two reanalyses and two model simulations are described. The data sets used are the monthly mean temperature fields for the NCAR Climate Simulation Model (CSM, Boville and Gent, 1998) 300 year run, a NCAR Community Climate Model version 3 (CCM3, Kiehl et al., 1998) AMIP type simulation, and the NCEP/NCAR and ECMWF (ERA) reanalysis data sets. The variances and correlations are computed for the anomalies from the annual cycle for each data set. In general the reanalyses and models agree fairly well on the structure of the temperature variance. The models tend to have too much variance at the surface compared to the reanalyses. The CSMs poor simulation of the SST in the eastern Pacific leads to a much reduced variance in the Nino3 region. The enhanced variability over land appears to affect the midlatitude simulation of the CSM in that the higher surface variability extends off the east coast of continents. This is not evident in CCM3 and reanalyses where the SSTs are prescribed. At 200 hPa the CCM3 and reanalyses all evince the dumb bell pattern straddling the Equator in the eastern Pacific attributed by Yulaeva and Wallace (1994) to ENSO variations. The CSM shows no such pattern. A CCM3 integration using climatological SSTs displays more variance that the CSM in this region. Apparently the coupling to an ocean in the CSM suppresses the atmospheric model's variability in this locale. The correlations of the temperature fields with the surface air temperature show that the regions of subtropical subsidence are virtually uncorrelated to the surface at the 700 hPa level. The regions of the cold water off the west coast of continents evince decoupling with the surface at 850 hPa. In the region from 30S to 30N the zonal mean correlation falls to about 0.7 below 800 hPa, with this value extending up to about 600 hPa in mid and upper latitudes. These characteristics are consistent across all the

  5. Comparison of Variability of the Monthly Mean Temperature of the ECMWF and NCEP Reanalyses and CCM3 and DSM Simulations

    SciTech Connect

    Boyle, J.S.

    2000-02-16

    The low frequency variation in the three dimensional air temperature fields of two reanalyses and two model simulations are described. The data sets used are the monthly mean temperature fields for the NCAR Climate Simulation Model (CSM, Boville and Gent, 1998) 300 year run, a NCAR Community Climate Model version 3 (CCM3, Kiehl et al., 1998) AMIP type simulation, and the NCEPLNCAR and ECMWF (ERA) reanalysis data sets. The variances and correlations are computed for the anomalies from the annual cycle for each data set. In general the reanalyses and models agree fairly well on the structure of the temperature variance. The models tend to have too much variance at the surface compared to the reanalyses. The CSM's poor simulation of the SST in the eastern Pacific leads to a much reduced variance in the Nino3 region. The enhanced variability over land appears to affect the midlatitude simulation of the CSM in that the higher surface variability extends off the east coast of continents. This is not evident in CCM3 and reanalyses where the SSTs are prescribed. At 200 hPa the CCM3 and reanalyses all evince the dumb bell pattern straddling the Equator in the eastern Pacific attributed by Yulaeva and Wallace (1994) to ENS0 variations. The CSM shows no such pattern. A CCM3 integration using climatological SSTs displays more variance that the CSM in this region, apparently the CSM suppresses variability in this locale. The correlations of the temperature fields with the surface air temperature show that the regions of subtropical subsidence are virtually uncorrelated to the surface at the 700 hPa level. The regions of the cold water off the west coast of continents evince decoupling with the surface at 850 hPa. In the region from 30s to 30N the zonal mean correlation falls to about 0.7 below 800 hPa, with this value extending up to about 600 hPa in mid and upper latitudes. These characteristics are consistent across all the data sets. Thus, the variations of vertically

  6. Radiative analysis of global mean temperature trends in the middle atmosphere: Effects of non-locality and secondary absorption bands

    NASA Astrophysics Data System (ADS)

    Fomichev, V. I.; Jonsson, A. I.; Ward, W. E.

    2016-02-01

    In this paper, we provide a refined and extended assignment of past and future temperature changes relative to previous analyses and describe and evaluate the relevance of vertical coupling and non-linear and secondary radiative mechanisms for the interpretation of climatic temperature variations in the middle atmosphere. Because of their nature, the latter mechanisms are not adequately accounted for in most regression analyses of temperature trends as a function of local constituent variations. These mechanisms are examined using (1) globally averaged profiles from transient simulations with the Canadian Middle Atmosphere Model (CMAM) forced by changes in greenhouse gases and ozone depleting substances and (2) a one-dimensional radiative-equilibrium model forced using the diagnosed global mean changes in radiatively active constituents as derived from the CMAM model runs. The conditions during the periods 1975 to 1995 and 2010 to 2040 (during which the rates of change in ozone and CO2 differ) provide a suitable contrast for the role of the non-linear and non-local mechanisms being evaluated in this paper to be clearly differentiated and evaluated. Vertical coupling of radiative transfer effects and the influence of secondary absorption bands are important enough to render the results of multiple linear regression analyses between the temperature response and constituent changes misleading. These effects are evaluated in detail using the 1D radiative-equilibrium model using profiles from the CMAM runs as inputs. In order to explain the differences in the CMAM temperature trends prior to and after 2000 these other radiative effects must be considered in addition to local changes in the radiatively active species. The middle atmosphere temperature cools in response to CO2 and water vapor increases, but past and future trends are modulated by ozone changes.

  7. Intercomparison of planetary-scale diagnostics derived from separate satellite and radiosonde time-mean temperature fields

    NASA Technical Reports Server (NTRS)

    Miles, T.; Chapman, W. A.

    1984-01-01

    The planetary-scale components of the extratropical Northern Hemisphere troposphere-stratosphere 1973-74 winter circulation are diagnosed using separate time-mean temperature fields based on radiosonde and satellite observations. Meridional cross-sections of zonal wind together with, for zonal wavenumbers 1, 2 and 3, the streamfunction amplitude, phase and Eliassen-Palm flux are displayed, with the relative accuracy of the satellite-derived diagnostics assessed through comparison with the 'ground-truth' radiosonde information. The satellite and radiosonde diagnostics compare most favourably in terms of zonal wind speed and shear, direction of wave propagation and meridional wave structure - all of which are closely related to the differential properties of the atmospheric temperature field. The intensity of the satellite-derived patterns of tropospheric wave propagation is underestimated due to the effects of spatial smoothing and residual cloud contamination present in the satellite radiance measurements.

  8. Boundary layer fluctuations and their effects on mean and variance temperature profiles in turbulent Rayleigh-Bénard convection

    NASA Astrophysics Data System (ADS)

    Wang, Yin; He, Xiaozhou; Tong, Penger

    2016-12-01

    We report simultaneous measurements of the mean temperature profile θ (z ) and temperature variance profile η (z ) near the lower conducting plate of a specially designed quasi-two-dimensional cell for turbulent Rayleigh-Bénard convection. The measured θ (z ) is found to have a universal scaling form θ (z /δ ) with varying thermal boundary layer (BL) thickness δ , and its functional form agrees well with the recently derived BL equation by Shishkina et al. [Phys. Rev. Lett. 114, 114302 (2015), 10.1103/PhysRevLett.114.114302]. The measured η (z ) , on the other hand, is found to have a scaling form η (z /δ ) only in the near-wall region with z /δ ≲2 . Based on the experimental findings, we derive a BL equation for η (z /δ ) , which is in good agreement with the experimental results. These BL equations thus provide a common framework for understanding the effect of BL fluctuations.

  9. TX model: a quantitative heat-loss analysis of district heating pipes by means of IR surface-temperature measurements

    NASA Astrophysics Data System (ADS)

    Zinko, Heimo; Perers, Bengt

    1995-03-01

    The aim of this study is to investigate the possibility of analyzing the temperature profile at the ground surface above buried district heating pipes in such a way that enables the quantitative determination of heat loss from the pair of pipes. In practical applications, it is supposed that this temperature profile is generated by means of thermography. For this purpose, the principle of the TX-model has been developed, implementing that the heat losses from pipes buried in the ground has a temperature signature on the ground surface. A qualitative analysis of this temperature signature is very well known and in practical use for detecting leaks from pipes. These techniques mostly makes use of relative changes of the temperature pattern along the pipe. In the quantitative heat loss analysis, however, it is presumed that the temperature profile across the pipes is related to the pipe heat loss in Watt/m. The basic idea is that the integral of the temperature variation across the pipe, called TX, is a function of the heat loss, but affected by some other parameters such as depth, heat diffusivity and so on. In order to analyze the parameters influencing the TX-factor, a simulation model for the energy balance at the ground surface has been developed. This model includes the heat flow from the pipe to the surface and the heat exchange at the surface with the environment due to convection, latent heat change, solar and long wave radiation. The simulation gives the surprising result that the TX factor is relatively unaffected during the course of a day even when the sun is shining, as long as other climate conditions are relatively stable (low wind, no rain, no shadows). The results from the simulations were verified at a testfield in Studsvik, Sweden, with electrically controlled pipe heat losses and long term monitoring of the surface temperature profile and TX factor with temperature sensors at the ground surface. The quantitative TX model for heat loss

  10. Statistical downscaling of sub-daily (6-hour) temperature in Romania, by means of artificial neural networks

    NASA Astrophysics Data System (ADS)

    Birsan, Marius-Victor; Dumitrescu, Alexandru; Cǎrbunaru, Felicia

    2016-04-01

    The role of statistical downscaling is to model the relationship between large-scale atmospheric circulation and climatic variables on a regional and sub-regional scale, making use of the predictions of future circulation generated by General Circulation Models (GCMs) in order to capture the effects of climate change on smaller areas. The study presents a statistical downscaling model based on a neural network-based approach, by means of multi-layer perceptron networks. Sub-daily temperature data series from 81 meteorological stations over Romania, with full data records are used as predictands. As large-scale predictor, the NCEP/NCAD air temperature data at 850 hPa over the domain 20-30E / 40-50N was used, at a spatial resolution of 2.5×2.5 degrees. The period 1961-1990 was used for calibration, while the validation was realized over the 1991-2010 interval. Further, in order to estimate future changes in air temperature for 2021-2050 and 2071-2100, air temperature data at 850 hPa corresponding to the IPCC A1B scenario was extracted from the CNCM33 model (Meteo-France) and used as predictor. This work has been realized within the research project "Changes in climate extremes and associated impact in hydrological events in Romania" (CLIMHYDEX), code PN II-ID-2011-2-0073, financed by the Romanian Executive Agency for Higher Education Research, Development and Innovation Funding (UEFISCDI).

  11. Large-scale climate variability and its effects on mean temperature and flowering time of Prunus and Betula in Denmark

    NASA Astrophysics Data System (ADS)

    Gormsen, A. K.; Hense, A.; Toldam-Andersen, T. B.; Braun, P.

    2005-08-01

    Large-scale climate variability largely affects average climatic conditions and therefore is likely to influence the phenology of plants. In NW-Europe, the North Atlantic Oscillation (NAO) particularly influences winter climate and, through climate interactions on plants, flowering time of all tree species. In Denmark, like in many other NW-European countries, flowering of most tree species has become earlier since the end of the 1980’s. To quantify a possible relation between NAO and flowering time of tree species, two sources of phenological information from the Copenhagen area (Denmark) were analysed, i.e. pollen counts of the genus Betula and observed first bloom dates of Prunus avium. The Winter NAO explained 29 and 37% of the variation of monthly mean temperature for February and March, respectively. The influence of temperature on flowering time was up to 56% to 60% for the February April mean. A direct correlation of Winter NAO-index and flowering time also revealed a clear relation but the time of influence was earlier (December to February). This was shown to be the likely result of a combination of direct and time-lagged effects of the NAO on air and sea surface temperature. The NAO signal is apparently stored in the North Sea and then influences temperature east up to the Baltic States. It is shown that Denmark is right in the centre of direct and time-lagged effects of the NAO. This offers the possibility of using the NAO-index for predicting flowering time of Prunus avium. The beginning of pollen flow appears to be influenced too much by short-term perturbations of the climate system decreasing the value of the NAO-index for prediction. However, it indicates a close relationship between natural climate variability, measured by the NAO index, and flowering time of tree species for Denmark.

  12. Universal Cosmic Absolute and Modern Science

    NASA Astrophysics Data System (ADS)

    Kostro, Ludwik

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

  13. Prediction of mean skin temperature for use as a heat strain scale by introducing an equation for sweating efficiency

    NASA Astrophysics Data System (ADS)

    Kubota, H.; Kuwabara, K.; Hamada, Y.

    2014-09-01

    The present paper made the heat balance equation (HBE) for nude or minimally clad subjects a linear function of mean skin temperature ( t sk) by applying new equations for sweating efficiency ( η sw) and thermoregulatory sweat rate ( S wR). As the solution of the HBE, the equation predicting t sk was derived and used for a heat strain scale of subjects. The η sw was proportional to the reciprocal of S w/ E max ( S w, sweat rate; E max maximum evaporative capacity) and the S wR was proportional to t sk with a parameter of the sweating capacity of the subject. The errors of predicted t sk from observations due to the approximation of η sw were examined based on experimental data conducted on eight young male subjects. The value of errors of t sk was -0.10 ± 0.42 °C (mean ± sample standard deviation (SSD)). We aim to apply the predicted t sk of a subject at a level of sweating capacity as a heat strain scale of a function of four environmental factors (dry- and wet-bulb temperatures, radiation, and air velocity) and three human factors (metabolic rate, sweating capacity, and clothing (≤0.2clo)).

  14. Effects of the 7-8-year cycle in daily mean air temperature as a cross-scale information transfer

    NASA Astrophysics Data System (ADS)

    Jajcay, Nikola; Hlinka, Jaroslav; Paluš, Milan

    2015-04-01

    Using a novel nonlinear time-series analysis method, an information transfer from larger to smaller scales of the air temperature variability has been observed in daily mean surface air temperature (SAT) data from European stations as the influence of the phase of slow oscillatory phenomena with periods around 6-11 years on amplitudes of the variability characterized by smaller temporal scales from a few months to 4-5 years [1]. The strongest effect is exerted by an oscillatory mode with the period close to 8 years and its influence can be seen in 1-2 °C differences of the conditional SAT means taken conditionally on the phase of the 8-year cycle. The size of this effect, however, changes in space and time. The changes in time are studied using sliding window technique, showing that the effect evolves in time, and during the last decades the effect is stronger and significant. Sliding window technique was used along with seasonal division of the data, and it has been found that the cycle is most pronounced in the winter season. Different types of surrogate data are applied in order to establish statistical significance and distinguish the effect of the 7-8-yr cycle from climate variability on shorter time scales. [1] M. Palus, Phys. Rev. Lett. 112 078702 (2014) This study is supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Program KONTAKT II, Project No. LH14001.

  15. Modeling of mean radiant temperature based on comparison of airborne remote sensing data with surface measured data

    NASA Astrophysics Data System (ADS)

    Chen, Yu-Cheng; Chen, Chih-Yu; Matzarakis, Andreas; Liu, Jin-King; Lin, Tzu-Ping

    2016-06-01

    Assessment of outdoor thermal comfort is becoming increasingly important due to the urban heat island effect, which strongly affects the urban thermal environment. The mean radiant temperature (Tmrt) quantifies the effect of the radiation environment on humans, but it can only be estimated based on influencing parameters and factors. Knowledge of Tmrt is important for quantifying the heat load on human beings, especially during heat waves. This study estimates Tmrt using several methods, which are based on climatic data from a traditional weather station, microscale ground surface measurements, land surface temperature (LST) and light detection and ranging (LIDAR) data measured using airborne devices. Analytical results reveal that the best means of estimating Tmrt combines information about LST and surface elevation information with meteorological data from the closest weather station. The application in this method can eliminate the inconvenience of executing a wide range ground surface measurement, the insufficient resolution of satellite data and the incomplete data of current urban built environments. This method can be used to map a whole city to identify hot spots, and can be contributed to understanding human biometeorological conditions quickly and accurately.

  16. A SOLAR SPECTROSCOPIC ABSOLUTE ABUNDANCE OF ARGON FROM RESIK

    SciTech Connect

    Sylwester, J.; Sylwester, B.; Phillips, K. J. H.; Kuznetsov, V. D. E-mail: kjhp@mssl.ucl.ac.u

    2010-09-10

    Observations of He-like and H-like Ar (Ar XVII and Ar XVIII) lines at 3.949 A and 3.733 A, respectively, with the RESIK X-ray spectrometer on the CORONAS-F spacecraft, together with temperatures and emission measures from the two channels of GOES, have been analyzed to obtain the abundance of Ar in flare plasmas in the solar corona. The line fluxes per unit emission measure show a temperature dependence like that predicted from theory and lead to spectroscopically determined values for the absolute Ar abundance, A(Ar) = 6.44 {+-} 0.07 (Ar XVII) and 6.49 {+-} 0.16 (Ar XVIII), which are in agreement to within uncertainties. The weighted mean is 6.45 {+-} 0.06, which is between two recent compilations of the solar Ar abundance and suggests that the photospheric and coronal abundances of Ar are very similar.

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

    ERIC Educational Resources Information Center

    Amrani, D.

    2007-01-01

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

  18. Regional Contrasts of the Warming Rate over Land Significantly Depend on the Calculation Methods of Mean Air Temperature.

    PubMed

    Wang, Kaicun; Zhou, Chunlüe

    2015-07-22

    Global analyses of surface mean air temperature (T(m)) are key datasets for climate change studies and provide fundamental evidences for global warming. However, the causes of regional contrasts in the warming rate revealed by such datasets, i.e., enhanced warming rates over the northern high latitudes and the "warming hole" over the central U.S., are still under debate. Here we show these regional contrasts depend on the calculation methods of T(m). Existing global analyses calculate T(m) from daily minimum and maximum temperatures (T2). We found that T2 has a significant standard deviation error of 0.23 °C/decade in depicting the regional warming rate from 2000 to 2013 but can be reduced by two-thirds using T(m) calculated from observations at four specific times (T4), which samples diurnal cycle of land surface air temperature more often. From 1973 to 1997, compared with T4, T2 significantly underestimated the warming rate over the central U.S. and overestimated the warming rate over the northern high latitudes. The ratio of the warming rate over China to that over the U.S. reduces from 2.3 by T2 to 1.4 by T4. This study shows that the studies of regional warming can be substantially improved by T4 instead of T2.

  19. Global and Regional Variations in Mean Temperature and Warm Extremes in Large-Member Historical AGCM Simulation

    NASA Astrophysics Data System (ADS)

    Kamae, Y.; Shiogama, H.; Imada, Y.; Mori, M.; Arakawa, O.; Mizuta, R.; Yoshida, K.; Ishii, M.; Watanabe, M.; Kimoto, M.; Ueda, H.

    2015-12-01

    Frequency of heat extremes during the summer season has increased continuously since the late 20th century despite the global warming hiatus. In previous studies, anthropogenic influences, natural variation in sea surface temperature (SST), and internal atmospheric variabilities are suggested to be factors contributing to the increase in the frequency of warm extremes. Here 100-member ensemble historical simulations were performed (called "database for Probabilistic Description of Future climate"; d4PDF) to examine physical mechanisms responsible for the increasing hot summers and attribute to the anthropogenic influences or natural climate variability. 60km resolution MRI-AGCM ensemble simulations can reproduce historical variations in the mean temperature and warm extremes. Natural SST variability in the Pacific and Atlantic Oceans contribute to the decadal variation in the frequency of hot summers in the Northern Hemisphere middle latitude. For example, the surface temperature over western North America, including California, is largely influenced by anomalous atmospheric circulation pattern associated with Pacific SST variability. Future projections based on anomalous SST patterns derived from coupled climate model simulations will also be introduced.

  20. Temperature dependence of three-body hydrophobic interactions: potential of mean force, enthalpy, entropy, heat capacity, and nonadditivity.

    PubMed

    Moghaddam, Maria Sabaye; Shimizu, Seishi; Chan, Hue Sun

    2005-01-12

    Temperature-dependent three-body hydrophobic interactions are investigated by extensive constant-pressure simulations of methane-like nonpolar solutes in TIP4P model water at six temperatures. A multiple-body hydrophobic interaction is considered to be (i) additive, (ii) cooperative, or (iii) anti-cooperative if its potential of mean force (PMF) is (i) equal to, (ii) smaller than, or (iii) larger than the corresponding pairwise sum of two-methane PMFs. We found that three-methane hydrophobic interactions at the desolvation barrier are anti-cooperative at low to intermediate T, and vary from essentially additive to slightly cooperative at high T. Interactions at the contact minimum are slightly anti-cooperative over a wider temperature range. Enthalpy, entropy, and heat capacity are estimated from the computed PMFs. Contrary to the common expectation that burial of solvent-accessible nonpolar surface area always leads to a decrease in heat capacity, the present results show that the change in heat capacity upon three-methane association is significantly positive at the desolvation barrier and slightly positive at the contact minimum. This suggests that the heat capacity signature of a hydrophobic polymer need not vary uniformly nor monotonically with conformational compactness. Ramifications for protein folding are discussed.

  1. Response of the annual and zonal mean winds and temperatures to variations in the heat and momentum sources

    NASA Technical Reports Server (NTRS)

    Schneider, E. K.

    1984-01-01

    Comparisons are made among solutions to zonal-mean equations obtained with parameterized friction and radiative cooling and those forced from specified heat and momentum sources. Budget equations are defined for zonally averaged steady state responses in a thin spherically rotating atmosphere. The heat sources and sinks and mean meridional circulation that maintain observed annual and zonal mean temperatures are identified with a diagnostic calculation. Estimates are made of the surface sensible heating, atmospheric latent heating and vertical flux eddy divergences. The heat and moisture sources and sinks are varied to obtain the steady state responses. The Hadley circulation is fairly insensitive to changes in the strength of the eddy momentum flux when sufficient internal friction is present. Varying the width of the total precipitation of the intertropical convergence zone with fixed eddy fluxes and extratropical heat sources yields conditions similar to El Nino. Finally, a minimum speed is found for the jet stream after varying the horizontal eddy momentum fixing latent and eddy heat sources.

  2. Estimating Absolute Site Effects

    SciTech Connect

    Malagnini, L; Mayeda, K M; Akinci, A; Bragato, P L

    2004-07-15

    The authors use previously determined direct-wave attenuation functions as well as stable, coda-derived source excitation spectra to isolate the absolute S-wave site effect for the horizontal and vertical components of weak ground motion. They used selected stations in the seismic network of the eastern Alps, and find the following: (1) all ''hard rock'' sites exhibited deamplification phenomena due to absorption at frequencies ranging between 0.5 and 12 Hz (the available bandwidth), on both the horizontal and vertical components; (2) ''hard rock'' site transfer functions showed large variability at high-frequency; (3) vertical-motion site transfer functions show strong frequency-dependence, and (4) H/V spectral ratios do not reproduce the characteristics of the true horizontal site transfer functions; (5) traditional, relative site terms obtained by using reference ''rock sites'' can be misleading in inferring the behaviors of true site transfer functions, since most rock sites have non-flat responses due to shallow heterogeneities resulting from varying degrees of weathering. They also use their stable source spectra to estimate total radiated seismic energy and compare against previous results. they find that the earthquakes in this region exhibit non-constant dynamic stress drop scaling which gives further support for a fundamental difference in rupture dynamics between small and large earthquakes. To correct the vertical and horizontal S-wave spectra for attenuation, they used detailed regional attenuation functions derived by Malagnini et al. (2002) who determined frequency-dependent geometrical spreading and Q for the region. These corrections account for the gross path effects (i.e., all distance-dependent effects), although the source and site effects are still present in the distance-corrected spectra. The main goal of this study is to isolate the absolute site effect (as a function of frequency) by removing the source spectrum (moment-rate spectrum) from

  3. Mean ocean temperature change over the last glacial transition based on atmospheric changes in heavy noble mixing ratios

    NASA Astrophysics Data System (ADS)

    Bereiter, Bernhard; Severinghaus, Jeff; Shackleton, Sarah; Baggenstos, Daniel; Kawamura, Kenji

    2016-04-01

    On paleo-climatic timescales heavy noble gases (Krypton and Xenon) are passively cycled through the atmosphere-ocean system without seeing any significant sink or source. Since the solubility in water of each gas species is characterized by a specific temperature dependency, mixing ratios in the atmosphere change with changing ocean temperatures. In this study, we use this fact to reconstruct mean global ocean temperatures (MOT) over the course of the last glacial transition based on measurements of trapped air in the WAIS Divide ice core. We analyzed 70 ice samples with a recently developed method which determines the isotopic ratios of N2, Ar, Kr (and in some cases also of Xe, though with less precision) and the elemental ratios of Kr/N2, Xe/N2 and Xe/Kr. We use the isotope ratios to correct the elemental ratios for gravitational enrichment in the firn column. The corrected elemental ratios are then used in a simple box model to reconstruct MOT. The three elemental ratio pairs are first interpreted as independent measures of MOT and then combined to a single "best-estimate" MOT record with an average uncertainty of 0.27°C. We find a clear link to Antarctic temperatures and a LGM-Holocene change in MOT of 2.4°C. This value is in good agreement with results from marine sediment cores (which, however, have an uncertainty of 1°C). Our record provides an unprecedented constrain on ocean heat uptake over the last glacial transition and therefore gives new insights in the mechanisms underlying long term ocean heat fluxes. To our knowledge, this is the first time that MOT has been reconstructed in such great detail.

  4. Pairwise comparisons to reconstruct mean temperature in the Arctic Atlantic Region over the last 2,000 years

    NASA Astrophysics Data System (ADS)

    Hanhijärvi, Sami; Tingley, Martin P.; Korhola, Atte

    2013-10-01

    Existing multi-proxy climate reconstruction methods assume the suitably transformed proxy time series are linearly related to the target climate variable, which is likely a simplifying assumption for many proxy records. Furthermore, with a single exception, these methods face problems with varying temporal resolutions of the proxy data. Here we introduce a new reconstruction method that uses the ordering of all pairs of proxy observations within each record to arrive at a consensus time series that best agrees with all proxy records. The resulting unitless composite time series is subsequently calibrated to the instrumental record to provide an estimate of past climate. By considering only pairwise comparisons, this method, which we call PaiCo, facilitates the inclusion of records with differing temporal resolutions, and relaxes the assumption of linearity to the more general assumption of a monotonically increasing relationship between each proxy series and the target climate variable. We apply PaiCo to a newly assembled collection of high-quality proxy data to reconstruct the mean temperature of the Northernmost Atlantic region, which we call Arctic Atlantic, over the last 2,000 years. The Arctic Atlantic is a dynamically important region known to feature substantial temperature variability over recent millennia, and PaiCo allows for a more thorough investigation of the Arctic Atlantic regional climate as we include a diverse array of terrestrial and marine proxies with annual to multidecadal temporal resolutions. Comparisons of the PaiCo reconstruction to recent reconstructions covering larger areas indicate greater climatic variability in the Arctic Atlantic than for the Arctic as a whole. The Arctic Atlantic reconstruction features temperatures during the Roman Warm Period and Medieval Climate Anomaly that are comparable or even warmer than those of the twentieth century, and coldest temperatures in the middle of the nineteenth century, just prior to the onset

  5. High Spatial Resolution Forecasting of Long-Term Monthly Precipitation and Mean Temperature Trends in Data Scarce Regions

    NASA Astrophysics Data System (ADS)

    Mosier, T. M.; Hill, D. F.; Sharp, K. V.

    2013-12-01

    High spatial resolution time-series data are critical for many hydrological and earth science studies. Multiple groups have developed historical and forecast datasets of high-resolution monthly time-series for regions of the world such as the United States (e.g. PRISM for hindcast data and MACA for long-term forecasts); however, analogous datasets have not been available for most data scarce regions. The current work fills this data need by producing and freely distributing hindcast and forecast time-series datasets of monthly precipitation and mean temperature for all global land surfaces, gridded at a 30 arc-second resolution. The hindcast data are constructed through a Delta downscaling method, using as inputs 0.5 degree monthly time-series and 30 arc-second climatology global weather datasets developed by Willmott & Matsuura and WorldClim, respectively. The forecast data are formulated using a similar downscaling method, but with an additional step to remove bias from the climate variable's probability distribution over each region of interest. The downscaling package is designed to be compatible with a number of general circulation models (GCM) (e.g. with GCMs developed for the IPCC AR4 report and CMIP5), and is presently implemented using time-series data from the NCAR CESM1 model in conjunction with 30 arc-second future decadal climatologies distributed by the Consultative Group on International Agricultural Research. The resulting downscaled datasets are 30 arc-second time-series forecasts of monthly precipitation and mean temperature available for all global land areas. As an example of these data, historical and forecast 30 arc-second monthly time-series from 1950 through 2070 are created and analyzed for the region encompassing Pakistan. For this case study, forecast datasets corresponding to the future representative concentration pathways 45 and 85 scenarios developed by the IPCC are presented and compared. This exercise highlights a range of potential

  6. Absolute cavity pyrgeometer

    DOEpatents

    Reda, Ibrahim

    2013-10-29

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

  7. The prediction of sea-surface temperature variations by means of an advective mixed-layer ocean model

    NASA Technical Reports Server (NTRS)

    Atlas, R. M.

    1976-01-01

    An advective mixed layer ocean model was developed by eliminating the assumption of horizontal homogeneity in an already existing mixed layer model, and then superimposing a mean and anomalous wind driven current field. This model is based on the principle of conservation of heat and mechanical energy and utilizes a box grid for the advective part of the calculation. Three phases of experiments were conducted: evaluation of the model's ability to account for climatological sea surface temperature (SST) variations in the cooling and heating seasons, sensitivity tests in which the effect of hypothetical anomalous winds was evaluated, and a thirty-day synoptic calculation using the model. For the case studied, the accuracy of the predictions was improved by the inclusion of advection, although nonadvective effects appear to have dominated.

  8. Eosinophil count - absolute

    MedlinePlus

    ... or 0.50 x 10^9/L. Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results. The example above shows the common measurements for results of these tests. Some laboratories use ...

  9. Boundary layer fluctuations and their effects on mean and variance temperature profiles in turbulent Rayleigh-Bénard convection

    NASA Astrophysics Data System (ADS)

    Wang, Yin; He, Xiaozhou; Tong, Penger

    2016-11-01

    We report simultaneous measurements of the mean temperature profile θ (z) and temperature variance profile η (z) near the lower conducting plate of a specially designed quasi-two-dimensional cell for turbulent Rayleigh-Bénard convection. The measured θ (z) is found to have a universal scaling form θ (z / δ) with varying thermal boundary layer (BL) thickness δ, and its functional form agrees well with the recently derived BL equation by Shishkina et al. The measured η (z) , on the other hand, is found to have a scaling form η (z / δ) only in the near-wall region with z / δ < 2 . Based on the experimental findings, we derive a new BL equation for η (z / δ) , which is in good agreement with the experimental results. The new BL equations thus provide a common framework for understanding the effect of BL fluctuations. This work was supported by the Research Grants Council of Hong Kong SAR and by the China Thousand Young Talents Program.

  10. SOLWEIG 1.0--modelling spatial variations of 3D radiant fluxes and mean radiant temperature in complex urban settings.

    PubMed

    Lindberg, Fredrik; Holmer, Björn; Thorsson, Sofia

    2008-09-01

    The mean radiant temperature, T(mrt), which sums up all shortwave and longwave radiation fluxes (both direct and reflected) to which the human body is exposed is one of the key meteorological parameters governing human energy balance and the thermal comfort of man. In this paper, a new radiation model (SOLWEIG 1.0), which simulates spatial variations of 3D radiation fluxes and T(mrt) in complex urban settings, is presented. The T(mrt) is derived by modelling shortwave and longwave radiation fluxes in six directions (upward, downward and from the four cardinal points) and angular factors. The model requires a limited number of inputs, such as direct, diffuse and global shortwave radiation, air temperature, relative humidity, urban geometry and geographical information (latitude, longitude and elevation). The model was evaluated using 7 days of integral radiation measurements at two sites with different building geometries--a large square and a small courtyard in Göteborg, Sweden (57 degrees N)--across different seasons and in various weather conditions. The evaluation reveals good agreement between modelled and measured values of T(mrt), with an overall good correspondence of R (2) = 0.94, (p < 0.01, RMSE = 4.8 K). SOLWEIG 1.0 is still under development. Future work will incorporate a vegetation scheme, as well as an improvement of the estimation of fluxes from the four cardinal points.

  11. The effect of gravity waves on the global mean temperature and composition structure of the upper atmosphere

    NASA Technical Reports Server (NTRS)

    Gavrilov, Nikolai M.; Roble, Raymond G.

    1994-01-01

    Formulas are presented that parameterize the heating rate and coefficient of turbulent heat conduction produced by saturated internal gravity waves (IGW) in the upper atmosphere. Estimates of these values are made using observational data. The parameterization of IGW influences are introduced into a one-dimensional model of global mean thermal and composition balances of the upper atmosphere. Computations are performed for different values of IGW energy fluxes entering into the upper atmosphere from below. It is shown that realistic vertical profiles of the global mean temperature can be obtained using different values of IGW energy flux into the upper atmosphere. Increasing the IGW intensity leads not only to an increase of the heating rate due to wave enery dissipation, but also to an increase of the heating rate due to wave energy dissipation, but also to an increase in the coefficient of turbulent heat conduction and cooling rate produced by turbulence generated by the wave. So, near an altitude of 100 km the main part of solar heating is compensated by infrared cooling on one hand, and the main part of wave dissipation heating is compensated by turbulent cooling on the other hand. These quasi-balances generally hold for different values of IGW intensity.

  12. Comparison of two homogenized datasets of daily maximum/mean/minimum temperature in China during 1960-2013

    NASA Astrophysics Data System (ADS)

    Li, Zhen; Cao, Lijuan; Zhu, Yani; Yan, Zhongwei

    2016-02-01

    Two homogenized datasets of daily maximum temperature (Tmax), mean temperature (Tm), and minimum temperature (Tmin) series in China have recently been developed. One is CHTM3.0, based on the Multiple Analysis of Series for Homogenization (MASH) method, and includes 753 stations for the period 1960-2013. The other is CHHTD1.0, based on the Relative Homogenization test (RHtest), and includes 2419 stations over the period 1951-2011. The daily Tmax/Tm/Tmin series at 751 stations, which are in both datasets, are chosen and compared against the raw dataset, with regard to the number of breakpoints, long-term climate trends, and their geographical patterns. The results indicate that some robust break points associated with relocations can be detected, the inhomogeneities are removed by both the MASH and RHtest method, and the data quality is improved in both homogenized datasets. However, the differences between CHTM3.0 and CHHTD1.0 are notable. By and large, in CHHTD1.0, the break points detected are fewer, but the adjustments for inhomogeneities and the resultant changes of linear trend estimates are larger. In contrast, CHTM3.0 provides more reasonable geographical patterns of long-term climate trends over the region. The reasons for the differences between the datasets include: (1) different algorithms for creating reference series for adjusting the candidate series—more neighboring stations used in MASH and hence larger-scale regional signals retained; (2) different algorithms for calculating the adjustments—larger adjustments in RHtest in general, partly due to the individual local reference information used; and (3) different rules for judging inhomogeneity—all detected break points are adjusted in CHTM3.0, based on MASH, while a number of break points detected via RHtest but without supporting metadata are overlooked in CHHTD1.0. The present results suggest that CHTM3.0 is more suitable for analyses of large-scale climate change in China, while CHHTD1

  13. Increased carbon flux with rising mean annual temperature does not alter ecosystem carbon storage in a tropical montane wet forest

    NASA Astrophysics Data System (ADS)

    Selmants, P.; Litton, C. M.; Giardina, C. P.

    2013-12-01

    Ecological theory and existing studies agree that climate warming will increase carbon fluxes between terrestrial ecosystems and the atmosphere in the absence of water and nutrient limitations. However, it remains unclear how increased carbon input to and loss from terrestrial ecosystems will affect overall ecosystem carbon storage, which has important implications for potential feedbacks to climate change. Here we use a well-constrained model ecological gradient to quantify how increased mean annual temperature (MAT) affects carbon fluxes and ecosystem carbon storage in above- and belowground live biomass and detritus across nine permanent plots representing a 5.2ο C MAT gradient in tropical montane wet forests on the Island of Hawaii. Aboveground net primary productivity increased by 1 Mg ha-1 y-1 and the residence time of carbon in the forest floor declined by ~3 months for each 1ο C rise in MAT across the gradient, indicating a substantial increase in both carbon input and output with rising MAT. Despite these large increases in carbon flux, ecosystem carbon storage showed minimal sensitivity to MAT. Live biomass carbon did not vary predictably as a function of temperature. Detrital carbon declined by ~14 Mg ha-1 for each 1ο C rise in temperature, but this decline was driven entirely by coarse woody debris and litter, which together make up < 10% on average of total ecosystem C across the MAT gradient. The largest detrital pool, soil carbon, did not vary with MAT, averaging 48% of total ecosystem carbon across the gradient. Overall, total ecosystem carbon storage did not vary with MAT, averaging ~550 Mg ha-1 across the gradient. In addition, the distribution of ecosystem carbon in live biomass vs. detritus remained relatively constant at ~44% and ~56%, respectively. Because our MAT gradient does not vary with respect to factors other than temperature (i.e., dominant vegetation, substrate type and age, soil water balance, and disturbance history), these

  14. Determining Absolute Zero Using a Tuning Fork

    NASA Astrophysics Data System (ADS)

    Goldader, Jeffrey D.

    2008-04-01

    The Celsius and Kelvin temperature scales, we tell our students, are related. We explain that a change in temperature of 1°C corresponds to a change of 1 Kelvin and that atoms and molecules have zero kinetic energy at zero Kelvin, -273°C. In this paper, we will show how students can derive the relationship between the Celsius and Kelvin temperature scales using a simple, well-known physics experiment. By making multiple measurements of the speed of sound at different temperatures, using the classic physics experiment of determining the speed of sound with a tuning fork and variable-length tube, they can determine the temperature at which the speed of sound is zero—absolute zero.

  15. Mars atmosphere dynamics: seasonal evolution of mean meridional temperature cross section and zonal wind derived from PFS-MEX.

    NASA Astrophysics Data System (ADS)

    D'Amore, M.; Grassi, D.; Formisano, V.

    2008-09-01

    A big amount of data acquired by the Planetary Fourier Spectrometer (PFS) on board of Mars Express mission (MEX) has been analyzed, resulting in a higher level data, namely calculated atmospheric temperatures field, thanks to the operational range of PFS long wavelength channel falling in the Thermal Infrared region. Singles temperature profile has been obtained by the BDM algorithm, developed in IFSI and described in great detail in [1]. Starting from these data, thanks also to spacecraft polar orbit, we are able to derive mean meridional cross section of thermal structure, using the geostrophic or higher-order approximations [3], and to compute the related zonal wind in the range from 5 to about 50 km. Also the annual evolution atmospheric temperature and zonal winds can be seen from the analysis, thanks to the large time spanned by data set, namely solar longitude 330°-360° for the first observation year, until 210° of solar longitude from the second year, or, in other words, from the end of the north hemisphere winter to the middle autumn, highlighting the residual Hadley circulation. As from previous results performed on Thermal Emission Spectrometer (TES), presence of asymmetric Hadley circulation is clearly shown: during the solstice there should be only one cell (Fig.1) starting from a near equatorial region ascending branch and ending in a polar descending branch in northern hemisphere at the beginning of the northern winter and in southern hemisphere at the end of the northern summer [2]. An attempt to compare our results with model and other instruments' result is made, showing both the agreement whit the European Mars Climate Database and with zonal wind derived from TES, on board the Mars Global Surveyor. The latter dataset present significative difference due to different observational parameters, first of all a different orbit, even if there is a good agreement between results from the two instruments. References [1] Grassi D. , et al (2005) PSS

  16. Method and apparatus for two-dimensional absolute optical encoding

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas B. (Inventor)

    2004-01-01

    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.

  17. The role of external forcing and internal variability in regulating global mean surface temperatures on decadal timescales

    NASA Astrophysics Data System (ADS)

    Dong, Lu; McPhaden, Michael J.

    2017-03-01

    Global mean surface temperature (GMST) shows considerable decadal variations superimposed on a pronounced warming trend, with rapid warming during 1920–1945 and 1977–2000 and warming hiatuses during 1946–1976 and 2001–2013. The prevailing view is that internally generated variations associated with the Interdecadal Pacific Oscillation (IPO) dominate decadal variations in GMST, while external forcing from greenhouse gases and anthropogenic aerosols dominate the long-term trend in GMST over the last hundred years. Here we show evidence from observations and climate models that external forcing largely governs decadal GMST variations in the historical record with internally generated variations playing a secondary role, except during those periods of IPO extremes. In particular, the warming hiatus during 1946–1976 started from a negative IPO but was later dominated by the eruption of Mount Agung in 1963, while the subsequent accelerated warming during 1977–2000 was due primarily to increased greenhouse gas forcing. The most recent warming hiatus apparent in observations occurred largely through cooling from a negative IPO extreme that overwhelmed the warming from external forcing. An important implication of this work is that when the phase of the IPO turns positive, as it did in 2014, the combination of external forcing and internal variability should lead to accelerated global warming. This accelerated warming appears to be underway, with record high GMST in 2014, 2015, and 2016.

  18. Small-pore, big opportunity: searching for novel applications of small-pore zeolites by means of pressure and temperature

    NASA Astrophysics Data System (ADS)

    Im, J.; Lee, Y.

    2013-12-01

    Pressure-induced structural and chemical changes observed in small-pore zeolite natrolites are especially encouraging in terms of finding appropriate applications as they occur in the industrially-achievable low-pressure regime, i.e., as low as a few kilobars. After identifying the systematics of structural and chemical behaviors of natrolites in relation to the composition of pressure media, we have developed a procedure to exchange and sequestrate both Cs cation and I anion under intermediate pressure and temperature conditions. This result points towards the possibility of designing novel storage means for important radionuclides. Another avenue to utilize the unique pressure-induced chemistry of small-pore zeolite natrolite is to trap nominally non-adsorbable gas molecules via auxetic expansion under pressure. We have recently succeeded in pressure-induced insertion of Xe into silver-natrolite. Intriguingly, Xe adsorption occurs concomitant with charge disproportionation of silver cations to form silver nano-blobs on the surface of natrolite crystals. We will also present here various usages of laboratory-based high-pressure devices and characterization tools, which play important roles to confirm the synchrotron-based high-pressure experiments involving synthesis of new materials.

  19. From Hubble's NGSL to Absolute Fluxes

    NASA Technical Reports Server (NTRS)

    Heap, Sara R.; Lindler, Don

    2012-01-01

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

  20. Quantifying the temperature-independent effect of stratospheric aerosol geoengineering on global-mean precipitation in a multi-model ensemble

    NASA Astrophysics Data System (ADS)

    Ferraro, Angus J.; Griffiths, Hannah G.

    2016-03-01

    The reduction in global-mean precipitation when stratospheric aerosol geoengineering is used to counterbalance global warming from increasing carbon dioxide (CO2) concentrations has been mainly attributed to the temperature-independent effect of CO2 on atmospheric radiative cooling. We demonstrate here that stratospheric sulphate aerosol itself also acts to reduce global-mean precipitation independent of its effects on temperature. The temperature-independent effect of stratospheric aerosol geoenginering on global-mean precipitation is calculated by removing temperature-dependent effects from climate model simulations of the Geoengineering Model Intercomparison Project (GeoMIP). When sulphate aerosol is injected into the stratosphere at a rate of 5 Tg SO2 per year the aerosol reduces global-mean precipitation by approximately 0.2 %, though multiple ensemble members are required to separate this effect from internal variability. For comparison, the precipitation reduction from the temperature-independent effect of increasing CO2 concentrations under the RCP4.5 scenario of the future is approximately 0.5 %. The temperature-independent effect of stratospheric sulphate aerosol arises from the aerosol’s effect on tropospheric radiative cooling. Radiative transfer calculations show this is mainly due to increasing downward emission of infrared radiation by the aerosol, but there is also a contribution from the stratospheric warming the aerosol causes. Our results suggest climate model simulations of solar dimming can capture the main features of the global-mean precipitation response to stratospheric aerosol geoengineering.

  1. Molecular composition of soil organic matter with land-use change along a bi-continental mean annual temperature gradient.

    PubMed

    Pisani, Oliva; Haddix, Michelle L; Conant, Richard T; Paul, Eldor A; Simpson, Myrna J

    2016-12-15

    Soil organic matter (SOM) is critical for maintaining soil fertility and long-term agricultural sustainability. The molecular composition of SOM is likely altered due to global climate and land-use change; but rarely are these two aspects studied in tandem. Here we used molecular-level techniques to examine SOM composition along a bi-continental (from North to South America) mean annual temperature (MAT) gradient from seven native grassland/forest and cultivated/pasture sites. Biomarker methods included solvent extraction, base hydrolysis and cupric (II) oxide oxidation for the analysis of free lipids of plant and microbial origin, ester-bound lipids from cutin and suberin, and lignin-derived phenols, respectively. Solid-state (13)C nuclear magnetic resonance (NMR) was used to examine the overall composition of SOM. Soil cultivation was found to increase the amount of microbial-derived compounds at warmer temperatures (up to 17% increase). The cultivated soils were characterized by much lower contributions of plant-derived SOM components compared to the native soils (up to 64% lower at the coldest site). In addition, cultivation caused an increase in lignin and cutin degradation (up to 68 and 15% increase, respectively), and an increase in the amount of suberin-derived inputs (up to 54% increase). Clear differences in the molecular composition of SOM due to soil cultivation were observed in soils of varying mineral composition and were attributed to disturbance, different vegetation inputs, soil aggregate destruction and MAT. A high organic allophanic tropical soil was characterized by its protection of carbohydrates and nitrogen-containing compounds. The conversion of native to cultivated land shows significant shifts in the degradation stage of SOM. In particular, cutin-derived compounds which are believed to be part of the stable SOM pool may undergo enhanced degradation with long-term cultivation and disruption of soil aggregates. On a per year basis, the total

  2. Regionalization of Europe based on a K-Means Cluster Analysis of the climate change of temperatures and precipitation

    NASA Astrophysics Data System (ADS)

    Carvalho, M. J.; Melo-Gonçalves, P.; Teixeira, J. C.; Rocha, A.

    2016-08-01

    In order to study climate change on a regional scale using Earth System Models, it is useful to partition the spatial domain into regions according to their climate changes. The aim of this work is to divide the European domain into regions of similar projected climate changes using a simulation of daily total precipitation, minimum and maximum temperatures for the recent-past (1986-2005) and long-term future (2081-2100) provided by the Coupled Model Intercomparison Project (CMIP5). The difference between the long-term future and recent-past daily climatologies of these three variables is determined. Aiming to objectively identify the grid points with coherent climate changes, a K-Mean Cluster Analysis is applied to these differences. This method is performed for each variable independently (univariate version) and for the aggregation of the three variables (multivariate version). A mathematical approach to determine the optimal number of clusters is pursued. However, due to the method characteristics, a sensitivity test to the number of clusters is performed by analysing the consistency of the results. This is a novel method, allowing for the determination of regions based on the climate change of multiple variables. Results from the univariate application of this method are in accordance with results found in the literature, showing overall similar regions of changes. The regions obtained for the multivariate version are mainly defined by latitude over European land, with some features of land-sea interaction. Furthermore, all regions have statistically different distributions of at least one of the variables, providing confidence to the regions obtained.

  3. May–June Maximum Temperature Reconstruction from Mean Earlywood Density in North Central China and Its Linkages to the Summer Monsoon Activities

    PubMed Central

    Chen, Feng; Yuan, Yujiang

    2014-01-01

    Cores of Pinus tabulaformis from Tianshui were subjected to densitometric analysis to obtain mean earlywood density data. Climate response analysis indicates that May–June maximum temperature is the main factor limiting the mean earlywood density (EWD) of Chinese pine trees in the Shimen Mountains. Based on the EWD chronology, we have reconstructed May–June maximum temperature 1666 to 2008 for Tianshui, north central China. The reconstruction explains 40.1% of the actual temperature variance during the common period 1953–2008. The temperature reconstruction is representative of temperature conditions over a large area to the southeast and northwest of the sampling site. Preliminary analysis of links between large-scale climatic variation and the temperature reconstruction shows that there is a relationship between extremes in spring temperature and anomalous atmospheric circulation in the region. It is thus revealed that the mean earlywood density chronology of Pinus tabulaformis has enough potential to reconstruct the temperature variability further into the past. PMID:25207554

  4. Lidar observations of seasonal variation of diurnal mean temperature in the mesopause region over Fort Collins, Colorado (41°N, 105°W)

    NASA Astrophysics Data System (ADS)

    Chen, Songsheng; Hu, Zhilin; White, M. A.; Chen, H.; Krueger, D. A.; She, C. Y.

    2000-05-01

    Two campaigns from February 1997 to January 1999 have resulted in 18 sets of continuous temperature measurements in the mesopause region over Fort Collins, Colorado (41°N, 105°W), each covering a complete diurnal cycle, reasonably well distributed throughout the year. It is shown that the winter-summer transitions, based on diurnal means, are abrupt and clear, further strengthening the concept of two-level mesopause, and demonstrate the robustness of this picture. Similar to data taken at Urbana, Illinois, our data at Fort Collins also demonstrate the need to observe over a complete diurnal cycle to deduce the uncontaminated mean temperature structure and seasonal variations in the mesopause region. The difference between annual diurnal, nighttime, and daytime means may be ascribed to a temperature wave propagating with a downward phase speed of ˜0.8 km/h. Our data show that the nighttime annual mean is colder than the diurnal annual mean by no more than 2 K below 88 km and warmer by no more than 3 K above 88 km where the three means are nearly the same. As in the Urbana data, we also observed the altitude of a secondary temperature minimum in the summer to be ˜96 km, which without strong dynamical cooling in the summer would have been the summer mesopause altitude.

  5. Absolute classification with unsupervised clustering

    NASA Technical Reports Server (NTRS)

    Jeon, Byeungwoo; Landgrebe, D. A.

    1992-01-01

    An absolute classification algorithm is proposed in which the class definition through training samples or otherwise is required only for a particular class of interest. The absolute classification is considered as a problem of unsupervised clustering when one cluster is known initially. The definitions and statistics of the other classes are automatically developed through the weighted unsupervised clustering procedure, which is developed to keep the cluster corresponding to the class of interest from losing its identity as the class of interest. Once all the classes are developed, a conventional relative classifier such as the maximum-likelihood classifier is used in the classification.

  6. Preliminary results of a determination of temperatures of flames by means of K-band microwave attenuation

    NASA Technical Reports Server (NTRS)

    Rudlin, Leonard

    1951-01-01

    The temperature effects on the attenuation of K-band microwaves, at a frequency of 26,500 plus or minus 30 megacycles per second, through natural-gas and propane flames containing added alkali halide salts, were investigated over a temperature range from 1900 to 2500 K. The preliminary data of this investigation indicated that the attenuation varies appreciably with the sodium-line-reversal temperatures of the flames and is independent of the particular hydrocarbon fuels that were used for temperature sources and of the particular halide components of the compounds used in the concentrations employed to produce easily measurable attenuation. A reproducibility of plus or minus 25 K was obtainable.

  7. Arbitrary segments of absolute negative mobility

    NASA Astrophysics Data System (ADS)

    Chen, Ruyin; Nie, Linru; Chen, Chongyang; Wang, Chaojie

    2017-01-01

    In previous research work, investigators have reported only one or two segments of absolute negative mobility (ANM) in a periodic potential. In fact, many segments of ANM also occur in the system considered here. We investigate transport of an inertial particle in a gating ratchet periodic potential subjected to a constant bias force. Our numerical results show that its mean velocity can decrease with the bias force increasing, i.e. ANM phenomenon. Furthermore, the ANM can take place arbitrary segments, even up to more than thirty. Intrinsic physical mechanism and conditions for arbitrary segments of ANM to occur are discussed in detail.

  8. Assessment of Projected Changes in Temperature and Precipitation Climatology over the CORDEX-Region 9 via Multi-Model Ensemble Mean of CMIP5 Models

    NASA Astrophysics Data System (ADS)

    Turp, M. Tufan; Ozturk, Tugba; Kurnaz, M. Levent

    2016-04-01

    In this study, we conduct a multi-model ensemble mean approach in order to investigate of projected changes in fundamental climate variables (i.e. mean air temperature, minimum temperature, maximum temperature, and precipitation total) over the CORDEX-Australasia domain based on the outputs of various coupled global climate models (GCMs) participating in the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project (CMIP5). In this respect, in order to analyze projected future changes in temperature and precipitation climatology, seasonal averages, and inter-annual variability over the Australasia (known as Region 9) domain, where is one of fourteen domains of the Coordinated Regional Climate Downscaling Experiment (CORDEX), we focus on historical, RCP4.5 and RCP8.5 experiments of the GCMs for reference- (1981 - 2000), near- (2016 - 2035), mid- (2046 - 2065), and long-term (2081 - 2100), respectively. This research has been supported by Boǧaziçi University Research Fund Grant Number 10421.

  9. Absolute transition probabilities of phosphorus.

    NASA Technical Reports Server (NTRS)

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

    1971-01-01

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

  10. Relativistic Absolutism in Moral Education.

    ERIC Educational Resources Information Center

    Vogt, W. Paul

    1982-01-01

    Discusses Emile Durkheim's "Moral Education: A Study in the Theory and Application of the Sociology of Education," which holds that morally healthy societies may vary in culture and organization but must possess absolute rules of moral behavior. Compares this moral theory with current theory and practice of American educators. (MJL)

  11. Effects of elevated mean and extremely high temperatures on the physio-ecological characteristics of geographically distinctive populations of Cunninghamia lanceolata

    NASA Astrophysics Data System (ADS)

    Zhou, Ting; Jia, Xiaorong; Liao, Huixuan; Peng, Shijia; Peng, Shaolin

    2016-12-01

    Conventional models for predicting species distribution under global warming scenarios often treat one species as a homogeneous whole. In the present study, we selected Cunninghamia lanceolata (C. lanceolata), a widely distributed species in China, to investigate the physio-ecological responses of five populations under different temperature regimes. The results demonstrate that increased mean temperatures induce increased growth performance among northern populations, which exhibited the greatest germination capacity and largest increase in the overlap between the growth curve and the monthly average temperature. However,tolerance of the southern population to extremely high temperatures was stronger than among the population from the northern region,shown by the best growth and the most stable photosynthetic system of the southern population under extremely high temperature. This result indicates that the growth advantage among northern populations due to increased mean temperatures may be weakened by lower tolerance to extremely high temperatures. This finding is antithetical to the predicted results. The theoretical coupling model constructed here illustrates that the difference in growth between populations at high and low latitudes and altitudes under global warming will decrease because of the frequent occurrence of extremely high temperatures.

  12. Effects of elevated mean and extremely high temperatures on the physio-ecological characteristics of geographically distinctive populations of Cunninghamia lanceolata

    PubMed Central

    Zhou, Ting; Jia, Xiaorong; Liao, Huixuan; Peng, Shijia; Peng, Shaolin

    2016-01-01

    Conventional models for predicting species distribution under global warming scenarios often treat one species as a homogeneous whole. In the present study, we selected Cunninghamia lanceolata (C. lanceolata), a widely distributed species in China, to investigate the physio-ecological responses of five populations under different temperature regimes. The results demonstrate that increased mean temperatures induce increased growth performance among northern populations, which exhibited the greatest germination capacity and largest increase in the overlap between the growth curve and the monthly average temperature. However,tolerance of the southern population to extremely high temperatures was stronger than among the population from the northern region,shown by the best growth and the most stable photosynthetic system of the southern population under extremely high temperature. This result indicates that the growth advantage among northern populations due to increased mean temperatures may be weakened by lower tolerance to extremely high temperatures. This finding is antithetical to the predicted results. The theoretical coupling model constructed here illustrates that the difference in growth between populations at high and low latitudes and altitudes under global warming will decrease because of the frequent occurrence of extremely high temperatures. PMID:28004775

  13. The Effect of Harp Music on Heart Rate, Mean Blood Pressure, Respiratory Rate, and Body Temperature in the African Green Monkey

    DTIC Science & Technology

    2007-01-01

    harp music on heart rate, mean blood pressure, respiratory rate, and body temperature in the African green monkey. Journal of Medical Primatology 36:95...13. SUPPLEMENTARY NOTES 14. ABSTRACT Background: The effectiveness of recorded harp music as a tool for relaxation for nonhuman primates (NHP) is...Chlorocebus aethiops). After post-surgical recovery, animals were exposed to recorded harp music . Telemetry data were collected on heart rate, mean

  14. Constructing new satellite-only time series of global mean, sea surface temperature data for climate from ATSR data

    NASA Astrophysics Data System (ADS)

    Veal, Karen; Remedios, John; Ghent, Darren

    2013-04-01

    The Along Track Scanning Radiometers (ATSRs) have provided a near-continuous record of sea surface temperature (SST) data for climate from the launch of ATSR-1 in 1991 to the loss of the Advanced ATSR (AATSR) in April 2012. The intention was always to provide an SST record, independent of in situ data, to corroborate and improve climate data records in recent times. We show that the ATSR record provides a very suitable data set with which to study the recent climate record, particularly during the ATSR-2 and AATSR periods (1995 to 2012) in three major respects. First, ATSR climate time series achieve anomaly accuracies of better than 0.05 K (and high stability). Second, the overlap between instruments allows for excellent determination and removal of biases; between ATSR-2 and AATSR, these are less than 0.05 K for the highest accuracy SST data. Finally, uncertainties on global monthly mean data are less than 0.02 K and hence comparable to those achieved by in situ analyses such as HadSST3. A particular hallmark of the ATSR instruments was their exceptional design for accuracy incorporating high accuracy radiometric calibration, dual-view of the Earth's surface and the use of three thermal emission channels; additional channels are included for cloud clearing in this context. The use of dual-view and multiple thermnal wavelengths allows a number of combinations for retrievals of SST, the most accurate being the dual-view, three-channel retrieval (D3) at nighttime. This restriction is due to the use of the 3.7 micron channel which is sensitive to solar radiation during the day. Extensive work has resulted in a major advances recently resulting in both an operational V2.0 SST product and a further improved ATSR Re-analysis for Climate (ARC) product, a particular feature of the latter being the development of a depth SST product in addition to the skin SST directly determined from satellite data. We will discuss the characteristics of these data sets in terms of

  15. Measurement of the high-temperature Seebeck coefficient of thin films by means of an epitaxially regrown thermometric reference material

    NASA Astrophysics Data System (ADS)

    Ramu, Ashok T.; Mages, Phillip; Zhang, Chong; Imamura, Jeffrey T.; Bowers, John E.

    2012-09-01

    The Seebeck coefficient of a typical thermoelectric material, silicon-doped InGaAs lattice-matched to InP, is measured over a temperature range from 300 K to 550 K. By depositing and patterning a thermometric reference bar of silicon-doped InP adjacent to a bar of the material under test, temperature differences are measured directly. This is in contrast to conventional two-thermocouple techniques that subtract two large temperatures to yield a small temperature difference, a procedure prone to errors. The proposed technique retains the simple instrumentation of two-thermocouple techniques while eliminating the critical dependence of the latter on good thermal contact. The repeatability of the proposed technique is demonstrated to be ±2.6% over three temperature sweeps, while the repeatability of two-thermocouple measurements is about ±5%. The improved repeatability is significant for reliable reporting of the ZT figure of merit, which is proportional to the square of the Seebeck coefficient. The accuracy of the proposed technique depends on the accuracy with which the high-temperature Seebeck coefficient of the reference material may be computed or measured. In this work, the Seebeck coefficient of the reference material, n+ InP, is computed by rigorous solution of the Boltzmann transport equation. The accuracy and repeatability of the proposed technique can be systematically improved by scaling, and the method is easily extensible to other material systems currently being investigated for high thermoelectric energy conversion efficiency.

  16. Changes in Non-Marine Vertebrate Assemblages from the Late Cretaceous of Southern Alberta, Canada and their Relationship to Changes in Mean Annual Temperature

    NASA Astrophysics Data System (ADS)

    Brinkman, D. B.

    2010-12-01

    A series of five vertebrate assemblages from southern Alberta, Canada, (paleolatitude of 58oN) ranging from late Santonian to late Maastrichtian in age together with contemporaneous assemblages from more southern localities provide a basis for interpreting how continental biotas responded to major climate events during this time. A decrease in abundance and diversity of ectothermic mesoreptiles (turtles, crocodiles, and champsosaurs) in southern Alberta that is documented by three successive assemblages of late Campanian and early Maastrichtian age is interpreted as the result of a southern shift of a latitudinal diversity gradient associated with a climatic cooling. The higher diversity of ectothermic mesoreptiles in this region during the late Maastrichtian is interpreted as a northern shift of the diversity gradient resulting from an increase in mean annual temperatures. Latitudinal changes in the distribution or abundance some taxa of fish, turtles, and dinosaurs can also be related to changes in mean annual temperature. The fish Melvius and the turtle Compsemys, which are typical of southern assemblages, occur at higher paleolatitudes during times of high mean annual temperature. The dinosaur Troodon, which has been considered to be more northern in its distribution, is more abundant in southern Alberta during times of lower mean annual temperature. The patterns of distribution of vertebrates in the Campanian and Maastrichtian support the interpretation that the occurrence of ectothermic mesoreptiles in a high-latitude locality of late Turonian-Coniacian age on Axel Heiberg Island (paleolatitude of 71o) is associated with high temperature at that time. These patterns also suggest that faunal changes documented by vertebrate microfossil localities of Cenomanian and Turonian age in southern Utah may also be related in part to an increase in mean annual temperatures during this time.

  17. An atlas of monthly mean distributions of GEOSAT sea surface height, SSMI surface wind speed, AVHRR/2 sea surface temperature, and ECMWF surface wind components during 1988

    NASA Technical Reports Server (NTRS)

    Halpern, D.; Zlotnicki, V.; Newman, J.; Brown, O.; Wentz, F.

    1991-01-01

    Monthly mean global distributions for 1988 are presented with a common color scale and geographical map. Distributions are included for sea surface height variation estimated from GEOSAT; surface wind speed estimated from the Special Sensor Microwave Imager on the Defense Meteorological Satellite Program spacecraft; sea surface temperature estimated from the Advanced Very High Resolution Radiometer on NOAA spacecrafts; and the Cartesian components of the 10m height wind vector computed by the European Center for Medium Range Weather Forecasting. Charts of monthly mean value, sampling distribution, and standard deviation value are displayed. Annual mean distributions are displayed.

  18. Monochromator-Based Absolute Calibration of Radiation Thermometers

    NASA Astrophysics Data System (ADS)

    Keawprasert, T.; Anhalt, K.; Taubert, D. R.; Hartmann, J.

    2011-08-01

    A monochromator integrating-sphere-based spectral comparator facility has been developed to calibrate standard radiation thermometers in terms of the absolute spectral radiance responsivity, traceable to the PTB cryogenic radiometer. The absolute responsivity calibration has been improved using a 75 W xenon lamp with a reflective mirror and imaging optics to a relative standard uncertainty at the peak wavelength of approximately 0.17 % ( k = 1). Via a relative measurement of the out-of-band responsivity, the spectral responsivity of radiation thermometers can be fully characterized. To verify the calibration accuracy, the absolutely calibrated radiation thermometer is used to measure Au and Cu freezing-point temperatures and then to compare the obtained results with the values obtained by absolute methods, resulting in T - T 90 values of +52 mK and -50 mK for the gold and copper fixed points, respectively.

  19. A proposed methodology to control body temperature in patients at risk of hypothermia by means of active rewarming systems.

    PubMed

    Costanzo, Silvia; Cusumano, Alessia; Giaconia, Carlo; Mazzacane, Sante

    2014-01-01

    Hypothermia is a common complication in patients undergoing surgery under general anesthesia. It has been noted that, during the first hour of surgery, the patient's internal temperature (Tcore) decreases by 0.5-1.5°C due to the vasodilatory effect of anesthetic gases, which affect the body's thermoregulatory system by inhibiting vasoconstriction. Thus a continuous check on patient temperature must be carried out. The currently most used methods to avoid hypothermia are based on passive systems (such as blankets reducing body heat loss) and on active ones (thermal blankets, electric or hot-water mattresses, forced hot air, warming lamps, etc.). Within a broader research upon the environmental conditions, pollution, heat stress, and hypothermia risk in operating theatres, the authors set up an experimental investigation by using a warming blanket chosen from several types on sale. Their aim was to identify times and ways the human body reacts to the heat flowing from the blanket and the blanket's effect on the average temperature Tskin and, as a consequence, on Tcore temperature of the patient. The here proposed methodology could allow surgeons to fix in advance the thermal power to supply through a warming blanket for reaching, in a prescribed time, the desired body temperature starting from a given state of hypothermia.

  20. An Analysis of Simulated and Observed Global Mean Near-Surface Air Temperature Anomalies from 1979 to 1999: Trends and Attribution of Causes

    NASA Technical Reports Server (NTRS)

    MacKay, R. M.; Ko, M. K. W.

    2001-01-01

    The 1979 - 1999 response of the climate system to variations in solar spectral irradiance is estimated by comparing the global averaged surface temperature anomalies simulated by a 2D (two dimensional) energy balance climate model to observed temperature anomalies. We perform a multiple regression of southern oscillation index and the individual model responses to solar irradiance variations, stratospheric and tropospheric aerosol loading, stratospheric ozone trends, and greenhouse gases onto each of five near-surface temperature anomaly data sets. We estimate the observed difference in global mean near surface air temperature attributable to the solar irradiance difference between solar maximum and solar minimum to be between 0.06 and 0.11 K, and that 1.1 - 3.8% of the total variance in monthly mean near-surface air temperature data is attributable to nations in solar spectral irradiance. For the five temperature data sets used in our analysis, the trends in raw monthly mean temperature anomaly data have a large range, spanning a factor of 3 from 0.06 to 0.17 K/decade. However. our analysis suggests that trends in monthly temperature anomalies attributable to the combination of greenhouse gas, stratospheric ozone, and tropospheric sulfate aerosol variations are much more consistent among data sets, ranging from 0.16 to 0.24 K/decade. Our model results suggest that roughly half of the warming from greenhouse gases is cancelled by the cooling from changes in stratospheric ozone. Tropospheric sulfate aerosol loading in the present day atmospheric contributes significantly to the net radiative forcing of the present day climate system. However, because the change in magnitude and latitudinal distribution of tropospheric sulfate aerosol has been small over the past 20 years, the change in the direct radiative forcing attributable to changes in aerosol loading over this time is also small.

  1. Absolute calibration of optical flats

    DOEpatents

    Sommargren, Gary E.

    2005-04-05

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

  2. The Absolute Spectrum Polarimeter (ASP)

    NASA Technical Reports Server (NTRS)

    Kogut, A. J.

    2010-01-01

    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.

  3. Achieving Climate Change Absolute Accuracy in Orbit

    NASA Technical Reports Server (NTRS)

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

    2013-01-01

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

  4. Relationships Between Tropical Deep Convection, Tropospheric Mean Temperature and Cloud-Induced Radiative Fluxes on Intraseasonal Time Scales

    NASA Technical Reports Server (NTRS)

    Ramey, Holly S.; Robertson, Franklin R.

    2010-01-01

    Intraseasonal variability of deep convection represents a fundamental mode of variability in the organization of tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, we examine the projection of ISOs on the tropically-averaged temperature and energy budget. The area of interest is the global oceans between 20degN/S. Our analysis then focuses on these questions: (i) How is tropospheric temperature related to tropical deep convection and the associated ice cloud fractional amount (ICF) and ice water path (IWP)? (ii) What is the source of moisture sustaining the convection and what role does deep convection play in mediating the PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007) with some modifications and some additional diagnostics of both clouds and boundary layer thermodynamics. A composite ISO time series of cloud, precipitation and radiation quantities built from nearly 40 events during a six-year period is referenced to the atmospheric temperature signal. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. While there is a decrease in net TOA radiation that develops after the peak in deep convective rainfall, there seems little evidence that an "Infrared Iris"- like mechanism is dominant. Rather, the cloud-induced OLR increase seems largely produced by weakened convection with warmer cloud tops. Tropical ISO events offer an accessible target for studying ISOs not just in terms of propagation mechanisms, but on their global signals of heat, moisture and radiative flux feedback processes.

  5. Using Limited Time Periods as a Means to Elucidate Microwave Sounding Unit Derived Tropospheric Temperature Trend Methods

    DTIC Science & Technology

    2007-07-01

    atmosphere is paramount to our understanding of climate change . The Microwave Sounding Unit (MSU) derived atmospheric temperature trends are used in...that must continue to be addressed as they are used for climate change studies [Mears and Wentz, 2005]. Additionally, the accuracy of methods that...a thorough examination of these data and methods using these data is necessary to insure long-term stability as required for climate change studies

  6. Relationships Between Tropical Deep Convection, Tropospheric Mean Temperature and Cloud-Induced Radiative Fluxes on Intraseasonal Time Scales

    NASA Technical Reports Server (NTRS)

    Ramey, Holly S.; Robertson, Franklin R.

    2009-01-01

    Intraseasonal variability of deep convection represents a fundamental mode of variability in the organization of tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, we examine the projection of ISOs on the tropically-averaged temperature and energy budget. The area of interest is the global oceans between 20oN/S. Our analysis then focuses on these questions: (i) How is tropospheric temperature related to tropical deep convection and the associated ice cloud fractional amount (ICF) and ice water path (IWP)? (ii) What is the source of moisture sustaining the convection and what role does deep convection play in mediating the PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007) with some modifications and some additional diagnostics of both clouds and boundary layer thermodynamics. A composite ISO time series of cloud, precipitation and radiation quantities built from nearly 40 events during a six-year period is referenced to the atmospheric temperature signal. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. While there is a decrease in net TOA radiation that develops after the peak in deep convective rainfall, there seems little evidence that an "Infrared Iris"- like mechanism is dominant. Rather, the cloud-induced OLR increase seems largely produced by weakened convection with warmer cloud tops. Tropical ISO events offer an accessible target for studying ISOs not just in terms of propagation mechanisms, but on their global signals of heat, moisture and radiative flux feedback processes.

  7. Relationships Between Tropical Deep Convection, Tropospheric Mean Temperature and Cloud-Induced Radiative Fluxes on Intraseasonal Time Scales

    NASA Astrophysics Data System (ADS)

    Ramey, H. S.; Robertson, F. R.

    2009-12-01

    Intraseasonal variability of deep convection represents a fundamental mode of variability in the organization of tropical convection. While most studies of intraseasonal oscillations (ISOs) have focused on the spatial propagation and dynamics of convectively coupled circulations, we examine the projection of ISOs on the tropically-averaged temperature and energy budget. The area of interest is the global oceans between 20oN/S. Our analysis then focuses on these questions: (i) How is tropospheric temperature related to tropical deep convection and the associated ice cloud fractional amount (ICF) and ice water path (IWP)? (ii) What is the source of moisture sustaining the convection and what role does deep convection play in mediating the PBL - free atmospheric temperature equilibration? (iii) What affect do convectively generated upper-tropospheric clouds have on the TOA radiation budget? Our methodology is similar to that of Spencer et al., (2007) with some modifications and some additional diagnostics of both clouds and boundary layer thermodynamics. A composite ISO time series of cloud, precipitation and radiation quantities built from nearly 40 events during a six-year period is referenced to the atmospheric temperature signal. The increase of convective precipitation cannot be sustained by evaporation within the domain, implying strong moisture transports into the tropical ocean area. While there is a decrease in net TOA radiation that develops after the peak in deep convective rainfall, there seems little evidence that an “Infrared Iris”-like mechanism is dominant. Rather, the cloud-induced OLR increase seems largely produced by weakened convection with warmer cloud tops. Tropical ISO events offer an accessible target for studying ISOs not just in terms of propagation mechanisms, but on their global signals of heat, moisture and radiative flux feedback processes.

  8. THE REDSHIFT EVOLUTION OF THE MEAN TEMPERATURE, PRESSURE, AND ENTROPY PROFILES IN 80 SPT-SELECTED GALAXY CLUSTERS

    SciTech Connect

    McDonald, M.; Benson, B. A.; Vikhlinin, A.; Aird, K. A.; Allen, S. W.; Bautz, M.; Bayliss, M.; Bleem, L. E.; Bocquet, S.; Brodwin, M.; Carlstrom, J. E.; Chang, C. L.; Cho, H. M.; Clocchiatti, A.; Crawford, T. M.; Crites, A. T.; de Haan, T.; Dobbs, M. A.; Foley, R. J.; Forman, W. R.; George, E. M.; Gladders, M. D.; Gonzalez, A. H.; Halverson, N. W.; Hlavacek-Larrondo, J.; Holder, G. P.; Holzapfel, W. L.; Hrubes, J. D.; Jones, C.; Keisler, R.; Knox, L.; Lee, A. T.; Leitch, E. M.; Liu, J.; Lueker, M.; Luong-Van, D.; Mantz, A.; Marrone, D. P.; McMahon, J. J.; Meyer, S. S.; Miller, E. D.; Mocanu, L.; Mohr, J. J.; Murray, S. S.; Padin, S.; Pryke, C.; Reichardt, C. L.; Rest, A.; Ruhl, J. E.; Saliwanchik, B. R.; Saro, A.; Sayre, J. T.; Schaffer, K. K.; Shirokoff, E.; Spieler, H. G.; Stalder, B.; Stanford, S. A.; Staniszewski, Z.; Stark, A. A.; Story, K. T.; Stubbs, C. W.; Vanderlinde, K.; Vieira, J. D.; Williamson, R.; Zahn, O.; Zenteno, A.

    2014-09-24

    We present the results of an X-ray analysis of 80 galaxy clusters selected in the 2500 deg(2) South Pole Telescope survey and observed with the Chandra X-ray Observatory. We divide the full sample into subsamples of ~20 clusters based on redshift and central density, performing a joint X-ray spectral fit to all clusters in a subsample simultaneously, assuming self-similarity of the temperature profile. This approach allows us to constrain the shape of the temperature profile over 0 < r < 1.5R (500), which would be impossible on a per-cluster basis, since the observations of individual clusters have, on average, 2000 X-ray counts. The results presented here represent the first constraints on the evolution of the average temperature profile from z = 0 to z = 1.2. We find that high-z (0.6 < z < 1.2) clusters are slightly (~30%) cooler both in the inner (r < 0.1R (500)) and outer (r > R (500)) regions than their low-z (0.3 < z < 0.6) counterparts. Combining the average temperature profile with measured gas density profiles from our earlier work, we infer the average pressure and entropy profiles for each subsample. Confirming earlier results from this data set, we find an absence of strong cool cores at high z, manifested in this analysis as a significantly lower observed pressure in the central 0.1R (500) of the high-z cool-core subset of clusters compared to the low-z cool-core subset. Overall, our observed pressure profiles agree well with earlier lower-redshift measurements, suggesting minimal redshift evolution in the pressure profile outside of the core. We find no measurable redshift evolution in the entropy profile at r lsim 0.7R (500)—this may reflect a long-standing balance between cooling and feedback over long timescales and large physical scales. We observe a slight flattening of the entropy profile at r gsim R (500) in our high-z subsample. This flattening is consistent with a temperature bias due to the enhanced (~3×) rate at which group-mass (~2

  9. Mid-infrared spectroscopy of Uranus from the Spitzer Infrared Spectrometer: 1. Determination of the mean temperature structure of the upper troposphere and stratosphere

    NASA Astrophysics Data System (ADS)

    Orton, Glenn S.; Fletcher, Leigh N.; Moses, Julianne I.; Mainzer, Amy K.; Hines, Dean; Hammel, Heidi B.; Martin-Torres, F. Javier; Burgdorf, Martin; Merlet, Cecile; Line, Michael R.

    2014-11-01

    On 2007 December 16-17, spectra were acquired of the disk of Uranus by the Spitzer Infrared Spectrometer (IRS), ten days after the planet's equinox, when its equator was close to the sub-Earth point. This spectrum provides the highest-resolution broad-band spectrum ever obtained for Uranus from space, allowing a determination of the disk-averaged temperature and molecule composition to a greater degree of accuracy than ever before. The temperature profiles derived from the Voyager radio occultation experiment by Lindal et al. (Lindal, G.F., Lyons, J.R., Sweetnam, D.N., Eshleman, V.R., Hinson, D.P. [1987]. J. Geophys. Res. 92, 14987-15001) and revisions suggested by Sromovsky et al. (Sromovsky, L.A., Fry, P.A., Kim, J.H. [2011]. Icarus 215, 292-312) that match these data best are those that assume a high abundance of methane in the deep atmosphere. However, none of these model profiles provides a satisfactory fit over the full spectral range sampled. This result could be the result of spatial differences between global and low-latitudinal regions, changes in time, missing continuum opacity sources such as stratospheric hazes or unknown tropospheric constituents, or undiagnosed systematic problems with either the Voyager radio-occultation or the Spitzer IRS data sets. The spectrum is compatible with the stratospheric temperatures derived from the Voyager ultraviolet occultations measurements by Herbert et al. (Herbert, F. et al. [1987]. J. Geophys. Res. 92, 15093-15109), but it is incompatible with the hot stratospheric temperatures derived from the same data by Stevens et al. (Stevens, M.H., Strobel, D.F., Herbert, F.H. [1993]. Icarus 101, 45-63). Thermospheric temperatures determined from the analysis of the observed H2 quadrupole emission features are colder than those derived by Herbert et al. at pressures less than ∼1 μbar. Extrapolation of the nominal model spectrum to far-infrared through millimeter wavelengths shows that the spectrum arising solely from H2

  10. Observations of accumulation mode aerosol composition and soot carbon concentrations by means of a high-temperature volatility technique

    NASA Astrophysics Data System (ADS)

    Smith, Michael H.; O'Dowd, Colin D.

    1996-08-01

    A high-temperature volatility system has been deployed for the measurement of the composition and concentration of the accumulation mode aerosol (0.05 μm < r < 1 μm) within the atmospheric boundary layer. This instrumentation comprises a volatility system based around a Particle Measuring Systems ASASP-X optical particle counter, which was operated together with an aethalometer for the direct observation of soot carbon concentrations. By cycling the heater tube through a range of temperatures from near ambient to over 1000°C, size-differentiated information upon aerosol composition may be obtained. Furthermore, by careful selection of analysis temperatures, discrimination is possible between elemental carbon and the more volatile fractions of the soot carbon aerosol. Observations made over the North Sea near the Dutch coast and in the central United Kingdom are presented for differing environmental conditions with soot carbon concentrations ranging from about 100 to over 6000 ng m-3. For polluted conditions over the North Sea the volatility technique clearly showed the dominance of soot carbon particles over other aerosol components with a narrow carbon particle distribution of mode radius around 0.06 μm accounting for about 80% of all particles with radii below 0.1 μm. Under polluted conditions, only about 25% of the total soot carbon aerosol comprised elemental carbon (with the remainder consisting of more volatile material), whereas this proportion rose to around 50% in the lower carbon loadings found in a cleaner maritime air mass. The use of soot carbon loadings as a tracer of anthropogenic aerosol inputs to oceanic regions is explored on the basis of measurements from a NE Atlantic cruise.

  11. Absolute calibration of optical tweezers

    SciTech Connect

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

    2006-03-27

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

  12. Mean field analysis of the high temperature magnetic properties of terbium iron garnet in strong DC fields

    NASA Astrophysics Data System (ADS)

    Lahoubi, Mahieddine; Wang, Wei

    2015-11-01

    This paper is devoted to the description of the magnetic phase diagrams (MPD) together with a special interest to the determination of more precise values of some reliable parameters at the compensation point, Tcomp=243.5±0.5 K of the terbium iron garnet, Tb3Fe5O12 or TbIG. Using isothermal magnetizations performed on single crystal in strong DC magnetic fields up to 200 kOe applied along the <111>, <110> and <100> directions within the temperature range 128-295 K, field-induced phase transitions between collinear and canted phases are observed in the vicinity of Tcomp at critical fields, Hc2. In comparison with the measurement at zero external magnetic field, the specific heat, Cp(T) at 80 kOe along <111> shows an excess around Tcomp characterized by an anomaly which has a width in the boundaries of the canted phase and a maximum at 252 K, the more accurate value of the critical temperature, TC* of the MPD in the (Hc2-T) plane. Better determinations of the molecular field coefficients which represent the magnetic interactions on the Tb sublattice are obtained by an improved molecular field model based on the saturation effects of the Tb sublattice and the differential susceptibility contribution due to the Fe sublattices to the total magnetic susceptibility of TbIG. The results are discussed in terms of the previous theoretical studies of the MPD predicted for weakly anisotropic ferrimagnets.

  13. Species and temperature measurement in H2/O2 rocket flow fields by means of Raman scattering diagnostics

    NASA Technical Reports Server (NTRS)

    Degroot, Wim A.; Weiss, Jonathan M.

    1992-01-01

    Validation of Computational Fluid Dynamics (CFD) codes developed for prediction and evaluation of rocket performance is hampered by a lack of experimental data. Non-intrusive laser based diagnostics are needed to provide spatially and temporally resolved gas dynamic and fluid dynamic measurements. This paper reports the first non-intrusive temperature and species measurements in the plume of a 110 N gaseous hydrogen/oxygen thruster at and below ambient pressures, obtained with spontaneous Raman spectroscopy. Measurements at 10 mm downstream of the exit plane are compared with predictions from a numerical solution of the axisymmetric Navier-Stokes and species transport equations with chemical kinetics, which fully model the combustor-nozzle-plume flowfield. The experimentally determined oxygen number density at the centerline at 10 mm downstream of the exit plane is four times that predicted by the model. The experimental number density data fall between those numerically predicted for the exit and 10 mm downstream planes in both magnitude and radial gradient. The predicted temperature levels are within 10 to 15 percent of measured values. Some of the discrepancies between experimental data and predictions result from not modeling the three dimensional core flow injection mixing process, facility back pressure effects, and possible diffuser-thruster interactions.

  14. The mean ozone profile and its temperature sensitivity in the upper stratosphere and lower mesosphere - An analysis of LIMS observations

    NASA Astrophysics Data System (ADS)

    Froidevaux, Lucien; Allen, Mark; Berman, Stanley; Daughton, Alan

    1989-05-01

    Multiple simultaneous LIMS (Limb Infrared Monitor of the Stratosphere) observations of both O3 and temperature T in the upper stratosphere and lower mesosphere are analyzed to derive O3-T correlations for comparisons with model calculations. The zonally averaged O3 profile is compared with results from a simplified photochemical model that assumes O3 to be in a photochemical steady state. The model profile is systematically lower than the observed profile. Key parameters are identified in which changes can systematically increase the O3 profile in both the stratosphere and the mesosphere. The LIMS-derived values for the sensitivity of O3 to changes in T are compared with equilibrium model calculations which include the T-driven opacity feedback effect on photodissociation rate constants. The theoretical O3 response to temperature perturbations is investigated. It is shown how the O3-T sensitivity coefficient is affected by zonal and vertical advection terms as well as by the photochemical coupling between O3 and T.

  15. Accurate absolute GPS positioning through satellite clock error estimation

    NASA Astrophysics Data System (ADS)

    Han, S.-C.; Kwon, J. H.; Jekeli, C.

    2001-05-01

    An algorithm for very accurate absolute positioning through Global Positioning System (GPS) satellite clock estimation has been developed. Using International GPS Service (IGS) precise orbits and measurements, GPS clock errors were estimated at 30-s intervals. Compared to values determined by the Jet Propulsion Laboratory, the agreement was at the level of about 0.1 ns (3 cm). The clock error estimates were then applied to an absolute positioning algorithm in both static and kinematic modes. For the static case, an IGS station was selected and the coordinates were estimated every 30 s. The estimated absolute position coordinates and the known values had a mean difference of up to 18 cm with standard deviation less than 2 cm. For the kinematic case, data obtained every second from a GPS buoy were tested and the result from the absolute positioning was compared to a differential GPS (DGPS) solution. The mean differences between the coordinates estimated by the two methods are less than 40 cm and the standard deviations are less than 25 cm. It was verified that this poorer standard deviation on 1-s position results is due to the clock error interpolation from 30-s estimates with Selective Availability (SA). After SA was turned off, higher-rate clock error estimates (such as 1 s) could be obtained by a simple interpolation with negligible corruption. Therefore, the proposed absolute positioning technique can be used to within a few centimeters' precision at any rate by estimating 30-s satellite clock errors and interpolating them.

  16. Micron Accurate Absolute Ranging System: Range Extension

    NASA Technical Reports Server (NTRS)

    Smalley, Larry L.; Smith, Kely L.

    1999-01-01

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

  17. Copping with Uncertainties in Mapping Extreme and Mean Temperatures at the Regional Level for Risk Management in Agriculture: A Case Study in Galicia, NW Spain

    NASA Astrophysics Data System (ADS)

    Mirás Avalos, J. M.; Vidal Vázquez, E.; Sande Fouz, P.; Paz González, A.

    2012-04-01

    Temperature is one of the main factors regulating crop growth and duration of crop cycle. Climate risk can be identified by characteristics such us geographic area (areal extent), time of year it is most likely to occur and its severity. Knowledge of the geographic coverage of mean, maxima and minima temperatures as well as the spatial distribution of this variable above or below a given threshold is fundamental for designing viable practices in the agriculture sector. Thus, managing temperature effects in agriculture needs reliable regional maps from which information can be obtained by downscaling at the farm scale. Several techniques are currently employed to create discretized, continuous surfaces from point data through a set of spatial interpolation techniques. Geostatistics, based in the random function theory is commonly used in the assessment of uncertainty associated with a spatially correlated variable, such as most climatic parameters, including temperature. The aim of this study was to provide a comparative analysis of various methods used for mapping monthly maximum, minimum and mean air temperatures in Galicia, northwest Spain over a 0.5 x 0.5 km grid size. The air temperature datasets involved more than 140 meteorological stations irregularly distributed in the region. Methods, included statistical and of spatial dependence analysis and mapping by inverse distance weighting (IDW) and several kriging techniques, including residual kriging (RK), collocated cokriging (COK) and kriging with an external drift (KED). There was a significant relationship between temperature and altitude for the study data sets. Interpolated monthly air temperature maps, produced by IDW indicate that the general pattern of values varied from one month to another, and therefore it can not be assessed based on previous records. Mean maxima and minima temperatures showed spatial dependence, which was described by spherical and gaussian variograms. First, IDW was used to

  18. Use of mean residence time of water, flowrate, and equilibrium temperature indicated by water geothermometers to rank geothermal resources. Application to the thermal water circuits of Northern Calabria

    NASA Astrophysics Data System (ADS)

    Apollaro, Carmine; Vespasiano, Giovanni; Muto, Francesco; De Rosa, Rosanna; Barca, Donatella; Marini, Luigi

    2016-12-01

    A new hydro-geochemical survey was carried out on the thermal sites of Northern Calabria. By use of new and historical data, it was possible to improve the knowledge on the deep systems of interest. First, thermal waters were characterized by means of a classical approach, including water classifications, use of the triangular diagram of Cl-Li-B, and geothermometry through suitably selected functions. Then, the tritium-based mean residence time and flowrate of the thermal waters of Northern Calabria were used to evaluate the volume of the geothermal reservoir and its component terms. Based on these results, the heat stored in the geothermal reservoir was computed by means of the volume method. Their natural heat discharge was also calculated. These parameters as well as the reservoir temperature indicated by water geothermometers were used to rank the geothermal resources of Northern Calabria. Sambiase resulted to be the thermal circuit of highest geothermal potential.

  19. An atlas of monthly mean distributions of SSMI surface wind speed, ARGOS buoy drift, AVHRR/2 sea surface temperature, and ECMWF surface wind components during 1991

    NASA Technical Reports Server (NTRS)

    Halpern, D.; Knauss, W.; Brown, O.; Wentz, F.

    1993-01-01

    The following monthly mean global distributions for 1991 are presented with a common color scale and geographical map: 10-m height wind speed estimated from the Special Sensor Microwave Imager (SSMI) on a United States Air Force Defense Meteorological Satellite Program (DMSP) spacecraft; sea surface temperature estimated from the advanced very high resolution radiometer (AVHRR/2) on a U.S. National Oceanic and Atmospheric Administration (NOAA) spacecraft; Cartesian components of free-drifting buoys which are tracked by the ARGOS navigation system on NOAA satellites; and Cartesian components of the 10-m height wind vector computed by the European Center for Medium-Range Weather Forecasting (ECMWF). Charts of monthly mean value, sampling distribution, and standard deviation value are displayed. Annual mean distributions are displayed.

  20. An atlas of monthly mean distributions of SSMI surface wind speed, ARGOS buoy drift, AVHRR/2 sea surface temperature, and ECMWF surface wind components during 1990

    NASA Technical Reports Server (NTRS)

    Halpern, D.; Knauss, W.; Brown, O.; Wentz, F.

    1993-01-01

    The following monthly mean global distributions for 1990 are proposed with a common color scale and geographical map: 10-m height wind speed estimated from the Special Sensor Microwave Imager (SSMI) on a United States (US) Air Force Defense Meteorological Satellite Program (DMSP) spacecraft; sea surface temperature estimated from the advanced very high resolution radiometer (AVHRR/2) on a U.S. National Oceanic and Atmospheric Administration (NOAA) spacecraft; Cartesian components of free drifting buoys which are tracked by the ARGOS navigation system on NOAA satellites; and Cartesian components on the 10-m height wind vector computed by the European Center for Medium-Range Weather Forecasting (ECMWF). Charts of monthly mean value, sampling distribution, and standard deviation values are displayed. Annual mean distributions are displayed.

  1. Spatial downscaling and mapping of daily precipitation and air temperature using daily station data and monthly mean maps

    NASA Astrophysics Data System (ADS)

    Flint, A. L.; Flint, L. E.; Stern, M. A.

    2013-12-01

    Accurate maps of daily weather variables are an essential component of hydrologic and ecologic modeling. Here we present a four-step method that uses daily station data and transient monthly maps of precipitation and air temperature. This method uses the monthly maps to help interpolate between stations for more accurate production of daily maps at any spatial resolution. The first step analyzes the quality of the each station's data using a discrepancy analysis that compares statistics derived from a statistical jack-knifing approach with a time-series evaluation of discrepancies generated for each station. Although several methods could be used for the second step of producing initial maps, such as kriging, splines, etc., we used a gradient plus inverse distance squared method that was developed to produce accurate climate maps for sparse data regions with widely separated and few climate stations, far fewer than would be needed for techniques such as kriging. The gradient plus inverse distance squared method uses local gradients in the climate parameters, easting, northing, and elevation, to adjust the inverse distance squared estimates for local gradients such as lapse rates, inversions, or rain shadows at scales of 10's of meters to kilometers. The third step is to downscale World Wide Web (web) based transient monthly data, such as Precipitation-Elevation Regression on Independent Slope Method (PRISM) for the US (4 km or 800 m maps) or Climate Research Unit (CRU 3.1) data sets (40 km for global applications) to the scale of the daily data's digital elevation model. In the final step the downscaled transient monthly maps are used to adjust the daily time-series mapped data (~30 maps/month) for each month. These adjustments are used to scale daily maps so that summing them for precipitation or averaging them for temperature would more accurately reproduce the variability in selected monthly maps. This method allows for individual days to have maxima or minima

  2. Effects of the Substrate Temperature in AuN Thin Films by Means of X-Ray Diffraction

    SciTech Connect

    Devia, A.; Benavides, V.; Castillo, H. A.; Quintero, J.

    2006-12-04

    Gold is used in electronic industry like electric conductor for products such as computers, mobiles phones, etc; with the drawback that it is one of the most expensive metals in the market. Gold Nitride is a new material, having excellent physics properties like high hardness, high melting point, high electric conductivity, chemical inertia and good thermodynamic stabily among others. At the moment its study is more about electronics, optics, mechanical properties and growth of the films. AuN thin films were produced by the PAPVD (Plasma assisted Physics Vapor Deposition) method, using the pulsed arc technique in a mono-vaporizer system. These films were created with an Au target of 99% purity and deposited on stainless steel 304. It was observed that heating the substrate produces small stoichiometric changes in the film, which makes small changes in the diffraction patterns to appear, like widening in the Au orientation, since the composicional gradient is varying according to the substrate temperature. Au 4f and N1s narrow spectra were analyzed using XPS (X-Ray Photoelectron Spectroscopy), in order to observe stoichiometry in the films.

  3. Is There Enough Solar EUV to Maintain the Global Mean Thermospheric Temperature? Revisiting a 37-year-old Problem (Invited)

    NASA Astrophysics Data System (ADS)

    Solomon, S. C.

    2010-12-01

    Since 1973, when Roble and Dickinson first attempted to reconcile measurements of the solar extreme-ultraviolet spectrum with thermospheric temperatures [R. G. Roble and R. E. Dickinson, J. Geophys. Res., 78, 249, 1973], investigators have struggled to understand thermosphere, ionosphere, photoelectron, and airglow observations in the context of our evolving understanding of solar energetic photons. Despite a rich history of observations by satellite and rocket instruments, spanning the spectral range from soft X-rays through the extreme-ultraviolet to the far ultraviolet, and covering most of four solar cycles, uncertainties in the magnitude and variability of the solar spectrum have persisted, particularly at the shortest wavelengths. A recurring theme of these issues has been an ongoing desire of modelers for more photons, especially energetic ones. Now, with simultaneous solar observations by the SEE instrument on the TIMED satellite, the SEM instrument on the SOHO spacecraft, the EVE instrument on the Solar Dynamics Observatory, and calibration rocket flights, we should at last be able to close this chapter in aeronomy. However, new challenges continue to materialize, including the anomalously low levels of solar EUV during the 2008-2009 solar minimum, and the surprisingly rapid cooling of the thermosphere due to increasing levels of anthropogenic carbon dioxide and other greenhouse gases. This presentation reviews the history of solar measurements and their interplay with modeling efforts, assesses the current state of knowledge, identifies key remaining uncertainties, and suggests the need for revision of thermospheric cooling rates.

  4. Effects of the Substrate Temperature in AuN Thin Films by Means of X-Ray Diffraction

    NASA Astrophysics Data System (ADS)

    Devia, A.; Benavides, V.; Castillo, H. A.; Quintero, J.

    2006-12-01

    Gold is used in electronic industry like electric conductor for products such as computers, mobiles phones, etc; with the drawback that it is one of the most expensive metals in the market. Gold Nitride is a new material, having excellent physics properties like high hardness, high melting point, high electric conductivity, chemical inertia and good thermodynamic stabily among others. At the moment its study is more about electronics, optics, mechanical properties and growth of the films. AuN thin films were produced by the PAPVD (Plasma assisted Physics Vapor Deposition) method, using the pulsed arc technique in a mono-vaporizer system. These films were created with an Au target of 99% purity and deposited on stainless steel 304. It was observed that heating the substrate produces small stoichiometric changes in the film, which makes small changes in the diffraction patterns to appear, like widening in the Au orientation, since the composicional gradient is varying according to the substrate temperature. Au 4f and N1s narrow spectra were analyzed using XPS (X-Ray Photoelectron Spectroscopy), in order to observe stoichiometry in the films.

  5. Analysis of the total solar irradiance composite and their contribution to global mean air surface temperature rise

    NASA Astrophysics Data System (ADS)

    Scafetta, N.

    2008-12-01

    Herein I discuss and propose updated satellite composites of the total solar irradiance covering the period 1978-2008. The composites are compiled from measurements made with the three ACRIM experiments. Measurements from the NIMBUS7/ERB, the ERBS/ERBE satellite experiments and a total solar irradiance proxy reconstruction are used to fill the gap from June 1989 to October 1991 between ACRIM1 and ACRIM2 experiments. The result of the analysis does suggests that the total solar irradiance did increase from 1980 to 2002. The climate implications of the alternative satellite composites are discussed by using a phenomenological climate model which depends on two characteristics time response at tau1 =0.4 year and tau2=8-12 years, as determined phenomenologically [Scafetta, JGR 2008]. Reconstructions of total solar irradiance signature on climate during the last four centuries are discussed. The solar variability appears to have significantly contributed to climate change during the last four centuries, including the last century. Indirectly, the model suggests that the preindustrial climate experienced a large variability which is incompatible with an Hockey Stick temperature graph.

  6. On the problems related to natural wet bulb temperature indirect evaluation for the assessment of hot thermal environments by means of WBGT.

    PubMed

    D'Ambrosio Alfano, Francesca Romana; Palella, Boris Igor; Riccio, Giuseppe

    2012-11-01

    This paper deals with the indirect evaluation of the natural wet bulb temperature, t (nw), one of the two quantities forming the basis of the well-known wet bulb globe temperature (WBGT) index, considered worldwide to be a suitable and user-friendly tool for the preliminary assessment of hot thermal environments. This quantity can be measured by a wet bulb thermometer (a temperature sensor covered with a wetted wick naturally ventilated) or, if this is not available, calculated from other microclimatic parameters (i.e. the air temperature, the globe temperature, the air velocity, and the humidity) using a quite trivial energy balance equation. Because of the strong non-linear structure of such an equation, the risk of a multiplicity of steady state solutions could result in the failure to obtain a reliable index evaluation. To dispel all doubts, this work carries out an in-depth analysis of the heat balance equation to be solved for the indirect evaluation of the natural wet bulb temperature. A preliminary investigation of each heat flow term involved in the heat balance on the sensor has been carried out; in a second phase a special continuation method has been implemented, highlighting the effect of microclimatic parameters on the multiplicity of solutions. Results show that under free convection the evaluation produces a single solution only under uniform conditions, whereas in the presence of even slight differences between the air temperature and the mean radiant temperature, there can be as many as three solutions. This phenomenon, if confirmed by a further experimental investigation, could become a difficult matter since a sensor, in principle, has to read a unique value of the quantity measured. In any case, from a numerical point of view, the presence of many values of tnw greatly reduces the possibility of an indirect WBGT calculation from the other involved physical quantities; as a consequence, the indirect evaluation of WBGT should be clearly avoided

  7. From Hubble's Next Generation Spectral Library (NGSL) to Absolute Fluxes

    NASA Astrophysics Data System (ADS)

    Heap, S. R.; Lindler, D.

    2016-05-01

    Hubble's Next Generation Spectral Library (NGSL) consists of R˜1000 spectra of 374 stars of assorted temperature, gravity, and metallicity. Each spectrum covers the wavelength range, 0.18-1.03 μ. The library can be viewed and/or downloaded from the website, http://archive.stsci.edu/prepds/stisngsl/. 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 have therefore developed an observing procedure, data-reduction procedure, and correction algorithms that should yield fluxes with uncertainties less than 1%.

  8. Temperature exerts no influence on organic matter δ13C of surface soil along the 400 mm isopleth of mean annual precipitation in China

    NASA Astrophysics Data System (ADS)

    Jia, Yufu; Wang, Guoan; Tan, Qiqi; Chen, Zixun

    2016-09-01

    Soil organic carbon is the largest pool of carbon in the terrestrial ecosystem, and its isotopic composition is affected by a number of factors. However, the influence of environmental factors, especially temperature, on soil organic carbon isotope values (δ13CSOM) is poorly constrained. This impedes the application of the variability of organic carbon isotopes to reconstructions of paleoclimate, paleoecology, and global carbon cycling. Given the considerable temperature gradient along the 400 mm isohyet (isopleth of mean annual precipitation - MAP) in China, this isohyet provides ideal experimental sites for studying the influence of temperature on soil organic carbon isotopes. In this study, the effect of temperature on surface soil δ13C was assessed by a comprehensive investigation of 27 sites across a temperature gradient along the isohyet. Results demonstrate that temperature does not play a role in soil δ13C. This suggests that organic carbon isotopes in sediments cannot be used for paleotemperature reconstruction and that the effect of temperature on organic carbon isotopes can be neglected in the reconstruction of paleoclimate and paleovegetation. Multiple regressions with MAT (mean annual temperature), MAP, altitude, latitude, and longitude as independent variables and δ13CSOM as the dependent variable show that these five environmental factors together account for only 9 % of soil δ13C variance. However, one-way ANOVA analyses suggest that soil type and vegetation type are significant factors influencing soil δ13C. Multiple regressions, in which the five aforementioned environmental factors were taken as quantitative variables, and vegetation type, soil type based on the Chinese Soil Taxonomy, and World Reference Base (WRB) soil type were separately used as dummy variables, show that 36.2, 37.4, and 29.7 %, respectively, of the variability in soil δ13C are explained. Compared to the multiple regressions in which only quantitative environmental

  9. Comparing maps of mean monthly surface temperature and precipitation for Alaska and adjacent areas of Canada produced by two different methods

    USGS Publications Warehouse

    Simpson, James J.; Hufford, Gary L.; Daly, Christopher; Berg, Jared S.; Fleming, Michael D.

    2005-01-01

    Maps of mean monthly surface temperature and precipitation for Alaska and adjacent areas of Canada, produced by Oregon State University's Spatial Climate Analysis Service (SCAS) and the Alaska Geospatial Data Clearinghouse (AGDC), were analyzed. Because both sets of maps are generally available and in use by the community, there is a need to document differences between the processes and input data sets used by the two groups to produce their respective set of maps and to identify similarities and differences between the two sets of maps and possible reasons for the differences. These differences do not affect the observed large-scale patterns of seasonal and annual variability. Alaska is divided into interior and coastal zones, with consistent but different variability, separated by a transition region. The transition region has high interannual variability but low long-term mean variability. Both data sets support the four major ecosystems and ecosystem transition zone identified in our earlier work. Differences between the two sets of maps do occur, however, on the regional scale; they reflect differences in physiographic domains and in the treatment of these domains by the two groups (AGDC, SCAS). These differences also provide guidance for an improved observational network for Alaska. On the basis of validation with independent in situ data, we conclude that the data set produced by SCAS provides the best spatial coverage of Alaskan long-term mean monthly surface temperature and precipitation currently available. ?? The Arctic Institute of North America.

  10. Absolute calorimetric calibration of low energy brachytherapy sources

    NASA Astrophysics Data System (ADS)

    Stump, Kurt E.

    In the past decade there has been a dramatic increase in the use of permanent radioactive source implants in the treatment of prostate cancer. A small radioactive source encapsulated in a titanium shell is used in this type of treatment. The radioisotopes used are generally 125I or 103Pd. Both of these isotopes have relatively short half-lives, 59.4 days and 16.99 days, respectively, and have low-energy emissions and a low dose rate. These factors make these sources well suited for this application, but the calibration of these sources poses significant metrological challenges. The current standard calibration technique involves the measurement of ionization in air to determine the source air-kerma strength. While this has proved to be an improvement over previous techniques, the method has been shown to be metrologically impure and may not be the ideal means of calbrating these sources. Calorimetric methods have long been viewed to be the most fundamental means of determining source strength for a radiation source. This is because calorimetry provides a direct measurement of source energy. However, due to the low energy and low power of the sources described above, current calorimetric methods are inadequate. This thesis presents work oriented toward developing novel methods to provide direct and absolute measurements of source power for low-energy low dose rate brachytherapy sources. The method is the first use of an actively temperature-controlled radiation absorber using the electrical substitution method to determine total contained source power of these sources. The instrument described operates at cryogenic temperatures. The method employed provides a direct measurement of source power. The work presented here is focused upon building a metrological foundation upon which to establish power-based calibrations of clinical-strength sources. To that end instrument performance has been assessed for these source strengths. The intent is to establish the limits of

  11. Absolute bioavailability of quinine formulations in Nigeria.

    PubMed

    Babalola, C P; Bolaji, O O; Ogunbona, F A; Ezeomah, E

    2004-09-01

    This study compared the absolute bioavailability of quinine sulphate as capsule and as tablet against the intravenous (i.v.) infusion of the drug in twelve male volunteers. Six of the volunteers received intravenous infusion over 4 h as well as the capsule formulation of the drug in a cross-over manner, while the other six received the tablet formulation. Blood samples were taken at predetermined time intervals and plasma analysed for quinine (QN) using reversed-phase HPLC method. QN was rapidly absorbed after the two oral formulations with average t(max) of 2.67 h for both capsule and tablet. The mean elimination half-life of QN from the i.v. and oral dosage forms varied between 10 and 13.5 hr and were not statistically different (P > 0.05). On the contrary, the maximum plasma concentration (C(max)) and area under the curve (AUC) from capsule were comparable to those from i.v. (P > 0.05), while these values were markedly higher than values from tablet formulation (P < 0.05). The therapeutic QN plasma levels were not achieved with the tablet formulation. The absolute bioavailability (F) were 73% (C.l., 53.3 - 92.4%) and 39 % (C.I., 21.7 - 56.6%) for the capsule and tablet respectively and the difference was significant (P < 0.05). The subtherapeutic levels obtained from the tablet form used in this study may cause treatment failure during malaria and caution should be taken when predictions are made from results obtained from different formulations of QN.

  12. Orientation cues for high-flying nocturnal insect migrants: do turbulence-induced temperature and velocity fluctuations indicate the mean wind flow?

    PubMed

    Reynolds, Andy M; Reynolds, Don R; Smith, Alan D; Chapman, Jason W

    2010-12-29

    Migratory insects flying at high altitude at night often show a degree of common alignment, sometimes with quite small angular dispersions around the mean. The observed orientation directions are often close to the downwind direction and this would seemingly be adaptive in that large insects could add their self-propelled speed to the wind speed, thus maximising their displacement in a given time. There are increasing indications that high-altitude orientation may be maintained by some intrinsic property of the wind rather than by visual perception of relative ground movement. Therefore, we first examined whether migrating insects could deduce the mean wind direction from the turbulent fluctuations in temperature. Within the atmospheric boundary-layer, temperature records show characteristic ramp-cliff structures, and insects flying downwind would move through these ramps whilst those flying crosswind would not. However, analysis of vertical-looking radar data on the common orientations of nocturnally migrating insects in the UK produced no evidence that the migrants actually use temperature ramps as orientation cues. This suggests that insects rely on turbulent velocity and acceleration cues, and refocuses attention on how these can be detected, especially as small-scale turbulence is usually held to be directionally invariant (isotropic). In the second part of the paper we present a theoretical analysis and simulations showing that velocity fluctuations and accelerations felt by an insect are predicted to be anisotropic even when the small-scale turbulence (measured at a fixed point or along the trajectory of a fluid-particle) is isotropic. Our results thus provide further evidence that insects do indeed use turbulent velocity and acceleration cues as indicators of the mean wind direction.

  13. Why must a solar forcing be larger than a CO2 forcing to cause the same global mean surface temperature change?

    NASA Astrophysics Data System (ADS)

    Modak, Angshuman; Bala, Govindasamy; Cao, Long; Caldeira, Ken

    2016-04-01

    Many previous studies have shown that a solar forcing must be greater than a CO2 forcing to cause the same global mean surface temperature change but a process-based mechanistic explanation is lacking in the literature. In this study, we investigate the physical mechanisms responsible for the lower efficacy of solar forcing compared to an equivalent CO2 forcing. Radiative forcing is estimated using the Gregory method that regresses top-of-atmosphere (TOA) radiative flux against the change in global mean surface temperature. For a 2.25% increase in solar irradiance that produces the same long term global mean warming as a doubling of CO2 concentration, we estimate that the efficacy of solar forcing is ∼80% relative to CO2 forcing in the NCAR CAM5 climate model. We find that the fast tropospheric cloud adjustments especially over land and stratospheric warming in the first four months cause the slope of the regression between the TOA net radiative fluxes and surface temperature to be steeper in the solar forcing case. This steeper slope indicates a stronger net negative feedback and hence correspondingly a larger solar forcing than CO2 forcing for the same equilibrium surface warming. Evidence is provided that rapid land surface warming in the first four months sets up a land-sea contrast that markedly affects radiative forcing and the climate feedback parameter over this period. We also confirm the robustness of our results using simulations from the Hadley Centre climate model. Our study has important implications for estimating the magnitude of climate change caused by volcanic eruptions, solar geoengineering and past climate changes caused by change in solar irradiance such as Maunder minimum.

  14. Two-particle response in cluster dynamical mean-field theory: formalism and application to the Raman response of high-temperature superconductors.

    PubMed

    Lin, Nan; Gull, Emanuel; Millis, Andrew J

    2012-09-07

    A method is presented for the unbiased numerical computation of two-particle response functions of correlated electron materials via a solution of the dynamical mean-field equations in the presence of a perturbing field. The power of the method is demonstrated via a computation of the Raman B(1g) and B(2g) scattering intensities of the two-dimensional Hubbard model in parameter regimes believed to be relevant to high-temperature superconductivity. The theory reproduces the "two-magnon" peak characteristic of the Raman intensity of insulating parent compounds of high-T(c) copper oxide superconductors, and shows how it evolves to a quasiparticle response, as carriers are added. The method can be applied in any situation where a solution of equilibrium dynamical mean-field equations is feasible.

  15. What is Needed for Absolute Paleointensity?

    NASA Astrophysics Data System (ADS)

    Valet, J. P.

    2015-12-01

    Many alternative approaches to the Thellier and Thellier technique for absolute paleointensity have been proposed during the past twenty years. One reason is the time consuming aspect of the experiments. Another reason is to avoid uncertainties in determinations of the paleofield which are mostly linked to the presence of multidomain grains. Despite great care taken by these new techniques, there is no indication that they always provide the right answer and in fact sometimes fail. We are convinced that the most valid approach remains the original double heating Thellier protocol provided that natural remanence is controlled by pure magnetite with a narrow distribution of small grain sizes, mostly single domains. The presence of titanium, even in small amount generates biases which yield incorrect field values. Single domain grains frequently dominate the magnetization of glass samples, which explains the success of this selective approach. They are also present in volcanic lava flows but much less frequently, and therefore contribute to the low success rate of most experiments. However the loss of at least 70% of the magnetization at very high temperatures prior to the Curie point appears to be an essential prerequisite that increases the success rate to almost 100% and has been validated from historical flows and from recent studies. This requirement can easily be tested by thermal demagnetization while low temperature experiments can document the detection of single domain magnetite using the δFC/δZFC parameter as suggested (Moskowitz et al, 1993) for biogenic magnetite.

  16. Mean winds, temperatures and the 16- and 5-day planetary waves in the mesosphere and lower thermosphere over Bear Lake Observatory (42° N 111° W)

    NASA Astrophysics Data System (ADS)

    Day, K. A.; Taylor, M. J.; Mitchell, N. J.

    2011-11-01

    Atmospheric temperatures and winds in the mesosphere and lower thermosphere have been measured simultaneously using the Aura satellite and a meteor radar at Bear Lake Observatory (42° N, 111° W). The data presented in this study is from the interval March 2008 to July 2011. The mean winds observed in the summer-time over Bear Lake Observatory show the meridional winds to be equatorward at all heights during April-August and to reach monthly-mean speeds of -12 ms-1. The mean winds are closely related to temperatures in this region of the atmosphere and in the summer the coldest mesospheric temperatures occur about two weeks after the strongest equatorward meridional winds. In other seasons the meridional winds are poleward, reaching monthly-mean values of up to 12 ms-1. The zonal winds are eastward through most of the year and in the summer strong eastward zonal wind shears of up to ~4.5 ms-1 km-1 are present. However, westward winds are observed at the upper heights in winter and sometimes during the equinoxes. Considerable inter-annual variability is observed in the mean winds and temperatures. Comparisons of the observed winds with URAP and HWM-07 reveal some significant differences. Our radar zonal wind observations are generally more weakly eastward than these predicted by the URAP model zonal winds. Considering the radar meridional winds, in comparison to the HWM-07 our observations reveal equatorward flow at all heights in the summer whereas HWM-07 suggests that only weakly equatorward, or even poleward, flows occur at the lower heights. However, the zonal winds observed by the radar and modelled by HWM-07 are generally similar in structure and strength. Signatures of the 16- and 5-day planetary waves are clearly evident in both the radar-wind data and Aura-temperature. Short-lived wave events can reach large amplitudes of up to ~15 ms-1 and 8 K and 20 ms-1 and 10 K for the 16- and 5-day wave, respectively. A clear seasonal and short-term variability are

  17. Assessing Epistemic Sophistication by Considering Domain-Specific Absolute and Multiplicistic Beliefs Separately

    ERIC Educational Resources Information Center

    Peter, Johannes; Rosman, Tom; Mayer, Anne-Kathrin; Leichner, Nikolas; Krampen, Günter

    2016-01-01

    Background: Particularly in higher education, not only a view of science as a means of finding absolute truths (absolutism), but also a view of science as generally tentative (multiplicism) can be unsophisticated and obstructive for learning. Most quantitative epistemic belief inventories neglect this and understand epistemic sophistication as…

  18. Sex Ratios at Birth and Environmental Temperatures

    NASA Astrophysics Data System (ADS)

    Lerchl, Alexander

    The relationship between average monthly air temperature and sex ratios at birth (SRB) was analyzed for children born in Germany during the period 1946-1995. Both the absolute temperature and - more markedly - the monthly temperature deviations from the overall mean were significantly positively correlated with the SRB (P<0.01) when temperatures were time-lagged against the SRB data by -10 or -11months. It is concluded that the sex of the offspring is partially determined by environmental temperatures prior to conception.

  19. Assessment of the performance of CORDEX-SA experiments in simulating seasonal mean temperature over the Himalayan region for the present climate: Part I

    NASA Astrophysics Data System (ADS)

    Nengker, T.; Choudhary, A.; Dimri, A. P.

    2017-03-01

    The ability of an ensemble of five regional climate models (hereafter RCMs) under Coordinated Regional Climate Downscaling Experiments-South Asia (hereafter, CORDEX-SA) in simulating the key features of present day near surface mean air temperature (Tmean) climatology (1970-2005) over the Himalayan region is studied. The purpose of this paper is to understand the consistency in the performance of models across the ensemble, space and seasons. For this a number of statistical measures like trend, correlation, variance, probability distribution function etc. are applied to evaluate the performance of models against observation and simultaneously the underlying uncertainties between them for four different seasons. The most evident finding from the study is the presence of a large cold bias (-6 to -8 °C) which is systematically seen across all the models and across space and time over the Himalayan region. However, these RCMs with its fine resolution perform extremely well in capturing the spatial distribution of the temperature features as indicated by a consistently high spatial correlation (greater than 0.9) with the observation in all seasons. In spite of underestimation in simulated temperature and general intensification of cold bias with increasing elevation the models show a greater rate of warming than the observation throughout entire altitudinal stretch of study region. During winter, the simulated rate of warming gets even higher at high altitudes. Moreover, a seasonal response of model performance and its spatial variability to elevation is found.

  20. Absolute optical metrology : nanometers to kilometers

    NASA Technical Reports Server (NTRS)

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

    2005-01-01

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

  1. ON A SUFFICIENT CONDITION FOR ABSOLUTE CONTINUITY.

    DTIC Science & Technology

    The formulation of a condition which yields absolute continuity when combined with continuity and bounded variation is the problem considered in the...Briefly, the formulation is achieved through a discussion which develops a proof by contradiction of a sufficiently theorem for absolute continuity which uses in its hypothesis the condition of continuity and bounded variation .

  2. Monolithically integrated absolute frequency comb laser system

    SciTech Connect

    Wanke, Michael C.

    2016-07-12

    Rather than down-convert optical frequencies, a QCL laser system directly generates a THz frequency comb in a compact monolithically integrated chip that can be locked to an absolute frequency without the need of a frequency-comb synthesizer. The monolithic, absolute frequency comb can provide a THz frequency reference and tool for high-resolution broad band spectroscopy.

  3. Temperature and impurity transport studies of heated tokamak plasmas by means of a collisional-radiative model of x-ray emission from Mo30+ to Mo39+

    PubMed

    Pacella; Fournier; Zerbini; Finkenthal; Mattioli; May; Goldstein

    2000-05-01

    This work presents and interprets, by means of detailed atomic calculations, observations of L-shell (n = 3-->n = 2) transitions in highly ionized molybdenum, the main intrinsic heavy impurity in the Frascati tokamak upgrade plasmas. These hot plasmas were obtained by additional electron cyclotron resonance heating (ECRH), at the frequency of 140 Ghz, during the current ramp-up phase of the discharge. Injecting 400 kW on axis and 800 kW slightly off axis, the peak central electron temperature reached 8.0 and 7.0 keV, respectively, for a time much longer than the ionization equilibrium time of the molybdenum ions. X-ray emissions from rarely observed high charge states, Mo30+ to Mo39+, have been studied with moderate spectral resolution (lambda/delta lambda approximately 150) and a time resolution of 5 ms. A sophisticated collisional-radiative model for the study of molybdenum ions in plasmas with electron temperature in the range 4-20 keV is presented. The sensitivity of the x-ray emission to the temperature and to impurity transport processes is discussed. This model has been then used to investigate two different plasma scenarios. In the first regime the ECRH heating occurs on axis during the current ramp up phase, when the magnetic shear is evolving from negative to zero up to the half radius. The spectrum is well reproduced with the molybdenum ions in coronal equilibrium and with a central impurity peaking. In the second regime, at the beginning of the current flat top when magnetic shear is monotonic and sawtoothing activity is appearing, the lowest charge states (Mo33+ to Mo30+), populated off axis, are affected by anomalous transport and the total molybdenum profile is found to be flat up to the half radius. We conclude with the presentation of "synthetic spectra" computed for even higher temperature plasmas that are expected in future experiments with higher ECRH power input.

  4. Grape harvest dates as indicator of spring-summer mean maxima temperature variations in the Minho region (NW of Portugal) since the 19th century

    NASA Astrophysics Data System (ADS)

    Moreno, J.; Fatela, F.; Moreno, F.; Leorri, E.; Taborda, R.; Trigo, R.

    2016-06-01

    This paper reports a climatic reconstruction approach for the Minho region (NW of Portugal) using grape harvest dates (GHD) as proxy of surface air temperature. This new GHD series was built based on the records from a set of local and regional newspapers (1854-1978) and the annuals of a Wine Producers Cooperative (1978-2010). The strong inverse correlation between Minho GHD and the mean maxima temperatures of the preceding March to August months (GSTmax), registered at the Braga weather station for the overlap period 1941-2009, allowed a reconstruction, with associated statistical uncertainties, of the regional GSTmax back to 1856. These were then used to characterize the main climatic episodes in the region during the last 154 years. The most noticeable feature that emerges from the comparison of the Minho GSTmax with the global annual average temperatures of Jones et al. (2013) is that these regional temperatures, in clear contrast with the global warming observed from around 1990 onwards, show no noteworthy increasing trend. The influence of climatic variability was examined also in terms of the relations between GSTmax (1950-2009) and the main meteorological teleconnection patterns affecting the North Atlantic European sector where the Minho region is included. Data support the hypothesis that persistent positive modes of spring-summer Scandinavian (SCA) and summer East Atlantic/Western Russia patterns triggered lower GSTmax, especially in the 60s-80s. The search for solar imprints in the Minho region climate identified the SCA mode as a promising connection between the two, since it is significantly inversely correlated with both, the TSI and the GSTmax. Like in other traditional European viticultural regions, the Minho GHD have shown to be a valuable tool for understanding the interactions between large-scale circulation modes and regional/local climatic conditions. Besides it will deliver a reliable assessment of climatic proxies from geological record

  5. Absolute instability of the Gaussian wake profile

    NASA Technical Reports Server (NTRS)

    Hultgren, Lennart S.; Aggarwal, Arun K.

    1987-01-01

    Linear parallel-flow stability theory has been used to investigate the effect of viscosity on the local absolute instability of a family of wake profiles with a Gaussian velocity distribution. The type of local instability, i.e., convective or absolute, is determined by the location of a branch-point singularity with zero group velocity of the complex dispersion relation for the instability waves. The effects of viscosity were found to be weak for values of the wake Reynolds number, based on the center-line velocity defect and the wake half-width, larger than about 400. Absolute instability occurs only for sufficiently large values of the center-line wake defect. The critical value of this parameter increases with decreasing wake Reynolds number, thereby indicating a shrinking region of absolute instability with decreasing wake Reynolds number. If backflow is not allowed, absolute instability does not occur for wake Reynolds numbers smaller than about 38.

  6. Progress Report of CNES Activities Regarding the Absolute Calibration Method

    DTIC Science & Technology

    2010-11-01

    several receivers (Ashtech Z12-T, Septentrio PolaRx2, and Dicom GTR50) and a GNSS signal simulator (Spirent 4760) according to the temperature and...laboratories, Ashtech Z12- T, Septentrio PolaRx2, and Dicom GTR50, can be calibrated with the absolute method [6,8]. The last works concerned the...Ashtech, Septentrio, and Dicom receiver calibrations. Table 2. Uncertainty of the different receiver calibrations. Uncertainty Source

  7. The Electromotive Series and Other Non-Absolute Scales

    NASA Astrophysics Data System (ADS)

    Peckham, Gavin D.

    1998-01-01

    This article describes an analogy which may be used to illustrate the principles that underlie the establishment of non-absolute scales of measurements that are evaluated relative to a chosen reference point. The analogy is interwoven with the establishment of the electromotive series, but may be extended to other parameters such as the Celsius and Fahrenheit temperature scales, potential energies, formation and reaction enthalpies, etc.

  8. Gyrokinetic Statistical Absolute Equilibrium and Turbulence

    SciTech Connect

    Jian-Zhou Zhu and Gregory W. Hammett

    2011-01-10

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

  9. Temperature variation of ultralow frequency modes and mean square displacements in solid lasamide (diuretic drug) studied by 35Cl-NQR, X-ray and DFT/QTAIM.

    PubMed

    Latosińska, Jolanta Natalia; Latosińska, Magdalena; Kasprzak, Jerzy; Tomczak, Magdalena; Maurin, Jan Krzysztof

    2012-10-25

    The application of combined (35)Cl-NQR/X-ray/DFT/QTAIM methods to study the temperature variation of anisotropic displacement parameters and ultralow frequency modes of anharmonic torsional vibrations in the solid state is illustrated on the example of 2,4-dichloro-5-sulfamolybenzoic acid (lasamide, DSBA) which is a diuretic and an intermediate in the synthesis of furosemide and thus its common impurity. The crystallographic structure of lasamide is solved by X-ray diffraction and refined to a final R-factor of 3.06% at room temperature. Lasamide is found to crystallize in the triclinic space group P-1, with two equivalent molecules in the unit cell a = 7.5984(3) Å, b = 8.3158(3) Å, c = 8.6892(3) Å; α = 81.212(3)°, β = 73.799(3)°, γ = 67.599(3)°. Its molecules form symmetric dimers linked by two short and linear intermolecular hydrogen bonds O-H···O (O-H···O = 2.648 Å and ∠OHO = 171.5°), which are further linked by weaker and longer intermolecular hydrogen bonds N-H···O (N-H···O = 2.965 Å and ∠NHO = 166.4°). Two (35)Cl-NQR resonance frequencies, 36.899 and 37.129 MHz, revealed at room temperature are assigned to chlorine sites at the ortho and para positions, relative to the carboxyl functional group, respectively. The difference in C-Cl(1) and C-Cl(2) bond lengths only slightly affects the value of (35)Cl-NQR frequencies, which results mainly from chemical inequivalence of chlorine atoms but also involvement in different intermolecular interactions pattern. The smooth decrease in both (35)Cl-NQR frequencies with increasing temperature in the range of 77-300 K testifies to the averaging of EFG tensor at each chlorine site due to anharmonic torsional vibrations. Lasamide is thermally stable; no temperature-induced release of chlorine or decomposition of this compound is detected. The temperature dependence of ultralow frequency modes of anharmonic small-angle internal torsional vibrations averaging EFG tensor and mean square angle

  10. Hawking Absorption and Planck Absolute Entropy of Kerr-Newman Black Hole

    NASA Astrophysics Data System (ADS)

    Ali, M. Hossain; Banu, Akhtara

    2006-03-01

    We find the existence of a quantum thermal effect, “Hawking absorption.” near the inner horizon of the Kerr Newman black hole. Redefining the entropy, temperature, angular velocity, and electric potential of the black hole, we give a new formulation of the Bekenstein Smarr formula. The redefined entropy vanishes for absolute zero temperature of the black hole and hence it is interpreted as the Planck absolute entropy of the KN black hole.

  11. Absolute quantitation of protein posttranslational modification isoform.

    PubMed

    Yang, Zhu; Li, Ning

    2015-01-01

    Mass spectrometry has been widely applied in characterization and quantification of proteins from complex biological samples. Because the numbers of absolute amounts of proteins are needed in construction of mathematical models for molecular systems of various biological phenotypes and phenomena, a number of quantitative proteomic methods have been adopted to measure absolute quantities of proteins using mass spectrometry. The liquid chromatography-tandem mass spectrometry (LC-MS/MS) coupled with internal peptide standards, i.e., the stable isotope-coded peptide dilution series, which was originated from the field of analytical chemistry, becomes a widely applied method in absolute quantitative proteomics research. This approach provides more and more absolute protein quantitation results of high confidence. As quantitative study of posttranslational modification (PTM) that modulates the biological activity of proteins is crucial for biological science and each isoform may contribute a unique biological function, degradation, and/or subcellular location, the absolute quantitation of protein PTM isoforms has become more relevant to its biological significance. In order to obtain the absolute cellular amount of a PTM isoform of a protein accurately, impacts of protein fractionation, protein enrichment, and proteolytic digestion yield should be taken into consideration and those effects before differentially stable isotope-coded PTM peptide standards are spiked into sample peptides have to be corrected. Assisted with stable isotope-labeled peptide standards, the absolute quantitation of isoforms of posttranslationally modified protein (AQUIP) method takes all these factors into account and determines the absolute amount of a protein PTM isoform from the absolute amount of the protein of interest and the PTM occupancy at the site of the protein. The absolute amount of the protein of interest is inferred by quantifying both the absolute amounts of a few PTM

  12. Lars Onsager Prize: The mean field solution for Hard Sphere Jamming and a new scenario for the low temperature landscape of glasses

    NASA Astrophysics Data System (ADS)

    Parisi, Giorgio

    In a hard spheres systems particles cannot overlap. Increasing the density we reach a point where most of the particles are blocked and the density cannot be increased any more: this is the jamming point. The jamming point separates the phase, where all the constraint can be satisfied, from an unsatifiable phase, where spheres do have to overlap. A scaling theory of the behavior around the jamming critical point has been formulated and a few critical exponents have been introduced. The exponents are apparently super-universal, as far as they do seem to be independent from the space dimensions. The mean field version of the model (i.e. the infinite dimensions limit) has been solved analytically using broken replica symmetry techniques and the computed critical exponents have been found in a remarkable agreement with three-dimensional and two-dimensional numerical results and experiments. The theory predicts in hard spheres (in glasses) a new transition (the Gardener transition) from the replica symmetric phase to the replica broken phase at high density (at low temperature), in agreement with simulations on hard sphere systems. I will briefly discuss the possible consequences of this new picture on the very low temperature behavior of glasses in the quantum regime.

  13. Composition and temperature dependent electronic structures of NiS2 -xSex alloys: First-principles dynamical mean-field theory approach

    NASA Astrophysics Data System (ADS)

    Moon, Chang-Youn; Kang, Hanhim; Jang, Bo Gyu; Shim, Ji Hoon

    2015-12-01

    We investigate the evolution of the electronic structure of NiS2 -xSex alloys with varying temperature and composition x by using the combined approach of density-functional theory and dynamical mean-field theory. Adopting realistic alloy structures containing S and Se dimers, we map their electronic correlation strength on the phase diagram and observe the metal-insulator transition (MIT) at the composition x =0.5 , which is consistent with the experimental measurements. The temperature dependence of the local magnetic susceptibility is found to show a typical Curie-Weiss-like behavior in the insulating phase while it shows a constant Pauli-like behavior in the metallic phase. A comparison of the electronic structures for NiS2 and NiSe2 in different lattice structures suggests that the MIT in this alloy system can be classified as of bandwidth-control type, where the change in the hybridization strength between Ni d and chalcogen p orbitals is the most important parameter.

  14. The determination of deep temperatures by means of the CO-CO2-H2-H2O geothermometer: an example using fumaroles in the Campi Flegrei, Italy

    NASA Astrophysics Data System (ADS)

    Tedesco, D.; Sabroux, J. C.

    1987-02-01

    Chromatographic analyses of fumarolic gases, collected in sampling bottles containing an alkaline solution, have been carried out using a thermal conductivity detector and a flame ionization detector, after catalytic conversion of CO and CH4. The latter method enables the concentration of carbon monoxide to be measured with sufficient accuracy for use in a CO-CO2-H2-H2O geothermometer. Application of this geothermometer to fumaroles in the crater of Solfatara in the Campi Flegrei, Italy, indicates that they are fed from a steam reservoir at 250±15 °C and at 10-36±2atm of oxygen. On the other hand, the CH4-CO2-H2-H2O geothermobarometer seems to re-equilibrate at superficial temperatures and cannot be used for infering thermodynamic conditions at depth. Regular sampling of these fumaroles together with a geothermometric interpretation of the gas analyses provides a means of monitoring, with comparative accuracy, the chemical and thermal evolution of the hydrothermal reservoir below the Solfatara crater. Such monitoring would probably detect an increase in temperature at depth and the injection of magmatic gas into the reservoir.

  15. Mean annual temperatures of mid-latitude regions derived from δ(2)H values of wood lignin methoxyl groups and its implications for paleoclimate studies.

    PubMed

    Anhäuser, Tobias; Greule, Markus; Polag, Daniela; Bowen, Gabriel J; Keppler, Frank

    2017-01-01

    Tree-rings are widely used climate archives providing annual resolutions on centennial to millennial timescales. Stable isotope ratios of tree-rings have been applied to assist with the delineation of climate parameters such as temperature and precipitation. Here, we investigated stable hydrogen isotope ratios (expressed as δ(2)H values) of lignin methoxyl groups of wood from various tree species collected along a ~3500km north-south transect across Europe with mean annual temperatures (MAT) ranging from -4 to +17°C. We found a strong linear relationship between MATs and δ(2)H values of wood lignin methoxyl groups. We used this relationship to predict MATs from randomly collected wood samples and found general agreement between predicted and observed MATs for the mid-latitudes on a global scale. Our results are discussed in context of their paleoclimate relevance and suggest that δ(2)H values of lignin methoxyl groups might have the potential to reconstruct MATs when applied on mid-latitudinal tree-ring chronologies of the Late Holocene.

  16. Assessment of Simulated Changes in Air Temperature and Precipitation over Central Asia via Multi-Model Ensemble Means of CMIP5 Models

    NASA Astrophysics Data System (ADS)

    Ozturk, Tugba; Tufan Turp, M.; Türkeş, Murat; Kurnaz, M. Levent

    2014-05-01

    In this study, we conducted a multi-model ensemble mean approach in order to investigate the projected changes in surface air temperatures and precipitation totals over Central Asia. Even though there are totally sixty seven different models of thirty modeling groups all around the world participating in the World Climate Research Programme (WCRP) Coupled Model Intercomparison Project (CMIP5), forty four models among them were used due to data availability. Central Asia (known as Region 8), which is one of twelve domains of the Coordinated Regional Climate Downscaling Experiment (CORDEX), was chosen as a domain of study. In this respect, we focused on two distinct scenarios (i.e. RCP4.5 and RCP8.5) for three different future periods (i.e. 2010-2040, 2040 - 2070 and 2070 - 2100) to examine accurately the foreseen changes in two fundamental climate variables (surface air temperature and precipitation total) for the Central Asia region. This work has been supported by Bogazici University BAP under project number 7362. One of the authors (MLK) was partially supported by Mercator-IPC Fellowship Program.

  17. Absolute realization of low BRDF value

    NASA Astrophysics Data System (ADS)

    Liu, Zilong; Liao, Ningfang; Li, Ping; Wang, Yu

    2010-10-01

    Low BRDF value is widespread used in many critical domains such as space and military fairs. These values below 0.1 Sr-1 . So the Absolute realization of these value is the most critical issue in the absolute measurement of BRDF. To develop the Absolute value realization theory of BRDF , defining an arithmetic operators of BRDF , achieving an absolute measurement Eq. of BRDF based on radiance. This is a new theory method to solve the realization problem of low BRDF value. This theory method is realized on a self-designed common double orientation structure in space. By designing an adding structure to extend the range of the measurement system and a control and processing software, Absolute realization of low BRDF value is achieved. A material of low BRDF value is measured in this measurement system and the spectral BRDF value are showed within different angles allover the space. All these values are below 0.4 Sr-1 . This process is a representative procedure about the measurement of low BRDF value. A corresponding uncertainty analysis of this measurement data is given depend on the new theory of absolute realization and the performance of the measurement system. The relative expand uncertainty of the measurement data is 0.078. This uncertainty analysis is suitable for all measurements using the new theory of absolute realization and the corresponding measurement system.

  18. Regional mean and variability characteristics of temperature and precipitation over Thailand in 1961-2000 by a regional climate model and their evaluation

    NASA Astrophysics Data System (ADS)

    Torsri, Kritanai; Octaviani, Mega; Manomaiphiboon, Kasemsan; Towprayoon, Sirintornthep

    2013-07-01

    This study presents the characterization of regional means and variability of temperature and precipitation in 1961-2000 for Thailand using regional climate model RegCM3. Two fine-resolution (20 km) simulations forced by ERA-40 reanalysis data were performed, with the default land covers and with a land-cover modification strategy suggested by a previous work. The strategy was shown to substantially alleviate the problem of systematic underestimation of temperature given by the default simulation, for most part of Thailand in both dry and wet seasons. The degree of bias in precipitation tends to vary differently in every sub-region and season considered. The patterns of seasonal variation of both climatic variables are acceptably reproduced. Simulated 850-hPa winds have general agreement with those of ERA-40, but wind speed is overestimated over the Gulf of Thailand during the dry months, potentially bringing excessive moisture to and causing more rain than actual in the south. Long-term trends in temperature are reasonably predicted by the model while those in observed and simulated precipitations for upper Thailand are in the opposite directions. Apart from the conventional methods used in characterization, spectral decomposition using Kolmogorov-Zurbenko filters was applied to inspect the model's capability of accounting for variability (here, in terms of variance) in both climatic variables on three temporal scales (short term, seasonal, and long term). The model was found to closely estimate the total variances in the original time series and fairly predict the relative variance contributions on all temporal scales. The latter finding is in line with the results from an additional spectral coherence analysis. Overall, the model was shown to be acceptably adequate for use in support of further climate studies for Thailand, and its evident strength is the capability of reproducing seasonal characteristics and, to a lesser degree, trends.

  19. Past atmospheric krypton and xenon over the last 24,000 years from trapped air in polar ice cores: A potential constraint on mean ocean temperature

    NASA Astrophysics Data System (ADS)

    Kawamura, Kenji; Severinghaus, Jeffrey P.; Baggenstos, Daniel; Orsi, Anais; Buizert, Christo; Aoki, Shuji; Nakazawa, Takakiyo

    2015-04-01

    Prior work has shown that atmospheric concentrations of Kr and Xe respond mainly to mean ocean temperature variations, due to their strongly temperature-dependent solubility in liquid water and due to the fact that no significant sources or sinks exist in the ocean-atmosphere system (Headly and Severinghaus, 2007 JGR; Ritz et al., 2011 QSR). Because roughly 80% of the ocean's volume is colder than 4° C, and cold water holds more gas than warm water, the atmospheric noble gases Kr and Xe mainly record changes in deep ocean temperature. Records from the WAIS Divide, GISP2 and Dome Fuji ice cores show a large increase in the Kr/N2 and Xe/N2 over the time interval 19 ka to 15 ka, equivalent to ~1.5 ° C deep ocean warming (from the WAIS data and a box model). This time interval is contemporaneous with Heinrich Stadial 1, a time of strong retreat of southern hemisphere mountain glaciers, rapid warming of southern mid-latitude surface waters, and weak northern hemisphere monsoons, all consistent with a south-shifted ITCZ and weak Atlantic Meridional Overturning Circulation (the 'bipolar see-saw' in its warm-south mode). These new data are consistent with the idea that the initial rise in CO2 at the last Termination was caused by a strong increase in the rate at which the deep ocean is exposed to the atmosphere around Antarctica (known as 'ventilation') and the concomitant release of CO2 to the atmosphere. The WAIS Divide data also suggest a slow-down of ocean warming between 15 ka and 13 ka, and then the second strong warming by about one degree until ~11.5 ka, roughly coincident with Antarctic Cold Reversal and Younger Dryas, respectively.

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

    SciTech Connect

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

    2013-02-15

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

  1. Linear mean free path and quadratic temperature dependence of electron-phonon scattering rate in V{sub 82}Al{sub 18-x}Fe{sub x} alloys at low temperature

    SciTech Connect

    Jana, R. N.; Sinha, S.; Meikap, A. K.

    2015-05-15

    We have reported a comprehensive study on temperature and disorder dependence of inelastic electron dephasing scattering rate in disordered V{sub 82}Al{sub 18-x}Fe{sub x} alloys. The dephasing scattering time has been measured by analysis of low field magnetoresistance using the weak localization theory. In absence of magnetic field the variation of low temperature resistivity rise follows the relation Δρ(T)∝−ρ{sub 0}{sup 5/2}√(T), which is well described by three-dimensional electron-electron interactions. The temperature-independent dephasing rate strongly depends on disorder and follows the relation τ{sub 0}{sup −1}∝l{sub e}, where l{sub e} is the electron elastic mean free path. The inelastic electron-phonon scattering rate obeying the anomalous relation τ{sub e−ph}{sup −1}∝T{sup 2}l{sub e}. This anomalous behavior of τ{sub e−ph}{sup −1} cannot be explained in terms of current theories for electron-phonon scattering in impure dirty conductors.

  2. A New Gimmick for Assigning Absolute Configuration.

    ERIC Educational Resources Information Center

    Ayorinde, F. O.

    1983-01-01

    A five-step procedure is provided to help students in making the assignment absolute configuration less bothersome. Examples for both single (2-butanol) and multi-chiral carbon (3-chloro-2-butanol) molecules are included. (JN)

  3. Magnifying absolute instruments for optically homogeneous regions

    SciTech Connect

    Tyc, Tomas

    2011-09-15

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

  4. The Simplicity Argument and Absolute Morality

    ERIC Educational Resources Information Center

    Mijuskovic, Ben

    1975-01-01

    In this paper the author has maintained that there is a similarity of thought to be found in the writings of Cudworth, Emerson, and Husserl in his investigation of an absolute system of morality. (Author/RK)

  5. Absolute cross sections of compound nucleus reactions

    NASA Astrophysics Data System (ADS)

    Capurro, O. A.

    1993-11-01

    The program SEEF is a Fortran IV computer code for the extraction of absolute cross sections of compound nucleus reactions. When the evaporation residue is fed by its parents, only cumulative cross sections will be obtained from off-line gamma ray measurements. But, if one has the parent excitation function (experimental or calculated), this code will make it possible to determine absolute cross sections of any exit channel.

  6. Absolute Plate Velocities from Seismic Anisotropy

    NASA Astrophysics Data System (ADS)

    Kreemer, Corné; Zheng, Lin; Gordon, Richard

    2015-04-01

    The orientation of seismic anisotropy inferred beneath plate interiors may provide a means to estimate the motions of the plate relative to the sub-asthenospheric mantle. Here we analyze two global sets of shear-wave splitting data, that of Kreemer [2009] and an updated and expanded data set, to estimate plate motions and to better understand the dispersion of the data, correlations in the errors, and their relation to plate speed. We also explore the effect of using geologically current plate velocities (i.e., the MORVEL set of angular velocities [DeMets et al. 2010]) compared with geodetically current plate velocities (i.e., the GSRM v1.2 angular velocities [Kreemer et al. 2014]). We demonstrate that the errors in plate motion azimuths inferred from shear-wave splitting beneath any one tectonic plate are correlated with the errors of other azimuths from the same plate. To account for these correlations, we adopt a two-tier analysis: First, find the pole of rotation and confidence limits for each plate individually. Second, solve for the best fit to these poles while constraining relative plate angular velocities to consistency with the MORVEL relative plate angular velocities. The SKS-MORVEL absolute plate angular velocities (based on the Kreemer [2009] data set) are determined from the poles from eight plates weighted proportionally to the root-mean-square velocity of each plate. SKS-MORVEL indicates that eight plates (Amur, Antarctica, Caribbean, Eurasia, Lwandle, Somalia, Sundaland, and Yangtze) have angular velocities that differ insignificantly from zero. The net rotation of the lithosphere is 0.25±0.11° Ma-1 (95% confidence limits) right-handed about 57.1°S, 68.6°E. The within-plate dispersion of seismic anisotropy for oceanic lithosphere (σ=19.2° ) differs insignificantly from that for continental lithosphere (σ=21.6° ). The between-plate dispersion, however, is significantly smaller for oceanic lithosphere (σ=7.4° ) than for continental

  7. Rising Mean Annual Temperature Increases Carbon Flux and Alters Partitioning, but Does Not Change Ecosystem Carbon Storage in Hawaiian Tropical Montane Wet Forest

    NASA Astrophysics Data System (ADS)

    Litton, C. M.; Giardina, C. P.; Selmants, P.

    2014-12-01

    Terrestrial ecosystem carbon (C) storage exceeds that in the atmosphere by a factor of four, and represents a dynamic balance among C input, allocation, and loss. This balance is likely being altered by climate change, but the response of terrestrial C cycling to warming remains poorly quantified, particularly in tropical forests which play a disproportionately large role in the global C cycle. Over the past five years, we have quantified above- and belowground C pools and fluxes in nine permanent plots spanning a 5.2°C mean annual temperature (MAT) gradient (13-18.2°C) in Hawaiian tropical montane wet forest. This elevation gradient is unique in that substrate type and age, soil type, soil water balance, canopy vegetation, and disturbance history are constant, allowing us to isolate the impact of long-term, whole ecosystem warming on C input, allocation, loss and storage. Across the gradient, soil respiration, litterfall, litter decomposition, total belowground C flux, aboveground net primary productivity, and estimates of gross primary production (GPP) all increase linearly and positively with MAT. Carbon partitioning is dynamic, shifting from below- to aboveground with warming, likely in response to a warming-induced increase in the cycling and availability of soil nutrients. In contrast to observed patterns in C flux, live biomass C, soil C, and total ecosystem C pools remained remarkably constant with MAT. There was also no difference in soil bacterial taxon richness, phylogenetic diversity, or community composition with MAT. Taken together these results indicate that in tropical montane wet forests, increased temperatures in the absence of water limitation or disturbance will accelerate C cycling, will not alter ecosystem C storage, and will shift the products of photosynthesis from below- to aboveground. These results agree with an increasing number of studies, and collectively provide a unique insight into anticipated warming-induced changes in tropical

  8. Lead-lag relationships between global mean temperature and the atmospheric CO2 content in dependence of the type and time scale of the forcing

    NASA Astrophysics Data System (ADS)

    Muryshev, Kirill E.; Eliseev, Alexey V.; Mokhov, Igor I.; Timazhev, Alexandr V.

    2017-01-01

    By employing an Earth system model of intermediate complexity (EMIC) developed at the A.M. Obukhov Institute of Atmospheric Physics, Russian Academy of Sciences (IAP RAS CM), mutual lags between global mean surface air temperature, T and the atmospheric CO2 content, q, in dependence of the type and time scale of the external forcing are explored. In the simulation, which follows the protocol of the Coupled Models Intercomparison Project, phase 5, T leads q for volcanically-induced climate variations. In contrast, T lags behind q for changes caused by anthropogenic CO2 emissions into the atmosphere. In additional idealized numerical experiments, driven by periodic external emissions of carbon dioxide into the atmosphere, T always lags behind q as expected. In contrast, if the model is driven by the periodic non-greenhouse radiative forcing, T leads q for the external forcing time scale ≤4 ×102 yr, while q leads T at longer scales. The latter is an example that lagged correlations do not necessarily represent causal relationships in a system. This apparently counter-intuitive result, however, is a direct consequence of i) temperature sensitivity of the soil carbon stock (which decreases if climate is warmed and increases if climate is cooled), ii) conservation of total mass of carbon in the system in the absence of external carbon emissions, iii) increased importance of the oceanic branch of the carbon cycle at longer time scales. The results obtained with an EMIC are further interpreted with a conceptual Earth system model consisting of an energy balance climate model and a globally averaged carbon cycle model. The obtained results have implications to the empirical studies attempting to understand the origins of the contemporary climate change by applying lead-lag relationships to empirical data.

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

    NASA Astrophysics Data System (ADS)

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

    2014-11-01

    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.

  10. Climate change and heat-related mortality in six cities Part 2: climate model evaluation and projected impacts from changes in the mean and variability of temperature with climate change.

    PubMed

    Gosling, Simon N; McGregor, Glenn R; Lowe, Jason A

    2009-01-01

    Previous assessments of the impacts of climate change on heat-related mortality use the "delta method" to create temperature projection time series that are applied to temperature-mortality models to estimate future mortality impacts. The delta method means that climate model bias in the modelled present does not influence the temperature projection time series and impacts. However, the delta method assumes that climate change will result only in a change in the mean temperature but there is evidence that there will also be changes in the variability of temperature with climate change. The aim of this paper is to demonstrate the importance of considering changes in temperature variability with climate change in impacts assessments of future heat-related mortality. We investigate future heat-related mortality impacts in six cities (Boston, Budapest, Dallas, Lisbon, London and Sydney) by applying temperature projections from the UK Meteorological Office HadCM3 climate model to the temperature-mortality models constructed and validated in Part 1. We investigate the impacts for four cases based on various combinations of mean and variability changes in temperature with climate change. The results demonstrate that higher mortality is attributed to increases in the mean and variability of temperature with climate change rather than with the change in mean temperature alone. This has implications for interpreting existing impacts estimates that have used the delta method. We present a novel method for the creation of temperature projection time series that includes changes in the mean and variability of temperature with climate change and is not influenced by climate model bias in the modelled present. The method should be useful for future impacts assessments. Few studies consider the implications that the limitations of the climate model may have on the heat-related mortality impacts. Here, we demonstrate the importance of considering this by conducting an evaluation of

  11. Trade-off between carbon emission and effluent quality of activated sludge processes under seasonal variations of wastewater temperature and mean cell retention time.

    PubMed

    Guo, Jingbo; Fu, Xin; Andrés Baquero, G; Sobhani, Reza; Nolasco, Daniel A; Rosso, Diego

    2016-03-15

    Over the seasonal cycles, the mean cell retention time (MCRT) of the activated sludge process is varied to compensate the wastewater temperature variations. The effects of these variations on the carbon footprint (CFP) and effluent quality index (EQI) of a conventional activated sludge (CAS) process and a nitrification/denitrification (NDN) process were quantified. The carbon emission included both biogenic and non-biogenic carbon. Carbon emissions of wasted biosolids management were also addressed. Our results confirmed that the effluent quality indicated by EQI was not necessarily improved by increasing MCRT. Higher MCRT increased the carbon emission and reduced excess sludge production, which decreased the potential for biogas energy recovery. The NDN process was preferable to the CAS process from the perspective of effluent quality. This consideration extended to the whole plant CFP if the N2O emitted during NDN was limited ([N2O]<1% [NH4(+)]removed) as the carbon emission per unit effluent quality achieved by NDN process is less than that of the CAS process. By putting forward carbon emission intensity (γ) derived from CFP and EQI, our work provides a quantitative tool for decision makers evaluating process alternatives when there is a trade-off between carbon emission and effluent quality.

  12. Absolute Abundance Measurements in Solar Flares

    NASA Astrophysics Data System (ADS)

    Warren, Harry

    2014-06-01

    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.

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

    PubMed

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

    2009-09-01

    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.

  14. The use of X-ray crystallography to determine absolute configuration.

    PubMed

    Flack, H D; Bernardinelli, G

    2008-05-15

    Essential background on the determination of absolute configuration by way of single-crystal X-ray diffraction (XRD) is presented. The use and limitations of an internal chiral reference are described. The physical model underlying the Flack parameter is explained. Absolute structure and absolute configuration are defined and their similarities and differences are highlighted. The necessary conditions on the Flack parameter for satisfactory absolute-structure determination are detailed. The symmetry and purity conditions for absolute-configuration determination are discussed. The physical basis of resonant scattering is briefly presented and the insights obtained from a complete derivation of a Bijvoet intensity ratio by way of the mean-square Friedel difference are exposed. The requirements on least-squares refinement are emphasized. The topics of right-handed axes, XRD intensity measurement, software, crystal-structure evaluation, errors in crystal structures, and compatibility of data in their relation to absolute-configuration determination are described. Characterization of the compounds and crystals by the physicochemical measurement of optical rotation, CD spectra, and enantioselective chromatography are presented. Some simple and some complex examples of absolute-configuration determination using combined XRD and CD measurements, using XRD and enantioselective chromatography, and in multiply-twinned crystals clarify the technique. The review concludes with comments on absolute-configuration determination from light-atom structures.

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

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    The 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

  16. Quantitative standards for absolute linguistic universals.

    PubMed

    Piantadosi, Steven T; Gibson, Edward

    2014-01-01

    Absolute linguistic universals are often justified by cross-linguistic analysis: If all observed languages exhibit a property, the property is taken to be a likely universal, perhaps specified in the cognitive or linguistic systems of language learners and users. In many cases, these patterns are then taken to motivate linguistic theory. Here, we show that cross-linguistic analysis will very rarely be able to statistically justify absolute, inviolable patterns in language. We formalize two statistical methods--frequentist and Bayesian--and show that in both it is possible to find strict linguistic universals, but that the numbers of independent languages necessary to do so is generally unachievable. This suggests that methods other than typological statistics are necessary to establish absolute properties of human language, and thus that many of the purported universals in linguistics have not received sufficient empirical justification.

  17. Absolute Distance Measurement with the MSTAR Sensor

    NASA Technical Reports Server (NTRS)

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

    2003-01-01

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

  18. Absolutely relative or relatively absolute: violations of value invariance in human decision making.

    PubMed

    Teodorescu, Andrei R; Moran, Rani; Usher, Marius

    2016-02-01

    Making decisions based on relative rather than absolute information processing is tied to choice optimality via the accumulation of evidence differences and to canonical neural processing via accumulation of evidence ratios. These theoretical frameworks predict invariance of decision latencies to absolute intensities that maintain differences and ratios, respectively. While information about the absolute values of the choice alternatives is not necessary for choosing the best alternative, it may nevertheless hold valuable information about the context of the decision. To test the sensitivity of human decision making to absolute values, we manipulated the intensities of brightness stimuli pairs while preserving either their differences or their ratios. Although asked to choose the brighter alternative relative to the other, participants responded faster to higher absolute values. Thus, our results provide empirical evidence for human sensitivity to task irrelevant absolute values indicating a hard-wired mechanism that precedes executive control. Computational investigations of several modelling architectures reveal two alternative accounts for this phenomenon, which combine absolute and relative processing. One account involves accumulation of differences with activation dependent processing noise and the other emerges from accumulation of absolute values subject to the temporal dynamics of lateral inhibition. The potential adaptive role of such choice mechanisms is discussed.

  19. Measurements of Absolute Abundances in Solar Flares

    NASA Astrophysics Data System (ADS)

    Warren, Harry P.

    2014-05-01

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

  20. MEASUREMENTS OF ABSOLUTE ABUNDANCES IN SOLAR FLARES

    SciTech Connect

    Warren, Harry P.

    2014-05-01

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

  1. Lens transmission measurement for an absolute radiation thermometer

    SciTech Connect

    Hao, X.; Yuan, Z.; Lu, X.

    2013-09-11

    The lens transmission for the National Institute of Metrology of China absolute radiation thermometer is measured by a hybrid method. The results of the lens transmission measurements are 99.002% and 86.792% for filter radiometers with center wavelengths 633 nm and 900 nm, respectively. These results, after correcting for diffraction factors and the size-of-source effect when the lens is incorporated within the radiometer, can be used for measurement of thermodynamic temperature. The expanded uncertainty of the lens transmission measurement system has been evaluated. It is 1.3×10{sup −3} at 633 nm and 900 nm, respectively.

  2. Quantum bath refrigeration towards absolute zero: challenging the unattainability principle.

    PubMed

    Kolář, M; Gelbwaser-Klimovsky, D; Alicki, R; Kurizki, G

    2012-08-31

    A minimal model of a quantum refrigerator, i.e., a periodically phase-flipped two-level system permanently coupled to a finite-capacity bath (cold bath) and an infinite heat dump (hot bath), is introduced and used to investigate the cooling of the cold bath towards absolute zero (T=0). Remarkably, the temperature scaling of the cold-bath cooling rate reveals that it does not vanish as T→0 for certain realistic quantized baths, e.g., phonons in strongly disordered media (fractons) or quantized spin waves in ferromagnets (magnons). This result challenges Nernst's third-law formulation known as the unattainability principle.

  3. Influence of age on the temperature of the anterior segment of the eye. Measurements by infrared thermometry.

    PubMed

    Aliò, J; Padron, M

    1982-01-01

    The absolute temperatures of five characteristic points of the orbito-ocular thermogram were studied by means of infrared thermometry in a group of 96 normal subjects, randomly selected between ages from 15 days to 80 years. Significant differences were found between older and younger age groups concerning absolute temperatures of the centre of the cornea, limbus, sclera and outer canthus. Inner canthus temperature showed very little variation with age, being the most constant thermometric point of the five selected for study. Mean absolute temperatures of the anterior segment of the eye and outer canthus measured by infrared thermometry significantly decreased with age. To the best of our knowledge this finding has not been previously reported.

  4. Absolute continuity on paths of spatial open discrete mappings

    NASA Astrophysics Data System (ADS)

    Golberg, Anatoly; Sevost'yanov, Evgeny

    2016-12-01

    We prove that open discrete mappings of Sobolev classes W_loc^{1, p}, p>n-1, with locally integrable inner dilatations admit ACP_p^{ -1} -property, which means that these mappings are absolutely continuous on almost all preimage paths with respect to p-module. In particular, our results extend the well-known Poletskiĭ lemma for quasiregular mappings. We also establish the upper bounds for p-module of such mappings in terms of integrals depending on the inner dilatations and arbitrary admissible functions.

  5. Absolute negative mobility in a one-dimensional overdamped system

    NASA Astrophysics Data System (ADS)

    Chen, Ru-Yin; Nie, Lin-Ru; Pan, Wan-Li; Zhang, Jian-Qiang

    2015-10-01

    A one-dimensional overdamped system consisting of a symmetric periodic potential, a constant bias force and a trichotomous noise was investigated. In the frame of master equations, we derived analytical expression of its current. By means of numerical calculations, the results indicate that the current first increases, then decreases and finally increases with the bias force increasing, i.e., an absolute negative mobility (ANM) phenomenon. Our further investigations presented dependence of the ANM phenomenon on parameters of the noise. Its intrinsic physical mechanism was also open up, and a minimal model with ANM phenomenon is demonstrated.

  6. New low-cost dimensionally stable composite linear absolute position encoder scale

    NASA Astrophysics Data System (ADS)

    Hassler, William L., Jr.; Nakayama, Robert K.

    1990-11-01

    A major problem in the use of standard linear position encoders is that the etched glass scales they use have a coefficient of thermal expansion (C. T. E. ) of about 1 1 . Oppm/ C. This means that their position measurements drift with changes in environmental temperature proportional to their C. T. E. . A new low cost dimensionally stable composite scale was made for use in a new absolute linear position encoder. The unidirectional Polyphenylene Sulfide/AS4 carbon fiber composite material that this scale is made of was tested for dimensional stability with respect to changes in temperature humidity and creep. The C. T. E. of the scale material was measured to be nominally 0. 29 ppm/ C with a standard deviation of 0. 12 over the operating temperature range of -2 to 62 C. The overall displacement strain due to 98 moisture absorption relative to 0 moisture absorption was measured to be 9 ppm. The strain due to stress-relief creep was found to be a maximum of 3 ppm over a period of 173 days. These results show that a linear position encoder scale made of this material is superior to those made of the standard glass currently being used and more cost effective than fused silica for most applications. 1.

  7. Comparative vs. Absolute Judgments of Trait Desirability

    ERIC Educational Resources Information Center

    Hofstee, Willem K. B.

    1970-01-01

    Reversals of trait desirability are studied. Terms indicating conservativw behavior appeared to be judged relatively desirable in comparative judgement, while traits indicating dynamic and expansive behavior benefited from absolute judgement. The reversal effect was shown to be a general one, i.e. reversals were not dependent upon the specific…

  8. New Techniques for Absolute Gravity Measurements.

    DTIC Science & Technology

    1983-01-07

    Hammond, J.A. (1978) Bollettino Di Geofisica Teorica ed Applicata Vol. XX. 8. Hammond, J. A., and Iliff, R. L. (1979) The AFGL absolute gravity system...International Gravimetric Bureau, No. L:I-43. 7. Hammond. J.A. (1978) Bollettino Di Geofisica Teorica ed Applicata Vol. XX. 8. Hammond, J.A., and

  9. An Absolute Electrometer for the Physics Laboratory

    ERIC Educational Resources Information Center

    Straulino, S.; Cartacci, A.

    2009-01-01

    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.)

  10. Stimulus Probability Effects in Absolute Identification

    ERIC Educational Resources Information Center

    Kent, Christopher; Lamberts, Koen

    2016-01-01

    This study investigated the effect of stimulus presentation probability on accuracy and response times in an absolute identification task. Three schedules of presentation were used to investigate the interaction between presentation probability and stimulus position within the set. Data from individual participants indicated strong effects of…

  11. Absolute Positioning Using the Global Positioning System

    DTIC Science & Technology

    1994-04-01

    Global Positioning System ( GPS ) has becom a useful tool In providing relativ survey...Includes the development of a low cost navigator for wheeled vehicles. ABSTRACT The Global Positioning System ( GPS ) has become a useful tool In providing...technique of absolute or point positioning involves the use of a single Global Positioning System ( GPS ) receiver to determine the three-dimenslonal

  12. Absolute rotation detection by Coriolis force measurement using optomechanics

    NASA Astrophysics Data System (ADS)

    Davuluri, Sankar; Li, Yong

    2016-10-01

    In this article, we present an application of the optomechanical cavities for absolute rotation detection. Two optomechanical cavities, one in each arm, are placed in a Michelson interferometer. The interferometer is placed on a rotating table and is moved with a uniform velocity of \\dot{\\bar{y}} with respect to the rotating table. The Coriolis force acting on the interferometer changes the length of the optomechanical cavity in one arm, while the length of the optomechanical cavity in the other arm is not changed. The phase shift corresponding to the change in the optomechanical cavity length is measured at the interferometer output to estimate the angular velocity of the absolute rotation. An analytic expression for the minimum detectable rotation rate corresponding to the standard quantum limit of measurable Coriolis force in the interferometer is derived. Squeezing technique is discussed to improve the rotation detection sensitivity by a factor of \\sqrt{{γ }m/{ω }m} at 0 K temperature, where {γ }m and {ω }m are the damping rate and angular frequency of the mechanical oscillator. The temperature dependence of the rotation detection sensitivity is studied.

  13. On determining absolute entropy without quantum theory or the third law of thermodynamics

    NASA Astrophysics Data System (ADS)

    Steane, Andrew M.

    2016-04-01

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

  14. New Experimental Method for In Situ Determination of Material Textures at Simultaneous High-Pressure and -Temperature by Means of Radial Diffraction in the Diamond Anvil Cell.

    SciTech Connect

    Liermann, H; Merkel, S; Miyagi, L; Wenk, H; Shen, G; Cynn, H; Evans, W J

    2009-07-15

    We introduce the design and capabilities of a new resistive heated diamond anvil cell that can be used for side diffraction at simultaneous high-pressure and -temperature. The device can be used to study lattice-preferred orientations in polycrystalline samples up to temperatures of 1100 K and pressures of 36 GPa. Capabilities of the instrument are demonstrated with preliminary results on the development of textures in the BCC, FCC and HCP polymorphs of iron during a non-hydrostatic compression experiment at simultaneous high-pressure and -temperature.

  15. Experimental method for in situ determination of material textures at simultaneous high pressure and high temperature by means of radial diffraction in the diamond anvil cell.

    PubMed

    Liermann, Hanns-Peter; Merkel, Sébastien; Miyagi, Lowell; Wenk, Hans-Rudolf; Shen, Guoyin; Cynn, Hyunchae; Evans, William J

    2009-10-01

    We introduce the design and capabilities of a resistive heated diamond anvil cell that can be used for side diffraction at simultaneous high pressure and high temperature. The device can be used to study lattice-preferred orientations in polycrystalline samples up to temperatures of 1100 K and pressures of 36 GPa. Capabilities of the instrument are demonstrated with preliminary results on the development of textures in the bcc, fcc, and hcp polymorphs of iron during a nonhydrostatic compression experiment at simultaneous high pressure and high temperature.

  16. Active radiometric calorimeter for absolute calibration of radioactive sources

    SciTech Connect

    Stump, K.E.; DeWerd, L.A.; Rudman, D.A.; Schima, S.A.

    2005-03-01

    This report describes the design and initial noise floor measurements of a radiometric calorimeter designed to measure therapeutic medical radioactive sources. The instrument demonstrates a noise floor of approximately 2 nW. This low noise floor is achieved by using high temperature superconducting (HTS) transition edge sensor (TES) thermometers in a temperature-control feedback loop. This feedback loop will be used to provide absolute source calibrations based upon the electrical substitution method. Other unique features of the calorimeter are (a) its ability to change sources for calibration without disrupting the vacuum of the instrument, and (b) the ability to measure the emitted power of a source in addition to the total contained source power.

  17. Absolute Position of Targets Measured Through a Chamber Window Using Lidar Metrology Systems

    NASA Technical Reports Server (NTRS)

    Kubalak, David; Hadjimichael, Theodore; Ohl, Raymond; Slotwinski, Anthony; Telfer, Randal; Hayden, Joseph

    2012-01-01

    Lidar is a useful tool for taking metrology measurements without the need for physical contact with the parts under test. Lidar instruments are aimed at a target using azimuth and elevation stages, then focus a beam of coherent, frequency modulated laser energy onto the target, such as the surface of a mechanical structure. Energy from the reflected beam is mixed with an optical reference signal that travels in a fiber path internal to the instrument, and the range to the target is calculated based on the difference in the frequency of the returned and reference signals. In cases when the parts are in extreme environments, additional steps need to be taken to separate the operator and lidar from that environment. A model has been developed that accurately reduces the lidar data to an absolute position and accounts for the three media in the testbed air, fused silica, and vacuum but the approach can be adapted for any environment or material. The accuracy of laser metrology measurements depends upon knowing the parameters of the media through which the measurement beam travels. Under normal conditions, this means knowledge of the temperature, pressure, and humidity of the air in the measurement volume. In the past, chamber windows have been used to separate the measuring device from the extreme environment within the chamber and still permit optical measurement, but, so far, only relative changes have been diagnosed. The ability to make accurate measurements through a window presents a challenge as there are a number of factors to consider. In the case of the lidar, the window will increase the time-of-flight of the laser beam causing a ranging error, and refract the direction of the beam causing angular positioning errors. In addition, differences in pressure, temperature, and humidity on each side of the window will cause slight atmospheric index changes and induce deformation and a refractive index gradient within the window. Also, since the window is a

  18. Absolute measurement of length with nanometric resolution

    NASA Astrophysics Data System (ADS)

    Apostol, D.; Garoi, F.; Timcu, A.; Damian, V.; Logofatu, P. C.; Nascov, V.

    2005-08-01

    Laser interferometer displacement measuring transducers have a well-defined traceability route to the definition of the meter. The laser interferometer is de-facto length scale for applications in micro and nano technologies. However their physical unit -half lambda is too large for nanometric resolution. Fringe interpolation-usual technique to improve the resolution-lack of reproducibility could be avoided using the principles of absolute distance measurement. Absolute distance refers to the use of interferometric techniques for determining the position of an object without the necessity of measuring continuous displacements between points. The interference pattern as produced by the interference of two point-like coherent sources is fitted to a geometric model so as to determine the longitudinal location of the target by minimizing least square errors. The longitudinal coordinate of the target was measured with accuracy better than 1 nm, for a target position range of 0.4μm.

  19. Asteroid absolute magnitudes and slope parameters

    NASA Technical Reports Server (NTRS)

    Tedesco, Edward F.

    1991-01-01

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

  20. Computer processing of spectrograms for absolute intensities.

    PubMed

    Guttman, A; Golden, J; Galbraith, H J

    1967-09-01

    A computer program was developed to process photographically recorded spectra for absolute intensity. Test and calibration films are subjected to densitometric scans that provide digitally recorded densities on magnetic tapes. The nonlinear calibration data are fitted by least-squares cubic polynomials to yield a good approximation to the monochromatic H&D curves for commonly used emulsions (2475 recording film, Royal-X, Tri-X, 4-X). Several test cases were made. Results of these cases show that the machine processed absolute intensities are accurate to within 15%o. Arbitrarily raising the sensitivity threshold by 0.1 density units above gross fog yields cubic polynomial fits to the H&D curves that are radiometrically accurate within 10%. In addition, curves of gamma vs wavelength for 2475, Tri-X, and 4-X emulsions were made. These data show slight evidence of the photographic Purkinje effect in the 2475 emulsion.

  1. An absolute measure for a key currency

    NASA Astrophysics Data System (ADS)

    Oya, Shunsuke; Aihara, Kazuyuki; Hirata, Yoshito

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

  2. Probing absolute spin polarization at the nanoscale.

    PubMed

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

    2014-12-10

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

  3. Absolute and relative dosimetry for ELIMED

    NASA Astrophysics Data System (ADS)

    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

    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.

  4. Assessment of Temperature Rise and Time of Alveolar Ridge Splitting by Means of Er:YAG Laser, Piezosurgery, and Surgical Saw: An Ex Vivo Study.

    PubMed

    Matys, Jacek; Flieger, Rafał; Dominiak, Marzena

    2016-01-01

    The most common adverse effect after bone cutting is a thermal damage. The aim of our study was to evaluate the bone temperature rise during an alveolar ridge splitting, rating the time needed to perform this procedure and the time to raise the temperature of a bone by 10°C, as well as to evaluate the bone carbonization occurrence. The research included 60 mandibles (n = 60) of adult pigs, divided into 4 groups (n = 15). Two vertical and one horizontal cut have been done in an alveolar ridge using Er:YAG laser with set power of 200 mJ (G1), 400 mJ (G2), piezosurgery unit (G3), and a saw (G4). The temperature was measured by K-type thermocouple. The highest temperature gradient was noted for piezosurgery on the buccal and lingual side of mandible. The temperature rises on the bone surface along with the increase of laser power. The lower time needed to perform ridge splitting was measured for a saw, piezosurgery, and Er:YAG laser with power of 400 mJ and 200 mJ, respectively. The temperature rise measured on the bone over 10°C and bone carbonization occurrence was not reported in all study groups. Piezosurgery, Er:YAG laser (200 mJ and 400 mJ), and surgical saw are useful and safe tools in ridge splitting surgery.

  5. Assessment of Temperature Rise and Time of Alveolar Ridge Splitting by Means of Er:YAG Laser, Piezosurgery, and Surgical Saw: An Ex Vivo Study

    PubMed Central

    Flieger, Rafał; Dominiak, Marzena

    2016-01-01

    The most common adverse effect after bone cutting is a thermal damage. The aim of our study was to evaluate the bone temperature rise during an alveolar ridge splitting, rating the time needed to perform this procedure and the time to raise the temperature of a bone by 10°C, as well as to evaluate the bone carbonization occurrence. The research included 60 mandibles (n = 60) of adult pigs, divided into 4 groups (n = 15). Two vertical and one horizontal cut have been done in an alveolar ridge using Er:YAG laser with set power of 200 mJ (G1), 400 mJ (G2), piezosurgery unit (G3), and a saw (G4). The temperature was measured by K-type thermocouple. The highest temperature gradient was noted for piezosurgery on the buccal and lingual side of mandible. The temperature rises on the bone surface along with the increase of laser power. The lower time needed to perform ridge splitting was measured for a saw, piezosurgery, and Er:YAG laser with power of 400 mJ and 200 mJ, respectively. The temperature rise measured on the bone over 10°C and bone carbonization occurrence was not reported in all study groups. Piezosurgery, Er:YAG laser (200 mJ and 400 mJ), and surgical saw are useful and safe tools in ridge splitting surgery. PMID:27957502

  6. Silicon Absolute X-Ray Detectors

    SciTech Connect

    Seely, John F.; Korde, Raj; Sprunck, Jacob; Medjoubi, Kadda; Hustache, Stephanie

    2010-06-23

    The responsivity of silicon photodiodes having no loss in the entrance window, measured using synchrotron radiation in the 1.75 to 60 keV range, was compared to the responsivity calculated using the silicon thickness measured using near-infrared light. The measured and calculated responsivities agree with an average difference of 1.3%. This enables their use as absolute x-ray detectors.

  7. Measurement of absolute gravity acceleration in Firenze

    NASA Astrophysics Data System (ADS)

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

    2011-01-01

    This paper reports the results from the accurate measurement of the acceleration of gravity g taken at two separate premises in the Polo Scientifico of the 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) μGal and (980 492 048.3 ± 3.0) μGal 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.

  8. System for absolute measurements by interferometric sensors

    NASA Astrophysics Data System (ADS)

    Norton, Douglas A.

    1993-03-01

    The most common problem of interferometric sensors is their inability to measure absolute path imbalance. Presented in this paper is a signal processing system that gives absolute, unambiguous reading of optical path difference for almost any style of interferometric sensor. Key components are a wide band (incoherent) optical source, a polychromator, and FFT electronics. Advantages include no moving parts in the signal processor, no active components at the sensor location, and the use of standard single mode fiber for sensor illumination and signal transmission. Actual absolute path imbalance of the interferometer is determined without using fringe counting or other inferential techniques. The polychromator extracts the interference information that occurs at each discrete wavelength within the spectral band of the optical source. The signal processing consists of analog and digital filtering, Fast Fourier analysis, and a peak detection and interpolation algorithm. This system was originally designed for use in a remote pressure sensing application that employed a totally passive fiber optic interferometer. A performance qualification was made using a Fabry-Perot interferometer and a commercially available laser interferometer to measure the reference displacement.

  9. Chemical composition of French mimosa absolute oil.

    PubMed

    Perriot, Rodolphe; Breme, Katharina; Meierhenrich, Uwe J; Carenini, Elise; Ferrando, Georges; Baldovini, Nicolas

    2010-02-10

    Since decades mimosa (Acacia dealbata) absolute oil has been used in the flavor and perfume industry. Today, it finds an application in over 80 perfumes, and its worldwide industrial production is estimated five tons per year. Here we report on the chemical composition of French mimosa absolute oil. Straight-chain analogues from C6 to C26 with different functional groups (hydrocarbons, esters, aldehydes, diethyl acetals, alcohols, and ketones) were identified in the volatile fraction. Most of them are long-chain molecules: (Z)-heptadec-8-ene, heptadecane, nonadecane, and palmitic acid are the most abundant, and constituents such as 2-phenethyl alcohol, methyl anisate, and ethyl palmitate are present in smaller amounts. The heavier constituents were mainly triterpenoids such as lupenone and lupeol, which were identified as two of the main components. (Z)-Heptadec-8-ene, lupenone, and lupeol were quantified by GC-MS in SIM mode using external standards and represents 6%, 20%, and 7.8% (w/w) of the absolute oil. Moreover, odorant compounds were extracted by SPME and analyzed by GC-sniffing leading to the perception of 57 odorant zones, of which 37 compounds were identified by their odorant description, mass spectrum, retention index, and injection of the reference compound.

  10. Constrained Least Absolute Deviation Neural Networks

    PubMed Central

    Wang, Zhishun; Peterson, Bradley S.

    2008-01-01

    It is well known that least absolute deviation (LAD) criterion or L1-norm used for estimation of parameters is characterized by robustness, i.e., the estimated parameters are totally resistant (insensitive) to large changes in the sampled data. This is an extremely useful feature, especially, when the sampled data are known to be contaminated by occasionally occurring outliers or by spiky noise. In our previous works, we have proposed the least absolute deviation neural network (LADNN) to solve unconstrained LAD problems. The theoretical proofs and numerical simulations have shown that the LADNN is Lyapunov-stable and it can globally converge to the exact solution to a given unconstrained LAD problem. We have also demonstrated its excellent application value in time-delay estimation. More generally, a practical LAD application problem may contain some linear constraints, such as a set of equalities and/or inequalities, which is called constrained LAD problem, whereas the unconstrained LAD can be considered as a special form of the constrained LAD. In this paper, we present a new neural network called constrained least absolute deviation neural network (CLADNN) to solve general constrained LAD problems. Theoretical proofs and numerical simulations demonstrate that the proposed CLADNN is Lyapunov stable and globally converges to the exact solution to a given constrained LAD problem, independent of initial values. The numerical simulations have also illustrated that the proposed CLADNN can be used to robustly estimate parameters for nonlinear curve fitting, which is extensively used in signal and image processing. PMID:18269958

  11. Meteorology (Temperature)

    Atmospheric Science Data Center

    2014-09-25

    Air Temperature (° C)   Daily Temperature Range (° C) Difference between the average daily maximum ... The monthly accumulation of degrees when the daily mean temperature is above 18° C.   Heating Degree Days below 18° C ...

  12. Intonational meaning.

    PubMed

    Prieto, Pilar

    2015-01-01

    Traditionally, prosodic studies have focused on the study of intonational form and the study of intonational meaning has been relatively neglected. Similarly, the fields of semantics and pragmatics have paid little attention to the pragmatic uses of intonation. As a result, there is no firm agreement within the linguistic community on how to integrate the analysis of intonational meaning across languages into a unified prosodic, semantic, and pragmatic approach. This article provides an overview of the literature on intonational meaning, describing the recent advances made in the fields of prosody, semantics/pragmatics, and syntax. Several theoretical approaches to explaining the semantics and pragmatics of intonation are presented. A common feature to most frameworks is that intonation (1) should be regarded as an integral part of linguistic grammar; and (2) typically encodes meanings related to the modal aspect of propositions. However, features such as compositionality, duality of structure, and context-dependency are still hotly debated issues. These features will be discussed from different theoretical perspectives, and we will identify potential advances related to the full integration of intonational meaning into dynamic and multidimensional models of meaning.

  13. Temperature and pressure determinations in the Venus atmosphere by means of high-resolution spectra from 1 to 2.5 microns

    NASA Technical Reports Server (NTRS)

    Dierenfeldt, K. E.; Fink, U.; Larson, H. P.

    1977-01-01

    Twenty-one bands of CO2 and the 2-0 band of CO were analyzed for best temperature and pressure fits from Venus spectra obtained with the 'Connes' interferometer at the Steward Observatory 2.25-m telescope during the spring of 1971. An average temperature of 241 plus or minus 7 K, an effective pressure of 0.12 plus or minus 0.06 atm, and an average two-way transmission abundance of 3 km-amagat were determined. No difference in temperature or pressure between hot bands, a double hot band, and regular bands was found. The results indicate that, most likely, spectroscopic line formation occurs in a relatively clear space above a scattering cloud layer with a reasonably well-defined upper boundary.

  14. Modeling the Effects of Constant and Variable Temperatures on the Vital Rates of an Age-, Stage-, and Sex-Structured Population by Means of the SANDY Approach.

    PubMed

    Nachman, G; Gotoh, T

    2015-06-01

    We present a general and flexible mathematical model (called SANDY) that can be used to describe many biological phenomena, including the phenology of arthropods. In this paper, we demonstrate how the model can be fitted to vital rates (i.e., rates associated with development, survival, hatching, and oviposition) of the two-spotted spider mite (Tetranychus urticae (Koch)) exposed to different constant temperatures ranging from 15°C to 37.5°C. SANDY was incorporated into an age-, stage- and sex-structured dynamic model, which was fitted to cohort life-tables of T. urticae conducted at five constant temperatures (15, 20, 25, 30, and 35°C). Age- and temperature-dependent vital rates for the three main stages (eggs, immatures, and adults) constituting the life-cycle of mites were adequately described by the SANDY model. The modeling approach allows for simulating the growth of a population in a variable environment. We compared the predicted net reproductive rate (R0) and intrinsic rate of natural increase (rm) at fluctuating temperatures with empirical values obtained from life-table experiments conducted at temperatures that changed with a daily amplitude (±0, ±3, ±6, ±9, and ±12°C) around an average of 22°C. Results show that R0 decreases with increasing amplitude, while rm is more robust to variable temperatures. An advantage of SANDY is that the same simple mathematical expression can be applied to describe all the vital rates. Besides, the approach is not confined to modeling the influence of a single factor on population growth but allows for incorporating the combined effect of several limiting factors, provided that the combined effect of the factors is multiplicative.

  15. Relationship between mean body temperature calculated by two- or three-compartment models and active cutaneous vasodilation in humans: a comparison between cool and warm environments during leg exercise

    NASA Astrophysics Data System (ADS)

    Demachi, Koichi; Yoshida, Tetsuya; Tsuneoka, Hideyuki

    2012-03-01

    The aim of this study was to assess whether the three-compartment model of mean body temperature (Tb3) calculated from the esophageal temperature (Tes), temperature in deep tissue of exercising muscle (Tdt), and mean skin temperature (Tsk) has the potential to provide a better match with the thermoregulatory responses than the two-component model of mean body temperature (Tb2) calculated from Tes and Tsk. Seven male subjects performed 40 min of a prolonged cycling exercise at 30% maximal oxygen uptake at 21°C or 31°C (50% relative humidity). Throughout the experiment, Tsk, Tb2, Tb3, and Tdt were significantly ( P < 0.01) lower at 21°C than at 31°C temperature conditions, while Tes was similar under both conditions. During exercise, an increase in cutaneous vascular conductance (skin blood flow / mean arterial pressure) over the chest (%CVCc) was observed at both 21°C and 31°C, while no increase was observed at the forearm at 21°C. Furthermore, the Tb3 and Tdt threshold for the onset of the increase in %CVCc was similar, but the Tes and Tb2 threshold differed significantly ( P < 0.05) between the conditions tested. These results suggest that active cutaneous vasodilation at the chest is related more closely to Tb3 or Tdt than that measured by Tes or Tb2 calculated by Tes and Tsk during exercise at both 21°C and 31°C.

  16. Study of the dielectric properties of weathered granite, basalt and quartzite by means of broadband dielectric spectroscopy over a wide range of frequency and temperature.

    NASA Astrophysics Data System (ADS)

    Araujo, Steven; Delbreilh, Laurent; Antoine, Raphael; Dargent, Eric; Fauchard, Cyrille

    2016-04-01

    Broadband Dielectric Spectroscopy (BDS) allows the measurement of the complex impedance of various materials over a wide range of frequency (0.1 Hz to 2 MHz) and temperature (-150 to 400°C). Other properties can be assessed from this measurement such as permittivity and conductivity. In this study, the BDS is presented to figure out the complex behaviour of several rock parameters as a function of the temperature and frequency. Indeed, multiple processes might occur such as interfacial polarization, AC and DC conductivity. The measurements of a weathered granite, basalt and quartzite were performed. The activation energy associated to each process involved during the measurement can be calculated by following the relaxation time as a function of the temperature, taking into account the Havriliak-Négami model. The principle of the technique and the whole study is presented here and several hypothesis are advanced to explain the dielectric behaviour of rocks. Finally, as the range of frequency and temperature of the BDS method is common to several electromagnetic and electrical techniques applied in subsurface geophysics, some perspectives are proposed to better understand geophysical measurements in hydrothermal systems.

  17. A RESEARCH PLAN FOR THE USE OF THERMAL AVHRR IMAGERY TO STUDY ANNUAL AND SEASONAL MEAN SURFACE TEMPERATURES FOR LARGE LAKES IN NORTH AMERICA

    EPA Science Inventory

    Surface and vertical temperature data will be obtained from several large lakes With surface areas large enough to be effectively sampled with AVHRR imagery. Yearly and seasonal patterns of surface and whole water column thermal values will be compared to estimates of surface tem...

  18. Crowdsourcing urban air temperatures from smartphone battery temperatures

    NASA Astrophysics Data System (ADS)

    Overeem, Aart; Robinson, James C. R.; Leijnse, Hidde; Steeneveld, Gert-Jan; Horn, Berthold K. P.; Uijlenhoet, Remko

    2014-05-01

    Accurate air temperature observations in urban areas are important for meteorology and energy demand planning. They are indispensable to study the urban heat island effect and the adverse effects of high temperatures on human health. However, the availability of temperature observations in cities is often limited. Here we show that relatively accurate air temperature information for the urban canopy layer can be obtained from an alternative, nowadays omnipresent source: smartphones. In this study, battery temperatures were collected by an Android application for smartphones. It has been shown that a straightforward heat transfer model can be employed to estimate daily mean air temperatures from smartphone battery temperatures for eight major cities around the world. The results demonstrate the enormous potential of this crowdsourcing application for real-time temperature monitoring in densely populated areas. Battery temperature data were collected by users of an Android application for cell phones (opensignal.com). The application automatically sends battery temperature data to a server for storage. In this study, battery temperatures are averaged in space and time to obtain daily averaged battery temperatures for each city separately. A regression model, which can be related to a physical model, is employed to retrieve daily air temperatures from battery temperatures. The model is calibrated with observed air temperatures from a meteorological station of an airport located in or near the city. Time series of air temperatures are obtained for each city for a period of several months, where 50% of the data is for independent verification. The methodology has been applied to Buenos Aires, London, Los Angeles, Paris, Mexico City, Moscow, Rome, and Sao Paulo. The evolution of the retrieved air temperatures often correspond well with the observed ones. The mean absolute error of daily air temperatures is less than 2 degrees Celsius, and the bias is within 1 degree

  19. Adsorption mechanisms and effect of temperature in reversed-phase liquid chromatography-Meaning of the classical Van't Hoff plot in chromatography

    SciTech Connect

    Gritti, Fabrice; Guiochon, Georges A

    2006-07-01

    The effect of temperature on the adsorption and retention behaviors of a low molecular weight compound (phenol) on a C{sub 18}-bonded silica column (C{sub 18}-Sunfire, Waters) from aqueous solutions of methanol (20%) or acetonitrile (15%) was investigated. The results of the measurements were interpreted successively on the basis of the linear (i.e., overall retention factors) and the nonlinear (i.e., adsorption isotherms, surface heterogeneity, saturation capacities, and equilibrium constants) chromatographic methods. The confrontation of these two approaches confirmed the impossibility of a sound physical interpretation of the conventional Van't Hoff plot. The classical linear chromatography theory assumes that retention is determined by the equilibrium thermodynamics of analytes between a homogeneous stationary phase and a homogeneous mobile phase (although there may be two or several types of interactions). From values of the experimental retention factors in a temperature interval and estimates of the activity coefficients at infinite dilution in the same temperature interval provided by the UNIFAC group contribution method, evidence is provided that such a retention model cannot hold. The classical Van't Hoff plot appears meaningless and its linear behavior a mere accident. Results from nonlinear chromatography confirm these conclusions and provide explanations. The retention factors seem to fulfill the Van't Hoff equation, not the Henry constants corresponding to the different types of adsorption sites. The saturation capacities and the adsorption energies are clearly temperature dependent. The temperature dependence of these characteristics of the different assorption sites are different in aqueous methanol and acetonitrile solutions.

  20. Communication: The absolute shielding scales of oxygen and sulfur revisited

    NASA Astrophysics Data System (ADS)

    Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Ruud, Kenneth; Gauss, Jürgen

    2015-03-01

    We present an updated semi-experimental absolute shielding scale for the 17O and 33S nuclei. These new shielding scales are based on accurate rotational microwave data for the spin-rotation constants of H217O [Puzzarini et al., J. Chem. Phys. 131, 234304 (2009)], C17O [Cazzoli et al., Phys. Chem. Chem. Phys. 4, 3575 (2002)], and H233S [Helgaker et al., J. Chem. Phys. 139, 244308 (2013)] corrected both for vibrational and temperature effects estimated at the CCSD(T) level of theory as well as for the relativistic corrections to the relation between the spin-rotation constant and the absolute shielding constant. Our best estimate for the oxygen shielding constants of H217O is 328.4(3) ppm and for C17O -59.05(59) ppm. The relativistic correction for the sulfur shielding of H233S amounts to 3.3%, and the new sulfur shielding constant for this molecule is 742.9(4.6) ppm.

  1. Absolute Measurements of Radiation Damage in Nanometer Thick Films

    PubMed Central

    Alizadeh, Elahe; Sanche, Léon

    2013-01-01

    We address the problem of absolute measurements of radiation damage in films of nanometer thicknesses. Thin films of DNA (~ 2–160nm) are deposited onto glass substrates and irradiated with varying doses of 1.5 keV X-rays under dry N2 at atmospheric pressure and room temperature. For each different thickness, the damage is assessed by measuring the loss of the supercoiled configuration as a function of incident photon fluence. From the exposure curves, the G-values are deduced, assuming that X-ray photons interacting with DNA, deposit all of their energy in the film. The results show that the G-value (i.e., damage per unit of deposited energy) increases with film thickness and reaches a plateau at 30±5 nm. This thickness dependence provides a correction factor to estimate the actual G-value for films with thicknesses below 30nm thickness. Thus, the absolute values of damage can be compared with that of films of any thickness under different experimental conditions. PMID:22562941

  2. Communication: The absolute shielding scales of oxygen and sulfur revisited.

    PubMed

    Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Ruud, Kenneth; Gauss, Jürgen

    2015-03-07

    We present an updated semi-experimental absolute shielding scale for the (17)O and (33)S nuclei. These new shielding scales are based on accurate rotational microwave data for the spin-rotation constants of H2(17)O [Puzzarini et al., J. Chem. Phys. 131, 234304 (2009)], C(17)O [Cazzoli et al., Phys. Chem. Chem. Phys. 4, 3575 (2002)], and H2(33)S [Helgaker et al., J. Chem. Phys. 139, 244308 (2013)] corrected both for vibrational and temperature effects estimated at the CCSD(T) level of theory as well as for the relativistic corrections to the relation between the spin-rotation constant and the absolute shielding constant. Our best estimate for the oxygen shielding constants of H2(17)O is 328.4(3) ppm and for C(17)O -59.05(59) ppm. The relativistic correction for the sulfur shielding of H2(33)S amounts to 3.3%, and the new sulfur shielding constant for this molecule is 742.9(4.6) ppm.

  3. Communication: The absolute shielding scales of oxygen and sulfur revisited

    SciTech Connect

    Komorovsky, Stanislav; Repisky, Michal; Malkin, Elena; Ruud, Kenneth; Gauss, Jürgen

    2015-03-07

    We present an updated semi-experimental absolute shielding scale for the {sup 17}O and {sup 33}S nuclei. These new shielding scales are based on accurate rotational microwave data for the spin–rotation constants of H{sub 2}{sup 17}O [Puzzarini et al., J. Chem. Phys. 131, 234304 (2009)], C{sup 17}O [Cazzoli et al., Phys. Chem. Chem. Phys. 4, 3575 (2002)], and H{sub 2}{sup 33}S [Helgaker et al., J. Chem. Phys. 139, 244308 (2013)] corrected both for vibrational and temperature effects estimated at the CCSD(T) level of theory as well as for the relativistic corrections to the relation between the spin–rotation constant and the absolute shielding constant. Our best estimate for the oxygen shielding constants of H{sub 2}{sup 17}O is 328.4(3) ppm and for C{sup 17}O −59.05(59) ppm. The relativistic correction for the sulfur shielding of H{sub 2}{sup 33}S amounts to 3.3%, and the new sulfur shielding constant for this molecule is 742.9(4.6) ppm.

  4. The study of absolute distance measurement based on the self-mixing interference in laser diode

    NASA Astrophysics Data System (ADS)

    Wang, Ting-ting; Zhang, Chuang

    2009-07-01

    In this work, an absolute distance measurement method based on the self-mixing interference is presented. The principles of the method used three-mirror cavity equivalent model are studied in this paper, and the mathematical model is given. Wavelength modulation of the laser beam is obtained by saw-tooth modulating the infection current of the laser diode. Absolute distance of the external target is determined by Fourier analysis method. The frequency of signal from PD is linearly dependent on absolute distance, but also affected by temperature and fluctuation of current source. A dual-path method which uses the reference technique for absolute distance measurement has been proposed. The theoretical analysis shows that the method can eliminate errors resulting from distance-independent variations in the setup. Accuracy and stability can be improved. Simulated results show that a resolution of +/-0.2mm can be achieved for absolute distance ranging from 250mm to 500mm. In the same measurement range, the resolution we obtained is better than other absolute distance measurement system proposed base on self-mixing interference.

  5. Clock time is absolute and universal

    NASA Astrophysics Data System (ADS)

    Shen, Xinhang

    2015-09-01

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

  6. Absolute Radiometric Calibration of EUNIS-06

    NASA Technical Reports Server (NTRS)

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

    2007-01-01

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

  7. Error analysis in newborn screening: can quotients support the absolute values?

    PubMed

    Arneth, Borros; Hintz, Martin

    2017-03-01

    Newborn screening is performed using modern tandem mass spectrometry, which can simultaneously detect a variety of analytes, including several amino acids and fatty acids. Tandem mass spectrometry measures the diagnostic parameters as absolute concentrations and produces fragments which are used as markers of specific substances. Several prominent quotients can also be derived, which are quotients of two absolute measured concentrations. In this study, we determined the precision of both the absolute concentrations and the derived quotients. First, the measurement error of the absolute concentrations and the measurement error of the ratios were practically determined. Then, the Gaussian theory of error calculation was used. Finally, these errors were compared with one another. The practical analytical accuracies of the quotients were significantly higher (e.g., coefficient of variation (CV) = 5.1% for the phenylalanine to tyrosine (Phe/Tyr) quotient and CV = 5.6% for the Fisher quotient) than the accuracies of the absolute measured concentrations (mean CVs = 12%). According to our results, the ratios are analytically correct and, from an analytical point of view, can support the absolute values in finding the correct diagnosis.

  8. Brownian motion: Absolute negative particle mobility

    NASA Astrophysics Data System (ADS)

    Ros, Alexandra; Eichhorn, Ralf; Regtmeier, Jan; Duong, Thanh Tu; Reimann, Peter; Anselmetti, Dario

    2005-08-01

    Noise effects in technological applications, far from being a nuisance, can be exploited with advantage - for example, unavoidable thermal fluctuations have found application in the transport and sorting of colloidal particles and biomolecules. Here we use a microfluidic system to demonstrate a paradoxical migration mechanism in which particles always move in a direction opposite to the net acting force (`absolute negative mobility') as a result of an interplay between thermal noise, a periodic and symmetric microstructure, and a biased alternating-current electric field. This counterintuitive phenomenon could be used for bioanalytical purposes, for example in the separation and fractionation of colloids, biological molecules and cells.

  9. Absolute quantification of myocardial blood flow.

    PubMed

    Yoshinaga, Keiichiro; Manabe, Osamu; Tamaki, Nagara

    2016-07-21

    With the increasing availability of positron emission tomography (PET) myocardial perfusion imaging, the absolute quantification of myocardial blood flow (MBF) has become popular in clinical settings. Quantitative MBF provides an important additional diagnostic or prognostic information over conventional visual assessment. The success of MBF quantification using PET/computed tomography (CT) has increased the demand for this quantitative diagnostic approach to be more accessible. In this regard, MBF quantification approaches have been developed using several other diagnostic imaging modalities including single-photon emission computed tomography, CT, and cardiac magnetic resonance. This review will address the clinical aspects of PET MBF quantification and the new approaches to MBF quantification.

  10. An absolute radius scale for Saturn's rings

    NASA Technical Reports Server (NTRS)

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

    1990-01-01

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

  11. Absolute Rate Theories of Epigenetic Stability

    NASA Astrophysics Data System (ADS)

    Walczak, Aleksandra M.; Onuchic, Jose N.; Wolynes, Peter G.

    2006-03-01

    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, depend on the rates of DNA binding and unbinding events and on the rates of protein synthesis and degradation. Different mechanisms of escape from the stable attractors occur in the nonadiabatic, weakly adiabatic and strictly adiabatic regimes, characterized by the relative values of those input rates.

  12. Absolute rate theories of epigenetic stability

    NASA Astrophysics Data System (ADS)

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

    2005-12-01

    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 depend on the rates of DNA binding and unbinding events and on the rates of protein synthesis and degradation. Different mechanisms of escape from the stable attractors occur in the nonadiabatic, weakly adiabatic, and strictly adiabatic regimes, characterized by the relative values of those input rates. rate theory | stochastic gene expression | gene switches

  13. Absolute method of measuring magnetic susceptibility

    USGS Publications Warehouse

    Thorpe, A.; Senftle, F.E.

    1959-01-01

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

  14. Absolute Priority for a Vehicle in VANET

    NASA Astrophysics Data System (ADS)

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

    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.

  15. The Mesospheric OH* layer above Spitsbergen: Investigation of polar mesospheric dynamics and temperature trends by means of ground based OH* airglow measurements and model studies

    NASA Astrophysics Data System (ADS)

    Kowalewski, S.; Palm, M.; Notholt, J.

    2012-04-01

    The hydroxyl (OH*) emission layer is one of the dominant features of the mesopause region. It is primarily formed via the reaction of ozone and atomic hydrogen, which results in vibrationally excited OH* radicals. Due to radiative deexcitation, these radicals contribute to the airglow, which we can observe at different emission bands. For low excitation levels (ν≤6) of OH*, its lifetime can be sufficient to become thermalized by collision with the surrounding molecules, hence its emission can serve as a measure of ambient temperature. Because of the remoteness of the mesosphere, this offers a valuable source of information on mesospheric temperatures. While satellite based observations of the OH* layer offer comprehensive data sets on global scales, the spatial as well as the temporal resolution is limited by the corresponding orbits. Ground based measurements can fill this gap and enable us to study mesospheric disturbances at shorter time scales. Particularly the polar mesospheric region can be subject to large variability, which becomes apparent in the brightness and temperature signals from the OH* emission layer. In this poster we present temperatures derived from measurements taken from a Fourier Transform Spectrometer (FTS), which is located at the AWIPEV Arctic Research Base in Ny-Ålesund, Spitsbergen (79°). Measurements are available since 2007 and cover various emission bands of OH* in the spectral region from 5900 cm^-1 to 6500 cm^-1. We illustrate large scale polar mesospheric warming events, which have a striking impact on mesospheric dynamics and the coupling to the lower atmosphere. In addition to satellite based observations that we compare with our data, we illustrate the ability of our instrument to resolve short term perturbations. We discuss how we will combine these observations to model studies, in order to shed more light on the associated polar mesospheric dynamics in an upcoming analyis.

  16. Characterization and potential of three temperature ranges for hydrogen fermentation of cellulose by means of activity test and 16s rRNA sequence analysis.

    PubMed

    Gadow, Samir I; Jiang, Hongyu; Li, Yu-You

    2016-06-01

    A series of standardized activity experiments were performed to characterize three different temperature ranges of hydrogen fermentation from different carbon sources. 16S rRNA sequences analysis showed that the bacteria were close to Enterobacter genus in the mesophilic mixed culture (MMC) and Thermoanaerobacterium genus in the thermophilic and hyper-thermophilic mixed cultures (TMC and HMC). The MMC was able to utilize the glucose and cellulose to produce methane gas within a temperature range between 25 and 45 °C and hydrogen gas from 35 to 60°C. While, the TMC and HMC produced only hydrogen gas at all temperature ranges and the highest activity of 521.4mlH2/gVSSd was obtained by TMC. The thermodynamic analysis showed that more energy is consumed by hydrogen production from cellulose than from glucose. The experimental results could help to improve the economic feasibility of cellulosic biomass energy using three-phase technology to produce hythane.

  17. The effect of the replacement of forests by agricutural land on mean and extreme temperature in temperate regions from 1850 to present

    NASA Astrophysics Data System (ADS)

    Lejeune, Quentin; Davin, Edouard; Seneviratne, Sonia

    2015-04-01

    During the industrial period, the extent of forest was reduced in favour of the expansion of agriculture in most temperate regions. This has impacted local climate conditions by modifying the physical properties of the land surface such as albedo and evapotranspiration rate. Previous modelling studies suggest that these historical land-use and land-cover changes (LULCC) have had a cooling effect annually, in some regions of a similar magnitude as the temperature changes driven by increasing greenhouse gas (GHG) concentrations, but with large differences in the magnitude and the seasonal pattern of the temperature response among models [1,2]. These studies were however limited to seven GCMs, and the considered simulations were run with global non-coupled models using fixed Sea Surface Temperatures (SSTs). Here, our goal is to reassess these findings using a larger number of fully coupled historical simulations from the Coupled Model Intercomparison Project phase 5 (CMIP5). We include only CMIP5 models providing at least three ensemble members, in order to take interannual variability into account. These historical simulations were driven by both natural (volcanoes) and anthropogenic forcings (GHG, land-use, aerosols). In order to disentangle the effect of LULCC from that of other forcings, we compared climate changes in neighbouring grid cells in which surface temperature is assumed to respond similarly to GHG and other large-scale forcings, but which differ in terms of land-use forcing. Our analysis confirms that the expansion of agriculture at the expense of forests lead to a local cooling in winter, with nine models out of 11 indicating such a behaviour, and it also suggests that this response was primarily driven by albedo changes. However, the results reveal a higher model disagreement than what was previously found regarding the impact on summer temperature changes, with five models out of 11 showing a warming effect of LULCC, against only one out of seven in

  18. How Mean is the Mean?

    PubMed Central

    Speelman, Craig P.; McGann, Marek

    2013-01-01

    In this paper we voice concerns about the uncritical manner in which the mean is often used as a summary statistic in psychological research. We identify a number of implicit assumptions underlying the use of the mean and argue that the fragility of these assumptions should be more carefully considered. We examine some of the ways in which the potential violation of these assumptions can lead us into significant theoretical and methodological error. Illustrations of alternative models of research already extant within Psychology are used to explore methods of research less mean-dependent and suggest that a critical assessment of the assumptions underlying its use in research play a more explicit role in the process of study design and review. PMID:23888147

  19. Absolute Spectrophotometry of 237 Open Cluster Stars

    NASA Astrophysics Data System (ADS)

    Clampitt, L.; Burstein, D.

    1994-12-01

    We present absolute spectrophotometry of 237 stars in 7 nearby open clusters: Hyades, Pleiades, Alpha Persei, Praesepe, Coma Berenices, IC 4665, and M 39. The observations were taken using the Wampler single-channel scanner (Wampler 1966) on the Crossley 0.9m telescope at Lick Observatory from July 1973 through December 1974. 21 bandpasses spanning the spectral range 3500 Angstroms to 7780 Angstroms were observed for each star, with bandwiths ranging from 32Angstroms to 64 Angstroms. Data are standardized to the Hayes--Latham (1975) system. Our measurements are compared to filter colors on the Johnson BV, Stromgren ubvy, and Geneva U V B_1 B_2 V_1 G systems, as well as to spectrophotometry of a few stars published by Gunn, Stryker & Tinsley and in the Spectrophotometric Standards Catalog (Adelman; as distributed by the NSSDC). Both internal and external comparisons to the filter systems indicate a formal statistical accuracy per bandpass of 0.01 to 0.02 mag, with apparent larger ( ~ 0.03 mag) differences in absolute calibration between this data set and existing spectrophotometry. These data will comprise part of the spectrophotometry that will be used to calibrate the Beijing-Arizona-Taipei-Connecticut Color Survey of the Sky (see separate paper by Burstein et al. at this meeting).

  20. Linear ultrasonic motor for absolute gravimeter.

    PubMed

    Jian, Yue; Yao, Zhiyuan; Silberschmidt, Vadim V

    2017-02-01

    Thanks to their compactness and suitability for vacuum applications, linear ultrasonic motors are considered as substitutes for classical electromagnetic motors as driving elements in absolute gravimeters. Still, their application is prevented by relatively low power output. To overcome this limitation and provide better stability, a V-type linear ultrasonic motor with a new clamping method is proposed for a gravimeter. In this paper, a mechanical model of stators with flexible clamping components is suggested, according to a design criterion for clamps of linear ultrasonic motors. After that, an effect of tangential and normal rigidity of the clamping components on mechanical output is studied. It is followed by discussion of a new clamping method with sufficient tangential rigidity and a capability to facilitate pre-load. Additionally, a prototype of the motor with the proposed clamping method was fabricated and the performance tests in vertical direction were implemented. Experimental results show that the suggested motor has structural stability and high dynamic performance, such as no-load speed of 1.4m/s and maximal thrust of 43N, meeting the requirements for absolute gravimeters.

  1. Why to compare absolute numbers of mitochondria.

    PubMed

    Schmitt, Sabine; Schulz, Sabine; Schropp, Eva-Maria; Eberhagen, Carola; Simmons, Alisha; Beisker, Wolfgang; Aichler, Michaela; Zischka, Hans

    2014-11-01

    Prompted by pronounced structural differences between rat liver and rat hepatocellular carcinoma mitochondria, we suspected these mitochondrial populations to differ massively in their molecular composition. Aiming to reveal these mitochondrial differences, we came across the issue on how to normalize such comparisons and decided to focus on the absolute number of mitochondria. To this end, fluorescently stained mitochondria were quantified by flow cytometry. For rat liver mitochondria, this approach resulted in mitochondrial protein contents comparable to earlier reports using alternative methods. We determined similar protein contents for rat liver, heart and kidney mitochondria. In contrast, however, lower protein contents were determined for rat brain mitochondria and for mitochondria from the rat hepatocellular carcinoma cell line McA 7777. This result challenges mitochondrial comparisons that rely on equal protein amounts as a typical normalization method. Exemplarily, we therefore compared the activity and susceptibility toward inhibition of complex II of rat liver and hepatocellular carcinoma mitochondria and obtained significant discrepancies by either normalizing to protein amount or to absolute mitochondrial number. Importantly, the latter normalization, in contrast to the former, demonstrated a lower complex II activity and higher susceptibility toward inhibition in hepatocellular carcinoma mitochondria compared to liver mitochondria. These findings demonstrate that solely normalizing to protein amount may obscure essential molecular differences between mitochondrial populations.

  2. The absolute threshold of cone vision

    PubMed Central

    Koeing, Darran; Hofer, Heidi

    2013-01-01

    We report measurements of the absolute threshold of cone vision, which has been previously underestimated due to sub-optimal 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 msec), 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 units 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

  3. [Estimation of absolute risk for fracture].

    PubMed

    Fujiwara, Saeko

    2009-03-01

    Osteoporosis treatment aims to prevent fractures and maintain the QOL of the elderly. However, persons at high risk of future fracture cannot be effectively identified on the basis of bone density (BMD) alone, although BMD is used as an diagnostic criterion. Therefore, the WHO recommended that absolute risk for fracture (10-year probability of fracture) for each individual be evaluated and used as an index for intervention threshold. The 10-year probability of fracture is calculated based on age, sex, BMD at the femoral neck (body mass index if BMD is not available), history of previous fractures, parental hip fracture history, smoking, steroid use, rheumatoid arthritis, secondary osteoporosis and alcohol consumption. The WHO has just announced the development of a calculation tool (FRAX: WHO Fracture Risk Assessment Tool) in February this year. Fractures could be prevented more effectively if, based on each country's medical circumstances, an absolute risk value for fracture to determine when to start medical treatment is established and persons at high risk of fracture are identified and treated accordingly.

  4. Absolute stereochemistry of altersolanol A and alterporriols.

    PubMed

    Kanamaru, Saki; Honma, Miho; Murakami, Takanori; Tsushima, Taro; Kudo, Shinji; Tanaka, Kazuaki; Nihei, Ken-Ichi; Nehira, Tatsuo; Hashimoto, Masaru

    2012-02-01

    The absolute stereochemistry of altersolanol A (1) was established by observing a positive exciton couplet in the circular dichroism (CD) spectrum of the C3,C4-O-bis(2-naphthoyl) derivative 10 and by chemical correlations with known compound 8. Before the discussion, the relative stereochemistry of 1 was confirmed by X-ray crystallographic analysis. The shielding effect at C7'-OMe group by C1-O-benzoylation established the relative stereochemical relationship between the C8-C8' axial bonding and the C1-C4/C1'-C4' polyol moieties of alterporriols E (3), an atropisomer of the C8-C8' dimer of 1. As 3 could be obtained by dimerization of 1 in vitro, the absolute configuration of its central chirality elements (C1-C4) must be identical to those of 1. Spectral comparison between the experimental and theoretical CD spectra supported the above conclusion. Axial stereochemistry of novel C4-O-deoxy dimeric derivatives, alterporriols F (4) and G (5), were also revealed by comparison of their CD spectra to those of 2 and 3.

  5. Absolute Electron Extraction Efficiency of Liquid Xenon

    NASA Astrophysics Data System (ADS)

    Kamdin, Katayun; Mizrachi, Eli; Morad, James; Sorensen, Peter

    2016-03-01

    Dual phase liquid/gas xenon time projection chambers (TPCs) currently set the world's most sensitive limits on weakly interacting massive particles (WIMPs), a favored dark matter candidate. These detectors rely on extracting electrons from liquid xenon into gaseous xenon, where they produce proportional scintillation. The proportional scintillation from the extracted electrons serves to internally amplify the WIMP signal; even a single extracted electron is detectable. Credible dark matter searches can proceed with electron extraction efficiency (EEE) lower than 100%. However, electrons systematically left at the liquid/gas boundary are a concern. Possible effects include spontaneous single or multi-electron proportional scintillation signals in the gas, or charging of the liquid/gas interface or detector materials. Understanding EEE is consequently a serious concern for this class of rare event search detectors. Previous EEE measurements have mostly been relative, not absolute, assuming efficiency plateaus at 100%. I will present an absolute EEE measurement with a small liquid/gas xenon TPC test bed located at Lawrence Berkeley National Laboratory.

  6. Standardization of the cumulative absolute velocity

    SciTech Connect

    O'Hara, T.F.; Jacobson, J.P. )

    1991-12-01

    EPRI NP-5930, A Criterion for Determining Exceedance of the Operating Basis Earthquake,'' was published in July 1988. As defined in that report, the Operating Basis Earthquake (OBE) is exceeded when both a response spectrum parameter and a second damage parameter, referred to as the Cumulative Absolute Velocity (CAV), are exceeded. In the review process of the above report, it was noted that the calculation of CAV could be confounded by time history records of long duration containing low (nondamaging) acceleration. Therefore, it is necessary to standardize the method of calculating CAV to account for record length. This standardized methodology allows consistent comparisons between future CAV calculations and the adjusted CAV threshold value based upon applying the standardized methodology to the data set presented in EPRI NP-5930. The recommended method to standardize the CAV calculation is to window its calculation on a second-by-second basis for a given time history. If the absolute acceleration exceeds 0.025g at any time during each one second interval, the earthquake records used in EPRI NP-5930 have been reanalyzed and the adjusted threshold of damage for CAV was found to be 0.16g-set.

  7. Swarm's Absolute Scalar Magnetometers Burst Mode Results

    NASA Astrophysics Data System (ADS)

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

    2014-12-01

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

  8. Absolute bioavailability and absorption characteristics of divalproex sodium extended-release tablets in healthy volunteers.

    PubMed

    Dutta, Sandeep; Reed, Ronald C; Cavanaugh, John H

    2004-07-01

    Conventional delayed-release, enteric-coated divalproex sodium tablet has an absolute bioavailability of approximately 100%. Divalproex sodium extended-release (ER) tablet is a novel formulation of valproic acid (VPA) designed to release the drug slowly at a constant zero-order rate. The purpose of this study was to evaluate the absolute bioavailability and absorption characteristics of divalproex ER. Healthy adult volunteers (n = 16) received divalproex ER and intravenous VPA in crossover fashion. Absolute bioavailability was calculated as the divalproex ER/intravenous VPA ratio of area under the curve extrapolated to infinity. The duration and rate of absorption of VPA from divalproex ER tablets were determined by deconvolution analysis. The geometric mean absolute bioavailability of divalproex ER was 0.896. The mean (coefficient of variation) duration of drug absorption from divalproex ER was 21.8 (17%) hours, and the zero-order absorption rate was 21.6 (24%) mg/h for a 500-mg tablet. Divalproex ER has a lower absolute bioavailability than conventional divalproex tablets but exhibits good extended-release characteristics without any dose dumping.

  9. Evaluation of trends in some temperature series at some Italian stations and their modelling by means of spectral methods: first results in the Latium coastal area

    NASA Astrophysics Data System (ADS)

    Beltrano, M. C.; Testa, O.; Malvestuto, V.; Esposito, S.

    2010-09-01

    The investigation of the presence of signals indicating possible climatic changes in progress during the second half of the last century in the coastal area of the central Tyrrhenian sea has been carried out within the context of a research programme promoted by the Italian Science Academy (alias "the Academy of the XL") and financed by the Presidential Bureau. Our goal has been a better understanding of the behaviour of the minimum and maximum temperature variations in the period 1951-1999 and the modelling of their stochastic residuals through spectral analysis and the optimized construction of suitable autoregressive one-parameter processes. The meteorological data source for this research was the Italian "Agrometeorological National DataBase" (BDAN) of the Agrometeorological Informatics National System (SIAN). The spectral and stochastic analysis of meteorological data usually require full data sets without gaps, but, in BDAN, numerous data sets taken at stations located in the investigated area were incomplete. Thus, after the selection of an adequate number of stations, both representative of the region under study and characterized by a low number of data gaps, the first step was to fill all the gaps in the daily series using specific statistical techniques. After this preliminary treatment, we were left with seven temperature series that showed enough good characteristics in order to carry out an efficient modelling. Spectral analysis of minimum and maximum temperature series permitted to identify an auto-regressive one-parameter model well representing the stochastic residual of each series. With the aid of the complete model, consisting of a deterministic component (a linear trend plus two seasonal oscillations) and a stochastic residual, one can satisfactorily reconstruct the data in the past (climatic historical analysis) and to try a prediction of future values (forecasting). Thus the proposed model appears to represent a valid method to evaluate the

  10. A three-axis SQUID-based absolute vector magnetometer.

    PubMed

    Schönau, T; Zakosarenko, V; Schmelz, M; Stolz, R; Anders, S; Linzen, S; Meyer, M; Meyer, H-G

    2015-10-01

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth's magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz(1/2). The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  11. Absolute Radiation Measurements in Earth and Mars Entry Conditions

    NASA Technical Reports Server (NTRS)

    Cruden, Brett A.

    2014-01-01

    This paper reports on the measurement of radiative heating for shock heated flows which simulate conditions for Mars and Earth entries. Radiation measurements are made in NASA Ames' Electric Arc Shock Tube at velocities from 3-15 km/s in mixtures of N2/O2 and CO2/N2/Ar. The technique and limitations of the measurement are summarized in some detail. The absolute measurements will be discussed in regards to spectral features, radiative magnitude and spatiotemporal trends. Via analysis of spectra it is possible to extract properties such as electron density, and rotational, vibrational and electronic temperatures. Relaxation behind the shock is analyzed to determine how these properties relax to equilibrium and are used to validate and refine kinetic models. It is found that, for some conditions, some of these values diverge from non-equilibrium indicating a lack of similarity between the shock tube and free flight conditions. Possible reasons for this are discussed.

  12. A three-axis SQUID-based absolute vector magnetometer

    SciTech Connect

    Schönau, T.; Schmelz, M.; Stolz, R.; Anders, S.; Linzen, S.; Meyer, H.-G.; Zakosarenko, V.; Meyer, M.

    2015-10-15

    We report on the development of a three-axis absolute vector magnetometer suited for mobile operation in the Earth’s magnetic field. It is based on low critical temperature dc superconducting quantum interference devices (LTS dc SQUIDs) with sub-micrometer sized cross-type Josephson junctions and exhibits a white noise level of about 10 fT/Hz{sup 1/2}. The width of superconducting strip lines is restricted to less than 6 μm in order to avoid flux trapping during cool-down in magnetically unshielded environment. The long-term stability of the flux-to-voltage transfer coefficients of the SQUID electronics is investigated in detail and a method is presented to significantly increase their reproducibility. We further demonstrate the long-term operation of the setup in a magnetic field varying by about 200 μT amplitude without the need for recalibration.

  13. Sound wave velocities of fcc Fe Ni alloy at high pressure and temperature by mean of inelastic X-ray scattering

    NASA Astrophysics Data System (ADS)

    Kantor, Anastasia P.; Kantor, Innokenty Yu.; Kurnosov, Alexander V.; Kuznetsov, Alexei Yu.; Dubrovinskaia, Natalia A.; Krisch, Michael; Bossak, Alexei A.; Dmitriev, Vladimir P.; Urusov, Vadim S.; Dubrovinsky, Leonid S.

    2007-09-01

    Knowledge of the high-pressure and high-temperature elasticity of Fe-Ni alloy with low (5-25%) Ni content is crucial for geosciences since it is probably the major component of the cores of the terrestrial planets and the Moon. Here we present a study of a FeNi alloy with 22 at.% of Ni to 72 GPa and 715 K, using inelastic X-ray scattering (IXS) and X-ray powder diffraction from polycrystalline material. The X-ray diffraction (XRD) study revealed stability of the face centred cubic (fcc) over the hexagonal close packed (hcp) phase in the whole investigated pressure-temperature range. The study presents first investigations of elasticity of fcc phase of iron-nickel Fe 0.78Ni 0.22 alloy. The isothermal equations of state were derived at room temperature and at 715 K ( K300 = 162(1) GPa, K300=4.97(1), V300 = 6.89(1) cm 3/mol; K715 = 160(1) GPa, K715=4.97(2), V715 = 6.96(1) cm 3/mol). Inelastic X-ray measurements allow the determination of the longitudinal acoustic wave velocity VP, and provide, combined with the measured equations of state, the full isotropic elasticity of the material. We found that within experimental errors our data follow the Birch's law. We did not observe any significant deviations for fcc Fe 0.78Ni 0.22 from elastic properties of pure ɛ-iron.

  14. Extracting infrared absolute reflectance from relative reflectance measurements.

    PubMed

    Berets, Susan L; Milosevic, Milan

    2012-06-01

    Absolute reflectance measurements are valuable to the optics industry for development of new materials and optical coatings. Yet, absolute reflectance measurements are notoriously difficult to make. In this paper, we investigate the feasibility of extracting the absolute reflectance from a relative reflectance measurement using a reference material with known refractive index.

  15. A Conceptual Approach to Absolute Value Equations and Inequalities

    ERIC Educational Resources Information Center

    Ellis, Mark W.; Bryson, Janet L.

    2011-01-01

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

  16. Structure and Absolute Configuration of Diterpenoids from Hymenaea stigonocarpa.

    PubMed

    Monteiro, Afif F; Batista, João M; Machado, Michelle A; Severino, Richele P; Blanch, Ewan W; Bolzani, Vanderlan S; Vieira, Paulo C; Severino, Vanessa G P

    2015-06-26

    Chemical investigations of the ethanolic extracts from the flowers and leaves of Hymenaea stigonocarpa Mart. ex Hayne afforded one new ent-halimane diterpenoid, 18-hydroxy-ent-halima-1(10),13-(E)-dien-15-oic acid (1), together with five known compounds (2-6). The structural elucidation was performed by means of NMR (COSY, HSQC, HMBC, and NOESY) and MS analyses. Complete (1)H and (13)C NMR data assignments are also reported for labd-13-en-8β-ol-15-oic (2) and labd-7,13-dien-15-oic (3) acids. The absolute configurations of 1 and 2 were established by comparison of experimental and calculated Raman optical activity spectra.

  17. Absolute stress measurements at the rangely anticline, Northwestern Colorado

    USGS Publications Warehouse

    de la Cruz, R. V.; Raleigh, C.B.

    1972-01-01

    Five different methods of measuring absolute state of stress in rocks in situ were used at sites near Rangely, Colorado, and the results compared. For near-surface measurements, overcoring of the borehole-deformation gage is the most convenient and rapid means of obtaining reliable values for the magnitude and direction of the state of stress in rocks in situ. The magnitudes and directions of the principal stresses are compared to the geologic features of the different areas of measurement. The in situ stresses are consistent in orientation with the stress direction inferred from the earthquake focal-plane solutions and existing joint patterns but inconsistent with stress directions likely to have produced the Rangely anticline. ?? 1972.

  18. Relative and Absolute Error Control in a Finite-Difference Method Solution of Poisson's Equation

    ERIC Educational Resources Information Center

    Prentice, J. S. C.

    2012-01-01

    An algorithm for error control (absolute and relative) in the five-point finite-difference method applied to Poisson's equation is described. The algorithm is based on discretization of the domain of the problem by means of three rectilinear grids, each of different resolution. We discuss some hardware limitations associated with the algorithm,…

  19. Precision laser surveying instrument using atmospheric turbulence compensation by determining the absolute displacement between two laser beam components

    DOEpatents

    Veligdan, James T.

    1993-01-01

    Atmospheric effects on sighting measurements are compensated for by adjusting any sighting measurements using a correction factor that does not depend on atmospheric state conditions such as temperature, pressure, density or turbulence. The correction factor is accurately determined using a precisely measured physical separation between two color components of a light beam (or beams) that has been generated using either a two-color laser or two lasers that project different colored beams. The physical separation is precisely measured by fixing the position of a short beam pulse and measuring the physical separation between the two fixed-in-position components of the beam. This precisely measured physical separation is then used in a relationship that includes the indexes of refraction for each of the two colors of the laser beam in the atmosphere through which the beam is projected, thereby to determine the absolute displacement of one wavelength component of the laser beam from a straight line of sight for that projected component of the beam. This absolute displacement is useful to correct optical measurements, such as those developed in surveying measurements that are made in a test area that includes the same dispersion effects of the atmosphere on the optical measurements. The means and method of the invention are suitable for use with either single-ended systems or a double-ended systems.

  20. Temperature, radiation and aging analysis of the DORIS Ultra Stable Oscillator by means of the Time Transfer by Laser Link experiment on Jason-2

    NASA Astrophysics Data System (ADS)

    Belli, Alexandre; Exertier, P.; Samain, E.; Courde, C.; Vernotte, F.; Jayles, C.; Auriol, A.

    2016-12-01

    The Time Transfer by Laser Link (T2L2) experiment on-board the Jason-2 satellite was launched in June 2008 at 1335 km altitude. It has been designed to use the Satellite Laser Ranging (SLR) space technique as an optical link between ground and space clocks. T2L2, as all the instruments aboard Jason-2, is referenced to the Ultra Stable Oscillator (USO) provided by the Doppler Orbitography and Radio-positioning Integrated by Satellite (DORIS) system. A complex data processing has been developed in order to extract time & frequency products as the relative frequency bias of the USO from ground-to-space time transfer passages. The precision of these products was estimated of a few parts in 10-13 given the very good in-flight performance of T2L2 with a ground-to-space time stability of a few picoseconds (ps) over 100 s. Frequency bias from T2L2 were compared with results from operational orbit computation, notably with the DIODE (Détermination Immédiate d'Orbite par Doris Embarqué) outputs (see Jayles et al. (2016) same issue) at the level of 1 · 10-12. The present paper is focusing on the main physical effects which drive the frequency variations of the Jason-2 USO during its flight, notably over the South Atlantic Anomaly (SAA) area. In addition to the effects of radiation we studied the effect of the residual temperature variations, in the range 8-11 °C (measured on-board). A model was established to represent these effects on the short term with empirical coefficients (sensitivities of the USO) to be adjusted. The results of fitting the model over ∼200 10-day periods, from 2008 to 2014, show the sensitivities of the Jason-2 USO to temperature and radiation. The analysis of the 6-year output series of empirical coefficients allows us to conclude that: (i) the temperature to frequency dependence is very stable along time at the level of around -1.2 · 10-12 per °C, (ii) the radiation effects are much lower than those previously detected on the Jason-1 USO with

  1. Comparison of Local Scale Measured and Modeled Brightness Temperatures and Snow Parameters from the CLPX 2003 by Means of a Dense Medium Radiative Transfer Theory Model

    NASA Technical Reports Server (NTRS)

    Tedescol, Marco; Kim, Edward J.; Cline, Don; Graf, Tobias; Koike, Toshio; Armstrong, Richard; Brodzik, Mary J.; Hardy, Janet

    2004-01-01

    Microwave remote sensing offers distinct advantages for observing the cryosphere. Solar illumination is not required, and spatial and temporal coverage are excellent from polar-orbiting satellites. Passive microwave measurements are sensitive to the two most useful physical quantities for many hydrological applications: physical temperature and water content/state. Sensitivity to the latter is a direct result of the microwave sensitivity to the dielectric properties of natural media, including snow, ice, soil (frozen or thawed), and vegetation. These considerations are factors motivating the development of future cryospheric satellite remote sensing missions, continuing and improving on a 26-year microwave measurement legacy. Perhaps the biggest issues regarding the use of such satellite measurements involve how to relate parameter values at spatial scales as small as a hectare to observations with sensor footprints that may be up to 25 x 25 km. The NASA Cold-land Processes Field Experiment (CLPX) generated a dataset designed to enhance understanding of such scaling issues. CLPX observations were made in February (dry snow) and March (wet snow), 2003 in Colorado, USA, at scales ranging from plot scale to 25 x 25 km satellite footprints. Of interest here are passive microwave observations from ground-based, airborne, and satellite sensors, as well as meteorological and snowpack measurements that will enable studies of the effects of spatial heterogeneity of surface conditions on the observations. Prior to performing such scaling studies, an evaluation of snowpack forward modelling at the plot scale (least heterogeneous scale) is in order. This is the focus of this paper. Many forward models of snow signatures (brightness temperatures) have been developed over the years. It is now recognized that a dense medium radiative transfer (DMRT) treatment represents a high degree of physical fidelity for snow modeling, yet dense medium models are particularly sensitive to

  2. Use of Absolute and Comparative Performance Feedback in Absolute and Comparative Judgments and Decisions

    ERIC Educational Resources Information Center

    Moore, Don A.; Klein, William M. P.

    2008-01-01

    Which matters more--beliefs about absolute ability or ability relative to others? This study set out to compare the effects of such beliefs on satisfaction with performance, self-evaluations, and bets on future performance. In Experiment 1, undergraduate participants were told they had answered 20% correct, 80% correct, or were not given their…

  3. Residual energy application program: Utilization of high-temperature waste heat by means of Rankine-cycle engines. A technical summary

    NASA Astrophysics Data System (ADS)

    1981-10-01

    High temperature residual or waste heat which is directly discharged by industries and utilities in the form of exhaust gases and which can be converted to useful energy through the use of Rankine bottoming cycle (RBC) engines is discussed. The potential markets for RCB's in industrial processing, the gas pipeline industry, and municipal and public utilities are discussed. The potential oil savings and foreseeable factors that can affect RCB market penetration in these industries are summarized. The operating principles and system efficiency of a Rankine cycle system are discussed. In selecting a Rankine engine for a given application, consideration must be given to the thermodynamic properties and thermal stability of its working fluid as well as to the fluid's safety properties.

  4. Determination of the Temperature Change by Means of an Outcoming Signal of Electric Resistance in an Isoperibolic Calorimetric Cell. Obtainment of Heat Solution

    PubMed Central

    Giraldo-Gutierréz, Liliana; Moreno-Piraján, Juan Carlos

    2005-01-01

    An isoperibolic calorimetric cell is built with glass surrounded by plastic insulation. The cell has a lid on which a thermistor thermometer, an electric resistance to provide the cell with definite quantities of electric work and a container for a glass ampoule, are placed. For measuring the thermal changes, an NTC thermistor, which provides an electric resistance signal that varies with temperature, is used. Calibration curves of the thermistor and of the stabilization of the system signal in thermal equilibrium are shown, which enable the observation of a good insulation. The calorific capacity of the system with water, with a value of 206.7 ±0.7 J °C-1 is determined; the solution enthalpy for propanol-water and KCl-water systems is obtained, which shows the behavior of the cell before exothermic and endothermic effects, respectively.

  5. Correlation of electronic structure and magnetic moment in Ga1-xMnxN : First-principles, mean field and high temperature series expansions calculations

    NASA Astrophysics Data System (ADS)

    Masrour, R.; Hlil, E. K.

    2016-08-01

    Self-consistent ab initio calculations based on density-functional theory and using both full potential linearized augmented plane wave and Korring-Kohn-Rostoker-coherent potential approximation methods, are performed to investigate both electronic and magnetic properties of the Ga1-xMnxN system. Magnetic moments considered to lie along (001) axes are computed. Obtained data from ab initio calculations are used as input for the high temperature series expansions (HTSEs) calculations to compute other magnetic parameters such as the magnetic phase diagram and the critical exponent. The increasing of the dilution x in this system has allowed to verify a series of HTSEs predictions on the possibility of ferromagnetism in dilute magnetic insulators and to demonstrate that the interaction changes from antiferromagnetic to ferromagnetic passing through the spins glace phase.

  6. Surface Characterization of pNIPAM Under Varying Absolute Humidity

    NASA Astrophysics Data System (ADS)

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

    2012-11-01

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

  7. Monochromator-Based Absolute Calibration of a Standard Radiation Thermometer

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    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.

  8. Estimating the Mean Annual Surface Air Temperature at Armagh Observatory, Northern Ireland, and the Global Land-Ocean Temperature Index for Sunspot Cycle 24, the Current Ongoing Sunspot Cycle

    NASA Technical Reports Server (NTRS)

    Wilson, Robert M.

    2013-01-01

    As noted by Gray et al., Sir William Herschel was the first to suggest a possible close connection between the Sun and the Earth’s climate. The Sun, being the source of energy that impacts and drives the Earth’s climate system, displays a variety of changes over both short and long term time scales, the most obvious examples being the somewhat regular waxing and waning of sunspots with time (i.e., the sunspot cycle (SC)), first described by Samuel Heinrich Schwabe, a German apothecary and amateur astronomer who observed the Sun from Dessau, Germany, and the now well established variation of the Sun’s irradiance over the SC. Other factors related to the SC have been linked to changes in climate as well. Some of these other factors include the role of cosmic rays and the solar wind (i.e., the geomagnetic cycle) on climate, as well as the apparent close association between trends in global and northern hemispheric temperature and the length of the SC, although some investigators have described the inferred association between climate and, in particular, SC length as now being weak. More recently, Solheim et al. have reported on the relation between SC length and the average temperature in the same and immediately following SC for a number of meteorological stations in Norway and in the North Atlantic region. They noted that while they found no significant trend (correlation) between SC length and the average temperature when measured for the same cycle, in contrast, they found a significant negative trend when SC length was compared with the following cycle’s average temperature. From this observation, they suggested that average northern hemispheric temperature during the present ongoing SC (SC24) will be lower by about 0.9 °C than was seen in SC23 (spanning 1996–2007, based on yearly averages of sunspot number (SSN), and onset for SC24 occurring in 2008). The purpose of this Technical Publication (TP) is to examine the annual variations of the Armagh

  9. Leak rate estimation of a resistive plate chamber gap by monitoring absolute pressure

    NASA Astrophysics Data System (ADS)

    Mondal, S.; Datar, V. M.; Kalmani, S. D.; Majumder, G.; Mondal, N. K.; Satyanarayana, B.

    2016-11-01

    The differential pressure of a conventional manometer is highly dependent on the atmospheric pressure. The measurements with a manometer for an extended time period show a large variation due to solar atmospheric tides. However, the measurements of absolute pressure, both outside and inside of a resistive plate chamber (RPC), are independent of each other. By monitoring the absolute pressures, both outside and inside of a RPC, along with the temperature, its leakage rate can be estimated. During the test period, the supporting button spacers inside a RPC may get detached due to some manufacturing defect. This effect can be detected clearly by observing the sudden fall of pressure inside the chamber.

  10. Absolute nonlocality via distributed computing without communication

    NASA Astrophysics Data System (ADS)

    Czekaj, Ł.; Pawłowski, M.; Vértesi, T.; Grudka, A.; Horodecki, M.; Horodecki, R.

    2015-09-01

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

  11. In vivo absorption spectroscopy for absolute measurement.

    PubMed

    Furukawa, Hiromitsu; Fukuda, Takashi

    2012-10-01

    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.

  12. MAGSAT: Vector magnetometer absolute sensor alignment determination

    NASA Technical Reports Server (NTRS)

    Acuna, M. H.

    1981-01-01

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

  13. An estimate of global absolute dynamic topography

    NASA Technical Reports Server (NTRS)

    Tai, C.-K.; Wunsch, C.

    1984-01-01

    The absolute dynamic topography of the world ocean is estimated from the largest scales to a short-wavelength cutoff of about 6700 km for the period July through September, 1978. The data base consisted of the time-averaged sea-surface topography determined by Seasat and geoid estimates made at the Goddard Space Flight Center. The issues are those of accuracy and resolution. Use of the altimetric surface as a geoid estimate beyond the short-wavelength cutoff reduces the spectral leakage in the estimated dynamic topography from erroneous small-scale geoid estimates without contaminating the low wavenumbers. Comparison of the result with a similarly filtered version of Levitus' (1982) historical average dynamic topography shows good qualitative agreement. There is quantitative disagreement, but it is within the estimated errors of both methods of calculation.

  14. Absolute measurements of fast neutrons using yttrium.

    PubMed

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

    2010-08-01

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

  15. Measured and modelled absolute gravity in Greenland

    NASA Astrophysics Data System (ADS)

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

    2012-12-01

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

  16. Absolute GPS Positioning Using Genetic Algorithms

    NASA Astrophysics Data System (ADS)

    Ramillien, G.

    A new inverse approach for restoring the absolute coordinates of a ground -based station from three or four observed GPS pseudo-ranges is proposed. This stochastic method is based on simulations of natural evolution named genetic algorithms (GA). These iterative procedures provide fairly good and robust estimates of the absolute positions in the Earth's geocentric reference system. For comparison/validation, GA results are compared to the ones obtained using the classical linearized least-square scheme for the determination of the XYZ location proposed by Bancroft (1985) which is strongly limited by the number of available observations (i.e. here, the number of input pseudo-ranges must be four). The r.m.s. accuracy of the non -linear cost function reached by this latter method is typically ~10-4 m2 corresponding to ~300-500-m accuracies for each geocentric coordinate. However, GA can provide more acceptable solutions (r.m.s. errors < 10-5 m2), even when only three instantaneous pseudo-ranges are used, such as a lost of lock during a GPS survey. Tuned GA parameters used in different simulations are N=1000 starting individuals, as well as Pc=60-70% and Pm=30-40% for the crossover probability and mutation rate, respectively. Statistical tests on the ability of GA to recover acceptable coordinates in presence of important levels of noise are made simulating nearly 3000 random samples of erroneous pseudo-ranges. Here, two main sources of measurement errors are considered in the inversion: (1) typical satellite-clock errors and/or 300-metre variance atmospheric delays, and (2) Geometrical Dilution of Precision (GDOP) due to the particular GPS satellite configuration at the time of acquisition. Extracting valuable information and even from low-quality starting range observations, GA offer an interesting alternative for high -precision GPS positioning.

  17. Tsunakawa-Shaw method - an absolute paleointensity technique using alternating field demagnetization

    NASA Astrophysics Data System (ADS)

    Yamamoto, Y.; Mochizuki, N.; Shibuya, H.; Tsunakawa, H.

    2015-12-01

    Among geologic materials volcanic rocks have been typically used to deduce an absolute paleointensity. In the last decade, however, there seems a becoming consensus that volcanic rocks are not so ideal materials due to such as magnetic grains other than non-interacting single domain particles. One approach to obtain a good paleointensity estimate from the rocks is to reduce and correct the non-ideality, suppress alterations in laboratory and screen out suspicious results. We have been working on a development and an application of the Tsunakawa-Shaw method, which has been previously called the LTD-DHT Shaw method. This method is an AF(alternating field)-based technique and thus a paleointensity is estimated using coercivity spectra. To reduce the non-ideality, all remanences undergo low-temperature demagnetization (LTD) before any AF demagnetizations to remove multi-domain like component. To correct the non-ideality, anhysteretic remanent magnetizations (ARMs) are imparted with their directions parallel to natural remanent magnetizations and laboratory-imparted thermoremanent magnetizations (TRMs) and measured before and after laboratory heating. These ARMs are used to correct remanence anisotropies, possible interaction effects originated from the non-ideal grains and TRM changes caused by laboratory alterations. TRMs are imparted by heating specimens above their Curie temperatures and then cooling to room temperature at once to simulate nature conditions. These cycles are done in vacuum to suppress alterations in laboratory. Obtained results are judged by selection criteria, including a check for validity of the ARM corrections.It has been demonstrated that successful paleointensities are obtained from historical lavas in Japan and Hawaii, and from baked clay samples from a reconstructed ancient kiln, with the flow-mean precision of 5-10%. In case of old volcanic rocks, however, the method does not necessarily seem to be perfect. We will summarize these points in

  18. Further development of the dynamic gas temperature measurement system

    NASA Technical Reports Server (NTRS)

    Elmore, D. L.; Robinson, W. W.; Watkins, W. B.

    1986-01-01

    A compensated thermocouple measurement method was experimentally verified. Dynamic signal content from an atmospheric pressure laboratory burner was measured by the dynamic temperature sensor and a relatively delicate fine-wire resistance thermometer. Compensated data from the two dynamic temperature sensor thermoelements were compared with the compensated fine-wire data in the frequency domain. Absolute differences between spectral line amplitudes measured with different sensors are small relative to the mean temperature and verify the compenation method. Increases in precision of the measurement method require optimization of several factors, and directions for further work are identified.

  19. An atlas of monthly mean distributions of SSMI surface wind speed, AVHRR/2 sea surface temperature, AMI surface wind velocity, TOPEX/POSEIDON sea surface height, and ECMWF surface wind velocity during 1993

    NASA Technical Reports Server (NTRS)

    Halpern, D.; Fu, L.; Knauss, W.; Pihos, G.; Brown, O.; Freilich, M.; Wentz, F.

    1995-01-01

    The following monthly mean global distributions for 1993 are presented with a common color scale and geographical map: 10-m height wind speed estimated from the Special Sensor Microwave Imager (SSMI) on a United States (U.S.) Air Force Defense Meteorological Satellite Program (DMSP) spacecraft; sea surface temperature estimated from the Advanced Very High Resolution Radiometer (AVHRR/2) on a U.S. National Oceanic and Atmospheric Administration (NOAA) satellite; 10-m height wind speed and direction estimated from the Active Microwave Instrument (AMI) on the European Space Agency (ESA) European Remote Sensing (ERS-1) satellite; sea surface height estimated from the joint U.S.-France Topography Experiment (TOPEX)/POSEIDON spacecraft; and 10-m height wind speed and direction produced by the European Center for Medium-Range Weather Forecasting (ECMWF). Charts of annual mean, monthly mean, and sampling distributions are displayed.

  20. A study of the influence of isotopic substitution on the melting point and temperature of maximum density of water by means of path integral simulations of rigid models.

    PubMed

    McBride, Carl; Aragones, Juan L; Noya, Eva G; Vega, Carlos

    2012-11-21

    The melting point of ice I(h), as well as the temperature of maximum density (TMD) in the liquid phase, has been computed using the path integral Monte Carlo method. Two new models are introduced, TIP4PQ_D2O and TIP4PQ_T2O, which are specifically designed to study D(2)O and T(2)O respectively. We have also used these models to study the "competing quantum effects" proposal of Habershon, Markland and Manolopoulos; the TIP4PQ/2005, TIP4PQ/2005 (D(2)O) and TIP4PQ/2005 (T(2)O) models are able to study the isotopic substitution of hydrogen for deuterium or tritium whilst constraining the geometry, while the TIP4PQ_D2O and TIP4PQ_T2O models, where the O-H bond lengths are progressively shortened, permit the study of the influence of geometry (and thus dipole moment) on the isotopic effects. For TIP4PQ_D2O-TIP4PQ/2005 we found a melting point shift of 4.9 K (experimentally the value is 3.68 K) and a TMD shift of 6 K (experimentally 7.2 K). For TIP4PQ_T2O-TIP4PQ/2005 we found a melting point shift of 5.2 K (experimentally the value is 4.49 K) and a TMD shift of 7 K (experimentally 9.4 K).

  1. Initial full-diurnal-cycle mesopause region lidar observations: diurnal-means and tidal perturbations of temperature and winds over Fort Collins, CO (41°N,105°W)

    NASA Astrophysics Data System (ADS)

    She, Chiao-Yao

    2004-04-01

    The Colorado State Sodium lidar has been upgraded to a two-beam system capable of simultaneous measurements of mesopause region temperature and winds, over full diurnal-cycles, weather permitting. Though our lidar is a modest system with a power-aperture product of only 0.06Wm2, good data quality is demonstrated by means of contour plots depicting a 80-h continuous observation between August 9th and 12th, showing the existence of atmospheric waves with different periods along with their coherence and interactions. The salient feature of data with full-diurnal-cycle coverage lies in its ability to describe the vertical profiles of dynamical fields (temperature, zonal and meridional winds) as a unique linear superposition of diurnal-mean and oscillations with different tidal periods, plus a residual term. In this manner, we investigate diurnal-means and oscillations with diurnal and semidiurnal periods. Using 6 data sets between July 17 and August 12, each covering a full-diurnal-cycle as a case study, we found considerable day-to-day variability, as much as 20K, 35 and 75m/s for diurnal-mean temperature, zonal wind and meridional wind, respectively, and as 15K, and 50m/s, for the diurnal and semidiurnal tidal temperature and wind amplitudes, respectively. While a minimum of 3 full diurnal cycles appears to be adequate in the case studied here, the 6-day composite yields diurnal-means and diurnal tides in agreement with model predictions very well. Since the resulting amplitudes and phases of the observed diurnal oscillations agree well with the global scale wave model, GSWM00 predictions, we conclude that the migrating diurnal tide contributes significantly to the observed oscillations with diurnal period over Fort Collins, CO (41°N, 105°W). Unlike the diurnal perturbations, the observed semidiurnal amplitudes and phases differ from the GSWM00 predictions with considerably smaller model amplitudes. The coherence of solar forcing is found to prevail over the

  2. Using star tracks to determine the absolute pointing of the Fluorescence Detector telescopes of the Pierre Auger Observatory

    SciTech Connect

    De Donato, Cinzia; Sanchez, Federico; Santander, Marcos; Natl.Tech.U., San Rafael; Camin, Daniel; Garcia, Beatriz; Grassi, Valerio; /Milan U. /INFN, Milan

    2005-05-01

    To accurately reconstruct a shower axis from the Fluorescence Detector data it is essential to establish with high precision the absolute pointing of the telescopes. To d that they calculate the absolute pointing of a telescope using sky background data acquired during regular data taking periods. The method is based on the knowledge of bright star's coordinates that provide a reliable and stable coordinate system. it can be used to check the absolute telescope's pointing and its long-term stability during the whole life of the project, estimated in 20 years. They have analyzed background data taken from January to October 2004 to determine the absolute pointing of the 12 telescopes installed both in Los Leones and Coihueco. The method is based on the determination of the mean-time of the variance signal left by a star traversing a PMT's photocathode which is compared with the mean-time obtained by simulating the track of that star on the same pixel.

  3. Absolute Properties of the Upper Main-Sequence Eclipsing Binary Star MU Cassiopeiae

    NASA Astrophysics Data System (ADS)

    Lacy, Claud H. Sandberg; Claret, Antonio; Sabby, Jeffrey A.

    2004-10-01

    We present 6151 differential observations in the V filter measured by a robotic telescope, as well as 29 pairs of radial velocities from high-resolution spectroscopic observations, of the detached, EA-type, 9.65 day period double-lined eclipsing binary star MU Cas. Absolute dimensions of the components are determined with good precision (better than 2% in the masses and radii) for the purpose of testing various aspects of theoretical modeling. We obtain 4.57+/-0.09 Msolar and 3.67+/-0.04 Rsolar for the hotter, but smaller, less massive and less luminous photometric primary (star A), and 4.66+/-0.10 Msolar and 4.19+/-0.05 Rsolar for the cooler, larger, more massive and more luminous photometric secondary (star B). The effective temperatures and interstellar reddening of the stars are accurately determined from uvbyβ photometry: 15,100+/-500 K for the primary, 14,750+/-500 K for the secondary-corresponding to spectral types of B5 and B5-and 0.356 mag for Eb-y. The stars are located at a distance of about 1.7 kpc near the plane of the Galactic disk. The orbits of the stars are eccentric, and spectral line widths give observed rotational velocities that are synchronous with the mean orbital motion for both components. The components of MU Cas are upper main-sequence stars with an age of about 65 Myr according to models.

  4. Predicting the partitioning of biological compounds between room-temperature ionic liquids and water by means of the solvation-parameter model.

    PubMed

    Padró, Juan M; Ponzinibbio, Agustín; Mesa, Leidy B Agudelo; Reta, Mario

    2011-03-01

    The partition coefficients, P(IL/w), for different probe molecules as well as for compounds of biological interest between the room-temperature ionic liquids (RTILs) 1-butyl-3-methylimidazolium hexafluorophosphate, [BMIM][PF(6)], 1-hexyl-3-methylimidazolium hexafluorophosphate, [HMIM][PF(6)], 1-octyl-3-methylimidazolium tetrafluoroborate, [OMIM][BF(4)] and water were accurately measured. [BMIM][PF(6)] and [OMIM][BF(4)] were synthesized by adapting a procedure from the literature to a simpler, single-vessel and faster methodology, with a much lesser consumption of organic solvent. We employed the solvation-parameter model to elucidate the general chemical interactions involved in RTIL/water partitioning. With this purpose, we have selected different solute descriptor parameters that measure polarity, polarizability, hydrogen-bond-donor and hydrogen-bond-acceptor interactions, and cavity formation for a set of specifically selected probe molecules (the training set). The obtained multiparametric equations were used to predict the partition coefficients for compounds not present in the training set (the test set), most being of biological interest. Partial solubility of the ionic liquid in water (and water into the ionic liquid) was taken into account to explain the obtained results. This fact has not been deeply considered up to date. Solute descriptors were obtained from the literature, when available, or else calculated through commercial software. An excellent agreement between calculated and experimental log P(IL/w) values was obtained, which demonstrated that the resulting multiparametric equations are robust and allow predicting partitioning for any organic molecule in the biphasic systems studied.

  5. A new determination of the Geneva photometric passbands and their absolute calibration

    NASA Astrophysics Data System (ADS)

    Rufener, F.; Nicolet, B.

    The consensus regarding the absolute calibrations of the spectra of alpha Lyr and subdwarfs provoked a revision of the calibration of the Geneva photometric system passbands. The alterations made to the earlier version by Rufener and Maeder (1971) are smaller than plus or minus -5 percent. The new response functions are presented in tabular form for an equiphotonic flux. An absolute spectrophotometric adjustment allows to obtain for each entry of the Geneva catalog (28,000 stars) a corresponding spectrophotometric description in SI units. The definition and the means of computing the necessary quasi-isophotal frequencies or wavelengths are given. The coherence of the Geneva catalog with several sets of absolute spectrophotometric data is examined. A correction for the entire Gunn and Stryker (1983) catalog is proposed.

  6. Absolute Binding Energies of Core Levels in Solids from First Principles

    NASA Astrophysics Data System (ADS)

    Ozaki, Taisuke; Lee, Chi-Cheng

    2017-01-01

    A general method is presented to calculate absolute binding energies of core levels in metals and insulators, based on a penalty functional and an exact Coulomb cutoff method in the framework of density functional theory. The spurious interaction of core holes between supercells is avoided by the exact Coulomb cutoff method, while the variational penalty functional enables us to treat multiple splittings due to chemical shift, spin-orbit coupling, and exchange interaction on equal footing, both of which are not accessible by previous methods. It is demonstrated that the absolute binding energies of core levels for both metals and insulators are calculated by the proposed method in a mean absolute (relative) error of 0.4 eV (0.16%) for eight cases compared to experimental values measured with x-ray photoemission spectroscopy within a generalized gradient approximation to the exchange-correlation functional.

  7. Absolute Geostrophic Velocity Inverted from World Ocean Atlas 2013 (WOAV13) with the P-Vector Method

    DTIC Science & Technology

    2015-11-01

    1 WOAV13: world ocean absolute geostrophic velocity Absolute Geostrophic Velocity Inverted from... World Ocean Atlas 2013 (WOAV13) with the P-Vector Method P. C. Chu* and C. W. Fan Naval Ocean Analysis and Prediction (NOAP) Laboratory...from World Ocean Atlas-2013 (WOA13) temperature and salinity fields using the P-vector method. It provides a climatological velocity field that is

  8. Determining Absolute Zero Using a Tuning Fork

    ERIC Educational Resources Information Center

    Goldader, Jeffrey D.

    2008-01-01

    The Celsius and Kelvin temperature scales, we tell our students, are related. We explain that a change in temperature of 1 degree C corresponds to a change of 1 Kelvin and that atoms and molecules have zero kinetic energy at zero Kelvin, -273 degrees C. In this paper, we will show how students can derive the relationship between the Celsius and…

  9. Absolute Calibration of the AXAF Telescope Effective Area

    NASA Technical Reports Server (NTRS)

    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

    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

  10. Absolute calibration of the EnviSat-1 radar altimeter

    NASA Astrophysics Data System (ADS)

    Roca, Monica; Francis, Richard

    1998-12-01

    The EnviSat-1 satellite will embark an innovative radar altimeter. The calibration of the measurements of range from this instrument will be performed using novel techniques. The range measurement will be calibrated absolutely by establishing the actual geocentric sea-level along the sub- satellite tracks. These tracks are located in a limited and well-controlled region in the western Mediterranean and will include a number of fully-equipped individual sites which will provide higher confidence in the overall analysis, combined with data from the whole area at lower weight. The determination of the geocentric sea-level is performed using tide gauges and geodetic means such as leveling and floating GPS receivers. The altimeter sea-level is derived from the altimeter range corrected for propagation effects and sea- state bias, and a precise restitution of the trajectory of the satellite. These measurements comprise three vectors: range, orbital height and sea-surface height. The difference between orbital-height minus range, and sea-surface height provides the bias. The backscatter coefficient measured by previous altimeters has not been absolutely calibrated. An emerging application of the RA-2 in investigation of surface properties has identified the need to perform this calibration. A number of techniques are under study to determine the feasibility of meeting this need, including the use of well-controlled natural targets, the use of the altimeter receiver as a passive radiometer in order to determine its gain and the use of a transponder to return a precisely known return echo power to the radar.

  11. High Accuracy, Absolute, Cryogenic Refractive Index Measurements of Infrared Lens Materials for JWST NIRCam using CHARMS

    NASA Technical Reports Server (NTRS)

    Leviton, Douglas; Frey, Bradley

    2005-01-01

    The current refractive optical design of the James Webb Space Telescope (JWST) Near Infrared Camera (NIRCam) uses three infrared materials in its lenses: LiF, BaF2, and ZnSe. In order to provide the instrument s optical designers with accurate, heretofore unavailable data for absolute refractive index based on actual cryogenic measurements, two prismatic samples of each material were measured using the cryogenic, high accuracy, refraction measuring system (CHARMS) at NASA GSFC, densely covering the temperature range from 15 to 320 K and wavelength range from 0.4 to 5.6 microns. Measurement methods are discussed and graphical and tabulated data for absolute refractive index, dispersion, and thermo-optic coefficient for these three materials are presented along with estimates of uncertainty. Coefficients for second order polynomial fits of measured index to temperature are provided for many wavelengths to allow accurate interpolation of index to other wavelengths and temperatures.

  12. Beginning of grain harvest in the tri-border region Basel as a proxy for mean April - May temperatures; creation of a long Swiss series c. 1455 AD - 1950 AD

    NASA Astrophysics Data System (ADS)

    Wetter, Oliver; Pfister, Christian

    2010-05-01

    Beginning of grain harvest in the tri-border region Basel as a proxy for mean April-July temperatures; creation of a long Swiss series c. 1454 AD - 1950 AD O. Wetter and C. Pfister Section of Economic, Social and Environmental History, Institute of History, University of Bern, Bern, Switzerland (oliver.wetter@hist.unibe.ch) Before agricultural harvesting machines replaced manual labour the date of the grain harvest was largely dependent on mean temperatures from spring to early summer. It thus constitutes a very valuable source of information to reconstruct these temperatures. The later the harvest began, the cooler spring and early summer must have been and vice versa. For this reconstruction a new data series of grain harvests in the tri-border region Basel (representative for north-west Switzerland, the Alsace (France) and south-west Germany) was used as a temperature proxy. The harvesting dates have been extracted from the account books of the hospital of Basel which cover the period from c.1454 AD to 1705 AD. This series could be completed with several series of grain tithe dates originating from the Swiss Midland, covering the period between 1557 and 1825 and several grain harvest dates series covering the time between 1825 and 1950. Thus a series of almost 500 years could be compiled. Since the method of harvesting remained unchanged until the 1950's when manual labour was replaced by machines, the harvest dates of the modern series, lying within the temperature measurement series, could be used for calibrating the medieval dates.

  13. Absolute paleointensity from Hawaiian lavas younger than 35 ka

    USGS Publications Warehouse

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

    1998-01-01

    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.

  14. Robust absolute magnetometry with organic thin-film devices

    PubMed Central

    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

    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

  15. Near-infrared absolute magnitudes of Type Ia Supernovae

    NASA Astrophysics Data System (ADS)

    Avelino, Arturo; Friedman, Andrew S.; Mandel, Kaisey; Kirshner, Robert; Challis, Peter

    2017-01-01

    Type Ia Supernovae light curves (SN Ia) in the near infrared (NIR) exhibit low dispersion in their peak luminosities and are less vulnerable to extinction by interstellar dust in their host galaxies. The increasing number of high quality NIR SNe Ia light curves, including the recent CfAIR2 sample obtained with PAIRITEL, provides updated evidence for their utility as standard candles for cosmology. Using NIR YJHKs light curves of ~150 nearby SNe Ia from the CfAIR2 and CSP samples, and from the literature, we determine the mean value and dispersion of the absolute magnitude in the range between -10 to 50 rest-frame days after the maximum luminosity in B band. We present the mean light-curve templates and Hubble diagram for YJHKs bands. This work contributes to a firm local anchor for supernova cosmology studies in the NIR which will help to reduce the systematic uncertainties due to host galaxy dust present in optical-only studies. This research is supported by NSF grants AST-156854, AST-1211196, Fundacion Mexico en Harvard, and CONACyT.

  16. Absolute calibration of forces in optical tweezers

    NASA Astrophysics Data System (ADS)

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

    2014-07-01

    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.

  17. Elevation correction factor for absolute pressure measurements

    NASA Technical Reports Server (NTRS)

    Panek, Joseph W.; Sorrells, Mark R.

    1996-01-01

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

  18. Climate Absolute Radiance and Refractivity Observatory (CLARREO)

    NASA Technical Reports Server (NTRS)

    Leckey, John P.

    2015-01-01

    The Climate Absolute Radiance and Refractivity Observatory (CLARREO) is a mission, led and developed by NASA, that will measure a variety of climate variables with an unprecedented accuracy to quantify and attribute climate change. CLARREO consists of three separate instruments: an infrared (IR) spectrometer, a reflected solar (RS) spectrometer, and a radio occultation (RO) instrument. The mission will contain orbiting radiometers with sufficient accuracy, including on orbit verification, to calibrate other space-based instrumentation, increasing their respective accuracy by as much as an order of magnitude. The IR spectrometer is a Fourier Transform spectrometer (FTS) working in the 5 to 50 microns wavelength region with a goal of 0.1 K (k = 3) accuracy. The FTS will achieve this accuracy using phase change cells to verify thermistor accuracy and heated halos to verify blackbody emissivity, both on orbit. The RS spectrometer will measure the reflectance of the atmosphere in the 0.32 to 2.3 microns wavelength region with an accuracy of 0.3% (k = 2). The status of the instrumentation packages and potential mission options will be presented.

  19. Absolute flux measurements for swift atoms

    NASA Technical Reports Server (NTRS)

    Fink, M.; Kohl, D. A.; Keto, J. W.; Antoniewicz, P.

    1987-01-01

    While a torsion balance in vacuum can easily measure the momentum transfer from a gas beam impinging on a surface attached to the balance, this measurement depends on the accommodation coefficients of the atoms with the surface and the distribution of the recoil. A torsion balance is described for making absolute flux measurements independent of recoil effects. The torsion balance is a conventional taut suspension wire design and the Young modulus of the wire determines the relationship between the displacement and the applied torque. A compensating magnetic field is applied to maintain zero displacement and provide critical damping. The unique feature is to couple the impinging gas beam to the torsion balance via a Wood's horn, i.e., a thin wall tube with a gradual 90 deg bend. Just as light is trapped in a Wood's horn by specular reflection from the curved surfaces, the gas beam diffuses through the tube. Instead of trapping the beam, the end of the tube is open so that the atoms exit the tube at 90 deg to their original direction. Therefore, all of the forward momentum of the gas beam is transferred to the torsion balance independent of the angle of reflection from the surfaces inside the tube.

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

    DOEpatents

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

    2015-12-01

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