Preliminary study of a radiological survey in an abandoned uranium mining area in Madagascar

NASA Astrophysics Data System (ADS)

N, Rabesiranana; M, Rasolonirina; F, Solonjara A.; Andriambololona., Raoelina; L, Mabit

2010-05-01

The region of Vinaninkarena located in central Madagascar (47°02'40"E, 19°57'17"S), is known to be a high natural radioactive area. Uranium ore was extracted in this region during the 1950s and the early 1960s. In the mid-1960s, mining activities were stopped and the site abandoned. In the meantime, the region, which used to be without any inhabitants, has recently been occupied by new settlers with presumed increase in exposure of the local population to natural ionizing radiation. In order to assess radiological risk, a survey to assess the soil natural radioactivity background was conducted during the year 2004. This study was implemented in the frame of the FADES Project SP99v1b_21 entitled: Assessment of the environmental pollution by multidisciplinary approach, and the International Atomic Energy Agency Technical Cooperation Project MAG 7002 entitled: Effects of air and water pollution on human health. Global Positioning System (GPS) was used to determine the geographical coordinates of the top soil samples (0-15cm) collected. The sampling was performed using a multi integrated scale approach to estimate the spatial variability of the parameters under investigation (U, Th and K) using geo-statistical approach. A total of 205 soil samples was collected in the study site (16 km2). After humidity correction, the samples were sealed in 100 cm3 cylindrical air-tight plastic containers and stored for more than 6 months to reach a secular equilibrium between parents and short-lived progeny (226Ra and progeny, 238U and 234Th). Measurements were performed using a high-resolution HPGe Gamma-detector with a 30% relative efficiency and an energy resolution of 1.8 keV at 1332.5 keV, allowing the determination of the uranium and thorium series and 40K. In case of secular equilibrium, a non-gamma-emitting radionuclide activity was deduced from its gamma emitting progeny. This was the case for 238U (from 234Th), 226Ra (from 214Pb and 214Bi) and 232Th (from 228Ac, 212Pb or 208Tl). Furthermore, in order to assess the radiological effect, the kerma rate in the air at 1 m above ground level was calculated for each sampled points using standard activity-kerma rate conversion coefficients for uranium, thorium series and potassium. Geostatistical interpolation tools (e.g. Inverse Distance Weighting power 2 and Ordinary Kriging) were used to optimize the data set mapping. The measured Potassium-40 activity was 333 Bq kg-1 ± 95% (Mean ± Coefficient of Variation), the Uranium activity was 195 Bq kg-1 ± 53% and the Thorium activity was 139 Bq kg-1 ± 29%. The world average concentrations are reported by the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) as 400 Bq kg-1 for 40K, 35 Bq kg-1 for 238U and 30 Bq kg-1 for 232Th. The results show that generally, 40K concentrations in soils of the area are slightly lower than the world average value, whereas uranium and thorium series activities are noticeably higher. On average the kerma rate reaches 143 nGy h-1 with a standard deviation of 41 nGy h-1 and a coefficient of variation of 28%. The information obtained was mapped and the dose exposition was also assessed for the local settlers. Key-words: soil contamination, environmental radioactivity, radioecology, dose exposure.

Testing the Delayed Gamma Capability in MCNP6

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

Weldon, Robert A.; Fensin, Michael L.; McKinney, Gregg W.

The mission of the Domestic Nuclear Detection Office is to quickly and reliably detect unauthorized attempts to import or transport special nuclear material for use against the United States. Developing detection equipment to meet this objective requires accurate simulation of both the detectable signature and detection mechanism. A delayed particle capability was initially added to MCNPX 2.6.A in 2005 to sample the radioactive fission product parents and emit decay particles resulting from the decay chain. To meet the objectives of detection scenario modeling, the capability was designed to sample a particular time for emitting particular multiplicity of a particular energy.more » Because the sampling process of selecting both time and energy is interdependent, to linearize the time and emission sampling, atom densities are computed at several discrete time steps, and the time-integrated production is computed by multiplying the atom density by the decay constant and time step size to produce a cumulative distribution function for sampling the emission time, energy, and multiplicity. The delayed particle capability was initially given a time-bin structure to help reasonably reproduce, from a qualitative sense, a fission benchmark by Beddingfield, which examined the delayed gamma emission. This original benchmark was only qualitative and did not contain the magnitudes of the actual measured data but did contain relative graphical representation of the spectra. A better benchmark with measured data was later provided by Hunt, Mozin, Reedy, Selpel, and Tobin at the Idaho Accelerator Center; however, because of the complexity of the benchmark setup, sizable systematic errors were expected in the modeling, and initial results compared to MCNPX 2.7.0 showed errors outside of statistical fluctuation. Presented in this paper is a more simplified approach to benchmarking, utilizing closed form analytic solutions to the granddaughter equations for particular sets of decay systems. We examine five different decay chains (two-stage decay to stable) and show the predictability of the MCNP6 delayed gamma feature. Results do show that while the default delayed gamma calculations available in the MCNP6 1.0 release can give accurate results for some isotopes (e.g., 137Ba), the percent differences between the closed form analytic solutions and the MCNP6 calculations were often >40% ( 28Mg, 28Al, 42K, 47Ca, 47Sc, 60Co). With the MCNP6 1.1 Beta release, the tenth entry on the DBCN card allows improved calculation within <5% as compared to the closed form analytic solutions for immediate parent emissions and transient equilibrium systems. While the tenth entry on the DBCN card for MCNP6 1.1 gives much better results for transient equilibrium systems and parent emissions in general, it does little to improve daughter emissions of secular equilibrium systems. Finally, hypotheses were presented as to why daughter emissions of secular equilibrium systems might be mispredicted in some cases and not in others.« less

Temporal changes in water quality at a childhood leukemia cluster.

PubMed

Seiler, Ralph L

2004-01-01

Since 1997, 15 cases of acute lymphocytic leukemia and one case of acute myelocytic leukemia have been diagnosed in children and teenagers who live, or have lived, in an area centered on the town of Fallon, Nevada. The expected rate for the population is about one case every five years. In 2001, 99 domestic and municipal wells and one industrial well were sampled in the Fallon area. Twenty-nine of these wells had been sampled previously in 1989. Statistical comparison of concentrations of major ions and trace elements in those 29 wells between 1989 and 2001 using the nonparametric Wilcoxon signed-rank test indicate water quality did not substantially change over that period; however, short-term changes may have occurred that were not detected. Volatile organic compounds were seldom detected in ground water samples and those that are regulated were consistently found at concentrations less than the maximum contaminant level (MCL). The MCL for gross-alpha radioactivity and arsenic, radon, and uranium concentrations were commonly exceeded, and sometimes were greatly exceeded. Statistical comparisons using the nonparametric Wilcoxon rank-sum test indicate gross-alpha and -beta radioactivity, arsenic, uranium, and radon concentrations in wells used by families having a child with leukemia did not statistically differ from the remainder of the domestic wells sampled during this investigation. Isotopic measurements indicate the uranium was natural and not the result of a 1963 underground nuclear bomb test near Fallon. In arid and semiarid areas where trace-element concentrations can greatly exceed the MCL, household reverse-osmosis units may not reduce their concentrations to safe levels. In parts of the world where radon concentrations are high, water consumed first thing in the morning may be appreciably more radioactive than water consumed a few minutes later after the pressure tank has been emptied because secular equilibrium between radon and its immediate daughter progeny is attained in pressure tanks overnight.

Temporal changes in water quality at a childhood leukemia cluster

USGS Publications Warehouse

Seiler, R.L.

2004-01-01

Since 1997, 15 cases of acute lymphocytic leukemia and one case of acute myelocytic leukemia have been diagnosed in children and teenagers who live, or have lived, in an area centered on the town of Fallon, Nevada. The expected rate for the population is about one case every five years. In 2001, 99 domestic and municipal wells and one industrial well were sampled in the Fallon area. Twenty-nine of these wells had been sampled previously in 1989. Statistical comparison of concentrations of major ions and trace elements in those 29 wells between 1989 and 2001 using the nonparametric Wilcoxon signed-rank test indicate water quality did not substantially change over that period; however, short-term changes may have occurred that were not detected. Volatile organic compounds were seldom detected in ground water samples and those that are regulated were consistently found at concentrations less than the maximum contaminant level (MCL). The MCL for gross-alpha radioactivity and arsenic, radon, and uranium concentrations were commonly exceeded, and sometimes were greatly exceeded. Statistical comparisons using the nonparametric Wilcoxon rank-sum test indicate gross-alpha and -beta radioactivity, arsenic, uranium, and radon concentrations in wells used by families having a child with leukemia did not statistically differ from the remainder of the domestic wells sampled during this investigation. Isotopic measurements indicate the uranium was natural and not the result of a 1963 underground nuclear bomb test near Fallon. In arid and semiarid areas where trace-element concentrations can greatly exceed the MCL, household reverse-osmosis units may not reduce their concentrations to safe levels. In parts of the world where radon concentrations are high, water consumed first thing in the morning may be appreciably more radioactive than water consumed a few minutes later after the pressure tank has been emptied because secular equilibrium between radon and its immediate daughter progeny is attained in pressure tanks overnight.

Triple Oxygen Isotope Constraints on Seawater δ18O and Temperature

NASA Astrophysics Data System (ADS)

Hayles, J.; Shen, B.; Homann, M.; Yeung, L.

2017-12-01

One point of contention among geoscientists is whether the 18O/16O ratio of seawater is roughly constant, or if it varies considerably throughout geologic time. On one hand, the oxygen isotope composition of the ocean is thought to be well buffered by high- and low-temperature interactions between seawater and seafloor rocks. If these interactions do not vary on billion-year timescales, the oxygen-isotope compositions of marine sedimentary rocks mostly relate to changes in seawater temperature and global ice volume. On the other hand, long-term cooling of the planetary interior would alter these water-rock interactions leading to a secular change in the oxygen isotope composition of seawater. Models suggest that this secular change would enrich seawater with heavy oxygen isotopes over time. In this study, we present new, high precision, triple-oxygen-isotope (18O/16O, 17O/16O) analyses of marine chert samples from 3.45 Ga to 460Ma. The results of these analyses are paired with a new theoretical quartz-water equilibrium curve and a simplified seawater model to provide possible pairings of δ'18O and Δ'17O for the water which these samples could have formed in equilibrium with. Analysis of the new sample data, in addition to published chert triple oxygen isotope compositions, shows a general trend of older chert samples being progressively incompatible with waters possessing a modern-like seawater triple oxygen isotope composition. Implications on constraining the secular evolution of seawater δ18O and temperature will be discussed.

Committed effective dose from naturally occuring radionuclides in shellfish

NASA Astrophysics Data System (ADS)

Khandaker, Mayeen Uddin; Wahib, Norfadira Binti; Amin, Yusoff Mohd.; Bradley, D. A.

2013-07-01

Recognizing their importance in the average Malaysian daily diet, the radioactivity concentrations in mollusc- and crustacean-based food have been determined for key naturally occuring radionuclides. Fresh samples collected from various maritime locations around peninsular Malaysia have been processed using standard procedures; the radionuclide concentrations being determined using an HPGe γ-ray spectrometer. For molluscs, assuming secular equilibrium, the range of activities of 238U (226Ra), 232Th (228Ra) and 40K were found to be 3.28±0.35 to 5.34±0.52, 1.20±0.21 to 2.44±0.21 and 118±6 to 281±14 Bq kg-1 dry weight, respectively. The respective values for crustaceans were 3.02±0.57 to 4.70±0.52, 1.38±0.21 to 2.40±0.35 and 216±11 to 316±15 Bq kg-1. The estimated average daily intake of radioactivity from consumption of molluscs are 0.37 Bq kg-1 for 238U (226Ra), 0.16 Bq kg-1 for 232Th (228Ra) and 18 Bq kg-1 for 40K; the respective daily intake values from crustaceans are 0.36 Bq kg-1, 0.16 Bq kg-1 and 23 Bq kg-1. Associated annual committed effective doses from molluscs are estimated to be in the range 21.3 to 34.7 μSv for 226Ra, 19.3 to 39.1 μSv for 228Ra and 17.0 to 40.4 μSv for 40K. For crustaceans, the respective dose ranges are 19.6 to 30.5 μSv, 22.0 to 38.4 μSv and 31.1 to 45.5 μSv, being some several times world average values.

A method for optimum PSA setting in the absence of a pure α or β emitter and its application in the determination of (237)Np/(233)Pa.

PubMed

Feng, Xiao-gui; He, Qian-ge; Wang, Jian-chen; Chen, Jing

2014-11-01

In the application of liquid scintillation counting (LSC), the α/β discrimination is carried out with the function of pulse shape analysis (PSA), which requires the setting of the optimum PSA level. The optimum PSA are usually determined by the generation of cross-over plots, whereby a pair of vials, one containing a pure α emitter and the other a pure β emitter, is counted. However, in some cases such as the determination of (237)Np/(233)Pa, a pure α emitter or a pure β emitter is not available. Therefore, we have developed a new approach to set the optimum PSA by measuring the sample itself of mixed α/β emitters. The count rate of the sample in the α-multi-channel analyzer changes monotonically with the increase of the PSA, and there is always an inflection point which is related to the optimum PSA. By fitting the data near the inflection point with the function y=ax(3)+bx(2)+cx+d, we can obtain the optimum PSA as -b/(3a), which can be used to determine the radioactivity of (237)Np/(233)Pa. The results obtained with this new approach were in good agreement with those obtained by HPGe γ spectrometry that was calibrated with an LSC sample of (237)Np/(233)Pa under a radioactive secular equilibrium. The new approach is promising to be used in simultaneous determination of gross α and β emitters, especially in the absence of a pure α or β emitter. Copyright © 2014 Elsevier Ltd. All rights reserved.

A secular technetium-molybdenum generator

NASA Astrophysics Data System (ADS)

Araujo, Wagner L.; Campos, Tarcisio P. R.

2015-05-01

A compact secular molybdenium generator is subject of this paper. This generator represents a nuclear system that comprises a hydrogen-isotopes fusor, moderator, reflector and shield. Deuterium fusion reactions in a tritiated or deuterated target provide the neutron source. A moderation fluid slowdown the neutron energy which increases 98Mo(n,γ)99Mo capture reaction rates. Neutron reflection minimizes the neutron escape and the radiation shield encloses the device. The neutron yield calculation along with electromagnetic and nuclear simulations were addressed. Results revealed the accelerator equipotential surfaces ranging from -30 to 150 kV, the ion trajectories and the energy beam profile define a deuteron current of 1 A with energy of 180 keV at the target, the spatial distribution of the neutron flux, and the 99Mo and 99mTc activities in function of transmuter operation time. The kinetics of the 99mTc correlated to its precursor activity demonstrates a secular equilibrium providing 2 Ci in a operational time of 150 h. As conclusion, the investigated nuclear and electromagnetic features have demonstrated that such generator shall have a notable potential for feeding the 99mTc clinical application.

Gravitational radiation from rapidly rotating nascent neutron stars

NASA Technical Reports Server (NTRS)

Lai, Dong; Shapiro, Stuart L.

1995-01-01

We study the secular evolution and gravitational wave signature of a newly formed, rapidly rotating neutron star. The neutron star may arise from core collapse in a massive star or from the accretion-induced collapse of a white dwarf. After a brief dynamical phase, the nascent neutron star settles into an axisymmetric, secularly unstable state. Gravitational radiation drives the star to a nonaxisymmetric, stationary equilibrium configuration via the bar-mode instability. The emitted quasi-periodic gravitational waves have a unique signature: the wave frequency sweeps downward from a few hundred Hertz to zero, while the wave amplitude increase from zero to a maximum and then decays back to zero. Such a wave signal could detected by broadband gravitational wave interferometers currently being constructed. We also characterize two other types of gravitational wave signals that could arise in principle from a rapidly rotating, secularly unstable neutron star: a high-frequency (f greater than or approximately = 1000 Hz) wave which increases the pattern-speed of the star, and a wave that actually increases the angular momentum of the star.

Predicted torque equilibrium attitude utilization for Space Station attitude control

NASA Technical Reports Server (NTRS)

Kumar, Renjith R.; Heck, Michael L.; Robertson, Brent P.

1990-01-01

An approximate knowledge of the torque equilibrium attitude (TEA) is shown to improve the performance of a control moment gyroscope (CMG) momentum management/attitude control law for Space Station Freedom. The linearized equations of motion are used in conjunction with a state transformation to obtain a control law which uses full state feedback and the predicted TEA to minimize both attitude excursions and CMG peak and secular momentum. The TEA can be computationally determined either by observing the steady state attitude of a 'controlled' spacecraft using arbitrary initial attitude, or by simulating a fixed attitude spacecraft flying in desired orbit subject to realistic environmental disturbance models.

Successes and Techniques Associated with Teaching the Chemistry of Radioactive Wastes.

ERIC Educational Resources Information Center

Williams, Donald H.

1995-01-01

Describes a chemistry course that is built around the topic of radioactive waste and encompasses a large number of chemistry concepts including redox, equilibrium, kinetics, nuclear energy, and the periodic chart. (JRH)

Treatment of radioactive liquid waste (Co-60) by sorption on Zeolite Na-A prepared from Iraqi kaolin.

PubMed

Mustafa, Yasmen A; Zaiter, Maysoon J

2011-11-30

Iraqi synthetic zeolite type Na-A has been suggested as ion exchange material to treat cobalt-60 in radioactive liquid waste which came from neutron activation for corrosion products. Batch experiments were conducted to find out the equilibrium isotherm for source sample. The equilibrium isotherm for radioactive cobalt in the source sample showed unfavorable type, while the equilibrium isotherm for the total cobalt (the radioactive and nonradioactive cobalt) in the source sample showed a favorable type. The ability of Na-A zeolite to remove cobalt from wastewater was checked for high cobalt concentration (822 mg/L) in addition to low cobalt concentration in the source sample (0.093 mg/L). A good fitting for the experimental data with Langmuir equilibrium model was observed. Langmuir constant qm which is related to monolayer adsorption capacity for low and high cobalt concentration was determined to be 0.021 and 140 mg/g(zeolite). The effects of important design variables on the zeolite column performance were studied these include initial concentration, flow rate, and bed depth. The experimental results have shown that high sorption capacity can be obtained at high influent concentration, low flow rate, and high bed depth. Higher column performance was obtained at higher bed depth. Thomas model was employed to predict the breakthrough carves for the above variables. A good fitting was observed with correlation coefficients between 0.915 and 0.985. Copyright © 2011 Elsevier B.V. All rights reserved.

Radioactive equilibrium in ancient marine sediments

USGS Publications Warehouse

Breger, I.A.

1955-01-01

Radioactive equilibrium in eight marine sedimentary formations has been studied by means of direct determinations of uranium, radium and thorium. Alpha-particle counting has also been carried out in order to cross-calibrate thick-source counting techniques. The maximum deviation from radioactive equilibrium that has been noted is 11 per cent-indicating that there is probably equilibrium in all the formations analyzed. Thick-source alpha-particle counting by means of a proportional counter or an ionization chamber leads to high results when the samples contain less than about 10 p.p.m. of uranium. For samples having a higher content of uranium the results are in excellent agreement with each other and with those obtained by direct analytical techniques. The thorium contents that have been obtained correspond well to the average values reported in the literature. The uranium content of marine sediments may be appreciably higher than the average values that have been reported for sedimentary rocks. Data show that there is up to fourteen times the percentage of uranium as of thorium in the formations studied and that the percentage of thorium never exceeds that of uranium. While the proximity of a depositional environment to a land mass may influence the concentration of uranium in a marine sediment, this is not true with thorium. ?? 1955.

Geochemistry of uranium and thorium and natural radioactivity levels of the western Anatolian plutons, Turkey

NASA Astrophysics Data System (ADS)

Papadopoulos, Argyrios; Altunkaynak, Şafak; Koroneos, Antonios; Ünal, Alp; Kamaci, Ömer

2017-10-01

Seventy samples from major plutons (mainly granitic) of Western Anatolia (Turkey) have been analyzed by γ-ray spectrometry to determine the specific activities of 238U, 226Ra, 232Th and 40K (Bq/kg). Τhe natural radioactivity ranged up to 264 Bq/kg for 238U, 229.62 Bq/kg for 226Ra, up to 207.32 Bq/kg for 232Th and up to 2541.95 Bq/kg for 40K. Any possible relationship between the specific activities of 226Ra, 238U, 232Th and 40K and some characteristics of the studied samples (age, rock-type, colour, grain size, occurrence, chemical and mineralogical composition) was investigated. Age, major and trace element geochemistry, color, pluton location and mineralogical composition are likely to affect the concentrations of the measured radionuclides. The range of the Th/U ratio was large (0.003-11.374). The latter, along with 226Ra/238U radioactive secular disequilibrium, is also discussed and explained by magmatic processes during differentiation.

Equilibrium, stability, and orbital evolution of close binary systems

NASA Technical Reports Server (NTRS)

Lai, Dong; Rasio, Frederic A.; Shapiro, Stuart L.

1994-01-01

We present a new analytic study of the equilibrium and stability properties of close binary systems containing polytropic components. Our method is based on the use of ellipsoidal trial functions in an energy variational principle. We consider both synchronized and nonsynchronized systems, constructing the compressible generalizations of the classical Darwin and Darwin-Riemann configurations. Our method can be applied to a wide variety of binary models where the stellar masses, radii, spins, entropies, and polytropic indices are all allowed to vary over wide ranges and independently for each component. We find that both secular and dynamical instabilities can develop before a Roche limit or contact is reached along a sequence of models with decreasing binary separation. High incompressibility always makes a given binary system more susceptible to these instabilities, but the dependence on the mass ratio is more complicated. As simple applications, we construct models of double degenerate systems and of low-mass main-sequence star binaries. We also discuss the orbital evoltuion of close binary systems under the combined influence of fluid viscosity and secular angular momentum losses from processes like gravitational radiation. We show that the existence of global fluid instabilities can have a profound effect on the terminal evolution of coalescing binaries. The validity of our analytic solutions is examined by means of detailed comparisons with the results of recent numerical fluid calculations in three dimensions.

Wind Transport of Radionuclide- Bearing Dust, Peña Blanca, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Velarde, R.; Goodell, P. C.; Gill, T. E.; Arimoto, R.

2007-05-01

This investigation evaluates radionuclide fractionation during wind erosion of high-grade uranium ore storage piles at Peña Blanca (50km north of Chihuahua City), Chihuahua, Mexico. The aridity of the local environment promotes dust resuspension by high winds. Although active operations ceased in 1983, the Peña Blanca mining district is one of Mexico`s most important uranium ore reserves. The study site contains piles of high grade ore, left loose on the surface, and separated by the specific deposits from which they were derived (Margaritas, Nopal I, and Puerto I). Similar locations do not exist in the United States, since uranium mining sites in the USA have been reclaimed. The Peña Blanca site serves as an analog for the Yucca Mountain project. Dust deposition is collected at Peña Blanca with BSNE sediment catchers (Fryrear, 1986) and marble dust traps (Reheis, 1999). These devices capture windblown sediment; subsequently, the sample data will help quantify potentially radioactive short term field sediment loss from the repository surface and determine sediment flux. Aerosols and surface materials will be analyzed and radioactivity levels established utilizing techniques such as gamma spectroscopy. As a result, we will be able to estimate how much radionuclide contaminated dust is being transported or attached geochemically to fine grain soils or minerals (e.g., clays or iron oxides). The high-grade uranium-bearing material is at secular equilibrium, thus the entire decay series is present. Of resulting interest is not only the aeolian transport of uranium, but also of the other daughter products. These studies will improve our understanding of geochemical cycling of radionuclides with respect to sources, transport, and deposition. The results may also have important implications for the geosciences and homeland security, and potential applications to public health. Funding for this project is provided in part via a NSF grant to Arimoto.

The Dominance of Dynamic Barlike Instabilities in the Evolution of a Massive Stellar Core Collapse That ``Fizzles''

NASA Astrophysics Data System (ADS)

Imamura, James N.; Durisen, Richard H.

2001-03-01

Core collapse in a massive rotating star may halt at subnuclear density if the core contains angular momentum J>~1049 g cm2 s-1. An aborted collapse can lead to the formation of a rapidly rotating equilibrium object, which, because of its high electron fraction, Ye>0.4, and high entropy per baryon, Sb/k~1-2, is secularly and dynamically stable. The further evolution of such a ``fizzler'' is driven by deleptonization and cooling of the hot, dense material. These processes cause the fizzler both to contract toward neutron star densities and to spin up, driving it toward instability points of the barlike modes. Using linear stability analyses to study the latter case, we find that the stability properties of fizzlers are similar to those of Maclaurin spheroids and polytropes despite the nonpolytropic nature and extreme compressibility of the fizzler equation of state. For fizzlers with the specific angular momentum distribution of the Maclaurin spheroids, secular and dynamic barlike instabilities set in at T/|W|~0.14 and 0.27, respectively, where T is the rotational kinetic energy and W is the gravitational energy of the fizzler, the same limits as found for Maclaurin spheroids. For fizzlers in which angular momentum is more concentrated toward the equator, the secular stability limits drop dramatically. For the most extreme angular momentum distribution we consider, the secular stability limit for the barlike modes falls to T/|W|~0.038, compared with T/|W|~0.09-0.10 for the most extreme polytropic cases known previously (Imamura et al.). For fixed equation-of-state parameters, the secular and dynamic stability limits occur at roughly constant mass over the range of typical fizzler central densities. Deleptonization and cooling decrease the limiting masses on timescales shorter than the growth time for secular instability. Consequently, unless an evolving fizzler reaches neutron star densities first, it will always encounter dynamic barlike instabilities before secular instabilities have time to grow. Quasi-linear analysis shows that the angular momentum loss during the early nonlinear evolution of the dynamic barlike instability is dominated by Newtonian self-interaction gravitational torques rather than by the emission of gravitational wave (GW) radiation. GW emission may dominate after the initial dynamic evolutionary phase ends. Nonlinear hydrodynamics simulations with a proper equation of state will be required to determine the ultimate outcome of such evolutions and to refine predictions of GW production by barlike instabilities.

Radioactivity, radiological risk and metal pollution assessment in marine sediments from Calabrian selected areas, southern Italy

NASA Astrophysics Data System (ADS)

Caridi, F.; Messina, M.; Faggio, G.; Santangelo, S.; Messina, G.; Belmusto, G.

2018-02-01

The two most significant categories of physical and chemical pollutants in sediments (radionuclides and metals) were investigated in this article, in order to evaluate pollution levels in marine sediments from eight different selected sites of the Calabria region, south of Italy. In particular samples were analyzed to determine natural and anthropic radioactivity and metal concentrations, in order to assess any possible radiological hazard, the level of contamination and the possible anthropogenic impact in the investigated area. Activity concentrations of 226Ra, 232Th, 40K and 137Cs were measured by High Purity Germanium (HPGe) gamma spectrometry. The obtained results show that, for radium (in secular equilibrium with uranium), the specific activity ranges from ( 14 ± 1) Bq/kg dry weight (d.w.) to ( 54 ± 9) Bq/kg d.w.; for thorium, from ( 12 ± 1) Bq/kg d.w. to ( 83 ± 8) Bq/kg d.w.; for potassium, from ( 470 ± 20) Bq/kg d.w. to ( 1000 ± 70) Bq/kg d.w. and for cesium it is lower than the minimum detectable activity value. The absorbed gamma dose rate in air (D), the annual effective dose equivalent (AEDE) outdoor and the external hazard index ( H_ex) were calculated to evaluate any possible radiological risk, mainly due to the use of marine sediments for the beach nourishment. The results show low levels of radioactivity, thus discarding any significant radiological risk. Some metals (As, Cd, Cr tot, Hg, Ni, Pb, Cu, Zn, Mn and Fe), that could be released into the environment by both natural and anthropogenic sources, were investigated through inductively coupled plasma mass spectrometry (ICP-MS) measurements and compared with the limits set by the Italian Legislation, to assess any possible contamination. Experimental results show that they are much lower than the contamination threshold value, thus excluding their presence as pollutants. The degree of sediment contaminations were quantified using enrichment factor ( EF) and geoaccumulation index ( I geo) for some potential hazardous elements. Results show that EF and I geo values of As, Pb and Mn were the greatest among the studied metals. Data of this preliminary study could be helpful in the future to obtain background levels in marine sediments of the investigated region and to develop environmental regulatory frameworks.

Using Beads and Divided Containers to Study Kinetic and Equilibrium Isotope Effects in the Laboratory and in the Classroom

ERIC Educational Resources Information Center

Campbell, Dean J.; Brewer, Emily R.; Martinez, Keri A.; Fitzjarrald, Tamara J.

2017-01-01

The purpose of this laboratory experiment is to study fundamental concepts of kinetics and equilibria and the isotope effects associated with both of these concepts. The concepts of isotopes in introductory and general chemistry courses are typically used within the contexts of atomic weights and radioactivity. Kinetic and equilibrium isotope…

Determination of (241)Pu by the method of disturbed radioactive equilibrium using 2πα-counting and precision gamma-spectrometry.

PubMed

Alekseev, I; Kuzmina, T

2016-04-01

A simple technique is proposed for the determination of the content of (241)Pu, which is based on disturbance of radioactive equilibrium in the genetically related (237)U←(241)Pu→(241)Am decay chain of radionuclides, with the subsequent use of 2πα-counting and precision gamma-spectroscopy for monitoring the process of restoration of that equilibrium. It has been shown that the data on dynamics of accumulation of the daughter (241)Am, which were obtained from the results of measurements of α- and γ-spectra of the samples, correspond to the estimates calculated for the chain of two genetically related radionuclides, the differences in the estimates of (241)Pu radioactivity not exceeding 2%. Combining the different methods of registration (2πα-counting, semiconductor alpha- and gamma-spectrometry) enables the proposed method to be efficiently applied both for calibration of (241)Pu-sources (from several hundreds of kBq and higher) and for radioisotopic analysis of plutonium mixtures. In doing so, there is a deep purification of (241)Pu from its daughter decay products required due to unavailability of commercial detectors that could make it possible, based only on analysis of alpha-spectra, to conduct quantitative analysis of the content of (238)Pu and (241)Am. Copyright © 2016 Elsevier Ltd. All rights reserved.

The Study of Equilibrium factor between Radon-222 and its Daughters in Bangkok Atmosphere by Gamma-ray Spectrometry

NASA Astrophysics Data System (ADS)

Rujiwarodom, Rachanee

2010-05-01

To study the Equilibrium between radon-222 and its daughters in Bangkok atmosphere by Gamma-ray spectrometry, air sample were collected on 48 activated charcoal canister and 360 glass fiber filters by using a high volume jet-air sampler during December 2007 to November 2008.The Spectra of gamma-ray were measured by using a HPGe (Hyper Pure Germanium Detector). In the condition of secular equilibrium obtaining between Radon-222 and its decay products, radon-222 on activated charcoal canister and its daughters on glass fiber filters collected in the same time interval were calculated. The equilibrium factor (F) in the open air had a value of 0.38 at the minimum ,and 0.75 at the maximum. The average value of equilibrium factor (F) was 0.56±0.12. Based on the results, F had variations with a maximum value in the night to the early morning and decreased in the afternoon. In addition, F was higher in the winter than in the summer. This finding corresponds with the properties of the Earth atmosphere. The equilibrium factor (F) also depended on the concentration of dust in the atmosphere. People living in Bangkok were exposed to average value of 30 Bq/m3 of Radon-222 in the atmosphere. The equilibrium factor (0.56±0.12) and the average value of Radon-222 showed that people were exposed to alpha energy from radon-222 and its daughters decay at 0.005 WL(Working Level) which is lower than the safety standard at 0.02 WL. Keywords: Radon, Radon daughters , equilibrium factor, Gamma -ray spectrum analysis ,Bangkok ,Thailand

(234)U/(238)U signatures associated with uranium ore bodies: part 3 Koongarra.

PubMed

Lowson, Richard T

2013-04-01

The Koongarra ore body is an early Proterozoic U ore body in the Alligator Rivers U province, Northern Territory, Australia. It has surface expression with a redox front located ∼30 m below the surface. The (234)U/(238)U activity ratios (AR) for the ground water and the amorphous phase of the solid have been analysed for the ore zone and dispersion halo as a function of depth. The results display a (234)U/(238)U AR signature with depth which may be common to all U ore bodies. The (234)U/(238)U AR is depressed below secular equilibrium in the weathered material above the redox front; rises significantly above secular equilibrium in the vicinity of the redox front; and is followed by a gradual decrease with depth below the redox front. The amplitude of the profile is a function of local conditions. A model is proposed for the signature in which oxidising waters preferentially leach the (234)U sites at the redox front due to preconditioning of the (234)U sites by α recoil during the decay of (23)(8)U to (23)(4)U. Mass balance requires the solid material left behind the redox front to have a (234)U/(238)U AR reduced below 1. Local second order effects may be superimposed on the signature. The signature may have application to calibrating scenarios for nuclear waste repositories, assisting in understanding historical climates, economic evaluation of U ore bodies and U exploration. Copyright © 2012 Elsevier Ltd. All rights reserved.

Stellar dynamics around a massive black hole - II. Resonant relaxation

NASA Astrophysics Data System (ADS)

Sridhar, S.; Touma, Jihad R.

2016-06-01

We present a first-principles theory of resonant relaxation (RR) of a low-mass stellar system orbiting a more massive black hole (MBH). We first extend the kinetic theory of Gilbert to include the Keplerian field of a black hole of mass M•. Specializing to a Keplerian stellar system of mass M ≪ M•, we use the orbit-averaging method of Sridhar & Touma to derive a kinetic equation for RR. This describes the collisional evolution of a system of N ≫ 1 Gaussian rings in a reduced 5-dim space, under the combined actions of self-gravity, 1 post-Newtonian (PN) and 1.5 PN relativistic effects of the MBH and an arbitrary external potential. In general geometries, RR is driven by both apsidal and nodal resonances, so the distinction between scalar RR and vector RR disappears. The system passes through a sequence of quasi-steady secular collisionless equilibria, driven by irreversible two-ring correlations that accrue through gravitational interactions, both direct and collective. This correlation function is related to a `wake function', which is the linear response of the system to the perturbation of a chosen ring. The wake function is easier to appreciate, and satisfies a simpler equation, than the correlation function. We discuss general implications for the interplay of secular dynamics and non-equilibrium statistical mechanics in the evolution of Keplerian stellar systems towards secular thermodynamic equilibria, and set the stage for applications to the RR of axisymmetric discs in Paper III.

A combined radio- and stable-isotopic study of a California coastal aquifer system

USGS Publications Warehouse

Swarzenski, Peter W.; Baskaran, Mark; Rosenbauer, Robert J.; Edwards, Brian D.; Land, Michael

2013-01-01

Stable and radioactive tracers were utilized in concert to characterize geochemical processes in a complex coastal groundwater system and to provide constraints on the kinetics of rock/water interactions. Groundwater samples from wells within the Dominguez Gap region of Los Angeles County, California were analyzed for a suite of major cations (Na+, K+, Mg2+, Ca2+) and anions (Cl−, SO42−), silica, alkalinity, select trace elements (Ba, B, Sr), dissolved oxygen, stable isotopes of hydrogen (δD), oxygen (δ18O), dissolved inorganic carbon (δ13CDIC), and radioactive isotopes (3H, 222Rn and 223,224,226,228Ra). In the study area, groundwater may consist of a complex mixture of native groundwater, intruded seawater, non-native injected water, and oil-field brine water. In some wells, Cl− concentrations attained seawater-like values and in conjunction with isotopically heavier δ18O values, these tracers provide information on the extent of seawater intrusion and/or mixing with oil-field brines. Groundwater 3H above 1 tritium unit (TU) was observed only in a few select wells close to the Dominguez Gap area and most other well groundwater was aged pre-1952. Based on an initial 14C value for the study site of 90 percent modern carbon (pmc), groundwater age estimates likely extend beyond 20 kyr before present and confirm deep circulation of some native groundwater through multiple aquifers. Enriched values of groundwater δ13CDIC in the absence of SO42− imply enhanced anaerobic microbial methanogenesis. While secular equilibrium was observed for 234U/238U (activity ratios ~1) in host matrices, strong isotopic fractionation in these groundwater samples can be used to obtain information of adsorption/desorption kinetics. Calculated Ra residence times are short, and the associated desorption rate constant is about three orders of magnitude slower than that of the adsorption rate constant. Combined stable- and radio-isotopic results provide unique insights into aquifer characteristics, such as geochemical cycling, rock/water interactions, and subsurface transport and mixing.

Radiation protection and radioactive scales in oil and gas production.

PubMed

Testa, C; Desideri, D; Meli, M A; Roselli, C; Bassignani, A; Colombo, G; Fantoni, R F

1994-07-01

Low specific-activity scales consisting of alkaline earth metal carbonates and sulfates are often present in some gaseous and liquid hydrocarbon plants. These scales contain a certain concentration of radium, uranium, and thorium which can cause a risk of gamma irradiation and internal radiocontamination when they must be mechanically removed. The gamma dose rates and the 238U, 232Th, 226Ra concentrations were determined in sludges, scales, and waters of some gas and oil hydrocarbon plants located in Italy, Congo, and Tunisia. 238U and 232Th concentrations were were low. The isotopes 238U and 234U resulted in radioactive equilibrium, while 232Th and 228Th were not always equilibrium. A rough correlation was found between the gamma dose rate and the 226Ra concentration. Some considerations and conclusions about radiation protection problems are pointed out.

Measurement of Radon in Indoor Air.

ERIC Educational Resources Information Center

Downey, Daniel M.; Simolunas, Glenn

1988-01-01

Describes a laboratory experiment to teach the principles of air sampling, gamma ray spectroscopy, nuclear decay, and radioactive equilibrium. Analyzes radon by carbon adsorption and gamma ray counting. Provides methodology and rate of decay equations. (MVL)

Determination of strontium-90 from direct separation of yttrium-90 by solid phase extraction using DGA Resin for seawater monitoring.

PubMed

Tazoe, Hirofumi; Obata, Hajime; Yamagata, Takeyasu; Karube, Zin'ichi; Nagai, Hisao; Yamada, Masatoshi

2016-05-15

It is important for public safety to monitor strontium-90 in aquatic environments in the vicinity of nuclear related facilities. Strontium-90 concentrations in seawater exceeding the background level have been observed in accidents of nuclear facilities. However, the analytical procedure for measuring strontium-90 in seawater is highly demanding. Here we show a simple and high throughput analytical technique for the determination of strontium-90 in seawater samples using a direct yttrium-90 separation. The DGA Resin is used to determine the abundance of strontium-90 by detecting yttrium-90 decay (beta-emission) in secular equilibrium. The DGA Resin can selectively collect yttrium-90 and remove naturally occurring radionuclides such as (40)K, (210)Pb, (214)Bi, (238)U, and (232)Th and anthropogenic radionuclides such as (140)Ba, and (140)La. Through a sample separation procedure, a high chemical yield of yttrium-90 was achieved at 95.5±2.3%. The result of IAEA-443 certified seawater analysis (107.7±3.4 mBq kg(-1)) was in good agreement with the certified value (110±5 mBq kg(-1)). By developed method, we can finish analyzing 8 samples per day after achieving secular equilibrium, which is a reasonably fast throughput in actual seawater monitoring. By processing 3 L of seawater sample and applying a counting time of 20 h, minimum detectable activity can be as low as 1.5 mBq kg(-1), which could be applied to monitoring for the contaminated marine environment. Reproducibility was found to be 3.4% according to 10 independent analyses of natural seawater samples from the vicinity of the Fukushima Daiichi Nuclear Power Plant in September 2013. Copyright © 2016 Elsevier B.V. All rights reserved.

The two-stage dynamics in the Fermi-Pasta-Ulam problem: From regular to diffusive behavior

NASA Astrophysics Data System (ADS)

Ponno, A.; Christodoulidi, H.; Skokos, Ch.; Flach, S.

2011-12-01

A numerical and analytical study of the relaxation to equilibrium of both the Fermi-Pasta-Ulam (FPU) α-model and the integrable Toda model, when the fundamental mode is initially excited, is reported. We show that the dynamics of both systems is almost identical on the short term, when the energies of the initially unexcited modes grow in geometric progression with time, through a secular avalanche process. At the end of this first stage of the dynamics, the time-averaged modal energy spectrum of the Toda system stabilizes to its final profile, well described, at low energy, by the spectrum of a q-breather. The Toda equilibrium state is clearly shown to describe well the long-living quasi-state of the FPU system. On the long term, the modal energy spectrum of the FPU system slowly detaches from the Toda one by a diffusive-like rising of the tail modes, and eventually reaches the equilibrium flat shape. We find a simple law describing the growth of tail modes, which enables us to estimate the time-scale to equipartition of the FPU system, even when, at small energies, it becomes unobservable.

The innate origin of radial and vertical gradients in a simulated galaxy disc

NASA Astrophysics Data System (ADS)

Navarro, Julio F.; Yozin, Cameron; Loewen, Nic; Benítez-Llambay, Alejandro; Fattahi, Azadeh; Frenk, Carlos S.; Oman, Kyle A.; Schaye, Joop; Theuns, Tom

2018-05-01

We examine the origin of radial and vertical gradients in the age/metallicity of the stellar component of a galaxy disc formed in the APOSTLE cosmological hydrodynamical simulations. Some of these gradients resemble those in the Milky Way, where they have sometimes been interpreted as due to internal evolution, such as scattering off giant molecular clouds, radial migration driven by spiral patterns, or orbital resonances with a bar. Secular processes play a minor role in the simulated galaxy, which lacks strong spiral or bar patterns, and where such gradients arise as a result of the gradual enrichment of a gaseous disc that is born thick but thins as it turns into stars and settles into centrifugal equilibrium. The settling is controlled by the feedback of young stars; which links the star formation, enrichment, and equilibration time-scales, inducing radial and vertical gradients in the gaseous disc and its descendent stars. The kinematics of coeval stars evolve little after birth and provide a faithful snapshot of the gaseous disc structure at the time of their formation. In this interpretation, the age-velocity dispersion relation would reflect the gradual thinning of the disc rather than the importance of secular orbit scattering; the outward flaring of stars would result from the gas disc flare rather than from radial migration; and vertical gradients would arise because the gas disc gradually thinned as it enriched. Such radial and vertical trends might just reflect the evolving properties of the parent gaseous disc, and are not necessarily the result of secular evolutionary processes.

Bar Mode Instability in Relativistic Rotating Stars: A Post-Newtonian Treatment

NASA Astrophysics Data System (ADS)

Shapiro, Stuart L.; Zane, Silvia

1998-08-01

We construct analytic models of incompressible, uniformly rotating stars in post-Newtonian (PN) gravity and evaluate their stability against nonaxisymmetric bar modes. We model the PN configurations by homogeneous triaxial ellipsoids and employ an energy variational principle to determine their equilibrium shape and stability. The spacetime metric is obtained by solving Einstein's equations of general relativity in 3 + 1 ADM form. We use an approximate subset of these equations well suited to numerical integration in the case of strong-field, three-dimensional configurations in quasi equilibrium. However, the adopted equations are exact at PN order, where they admit an analytic solution for homogeneous ellipsoids. We obtain this solution for the metric, as well as analytic functionals for the conserved global quantities, M, M0, and J. We present sequences of axisymmetric, rotating equilibria of constant density and rest mass parametrized by their eccentricity. These configurations represent the PN generalization of Newtonian Maclaurin spheroids, which we compare to other PN and full relativistic incompressible equilibrium sequences constructed by previous investigators. We employ the variational principle to consider nonaxisymmetric ellipsoidal deformations of the configurations, holding the angular momentum constant and the rotation uniform. We locate the point along each sequence at which these Jacobi-like bar modes will be driven secularly unstable by the presence of a dissipative agent such as viscosity. We find that the value of the eccentricity, as well as related ratios such as Ω2/(πρ0) and T/|W| (=rotational kinetic energy/gravitational potential energy), defined invariantly, all increase at the onset of instability as the stars become more relativistic. Since higher degrees of rotation are required to trigger a viscosity-driven bar mode instability as the stars become more compact, the effect of general relativity is to weaken the instability, at least to PN order. This behavior is in stark contrast to that found recently for secular instability via nonaxisymmetric, Dedekind-like modes driven by gravitational radiation. These findings support the suggestion that in general relativity nonaxisymmetric modes driven unstable by viscosity no longer coincide with those driven unstable by gravitational radiation.

Hydrodynamical processes in coalescing binary stars

NASA Astrophysics Data System (ADS)

Lai, Dong

1994-01-01

Coalescing neutron star binaries are considered to be the most promising sources of gravitational waves that could be detected by the planned laser-interferometer LIGO/VIRGO detectors. Extracting gravity wave signals from noisy data requires accurate theoretical waveforms in the frequency range 10-1000 Hz end detailed understanding of the dynamics of the binary orbits. We investigate the quasi-equilibrium and dynamical tidal interactions in coalescing binary stars, with particular focus on binary neutron stars. We develop a new formalism to study the equilibrium and dynamics of fluid stars in binary systems. The stars are modeled as compressible ellipsoids, and satisfy polytropic equation of state. The hydrodynamic equations are reduced to a set of ordinary differential equations for the evolution of the principal axes and other global quantities. The equilibrium binary structure is determined by a set of algebraic equations. We consider both synchronized and nonsynchronized systems, obtaining the generalizations to compressible fluid of the classical results for the ellipsoidal binary configurations. Our method can be applied to a wide variety of astrophysical binary systems containing neutron stars, white dwarfs, main-sequence stars and planets. We find that both secular and dynamical instabilities can develop in close binaries. The quasi-static (secular) orbital evolution, as well as the dynamical evolution of binaries driven by viscous dissipation and gravitational radiation reaction are studied. The development of the dynamical instability accelerates the binary coalescence at small separation, leading to appreciable radial infall velocity near contact. We also study resonant excitations of g-mode oscillations in coalescing binary neutron stars. A resonance occurs when the frequency of the tidal driving force equals one of the intrinsic g-mode frequencies. Using realistic microscopic nuclear equations of state, we determine the g-modes in a cold neutron atar. Resonant excitations of these g-modes during the last few minutes of the binary coalescence result in energy transfer and angular momentum transfer from the binary orbit to the neutron star. Because of the weak coupling between the g-modes and the tidal potential, the induced orbital phase errors due to resonances are small. However, resonant excitations of the g-modes play an important role in the tidal heating of binary neutron stars.

Radio-tracer techniques for the study of flow in saturated porous materials

USGS Publications Warehouse

Skibitzke, H.E.; Chapman, H.T.; Robinson, G.M.; McCullough, Richard A.

1961-01-01

An experiment was conducted by the U.S. Geological Survey to determine the feasibility of using a radioactive substance as a tracer in the study of microscopic flow in a saturated porous solid. A radioactive tracer was chosen in preference to dye or other chemical in order to eliminate effects of the tracer itself on the flow system such as those relating to density, viscosity and surface tension. The porous solid was artificial "sandstone" composed of uniform fine grains of sand bonded together with an epoxy adhesive. The sides of the block thus made were sealed with an epoxy coating compound to insure water-tightness. Because of the chemical inertness of the block it was possible to use radioactive phosphorus (P32). Ion-exchange equilibrium was created between the block and nonradioactive phosphoric acid. Then a tracer tagged with P32 was injected into the block in the desired geometric configuration, in this case, a line source. After equilibrium in isotopic exchange was reached between the block and the line source, the block was rinsed, drained and sawn into slices. It was found that a quantitative analysis of the flow system may be made by assaying the dissected block. ?? 1961.

Platelet-derived-growth-factor-stimulated heterogeneous polyphosphoinositide metabolism and phosphate uptake in C3H fibroblasts.

PubMed Central

Holmsen, H; Male, R; Rongved, S; Langeland, N; Lillehaug, J

1989-01-01

Pig platelet-derived growth factor (PDGF) increased the rate of [32P]Pi uptake by murine fibroblasts, resulting in a 3-9-fold elevation of the specific radioactivity of ATP, PtdInsP, PtdInsP2, PtdIns and phosphatidic acid. The specific radioactivity was 10-60-fold higher in ATP than in the four phospholipids. These substances are therefore not in metabolic equilibrium, which complicates determination of inositol phospholipid turnover. PMID:2548480

Geochronology of recent sediments from the Cariaco Trench (Venezuela) by Alpha Spectrometry of {sup 210}Pb ({sup 210}Po)

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

Arriojas, A.; Barros, H.; Palacios, D.

2010-08-04

210Pb concentration in marine sediments of the Cariaco Trench (North-East of Venezuela) was measured through the analysis of 210Po alpha emissions, which can be assumed to be in secular equilibrium with 210Pb. The analysed sediment core has a length of 1.9 m. The results allowed to apply the CF:CS dating model (Constant Flux and Constant Supply). The sedimentation rate was estimated to be 0.25 cm/y. As far as we know this is the first {alpha}- dating carried out in the country, performed with an alpha spectrometer recently funded by the IAEA.

Computer Series, 67: Bits and Pieces, 27.

ERIC Educational Resources Information Center

Moore, John W., Ed.

1986-01-01

Discusses a computer interfacing course using Commodore 64 microcomputers; a computer program for radioactive equilibrium; analysis of near infrared spectrum of hydrochloric acid molecules using Apple II microcomputers; microcomputer approach to conductivity titrations; balancing equations with Commodore 64's; formulation of mathematical…

Adsorption of cesium on cement mortar from aqueous solutions.

PubMed

Volchek, Konstantin; Miah, Muhammed Yusuf; Kuang, Wenxing; DeMaleki, Zack; Tezel, F Handan

2011-10-30

The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L(-1) and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive (137)Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy. Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837 mg L(-1) while the respective surface concentration on coupons varied from 0.0395 to 22.34 μg cm(-2). Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol(-1) suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar. Crown Copyright © 2011. Published by Elsevier B.V. All rights reserved.

Geoscience parameter data base handbook: granites and basalts

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

Not Available

1979-12-01

The Department of Energy has the responsibility for selecting and constructing Federal repositories for radioactive waste. The Nuclear Regulatory Commission must license such repositories prior to construction. The basic requirement in the geologic disposal of radioactive waste is stated as: placement in a geologic host whereby the radioactive waste is not in mechanical, thermal or chemical equilibrium with the object of preventing physical or chemical migration of radionuclides into the biosphere or hydrosphere in hazardous concentration (USGS, 1977). The object of this report is to document the known geologic parameters of large granite and basalt occurrences in the coterminous Unitedmore » States, for future evaluation in the selection and licensing of radioactive waste repositories. The description of the characteristics of certain potential igneous hosts has been limited to existing data pertaining to the general geologic character, geomechanics, and hydrology of identified occurrences. A description of the geochemistry is the subject of a separate report.« less

The Incidence and Management of Conflicts in Secular and Non-Secular Tertiary Institutions in South West Nigeria

ERIC Educational Resources Information Center

Ayodele, Joseph Babatola; Adewumi, Joseph Olukayode

2007-01-01

This paper compared the incidence and management of conflicts in secular and non-secular tertiary institutions in Nigeria. The sample of this study was made of sixty staff, and two hundred and forty students randomly selected each from two secular and two non-secular tertiary institutions in south western Nigeria. A validated questionnaire was…

A new nuclide transport model in soil in the GENII-LIN health physics code

NASA Astrophysics Data System (ADS)

Teodori, F.

2017-11-01

The nuclide soil transfer model, originally included in the GENII-LIN software system, was intended for residual contamination from long term activities and from waste form degradation. Short life nuclides were supposed absent or at equilibrium with long life parents. Here we present an enhanced soil transport model, where short life nuclide contributions are correctly accounted. This improvement extends the code capabilities to handle incidental release of contaminant to soil, by evaluating exposure since the very beginning of the contamination event, before the radioactive decay chain equilibrium is reached.

Performance and modeling of cesium ion exchange by ENGI neered form crystalline silicotitanates

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

Anthony, R.G.; Gu, D.; Huckman, M.

1996-10-01

TAM-5, a hydrous crystalline silicotitanate (CST) powder developed by Sandia National Laboratories and Texas A&M University, and commercialized by UOP as IONSIV{reg_sign} Ion Exchanger Type IE-910, is a highly selective material for removing cesium and strontium from aqueous radioactive wastes such as those found at the Hanford site in Washington. An engineered form of the material suitable for column ion exchange type operations has been developed and tested. Data relevant to processing radioactive tank wastes including equilibrium distribution coefficients and column testing will be presented. The impact of exposure of the engineered form to chemically aggressive environments such as itmore » might experience during waste processing, and to the less aggressive environments it might experience during post processing storage has been assessed. The thermal stability of the material has also been evaluated. The experimental results have been integrated with an effort to model the material`s equilibrium and kinetic behavior.« less

Determination of uranium isotopes in food and environmental samples by different techniques: a comparison.

PubMed

Forte, M; Rusconi, R; Margini, C; Abbate, G; Maltese, S; Badalamenti, P; Bellinzona, S

2001-01-01

The uranium concentration in 59 samples of bottled and tap water, mainly from northern Italy, was measured by different techniques. Results obtained by inductively coupled plasma mass spectrometry (ICP-MS), semiconductor alpha spectrometry and low level liquid scintillation counting with alpha/beta discrimination (LSC) have been compared. High resolution gamma spectrometry and semiconductor alpha spectrometry have been used to analyse uranium in a variety of organic and inorganic samples. Isotopic secular equilibrium in the 238U series may be lacking or hidden by auto-absorption phenomena, so caution should be used in evaluating gamma spectrometry data. Alpha spectrometry has also been used to ascertain the possible pollution from depleted uranium in the environment.

Secular resonances. [of asteroidal dynamics

NASA Technical Reports Server (NTRS)

Scholl, H.; Froeschle, CH.; Kinoshita, H.; Yoshikawa, M.; Williams, J. G.

1989-01-01

Theories and numerical experiments regarding secular resonances are reviewed. The basic dynamics and the positions of secular resonances are discussed, and secular perturbation theories for the nu16 resonance case, the nu6 resonance, and the nu5 resonance are addressed. What numerical experiments have revealed about asteroids located in secular resonances, the stability of secular resonances, variations of eccentricities and inclinations, and chaotic orbits is considered. Resonant transport of meteorites is discussed.

Secular instabilities of Keplerian stellar discs

NASA Astrophysics Data System (ADS)

Kaur, Karamveer; Kazandjian, Mher V.; Sridhar, S.; Touma, Jihad R.

2018-05-01

We present idealized models of a razor-thin, axisymmetric, Keplerian stellar disc around a massive black hole, and study non-axisymmetric secular instabilities in the absence of either counter-rotation or loss cones. These discs are prograde mono-energetic waterbags, whose phase-space distribution functions are constant for orbits within a range of eccentricities (e) and zero outside this range. The linear normal modes of waterbags are composed of sinusoidal disturbances of the edges of distribution function in phase space. Waterbags that include circular orbits (polarcaps) have one stable linear normal mode for each azimuthal wavenumber m. The m = 1 mode always has positive pattern speed and, for polarcaps consisting of orbits with e < 0.9428, only the m = 1 mode has positive pattern speed. Waterbags excluding circular orbits (bands) have two linear normal modes for each m, which can be stable or unstable. We derive analytical expressions for the instability condition, pattern speeds, growth rates, and normal mode structure. Narrow bands are unstable to modes with a wide range in m. Numerical simulations confirm linear theory and follow the non-linear evolution of instabilities. Long-time integration suggests that instabilities of different m grow, interact non-linearly, and relax collisionlessly to a coarse-grained equilibrium with a wide range of eccentricities.

The three principal secular resonances nu(5), nu(6), and nu(16) in the asteroidal belt

NASA Astrophysics Data System (ADS)

Froeschle, Ch.; Scholl, H.

1989-09-01

Theoretical and numerical results obtained for secular resonant motion in the asteroidal belt are reviewed. William's (1969) theory yields the locations of the principal secular resonances nu(5), Nu(6), and nu(16) in the asteroidal belt. Theories by Nakai and Kinoshita (1985) and by Yoshikawa (1987) make it possible to model the basic features of orbital evolution at the secular resonances nu(16) and nu(6), respectively. No theory is available for the secular resonance nu(5). Numerical experiments by Froeschle and Scholl yield quantitative and new qualitative results for orbital evolutions at the three principal secular resonances nu(5), nu(6), and nu(16). These experiments indicate possible chaotic motion due to overlapping resonances. A secular resonance may overlap with another secular resonance or with a mean motion resonance. The role of the secular resonances as possible sources of meteorites is discussed.

Compliance of Ultra-Orthodox and secular pedestrians with traffic lights in Ultra-Orthodox and secular locations.

PubMed

Rosenbloom, Tova; Shahar, Amit; Perlman, Amotz

2008-11-01

Following a previous study that revealed the disobedience of Ultra-Orthodox citizens, as compared to secular citizens, of traffic lights at crosswalks, the present study examined the road habits of 995 Ultra-Orthodox and secular pedestrians in neighboring Ultra-Orthodox and secular cities. Using an observation grid designed specially for this study, the pedestrians were observed at two crosswalks--one in an Ultra-Orthodox city and one in a secular city--as far as similar traffic parameters, using a logistic regression. The tendency to cross on a red light was assessed as a function of estimated age, gender, religiosity, location (religious/secular), the duration of the red light, the number of vehicles crossing and the number of pedestrians waiting at the curb. Ultra-Orthodox pedestrians committed more violations than secular pedestrians did, and there were more road violations in the Ultra-Orthodox location than there were in the secular location. Fewer traffic violations were committed by "local" pedestrians (Ultra-Orthodox pedestrians in the Ultra-Orthodox location and secular pedestrians in the secular location) than by "foreigners" (Ultra-Orthodox pedestrians in the secular location and secular pedestrians in the Ultra-Orthodox location). The odds of crossing on a red light decreased as a function of both the number of people waiting at the curb and the number of vehicles. Consistent with previous research, males crossed on red much more than females did, regardless of religiosity and location. Our discussion focuses on theoretical and practical explanations of the findings.

Equilibrium and Disequilibrium of 230Th-238U in Zircon from the Minoan Eruption, Santorini, Aegean Sea, Greece

NASA Astrophysics Data System (ADS)

Schmitt, A. K.; Stockli, D. F.; Song, E. J.; Storm, S.

2016-12-01

The Minoan eruption (ca. 1600 BCE; 40-80 km3 dense rock equivalent) occurred after a ca. 18 ka period of dormancy followed by rapid reinvigoration through arrival of new magma from deep reservoirs colliding with evolved magmas in shallow storage. Although zoned phenocrysts indicate brief timescales ranging between years to decades for final pre-eruptive magma recharge and mixing, it remains unclear how magma accumulation vs. crystallization were balanced in the subvolcanic reservoir during the preceding inter-eruptive cycle. To directly probe magma presence over the repose interval prior to the Minoan eruption and further back in time, we reconnoitered the potential of U-Th zircon geochronology to date the crystallization of individual zircon crystals from pumice from the Minoan eruption. Zircon crystals were extracted from composite pumice samples (several kg each) from basal fall out deposits using gravity and magnetic separation. Etching in cold HF removed adherent glass and revealed the shape of crystals, which were pressed into indium metal to expose unpolished rims to the ion beam of a CAMECA IMS 1270 secondary ionization mass spectrometer. Adherent glass was ubiquitous, indicating that crystals were in contact with melt at the time of eruption. Six of 18 crystals were in 230Th/238U secular equilibrium, two crystals yielded ages of ca. 160 ka, and the remaining rims dated between eruption age and ca. 20 ka. Low Th/U of some secular equilibrium zircon suggests recycling of metamorphic basement zircon, which is also indicated by the presence of rutile in heavy mineral separates. U-Th dates also reveal recycling of zircon from Pleistocene intrusions that likely represent left-over magma from antecedent eruption cycles. We tentatively interpret the dominant zircon population with near-eruption to ca. 20 ka ages to indicate continuous melt presence underneath Santorini during the last repose interval. Distinguishing a hiatus in zircon crystallization between 20 ka and 160 ka from continuous presence of a crystal mush capable of crystallizing zircon throughout the late Pleistocene requires further analyses. A corollary of mixed zircon populations of heterogeneous provenance in Minoan pumice is that the age significance of U-series data for major phases analyzed in bulk is suspect.

Geochemistry of speleothem records from southern Illinois: Development of (234U)/(238U) as a proxy for paleoprecipitation

USGS Publications Warehouse

Zhou, Juanzuo; Lundstrom, C.C.; Fouke, B.; Panno, S.; Hackley, K.; Curry, B.

2005-01-01

Natural waters universally show fractionation of uranium series (U-series) parent-daughter pairs, with the disequilibrium between 234U and 238U (234U)/(238U) commonly used as a tracer of groundwater flow. Because speleothems provide a temporal record of geochemical variations in groundwater precipitating calcite, (234U)/(238U) variations in speleothems provide a unique method of investigating water-rock interaction processes over millennium time scales. We present high precision Thermal Ionization Mass Spectrometric (TIMS) U-series analyses of speleothems and drip waters from Fogelpole Cave in southern Illinois. Data from all speleothems from the cave show an inverse correlation between (234U)/(238U) and U concentration, following the pattern observed in groundwaters globally. Within a 65-cm-long stalagmite, concordant 234U-238 U-230Th and 235U-231Pa ages for 5 samples indicate accurate chronology from 78.5 ka to 30 ka. Notably, (234U)/(238U)o which differs from most speleothems by having (234U)/(238U)o <1, positively correlates with speleothem growth rate. We generalize this to the observation that speleothems globally show (234U)/ (238U)o deviating farther from secular equilibrium at lower growth rates and approaching secular equilibrium at higher grow rates. Based on the Fogelpole observations, we suggest that groundwater (234U)/(238U) is controlled by the U oxidation state, the U concentration of the water and the fluid velocity. A transport model whereby U-series nuclides react and exchange with mineral surfaces can reproduce the observed trend between growth rate and (234U)/(238U)o. Based on this result, we suggest that (234U)/(238U)o in speleothems may record changes in hydrologic flux with time and thus could provide a useful proxy for long term records of paleoprecipitation. ?? 2005 Elsevier B.V. All rights reserved.

Apocalypticism in Secular Public Discourse: A Proposed Theory.

ERIC Educational Resources Information Center

Mixon, Harold; Hopkins, Mary Frances

1989-01-01

Examines Biblical apocalyptic theory and secular apocalyptic literature. Proposes a new theory of apocalypticism in secular public discourse derived from those two major theories. Provides examples of apocalypticism in secular public discourse. (MM)

The influence of the great inequality on the secular disturbing function of the planetary system.

NASA Technical Reports Server (NTRS)

Musen, P.

1971-01-01

This paper derives the contribution by the great inequality to the secular disturbing function of the principal planets. Andoyer's expansion of the planetary disturbing function and von Zeipel's method of eliminating the periodic terms is employed; thereby, the corrected secular disturbing function for the planetary system is derived. The conclusion is drawn that the canonicity of the equations for the secular variation of the heliocentric elements can be preserved if there be retained, in the secular disturbing function, terms only of the second and fourth order relative to the eccentricity and inclinations. The Krylov-Bogoliubov method is suggested for eliminating periodic terms, if it is desired to include the secular perturbations of the fifth and higher order in the heliocentric elements. The additional part of the secular disturbing function derived in this paper can be included in existing theories of the secular effects of principal planets.

Evaporation-based Ge/.sup.68 Ga Separation

DOEpatents

Mirzadeh, Saed; Whipple, Richard E.; Grant, Patrick M.; O'Brien, Jr., Harold A.

1981-01-01

Micro concentrations of .sup.68 Ga in secular equilibrium with .sup.68 Ge in strong aqueous HCl solution may readily be separated in ionic form from the .sup.68 Ge for biomedical use by evaporating the solution to dryness and then leaching the .sup.68 Ga from the container walls with dilute aqueous solutions of HCl or NaCl. The chloro-germanide produced during the evaporation may be quantitatively recovered to be used again as a source of .sup.68 Ga. If the solution is distilled to remove any oxidizing agents which may be present as impurities, the separation factor may easily exceed 10.sup.5. The separation is easily completed and the .sup.68 Ga made available in ionic form in 30 minutes or less.

Collapse of magnetized hypermassive neutron stars in general relativity.

PubMed

Duez, Matthew D; Liu, Yuk Tung; Shapiro, Stuart L; Shibata, Masaru; Stephens, Branson C

2006-01-27

Hypermassive neutron stars (HMNSs)--equilibrium configurations supported against collapse by rapid differential rotation--are possible transient remnants of binary neutron-star mergers. Using newly developed codes for magnetohydrodynamic simulations in dynamical spacetimes, we are able to track the evolution of a magnetized HMNS in full general relativity for the first time. We find that secular angular momentum transport due to magnetic braking and the magnetorotational instability results in the collapse of an HMNS to a rotating black hole, accompanied by a gravitational wave burst. The nascent black hole is surrounded by a hot, massive torus undergoing quasistationary accretion and a collimated magnetic field. This scenario suggests that HMNS collapse is a possible candidate for the central engine of short gamma-ray bursts.

Quantitative radiochemical method for determination of major sources of natural radioactivity in ores and minerals

USGS Publications Warehouse

Rosholt, J.N.

1954-01-01

When an ore sample contains radioactivity other than that attributable to the uranium series in equilibrium, a quantitative analysis of the other emitters must be made in order to determine the source of this activity. Thorium-232, radon-222, and lead-210 have been determined by isolation and subsequent activity analysis of some of their short-lived daughter products. The sulfides of bismuth and polonium are precipitated out of solutions of thorium or uranium ores, and the ??-particle activity of polonium-214, polonium-212, and polonium-210 is determined by scintillation-counting techniques. Polonium-214 activity is used to determine radon-222, polonium-212 activity for thorium-232, and polonium-210 for lead-210. The development of these methods of radiochemical analysis will facilitate the rapid determination of some of the major sources of natural radioactivity.

Radiochemical analyses of surface water from U.S. Geological Survey hydrologic bench-mark stations

USGS Publications Warehouse

Janzer, V.J.; Saindon, L.G.

1972-01-01

The U.S. Geological Survey's program for collecting and analyzing surface-water samples for radiochemical constituents at hydrologic bench-mark stations is described. Analytical methods used during the study are described briefly and data obtained from 55 of the network stations in the United States during the period from 1967 to 1971 are given in tabular form.Concentration values are reported for dissolved uranium, radium, gross alpha and gross beta radioactivity. Values are also given for suspended gross alpha radioactivity in terms of natural uranium. Suspended gross beta radioactivity is expressed both as the equilibrium mixture of strontium-90/yttrium-90 and as cesium-137.Other physical parameters reported which describe the samples include the concentrations of dissolved and suspended solids, the water temperature and stream discharge at the time of the sample collection.

Experimental determination of the steady-state charging probabilities and particle size conservation in non-radioactive and radioactive bipolar aerosol chargers in the size range of 5-40 nm

NASA Astrophysics Data System (ADS)

Kallinger, Peter; Szymanski, Wladyslaw W.

2015-04-01

Three bipolar aerosol chargers, an AC-corona (Electrical Ionizer 1090, MSP Corp.), a soft X-ray (Advanced Aerosol Neutralizer 3087, TSI Inc.), and an α-radiation-based 241Am charger (tapcon & analysesysteme), were investigated on their charging performance of airborne nanoparticles. The charging probabilities for negatively and positively charged particles and the particle size conservation were measured in the diameter range of 5-40 nm using sucrose nanoparticles. Chargers were operated under various flow conditions in the range of 0.6-5.0 liters per minute. For particular experimental conditions, some deviations from the chosen theoretical model were found for all chargers. For very small particle sizes, the AC-corona charger showed particle losses at low flow rates and did not reach steady-state charge equilibrium at high flow rates. However, for all chargers, operating conditions were identified where the bipolar charge equilibrium was achieved. Practically, excellent particle size conservation was found for all three chargers.

Direct and precise determination of environmental radionuclides in solid materials using a modified Marinelli beaker and a HPGe detector.

PubMed

Seo, B K; Lee, K Y; Yoon, Y Y; Lee, D W

2001-06-01

A simple but precise detection method was studied for the determination of natural radionuclides using a conventional HPGe detector. A new aluminium beaker instead of a plastic Marinelli beaker was constructed and examined to reach radioactive equilibrium conditions between radon and its daughter elements without the escape of gaseous radon. Using this beaker fifteen natural radionuclides from three natural decay series could be determined by direct gamma-ray measurement and sixteen radionuclides could be determined indirectly after radioactive equilibrium had been reached. Analytical results from ground water were compared with those from conventional alpha spectroscopy and the results agreed well within 12% difference. Nitrogen gas purge was used to replace the surrounding air of the detector to obtain a stable background and reducing the interference of radon daughter nuclides in the atmosphere. The use of nitrogen purging and the aluminium Marinelli beaker results in an approximately tenfold increase of sensitivity and a decrease of the detection limit of 226Ra to about 0.74 Bq kg(-1) in soil samples.

Nonsecular Medical Anthropology.

PubMed

Whitmarsh, Ian; Roberts, Elizabeth F S

2016-01-01

A nonsecular medical anthropology insists on the ways medicine and science have constituted 'the secular' itself through the 'secular self'-how medical knowing has been used to craft the secular political subject. As James Boon noted, too often in social theory, "religion gets safely tucked away-restricted theoretically to 'meaning' rather than power" (1998:245). The authors of the six articles in this special issue 'untuck' religiosity from within the norms and numbers of medicine itself, and examine how 'secular' medicine has relied on religious traditions to produce political secularity. These articles demonstrate that 'secular' medicine relies on religious others whose exclusion bespeaks latent religious commitments of citizenship in the modern political realm of health.

Secular resonances with Ceres and Vesta

NASA Astrophysics Data System (ADS)

Tsirvoulis, Georgios; Novaković, Bojan

2016-12-01

In this work we explore dynamical perturbations induced by the massive asteroids Ceres and Vesta on main-belt asteroids through secular resonances. First we determine the location of the linear secular resonances with Ceres and Vesta in the main belt, using a purely numerical technique. Then we use a set of numerical simulations of fictitious asteroids to investigate the importance of these secular resonances in the orbital evolution of main-belt asteroids. We found, evaluating the magnitude of the perturbations in the proper elements of the test particles, that in some cases the strength of these secular resonances is comparable to that of known non-linear secular resonances with the giant planets. Finally we explore the asteroid families that are crossed by the secular resonances we studied, and identified several cases where the latter seem to play an important role in their post-impact evolution.

On the thermo-chemical origin of the stratified region at the top of the Earth's core

NASA Astrophysics Data System (ADS)

Nakagawa, Takashi

2018-03-01

I developed a combined model of the thermal and chemical evolution of the Earth's core and investigated its influence on a thermochemically stable region beneath the core-mantle boundary (CMB). The chemical effects of the growing stable region are caused by the equilibrium chemical reaction between silicate and the metallic core. The thermal effects can be characterized by the growth of the sub-isentropic shell, which may have a rapid growth rate compared to that of the chemically stable region. When the present-day CMB heat flow was varied, the origin of the stable region changed from chemical to thermochemical to purely thermal because the rapid growth of the sub-isentropic shell can replace the chemically stable region. Physically reasonable values of the present-day CMB heat flow that can maintain the geodynamo action over 4 billion years should be between 8 and 11 TW. To constrain the thickness of the thermochemically stable region beneath the CMB, the chemical diffusivity is important and should be ∼O(10-8) m2/s to obtain a thickness of the thermochemically stable region beneath the CMB consistent with that inferred from geomagnetic secular variations (140 km). However, the strength of the stable region found in this study is too high to be consistent with the constraint on the stability of the stable region inferred from geomagnetic secular variations.

Biomedical silver-109m isotope generator

DOEpatents

Wanek, Philip M.; Steinkruger, Frederick J.; Moody, David C.

1987-01-01

A method, composition of matter, and apparatus for producing substantially pure Ag-109m for use in biomedical imaging techniques. Cd-109, which decays with a half-life of 453 days to Ag-109m is loaded onto an ion exchange column consisting of particulate tin phosphate. After secular equilibrium is reached in about ten minutes, Ag-109m may be selectively eluted from the column by means of a physiologically acceptable aqueous buffered eluent solution of sodium thiosulfate, and either ascorbic acid or dextrose. The breakthrough of toxic Cd-109 is on the order of 1.times.10.sup.-7, which is sufficiently low to permit administration of the Ag-109m-containing eluate, with but a minor pH adjustment, directly to a human patient within a matter of seconds.

Biomedical silver-109m isotope generator

DOEpatents

Wanek, P.M.; Steinkruger, F.J.; Moody, D.C.

1985-03-05

A method, composition of matter, and apparatus for producing substantially pure Ag-109m for use in biomedical imaging techniques. Cd-109, which decays with a half-life of 453 days to Ag-109m, is loaded onto an ion exchange column consisting of particulate tin phosphate. After secular equilibrium is reached in about ten minutes, Ag-109m may be selectively eluted from the column by means of a physiologically acceptable aqueous buffered eluent solution of sodium thiosulfate, and either ascorbic acid or dextrose. The breakthrough of toxic Cd-109 is on the order of 1 x 10-7, which is sufficiently low to permit administration of the Ag-109m-containing eluate, with but a minor pH adjustment, directly to a human patient within a matter of seconds. 1 fig.

An Update on Binary Formation by Rotational Fission

NASA Astrophysics Data System (ADS)

Tohline, Joel E.; Durisen, Richard H.

During the 1980s, numerical simulations showed that dynamic growth of a barlike mode in initially axisymmetric, equilibrium protostars does not lead to prompt binary formation, i. e., fission. Instead, such evolutions usually produce a dynamically stable, spinning barlike configuration. In recent years, this result has been confirmed by numerous groups using a variety of different hydrodynamical tools, and stability analyses have convincingly shown that fission does not occur in such systems because gravitational torques cause nonlinear saturation of the mode amplitude. Other possible routes to fission have been much less well scrutinized because they rely upon a detailed understanding of the structure and stability of initially nonaxisymmetric structures and/or evolutions that are driven by secular, rather than dynamic processes. Efforts are underway to examine these other fission scenarios.

From mantle to ash cloud: quantifying magma generation, ascent, and degassing rates at Kilauea during short-lived explosive episodes using short-lived U-series radionuclide disequilibria

NASA Astrophysics Data System (ADS)

Girard, G.; Reagan, M. K.; Sims, K. W.; Garcia, M. O.; Pietruszka, A. J.; Thornber, C. R.

2012-12-01

We analyzed for 238U-series isotopes lava, scoria and ash samples erupted from Kilauea volcano, Hawai'i between 1982 and 2008, in order to investigate processes and timescales of magma generation in the mantle, magma ascent through the crust, and eruption. Timescales of degassing during steady-state lava flow activity occurring in Kilauea East Rift Zone and short-lived explosive episodes that occurred in both the East Rift Zone (Pu'u 'O'o vent opening in 1983 and episode 54 at Nāpau crater in January 1997) and on the summit (Halema'uma'u crater eruptions in March 2008) are compared and contrasted. All samples were found to have small but variable 230Th and 226Ra activity excesses over 238U and 230Th, respectively, with (230Th/238U) ratios ranging from 1.00 to 1.13 and (226Ra/230Th) ratios ranging from 1.03 to 1.17. These two variable isotopic disequilibria may reflect local heterogeneities in the mantle underneath Kilauea, with sources in relatively primitive mantle with (238U)-(230Th)-(226Ra) in secular equilibrium and in recently (< 8000 years) depleted mantle with (230Th) and (226Ra) deficits over parent nuclides. In this model, both types of mantle melt to generate Kilauea magmas and subsequently mix in variable proportions. Samples from the brief explosive episodes span the entire composition range, suggesting that they were fed by heterogeneous magma batches which did not homogenize during ascent from the mantle. (210Pb/226Ra) ratios range from 0.75 to 1.00. The lack of correlation between (210Pb/226Ra) and (226Ra/230Th) or (230Th/238U), and the rapid return to secular equilibrium of 210Pb (< 100 years) suggest a fractionation process distinct from and subsequent to the Ra-Th-U fractionation inherited from mantle melting. We hypothesize that 210Pb deficits originate from 222Rn degassing during magma ascent, and estimate magma ascent from lower crust to surface to take place in a maximum of ~ 7 years for the lava flow samples. Products from the explosive episodes have ratios from ~ 0.75 to near equilibrium, suggesting that they comprise of a mix of young melts and degassed magmas which were stored in the shallow volcanic edifice for a few decades, in agreement with existing petrologic models.

Relationships between CO 2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

DOE PAGES

Winnick, Matthew J.; Maher, Kate

2018-01-27

Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO 2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO 2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. Here, we test this theoretical scaling relationship against reactive transport simulations of chemical weathering profilesmore » under open-and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO 2(y =kx n)where nis dependent on reaction stoichiometry and kis dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO 2 at low values and approach open-system scaling at high pCO 2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO 2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence of equilibrium solute concentrations on pCO 2 may represent a direct weathering feedback largely independent of climate and modulated by belowground organic carbon respiration.« less

Relationships between CO 2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

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

Winnick, Matthew J.; Maher, Kate

Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO 2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO 2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. Here, we test this theoretical scaling relationship against reactive transport simulations of chemical weathering profilesmore » under open-and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO 2(y =kx n)where nis dependent on reaction stoichiometry and kis dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO 2 at low values and approach open-system scaling at high pCO 2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO 2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence of equilibrium solute concentrations on pCO 2 may represent a direct weathering feedback largely independent of climate and modulated by belowground organic carbon respiration.« less

Relationships between CO2, thermodynamic limits on silicate weathering, and the strength of the silicate weathering feedback

NASA Astrophysics Data System (ADS)

Winnick, Matthew J.; Maher, Kate

2018-03-01

Recent studies have suggested that thermodynamic limitations on chemical weathering rates exert a first-order control on riverine solute fluxes and by extension, global chemical weathering rates. As such, these limitations may play a prominent role in the regulation of carbon dioxide levels (pCO2) over geologic timescales by constraining the maximum global weathering flux. In this study, we develop a theoretical scaling relationship between equilibrium solute concentrations and pCO2 based on equilibrium constants and reaction stoichiometry relating primary mineral dissolution and secondary mineral precipitation. We test this theoretical scaling relationship against reactive transport simulations of chemical weathering profiles under open- and closed-system conditions, representing partially and fully water-saturated regolith, respectively. Under open-system conditions, equilibrium bicarbonate concentrations vary as a power-law function of pCO2 (y = kxn) where n is dependent on reaction stoichiometry and k is dependent on both reaction stoichiometry and the equilibrium constant. Under closed-system conditions, bicarbonate concentrations vary linearly with pCO2 at low values and approach open-system scaling at high pCO2. To describe the potential role of thermodynamic limitations in the global silicate weathering feedback, we develop a new mathematical framework to assess weathering feedback strength in terms of both (1) steady-state atmospheric pCO2 concentrations, and (2) susceptibility to secular changes in degassing rates and transient carbon cycle perturbations, which we term 1st and 2nd order feedback strength, respectively. Finally, we discuss the implications of these results for the effects of vascular land plant evolution on feedback strength, the potential role of vegetation in controlling modern solute fluxes, and the application of these frameworks to a more complete functional description of the silicate weathering feedback. Most notably, the dependence of equilibrium solute concentrations on pCO2 may represent a direct weathering feedback largely independent of climate and modulated by belowground organic carbon respiration.

Species removal from aqueous radioactive waste by deep-bed filtration.

PubMed

Dobre, Tănase; Zicman, Laura Ruxandra; Pârvulescu, Oana Cristina; Neacşu, Elena; Ciobanu, Cătălin; Drăgolici, Felicia Nicoleta

2018-05-26

Performances of aqueous suspension treatment by deep-bed sand filtration were experimentally studied and simulated. A semiempirical deterministic model and a stochastic model were used to predict the removal of clay particles (20 μm) from diluted suspensions. Model parameters, which were fitted based on experimental data, were linked by multiple linear correlations to the process factors, i.e., sand grain size (0.5 and 0.8 mm), bed depth (0.2 and 0.4 m), clay concentration in the feed suspension (1 and 2 kg p /m 3 ), suspension superficial velocity (0.015 and 0.020 m/s), and operating temperature (25 and 45 °C). These relationships were used to predict the bed radioactivity determined by the deposition of radioactive suspended particles (>50 nm) from low and medium level aqueous radioactive waste. A deterministic model based on mass balance, kinetic, and interface equilibrium equations was developed to predict the multicomponent sorption of 60 Co, 137 Cs, 241 Am, and 3 H radionuclides (0.1-0.3 nm). A removal of 98.7% of radioactive particles was attained by filtering a radioactive wastewater volume of 10 m 3 (0.5 mm sand grain size, 0.3 m bed depth, 0.223 kg p /m 3 suspended solid concentration in the feed suspension, 0.003 m/s suspension superficial velocity, and 25 °C operating temperature). Predicted results revealed that the bed radioactivity determined by the sorption of radionuclides (0.01 kBq/kg b ) was significantly lower than the bed radioactivities caused by the deposition of radioactive particles (0.5-1.8 kBq/kg b ). Copyright © 2018 Elsevier Ltd. All rights reserved.

[Distribution of 137Cs, 90Sr and their chemical analogues in the components of an above-ground part of a pine in a quasi-equilibrium condition].

PubMed

Mamikhin, S V; Manakhov, D V; Shcheglov, A I

2014-01-01

The additional study of the distribution of radioactive isotopes of caesium and strontium and their chemical analogues in the above-ground components of pine in the remote from the accident period was carried out. The results of the research confirmed the existence of analogy in the distribution of these elements on the components of this type of wood vegetation in the quasi-equilibrium (relatively radionuclides) condition. Also shown is the selective possibility of using the data on the ash content of the components of forest stands of pine and oak as an information analogue.

Testing the Limits to Accurate Comminution Dates: A Progress Report

NASA Astrophysics Data System (ADS)

Piccione, G.; Blackburn, T.; Edwards, G. H.

2017-12-01

The ability to resolve the timing of fine particle production holds potential for contributing to several Earth Science sub-disciplines including glaciology, eolian and fluvial geomorphology, soil production, and fault dynamics. A relatively new geochronologic tool, U-series comminution dating, has shown potential to directly date the timing of particle comminution. This system's sensitivity to particle size arises from a physical disequilibrium in the 238U decay chain generated by the ejected loss of intermediate daughter products (e.g. 234U). It is the goal of this ongoing study to develop and test analytical procedures to improve the accuracy of comminution dating. In the geologic settings explored by previous studies, comminution dates integrate both the time of particle transport and time since deposition. To better test the accuracy of comminution dates, our study focuses on settings where silt has experienced little to no transport time, specifically, glacial moraines in the Eastern Sierras and Rock Avalanches in the San Gabriel Mountains, both locations with existing independent geochronologic constraints. Previous studies demonstrate the dependency of U-series comminution date on grain size and shape. Here we show that mineralogy of samples also plays a role, possibly controlled by the uranium content and crystal bond strength. To separate samples by size and mineralogy, we use dry sonic-sieving, density and magnetic separation. Non-detrital materials deposited on the rim of comminuted grains have an isotopic composition that is unrelated to the isotopic evolution since comminution and therefore must be removed through a multi-step leaching procedure. Leaching is complicated by the fact that areas within the comminuted crystal that have experienced physical fractionation are contained within damaged zones and are prone to being leached themselves, which removes areas of interest from the crystal. We present progress made on a sample processing method developed to alleviate complications that affect comminution age measurements. Initial 234U/238U measurements for untreated silt from an 800ka Sierran glacial till are up to 6% above secular equilibrium, while samples processed with this method have measured ratios as low as 3% below secular equilibrium.

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

Takahashi, Sanemichi Z.; Inutsuka, Shu-ichiro, E-mail: sanemichi@astr.tohoku.ac.jp, E-mail: inutsuka@nagoya-u.jp

Recent ALMA observation has revealed multiple ring structures formed in a protoplanetary disk around HL Tau. Prior to the ALMA observation of HL Tau, theoretical analysis of secular gravitational instability (GI) described a possible formation of multiple ring structures with separations of 13 au around a radius of 100 au in protoplanetary disks under certain conditions. In this article, we reanalyze the viability of secular GI by adopting the physical values inferred from the observations. We derive the radial distributions of the most unstable wavelength and the growth timescale of secular GI and verify that secular GI can form themore » ring structures observed in HL Tau. When a turbulent viscosity coefficient α remains small in the inner region of the disk, secular GI grows in the whole disk. Thus, the formation of planetary mass objects should occur first in the inner region as a result of gravitational fragmentation after the nonlinear growth of secular GI. In this case, the resulting objects are expected to create gaps at r  ∼ 10 au and ∼30 au. As a result, all ring structures in HL Tau can be created by secular GI. If this scenario is realized in HL Tau, the outer region corresponds to the earlier growth phase of the most unstable mode of secular GI, and the inner region corresponds to the outcome of the nonlinear growth of secular GI. Therefore, this interpretation suggests that we are possibly witnessing both the beginning and the end of planet formation in HL Tau.« less

Secular Evolution of Galaxies

NASA Astrophysics Data System (ADS)

Falcón-Barroso, Jesús; Knapen, Johan H.

2013-10-01

Preface; 1. Secular evolution in disk galaxies John Kormendy; 2. Galaxy morphology Ronald J. Buta; 3. Dynamics of secular evolution James Binney; 4. Bars and secular evolution in disk galaxies: theoretical input E. Athanassoula; 5. Stellar populations Reynier F. Peletier; 6. Star formation rate indicators Daniela Calzetti; 7. The evolving interstellar medium Jacqueline van Gorkom; 8. Evolution of star formation and gas Nick Z. Scoville; 9. Cosmological evolution of galaxies Isaac Shlosman.

Modeling tritium transport through a deep unsaturated zone in an arid environment

USGS Publications Warehouse

Mayers, C.J.; Andraski, Brian J.; Cooper, C.A.; Wheatcraft, S.W.; Stonestrom, David A.; Michel, R.L.

2005-01-01

Understanding transport of tritium (3H) in unsaturated zones is critical to evaluating options for waste isolation. Tritium typically is a large component of low-level radioactive waste (LLRW). Studies at the U.S. Geological Survey's Amargosa Desert Research Site (ADRS) in Nevada investigate 3H transport from a closed LLRW facility. Two boreholes are 100 and 160 m from the nearest waste trench and extend to the water table at 110 m. Soil-water vapor samples from the deep boreholes show elevated levels of 3H at all depths. The objectives of this study were to (i) test source thermal and gas-advection mechanisms driving 3H transport and (ii) evaluate model sensitivity to these mechanisms and to selected physical and hydraulic properties including porosity, tortuosity, and anisotropy. A two-dimensional numerical model incorporated a non-isothermal, heterogeneous domain of the unsaturated zone and instantaneous isotopic equilibrium. The TOUGH2 code was used; however, it required modification to account for temperature dependence of both the Henry's law equilibrium constant and isotopic fractionation with respect to tritiated water. Increases in source temperature, pressure, and porosity enhanced 3H migration, but failed to match measured 3H distributions. All anisotropic simulations with a source pressure component resembled, in shape, the upper portion of the 3H distribution of the nearest borehole. Isotopic equilibrium limited migration of 3H, while effects of radioactive decay were negligible. A 500 Pa pressure increase above ambient pressure in conjunction with a high degree of anisotropy (1:100) was necessary for simulated 3H transport to reach the nearest borehole.

Secular Orbit Evolution in Systems with a Strong External Perturber—A Simple and Accurate Model

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

Andrade-Ines, Eduardo; Eggl, Siegfried, E-mail: eandrade.ines@gmail.com, E-mail: siegfried.eggl@jpl.nasa.gov

We present a semi-analytical correction to the seminal solution for the secular motion of a planet’s orbit under gravitational influence of an external perturber derived by Heppenheimer. A comparison between analytical predictions and numerical simulations allows us to determine corrective factors for the secular frequency and forced eccentricity in the coplanar restricted three-body problem. The correction is given in the form of a polynomial function of the system’s parameters that can be applied to first-order forced eccentricity and secular frequency estimates. The resulting secular equations are simple, straight forward to use, and improve the fidelity of Heppenheimers solution well beyond higher-ordermore » models. The quality and convergence of the corrected secular equations are tested for a wide range of parameters and limits of its applicability are given.« less

The 1995 revision of the joint US/UK geomagnetic field models - I. Secular variation

USGS Publications Warehouse

Macmillan, S.; Barraclough, D.R.; Quinn, J.M.; Coleman, R.J.

1997-01-01

We present the methods used to derive mathematical models of global secular variation of the main geomagnetic field for the period 1985 to 2000. These secular-variation models are used in the construction of the candidate US/UK models for the Definitive Geomagnetic Reference Field at 1990, the International Geomagnetic Reference Field for 1995 to 2000, and the World Magnetic Model for 1995 to 2000 (see paper II, Quinn et al., 1997). The main sources of data for the secular-variation models are geomagnetic observatories and repeat stations. Over the areas devoid of these data secular-variation information is extracted from aeromagnetic and satellite data. We describe how secular variation is predicted up to the year 2000 at the observatories and repeat stations, how the aeromagnetic and satellite data are used, and how all the data are combined to produce the required models.

Analytic Approximation of Carbon Condensation Issues in Type ii Supernovae

NASA Astrophysics Data System (ADS)

Clayton, Donald D.

2013-01-01

I present analytic approximations for some issues related to condensation of graphite, TiC, and silicon carbide in oxygen-rich cores of supernovae of Type II. Increased understanding, which mathematical analysis can support, renders researchers more receptive to condensation in O-rich supernova gases. Taking SN 1987A as typical, my first analysis shows why the abundance of CO molecules reaches an early maximum in which free carbon remains more abundant than CO. This analysis clarifies why O-rich gas cannot oxidize C if 56Co radioactivity is as strong as in SN 1987A. My next analysis shows that the CO abundance could be regarded as being in chemical equilibrium if the CO molecule is given an effective binding energy rather than its laboratory dissociation energy. The effective binding energy makes the thermal dissociation rate of CO equal to its radioactive dissociation rate. This preserves possible relevance for the concept of chemical equilibrium. My next analysis shows that the observed abundances of CO and SiO molecules in SN 1987A rule out frequent suggestions that equilibrium condensation of SUNOCONs has occurred following atomic mixing of the He-burning shell with more central zones in such a way as to reproduce roughly the observed spectrum of isotopes in SUNOCONs while preserving C/O > 1. He atoms admixed along with the excess carbon would destroy CO and SiO molecules, leaving their observed abundances unexplained. The final analysis argues that a chemical quasiequilibrium among grains (but not gas) may exist approximately during condensation, so that its computational use is partially justified as a guide to which mineral phases would be stable against reactions with gas. I illustrate this point with quasiequilibrium calculations by Ebel & Grossman that have shown that graphite is stable even when O/C >1 if prominent molecules are justifiably excluded from the calculation of chemical equilibrium.

Mechanism of uptake of nitrosoureas by L5178Y lymphoblasts in vitro.

PubMed

Begleiter, A; Lam, H P; Goldenberg, G J

1977-04-01

The mechanism of uptake of nitrosoureas by L5178Y cells in vitro was investigated. A time course of the uptake of radioactivity on incubation of L5178Y lymphoblast with [14C]-1,3-bis(2-chloroethyl)-1-nitrosourea was linear for 30 min and then entered a plateau phase; it was markedly temperature dependent. A similar time course for cells incubated with [14C]ethylene-labeled 1-(2-chlorethyl)-3-cyclohexyl-1-nitrosourea reached equilibrium rapidly, was temperature independent, and resulted in a relatively low level of uptake of radioactivity. However, cells treated with 3-[cyclohexyl-14C]-1-(2-chlorethyl)-1-nitrosourea had a time course that was linear for 30 min, resulted in much higher levels of uptake of radioactivity, and was strongly temperature dependent. These findings, at least for 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea, suggest that some drug decomposition precedes uptake. The percentage of radioactivity found in the cell sap fraction was at least 85% of total cell activity when cells were incubated with any of the three 14C-labeled nitrosoureas. Furthermore, thin-layer chromatography of the cell sap fraction revealed the presence of free intact drug. These findings indicate that intracellular uptake of intact nitrosoureas occurred. A time course of uptake of intact 1,3-bis(2-chloroethyl)-1-nitrosourea reached equilibrium rapidly with cell/medium distribution ratios of 0.2 to 0.6 and was temperature independent. The addition of excess unlabeled 1,3-bis(2-chlorethyl)-1-nitrosourea or 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea had no effect on uptake of [14C]-1,3-bis(2-chloroethyl)-1-nitrosourea, These findings suggest that uptake of intact 1,3-bis(2-chloroethyl)-1-nitrosourea was by passive diffusion. A time course of the uptake of intact 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea with either [14C]ethylene- or ring-labeled drug rapidly reached equilibrium, was temperature independent, and attained a cell/medium ratio greater than unity. Uptake of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea was sodium independent and was unaffected by the metabolic inhibitors (sodium fluoride, sodium cyanide, or 2,4-dinitrophenol) or by urea, a potential physiological competitor. Furthermore, addition of unlabeled 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea or 1,3-bis(2-chlorethyl)-1-nitrosourea had no effect on uptake of labeled 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea. These findings suggest that uptake of 1-(2-chloroethyl)-3-cyclohexyl-1-nitrosourea also occurs by passive diffusion.

Secular variations in zonal harmonics of Earth's geopotential and their implications for mantle viscosity and Antarctic melting history due to the last deglaciation

NASA Astrophysics Data System (ADS)

Nakada, Masao; Okuno, Jun'ichi

2017-06-01

Secular variations in zonal harmonics of Earth's geopotential based on the satellite laser ranging observations, {\\dot{J}_n}, contain important information about the Earth's deformation due to the glacial isostatic adjustment (GIA) and recent melting of glaciers and the Greenland and Antarctic ice sheets. Here, we examine the GIA-induced {\\dot{J}_n}, \\dot{J}_n^{GIA} (2 ≤ n ≤ 6), derived from the available geopotential zonal secular rate and recent melting taken from the IPCC 2013 Report (AR5) to explore the possibility of additional information on the depth-dependent lower-mantle viscosity and GIA ice model inferred from the analyses of the \\dot{J}_2^{GIA} and relative sea level changes. The sensitivities of the \\dot{J}_n^{GIA} to lower-mantle viscosity and GIA ice model with a global averaged eustatic sea level (ESL) of ∼130 m indicate that the secular rates for n = 3 and 4 are mainly caused by the viscous response of the lower mantle to the melting of the Antarctic ice sheet regardless of GIA ice models adopted in this study. Also, the analyses of the \\dot{J}_n^{GIA} based on the available geopotential zonal secular rates indicate that permissible lower-mantle viscosity structure satisfying even zonal secular rates of n = 2, 4 and 6 is obtained for the GIA ice model with an Antarctic ESL component of ∼20 or ∼30 m, but there is no viscosity solution satisfying \\dot{J}_3^{GIA} and \\dot{J}_5^{GIA} values. Moreover, the inference model for the lower-mantle viscosity and GIA ice model from each odd zonal secular rate is distinctly different from that satisfying GIA-induced even zonal secular rate. The discrepancy between the inference models for the even and odd zonal secular rates may partly be attributed to uncertainties of the geopotential zonal secular rates for n > 2 and particularly those for odd zonal secular rates due to weakness in the orbital geometry. If this problem is overcome at least for the secular rates of n < 5, then the analyses of the \\dot{J}_n^{GIA} would make it possible to put more convincing constraints on the lower-mantle viscosity structure and GIA ice model, particularly for the controversial Antarctic melting history in GIA community.

Triaxial instabilities in rapidly rotating neutron stars

NASA Astrophysics Data System (ADS)

Basak, Arkadip

2018-06-01

Viscosity driven bar mode secular instabilities of rapidly rotating neutron stars are studied using LORENE/Nrotstar code. These instabilities set a more rigorous limit to the rotation frequency of a neutron star than the Kepler frequency/mass-shedding limit. The procedure employed in the code comprises of perturbing an axisymmetric and stationary configuration of a neutron star and studying its evolution by constructing a series of triaxial quasi-equilibrium configurations. Symmetry breaking point was found out for Polytropic as well as 10 realistic equations of states (EOS) from the CompOSE data base. The concept of piecewise polytropic EOSs has been used to comprehend the rotational instability of Realistic EOSs and validated with 19 different Realistic EOSs from CompOSE. The possibility of detecting quasi-periodic gravitational waves from viscosity driven instability with ground-based LIGO/VIRGO interferometers is also discussed very briefly.

Plate motion and the secular shift of the mean pole

NASA Technical Reports Server (NTRS)

Liu, H.; Carpenter, L.; Agreen, R. W.

1973-01-01

The global plate motion indicates that changes in the products of inertia of the earth due to tectonic plate movement may provide a secular shift of the mean pole. A mathematical procedure for calculating this shift based on the plate theory is presented. Explicit expressions were obtained for the dependence of the secular polar shift on the dimensions and locations of the plate boundaries. Numerical results show that the secular motion of the mean pole is 0.0002 sec/year in the direction of 67 W. Hence, it is deduced that the influence of the plate motion on the secular polar shift may account for 10% of the observed value.

Double differential light charged particle emission cross sections for some structural fusion materials

NASA Astrophysics Data System (ADS)

Sarpün, Ismail Hakki; n, Abdullah Aydı; Tel, Eyyup

2017-09-01

In fusion reactors, neutron induced radioactivity strongly depends on the irradiated material. So, a proper selection of structural materials will have been limited the radioactive inventory in a fusion reactor. First-wall and blanket components have high radioactivity concentration due to being the most flux-exposed structures. The main objective of fusion structural material research is the development and selection of materials for reactor components with good thermo-mechanical and physical properties, coupled with low-activation characteristics. Double differential light charged particle emission cross section, which is a fundamental data to determine nuclear heating and material damages in structural fusion material research, for some elements target nuclei have been calculated by the TALYS 1.8 nuclear reaction code at 14-15 MeV neutron incident energy and compared with available experimental data in EXFOR library. Direct, compound and pre-equilibrium reaction contribution have been theoretically calculated and dominant contribution have been determined for each emission of proton, deuteron and alpha particle.

The end of the iron-core age.

NASA Technical Reports Server (NTRS)

Lyttleton, R. A.

1973-01-01

The terrestrial planets aggregated essentially from small particles, to begin as solid cool bodies with the same general compositions, and there is no possibility of an iron-core developing within any of them at any stage. Their differing internal and surface properties receive ready explanation from their different masses which determine whether the pressures within are sufficient to bring about phase-changes. The claim that the terrestrial core can be identified by means of shock-wave data as nickel-iron is based on theoretical misconception, whereas the actual seismic data establish an uncompressed-density value much lower than any such mixture could have. The onset of the Ramsey phase-change in the earth takes the form of a rapid initial collapse to produce a large core in metallic state which thereafter continues to grow secularly as a result of radioactive heating and leads to reduction of surface-area at long last adequate to account for folded and thrusted mountain-building.

Field analyses of (238)U and (226)Ra in two uranium mill tailings piles from Niger using portable HPGe detector.

PubMed

Déjeant, Adrien; Bourva, Ludovic; Sia, Radia; Galoisy, Laurence; Calas, Georges; Phrommavanh, Vannapha; Descostes, Michael

2014-11-01

The radioactivities of (238)U and (226)Ra in mill tailings from the U mines of COMINAK and SOMAÏR in Niger were measured and quantified using a portable High-Purity Germanium (HPGe) detector. The (238)U and (226)Ra activities were measured under field conditions on drilling cores with 600s measurements and without any sample preparation. Field results were compared with those obtained by Inductive Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and emanometry techniques. This comparison indicates that gamma-ray absorption by such geological samples does not cause significant deviations. This work shows the feasibility of using portable HPGe detector in the field as a preliminary method to observe variations of radionuclides concentration with the aim of identifying samples of interest. The HPGe is particularly useful for samples with strong secular disequilibrium such as mill tailings. Copyright © 2014 Elsevier Ltd. All rights reserved.

Growth status of indigenous school children 6-14 years in the Tarahumara Sierra, Northern Mexico, in 1990 and 2007.

PubMed

Peña Reyes, Maria Eugenia; Cárdenas Barahona, Eyra E; Lamadrid, Paola Stefani; Del Olmo Calzada, Margarita; Malina, Robert M

2009-01-01

The study evaluated the growth status and secular change in body size of indigenous Tarahumara children in northern Mexico. Heights and weights of Tarahumara children 6-14 years were measured in 1990 (n = 601) and 2007 (n = 583); the BMI was calculated. International criteria defined weight status while United States reference data defined stunting. Estimated secular gains in height from 1990 to 2007 were greatest in 6-7 year-old boys and declined with age to a small, non-significant secular decline in boys 12-14 years. Among girls secular gains in height were similar at 6-7 and 8-9 years, largest at 10-11 years and small and non-significant at 12-14 years. Secular gains in weight were similar among 6-7 and 8-9 year-old boys and girls, were greater in girls than in boys at 10-11 years and showed a small, non-significant secular decline in boys and girls 12-14 years. Secular change in the BMI paralleled those for weight. The prevalence of stunting declined from 1990 to 2007 in both sexes and all age groups except 12-14 year youth. Overweight was more prevalent in girls than boys in both years and increased from 4% to 7% in boys and 9% to 13% in girls. Obesity was not common among boys and girls in each age group and in both years. Stunting and overweight/obesity were not related in either 1990 or 2007. Positive secular changes in growth status have occurred in Tarahumara children 6-11 years in contrast to negligible changes among children 12-14 years. The results suggest recent improvements in health and nutrition sufficient to support a positive secular trend in younger children.

Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems.

PubMed

Lithwick, Yoram; Wu, Yanqin

2014-09-02

In the inner solar system, the planets' orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations.

Secular chaos and its application to Mercury, hot Jupiters, and the organization of planetary systems

PubMed Central

Lithwick, Yoram; Wu, Yanqin

2014-01-01

In the inner solar system, the planets’ orbits evolve chaotically, driven primarily by secular chaos. Mercury has a particularly chaotic orbit and is in danger of being lost within a few billion years. Just as secular chaos is reorganizing the solar system today, so it has likely helped organize it in the past. We suggest that extrasolar planetary systems are also organized to a large extent by secular chaos. A hot Jupiter could be the end state of a secularly chaotic planetary system reminiscent of the solar system. However, in the case of the hot Jupiter, the innermost planet was Jupiter (rather than Mercury) sized, and its chaotic evolution was terminated when it was tidally captured by its star. In this contribution, we review our recent work elucidating the physics of secular chaos and applying it to Mercury and to hot Jupiters. We also present results comparing the inclinations of hot Jupiters thus produced with observations. PMID:24367108

On the icy edge at Louth and Korolev craters

NASA Astrophysics Data System (ADS)

Bapst, Jonathan; Byrne, Shane; Brown, Adrian J.

2018-07-01

The modern climate of Mars has been well characterized from over a decade of orbiting spacecraft, in situ measurements via landers/rovers, and theoretical advances in climate modeling. Nonetheless, important questions remain unanswered, including the present-day mass balance of the north polar residual cap and its icy outliers. Exposed water-ice mounds are found in craters, and extend as far equatorward as 70.2°N. Due to their southerly location, these ice mounds are likely more sensitive to ongoing changes in climate. We analyze high-resolution images of the Louth crater ice mound, and employ a coupled 1-D thermal and atmospheric model to estimate annual mass balance of both Louth and Korolev water ice. We incorporate the effects of shallowly-sloping surfaces and seasonally-dependent water ice albedo. No clear trend in the advance or retreat of Louth crater water ice is observed in over 4 Mars years of repeat, high-resolution images. Secular changes are either sufficiently small as to not be detected, or the ice is in equilibrium. Modeled mass balance ranges from -6 to +2 mm of water ice per Mars year at both sites, with nominal cases being in near-equilibrium (<0.5 mm of ice loss per Mars year).

Modeling the secular evolution of migrating planet pairs

NASA Astrophysics Data System (ADS)

Michtchenko, T. A.; Rodríguez, A.

2011-10-01

The secular regime of motion of multi-planetary systems is universal; in contrast with the 'accidental' resonant motion, characteristic only for specific configurations of the planets, secular motion is present everywhere in phase space, even inside the resonant region. The secular behavior of a pair of planets evolving under dissipative forces is the principal subject of this study, particularly, the case when the dissipative forces affect the planetary semi-major axes and the planets move inward/outward the central star, the process known as planet migration. Based on the fundamental concepts of conservative and dissipative dynamics of the three-body problem, we develop a qualitative model of the secular evolution of the migrating planetary pair. Our approach is based on analysis of the energy and the orbital angular momentum exchange between the two-planet system and an external medium; thus no specific kind of dissipative forces is invoked. We show that, under assumption that dissipation is weak and slow, the evolutionary routes of the migrating planets are traced by the Mode I and Mode II stationary solutions of the conservative secular problem. The ultimate convergence and the evolution of the system along one of these secular modes of motion is determined uniquely by the condition that the dissipation rate is sufficiently smaller than the proper secular frequency of the system. We show that it is possible to reassemble the starting configurations and migration history of the systems on the basis of their final states and consequently to constrain the parameters of the physical processes involved.

Modification of a method-of-characteristics solute-transport model to incorporate decay and equilibrium-controlled sorption or ion exchange

USGS Publications Warehouse

Goode, D.J.; Konikow, Leonard F.

1989-01-01

The U.S. Geological Survey computer model of two-dimensional solute transport and dispersion in ground water (Konikow and Bredehoeft, 1978) has been modified to incorporate the following types of chemical reactions: (1) first-order irreversible rate-reaction, such as radioactive decay; (2) reversible equilibrium-controlled sorption with linear, Freundlich, or Langmuir isotherms; and (3) reversible equilibrium-controlled ion exchange for monovalent or divalent ions. Numerical procedures are developed to incorporate these processes in the general solution scheme that uses method-of- characteristics with particle tracking for advection and finite-difference methods for dispersion. The first type of reaction is accounted for by an exponential decay term applied directly to the particle concentration. The second and third types of reactions are incorporated through a retardation factor, which is a function of concentration for nonlinear cases. The model is evaluated and verified by comparison with analytical solutions for linear sorption and decay, and by comparison with other numerical solutions for nonlinear sorption and ion exchange.

Secular spring rainfall variability at local scale over Ethiopia: trend and associated dynamics

NASA Astrophysics Data System (ADS)

Tsidu, Gizaw Mengistu

2017-10-01

Spring rainfall secular variability is studied using observations, reanalysis, and model simulations. The joint coherent spatio-temporal secular variability of gridded monthly gauge rainfall over Ethiopia, ERA-Interim atmospheric variables and sea surface temperature (SST) from Hadley Centre Sea Ice and SST (HadISST) data set is extracted using multi-taper method singular value decomposition (MTM-SVD). The contemporaneous associations are further examined using partial Granger causality to determine presence of causal linkage between any of the climate variables. This analysis reveals that only the northwestern Indian Ocean secular SST anomaly has direct causal links with spring rainfall over Ethiopia and mean sea level pressure (MSLP) over Africa inspite of the strong secular covariance of spring rainfall, SST in parts of subtropical Pacific, Atlantic, Indian Ocean and MSLP. High secular rainfall variance and statistically significant linear trend show consistently that there is a massive decline in spring rain over southern Ethiopia. This happened concurrently with significant buildup of MSLP over East Africa, northeastern Africa including parts of the Arabian Peninsula, some parts of central Africa and SST warming over all ocean basins with the exception of the ENSO regions. The east-west pressure gradient in response to the Indian Ocean warming led to secular southeasterly winds over the Arabian Sea, easterly over central Africa and equatorial Atlantic. These flows weakened climatological northeasterly flow over the Arabian Sea and southwesterly flow over equatorial Atlantic and Congo basins which supply moisture into the eastern Africa regions in spring. The secular divergent flow at low level is concurrent with upper level convergence due to the easterly secular anomalous flow. The mechanisms through which the northwestern Indian Ocean secular SST anomaly modulates rainfall are further explored in the context of East Africa using a simplified atmospheric general circulation model (AGCM) coupled to mixed-layer oceanic model. The rainfall anomaly (with respect to control simulation), forced by the northwestern Indian Ocean secular SST anomaly and averaged over the 30-year period, exhibits prevalence of dry conditions over East and equatorial Africa in agreement with observation. The atmospheric response to secular SST warming anomaly led to divergent flow at low levels and subsidence at the upper troposphere over regions north of 5° S on the continent and vice versa over the Indian Ocean. This surface difluence over East Africa, in addition to its role in suppressing convective activity, deprives the region of moisture supply from the Indian Ocean as well as the Atlantic and Congo basins.

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

Hassan, N.M.; Ghosh, T.K.; Hines, A.L.

Equilibrium adsorption isotherms are reported for radon and water vapor on two commercial activated carbons: coconut shell Type PCB and hardwood Type BD. The isotherms of the water vapor were measured gravimetrically at 298 K. The isotherms of radon from dry nitrogen were obtained at 293, 298, and 308 K while the data for the mixture of radon and water vapor were measured at 298 K. The concentrations of radon in the gas and solid phases were measured simultaneously, once the adsorption equilibrium and the radioactive equilibrium between the radon and its daughter products were established. The shape of themore » isotherms was of Type III for the radon and Type V for the water vapor, according to Brunauer`s classification. The adsorption mechanism was similar for both the radon and the water vapor, being physical adsorption on the macropore surface area in the low pressure region and micropore filling near saturation pressure. The uptake capacity of radon decreased both with increasing temperature and relative humidity. The heat of adsorption data indicated that the PCB- and the BD-activated carbons provided a heterogeneous surface for radon adsorption. The equilibrium data for radon were correlated with a modified Freundlich equation.« less

Committed Seventh-Day Adventist Students at Secular Institutions of Higher Education

ERIC Educational Resources Information Center

Anthony, LaShonda R.

2013-01-01

The experiences of Seventh-day Adventist students at secular universities was examined. Seven women and two men attending universities in Michigan and New York were interviewed. The researcher employed a heuristically guided phenomenological method to get rich descriptions of the participants' experiences in the secular university setting.…

Secular and Koranic Literacies in South Asia: From Colonisation to Contemporary Practice

ERIC Educational Resources Information Center

Maddox, Bryan

2007-01-01

This paper explores the distinction between "secular" and "Koranic" schooling and literacy in South Asia. It begins by tracing an archaeology of the distinction between secular "literacy" and religious "illiteracy". It locates the emergence of the distinction in the colonial census of the 19th century, in…

Re-Imagining a Christian University in a Secular Age

ERIC Educational Resources Information Center

Warner, Rob

2013-01-01

The contours of a secular age, as delineated by classical and contemporary sociologists of religion, have tended to result in secularising trajectories for church-founded institutions of Higher Education, some of which have migrated towards secular normativity. This article explores these trends and then proposes five characteristics of an…

Rethinking Institutional Secularization as an (Im)possible "Policy"

ERIC Educational Resources Information Center

Gomez Caride, Ezequiel

2015-01-01

The paper analyzes through a genealogical discourse analysis how religion as a cultural practice escapes into the borders of state institutions. While most studies about secularization focus on institutional aspects, such approaches tend to link state secularist policies with cultural secularization. This essay argues that state promotion of…

The Jesuit Imaginary: Higher Education in a Secular Age

ERIC Educational Resources Information Center

Hendrickson, Daniel Scott

2012-01-01

The philosopher Charles Taylor argues in "A Secular Age" (2007) that people who live in secular cultures are losing the capacity to experience genuine "fullness." Described by Taylor as a philosophical-anthropological conception of human flourishing that corresponds with existential senses of meaning and purpose, fullness is…

Internalization and degradation of human chorionic gonadotropin in ovine luteal cells: Kinetic studies

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

Ahmed, C.E.; Sawyer, H.R.; Niswender, G.D.

1981-11-01

Ovine luteal cells grown in suspensions and/or monolayer culture were used to study the rates of internalization and degradation of (/sup 125/I)hCG. At specified times after a 5- to 7-min exposure to (/sup 125/I)hCG, cells were treated with acidic buffer (pH 3.9) to elute membrane-bound hormone, which left the internalized radioactivity associated with the cell pellet. Radioactivity released into the medium during the incubation periods was subjected to 20% trichloroacetic acid and/or thin layer chromatography to monitor the extent of degradation of the radioactive hormone. Secretion of progesterone into the medium and exclusion of trypan blue were used to monitormore » the viability of the cells in each experiment. Radioactivity was lost from the plasma membrane with a tsub1/2 of 9.6 h, with approximately 85% of the radioactivity being lost within 24 h. Cell-associated radioactivity increased linearly with time to a plateau at 4 h, remained stable until 12 h, and then decreased between 12-24 h. The plateau between 4-12 h reflected an equilibrium between the (/sup 125/I)hCG which was internalized and degraded and the (/sup 125/I)hCG which was released into the medium. The degraded (/sup 125/I)hCG increased essentially linearly up to 24 h. These data suggest that the majority of (/sup 125/I)hCG bound to receptors in luteal cells is internalized and degraded. Less than 20% of the radioactivity bound initially to cells dissociated into the incubation medium and was trichloroacetic acid precipitable within 24 h. The internalization and degradation of (/sup 125/I)hCG was temperature dependent, with essentially no hCG internalized and/or degraded at 4C.« less

A study of alternative schemes for extrapolation of secular variation at observatories

USGS Publications Warehouse

Alldredge, L.R.

1976-01-01

The geomagnetic secular variation is not well known. This limits the useful life of geomagnetic models. The secular variation is usually assumed to be linear with time. It is found that attenative schemes that employ quasiperiodic variations from internal and external sources can improve the extrapolation of secular variation at high-quality observatories. Although the schemes discussed are not yet fully applicable in worldwide model making, they do suggest some basic ideas that may be developed into useful tools in future model work. ?? 1976.

Loners, Groupies, and Long-term Eccentricity (and Inclination) Behavior: Insights from Secular Theory

NASA Astrophysics Data System (ADS)

Van Laerhoven, Christa L.

2015-05-01

Considering the secular dynamics of multi-planet systems provides substantial insight into the interactions between planets in those systems. Secular interactions are those that don't involve knowing where a planet is along its orbit, and they dominate when planets are not involved in mean motion resonances. These interactions exchange angular momentum among the planets, evolving their eccentricities and inclinations. To second order in the planets' eccentricities and inclinations, the eccentricity and inclination perturbations are decoupled. Given the right variable choice, the relevant differential equations are linear and thus the eccentricity and inclination behaviors can be described as a sum of eigenmodes. Since the underlying structure of the secular eigenmodes can be calculated using only the planets' masses and semi-major axes, one can elucidate the eccentricity and inclination behavior of planets in exoplanet systems even without knowing the planets' current eccentricities and inclinations. I have calculated both the eccentricity and inclination secular eigenmodes for the population of known multi-planet systems whose planets have well determined masses and periods. Using this catalog of secular character, I will discuss the prevalence of dynamically grouped planets ('groupies') versus dynamically uncoupled planets ('loners') and how this relates to the exoplanets' long-term eccentricity and inclination behavior. I will also touch on the distribution of the secular eigenfreqiencies.

Artificial tektites: an experimental technique for capturing the shapes of spinning drops

NASA Astrophysics Data System (ADS)

Baldwin, K. A.

2014-12-01

Tektites are small stones formed from rapidly cooling drops of molten rock ejected from high velocity asteroid impacts with the Earth, that freeze into a myriad of shapes during flight. Many splash-form tektites have an elongated or dumb-bell shape owing to their rotation prior to solidification[1]. Here we present a novel method for creating 'artificial tektites' from spinning drops of molten wax, using diamagnetic levitation to suspend the drops[2]. We find that the solid wax models produced this way are the stable equilibrium shapes of a spinning liquid droplet held together by surface tension. In addition to the geophysical interest in tektite formation, the stable equilibrium shapes of liquid drops have implications for many physical phenomena, covering a wide range of length scales, from nuclear physics (e.g. in studies of rapidly rotating atomic nuclei), to astrophysics (e.g. in studies of the shapes of astronomical bodies such as asteroids, rapidly rotating stars and event horizons of rotating black holes). For liquid drops bound by surface tension, analytical and numerical methods predict a series of stable equilibrium shapes with increasing angular momentum. Slowly spinning drops have an oblate-like shape. With increasing angular momentum these shapes become secularly unstable to a series of triaxial pseudo-ellipsoids that then evolve into a family of two-lobed 'dumb-bell' shapes as the angular momentum is increased still further. Our experimental method allows accurate measurements of the drops to be taken, which are useful to validate numerical models. This method has provided a means for observing tektite formation, and has additionally confirmed experimentally the stable equilibrium shapes of liquid drops, distinct from the equivalent shapes of rotating astronomical bodies. Potentially, this technique could be applied to observe the non-equilibrium dynamic processes that are also important in real tektite formation, involving, e.g. viscoelastic effects, non-uniform solidification, surface wrinkling (Schlieren), and rapid separation/fission of dumb-bells via the Rayleigh-Plateau instability. [1] M. R. Stauffer and S. L. Butler, Earth Moon Planets, 107, 169 (2009). [2] R. J. A. Hill and L. Eaves, Phys. Rev. Lett. 101, 234501 (2008).

Secular trends and smoke-free policy development in rural Kentucky

PubMed Central

Fallin, Amanda; Parker, Lindsay; Lindgreen, Janine; Riker, Carol; Kercsmar, Sarah; Hahn, Ellen J.

2011-01-01

Secondhand smoke (SHS) exposure causes cardiovascular disease, lung cancer and pulmonary disorders. Smoke-free policies are the most effective way to prevent exposure to SHS. A 5-year community-based randomized control trial (RCT) is in progress to assess factors associated with smoke-free policy development in rural communities. Considering secular trends is critical when conducting community-based RCTs as they may threaten the internal validity of the study. For the purposes of this paper, secular trends are defined as patterns or recurring events that are not directly related to smoke-free policy but have the potential to influence policy development. There are no established protocols to monitor secular trends in the study of smoke-free policy in rural communities. The purpose of this paper is to (i) describe the development of a protocol to identify and monitor secular trends that may threaten the internal validity of a community-based RCT to promote smoke-free policy development and (ii) describe secular trends identified in the first 2 years of the RCT. The sample includes 854 secular events captured from media outlets covering the 40 study counties over the first 2 years of the RCT. Of these 854 events, there were 281 secular events in Year 1 and 573 in Year 2. This paper focuses on five specific categories: ‘tobacco use and cessation activities’, ‘farming’, ‘economics’, ‘city/county infrastructure’ and ‘wellness’. This protocol is a feasible yet time-intensive method of identifying events that may threaten the internal validity of a community-based RCT. PMID:21558440

Human Rights Education and the Post Secular Turn

ERIC Educational Resources Information Center

Bowie, Bob

2012-01-01

This article questions whether human rights education (HRE) scholarship is responding adequately to the post secular turn in thinking about the place and nature of religion in society. Here the post secular turn is used to describe the discrediting of secularisation theory, the recognition of religion as an enduring and pervasive global cultural…

Secular Ethics Education as an Alternative to Religious Education--Finnish Teachers' Views

ERIC Educational Resources Information Center

Zilliacus, Harriet; Kallioniemi, Arto

2016-01-01

This study provides a Finnish perspective to international discussions on religious and worldviews education through the subject of secular ethics. This subject has been offered in Finland since 1985 throughout comprehensive schools and is primarily directed at students who are non-affiliated. Secular ethics education has scarcely been researched…

Unsafe Gods: Security, Secularism and Schooling

ERIC Educational Resources Information Center

Davies, Lynn

2014-01-01

This book makes the compelling argument that religion can be complicit in conflict and that a new secularism is vital to foster security. Using insights from complexity science, it shows how dynamic secularism can be used to accommodate diverse faiths and beliefs within worldly politics. Exploration of the interplay of religion and education in…

The Other Partition: Religious and Secular Education in British Palestine

ERIC Educational Resources Information Center

Schneider, Suzanne

2014-01-01

The recent critical turn toward post-secularism, particularly on behalf of theorists working from the perspective of Christian societies, has highlighted the difficulty of approaching the history of the Middle East through the binary of religion and secularism. This article argues that such terms are of little explanatory value in and of…

Addressing Religious Plurality--A Teacher Perspective on Minority Religion and Secular Ethics Education

ERIC Educational Resources Information Center

Zilliacus, Harriet

2013-01-01

The Finnish education system recognizes religious plurality by offering education in pupils' own religion or in secular ethics. However, little research has been undertaken on how plurality is addressed in classroom practice. This study investigates how 31 minority religion and secular ethics teachers view the task of supporting and including…

Substitution or Symbiosis? Assessing the Relationship between Religious and Secular Giving

ERIC Educational Resources Information Center

Hill, Jonathan P.; Vaidyanathan, Brandon

2011-01-01

Research on philanthropy has not sufficiently examined whether charitable giving to religious causes impinges on giving to secular causes. Examining three waves of national panel data, we find that the relationship between religious and secular giving is generally not of a zero-sum nature; families that increase their religious giving also…

The effect of secular resonances in the asteroid region between 2.1 and 2.4 AU

NASA Technical Reports Server (NTRS)

Froeschle, Christiane; Scholl, Hans

1992-01-01

The asteroid region between 2.1 and 2.4 AU appears to be depopulated at inclinations i greater than 12 deg. This region is surrounded by the three main secular resonances nu(sub 5), nu(sub 6), and nu(sub 16) and is crossed by higher order secular resonances. Secular resonances appear to overlap in this region. Numerical integrations of the orbits of seventeen fictituous asteroids with initial inclinations 12 deg less than or equal to i less than or equal to 20 deg show the following: (1) this particular asteroid region is not depopulated in our computer experiment on timescales of 2.7 Myrs; (2) inclinations are pumped up by successive crossings through higher order secular resonances while eccentricities are not increased sufficiently to produce planet-crossers; (3) bodies located in the bordering nu(sub 6) resonance with semi-major axes a less than or equal to 2.4 AU become Earth-crossers on a time scale of 1 Myr; and (4) we confirm the result that modes due to higher order secular resonances must be eliminated when proper elements are computed.

Radiometric surveys in underground environment

NASA Astrophysics Data System (ADS)

Bochiolo, Massimo; Chiozzi, Paolo; Verdoya, Massimo; Pasquale, Vincenzo

2010-05-01

Due to their ability to travel through the air for several metres, gamma-rays emitted from natural radioactive elements can be successfully used in surveys carried out both with airborne and ground equipments. Besides the concentration of the radio-elements contained in rocks and soils and the intrinsic characteristics of the gamma-ray detector, the detected count rate depends on the solid angle around the spectrometer. On a flat outcrop, ground spectrometry detects the radiation ideally produced by a cylindrical mass of rock of about two metres in diameter and thickness of about half a meter. Under these geometrical conditions, the natural radioactivity can be easily evaluated. With operating conditions different from the standard ones, such as at the edge of an escarpment, the count rate halves because of the missing material, whereas in the vicinity of a rock wall the count rate will increase. In underground environment, the recorded count rate may even double and the in situ assessment of the concentration of radio-elements may be rather difficult, even if the ratios between the different radio-elements may not be affected. We tested the applicability of gamma-ray spectrometry for rapid assessment of the potential hazard levels related to radon and radiation dose rate in underground environment. A mine shaft, located in a zone of uranium enrichment in Liguria (Italy), has been investigated. A preliminary ground radiometric survey was carried out to define the extent of the ore deposit. Then, the radiometric investigation was focussed on the mine shaft. Due to rock mass above the shaft vault, the background gamma radiation can be considered of negligible influence on measurements. In underground surveys, besides deviations from a flat geometry, factors controlling radon exhalation, emanation and stagnation, such as fractures, water leakage and the presence of ventilation, should be carefully examined. We attempted to evaluate these control factors and collected a set of rock samples along the mine shaft to compare in situ results with high resolution gamma-ray analysis in the laboratory. The comparison points to a systematic overestimation (on the average, by a factor of two) of the uranium, thorium and potassium concentrations obtained with the portable apparatus. The bias between laboratory and field is slightly smaller for potassium and could be due only to deviation from standard geometric conditions. The largest differences occur in uranium concentrations, probably due also to the influence of the activity deriving from radon stagnation. The calculated radon flux depends on the radium specific activity, which, under the assumption of secular radioactive equilibrium, can be easily inferred from the uranium concentration, and the specific exhalation coefficient. Measurements of specific exhalation coefficient are difficult and only few studies have examined unaltered rocks in details. We estimated the values of this parameter by considering the degree of fracturing, width of fissures and evidence of percolating groundwater. In general, the coefficient increases from the entrance, where rocks are more massive, towards the shaft bottom, where closely spaced open fissures, often filled with percolating groundwater, might boost exhalation. As a whole, both potential radon flux and radiation dose values are relevant to radio protection rules.

Scale-covariant theory of gravitation and astrophysical applications

NASA Technical Reports Server (NTRS)

Canuto, V.; Adams, P. J.; Hsieh, S.-H.; Tsiang, E.

1977-01-01

A scale-covariant theory of gravitation is presented which is characterized by a set of equations that are complete only after a choice of the scale function is made. Special attention is given to gauge conditions and units which allow gravitational phenomena to be described in atomic units. The generalized gravitational-field equations are derived by performing a direct scale transformation, by extending Riemannian geometry to Weyl geometry through the introduction of the notion of cotensors, and from a variation principle. Modified conservation laws are provided, a set of dynamical equations is obtained, and astrophysical consequences are considered. The theory is applied to examine certain homogeneous cosmological solutions, perihelion shifts, light deflections, secular variations of planetary orbital elements, stellar structure equations for a star in quasi-static equilibrium, and the past thermal history of earth. The possible relation of the scale-covariant theory to gauge field theories and their predictions of cosmological constants is discussed.

A new momentum management controller for the space station

NASA Technical Reports Server (NTRS)

Wie, B.; Byun, K. W.; Warren, V. W.

1988-01-01

A new approach to CMG (control moment gyro) momentum management and attitude control of the Space Station is developed. The control algorithm utilizes both the gravity-gradient and gyroscopic torques to seek torque equilibrium attitude in the presence of secular and cyclic disturbances. Depending upon mission requirements, either pitch attitude or pitch-axis CMG momentum can be held constant: yaw attitude and roll-axis CMG momentum can be held constant, while roll attitude and yaw-axis CMG momentum cannot be held constant. As a result, the overall attitude and CMG momentum oscillations caused by cyclic aero-dynamic disturbances are minimized. A state feedback controller with minimal computer storage requirement for gain scheduling is also developed. The overall closed-loop system is stable for + or - 30 percent inertia matrix variations and has more than + or - 10 dB and 45 deg stability margins in each loop.

The Role of Secularism of State on the Relationship Between Catholic Identity, Political Orientation, and Gay Rights Issues.

PubMed

Hichy, Zira; Gerges, Mina Halim Helmy; Platania, Silvia; Santisi, Giuseppe

2015-01-01

In discussions of regulations governing same-sex marriage and adoption by gays and lesbians, the issue of state secularism is often called into question. This study aims to test the mediating effects of state secularism on the relationship between Catholic identity, political orientation, and gay civil rights. Participants were Catholic Italians who completed a questionnaire measuring the constructs under investigation. Results showed that state secularism mediates the effects of Catholic identity and political orientation on attitudes toward same-sex marriage and adoption by gays and lesbians.

Secular dynamics of multiplanetary circumbinary systems: stationary solutions and binary-planet secular resonance

NASA Astrophysics Data System (ADS)

Andrade-Ines, Eduardo; Robutel, Philippe

2018-01-01

We present an analytical formalism to study the secular dynamics of a system consisting of N-2 planets orbiting a binary star in outer orbits. We introduce a canonical coordinate system and expand the disturbing function in terms of canonical elliptic elements, combining both Legendre polynomials and Laplace coefficients, to obtain a general formalism for the secular description of this type of configuration. With a quadratic approximation of the development, we present a simplified analytical solution for the planetary orbits for both the single planet and the two-planet cases. From the two-planet model, we show that the inner planet accelerates the precession rate of the binary pericenter, which, in turn, may enter in resonance with the secular frequency of the outer planet, characterizing a secular resonance. We calculate an analytical expression for the approximate location of this resonance and apply it to known circumbinary systems, where we show that it can occur at relatively close orbits, for example at 2.4 au for the Kepler-38 system. With a more refined model, we analyse the dynamics of this secular resonance and we show that a bifurcation of the corresponding fixed points can affect the long- term evolution and stability of planetary systems. By comparing our results with complete integrations of the exact equations of motion, we verified the accuracy of our analytical model.

Environmental radioactivity measurements and applications - Difficulties, current status and future trends

NASA Astrophysics Data System (ADS)

Anagnostakis, Marios J.

2015-11-01

For several decades natural and artificial radioactivity in the environment have been extensively studied all around the world. Nuclear accidents - mainly that of Chernobyl - have led to the development of the field of radioecology, while detector systems and techniques - with predominant that of γ-spectrometry - have been continuously developed through the years to meet researchers' needs. The study of natural radionuclides that was originally limited to 226Ra, 232Th and 40K was then extended to include radionuclides such as 234Th, 210Pb, 235U and 7Be, which allowed the study of radioactive equilibrium. Besides their importance from the radiation protection point of view, many radionuclides are also used as tracers of environmental processes, such as aerosol and transportation of air masses studies (7Be, 10Be, 22Na), soil erosion, sedimentation and geochronology (210Pb, 137Cs), marine ecosystems studies and studies related to climate change. All these studies require specialized samplings strategies and sampling preparation techniques as well as high quality measurements, while the improvement of detection limits is often of vital importance. This work is a review of environmental radioactivity measurements and applications, mainly focused in the field of γ-spectrometry, for which difficulties and limitations will be presented, together with future trends, new challenges and applications.

Synergistically strengthened 3D micro-scavenger cage adsorbent for selective removal of radioactive cesium

PubMed Central

Jang, Sung-Chan; Kang, Sung-Min; Haldorai, Yuvaraj; Giribabu, Krishnan; Lee, Go-Woon; Lee, Young-Chul; Hyun, Moon Seop; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

2016-01-01

A novel microporous three-dimensional pomegranate-like micro-scavenger cage (P-MSC) composite has been synthesized by immobilization of iron phyllosilicates clay onto a Prussian blue (PB)/alginate matrix and tested for the removal of radioactive cesium from aqueous solution. Experimental results show that the adsorption capacity increases with increasing the inactive cesium concentration from 1 ppm to 30 ppm, which may be attributed to greater number of adsorption sites and further increase in the inactive cesium concentration has no effect. The P-MSC composite exhibit maximum adsorption capacity of 108.06 mg of inactive cesium per gram of adsorbent. The adsorption isotherm is better fitted to the Freundlich model than the Langmuir model. In addition, kinetics studies show that the adsorption process is consistent with a pseudo second-order model. Furthermore, at equilibrium, the composite has an outstanding adsorption capacity of 99.24% for the radioactive cesium from aqueous solution. This may be ascribed to the fact that the AIP clay played a substantial role in protecting PB release from the P-MSC composite by cross-linking with alginate to improve the mechanical stability. Excellent adsorption capacity, easy separation, and good selectivity make the adsorbent suitable for the removal of radioactive cesium from seawater around nuclear plants and/or after nuclear accidents. PMID:27917913

Synergistically strengthened 3D micro-scavenger cage adsorbent for selective removal of radioactive cesium.

PubMed

Jang, Sung-Chan; Kang, Sung-Min; Haldorai, Yuvaraj; Giribabu, Krishnan; Lee, Go-Woon; Lee, Young-Chul; Hyun, Moon Seop; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

2016-12-05

A novel microporous three-dimensional pomegranate-like micro-scavenger cage (P-MSC) composite has been synthesized by immobilization of iron phyllosilicates clay onto a Prussian blue (PB)/alginate matrix and tested for the removal of radioactive cesium from aqueous solution. Experimental results show that the adsorption capacity increases with increasing the inactive cesium concentration from 1 ppm to 30 ppm, which may be attributed to greater number of adsorption sites and further increase in the inactive cesium concentration has no effect. The P-MSC composite exhibit maximum adsorption capacity of 108.06 mg of inactive cesium per gram of adsorbent. The adsorption isotherm is better fitted to the Freundlich model than the Langmuir model. In addition, kinetics studies show that the adsorption process is consistent with a pseudo second-order model. Furthermore, at equilibrium, the composite has an outstanding adsorption capacity of 99.24% for the radioactive cesium from aqueous solution. This may be ascribed to the fact that the AIP clay played a substantial role in protecting PB release from the P-MSC composite by cross-linking with alginate to improve the mechanical stability. Excellent adsorption capacity, easy separation, and good selectivity make the adsorbent suitable for the removal of radioactive cesium from seawater around nuclear plants and/or after nuclear accidents.

Synergistically strengthened 3D micro-scavenger cage adsorbent for selective removal of radioactive cesium

NASA Astrophysics Data System (ADS)

Jang, Sung-Chan; Kang, Sung-Min; Haldorai, Yuvaraj; Giribabu, Krishnan; Lee, Go-Woon; Lee, Young-Chul; Hyun, Moon Seop; Han, Young-Kyu; Roh, Changhyun; Huh, Yun Suk

2016-12-01

A novel microporous three-dimensional pomegranate-like micro-scavenger cage (P-MSC) composite has been synthesized by immobilization of iron phyllosilicates clay onto a Prussian blue (PB)/alginate matrix and tested for the removal of radioactive cesium from aqueous solution. Experimental results show that the adsorption capacity increases with increasing the inactive cesium concentration from 1 ppm to 30 ppm, which may be attributed to greater number of adsorption sites and further increase in the inactive cesium concentration has no effect. The P-MSC composite exhibit maximum adsorption capacity of 108.06 mg of inactive cesium per gram of adsorbent. The adsorption isotherm is better fitted to the Freundlich model than the Langmuir model. In addition, kinetics studies show that the adsorption process is consistent with a pseudo second-order model. Furthermore, at equilibrium, the composite has an outstanding adsorption capacity of 99.24% for the radioactive cesium from aqueous solution. This may be ascribed to the fact that the AIP clay played a substantial role in protecting PB release from the P-MSC composite by cross-linking with alginate to improve the mechanical stability. Excellent adsorption capacity, easy separation, and good selectivity make the adsorbent suitable for the removal of radioactive cesium from seawater around nuclear plants and/or after nuclear accidents.

Faith and Reason in a Post Secular Age

ERIC Educational Resources Information Center

Radford, Mike

2012-01-01

The problems that this article seeks to address are those that are raised in the context of the bilateralism that is established when we think in terms of secularism as primarily orientated towards reason and post secularism, towards faith. The objective of the article is to show that the distinction between the two can be collapsed. Post…

"Doing the Secular": Academic Practices in the Study of Religion at Two Danish Universities

ERIC Educational Resources Information Center

Johansen, Birgitte Schepelern

2011-01-01

The academic study of religion at the public university often presents itself as a secular, non-religious, scientific endeavor. The identity of the study is thus firmly rooted within one of the central secular-religious divides, namely that between science and religion. Based on the assumption that such distinctions between religion and the…

One Size Does Not Fit All: Complexity, Religion, Secularism and Education

ERIC Educational Resources Information Center

Davies, Lynn

2014-01-01

The continuing incidence of extremist acts committed in the name of religion underscores the need to examine the interplay between religion and learning. This article argues for a secular foundation in society and school to protect against religion contributing to conflict and extremism. However, this is not a hard version of secularism, but a…

The Secular University and Its Critics

ERIC Educational Resources Information Center

Jobani, Yuval

2016-01-01

Universities in the USA have become bastions of secularity in a distinctly religious society. As such, they are subjected to a variety of robust and rigorous religious critiques. In this paper I do not seek to engage in the debate between the supporters of the secular university and its opponents. Furthermore, I do not claim to summarize the…

Disruptive Behaviour in Religious and Secular High Schools: Teachers' and Students' Attitudes

ERIC Educational Resources Information Center

Romi, Shlomo

2004-01-01

This two-phase study, conducted in religious and secular high schools, investigated the attitudes of teachers and students to disruptive behaviour. The first phase examined a religious school, then applied the same research tools to a secular school. It was assumed that differences of attitude would be found, with teachers viewing disruptive…

Unholy Trinity? Secularism Institute Renews Liberal Arts Curriculum

ERIC Educational Resources Information Center

Keysar, Ariela

2010-01-01

Secularism is controversial in today's political debates, championed by some and vilified by others. So when Trinity College in Hartford, Conn., opened a center for the study of secularism in September 2005, some people worried that it could become a source of friction on campus--yet another battleground in the culture wars that are wreaking havoc…

Habermas and the Meaning of the Post-Secular Society: Complementary Learning Processes

ERIC Educational Resources Information Center

Welton, Michael R.

2014-01-01

This essay argues that if social justice is to prevail in our world, we must understand the post-secular nature of our globalized society as a prerequisite for moving beyond "might is right" to national and international relations that heed all voices towards evidence-based interaction. Our post-secular world and postmetaphysical…

On the secular change of spring onset at Stockholm

NASA Astrophysics Data System (ADS)

Qian, Cheng; Fu, Congbin; Wu, Zhaohua; Yan, Zhongwei

2009-06-01

A newly developed method, the Ensemble Empirical Mode Decomposition, was applied to adaptively determine the timing of climatic spring onset from the daily temperature records at Stockholm during 1756-2000. Secular variations of spring onset and its relationships to the North Atlantic Oscillation (NAO) and to the temperature variability were analyzed. A clear turning point of secular trend in spring onset around 1884/1885, from delaying to advancing, was found. The delaying trend of spring onset (6.9 days/century) during 1757-1884 and the advancing one (-7 days/century) during 1885-1999 were both significant. The winter NAO indices were found to be correlated with the spring onset at Stockholm at an inter-annual timescale only for some decades, but unable to explain the change of the long-term trends. The secular change from cooling to warming around the 1880s, especially in terms of spring temperature, might have led to the secular change of spring onset.

Sex, secularism and religious influence in US politics.

PubMed

Bernstein, Elizabeth; Jakobsen, Janet R

2010-01-01

Through an analysis of alliances between secular and religious actors in US politics and a specific case study on anti-trafficking policy, we show that the intertwining of religion and politics in the US comes from two sources: 1) the secular political and cultural institutions of American public life that have developed historically out of Protestantism, and which predominantly operate by presuming Protestant norms and values; and 2) the direct influence on US politics of religious groups and organisations, particularly in the past quarter-century of lobby groups and political action committees identified with conservative evangelical Christianity. The sources of policies that promote gender and sexual inequality in the US are both secular and religious and we conclude that it is inaccurate to assume that religious influence in politics is necessarily conservative or that more secular politics will necessarily be more progressive than the religious varieties.

Scavenging of radioactive soluble gases from inhomogeneous atmosphere by evaporating rain droplets.

PubMed

Elperin, Tov; Fominykh, Andrew; Krasovitov, Boris

2015-05-01

We analyze effects of inhomogeneous concentration and temperature distributions in the atmosphere, rain droplet evaporation and radioactive decay of soluble gases on the rate of trace gas scavenging by rain. We employ a one-dimensional model of precipitation scavenging of radioactive soluble gaseous pollutants that is valid for small gradients and non-uniform initial altitudinal distributions of temperature and concentration in the atmosphere. We assume that conditions of equilibrium evaporation of rain droplets are fulfilled. It is demonstrated that transient altitudinal distribution of concentration under the influence of rain is determined by the linear wave equation that describes propagation of a scavenging wave front. The obtained equation is solved by the method of characteristics. Scavenging coefficients are calculated for wet removal of gaseous iodine-131 and tritiated water vapor (HTO) for the exponential initial distribution of trace gases concentration in the atmosphere and linear temperature distribution. Theoretical predictions of the dependence of the magnitude of the scavenging coefficient on rain intensity for tritiated water vapor are in good agreement with the available atmospheric measurements. Copyright © 2015 Elsevier Ltd. All rights reserved.

Connecting the U-Th and U-Pb Chronometers: New Algorithms and Applications

NASA Astrophysics Data System (ADS)

McLean, N. M.; Smith, C. J. M.; Roberts, N. M. W.; Richards, D. A.

2016-12-01

The U-Th and U-Pb geochronometers are important clocks for separate intervals of the geologic timescale. U-Th dates exploit disequilibrium in the 238U intermediate daughter isotopes 234U and 230Th, and are often used to date corals and speleothems that are zero age through 800 ka. The U-Pb system relies on secular equilibrium decay of 238U to 206Pb and 235U to 207Pb over longer timescales, and can be used to date samples from <1 Ma to 4.5 Ga. Disequilibrium plays a role in young U-Pb dates, but only as a nuisance correction. Both chronometers can produce dates with uncertainties <0.1% near the center of their applicable age ranges, but become less precise at their intersection, when the 238U decay chain approaches secular equilibrium and there has been little time for ingrowth of radiogenic Pb. However, if measurements or assumptions about both chronometers can be made, then they can be combined into a single, more informed date. Coupling the datasets can improve their precision and accuracy and help interrogate the assumptions that underpin each. Working with this data is difficult for two reasons. The Bateman equations are long and cumbersome for U decay chains that include 238U, 234U, 230Th, 226Ra, 206Pb and 235U, 231Pa, and 207Pb. Also, Pb measurements often comprise varying amounts of radiogenic Pb from locally heterogeneous U concentrations mixed with varying amounts of common Pb. At present there is no established, flexible computational framework to combine information from measurements and/or assumptions of these parameters, and no way to visualize and interpret the results. We present new algorithms to quickly and accurately solve the system of differential equations defined by both of the uranium decay chains and the linear regression through the U-Pb isochron. The results are illustrated on a new concordia diagram, where the concordia curve is determined by measured and/or assumed U-series disequilibrium and can have unfamiliar topologies. We demonstrate this approach using data collected by solution and laser ablation ICPMS on carbonates with measurable 230Th and 234U disequilibrium, measurable disequilibrium for only 234U, and when only assumptions can be made about initial U-series disequilibrium. Potential applications include refining chronologies at ca. 1 Ma, an important period in Earth history.

Ten-Year Secular Trends in Youth Violence: Results from the Philadelphia Youth Risk Behavior Survey 2003-2013

ERIC Educational Resources Information Center

Pool, Andrew C.; Patterson, Freda; Luna, Ingrid Y.; Hohl, Bernadette; Bauer, Katherine W.

2017-01-01

Background: Youth violence reduction is a public health priority, yet few studies have examined secular trends in violence among urban youth, who may be particularly vulnerable to numerous forms of violence. This study examines 10-year secular trends in the prevalence of violence-related behaviors among Philadelphia high school students. Methods:…

Secular dynamics of hierarchical multiple systems composed of nested binaries, with an arbitrary number of bodies and arbitrary hierarchical structure - II. External perturbations: flybys and supernovae

NASA Astrophysics Data System (ADS)

Hamers, Adrian S.

2018-05-01

We extend the formalism of a previous paper to include the effects of flybys and instantaneous perturbations such as supernovae on the long-term secular evolution of hierarchical multiple systems with an arbitrary number of bodies and hierarchy, provided that the system is composed of nested binary orbits. To model secular encounters, we expand the Hamiltonian in terms of the ratio of the separation of the perturber with respect to the barycentre of the multiple system, to the separation of the widest orbit. Subsequently, we integrate over the perturber orbit numerically or analytically. We verify our method for secular encounters and illustrate it with an example. Furthermore, we describe a method to compute instantaneous orbital changes to multiple systems, such as asymmetric supernovae and impulsive encounters. The secular code, with implementation of the extensions described in this paper, is publicly available within AMUSE, and we provide a number of simple example scripts to illustrate its usage for secular and impulsive encounters and asymmetric supernovae. The extensions presented in this paper are a next step towards efficiently modelling the evolution of complex multiple systems embedded in star clusters.

Secular Evolution of Spiral Galaxies

DTIC Science & Technology

2003-01-01

recombination (z=1000). Furthermore, the BigBang nucleosynthesis model also requires a signi cantamount of non- baryonic dark matter (Primack 1999) ifthe universe...momentum (as well as energy) outward. Associ-ated with this outward angular momentum transport isan expected secular redistribution of disk matter , co...mode, a secular transfer of energy andangular momentum between the disk matter and thedensity wave. The existence of the phase shift betweenthe

[Nursing care at home and secularism].

PubMed

Lecointre, Brigitte

2015-12-01

The question of secularism, long-time confined to schools and the relationships between the Church and State, is today being raised in the field of public health. Nurses are directly affected and are integrating this dimension of secularism into their care practices. A private practice nurse describes the effect these changes are having on her practice in patients' homes. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

What Lies between the Religious and the Secular?: Education beyond the Human

ERIC Educational Resources Information Center

Seo, Yong-Seok

2014-01-01

The current age is characterised by many as secular, and a source of such a characterisation can be found in the Nietzschean claim that thoughts about there being some ultimate reality have to be jettisoned, and human existence and the world need to be embraced as they are. That claim is renewed by some secular thinkers who insist that education…

Study of evaporating the irradiated graphite in equilibrium low-temperature plasma

NASA Astrophysics Data System (ADS)

Bespala, E. V.; Novoselov, I. Yu.; Pavlyuk, A. O.; Kotlyarevskiy, S. G.

2018-01-01

The paper describes a problem of accumulation of irradiated graphite due to operation of uranium-graphite nuclear reactors. The main noncarbon contaminants that contribute to the overall activity of graphite elements are iso-topes 137Cs, 60Co, 90Sr, 36Cl, and 3H. A method was developed for processing of irradiated graphite ensuring the volu-metric decontamination of samples. The calculation results are presented for equilibrium composition of plasma-chemical reactions in systems "irradiated graphite-argon" and "irradiated graphite-helium" for a wide range of tem-peratures. The paper describes a developed mathematical model for the process of purification of a porous graphite surface treated by equilibrium low-temperature plasma. The simulation results are presented for the rate of sublimation of radioactive contaminants as a function of plasma temperature and plasma flow velocity when different plasma-forming gases are used. The extraction coefficient for the contaminant 137Cs from the outer side of graphite pores was calculated. The calculations demonstrated the advantages of using a lighter plasma forming gas, i.e., helium.

Craniofacial Secular Change in Recent Mexican Migrants.

PubMed

Spradley, Katherine; Stull, Kyra E; Hefner, Joseph T

2016-01-01

Research by economists suggests that recent Mexican migrants are better educated and have higher socioeconomic status (SES) than previous migrants. Because factors associated with higher SES and improved education can lead to positive secular changes in overall body form, secular changes in the craniofacial complex were analyzed within a recent migrant group from Mexico. The Mexican group represents individuals in the act of migration, not yet influenced by the American environment, and thus can serve as a starting point for future studies of secular change in this population group. The excavation of a historic Hispanic cemetery in Tucson, Arizona, also allows for a comparison between historic Hispanics and recent migrants to explore craniofacial trends over a broad time period, as both groups originate from Mexico. The present research addresses two main questions: (1) Are cranial secular changes evident in recent Mexican migrants? (2) Are historic Hispanics and recent Mexican migrants similar? By studying secular changes within a migrant population group, secular trends may be detected, which will be important for understanding the biological variation of the migrants themselves and will serve as a preliminary investigation of secular change within Mexican migrants. The comparison of a sample of recent Mexican migrants with a historic Hispanic sample, predominantly of Mexican origin, allows us to explore morphological similarities and differences between early and recent Mexicans within the United States. Vault and face size and a total of 82 craniofacial interlandmark distances were used to explore secular changes within the recent Mexican migrants (females, n = 38; males, n = 178) and to explore the morphological similarities between historic Hispanics (females, n = 54; males, n = 58) and recent migrants. Sexes were separated, and multivariate adaptive regression splines and basis splines (quadratic with one knot) were used to assess the direction and magnitude of secular trends for the recent Mexican migrants. Because dates of birth were unavailable for the historic sample, partial least squares discriminant analysis (PLS-DA) was used to evaluate morphological differences between historic and recent Mexican migrant samples. The data were separated into a training data set and a testing data set to ensure realistic results. Males had eight variables (four positive and four negative) and females had six variables (two positive and four negative) that demonstrated significant differences over time. In the PLS-DA, three components were identified as important in model creation and resulted in a classification accuracy of 87% when applied to a testing sample. The high classification accuracy demonstrates significant morphological differences between the two groups, with the historic Hispanic sample displaying overall larger craniofacial dimensions. While differences in cranial morphology are evident between historic Hispanics and recent Mexican migrants, relatively few positive and negative secular trends were detected within the recent migrant sample.

Secular humanism and "scientific psychiatry".

PubMed

Szasz, Thomas

2006-04-25

The Council for Secular Humanism identifies Secular Humanism as a "way of thinking and living" committed to rejecting authoritarian beliefs and embracing "individual freedom and responsibility ... and cooperation." The paradigmatic practices of psychiatry are civil commitment and insanity defense, that is, depriving innocent persons of liberty and excusing guilty persons of their crimes: the consequences of both are confinement in institutions ostensibly devoted to the treatment of mental diseases. Black's Law Dictionary states: "Every confinement of the person is an 'imprisonment,' whether it be in a common prison, or in private house, or in the stocks, or even by forcibly detaining one in the public streets." Accordingly, I maintain that Secular Humanism is incompatible with the principles and practices of psychiatry.

Analysis of geomagnetic secular variation during 1980-1985 and 1985- 1990, and geomagnetic models proposed for the 1991 revision of the International Geomagnetic Reference Field

USGS Publications Warehouse

Peddie, N.W.

1992-01-01

The secular variation of the main geomagnetic field during the periods 1980-1985 and 1985-1990 was analyzed in terms of spherical harmonics up to the eighth degree and order. Data from worldwide magnetic observatories and the Navy's Project MAGNET aerial surveys were used. The resulting pair of secular-variation models was used to update the Definitive Geomagnetic Reference Field (DGRF) model for 1980, resulting in new mainfield models for 1985.0 and 1990.0. These, along with the secular-variation model for 1985-1990, were proposed for the 1991 revision of the International Geomagnetic Reference Field (IGRF). -Author

Sacred Spaces: Religious and Secular Coping and Family Relationships in the Neonatal Intensive Care Unit.

PubMed

Brelsford, Gina M; Ramirez, Joshua; Veneman, Kristin; Doheny, Kim K

2016-08-01

Preterm birth is an unanticipated and stressful event for parents. In addition, the unfamiliar setting of the intensive care nursery necessitates strategies for coping. The primary study objective of this descriptive study was to determine whether secular and religious coping strategies were related to family functioning in the neonatal intensive care unit. Fifty-two parents of preterm (25-35 weeks' gestation) infants completed the Brief COPE (secular coping), the Brief RCOPE (religious coping), and the Family Environment Scale within 1 week of their infant's hospital admission. This descriptive study found that parents' religious and secular coping was significant in relation to family relationship functioning. Specifically, negative religious coping (ie, feeling abandoned or angry at God) was related to poorer family cohesion and use of denial. These findings have relevance for interventions focused toward enhancing effective coping for families. Further study of religious and secular coping strategies for neonatal intensive care unit families is warranted in a larger more diverse sample of family members.

Evaluating secular acceleration in geomagnetic field model GRIMM-3

NASA Astrophysics Data System (ADS)

Lesur, V.; Wardinski, I.

2012-12-01

Secular acceleration of the magnetic field is the rate of change of its secular variation. One of the main results of studying magnetic data collected by the German survey satellite CHAMP was the mapping of field acceleration and its evolution in time. Questions remain about the accuracy of the modeled acceleration and the effect of the applied regularization processes. We have evaluated to what extent the regularization affects the temporal variability of the Gauss coefficients. We also obtained results of temporal variability of the Gauss coefficients where alternative approaches to the usual smoothing norms have been applied for regularization. Except for the dipole term, the secular acceleration of the Gauss coefficients is fairly well described up to spherical harmonic degree 5 or 6. There is no clear evidence from observatory data that the spectrum of this acceleration is underestimated at the Earth surface. Assuming a resistive mantle, the observed acceleration supports a characteristic time scale for the secular variation of the order of 11 years.

N-body simulations of collective effects in spiral and barred galaxies

NASA Astrophysics Data System (ADS)

Zhang, X.

2016-10-01

We present gravitational N-body simulations of the secular morphological evolution of disk galaxies induced by density wave modes. In particular, we address the demands collective effects place on the choice of simulation parameters, and show that the common practice of the use of a large gravity softening parameter was responsible for the failure of past simulations to correctly model the secular evolution process in galaxies, even for those simulations where the choice of basic state allows an unstable mode to emerge, a prerequisite for obtaining the coordinated radial mass flow pattern needed for secular evolution of galaxies along the Hubble sequence. We also demonstrate that the secular evolution rates measured in our improved simulations agree to an impressive degree with the corresponding rates predicted by the recently-advanced theories of dynamically-driven secular evolution of galaxies. The results of the current work, besides having direct implications on the cosmological evolution of galaxies, also shed light on the general question of how irreversibility emerges from a nominally reversible physical system.

Zero secular torque on asteroids from impinging solar photons in the YORP effect: A simple proof

NASA Astrophysics Data System (ADS)

Rubincam, David Parry; Paddack, Stephen J.

2010-10-01

YORP torques, where "YORP" stands for "Yarokovsky-O'Keefe-Radzievskii-Paddack," arise mainly from sunlight reflected off a Solar System object and the infrared radiation emitted by it. We show here, through the most elementary demonstration that we can devise, that secular torques from impinging solar photons are generally negligible and thus cause little secular evolution of an asteroid's obliquity or spin rate.

Technical Limitations in Merging Secular and Sacred Functions in Monumental Churches

NASA Astrophysics Data System (ADS)

Piatkowska, Ksenia

2017-10-01

The abandonment of churches and their adaptation for secular purposes is a current subject in Europe and worldwide. Most cases involve objects that were desacralized and then rebuilt as a whole object for alternative functions. Thus far, the merging of secular and sacred functions in one monumental Catholic church has not raised any issues. The paper describes the case of St. Catherine’s Church in Gdansk, Poland, where sacred function exists parallel to the new secular function being implemented. The study is based on the authentic, professional experience of the author. It describes the technical limitations arising from the need to ensure destinies for the optimal conditions of both sacred and secular function, while avoiding undesirable interference between them. The author further identifies architectural solutions most relevant to current requirements for protection of sacred zones in the church, for preservation of the monument, and for optimal function of a modern science museum. Significant design issues include: the inviolability of the sacred zone, preservation of the historical value of the monument, proper operation of new secular zones in compliance with contemporary standards of safety, performance of the assumed mission and profitability. The research indicates specific areas where the highest probability of collision exists between the sacred and profane and where technical problems are likely to occur.

Variations of anthropogenic CO2 in urban area deduced by radiocarbon concentration in modern tree rings.

PubMed

Rakowski, Andrzej Z; Nakamura, Toshio; Pazdur, Anna

2008-10-01

Radiocarbon concentration in the atmosphere is significantly lower in areas where man-made emissions of carbon dioxide occur. This phenomenon is known as Suess effect, and is caused by the contamination of clean air with non-radioactive carbon from fossil fuel combustion. The effect is more strongly observed in industrial and densely populated urban areas. Measurements of carbon isotope concentrations in a study area can be compared to those from areas of clear air in order to estimate the amount of carbon dioxide emission from fossil fuel combustion by using a simple mathematical model. This can be calculated using the simple mathematical model. The result of the mathematical model followed in this study suggests that the use of annual rings of trees to obtain the secular variations of 14C concentration of atmospheric CO2 can be useful and efficient for environmental monitoring and modeling of the carbon distribution in local scale.

Comparison of Cf-252 thin-film sources prepared by evaporation or self-transfer

DOE PAGES

Algutifan, Noor J.; Sherman, Steven R.; Alexander, Charles W.

2014-11-29

Californium-252 (Z = 98) is valued as a potent neutron source due to its spontaneous fission decay path. Thin film sources containing Cf-252 were prepared by two techniques: evaporation and self-transfer. The sources were analyzed by alpha and gamma spectroscopy. Results indicate that self-transfer sources exhibit less alpha energy straggling and energy loss than evaporative sources. Fission fragments may also self-transfer, and sources made by self-transfer may need some decay time to reach radioactive equilibrium.

Zero Secular Torque on Asteroids from Impinging Solar Photons in the YORP Effect: A Simple Proof

NASA Technical Reports Server (NTRS)

Rubincam, David Perry; Paddack, Stephen J.

2010-01-01

YORP torques, where "YORP" stands for "Yarokovsky-O'Keefe-Radzievskii-Paddack." arise mainly from sun light reflected off a Solar System object and the infrared radiation emi tted by it. We show here, through the most elementary demonstration that we Can devise, that secular torques from impinging solar photons are generally negligible and thus cause little secular evolution of an asteroid's obliquity or spin rate.

"Text-Books and Textpeople" (A. J. Heschel): What Is the Role of the Mehanekh in the Jewish Secular High School in Israel, and What Is the Place of Jewish Texts within That Role?

ERIC Educational Resources Information Center

Sela Kol, Aviva Helena

2011-01-01

My study concerns the teacher knowledge of "mehankhim," teachers in Israeli high schools entrusted to promote students' moral, civic, and social growth. It examines two "mehankhim" from a secular Israeli high school who participated in a long-term professional development program in secular Jewish education, centered by…

Secular humanism and "scientific psychiatry"

PubMed Central

Szasz, Thomas

2006-01-01

The Council for Secular Humanism identifies Secular Humanism as a "way of thinking and living" committed to rejecting authoritarian beliefs and embracing "individual freedom and responsibility ... and cooperation." The paradigmatic practices of psychiatry are civil commitment and insanity defense, that is, depriving innocent persons of liberty and excusing guilty persons of their crimes: the consequences of both are confinement in institutions ostensibly devoted to the treatment of mental diseases. Black's Law Dictionary states: "Every confinement of the person is an 'imprisonment,' whether it be in a common prison, or in private house, or in the stocks, or even by forcibly detaining one in the public streets." Accordingly, I maintain that Secular Humanism is incompatible with the principles and practices of psychiatry. PMID:16759353

On the consequences of strong stable stratification at the top of earth's outer core

NASA Technical Reports Server (NTRS)

Bloxham, Jeremy

1990-01-01

The consequences of strong stable stratification at the top of the earth's fluid outer core are considered, concentrating on the generation of the geomagnetic secular variation. It is assumed that the core near the core-mantle boundary is both strongly stably stratified and free of Lorentz forces: it is found that this set of assumptions severely limits the class of possible motions, none of which is compatible with the geomagnetic secular variation. Relaxing either assumption is adequate: tangentially geostrophic flows are consistent with the secular variation if the assumption that the core is strongly stably stratified is relaxed (while retaining the assumption that Lorentz forces are negligible); purely toroidal flows may explain the secular variation if Lorentz forces are included.

Emission lineshapes of the B850 band of light-harvesting 2 (LH2) complex in purple bacteria: a second order time-nonlocal quantum master equation approach.

PubMed

Kumar, Praveen; Jang, Seogjoo

2013-04-07

The emission lineshape of the B850 band in the light harvesting complex 2 of purple bacteria is calculated by extending the approach of 2nd order time-nonlocal quantum master equation [S. Jang and R. J. Silbey, J. Chem. Phys. 118, 9312 (2003)]. The initial condition for the emission process corresponds to the stationary excited state density where exciton states are entangled with the bath modes in equilibrium. This exciton-bath coupling, which is not diagonal in either site excitation or exciton basis, results in a new inhomogeneous term that is absent in the expression for the absorption lineshape. Careful treatment of all the 2nd order terms are made, and explicit expressions are derived for both full 2nd order lineshape expression and the one based on secular approximation that neglects off-diagonal components in the exciton basis. Numerical results are presented for a few representative cases of disorder and temperature. Comparison of emission line shape with the absorption line shape is also made. It is shown that the inhomogeneous term coming from the entanglement of the system and bath degrees of freedom makes significant contributions to the lineshape. It is also found that the perturbative nature of the theory can result in negative portion of lineshape in some situations, which can be removed significantly by inclusion of the inhomogeneous term and completely by using the secular approximation. Comparison of the emission and absorption lineshapes at different temperatures demonstrates the role of thermal population of different exciton states and exciton-phonon couplings.

Fast rotating neutron stars with realistic nuclear matter equation of state

NASA Astrophysics Data System (ADS)

Cipolletta, F.; Cherubini, C.; Filippi, S.; Rueda, J. A.; Ruffini, R.

2015-07-01

We construct equilibrium configurations of uniformly rotating neutron stars for selected relativistic mean-field nuclear matter equations of state (EOS). We compute, in particular, the gravitational mass (M ), equatorial (Req) and polar (Rpol) radii, eccentricity, angular momentum (J ), moment of inertia (I ) and quadrupole moment (M2) of neutron stars stable against mass shedding and secular axisymmetric instability. By constructing the constant frequency sequence f =716 Hz of the fastest observed pulsar, PSR J1748-2446ad, and constraining it to be within the stability region, we obtain a lower mass bound for the pulsar, Mmin=[1.2 - 1.4 ]M⊙ , for the EOS employed. Moreover, we give a fitting formula relating the baryonic mass (Mb) and gravitational mass of nonrotating neutron stars, Mb/M⊙=M /M⊙+(13 /200 )(M /M⊙)2 [or M /M⊙=Mb/M⊙-(1 /20 )(Mb/M⊙)2], which is independent of the EOS. We also obtain a fitting formula, although not EOS independent, relating the gravitational mass and the angular momentum of neutron stars along the secular axisymmetric instability line for each EOS. We compute the maximum value of the dimensionless angular momentum, a /M ≡c J /(G M2) (or "Kerr parameter"), (a /M )max≈0.7 , found to be also independent of the EOS. We then compare and contrast the quadrupole moment of rotating neutron stars with the one predicted by the Kerr exterior solution for the same values of mass and angular momentum. Finally, we show that, although the mass quadrupole moment of realistic neutron stars never reaches the Kerr value, the latter is closely approached from above at the maximum mass value, as physically expected from the no-hair theorem. In particular, the stiffer the EOS, the closer the mass quadrupole moment approaches the value of the Kerr solution.

SU-G-201-16: Thermal Imaging in Source Visualization and Radioactivity Measurement for High Dose Rate Brachytherapy

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

Zhu, X; Lei, Y; Zheng, D

2016-06-15

Purpose: High Dose Rate (HDR) brachytherapy poses a special challenge to radiation safety and quality assurance (QA) due to its high radioactivity, and it is thus critical to verify the HDR source location and its radioactive strength. This study demonstrates a new method for measuring HDR source location and radioactivity utilizing thermal imaging. A potential application would relate to HDR QA and safety improvement. Methods: Heating effects by an HDR source were studied using Finite Element Analysis (FEA). Thermal cameras were used to visualize an HDR source inside a plastic applicator made of polyvinylidene difluoride (PVDF). Using different source dwellmore » times, correlations between the HDR source strength and heating effects were studied, thus establishing potential daily QA criteria using thermal imaging Results: For an Ir1?2 source with a radioactivity of 10 Ci, the decay-induced heating power inside the source is ∼13.3 mW. After the HDR source was extended into the PVDF applicator and reached thermal equilibrium, thermal imaging visualized the temperature gradient of 10 K/cm along the PVDF applicator surface, which agreed with FEA modeling. For Ir{sup 192} source activities ranging from 4.20–10.20 Ci, thermal imaging could verify source activity with an accuracy of 6.3% with a dwell time of 10 sec, and an accuracy of 2.5 % with 100 sec. Conclusion: Thermal imaging is a feasible tool to visualize HDR source dwell positions and verify source integrity. Patient safety and treatment quality will be improved by integrating thermal measurements into HDR QA procedures.« less

Mechanism and kinetics of uranium adsorption onto soil around coal-fired power plant

NASA Astrophysics Data System (ADS)

Yasim, Nurzulaifa Shaheera Erne Mohd; Ariffin, Nik Azlin Nik; Mohammed, Noradila; Ayob, Syafina

2017-11-01

Coal is the largest source of energy in Malaysia providing approximately 80 % of all entire power needs. The combustion of coal concentrates a high content of heavy metals and radioactive elements in the ashes and sludge. Hazardous emissions from coal combustion were deposited into the soil and most likely transported into the groundwater system. The presence of radioactive materials in the ground water system can cause a wide range of environmental impacts and adverse health effects like cancer, impairment of neurological function and cardiovascular disease. However, the soil has a natural capability in adsorption of radioactive materials. Thus, this study was evaluated the adsorption capacity of Uranium onto the soil samples collected nearby the coal-fired power plants. In the batch experiment, parameters that were set constant include pH, the amount of soil and contact time. Various initial concentrations of radionuclides elements in the range of 2 mg/L - 10 mg/L were used. The equilibrium adsorption data was analyzed by the Freundlich isotherm and Langmuir isotherms. Then, the influences of solution pH, contact time and temperature on the adsorption process were investigated. The kinetics of radioactive materials was discussed by pseudo-first-order and pseudo-second-order rate equation. Thus, the data from this study could provide information about the potentiality of soil in sorption of radioactive materials that can be leached into groundwater. Besides that, this study could also be used as baseline data for future reference in the development of adsorption modeling in the calculation of distribution coefficient.

Assessment of the 3H and 7Be generation in the IFMIF lithium loop

NASA Astrophysics Data System (ADS)

Simakov, S. P.; Fischer, U.; von Möllendorff, U.

2004-08-01

A complete evaluation of the 7Be and tritium inventory induced in the IFMIF lithium loop by deuterons and neutrons was performed on the basis of 3D Monte Carlo calculations with the M CDeLicious code and evaluated d-Li and n-Li cross-section data. The associated reaction cross-sections and thick lithium target yields were checked against available experimental data. The IFMIF calculations showed that the deuteron beam will produce 1.5 g of 7Be and 6 g of 3H per full power year in the lithium jet. The tritium generation in the whole lithium loop due to neutron induced reactions is at a rate of 1.5 g/fpy. The radio-active decay results in an equilibrium concentration 0.3 mg of 7Be and 50 mg of 3H per 1 kg of circulating lithium if no radioactive products are removed from the loop.

Secular change in the growth status of urban and rural schoolchildren aged 6-13 years in Oaxaca, southern Mexico.

PubMed

Malina, Robert M; Peña Reyes, Maria Eugenia; Little, Bertis B

2008-01-01

Populations in the state of Oaxaca in southern Mexico are at high risk for malnutrition and marginalization. The study compared secular changes in the growth status of urban and rural schoolchildren in the Valley of Oaxaca between the 1970s and 2000. Cross-sectional surveys of boys and girls aged 6-13 years (n = 1472) were carried out in an urban colonia populares in 1972 and 2000 and a rural indigenous community in 1978 and 2000. Height, sitting height and weight were measured; leg length, sitting height ratio, BMI, and prevalence of stunting, underweight, overweight and obesity were calculated. Sex-specific ANCOVA controlling for age was used. Both urban and rural children experienced significant secular gains in linear dimensions, body weight and the BMI between the 1970s and 2000. Estimated rates of secular gain overlapped considerably between urban and rural children. Secular gains in the BMI are significantly greater in urban than rural boys and girls. Urban-rural differences in linear dimensions and body weight in 2000 compared to the 1970s do not differ in either sex, but urban-rural differences in the BMI are greater in boys and girls in 2000 compared to the 1970s. The prevalence of stunting declined while that of overweight and obesity increased. Significant secular increases in body size occurred between the 1970s and 2000, but there was considerable overlap between urban and rural children. Only secular gains in the BMI were significantly greater in urban than rural boys and girls and the magnitudes of urban-rural differences in the BMI were greater in 2000 than in the 1970s.

Secular and Religious Social Support Better Protect Blacks than Whites against Depressive Symptoms.

PubMed

Assari, Shervin; Moghani Lankarani, Maryam

2018-05-04

Purpose: Although the protective effect of social support against depression is well known, limited information exists on racial differences in this association. The current study examined Black-White differences in the effects of religious and secular emotional social support on depressive symptoms in a national sample of older adults in the United States. Methods: With a longitudinal prospective design, the Religion, Aging and Health Survey, 2001⁻2004, followed 1493 Black ( n = 734) and White ( n = 759) elderly individuals (age 66 and older) for three years. Race, demographics (age and gender), socio-economics (education and marital status) and frequency of church attendance were measured at baseline in 2001. Secular social support, religious social support, chronic medical conditions and depressive symptoms [8- item Center for Epidemiological Studies-Depression scale (CES-D)] were measured in 2004. Multiple linear regression models were used for data analysis. In the pooled sample, secular and religious social support were both protective against depressive symptoms, net of all covariates. Race interacted with secular ( β = −0.62 for interaction) and religious ( β = −0.21 for interaction) social support on baseline depressive symptoms ( p < 0.05 for both interactions), suggesting larger protections for Blacks compared to Whites. In race-specific models, the regression weight for the effect of secular social support on depressive symptoms was larger for Blacks ( β = −0.64) than Whites ( β = −0.16). Conclusion: We found Black—White differences in the protective effects of secular and religious social support against depressive symptoms. Blacks seem to benefit more from the same level of emotional social support, regardless of its source, compared to Whites.

Secular and Religious Social Support Better Protect Blacks than Whites against Depressive Symptoms

PubMed Central

Moghani Lankarani, Maryam

2018-01-01

Purpose: Although the protective effect of social support against depression is well known, limited information exists on racial differences in this association. The current study examined Black-White differences in the effects of religious and secular emotional social support on depressive symptoms in a national sample of older adults in the United States. Methods: With a longitudinal prospective design, the Religion, Aging and Health Survey, 2001–2004, followed 1493 Black (n = 734) and White (n = 759) elderly individuals (age 66 and older) for three years. Race, demographics (age and gender), socio-economics (education and marital status) and frequency of church attendance were measured at baseline in 2001. Secular social support, religious social support, chronic medical conditions and depressive symptoms [8- item Center for Epidemiological Studies-Depression scale (CES-D)] were measured in 2004. Multiple linear regression models were used for data analysis. Results: In the pooled sample, secular and religious social support were both protective against depressive symptoms, net of all covariates. Race interacted with secular (β = −0.62 for interaction) and religious (β = −0.21 for interaction) social support on baseline depressive symptoms (p < 0.05 for both interactions), suggesting larger protections for Blacks compared to Whites. In race-specific models, the regression weight for the effect of secular social support on depressive symptoms was larger for Blacks (β = −0.64) than Whites (β = −0.16). Conclusion: We found Black—White differences in the protective effects of secular and religious social support against depressive symptoms. Blacks seem to benefit more from the same level of emotional social support, regardless of its source, compared to Whites. PMID:29734662

A model for solar constant secular changes

NASA Technical Reports Server (NTRS)

Schatten, Kenneth H.

1988-01-01

In this paper, contrast models for solar active region and global photospheric features are used to reproduce the observed Active Cavity Radiometer and Earth Radiation Budget secular trends in reasonably good fashion. A prediction for the next decade of solar constant variations is made using the model. Secular trends in the solar constant obtained from the present model support the view that the Maunder Minimum may be related to the Little Ice Age of the 17th century.

Talking ethics with strangers: a view from Jewish tradition.

PubMed

Newman, L E

1993-12-01

The work of H. Tristram Engelhardt provides an important set of reflections for bioethics in a secular context. Taking Engelhardt's work as its point of departure this article explores the challenges that Jewish ethicists face in contributing to bioethics in a secular context. The article explores how the Jewish tradition can address issues in bioethics in ways that are true to its tradition and at the same time accessible and relevant to "moral strangers" in a secular society.

Modelling the secular evolution of migrating planet pairs

NASA Astrophysics Data System (ADS)

Michtchenko, T. A.; Rodríguez, A.

2011-08-01

The subject of this paper is the secular behaviour of a pair of planets evolving under dissipative forces. In particular, we investigate the case when dissipative forces affect the planetary semimajor axes and the planets move inwards/outwards the central star, in a process known as planet migration. To perform this investigation, we introduce fundamental concepts of conservative and dissipative dynamics of the three-body problem. Based on these concepts, we develop a qualitative model of the secular evolution of the migrating planetary pair. Our approach is based on the analysis of the energy and the orbital angular momentum exchange between the two-planet system and an external medium; thus no specific kind of dissipative forces is invoked. We show that, under the assumption that dissipation is weak and slow, the evolutionary routes of the migrating planets are traced by the Mode I and Mode II stationary solutions of the conservative secular problem. The ultimate convergence and the evolution of the system along one of these secular modes of motion are determined uniquely by the condition that the dissipation rate is sufficiently smaller than the proper secular frequency of the system. We show that it is possible to reassemble the starting configurations and the migration history of the systems on the basis of their final states and consequently to constrain the parameters of the physical processes involved.

Striking Seasonality in the Secular Warming of the Northern Continents: Structure and Mechanisms

NASA Astrophysics Data System (ADS)

Nigam, S.; Thomas, N. P.

2017-12-01

The linear trend in twentieth-century surface air temperature (SAT)—a key secular warming signal— exhibits striking seasonal variations over Northern Hemisphere continents; SAT trends are pronounced in winter and spring but notably weaker in summer and fall. The SAT trends in historical twentieth-century climate simulations informing the Intergovernmental Panel for Climate Change's Fifth Assessment show varied (and often unrealistic) strength and structure, and markedly weaker seasonal variation. The large intra-ensemble spread of winter SAT trends in some historical simulations was surprising, especially in the context of century-long linear trends, with implications for the detection of the secular warming signal. The striking seasonality of observed secular warming over northern continents warrants an explanation and the representation of related processes in climate models. Here, the seasonality of SAT trends over North America is shown to result from land surface-hydroclimate interactions and, to an extent, also from the secular change in low-level atmospheric circulation and related thermal advection. It is argued that the winter dormancy and summer vigor of the hydrologic cycle over middle- to high-latitude continents permit different responses to the additional incident radiative energy from increasing greenhouse gas concentrations. The seasonal cycle of climate, despite its monotony, provides an expanded phase space for the exposition of the dynamical and thermodynamical processes generating secular warming, and an exceptional cost-effective opportunity for benchmarking climate projection models.

Pilot trials with a fluorescent whitening agent of the bis(triazoly) stilbene-disulfonic acid type in golden orfes.

PubMed

Hamburger, B; Maul, W; Patzschke, K; Theidel, H; Wegner, L A

1975-01-01

Golden orfes were examined for uptake, distribution, and elimination of radioactivity administered in the form of a 14C-labelled fluorescent whitening agent (FWA) of the bis(triazolyl)stilbenedisulfonic acid type. Results of these studies are given below. Pilot trials using FWA concentrations of 10 and 100 ppb and a population density of 1 fish per liter show that an equilibrium between uptake and elimination of the FWA develops in the animals within a period of one week; i.e., the incorporated traces of the FWA are not irreversibly bound. The radioactivity is mainly located in the gall bladder and in the intestinal contents, as well as in the liver, throat, and gills. The muscular system (filet) is virtually free from activity. Approximately 1-2% of the FWA amount administered per animal (corresponding to the concentration factors of 7-14) can be temporarily detected in the fish. Radioactivity is eliminated comparatively quickly. Two days following the transfer of the fish into water free from FWA a concentration factor as low as 1 is reached, i.e. from this time the FWA concentration in the animals decreases to less than 10 resp. 100 ppb.

Religious and Secular Coping and Family Relationships in the Neonatal Intensive Care Unit

PubMed Central

Brelsford, Gina M.; Ramirez, Joshua; Veneman, Kristin; Doheny, Kim K.

2017-01-01

Background Preterm birth is an unanticipated and stressful event for parents. In addition, the unfamiliar setting of the intensive care nursery necessitates strategies for coping. Purpose The primary study objective of this descriptive study was to determine whether secular and religious coping strategies were related to family functioning in the neonatal intensive care unit. Methods Fifty-two parents of preterm (25–35 weeks’ gestation) infants completed the Brief COPE (secular coping), the Brief RCOPE (religious coping), and the Family Environment Scale within 1 week of their infant’s hospital admission. Findings This descriptive study found that parents’ religious and secular coping was significant in relation to family relationship functioning. Specifically, negative religious coping (ie, feeling abandoned or angry at God) was related to poorer family cohesion and use of denial. Implications for Practice These findings have relevance for interventions focused toward enhancing effective coping for families. Implications for Research Further study of religious and secular coping strategies for neonatal intensive care unit families is warranted in a larger more diverse sample of family members. PMID:27391569

The Progress of Physics

NASA Astrophysics Data System (ADS)

Schuster, Arthur

2015-10-01

Introduction; 1. Scope of lectures. State of physics in 1875. Science of energy. Theory of gases. Elastic solid theory of light. Maxwell's theory of electricity. Training of students. Maxwell's view. Accurate measurement and discovery of Argon. German methods. Kirchhoff's laboratory. Wilhelm Weber's laboratory. The two laboratories of Berlin. Laboratory instruction at Manchester. Position of physics in mathematical tripos at Cambridge. Todhunter's views. The Cavendish laboratory. Spectrum analysis. The radiometer. Theory of vortex atom; 2. Action at a distance. Elastic solid of theory of light. Maxwell's theory of electrical action. Electro-magnetic theory. Verification of electromagnetic theory by Hertz. Electro-magnetic waves. Wireless telegraphy. First suggestion of molecular structure of electricity. Early experiments in the electric discharge through gases. Kathode rays. Works of Goldstein and Crookes. Hittorf's investigations. Own work on the discharge through gases. Ionization of gases. Magnetic deflexion of kathode rays. J. J. Thomson's experiments. Measurement of atomic charge; 3. Roentgen's discovery. Theories of Roentgen rays. Ionizing power of Roentgen rays. Conduction of electricity through ionized gases. Discovery of radio-activity. Discovery of radium. Magnetic deflexion of rays emitted by radio-active bodies. Discovery of emanations. Theory of radio-active change. Decay of the atom. Connexion between helium and the a ray. Helium produced by radium. Strutt's researches on helium accumulated in rocks. Electric inertia. Constitution of atom. J. J. Thomson's theory of Roentgen radiation. The Michelson-Morley experiment. Principle of relativity. The Zeeman effect. Other consequences of electron theory. Contrast between old and modern school of physics; 4. Observational sciences. Judgment affected by scale. Terrestrial magnetism. Existence of potential. Separation of internal and external causes. Diurnal variation. Magnetic storms. Their causes. Solar influence. Theories of secular variation. Atmospheric electricity. Negative charge of Earth. Ionization of air. Origin of atmospheric electricity. Electric charge of rain. Ebert's theory. Cause of thunderstorms. The age of the Earth. Rigidity of Earth. Displacement of axis. Gravitation. Identity of molecules of the same kind; Index.

Secular evolution of asteroid families: the role of Ceres

NASA Astrophysics Data System (ADS)

Novaković, Bojan; Tsirvoulis, Georgios; Marò, Stefano; Đošović, Vladimir; Maurel, Clara

2016-01-01

We consider the role of the dwarf planet Ceres on the secular dynamics of the asteroid main belt. Specifically, we examine the post impact evolution of asteroid families due to the interaction of their members with the linear nodal secular resonance with Ceres. First, we find the location of this resonance and identify which asteroid families are crossed by its path. Next, we summarize our results for three asteroid families, namely (1726) Hoffmeister, (1128) Astrid and (1521) Seinajoki which have irregular distributions of their members in the proper elements space, indicative of the effect of the resonance. We confirm this by performing a set of numerical simulations, showcasing that the perturbing action of Ceres through its linear nodal secular resonance is essential to reproduce the actual shape of the families.

Advancing Performance Assessment for Disposal of Depleted Uranium at Clive Utah - 12493

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

Black, Paul; Tauxe, John; Perona, Ralph

2012-07-01

A Performance Assessment (PA) for disposal of depleted uranium (DU) waste has recently been completed for a potential disposal facility at Clive in northwestern Utah. For the purposes of this PA, 'DU waste' includes uranium oxides of all naturally-occurring isotopes, though depleted in U-235, varying quantities of other radionuclides introduced to the uranium enrichment process in the form of used nuclear reactor fuel (reactor returns), and decay products of all of these radionuclides. The PA will be used by the State of Utah to inform an approval decision for disposal of DU waste at the facility, and will be availablemore » to federal regulators as they revisit rulemaking for the disposal of DU. The specific performance objectives of the Clive DU PA relate to annual individual radiation dose within a 10,000-year performance period, groundwater concentrations of specific radionuclides within a 500-year compliance period, and site stability in the longer term. Fate and transport processes that underlie the PA model include radioactive decay and ingrowth, diffusion in gaseous and water phases, water advection in unsaturated and saturated zones, transport caused by plant and animal activity, cover naturalization, natural and anthropogenic erosion, and air dispersion. Fate and transport models were used to support the dose assessment and the evaluation of groundwater concentrations. Exposure assessment was based on site-specific scenarios, since the traditional human exposure scenarios suggested by DOE and NRC guidance are unrealistic for this site. Because the U-238 in DU waste reaches peak radioactivity (secular equilibrium) after 2 million years (My) following its separation, the PA must also evaluate the impact of climate change cycles, including the return of pluvial lakes such as Lake Bonneville. The first draft of the PA has been submitted to the State of Utah for review. The results of this preliminary analysis indicate that doses are very low for the site-specific receptors for the 10,000-year compliance period. This is primarily because DU waste is not highly radioactive within this time frame, the DU waste is assumed to be buried beneath zones exposed by erosion, groundwater concentrations of DU waste constituents do not exceed groundwater protection limits with in the 500-year compliance period, and the first deep lake occurrence will disperse DU waste across a large area, and will ultimately be covered by lake-derived sediment. A probabilistic PA model was constructed that considered DU waste and decay product doses to site-specific receptors for a 10,000-yr performance period, as well as deep-time effects. The quantitative results are summarized in Table VII. Doses (as TEDE) are always less than 5 mSv in a year, and doses to the offsite receptors are always much less than 0.25 mSv in a year. Groundwater concentrations of Tc-99 are always less than its GWPL except when the Tc-99 contaminated waste is disposed below grade. Even in this case, the median groundwater concentration is only 4.18 Bq/L (113 pCi/L), which is more than one order of magnitude less than the GWPL for Tc-99. The results overall suggest that there are disposal configurations that can be used to dispose of the proposed quantities of DU waste that are adequately protective of human health. (authors)« less

Ethics of surrogacy: a comparative study of Western secular and islamic bioethics.

PubMed

Islam, Sharmin; Nordin, Rusli Bin; Bin Shamsuddin, Ab Rani; Mohd Nor, Hanapi Bin; Al-Mahmood, Abu Kholdun

2012-01-01

The comparative approach regarding the ethics of surrogacy from the Western secular and Islamic bioethical view reveals both commensurable and incommensurable relationship. Both are eager to achieve the welfare of the mother, child and society as a whole but the approaches are not always the same. Islamic bioethics is straightforward in prohibiting surrogacy by highlighting the lineage problem and also other social chaos and anarchy. Western secular bioethics is relative and mostly follows a utilitarian approach.

The Importance of Turkish and US Relations: Contributing for Joint Objectives of a Secure Middle East

DTIC Science & Technology

2017-03-31

As a Muslim-majority country that is transitioning from being a secular democratic state toward its Islamic roots, a member of NATO, and a long...being a secular democratic state toward its Islamic roots, a member of NATO, and a long-standing US ally, Turkey is pivotal to the US strategy to shape...productive country needed education, so Kemal advocated a unified school system with secular, Turkish language schools.2 Under Mustafa Kemal’s leadership

Ethics of Surrogacy: A Comparative Study of Western Secular and Islamic Bioethics

PubMed Central

Islam, Sharmin; Nordin, Rusli Bin; Bin Shamsuddin, Ab Rani; Mohd Nor, Hanapi Bin; Al-Mahmood, Abu Kholdun

2012-01-01

The comparative approach regarding the ethics of surrogacy from the Western secular and Islamic bioethical view reveals both commensurable and incommensurable relationship. Both are eager to achieve the welfare of the mother, child and society as a whole but the approaches are not always the same. Islamic bioethics is straightforward in prohibiting surrogacy by highlighting the lineage problem and also other social chaos and anarchy. Western secular bioethics is relative and mostly follows a utilitarian approach. PMID:23864994

Time to Exorcise Another Ghost From the Vietnam War: Restructuring the In-Service Conscientious Objector Program

DTIC Science & Technology

1993-04-01

rely on Lemon v . Kurtzman , 403 U.S. 602 (1971), in its analysis even though Lemon previously had been the most commonly applied analytical approach to...U.S. 203, (1963) (applying a secular purpose and principle effects test to measure neutrality); Lemon v . Kurtzman , 403 U.S. 602 (1971) (applying a...from Lemon along with measuring secular symbols as impacting determination of secular purpose and principle effect); Lee v . Weisman, 112 S. Ct. 2649

Quantification of metabotropic glutamate subtype 5 receptors in the brain by an equilibrium method using 18F-SP203.

PubMed

Kimura, Yasuyuki; Siméon, Fabrice G; Zoghbi, Sami S; Zhang, Yi; Hatazawa, Jun; Pike, Victor W; Innis, Robert B; Fujita, Masahiro

2012-02-01

A new PET ligand, 3-fluoro-5-(2-(2-(18)F-(fluoromethyl)-thiazol-4-yl)ethynyl)benzonitrile (18F-SP203) can quantify metabotropic glutamate subtype 5 receptors (mGluR5) in human brain by a bolus injection and kinetic modeling. As an alternative approach to a bolus injection, binding can simply be measured as a ratio of tissue to metabolite-corrected plasma at a single time point under equilibrium conditions achieved by administering the radioligand with a bolus injection followed by a constant infusion. The purpose of this study was to validate the equilibrium method as an alternative to the standard kinetic method for measuring 18F-SP203 binding in the brain. Nine healthy subjects were injected with 18F-SP203 using a bolus plus constant infusion for 300 min. A single ratio of bolus-to-constant infusion (the activity of bolus equaled to that of infusion over 219 min) was applied to all subjects to achieve equilibrium in approximately 120 min. As a measure of ligand binding, we compared total distribution volume (VT) calculated by the equilibrium and kinetic methods in each scan. The equilibrium method calculated VT by the ratio of radioactivity in the brain to the concentration of 18F-SP203 in arterial plasma at 120 min, and the kinetic method calculated VT by a two-tissue compartment model using brain and plasma dynamic data from 0 to 120 min. VT obtained via the equilibrium method was highly correlated with VT obtained via kinetic modeling. Inter-subject variability of VT obtained via the equilibrium method was slightly smaller than VT obtained via the kinetic method. VT obtained via the equilibrium method was ~10% higher than VT obtained via the kinetic method, indicating a small difference between the measurements. Taken together, the results of this study show that using the equilibrium method is an acceptable alternative to the standard kinetic method when using 18F-SP203 to measure mGluR5. Although small differences in the measurements obtained via the equilibrium and kinetic methods exist, both methods consistently measured mGluR5 as indicated by the highly correlated VT values; the equilibrium method was slightly more precise, as indirectly measured by the smaller coefficient of variability across subjects. In addition, when using 18F-SP203, the equilibrium method is more efficient because it requires much less data. Copyright © 2011. Published by Elsevier Inc.

Preliminary study on removing Cs⁺/Sr²⁺ by activated porous calcium silicate-A by-product from high-alumina fly ash recycling industry.

PubMed

Chu, Yingying; Wang, Rong; Chen, Mengjun

2015-01-01

¹³⁷Cs⁺/⁹⁰Sr²⁺-containing radioactive wastewater is one of the most important problems that the world has been facing with. A by-product, activated porous calcium silicate, is generated at high levels by the pre-desiliconizing and soda-lime-sintering processes for producing Al₂O₃from high-alumina fly ash. In order to examine if this by-product could be used as an absorbent for removal of ¹³⁷Cs⁺/⁹⁰Sr²⁺ from radioactive wastewater, various parameters, such as pH, adsorbent dose, contact time, and initial concentration, were discussed. Results indicated that the equilibrium reached in about 2 hr. Activated porous calcium silicate was highly pH sensitive and able to remove Cs(+)/Sr²⁺ in a near-neutral environment. The adsorption equilibrium was best described by Freundlich isotherm equations, and the adsorption of Cs⁺/Sr²⁺ was a physical process. The adsorption kinetic data could be better fitted by the pseudo-second-order model, and the adsorption was controlled by multidiffusion. Current study showed that activated porous calcium silicate has a good adsorption of Cs⁺/Sr²⁺ for their removal. However, other characteristics, such as selectivity because of coexisting cations, elution and regeneration, thermal stability, and acid resistance, should be discussed carefully before using it in an actual field.

Polyacrylamide-hydroxyapatite composite: Preparation, characterization and adsorptive features for uranium and thorium

NASA Astrophysics Data System (ADS)

Baybaş, Demet; Ulusoy, Ulvi

2012-10-01

The composite of synthetically produced hydroxyapatite (HAP) and polyacrylamide was prepared (PAAm-HAP) and characterized by BET, FT-IR, TGA, XRD, SEM and PZC analysis. The adsorptive features of HAP and PAAm-HAP were compared for UO22+ and Th4+. The entrapment of HAP into PAAm-HAP did not change the structure of HAP. Both structures had high affinity to the studied ions. The adsorption capacity of PAAm-HAP was than that of HAP. The adsorption dependence on pH and ionic intensity provided supportive evidences for the effect of complex formation on adsorption process. The adsorption kinetics was well compatible to pseudo second order model. The values of enthalpy and entropy changes were positive. Th4+ adsorption from the leachate obtained from a regional fluorite rock confirmed the selectivity of PAAm-HAP for this ion. In consequence, PAAm-HAP should be considered amongst favorite adsorbents for especially deposition of nuclear waste containing U and Th, and radionuclide at secular equilibrium with these elements.

AMS Measurement of 36Cl with a Q3D Magnetic Spectrometer at CIAE

NASA Astrophysics Data System (ADS)

Li, Chaoli; He, Ming; Zhang, Wei; Wu, Shaoyong; Li, Zhenyu; He, Xianwen; Liu, Jiancheng; Dong, Kejun; Jiang, Shan

2012-06-01

The ratio of 36Cl/Cl can determine the exposure age of surface rocks and monitor the secular equilibrium of 36Cl of sedimentary and igneous rock in groundwater. Due to the uncertainty effects of different chemical separation processes for removing 36S, there is a high degree of uncertainty in 36Cl accelerator mass spectrometry (AMS) measurements if the ratio of 36Cl/Cl is lower than 10-14. A 36Cl AMS higher sensitivity measurement has been set up by using a ΔE-Q3D method at the China Institute of Atomic Energy (CIAE). The performances of ΔE-Q3D method for 36Cl-AMS measurement had been systemically studied. The experimental results show that the ΔE-Q3D method has a higher isobar suppression factor. Taking advantage of direct removing 36S, the sample preparation can be simplified and the uncertainty effects of different chemical separation processes can be reduced in 36Cl AMS measurements.

Modelling the behaviour of uranium-series radionuclides in soils and plants taking into account seasonal variations in soil hydrology.

PubMed

Pérez-Sánchez, D; Thorne, M C

2014-05-01

In a previous paper, a mathematical model for the behaviour of (79)Se in soils and plants was described. Subsequently, a review has been published relating to the behaviour of (238)U-series radionuclides in soils and plants. Here, we bring together those two strands of work to describe a new mathematical model of the behaviour of (238)U-series radionuclides entering soils in solution and their uptake by plants. Initial studies with the model that are reported here demonstrate that it is a powerful tool for exploring the behaviour of this decay chain or subcomponents of it in soil-plant systems under different hydrological regimes. In particular, it permits studies of the degree to which secular equilibrium assumptions are appropriate when modelling this decay chain. Further studies will be undertaken and reported separately examining sensitivities of model results to input parameter values and also applying the model to sites contaminated with (238)U-series radionuclides. Copyright © 2013 Elsevier Ltd. All rights reserved.

Environmental assessment of gamma-radiation levels in stream sediments around Sharm El-Sheikh, South Sinai, Egypt.

PubMed

Al-Sharkawy, A; Hiekal, M Th; Sherif, M I; Badran, H M

2012-10-01

A total surface area of ∼170 km(2) including 28 localities around Sharm El-Sheikh, South Sinai, were investigated by γ-ray spectroscopy. The concentrations of NORM were found to be five to seven-fold that in dune sands in different regions in Sinai. While relatively higher levels of (238)U, (234)Th, (226)Ra, and (232)Th are associated with the existing monzo-syenogranite, the concentration of (40)K is more uniformly distributed in the studied area. Locations with higher concentrations of (137)Cs are mainly located in the northern part. The (238)U, (234)Th and (226)Ra isotopes in the (238)U-series are in secular equilibrium. The absorbed dose rates and gamma-radiation hazard indices in all locations were higher than the world average value and unity, respectively. Properly regulated land use is recommended for a buffer zone in the northern part of the study area. Copyright © 2012 Elsevier Ltd. All rights reserved.

Ecological Dose Modeling of Aquatic and Riparian Receptors to Strontium-90 with an Emphasis on Radiosensitive Organs

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

Poston, Ted M.; Traub, Richard J.; Antonio, Ernest J.

2011-07-20

The 100-NR-2 site is the location of elevated releases of strontium-90 to the Columbia River via contaminated groundwater. The resulting dose to aquatic and riparian receptors was evaluated in 2005 (DOE 2009) and compared to U.S. Department of Energy (DOE) dose guidance values. We have conducted additional dose assessments for a broader spectrum of aquatic and riparian organisms using RESRAD Biota and specific exposure scenarios. Because strontium-90 accumulates in bone, we have also modeled the dose to the anterior kidney, a blood-forming and immune system organ that lies close to the spinal column of fish. The resulting dose is primarilymore » attributable to the yttrium-90 progeny of strontium-90 and very little of the dose is associated with the beta emission from strontium-90. All dose modeling results were calculated with an assumption of secular equilibrium between strontium-90 and yttrum-90.« less

The ratio of lead-210 to polonium-210 in U.K. diet.

PubMed

Smith-Briggs, J L; Bradley, E J; Potter, M D

1986-10-01

The levels of the natural radionuclides, 210Pb and 210Po, in U.K. diet have been measured previously. However, in the earlier measurements, the samples were sufficiently aged for 210Pb and 210Po to have attained secular equilibrium. In order to determine the extent of disequilibrium between these radionuclides in fresh food, measurements have been made on recently collected dietary samples. Disequilibrium has been observed in five food groups. The activity per unit mass of 210Pb was found to be greater than that of 210Po in bread, cereals, sugar and preserves, whereas the opposite was found to be true for eggs and beverages. When account is taken of consumption rates, however, the total intakes of 210Pb and 210Po from these food groups are approximately the same. The annual effective dose equivalents from the ingestion of 210Pb and 210Po have been re-estimated at 41 and 12 mu Sv, respectively.

Secular resonances with massive asteroids and their impact on the dynamics of small bodies

NASA Astrophysics Data System (ADS)

Tsirvoulis, Georgios; Novaković, Bojan; Djošović, Valdimir

2015-08-01

The quest for understanding the dynamical structure of the main belt has been a long-lasting endeavor. From the discovery of the Kirkwood gaps and the Hirayama families, to the more recent advances in secular perturbation theory, the refinement of the proper elements and the discovery of the three-body mean-motion resonances, only to name a few, the progress has been immense. Dynamical models coupled with the outbursts in computational power and observations have greatly improved our knowledge of the dynamical evolution of the small bodies in the Solar System.While our set of tools for studying the dynamical porperties of the main belt is believed to be sufficiently complete, our assumptions on how to use them seem to have hindered this effort.The concensus has been that, judging by their mass, only the planets, especially the giant ones, can act as efficient perturbers of the orbits of asteroids. Thus a lot of studies have been made on the locations and effects of secular resonances with the giant planets in different parts of the main belt, explaining among other things the presence of gaps in the distribution of asteroids, strange shapes of some asteroid families and transport mechanisms of asteroids to the near-Earth region.Our work is motivated by the first discovery that a secular resonance with the most massive asteroid, Ceres, is the dominant dynamical mechanism responsible for the post-impact evolution of the Hoffmeister family members. Thus the concensus is wrong. Knowing now, that secular resonances with massive asteroids can be effective on asteroid dynamics, we set out to construct a dynamical map of these resonances across the main belt.Our study is focused on the linear and degree four non-linear secular resonances with the two most massive asteroids (1) Ceres and (4) Vesta. First we determine the locations of these secular resonances in the proper elements space, acquiring an understanding of the potentially affected regions, and then we perform numerical simulations to investigate the importance of each secular resonance on the dynamical evolution of asteroid orbits in the different parts of the main belt.

Importance of selecting archaeomagnetic data for geomagnetic modelling: example of the new Western Europe directional and intensity secular variation curves from 1500 BC to 200 AD

NASA Astrophysics Data System (ADS)

Herve, Gwenael; Chauvin, Annick; Lanos, Philippe

2014-05-01

At the regional scale, the dispersion between archaeomagnetic data and especially archaeointensities suggests that some of them may be biased. As a consequence, it appears necessary to perform a selection of available data before to compute mean regional secular variation curves or geomagnetic models. However the definition of suitable selection criteria is not obvious and we need to know how to manage "old" data acquired during the 60-70s. The Western Europe directional and intensity data set from 1500 BC to 200 AD allows to discuss these issues. It has recently been enhanced by 39 new archaeodirections and 23 new archaeointensities (Hervé et al., 2013a and 2013b data sets and 5 unpublished data). First, the whole Western Europe data set was selected but the strong dispersion restricted the accuracy and the reliability of the new Western Europe secular variation curves at Paris. The causes of the dispersion appear different between archaeodirections and archaeointensities. In the directional data set, the main problem comes from some age errors in the oldest published data. Since their publication their archaeological dating may have changed of 50 years or more. For intensity data that were acquired much more recently, the dispersion mainly results from the use of unreliable archaeointensity protocols. We propose a weighting approach based on the number of specimens and the use of pTRM-checks, anisotropy and cooling rate corrections. Only 63% of available archaeodirections and 32% of archaeointensities were used to build the new Western Europe secular variation curves from 1500 BC to 200 AD. These curves reveal that selecting the reference data avoids wrong estimations of the shape of the secular variation curves, the secular variation rate, the dating of archaeomagnetic jerks... Finally, it is worth pointing out that current geomagnetic global models take into account almost all the data that we decided to reject. It could partly explain why their predictions at Paris do not fit our local secular variation curves. Hervé, G., Chauvin, A. & Lanos, P., 2013a. Geomagnetic field variations in Western Europe from 1500BC to 200AD. Part I : Directional secular variation curve, Phys. Earth Planet. Inter., 218, 1-13. Hervé, G., Chauvin, A. & Lanos, P., 2013b. Geomagnetic field variations in Western Europe from 1500BC to 200AD. Part II : New intensity secular variation curve, Phys. Earth Planet. Inter., 218, 51-65.

Towards the Implementation of Semi-Dynamic Datum for Malaysia

NASA Astrophysics Data System (ADS)

Shariff, N. S.; Gill, J.; Amin, Z. M.; Omar, K. M.

2017-10-01

A semi-dynamic datum provides positions with respect to time while taking into account the secular and non-secular deformations, making it the best approach to adapt with the dynamic processes of the earth. Malaysia, as yet, employs a static datum, i.e., GDM2000, at epoch 2000; though Malaysia has evidently been affected by seismic activity for the past decade. Therefore, this paper seeks to propose a design for implementing a semi-dynamic datum for Malaysia. Methodologically, GPS time series analyses are carried out to investigate the seismic activity of Malaysia, which essentially contributes to the proposed design of the semi-dynamic datum for Malaysia. The implications of implementing a semi-dynamic datum for Malaysia are discussed as well. The results indicate that Malaysia undergoes a complex deformation; whereby the earthquakes - primarily the 2004 Sumatra-Andaman, 2005 Nias and 2012 Northern Sumatra earthquakes - have affected the underlying secular velocities of Malaysia. Consequently, from this information, the proposed design, particularly the secular and non-secular deformation models, is described in detail. The proposed semi-dynamic datum comprises a transformation, temporal, and spatial module, and utilizes a bilinear interpolation method. Overall, this paper aims to contribute to the feasibility of a semi-dynamic datum approach for Malaysia.

Advanced evaporator technology progress report FY 1992

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

Chamberlain, D.; Hutter, J.C.; Leonard, R.A.

1995-01-01

This report summarizes the work that was completed in FY 1992 on the program {open_quotes}Technology Development for Concentrating Process Streams.{close_quotes} The purpose of this program is to evaluate and develop evaporator technology for concentrating radioactive waste and product streams such as those generated by the TRUEX process. Concentrating these streams and minimizing the volume of waste generated can significantly reduce disposal costs; however, equipment to concentrate the streams and recycle the decontaminated condensates must be installed. LICON, Inc., is developing an evaporator that shows a great deal of potential for this application. In this report, concepts that need to bemore » incorporated into the design of an evaporator operated in a radioactive environment are discussed. These concepts include criticality safety, remote operation and maintenance, and materials of construction. Both solubility and vapor-liquid equilibrium data are needed to design an effective process for concentrating process streams. Therefore, literature surveys were completed and are summarized in this report. A model that is being developed to predict vapor phase compositions is described. A laboratory-scale evaporator was purchased and installed to study the evaporation process and to collect additional data. This unit is described in detail. Two new LICON evaporators are being designed for installation at Argonne-East in FY 1993 to process low-level radioactive waste generated throughout the laboratory. They will also provide operating data from a full-sized evaporator processing radioactive solutions. Details on these evaporators are included in this report.« less

Localized sudden changes in the geomagnetic secular variation.

USGS Publications Warehouse

Alldredge, L.R.

1987-01-01

There is much debate as to whether there was a worldwide geomagnetic jerk in 1969 or 1970. It is agreed that there was an unusual sharp change in the secular variation in the east component, Y, in Europe at that time. This note points out how a localized sudden change in the secular variation pattern of one component in Europe can occur without having any large worldwide effects in any of the components. The accompanying changes in the spherical harmonic coefficients for such a localized change are also discussed. -after Author

Standardization of 237Np by the CIEMAT/NIST LSC tracer method

PubMed

Gunther

2000-03-01

The standardization of 237Np presents some difficulties: several groups of alpha, beta and gamma radiation, chemical problems with the daughter nuclide 233Pa, an incomplete radioactive equilibrium after sample preparation, high conversion of some gamma transitions. To solve the chemical problems, a sample composition involving the Ultima Gold AB scintillator and a high concentration of HCl is used. Standardization by the CIEMAT/NIST method and by pulse shape discrimination is described. The results agree within 0.1% with those obtained by two other methods.

Monitoring of tritium

DOEpatents

Corbett, James A.; Meacham, Sterling A.

1981-01-01

The fluid from a breeder nuclear reactor, which may be the sodium cooling fluid or the helium reactor-cover-gas, or the helium coolant of a gas-cooled reactor passes over the portion of the enclosure of a gaseous discharge device which is permeable to hydrogen and its isotopes. The tritium diffused into the discharge device is radioactive producing beta rays which ionize the gas (argon) in the discharge device. The tritium is monitored by measuring the ionization current produced when the sodium phase and the gas phase of the hydrogen isotopes within the enclosure are in equilibrium.

Secular Acceleration of Barnard's Star

NASA Astrophysics Data System (ADS)

Bartlett, Jennifer L.; Ianna, P. A.

2009-01-01

Barnard's Star should have significant secular acceleration because it lies close to the Sun and has the highest known proper motion along with a large radial velocity. It will pass within about 1.4 pc in another 9,750 years. Secular changes in proper motion and radial velocity are essentially the Coriolis and centrifugal accelerations, respectively, arising from use of a rotating coordinate system defined by the Sun-star radius vector. Although stellar space velocities measured with respect to the Sun are essentially constant, these perspective effects arise with changing distance and viewing angle. Hipparcos-2 plus Nidever et al. (2002) predict a perspective change in the proper motion of 1.285±0.006 mas yr-2 for Barnard's Star. Recent analysis of 900+ photographic plates between 1968 and 1998 with the 26.25-in (0.67-m) McCormick refractor detected a secular acceleration of 1.25±0.04 mas yr-2, which agrees with the predicted value within the measurement errors. Earlier, Benedict et al. (1999) measured its secular acceleration to be 1.2±0.2 mas yr-2 using 3 years of HST FGS observations. Similarly, a perspective change in radial velocity of 4.50±0.01 m s-1 yr-1 can be predicted for Barnard's Star. Kürster et al. (2003) detected variations in their observations of it that are largely attributable to secular acceleration along the line of sight with some contribution from stellar activity. Although secular acceleration effects have been limited for past studies of stellar motions, they can be significant for observations extending over decades or for high-precision measurements required to detect extrasolar planets. Future studies will need to consider this factor for the nearest stars and for those with large proper motions or radial velocities. NSF grant AST 98-20711; Litton Marine Systems; Peninsula Community Foundation Levinson Fund; UVa Governor's Fellowship, Dean's F&A Fellowship, and Graduate School of Arts and Sciences; and, US Naval Observatory supported this research.

Sandstone: secular trends in lithology in southwestern montana.

PubMed

McLane, M

1972-11-03

Long-term secular trends in the composition and texture of sandstones in southwestern Montana reflect changing provenance and depositional environment, which in turn reflect changing tectonic patterns in the Cordilleran mobile belt just to the west.

Relative secular variations of the geomagnetic field along the Zgorzelec-Wiżajny profile, Poland

NASA Astrophysics Data System (ADS)

Wojas, Anna; Grabowska, Teresa; Mikołajczak, Mateusz

2018-03-01

The paper presents results of the study on relative secular variations of total magnetic intensity (TMI) of the geomagnetic field along the 700 km long profile crossing the area of Poland. Surveys were carried out at annual intervals between 1966 and 2016 (50 measurement series), in 31 survey sites (secular points) separated by about 22 km. The studied profile of the SW-NE direction, called Zgorzelec-Wiżajny (Z-W), crosses large parts of the main tectonic units of Europe, namely the Palaeozoic Platform of Central and Western Europe (PLZ) and the East European Craton (EEC), connected by the Teisseyre-Tornquist Zone (TTZ). Using the original methodology of analysis of measured data, reduced to the values of geomagnetic field recorded at the Central Geophysical Observatory in Belsk, the relative secular variations of TMI with the magnetic anomalies (ΔT) and the terrestrial heat flow density (Q) were graphically presented.

Gender identity, nationalism, and social action among Jewish and Arab women in Israel: redefining the social order?

PubMed

Moore, D

2000-01-01

In the study this article explores, the meaning of gender identity for religious and secular Jewish and Arab women in Israeli society is examined. The study focuses on how Israeli women, rank gender identity, relative to other identities like being Jewish/Arab, being Israeli/Palestinian, religious or secular, of a certain ethnic group, and political identity. It examines the characteristics of gender identity and the attitudes that are associated with it. The analysis shows that the hierarchies of identities are different for religious and secular Jewish and Arab women, and that this is related to having different sociopolitical attitudes (e.g., Women's social and political involvement, social obedience, social influence). Thus, the hierarchy of identities and the sociopolitical attitudes of religious women indicate a more consensual acceptance of the social order than the hierarchy of identities and the sociopolitical attitudes of secular women, especially among Arab women.

Milankovic's "end of the world"

NASA Astrophysics Data System (ADS)

Milicevic, Vlado

2009-07-01

The Milankovic's numerical trajectory of secular changes of pole's rotation has shown that its latest positions in positive infinity can be observed on the North Pole of the Siberian plate. Milankovic with his discovers 'end of the world' or total end of activity in asthenosphere. In other words, he discovers plate tectonics of pole's (convergence, divergence, and transform movement), earthquakes, subduction zones, sea floor spreading, etc. This is not just the end of the atmosphere existence, water or life on the planet, but also a geodynamic, co-mechanic and co-climatological climax. This is the beginning of the ice ages. The pole of rotation, by Milankovic, reaches φ = +49° 34'; λ = +65° 16' for the Northern Hemisphere or φ = -130° 26'; λ = -65° 16' for Southern Hemisphere. Based on this data and according to the pole spreading of lithosphere, it is possible to recognize future climatic zones under geographical latitudes and longitudes. These are also known as the green zones, the most endangered continental places. The entire Europe and the parts of Asia will be under ice. Studying the continent of North America we can observe only a part of Canada is under ice (up to 60 of geographical longitude). This will happen due to continuous Atlantic sea floor spreading, and also due to the counterclockwise rotation of the North American plate. This will cause the continents to move away from the North Pole. The problem of some time units and numerical secular positions, Milankovic calculated and graphically presented, still stands as one of the greatest planetary enigmas. Their close picture is available through geophysical, geodetic, and mathematical methods, satellites, stations on the Earth's surface and also through practicing new technology. The mentioned "end of the world" does not present the end of the Earth's cosmic phase. It does not correspond to astronomical age determinants and further planetary deviation. Milankovic has experienced and mathematically presented cinematic planetary model of continents. He further included the water areas, atmosphere, and living beings. The Milankovic's "end of the world" is just an end of the pole's tectonics, critical temperatures and fluidly fall in the atmosphere. Also, it is the ending of the seismic phase, rift genesis, subdaction, and radioactivity. However, all together will not have any further consequences on the other structures, especially not on the Earth's nucleus. The Milankovic's end of the world resembles the minimization of mechanical secular changes of the pole rotation. The Earth's rotation itself stays unchanged or barely changed.

Reference frame access under the effects of great earthquakes: a least squares collocation approach for non-secular post-seismic evolution

NASA Astrophysics Data System (ADS)

Gómez, D. D.; Piñón, D. A.; Smalley, R.; Bevis, M.; Cimbaro, S. R.; Lenzano, L. E.; Barón, J.

2016-03-01

The 2010, (Mw 8.8) Maule, Chile, earthquake produced large co-seismic displacements and non-secular, post-seismic deformation, within latitudes 28°S-40°S extending from the Pacific to the Atlantic oceans. Although these effects are easily resolvable by fitting geodetic extended trajectory models (ETM) to continuous GPS (CGPS) time series, the co- and post-seismic deformation cannot be determined at locations without CGPS (e.g., on passive geodetic benchmarks). To estimate the trajectories of passive geodetic benchmarks, we used CGPS time series to fit an ETM that includes the secular South American plate motion and plate boundary deformation, the co-seismic discontinuity, and the non-secular, logarithmic post-seismic transient produced by the earthquake in the Posiciones Geodésicas Argentinas 2007 (POSGAR07) reference frame (RF). We then used least squares collocation (LSC) to model both the background secular inter-seismic and the non-secular post-seismic components of the ETM at the locations without CGPS. We tested the LSC modeled trajectories using campaign and CGPS data that was not used to generate the model and found standard deviations (95 % confidence level) for position estimates for the north and east components of 3.8 and 5.5 mm, respectively, indicating that the model predicts the post-seismic deformation field very well. Finally, we added the co-seismic displacement field, estimated using an elastic finite element model. The final, trajectory model allows accessing the POSGAR07 RF using post-Maule earthquake coordinates within 5 cm for ˜ 91 % of the passive test benchmarks.

The Dynamics of Tightly-packed Planetary Systems in the Presence of an Outer Planet: Case Studies Using Kepler-11 and Kepler-90

NASA Astrophysics Data System (ADS)

Granados Contreras, A. P.; Boley, A. C.

2018-03-01

We explore the effects of an undetected outer giant planet on the dynamics, observability, and stability of Systems with Tightly-packed Inner Planets (STIPs). We use direct numerical simulations along with secular theory and synthetic secular frequency spectra to analyze how analogues of Kepler-11 and Kepler-90 behave in the presence of a nearly co-planar, Jupiter-like outer perturber with semimajor axes between 1 and 5.2 au. Most locations of the outer perturber do not affect the evolution of the inner planetary systems, apart from altering precession frequencies. However, there are locations at which an outer planet causes system instability due to, in part, secular eccentricity resonances. In Kepler-90, there is a range of orbital distances for which the outer perturber drives planets b and c, through secular interactions, onto orbits with inclinations that are ∼16° away from the rest of the planets. Kepler-90 is stable in this configuration. Such secular resonances can thus affect the observed multiplicity of transiting systems. We also compare the synthetic apsidal and nodal precession frequencies with the secular theory and find some misalignment between principal frequencies, indicative of strong interactions between the planets (consistent with the system showing TTVs). First-order libration angles are calculated to identify MMRs in the systems, for which two near-MMRs are shown in Kepler-90, with a 5:4 between b and c, as well as a 3:2 between g and h.

Secular trends are associated with the demographic and epidemiologic transitions in an indigenous community in Oaxaca, Southern Mexico.

PubMed

Malina, Robert M; Little, Bertis B; Peña Reyes, Maria Eugenia

2018-01-01

To test the hypothesis that secular changes in body size and age at menarche are related to the demographic and epidemiologic transitions in an indigenous community in Oaxaca, southern Mexico. Data were derived from surveys of a Zapotec-speaking community conducted between 1968 and 2000. Segmented linear regressions of height, weight, BMI and recalled age at menarche on year of birth in cohorts of adults born before and after the demographic transition were used to evaluate secular changes. Corresponding comparisons of body size (MANCOVA controlling for age) and age at menarche (status quo, probit analysis) were done for samples of children and adolescents born before and after the epidemiological transition. Height and weight increased in adults born after the demographic transition (mid-1950s), and especially in children and adolescents born after the epidemiological transition (mid-1980s). Age at menarche also decreased significantly in women born after the demographic transition, but at a more rapid estimated rate in adolescents born after the epidemiological transition. Secular gains in body weight were proportional to those for height among children and adolescents, but adults, males more so than females, gained proportionally more weight. The secular trend in height in adults of both sexes was associated with the decade of the demographic transition in the mid-1950s. Significant secular gains in size attained and age at menarche occurred in children and youth born after the epidemiologic transition which likely reflected improved health and nutritional conditions since the mid-1980s. © 2017 Wiley Periodicals, Inc.

Assessing and modeling sediment mobility in estuarine and coastal settings due to extreme climate events from natural short-lived isotope distribution

NASA Astrophysics Data System (ADS)

Ghaleb, Bassam; Hillaire-Marcel, Claude; Ruiz Fernandez, Ana-Carolina; Sanchez Cabeza, Joan-Albert

2016-04-01

Climatic events (e.g. floods, storminess) and management activities (e.g. dredging) may result in the burial or removal and re-suspension of sediments in estuaries and coastal areas. When such sediments are contaminated, such processes may either help restoring better chemical environments or lead to their long-term contamination. Geochemical signatures in surface sediments may help identifying such sedimentological events. However, short-lived isotope data are generally required to set time-constraints on their occurrence. Whereas 210Pb and radioactive fallout isotope contents can help setting time constraints at ~50 to ~100 yr-time scales, natural disequilibria in the 232Th-228Ra-228Th sequence do provide information on processes which occurred within the last 30 yrs, as illustrated in the present study. Box-cored sediments from the Saguenay Fjord and lower estuary of the St. Lawrence (Canada) as well as from estuaries and lagoons from the Sinaloa Coast (Mexico) are used to document the behavior of these isotopes either under relatively steady conditions (St. Lawrence estuary) or under high-frequency extreme climate events (storms and floods; Saguenay Fjord, Coastal Sinaloa). 228Th/232Th activity ratios were determined by chemical extraction of Th and alpha counting of unspiked samples, rapidly after sampling (228Th/232Th). The activity of the intermediate isotope 228Ra was then estimated based on replicate measurements on aliquot samples made a few years later. Under steady conditions, core-top sediment shows an excess in 228Th vs 232Th (AR ~ 1.6), whereas the intermediate 228Ra depicts a deficit vs its parent 232Th (AR ~0.6). Downcore, radioactive decay carries rapidly 228Th-activities to those of the parent 228Ra within about 10 yrs (i.e., ~ 5 half-lives of 228Th), then both move during the next ~20 yrs (~ i.e., ~ 5 half-lives of 228Ra, when added to the 10 yrs of 228Th-excess) towards secular equilibrium with the parent long-lived 232Th. A few algorithms provide simple models governing these processes under relatively high sedimentation rates, i.e., when Ra-diffusion from the sediment towards the water column may be neglected. In sites characterized by extreme sedimentologival events, 228Th/232Th profiles depict departures from this model, thus bearing information on the timing and processes involved. Examples from the Saguenay Fjord (Canada) illustrate the case of fast-deposited layers due to floods, whereas examples from estuaries and coastal areas of Sinaloa show evidence for re-suspension and/or erosion events linked notably to storminess and/or land use changes. In the first case, the fast accumulation of flood layers has sealed most of the early 20th-century contamination, whereas in the second case, erosion and re-suspension events led to either some removal of sediments contaminated by heavy metals, or their secondary release into the environment.

Radioactive Barium Ion Trap Based on Metal-Organic Framework for Efficient and Irreversible Removal of Barium from Nuclear Wastewater.

PubMed

Peng, Yaguang; Huang, Hongliang; Liu, Dahuan; Zhong, Chongli

2016-04-06

Highly efficient and irreversible capture of radioactive barium from aqueous media remains a serious task for nuclear waste disposal and environmental protection. To address this task, here we propose a concept of barium ion trap based on metal-organic framework (MOF) with a strong barium-chelating group (sulfate and sulfonic acid group) in the pore structures of MOFs. The functionalized MOF-based ion traps can remove >90% of the barium within the first 5 min, and the removal efficiency reaches 99% after equilibrium. Remarkably, the sulfate-group-functionalized ion trap demonstrates a high barium uptake capacity of 131.1 mg g(-1), which surpasses most of the reported sorbents and can selectively capture barium from nuclear wastewater, whereas the sulfonic-acid-group-functionalized ion trap exhibits ultrafast kinetics with a kinetic rate constant k2 of 27.77 g mg(-1) min(-1), which is 1-3 orders of magnitude higher than existing sorbents. Both of the two MOF-based ion traps can capture barium irreversibly. Our work proposes a new strategy to design barium adsorbent materials and provides a new perspective for removing radioactive barium and other radionuclides from nuclear wastewater for environment remediation. Besides, the concrete mechanisms of barium-sorbent interactions are also demonstrated in this contribution.

Curriculum Resources.

ERIC Educational Resources Information Center

Thompson, Norma H.

1988-01-01

Discusses an article which presents a concise discussion of secular humanism. Reviews additional materials on censorship from the perspective of the new religious right, the fundamentalists, and public policy and the law. The sources provide background to enhance teaching about secular humanism and textbook censorship. (SLM)

Geomagnetic field models incorporating physical constraints on the secular variation

NASA Technical Reports Server (NTRS)

Constable, Catherine; Parker, Robert L.

1993-01-01

This proposal has been concerned with methods for constructing geomagnetic field models that incorporate physical constraints on the secular variation. The principle goal that has been accomplished is the development of flexible algorithms designed to test whether the frozen flux approximation is adequate to describe the available geomagnetic data and their secular variation throughout this century. These have been applied to geomagnetic data from both the early and middle part of this century and convincingly demonstrate that there is no need to invoke violations of the frozen flux hypothesis in order to satisfy the available geomagnetic data.

Formulas for precession. [motion of mean equator

NASA Technical Reports Server (NTRS)

Kinoshita, H.

1975-01-01

Literal expressions for the precessional motion of the mean equator referred to an arbitrary epoch are constructed. Their numerical representations, based on numerical values recommended at the working meeting of the International Astronomical Union Commission held in Washington in September 1974, are obtained. In constructing the equations of motion, the second-order secular perturbation and the secular perturbation due to the long-periodic terms in the motions of the moon and the sun are taken into account. These perturbations contribute more to the motion of the mean equator than does the term due to the secular perturbation of the orbital eccentricity of the sun.

SECULAR GROWTH AND MATURATION CHANGES IN HUNGARY IN RELATION TO SOCIOECONOMIC AND DEMOGRAPHIC CHANGES.

PubMed

Bodzsar, Eva B; Zsakai, Annamaria; Mascie-Taylor, Nicholas

2016-03-01

This paper analyses the secular changes in the body development patterns of Hungarian children between the 1910s and the beginning of the 2000s in relation to socioeconomic and demographic changes in the country. Individual growth data of children were available from two national growth studies (1983-86, 2003-06), while sample-size weighted means of children's body dimensions were collected through regional studies between the 1920s and 1970s. Gross domestic product, Gini index, life expectancy at birth and under-5 mortality rate were used to assess the changes in economic status, income inequalities of the society and the population's general health status, respectively. Secular changes in food consumption habits were also examined. The positive Hungarian secular changes in socioeconomic status were associated with a continuous increase in children's body dimensions. The negative socioeconomic changes reflected only in wartime and post-war periods of children's growth, and the considerable socioeconomic changes at the beginning of the 1990s did not appear to influence the positive trend in children's growth. The positive secular trend in stature and body mass did not level off at the beginning of the 2000s: the socioeconomic conditions that support optimal growth and maturation could improve in Hungary.

Asteroid Secular Dynamics: Ceres’ Fingerprint Identified

NASA Astrophysics Data System (ADS)

Novaković, Bojan; Maurel, Clara; Tsirvoulis, Georgios; Knežević, Zoran

2015-07-01

Here we report on the significant role of a so far overlooked dynamical aspect, namely, a secular resonance between the dwarf planet Ceres and other asteroids. We demonstrate that this type of secular resonance can be the dominant dynamical factor in certain regions of the main asteroid belt. Specifically, we performed a dynamical analysis of the asteroids belonging to the (1726) Hoffmeister family. To identify which dynamical mechanisms are actually at work in this part of the main asteroid belt, i.e., to isolate the main perturber(s), we study the evolution of this family in time. The study is accomplished using numerical integrations of test particles performed within different dynamical models. The obtained results reveal that the post-impact evolution of the Hoffmeister asteroid family is a direct consequence of the nodal secular resonance with Ceres. This leads us to the conclusion that similar effects must exist in other parts of the asteroid belt. In this respect, the obtained results shed light on an important and entirely new aspect of the long-term dynamics of small bodies. Ceres’ fingerprint in asteroid dynamics, expressed through the discovered secular resonance effect, completely changes our understanding of the way in which perturbations by Ceres-like objects affect the orbits of nearby bodies.

Secular and religious: the intrinsic doubleness of analytical psychology and the hegemony of naturalism in the social sciences.

PubMed

Main, Roderick

2013-06-01

In recent years a number of prominent social theorists, including Jürgen Habermas and Charles Taylor, have voiced concern about the hegemony of naturalistic, secular assumptions in the social sciences, and in their different ways have sought to address this by establishing greater parity between secular and religious perspectives. This paper suggests that C.G. Jung's analytical psychology, which hitherto has been largely ignored by social theory, may have something to contribute on this issue as it can be understood coherently both empirically, without reference to transcendent reality, and metaphysically, with reference to transcendent reality. It is argued that, despite his denials of any metaphysical intent, Jung does in fact engage in metaphysics and that together the empirical and metaphysical vectors of his thought result in a rich and distinctive double perspective. This dual secular and religious perspective can be seen as part of Jung's own critique of the hegemony of naturalism and secularism, which for Jung has profound social as well as clinical relevance. The concern and approach that Habermas and Taylor share with Jung on this issue may provide some grounds for increased dialogue between analytical psychology and the social sciences. © 2013, The Society of Analytical Psychology.

Comment on 'Can infrared gravitons screen {lambda}?'

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

Tsamis, N. C.; Woodard, R. P.; Department of Physics, University of Florida, Gainesville, Florida 32611

2008-07-15

We reply to the recent criticism by Garriga and Tanaka of our proposal that quantum gravitational loop corrections may lead to a secular screening of the effective cosmological constant. Their argument rests upon a renormalization scheme in which the composite operator (R{radical}(-g)-4{lambda}{radical}(-g)){sub ren} is defined to be the trace of the renormalized field equations. Although this is a peculiar prescription, we show that it does not preclude secular screening. Moreover, we show that a constant Ricci scalar does not even classically imply a constant expansion rate. Other important points are: (1) the quantity R{sub ren} of Garriga and Tanaka ismore » neither a properly defined composite operator, nor is it constant; (2) gauge dependence does not render a Green's function devoid of physical content; (3) scalar models on a nondynamical de Sitter background (for which there is no gauge issue) can induce arbitrarily large secular contributions to the stress tensor; (4) the same secular corrections appear in observable quantities in quantum gravity; and (5) the prospects seem good for deriving a simple stochastic formulation of quantum gravity in which the leading secular effects can be summed and for which the expectation values of even complicated, gauge invariant operators can be computed at leading order.« less

Modeling and risk assessment of a 30-Year-old subsurface radioactive-liquid drain field

NASA Astrophysics Data System (ADS)

Dawson, Lon A.; Pohl, Phillip I.

1997-11-01

The contamination from a 30-year-old radioactive liquid drain field was assessed for movement in the subsurface and potential risks to humans. This assessment included determining field concentrations of cesium 137 (137Cs) and other inorganic contaminants and modeling of the flow and transport of the liquid waste that was sent to the drain field. The field investigation detected no contamination deeper than 15 feet (4.6 m) from the bottom of the drain field. Prediction of the water content of the vadose zone showed no saturated conditions for times greater than 10 years after the known infiltration. Sensitivity analysis of the modeling parameters showed the equilibrium sorption coefficient to be the most important factor in predicting the contaminant plumes. Calibration of modeling results with field data gave a 137Cs sorption coefficient that is within the range of values found in the literature. The risk assessment for the site showed that the contamination poses no significant risk to human health.

Copper Ferrocyanide Functionalized Core-Shell Magnetic Silica Composites for the Selective Removal of Cesium Ions from Radioactive Liquid Waste.

PubMed

Lee, Hyun Kyu; Yang, Da Som; Oh, Wonzin; Choi, Sang-June

2016-06-01

The copper ferrocyanide functionalized core-shell magnetic silica composite (mag@silica-CuFC) was prepared and was found to be easily separated from aqueous solutions by using magnetic field. The synthesized mag@silica-CuFC composite has a high sorption ability of Cs owing to its strong affinity for Cs as well as the high surface area of the supports. Cs sorption on the mag@silica-CuFC composite quickly reached the sorption equilibrium after 2 h of contact time. The effect of the presence of salts with a high concentration of up to 3.5 wt% on the efficiency of Cs sorption onto the composites was also studied. The maximum sorption ability was found to be maintained in the presence of up to 3.5 wt% of NaCl in the solution. Considering these results, the mag@silica-CuFC composite has great potential for use as an effective sorbent for the selective removal of radioactive Cs ions.

The Phosphorylation of Ribosomal Protein in Lemna minor

PubMed Central

Trewavas, A.

1973-01-01

Sterile cultures of Lemna minor have been labeled with 32P1, and the ribosomal proteins have been examined for radioactivity. In relatively short term labeling a radioactive protein was found which ran as a single component in both urea/acetic acid and sodium lauryl sulfate gel electrophoresis. Acid hydrolysis of the labeled protein permitted the isolation of serine phosphate. After labeling to equilibrium with 32P1, calculation indicated only 0.6 to 0.75 atom of this protein phosphorus per ribosome. The phosphorylated protein is found in both polysomes and “derived” monomers and appears to be located in the ribosomal small subunit. Its apparent molecular weight is 42,000. Addition of growth-inhibiting concentrations of abscisic acid does not alter the apparent degree of labeling of this protein in 5 hours, but after 24 hours of treatment the total protein phosphorus was reduced from 0.75 atom of phosphorus per ribosome to 0.36 atom of phosphorus per ribosome. PMID:16658405

Predicting Precession Rates from Secular Dynamics for Extra-solar Multi-planet Systems

NASA Astrophysics Data System (ADS)

Van Laerhoven, Christa L.

2015-11-01

Considering the secular dynamics of multi-planet systems provides substantial insight into the interactions between planets in those systems. Secular interactions are those that don't involve knowing where a planet is along its orbit, and they dominate when planets are not involved in mean motion resonances. These interactions exchange angular momentum among the planets, evolving their eccentricities and inclinations. To second order in the planets' eccentricities and inclinations, the eccentricity and inclination perturbations are decoupled. Given the right variable choice, the relevant differential equations are linear and thus the eccentricity and inclination behaviors can be described as a sum of eigenmodes. Since the underlying structure of the secular eigenmodes can be calculated using only the planets' masses and semi-major axes, one can elucidate the eccentricity and inclination behavior of planets in exoplanet systems even without knowing the planets' current eccentricities and inclinations. I have calculated both the eccentricity and inclination secular eigenmodes for the population of known multi-planet systems whose planets have well determined masses and periods. Using this catalog, and assuming a Gausian distribution for the eigenmode amplitudes and a uniform distribution for the eigenmode phases, I have predicted what range of precession rates the planets may have. Generally, planets that have more than one eigenmode significantly contribute to their eccentricity ('groupies') can have a wide range of possible precession rates, while planets that are 'loners' have a narrow range of possible precession rates. One might have assumed that in any given system, the planets with shorter periods would have faster precession rates. However, I show that in systems where the planets suffer strong secular interactions this is not necessarily the case.

Secular Trends in Menarcheal Age in India-Evidence from the Indian Human Development Survey

PubMed Central

Pathak, Praveen Kumar; Tripathi, Niharika; Subramanian, S. V.

2014-01-01

Background Evidence from a number of countries in Europe and North America point towards the secular declining trend in menarcheal age with considerable spatial variations over the past two centuries. Similar trends were reported in several developing countries from Asia, Africa and Latin America. However, data corroborating any secular trend in the menarcheal age of the Indian population remained sparse and inadequately verified. Methods We examined secular trends, regional heterogeneity and association of socioeconomic, anthropometric and contextual factors with menarcheal age among ever-married women (15–49 years) in India. Using the pseudo cohort data approach, we fit multiple linear regression models to estimate secular trends in menarcheal age of 91394 ever-married women using the Indian Human Development Survey. Results The mean age at menarche among Indian women was 13.76 years (95 % CI: 13.75, 13.77) in 2005. It declined by three months from 13.83 years (95% CI: 13.81, 13.85) among women born prior to 1955–1964, to nearly 13.62 years (95% CI: 13.58, 13.67) among women born during late 1985–1989. However, these aggregate national figures mask extensive spatial heterogeneity as mean age at menarche varied from 15.0 years in Himachal Pradesh during 1955–1964 (95% CI: 14.89–15.11) to about 12.1 years in Assam (95% CI: 11.63–12.56) during 1985–1989. Conclusion The regression analysis established a reduction of nearly one month per decade, suggesting a secular decline in age at menarche among Indian women. Notably, the menarcheal age was significantly associated with the area of residence, geographic region, linguistic groups, educational attainment, wealth status, caste and religious affiliations among Indian women. PMID:25369507

Geodetic estimates of fault slip rates in the San Francisco Bay area

USGS Publications Warehouse

Savage, J.C.; Svarc, J.L.; Prescott, W.H.

1999-01-01

Bourne et al. [1998] have suggested that the interseismic velocity profile at the surface across a transform plate boundary is a replica of the secular velocity profile at depth in the plastosphere. On the other hand, in the viscoelastic coupling model the shape of the interseismic surface velocity profile is a consequence of plastosphere relaxation following the previous rupture of the faults that make up the plate boundary and is not directly related to the secular flow in the plastosphere. The two models appear to be incompatible. If the plate boundary is composed of several subparallel faults and the interseismic surface velocity profile across the boundary known, each model predicts the secular slip rates on the faults which make up the boundary. As suggested by Bourne et al., the models can then be tested by comparing the predicted secular slip rates to those estimated from long-term offsets inferred from geology. Here we apply that test to the secular slip rates predicted for the principal faults (San Andreas, San Gregorio, Hayward, Calaveras, Rodgers Creek, Green Valley and Greenville faults) in the San Andreas fault system in the San Francisco Bay area. The estimates from the two models generally agree with one another and to a lesser extent with the geologic estimate. Because the viscoelastic coupling model has been equally successful in estimating secular slip rates on the various fault strands at a diffuse plate boundary, the success of the model of Bourne et al. [1998] in doing the same thing should not be taken as proof that the interseismic velocity profile across the plate boundary at the surface is a replica of the velocity profile at depth in the plastosphere.

Religion, Education and the Post-Secular Child

ERIC Educational Resources Information Center

Davis, Robert A.

2014-01-01

This essay endeavours to reframe current discussion of the relationship of religion to education by highlighting an often seriously neglected element of contemporary educational thought: the changing, post-secular understanding of childhood in the globalised age. Drawing upon recent ethnographies of childhood, and an older anthropological…

Secular trends on traditional ecological knowledge: An analysis of different domains of knowledge among Tsimane' men.

PubMed

Reyes-García, Victoria; Luz, Ana C; Gueze, Maximilien; Paneque-Gálvez, Jaime; Macía, Manuel J; Orta-Martínez, Martí; Pino, Joan

2013-10-01

Empirical research provides contradictory evidence of the loss of traditional ecological knowledge across societies. Researchers have argued that culture, methodological differences, and site-specific conditions are responsible for such contradictory evidences. We advance and test a third explanation: the adaptive nature of traditional ecological knowledge systems. Specifically, we test whether different domains of traditional ecological knowledge experience different secular changes and analyze trends in the context of other changes in livelihoods. We use data collected among 651 Tsimane' men (Bolivian Amazon). Our findings indicate that different domains of knowledge follow different secular trends. Among the domains of knowledge analyzed, medicinal and wild edible knowledge appear as the most vulnerable; canoe building and firewood knowledge seem to remain constant across generations; whereas house building knowledge seems to experience a slight secular increase. Our analysis reflects on the adaptive nature of traditional ecological knowledge, highlighting how changes in this knowledge system respond to the particular needs of a society in a given point of time.

Main field and secular variation modeling with Defense Meteorological Satellite Program magnetic measurements

NASA Astrophysics Data System (ADS)

Alken, P.; Olsen, N.; Finlay, C. C.; Chulliat, A.

2017-12-01

In order to investigate the spatial structure and development of rapid (sub-decadal) changes in the geomagnetic core field, including its secular variation and acceleration, global magnetic measurements from space play a crucial role. With the end of the CHAMP mission in September 2010, there has been a gap in high-quality satellite magnetic field measurements until the Swarm mission was launched in November 2013. Geomagnetic main field models during this period have relied on the global ground observatory network which, due to its sparse spatial configuration, has difficulty in resolving secular variation and acceleration at higher spherical harmonic degrees. In this presentation we will show new results in building main field models during this "gap period", based on vector magnetic measurements from four Defense Meteorological Satellite Program (DMSP) satellites. While the fluxgate instruments onboard DMSP were not designed for high-quality core field modeling, we find that the DMSP dataset can provide valuable information on secular variation and acceleration during the gap period.

β-Decay Half-Lives of 110 Neutron-Rich Nuclei across the N=82 Shell Gap: Implications for the Mechanism and Universality of the Astrophysical r Process.

PubMed

Lorusso, G; Nishimura, S; Xu, Z Y; Jungclaus, A; Shimizu, Y; Simpson, G S; Söderström, P-A; Watanabe, H; Browne, F; Doornenbal, P; Gey, G; Jung, H S; Meyer, B; Sumikama, T; Taprogge, J; Vajta, Zs; Wu, J; Baba, H; Benzoni, G; Chae, K Y; Crespi, F C L; Fukuda, N; Gernhäuser, R; Inabe, N; Isobe, T; Kajino, T; Kameda, D; Kim, G D; Kim, Y-K; Kojouharov, I; Kondev, F G; Kubo, T; Kurz, N; Kwon, Y K; Lane, G J; Li, Z; Montaner-Pizá, A; Moschner, K; Naqvi, F; Niikura, M; Nishibata, H; Odahara, A; Orlandi, R; Patel, Z; Podolyák, Zs; Sakurai, H; Schaffner, H; Schury, P; Shibagaki, S; Steiger, K; Suzuki, H; Takeda, H; Wendt, A; Yagi, A; Yoshinaga, K

2015-05-15

The β-decay half-lives of 110 neutron-rich isotopes of the elements from _{37}Rb to _{50}Sn were measured at the Radioactive Isotope Beam Factory. The 40 new half-lives follow robust systematics and highlight the persistence of shell effects. The new data have direct implications for r-process calculations and reinforce the notion that the second (A≈130) and the rare-earth-element (A≈160) abundance peaks may result from the freeze-out of an (n,γ)⇄(γ,n) equilibrium. In such an equilibrium, the new half-lives are important factors determining the abundance of rare-earth elements, and allow for a more reliable discussion of the r process universality. It is anticipated that universality may not extend to the elements Sn, Sb, I, and Cs, making the detection of these elements in metal-poor stars of the utmost importance to determine the exact conditions of individual r-process events.

[Disposal of radioactive contaminated waste from Ga-68-PET - calculation of a clearance level for Ge-68].

PubMed

Solle, Alexander; Wanke, Carsten; Geworski, Lilli

2017-03-01

Ga-68-labeled radiotracers, particularly used for the detection of neuroendocrine tumors by means of Ga-68-DOTA-TATE or -DOTA-TOC or for the diagnosis of prostate cancer by means of Ga-68-labeled antigens (Ga 68-PSMA), become increasingly important. In addition to the high sensitivity and specificity of these radiopharmaceuticals, the short-lived radionuclide Ga-68 offers almost ideal nuclear characteristics for use in PET. Ga-68 is obtained from a germanium-gallium-generator system, so that the availability of Ga-68-labeled radiotracers is independent of an on-site-cyclotron regardless of the short half-life of Ga-68 of about 68minutes. Regarding the disposal of the radioactively contaminated waste from the preparation of the radiopharmaceutical, the eluted Ga-68 has to be considered to be additionally contaminated with its parent nuclide Ge-68. Due to this production-related impurity in combination with the short half-life of Ga-68, the radioactive waste has to be considered to be contaminated with Ge-68 and Ga-68 in radioactive equilibrium (hereafter referred to as Ge-68+). As there are no clearance levels for Ge-68+ given in the German Radiation Protection Ordinance, this work presents a method to calculate the missing value basing on a recommendation of the German Radiation Protection Commission in combination with simple geometric models of practical radiation protection. Regarding the relevant exposure scenarios, a limit value for the unrestricted clearance of Ge-68+ of 0.4 Bq/g was determined. Copyright © 2016. Published by Elsevier GmbH.

Gods, Germs, and Petri Dishes: Toward a Nonsecular Medical Anthropology.

PubMed

Roberts, Elizabeth F S

2016-01-01

This commentary calls on medical anthropology to become programmatically non-secular. Despite recent anthropological critiques of secularity, within and outside of anthropology, most contemporary medical anthropologists continue to leave deities and religiosity out of their examinations of healing practices, especially in their accounts of biomedicine. Through a critical, relational constructionist lens, which traces how all entities are both constructed and real, a non-secular medical anthropology would insist that when deities are part of medical practice, they are integral to analysis. Importantly then, within the symmetrical nature of this same constructionist lens, biomedical entities like germs and petri dishes need to be accounted for just as much as deities.

Asteroid proper elements and secular resonances

NASA Technical Reports Server (NTRS)

Knezevic, Zoran; Milani, Andrea

1992-01-01

In a series of papers (e.g., Knezevic, 1991; Milani and Knezevic, 1990; 1991) we reported on the progress we were making in computing asteroid proper elements, both as regards their accuracy and long-term stability. Additionally, we reported on the efficiency and 'intelligence' of our software. At the same time, we studied the associated problems of resonance effects, and we introduced the new class of 'nonlinear' secular resonances; we determined the locations of these secular resonances in proper-element phase space and analyzed their impact on the asteroid family classification. Here we would like to summarize the current status of our work and possible further developments.

Conflicts between conservative Christian institutions and secular groups in sub-Saharan Africa: Ideological discourses on sexualities, reproduction, and HIV/AIDS

PubMed Central

Mantell, Joanne E.; Correale, Jacqueline; Adams-Skinner, Jessica; Stein, Zena A.

2011-01-01

Religious and secular institutions advocate strategies that represent all points on the continuum to reduce the spread of HIV/AIDS. Drawing on an extensive literature review of studies conducted in sub-Saharan Africa, we focus on those secular institutions that support all effective methods of reducing HIV/AIDS transmission and those conservative religious institutions that support a limited set of prevention methods. We conclude by identifying topics for dialogue between these viewpoints that should facilitate cooperation by expanding the generally acceptable HIV/AIDS prevention methods, and especially the use of condoms. PMID:21834733

Self-Transcendence: Integrating Ends and Means in Value Counseling.

ERIC Educational Resources Information Center

Conn, Walter E.

1994-01-01

Compares pastoral and secular counseling, suggesting that pastoral counseling is distinctively specified by limit experiences. Relates Lonergan's view of self-transcendence to Egan's three-stage model and various approaches summarized by Corey. Concludes that, although distinctive in some ways, pastoral counseling and secular counseling are…

Experiences of Christian Clients in Secular Psychotherapy: A Mixed-Methods Investigation

ERIC Educational Resources Information Center

Cragun, Carrie L.; Friedlander, Myrna L.

2012-01-01

Eleven Christian former clients were sampled to uncover factors contributing to positive versus negative experiences in secular psychotherapy. The qualitative results indicated that although many participants felt hesitant to discuss their faith due to uncertainty about their therapists' reactions, positive experiences were reportedly facilitated…

#Digitalfaith: Using Social Media for Professional Development

ERIC Educational Resources Information Center

Manson, Sable A.; Cordovés, Janett I.

2018-01-01

There is a need to identify and create spaces for professionals in higher education to engage religion, secularism, and spirituality in meaningful ways. #DigitalFaith resources are the digital platforms and communities supporting religious, secular, and spiritual development, and they offer potential avenues for professional development. This…

Supporting Muslim Students in Secular Public Schools

ERIC Educational Resources Information Center

Schlein, Candace; Chan, Elaine

2010-01-01

This article discusses the findings of a study examining the challenges and opportunities of supporting Muslim students in secular public schools. Education is explored as a multifaceted interplay between home and family life, community resources, school programs and policies, and classroom lessons to investigate the curricular experiences of…

Calling in Work: Secular or Sacred?

ERIC Educational Resources Information Center

Steger, Michael F.; Pickering, N. K.; Shin, J. Y.; Dik, B. J.

2010-01-01

Recent scholarship indicates that people who view their work as a calling are more satisfied with their work and their lives. Historically, calling has been regarded as a religious experience, although modern researchers frequently have adopted a more expansive and secular conceptualization of calling, emphasizing meaning and personal fulfillment…

Birch Lecture : The Deep Roots of Continents

NASA Astrophysics Data System (ADS)

Jaupart, C.

2006-12-01

The roots of Archean continents are made of depleted and buoyant mantle and may extend to depths larger than 250 km. Such distinctive characteristics have key dynamical and geological consequences that we are only beginning to address. Thick roots provide large volume repositories for chemical elements that do not mix with Earth's convecting interior. Their large diffusive relaxation time implies long-term thermal disequilibrium with their radioactive heat sources and with the cooling of the mantle. Their negative thermal buoyancy may drive convective instabilities with implications for intracontinental deformation and magmatism as well as for continental growth. The dynamical behaviour of continental roots depends on the buoyancy ratio B, the ratio of the intrinsic (chemical) buoyancy of depleted lithospheric mantle and the density difference due to thermal expansion. The lithosphere can be mechanically stable and in thermal equilibrium with heat supplied by small-scale convection at the top of the asthenosphere. Sufficient cooling may result in an oscillatory convective instability whereby perturbations to the base of the lithosphere rise and fall periodically. The lithosphere seems to have developed in a state near that of instability with different thicknesses depending on its intrinsic buoyancy. It may have grown not only by chemical differentiation during melting, but also by oscillatory convection entraining chemically denser material from the asthenosphere. Mantle plumes have different effects on lithospheres of different thicknesses and compositions. For B values larger than about 0.6, plume material does not really penetrate into the lithosphere and spreads beneath it. In this case, the buoyancy force that is applied to the base of the lithosphere drives moderate thinning and extension over large horizontal distances. It takes values of B less than 0.6 to achieve true plume penetration with a significant vertical velocity component. In this case, thinning and extension get localized above the rising plume. In both cases, heated lithosphere material becomes convectively unstable after some time and entrains asthenospheric material as it rises. Temperatures in thick continental lithosphere do not adjust rapidly to secular changes of mantle temperature. Analysis of (P,T) data from xenolith studies indicates that the Earth's mantle has cooled at a rate of 80 K Ga-1 or less. Thick continental roots preserve a record of Archean processes and of Earth's evolution through geological ages. Deciphering this record may well be our next challenge.

238U, and its decay products, in grasses from an abandoned uranium mine

NASA Astrophysics Data System (ADS)

Childs, Edgar; Maskall, John; Millward, Geoffrey

2016-04-01

Bioaccumulation of radioactive contaminants by plants is of concern particularly where the sward is an essential part of the diet of ruminants. The abandoned South Terras uranium mine, south west England, had primary deposits of uraninite (UO2) and pitchblende (U3O8), which contained up to 30% uranium. When the mine was active uranium and radium were extracted but following closure it was abandoned without remediation. Waste rock and gangue, consisting of inefficiently processed minerals, were spread around the site, including a field where ruminants are grazed. Here we report the activity concentrations of 238U, 235U 214,210Pb, and the concentrations of selected metals in the soils, roots and leaves of grasses taken from the contaminated field. Soil samples were collected at the surface, and at 30 cm depth, using an auger along a 10-point transect in the field from the foot of a waste heap. Whole, individual grass plants were removed with a spade, ensuring that their roots were intact. The soils and roots and grass leaves were freeze-dried. Activity concentrations of the radionuclides were determined by gamma spectroscopy, following 30 days incubation for development of secular equilibrium. Dried soils, roots and grasses were also digested in aqua regia and the concentrations of elements determined by ICP techniques. Maximum activity concentrations of 238U, 235U, 214Pb and 210Pb surface soils were 63,300, 4,510, 23,300 and 49,400 Bq kg-1, respectively. The mean 238U:235U ratio was 11.8 ± 1.8, an order of magnitude lower than the natural value of 138, indicating disequilibrium within the decay chain due to mineral processing. Radionuclides in the roots had 5 times lower concentration and only grass leaves in the vicinity of the waste heap had measureable values. The mean soil to root transfer factor for 238U was 36%, the mean root to leaf was 3% and overall only 0.7% of 238U was transferred from the soil to the leaves. The roots contained 0.8% iron, possibly as iron plaque acting to mediate 238U transfer within the plants. The results are discussed in the context of remediation of grazing land contaminated with radionuclides.

Magnetic Navigation in Sea Turtles: Insights from Secular Variation

NASA Astrophysics Data System (ADS)

Putman, N. F.; Lohmann, K.

2011-12-01

Sea turtles are iconic migrants that posses a sensitive magnetic-sense that guides their long-distance movements in a variety of contexts. In the first few hours after hatching turtles use the magnetic field to maintain an offshore compass heading to reach deeper water, out of the reach of nearshore predators. Young turtles engage in directed swimming in response to regional magnetic fields that exist along their transoceanic migratory path. Older turtles also use magnetic information to relocate foraging sites and islands used for nesting after displacement. Numerous hypotheses have been put forth to explain how magnetic information functions in these movements, however, there is little consensus among animal navigation researchers. A particular vexing issue is how magnetic navigation can function under the constraints of the constant, gradual shifting of the earth's magnetic field (secular variation). Here, I present a framework based on models of recent geomagnetic secular variation to explore several navigational mechanisms proposed for sea turtles. I show that while examination of secular variation likely falsifies some hypothetical navigational strategies, it provides key insights into the selective pressures that could maintain other navigational mechanisms. Moreover, examination of secular variation's influence on the navigational precision in reproductive migrations of sea turtles offers compelling explanations for the population structure along sea turtle nesting beaches as well as spatiotemporal variation in nesting turtle abundance.

Body image and eating behaviors in Orthodox and Secular Jewish women.

PubMed

Gluck, Marci E; Geliebter, Allan

2002-01-01

To explore the impact of religion on the development of disturbances in body image and eating behaviors. 78 Orthodox Jewish women were compared with 48 secular Jewish women. Participants completed the Body Shape Questionnaire (BSQ), the Eating Disorder Examination-Questionnaire Version (EDE-Q), and the Figure Rating Scale (FRS). Despite a similar body mass index of 22.2 +/- 2.8 SDs, the secular women scored significantly higher on the BSQ (P = .005) and the EDE-Q (P = .004) than the Orthodox women. The secular women also had greater eating disorder symptomatology: more laxative use (P = .02) and a trend toward more vomiting (P = .06) and diuretic use (P = .06), although not more binge eating. They were twice as likely to have a fear of becoming fat (P = .05) and were four times as likely to be influenced by their shape and weight (P = .001). Also, despite increased media exposure, the secular group chose an ideal body size on the FRS similar to that of the Orthodox group, suggesting that their greater body dissatisfaction on the BSQ was related, instead, to greater cultural pressure for thinness (P = .007) and more shame about appearance (P = .04). Our findings show that membership in a strict, insulated religious group such as Orthodox Judaism may protect women, to some extent, from developing body dissatisfaction and eating pathology.

The Mid-plane of the Main Asteroid Belt

NASA Astrophysics Data System (ADS)

Cambioni, Saverio; Malhotra, Renu

2018-03-01

We measure the mid-plane of the main asteroid belt by using the observational data of a nearly complete and unbiased sample of asteroids and find that it has inclination \\bar{I}=0\\buildrel{\\circ}\\over{.} 93+/- 0\\buildrel{\\circ}\\over{.} 04 and longitude of ascending node \\bar{{{Ω }}}=87\\buildrel{\\circ}\\over{.} 6+/- 2\\buildrel{\\circ}\\over{.} 6 (in J2000 ecliptic-equinox coordinate system). This plane differs significantly from previously published measurements, and it is also distinctly different than the solar system’s invariable plane as well as Jupiter’s orbit plane. The mid-plane of the asteroid belt is theoretically expected to be a slightly warped sheet whose local normal is controlled by the gravity of the major planets. Specifically, its inclination and longitude of ascending node varies with semimajor axis and time (on secular timescales) and is defined by the forced solution of secular perturbation theory; the ν 16 nodal secular resonance is predicted to cause a significant warp of the mid-plane in the inner asteroid belt. We test the secular theory by measuring the current location of the asteroids’ mid-plane in finer semimajor axis bins. We find that the measured mid-plane in the middle and outer asteroid belt is consistent, within the 3σ confidence level, with the prediction of secular perturbation theory, but a notable discrepancy is present in the inner asteroid belt near ∼2 au.

Geographical Distribution of Principals in Israeli Schools

ERIC Educational Resources Information Center

Lebental, Dana M.

2015-01-01

This quantitative investigation focuses on women high school principals at Jewish secular schools throughout Israel. Despite challenges, Israeli women have succeeded in obtaining over half of the principal positions at Jewish secular high schools, but the degree to which there is equal gender access to leadership roles in the school system remains…

Secular Life Philosophy as a Subject in Schools in Norway.

ERIC Educational Resources Information Center

Horn, Kristian

1981-01-01

In Norway changes in legislation in recent years have loosened the firm hold of Christian philosophy in the schools and given room for alternative secular philosophy. This article presents background information and an outline of the basic plan for life philosophy as a school subject. (Author/SJL)

The elements of the Earth's magnetism and their secular changes between 1550 and 1915

NASA Technical Reports Server (NTRS)

Fritsche, H.

1983-01-01

The results of an investigation about the magnetic agents outside the Earth's surface as well as the Earth's magnetic elements for the epochs 1550, 1900, 1915 are presented. The secular changes of the Earth's magnetic elements during the time interval 1550 - 1900 are also included.

Religious Literacies in a Secular Literacy Classroom

ERIC Educational Resources Information Center

Skerrett, Allison

2014-01-01

This article examines how a literacy teacher and her students engaged students' Christian religious literacies in a secular classroom and the outcomes of those transactions. Case study methods; scholarship offering historical, cultural, and social perspectives on Christian religious literacies; and the New London Group's theory of a pedagogy of…

The Emergence of Three Distinct Worldviews among American College Students

ERIC Educational Resources Information Center

Keysar, Ariela

2013-01-01

American college students' worldviews affect what they value, the way they behave and potentially how they learn. The study described in this article finds that today's students are divided not dichotomously, between religious and secular, but rather among three distinct worldviews: religious, secular, and spiritual. The author asserts that…

Post-Secularism, Religious Knowledge and Religious Education

ERIC Educational Resources Information Center

Carr, David

2012-01-01

Post-secularism seems to follow in the wake of other (what are here called) "postal" perspectives--post-structuralism, postmodernism, post-empiricism, post-positivism, post-analytical philosophy, post-foundationalism and so on--in questioning or repudiating what it takes to be the epistemic assumptions of "modernism." To be sure, post-secularism…

New Opportunities and Old Challenges: Romanian Denominational Higher Education in the Bologna Process

ERIC Educational Resources Information Center

Szolar, Eva

2010-01-01

The Europeanization process has created new opportunities for Romanian Christian higher education institutions, but these are coupled with new waves of secularization. The secularization and the transformation of institutional identity are the result of inner institutional decisions only apparently, since these decisions were undertaken in order…

Sociology Dismissing Religion? The Presentation of Religious Change in Introductory Sociology Textbooks

ERIC Educational Resources Information Center

Featherstone, Richard; Sorrell, Katie L.

2007-01-01

This paper explores whether the field of sociology harbors a dismissive attitude towards religion. Specifically it examines whether introductory sociology textbooks present the classic secularization theory over the more recent religious economies explanation of religious change. The classical secularization thesis suggests that religion is…

A Multi-Disciplinary Inquiry of Secular and Christian Approaches to Sex Education

ERIC Educational Resources Information Center

Yu, Chong Ho; Lee, Hyun Seo

2018-01-01

Secular scholars have criticized Christian education and counseling on sex as restrictive, ineffective, and outdated. The authors of the current study explored both common non-Christian and Christian approaches to human sexuality with reference to overarching domains of religion, philosophy, psychology, sociology, and anthropology. Secular…

The Unique and the Unifying: Children's Narratives of Cultural Differences.

ERIC Educational Resources Information Center

Roer-Strier, Dorit; Weil, Shalva; Adan, Hila

2003-01-01

Examined effects of planned encounters between religious and secular Jewish children and parents at a school in Jerusalem, Israel, on perceptions of religiosity and secularism. Results suggest that each group was aware of its affiliation, could discern similarities and differences, and did not have stereotyped perceptions. Social encounters…

Adolescents' Goal Orientations for Science in Single-Gender Israeli Religious Schools

ERIC Educational Resources Information Center

Fortus, David; Daphna, Limor

2017-01-01

Israeli students and their families can choose between state-funded secular, religious, orthodox, and other alternative schools (e.g., Waldorf, Montessori, democratic). Earlier studies showed that the motivation to engage with science differs greatly between Israeli students in secular schools and democratic schools, with these differences being…

Religion, Education, and Secularism in International Agencies

ERIC Educational Resources Information Center

Stambach, Amy; Marshall, Katherine; Nelson, Matthew J.; Andreescu, Liviu; Kwayu, Aikande C.; Wexler, Philip; Hotam, Yotam; Fischer, Shlomo; El Bilawi, Hassan

2011-01-01

During the interwar years of the early twentieth century, and through at least the 1980s, education was seen by scholars, state leaders, and international agency representatives alike as a way to modernize and secularize underdeveloped communities. Arguments about the modernizing power of education did not erase or discount the presence of…

Students' Attitudes toward Religion

ERIC Educational Resources Information Center

Lebedev, S. D.

2008-01-01

The problem of the study of religion in the system of secular education hinges on the "reproduction of religiousness" in the secular school and, more broadly, in Russian society space, via the process of mass education. It is the prospect of expanded reproduction of religious consciousness, of religious psychology and practices as a…

Tidally Heated Terrestrial Exoplanets

NASA Astrophysics Data System (ADS)

Henning, Wade Garrett

This work models the surface and internal temperatures for hypothetical terrestrial planets in situations involving extreme tidal heating. The feasibility of such planets is evaluated in terms of the orbital perturbations that may give rise to them, their required proximity to a hoststar, and the potential for the input tidal heating to cause significant partial melting of the mantle. Trapping terrestrial planets into 2:1 resonances with migrating Hot Jupiters is considered as a reasonable way for Earth-like worlds to both maintain high eccentricities and to move to short enough orbital periods (1-20 days) for extreme tidal heating to occur. Secular resonance and secular orbital perturbations may support moderate tidal heating at a low equilibrium eccentricity. At orbital periods below 10-30 days, with eccentricities from 0.01 to 0.1, tidal heat may greatly exceed radiogenic heat production. It is unlikely to exceed insolation, except when orbiting very low luminosity hosts, and thus will have limited surface temperature expression. Observations of such bodies many not be able to detect tidal surface enhancements given a few percent uncertainty in albedo, except on the nightside of spin synchronous airless objects. Otherwise detection may occur via spectral detection of hotspots or high volcanic gas concentrations including sulfur dioxide and hydrogen sulfide. The most extreme cases may be able to produce magma oceans, or magma slush mantles with up to 40-60% melt fractions. Tides may alter the habitable zones for smaller red dwarf stars, but are generally detrimental. Multiple viscoelastic models, including the Maxwell, Voigt-Kelvin, Standard Anelastic Solid, and Burgers rheologies are explored and applied to objects such as Io and the super-Earth planet GJ 876d. The complex valued Love number for the Burgers rheology is derived and found to be a useful improvement when modeling the low temperature behavior of tidal bodies, particularly during low eccentricity excursions. Viscoelastic solutions for GJ 876d are typical of extreme short period high eccentricity objects with tidal-convectiveequilibrium heat rates between ˜10,000 to 500,000 terawatts.

On the binary helium star DY Centauri: chemical composition and evolutionary state

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

Pandey, Gajendra; Rao, N. Kameswara; Jeffery, C. Simon

2014-10-01

DY Cen has shown a steady fading of its visual light by about one magnitude in the last 40 yr, suggesting a secular increase in its effective temperature. We have conducted non-local thermodynamic equilibrium (LTE) and LTE abundance analyses to determine the star's effective temperature, surface gravity, and chemical composition using high-resolution spectra obtained over two decades. The derived stellar parameters for three epochs suggest that DY Cen has evolved at a constant luminosity and has become hotter by about 5000 K in 23 yr. We show that the derived abundances remain unchanged for the three epochs. The derived abundancesmore » of the key elements, including F and Ne, are as observed for the extreme helium stars resulting from a merger of a He white dwarf with a C-O white dwarf. Thus DY Cen by chemical composition appears to also be a product of a merger of two white dwarfs. This appearance seems to be at odds with the recent suggestion that DY Cen is a single-lined spectroscopic binary.« less

Questions about Mercury's role in comparative planetary geophysics

NASA Technical Reports Server (NTRS)

Chapman, C. R.; Weidenschilling, S. J.; Davis, D. R.; Greenberg, R.; Leake, M. A.

1985-01-01

Problems which have arisen in formulating a mutually consistent picture of Mercury's evolution are outlined. It appears that one or more of the following widely adopted assumptions are wrong about Mercury: (1) its original composition at least approximately resulted from equilibrium condensation; (2) its magnetic field arises from a still-active dynamo; (3) its thermal evolution should have yielded early core formation followed by cooling and a global contraction approaching 20 km in the planet's radius; (4) Mercury's surface is basaltic and the intercrater plains are of volcanic origin. It is suggested that Mercury's role in comparative planetology be reevaluated in the context of an alternative timescale based on the possibility that Mercury was subjected to a continuing source of cratering projectiles over recent aeons, which have not impacted the other terrestrial planets. Although such vulcanoids have not yet been discovered, the evolution of Mercury's orbit due to secular perturbations could well have led to a prolonged period of sweeping out any intra-Mercurian planetesimals that were originally present. Mercury's surface could be younger than previously believed, which explains why Mercury's core is still molten.

Brachiopod δ18O values do reflect ambient oceanography: Lacepede Shelf, southern Australia

NASA Astrophysics Data System (ADS)

James, Noel P.; Bone, Yvonne; Kurtis Kyser, T.

1997-06-01

Although commonly used as proxies for attributes of ancient ocean waters, the δ18O values of brachiopods from modern seas are little studied. To evaluate the utility of brachiopods as recorders of regional oceanography, modern shells from the Lacepede Shelf (25 000 km2) of southern Australia were analyzed for δ18O, and the results were compared to the values of ambient seawater. Southern Ocean waters cover this area of extensive cool-water carbonate deposition, but there are distinct sectors of seasonal upwelling and lesser fluvial outflow. δ18O values of brachiopods across the environmental spectrum from 40 to 300 m water depth are in general isotopic equilibrium with surrounding seawater. Nevertheless, δ18O values from individual sample sites vary as much as 0.60‰. The area of cold-water upwelling in particular is clearly delimited by a group of high δ18O values. The range of values across this one shelf, on the order of 2.5‰, is similar to the range of values postulated on the basis of similar results for secular changes in many ancient oceans.

Establishing a NORM based radiation calibration facility.

PubMed

Wallace, J

2016-05-01

An environmental radiation calibration facility has been constructed by the Radiation and Nuclear Sciences unit of Queensland Health at the Forensic and Scientific Services Coopers Plains campus in Brisbane. This facility consists of five low density concrete pads, spiked with a NORM source, to simulate soil and effectively provide a number of semi-infinite uniformly distributed sources for improved energy response calibrations of radiation equipment used in NORM measurements. The pads have been sealed with an environmental epoxy compound to restrict radon loss and so enhance the quality of secular equilibrium achieved. Monte Carlo models (MCNP),used to establish suitable design parameters and identify appropriate geometric correction factors linking the air kerma measured above these calibration pads to that predicted for an infinite plane using adjusted ICRU53 data, are discussed. Use of these correction factors as well as adjustments for cosmic radiation and the impact of surrounding low levels of NORM in the soil, allows for good agreement between the radiation fields predicted and measured above the pads at both 0.15 m and 1 m. Copyright © 2016 Elsevier Ltd. All rights reserved.

Atmospheric helium and geomagnetic field reversals.

NASA Technical Reports Server (NTRS)

Sheldon, W. R.; Kern, J. W.

1972-01-01

The problem of the earth's helium budget is examined in the light of recent work on the interaction of the solar wind with nonmagnetic planets. It is proposed that the dominant mode of helium (He4) loss is ion pumping by the solar wind during geomagnetic field reversals, when the earth's magnetic field is very small. The interaction of the solar wind with the earth's upper atmosphere during such a period is found to involve the formation of a bow shock. The penetration altitude of the shock-heated solar plasma is calculated to be about 700 km, and ionization rates above this level are estimated for a cascade ionization (electron avalanche) process to average 10 to the 9th power ions/sq cm/sec. The calculated ionization rates and the capacity of the solar wind to remove ionized helium (He4) from the upper atmosphere during geomagnetic dipole reversals are sufficient to yield a secular equilibrium over geologic time scales. The upward transport of helium from the lower atmosphere under these conditions is found to be adequate to sustain the proposed loss rate.

Non-destructive in-situ method and apparatus for determining radionuclide depth in media

DOEpatents

Xu, X. George; Naessens, Edward P.

2003-01-01

A non-destructive method and apparatus which is based on in-situ gamma spectroscopy is used to determine the depth of radiological contamination in media such as concrete. An algorithm, Gamma Penetration Depth Unfolding Algorithm (GPDUA), uses point kernel techniques to predict the depth of contamination based on the results of uncollided peak information from the in-situ gamma spectroscopy. The invention is better, faster, safer, and/cheaper than the current practice in decontamination and decommissioning of facilities that are slow, rough and unsafe. The invention uses a priori knowledge of the contaminant source distribution. The applicable radiological contaminants of interest are any isotopes that emit two or more gamma rays per disintegration or isotopes that emit a single gamma ray but have gamma-emitting progeny in secular equilibrium with its parent (e.g., .sup.60 Co, .sup.235 U, and .sup.137 Cs to name a few). The predicted depths from the GPDUA algorithm using Monte Carlo N-Particle Transport Code (MCNP) simulations and laboratory experiments using .sup.60 Co have consistently produced predicted depths within 20% of the actual or known depth.

Uranium-isotope variations in groundwaters of the Floridan aquifer and Boulder Zone of south Florida

USGS Publications Warehouse

Cowart, J.B.; Kaufman, M.I.; Osmond, J.K.

1978-01-01

Water samples from four wells from the main Floridan aquifer (300-400 m below mean sea level) in southeast Florida exhibit 234U 233U activity ratios that are significantly lower than the secular equilibrium value of 1.00. Such anomalous values have been observed previously only in waters from sedimentary aquifers in the near-surface oxidizing environments. These four wells differ from six others, all producing from the same general horizon, in being located in cavernous highly transmissive zones. We hypothesize that the low activity ratios are indicative of a relic circulation pattern whereby water from the surface aquifer was channelled to lower levels when sea level was much lower. At a deeper cavernous level, known as the Boulder Zone (800-1,000 m below mean sea level), the U isotopes, along with other chemical constituents, show progressive changes with increasing distance from an inferred flow source in the Straits of Florida. This tends to support the hypothesized landward flow (though with a more northerly component) of cold seawater in the extensively transmissive Boulder Zone. ?? 1978.

Radium-226 content of agricultural gypsums

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

Lindeken, C.L.; Coles, D.G.

1977-01-01

Gypsum (CaSO/sub 4/ . 2H/sub 2/O), used as a soil amendment for saline-alkali soils, is obtained either by quarrying or as a by-product in the phosphate fertilizer industry. The latter, termed phospho gypsum, contains variable amounts of /sup 226/Ra, depending on the uranium content of the phosphate rock. Radium-226 contents of both quarried and phospho gypsum were determined by gamma counting in a low-background Ge(Li) spectrometer equipped with Compton suppression. Quarried samples from Nova Scotia, Iowa, Texas, and California were compared with phospho gypsum derived from Florida land pebble phosphates. Quarried gypsums showed an average radium content of 0.21 pCi/g.more » The average radium in phospho gypsum was 14.6 pCi/g. Uranium-238 measurements showed that near secular equilibrium existed between the uranium and radium in the quarried samples. Disequilibrium in the phospho gypsums occurred because of the preferential separation of radium during chemical processing. At the levels observed, no health hazard is implied from uptake of radium by plants grown in phospho gypsum treated soil.« less

How Irreversible Heat Transport Processes Drive Earth's Interdependent Thermal, Structural, and Chemical Evolution Providing a Strongly Heterogeneous, Layered Mantle

NASA Astrophysics Data System (ADS)

Hofmeister, A.; Criss, R. E.

2013-12-01

Because magmatism conveys radioactive isotopes plus latent heat rapidly upwards while advecting heat, this process links and controls the thermal and chemical evolution of Earth. We present evidence that the lower mantle-upper mantle boundary is a profound chemical discontinuity, leading to observed heterogeneities in the outermost layers that can be directly sampled, and construct an alternative view of Earth's internal workings. Earth's beginning involved cooling via explosive outgassing of substantial ice (mainly CO) buried with dust during accretion. High carbon content is expected from Solar abundances and ice in comets. Reaction of CO with metal provided a carbide-rich core while converting MgSiO3 to olivine via oxidizing reactions. Because thermodynamic law (and buoyancy of hot particles) indicates that primordial heat from gravitational segregation is neither large nor carried downwards, whereas differentiation forced radioactive elements upwards, formation of the core and lower mantle greatly cooled the Earth. Reference conductive geotherms, calculated using accurate and new thermal diffusivity data, require that heat-producing elements are sequestered above 670 km which limits convection to the upper mantle. These irreversible beginnings limit secular cooling to radioactive wind-down, permiting deduction of Earth's inventory of heat-producing elements from today's heat flux. Coupling our estimate for heat producing elements with meteoritic data indicates that Earth's oxide content has been underestimated. Density sorting segregated a Si-rich, peridotitic upper mantle from a refractory, oxide lower mantle with high Ca, Al and Ti contents, consistent with diamond inclusion mineralogy. Early and rapid differentiation means that internal temperatures have long been buffered by freezing of the inner core, allowing survival of crust as old as ca.4 Ga. Magmatism remains important. Melt escaping though stress-induced fractures in the rigid lithosphere imparts a lateral component and preferred direction to upper mantle circulation. Mid-ocean magma production over ca. 4 Ga has deposited a slab volume at 670 km that is equivalent to the transition zone, thereby continuing differentiation by creating a late-stage chemical discontinuity near 400 km. This ongoing process has generated the observed lateral and vertical heterogeneity above 670 km.

Salvaging the self in a world without soul: William James's The Principles of psychology.

PubMed

Coon, D J

2000-05-01

This article explores William James's transformation of the religious soul into the secular self in The Principles of Psychology. Although James's views on the self are familiar to many historians of psychology, the article places his treatment of the self within the broader social and cultural context of a secularizing, industrializing society. There were palpable tensions and anxieties that accompanied the cultural shift, and these are particularly transparent in James's Principles. James attempted the project of secularizing the soul in order to promote a natural science of the mind but with marked ambivalence for the project, because it left out some of the moral and metaphysical questions of great interest to him.

Career plans for male-dominated occupations among female seniors in religious and secular high schools.

PubMed

Rich, Y; Golan, R

1992-01-01

This study investigated the hypothesis that the religious beliefs of young women significantly affect their career planning. All female seniors (N = 315) in one public religious and two public secular high schools in Israel responded to inventories examining their (1) orientation to homemaking or career, (2) interest in male-dominated occupations, and (3) preference for male-dominated occupations. Results from regression analyses indicated that young women from the secular schools, as compared to those from the religious school, expressed greater interest in and preference for male-dominated occupations. In addition, religious orientation, more than other background variables, had predictive power for interest in and preference for male-dominated occupations.

Does religion deserve a place in secular medicine?

PubMed

Earp, Brian D

2015-11-01

Biggar (2015) argues that "religion" deserves a place in secular medicine. Against this view, I argue that religion (as most people would understand the term) should not play a role in shaping secular health policy, and I provide some illustrations of the potential dangers of the contrary. However, I also suggest that-upon closer inspection-Biggar seems to be using the term "religion" to refer to obliquely to what most people would call "moral philosophy." On this less controversial interpretation, Biggar's proposal is inoffensive-but also unoriginal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Present-day secular variations in the zonal harmonics of earth's geopotential

NASA Technical Reports Server (NTRS)

Mitrovica, J. X.; Peltier, W. R.

1993-01-01

The mathematical formulation required for predicting secular variation in the geopotential is developed for the case of a spherically symmetric, self-gravitating, viscoelastic earth model and an arbitrary surface load which can include a gravitational self-consistent ocean loading component. The theory is specifically applied to predict the present-day secular variation in the zonal harmonics of the geopotenial arising from the surface mass loading associated with the late Pleistocene glacial cycles. A procedure is outlined in which predictions of the present-day geopotential signal due to the late Pleistocene glacial cycles may be used to derive bounds on the net present-day mass flux from the Antarctic and Greenland ice sheets to the local oceans.

Kinetic analysis of central ( sup 11 C)raclopride binding to D2-dopamine receptors studied by PET--a comparison to the equilibrium analysis

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

Farde, L.; Eriksson, L.; Blomquist, G.

1989-10-01

(11C)Raclopride binding to central D2-dopamine receptors in humans has previously been examined by positron emission tomography (PET). Based on the rapid occurrence of binding equilibrium, a saturation analysis has been developed for the determination of receptor density (Bmax) and affinity (Kd). For analysis of PET measurements obtained with other ligands, a kinetic three-compartment model has been used. In the present study, the brain uptake of (11C)raclopride was analyzed further by applying both a kinetic and an equilibrium analysis to data obtained from four PET experiments in each of three healthy subjects. First regional CBV was determined. In the second andmore » third experiment, (11C)-raclopride with high and low specific activity was used. In a fourth experiment, the (11C)raclopride enantiomer (11C)FLB472 was used to examine the concentration of free radioligand and nonspecific binding in brain. Radio-activity in arterial blood was measured using an automated blood sampling system. Bmax and Kd values for (11C)raclopride binding could be determined also with the kinetic analysis. As expected theoretically, those values were similar to those obtained with the equilibrium analysis. In addition, the kinetic analysis allowed separate determination of the association and dissociation rate constants, kon and koff, respectively. Examination of (11C)raclopride and (11C)FLB472 uptake in brain regions devoid of specific D2-dopamine receptor binding indicated a fourth compartment in which uptake was reversible, nonstereoselective, and nonsaturable in the dose range studied.« less

Religious Diversity and Inclusion: Policy and Accommodation Practices in British Columbia's Secular School System

ERIC Educational Resources Information Center

Jacquet, Marianne; D'Amico, Laura

2016-01-01

The religious diversity of students and staff within a secular school system may sometimes create tensions. To better understand the possible issues generated by and practical accommodations made with respect to these tensions, interviews were conducted at the district level with key administrators in metropolitan school districts in British…

Human Values in a Secular World.

ERIC Educational Resources Information Center

Apostol, Robert Z.

The lectures of five contemporary philosophers, charged with addressing themselves to important moral issues of contemporary society with an eye to highlighting those values that are at the base of human life today, are presented in this volume. Louis Dupre is concerned with the issue of making religion intelligible in Religion in a Secular World.…

Teaching Morality and Religion in Nineteenth-Century Colonial Algeria: Gender and the Civilising Mission

ERIC Educational Resources Information Center

Rogers, Rebecca

2011-01-01

Historians have long presented France's "civilizing mission" within its colonies in secular terms ignoring women's presence as both actors and subjects. This is particularly true in Algeria where the colonial government's explicitly prohibited proselytism. This article emphasizes women's roles pursuing both secular and religious goals in…

The End of the Flynn Effect?

ERIC Educational Resources Information Center

Sundet, Jon Martin; Barlaug, Dag G.; Torjussen, Tore M.

2004-01-01

The present paper reports secular trends in the mean scores of a language, mathematics, and a Raven-like test together with a combined general ability (GA) score among Norwegian (male) conscripts tested from the mid 1950s to 2002 (birth cohorts approximately equal to 1935-1984). Secular gains in standing height (indicating improved nutrition and…

Secularism, Secularization, and John Dewey

ERIC Educational Resources Information Center

Hickman, Larry A.

2009-01-01

There seems to be an unwritten agreement among most Americans that there are three topics that are best avoided in polite company: (1) politics; (2) personal finances; and (3) religion. The American reluctance to discuss religion with acquaintances at a dinner party or picnic may be a part of a larger phenomenon: a manifestation of the secularism…

Secular, Singular and Self-Expression? Religious Freedom in Australian and New Zealand Education

ERIC Educational Resources Information Center

Varnham, Sally; Evers, Maxine

2009-01-01

Children today live in a multicultural society. Its ethnic, religious and cultural diversity is reflected in school communities. In Australia, education is provided largely within the secular public systems of each state and territory. In addition, there is a significant denominational, primarily Catholic, school sector. In New Zealand, the state…

Teaching about Religion in History Classes: Sacred and Secular History.

ERIC Educational Resources Information Center

Abrahamson, Brant; Smith, Fred

In teaching about religion there is the fundamental distinction between secular history, which is restricted to natural cause and effect relationships, and sacred histories, which assume that a spirit world exists and that human/divine interaction has taken place. In the United States, the academically approved way of dealing with these…

Secular Normativity and the "Religification" of Muslims in Swedish Public Schooling

ERIC Educational Resources Information Center

Berglund, Jenny

2017-01-01

This article suggests that the secular norms which influence much of the Swedish school system silence the voices and experiences of young Muslims who also attend Islamic supplementary education. It is based on interviews with 20 Muslim students in Sweden who reflected on their experiences of attending supplementary Islamic education in parallel…

The Relations between Islam and Secularism: The Impact on Social Behavior in Turkey

ERIC Educational Resources Information Center

Ismail, Nik Ahmad Hisham; Tekke, Mustafa

2016-01-01

Secularism as central to society and human life may bring undesired negative consequences in Muslim societies. Increasing social problems among juveniles in Turkey raised questions regarding the right personality development and education of young people. In extending further analysis, we conducted semi-structured interview with experts to assess…

Serendipity and Stewardship: Teaching with the Spirit in a Secular Classroom

ERIC Educational Resources Information Center

Hall, Bradford J.

2009-01-01

Can one appropriately teach with the spirit in a secular classroom? This chapter addresses the question by exploring how the concepts of serendipity and stewardship encourage a form of spirituality that is inclusive and appropriate for the university setting. Serendipity and stewardship work hand in hand. Stewardship resists the temptation of…

Groupies and Loners: The Population of Multi-planet Systems

NASA Astrophysics Data System (ADS)

Van Laerhoven, Christa L.; Greenberg, Richard

2014-11-01

Observational surveys with Kepler and other telescopes have shown that multi-planet systems are very numerous. Considering the secular dynamcis of multi-planet systems provides substantial insight into the interactions between planets in those systems. Since the underlying secular structure of a multi-planet system (the secular eigenmodes) can be calculated using only the planets' masses and semi-major axes, one can elucidate the eccentricity and inclination behavior of planets in those systems even without knowing the planets' current eccentricities and inclinations. We have calculated both the eccentricity and inclination secular eigenmodes for the population of known multi-planet systems whose planets have well determined masses and periods. We will discuss the commonality of dynamically grouped planets ('groupies') vs dynamically uncoupled planets ('loners'), and compare to what would be expected from randomly generated systems with the same overall distribution of masses and semi-major axes. We will also discuss the occurrence of planets that strongly influence the behavior of other planets without being influenced by those others ('overlords'). Examples will be given and general trends will be discussed.

Association between labour market trends and trends in young people's mental health in ten European countries 1983-2005.

PubMed

Lager, Anton C J; Bremberg, Sven G

2009-09-08

Mental health problems have become more common among young people over the last twenty years, especially in certain countries. The reasons for this have remained unclear. The hypothesis tested in this study is that national trends in young people's mental health are associated with national trends in young people's labour market. National secular changes in the proportion of young people with mental health problems and national secular labour market changes were studied from 1983 to 2005 in Austria, Belgium, Denmark, Finland, Hungary, Norway, Spain, Sweden, Switzerland and the United Kingdom. The correlation between the national secular changes in the proportion of young people not in the labour force and the national secular changes in proportion of young people with mental health symptoms was 0.77 for boys and 0.92 for girls. Labour market trends may have contributed to the deteriorating trend in mental health among young people. A true relationship, should other studies confirm it, would be an important aspect to take into account when forming labour market policies or policies concerning the delivery of higher education.

Secular Change in Morphological Pelvic Traits used for Sex Estimation.

PubMed

Klales, Alexandra R

2016-03-01

This research evaluates secular change in Phenice's (Am J Phys Anthropol, 30, 1969 and 297) three morphological traits of the pubis, as described by Klales et al. (Am J Phys Anthropol, 149, 2012 and 104): medial aspect of the ischio-pubic ramus, subpubic contour, and ventral arc. Ordinal scores were collected for these traits and compared between a sample of innominates from the historical Hamann-Todd Collection (n = 170) and modern Bass Donated Collection (n = 129). Using the Freeman-Halton test, significant differences between temporal sample score frequencies were found for all traits in females and for the subpubic contour and ventral arc in males. Despite these findings, classification accuracy using logistic regression between the temporal periods remained low (68.7%). These results suggest that secular changes in trait expression are occurring; however, sex estimation methods using these traits and created with historical samples are still applicable to modern forensic cases. In fact, the secular changes occurring in these traits contribute to better classification accuracy between sexes in modern populations. © 2015 American Academy of Forensic Sciences.

Analytical and numerical algorthms for revelation and investigation of secular resonances in the motion of near earth space objects. (Russian Title: Численно-аналитическая методика выявления и исследования вековых резонансов в движении околоземных объектов)

NASA Astrophysics Data System (ADS)

Bordovitsyna, T. V.; Tomilova, I. V.; Chuvashov, I. N.

2011-07-01

In this paper complex of analytical and numerical algorithms for revelation and investigation of secular resonances in the motion of near Earth space objects are presented. Analytical numerical algorithm for revelation secular resonances and numerical ones for study of object's long-time orbital evolution are applied. Small denominators are used as indicators of the secular resonances presence. The program complex "The numerical model of the motion of the Earth artificial satellite systems" are used for investigation of the orbital evolution.

A Current Application of the Methods of Secular and Statistical Parallax

NASA Astrophysics Data System (ADS)

Turner, D. G.

The methods of secular and statistical parallax for homogeneous groups of Galactic stars are applied in a practical (classroom) exercise to establish the luminosity of bright B3 V stars. The solar motion of 20 km s-1 relative to group stars exceeds their random velocities of ±10 km s-1, a condition adopted for preference of secular parallax to statistical parallax. The group parallax of πups = 5.81 ± 0.83 mas and derived luminosity MV = -0.98 ± 0.33 for B3 V stars from upsilon components of proper motion should be close to the true value. The weighted mean Hipparcos parallax of ±Hip = 5.75±0.27 mas for the same sample, and implied luminosity of MV = -1.00 ± 0.15, confirm the secular parallax solution. Both solutions are close to MV = -0.83 for ZAMS stars of the same type, implying that Malmquist bias in the selection of stars mainly accounts for the presence of unresolved binaries, slightly evolved objects, and rapidly rotating stars in the sample.

The commercialization of human body parts: a reappraisal from a Protestant perspective.

PubMed

Torcello, L; Wear, S

2000-08-01

The idea of a market in human organs has traditionally met with widespread and emphatic rejection from both secular and religious fronts alike. However, as numerous human beings continue to suffer an uncertain fate on transplant waiting lists, voices are beginning to emerge that are willing at least to explore the option of human organ sales. Anyone who argues for such a option must contend, however, with what seem to be largely emotional rejections of the idea. Often it seems that rebuffs offered on a secular ground are rooted in nothing more than vague discomforts. We suspect that these discomforts are often based in religious sentiments that have wound their way into the fabric of secular America. Therefore, in order to contribute further to those voices heard in favor of human organ sales, it is worthwhile to show that from a religious perspective, it is just as possible to affirm the appropriateness of human organ sales as it is from a secular basis. Since Protestantism has historically had a powerful influence in American society it is a proper starting point for such an investigation.

Exposure to science, perspectives on science and religion, and religious commitment in young adulthood.

PubMed

Uecker, Jeremy E; Longest, Kyle C

2017-07-01

Social scientists know very little about the consequences of exposure to scientific knowledge and holding different perspectives on science and religion for individuals' religious lives. Drawing on secularization and post-secular theories, we develop and test several hypotheses about the relationships among exposure to scientific knowledge, perspectives on religion and science, and religious commitment using panel data from the National Study of Youth and Religion. Our findings indicate that religious faith is strongest among young adults who: (1) accommodate scientific knowledge into their religious perspective, or (2) reject scientific knowledge that directly contradicts their religious beliefs about the origins of the world. Young adults are also more likely to have lower religious commitment when they view science and religion as independent institutions, lending support to secularization ideas about how social differentiation secularizes individuals. We further find that mere exposure to scientific knowledge, in terms of majoring in biology or acknowledging conflict between the teachings of religion and science, is usually not sufficient to undermine religious commitment. Copyright © 2017 Elsevier Inc. All rights reserved.

A modified homotopy perturbation method and the axial secular frequencies of a non-linear ion trap.

PubMed

Doroudi, Alireza

2012-01-01

In this paper, a modified version of the homotopy perturbation method, which has been applied to non-linear oscillations by V. Marinca, is used for calculation of axial secular frequencies of a non-linear ion trap with hexapole and octopole superpositions. The axial equation of ion motion in a rapidly oscillating field of an ion trap can be transformed to a Duffing-like equation. With only octopole superposition the resulted non-linear equation is symmetric; however, in the presence of hexapole and octopole superpositions, it is asymmetric. This modified homotopy perturbation method is used for solving the resulting non-linear equations. As a result, the ion secular frequencies as a function of non-linear field parameters are obtained. The calculated secular frequencies are compared with the results of the homotopy perturbation method and the exact results. With only hexapole superposition, the results of this paper and the homotopy perturbation method are the same and with hexapole and octopole superpositions, the results of this paper are much more closer to the exact results compared with the results of the homotopy perturbation method.

Secular trends of height, weight and BMI in young adult Brazilian military students in the 20th century.

PubMed

Avila, J A; Avila, R A; Gonçalves, E M; Barbeta, V J O; Morcillo, A M; Guerra-Junior, G

2013-01-01

Secular trends of increasing weight and height over past centuries are well documented in developed countries. However, these data are still scarce in developing countries such as Brazil. To verify the secular trends of height, weight and body mass index (BMI) of military students from Brazilian Army schools who were born between the 1920s and 1990s. A retrospective study was performed, which included a survey of data from the files of two Army schools. The sample was composed of subjects aged between 18-20 years old. The study analysed 2169 heights and 1741 weights and BMIs. During the evaluation period, height increased 7.3 cm, weight 9.8 kg and BMI 1.8 kg/m(2). The most significant gains were observed in subjects born from the 1920s to the 1940s and the 1960s to the 1970s. Secular trends of growth in military students born in the 20th century were positive in Brazil, although increases were not constant decade-by-decade.

The development of afterlife beliefs in religiously and secularly schooled children.

PubMed

Bering, Jesse M; Blasi, Carlos Hernández; Bjorklund, David F

2005-11-01

Children aged from 4;10 to 12;9 attending either a Catholic school or a public, secular school in an eastern Spanish city observed a puppet show in which a mouse was eaten by an alligator. Children were then asked questions about the dead mouse's biological and psychological functioning. The pattern of results generally replicated that obtained earlier in an American sample, with older children being more apt to state that functions cease after death than younger children (11- to 12-year-olds > 8- to 9-year-olds > 5- to 6-year-olds), and all children being more likely to attribute epistemic, desire, and emotion states to the dead mouse than biological, psychobiological, and perceptual states. Although children attending Catholic school were generally more likely to state that functions continue after death than children attending secular school, the pattern of change with regard to question type did not differ between the Catholic and secular groups. The results were interpreted as reflecting the combined roles of religious instruction/exposure and universal ontogeny of cognitive abilities on the development of children's afterlife beliefs. 2005 The British Psychological Society.

Secular Extragalactic Parallax and Geometric Distances with Gaia Proper Motions

NASA Astrophysics Data System (ADS)

Paine, Jennie; Darling, Jeremiah K.

2018-06-01

The motion of the Solar System with respect to the cosmic microwave background (CMB) rest frame creates a well measured dipole in the CMB, which corresponds to a linear solar velocity of about 78 AU/yr. This motion causes relatively nearby extragalactic objects to appear to move compared to more distant objects, an effect that can be measured in the proper motions of nearby galaxies. An object at 1 Mpc and perpendicular to the CMB apex will exhibit a secular parallax, observed as a proper motion, of 78 µas/yr. The relatively large peculiar motions of galaxies make the detection of secular parallax challenging for individual objects. Instead, a statistical parallax measurement can be made for a sample of objects with proper motions, where the global parallax signal is modeled as an E-mode dipole that diminishes linearly with distance. We present preliminary results of applying this model to a sample of nearby galaxies with Gaia proper motions to detect the statistical secular parallax signal. The statistical measurement can be used to calibrate the canonical cosmological “distance ladder.”

On the frequency spectra of the core magnetic field Gauss coefficients

NASA Astrophysics Data System (ADS)

Lesur, Vincent; Wardinski, Ingo; Baerenzung, Julien; Holschneider, Matthias

2018-03-01

From monthly mean observatory data spanning 1957-2014, geomagnetic field secular variation values were calculated by annual differences. Estimates of the spherical harmonic Gauss coefficients of the core field secular variation were then derived by applying a correlation based modelling. Finally, a Fourier transform was applied to the time series of the Gauss coefficients. This process led to reliable temporal spectra of the Gauss coefficients up to spherical harmonic degree 5 or 6, and down to periods as short as 1 or 2 years depending on the coefficient. We observed that a k-2 slope, where k is the frequency, is an acceptable approximation for these spectra, with possibly an exception for the dipole field. The monthly estimates of the core field secular variation at the observatory sites also show that large and rapid variations of the latter happen. This is an indication that geomagnetic jerks are frequent phenomena and that significant secular variation signals at short time scales - i.e. less than 2 years, could still be extracted from data to reveal an unexplored part of the core dynamics.

Molecular weights and metabolism of rat brain proteins

PubMed Central

Vrba, R.; Cannon, Wendy

1970-01-01

1. Rats were injected with [U-14C]glucose and after various intervals extracts of whole brain proteins (and in some cases proteins from liver, blood and heart) were prepared by high-speed centrifugation of homogenates in 0.9% sodium chloride or 0.5% sodium deoxycholate. 2. The extracts were subjected to gel filtration on columns of Sephadex G-200 equilibrated with 0.9% sodium chloride or 0.5% sodium deoxycholate. 3. Extracts prepared with both solvents displayed on gel filtration a continuous range of proteins of approximate molecular weights ranging from less than 2×104 to more than 8×105. 4. The relative amount of the large proteins (mol.wt.>8×105) was conspicuously higher in brain and liver than in blood. 5. At 15min after the injection of [U-14C]glucose the smaller protein molecules (mol.wt.<2×104) were significantly radioactive, whereas no 14C could be detected in the larger (mol.wt.>2×104) protein molecules. The labelling of all protein samples was similar within 4h after injection of [U-14C]glucose. Fractionation of brain proteins into distinctly different groups by the methods used in the present work yielded protein samples with a specific radioactivity comparable with that of total brain protein. 6. No evidence could be obtained by the methods used in the present and previous work to indicate the presence of a significant amount of `metabolically inert protein' in the brain. 7. It is concluded that: (a) most or all of the brain proteins are in a dynamic state of equilibrium between continuous catabolism and anabolism; (b) the continuous conversion of glucose into protein is an important part of the maintenance of this equilibrium and of the homoeostasis of brain proteins in vivo. PMID:5435499

Antarctic Rebound and the Time-Dependence of the Earth's Shape

NASA Technical Reports Server (NTRS)

Ivins, Erik R.; James, Thomas S.

2000-01-01

Great strides have been made during the past 30 years in refining models of the last global glaciation. The refinements draw upon a vastly expanded relative sea level and sedimentary core record. Furthermore, we now possess a sharpened understanding of the mechanisms that drive climate changes associated with deglaciation. Some 15 years ago, using only 5.5 years of ranging data, analyses of the drift in LAGEOS I node acceleration was used to infer that postglacial rebound was responsible for a secular change in the Earth's ellipsoidal shape (Yoder et al., .1983]. Today there exists a wealth of geodynamics satellite orbit data that constrain the secular time-dependence of the Earth's shape and low order gravity field, which includes mass redistribution from present-day glacier and great ice sheet imbalance and from postglacial rebound. We have shown that an unambiguous determination of the secular variation in the Earth's pear shaped harmonic (l = 3, m = 0) might provide information that bears on the present-day mass balance of Antarctica. This issue is revisited in light of new constraints on glacial loading during the late-Pleistocene and Holocene. An especially critical issue for the interpretation of secular odd degree zonal harmonics, l = 3 to 7, is the timing and magnitude of the deglaciation of Antarctica from Last Glacial Maximum. We explore ways in which the recovery of secular variation in both zonal and non-zonal harmonics for l = 2 through 7 can improve constraints on both rebound and present-day ice sheet balance.

Secular changes in Earth's shape and surface mass loading derived from combinations of reprocessed global GPS networks

NASA Astrophysics Data System (ADS)

Booker, David; Clarke, Peter J.; Lavallée, David A.

2014-09-01

The changing distribution of surface mass (oceans, atmospheric pressure, continental water storage, groundwater, lakes, snow and ice) causes detectable changes in the shape of the solid Earth, on time scales ranging from hours to millennia. Transient changes in the Earth's shape can, regardless of cause, be readily separated from steady secular variation in surface mass loading, but other secular changes due to plate tectonics and glacial isostatic adjustment (GIA) cannot. We estimate secular station velocities from almost 11 years of high quality combined GPS position solutions (GPS weeks 1,000-1,570) submitted as part of the first international global navigation satellite system service reprocessing campaign. Individual station velocities are estimated as a linear fit, paying careful attention to outliers and offsets. We remove a suite of a priori GIA models, each with an associated set of plate tectonic Euler vectors estimated by us; the latter are shown to be insensitive to the a priori GIA model. From the coordinate time series residuals after removing the GIA models and corresponding plate tectonic velocities, we use mass-conserving continental basis functions to estimate surface mass loading including the secular term. The different GIA models lead to significant differences in the estimates of loading in selected regions. Although our loading estimates are broadly comparable with independent estimates from other satellite missions, their range highlights the need for better, more robust GIA models that incorporate 3D Earth structure and accurately represent 3D surface displacements.

Secular Resonances During Main-Sequence and Post-Main-Sequence Planetary System Dynamics

NASA Astrophysics Data System (ADS)

Smallwood, Jeremy L.

We investigate gravitational perturbations of an asteroid belt by secular resonances. We ap- ply analytic and numerical models to main-sequence and post-main-sequence planetary systems. First, we investigate how the asteroid impact rate on the Earth is affected by the architecture of the planetary system. We find that the nu6 resonance plays an important role in the asteroid collision rate with the Earth. Compared to exoplanetary systems, the solar system is somewhat special in its lack of a super-Earth mass planet in the inner solar system. We therefore consider the effects of the presence of a super-Earth in the terrestrial planet region. We find a significant effect for super-Earths with a mass of around 10 M_{Earth} and a separation greater than about 0.7 AU. These results have implications for the habitability of exoplanetary systems. Secondly, we model white dwarf pollution by asteroids from secular resonances. In the past few decades, observations have revealed signatures of metals polluting the atmospheres of white dwarfs that require a continu- ous accretion of asteroids. We show that secular resonances driven by two outer companions can provide a source of pollution if an inner terrestrial planet is engulfed during the red-giant branch phase. Secular resonances may be a viable mechanism for the pollution of white dwarfs in a variety of exoplanetary system architectures including systems with two giant planets and systems with one giant planet and a binary star companion.

RESONANT POST-NEWTONIAN ECCENTRICITY EXCITATION IN HIERARCHICAL THREE-BODY SYSTEMS

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

Naoz, Smadar; Kocsis, Bence; Loeb, Abraham

2013-08-20

We study the secular, hierarchical three-body problem to first-order in a post-Newtonian expansion of general relativity (GR). We expand the first-order post-Newtonian Hamiltonian to leading-order in the ratio of the semi-major axis of the two orbits. In addition to the well-known terms that correspond to the GR precession of the inner and outer orbits, we find a new secular post-Newtonian interaction term that can affect the long-term evolution of the triple. We explore the parameter space for highly inclined and eccentric systems, where the Kozai-Lidov mechanism can produce large-amplitude oscillations in the eccentricities. The standard lore, i.e., that GR effectsmore » suppress eccentricity, is only consistent with the parts of phase space where the GR timescales are several orders of magnitude shorter than the secular Newtonian one. In other parts of phase space, however, post-Newtonian corrections combined with the three-body ones can excite eccentricities. In particular, for systems where the GR timescale is comparable to the secular Newtonian timescales, the three-body interactions give rise to a resonant-like eccentricity excitation. Furthermore, for triples with a comparable-mass inner binary, where the eccentric Kozai-Lidov mechanism is suppressed, post-Newtonian corrections can further increase the eccentricity and lead to orbital flips even when the timescale of the former is much longer than the timescale of the secular Kozai-Lidov quadrupole perturbations.« less

A candidate secular variation model for IGRF-12 based on Swarm data and inverse geodynamo modelling

NASA Astrophysics Data System (ADS)

Fournier, Alexandre; Aubert, Julien; Thébault, Erwan

2015-05-01

In the context of the 12th release of the international geomagnetic reference field (IGRF), we present the methodology we followed to design a candidate secular variation model for years 2015-2020. An initial geomagnetic field model centered around 2014.3 is first constructed, based on Swarm magnetic measurements, for both the main field and its instantaneous secular variation. This initial model is next fed to an inverse geodynamo modelling framework in order to specify, for epoch 2014.3, the initial condition for the integration of a three-dimensional numerical dynamo model. The initialization phase combines the information contained in the initial model with that coming from the numerical dynamo model, in the form of three-dimensional multivariate statistics built from a numerical dynamo run unconstrained by data. We study the performance of this novel approach over two recent 5-year long intervals, 2005-2010 and 2009-2014. For a forecast horizon of 5 years, shorter than the large-scale secular acceleration time scale (˜10 years), we find that it is safer to neglect the flow acceleration and to assume that the flow determined by the initialization is steady. This steady flow is used to advance the three-dimensional induction equation forward in time, with the benefit of estimating the effects of magnetic diffusion. The result of this deterministic integration between 2015.0 and 2020.0 yields our candidate average secular variation model for that time frame, which is thus centered on 2017.5.

Questioning Engelhardt's assumptions in Bioethics and Secular Humanism.

PubMed

Ahmadi Nasab Emran, Shahram

2016-06-01

In Bioethics and Secular Humanism: The Search for a Common Morality, Tristram Engelhardt examines various possibilities of finding common ground for moral discourse among people from different traditions and concludes their futility. In this paper I will argue that many of the assumptions on which Engelhardt bases his conclusion about the impossibility of a content-full secular bioethics are problematic. By starting with the notion of moral strangers, there is no possibility, by definition, for a content-full moral discourse among moral strangers. It means that there is circularity in starting the inquiry with a definition of moral strangers, which implies that they do not share enough moral background or commitment to an authority to allow for reaching a moral agreement, and concluding that content-full morality is impossible among moral strangers. I argue that assuming traditions as solid and immutable structures that insulate people across their boundaries is problematic. Another questionable assumption in Engelhardt's work is the idea that religious and philosophical traditions provide content-full moralities. As the cardinal assumption in Engelhardt's review of the various alternatives for a content-full moral discourse among moral strangers, I analyze his foundationalist account of moral reasoning and knowledge and indicate the possibility of other ways of moral knowledge, besides the foundationalist one. Then, I examine Engelhardt's view concerning the futility of attempts at justifying a content-full secular bioethics, and indicate how the assumptions have shaped Engelhardt's critique of the alternatives for the possibility of content-full secular bioethics.

Sharpening the U-Th Chronometer: Progress and Outlook

NASA Astrophysics Data System (ADS)

McLean, N. M.; Condon, D. J.; Henderson, G. M.; Richards, D. A.; Noble, S.; Mason, A.

2013-12-01

Uranium is incorporated into a variety of natural materials when they form, including carbonates like speleothems and corals. The two most abundant naturally occurring uranium isotopes, 238U and 235U, decay to 206Pb and 207Pb over long timescales with half-lives of 4.5 and 0.7 billion years respectively, but transition through several intermediate daughter isotopes with shorter half-lives first. Fractionation between these daughter isotopes, including 234U, 230Th, and 231Pa, and their parent isotopes, followed by their time-dependent return to secular equilibrium over the course of up to ~800 kyr, forms the basis for U-series geochronology, and allows speleothems and corals to be precisely dated. These carbonates often additionally incorporate chemical and isotopic signatures (e.g., trace elements, δ18O and δ13C) from the environment in which they form, and thus are some of the best dated paleoclimate archives, offering clues about past and future conditions for life on Earth. Over the past decade, the analytical precision of U-series isotope measurements has improved dramatically, largely due to the steadily increasing sensitivity of multiple-collector inductively coupled plasma mass spectrometry (MC-ICP-MS). Analytical uncertainties in U-Th dates now approach or are better than 0.1% (2σ), for instance ×100 years for a speleothem or coral that is 130 kyr old (Cheng et al., 2013). However, the accuracy of U-series dates also depends on the accuracy of tracer calibrations, reference solutions and data reduction protocols, which has not kept pace in many laboratories. This means that dates measured in different labs, while impressively precise, may not be directly comparable. To address issues of inter-laboratory bias and improve the accuracy and inter-comparability of U-Th dates, we have instigated work in three related directions. First, we report on the mixing of three synthetic U-Th age solutions, created by combining high-purity mono-isotopic solutions to mimic the isotopic composition of commonly analyzed materials. These age solutions will form the basis for an inter-laboratory comparison and serve as international reference materials for assessing long-term reproducibility. Second is the creation of several U-Th gravimetric solutions, which can be used to calibrate the mixed 229Th-236U×233U tracers used in the community without having to rely on materials assumed to be in secular equilibrium. Tracers calibrated against these solutions, and therefore U-Th dates measured with these tracers, will be fully metrologically traceable. Finally, we report progress on and important considerations in developing data reduction and uncertainty propagation protocols for calculating U-Th dates and constructing and interpreting U-Th age models. Reference: Cheng et al. (2013) EPSL 371-372, 82-91

Geomagnetic acceleration and rapid hydromagnetic wave dynamics in advanced numerical simulations of the geodynamo

NASA Astrophysics Data System (ADS)

Aubert, Julien

2018-04-01

Geomagnetic secular acceleration, the second temporal derivative of Earth's magnetic field, is a unique window on the dynamics taking place in Earth's core. In this study, the behaviours of the secular acceleration and underlying core dynamics are examined in new numerical simulations of the geodynamo that are dynamically closer to Earth's core conditions than earlier models. These new models reside on a theoretical path in parameter space connecting the region where most classical models are found to the natural conditions. The typical time scale for geomagnetic acceleration is found to be invariant along this path, at a value close to 10 years that matches Earth's core estimates. Despite this invariance, the spatio-temporal properties of secular acceleration show significant variability along the path, with an asymptotic regime of rapid rotation reached after 30% of this path (corresponding to a model Ekman number E = 3 - 7). In this regime, the energy of secular acceleration is entirely found at periods longer than that of planetary rotation, and the underlying flow acceleration patterns acquire a two-dimensional columnar structure representative of the rapid rotation limit. The spatial pattern of the secular acceleration at the core-mantle boundary shows significant localisation of energy within an equatorial belt. Rapid hydromagnetic wave dynamics is absent at the start of the path because of insufficient time scale separation with convective processes, weak forcing and excessive damping but can be clearly exhibited in the asymptotic regime. This study reports on ubiquitous axisymmetric geostrophic torsional waves of weak amplitude relatively to convective transport, and also stronger, laterally limited, quasi-geostrophic Alfvén waves propagating in the cylindrical radial direction from the tip of convective plumes towards the core-mantle boundary. In a system similar to Earth's core where the typical Alfvén velocity is significantly larger than the typical convective velocity, quasi-geostrophic Alfvén waves are shown to be an important carrier of flow acceleration to the core surface that links with the generation of strong, short-lived and intermittent equatorial pulses in the secular acceleration energy. The secular acceleration time scale is shown to be insensitive to magnetic signatures from torsional waves because of their weak amplitude, and from quasi-geostrophic Alfvén waves because of their intermittent character, and is therefore only indicative of convective transport phenomena that remain invariant along the parameter space path.

Religious, Secular, and Spiritual Identities Convergence: Introduction to the Special Issue

ERIC Educational Resources Information Center

Small, Jenny L.; Bowman, Nicholas A.

2018-01-01

The purpose of this special issue is to share the best research, theory, practice, and perspectives from presenters at the 2017 Religious, Secular, and Spiritual Identities Convergence conference, alongside the new writing of scholars and practitioners who were inspired by the themes of the conference. Readers will have access both to the best of…

On Tour with the "Accidental" Expert: Ethical Dilemmas of the Development Consultant.

ERIC Educational Resources Information Center

Basile, Michael L.

This paper explores Max Weber's study of the origins of the secularization of the Puritan work ethic and examines the hybridized category of secular science expert. The hybrid construct provides an opening for the critical analysis of the concrete activity of development from two perspectives, the structural and the individual. The individual…

The Urgent Need for Teacher Preparation in Religious and Secular Worldview Education

ERIC Educational Resources Information Center

Gardner, Ryan S.; Soules, Kate; Valk, John

2017-01-01

In a world that is becoming increasingly globalized, it is ironic--as well as unfortunate and sometimes tragic--that secular and religious worldview education is decreasing, in the United States, Canada, and elsewhere. This article argues for the immediate need for programs that intentionally prepare teachers for all aspects of the educational…

Parental Expectations of Teachers in a Private School.

ERIC Educational Resources Information Center

Kapel, David E.; Kapel, Marilyn B.

A survey was made of parental expectations of secular and religious teachers at a Jewish day school in a large metropolitan area located in the Ohio Valley. The school, with a student population of 108 students, employs 6 secular and 4 religious teachers. A high response rate (61 percent) was received from the parents. Findings indicated that…

Christian Faith and Scholarship: An Exploration of Contemporary Developments. ASHE Higher Education Report, Volume 33, Number 2

ERIC Educational Resources Information Center

Ream, Todd C., Ed.; Glanzer, Perry L., Ed.

2007-01-01

This monograph offers an overview of the various ways conversations about religion and religiously informed scholarship are increasing among scholars in secular and church-related colleges and universities. Specifically, it addresses the history of secularization in American higher education and scholarship, the general models of faith and…

An Analysis of the Strategic Planning Efforts of (Arch)Dioceses with Similar Demographic Conditions

ERIC Educational Resources Information Center

Semmler, Carl A.

2016-01-01

The population of the Catholic elementary schools has been on the downward trend for over half a century. Various Catholic (arch)dioceses have responded by creating strategic plans for their elementary and secondary institutions of education. Shifts in demographics and population migration have been noted in both secular and non-secular data.…

Un/Covering: Female Religious Converts Learning the Problems and Pragmatics of Physical Observance in the Secular World

ERIC Educational Resources Information Center

Galman, Sally Campbell

2013-01-01

This article presents the experiences of three women who have chosen to move from secular, assimilated lives to lives characterized by the distinctive dress and practice associated with observant Islam, Orthodox Judaism, and Orthodox Christianity, respectively. All three relied upon informal, peer, and distance learning strategies for their…

The Phenomenon of Becoming Religious among Secular Pupils at High Schools in Israel

ERIC Educational Resources Information Center

Zamir, Sara

2017-01-01

The phenomenon of adopting a religious lifestyle is growing worldwide in general and in Israel in particular. In the Israeli context, the transition from a secular lifestyle to a religious one is defined as "repentance". Sociologists define the repentant as someone who has changed his or her beliefs, opinions and behaviours in the…

Islamization or Secularization? Educational Reform and the Search for Peace in the Southern Philippines

ERIC Educational Resources Information Center

Milligan, Jeffrey Ayala

2004-01-01

Since 2001 many observers of education in the Muslim world have expressed concerns about the radicalizing influence of madrasahs. These critiques often assume that the ichotomization of sacred and secular common to civic society in the West is a necessary ingredient of any educational reforms designed to prevent the spread of religious extremism…

The Full-Time Workweek in the United States, 1900-1970

ERIC Educational Resources Information Center

Kniesner, Thomas J.

1976-01-01

The average workweek of full-time workers declined by 35 percent between 1900 and 1940, but has not changed significnatly since then, and the secular rigidity of the full-time workweek remains. An expanded model which incorporates the effects of growth in education and in the female wage explains the post-1940 secular trend. (Editor/HD)

Psychological Science and Religious Education in a Devout University: The Case of Pain Overlap Theory and the Talmud

ERIC Educational Resources Information Center

Schnall, Eliezer

2014-01-01

Educators employed in devoutly religious institutions often teach students who view even their secular higher education through a uniquely religious lens. Based on his own experiences teaching psychological science at a Jewish university, the author suggests enhancing student interest and enthusiasm by wedding secular curricula with religious…

Does Individual Secularism Promote Life Satisfaction? The Moderating Role of Societal Development

ERIC Educational Resources Information Center

Li, Liman Man Wai; Bond, Michael H.

2010-01-01

This study was designed to examine the link between values and life satisfaction, examining the role of culture in this process. Secularism was found to predict life satisfaction scores at a small but statistically very significant level in persons from all nations participating in all four waves of the World Values Survey. The direction and…

The European Court of Human Rights, Secular Education and Public Schooling

ERIC Educational Resources Information Center

Arthur, James; Holdsworth, Michael

2012-01-01

Since 9/11 the European Court of Human Rights (the European Court) has raised anew the question of the relationship between religion and public education. In its reasoning, the European Court has had to consider competing normative accounts of the secular, either to accept or deny claims to religious liberty within Europe's public education…

Science education in a secular age

NASA Astrophysics Data System (ADS)

Long, David E.

2013-03-01

A college science education instructor tells his students he rejects evolution. What should we think? The scene unfolds in one of the largest urban centers in the world. If we are surprised, why? Expanding on Federica Raia's (2012) first-hand experience with this scenario, I broaden her discussion by considering the complexity of science education in a secular age. Enjoining Raia within the framework of Charles Taylor's A Secular Age, I task the science education community to consider the broad strokes of science, religious faith, and the complexity of modernity in its evolving, hybridized forms. Building upon anthropological approaches to science education research, I articulate a framework to more fully account for who, globally, is a Creationist, and what this means for our views of ethically responsive science education.

A Statistical Model of the Fluctuations in the Geomagnetic Field from Paleosecular Variation to Reversal

PubMed

Camps; Prevot

1996-08-09

The statistical characteristics of the local magnetic field of Earth during paleosecular variation, excursions, and reversals are described on the basis of a database that gathers the cleaned mean direction and average remanent intensity of 2741 lava flows that have erupted over the last 20 million years. A model consisting of a normally distributed axial dipole component plus an independent isotropic set of vectors with a Maxwellian distribution that simulates secular variation fits the range of geomagnetic fluctuations, in terms of both direction and intensity. This result suggests that the magnitude of secular variation vectors is independent of the magnitude of Earth's axial dipole moment and that the amplitude of secular variation is unchanged during reversals.

Ultra-Sensitive Elemental Analysis Using Plasmas 4.Application of Inductively Coupled Plasma Mass Spectrometry to the Study of Environmental Radioactivity

NASA Astrophysics Data System (ADS)

Yoshida, Satoshi

Applications of inductively coupled plasma mass spectrometry (ICP-MS) to the determination of long-lived radionuclides in environmental samples were summarized. In order to predict the long-term behavior of the radionuclides, related stable elements were also determined. Compared with radioactivity measurements, the ICP-MS method has advantages in terms of its simple analytical procedures, prompt measurement time, and capability of determining the isotope ratio such as240Pu/239Pu, which can not be separated by radiation. Concentration of U and Th in Japanese surface soils were determined in order to determine the background level of the natural radionuclides. The 235U/238U ratio was successfully used to detect the release of enriched U from reconversion facilities to the environment and to understand the source term. The 240Pu/239Pu ratios in environmental samples varied widely depending on the Pu sources. Applications of ICP-MS to the measurement of I and Tc isotopes were also described. The ratio between radiocesium and stable Cs is useful for judging the equilibrium of deposited radiocesium in a forest ecosystem.

Cancer survivors' understanding of the cause and cure of their illness: Religious and secular appraisals.

PubMed

Carney, Lauren M; Park, Crystal L

2018-02-28

Little is known about survivors' understanding of the cause of their cancer and of their recovery, nor how these ways of understanding relate to their well-being. No study has examined both secular and religious appraisals of the same event. The current study aimed to examine both religious (God) and secular (self) appraisals of both the cause (attributions) and course/cure of cancer in relation to multiple aspects of adjustment. Data were obtained from a sample of cancer survivors at Time 1 (n = 250) and 1 year later (Time 2, n = 167). Cancer survivors endorsed higher appraisals relating to course/cure of their cancer than those relating to cause, and they endorsed both secular and religious appraisals. Appraisals of the cause and course/cure of cancer were differentially related to adjustment, such that self-attributions of cause and God-attributions of cause were related to negative aspects of adjustment (eg, negative affect and pessimism), while appraisals of self and God's control over the course/cure were related to positive aspects of adjustment (eg, perceived positive life and health changes since cancer). Religiosity did not moderate most of relationships between religious appraisals and adjustment outcomes. Secular and religious appraisals of cancer are not mutually exclusive, and religious appraisals are associated with adjustment regardless of survivors' religiosity. Appraisals relating to cause and course/cure have differential relationships with well-being. Addressing cancer survivors' appraisals-religious or nonreligious-in a therapeutic setting may be beneficial regardless of their reported religiosity. Copyright © 2018 John Wiley & Sons, Ltd.

More on the alleged 1970 geomagnetic jerk

USGS Publications Warehouse

Alldredge, L.R.

1985-01-01

French and United Kingdom workers have published reports describing a sudden change in the secular acceleration, called an impulse or a jerk, which took place around 1970. They claim that this change took place in a period of a year or two and that the sources of the alleged jerk are internal. An earlier paper by this author questioned their method of analysis pointing out that their method of piecemeal fitting of parabolas to the data will always create a discontinuity in the secular acceleration where the parabolas join and that the place where the parabolas join is an a priori assumption and not a result of the analysis. This paper gives a very brief summary of this first paper and then adds additional reasons for questioning the allegation that there was a worldwide sudden jerk in the magnetic field of internal origin around 1970. These new reasons are based largely on new field models which give cubic approximations of the field right through the 1970 timeframe and therefore have no discontinuities in the second derivative (jerk) around 1970. Some recent Japanese work shows several sudden changes in the secular variation pattern which cover limited areas and do not seem to be closely related to each other or to the irregularity noted in the European area near 1970. The secular variation picture which seems to be emerging is one with many local or limited-regional secular variation changes which appear to be almost unrelated to each other in time or space. A worldwide spherical harmonic model including coefficients up to degree 13 could never properly depict such a situation. ?? 1985.

Transforming Faith: Teaching as a Christian Vocation in a Secular, Worldview-Diverse Culture

ERIC Educational Resources Information Center

Cooling, Trevor

2010-01-01

This article advocates the thesis that Christian teachers can and should draw on the resources of their faith in their work of leading teaching and learning. The secular approach where faith is treated as a private matter and the "market share" approach where the dominance of Christian faith is sought, are both rejected. A third way which aspires…

The Mediating Role of Secular Coping Strategies in the Relationship between Religious Appraisals and Adjustment to Chronic Pain: The Middle Road to Damascus

ERIC Educational Resources Information Center

Parenteau, Stacy C.; Hamilton, Nancy A.; Wu, Wei; Latinis, Kevin; Waxenberg, Lori B.; Brinkmeyer, Mary Y.

2011-01-01

Despite an outgrowth in research examining associations between religiosity and health outcomes, there has been a lack of empirical focus on the relationship between religiosity and adjustment to chronic pain. This study investigated specific secular coping strategies that mediate the proposed relationship between religious appraisals and…

Strategic Implications of American Millennialism

DTIC Science & Technology

2008-05-22

religious and secular philosophies.11 Secular considerations notwithstanding, the single most important factor in western apocalypticism are the Bible ...specifically the books of Daniel and Revelation. In the Bible and subsequent philosophical interpretations, we can trace the source of our linear...in large part from extraordinary literalism of even the most figurative passages of the Bible . In America, literalism in biblical interpretation is

The Development of Afterlife Beliefs in Religiously and Secularly Schooled Children

ERIC Educational Resources Information Center

Bering, Jesse M.; Blasi, Carlos Hernandez; Bjorklund, David F.

2005-01-01

Children aged from 4;10 to 12;9 attending either a Catholic school or a public, secular school in an eastern Spanish city observed a puppet show in which a mouse was eaten by an alligator. Children were then asked questions about the dead mouse's biological and psychological functioning. The pattern of results generally replicated that obtained…

Hizb ut-Tahrir: A Threat Behind a Legal Facade?

DTIC Science & Technology

2006-06-01

as something “man-made,’ humanly derived and “un-Islamic,” and therefore, does not participate in any secular electoral process . However, HT does...derived and “un-Islamic,” and therefore, does not participate in any secular electoral process . However, HT does not reject modern technology and its...2. The Evolutionary Process of Jihad Interpretations ..........................................62 x

On orbital period changes of two low-mass-ratio and deep-contact binaries: FN Cam and KN Per

NASA Astrophysics Data System (ADS)

Hu, Ke; Jiang, Zhen-Hua; Yu, Yun-Xia; Xiang, Fu-Yuan

2018-07-01

The orbital period changes of two low-mass-ratio and deep-contact binaries, FN Cam and KN Per, are investigated by using all available times of light minimum taken from the databases and literature. It is found that the orbital periods of FN Cam and KN Per show secular increase at a rate of P˙ = 4.38 ×10-7 days year-1 and P˙ = 4.18 ×10-7 days year-1 , respectively. The secular period increase suggests that FN Cam and KN Per are undergoing continuous mass transfer from the less massive secondary component to the more massive primary one. A statistical analysis of 53 low-mass-ratio and deep-contact binaries indicates that all of them should contain at least a continuous period change (secular increase/decrease or cyclic oscillation). Moreover, the rates of the secular period variations can be at a common level of P˙ ∼10-7 days year-1. In addition, the cyclic period oscillation has been detected for only 43% of sample stars, which indicates that it should be not popular for all low-mass-ratio and deep-contact binaries.

A Spiritually-based approach to breast cancer awareness: Cognitive response analysis of communication effectiveness

PubMed Central

Holt, Cheryl L.; Lee, Crystal; Wright, Katrina

2017-01-01

The purpose of this study was to compare the communication effectiveness of a spiritually-based approach to breast cancer early detection education with a secular approach, among African American women, by conducting a cognitive response analysis. A total of 108 women from six Alabama churches were randomly assigned by church to receive a spiritually-based or secular educational booklet discussing breast cancer early detection. Based on the Elaboration Likelihood Model (Petty & Cacioppo, 1981), after reading the booklets participants were asked to complete a thought-listing task writing down any thoughts they experienced and rating them as positive, negative, or neutral. Two independent coders then used five dimensions to code participants thoughts. Compared with the secular booklet, the spiritually-based booklet resulted in significantly more thoughts involving personal connection, self-assessment, and spiritually-based responses. These results suggest that a spiritually-based approach to breast cancer awareness may be more effective than the secular because it caused women to more actively process the message, stimulating central route processing. The incorporation of spiritually-based content into church-based breast cancer education could be a promising health communication approach for African American women. PMID:18443989

When Science Replaces Religion: Science as a Secular Authority Bolsters Moral Sensitivity

PubMed Central

2015-01-01

Scientific and religious thinking compete with each other on several levels. For example, activating one generally weakens the other. Since priming religion is known to increase moral behaviour and moral sensitivity, priming science might be expected to have the opposite effect. However, it was recently demonstrated that, on the contrary, science priming increases moral sensitivity as well. The present set of studies sought to replicate this effect and test two explanations for it. Study 1 used a sentence unscrambling task for implicitly priming the concept of science but failed to replicate its effect on moral sensitivity, presumably due to a ceiling effect. Study 2 replicated the effect with a new measure of moral sensitivity. Study 3 tested whether science-related words create this effect by activating the idea of secular authority or by activating analytic thinking. It was demonstrated that words related to secular authority, but not words related to analytic thinking, produced a similar increase in moral sensitivity. Religiosity level of the participants did not influence this basic finding. The results are consistent with the hypothesis that science as a secular institution has overtaken some of the functions of religion in modern societies. PMID:26360826

When Science Replaces Religion: Science as a Secular Authority Bolsters Moral Sensitivity.

PubMed

Yilmaz, Onurcan; Bahçekapili, Hasan G

2015-01-01

Scientific and religious thinking compete with each other on several levels. For example, activating one generally weakens the other. Since priming religion is known to increase moral behaviour and moral sensitivity, priming science might be expected to have the opposite effect. However, it was recently demonstrated that, on the contrary, science priming increases moral sensitivity as well. The present set of studies sought to replicate this effect and test two explanations for it. Study 1 used a sentence unscrambling task for implicitly priming the concept of science but failed to replicate its effect on moral sensitivity, presumably due to a ceiling effect. Study 2 replicated the effect with a new measure of moral sensitivity. Study 3 tested whether science-related words create this effect by activating the idea of secular authority or by activating analytic thinking. It was demonstrated that words related to secular authority, but not words related to analytic thinking, produced a similar increase in moral sensitivity. Religiosity level of the participants did not influence this basic finding. The results are consistent with the hypothesis that science as a secular institution has overtaken some of the functions of religion in modern societies.

American medicine as religious practice: care of the sick as a sacred obligation and the unholy descent into secularization.

PubMed

Wardlaw, Margaret P

2011-03-01

Modern medicine serves a religious function for modern Americans as a conduit through which science can be applied directly to the human body. The first half of this paper will focus on the theoretical foundations for viewing medicine as a religious practice arguing that just as a hierarchical structured authoritarian church historically mediated access to God, contemporary Western medicine provides a conduit by which the universalizable truths of science can be applied to the human being thereby functioning as a new established religion. I will then illustrate the many parallels between medicine and religion through an analysis of rituals and symbols surrounding and embedded within the modern practice of medicine. This analysis will pay special attention to the primacy placed on secret interior knowledge of the human body. I will end by responding to the hope for a "secularization of American medicine," exploring some of the negative consequences of secularization, and arguing that, rather than seeking to secularize, American medicine should strive to use its religious features to offer hope and healing to the sick, in keeping with its historically religious legacy.

Moderating Effects of Religiousness and Marriage Duration on the Relation Between Sexual and Marital Satisfaction Among Jewish Women.

PubMed

Lazar, Aryeh

2017-02-01

This study examined the moderating effects of religiousness and relationship duration on the association between sexual and marital satisfaction. For this purpose, 240 married Jewish women-religious and secular-responded to an online survey. Hierarchical regression analysis indicated that religiousness moderated the association between sexual and marital satisfaction which was found to be stronger for secular women than for religious women. Relationship duration also moderated the association between sexual and marital satisfaction which was found to be stronger for longer marital duration than for shorter marital duration. In addition, a significant three-way interaction (religiousness × relationship duration × sexual satisfaction) was also found where the association between the two types of satisfaction was stronger for religious women married for a longer time in comparison with those married for a shorter time. For secular women, relationship duration did not moderate the relation between sexual and marital satisfaction. An explanation based on differences in the manner in which religious and secular women perceive and relate to the sexual aspects of their marital relationship at different stages of the marriage is offered.

New methods for deriving cometary secular light curves: C/1995 O1 (Hale-Bopp) revisited

NASA Astrophysics Data System (ADS)

Womack, Maria; Lastra, Nathan; Harrington, Olga; Curtis, Anthony; Wierzchos, Kacper; Ruffini, Nicholas; Charles, Mentzer; Rabson, David; Cox, Timothy; Rivera, Isabel; Micciche, Anthony

2017-10-01

We present an algorithm for reducing scatter and increasing precision in a comet light curve. As a demonstration, we processed apparent magnitudes of comet Hale-Bopp from 16 highly experienced observers (archived with the International Comet Quarterly), correcting for distance from Earth and phase angle. Different observers tend to agree on the difference in magnitudes of an object at different distances, but the magnitude reported by observer is shifted relative to that of another for an object at a fixed distance. We estimated the shifts using a self-consistent statistical approach, leading to a sharper light curve and improving the precision of the measured slopes. The final secular lightcurve for comet Hale-Bopp ranges from -7 au (pre-perihelion) to +8 au (post-perihelion) and is the best secular light curve produced to date for this “great” comet. We discuss Hale-Bopp’s lightcurve evolution and possibly related physical implications, and potential usefulness of this light curve for comparisons with other future bright comets. We also assess the appropriateness of using secular lightcurves to characterize dust production rates in Hale-Bopp and other dust-rich comets. M.W. acknowledges support from NSF grant AST-1615917.

Religiousness and Religious Coping in a Secular Society: The Gender Perspective

PubMed Central

Hvidtjørn, Dorte; Hjelmborg, Jacob; Skytthe, Axel; Christensen, Kaare; Hvidt, Niels Christian

2014-01-01

Women are found to be more religious than men and more likely to use religious coping. Only few studies have explored religious gender differences in more secular societies. This population-based study comprised 3,000 Danish men and women (response rate 45 %) between 20 and 40 years of age. Information about demographics, religiousness and religious coping was obtained through a web-based questionnaire. We organized religiousness in the three dimensions: Cognition, Practice and Importance, and we assessed religious coping using the brief RCOPE questionnaire. We found substantial gender differences in both religiousness and religious coping. Nearly, 60 % of the women believed in some sort of spirit or in God compared to 40 % of the men. Generally, both men and women scored low on the RCOPE scale. However, for respondents reporting high levels of religiousness, the proportion of men who scored high in the RCOPE exceeded the proportion of women in using positive and especially negative coping strategies. Also, in a secular society, women are found to be more religious than men, but in a subset of the most religious respondents, men were more inclined to use religious coping. Further studies on religious coping in secular societies are required. PMID:23625173

Religiousness and religious coping in a secular society: the gender perspective.

PubMed

Hvidtjørn, Dorte; Hjelmborg, Jacob; Skytthe, Axel; Christensen, Kaare; Hvidt, Niels Christian

2014-10-01

Women are found to be more religious than men and more likely to use religious coping. Only few studies have explored religious gender differences in more secular societies. This population-based study comprised 3,000 Danish men and women (response rate 45 %) between 20 and 40 years of age. Information about demographics, religiousness and religious coping was obtained through a web-based questionnaire. We organized religiousness in the three dimensions: Cognition, Practice and Importance, and we assessed religious coping using the brief RCOPE questionnaire. We found substantial gender differences in both religiousness and religious coping. Nearly, 60 % of the women believed in some sort of spirit or in God compared to 40 % of the men. Generally, both men and women scored low on the RCOPE scale. However, for respondents reporting high levels of religiousness, the proportion of men who scored high in the RCOPE exceeded the proportion of women in using positive and especially negative coping strategies. Also, in a secular society, women are found to be more religious than men, but in a subset of the most religious respondents, men were more inclined to use religious coping. Further studies on religious coping in secular societies are required.

Serratia sp. ZF03: an efficient radium biosorbent isolated from hot-spring waters in high background radiation areas.

PubMed

Zakeri, Farideh; Noghabi, Kambiz Akbari; Sadeghizadeh, Majid; Kardan, Mohammad Reza; Masoomi, Fatemeh; Farshidpour, Mohammad Reza; Atarilar, Ali

2010-12-01

The aim of this study is to isolate and characterize (226)Ra biosorbing indigenous bacterial strains from soils and hot-springs containing high concentrations of (226)Ra by using biochemical and molecular approaches. Fifteen bacteria were isolated and their phylogenetic affiliations were determined based on their 16S rRNA gene and the two most relevant hypervariable regions of this gene; V3 and V6 analysis. A pigmented Serratia sp. ZF03 strain isolated from the water with (226)Ra content of 50471 mBq l(-1), caused 70% removal of (226)Ra at a radioactivity level of 50 Bq ml(-1), after 5 min and 75-80% in equilibrium time of 1 h, depending on the particular biosorption system and experimental conditions studied. The biosorption equilibrium was described by Langmuir and Freundlich isotherm models. Kinetic studies indicated that the biosorption follows pseudo-second-order kinetics. Effect of different physico-chemical parameters on (226)Ra sorption, FTIR, SEM and TEM analysis were also investigated. 2010 Elsevier Ltd. All rights reserved.

Radon and ammonia transects across the Cerro Prieto geothermal field

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

Semprini, L.; Kruger, P.

1981-01-01

Radon and ammonia transects, conducted at the Cerro Prieto geothermal field, involve measurement of concentration gradients at wells along lines of structural significance in the reservoir. Analysis of four transects showed radon concentrations ranging from 0.20 to 3.60 nCi/kg and ammonia concentrations from 17.6 to 59.3 mg/l. The data showed the lower concentrations in wells of lowest enthalpy fluid and the higher concentrations in wells of highest enthalpy fluid. Linear correlation analysis of the radon-enthalpy data indicated a strong relationship, with a marked influence by the two-phase conditions of the produced fluid. It appears that after phase separation in themore » reservoir, radon achieves radioactive equilibrium between fluid and rock, suggesting that the phase separation occurs well within the reservoir. A two-phase mixing model based on radon-enthalpy relations allows estimation of the fluid phase temperatures in the reservoir. Correlations of ammonia concentration with fluid enthalpy suggests an equilibrium partitioning model in which enrichment of ammonia correlates with higher enthalpy vapor.« less

The role of religious faith, spirituality and existential considerations among heart patients in a secular society: relation to depressive symptoms 6 months post acute coronary syndrome.

PubMed

Bekke-Hansen, Sidsel; Pedersen, Christina G; Thygesen, Kristian; Christensen, Søren; Waelde, Lynn C; Zachariae, Robert

2014-06-01

We explored the significance of religious faith/coping and spirituality and existential considerations reported during hospitalisation on depressive symptoms at 6-month follow-up and addressed patients' perceived influence of their faith among 97 consecutive acute coronary syndrome patients (72.2% male patients; mean age, 60.6 years) in a secular society. All faith variables were found unrelated to depressive symptoms. Having unambiguous religious or spiritual faith at follow-up was associated with a perceived positive influence of this faith on quality of life and the disease itself compared to patients with ambiguous faith. These findings underscore the importance of examining degrees of faith in secular settings. © The Author(s) 2013.

Seasonal cycle and secular trend of the total and tropospheric column abundance of ethane above the Jungfraujoch

NASA Technical Reports Server (NTRS)

Ehhalt, D. H.; Schmidt, U.; Zander, R.; Demoulin, P.; Rinsland, C. P.

1991-01-01

The secular trend and the seasonal cycle of the total and the tropospheric column abundances of C2H6 over the Jungfraujoch Station (Switzerland) were deduced from infrared solar spectra recorded in 1951 and from 1984 to 1988. Results show a definite seasonal variation in the total vertical column abundance of C2H6, with a maximum of (1.43 + or - 0.03) x 10 to the 16th molecules/sq cm during March and April and a minimum in the fall; the ratio between the maximum and the minimum column abundances was found to be 1.62 + or - 0.11. The secular trend in the tropospheric burden above the Jungfraujoch was found to be (0.85 + or - 0.3) percent/yr.

Bar-spheroid interaction in galaxies

NASA Technical Reports Server (NTRS)

Hernquist, Lars; Weinberg, Martin D.

1992-01-01

N-body simulation and linear analysis is employed to investigate the secular evolution of barred galaxies, with emphasis on the interaction between bars and spheroidal components of galaxies. This interaction is argued to drive secular transfer of angular momentum from bars to spheroids, primarily through resonant coupling. A moderately strong bar, having mass within corotation about 0.3 times the enclosed spheroid mass, is predicted to shed all its angular momentum typically in less than about 10 exp 9 yr. Even shorter depletion time scales are found for relatively more massive bars. It is suggested either that spheroids around barred galaxies are structured so as to inhibit strong coupling with bars, or that bars can form by unknown processes long after disks are established. The present models reinforce the notion that bars can drive secular evolution in galaxies.

Transit Duration Variations due to Secular Interactions in Systems with Tightly-packed Inner Planets

NASA Astrophysics Data System (ADS)

Boley, Aaron; Van Laerhoven, Christa; Granados Contreras, A. Paula

2018-04-01

Secular interactions among planets in multi-planet systems will lead to variations in orbital inclinations and to the precession of orbital nodes. Taking known system architectures at face value, we calculate orbital precession rates for planets in tightly-packed systems using classical second-order secular theory, in which the orientation of the orbits can be described as a vector sum of eigenmodes and the eigenstructure is determined only by the masses and semi-major axes of the planets. Using this framework, we identify systems that have fast precession frequencies, and use those systems to explore the range of transit duration variation that could occur using amplitudes that are consistent with tightly-packed planetary systems. We then further assess how transit duration variations could be used in practice.

Geomagnetic temporal change: 1903-1982 - A spline representation

NASA Technical Reports Server (NTRS)

Langel, R. A.; Kerridge, D. J.; Barraclough, D. R.; Malin, S. R. C.

1986-01-01

The secular variation of the earth's magnetic field is itself subject to temporal variations. These are investigated with the aid of the coefficients of a series of spherical harmonic models of secular variation deduced from data for the interval 1903-1982 from the worldwide network of magnetic observatories. For some studies it is convenient to approximate the time variation of the spherical harmonic coefficients with a smooth, continuous, function; for this a spline fitting is used. The phenomena that are investigated include periodicities, discontinuities, and correlation with the length of day. The numerical data presented will be of use for further investigations and for the synthesis of secular variation at any place and at any time within the interval of the data - they are not appropriate for temporal extrapolations.

Composition of 12-18 th century window glass in Belgium: Non-figurative windows in secular buildings and stained-glass windows in religious buildings

NASA Astrophysics Data System (ADS)

Schalm, Olivier; Janssens, Koen; Wouters, Hilde; Caluwé, Danielle

2007-07-01

A set of ca. 500 window glass fragments originating from different historical sites in Belgium and covering the period 12 th-18 th century was analyzed by means of electron probe microanalysis. Most samples are archaeological finds deriving from non-figurative windows in secular buildings. However, the analyzed set also contains glass sampled from still existing non-figurative windows in secular buildings and stained-glass windows in religious buildings. A sudden compositional change at the end of the 14 th century can be noticed among the series of glass compositions that were obtained. These changes could be related to the use of different glassmaker recipes and to the introduction of new raw materials for glass making.

Do Secular Trends in Skeletal Maturity Occur Equally in Both Sexes?

PubMed

Duren, Dana L; Nahhas, Ramzi W; Sherwood, Richard J

2015-08-01

Skeletal maturity assessment provides information on a child's physical development and expectations based on chronological age. Given recently recognized trends for earlier maturity in a variety of systems, most notably puberty, examination of sex-specific secular trends in skeletal maturation is important. For the orthopaedist, recent trends and changes in developmental timing can affect clinical management (eg, treatment timing) if they are currently based on outdated sources. (1) Has the male or female pediatric skeleton experienced a secular trend for earlier maturation over the past 80 years? (2) Do all indicators of maturity trend in the same direction (earlier versus later)? In this retrospective study, a total of 1240 children were examined longitudinally through hand-wrist radiographs for skeletal maturity based on the Fels method. All subjects participate in the Fels Longitudinal Study based in Ohio and were born between 1930 and 1964 for the "early" cohort and between 1965 and 2001 for the "recent" cohort. Sex-specific secular trends were estimated for (1) mean relative skeletal maturity through linear mixed models; and (2) median age of maturation for individual maturity indicators through logistic regression and generalized estimating equations. Overall relative skeletal maturity was significantly advanced in the recent cohort (maximum difference of 5 months at age 13 years for girls, 4 months at age 15 years for boys). For individual maturity indicators, the direction and magnitude of secular trends varied by indicator type and sex. The following statistically significant secular trends were found: (1) earlier maturation of indicators of fusion in both sexes (4 months for girls, 3 months for boys); (2) later maturation of indicators of projection in long bones in both sexes (3 months for girls, 2 months for boys); (3) earlier maturation of indicators of density (4 months) and projection (3 months) in carpals and density in long bones (6 months), for girls only; and (4) later maturation of indicators of long bone shape (3 months) for boys only. A secular trend has occurred in the tempo of maturation of individual components of the pediatric skeleton, and it has occurred in a sex-specific manner. The mosaic nature of this trend, with both earlier and later maturation of individual components of the skeletal age phenotype, calls for greater attention to specific aspects of maturation in addition to the overall skeletal age estimate. The Fels method is currently the most robust method for capturing these components, and future work by our group will deliver an updated, user-friendly version of the Fels assessment tool. Appreciation of sex-specific secular changes in maturation is important for clinical management, including treatment timing, of orthopaedic patients, because children today exhibit a different pattern of maturation than children on whom original maturity assessments were based (including Fels and Greulich-Pyle).

Geomagnetic acceleration and rapid hydromagnetic wave dynamics in advanced numerical simulations of the geodynamo

NASA Astrophysics Data System (ADS)

Aubert, Julien

2018-07-01

Geomagnetic secular acceleration, the second temporal derivative of the Earth's magnetic field, is a unique window on the dynamics taking place in the Earth's core. In this study, the behaviours of the secular acceleration and underlying core dynamics are examined in new numerical simulations of the geodynamo that are dynamically closer to the Earth's core conditions than earlier models. These new models reside on a theoretical path in parameter space connecting the region where most classical models are found to the natural conditions. The typical timescale for geomagnetic acceleration is found to be invariant along this path, at a value close to 10 yr that matches the Earth's core estimates. Despite this invariance, the spatio-temporal properties of secular acceleration show significant variability along the path, with an asymptotic regime of rapid rotation reached after 30 per cent of this path (corresponding to a model Ekman number E = 3 × 10-7). In this regime, the energy of secular acceleration is entirely found at periods longer than that of planetary rotation, and the underlying flow acceleration patterns acquire a 2-D columnar structure representative of the rapid rotation limit. The spatial pattern of the secular acceleration at the core-mantle boundary shows significant localization of energy within an equatorial belt. Rapid hydromagnetic wave dynamics is absent at the start of the path because of insufficient timescale separation with convective processes, weak forcing and excessive damping but can be clearly exhibited in the asymptotic regime. This study reports on ubiquitous axisymmetric geostrophic torsional waves of weak amplitude relatively to convective transport, and also stronger, laterally limited, quasi-geostrophic Alfvén waves propagating in the cylindrical radial direction from the tip of convective plumes towards the core-mantle boundary. In a system similar to the Earth's core where the typical Alfvén velocity is significantly larger than the typical convective velocity, quasi-geostrophic Alfvén waves are shown to be an important carrier of flow acceleration to the core surface that links with the generation of strong, short-lived and intermittent equatorial pulses in the secular acceleration energy. The secular acceleration timescale is shown to be insensitive to magnetic signatures from torsional waves because of their weak amplitude, and from quasi-geostrophic Alfvén waves because of their intermittent character, and is therefore only indicative of convective transport phenomena that remain invariant along the parameter space path.

Comments on 'Remarks on the secular change in the energy density spectrum of the geomagnetic field' by Joachim Meyer.

USGS Publications Warehouse

Alldredge, L.R.

1986-01-01

Meyer has discussed only the Rn aspect of the Alldredge (1984) paper he is criticising. He has ignored the pictorial demonstration of the need for higher harmonics to properly describe the secular variation field than the main field as demonstrated. This more or less independent demonstration supports the general conclusion of that paper. -from Author

Harry and Sally Revisited: The Influence of Spirituality and Education on Sexual Tension in Cross-Sex Friendships in Secular and Christian Universities

ERIC Educational Resources Information Center

George, Darren; Adalikwu-Obisike, Justina; Boyko, Jesse; Johnson, Jay; Boscanin, Alex

2014-01-01

A sample of 406 subjects completed a questionnaire testing the influence of personal spirituality, education and several other factors on sexual tension in cross-sex friendships (CSF Tension). The subjects included 143 students from a Christian university (CU), 137 from a secular junior college (JC), and 127 non-students (NS). The primary…

This Earthly World: Edward Said, the Praxis of Secular Humanisms and Situated Cosmopolitanisms

ERIC Educational Resources Information Center

Roman, Leslie G.

2006-01-01

This essay unearths the educational and socio-political implications of Edward W. Said's work for our understanding of what a secular humanism might mean in the highly charged atmosphere of the post-Cold War and September 11 discourses that have pervaded the USA and, to varying degrees, other parts of the world. It asks what it means to move…

Evidence of Secular Changes in Physical Activity and Fitness, but Not Adiposity and Diet, in Welsh 12-13 Year Olds

ERIC Educational Resources Information Center

Thomas, Non E.; Williams, D. R. R.; Rowe, David A.; Davies, Bruce; Baker, Julien S.

2010-01-01

Objective: The aim of the present study was to investigate secular trends in selected cardiovascular disease risk factors (namely adiposity, physical activity, physical fitness and diet) in a sample of Welsh 12-13 year olds between 2002 and 2007. Design: Cross-sectional. Setting: A secondary school based in South West Wales. Method: Two studies in…

Pragmatism and the Unlikely Influence of German Idealism on the Academy in the United States

ERIC Educational Resources Information Center

Ream, Todd C.

2007-01-01

In this article I argue that the subject-object distinction, operative in Continental Europe during the late-1700s and early-1800s, led to the religion-secular distinction in higher education in the United States. Many scholars believe the origins of the shifting nature of the religion-secular distinction resided with some form of influence that…

Faith and HIV prevention: the conceptual framing of HIV prevention among Pentecostal Batswana teenagers.

PubMed

Mpofu, Elias; Nkomazana, Fidelis; Muchado, Jabulani A; Togarasei, Lovemore; Bingenheimer, Jeffrey Bart

2014-03-05

There is a huge interest by faith-based organizations (FBOs) in sub-Saharan Africa and elsewhere in HIV prevention interventions that build on the religious aspects of being. Successful partnerships between the public health services and FBOs will require a better understanding of the conceptual framing of HIV prevention by FBOS to access for prevention intervention, those concepts the churches of various denominations and their members would support or endorse. This study investigated the conceptual framing of HIV prevention among church youths in Botswana;--a country with one of the highest HIV prevalence in the world. Participants were 213 Pentecostal church members (67% female; age range 12 to 23 years; median age=19 years). We engaged the participants in a mixed-method inductive process to collect data on their implicit framing of HIV prevention concepts, taking into account the centrality of religion concepts to them and the moderating influences of age, gender and sexual experience. After, we analysed the data using multi-dimensional scaling (MDS) and hierarchical cluster analysis (HCA) to map the ways the church youths framed HIV prevention. The findings suggest the church youth to conceptually frame their HIV prevention from both faith-oriented and secular-oriented perspectives, while prioritizing the faith-oriented concepts based on biblical teachings and future focus. In their secular-oriented framing of HIV prevention, the church youths endorsed the importance to learn the facts about HIV and AIDS, understanding of community norms that increased risk for HIV and prevention education. However, components of secular-oriented framing of HIV prevention concepts were comparatively less was well differentiated among the youths than with faith-oriented framing, suggesting latent influences of the church knowledge environment to undervalue secular oriented concepts. Older and sexually experienced church youths in their framing of HIV prevention valued future focus and prevention education less than contrasting peer cohorts, suggesting their greater relative risk for HIV infection. A prospective HIV prevention intervention with the Pentecostal church youths would combine both faith and secular informed concepts. It also would need to take into account the ways in which these youth interpret secular-oriented health concepts in the context of their religious beliefs.

New evidence of a fast secular variation of the geomagnetic field 1000 BCE: archaeomagnetic study of Bavarian potteries

NASA Astrophysics Data System (ADS)

Hervé, G.; Gilder, S.; Fassbinder, J.; Metzler-Nebelsick, C.; Schnepp, E.; Geisweid, L.; Putz, A.; Reuss, S.; Riedel, G.; Westhausen, I.; Wittenborn, F.

2016-12-01

This study presents new archaeointensity results obtained on 350 pottery sherds from 45 graves and pits from 12 sites around Munich (Germany). The features are dated between 1400 and 400 BCE by ceramic and metallic artifacts, radiocarbon and dendrochronology. We collected only red- or partly red-colored sherds in order to minimize mineralogical alteration during laboratory experiments. Rock magnetism analyses show that the remanent magnetization is mainly carried by titanomagnetite. Archaeointensities were determined using the Thellier-Thellier protocol with corrections of TRM anisotropy and cooling rate on one to three specimens per sherd. The experiments were completed using Triaxe and multispecimen (MSP-DSC) methods. Around 60 per cent of the sherds provide reliable results, allowing the computation of 35 mean archaeointensity values. This quadruples the number of previously published data in Western Europe. The secular variation of the geomagnetic field strength is low from 1400 to 1200 BCE with intensities close to 50 µT then the intensity increased to 70 µT around 1000-900 BCE. After a minimum 50 µT near 750 BCE, the intensity increased again to 90 µT at 650 BCE. This high secular variation rate (0.4 µT/year) is especially apparent in the sherds from a fountain dated between 750 and 650 BCE. Next, the intensity remained high until 400 BCE before rapidly decreasing to 200 BCE. As the sharp change in geomagnetic direction around 800 BCE is not contemporaneous with an intensity high, this period is probably not characterized by an archaeomagnetic jerk. The trend of secular variation with two intensity maxima is similar to the one observed in the Near East. The Virtual Axial Dipole Moments of the two regions are approximately the same after 700 BCE, but before they are systematically 1-2 × 1022 Am2 higher in the Near East. This difference may be a further proof of a geomagnetic field anomaly in this area 1000 BCE, yet there is no evidence for a geomagnetic spike in Western Europe. Finally, the fast rate of secular variation will provide an improved dating tool for archaeologists together with the available directional secular variation curves.

Predicting Precession Rates from Secular Dynamics for Extra-solar Multi-planet Systems

NASA Astrophysics Data System (ADS)

Van Laerhoven, Christa

2015-12-01

Considering the secular dynamics of multi-planet systems provides substantial insight into the interactions between planets in those systems. Secular interactions are those that don't involve knowing where a planet is along its orbit, and they dominate when planets are not involved in mean motion resonances. These interactions exchange angular momentum among the planets, evolving their eccentricities and inclinations. To second order in the planets' eccentricities and inclinations, the eccentricity and inclination perturbations are decoupled. Given the right variable choice, the relevant differential equations are linear and thus the eccentricity and inclination behaviors can be described as a sum of eigenmodes. Since the underlying structure of the secular eigenmodes can be calculated using only the planets' masses and semi-major axes, one can elucidate the eccentricity and inclination behavior of planets in exoplanet systems even without knowing the planets' current eccentricities and inclinations. I have calculated both the eccentricity and inclination secular eigenmodes for the population of known multi-planet systems whose planets have well determined masses and periods and have used this to predict what range of pericenter precession (and nodal regression) rates the planets may have. One might have assumed that in any given system the planets with shorter periods would have faster precession rates, but I show that this is not necessarily the case. Planets that are 'loners' have narrow ranges of possible precession rates, while planets that are 'groupies' can have a wider range of possible precession rates. Several planets are expected to undergo significant precession on few-year timescales and many planets (though not the majority of planets) will undergo significant precession on decade timescales.

The JCMT Transient Survey: Stochastic and Secular Variability of Protostars and Disks In the Submillimeter Region Observed over 18 Months

NASA Astrophysics Data System (ADS)

Johnstone, Doug; Herczeg, Gregory J.; Mairs, Steve; Hatchell, Jennifer; Bower, Geoffrey C.; Kirk, Helen; Lane, James; Bell, Graham S.; Graves, Sarah; Aikawa, Yuri; Chen, Huei-Ru Vivien; Chen, Wen-Ping; Kang, Miju; Kang, Sung-Ju; Lee, Jeong-Eun; Morata, Oscar; Pon, Andy; Scicluna, Peter; Scholz, Aleks; Takahashi, Satoko; Yoo, Hyunju; The JCMT Transient Team

2018-02-01

We analyze results from the first 18 months of monthly submillimeter monitoring of eight star-forming regions in the JCMT Transient Survey. In our search for stochastic variability in 1643 bright peaks, only the previously identified source, EC 53, shows behavior well above the expected measurement uncertainty. Another four sources—two disks and two protostars—show moderately enhanced standard deviations in brightness, as expected for stochastic variables. For the two protostars, this apparent variability is the result of single epochs that are much brighter than the mean. In our search for secular brightness variations that are linear in time, we measure the fractional brightness change per year for 150 bright peaks, 50 of which are protostellar. The ensemble distribution of slopes is well fit by a normal distribution with σ ∼ 0.023. Most sources are not rapidly brightening or fading at submillimeter wavelengths. Comparison against time-randomized realizations shows that the width of the distribution is dominated by the uncertainty in the individual brightness measurements of the sources. A toy model for secular variability reveals that an underlying Gaussian distribution of linear fractional brightness change σ = 0.005 would be unobservable in the present sample, whereas an underlying distribution with σ = 0.02 is ruled out. Five protostellar sources, 10% of the protostellar sample, are found to have robust secular measures deviating from a constant flux. The sensitivity to secular brightness variations will improve significantly with a sample over a longer time duration, with an improvement by factor of two expected by the conclusion of our 36 month survey.

Weight-Related Teasing from Adolescence to Young Adulthood: Longitudinal and Secular Trends between 1999 and 2010

PubMed Central

Haines, Jess; Hannan, Peter J.; van den Berg, Patricia; Eisenberg, Marla E.; Neumark-Sztainer, Dianne

2012-01-01

The purpose of this study is to examine longitudinal trends from 1999–2010 in weight-related teasing as adolescents transition to young adulthood and to examine secular trends in teasing among early and middle adolescents over the same time period. To examine longitudinal changes we used data from 2,287 participants in Project EAT-III, an ongoing cohort that followed two age cohorts of adolescents from 1999 to 2010. Over the study period the younger cohort transitioned from early adolescence to early young adulthood and the older cohort transitioned from middle adolescence to middle young adulthood. To examine how levels of teasing among early and middle adolescents changed from 1999–2010 (secular trends), we compared baseline data from EAT-I to cross-sectional data from a new cohort of early and middle adolescents that was established in 2010. In 1999, 29% of early adolescent and 23% of middle adolescent females reported being teased. Approximately 18% of males in both age groups reported being teased in 1999. Longitudinal trends suggest that weight-related teasing remained stable among all subgroups as they transitioned to young adulthood, except among early adolescent males where teasing increased to 27% in early young adulthood. Analyses of age-matched secular trends show that teasing decreased by 10.4% among early adolescent females and by 7.6% among middle adolescent males from 1999–2010. Results suggest that interventions that focus on reducing weight-based discrimination are needed throughout adolescence and young adulthood. The secular decrease in weight-related teasing is promising, but the high prevalence of teasing remains a public health concern. PMID:23585224

[The beginnings of the nursing profession : the complementary relationship between secular caregivers and hospital nuns in France in the 17th and 18th centuries].

PubMed

Diebolt, Evelyne

2013-06-01

The words used for designating the caregivers are ambiguous. Little by little, the word "nurse" becomes widely used, mainly in the feminine form due to the need of specialized staff. Health care structures are developing in the 17th and 18 centuries, the remains of which you can find in today hospitals (Salpêtrière hospital, Hôtel-Dieu hospital in Paris). The government of Louis XIV cares for the poor sick people, the vagabonds and the beggars. It opens new general hospitals as it will be the case later in all Europe. In the 17th century, the staff of the general hospital in Paris is entirely secular. The Paris general hospital is headed by the magistrates of Paris Parliament. The healthcare institutions employ both secular and religious staff for example the Hotel Dieu in Paris and the one in Marseilles. In the 17th century, there are 2000 secular caregivers in France. The order of the "Filles de la Charité" (grey sisters) is not submitted to the rule of enclosure. They renew their vows every year. For their founders Vincent de Paul and Louise de Marcillac, their monastery should be the cells of the sick, their cloister should be the rooms of the hospitals or the streets of the town. The secular or religious caregivers are excellent in the apothecary and they open a network of small dispensaries. It improves the health of the French population and allows fighting against the epidemics. This activity allowed some women to have a rewarding activity and a social status of which they were apparently satisfied.

Accounting for magnetic diffusion in core flow inversions from geomagnetic secular variation

NASA Astrophysics Data System (ADS)

Amit, Hagay; Christensen, Ulrich R.

2008-12-01

We use numerical dynamos to investigate the possible role of magnetic diffusion at the top of the core. We find that the contribution of radial magnetic diffusion to the secular variation is correlated with that of tangential magnetic diffusion for a wide range of control parameters. The correlation between the two diffusive terms is interpreted in terms of the variation in the strength of poloidal flow along a columnar flow tube. The amplitude ratio of the two diffusive terms is used to estimate the probable contribution of radial magnetic diffusion to the secular variation at Earth-like conditions. We then apply a model where radial magnetic diffusion is proportional to tangential diffusion to core flow inversions of geomagnetic secular variation data. We find that including magnetic diffusion does not change dramatically the global flow but some significant local variations appear. In the non frozen-flux core flow models (termed `diffusive'), the hemispherical dichotomy between the active Atlantic and quiet Pacific is weaker, a cyclonic vortex below North America emerges and the vortex below Asia is stronger. Our results have several important geophysical implications. First, our diffusive flow models contain some flow activity at low latitudes in the Pacific, suggesting a local balance between magnetic field advection and diffusion in that region. Second, the cyclone below North America in our diffusive flows reconciles the difference between mantle-driven thermal wind predictions and frozen-flux core flow models, and is consistent with the prominent intense magnetic flux patch below North America in geomagnetic field models. Finally, we hypothesize that magnetic diffusion near the core surface plays a larger role in the geomagnetic secular variation than usually assumed.

f-Mode Secular Instabilities in Deleptonizing Fizzlers

NASA Astrophysics Data System (ADS)

Imamura, James N.; Durisen, Richard H.

2004-12-01

Fizzlers are intermediate states that may form between white dwarf and neutron star densities during the collapse of massive rotating stars. This paper studies the gravitational radiation reaction (GRR) driven f-mode secular instabilities of fizzlers with angular momentum distributions h(mc) appropriate to the core collapse of massive rotating stars, where h is the specific angular momentum and mc is the cylindrical mass fraction. For core collapses that maintain axial symmetry, the h(mc) of the remnant reflects the conditions in the precollapse stellar core, and, thus, the h(mc) will resemble that of a uniformly rotating star supported by the pressure of relativistically degenerate electrons. Such an h(mc) concentrates most angular momentum toward the equatorial region of the object. The onset of f-mode secular instabilities in such fizzlers is affected strongly by the h(mc), whereas instability depends only weakly on compressibility. For a broad range of fizzler equations of state and the core h(mc), the f-mode secular instability thresholds drop to T/W~0.034-0.042, 0.019-0.021, and 0.012-0.0135, for m=2, 3, and 4, respectively. These same thresholds with the Maclaurin spheroid h(mc) are T/W=0.13-0.15, 0.10-0.11, and 0.08-0.09, respectively. The growth times τgw for GRR-driven m=2 modes are long. For fizzlers with specific angular momentum J/M~1.5×1016 cm2 s-1 and T/W<~0.24 (ρc<~1014 g cm-3), τgw>400 s. For these fizzlers, τgw>>τde, the deleptonization timescale, and GRR-driven secular instabilities will not grow along a deleptonizing fizzler sequence except, possibly, at T/W near the dynamic bar mode instability threshold, T/W~0.27.

Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers

NASA Astrophysics Data System (ADS)

Snyder, Dalton T.; Pulliam, Christopher J.; Wiley, Joshua S.; Duncan, Jason; Cooks, R. Graham

2016-07-01

Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection.

Experimental Characterization of Secular Frequency Scanning in Ion Trap Mass Spectrometers.

PubMed

Snyder, Dalton T; Pulliam, Christopher J; Wiley, Joshua S; Duncan, Jason; Cooks, R Graham

2016-07-01

Secular frequency scanning is implemented and characterized using both a benchtop linear ion trap and a miniature rectilinear ion trap mass spectrometer. Separation of tetraalkylammonium ions and those from a mass calibration mixture and from a pesticide mixture is demonstrated with peak widths approaching unit resolution for optimized conditions using the benchtop ion trap. The effects on the spectra of ion trap operating parameters, including waveform amplitude, scan direction, scan rate, and pressure are explored, and peaks at black holes corresponding to nonlinear (higher-order field) resonance points are investigated. Reverse frequency sweeps (increasing mass) on the Mini 12 are shown to result in significantly higher ion ejection efficiency and superior resolution than forward frequency sweeps that decrement mass. This result is accounted for by the asymmetry in ion energy absorption profiles as a function of AC frequency and the shift in ion secular frequency at higher amplitudes in the trap due to higher order fields. We also found that use of higher AC amplitudes in forward frequency sweeps biases ions toward ejection at points of higher order parametric resonance, despite using only dipolar excitation. Higher AC amplitudes also increase peak width and decrease sensitivity in both forward and reverse frequency sweeps. Higher sensitivity and resolution were obtained at higher trap pressures in the secular frequency scan, in contrast to conventional resonance ejection scans, which showed the opposite trend in resolution on the Mini 12. Mass range is shown to be naturally extended in secular frequency scanning when ejecting ions by sweeping the AC waveform through low frequencies, a method which is similar, but arguably superior, to the more usual method of mass range extension using low q resonance ejection. Graphical Abstract ᅟ.

Determining The Plane of The Kuiper Belt with OSSOS

NASA Astrophysics Data System (ADS)

Van Laerhoven, Christa; Kavelaars, J. J.; Volk, Kathryn; Gladman, Brett; Petit, Jean-Marc

2018-04-01

We present the OSSOS-based measurement of the semi-major axes dependent orientation of the Kuiper Belt plane. A Kuiper Belt object's (KBO's) inclination can be broken down into a forced component and a free component. The inclination and longitude of ascending node of the forced inclination define the 'forced plane,' the plane about which the KBO's inclination will precess. Secular theory predicts that this forced plane should depend on semi-major axis. For example, the nu18 secular resonance should create a significant warp in the forced planet near 40.5 au (Chiang and Choi 2008). Not predicted by secular theory is a warp in the distant Kuiper Belt (semi-major axes greater than 50 au) seen by Volk and Malhotra 2016 using KBOs from the Minor Planet Catalog. We investigate what the inclination distribution is for objects beyond Neptune as a function of semi-major axis using the OSSOS characterized sample. Through use of the OSSOS survey simulator we test various underlying orbital distributions and compare how the survey would have observed those populations to the actual observed sample. In particular, we test various widths for the inclination distribution about various local forcing planes for the kernel, stirred, and hot classical Kuiper Belt. We find that the forced plane in matches well with the expected forced plane from secular theory. Through most of the main Kuiper Belt (between the 3:2 and 2:1 resonances), we can reject both the ecliptic plane and the invariable plane as the true forced plane. Only as the expected secularly forced plane approaches the invariable plane does the invariable plane become non-rejectable. In the outer Kuiper Belt we reject the nominal mean-plane measured by Volk and Malhotra, but smaller warps are still allowed by the data.

Orbital period studies of the two contact binaries TZ Bootis and Y Sextantis

NASA Astrophysics Data System (ADS)

Qian, S.; Liu, Q.

2000-03-01

The physical properties of the two A-type contact binaries TZ Boo and Y Sex are nearly the same. In the present paper, many of their published times of light minima are collected and the changes in their orbital periods are analyzed. It is indicated that the orbital period of TZ Boo shows several alternating jumps while it undergoes a secular decrease of -11.8x10-8 days/year. Several random jumps superposed on a secular decrease (-5.5x10-8 days/year) are also found in the period of Y Sex. The secular decrease is usually interpreted as mass transfer from the more to the less massive components, or mass and angular momentum loss (AML) from the systems. According to the AML theory, on the contact stage, the orbital AML is mainly caused by the mass transfer from the less to the more massive component and the mass ratio decreasing and orbital period gradually increasing are the corresponding results. The extremely low mass ratio and orbital angular momentum of the two systems show that they are evolved via AML and the present secular decrease in the periods may suggest that the magnetic activity in the two systems are very strong. The relation between the changes of the orbital periods and the magnetic activity in the two systems are discussed. We think that the interplay between the variable AML and variable magnetic coupling can explain both the jumps and secular decrease in the orbital periods of the two systems. Table~2 and Table~4 are only available in electronic form at the CDS via anonymous ftp to cdsarc.u-strabg.fr (130.79.128.5) or via http://cdsweb.u-strasbg.fr/Abstract.html

The PET radioligand [carbonyl-(11)C]desmethyl-WAY-100635 binds to 5-HT(1A) receptors and provides a higher radioactive signal than [carbonyl-(11)C]WAY-100635 in the human brain.

PubMed

Andrée, Bengt; Halldin, Christer; Pike, Victor W; Gunn, Roger N; Olsson, Hans; Farde, Lars

2002-03-01

5-Hydroxytryptamine (serotonin)-1A (5-HT(1A)) receptors are of key interest in research on the pathophysiology and treatment of psychiatric disorders. The PET radioligand [carbonyl-(11)C]WAY-100635 ((11)C-WAY), where WAY-100635 is (3)H-(N-(2-(1-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridyl) cyclohexane-carboxamide, is commonly used for quantitation of 5-HT(1A) receptors in the human brain. The aim of this PET study was to compare (11)C-WAY with the putative metabolite and selective radioligand [carbonyl-(11)C]desmethyl-WAY-100635 ((11)C-DWAY). A PET examination was performed on each of 5 healthy male volunteers after intravenous injection of (11)C-WAY and (11)C-DWAY on separate occasions. Radioactive metabolites in plasma were determined with high-performance liquid chromatography. The plasma metabolite--corrected input function was used in a kinetic compartment analysis. The simplified reference tissue model and peak equilibrium method, using the cerebellum as reference region, was applied for comparison of data. For both radioligands, the highest radioactivity was observed in the neocortex and the raphe nuclei, whereas radioactivity was low in the cerebellum. The regional binding potentials were similar for the 2 radioligands. The brain uptake was more than 2-fold higher for (11)C-DWAY than for (11)C-WAY, in part because of higher delivery (first-order rate constant K(1), 0.38 vs. 0.16). The time--activity curves were well described by a 3-compartment model for all regions, whereas uptake in the cerebellum could not be described by a 2-compartment model, supporting the existence of kinetically distinguishable nonspecific binding in the cerebellum or radioactive metabolites in the brain for both radioligands. Both radioligands were rapidly metabolized, and <10% of the radioactivity in plasma represented unchanged (11)C-WAY or (11)C-DWAY at 10 min after injection. The metabolic pattern was similar for both radioligands, with the formation of radiolabeled cyclohexanecarboxylic acid and more polar components. For (11)C-WAY, small amounts of an additional labeled metabolite comigrated with reference desmethyl-WAY-100635. The advantages of (11)C-DWAY over (11)C-WAY for research on central 5-HT(1A) receptors is supported by a significantly higher radioactivity signal at equipotent doses, providing improved imaging statistics and advantages in biomathematic modeling and the preclusion of (11)C-DWAY as a metabolite interfering with PET measurements.

Tidal Disruption Events from Eccentric Nuclear Disks

NASA Astrophysics Data System (ADS)

Wernke, Heather N.; Madigan, Ann-Marie

2018-04-01

Stars that get too close to a supermassive black hole are in danger of being tidally disrupted. Stellar two-body relaxation is commonly assumed to be the main driver of these events. Recent work has shown, however, that secular gravitational torques from eccentric nuclear disks can push stars to extreme eccentricities at much higher rates than predicted by two-body relaxation. This work did not include the effects of general relativity, however, which could quench secular torques via rapid apsidal precession. Here we show that, for a star in danger of disruption, general relativity acts on a timescale of less than an orbital period. This short timescale means that general relativity does not have enough time to have a major effect on the orbit. When driven by secular torques from eccentric nuclear disks, tidal disruption event rates are not affected by general relativity.

The equations of motion of a secularly precessing elliptical orbit

NASA Astrophysics Data System (ADS)

Casotto, S.; Bardella, M.

2013-01-01

The equations of motion of a secularly precessing ellipse are developed using time as the independent variable. The equations are useful when integrating numerically the perturbations about a reference trajectory which is subject to secular perturbations in the node, the argument of pericentre and the mean motion. Usually this is done in connection with Encke's method to ensure minimal rectification frequency. Similar equations are already available in the literature, but they are either given based on the true anomaly as the independent variable or in mixed mode with respect to time through the use of a supporting equation to track the anomaly. The equations developed here form a complete and independent set of six equations in time. Reformulations both of Escobal's and Kyner and Bennett's equations are also provided which lead to a more concise form.

Secular Effect of Sun Oblateness on the Orbital Parameters of Mars and Jupiter

NASA Astrophysics Data System (ADS)

Vaishwar, Avaneesh; Kushvah, Badam Singh; Mishra, Devi Prasad

2018-01-01

In this paper we considered the Mars-Jupiter system to study the behaviour of Near Earth Asteroids (NEAs) as most of the NEAs originate in the main asteroid belt located between Mars and Jupiter. The materials obtained from NEAs are very useful for space industrialisation. The variations in orbital parameters, such as eccentricity, inclination, longitude of pericenter and longitude of ascending node of Mars and Jupiter were investigated for a time span of 200,000 years centered on J2000 (January 2000) using secular perturbation theory. We considered the Sun oblateness and studied the effect of Sun oblateness on orbital parameters of Mars and Jupiter. Moreover, we determined the orbital parameters for asteroids moving under the perturbation effect of Mars and Jupiter by using a secular solution of Mars-Jupiter system.

Secular trends in growth.

PubMed

Fudvoye, Julie; Parent, Anne-Simone

2017-06-01

Human adult height has been increasing world-wide for a century and a half. The rate of increase depends on time and place of measurement. Final height appears to have reached a plateau in Northern European countries but it is still increasing in southern European countries as well as Japan. While mean birth length has not changed recently in industrialized countries, the secular trend finally observed in adult height mostly originates during the first 2 years of life. Secular trend in growth is a marker of public health and provides insights into the interaction between growth and environment. It has been shown to be affected by income, social status, infections and nutrition. While genetic factors cannot explain such rapid changes in average population height, epigenetic factors could be the link between growth and environment. Copyright © 2017. Published by Elsevier Masson SAS.

Secular changes of the M2 tide in the Gulf of Maine

NASA Technical Reports Server (NTRS)

Ray, Richard D.

2005-01-01

Analyses of long time series of hourly tide-gauge data at four stations in the Gulf of Maine reveal that the amplitude of the M2 tide underwent a nearly linear secular increase throughout most of the twentieth century. In the early 1980s, however, the amplitude of M2 abruptly dropped. Sea level changes alone appear inadequate to explain either the long-term trend or the recent trend discontinuity. Tidal models that account for Holocene sea level rise do predict an amplification of M2, but much smaller than the currently observed trends. Nor do recent annual mean sea levels correlate with the recent trend discontinuity. Some unknown fraction of the open Atlantic may be similarly affected, since the M2 discontinuity, but not the long-term secular increase in the tide, is evident also at Halifax.

Topographic and Other Influences on Pluto's Volatile Ices

NASA Astrophysics Data System (ADS)

Lewis, Briley Lynn; Stansberry, John; Grundy, William M.; Schmitt, Bernard; Protopapa, Silvia; Trafton, Laurence M.; Holler, Bryan J.; McKinnon, William B.; Schenk, Paul M.; Stern, S. Alan; Young, Leslie; Weaver, Harold A.; Olkin, Catherine; Ennico, Kimberly; New Horizons Science Team, The New Horizons Composition Team

2018-01-01

Pluto’s surface is known to consist of various volatile ices, mostly N2, CH4, and CO, which sublimate and condense on varying timescales, generally moving from points of high insolation to those of low insolation. The New Horizons Pluto encounter data provide multiple lenses through which to view Pluto’s detailed surface topography and composition and to investigate the distribution of volatiles on its surface, including albedo and elevation maps from the imaging instruments and composition maps from the LEISA spectral imager. The volatile surface ice is expected to be generally isothermal, due to the fact that their vapor pressures are in equilibrium with the atmosphere. Although secular topographic transport mechanisms suggest that points at low elevation should slowly fill with volatile ices (Trafton 2015 DPS abstract, Bertrand and Forget 2017), there are counter-examples of this across the surface, implying that energy discrepancies caused by insolation differences, albedo variations, local slopes, and other effects may take precedence at shorter timescales. Using data from the 2015 New Horizons flyby, we present our results of this investigation into the effects of variations in insolation, albedo, and topography on the presence of the different volatile ices across the surface of Pluto.

Topographic and Other Influences on Pluto's Volatile Ices

NASA Astrophysics Data System (ADS)

Lewis, Briley Lynn; Stansberry, John; Grundy, William M.; Schmitt, Bernard; Protopapa, Silvia; Trafton, Laurence M.; Holler, Bryan J.; McKinnon, William B.; Schenk, Paul M.; Stern, S. Alan; Young, Leslie; Weaver, Harold A.; Olkin, Catherine; Ennico, Kimberly; New Horizons Science Team

2017-10-01

Pluto’s surface is known to consist of various volatile ices, mostly N2, CH4, and CO, which sublimate and condense on varying timescales, generally moving from points of high insolation to those of low insolation. The New Horizons Pluto encounter data provide multiple lenses through which to view Pluto’s detailed surface topography and composition and to investigate the distribution of volatiles on its surface, including albedo and elevation maps from the imaging instruments and composition maps from the LEISA spectral imager. The volatile surface ice is expected to be generally isothermal, due to the fact that their vapor pressures are in equilibrium with the atmosphere. Although secular topographic transport mechanisms suggest that points at low elevation should slowly fill with volatile ices (Trafton 2015 DPS abstract, Bertrand and Forget 2017), there are counter-examples of this across the surface, implying that energy discrepancies caused by insolation differences, albedo variations, local slopes, and other effects may take precedence at shorter timescales. Using data from the 2015 New Horizons flyby, we present our results of this investigation into the effects of variations in insolation, albedo, and topography on the presence of the different volatile ices across the surface of Pluto.

Results from the (U-Th)/He dating systems in Japan Atomic Energy Agency

NASA Astrophysics Data System (ADS)

Yamada, K.; Hanamuro, T.; Tagami, T.; Yamada, R.; Umeda, K.

2007-12-01

Japan Atomic Energy Agency (JAEA) has jointly set up the lab of the (U-Th)/He dating in cooperation with Kyoto University and National Research Institute for Earth Science and Disaster Prevention. We use the MM5400 rare gas mass spectrometer and the SPQ9000 ICP quadrupole mass spectrometer, belonging to JAEA, and built a new vacuum heater using infrared laser to extract helium. HF decomposes zircon after the alkali-fusion method using XRF bead sampler and LiBO3 in the preparation of ICP solution. Helium is quantified using sensitivity method. Uranium and thorium are using standard addition method. Quantifications of uranium-238 and thorium-232 are only need for parent isotopes to date samples because they are expected that the state of secular equilibrium becomes established and samarium does not compose the samples. At the present stage, we calibrate our systems by dating some standards, such as zircon from the Fish Canyon Tuff and apatite from the Durango, those are the international age standard, and apatite and zircon from the Tanzawa Tonalite Complex, that was dated in Yamada's PhD thesis, as a working standard. We report the results and detailed views of the dating systems.

[Civic religion, civil religion, secular religion. a historiographical investigation].

PubMed

Boucheron, Patrick

2013-01-01

Because of its conceptual plasiticity, the term civic religion is now widely used by historians, particularly historians of the Middle Ages. Yet, as this article suggests, historians would do well to interrogate the relationships (which can be hidden) that this term bears to similar concepts such as Greek Roman civic religion, Enlightenment civil religion or even the secular religion that emerged in the work of 20(th) century thinkers.

Historical Improvements in Well-Being Do Not Hold in Late Life: Birth- and Death-Year Cohorts in the United States and Germany

ERIC Educational Resources Information Center

Hülür, Gizem; Ram, Nilam; Gerstorf, Denis

2015-01-01

One key objective of life span research is to examine how individual development is shaped by the historical time people live in. Secular trends favoring later-born cohorts on fluid cognitive abilities have been widely documented, but findings are mixed for well-being. It remains an open question whether secular increases in well-being seen in…

The long-term evolution of known resonant trans-Neptunian objects

NASA Astrophysics Data System (ADS)

Saillenfest, M.; Lari, G.

2017-07-01

Aims: Numerous trans-Neptunian objects are known to be in mean-motion resonance with Neptune. We aim to describe their long-term orbital evolution (both past and future) by means of a one-degree-of-freedom secular model. In this paper, we focus only on objects with a semi-major axis larger than 50 astronomical units (au). Methods: For each resonant object considered, a 500 000-year numerical integration is performed. The output is digitally filtered to get the parameters of the resonant secular model. Their long-term (Giga-year) orbital evolution is then represented by the level curves of the secular Hamiltonian. Results: For the majority of objects considered, the mean-motion resonance has little impact on the long-term trajectories (the secular dynamics is similar to a non-resonant one). However, a subset of objects is strongly affected by the resonance, producing moderately-high-amplitude oscillations of the perihelion distance and/or libration of the argument of perihelion around a fixed centre. Moreover, the high perihelion distance of the object 2015 FJ345 is plainly explained by long-term resonant dynamics, allowing us to also deduce its orbital elements at the time of capture in resonance (at least 15 million years ago). The same type of past evolution is expected for 2014 FZ71.

Radioactive and Stable Cesium Distributions in Fukushima Forests

NASA Astrophysics Data System (ADS)

Ioshchenko, V.; Kivva, S.; Konoplev, A.; Nanba, K.; Onda, Y.; Takase, T.; Zheleznyak, M.

2015-12-01

Fukushima Dai-ichi NPP accident has resulted in release into the environment of large amounts of 134Cs and 137Cs and in radioactive contamination of terrestrial and aquatic ecosystems. In Fukushima prefecture up to 2/3 of the most contaminated territory is covered with forests, and understanding of its further fate in the forest ecosystems is essential for elaboration of the long-term forestry strategy. At the early stage, radiocesium was intercepted by the trees' canopies. Numerous studies reported redistribution of the initial fallout in Fukushima forests in the followed period due to litterfall and leaching of radiocesium from the foliage with precipitations. By now these processes have transported the major part of deposited radiocesium to litter and soil compartments. Future levels of radiocesium activities in the aboveground biomass will depend on relative efficiencies of the radiocesium root uptake and its return to the soil surface with litterfall and precipitations. Radiocesium soil-to-plant transfer factors for typical tree species, soil types and landscape conditions of Fukushima prefecture have not been studied well; moreover, they may change in time with approaching to the equilibrium between radioactive and stable cesium isotopes in the ecosystem. The present paper reports the results of several ongoing projects carried out by Institute of Environmental Radioactivity of Fukushima University at the experimental sites in Fukushima prefecture. For typical Japanese cedar (Cryptomeria japonica) forest, we determined distributions of radiocesium in the ecosystem and in the aboveground biomass compartments by the end of 2014; available results for 2015 are presented, too, as well as the results of test application of D-shuttle dosimeters for characterization of seasonal variations of radiocesium activity in wood. Based on the radiocesium activities in biomass we derived the upper estimates of its incorporation and root uptake fluxes, 0.7% and 3% of the total inventory in the ecosystem. Measurements of stable cesium concentrations in the biomass compartments enabled obtaining the more precise estimates. Return fluxes of both radioactive and stable cesium also were quantified, which forms the basis for modelling of the long-term redistribution of radiocesium in the studied ecosystem.

Exploring Radioactive Decay and Geochronology through Hydrostatic Principles

NASA Astrophysics Data System (ADS)

Claiborne, L. L.; Miller, C. F.

2008-12-01

One of the most essential tools to unraveling Earth's history and the processes involved in shaping our planet is an understanding of deep time and the timescales involved in geologic processes. The primary process that allows quantification of this history is radioactive decay of unstable isotopes within earth materials, and as one of the most essential tools in geology, this concept is taught at all levels of geoscience education. The concept of radioactive decay contains nuances that are often lost on students during lectures, and students often express low confidence in their comprehension of the concept. The goal of this laboratory activity is for students to understand radioactive decay including what controls it, how it proceeds and what information it provides, along with developing higher level scientific skills including making observations and predictions, and creating and interpreting quantitative graphical representations of data. The activity employs graduated beakers, shampoo, and stopwatches. Students pour shampoo put into an upper beaker (representing the parent isotope) with a hole in the base and allow it to flow into a lower beaker (representing the daughter isotope). Students measure changes in liquid depth with time, relating this to the amount of decay and its dependence on the amount of parent available (depth of liquid) and the decay constant (area of the hole in the beaker). Several beakers with varying sized holes illustrate variations specific to the different parent isotopes. They then explore graphical representations of their "decay" data, discovering for themselves which kinds of plots yield the equations and constants that control the decay process and the derived quantity of the "half-life", and are therefore the most useful. Making their own measurements, creating graphs, and then calculating these fundamental quantities is both enlightening and empowering. An advanced variation of this experiment involves students predicting the results and/or designing an experiment to address complex decay chains, where the daughter products are radioactive themselves. This permits them to investigate connections between 'activity' and equilibrium and to understand how disequilibrium can develop and be used for dating. In order to evaluate the success of the activity, each student participates in pre and post assessment including stating their confidence in their understanding of the concept.

Borehole Tilt Measurements at the Charlevoix Observatory, Quebec.

DTIC Science & Technology

1983-01-31

1q. KEY WORDS (Continue on reverse side it necessary end identify by block number) Borehole tiltmeter Earthquakes Tidal, secular and transient tilts 20...ABSTRACT (Continue on reverse side If necessary and Identify by block number) An array of three Bodenseewerk Gbp borehole tiltmeters has been...established to measure tidal, transient and secular tilting of the Earth’s surface in the Charlevoix region of Quebec. Two of the tiltmeters operate at a

To Our Great Detriment: Ignoring What Extremists Say About Jihad

DTIC Science & Technology

2007-07-01

scripture of Islam itself, Western analysts tried to explain it in political and economic terms in keeping with their own secular- humanistic orientation...virtue of the fact that it is said or written, is meant to indicate that the Orientalist is outside the Orient, both as an existential and moral fact...with their own secular- humanistic orientation.606 (Emphasis added) In the same article, hardly religious and written by a Hindu, Rajaram argues

Spatial Distribution and Secular Variation of Geomagnetic Filed in China Described by the CHAOS-6 Model and its Error Analysis

NASA Astrophysics Data System (ADS)

Wang, Z.; Gu, Z.; Chen, B.; Yuan, J.; Wang, C.

2016-12-01

The CHAOS-6 geomagnetic field model, presented in 2016 by the Denmark's national space institute (DTU Space), is a model of the near-Earth magnetic field. According the CHAOS-6 model, seven component data of geomagnetic filed at 30 observatories in China in 2015 and at 3 observatories in China spanning the time interval 2008.0-2016.5 were calculated. Also seven component data of geomagnetic filed from the geomagnetic data of practical observations in China was obtained. Based on the model calculated data and the practical data, we have compared and analyzed the spatial distribution and the secular variation of the geomagnetic field in China. There is obvious difference between the two type data. The CHAOS-6 model cannot describe the spatial distribution and the secular variation of the geomagnetic field in China with comparative precision because of the regional and local magnetic anomalies in China.

A paired apatite and calcite clumped isotope thermometry approach to estimating Cambro-Ordovician seawater temperatures and isotopic composition

NASA Astrophysics Data System (ADS)

Bergmann, Kristin D.; Finnegan, Seth; Creel, Roger; Eiler, John M.; Hughes, Nigel C.; Popov, Leonid E.; Fischer, Woodward W.

2018-03-01

The secular increase in δ18O values of both calcitic and phosphatic marine fossils through early Phanerozoic time suggests either that (1) early Paleozoic surface temperatures were high, in excess of 40 °C (tropical MAT), (2) the δ18O value of seawater has increased by 7-8‰ VSMOW through Paleozoic time, or (3) diagenesis has altered secular trends in early Paleozoic samples. Carbonate clumped isotope analysis, in combination with petrographic and elemental analysis, can deconvolve fluid composition from temperature effects and therefore determine which of these hypotheses best explain the secular δ18O increase. Clumped isotope measurements of a suite of calcitic and phosphatic marine fossils from late Cambrian- to Middle-late Ordovician-aged strata-the first paired fossil study of its kind-document tropical sea surface temperatures near modern temperatures (26-38 °C) and seawater oxygen isotope ratios similar to today's ratios.

Perturbations of non-resonant satellite orbits due to a rotating earth. [tesseral harmonics and the Von Ziepel method

NASA Technical Reports Server (NTRS)

Mueller, A.

1978-01-01

The dominant perturbations of the motion of a satellite near the earth are due to atmospheric drag and the non-symmetrical gravitational field. Atmospheric drag perturbation continually pulls the satellite in and out of the different long period resonant frequencies. The result is that the resonances never become apparent and may be neglected. The tesseral harmonics have no true secular perturbation but the periodicities in the mean motion induce a secular perturbation in the mean anomaly. This secular perturbation may be determined by simply using the average mean motion instead of the osculating mean motion. The Von Ziepel method is used to determine tesseral perturbations. The solution is found first in the singular DS phi elements and then rewritten in the PS phi elements to remove singularities. The notation used in the development is described in the appendix.

Some ideas on the rock cycle: 1788-1988

NASA Astrophysics Data System (ADS)

Gregor, Bryan

1992-08-01

Hutton's procrastination on the subject of unconformities left his cyclic vision of geology in the shadows, while his success in demonstrating the igneous origin of granite led on to Classical Magmatism, a paradigm of secular evolution that reigned practically unchallenged for almost a century. When radiometric dating revealed the true extent of geologic time, a neo-Huttonian, cyclic view gained strength in Europe because of its ability to explain the salt content of the ocean and the sodium fixed in metamorphism of sediments to paragneiss, both of which had become embarrassing to the magmatists. Meantime, in North America, a quite independent movement was afoot to claim for sediments and cyclic processes their rightful place in geologic theory. It led to the acknowledgment that the cyclic and secular views of the Earth are complementary and not contradictory, and that geologic materials are recycled on varying time scales against a background of slow, secular evolution of the Earth.

Intergenerational Transmission of Religious Beliefs and Practices and the Reduction of Adolescent Delinquency in Urban Thailand

PubMed Central

Chamratrithirong, Aphichat; Miller, Brenda A.; Byrnes, Hilary F.; Rhucharoenpornpanich, Orratai; Cupp, Pamela K.; Rosati, Michael J.; Fongkaew, Warunee; Atwood, Katharine A.; Todd, Michael

2012-01-01

This study examines the intergenerational transmission of family religion as measured by parent’s and adolescent’s beliefs and practices in Buddhism, and its relation to delinquent behaviors among early adolescents in Thailand. The data set is from the Thai Family Matters Project 2007, a representative sample of 420 pairs of parents and teens in Bangkok. A structural equation model is employed for the analysis. The intergenerational transmission and the direct and indirect association between parents’ and adolescents’ beliefs and practices in Buddhism and adolescents’ minor and serious delinquent behaviors are revealed to be significant, controlling for secular parental monitoring. Spirituality within the family can play an important role in preventing delinquency among early adolescents. Policies in the areas related to family empowerment and delinquency prevention may need to consider integrating both secular and non-secular program inputs in their implementation design. PMID:23218782

On the secular decrease in the semimajor axis of Lageos orbit

NASA Technical Reports Server (NTRS)

Rubincam, D. P.

1980-01-01

The semimajor axis of the Lageos orbit is decreasing secularly at the rate of -1.1 mm/day due to an unknown force. Nine possible mechanisms are investigated. Five of the mechanisms, resonance with the Earth's gravitational field, gravitational radiation, the Poynting-Robertson effect, transfer of spin angular momentum to the orbital angular momentum, and drag from near Earth dust are ruled out because they are too small to require unacceptable assumptions to account for the observed rate. Three other mechanisms, the Yarkovsky effect, the Schach effect, and terrestrial radiation pressure could possibly give the proper order of magnitude for the decay rate, but the characteristic signatures of these perturbations do not agree with the observed secular decrease. Atmospheric drag from a combination of charged and neutral particles is the most likely cause for the orbital decay. This mechanism explains at least 71 percent of the observed rate of decrease of the semimajor axis.

Extracurricular activities and teens' alcohol use: The role of religious and secular sponsorship.

PubMed

Adamczyk, Amy

2012-03-01

Much research has found that more religious youth are less likely to engage in riskier health-related behaviors. However, very little research has examined the role that religion may play in shaping the health-related behaviors of secular youth. There is reason to think that more and less religious youth may gain some health-related benefits from involvement with religious organizations through activities such as basketball and volunteering. Using two waves of data from the National Study of Youth and Religion, this study finds that involvement in religion-supported secular activities is associated with less alcohol use for all involved teens. The number of friends who belong to a religious youth group, in part, explains the relationship. Conversely, network overlap between parents and teens, the number of friends who drink or use drugs, and having an adult confidant from a religious group are not mechanisms that mediate the relationship. Published by Elsevier Inc.

Simultaneous Measurements of Nanoaerosols and Radioactive Aerosols Containing the Short-lived Radon Isotopes.

PubMed

Otahal, P P S; Burian, I; Ondracek, J; Zdimal, V; Holub, R F

2017-11-01

The activity size distribution of the Equilibrium-Equivalent Concentration (EER) of 222Rn is one of the most important parameters for the estimation of radiation dose by inhalation of radon decay products. A series of measurements of the EER activity size distribution were performed by the screen diffusion battery in Radon-Aerosol chamber (10 m3) at the National Institute for Nuclear, Chemical, and Biological Protection (SUJCHBO). These measurements were performed at different levels of radon concentration. For this study, the Graded Screen Array Diffusion Battery (GSA DB), developed by the SUJCHBO (based on Earl Knutson and Robert F Holub design), consists of 10 screens and backup filter used to collect all particles that penetrated the screens. The measuring range of this GSA DB allows measuring the radioactive nanoaerosols in the size range from 0.5 to 100 nm. The Earl Knutson algorithm was used for EER activity size distribution evaluation. The results of EER activity size distribution were subsequently compared with the aerosol particle size distribution measured by Scanning Mobility Particle Sizer Spectrometer (SMPS 3936 N, TSI Inc., MN, USA). © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

U-Pb ages of secondary silica at Yucca Mountain, Nevada: Implications for the paleohydrology of the unsaturated zone

USGS Publications Warehouse

Neymark, L.A.; Amelin, Y.; Paces, J.B.; Peterman, Z.E.

2002-01-01

Uranium, Th and Pb isotopes were analyzed in layers of opal and chalcedony from individual mm- to cm-thick calcite and silica coatings at Yucca Mountain, Nevada, USA, a site that is being evaluated for a potential high-level nuclear waste repository. These calcite and silica coatings on fractures and in lithophysal cavities in Miocene-age tuffs in the unsaturated zone (UZ) precipitated from descending water and record a long history of percolation through the UZ. Opal and chalcedony have high concentrations of U (10 to 780 ppm) and low concentrations of common Pb as indicated by large values of 206Pb/204Pb (up to 53,806), thus making them suitable for U-Pb age determinations. Interpretations of U-Pb isotope systems in opal samples at Yucca Mountain are complicated by the incorporation of excess 234U at the time of mineral formation, resulting in reverse discordance of U-Pb ages. However, the 207PB/235U ages are much less affected by deviation from initial secular equilibrium and provide reliable ages of most silica deposits between 0.6 and 9.8 Ma. For chalcedony subsamples showing normal age discordance, these ages may represent minimum times of deposition. Typically, 207Pb/235U ages are consistent with the microstratigraphy in the mineral coating samples, such that the youngest ages are for subsamples from outer layers, intermediate ages are from inner layers, and oldest ages are from innermost layers. 234U and 230Th in most silica layers deeper in the coatings are in secular equilibrium with 238U, which is consistent with their old age and closed system behavior during the past -0.5 Ma. The ages for subsamples of silica layers from different microstratigraphic positions in individual calcite and silica coating samples collected from lithophysal cavities in the welded part of the Topopah Spring Tuff yield slow long-term average growth rates of 1 to 5 mm/Ma. These data imply that the deeper parts of the UZ at Yucca Mountain maintained long-term hydrologic stability over the past 10 Ma. despite significant climate variations. U-Pb ages for subsamples of silica layers from different microstratigraphic positions in individual calcite and silica coating samples collected from fractures in the shallower part of the UZ (welded part of the overlying Tiva Canyon Tuff) indicate larger long-term average growth rates up to 23 mm/Ma and an absence of recently deposited materials (ages of outermost layers are 3-5 Ma.). These differences between the characteristics of the coatings for samples from the shallower and deeper parts of the UZ may indicate that the nonwelded tuffs (PTn), located between the welded parts of the Tiva Canyon and Topopah Spring Tuffs, play an important role in moderating UZ flow.

U–Pb, Rb–Sr, and U-series isotope geochemistry of rocks and fracture minerals from the Chalk River Laboratories site, Grenville Province, Ontario, Canada

USGS Publications Warehouse

Neymark, Leonid; Peterman, Zell E.; Moscati, Richard J.; Thivierge, R. H.

2013-01-01

As part of the Geologic Waste Management Facility feasibility study, Atomic Energy of Canada Ltd. (AECL) is evaluating the suitability of the Chalk River Laboratories (CRL) site in Ontario, situated in crystalline rock of the southwestern Grenville Province, for the possible development of an underground repository for low- and intermediate-level nuclear waste. This paper presents petrographic and trace element analyses, U–Pb zircon dating results, and Rb–Sr, U–Pb and U-series isotopic analyses of gneissic drill core samples from the deep CRG-series characterization boreholes at the CRL site. The main rock types intersected in the boreholes include hornblende–biotite (±pyroxene) gneisses of granitic to granodioritic composition, leucocratic granitic gneisses with sparse mafic minerals, and garnet-bearing gneisses with variable amounts of biotite and/or hornblende. The trace element data for whole-rock samples plot in the fields of within-plate, syn-collision, and volcanic arc-type granites in discrimination diagrams used for the tectonic interpretation of granitic rocks.Zircons separated from biotite gneiss and metagranite samples yielded SHRIMP-RG U–Pb ages of 1472 ± 14 (2σ) and 1045 ± 6 Ma, respectively, in very good agreement with widespread Early Mesoproterozoic plutonic ages and Ottawan orogeny ages in the Central Gneiss Belt. The Rb–Sr, U–Pb, and Pb–Pb whole-rock errorchron apparent ages of most of the CRL gneiss samples are consistent with zircon U–Pb age and do not indicate substantial large-scale preferential element mobility during superimposed metamorphic and water/rock interaction processes. This may confirm the integrity of the rock mass, which is a positive attribute for a potential nuclear waste repository. Most 234U/238U activity ratios (AR) in whole rock samples are within errors of the secular equilibrium value of one, indicating that the rocks have not experienced any appreciable U loss or gain within the past 1 Ma. However, 234U/238U AR in fracture mineral samples collected down to borehole lengths of about 740 m deviate from the secular equilibrium value and 234U/238U model ages calculated for fracture mineral samples showing excess 234U range from 593 to 1415 ka, thus providing evidence of fracture flow in the associated bedrock during the past 1.5 Ma. Rare earth element patterns are variable in fracture-filling calcites and Fe oxides/hydroxides but are similar to those observed in associated whole-rock samples. The observed Ce anomalies are very small (CeN/CeN∗≈1">CeN/CeN∗≈1), do not vary with depth, and, therefore, do not contain evidence that the studied fracture minerals precipitated from oxidizing waters at the conceptual depth of a repository.

Continuously Monitoring the Micrometeorology of a Natural Cave System: Hollow Ridge Speleoclimatology

NASA Astrophysics Data System (ADS)

Kowalczk, A.; Gaffka, C.; Froelich, P.

2008-05-01

A study of cave microclimatology has been underway since October 2007 in a protected karst cave system near Marianna Florida. We are monitoring cave air, drip water and climatology at Hollow Ridge Cave to help calibrate isotopic and chemical paleoproxies incorporated into actively growing speleothems in Northwest Florida. Multiple monitoring stations positioned in the interior and above the overburden of this 1000 m long cave continuously record temperature (T), relative humidity (RH), barometric pressure (BP), drip rates (precipitation), acoustic airflow (wind) direction and velocity, 222Rn activities and CO2 concentrations. Air samples for 13CO2 analyses are collected periodically along the cave axis. Positively correlated 13CO2 vs. 1/ CO2 indicate soil gas (δ13C= -22 ‰) is the dominant CO2 source. Rn-222 is likely sourced from decay of 226Ra (U-series) in the limestone bedrock. In general, this cave inhales and exhales diurnally. All cave parameters reflect the intensity and longitudinal gradients of each breath modulated by frontal passages and seasonal changes. The diurnal amplitudes of T, RH, 222Rn and CO2 are highest nearest the entrance and almost disappear at the back of the cave, which mostly senses small amplitude frontal and seasonal changes. Radon-222 (20-340 dpm/L) and CO2 (400-1500 ppm) rise and fall coherently. Both gases are higher in the poorly ventilated portions of the cave, but each shows temporal and spatial patterns that reflect different sources - emanation from the enclosing limestone vs. soil gas and dripwater infusion from above. A flooding event due to a rise of the adjacent Chipola River inadvertently sealed the cave entrances, allowing 222Rn to grow in nearly to secular equilibrium (steady-state) in the air trapped inside the cave. Rn-222 peaked at 1200 dpm/L, over three-fold higher than previously measured, while CO2 peaked at 1400 ppm, similar to the highest CO2 values observed during normal conditions. As airflow was fully restricted, decay of 222Rn is balanced only by 222Rn emanation into the cave. Assuming 222Rn emanation into the cave is constant and represented by the secular equilibrium value, we use a simple radon- deficiency model to estimate air exchange rates (fractional tidal air volumes) and CO2 exhalation rates to compare wet (rainy) and dry periods. Daily air exchange rates vary from 18 to 26% of the cave volume. Radon/ CO2 ratios are four-times higher during wet periods than during dry periods, indicating stronger CO2 sources during dry periods. This suggests the cave ventilation system may be entraining soil gas CO2 from overhead fissures when the overlying soil cap is not waterlogged. This is counter to presumptions that wet periods with faster drips and more CO2 degassing from dripwater might increase cave air CO2 levels.

Secular Climate Change on Mars: An Update

NASA Astrophysics Data System (ADS)

Batterson, C. M.; Kahre, M. A.; Haberle, R. M.; Wilson, R. J.; Kahanpää, H.

2017-12-01

The stability of the South Polar Residual Cap (SPRC) has been in question since Leighton & Murray (1966) theorized that the cap is predominantly CO2 ice in solid-vapor equilibrium with the atmosphere. In 2001, Malin et al. reported a net loss of cap mass that Blackburn et al. (2010) calculated would sublime the SPRC by the end of the decade. Also in 2010, Haberle & Kahre analyzed Phoenix and VL2 pressure data to quantify the net loss of CO2 from the SPRC since the time of the Viking Missions. Though their loss estimates were consistent with Malin et al. (2001), the unclear accuracy of the pressure sensor and limited data available from Phoenix rendered their study inconclusive. This study modifies the process Haberle & Kahre (2010) use to quantify the change in atmospheric mass since VL2 and is improved by the known accuracy and stability of the MSL pressure sensor and its longer data set (two complete Mars Years). Modifications include excluding warm up errors in the MSL data, correcting for rover elevation changes, binning the data into hourly bins for daily averages, and excluding periods when both MSL and VL2 data are not simultaneously present when calculating annual means. An ensemble of Ames GCM simulations are used to define the offset that accounts for dynamical and physical differences between MSL and VL2. From these calculations we find an estimated net loss of 5 Pascals per Mars Decade of atmospheric CO2 , which is comparable to the year 2 MSL sensor accuracy ( 4 Pa). Given this, and the uncertain accuracy of the VL2 sensor, we see no compelling evidence for secular climate change. This result is consistent with Thomas et al's (2016) recent refinements in actual cap loss rates. However, since the Ames GCM runs at fairly coarse horizontal resolution we plan to use the higher-resolution GFDL FMS/FV3 GCM capable of resolving Gale Crater and its circulation to re-calculate the offset and obtain a more accurate loss/gain rate in the near future.

Variaciones seculares de período en las RR Lyrae de ω~Centauri

NASA Astrophysics Data System (ADS)

Marraco, H. G.; Milesi, G. E.

Utilizando 689 observaciones de 35 estrellas RR Lyrae del cúmulo globular ω Centauri hemos obtenido nuevas determinaciones de sus períodos y sus correspondientes variaciones seculares. Las observaciones fueron obtenidas de la literatura con la excepción de un grupo 66 determinaciones que se presentan por vez primera aquí. Utilizando el parámetro testigo σ descripto en Marraco & Muzzio (Publ. Astron. Soc. Pacific 92, 700, 1980), hemos realizado un ajuste bidimensional en P y β (donde β es la variación secular del período). Con este fin la totalidad de las 689 observaciones fueron llevadas a un sistema fotométrico común. Para esto se realizó un cuidadoso análisis de los numerosos errores en la identificación de las estrellas de las series de comparación. Los resultados de los ajustes bidimensionales fueron analizados utilizando técnicas de procesamiento de imágenes. Con este fin el parámetro de ajuste σ fue representado como función de P y β. En las imágenes resultantes se buscaron los mínimos y al menor de ellos se lo aceptó como período instantáneo verdadero y su variación secular β. La determinación precisa de cada parámetro se realizó mediante ajuste de gaussianas y se determinaron sus errores. A modo de ejemplo la variable #8 fue analizada en una matriz de 501 × 501 elementos representando el parámetro σ para valores comprendidos entre 0,521034 < P < 0,521534 dias y -150×10-10 < β < +150×10-10 dias/dia. El mejor período instantáneo (correspondiente a la época DJ=2.426.908) y su variación secular son P = 0,5212859±0,0000001 días y β 14,012±,010×10-10 días/día respectivamente. Con estos valores el parámetro testigo resulta σ= 0,127 . Si no se tiene en cuenta la variación secular del período y se busca aquél de mejor ajuste para β = 0, se obtiene P = 0,5212960 días, pero entonces el parámetro de ajuste resulta tan alto como σ = 0,23 .

Faith and HIV prevention: the conceptual framing of HIV prevention among Pentecostal Batswana teenagers

PubMed Central

2014-01-01

Background There is a huge interest by faith-based organizations (FBOs) in sub-Saharan Africa and elsewhere in HIV prevention interventions that build on the religious aspects of being. Successful partnerships between the public health services and FBOs will require a better understanding of the conceptual framing of HIV prevention by FBOS to access for prevention intervention, those concepts the churches of various denominations and their members would support or endorse. This study investigated the conceptual framing of HIV prevention among church youths in Botswana; - a country with one of the highest HIV prevalence in the world. Method Participants were 213 Pentecostal church members (67% female; age range 12 to 23 years; median age = 19 years). We engaged the participants in a mixed-method inductive process to collect data on their implicit framing of HIV prevention concepts, taking into account the centrality of religion concepts to them and the moderating influences of age, gender and sexual experience. After, we analysed the data using multi-dimensional scaling (MDS) and hierarchical cluster analysis (HCA) to map the ways the church youths framed HIV prevention. Results The findings suggest the church youth to conceptually frame their HIV prevention from both faith-oriented and secular-oriented perspectives, while prioritizing the faith-oriented concepts based on biblical teachings and future focus. In their secular-oriented framing of HIV prevention, the church youths endorsed the importance to learn the facts about HIV and AIDS, understanding of community norms that increased risk for HIV and prevention education. However, components of secular-oriented framing of HIV prevention concepts were comparatively less was well differentiated among the youths than with faith-oriented framing, suggesting latent influences of the church knowledge environment to undervalue secular oriented concepts. Older and sexually experienced church youths in their framing of HIV prevention valued future focus and prevention education less than contrasting peer cohorts, suggesting their greater relative risk for HIV infection. Conclusion A prospective HIV prevention intervention with the Pentecostal church youths would combine both faith and secular informed concepts. It also would need to take into account the ways in which these youth interpret secular-oriented health concepts in the context of their religious beliefs. PMID:24593140

"He Needs to Talk!": A Chaplain's Case Study of Nonreligious Spiritual Care.

PubMed

Nolan, Steve

2016-01-01

Chaplains have always worked with nonreligious people, but it is not always clear what is distinctive about their contribution. This case describes an episode of nonreligious spiritual care in order to explore the value of chaplaincy work with people who regard themselves as nonreligious. This case reports on work with a dying man and his family-wife, daughter, sister, and son-in-law-whose religion is secularized, but whose secularism is touched by the sacred.

Decadal-to-centennial-scale climate variability: Insights into the rise and fall of the Great Salt Lake

NASA Technical Reports Server (NTRS)

Mann, Michael E.; Lall, Upmanu; Saltzman, Barry

1995-01-01

We demonstrate connections between decadal and secular global climatic variations, and historical variations in the volume of the Great Salt Lake. The decadal variations correspond to a low-frequency shifting of storm tracks which influence winter precipitation and explain nearly 18% of the interannual and longer-term variance in the record of monthly volume change. The secular trend accounts for a more modest approximately 1.5% of the variance.

Understanding the Influence of the Pakistani Government in South Asia

DTIC Science & Technology

2010-11-01

that, “Jinnah, virtually alone, became the exponent of constitution making along secular lines. His vision involved the blending of multiple traditions...Hindu nor Sikh, but citizens of an all-embracing secular state, had little meaning for the vast majority who were now expected to adapt the Pakistani...to maintain ties to the United States Ayub Kahn began to move towards friendlier relations with China, a move that the United States would view as

[Secular trend of growth in Blumenau, Santa Catarina State].

PubMed

Soncini, Ana Silveira; Vargas, Deisi Maria; Arena, Mariana Garcia Lopes; Arena, Luiz Fernando Garcia Lopes

2011-01-01

Secular trend of growth refers to any change of the corporal size in determined population group in long periods of time. The objective of this work is to study the secular tendency of growth in natural height among recruits in Blumenau, Santa Catarina State, between the years of 1963 and 2007. This is a transversal, retrospective and analytical study. Young recruits, aged 18 to 20 were chosen as the population. A standardized database was used on individual records with the first 40 records of each year being selected. Data from 1963 to 2007 were collected and separated per decades. A margin of error not higher than 3.5% was used as a demonstration, which resulted in a sample of 600 individuals. The t-test was used to compare the averages of different decades. The results showed an increase of 7 cm in the height of the population in Blumenau in the last 50 years. The positive trend that is occurring in our country in the most recent evaluations can be attributed to better sanitary, economic and social conditions. The secular tendency of growth in height was positive in the municipality of Blumenau. It was found that the population increased 7 cm in the final height in the last 50 years with a growth rate of 0.14 cm/year or 1.4 cm/decade.

Secular Trends in Anthropometrics and Physical Fitness of Young Portuguese School-Aged Children.

PubMed

Costa, Aldo Matos; Costa, Mário Jorge; Reis, António Antunes; Ferreira, Sandra; Martins, Júlio; Pereira, Ana

2017-02-27

The purpose of this study was to analyze secular trends in anthropometrics and physical fitness of Portuguese children. A group of 1819 students (881 boys and 938 girls) between 10 and 11 years old was assessed in their 5th and 6th scholar grade throughout a 20 years' time-frame. ANCOVA models were used to analyze variations in anthropometrics (height, weight and body mass index) and physical fitness (sit and reach, curl-up, horizontal jump and sprint time) across four quinquennials (1993 - 1998; 1998 - 2003; 2003 - 2008; 2008 - 2013). Secular trends showed the presence of heavier boys and girls with higher body mass index in the 5th and 6th grade throughout the last 20 years. There was also a presence of taller girls but just until the 3rd quinquennial. Both boys and girls were able to perform better on the core strength test and sprint time but become less flexible over the years. Mean jumping performance remained unchanged for both genders. The present study provides novel data on anthropometrics and physical fitness trends over the last two decades in young Portuguese children, consistent with the results reported in other developed countries. Evidence for the start of a positive secular trend in body mass index and in some physical fitness components over the last two decades among the Portuguese youth.

Ten-Year Secular Trends in Youth Violence: Results From the Philadelphia Youth Risk Behavior Survey 2003-2013.

PubMed

Pool, Andrew C; Patterson, Freda; Luna, Ingrid Y; Hohl, Bernadette; Bauer, Katherine W

2017-04-01

Youth violence reduction is a public health priority, yet few studies have examined secular trends in violence among urban youth, who may be particularly vulnerable to numerous forms of violence. This study examines 10-year secular trends in the prevalence of violence-related behaviors among Philadelphia high school students. Repeated cross-sectional data were analyzed from 5 waves of the Philadelphia Youth Risk Behavior Survey (YRBS) from 2003 to 2013. Sex-specific multivariate regression models were used to examine secular trends in multiple types of violence, accounting for age, race/ethnicity, and sampling strategy. In 2013, the most prevalent violent behavior was physical fighting among boys (38.4%) and girls (32.7%). Among girls, the prevalence of sexual assault and suicide attempts declined between 2003 and 2013 (β = -0.13, p = .04 and β = -0.14, p = .007, respectively). Among boys, significant declines in carrying a weapon (β = -0.31, p < .001), carrying a gun (β = -0.16, p = .01), and physical fighting (β = -0.35, p = .001) were observed. Whereas the prevalence of some forms of violence stabilized or declined among Philadelphia youth during 2003-2013 time span, involvement in violence-related behaviors remains common among this population. Continued surveillance and evidence-based violence reduction strategies are needed to address violence among urban youth. © 2017, American School Health Association.

Secular resonances between bodies on close orbits II: prograde and retrograde orbits for irregular satellites

NASA Astrophysics Data System (ADS)

Li, Daohai; Christou, Apostolos A.

2017-09-01

In extending the analysis of the four secular resonances between close orbits in Li and Christou (Celest Mech Dyn Astron 125:133-160, 2016) (Paper I), we generalise the semianalytical model so that it applies to both prograde and retrograde orbits with a one-to-one map between the resonances in the two regimes. We propose the general form of the critical angle to be a linear combination of apsidal and nodal differences between the two orbits b_1 Δ π + b_2 Δ Ω, forming a collection of secular resonances in which the ones studied in Paper I are among the strongest. Test of the model in the orbital vicinity of massive satellites with physical and orbital parameters similar to those of the irregular satellites Himalia at Jupiter and Phoebe at Saturn shows that {>}20 and {>}40% of phase space is affected by these resonances, respectively. The survivability of the resonances is confirmed using numerical integration of the full Newtonian equations of motion. We observe that the lowest order resonances with b_1+|b_2|≤ 3 persist, while even higher-order resonances, up to b_1+|b_2|≥ 7, survive. Depending on the mass, between 10 and 60% of the integrated test particles are captured in these secular resonances, in agreement with the phase space analysis in the semianalytical model.

Arranged marriages, unlikely partners. How will their offspring look?

PubMed

Connors, E J

1995-05-01

In the new era of managed care, many religious healthcare providers are making "arranged marriages"--permanent partnerships with secular organizations. As they do so, the religious partners naturally ponder how best to ensure that their values permeate the new entity and thus prevail in later organizational "offspring." The organizations most likely to perpetuate their values are those with ethical corporate cultures and climates. These include religiously based healthcare providers, but such providers seem to lack confidence today in their ability to maintain culture and climate in newly formed partnerships. That may be fortunate because it prevents them from trying to impose their values on secular partners. Nevertheless, such values are often attractive to a prospective partner. A religious healthcare provider will need market leverage, as well as attractive values, to make a good "marriage." Even so, religious providers and secular investor-owned organizations are unlikely partners, because their motives and incentives differ radically. But religious providers can form solid relationships with secular, not-for-profit healthcare organizations if they take care to negotiate a binding commitment to maintain an ethical culture and climate. However, Catholic providers are at a disadvantage in such negotiations because Catholic religious congregations are unlikely to continue as owner-sponsors much beyond another decade. It is crucial that a stable source of influence develop to ensure a religious presence in the offspring of new partnerships.

Oxytocin binding sites in bovine mammary tissue

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

Zhao, Xin.

1989-01-01

Oxytocin binding sites were identified and characterized in bovine mammary tissue. ({sup 3}H)-oxytocin binding reached equilibrium by 50 min at 20{degree}C and by 8 hr at 4{degree}C. The half-time of displacement at 20{degree}C was approximately 1 hr. Thyrotropin releasing hormone, adrenocorticotropin, angiotensin I, angiotensin II, pentagastrin, bradykinin, xenopsin and L-valyl-histidyl-L-leucyl-L-threonyl-L-prolyl-L-valyl-L-glutamyl-L-lysine were not competitive. In the presence of 10 nM LiCl, addition of oxytocin to dispersed bovine mammary cells, in which phosphatidylinositol was pre-labelled, caused a time and dose-dependent increase in radioactive inositiol monophosphate incorporation. The possibility that there are distinct vasopressin receptors in bovine mammary tissue was investigated. ({sup 3}H)-vasopressinmore » binding reached equilibrium by 40 min at 20{degree}. The half-time of displacement at 20{degree}C was approximately 1 hr. The ability of the peptides to inhibit ({sup 3}H)-vasopressin binding was: (Thr{sup 4},Gly{sup 7})-oxytocin > Arg{sup 8}-vasopressin > (lys{sup 8})-vasopressin > (Deamino{sup 1},D-arg{sup 8})-vasopressin > oxytocin > d (CH{sub 2}){sub 5}Tyr(Me)AVP.« less

BLT-EC (Breach, Leach and Transport-Equilibrium Chemistry) data input guide. A computer model for simulating release and coupled geochemical transport of contaminants from a subsurface disposal facility

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

MacKinnon, R.J.; Sullivan, T.M.; Kinsey, R.R.

1997-05-01

The BLT-EC computer code has been developed, implemented, and tested. BLT-EC is a two-dimensional finite element computer code capable of simulating the time-dependent release and reactive transport of aqueous phase species in a subsurface soil system. BLT-EC contains models to simulate the processes (container degradation, waste-form performance, transport, chemical reactions, and radioactive production and decay) most relevant to estimating the release and transport of contaminants from a subsurface disposal system. Water flow is provided through tabular input or auxiliary files. Container degradation considers localized failure due to pitting corrosion and general failure due to uniform surface degradation processes. Waste-form performancemore » considers release to be limited by one of four mechanisms: rinse with partitioning, diffusion, uniform surface degradation, and solubility. Transport considers the processes of advection, dispersion, diffusion, chemical reaction, radioactive production and decay, and sources (waste form releases). Chemical reactions accounted for include complexation, sorption, dissolution-precipitation, oxidation-reduction, and ion exchange. Radioactive production and decay in the waste form is simulated. To improve the usefulness of BLT-EC, a pre-processor, ECIN, which assists in the creation of chemistry input files, and a post-processor, BLTPLOT, which provides a visual display of the data have been developed. BLT-EC also includes an extensive database of thermodynamic data that is also accessible to ECIN. This document reviews the models implemented in BLT-EC and serves as a guide to creating input files and applying BLT-EC.« less

Thermal And Dynamical Histories Of Saturn's Satellites: Evidence For The Presence Of Short Lived Radioactive Isotopes

NASA Astrophysics Data System (ADS)

Johnson, Torrence V.; Castillo-Rogez, Julie C.; Matson, Dennis L.

2008-04-01

Recent observations of Saturn's satellite system from the Cassini/Huygens mission present serious challenges to understanding the current dynamical states and thermal histories of these icy bodies using conventional thermal models that use long lived radioactive isotopes (LLRI) as the primary heat sources. In particular, the most distant of the regular satellites, Iapetus, is in synchronous rotation about Saturn, implying relatively high levels of dissipation of tidal energy. However, it retains a highly non-equilibrium, oblate spheroid, shape, implying a thick, cold, mechanically rigid outer layer or lithosphere. Thermal history models of Iapetus that successfully explain these apparently contradictory characteristics require significant heating early in the satellite's history from short lived radioactive isotopes (SRLI), particularly Al, implying a formation time for Iapetus of between 2.5 and 5 Myr after the formation of Calcium26 Aluminum Inclusions (CAIs) [l]. The characteristics of the other icy satellites in the system are consistent with this formation time, and the current thermal geyser activity on the more silicate-rich satellite Enceladus may be related to such an early heating event. A consequence of these early formation time models is that the early crust of Iapetus is too thin and weak to retain large impact basin topography until about 100 Myr after formation, and despinning to synchronous rotation might have occurred from 200-900 Myr after formation. This chronology is consistent with the formation of the large impact basins observed on Iapetus' surface by the `late heavy bombardment' or `lunar cataclysm' event recorded in the dating of samples from the Moon at 3900 Ma.

Atlas of Secular Light Curves of Comets

NASA Astrophysics Data System (ADS)

Ferrin, Ignacio

2007-12-01

We have completed work on the secular light curves of 30 periodic and non-periodic comets. The objectives and approach of this project has been explained in Ferrin (Icarus, 178, 493-516, 2005). Each comet requires 2 plots. The time plot shows the reduced (to Δ = 1 AU) magnitude of the comet as a function of time, thus displaying the brightness history of the object. The log plot is a reflected double log plot. The reflection takes place at R=1 AU, to allow the determination of the absolute magnitude by extrapolation. 22 photometric parameters are measured from the plots, most of them new. The plots have been collected in a document that constitutes "The Atlas". We have defined a photometric age, P-AGE, that attempts to measure the age of a comet based on its activity. P-AGE has been scaled to human ages to help in its interpretation. We find that comets Hale-Bopp and 29P/SW 1, are baby comets (P-AGE < 3 comet years), while 107P, 162P and 169P are methuselah comets (P-AGE > 100 cy). The secular light curve of 9P/Tempel 1 exhibits sublimation due to H2O and due to CO. Comet 67P/Churyumov-Gerasimento to be visited by the Rossetta spacecraft in 2014 exhibits a photometric anomaly. Comet 65P/Gunn exhibits a lag in maximum brightness of LAG = + 254 days after perihelion. We suggest that the pole is pointing to the sun at that time. The secular light curves will be presented and a preliminary interpretation will be advanced. The secular light curves present complexity beyond current understanding. The observations described in this work were carried out at the National Observatory of Venezuela (ONV), managed by the Center for Research in Astronomy (CIDA), for the Ministry of Science and Technology (MinCyT).

Clearing Residual Planetesimals by Sweeping Secular Resonances in Transitional Disks: A Lone-planet Scenario for the Wide Gaps in Debris Disks around Vega and Fomalhaut

NASA Astrophysics Data System (ADS)

Zheng, Xiaochen; Lin, Douglas N. C.; Kouwenhoven, M. B. N.; Mao, Shude; Zhang, Xiaojia

2017-11-01

Extended gaps in the debris disks of both Vega and Fomalhaut have been observed. These structures have been attributed to tidal perturbations by multiple super-Jupiter gas giant planets. Within the current observational limits, however, no such massive planets have been detected. Here we propose a less stringent “lone-planet” scenario to account for the observed structure with a single eccentric gas giant and suggest that clearing of these wide gaps is induced by its sweeping secular resonance. With a series of numerical simulations, we show that the gravitational potential of the natal disk induces the planet to precess. At the locations where its precession frequency matches the precession frequency the planet imposes on the residual planetesimals, their eccentricity is excited by its resonant perturbation. Due to the hydrodynamic drag by the residual disk gas, the planetesimals undergo orbital decay as their excited eccentricities are effectively damped. During the depletion of the disk gas, the planet’s secular resonance propagates inward and clears a wide gap over an extended region of the disk. Although some residual intermediate-size planetesimals may remain in the gap, their surface density is too low to either produce super-Earths or lead to sufficiently frequent disruptive collisions to generate any observable dusty signatures. The main advantage of this lone-planet sweeping-secular-resonance model over the previous multiple gas giant tidal truncation scenario is the relaxed requirement on the number of gas giants. The observationally inferred upper mass limit can also be satisfied provided the hypothetical planet has a significant eccentricity. A significant fraction of solar or more massive stars bear gas giant planets with significant eccentricities. If these planets acquired their present-day kinematic properties prior to the depletion of their natal disks, their sweeping secular resonance would effectively impede the retention of neighboring planets and planetesimals over a wide range of orbital semimajor axes.

Response of trapped particles to a collapsing dipole moment.

NASA Technical Reports Server (NTRS)

Heckman, H. H.; Lindstrom, P. J.

1972-01-01

Particle motion in the secularly varying geomagnetic field is investigated in terms of a dipolar magnetic field with decreasing magnetic moment M. For dM/dt equal to the rate of decay of the earth's dipole component, we find there is drift in B-L space, resulting in an inward drift of particles accompanied with increased energy and unidirectional intensity. Secular variation of the geomagnetic field appears to be a dominant mechanism for radial drift in the inner radiation belt.

A Numerical Method for Predicting Rayleigh Surface Wave Velocity in Anisotropic Crystals (Postprint)

DTIC Science & Technology

2017-09-05

generalized version of the equations are very difficult to derive, even in symbolic math languages such as Mathematica. As a result, the equations are...formalism, Math . Mech. Solids 9 (1) (2004) 5–15. [8] M. Destrade, The explicit secular equation for surface acoustic waves in monoclinic elastic crystals...Q. J. Mech. Appl. Math . 55 (2) (2002) 297–311. [10] D. Taylor, Surface waves in anisotropic media: the secular equation and its numerical solution

The joint US/UK 1990 epoch world magnetic model

NASA Technical Reports Server (NTRS)

Quinn, John M.; Coleman, Rachel J.; Peck, Michael R.; Lauber, Stephen E.

1991-01-01

A detailed summary of the data used, analyses performed, modeling techniques employed, and results obtained in the course of the 1990 Epoch World Magnetic Modeling effort are given. Also, use and limitations of the GEOMAG algorithm are presented. Charts and tables related to the 1990 World Magnetic Model (WMM-90) for the Earth's main field and secular variation in Mercator and polar stereographic projections are presented along with useful tables of several magnetic field components and their secular variation on a 5-degree worldwide grid.

Relative Orbit Elements for Satellites in Elliptical Orbits

DTIC Science & Technology

2010-03-01

studied subject; many important contributions to the study were made before and during the dawn of the Space Age . In fact, the most celebrated...accomplishments of the Space Age would not have been possible without a good understanding of relative satellite motion. The Apollo astronauts could not... secular terms (containing t and 2t ) in the y-direction and mixed- secular terms (of the form  1 2 3sint t   ) in all three directions. In 1999

Prediction of secular acceleration of axial rotation of Mars

NASA Astrophysics Data System (ADS)

Barkin, Yu. V.

2009-04-01

Secular motion of the Earth pole and non-tidal acceleration of its diurnal rotation have obtained rather precise explanation with the help of simple one-point model of the directed transport of fluid masses from a southern hemisphere in northern hemisphere with the general direction, given by geocentric axis OP directed to pole P with coordinates 700N, 10403 E[1]. The another generalized model represents a system of two material points with masses m2 and m1, located on surface of the Earth at poles of geocentric axis OP. Masses are linearly changed in the time with velocities [2]: ṁ2 = 0.179 × 1015kg/yrand ṁ1 = 0.043 × 1015kg/yr. A reduction of fluid masses of the appropriate thin spherical layer of the Earth correspond to secular increasing of masses of model points. The specified model has allowed to explain values of fundamental geodynamic parameters observably and determined during decades: a direction and velocity of drift of a pole of the Earth; value of non-tidal acceleration of axial rotation; to explain a secular variations of coefficients of the second, third, fourth, sixth and eighth zonal harmonics of a geopotential; coefficients of secular changes of a surface of ocean for the last approximately 150 years; a direction of secular drift of a geocenter and other planetary phenomena [3]. The role of the angular momentum of redistributed masses of the Earth in rotation of the Earth appeared not essential at the given stage of researches. On the essence the offered model has semi-empirical character as it bases on values of velocities of change of masses of points and the given position of axis OP. For their determination and estimations the part of the observant data was used, and other parameters were designed under analytical formulas. The obtained results have precisely confirmed competency and affectivity of geodynamic model [4] about existence of secular drift of a liquid core along radial direction OP with velocity about 2.6 cm/yr in the northern direction to Taimyr peninsula. Thus the gravitational attraction of superfluous mass of the core (19 % from the Earth mass) causes secular asymmetric inversion tide [2] of fluids which effectively manages to be modeled by two points with variable masses. In the given work the attempt to construct a similar model of the directed secular redistribution of fluid masses of Mars from a southern hemisphere in northern is undertaken with the purpose of an explanation of observably tendencies in redistribution of masses between hemispheres and with the purpose of a prediction of the new phenomena in its rotary motion. The hypothetical assumption is made, that secular redistribution of fluid masses from a southern hemisphere in northern hemisphere of Mars mainly is determined by areocentric axis OP directed to the pole P with coordinates 570N, 820 E (as is known in this direction the centre of mass of Mars relatively the centre of a figure on 2.8 km is displaced). Material points with masses m2 and m1 settle down at poles of geocentric axis OP on a surface of Mars, and their masses change linearly in the time with velocities [5]: ṁ2 = 0.402 × 1015kg/yr and ṁ1 = 0.257 × 1015kg/yr. The given modeling characteristics correspond to prospective secular variations of coefficients of the second and third zonal harmonics of gravitational potential of Mars: J˙2= - 57.0 × 10-11 1/yr and ˙J3 = -4.94 × 10-11 1/yr, more less agreed for today with the data of observations (Dehant, private communication, 2008) [6]. Let's emphasize, that the discussed phenomena of asymmetry of hemispheres, intensity of inversion processes, and bipolarity and inversion of all structures of Mars much more expressive, than at the Earth. Therefore we in the right to expect the greater efficiency in application of geodynamic model and more significant secular effects in rotation of Mars in comparison with the Earth. The constructed model has allowed to estimate non-tidal acceleration of axial rotation which as it would be possible to expect, essentially surpasses the similar characteristic of rotation of the Earth. The obtained result means, that angular velocity of Mars in present period increases on the law r = (0.708821808000+ 0.000000001038×t) × 10-4 1/s, here t - in years. It is possible assume that the estimation of acceleration can be obtained directly on the basis of the data of observations in the nearest years. Velocity of secular change of duration of day for Mars (LOD) thus can make significant value about -0.0903 ms/yr, that considerably surpasses similar value for non-tidal acceleration of the Earth (-0.006 ms/yr). The ratio of positive acceleration of the Earth rotation ṙ to its angular velocity ? makes ṙ•? = (6.9± 1.7) × 10-11 1/yr[7]. In case of Mars the estimation of acceleration was carried out under the formula [8]: ṙ/ ? = -Ċ• C -á¹ °• G ?-Ċ• C = 103.8 × 10-11 1/yr. We here have neglected by an influence of secular change of the axial angular momentum of fluid masses (atmospheric and underground) of Marsá¹ °. As shown in other my report on EGU GA 2009 in case of the Earth the total angular momentum of fluids really is small and within the limits of mistakes can be accepted equal to zero. In the case of Mars we the same as and in case of the Earth, expect of secular change of the angular momentum of Mars and change of global superrotation of its atmosphere which, at least, in part, will be compensated by the angular momentum of fluids. Thus, expected non-tidal acceleration of axial rotation of Mars can be at 10-15 times more those, but observably by astronomical methods, for the Earth. Certainly, the estimations obtained here are preliminary and the phenomena discussed here require more detailed studying with using of new data of precision observations. First of all it is important to obtain the specified values of secular variations ˙ J2 and ˙ J3. In case of the Earth the tidal deceleration of daily rotation of the Earth essentially surpasses non-tidal acceleration (35 %) which as shown the author is caused by the directed redistribution of fluid masses of the Earth, in turn caused by polar drift of the centre of mass of the liquid core of the Earth to the north [1]. In case of Mars the opposite picture is expected. It is quite possible, as show the executed estimations, that tidal deceleration of axial rotation of Mars much less than its positive acceleration caused by global dynamics of shells (the core and mantle). And it means, that as against the Earth in axial rotation of Mars in the present epoch an acceleration, instead of deceleration of rotation should be observed. References [1] Barkin Yu.V. (2001) Explanation and prediction of the secular variations of the Earth rotation, geopotential, force of gravity and geocenter drift. Proceedings of International Conference «AstroKazan-2001». Astronomy and geodesy in new millennium (24-29 September 2001), Kazan State University: Publisher «DAS», pp. 73-79. [2] Barkin Yu.V. (2007) To an explanation of non-tidal acceleration of the Earth diurnal rotation and secular trend of its pole. Proceedings of IUGG XXIV General Assembly, Perugia, Italy 2007: Earth: Our Changing Planet (Perugia, Italy, July 2-13, 2007), (G) - IAG, GS003, p. 3799. www. iugg2007perugia.it. [3] Barkin Yu.V. (2007) Celestial geodynamics and solution of the fundamental problems of geodesy, gravimetry and geophysics. Proceedings of IUGG XXIV General Assembly, Perugia, Italy 2007: Earth: Our Changing Planet (Perugia, Italy, July 2-13, 2007), (S) - IASPEI, JSS011, p. 2149. www. iugg2007perugia.it. [4] Barkin Yu.V. (2002) Explanation of endogenous activity of planets and satellites and its cyclicity. Izvestia cekzii nauk o Zemle. Rus. Acad. of Nat. Sciences, Issue 9, December 2002, M.: VINITI, pp. 45-97. In Russian.

Radionuclide calorimeter system

DOEpatents

Donohoue, Thomas P.; Oertel, Christopher P.; Tyree, William H.; Valdez, Joe L.

1991-11-26

A circuit for measuring temperature differentials in a calorimeter is disclosed. The temperature differential between the reference element and sample element containing a radioactive material is measured via a wheatstone bridge arrangement of thermistors. The bridge is driven with an alternating current on a pulsed basis to maintain the thermal floor of the calorimeter at a low reference value. A lock-in amplifier connected to the bridge phase locks a signal from the bridge to the input pulsed AC signal to provide a DC voltage. The DC voltage is sampled over time and provided to a digital computer. The digital computer, using curve fitting algorithms, will derive a function for the sample data. From the function, an equilibrium value for the temperature may be calculated.

Radionuclide calorimeter system

DOEpatents

Donohoue, T.P.; Oertel, C.P.; Tyree, W.H.; Valdez, J.L.

1991-11-26

A circuit for measuring temperature differentials in a calorimeter is disclosed. The temperature differential between the reference element and sample element containing a radioactive material is measured via a Wheatstone bridge arrangement of thermistors. The bridge is driven with an alternating current on a pulsed basis to maintain the thermal floor of the calorimeter at a low reference value. A lock-in amplifier connected to the bridge phase locks a signal from the bridge to the input pulsed AC signal to provide a DC voltage. The DC voltage is sampled over time and provided to a digital computer. The digital computer, using curve fitting algorithms, will derive a function for the sample data. From the function, an equilibrium value for the temperature may be calculated. 7 figures.

Spatial patterns and secular trends in human leishmaniasis incidence in Morocco between 2003 and 2013.

PubMed

Sadeq, Mina

2016-05-11

Few studies on spatial patterns or secular trends in human leishmanias have been conducted in Morocco. This study aimed to examine spatial patterns and trends associated with the human leishmaniasis incidence rate (HLIR) at the province/prefecture level between 2003 and 2013 in Morocco. Only the available published country data on the HLIR between 2003 and 2013, from the open access files of the Ministry of Health, were used. Secular trends were examined using Kendall's rank correlation. An exploratory spatial data analysis was also conducted to examine the spatial autocorrelation (Global Moran's I and local indicator of spatial association [LISA]), and spatial diffusion at the province/prefecture level. The influence of various covariates (poverty rate, vulnerability rate, population density, and urbanization) on the HLIR was tested via spatial regression (ordinary least squares regression). At the country level, no secular variation was observed. Poisson annual incidence rate estimates were 13 per 100 000 population (95 % CI = 12.9-13.1) for cutaneous leishmaniasis (CL) and 0.4 per 100 000 population (95 % CI = 0.4-0.5) for visceral leishmaniasis (VL). The available data on HLIR were based on combined CL and VL cases, however, as the CL cases totally outnumbered the VL ones, HLIR may be considered as CL incidence rate. At the provincial level, a secular increase in the incidence rate was observed in Al Hoceima (P = 0.008), Taounate (P = 0.04), Larache (P = 0.002), Tétouan (P = 0.0003), Khenifra (P = 0.008), Meknes (P = 0.03), and El Kelaa (P = 0.0007), whereas a secular decrease was observed only in the Chichaoua province (P = 0.006). Even though increased or decreased rate was evident in these provinces, none of them showed clustering of leishmaniasis incidence. Significant spatial clusters of high leishmaniasis incidence were located in the northeastern part of Morocco, while spatial clusters of low leishmaniasis incidence were seen in some northwestern and southern parts of Morocco; there was spatial randomness in the remaining parts of the country. Significant clustering was seen from 2005 to 2013, during which time the Errachidia province was a permanent 'hot spot'. Global Moran's I increased from 0.2844 (P = 0.006) in 2005 to 0.5886 (P = 0.001) in 2011, and decreased to 0.2491 (P = 0.004) in 2013. It was found that only poverty had an effect on the HLIR (P = 0.0003), contributing only 23 % to this (Adjusted R-squared = 0.226). Localities showing either secular increase in human leishmaniasis or significant clustering have been identified, which may guide decision-making as to where to appropriately allocate funding and implement control measures. Researchers are also urged to undertake further studies focusing on these localities.

Conceptual model analysis of interaction at a concrete-Boom Clay interface

NASA Astrophysics Data System (ADS)

Liu, Sanheng; Jacques, Diederik; Govaerts, Joan; Wang, Lian

In many concepts for deep disposal of high-level radioactive waste, cementitious materials are used in the engineered barriers. For example, in Belgium the engineered barrier system is based on a considerable amount of cementitious materials as buffer and backfill in the so-called supercontainer embedded in the hosting geological formation. A potential hosting formation is Boom Clay. Insight in the interaction between the high-pH pore water of the cementitious materials and neutral-pH Boom Clay pore water is required. Two problems are quite common for modeling of such a system. The first one is the computational cost due to the long timescale model assessments envisaged for the deep disposal system. Also a very fine grid (in sub-millimeter), especially at interfaces has to be used in order to accurately predict the evolution of the system. The second one is whether to use equilibrium or kinetic reaction models. The objectives of this paper are twofold. First, we develop an efficient coupled reactive transport code for this diffusion-dominated system by making full use of multi-processors/cores computers. Second, we investigate how sensitive the system is to chemical reaction models especially when pore clogging due to mineral precipitation is considered within the cementitious system. To do this, we selected two portlandite dissolution models, i.e., equilibrium (fastest) and diffusion-controlled model with precipitation of a calcite layer around portlandite particles (diffusion-controlled dissolution). The results show that with shrinking core model portlandite dissolution and calcite precipitation are much slower than with the equilibrium model. Also diffusion-controlled dissolution smooths out dissolution fronts compared to the equilibrium model. However, only a slight difference with respect to the clogging time can be found even though we use a very small diffusion coefficient (10-20 m2/s) in the precipitated calcite layer.

Secularization versus religious revival in Eastern Europe: Church institutional resilience, state repression and divergent paths.

PubMed

Northmore-Ball, Ksenia; Evans, Geoffrey

2016-05-01

Despite continuing for over two decades, the debate about the nature of the trends in religiosity in post-Communist Eastern Europe remains unresolved: some arguing that these countries are undergoing the same process of secularization as the West, while others insist that the entire region is experiencing a religious revival. Using national sample surveys from the early 1990s to 2007 to examine the change in demographic predictors of religiosity, we show that Catholic and Orthodox countries are experiencing different trends, the first group displaying evidence of secularization and the second of revival, and that these two different trends are likely to derive from the legacies of state repression and the differing abilities of the churches to resist such repression. We argue that the current literature has thus taken a mistakenly general approach, and that the post-Communist region consists of at least two distinct groups of societies with different trends in religiosity. Copyright © 2016. Published by Elsevier Inc.

The women preachers of the secular state: the politics of preaching at the intersection of gender, ethnicity and sovereignty in Turkey.

PubMed

Tütüncü, Fatma

2010-01-01

This article analyzes the politics of preaching in Turkey in the last decade by focusing on the appointment of women as preachers and vice-muftis by the Turkish Presidency of Religious Affairs (Diyanet), a state institution established for the protection of secular foundations through religious service. It asks what happens when women wearing headscarves become civil servants and give religious guidance in a secular state, which prohibits headscarves in public offices and schools. It shows that the context, the use and the interlocutors of preaching make ordinary religious activity a complicated political practice that interacts with gender, ethnicity and state sovereignty. It argues that exceptional integration of headscarved women into public offices would seem to be an achievement given the long lasting political activism of women over the headscarf, but in the final analysis it serves the sovereign power of the state, which aims to absorb both Islamist and Kurdish challenges by mobilizing women preachers.

Secular perihelion advances of the inner planets and asteroid Icarus

NASA Astrophysics Data System (ADS)

Wilhelm, Klaus; Dwivedi, Bhola N.

2014-08-01

A small effect expected from a recently proposed gravitational impact model (Wilhelm et al., 2013) is used to explain the remaining secular perihelion advance rates of the planets Mercury, Venus, Earth, Mars, and the asteroid (1566) Icarus-after taking into account the disturbances related to Newton’s Theory of Gravity. Such a rate was discovered by Le Verrier (1859) for Mercury and calculated by Einstein (1915, 1916) in the framework of his General Theory of Relativity (GTR). Accurate observations are now available for the inner Solar System objects with different orbital parameters. This is important, because it allowed us to demonstrate that the quantitative amount of the deviation from an 1/r potential is-under certain conditions-only dependent on the specific mass distribution of the Sun and not on the characteristics of the orbiting objects and their orbits. A displacement of the effective gravitational from the geometric centre of the Sun by about 4400 m towards each object is consistent with the observations and explains the secular perihelion advance rates.

Orbital period study of the Algol-type eclipsing binary system TW Draconis

NASA Astrophysics Data System (ADS)

Qian, S. B.; Boonrucksar, S.

2002-10-01

The century-long times of light minimum of the Algol-type eclipsing binary star, TW Dra (BD +64°1077, Sp A5V+K2III), are investigated by considering a new pattern of period change. Two sudden period increases and two successive period decreases are discovered to superimpose on a rapid secular increase (d P/d t=+4.43×10 -6 days/year). The secular increase may be caused by a dynamical mass transfer from the secondary to the primary component (d m/d t=6.81×10 -7 M ⊙/year) that is in agreement with the semi-detached configuration of the system and with the existence of a hot spot and a gaseous stream in the binary system. The irregular period jumps superimposed on the secular increase can be explained by the structure variation of the K2-type giant via instabilities of the outer convective layer or via magnetic activity cycles.

The Effect of CO2 Ice Cap Sublimation on Mars Atmosphere

NASA Technical Reports Server (NTRS)

Batterson, Courtney

2016-01-01

Sublimation of the polar CO2 ice caps on Mars is an ongoing phenomenon that may be contributing to secular climate change on Mars. The transfer of CO2 between the surface and atmosphere via sublimation and deposition may alter atmospheric mass such that net atmospheric mass is increasing despite seasonal variations in CO2 transfer. My study builds on previous studies by Kahre and Haberle that analyze and compare data from the Phoenix and Viking Landers 1 and 2 to determine whether secular climate change is happening on Mars. In this project, I use two years worth of temperature, pressure, and elevation data from the MSL Curiosity rover to create a program that allows for successful comparison of Curiosity pressure data to Viking Lander pressure data so a conclusion can be drawn regarding whether CO2 ice cap sublimation is causing a net increase in atmospheric mass and is thus contributing to secular climate change on Mars.

Evaluation of the 1985-1990 IGRF secular variation candidates

USGS Publications Warehouse

Cain, J.C.; Kluth, C.

1987-01-01

The IGRF secular variation model for 1985-1990 was adopted by the International Association of Geomagnetism and Aeronomy at its Prague meeting in August 1985 as an average of the three candidate models submitted to the committee. We compared the three models at epoch 1985.0 against each other and against a new model based on observatory data available as of July 1, 1985. These comparisons showed that one of the three candidate models disagreed more with the other two and our model, especially in the eastern Pacific. None of the candidate models was seen to respond to a change in the secular variation of the vertical component that appears to have taken place most strongly in the western Pacific area since 1982. The lack of satellite data was seen to be a significant handicap towards prediction of the field change over most of the Earth's surface, especially the southern oceans. Maximum errors of any model are estimated to be of the order of 80 nT a-1. ?? 1987.

Statistical nature of infrared dynamics on de Sitter background

NASA Astrophysics Data System (ADS)

Tokuda, Junsei; Tanaka, Takahiro

2018-02-01

In this study, we formulate a systematic way of deriving an effective equation of motion(EoM) for long wavelength modes of a massless scalar field with a general potential V(phi) on de Sitter background, and investigate whether or not the effective EoM can be described as a classical stochastic process. Our formulation gives an extension of the usual stochastic formalism to including sub-leading secular growth coming from the nonlinearity of short wavelength modes. Applying our formalism to λ phi4 theory, we explicitly derive an effective EoM which correctly recovers the next-to-leading secularly growing part at a late time, and show that this effective EoM can be seen as a classical stochastic process. Our extended stochastic formalism can describe all secularly growing terms which appear in all correlation functions with a specific operator ordering. The restriction of the operator ordering will not be a big drawback because the commutator of a light scalar field becomes negligible at large scales owing to the squeezing.

Intergenerational transmission of religious beliefs and practices and the reduction of adolescent delinquency in urban Thailand.

PubMed

Chamratrithirong, Aphichat; Miller, Brenda A; Byrnes, Hilary F; Rhucharoenpornpanich, Orratai; Cupp, Pamela K; Rosati, Michael J; Fongkaew, Warunee; Atwood, Katharine A; Todd, Michael

2013-02-01

This study examines the intergenerational transmission of family religion as measured by parent's and adolescent's beliefs and practices in Buddhism, and its relation to delinquent behaviors among early adolescents in Thailand. The data set is from the Thai Family Matters Project 2007, a representative sample of 420 pairs of parents and teens in Bangkok. A structural equation model is employed for the analysis. The intergenerational transmission and the direct and indirect association between parents' and adolescents' beliefs and practices in Buddhism and adolescents' minor and serious delinquent behaviors are revealed to be significant, controlling for secular parental monitoring. Spirituality within the family can play an important role in preventing delinquency among early adolescents. Policies in the areas related to family empowerment and delinquency prevention may need to consider integrating both secular and non-secular program inputs in their implementation design. Copyright © 2012 The Foundation for Professionals in Services for Adolescents. Published by Elsevier Ltd. All rights reserved.

Mental Health Treatment Involvement and Religious Coping among African American, Hispanic, and White Veterans of the Wars of Iraq and Afghanistan

PubMed Central

Greenawalt, David S.; Tsan, Jack Y.; Kimbrel, Nathan A.; Meyer, Eric C.; Kruse, Marc I.; Tharp, David F.; Gulliver, Suzy Bird; Morissette, Sandra B.

2011-01-01

Although racial/ethnic differences have been found in the use of mental health services for depression in the general population, research among Veterans has produced mixed results. This study examined racial/ethnic differences in the use of mental health services among 148 Operation Enduring/Iraqi Freedom (OEF/OIF) Veterans with high levels of depression and posttraumatic stress disorder (PTSD) symptoms and evaluated whether religious coping affected service use. No differences between African American, Hispanic, and Non-Hispanic white Veterans were found in use of secular mental health services or religious counseling. Women Veterans were more likely than men to seek secular treatment. After controlling for PTSD symptoms, depression symptom level was a significant predictor of psychotherapy attendance but not medication treatment. African American Veterans reported higher levels of religious coping than whites. Religious coping was associated with participation in religious counseling, but not secular mental health services. PMID:21785719

The steady part of the secular variation of the Earth's magnetic field

NASA Technical Reports Server (NTRS)

Bloxham, Jeremy

1992-01-01

The secular variation of the Earth's magnetic field results from the effects of magnetic induction in the fluid outer core and from the effects of magnetic diffusion in the core and the mantle. Adequate observations to map the magnetic field at the core-mantle boundary extend back over three centuries, providing a model of the secular variation at the core-mantle boundary. Here we consider how best to analyze this time-dependent part of the field. To calculate steady core flow over long time periods, we introduce an adaptation of our earlier method of calculating the flow in order to achieve greater numerical stability. We perform this procedure for the periods 1840-1990 and 1690-1840 and find that well over 90 percent of the variance of the time-dependent field can be explained by simple steady core flow. The core flows obtained for the two intervals are broadly similar to each other and to flows determined over much shorter recent intervals.

When was secularization? Dating the decline of the British churches and locating its cause.

PubMed

Bruce, Steve; Glendinning, Tony

2010-03-01

Dating the decline of Christianity in Britain has a vital bearing on its explanation. Recent work by social historians has challenged the sociological view that secularization is due to long-term diffuse social processes by asserting that the churches remained stable and popular until the late 1950s and that the causes of decline lie in the social and cultural changes associated with the 1960s. We challenge this interpretation of the evidence. We also note that much of the decline of the churches is explained not by adult defection but by a failure to keep children in the faith. Given the importance of parental homogamy for the successful transmission of religious identity, the causes of decline in one generation may well lie in the experiences of the previous generation. We focus on the disruptive effects of the 1939-45 war on family formation and use survey data to argue for a staged model of decline that is compatible with the conventional gradual view of secularization.

The use of MAGSAT data to determine secular variation.

USGS Publications Warehouse

Cain, J.C.; Frayser, J.; Muth, L.; Schmitz, D.

1983-01-01

A combined spatial and secular variation model of the geomagnetic field, labeled M061581, is derived from a selection of MAGSAT data. Secular variation (SV) data computed from linear fits to midnight hourly values from 19 magnetic observatories were also included in the analysis but were seen to have little effect on the model. The SV patterns from this new model are compared with those from the 1980 IGRF and with those for 1970 computed by the DGRF and with the 1960 patterns computed using the GSFC(12/66) model. Most of the features of the M061581 are identical in location and level with those of the 1980 IGRF. Together they confirm that the reversals in sign of field change seen over Asia and North America between 1965 and 1975 are reverting to the pre-1965 states. The M061581 model gives -32 nT/yr for the dipole decay rate, larger than the 70% increase already reported since 1965. -Authors

Parental age and offspring mortality: Negative effects of reproductive ageing may be counterbalanced by secular increases in longevity.

PubMed

Barclay, Kieron; Myrskylä, Mikko

2018-07-01

As parental ages at birth continue to rise, concerns about the effects of fertility postponement on offspring are increasing. Due to reproductive ageing, advanced parental ages have been associated with negative health outcomes for offspring, including decreased longevity. The literature, however, has neglected to examine the potential benefits of being born at a later date. Secular declines in mortality mean that later birth cohorts are living longer. We analyse mortality over ages 30-74 among 1.9 million Swedish men and women born 1938-60, and use a sibling comparison design that accounts for all time-invariant factors shared by the siblings. When incorporating cohort improvements in mortality, we find that those born to older mothers do not suffer any significant mortality disadvantage, and that those born to older fathers have lower mortality. These findings are likely to be explained by secular declines in mortality counterbalancing the negative effects of reproductive ageing.

Antarctic Analog for Dilational Bands on Europa

NASA Technical Reports Server (NTRS)

Hurford, T. A.; Brunt, K. M.

2014-01-01

Europa's surface shows signs of extension, which is revealed as lithospheric dilation expressed along ridges, dilational bands and ridged bands. Ridges, the most common tectonic feature on Europa, comprise a central crack flanked by two raised banks a few hundred meters high on each side. Together these three classes may represent a continuum of formation. In Tufts' Dilational Model ridge formation is dominated by daily tidal cycling of a crack, which can be superimposed with regional secular dilation. The two sources of dilation can combine to form the various band morphologies observed. New GPS data along a rift on the Ross Ice Shelf, Antarctica is a suitable Earth analog to test the framework of Tufts' Dilational Model. As predicted by Tufts' Dilational Model, tensile failures in the Ross Ice Shelf exhibit secular dilation, upon which a tidal signal can be seen. From this analog we conclude that Tufts' Dilational Model for Europan ridges and bands may be credible and that the secular dilation is most likely from a regional source and not tidally driven.

The relation between sexual behavior and religiosity subtypes: a test of the secularization hypothesis.

PubMed

Farmer, Melissa A; Trapnell, Paul D; Meston, Cindy M

2009-10-01

Previous literature on religion and sexual behavior has focused on narrow definitions of religiosity, including religious affiliation, religious participation, or forms of religiousness (e.g., intrinsic religiosity). Trends toward more permissive premarital sexual activity in the North American Christian-Judeo religion support the secularization hypothesis of religion, which posits an increasing gap between religious doctrine and behavior. However, the recent rise of fundamentalist and new age religious movements calls for a reexamination of the current link between religion and sexual behavior. The use of dual definitions of religiosity, including religious affiliation and dimensional subtypes, may further characterize this link. The present cross-sectional study evaluated patterns of sexual behavior in a young adult sample (N = 1302, M age = 18.77 years) in the context of the secularization hypothesis using religious affiliation and a liberal-conservative continuum of religious subtypes: paranormal belief, spirituality, intrinsic religiosity, and fundamentalism. Results indicated few affiliation differences in sexual behavior in men or women. Sexual behaviors were statistically predicted by spirituality, fundamentalism, and paranormal belief, and the endorsement of fundamentalism in particular was correlated with lower levels of female sexual behavior. The secularization hypothesis was supported by consistent levels of sexual activity across affiliations and is contradicted by the differential impact of religiosity subtypes on sexual behavior. Findings suggested that the use of religious subtypes to evaluate religious differences, rather than solely affiliation, may yield useful insights into the link between religion and sexual behavior.

Post-Newtonian templates for binary black-hole inspirals: the effect of the horizon fluxes and the secular change in the black-hole masses and spins

NASA Astrophysics Data System (ADS)

Isoyama, Soichiro; Nakano, Hiroyuki

2018-01-01

Black holes (BHs) in an inspiraling compact binary system absorb the gravitational-wave (GW) energy and angular-momentum fluxes across their event horizons and this leads to the secular change in their masses and spins during the inspiral phase. The goal of this paper is to present ready-to-use, 3.5 post-Newtonian (PN) template families for spinning, non-precessing, binary BH inspirals in quasicircular orbits, including the 2.5 PN and 3.5 PN horizon-flux contributions as well as the correction due to the secular change in the BH masses and spins through 3.5 PN order, respectively, in phase. We show that, for binary BHs observable by Advanced LIGO with high mass ratios (larger than  ∼10) and large aligned-spins (larger than  ∼ 0.7 ), the mismatch between the frequency-domain template with and without the horizon-flux contribution is typically above the 3% mark. For (supermassive) binary BHs observed by LISA, even a moderate mass-ratios and spins can produce a similar level of the mismatch. Meanwhile, the mismatch due to the secular time variations of the BH masses and spins is well below the 1% mark in both cases, hence this is truly negligible. We also point out that neglecting the cubic-in-spin, point-particle phase term at 3.5 PN order would deteriorate the effect of BH absorption in the template.

Secular change of LOD caused by core evolution

NASA Astrophysics Data System (ADS)

Denis, C.; Rybicki, K. R.; Varga, P.

2003-04-01

Fossils and tidal deposits suggest that, on the average, the Earth's despinning rate had been five times less in the Proterozoic than in the Phanerozoic. This difference is probably due, for the major part, to the existence of a Proterozoic supercontinent. Nevertheless, core formation and core evolution should have compensated to some extent the effect of tidal friction, by diminishing the Earth's inertia moment. We have investigated quantitatively this contribution of the evolving core to the change of LOD. For the present epoch, we find that the solidification of the inner core causes a relative secular decrease of LOD of approximately 3 μs per century, whereas the macrodiffusion of iron oxides and sulfides from the D" into the outer core across the CMB (inasfar as Majewski's theory holds) leads to a relative secular decrease of LOD by about 15 μs per century. On the other hand, the theory of slow core formation developped by Runcorn in the early 1960s as a by-product of his theory of mantle-wide convection, leads to a relative secular decrease of LOD during most of the Proterozoic of about 0.25 ms per century. Although core formation is now widely assumed to have been a thermal run-away process that occurred shortly after the Earth itself had formed, Runcorn's theory of the growing core would nicely explain the observed palaeo-LOD curve. In any case, formation of the core implies, all in all, a relative decrease of LOD of typically 3 hours.

Pupil size in Jewish theological seminary students.

PubMed

Shemesh, G; Kesler, A; Lazar, M; Rothkoff, L

2004-01-01

To investigate the authors' clinical impression that pupil size among myopic Jewish theological seminary students is different from pupil size of similar secular subjects. This cross-sectional study was conducted on 28 male Jewish theological seminary students and 28 secular students or workers who were matched for age and refraction. All participants were consecutively enrolled. Scotopic and photopic pupil size was measured by means of a Colvard pupillometer. Comparisons of various parameters between the groups were performed using the two-sample t-test, Fisher exact test, a paired-sample t-test, a two-way analysis of variance, and Pearson correlation coefficients as appropriate. The two groups were statistically matched for age, refraction, and visual acuity. The seminary students were undercorrected by an average of 2.35 diopters (D), while the secular subjects were undercorrected by only 0.65 D (p<0.01). The average pupil size was larger in the religious group under both scotopic and photopic luminance. This difference was maintained when the two groups were compared according to iris color under both conditions, reaching a level of statistical significance (p<0.0001). There was a significant difference in photopic pupil size between dark and light irises (p=0.049), but this difference was not maintained under scotopic conditions. The average pupil size of young ultraorthodox seminary students was significantly larger than that of matched secular subjects. Whether this is the result of intensive close-up work or of apparently characteristic undercorrection of the myopia is undetermined.

On the univocity of rationality: a response to Nigel Biggar's 'Why religion deserves a place in secular medicine'.

PubMed

Symons, Xavier

2015-11-01

Nigel Biggar (2015) argues that religion deserves a place in secular medicine. Biggar suggests we abandon the standard rationalistic conception of the secular realm and see it rather as "a forum for the negotiation of rival reasonings". Religious reasoning is one among a number of ways of thinking that must vie for acceptance. Medical ethics, says Biggar, is characterised by "spiritual and moral mixture and ambiguity". We acknowledge this uncertainty by recognising rival viewpoints and agreeing to provisional compromises.In this response, I object to Biggar's characterisation of medical ethics as "morally ambiguous" and "provisional". I argue that Biggar has failed to provide adequate support for his conception of ethics as a "forum for negotiation and compromise". I criticise Biggar's attempt to 'pluralise' rationality, and assert that if religion is to play a role in secular medicine, it must be ready to defend itself against a universal standard of reason. In the second section of my response, I argue that 'theistic natural law' gives us the resources to defend using reason alone ostensibly faith-based positions in healthcare ethics. In doing so, we retain a univocal conception of rationality, while at the same time leaving space for 'theism' in healthcare ethics. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Religion and survival in a secular region. A twenty year follow-up of 734 Danish adults born in 1914.

PubMed

la Cour, Peter; Avlund, Kirsten; Schultz-Larsen, Kirsten

2006-01-01

The aim of the study was to analyse associations of religiosity and mortality in a secular region. The sample consisted of 734 Danish, community dwelling elderly persons, living in a secular culture, and all aged 70 when primary data were collected. Secondary data consisted of a 20 year follow-up on vital status or exact age of death. The study was designed to be highly comparable to studies conducted in more religious environments in order to compare results. Three variables of religion were investigated in relation to survival: importance of affiliation, church attendance and listening to religious media. Relative hazards (RH) of dying were controlled in models including gender, education, medical and mental health, social relations, help given and received, and health behaviour. The results showed significant and positive associations between claiming religious affiliation important and survival (relative hazard of dying=RH .70; 95% CI .58-.85) and church attendance and survival (RH .73; 95% CI .64-.87). Results decreased and only stayed significant regarding church attendance when controlled for covariates. Nearly all significant effects were seen in women, but not in men. The effect size of the full sample is less than in more religious environments in United States samples. Although the positive overall RHs are comparable to those of other studies, the mediating variables and pathways of effects seem dissimilar in this sample from a secular environment. Receiving and especially giving help to others are suggested as variables of explanatory value.

Annual, Seasonal, and Secular Changes in Time-Variable Gravity from GRACE

NASA Astrophysics Data System (ADS)

Lemoine, F. G.; Luthcke, S. B.; Klosko, S. M.; Rowlands, D. D.; Chinn, D. S.; McCarthy, J. J.; Ray, R. D.; Boy, J.

2007-12-01

The NASA/DLR GRACE mission, launched in 2002, has now operated for more than five years, producing monthly and ten-day snapshots of the variations of the gravity field of the Earth. The available solutions, either from spherical harmonics or from mascons, allow us new insights into the variations of surface gravity on the Earth at annual, inter-annual, and secular time scales. Our baseline time series, based on GGM02C, NCEP Atmospheric Gravity with IB, and GOT00 tides now is extended to July 2007, spanning four+ years, and we analyze both mascon and spherical harmonic solutions from this time series with respect to global hydrology variations. Our 4degx4deg mascon solutions are extended to cover all continental regions of the globe. Comparisons with hydrology (land-surface) models can offer insights into how these models might be improved. We compare our baseline time series, with new time series that include an updated Goddard Ocean Tide (GOT) model, ECMWF- 3hr atmosphere de-aliasing data, and the MOG-2D ocean dealiasing product. Finally, we intercompare the spherical harmonic solutions at low degree from GRACE from the various product centers (e.g., GFZ, CSR, GRGS), and look for secular signals in both the GSFC mascon and spherical harmonic solutions, taking care to compare the results for secular gravity field change with independent solutions developed over 25 years of independent tracking to geodetic satellites by Satellite Laser Ranging (SLR) and DORIS.

Geomagnetic Secular Variation Prediction with Thermal Heterogeneous Boundary Conditions

NASA Astrophysics Data System (ADS)

Kuang, W.; Tangborn, A.; Jiang, W.

2011-12-01

It has long been conjectured that thermal heterogeneity at the core-mantle boundary (CMB) affects the geodynamo substantially. The observed two pairs of steady and strong magnetic flux lobes near the Polar Regions and the low secular variation in the Pacific over the past 400 years (and perhaps longer) are likely the consequences of this CMB thermal heterogeneity. There are several studies on the impact of the thermal heterogeneity with numerical geodynamo simulations. However, direct correlation between the numerical results and the observations is found very difficult, except qualitative comparisons of certain features in the radial component of the magnetic field at the CMB. This makes it difficult to assess accurately the impact of thermal heterogeneity on the geodynamo and the geomagnetic secular variation. We revisit this problem with our MoSST_DAS system in which geomagnetic data are assimilated with our geodynamo model to predict geomagnetic secular variations. In this study, we implement a heterogeneous heat flux across the CMB that is chosen based on the seismic tomography of the lowermost mantle. The amplitude of the heat flux (relative to the mean heat flux across the CMB) varies in the simulation. With these assimilation studies, we will examine the influences of the heterogeneity on the forecast accuracies, e.g. the accuracies as functions of the heterogeneity amplitude. With these, we could be able to assess the model errors to the true core state, and thus the thermal heterogeneity in geodynamo modeling.

Physical fitness of children and adolescents in the United States: status and secular change.

PubMed

Malina, Robert M

2007-01-01

The physical fitness of school-age children in the United States is considered from two perspectives--status and secular change. This chapter principally examines health-related fitness, including the BMI, though performance-related fitness is briefly considered. Concepts of reference data and standards and factors that may influence secular change are initially discussed. National data on the physical fitness status of school children in the continental United States are limited to the 1980s. Ethnic variation in physical fitness is not considered except for the prevalence of overweight and obesity. More recent physical fitness data, including examination of ethnic variation, are based on several statewide and more local surveys. Although results vary by test, the majority of American school children meet or exceed criterion-referenced standards, although sex differences are not consistent. Poor morphological fitness manifest in obesity is an exception. The prevalence of overweight and obesity has increased since the early 1980s. Secular data for specific fitness items are less extensive. Regression analyses suggest a recent decline in maximal aerobic power in girls, but fairly stable levels between the 1930s and today in boys. However, the highest values for boys occur in the 1960s and 1970s and more recent values are somewhat lower. The general trend may be consistent with the decline since the 1980s in aerobic performance assessed with the 20 m shuttle run. These trends highlight the need for updated national physical fitness data for American youth.

The exotic remnants of compact object binary mergers

NASA Astrophysics Data System (ADS)

Duez, Matthew

2017-01-01

The collision and merger of a neutron star with a black hole or another neutron star is a strong source of gravitational waves and a promising setup for the creation of bright infrared (kilonova) and gamma ray (gamma ray burst) transients. These violent events can be modeled by numerical simulations incorporating general relativity, fluid dynamics, and nuclear physics. In this talk, I will explain the findings of some of these simulations. Depending on the properties of the binary, the merger leaves a black hole, a black hole accreting matter from a torus at an incredible rate, or a massive spinning neutron star. The latter two cases are characterized by the importance of differential rotation, magnetohydrodynamic processes, and neutrino radiation. To understand these systems, I will focus on what we know of their dynamical and thermal equilibrium structure, what we know of the dynamical instabilities to which they might be prone, and what we can tentatively say about their subsequent secular evolution from outflow, magnetic, radiative, and other effects. Computer simulations are becoming ever more impressive but remain unequal to the problem at hand, so I will address the challenges still posed by small-scale magnetohydrodynamic effects and by radiation transport. The author is a member of the SXS Collaboration and acknowledges support from NSF.

Response of gadolinium doped liquid scintillator to charged particles: measurement based on intrinsic U/Th contamination

NASA Astrophysics Data System (ADS)

Du, Q.; Lin, S. T.; He, H. T.; Liu, S. K.; Tang, C. J.; Wang, L.; Wong, H. T.; Xing, H. Y.; Yue, Q.; Zhu, J. J.

2018-04-01

A measurement is reported for the response to charged particles of a liquid scintillator named EJ-335 doped with 0.5% gadolinium by weight. This liquid scintillator was used as the detection medium in a neutron detector. The measurement is based on the in-situ α-particles from the intrinsic Uranium and Thorium contamination in the scintillator. The β–α and the α–α cascade decays from the U/Th decay chains were used to select α-particles. The contamination levels of U/Th were consequently measured to be (5.54±0.15)× 10‑11 g/g, (1.45±0.01)× 10‑10 g/g and (1.07±0.01)× 10‑11 g/g for 232Th, 238U and 235U, respectively, assuming secular equilibrium. The stopping power of α-particles in the liquid scintillator was simulated by the TRIM software. Then the Birks constant, kB, of the scintillator for α-particles was determined to be (7.28±0.23) mg/(cm2ṡMeV) by Birks' formulation. The response for protons is also presented assuming the kB constant is the same as for α-particles.

Understanding religious behavior.

PubMed

Levin, S

1979-01-01

The attached (to mother) fetus-infant finds his religious expression in Buddhism. The attached (to group) juvenile finds his religious expression in Judaism and other tribalisms. The attached (to spouse) adult finds his religious expression in agnosticism and secularism. Attached phases are placid and of progressively decreasing emotional intensity. The three detaching phases are hurtful and hence soteriological, and are also of progressively decreasing emotional intensity. The toddler-young child finds his religious expression in Christianity, the adolescent in atheism and/or Marxism, and the aged, sick or dying plucks at any religious or secular aid.

PUMPING THE ECCENTRICITY OF EXOPLANETS BY TIDAL EFFECT

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

Correia, Alexandre C. M.; Boue, Gwenaeel; Laskar, Jacques, E-mail: correia@ua.pt

2012-01-10

Planets close to their host stars are believed to undergo significant tidal interactions, leading to a progressive damping of the orbital eccentricity. Here we show that when the orbit of the planet is excited by an outer companion, tidal effects combined with gravitational interactions may give rise to a secular increasing drift on the eccentricity. As long as this secular drift counterbalances the damping effect, the eccentricity can increase to high values. This mechanism may explain why some of the moderate close-in exoplanets are observed with substantial eccentricity values.

Secular cooling of Earth as a source of intraplate stress

NASA Technical Reports Server (NTRS)

Solomon, Sean C.

1987-01-01

The once popular idea that changes in planetary volume play an important role in terrestrial orogeny and tectonics was generally discarded with the acceptance of plate tectonics. It is nonetheless likely that the Earth has been steadily cooling over the past 3-4 billion years, and the global contraction that accompanied such cooling would have led to a secular decrease in the radius of curvature of the plates. The implications of this global cooling and contraction are explored here for the intraplate stress field and the evolution of continental plates.

Secular Variation and Physical Characteristics Determination of the HADS Star EH Lib

NASA Astrophysics Data System (ADS)

Pena, J. H.; Villarreal, C.; Pina, D. S.; Renteria, A.; Soni, A., Guillen, J. Calderon, J.

2017-12-01

Physical parameters of EH Lib have been determined based on observations carried out in 2015 with photometry. They have also served, along with samples from the years 1969 and 1986, to analyse the frequency content of EH Lib with Fourier Transforms. Recent CCD observations increased the times of maximum with twelve new times which helped us study the secular variation of the period with a method based on the minimization of the standard deviation of the O-C residuals. It is concluded that there may be a long-term period change.

Modelling of chemical degradation of blended cement-based materials by leaching cycles with Callovo-Oxfordian porewater

NASA Astrophysics Data System (ADS)

Olmeda, Javier; Henocq, Pierre; Giffaut, Eric; Grivé, Mireia

2017-06-01

The present work describes a thermodynamic model based on pore water replacement cycles to simulate the chemical evolution of blended cement (BFS + FA) by interaction with external Callovo-Oxfordian (COx) pore water. In the framework of the radioactive waste management, the characterization of the radionuclide behaviour (solubility/speciation, adsorption) in cementitious materials needs to be done for several chemical degradation states (I to IV). In particular, in the context of the deep geological radioactive waste disposal project (Cigéo), cement-based materials will be chemically evolved with time in contact with the host-rock (COx formation). The objective of this study is to provide an equilibrium solution composition for each degradation state for a CEM-V cement-based material to support the adsorption and diffusion experiments reproducing any state of degradation. Calculations have been performed at 25 °C using the geochemical code PhreeqC and an up-to-date thermodynamic database (ThermoChimie v.9.0.b) coupled to SIT approach for ionic strength correction. The model replicates experimental data with accuracy. The approach followed in this study eases the analysis of the chemical evolution in both aqueous and solid phase to obtain a fast assessment of the geochemical effects associated to an external water intrusion of variable composition on concrete structures.

Kinetic Analysis of Phospholipase C from Catharanthus roseus Transformed Roots Using Different Assays1

PubMed Central

Hernández-Sotomayor, S.M. Teresa; De Los Santos-Briones, César; Muñoz-Sánchez, J. Armando; Loyola-Vargas, Victor M.

1999-01-01

The properties of phospholipase C (PLC) partially purified from Catharanthus roseus transformed roots were analyzed using substrate lipids dispersed in phospholipid vesicles, phospholipid-detergent mixed micelles, and phospholipid monolayers spread at an air-water interface. Using [33P]phosphatidylinositol 4,5-bisphosphate (PIP2) of high specific radioactivity, PLC activity was monitored directly by measuring the loss of radioactivity from monolayers as a result of the release of inositol phosphate and its subsequent dissolution on quenching in the subphase. PLC activity was markedly affected by the surface pressure of the monolayer, with reduced activity at extremes of initial pressure. The optimum surface pressure for PIP2 hydrolysis was 20 mN/m. Depletion of PLC from solution by incubation with sucrose-loaded PIP2 vesicles followed by ultracentrifugation demonstrated stable attachment of PLC to the vesicles. A mixed micellar system was established to assay PLC activity using deoxycholate. Kinetic analyses were performed to determine whether PLC activity was dependent on both bulk PIP2 and PIP2 surface concentrations in the micelles. The interfacial Michaelis constant was calculated to be 0.0518 mol fraction, and the equilibrium dissociation constant of PLC for the lipid was 45.5 μm. These findings will add to our understanding of the mechanisms of regulation of plant PLC. PMID:10444091

Development of a Fluorescence Assay for the Characterization of Brevenal Binding to Rat Brain Synaptosomes

PubMed Central

2015-01-01

The marine dinoflagellate Karenia brevis produces a family of neurotoxins known as brevetoxins. Brevetoxins elicit their effects by binding to and activating voltage-sensitive sodium channels (VSSCs) in cell membranes. K. brevis also produces brevenal, a brevetoxin antagonist, which is able to inhibit and/or negate many of the detrimental effects of brevetoxins. Brevenal binding to VSSCs has yet to be fully characterized, in part due to the difficulty and expense of current techniques. In this study, we have developed a novel fluorescence binding assay for the brevenal binding site. Several fluorescent compounds were conjugated to brevenal to assess their effects on brevenal binding. The assay was validated against the radioligand assay for the brevenal binding site and yielded comparable equilibrium inhibition constants. The fluorescence-based assay was shown to be quicker and far less expensive and did not generate radioactive waste or need facilities for handling radioactive materials. In-depth studies using the brevenal conjugates showed that, while brevenal conjugates do bind to a binding site in the VSSC protein complex, they are not displaced by known VSSC site specific ligands. As such, brevenal elicits its action through a novel mechanism and/or currently unknown receptor site on VSSCs. PMID:25226846

Removal of Cesium From Acidic Radioactive Tank Waste Using IONSIV IE-911 (CST)

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

Mann, Nicholas Robert; Todd, Terry Allen

2004-10-01

IONSIV IE-911, or the engineered form of crystalline silicotitanate (CST), manufactured by UOP Molecular Sieves, has been evaluated for the removal of cesium from Idaho National Engineering and Environmental Laboratory (INEEL) acidic radioactive tank waste. A series of batch contacts and column tests were performed by using three separate batches of CST. Batch contacts were performed to evaluate the concentration effects of nitric acid, sodium, and potassium ions on cesium sorption. Additional batch tests were performed to determine if americium, mercury, and plutonium would sorb onto IONSIV IE-911. An equilibrium isotherm was generated by using a concentrated tank waste simulant.more » Column tests using a 1.5 cm 3 column and flow rates of 3, 5, 10, 20, and 30 bed volumes (BV)/hr were performed to elucidate dynamic cesium sorption capacities and sorption kinetics. Additional experiments investigated the effect of CST batch and pretreatment on cesium sorption. The thermal stability of IONSIV IE-911 was evaluated by performing thermal gravimetric analysis/differential thermal analysis. Overall, IONSIV IE-911 was shown to be effective for cesium sorption from complex, highly acidic solutions; however, sorbent stability in these solutions may have a deleterious effect on cesium sorption.« less

Review of the Scientific Understanding of Radioactive Waste at the U.S. DOE Hanford Site

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

Peterson, Reid A.; Buck, Edgar C.; Chun, Jaehun

This paper reviews the origin and chemical and rheological complexity of radioactive waste at the U.S. Department of Energy’s Hanford Site. The waste, stored in underground tanks, was generated via three distinct processes over decades of plutonium extraction operations. Although close records were kept of original waste disposition, tank-to-tank transfers and conditions that impede equilibrium complicate our understanding of the chemistry, phase composition, and rheology of the waste. Tank waste slurries comprise particles and aggregates from nano to micron scales, with varying densities, morphologies, heterogeneous compositions, and complicated responses to flow regimes and process conditions. Further, remnant or changing radiationmore » fields may affect the stability and rheology of the waste. These conditions pose challenges for transport through conduits or pipes to treatment plants for vitrification. Additionally, recalcitrant boehmite degrades glass quality and must be reduced prior to vitrification, but dissolves much more slowly than predicted given surface normalized rates. Existing empirical models based on ex situ experiments and observations lack true predictive capabilities. Recent advances in in situ microscopy, aberration corrected TEM, theoretical modeling across scales, and experimental methods for probing the physics and chemistry at mineral-fluid and mineral-mineral interfaces are being implemented to build robustly predictive physics-based models.« less

Application of banana peels nanosorbent for the removal of radioactive minerals from real mine water.

PubMed

Oyewo, Opeyemi A; Onyango, Maurice S; Wolkersdorfer, Christian

2016-11-01

Transformation of agricultural waste such as banana peels into a valuable sorbent material has been proven effective and efficient in wastewater treatment. Further, transformation into nanosorbent to enhance the removal capacity of actinides (uranium and thorium) from synthetic and real mine water is extensively investigated in this study. The nanosorbent samples before and after adsorption were characterised by X-ray diffraction (XRD), Fourier transform infra-red (FTIR), zetasizer nanoseries and scanning electron microscopy (SEM) while the amount of radioactive substances adsorbed was determined by inductively coupled plasma optical emission spectroscopy. Results revealed that there was a crystallite size and particle size reduction from 108 to 12 nm and <65,000 nm to <25 nm respectively as a function of milling time. Furthermore, appearance and disappearance of nanofibers via milling was noticed during structural analysis. The functional groups responsible for the banana peels capability to coordinate and remove metal ions were identified at absorption bands of 1730 cm -1 (carboxylic groups) and 889 cm -1 (amine groups) via FTIR analysis. Equilibrium isotherm results demonstrated that the adsorption process was endothermic for both uranium and thorium. The Langmuir maximum adsorption capacity was 27.1 mg g -1 , 34.13 mg g -1 for uranium and 45.5 mg g -1 , 10.10 mg g -1 for thorium in synthetic and real mine water, respectively. The results obtained indicate that nanostructured banana peels is a potential adsorbent for the removal of radioactive substances from aqueous solution and also from real mine water. However, the choice of this sorbent material for any application depends on the composition of the effluent to be treated. Copyright © 2016 Elsevier Ltd. All rights reserved.

Effect of experimental variables onto Co(2+) and Sr(2+) sorption behavior in red mud-water suspensions.

PubMed

Milenković, Aleksandra S; Smičiklas, Ivana D; Šljivić-Ivanović, Marija Z; Živković, Ljiljana S; Vukelić, Nikola S

2016-07-02

The prospects of rinsed red mud (alumina production residue) utilization for liquid radioactive waste treatment have been investigated, with Co(2+) and Sr(2+) as model cations of radioactive elements. To evaluate the sorption effectiveness and corresponding binding mechanisms, the process was analyzed in batch conditions, by varying experimental conditions (pH, Co(2+) and Sr(2+) concentrations in single solutions and binary mixtures, contact time, and the concentration of competing cations and ligands common in liquid radioactive waste). Comparison of the Co(2+) and Sr(2+) sorption pH edges with the red mud isoelectric point has revealed that Co(2+) removal took place at both positive and negative red mud surface, while Sr(2+) sorption abruptly increased when the surface became negatively charged. The increase of initial cation content and pH resulted in increased equilibrium times and sorption capacity and decreased rate constants. From single metal solutions and various binary mixtures, Co(2+) was sorbed more efficiently and selectively than Sr(2+). While Sr(2+) sorption was reduced by coexisting cations in the order Al(3+) ≥ Ca(2+) >Na(+) ≥Cs(+), removal of Co(2+) was affected by Al(3+) species and complexing agents (EDTA and citrate). Desorption of Co(2+) was negligible in Ca(2+) and Sr(2+) containing media and in solutions with initial pH 4-7. Sr(2+) desorption was generally more pronounced, especially at low pH and in the presence of Co(2+). Collected macroscopic data signify that Co(2+) sorption by red mud minerals occurred via strong chemical bonds, while Sr(2+) was retained mainly by weaker ion-exchange or electrostatic interactions. Results indicate that the rinsed red mud represent an efficient, low-cost sorbent for Co(2+) and Sr(2+) immobilization.

A Centrifugal Contactor Design to Facilitate Remote Replacement

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

David H. Meikrantz; Jack. D. Law; Troy G. Garn

2011-03-01

Advanced designs of nuclear fuel recycling and radioactive waste treatment plants are expected to include more ambitious goals for solvent extraction based separations including; higher separations efficiency, high-level waste minimization, and a greater focus on continuous processes to minimize cost and footprint. Therefore, Annular Centrifugal Contactors (ACCs) are destined to play a more important role for such future processing schemes. This work continues the development of remote designs for ACCs that can process the large throughputs needed for future nuclear fuel recycling and radioactive waste treatment plants. A three stage, 12.5 cm diameter rotor module has been constructed and ismore » being evaluated for use in highly radioactive environments. This prototype assembly employs three standard CINC V-05 clean-in-place (CIP) units modified for remote service and replacement via new methods of connection for solution inlets, outlets, drain and CIP. Hydraulic testing and functional checks were successfully conducted and then the prototype was evaluated for remote handling and maintenance. Removal and replacement of the center position V-05R contactor in the three stage assembly was demonstrated using an overhead rail mounted PaR manipulator. Initial evaluation indicates a viable new design for interconnecting and cleaning individual stages while retaining the benefits of commercially reliable ACC equipment. Replacement of a single stage via remote manipulators and tools is estimated to take about 30 minutes, perhaps fast enough to support a contactor change without loss of process equilibrium. The design presented in this work is scalable to commercial ACC models from V-05 to V-20 with total throughput rates ranging from 20 to 650 liters per minute.« less

Secular decline of seawater calcium increases seawater buffering and pH

NASA Astrophysics Data System (ADS)

Hain, M.; Sigman, D. M.; Higgins, J. A.; Haug, G. H.

2015-12-01

Reconstructed changes in seawater calcium and magnesium concentration ([Ca2+], [Mg2+]) predictably affect the ocean's acid/base and carbon chemistry. Yet inaccurate formulations of chemical equilibrium "constants" are currently in use to account for these changes. Here we develop an efficient implementation of the MIAMI Ionic Interaction Model (Millero and Pierrot, 1998) to predict all chemical equilibrium constants required for carbon chemistry calculations under variable [Ca2+] and [Mg2+] (Hain et al., 2015). We investigate the impact of [Ca2+] and [Mg2+] on the relationships among the ocean's pH, CO2, dissolved inorganic carbon (DIC), saturation state of CaCO3 (Ω), and buffer capacity. Increasing [Ca2+] and/or [Mg2+] enhances "ion pairing," which increases seawater buffering by increasing the concentration ratio of total to "free" (uncomplexed) carbonate ion. An increase in [Ca2+], however, also causes a decline in carbonate ion to maintain a given Ω, thereby overwhelming the ion pairing effect and decreasing seawater buffering. Given the reconstructions of Eocene [Ca2+] and [Mg2+] ([Ca2+]~20mM; [Mg2+]~30 mM), Eocene seawater would have required essentially the same DIC as today to simultaneously explain a similar-to-modern Ω and the estimated Eocene atmospheric CO2 of ~1000 ppm. During the Cretaceous, at ~4 times modern [Ca2+], ocean buffering would have been at a minimum. Overall, during times of high seawater [Ca2+], CaCO3 saturation, pH, and atmospheric CO2 were more susceptible to perturbations of the global carbon cycle. For example, given both Eocene and Cretaceous seawater [Ca2+] and [Mg2+], a doubling of atmospheric CO2 would require less carbon addition to the ocean/atmosphere system than under modern seawater composition. Moreover, increase in seawater buffering since the Cretaceous may have been a driver of evolution by raising energetic demands of biologically controlled calcification and CO2 concentration mechanisms that aid photosynthesis.

A Nonequilibrium Figure of Saturn's Satellite Iapetus and the Origin of the Equatorial Ridge on Its Surface

NASA Astrophysics Data System (ADS)

Kondratyev, B. P.

2018-03-01

The structure, dynamical equilibrium, and evolution of Saturn's moon Iapetus are studied. It has been shown that, in the current epoch, the oblateness of the satellite ɛ2 ≈ 0.046 does not correspond to its angular velocity of rotation, which causes the secular spherization behavior of the ice shell of Iapetus. To study this evolution, we apply a spheroidal model, containing a rock core and an ice shell with an external surface ɛ2, to Iapetus. The model is based on the equilibrium finite-difference equation of the Clairaut theory, while the model parameters are taken from observations. The mean radius of the rock core and the oblateness of its level surface, ɛ1 ≈ 0.028, were determined. It was found that Iapetus is covered with a thick ice shell, which is 56.6% of the mean radius of the figure. We analyze a role of the core in the evolution of the shape of a gravitating figure. It was determined that the rock core plays a key part in the settling of the ice masses of the equatorial bulge, which finally results in the formation of a large circular equatorial ridge on the surface of the satellite. From the known mean altitude of this ice ridge, it was found that, in the epoch of its formation, the rotation period of Iapetus was 166 times shorter than that at present, as little as T ≈ 11h27m. This is consistent with the fact that a driving force of the evolution of the satellite in our model was its substantial despinning. The model also predicts that the ice ridge should be formed more intensively in the leading (dark and, consequently, warmer) hemisphere of the satellite, where the ice is softer. This inference agrees with the observations: in the leading hemisphere of Iapetus, the ridge is actually high and continuous everywhere, while it degenerates into individual ice peaks in the opposite colder hemisphere.

Geocenter Motion Derived from the JTRF2014 Combination

NASA Astrophysics Data System (ADS)

Abbondanza, C.; Chin, T. M.; Gross, R. S.; Heflin, M. B.; Parker, J. W.; van Dam, T. M.; Wu, X.

2016-12-01

JTRF2014 represents the JPL Terrestrial Reference Frame (TRF) recently obtained as a result of the combination of the space-geodetic reprocessed inputs to the ITRF2014. Based upon a Kalman filter and smoother approach, JTRF2014 assimilates station positions and Earth-Orientation Parameters (EOPs) from GNSS, VLBI, SLR and DORIS and combine them through local tie measurements. JTRF is in its essence a time-series based TRF. In the JTRF2014 the dynamical evolution of the station positions is formulated by introducing linear and seasonal terms (annual and semi-annual periodic modes). Non-secular and non-seasonal motions of the geodetic sites are included in the smoothed time series by properly defining the station position process noise whose variance is characterized by analyzing station displacements induced by temporal changes of planetary fluid masses (atmosphere, oceans and continental surface water). With its station position time series output at a weekly resolution, JTRF2014 materializes a sub-secular frame whose origin is at the quasi-instantaneous Center of Mass (CM) as sensed by SLR. Both SLR and VLBI contribute to the scale of the combined frame. The sub-secular nature of the frame allows the users to directly access the quasi-instantaneous geocenter and scale information. Unlike standard combined TRF products which only give access to the secular component of the CM-CN motions, JTRF2014 is able to preserve -in addition to the long-term- the seasonal, non-seasonal and non-secular components of the geocenter motion. In the JTRF2014 assimilation scheme, local tie measurements are used to transfer the geocenter information from SLR to the space-geodetic techniques which are either insensitive to CM (VLBI) or whose geocenter motion is poorly determined (GNSS and DORIS). Properly tied to the CM frame through local ties and co-motion constraints, GNSS, VLBI and DORIS contribute to improve the SLR network geometry. In this paper, the determination of the weekly (CM-CN) time series as inferred from the JTRF2014 combination will be presented. Comparisons with geocenter time series derived from global inversions of GPS, GRACE and ocean bottom pressure models show the JTRF2014-derived geocenter favourably compares to the results of the inversion.

Secular Change and Inter-annual Variability of the Gulf Stream Position, 1993-2013, 70°-55°W

NASA Astrophysics Data System (ADS)

Bisagni, J. J.; Gangopadhyay, A.

2016-12-01

The Gulf Stream (GS) is the northeastward-flowing surface limb of the Atlantic Ocean meridional overturning circulation (AMOC) "conveyer belt" that flows towards Europe and the Nordic Seas. Changes in the GS position after its separation from the coast at Cape Hatteras, i.e., from 75°W to 50°W, may be key to understanding the AMOC, sea level variability and ecosystem behavior along the east coast of North America. In this study we compare secular change and inter-annual variability (IAV) of annual mean Gulf Stream North Wall (GSNW) position with equator-ward Labrador Current (LC) transport along the southwestern Grand Banks near 52° W using 21 years (1993-2013) of satellite altimeter data. Results at 70°, 65°, 60° and 55° W show a southward secular trend for the GSNW, decreasing to the west. IAV of de-trended GSNW position residuals also decreases to the west. The long-term secular trend of annual mean upper layer LC transport increases near 52° W. Furthermore, IAV of LC transport residuals near 52° W is significantly correlated with GSNW position residuals at 55° W at a lag of +1-year. Spectral analysis reveals inter-annual peaks at 5-7 years and 2-3 years for the North Atlantic Oscillation (NAO), GSNW (65°-55°W) and LC transport for 1993-2013. A volume calculation using the LC rms residual of +1.04 Sv near 52° W results in an estimated GSNW residual of 79 km, or 63% of the observed 125.6 km (1.13°) rms value at 55° W. A similar volume calculation using the positive long-term, upper-layer LC transport trend accounts for 68% of the observed southward shift of the GSNW over the 1993-2013 period. Our work provides observational evidence of direct interaction between the upper layers of the sub-polar and sub-tropical gyres within the North Atlantic over secular and inter-annual time scales as suggested by previous workers.

The Remarkable Change in Euro-American Cranial Shape and Size.

PubMed

Jantz, Richard L; Jantz, Lee Meadows

2016-01-01

Secular changes in stature, weight, or other components of the body that can be obtained from historical records have been extensively studied. Cranial change has been central to anthropology for more than a century, but the focus has normally been on change measured in centuries or millennia. Cranial change measured in decades, normally considered to result from plastic response to the environment, has been less studied. This article reports on change in cranial vault dimensions in white Americans. Variables were glabello-occipital length (GOL), basion-bregma height (BBH), basion-nasion length (BNL), maximum cranial breadth (XCB), and biauricular breadth (AUB). Cranial size was calculated as the geometric mean of these variables, and shape dimensions were calculated as described by Darroch and Mosimann ( 1985 ). Cranial module and cranial capacity were also calculated. Samples consisted of 1,112 males and 668 females complete for those variables. Samples were organized into 10-year birth cohorts, with birth years ranging from 1820 to 1990. One-way ANOVA was used to test for variation among cohorts. The pattern of secular change was examined graphically and was compared with quality-of-life and environmental indicators, including stature, infant mortality, calories per person, and relative number of immigrants. All variables showed significant secular change, but BBH, XCB, and BNL responded most strongly. Over the past 170 years, crania became relatively higher, narrower, and larger with longer cranial bases. Both sexes changed, but female change was less pronounced than male change. The cranial variables tracked secular changes in stature, most prominently BNL. The highest correlation between a cranial variable and quality-of-life indicator was BBH and infant mortality. We are not able to identify specific causes of secular changes in cranial morphology. However, given that modern Americans have introduced themselves into a novel environment never before experienced by human populations, we consider it unlikely that it is pure plasticity. In addition to possible plastic responses, it is likely that selection, acting through the dramatic changes in infant mortality, is also involved.

Secular trends of salted fish consumption and nasopharyngeal carcinoma: a multi-jurisdiction ecological study in 8 regions from 3 continents

PubMed Central

2013-01-01

Background Despite salted fish being a classical risk factor of Nasopharyngeal Carcinoma (NPC), whether secular trends in salted fish consumption worldwide accounted for changes in NPC rates were unknown. The relationship between vegetable and cigarette consumption to NPC risk worldwide were also largely uncertain. We investigated the longitudinal trends in standardised NPC incidence/mortality rates across 8 regions and their associations with secular trends in salted fish, vegetable and tobacco consumptions. Methods Age standardised mortality rate (ASMR) and age standardised incidence rate (ASIR) of NPC were obtained from the WHO cancer mortality database and Hong Kong Cancer Registry. Per capita consumption of salted fish, tobacco and vegetables in Hong Kong and 7 countries (China, Finland, Japan, Portugal, Singapore, United Kingdom and United States) were obtained from the Food and Agriculture Organization of the United Nation (FAO) and Hong Kong Trade and Census Statistics. Pearson correlation and multivariate analysis were performed to examine both crude and adjusted associations. Results There were markedly decreasing trends of NPC ASIR and ASMR in Hong Kong over the past three decades, which were correlated with corresponding secular changes in salted fish consumption per capita (Pearson r for 10 cumulative years : ASIR = 0.729 (male), 0.674 (female); ASMR = 0.943 (male), 0.622 (female), all p < 0.05 except for female ASMR). However such associations no longer correlated with adjustments for decreasing tobacco and increasing vegetable consumption per capita (Pearson r for 10 cumulative years: ASIR = 2.007 (male), 0.339 (female), ASMR = 0.289 (male), 1.992 (female), all p > 0.05). However, there were no clear or consistent patterns in relations between NPC ASIR and ASMR with salted fish consumption across 7 regions in 3 continents. Conclusions Our results do not support the notion that changes in salted fish consumption had played an important role in explaining secular trends of NPC rates in Hong Kong and worldwide. Further studies should explore other lifestyle and genetic factors. However, our findings do support the potentially protective effects of vegetable consumption against NPC. PMID:23782497

Secular trends of salted fish consumption and nasopharyngeal carcinoma: a multi-jurisdiction ecological study in 8 regions from 3 continents.

PubMed

Lau, Hiu-Ying; Leung, Chit-Ming; Chan, Yap-Hang; Lee, Anne Wing-Mui; Kwong, Dora Lai-Wan; Lung, Maria Li; Lam, Tai-Hing

2013-06-19

Despite salted fish being a classical risk factor of Nasopharyngeal Carcinoma (NPC), whether secular trends in salted fish consumption worldwide accounted for changes in NPC rates were unknown. The relationship between vegetable and cigarette consumption to NPC risk worldwide were also largely uncertain. We investigated the longitudinal trends in standardised NPC incidence/mortality rates across 8 regions and their associations with secular trends in salted fish, vegetable and tobacco consumptions. Age standardised mortality rate (ASMR) and age standardised incidence rate (ASIR) of NPC were obtained from the WHO cancer mortality database and Hong Kong Cancer Registry. Per capita consumption of salted fish, tobacco and vegetables in Hong Kong and 7 countries (China, Finland, Japan, Portugal, Singapore, United Kingdom and United States) were obtained from the Food and Agriculture Organization of the United Nation (FAO) and Hong Kong Trade and Census Statistics. Pearson correlation and multivariate analysis were performed to examine both crude and adjusted associations. There were markedly decreasing trends of NPC ASIR and ASMR in Hong Kong over the past three decades, which were correlated with corresponding secular changes in salted fish consumption per capita (Pearson r for 10 cumulative years : ASIR = 0.729 (male), 0.674 (female); ASMR = 0.943 (male), 0.622 (female), all p < 0.05 except for female ASMR). However such associations no longer correlated with adjustments for decreasing tobacco and increasing vegetable consumption per capita (Pearson r for 10 cumulative years: ASIR = 2.007 (male), 0.339 (female), ASMR = 0.289 (male), 1.992 (female), all p > 0.05). However, there were no clear or consistent patterns in relations between NPC ASIR and ASMR with salted fish consumption across 7 regions in 3 continents. Our results do not support the notion that changes in salted fish consumption had played an important role in explaining secular trends of NPC rates in Hong Kong and worldwide. Further studies should explore other lifestyle and genetic factors. However, our findings do support the potentially protective effects of vegetable consumption against NPC.

A reactive distillation process for the treatment of LiCl-KCl eutectic waste salt containing rare earth chlorides

NASA Astrophysics Data System (ADS)

Eun, H. C.; Choi, J. H.; Kim, N. Y.; Lee, T. K.; Han, S. Y.; Lee, K. R.; Park, H. S.; Ahn, D. H.

2016-11-01

The pyrochemical process, which recovers useful resources (U/TRU metals) from used nuclear fuel using an electrochemical method, generates LiCl-KCl eutectic waste salt containing radioactive rare earth chlorides (RECl3). It is necessary to develop a simple process for the treatment of LiCl-KCl eutectic waste salt in a hot-cell facility. For this reason, a reactive distillation process using a chemical agent was achieved as a method to separate rare earths from the LiCl-KCl waste salt. Before conducting the reactive distillation, thermodynamic equilibrium behaviors of the reactions between rare earth (Nd, La, Ce, Pr) chlorides and the chemical agent (K2CO3) were predicted using software. The addition of the chemical agent was determined to separate the rare earth chlorides into an oxide form using these equilibrium results. In the reactive distillation test, the rare earth chlorides in LiCl-KCl eutectic salt were decontaminated at a decontamination factor (DF) of more than 5000, and were mainly converted into oxide (Nd2O3, CeO2, La2O3, Pr2O3) or oxychloride (LaOCl, PrOCl) forms. The LiCl-KCl was purified into a form with a very low concentration (<1 ppm) for the rare earth chlorides.

Supercoiled circular DNA of an insect granulosis virus

PubMed Central

Tweeten, Kathleen A.; Bulla, Lee A.; Consigli, Richard A.

1977-01-01

The DNA of the granulosis virus of the Indian meal moth, Plodia interpunctella, was characterized by physical chemical and electron microscopic techniques. Twenty-five percent of the DNA extracted from purified virus was isolated as supercoiled circular molecules. The remaining 75% consisted of relaxed circular molecules. These molecular forms were indicated by the production of two radioactive bands during sedimentation of 3H-labeled granulosis virus DNA in alkaline sucrose gradients or in equilibrium density gradients of neutral cesium chloride/propidium iodide. Electron microscopic visualization of the DNA that banded at the higher density in the latter gradients revealed supercoiled structures whereas that of DNA that banded at the lower density demonstrated relaxed circular molecules. The superhelical molecules were converted to relaxed circles by treatment with pancreatic DNase. The molecular weight of the viral DNA was calculated to be 81 × 106 by sedimentation in neutral sucrose and 78 × 106 by sedimentation in alkaline sucrose. The molecular weight estimated from length measurements in electron micrographs was 76 × 106. The buoyant density of the granulosis virus DNA was 1.703 g/cm3 and that of its insect host DNA was 1.697 g/cm3. Equilibrium sedimentation in cesium chloride and thermal denaturation indicated G + C contents of 44% and 39% for the viral and host DNA, respectively. Images PMID:198791

Supercoiled circular DNA of an insect granulosis virus.

PubMed

Tweeten, K A; Bulla, L A; Consigli, R A

1977-08-01

The DNA of the granulosis virus of the Indian meal moth, Plodia interpunctella, was characterized by physical chemical and electron microscopic techniques. Twenty-five percent of the DNA extracted from purified virus was isolated as supercoiled circular molecules. The remaining 75% consisted of relaxed circular molecules. These molecular forms were indicated by the production of two radioactive bands during sedimentation of (3)H-labeled granulosis virus DNA in alkaline sucrose gradients or in equilibrium density gradients of neutral cesium chloride/propidium iodide. Electron microscopic visualization of the DNA that banded at the higher density in the latter gradients revealed supercoiled structures whereas that of DNA that banded at the lower density demonstrated relaxed circular molecules. The superhelical molecules were converted to relaxed circles by treatment with pancreatic DNase. The molecular weight of the viral DNA was calculated to be 81 x 10(6) by sedimentation in neutral sucrose and 78 x 10(6) by sedimentation in alkaline sucrose. The molecular weight estimated from length measurements in electron micrographs was 76 x 10(6). The buoyant density of the granulosis virus DNA was 1.703 g/cm(3) and that of its insect host DNA was 1.697 g/cm(3). Equilibrium sedimentation in cesium chloride and thermal denaturation indicated G + C contents of 44% and 39% for the viral and host DNA, respectively.

Why did children grow so well at hard times? The ultimate importance of pathogen control during puberty

PubMed Central

Hõrak, Peeter; Valge, Markus

2015-01-01

Background and objectives: Secular increase in human height and performance occurred in Europe throughout the 20th century despite the temporally worsening access to nutrients during and after World War II. This pattern is paradoxical under the assumption of the major impact of pre- and postnatal growth conditions for determination of adult size and human capital. Methodology: We examined the anthropometric parameters of Estonian girls born between 1938 and 1953, and measured around the age of 17 (n = 1475). This period involved two opposite trends in the economic and epidemiological situation: increasing birth-time economic hardships during the war and particularly in the post-war period, and decreasing infant mortality (a proxy of disease burden) after 1947. Results: Height of girls was negatively affected by the number of siblings and positively by parental socioeconomic position, but these effects were weaker than the secular trend. Leg length (an indicator of pre-pubertal growth conditions) was independent of age and birth date while all other traits, including measures of performance (cranial volume, lung capacity and handgrip strength) showed acceleration. The best predictor of size at age 17 was, in most cases, infant mortality in the year when the girls were aged 11. Conclusions and implications: Reduction of disease burden during pubertal growth can override effects of resource shortage at birth. Our results also support the idea that increasing efficiency of pathogen control can contribute to the secular increase in cognitive abilities, i.e. the Flynn effect, and that epidemiological transition is the main driver of secular increase in human capital. PMID:26198188

A Comparison of Paleomagnetic Secular Variation during MIS 7-10 between the Bering Sea (IODP Ex. 323) and North Atlantic Ocean (ODP Leg 172): Implications for the space/time pattern of field and environmental variability (Invited)

NASA Astrophysics Data System (ADS)

Lund, S.; Okada, M.; Acton, G.; Clement, B. M.; Stoner, J. S.; Platzman, E. S.

2013-12-01

Detailed records of Brunhes paleomagnetic secular variation (PSV) during Marine Isotope Stages (MIS) 7-10 have been recovered from four IODP Ex. 323 sites in the Bering Sea (U1339, U1343-U1345) and four ODP Leg 172 sites from the subtropical North Atlantic Ocean (1060-1063). Reproducible records of PSV (both directions and paleointensity) have been recovered from three or more holes at each site and correlated among the four independent sites in each region. These PSV records provide an unprecedented database for considering patterns of long-term secular variation and evidence for excursional field behavior on a larger than individual regional scale. We will present reproducible evidence for sustained long-term secular variation in each region and assess the extent to which they may be interrelated. We have identified the times of magnetic field excursions 7α, 7β, 8α, 9α, and 9β in the Atlantic records and correlated those times to the Bering Sea records. There are no true excursions in the Bering Sea at those times, but several of these intervals mark the most anomalous field behavior in the Bering Sea during MIS 7-10. In both regions, the PSV also serves as a high-resolution chronostratigraphic tool for regional correlation of environmental variability. Both regions show clear, reproducible evidence among the sites for synchronous millennial-scale environmental variability that has not been diagnosed previously.

Main field and secular variation candidate models for the 12th IGRF generation after 10 months of Swarm measurements

NASA Astrophysics Data System (ADS)

Saturnino, Diana; Langlais, Benoit; Civet, François; Thébault, Erwan; Mandea, Mioara

2015-06-01

We describe the main field and secular variation candidate models for the 12th generation of the International Geomagnetic Reference Field model. These two models are derived from the same parent model, in which the main field is extrapolated to epoch 2015.0 using its associated secular variation. The parent model is exclusively based on measurements acquired by the European Space Agency Swarm mission between its launch on 11/22/2013 and 09/18/2014. It is computed up to spherical harmonic degree and order 25 for the main field, 13 for the secular variation, and 2 for the external field. A selection on local time rather than on true illumination of the spacecraft was chosen in order to keep more measurements. Data selection based on geomagnetic indices was used to minimize the external field contributions. Measurements were screened and outliers were carefully removed. The model uses magnetic field intensity measurements at all latitudes and magnetic field vector measurements equatorward of 50° absolute quasi-dipole magnetic latitude. A second model using only the vertical component of the measured magnetic field and the total intensity was computed. This companion model offers a slightly better fit to the measurements. These two models are compared and discussed.We discuss in particular the quality of the model which does not use the full vector measurements and underline that this approach may be used when only partial directional information is known. The candidate models and their associated companion models are retrospectively compared to the adopted IGRF which allows us to criticize our own choices.

Diffusive Tidal Evolution for Migrating Hot Jupiters

NASA Astrophysics Data System (ADS)

Wu, Yanqin

2018-03-01

I consider a Jovian planet on a highly eccentric orbit around its host star, a situation produced by secular interactions with its planetary or stellar companions. The tidal interactions at every periastron passage exchange energy between the orbit and the planet’s degree-2 fundamental-mode. Starting from zero energy, the f-mode can diffusively grow to large amplitudes if its one-kick energy gain is ≥10‑5 of the orbital energy. This requires a pericenter distance of ≤4 tidal radii (or 1.6 Roche radii). If the f-mode has a non-negligible initial energy, diffusive evolution can occur at a lower threshold. The first effect can stall the secular migration as the f-mode can absorb orbital energy and decouple the planet from its secular perturbers, parking all migrating jupiters safely outside the zone of tidal disruption. The second effect leads to rapid orbit circularization as it allows an excited f-mode to continuously absorb orbital energy as the orbit eccentricity decreases. So without any explicit dissipation, other than the fact that the f-mode will damp nonlinearly when its amplitude reaches unity, the planet can be transported from a few au to ∼0.2 au in ∼104 years. Such a rapid circularization is equivalent to a dissipation factor Q ∼ 1, and it explains the observed deficit of super-eccentric Jovian planets. Lastly, the repeated f-mode breaking likely deposits energy and angular momentum in the outer envelope and avoids thermally ablating the planet. Overall, this work boosts the case for hot Jupiter formation through high-eccentricity secular migration.

Secular Trends in the Incidence of Dementia in a Multi-Ethnic Community.

PubMed

Noble, James M; Schupf, Nicole; Manly, Jennifer J; Andrews, Howard; Tang, Ming-Xin; Mayeux, Richard

2017-10-03

Determination of secular trends in cognitive aging is important for prioritization of resources, services, and research in aging populations. Prior studies have identified declining dementia incidence associated with changes in cardiovascular risk factors and increased educational attainment. However, few studies have examined these factors in multi-ethnic cohorts. To identify secular trends in the incidence rate of dementia in an elderly population. Participants in this study were drawn from the Washington Heights-Inwood Columbia Aging Project, a multi-ethnic cohort study of northern Manhattan residents aged 65 years and older. Cox proportional hazards models were used to examine differences in the incidence of dementia in cohorts recruited in 1992 and 1999, with age at dementia or age at last follow-up visit as the "time-to-event" variable. Overall, there was a 41% reduction in the hazard ratio for dementia among participants in the 1999 cohort compared with those in the 1992 cohort, adjusting for age, sex, race, and baseline memory complaints (HR = 0.59). The reduction in incidence was greatest among non-Hispanic Whites and African-Americans and lowest among Hispanic participants (HRs = 0.60, 0.52 and 0.64, respectively), and was associated with increases in level of educational attainment, especially among African-Americans. Reduction in incidence of dementia was also greater among persons 75 years or older than among younger participants (HR = 0.52 versus HR = 0.69). Our results support previous findings that secular trends in dementia incidence are changing, including in aging minority populations.

On the highly inclined vW leptokurtic asteroid families

NASA Astrophysics Data System (ADS)

Carruba, V.; Domingos, R. C.; Aljbaae, S.; Huaman, M.

2016-11-01

vW leptokurtic asteroid families are families for which the distribution of the normal component of the terminal ejection velocity field vW is characterized by a positive value of the γ2 Pearson kurtosis, I.e. they have a distribution with a more concentrated peak and larger tails than the Gaussian one. Currently, eight families are known to have γ2(vW) > 0.25. Among these, three are highly inclined asteroid families, the Hansa, Barcelona, and Gallia families. As observed for the case of the Astrid family, the leptokurtic inclination distribution seems to be caused by the interaction of these families with node secular resonances. In particular, the Hansa and Gallia family are crossed by the s - sV resonance with Vesta, that significantly alters the inclination of some of their members. In this work we use the time evolution of γ2(vW) for simulated families under the gravitational influence of all planets and the three most massive bodies in the main belt to assess the dynamical importance (or lack of) node secular resonances with Ceres, Vesta, and Pallas for the considered families, and to obtain independent constraints on the family ages. While secular resonances with massive bodies in the main belt do not significantly affect the dynamical evolution of the Barcelona family, they significantly increase the γ2(vW) values of the simulated Hansa and Gallia families. Current values of the γ2(vW) for the Gallia family are reached over the estimated family age only if secular resonances with Vesta are accounted for.

The new genetic technologies: why a theological perspective is necessary.

PubMed

Engelhardt, H Tristram

2003-01-01

Secular bioethics poses questions that can be recognized as important, though it lacks the resources to answer them. Secular bioethics may retain the sense that there should be moral limits to the use of germline genetic engineering, but it lacks the basis to justify limits in principle. The contemporary practice of bioethics arose in the United States to fill a moral vacuum created by (1) the marginalization of medical ethics through the deprofessionalization of medicine, (2) the secularization of American society, and (3) an increased reliance on individual decision-making. The result is an ethics at the core of secular bioethics severed from a sense of ultimate purpose or direction for humans or the cosmos. This ethics and its bioethics are marked by (1) moral fragmentation and pluralism and (2) a loss of ultimate orientation. This bioethics can at best require (1) the prudent maximization of benefits over harms, (2) the condemnation of malevolent acts, and (3) the use of persons only with their consent. However, there fails to be a basis for a common view of benefit or of harm. Within this impoverished moral context, human biological nature can only appear to be a contingent outcome of spontaneous mutations, selective pressure, the constraints of physical laws, and random catastrophes. Such a bioethics, deprived of ultimate orientation, can provide no ground in principle for forbidding cloning, germline genetic engineering, or the fundamental recasting of human nature. Absent a theological point of orientation, medicine and the genetic technology are left with more power than ever but no clear moral sense of how to use that power.

Secular change in muscular strength of indigenous rural youth 6-17 years in Oaxaca, southern Mexico: 1968-2000.

PubMed

Malina, Robert M; Reyes, Maria Eugenia Peña; Tan, Swee Kheng; Little, Bertis B

2010-04-01

The study compared the grip strength of indigenous school youth 6-17 years of age in Oaxaca, southern Mexico, who were surveyed in 1968, 1978 and 2000. Grip strength (Smedley/Stoelting) was measured to 0.5 kg in 1280 children and adolescent, 621 males and 659 females, in the three surveys. Height and weight were also measured. Strength of the right and left hands was summed to provide a general estimate of muscular strength. Summed grip strength was also expressed per unit body mass (kg/kg) and height (kg/m). Subjects were classified into four age groups: 6-8 years (childhood), 9-11 years (transition in adolescence), 12-14 years (early adolescence) and 15-17 years (later adolescence). Children 6-14 years were surveyed in 1968, 1978 and 2000 while adolescents 15-17 years were surveyed in 1978 and 2000. Sex-specific MANCOVAs were used for comparisons among years within age groups. Changes in grip strength between 1968 and 1978 among children 6-14 years were small and significant only in girls. Grip strength increased, on average, between 1978 and 2000 in boys 6-17 years but only in girls 6-14 years; adolescent girls 15-17 years in 1978 were stronger than those in 2000. Secular gains in muscular strength were generally proportional to secular gains in body weight and height. The data demonstrate secular changes in muscular strength in indigenous rural youth in a community in the process of transition from subsistence level agriculture to an economy less dependent upon agriculture.

Secular versus religious norms against smoking: Which is more important as a driver of quitting behaviour among Muslim Malaysian and Buddhist Thai smokers?

PubMed Central

Yong, Hua-Hie; Savvas, Steven; Borland, Ron; Thrasher, James; Sirirassamee, Buppha; Omar, Maizurah

2012-01-01

Purpose This paper prospectively examined two kinds of social normative beliefs about smoking, secular versus religious norms, to determine their relative importance in influencing quitting behaviour among Muslim Malaysian and Buddhist Thai smokers. Methods Data come from 2166 Muslim Malaysian and 2463 Buddhist Thai adult smokers who participated in the first three waves of the International Tobacco Control Southeast Asia project. Respondents were followed up about 18 months later with replenishment. Respondents were asked at baseline about whether their society disapproved of smoking and whether their religion discouraged smoking and those recontacted at follow-up were asked about their quitting activity. Results Majority of both religious groups perceived that their religion discouraged smoking (78% Muslim Malaysians and 86% Buddhist Thais) but considerably more Buddhist Thais than Muslim Malaysians perceived that their society disapproved of smoking (80% versus 25%). Among Muslim Malaysians, religious, but not societal, norms had an independent effect on quit attempts. By contrast, among the Buddhist Thais, while both normative beliefs had an independent positive effect on quit attempts, the effect was greater for societal norms. The two kinds of normative beliefs, however, were unrelated to quit success among those who tried. Conclusions The findings suggest that religious norms about smoking may play a greater role than secular norms in driving behaviour change in an environment like Malaysia where tobacco control has been relatively weak until more recently but in the context of a strong tobacco control environment like Thailand, secular norms about smoking becomes the dominant force. PMID:22302214

On the Existence of Regular and Irregular Outer Moons Orbiting the Pluto-Charon System

NASA Astrophysics Data System (ADS)

Michaely, Erez; Perets, Hagai B.; Grishin, Evgeni

2017-02-01

The dwarf planet Pluto is known to host an extended system of five co-planar satellites. Previous studies have explored the formation and evolution of the system in isolation, neglecting perturbative effects by the Sun. Here we show that secular evolution due to the Sun can strongly affect the evolution of outer satellites and rings in the system, if such exist. Although precession due to extended gravitational potential from the inner Pluto-Charon binary quench such secular evolution up to a crit ˜ 0.0035 au (˜0.09 R Hill the Hill radius; including all of the currently known satellites), outer orbits can be significantly altered. In particular, we find that co-planar rings and satellites should not exist beyond a crit; rather, satellites and dust particles in these regions secularly evolve on timescales ranging between 104 and 106 years, and quasi-periodically change their inclinations and eccentricities through secular evolution (Lidov-Kozai oscillations). Such oscillations can lead to high inclinations and eccentricities, constraining the range where such satellites (and dust particles) can exist without crossing the orbits of the inner satellites or crossing the outer Hill stability range. Outer satellites, if such exist are therefore likely to be irregular satellites, with orbits limited to be non-circular and/or highly inclined. Current observations, including the recent data from the New-Horizons mission explored only inner regions (<0.0012 au) and excluded the existence of additional satellites; however, the irregular satellites discussed here should reside farther, in the yet uncharted regions around Pluto.

Timing and secular trend of pubertal development in Beijing girls.

PubMed

Chen, Fang-Fang; Wang, You-Fa; Mi, Jie

2014-02-01

Historical research is limited in changes in pubertal development in Chinese girls. We aimed to identify the timing of pubertal characteristics and the secular trend of menarche age among Beijing girls from the 1980s through the 2000s. Six data sets were analyzed, including the Beijing Child and Adolescent Metabolic Syndrome study in 2004, where 9778 Bejing girls aged 6-18 years were studied. The Fetal Origins of Adult Disease study provided retrospective menarche age from 1940 through 1960. Other four studies were conducted in Beijing to obtain supplementary information to assess secular trend in menarche age. Linear regression method was used to analyze the data. Among Beijing girls in 2004, the median age at menarche was 12.1 years, which was 0.6 years earlier in urban than in rural areas. The median age at Breast Tanner Stage 2 was 9.5 ± 1.2 years, representing 9.4 ± 1.1 years and 9.6 ± 1.2 years for urban and rural girls, respectively. In contrast, the median age at Pubic Hair Tanner Stage 2 was 11.1 ± 1.1 years, representing 10.8 ± 1.1 and 11.4 ± 1.1 years for urban and rural girls, respectively. The menarche age of urban girls decreased by 4.2 months per decade, and that of rural girls by 9.6 months per decade from 1980 to 2004. Urban girls mature earlier than rural girls in Beijing. A secular trend towards earlier menarche was observed between the 1980s and the 2000s.

Sorption--desorption studies on granite. I. Initial studies of strontium, technetium, cesium, barium, cerium, europium, uranium, plutonium, and americium

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

Erdal, B.R.; Aguilar, R.D.; Bayhurst, B.P.

Distribution ratios were determined for sorption--desorption of radioactive tracers between the Climax Stock granite (quartz monzonite porphyry) obtained at Nevada Test Site and a water prepared to be resonably representative of the natural composition of water in equilibrium with the Climax Stock granite. The measurements were performed at 22 and 70{sup 0}C under atmospheric oxygen conditions. Elements given in order of increasing distribution coefficient at ambient temperature are: U(VI), Sr, Tc(VII), Ba, Ce(III), Cs, Eu(III), Pu, and Am. At 70{sup 0}C the order is: Tc(VII), Sr, Ce(III), Eu(III), Ba, Cs, Pu, and Am. The effects of surface area and mineralogymore » on sorption were also investigated.« less

Secular trends in Cherokee cranial morphology: Eastern vs Western bands.

PubMed

Sutphin, Rebecca; Ross, Ann H; Jantz, Richard L

2014-01-01

The research objective was to examine if secular trends can be identified for cranial data commissioned by Boas in 1892, specifically for cranial breadth and cranial length of the Eastern and Western band Cherokee who experienced environmental hardships. Multiple regression analysis was used to test the degree of relationship between each of the cranial measures: cranial length, cranial breadth and cephalic index, along with predictor variables (year-of-birth, location, sex, admixture); the model revealed a significant difference for all craniometric variables. Additional regression analysis was performed with smoothing Loess plots to observe cranial length and cranial breadth change over time (year-of-birth) separately for Eastern and Western Cherokee band females and males born between 1783-1874. This revealed the Western and Eastern bands show a decrease in cranial length over time. Eastern band individuals maintain a relatively constant head breadth, while Western Band individuals show a sharp decline beginning around 1860. These findings support negative secular trend occurring for both Cherokee bands where the environment made a detrimental impact; this is especially marked with the Western Cherokee band.

Theoretical comparison and experimental test of the secular and nonperturbative approaches on the ESR lineshapes of randomly oriented, anisotropic systems undergoing internal motion

NASA Astrophysics Data System (ADS)

Benetis, N. P.; Sjöqvist, L.; Lund, A.; Maruani, J.

The nuclear Zeeman and the electronic nonsecular parts of the spin Hamiltonian complicate the ESR lineshape of exchanging anisotropic spin systems by introducing, at high field, "forbidden" transitions and, at low field, additional shift and splitting. We compare the nonperturbative with the secular approach for such systems. The exchange is treated within the Kaplan-Alexander limit and both A and g tensors are included, resulting in spectrum asymmetry, in contrast to previous separate treatments. The two approaches are then used to simulate the powder spectrum of OCH 2COO - and compare the results to experimental spectra of an irradiated powder of ZnAc. The powder X-band spectra simulations using the secular approach appear to be accurate. For both the low-field (20 to 200 G) and the high-field (Q-band) regions, however, the nonsecular part of the electronic term and the nuclear Zeeman term, respectively, cannot be neglected. On the other hand, the approximate approach is much faster and consequently more appropriate for treating large, multisite exchanging systems.

Why religion deserves a place in secular medicine.

PubMed

Biggar, Nigel

2015-03-01

As a science and practice transcending metaphysical and ethical disagreements, 'secular' medicine should not exist. 'Secularity' should be understood in an Augustinian sense, not a secularist one: not as a space that is universally rational because it is religion-free, but as a forum for the negotiation of rival reasonings. Religion deserves a place here, because it is not simply or uniquely irrational. However, in assuming his rightful place, the religious believer commits himself to eschewing sheer appeals to religious authorities, and to adopting reasonable means of persuasion. This can come quite naturally. For example, Christianity (theo)logically obliges liberal manners in negotiating ethical controversies in medicine. It also offers reasoned views of human being and ethics that bear upon medicine and are not universally held-for example, a humanist view of human dignity, the bounding of individual autonomy by social obligation, and a special concern for the weak. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

The impact of German-speaking academicians on higher education in Turkey.

PubMed

Özduman, Koray; Güdük, Mustafa; Elmacı, Ilhan; Pamir, M Necmettin

2013-01-01

The transition from the medieval universities to the secular, second generation universities in Turkey occurred in the period from 1773 to 1945. The Ottoman Empire's efforts to establish a higher education system in the eighteenth and nineteenth centuries only aimed at modernization of the armed forces, and the civil effects on the general society were only secondary. After the Turkish Republic was founded in 1923, complete modernization of all institutions of society, including political, social, educational, economic, and law reforms, were initiated by the President Mustafa Kemal Atatürk. His establishment of the modern Istanbul University in Turkey was an experiment unforeseen in the history of education. Step by step, he created a new language, a new alphabet, achieved unified and secular education under government supervision, formed primary and secondary education to support higher education, took expert opinion on forming the new university, and finally established the modern university. German-speaking academicians have played a very important role during the creation of the modern secular university in Turkey. This is a short analysis of this period. Copyright © 2013 Elsevier Inc. All rights reserved.

Gravitational dynamos and the low-frequency geomagnetic secular variation.

PubMed

Olson, P

2007-12-18

Self-sustaining numerical dynamos are used to infer the sources of low-frequency secular variation of the geomagnetic field. Gravitational dynamo models powered by compositional convection in an electrically conducting, rotating fluid shell exhibit several regimes of magnetic field behavior with an increasing Rayleigh number of the convection, including nearly steady dipoles, chaotic nonreversing dipoles, and chaotic reversing dipoles. The time average dipole strength and dipolarity of the magnetic field decrease, whereas the dipole variability, average dipole tilt angle, and frequency of polarity reversals increase with Rayleigh number. Chaotic gravitational dynamos have large-amplitude dipole secular variation with maximum power at frequencies corresponding to a few cycles per million years on Earth. Their external magnetic field structure, dipole statistics, low-frequency power spectra, and polarity reversal frequency are comparable to the geomagnetic field. The magnetic variability is driven by the Lorentz force and is characterized by an inverse correlation between dynamo magnetic and kinetic energy fluctuations. A constant energy dissipation theory accounts for this inverse energy correlation, which is shown to produce conditions favorable for dipole drift, polarity reversals, and excursions.

Gravitational dynamos and the low-frequency geomagnetic secular variation

PubMed Central

Olson, P.

2007-01-01

Self-sustaining numerical dynamos are used to infer the sources of low-frequency secular variation of the geomagnetic field. Gravitational dynamo models powered by compositional convection in an electrically conducting, rotating fluid shell exhibit several regimes of magnetic field behavior with an increasing Rayleigh number of the convection, including nearly steady dipoles, chaotic nonreversing dipoles, and chaotic reversing dipoles. The time average dipole strength and dipolarity of the magnetic field decrease, whereas the dipole variability, average dipole tilt angle, and frequency of polarity reversals increase with Rayleigh number. Chaotic gravitational dynamos have large-amplitude dipole secular variation with maximum power at frequencies corresponding to a few cycles per million years on Earth. Their external magnetic field structure, dipole statistics, low-frequency power spectra, and polarity reversal frequency are comparable to the geomagnetic field. The magnetic variability is driven by the Lorentz force and is characterized by an inverse correlation between dynamo magnetic and kinetic energy fluctuations. A constant energy dissipation theory accounts for this inverse energy correlation, which is shown to produce conditions favorable for dipole drift, polarity reversals, and excursions. PMID:18048345

Recent terebratulide brachiopods: Do they faithfully record oceanographic conditions throughout ontogeny?

NASA Astrophysics Data System (ADS)

Kercher, P.; Carlson, S. J.

2012-12-01

Brachiopods have commonly been used to infer secular changes in ocean chemistry over the Phanerozoic Eon since Lowenstam (1961) concluded that Recent brachiopod calcite was precipitated in equilibrium with seawater. In order to infer paleoenvironmental conditions with confidence, however, the impact of potential kinetic and metabolic fractionation effects on the final isotopic signature, as it varies among individuals, must be determined. In this study, we analyzed the oxygen and carbon isotopic composition of closely spaced (~2/mm) samples of calcite along growth transects from individuals of the rhynchonelliform brachiopod, Laqueus californianus. By combining local oceanographic information with knowledge of brachiopod shell structure and growth patterns through ontogeny, in individuals of different ages from the same locality that died simultaneously, we can address the fidelity of brachiopod shell calcite as both an environmental proxy and a recorder of biological activity among conspecific individuals, in real time. This is an essential, but largely ignored, component in the paleoenvironmental interpretation of brachiopod shell calcite. In May 2011, more than 75 live L. californianus specimens were collected by Dr. J. Barry at Monterey Bay Aquarium Research Institute (MBARI) from Monterey Bay at 160 m water depth (36.7322N, 121.9739W) and generously given to us for use in this study. The specimens range in length from 5.75 to 46.16 mm, representing a range of ontogenetic ages. Water temperatures at 160 m range annually from 8C in the spring/summer upwelling season to 10C during the winter, while salinity fluctuates from 33.76 ppt in the winter to 34.11 ppt in the summer. Daily temperature and salinity data collected by MBARI over three decades allow us to calculate approximate equilibrium calcite values. We use these values to evaluate the claim that brachiopods mineralize in isotopic equilibrium with seawater throughout their lifespan with minimal intraspecific variation. We also use the MBARI data to correlate annual temperature fluctuations with δ18O trends within the calcite to estimate ontogenetic ages and growth rates. Full-grown adults were 10-11 years old when collected live, and grow an average of about 4 mm/year over their lifespan, growing faster before sexual maturity and slowing down after. The early results of the ontogenetic sampling tracts indicate calcite δ18O and δ13C values are strongly positively correlated. This relationship suggests kinetic fractionation effects are likely influencing the isotopic composition of the shells. Cyclic isotopic fluctuations are also recorded, in accordance with seasonal temperature oscillations in Monterey Bay, apparent even at 160 m depth. In most of the specimens, the amplitudes of the isotopic fluctuations exceed those of the predicted equilibrium values. Furthermore, our data support the claim made by other researchers that the outer primary layer of the shell is significantly depleted in both oxygen and carbon isotopes, below the range of equilibrium calcite. Isotopic oscillations across individuals align reasonably well both with each other and with ambient water temperature patterns. These results suggest that intraspecific variability is low in L. californianus and that these organisms are recording their environment similarly.

Iapetus' Geophysics: Rotation Rate, Shape, and Equatorial Ridge

NASA Technical Reports Server (NTRS)

Castillo-Rogez, J. C.; Matson, D. L.; Sotin, C.; Johnson, T. V.; Lunine, J. I.; Thomas, P. C.

2007-01-01

Iapetus has preserved evidence that constrains the modeling of its geophysical history from the time of its accretion until now. The evidence is (a) its present 79.33-day rotation or spin rate, (b) its shape that corresponds to the equilibrium figure for a hydrostatic body rotating with a period of approximately 16 h, and (c) its high, equatorial ridge, which is unique in the Solar System. This paper reports the results of an investigation into the coupling between Iapetus' thermal and orbital evolution for a wide range of conditions including the spatial distributions with time of composition, porosity, short-lived radioactive isotopes (SLRI), and temperature. The thermal model uses conductive heat transfer with temperature-dependent conductivity. Only models with a thick lithosphere and an interior viscosity in the range of about the water ice melting point can explain the observed shape. Short-lived radioactive isotopes provide the heat needed to decrease porosity in Iapetus? early history. This increases thermal conductivity and allows the development of the strong lithosphere that is required to preserve the 16-h rotational shape and the high vertical relief of the topography. Long-lived radioactive isotopes and SLRI raise internal temperatures high enough that significant tidal dissipation can start, and despin Iapetus to synchronous rotation. This occurred several hundred million years after Iapetus formed. The models also constrain the time when Iapetus formed because the successful models are critically dependent upon having just the right amount of heat added by SLRI decay in this early period. The amount of heat available from short-lived radioactivity is not a free parameter but is fixed by the time when Iapetus accreted, by the canonical concentration of Al-26, and, to a lesser extent, by the concentration of Fe-60. The needed amount of heat is available only if Iapetus accreted between 2.5 and 5.0Myr after the formation of the calcium aluminum inclusions as found in meteorites. Models with these features allow us to explain Iapetus? present synchronous rotation, its fossil 16-h shape, and the context within which the equatorial ridge arose.

Explanation of the anomalous secular increase of the moon orbit eccentricity by the new theory of gravitation (NTG)

NASA Astrophysics Data System (ADS)

Ziefle, Reiner Georg

2013-03-01

Present day gravitational physics experiences a huge success in obtaining better and better experimental results. In some cases, the observations do not fit with the present knowledge of established physics. Phenomena, like the increase of the Astronomical Unit by 7 m per century or the so-called anomalous secular increase of the eccentricity of the lunar orbit by about 9 × 10^-12 per year, which can neither be explained by Einstein's Theory of General Relativity, nor by the Newtonian Theory of Gravitation, can be explained by the New Theory of Gravitation

Stochastic Growth of Ion Cyclotron And Mirror Waves In Earth's Magnetosheath

NASA Technical Reports Server (NTRS)

Cairns, Iver H.; Grubits, K. A.

2001-01-01

Electromagnetic ion cyclotron and mirror waves in Earth's magnetosheath are bursty, have widely variable fields, and are unexpectedly persistent, properties difficult to reconcile with uniform secular growth. Here it is shown for specific periods that stochastic growth theory (SGT) quantitatively accounts for the functional form of the wave statistics and qualitatively explains the wave properties. The wave statistics are inconsistent with uniform secular growth or self-organized criticality, but nonlinear processes sometimes play a role at high fields. The results show SGT's relevance near marginal stability and suggest that it is widely relevant to space and astrophysical plasmas.

Can Satellite Geodesy Disentangle Holocene Rebound and Present-Day Glacier Balance Signatures?

NASA Technical Reports Server (NTRS)

Irvins, E.; James, T.; Yoder, C.

1995-01-01

The secular drift of the precession of the ascending node of the LAGOES -1 satellite is apparently linked to the Earth s paleoclimate through the slow viscous response of the mantle to ice sheet/ocean mass transfer during the last great continental deglaciation . The secular node acceleration is particularly sensitive to the longest wavelengths of the paleo -surface loading that have been memorized by the mantle glacio -isostatic flow. Tide gauge records for the last 130 years show a post-glacial rebound-corrected sea-level rise of 2.4 n 0.9 mm yr-1.

Mercury's spin-orbit model and signature of C/MR2

NASA Astrophysics Data System (ADS)

Rambaux, N.; Bois, E.

2003-04-01

The upcoming missions, MESSENGER (Solomon etal 2001, Planet. Space Sci 49) and Bepi Colombo (Milani etal 2001, Planet. Space Sci 49) with onboard instrumentation capable of measuring the rotational parameters stimulate the objective to reach an accurate theory of the rotational motion of Mercury. Our work deals with the physical and dynamical causes that induce librations around an equilibrium state defined by the 3:2 spin-orbit resonance of Mercury. In order to integrate the spin-orbit motion of Mercury, we have used our gravitational model of the solar System including the Moon's spin-orbit motion. This model, called SONYR (acronym of Spin-Orbit N-bodY Relativistic model), was previously built by Bois, Journet and Vokrouhlicky in accordance with the requirements of the Lunar Laser Ranging observational accuracy (see for instance a review by Bois 2000, C. R. Acad. Sci. Série IV, or Bois and Vokrouhlický 1995). Using the model, the present study is devoted to the main perturbations acting on the spin-orbit motion of Mercury such as the planetary interactions (and their hierarchy) and the dynamical figure of the planet. The effect of the torque of Venus is 105 times smaller in magnitude than the one due to the Sun. Moreover, the complete rotation of Mercury exhibits two proper frequencies, namely 15.825 and 1089 years, and one secular variation of 271043 years which is due to the nodal precession between the equatorial plane of Mercury and its orbital plane. It is the second synchronism of Mercury mentioned by Beletski in 1986. We have made into evidence that the 3:2 resonance of Mercury is preserved by this second synchronism, which can be understood as a spin-orbit secular resonance. We have shown that the secular resonance variable ψ - Ω librates with a frequency of 1089 years. Our model integration starts with an initial obliquity of 1.65 arcminute (re-evaluate from the Cassini state) and gives an amplitude of libration in longitude of the order of 20 arcseconds, which is in agreement with Balogh and Giamperi (2002, Rep. Prog. Phys. 65). Besides, we have computed in the Hermean librations the impact of the variation of the greatest principal moment of inertia, cm2. The maximal signature on the obliquity is then 1.4 mas (milliarsecond) on the 176 day period, and the one on the libration in longitude is 0.4 mas on the 87.9 day period, resulting from an increase of the cm2 value of 1%. These values have to be understood as upper bounds of such signatures. These two effects permit to contribute to precise the relationship between the cm2 coefficient and the internal structure of Mercury. References : Balog, A., and Giamperi, G., 2002, Rep. Prog. Phys. 65, 529-560. Beletski, V, 1986, "Essais sur le Mouvement des Corps Cosmiques", Mir (ed), Moscou. Bois, E., 2000, C. R. Acad. Sci. Paris, t. 1, Série IV, 809-823. Bois, E., and Vokrouhlický, D., 1995, Astronomy and Astrophysics 300, 559-567. Milani, A., Vokrouhlicky, D., and Bonanno, C., 2001, Planet. Space Sci 49, 1579. Solomon, etal, 2001, Planet. Space Sci 49, 1445.

U-Sries Disequilibra in Soils, Pena Blanca Natural Analog, Chihuahua, Mexico

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

D. French; E. Anthony; P. Goodell

2006-03-16

The Nopal I uranium deposit located in the Sierra Pena Blanca, Mexico. The deposit was mined in the early 1980s, and ore was stockpiled close by. This stockpile area was cleared and is now referred to as the Prior High Grade Stockpile (PHGS). Some of the high-grade boulders from the site rolled downhill when it was cleared in the 1990s. For this study soil samples were collected from the alluvium surrounding and underlying one of these boulders. A bulk sample of the boulder was also collected. Because the Prior High Grade Stockpile had no ore prior to the 1980s amore » maximum residence time for the boulder is about 25 years, this also means that the soil was at background as well. The purpose of this study is to characterize the transport of uranium series radionuclides from ore to the soil. Transport is characterized by determining the activities of individual radionuclides and daughter to parent ratios. Isotopes of the uranium series decay chain detected include {sup 210}Pb, {sup 234}U, {sup 230}Th, {sup 226}Ra, {sup 214}Pb, and {sup 214}Bi. Peak areas for each isotope are determined using gamma-ray spectroscopy with a Canberra Ge (Li) detector and GENIE 2000 software. The boulder sample is close to secular equilibrium when compared to the standard BL-5 (Beaver Lodge Uraninite from Canada). Results for the soils, however, indicate that some daughter/parent pairs are in secular disequilibrium. These daughter/parent (D/P) ratios include {sup 230}Th/{sup 234}U, which is greater than unity, {sup 226}Ra/{sup 230}Th, which is also greater than unity, and {sup 210}Pb/{sup 214}Bi, which is less than unity. The gamma-ray spectrum for organic material lacks {sup 230}Th peaks, but contains {sup 234}U and {sup 226}Ra, indicating that plants preferentially incorporate {sup 226}Ra. Our results, combined with previous studies require multistage history of mobilization of the uranium series radionuclides. Earlier studies at the ore zone could limit the time span for mobilization only to a few thousand years. The contribution of this study is that the short residence time of the ore at the Prior High Grade Stockpile requires a time span for mobilization of 20-30 years.« less

Mechanism of secular increasing of mean gravity in Northern hemisphere and secular decreasing of mean gravity in Southern hemisphere

NASA Astrophysics Data System (ADS)

Barkin, Yu. V.; Ferrandiz, J. M.

2009-04-01

Mechanism. To present time the observant data in various geosciences more and more confidently testify for the benefit of existence of secular drift of the Earth core in the direction of North Pole. 1). So the superfluous mass of a displaced core relatively to elastic mantle, obviously, results in displacement of the centre of mass of the Earth with respect to basic system of coordinates on a surface of the Earth also in northern direction. Methods of a space geodesy let us confidently to determine drift of the centre of mass to the north with velocity about 0.5 - 1.0 cm/yr. The fundamental phenomenon of drift of the centre of mass and the core of the Earth has been predicted in 1995 (Barkin, 1995) at the analysis of secular change of the pear-shaped form of the Earth in present epoch (velocity of drift of the centre of mass of the Earth was appreciated in 1.8 +/-1.0 cm/yr in the direction of North Pole of the Earth). For an explanation of observably drift of the centre of mass at once the model of drift of the core was offered and the geodynamic model of forced relative displacements and wanderings of interacting shells of the Earth under action of a gravitational attraction of external celestial bodies (Barkin, 1996, 2002) has been developed. 2). The core makes slow secular drift and cyclic displacements. Predicted spectrum of oscillations of the centre of mass of the Earth and its core (Barkin, 2001) has received precise confirmation as a result of the Fourier analysis of temporal series for coordinates of a geocenter (Kaftan, Tatevian, 2003; Barkin, Vilke, 2004; Barkin, Lyubushin, Zotov, 2007). 3). The displaced core makes active all bouquet of natural processes in all shells of the Earth (including an atmosphere, ocean and internal shells), varying in the certain rhythms and styles the tension conditions of shells, their thermodynamic conditions etc. The core as though "conducts" by all planetary processes at once. From here take the origin such fundamental phenomena as cyclicity and synchronism of planetary natural processes, inversion of activity of natural processes in opposite hemispheres. Numerous confirmations give the extensive data of every possible geophysical observations. The phenomenon of synchronism in annual variations of activity of various natural processes is rather brightly expressed - their phases are precisely synchronized, and the periods of extreme activity (or passivity) fall to February - March or August - September. In daily variations of natural processes similar laws are observed. Here we speak about modern processes, but similar laws take place in various time scales, including geological. In the given report we shall concentrate on the analysis of possible secular variations of a gravity at displacement of an external core (of its centre of mass) relatively to the elastic mantle. The analysis has shown, that gravitational influence of displaced superfluous mass of the core are a major factor of secular variations of a gravity. However the displaced core causes directed redistribution of atmospheric masses from a southern hemisphere in northern, and also complex slow redistribution of oceanic masses. Increase of loading of atmospheric and oceanic masses on an elastic crust of northern hemisphere results in its slow lowering. Return processes should observed in a southern hemisphere. All listed factors, certainly, directly influence variations of a gravity. In a more comprehensive sense redistribution of all fluid masses, including climatic character also result in changes of a gravity. Hemispheres mean secular trends of gravity. For an estimation of a role of factors of redistribution of air and fluid masses in variations of a gravity the point model of redistribution of masses of the Earth (Barkin, 2001), obtained very effective applications at studying of fundamental problems of geodynamics, has been used. Let's emphasize, that the Earth is active dynamic object at which activity in the certain regions (for example, in subduction zones, a hilly terrain, a zone of volcanism etc.) at times is more brightly shown. Therefore the steadfast attention should be paid to local factors of changes of a gravity. In result the phenomenon of inversion changes of a gravity in northern and southern hemispheres has been predicted: mean value of a gravity in northern hemisphere accrues with velocity 1.36 micro gals in year (mGal), and in southern decreases with the same velocity. Secular variations of a gravity depend from latitude and on equator (within the framework of considered model) change a sign: dg=2.72tsinф micro gals in year (mGal), where ф is a latitude of a place of observations, t is the time in years (Barkin, 2005). The data of gravimetric measurements at the European stations: Metsahovi, Potsdam, Moha, Vienna, Wettzell, Strastburg, Medicina etc., in Asia and Australia: Eshashi, Canberra etc., in Northern and South America: Bolder (Colorado), Patagonia (Argentina) etc., and also in Antarctic Region (station Syowa), will well be coordinated to the theoretical values of secular variations of a gravity predicted earlier at the specified stations. Gravity trends are studied and evaluated after removal effects of tides, local pressure and polar motion. The secular gravity variation at Potsdam is evaluated in 2.1 mGal/yr. During 1976-1986 the similar tendency - gravity trend with velocity 2.6 mGal/yr (absolute measurements) here have been observed. The similar tendency has been determined on measurements on superconducting gravimeters during 1993-1997: 2.3-2.5 mGal/yr (Neumeyer and Dittfeled, 1997). For more extensive period of observation (Neumayer, 2002) the similar result for gravity trend has been obtained. Observable annual variations of a gravity are characterized by amplitude about 3 mGal (on our model it is 3.5 mGal). Observations at Syowa station have been confirmed the developed model. Here it was expected negative gravity trend - decreasing of gravity with velocity -2.54 mGal/yr, that have actually confirmed SG observations during 1995-1998: -2.4 mGal/yr (Sato et al., 2001). Amplitudes of an annual and semi-annual variations approximately make 4.8 mGal/yr and 0.8 mGal/yr (theoretical values: 4.2 mGal/yr and 0.95 mGal/yr). References Barkin Yu.V. (2002) Explanation of endogenous activity of planets and satellites and its cyclicity. Izvestia cekzii nauk o Zemle. Rus. Acad. of Nat. Sciences, Issue 9, December 2002, M.: VINITI, pp. 45-97. In Russian. Barkin Yu.V., Ferrandiz J.M. (2008) Phenomenon of secular increasing of mean gravity in Northern hemisphere and secular decreasing of gravity in Southern hemisphere; predictions and new confirmations. EGU General Assembly (Vienna, Austria, 13-18 April 2008). Geophysical Research Abstracts, EGU General Assembly 2008. Vol. 10, EGU2008-A-10506.

Emulsion Liquid Membrane Removal of Arsenic and Strontium from Wastewater: AN Experimental and Theoretical Study.

NASA Astrophysics Data System (ADS)

Zhou, Ding-Wei

The emulsion liquid membrane (ELM) technique has been successfully applied on the removal of arsenic (As) from metallurgical wastewater and the removal of strontium (Sr) from radioactive wastewater. This study consisted of experimental work and mathematical modeling. Extraction of arsenic by an emulsion liquid membrane was firstly investigated. The liquid membrane used was composed of 2-ethylhexyl alcohol (2EHA) as the extractant, ECA4360J as the surfactant, and Exxsol D-80 solvent (or heptane) as the diluent. The sulfuric acid and sodium hydroxide solutions were used as the external and internal phases, respectively. The arsenic removal efficiency reached 92% within 15 minutes in one stage. Extraction and stripping chemistries were postulated and investigated. It was observed that extraction efficiency and rate increase with the increase of acidic strength and alkali strength in the external and internal phases, respectively. It was also observed that the removal selectivity of arsenic over copper is extremely high. Strontium-90 is one of the major radioactive metals appearing in nuclear wastewater. The emulsion liquid membrane process was investigated as a separation method by using the non-radioactive ^{87}Sr as its substitute. In our study, the membrane phase was composed of di-(2-ethylhexyl) phosphoric acid (D2EHPA) as the extractant, ECA4360J as the surfactant and Exxsol D-80 as the diluent. A sulfuric acid solution was used in the internal phase as the stripping agent. The pH range in the external phase was determined by the extraction isotherm. Under the most favorable operating condition, the strontium removal efficiency can reach 98% in two minutes. Mass transfer of the emulsion liquid membrane (ELM) system was modeled mathematically. Our model took into account the following: mass transfer of solute across the film between the external phase and the membrane phase, chemical equilibrium of the extraction reaction at the external phase-membrane interface, simultaneous diffusion of the solute-carrier complex inside the globule membrane phase and stripping of the complex at the membrane-internal phase interface, chemical equilibrium of the stripping reaction at the membrane-internal phase interface and leakage of the solute from the internal phase to the external phase. Resulting simultaneous partial differential equations were solved analytically by the Laplace transform method. Four dimensionless groups were found with special physical meanings to characterize the emulsion liquid membrane systems. It not only predicted the concentration of solute in the external phase versus time, but also gave the concentration profile inside the membrane globule and the interfacial concentration at the external-membrane phase interface at different time. The model predicted very well the experimental data obtained from the removal of arsenic and strontium by the emulsion liquid membranes.

CHRONOLOGICAL CONSTRAINTS ON FLUID CIRCULATION IN MESOZOIC FORMATIONS OF THE EASTERN PART OF THE PARIS BASIN INFERRED FROM U-Pb DATING OF SECONDARY INFILLING CARBONATES

NASA Astrophysics Data System (ADS)

Pisapia, C.; Deschamps, P.; Hamelin, B.; Buschaert, S.

2009-12-01

The French agency for nuclear waste management (ANDRA) developed an Underground Research Laboratory in the Mesozoic formations of Eastern part of the Paris Basin (France) to assess the feasibility of a high-level radioactive wastes repository in sedimentary formations. The target host formation is a low-porosity detrital argillite (Callovo-Oxfordian) embedded between two shelf limestones formations (of Bajocian-Bathonian and Oxfordian-Kimmeridgian ages). These formations are affected by fracture networks, likely inherited mainly from the Eocene-Oligocene extension tectonics, also responsible of the Rhine graben formation in the same region. The limestones have very low permeability, the primary and secondary porosity being infilled by secondary carbonated minerals. The inter-particle porosity is filled with euhedral calcite spar cements. Similarly, macro-cavities and connected micro-fractures are almost sealed by euhedral calcite. Geochemical evidences (δ18O) suggest that the secondary carbonates likely derived from a common parent fluid (Buschaert et al., 2004, Appl. Geochem. (19) 1201-1215p). This late carbonated precipitation phase is responsible for the intense cementation of the limestone formations and bears witness of a major phase of fluids circulation that marked the late diagenetic evolution of the system. Knowledge of the chronology of the different precipitation phases of secondary minerals is thus of critical importance in order to determine the past hydrological conditions of the geological site. The aim of this study is to provide chronological constraints on the secondary carbonate mineral precipitation using U/Th and U/Pb methods. Analyses are performed on millimeter to centimeter scale secondary calcites collected within fractures outcropping in the regional fault zone of Gondrecourt and in cores from the ANDRA exploration-drilling program. Preliminary U-Th analyses obtained on secondary carbonates from surface fractures infillings yield secular equilibrium composition, indicating that the precipitation phase was older than 650 ky. U-Pb measurements were performed on a VG sector Thermal Ionization Mass Spectrometer (TIMS) using a 205Pb-236U-233U-229Th spike. Pb contents are generally very low, between 3 and 20 ppb, while U contents are more variable, leading to μ = 238U/204Pb up to ~600. Sub-samples with high μ show radiogenic 206Pb/204Pb ratio, but at this stage isochrons generally show high scatter. These U-Pb data however are consistent with an Eocene-Oligocene period for the late carbonates precipitation phase. We will discuss the different processes that may be responsible for these errorchrons (i.e. heterogeneities in the initial isotopic composition; multi-stage growth) as well as the chronological constraints that can be drawn from these data.

SECULAR EVOLUTION OF BINARIES NEAR MASSIVE BLACK HOLES: FORMATION OF COMPACT BINARIES, MERGER/COLLISION PRODUCTS AND G2-LIKE OBJECTS

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

Prodan, Snezana; Antonini, Fabio; Perets, Hagai B., E-mail: sprodan@cita.utoronto.ca, E-mail: antonini@cita.utoronto.ca

2015-02-01

Here we discuss the evolution of binaries around massive black holes (MBHs) in nuclear stellar clusters. We focus on their secular evolution due to the perturbation by the MBHs, while simplistically accounting for their collisional evolution. Binaries with highly inclined orbits with respect to their orbits around MBHs are strongly affected by secular processes, which periodically change their eccentricities and inclinations (e.g., Kozai-Lidov cycles). During periapsis approach, dissipative processes such as tidal friction may become highly efficient, and may lead to shrinkage of a binary orbit and even to its merger. Binaries in this environment can therefore significantly change theirmore » orbital evolution due to the MBH third-body perturbative effects. Such orbital evolution may impinge on their later stellar evolution. Here we follow the secular dynamics of such binaries and its coupling to tidal evolution, as well as the stellar evolution of such binaries on longer timescales. We find that stellar binaries in the central parts of nuclear stellar clusters (NSCs) are highly likely to evolve into eccentric and/or short-period binaries, and become strongly interacting binaries either on the main sequence (at which point they may even merge), or through their later binary stellar evolution. The central parts of NSCs therefore catalyze the formation and evolution of strongly interacting binaries, and lead to the enhanced formation of blue stragglers, X-ray binaries, gravitational wave sources, and possible supernova progenitors. Induced mergers/collisions may also lead to the formation of G2-like cloud-like objects such as the one recently observed in the Galactic center.« less

Steady induction effects in geomagnetism. Part 1C: Geomagnetic estimation of steady surficial core motions: Application to the definitive geomagnetic reference field models

NASA Technical Reports Server (NTRS)

Voorhies, Coerte V.

1993-01-01

In the source-free mantle/frozen-flux core magnetic earth model, the non-linear inverse steady motional induction problem was solved using the method presented in Part 1B. How that method was applied to estimate steady, broad-scale fluid velocity fields near the top of Earth's core that induce the secular change indicated by the Definitive Geomagnetic Reference Field (DGRF) models from 1945 to 1980 are described. Special attention is given to the derivation of weight matrices for the DGRF models because the weights determine the apparent significance of the residual secular change. The derived weight matrices also enable estimation of the secular change signal-to-noise ratio characterizing the DGRF models. Two types of weights were derived in 1987-88: radial field weights for fitting the evolution of the broad-scale portion of the radial geomagnetic field component at Earth's surface implied by the DGRF's, and general weights for fitting the evolution of the broad-scale portion of the scalar potential specified by these models. The difference is non-trivial because not all the geomagnetic data represented by the DGRF's constrain the radial field component. For radial field weights (or general weights), a quantitatively acceptable explication of broad-scale secular change relative to the 1980 Magsat epoch must account for 99.94271 percent (or 99.98784 percent) of the total weighted variance accumulated therein. Tolerable normalized root-mean-square weighted residuals of 2.394 percent (or 1.103 percent) are less than the 7 percent errors expected in the source-free mantle/frozen-flux core approximation.

Secular obliquity variations for Ceres

NASA Astrophysics Data System (ADS)

Bills, Bruce; Scott, Bryan R.; Nimmo, Francis

2016-10-01

We have constructed secular variation models for the orbit and spin poles of the asteroid (1) Ceres, and used them to examine how the obliquity, or angular separation between spin and orbit poles, varies over a time span of several million years. The current obliquity is 4.3 degrees, which means that there are some regions near the poles which do not receive any direct Sunlight. The Dawn mission has provided an improved estimate of the spin pole orientation, and of the low degree gravity field. That allows us to estimate the rate at which the spin pole precesses about the instantaneous orbit pole.The orbit of Ceres is secularly perturbed by the planets, with Jupiter's influence dominating. The current inclination of the orbit plane, relative to the ecliptic, is 10.6 degrees. However, it varies between 7.27 and 11.78 degrees, with dominant periods of 22.1 and 39.6 kyr. The spin pole precession rate parameter has a period of 205 kyr, with current uncertainty of 3%, dominated by uncertainty in the mean moment of inertia of Ceres.The obliquity varies, with a dominant period of 24.5 kyr, with maximum values near 26 degrees, and minimum values somewhat less than the present value. Ceres is currently near to a minimum of its secular obliquity variations.The near-surface thermal environment thus has at least 3 important time scales: diurnal (9.07 hours), annual (4.60 years), and obliquity cycle (24.5 kyr). The annual thermal wave likely only penetrates a few meters, but the much long thermal wave associated with the obliquity cycle has a skin depth larger by a factor of 70 or so, depending upon thermal properties in the subsurface.

On the Existence of Regular and Irregular Outer Moons Orbiting the Pluto–Charon System

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

Michaely, Erez; Perets, Hagai B.; Grishin, Evgeni

The dwarf planet Pluto is known to host an extended system of five co-planar satellites. Previous studies have explored the formation and evolution of the system in isolation, neglecting perturbative effects by the Sun. Here we show that secular evolution due to the Sun can strongly affect the evolution of outer satellites and rings in the system, if such exist. Although precession due to extended gravitational potential from the inner Pluto–Charon binary quench such secular evolution up to a {sub crit} ∼ 0.0035 au (∼0.09 R {sub Hill} the Hill radius; including all of the currently known satellites), outer orbitsmore » can be significantly altered. In particular, we find that co-planar rings and satellites should not exist beyond a {sub crit}; rather, satellites and dust particles in these regions secularly evolve on timescales ranging between 10{sup 4} and 10{sup 6} years, and quasi-periodically change their inclinations and eccentricities through secular evolution (Lidov–Kozai oscillations). Such oscillations can lead to high inclinations and eccentricities, constraining the range where such satellites (and dust particles) can exist without crossing the orbits of the inner satellites or crossing the outer Hill stability range. Outer satellites, if such exist are therefore likely to be irregular satellites, with orbits limited to be non-circular and/or highly inclined. Current observations, including the recent data from the New-Horizons mission explored only inner regions (<0.0012 au) and excluded the existence of additional satellites; however, the irregular satellites discussed here should reside farther, in the yet uncharted regions around Pluto.« less

Paleomagnetic directions and thermoluminescence dating from a bread oven-floor sequence in Lübeck (Germany): A record of 450 years of geomagnetic secular variation

NASA Astrophysics Data System (ADS)

Schnepp, Elisabeth; Pucher, Rudolf; Goedicke, Christian; Manzano, Ana; Müller, Uwe; Lanos, Philippe

2003-02-01

A record of about 450 years of geomagnetic secular variation is presented from a single archaeological site in Lübeck (Germany) where a sequence of 25 bread oven floors has been preserved in a bakery from medieval times until today. The age dating of the oven-floor sequence is based on historical documents, 14C-dating and thermoluminescence dating. It confines the time interval from about 1300 to 1800 A.D. Paleomagnetic directions have been determined from each oven floor by means of 198 oriented hand samples. After alternating field as well as thermal demagnetization experiments, the characteristic remanent magnetization direction was obtained using principal component analysis. The mean directions of 24 oven floors are characterized by high Fisherian precision parameters (>146) and small α95 confidence limits (1.2°-4.6°). For obtaining a smooth curve of geomagnetic secular variation for Lübeck, a spherical spline function was fitted to the data using a Bayesian approach, which considers not only the obtained ages, but also stratigraphic order. Correlation with historical magnetic records suggests that the age estimation for the upper 10 layers was too young and must date from the end of the sixteenth to the mid of the eighteenth century. For the lowermost 14 layers, dating is reliable and provides a secular variation curve for Germany. The inclination shows a minimum in the fourteenth century and then increases by more than 10°. Declination shows a local minimum around 1400 A.D. followed by a maximum in the seventeenth century. This is followed by the movement of declination about 30° to western directions.

Trends and determinants of the Flynn effect in cognitive functioning among older individuals in 10 European countries.

PubMed

Hessel, Philipp; Kinge, Jonas M; Skirbekk, Vegard; Staudinger, Ursula M

2018-05-01

Although cognitive performance levels in old age have increased in most countries, recent evidence documents a slowing down or even decline in cohort gains in highly developed countries. The aim of this study was to assess trends and determinants in secular cohort gains in cognitive functioning among older individuals and whether cohort gains are levelling off in most advanced countries. Data for individuals aged between 50 and 84 years from the Survey of Health, Ageing and Retirement in Europe in 10 European countries between 2004 and 2013 (n=92 739) were used to assess country and age-specific changes in immediate word recall. Multivariate random intercept models were used to assess associations between secular cohort changes in immediate word recall, initial performance levels and changes in country-level socio-demographic characteristics. Performance in immediate word recall improved in all countries between 2004 and 2013 (from 4.40 to 5.08 words, P<0.05). However, secular cohort gains were significantly smaller in countries with initially higher performance levels (coeff.=-0.554, 95% CI -0.682 to -0.426). Changes in socio-demographic and health conditions, including decreases in cardiovascular disease, physical activity and educational achievement, were associated with larger secular cohort gains. Results may either reflect that some countries are approaching the limits of cognitive plasticity, are slowing in their progress or that societal structures have not yet been optimised to improve cognitive abilities in midlife and beyond, or a combination of these interpretations. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Historical Improvements in Well-Being Do Not Hold in Late Life: Birth- and Death-Year Cohorts in the US and Germany

PubMed Central

Hülür, Gizem; Ram, Nilam; Gerstorf, Denis

2015-01-01

One key objective of lifespan research is to examine how individual development is shaped by the historical time people live in. Secular trends favoring later-born cohorts on fluid cognitive abilities have been widely documented, but findings are mixed for well-being. It remains an open question whether secular increases in well-being seen in earlier phases of life also manifest in the last years of life. To examine this possibility, we made use of longitudinal data obtained from the mid 1980s until the late 2000s in two large national samples in the US (Health and Retirement Study, HRS) and Germany (German Socio-Economic Panel, SOEP). We operationally defined historical time from two complementary perspectives: birth-year cohorts based on the years people were born (earlier: 1930s vs. later: 1940s); and death-year cohorts based on the years people died (earlier: 1990s vs. later: 2000s). To control for relevant covariates, we used case-matched groups based on age (at death) and education and covaried for gender, health, and number of observations. Results from both countries revealed that well-being in old age was indeed developing at higher levels among later-born cohorts. However, for later-deceased cohorts, no evidence for secular increases in well-being was found. To the contrary, later-dying SOEP participants reported lower levels of well-being at age 75 years and 2 years prior to death and experienced steeper late-life declines. Our results suggest that secular increases in well-being observed in old age do not manifest in late-life where “manufactured” survival may be exacerbating age- and mortality-related declines. PMID:26098582

Explanation of observable secular variations of gravity and alternative methods of determination of drift of the center of mass of the Earth

NASA Astrophysics Data System (ADS)

Barkin, Yury

2010-05-01

The summary. On the basis of geodynamic model of the forced relative displacement of the centers of mass of the core and the mantle of the Earth the secular variations of a gravity and heights of some gravimetry stations on a surface of the Earth have ben studied. At the account of secular drift of the center of mass of the Earth which on our geodynamic model is caused by the unidirectional drift of the core of the Earth relatively to the mantle, the full explanation is given to observable secular variations of a gravity at stations Ny-Alesund (Norway), Churchill (Canada), Medicine (Italy), Sayowa (Antarctica), Strastburg (France), Membach (Belgium), Wuhan (China) and Metsahovi (Finland). Two new methods of determination of secular drift of the center of mass of the Earth, alternative to classical method of a space geodesy are offered: 1) on the basis of gravimetry data about secular trends of a gravity at the stations located on all basic regions of the Earth; 2) on the basis of the comparative analysis of altimetry and coastal data about secular changes of sea level also in basic regions of ocean. 1. Secular drift of the center of mass of the core and the center of mass of the Earth. A secular drift of the center of mass of the Earth to the North relatively to special center O on an axis of rotation of the Earth for which the coefficient of third zonal harmonic J3' = 0, has been predicted in the author work [1]. A drift in a direction to a geographical point (pole P) 70°0 N and 104°3 E has been established for the first time theoretically - as a result of the analysis of the global directed redistribution of masses of the Earth, explaining the observed secular drift of the pole of an axis of rotation of the Earth and not tidal acceleration of its axial rotation [2]. In [1] velocity of drift it has been estimated in 1-2 cm/yr. For specified center O the figure of a planet is as though deprived of pure-shaped form (J3' = 0). And in this sense the point O can be conditionally corresponded to the geocenter of the Earth approximately determined by position of stations of satellite observations, as the center of certain mantle systems of coordinates Oxyz. For an explanation of such significant drift of the center of mass of the Earth the mechanism of the unidirectional displacement of the core of the Earth (and its center of mass) relatively to a viscoelastic mantle [1, 2] has been offered. The next years attempts of determination of velocity of secular drift of the center of mass in the mantle reference frame by methods of a space geodesy on the basis of precision satellite observations were repeatedly undertaken. In our work [3] for determination of a trend of the center of mass the data of the International Service of Rotation of the Earth (IERS) for satellite observations of system DORIS have been used. For components of velocity of drift in geocentric Greenwich system of coordinates for period 1999-2007 estimations have been obtained: on coordinate x) -1.46 mm/yr, y) 0.79 mm/yr and z) 5.29 mm/yr (errors of the specified estimations make 5-10 %). The velocity of trend of the center of mass of the Earth and its direction are characterized by values: 5.54 mm/yr; latitude 72°6 N and a longitude 118°4 E. The direction of displacement of the center of mass will well be coordinated with a direction predicted earlier theoretically [2]: latitude 70° N and a longitude 104° E. We shall emphasize, that observable redistributions of superficial masses of the Earth explain only small part of observable displacement of the center of mass. It testifies in favour of a reality of secular relative displacement of the core and the mantle of the Earth. 2 Secular drift of the core to the North and variations of a gravity on the Earth surface. The displaced core of the Earth is characterized by the large superfluous mass approximately in 16.7 masses of the Moon. The superfluous mass is ditermined by contrast values of average densities of the core and the mantle and makes 19.32 % of mass of full the Earth. At displacement of the core relatively to the viscous-elastic mantle its superfluous mass causes observable drift of the center of mass, and also leads to changes of a gravity on the surface of the planet. Except for it the gravitational attraction of a displaced core causes deformations of all layers of the mantle, including a superficial layer. The deformed mantle produses some additional gravitational potential which gives the additional contribution to value of a gravity. Thus, noted factors lead to a secular variation of a gravity which is described by the simple formula [2]: dot g = 2gμmc-(1- h-2- 0.5k-2)ρdot-sin?, μmc = 0.1932m ⊙, g = 9.82022 m -s2 m ⊙ r⊙ (1) Here μmc = 0.1932m⊙ is a superflous mass of the Earth core in the masses of the Earth m⊙. g is an acceleration of free falling. k-2 and h-2 are Love numbers of the order (-2). ρdot is a velocity of the secular drift of the center of mass of the core relatively to the center of mass of the mantle. ?is an angle between dirtection to the pole P (in a direction to which the core of the Earth or its center of mass drifts), and direction to gravimetric station. For rough estimates of gravimetric effects as pole P the North Pole of the Earth has been accepted. Thus ? = ?-2 - φis a co-latitude. At more exact description of the core drift (or the center of mass drift) an angle? is determined by formula: cos? = cosφP cosφcos(λP - λ) + sinφP sinφ, where φP and λP is a latitude and longitude of pole P; φ and λ is a latitude and longitude of station. The Love numbers of the order (-2) in first have been evaluated in the paper [4] and have small values: k-2=-0.005004 and h-2=0.0062154. Approximately we can put ρdot m⊙ = μmcṙC, where ṙC is a velocity of the drift of the center of mass of the Earth. Then, neglecting small effects, for a variation of gravity (1) we obtain a following expression: ? r = 2ṙCg cos?-r⊙. Leaning on results of works [2], [3], we shall accept the following values of parameters of drift of the center of mass: ṙC=5.54 mm/yr, φP=70°0 N, λP=104°3 E. On the other hand a displacement of the center of mass of the Earth leads to effect of slow change of heights of gravimetric station: ḣ = -?dotC cos? = -5.54 × cos? mm/yr. Errors in determination of the specified characteristics in the given work we shall neglect. Besides the gravitational attraction of a displaced core leads also to effect of increase of horizontal component of gravitational force of an attraction of the Earth on its surface directed to the North along the corresponding meridian with pole P. For any point of a surface of the Earth this component of force is determined by the formula ?φ = ṙCg sin?-r⊙ and has positive values. And the maximal values ?φ are reached on equator, which plane is orthogonal to axes of drift of the core OP. Thus, final working formulas for studying of secular variations of components of force of a gravitational attraction of the Earth and for a variation of the heights caused by a drift of the center of mass of the Earth become: ?r = 1.74cos?-r⊙ ?Gal/yr, ?φ = 0.87sin?-r⊙ ?Gal/yr, ḣ = -5.54cos?-r⊙ mm/yr. Calculated values of mentioned gravimetric characteristics (2) for the wide list of gravimetry stations are resulted in work [5] and used in the given work. 3 Explanation of observable secular variations of a gravity and heights on gravimetric stations. We have been analysed observed variations of a gravity and heights available and accessible to us, namely their secular changes, for 8 known gravimetry stations. The periods of observations at mentioned stations make the order of 5-10 years, i.e. are not greater, but nevertheless the obtained results unequivocally testify in favour of that the basic contribution to secular variations of a gravity gives the drifting core of the Earth (by means of direct gravitational influence and due to a contribution to corresponding variations of heights). In the given work we did not consider other factors influencing on gravimetric measurements (superficial redistributions of fluid masses, variations of coefficients of the second and higher harmonics of a geopotential, etc.). As an example here we shall analyse secular variations of a gravity and heights at Ny-Alesund station (geographical coordinates: 78°93 N, 11°87 E, ? =23°16). Linear trends of a gravity and height observable at this station make -2.5±0.9 ?Gal/yr and + (6.9±0.9) mm/yr, accordingly, during 1998-2002 (Sato et.al., 2006). On our model a slow closing of the core to the Ny-Alesund station causes a positive variation of a gravity in 1.60 ?Gal/yr and a negative variation of height of station in -5.09 mm/yr [5]. These data testify a deformation of a surface of the Earth in area of station with a velocity +11.99±0.9 mm/yr owing to which the gravity tests a negative variation -3.74±0.28 ?Gal/yr. Putting effects of a variation of a gravity because of displacement of the core and from deformation of a surface, we obtain negative value for secular trend of gravity in - (2.14±0.28) ?Gal/yr, that within the limits of errors it will be coordinated with observable value - (2.5±0.9) ?Gal/yr. Similar results we have obtained for 7 another's gravimetric stations. All results are summarized in the table 1. Here we have used known data about observable secular trends of gravity and GPS heights at considered here stations of the following authors: Ny-Alesund (Sato et al., 2006); Churchill (Larson et al., 2000); Medicine (Zerbini et al., 2001); Syowa (Fukuda et.al., 2007); Strastburg (Almavict et. al., 2004); Membach (Francis et al., 2004); Wuhan (Xu et al., 2008); Metsahovi (Gitlein et. al., 2009). Table 1. Theoretical and observable values of secular variations of a gravity. Stations Core attractionSurface deformation Theory Observations Ny-Alesund+1.60 ?Gal/yr -(3.77±0.09) ?Gal/yr -(2.17±0.03) ?Gal/yr -(2.5±0.9) ?Gal/yr Churchill +1.11 ?Gal/yr -(3.38±0.28) ?Gal/yr -(2.22±0.28) ?Gal/yr -(2.13±0.23) ?Gal/yr Medicina +1.13 ?Gal/yr +(1.07±0.20) ?Gal/yr+(2.20±0.20) ?Gal/yr+(1.90±0.20) ?Gal/yr Syowa -1.44 ?Gal/yr +(0.63±0.08) ?Gal/yr-(0.81±0.08) ?Gal/yr -0.56 ?Gal/yr Strastburg +1.18 ?Gal/yr +(0.71±0.02) ?Gal/yr+(1.89±0.02) ?Gal/yr+(1.90±0.20) ?Gal/yr Membach +1.21 ?Gal/yr -(1.98±0.16) ?Gal/yr -(0.77±0.16) ?Gal/yr -(0.6±0.1) ?Gal/yr Wuhan +1.34 ?Gal/yr -(0.17±0.05) ?Gal/yr +(1.17±0.05) ?Gal/yr+(1.39±0.02) ?Gal/yr Metsahovi +1.47 ?Gal/yr -(2.82±0.06) ?Gal/yr +(1.35±0.06) ?Gal/yr-(0.88±0.52) ?Gal/yr

PET quantification of 5-HT2A receptors in the human brain: a constant infusion paradigm with [18F]altanserin.

PubMed

van Dyck, C H; Tan, P Z; Baldwin, R M; Amici, L A; Garg, P K; Ng, C K; Soufer, R; Charney, D S; Innis, R B

2000-02-01

[18F]altanserin has been used to label serotonin 5-HT2A receptors, which are believed to be important in the pathophysiology of schizophrenia and depression. The purpose of this study was to test the feasibility of a constant infusion paradigm for equilibrium modeling of [18F]altanserin with PET. Kinetic modeling with [18F]altanserin may be hampered by the presence of lipophilic radiometabolites observed in plasma after intravenous administration. Eight healthy volunteers were injected with [18F]altanserin as a bolus (208+/-9 MBq [5.62+/-0.25 mCi]) plus constant infusion (65+/-3 MBq/h [1.76+/-0.08 mCi/h]) ranging from 555 to 626 min (615+/-24 min) after injection. PET acquisitions (10-20 min) and venous blood sampling were performed every 30-60 min throughout the infusion period. Linear regression analysis revealed that time-activity curves for both brain activity and plasma [18F]altanserin and metabolite concentrations stabilized after about 6 h. This permitted equilibrium modeling and estimation of V3' (ratio of specific uptake [cortical-cerebellar] to total plasma parent concentration after 6 h). Values of V3' ranged from 1.57+/-0.38 for anterior cingulate cortex to 1.02+/-0.39 for frontal cortex. The binding potential V3 (ratio of specific uptake to free plasma parent concentration after 6 h, using group mean f1) was also calculated and ranged from 169+/-41 for anterior cingulate cortex to 110+/-42 for frontal cortex. From 6 h onward, the rate of change for V3' and V3 was only 1.11+/-1.69 %/h. These results demonstrate the feasibility of equilibrium imaging with [18F]altanserin over more than 5 radioactive half-lives and suggest a method to overcome difficulties associated with lipophilic radiolabeled metabolites. The stability in V3 and V3' once equilibrium is achieved suggests that a single PET acquisition obtained at 6 h may provide a reasonable measure of 5-HT2A receptor density.

Age of the moon: An isotopic study of uranium-thorium-lead systematics of lunar samples

USGS Publications Warehouse

Tatsumoto, M.; Rosholt, J.N.

1970-01-01

Concentrations of U, Th, and Pb in Apollo 11 samples studied are low (U. 0.16 to 0.87; Th, 0.53 to 3.4; Pb, 0.29 to 1.7, in ppm) but the extremely radiogenic lead in samples allows radiometric dating. The fine dust and the breccia have a concordant age of 4.66 billion years on the basis of 207Pb/206Pb, 206Pb/238U, 207Pb/235U, and 208Pb/232Th ratios. This age is comparable with the age of meteorites and with the age generally accepted for the earth. Six crystalline and vesicular samples are distinctly younger than the dust and breccia. The 238U/235U ratio is the same as that in earth rocks, and 234U is in radioactive equilibrium with parent 238U.

Half-lives of 214Pb and 214Bi.

PubMed

Martz, D E; Langner, G H; Johnson, P R

1991-10-01

New measurements on chemically separated samples of 214Bi have yielded a mean half-life value of 19.71 +/- 0.02 min, where the error quoted is twice the standard deviation of the mean based on 23 decay runs. This result provides strong support for the historic 19.72 +/- 0.04 min half-life value and essentially excludes the 19.9-min value, both reported in previous studies. New measurements of the decay rate of 222Rn progeny activity initially in radioactive equilibrium have yielded a value of 26.89 +/- 0.03 min for the half-life of 214Pb, where the error quoted is twice the standard deviation of the mean based on 12 decay runs. This value is 0.1 min longer than the currently accepted 214Pb half-value of 26.8 min.

Sorption reaction mechanism of some hazardous radionuclides from mixed waste by impregnated crown ether onto polymeric resin.

PubMed

Shehata, F A; Attallah, M F; Borai, E H; Hilal, M A; Abo-Aly, M M

2010-02-01

A novel impregnated polymeric resin was practically tested as adsorbent material for removal of some hazardous radionuclides from radioactive liquid waste. The applicability for the treatment of low-level liquid radioactive waste was investigated. The material was prepared by loading 4,4'(5')di-t-butylbenzo 18 crown 6 (DtBB18C6) onto poly(acrylamide-acrylic acid-acrylonitril)-N, N'-methylenediacrylamide (P(AM-AA-AN)-DAM). The removal of (134)Cs, (60)Co, (65)Zn , and ((152+154))Eu onto P(AM-AA-AN)-DAM/DtBB18C6 was investigated using a batch equilibrium technique with respect to the pH, contact time, and temperature. Kinetic models are used to determine the rate of sorption and to investigate the mechanism of sorption process. Five kinetics models, pseudo-first-order, pseudo-second-order, intra-particle diffusion, homogeneous particle diffusion (HPDM), and Elovich models, were used to investigate the sorption process. The obtained results of kinetic models predicted that, pseudo-second-order is applicable; the sorption is controlled by particle diffusion mechanism and the process is chemisorption. The obtained values of thermodynamics parameters, DeltaH degrees , DeltaS degrees , and DeltaG degrees indicated that the endothermic nature, increased randomness at the solid/solution interface and the spontaneous nature of the sorption processes. Copyright (c) 2009 Elsevier Ltd. All rights reserved.