WorldWideScience

Sample records for ray diurnal variation

  1. Solar tri-diurnal variation of cosmic rays in a wide range of rigidity

    Science.gov (United States)

    Mori, S.; Ueno, H.; Fujii, Z.; Morishita, I.; Nagashima, K.

    1985-01-01

    Solar tri-diurnal variations of cosmic rays have been analyzed in a wide range of rigidity, using data from neutron monitors, and the surface and underground muon telescopes for the period 1978-1983. The rigidity spectrum of the anisotropy in space is assumed to be of power-exponential type as (P/gamma P sub o) to the gamma exp (gamma-P/P sub o). By means of the best-fit method between the observed and the expected variations, it is obtained that the spectrum has a peak at P (=gamma P sub o) approx = 90 GV, where gamma=approx 3.0 and P sub o approx. 30 GV. The phase in space of the tri-diurnal variation is also obtained as 7.0 hr (15 hr and 23 hr LT), which is quite different from that of approx. 1 hr. arising from the axisymmetric distribution of cosmic rays with respect to the IMF.

  2. Diurnal variations of Titan

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Mueller-Wodarg, I. C. F.; Kasprzak, W. T.; Waite, J. H.

    2009-04-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1,000 and 1,400 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from 8 close encounters of the Cassini spacecraft with Titan. Though there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ~700 cm-3 below ~1,300 km. Such a plateau is associated with the combination of distinct diurnal variations of light and heavy ions. Light ions (e.g. CH5+, HCNH+, C2H5+) show strong diurnal variation, with clear bite-outs in their nightside distributions. In contrast, heavy ions (e.g. c-C3H3+, C2H3CNH+, C6H7+) present modest diurnal variation, with significant densities observed on the nightside. We propose that the distinctions between light and heavy ions are associated with their different chemical loss pathways, with the former primarily through "fast" ion-neutral chemistry and the latter through "slow" electron dissociative recombination. The INMS data suggest day-to-night transport as an important source of ions on Titan's nightside, to be distinguished from the conventional scenario of auroral ionization by magnetospheric particles as the only ionizing source on the nightside. This is supported by the strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes. We construct a time-dependent ion chemistry model to investigate the effects of day-to-night transport on the ionospheric structures of Titan. The predicted diurnal variation has similar general characteristics to those observed, with some apparent discrepancies which could be reconciled by imposing fast horizontal thermal winds in Titan's upper atmosphere.

  3. Local Times of Galactic Cosmic Ray Intensity Maximum and Minimum in the Diurnal Variation

    Directory of Open Access Journals (Sweden)

    Su Yeon Oh

    2006-06-01

    Full Text Available The Diurnal variation of galactic cosmic ray (GCR flux intensity observed by the ground Neutron Monitor (NM shows a sinusoidal pattern with the amplitude of 1sim 2 % of daily mean. We carried out a statistical study on tendencies of the local times of GCR intensity daily maximum and minimum. To test the influences of the solar activity and the location (cut-off rigidity on the distribution in the local times of maximum and minimum GCR intensity, we have examined the data of 1996 (solar minimum and 2000 (solar maximum at the low-latitude Haleakala (latitude: 20.72 N, cut-off rigidity: 12.91 GeV and the high-latitude Oulu (latitude: 65.05 N, cut-off rigidity: 0.81 GeV NM stations. The most frequent local times of the GCR intensity daily maximum and minimum come later about 2sim3 hours in the solar activity maximum year 2000 than in the solar activity minimum year 1996. Oulu NM station whose cut-off rigidity is smaller has the most frequent local times of the GCR intensity maximum and minimum later by 2sim3 hours from those of Haleakala station. This feature is more evident at the solar maximum. The phase of the daily variation in GCR is dependent upon the interplanetary magnetic field varying with the solar activity and the cut-off rigidity varying with the geographic latitude.

  4. Diurnal variation of cosmic ray intensity I. Two approaches to the study

    International Nuclear Information System (INIS)

    Sari, J.W.; Venkatesan, D.; Lanzerotti, L.J.; Maclennan, C.G.

    1978-01-01

    The investigation has been carried out over the past two decades by either of two approaches: the traditional Fourier series method and the more recently introduced power spectral method. A comparison of the two approaches is essential to the proper understanding of the results derived from them. The present study, for the first time, adopts both approaches for investigating the data from the Sulfur Mountain super neutron monitor for the period of mid-December 1965 to April 1966 (extending over five solar rotations), when interplanetary magnetic field data from Pioneer 6 were also available. Problems relating to the analyses of both data sets on a day-to-day basis and on a statistical basis over a number of days are discussed. The power spectral analysis method cannot provide information on the phase of the diurnal variation or information on the diurnal amplitude on a day-to-day basis. This method provides excellent estimates of the diurnal anisotropy amplitude provides a measure of the ambient anisotropy amplitude. The Fourier series method can yield reliable measures of the amplitude and phase on a day-to-day basis, provided the time series is reasonably stationary. This method cannot estimate the ambient anisotropy amplitude which, for small amplitudes, contributes to large uncertainties in the Fourier coefficients. We find that there is a general agreement between the observed diurnal variation and that predicted theoretically. However, for most of the periods examined the ratio of the perpendicular diffusion coefficient to the parallel diffusion coefficient is rather small (K 1 /K < or approx. =0.1). As such the diurnal variation amplitude is generally most sensitive to the interplanetary field direction and the solar wind velocity and not to the calculated values of the diffusion coefficients. Further tests of the theory are discussed

  5. Decadal trends in the diurnal variation of galactic cosmic rays observed using neutron monitor data

    Energy Technology Data Exchange (ETDEWEB)

    Thomas, Simon [Reading Univ. (United Kingdom). Dept. of Meteorology; Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.; Owens, Mathew; Lockwood, Mike [Reading Univ. (United Kingdom). Dept. of Meteorology; Owen, Chris [Univ. College London, Dorking (United Kingdom). Mullard Space Science Lab.

    2017-10-01

    The diurnal variation (DV) in galactic cosmic ray (GCR) flux is a widely observed phenomenon in neutron monitor data. The background variation considered primarily in this study is due to the balance between the convection of energetic particles away from the Sun and the inward diffusion of energetic particles along magnetic field lines. However, there are also times of enhanced DV following geomagnetic disturbances caused by coronal mass ejections or corotating interaction regions. In this study we investigate changes in the DV over four solar cycles using ground-based neutron monitors at different magnetic latitudes and longitudes at Earth. We divide all of the hourly neutron monitor data into magnetic polarity cycles to investigate cycle-to-cycle variations in the phase and amplitude of the DV. The results show, in general, a similarity between each of the A<0 cycles and A>0 cycles, but with a phase change between the two. To investigate this further, we split the neutron monitor data by solar magnetic polarity between times when the dominant polarity was either directed outward (positive) or inward (negative) at the northern solar pole. We find that the maxima and minima of the DV changes by, typically, 1-2 h between the two polarity states for all non-polar neutron monitors. This difference between cycles becomes even larger in amplitude and phase with the removal of periods with enhanced DV caused by solar wind transients. The time difference between polarity cycles is found to vary in a 22-year cycle for both the maximum and minimum times of the DV. The times of the maximum and minimum in the DV do not always vary in the same manner between A>0 and A<0 polarity cycles, suggesting a slight change in the anisotropy vector of GCRs arriving at Earth between polarity cycles. Polar neutron monitors show differences in phase between polarity cycles which have asymptotic directions at mid-to-high latitudes. All neutron monitors show changes in the amplitude of the

  6. Diurnal variations of Titan's ionosphere

    Science.gov (United States)

    Cui, J.; Galand, M.; Yelle, R. V.; Vuitton, V.; Wahlund, J.-E.; Lavvas, P. P.; Müller-Wodarg, I. C. F.; Cravens, T. E.; Kasprzak, W. T.; Waite, J. H.

    2009-06-01

    We present our analysis of the diurnal variations of Titan's ionosphere (between 1000 and 1300 km) based on a sample of Ion Neutral Mass Spectrometer (INMS) measurements in the Open Source Ion (OSI) mode obtained from eight close encounters of the Cassini spacecraft with Titan. Although there is an overall ion depletion well beyond the terminator, the ion content on Titan's nightside is still appreciable, with a density plateau of ˜700 cm-3 below ˜1300 km. Such a plateau is a combined result of significant depletion of light ions and modest depletion of heavy ones on Titan's nightside. We propose that the distinctions between the diurnal variations of light and heavy ions are associated with their different chemical loss pathways, with the former primarily through “fast” ion-neutral chemistry and the latter through “slow” electron dissociative recombination. The strong correlation between the observed night-to-day ion density ratios and the associated ion lifetimes suggests a scenario in which the ions created on Titan's dayside may survive well to the nightside. The observed asymmetry between the dawn and dusk ion density profiles also supports such an interpretation. We construct a time-dependent ion chemistry model to investigate the effect of ion survival associated with solid body rotation alone as well as superrotating horizontal winds. For long-lived ions, the predicted diurnal variations have similar general characteristics to those observed. However, for short-lived ions, the model densities on the nightside are significantly lower than the observed values. This implies that electron precipitation from Saturn's magnetosphere may be an additional and important contributor to the densities of the short-lived ions observed on Titan's nightside.

  7. Diurnal variation of zooplankton off Versova (Bombay)

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Nair, V.R.; Desai, B.N.

    Physicochemical parameters and diurnal variaion of zooplankton were studied off Versova on 17/18 February 1981. Salinity and dissolved oxygen showed limited variation during the period of study. Nutrient values followed the tidal rhythm and high...

  8. Diurnal variations of tritium uptake by plants

    International Nuclear Information System (INIS)

    Hettinger, M.; Diabate, S.; Strack, S.

    1991-02-01

    The influence of the diurnal cycle is important for the behaviour of environmental tritium in the vegetation. A mathematical model has been used to calculate the deposition of tritium in plants as a function of diurnal variations of climatic parameters. The necessary physiological parameters (relationship of net photosynthesis and growth) were derived from growth experiments for tomatoes and maize. In chamber experiments, tomato and maize plants were exposed to tritium with natural diurnal variations of the climatic conditions. Within the range of standard deviations the measured concentrations of tritium in tissue free water of tomatoes correspond well to the estimated values. Furthermore, the incorporation into non-exchangeable organically bound tritium (OBT nx) can be sufficiently modelled and explained. There are deviations from the estimated concentrations in some parts of maize leaves. (orig.) [de

  9. Heliospheric Modulation of Galactic Cosmic Rays; Diurnal Variability Abstract Details

    Science.gov (United States)

    Kalu, D. F.; Okpala, K. C.

    2017-12-01

    We have studied the variability of Cosmic rays flux during solar quiet days at mid and high latitudes in the Northern Hemisphere. By using the five (5) quietest days for each month and the five disturbed days for each month, the monthly mean diurnal variation of cosmic ray anisotropy have been derived for the period 1999-2015, which covers part of cycles 23, and cycle 24. This study seeks to understand the heliospheric contribution to the variation of these Cosmic rays on quietest days, three stations (Inuvik, Moscow, Rome) Neutron Monitors were employed. This study seeks to understand the important features of the high latitude and mid latitude diurnal wave, and how solar and geomagnetic activity may be influencing the wave characteristics. Cosmic ray wave characteristics were obtained by discrete Fourier transform (DFT). The mean, diurnal amplitude, phase and dispersion for each month's diurnal wave were calculated and profiled. There was clear indication that the terrestrial effect on the variability of the monthly mean was more associated with geomagnetic activity rather than rigidity of the cosmic rays. Correlation of the time series of these wave characteristic with solar and geomagnetic activity index showed better association with solar activity.

  10. Pulse pressure and diurnal blood pressure variation

    DEFF Research Database (Denmark)

    Knudsen, Søren Tang; Poulsen, Per Løgstrup; Hansen, Klavs Würgler

    2002-01-01

    retinopathy, nephropathy, macrovascular disease, PP, and diurnal BP variation in a group of type 2 diabetic patients. METHODS: In 80 type 2 diabetic patients we performed 24-h ambulatory BP (AMBP) and fundus photographs. Urinary albumin excretion was evaluated by urinary albumin/creatinine ratio. Presence...... or absence of macrovascular disease was assessed by an independent physician. RESULTS: Forty-nine patients had no detectable retinal changes (grade 1), 13 had grade 2 retinopathy, and 18 had more advanced retinopathy (grades 3-6). Compared to patients without retinopathy (grade 1), patients with grades 2......BACKGROUND: In nondiabetic subjects pulse pressure (PP) is an independent predictor of cardiovascular disease and microalbuminuria. Reduced circadian blood pressure (BP) variation is a potential risk factor for the development of diabetic complications. We investigated the association between...

  11. Diurnal Variation and Spatial Distribution Effects on Sulfur Speciation in Aerosol Samples as Assessed by X-Ray Absorption Near-Edge Structure (XANES

    Directory of Open Access Journals (Sweden)

    Siwatt Pongpiachan

    2012-01-01

    Full Text Available This paper focuses on providing new results relating to the impacts of Diurnal variation, Vertical distribution, and Emission source on sulfur K-edge XANES spectrum of aerosol samples. All aerosol samples used in the diurnal variation experiment were preserved using anoxic preservation stainless cylinders (APSCs and pressure-controlled glove boxes (PCGBs, which were specially designed to prevent oxidation of the sulfur states in PM10. Further investigation of sulfur K-edge XANES spectra revealed that PM10 samples were dominated by S(VI, even when preserved in anoxic conditions. The “Emission source effect” on the sulfur oxidation state of PM10 was examined by comparing sulfur K-edge XANES spectra collected from various emission sources in southern Thailand, while “Vertical distribution effects” on the sulfur oxidation state of PM10 were made with samples collected from three different altitudes from rooftops of the highest buildings in three major cities in Thailand. The analytical results have demonstrated that neither “Emission source” nor “Vertical distribution” appreciably contribute to the characteristic fingerprint of sulfur K-edge XANES spectrum in PM10.

  12. Dopamine transporters govern diurnal variation in extracellular dopamine tone

    OpenAIRE

    Ferris, Mark J.; España, Rodrigo A.; Locke, Jason L.; Konstantopoulos, Joanne K.; Rose, Jamie H.; Chen, Rong; Jones, Sara R.

    2014-01-01

    The mechanism for diurnal (i.e., light/dark) oscillations in extracellular dopamine tone in mesolimbic and nigrostriatal systems is unknown. This is because, unlike other neurotransmitter systems, variation in dopamine tone does not correlate with variation in dopamine cell firing. The current research pinpoints the dopamine transporter as a critical governor of diurnal variation in both extracellular dopamine tone and the intracellular availability of releasable dopamine. These data describe...

  13. Diurnal variation of tropospheric temperature at a tropical station

    Directory of Open Access Journals (Sweden)

    K. Revathy

    2001-08-01

    Full Text Available The vertical velocity in the troposphere-lower stratosphere region measured using MST radar has been utilized to evaluate the temperature profile in the region. The diurnal variation of the tropospheric temperature on one day in August 1998 at the tropical station Gadanki (13.5° N, 79.2° E has been studied using the MST radar technique. The diurnal variation of the temperature revealed a prominent diurnal variation with the peak in the afternoon hours increasingly delayed in altitude. The tropopause temperature and altitude exhibited a clear diurnal cycle.Key words. Atmospheric composition and structure (pressure, density and temperature; troposphere - composition and chemistry; instruments and technique

  14. Atmospheric diurnal variations observed with GPS radio occultation soundings

    Directory of Open Access Journals (Sweden)

    F. Xie

    2010-07-01

    Full Text Available The diurnal variation, driven by solar forcing, is a fundamental mode in the Earth's weather and climate system. Radio occultation (RO measurements from the six COSMIC satellites (Constellation Observing System for Meteorology, Ionosphere and Climate provide nearly uniform global coverage with high vertical resolution, all-weather and diurnal sampling capability. This paper analyzes the diurnal variations of temperature and refractivity from three-year (2007–2009 COSMIC RO measurements in the troposphere and stratosphere between 30° S and 30° N. The RO observations reveal both propagating and trapped vertical structures of diurnal variations, including transition regions near the tropopause where data with high vertical resolution are critical. In the tropics the diurnal amplitude in refractivity shows the minimum around 14 km and increases to a local maximum around 32 km in the stratosphere. The upward propagating component of the migrating diurnal tides in the tropics is clearly captured by the GPS RO measurements, which show a downward progression in phase from stratopause to the upper troposphere with a vertical wavelength of about 25 km. At ~32 km the seasonal variation of the tidal amplitude maximizes at the opposite side of the equator relative to the solar forcing. The vertical structure of tidal amplitude shows strong seasonal variations and becomes asymmetric along the equator and tilted toward the summer hemisphere in the solstice months. Such asymmetry becomes less prominent in equinox months.

  15. Latitudinal and longitudinal dependence of the cosmic ray diurnal anisotropy during 2001-2014

    International Nuclear Information System (INIS)

    Tezari, Anastasia; Mavromichalaki, Helen; Katsinis, Dimitrios; Kanellakopoulos, Anastasios; Kolovi, Sofia; Plainaki, Christina; National and Kapodistrian Univ. of Athens; Andriopoulou, Maria

    2016-01-01

    The diurnal anisotropy of cosmic ray intensity for the time period 2001 to 2014 is studied, covering the maximum and the descending phase of solar cycle 23, the minimum between solar cycles 23 and 24, and the ascending phase and maximum of solar cycle 24. Cosmic ray intensity data from 11 neutron monitor stations located at different places around the Northern Hemisphere obtained from the high-resolution Neutron Monitor Database (NMDB) were used. Special software was developed for the calculations of the amplitude and the phase of the diurnal anisotropy vectors on annual and monthly basis using Fourier analysis and for the creation of the harmonic dial diagrams. The geomagnetic bending for each station was taken into account in our calculations determined from the asymptotic cones of each station via the Tsyganenko96 (Tsyganenko and Stern, 1996) magnetospheric model. From our analysis, it was resulted that there is a different behavior of the diurnal anisotropy vectors during the different phases of the solar cycles depending on the solar magnetic field polarity. The latitudinal and longitudinal distribution of the cosmic ray diurnal anisotropy was also examined by grouping the stations according to their geographic coordinates, and it was shown that diurnal variation is modulated not only by the latitude but also by the longitude of the stations. The diurnal anisotropy during strong events of solar and/or cosmic ray activity is discussed.

  16. Latitudinal and longitudinal dependence of the cosmic ray diurnal anisotropy during 2001-2014

    Energy Technology Data Exchange (ETDEWEB)

    Tezari, Anastasia; Mavromichalaki, Helen; Katsinis, Dimitrios; Kanellakopoulos, Anastasios; Kolovi, Sofia [National and Kapodistrian Univ. of Athens (Greece). Nuclear and Particle Physics Dept.; Plainaki, Christina [INAF-IAPS, Rome (Italy); National and Kapodistrian Univ. of Athens (Greece). Nuclear and Particle Physics Dept.; Andriopoulou, Maria [Austrian Academy of Sciences, Graz (Austria). Space Research Inst.

    2016-07-01

    The diurnal anisotropy of cosmic ray intensity for the time period 2001 to 2014 is studied, covering the maximum and the descending phase of solar cycle 23, the minimum between solar cycles 23 and 24, and the ascending phase and maximum of solar cycle 24. Cosmic ray intensity data from 11 neutron monitor stations located at different places around the Northern Hemisphere obtained from the high-resolution Neutron Monitor Database (NMDB) were used. Special software was developed for the calculations of the amplitude and the phase of the diurnal anisotropy vectors on annual and monthly basis using Fourier analysis and for the creation of the harmonic dial diagrams. The geomagnetic bending for each station was taken into account in our calculations determined from the asymptotic cones of each station via the Tsyganenko96 (Tsyganenko and Stern, 1996) magnetospheric model. From our analysis, it was resulted that there is a different behavior of the diurnal anisotropy vectors during the different phases of the solar cycles depending on the solar magnetic field polarity. The latitudinal and longitudinal distribution of the cosmic ray diurnal anisotropy was also examined by grouping the stations according to their geographic coordinates, and it was shown that diurnal variation is modulated not only by the latitude but also by the longitude of the stations. The diurnal anisotropy during strong events of solar and/or cosmic ray activity is discussed.

  17. A time series approach to the correction for atmosphere effects and the significance of a semi-diurnal variation in corrected intensities of secondary cosmic ray neutrons and mesons (NM64 and MT64)

    International Nuclear Information System (INIS)

    Huijsmans, D.P.

    1982-01-01

    The aim of this research was to distinguish as accurately as possible between two mechanisms behind a half-daily variation in detected numbers of neutrons and mesons in the secondary cosmic ray particles at sea level. These two mechanisms are due to air pressure variations at sea level and affect the number of primary particles with a certain arrival direction. The distribution among arrival directions in the ecliptic plane varies if a gradient exists in the guiding centre density of primaries in directions perpendicular to the neutral sheet. Chapter 2 is devoted to the calculation of a physically and statistically justifiable determination of the barometric coefficient for neutron measurements and air pressures. Chapter 3 deals with the estimation of atmospheric correction coefficients for the elimination of the influence of changing atmospheric conditions on the number of detected mesons. For mesons the variation of total mass, and also the variations in mass-distribution along the trajectory of the mesons are important. After correction for atmospheric variations using the resulting atmospheric correction coefficients from chapter 2 and 3, the influence of the structure of the interplanetary magnetic field near the earth is examined in chapter 4. 0inally, in chapter 5, a power spectral analysis of variations in corrected intensities of neutrons and mesons is carried out. Such an analysis distinguishes the variance of a time series into contributions within small frequency intervals. From the power spectra of variations on a yearly basis, a statistically fundamented judgement can be given as to the significance of the semi-diurnal variation during the different phases of the solar magnetic activity cycle. (Auth.)

  18. An unusual kind of diurnal streamflow variation

    Directory of Open Access Journals (Sweden)

    Cuevas Jaime G.

    2018-03-01

    Full Text Available During hydrological research in a Chilean swamp forest, we noted a pattern of higher streamflows close to midday and lower ones close to midnight, the opposite of an evapotranspiration (Et-driven cycle. We analyzed this diurnal streamflow signal (DSS, which appeared mid-spring (in the growing season. The end of this DSS coincided with a sustained rain event in autumn, which deeply affected stream and meteorological variables. A survey along the stream revealed that the DSS maximum and minimum values appeared 6 and 4 hours earlier, respectively, at headwaters located in the mountain forests/ plantations than at the control point in the swamp forest. Et in the swamp forest was higher in the morning and in the late afternoon, but this process could not influence the groundwater stage. Trees in the mountain headwaters reached their maximum Ets in the early morning and/or close to midday. Our results suggest that the DSS is a wave that moves from forests high in the mountains towards lowland areas, where Et is decoupled from the DSS. This signal delay seems to convert the link between streamflow and Et in an apparent, but spurious positive relationship. It also highlights the role of landscape heterogeneity in shaping hydrological processes.

  19. Diurnal variations of serum erythropoietin at sea level and altitude

    DEFF Research Database (Denmark)

    Klausen, T; Poulsen, T D; Fogh-Andersen, N

    1996-01-01

    in 2, 3 diphosphoglycerate. After 64 h at altitude, six of the nine subjects had down-regulated their serum-EPO concentrations so that median values were three times above those at sea level. These six subjects had significant diurnal variations of serum-EPO concentration at sea level; the nadir...

  20. Solar flare location effect on the spectral characteristics of the diurnal anisotropy of cosmic ray intensity

    Energy Technology Data Exchange (ETDEWEB)

    Yadava, R S; Kumar, S; Naqvi, T N [Aligarh Muslim Univ. (India)

    1977-01-01

    The spectral parameters of the diurnal anisotropy of cosmic ray intensity are studied separately for days where the solar flares have occurred on the western limb as well as on the eastern limb of the solar disc for both nucleonic as well as mesonic components of the cosmic rays. It is observed that the diurnal amplitude of the cosmic ray intensity in space is larger for days where solar flares have occurred on the western limb of the solar disc as compared to the days where solar flares have occurred on the eartern limb of the solar disc. This is true in both nucleonic as well as mesonic components of the cosmic ray intensity. The average value of the direction in space of diurnal anisotropy in local asymptotic time for various stations is almost same and is observed at around the same hours for flares which occur on the western as well as eastern limb of the solar disc. When these results are compared with the direction of the diurnal anisotropy in space on quiet days, it is found that the direction of the diurnal anisotropy on days where solar flares have occurred on the western limb as well as eastern limb of the solar disc is earlier in comparison to quiet days. This phase shift towards earlier hours is about three hours for nucleonic as well as mesonic components of the cosmic rays intensity. The variation of the rigidity exponent observed on different types of days for the nucleonic component has also been discussed.

  1. Diurnal variations of indoor radon progeny for Bangalore metropolitan, India

    International Nuclear Information System (INIS)

    Nagesh, V.; Sathish, L.A.; Nagaraja, K.; Sundareshan, S.

    2010-01-01

    Radon progenies are identified as major causes of the lung cancer if the activity is above its normal. It has not been clear whether radon poses a similar risk of causing lung cancer in humans exposed at generally lower levels found in homes, but a number of indoor radon survey have been carried out in recent years around the world. In view of this an attempt has been made for the measurement of diurnal variation of indoor radon levels for the environment of Bangalore metropolitan, India. The Radon progeny concentrations in terms of working level were measured using Kusnetz's method. The patterns of daily and annual changes in indoor Radon concentration have been observed in a general way for many years. However, understanding of the physical basis for these changes had to await the development of continuous monitors and a more complete knowledge of transport processes in the atmosphere. Over a continent, heating of the ground surface by the Sun during the day and cooling by radiation during the night causes a marked diurnal change in temperature near the surface. As a result cool air near the ground will accumulate radon isotopes from surface flux during the night; while during the day the warm air will be transported upward carrying radon with it. Many buildings show diurnal radon variations. Concentrations are relatively higher during night than daytime. This is influenced by the outdoor-indoor temperature contrast. This effect can be enhanced in buildings with strong diurnal use patterns. Buildings that have high average radon concentrations, but are only occupied for part of the day, may need to be measured during occupied periods to determine if there is significant diurnal radon variation. The results are discussed in detail. (author)

  2. Generation of diurnal variation for influent data for dynamic simulation.

    Science.gov (United States)

    Langergraber, G; Alex, J; Weissenbacher, N; Woerner, D; Ahnert, M; Frehmann, T; Halft, N; Hobus, I; Plattes, M; Spering, V; Winkler, S

    2008-01-01

    When using dynamic simulation for fine tuning of the design of activated sludge (AS) plants diurnal variations of influent data are required. For this application usually only data from the design process and no measured data are available. In this paper a simple method to generate diurnal variations of wastewater flow and concentrations is described. The aim is to generate realistic influent data in terms of flow, concentrations and TKN/COD ratios and not to predict the influent of the AS plant in detail. The work has been prepared within the framework of HSG-Sim (Hochschulgruppe Simulation, http://www.hsgsim.org), a group of researchers from Germany, Austria, Luxembourg, Poland, the Netherlands and Switzerland. (c) IWA Publishing 2008.

  3. Prenatal exposure to diurnal temperature variation and early childhood pneumonia.

    Science.gov (United States)

    Zeng, Ji; Lu, Chan; Deng, Qihong

    2017-04-01

    Childhood pneumonia is one of the leading single causes of mortality and morbidity in children worldwide, but its etiology still remains unclear. We investigate the association between childhood pneumonia and exposure to diurnal temperature variation (DTV) in different timing windows. We conducted a prospective cohort study of 2,598 children aged 3-6 years in Changsha, China. The lifetime prevalence of pneumonia was assessed by a questionnaire administered by the parents. Individual exposure to DTV during both prenatal and postnatal periods was estimated. Logic regression models was used to examine the association between childhood pneumonia and DTV exposure in terms of odds ratios (OR) and 95% confidence interval (CI). Lifetime prevalence of childhood pneumonia in preschool children in Changsha was high up to 38.6%. We found that childhood pneumonia was significantly associated with prenatal DTV exposure, with adjusted OR (95%CI) =1.19 (1.02-1.38), particularly during the second trimester. However, childhood pneumonia not associated with postnatal DTV exposure. Sensitivity analysis indicated that boys are more susceptible to the pneumonia risk of diurnal temperature variation than girls. We further observed that the prevalence of childhood pneumonia was decreased in recent years as DTV shrinked. Early childhood pneumonia was associated with prenatal exposure to the diurnal temperature variation (DTV) during pregnancy, particularly in the second trimester, which suggests fetal origin of childhood pneumonia. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Diurnal Variation of Radon Concentration in the Postojna Cave

    International Nuclear Information System (INIS)

    Gregoric, A.; Vaupotic, J.

    2011-01-01

    Postojna Cave, with 20 km of galleries, is the longest known cave system and also the largest of about 20 show caves in Slovenia and one of the most visited show caves in the world. It is well known that high concentrations of radon are common in karstic caves, although quantities of uranium (238U) in limestone are rather low. The reason for this is low natural ventilation of the underground cavities. Tectonic faults constitute an additional source of radon. Variations of radon concentration in cave air arise from a balance of the emission from cave surfaces and drip waters, decay in cave air, and exchange with the outside atmosphere. Because of its elevated radon concentrations, Postojna Cave has been under permanent radon survey since 1995. The influence of meteorological conditions on the radon levels and their temporal variations depends mostly on the shape of the cave, and the number and directions of cracks, corridors and fissures connecting the cave rooms with the outside atmosphere. The driving force for air movement in horizontal caves, and thus the inflow of fresh air and release of the cave air to the atmosphere, is the temperature difference between the cave air and outdoors, which causes seasonal pattern of radon concentration in the cave with high levels in summer and low in winter. However, on a daily scale different behaviour of radon can be observed at different locations in the cave. In this paper diurnal variation of radon concentration at two locations is presented and discussed. Postojna Cave is a horizontal cave with a stable yearly temperature around 10 degrees of @C. Continuous measurements of radon concentration were carried out from 2005 to 2010 at two locations along the guided tourist trail. Radon concentration was measured with Radim 5 WP monitors (SMM Company, Prague, Czech Republic) with sampling frequency once an hour. The evaluation of five-year radon monitoring at two sites in the Postojna Cave reveals significant diurnal and

  5. Spectral and diurnal variations in clear sky planetary albedo

    Science.gov (United States)

    Briegleb, B.; Ramanathan, V.

    1982-01-01

    Spectral and diurnal variations in the clear sky planetary albedo of the earth are calculated using a radiative transfer model to obtain January and July values for a 5 deg x 5 deg global grid. The model employs observed climatological values of temperatures, humidities, snow and sea-ice cover. The diurnal cycle of clear sky albedo is calculated in the following intervals: 0.2-0.5, 0.5-0.7, and 0.7-4 microns. Observed ozone distribution is specified as a function of latitude and season. The 0.2-0.5 micron spectral albedo is 10-20% higher than the total albedo for all latitudes because of Rayleigh scattering; the 0.5-0.7 micron albedo differs from the total albedo by 1-2% for most latitudes, while the 0.7-4 micron albedo is 5-10% lower than the total because of strong atmospheric absorption. Planetary albedo decreases from morning to local noon, with diurnal variations being particularly strong over water.

  6. Observed diurnal variations in Mars Science Laboratory Dynamic Albedo of Neutrons passive mode data

    Science.gov (United States)

    Tate, C. G.; Moersch, J.; Jun, I.; Mitrofanov, I.; Litvak, M.; Boynton, W. V.; Drake, D.; Fedosov, F.; Golovin, D.; Hardgrove, C.; Harshman, K.; Kozyrev, A. S.; Kuzmin, R.; Lisov, D.; Maclennan, E.; Malakhov, A.; Mischna, M.; Mokrousov, M.; Nikiforov, S.; Sanin, A. B.; Starr, R.; Vostrukhin, A.

    2018-06-01

    The Mars Science Laboratory Dynamic Albedo of Neutrons (DAN) experiment measures the martian neutron leakage flux in order to estimate the amount of water equivalent hydrogen present in the shallow regolith. When DAN is operating in passive mode, it is sensitive to neutrons produced through the interactions of galactic cosmic rays (GCR) with the regolith and atmosphere and neutrons produced by the rover's Multi-Mission Radioisotope Thermoelectric Generator (MMRTG). During the mission, DAN passive mode data were collected over the full diurnal cycle at the locations known as Rocknest (sols 60-100) and John Klein (sols 166-272). A weak, but unexpected, diurnal variation was observed in the neutron count rates reported at these locations. We investigate different hypotheses that could be causing these observed variations. These hypotheses are variations in subsurface temperature, atmospheric pressure, the exchange of water vapor between the atmosphere and regolith, and instrumental effects on the neutron count rates. Our investigation suggests the most likely factors contributing to the observed diurnal variations in DAN passive data are instrumental effects and time-variable preferential shielding of alpha particles, with other environmental effects only having small contributions.

  7. ANALYSIS THE DIURNAL VARIATIONS ON SELECTED PHYSICAL AND PHYSIOLOGICAL PARAMETERS

    Directory of Open Access Journals (Sweden)

    A. MAHABOOBJAN

    2010-12-01

    Full Text Available The purpose of the study was to analyze the diurnal variations on selected physical and physiological parameters such as speed, explosive power, resting heart rate and breath holding time among college students. To achieve the purpose of this study, a total of twenty players (n=20 from Government Arts College, Salem were selected as subjects To study the diurnal variation of the players on selected physiological and performance variables, the data were collected 4 times a day with every four hours in between the times it from 6.00 to 18.00 hours were selected as another categorical variable. One way repeated measures (ANOVA was used to analyze the data. If the obtained F-ratio was significant, Seheffe’s post-hoc test was used to find out the significant difference if anyamong the paired means. The level of significance was fixed at.05 level. It has concluded that both physical and physiological parameters were significantly deferred with reference to change of temperature in a day

  8. Diurnal variations of serum erythropoietin at sea level and altitude

    DEFF Research Database (Denmark)

    Klausen, T; Poulsen, T D; Fogh-Andersen, N

    1996-01-01

    in 2, 3 diphosphoglycerate. After 64 h at altitude, six of the nine subjects had down-regulated their serum-EPO concentrations so that median values were three times above those at sea level. These six subjects had significant diurnal variations of serum-EPO concentration at sea level; the nadir......This study tested the hypothesis that the diurnal variations of serum-erythropoietin concentration (serum-EPO) observed in normoxia also exist in hypoxia. The study also attempted to investigate the regulation of EPO production during sustained hypoxia. Nine subjects were investigated at sea level...... and during 4 days at an altitude of 4350 m. Median sea level serum-EPO concentration was 6 (range 6-13) U.l-1. Serum-EPO concentration increased after 18 and 42 h at altitude, [58 (range 39-240) and 54 (range 36-340) U.l-1, respectively], and then decreased after 64 and 88 h at altitude [34 (range 18...

  9. Monthly and diurnal variations of limnological conditions of two ponds

    Directory of Open Access Journals (Sweden)

    AKM Fazlur Rahaman

    2017-06-01

    Full Text Available A study on monthly and diurnal changes of limnological conditions of two ponds was conducted in the Bangladesh Agricultural University campus, Mymensingh. The research work was performed by studying the limnological parameters such as transparency, temperature, dissolved oxygen, free carbon dioxide, pH, total alkalinity, nitrate-nitrogen, phosphate-phosphorus and plankton. Diurnal variations of physico-chemical factors were studied fortnightly at 6 hrs intervals at 6 a.m., 12 noon, 6 p.m. and 12 midnight. The amounts of transparency, dissolved oxygen and pH were higher during winter months than in summer months in both the ponds. Transparency, water temperature, total alkalinity, NO3-N and PO4-P were higher during summer months than in winter months in both the ponds. But the amount of free carbon dioxide was higher during winter months than in summer months in pond 1 while in pond 2 the amount of free carbon dioxide was higher during summer months than in winter months. Qualitative and quantitative monthly variations of phytoplankton and zooplankton were observed in both the ponds during the study period. The highest amount of dissolved oxygen, pH and total alkalinity were recorded at 6 p.m. and the lowest amounts of those at 6 a.m. in both the ponds. The highest temperature was recorded at 12 noon and the lowest at 12 midnight. But the highest amount of free carbon dioxide was recorded at 6 a.m. and the lowest at 6 p.m. in both the ponds. All the factors showed appreciable diel variations throughout the study period, which indicate that the ponds are productive.

  10. Daily diurnal variation in admissions for ruptured abdominal aortic aneurysms.

    LENUS (Irish Health Repository)

    Killeen, Shane

    2012-02-03

    BACKGROUND: Many vascular events, such as myocardial infarction and cerebrovascular accident, demonstrate a circadian pattern of presentation. Blood pressure is intimately related to these pathologies and is the one physiological variable consistently associated with abdominal aortic aneurysm rupture. It also demonstrates a diurnal variation. The purpose of this study was to determine if rupture of an abdominal aortic aneurysm (RAAA) exhibits a diurnal variation. METHODS: A retrospective cohort-based study was performed to determine the timing of presentation of RAAA to the vascular unit of Cork University Hospital over a 15-year period. Time of admission, symptom onset, and co-morbidities such as hypertension were noted. Fournier\\'s analysis and chi-squared analysis were performed. To ameliorate possible confounding factors, patients admitted with perforated peptic ulcers were examined in the same manner. RESULTS: A total of 148 cases of RAAA were identified, with a male preponderance (71.7% [124] male versus 29.3% [44] female patients) and a mean age of 74.4 +\\/- 7.2 years at presentation. 70.9% (105) were known to have hypertension, 52.2% (77) were current smokers, and 46.8% (69) were being treated for chronic obstructive airway disease (COAD). Time of symptom onset was recorded in 88.5% (131) of patients. There was a marked early morning peak in RAAA admissions, with the highest number of RAAA being admitted between 08.00 and 09.59. A second, smaller peak was observed at 14.00-15.59. These findings were suggestive of diurnal variation. [chi(2) =16.75, p < 0.003]. Some 40% (59) of patients were admitted between 00.00 and 06.00, an incidence significantly higher than for other time periods (06.00-12.00, 12.00-18.00, and 18.00-24.00) [chi(2) = 18.72; df = 3; p < 0.0003]. A significantly higher number of patients admitted between 00.00 and 06.00 were known hypertensives (chi(2) = 7.94; p < 0.05). CONCLUSIONS: The findings of this study suggest a distinct

  11. Diurnal changes of earthquake activity and geomagnetic Sq-variations

    Directory of Open Access Journals (Sweden)

    G. Duma

    2003-01-01

    Full Text Available Statistic analyses demonstrate that the probability of earthquake occurrence in many earthquake regions strongly depends on the time of day, that is on Local Time (e.g. Conrad, 1909, 1932; Shimshoni, 1971; Duma, 1997; Duma and Vilardo, 1998. This also applies to strong earthquake activity. Moreover, recent observations reveal an involvement of the regular diurnal variations of the Earth’s magnetic field, commonly known as Sq-variations, in this geodynamic process of changing earthquake activity with the time of day (Duma, 1996, 1999. In the article it is attempted to quantify the forces which result from the interaction between the induced Sq-variation currents in the Earth’s lithosphere and the regional Earth’s magnetic field, in order to assess the influence on the tectonic stress field and on seismic activity. A reliable model is obtained, which indicates a high energy involved in this process. The effect of Sq-induction is compared with the results of the large scale electromagnetic experiment "Khibiny" (Velikhov, 1989, where a giant artificial current loop was activated in the Barents Sea.

  12. Study on the Diurnal Variation of the Plasma Immunoreactive Glucagon

    International Nuclear Information System (INIS)

    Lee, Hong Kyu; Hong, Kee Suk; Kim, Byoung Kook; Koh, Chang Soon; Chung, June Key; Kim, Eui Chong

    1984-01-01

    It is well known that glucagon, like insulin, is very important in the moment-to-moment control of the homeostasis of glucose, and of amino acids. Glucagon has been shown to have potent glycogenolytic, gluconeogenic and lipolytic activities. Attention to its role in the pathogenesis of diabetes mellitus and hypoglycemia has been also advanced recently. To evaluate the diurnal variation of plasma glucagon concentration, we measured serum glucose, insulin, and plasma glucagon every 30 minutes or every hour in 7 normal Korean adults. Results were as follows: 1) Although plasma glucagon concentration showed wide individual variations, it had a tendency to decrease after meals. After lunch and dinner, plasma glucagon concentration had gradually declined and reached its nadir at postprandial 2-2.5 hours. The minimal level of plasma glucagon was at 4 A.M. 2) Serum insulin:plasma glucagon ratios were increased promptly after meals. Especially after lunch, its peak was prominent (3.65 ± 1. 95). The minimal level of serum insulin:plasma glucagon ratio appeared at 6 A.M.

  13. Study on the Diurnal Variation of the Plasma Immunoreactive Glucagon

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hong Kyu; Hong, Kee Suk; Kim, Byoung Kook; Koh, Chang Soon [Seoul National University College of Medicine, Seoul (Korea, Republic of); Chung, June Key; Kim, Eui Chong [Seoul District Armed Forces General Hospital, Seoul (Korea, Republic of)

    1984-03-15

    It is well known that glucagon, like insulin, is very important in the moment-to-moment control of the homeostasis of glucose, and of amino acids. Glucagon has been shown to have potent glycogenolytic, gluconeogenic and lipolytic activities. Attention to its role in the pathogenesis of diabetes mellitus and hypoglycemia has been also advanced recently. To evaluate the diurnal variation of plasma glucagon concentration, we measured serum glucose, insulin, and plasma glucagon every 30 minutes or every hour in 7 normal Korean adults. Results were as follows: 1) Although plasma glucagon concentration showed wide individual variations, it had a tendency to decrease after meals. After lunch and dinner, plasma glucagon concentration had gradually declined and reached its nadir at postprandial 2-2.5 hours. The minimal level of plasma glucagon was at 4 A.M. 2) Serum insulin:plasma glucagon ratios were increased promptly after meals. Especially after lunch, its peak was prominent (3.65 +- 1. 95). The minimal level of serum insulin:plasma glucagon ratio appeared at 6 A.M.

  14. Estimation of paracetamol in urine to assess the diurnal variation

    Directory of Open Access Journals (Sweden)

    Mithun Chandro Bhowmik

    2018-05-01

    Full Text Available The aim of the present study was to evaluate the diurnal variation of the pharmacokinetics of paracetamol by estimating the urinary free paracetamol level after single oral administration of paracetamol (500 mg tablet to 24 healthy male volunteers (students of a Medical College. The volunteers were given paracetamol tablet at 0800, 1400 and 2000 hours in three different days (two weeks apart and the urine samples of the volunteers were collected at just before and four hours after paracetamol administration. The samples were analyzed for free paracetamol using HPLC. The mean age was 21.1 ± 1.3 years and the body weight was 63.9 ± 10.9 kg. Three peaks were detected in the HPLC and one of them was identified for free paracetamol (RT= 4.7 min. The urine volume was nearly similar in all three times. After administration at 0800 hour, total free paracetamol excretion was significantly more than at 1400 and 2000 hours (p<0.001. The present study indicates that the dose reduction of paracetamol is required at morning than the afternoon or evening dose. 

  15. Improvement of Diurnal Blood Pressure Variation by Azilsartan.

    Science.gov (United States)

    Okamura, Keisuke; Shirai, Kazuyuki; Okuda, Tetsu; Urata, Hidenori

    2018-01-01

    Azilsartan is an angiotensin II receptor blocker with a potent antihypertensive effect. In a multicenter, prospective, open-label study, 265 patients with poor blood pressure control despite treatment with other angiotensin II receptor blockers were switched to 20 mg/day of azilsartan (patients on standard dosages) or 40 mg/day of azilsartan (patients on high dosages). Blood pressure was 149/83 mm Hg before switching and was significantly reduced from 1 month after switching until final assessment (132/76 mm Hg, P < 0.001). The pulse rate was 72/min before switching and increased significantly from 3 months after switching until final assessment (74/min, P < 0.005). A significant decrease of home morning systolic and diastolic pressure was observed from 1 and 3 months, respectively. Home morning blood pressure was 143/82 mm Hg before switching and 130/76 mm Hg at final assessment (P < 0.01). The morning-evening difference of systolic blood pressure decreased from 14.6 to 6.6 mm Hg after switching (P = 0.09). The estimated glomerular filtration rate was significantly decreased at 3, 6, and 12 months after switching, and serum uric acid was significantly increased at 12 months. No serious adverse events occurred. Azilsartan significantly reduced the blood pressure and decreased diurnal variation in patients responding poorly to other angiotensin II receptor blockers.

  16. Diurnal Variations of Titan's Surface Temperatures From Cassini -CIRS Observations

    Science.gov (United States)

    Cottini, Valeria; Nixon, Conor; Jennings, Don; Anderson, Carrie; Samuelson, Robert; Irwin, Patrick; Flasar, F. Michael

    The Cassini Composite Infrared Spectrometer (CIRS) observations of Saturn's largest moon, Titan, are providing us with the ability to detect the surface temperature of the planet by studying its outgoing radiance through a spectral window in the thermal infrared at 19 m (530 cm-1) characterized by low opacity. Since the first acquisitions of CIRS Titan data the in-strument has gathered a large amount of spectra covering a wide range of latitudes, longitudes and local times. We retrieve the surface temperature and the atmospheric temperature pro-file by modeling proper zonally averaged spectra of nadir observations with radiative transfer computations. Our forward model uses the correlated-k approximation for spectral opacity to calculate the emitted radiance, including contributions from collision induced pairs of CH4, N2 and H2, haze, and gaseous emission lines (Irwin et al. 2008). The retrieval method uses a non-linear least-squares optimal estimation technique to iteratively adjust the model parameters to achieve a spectral fit (Rodgers 2000). We show an accurate selection of the wide amount of data available in terms of footprint diameter on the planet and observational conditions, together with the retrieved results. Our results represent formal retrievals of surface brightness temperatures from the Cassini CIRS dataset using a full radiative transfer treatment, and we compare to the earlier findings of Jennings et al. (2009). The application of our methodology over wide areas has increased the planet coverage and accuracy of our knowledge of Titan's surface brightness temperature. In particular we had the chance to look for diurnal variations in surface temperature around the equator: a trend with slowly increasing temperature toward the late afternoon reveals that diurnal temperature changes are present on Titan surface. References: Irwin, P.G.J., et al.: "The NEMESIS planetary atmosphere radiative transfer and retrieval tool" (2008). JQSRT, Vol. 109, pp

  17. Diurnal variation of intraoral pH and temperature.

    Science.gov (United States)

    Choi, Jung Eun; Lyons, Karl M; Kieser, Jules A; Waddell, Neil J

    2017-01-01

    The aim of this study was to measure continuously the intraoral pH and temperature of healthy individuals to investigate their diurnal variations. Seventeen participants (mean age, 31±9 years) wore a custom-made intraoral appliance fitted with a pH probe and thermocouple for two sets of 24 h, while carrying out normal daily activities including sleep. The continuous changes in intraoral pH and temperature were captured using a sensor placed on the palatal aspect of the upper central incisors. The collected data were categorised into different status (awake and sleep) and periods (morning, afternoon, evening and night). Both quantitative and qualitative analyses were conducted. The intraoral pH change was found to show a distinctive daily rhythm, showing a 12-h interval between maximum (7.73) and minimum (6.6) pH values. The maximum and minimum values were found to repeat after 24 h. The mean pH over 48 h (two sets of 24 h) was found to be 7.27 (±0.74). There was significant difference found in pH when subjects were awake and asleep and different periods during the day ( P pH. There was a significant difference found in temperature depending on the time of the day, except between morning and afternoon ( P =0.78). Our results showed that there is a distinctive daily, circadian-like pattern in intraoral pH variation over a 24-h period, which has been considered as one of the risk factors in sleep-related dental diseases.

  18. Standardised Resting Time Prior to Blood Sampling and Diurnal Variation Associated with Risk of Patient Misclassification

    DEFF Research Database (Denmark)

    Bøgh Andersen, Ida; Brasen, Claus L.; Christensen, Henry

    2015-01-01

    .9×10-7) and sodium (p = 8.7×10-16). Only TSH and albumin were clinically significantly influenced by diurnal variation. Resting time had no clinically significant effect. CONCLUSIONS: We found no need for resting 15 minutes prior to blood sampling. However, diurnal variation was found to have a significant......BACKGROUND: According to current recommendations, blood samples should be taken in the morning after 15 minutes' resting time. Some components exhibit diurnal variation and in response to pressures to expand opening hours and reduce waiting time, the aims of this study were to investigate...... the impact of resting time prior to blood sampling and diurnal variation on biochemical components, including albumin, thyrotropin (TSH), total calcium and sodium in plasma. METHODS: All patients referred to an outpatient clinic for blood sampling were included in the period Nov 2011 until June 2014 (opening...

  19. Nighttime Convection, Temperature Inversions, and Diurnal Variations at Low Altitudes in the Martian Tropics

    Science.gov (United States)

    Hinson, D. P.; Haberle, R. M.; Spiga, A.; Tellmann, S.; Paetzold, M.; Asmar, S. W.; Haeusler, B.

    2014-07-01

    We are using radio occultation measurements and numerical simulations to explore the atmospheric structure and diurnal variations in the lowest few scale heights of the martian atmosphere, with emphasis on nighttime convective layers.

  20. Diurnal variation in glycogen phosphorylase activity in rat liver. A quantitative histochemical study

    NARCIS (Netherlands)

    Frederiks, W. M.; Marx, F.; Bosch, K. S.

    1987-01-01

    The diurnal variations of the glycogen content and of glycogen phosphorylase activity in periportal and pericentral areas of rat liver parenchyma have been analyzed in periodic acid Schiff (PAS)-stained cryostat sections using quantitative microdensitometry. Glycogen content and phosphorylase

  1. Seasonal variation in diurnal atmospheric grass pollen concentration profiles

    DEFF Research Database (Denmark)

    Peel, Robert George; Ørby, Pia Viuf; Skjøth, Carsten Ambelas

    2014-01-01

    the time of day when peak concentrations are most likely to occur using seasonally averaged diurnal profiles. Atmospheric pollen loads are highly dependent upon emissions, and different species of grass are known to flower and emit pollen at different times of the day and during different periods......In this study, the diurnal atmospheric grass pollen concentration profile within the Danish city of Aarhus was shown to change in a systematic manner as the pollen season progressed. Although diurnal grass pollen profiles can differ greatly from day-to-day, it is common practice to establish...... of the pollen season. Pollen concentrations are also influenced by meteorological factors - directly through those parameters that govern pollen dispersion and transport, and indirectly through the weather-driven flowering process. We found that three different profiles dominated the grass pollen season...

  2. Seasonal and diurnal variations of ocular pressure in ocular hypertensive subjects in Pakistan.

    Science.gov (United States)

    Qureshi, I A; Xiao, R X; Yang, B H; Zhang, J; Xiang, D W; Hui, J L

    1999-05-01

    Studies have been shown that intraocular pressure (IOP) shows a diurnal variation in ocular hypertensive subjects, but the amount of change differs from study to study. In recent years it has been noted that intraocular pressure is a dynamic function and is subjected to many influences both acutely and over the long term. The variability in the results may be due to negligence of factors that can affect IOP. Moreover, seasonal variations in the ocular hypertensive subjects have never been described. After placing control on those factors that can affect IOP, this study investigated seasonal and diurnal variations in IOP of ocular hypertensive subjects. IOP was measured each month over the course of 12 months with the Goldmann applanation tonometer in 91 ocular hypertensive male subjects. To see the diurnal changes, subjects were asked to stay in the hospital for 24 hours. The average IOP in the winter months was higher than those in spring, summer, and autumn. The IOP difference between winter and summer was (mean +/- sem) 2.9 +/- 0.9 mmHg (p < 0.001). The peak of mean IOP in diurnal variation curve (25.7 +/- 1.2 mmHg) appeared in the morning when the subjects had just awaken. The mean diurnal variation was found to be 4.2 +/- 0.6 mmHg (p < 0.001). This study confirms that seasons influence IOP and it shows diurnal variations. As compared to other nations, diurnal variations in ocular hypertensive subjects seem to be somewhat less in Pakistan. Knowledge of the seasonal and diurnal variations in IOP may help glaucoma screeners.

  3. Analysis of the Diurnal Variation of the Global Electric Circuit Obtained From Different Numerical Models

    Science.gov (United States)

    Jánský, Jaroslav; Lucas, Greg M.; Kalb, Christina; Bayona, Victor; Peterson, Michael J.; Deierling, Wiebke; Flyer, Natasha; Pasko, Victor P.

    2017-12-01

    This work analyzes different current source and conductivity parameterizations and their influence on the diurnal variation of the global electric circuit (GEC). The diurnal variations of the current source parameterizations obtained using electric field and conductivity measurements from plane overflights combined with global Tropical Rainfall Measuring Mission satellite data give generally good agreement with measured diurnal variation of the electric field at Vostok, Antarctica, where reference experimental measurements are performed. An approach employing 85 GHz passive microwave observations to infer currents within the GEC is compared and shows the best agreement in amplitude and phase with experimental measurements. To study the conductivity influence, GEC models solving the continuity equation in 3-D are used to calculate atmospheric resistance using yearly averaged conductivity obtained from the global circulation model Community Earth System Model (CESM). Then, using current source parameterization combining mean currents and global counts of electrified clouds, if the exponential conductivity is substituted by the conductivity from CESM, the peak to peak diurnal variation of the ionospheric potential of the GEC decreases from 24% to 20%. The main reason for the change is the presence of clouds while effects of 222Rn ionization, aerosols, and topography are less pronounced. The simulated peak to peak diurnal variation of the electric field at Vostok is increased from 15% to 18% from the diurnal variation of the global current in the GEC if conductivity from CESM is used.

  4. Diurnal variation of precipitation over the Carolina Sandhills region

    Indian Academy of Sciences (India)

    State Climate Office of North Carolina, Raleigh, NC 27695-8208, USA. ∗ e-mail: ... of the weather forecast models experience problems in accounting for the ... effect of vegetation and soil contrasts on thermally induced flow is ... Sandhills; diurnal convection; heat flux gradients; cloud–radiation interaction. J. Earth Syst. Sci.

  5. Diurnal Variation in the Basal Emission Rate of Isoprene

    Science.gov (United States)

    Jennifer Funk; Clive G. Jones; Christine J. Baker; Heather M. Fuller; Christian P. Giardina; Manuel T. Lerdua

    2003-01-01

    Isoprene is emitted from numerous plant species and profoundly influences tropospheric chemistry. Due to the short lifetime of isoprene in the atmosphere, developing an understanding of emission patterns at small time scales is essential for modeling regional atmospheric chemistry processes. Previous studies suggest that diurnal fluctuations in isoprene emission may be...

  6. Simulation of the Universal-Time Diurnal Variation of the Global Electric Circuit Charging Rate

    Science.gov (United States)

    Mackerras, D.; Darvenzia, M.; Orville, R. E.; Williams, E. R.; Goodman, S. J.

    1999-01-01

    A global lightning model that includes diurnal and annual lightning variation, and total flash density versus latitude for each major land and ocean, has been used as the basis for simulating the global electric circuit charging rate. A particular objective has been to reconcile the difference in amplitude ratios [AR=(max-min)/mean] between global lightning diurnal variation (AR approx. = 0.8) and the diurnal variation of typical atmospheric potential gradient curves (AR approx. = 0.35). A constraint on the simulation is that the annual mean charging current should be about 1000 A. The global lightning model shows that negative ground flashes can contribute, at most, about 10-15% of the required current. For the purpose of the charging rate simulation, it was assumed that each ground flash contributes 5 C to the charging process. It was necessary to assume that all electrified clouds contribute to charging by means other than lightning, that the total flash rate can serve as an indirect indicator of the rate of charge transfer, and that oceanic electrified clouds contribute to charging even though they are relatively inefficient in producing lightning. It was also found necessary to add a diurnally invariant charging current component. By trial and error it was found that charging rate diurnal variation curves in Universal time (UT) could be produced with amplitude ratios and general shapes similar to those of the potential gradient diurnal variation curves measured over ocean and arctic regions during voyages of the Carnegie Institute research vessels.

  7. Diurnal variation of summer precipitation over the Tibetan Plateau. A cloud-resolving simulation

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Jianyu; Zhang, Bing; Wang, Minghuan [China Meteorological Administration, Wuhan (China). Wuhan Inst. of Heavy Rain; Wang, Huijuan [Weather Modification Office of Hubei Province, Wuhan (China)

    2012-07-01

    In this study, the Weather Research and Forecasting model was used to simulate the diurnal variation in summer precipitation over the Tibetan Plateau (TP) at a cloudresolving scale. Compared with the TRMM, precipitation data shows that the model can well simulate the diurnal rainfall cycle with an overall late-afternoon maximum precipitation in the central TP and a nighttime maximum in the southern edge. The simulated diurnal variations in regional circulation and thermodynamics are in good correspondence with the precipitation diurnal cycles in the central and southern edge of TP, respectively. A possible mechanism responsible for the nocturnal precipitation maximum in the southern edge has been proposed, indicating the importance of the TP in regulating the regional circulation and precipitation. (orig.)

  8. Diurnal variation of the human adipose transcriptome and the link to metabolic disease

    Directory of Open Access Journals (Sweden)

    Lamb John

    2009-02-01

    Full Text Available Abstract Background Circadian (diurnal rhythm is an integral part of the physiology of the body; specifically, sleep, feeding behavior and metabolism are tightly linked to the light-dark cycle dictated by earth's rotation. Methods The present study examines the effect of diurnal rhythm on gene expression in the subcutaneous adipose tissue of overweight to mildly obese, healthy individuals. In this well-controlled clinical study, adipose biopsies were taken in the morning, afternoon and evening from individuals in three study arms: treatment with the weight loss drug sibutramine/fasted, placebo/fed and placebo/fasted. Results The results indicated that diurnal rhythm was the most significant driver of gene expression variation in the human adipose tissue, with at least 25% of the genes having had significant changes in their expression levels during the course of the day. The mRNA expression levels of core clock genes at a specific time of day were consistent across multiple subjects on different days in all three arms, indicating robust diurnal regulation irrespective of potential confounding factors. The genes essential for energy metabolism and tissue physiology were part of the diurnal signature. We hypothesize that the diurnal transition of the expression of energy metabolism genes reflects the shift in the adipose tissue from an energy-expending state in the morning to an energy-storing state in the evening. Consistent with this hypothesis, the diurnal transition was delayed by fasting and treatment with sibutramine. Finally, an in silico comparison of the diurnal signature with data from the publicly-available Connectivity Map demonstrated a significant association with transcripts that were repressed by mTOR inhibitors, suggesting a possible link between mTOR signaling, diurnal gene expression and metabolic regulation. Conclusion Diurnal rhythm plays an important role in the physiology and regulation of energy metabolism in the adipose

  9. Diurnal variation in soil respiration under different land uses on Taihang Mountain, North China

    Science.gov (United States)

    Liu, Xiuping; Zhang, Wanjun; Zhang, Bin; Yang, Qihong; Chang, Jianguo; Hou, Ke

    2016-01-01

    The aim of this paper is to evaluate the diurnal variation in soil respiration under different land use types on Taihang Mountain, North China, and to understand its response to environmental factors (e.g., soil temperature and moisture) and forest management. Diurnal variations in soil respiration from plantations (Robinia pseudoacacia, Punica granatum, and Ziziphus jujuba), naturally regenerated forests (Vitex negundo var. heterophylla), grasslands (Bothriochloa ischaemum), and farmlands (winter wheat/summer maize) were measured using an LI-8100 automated soil CO2 flux system from May 2012 to April 2013. The results indicated that land use type had a significant effect on the diurnal variation of soil respiration. The diurnal soil respiration from farmlands was highest, followed by Ziziphus jujube, R. pseudoacacia, P. granatum, the lower soil CO2 efflux was found from B. ischaemum and V. negundo var. heterophylla. The diurnal soil respiration across different land use types was significantly affected by soil temperature and moisture, and their interaction. Precipitation-stimulated soil respiration increased more in soil with low water content and less in soil with high water content. The lower diurnal soil respiration from naturally regenerated forests suggests that naturally regenerated vegetation is the optimal vegetation type for reducing global warming.

  10. Diurnal variations in the UV albedo of arctic snow

    Directory of Open Access Journals (Sweden)

    O. Meinander

    2008-11-01

    Full Text Available The relevance of snow for climate studies is based on its physical properties, such as high surface reflectivity. Surface ultraviolet (UV albedo is an essential parameter for various applications based on radiative transfer modeling. Here, new continuous measurements of the local UV albedo of natural Arctic snow were made at Sodankylä (67°22'N, 26°39'E, 179 m a.s.l. during the spring of 2007. The data were logged at 1-min intervals. The accumulation of snow was up to 68 cm. The surface layer thickness varied from 0.5 to 35 cm with the snow grain size between 0.2 and 2.5 mm. The midday erythemally weighted UV albedo ranged from 0.6 to 0.8 in the accumulation period, and from 0.5 to 0.7 during melting. During the snow melt period, under cases of an almost clear sky and variable cloudiness, an unexpected diurnal decrease of 0.05 in albedo soon after midday, and recovery thereafter, was detected. This diurnal decrease in albedo was found to be asymmetric with respect to solar midday, thus indicating a change in the properties of the snow. Independent UV albedo results with two different types of instruments confirm these findings. The measured temperature of the snow surface was below 0°C on the following mornings. Hence, the reversible diurnal change, evident for ~1–2 h, could be explained by the daily metamorphosis of the surface of the snowpack, in which the temperature of the surface increases, melting some of the snow to liquid water, after which the surface freezes again.

  11. Diurnal Variations of Airborne Pollen and Spores in Taipei City, Taiwan

    Directory of Open Access Journals (Sweden)

    Yueh-Lin Yang

    2003-09-01

    Full Text Available The diurnal variation of airborne pollen and spores in Taipei City, Taiwan, was investigated during a two-year survey from 1993 to 1994. The pollen and spores were sampled using a Burkard seven-day volumetric pollen trap. The diurnal trends of the total amount of pollen and spores in 1993 and in 1994 were similar to each other, and peaked at 3 to 10 o’clock. The diurnal patterns of airborne pollen and spores of Broussonetia, Fraxinus, Cyathea and Gramineae in 1993 were similar to those in 1994. High concentrations of Broussonetia and Fraxinus were obtained from midnight to the next morning. Cyathea spores peaked from morning till noon, and Gramineae peaked in the afternoon. The diurnal patterns of airborne pollen of Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae in 1993 were different to those in 1994. Regular diurnal patterns also associated with the taxa, which produce large pollen or spores, such as Gramineae and Cyathea. In contrast, Bischofia, Juniperus, Mallotus, Morus, Trema and Urticaceae produce relatively small pollen and the diurnal patterns of their airborne pollen were found irregular. The source plants Broussonetia and Fraxinus were close to the collection site so the diurnal patterns of their airborne pollen were regular, suggesting that the diurnal fluctuations of the pollen or spores in air might be affected by the source of plants and the sizes of pollen or spores. The transportation of the smaller pollen or spores in air is probably more easily affected by instability of air currents; they are therefore more likely to exhibit irregular diurnal patterns.

  12. Is the diurnal pattern sufficient to explain the intraday variation in volatility? A nonparametric assessment

    DEFF Research Database (Denmark)

    Christensen, Kim; Hounyo, Ulrich; Podolskij, Mark

    In this paper, we propose a nonparametric way to test the hypothesis that time-variation in intraday volatility is caused solely by a deterministic and recurrent diurnal pattern. We assume that noisy high-frequency data from a discretely sampled jump-diffusion process are available. The test...... inference, we propose a new bootstrap approach, which leads to almost correctly sized tests of the null hypothesis. We apply the developed framework to a large cross-section of equity high-frequency data and find that the diurnal pattern accounts for a rather significant fraction of intraday variation...

  13. Absence of diurnal variation of C-reactive protein concentrations in healthy human subjects

    Science.gov (United States)

    Meier-Ewert, H. K.; Ridker, P. M.; Rifai, N.; Price, N.; Dinges, D. F.; Mullington, J. M.

    2001-01-01

    BACKGROUND: The concentration of C-reactive protein (CRP) in otherwise healthy subjects has been shown to predict future risk of myocardial infarction and stroke. CRP is synthesized by the liver in response to interleukin-6, the serum concentration of which is subject to diurnal variation. METHODS: To examine the existence of a time-of-day effect for baseline CRP values, we determined CRP concentrations in hourly blood samples drawn from healthy subjects (10 males, 3 females; age range, 21-35 years) during a baseline day in a controlled environment (8 h of nighttime sleep). RESULTS: Overall CRP concentrations were low, with only three subjects having CRP concentrations >2 mg/L. Comparison of raw data showed stability of CRP concentrations throughout the 24 h studied. When compared with cutoff values of CRP quintile derived from population-based studies, misclassification of greater than one quintile did not occur as a result of diurnal variation in any of the subjects studied. Nonparametric ANOVA comparing different time points showed no significant differences for both raw and z-transformed data. Analysis for rhythmic diurnal variation using a method fitting a cosine curve to the group data was negative. CONCLUSIONS: Our data show that baseline CRP concentrations are not subject to time-of-day variation and thus help to explain why CRP concentrations are a better predictor of vascular risk than interleukin-6. Determination of CRP for cardiovascular risk prediction may be performed without concern for diurnal variation.

  14. Diurnal variations in personal care products in seawater and mussels at three Mediterranean coastal sites.

    Science.gov (United States)

    Picot-Groz, Marina; Fenet, Hélène; Martinez Bueno, Maria Jesus; Rosain, David; Gomez, Elena

    2018-03-01

    The presence of personal care products (PCPs) in the marine environment is of major concern. PCPs, UV filters, and musks can enter the marine environment indirectly through wastewater or directly via recreational activities. We conducted this study to document patterns in the occurrence of seven PCPs at three coastal sites impacted by recreational activities during 1 day. The study focused on diurnal variations in these seven PCPs in seawater and indigenous mussels. In seawater, UV filters showed diurnal variations that mirrored variations in recreational activities at the sites. Ethylhexyl methoxycinnamate (EHMC) and octocrylene (OC) water concentrations increased from under the limit of quantification in the morning to 106 and 369 ng/L, respectively, when recreational activities were the highest. In mussels, diurnal variations in OC were observed, with the lowest concentrations recorded in the morning and then increasing throughout the day. As Mytilus spp. are widely used as sentinels in coastal pollution monitoring programs (mussel watch), our findings on diurnal variations could enhance sampling recommendations for recreational sites impacted by PCPs.

  15. No diurnal variation in rate or carbon isotope composition of soil respiration in a boreal forest

    International Nuclear Information System (INIS)

    Betson, N.R.; Gottlicher, S.G.; Hogberg, P.; Hall, M.; Wallin, G.; Richter, A.

    2007-01-01

    This study evaluated the diurnal variability in the rate and stable carbon isotope ratio ((delta) 13 C) of soil respiration in a northern boreal forest, measured with opaque chambers after the removal of understory vegetation. The experiment was conducted in June and August 2004 at the Picea abies L. Karst-dominated Flakaliden Research Forest in northern Sweden, using unfertilized girdled-tree plots and unfertilized non-girdled tree plots. Soil respiration and (delta) 13 C of soil-respired carbon dioxide (CO 2 ) were measured every 4 hours on 6 plots, with a total of 11 sampling times over each 48 hour period. The purpose was to clarify an earlier study regarding the origin of diurnal patterns of soil CO 2 flux. This study explored whether the diurnal patterns were the result of photosynthetic CO 2 uptake during the day by the understory or whether there were underlying trends in soil respiration driven by plant root allocation. The sampling campaigns undertaken in this study investigated whether diurnal variations in soil respiration rate and (delta) 13 C exist in this ecosystem when no understory vegetation is present. Shoot photosynthesis and environmental parameters were measured simultaneously. Despite significant variations in climatic conditions and shoot photosynthetic rates in non-girdled trees, no diurnal patterns in soil respiration rates and (delta) 13 C were noted in either treatment. The lack of detectable diurnal changes in both treatments indicates that modeling of daily boreal forest carbon balances based on single instantaneous measurements are unlikely to be misconstrued by substantial diurnal trends. However, it was suggested that spatial variable should be accounted for, given the large standard errors. The impact of tree girdling on soil respiration rates also emphasized the significance of canopy photosynthesis in driving soil processes. 37 refs., 2 figs

  16. Seasonal and diurnal variations of atmospheric mercury across the US determined from AMNet monitoring data

    Directory of Open Access Journals (Sweden)

    X. Lan

    2012-11-01

    Full Text Available Speciated atmospheric mercury observations collected over the period from 2008 to 2010 at the Environmental Protection Agency and National Atmospheric Deposition Program Atmospheric Mercury Network sites (AMNet were analyzed for its spatial, seasonal, and diurnal characteristics across the US. Median values of gaseous elemental mercury (GEM, gaseous oxidized mercury (GOM and particulate bound mercury (PBM at 11 different AMNet sites ranged from 148–226 ppqv (1.32–2.02 ng m−3, 0.05–1.4 ppqv (0.47–12.4 pg m−3 and 0.18–1.5 ppqv (1.61–13.7 pg m−3, respectively. Common characteristics of these sites were the similar median levels of GEM as well as its seasonality, with the highest mixing ratios occurring in winter and spring and the lowest in fall. However, discernible differences in monthly average GEM were as large as 30 ppqv, which may be caused by sporadic influence from local emission sources. The largest diurnal variation amplitude of GEM occurred in the summer. Seven rural sites displayed similar GEM summer diurnal patterns, in that the lowest levels appeared in the early morning, and then the GEM mixing ratio increased after sunrise and reached its maxima at noon or in the early afternoon. Unlike GEM, GOM exhibited higher mixing ratios in spring and summer. The largest diurnal variation amplitude of GOM occurred in spring for most AMNet sites. The GOM diurnal minima appeared before sunrise and maxima appeared in the afternoon. The increased GOM mixing ratio in the afternoon indicated a photochemically driven oxidation of GEM resulting in GOM formation. PBM exhibited diurnal fluctuations in summertime. The summertime PBM diurnal pattern displayed daily maxima in the early afternoon and lower mixing ratios at night, implying photochemical production of PBM in summer.

  17. Diurnal variations of summer precipitation over the regions east to Tibetan Plateau

    Science.gov (United States)

    Wu, Yang; Huang, Anning; Huang, Danqing; Chen, Fei; Yang, Ben; Zhou, Yang; Fang, Dexian; Zhang, Lujun; Wen, Lijuan

    2017-12-01

    Based on the hourly gauge-satellite merged precipitation product with the horizontal resolution of 0.1° latitude/longitude during 2008-2014, diurnal variations of the summer precipitation amount (PA), frequency (PF), and intensity (PI) with different duration time over the regions east to Tibetan Plateau have been systematically revealed in this study. Results indicate that the eight typical precipitation diurnal patterns identified by the cluster analysis display pronounced regional features among the plateaus, basins, plains, hilly and coastal areas. The precipitation diurnal cycles are significantly affected by the sub-grid terrain fluctuations. The PA, PF and PI of the total rainfall show much more pronounced double diurnal peaks with the sub-grid topography standard deviation (SD) decreased. Meanwhile, the diurnal peaks of PA and PF (PI) strengthen (weaken) with the sub-grid topography SD enhanced. Over the elevated mountain ranges, southeastern hilly and coastal regions, the PA and PF diurnal patterns of the total rainfall generally show predominant late-afternoon peaks, which are closely associated with the short-duration (≤slant 3 h) rainfall. Along the Tibetan Plateau to its downstream, the diurnal peaks of PA, PF and PI for the total rainfall all exhibit obvious eastward phase time delay mainly due to the diurnal evolutions of long-duration (> 6 h) rainfall. However, the 4-6 h rainfall leads to the eastward phase time delay of the total rainfall along the Taihang Mountains to its downstream. Further mechanism analysis suggests that the midnight to morning diurnal evolution of the long-duration rainfall is closely associated with the diurnal variations of the upward branches of thermally driven mountain-plain solenoids and the water vapor transport associated with the accelerated nocturnal southwesterly winds. The late-afternoon peak of the short-duration PA over the southeastern hilly and coastal regions is ascribed to the strong local thermal

  18. Diurnal variation in degradation of phytic acid by plant phytase in the pig stomach

    NARCIS (Netherlands)

    Kemme, P.A.; Jongbloed, A.W.; Mroz, Z.; Beynen, A.C.

    1998-01-01

    The effects of plant phytase on the gastric degradation of phytic acid and digestibilities of DM and P, and their diurnal variation were evaluated in pigs from 90 to 115 kg BW fitted with simple duodenal T-cannulas. Three diets were fed to three pigs in four collection periods according to a

  19. Seasonal and Diurnal Variations of Atmospheric Non-Methane Hydrocarbons in Guangzhou, China

    Directory of Open Access Journals (Sweden)

    Longfeng Li

    2012-05-01

    Full Text Available In recent decades, high ambient ozone concentrations have become one of the major regional air quality issues in the Pearl River Delta (PRD region. Non-methane hydrocarbons (NMHCs, as key precursors of ozone, were found to be the limiting factor in photochemical ozone formation for large areas in the PRD. For source apportioning of NMHCs as well as ozone pollution control strategies, it is necessary to obtain typical seasonal and diurnal patterns of NMHCs with a large pool of field data. To date, few studies have focused on seasonal and diurnal variations of NMHCs in urban areas of Guangzhou. This study explored the seasonal variations of most hydrocarbons concentrations with autumn maximum and spring minimum in Guangzhou. The diurnal variations of most anthropogenic NMHCs typically showed two-peak pattern with one at 8:00 in the morning and another at 20:00 in the evening, both corresponding to traffic rush hours in Guangzhou, whereas isoprene displayed a different bimodal diurnal curve. Propene, ethene, m, p-xylene and toluene were the four largest contributors to ozone formation in Guangzhou, based on the evaluation of individual NMHCs’ photochemical reactivity. Therefore, an effective strategy for controlling ozone pollution may be achieved by the reduction of vehicle emissions in Guangzhou.

  20. Regimes of Diurnal Variation of Summer Rainfall over Subtropical East Asia

    Energy Technology Data Exchange (ETDEWEB)

    Yuan W.; Lin W.; Yu, R.; Zhang, M.; Chen, H.; Li, J.

    2012-05-01

    Using hourly rain gauge records and Tropical Rainfall Measuring Mission 3B42 from 1998 to 2006, the authors present an analysis of the diurnal characteristics of summer rainfall over subtropical East Asia. The study shows that there are four different regimes of distinct diurnal variation of rainfall in both the rain gauge and the satellite data. They are located over the Tibetan Plateau with late-afternoon and midnight peaks, in the western China plain with midnight to early-morning peaks, in the eastern China plain with double peaks in late afternoon and early morning, and over the East China Sea with an early-morning peak. No propagation of diurnal phases is found from the land to the ocean across the coastlines. The different diurnal regimes are highly correlated with the inhomogeneous underlying surface, such as the plateau, plain, and ocean, with physical mechanisms consistent with the large-scale 'mountain-valley' and 'land-sea' breezes and convective instability. These diurnal characteristics over subtropical East Asia can be used as diagnostic metrics to evaluate the physical parameterization and hydrological cycle of climate models over East Asia.

  1. Diurnal and day-to-day variation of isometric muscle strength in myasthenia gravis.

    Science.gov (United States)

    Vinge, Lotte; Jakobsen, Johannes; Pedersen, Asger Roer; Andersen, Henning

    2016-01-01

    In patients with myasthenia gravis (MG), muscle strength is expected to decrease gradually during the day due to physical activities. Isometric muscle strength at the shoulder, knee, and ankle was determined in 10 MG patients (MGFA class II-IV) who were receiving usual medical treatment and in 10 control subjects. To determine diurnal and day-to-day variation, muscle strength was measured 4 times during day 1 and once at day 2. Knee extension strength decreased during the day in both patients and controls. Neither diurnal nor day-to-day variation of muscle strength was higher in patients compared with controls. Patients with mild to moderate MG did not have increased variation of isometric muscle strength during the day or from day-to-day compared with controls. This suggests that isometric muscle performance can be determined with high reproducibility in similar groups of MG patients without regard to time of day. © 2015 Wiley Periodicals, Inc.

  2. Diurnal modulation and sources of variation affecting ventricular repolarization in Warmblood horses

    DEFF Research Database (Denmark)

    Pedersen, Philip Juul; Moeller, Sine B.; Madsen, Mette Flethøj

    2014-01-01

    Te) are used as repolarization markers. To support the use of these markers in horses, we sought to describe the possible influence of the environment, time of day, day-to-day effects, T wave conformation, age, body weight (BW), and horse-to-horse variation on repolarization measurements. ANIMALS: 12 Warmblood...... affecting these intervals. RESULTS: Differences between individual horses were the largest source of repolarization variability although the environment had a significant effect on repolarization as well. Diurnal variation affected both the RR interval and the repolarization markers. The QT, QTc and Tp......, diurnal variation, the environment, and T wave conformation. These factors must be considered if markers of equine repolarization are used diagnostically....

  3. Topography induced spatial variations in diurnal cycles of assimilation and latent heat of Mediterranean forest

    Science.gov (United States)

    van der Tol, C.; Dolman, A. J.; Waterloo, M. J.; Raspor, K.

    2007-02-01

    The aim of this study is to explain topography induced spatial variations in the diurnal cycles of assimilation and latent heat of Mediterranean forest. Spatial variations of the fluxes are caused by variations in weather conditions and in vegetation characteristics. Weather conditions reflect short-term effects of climate, whereas vegetation characteristics, through adaptation and acclimation, long-term effects of climate. In this study measurements of plant physiology and weather conditions are used to explain observed differences in the fluxes. A model is used to study which part of the differences in the fluxes is caused by weather conditions and which part by vegetation characteristics. Data were collected at four experimental sub-Mediterranean deciduous forest plots in a heterogeneous terrain with contrasting aspect, soil water availability, humidity and temperature. We used a sun-shade model to scale fluxes from leaf to canopy, and calculated the canopy energy balance. Parameter values were derived from measurements of light interception, leaf chamber photosynthesis, leaf nitrogen content and 13C isotope discrimination in leaf material. Leaf nitrogen content is a measure of photosynthetic capacity, and 13C isotope discrimination of water use efficiency. For validation, sap-flux based measurements of transpiration were used. The model predicted diurnal cycles of transpiration and stomatal conductance, both their magnitudes and differences in afternoon stomatal closure between slopes of different aspect within the confidence interval of the validation data. Weather conditions mainly responsible for the shape of the diurnal cycles, and vegetation parameters for the magnitude of the fluxes. Although the data do not allow for a quantification of the two effects, the differences in vegetation parameters and weather among the plots and the sensitivity of the fluxes to them suggest that the diurnal cycles were more strongly affected by spatial variations in

  4. Topography induced spatial variations in diurnal cycles of assimilation and latent heat of Mediterranean forest

    Directory of Open Access Journals (Sweden)

    C. van der Tol

    2007-01-01

    Full Text Available The aim of this study is to explain topography induced spatial variations in the diurnal cycles of assimilation and latent heat of Mediterranean forest. Spatial variations of the fluxes are caused by variations in weather conditions and in vegetation characteristics. Weather conditions reflect short-term effects of climate, whereas vegetation characteristics, through adaptation and acclimation, long-term effects of climate. In this study measurements of plant physiology and weather conditions are used to explain observed differences in the fluxes. A model is used to study which part of the differences in the fluxes is caused by weather conditions and which part by vegetation characteristics. Data were collected at four experimental sub-Mediterranean deciduous forest plots in a heterogeneous terrain with contrasting aspect, soil water availability, humidity and temperature. We used a sun-shade model to scale fluxes from leaf to canopy, and calculated the canopy energy balance. Parameter values were derived from measurements of light interception, leaf chamber photosynthesis, leaf nitrogen content and 13C isotope discrimination in leaf material. Leaf nitrogen content is a measure of photosynthetic capacity, and 13C isotope discrimination of water use efficiency. For validation, sap-flux based measurements of transpiration were used. The model predicted diurnal cycles of transpiration and stomatal conductance, both their magnitudes and differences in afternoon stomatal closure between slopes of different aspect within the confidence interval of the validation data. Weather conditions mainly responsible for the shape of the diurnal cycles, and vegetation parameters for the magnitude of the fluxes. Although the data do not allow for a quantification of the two effects, the differences in vegetation parameters and weather among the plots and the sensitivity of the fluxes to them suggest that the diurnal cycles were more strongly affected by spatial

  5. Radiation balance at the surface in the city of São Paulo, Brazil: diurnal and seasonal variations

    NARCIS (Netherlands)

    Ferreira, M.J.; Oliveira, de A.P.; Soares, J.; Codato, G.; Wilde Barbaro, E.; Escobedo, J.F.

    2012-01-01

    The main goal of this work is to describe the diurnal and seasonal variations of the radiation balance components at the surface in the city of São Paulo based on observations carried out during 2004. Monthly average hourly values indicate that the amplitudes of the diurnal cycles of net radiation

  6. Combined diurnal variations of discharge and hydrochemistry of the Isunnguata Sermia outlet, Greenland Ice Sheet

    Science.gov (United States)

    Graly, Joseph; Harrington, Joel; Humphrey, Neil

    2017-05-01

    In order to examine daily cycles in meltwater routing and storage in the Isunnguata Sermia outlet of the Greenland Ice Sheet, variations in outlet stream discharge and in major element hydrochemistry were assessed over a 6-day period in July 2013. Over 4 days, discharge was assessed from hourly photography of the outlet from multiple vantages, including where midstream naled ice provided a natural gauge. pH, electrical conductivity, suspended sediment, and major element and anion chemistry were measured in samples of stream water collected every 3 h.Photography and stream observations reveal that although river width and stage have only slight diurnal variation, there are large diurnal changes in discharge shown by the doubling in width of what we term the active channel, which is characterized by large standing waves and fast flow. The concentration of dissolved solutes follows a sinusoidal diurnal cycle, except for large and variable increases in dissolved solutes during the stream's waning flow. Solute concentrations vary by ˜ 30 % between diurnal minima and maxima. Discharge maxima and minima lag temperature and surface melt by 3-7 h; diurnal solute concentration minima and maxima lag discharge by 3-6 h.This phase shift between discharge and solute concentration suggests that during high flow, water is either encountering more rock material or is stored in longer contact with rock material. We suggest that expansion of a distributed subglacial hydrologic network into seldom accessed regions during high flow could account for these phenomena, and for a spike of partial silicate reaction products during waning flow, which itself suggests a pressure threshold-triggered release of stored water.

  7. Seasonal and diurnal variations in potential alpha energy concentrations at a location in tropical Australia

    International Nuclear Information System (INIS)

    Quintarelli, F.; Akber, R.

    1998-01-01

    Full text: Atmospheric concentrations of radon progeny activity were measured at two locations in tropical Australia during the time period 1992 - 1994. Meteorological parameters including atmospheric pressure, temperature and humidity were also recorded. The data were analysed for seasonal and diurnal variations, in order to establish correlations and associations amongst radon progeny concentrations and meteorological parameters. The paper describes the findings, including the attachment behaviour of radon progeny to ambient aerosol

  8. Diurnal and seasonal variations in surface methane at a tropical coastal station: Role of mesoscale meteorology.

    Science.gov (United States)

    Kavitha, M; Nair, Prabha R; Girach, I A; Aneesh, S; Sijikumar, S; Renju, R

    2018-08-01

    In view of the large uncertainties in the methane (CH 4 ) emission estimates and the large spatial gaps in its measurements, studies on near-surface CH 4 on regional basis become highly relevant. This paper presents the first time observational results of a study on the impacts of mesoscale meteorology on the temporal variations of near-surface CH 4 at a tropical coastal station, in India. It is based on the in-situ measurements conducted during January 2014 to August 2016, using an on-line CH 4 analyzer working on the principle of gas chromatography. The diurnal variation shows a daytime low (1898-1925ppbv) and nighttime high (1936-2022ppbv) extending till early morning hours. These changes are closely associated with the mesoscale circulations, namely Sea Breeze (SB) and Land Breeze (LB), as obtained through the meteorological observations, WRF simulations of the circulations and the diurnal variation of boundary layer height as observed by the Microwave Radiometer Profiler. The diurnal enhancement always coincides with the onset of LB. Several cases of different onset timings of LB were examined and results presented. The CH 4 mixing ratio also exhibits significant seasonal patterns being maximum in winter and minimum in pre-monsoon/monsoon with significant inter-annual variations, which is also reflected in diurnal patterns, and are associated with changing synoptic meteorology. This paper also presents an analysis of in-situ measured near-surface CH 4 , column averaged and upper tropospheric CH 4 retrieved by Atmospheric Infrared Sounder (AIRS) onboard Earth Observing System (EOS)/Aqua which gives insight into the vertical distribution of the CH 4 over the location. An attempt is also made to estimate the instantaneous radiative forcing for the measured CH 4 mixing ratio. Copyright © 2018 Elsevier B.V. All rights reserved.

  9. Mean diurnal variations of noctilucent clouds during 7 years of lidar observations at ALOMAR

    Directory of Open Access Journals (Sweden)

    J. Fiedler

    2005-06-01

    Full Text Available From 1997 to 2003, noctilucent clouds (NLC were observed by lidar above the ALOMAR observatory in Northern Norway (69° N during a total of 1880 measurement hours. This data set contains NLC signatures for 640h, covering all local times, even during the highest solar background conditions. After data limitation imposing a threshold value of 4x10-10m-1sr-1 for the volume backscatter coefficient of the NLC particles, a measure for the cloud brightness, local time dependencies of the NLC occurrence frequency, altitude, and brightness were determined. On average, over the 7 years NLC occurred during the whole day and preferably in the early morning hours, with a maximum occurrence frequency of ~40% between 4 and 7 LT. Splitting the data into weak and strong clouds yields almost identical amplitudes of diurnal and semidiurnal variations for the occurrence of weak clouds, whereas the strong clouds are dominated by the diurnal variation. NLC occurrence, altitude, as well as brightness, show a remarkable persistence concerning diurnal and semidiurnal variations from 1997 to 2003, suggesting that NLC above ALOMAR are significantly controlled by atmospheric tides. The observed mean anti-phase behavior between cloud altitude and brightness is attributed to a phase shift between the semidiurnal components by ~6h. Investigation of data for each individual year regarding the prevailing oscillation periods of the NLC parameters showed different phase relationships, leading to a complex variability in the cloud parameters.

  10. High-resolution magnetic resonance imaging of diurnal variations in rheumatoid arthritis

    International Nuclear Information System (INIS)

    Nicholas, R.S.

    2000-09-01

    This thesis describes work that uses high-resolution magnetic resonance imaging (MRI) to give an insight into the aetiology of rheumatoid arthritis (RA) with particular reference to characterising diurnal changes in joint stiffness in the metacarpophalangeal (MCP) joints. The study was performed on a targeted 1.1 T MRI scanner using specialised sequences, including 3-dimensional gradient-echo, magnetisation transfer (MT) and multiple gradient-echo. These enabled tissue-dependent parameters such as MT ratio, effective transverse relaxation time (T 2 *) and proton density (ρ) to be made. Preliminary reproducibility studies of the MRI measurements showed that MT ratio could be measured in vivo to an accuracy of better than 8%. This variation is due to repositioning errors and physiological changes. Equivalent variations in T 2 * and p were 23% and 16% respectively; these poorer figures were contributed to errors in fitting the data to an exponential curve. An MRI study monitoring the diurnal variation of stiffness in RA demonstrated better characterisation of the disease state using MT and T 2 * maps compared to standard gradient-echo imaging. Features associated with arthritis such as bone erosions and cysts were found in the control group and an MT age dependence was measured in the soft tissue on the superior margin of the joint. This region also exhibited a diurnal variation in MT ratio for the patient group. The interaction between this region of tissue and other structures (e.g. the sheath of extensor tendon) within the joint could be a possible cause of joint stiffness. An incidental finding of this study was that Ritchie joint score also showed a diurnal variation. This study has demonstrated that MRI can be used to make reproducible measurements of the diurnal variations in RA. The indication is that the soft tissues in the superior aspect of the joint may be responsible for the symptom of joint stiffness in the MCP joints and future studies should be

  11. Diurnal and annual variations of meteor rates at the arctic circle

    Directory of Open Access Journals (Sweden)

    W. Singer

    2004-01-01

    Full Text Available Meteors are an important source for (a the metal atoms of the upper atmosphere metal layers and (b for condensation nuclei, the existence of which are a prerequisite for the formation of noctilucent cloud particles in the polar mesopause region. For a better understanding of these phenomena, it would be helpful to know accurately the annual and diurnal variations of meteor rates. So far, these rates have been little studied at polar latitudes. Therefore we have used the 33 MHz meteor radar of the ALOMAR observatory at 69° N to measure the meteor rates at this location for two full annual cycles. This site, being within 3° of the Arctic circle, offers in addition an interesting capability: The axis of its antenna field points (almost towards the North ecliptic pole once each day of the year. In this particular viewing direction, the radar monitors the meteoroid influx from (almost the entire ecliptic Northern hemisphere. We report on the observed diurnal variations (averaged over one month of meteor rates and their significant alterations throughout the year. The ratio of maximum over minimum meteor rates throughout one diurnal cycle is in January and February about 5, from April through December 2.3±0.3. If compared with similar measurements at mid-latitudes, our expectation, that the amplitude of the diurnal variation is to decrease towards the North pole, is not really borne out. Observations with the antenna axis pointing towards the North ecliptic pole showed that the rate of deposition of meteoric dust is substantially larger during the Arctic NLC season than the annual mean deposition rate. The daylight meteor showers of the Arietids, Zeta Perseids, and Beta Taurids supposedly contribute considerably to the June maximum of meteor rates. We note, though, that with the radar antenna pointing as described above, all three meteor radiants are close to the local horizon but all three radiants were detected.

  12. Studying Diurnal Variations of Aerosols with NASA MERRA-2 Reanalysis Data

    Science.gov (United States)

    Shen, Suhung; Ostrenga, Dana M.; Zeng, Jian; Vollmer, Bruce E.

    2018-01-01

    Aerosols play an important role in atmospheric dynamics, climate variations, and Earth's energy cycle by altering the radiation balance in the atmosphere through interaction with clouds, providing fertilizer for forests and canopy, and as a supply of iron to the ocean over long time periods. Studies suggest that much of the feedback between dust aerosols and dynamics is associated with diurnal and synoptic scale variability. However, the lack of sub-daily resolution of aerosols from satellite observations makes it difficult to study the diurnal characteristics, especially over tropical and subtropical regions. Investigation of this topic utilizes over 37 years of simulated global aerosol products from NASA atmospheric reanalysis, in the second Modern-Era Retrospective analysis for Research and Applications (MERRA-2) data set, available from NASA Goddard Earth Science Data and Information Services Center (GES DISC). MERRA-2 covers the period 1980-present, and is continuing as an ongoing climate analysis. Aerosol assimilation is included throughout the period, using data from MODIS, MISR, AERONET, and AVHRR (in the pre-EOS period). The aerosols are assimilated using the MERRA-2 aerosol model, which interacts directly with radiation parameterization, and is radiatively coupled with atmospheric model dynamics in the Goddard Earth Observing System Model, Version 5 (GEOS-5). Hourly, monthly, and monthly diurnal data are available at spatial resolution of 0.5o x 0.625o (latitude x longitude). By using MERRA-2 hourly and monthly diurnal products, different aerosol diurnal variabilities are observed over North America, Africa, Asia, and Australia, that may be due to different meteorological conditions and aerosol sources. The presentation will also provide an overview of MERRA-2 data services at GES DISC, such as how to find and download data, and how to quickly visualize and analyze data online with Giovanni.

  13. Global Electric Circuit Diurnal Variation Derived from Storm Overflight and Satellite Optical Lightning Datasets

    Science.gov (United States)

    Mach, Douglas M.; Blakeslee, R. J.; Bateman, M. J.; Bailey, J. C.

    2011-01-01

    We have combined analyses of over 1000 high altitude aircraft observations of electrified clouds with diurnal lightning statistics from the Lightning Imaging Sensor (LIS) and Optical Transient Detector (OTD) to produce an estimate of the diurnal variation in the global electric circuit. Using basic assumptions about the mean storm currents as a function of flash rate and location, and the global electric circuit, our estimate of the current in the global electric circuit matches the Carnegie curve diurnal variation to within 4% for all but two short periods of time. The agreement with the Carnegie curve was obtained without any tuning or adjustment of the satellite or aircraft data. Mean contributions to the global electric circuit from land and ocean thunderstorms are 1.1 kA (land) and 0.7 kA (ocean). Contributions to the global electric circuit from ESCs are 0.22 kA for ocean storms and 0.04 kA for land storms. Using our analysis, the mean total conduction current for the global electric circuit is 2.0 kA.

  14. The impact of diurnal variations of air traffic on contrail radiative forcing

    Directory of Open Access Journals (Sweden)

    N. Stuber

    2007-06-01

    Full Text Available We combined high resolution aircraft flight data from the EU Fifth Framework Programme project AERO2k with analysis data from the ECMWF's integrated forecast system to calculate diurnally resolved 3-D contrail cover. We scaled the contrail cover in order to match observational data for the Bakan area (eastern-Atlantic/western-Europe.

    We found that less than 40% of the global distance travelled by aircraft is due to flights during local night time. Yet, due to the cancellation of shortwave and longwave effects during daytime, night time flights contribute a disproportional 60% to the global annual mean forcing. Under clear sky conditions the night flights contribute even more disproportionally at 76%. There are pronounced regional variations in night flying and the associated radiative forcing. Over parts of the North Atlantic flight corridor 75% of air traffic and 84% of the forcing occurs during local night, whereas only 35% of flights are during local night in South-East Asia, yet these contribute 68% of the radiative forcing. In general, regions with a significant local contrail radiative forcing are also regions for which night time flights amount to less than half of the daily total of flights. Therefore, neglecting diurnal variations in air traffic/contrail cover by assuming a diurnal mean contrail cover can over-estimate the global mean radiative forcing by up to 30%.

  15. Solar-diurnal variations of Cosmic rays (CR), connected with the passage of the Earth through the Neutral Layer of the Interplanetary Magnetic Fields (IMF) and the earthquake problem

    International Nuclear Information System (INIS)

    Khazaradze, N; Vanishvili, G; Bakradze, T; Bazerashvili, E; Kordzadze, L; Elizbarashvili, M

    2013-01-01

    Key explanation on effect of Fundamental Law of Momentum Conservation is given on the basis of Cosmo-Physical processes, which can be connected with all kinds of recently known geo-effective phenomena. Many works have been devoted to searches of extraterrestrial sources of generation of earthquake initiation preconditions. There is a direct indication on the fact in these works that all kinds of geo-active fluxes of plasma, which goes ahead of strong geomagnetic storms, concomitant to the earthquakes, may be served as favourable conditions for earthquake appearance. If in one group of works, the increase of seismic activity during geo-active solar flare is reported, then in the other group of works, there is the direct indication on the fact, that it is necessary to study the mechanism of generation of electro-magnetic emanation in the seismically active regions of Earth. Certain strong destructive earthquakes are putting in touch by some authors with the outburst of cosmic rays in distant regions of Universe during stellar explosion of supernovae. It's impossible to avoid our attention from announcement of 100% increase of hard component of cosmic radiation above Yerevan 30 minutes ahead of 1988 Spitak Earthquake. And finally, the data on article, in which is shown that about 75% of earthquakes with magnitude M≥6 takes place during traverse of neutral layer of Interplanetary Magnetic Field by the Earth, in the presence of good correlation with 11-years cycle of Solar Activity. Above mentioned geo-effective phenomena, with an increasable amount, can be reviewed in frame of the Law of Momentum Conservation, if we take into account the peculiarities of its development for a given specific cases.

  16. Diurnal variation in rates of calcification and carbonate sediment dissolution in Florida Bay

    Science.gov (United States)

    Yates, K.K.; Halley, R.B.

    2006-01-01

    Water quality and circulation in Florida Bay (a shallow, subtropical estuary in south Florida) are highly dependent upon the development and evolution of carbonate mud banks distributed throughout the Bay. Predicting the effect of natural and anthropogenic perturbations on carbonate sedimentation requires an understanding of annual, seasonal, and daily variations in the biogenic and inorganic processes affecting carbonate sediment precipitation and dissolution. In this study, net calcification rates were measured over diurnal cycles on 27 d during summer and winter from 1999 to 2003 on mud banks and four representative substrate types located within basins between mud banks. Substrate types that were measured in basins include seagrass beds of sparse and intermediate density Thalassia sp., mud bottom, and hard bottom communities. Changes in total alkalinity were used as a proxy for calcification and dissolution. On 22 d (81%), diurnal variation in rates of net calcification was observed. The highest rates of net carbonate sediment production (or lowest rates of net dissolution) generally occurred during daylight hours and ranged from 2.900 to -0.410 g CaCO3 m-2 d-1. The lowest rates of carbonate sediment production (or net sediment dissolution) occurred at night and ranged from 0.210 to -1.900 g CaCO3 m -2 night-1. During typical diurnal cycles, dissolution during the night consumed an average of 29% of sediment produced during the day on banks and 68% of sediment produced during the day in basins. Net sediment dissolution also occurred during daylight, but only when there was total cloud cover, high turbidity, or hypersalinity. Diurnal variation in calcification and dissolution in surface waters and surface sediments of Florida Bay is linked to cycling of carbon dioxide through photosynthesis and respiration. Estimation of long-term sediment accumulation rates from diurnal rates of carbonate sediment production measured in this study indicates an overall average

  17. Diurnal variations of humidity and ice water content in the tropical upper troposphere

    Directory of Open Access Journals (Sweden)

    P. Eriksson

    2010-12-01

    Full Text Available Observational results of diurnal variations of humidity from Odin-SMR and AURA-MLS, and cloud ice mass from Odin-SMR and CloudSat are presented for the first time. Comparisons show that the retrievals of humidity and cloud ice from these two satellite combinations are in good agreement. The retrieved data are combined from four almost evenly distributed times of the day allowing mean values, amplitudes and phases of the diurnal variations around 200 hpa to be estimated. This analysis is applied to six climatologically distinct regions, five located in the tropics and one over the subtropical northern Pacific Ocean. The strongest diurnal cycles are found over tropical land regions, where the amplitude is ~7 RHi for humidity and ~50% for ice mass. The greatest ice mass for these regions is found during the afternoon, and the humidity maximum is observed to lag this peak by ~6 h. Over tropical ocean regions the variations are smaller and the maxima in both ice mass and humidity are found during the early morning. Observed results are compared with output from three climate models (ECHAM, EC-EARTH and CAM3. Direct measurement-model comparisons were not possible because the measured and modelled cloud ice masses represent different quantities. To make a meaningful comparison, the amount of snow had to be estimated from diagnostic parameters of the models. There is a high probability that the models underestimate the average ice mass (outside the 1-σ uncertainty. The models also show clear deficiencies when it comes to amplitude and phase of the regional variations, but to varying degrees.

  18. Diurnal variations in wastewater characteristics at main out fall in Lahore

    International Nuclear Information System (INIS)

    Haider, H.; Ali, W.; Ali, W.

    2012-01-01

    Variations in the flow and pollutants concentrations during the day were monitored at the Main Out fall disposal station of the city of Lahore. The laboratory analysis of the wastewater samples collected at 2 hour interval on fifth and sixth May, 2009 for pH, temperature, alkalinity, hardness, Biochemical Oxygen Demand (BOD5), BOD5 Filtered, Total Kjeldahl Nitrogen (TKN), Ammonia Nitrogen (NH/sub 3/-N), chlorides, solids, turbidity, sulphates and nitrates were carried out. Average values and standard deviations were determined to assess the type of wastewater treatment. Correlation between BOD5 and BOD5 Filtered was developed through regression analysis. Diurnal variations in the Ultimate Biochemical Oxygen Demand (BODU) at the Main Out fall based on Carbonaceous Biochemical Oxygen Demand (CBODU) and Nitrogenous Biochemical Oxygen Demand (NBODU) are also estimated. The ratio between CBODU/NBODU ranges between 0.86 to 1.8 during a day at Main Out fall. This variation is primarily due to the large diurnal variation in CBODU values as a result of industrial activities in the study area. The BOD5/ TKN ratio varies between 3.3 and 6.9 and the calculated BODU (i.e., CBODU + NBODU) was found to be almost double of BOD5 during most part of the day primarily due to inclusion of NBOD. The study results reveal the importance of NBOD while designing the wastewater treatment facilities and implementing a water quality control strategy for the River Ravi. (author)

  19. Diurnal temperature variations affect development of a herbivorous arthropod pest and its predators.

    Directory of Open Access Journals (Sweden)

    Dominiek Vangansbeke

    Full Text Available The impact of daily temperature variations on arthropod life history remains woefully understudied compared to the large body of research that has been carried out on the effects of constant temperatures. However, diurnal varying temperature regimes more commonly represent the environment in which most organisms thrive. Such varying temperature regimes have been demonstrated to substantially affect development and reproduction of ectothermic organisms, generally in accordance with Jensen's inequality. In the present study we evaluated the impact of temperature alternations at 4 amplitudes (DTR0, +5, +10 and +15°C on the developmental rate of the predatory mites Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor (Acari: Phytoseiidae and their natural prey, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae. We have modelled their developmental rates as a function of temperature using both linear and nonlinear models. Diurnally alternating temperatures resulted in a faster development in the lower temperature range as compared to their corresponding mean constant temperatures, whereas the opposite was observed in the higher temperature range. Our results indicate that Jensen's inequality does not suffice to fully explain the differences in developmental rates at constant and alternating temperatures, suggesting additional physiological responses play a role. It is concluded that diurnal temperature range should not be ignored and should be incorporated in predictive models on the phenology of arthropod pests and their natural enemies and their performance in biological control programmes.

  20. Diurnal Temperature Variations Affect Development of a Herbivorous Arthropod Pest and its Predators

    Science.gov (United States)

    Vangansbeke, Dominiek; Audenaert, Joachim; Nguyen, Duc Tung; Verhoeven, Ruth; Gobin, Bruno; Tirry, Luc; De Clercq, Patrick

    2015-01-01

    The impact of daily temperature variations on arthropod life history remains woefully understudied compared to the large body of research that has been carried out on the effects of constant temperatures. However, diurnal varying temperature regimes more commonly represent the environment in which most organisms thrive. Such varying temperature regimes have been demonstrated to substantially affect development and reproduction of ectothermic organisms, generally in accordance with Jensen’s inequality. In the present study we evaluated the impact of temperature alternations at 4 amplitudes (DTR0, +5, +10 and +15°C) on the developmental rate of the predatory mites Phytoseiulus persimilis Athias-Henriot and Neoseiulus californicus McGregor (Acari: Phytoseiidae) and their natural prey, the two-spotted spider mite Tetranychus urticae Koch (Acari: Tetranychidae). We have modelled their developmental rates as a function of temperature using both linear and nonlinear models. Diurnally alternating temperatures resulted in a faster development in the lower temperature range as compared to their corresponding mean constant temperatures, whereas the opposite was observed in the higher temperature range. Our results indicate that Jensen’s inequality does not suffice to fully explain the differences in developmental rates at constant and alternating temperatures, suggesting additional physiological responses play a role. It is concluded that diurnal temperature range should not be ignored and should be incorporated in predictive models on the phenology of arthropod pests and their natural enemies and their performance in biological control programmes. PMID:25874697

  1. Diurnal variations of airborne fungal spores concentration in the town and rural area

    Directory of Open Access Journals (Sweden)

    Idalia Kasprzyk

    2012-12-01

    Full Text Available Airborne fungal spores were monitored in 2001-2002 in Rzeszów (town and its neighborhood. The aim of investigations was to ascertain if there were differences in diurnal variations of airborne fungal spores concentration between town and rural area. The sampling was carried out using volumetric method. Traps were located at the same heights - app. 12 m. Airborne spores were sampled continuously. Microscopical slides were prepared for each day. Analysis was carried out on one longitudinal band of 48 mm long divided into 24 segments corresponding following hours of day. The results were expressed as mean number of fungal spores per cubic meter per 24 hours. For this survey, five geni of allergenic fungi were selected: Alternaria, Botrytis, Cladosporium, Epicoccum, Ganoderma. The concentrations of their airborne spores were high or very high. It was calculated theoretical day, where the hourly count was the percentage mean of number of spores at that time every chosen day without rainfall from 2001 and 2001 years. The diurnal periodicity of Alternaria, Cladosporium, Epicoccum and Ganoderma showed one peak, while Botrytis two. Anamorphic spores peaked in the afternoon, while their minima occurred in the morning. The highest concentrations of Ganoderma basidiospores were at down or at night, but minima during the day. There were no clear differences in the peak values between two studied sites. The results indicate that maximum concentrations of all spores generally occurred a few hour earlier in the rural area than in the town. Probably, in the rural area airborne spores came from many local sources and their diurnal periodicity reflected rhythm of spore liberation. Towns are characterized by specific microclimate with higher temperature and wind blowing to the centre. In Rzeszów fungal spores could be transported outside and carried out by wind from distant sources. This study showed, among others, that habitat conditions are an important factors

  2. A study of diurnal variations of radon and thoron concentrations in different indoor environmental conditions

    International Nuclear Information System (INIS)

    Pant, Preeti; Prasad, Mukesh; Ramola, R.C.

    2015-01-01

    The measurements for diurnal variations in radon ( 222 Rn) and thoron ( 220 Rn) concentrations were performed in the different indoor conditions of Tehri Garhwal, Uttarakhand, India by using AlphaGUARD, Portable Radon Monitor and RAD7. While selecting the dwellings, the ventilation conditions, building materials, life style of the inhabitants and their exposure time indoors were also considered. The behavior of indoor radon and thoron concentrations was observed for different type of dwellings with different environmental conditions. The measurement techniques, results obtained and comparison of the results are discussed in details. (author)

  3. Diurnal microstructural variations in healthy adult brain revealed by diffusion tensor imaging.

    Directory of Open Access Journals (Sweden)

    Chunxiang Jiang

    Full Text Available Biorhythm is a fundamental property of human physiology. Changes in the extracellular space induced by cell swelling in response to the neural activity enable the in vivo characterization of cerebral microstructure by measuring the water diffusivity using diffusion tensor imaging (DTI. To study the diurnal microstructural alterations of human brain, fifteen right-handed healthy adult subjects were recruited for DTI studies in two repeated sessions (8∶30 AM and 8∶30 PM within a 24-hour interval. Fractional anisotropy (FA, apparent diffusion coefficient (ADC, axial (λ// and radial diffusivity (λ⊥ were compared pixel by pixel between the sessions for each subject. Significant increased morning measurements in FA, ADC, λ// and λ⊥ were seen in a wide range of brain areas involving frontal, parietal, temporal and occipital lobes. Prominent evening dominant λ⊥ (18.58% was detected in the right inferior temporal and ventral fusiform gyri. AM-PM variation of λ⊥ was substantially left side hemisphere dominant (p<0.05, while no hemispheric preference was observed for the same analysis for ADC (p = 0.77, λ// (p = 0.08 or FA (p = 0.25. The percentage change of ADC, λ//, λ⊥, and FA were 1.59%, 2.15%, 1.20% and 2.84%, respectively, for brain areas without diurnal diffusivity contrast. Microstructural variations may function as the substrates of the phasic neural activities in correspondence to the environment adaptation in a light-dark cycle. This research provided a baseline for researches in neuroscience, sleep medicine, psychological and psychiatric disorders, and necessitates that diurnal effect should be taken into account in following up studies using diffusion tensor quantities.

  4. Characterizations of the diurnal shapes of OI 630.0 nm dayglow intensity variations: inferences

    Directory of Open Access Journals (Sweden)

    D. Chakrabarty

    2002-11-01

    Full Text Available Measurements of OI 630.0 nm thermospheric dayglow emission by means of the Dayglow Photometer (DGP at Mt. Abu (24.6° N, 73.7° E, dip lat 19.09° N, a station under the crest of Equatorial Ionization Anomaly (EIA, reveal day-to-day changes in the shapes of the diurnal profiles of dayglow intensity variations. These shapes have been characterized using the magnetometer data from equatorial and low-latitude stations. Substantial changes have been noticed in the shapes of the dayglow intensity variations between 10:00–15:00 IST (Indian Standard Time during the days when normal and counter electrojet events are present over the equator. It is found that the width (the time span corresponding to 0.8 times the maximum dayglow intensity of the diurnal profile has a linear relationship with the integrated electrojet strength. Occasional deviation from this linear relationship is attributed to the presence of substantial mean meridional wind.Key words. Ionosphere (equatorial ionosphere; ionosphere – atmosphere interactions; ionospheric disturbances

  5. Characterizations of the diurnal shapes of OI 630.0 nm dayglow intensity variations: inferences

    Directory of Open Access Journals (Sweden)

    D. Chakrabarty

    Full Text Available Measurements of OI 630.0 nm thermospheric dayglow emission by means of the Dayglow Photometer (DGP at Mt. Abu (24.6° N, 73.7° E, dip lat 19.09° N, a station under the crest of Equatorial Ionization Anomaly (EIA, reveal day-to-day changes in the shapes of the diurnal profiles of dayglow intensity variations. These shapes have been characterized using the magnetometer data from equatorial and low-latitude stations. Substantial changes have been noticed in the shapes of the dayglow intensity variations between 10:00–15:00 IST (Indian Standard Time during the days when normal and counter electrojet events are present over the equator. It is found that the width (the time span corresponding to 0.8 times the maximum dayglow intensity of the diurnal profile has a linear relationship with the integrated electrojet strength. Occasional deviation from this linear relationship is attributed to the presence of substantial mean meridional wind.

    Key words. Ionosphere (equatorial ionosphere; ionosphere – atmosphere interactions; ionospheric disturbances

  6. Some analysis on the diurnal variation of rainfall over the Atlantic Ocean

    Science.gov (United States)

    Gill, T.; Perng, S.; Hughes, A.

    1981-01-01

    Data collected from the GARP Atlantic Tropical Experiment (GATE) was examined. The data were collected from 10,000 grid points arranged as a 100 x 100 array; each grid covered a 4 square km area. The amount of rainfall was measured every 15 minutes during the experiment periods using c-band radars. Two types of analyses were performed on the data: analysis of diurnal variation was done on each of grid points based on the rainfall averages at noon and at midnight, and time series analysis on selected grid points based on the hourly averages of rainfall. Since there are no known distribution model which best describes the rainfall amount, nonparametric methods were used to examine the diurnal variation. Kolmogorov-Smirnov test was used to test if the rainfalls at noon and at midnight have the same statistical distribution. Wilcoxon signed-rank test was used to test if the noon rainfall is heavier than, equal to, or lighter than the midnight rainfall. These tests were done on each of the 10,000 grid points at which the data are available.

  7. Diurnal variations in iron concentrations and expression of genes involved in iron absorption and metabolism in pigs.

    Science.gov (United States)

    Zhang, Yiming; Wan, Dan; Zhou, Xihong; Long, Ciming; Wu, Xin; Li, Lan; He, Liuqin; Huang, Pan; Chen, Shuai; Tan, Bie; Yin, Yulong

    2017-09-02

    Diurnal variations in serum iron levels have been well documented in clinical studies, and serum iron is an important diagnostic index for iron-deficiency anemia. However, the underlying mechanism of dynamic iron regulation in response to the circadian rhythm is still unclear. In this study, we investigated daily variations in iron status in the plasma and liver of pigs. The transcripts encoding key factors involved in iron uptake and homeostasis were evaluated. The results showed that iron levels in the plasma and liver exhibited diurnal rhythms. Diurnal variations were also observed in transcript levels of divalent metal transporter 1 (DMT1), membrane-associated ferric reductase 1 (DCYTB), and transferrin receptor (TfR) in the duodenum and jejunum, as well as hepcidin (HAMP) and TfR in the liver. Moreover, the results showed a network in which diurnal variations in systemic iron levels were tightly regulated by hepcidin and Tf/TfR via DCYTB and DMT1. These findings provide new insights into circadian iron homeostasis regulation. The diurnal variations in serum iron levels may also have pathophysiological implications for clinical diagnostics related to iron deficiency anemia in pigs. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Diurnal and Reproductive Stage-Dependent Variation of Parental Behaviour in Captive Zebra Finches.

    Directory of Open Access Journals (Sweden)

    Boglárka Morvai

    Full Text Available Parental care plays a key role in ontogeny, life-history trade-offs, sexual selection and intra-familial conflict. Studies focusing on understanding causes and consequences of variation in parental effort need to quantify parental behaviour accurately. The applied methods are, however, diverse even for a given species and type of parental effort, and rarely validated for accuracy. Here we focus on variability of parental behaviour from a methodological perspective to investigate the effect of different samplings on various estimates of parental effort. We used nest box cameras in a captive breeding population of zebra finches, Taeniopygia guttata, a widely used model system of sexual selection, intra-familial dynamics and parental care. We investigated diurnal and reproductive stage-dependent variation in parental effort (including incubation, brooding, nest attendance and number of feedings based on 12h and 3h continuous video-recordings taken at various reproductive stages. We then investigated whether shorter (1h sampling periods provided comparable estimates of overall parental effort and division of labour to those of longer (3h sampling periods. Our study confirmed female-biased division of labour during incubation, and showed that the difference between female and male effort diminishes with advancing reproductive stage. We found individually consistent parental behaviours within given days of incubation and nestling provisioning. Furthermore, parental behaviour was consistent over the different stages of incubation, however, only female brooding was consistent over nestling provisioning. Parental effort during incubation did not predict parental effort during nestling provisioning. Our analyses revealed that 1h sampling may be influenced heavily by stochastic and diurnal variation. We suggest using a single longer sampling period (3h may provide a consistent and accurate estimate for overall parental effort during incubation in zebra

  9. Diurnal Variations of the Flux Imbalance Over Homogeneous and Heterogeneous Landscapes

    Science.gov (United States)

    Zhou, Yanzhao; Li, Dan; Liu, Heping; Li, Xin

    2018-05-01

    It is well known that the sum of the turbulent sensible and latent heat fluxes as measured by the eddy-covariance method is systematically lower than the available energy (i.e., the net radiation minus the ground heat flux). We examine the separate and joint effects of diurnal and spatial variations of surface temperature on this flux imbalance in a dry convective boundary layer using the Weather Research and Forecasting model. Results show that, over homogeneous surfaces, the flux due to turbulent-organized structures is responsible for the imbalance, whereas over heterogeneous surfaces, the flux due to mesoscale or secondary circulations is the main contributor to the imbalance. Over homogeneous surfaces, the flux imbalance in free convective conditions exhibits a clear diurnal cycle, showing that the flux-imbalance magnitude slowly decreases during the morning period and rapidly increases during the afternoon period. However, in shear convective conditions, the flux-imbalance magnitude is much smaller, but slightly increases with time. The flux imbalance over heterogeneous surfaces exhibits a diurnal cycle under both free and shear convective conditions, which is similar to that over homogeneous surfaces in free convective conditions, and is also consistent with the general trend in the global observations. The rapid increase in the flux-imbalance magnitude during the afternoon period is mainly caused by the afternoon decay of the turbulent kinetic energy (TKE). Interestingly, over heterogeneous surfaces, the flux imbalance is linearly related to the TKE and the difference between the potential temperature and surface temperature, ΔT; the larger the TKE and ΔT values, the smaller the flux-imbalance magnitude.

  10. Diurnal Variation of Tropical Ice Cloud Microphysics inferred from Global Precipitation Measurement Microwave Imager (GPM-GMI)'s Polarimetric Measurement

    Science.gov (United States)

    Gong, J.; Zeng, X.; Wu, D. L.; Li, X.

    2017-12-01

    Diurnal variation of tropical ice cloud has been well observed and examined in terms of the area of coverage, occurring frequency, and total mass, but rarely on ice microphysical parameters (habit, size, orientation, etc.) because of lack of direct measurements of ice microphysics on a high temporal and spatial resolutions. This accounts for a great portion of the uncertainty in evaluating ice cloud's role on global radiation and hydrological budgets. The design of Global Precipitation Measurement (GPM) mission's procession orbit gives us an unprecedented opportunity to study the diurnal variation of ice microphysics on the global scale for the first time. Dominated by cloud ice scattering, high-frequency microwave polarimetric difference (PD, namely the brightness temperature difference between vertically- and horizontally-polarized paired channel measurements) from the GPM Microwave Imager (GMI) has been proven by our previous study to be very valuable to infer cloud ice microphysical properties. Using one year of PD measurements at 166 GHz, we found that cloud PD exhibits a strong diurnal cycle in the tropics (25S-25N). The peak PD amplitude varies as much as 35% over land, compared to only 6% over ocean. The diurnal cycle of the peak PD value is strongly anti-correlated with local ice cloud occurring frequency and the total ice mass with a leading period of 3 hours for the maximum correlation. The observed PD diurnal cycle can be explained by the change of ice crystal axial ratio. Using a radiative transfer model, we can simulate the observed 166 GHz PD-brightness temperature curve as well as its diurnal variation using different axial ratio values, which can be caused by the diurnal variation of ice microphysical properties including particle size, percentage of horizontally-aligned non-spherical particles, and ice habit. The leading of the change of PD ahead of ice cloud mass and occurring frequency implies the important role microphysics play in the

  11. Does diurnal variation in cough reflex testing exist in healthy young adults?

    Science.gov (United States)

    Perry, Sarah; Huckabee, Maggie-Lee

    2017-05-01

    The aim of this study was to investigate whether diurnal variation in cough reflex sensitivity exists in healthy young adults when a tidal-breathing method is used. Fifty-three participants (19-37 years) underwent cough reflex testing on two occasions: once in the morning (between 9 am - midday) and once in the afternoon (between 2-5 pm). The order of testing was counter-balanced. Within each assessment, participants inhaled successively higher citric acid concentrations via a facemask, with saline solution randomly interspersed to control for a placebo response. The lowest concentration that elicited a reflexive cough response was recorded. Morning cough thresholds (mean=0.6mol/L) were not different from afternoon cough thresholds (mean=0.6mol/L), p=0.16, T=101, r=-0.14. We found no evidence of diurnal variability in cough reflex testing. There was, however, an order effect irrespective of time of day, confirming that healthy participants are able to volitionally modulate their cough response. Copyright © 2017 Elsevier B.V. All rights reserved.

  12. Influence of diurnal variations in stream temperature on streamflow loss and groundwater recharge

    Science.gov (United States)

    Constantz, Jim; Thomas, Carole L.; Zellweger, Gary W.

    1994-01-01

    We demonstrate that for losing reaches with significant diurnal variations in stream temperature, the effect of stream temperature on streambed seepage is a major factor contributing to reduced afternoon streamflows. An explanation is based on the effect of stream temperature on the hydraulic conductivity of the streambed, which can be expected to double in the 0° to 25°C temperature range. Results are presented for field experiments in which stream discharge and temperature were continuously measured for several days over losing reaches at St. Kevin Gulch, Colorado, and Tijeras Arroyo, New Mexico. At St. Kevin Gulch in July 1991, the diurnal stream temperature in the 160-m study reach ranged from about 4° to 18°C, discharges ranged from 10 to 18 L/s, and streamflow loss in the study reach ranged from 2.7 to 3.7 L/s. On the basis of measured stream temperature variations, the predicted change in conductivity was about 38%; the measured change in stream loss was about 26%, suggesting that streambed temperature varied less than the stream temperature. At Tijeras Arroyo in May 1992, diurnal stream temperature in the 655-m study reach ranged from about 10° to 25°C and discharge ranged from 25 to 55 L/s. Streamflow loss was converted to infiltration rates by factoring in the changing stream reach surface area and streamflow losses due to evaporation rates as measured in a hemispherical evaporation chamber. Infiltration rates ranged from about 0.7 to 2.0 m/d, depending on time and location. Based on measured stream temperature variations, the predicted change in conductivity was 29%; the measured change in infiltration was also about 27%. This suggests that high infiltration rates cause rapid convection of heat to the streambed. Evapotranspiration losses were estimated for the reach and adjacent flood plain within the arroyo. On the basis of these estimates, only about 5% of flow loss was consumed via stream evaporation and stream-side evapotranspiration

  13. Diurnal variation of the serum leptin concentration in patients with anorexia nervosa

    DEFF Research Database (Denmark)

    Støving, R K; Vinten, J; Handberg, A

    1998-01-01

    , however, this has been reported to be absent in normal weighted amenorrheic athletes. Anorexia nervosa is associated with multiple endocrine abnormalities. Hypothalamic amenorrhoea often precedes the weight loss and may persist after weight recovery. We hypothesized that leptin could be involved...... in the regulation of eating behaviour and gonadal function in anorexia nervosa. DESIGN: We measured the concentration of leptin in serum samples taken after an overnight fast in 18 female anorexia nervosa patients and 11 controls. To study diurnal variation, eight patients and 11 controls were hospitalized for 24 h...... and had a standardized diet at regular times. Seven blood samples were obtained at 4 h intervals from each subject. PATIENTS: The patients fulfilled the DSM-IV criteria for anorexia nervosa. The mean body mass index for the patients was 14.2 +/- 2.3 kg/m2 and for controls 20.3 +/- 1.7 kg/m2. RESULTS...

  14. Diurnal variation of vascular diameter and reactivity in healthy young men

    Directory of Open Access Journals (Sweden)

    P.F.D. Bau

    2008-06-01

    Full Text Available The higher incidence of cardiovascular events in the morning is accompanied by an increased vascular tone. However, there are few published studies designed to evaluate the diurnal variation of vascular and endothelial parameters in healthy subjects. In the present investigation, we evaluated the diurnal variation in brachial artery diameter (BAD, flow-mediated dilation (FMD and endothelium-independent dilation (NFMD in a homogeneous sample of healthy non-smoker young men. Fifty subjects aged 20.8 ± 0.3 years (range: 18 to 25 years were investigated by brachial artery ultrasound. Exclusion criteria were female gender and evidence of clinically significant health problems, including obesity. Volunteers were asked to rest and avoid fat meals as well as alcoholic beverages 48 h before and until completion of the evaluations. BAD, FMD and NFMD were measured at 7 am, 5 pm, and 10 pm and tested by repeated measures ANOVA. BAD was smaller at 7 am (mean ± SEM, 3.8 ± 0.1 mm in comparison with 5 pm (3.9 ± 0.1 and 10 pm (4.0 ± 0.1 mm; P < 0.001. FMD values did not change significantly during the day, while NFMD increased more at 7 am (18.5 ± 1.1%, when compared to 15.5 ± 0.9% at 10 pm and 15.5 ± 0.9% at 5 pm (P = 0.04. The physiological state of vasoconstriction after awakening, with preserved capability to dilate in the morning, should be considered to be part of the healthy cardiovascular adaptation before considering later life risk factors and endothelial dysfunction.

  15. Diurnal variation in the biliary excretion of flomoxef in patients with percutaneous transhepatic biliary drainage.

    Science.gov (United States)

    Hishikawa, S; Kobayashi, E; Sugimoto , K; Miyata, M; Fujimura, A

    2001-07-01

    To examine diurnal variation in biliary excretion of flomoxef. Flomoxef (1 g) was injected intravenously in eight patients with percutaneous transhepatic cholangiography with drainage at 09.00 h and 21.00 h by a cross-over design with a 36 h washout period. Drained biliary fluid was collected for 6 h after each dosing. These patients still had mild to moderate hepatic dysfunction. Bile flow and bile acid excretion for 6 h after dosing did not differ significantly between the 09.00 h and 21.00 h treatments. The maximum concentration of biliary flomoxef was significantly greater and its total excretion for 6 h tended to be greater after the 21.00 h dose [maximum concentration (microg ml(-1)): 34.2 +/- 29.9 (09.00 h dose) vs 43.5 +/- 28.3 (21.00 h dose) (95% confidence interval for difference: 2.6 approximately 15.9, P = 0.013); total excretion (mg 6 h(-1)): 1.4 +/- 1.3 (09.00 h dose) vs 1.6 +/- 1.2 (21.00 h dose) (95% confidence interval for difference: -26.8, 313.7, P = 0.087)]. The period that biliary flomoxef remained above the minimal inhibitory concentration did not differ significantly between the two treatment times. These results suggest that biliary excretion of flomoxef shows diurnal variation. However, as the difference was relatively small, flomoxef could be given at any time of day without any dosage adjustments.

  16. Physiological and Molecular Response of Ostrich to the Seasonal and Diurnal Variations in Egyptian conditions

    International Nuclear Information System (INIS)

    Khalil, M.H.; Khalifa, H.H; Elaroussi, M.A.; Elsayed, M.A.; Basuony, H.A.

    2013-01-01

    Twelve immature ostrich›s birds, 7 months old were used to evaluate the effect of ambient temperature variation and diurnal effect on response changes of some physiological and chemical parameters. All birds were reared out doors and exposed to daily ambient temperatures fluctuations during summer and winter. Blood samples were taken twice, one in the morning at 7 Am and once in the afternoon at 3 Pm during a representative 7 hot days of June (summer) (40±2ºC) and the 7 cold days of January (winter) (18±2ºC). Serum calcium, inorganic phosphorus, sodium, potassium, uric acid concentrations and aldosterone level were determined. The amount of total body water (TBW) and serum heat shock proteins (HSP) were estimated. Serum calcium, phosphorus, sodium and potassium concentrations in ostrich were significantly decreased, while uric acid concentration and aldosterone hormone level were significantly increased in summer as compared in winter during both at morning and at afternoon periods. Concerning the diurnal variation, serum calcium, phosphorus, sodium and potassium concentrations and aldosterone hormone level in ostrich were significantly increased, while uric acid concentration was significantly decreased at morning as compared at afternoon during both summer and winter seasons. TBW was significantly higher in summer season by 15.04% than winter season. It is concluded from the present study that heat or cold stress has a negative effect on most of the parameters studied and we recommend must be supplement diet with some nutrients like vitamins C, and E, sodium bicarbonate or yeast to overcome the negative effect and to better perform under such conditions

  17. Diurnal Variation In Behaviour Of Pink-Footed Geese (Anser Brachyrhynchus) During Spring Migration In Trøndelag, Norway

    DEFF Research Database (Denmark)

    Chudzińska, Magda Ewa; Madsen, Jesper; Nabe-Nielsen, Jacob

    During spring migration, Pink-footed Geese Anser brachyrhynchus stop in mid Norway to refuel before their onward flight to the Svalbard breeding grounds. In mid Norway, geese feed on pastures, stubble as well as newly sown grain fields. The aim of the paper is to describe diurnal variations...... in the behaviour of geese and to examine whether these variations are driven by digestibility of food geese feed on or also by external factors such as distance to the roost, disturbance and flock size. Based on diurnal flock scans of activity budgets (observations carried out between 05h00 and 22h00 hrs) in each...... habitat type, we fitted a model containing all predictors we believe may influence geese behaviour. The number of feeding and alert geese on fields displayed a strong diurnal trend, which varied among habitat types, frequent and sporadic disturbance, but not flock size. On roost sites, geese also showed...

  18. Diurnal Variations of Equilibrium Factor and Unattached fraction of Radon Progeny in Some Houses and Laboratories

    International Nuclear Information System (INIS)

    Lee, Seung Chan; Kang, Hee Dong; Kim, Chang Kyu; Lee, Dong Myung

    2001-01-01

    The variation characteristics of radon concentration, equilibrium equivalent concentration and equilibrium factor in some house and laboratory buildings have been studied. The variation of equilibrium factor and the unattached fraction of radon progeny with ventilation condition have been also estimated. The averages of radon concentration, equilibrium equivalent concentration and equilibrium factor were 30 Bq m -3 , 19.6 Bq m -3 and 0.65 in seven houses, while 55.0 Bq m -3 , 31.9 Bq m -3 and 0.58 in three laboratory buildings, respectively. The diurnal variation of radon concentration, equilibrium equivalent concentration and equilibrium factor in indoor showed a typical pattern that the radon concentration, equilibrium equivalent concentration and equilibrium factor increased at dawn and morning, while decreased at midday and evening. While the equilibrium factor rate deceased in the indoor environment which was well ventilated, the unattached fraction of radon progeny increased. The equilibrium factor was in proportion to air pressure and humidity of indoor, whereas in inverse proportion to temperature

  19. Effect of diurnal variation, CYP2B6 genotype and age on the pharmacokinetics of nevirapine in African children

    NARCIS (Netherlands)

    Bienczak, A.; Cook, A.; Wiesner, L.; Mulenga, V.; Kityo, C.; Kekitiinwa, A.; Walker, A.S.; Owen, A.; Gibb, D.M.; Burger, D.M.; McIlleron, H.; Denti, P.

    2017-01-01

    OBJECTIVES: To characterize the effects of CYP2B6 polymorphisms, diurnal variation and demographic factors on nevirapine pharmacokinetics in African children. METHODS: Non-linear mixed-effects modelling conducted in NONMEM 7.3 described nevirapine plasma concentration-time data from 414 children

  20. RELATIONSHIP OF AIRWAY HYPERRESPONSIVENESS TO RESPIRATORY SYMPTOMS AND DIURNAL PEAK FLOW VARIATION IN PATIENTS WITH OBSTRUCTIVE LUNG-DISEASE

    NARCIS (Netherlands)

    BRAND, PLP; POSTMA, DS; KERSTJENS, HAM; KOETER, GH

    This study reports on the relationship of airway hyperresponsiveness (AH) with respiratory symptoms and diurnal peak flow expiratory (PEF) variation in 221 hyperresponsive patients with moderately severe airways obstruction. The disease was in a stable phase in all patients. Closely adhering to the

  1. Diurnal variation in the performance of rapid response systems: the role of critical care services-a review article.

    Science.gov (United States)

    Sundararajan, Krishnaswamy; Flabouris, Arthas; Thompson, Campbell

    2016-01-01

    The type of medical review before an adverse event influences patient outcome. Delays in the up-transfer of patients requiring intensive care are associated with higher mortality rates. Timely detection and response to a deteriorating patient constitute an important function of the rapid response system (RRS). The activation of the RRS for at-risk patients constitutes the system's afferent limb. Afferent limb failure (ALF), an important performance measure of rapid response systems, constitutes a failure to activate a rapid response team (RRT) despite criteria for calling an RRT. There are diurnal variations in hospital staffing levels, the performance of rapid response systems and patient outcomes. Fewer ward-based nursing staff at night may contribute to ALF. The diurnal variability in RRS activity is greater in unmonitored units than it is in monitored units for events that should result in a call for an RRT. RRT events include a significant abnormality in either the pulse rate, blood pressure, conscious state or respiratory rate. There is also diurnal variation in RRT summoning rates, with most activations occurring during the day. The reasons for this variation are mostly speculative, but the failure of the afferent limb of RRT activation, particularly at night, may be a factor. The term "circadian variation/rhythm" applies to physiological variations over a 24-h cycle. In contrast, diurnal variation applies more accurately to extrinsic systems. Circadian rhythm has been demonstrated in a multitude of bodily functions and disease states. For example, there is an association between disrupted circadian rhythms and abnormal vital parameters such as anomalous blood pressure, irregular pulse rate, aberrant endothelial function, myocardial infarction, stroke, sleep-disordered breathing and its long-term consequences of hypertension, heart failure and cognitive impairment. Therefore, diurnal variation in patient outcomes may be extrinsic, and more easily modifiable

  2. Diurnal variation in ruminal pH on the digestibility of highly digestible perennial ryegrass during continuous culture fermentation.

    Science.gov (United States)

    Wales, W J; Kolver, E S; Thorne, P L; Egan, A R

    2004-06-01

    Dairy cows grazing high-digestibility pastures exhibit pronounced diurnal variation in ruminal pH, with pH being below values considered optimal for digestion. Using a dual-flow continuous culture system, the hypothesis that minimizing diurnal variation in pH would improve digestion of pasture when pH was low, but not at a higher pH, was tested. Four treatments were imposed, with pH either allowed to exhibit normal diurnal variation around an average pH of 6.1 or 5.6, or maintained at constant pH. Digesta samples were collected during the last 3 d of each of four, 9-d experimental periods. A constant pH at 5.6 compared with a constant pH of 6.1 reduced the digestibility of organic matter (OM), neutral detergent (NDF), and acid detergent fiber (ADF) by 7, 14, and 21%, respectively. When pH was allowed to vary (averaging 5.6), digestion of OM, NDF, and ADF were reduced by 15,30, and 36%, respectively, compared with pH varying at 6.1. There was little difference in digestion parameters when pH was either constant or varied with an average pH of 6.1. However, when average pH was 5.6, maintaining a constant pH significantly increased digestion of OM, NDF, and ADF by 5, 25, and 24% compared with a pH that exhibited normal diurnal variation. These in vitro results show that gains in digestibility and potential milk production can be made by minimizing diurnal variation in ruminal pH, but only when ruminal pH is low (5.6). However, larger gains in productivity can be achieved by increasing average daily ruminal pH from 5.6 to 6.1.

  3. Influence of ocean tides on the diurnal and semidiurnal earth rotation variations from VLBI observations

    Science.gov (United States)

    Gubanov, V. S.; Kurdubov, S. L.

    2015-05-01

    The International astrogeodetic standard IERS Conventions (2010) contains a model of the diurnal and semidiurnal variations in Earth rotation parameters (ERPs), the pole coordinates and the Universal Time, arising from lunisolar tides in the world ocean. This model was constructed in the mid-1990s through a global analysis of Topex/Poseidon altimetry. The goal of this study is to try to estimate the parameters of this model by processing all the available VLBI observations on a global network of stations over the last 35 years performed within the framework of IVS (International VLBI Service) geodetic programs. The complexity of the problemlies in the fact that the sought-for corrections to the parameters of this model lie within 1 mm and, thus, are at the limit of their detectability by all currently available methods of ground-based positional measurements. This requires applying universal software packages with a high accuracy of reduction calculations and a well-developed system of controlling the simultaneous adjustment of observational data to analyze long series of VLBI observations. This study has been performed with the QUASAR software package developed at the Institute of Applied Astronomy of the Russian Academy of Sciences. Although the results obtained, on the whole, confirm a high accuracy of the basic model in the IERS Conventions (2010), statistically significant corrections that allow this model to be refined have been detected for some harmonics of the ERP variations.

  4. Using mobile monitoring to visualise diurnal variation of traffic pollutants across two near-highway neighbourhoods

    Science.gov (United States)

    Pattinson, Woodrow; Longley, Ian; Kingham, Simon

    2014-09-01

    It is widely accepted that concentrations of primary traffic pollutants can vary substantially across relatively small urban areas. Fixed-site monitors have been shown to be largely inadequate for representing concentrations at nearby locations, resulting in the increasing use of spatial modelling or mobile sampling methods to achieve spatial saturation. In this study, we employ the use of a simple bicycle to sample concentrations of ultrafine particles (UFPs), carbon monoxide (CO) and particulate matter (PM10) at two small areas (arterials and quieter streets, at periods of contrasting meteorological and traffic conditions. A total of 20 sampling runs in each area (five at each of the four timings) were conducted. Meteorological data were logged continuously at background sites within each study area. Results show that the influence of highway traffic (UFPs, CO) was strongest during the mornings and late evenings when wind speeds were low, while for the midday and afternoon timings, concentrations were highest at the arterial and shopping zones. Concentrations of PM10 appeared to be strongest in the residential areas during mornings and late evenings, suggesting an influence of wood burning for home heating. For all timings combined, for all three pollutants, it appears the arterial roads featuring shops and numerous intersections with traffic lights, had a stronger influence on concentrations than the busier but more free-flowing highways. This study provides not only an insight into microspatial hotspot variation across suburbs, but also how this variation shifts diurnally.

  5. Autoradiographic investigations on the question of diurnal variations of cell proliferation in the jejunal crypt epithelia of mice

    International Nuclear Information System (INIS)

    Herterich, G.C.

    1982-01-01

    In this work the question was investigated whether the proliferation activity of the crypt epithelia of the small intestine of mice is subject to diurnal variations. The results published so far to settle this question are contradictory. The flow rate at the beginning and end of the S phase was measured as a function of daytime for the jejunal crypt epithelia of mice following a double labelling with 3-H and 14-C-TdR. The quotient of the cell flow rate in and out of the S phase is supposed to be = 1 over the whole day if there are no diurnal variations. The method of measurements of the cell flow rate was chosen above all because the quotient is largely independent of the variation from animal to animal. The experiments provided dues as to the presence of deviations of the quotient of cell flow rate at the end and beginning of the S phase and of the mitotic index from the daily mean value. However, on account of the relatively large statistical variations of the values at the different daytimes it is not possible to state clearly whether the cell proliferation of the jejunal epithelium is subject to diurnal variations. Should there be such variations, then they are not large at any rate. (orig./MG) [de

  6. Daily positive events and diurnal cortisol rhythms: Examination of between-person differences and within-person variation.

    Science.gov (United States)

    Sin, Nancy L; Ong, Anthony D; Stawski, Robert S; Almeida, David M

    2017-09-01

    Growing evidence from field studies has linked daily stressors to dysregulated patterns of diurnal cortisol. Less is known about whether naturally-occurring positive events in everyday life are associated with diurnal cortisol. The objectives of this study were to evaluate daily positive events as predictors of between-person differences and within-person (day-to-day) variations in diurnal cortisol parameters, in addition to daily positive events as buffers against the associations between daily stressors and cortisol. In the National Study of Daily Experiences, 1657 adults ages 33-84 (57% female) reported daily experiences during telephone interviews on 8 consecutive evenings. Saliva samples were collected 4 times per day on 4 interview days and assayed for cortisol. Multilevel models were used to estimate associations of daily positive events with cortisol awakening response (CAR), diurnal cortisol slope, and area under the curve (AUC). At the between-person level, people who experienced more frequent positive events exhibited a steeper diurnal cortisol slope, controlling for daily stressors, daily affect, and other covariates. At the within-person level, positive events in the morning (but not prior-night or afternoon/evening events) predicted steeper decline in cortisol across that day; positive events were also marginally associated with lower same-day AUC. Associations were not mediated by daily positive affect, and positive events did not buffer against stressor-related cortisol alterations. These findings indicate that individual differences and day-to-day variations in daily positive events are associated with diurnal cortisol patterns, independent of stressors and affect. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Diurnal variation and reliability of the urine lactate concentration after maximal exercise.

    Science.gov (United States)

    Nikolaidis, Stefanos; Kosmidis, Ioannis; Sougioultzis, Michail; Kabasakalis, Athanasios; Mougios, Vassilis

    2018-01-01

    The postexercise urine lactate concentration is a novel valid exercise biomarker, which has exhibited satisfactory reliability in the morning hours under controlled water intake. The aim of the present study was to investigate the diurnal variation of the postexercise urine lactate concentration and its reliability in the afternoon hours. Thirty-two healthy children (11 boys and 21 girls) and 23 adults (13 men and 10 women) participated in the study. All participants performed two identical sessions of eight 25 m bouts of maximal freestyle swimming executed every 2 min with passive recovery in between. These sessions were performed in the morning and afternoon and were separated by 3-4 days. Adults performed an additional afternoon session that was also separated by 3-4 days. All swimmers drank 500 mL of water before and another 500 mL after each test. Capillary blood and urine samples were collected before and after each test for lactate determination. Urine creatinine, urine density and body water content were also measured. The intraclass correlation coefficient was used as a reliability index between the morning and afternoon tests, as well as between the afternoon test and retest. Swimming performance and body water content exhibited excellent reliability in both children and adults. The postexercise blood lactate concentration did not show diurnal variation, showing a good reliability between the morning and afternoon tests, as well as high reliability between the afternoon test and retest. The postexercise urine density and lactate concentration were affected by time of day. However, when lactate was normalized to creatinine, it exhibited excellent reliability in children and good-to-high reliability in adults. The postexercise urine lactate concentration showed high reliability between the afternoon test and retest, independent of creatinine normalization. The postexercise blood and urine lactate concentrations were significantly correlated in all

  8. Short-term cyclic variations and diurnal variations of the Venus upper atmosphere

    Science.gov (United States)

    Keating, G. M.; Taylor, F. W.; Nicholson, J. Y.; Hinson, E. W.

    1979-01-01

    The vertical structure of the nighttime thermosphere and exosphere of Venus was discussed. A comparison of the day and nighttime profiles indicates, contrary to the model of Dickinson and Riley (1977), that densities (principally atomic oxygen) dropped sharply from day to night. It was suggested either that the lower estimates were related to cooler exospheric temperatures at night or that the atomic bulge was flatter than expected at lower altitudes. Large periodic oscillations, in both density and inferred exospheric temperatures, were detected with periods of 5 to 6 days. The possibility that cyclic variations in the thermosphere and stratosphere were caused by planetary-scale waves, propagated upward from the lower atmosphere, was investigated using simultaneous temperature measurements obtained by the Venus radiometric temperature experiment (VORTEX). Inferred exospheric temperatures in the morning were found to be lower than in the evening as if the atmosphere rotated in the direction of the planet's rotation, similar to that of earth. Superrotation of the thermosphere and exosphere was discussed as a possible extension of the 4-day cyclic atmospheric rotation near the cloud tops.

  9. Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

    Directory of Open Access Journals (Sweden)

    Y. García-Orellana

    2013-01-01

    Full Text Available Field-grown lemon trees (Citrus limon (L. Burm. fil. cv. Fino were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS signal intensity (actual MDS/control treatment MDS threshold values of 1.25 (T1 treatment and 1.35 (T2 treatment, which induced two different drought stress levels. Daily variations in leaf (Yleaf and stem (Ystem water potentials, leaf conductance, net photosynthesis, sap flow (SF and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Yleaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Ystem was seen to be a better plant water status indicator than Yleaf. The difference between the two values of Y (Ystem - Yleaf  = DY was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees.

  10. Diurnal variation of on-road air pollution in an urban street canyon in Seoul

    Science.gov (United States)

    Ho, Woo, Sung; Lee, Seung-Bok; Kim, Kyung Hwan; Bae, Gwi-Nam; Sunwoo, Young; Ma, Young-Il; Han, Dokyoung; Song, Sanghoo

    2014-05-01

    Motor vehicles are a major source of CO, NOx and particulate matters. Especially, in the surroundings of high-raised buildings, so-called an urban street canyon, air pollution levels increase due to limited dispersion of vehicle emissions. In this study, a mobile laboratory was used to measure diurnal variation of on-road concentrations of air pollutants such as NOx, particle-bound polycyclic aromatic hydrocarbons, black carbon and particle number in the urban street canyon on the Teheran road with eight lanes in Seoul, Korea from 5th to 8th November 2013. Each traveling distance was about 3.3km. Traveling vehicle at the middle of the Teheran road was recorded by video camera, and then the car counting by vehicle types. On road measurements conducted for 3~6 hours per day. Hourly average of air pollutant concentration in morning rush hour more than two times higher than those at the daybreak. We will analyze the correlation between air pollution levels and traffic volume by vehicle types. We will discuss about spatial characteristics of on-road air pollution levels in the urban street canyon.

  11. Sewer infiltration/inflow: long-term monitoring based on diurnal variation of pollutant mass flux.

    Science.gov (United States)

    Bares, V; Stránský, D; Sýkora, P

    2009-01-01

    The paper deals with a method for quantification of infiltrating groundwater based on the variation of diurnal pollutant load and continuous water quality and quantity monitoring. Although the method gives us the potential to separate particular components of wastewater hygrograph, several aspects of the method should be discussed. Therefore, the paper investigates the cost-effectiveness, the relevance of pollutant load from surface waters (groundwater) and the influence of measurement time step. These aspects were studied in an experimental catchment of Prague sewer system, Czech Republic, within a three-month period. The results indicate high contribution of parasitic waters on night minimal discharge. Taking into account the uncertainty of the results and time-consuming maintenance of the sensor, the principal advantages of the method are evaluated. The study introduces a promising potential of the discussed measuring concept for quantification of groundwater infiltrating into the sewer system. It is shown that the conventional approach is sufficient and cost-effective even in those catchments, where significant contribution of foul sewage in night minima would have been assumed.

  12. Real world vehicle fleet emission factors: Seasonal and diurnal variations in traffic related air pollutants

    Science.gov (United States)

    Wang, Jonathan M.; Jeong, Cheol-Heon; Zimmerman, Naomi; Healy, Robert M.; Evans, Greg J.

    2018-07-01

    Temporal variations of vehicle emissions are affected by various compounding factors in the real world. The focus of this study is to determine the effects of ambient conditions and post-tailpipe changes on traffic emissions measured in the near-road region. Emission factors allowed for the isolation of the traffic signal and accounted for effects of local meteorology and dilution. Five month-long measurement campaigns were conducted at an urban near-road site that exhibited a broad range of ambient conditions with temperatures ranging between -18 and +30 °C. Particle number emission factors were 2.0× higher in the winter relative to the summer, which was attributed to changes in particles post-tailpipe. Conversely, toluene emissions were 2.5× higher in the summer relative to the winter, attributed to changes in fuel composition. Diurnal trends of emission factors showed substantial increases in emissions during the morning rush hour for black carbon (1.9×), particle number (2.4×), and particle-bound polycyclic aromatic hydrocarbons (3.0×), affected by fleet make-up. In contrast, particle number emission factors were highest midday with mean values 3.7× higher than at night. This midday increase was attributed to particle formation or growth from local traffic emissions and showed different wind direction dependence than regional events.

  13. Diurnal variation of methane emission from a paddy field in Brazilian Southeast

    Directory of Open Access Journals (Sweden)

    Magda Aparecida de Lima

    2018-04-01

    Full Text Available ABSTRACT: This study aimed to investigate the diurnal variation of methane (CH4 emission in a flooded-irrigated rice field at different stages of the plant development under tropical climate in three growing seasons, in order to determine the most appropriate time for gas sampling in the Brazilian Southeast region. It aimed also to verify correlations between CH4 flux and air, water and soil temperatures, and solar radiation. The CH4 emissions were measured every 3-hour interval on specific days in different development stages of the flooded rice in the Experiment Station of the Agência Paulista de Tecnologia dos Agronegócios (APTA, Pólo Regional Vale do Paraíba, at Pindamonhangaba, State of São Paulo (22°55’ S, 45°30’ W, Brazil. Different CH4 emission rates were observed among the plant growth stages and also among the growing seasons. The CH4 emission showed high correlation with the soil temperature at 2cm depth. At this depth, the CH4 emission activation energy in response to soil temperature was higher in the stage R2. Emission peaks were observed at afternoon, while lower fluxes were recorded at the early morning. The most appropriate local time for gas sampling was estimated at 12:11:15a.m.±01:14:16 and 09:05:49p.m.±01:29:04.

  14. Monthly variations of diurnal rainfall in north coast of West Java Indonesia during boreal winter periods

    Science.gov (United States)

    Yulihastin, E.; Trismidianto

    2018-05-01

    Diurnal rainfall during the active monsoon period is usually associated with the highest convective activity that often triggers extreme rainfall. Investigating diurnal rainfall behavior in the north coast of West Java is important to recognize the behavioral trends of data leading to such extreme events in strategic West Java because the city of Jakarta is located in this region. Variability of diurnal rainfall during the period of active monsoon on December-January-February (DJF) composite during the 2000-2016 period was investigated using hourly rainfall data from Tropical Rainfall Measuring Mission (TRMM) 3B41RT dataset. Through the Empirical Mode Decomposition method was appears that the diurnal rain cycle during February has increased significantly in its amplitude and frequency. It is simultaneously shows that the indication of extreme rainfall events is related to diurnal rain divergences during February shown through phase shifts. The diurnal, semidiurnal, and terdiurnal cycles appear on the characteristics of the DJF composite rainfall data during the 2000-2016 period.The significant increases in amplitude occurred during February are the diurnal (IMF 3) and terdiurnal (IMF 1) of rainfall cycles.

  15. Seasonal and diurnal variation in concentrations of gaseous and particulate phase endosulfan

    Science.gov (United States)

    Li, Qingbo; Wang, Xianyu; Song, Jing; Sui, Hongqi; Huang, Lei; Li, Lu

    2012-12-01

    Successive 52-week air monitoring of α-endosulfan (α-E), β-endosulfan (β-E) and endosulfan sulfate (E.S) in the gaseous and particulate phases was conducted in Dalian city, northeast China by using an active high-volume sampler. Significant seasonal and diurnal variations in endosulfan concentrations were observed. It was found that the concentration of gaseous-phase α-E peaked in the summer and the concentration of particulate phase α-E peaked in the winter. For E.S, both gaseous and particulate phase concentrations peaked in the summer. α-E was distributed predominantly in the gas phase in the summer but was distributed mainly in the particulate phase in the winter. β-E was distributed mainly in the gas phase in the summer and in the particulate phase at other times of the year. E.S was distributed mainly in the particulate phase throughout the year. Elevated temperatures facilitated the volatilization of α-E from particle surfaces but exerted little effect on β-E and had almost no effect on E.S. Trajectory-based analysis indicates that the seasonal variation in atmospheric concentrations of endosulfan in Dalian city was influenced strongly by the land and sea air masses. In addition, differences in endosulfan concentrations in the particulate phase between day and night were likely due to the circulation of sea/land breezes. The 'cold-condensation' effect occurring during the night may result in the attachment of endosulfan to the particulate phase.

  16. Influence of diurnal variation and fasting on serum iron concentrations in a community-based population.

    Science.gov (United States)

    Nguyen, Leonard T; Buse, Joshua D; Baskin, Leland; Sadrzadeh, S M Hossein; Naugler, Christopher

    2017-12-01

    Serum iron is an important clinical test to help identify cases of iron deficiency or overload. Fluctuations caused by diurnal variation and diet are thought to influence test results, which may affect clinical patient management. We examined the impact of these preanalytical factors on iron concentrations in a large community-based cohort. Serum iron concentration, blood collection time, fasting duration, patient age and sex were obtained for community-based clinical testing from the Laboratory Information Service at Calgary Laboratory Services for the period of January 2011 to December 2015. A total of 276,307 individual test results were obtained. Iron levels were relatively high over a long period from 8:00 to 15:00. Mean concentrations were highest at blood collection times of 11:00 for adult men and 12:00 for adult women and children, however iron levels peaked as late as 15:00 in teenagers. With regard to fasting, iron levels required approximately 5h post-prandial time to return to a baseline, except for children and teenage females where no significant variation was seen until after 11h fasting. After 10h fasting, iron concentrations in all patient groups gradually increased to higher levels compared to earlier fasting times. Serum iron concentrations remain reasonably stable during most daytime hours for testing purposes. In adults, blood collection after 5 to 9h fasting provides a representative estimate of a patient's iron levels. For patients who have fasted overnight, i.e. ≥12h fasting, clinicians should be aware that iron concentrations may be elevated beyond otherwise usual levels. Copyright © 2017. Published by Elsevier Inc.

  17. Phthalate metabolites in Norwegian mothers and children: Levels, diurnal variation and use of personal care products.

    Science.gov (United States)

    Sakhi, Amrit Kaur; Sabaredzovic, Azemira; Cequier, Enrique; Thomsen, Cathrine

    2017-12-01

    Exposure to phthalates has been associated with reproductive and developmental toxicity. Data on levels of these compounds in the Norwegian population is limited. In this study, urine samples were collected from 48 mothers and their children in two counties in Norway. Eleven different phthalate metabolites originating from six commonly used phthalates in consumer products were determined. Concentrations of phthalate metabolites were significantly higher in children compared to mothers except for mono-ethyl phthalate (MEP). The mothers provided several urine samples during 24hours (h) and diurnal variation showed that the concentrations in the morning urine samples (24-8h) were significantly higher than at other time-periods for most of the phthalate metabolites. Intraclass correlation coefficients (ICCs) for 24-hour time-period were in the range of 0.49-0.81. These moderate to high ICCs indicate that one spot urine sample can be used to estimate the exposure to phthalates. Since a significant effect of time of day was observed, it is still advisable to standardize the collection time point to reduce the variation. For the mothers, the use of personal care products (PCPs) were less associated with morning urine samples than early day (8-12h) and evening (16-24h) urine samples. The use of perfume and hair products were positively associated with the urinary concentrations of low molecular weight phthalates. Use of shower soap and shampoo were positively associated with urinary concentration of di(2-ethylhexyl) phthalate (DEHP) metabolites. For children, face cream use was positively associated with phthalate metabolites in the morning samples, and hand soap use was negatively associated with concentration of urinary DEHP metabolites in afternoon/evening samples. Since different PCPs were associated with the urinary phthalate metabolites in different time-periods during a day, more than one spot urine sample might be required to study associations between urinary

  18. Effect of posture on the diurnal variation in clinically significant diabetic macular edema.

    Science.gov (United States)

    Polito, Antonio; Polini, Giovanni; Chiodini, Raffaella Gortana; Isola, Miriam; Soldano, Franca; Bandello, Francesco

    2007-07-01

    To investigate the role of posture and other systemic factors in the diurnal variation of clinically significant diabetic macular edema (CSDME). Ten eyes of 10 diabetic subjects with CSDME underwent four OCT foveal thickness measurements with StratusOCT at 9 AM and 12, 3, and 6 PM consecutively on two different days, with the subject in an upright position on one and in a recumbent position on the other. For the "recumbent-position" measurements, the patients were admitted the night before and remained in bed during the entire day of testing. Clinical laboratory results at baseline included HbA1c, urinary albumin, and serum creatinine. Refraction and Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity were also measured before each OCT measurement was taken. Variations in blood pressure, body temperature, plasma glucose, renin, aldosterone, and cortisol levels were measured and then correlated with macular thickness. Foveal thickening decreased in all cases over the course of the day. The decrease, however, was significantly greater for the upright-position measurements (relative mean +/- SD decrease of 20.6% +/- 6.5% in the upright position and 6.2% +/- 4.6% in the recumbent position). Visual acuity improved by at least 1 ETDRS line in three eyes in the upright position as opposed to only one eye in the recumbent position. There seemed to be no association between any of the systemic factors studied and foveal thickening, with the exception of cortisol. The results support the hypothesis that posture and hydrostatic pressure play a major role in determining time-related shifts in CSDME and suggest that the forces of Starling's law can in part, account for CSDME formation.

  19. Segmental Quantitative MR Imaging analysis of diurnal variation of water content in the lumbar intervertebral discs

    International Nuclear Information System (INIS)

    Zhu, Ting Ting; Ai, Tao; Zhang, Wei; Li, Tao; Li, Xiao Ming

    2015-01-01

    To investigate the changes in water content in the lumbar intervertebral discs by quantitative T2 MR imaging in the morning after bed rest and evening after a diurnal load. Twenty healthy volunteers were separately examined in the morning after bed rest and in the evening after finishing daily work. T2-mapping images were obtained and analyzed. An equally-sized rectangular region of interest (ROI) was manually placed in both, the anterior and the posterior annulus fibrosus (AF), in the outermost 20% of the disc. Three ROIs were placed in the space defined as the nucleus pulposus (NP). Repeated-measures analysis of variance and paired 2-tailed t tests were used for statistical analysis, with p < 0.05 as significantly different. T2 values significantly decreased from morning to evening, in the NP (anterior NP = -13.9 ms; central NP = -17.0 ms; posterior NP = -13.3 ms; all p < 0.001). Meanwhile T2 values significantly increased in the anterior AF (+2.9 ms; p = 0.025) and the posterior AF (+5.9 ms; p < 0.001). T2 values in the posterior AF showed the largest degree of variation among the 5 ROIs, but there was no statistical significance (p = 0.414). Discs with initially low T2 values in the center NP showed a smaller degree of variation in the anterior NP and in the central NP, than in discs with initially high T2 values in the center NP (10.0% vs. 16.1%, p = 0.037; 6.4% vs. 16.1%, p = 0.006, respectively). Segmental quantitative T2 MRI provides valuable insights into physiological aspects of normal discs.

  20. [Spatial variation in diurnal courses of stem temperature of Betula platyphylla and Fraxinus mandshurica and its influencing factors].

    Science.gov (United States)

    Li, Yu Ran; Wang, Xing Chang; Wang, Chuan Kuan; Liu, Fan; Zhang, Quan Zhi

    2017-10-01

    Plant temperature is an important parameter for estimating energy balance and vegetation respiration of forest ecosystem. To examine spatial variation in diurnal courses of stem temperatures (T s ) and its influencing factors, we measured the T s with copper constantan thermocouples at different depths, heights and azimuths within the stems of two broadleaved tree species with contrasting bark and wood properties, Betula platyphylla and Fraxinus mandshurica. The results showed that the monthly mean diurnal courses of the T s largely followed that of air temperature with a 'sinusoi dal' pattern, but the T s lagged behind the air temperature by 0 h at the stem surface to 4 h at 6 cm depth. The daily maximal values and ranges of the diurnal course of T s decreased gradually with increasing measuring depth across the stem and decreasing measuring height along the stem. The circumferential variation in T s was marginal, with slightly higher daily maximal values in the south and west directions during the daytime of the dormant season. Differences in thermal properties (i.e. , specific heat capacity and thermal conductivity) of both bark and wood tissue between the two species contributed to the inter specific variations in the radial variation in T s through influencing the heat exchange between the stem surface and ambient air as well as heat diffusion within the stem. The higher reflectance of the bark of B. platyphylla decreased the influence of solar radiation on T s . The stepwise regression showed that the diurnal courses of T s could be well predicted by the environmental factors (R 2 > 0.85) with an order of influence ranking as air temperature > water vapor pressure > net radiation > wind speed. It is necessary to take the radial, vertical and inter specific varia-tions in T s into account when estimating biomass heat storage and stem CO2 efflux.

  1. Diurnal variations of summertime precipitation over the Tibetan Plateau in relation to orographically-induced regional circulations

    International Nuclear Information System (INIS)

    Liu Xiaodong; Bai Aijuan; Liu Changhai

    2009-01-01

    The diurnal patterns of variation of summertime precipitation over the Tibetan Plateau were first investigated using the TRMM multi-satellite precipitation analysis product for five summer seasons (i.e. June to August for 2002-2006). Both hourly precipitation amount and precipitation frequency exhibit pronounced daily variability with an overall late-afternoon-evening maximum and a dominant morning minimum. A notable exception is the prevalent nocturnal maximum around the periphery of the Plateau. In terms of the normalized harmonic amplitude, the diurnal signal shows significant regional contrast with the strongest manifestation over the central Plateau and the weakest near the periphery. This remarkable spatial dependence in daily rainfall cycles is clear evidence of orographic and heterogeneous land-surface impacts on convective development. Using six-hourly NCEP FNL data, we then examined the diurnal variability in the atmospheric circulation and thermodynamics in this region. The results show that the Plateau heats (cools) the overlying atmosphere during the day (night) more than the surrounding areas, and as a consequence a relatively stronger confluent circulation in this region occurs during the day than during the night, consistent with the diurnal rainfall cycles. Moreover, the regions with large low-level convergence and upper-level divergence correspond to the strong diurnal rainfall variations. The reversed daily alterations of convergence-divergence patterns in the vicinity of the Plateau edges are in agreement with the observed nighttime rainfall peak therein. This study further demonstrates the importance of the Tibetan Plateau in regulating regional circulation and precipitation.

  2. Ranges of diurnal variation and the pattern of body temperature, blood pressure and heart rate in laboratory beagle dogs.

    Science.gov (United States)

    Miyazaki, Hiroyasu; Yoshida, Mutsumi; Samura, Keiji; Matsumoto, Hiroyoshi; Ikemoto, Fumihiko; Tagawa, Masahiro

    2002-01-01

    Ranges in diurnal variation and the patterns of body temperature (T), blood pressure (BP), heart rate (HR) and locomotor activity (LA) in 61 laboratory beagle dogs were analyzed using a telemetry system. Body temperature, BP, HR and LA increased remarkably at feeding time. Locomotor activity increased sporadically during the other periods. Body temperature was maintained at the higher value after feeding but had decreased by 0.2 C by early the next morning. Blood pressure fell to a lower value after feeding but had increased by 2.8% by early the next morning. Heart rate decreased progressively after feeding and was 14.5% lower the next morning. This study determined that in laboratory beagles the ranges of diurnal variation and patterns of T, BP and HR are significantly different from those reported in humans and rodents, and that over 24 hr these physiological changes were associated with their sporadic wake-sleep cycles of the dogs.

  3. Impact of land convection on temperature diurnal variation in the tropical lower stratosphere inferred from COSMIC GPS radio occultations

    Directory of Open Access Journals (Sweden)

    S. M. Khaykin

    2013-07-01

    Full Text Available Following recent studies evidencing the influence of deep convection on the chemical composition and thermal structure of the tropical lower stratosphere, we explore its impact on the temperature diurnal variation in the upper troposphere and lower stratosphere using the high-resolution COSMIC GPS radio-occultation temperature measurements spanning from 2006 through 2011. The temperature in the lowermost stratosphere over land during summer displays a marked diurnal cycle characterized by an afternoon cooling. This diurnal cycle is shown collocated with most intense land convective areas observed by the Tropical Rainfall Measurement Mission (TRMM precipitation radar and in phase with the maximum overshooting occurrence frequency in late afternoon. Two processes potentially responsible for that are identified: (i non-migrating tides, whose physical nature is internal gravity waves, and (ii local cross-tropopause mass transport of adiabatically cooled air by overshooting turrets. Although both processes can contribute, only the lofting of adiabatically cooled air is well captured by models, making it difficult to characterize the contribution of non-migrating tides. The impact of deep convection on the temperature diurnal cycle is found larger in the southern tropics, suggesting more vigorous convection over clean rain forest continents than desert areas and polluted continents in the northern tropics.

  4. Cosmic Ray Daily Variation And SOLAR Activity On Anomalous Days

    International Nuclear Information System (INIS)

    Mishra, Rajesh Kumar; Mishra, Rekha Agarwal

    2008-01-01

    A study is carried out on the long-term changes in the diurnal anisotropy of cosmic rays using the ground based Deep River neutron monitor data during significantly low amplitude anisotropic wave train events in cosmic ray intensity for the period 1981-94. It has been observed that the phase of the diurnal anisotropy for majority of the low amplitude anisotropic wave train events significantly shifts towards earlier hours as compared to the co-rotational direction. The long-term behaviour of the amplitude of the diurnal anisotropy can be explained in terms of the occurrence of low amplitude anisotropic wave train events. The occurrence of these events is dominant during solar activity minimum years. The amplitude of the diurnal anisotropy is well correlated with the solar cycle but the direction of the anisotropy is not correlated with the solar cycle and shows a systematic shift to earlier hours. (authors)

  5. Atmospheric Structure and Diurnal Variations at Low Altitudes in the Martian Tropics

    Science.gov (United States)

    Hinson, David P.; Spiga, A.; Lewis, S.; Tellmann, S.; Pätzold, M.; Asmar, S.; Häusler, B.

    2013-10-01

    We are using radio occultation measurements from Mars Express, Mars Reconnaissance Orbiter, and Mars Global Surveyor to characterize the diurnal cycle in the lowest scale height above the surface. We focus on northern spring and summer, using observations from 4 Martian years at local times of 4-5 and 15-17 h. We supplement the observations with results obtained from large-eddy simulations and through data assimilation by the UK spectral version of the LMD Mars Global Circulation Model. We previously investigated the depth of the daytime convective boundary layer (CBL) and its variations with surface elevation and surface properties. We are now examining unusual aspects of the temperature structure observed at night. Most important, predawn profiles in the Tharsis region contain an unexpected layer of neutral static stability at pressures of 200-300 Pa with a depth of 4-5 km. The mixed layer is bounded above by a midlevel temperature inversion and below by another strong inversion adjacent to the surface. The narrow temperature minimum at the base of the midlevel inversion suggests the presence of a water ice cloud layer, with the further implication that radiative cooling at cloud level can induce convective activity at lower altitudes. Conversely, nighttime profiles in Amazonis show no sign of a midlevel inversion or a detached mixed layer. These regional variations in the nighttime temperature structure appear to arise in part from large-scale variations in topography, which have several notable effects. First, the CBL is much deeper in the Tharsis region than in Amazonis, owing to a roughly 6-km difference in surface elevation. Second, large-eddy simulations show that daytime convection is not only deeper above Tharsis but also considerably more intense than it is in Amazonis. Finally, the daytime surface temperatures are comparable in the two regions, so that Tharsis acts as an elevated heat source throughout the CBL. These topographic effects are expected to

  6. Diurnal Variations of Emissions of O2 singlet Delta Near Mars' Northern Summer Solstice

    Science.gov (United States)

    Nosowitz, Jonathon; Ziobron, Elijah; Novak, Robert E.

    2017-10-01

    We are presenting results of O2 singlet Delta emission, a tracer for ozone, in the Martian atmosphere for observations taken before Mars’ Northern summer solstice (Ls = 88o, February 10, 2014 ). The data were taken using CSHELL on the NASA-IRTF telescope located on Mauna Kea in Hawaii. The slit was positioned east-west on Mars and we observed diurnal variations at 20o N and 60o N. Spectral/spatial images were taken with a spectral resolution above 38,000. Mars’ relative velocity of -16 km/s enabled us to separate the Martian emission lines from the telluric absorption lines. Raw images were cleaned by removing dead and hot pixels. The images were then adjusted so that the spatial dimension was perpendicular to the spectral dimension. Extracts at 0.6 arcsec spatial resolution were taken which allowed us to measure Martian emission peaks. The Martian data were calibrated by taking similar observations from a standard star (HR4689) using the temperature, wavelength, and intensity of the star to calibrate the flux density. A Boltzmann analysis was performed on the observed emission peaks to obtain the rotational temperature of the excited O2. From this, the total emission rates were obtained. We found that at both latitudinal locations, the greatest emissions occured between 12:00- 13:00 local time on Mars. The emission intensity increases during the morning hours and then decreases towards sunset. We thank the administration and staff of the NASA-IRTF for observation time and for their assistance during operations of the telescope. We also thank Drs. M. Mumma and G. Villanueva of the NASA Goddard Space Flight Center with whom we collaborate.

  7. Diurnal variations in water relations of deficit irrigated lemon trees during fruit growth period

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Orellana, Y.; Ortuno, M. F.; Conejero, W.; Ruiz-Sanchez, M. C.

    2013-05-01

    Field-grown lemon trees (Citrus limon (L.) Burm. fil. cv. Fino) were subjected to different drip irrigation treatments: a control treatment, irrigated daily above crop water requirements in order to obtain non-limiting soil water conditions and two deficit irrigation treatments, reducing the water applied according to the maximum daily trunk shrinkage (MDS) signal intensity (actual MDS/control treatment MDS) threshold values of 1.25 (T1 treatment) and 1.35 (T2 treatment), which induced two different drought stress levels. Daily variations in leaf (Y{sub l}eaf) and stem (Y{sub s}tem) water potentials, leaf conductance, net photosynthesis, sap flow (SF) and trunk diameter fluctuations were studied on four occasions during the lemon fruit growth period. Ystem and Y{sub l}eaf revealed a diurnal pattern in response to changes in evaporative demand of the atmosphere. Both water potentials decreased in response to water deficits, which were more pronounced in the T2 treatment. Y{sub s}tem was seen to be a better plant water status indicator than Y{sub l}eaf. The difference between the two values of Y (Y{sub s}tem - Y{sub l}eaf {Delta}{Psi}) was closely correlated with sap flow, making it a suitable measure of leaf transpiration. Using the slope of this relationship, the canopy hydraulic conductance (KC) was estimated. When other continuously recorded plant-based indicators are not accessible, the concurrent measurement of leaf and stem water potentials at midday, which are relatively inexpensive to measure and user-friendly, act as sufficiently good indicators of the plant water status in field grown Fino lemon trees. (Author) 40 refs.

  8. Seasonal and diurnal variation of organic ultraviolet filters from personal care products used along the Japanese coast.

    Science.gov (United States)

    Sankoda, Kenshi; Murata, Kotaro; Tanihata, Mai; Suzuki, Kengo; Nomiyama, Kei; Shinohara, Ryota

    2015-02-01

    This study aimed to investigate the behavior of organic ultraviolet (UV) filters released by recreational activities along the Japanese coastline. Seasonal variations of organic UV filters in seawater were investigated at four different recreational beaches (Mogushi, Wakamiya, Tsurugahama, and Otachimisaki beaches) in both summer (July through August) and winter (December). Moreover, short time scale diurnal changes were monitored at Otachimisaki beach in summer. Of the four sunscreen agents tested in this study, two agents-2-ethylhexyl-4-methoxycinnamate (EHMC) and 2-ethylhexyl salicylate (EHS)-were detected in all samples, whereas octyl-dimethyl-p-aminobenzonic acid and 3-(4-methylbenzylidene)-camphor were lower than detection limits. In particular, EHMC, one of the most popular organic UV filters, was dominant. The highest concentration of EHMC was observed at 1,080 ng L(-1), a level that exceeds those of previous studies. Both EHMC and EHS concentrations showed significant (p < 0.05) seasonal variations with advancing summer suggesting direct input from recreational activities. The subsequent examination showed short time scale diurnal changes of organic UV filters on the beach. The results showed that diurnal changes in EHMC concentrations were correlated to the number of bathers. EHMC concentrations increased during the afternoon and decreased during the night, although complete attenuation during the night did not occur. EHMC persists along the coast due to low mobility and may persist the next day. This is the first study to show the natural attenuation behavior of organic UV filters along recreational beaches.

  9. Diurnal sampling reveals significant variation in CO2 emission from a tropical productive lake.

    Science.gov (United States)

    Reis, P C J; Barbosa, F A R

    2014-08-01

    It is well accepted in the literature that lakes are generally net heterotrophic and supersaturated with CO2 because they receive allochthonous carbon inputs. However, autotrophy and CO2 undersaturation may happen for at least part of the time, especially in productive lakes. Since diurnal scale is particularly important to tropical lakes dynamics, we evaluated diurnal changes in pCO2 and CO2 flux across the air-water interface in a tropical productive lake in southeastern Brazil (Lake Carioca) over two consecutive days. Both pCO2 and CO2 flux were significantly different between day (9:00 to 17:00) and night (21:00 to 5:00) confirming the importance of this scale for CO2 dynamics in tropical lakes. Net heterotrophy and CO2 outgassing from the lake were registered only at night, while significant CO2 emission did not happen during the day. Dissolved oxygen concentration and temperature trends over the diurnal cycle indicated the dependence of CO2 dynamics on lake metabolism (respiration and photosynthesis). This study indicates the importance of considering the diurnal scale when examining CO2 emissions from tropical lakes.

  10. Seasonal Variation of Diurnal Cycle of Rainfall in the Eastern Equatorial Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    RameshKumar, M.R.; Pednekar, S.; Katsumata, M.; Antony, M.K.; Kuroda, Y.; Unnikrishnan, A.S.

    The diurnal cycle of rainfall over the eastern equatorial Indian Ocean is studied for the period 23rd October 2001 to 31st October 2003 using the hourly data from the Triton buoy positioned at 1.5°S and 90°E. An analysis of the active and weak...

  11. Global evaluation of ammonia bidirectional exchange and livestock diurnal variation schemes

    Science.gov (United States)

    Bidirectional air–surface exchange of ammonia (NH3) has been neglected in many air quality models. In this study, we implement the bidirectional exchange of NH3 in the GEOS-Chem global chemical transport model. We also introduce an updated diurnal variability scheme for NH3...

  12. The diurnal variation in urine acidification differs between normal individuals and uric acid stone formers

    Science.gov (United States)

    Cameron, Mary Ann; Maalouf, Naim M.; Poindexter, John; Adams-Huet, Beverley; Sakhaee, Khashayar; Moe, Orson W.

    2012-01-01

    Many biologic functions follow circadian rhythms driven by internal and external cues that synchronize and coordinate organ physiology to diurnal changes in the environment and behavior. Urinary acid-base parameters follow diurnal patterns and it is thought these changes are due to periodic surges in gastric acid secretion. Abnormal urine pH is a risk factor for specific types of nephrolithiasis and uric acid stones are typical of excessively low urine pH. Here we placed 9 healthy volunteers and 10 uric acid stone formers on fixed metabolic diets to study the diurnal pattern of urinary acidification. All showed clear diurnal trends in urinary acidification but none of the patterns were affected by inhibitors of the gastric proton pump. Uric acid stone formers had similar patterns of change through the day but their urine pH was always lower compared to healthy volunteers. Uric acid stone formers excreted more acid (normalized to acid ingestion) with the excess excreted primarily as titratable acid rather than ammonium. Urine base excretion was also lower in uric acid stone formers (normalized to base ingestion) along with lower plasma bicarbonate concentrations during part of the day. Thus, increased net acid presentation to the kidney and the preferential use of buffers, other than ammonium, result in much higher concentrations of un-dissociated uric acid throughout the day and consequently an increased risk of uric acid stones. PMID:22297671

  13. Diurnal and Intra-Annual Variations in Greenhouse Gases at Fixed Sites in the San Francisco Bay Area

    Science.gov (United States)

    Newman, S.; Guha, A.; Martien, P. T.; Bower, J.; Perkins, I.; Randall, S.; Young, A.; Stevenson, E.; Hilken, H.

    2017-12-01

    The Bay Area Air Quality Management District, the San Francisco Bay Area's air quality regulatory agency, has set a goal to reduce the region's greenhouse gas (GHG) emissions to 80% below 1990 levels by 2050, consistent with the State of California's climate goals. Recently, the Air District's governing board adopted a 2017 Clean Air Plan which lays out the agency's vision and includes actions to put the region on a path towards achieving the 2050 goal while also reducing air pollution and related health impacts. The Plan includes GHG rule-making efforts, policy initiatives, local government partnerships, outreach, grants, and incentives, encompassing over 250 specific implementation actions across all economic sectors to effect ambitious emission reductions in the region. To track trends in atmospheric observations of GHGs and associated species and monitor changes in regional emission patterns, the Air District has established a fixed site network (CO2, CH4, CO) of one generally upwind site (Bodega Bay - on the coast north of Marin County) and three receptor sites (Bethel Island - east of the major refineries, in the Sacramento River Delta; Livermore - east of the bulk of the East Bay cities; and San Martin - south of the major city of San Jose). Having collected over a year of data for each of the fixed sites, the Air District is now investigating spatial and temporal variations in GHG emissions. Concentrating on variations in diurnal cycles, we see the commonly observed pattern of seasonal changes in diurnal amplitude at all sites, with larger variations during the winter than the summer, consistent with seasonally varying daily changes in planetary boundary layer heights. Investigations explore the weekday/weekend effect on the diurnal patterns and the effect of seasonal wind direction changes on the intra-annual variations of the local enhancements. The Air District is beginning to investigate the ways in which the fixed site network reflects the dominant

  14. Real T1 relaxation time measurement and diurnal variation analysis of intervertebral discs in a healthy population of 50 volunteers

    International Nuclear Information System (INIS)

    Galley, J.; Maestretti, G.; Koch, G.; Hoogewoud, H-M.

    2017-01-01

    Purpose: To measure the real T1 relaxation time of the lumbar intervertebral discs in a young and healthy population, using different inversion recovery times, and assess diurnal variation. Material and methods: Intervertebral discs from D12 to S1 of 50 healthy volunteers from 18 to 25 years old were evaluated twice the same day, in the morning and in the late afternoon. Dedicated MRI sequences with different inversion recovery times (from 100 to 2500 ms) were used to calculate the real T1 relaxation time. Three regions of interest (ROIs) were defined in each disc, the middle representing the nucleus pulposus (NP) and the outer parts the annulus fibrosus (AF) anterior and posterior. Diurnal variation and differences between each disc level were analyzed. Results: T1 mean values in the NP were 1142 ± 12 ms in the morning and 1085 ± 13 ms in the afternoon, showing a highly significant decrease of 57 ms (p < 0.001). A highly significant difference between the levels of the spine was found. The mean T1 of the anterior part of the AF was 577 ± 9 ms in the morning and 554 ± 8 ms in the afternoon. For the posterior part, the mean values were 633 ± 8 ms in the morning and 581 ± 7 ms in the evening. It shows a highly significant decrease of 23 ms for the anterior part and 51 ms for the posterior part (all p < 0.001). Conclusion: T1 mapping is a promising method of intervertebral disc evaluation. Significant diurnal variation and difference between levels of the lumbar spine were demonstrated. A potential use for longitudinal study in post-operative follow up or sport medicine needs to be evaluated.

  15. Real T1 relaxation time measurement and diurnal variation analysis of intervertebral discs in a healthy population of 50 volunteers

    Energy Technology Data Exchange (ETDEWEB)

    Galley, J., E-mail: galleyjulien@gmail.com [Department of Radiology, HFR Fribourg, Hôpital Cantonal (Switzerland); Maestretti, G. [Department of Orthopedic Surgery, HFR Fribourg, Hôpital Cantonal (Switzerland); Koch, G.; Hoogewoud, H-M. [Department of Radiology, HFR Fribourg, Hôpital Cantonal (Switzerland)

    2017-02-15

    Purpose: To measure the real T1 relaxation time of the lumbar intervertebral discs in a young and healthy population, using different inversion recovery times, and assess diurnal variation. Material and methods: Intervertebral discs from D12 to S1 of 50 healthy volunteers from 18 to 25 years old were evaluated twice the same day, in the morning and in the late afternoon. Dedicated MRI sequences with different inversion recovery times (from 100 to 2500 ms) were used to calculate the real T1 relaxation time. Three regions of interest (ROIs) were defined in each disc, the middle representing the nucleus pulposus (NP) and the outer parts the annulus fibrosus (AF) anterior and posterior. Diurnal variation and differences between each disc level were analyzed. Results: T1 mean values in the NP were 1142 ± 12 ms in the morning and 1085 ± 13 ms in the afternoon, showing a highly significant decrease of 57 ms (p < 0.001). A highly significant difference between the levels of the spine was found. The mean T1 of the anterior part of the AF was 577 ± 9 ms in the morning and 554 ± 8 ms in the afternoon. For the posterior part, the mean values were 633 ± 8 ms in the morning and 581 ± 7 ms in the evening. It shows a highly significant decrease of 23 ms for the anterior part and 51 ms for the posterior part (all p < 0.001). Conclusion: T1 mapping is a promising method of intervertebral disc evaluation. Significant diurnal variation and difference between levels of the lumbar spine were demonstrated. A potential use for longitudinal study in post-operative follow up or sport medicine needs to be evaluated.

  16. Seasonal, Diurnal, and Solar-Cycle Variations of Electron Density at Two West Africa Equatorial Ionization Anomaly Stations

    Directory of Open Access Journals (Sweden)

    Frédéric Ouattara

    2012-01-01

    Full Text Available We analyse the variability of foF2 at two West Africa equatorial ionization anomaly stations (Ouagadougou and Dakar during three solar cycles (from cycle 20 to cycle 22, that is, from 1966 to 1998 for Ouagadougou and from 1971 to 1997 for Dakar. We examine the effect of the changing levels of solar extreme ultraviolet radiation with sunspot number. The study shows high correlation between foF2 and sunspot number (Rz. The correlation coefficient decreases from cycle 20 to cycle 21 at both stations. From cycle 21 to cycle 22 it decreases at Ouagadougou station and increases at Dakar station. The best correlation coefficient, 0.990, is obtained for Dakar station during solar cycle 22. The seasonal variation displays equinoctial peaks that are asymmetric between March and September. The percentage deviations of monthly average data from one solar cycle to another display variability with respect to solar cycle phase and show solar ultraviolet radiation variability with solar cycle phase. The diurnal variation shows a noon bite out with a predominant late-afternoon peak except during the maximum phase of the solar cycle. The diurnal Ouagadougou station foF2 data do not show a significant difference between the increasing and decreasing cycle phases, while Dakar station data do show it, particularly for cycle 21. The percentage deviations of diurnal variations from solar-minimum conditions show more ionosphere during solar cycle 21 at both stations for all three of the other phases of the solar cycle. There is no significant variability of ionosphere during increasing and decreasing solar cycle phases at Ouagadougou station, but at Dakar station there is a significant variability of ionosphere during these two solar-cycle phases.

  17. Diurnal Variations in Serum Glucose, Insulin and C-Peptide of Normal Korean Adults

    International Nuclear Information System (INIS)

    Choi, Du Hyok; Chung, June Key; Lee, Hong Kyu; Koh, Chang Soon; Hong, Kee Suk

    1983-01-01

    It is already well known that many factors are involved in maintaining normal blood glucose level. The amount and components of meal are also thought to be some of the factors which affect the blood glucose and insulin levels. It is reported that as for Koreans sugar takes up over 75% out of 2,098 kcal, the average daily calorie intake per adult. It implies that Koreans take a high-sugar diet compared with Westerners who take 40-50% of sugar out of their total average daily calorie. For the purpose of studying diurnal variations in serum glucose, insulin and C-peptide of normal Koreans adults based on ordinary Korean diet, we selected 13 normal Korean male adults and divided them into two groups, Group I (7 persons) and Group II (6 persons). We put Group I on 3,100 kcal and 75% sugar diet, and Group II on 2,100 kcal and 69% sugar diet per day for over 4 days. Serum glucose, insulin and C-peptide were checked every 30 minutes or every hour throughout 2 hour. Results are as follows: 1. As for serum glucose level, in the preprandial fasting state in the morning, mean±S.D. of Group I was 91.1±3.2 mg%, while that of Group II is 82.5±4.4 mg%. Both groups showed peaks of increased glucose level t postprandial 1 hour after each meal. The peak returned to the level shown during the fasting state at postprandial 1 hour after breakfast while the relatively high glucose levels were maintained respectively even for 2 or 3 hours after lunch and dinner. 2. As for serum insults level, Group I showed mean±S.D. of 14.7±3.0 μU/ml while Group II shows that of 7.0±2.6 μU/ml in the fasting state. Group I particularly showed the largest peak from preprandial a half or one and half an hour to postprandial one hour of lunch, and made relatively small peaks (47.7±10.8 μU/ml) at postprandial 1 hour after breakfast and dinner. No such large peak was marked in Group II, though it showed relatively similar patterns of peak after each meal. 3. As for C-peptide, in the fasting state

  18. Diurnal Variations in Serum Glucose, Insulin and C-Peptide of Normal Korean Adults

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Du Hyok; Chung, June Key; Lee, Hong Kyu; Koh, Chang Soon [Seoul National University College of Medicine, Seoul (Korea, Republic of); Hong, Kee Suk [Korea Cancer Center Hospital, Seoul (Korea, Republic of)

    1983-03-15

    It is already well known that many factors are involved in maintaining normal blood glucose level. The amount and components of meal are also thought to be some of the factors which affect the blood glucose and insulin levels. It is reported that as for Koreans sugar takes up over 75% out of 2,098 kcal, the average daily calorie intake per adult. It implies that Koreans take a high-sugar diet compared with Westerners who take 40-50% of sugar out of their total average daily calorie. For the purpose of studying diurnal variations in serum glucose, insulin and C-peptide of normal Koreans adults based on ordinary Korean diet, we selected 13 normal Korean male adults and divided them into two groups, Group I (7 persons) and Group II (6 persons). We put Group I on 3,100 kcal and 75% sugar diet, and Group II on 2,100 kcal and 69% sugar diet per day for over 4 days. Serum glucose, insulin and C-peptide were checked every 30 minutes or every hour throughout 2 hour. Results are as follows: 1. As for serum glucose level, in the preprandial fasting state in the morning, mean+-S.D. of Group I was 91.1+-3.2 mg%, while that of Group II is 82.5+-4.4 mg%. Both groups showed peaks of increased glucose level t postprandial 1 hour after each meal. The peak returned to the level shown during the fasting state at postprandial 1 hour after breakfast while the relatively high glucose levels were maintained respectively even for 2 or 3 hours after lunch and dinner. 2. As for serum insults level, Group I showed mean+-S.D. of 14.7+-3.0 muU/ml while Group II shows that of 7.0+-2.6 muU/ml in the fasting state. Group I particularly showed the largest peak from preprandial a half or one and half an hour to postprandial one hour of lunch, and made relatively small peaks (47.7+-10.8 muU/ml) at postprandial 1 hour after breakfast and dinner. No such large peak was marked in Group II, though it showed relatively similar patterns of peak after each meal. 3. As for C-peptide, in the fasting state

  19. Periodic and recurrent variations of cosmic rays

    International Nuclear Information System (INIS)

    Somogyi, A.J.

    1981-12-01

    The new results achieved in the field of periodic and recurrent variations of the intensity of 10 9 to 10 13 eV cosmic rays are reviewed. Particular emphasis is given to developments in understanding the fluctuations of corotation-type anisotropies as well as to the structure of the heliosphere and its temporal changes. (author)

  20. Diurnal variation, vertical distribution and source apportionment of carcinogenic polycyclic aromatic hydrocarbons (PAHs) in Chiang-Mai, Thailand.

    Science.gov (United States)

    Pongpiachan, Siwatt

    2013-01-01

    Diurnal variation of particulate polycyclic aromatic hydrocarbons (PAHs) was investigated by collecting PM10 at three different sampling altitudes using high buildings in the city center of Chiang-Mai, Thailand, during the relatively cold period in late February 2008. At site-1 (12 m above ground level), B[a]P concentrations ranged from 30.3 -1,673 pg m-3 with an average of 506±477 pg m-3, contributing on average, 8.09±8.69% to ?PAHs. Ind and B[b]F concentrations varied from 54.6 to 4,579 pg m-3 and from 80.7 to 2,292 pg m-3 with the highest average of 1,187±1,058 pg m-3 and 963±656 pg m-3, contributing on average, 19.0±19.3% and 15.4±12.0% to ?PAHs, respectively. Morning maxima were predominantly detected in all observatory sites, which can be described by typical diurnal variations of traffic flow in Chiang-Mai City, showing a morning peak between 6 AM. and 9 AM. Despite the fact that most monitoring sites might be subjected to specific-site impacts, it could be seen that PAH profiles in Site-1 and Site-2 were astonishingly homogeneous. The lack of differences suggests that the source signatures of several PAHs become less distinct possibly due to the impacts of traffic and cooking emissions from ground level.

  1. A study of diurnal variation in peak expiratory flow rates in healthy adult female subjects in South India

    Directory of Open Access Journals (Sweden)

    Jenny Jayapal

    2014-01-01

    Full Text Available Background: Peak Expiratory Flow Rate (PEFR reflects the strength and condition of respiratory muscles and the degree of airflow limitation in large airways. PEFR shows hour to hour variation that follows a specific pattern in asthmatics and healthy individuals. Adequate data is not available for the diurnal variation in normal individuals who are students in professional courses and had a sedentary life style. Hence, this study was undertaken to study the diurnal variation in peak expiratory flow rates in healthy adult female subjects in South India. Materials and Methods: Peak expiratory flow rate was recorded in 50 adult healthy female students aged 18-23 years and studying in professional courses. Mini Wright′s peak flow meter was used to measure the peak expiratory flow rate. PEFR were recorded at 7-8 a.m., 10-11 a.m., 1-2 p.m., 4-5 p.m., and 7-8 p.m. for two consecutive days. Results: On analysis of PEFR records of individual subjects, it was seen that there was an overall dip in the morning at 7-8 h PEFR, which increased in the daytime, peaking in the afternoon at 1-2 p.m. and eventually decreased in the night. Subjects did not show the peak PEFR values at the same time point, 10% of subjects had a rise in PEFR in the early morning, afternoon (1-2 p.m. peak was observed in 48% subjects and evening (4-5 p.m. peak was observed in 16% subjects. 14% subjects showed a peak in the night time (7-8 p.m. PEFR values. Conclusion: This study provided the preliminary reference data of diurnal variation of peak expiratory flow rate in healthy adults. Since, there is a variation in the peak expiratory flow rate recorded during different time points of the day; hence, to compare the PEFR between individuals it is advisable to record the PEFR at the same time point.

  2. Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

    Science.gov (United States)

    Zhang, Lei; Sun, Rui; Xu, Ziwei; Qiao, Chen; Jiang, Guoqing

    2015-01-01

    Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP), Ecosystem Respiration (Reco) and Net Ecosystem Exchange (NEE) were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR) on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different species. Nighttime

  3. Diurnal and seasonal variations of greenhouse gas emissions from a naturally ventilated dairy barn in a cold region

    Science.gov (United States)

    Huang, Dandan; Guo, Huiqing

    2018-01-01

    Carbon dioxide (CO2), methane (CH4), and nitrous oxide (N2O) emissions were quantified for a naturally ventilated free-stall dairy barn in the Canadian Prairies climate through continuous measurements for a year from February 2015 to January 2016, with ventilation rate estimated by a CO2 mass balance method. The results were categorized into seasonal emission profiles with monthly data measured on a typical day, and diurnal profiles in cold (January), warm (July), and mild seasons (October) of all three gases. Seasonal CO2, CH4, and N2O concentrations greatly fluctuated within ranges of 593-2433 ppm, 15-152 ppm, and 0.32-0.40 ppm, respectively, with obviously higher concentrations in the cold season. Emission factors of the three gases were summarized: seasonal N2O emission varied between 0.5 and 10 μg s-1 AU-1 with lower emission in the cold season, while seasonal CO2 and CH4 emissions were within narrow ranges of 112-119 mg s-1 AU-1 and 2.5-3.5 mg s-1 AU-1. The result suggested a lower enteric CH4 emission for dairy cows than that estimated by Environment Canada (2014). Significant diurnal effects (P 0.05), but obvious diurnal variations in all seasons. In comparison with previous studies, it was found that the dairy barn in a cold region climate with smaller vent openings had relatively higher indoor CO2 and CH4 concentrations, but comparable CO2 and CH4 emissions to most previous studies. Besides, ventilation rate, temperature, and relative humidity all significantly affected the three gas concentrations with the outdoor temperature being the most relevant factor (P < 0.01); however, they showed less or no statistical relations to emissions.

  4. Circadian variation of melatonin, light exposure, and diurnal preference in day and night shift workers of both sexes.

    Science.gov (United States)

    Papantoniou, Kyriaki; Pozo, Oscar J; Espinosa, Ana; Marcos, Josep; Castaño-Vinyals, Gemma; Basagaña, Xavier; Ribas, Ferran Calduch; Mirabent, Joan; Martín, Jordi; Carenys, Gemma; Martín, Celia Reyes; Middleton, Benita; Skene, Debra J; Kogevinas, Manolis

    2014-07-01

    Light-at-night has been shown in experimental studies to disrupt melatonin production but this has only partly been confirmed in studies of night shift workers. In this cross-sectional study, we examined the circadian variation of melatonin in relation to shift status, individual levels of light-at-night exposure, and diurnal preference, an attribute reflecting personal preference for activity in the morning or evening. One hundred and seventeen workers (75 night and 42 day) of both sexes, ages 22 to 64 years, were recruited from four companies. Participants collected urine samples from all voids over 24 hours and wore a data logger continuously recording their light exposure. Sociodemographic, occupational, lifestyle, and diurnal preference information were collected by interview. Concentrations of urinary 6-sulfatoxymelatonin (aMT6s), the main melatonin metabolite, were measured. Mean aMT6s levels were lower in night [10.9 ng/mg creatinine/hour; 95% confidence interval (CI), 9.5-12.6] compared with day workers (15.4; 95% CI, 12.3-19.3). The lowest aMT6s levels were observed in night workers with morning preference (6.4; 95% CI, 3.0-13.6). Peak time of aMT6s production occurred 3 hours later in night (08:42 hour, 95% CI, 07:48-09:42) compared with day workers (05:36 hour, 95% CI, 05:06-06:12). Phase delay was stronger among subjects with higher light-at-night exposure and number of nights worked. Night shift workers had lower levels and a delay in peak time of aMT6s production over a 24-hour period. Differences were modified by diurnal preference and intensity of light-at-night exposure. Night shift work affects levels and timing of melatonin production and both parameters may relate to future cancer risk. ©2014 American Association for Cancer Research.

  5. Effects of light on NO3 uptake in small forested streams: diurnal and day-to-day variations

    Energy Technology Data Exchange (ETDEWEB)

    Mulholland, Patrick J [ORNL

    2006-08-01

    We investigated the effects of autotrophy on short-term variations in nutrient dynamics by measuring diurnal and day-to-day variations in light level, primary productivity, and NO{sub 3}{sup -} uptake during early and late spring in 2 forested streams, the East and West Forks of Walker Branch in eastern Tennessee, USA. We predicted that diurnal and day-to-day variations in NO{sub 3}{sup -} uptake rate would be larger in the West Fork than in the East Fork in early spring because of higher rates of primary productivity resulting from a more stable substratum in the West Fork. We also predicted minimal diurnal variations in both streams in late spring after forest leaf emergence when light levels and primary productivity are uniformly low. Reach-scale rates of gross primary production (GPP) were determined using the diurnal dissolved O{sub 2} change technique, and reach-scale rates of NO{sub 3}{sup -} uptake were determined by tracer {sup 15}N-NO{sub 3}{sup -} additions. In the West Fork, significant diurnal and day-to-day variations in NO{sub 3}{sup -} uptake were related to variations in light level and primary productivity in early spring but not in late spring, consistent with our predictions. In early spring, West Fork NO{sub 3}{sup -} uptake rates were 2 to 3x higher at midday than during predawn hours and 50% higher on 2 clear days than on an overcast day several days earlier. In the East Fork, early spring rates of GPP were 4 to 5x lower than in the West Fork and diurnal and day-to-day variations in NO{sub 3}{sup -} uptake rates were <30%, considerably lower than in the West Fork. However, diurnal variations in NO{sub 3}{sup -} uptake rates were greater in late spring in the East Fork, possibly because of diurnal variation in water temperature. Our results indicate the important role of autotrophs in nutrient uptake in some forested streams, particularly during seasons when forest vegetation is dormant and light levels are relatively high. Our results also

  6. Diurnal variations in the outcomes of instrumented gait and quiet standing balance assessments and their association with falls history

    International Nuclear Information System (INIS)

    Doheny, Emer P; Greene, Barry R; Foran, Timothy; Cunningham, Clodagh; Fan, Chie Wei; Kenny, Rose Anne

    2012-01-01

    One in three adults aged over 65 falls every year, resulting in enormous costs to society. Incidents of falling vary with time of day, peaking in the early morning. The aim of this study was to determine if the ability of instrumented gait and balance assessments to discriminate between participants based on their falls history varies diurnally. Body-worn sensors were used during a 3 m gait assessment and a series of quiet standing balance tests. Each assessment was performed four times during a single day under supervised conditions in the participant's homes. 40 adults aged over 60 years (19 fallers) participated in this study. A range of parameters were derived for each assessment, and the ability of each parameter to discriminate between fallers and non-fallers at each recording time was examined. The effect of falls history on single support time varied significantly with recording time, with a significantly reduced single support time observed at the first and last recording session of the day. Differences were observed between fallers and non-fallers for a range of other gait parameters; however, these effects did not vary with assessment time. The quiet standing assessments examined in this study revealed significant variations with falls history; however, the sensitivity of the examined quiet standing assessments to falls risk does not appear to be time dependent. These results indicate that, with the exception of single support time, the association of gait and quiet standing balance parameters with falls risk does not vary diurnally. (paper)

  7. Using the Atmospheric Radiation Measurement (ARM) Datasets to Evaluate Climate Models in Simulating Diurnal and Seasonal Variations of Tropical Clouds

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Hailong [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Burleyson, Casey D. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Ma, Po-Lun [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Fast, Jerome D. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington; Rasch, Philip J. [Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, Washington

    2018-04-01

    We use the long-term Atmospheric Radiation Measurement (ARM) datasets collected at the three Tropical Western Pacific (TWP) sites as a tropical testbed to evaluate the ability of the Community Atmosphere Model (CAM5) to simulate the various types of clouds, their seasonal and diurnal variations, and their impact on surface radiation. We conducted a series of CAM5 simulations at various horizontal grid spacing (around 2°, 1°, 0.5°, and 0.25°) with meteorological constraints from reanalysis. Model biases in the seasonal cycle of cloudiness are found to be weakly dependent on model resolution. Positive biases (up to 20%) in the annual mean total cloud fraction appear mostly in stratiform ice clouds. Higher-resolution simulations do reduce the positive bias in the frequency of ice clouds, but they inadvertently increase the negative biases in convective clouds and low-level liquid clouds, leading to a positive bias in annual mean shortwave fluxes at the sites, as high as 65 W m-2 in the 0.25° simulation. Such resolution-dependent biases in clouds can adversely lead to biases in ambient thermodynamic properties and, in turn, feedback on clouds. Both the CAM5 model and ARM observations show distinct diurnal cycles in total, stratiform and convective cloud fractions; however, they are out-of-phase by 12 hours and the biases vary by site. Our results suggest that biases in deep convection affect the vertical distribution and diurnal cycle of stratiform clouds through the transport of vapor and/or the detrainment of liquid and ice. We also found that the modelled gridmean surface longwave fluxes are systematically larger than site measurements when the grid that the ARM sites reside in is partially covered by ocean. The modeled longwave fluxes at such sites also lack a discernable diurnal cycle because the ocean part of the grid is warmer and less sensitive to radiative heating/cooling compared to land. Higher spatial resolution is more helpful is this regard. Our

  8. Tidal and near-inertial peak variations around the diurnal critical latitude

    Science.gov (United States)

    van Haren, Hans

    2005-12-01

    Spectra from historic long-term open-ocean moored current meter data between latitudes 0° shift of the peak frequency to 0.97 +/- 0.01f, or a poleward spreading of enhanced energy. This contrasts with more common blue-shift. The enhancement may be the result of sub-harmonic instability, as supported by sparse significant bicoherence at half-D2, although i) systematic enhancement of diurnal tidal frequencies, notably M1, was not observed, ii) the latitudes of low D2-energy and high f-energy do not coincide. This may be due to a mix of coupled and independent waves, whilst the poleward trapping of sub-f energy suggests non-traditional effects.

  9. Simulation of the diurnal variations of the oxygen isotope anomaly (Δ17O of reactive atmospheric species

    Directory of Open Access Journals (Sweden)

    J. Savarino

    2011-04-01

    Full Text Available The isotope anomaly (Δ17O of secondary atmospheric species such as nitrate (NO3− or hydrogen peroxide (H2O2 has potential to provide useful constrains on their formation pathways. Indeed, the Δ17O of their precursors (NOx, HOx etc. differs and depends on their interactions with ozone, which is the main source of non-zero Δ17O in the atmosphere. Interpreting variations of Δ17O in secondary species requires an in-depth understanding of the Δ17O of their precursors taking into account non-linear chemical regimes operating under various environmental settings. This article reviews and illustrates a series of basic concepts relevant to the propagation of the Δ17O of ozone to other reactive or secondary atmospheric species within a photochemical box model. We present results from numerical simulations carried out using the atmospheric chemistry box model CAABA/MECCA to explicitly compute the diurnal variations of the isotope anomaly of short-lived species such as NOx and HOx. Using a simplified but realistic tropospheric gas-phase chemistry mechanism, Δ17O was propagated from ozone to other species (NO, NO2, OH, HO2, RO2, NO3, N2O5, HONO, HNO3, HNO4, H2O2 according to the mass-balance equations, through the implementation of various sets of hypotheses pertaining to the transfer of Δ17O during chemical reactions. The model results confirm that diurnal variations in Δ17O of NOx predicted by the photochemical steady-state relationship during the day match those from the explicit treatment, but not at night. Indeed, the Δ17O of NOx is "frozen" at night as soon as the photolytical lifetime of NOx drops below ca. 10 min. We introduce and quantify the diurnally-integrated isotopic signature (DIIS of sources of atmospheric nitrate and H2O2, which is of particular relevance to larger-scale simulations of Δ17O where high computational costs cannot be afforded.

  10. Diurnal variation in zooplankton in the Zuari Estuary, west coast of India

    Digital Repository Service at National Institute of Oceanography (India)

    Padmavati, G.; Goswami, S.C.; Vidya, P.S.

    Variations in zooplankton biomass and population density in relation to the prevailing hydrographical conditions were studied in Zuari Estuary, Goa. The physico-chemical parameters showed limited variations. Zooplankton biomass was relatively more...

  11. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosols of the urban area of Madrid

    International Nuclear Information System (INIS)

    Perez, M. M.; Perez-Pastor, R. M.; Bea, F. J.; Campos, A.; Gonzalez, D.

    1991-01-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)

  12. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosol of the urban area of Madrid

    International Nuclear Information System (INIS)

    Perez Garcia, M.M.; Perez Pastor, R.M.; Bea, J.F.; Campos, A.; Gonzalez Diaz, D.

    1990-01-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled in the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. From these results, it has been tried to identify emission sources of the studied hydrocarbons. (Author). 10 refs

  13. The Diurnal Variation of Hydrogen, Nitrogen, and Chlorine Radicals: Implications for the Heterogeneous Production of HNO2

    Science.gov (United States)

    Salawitch, R. J.; Wofsy, S. C.; Wennberg, P. O.; Cohen, R. C.; Anderson, J. G.; Fahey, D. W.; Gao, R. S.; Keim, E. R.; Woodbridge, E. L.; Stimpfle, R. M.; hide

    1994-01-01

    In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained through sunrise and sunset in the lower stratosphere during SPADE are compared to results from a photochemical model constrained by observed concentrations of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N205 on sulfate aerosols agree with measured concentrations of NO, NO2, and ClO throughout the day, but fail to account for high concentrations of OH and H02 observed near sunrise and sunset. The morning burst of [OH] and [HO2] coincides with the rise of [NO] from photolysis of N02, suggesting a new source of HO, that photolyzes in the near UV (350 to 400 nm) spectral region. A model that allows for the heterogeneous production of HN02 results in an excellent simulation of the diurnal variations of [OH] and [HO2].

  14. Seasonal and diurnal variations of particulate nitrate and organic matter at the IfT research station Melpitz

    Directory of Open Access Journals (Sweden)

    L. Poulain

    2011-12-01

    Full Text Available Ammonium nitrate and several organic compounds such as dicarboxylic acids (e.g. succinic acid, glutaric acid, some Polycyclic Aromatic Hydrocarbon (PAHs or some n-alkanes are semi-volatile. The transition of these compounds between the gas and particulate phase may significantly change the aerosol particles radiative properties, the heterogeneous chemical properties, and, naturally, the total particulate mass concentration. To better assess these time-dependent effects, three intensive field experiments were conducted in 2008–2009 at the Central European EMEP research station Melpitz (Germany using an Aerodyne Aerosol Mass Spectrometer (AMS. Data from all seasons highlight organic matter as being the most important particulate fraction of PM1 in summer (59% while in winter, the nitrate fraction was more prevalent (34.4%. The diurnal variation of nitrate always showed the lowest concentration during the day while its concentration increased during the night. This night increase of nitrate concentration was higher in winter (ΔNO3 = 3.6 μg m−3 than in summer (ΔNO3 = 0.7 μg m−3. The variation in particulate nitrate was inherently linked to the gas-to-particle-phase equilibrium of ammonium nitrate and the dynamics of the atmosphere during day. The results of this study suggest that during summer nights, the condensation of HNO3 and NH3 on pre-existing particles represents the most prevalent source of nitrate, whereas during winter, nighttime chemistry is the predominant source of nitrate. During the summer 2008's campaign, a clear diurnal evolution in the oxidation state of the organic matter became evident (Organic Mass to Organic Carbon ratio (OM/OC ranging from 1.65 during night to 1.80 during day and carbon oxidation state (OSc from −0.66 to −0.4, which could be correlated to hydroxyl radical (OH and ozone

  15. Seasonal and diurnal variations of Hg° over New England

    Directory of Open Access Journals (Sweden)

    J. D. Hegarty

    2008-03-01

    Full Text Available Factors influencing diurnal to interannual variability in Hg° over New England were investigated using multi-year measurements conducted by AIRMAP at the Thompson Farm (TF coastal site, an inland elevated site at Pac Monadnock (PM, and two month measurements on Appledore Island (AI in the Gulf of Maine. Mixing ratios of Hg° at TF showed distinct seasonality with maxima in March and minima in October. Hg° at AI tracked the trend at TF but with higher minima, while at PM the diurnal and annual cycles were dampened. In winter, Hg° was correlated most strongly with CO and NOy, indicative of anthropogenic emissions as their primary source. Our analysis indicates that Hg° had a regional background level of ~160 fmol/mol in winter, a dry deposition velocity of ~0.20 cm s−1 with a ~16 day lifetime in the coastal boundary layer in summer. The influence of oceanic emissions on ambient Hg° levels was identified using the Hg°-CHBr3 correlation at both TF and AI. Moreover, the lower Hg° levels and steeper decreasing warm season trend at TF (0.5–0.6 fmol/mol d−1 compared to PM (0.2–0.3 fmol/mol d−1 likely reflected the impact of marine halogen chemistry. Large interannual variability in warm season Hg° levels in 2004 versus 2005/2006 may be due to the role of precipitation patterns in influencing surface evasion of Hg°. In contrast, changes in wintertime maximum levels of Hg° were small compared to drastic reductions in CO, CO2, NOy, and SO2 from 2004/2005 to 2006/2007. These trends could be explained by a homogeneous distribution of Hg° over North American in winter due to its long lifetime and/or rapid removal of reactive mercury from anthropogenic sources. We caution that during warmer winters, the Hg°-CO slope possibly reflects Hg° loss relative to changes in CO more than their emission ratio.

  16. Seasonal variation in the range areas of the diurnal rodent Octodon degus.

    Science.gov (United States)

    Quirici, Verónica; Castro, Rodrigo A; Ortiz-Tolhuysen, Liliana; Chesh, Adrian S; Burger, Joseph Robert; Miranda, Eduardo; Cortés, Arturo; Hayes, Loren D; Ebensperger, Luis A

    2010-01-01

    Both breeding activity and abundance and quality of available food are expected to influence daily movements of animals. Animals are predicted to range over large areas to meet high energy demands associated with reproduction (females) or to increase mating success (males). However, animals should expand their range areas whenever food conditions deteriorate. To examine the extent to which breeding activity versus food availability influence space use, we compared the size and location of range areas (home ranges) of the degu (Octodon degus), a diurnal rodent from semiarid environments of north-central Chile, during the austral winter and summer seasons. Degus produce young during the austral spring (September-October) when high-quality food is readily available. In contrast, degus do not breed during the austral summer (January-March) when food is scarce and of low quality. We predicted that degus would range over smaller areas in winter if the availability of food has a greater influence on space than breeding activity. Individuals were radiotracked in winter and the following summer over a 3-year period. Surveys of herbaceous cover were conducted during winter and summer to determine seasonal changes in the abundance and quality of primary food. In summer degus expanded and moved the location of their range areas to locations with available food. Given that preferred food was less abundant in summer than winter, we suggest that degu range areas are strongly influenced by food conditions.

  17. Seasonal and diurnal variation in the deposition velocity of ozone over a spruce forest in Denmark

    DEFF Research Database (Denmark)

    Pilegaard, K.; Jensen, N.O.; Hummelshøj, P.

    1995-01-01

    The flux of O-3 was measured by the eddy-correlation method over Norway spruce in periods when the trees had a very low activity, periods with optimum growth, and periods with water stress. The aerodynamic resistance (tau(a)), viscous sub-layer resistance (tau(b)) and surface resistance (tau...... the activity of the trees was low. The surface resistance increased when the trees were subject to water stress. It is concluded that stomatal uptake is an important parameter for the deposition of O-3. However, other processes such as destruction of O-3 at surfaces, reaction with NO emitted from the soil......(c)) to O-3 were calculated from meteorological parameters and the deposition velocity. The canopy stomatal resistance to O-3 was calculated from measurements of the water vapour flux. The deposition velocities showed a diurnal pattern with night-time values of 3.5 mm s(-1) and day-time values of 7 mm s(-1...

  18. Effects of diurnal variations in temperature on non-accidental mortality among the elderly population of Montreal, Québec, 1984-2007.

    Science.gov (United States)

    Vutcovici, Maria; Goldberg, Mark S; Valois, Marie-France

    2014-07-01

    The association between ambient temperature and mortality has been studied extensively. Recent data suggest an independent role of diurnal temperature variations in increasing daily mortality. Elderly adults-a growing subgroup of the population in developed countries-may be more susceptible to the effects of temperature variations. The aim of this study was to determine whether variations in diurnal temperature were associated with daily non-accidental mortality among residents of Montreal, Québec, who were 65 years of age and over during the period between 1984 and 2007. We used distributed lag non-linear Poisson models constrained over a 30-day lag period, adjusted for temporal trends, mean daily temperature, and mean daily concentrations of nitrogen dioxide and ozone to estimate changes in daily mortality with diurnal temperature. We found, over the 30 day lag period, a cumulative increase in daily mortality of 5.12% [95% confidence interval (CI): 0.02-10.49%] for a change from 5.9 °C to 11.1 °C (25th to 75th percentiles) in diurnal temperature, and a 11.27% (95%CI: 2.08-21.29%) increase in mortality associated with an increase of diurnal temperature from 11.1 to 17.5 °C (75th to 99th percentiles). The results were relatively robust to adjustment for daily mean temperature. We found that, in Montreal, diurnal variations in temperature are associated with a small increase in non-accidental mortality among the elderly population. More studies are needed in different geographical locations to confirm this effect.

  19. Diurnal and seasonal variations in carbon dioxide exchange in ecosystems in the Zhangye oasis area, Northwest China.

    Directory of Open Access Journals (Sweden)

    Lei Zhang

    Full Text Available Quantifying carbon dioxide exchange and understanding the response of key environmental factors in various ecosystems are critical to understanding regional carbon budgets and ecosystem behaviors. For this study, CO2 fluxes were measured in a variety of ecosystems with an eddy covariance observation matrix between June 2012 and September 2012 in the Zhangye oasis area of Northwest China. The results show distinct diurnal variations in the CO2 fluxes in vegetable field, orchard, wetland, and maize cropland. Diurnal variations of CO2 fluxes were not obvious, and their values approached zero in the sandy desert, desert steppe, and Gobi ecosystems. Additionally, daily variations in the Gross Primary Production (GPP, Ecosystem Respiration (Reco and Net Ecosystem Exchange (NEE were not obvious in the sandy desert, desert steppe, and Gobi ecosystems. In contrast, the distributions of the GPP, Reco, and NEE show significant daily variations, that are closely related to the development of vegetation in the maize, wetland, orchard, and vegetable field ecosystems. All of the ecosystems are characterized by their carbon absorption during the observation period. The ability to absorb CO2 differed significantly among the tested ecosystems. We also used the Michaelis-Menten equation and exponential curve fitting methods to analyze the impact of Photosynthetically Active Radiation (PAR on the daytime CO2 flux and impact of air temperature on Reco at night. The results show that PAR is the dominant factor in controlling photosynthesis with limited solar radiation, and daytime CO2 assimilation increases rapidly with PAR. Additionally, the carbon assimilation rate was found to increase slowly with high solar radiation. The light response parameters changed with each growth stage for all of the vegetation types, and higher light response values were observed during months or stages when the plants grew quickly. Light saturation points are different for different

  20. Seasonal and diurnal variations of methane and carbon dioxide in the highly polluted Kathmandu Valley, Nepal

    Science.gov (United States)

    Mahata, Khadak; Panday, Arnico; Rupakheti, Maheswar; Lawrence, Mark

    2016-04-01

    Anthropogenic emissions of carbon dioxide and methane - key greenhouse gases (GHGs) - are primary causes of global warming and resultant impacts. The atmospheric warming is more pronounced and likely to cause more serious damage in vulnerable areas such as the Hindukush-Karakorum-Himalayan region (HKH). The HKH region is a data gap region according to the 5th Assessment report of the intergovernmental panel on climate change (IPCC). In order to understand the mixing ratios and variability of the key GHGs in the foothills of the Central Himalaya, we carried out continuous measurements of CO2, CH4, CO, and water vapor at Bode (an urban site in the Kathmandu valley, Nepal) for a year (March 2013 - Feb 2014), and again at Bode and at Chanban (a background outside the Valley) for 3 months (July 15 - Oct 3, 2015), with two state-of-the-art cavity ring-down instruments (Picarro G2401). The measurements were carried out as a part of the international air pollution measurement campaign: SusKat- ABC (Sustainable atmosphere for the Kathmandu Valley - Atmospheric Brown Clouds). The annual average CO2 and CH4 concentrations at Bode were 419 ± 24 and 2.192 ± 0.224 ppm, respectively, which are notably higher than those observed at the background site at Mauna Loa Observatory in the same period. The CO2concentration at Bode was high during the pre-monsoon period and low during the monsoon, while CH4 was high in winter and lower during the pre-monsoon period. The monthly CO2concentration was highest in April. Forest fires and agro-waste burning in the region, and the local emissions in the Kathmandu valley were the main sources of the high CO2 in the pre-monsoon period. CH4 showed a maximum in September due to additional emissions from paddy fields. Seasonally, winter has the highest CH4 concentration which is due to brick production, which is a seasonal activity, and other local sources combined with the shallow mixing layer height in winter. The diurnal pattern of CO2 and CH4

  1. Hyper and hypothyroidism change the expression and diurnal variation of thyroid hormone receptor isoforms in rat liver without major changes in their zonal distribution

    NARCIS (Netherlands)

    Zandieh-Doulabi, B.; Platvoet-ter Schiphorst, M.; Kalsbeek, A.; Wiersinga, W. M.; Bakker, O.

    2004-01-01

    We investigated the effect of hypothyroidism or hyperthyroidism on mRNA and protein expression, diurnal variation and zonal distribution of thyroid hormone receptor (TR) isoforms TRalpha1 TRalpha2 and TRbeta1 in rat liver. Hypothyroidism results in increased isoform mRNA and protein expression

  2. Effects of diurnal temperature variation on microbial community and petroleum hydrocarbon biodegradation in contaminated soils from a sub-Arctic site.

    Science.gov (United States)

    Akbari, Ali; Ghoshal, Subhasis

    2015-12-01

    Contaminated soils are subject to diurnal and seasonal temperature variations during on-site ex-situ bioremediation processes. We assessed how diurnal temperature variations similar to that in summer at the site from which petroleum hydrocarbon-contaminated soil was collected affect the soil microbial community and the extent of biodegradation of petroleum hydrocarbons compared with constant temperature regimes. Microbial community analyses for 16S rRNA and alkB genes by pyrosequencing indicated that the microbial community for soils incubated under diurnal temperature variation from 5°C to 15°C (VART5-15) evolved similarly to that for soils incubated at constant temperature of 15°C (CST15). In contrast, under a constant temperature of 5°C (CST5), the community evolved significantly different. The extent of biodegradation of C10-C16 hydrocarbons in the VART5-15 systems was 48%, comparable with the 41% biodegradation in CST15 systems, but significantly higher than CST5 systems at 11%. The enrichment of Gammaproteobacteria was observed in the alkB gene-harbouring communities in VART5-15 and CST15 but not in CST5 systems. However, the Actinobacteria was abundant at all temperature regimes. The results suggest that changes in microbial community composition as a result of diurnal temperature variations can significantly influence petroleum hydrocarbon bioremediation performance in cold regions. © 2015 Society for Applied Microbiology and John Wiley & Sons Ltd.

  3. The Zodiacal Cloud Model applied to the Martian atmosphere. Diurnal variations in meteoric ion layers

    Science.gov (United States)

    Carrillo-Sánchez, J. D.; Plane, J. M. C.; Withers, P.; Fallows, K.; Nesvorny, D.; Pokorný, P.

    2016-12-01

    Sporadic metal layers have been detected in the Martian atmosphere by radio occultation measurements using the Mars Express Orbiter and Mars Global Surveyor spacecraft. More recently, metallic ion layers produced by the meteor storm event following the close encounter between Comet Siding Spring (C/2013 A1) and Mars were identified by the Imaging UltraViolet Spectrograph (IUVS) and the Neutral Gas and Ion Mass Spectrometer (NGIMS) on the Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. Work is now in progress to detect the background metal layers produced by the influx of sporadic meteors. In this study we predict the likely appearance of these layers. The Zodiacal Dust Cloud (ZDC) model for particle populations released by asteroids (AST), and dust grains from Jupiter Family Comets (JFCs) and Halley-Type Comets (HTCs) has been combined with a Monte Carlo sampling method and the Chemical ABlation MODel (CABMOD) to predict the ablation rates of Na, K, Fe, Si, Mg, Ca and Al above 40 km altitude in the Martian atmosphere. CABMOD considers the standard treatment of meteor physics, including the balance of frictional heating by radiative losses and the absorption of heat energy through temperature increases, melting phase transitions and vaporization, as well as sputtering by inelastic collisions with the air molecules. The vertical injection profiles are input into the Leeds 1-D Mars atmospheric model which includes photo-ionization, and gas-phase ion-molecule and neutral chemistry, in order to explore the evolution of the resulting metallic ions and atoms. We conclude that the dominant contributor in the Martian's atmosphere is the JFCs over other sources. Finally, we explore the changes of the neutral and ionized Na, Mg and Fe layers over a diurnal cycle.

  4. Diurnal variations in the occurrence and the fate of hormones and antibiotics in activated sludge wastewater treatment in Oslo, Norway

    International Nuclear Information System (INIS)

    Plosz, Benedek Gy.; Leknes, Henriette; Liltved, Helge; Thomas, Kevin V.

    2010-01-01

    We present an assessment of the dynamics in the influent concentration of hormones (estrone, estriol) and antibiotics (trimethoprim, sulfamethoxazole, tetracycline, ciprofloxacin) in the liquid phase including the efficiency of biological municipal wastewater treatment. The concentration of estradiol, 17-α-ethinylestradiol, doxycycline, oxytetracycline, demeclocycline, chlortetracycline, cefuroxime, cyclophosphamide, and ifosfamide were below the limit of detection in all of the sewage samples collected within this study. Two different types of diurnal variation pattern were identified in the influent mass loads of selected antibiotics and hormones that effectively correlate with daily drug administration patterns and with the expected maximum human hormone release, respectively. The occurrence of natural hormones and antimicrobials, administered every 12 hours, shows a daily trend of decreasing contaminant mass load, having the maximum values in the morning hours. The occurrence of antibiotics, typically administered every 8 hours, indicates a daily peak value in samples collected under the highest hydraulic loading. The efficiency of biological removal of both hormones and antibiotics is shown to be limited. Compared to the values obtained in the influent samples, increased concentrations are observed in the biologically treated effluent for trimethoprim, sulfamethoxazole and ciprofloxacin, mainly as a result of deconjugation processes. Ciprofloxacin is shown as the predominant antimicrobial compound in the effluent, and it is present at quantities approximately 10 fold greater than the total mass of the other of the compounds due to poor removal efficiency and alternating solid-liquid partitioning behaviour. Our results suggest that, to increase the micro-pollutant removal and the chemical dosing efficiency in enhanced tertiary treatment, significant benefits can be derived from the optimisation of reactor design and the development of control schemes that

  5. Diurnal variations in the occurrence and the fate of hormones and antibiotics in activated sludge wastewater treatment in Oslo, Norway

    Energy Technology Data Exchange (ETDEWEB)

    Plosz, Benedek Gy., E-mail: benedek.plosz@niva.no [Norwegian Institute for Water Research, NIVA, Gaustadalleen 21, NO-0349, Oslo (Norway); Leknes, Henriette [Norwegian Institute for Air Research NILU, 2027 Kjeller (Norway); Liltved, Helge; Thomas, Kevin V. [Norwegian Institute for Water Research, NIVA, Gaustadalleen 21, NO-0349, Oslo (Norway)

    2010-03-15

    We present an assessment of the dynamics in the influent concentration of hormones (estrone, estriol) and antibiotics (trimethoprim, sulfamethoxazole, tetracycline, ciprofloxacin) in the liquid phase including the efficiency of biological municipal wastewater treatment. The concentration of estradiol, 17-{alpha}-ethinylestradiol, doxycycline, oxytetracycline, demeclocycline, chlortetracycline, cefuroxime, cyclophosphamide, and ifosfamide were below the limit of detection in all of the sewage samples collected within this study. Two different types of diurnal variation pattern were identified in the influent mass loads of selected antibiotics and hormones that effectively correlate with daily drug administration patterns and with the expected maximum human hormone release, respectively. The occurrence of natural hormones and antimicrobials, administered every 12 hours, shows a daily trend of decreasing contaminant mass load, having the maximum values in the morning hours. The occurrence of antibiotics, typically administered every 8 hours, indicates a daily peak value in samples collected under the highest hydraulic loading. The efficiency of biological removal of both hormones and antibiotics is shown to be limited. Compared to the values obtained in the influent samples, increased concentrations are observed in the biologically treated effluent for trimethoprim, sulfamethoxazole and ciprofloxacin, mainly as a result of deconjugation processes. Ciprofloxacin is shown as the predominant antimicrobial compound in the effluent, and it is present at quantities approximately 10 fold greater than the total mass of the other of the compounds due to poor removal efficiency and alternating solid-liquid partitioning behaviour. Our results suggest that, to increase the micro-pollutant removal and the chemical dosing efficiency in enhanced tertiary treatment, significant benefits can be derived from the optimisation of reactor design and the development of control schemes that

  6. Origin of transient cosmic ray intensity variations

    International Nuclear Information System (INIS)

    Duggal, S.P.; Pomerantz, M.A.

    1977-01-01

    A new approach to determining the solar progenitor of transient cosmic ray intensity variations has revealed that in a statistical sense, solar flares, heretofore regarded as the predominant source of the modulation, actually do not precede the reduction in flux observed at earth. Superposed epoch analysis of the cosmic ray data with respect to the time of occurrence of all 379 solar flares of importance (Imp) < or =2 observed during solar cycle 20 (1964-1974 inclusive) shows that the onset of a decrease in the composite nucleonic intensity at polar stations occurs prior to the zero day (i.e., time of the flare) well before the arrival in the vicinity of earth of the associated solar plasma. The statistical significance of this result is confirmed by comparing the pooled variance determined from Chree analysis of an equal number of random epochs with that of the curve representing the flare epochs. Subdivision of the latter into three groups according to the heliographic longitude of the flares shows that whereas eastern flares might be associated with cosmic ray decreases, central (30degree to -30degree) and western flares cannot be thus related. A similar analysis of all flares of Imp< or =2 that occurred in a selected set of 24 extraordinary flare-rich active centers during 1964--1974 confirms these results and shows that the observed cosmic ray intensity decrease is, in fact, associated with the central meridian passage ( +- 1 day) of the active regions. Thus earlier conclusions concerning relationships between the heliolongitude of flares and their apparent effectiveness in producing Forbush decreases require reevaluation. The specific feature associated with solar active centers that is actually the principal source of transient modulations remanins to be identified

  7. Diurnal and Seasonal Variations in Mid-Latitude Geomagnetic Field During International Quiet Days: BOH Magnetometer

    Directory of Open Access Journals (Sweden)

    Junga Hwang

    2012-12-01

    Full Text Available Korea Astronomy and Space Science Institute researchers have installed and operated magnetometers at Bohyunsan Observatory to measure the Earth's magnetic field variations in South Korea. In 2007, we installed a fluxgate magnetometer (RFP-523C to measure H, D, and Z components of the geomagnetic field. In addition, in 2009, we installed a Overhauser proton sensor to measure the absolute total magnetic field F and a three-axis magneto-impedance sensor for spectrum analysis. Currently three types of magnetometer data have been accumulated. In this paper, we use the H, D, Z components of fluxgate magnetometer data to investigate the characteristics of mid-latitude geomagnetic field variation. To remove the temporary changes in Earth’s geomagnetic filed by space weather, we use the international quiet days’ data only. In other words, we performed a superposed epoch analysis using five days per each month during 2008-2011. We find that daily variations of H, D, and Z shows similar tendency compared to previous results using all days. That is, H, D, Z all three components’ quiet intervals terminate near the sunrise and shows maximum 2-3 hours after the culmination and the quiet interval start from near the sunset. Seasonal variations show similar dependences to the Sun. As it becomes hot season, the geomagnetic field variation’s amplitude becomes large and the quiet interval becomes shortened. It is well-known that these variations are effects of Sq current system in the Earth’s atmosphere. We confirm that the typical mid-latitude geomagnetic field variations due to the Sq current system by excluding all possible association with the space weather.

  8. diurnal variation in blood parameters in the chicken in the hot

    African Journals Online (AJOL)

    Dr Olaleye

    Twelve adult male chicken of the Nigerian local strain were bled every 3 Hours for 24 hours. Haematological and serum biochemical parameters were measured in the samples collected. Variations in the levels of these parameters throughout the 24 hours were determined. Thirteen out of the parameters measured showed.

  9. Diurnal and Reproductive Stage-Dependent Variation of Parental Behaviour in Captive Zebra Finches

    NARCIS (Netherlands)

    Morvai, Boglarka; Nanuru, Sabine; Mul, Douwe; Kusche, Nina; Milne, Gregory; Szekely, Tamas; Komdeur, Jan; Miklosi, Adam; Pogany, Akos

    2016-01-01

    Parental care plays a key role in ontogeny, life-history trade-offs, sexual selection and intrafamilial conflict. Studies focusing on understanding causes and consequences of variation in parental effort need to quantify parental behaviour accurately. The applied methods are, however, diverse even

  10. [Effects of silicon supply on diurnal variations of physiological properties at rice heading stage under elevated UV-B radiation].

    Science.gov (United States)

    Wu, Lei; Lou, Yun-sheng; Meng, Yan; Wang, Wei-qing; Cui, He-yang

    2015-01-01

    A pot experiment was conducted to investigate the effects of silicon (Si) supply on diurnal variations of photosynthesis and transpiration-related physiological parameters at rice heading stage under elevated UV-B radiation. The experiment was designed with two UV-B radiation levels, i.e. ambient UV-B. (ambient, A) and elevated UV-B (elevated by 20%, E), and four Si supply levels, i.e. Sio (control, 0 kg SiO2 . hm-2), Si, (sodium silicate, 100 kg SiO2 . hm-2), Si2 (sodium silicate, 200 kg SiO2 . hm2), Si3 (slag fertilizer, 200 kg SiO2 . hm-2). The results showed that, compared with ambient UV-B radiation, elevated UV-B radiation decreased the net photosynthesis rate (Pn) , intercellular CO2 concentration (Ci), transpiration rate (Tr), stomatal conductivity (gs) and water use efficiency (WUE) by 11.3%, 5.5%, 10.4%, 20.3% and 6.3%, respectively, in the treatment without Si supply (Si, level), and decreased the above parameters by 3.8%-5.5%, 0.7%-4.8%, 4.0%-8.7%, 7.4%-20.2% and 0.7%-5.9% in the treatments with Si supply (Si1, Si2 and Si3 levels) , respectively. Namely, elevated UV-B radiation decreased the photosynthesis and transpiration-related physiological parameters, but silicon supply could obviously mitigate the depressive effects of elevated UV-B radiation. Under elevated UV-B radiation, compared with control (Si0 level), silicon supply increased Pn, Ci, gs and WUE by 16.9%-28.0%, 3.5%-14.3%, 16.8% - 38.7% and 29.0% - 51.2%, respectively, but decreased Tr by 1.9% - 10.8% in the treatments with Si supply (Si1 , Si2 and Si3 levels). That is, silicon supply could mitigate the depressive effects of elevated UV-B radiation through significantly increasingnP., CigsgK and WUE, but decreasing T,. However, the difference existed in ameliorating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among the treatments of silicon supply, with the sequence of Si3>Si2>1i >Si0. This study suggested that fertilizing slag was

  11. Diurnal Variation of Plasma Brain-Derived Neurotrophic Factor Levels in Women with Functional Hypothalamic Amenorrhea.

    Science.gov (United States)

    Drakopoulos, Panagiotis; Casarosa, Elena; Bucci, Fiorella; Piccinino, Manuela; Wenger, Jean-Marie; Nappi, Rossella Elena; Polyzos, Nicholas; Genazzani, Andrea Riccardo; Pluchino, Nicola

    2015-01-01

    Brain-derived neurotrophic factor (BDNF) is strongly related to hormonal networks and is modulated by hypothalamic activity. To evaluate plasma BDNF concentration in patients with functional hypothalamic amenorrhea (FHA), with reference to the BDNF circadian rhythm and its relation with the cortisol (F) rhythm, and to assess whether the duration of amenorrhea might influence the BDNF:F ratio in FHA. This was an observational study evaluating 36 amenorrheic and 30 eumenorrheic women. Basal values of BDNF and hormones were examined in blood samples collected from 7:00 to 9:00 h in all the women. Basal BDNF and F levels were determined in blood samples collected in 12 subjects from each group at 8:00, 12:00, 16:00, 20:00, and 24:00 h. BDNF plasma levels are significantly lower in amenorrheic women (p 0.05), sex steroids, and F in FHA. Low plasma BDNF levels in FHA are not significantly correlated with duration of amenorrhea. The 24-hour variation of BDNF in amenorrheic women is significantly lower when compared to the control group, and normal daily variations of BDNF disappeared in FHA patients. F preserved its circadian rhythm in both groups. Interactions between BDNF, the hypothalamus-pituitary-adrenal axis, and sex steroids might be critical in clinical conditions of modified homeostasis/adaptation, such as FHA. © 2015 S. Karger AG, Basel.

  12. [Effects of Morus alba and Setaria italica intercropping on their plant growth and diurnal variation of photosynthesis].

    Science.gov (United States)

    Zhu, Wen-Xu; Zhang, Hui-Hui; Xu, Nan; Wang, Peng; Wang, Shi-Dan; Mu, Shi-Nan; Liang, Ming; Sun, Guang-Yu

    2012-07-01

    A field investigation was conducted to study the effects of intercropping Morus aIba and Setaria italica on their dry matter production, land use efficiency, and diurnal variation of leaf photosynthesis. Under intercropping, the plant height, basal diameter, root length, and branch number of M. alba increased by 6.0%, 13.7%, 6.8%, and 14.8%, respectively, and the leaf yield of M. alba was increased by 31.3%, as compared with monoculture M. alba. In contrast, the plant height and root length of intercropped S. italica had no significant difference with those of monoculture S. italica. Intercropping enhanced the equivalent ratio and use efficiency of arable land. For both M. alba and S. italica in monoculture or intercropping, their leaf photosynthetic depression all occurred at midday (12 :00), but the leaf photosynthetic depression of monoculture M. alba was heavier than that of intercropped M. alba. Intercropping promoted the leaf stomatal conductance (g(s)) and water use efficiency (WUE) of M. alba at midday, increased the photosynthetic carbon assimilation of M. alba, and inhibited the decline of M. alba leaf actual photochemical efficiency of PS II (phi(PS II)), photosynthetic electron transport rate (ETR), and the maximal photochemical of PS II (F(v)/F(m)) , which might contribute to alleviate the leaf photosynthetic depression of M. alba at midday. It was concluded that M. alba and S. italica intercropping could obviously improve the leaf photosynthetic capacity of M. alba.

  13. Summertime diurnal variations in the isotopic composition of atmospheric nitrogen dioxide at a small midwestern United States city

    Science.gov (United States)

    Walters, Wendell W.; Fang, Huan; Michalski, Greg

    2018-04-01

    The nitrogen and oxygen stable isotopes (δ15N & δ18O) of nitrogen oxides (NOx = nitric oxide (NO) + nitrogen dioxide (NO2)) may be a useful tool for partitioning NOx emission sources and for evaluating NOx photochemical cycling, but few measurements of in situ NOx exist. In this study, we have collected and characterized the diurnal variability in δ15N and δ18O of NO2 from ambient air at a small Midwestern city (West Lafayette, IN, USA, 40.426° N, 86.908° W) between July 7 to August 5, 2016, using an active sampling technique. Large variations were observed in both δ15N(NO2) and δ18O(NO2) that ranged from -31.4 to 0.4‰ and 41.5-112.5‰, respectively. Daytime averages were -9.2 ± 5.7‰ (x̅ ± 1σ) and 86.5 ± 14.1‰ (n = 11), while nighttime averages were -13.4 ± 7.3‰ and 56.3 ± 7.1‰ (n = 12) for δ15N(NO2) and δ18O(NO2), respectively. The large variability observed in δ15N(NO2) is predicted to be driven by changing contributions of local NOx emission sources, as calculated isotope effects predict a minor impact on δ15N(NO2) relative to δ15N(NOx) that is generally less than 2.5‰ under the sample collection conditions of high ozone concentration ([O3]) relative to [NOx]. A statistical δ15N mass-balance model suggests that traffic-derived NOx is the main contributor to the sampling site (0.52 ± 0.22) with higher relative contribution during the daytime (0.58 ± 0.19) likely due to higher traffic volume than during the nighttime (0.47 ± 0.22). The diurnal cycle observed in δ18O(NO2) is hypothesized to be a result of the photochemical cycling of NOx that elevates δ18O(NO2) during the daytime relative to the nighttime. Overall, this data suggests the potential to use δ15N(NO2) for NOx source partitioning under environmental conditions of high [O3] relative to [NOx] and δ18O(NO2) for evaluating VOC-NOx-O3 chemistry.

  14. Short-term variations in mesozooplankton, ichthyoplankton, and nutrients associated with semi-diurnal tides in a patagonian Gulf

    Science.gov (United States)

    Castro, L. R.; Cáceres, M. A.; Silva, N.; Muñoz, M. I.; León, R.; Landaeta, M. F.; Soto-Mendoza, S.

    2011-03-01

    The relationships between the distribution of different zooplankton and ichthyoplankton stages and physical and chemical variables were studied using samples and data (CTD profiles, ADCP and current meter measurements, nutrients, mesozooplankton, ichthyoplankton) obtained from different strata during two 24-h cycles at two oceanographic stations in a Chilean Patagonian gulf during the CIMAR 10-Fiordos cruise (November, 2004). A station located at the Chacao Channel was dominated by tidal mixing and small increments in surface stratification during high tides, leading to decreased nutrient availability. This agreed with short periods of increased phytoplankton abundance during slack waters at the end of flood currents. Increases in larval density for all zooplankton and ichthyoplankton taxa corresponded to the flooding phases of the tidal cycle. When the larval density data were fit to a sinusoidal model, the regression coefficients were high, suggesting that tides are important features that modulate short-term variations in plankton abundance. All larvae did not vary synchronously with the tidal phase; rather, time lags were observed among species. The abundances of older individuals of the copepodite Rhincalanus nasutus and all zoea stages of the squat lobster Munida gregaria increased during night flood tides, whereas younger stages increased during daytime flood tides. At a station located at the Queullin Pass, which was dominated by vertical stratification patterns, the variations in peak larval density were better fitted to the semi-diurnal sea level fluctuations. Other evidence indicated internal tides below the pycnocline, which could promote larval transport in deeper layers. In the overall picture that emerges from this study, planktonic organisms from different habitats and phylogenetic origins seem to respond to the local tidal regimes. In some cases, this response might be beneficial, transporting these individuals inshore to areas that are rich in

  15. Diurnal, Seasonal, and Interannual Variations of Cloud Properties Derived for CERES From Imager Data

    Science.gov (United States)

    Minnis, Patrick; Young, David F.; Sun-Mack, Sunny; Trepte, Qing Z.; Chen, Yan; Brown, Richard R.; Gibson, Sharon; Heck, Patrick W.

    2004-01-01

    Simultaneous measurement of the radiation and cloud fields on a global basis is a key component in the effort to understand and model the interaction between clouds and radiation at the top of the atmosphere, at the surface, and within the atmosphere. The NASA Clouds and Earth s Radiant Energy System (CERES) Project, begun in 1998, is meeting this need. Broadband shortwave (SW) and longwave radiance measurements taken by the CERES scanners at resolutions between 10 and 20 km on the Tropical Rainfall Measuring Mission (TRMM), Terra, and Aqua satellites are matched to simultaneous retrievals of cloud height, phase, particle size, water path, and optical depth OD from the TRMM Visible Infrared Scanner (VIRS) and the Moderate Resolution Imaging Spectroradiometer (MODIS) on Terra and Aqua. Besides aiding the interpretation of the broadband radiances, the CERES cloud properties are valuable for understanding cloud variations at a variety of scales. In this paper, the resulting CERES cloud data taken to date are averaged at several temporal scales to examine the temporal and spatial variability of the cloud properties on a global scale at a 1 resolution.

  16. Diurnal variations in blood gases and metabolites for draught Zebu and Simmental oxen.

    Science.gov (United States)

    Zanzinger, J; Hoffmann, I; Becker, K

    1994-01-01

    In previous articles it has been shown that blood parameters may be useful to assess physical fitness in draught cattle. The aim of the present study was to detect possible variations in baseline values for the key metabolites: lactate and free fatty acids (FFA), and for blood gases in samples drawn from a catheterized jugular vein. Sampling took place immediately after venipuncture at intervals of 3 min for 1 hr in Simmental oxen (N = 6) and during a period of 24 hr at intervals of 60 min for Zebu (N = 4) and Simmental (N = 6) oxen. After puncture of the vein, plasma FFA and oxygen (pvO2) were elevated for approximately 15 min. All parameters returned to baseline values within 1 hr of the catheter being inserted. Twenty-four-hour mean baseline values for all measured parameters were significantly different (P draught work. It is concluded that a strict standardization of blood sampling, at least in respect of time after feeding, is required for a reliable interpretation of endurance-indicating blood parameters measured under field conditions.

  17. Altitude variation of cosmic-ray neutrons

    International Nuclear Information System (INIS)

    Nakamura, T.; Uwamino, Y.; Ohkubo, T.; Hara, A.

    1987-01-01

    The altitude variation of the cosmic-ray neutron energy spectrum and the dose equivalent rate was measured at an average geomagnetic latitude of 24 degrees N by using the high-efficiency multi-sphere neutron spectrometer and neutron dose-equivalent counter developed by the authors. The data were obtained from a 2-h flight over Japan on 27 February 1985. The neutron energy spectra measured at sea level and at altitudes of 4880 m and at 11,280 m were compared with the calculated spectra of O'Brien and with other experimental spectra, and they are in moderately good agreement with them. The dose equivalent rate increases according to a quadratic curve up to about 6000 m and then increases linearly between 6000 m and 11,280 m. The dependence of dose equivalent rates at sea level and at an altitude of 12,500 m on geomagnetic latitude also is given by referring to other experimental results

  18. Diurnal Variations of Human Circulating Cell-Free Micro-RNA.

    Directory of Open Access Journals (Sweden)

    Niels H H Heegaard

    Full Text Available A 24-hour light and dark cycle-dependent rhythmicity pervades physiological processes in virtually all living organisms including humans. These regular oscillations are caused by external cues to endogenous, independent biological time-keeping systems (clocks. The rhythm is reflected by gene expression that varies in a circadian and specific fashion in different organs and tissues and is regulated largely by dynamic epigenetic and post-transcriptional mechanisms. This leads to well-documented oscillations of specific electrolytes, hormones, metabolites, and plasma proteins in blood samples. An emerging, important class of gene regulators is short single-stranded RNA (micro-RNA, miRNA that interferes post-transcriptionally with gene expression and thus may play a role in the circadian variation of gene expression. MiRNAs are promising biomarkers by virtue of their disease-specific tissue expression and because of their presence as stable entities in the circulation. However, no studies have addressed the putative circadian rhythmicity of circulating, cell-free miRNAs. This question is important both for using miRNAs as biological markers and for clues to miRNA function in the regulation of circadian gene expression. Here, we investigate 92 miRNAs in plasma samples from 24 young male, healthy volunteers repeatedly sampled 9 times during a 24-hour stay in a regulated environment. We demonstrate that a third (26/79 of the measurable plasma miRNAs (using RT-qPCR on a microfluidic system exhibit a rhythmic behavior and are distributed in two main phase patterns. Some of these miRNAs weakly target known clock genes and many have strong targets in intracellular MAPK signaling pathways. These novel findings highlight the importance of considering bio-oscillations in miRNA biomarker studies and suggest the further study of a set of specific circulating miRNAs in the regulation and functioning of biological clocks.

  19. On the possibility of recovering palaeo-diurnal magnetic variations in transitional lava flows. 2. An experimental case study

    Science.gov (United States)

    Vérard, Christian; Leonhardt, Roman; Winklhofer, Michael; Fabian, Karl

    2008-08-01

    amplitude with increasing blocking temperature, which is contrary to what would be expected if pronounced diurnal external field variations were trapped in the flow.

  20. Application of Synthetic Storm Technique for Diurnal and Seasonal Variation of Slant Path Ka-Band Rain Attenuation Time Series over a Subtropical Location in South Africa

    Directory of Open Access Journals (Sweden)

    J. S. Ojo

    2015-01-01

    Full Text Available As technology advances and more demands are on satellite services, rain-induced attenuation still creates one of the most damaging effects of the atmosphere on the quality of radio communication signals, especially those operating above 10 GHz. System designers therefore require statistical information on rain-induced attenuation over the coverage area in order to determine the appropriate transmitter and receiver characteristics to be adopted. This paper presents results on the time-varying rain characterization and diurnal variation of slant path rain attenuation in the Ka-band frequency simulated with synthetic storm techniques over a subtropical location in South Africa using 10-year rain rate time-series data. The analysis is based on the CDF of one-minute rain rate; time-series seasonal variation of rain rate observed over four time intervals: 00:00–06:00, 06:00–12:00, 12:00–18:00, and 18:00–24:00; diurnal fades margin; and diurnal variation of rain attenuation. Comparison was also made between the synthesized values and measured attenuation data. The predicted statistics are in good agreement with those obtained from the propagation beacon measurement in the area. The overall results will be needed for an acceptable planning that can effectively reduce the fade margin to a very low value for an optimum data communication over this area.

  1. Hygroscopic properties of ultrafine aerosol particles in the boreal forest: diurnal variation, solubility and the influence of sulfuric acid

    Directory of Open Access Journals (Sweden)

    M. Ehn

    2007-01-01

    Full Text Available The hygroscopic growth of aerosol particles present in a boreal forest was measured at a relative humidity of 88%. Simultaneously the gas phase concentration of sulfuric acid, a very hygroscopic compound, was monitored. The focus was mainly on days with new particle formation by nucleation. The measured hygroscopic growth factors (GF correlated positively with the gaseous phase sulfuric acid concentrations. The smaller the particles, the stronger the correlation, with r=0.20 for 50 nm and r=0.50 for 10 nm particles. The increase in GF due to condensing sulfuric acid is expected to be larger for particles with initially smaller masses. During new particle formation, the changes in solubility of the new particles were calculated during their growth to Aitken mode sizes. As the modal diameter increased, the solubility of the particles decreased. This indicated that the initial particle growth was due to more hygroscopic compounds, whereas the later growth during the evening and night was mainly caused by less hygroscopic or even hydrophobic compounds. For all the measured sizes, a diurnal variation in GF was observed both during days with and without particle formation. The GF was lowest at around midnight, with a mean value of 1.12–1.24 depending on particle size and if new particle formation occurred during the day, and increased to 1.25–1.34 around noon. This can be tentatively explained by day- and nighttime gas-phase chemistry; different vapors will be present depending on the time of day, and through condensation these compounds will alter the hygroscopic properties of the particles in different ways.

  2. The relationship of age-adjusted Charlson comorbidity ındex and diurnal variation of blood pressure.

    Science.gov (United States)

    Kalaycı, Belma; Erten, Yunus Turgay; Akgün, Tunahan; Karabag, Turgut; Kokturk, Furuzan

    2018-03-05

    Charlson Comorbidity index (CCI) is a scoring system to predict prognosis and mortality. It exhibits better utility when combined with age, age-adjusted Charlson Comorbidity Index (ACCI). The aim of this study was to evaluate the relationship between ACCI and diurnal variation of blood pressure parameters in hypertensive patients and normotensive patients. We enrolled 236 patients. All patients underwent a 24-h ambulatory blood pressure monitoring (ABPM) for evaluation of dipper or non-dipper pattern. We searched the correlation between ACCI and dipper or non-dipper pattern and other ABPM parameters. To further investigate the role of these parameters in predicting survival, a multivariate analysis using the Cox proportional hazard model was performed. 167 patients were in the hypertensive group (87 patients in non-dipper status) and 69 patients were in the normotensive group (41 patients in non-dipper status) of all study patients. We found a significant difference and negative correlation between AACI and 24-h diastolic blood pressure (DBP), awake DBP, awake mean blood pressure (MBP) and 24-h MBP and awake systolic blood pressure(SBP). Night decrease ratio of blood pressure had also a negative correlation with ACCI (p = 0.003, r = -0.233). However, we found a relationship with non-dipper pattern and ACCI in the hypertensive patients (p = 0.050). In multivariate Cox analysis sleep MBP was found related to mortality like ACCI (p = 0.023, HR = 1.086, %95 CI 1.012-1.165) Conclusion: ACCI was statistically significantly higher in non-dipper hypertensive patients than dipper hypertensive patients while ACCI had a negative correlation with blood pressure. Sleep MBP may predict mortality.

  3. Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

    Energy Technology Data Exchange (ETDEWEB)

    Takeda, Kazuhiko, E-mail: takedaq@hiroshima-u.ac.jp [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Nakatani, Nobutake [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan); Department of Environmental and Symbiotic Sciences, Rakuno Gakuen University, 582 Bunkyodai-Midorimachi, Ebetsu, Hokkaido 069-8501 (Japan); Sakugawa, Hiroshi [Graduate School of Biosphere Science, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8521 (Japan)

    2014-09-15

    We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area.

  4. Spatial distributions of and diurnal variations in low molecular weight carbonyl compounds in coastal seawater, and the controlling factors

    International Nuclear Information System (INIS)

    Takeda, Kazuhiko; Katoh, Shinya; Mitsui, Yumi; Nakano, Shinichi; Nakatani, Nobutake; Sakugawa, Hiroshi

    2014-01-01

    We studied the spatial distributions of and the diurnal variations in four low molecular weight (LMW) carbonyl compounds, formaldehyde, acetaldehyde, propionaldehyde, and glyoxal, in coastal seawater. The samples were taken from the coastal areas of Hiroshima Bay, the Iyo Nada, and the Bungo Channel, western Japan. The formaldehyde, acetaldehyde, and glyoxal concentrations were higher in the northern part of Hiroshima Bay than at offshore sampling points in the Iyo Nada and the Bungo Channel. These three compounds were found at much higher concentrations in the surface water than in deeper water layers in Hiroshima Bay. It is noteworthy that propionaldehyde was not detected in any of the seawater samples, the concentrations present being lower than the detection limit (1 nanomole per liter (nM)) of the high performance liquid chromatography (HPLC) system we used. Photochemical and biological experiments were performed in the laboratory to help understand the characteristic distributions and fates of the LMW carbonyl compounds. The primary process controlling their fate in the coastal environment appears to be their biological consumption. The direct photo degradation of propionaldehyde, initiated by ultraviolet (UV) absorption, was observed, although formaldehyde and acetaldehyde were not degraded by UV irradiation. Our results suggest that the degradation of the LMW carbonyl compounds by photochemically formed hydroxyl radicals is relatively insignificant in the study area. Atmospheric deposition is a possible source of soluble carbonyl compounds in coastal surface seawater, but it may not influence the carbonyl concentrations in offshore waters. - Highlights: • Low molecular weight (LMW) carbonyl compounds in coastal seawater were determined. • Photochemical productions of LMW carbonyl compounds in seawater were observed. • LMW carbonyl compounds were largely consumed biologically. • Photochemical degradation was relatively insignificant in the study area

  5. Diurnal, monthly and seasonal variation of mean winds in the MLT region observed over Kolhapur using MF radar

    Science.gov (United States)

    Sharma, A. K.; Gaikwad, H. P.; Ratnam, M. Venkat; Gurav, O. B.; Ramanjaneyulu, L.; Chavan, G. A.; Sathishkumar, S.

    2018-04-01

    Medium Frequency (MF) radar located at Kolhapur (16.8°N, 74.2°E) has been upgraded in August 2013. Since then continuous measurements of zonal and meridional winds are obtained covering larger altitudes from the Mesosphere and Lower Thermosphere (MLT) region. Diurnal, monthly and seasonal variation of these mean winds is presented in this study using four years (2013-2017) of observations. The percentage occurrence of radar echoes show maximum between 80 and 105 km. The mean meridional wind shows Annual Oscillation (AO) between 80 and 90 km altitudes with pole-ward motion during December solstice and equatorial motion during June solstice. Quasi-biennial oscillation (QBO) with weaker amplitudes are also observed between 90 and 104 km. Zonal winds show semi-annual oscillation (SAO) with westward winds during equinoxes and eastward winds during solstices between 80 and 90 km. AO with eastward winds during December solstice and westward wind in the June solstice is also observed in the mean zonal wind between 100 and 110 km. These results match well with that reported from other latitudes within Indian region between 80 and 90 km. However, above 90 km the results presented here provide true mean background winds for the first time over Indian low latitude region as the present station is away from equatorial electro-jet and are not contaminated by ionospheric processes. Further, the results presented earlier with an old version of this radar are found contaminated due to unknown reasons and are corrected in the present work. This upgraded MF radar together with other MLT radars in the Indian region forms unique network to investigate the vertical and lateral coupling.

  6. Solar wind velocity and daily variation of cosmic rays

    International Nuclear Information System (INIS)

    Ahluwalia, H.S.; Riker, J.F.

    1985-01-01

    Recently parameters applicable to the solar wind and the interplanetary magnetic field (IMF) have become much better defined. Superior quality of data bases that are now available, particularly for the post-1971 period, make it possible to believe the long-term trends in the data. These data are correlated with the secular changes observed in the diurnal variation parameters obtained from neutron monitor data at Deep River and underground muon telescope data at Embudo (30 MEW) and Socorro (82 MWE). The annual mean amplitudes appear to have large values during the epochs of high speed solar wind streams. Results are discussed

  7. Diurnal Variation of Rainfall Associated with Tropical Depression in South China and its Relationship to Land-Sea Contrast and Topography

    Directory of Open Access Journals (Sweden)

    Yuchun Zhao

    2013-12-01

    Full Text Available Convective precipitation associated with tropical depression (TD is one primary type of post-flooding season rainfall in South China (SC. Observations of the Tropical Rainfall Measuring Mission (TRMM satellite have shown specific diurnal features of convective rainfall in South China, which is somewhat different from that in other seasons or regions of China. Convective precipitation is usually organized into a rainfall band along the southeastern coast of South China in the early morning hours. The rainfall band develops and intensifies quickly in the morning, then moves inland in the afternoon and, finally, diminishes at night. The daily convective rainfall along the coast is much more than that in the inland region, and heavy rainfall is often found along the coast. A long-duration heavy rainfall event associated with tropical depression “Fitow” during the period from 28 August to 6 September 2001, is selected in this study to explore the diurnal feature of convective rainfall and its formation mechanism. Modeling results of the 10-day heavy rainfall event are compared with both rain-gauge observation and satellite-retrieved rainfall. Total precipitation and its spatial distribution, as well as diurnal variations are reasonably simulated and agree well with observations. Further analysis reveals that the development and movement of convective precipitation is mainly related to the land and sea breezes. The anomalous height-latitudinal circulation in the morning-to-noon hours is completely reversed in the afternoon-to-late-evening hours, with the convective rainfall swinging back and forth, following its updraft branch. Sensitivity experiments show that the afternoon convective rainfall in the inland region of SC is caused by the diurnal variation of solar radiation forcing. The mountain range along the coast and the complex topography in the inland region of SC plays a critical role in the enhancement of diurnal convective rainfall

  8. Diurnal, seasonal and long-term variations of global formaldehyde columns inferred from combined OMI and GOME-2 observations

    Science.gov (United States)

    De Smedt, I.; Stavrakou, T.; Hendrick, F.; Danckaert, T.; Vlemmix, T.; Pinardi, G.; Theys, N.; Lerot, C.; Gielen, C.; Vigouroux, C.; Hermans, C.; Fayt, C.; Veefkind, P.; Müller, J.-F.; Van Roozendael, M.

    2015-11-01

    We present the new version (v14) of the BIRA-IASB algorithm for the retrieval of formaldehyde (H2CO) columns from spaceborne UV-visible sensors. Applied to OMI measurements from Aura and to GOME-2 measurements from MetOp-A and MetOp-B, this algorithm is used to produce global distributions of H2CO representative of mid-morning and early afternoon conditions. Its main features include (1) a new iterative DOAS scheme involving three fitting intervals to better account for the O2-O2 absorption, (2) the use of earthshine radiances averaged in the equatorial Pacific as reference spectra, and (3) a destriping correction and background normalisation resolved in the across-swath position. For the air mass factor calculation, a priori vertical profiles calculated by the IMAGES chemistry transport model at 09:30 and 13:30 LT are used. Although the resulting GOME-2 and OMI H2CO vertical columns are found to be highly correlated, some systematic differences are observed. Afternoon columns are generally larger than morning ones, especially in mid-latitude regions. In contrast, over tropical rainforests, morning H2CO columns significantly exceed those observed in the afternoon. These differences are discussed in terms of the H2CO column variation between mid-morning and early afternoon, using ground-based MAX-DOAS measurements available from seven stations in Europe, China and Africa. Validation results confirm the capacity of the combined satellite measurements to resolve diurnal variations in H2CO columns. Furthermore, vertical profiles derived from MAX-DOAS measurements in the Beijing area and in Bujumbura are used for a more detailed validation exercise. In both regions, we find an agreement better than 15 % when MAX-DOAS profiles are used as a priori for the satellite retrievals. Finally, regional trends in H2CO columns are estimated for the 2004-2014 period using SCIAMACHY and GOME-2 data for morning conditions, and OMI for early afternoon conditions. Consistent features

  9. Seasonal and diurnal variations in methane and carbon dioxide in the Kathmandu Valley in the foothills of the central Himalayas

    Science.gov (United States)

    Singh Mahata, Khadak; Panday, Arnico Kumar; Rupakheti, Maheswar; Singh, Ashish; Naja, Manish; Lawrence, Mark G.

    2017-10-01

    .3) ppm in the winter season. The maximum seasonal mean mixing ratio of CH4 in winter was only 0.057 ppm or 2.6 % higher than the seasonal minimum during the pre-monsoon period, while CO2 was 12.8 ppm or 3.1 % higher during the pre-monsoon period (seasonal maximum) than during the monsoon (seasonal minimum). On the other hand, the CO mixing ratio at Bode was 191 % higher during the winter than during the monsoon season. The enhancement in CO2 mixing ratios during the pre-monsoon season is associated with additional CO2 emissions from forest fires and agro-residue burning in northern South Asia in addition to local emissions in the Kathmandu Valley. Published CO/CO2 ratios of different emission sources in Nepal and India were compared with the observed CO/CO2 ratios in this study. This comparison suggested that the major sources in the Kathmandu Valley were residential cooking and vehicle exhaust in all seasons except winter. In winter, brick kiln emissions were a major source. Simultaneous measurements in Bode and Chanban (15 July-3 October 2015) revealed that the mixing ratios of CO2, CH4, and CO were 3.8, 12, and 64 % higher in Bode than Chanban. The Kathmandu Valley thus has significant emissions from local sources, which can also be attributed to its bowl-shaped geography that is conducive to pollution build-up. At Bode, all three gas species (CO2, CH4, and CO) showed strong diurnal patterns in their mixing ratios with a pronounced morning peak (ca. 08:00), a dip in the afternoon, and a gradual increase again through the night until the next morning. CH4 and CO at Chanban, however, did not show any noticeable diurnal variations. These measurements provide the first insights into the diurnal and seasonal variation in key greenhouse gases and air pollutants and their local and regional sources, which is important information for atmospheric research in the region.

  10. Seasonal and diurnal variations in methane and carbon dioxide in the Kathmandu Valley in the foothills of the central Himalayas

    Directory of Open Access Journals (Sweden)

    K. S. Mahata

    2017-10-01

    , 417.3 (±23.1 ppm in the post-monsoon, and 421.9 (±20.3 ppm in the winter season. The maximum seasonal mean mixing ratio of CH4 in winter was only 0.057 ppm or 2.6 % higher than the seasonal minimum during the pre-monsoon period, while CO2 was 12.8 ppm or 3.1 % higher during the pre-monsoon period (seasonal maximum than during the monsoon (seasonal minimum. On the other hand, the CO mixing ratio at Bode was 191 % higher during the winter than during the monsoon season. The enhancement in CO2 mixing ratios during the pre-monsoon season is associated with additional CO2 emissions from forest fires and agro-residue burning in northern South Asia in addition to local emissions in the Kathmandu Valley. Published CO∕CO2 ratios of different emission sources in Nepal and India were compared with the observed CO∕CO2 ratios in this study. This comparison suggested that the major sources in the Kathmandu Valley were residential cooking and vehicle exhaust in all seasons except winter. In winter, brick kiln emissions were a major source. Simultaneous measurements in Bode and Chanban (15 July–3 October 2015 revealed that the mixing ratios of CO2, CH4, and CO were 3.8, 12, and 64 % higher in Bode than Chanban. The Kathmandu Valley thus has significant emissions from local sources, which can also be attributed to its bowl-shaped geography that is conducive to pollution build-up. At Bode, all three gas species (CO2, CH4, and CO showed strong diurnal patterns in their mixing ratios with a pronounced morning peak (ca. 08:00, a dip in the afternoon, and a gradual increase again through the night until the next morning. CH4 and CO at Chanban, however, did not show any noticeable diurnal variations. These measurements provide the first insights into the diurnal and seasonal variation in key greenhouse gases and air pollutants and their local and regional sources, which is important information for atmospheric research in the region.

  11. Changes In Some Physiological And Chemical Parameters Of Ostrich In Response To The Seasonal And Diurnal Temperature Variations

    International Nuclear Information System (INIS)

    Khalil, M.H.; Khalifa, H.H.; Elaroussi, M.A.; Elsayed, M.A.; Basuony, H.A.

    2011-01-01

    The present study was carried out to evaluate the effect of temperature variation during summer and winter seasons and diurnal effect on ostrich performance and changes in some physiological and blood chemical parameters. Twelve immature ostrich birds (7 months old) were exposed to daily natural ambient temperatures during the summer and winter. The birds were fed a grower ration ad libitum (19 % protein and 2450 K cal ME/kg) and the daily feed consumption (g/ bird/day) and water consumption (ml/bird/day) were measured for a representative 7 days during each season. Cloacal temperatures was measured and blood samples were collected twice; one in the morning at 7:00 am and the other in the afternoon at 15.00 pm during a representative 7 hot days of June (40±2 degree C) (summer) and the 7 cold days of January (18±2 degree C) (winter). Red blood cells count (RBC) and total white blood cells count (WBC), hemoglobin (Hb) and packed cell volume (PCV) were determined. Mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH) and mean corpuscular hemoglobin concentrations (MCHC) were calculated. In serum, levels of total protein (TP), albumin (A) and globulin (G), alanine transaminase (ALT), aspartate transaminase (AST), glucose, triglycerides, cholesterol, triiodothyronine (T 3 ) and cortisol were estimated. Results indicated that feed consumption unlike water consumption was significantly increased during winter than in summer season. Moreover, body temperature was increased significantly during the summer season as compared with the winter season and was significantly elevated at the afternoon than at the morning. Blood picture showed that hemoglobin (Hb), packed cell volume (PCV), red blood cells count (RBC) and total white blood cells count (WBC) were significantly decreased in the summer than in winter at the two diurnal periods. Also, both mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) were significantly increased in summer than winter

  12. Spatial and temporal variations of diurnal ichthyofauna on surf-zone of São Francisco do Itabapoana beaches, Rio de Janeiro State, Brazil

    Directory of Open Access Journals (Sweden)

    Gomes Marcelo Paes

    2003-01-01

    Full Text Available Spatial and temporal variations of diurnal ichthyofauna and the environmental variables influences on its distribution were studied at the surf-zone of three beaches of São Francisco do Itabapoana, northern coast of Rio de Janeiro, Brazil. From August/1999 to August/2000, three beach seine hauls were made monthly, and environmental variables were recorded. A total number of 4,562 fishes (74,155g were sampled at the three beaches, where estuarine-dependent species prevailed (44%, followed by marine (31%, estuarine (19% and freshwater species (3%. Species richness, number of individuals and wet weight were significantly higher at Gargaú, followed by Manguinhos and Barra do Itabapoana, respectively. Canonical Correspondence Analysis highlighted influences of the rivers flushing, salinity and plant abundance on the diurnal ichthyofauna distribution and dynamics of São Francisco do Itabapoana surf-zone.

  13. Change in diurnal variations of meteorological variables induced by anthropogenic aerosols over the North China Plain in summer 2008

    Science.gov (United States)

    Gao, Yi; Zhang, Meigen; Liu, Xiaohong; Wang, Lili

    2016-04-01

    This study investigates the impacts of all anthropogenic aerosols and anthropogenic black carbon (BC) on the diurnal variations of meteorological variables in the atmospheric boundary layer over the North China Plain (NCP) during June to August 2008, using a coupled meteorology and chemistry model (WRF-Chem). The results of the ensemble numerical experiments show that surface air temperature decreases by about 0.6 to 1.2 K with the maximum decrease over the Beijing urban area and the southern part of Hebei province, and the surface relative humidity (RH) increases by 2-4 % owing to all anthropogenic aerosols. On the contrary, anthropogenic BC induces a small change of temperature and RH at surface. Averaged for Beijing, Tianjin, and Hebei province (BTH region) and High Particle Concentration (HPC) periods when PM2.5 surface concentration is more than 60 μg m-3 and daily AOD is more than 0.9, all anthropogenic aerosols decrease air temperature under 850 hPa and increase it between 500 and 850 hPa, while anthropogenic BC increases it for whole atmosphere. The maximum changes occur at 08:00-20:00 (local time). Aerosol-induced surface energy and diabatic heating change leads to a cooling at the surface and in the lower atmosphere and a warming in the middle troposphere at 08:00-17:00, with reversed effects at 20:00-05:00. BC cools the atmosphere at the surface and warms the atmosphere above for the whole day. As a result, the equivalent potential temperature profile change shows that the lower atmosphere is more stable at 08:00 and 14:00. All anthropogenic aerosols decrease the surface wind speed by 20-60 %, while anthropogenic BC decreases the wind speed by 10-40 % over the NCP with the maximum decrease at 08:00. The aerosol-induced stabilization of the lower atmosphere favors the accumulation of air pollutants and thus contributes to deterioration of visibility and fog-haze events.

  14. Diurnal variations in depth profiles of UV-induced DNA damage and inhibition of bacterioplankton production in tropical coastal waters

    NARCIS (Netherlands)

    Visser, PM; Poos, JJ; Scheper, BB; Boelen, P; van Duyl, FC

    2002-01-01

    In this study, diurnal changes in bacterial production and DNA damage in bacterio-plankton (measured as cyclobutane pyrimidine dimers, CPDs) incubated in bags at different depths in tropical coastal waters were investigated. The DNA damage and inhibition of the bacterial production was highest at

  15. Multivariate analysis of effects of diurnal temperature and seasonal humidity variations by tropical savanna climate on the emissions of anthropogenic volatile organic compounds.

    Science.gov (United States)

    Liu, Chih-Chung; Chen, Wei-Hsiang; Yuan, Chung-Shin; Lin, Chitsan

    2014-02-01

    Volatile organic compounds (VOCs), particularly those from anthropogenic sources, have been of substantial concern. In this study, the influences of diurnal temperature and seasonal humidity variations by tropical savanna climate on the distributions of VOCs from stationary industrial sources were investigated by analyzing the concentrations during the daytime and nighttime in the dry and wet seasons and assessing the results by principal component analysis (PCA) and cluster analysis. Kaohsiung City in Southern Taiwan, known for its severe VOC pollution, was chosen as the location to be examined. In the results, the VOC concentrations were lower during the daytime and in the wet season, possibly attributed to the stronger photochemical reactions and increasing inhibition of VOC emissions and transports by elevating humidity levels. Certain compounds became appreciably more important at higher humidity, as these compounds were saturated hydrocarbons with relatively low molecular weights. The influence of diurnal temperature variation on VOC distribution behaviors seemed to be less important than and interacted with that of seasonal humidity variation. Heavier aromatic hydrocarbons with more complex structures and some aliphatic compounds were found to be the main species accounting for the maximum variances of the data observed at high humidity, and the distinct grouping of compounds implied a pronounced inherent characteristic of each cluster in the observed VOC distributions. Under the influence of diurnal temperature variation, selected VOCs that may have stronger photochemical resistances and/or longer lifetimes in the atmosphere were clustered with each other in the cluster analysis, whereas the other groups might consist of compounds with different levels of vulnerability to sunlight or high temperatures. These findings prove the complications in the current knowledge regarding the VOC contaminations and providing insight for managing the adverse impacts of

  16. Diurnal variations of wildfire emissions in Europe: analysis of the MODIS and SEVIRI measurements in the framework of the regional scale air pollution modelling

    Science.gov (United States)

    Konovalov, Igor B.; Beekmann, Matthias; Kaiser, Johannes W.; Shudyaev, Anton A.; Yurova, Alla; Kuznetsova, Irina N.

    2013-04-01

    Wildfires episodically provide a major contribution to air pollution in many regions of the world. For example, the extreme air pollution level and strongly reduced visibility were observed in the Central European region of Russia during the intensive wildfire events in summer of 2010. Such episodes provide a strong impetus for further developments in air pollution modeling, aimed at improving the ability of chemistry transport models to simulate and predict evolution of atmospheric composition affected by wildfires. The main goals of our study are (1) to investigate the diurnal cycles of air pollutant emissions from wildfires in several European regions, taking into account the fire radiative power (FRP) satellite measurements for different vegetation land cover types and (2) to examine the possibilities of improving air pollution simulations by assimilating the diurnal variability of the FRP measurements performed by the polar orbiting (MODIS) and geostationary (SEVIRI) satellite instruments into a chemistry transport model. These goals are addressed for the case of wildfires occurred in summer 2010. The analysis of both the MODIS and SEVIRI data indicate that air pollutant emissions from wildfires in Europe in summer 2010 were typically much larger during daytime than during nighttime. The important exception is intensive fires around Moscow, featuring an almost "flat" diurnal cycle. These findings confirm the similar results reported earlier [1] but also extend them by attributing the flat diurnal cycle only to forest fires and by examining a hypothetical association of the "abnormal" diurnal cycle of FRP with peat fires. The derived diurnal variations of wildfire emissions have been used in the framework of the modeling system employed in our previous studies of the atmospheric effects of the 2010 Russian wildfires [2, 3]. The numerical experiments reveal that while the character of the diurnal variation of wildfire emissions has a rather small impact on the

  17. Effects of sea surface temperature, cloud radiative and microphysical processes, and diurnal variations on rainfall in equilibrium cloud-resolving model simulations

    International Nuclear Information System (INIS)

    Jiang Zhe; Li Xiao-Fan; Zhou Yu-Shu; Gao Shou-Ting

    2012-01-01

    The effects of sea surface temperature (SST), cloud radiative and microphysical processes, and diurnal variations on rainfall statistics are documented with grid data from the two-dimensional equilibrium cloud-resolving model simulations. For a rain rate of higher than 3 mm·h −1 , water vapor convergence prevails. The rainfall amount decreases with the decrease of SST from 29 °C to 27 °C, the inclusion of diurnal variation of SST, or the exclusion of microphysical effects of ice clouds and radiative effects of water clouds, which are primarily associated with the decreases in water vapor convergence. However, the amount of rainfall increases with the increase of SST from 29 °C to 31 °C, the exclusion of diurnal variation of solar zenith angle, and the exclusion of the radiative effects of ice clouds, which are primarily related to increases in water vapor convergence. For a rain rate of less than 3 mm·h −1 , water vapor divergence prevails. Unlike rainfall statistics for rain rates of higher than 3 mm·h −1 , the decrease of SST from 29 °C to 27 °C and the exclusion of radiative effects of water clouds in the presence of radiative effects of ice clouds increase the rainfall amount, which corresponds to the suppression in water vapor divergence. The exclusion of microphysical effects of ice clouds decreases the amount of rainfall, which corresponds to the enhancement in water vapor divergence. The amount of rainfall is less sensitive to the increase of SST from 29 °C to 31 °C and to the radiative effects of water clouds in the absence of the radiative effects of ice clouds. (electromagnetism, optics, acoustics, heat transfer, classical mechanics, and fluid dynamics)

  18. Circadian and diurnal variation of circulating immune complexes, complement-mediated solubilization, and the complement split product C3d in rheumatoid arthritis

    DEFF Research Database (Denmark)

    Petersen, Ivan; Baatrup, Gunnar; Brandslund, I

    1986-01-01

    Nine patients with active classical rheumatoid arthritis (ARA criteria) were studied with reference to circadian variation of immunological and clinical parameters. Complement-mediated solubilization (CMS) of immune complexes (IC) and the level of circulating IC were found to be inversely related...... with low CMS and increased IC levels in the morning, and vice versa in the afternoon. Bed rest and exercise did not influence these fluctuations. The C3d concentration in plasma was increased but showed no diurnal or circadian periodic fluctuations when the levels were corrected for fluctuations in plasma...... albumin concentration. Clinical assessment by means of pain score exhibited marked variations, with high scores in the morning, and lower in the daytime, whereas measurements of Ritchie's joint index showed no consistent pattern. The circadian variations in CMS, serum IC and clinical parameters indicate...

  19. Partial ring currents and cosmic ray magnetic cutoff rigidity variations

    International Nuclear Information System (INIS)

    Arens, M.

    1978-01-01

    A short introduction on cosmic ray modulation and a description of the magnetosphere, and of some physical processes occurring within its boundaries are presented. 20 geomagnetic storms are analysed together with the cosmic ray intensities during these storms as measured by Neutron Monitors. Using a semi-empirical method, the variations in the magnetic cutoff rigidity for the mountain stations Pic du Midi and Jungfraujoch are deduced. These stations are the most sensitive for measuring these variations. The analysis shows that all analyzed storms have an asymmetric development phase. Often the asymmetry even continues during part of the recovery phase. It is shown that variations in magnetic cutoff rigidity occur only during the asymmetric phase of the storm. The largest variations are found when the cosmic ray station is located in the late afternoon-midnight sector. (Auth.)

  20. A statistical dynamics approach to the study of human health data: Resolving population scale diurnal variation in laboratory data

    International Nuclear Information System (INIS)

    Albers, D.J.; Hripcsak, George

    2010-01-01

    Statistical physics and information theory is applied to the clinical chemistry measurements present in a patient database containing 2.5 million patients' data over a 20-year period. Despite the seemingly naive approach of aggregating all patients over all times (with respect to particular clinical chemistry measurements), both a diurnal signal in the decay of the time-delayed mutual information and the presence of two sub-populations with differing health are detected. This provides a proof in principle that the highly fragmented data in electronic health records has potential for being useful in defining disease and human phenotypes.

  1. Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation

    Science.gov (United States)

    Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

    2016-02-01

    We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice ( Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m-2 day-1) and elevated UV-B radiation (E, a 20 % higher dose of UV-B than the reference, 14.4 kJ m-2 day-1), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha-1), Si1 (sodium silicate, 100 kg SiO2 ha-1), Si2 (sodium silicate, 200 kg SiO2 ha-1), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha-1). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate ( Pn), intercellular carbon dioxide (CO2) concentration ( Ci), transpiration rate ( Tr), stomatal conductivity ( Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3 %, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9 %, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2 %, respectively, but decreased Tr by 1.9-10.8 %, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the

  2. Effects of silicon application on diurnal variations of physiological properties of rice leaves of plants at the heading stage under elevated UV-B radiation.

    Science.gov (United States)

    Lou, Yun-sheng; Wu, Lei; Lixuan, Ren; Meng, Yan; Shidi, Zhao; Huaiwei, Zhu; Yiwei, Zhang

    2016-02-01

    We investigated the effects of silicon (Si) application on diurnal variations of photosynthetic and transpiration physiological parameters in potted rice (Oryza sativa L. cv Nanjing 45) at the heading stage. The plants were subjected to two UV-B radiation levels, i.e., reference UV-B (A, ambient, 12.0 kJ m(-2) day(-1)) and elevated UV-B radiation (E, a 20% higher dose of UV-B than the reference, 14.4 kJ m(-2) day(-1)), and four Si application levels, i.e., Si0 (no silicon supplementation, 0 kg SiO2 ha(-1)), Si1 (sodium silicate, 100 kg SiO2 ha(-1)), Si2 (sodium silicate, 200 kg SiO2 ha(-1)), and Si3 (slag silicon fertilizer, 200 kg SiO2 ha(-1)). Compared with the reference, elevated UV-B radiation decreased the diurnal mean values of the net photosynthetic rate (Pn), intercellular carbon dioxide (CO2) concentration (Ci), transpiration rate (Tr), stomatal conductivity (Gs), and water use efficiency (WUE) by 11.3, 5.5, 10.4, 20.3, and 6.3%, respectively, in plants not supplemented with silicon (Si0), and decreased the above parameters by 3.8-5.5, 0.7-4.8, 4.0-8.7, 7.4-20.2, and 0.7-5.9%, respectively, in plants treated with silicon (Si1, Si2, and Si3), indicating that silicon application mitigates the negative effects of elevated UV-B radiation. Under elevated UV-B radiation, silicon application (Si1, Si2, and Si3) increased the diurnal mean values of Pn, Ci, Gs, and WUE by 16.9-28.0, 3.5-14.3, 16.8-38.7, and 29.0-51.2%, respectively, but decreased Tr by 1.9-10.8%, compared with plants not treated with silicon (E+Si0), indicating that silicon application mitigates the negative effects of elevated UV-B radiation by significantly increasing the P n, C i, G s, and WUE and decreasing the T r of rice. Evident differences existed in mitigating the depressive effects of elevated UV-B radiation on diurnal variations of physiological parameters among different silicon application treatments, exhibiting as Si3>Si2>Si1>Si0. In addition to recycling steel industrial wastes, the

  3. Annual and diurnal variations of gaseous and particulate pollutants in 31 provincial capital cities based on in situ air quality monitoring data from China National Environmental Monitoring Center.

    Science.gov (United States)

    Zhao, Suping; Yu, Ye; Yin, Daiying; He, Jianjun; Liu, Na; Qu, Jianjun; Xiao, Jianhua

    2016-01-01

    Long-term air quality data with high temporal and spatial resolutions are needed to understand some important processes affecting the air quality and corresponding environmental and health effects. The annual and diurnal variations of each criteria pollutant including PM2.5 and PM10 (particulate matter with aerodynamic diameter less than 2.5 μm and 10 μm, respectively), CO (carbon monoxide), NO2 (nitrogen dioxide), SO2 (sulfur dioxide) and O3 (ozone) in 31 provincial capital cities between April 2014 and March 2015 were investigated by cluster analysis to evaluate current air pollution situations in China, and the cities were classified as severely, moderately, and slightly polluted cities according to the variations. The concentrations of air pollutants in winter months were significantly higher than those in other months with the exception of O3, and the cities with the highest CO and SO2 concentrations were located in northern China. The annual variation of PM2.5 concentrations in northern cities was bimodal with comparable peaks in October 2014 and January 2015, while that in southern China was unobvious with slightly high PM2.5 concentrations in winter months. The concentrations of particulate matter and trace gases from primary emissions (SO2 and CO) and NO2 were low in the afternoon (~16:00), while diurnal variation of O3 concentrations was opposite to that of other pollutants with the highest values in the afternoon. The most polluted cities were mainly located in North China Plain, while slightly polluted cities mostly focus on southern China and the cities with high altitude such as Lasa. This study provides a basis for the formulation of future urban air pollution control measures in China. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Seasonal and diurnal variation of outdoor radon (222Rn) concentrations in urban and rural area with reference to meteorological conditions

    International Nuclear Information System (INIS)

    Podstawczynska, A.; Pawlak, W.; Kozak, K.; Mazur, J.

    2010-01-01

    The objective of the study was to investigate temporal variability of outdoor radon ( 222 Rn) concentration registered in the center of Lodz (urban station), at Ciosny (rural station) and Krakow (suburban station) in relation to meteorological parameters (i.e. air temperature, temperature vertical gradient, wind speed, soil heat flux, volumetric water content in soil) with special consideration of urban-rural differences. Continuous measurements of 222 Rn concentration (at 60 min intervals) were performed at a height of 2 m above the ground using AlphaGUARD PQ2000PRO (ionization chamber) from January 2008 to May 2009. 222 Rn levels were characterized by a diurnal cycle with an early morning maximum and a minimum in the afternoon. The well-marked 24 h pattern of radon concentration occurred in summer at anticyclonic weather with cloudless sky, light wind and large diurnal temperature ranges. The urban measurement site was characterized by the lowest atmospheric 222 Rn concentration and an urban-rural differences of radon levels increased from winter to summer and during the nighttime periods. The maximum contrasts of 222 Rn levels between Lodz and Ciosny, reaching - 30 Bq m -3 , were registered in June and July during the urban heat island (UHI) phenomenon (a positive thermal anomaly of a city if compared to rural area) and strong thermal inversion near the ground in the rural area. (authors)

  5. Sensitivity, reliability and the effects of diurnal variation on a test battery of field usable upper limb fatigue measures.

    Science.gov (United States)

    Yung, Marcus; Wells, Richard P

    2017-07-01

    Fatigue has been linked to deficits in production quality and productivity and, if of long duration, work-related musculoskeletal disorders. It may thus be a useful risk indicator and design and evaluation tool. However, there is limited information on the test-retest reliability, the sensitivity and the effects of diurnal fluctuation on field usable fatigue measures. This study reports on an evaluation of 11 measurement tools and their 14 parameters. Eight measures were found to have test-retest ICC values greater than 0.8. Four measures were particularly responsive during an intermittent fatiguing condition. However, two responsive measures demonstrated rhythmic behaviour, with significant time effects from 08:00 to mid-afternoon and early evening. Action tremor, muscle mechanomyography and perceived fatigue were found to be most reliable and most responsive; but additional analytical considerations might be required when interpreting daylong responses of MMG and action tremor. Practitioner Summary: This paper presents findings from test-retest and daylong reliability and responsiveness evaluations of 11 fatigue measures. This paper suggests that action tremor, muscle mechanomyography and perceived fatigue were most reliable and most responsive. However, mechanomyography and action tremor may be susceptible to diurnal changes.

  6. Analysis of Diurnal Variations in Energy Footprint and Its Associated Carbon Emission for Water Supply and Reuse in Arid and Semi-Arid Areas

    Science.gov (United States)

    Sobhani, Reza

    Arid and semi-arid regions throughout the world face water scarcity. Conventional water supply portfolio of these regions encompassed limited surface water, groundwater, and imported water. Current technological innovations technically and economically supplemented new water sources i.e., reclaimed water, desalted water and the groundwater sources that were not potable. The need for more efficient and alternative sources of drinking water supply necessitates studying the impediments e.g., intensive energy required, and emerging concern of the carbon emission. This dissertation discusses the challenges of energy footprint and its carbon emission among the processes involved in water supplies in the aforementioned regions. The conducted studies present time-dependent energy footprint analyses of different water reclamation and reuse processes. This study discusses the energy consumption in four main energy intensive processes inclusive of: activated sludge, microfiltration, reverse osmosis, and advanced oxidation with UV/ H2O2. The results indicate how the diurnal variations of different environmental parameters (e.g. flow and pollutant concentration) amplify the energy footprint variation among these processes. Meanwhile, the results show, due to the different power sources diurnally employed to provide electrical energy, the energy-associated carbon emission has more drastic variation in diurnal period compared to the energy footprint variation. In addition, this study presents the energy footprint of a modular process for treating local brackish groundwater by employing a combination of pellet reactor for radium and hardness minimization, reverse osmosis with intermediate precipitation, and concentrated brine crystallization to achieve high recovery with zero liquid discharge. Also it compares the energy footprint of the aforementioned process with the alternative option (i.e. desalted seawater conveyance with substantial lift). Finally, in coastal regions

  7. Impacts of diurnal variation of ultraviolet-B and photosynthetically active radiation on phycobiliproteins of the hot-spring cyanobacterium Nostoc sp. strain HKAR-2.

    Science.gov (United States)

    Kannaujiya, Vinod K; Sinha, Rajeshwar P

    2017-01-01

    The effects of diurnal variation of photosynthetically active radiation (PAR; 400-700 nm) and ultraviolet-B (UV-B; 280-315 nm) radiation on phycobiliproteins (PBPs) and photosynthetic pigments (PP) have been studied in the hot-spring cyanobacterium Nostoc sp. strain HKAR-2. The variations in PBPs and PP were monitored by alternating light and dark under PAR, UV-B, and PAR + UV-B radiations over a period of 25 h. There was a decline in the amount of Chl a and PBPs during light periods of UV-B and PAR + UV-B and an increase during dark periods showing a circadian rhythm by destruction and resynthesis of pigment-protein complex. However, a marked induction in carotenoids was recorded during light periods of the same radiations. Moreover, the ratio of Chl a/PE and Chl a/PC was increased in dark periods showing the resynthesis of bleached Chl a. The wavelength shift in emission fluorescence of PBPs toward shorter wavelengths further indicated the bleaching and destruction of PBPs during light periods. Oxidative damage upon exposure to PAR, UV-B, and PAR + UV-B was alleviated by induction of antioxidative enzymes such as superoxide dismutase (SOD), catalase (CAT), and ascorbate peroxidase (APX). The studied cyanobacterium exhibits a significant increase in the activities of SOD, CAT, and APX upon exposure to UV-B and PAR + UV-B radiations. The results indicate that pigment-protein composition of Nostoc sp. stain HKAR-2 was significantly altered during diurnal variation of light/radiation, which might play an important role in optimization for their productivity in a particular cyanobacterium.

  8. Diurnal cycle and seasonal variation of cloud cover over the Tibetan Plateau as determined from Himawari-8 new-generation geostationary satellite data.

    Science.gov (United States)

    Shang, Huazhe; Letu, Husi; Nakajima, Takashi Y; Wang, Ziming; Ma, Run; Wang, Tianxing; Lei, Yonghui; Ji, Dabin; Li, Shenshen; Shi, Jiancheng

    2018-01-18

    Analysis of cloud cover and its diurnal variation over the Tibetan Plateau (TP) is highly reliant on satellite data; however, the accuracy of cloud detection from both polar-orbiting and geostationary satellites over this area remains unclear. The new-generation geostationary Himawari-8 satellites provide high-resolution spatial and temporal information about clouds over the Tibetan Plateau. In this study, the cloud detection of MODIS and AHI is investigated and validated against CALIPSO measurements. For AHI and MODIS, the false alarm rate of AHI and MODIS in cloud identification over the TP was 7.51% and 1.94%, respectively, and the cloud hit rate was 73.55% and 80.15%, respectively. Using hourly cloud-cover data from the Himawari-8 satellites, we found that at the monthly scale, the diurnal cycle in cloud cover over the TP tends to increase throughout the day, with the minimum and maximum cloud fractions occurring at 10:00 a.m. and 18:00 p.m. local time. Due to the limited time resolution of polar-orbiting satellites, the underestimation of MODIS daytime average cloud cover is approximately 4.00% at the annual scale, with larger biases during the spring (5.40%) and winter (5.90%).

  9. Crab Nebula Variations in Hard X-rays

    Science.gov (United States)

    Wilson-Hodge, Colleen A.

    2012-01-01

    The Crab Nebula was surprisingly variable from 2001-2010, with less variability before 2001 and since mid-2010. We presented evidence for spectral softening from RXTE, Swift/BAT, and Fermi GBM during the mid-2008-2010 flux decline. We see no clear connections between the hard X-ray variations and the GeV flares

  10. Diurnal variation in the behaviour of the Pink-footed Goose (Anser brachyrhynchus) during the spring stopover in Trøndelag, Norway

    DEFF Research Database (Denmark)

    Chudzinska, Magda Ewa; Madsen, Jesper; Nabe-Nielsen, Jacob

    2013-01-01

    behaviour at a staging site and assess the extent to which behavioural patterns are attributable to physiological factors (digestibility of the food) and environmental conditions (flock size, type and frequency of disturbance and distance to roost). We found that feeding activity peaked at mid-day, whereas...... different energetic and nutrient demands when at spring staging sites. Seasonal changes in habitat availability as well as density dependence may also affect the birds’ behavioural patterns. A sporadic, unpredictable disturbance reduced the proportion of geese feeding to a greater extent than a predictable...... the birds were most alert in the morning and afternoon. The behaviour of Pink-footed Goose also varied with habitat type, disturbance level and distance to roost. The diurnal variation in feeding activity differed from behaviour reported for geese on the wintering grounds, indicating that the birds have...

  11. Seasonal, synoptic and diurnal variation of atmospheric water-isotopologues in the boundary layer of Southwestern Germany caused by plant transpiration, cold-front passages and dewfall.

    Science.gov (United States)

    Christner, Emanuel; Dyroff, Christoph; Kohler, Martin; Zahn, Andreas; Gonzales, Yenny; Schneider, Matthias

    2013-04-01

    Atmospheric water is an enormously crucial trace gas. It is responsible for ~70 % of the natural greenhouse effect (Schmidt et al., JGR, 2010) and carries huge amounts of latent heat. The isotopic composition of water vapor is an elegant tracer for a better understanding and quantification of the extremely complex and variable hydrological cycle in Earth's atmosphere (evaporation, cloud condensation, rainout, re-evaporation, snow), which in turn is a prerequisite to improve climate modeling and predictions. As H216O, H218O and HDO differ in vapor pressure and mass, isotope fractionation occurs due to condensation, evaporation and diffusion processes. In contrast to that, plants are able to transpire water with almost no isotope fractionation. For that reason the ratio of isotopologue concentrations in the boundary layer (BL) provides, compared to humidity measurements alone, independent and additional constraints for quantifying the strength of evaporation and transpiration. Furthermore the isotope ratios contain information about transport history of an air mass and microphysical processes, that is not accessible by humidity measurements. Within the project MUSICA (MUlti-platform remote Sensing of Isotopologues for investigating the Cycle of Atmospheric water) a commercial Picarro Analyzer L2120-i is operated at Karlsruhe in Southwestern Germany, which is continuously measuring the isotopologues H216O, HDO and H218O of atmospheric water vapor since January 2012. A one year record of H216O, HDO and H218O shows clear seasonal, synoptic and diurnal characteristics and reveals the main driving processes affecting the isotopic composition of water vapor in the Middle European BL. Changes in continental plant transpiration and evaporation throughout the year lead to a slow seasonal HDO/H216O-variation, that cannot be explained by pure Rayleigh condensation. Furthermore, cold-front passages from NW lead to fast and pronounced depletion of the HDO/H216O-ratio within

  12. Modulation of the atmospheric quasi-biweekly oscillation on the diurnal variation of the occurrence frequency of the Tibetan Plateau vortices

    Science.gov (United States)

    Li, Lun; Zhang, Renhe; Wen, Min

    2018-06-01

    In this study, modulation of the atmospheric quasi-biweekly oscillation (QBWO) on diurnal variation of the occurrence frequency of Tibetan Plateau vortices (TPVs) during May-August of 2000-2009 was investigated. The diurnal variations of the occurrence frequency of the TPVs (OFTPVs) and the related dynamic and thermodynamic features in the positive and negative phases of QBWO were compared. In both the positive and negative phases, the OFTPVs reaches the maximum from evening to midnight (18-00 LT, LT indicates the local time), and minimum from early morning to noon (06-12 LT). At 18 LT, there is strongest convergence at 500 hPa and ascending motion, as well as the most abundant net water vapor budget over the Tibetan Plateau, which is in favor of the precipitation and the related condensation latent heat release, corresponding to the maximum of OFTPVs in 18-00 LT. On the contrary, in the early morning at 06 LT, the conditions are most unfavorable for genesis of TPVs in 06-12 LT. QBWO leads to stronger convergence at 500 hPa, ascending motion as well as more massive water vapor in the positive phases than those in the negative phases, resulting in larger numbers of TPVs occur in all of the four periods of a day (00-06 LT, 06-12 LT, 12-18 LT, and 18-00 LT) in the former. The TPVs generating from the early morning to noon (06-12 LT) are weaker and more sensitive and fragile to the disadvantageous background, while the TPVs occurring from evening to midnight (18-00 LT) are stronger and seem to be well tolerated, leading to more remarkable contrast between the OFTPVs in the negative and positive phases in 06-12 LT than in 18-00 LT.

  13. Diurnal variation of stratospheric and lower mesospheric HOCl, ClO and HO2 at the equator: comparison of 1-D model calculations with measurements by satellite instruments

    Directory of Open Access Journals (Sweden)

    M. Khosravi

    2013-08-01

    Full Text Available The diurnal variation of HOCl and the related species ClO, HO2 and HCl measured by satellites has been compared with the results of a one-dimensional photochemical model. The study compares the data from various limb-viewing instruments with model simulations from the middle stratosphere to the lower mesosphere. Data from three sub-millimetre instruments and two infrared spectrometers are used, namely from the Sub-Millimetre Radiometer (SMR on board Odin, the Microwave Limb Sounder (MLS on board Aura, the Superconducting Submillimeter-wave Limb-Emission Sounder (SMILES on the International Space Station, the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS on board ENVISAT, and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS on board SCISAT. Inter-comparison of the measurements from instruments on sun-synchronous satellites (SMR, MLS, MIPAS and measurements from solar occultation instruments (ACE-FTS is challenging since the measurements correspond to different solar zenith angles (or local times. However, using a model which covers all solar zenith angles and data from the SMILES instrument which measured at all local times over a period of several months provides the possibility to verify the model and to indirectly compare the diurnally variable species. The satellite data were averaged for latitudes of 20° S to 20° N for the SMILES observation period from November 2009 to April 2010 and were compared at three altitudes: 35, 45 and 55 km. Besides presenting the SMILES data, the study also shows a first comparison of the latest MLS data (version 3.3 of HOCl, ClO, and HO2 with other satellite observations, as well as a first evaluation of HO2 observations made by Odin/SMR. The MISU-1D model has been carefully initialised and run for conditions and locations of the observations. The diurnal cycle features for the species investigated here are generally well reproduced by the model. The satellite

  14. Three dimensional analysis of cosmic ray intensity variation

    International Nuclear Information System (INIS)

    Yasue, Shin-ichi; Mori, Satoru; Nagashima, Kazuo.

    1974-01-01

    Three dimensional analysis of cosmic ray anisotropy and its time variation was performed. This paper describes the analysis of the Forbush decrease in Jan. 1968 to investigate by comparing the direction of the magnetic field in interplanetary space and the direction of the reference axis for cosmic ray anisotropy. New anisotropy becomes dominant at the time of Forbush decrease because the anisotropy of cosmic ray in calm state is wiped out. Such anisotropy produces intensity variation in neutron monitors on the ground. The characteristic parameters of three dimensional anisotropy can be determined from theoretical value and observed intensity. Analyzed data were taken for 6 days from Jan. 25 to Jan. 30, 1968, at Deep River. The decrease of intensity at Deep River was seen for several hours from 11 o'clock (UT), Jan. 26, just before The Forbush decrease. This may be due to the loss cone. The Forbush decrease began at 19 o'clock, Jan. 26, and the main phase continued to 5 o'clock in the next morning. The spectrum of variation was Psup(-0.5). The time variations of the magnetic field in interplanetary space and the reference axis of cosmic ray anisotropy are shown for 15 hours. The average directions of both are almost in coincidence. The spatial distribution of cosmic ray near the earth may be expressed by the superposition of axial symmetrical distribution along a reference axis and its push-out to the direction of 12 o'clock. It is considered that the direction of magnetic force line and the velocity of solar wind correspond to the direction of the reference axis and the magnitude of anisotropy in the direction of 12 o'clock, respectively. (Kato, T.)

  15. Long-term variations of cosmic ray intensity

    International Nuclear Information System (INIS)

    Dergachev, V.A.; Kocharov, G.E.; Ostryakov, V.M.

    1982-01-01

    At the present time we know only one possibility to reconstruct the Cosmic Ray intensity in the past. This possibility is connected with the measurements of radiocarbon abundance in the dendrochronologically dated wood samples. As the experiments carried out with the help of spacecrafts, balloons and ground apparatus show the Galactic Cosmic Ray flux essentially varies on a short time scales. The variations are caused by different astrophysical and geophysical phenomena. 14 C isotope allows us to investigate these reasons on a more long time interval in comparison with direct observational possibilities

  16. Diurnal and Seasonal Variations of Eddy-Covariance Carbon Dioxide Fluxes Above an Urban Wetland, Partitioned by Vegetation Cover

    Science.gov (United States)

    Schafer, K. V.; Duman, T.

    2017-12-01

    The New Jersey Meadowlands are an urban brackish marsh with a long history of human activity causing disturbances and alterations. Carbon emissions were measured from two sites in the Meadowlands, a natural site and a restored site, using eddy-covariance (EC) from 2014 to 2016. At each site, the EC towers were placed at the interface of two vegetation covers, allowing capturing this aspect of the wetland's heterogeneity. Using footprint modeling and light response curves we were able to partition measured fluxes between vegetation cover types and compare CO2 fluxes from patches of invasive versus native wetland vegetation communities. We show that further separating the data into seasonal and diurnal fluxes reveals patterns in CO2 fluxes that allow determining the nature of each vegetation cover as a source or sink for CO2. Our results also show that CO2 emissions from the restored wetland are significantly higher than the natural wetland. Areas of invasive Phragmites australis at the natural site had the lowest CO2 release rates during winter. These were consistently lower in magnitude than summer daytime uptake, therefore making this part of the wetland a CO2 sink. Areas planted with native Spartina alterniflora at the restored site had the largest uptake during daytime, therefore seemingly justifying restoration activities. However, they also had the highest emission rates during summer nighttime, and therefore the daily summer net uptake was not the highest compared with other vegetation covers. Furthermore, emissions from the restored site during winter were larger compared to the natural site, indicating that restoration activities might have led to a significant increase of carbon release from the wetland. Thus, during the study period the restored wetland acted as a carbon source.

  17. Atmospheric mercury in the Southern Hemisphere tropics: seasonal and diurnal variations and influence of inter-hemispheric transport

    Science.gov (United States)

    Howard, Dean; Nelson, Peter F.; Edwards, Grant C.; Morrison, Anthony L.; Fisher, Jenny A.; Ward, Jason; Harnwell, James; van der Schoot, Marcel; Atkinson, Brad; Chambers, Scott D.; Griffiths, Alan D.; Werczynski, Sylvester; Williams, Alastair G.

    2017-09-01

    Mercury is a toxic element of serious concern for human and environmental health. Understanding its natural cycling in the environment is an important goal towards assessing its impacts and the effectiveness of mitigation strategies. Due to the unique chemical and physical properties of mercury, the atmosphere is the dominant transport pathway for this heavy metal, with the consequence that regions far removed from sources can be impacted. However, there exists a dearth of long-term monitoring of atmospheric mercury, particularly in the tropics and Southern Hemisphere. This paper presents the first 2 years of gaseous elemental mercury (GEM) measurements taken at the Australian Tropical Atmospheric Research Station (ATARS) in northern Australia, as part of the Global Mercury Observation System (GMOS). Annual mean GEM concentrations determined at ATARS (0.95 ± 0.12 ng m-3) are consistent with recent observations at other sites in the Southern Hemisphere. Comparison with GEM data from other Australian monitoring sites suggests a concentration gradient that decreases with increasing latitude. Seasonal analysis shows that GEM concentrations at ATARS are significantly lower in the distinct wet monsoon season than in the dry season. This result provides insight into alterations of natural mercury cycling processes as a result of changes in atmospheric humidity, oceanic/terrestrial fetch, and convective mixing, and invites future investigation using wet mercury deposition measurements. Due to its location relative to the atmospheric equator, ATARS intermittently samples air originating from the Northern Hemisphere, allowing an opportunity to gain greater understanding of inter-hemispheric transport of mercury and other atmospheric species. Diurnal cycles of GEM at ATARS show distinct nocturnal depletion events that are attributed to dry deposition under stable boundary layer conditions. These cycles provide strong further evidence supportive of a multi-hop model of GEM

  18. Adaptive selection of diurnal minimum variation: a statistical strategy to obtain representative atmospheric CO2 data and its application to European elevated mountain stations

    Science.gov (United States)

    Yuan, Ye; Ries, Ludwig; Petermeier, Hannes; Steinbacher, Martin; Gómez-Peláez, Angel J.; Leuenberger, Markus C.; Schumacher, Marcus; Trickl, Thomas; Couret, Cedric; Meinhardt, Frank; Menzel, Annette

    2018-03-01

    Critical data selection is essential for determining representative baseline levels of atmospheric trace gases even at remote measurement sites. Different data selection techniques have been used around the world, which could potentially lead to reduced compatibility when comparing data from different stations. This paper presents a novel statistical data selection method named adaptive diurnal minimum variation selection (ADVS) based on CO2 diurnal patterns typically occurring at elevated mountain stations. Its capability and applicability were studied on records of atmospheric CO2 observations at six Global Atmosphere Watch stations in Europe, namely, Zugspitze-Schneefernerhaus (Germany), Sonnblick (Austria), Jungfraujoch (Switzerland), Izaña (Spain), Schauinsland (Germany), and Hohenpeissenberg (Germany). Three other frequently applied statistical data selection methods were included for comparison. Among the studied methods, our ADVS method resulted in a lower fraction of data selected as a baseline with lower maxima during winter and higher minima during summer in the selected data. The measured time series were analyzed for long-term trends and seasonality by a seasonal-trend decomposition technique. In contrast to unselected data, mean annual growth rates of all selected datasets were not significantly different among the sites, except for the data recorded at Schauinsland. However, clear differences were found in the annual amplitudes as well as the seasonal time structure. Based on a pairwise analysis of correlations between stations on the seasonal-trend decomposed components by statistical data selection, we conclude that the baseline identified by the ADVS method is a better representation of lower free tropospheric (LFT) conditions than baselines identified by the other methods.

  19. Adaptive selection of diurnal minimum variation: a statistical strategy to obtain representative atmospheric CO2 data and its application to European elevated mountain stations

    Directory of Open Access Journals (Sweden)

    Y. Yuan

    2018-03-01

    Full Text Available Critical data selection is essential for determining representative baseline levels of atmospheric trace gases even at remote measurement sites. Different data selection techniques have been used around the world, which could potentially lead to reduced compatibility when comparing data from different stations. This paper presents a novel statistical data selection method named adaptive diurnal minimum variation selection (ADVS based on CO2 diurnal patterns typically occurring at elevated mountain stations. Its capability and applicability were studied on records of atmospheric CO2 observations at six Global Atmosphere Watch stations in Europe, namely, Zugspitze-Schneefernerhaus (Germany, Sonnblick (Austria, Jungfraujoch (Switzerland, Izaña (Spain, Schauinsland (Germany, and Hohenpeissenberg (Germany. Three other frequently applied statistical data selection methods were included for comparison. Among the studied methods, our ADVS method resulted in a lower fraction of data selected as a baseline with lower maxima during winter and higher minima during summer in the selected data. The measured time series were analyzed for long-term trends and seasonality by a seasonal-trend decomposition technique. In contrast to unselected data, mean annual growth rates of all selected datasets were not significantly different among the sites, except for the data recorded at Schauinsland. However, clear differences were found in the annual amplitudes as well as the seasonal time structure. Based on a pairwise analysis of correlations between stations on the seasonal-trend decomposed components by statistical data selection, we conclude that the baseline identified by the ADVS method is a better representation of lower free tropospheric (LFT conditions than baselines identified by the other methods.

  20. Diurnal and Seasonal Variations in the Net Ecosystem CO2 Exchange of a Pasture in the Three-River Source Region of the Qinghai-Tibetan Plateau.

    Directory of Open Access Journals (Sweden)

    Bin Wang

    Full Text Available Carbon dioxide (CO2 exchange between the atmosphere and grassland ecosystems is very important for the global carbon balance. To assess the CO2 flux and its relationship to environmental factors, the eddy covariance method was used to evaluate the diurnal cycle and seasonal pattern of the net ecosystem CO2 exchange (NEE of a cultivated pasture in the Three-River Source Region (TRSR on the Qinghai-Tibetan Plateau from January 1 to December 31, 2008. The diurnal variations in the NEE and ecosystem respiration (Re during the growing season exhibited single-peak patterns, the maximum and minimum CO2 uptake observed during the noon hours and night; and the maximum and minimum Re took place in the afternoon and early morning, respectively. The minimum hourly NEE rate and the maximum hourly Re rate were -7.89 and 5.03 μmol CO2 m-2 s-1, respectively. The NEE and Re showed clear seasonal variations, with lower values in winter and higher values in the peak growth period. The highest daily values for C uptake and Re were observed on August 12 (-2.91 g C m-2 d-1 and July 28 (5.04 g C m-2 day-1, respectively. The annual total NEE and Re were -140.01 and 403.57 g C m-2 year-1, respectively. The apparent quantum yield (α was -0.0275 μmol μmol-1 for the entire growing period, and the α values for the pasture's light response curve varied with the leaf area index (LAI, air temperature (Ta, soil water content (SWC and vapor pressure deficit (VPD. Piecewise regression results indicated that the optimum Ta and VPD for the daytime NEE were 14.1°C and 0.65 kPa, respectively. The daytime NEE decreased with increasing SWC, and the temperature sensitivity of respiration (Q10 was 3.0 during the growing season, which was controlled by the SWC conditions. Path analysis suggested that the soil temperature at a depth of 5 cm (Tsoil was the most important environmental factor affecting daily variations in NEE during the growing season, and the photosynthetic photon

  1. A study of diurnal variations of PM2.5 acidity and related chemical species using a new thermodynamic equilibrium model

    International Nuclear Information System (INIS)

    Behera, Sailesh N.; Betha, Raghu; Liu, Ping; Balasubramanian, Rajasekhar

    2013-01-01

    Aerosol acidity is one of the most important parameters that can influence atmospheric visibility, climate change and human health. Based on continuous field measurements of inorganic aerosol species and their thermodynamic modeling on a time resolution of 1 h, this study has investigated the acidic properties of PM 2.5 and their relation with the formation of secondary inorganic aerosols (SIA). The study was conducted by taking into account the prevailing ambient temperature (T) and relative humidity (RH) in a tropical urban atmosphere. The in-situ aerosol pH (pH IS ) on a 12 h basis ranged from − 0.20 to 1.46 during daytime with an average value of 0.48 and 0.23 to 1.53 during nighttime with an average value of 0.72. These diurnal variations suggest that the daytime aerosol was more acidic than that caused by the nighttime aerosol. The hourly values of pH IS showed a reverse trend as compared to that of in-situ aerosol acidity ([H + ] Ins ). The pH IS had its maximum values at 3:00 and at 20:00 and its minimum during 11:00 to 12:00. Correlation analyses revealed that the molar concentration ratio of ammonium to sulfate (R N/S ), equivalent concentration ratio of cations to anions (R C/A ), T and RH can be used as independent variables for prediction of pH IS . A multi-linear regression model consisting of R N/S , R C/A, T and RH was developed to estimate aerosol pH IS. - Highlights: • Fine aerosol acidic characteristics were evaluated on an hourly basis. • Diurnal variations of in-situ acidity, water content and pH of aerosols were investigated. • Aerosols were more acidic during daytime than during nighttime. • The molar ratio of ammonium to sulfate and equivalent ratio of cations to anions were good indicators of aerosol acidity. • Meteorology had a significant effect on the hygroscopic nature of aerosol

  2. Mesoscale modeling of Central American smoke transport to the United States: 1. ``Top-down'' assessment of emission strength and diurnal variation impacts

    Science.gov (United States)

    Wang, Jun; Christopher, Sundar A.; Nair, U. S.; Reid, Jeffrey S.; Prins, Elaine M.; Szykman, James; Hand, Jenny L.

    2006-03-01

    As is typical in the Northern Hemisphere spring, during 20 April to 21 May 2003, significant biomass burning smoke from Central America was transported to the southeastern United States (SEUS). A coupled aerosol, radiation, and meteorology model that is built upon the heritage of the Regional Atmospheric Modeling System (RAMS), having newly developed capabilities of Assimilation and Radiation Online Modeling of Aerosols (AROMA) algorithm, was used to simulate the smoke transport and quantify the smoke radiative impacts on surface energetics, boundary layer, and other atmospheric processes. This paper, the first of a two-part series, describes the model and examines the ability of RAMS-AROMA to simulate the smoke transport. Because biomass-burning fire activities have distinct diurnal variations, the FLAMBE hourly smoke emission inventory that is derived from the geostationary satellite (GOES) fire products was assimilated into the model. In the "top-down" analysis, ground-based observations were used to evaluate the model performance, and the comparisons with model-simulated results were used to estimate emission uncertainties. Qualitatively, a 30-day simulation of smoke spatial distribution as well as the timing and location of the smoke fronts are consistent with those identified from the PM2.5 observation network, local air quality reports, and the measurements of aerosol optical thickness (AOT) and aerosol vertical profiles from the Southern Great Plains (SGP) Atmospheric Radiation Measurements (ARM) site in Oklahoma. Quantitatively, the model-simulated daily mean near-surface dry smoke mass correlates well with PM2.5 mass at 34 locations in Texas and with the total carbon mass and nonsoil potassium mass (KNON) at three IMPROVE sites along the smoke pathway (with linear correlation coefficients R = 0.77, 0.74, and 0.69 at the significance level larger than 0.99, respectively). The top-down sensitivity analysis indicates that the total smoke particle emission

  3. Absence of diurnal variation in visceromotor response to colorectal distention in normal Long Evans rats [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Sara Botschuijver

    2016-01-01

    Full Text Available Background: Enhanced colorectal sensitivity (i.e. visceral hypersensitivity is thought to be a pathophysiological mechanism in irritable bowel syndrome (IBS. In healthy men a circadian variation in rectal perception to colonic distention was described. Disturbed day and night rhythms, which occur in shift work and trans meridian flights, are associated with the prevalence of IBS. This raises the question whether disruptions of circadian control are responsible for the observed pathology in IBS. Prior to investigating altered rhythmicity in relation to visceral hypersensitivity in a rat model for IBS, it is relevant to establish whether normal rats display circadian variation similar to healthy men.  Methodology and findings: In rodents colorectal distension leads to reproducible contractions of abdominal musculature. We used quantification of this so called visceromotor response (VMR by electromyography (EMG to assess visceral sensitivity in rats. We assessed the VMR in normal male Long Evans rats at different time points of the light/dark cycle. Although a control experiment with male maternal separated rats confirmed that intentionally inflicted (i.e. stress induced changes in VMR can be detected, normal male Long Evans rats showed no variation in VMR along the light/dark cycle in response to colorectal distension. Conclusions: In the absence of a daily rhythm of colorectal sensitivity in normal control rats it is not possible to investigate possible aberrancies in our rat model for IBS.

  4. Large variations in diurnal and seasonal patterns of sap flux among Aleppo pine trees in semi-arid forest reflect tree-scale hydraulic adjustments

    Science.gov (United States)

    Preisler, Yakir; Tatarinov, Fyodor; Rohatyn, Shani; Rotenberg, Eyal; Grünzweig, José M.; Klein, Tamir; Yakir, Dan

    2015-04-01

    Adjustments and adaptations of trees to drought vary across different biomes, species and habitats, with important implications for tree mortality and forest dieback associated with global climate change. The aim of this study was to investigate possible links between the patterns of variations in water flux dynamics and drought resistance in Aleppo pine (Pinus halepensis) trees in a semi-arid stand (Yatir forest, Israel). We measured sap flow (SF) and variations in stem diameter, complemented with short-term campaigns of leaf-scale measurements of water vapour and CO2 gas exchange, branch water potential and hydraulic conductivity, as well as eddy flux measurements of evapotranspiration (ET) from a permanent flux tower at the site. SF rates were well synchronized with ET, reaching maximum rates during midday in all trees during the rainy season (Dec-Apr). However, during the dry season (May-Nov), the daily trend in the rates of SF greatly varied among trees, allowing classification into three tree classes: 1) trees with SF maximum rate constantly occurring in mid-day (12:00-13:00); 2)trees showing a shift to an early morning SF peak (04:00-06:00); and 3) trees shifting their daily SF peak to the evening (16:00-18:00). This classification did not change during the four years study period, between 2010 and 2014. Checking for correlation of tree parameters as DBH, tree height, crown size, and competition indices with rates of SF, indicated that timing of maximum SF in summer was mainly related to tree size (DBH), when large trees tended to have a later SF maximum. Dendrometer measurements indicated that large trees (high DBH) had maximum daily diameter in the morning during summer and winter, while small trees typically had maximum daily diameter during midday and afternoon in winter and summer, respectively. Leaf-scale transpiration (T) measurements showed typical morning peak in all trees, and another peak in the afternoon in large trees only. Different diurnal

  5. Diurnal pH variations of a Glacial Stream: a starting point for Inquiry-driven student and teacher Investigations of a Glacial Ecosystem

    Science.gov (United States)

    O'Brien, W. P.; Galbraith, J.; Fatland, D. R.; Heavner, M.

    2009-12-01

    Contemporary geoscience research often operates in a mode that generates huge repositories of data available on the internet to the scientific community and the general public. The SEAMONSTER (SM) online data browser of both archival and real-time data is an example of such a dynamic online ecosystem resource associated with the Juneau Icefield. Although newly developed database navigation tools and geobrowsers make it easy for non-experts to access data of interest, it nonetheless can be daunting to K-16 educators to fashion lesson plans that make effective use of these rich resources. In the following scenario, a student and associated teacher, operating outside the traditional didactic lecture/demo mode, explore and try to make sense of a tiny portion of SM data in a spirit of inquiry guided by curiosity, looking for features that catch their attention as they skim through interactive time-series graphs (96 samples/day) of data from Lemon Creek (which drains Lemon Glacier) for stream hydrological variables (temperature, pH, conductivity, dissolved oxygen, turbidity, discharge) and associated meteorological variables (precipitation, humidity, temperature). Amidst all the complex fluctuations that follow no immediately apparent pattern, one regular and continuous feature does stand out: a seemingly sinusoidal diurnal variation in pH of about 0.1 that peaks daily at noon. This high-frequency signal is superimposed on a slower signal characterized by multiple-day trends and larger fluctuations in pH. The resulting composite signal with its easily identifiable patterns is an ideal candidate for investigating Fourier signal decomposition. They hypothesize that photosynthesis could be a contributing factor to the diurnal signal and then design and run an experiment modeling bioactive streamwater with a blended chloroplast-rich slurry of fresh spinach leaves (spinach soup). They put a recording pH meter in the spinach soup and expose it to high and low levels of light

  6. Spectrographical method for determining temperature variations of cosmic rays

    International Nuclear Information System (INIS)

    Dorman, L.I.; Krest'yannikov, Yu.Ya.; AN SSSR, Irkutsk. Sibirskij Inst. Zemnogo Magnetizma Ionosfery i Rasprostraneniya Radiovoln)

    1977-01-01

    A spectrographic method for determining [sigmaJsup(μ)/Jsup(μ)]sub(T) temperature variations in cosmic rays is proposed. The value of (sigmaJsup(μ)/Jsup(μ)]sub(T) is determined from three equations for neutron supermonitors and the equation for the muon component of cosmic rays. It is assumed that all the observation data include corrections for the barometric effect. No temperature effect is observed in the neutron component. To improve the reliability and accuracy of the results obtained the surface area of the existing devices and the number of spectrographic equations should be increased as compared with that of the unknown values. The value of [sigmaJsup(μ)/Jsup(μ)]sub(T) for time instants when the aerological probing was carried out, was determined from the data of observations of cosmic rays with the aid of a spectrographic complex of devices of Sib IZMIR. The r.m.s. dispersion of the difference is about 0.2%, which agrees with the expected dispersion. The agreement obtained can be regarded as an independent proof of the correctness of the theory of meteorological effects of cosmic rays. With the existing detection accuracy the spectrographic method can be used for determining the hourly values of temperature corrections for the muon component

  7. Studying Stratospheric Temperature Variation with Cosmic Ray Measurements

    Science.gov (United States)

    Zhang, Xiaohang; He, Xiaochun

    2015-04-01

    The long term stratospheric cooling in recent decades is believed to be equally important as surface warming as evidence of influences of human activities on the climate system. Un- fortunatly, there are some discrepancies among different measurements of stratospheric tem- peratures, which could be partially caused by the limitations of the measurement techniques. It has been known for decades that cosmic ray muon flux is sensitive to stratospheric temperature change. Dorman proposed that this effect could be used to probe the tempera- ture variations in the stratophere. In this talk, a method for reconstructing stratospheric temperature will be discussed. We verify this method by comparing the stratospheric tem- perature measured by radiosonde with the ones derived from cosmic ray measurement at multiple locations around the globe.

  8. Variations of interplanetary parameters and cosmic-ray intensities

    International Nuclear Information System (INIS)

    Geranios, A.

    1980-01-01

    Observations of cosmic ray intensity depressions by earth bound neutron monitors and measurements of interplanetary parameter's variations aboard geocentric satellites in the period January 1972-July 1974 are analysed and grouped according to their correlation among them. From this analysis of about 30 cases it came out that the majority of the depressions correlates with the average propagation speed of interplanetary shocks as well as with the amplitude of the interplanetary magnetic field after the eruption of a solar flare. About one fourth of the events correlates with corotating fast solar wind streams. As the recovery time of the shock-related depressions depends strongly on the heliographic longitude of the causitive solar flare, it seems that the cosmic ray modulation region has a corotative-like feature. (Auth.)

  9. Variation of thermal parameters in two different color morphs of a diurnal poison toad, Melanophryniscus rubriventris (Anura: Bufonidae).

    Science.gov (United States)

    Sanabria, Eduardo A; Vaira, Marcos; Quiroga, Lorena B; Akmentins, Mauricio S; Pereyra, Laura C

    2014-04-01

    We study the variation in thermal parameters in two contrasting populations Yungas Redbelly Toads (Melanophryniscus rubriventris) with different discrete color phenotypes comparing field body temperatures, critical thermal maximum and heating rates. We found significant differences in field body temperatures of the different morphs. Temperatures were higher in toads with a high extent of dorsal melanization. No variation was registered in operative temperatures between the study locations at the moment of capture and processing. Critical thermal maximum of toads was positively related with the extent of dorsal melanization. Furthermore, we founded significant differences in heating rates between morphs, where individuals with a high extent of dorsal melanization showed greater heating rates than toads with lower dorsal melanization. The color pattern-thermal parameter relationship observed may influence the activity patterns and body size of individuals. Body temperature is a modulator of physiological and behavioral functions in amphibians, influencing daily and seasonal activity, locomotor performance, digestion rate and growth rate. It is possible that some growth constraints may arise due to the relationship of color pattern-metabolism allowing different morphs to attain similar sizes at different locations instead of body-size clines. Copyright © 2014. Published by Elsevier Ltd.

  10. Light speed variation from gamma ray burst GRB 160509A

    Directory of Open Access Journals (Sweden)

    Haowei Xu

    2016-09-01

    Full Text Available It is postulated in Einstein's relativity that the speed of light in vacuum is a constant for all observers. However, the effect of quantum gravity could bring an energy dependence of light speed. Even a tiny speed variation, when amplified by the cosmological distance, may be revealed by the observed time lags between photons with different energies from astrophysical sources. From the newly detected long gamma ray burst GRB 160509A, we find evidence to support the prediction for a linear form modification of light speed in cosmological space.

  11. Light speed variation from gamma ray burst GRB 160509A

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Haowei [School of Physics, State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Ma, Bo-Qiang, E-mail: mabq@pku.edu.cn [School of Physics, State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Collaborative Innovation Center of Quantum Matter, Beijing (China); Center for High Energy Physics, Peking University, Beijing 100871 (China); Center for History and Philosophy of Science, Peking University, Beijing 100871 (China)

    2016-09-10

    It is postulated in Einstein's relativity that the speed of light in vacuum is a constant for all observers. However, the effect of quantum gravity could bring an energy dependence of light speed. Even a tiny speed variation, when amplified by the cosmological distance, may be revealed by the observed time lags between photons with different energies from astrophysical sources. From the newly detected long gamma ray burst GRB 160509A, we find evidence to support the prediction for a linear form modification of light speed in cosmological space.

  12. Hourly elemental concentrations in PM2.5 aerosols sampled simultaneously at urban background and road site during SAPUSS – diurnal variations and PMF receptor modelling

    Directory of Open Access Journals (Sweden)

    M. Dall'Osto

    2013-04-01

    Full Text Available Hourly-resolved aerosol chemical speciation data can be a highly powerful tool to determine the source origin of atmospheric pollutants in urban environments. Aerosol mass concentrations of seventeen elements (Na, Mg, Al, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Sr and Pb were obtained by time (1 h and size (PM2.5 particulate matter 2.5 mass fraction simultaneously measured at the UB and RS sites: (1 the regional aerosol sources impact both monitoring sites at similar concentrations regardless their different ventilation conditions; (2 by contrast, local industrial aerosol plumes associated with shipping oil combustion and smelters activities have a higher impact on the more ventilated UB site; (3 a unique source of Pb-Cl (associated with combustion emissions is found to be the major (82% source of fine Cl in the urban agglomerate; (4 the mean diurnal variation of PM2.5 primary traffic non-exhaust brake dust (Fe-Cu suggests that this source is mainly emitted and not resuspended, whereas PM2.5 urban dust (Ca is found mainly resuspended by both traffic vortex and sea breeze; (5 urban dust (Ca is found the aerosol source most affected by land wetness, reduced by a factor of eight during rainy days and suggesting that wet roads may be a solution for reducing urban dust concentrations.

  13. Diurnal Variation and Twenty-Four Hour Sleep Deprivation Do Not Alter Supine Heart Rate Variability in Healthy Male Young Adults.

    Directory of Open Access Journals (Sweden)

    Daniel S Quintana

    Full Text Available Heart rate variability (HRV has become an increasingly popular index of cardiac autonomic control in the biobehavioral sciences due to its relationship with mental illness and cognitive traits. However, the intraindividual stability of HRV in response to sleep and diurnal disturbances, which are commonly reported in mental illness, and its relationship with executive function are not well understood. Here, in 40 healthy adult males we calculated high frequency HRV-an index of parasympathetic nervous system (PNS activity-using pulse oximetry during brain imaging, and assessed attentional and executive function performance in a subsequent behavioral test session at three time points: morning, evening, and the following morning. Twenty participants were randomly selected for total sleep deprivation whereas the other 20 participants slept as normal. Sleep deprivation and morning-to-night variation did not influence high frequency HRV at either a group or individual level; however, sleep deprivation abolished the relationship between orienting attention performance and HRV. We conclude that a day of wake and a night of laboratory-induced sleep deprivation do not alter supine high frequency HRV in young healthy male adults.

  14. Diurnal, seasonal and latitudinal variations of electron temperature measured by the SROSS C2 satellite at 500 km altitude and comparison with the IRI

    Directory of Open Access Journals (Sweden)

    P. K. Bhuyan

    2002-06-01

    Full Text Available The diurnal, seasonal and latitudinal variations of electron temperature Te, measured by the SROSS C2 satellite at equatorial and the low-latitudes during the low solar activity period of 1995–1997 are investigated. The average height of the satellite was ~ 500 km and it covered the latitude belt of –31° to 34° and the longitude range of 40°–100°. Te varies between 700–800 K during night-time (20:00–04:00 LT, rises sharply during sunrise (04:00–06:00 LT to reach a level of ~ 3500 K within a couple of hours and then falls between 07:00–10:00 LT to a daytime average value of ~ 1600 K. A secondary maximum is observed around 16:00–18:00 LT in summer. Latitudinal gradients in Te have been observed during the morning enhancement and daytime hours. Comparison of measured and International Reference Ionosphere (IRI predicted electron temperature reveals that the IRI predicts nighttime Te well within ~ 100 K of observation, but at other local times, the predicted Te is less than that measured in all seasons.Key words. Ionosphere, equatorial ionosphere, plasma temperature, and density

  15. Modification by oxazepam of the diurnal variations in brain 125I-melatonin binding sites in sham-operated and pinealectomized rats

    International Nuclear Information System (INIS)

    Anis, Y.; Zisapel, N.; Nir, I.; Schmidt, U.

    1992-01-01

    Sham-operated and pinealectomized male rats were maintained at 14 h light: 10 h dark cycles (lights-on 5.00 h) and injected daily, for 14 days, with oxazepam or vehicle. 125 I-melatonin binding was recorded in synaptosomes prepared at 10.00, 18.00, and 24.00 h from the hypothalamus, hippocampus and medulla-pons of the rats. In the sham-operated, vehicle treated rats, specific 125 I-melatonin binding in all brain areas studied was higher at 18.00 h, whereas in the oxazepam-treated animals, binding was higher at 24.00 h than at the other times tested. In the pinealectomized, vehicle-treated rats, the binding recorded at 18.00 h in all three brain areas, was lower than at the other times of day tested. Oxazepam treatment decreased 125 I-melatonin binding at 24.00 h in the hippocampus and medulla-pons of the pinealectomized rats and did not significantly affect the binding in the hypothalamus. These results indicate the ability of oxazepam, pinealectomy and their combination, to manipulate the diurnal variations in 125 I-melatonin binding sites in the rat brain

  16. Air shower array designed for cosmic ray variation measurements and high energy gamma ray astronomy

    Energy Technology Data Exchange (ETDEWEB)

    Morello, C; Navarra, G [Consiglio Nazionale delle Ricerche, Turin (Italy). Lab. di Cosmo-Geofisica

    1981-08-15

    We describe an array for performing measurements of counting rates and arrival directions of extensive air showers at primary energy E/sub 0/ approx. equal to 3 x 10/sup 9/ eV. The aim of the research is to study the time variations and the anisotropies of cosmic rays and the observable gamma ray sources in the high energy region. The installation, composed of four large area scintillation counters and completely controlled by a microcomputer system, operates at mountain altitude (3500 m a.s.l.). The preanalysis of data, stability tests and periodic calibrations are performed by on-line programs. The method for obtaining the required stability and the corrections on temperature and gain variations are also described.

  17. Relation of large-scale coronal X-ray structure and cosmic rays. Pt. 4

    International Nuclear Information System (INIS)

    Roelof, E.C.; Gold, R.E.; Krieger, A.S.; Nolte, J.T.; Venkatesan, D.

    1975-01-01

    We have studied the amplitude of the diurnal variations in the Sulphur Mountain superneutron monitor as a function of the high-coronal connection longitudine of the interplanetary field lines passing over Earth. We find that the amplitude of the diurnal variation is based toward below average values ( 0.4%) over bright regions. The results are consistent with the theoretical argument (Roelof 1975) that the diurnal variation is influenced by the ability of the corona to sustain a meridional cosmic ray gradient set up by the motional EMF in interplanetary space. (orig./WBU) [de

  18. Seasonal variations of the semi-diurnal and diurnal tides in the MLT: multi-year MF radar observations from 2–70° N, modelled tides (GSWM, CMAM

    Directory of Open Access Journals (Sweden)

    A. H. Manson

    2002-05-01

    Full Text Available In an earlier paper (Manson et al., 1999a tidal data (1990–1997 from six Medium Frequency Radars (MFR were compared with the Global Scale Wave Model (GSWM, original 1995 version. The radars are located between the equator and high northern latitudes: Christmas Island (2° N, Hawaii (22° N, Urbana (40° N, London (43° N, Saskatoon (52° N and Tromsø (70° N. Common harmonic analysis was applied, to ensure consistency of amplitudes and phases in the 75–95 km height range. For the diurnal tide, seasonal agreements between observations and model were excellent while for the semi-diurnal tide the seasonal transitions between clear solstitial states were less well captured by the model. Here the data set is increased by the addition of two locations in the Pacific-North American sector: Yamagawa 31° N, and Wakkanai 45° N. The GSWM model has undergone two additional developments (1998, 2000 to include an improved gravity wave (GW stress parameterization, background winds from UARS systems and monthly tidal forcing for better characterization of seasonal change. The other model, the Canadian Middle Atmosphere Model (CMAM which is a General Circulation Model, provides internally generated forcing (due to ozone and water vapour for the tides. The two GSWM versions show distinct differences, with the 2000 version being either closer to, or further away from, the observations than the original 1995 version. CMAM provides results dependent upon the GW parameterization scheme inserted, but one of the schemes provides very useful tides, especially for the semi-diurnal component.Key words. Meteorology and atmospheric dynamics (middle atmosphere dynamics; waves and tides

  19. Seasonal variations of the semi-diurnal and diurnal tides in the MLT: multi-year MF radar observations from 2 to 70°N, and the GSWM tidal model

    Science.gov (United States)

    Manson, A.; Meek, C.; Hagan, M.; Hall, C.; Hocking, W.; MacDougall, J.; Franke, S.; Riggin, D.; Fritts, D.; Vincent, R.; Burrage, M.

    1999-07-01

    Continuous observations of the wind field have been made by six Medium Frequency Radars (MFRs), located between the equator and high northern latitudes: Christmas Islands (2°N), Hawaii (22°N), Urbana (40°N), London (43°N), Saskatoon (52°N) and Tromsø (70°N). Data have been sought for the time interval 1990-1997, and typically 5 years of data have become available from each station, to demonstrate the level of annual consistency and variability. Common harmonic analysis is applied so that the monthly amplitudes and phases of the semi-diurnal (SD) and diurnal (D) wind oscillations are available in the height range of (typically) 75-95 km in the upper Middle Atmosphere. Comparisons are made with tides from the Global Scale Wave Model (GSWM), which are available for 3-month seasons. The emphasis is upon the monthly climatologies at each location based upon comparisons of profiles, and also latitudinal plots of amplitudes and phases at particular heights. For the diurnal tide, the agreement between observations and model is now quite excellent with modelled values frequently lying within the range of yearly values. Both observations and model demonstrate strong seasonal changes. This result is a striking improvement over the comparisons of 1989 (JATP, Special issue). In particular, the phases and phase-gradients for the non-winter months at mid- to high-latitudes are now in excellent agreement. Some of the low latitude discrepancies are attributed to the existence of non-migrating tidal components associated with tropospheric latent heat release. For the semi-diurnal tide, the observed strong transitions between clear solstitial states are less well captured by the model. There is little evidence for improvement over the promising comparisons of 1989. In particular, the late-summer/autumnal tidal maximum of mid-latitudes is observed to be larger, and with strong monthly variability. Also the summer modelled tide has unobserved short (20 km) wavelengths at high

  20. Study of long-time variations of cosmic rays

    International Nuclear Information System (INIS)

    Dergachev, V.A.

    1979-01-01

    Discussed are some problems of the investigation into the cosmic rays intensity in the past via the contents of cosmogenic isotopes in the samples of known age, mainly measuring the activity of radiocarbon in the samples dated by the dendrochronological method. The necessity of production of the multicentury dendrochronological scales with absolute dating for decoding of the information contained in the annual rings during the large time scale is pointed out. The dendrochronologic studies supplemented by the radiocarbon dating would permit to study the variations in radiocarbon content and to determine the factors, which influence this content, during large time intervals. The different factors - the solar activity, the supernovae flares et cetera - influencing the radiocarbon concentration are considered

  1. Characteristics and diurnal variations of NMHCs at urban, suburban, and rural sites in the Pearl River Delta and a remote site in South China

    Science.gov (United States)

    Tang, J. H.; Chan, L. Y.; Chan, C. Y.; Li, Y. S.; Chang, C. C.; Liu, S. C.; Wu, D.; Li, Y. D.

    The Pearl River Delta (PRD) is one of the most industrialized and urbanized regions in China. With rapid growth of the economy, it is suffering from deteriorating air quality. Non-methane hydrocarbons (NMHCs) were investigated at urban and suburban sites in Guangzhou (GZ), a rural site in PRD and a clean remote site in South China, in April 2005. Additional roadside samples in GZ and Qingxi (QX, a small industrial town in PRD), ambient air samples at the rooftop of a printing factory in QX and exhaust samples from liquefied petroleum gas (LPG)—fueled taxis in GZ were collected to help identify the source signatures of NMHCs. A large fraction of propane (47%) was found in exhaust samples from LPG-fueled taxis in GZ and extremely high levels of toluene (2.0-3.1 ppmv) were found at the rooftop of the printing factory in QX. Vehicular and industrial emissions were the main sources of NMHCs. The effect of vehicular emission on the ambient air varied among the three PRD sites. The impact of industrial emissions was widespread and they contributed greatly to the high levels of aromatic hydrocarbons, especially toluene, at the three PRD sites investigated. Leakage from vehicles fueled by LPG contributed mainly to the high levels of propane and n-butane at the urban GZ site. Ethane and ethyne from long-range transport and isoprene from local biogenic emission were the main contributors to the total hydrocarbons at the remote site. Diurnal variations of NMHCs showed that the contribution from vehicular emissions varied with traffic conditions and were more influenced by fresh emissions at the urban site and by aged air at the suburban and rural sites. Isoprene from biogenic emission contributed largely to the ozone formation potential (OFP) at the remote site. Ethene, toluene and m/ p-xylene were the main contributors to the OFP at the three PRD sites.

  2. Long-term and transient time variation of cosmic ray fluxes detected in Argentina by CARPET cosmic ray detector

    Science.gov (United States)

    De Mendonça, R. R. S.; Raulin, J.-P.; Bertoni, F. C. P.; Echer, E.; Makhmutov, V. S.; Fernandez, G.

    2011-07-01

    We present results obtained at El Leoncito (CASLEO, San Juan, Argentina) with the CARPET charged particles detector installed in April 2006. The observed modulation of the cosmic ray flux is discussed as a function of its time variability and it is related to longer solar activity variations and to shorter variations during solar and geomagnetic transient activity. Short period (few minutes, few hours) cosmic ray modulation events are observed during rain time (precipitation) and significant variations of the atmospheric electric field. Complementary observations of the atmospheric electric field indicate that its time variations play an important role in the detected cosmic ray event.

  3. Intensity variation of cosmic rays near the heliospheric current sheet

    International Nuclear Information System (INIS)

    Badruddin, K.S.; Yadav, R.S.; Yadav, N.R.

    1985-01-01

    Cosmic ray intensity variations near the heliospheric current sheet-both above and below it-have been studied during 1964-76. Superposed epoch analysis of the cosmic ray neutron monitor data with respect to sector boundaries (i.e., heliospheric current sheet crossings) has been performed. In this analysis data from neutron monitors well distributed in latitude over the Earth's surface is used. First, this study has been made during the two solar activity minimum periods 1964-65 and 1975-76, using the data from Thule (cut-off rigidity O GV), Deep River (cut-off rigidity 1.02 GV), Rome (cut-off rigidity 6.32 GV) and Huancayo (cut-off rigidity 13.45 GV) neutron monitors. The data is analyzed from Deep River, Rome and Huancayo neutron monitors, for which data is available for the full period (1964-76), by dividing the periods according to the changes in solar activity, interplanetary magnetic field polarity and coronal holes. All these studies have shown a negative gradient with respect to heliomagnetic latitude (current sheet). These results have been discussed in the light of theoretical and observational evidences. Suggestions have been given to overcome the discrepancy between the observational and theoretical results. Further, possible explanations for these observational results have been suggested. (author)

  4. Studies in cosmic rays

    International Nuclear Information System (INIS)

    Bemalkhedkar, M.M.

    1974-03-01

    The investigation of the diurnal variation in the cosmic ray intensity on individual days has revealed a new class of diurnal variation showing a maximum around 09 hour direction in the interplanetary space. It is shown to occur during the recovery phase of Forbush decreases as well as during quiet periods. The rigidity spectrum of the anomalous diurnal variation has an exponent around zero, the same as that for the average diurnal variation exhibiting maximum around 18 hours in the interplanetary space. It is shown that the Forbush decreases associated with the diurnal variation exhibiting morning maximum, are 27 day recurrent in nature and are preceded by east limb solar flares on most of the occasions. A qualitative model of the transient modulation by solar corotating corpuscular streams of enhanced solar wind velocity, emanating from the active regions on the solar disc, is proposed to explain the anomalous diurnal anisotropy in the recovery phase of 27 day recurrent Forbush decreases. From this model, the cosmic ray diffusion coefficients, parallel and perpendicular to the interplanetary magnetic field inside the corotating stream, are derived and compared with the average values. To investigate the possibility of determining the energy spectra of cosmic ray intensity variations from a single station, a continuous record of neutron multiplicity spectrum has been obtained for the period October, 1967 - October, 1971, using the Gulmarg neutron monitor. The average multiplicity spectrum in the Gulmarg neutron monitor shows a mean multiplicity approximately equal to 1.4 for 12 Boron-tri-fluoride counters and is an increasing function of the number of counters used. The mean multiplicity measured in various other neutron monitors, when normalized to the cutoff rigidity of Gulmurg (11.91 GV), shows a systematic increase with the altitude of the station. (author)

  5. One year online measurements of water-soluble ions at the industrially polluted town of Nanjing, China: Sources, seasonal and diurnal variations.

    Science.gov (United States)

    Wang, Honglei; An, Junlin; Cheng, Mengtian; Shen, Lijuan; Zhu, Bin; Li, Yi; Wang, Yuesi; Duan, Qing; Sullivan, Amy; Xia, Li

    2016-04-01

    Half-hourly mass concentrations water-soluble ions (WSIs) and PM2.5 were measured online a Rapid Collector of Fine Particles and Ion Chromatography system (RCFP-IC) and FH62C14 Continuous Particulate Monitor in Nanjing from October 18, 2013 to November 17, 2014. The WSIs concentration ranged from 7.07 to 333.42 μg m(-3) with an annual mean of 76.32 μg m(-3). The WSIs ranked in the order of SO4(2-) > NH4(+) > NO3(-) > Cl(-) > NO2(-) > K(+) > Ca(2+) > Na(+) > Mg(2+). The PM2.5 concentration ranged from 4.00 to 400 μg m(-3) with an annual mean of 83.58 μg m(-3). The concentrations of WSIs varied in the order of winter (115.77 μg m(-3)) > spring (76.10 μg m(-3)) > autumn (63.72 μg m(-3)) > summer (59.75 μg m(-3)), with the highest level in January (123.99 μg m(-3)) and lowest level in August (43.73 μg m(-3)). Different WSIs had distinct diurnal variations. The source analysis of the WSIs in the PCA/APCS mode illustrated that the sources consisted of secondary aerosol, coal combustion, mineral dust, biomass burning, traffic emissions and sea salt. In addition, there were seasonal variations amongst the various sources. The haze formation mechanism was different in summer and winter. The winter was dominated by NH4NO3 (18.56%), (NH4)2SO4 (28.63%), NH4(+) (11.27%), SO4(2-) (18.35%) and NO3(-) (13.13%), and by NH3 (25.93%), (NH4)2SO4 (13.37%), SO4(2-) (15.74%) and NO3(-) (9.97%) in summer. Consequently, the proportions of HCl, HNO3, NH4(+), SO4(2-) and NO3(-) were much larger during haze episodes in winter, while it was dominated by NH4NO3, NH4(+), (NH4)2SO4, SO4(2-) and NO3(-) during summer haze episodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

  6. Diurnal variations of ambient particulate wood burning emissions and their contribution to the concentration of Polycyclic Aromatic Hydrocarbons (PAHs) in Seiffen, Germany

    Science.gov (United States)

    Poulain, L.; Iinuma, Y.; Müller, K.; Birmili, W.; Weinhold, K.; Brüggemann, E.; Gnauk, T.; Hausmann, A.; Löschau, G.; Wiedensohler, A.; Herrmann, H.

    2011-12-01

    Residential wood burning is becoming an increasingly important cause of air quality problems since it has become a popular source of alternative energy to fossil fuel. In order to characterize the contribution of residential wood burning to local particle pollution, a field campaign was organized at the village of Seiffen (Saxony, Germany). During this campaign, an Aerosol Mass Spectrometer (AMS) was deployed in parallel to a PM1 high volume filter sampler. The AMS mass spectra were analyzed using Positive Matrix Factorization (PMF) to obtain detailed information about the organic aerosol (OA). Biomass-burning organic aerosol (BBOA), Hydrocarbon-like organic aerosol (HOA), and Oxygenated Organic Aerosol (OOA) were identified and represented 20%, 17% and 62% of total OA, respectively. Additionally, Polycyclic Aromatic Hydrocarbons (PAH) were measured by the AMS with an average concentration of 10 ng m-3 and short term events of extremely high PAH concentration (up to 500 ng m-3) compared to the mean PAH value were observed during the whole measurement period. A comparison with the results from PM1 filter samples showed that the BBOA factor and the AMS PAH are good indicators of the total concentration of the different monosaccharide anhydrides and PAH measured on the filter samples. Based on its low correlation with CO and the low car traffic, the HOA factor was considered to be related to residential heating using liquid fuel. An influence of the time of the week (week vs. weekend) on the diurnal profiles of the different OA components was observed. The weekdays were characterized by two maxima; a first one early in the morning and a stronger one in the evening. During the weekend days, the different OA components principally reached only one maximum in the afternoon. Finally, the PAH emitted directly from residential wood combustion was estimated to represent 1.5% of the total mass of the BBOA factor and around 62% of the total PAH concentration measured at

  7. Hourly elemental concentrations in PM2.5 aerosols sampled simultaneously at urban background and road site during SAPUSS - diurnal variations and PMF receptor modelling

    Science.gov (United States)

    Dall'Osto, M.; Querol, X.; Amato, F.; Karanasiou, A.; Lucarelli, F.; Nava, S.; Calzolai, G.; Chiari, M.

    2013-04-01

    combustion emissions) is found to be the major (82%) source of fine Cl in the urban agglomerate; (4) the mean diurnal variation of PM2.5 primary traffic non-exhaust brake dust (Fe-Cu) suggests that this source is mainly emitted and not resuspended, whereas PM2.5 urban dust (Ca) is found mainly resuspended by both traffic vortex and sea breeze; (5) urban dust (Ca) is found the aerosol source most affected by land wetness, reduced by a factor of eight during rainy days and suggesting that wet roads may be a solution for reducing urban dust concentrations.

  8. Diurnal variations of ambient particulate wood burning emissions and their contribution to the concentration of Polycyclic Aromatic Hydrocarbons (PAHs in Seiffen, Germany

    Directory of Open Access Journals (Sweden)

    L. Poulain

    2011-12-01

    Full Text Available Residential wood burning is becoming an increasingly important cause of air quality problems since it has become a popular source of alternative energy to fossil fuel. In order to characterize the contribution of residential wood burning to local particle pollution, a field campaign was organized at the village of Seiffen (Saxony, Germany. During this campaign, an Aerosol Mass Spectrometer (AMS was deployed in parallel to a PM1 high volume filter sampler. The AMS mass spectra were analyzed using Positive Matrix Factorization (PMF to obtain detailed information about the organic aerosol (OA. Biomass-burning organic aerosol (BBOA, Hydrocarbon-like organic aerosol (HOA, and Oxygenated Organic Aerosol (OOA were identified and represented 20%, 17% and 62% of total OA, respectively. Additionally, Polycyclic Aromatic Hydrocarbons (PAH were measured by the AMS with an average concentration of 10 ng m−3 and short term events of extremely high PAH concentration (up to 500 ng m−3 compared to the mean PAH value were observed during the whole measurement period. A comparison with the results from PM1 filter samples showed that the BBOA factor and the AMS PAH are good indicators of the total concentration of the different monosaccharide anhydrides and PAH measured on the filter samples. Based on its low correlation with CO and the low car traffic, the HOA factor was considered to be related to residential heating using liquid fuel. An influence of the time of the week (week vs. weekend on the diurnal profiles of the different OA components was observed. The weekdays were characterized by two maxima; a first one early in the morning and a stronger one in the evening. During the weekend days, the different OA components principally reached only one maximum in the afternoon. Finally, the PAH emitted directly from residential wood combustion was estimated to represent 1.5% of the total mass of the BBOA factor and

  9. Diurnal variations in incidence and outcome of out-of-hospital cardiac arrest including prior comorbidity and pharmacotherapy: a nationwide study in Denmark.

    Science.gov (United States)

    Karlsson, Lena I M; Wissenberg, Mads; Fosbøl, Emil L; Hansen, Carolina Malta; Lippert, Freddy K; Bagai, Akshay; McNally, Bryan; Granger, Christopher B; Christensen, Erika Frischknecht; Folke, Fredrik; Rajan, Shahzleen; Weeke, Peter; Nielsen, Søren L; Køber, Lars; Gislason, Gunnar H; Torp-Pedersen, Christian

    2014-09-01

    To investigate diurnal variations in incidence and outcomes following out-of-hospital cardiac arrest (OHCA). OHCA of presumed cardiac etiology were identified through the nationwide Danish Cardiac Arrest Registry (2001-2010). Time of day was divided into three time periods: daytime 07.00-14.59; evening 15.00-22.59; and nighttime 23.00-06.59. We identified 18,929 OHCA patients, aged ≥18 years. The median age was 72 years (IQR 62-80) and the majority were male (67.5%). OHCA occurrence varied across time periods, with 43.9%, 35.7% and 20.6% occurring during daytime, evening and nighttime, respectively. Nighttime patients were more likely to have: severe comorbidity (i.e. COPD), arrest in private home (87.2% vs. 69.0% and 73.0% daytime and evening, respectively), non-witnessed arrest (51.2% vs. 48.4% and 43.7%), no bystander CPR (75.9% vs. 68.4% and 66.1%), longer time interval from recognition of OHCA to rhythm analysis (12 min vs. 11 min and 11 min), and non-shockable heart rhythm (80.1% vs. 70.3% and 69.4%), all p<0.0001. Nighttime patients were less likely to achieve return of spontaneous circulation on arrival at the hospital (7.5% vs. 14.8% and 15.1%) and 1-year survival (2.8% vs. 7.2% and 7.1%), p<0.0001. Overall, the lower 1-year survival rate persisted after adjusting for patient-related and cardiac-arrest related characteristics mentioned above (OR 0.47, 95%CI 0.37-0.59; OR 0.51, 95%CI 0.40-0.65, compared to daytime and evening, respectively). We found nighttime patients to have a lower survival compared to daytime and evening that persisted when adjusting for patient-related and cardiac-arrest related characteristics including comorbidities. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Hard X-ray Variations in the Crab Nebula

    Science.gov (United States)

    Wilson-Hodge, Colleen A.; Cherry, M. L.; Case, G. L.; Baumgartner, W. H.; Beklen, E.; Bhat, P. N.; Briggs, M. S.; Camero-Arranz, A.; Connaughton, V.; Finger, M. H.; hide

    2013-01-01

    In the first two years of science operations of the Fermi Gamma-ray Burst Monitor (GBM), August 2008 to August 2010, approximately 7% (70 mcrab) decline was discovered in the overall Crab Nebula flux in the 15 - 50 keV band, measured with the Earth occultation technique. This decline was independently confirmed with four other instruments: the RXTE/PCA, Swift/BAT, INTEGRAL/IBIS, and INTEGRAL/SPI. The pulsed flux measured with RXTE/PCA from 1999-2010 was consistent with the pulsar spin-down, indicating that the observed changes were nebular. From 2001 to 2010, the Crab nebula flux measured with RXTE/ PCA was particularly variable, changing by up to approximately 3.5% per year in the 15-50 keV band. These variations were confirmed with INTEGRAL/SPI starting in 2003, Swift/BAT starting in 2005, and Fermi GBM starting in 2008. Before 2001 and since 2010, the Crab nebula flux has appeared more stable, varying by less than 2% per year. I will present updated light curves in multiple energy bands for the Crab Nebula, including recent data from Fermi GBM, Swift/BAT, INTEGRAL and MAXI, and a 16-year long light curve from RXTE/PCA.

  11. Numerical modeling of the 22-year variation of the cosmic ray intensity and anisotropy

    International Nuclear Information System (INIS)

    Kadokura, A.; Nishida, A.

    1986-01-01

    We have solved the two-dimensional time-dependent diffusion-convection equation numerically to obtain the distribution and anisotropy of cosmic rays in the heliosphere. We have assumed that the parallel and perpendicular mean free paths are proportional to the particle Larmor radius, and we have treated each proportionality constant (a,b) as a parameter. We have found that the set (a,b) = (4,2) gives the steady state solution compatible with observations on the intensity and the solar diurnal anisotropy of cosmic rays in 0.5- to 10-GeV range as obtained at the earth. This set of (a,b) corresponds to the ratio of the diffusion coefficients D/sub parallel//D/sub perpendicular/ = 10. In our solution the intensity for the (pre-1980) interplanetary magnetic field (IMF) state where the solar magnetic dipole and the angular velocity vector are parallel is higher than for the (post-1980) state where they are antiparallel, while the phase of the diurnal anisotropy is about 15 hours for the parallel state and about 18 hours for the antiparallel state. We have also reproduced the observed small radial gradient for each IMF state. We discuss the nature of the solution in order to understand the effect of the density gradient drift motion on the cosmic ray distribution

  12. Sidereal semi-diurnal variation observed at high zenith angles at Mawson, 1968-1984, and the polarity of the solar main field

    International Nuclear Information System (INIS)

    Jacklyn, R.M.; Duldig, M.L.

    1985-01-01

    High zenith-angle North/South telescopes viewing equatorially and at midlatitudes through 40 MWE of atmosphere have been operating at Mawson since early 1968. It is evident that a sidereal semi-diurnal component of galactic origin has been observed, over and above a possible spurious component proposed by Nagashima, arising from a bi-directional component of the solar anisotropy. Although a very pronounced reduction in the semi-diurnal galactic response followed the reversal of polarity of the solar main field during 1969 to 1971, so far the observations indicate that there has been no recurrence of a larger galactic response following the reversal of polarity around 1981. The possible role of the latitudional extent lambda omicron of the wavy neutral sheet is discussed

  13. Gamma ray induced fruit quality variations in banana variety Nendran (Musa Paradasiaca L.)

    International Nuclear Information System (INIS)

    Radha Devi, D.S.; Nayer, N.K.

    1992-01-01

    Gamma ray induced fruit quality variation was envisaged to analyse the direct effect of Co 60 gamma rays in banana variety Nendran. Fruit quality analysis showed that the total soluble solids and acidity decreased and total sugar and sugar acid ratio increased with increase in dose of gamma ray exposures. (author). 5 refs., 1 tab

  14. Diurnal variation in the coupling of photosynthetic electron transport and carbon fixation in iron-limited phytoplankton in the NE subarctic Pacific

    Science.gov (United States)

    Schuback, Nina; Flecken, Mirkko; Maldonado, Maria T.; Tortell, Philippe D.

    2016-02-01

    Active chlorophyll a fluorescence approaches, including fast repetition rate fluorometry (FRRF), have the potential to provide estimates of phytoplankton primary productivity at an unprecedented spatial and temporal resolution. FRRF-derived productivity rates are based on estimates of charge separation in reaction center II (ETRRCII), which must be converted into ecologically relevant units of carbon fixation. Understanding sources of variability in the coupling of ETRRCII and carbon fixation provides physiological insight into phytoplankton photosynthesis and is critical for the application of FRRF as a primary productivity measurement tool. In the present study, we simultaneously measured phytoplankton carbon fixation and ETRRCII in the iron-limited NE subarctic Pacific over the course of a diurnal cycle. We show that rates of ETRRCII are closely tied to the diurnal cycle in light availability, whereas rates of carbon fixation appear to be influenced by endogenous changes in metabolic energy allocation under iron-limited conditions. Unsynchronized diurnal oscillations of the two rates led to 3.5-fold changes in the conversion factor between ETRRCII and carbon fixation (Kc / nPSII). Consequently, diurnal variability in phytoplankton carbon fixation cannot be adequately captured with FRRF approaches if a constant conversion factor is applied. Utilizing several auxiliary photophysiological measurements, we observed that a high conversion factor is associated with conditions of excess light and correlates with the increased expression of non-photochemical quenching (NPQ) in the pigment antenna, as derived from FRRF measurements. The observed correlation between NPQ and Kc / nPSII requires further validation but has the potential to improve estimates of phytoplankton carbon fixation rates from FRRF measurements alone.

  15. Normal blood pressure and preserved diurnal variation in offspring of type 2 diabetic patients characterized by features of the metabolic syndrome: the Fredericia Study

    DEFF Research Database (Denmark)

    Foss, Anne-Catherine; Vestbo, Else; Frøland, Anders

    2000-01-01

    index (P triglycerides (P ... monitoring and compared the BP level and profile with 275 offspring of nondiabetic subjects. Anthropometric measures and cholesterol, fasting blood glucose, and insulin levels were also compared between groups. RESULTS: No significant differences in BP level (P > 0.05) or diurnal BP profile were evident...... between the nondiabetic glucose-tolerant offspring of type 2 diabetic subjects and the offspring of nondiabetic subjects. BMI (P glucose (P

  16. The Terminator Time in subionospheric VLF/LF diurnal variation as recorded by the Romanian VLF/LF radio monitoring system related to earthquake occurrence and volcano erruptions

    Science.gov (United States)

    Moldovan, I. A.; Moldovan, A. S.; Biagi, P. F.; Ionescu, C.; Schwingenschuh, K.; Boudjada, M. Y.

    2012-04-01

    The Romanian VLF/LF monitoring system consisting in a radio receiver and the infrastructure that is necessary to record and transmit the collected data is part of the European international network named INFREP. Information on electromagnetic fields' intensities created by transmitters at a receiving site are indicating the quality of the propagation along the paths between the receivers and transmitters. Studying the ionosphere's influences on the electromagnetic waves' propagation along a certain path is a method to put into evidence possible modifications of its lower structure and composition as earthquakes' precursors. The VLF/LF receiver installed in Romania was put into operation in February 2009 and has already 3 years of testing, functioning and proving its utility in the forecast of some earthquakes or volcanic eruptions. Simultaneously we monitor, in the same site with the VLF/LF receiver, the vertical atmospheric electric field and different other meteorological parameters as: temperature, pressure or rainfall. The global magnetic conditions are emphasized with the help of Daily Geomagnetic Index Kp. At a basic level, the adopted analysis consists in a simple statistical evaluation of the signals by comparing the instantaneous values to the trend of the signal. In this paper we pay attention to the terminator times in subionospheric VLF/LF diurnal variation, which are defined as the times of minimum in amplitude (or phase) around sunrise and sunset. These terminator times are found to shift significantly just around the earthquake. In the case of Kobe earthquake, there were found significant shifts in both morning and evening terminator times and these authors interpreted the shift in terminator time in terms of the lowering of lower ionosphere by using the full-wave mode theory. A LabVIEW application which accesses the VLF/LF receiver through internet was developed. This program opens the receiver's web-page and automatically retrieves the list of data

  17. Diurnal changes in photosynthetic parameters of Populus tremuloides, modulated by elevated concentrations of CO2 and/or O3 and daily climatic variation

    International Nuclear Information System (INIS)

    Kets, Katre; Darbah, Joseph N.T.; Sober, Anu; Riikonen, Johanna; Sober, Jaak; Karnosky, David F.

    2010-01-01

    The diurnal changes in light-saturated photosynthesis (Pn) under elevated CO 2 and/or O 3 in relation to stomatal conductance (g s ), water potential, intercellular [CO 2 ], leaf temperature and vapour-pressure difference between leaf and air (VPD L ) were studied at the Aspen FACE site. Two aspen (Populus tremuloides Michx.) clones differing in their sensitivity to ozone were measured. The depression in Pn was found after 10:00 h. The midday decline in Pn corresponded with both decreased g s and decreased Rubisco carboxylation efficiency, Vc max . As a result of increasing VPD L , g s decreased. Elevated [CO 2 ] resulted in more pronounced midday decline in Pn compared to ambient concentrations. Moreover, this decline was more pronounced under combined treatment compared to elevated CO 2 treatment. The positive impact of CO 2 on Pn was relatively more pronounced in days with environmental stress but relatively less pronounced during midday depression. The negative impact of ozone tended to decrease in both cases. - Diurnal and seasonal patterns of environmental stress (drought, high air temperature) affects a relative impact of elevated concentrations of CO 2 and O 3 on trees.

  18. Average features of cosmic ray variation associated with sudden commencement of magnetic storm

    International Nuclear Information System (INIS)

    Wada, Masami; Suda, Tomoshige.

    1980-01-01

    In order to obtain average features of cosmic ray variation associated with a passage of shock front in space, superposed epoch analysis of cosmic ray intensity with respect to the time of occurrence of sudden commencement (SC) of magnetic storm during solar cycle 20, 1964 - 1975, is carried out for hundreds of SC. When SC's are distributed evenly over the day, the onset in cosmic ray decrease is seen clearly within one hour of SC, followed by a sharp decrease in the intensity, but without any precursory fluctuation. The magnitude distribution and the rigidity spectrum for maximum depression show the features of Forbush decrease (FD). Superposed epoch analysis is also applied to solar wind and the interplanetary magnetic field data, and their relation to cosmic ray variation is studied. Effects of the superposition of the isotropic and anisotropic variations on the time profile of cosmic ray intensity observed at a station are discussed. (author)

  19. A statistical study of diurnal, seasonal and solar cycle variations of F-region and topside auroral upflows observed by EISCAT between 1984 and 1996

    Directory of Open Access Journals (Sweden)

    C. Foster

    Full Text Available A statistical analysis of F-region and topside auroral ion upflow events is presented. The study is based on observations from EISCAT Common Programmes (CP 1 and 2 made between 1984 and 1996, and Common Programme 7 observations taken between 1990 and 1995. The occurrence frequency of ion upflow events (IUEs is examined over the altitude range 200 to 500 km, using field-aligned observations from CP-1 and CP-2. The study is extended in altitude with vertical measurements from CP-7. Ion upflow events were identified by consideration of both velocity and flux, with threshold values of 100 m s–1 and 1013 m–2 s–1, respectively. The frequency of occurrence of IUEs is seen to increase with increasing altitude. Further analysis of the field-aligned observations reveals that the number and nature of ion upflow events vary diurnally and with season and solar activity. In particular, the diurnal distribution of upflows is strongly dependent on solar cycle. Furthermore, events identified by the velocity selection criterion dominate at solar minimum, whilst events identified by the upward field-aligned flux criterion dominated at solar maximum. The study also provides a quantitative estimate of the proportion of upflows that are associated with enhanced plasma temperature. Between 50 and 60% of upflows are simultaneous with enhanced ion temperature, and approximately 80% of events are associated with either increased F-region ion or electron temperatures.

    Key words. Ionosphere (auroral ionosphere; particle acceleration

  20. Peculiarities of the Moon variations of the neutron and meson components of cosmic rays

    International Nuclear Information System (INIS)

    Naskidashvili, B.D.; Shatashvili, L.Kh.

    1979-01-01

    Lunar variations of the neutron component of cosmic rays have been investigated individually for groups of stations of the northern hemisphere of the Earth and for groups of stations of the southern hemisphere. A dependence has been found of the amplitude and phase of the first harmonic of lunar variations in the intensity of neutron and meson components of cosmic rays on the geocentric distance of the Moon and on the epoch of solar activity. The amplitudes and phases of lunar variations were determined by the Chapman-Miller method. According to the data on the meson component of cosmic rays obtained by the Nagoya station (Japan), the amplitudes of the first harmonic of lunar daily variations point to the fact that as the Moon approaches the Earth the tidal effects do not exceed the effects of lunar gravitational forces when the Moon is at apogee

  1. Effects of soil water decline on diurnal and seasonal variations in sap flux density for differently aged Japanese cypress (Chamaecyparis obtusa trees

    Directory of Open Access Journals (Sweden)

    Kenji Tsuruta

    2014-01-01

    Full Text Available The effects of soil drought on transpiration are often neglected when predicting transpiration for forests in humid regions under the influence of the Asian monsoon. These effects have indeed been neglected for Japanese cypress, Chamaecyparis obtusa, a major plantation species in Japan and the surrounding area, probably because previous studies have reported no clear effects of soil drought on transpiration for Japanese cypress forests. However, a few studies have reported an apparent reduction in transpiration with soil drought for young Japanese cypress forests. It remains unclear whether such a reduction in transpiration is limited to young Japanese cypress forests or if it is not uncommon for mature Japanese cypress forests, which occupy a large area in Japan. To clarify this point, we conducted sap flux measurements in a year with soil drought on three differently aged Japanese cypress stands including mature (43 years old and relatively young (23 and 26 years old trees. In a diurnal time scale, a cross correlation analysis of sap flux density (Fd and vapor pressure deficit (VPD showed that the time lags between Fd and VPD were 1-3 h in dry soil conditions. These were larger than those of wet soil conditions (<1 h for all sample trees. Fd at a given VPD in dry soil conditions was smaller than that in wet soil conditions for all sample trees; a 28%–63% reduction in the rate of change in Fd was observed under dry soil conditions. Because our results were obtained when the non-exceedance probability of recorded monthly precipitation was 9%–18%, the results suggest the need to consider the effects of soil drought more extensively. Those effects should be considered for not only relatively young but also mature Japanese cypress when predicting diurnal and seasonal patterns of transpiration in years with soil drought, and when predicting inter-annual patterns of transpiration for Japanese cypress despite humid

  2. Pulse-to-pulse variations in accreting X-ray pulsars

    Directory of Open Access Journals (Sweden)

    Kretschmar Peter

    2014-01-01

    Full Text Available In most accreting X-ray pulsars, the periodic signal is very clear and easily shows up as soon as data covering sufficient pulse periods (a few ten are available. The mean pulse profile is often quite typical for a given source and with minor variations repeated and recognisable across observations done years or even decades apart. At the time scale of individual pulses, significant pulse-to-pulse variations are commonly observed. While at low energies some of these variations might be explained by absorption, in the hard X-rays they will reflect changes in the accretion and subsequent emission. The amount of these variations appears to be quite different between sources and contains information about the surrounding material as well ass possibly interactions at the magnetosphere. We investigate such variations for a sample of well-known sources.

  3. Influence of Biomass Burning on Temporal and Diurnal Variations of Acidic Gases, Particulate Nitrate, and Sulfate in a Tropical Urban Atmosphere

    Directory of Open Access Journals (Sweden)

    Sailesh N. Behera

    2014-01-01

    Full Text Available The present study investigated the temporal and diurnal distributions of atmospheric acidic gases (sulphur dioxide (SO2, nitrous acid (HONO, and nitric acid (HNO3 and those of particulate nitrate (NO3- and sulfate (SO42- through a comprehensive field campaign during the largest smoke haze episode in Singapore, a representative country in Southeast Asia (SEA. To identify the atmospheric behavior of these pollutants during the smoke haze period, the data generated from the measurement campaign were divided into three distinct periods: prehaze, during haze, and posthaze periods. The 24 hr average data indicated that ambient SO2, HONO, and HNO3 during the smoke haze episodes increased by a factor ranging from 1.2 to 2.6 compared to those during the prehaze and posthaze periods. Similarly, in the case of particulates SO42- and NO3-, the factor ranged from 2.3 to 4.2. Backward air trajectories were constructed and used to find the sources of biomass burning to the recurring smoke haze in this region. The air trajectory analysis showed that the smoke haze episodes experienced in Singapore were influenced by transboundary air pollution, caused by severe biomass burning events in the islands of Indonesia.

  4. Algal grazing by the planktonic copepods Centropages hamatus and Pseudocalanus sp.: Diurnal and seasonal variation during the spring phytoplankton bloom in the Øresund Denmark

    DEFF Research Database (Denmark)

    Nicolajsen, Hanne; Møhlenberg, Flemming; Kiørboe, Thomas

    1983-01-01

    Seasonal and diel variation in rate of algal grazing were estimated from measurements of gut content (plant pigments) and gut turnover in the copepods C. hamatus and Pseudocalanus sp. during spring (Jan.-May) in the Oresund. Both species exhibited significant diel variation in gut content...

  5. Measurement of hepatic sterol synthesis in the Mongolian gerbil in vivo using [3H]water: diurnal variation and effect of type of dietary fat

    International Nuclear Information System (INIS)

    Mercer, N.J.; Holub, B.J.

    1981-01-01

    The hepatic synthesis of sterol was measured in the male Mongolian gerbil (Meriones unguiculatus) in vivo following the administration of [ 3 H]water by monitoring the incorporation of radioactivity into digitonin-precipitable sterol. A diurnal rhythm in cholesterol synthesis was exhibited under conditions of ad libitum feeding with alternating 12-hour periods of light (0200 to 1400 hr) and dark (1400 to 0200 hr). The zenith was reached between 1500 and 2100 hr and the nadir approximately 10-12 hours later between 0200 and 0400 hr, which provided a zenith/nadir ratio of 9.6 to 1.0. The in vivo rates of hepatic sterol synthesis and plasma cholesterol levels were measured in gerbils fed semi-purified diets containing either 19.5% beef tallow + 0.5% safflower, 20% lard, or 20% safflower oil and widely differing ratios of polyunsaturated: saturated fatty acids. All diets were equalized to contain 0.01% cholesterol and 0.05% plant sterol. After 3 days on the experimental diets, the mean rates of cholesterol synthesis (nmol/g liver per hr) were 41.5, 26.6, and 13.8 for animals fed the diets containing beef tallow, lard, and safflower oil, respectively. After 7 and 14 days, synthetic rates were lowest in the gerbils fed safflower oil as were also the plasma cholesterol levels. These results indicate that the type of dietary lipid can significantly influence the in vivo rate of sterol biosynthesis in gerbil liver. This response may contribute, at least in part, to the observed differences in plasma cholesterol levels

  6. Boreal lakes moderate seasonal and diurnal temperature variation and perturb atmospheric circulation: Analyses in the Community Earth System Model 1 (CESM1)

    Energy Technology Data Exchange (ETDEWEB)

    Subin, Zachary M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Murphy, Lisa N. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Li, Fiyu [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.; Bonfils, Celine [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Program for Climate Model Diagnosis and Intercomparison; Riley, William J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Div.

    2012-01-15

    We used a lake thermal physics model recently coupled into the Community Earth System Model 1 (CESM1) to study the effects of lake distribution in present and future climate. Under present climate, correcting the large underestimation of lake area in CESM1 (denoted CCSM4 in the configuration used here) caused 1 °C spring decreases and fall increases in surface air temperature throughout large areas of Canada and the US. Simulated summer surface diurnal air temperature range decreased by up to 4 °C, reducing CCSM4 biases. These changes were much larger than those resulting from prescribed lake disappearance in some present-day permafrost regions under doubled-CO2 conditions. Correcting the underestimation of lake area in present climate caused widespread high-latitude summer cooling at 850 hPa. Significant remote changes included decreases in the strength of fall Southern Ocean westerlies. We found significantly different winter responses when separately analysing 45-yr subperiods, indicating that relatively long simulations are required to discern the impacts of surface changes on remote conditions. We also investigated the surface forcing of lakes using idealised aqua-planet experiments which showed that surface changes of 2 °C in the Northern Hemisphere extra-tropics could cause substantial changes in precipitation and winds in the tropics and Southern Hemisphere. Shifts in the Inter-Tropical Convergence Zone were opposite in sign to those predicted by some previous studies. Zonal mean circulation changes were consistent in character but much larger than those occurring in the lake distribution experiments, due to the larger magnitude and more uniform surface forcing in the idealised aqua-planet experiments.

  7. Boreal lakes moderate seasonal and diurnal temperature variation and perturb atmospheric circulation: analyses in the Community Earth System Model 1 (CESM1

    Directory of Open Access Journals (Sweden)

    William J. Riley

    2012-02-01

    Full Text Available We used a lake thermal physics model recently coupled into the Community Earth System Model 1 (CESM1 to study the effects of lake distribution in present and future climate. Under present climate, correcting the large underestimation of lake area in CESM1 (denoted CCSM4 in the configuration used here caused 1 °C spring decreases and fall increases in surface air temperature throughout large areas of Canada and the US. Simulated summer surface diurnal air temperature range decreased by up to 4 °C, reducing CCSM4 biases. These changes were much larger than those resulting from prescribed lake disappearance in some present-day permafrost regions under doubled-CO2 conditions. Correcting the underestimation of lake area in present climate caused widespread high-latitude summer cooling at 850 hPa. Significant remote changes included decreases in the strength of fall Southern Ocean westerlies. We found significantly different winter responses when separately analysing 45-yr subperiods, indicating that relatively long simulations are required to discern the impacts of surface changes on remote conditions. We also investigated the surface forcing of lakes using idealised aqua-planet experiments which showed that surface changes of 2 °C in the Northern Hemisphere extra-tropics could cause substantial changes in precipitation and winds in the tropics and Southern Hemisphere. Shifts in the Inter-Tropical Convergence Zone were opposite in sign to those predicted by some previous studies. Zonal mean circulation changes were consistent in character but much larger than those occurring in the lake distribution experiments, due to the larger magnitude and more uniform surface forcing in the idealised aqua-planet experiments.

  8. Influences of early shift work on the diurnal cortisol rhythm, mood and sleep: within-subject variation in male airline pilots.

    Science.gov (United States)

    Bostock, Sophie; Steptoe, Andrew

    2013-04-01

    We aimed to investigate how early and late work shifts influenced the diurnal cortisol rhythm using a within-subjects study design. Participants were 30 healthy male non-smoking pilots, mean age 39.4, employed by a short-haul airline. The standard rotating shift pattern consisted of 5 early shifts (starting before 0600 h), followed by 3 rest days, 5 late shifts (starting after 1200 h) and 4 rest days. Pilots sampled saliva and completed subjective mood ratings in a logbook 6 times over the day on two consecutive early shift days, two late days and two rest days. Sampling was scheduled at waking, waking+30 m, waking+2.5 h, waking+8 h, waking+12 h and bedtime. Waking time, sleep duration, sleep quality and working hours were also recorded. Cortisol responses were analysed with repeated measures analysis of variance with shift condition (early, late, rest) and sample time (1-6) as within-subject factors. Early shifts were associated with a higher cortisol increase in response to awakening (CAR(i)), a greater total cortisol output over the day (AUC(G)) and a slower rate of decline over the day than late shifts or rest days. Early shifts were also associated with shorter sleep duration but co-varying for sleep duration did not alter the effects of shift on the cortisol rhythm. Both types of work shift were associated with more stress, tiredness and lower happiness than rest days, but statistical adjustment for mood ratings did not alter the findings. Early shift days were associated with significantly higher levels of circulating cortisol during waking hours than late shifts or rest days. Copyright © 2012 Elsevier Ltd. All rights reserved.

  9. Long-term variations in the gamma-ray background on SMM

    Science.gov (United States)

    Kurfess, J. D.; Share, G. H.; Kinzer, R. L.; Johnson, W. N.; Adams, J. H., Jr.

    1989-01-01

    Long-term temporal variations in the various components of the background radiation detected by the gamma-ray spectrometer on the Solar Maximum Mission are presented. The SMM gamma-ray spectrometer was launched in February, 1980 and continues to operate normally. The extended period of mission operations has provided a large data base in which it is possible to investigate a variety of environmental and instrumental background effects. In particular, several effects associated with orbital precession are introduced and discussed.

  10. Diurnal variability of Synechococcus abundance in Sagami Bay, Japan

    Digital Repository Service at National Institute of Oceanography (India)

    Mitbavkar, S.; Saino, T.

    Synechococcus, the most dominant picophytoplankton in coastal regions, exhibits diurnal variations in the open ocean. The aim of this study was to assess its short-term population dynamics and cell cycle phases through DNA analysis in a coastal...

  11. Modulation of galactic cosmic ray anisotropy in heliomagnetosphere: average sidereal daily variation

    International Nuclear Information System (INIS)

    Nagashima, K.; Morishita, I.; Yasue, S.

    1982-01-01

    The modulation of galactic anisotropy of cosmic rays caused by their deflection in the heliomagnetosphere is formulated. According to the formulation, the average sidereal i-th (2=1,2...) harmonic daily variation produced [from the anisotropy from an arbitrary direction can be expressed] by a linear combination of three basic vectors for unidirectional anisotropy and five basic vectors for bi-directional anisotropy. The general characteristics and main features of the sidereal daily variations in the modulation of the cosmic ray anistropy are presented. (U.K.)

  12. Modeling the diurnal tide with dissipation derived from UARS/HRDI measurements

    Directory of Open Access Journals (Sweden)

    M. A. Geller

    1997-09-01

    Full Text Available This paper uses dissipation values derived from UARS/HRDI observations in a recently published diurnal-tide model. These model structures compare quite well with the UARS/HRDI observations with respect to the annual variation of the diurnal tidal amplitudes and the size of the amplitudes themselves. It is suggested that the annual variation of atmospheric dissipation in the mesosphere-lower thermosphere is a major controlling factor in determining the annual variation of the diurnal tide.

  13. Extrapolating cosmic ray variations and impacts on life: Morlet wavelet analysis

    Science.gov (United States)

    Zarrouk, N.; Bennaceur, R.

    2009-07-01

    Exposure to cosmic rays may have both a direct and indirect effect on Earth's organisms. The radiation may lead to higher rates of genetic mutations in organisms, or interfere with their ability to repair DNA damage, potentially leading to diseases such as cancer. Increased cloud cover, which may cool the planet by blocking out more of the Sun's rays, is also associated with cosmic rays. They also interact with molecules in the atmosphere to create nitrogen oxide, a gas that eats away at our planet's ozone layer, which protects us from the Sun's harmful ultraviolet rays. On the ground, humans are protected from cosmic particles by the planet's atmosphere. In this paper we give estimated results of wavelet analysis from solar modulation and cosmic ray data incorporated in time-dependent cosmic ray variation. Since solar activity can be described as a non-linear chaotic dynamic system, methods such as neural networks and wavelet methods should be very suitable analytical tools. Thus we have computed our results using Morlet wavelets. Many have used wavelet techniques for studying solar activity. Here we have analysed and reconstructed cosmic ray variation, and we have better depicted periods or harmonics other than the 11-year solar modulation cycles.

  14. Diurnal blood pressure changes.

    Science.gov (United States)

    Asayama, Kei; Satoh, Michihiro; Kikuya, Masahiro

    2018-05-23

    The definition of diurnal blood pressure changes varies widely, which can be confusing. Short-term blood pressure variability during a 24-h period and the dipping status of diurnal blood pressure can be captured by ambulatory blood pressure monitoring, and these metrics are reported to have prognostic significance for cardiovascular complications. Morning blood pressure surge also indicates this risk, but its effect may be limited to populations with specific conditions. Meanwhile, the combined use of conventional office blood pressure and out-of-office blood pressure allows us to identify people with white-coat and masked hypertension. Current home devices can measure nocturnal blood pressure during sleep more conveniently than ambulatory monitoring; however, we should pay attention to blood pressure measurement conditions regardless of whether they are in a home, ambulatory, or office setting. The relatively poor reproducibility of diurnal blood pressure changes, including the nocturnal fall of blood pressure, is another underestimated issue to be addressed. Although information on diurnal blood pressure changes is expected to be used more effectively in the future, we should also keep in mind that blood pressure levels have remained central to the primary and secondary prevention of blood pressure-related cardiovascular diseases in clinical practice.

  15. Diurnal variations of organic molecular tracers and stable carbon isotopic composition in atmospheric aerosols over Mt. Tai in the North China Plain: an influence of biomass burning

    Directory of Open Access Journals (Sweden)

    P. Q. Fu

    2012-09-01

    Full Text Available Organic tracer compounds, as well as organic carbon (OC, elemental carbon (EC, water-soluble organic carbon (WSOC, and stable carbon isotope ratios (δ13C of total carbon (TC have been investigated in aerosol samples collected during early and late periods of the Mount Tai eXperiment 2006 (MTX2006 field campaign in the North China Plain. Total solvent-extractable fractions were investigated by gas chromatography/mass spectrometry. More than 130 organic compounds were detected in the aerosol samples. They were grouped into twelve organic compound classes, including biomass burning tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA tracers, and anthropogenic tracers such as phthalates, hopanes and polycyclic aromatic hydrocarbons (PAHs. In early June when the field burning activities of wheat straws in the North China Plain were very active, the total identified organics (2090 ± 1170 ng m−3 were double those in late June (926 ± 574 ng m−3. All the compound classes were more abundant in early June than in late June, except phthalate esters, which were higher in late June. Levoglucosan (88–1210 ng m−3, mean 403 ng m−3 was found as the most abundant single compound in early June, while diisobutyl phthalate was the predominant species in late June. During the biomass-burning period in early June, the diurnal trends of most of the primary and secondary organic aerosol tracers were characterized by the concentration peaks observed at mid-night or in early morning, while in late June most of the organic species peaked in late afternoon. This suggests that smoke plumes from biomass burning can uplift the aerosol particulate matter to a certain altitude, which could be further transported to and encountered the summit of Mt. Tai during nighttime. On the basis of the tracer-based method for the estimation of biomass-burning OC, fungal-spore OC and biogenic secondary

  16. Diurnal variations of organic molecular tracers and stable carbon isotopic composition in atmospheric aerosols over Mt. Tai in the North China Plain: an influence of biomass burning

    Science.gov (United States)

    Fu, P. Q.; Kawamura, K.; Chen, J.; Li, J.; Sun, Y. L.; Liu, Y.; Tachibana, E.; Aggarwal, S. G.; Okuzawa, K.; Tanimoto, H.; Kanaya, Y.; Wang, Z. F.

    2012-09-01

    Organic tracer compounds, as well as organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and stable carbon isotope ratios (δ13C) of total carbon (TC) have been investigated in aerosol samples collected during early and late periods of the Mount Tai eXperiment 2006 (MTX2006) field campaign in the North China Plain. Total solvent-extractable fractions were investigated by gas chromatography/mass spectrometry. More than 130 organic compounds were detected in the aerosol samples. They were grouped into twelve organic compound classes, including biomass burning tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA) tracers, and anthropogenic tracers such as phthalates, hopanes and polycyclic aromatic hydrocarbons (PAHs). In early June when the field burning activities of wheat straws in the North China Plain were very active, the total identified organics (2090 ± 1170 ng m-3) were double those in late June (926 ± 574 ng m-3). All the compound classes were more abundant in early June than in late June, except phthalate esters, which were higher in late June. Levoglucosan (88-1210 ng m-3, mean 403 ng m-3) was found as the most abundant single compound in early June, while diisobutyl phthalate was the predominant species in late June. During the biomass-burning period in early June, the diurnal trends of most of the primary and secondary organic aerosol tracers were characterized by the concentration peaks observed at mid-night or in early morning, while in late June most of the organic species peaked in late afternoon. This suggests that smoke plumes from biomass burning can uplift the aerosol particulate matter to a certain altitude, which could be further transported to and encountered the summit of Mt. Tai during nighttime. On the basis of the tracer-based method for the estimation of biomass-burning OC, fungal-spore OC and biogenic secondary organic carbon (SOC), we estimate that an average of 24% (up to 64%) of the

  17. Diurnal variations of organic molecular tracers and stable carbon isotopic compositions in atmospheric aerosols over Mt. Tai in North China Plain: an influence of biomass burning

    Science.gov (United States)

    Fu, P. Q.; Kawamura, K.; Chen, J.; Li, J.; Sun, Y. L.; Liu, Y.; Tachibana, E.; Aggarwal, S. G.; Okuzawa, K.; Tanimoto, H.; Kanaya, Y.; Wang, Z. F.

    2012-04-01

    Organic tracer compounds of tropospheric aerosols, as well as organic carbon (OC), elemental carbon (EC), water-soluble organic carbon (WSOC), and stable carbon isotope ratios (δ13C) of total carbon (TC) have been investigated for aerosol samples collected during early and late periods of Mount Tai eXperiment 2006 (MTX2006) field campaign in North China Plain. Total solvent extracts were investigated by gas chromatography/mass spectrometry. More than 130 organic compounds were detected in the aerosol samples. They were grouped into twelve organic compound classes, including biomass burning tracers, biogenic primary sugars, biogenic secondary organic aerosol (SOA) tracers, and anthropogenic tracers such as phthalates, hopanes and polycyclic aromatic hydrocarbons (PAHs). In early June when the field burning activities of wheat straws in North China Plain were very active, the total identified organics (2090 ± 1170 ng m-3) were double those in late June (926 ± 574 ng m-3). All the compound classes were more abundant in early June than in late June, except phthalate esters, which were higher in late June. Levoglucosan (88-1210 ng m-3, 403 ng m-3) was found as the most abundant single compound in early June, while diisobutyl phthalate was the predominant species in late June. During the biomass-burning period in early June, the diurnal trends of most of the primary and secondary organic aerosol tracers were characterized by the concentration peaks observed at mid-night or in early morning, while in late June most of the organic species peaked in late afternoon. This suggests that smoke plumes from biomass burning can uplift the aerosol particulate matter to a certain altitude and then transported to and encountered the summit of Mt. Tai during nighttime. On the basis of the tracer-based method for the estimation of biomass-burning OC, fungal-spore OC and biogenic secondary organic carbon (SOC), we estimate that an average of 24% (up to 64%) of the OC in the Mt. Tai

  18. Secular variation of cosmic ray intensity recorded in the radiocarbon concentration of tree rings

    International Nuclear Information System (INIS)

    Kigoshi, K.

    1978-01-01

    Study of the secular variations of cosmic ray intensity on the basis of the secular variations of atmospheric radiocarbon concentration in 8000 years is considered. The data on the radiocarbon concentration is received by three laboratories using the dendrochronologically dated tree ring samples. In order to use the data the variations due to geochemical process must be eliminated. From this point of view the climatic effect on the atmospheric radiocarbon concenttration is estimated using the data on sunspot number and global surface temperature during 1650-1800 y. The barge influence of climate on the atmospheric radiocarbon concentration syggests the small contribution of change of radiocarbon production rate to the short-period fluctuations in the atmospheric radiocarbon concentration. Elimination of variations caused by climate and sunspot activities from the variations in atmospheric radiocarbon concentration gives a long-term scale of its concentration which agrees well to the observed paleo-geomagnetic data

  19. X-ray speckle contrast variation at a sample-specific absorption edges

    International Nuclear Information System (INIS)

    Retsch, C. C.; Wang, Y.; Frigo, S. P.; Stephenson, G. B.; McNulty, I.

    2000-01-01

    The authors measured static x-ray speckle contrast variation with the incident photon energy across sample-specific absorption edges. They propose that the variation depends strongly on the spectral response function of the monochromator. Speckle techniques have been introduced to the x-ray regime during recent years. Most of these experiments, however, were done at photon energies above 5 keV. They are working on this technique in the 1 to 4 keV range, an energy range that includes many important x-ray absorption edges, e.g., in Al, Si, P, S, the rare-earths, and others. To their knowledge, the effect of absorption edges on speckle contrast has not yet been studied. In this paper, they present their initial measurements and understanding of the observed phenomena

  20. Basal levels and diurnal variations of some hormones and metabolites in blood of dairy cows treated daily with rbSTin early and late lactation

    Directory of Open Access Journals (Sweden)

    Jurgen Blum

    2010-01-01

    Full Text Available The variations of basal value (before morning feeding at 3-4 days interval and daily pattern (on 4and 18day of treat-  ment with 8 blood collections within 24h of hormones and metabolites were studied in four dairy cows; 2 in early and  2 in late lactation, which were alternatively injected daily for a period of 21 days with 26.3 mg rbST or saline.  The rbST  injection significantly increased the basal and daily levels of GH, IGF-I in both stages of lactation. Daily levels of NEFA  were significantly increased by rbST in both stages of lactation and their variations, due to the effect of meals, were coun-  teracted by the rbST; the higher level of NEFA allowed a greater sparing of glucose, the blood level of which resulted  higher (P  blood urea level (P  ticular the high availability of glucose, determined a significantly higher blood level of insulin and T3, and lower level of  glucagon. Despite the similar GH, IGF-I and NEFA increases observed in the cows treated in early and late lactation, other  metabolic and endocrine consequences resulted more evident in late lactation. Furthermore, some of these variations  were affected by the forage meals. It can be concluded, therefore, that the changes occurring in the blood subsequent  to a rbST treatment are not equal to those which occur at the start of lactation; moreover, they are affected by the daily  feeding pattern and perhaps by the stage of  lactation. 

  1. Comparison Of Optical, UV, X-ray, And Gamma-ray Variations Of Selected Blazars In 2011

    Science.gov (United States)

    Consiglio, Santina; Marscher, A. P.; Jorstad, S. G.; Walker, G.

    2012-01-01

    We present multi-wavelength observations of several gamma-ray bright blazars. We combine optical data obtained at Maria Mitchell Observatory on Nantucket Island with space- and ground-based observations carried out with a variety of instruments. These include a number of other optical telescopes, the Fermi Gamma-ray Space Telescope at photon energies of 0.1-200 GeV, the Rossi X-Ray Timing Explorer at 2.4-10 keV, and the Swift satellite at 0.3-10 keV plus optical and UV wavelengths. Three of the observed blazars proved to be particularly active - BL Lac, 3C 279, and PKS 1510-089. BL Lac was of special interest, varying greatly in optical brightness from night to night. In addition, as reported by the VERITAS group, it exhibited a remarkable, short-lived flare at TeV gamma-ray energies on one of the nights. We cross-correlate the variations in the different wavebands in an effort to guide theoretical interpretations of the optical and high-energy emission from blazars. This project was supported by NSF/REU grant AST-0851892 and by the Nantucket Maria Mitchell Association. The research at Boston University was supported in part by NSF grants AST-0907893, and by NASA through Fermi grants NNX08AV65G and NNX11AQ03G.

  2. Solar cycle variation of cosmic ray intensity along with interplanetary and solar wind plasma parameters

    International Nuclear Information System (INIS)

    Mishra, R.K.; Tiwari, S.; Agarwal, R.

    2008-01-01

    Galactic cosmic rays are modulated at their propagation in the heliosphere by the effect of the large-scale structure of the interplanetary medium. A comparison of the variations in the cosmic ray intensity data obtained by neutron monitoring stations with those in geomagnetic disturbance, solar wind velocity (V), interplanetary magnetic field (B), and their product (V , B) near the Earth for the period 1964-2004 has been presented so as to establish a possible correlation between them. We used the hourly averaged cosmic ray counts observed with the neutron monitor in Moscow. It is noteworthy that a significant negative correlation has been observed between the interplanetary magnetic field, product (V , B) and cosmic ray intensity during the solar cycles 21 and 22. The solar wind velocity has a good positive correlation with cosmic ray intensity during solar cycle 21, whereas it shows a weak correlation during cycles 20, 22 and 23. The interplanetary magnetic field shows a weak negative correlation with cosmic rays for solar cycle 20, and a good anti-correlation for solar cycles 21-23 with the cosmic ray intensity, which, in turn, shows a good positive correlation with disturbance time index (Dst) during solar cycles 21 and 22, and a weak correlation for cycles 20 and 23. (Authors)

  3. Diurnal variations in H{sub 2}O{sub 2}, O{sub 3}, PAN, HNO{sub 3} and aldehyde concentrations and NO/NO{sub 2} ratios at Rishiri Island, Japan: Potential influence from iodine chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kanaya, Yugo [Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan)]. E-mail: yugo@jamstec.go.jp; Tanimoto, Hiroshi [National Institute for Environmental Studies, Tsukuba (Japan); Matsumoto, Jun [Integrated Research Institute, Tokyo Institute of Technology, Yokohama (Japan); Furutani, Hiroshi [Department of Chemistry and Biochemistry, University of California, San Diego (United States); Hashimoto, Shigeru [National Institute for Environmental Studies, Tsukuba (Japan); Komazaki, Yuichi [Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan); Tanaka, Shigeru [Department of Applied Chemistry, Keio University, Yokohama (Japan); Yokouchi, Yoko [National Institute for Environmental Studies, Tsukuba (Japan); Kato, Shungo [Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, Hachioji (Japan); Kajii, Yoshizumi [Department of Applied Chemistry, Graduate School of Engineering, Tokyo Metropolitan University, Hachioji (Japan); Akimoto, Hajime [Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology, 3173-25 Showa-machi, Kanazawa-ku, Yokohama, Kanagawa 236-0001 (Japan)

    2007-04-15

    The presence of iodine chemistry, hypothesized due to the overprediction of HO{sub 2} levels by a photochemical box model at Rishiri Island in June 2000, was quantitatively tested against the observed NO/NO{sub 2} ratios and the net production rates of ozone. The observed NO/NO{sub 2} ratios were reproduced reasonably well by considering the conversion of NO to NO{sub 2} by IO, whose amount was calculated so as to reproduce the observed HO{sub 2} levels. However, the net production rates of ozone were calculated to be negative when such high mixing ratios of IO were considered, which was inconsistent with the observed buildup of ozone during daytime. These results suggest that iodine chemistry may not be the sole mechanism for the reduced mixing ratios of HO{sub 2}, or that 'hot spots' for iodine chemistry were present. Diurnal variations in the mixing ratios of HCHO, CH{sub 3}CHO, peroxy acetyl nitrate (PAN) and HNO{sub 3} observed during the study are presented along with the simulated ones. The box model simulations suggest that the effect of iodine chemistry on these concentrations is small and that important sources of CH{sub 3}CHO and sinks of PAN are probably missing from our current understanding of the tropospheric chemistry mechanism.

  4. Diurnal variations in H2O2, O3, PAN, HNO3 and aldehyde concentrations and NO/NO2 ratios at Rishiri Island, Japan: Potential influence from iodine chemistry

    International Nuclear Information System (INIS)

    Kanaya, Yugo; Tanimoto, Hiroshi; Matsumoto, Jun; Furutani, Hiroshi; Hashimoto, Shigeru; Komazaki, Yuichi; Tanaka, Shigeru; Yokouchi, Yoko; Kato, Shungo; Kajii, Yoshizumi; Akimoto, Hajime

    2007-01-01

    The presence of iodine chemistry, hypothesized due to the overprediction of HO 2 levels by a photochemical box model at Rishiri Island in June 2000, was quantitatively tested against the observed NO/NO 2 ratios and the net production rates of ozone. The observed NO/NO 2 ratios were reproduced reasonably well by considering the conversion of NO to NO 2 by IO, whose amount was calculated so as to reproduce the observed HO 2 levels. However, the net production rates of ozone were calculated to be negative when such high mixing ratios of IO were considered, which was inconsistent with the observed buildup of ozone during daytime. These results suggest that iodine chemistry may not be the sole mechanism for the reduced mixing ratios of HO 2 , or that 'hot spots' for iodine chemistry were present. Diurnal variations in the mixing ratios of HCHO, CH 3 CHO, peroxy acetyl nitrate (PAN) and HNO 3 observed during the study are presented along with the simulated ones. The box model simulations suggest that the effect of iodine chemistry on these concentrations is small and that important sources of CH 3 CHO and sinks of PAN are probably missing from our current understanding of the tropospheric chemistry mechanism

  5. The Variable Crab Nebula: Evidence for a Connection Between GeV Flares and Hard X-ray Variations

    Science.gov (United States)

    Wilson-Hodge, Colleen A.; Harding, A. K.; Hays, E. A.; Cherry, M. L.; Case, G. L.; Finger, M. H.; Jenke, P.; Zhang, X.

    2016-01-01

    In 2010, hard X-ray variations (Wilson-Hodge et al. 2011) and GeV flares (Tavani et al 2011, Abdo et al. 2011) from the Crab Nebula were discovered. Connections between these two phenomena were unclear, in part because the timescales were quite different, with yearly variations in hard X-rays and hourly to daily variations in the GeV flares. The hard X-ray flux from the Crab Nebula has again declined since 2014, much like it did in 2008-2010. During both hard X-ray decline periods, the Fermi LAT detected no GeV flares, suggesting that injection of particles from the GeV flares produces the much slower and weaker hard X-ray variations. The timescale for the particles emitting the GeV flares to lose enough energy to emit synchrotron photons in hard X-rays is consistent with the yearly variations observed in hard X-rays and with the expectation that the timescale for variations slowly increases with decreasing energy. This hypothesis also predicts even slower and weaker variations below 10 keV, consistent with the non-detection of counterparts to the GeV flares by Chandra (Weisskopf et al 2013). We will present a comparison of the observed hard X-ray variations and a simple model of the decay of particles from the GeV flares to test our hypothesis.

  6. The influence of work- and home-related stress on the levels and diurnal variation of ambulatory blood pressure and neurohumoral factors in employed women.

    Science.gov (United States)

    Kario, Kazuomi; James, Gary D; Marion, RoseMerie; Ahmed, Mustafa; Pickering, Thomas G

    2002-07-01

    The purpose of this study was to examine the effects of self-reported perceived stress at work and home on the levels, variation and co-variation of ambulatory blood pressure (BP), pulse rate (PR) and urinary catecholamine, cortisol, and aldosterone excretion measured at work, home and during sleep in women employed outside the home. The subjects of the study were 134 women (mean age 34.4 +/- 9.6 years, range 18 to 64 years) who were employed in managerial, technical or clerical positions at the same work place. Perceived stress at work and home was self-reported on a scale from 0 (low) to 10 (high). BP, PR and the urinary rates of excretion of epinephrine, norepinephrine, cortisol and aldosterone were averaged in the daily work environment from 11 AM to 3 PM, in the daily home environment from approximately 6 PM to 10 PM, and during sleep from approximately 10 PM to 6 AM the following morning. The results showed that systolic and diastolic BP (SBP and DBP) and the rates of urinary catecholamine, cortisol, and aldosterone excretion measured in the work environment were significantly higher than corresponding measurements taken in the home environment. SBP measured at work was also positively correlated with the difference in perceived stress between work and home (p home environment were positively correlated with stress at home. When the subjects were divided into groups based on whether the work or home environment was perceived to be most stressful, women reporting greater stress at work (n=85) had higher work SBP (p work DBP (p home environment to be more stressful (n=34). There were no differences in the urinary hormonal excretion rates between these perceived-stress groups. Among women with greater perceived stress at home, the home-stress score was positively correlated with sleep SBP level (r = 0.310, p home pulse rate ( r= 0.414, p work stress may increase ambulatory BP levels throughout the day, while home stress may induce additional sympathetic

  7. Model independent result on possible diurnal effect in DAMA/LIBRA-phase1

    Energy Technology Data Exchange (ETDEWEB)

    Bernabei, R.; D' Angelo, S.; Di Marco, A. [Universita di Roma ' ' Tor Vergata' ' , Dipt. di Fisica, Rome (Italy); INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Belli, P. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Cappella, F.; D' Angelo, A.; Prosperi, D. [Universita di Roma ' ' La Sapienza' ' , Dipt. di Fisica, Rome (Italy); INFN, Sezione Roma, Rome (Italy); Caracciolo, V.; Castellano, S.; Cerulli, R. [INFN, Laboratori Nazionali del Gran Sasso, Assergi (Italy); Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G. [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); Incicchitti, A. [INFN, Sezione Roma, Rome (Italy); Montecchia, F. [INFN, Sezione Roma ' ' Tor Vergata' ' , Rome (Italy); Universita di Roma ' ' Tor Vergata' ' , Dipt. di Ingegneria Civile e Ingegneria Informatica, Rome (Italy); Ye, Z.P. [Chinese Academy of Sciences, Institute of High Energy Physics, Beijing (China); University of Jing Gangshan, Jiangxi (China)

    2014-03-15

    The results obtained in the search for possible diurnal effect in the single-hit low energy data collected by DAMA/LIBRA-phase1 (total exposure 1.04 ton x year) deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN are presented. At the present level of sensitivity the presence of any significant diurnal variation and of diurnal time structures in the data can be excluded for both the cases of solar and sidereal time. In particular, the diurnal modulation amplitude expected, because of the Earth diurnal motion, on the basis of the DAMA dark matter annual modulation results is below the present sensitivity. (orig.)

  8. Model independent result on possible diurnal effect in DAMA/LIBRA-phase1

    International Nuclear Information System (INIS)

    Bernabei, R.; D'Angelo, S.; Di Marco, A.; Belli, P.; Cappella, F.; D'Angelo, A.; Prosperi, D.; Caracciolo, V.; Castellano, S.; Cerulli, R.; Dai, C.J.; He, H.L.; Kuang, H.H.; Ma, X.H.; Sheng, X.D.; Wang, R.G.; Incicchitti, A.; Montecchia, F.; Ye, Z.P.

    2014-01-01

    The results obtained in the search for possible diurnal effect in the single-hit low energy data collected by DAMA/LIBRA-phase1 (total exposure 1.04 ton x year) deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN are presented. At the present level of sensitivity the presence of any significant diurnal variation and of diurnal time structures in the data can be excluded for both the cases of solar and sidereal time. In particular, the diurnal modulation amplitude expected, because of the Earth diurnal motion, on the basis of the DAMA dark matter annual modulation results is below the present sensitivity. (orig.)

  9. Short term variation of Cyg X-1 in the hard x-ray region

    Energy Technology Data Exchange (ETDEWEB)

    Doi, Kosei [Tokyo Univ. (Japan). Inst. of Space and Aeronautical Science

    1978-08-01

    Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole.

  10. Short term variation of Cyg X-1 in the hard x-ray region

    International Nuclear Information System (INIS)

    Doi, Kosei

    1978-01-01

    Cyg X-1 is a peculiar celestial body considered to be a close binary system of a black hole and a blue super-giant star. It is presently known that the time fluctuation of Cyg X-1 is considerably complex, ranging from seconds to days or months. Of these variation, attention has been paid to the short time variation in relation to the black hole theory. Observations of fluctuations in the order of second have been limited to soft X-ray (20 keV or more) so far, because great technical difficulties are involved due to the low intensity of hard X-ray. The present investigation is based on the fluctuations in the order of second in hard X-ray, and was conducted by employing an unprecedented large area X-ray telescope. The text describes on the brief history of the short time fluctuation, explains the experimental plan, X-ray detecting system, flight of a balloon and the analyses and discussions of fluctuation factor by variation function method, and gives the analysis data and conclusion. The observations resulted in the fact that the fluctuations in the order of second were small at 20 to 30 keV, but become large when energy is higher or lower than this value. The most natural explanation available for this result may be that it is essentially spectrum fluctuation, being inverse correlation in higher and lower energies. Physical meaning of such spectrum fluctuation is considered in connection with precipitating disk model around a black hole. (Wakatsuki, Y.)

  11. The Determination of γ and X Rays Variation in Radioactivity Measurement of Eu-152 Using Merlin Gerin Ionization Chamber

    International Nuclear Information System (INIS)

    Gatot-Wurdiyanto; Tuti-Budiantari, C; Ermi-Juita; Hermawan-Candra; Eni-Suswantini; Holnisar; Wahyudi

    2001-01-01

    Activity measurement of Eu-152 was carried out by using dose calibrator Merlin Gerin. Four samples having their solution factors was prepared for the measurement. The activities of each sample were determined with four variations of γ-rays and X-rays, namely all of γ-rays, all of γ rays and all of X-rays; 15 greater γ-rays intensities; 15 greater γ-rays intensities and all of X-rays. The reference of the measurement is the measurement result using γ-spectrometry methods. The result of the measurement is fairly good, meanwhile the best measurement of Eu-152 is based on all of γ-rays and X-rays which its difference of under 0.5 %. (author)

  12. Diurnal fluctuations in calcium level in the blood serum and homogenates of the kidney and small intestine of mice. Pt. 1. Influence of X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Fialkowski, M. (Uniwersytet Jagiellonski, Krakow (Poland))

    1980-01-01

    Male and female mice were whole-body X-rayed with a dose 2100 R. Rhythmic changes in the calcium level in the blood serum and renal and intestinal homogenates were studied. The study material was secured in the course of one day at 6-hr intervals: at 12:00, 18:00, 24:00, 6:00 and 12:00 hr. The control animals showed rhythmic changes of calcium level in the blood serum and in the kidney and intestinal homogenates. Rhythmicity of the calcium level in the study material was distinctly changed after exposure of males and females to X-rays. Altered rhythmic phases were noted in comparison with the rhythm in control animals. In males, irradiation caused significant lowering of the calcium level in the intestinal and renal homogenates and blood serum. Hypocalcemia and an altered rhythm of changes in calcium level was probably due to impaired calcium transport in the small intestine and renal tubules in the irradiated animals.

  13. Diurnal fluctuations in calcium level in the blood serum and homogenates of the kidney and small intestine of mice. Pt. 1. Influence of X-rays

    International Nuclear Information System (INIS)

    Fialkowski, M.

    1980-01-01

    Male and female mice were whole-body X-rayed with a dose 2100 R. Rhythmic changes in the calcium level in the blood serum and renal and intestinal homogenates were studied. The study material was secured in the course of one day at 6-hr intervals: at 12:00, 18:00, 24:00, 6:00 and 12:00 hr. The control animals showed rhythmic changes of calcium level in the blood serum and in the kidney and intestinal homogenates. Rhythmicity of the calcium level in the study material was distinctly changed after exposure of males and females to X-rays. Altered rhythmic phases were noted in comparison with the rhythm in control animals. In males, irradiation caused significant lowering of the calcium level in the intestinal and renal homogenates and blood serum. Hypocalcemia and an altered rhythm of changes in calcium level was probably due to impaired calcium transport in the small intestine and renal tubules in the irradiated animals. (author)

  14. A Multi-Variate Fit to the Chemical Composition of the Cosmic-Ray Spectrum

    Science.gov (United States)

    Eisch, Jonathan

    Since the discovery of cosmic rays over a century ago, evidence of their origins has remained elusive. Deflected by galactic magnetic fields, the only direct evidence of their origin and propagation remain encoded in their energy distribution and chemical composition. Current models of galactic cosmic rays predict variations of the energy distribution of individual elements in an energy region around 3x1015 eV known as the knee. This work presents a method to measure the energy distribution of individual elemental groups in the knee region and its application to a year of data from the IceCube detector. The method uses cosmic rays detected by both IceTop, the surface-array component, and the deep-ice component of IceCube during the 2009-2010 operation of the IC-59 detector. IceTop is used to measure the energy and the relative likelihood of the mass composition using the signal from the cosmic-ray induced extensive air shower reaching the surface. IceCube, 1.5 km below the surface, measures the energy of the high-energy bundle of muons created in the very first interactions after the cosmic ray enters the atmosphere. These event distributions are fit by a constrained model derived from detailed simulations of cosmic rays representing five chemical elements. The results of this analysis are evaluated in terms of the theoretical uncertainties in cosmic-ray interactions and seasonal variations in the atmosphere. The improvements in high-energy cosmic ray hadronic-interaction models informed by this analysis, combined with increased data from subsequent operation of the IceCube detector, could provide crucial limits on the origin of cosmic rays and their propagation through the galaxy. In the course of developing this method, a number of analysis and statistical techniques were developed to deal with the difficulties inherent in this type of measurement. These include a composition-sensitive air shower reconstruction technique, a method to model simulated event

  15. Wood density variation and tree ring distinctness in Gmelina arborea trees by x-ray densitometry

    Directory of Open Access Journals (Sweden)

    Roger Moya

    2009-03-01

    Full Text Available Due to its relationship with other properties, wood density is the main wood quality parameter. Modern, accuratemethods such as X-ray densitometry - are applied to determine the spatial distribution of density in wood sections and to evaluatewood quality. The objectives of this study were to determinate the influence of growing conditions on wood density variation andtree ring demarcation of gmelina trees from fast growing plantations in Costa Rica. The wood density was determined by X-raydensitometry method. Wood samples were cut from gmelina trees and were exposed to low X-rays. The radiographic films weredeveloped and scanned using a 256 gray scale with 1000 dpi resolution and the wood density was determined by CRAD and CERDsoftware. The results showed tree-ring boundaries were distinctly delimited in trees growing in site with rainfall lower than 2510 mm/year. It was demonstrated that tree age, climatic conditions and management of plantation affects wood density and its variability. Thespecific effect of variables on wood density was quantified by for multiple regression method. It was determined that tree yearexplained 25.8% of the total variation of density and 19.9% were caused by climatic condition where the tree growing. Wood densitywas less affected by the intensity of forest management with 5.9% of total variation.

  16. Biophysical information in asymmetric and symmetric diurnal bidirectional canopy reflectance

    Science.gov (United States)

    Vanderbilt, Vern C.; Caldwell, William F.; Pettigrew, Rita E.; Ustin, Susan L.; Martens, Scott N.; Rousseau, Robert A.; Berger, Kevin M.; Ganapol, B. D.; Kasischke, Eric S.; Clark, Jenny A.

    1991-01-01

    The authors present a theory for partitioning the information content in diurnal bidirectional reflectance measurements in order to detect differences potentially related to biophysical variables. The theory, which divides the canopy reflectance into asymmetric and symmetric functions of solar azimuth angle, attributes asymmetric variation to diurnal changes in the canopy biphysical properties. The symmetric function is attributed to the effects of sunlight interacting with a hypothetical average canopy which would display the average diurnal properties of the actual canopy. The authors analyzed radiometer data collected diurnally in the Thematic Mapper wavelength bands from two walnut canopies that received differing irrigation treatments. The reflectance of the canopies varied with sun and view angles and across seven bands in the visible, near-infrared, and middle infrared wavelength regions. Although one of the canopies was permanently water stressed and the other was stressed in mid-afternoon each day, no water stress signature was unambiguously evident in the reflectance data.

  17. Wood density variation in Gmelina arborea trees using X-ray densitometry

    International Nuclear Information System (INIS)

    Roque, Roger Moya; Tomazello, Mario

    2005-01-01

    The wood density constitutes the main wood quality parameter by its relationship with anatomical, physical and chemical properties and wood utilization. The modern and accurate methods - like X-ray densitometry - are applied to determine the density spatial distribution in wood sections and pith-bark direction. On the other hand, emphasis to wood utilization from fast growing plantations, like Gmelina arborea in Costa Rica, has been done. The objectives of this study were to determinate the influence of 2 climatic conditions of Costa Rica on radial wood density variation of gmelina trees form fast growing plantations using the X-ray densitometry method. Wood samples were cut at DBH of gmelina trees and transversal thin laths were selected at north-south direction and conditioned at 12% moisture content equilibrium and X-rayed. The radiographic films were revealed and scanned a 256 gray scale with 1000 dpi resolution and the intra tree-ring density were determined by CRAD and CERD software. The results demonstrated that the climatic and forest management affects the wood density variability and the distinctness of tree-ring boundaries of gmelina trees, as well as, the applicability of X-ray densitometry in wood quality analysis. (author)

  18. Gamma ray irradiation induced optical band gap variations in silica sol-gel doped sucrose

    International Nuclear Information System (INIS)

    Marzouki, F.; Farah, K.; Hamzaoui, A.H; Ben Ouada, H

    2015-01-01

    The silica xerogels doped sucrose was prepared via sol-gel process and exposed at room temperature to different doses of high energy ("6"0Co) gamma irradiation. Changes in the UV-visible and FTIR spectra of pristine and irradiated xerogels with varying of gamma doses rays show variation in the gap energy. It was found that energy gap of the investigated silica xerogels decreases with increasing the gamma irradiation doses. Thereby the irradiated samples reveal behaviour changes, from an insulator (Eg ∼5,8 eV) towards a semiconductor with (Eg ∼ 3.5 eV).

  19. The 4.8 hour variation of Cygnus X-3 at high X-ray energies

    International Nuclear Information System (INIS)

    Pietsch, W.; Kendziorra, E.; Staubert, R.; Trumper, J.

    1976-01-01

    During a balloon observation of Cygnus X-3 on 1975 February 20, an intensity variation has been found which is in phase with the low-energy X-ray 4.8 hour sinusoidal light curve. The measured relative amplitude in the range 32--64 keV is 0.37 (+0.31, -0.29). Compared with the results at lower energies there is no indication for an energy dependence of the relative amplitude up to 64 keV. The encountered low-intensity source spectrum is compared with previous measurements

  20. Diurnal changes in flavonoids

    International Nuclear Information System (INIS)

    Veit, M.; Bilger, W.; Mühlbauer, T.; Brummet, W.; Winter, K.

    1996-01-01

    Field studies of a tropical tree, Anacardium excelsum, and a northern hemisphere high altitude fern, Cryptogramma crispa, revealed marked diurnal changes in soluble flavonoid content of leaves and fronds, respectively. The flavonoid content increased during the morning and decreased during the afternoon. In plants of C. crispa covered with UV-B absorbing filters, the flavonoid content remained at a constant level throughout the day/night cycle. Upon removal of UV-B absorbing filters (at night), the flavonoid content increased the next morning in a fashion similar to that observed in control plants maintained without filters. Decreases in photosystem II photochemical efficiency upon exposure of C. crispa to natural daylight were similar in plants previously covered with UV-B absorbing filters and in control plants, probably owing to the observed ability of plants to rapidly accumulate UV-B protective flavonoids. (author)

  1. Variation of several agronomic and biochemical traits in γ-ray induced mutant soybeans

    International Nuclear Information System (INIS)

    Shim, Kyo Moon; Kim, Sun Hyung; Kim, Nam Soo; Son, Hi Sup; Rhee, Hae Ik

    1996-01-01

    Two soybean cultivars(Paldalkong and Bangsakong) were irradiated with gamma-ray to reduce seed size, which is an important trait for soybean sprout and the derived mutant soybeans were analyzed in several agronomic and biochemical traits. There were high levels of variations in quantitative traits among the mutants. Several mutant lines showed higher yield and smaller seed than their parents. Qualitative traits such as seed coat color or pubescent color were also changed in a few lines. Biochemical variations were also observed among the mutants. In seed storage protein analysis, many mutant lines showed reduced intensities in β-subunits in 7S globulin than their parents and an additional band in the acidic subunit at 31KDa. Two mutant lines derived from Paldalkong showed an additional band and a shifted band of protease inhibitor by electrophoretic analysis. Variations in isozymes and RAPD were also observed among the mutants. Six isozymes(Adh, Est, Gdh, Idh, Mdh and Pgm) among eleven isozymes showed some variations and six out of ten primers showed polymorphic amplified DNA fragments among the mutants. (author)

  2. Spatial variation of natural terrestrial γ-ray dose rates in Brunei

    International Nuclear Information System (INIS)

    Hu, S.J.; Lai, K.K.

    1998-01-01

    A carborne survey of natural terrestrial y-ray dose rates along the main roads of the western part of Brunei Darussalam was carried out using two portable type 1.5'φx4' NaI(T1) and 1'φx2' NaI(T1) scintillation counters. A series of semicontinuous count rates measurements were performed inside a moving vehicle. This yielded equal-distance data which were analysed statistically to obtain the spatial variation of the natural terrestrial γ-ray dose rates. The equal-distance data of dose rates were obtained by correcting for shielding effect of the car. The thickness of the pavement and the contribution from the pavement material were estimated from a correlation curve between the dose rates measured on pavements and on the nearby soils. A spectral analysis of the equal-distance data enabled us to clarify the structure of the spatial variation in dose rates. The data could be reasonably smoothened by removing the random noise components in a higher wave number region

  3. Geomagnetic, ionospheric and cosmic ray variations around the passages of different magnetic clouds

    International Nuclear Information System (INIS)

    Maercz, F.

    1992-01-01

    Thirty-four interplanetary magnetic clouds have been divided into two groups on the basis of Wilson's (J.geophys. Res. 95, 215, 1990) classification: NS clouds (whose B z near cloud onset at Earth is directed northward, and soon after B z is turning southward) and SN clouds (those with an opposite behaviour with respect to B z ). Using the days of cloud onsets as key days, geomagnetic, ionospheric and cosmic ray data have been analysed by the superposed epoch analysis method for passages of both NS and SN clouds. On the basis of the daily ΣK p values, geomagnetic activity is found to suddenly increase in the vicinity of both types of cloud passages. Afterwards, the variation shown by the geomagnetic indices is found to differ for NS clouds in comparison with SN clouds. Namely, on average the recovery to a normal activity level is much slower for NS clouds. Similarly, the enhancements in the ionospheric absorption of radio waves (the so-called ''after-effects'') are found to show different signatures according to cloud type, an interpretation also valid for variations in cosmic ray intensity. The latter results are based on analyses of neutron monitor counts observed at two stations (Apatity: 67 N; and Moscow: 55 o N). (author)

  4. LISA Pathfinder test-mass charging during galactic cosmic-ray flux short-term variations

    Science.gov (United States)

    Grimani, C.; Fabi, M.; Lobo, A.; Mateos, I.; Telloni, D.

    2015-02-01

    Metal free-floating test masses aboard the future interferometers devoted to gravitational wave detection in space are charged by galactic and solar cosmic rays with energies \\gt 100 MeV/n. This process represents one of the main sources of noise in the lowest frequency band (\\lt 10-3 Hz) of these experiments. We study here the charging of the LISA Pathfinder (LISA-PF) gold-platinum test masses due to galactic cosmic-ray (GCR) protons and helium nuclei with the Fluka Monte Carlo toolkit. Projections of the energy spectra of GCRs during the LISA-PF operations in 2015 are considered. This work was carried out on the basis of the solar activity level and solar polarity epoch expected for LISA-PF. The effects of GCR short-term variations are evaluated here for the first time. Classical Forbush decreases, GCR variations induced by the Sun rotation, and fluctuations in the LISA-PF frequency bandwidth are discussed.

  5. Seasonal variation in the environmental background level of cosmic ray produced 22Na

    International Nuclear Information System (INIS)

    Tokuyama, Hideki; Igarashi, Shuichi

    1998-01-01

    22 Na (half life 2.6 year) is produced by cosmic rays, nuclear test and reactor. 7 Be (half life 53.3 day) is produced in atmosphere by reaction. 7 Be/ 22 Na activity ratio is good factor to observe the mixing process between stratosphere and troposphere atmosphere. The seasonal variation of 7 Be and 22 Na deposition, the ratio and the background level of 22 Na deposition were observed in Fukui city and reported in this paper. Very large reasonable change of 22 Na deposition was observed, especially the largest peak in winter. Because the concentration of cosmic-ray-produced nuclear in precipitation and the amount of precipitation were large in winter. 22 Na produced by the previous nuclear test was attenuated. The present 22 Na is only produced by cosmic rays, indicating the background level. 22 Na deposition at Fukui was 0.42Bq m -2 y -1 , one ten-thousandth of 7 Be deposition. 7 Be/ 22 Na activity ratio was changed in season and the largest peak was shown in autumn. In this reason, atmosphere showed relatively short residence time in the lower part of stratosphere, Mixture and exchange of atmosphere between stratosphere and troposphere were the most active in autumn. (S.Y.)

  6. Observation of the thunderstorm-related ground cosmic ray flux variations by ARGO-YBJ

    Science.gov (United States)

    Bartoli, B.; Bernardini, P.; Bi, X. J.; Cao, Z.; Catalanotti, S.; Chen, S. Z.; Chen, T. L.; Cui, S. W.; Dai, B. Z.; D'Amone, A.; Danzengluobu; De Mitri, I.; D'Ettorre Piazzoli, B.; Di Girolamo, T.; Di Sciascio, G.; Feng, C. F.; Feng, Zhaoyang; Feng, Zhenyong; Gao, W.; Gou, Q. B.; Guo, Y. Q.; He, H. H.; Hu, Haibing; Hu, Hongbo; Iacovacci, M.; Iuppa, R.; Jia, H. Y.; Labaciren; Li, H. J.; Liu, C.; Liu, J.; Liu, M. Y.; Lu, H.; Ma, L. L.; Ma, X. H.; Mancarella, G.; Mari, S. M.; Marsella, G.; Mastroianni, S.; Montini, P.; Ning, C. C.; Perrone, L.; Pistilli, P.; Salvini, P.; Santonico, R.; Shen, P. R.; Sheng, X. D.; Shi, F.; Surdo, A.; Tan, Y. H.; Vallania, P.; Vernetto, S.; Vigorito, C.; Wang, H.; Wu, C. Y.; Wu, H. R.; Xue, L.; Yang, Q. Y.; Yang, X. C.; Yao, Z. G.; Yuan, A. F.; Zha, M.; Zhang, H. M.; Zhang, L.; Zhang, X. Y.; Zhang, Y.; Zhao, J.; Zhaxiciren; Zhaxisangzhu; Zhou, X. X.; Zhu, F. R.; Zhu, Q. Q.; D'Alessandro, F.; ARGO-YBJ Collaboration

    2018-02-01

    A correlation between the secondary cosmic ray flux and the near-earth electric field intensity, measured during thunderstorms, has been found by analyzing the data of the ARGO-YBJ experiment, a full coverage air shower array located at the Yangbajing Cosmic Ray Laboratory (4300 m a. s. l., Tibet, China). The counting rates of showers with different particle multiplicities (m =1 , 2, 3, and ≥4 ) have been found to be strongly dependent upon the intensity and polarity of the electric field measured during the course of 15 thunderstorms. In negative electric fields (i.e., accelerating negative charges downwards), the counting rates increase with increasing electric field strength. In positive fields, the rates decrease with field intensity until a certain value of the field EFmin (whose value depends on the event multiplicity), above which the rates begin increasing. By using Monte Carlo simulations, we found that this peculiar behavior can be well described by the presence of an electric field in a layer of thickness of a few hundred meters in the atmosphere above the detector, which accelerates/decelerates the secondary shower particles of opposite charge, modifying the number of particles with energy exceeding the detector threshold. These results, for the first time to our knowledge, give a consistent explanation for the origin of the variation of the electron/positron flux observed for decades by high altitude cosmic ray detectors during thunderstorms.

  7. Automatic evaluation of vessel diameter variation from 2D X-ray angiography.

    Science.gov (United States)

    M'hiri, Faten; Duong, Luc; Desrosiers, Christian; Dahdah, Nagib; Miró, Joaquim; Cheriet, Mohamed

    2017-11-01

    Early detection of blood vessel pathologies can be made through the evaluation of functional and structural abnormalities in the arteries, including the arterial distensibility measure. We propose a feasibility study on computing arterial distensibility automatically from monoplane 2D X-ray sequences for both small arteries (such as coronary arteries) and larger arteries (such as the aorta). To compute the distensibility measure, three steps were developed: First, the segment of an artery is extracted using our graph-based segmentation method. Then, the same segment is tracked in the moving sequence using our spatio-temporal segmentation method: the Temporal Vessel Walker. Finally, the diameter of the artery is measured automatically at each frame of the sequence based on the segmentation results. The method was evaluated using one simulated sequence and 4 patients' angiograms depicting the coronary arteries and three depicting the ascending aorta. Results of the simulated sequence achieved a Dice index of 98%, with a mean squared error in diameter measurement of [Formula: see text] mm. Results obtained from patients' X-ray sequences are consistent with manual assessment of the diameter by experts. The proposed method measures changes in diameter of a specific segment of a blood vessel during the cardiac sequence, automatically based on monoplane 2D X-ray sequence. Such information might become a key to help physicians in the detection of variations of arterial stiffness associated with early stages of various vasculopathies.

  8. Cosmic ray variations of solar origin in relation to human physiological state during the December 2006 solar extreme events

    Science.gov (United States)

    Papailiou, M.; Mavromichalaki, H.; Vassilaki, A.; Kelesidis, K. M.; Mertzanos, G. A.; Petropoulos, B.

    2009-02-01

    There is an increasing amount of evidence linking biological effects to solar and geomagnetic disturbances. A series of studies is published referring to the changes in human physiological responses at different levels of geomagnetic activity. In this study, the possible relation between the daily variations of cosmic ray intensity, measured by the Neutron Monitor at the Cosmic Ray Station of the University of Athens (http://cosray.phys.uoa.gr) and the average daily and hourly heart rate variations of persons, with no symptoms or hospital admission, monitored by Holter electrocardiogram, is considered. This work refers to a group of persons admitted to the cardiological clinic of the KAT Hospital in Athens during the time period from 4th to 24th December 2006 that is characterized by extreme solar and geomagnetic activity. A series of Forbush decreases started on 6th December and lasted until the end of the month and a great solar proton event causing a Ground Level Enhancement (GLE) of the cosmic ray intensity on 13th December occurred. A sudden decrease of the cosmic ray intensity on 15th December, when a geomagnetic storm was registered, was also recorded in Athens Neutron Monitor station (cut-off rigidity 8.53 GV) with amplitude of 4%. It is noticed that during geomagnetically quiet days the heart rate and the cosmic ray intensity variations are positively correlated. When intense cosmic ray variations, like Forbush decreases and relativistic proton events produced by strong solar phenomena occur, cosmic ray intensity and heart rate get minimum values and their variations, also, coincide. During these events the correlation coefficient of these two parameters changes and follows the behavior of the cosmic ray intensity variations. This is only a small part of an extended investigation, which has begun using data from the year 2002 and is still in progress.

  9. Dosimetric effects of rotational output variation and x-ray target degradation on helical tomotherapy plans

    International Nuclear Information System (INIS)

    Staton, Robert J.; Langen, Katja M.; Kupelian, Patrick A.; Meeks, Sanford L.

    2009-01-01

    In this study, two potential sources of IMRT delivery error have been identified for helical tomotherapy delivery using the HiART system (TomoTherapy, Inc., Madison, WI): Rotational output variation and target degradation. The HiArt system is known to have output variation, typically about ±2%, due to the absence of a dose servo system. On the HiArt system, x-ray target replacement is required approximately every 10-12 months due to target degradation. Near the end of target life, the target thins and causes a decrease in the beam energy and a softening of the beam profile at the lateral edges of the beam. The purpose of this study is to evaluate the dosimetric effects of rotational output variation and target degradation by modeling their effects and incorporating them into recalculated treatment plans for three clinical scenarios: Head and neck, partial breast, and prostate. Models were created to emulate both potential sources of error. For output variation, a model was created using a sine function to match the amplitude (±2%), frequency, and phase of the measured rotational output variation data. A second model with a hypothetical variation of ±7% was also created to represent the largest variation that could exist without violating the allowable dose window in the delivery system. A measured beam profile near the end of target life was used to create a modified beam profile model for the target degradation. These models were then incorporated into the treatment plan by modifying the leaf opening times in the delivery sinogram. A new beam model was also created to mimic the change in beam energy seen near the end of target life. The plans were then calculated using a research version of the PLANNED ADAPTIVE treatment planning software from TomoTherapy, Inc. Three plans were evaluated in this study: Head and neck, partial breast, and prostate. The D 50 of organs at risk, the D 95 for planning target volumes (PTVs), and the local dose difference were used to

  10. Diurnal rhythm in serum levels of inhibin B in normal men

    DEFF Research Database (Denmark)

    Carlsen, E; Olsson, C; Petersen, J H

    1999-01-01

    in the early morning hours and lower values in the late afternoon and evening. We did not find evidence for a role of FSH in this diurnal variation of inhibin B. However, covariation with serum levels of testosterone and estradiol suggested that these hormones might play a role in the diurnal rhythm of inhibin...

  11. Variations in 6MV x-ray radiotherapy build-up dose with treatment distance

    International Nuclear Information System (INIS)

    Butson, M.J.; Illawarra Cancer Care Centre, Wollongong, NSW; Cheung, T.; Yu, P.K.N.

    2003-01-01

    Dose in the build up region for high energy x-rays produced by a medical linear accelerator is affected by the x-ray source to patient surface distance (SSD). The use of isocentric treatments whereby the tumour is positions 100cm from the source means that depending of the depth of the tumour and the size of the patient, the SSD can vary from distances of 80cm to 100cm. To achieve larger field sizes, the SSD can also be extended out to 120cm at times. Results have shown that open fields are not significantly affected by SSD changes with deviations in percentage dose being less than 4% of maximum dose for SSD's from 80cm to 120cm SSD. With the introduction of beam modifying devices such as Perspex blocking trays, the effects are significant with a deviation of up to 22% measured at 6MV energy with a 6mm Perspex tray for SSD's from 80cm to 120cm. These variations are largest at the skin surface and reduce with depth. The use of a multi leaf collimator for blocking removes extra skin dose caused by the Perspex block trays with decreasing SSD. Copyright (2003) Australasian College of Physical Scientists and Engineers in Medicine

  12. Rapid X-Ray Variations of the Geminga Pulsar Wind Nebula

    Energy Technology Data Exchange (ETDEWEB)

    Hui, C. Y.; Lee, Jongsu [Department of Astronomy and Space Science, Chungnam National University, Daejeon 34134 (Korea, Republic of); Kong, A. K. H. [Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu, Taiwan (China); Tam, P. H. T. [School of Physics and Astronomy, Sun Yat-Sen University, Guangzhou 510275 (China); Takata, J. [Institute of Particle Physics and Astronomy, Huazhong University of Science and Technology, Wuhan (China); Cheng, K. S. [Department of Physics, University of Hong Kong, Pokfulam Road (Hong Kong); Ryu, Dongsu, E-mail: cyhui@cnu.ac.kr [Department of Physics, UNIST, Ulsan 44919 (Korea, Republic of)

    2017-09-10

    A recent study by Posselt et al. reported the deepest X-ray investigation of the Geminga pulsar wind nebula (PWN) by using Chandra X-ray Observatory . In comparison with previous studies of this system, a number of new findings have been reported, and we found that these suggest the possible variabilities in various components of this PWN. This motivates us to carry out a dedicated search for the morphological and spectral variations of this complex nebula. We have discovered variabilities on timescales from a few days to a few months from different components of the nebula. The fastest change occurred in the circumstellar environment at a rate of 80% of the speed of light. One of the most spectacular results is the wiggling of a half light-year long tail as an extension of the jet, which is significantly bent by the ram pressure. The jet wiggling occurred at a rate of about 20% of the speed of light. This twisted structure could possibly be a result of a propagating torsional Alfv́en wave. We have also found evidence of spectral hardening along this tail for a period of about nine months.

  13. Quantitative measurements of localized density variations in cylindrical tablets using X-ray microtomography.

    Science.gov (United States)

    Busignies, Virginie; Leclerc, Bernard; Porion, Patrice; Evesque, Pierre; Couarraze, Guy; Tchoreloff, Pierre

    2006-08-01

    Direct compaction is a complex process that results in a density distribution inside the tablets which is often heterogeneous. Therefore, the density variations may affect the compact properties. A quantitative analysis of this phenomenon is still lacking. Recently, X-ray microtomography has been successfully used in pharmaceutical development to study qualitatively the impact of tablet shape and break-line in the density of pharmaceutical tablets. In this study, we evaluate the density profile in microcrystalline cellulose (Vivapur 12) compacts obtained at different mean porosity (ranging from 7.7% to 33.5%) using X-ray tomography technique. First, the validity of the Beer-Lambert law is studied. Then, density calibration is performed and density maps of cylindrical tablets are obtained and visualized using a process with colour-scale calibration plot which is explained. As expected, important heterogeneity in density is observed and quantified. The higher densities in peripheral region were particularly investigated and appraised in regard to the lower densities observed in the middle of the tablet. The results also underlined that in the case of pharmaceutical tablets, it is important to differentiate the mechanical properties representative of the total volume tablet and the mechanical properties that only characterize the tablet surface like the Brinell hardness measurements.

  14. diurnal climatic pressure on haematology and blood biochemistry of ...

    African Journals Online (AJOL)

    Twelve 2.5-year-old West African Dward (WAD) sheep consisting of eight (8) ewes and four (4) rams with mean body weight 19.4kg were used to study the effects of diurnal (morning and afternoon) climatic variations on the haematological and biochemical responses in WAD sheep. The animals were randomly assigned to ...

  15. Spatial variation of natural terrestrial gamma-ray dose rates in Brunei

    International Nuclear Information System (INIS)

    Hu, S.J.; Lai, K.K.; Manato, S.; Kodaira, K.

    1998-01-01

    A carbon survey of natural terrestrial gamma-rat dose rates along the main roads of the western part of Brunei Darussalam was carried out using two portable type 1.5 φ x 4 NaI(TI) and 1 φ x 2 NaI(TI) scintillation counters. A series of semicontinuous count rates measurements were performed inside a moving vehicle. This yielded equal-distance data which were analysed statistically to obtain the spatial variation of the natural terrestrial gamma-ray dose rates. The equal-distance data of dose rates were obtained by correcting for shielding effect of the car. The thickness of the pavement and the contribution from the pavement material were estimated from a correlation curve between the dose rates measured on pavements and on the nearby soils. A spectral analysis of the equal-distance data enabled us to clarify the structure of the spatial variation in dose rates. The data could be reasonably smoothened by removing the random noise components in a higher wave number region. (author). 6 refs., 7 figs., 1 tab

  16. 2-D Modelling of Long Period Variations of Galactic Cosmic Ray Intensity

    International Nuclear Information System (INIS)

    Siluszyk, M; Iskra, K; Alania, M

    2015-01-01

    A new two-dimensional (2-D) time dependent model describing long-period variations of the Galactic Cosmic Ray (GCR) intensity has been developed. New approximations for the changes of the magnitude B of the Interplanetary Magnetic Field (IMF), the tilt angle δ of the Heliospheric Neutral Sheet (HNS) and drift effects of the GCR particles have been included into the model. Moreover, temporal changes of the exponent γ expressing the power law - rigidity dependence of the amplitudes of the 11-year variation of the GCR intensity have been added. We show that changes of the expected GCR particle density precedes changes of the GCR intensity measured by the Moscow Neutron (MN) monitor by about 18 months. So ∼18 months can be taken as an effective delay time between the expected intensity caused by the combined influence of the changes of the parameters implemented in the time-dependent 2-D model and the GCR intensity measured by neutron monitors during the 21 cycle of solar activity. (paper)

  17. Correlated Radial Velocity and X-Ray Variations in HD 154791/4U 1700+24

    Science.gov (United States)

    Galloway, Duncan K.; Sokoloski, J. L.; Kenyon, Scott J.

    2002-12-01

    We present evidence for approximately 400 day variations in the radial velocity of HD 154791 (V934 Her), the suggested optical counterpart of 4U 1700+24. The variations are correlated with the previously reported ~400 day variations in the X-ray flux of 4U 1700+24, which supports the association of these two objects, as well as the identification of this system as the second known X-ray binary in which a neutron star accretes from the wind of a red giant. The HD 154791 radial velocity variations can be fitted with an eccentric orbit with period 404+/-3 days, amplitude K=0.75+/-0.12kms-1, and eccentricity e=0.26+/-0.15. There are also indications of variations on longer timescales >~2000 days. We have reexamined all available All-Sky Monitor (ASM) data following an unusually large X-ray outburst in 1997-1998 and confirm that the 1 day averaged 2-10 keV X-ray flux from 4U 1700+24 is modulated with a period of 400+/-20 days. The mean profile of the persistent X-ray variations was approximately sinusoidal, with an amplitude of 0.108+/-0.012 ASM counts s-1 (corresponding to 31% rms). The epoch of X-ray maximum was approximately 40 days after the time of periastron, according to the eccentric orbital fit. If the 400 day oscillations from HD 154791/4U 1700+24 are due to orbital motion, then the system parameters are probably close to those of the only other neutron star symbiotic-like binary, GX 1+4. We discuss the similarities and differences between these two systems.

  18. Diurnal and seasonal occurrence of polar patches

    Directory of Open Access Journals (Sweden)

    A. S. Rodger

    1996-05-01

    Full Text Available Analysis of the diurnal and seasonal variation of polar patches, as identified in two years of HF-radar data from Halley, Antarctica during a period near sunspot maximum, shows that there is a broad maximum in occurrence centred about magnetic noon, not local noon. There are minima in occurrence near midsummer and midwinter, with maxima in occurrence between equinox and winter. There are no significant correlations between the occurrence of polar patches and the corresponding hourly averages of the solar wind and IMF parameters, except that patches usually occur when the interplanetary magnetic field has a southward component. The results can be understood in terms of UT and seasonal differences in the plasma concentration being convected from the dayside ionosphere into the polar cap. In summer and winter the electron concentrations in the polar cap are high and low, respectively, but relatively unstructured. About equinox, a tongue of enhanced ionisation is convected into the polar cap; this tongue is then structured by the effects of the interplanetary magnetic field, but these Halley data cannot be used to separate the various competing mechanisms for patch formation. The observed diurnal and seasonal variation in the occurrence of polar patches are largely consistent with predictions of Sojka et al. (1994 when their results are translated into the southern hemisphere. However, the ionospheric effects of flux transfer events are still considered essential in their formation, a feature not yet included in the Sojka et al. model.

  19. Electrical signature in polar night cloud base variations

    International Nuclear Information System (INIS)

    Harrison, R Giles; Ambaum, Maarten H P

    2013-01-01

    Layer clouds are globally extensive. Their lower edges are charged negatively by the fair weather atmospheric electricity current flowing vertically through them. Using polar winter surface meteorological data from Sodankylä (Finland) and Halley (Antarctica), we find that when meteorological diurnal variations are weak, an appreciable diurnal cycle, on average, persists in the cloud base heights, detected using a laser ceilometer. The diurnal cloud base heights from both sites correlate more closely with the Carnegie curve of global atmospheric electricity than with local meteorological measurements. The cloud base sensitivities are indistinguishable between the northern and southern hemispheres, averaging a (4.0 ± 0.5) m rise for a 1% change in the fair weather electric current density. This suggests that the global fair weather current, which is affected by space weather, cosmic rays and the El Niño Southern Oscillation, is linked with layer cloud properties. (letter)

  20. Suitable gamma ray dose determination in order to induce genetic variation in kaboli chickpea (Cicer Arietinum L)

    International Nuclear Information System (INIS)

    Naserian Khiabani, B.; Ahari Mostafavi, H.; Fathollahi, H.; Vedadi, S.; Mosavi Shalmani, M. A.

    2008-01-01

    In spite of chickpea's use in Iran and its ability of being replaced to adjust the shortage of protein in dietary habits, yield production is very low. One of the main reasons for chickpea's low yield production is its sensitiveness to some diseases, pest and environmental stresses. Genetic variation in chickpea is very low, because of its self pollination. In breeding programs, genetic variation plays an essential role so that the induction of genetic variation in plant population is very important for the plant breeders. The induced mutation through different kinds of mutagens is one of the important ways of genetic variation. In this research, first the sensitiveness of four cultivars (ILC.486, Philip86, Bivinich, Jam) were assessed to different gamma ray doses (100, 200, 300, 400 Gy). The results showed that with an increase in gamma ray dose, the growth rate of chickpea's genotypes decreases. In this respect, the decrease of growth rate has a linear relationship with the gamma ray dose and it is independent from the genotypes. The root length is more sensitive to gamma ray doses than its shoot, and it was observed that at the low doses the root growth decreases, comparing to the shoot growth. On the other hand, in high doses of gamma ray growth abrasion (Ageotropism, Albinism and etc.) were observed. Some traits variation (such as leaf shape, leaf size, leaf color, Albinism, etc.) were seen in M 2 generation, and finally to continue the project, three doses of gamma ray (150,200,250) were selected for the next year

  1. Simultaneous X-ray, UV, and Optical Variations in lambda ERI (B2e)

    Science.gov (United States)

    Smith, M. A.; Murakami, T.; Anandarao, B.

    1996-12-01

    We have carried out a simultaneous observing campaign on the prototypical Be star lambda Eri using ground stations and ROSAT, ASCA, IUE, and Voyager spacecrafts during the week of February-March 1995; a smaller campaign was carried out the following September. In late February lambda Eri showed extraordinary disk-wind activity. ROSAT/HRI monitoring disclosed no large flares such as ROSAT observed in 1991 in lambda Eri. Possible low amplitude fluctuations in the 1995 data occurred at the same time with unusual activity in Hα , HeI lambda 6678, HeII lambda 1640, CIII, and the CIV doublet. The helium line activity suggests that mass ejection occurred at the base of the wind. The strong CIII and CIV lines implies that shock interactions originated in the wind flow. It is not clear that the X-ray fluctuations are directly related to the increases in wind line absorption. Within hours of the mild X-ray flux variations found by ROSAT on February 28, the Voyager UVS observed a ``ringing" that decayed over three 3-hr. cycles. The amplitude of these fluctuations was large (50%) at lambda lambda 950-1100, decreased rapidly with wavelength, and faded to nondetection above lambda 1300. Various considerations indicate that these continuum variations were not due to an instrument pathology in the UVS. Rather, they appear to be due to a time-dependent flux deficit in the lambda lambda 1250 during the minima of these cycles. We outline a scenario in which dense plasma over the star's surface is alternately heated and cooled quasi-periodically to produce the flux changes. Additional examples of this new phenomenon are needed. Amateur astronomers can make a significant contribution to the understanding of flickering in Be star light curves during their outburst phases. We also draw attention to an increase in the emission of the Hα line that occurred at about the same time the FUV ringing started. This increased emission hints that ~ 50,000K plasma near the star's surface can

  2. Recurrent Cosmic-ray Variations as a Probe of the Heliospheric Magnetic Field

    Science.gov (United States)

    Burger, R. A.; Engelbrecht, E. E.

    2006-12-01

    A linear relationship between the observed 26-day recurrent cosmic-ray intensity variations and the global latitudinal gradient was first reported by Zhang (1997, ApJ, 488), who made extensive use of Ulysses data. This relationship is seen for all species considered and at all latitudes covered by the spacecraft. Burger and Hitge (2004, ApJL, 617) used a three-dimensional steady-state numerical modulation model and showed that a Fisk-type (Fisk 1996, JGR, 101) heliospheric magnetic field (HMF) can in principle explain these observations, at least at high latitudes. In this progress report we use a refinement of the Fisk-Parker hybrid HMF model of Burger and Hitge (2004) by Kruger (2006, MSc dissertation, NWU University) (see also Kruger, Burger and Hitge 2005, AGU Fall meeting abstracts SH23B-0341) to study these 26-day recurrent variations in more detail with the same modulation code. In Kruger's model the HMF is Parker-like at the highest latitudes, becomes Fisk- like at intermediate latitudes, and becomes Parker-like again in the region swept out by the wavy current sheet. By using an almost continuous range of latitudinal gradients for both solar magnetic polarity cycles and for both protons and electrons - in contrast to the limited number of values used by Burger and Hitge (2004) - the structure of the graphs of amplitude of the recurrent cosmic-ray intensity variations as function of global latitudinal gradient can be studied in detail. This was performed in a 100 AU model heliosphere for solar minimum conditions with the tilt angle of the heliospheric current sheet at 10 degrees. In all cases drift effects are included. We find that these curves for amplitude vs. latitudinal gradient are similar for protons and for electrons. By switching the sign of the modeled amplitudes when the latitudinal gradient becomes negative, the existence of a single relationship between the two quantities can be studied for the whole range of modeled latitudinal gradients. This

  3. Photographic paper X-ray procedure - a simple technique for the visualisation of osseous norm variations and malformations

    International Nuclear Information System (INIS)

    Markert, K.; Wirth, I.; Reinhold-Richter, L.

    1983-01-01

    On the basis of osseous norm variations and malformations, a simple X-ray procedure by means of photographic paper which can be applied in every institute of pathology is demonstrated. The quality of the photographs permits the assessment of skeletal changes which are of diagnostic importance. (author)

  4. Periodic variations of cosmic ray intensity with period of -37 minute observed on April 25th, 1984

    International Nuclear Information System (INIS)

    Sakai, Takasuke; Kato, Masahito; Takei, Ryoji; Tamai, Eiji

    1985-01-01

    Existence of cosmic ray variation with period ranging from a few hours to seconds during geomagnetically quiet and perturb period at different altitude with different detector, was reported previously. As short period variation is thought to be transient with small amplitude fluctuation, consequently high counting rate of cosmic ray and appropriate method for finding short periodicity, is required. Further, there is similar phenomenon in which short variation, followed by storm sudden commencement (SSC) and/or Forbush decrease (FD) occurs. In 1979, Kato et al. used 3 minutes data at Mt. Norikura and obtained -6 x 10 5 count/min, and tried to find out short periodicity of cosmic ray around SSC, but no clear conclusion was obtained. T. Sakai, et al., used plastic scintillation counter of Akeno observatory, following their preceding work. The counter has an area about 154 m 2 . High counting rate of -2 x 10 6 counts/min. was observed at Akeno which revealed the existence of -37 minute periodical oscillation with an amplitude of 0.1 % in p-p during the time period of 1300 - 1900 UT on April 25th 1984, one day before FD. Observed periodical oscillation of cosmic ray counting rate may be the result of the changes in magnetic field. But, it must be noted that there remains possibility of oscillation of cosmic ray intensity in the interplanetary space during the period, independent of geomagnetic field. (author)

  5. Diurnal variation of hematology parameters in healthy young males: the Bispebjerg study of diurnal variations

    DEFF Research Database (Denmark)

    Sennels, Henriette P; Jørgensen, Henrik L; Hansen, Anne-Louise S

    2011-01-01

    To evaluate the influence of time of day on the circulating concentrations of 21 hematology parameters.......To evaluate the influence of time of day on the circulating concentrations of 21 hematology parameters....

  6. Line strength variations in gamma-ray burst GB870303: Possible evidence of neutron star rotation

    International Nuclear Information System (INIS)

    Graziani, C.; Fenimore, E.E.; Murakami, T.; Yoshida, A.; Lamb, D.Q.; Wang, J.C.L.; Loredo, T.J.

    1991-01-01

    An exhaustive search of the Ginga data on γ-ray burst GB870303 reveals two separate time intervals during which statistically significant line features are evident. One (previously unreported) interval shows a single prominent line feature at ∼20 keV; a second, corresponding to the interval reported by Murakami et al., shows two line features at ∼20 and 40 keV. From model fits to the data, we find that both sets of lines are well-described by cyclotron resonant scattering in a magnetic field B∼1.8x10 12 G, and that the differences in the line strengths between the two intervals are significant. The variations are qualitatively similar to those produced by a change in the viewing angle θ relative the magnetic field. We conjecture that the change in θ is due to rotation of the neutron star, and derive limits 45 sec approx-lt P approx-lt 180 sec on the rotation period P

  7. Deregulated power prices: comparison of diurnal patterns

    International Nuclear Information System (INIS)

    Ying Li; Flynn, P.C.

    2004-01-01

    We examine electrical power price, and in particular its daily and average weekday vs. weekend pattern of change, for 14 deregulated markets. Power price in deregulated markets shows fundamentally different patterns. North American markets show a monotonic diurnal weekday price pattern, while all other markets studied show more than one price peak. Deregulated power markets differ in maximum vs. minimum daily average price and in average weekday to weekend price, in turn creating a different incentive for a consumer to time shift power consuming activities. Markets differ in the extent to which a small fraction of the days shapes the average diurnal pattern and value of price. Deregulated markets show a wide variation in the correlation between load and price. Some deregulated markets, most notably Britain and Spain, show patterns that are predictable and consistent, and hence that can encourage a customer to shape consumption behaviors. Other markets, for example South Australia, have patterns that are inconsistent and irregular, and hence are hard for a customer to interpret; a customer in such a market will have a higher incentive to escape risk through hedging mechanisms. (Author)

  8. Deregulated power prices: comparison of diurnal patterns

    International Nuclear Information System (INIS)

    Li Ying; Flynn, Peter C.

    2004-01-01

    We examine electrical power price, and in particular its daily and average weekday vs. weekend pattern of change, for 14 deregulated markets. Power price in deregulated markets shows fundamentally different patterns. North American markets show a monotonic diurnal weekday price pattern, while all other markets studied show more than one price peak. Deregulated power markets differ in maximum vs. minimum daily average price and in average weekday to weekend price, in turn creating a different incentive for a consumer to time shift power consuming activities. Markets differ in the extent to which a small fraction of the days shapes the average diurnal pattern and value of price. Deregulated markets show a wide variation in the correlation between load and price. Some deregulated markets, most notably Britain and Spain, show patterns that are predictable and consistent, and hence that can encourage a customer to shape consumption behaviors. Other markets, for example South Australia, have patterns that are inconsistent and irregular, and hence are hard for a customer to interpret; a customer in such a market will have a higher incentive to escape risk through hedging mechanisms

  9. Understanding the Effect of Atmospheric Density on the Cosmic Ray Flux Variations at the Earth Surface

    OpenAIRE

    Dayananda, Mathes; Zhang, Xiaohang; Butler, Carola; He, Xiaochun

    2013-01-01

    We report in this letter for the first time the numerical simulations of muon and neutron flux variations at the surface of the earth with varying air densities in the troposphere and stratosphere. The simulated neutron and muon flux variations are in very good agreement with the measured neutron flux variation in Oulu and the muon flux variation in Atlanta. We conclude from this study that the stratosphere air density variation dominates the effects on the muon flux changes while the density...

  10. Interannual and Intraseasonal Variability of the Diurnal Tide

    Science.gov (United States)

    Riggin, D. M.; Ortland, D. A.; Lieberman, R. S.; Oberheide, J.; Murayama, Y.; Hocking, W. K.; Vincent, R. A.; Reid, I. M.; Kumar, G. K.; Batista, P. P.; Clemesha, B. R.

    2013-12-01

    Temporal variations in the amplitude of the diurnal tide (DT) have been observed by radars with a seasonal dependence that is typically semiannual in the tropics. During some years the wind variation departs from the normal seasonal behavior with anomalously large amplitudes compared to most other years. This anomaly often takes the form of a greatly enhanced boreal spring equinoctal maximum. The boreal spring of 2008 is a example of this behavior. Diurnal amplitudes in the meridional winds are shown in the figure below for the first 6 months of 2008. Note that the diurnal tide undergoes a sharp increase in amplitude up to 80 ms-1 during this event. The characteristics of this event are diagnosed in a variety of global data sets. These include our own physics-based assimilation of SABER temperatures, and gridded analyses from the national weather services (NCAR/NCEP and ECMWF). Tidal amplitude variations are sometimes attributed to nonlinear interaction. However, this type of interaction would be expected to produce non-migrating tides, e.g., westward-2 or standing. SABER data show that the amplitude anomaly is mainly in the migrating DT. The global data sets allow us to explore properties of the anomaly, such as its origin, evolution in time, and associated momentum flux. In addition to this case study, we also investigate the general characteristics of DT interannual variability during the years of the SABER mission (2002-present). Diurnal tide momentum deposition plays a significant role in controlling the zonal mean wind in the mesosphere, We demonstrate its importance in driving the mesospheric semiannual oscillation (MSAO). Diurnal tide wind amplitudes in the meridional component observed at two radar sites, Rarotonga, Cook Islands (22.1°S, 159.8°W), and at Guanacaste, Costa Rica (10.3°N, 85.6°W).

  11. Diurnal changes in ocean color in coastal waters

    Science.gov (United States)

    Arnone, Robert; Vandermeulen, Ryan; Ladner, Sherwin; Ondrusek, Michael; Kovach, Charles; Yang, Haoping; Salisbury, Joseph

    2016-05-01

    Coastal processes can change on hourly time scales in response to tides, winds and biological activity, which can influence the color of surface waters. These temporal and spatial ocean color changes require satellite validation for applications using bio-optical products to delineate diurnal processes. The diurnal color change and capability for satellite ocean color response were determined with in situ and satellite observations. Hourly variations in satellite ocean color are dependent on several properties which include: a) sensor characterization b) advection of water masses and c) diurnal response of biological and optical water properties. The in situ diurnal changes in ocean color in a dynamic turbid coastal region in the northern Gulf of Mexico were characterized using above water spectral radiometry from an AErosol RObotic NETwork (AERONET -WavCIS CSI-06) site that provides up to 8-10 observations per day (in 15-30 minute increments). These in situ diurnal changes were used to validate and quantify natural bio-optical fluctuations in satellite ocean color measurements. Satellite capability to detect changes in ocean color was characterized by using overlapping afternoon orbits of the VIIRS-NPP ocean color sensor within 100 minutes. Results show the capability of multiple satellite observations to monitor hourly color changes in dynamic coastal regions that are impacted by tides, re-suspension, and river plume dispersion. Hourly changes in satellite ocean color were validated with in situ observation on multiple occurrences during different times of the afternoon. Also, the spatial variability of VIIRS diurnal changes shows the occurrence and displacement of phytoplankton blooms and decay during the afternoon period. Results suggest that determining the temporal and spatial changes in a color / phytoplankton bloom from the morning to afternoon time period will require additional satellite coverage periods in the coastal zone.

  12. Erratum: Correction to: Long- and Mid-Term Variations of the Soft X-ray Flare Character in Solar Cycles

    Science.gov (United States)

    Chertok, I. M.; Belov, A. V.

    2018-03-01

    Correction to: Solar Phys https://doi.org/10.1007/s11207-017-1169-1 We found an important error in the text of our article. On page 6, the second sentence of Section 3.2 "We studied the variations in soft X-ray flare characteristics in more detail by averaging them within the running windows of ± one Carrington rotation with a step of two rotations." should instead read "We studied the variations in soft X-ray flare characteristics in more detail by averaging them within the running windows of ± 2.5 Carrington rotations with a step of two rotations." We regret the inconvenience. The online version of the original article can be found at https://doi.org/10.1007/s11207-017-1169-1

  13. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosols of the urban area of Madrid; Estudio de las variaciones diarias en las concentraciones de algunos hidrocarburos alifaticos y aromatico; policiclicos, en aerosoles de la zona urbana de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M. M.; Perez-Pastor, R. M.; Bea, F. J.; Campos, A.; Gonzalez, D.

    1991-07-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)

  14. Differences of diurnal variations of some aliphatic and polycyclic aromatic hydrocarbons concentrations in aerosols of the urban area of Madrid; Estudio de las variaciones diarias en las concentraciones de algunos hidrocarburos alifaticos y aromatico; policiclicos, en aerosoles de la zona urbana de Madrid

    Energy Technology Data Exchange (ETDEWEB)

    Perez, M M; Perez-Pastor, R M; Bea, F J; Campos, A; Gonzalez, D

    1991-07-01

    A study on daily concentration changes of polycyclic aromatic and aliphatic hydrocarbons (PAH's and AH's), was carried out in aerosols sampled m the Ciudad Universitaria of Madrid. Samples were taken at morning and night during February and June, for short sampling times, on glass fiber filters in Hi-Vol samplers, and then extracted ultrasonically with cyclohexane. Analysis were performed by HRGC with fused-silica capillary columns. The variable traffic rate, and the strong influence during winter periods of domestic heating are characteristic of this place. The aim of this work was to evaluate diurnal and seasonal variations of selected AH and PAH in the urban area of Madrid, by using descriptive parameters, such as total concentrations of AH and PAH, characteristic profiles and predominance carbon index. (Author)

  15. SST diurnal variability in the North Sea and the Baltic Sea

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, Jacob; Hasager, Charlotte Bay

    2012-01-01

    (σ) between 0.4K and 0.9K. The 5year record with daytime temperature anomalies is used to derive robust statistical description of duration, spatial extent, proximity to coast and water depth of the diurnal warming events. Seasonal and inter-annual variations in the diurnal warming are also...... quantified. Daytime anomalies exceeding 2K are identified during the spring and summer months of every year, peaking at 1500 LT. Events with daily anomalies exceeding 5K are observed. Areas where diurnal variability is often observed coincide with areas of frequently observed low winds and turbid waters...

  16. Preeclampsia prediction in type 1 diabetes and diurnal blood pressure methodology

    DEFF Research Database (Denmark)

    Lauszus, Finn

    2016-01-01

    of the papers with the best, validated methodology on BP measurements, which is by no way guaranteed in numerous recent publications. Inherent characteristics of the measurements to be considered are reproducibility, consistency, precision, and trend over scale of measurement. Studies on these issues suggest....... Preeclampsia is associated with urinary albumin excretion rate, reduced night/day ratio, and elevated diurnal blood pressure from first trimester and onwards. However, due to blunting of the diurnal variation, the night/day rhythm provides no good prediction of preeclampsia. Diurnal measurement is a valuable...

  17. Cosmogenic nuclides in recently fallen meteorites: Evidence for galactic cosmic ray variations during the period 1967--1978

    International Nuclear Information System (INIS)

    Evans, J.C.; Reeves, J.H.; Rancitelli, L.A.; Bogard, D.D.

    1982-01-01

    Cosmogenic radionuclides were measured on 48 fragments of 24 meteorites which fell between 1967 and 1978. Nondestructive gamma counting techniques were used to obtain data on 7 Be, 46 Sc, 48 V, 51 Cr, 54 Mn, 56 Co, 57 Co, 58 Co, and 60 Co on at least some of the samples. Sodium 22 and 26 Al measurements are reported on all 48 samples. In addition, new rare gas data and exposure ages are reported for the meteorites Guibga, Gorlovka, Dhajala, Louisville, Acapulco, Jilin, Kabo, Alta-Ameen, and Canon City. The cosmogenic radioisotope and rare gas data are interpreted in terms of a time dependent modulation of galactic cosmic rays spanning one full 11 year sun spot cycle. Special attention is given to the data on 22 Na, 46 Sc, 54 Mn, and 48 V with either 26 Al or 22 Ne/ 21 Ne used to provide a shielding correction. The shielding normalized data using the 26 Al method appear to correlate well with calculated production rates scaled against the Deep River neutron monitor. The data for the four isotopes are consistent with a production rate variation of a factor of 2.5--3 between solar maximum and solar minimum for sun spot cycle 20. These data demonstrate that the production rates of cosmic ray-produced nuclides in meteorites vary considerably according to modulation by the 11-year solar cycle and support the concept that variations of solar-modulated, cosmic ray flux of similar magnitude have occurred over much longer time periods

  18. Period variations in pulsating X-ray sources. I. Accretion flow parameters and neutron star structure from timing observations

    International Nuclear Information System (INIS)

    Lamb, F.K.; Pines, D.; Shaham, J.

    1978-01-01

    We show that valuable information about both accretion flows and neutron star structure can be obtained from X-ray timing observations of period variations in pulsating sources. Such variations can result from variations in the accretion flow, or from internal torque variations, associated with oscillations of the fluid core or the unpinning of vortices in the inner crust. We develop a statistical description of torque variations in terms of noise processes, indicate how the applicability of such a description may be tested observationally, and show how it may be used to determine from observation both the properties of accretion flows and the internal structure of neutron stars, including the relative inertial moments of the crust and superfluid neutron core, the crust-core coupling time, and the frequencies of any low-frequency internal collective modes. Particular attention is paid to the physical origin of spin-down episodes; it is shown that usyc episodes may result either from external torque reversals or from internal torque variations.With the aid of the statistical description, the response of the star to torque fluctuations is calculated for three stellar models: (i) a completely rigid star; (ii) a two-component star; and (iii) a two-component star with a finite-frequency internal mode, such as the Tkachenko mode of a rotating neutron superfluid. Our calculations show that fluctuating torques could account for the period the period variations and spin-down episodes observed in Her X-1 and Cen X-3, including the large spin-down event observed in the latter source during 1972 September-October. The torque noise strengths inferred from current timing observations using the simple two-component models are shown to be consistent with those to be expected from fluctuations in accretion flows onto magnetic neutron stars

  19. Gamma-ray induced variation in the development of S. Khasianum Clarke

    International Nuclear Information System (INIS)

    Chauhan, Y.S.

    1978-01-01

    Present study deals with the effect of gamma ray exposures (10, 15, 20 and 25 kR) on the plant development in S. Khasianum Clarke. While 25 kR exposure dose was lethal, other exposures affected the development of various plant parts e.g. height, number of branches, and leaf forming capacity. Gamma rays also affected spine number, spine intensity and spine size on the leaves of this plant. Although flowering occurred almost simultaneously both in the control and treated plants, yield, number of berries and weight of the berry were affected. (author)

  20. ON TEMPORAL VARIATIONS OF THE MULTI-TeV COSMIC RAY ANISOTROPY USING THE TIBET III AIR SHOWER ARRAY

    International Nuclear Information System (INIS)

    Amenomori, M.; Bi, X. J.; Ding, L. K.; Fan, C.; Feng Zhaoyang; Gou, Q. B.; He, H. H.; Chen, D.; Cui, S. W.; Danzengluobu; Ding, X. H.; Guo, H. W.; Hu Haibing; Feng, C. F.; He, M.; Feng, Z. Y.; Gao, X. Y.; Geng, Q. X.; Hibino, K.; Hotta, N.

    2010-01-01

    We analyze the large-scale two-dimensional sidereal anisotropy of multi-TeV cosmic rays (CRs) by the Tibet Air Shower Array, with the data taken from 1999 November to 2008 December. To explore temporal variations of the anisotropy, the data set is divided into nine intervals, each with a time span of about one year. The sidereal anisotropy of magnitude, about 0.1%, appears fairly stable from year to year over the entire observation period of nine years. This indicates that the anisotropy of TeV Galactic CRs remains insensitive to solar activities since the observation period covers more than half of the 23rd solar cycle.

  1. Meiosis and ISSR analysis on genetic variation of {sup 60}Co {gamma}-rays irradiated variants of cut chrysanthemum

    Energy Technology Data Exchange (ETDEWEB)

    Lili, Xing; Fadi, Chen; Hengbin, Miao [College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu (China)

    2009-08-15

    Cytology and ISSR technology were used to analyze genetic variations of {sup 60}Co {gamma}-rays induced variants of cut chrysanthemum 'Changzi', for further exploring the mechanism of irradiation and providing theoretical basis for breeding of chrysanthemum. The results showed that, meiotic abnormality ratio of lagging chromosome and chromosome bridge in variants were significantly higher than those in the control at anaphase I and II. The abnormality ratio was also raised with irradiation doses increasing. The highest ratio of two abnormal phenomena at anaphase I was 9.0%, 11.3%, and at anaphase II 15.5%, 8.6%, respectively. Polymorphic bands of 112 were amplified by 21 ISSR primers and the polymorphism rate was 71.3%, which proved that DNA changed in different degrees. These variants were divided into 5 groups by UPGMA based on Jaccard coefficient. It was observed that the clustering result related to their characters of flower shape and color variations. (authors)

  2. Meiosis and ISSR analysis on genetic variation of 60Co γ-rays irradiated variants of cut chrysanthemum

    International Nuclear Information System (INIS)

    Xing Lili; Chen Fadi; Miao Hengbin

    2009-01-01

    Cytology and ISSR technology were used to analyze genetic variations of 60 Co γ-rays induced variants of cut chrysanthemum 'Changzi', for further exploring the mechanism of irradiation and providing theoretical basis for breeding of chrysanthemum. The results showed that, meiotic abnormality ratio of lagging chromosome and chromosome bridge in variants were significantly higher than those in the control at anaphase I and II. The abnormality ratio was also raised with irradiation doses increasing. The highest ratio of two abnormal phenomena at anaphase I was 9.0%, 11.3%, and at anaphase II 15.5%, 8.6%, respectively. Polymorphic bands of 112 were amplified by 21 ISSR primers and the polymorphism rate was 71.3%, which proved that DNA changed in different degrees. These variants were divided into 5 groups by UPGMA based on Jaccard coefficient. It was observed that the clustering result related to their characters of flower shape and color variations. (authors)

  3. Study of the variation of radiation dose in function of the radiological techniques used in X-ray diagnosis exams

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Marco A.R., E-mail: marfernandes@fmb.unesp.br [Faculty of Medicine. UNESP, Botucatu (FMB), SP (Brazil); Reis, Charlene O.; Garcia, Paulo L. [Institute of Biosciences of Botucatu. UNESP, Botucatu, SP (Brazil); Nucleate Radiometry Ltd., Aracatuba, SP (Brazil); Lima, Marcelo A.F.; Dalaqua, Fernando L.D. [UNESP, Botucatu, SP (Brazil). Hospital. Radiology Service

    2011-07-01

    This paper values the importance of the implantation of a quality control program in medical x-ray diagnosis services that it seeks mainly to the reduction of the radiation dose applied in the radiology exams, and attempt to the precepts of the Effective Legislation as for the Basic Guidelines of Radiological Protection (law decree MS no. 453 in June 1{sup st} 1998). The study was accomplished Radiology Section of the Medicine Faculty - FMB (UNESP - Botucatu) and it consisted of the accomplishment of measures of the radiation dose applied in the radiological exams, taking as base the x-rays techniques realized by four technicians in radiology the service, using only one x-rays equipment. Was intended analyze the variation of the radiation dose in function of the different applied technical parameters, and this way, guide the professionals as for the possibility of obtaining of x-ray images of better quality and smaller patient exposition. For radiation dose measure a detector of solid state was utilized. During the accomplishment of the measures it was verified that there no a general consensus among the technicians of the section being observed differences of the order of 80% in the mAs. In terms of radiation dose measured, the largest value of verified was 4.752 mGy (exam of lateral lumbar column) and the smallest value of 0.165 mGy (child's thorax).The results showed that a standardization in the x-ray techniques executed by the professionals of the section will be able to reduce significantly the radiation exposition of the assisted patients. (author)

  4. Study of the variation of radiation dose in function of the radiological techniques used in X-ray diagnosis exams

    International Nuclear Information System (INIS)

    Fernandes, Marco A.R.; Reis, Charlene O.; Garcia, Paulo L.; Lima, Marcelo A.F.; Dalaqua, Fernando L.D.

    2011-01-01

    This paper values the importance of the implantation of a quality control program in medical x-ray diagnosis services that it seeks mainly to the reduction of the radiation dose applied in the radiology exams, and attempt to the precepts of the Effective Legislation as for the Basic Guidelines of Radiological Protection (law decree MS no. 453 in June 1 st 1998). The study was accomplished Radiology Section of the Medicine Faculty - FMB (UNESP - Botucatu) and it consisted of the accomplishment of measures of the radiation dose applied in the radiological exams, taking as base the x-rays techniques realized by four technicians in radiology the service, using only one x-rays equipment. Was intended analyze the variation of the radiation dose in function of the different applied technical parameters, and this way, guide the professionals as for the possibility of obtaining of x-ray images of better quality and smaller patient exposition. For radiation dose measure a detector of solid state was utilized. During the accomplishment of the measures it was verified that there no a general consensus among the technicians of the section being observed differences of the order of 80% in the mAs. In terms of radiation dose measured, the largest value of verified was 4.752 mGy (exam of lateral lumbar column) and the smallest value of 0.165 mGy (child's thorax).The results showed that a standardization in the x-ray techniques executed by the professionals of the section will be able to reduce significantly the radiation exposition of the assisted patients. (author)

  5. IMPLICATIONS OF X-RAY LINE VARIATIONS FOR 4U1822-371

    International Nuclear Information System (INIS)

    Ji, L.; Schulz, N. S.; Nowak, M. A.; Canizares, C. R.

    2011-01-01

    4U 1822-371 is one of the prototype accretion disk coronal sources with an orbital period of about 5.6 hr. The binary is viewed almost edge-on at a high inclination angle of 83 deg., which makes it a unique candidate to study binary orbital and accretion disk dynamics in high powered X-ray sources. We observed the X-ray source in 4U 1822-371 with the Chandra High Energy Transmission Grating Spectrometer for almost nine binary orbits. X-ray eclipse times provide an update of the orbital ephemeris. We find that our result follows the quadratic function implied by previous observations; however, it suggests a flatter trend. From the orbital line dynamics, we confirm the previous suggestion that recombination emission is located at the impact bulge of the accretion stream. Our observations show that the recombining plasma is confined to this region, and prove that it has to be a very thin layer on top of the accretion disk. Fe XXVI emission is detected at all phases and likely originates from the hot central corona which has optical depth <<1. The implied ionization parameters from both regions strongly suggest that the illuminating source is obscured with respect to the observer and is orders of magnitude brighter than what is actually observed. This is independently confirmed by the best fit of a flat power law with a high-energy cutoff and partial covering absorption with a covering fraction of about 50%. We discuss the implications of our findings with respect to the photoionized line emission and the spectral continuum on basic properties of the X-ray source.

  6. Analysis of geomagnetic storm variations and count-rate of cosmic ray muons recorded at the Brazilian southern space observatory

    International Nuclear Information System (INIS)

    Frigo, Everton; Savian, Jairo Francisco; Silva, Marlos Rockenbach da; Lago, Alisson dal; Trivedi, Nalin Babulal; Schuch, Nelson Jorge

    2007-01-01

    An analysis of geomagnetic storm variations and the count rate of cosmic ray muons recorded at the Brazilian Southern Space Observatory -OES/CRS/INPE-MCT, in Sao Martinho da Serra, RS during the month of November 2004, is presented in this paper. The geomagnetic measurements are done by a three component low noise fluxgate magnetometer and the count rates of cosmic ray muons are recorded by a muon scintillator telescope - MST, both instruments installed at the Observatory. The fluxgate magnetometer measures variations in the three orthogonal components of Earth magnetic field, H (North-South), D (East-West) and Z (Vertical), with data sampling rate of 0.5 Hz. The muon scintillator telescope records hourly count rates. The arrival of a solar disturbance can be identified by observing the decrease in the muon count rate. The goal of this work is to describe the physical morphology and phenomenology observed during the geomagnetic storm of November 2004, using the H component of the geomagnetic field and vertical channel V of the multi-directional muon detector in South of Brazil. (author)

  7. Analysis of geomagnetic storm variations and count-rate of cosmic ray muons recorded at the Brazilian southern space observatory

    Energy Technology Data Exchange (ETDEWEB)

    Frigo, Everton [University of Sao Paulo, USP, Institute of Astronomy, Geophysics and Atmospheric Sciences, IAG/USP, Department of Geophysics, Sao Paulo, SP (Brazil); Savian, Jairo Francisco [Space Science Laboratory of Santa Maria, LACESM/CT, Southern Regional Space Research Center, CRS/INPE, MCT, Santa Maria, RS (Brazil); Silva, Marlos Rockenbach da; Lago, Alisson dal; Trivedi, Nalin Babulal [National Institute for Space Research, INPE/MCT, Division of Space Geophysics, DGE, Sao Jose dos Campos, SP (Brazil); Schuch, Nelson Jorge, E-mail: efrigo@iag.usp.br, E-mail: savian@lacesm.ufsm.br, E-mail: njschuch@lacesm.ufsm.br, E-mail: marlos@dge.inpe.br, E-mail: dallago@dge.inpe.br, E-mail: trivedi@dge.inpe.br [Southern Regional Space Research Center, CRS/INPE, MCT, Santa Maria, RS (Brazil)

    2007-07-01

    An analysis of geomagnetic storm variations and the count rate of cosmic ray muons recorded at the Brazilian Southern Space Observatory -OES/CRS/INPE-MCT, in Sao Martinho da Serra, RS during the month of November 2004, is presented in this paper. The geomagnetic measurements are done by a three component low noise fluxgate magnetometer and the count rates of cosmic ray muons are recorded by a muon scintillator telescope - MST, both instruments installed at the Observatory. The fluxgate magnetometer measures variations in the three orthogonal components of Earth magnetic field, H (North-South), D (East-West) and Z (Vertical), with data sampling rate of 0.5 Hz. The muon scintillator telescope records hourly count rates. The arrival of a solar disturbance can be identified by observing the decrease in the muon count rate. The goal of this work is to describe the physical morphology and phenomenology observed during the geomagnetic storm of November 2004, using the H component of the geomagnetic field and vertical channel V of the multi-directional muon detector in South of Brazil. (author)

  8. Steroid hormones and peptide hormones in atopic eczema. Radioimmunological determination of diurnal plasma level variations of testosterone, cortisol, prolactin and human growth factor in healthy volunteers and patients showing atopic eczemae

    International Nuclear Information System (INIS)

    Bock, B.

    1986-01-01

    An analysis of hormone measurements in sera from healthy volunteers and patients that was carried out on the basis of different criteria yielded the following results: 1) The testosterone levels determined in the patients sera were significantly lower than those of the healthy individuals and the daily rhythmic variations seen here did not attain statistical significance. 2) There were no statistically relevant differences in the serum concentrations of cortisol between healthy individuals and patients, nor was the amplitude of the daily variations observed to be changed in a consistent way. 3) In the patients, as compared to the healthy individuals, the prolactin level was considerably increased, as was the amplitude of the daily rhythmic variations. 4) The values determined for the human growth hormone (HCG) varied considerably between the individuals of either group. Since this held true for both the fluctuations with time and the height of the serum concentrations, a statistical analysis of the results appeared pointless. The results confirm that central and autonomous components have an important role in ectopic eczemae. (TRV) [de

  9. Near-surface density profiling of Fe ion irradiated Si (100) using extremely asymmetric x-ray diffraction by variation of the wavelength

    Energy Technology Data Exchange (ETDEWEB)

    Khanbabaee, B., E-mail: khanbabaee@physik.uni-siegen.de; Pietsch, U. [Solid State Physics, University of Siegen, D-57068 Siegen (Germany); Facsko, S. [Helmholtz-Zentrum Dresden-Rossendorf, 01314 Dresden (Germany); Doyle, S. [Synchrotron Light Source ANKA, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen (Germany)

    2014-10-20

    In this work, we report on correlations between surface density variations and ion parameters during ion beam-induced surface patterning process. The near-surface density variations of irradiated Si(100) surfaces were investigated after off-normal irradiation with 5 keV Fe ions at different fluences. In order to reduce the x-ray probing depth to a thickness below 5 nm, the extremely asymmetrical x-ray diffraction by variation of wavelength was applied, exploiting x-ray refraction at the air-sample interface. Depth profiling was achieved by measuring x-ray rocking curves as function of varying wavelengths providing incidence angles down to 0°. The density variation was extracted from the deviations from kinematical Bragg angle at grazing incidence angles due to refraction of the x-ray beam at the air-sample interface. The simulations based on the dynamical theory of x-ray diffraction revealed that while a net near-surface density decreases with increasing ion fluence which is accompanied by surface patterning, there is a certain threshold of ion fluence to surface density modulation. Our finding suggests that the surface density variation can be relevant with the mechanism of pattern formation.

  10. Light rays in static spacetimes with critical asymptotic behavior: A variational approach

    Directory of Open Access Journals (Sweden)

    Valeria Luisi

    2006-09-01

    Full Text Available Let $mathcal{M}=mathcal{M}_{0}imes mathbb{R}$ be a Lorentzian manifold equipped with the static metric $langle cdot ,cdot angle _{z}=langle cdot ,cdot angle -eta (xdt^{2}$. The aim of this paper is investigating the existence of lightlike geodesics joining a point $z_{0}=(x_{0},t_{0}$ to a line $gamma ={ x_{1}} imes mathbb{R}$ when coefficient $eta $ has a quadratic asymptotic behavior by means of a variational approach.

  11. SMLTM simulations of the diurnal tide: comparison with UARS observations

    Directory of Open Access Journals (Sweden)

    R. A. Akmaev

    1997-09-01

    Full Text Available Wind and temperature observations in the mesosphere and lower thermosphere (MLT from the Upper Atmosphere Research Satellite (UARS reveal strong seasonal variations of tides, a dominant component of the MLT dynamics. Simulations with the Spectral mesosphere/lower thermosphere model (SMLTM for equinox and solstice conditions are presented and compared with the observations. The diurnal tide is generated by forcing specified at the model lower boundary and by in situ absorption of solar radiation. The model incorporates realistic parameterizations of physical processes including various dissipation processes important for propagation of tidal waves in the MLT. A discrete multi-component gravity-wave parameterization has been modified to account for seasonal variations of the background temperature. Eddy diffusion is calculated depending on the gravity-wave energy deposition rate and stability of the background flow. It is shown that seasonal variations of the diurnal-tide amplitudes are consistent with observed variations of gravity-wave sources in the lower atmosphere.

  12. Variations in sensitivity of synchronized Chinese hamster cells to oxic and anoxic X-ray exposures

    International Nuclear Information System (INIS)

    Siracka, E.; Littbrand, B.; Clifton, K.H.; Revesz, L.

    1975-01-01

    V-79 Chinese hamster cells in monolayer cultures on glass surfaces were synchronized by treatment with hydroxyurea and then exposed at different times to X-rays in air or in oxygen-free argon. Survival determinations indicated that the oxygen enhancement ratio (OER) as expressed by the ratio of the respective D 0 values varied over a narrow range in the different phases of the cell cycle. These changes resulted from cyclic alterations in both aerobic and anaerobic D 0 values, possibly in n values. (author)

  13. Variation of cosmic-ray flux and global cloud-coverage

    CERN Document Server

    Svensmark, H

    1998-01-01

    There has long been a search for a physical link between solar activity and the earth's climate. The most direct way the Sun could affect the Earth's climate would be through temporal changes in its luminosity, but observations have shown that these small to explain the observed temperature changes. This does not, however exclude the possibility of an indirect physical mechanism. In the talk it will be shown that the excellent correlations observed between solar activity parameters and climate c link between cosmic ray flux and global cloud cover.

  14. Dynamic re-weighted total variation technique and statistic Iterative reconstruction method for x-ray CT metal artifact reduction

    Science.gov (United States)

    Peng, Chengtao; Qiu, Bensheng; Zhang, Cheng; Ma, Changyu; Yuan, Gang; Li, Ming

    2017-07-01

    Over the years, the X-ray computed tomography (CT) has been successfully used in clinical diagnosis. However, when the body of the patient to be examined contains metal objects, the image reconstructed would be polluted by severe metal artifacts, which affect the doctor's diagnosis of disease. In this work, we proposed a dynamic re-weighted total variation (DRWTV) technique combined with the statistic iterative reconstruction (SIR) method to reduce the artifacts. The DRWTV method is based on the total variation (TV) and re-weighted total variation (RWTV) techniques, but it provides a sparser representation than TV and protects the tissue details better than RWTV. Besides, the DRWTV can suppress the artifacts and noise, and the SIR convergence speed is also accelerated. The performance of the algorithm is tested on both simulated phantom dataset and clinical dataset, which are the teeth phantom with two metal implants and the skull with three metal implants, respectively. The proposed algorithm (SIR-DRWTV) is compared with two traditional iterative algorithms, which are SIR and SIR constrained by RWTV regulation (SIR-RWTV). The results show that the proposed algorithm has the best performance in reducing metal artifacts and protecting tissue details.

  15. Variations of the harmonic components of the X-ray pulse profile of PSR B1509–58

    International Nuclear Information System (INIS)

    Pradhan Pragati; Paul Biswajit; Raichur Harsha; Paul Bikash Chandra

    2015-01-01

    We used the Fourier decomposition technique to investigate the stability of the X-ray pulse profile of a young pulsar PSR B1509–58 by studying the relative amplitudes and phase differences of its harmonic components with respect to the fundamental using data from the Rossi X-Ray Timing Explorer. Like most young rotation powered pulsars, PSR B1509–58 has a high spin down rate. It also has less timing noise, allowing accurate measurement of higher order frequency derivatives which in turn helps in the study of the physics of pulsar spin down. Detailed investigation of pulse profiles over the years will help us establish any possible connection between the timing characteristics and the high energy emission characteristics for this pulsar. Furthermore, the study of pulse profiles of short period X-ray pulsars can also be useful when used as a means of interplanetary navigation. The X-ray pulse profile of this source has been analyzed for 15 yr (1996–2011). The long term average amplitudes of the first, second and third harmonics (and their standard deviation for individual measurements) compared to the fundamental are 36.9% (1.7%), 13.4% (1.9%) and 9.4% (1.8%) respectively. Similarly, the phases of the three harmonics (and standard deviations) with respect to the fundamental are 0.36 (0.06), 1.5 (0.2) and 2.5 (0.3) radian respectively. We do not find any significant variation of the harmonic components of the pulse profile in comparison to the fundamental. (research papers)

  16. Response of the upper atmosphere to variations in the solar soft x-ray irradiance. Ph.D. Thesis

    Science.gov (United States)

    Bailey, Scott Martin

    1995-01-01

    Terrestrial far ultraviolet (FUV) airglow emissions have been suggested as a means for remote sensing the structure of the upper atmosphere. The energy which leads to the excitation of FUV airglow emissions is solar irradiance at extreme ultraviolet (EUV) and soft x-ray wavelengths. Solar irradiance at these wavelengths is known to be highly variable; studies of nitric oxide (NO) in the lower thermosphere have suggested a variability of more than an order of magnitude in the solar soft x-ray irradiance. To properly interpret the FUV airflow, the magnitude of the solar energy deposition must be known. Previous analyses have used the electron impact excited Lyman-Birge-Hopfield (LBH) bands of N2 to infer the flux of photoelectrons in the atmosphere and thus to infer the magnitude of the solar irradiance. This dissertation presents the first simultaneous measurements of the FUV airglow, the major atmospheric constituent densities, and the solar EUV and soft x-ray irradiances. The measurements were made on three flights of an identical sounding rocket payload at different levels of solar activity. The linear response in brightness of the LBH bands to variations in solar irradiance is demonstrated. In addition to the N2 LBH bands, atomic oxygen lines at 135.6 and 130.4 nm are also studied. Unlike the LBH bands, these emissions undergo radiative transfer effects in the atmosphere. The OI emission at 135.6 nm is found to be well modeled using a radiative transfer calculation and the known excitation processes. Unfortunately, the assumed processes leading to OI 130.4 nm excitation are found to be insufficient to reproduce the observed variability of this emission. Production of NO in the atmosphere is examined; it is shown that a lower than previously reported variability in the solar soft x-ray irradiance is required to explain the variability of NO.

  17. Photoneutron intensity variation with field size around radiotherapy linear accelerator 18-MeV X-ray beam

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghamdi, H.; Fazal-ur-Rehman [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Jarallah, M.I. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)], E-mail: mibrahim@kfupm.edu.sa; Maalej, N. [Physics Department, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2008-08-15

    In X-ray radiotherapy accelerators, neutrons are produced mainly by ({gamma},n) reaction when high energy X-rays interact with high Z materials of the linear accelerator head. These materials include the lead (Pb) used as shielding in the collimator, tungsten (W) target used for the production of X-rays and iron (Fe) in the accelerator head. These unwanted neutrons contaminate the therapeutic beam and contribute to the patient dose during the treatment of a cancer patient. Knowing the neutron distribution around the radiotherapy accelerator is therefore desired. CR-39 nuclear track detectors (NTDs) were used to study the variation of fast and thermal neutron relative intensities around an 18 MeV linear accelerator X-ray beam with the field sizes of 0, 10x10, 20x20, 30x30 and 40x40cm{sup 2}. For fast neutron detection, bare NTDs were used. For thermal neutron detection, NTDs were covered with lithium tetra borate (Li{sub 2}B{sub 4}O{sub 7}) converters. The NTDs were placed at different locations in the direction perpendicular to the treatment couch (transversal) and in the direction parallel to the treatment couch (longitudinal) with respect to the isocenter of the accelerator. The fast neutron relative intensity is symmetrical about the beam axis and exhibits an exponential-like drop with distance from the isocenter of the accelerator for all the field sizes. At the primary beam (isocenter), the relative fast neutron intensity is highest for 40x40cm{sup 2} field size and decreases linearly with the decrease in the field size. However, fast neutron intensities do not change significantly with beam size for the measurements outside the primary beam. The fast neutron intensity in the longitudinal direction outside the primary beam decreases linearly with the field size. The thermal neutron intensity, at any location, was found to be almost independent of the field size.

  18. Solar activity effects on cosmic ray intensity and geomagnetic field variation

    International Nuclear Information System (INIS)

    Shukla, A.K.; Shukla, J.P.; Sharma, S.M.; Singh, R.L.; Agrawal, S.P.

    1978-01-01

    An analysis has been performed to statistically correlate the date of solar flare occurrence and its importance with the short term cosmic ray intensity decreases (observed by the high latitude neutron monitors) as well as with the geomagnetic field fluctuation indices (Asub(p) and Dsub(st)), during the period 1973-1976. This period has the particular advantage of being close to a solar minimum to avoid the ambiguity due to closely spaced solar flares. It is found that the intensity decrease starts at least 2-3 days after the date of bright solar flares of Imp 1B, 2B or 3B and the amplitude of the decrease increases with the importance of the solar flare. (author)

  19. The day-night variation of cosmic rays intensity at sea level under the influence of meteorological fronts and troughs

    International Nuclear Information System (INIS)

    Mok, H.M.; Cheng, K.M.

    2000-01-01

    The day-night variation of cosmic rays (CR) intensity at sea level has been observed by a simple G-M counter telescope. We perform two 5 hours counting during the day and the night and find that the pattern of variation is closely related to the atmospheric disturbance. The normal pattern shows that the day counts is a few percents lower than that of the night counts. This can be simply explained by the temperature effect. But when our observation station is being affected by a meteorological front or trough, a reversal occurs. At times the reversal pattern occurs even up to a few days ahead the formation of the troughs at a few hundred kilometers away. Such a reversal may lasts for a few days until the influence of the front or trough has significantly weakened. This effect also overrides the barometric effect, except when there is a sharp change of air pressure, such as during the approach of a tropical cyclone. Our further investigation shows that the pattern of variation may be negatively correlated to the altitude of the 0degC level in the atmosphere. A 150 m upward shift of the 0degC level reduces the CR intensity by about 3-4%. Our postulation is that this variation of CR intensity is related to the relativistic effect of the muon decay, and is an indication of the height of the mid-level pressure distribution. The phenomenon should be further investigated for possible application in weather forecasting and better understanding of the phenomenon could be of use in differentiating the atmospheric effect and the solar effects in CR data. (author)

  20. Long-term stability of diurnal salivary cortisol and alpha-amylase secretion patterns.

    Science.gov (United States)

    Skoluda, Nadine; La Marca, Roberto; Gollwitzer, Mario; Müller, Andreas; Limm, Heribert; Marten-Mittag, Birgitt; Gündel, Harald; Angerer, Peter; Nater, Urs M

    2017-06-01

    This study aimed to investigate long-term stability and variability of diurnal cortisol and alpha-amylase patterns. Diurnal cortisol and alpha-amylase secretion patterns were assessed on a single workday with three waves of measurement across a total time period of 24months in 189 participants. Separate hierarchical linear models were analyzed, with and without a number of potential predictor variables (age, BMI, smoking, chronic stress, stress reactivity). While low long-term stability was found in diurnal cortisol, the stability of diurnal alpha-amylase was moderate across the time period of 24months. Several predictor variables had a positive impact on diurnal cortisol and alpha-amylase secretion patterns averaged across waves. Our findings underpin the notion that long-term stability is not necessarily warranted in longitudinal studies. It is important to choose an appropriate study design when attempting to disentangle clinically and biologically relevant changes from naturally occurring variations in diurnal cortisol and alpha-amylase. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Summary of daily observational results of solar phenomena, cosmic ray, geomagnetic variation, ionosphere, radio wave propagation and airglow

    International Nuclear Information System (INIS)

    Anon.

    1976-01-01

    The diagrams in this section of the publication illustrate the summary of daily observational results of solar phenomena, cosmic ray, geomagnetic variation, ionosphere, radio wave propagation and airglow observed in Japan. For convenience, the observational results are arranged by the solar rotation number. The aim of this illustration is to disseminate an outline of daily events observed in Japan for the benefit of active research workers who plan to make detailed study of the specific solar and terrestrial events. Therefore, the illustrations do not show all observational results in Japan but only representative ones at some key stations in Japan. They will suffice for the present purpose. The method of illustration shown in the instruction on the next page is still a preliminary one, and it is subject to change resulting from the kind advice of the users of this part of the publication. We welcome any advice for making the data arrangement and expression better and more convenient. (auth.)

  2. Electronic structure simulation of chromium aluminum oxynitride by discrete variational-X{alpha} method and X-ray photoelectron spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Youngmin; Chang, Hyunju; Lee, Jae Do [Korea Research Inst. of Chemical Technology, Taejon (Korea); Kim, Eunah; No, Kwangsoo [Korea Advanced Inst. of Science and Technology, Taejon (Korea)

    2002-09-01

    We use a first-principles discrete variational (DV)-X{alpha} method to investigate the electronic structure of chromium aluminum oxynitride. When nitrogen is substituted for oxygen in the Cr-Al-O system, the N2p level appears in the energy range between O2p and Cr3d levels. Consequently, the valence band of chromium aluminum oxynitride becomes broader and the band gap becomes smaller than that of chromium aluminum oxide, which is consistent with the photoelectron spectra for the valence band using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). We expect that this valence band structure of chromium aluminum oxynitride will modify the transmittance slope which is a requirement for photomask application. (author)

  3. Electronic structure simulation of chromium aluminum oxynitride by discrete variational-Xα method and X-ray photoelectron spectroscopy

    International Nuclear Information System (INIS)

    Choi, Youngmin; Chang, Hyunju; Lee, Jae Do; Kim, Eunah; No, Kwangsoo

    2002-01-01

    We use a first-principles discrete variational (DV)-Xα method to investigate the electronic structure of chromium aluminum oxynitride. When nitrogen is substituted for oxygen in the Cr-Al-O system, the N2p level appears in the energy range between O2p and Cr3d levels. Consequently, the valence band of chromium aluminum oxynitride becomes broader and the band gap becomes smaller than that of chromium aluminum oxide, which is consistent with the photoelectron spectra for the valence band using X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS). We expect that this valence band structure of chromium aluminum oxynitride will modify the transmittance slope which is a requirement for photomask application. (author)

  4. DIURNAL CHANGES IN LEAF PHOTOSYNTHESIS AND RELATIVE WATER CONTENT OF GRAPEVINE

    Directory of Open Access Journals (Sweden)

    Monica Popescu

    2014-11-01

    Full Text Available Variation in light intensity, air temperature and relative air humidity leads to diurnal variations of photosynthetic rate and leaf relative water content. In order to determine the diurnal changes in net photosynthetic rate of vine plants and influence of the main environmental factors, gas exchange in the vine leaves were measure using a portable plant CO2 analysis package. The results show that diurnal changes in photosynthetic rate could be interpreted as single-peak curve, with a maximum at noon (10.794 μmol CO2 m-2 s-1. Leaf relative water content has maximum value in the morning; the values may slightly decrease during the day (day of June, with normal temperature, no rain, no water restriction in soil.

  5. Diurnal levels of immunoreactive erythropoietin in normal subjects and subjects with chronic lung disease

    Energy Technology Data Exchange (ETDEWEB)

    Miller, M.E.; Garcia, J.F.; Cohen, R.A.; Cronkite, E.P.; Moccia, G.; Acevedo, J.

    1981-10-01

    Serum levels of immunoreactive erythropoietin (Ep) were measured in 48 normal male and female volunteers, ages 20-60 years, to establish a control value for Ep of 18.5 +/- 5.0 (mean +/- SD) mU/ml. Levels of the hormone were also measured sequentially over a 24 h period of time in an additional 17 normal volunteers with no diurnal variation. Diurnal levels of immunoreactive Ep were also measured in 30 subjects, with chronic lung disease. These patients, in contrast to normal subjects exhibited a diurnal variation in the level of immunoreactive Ep with peak levels occurring at midnight. The only variable measured which correlated with the serum immunoreactive Ep level in subjects with chronic lung disease was the level of carboxyhaemoglobin (P less than 0.02).

  6. Induced variation in protein mutants after multiple EMS and X-ray treatments

    International Nuclear Information System (INIS)

    Walther, H.; Seibold, K.H.

    1978-01-01

    Results from two experiments with spring barley in the M 3 and M 8 generations gave information on the efficiency of selected mutants, improved in protein yield by different mutagenic treatments. A selection rate of 1-2% was found to be realistic according to a 5% significance level. However, differences between mutagenic treatments with EMS and X-rays and between varieties were found to be not only incidental. To evaluate the results within a protein mutation breeding programme a bivariate selection model was applied and was found to allow clear decisions on mutagenic improvements in protein production, measured in g protein/m 2 . When substituting protein yield in g/seed for protein yield in g/m 2 in the early generations, all relations to protein and grain yield in g/m 2 were found to be low and negative. We conclude that this substituted selection character can be of only limited aid. But very high positive correlations exist between protein yield/m 2 , lysine yield/m 2 and grain yield/m 2 , which means that these selection characters would render a more reliable basis for selection in early generations. (author)

  7. Variations in Solar Parameters and Cosmic Rays with Solar Magnetic Polarity

    Energy Technology Data Exchange (ETDEWEB)

    Oh, S. [Department of Earth Science Education, Chonnam National University, Gwangju, 61186 (Korea, Republic of); Yi, Y., E-mail: suyeonoh@jnu.ac.kr [Department of Astronomy, Space Science and Geology, Chungnam National University, Daejeon, 34134 (Korea, Republic of)

    2017-05-01

    The sunspot number varies with the 11-year Schwabe cycle, and the solar magnetic polarity reverses every 11 years approximately at the solar maximum. Because of polarity reversal, the difference between odd and even solar cycles is seen in solar activity. In this study, we create the mean solar cycle expressed by phase using the monthly sunspot number for all solar cycles 1–23. We also generate the mean solar cycle for sunspot area, solar radio flux, and cosmic ray flux within the allowance of observational range. The mean solar cycle has one large peak at solar maximum for odd solar cycles and two small peaks for most even solar cycles. The odd and even solar cycles have the statistical difference in value and shape at a confidence level of at least 98%. For solar cycles 19–23, the second peak in the even solar cycle is larger than the first peak. This result is consistent with the frequent solar events during the declining phase after the solar maximum. The difference between odd and even solar cycles can be explained by a combined model of polarity reversal and solar rotation. In the positive/negative polarity, the polar magnetic field introduces angular momentum in the same/opposite direction as/to the solar rotation. Thus the addition/subtraction of angular momentum can increase/decrease the motion of plasma to support the formation of sunspots. Since the polarity reverses at the solar maximum, the opposite phenomenon occurs in the declining phase.

  8. Variation in Depth Dose Data between Open and Wedge Fields for 6 MV X-Rays

    International Nuclear Information System (INIS)

    U, Hong; Ryu, M. S. Samuel; Park, In Kyu

    1989-01-01

    Central axis depth dose data for 6 MV X-rays, including tissue maximum ratios, were measured for wedge fields according to Tatcher equation. In wedge fields, the differences in magnitude which increased with depth, field size, and wedge thickness increased when compared with the corresponding open field data. However, phantom scatter correction factors for wedge fields differed less that 1% from the corresponding open field factors. The differences in central axis percent depth dose between two types of fields indicated beam hardening by the wedge filter. The deviation of percent depth doses and scatter correction factors between the effective wedge field and the nominal wedge field at same angle was negligible. The differences were less than 3.26% between the nominal or effective wedge fields and the open fields for percent depth doses to the depth 7cm in 6cm x 6cm field. For larger (10cm x 10cm) field size, however, the deviation of percent depth doses between the nominal or effective wedge fields and the open fields were greater-dosimetric errors were 3.56% at depth 7cm and nearly 5.30% at 12cm. We suggest that the percent depth doses of individual wedge and wedge transmission factors should be considered for the dose calculation or monitor setting in the treatment of deep seated tumor

  9. Comparison of Optical and Multi-Waveband Variations of Selected Gamma-ray Bright Blazars in 2012

    Science.gov (United States)

    Schultz, Benjamin; Jorstad, S. G.; Marscher, A. P.; Williamson, K. E.; Walker, G. E.

    2013-01-01

    We present multi-wavelength observations of several gamma-ray bright blazars. We combine optical data obtained with the 17-inch CCD telescope of Maria Mitchell Observatory with space- and ground-based observations carried out with a variety of instruments. These include a number of other optical telescopes, the Fermi Gamma-Ray Space Telescope at photon energies of 0.1-200 GeV, and the Swift satellite at 0.3-10 keV plus optical and UV wavelengths. Three of the observed blazars proved to be particularly active - BL Lac, Mrk501, and CTA-102. BL Lac was of special interest, displaying remarkable activity in multiple wavelengths during this observation period, including the optical, in which it underwent its largest observed flare in a number of years. In addition, CTA-102 has recently undergone an unprecedented multi-wavelength outburst. We cross-correlate the variations in the different wavebands in an effort to guide theoretical interpretations of the optical and high-energy emission from blazars. This project was supported by NSF/REU grant AST-0851892 and the Nantucket Maria Mitchell Association. The research at Boston University was supported in part by NSF grant AST-0907893 and by NASA through Fermi grant NNX11AQ03G.

  10. Investigating the origins of nanostructural variations in differential ethnic hair types using X-ray scattering techniques.

    Science.gov (United States)

    Wade, M; Tucker, I; Cunningham, P; Skinner, R; Bell, F; Lyons, T; Patten, K; Gonzalez, L; Wess, T

    2013-10-01

    Human hair is a major determinant of visual ethnic differentiation. Although hair types are celebrated as part of our ethnic diversity, the approach to hair care has made the assumption that hair types are structurally and chemically similar. Although this is clearly not the case at the macroscopic level, the intervention of many hair treatments is at the nanoscopic and molecular levels. The purpose of the work presented here is to identify the main nanoscopic and molecular hierarchical differences across five different ethnic hair types from hair fibres taken exclusively from the scalp. These are Afro (subdivided into elastic 'rubber' and softer non-elastic 'soft'), Chinese, European and Mullato (mixed race). Small angle X-Ray scattering (SAXS) is a technique capable of resolving nanostructural variations in complex materials. Individual hair fibres from different ethnic hair types were used to investigate structural features found in common and also specific to each type. Simultaneous wide angle X-Ray scattering (WAXS) was used to analyse the submolecular level structure of the fibrous keratin present. The data sets from both techniques were analysed with principal component analysis (PCA) to identify underlying variables. Principal component analysis of both SAXS and WAXS data was shown to discriminate the scattering signal between different hair types. The X-ray scattering results show a common underlying keratin intermediate filament (KIF) structure. However, distinct differences were observed in the preferential orientation and intensity signal from the lipid component of the hair. In addition, differences were observed in the intensity distribution of the very low-angle sample-dependent diffuse scatter surrounding the 'beamstop.' The results indicate that the fibrous keratin scaffold remains consistent between ethnic hair types. The hierarchies made by these may be modulated by variation in the content of keratin-associated proteins (KAPs) and lipids that

  11. Dynamic Processes in Be Star Atmospheres. VI. Simultaneous X-Ray, Ultraviolet, and Optical Variations in λ Eridani

    Science.gov (United States)

    Smith, Myron A.; Murakami, T.; Ezuka, H.; Anandarao, B. G.; Chakraborty, A.; Corcoran, M. F.; Hirata, R.

    1997-05-01

    We document the results of simultaneous wavelength monitoring of the B2e star λ Eri. This campaign was carried out from ground stations and with the ROSAT, ASCA, IUE, and Voyager 2 space platforms during a week in 1995 February-March a smaller follow-up was conducted in 1995 September. During the first of these intervals λ Eri exhibited extraordinary wind and disk-ejection activity. The ROSAT/HRI X-ray light curves showed no large flares such as the one the ROSAT/PSPC observed in 1991. However, possible low-level fluctuations in the February-March ROSAT data occurred at the same time as unusual activity in Hα, He I λ6678, He II λ1640, and the C IV doublet. For example, the hydrogen and helium lines exhibited an emission in the blue half of their profiles, probably lasting several hours. The C IV lines showed a strong high-velocity discrete absorption component (DAC) accompanied by unusually strong absorption at lower velocities. The helium line activity suggests that a mass ejection occurred at the base of the wind, while the strong C III (Voyager) and C IV (IUE) lines imply that shock interactions occurred in the wind flow. It is not clear that the X-ray elevations are directly related to the strong C IV absorptions because the former changed on a much more rapid timescale than absorptions in the C IV lines. Within hours of the mild X-ray flux variations found by ROSAT on February 28, the Voyager UV spectrometer (UVS) observed a ``ringing'' that decayed over three 3 hr cycles. The amplitude of these fluctuations was strong (50%) at 950-1100 Å, decreased rapidly with wavelength, and faded to nondetection longward of 1300 Å. Various considerations indicate that these continuum variations were not due to an instrumental pathology in the UVS. Rather, they appear to be due to a time-dependent flux deficit in the 950-1250 Å region. We outline a scenario in which a dense plasma structure over the star's surface is heated and cooled quasi-periodically to produce

  12. Automated computer analysis of x-ray radiographs greatly facilitates measurement of coating-thickness variations in laser-fusion targets

    International Nuclear Information System (INIS)

    Stupin, D.M.; Moore, K.R.; Thomas, G.D.; Whitman, R.L.

    1981-01-01

    An automated system was built to analyze x-ray radiographs of laser fusion targets which greatly facilitates the detection of coating thickness variations. Many laser fusion targets reqire opaque coatings 1 to 20 μm thick which have been deposited on small glass balloons 100 to 500 μm in diameter. These coatings must be uniformly thick to 1% for the targets to perform optimally. Our system is designed to detect variations as small as 100 A in 1-μm-thick coatings by converting the optical density variations of contact x-ray radiographs into coating thickness variations. Radiographic images are recorded in HRP emulsions and magnified by an optical microscope, imaged onto television camera, digitized and processed on a Data General S/230 computer with a code by Whitman. After an initial set-up by the operator, as many as 200 targets will be automatically characterized

  13. Oral Contraceptives and Renal Water Handling; A diurnal study in young women

    DEFF Research Database (Denmark)

    Graugaard-Jensen, Charlotte; Hvistendahl, Gitte M; Frøkiær, Jørgen

    2017-01-01

    To test the hypothesis that use of oral contraceptives (OC) changes diurnal variation in fluid balance mechanisms including blood pressure, secretion of vasopressin and oxytocin, and renal water and electrolyte excretion. Fifteen naturally cycling (NC) women in mid-follicular phase and 11 long-te...

  14. Diurnal and semi-diurnal tidal currents in the deep mid-Arabian sea

    Digital Repository Service at National Institute of Oceanography (India)

    Shenoi, S.S.C.; Gouveia, A.D.; Shetye, S.R.

    Current meter records from two depths, approximately 1000 m, at three mooring in the deep mid-Arabian Sea were used to study tidal components. Tidal ellipses for the semi-diurnal (M2, S2 and K2) and the diurnal (K1 and P1) tidal constituents have...

  15. Insights into the diurnal cycle of global Earth outgoing radiation using a numerical weather prediction model

    Science.gov (United States)

    Gristey, Jake J.; Chiu, J. Christine; Gurney, Robert J.; Morcrette, Cyril J.; Hill, Peter G.; Russell, Jacqueline E.; Brindley, Helen E.

    2018-04-01

    A globally complete, high temporal resolution and multiple-variable approach is employed to analyse the diurnal cycle of Earth's outgoing energy flows. This is made possible via the use of Met Office model output for September 2010 that is assessed alongside regional satellite observations throughout. Principal component analysis applied to the long-wave component of modelled outgoing radiation reveals dominant diurnal patterns related to land surface heating and convective cloud development, respectively explaining 68.5 and 16.0 % of the variance at the global scale. The total variance explained by these first two patterns is markedly less than previous regional estimates from observations, and this analysis suggests that around half of the difference relates to the lack of global coverage in the observations. The first pattern is strongly and simultaneously coupled to the land surface temperature diurnal variations. The second pattern is strongly coupled to the cloud water content and height diurnal variations, but lags the cloud variations by several hours. We suggest that the mechanism controlling the delay is a moistening of the upper troposphere due to the evaporation of anvil cloud. The short-wave component of modelled outgoing radiation, analysed in terms of albedo, exhibits a very dominant pattern explaining 88.4 % of the variance that is related to the angle of incoming solar radiation, and a second pattern explaining 6.7 % of the variance that is related to compensating effects from convective cloud development and marine stratocumulus cloud dissipation. Similar patterns are found in regional satellite observations, but with slightly different timings due to known model biases. The first pattern is controlled by changes in surface and cloud albedo, and Rayleigh and aerosol scattering. The second pattern is strongly coupled to the diurnal variations in both cloud water content and height in convective regions but only cloud water content in marine

  16. Diurnal-and sex-related difference of metallothionein expression in mice

    Directory of Open Access Journals (Sweden)

    Zhang Dan

    2012-07-01

    Full Text Available Abstract Background Metallothionein (MT is a small, cysteine-rich, metal-binding protein that plays an important role in protecting against toxicity of heavy metal and chemicals. This study was aimed to define diurnal and sex variation of MT in mice. Methods Adult mice were maintained in light- and temperature-controlled facilities for 2 weeks with light on at 8:00 and light off at 20:00. The blood, liver, and kidneys were collected every 4 h during the 24 h period. Total RNA was isolated, purified, and subjected to real-time RT-PCR analysis and MT protein was determined by western blot and the Cd/hemoglobin assay. Results The diurnal variations in mRNA levels of MT-1 and MT-2in liver were dramatic, up to a 40-foldpeak/trough ratio. MT mRNA levels in kidneys and blood also showed diurnal variation, up to 5-fold peak/trough ratio. The diurnal variation of MT mRNAs resembled the clock gene albumin site D-binding protein (Dbp, and was anti-phase to the clock gene Brain and Muscle ARNT-like Protein 1 (Bmal1 in liver and kidneys. The peaks of MT mRNA levels were higher in females than in males. Hepatic MT protein followed a similar pattern, with about a 3-fold difference. Conclusion MT mRNA levels and protein showed diurnal- and sex-variation in liver, kidney, and blood of mice, which could impact the body defense against toxic stimuli.

  17. Adaptive-weighted total variation minimization for sparse data toward low-dose x-ray computed tomography image reconstruction.

    Science.gov (United States)

    Liu, Yan; Ma, Jianhua; Fan, Yi; Liang, Zhengrong

    2012-12-07

    Previous studies have shown that by minimizing the total variation (TV) of the to-be-estimated image with some data and other constraints, piecewise-smooth x-ray computed tomography (CT) can be reconstructed from sparse-view projection data without introducing notable artifacts. However, due to the piecewise constant assumption for the image, a conventional TV minimization algorithm often suffers from over-smoothness on the edges of the resulting image. To mitigate this drawback, we present an adaptive-weighted TV (AwTV) minimization algorithm in this paper. The presented AwTV model is derived by considering the anisotropic edge property among neighboring image voxels, where the associated weights are expressed as an exponential function and can be adaptively adjusted by the local image-intensity gradient for the purpose of preserving the edge details. Inspired by the previously reported TV-POCS (projection onto convex sets) implementation, a similar AwTV-POCS implementation was developed to minimize the AwTV subject to data and other constraints for the purpose of sparse-view low-dose CT image reconstruction. To evaluate the presented AwTV-POCS algorithm, both qualitative and quantitative studies were performed by computer simulations and phantom experiments. The results show that the presented AwTV-POCS algorithm can yield images with several notable gains, in terms of noise-resolution tradeoff plots and full-width at half-maximum values, as compared to the corresponding conventional TV-POCS algorithm.

  18. Diurnal variation of zooplankton in Malad creek, Bombay

    Digital Repository Service at National Institute of Oceanography (India)

    Gajbhiye, S.N.; Nair, V.R.; Desai, B.N.

    stock and total population were higher in night than in day collections. Abundance and diversity of zooplankton were directly correlated to the prevailing tide and pollution load. Copepods formed the predominant group followed by decapods, gastropods...

  19. Diurnal Variation In The Haematological Values Of The African Giant ...

    African Journals Online (AJOL)

    EMAIL FULL TEXT EMAIL FULL TEXT · DOWNLOAD FULL TEXT DOWNLOAD FULL TEXT · http://dx.doi.org/10.4314/tv.v24i1-2.4581 · AJOL African Journals Online. HOW TO USE AJOL... for Researchers · for Librarians · for Authors · FAQ's · More about AJOL · AJOL's Partners · Terms and Conditions of Use · Contact AJOL ...

  20. Diurnal Patterns and Correlates of Older Adults' Sedentary Behavior.

    Directory of Open Access Journals (Sweden)

    Jelle Van Cauwenberg

    Full Text Available Insights into the diurnal patterns of sedentary behavior and the identification of subgroups that are at increased risk for engaging in high levels of sedentary behavior are needed to inform potential interventions for reducing older adults' sedentary time. Therefore, we examined the diurnal patterns and sociodemographic correlates of older adults' sedentary behavior(s.Stratified cluster sampling was used to recruit 508 non-institutionalized Belgian older adults (≥ 65 years. Morning, afternoon, evening and total sedentary time was assessed objectively using accelerometers. Specific sedentary behaviors, total sitting time and sociodemographic attributes were assessed using an interviewer-administered questionnaire.Participants self-reported a median of 475 (Q1-Q3 = 383-599 minutes/day of total sitting time and they accumulated a mean of 580 ± 98 minutes/day of accelerometer-derived sedentary time. Sedentary time was lowest during the morning and highest during the evening. Older participants were as sedentary as younger participants during the evening, but they were more sedentary during daytime. Compared to married participants, widowers were more sedentary during daytime. Younger participants (< 75 years, men and the higher educated were more likely to engage in (high levels of sitting while driving a car and using the computer. Those with tertiary education viewed 29% and 22% minutes/day less television compared to those with primary or secondary education, respectively. Older participants accumulated 35 sedentary minutes/day more than did younger participants and men accumulated 32 sedentary minutes/day more than did women.These findings highlight diurnal variations and potential opportunities to tailor approaches to reducing sedentary time for subgroups of the older adult population.

  1. Leaf surface wetness and evaporation studies with a β-ray gauge

    International Nuclear Information System (INIS)

    Barthakur, N.N.

    1984-01-01

    Surface wetness duration was measured by a β-ray gauge as a function of wind velocity in the laboratory. The instrument was field-tested as a dewmeter over a wax bean canopy. Diurnal variations of the net count rate through a turgid tobacco leaf measured by a β-ray gauge system corresponded with the stomatal movement. The approximate exponential relationship of the transmission of β-particles with absorber thickness was found acceptable to study rates of evaporation from free water and through pores. The cumulative rate of evaporation of free water varied linearly with time. Three distinct stages of evaporation rates were observed through a porous medium. (author)

  2. Prediction of galactic cosmic ray intensity variation for a few (up to 10-12 years ahead on the basis of convection-diffusion and drift model

    Directory of Open Access Journals (Sweden)

    L. I. Dorman

    2005-11-01

    Full Text Available We determine the dimension of the Heliosphere (modulation region, radial diffusion coefficient and other parameters of convection-diffusion and drift mechanisms of cosmic ray (CR long-term variation, depending on particle energy, the level of solar activity (SA and general solar magnetic field. This important information we obtain on the basis of CR and SA data in the past, taking into account the theory of convection-diffusion and drift global modulation of galactic CR in the Heliosphere. By using these results and the predictions which are regularly published elsewhere of expected SA variation in the near future and prediction of next future SA cycle, we may make a prediction of the expected in the near future long-term cosmic ray intensity variation. We show that by this method we may make a prediction of the expected in the near future (up to 10-12 years, and may be more, in dependence for what period can be made definite prediction of SA galactic cosmic ray intensity variation in the interplanetary space on different distances from the Sun, in the Earth's magnetosphere, and in the atmosphere at different altitudes and latitudes.

  3. Pathophysiology of diurnal drooling in Parkinson's disease

    NARCIS (Netherlands)

    Kalf, J.G.; Munneke, M.; Engel-Hoek, L. van den; Swart, B.J.M. de; Borm, G.F.; Bloem, B.R.; Zwarts, M.J.

    2011-01-01

    Drooling is an incapacitating feature of Parkinson's disease. Better pathophysiological insights are needed to improve treatment. In this study, we tested the hypothesis that the cause of drooling is multifactorial. We examined 15 patients with Parkinson's disease with distinct diurnal saliva loss

  4. Robust fitting of diurnal brightness temperature cycle

    CSIR Research Space (South Africa)

    Udahemuka, G

    2007-11-01

    Full Text Available for a pixel concerned. Robust fitting of observed Diurnal Temperature Cycle (DTC) taken over a day of a given pixel without cloud cover and other abnormally conditions such as fire can give a data based brightness temperature model for a given pixel...

  5. Diurnal temperature asymmetries and fog at Churchill, Manitoba

    Science.gov (United States)

    Gough, William A.; He, Dianze

    2015-07-01

    A variety of methods are available to calculate daily mean temperature. We explore how the difference between two commonly used methods provides insight into the local climate of Churchill, Manitoba. In particular, we found that these differences related closely to seasonal fog. A strong statistically significant correlation was found between the fog frequency (hours per day) and the diurnal temperature asymmetries of the surface temperature using the difference between the min/max and 24-h methods of daily temperature calculation. The relationship was particularly strong for winter, spring and summer. Autumn appears to experience the joint effect of fog formation and the radiative effect of snow cover. The results of this study suggests that subtle variations of diurnality of temperature, as measured in the difference of the two mean temperature methods of calculation, may be used as a proxy for fog detection in the Hudson Bay region. These results also provide a cautionary note for the spatial analysis of mean temperatures using data derived from the two different methods particularly in areas that are fog prone.

  6. A stochastic differential equation model of diurnal cortisol patterns

    Science.gov (United States)

    Brown, E. N.; Meehan, P. M.; Dempster, A. P.

    2001-01-01

    Circadian modulation of episodic bursts is recognized as the normal physiological pattern of diurnal variation in plasma cortisol levels. The primary physiological factors underlying these diurnal patterns are the ultradian timing of secretory events, circadian modulation of the amplitude of secretory events, infusion of the hormone from the adrenal gland into the plasma, and clearance of the hormone from the plasma by the liver. Each measured plasma cortisol level has an error arising from the cortisol immunoassay. We demonstrate that all of these three physiological principles can be succinctly summarized in a single stochastic differential equation plus measurement error model and show that physiologically consistent ranges of the model parameters can be determined from published reports. We summarize the model parameters in terms of the multivariate Gaussian probability density and establish the plausibility of the model with a series of simulation studies. Our framework makes possible a sensitivity analysis in which all model parameters are allowed to vary simultaneously. The model offers an approach for simultaneously representing cortisol's ultradian, circadian, and kinetic properties. Our modeling paradigm provides a framework for simulation studies and data analysis that should be readily adaptable to the analysis of other endocrine hormone systems.

  7. Termite mounds harness diurnal temperature oscillations for ventilation.

    Science.gov (United States)

    King, Hunter; Ocko, Samuel; Mahadevan, L

    2015-09-15

    Many species of millimetric fungus-harvesting termites collectively build uninhabited, massive mound structures enclosing a network of broad tunnels that protrude from the ground meters above their subterranean nests. It is widely accepted that the purpose of these mounds is to give the colony a controlled microclimate in which to raise fungus and brood by managing heat, humidity, and respiratory gas exchange. Although different hypotheses such as steady and fluctuating external wind and internal metabolic heating have been proposed for ventilating the mound, the absence of direct in situ measurement of internal air flows has precluded a definitive mechanism for this critical physiological function. By measuring diurnal variations in flow through the surface conduits of the mounds of the species Odontotermes obesus, we show that a simple combination of geometry, heterogeneous thermal mass, and porosity allows the mounds to use diurnal ambient temperature oscillations for ventilation. In particular, the thin outer flutelike conduits heat up rapidly during the day relative to the deeper chimneys, pushing air up the flutes and down the chimney in a closed convection cell, with the converse situation at night. These cyclic flows in the mound flush out CO2 from the nest and ventilate the colony, in an unusual example of deriving useful work from thermal oscillations.

  8. Diurnal Solar Energy Conversion and Photoprotection in Rice Canopies.

    Science.gov (United States)

    Meacham, Katherine; Sirault, Xavier; Quick, W Paul; von Caemmerer, Susanne; Furbank, Robert

    2017-01-01

    Genetic improvement of photosynthetic performance of cereal crops and increasing the efficiency with which solar radiation is converted into biomass has recently become a major focus for crop physiologists and breeders. The pulse amplitude modulated chlorophyll fluorescence technique (PAM) allows quantitative leaf level monitoring of the utilization of energy for photochemical light conversion and photoprotection in natural environments, potentially over the entire crop lifecycle. Here, the diurnal relationship between electron transport rate (ETR) and irradiance was measured in five cultivars of rice (Oryza sativa) in canopy conditions with PAM fluorescence under natural solar radiation. This relationship differed substantially from that observed for conventional short term light response curves measured under controlled actinic light with the same leaves. This difference was characterized by a reduced curvature factor when curve fitting was used to model this diurnal response. The engagement of photoprotective processes in chloroplast electron transport in leaves under canopy solar radiation was shown to be a major contributor to this difference. Genotypic variation in the irradiance at which energy flux into photoprotective dissipation became greater than ETR was observed. Cultivars capable of higher ETR at midrange light intensities were shown to produce greater leaf area over time, estimated by noninvasive imaging. © 2017 American Society of Plant Biologists. All Rights Reserved.

  9. The Influence of Roof Material on Diurnal Urban Canyon Breathing

    Science.gov (United States)

    Abuhegazy, Mohamed; Yaghoobian, Neda

    2017-11-01

    Improvements in building energy use, air quality in urban canyons and in general urban microclimates require understanding the complex interaction between urban morphology, materials, climate, and inflow conditions. Review of the literature indicates that despite a long history of valuable urban microclimate studies, more comprehensive approaches are needed to address energy, and heat and flow transport in urban areas. In this study, a more comprehensive simulation of the diurnally varying street canyon flow and associated heat transport is numerically investigated, using Large-eddy Simulation (LES). We use computational modeling to examine the impact of diurnal variation of the heat fluxes from urban surfaces on the air flow and temperature distribution in street canyons with a focus on the role of roof materials and their temperature footprints. A detailed building energy model with a three-dimensional raster-type geometry provides urban surface heat fluxes as thermal boundary conditions for the LES to determine the key aero-thermodynamic factors that affect urban street ventilation.

  10. Estimation of shear velocity contrast for dipping or anisotropic medium from transmitted Ps amplitude variation with ray-parameter

    Science.gov (United States)

    Kumar, Prakash

    2015-12-01

    Amplitude versus offset analysis of P to P reflection is often used in exploration seismology for hydrocarbon exploration. In the present work, the feasibility to estimate crustal velocity structure from transmitted P to S wave amplitude variation with ray-parameter has been investigated separately for dipping layer and anisotropy medium. First, for horizontal and isotropic medium, the approximation of P-to-s conversion is used that is expressed as a linear form in terms of slowness. Next, the intercept of the linear regression has been used to estimate the shear wave velocity contrast (δβ) across an interface. The formulation holds good for isotropic and horizontal layer medium. Application of such formula to anisotropic medium or dipping layer data may lead to erroneous estimation of δβ. In order to overcome this problem, a method has been proposed to compensate the SV-amplitude using shifted version of SH-amplitude, and subsequently transforming SV amplitudes equivalent to that from isotropic or horizontal layer medium as the case may be. Once this transformation has been done, δβ can be estimated using isotropic horizontal layer formula. The shifts required in SH for the compensation are π/2 and π/4 for dipping layer and anisotropic medium, respectively. The effectiveness of the approach has been reported using various synthetic data sets. The methodology is also tested on real data from HI-CLIMB network in Himalaya, where the presence of dipping Moho has already been reported. The result reveals that the average shear wave velocity contrast across the Moho is larger towards the Indian side compared to the higher Himalayan and Tibetan regions.

  11. Variations of the stellar initial mass function in semi-analytical models - II. The impact of cosmic ray regulation

    Science.gov (United States)

    Fontanot, Fabio; De Lucia, Gabriella; Xie, Lizhi; Hirschmann, Michaela; Bruzual, Gustavo; Charlot, Stéphane

    2018-04-01

    Recent studies proposed that cosmic rays (CRs) are a key ingredient in setting the conditions for star formation, thanks to their ability to alter the thermal and chemical state of dense gas in the ultraviolet-shielded cores of molecular clouds. In this paper, we explore their role as regulators of the stellar initial mass function (IMF) variations, using the semi-analytic model for GAlaxy Evolution and Assembly (GAEA). The new model confirms our previous results obtained using the integrated galaxy-wide IMF (IGIMF) theory. Both variable IMF models reproduce the observed increase of α-enhancement as a function of stellar mass and the measured z = 0 excess of dynamical mass-to-light ratios with respect to photometric estimates assuming a universal IMF. We focus here on the mismatch between the photometrically derived (M^app_{\\star }) and intrinsic (M⋆) stellar masses, by analysing in detail the evolution of model galaxies with different values of M_{\\star }/M^app_{\\star }. We find that galaxies with small deviations (i.e. formally consistent with a universal IMF hypothesis) are characterized by more extended star formation histories and live in less massive haloes with respect to the bulk of the galaxy population. In particular, the IGIMF theory does not change significantly the mean evolution of model galaxies with respect to the reference model, a CR-regulated IMF instead implies shorter star formation histories and higher peaks of star formation for objects more massive than 1010.5 M⊙. However, we also show that it is difficult to unveil this behaviour from observations, as the key physical quantities are typically derived assuming a universal IMF.

  12. Diurnal rhythms in psychological reward functioning in healthy young men: 'Wanting', liking, and learning.

    Science.gov (United States)

    Byrne, Jamie E M; Murray, Greg

    2017-01-01

    A range of evidence suggests that human reward functioning is partly driven by the endogenous circadian system, generating 24-hour rhythms in behavioural measures of reward activation. Reward functioning is multifaceted but literature to date is largely limited to measures of self-reported positive mood states. The aim of this study was to advance the field by testing for hypothesised diurnal variation in previously unexplored components of psychological reward: 'wanting', liking, and learning using subjective and behavioural measures. Risky decision making (automatic Balloon Analogue Risk Task), affective responsivity to positive images (International Affective Pictures System), uncued self-reported discrete emotions, and learning-contingent reward (Iowa Gambling Task) were measured at 10.00 hours, 14.00 hours, and 19.00 hours in a counterbalanced repeated measures design with 50 healthy male participants (aged 18-30). As hypothesised, risky decision making (unconscious 'wanting') and ratings of arousal towards positive images (conscious wanting) exhibited a diurnal waveform with indices highest at 14.00 hours. No diurnal rhythm was observed for liking (pleasure ratings to positive images, discrete uncued positive emotions) or in a learning-contingent reward task. Findings reaffirm that diurnal variation in human reward functioning is most pronounced in the motivational 'wanting' components of reward.

  13. Impact of assimilation window length on diurnal features in a Mars atmospheric analysis

    Directory of Open Access Journals (Sweden)

    Yongjing Zhao

    2015-05-01

    Full Text Available Effective simulation of diurnal variability is an important aspect of many geophysical data assimilation systems. For the Martian atmosphere, thermal tides are particularly prominent and contribute much to the Martian atmospheric circulation, dynamics and dust transport. To study the Mars diurnal variability and Mars thermal tides, the Geophysical Fluid Dynamics Laboratory Mars Global Climate Model with the 4D-local ensemble transform Kalman filter (4D-LETKF is used to perform an analysis assimilating spacecraft temperature retrievals. We find that the use of a ‘traditional’ 6-hr assimilation cycle induces spurious forcing of a resonantly enhanced semi-diurnal Kelvin waves represented in both surface pressure and mid-level temperature by forming a wave 4 pattern in the diurnal averaged analysis increment that acts as a ‘topographic’ stationary forcing. Different assimilation window lengths in the 4D-LETKF are introduced to remove the artificially induced resonance. It is found that short assimilation window lengths not only remove the spurious resonance, but also push the migrating semi-diurnal temperature variation at 50 Pa closer to the estimated ‘true’ tides even in the absence of a radiatively active water ice cloud parameterisation. In order to compare the performance of different assimilation window lengths, short-term to mid-range forecasts based on the hour 00 and 12 assimilation are evaluated and compared. Results show that during Northern Hemisphere summer, it is not the assimilation window length, but the radiatively active water ice clouds that influence the model prediction. A ‘diurnal bias correction’ that includes bias correction fields dependent on the local time is shown to effectively reduce the forecast root mean square differences between forecasts and observations, compensate for the absence of water ice cloud parameterisation and enhance Martian atmosphere prediction. The implications of these results for

  14. Diurnal flight behavior of Ichneumonoidea (Insecta: Hymenoptera) related to environmental factors in a tropical dry forest.

    Science.gov (United States)

    González-Moreno, A; Bordera, S; Leirana-Alcocer, J; Delfín-González, H

    2012-06-01

    The biology and behavior of insects are strongly influenced by environmental conditions such as temperature and precipitation. Because some of these factors present a within day variation, they may be causing variations on insect diurnal flight activity, but scant information exists on the issue. The aim of this work was to describe the patterns on diurnal variation of the abundance of Ichneumonoidea and their relation with relative humidity, temperature, light intensity, and wind speed. The study site was a tropical dry forest at Ría Lagartos Biosphere Reserve, Mexico; where correlations between environmental factors (relative humidity, temperature, light, and wind speed) and abundance of Ichneumonidae and Braconidae (Hymenoptera: Ichneumonoidea) were estimated. The best regression model for explaining abundance variation was selected using the second order Akaike Information Criterion. The optimum values of temperature, humidity, and light for flight activity of both families were also estimated. Ichneumonid and braconid abundances were significantly correlated to relative humidity, temperature, and light intensity; ichneumonid also showed significant correlations to wind speed. The second order Akaike Information Criterion suggests that in tropical dry conditions, relative humidity is more important that temperature for Ichneumonoidea diurnal activity. Ichneumonid wasps selected toward intermediate values of relative humidity, temperature and the lowest wind speeds; while Braconidae selected for low values of relative humidity. For light intensity, braconids presented a positive selection for moderately high values.

  15. Diurnal circulations and their multi-scale interaction leading to rainfall over the South China Sea upstream of the Philippines during intraseasonal monsoon westerly wind bursts

    Energy Technology Data Exchange (ETDEWEB)

    Park, Myung-Sook; Elsberry, Russell L. [Naval Postgraduate School, Department of Meteorology, Monterey, CA (United States); Ho, Chang-Hoi [Seoul National University, School of Earth and Environmental Sciences, Seoul (Korea, Republic of); Kim, Jinwon [University of California in Los Angeles, Department of Meteorology, Berkeley, CA (United States)

    2011-10-15

    The morning diurnal precipitation maximum over the coastal sea upstream of the Philippines during intraseasonal westerly wind bursts is examined from observations and numerical model simulations. A well-defined case of precipitation and large-scale circulation over the coastal sea west of the Philippines during 17-27 June 2004 is selected as a representative case. The hypothesis is that the mesoscale diurnal circulation over the Philippines and a large-scale diurnal circulation that is induced by large-scale differential heating over Asian continent and the surrounding ocean interact to produce the offshore precipitation maximum during the morning. Three-hourly combined satellite microwave and infrared rainfall retrievals define the morning rainfall peak during this period, and then later the stratiform rain area extends toward the open sea. A control numerical simulation in which a grid-nudging four-dimensional data assimilation (FDDA) is applied to force the large-scale diurnal circulation represents reasonably well the morning rainfall maximum. An enhanced low-level convergence similar to observations is simulated due to the interaction of the local- and large-scale diurnal circulations. The essential role of the local-scale diurnal circulation is illustrated in a sensitivity test in which the solar zenith angle is fixed at 7 am to suppress this diurnal circulation. The implication for climate diagnosis or modeling of such upstream coastal sea precipitation maxima is that the diurnal variations of both the local- and the large-scale circulations must be taken into consideration. (orig.)

  16. Modelling of diurnal cycle under climate change

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, A V; Bezmenov, K V; Demchenko, P F; Mokhov, I I; Petoukhov, V K [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Atmospheric Physics

    1996-12-31

    The observed diurnal temperature range (DTR) displays remarkable change during last 30 years. Land air DTR generally decreases under global climate warming due to more significant night minimum temperature increase in comparison with day maximum temperature increase. Atmosphere hydrological cycle characteristics change under global warming and possible background aerosol atmosphere content change may cause essential errors in the estimation of DTR tendencies of change under global warming. The result of this study is the investigation of cloudiness effect on the DTR and blackbody radiative emissivity diurnal range. It is shown that in some cases (particularly in cold seasons) it results in opposite change in DTR and BD at doubled CO{sub 2} atmosphere content. The influence of background aerosol is the same as the cloudiness one

  17. Modelling of diurnal cycle under climate change

    Energy Technology Data Exchange (ETDEWEB)

    Eliseev, A.V.; Bezmenov, K.V.; Demchenko, P.F.; Mokhov, I.I.; Petoukhov, V.K. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Atmospheric Physics

    1995-12-31

    The observed diurnal temperature range (DTR) displays remarkable change during last 30 years. Land air DTR generally decreases under global climate warming due to more significant night minimum temperature increase in comparison with day maximum temperature increase. Atmosphere hydrological cycle characteristics change under global warming and possible background aerosol atmosphere content change may cause essential errors in the estimation of DTR tendencies of change under global warming. The result of this study is the investigation of cloudiness effect on the DTR and blackbody radiative emissivity diurnal range. It is shown that in some cases (particularly in cold seasons) it results in opposite change in DTR and BD at doubled CO{sub 2} atmosphere content. The influence of background aerosol is the same as the cloudiness one

  18. The effects of gamma-ray irradiation to strawberry (Fragaria x ananassa Duch.) calli on shoot regeneration, achene formation and morphological variations of regenerants

    International Nuclear Information System (INIS)

    Kasumi, Masakazu

    2002-01-01

    Strawberry (Fragaria x ananassa 'Nyoho') calli, derived from anthers, were irradiated with gamma -ray at dosages from 100 to 1,600 Gy (10 Gy · hr - 1) and their effects on callus growth, plant regeneration, and somaclonal variation were analyzed. The growth of callus and percentage of plant regeneration from the callus were reduced slightly at dosages less than 200 Gy, moderately at 400 Gy, and markedly above 800 Gy. Fruit growth associated with seed fertility (>50 % ) was morphologically normal at less than 100 Gy, whereas achene formation was significantly inhibited above 200 Gy. The percentages of morphological variation in regenerants formed from the irradiated callus were:13.7 (no irradiation), 18.6 (100 Gy), 66.0 (200 Gy), 75.7 (400 Gy), and 97.0 (800 Gy). Furthermore, higher dosages yielded wider variations, e.g., thick and small leaf, light leaf color, white flesh, and long fruit. In some regenerants, more than one morphological aberrations developed, some of which were transmissible to daughter plants. These results revealed that the irradiating strawberry callus with gamma - ray resulted in a higher degree and wider spectrum of somaclonal variation than did simple callus culture. (author)

  19. natalensis) and diurn'al (Rhabdomys pumilio)

    African Journals Online (AJOL)

    The thermo neutral zone for both speCies was found to be at T. = 32 ± 1 °e. Below the lower critical point. Vo. for the diurnal species (R. pumilio) was significantly higher. (p

  20. The effects of the diurnal atmospheric variability on entry, descent and landing on Mars

    Directory of Open Access Journals (Sweden)

    Marčeta D.

    2014-01-01

    Full Text Available Landing on Mars is extremely challenging task due to the fact that the Martian atmosphere is the most hostile environment in the Solar system to perform the entry, descent and landing (EDL process, because it is thick enough to create substantial heating of the entry vehicle but not thick enough to reduce its velocity to the one necessary for safe landing. Beside this, the atmosphere is very dynamic mainly due to high eccentricity of the Martian orbit, obliquity of the orbital to the equatorial plane and close alignment of the winter solstice and the orbital perihelion. Although seasonal variations of atmospheric parameters are significantly larger than the diurnal, it is very important to analyze diurnal cycles as they can significantly change vertical and horizontal atmospheric profiles in very short time intervals. This can present a serious threat to missions which have very precise timings and specific requirements such as the requirement for the daytime landing to enable ground images acquisition during the descent and landing phase. A 3-degrees-of-freedom trajectory integration routine was combined with the Mars Global Reference Atmospheric Model (Mars-GRAM to identify the dependence of the EDL profiles on the diurnal cycles of atmospheric parameters throughout the Martian year. The obtained results show that the influence of the diurnal cycles is the largest at the equator and decreases relatively symmetrically towards the poles with a slightly stronger influence in the northern hemisphere. Also, there is a significant influence of the orbital position of Mars on the effect of diurnal atmospheric variations which causes that, around the orbital perihelion and winter solstice, there is some kind of inversion of the dependance of optimal entry timing on latitude of the landing site comparing to the rest of the Martian year. [Projekat Ministarstva nauke Republike Srbije, br. 176002

  1. Exhaustion measured by the SF-36 vitality scale is associated with a flattened diurnal cortisol profile

    DEFF Research Database (Denmark)

    Lindeberg, Sara I; Eek, Frida; Lindbladh, Eva

    2008-01-01

    cortisol profile. The study population included 78 working individuals. The study group was dichotomised into exhausted and non-exhausted groups by means of the SF-36 vitality scale. Salivary cortisol was measured at three times during 1 workday: at awakening, 30min after awakening, and in the evening....... The results showed that diurnal cortisol variation was significantly reduced in exhausted individuals. The difference in cortisol variation was mainly due to lowered morning cortisol in the exhausted group. Differences in cortisol levels at each sampling time or in mean diurnal output of cortisol were...... not statistically significant. The results would support the notion that exhaustion is associated with HPA axis hypoactivity as assessed by salivary cortisol. Furthermore, the SF-36 vitality provides a measure of exhaustion that may be useful in epidemiological studies in order to explore long-term health effects...

  2. Geometry of the non-thermal emission in SN 1006. Azimuthal variations of cosmic-ray acceleration

    OpenAIRE

    Rothenflug, R.; Ballet, J.; Dubner, Gloria Mabel; Giacani, Elsa Beatriz; Decourchelle, A.; Ferrando, P.

    2017-01-01

    SN 1006 is the prototype of shell supernova remnants, in which non-thermal synchrotron emission dominates the X-ray spectrum. The non-thermal emission is due to the cosmic-ray electrons accelerated behind the blast wave. The X-ray synchrotron emission is due to the highest energy electrons, and is thus a tracer of the maximum energy electrons may reach behind a shock. We have put together all XMM-Newton observations to build a full map of SN 1006. The very low brightness a...

  3. Analysis on diurnal global geomagnetic variability under quiet-time conditions

    OpenAIRE

    Klausner, Virginia; Domingues, Margarete Oliveira; Mendes Jr, Odim; Papa, Andres Reinaldo Rodriguez; Frick, Peter

    2012-01-01

    This paper describes a methodology (or treatment) to establish a representative signal of the global magnetic diurnal variation based on a spatial distribution in both longitude and latitude of a set of magnetic stations as well as their magnetic behavior on a time basis. For that, we apply the Principal Component Analysis (PCA) technique implemented using gapped wavelet transform and wavelet correlation. The continuous gapped wavelet and the wavelet correlation techniques were used to descri...

  4. On the Diurnal Periodicity of Representative Earthquakes in Greece: Comparison of Data from Different Observation Systems

    Science.gov (United States)

    Desherevskii, A. V.; Sidorin, A. Ya.

    2017-12-01

    Due to the initiation of the Hellenic Unified Seismic Network (HUSN) in late 2007, the quality of observation significantly improved by 2011. For example, the representative magnitude level considerably has decreased and the number of annually recorded events has increased. The new observational system highly expanded the possibilities for studying regularities in seismicity. In view of this, the authors revisited their studies of the diurnal periodicity of representative earthquakes in Greece that was revealed earlier in the earthquake catalog before 2011. We use 18 samples of earthquakes of different magnitudes taken from the catalog of Greek earthquakes from 2011 to June 2016 to derive a series of the number of earthquakes for each of them and calculate its average diurnal course. To increase the reliability of the results, we compared the data for two regions. With a high degree of statistical significance, we have obtained that no diurnal periodicity can be found for strongly representative earthquakes. This finding differs from the estimates obtained earlier from an analysis of the catalog of earthquakes at the same area for 1995-2004 and 2005-2010, i.e., before the initiation of the Hellenic Unified Seismic Network. The new results are consistent with the hypothesis of noise discrimination (observational selection) explaining the cause of the diurnal variation of earthquakes with different sensitivity of the seismic network in daytime and nighttime periods.

  5. Efeito da baixa temperatura noturna e do porta-enxerto na variação diurna das trocas gasosas e na atividade fotoquímica de laranjeira 'Val��ncia' Effects of low night temperature and rootstocks on diurnal variation of leaf gas exchange rates and photochemical activity of 'Valência' sweet orange plants

    Directory of Open Access Journals (Sweden)

    Daniela Favero São Pedro Machado

    2010-06-01

    limitações difusivas e metabólicas. Embora, Fv/Fm e Fq'/Fm' em laranjeira 'Valência' sobre 'Cravo' tenham sido mais afetados pelo resfriamento em comparação às laranjeiras sobre 'Swingle', esses não contribuíram para a redução da assimilação de CO² (A. Porém, o frio noturno causou aumento da atividade dos drenos alternativos de elétrons (aumento da relação entre o transporte aparente de elétrons e a assimilação de CO², reduzindo a eficiência aparente de carboxilação de forma mais significante em 'Valência' sobre 'Cravo' do que sobre 'Swingle'. Estes resultados confirmam a hipótese de que a ocorrência de frio noturno afeta a fotossíntese de laranjeira 'Valência' sendo os efeitos do resfriamento dependentes do porta-enxerto.Decreases in photosynthesis during winter season are probably caused by low night temperature, even under non-limiting environmental conditions during the diurnal period. Citrus orchards are formed by grafted plants, being the 'Swingle' citrumelo rootstock recommended in areas with occurrence of low temperatures. However, the physiological mechanisms related to larger growth and crop yield in those plants are poorly understood. The aim of this study was to test the hypothesis that the effect of low night temperature in photosynthesis of sweet orange plants is dependent on the rootstock species, with 'Swingle' citrumelo (Citrus paradise x Poncirus trifoliata inducing higher tolerance to overnight chilling when compared to 'Rangpur' lime (Citrus limonia rootstock. Six-month old 'Valência' (Citrus sinensis sweet orange plants grown in plastic bags (5 L were exposed overnight (12 h to temperatures of 20 and 8 ºC. The thermal treatment was carried out inside a growth chamber where only the upper plant shoots were exposed to temperature variation. Measurements of diurnal courses of leaf gas exchange and photochemical activity were taken under natural environmental conditions. Chilling night caused larger reduction on CO2

  6. Variação diária da emissão de metano em solo cultivado com arroz irrigado no Sul do Brasil Diurnal variation of methane emission from a paddy field under rice cultivation in the Southern Brazil

    Directory of Open Access Journals (Sweden)

    Falberni de Souza Costa

    2008-10-01

    de arroz no Sul do Brasil (região litorânea e Sul do RS e região Sul de SC pelo fato destas apresentarem comportamento diário similar de radiação solar e de temperatura do ar. A adequação do procedimento deve ser confirmada para as demais sub-regiões produtoras do Sul do Brasil, mas principalmente para outras regiões que apresentem condições ambientais diversas.Methane (CH4 has a global warming potential 23 to 32 times higher than carbon dioxide and its emission rate in rice fields should vary daily with water and soil temperature, and plant metabolism. This study aimed to identify the appropriate time interval for air sampling in order to quantify the mean daily CH4 emission rate, key information to future studies aiming the derivation of regional indexes of CH4 emission. Three campaigns were performed to evaluate diurnal variation in CH4 emissions (3h interval from continuously flooded rice (Oryza sativa L. cv. 'IRGA-422 CL' fields at different crop stages (panicle differentiation and ripening and management systems (conventional tillage-CT and no-tillage-NT during 2002/2003 crop season in long-term experiment at the Instituto Rio Grandense do Arroz (IRGA, in Cachoeirinha, RS, Brazil. Static chamber method was used and the air samples collected with polystyrene syringes were analyzed by gas chromatography. Methane emission showed a same diurnal pattern in the three campaigns in the both tillage systems. The maximum range of emission (8-33mg CH4m-2 h-1 was observed in the early afternoon (12.00 to 15.00p.m. followed by a decline to a minimum around midnight to next morning (4-19mg CH4 m-2 h-1, in which fluxes were related to flood water temperature (campaign 1 and 3 or soil temperature (campaign 2. Taking into account the daily emission curves, plus operational aspects like chromatographic analysis of samples into the 24h period after air sampling, the time interval from 9.00 to 12.00a.m. is recommended to studies aiming to evaluate mean daily CH4

  7. Influence of ambient air toxics in open-top chambers on the monoterpene emission of Picea abies. Diurnal and seasonal variation of emissions, and differentiation of needles and bark as emission sources. Der Einfluss natuerlich-phytotoxischer Luft auf die Monoterpen-Emission bei Picea abies in Open-Top-Kammern. Tages- und Jahresgang der Emission und Differenzierung von Nadel- und Rindenemissionen

    Energy Technology Data Exchange (ETDEWEB)

    Juettner, F. (Max-Planck-Institut fuer Limnologie, Ploen (Germany, F.R.). Abt. Oekophysiologie)

    1990-04-01

    Open-top chambers, in which each a 19-years old spruce tree (Picea abies) was growing, were used to determine monoterpene emissions by mass fragmentography. The annual dynamics of the monoterpene emissions corresponded to the air temperature. However, the diurnal dynamics did not follow the course of the temperature. Physiological reactions of the needles are responsible for the temperature independent emission of monoterpenes during the day. (orig.).

  8. TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002

    NARCIS (Netherlands)

    Law, R. M.; Peters, W.; Roedenbeck, C.; Aulagnier, C.; Baker, I.; Bergmann, D. J.; Bousquet, P.; Brandt, J.; Bruhwiler, L.; Cameron-Smith, P. J.; Christensen, J. H.; Delage, F.; Denning, A. S.; Fan, S.; Geels, C.; Houweling, S.; Imasu, R.; Karstens, U.; Kawa, S. R.; Kleist, J.; Krol, M. C.; Lin, S. -J.; Lokupitiya, R.; Maki, T.; Maksyutov, S.; Niwa, Y.; Onishi, R.; Parazoo, N.; Patra, P. K.; Pieterse, G.; Rivier, L.; Satoh, M.; Serrar, S.; Taguchi, S.; Takigawa, M.; Vautard, R.; Vermeulen, A. T.; Zhu, Z.

    2008-01-01

    [1] A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, fossil, and air-sea exchange of CO2 and for SF6 and radon for 2000-2003. Twenty-five models or model

  9. TransCom model simulations of hourly atmospheric CO2: Experimental overview and diurnal cycle results for 2002

    NARCIS (Netherlands)

    Law, R. M.; Peters, W.; RöDenbeck, C.; Aulagnier, C.; Baker, I.; Bergmann, D. J.; Bousquet, P.; Brandt, J.; Bruhwiler, L.; Cameron-Smith, P. J.; Christensen, J. H.; Delage, F.; Denning, A. S.; Fan, S.; Geels, C.; Houweling, S.; Imasu, R.; Karstens, U.; Kawa, S. R.; Kleist, J.; Krol, M. C.; Lin, S.-J.; Lokupitiya, R.; Maki, T.; Maksyutov, S.; Niwa, Y.; Onishi, R.; Parazoo, N.; Patra, P. K.; Pieterse, G.; Rivier, L.; Satoh, M.; Serrar, S.; Taguchi, S.; Takigawa, M.; Vautard, R.; Vermeulen, A. T.; Zhu, Z.

    2008-01-01

    A forward atmospheric transport modeling experiment has been coordinated by the TransCom group to investigate synoptic and diurnal variations in CO2. Model simulations were run for biospheric, fossil, and air-sea exchange of CO2 and for SF6 and radon for 2000-2003. Twenty-five models or model

  10. Variation in sensitivity to #betta#-ray-induced chromosomal aberrations during the mitotic cycle of the sea urchin egg

    International Nuclear Information System (INIS)

    Ejima, Y.; Nakamura, I.; Shiroya, T.

    1982-01-01

    Sea urchin eggs were irradiated with 137 Cs #betta# rays at various stages of the mitotic cycle, and chromosomal aberrations at the first postirradiation mitosis and embryonic abnormalities at later developmental stages were examined. The radiosensitivity of the eggs to both endpoints varied in parallel with the mitotic stage at the time of irradiation, suggesting a possible relationship between chromosomal damage and embryonic abnormalities

  11. Numerical variation of cell lysosomes of the proximal convoluted tubules of mice Kidneys submitted to different X-ray doses

    International Nuclear Information System (INIS)

    Silva Lapa, R. de C.R. da; Pacheco, I.P.; Segreto, C.

    1984-01-01

    The number of cell lysosomes of the proximal convoluted tubules of mice Kidneys (Mus musculus) before and after whole-body irradiation with different X-ray doses is confronted. The mice were sacrificed after 72 hours and the cortex fragments were conduct to electron microscopy. A statistically significant numerical reduction of the lysosomas was observed in 72 hours. (M.A.C.) [pt

  12. Diurnal tides in the Arctic Ocean

    Science.gov (United States)

    Kowalik, Z.; Proshutinsky, A. Y.

    1993-01-01

    A 2D numerical model with a space grid of about 14 km is applied to calculate diurnal tidal constituents K(1) and O(1) in the Arctic Ocean. Calculated corange and cotidal charts show that along the continental slope, local regions of increased sea level amplitude, highly variable phase and enhanced currents occur. It is shown that in these local regions, shelf waves (topographic waves) of tidal origin are generated. In the Arctic Ocean and Northern Atlantic Ocean more than 30 regions of enhanced currents are identified. To prove the near-resonant interaction of the diurnal tides with the local bottom topography, the natural periods of oscillations for all regions have been calculated. The flux of energy averaged over the tidal period depicts the gyres of semitrapped energy, suggesting that the shelf waves are partially trapped over the irregularities of the bottom topography. It is shown that the occurrence of near-resonance phenomenon changes the energy flow in the tidal waves. First, the flux of energy from the astronomical sources is amplified in the shelf wave regions, and afterwards the tidal energy is strongly dissipated in the same regions.

  13. Sulfur redox chemistry governs diurnal antimony and arsenic cycles at Champagne Pool, Waiotapu, New Zealand

    Science.gov (United States)

    Ullrich, Maria K.; Pope, James G.; Seward, Terry M.; Wilson, Nathaniel; Planer-Friedrich, Britta

    2013-07-01

    Champagne Pool, a sulfidic hot spring in New Zealand, exhibits distinct diurnal variations in antimony (Sb) and arsenic (As) concentrations, with daytime high and night-time low concentrations. To identify the underlying mobilization mechanisms, five sites along the drainage channel of Champagne Pool were sampled every 2 h during a 24 h period. Temporal variations in elemental concentrations and Sb, As, and sulfur (S) speciation were monitored in the discharging fluid. Total trace element concentrations in filtered and unfiltered samples were analyzed using ICP-MS, and Sb, As and S species were determined by IC-ICP-MS. Sulfur speciation in the drainage channel was dominated by thiosulfate and sulfide at night, while sulfate dominated during the day. The distinct diurnal changes suggest that the transformations are caused by phototrophic sulfur-oxidizing bacteria. These bacteria metabolize thiosulfate and sulfide in daylight to form sulfate and, as suggested by modeling with PhreeqC, elemental sulfur. Sulfide consumption during the day results in undersaturation of antimony sulfides, which triggers the additional release of dissolved Sb. For As, diurnal cycles were much more pronounced in speciation than in total concentrations, with di- and trithioarsenate forming at night due to excess sulfide, and monothioarsenate forming from arsenite and elemental sulfur during the day. Sulfur speciation was thus found to control Sb and As in terms of both solubility and speciation.

  14. ORBITAL VARIATION OF THE X-RAY EMISSION FROM THE DOUBLE NEUTRON STAR BINARY J1537+1155

    International Nuclear Information System (INIS)

    Durant, Martin; Kargaltsev, Oleg; Volkov, Igor; Pavlov, George G.

    2011-01-01

    We observed the double neutron star binary (DNSB) containing PSR J1537+1155 (also known as B1534+12) with the Chandra X-Ray Observatory. This is one of the two DNSBs detected in X-rays and the only one where a hint of variability with orbital phase was found (in the previous Chandra observation). Our follow-up observation supports the earlier result: the distribution of photon arrival times with orbital phase again shows a deficit around apastron. The significance of the deficit in the combined data set exceeds 99%. Such an orbital light curve suggests that the X-ray emission is seen only when neutron star (NS) B passes through the equatorial pulsar wind of NS A. We describe statistical tests that we used to determine the significance of the deficit, and conclusions that can be drawn from its existence, such as interaction of the pulsar wind with the NS companion. We also provide better constrained spectral model parameters obtained from the joint spectral fits to the data from both observations. A power law successfully fits the data, with best-fit photon index Γ = 3.1 ± 0.4 and unabsorbed flux f = (3.2 ± 0.8) × 10 –15 erg s –1 cm –2 (0.3-8 keV range).

  15. Diurnal modulation due to self-interacting mirror and hidden sector dark matter

    International Nuclear Information System (INIS)

    Foot, R.

    2012-01-01

    Mirror and more generic hidden sector dark matter models can simultaneously explain the DAMA, CoGeNT and CRESST-II dark matter signals consistently with the null results of the other experiments. This type of dark matter can be captured by the Earth and shield detectors because it is self-interacting. This effect will lead to a diurnal modulation in dark matter detectors. We estimate the size of this effect for dark matter detectors in various locations. For a detector located in the northern hemisphere, this effect is expected to peak in April and can be detected for optimistic parameter choices. The diurnal variation is expected to be much larger for detectors located in the southern hemisphere. In particular, if the CoGeNT detector were moved to e.g. Sierra Grande, Argentina then a 5σ dark matter discovery would be possible in around 30 days of operation

  16. Changes in growth and yield characters and in genetic variation of peanut (Arachis hypogaea L.) plants due to gamma ray irradiation

    International Nuclear Information System (INIS)

    Kassem, M.; Esawy, W.A.

    2003-01-01

    Air dried seeds of two peanut cultivars Giza 4 and Giza 5 were subjected to irradiation treatments of Co 6 0 gamma ray doses i.e. 0, 100, 150, 200, 250 Gy to study their effect on growth characters, yield components, genetic variation, heritability and genetic advance for election; during 2000 and 2001 summer seasons. Results indicated that, the 100 Gy treatment produced the highest means of most growth characters in M 1 and M 2 generations, however the 250 Gy treatment produced the highest means for No. of pods/plant, pod yield/plant, seed yield/plant and shelling percentage in M 1 generation, but the 200 Gy treatment produced the highest means of yield components in M 2 generation for the two cultivars Giza 4 Giza 5. In general, mean percentages of oil and protein were decreased by increasing gamma ray doses in M 1 and M 2 generations for both Giza 4 and Giza 5. The highest estimates of phenotypic and genotypic coefficient of variation, heritability and genetic advance under selection were obtained with 250 Gy dose for most growth characters and yield components as well as oil and protein percentages of the two cultivars in both M 1 and M 2 generations

  17. Genetic architecture of local adaptation in lunar and diurnal emergence times of the marine midge Clunio marinus (Chironomidae, Diptera).

    Science.gov (United States)

    Kaiser, Tobias S; Heckel, David G

    2012-01-01

    Circadian rhythms pre-adapt the physiology of most organisms to predictable daily changes in the environment. Some marine organisms also show endogenous circalunar rhythms. The genetic basis of the circalunar clock and its interaction with the circadian clock is unknown. Both clocks can be studied in the marine midge Clunio marinus (Chironomidae, Diptera), as different populations have different local adaptations in their lunar and diurnal rhythms of adult emergence, which can be analyzed by crossing experiments. We investigated the genetic basis of population variation in clock properties by constructing the first genetic linkage map for this species, and performing quantitative trait locus (QTL) analysis on variation in both lunar and diurnal timing. The genome has a genetic length of 167-193 centimorgans based on a linkage map using 344 markers, and a physical size of 95-140 megabases estimated by flow cytometry. Mapping the sex determining locus shows that females are the heterogametic sex, unlike most other Chironomidae. We identified two QTL each for lunar emergence time and diurnal emergence time. The distribution of QTL confirms a previously hypothesized genetic basis to a correlation of lunar and diurnal emergence times in natural populations. Mapping of clock genes and light receptors identified ciliary opsin 2 (cOps2) as a candidate to be involved in both lunar and diurnal timing; cryptochrome 1 (cry1) as a candidate gene for lunar timing; and two timeless (tim2, tim3) genes as candidate genes for diurnal timing. This QTL analysis of lunar rhythmicity, the first in any species, provides a unique entree into the molecular analysis of the lunar clock.

  18. Diurnal global variability of the Earth's magnetic field during geomagnetically quiet conditions

    Science.gov (United States)

    Klausner, V.

    2012-12-01

    This work proposes a methodology (or treatment) to establish a representative signal of the global magnetic diurnal variation. It is based on a spatial distribution in both longitude and latitude of a set of magnetic stations as well as their magnetic behavior on a time basis. We apply the Principal Component Analysis (PCA) technique using gapped wavelet transform and wavelet correlation. This new approach was used to describe the characteristics of the magnetic variations at Vassouras (Brazil) and 12 other magnetic stations spread around the terrestrial globe. Using magnetograms from 2007, we have investigated the global dominant pattern of the Sq variation as a function of low solar activity. This year was divided into two seasons for seasonal variation analysis: solstices (June and December) and equinoxes (March and September). We aim to reconstruct the original geomagnetic data series of the H component taking into account only the diurnal variations with periods of 24 hours on geomagnetically quiet days. We advance a proposal to reconstruct the Sq baseline using only the PCA first mode. The first interpretation of the results suggests that PCA/wavelet method could be used to the reconstruction of the Sq baseline.

  19. Mechanisms of diurnal precipitation over the US Great Plains: a cloud resolving model perspective

    Science.gov (United States)

    Lee, Myong-In; Choi, Ildae; Tao, Wei-Kuo; Schubert, Siegfried D.; Kang, In-Sik

    2010-02-01

    The mechanisms of summertime diurnal precipitation in the US Great Plains were examined with the two-dimensional (2D) Goddard Cumulus Ensemble (GCE) cloud-resolving model (CRM). The model was constrained by the observed large-scale background state and surface flux derived from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program’s Intensive Observing Period (IOP) data at the Southern Great Plains (SGP). The model, when continuously-forced by realistic surface flux and large-scale advection, simulates reasonably well the temporal evolution of the observed rainfall episodes, particularly for the strongly forced precipitation events. However, the model exhibits a deficiency for the weakly forced events driven by diurnal convection. Additional tests were run with the GCE model in order to discriminate between the mechanisms that determine daytime and nighttime convection. In these tests, the model was constrained with the same repeating diurnal variation in the large-scale advection and/or surface flux. The results indicate that it is primarily the surface heat and moisture flux that is responsible for the development of deep convection in the afternoon, whereas the large-scale upward motion and associated moisture advection play an important role in preconditioning nocturnal convection. In the nighttime, high clouds are continuously built up through their interaction and feedback with long-wave radiation, eventually initiating deep convection from the boundary layer. Without these upper-level destabilization processes, the model tends to produce only daytime convection in response to boundary layer heating. This study suggests that the correct simulation of the diurnal variation in precipitation requires that the free-atmospheric destabilization mechanisms resolved in the CRM simulation must be adequately parameterized in current general circulation models (GCMs) many of which are overly sensitive to the parameterized boundary layer

  20. Mechanisms of Diurnal Precipitation over the United States Great Plains: A Cloud-Resolving Model Simulation

    Science.gov (United States)

    Lee, M.-I.; Choi, I.; Tao, W.-K.; Schubert, S. D.; Kang, I.-K.

    2010-01-01

    The mechanisms of summertime diurnal precipitation in the US Great Plains were examined with the two-dimensional (2D) Goddard Cumulus Ensemble (GCE) cloud-resolving model (CRM). The model was constrained by the observed large-scale background state and surface flux derived from the Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Program s Intensive Observing Period (IOP) data at the Southern Great Plains (SGP). The model, when continuously-forced by realistic surface flux and large-scale advection, simulates reasonably well the temporal evolution of the observed rainfall episodes, particularly for the strongly forced precipitation events. However, the model exhibits a deficiency for the weakly forced events driven by diurnal convection. Additional tests were run with the GCE model in order to discriminate between the mechanisms that determine daytime and nighttime convection. In these tests, the model was constrained with the same repeating diurnal variation in the large-scale advection and/or surface flux. The results indicate that it is primarily the surface heat and moisture flux that is responsible for the development of deep convection in the afternoon, whereas the large-scale upward motion and associated moisture advection play an important role in preconditioning nocturnal convection. In the nighttime, high clouds are continuously built up through their interaction and feedback with long-wave radiation, eventually initiating deep convection from the boundary layer. Without these upper-level destabilization processes, the model tends to produce only daytime convection in response to boundary layer heating. This study suggests that the correct simulation of the diurnal variation in precipitation requires that the free-atmospheric destabilization mechanisms resolved in the CRM simulation must be adequately parameterized in current general circulation models (GCMs) many of which are overly sensitive to the parameterized boundary layer heating.

  1. Variation in ebmental quantification by X-ray fluorescence analysis in crystalline materials when applying pressure in sample preparation

    International Nuclear Information System (INIS)

    Macias B, L.R.; Garcia C, R.M.; De Ita de la Torre, A.; Chavez R, A.

    2000-01-01

    In this work making use of the diffraction and fluorescence techniques its were determined the presence of elements in a known compound ZrSiO 4 under different pressure conditions. At preparing the samples it were applied different pressures from 1600 until 350 k N/m 2 and it is detected the apparent variations in concentration in the Zr and Si elements. (Author)

  2. Characteristics of diurnal pattern of global photosynthetically-active ...

    African Journals Online (AJOL)

    A two year data (September 1992 August 1994) on photosynhetically-active radiation (PAR) measured at Ilorin (Lat.: 832´N. Long.:434´E) using LI-190SA quantum sensor are analysed both on daily and monthly mean diurnal bases. This was done with the aim of characterizing the diurnal pattern of this radiation at this ...

  3. Constrained Total Generalized p-Variation Minimization for Few-View X-Ray Computed Tomography Image Reconstruction.

    Science.gov (United States)

    Zhang, Hanming; Wang, Linyuan; Yan, Bin; Li, Lei; Cai, Ailong; Hu, Guoen

    2016-01-01

    Total generalized variation (TGV)-based computed tomography (CT) image reconstruction, which utilizes high-order image derivatives, is superior to total variation-based methods in terms of the preservation of edge information and the suppression of unfavorable staircase effects. However, conventional TGV regularization employs l1-based form, which is not the most direct method for maximizing sparsity prior. In this study, we propose a total generalized p-variation (TGpV) regularization model to improve the sparsity exploitation of TGV and offer efficient solutions to few-view CT image reconstruction problems. To solve the nonconvex optimization problem of the TGpV minimization model, we then present an efficient iterative algorithm based on the alternating minimization of augmented Lagrangian function. All of the resulting subproblems decoupled by variable splitting admit explicit solutions by applying alternating minimization method and generalized p-shrinkage mapping. In addition, approximate solutions that can be easily performed and quickly calculated through fast Fourier transform are derived using the proximal point method to reduce the cost of inner subproblems. The accuracy and efficiency of the simulated and real data are qualitatively and quantitatively evaluated to validate the efficiency and feasibility of the proposed method. Overall, the proposed method exhibits reasonable performance and outperforms the original TGV-based method when applied to few-view problems.

  4. Variations in depth-dose data between open and wedge fields for 4-MV x-rays

    International Nuclear Information System (INIS)

    Sewchand, W.; Khan, F.M.; Williamson, J.

    1978-01-01

    Central-axis depth-dose data for 4-MV x rays, including tissue-maximum ratios, were measured for wedge fields. Comparison with corresponding open-field data revealed differences in magnitude which increased with depth, field size, and wedge thickness. However, phantom scatter correction factors for the wedge fields differed less than 1% from corresponding open-field factors. The differences in central-axis percent depth doses between the two types of fields indicate beam hardening by the wedge filter. This study also implies that the derivation of tissue-maximum ratios from central-axis percent depth is as valid for wedge as for open fields

  5. Diural TSH variations in hypothyroidism.

    Science.gov (United States)

    Weeke, J; Laurberg, P

    1976-07-01

    There is a circadian variation in serum TSH in euthyroid subjects. A similar diurnal variation has been demonstrated in patients with hypothyroidism. In the present study the 24-hour pattern of serum TSH was investigated in eight patients with hypothyroidism of varying severity and in five hypothyroid patients treated with thyroxine (T4). There was a circadian variation in serum TSH in patients with hypothyroidism of moderate degree, and in patients treated for severe hypothyrodism with thyroxine. The pattern was similar to that found in normal subjects, i.e., low TSH levels in the daytime and higher levels at night. In severely hypothyroid patients, no diurnal variation in serum TSH was observed. A practical consequence is that blood samples for TSH measurements in patients with moderately elevated TSH levels are best taken after 1100 h, when the low day levels are reached.

  6. Measurement of Gamma-ray Energy Spectrum According to Temperature Variation Using a Fiber-Optic Radiation Sensor Based on YSO:Ce Crystal

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, H.; Yoo, W. J.; Shin, S. H.; Jang, J. S.; Kim, J. S.; Kwon, G.; Lee, D. E.; Jang, K. W.; Lee, B. [BK21 Plus Research Institute of Biomedical Engineering, Konkuk University, Chungju (Korea, Republic of)

    2015-05-15

    As an alternative to conventional radiation detectors, various fiber-optic radiation sensors (FORSs) have been investigated for gamma-ray monitoring because of their various desirable advantages, such as their small sensing volume, substantial flexibility, remote operation, ability to make real-time measurement, and immunity to high electromagnetic interference. In general, the basic principle of a radiation detection using scintillators is to measure the scintillating light signals generated from the interactions between the scintillators and the radiations. To measure gamma-ray, the inorganic scintillators used in the FORS should have some properties, such as high atomic material, high light yields, fast decay time, high density, and high stopping power. For these reasons, a cerium-doped lutetium yttrium orthosilicate (LYSO:Ce) crystal has been introduced as a promising scintillator in various radiation sensor applications. According to the recent studies, however, LYSO:Ce crystal is impossible to be applied in high-temperature conditions because it serves the fluctuations of its light yields with the temperature variation (i.e., thermosluminescence). In this study, to obtain gamma-ray energy spectra by measuring scintillating light signals emitted from the scintillators in high-temperature conditions, we first fabricated an FORS system using various inorganic scintillator crystals and then evaluated the light yields of each inorganic scintillator. As a promising scintillator for use in high-temperature conditions, a cerium-doped yttrium orthosilicate (YSO:Ce) crystal was selected and evaluated its thermal property according to the elevated temperature up to 300 .deg. C. We fabricated an FORS using inorganic scintillator and an optical fiber bundle. To select an adequate scintillator to apply in high-temperature conditions, the gamma-ray energy spectra were obtained by using four kinds of inorganic scintillators. From the experimental results, we selected YSO

  7. Evaluation of Effect of Gamma Rays Irradiation for Increasing of Variation in Germination and Agronomic Traits in Oilseed rape (Brassica napus L.

    Directory of Open Access Journals (Sweden)

    R. Momeni

    2012-04-01

    Full Text Available Increasing of genetic diversity is one of primary and basic goals of plant breeding programs. Induction of mutation is a method to increase genetic diversity that can be used in accommodate with selection, recombination and or combination of them in plant breeding. The aim of this study was to investigate the impact of different doses of gamma rays (500, 700, 900, 1100 and 1300 Gry on primary growth characters, such as: rate and percentage of germination, the length of rootlet and stemlet in M1 generation, and on agronomic characters such as: plant height, number of lateral branches, number of pods on main and lateral stem, length of pods and weigth of 1000-seed in M2 generation for two varieties of oilseed rape (Brassica napus, PF and Zarfam. Results of lab experiments showed that for both varieties, the germination percentage, the length of rootlet and the length of stemlet were significantly decreased by mutagen in compare with the control. While germination rate was only significantly affected by mutagen in PF. The estimation of "F" showed that there was significant difference between the variance of treatments for the germination rate and germination percentage in PF cultivar and for germination rate and stemlet length in Zarfam cultivar. In fact, increasing of gamma doses causes considerable enhancement in variance of treatment in compare with the control. The maximum relative coefficient of variation was related to 1300 Gry for germination rate of PF. In M2, all traits of study except number of pods on main stem was decreased by different doses of Gamma rays in PF cultivar. In opposition to other traits, Pods on main stem in PF cultivar was increased in different doses of gamma ray in compare with the control. But in Zarfam cultivar, only 1000-seed weight was significantly affected by Gamma rays.

  8. Diurnal and semi-diurnal tidal structures due to O2, O3 and H2O ...

    Indian Academy of Sciences (India)

    from World Meteorological Organization (WMO. 1986), while the Rayleigh scattering cross section was calculated using the formula of Nicolet (1984). ..... Figure 5(a) exhibits the exponential growth of diurnal amplitude with altitude, at low to mid lat- itudes. At high latitudes, the diurnal amplitude decreases with altitude due to ...

  9. Correlations between variations in solar EUV and soft X-ray irradiance and photoelectron energy spectra observed on Mars and Earth

    Science.gov (United States)

    Peterson, W. K.; Brain, D. A.; Mitchell, D. L.; Bailey, S. M.; Chamberlin, P. C.

    2013-11-01

    extreme ultraviolet (EUV; 10-120 nm) and soft X-ray (XUV; 0-10 nm) radiation are major heat sources for the Mars thermosphere as well as the primary source of ionization that creates the ionosphere. In investigations of Mars thermospheric chemistry and dynamics, solar irradiance models are used to account for variations in this radiation. Because of limited proxies, irradiance models do a poor job of tracking the significant variations in irradiance intensity in the EUV and XUV ranges over solar rotation time scales when the Mars-Sun-Earth angle is large. Recent results from Earth observations show that variations in photoelectron energy spectra are useful monitors of EUV and XUV irradiance variability. Here we investigate photoelectron energy spectra observed by the Mars Global Surveyor (MGS) Electron Reflectometer (ER) and the FAST satellite during the interval in 2005 when Earth, Mars, and the Sun were aligned. The Earth photoelectron data in selected bands correlate well with calculations based on 1 nm resolution observations above 27 nm supplemented by broadband observations and a solar model in the 0-27 nm range. At Mars, we find that instrumental and orbital limitations to the identifications of photoelectron energy spectra in MGS/ER data preclude their use as a monitor of solar EUV and XUV variability. However, observations with higher temporal and energy resolution obtained at lower altitudes on Mars might allow the separation of the solar wind and ionospheric components of electron energy spectra so that they could be used as reliable monitors of variations in solar EUV and XUV irradiance than the time shifted, Earth-based, F10.7 index currently used.

  10. Correlations Between Variations in Solar EUV and Soft X-Ray Irradiance and Photoelectron Energy Spectra Observed on Mars and Earth

    Science.gov (United States)

    Peterson, W. K.; Brain, D. A.; Mitchell, D. L.; Bailey, S. M.; Chamberlin, P. C.

    2013-01-01

    Solar extreme ultraviolet (EUV; 10-120 nm) and soft X-ray (XUV; 0-10 nm) radiation are major heat sources for the Mars thermosphere as well as the primary source of ionization that creates the ionosphere. In investigations of Mars thermospheric chemistry and dynamics, solar irradiance models are used to account for variations in this radiation. Because of limited proxies, irradiance models do a poor job of tracking the significant variations in irradiance intensity in the EUV and XUV ranges over solar rotation time scales when the Mars-Sun-Earth angle is large. Recent results from Earth observations show that variations in photoelectron energy spectra are useful monitors of EUV and XUV irradiance variability. Here we investigate photoelectron energy spectra observed by the Mars Global Surveyor (MGS) Electron Reflectometer (ER) and the FAST satellite during the interval in 2005 when Earth, Mars, and the Sun were aligned. The Earth photoelectron data in selected bands correlate well with calculations based on 1 nm resolution observations above 27 nm supplemented by broadband observations and a solar model in the 0-27 nm range. At Mars, we find that instrumental and orbital limitations to the identifications of photoelectron energy spectra in MGS/ER data preclude their use as a monitor of solar EUV and XUV variability. However, observations with higher temporal and energy resolution obtained at lower altitudes on Mars might allow the separation of the solar wind and ionospheric components of electron energy spectra so that they could be used as reliable monitors of variations in solar EUV and XUV irradiance than the time shifted, Earth-based, F(10.7) index currently used.

  11. Impact of resolving the diurnal cycle in an ocean-atmosphere GCM. Pt. 1: a diurnally forced OGCM

    Energy Technology Data Exchange (ETDEWEB)

    Bernie, D.J. [University of Reading, National Centre for Atmospheric Science - Climate, Department of Meteorology, Reading (United Kingdom); Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, IPSL, Paris (France); Met Office Hadley Centre, Exeter, EX1 3PB (United Kingdom); Guilyardi, E. [University of Reading, National Centre for Atmospheric Science - Climate, Department of Meteorology, Reading (United Kingdom); Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, IPSL, Paris (France); Madec, G. [Laboratoire d' Oceanographie et du Climat, Experimentation et Approches Numeriques, IPSL, Paris (France); Slingo, J.M.; Woolnough, S.J. [University of Reading, National Centre for Atmospheric Science - Climate, Department of Meteorology, Reading (United Kingdom)

    2007-11-15

    The diurnal cycle is a fundamental time scale in the climate system, at which the upper ocean and atmosphere are routinely observed to vary. Current climate models, however, are not configured to resolve the diurnal cycle in the upper ocean or the interaction of the ocean and atmosphere on these time scales. This study examines the diurnal cycle of the tropical upper ocean and its climate impacts. In the present paper, the first of two, a high vertical resolution ocean general circulation model (OGCM), with modified physics, is developed which is able to resolve the diurnal cycle of sea surface temperature (SST) and current variability in the upper ocean. It is then validated against a satellite derived parameterization of diurnal SST variability and in-situ current observations. The model is then used to assess rectification of the intraseasonal SST response to the Madden-Julian oscillation (MJO) by the diurnal cycle of SST. Across the equatorial Indo-Pacific it is found that the diurnal cycle increases the intraseasonal SST response to the MJO by around 20%. In the Pacific, the diurnal cycle also modifies the exchange of momentum between equatorially divergent Ekman currents and the meridionally convergent geostrophic currents beneath, resulting in a 10% increase in the strength of the Ekman cells and equatorial upwelling. How the thermodynamic and dynamical impacts of the diurnal cycle effect the mean state, and variability, of the climate system cannot be fully investigated in the constrained design of ocean-only experiments presented here. The second part of this study, published separately, addresses the climate impacts of the diurnal cycle in the coupled system by coupling the OGCM developed here to an atmosphere general circulation model. (orig.)

  12. An Improved Simulation of the Diurnally Varying Street Canyon Flow

    Science.gov (United States)

    Yaghoobian, Neda; Kleissl, Jan; Paw U, Kyaw Tha

    2012-11-01

    The impact of diurnal variation of temperature distribution over building and ground surfaces on the wind flow and scalar transport in street canyons is numerically investigated using the PArallelized LES Model (PALM). The Temperature of Urban Facets Indoor-Outdoor Building Energy Simulator (TUF-IOBES) is used for predicting urban surface heat fluxes as boundary conditions for a modified version of PALM. TUF-IOBES dynamically simulates indoor and outdoor building surface temperatures and heat fluxes in an urban area taking into account weather conditions, indoor heat sources, building and urban material properties, composition of the building envelope (e.g. windows, insulation), and HVAC equipment. Temperature (and heat flux) distribution over urban surfaces of the 3-D raster-type geometry of TUF-IOBES makes it possible to provide realistic, high resolution boundary conditions for the numerical simulation of flow and scalar transport in an urban canopy. Compared to some previous analyses using uniformly distributed thermal forcing associated with urban surfaces, the present analysis shows that resolving non-uniform thermal forcings can provide more detailed and realistic patterns of the local air flow and pollutant dispersion in urban canyons.

  13. An explanation for the different climate sensitivities of land and ocean surfaces based on the diurnal cycle

    Directory of Open Access Journals (Sweden)

    A. Kleidon

    2017-09-01

    Full Text Available Observations and climate model simulations consistently show a higher climate sensitivity of land surfaces compared to ocean surfaces. Here we show that this difference in temperature sensitivity can be explained by the different means by which the diurnal variation in solar radiation is buffered. While ocean surfaces buffer the diurnal variations by heat storage changes below the surface, land surfaces buffer it mostly by heat storage changes above the surface in the lower atmosphere that are reflected in the diurnal growth of a convective boundary layer. Storage changes below the surface allow the ocean surface–atmosphere system to maintain turbulent fluxes over day and night, while the land surface–atmosphere system maintains turbulent fluxes only during the daytime hours, when the surface is heated by absorption of solar radiation. This shorter duration of turbulent fluxes on land results in a greater sensitivity of the land surface–atmosphere system to changes in the greenhouse forcing because nighttime temperatures are shaped by radiative exchange only, which are more sensitive to changes in greenhouse forcing. We use a simple, analytic energy balance model of the surface–atmosphere system in which turbulent fluxes are constrained by the maximum power limit to estimate the effects of these different means to buffer the diurnal cycle on the resulting temperature sensitivities. The model predicts that land surfaces have a 50 % greater climate sensitivity than ocean surfaces, and that the nighttime temperatures on land increase about twice as much as daytime temperatures because of the absence of turbulent fluxes at night. Both predictions compare very well with observations and CMIP5 climate model simulations. Hence, the greater climate sensitivity of land surfaces can be explained by its buffering of diurnal variations in solar radiation in the lower atmosphere.

  14. 14C concentrations in the old woods at 6000yrBP and the variations of cosmic rays

    International Nuclear Information System (INIS)

    Sato, Taiichi; Sakurai, Hirohisa; Tokanai, Huyuki

    2008-01-01

    A large quantity of old woods was recently excavated with the Chuetsu-oki Earthquake in the bottom of the sea of near the Izumozaki-oki Nigata Prefecture. First of all, we have measured the radiocarbon ages for the three samples to identify the calendar ages of the woods. The radiocarbon ages were 5357±45 yrBP, 4573±52 yrBP, and 4812±52 yrBP, respectively. Using the OXCAL program, the calendar ages were calculated in the range from 6300 yrBP to 5100 yrBP. The IntCal04 data shows that the 14 C concentrations with the era are very variable with 20 per mille variations. We show a plan to investigate 14 C concentrations of the old tree rings around 6000 yrBP. (author)

  15. Viscosity changes of riparian water controls diurnal fluctuations of stream-flow and DOC concentration

    Science.gov (United States)

    Schwab, Michael; Klaus, Julian; Pfister, Laurent; Weiler, Markus

    2015-04-01

    Diurnal fluctuations in stream-flow are commonly explained as being triggered by the daily evapotranspiration cycle in the riparian zone, leading to stream flow minima in the afternoon. While this trigger effect must necessarily be constrained by the extent of the growing season of vegetation, we here show evidence of daily stream flow maxima in the afternoon in a small headwater stream during the dormant season. We hypothesize that the afternoon maxima in stream flow are induced by viscosity changes of riparian water that is caused by diurnal temperature variations of the near surface groundwater in the riparian zone. The patterns were observed in the Weierbach headwater catchment in Luxembourg. The catchment is covering an area of 0.45 km2, is entirely covered by forest and is dominated by a schistous substratum. DOC concentration at the outlet of the catchment was measured with the field deployable UV-Vis spectrometer spectro::lyser (scan Messtechnik GmbH) with a high frequency of 15 minutes over several months. Discharge was measured with an ISCO 4120 Flow Logger. During the growing season, stream flow shows a frequently observed diurnal pattern with discharge minima in the afternoon. During the dormant season, a long dry period with daily air temperature amplitudes of around 10 ° C occurred in March and April 2014, with discharge maxima in the afternoon. The daily air temperature amplitude led to diurnal variations in the water temperature of the upper 10 cm of the riparian zone. Higher riparian water temperatures cause a decrease in water viscosity and according to the Hagen-Poiseuille equation, the volumetric flow rate is inversely proportional to viscosity. Based on the Hagen-Poiseuille equation and the viscosity changes of water, we calculated higher flow rates of near surface groundwater through the riparian zone into the stream in the afternoon which explains the stream flow maxima in the afternoon. With the start of the growing season, the viscosity

  16. Diurnal changes in ocean color sensed in satellite imagery

    Science.gov (United States)

    Arnone, Robert; Vandermuelen, Ryan; Soto, Inia; Ladner, Sherwin; Ondrusek, Michael; Yang, Haoping

    2017-07-01

    Measurements of diurnal changes in ocean color in turbid coastal regions in the Gulf of Mexico were characterized using above water spectral radiometry from a National Aeronautics and Space Administration (aerosol robotic network-WaveCIS CSI-06) site that can provide 8 to 10 observations per day. Satellite capability to detect diurnal changes in ocean color was characterized using hourly overlapping afternoon orbits of the visual infrared imaging radiometer suite (VIIRS) Suomi National Polar-orbiting Partnership ocean color sensor and validated with in situ observations. The monthly cycle of diurnal changes was investigated for different water masses using VIIRS overlaps. Results showed the capability of satellite observations to monitor hourly color changes in coastal regions that can be impacted by vertical movement of optical layers, in response to tides, resuspension, and river plume dispersion. The spatial variability of VIIRS diurnal changes showed the occurrence and displacement of phytoplankton blooming and decaying processes. The diurnal change in ocean color was above 20%, which represents a 30% change in chlorophyll-a. Seasonal changes in diurnal ocean color for different water masses suggest differences in summer and winter responses to surface processes. The diurnal changes observed using satellite ocean color can be used to define the following: surface processes associated with biological activity, vertical changes in optical depth, and advection of water masses.

  17. Summary of daily observational results of solar phenomena, cosmic ray, geomagnetic variation, ionosphere, radio wave propagation and airglow. During October 1973 through September 1975

    Energy Technology Data Exchange (ETDEWEB)

    1976-12-01

    The diagrams in this section of the publication illustrate the summary of daily observational results of solar phenomena, cosmic ray, geomagnetic variation, ionosphere, radio wave propagation and airglow observed in Japan. For convenience, the observational results are arranged by the solar rotation number. The aim of this illustration is to disseminate an outline of daily events observed in Japan for the benefit of active research workers who plan to make detailed study of the specific solar and terrestrial events. Therefore, the illustrations do not show all observational results in Japan but only representative ones at some key stations in Japan. They will suffice for the present purpose. The method of illustration shown in the instruction on the next page is still a preliminary one, and it is subject to change resulting from the kind advice of the users of this part of the publication.

  18. Pulse periods and the long-term variations of the X-ray pulsars VELA X-1 and Centaurus X-3

    Science.gov (United States)

    Tsunemi, Hiroshi

    The paper reports recent determinations of the pulse period for two X-ray pulsars, Vela X-1 and Cen X-3, made in 1987 with the All Sky Monitor (ASM) on board the Ginga satellite. The heliocentric pulse periods are 283.09 + or - 0.01 s and 4.8229 + or - 0.0001 s, respectively. These are the longest and shortest values in their respective observational histories. The random walk model for the Vela X-1 pulsar can explain this result as well as those obtained previously. It is also noted that the pulse-period change for the Cen X-3 system shows a 9-yr periodicity. This is probably due to the activity of the companion star rather than to Doppler-shift variations due to a third body or the precession of the neutron star.

  19. Accelerating an Ordered-Subset Low-Dose X-Ray Cone Beam Computed Tomography Image Reconstruction with a Power Factor and Total Variation Minimization.

    Science.gov (United States)

    Huang, Hsuan-Ming; Hsiao, Ing-Tsung

    2016-01-01

    In recent years, there has been increased interest in low-dose X-ray cone beam computed tomography (CBCT) in many fields, including dentistry, guided radiotherapy and small animal imaging. Despite reducing the radiation dose, low-dose CBCT has not gained widespread acceptance in routine clinical practice. In addition to performing more evaluation studies, developing a fast and high-quality reconstruction algorithm is required. In this work, we propose an iterative reconstruction method that accelerates ordered-subsets (OS) reconstruction using a power factor. Furthermore, we combine it with the total-variation (TV) minimization method. Both simulation and phantom studies were conducted to evaluate the performance of the proposed method. Results show that the proposed method can accelerate conventional OS methods, greatly increase the convergence speed in early iterations. Moreover, applying the TV minimization to the power acceleration scheme can further improve the image quality while preserving the fast convergence rate.

  20. Diurnal cycling of urban aerosols under different weather regimes

    Science.gov (United States)

    Gregorič, Asta; Drinovec, Luka; Močnik, Griša; Remškar, Maja; Vaupotič, Janja; Stanič, Samo

    2016-04-01

    A one month measurement campaign was performed in summer 2014 in Ljubljana, the capital of Slovenia (population 280,000), aiming to study temporal and spatial distribution of urban aerosols and the mixing state of primary and secondary aerosols. Two background locations were chosen for this purpose, the first one in the city center (urban background - KIS) and the second one in the suburban background (Brezovica). Simultaneous measurements of black carbon (BC) and particle number size distribution of submicron aerosols (PM1) were conducted at both locations. In the summer season emission from traffic related sources is expected to be the main local contribution to BC concentration. Concentrations of aerosol species and gaseous pollutants within the planetary boundary layer are controlled by the balance between emission sources of primary aerosols and gases, production of secondary aerosols, chemical reactions of precursor gases under solar radiation and the rate of dilution by mixing within the planetary boundary layer (PBL) as well as with tropospheric air. Only local emission sources contribute to BC concentration during the stable PBL with low mixing layer height, whereas during the time of fully mixed PBL, regionally transported BC and other aerosols can contribute to the surface measurements. The study describes the diurnal behaviour of the submicron aerosol at the urban and suburban background location under different weather regimes. Particles in three size modes - nucleation (humidity, wind speed and direction), diurnal profile differs for sunny, cloudy and rainy days. Nucleation mode particles were found to be subjected to lower daily variation and only slightly influenced by weather, as opposed to Aitken and accumulation mode particles. The highest correlation between BC and particle number concentration is observed during stable atmospheric conditions in the night and morning hours and is attributed to different particle size modes, depending on the

  1. Diurnal Cycle of Clouds and Precipitation at the ARM SGP Site

    Science.gov (United States)

    Zhao, W.; Marchand, R.; Fu, Q.

    2016-12-01

    Millimeter Wavelength Cloud Radar (MMCR) data from Dec. 1996 to Dec. 2010, collected at the U. S. Department of Energy Atmospheric Radiation Measurement (ARM) program site in the U.S. Southern Great Plains (SGP), are categorized into clouds (-40dBZe≤reflectivityCRM). Observational and simulated radar reflectivity are compared and further sorted into different atmospheric states identified by Evans (2014). Evans used a neutral network to take ERA-Interim state variables (i.e. horizontal winds, relative humidity, temperature at seven predetermined pressure level and surface pressure) on an 8×8 grid with 1.5º×1.5º spatial resolution centered on the SGP site and found twenty-one atmospheric states which represent specific synoptic conditions. We use these states to study the differences in the diurnal cycle between observations and simulations. Differences in the (mean) annual diurnal cycle between the observations and model are decomposed into errors in the daily mean, errors in the diurnal variation in each state, and errors due to difference in the frequency of occurrence of atmospheric states between ERA and the MMF. The magnitude of various error sources is assessed.

  2. Diurnal and seasonal DOC and POC variability in the land-locked sea

    Directory of Open Access Journals (Sweden)

    Beata Szymczycha

    2017-07-01

    Full Text Available Organic matter is a minor yet important component of the marine environment. The aim of this study was to investigate the diurnal and seasonal changes in dissolved and particulate organic carbon (DOC and POC, respectively. Thus, DOC and POC as well as chlorophyll a (Chl a, δ13C, NO3−, NO2−, NH4+, PO43−, salinity, pH, and temperature were regularly measured in samples collected for 24 h (2-h resolution in the Gdańsk Deep (54°44.730′N, 19°08.531′E at three water depths (1, 10, and 40 m during sampling campaigns in 2011 (May, 2014 (May, and 2015 (January, March, May, July, September, November. Seasonal variations in DOC and POC followed the seasonality of Chl a (proportional trend and nutrients (reverse trend concentrations. Diurnal oscillations were detected in six out of the eight measurement series. The strongest diurnal variability in both POC and DOC occurred in May 2011 and March 2015, when phytoplankton activity was highest (high Chl a. The surprisingly low δ13C values (range: −28‰ to −24‰ measured over the course of the study revealed the gaps in our knowledge of the isotopic characteristics of terrestrial- vs. marine-derived particulate organic matter.

  3. Quantifying Diurnal Cloud Radiative Effects by Cloud Type in the Tropical Western Pacific

    Energy Technology Data Exchange (ETDEWEB)

    Burleyson, Casey D.; Long, Charles N.; Comstock, Jennifer M.

    2015-06-01

    Cloud radiative effects are examined using long-term datasets collected at the three Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facilities in the tropical western Pacific. We quantify the surface radiation budget, cloud populations, and cloud radiative effects by partitioning the data by cloud type, time of day, and as a function of large scale modes of variability such as El Niño Southern Oscillation (ENSO) phase and wet/dry seasons at Darwin. The novel facet of our analysis is that we break aggregate cloud radiative effects down by cloud type across the diurnal cycle. The Nauru cloud populations and subsequently the surface radiation budget are strongly impacted by ENSO variability whereas the cloud populations over Manus only shift slightly in response to changes in ENSO phase. The Darwin site exhibits large seasonal monsoon related variations. We show that while deeper convective clouds have a strong conditional influence on the radiation reaching the surface, their limited frequency reduces their aggregate radiative impact. The largest source of shortwave cloud radiative effects at all three sites comes from low clouds. We use the observations to demonstrate that potential model biases in the amplitude of the diurnal cycle and mean cloud frequency would lead to larger errors in the surface energy budget compared to biases in the timing of the diurnal cycle of cloud frequency. Our results provide solid benchmarks to evaluate model simulations of cloud radiative effects in the tropics.

  4. Analysis of the variation of the attenuation curve in function of the radiation field size for k Vp X-ray beams using the MCNP-5C code

    Energy Technology Data Exchange (ETDEWEB)

    Fernandes, Marco A.R., E-mail: marco@cetea.com.b, E-mail: marfernandes@fmb.unesp.b [Universidade Estadual Paulista Julio de Mesquita Filho (FMB/UNESP), Botucatu, SP (Brazil). Fac. de Medicina; Ribeiro, Victor A.B. [Universidade Estadual Paulista Julio de Mesquita Filho (IBB/UNESP), Botucatu, SP (Brazil). Inst. de Biociencias; Viana, Rodrigo S.S.; Coelho, Talita S. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    The paper illustrates the use of the Monte Carlo method, MCNP-5C code, to analyze the attenuation curve behavior of the 50 kVp radiation beam from superficial radiotherapy equipment as Dermopan2 model. The simulations seek to verify the MCNP-5C code performance to study the variation of the attenuation curve - percentage depth dose (PDD) curve - in function of the radiation field dimension used at radiotherapy of skin tumors with 50 kVp X-ray beams. The PDD curve was calculated for six different radiation field sizes with circular geometry of 1.0, 2.0, 3.0, 4.0, 5.0 and 6.0 cm in diameter. The radiation source was modeled considering a tungsten target with inclination 30 deg, focal point of 6.5 mm in diameter and energy beam of 50 kVp; the X-ray spectrum was calculated with the MCNP-5C code adopting total filtration (beryllium window of 1 mm and aluminum additional filter of 1 mm). The PDD showed decreasing behavior with the attenuation depth similar what is presented on the literature. There was not significant variation at the PDD values for the radiation field between 1.0 and 4.0 cm in diameter. The differences increased for fields of 5.0 and 6.0 cm and at attenuation depth higher than 1.0 cm. When it is compared the PDD values for fields of 3.0 and 6.0 cm in diameter, it verifies the greater difference (12.6 %) at depth of 5.7 cm, proving the scattered radiation effect. The MCNP-5C code showed as an appropriate procedure to analyze the attenuation curves of the superficial radiotherapy beams. (author)

  5. Multi-year X-Ray Variations of Iron-K and Continuum Emissions in the Young Supernova Remnant Cassiopeia A

    Energy Technology Data Exchange (ETDEWEB)

    Sato, Toshiki; Masai, Kuniaki [Department of Physics, Tokyo Metropolitan University, 1-1 Minami-Osawa, Hachioji, Tokyo 192-0397 (Japan); Maeda, Yoshitomo; Ishida, Manabu [Department of High Energy Astrophysics, Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), 3-1-1 Yoshinodai, Sagamihara, 229-8510 (Japan); Bamba, Aya [Department of Physics, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Katsuda, Satoru [Department of Physics, Faculty of Science and Engineering, Chuo University, 1-13-27 Kasuga, Bunkyo, Tokyo 112-8551 (Japan); Ohira, Yutaka; Yamazaki, Ryo; Sawada, Makoto [Department of Physics and Mathematics, Aoyama Gakuin University, 5-10-1 Fuchinobe, Chuo-ku, Sagamihara, Kanagawa 252-5258 (Japan); Matsumoto, Hironori [Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8602 (Japan); Terada, Yukikatsu [Graduate School of Science and Engineering, Saitama University, 255 Shimo-Ohkubo, Sakura, Saitama 338-8570 (Japan); Hughes, John P., E-mail: toshiki@astro.isas.jaxa.jp [Department of Physics and Astronomy, Rutgers University, 136 Frelinghuysen Road, Piscataway, NJ 08854-8019 (United States)

    2017-02-20

    We found a simultaneous decrease of the Fe–K line and 4.2–6 keV continuum of Cassiopeia A with the monitoring data taken by the Chandra X-ray Observatory in 2000–2013. The flux change rates in the whole remnant are −0.65 ± 0.02% yr{sup −1} in the 4.2–6.0 keV continuum and −0.6 ± 0.1% yr{sup −1} in the Fe–K line. In the eastern region where the thermal emission is considered to dominate, the variations show the largest values: −1.03 ± 0.05% yr{sup −1} (4.2–6 keV band) and −0.6 ± 0.1% yr{sup −1} (Fe–K line). In this region, the time evolution of the emission measure and the temperature have a decreasing trend. This could be interpreted as adiabatic cooling with the expansion of m = 0.66. On the other hand, in the non-thermal emission dominated regions, variations of the 4.2–6 keV continuum show smaller rates: −0.60 ± 0.04% yr{sup −1} in the southwestern region, −0.46 ± 0.05% yr{sup −1} in the inner region, and +0.00 ± 0.07% yr{sup −1} in the forward shock region. In particular, flux does not show significant change in the forward shock region. These results imply that strong braking in shock velocity has not been occurring in Cassiopeia A (<5 km s{sup −1} yr{sup −1}). All of our results support the idea that X-ray flux decay in the remnant is mainly caused by thermal components.

  6. Study of the high energy Cosmic Rays large scale anisotropies with the ANTARES neutrino telescope

    International Nuclear Information System (INIS)

    Illuminati, Giulia

    2016-01-01

    We present the analysis method used to search for an anisotropy in the high energy Cosmic Rays arrival distribution using data collected by the ANTARES telescope. ANTARES is a neutrino detector, where the collected data are dominated by a large background of cosmic ray muons. Therefore, the background data are suitable for high-statistics studies of cosmic rays in the Northern sky. The main challenge for this analysis is accounting for those effects which can mimic an apparent anisotropy in the muon arrival direction: the detector exposure asymmetries, non-uniform time coverage, diurnal and seasonal variation of the atmospheric temperature. Once all these effects have been corrected, a study of the anisotropy profiles along the right ascension can be performed. (paper)

  7. Simulated precipitation diurnal cycles over East Asia using different CAPE-based convective closure schemes in WRF model

    Science.gov (United States)

    Yang, Ben; Zhou, Yang; Zhang, Yaocun; Huang, Anning; Qian, Yun; Zhang, Lujun

    2018-03-01

    Closure assumption in convection parameterization is critical for reasonably modeling the precipitation diurnal variation in climate models. This study evaluates the precipitation diurnal cycles over East Asia during the summer of 2008 simulated with three convective available potential energy (CAPE) based closure assumptions, i.e. CAPE-relaxing (CR), quasi-equilibrium (QE), and free-troposphere QE (FTQE) and investigates the impacts of planetary boundary layer (PBL) mixing, advection, and radiation on the simulation by using the weather research and forecasting model. The sensitivity of precipitation diurnal cycle to PBL vertical resolution is also examined. Results show that the precipitation diurnal cycles simulated with different closures all exhibit large biases over land and the simulation with FTQE closure agrees best with observation. In the simulation with QE closure, the intensified PBL mixing after sunrise is responsible for the late-morning peak of convective precipitation, while in the simulation with FTQE closure, convective precipitation is mainly controlled by advection cooling. The relative contributions of different processes to precipitation formation are functions of rainfall intensity. In the simulation with CR closure, the dynamical equilibrium in the free troposphere still can be reached, implying the complex cause-effect relationship between atmospheric motion and convection. For simulations in which total CAPE is consumed for the closures, daytime precipitation decreases with increased PBL resolution because thinner model layer produces lower convection starting layer, leading to stronger downdraft cooling and CAPE consumption. The sensitivity of the diurnal peak time of precipitation to closure assumption can also be modulated by changes in PBL vertical resolution. The results of this study help us better understand the impacts of various processes on the precipitation diurnal cycle simulation.

  8. Application of GAMMA ray for induction of mutation and combination with biotechnology for induce desirable genetic variation in Tangerine

    International Nuclear Information System (INIS)

    Rahimi, M.; Majd, F.; Rastegari, J.; Vedadi, S.; Naseri, M.; Jahangirzadeh, E.

    2002-01-01

    Combined application of physical mutagen and tissue culture for induction of somatic mutation in some characters without affecting the whole genome proved to be an efficient tool for improvement of plant trees.Up to now substantial breeding research has not been done on fruit trees in Iran. We are intending to begin a new era in fruit trees improvement through mutation and biotechnology. On this basis we selected tangerine as a well-adapted and highly consumed citrus fruit which has a disadvantage of too many seeds in it's flesh. Through this technique the aim is to produce seedless/less seeded tangerine in order to motivate increase in cultivation area and potential for export. We used physical mutagen (γ-ray) with doses of (30,35 and 40 Gy) for lateral bud in vivo and doses of (10, 15 and 20 Gy) for bud in-vitro. To produce explant free of pathogen we used shoot tip grafting (stg) technique, and micropropagation of bud in modified MS medium for multiplication of buds

  9. Impacts of gate bias and its variation on gamma-ray irradiation resistance of SiC MOSFETs

    Energy Technology Data Exchange (ETDEWEB)

    Murata, Koichi; Mitomo, Satoshi; Matsuda, Takuma; Yokoseki, Takashi [Saitama University, Sakuraku (Japan); National Institutes for Quantum and Radiological Science and Technology (QST), Takasaki (Japan); Makino, Takahiro; Onoda, Shinobu; Takeyama, Akinori; Ohshima, Takeshi [National Institutes for Quantum and Radiological Science and Technology (QST), Takasaki (Japan); Okubo, Shuichi; Tanaka, Yuki; Kandori, Mikio; Yoshie, Toru [Sanken Electric Co., Ltd., Niiza, Saitama (Japan); Hijikata, Yasuto [Saitama University, Sakuraku (Japan)

    2017-04-15

    Gamma-ray irradiation into vertical type n-channel hexagonal (4H)-silicon carbide (SiC) metal-oxide-semiconductor field effect transistors (MOSFETs) was performed under various gate biases. The threshold voltage for the MOSFETs irradiated with a constant positive gate bias showed a large negative shift, and the shift slightly recovered above 100 kGy. For MOSFETs with non- and a negative constant biases, no significant change in threshold voltage, V{sub th}, was observed up to 400 kGy. By changing the gate bias from positive bias to either negative or non-bias, the V{sub th} significantly recovered from the large negative voltage shift induced by 50 kGy irradiation with positive gate bias after only 10 kGy irradiation with either negative or zero bias. It indicates that the positive charges generated in the gate oxide near the oxide-SiC interface due to irradiation were removed or recombined instantly by the irradiation under zero or negative biases. (copyright 2016 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  10. Bond length variation in Zn substituted NiO studied from extended X-ray absorption fine structure

    Science.gov (United States)

    Singh, S. D.; Poswal, A. K.; Kamal, C.; Rajput, Parasmani; Chakrabarti, Aparna; Jha, S. N.; Ganguli, Tapas

    2017-06-01

    Bond length behavior for Zn substituted NiO is determined through extended x-ray absorption fine structure (EXAFS) measurements performed at ambient conditions. We report bond length value of 2.11±0.01 Å for Zn-O of rock salt (RS) symmetry, when Zn is doped in RS NiO. Bond length for Zn substituted NiO RS ternary solid solutions shows relaxed behavior for Zn-O bond, while it shows un-relaxed behavior for Ni-O bond. These observations are further supported by first-principles calculations. It is also inferred that Zn sublattice remains nearly unchanged with increase in lattice parameter. On the other hand, Ni sublattice dilates for Zn compositions up to 20% to accommodate increase in the lattice parameter. However, for Zn compositions more than 20%, it does not further dilate. It has been attributed to the large disorder that is incorporated in the system at and beyond 20% of Zn incorporation in the cubic RS lattice of ternary solid solutions. For these large percentages of Zn incorporation, the Ni and the Zn atoms re-arrange themselves microscopically about the same nominal bond length rather than systematically increase in magnitude to minimize the energy of the system. This results in an increase in the Debye-Waller factor with increase in the Zn concentration rather than a systematic increase in the bond lengths.

  11. Evaluation of variations in absorbed dose and image noise according to patient forms in X-ray computed tomography

    International Nuclear Information System (INIS)

    Matsubara, Kosuke; Tsujii, Hideo; Yamamoto, Tomoyuki; Koshida, Kichiro; Suzuki, Masayuki; Hayakawa, Mayumi

    2005-01-01

    Excessive radiation exposure in pediatric computed tomography (CT) scanning has become a serious problem, and it is difficult to select scan parameters for the scanning of small patients such as children. We investigated differences in absorbed dose and standard deviation (SD) in Hounsfield unit (HU) caused by differences in the form of the subject using a body-type phantom with removable body parts. Using four X-ray CT scanners, measurements were made with values from 50 mAs to 300 mAs, with slices of 50 mAs, using scan protocols that were assumed to perform thorough examinations. The results showed that the mAs values and absorbed doses were almost proportional, and the absorbed doses in the phantom without body parts were about 1.1-2.2-fold higher than those of the phantom with body parts at the same points. The SD values obtained indicated that the absorbed doses in the phantom with body parts were 0.3-0.6 times those of the phantom without body parts when the mAs values used were adjusted so that both SD values were the same. The absorbed doses in various patient forms can be estimated from these results, and they will become critical data for the selection of appropriate scan protocols. (author)

  12. Evaluation of variations in absorbed dose and image noise according to patient forms in X-ray computed tomography.

    Science.gov (United States)

    Matsubara, Kosuke; Koshida, Kichiro; Suzuki, Masayuki; Hayakawa, Mayumi; Tsujii, Hideo; Yamamoto, Tomoyuki

    2005-12-20

    Excessive radiation exposure in pediatric computed tomography (CT) scanning has become a serious problem, and it is difficult to select scan parameters for the scanning of small patients such as children. We investigated differences in absorbed dose and standard deviation (SD) in Hounsfield unit (HU) caused by differences in the form of the subject using a body-type phantom with removable body parts. Using four X-ray CT scanners, measurements were made with values from 50 mAs to 300 mAs, with slices of 50 mAs, using scan protocols that were assumed to perform thorough examinations. The results showed that the mAs values and absorbed doses were almost proportional, and the absorbed doses in the phantom without body parts were about 1.1-2.2-fold higher than those of the phantom with body parts at the same points. The SD values obtained indicated that the absorbed doses in the phantom with body parts were 0.3-0.6 times those of the phantom without body parts when the mAs values used were adjusted so that both SD values were the same. The absorbed doses in various patient forms can be estimated from these results, and they will become critical data for the selection of appropriate scan protocols.

  13. Genetic variation for germination and physiological traits in sunflower mutants induced by gamma rays [Helianthus annuus L.

    International Nuclear Information System (INIS)

    Alejo-Jaimes, A.; Jardinaud, M.F.; Maury, P.; Alibert, G.; Gentzbittel, L.; Sarrafi, A.; Grieu, P.; Petiprez, M.

    2004-01-01

    Seeds of sunflower line AS-613 were irradiated with gamma rays and 1,559 M4 progenies were studied for their germination characteristics and the following traits were studied: thousand seed weight, seed size, time before emergence, percentage of emerged seedlings, hypocotyl length and diameter, number of cotyledons and cotyledons pigmentation intensity. A high genetic variability was observed for all the studied traits. Through M4 progenies, 9 mutants presenting the most differences with the original genotype (AS-613) were planted in a randomized blocks design with 8 replications in a controlled greenhouse and some morphological and physiological traits were studied, which are: plant height, number of leaves, total leaf area, net photosynthesis, transpiration, stomatal conductance, water use efficiency and net carbon assimilation. When harvesting, flower head diameter, head weight, stem weight, leaves weight, total number of seeds per plant and thousand seed weight were measured. The differences between mutants and also non irradiated genotype (AS-613) were significant for most of studied traits suggesting that several developmental processes have been modified [it

  14. Study on the conformal variations of bovine and human serum albumin in solution using small angle X-ray scattering

    International Nuclear Information System (INIS)

    Olivieri, Johnny Rizzieri.

    1992-01-01

    It is reported a Small Angle X-Ray Scattering (SAXS) study of BSA (Bovine Serum Albumin) and HSA (Human Serum Albumin) on pH between 2.5 and 7.0. The measured scattering intensities, normalized in relation to incident beam, exposition time and scattering due to solvent and capillary, and corrected due to concentration and beam shape effects, have shown a strong dependence of the protein shape with pH for both albumins. It was found that the radius of gyration varies between 26.7 and 35 A, and the analyses of the distance distribution function. P(r), indicated that these proteins undergoes conformational changes with pH. Different theoretical shapes have been proposed and analysed comparing the computed P(r) function generated from the models with the experimental P(r). A large variety of shapes were found in both proteins, indicating that BSA and HSA are very flexibility macromolecules. (author). 60 refs., 49 figs., 7 tabs

  15. Evaluation of variations in absorbed dose and image noise according to patient forms in X-ray computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Matsubara, Kosuke; Tsujii, Hideo; Yamamoto, Tomoyuki [Kanazawa Univ., Hospital, Kanazawa, Ishikawa (Japan); Koshida, Kichiro; Suzuki, Masayuki; Hayakawa, Mayumi [Kanazawa Univ., Graduate School of Medical Sciences, Kanazawa, Ishikawa (Japan)

    2005-12-15

    Excessive radiation exposure in pediatric computed tomography (CT) scanning has become a serious problem, and it is difficult to select scan parameters for the scanning of small patients such as children. We investigated differences in absorbed dose and standard deviation (SD) in Hounsfield unit (HU) caused by differences in the form of the subject using a body-type phantom with removable body parts. Using four X-ray CT scanners, measurements were made with values from 50 mAs to 300 mAs, with slices of 50 mAs, using scan protocols that were assumed to perform thorough examinations. The results showed that the mAs values and absorbed doses were almost proportional, and the absorbed doses in the phantom without body parts were about 1.1-2.2-fold higher than those of the phantom with body parts at the same points. The SD values obtained indicated that the absorbed doses in the phantom with body parts were 0.3-0.6 times those of the phantom without body parts when the mAs values used were adjusted so that both SD values were the same. The absorbed doses in various patient forms can be estimated from these results, and they will become critical data for the selection of appropriate scan protocols. (author)

  16. Characterisation and quantification of regional diurnal SST cycles from SEVIRI

    DEFF Research Database (Denmark)

    Karagali, Ioanna; Høyer, J.L.

    2014-01-01

    seas. Six years of SST fields from SEVIRI are validated against the Advanced Along-Track Scanning Radiometer (AATSR) Reprocessed for Climate (ARC) data set. The overall SEVIRI–AATSR bias is −0.07 K, and the standard deviation is 0.51 K, based on more than 53×106 matchups. Identification of the diurnal...... in the tropics. Longer diurnal warming duration is identified in the high latitudes compared to the tropics. The maximum monthly mean diurnal signal can be up to 0.5K in specific regions....

  17. Variation in the human ribs geometrical properties and mechanical response based on X-ray computed tomography images resolution.

    Science.gov (United States)

    Perz, Rafał; Toczyski, Jacek; Subit, Damien

    2015-01-01

    Computational models of the human body are commonly used for injury prediction in automobile safety research. To create these models, the geometry of the human body is typically obtained from segmentation of medical images such as computed tomography (CT) images that have a resolution between 0.2 and 1mm/pixel. While the accuracy of the geometrical and structural information obtained from these images depend greatly on their resolution, the effect of image resolution on the estimation of the ribs geometrical properties has yet to be established. To do so, each of the thirty-four sections of ribs obtained from a Post Mortem Human Surrogate (PMHS) was imaged using three different CT modalities: standard clinical CT (clinCT), high resolution clinical CT (HRclinCT), and microCT. The images were processed to estimate the rib cross-section geometry and mechanical properties, and the results were compared to those obtained from the microCT images by computing the 'deviation factor', a metric that quantifies the relative difference between results obtained from clinCT and HRclinCT to those obtained from microCT. Overall, clinCT images gave a deviation greater than 100%, and were therefore deemed inadequate for the purpose of this study. HRclinCT overestimated the rib cross-sectional area by 7.6%, the moments of inertia by about 50%, and the cortical shell area by 40.2%, while underestimating the trabecular area by 14.7%. Next, a parametric analysis was performed to quantify how the variations in the estimate of the geometrical properties affected the rib predicted mechanical response under antero-posterior loading. A variation of up to 45% for the predicted peak force and up to 50% for the predicted stiffness was observed. These results provide a quantitative estimate of the sensitivity of the response of the FE model to the resolution of the images used to generate it. They also suggest that a correction factor could be derived from the comparison between microCT and

  18. The influence of high and low levels of estrogen on diurnal urine regulation in young women

    Directory of Open Access Journals (Sweden)

    Bie Peter

    2008-11-01

    Full Text Available Abstract Background Sex hormones have a pronounced effect on arginine vasopressin (AVP, and therefore on the diurnal water homeostasis. Low and high levels of plasma-estradiol as seen in the follicular phase of the menstrual cycle may therefore alter the diurnal regulation of urine production. Furthermore the structural resemblance of oxytocin to vasopressin has led to speculations about the possible antidiuretic properties of oxytocin under normal physiological conditions. To elucidate the influence of high and low p-estradiol on the regulation of the diurnal urine production, 15 normal menstruating women (21–33 y underwent two circadian in-patient investigations, both situated in follicular phase. Methods Admitting the participants solely in the follicular phase resulted in high and low plasma-estradiol whereas plasma-progesterone was similar. Urine and blood samples were taken at predetermined time points to determine plasma AVP, plasma oxytocin, plasma aldosterone, plasma natriuretic peptide (ANP, urinary solute excretions, and urinary excretions of prostaglandin E2 (PGE-2 and aquaporin-2 (AQP-2. Blood pressure was measured every hour. Results Plasma AVP, plasma aldosterone and plasma ANP were unaffected by the different levels of estradiol. All had marked circadian variations whereas oxytocin did not display any circadian rhythm. High estradiol resulted in lower p-osmolality and p-sodium reflecting the downward resetting of the osmoreceptors. Oxytocin did not correlate with either diuresis or urine osmolality. The diurnal urine production was similar in the two groups as were urine osmolality, excretion of PGE-2 and AQP-2. AQP-2 does not have a circadian rhythm and is not significantly correlated to either AVP or oxytocin under normal physiological conditions. Conclusion High and low level of estradiol has no influence on the circadian rhythm of AVP or the subsequent urine production. High p-estradiol resets the osmoreceptors for AVP

  19. Diurnal Cycle of ITCZ Convection during the MJO Suppressed Phase in DYNAMO

    Science.gov (United States)

    Ciesielski, P. E.; Johnson, R. H.; Schubert, W. H.

    2017-12-01

    During the special observing period of the Dynamics of the MJO (DYNAMO) experiment, conducted over the Indian Ocean from 1 October to 30 November 2011, two sounding arrays - one north and one south of the equator, referred to here as the NSA and SSA, respectively - took 4-8 soundings/day. We augment this 3-h dataset with observations of radiation and rainfall to investigate the diurnal cycle of convection during the suppressed phase of the October MJO. During this 14-day period when convection was suppressed over the NSA but prominent over the SSA, the circulation over the sounding arrays could be characterized as a local Hadley cell embedded within a monsoonal flow. Strong rising motion was present within the ITCZ and compensating subsidence over the NSA. A prominent diurnal pulsing of this cell was observed, impacting conditions on both sides of the equator, with the cell running strongest in the early morning hours (05-08 LT) and notably weakening later in the day (17-20LT). The reduction in evening subsidence over the NSA may have assisted the moistening of the low to mid-troposphere there during the pre-onset stage of the MJO. Apparent heating Q1 within the ITCZ exhibits a diurnal evolution from early morning bottom-heavy profiles to weaker daytime top-heavy profiles. Making use of the weak temperature gradient approximation, results suggest that direct radiative effects played a dominant role in controlling diurnal variations of vertical motion and convection within the ITCZ while non-radiative processes were more prominent over the NSA.

  20. Cell cycle variation in x-ray survival for cells from spheroids measured by volume cell sorting

    International Nuclear Information System (INIS)

    Freyer, J.P.; Wilder, M.E.; Raju, M.R.

    1984-01-01

    Considerable work has been done studying the variation in cell survival as a function of cell cycle position for monolayers or single cells exposed to radiation. Little is known about the effects of multicellular growth on the relative radiation sensitivity of cells in different cell cycle stages. The authors have developed a new technique for measuring the response of cells, using volume cell sorting, which is rapid, non-toxic, and does not require cell synchronization. By combining this technique with selective spheroid dissociation,they have measured the age response of cells located at various depths in EMT6 and Colon 26 spheroids. Although cells in the inner region had mostly G1-phase DNA contents, 15-20% had S- and G2-phase DNA contents. Analysis of these cells using BrdU labeling and flow cytometric analysis with a monoclonal antibody to BrdU indicated that the inner region cells were not synthesizing DNA. Thus, the authors were able to measure the radiation response of cells arrested in G1, S and G2 cell cycle phases. Comparison of inner and outer spheroid regions, and monolayer cultures, indicates that it is improper to extrapolate age response data in standard culture conditions to the situation in spheroids

  1. A new Mumford-Shah total variation minimization based model for sparse-view x-ray computed tomography image reconstruction.

    Science.gov (United States)

    Chen, Bo; Bian, Zhaoying; Zhou, Xiaohui; Chen, Wensheng; Ma, Jianhua; Liang, Zhengrong

    2018-04-12

    Total variation (TV) minimization for the sparse-view x-ray computer tomography (CT) reconstruction has been widely explored to reduce radiation dose. However, due to the piecewise constant assumption for the TV model, the reconstructed images often suffer from over-smoothness on the image edges. To mitigate this drawback of TV minimization, we present a Mumford-Shah total variation (MSTV) minimization algorithm in this paper. The presented MSTV model is derived by integrating TV minimization and Mumford-Shah segmentation. Subsequently, a penalized weighted least-squares (PWLS) scheme with MSTV is developed for the sparse-view CT reconstruction. For simplicity, the proposed algorithm is named as 'PWLS-MSTV.' To evaluate the performance of the present PWLS-MSTV algorithm, both qualitative and quantitative studies were conducted by using a digital XCAT phantom and a physical phantom. Experimental results show that the present PWLS-MSTV algorithm has noticeable gains over the existing algorithms in terms of noise reduction, contrast-to-ratio measure and edge-preservation.

  2. Radiosensitivity variations in human tumor cell lines exposed in vitro to p(66)/Be neutrons or 60Co γ-rays

    International Nuclear Information System (INIS)

    Slabbert, J.P.; Theron, T.; Serafin, A.; Jones, D.T.L.; Boehm, L.; Schmitt, G.

    1996-01-01

    Neutron therapy should be beneficial to patients with tumor types which are resistant to photons but relatively sensitive to high-LET radiation. In this work the potential therapeutic gain of a clinical neutron beam is evaluated by quantifying the variations in radiosensitivity of different cell lines to neutrons and photons. Different cell lines were exposed in vitro to p(66)/Be neutrons or 60 Co γ-rays. Micronuclei frequencies in binucleated cells and surviving fractions were determined for each cell type. Following exposure to either 1 or 1.5 Gy neutrons, micronuclei frequencies were significantly correlated with that observed for 2 Gy photons. A weak but significant correlation between the variation in neutron RBE values,