WorldWideScience

Sample records for ocean age proportions

  1. Viking-Age Sails: Form and Proportion

    Science.gov (United States)

    Bischoff, Vibeke

    2017-04-01

    Archaeological ship-finds have shed much light on the design and construction of vessels from the Viking Age. However, the exact proportions of their sails remain unknown due to the lack of fully preserved sails, or other definite indicators of their proportions. Key Viking-Age ship-finds from Scandinavia—the Oseberg Ship, the Gokstad Ship and Skuldelev 3—have all revealed traces of rigging. In all three finds, the keelson—with the mast position—is preserved, together with fastenings for the sheets and the tack, indicating the breadth of the sail. The sail area can then be estimated based on practical experience of how large a sail the specific ship can carry, in conjunction with hull form and displacement. This article presents reconstructions of the form and dimensions of rigging and sail based on the archaeological finds, evidence from iconographic and written sources, and ethnographic parallels with traditional Nordic boats. When these sources are analysed, not only do the similarities become apparent, but so too does the relative disparity between the archaeological record and the other sources. Preferential selection in terms of which source is given the greatest merit is therefore required, as it is not possible to afford them all equal value.

  2. Crustal Ages of the Ocean Floor - Poster

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Crustal Ages of the Ocean Floor Poster was created at NGDC using the Crustal Ages of the Ocean Floor database draped digitally over a relief of the ocean floor...

  3. Austrian height and body proportion references for children aged 4 to under 19 years.

    Science.gov (United States)

    Gleiss, Andreas; Lassi, Michael; Blümel, Peter; Borkenstein, Martin; Kapelari, Klaus; Mayer, Michael; Schemper, Michael; Häusler, Gabriele

    2013-07-01

    Previous studies have demonstrated differences between national and the WHO reference curves in children older than 5 years. Moreover, reference curves for body proportions (sitting height, subischial leg length and their ratio) based on state-of-the-art statistics are not available. To develop reference curves for height and body proportions for use in Austria and compare the curves with WHO reference curves. To estimate and statistically investigate extreme percentiles. A sample of ∼14 500 children between 4-19 years of age was drawn via schooling institutions, stratified by provinces according to age- and sex-specific population proportions. GAMLSS models were used for a flexible estimation of percentile curves. After the age of 5 years national reference curves are more suitable than the WHO reference curves for clinical use in Austria. These height curves are very similar to the German reference curves published recently. Therefore, these reference curves for criteria of body proportions are recommended for use in other populations. Further validation studies are needed to establish whether the recently recommended -2.5 and -3.0 SD for height are a sensitive and specific cut-off in the diagnostic work-up for children with a suspected growth disorder using this new Austrian height chart.

  4. Argentine references for the assessment of body proportions from birth to 17 years of age.

    Science.gov (United States)

    Del Pino, Mariana; Orden, Alicia B; Arenas, María A; Fano, Virginia

    2017-06-01

    Abnormal body proportions may indicate skeletal disorders; therefore, their detection has great clinical significance. To estimate centiles for head circumference/height (HC/H) and sitting height/height (SH/H) ratios, and assess their diagnostic usefulness among a group of children with skeletal dysplasia. Centiles 3, 10, 25, 50, 75, 90 and 97 for HC/H and SH/H ratios were estimated with the LMS method using Box-Cox transformation to normalize data distribution for each age. Q-Q plot tests were applied to evaluate normality of residuals and the Q test to calculate goodness-of-fit. The sample included 4818 girls and4803 boys, all healthy, between 0-17 years old. The median of the SH/H ratio for each age decreased from 0.67 at birth to 0.57 at age 4. At 12 years of age, values reached 0.52 and 0.53 for males and females, respectively, remaining unchanged until age 17. The median of the HC/H ratio decreased from 0.45 at 6 years old to 0.34 at 17 years old for both sexes. Z-scores for SH/H among 20 children diagnosed with hypochondroplasia were better at showing abnormal proportions than the SH/H ratio not adjusted by age. Estimated centiles for HC/H and SH/H ratios show that the most dramatic changes in body proportions occur in the prepubertal period. These references allow an earlier detection of abnormal body proportions in children with skeletal dysplasia.

  5. Wolf (Canis lupus) generation time and proportion of current breeding females by age

    Science.gov (United States)

    Mech, L. David; Barber-Meyer, Shannon M.; Erb, John

    2016-01-01

    Information is sparse about aspects of female wolf (Canis lupus) breeding in the wild, including age of first reproduction, mean age of primiparity, generation time, and proportion of each age that breeds in any given year. We studied these subjects in 86 wolves (113 captures) in the Superior National Forest (SNF), Minnesota (MN), during 1972–2013 where wolves were legally protected for most of the period, and in 159 harvested wolves from throughout MN wolf range during 2012–2014. Breeding status of SNF wolves were assessed via nipple measurements, and wolves from throughout MN wolf range, by placental scars. In the SNF, proportions of currently breeding females (those breeding in the year sampled) ranged from 19% at age 2 to 80% at age 5, and from throughout wolf range, from 33% at age 2 to 100% at age 7. Excluding pups and yearlings, only 33% to 36% of SNF females and 58% of females from throughout MN wolf range bred in any given year. Generation time for SNF wolves was 4.3 years and for MN wolf range, 4.7 years. These findings will be useful in modeling wolf population dynamics and in wolf genetic and dog-domestication studies.

  6. DNA Methylation Patterns in Cord Blood of Neonates Across Gestational Age: Association With Cell-Type Proportions.

    Science.gov (United States)

    Braid, Susan M; Okrah, Kwame; Shetty, Amol; Corrada Bravo, Hector

    A statistical methodology is available to estimate the proportion of cell types (cellular heterogeneity) in adult whole blood specimens used in epigenome-wide association studies (EWAS). However, there is no methodology to estimate the proportion of cell types in umbilical cord blood (also a heterogeneous tissue) used in EWAS. The objectives of this study were to determine whether differences in DNA methylation (DNAm) patterns in umbilical cord blood are the result of blood cell type proportion changes that typically occur across gestational age and to demonstrate the effect of cell type proportion confounding by comparing preterm infants exposed and not exposed to antenatal steroids. We obtained DNAm profiles of cord blood using the Illumina HumanMethylation27k BeadChip array for 385 neonates from the Boston Birth Cohort. We estimated cell type proportions for six cell types using the deconvolution method developed by . The cell type proportion estimates segregated into two groups that were significantly different by gestational age, indicating that gestational age was associated with cell type proportion. Among infants exposed to antenatal steroids, the number of differentially methylated CpGs dropped from 127 to 1 after controlling for cell type proportion. EWAS utilizing cord blood are confounded by cell type proportion. Careful study design including correction for cell type proportion and interpretation of results of EWAS using cord blood are critical.

  7. Proportionality lost - proportionality regained?

    DEFF Research Database (Denmark)

    Werlauff, Erik

    2010-01-01

    In recent years, the European Court of Justice (the ECJ) seems to have accepted restrictions on the freedom of establishment and other basic freedoms, despite the fact that a more thorough proportionality test would have revealed that the restriction in question did not pass the 'rule of reason' ...

  8. Methods for using argon-39 to age-date groundwater using ultra-low-background proportional counting

    Energy Technology Data Exchange (ETDEWEB)

    Mace, Emily; Aalseth, Craig; Brandenberger, Jill; Day, Anthony; Hoppe, Eric; Humble, Paul; Keillor, Martin; Kulongoski, Justin; Overman, Cory; Panisko, Mark; Seifert, Allen; White, Signe; Wilcox Freeburg, Eric; Williams, Richard

    2017-08-01

    Argon-39 can be used as a tracer for age-dating glaciers, oceans, and more recently, groundwater. With a half-life of 269 years, 39Ar fills an intermediate age range gap (50-1,000 years) not currently covered by other common groundwater tracers. Therefore, adding this tracer to the data suite for groundwater studies provides an important tool for improving our understanding of groundwater systems. We present the methods employed for arriving at an age-date for a given sample of argon degassed from groundwater.

  9. Estimating a child's age from an image using whole body proportions.

    Science.gov (United States)

    Lucas, Teghan; Henneberg, Maciej

    2017-09-01

    The use and distribution of child pornography is an increasing problem. Forensic anthropologists are often asked to estimate a child's age from a photograph. Previous studies have attempted to estimate the age of children from photographs using ratios of the face. Here, we propose to include body measurement ratios into age estimates. A total of 1603 boys and 1833 girls aged 5-16 years were measured over a 10-year period. They are 'Cape Coloured' children from South Africa. Their age was regressed on ratios derived from anthropometric measurements of the head as well as the body. Multiple regression equations including four ratios for each sex (head height to shoulder and hip width, knee width, leg length and trunk length) have a standard error of 1.6-1.7 years. The error is of the same order as variation of differences between biological and chronological ages of the children. Thus, the error cannot be minimised any further as it is a direct reflection of a naturally occurring phenomenon.

  10. Children with low birth weight and low gestational age in Oslo, Norway: immigration is not the cause of increasing proportions.

    OpenAIRE

    Stoltenberg, C; Magnus, P

    1995-01-01

    STUDY OBJECTIVE--To determine the influence of children born to immigrant mothers on the total proportions of low birth weight and preterm deliveries in Oslo and to explain the increases in the proportions of children with low birth weight and low gestational age since 1980-1982. DESIGN--This was a cross sectional study based on Norwegian Medical Birth Registry data and information on mothers' country of birth from the Central Bureau of Statistics. SETTING--Oslo, Norway 1968-91. POPULATION--A...

  11. Assessing the living and dead proportions of cold-water coral colonies: implications for deep-water Marine Protected Area monitoring in a changing ocean

    Directory of Open Access Journals (Sweden)

    Johanne Vad

    2017-10-01

    Full Text Available Coral growth patterns result from an interplay of coral biology and environmental conditions. In this study colony size and proportion of live and dead skeletons in the cold-water coral (CWC Lophelia pertusa (Linnaeus, 1758 were measured using video footage from Remotely Operated Vehicle (ROV transects conducted at the inshore Mingulay Reef Complex (MRC and at the offshore PISCES site (Rockall Bank in the NE Atlantic. The main goal of this paper was to explore the development of a simple method to quantify coral growth and its potential application as an assessment tool of the health of these remote habitats. Eighteen colonies were selected and whole colony and dead/living layer size were measured. Live to dead layer ratios for each colony were then determined and analysed. The age of each colony was estimated using previously published data. Our paper shows that: (1 two distinct morphotypes can be described: at the MRC, colonies displayed a ‘cauliflower-shaped’ morphotype whereas at the PISCES site, colonies presented a more flattened ‘bush-shaped’ morphotype; (2 living layer size was positively correlated with whole colony size; (3 live to dead layer ratio was negatively correlated to whole colony size; (4 live to dead layer ratio never exceeded 0.27. These results suggest that as a colony develops and its growth rate slows down, the proportion of living polyps in the colony decreases. Furthermore, at least 73% of L. pertusa colonies are composed of exposed dead coral skeleton, vulnerable to ocean acidification and the associated shallowing of the aragonite saturation horizon, with significant implications for future deep-sea reef framework integrity. The clear visual contrast between white/pale living and grey/dark dead portions of the colonies also gives a new way by which they can be visually monitored over time. The increased use of marine autonomous survey vehicles offers an important new platform from which such a surveying

  12. [Proportion of breast cancer in women aged 50 to 69 years from Girona, Spain, according to detection method].

    Science.gov (United States)

    Puig-Vives, Montse; Osca-Gelis, Gemma; Camprubí-Font, Carla; Vilardell, M Loreto; Izquierdo, Angel; Marcos-Gragera, Rafael

    2014-10-07

    The aim of this study was to determine the tumor stage, the proportion of cases and the age specific rate of breast cancer (BC) cases according to detection method. Cases of women aged 50 to 69 years diagnosed with BC in the Girona province during 1999-2006 were extracted from the population-based Girona Cancer Registry (n=1,254). BC was classified by detection method: screen-detected cancer, interval cancer and others. Proportion of cases and age-specific incidence were calculated according to detection method. During the period 2002-2006, the proportion of screen-detected cancers, interval cancers and other cancers were 42.2%, 5.8% and 52.2%, respectively. After implementation of the early detection of breast cancer program (PDPCM), the incidence of screen-detected cases raised; thereafter, interval cancers also increased and the rate of other cancers decreased. In the Girona province during the fully implemented PDPCM period (2002-2006), interval cancers represented a low proportion (5.8%) of women diagnosed with BC at 50 to 69 years old. Copyright © 2013 Elsevier España, S.L.U. All rights reserved.

  13. Age, spreading rates, and spreading asymmetry of the world's ocean crust

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The authors present four companion digital models of the age, age uncertainty, spreading rates and spreading asymmetries of the world's ocean basins as geographic...

  14. Crustal tracers in the atmosphere and ocean: Relating their concentrations, fluxes, and ages

    Science.gov (United States)

    Han, Qin

    Crustal tracers are important sources of key limiting nutrients (e.g., iron) in remote ocean regions where they have a large impact on global biogeochemical cycles. However, the atmospheric delivery of bio-available iron to oceans via mineral dust aerosol deposition is poorly constrained. This dissertation aims to improve understanding and model representation of oceanic dust deposition and to provide soluble iron flux maps by testing observations of crustal tracer concentrations and solubilities against predictions from two conceptual solubility models. First, we assemble a database of ocean surface dissolved Al and incorporate Al cycling into the global Biogeochemical Elemental Cycling (BEC) model. The observed Al concentrations show clear basin-scale differences that are useful for constraining dust deposition. The dynamic mixed layer depth and Al residence time in the BEC model significantly improve the simulated dissolved Al field. Some of the remaining model-data discrepancies appear related to the neglect of aerosol size, age, and air mass characteristics in estimating tracer solubility. Next, we develop the Mass-Age Tracking method (MAT) to efficiently and accurately estimate the mass-weighted age of tracers. We apply MAT to four sizes of desert dust aerosol and simulate, for the first time, global distributions of aerosol age in the atmosphere and at deposition. These dust size and age distributions at deposition, together with independent information on air mass acidity, allow us to test two simple yet plausible models for predicting the dissolution of mineral dust iron and aluminum during atmospheric transport. These models represent aerosol solubility as controlled (1) by a diffusive process leaching nutrients from the dust into equilibrium with the liquid water coating or (2) by a process that continually dissolves nutrients in proportion to the particle surface area. The surface-controlled model better captures the spatial pattern of observed

  15. Greenhouse gas emissions from concrete can be reduced by using mix proportions, geometric aspects, and age as design factors

    Science.gov (United States)

    Miller, Sabbie A.; Horvath, Arpad; Monteiro, Paulo J. M.; Ostertag, Claudia P.

    2015-11-01

    With increased awareness of the emissions of greenhouse gases (GHGs) and the significant contribution from the cement industry, research efforts are being advanced to reduce the impacts associated with concrete production and consumption. A variety of methods have been proposed, one of the most common being the replacement of cement as a binder in concrete with supplementary cementitious materials, such as fly ash (FA), which can have lower environmental effects. The use of FA can change the kinetics of the hydration reactions and, consequently, modify the evolution of the concrete strength over time. Yet the influence of designing structural elements to obtain the required strength at later ages has not been examined in terms of their influence on global warming potential (GWP) of concrete. This research investigates the influence of design age, in addition to mix proportions and geometric aspects, on the GWP associated with making beams, columns, and a concrete building frame. Findings suggest that while the GWP for beams is not highly dependent on concrete mixture strength, the GWP for columns is dependent on strength, thus the influence of required strength at later ages influences GWP of making columns more so than beams. For the concrete frame analyzed, a potential 45% reduction in GWP, depending on mix proportions and design age, was found. Using the findings from this research, the GWP associated with production of concrete in California could be reduced by approximately 1.8 million metric tons of CO2-eq emissions, equivalent to approximately 2% of all industrial GHG emissions in California.

  16. Greenhouse gas emissions from concrete can be reduced by using mix proportions, geometric aspects, and age as design factors

    International Nuclear Information System (INIS)

    Miller, Sabbie A; Horvath, Arpad; Monteiro, Paulo J M; Ostertag, Claudia P

    2015-01-01

    With increased awareness of the emissions of greenhouse gases (GHGs) and the significant contribution from the cement industry, research efforts are being advanced to reduce the impacts associated with concrete production and consumption. A variety of methods have been proposed, one of the most common being the replacement of cement as a binder in concrete with supplementary cementitious materials, such as fly ash (FA), which can have lower environmental effects. The use of FA can change the kinetics of the hydration reactions and, consequently, modify the evolution of the concrete strength over time. Yet the influence of designing structural elements to obtain the required strength at later ages has not been examined in terms of their influence on global warming potential (GWP) of concrete. This research investigates the influence of design age, in addition to mix proportions and geometric aspects, on the GWP associated with making beams, columns, and a concrete building frame. Findings suggest that while the GWP for beams is not highly dependent on concrete mixture strength, the GWP for columns is dependent on strength, thus the influence of required strength at later ages influences GWP of making columns more so than beams. For the concrete frame analyzed, a potential 45% reduction in GWP, depending on mix proportions and design age, was found. Using the findings from this research, the GWP associated with production of concrete in California could be reduced by approximately 1.8 million metric tons of CO 2 -eq emissions, equivalent to approximately 2% of all industrial GHG emissions in California. (letter)

  17. Proportional reasoning

    DEFF Research Database (Denmark)

    Dole, Shelley; Hilton, Annette; Hilton, Geoff

    2015-01-01

    Proportional reasoning is widely acknowledged as a key to success in school mathematics, yet students’ continual difficulties with proportion-related tasks are well documented. This paper draws on a large research study that aimed to support 4th to 9th grade teachers to design and implement tasks...

  18. Parcels v0.9: prototyping a Lagrangian Ocean Analysis framework for the petascale age

    NARCIS (Netherlands)

    Lange, Michael; Sebille, Erik van

    2017-01-01

    As Ocean General Circulation Models (OGCMs) move into the petascale age, where the output from global high-resolution model runs can be of the order of hundreds of terabytes in size, tools to analyse the output of these models will need to scale up too. Lagrangian Ocean Analysis, where virtual

  19. Changes in wood product proportions in the Douglas-fir region with respect to size, age, and time.

    Science.gov (United States)

    R.A. Monserud; X. Zhou

    2007-01-01

    We examine both the variation and the changing proportions of different wood products obtained from trees and logs in the Douglas-fir region of the Northwestern United States. Analyses are based on a large product recovery database covering over 40 years of recovery studies; 13 studies are available for Douglas-fir (Pseudotsuga menziesii (Mirb.)...

  20. Age-related macular degeneration is associated with increased proportion of CD56(+) T cells in peripheral blood

    DEFF Research Database (Denmark)

    Faber, Carsten; Singh, Amardeep; Krüger Falk, Mads

    2013-01-01

    PURPOSE: To examine the association between age-related changes in the T-cell compartment and prevalence of age-related macular degeneration (AMD). DESIGN: Case-control study. PARTICIPANTS: A total of 117 AMD cases and 106 controls were included prospectively. METHODS: Fresh-drawn peripheral blood...... samples were processed for flow cytometric analysis of T-cell populations. Plasma samples were analyzed for anti-cytomegalovirus (CMV) immunoglobulin (Ig)G and complement factor H (CFH) Y402H genotype. The diagnosis of AMD was made according to the Clinical Age-Related Maculopathy Staging System. MAIN...... OUTCOME MEASURES: Association between frequency of aged T cells and prevalence of AMD. RESULTS: The prevalence of AMD was associated with distinct age-related changes in the T-cell compartment. Specifically, the patients with AMD had an increased frequency of CD28(-) T cells that expressed the CD56...

  1. The age and emplacement of obducted oceanic crust in the Urals from Sm-Nd and Rb-Sr systematics

    International Nuclear Information System (INIS)

    Edwards, R.L.; Wasserburg, G.J.

    1985-01-01

    The Urals contain a 2000 km belt of mafic-ultramafic bodies. The Sm-Nd and Rb-Sr systematics of two of these bodies, the Kempersai Massif in the South Ural Mountains and the Voykar-Syninsky Ophiolite Complex in the Polar Ural Mountains have been examined. These data confirm the hypothesis that these bodies represent fragments of pre-collision oceanic crust and establish constraints on the nature and timing of events in the Uralian Orogeny. Two Kempersai gabbros define Sm-Nd internal isochrons of 397 +- 20 My and 396 +- 33 My with epsilonsub(Nd)(T) = +8.7 -+ 0.6 and +8.4 -+ 1.3, respectively. Whole rock samples of pillow basalt, diabase, gabbros, troctolite, and a metasediment give Sm-Nd values which lie on this isochron indicating that these rocks are genetically related and have an igneous crystallization age of 397 My. Whole rock samples of Voykar-Syninsky diabase, gabbros, and clinopyroxenite give Sm-Nd values which lie on or within proportional 1 epsilon-unit of this isochron indicating an age and epsilonsub(Nd)(T) virtually identical to those of Kempersai. epsilonsub(Nd)(T) for the Kempersai and Voykar-Syninsky mafic samples range from +7.3 to +9.0 with an average value of +8.4. This indicates that the Urals ophiolites are derived from an ancient depleted mantle source and are most plausibly pieces of the oceanic crust and lithosphere. The fact that a metasediment has the same epsilonsub(Nd)(397 My) as the other samples indicates derivation from an oceanic source with negligible continental input. epsilonsub(Nd)(T) for the massifs is proportional 1.5 epsilon-units lower than the average for modern MORBs. (orig./HSI)

  2. Assessment of body fat proportion by means of bioelectrical impedance in athletic boys aged 7 to 18 years with respect to specific types of instruments

    Directory of Open Access Journals (Sweden)

    Sigmund Martin

    2015-07-01

    Full Text Available BACKGROUND: Bioelectrical impedance (BIA seems an appropriate method for basic diagnostics of body composition in a practical environment. This is a non-time consuming non-invasive method that provides a high degree of response relevance. However, the values identifi ed by the BIA method are susceptible to a number of factors, which need to be taken into account during the investigation stage and interpretation of the results. One of the signifi cant factors infl uencing the outcomes of measurement is the instrument factor.OBJECTIVE: The objective of the present comparative survey was to analyse the proportions of body fat by means of the BIA hand-to-leg method and BIA leg-to-leg method in a sample of athletic individuals aged 7 to 18 years.METHODS: The survey included a total of 178 ice-hockey players aged 7 to 18 years. The proportion of body fat analysed by means of the BIA hand-to-leg method was measured by the Tanita BC-418 MA instrument. For the purposes of the BIA leg-to-leg method the Tanita BF-350 instrument was used (Tanita, Japan. Both instruments work at a frequency of 50 kHz.RESULTS: The percentage of body fat established by the BIA leg-to-leg method (M = 13.5%; SD = 4.8 indicated signifi cantly lower values of fat percentage than the values measured by the BIA hand-to-leg method (M = 17.1%; SD = 4.3. The overall diff erence represents an average value of 3.6% (standard mode; p < .001; d = 0.8. Regarding the monitored age categories the observed diff erences are in the range of 3.1–4.7% (p < .001; d = 0.7–1.2.CONCLUSION: The present study compares the proportions of body fat by means of the BIA leg-to-leg method and BIA hand-to-leg method in athletic boys aged 7 to 18 years. The results measured by the BIA leg-to-leg method signifi cantly undervalue the proportion of body fat in comparison with the BIA hand-to-leg method. The instrument factor and age factor represented signifi - cant variables infl uencing the results of the

  3. Estimation of the geological age of oceanic basalts by track method

    International Nuclear Information System (INIS)

    Komarov, A.N.; Krylov, A.Ya.

    1977-01-01

    The method is described of the determination of the thermostability of tracks applied to oceanic basalts and the comparison is carried out of age values obtained for the same samples by the track method and by the potassium-argon method. The obtained results allow to consider that the track method is quite practicable for the dating of oceanic basalts on the condition that natural annealing of a part of tracks of the spontaneous uranium fission is taken into accout. For glasses of the other origin - tektites - such approach results in the agreement of the obtained values with the results of potassium-argon method

  4. Ethnic variability in body size, proportions and composition in children aged 5 to 11 years: is ethnic-specific calibration of bioelectrical impedance required?

    Directory of Open Access Journals (Sweden)

    Simon Lee

    Full Text Available Bioelectrical Impedance Analysis (BIA has the potential to be used widely as a method of assessing body fatness and composition, both in clinical and community settings. BIA provides bioelectrical properties, such as whole-body impedance which ideally needs to be calibrated against a gold-standard method in order to provide accurate estimates of fat-free mass. UK studies in older children and adolescents have shown that, when used in multi-ethnic populations, calibration equations need to include ethnic-specific terms, but whether this holds true for younger children remains to be elucidated. The aims of this study were to examine ethnic differences in body size, proportions and composition in children aged 5 to 11 years, and to establish the extent to which such differences could influence BIA calibration.In a multi-ethnic population of 2171 London primary school-children (47% boys; 34% White, 29% Black African/Caribbean, 25% South Asian, 12% Other detailed anthropometric measurements were performed and ethnic differences in body size and proportion were assessed. Ethnic differences in fat-free mass, derived by deuterium dilution, were further evaluated in a subsample of the population (n = 698. Multiple linear regression models were used to calibrate BIA against deuterium dilution.In children < 11 years of age, Black African/Caribbean children were significantly taller, heavier and had larger body size than children of other ethnicities. They also had larger waist and limb girths and relatively longer legs. Despite these differences, ethnic-specific terms did not contribute significantly to the BIA calibration equation (Fat-free mass = 1.12+0.71*(height2/impedance+0.18*weight.Although clear ethnic differences in body size, proportions and composition were evident in this population of young children aged 5 to 11 years, an ethnic-specific BIA calibration equation was not required.

  5. Interpretation of Ferroan Anorthosite Ages and Implications for the Lunar Magma Ocean

    Science.gov (United States)

    Neal, C. R.; Draper, D. S.

    2017-01-01

    Ferroan Anorthosites (FANs) are considered to have purportedly crystallized directly from the lunar magma ocean (LMO) as a flotation crust. LMO modeling suggests that such anorthosites started to form only after greater than 70 percent of the LMO had crystallized. Recent age dates for FANs have questioned this hypothesis as they span too large of an age range. This means a younger age for the Moon-forming giant impact or the LMO hypothesis is flawed. However, FANs are notoriously difficult to age-date using the isochron method. We have proposed a mechanism for testing the LMO hypothesis through using plagioclase trace element abundances to calculate equilibrium liquids and compare them with LMO crystallization models. We now examine the petrography of the samples that have Sm-Nd (Samarium-Neodymium) age dates (Rb-Sr (Rubidium-Strontium) isotopic systematics may have been disturbed) and propose a relative way to age date FANs.

  6. The role of social networks and media receptivity in predicting age of smoking initiation: a proportional hazards model of risk and protective factors.

    Science.gov (United States)

    Unger, J B; Chen, X

    1999-01-01

    The increasing prevalence of adolescent smoking demonstrates the need to identify factors associated with early smoking initiation. Previous studies have shown that smoking by social network members and receptivity to pro-tobacco marketing are associated with smoking among adolescents. It is not clear, however, whether these variables also are associated with the age of smoking initiation. Using data from 10,030 California adolescents, this study identified significant correlates of age of smoking initiation using bivariate methods and a multivariate proportional hazards model. Age of smoking initiation was earlier among those adolescents whose friends, siblings, or parents were smokers, and among those adolescents who had a favorite tobacco advertisement, had received tobacco promotional items, or would be willing to use tobacco promotional items. Results suggest that the smoking behavior of social network members and pro-tobacco media influences are important determinants of age of smoking initiation. Because early smoking initiation is associated with higher levels of addiction in adulthood, tobacco control programs should attempt to counter these influences.

  7. Proportion of preschool-aged children meeting the Canadian 24-Hour Movement Guidelines and associations with adiposity: results from the Canadian Health Measures Survey

    Directory of Open Access Journals (Sweden)

    Jean-Philippe Chaput

    2017-11-01

    Full Text Available Abstract Background New Canadian 24-Hour Movement Guidelines for the Early Years have been released in 2017. According to the guidelines, within a 24-h period, preschoolers should accumulate at least 180 min of physical activity (of which at least 60 min is moderate-to-vigorous physical activity, engage in no more than 1 h of screen time, and obtain between 10 and 13 h of sleep. This study examined the proportions of preschool-aged (3 to 4 years Canadian children who met these new guidelines and different recommendations within the guidelines, and the associations with adiposity indicators. Methods Participants were 803 children (mean age: 3.5 years from cycles 2–4 of the Canadian Health Measures Survey (CHMS, a nationally representative cross-sectional sample of Canadians. Physical activity was accelerometer-derived, and screen time and sleep duration were parent-reported. Participants were classified as meeting the overall 24-Hour Movement Guidelines if they met all three specific time recommendations for physical activity, screen time, and sleep. The adiposity indicators in this study were body mass index (BMI z-scores and BMI status (World Health Organization Growth Standards. Results A total of 12.7% of preschool-aged children met the overall 24-Hour Movement Guidelines, and 3.3% met none of the three recommendations. A high proportion of children met the sleep duration (83.9% and physical activity (61.8% recommendations, while 24.4% met the screen time recommendation. No associations were found between meeting individual or combined recommendations and adiposity. Conclusions Very few preschool-aged children in Canada (~13% met all three recommendations contained within the 24-Hour Movement Guidelines. None of the combinations of recommendations were associated with adiposity in this sample. Future work should focus on identifying innovative ways to reduce screen time in this population, and should examine the associations of

  8. Iron fertilization of the Subantarctic Ocean during the last ice age

    Science.gov (United States)

    Martinez-Garcia, A.

    2015-12-01

    Dust has the potential to modify global climate by influencing the radiative balance of the atmosphere and by supplying iron and other essential limiting micronutrients to the ocean. The scarcity of iron limits marine productivity and carbon uptake in one-quarter of the world ocean where the concentration of major nutrients (phosphorus and nitrogen) is perennially high. The Southern Ocean is the region where variations in iron availability can have the largest effect on Earth's carbon cycle through its fertilizing effect on marine ecosystems. Paleoceanographic records from the Subantarctic Atlantic have revealed a remarkable correlation between phytoplankton productivity and aeolian iron flux during glacial periods supporting the iron fertilization hypothesis. In addition, a recent study has shown that peak glacial times and millennial cold events were nearly universally associated not only with increases in dust flux and export production, but also with an increase in nutrient consumption (the last indicated by higher foraminifera-bound δ15N) (Martinez-Garcia et al. 2014). This combination of changes is uniquely consistent with ice age iron fertilization of the Subantarctic Atlantic. The strengthening of the biological pump associated with the observed increase in Subantarctic nutrient consumption during the high-dust intervals of the last two ice ages can explain up to ~40 ppm of the CO2 decrease that characterizes the transitions from mid-climate states to full ice age conditions. However, the impact of iron fertilization in other sectors of the Southern Ocean characterized by lower ice age dust fluxes than the Atlantic remains unclear. A series of recently published records from the Subantarctic Pacific indicate that dust deposition and marine export production were three times higher during glacial periods than during interglacials (Lamy et al. 2014). Here we present new measurements of foraminifera-bound nitrogen isotopes in a sediment core located in the

  9. Variation with age of anisotropy under oceans, from great circle surface waves

    International Nuclear Information System (INIS)

    Journet, B.; Jobert, N.

    1982-01-01

    Global great circle measurements of regionalized mantle Love wave phase velocities are interpreted in terms of regional models. The same study had been made by J. J. Leveque (1980) for Rayleigh waves, and the resulting models for the two oceanic regions of different ages are used as a basis for comparison: the observed Love wave dispersion cannot be explained with these models if isotropic. The models obtained by inversion of Love wave data are compared with the models mentioned; the discrepancy appearing in the 250 km depth range between the velocities β/sub H/ and β/sub V/ of respectively SH and SV waves is indicative of polarization anisotropy. Moreover, we put forward a significant variation from young to old oceans: the difference between β/sub H/, and β/sub V/ is of the order of 1% for the former, compared to 3% for the latter. This variation can bring information about the behaviour of upper mantle materials in connection with the motion of oceanic plates

  10. Modelling the chemically aged and mixed aerosols over the eastern central Atlantic Ocean – potential impacts

    Directory of Open Access Journals (Sweden)

    M. Astitha

    2010-07-01

    Full Text Available Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size distribution, using chemistry-transport models, satellite data and in situ measurements. We focus on August 2005, a period with intense hurricane and tropical storm activity over the Atlantic Ocean. A mixture of anthropogenic (sulphates, nitrates, natural (desert dust, sea salt and chemically aged (sulphate and nitrate on dust aerosols is found entering the hurricane genesis region, most likely interacting with clouds in the area. Results from our modelling study suggest rather small amounts of accumulation mode desert dust, sea salt and chemically aged dust aerosols in this Atlantic Ocean region. Aerosols of smaller size (Aitken mode are more abundant in the area and in some occasions sulphates of anthropogenic origin and desert dust are of the same magnitude in terms of number concentrations. Typical aerosol number concentrations are derived for the vertical layers near shallow cloud formation regimes, indicating that the aerosol number concentration can reach several thousand particles per cubic centimetre. The vertical distribution of the aerosols shows that the desert dust particles are often transported near the top of the marine cloud layer as they enter into the region where deep convection is initiated. The anthropogenic sulphate aerosol can be transported within a thick layer and enter the cloud deck through multiple ways (from the top, the base of the cloud, and by entrainment. The sodium (sea salt related aerosol is mostly found below the cloud base. The results of this work may provide insights relevant for studies that consider aerosol influences on cloud processes and storm development in the Central Atlantic region.

  11. Seafloor age dependence of Rayleigh wave phase velocities in the Indian Ocean

    Science.gov (United States)

    Godfrey, Karen E.; Dalton, Colleen A.; Ritsema, Jeroen

    2017-05-01

    Variations in the phase velocity of fundamental-mode Rayleigh waves across the Indian Ocean are determined using two inversion approaches. First, variations in phase velocity as a function of seafloor age are estimated using a pure-path age-dependent inversion method. Second, a two-dimensional parameterization is used to solve for phase velocity within 1.25° × 1.25° grid cells. Rayleigh wave travel time delays have been measured between periods of 38 and 200 s. The number of measurements in the study area ranges between 4139 paths at a period of 200 s and 22,272 paths at a period of 40 s. At periods Rodriguez Triple Junction and the Australian-Antarctic Discordance and anomalously low velocities immediately to the west of the Central Indian Ridge.

  12. No iron fertilization in the equatorial Pacific Ocean during the last ice age.

    Science.gov (United States)

    Costa, K M; McManus, J F; Anderson, R F; Ren, H; Sigman, D M; Winckler, G; Fleisher, M Q; Marcantonio, F; Ravelo, A C

    2016-01-28

    The equatorial Pacific Ocean is one of the major high-nutrient, low-chlorophyll regions in the global ocean. In such regions, the consumption of the available macro-nutrients such as nitrate and phosphate is thought to be limited in part by the low abundance of the critical micro-nutrient iron. Greater atmospheric dust deposition could have fertilized the equatorial Pacific with iron during the last ice age--the Last Glacial Period (LGP)--but the effect of increased ice-age dust fluxes on primary productivity in the equatorial Pacific remains uncertain. Here we present meridional transects of dust (derived from the (232)Th proxy), phytoplankton productivity (using opal, (231)Pa/(230)Th and excess Ba), and the degree of nitrate consumption (using foraminifera-bound δ(15)N) from six cores in the central equatorial Pacific for the Holocene (0-10,000 years ago) and the LGP (17,000-27,000 years ago). We find that, although dust deposition in the central equatorial Pacific was two to three times greater in the LGP than in the Holocene, productivity was the same or lower, and the degree of nitrate consumption was the same. These biogeochemical findings suggest that the relatively greater ice-age dust fluxes were not large enough to provide substantial iron fertilization to the central equatorial Pacific. This may have been because the absolute rate of dust deposition in the LGP (although greater than the Holocene rate) was very low. The lower productivity coupled with unchanged nitrate consumption suggests that the subsurface major nutrient concentrations were lower in the central equatorial Pacific during the LGP. As these nutrients are today dominantly sourced from the Subantarctic Zone of the Southern Ocean, we propose that the central equatorial Pacific data are consistent with more nutrient consumption in the Subantarctic Zone, possibly owing to iron fertilization as a result of higher absolute dust fluxes in this region. Thus, ice-age iron fertilization in the

  13. Parcels v0.9: prototyping a Lagrangian ocean analysis framework for the petascale age

    Science.gov (United States)

    Lange, Michael; van Sebille, Erik

    2017-11-01

    As ocean general circulation models (OGCMs) move into the petascale age, where the output of single simulations exceeds petabytes of storage space, tools to analyse the output of these models will need to scale up too. Lagrangian ocean analysis, where virtual particles are tracked through hydrodynamic fields, is an increasingly popular way to analyse OGCM output, by mapping pathways and connectivity of biotic and abiotic particulates. However, the current software stack of Lagrangian ocean analysis codes is not dynamic enough to cope with the increasing complexity, scale and need for customization of use-cases. Furthermore, most community codes are developed for stand-alone use, making it a nontrivial task to integrate virtual particles at runtime of the OGCM. Here, we introduce the new Parcels code, which was designed from the ground up to be sufficiently scalable to cope with petascale computing. We highlight its API design that combines flexibility and customization with the ability to optimize for HPC workflows, following the paradigm of domain-specific languages. Parcels is primarily written in Python, utilizing the wide range of tools available in the scientific Python ecosystem, while generating low-level C code and using just-in-time compilation for performance-critical computation. We show a worked-out example of its API, and validate the accuracy of the code against seven idealized test cases. This version 0.9 of Parcels is focused on laying out the API, with future work concentrating on support for curvilinear grids, optimization, efficiency and at-runtime coupling with OGCMs.

  14. Parcels v0.9: prototyping a Lagrangian ocean analysis framework for the petascale age

    Directory of Open Access Journals (Sweden)

    M. Lange

    2017-11-01

    Full Text Available As ocean general circulation models (OGCMs move into the petascale age, where the output of single simulations exceeds petabytes of storage space, tools to analyse the output of these models will need to scale up too. Lagrangian ocean analysis, where virtual particles are tracked through hydrodynamic fields, is an increasingly popular way to analyse OGCM output, by mapping pathways and connectivity of biotic and abiotic particulates. However, the current software stack of Lagrangian ocean analysis codes is not dynamic enough to cope with the increasing complexity, scale and need for customization of use-cases. Furthermore, most community codes are developed for stand-alone use, making it a nontrivial task to integrate virtual particles at runtime of the OGCM. Here, we introduce the new Parcels code, which was designed from the ground up to be sufficiently scalable to cope with petascale computing. We highlight its API design that combines flexibility and customization with the ability to optimize for HPC workflows, following the paradigm of domain-specific languages. Parcels is primarily written in Python, utilizing the wide range of tools available in the scientific Python ecosystem, while generating low-level C code and using just-in-time compilation for performance-critical computation. We show a worked-out example of its API, and validate the accuracy of the code against seven idealized test cases. This version 0.9 of Parcels is focused on laying out the API, with future work concentrating on support for curvilinear grids, optimization, efficiency and at-runtime coupling with OGCMs.

  15. Positive geothermal anomalies in oceanic crust of Cretaceous age offshore Kamchatka

    Directory of Open Access Journals (Sweden)

    G. Delisle

    2011-09-01

    Full Text Available Heat flow measurements were carried out in 2009 offshore Kamchatka during the German-Russian joint-expedition KALMAR. An area with elevated heat flow in oceanic crust of Cretaceous age – detected ~30 yr ago in the course of several Russian heat flow surveys – was revisited. One previous interpretation postulated anomalous lithospheric conditions or a connection between a postulated mantle plume at great depth (>200 km as the source for the observed high heat flow. However, the positive heat flow anomaly – as our bathymetric data show – is closely associated with the fragmentation of the western flank of the Meiji Seamount into a horst and graben structure initiated during descent of the oceanic crust into the subduction zone offshore Kamchatka. This paper offers an alternative interpretation, which connects high heat flow primarily with natural convection of fluids in the fragmented rock mass and, as a potential additional factor, high rates of erosion, for which evidence is available from our collected bathymetric image. Given high erosion rates, warm rock material at depth rises to nearer the sea floor, where it cools and causes temporary elevated heat flow.

  16. Statistical averaging of marine magnetic anomalies and the aging of oceanic crust.

    Science.gov (United States)

    Blakely, R.J.

    1983-01-01

    Visual comparison of Mesozoic and Cenozoic magnetic anomalies in the North Pacific suggests that older anomalies contain less short-wavelength information than younger anomalies in this area. To test this observation, magnetic profiles from the North Pacific are examined from crust of three ages: 0-2.1, 29.3-33.1, and 64.9-70.3Ma. For each time period, at least nine profiles were analyzed by 1) calculating the power density spectrum of each profile, 2) averaging the spectra together, and 3) computing a 'recording filter' for each time period by assuming a hypothetical seafloor model. The model assumes that the top of the source is acoustic basement, the source thickness is 0.5km, and the time scale of geomagnetic reversals is according to Ness et al. (1980). The calculated power density spectra of the three recording filters are complex in shape but show an increase of attenuation of short-wavelength information as the crust ages. These results are interpreted using a multilayer model for marine magnetic anomalies in which the upper layer, corresponding to pillow basalt of seismic layer 2A, acts as a source of noise to the magnetic anomalies. As the ocean crust ages, this noisy contribution by the pillow basalts becomes less significant to the anomalies. Consequently, magnetic sources below layer 2A must be faithful recorders of geomagnetic reversals.-AuthorPacific power density spectrum

  17. Past and future ice age initiation: the role of an intrinsic deep-ocean millennial oscillation

    Science.gov (United States)

    Johnson, R. G.

    2014-05-01

    This paper offers three interdependent contributions to studies of climate variation: (1) the recognition and analysis of an intrinsic millennial oceanic oscillation that affects both Northern and Southern high latitude climates, (2) The recognition of an oceanographic switch to ice-free seas west of Greenland that explains the initiation of the Last Ice Age, and (3) an analysis of the effect of increasing salinity in the seas east of Greenland that suggests the possibility of the initiation of an ice age threshold climate in the near future. In the first contribution the millennial oscillation in the flow of the North Atlantic Drift reported by Bond et al. (1997) is proposed to be part of a 1500 yr intrinsic deep ocean oscillation. This oscillation involves the exchange of North Atlantic intermediate-level deep water (NADW) formed in the seas east of Greenland with Antarctic Bottom Water formed in a shallow-water zone at the edge of the Antarctic continent. The concept of NADW formation is already well known, with details of the sinking water flowing out of the Greenland Sea observed by Smethie et al. (2000) using chlorofluorocarbon tracers. The concept of Antarctic Bottom Water formation is also already well established. However, its modulation by the changing fraction of NADW in the Southern Ocean, which I infer from the analysis of Weyl (1968), has not been previously discussed. The modulated lower-salinity Antarctic Bottom Water that reaches the northern North Atlantic then provides negative feedback for the cyclic variation of NADW formation as proposed here. This causes the 1500 yr bipolar oscillation. The feedback suggests the possible sinusoidal character of the proposed oscillation model. The model is consistent with the cooling of the Little Ice Age (Lamb, 1972, 1995), and it also correctly predicts NASA's observation of today's record maximum area of winter sea ice on the Southern Ocean and the present observed record low rate of Antarctic Bottom Water

  18. Proportionality for Military Leaders

    National Research Council Canada - National Science Library

    Brown, Gary D

    2000-01-01

    .... Especially lacking is a realization that there are four distinct types of proportionality. In determining whether a particular resort to war is just, national leaders must consider the proportionality of the conflict (i.e...

  19. Atmosphere and ocean dynamics: contributors to the European Little Ice Age?

    Energy Technology Data Exchange (ETDEWEB)

    Palastanga, V.; Schrier, G. van der; Weber, S.L. [Royal Netherlands Meteorological Institute (KNMI), P.O. Box 201, De Bilt (Netherlands); Kleinen, T. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom); Max Planck Institute for Meteorology, Hamburg (Germany); Briffa, K.R.; Osborn, T.J. [University of East Anglia, Climatic Research Unit, School of Environmental Sciences, Norwich (United Kingdom)

    2011-03-15

    The role of a reduction in the Atlantic meridional overturning and that of a persistently negative North Atlantic Oscillation in explaining the coldness of the European Little Ice Age (LIA) has been assessed in two sets of numerical experiments. These experiments are performed using an intermediate complexity climate model and a full complexity GCM. The reduction in the Meridional Overturning Circulation (MOC) of ca. 25% is triggered by a conventional fresh-water hosing set-up. A persistently negative NAO winter circulation, at NAO-index value -0.5, is imposed using recently developed data-assimilation techniques applicable on paleoclimatic timescales. The hosing experiments lead to a reduction in oceanic meridional heat transport and cooler sea-surface temperatures. Next to a direct cooling effect on European climate, the change in ocean surface temperatures feedback on the atmospheric circulation modifying European climate significantly. The data-assimilation experiments showed a reduction of winter temperatures over parts of Europe, but there is little persistence into the summer season. The output of all model experiments are compared to reconstructions of winter and summer temperature based on the available temperature data for the LIA period. This demonstrates that the hypothesis of a persistently negative NAO as an explanation for the European LIA does not hold. The hosing experiments do not clearly support the hypothesis that a reduction in the MOC is the primary driver of LIA climate change. However, a reduction in the Atlantic overturning might have been a cause of the European LIA climate, depending on whether there is a strong enough feedback on the atmospheric circulation. (orig.)

  20. Changes in the poleward energy flux by the atmosphere and ocean as a possible cause for ice ages

    Energy Technology Data Exchange (ETDEWEB)

    Newell, R E

    1974-01-01

    It is proposed that the two preferred modes of temperature and circulation of the atmosphere which occurred over the past 100,000 yr correspond to two modes of partitioning of the poleward energy flux between the atmosphere and ocean. At present the ocean carries an appreciable fraction of the transport, for example about three-eighths at 30/sup 0/N. In the cold mode it is suggested that the ocean carries less, and the atmosphere more, than at present. During the formation of the ice, at 50,000 BP, for example, the overall flux is expected to be slightly lower than at present and during melting, at 16,000 BP, slightly higher. The transition between the modes is seen as a natural imbalance in the atmosphere-ocean energy budget with a gradual warming of the ocean during an Ice Age eventually culminating in its termination. At the present the imbalance is thought to correspond to a natural cooling of the ocean, which will lead to the next Ice Age. The magnitude of temperature changes in the polar regions differ between the hemispheres in the same way as present seasonal changes, being larger in the northern than in the southern hemisphere. Overall the atmospheric energy cycle was more intense during the Ice Ages than now. Observational tests are proposed by which predictions from the present arguments may be compared with deductions about the environment of the past. Data used for the present state of the atmospheric general circulation are the latest global data available and contain no known major uncertainties. However, data for the oceanic circulation and energy budget are less well known for the present and almost unknown for the past. Hence the proposed imbalances must be treated as part of a speculative hypothesis, but one which eventually may be subject to observational test as no solar variability is invoked.

  1. Accounting for age uncertainty in growth modeling, the case study of yellowfin tuna (Thunnus albacares of the Indian Ocean.

    Directory of Open Access Journals (Sweden)

    Emmanuelle Dortel

    Full Text Available Age estimates, typically determined by counting periodic growth increments in calcified structures of vertebrates, are the basis of population dynamics models used for managing exploited or threatened species. In fisheries research, the use of otolith growth rings as an indicator of fish age has increased considerably in recent decades. However, otolith readings include various sources of uncertainty. Current ageing methods, which converts an average count of rings into age, only provide periodic age estimates in which the range of uncertainty is fully ignored. In this study, we describe a hierarchical model for estimating individual ages from repeated otolith readings. The model was developed within a Bayesian framework to explicitly represent the sources of uncertainty associated with age estimation, to allow for individual variations and to include knowledge on parameters from expertise. The performance of the proposed model was examined through simulations, and then it was coupled to a two-stanza somatic growth model to evaluate the impact of the age estimation method on the age composition of commercial fisheries catches. We illustrate our approach using the sagittal otoliths of yellowfin tuna of the Indian Ocean collected through large-scale mark-recapture experiments. The simulation performance suggested that the ageing error model was able to estimate the ageing biases and provide accurate age estimates, regardless of the age of the fish. Coupled with the growth model, this approach appeared suitable for modeling the growth of Indian Ocean yellowfin and is consistent with findings of previous studies. The simulations showed that the choice of the ageing method can strongly affect growth estimates with subsequent implications for age-structured data used as inputs for population models. Finally, our modeling approach revealed particularly useful to reflect uncertainty around age estimates into the process of growth estimation and it can

  2. The Medieval Climate Anomaly and Little Ice Age in Chesapeake Bay and the North Atlantic Ocean

    Science.gov (United States)

    Cronin, T. M.; Hayo, K.; Thunell, R.C.; Dwyer, G.S.; Saenger, C.; Willard, D.A.

    2010-01-01

    A new 2400-year paleoclimate reconstruction from Chesapeake Bay (CB) (eastern US) was compared to other paleoclimate records in the North Atlantic region to evaluate climate variability during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA). Using Mg/Ca ratios from ostracodes and oxygen isotopes from benthic foraminifera as proxies for temperature and precipitation-driven estuarine hydrography, results show that warmest temperatures in CB reached 16-17. ??C between 600 and 950. CE (Common Era), centuries before the classic European Medieval Warm Period (950-1100. CE) and peak warming in the Nordic Seas (1000-1400. CE). A series of centennial warm/cool cycles began about 1000. CE with temperature minima of ~. 8 to 9. ??C about 1150, 1350, and 1650-1800. CE, and intervening warm periods (14-15. ??C) centered at 1200, 1400, 1500 and 1600. CE. Precipitation variability in the eastern US included multiple dry intervals from 600 to 1200. CE, which contrasts with wet medieval conditions in the Caribbean. The eastern US experienced a wet LIA between 1650 and 1800. CE when the Caribbean was relatively dry. Comparison of the CB record with other records shows that the MCA and LIA were characterized by regionally asynchronous warming and complex spatial patterns of precipitation, possibly related to ocean-atmosphere processes. ?? 2010.

  3. Uranium-lead isotopic ages of the Samail ophiolite, Oman, with applicatons to Tethyan ocean ridge tectonics

    International Nuclear Information System (INIS)

    Tilton, G.R.; Hopson, C.A.; Wright, J.E.

    1981-01-01

    Plagiogranites are a minor but widespread component of the Samail ophiolite plutonic member. They crystallized from the most fractionated melts generated by magmatic crystallization and differentiation of a steady state magma chamber beneath the Tethyan spreading ocean ridge, and their ages are thought to mark the time of ocean crust formation. Isotopic U--Pb ages of zircons from 13 plagiogranites collected along a 270-km segment of the Samail ophiolite subparallel to the regional trend of the sheeted dike complex (the former spreading ridge axis direction) define a narrow time interval of 93.5--97.9 m.y., with a pronounced clustering about 95 m.y. The zircon ages of the plagiogranites agree remarkably well with the early Cenomanian to early Turonian biostratigraphic ages of sediments that are intercalated within the ophiolite pillow lavas and that lie just above them (Tippit et al., 1981). The agreement of radiometric and biostratigraphic ages provides strong support for the conclusion that the plagiogranite U--Pb ages closely date the time span of ocean crust formation. No step changes in age patterns are observed along the ridge axis (sheeted dike) direction, suggesting that there are no major internal offsets of the ophiolite by transform or other faults along most of the traverse. One possible exception occurs at the southeastern end of the sampled interval (Ibra area), where a 3 m.y. discontinuity might be caused by an unmapped fault. Assuming that the regional trend of the sheeted dikes (N10 0 --25 0 W) marks the direction of the former spreading ridge axis, the present array of sample localities spans a distance of 130 to 195 km normal to that axis (i.e., in the spreading direction). The data as a whole do not define a clear-cut age trend normal to the spreading axis, but by eliminating samples that may be aberrant due to faulting, the data array suggests a pattern of increasing ages from east to west

  4. The Principle of Proportionality

    DEFF Research Database (Denmark)

    Bennedsen, Morten; Meisner Nielsen, Kasper

    2005-01-01

    Recent policy initiatives within the harmonization of European company laws have promoted a so-called "principle of proportionality" through proposals that regulate mechanisms opposing a proportional distribution of ownership and control. We scrutinize the foundation for these initiatives...... in relationship to the process of harmonization of the European capital markets.JEL classifications: G30, G32, G34 and G38Keywords: Ownership Structure, Dual Class Shares, Pyramids, EU companylaws....

  5. Surface Ocean Radiocarbon Reservoir Ages From Land-Sea Tephra Correlation Constrains Deglacial Chronology and Ocean Circulation in the Southeast Bering Sea

    Science.gov (United States)

    Cook, M. S.; Miller, R.; White-Nockleby, C.; Chapman, A.; Mix, A. C.

    2017-12-01

    Radiocarbon estimates of the past ocean are valuable because unlike passive tracers, radiocarbon has the potential to trace both the distribution and rate of transport of water masses. Most studies using paired radiocarbon measurements on planktonic and benthic foraminifera assume that the surface reservoir age was constant at the preindustrial value, which if incorrect, can strongly bias radiocarbon reconstructions. The subarctic Pacific is ringed by volcanic arcs, and there is great potential to use tephrochronology as a stratigraphic tool in sediments from the last glacial and deglaciation, and assign calendar ages to the marine sediment without relying on calibrated planktonic radiocarbon ages. In this study, we use major and trace element analysis of volcanic glass to match tephras between radiocarbon-dated lake cores from Sanak Island in the eastern Aleutians to marine cores from Umnak Plateau in the southeast Bering Sea. There are numerous thin tephras preserved in laminated sediments from the Bolling-Allerod and early Holocene in marine cores from depths (1000-1500 m) within the modern oxygen minimum zone. We find that trace elements are crucial in distinguishing tephras from individual eruptions. Our preliminary radiocarbon measurements suggest that the benthic-atmosphere radiocarbon differences and marine surface reservoir ages in the Bolling-Allerod are similar to pre-industrial values, supporting previously published radiocarbon reconstructions from the region.

  6. Late Cretaceous and Cenozoic seafloor and oceanic basement roughness: Spreading rate, crustal age and sediment thickness correlations

    Science.gov (United States)

    Bird, Robert T.; Pockalny, Robert A.

    1994-05-01

    Single-channel seismic data from the South Australian Basin and Argentine Basin, and bathymetry data from the flanks of the Mid-Atlantic Ridge, East Pacific Rise and Southwest Indian Ridge are analysed to determine the root-mean-square (RMS) roughness of the seafloor and oceanic basement created at seafloor spreading rates ranging from 3 to 80 km/Ma (half-rate). For these data, crustal ages range from near zero to 85 Ma and sediment thicknesses range from near zero to over 2 km. Our results are consistent with a negative correlation of basement roughness and spreading rate where roughness decreases dramatically through the slow-spreading regime (oceanic basement roughness and spreading rate appears to have existed since the late Cretaceous for slow and intermediate spreading rates, suggesting that the fundamental processes creating abyssal hill topography may have remained the same for this time period. Basement roughness does not appear to decrease (smooth) with increasing crustal age, and therefore off-ridge degradation of abyssal hill topography by mass wasting is not detected by our data. Seismic data reveal that sediment thickness increases with increasing crustal age in the South Australian Basin and Argentine Basin, but not monotonically and with significant regional variation. We show that minor accumulations of sediment can affect roughness significantly. Average sediment accumulations of less that 50 m (for our 100 km long sample seismic profiles and half-spreading rates ocean ridges.

  7. Radiocarbon age of the recent deposits of the Indian Ocean western part (Seychelles)

    International Nuclear Information System (INIS)

    Svitoch, A.A.; Parunin, O.B.

    1988-01-01

    Mass radiocarbon dating according to Pleistocene precipitations of the islands of the Western Part of the Indian ocean is carried out. Time of formation of black-rock precipitations, low benches and island sandstones of low islands - middle-late Holocene - is established. Rocks of a reef complex are late Pleistocene. Relative concentration of dates according to various types of deposits points to the trustworthness and testifies about usefulness of radiocarbon analysis for stratigraphic and chronological separation of carbonate precipitations of islands of the equatorial zone of the ocean

  8. Modelling the chemically aged and mixed aerosols over the eastern central Atlantic Ocean-potential impacts

    NARCIS (Netherlands)

    Astitha, M.; Kallos, G.; Spyrou, C.; O'Hirok, W.; Lelieveld, J.; Denier Gon, H.A.C. van der

    2010-01-01

    Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size

  9. Chemically aged and mixed aerosols over the Central Atlantic Ocean - Potential impacts

    NARCIS (Netherlands)

    Astitha, M.; Kallos, G.; Spyrou, C.; O'Hirok, W.; Lelieveld, J.; Denier Gon, H.A.C. van der

    2010-01-01

    Detailed information on the chemical and physical properties of aerosols is important for assessing their role in air quality and climate. This work explores the origin and fate of continental aerosols transported over the Central Atlantic Ocean, in terms of chemical composition, number and size

  10. Mauritius since the last ice age: paleoecology and climate of an oceanic island

    NARCIS (Netherlands)

    de Boer, E.J.

    2014-01-01

    Four centuries of human occupation has left Mauritius with <5% of its original vegetation cover. Consequently, little is known about floral and faunal distribution patterns and long-term ecological processes of this oceanic island. By using paleoecological techniques we record the impact of

  11. Multiwire proportional chamber development

    Science.gov (United States)

    Doolittle, R. F.; Pollvogt, U.; Eskovitz, A. J.

    1973-01-01

    The development of large area multiwire proportional chambers, to be used as high resolution spatial detectors in cosmic ray experiments is described. A readout system was developed which uses a directly coupled, lumped element delay-line whose characteristics are independent of the MWPC design. A complete analysis of the delay-line and the readout electronic system shows that a spatial resolution of about 0.1 mm can be reached with the MWPC operating in the strictly proportional region. This was confirmed by measurements with a small MWPC and Fe-55 X-rays. A simplified analysis was carried out to estimate the theoretical limit of spatial resolution due to delta-rays, spread of the discharge along the anode wire, and inclined trajectories. To calculate the gas gain of MWPC's of different geometrical configurations a method was developed which is based on the knowledge of the first Townsend coefficient of the chamber gas.

  12. Age and area predict patterns of species richness in pumice rafts contingent on oceanic climatic zone encountered.

    Science.gov (United States)

    Velasquez, Eleanor; Bryan, Scott E; Ekins, Merrick; Cook, Alex G; Hurrey, Lucy; Firn, Jennifer

    2018-05-01

    The theory of island biogeography predicts that area and age explain species richness patterns (or alpha diversity) in insular habitats. Using a unique natural phenomenon, pumice rafting, we measured the influence of area, age, and oceanic climate on patterns of species richness. Pumice rafts are formed simultaneously when submarine volcanoes erupt, the pumice clasts breakup irregularly, forming irregularly shaped pumice stones which while floating through the ocean are colonized by marine biota. We analyze two eruption events and more than 5,000 pumice clasts collected from 29 sites and three climatic zones. Overall, the older and larger pumice clasts held more species. Pumice clasts arriving in tropical and subtropical climates showed this same trend, where in temperate locations species richness (alpha diversity) increased with area but decreased with age. Beta diversity analysis of the communities forming on pumice clasts that arrived in different climatic zones showed that tropical and subtropical clasts transported similar communities, while species composition on temperate clasts differed significantly from both tropical and subtropical arrivals. Using these thousands of insular habitats, we find strong evidence that area and age but also climatic conditions predict the fundamental dynamics of species richness colonizing pumice clasts.

  13. "The Oceans" not Withstanding: Scripps Geological-Geophysical Expeditions of the Golden Age

    Science.gov (United States)

    Fisher, R. L.

    2002-12-01

    "The Oceans: Their Physics, Chemistry, and General Biology," fully recognized and promoted the inherent unity of oceanography, the field itself, and of all components of the oceanic world. It covered well the wet pieces. However, except for sedimentary studies of the California borderland and reconnaissances of the Arctic, Mediterranean, and the South Atlantic, little was presented that could be parent to today's portrayals of marine geology and geophysics. The advances in those areas in the 1950's, 1960's, and early 1970's, by SIO scientists and those of several other institutions resulted from extended expeditionary studies, essential on-the-job field training of confident very young chief scientists, dogged pushing of traditional rough sampling methods to their limits, and the invention and lateral prompt application of precise electronic timing and sensing devices to shipboard observation of deep ocean seafloor/crustal elements. SIO's multifaceted expeditions of those years were conceived, planned and often lead by graduate students making thesis observations, assisted by their fellows as "warm bodies," perhaps with more senior staff scientists making specific collections at key localities. Education was real-time: discovering--reflection--discussion, and mutual tutoring. The principal factor that made such operation scientifically and educationally successful was SIO's then Director, Roger Revelle, a benevolent and trusting, but very perceptive, godfather.

  14. Uranium isotopic compositions of the crust and ocean: Age corrections, U budget and global extent of modern anoxia

    Science.gov (United States)

    Tissot, François L. H.; Dauphas, Nicolas

    2015-10-01

    the variability of the 238U/235U ratio on Pb-Pb and U-Pb ages and provide analytical formulas to calculate age corrections as a function of the age and isotopic composition of the sample. The crustal ratio may be used in calculation of Pb-Pb and U-Pb ages of continental crust rocks and minerals when the U isotopic composition is unknown. In cosmochemistry, the search for 247Cm (t1/2 = 15.6 Myr), an extinct short-lived radionuclide that decays into 235U, is important for understanding how r-process nuclides were synthesized in stars and learning about the astrophysical context of solar system formation (Chen and Wasserburg, 1981; Wasserburg et al., 1996; Nittler and Dauphas, 2006; Brennecka et al., 2010b; Tissot et al., 2015). In both terrestrial and extraterrestrial samples, variations in the 238U/235U ratio affect Pb-Pb ages (and depending on the analytical protocols, U-Pb ages). Therefore, samples dated by these techniques need to have their U isotopic compositions measured (Stirling et al., 2005, 2006; Weyer et al., 2008; Amelin et al., 2010; Brennecka et al., 2010b; Brennecka and Wadhwa, 2012; Connelly et al., 2012; Goldmann et al., 2015) or uncertainties on the U isotopic composition should be propagated into age calculations. In low temperature aqueous geochemistry, U isotopic fractionation between U4+ and U6+ (driven in part by nuclear field shift effects; Bigeleisen, 1996; Schauble, 2007; Abe et al., 2008), makes U isotopes potential tracers of paleoredox conditions (Montoya-Pino et al., 2010; Brennecka et al., 2011a; Kendall et al., 2013, 2015; Asael et al., 2013; Andersen et al., 2014; Dahl et al., 2014; Goto et al., 2014; Noordmann et al., 2015). The present paper aims at constraining some aspects of the global budget of uranium in the modern oceans using 238U/235U isotope variations, which involves characterizing the U isotopic composition of seawater and several reservoirs involved in the uranium oceanic budget. Uranium can exist in two oxidation states

  15. Restrictions and Proportionality

    DEFF Research Database (Denmark)

    Werlauff, Erik

    2009-01-01

    The article discusses three central aspects of the freedoms under European Community law, namely 1) the prohibition against restrictions as an important extension of the prohibition against discrimination, 2) a prohibition against exit restrictions which is just as important as the prohibition...... against host country restrictions, but which is often not recognised to the same extent by national law, and 3) the importance of also identifying and recognising an exit restriction, so that it is possible to achieve the required test of appropriateness and proportionality in relation to the rule...

  16. The divine proportion

    CERN Document Server

    Huntley, H E

    1970-01-01

    Using simple mathematical formulas, most as basic as Pythagoras's theorem and requiring only a very limited knowledge of mathematics, Professor Huntley explores the fascinating relationship between geometry and aesthetics. Poetry, patterns like Pascal's triangle, philosophy, psychology, music, and dozens of simple mathematical figures are enlisted to show that the ""divine proportion"" or ""golden ratio"" is a feature of geometry and analysis which awakes answering echoes in the human psyche. When we judge a work of art aesthetically satisfying, according to his formulation, we are making it c

  17. Hydrographic processing considerations in the “Big Data” age: An overview of technology trends in ocean and coastal surveys

    Science.gov (United States)

    Holland, M.; Hoggarth, A.; Nicholson, J.

    2016-04-01

    The quantity of information generated by survey sensors for ocean and coastal zone mapping has reached the “Big Data” age. This is influenced by the number of survey sensors available to conduct a survey, high data resolution, commercial availability, as well as an increased use of autonomous platforms. The number of users of sophisticated survey information is also growing with the increase in data volume. This is leading to a greater demand and broader use of the processed results, which includes marine archeology, disaster response, and many other applications. Data processing and exchange techniques are evolving to ensure this increased accuracy in acquired data meets the user demand, and leads to an improved understanding of the ocean environment. This includes the use of automated processing, models that maintain the best possible representation of varying resolution data to reduce duplication, as well as data plug-ins and interoperability standards. Through the adoption of interoperable standards, data can be exchanged between stakeholders and used many times in any GIS to support an even wider range of activities. The growing importance of Marine Spatial Data Infrastructure (MSDI) is also contributing to the increased access of marine information to support sustainable use of ocean and coastal environments. This paper offers an industry perspective on trends in hydrographic surveying and processing, and the increased use of marine spatial data.

  18. Proportion of Population Aged 65 or Older

    Data.gov (United States)

    U.S. Environmental Protection Agency — Variable was created as part of a set of indicators that demonstrate links between the condition of natural areas and human concerns and that quantify dependencies...

  19. A nuclear proportional counter

    International Nuclear Information System (INIS)

    1973-01-01

    The invention relates to a nuclear proportional counter comprising in a bulb filled with a low-pressure gas, a wire forming an anode and a cathode, characterized in that said cathode is constituted by two plane plates parallel to each other and to the anode wire, and in that two branches of a circuit are connected to the anode wire end-portions, each branch comprising a pre-amplifier, a measuring circuit consisting of a differentiator-integrator-differentiator amplifier and a zero detector, one of the branches comprising an adjustable delay circuit, both branches jointly attacking a conversion circuit for converting the pulse duration into amplitudes said conversion circuit being followed by a multi-channel analyzer, contingently provided with a recorder [fr

  20. Load proportional safety brake

    Science.gov (United States)

    Cacciola, M. J.

    1979-01-01

    This brake is a self-energizing mechanical friction brake and is intended for use in a rotary drive system. It incorporates a torque sensor which cuts power to the power unit on any overload condition. The brake is capable of driving against an opposing load or driving, paying-out, an aiding load in either direction of rotation. The brake also acts as a no-back device when torque is applied to the output shaft. The advantages of using this type of device are: (1) low frictional drag when driving; (2) smooth paying-out of an aiding load with no runaway danger; (3) energy absorption proportional to load; (4) no-back activates within a few degrees of output shaft rotation and resets automatically; and (5) built-in overload protection.

  1. Macroeconomic Proportions and Corellations

    Directory of Open Access Journals (Sweden)

    Constantin Anghelache

    2006-02-01

    Full Text Available The work is focusing on the main proportions and correlations which are being set up between the major macroeconomic indicators. This is the general frame for the analysis of the relations between the Gross Domestic Product growth rate and the unemployment rate; the interaction between the inflation rate and the unemployment rate; the connection between the GDP growth rate and the inflation rate. Within the analysis being performed, a particular attention is paid to �the basic relationship of the economic growth� by emphasizing the possibilities as to a factorial analysis of the macroeconomic development, mainly as far as the Gross Domestic Product is concerned. At this point, the authors are introducing the mathematical relations, which are used for modeling the macroeconomic correlations, hence the strictness of the analysis being performed.

  2. Macroeconomic Proportions and Corellations

    Directory of Open Access Journals (Sweden)

    Constantin Mitrut

    2006-04-01

    Full Text Available The work is focusing on the main proportions and correlations which are being set up between the major macroeconomic indicators. This is the general frame for the analysis of the relations between the Gross Domestic Product growth rate and the unemployment rate; the interaction between the inflation rate and the unemployment rate; the connection between the GDP growth rate and the inflation rate. Within the analysis being performed, a particular attention is paid to “the basic relationship of the economic growth” by emphasizing the possibilities as to a factorial analysis of the macroeconomic development, mainly as far as the Gross Domestic Product is concerned. At this point, the authors are introducing the mathematical relations, which are used for modeling the macroeconomic correlations, hence the strictness of the analysis being performed.

  3. Improved Access To Aging Ocean Basement Biosphere For Microbial Geochemical Studies

    Science.gov (United States)

    Cowen, J. P.; Glazer, B.; Rappe, M.; Kenig, F.; Fisher, A.; Copson, D.; Harris, D.; Jolly, J.; Nuzzio, D.

    2005-12-01

    CORK observatories affixed to Integrated Ocean Drilling Program (IODP) boreholes offer an unprecedented opportunity to study biogeochemical properties and microbial diversity in circulating fluids from sediment-buried ocean basement. Preliminary 16S rRNA gene sequence data from 65 degrees C fluids escaping from the top of the over-pressured ODP borehole 1026B, on the flanks of the Juan de Fuca Ridge indicated the presence of diverse Bacteria and Archaea, including gene clones with varying degrees of relatedness to known dissimilatory nitrate reducers (with ammonia production), thermophilic sulfate reducers, and thermophilic fermentative heterotrophs, consistent with fluid chemistry measurements. However, questions remain regarding microbial community structure, key metabolic pathways and rates, and redox chemistry of the basement fluids, along with concerns for contamination issues. We describe ongoing developments intended to address key in situ analytical and sampling challenges including: 1) The new generation CORKs' dedicated microbiological/geochemical fluid delivery system specifically designed to minimize chemical contamination and surface biofouling; and 2) Development of a seafloor instrument sled for coupling to the CORK's bio-fluid delivery system for acquisition of real-time, in situ electrochemical (voltammetry) redox chemistry data on basement fluids, in addition to in situ particle filtration of basement fluids for molecular genetics, culturing and biogeochemical studies. Results of the first deployment of this instrument sled to new CORK observatory 1301A in Cascadia Basin, on the flanks of the Juan de Fuca Ridge, will be described.

  4. Pharmacokinetics of marbofloxacin in pigs after intravenous and intramuscular administration of a single dose of 8 mg/kg: dose proportionality, influence of the age of the animals and urinary elimination.

    Science.gov (United States)

    Schneider, M; Paulin, A; Dron, F; Woehrlé, F

    2014-12-01

    The pharmacokinetics of marbofloxacin in pigs were evaluated as a function of dose and animal age following intravenous and intramuscular administration of a 16% solution (Forcyl(®) ). The absolute bioavailability of marbofloxacin as well as the dose proportionality was evaluated in 27-week-old fattening pigs. Blood PK and urinary excretion of marbofloxacin were evaluated after a single intramuscular dose of 8 mg/kg in 16-week-old male pigs. An additional group of 12-week-old weaned piglets was used for the evaluation of age-related kinetics. The plasma and urine concentration of marbofloxacin was determined using a HPLC method. Pharmacokinetic parameters were calculated using noncompartmental methods. After intravenous administration in 27-week-old fattening pigs, the total body clearance was 0.065 L/h·kg. After intramuscular administration to the same animals, the mean observed Cmax was 6.30 μg/mL, and the AUCINF was 115 μg·h/mL. The absolute bioavailability was 91.5%, and dose proportionality was shown within the dose range of 4-16 mg/kg. The renal clearance was about half of the value of the total clearance. The total systemic clearance values significantly decreased as a function of age, being 0.092 L/h·kg and 0.079 L/h·kg in pigs aged 12 and 16 weeks, respectively. © 2014 The Authors. Journal of Veterinary Pharmacology and Therapeutics Published by John Wiley & Sons Ltd.

  5. Worklife expectancy in a cohort of Danish employees aged 55-65 years - comparing a multi-state Cox proportional hazard approach with conventional multi-state life tables.

    Science.gov (United States)

    Pedersen, Jacob; Bjorner, Jakob Bue

    2017-11-15

    Work life expectancy (WLE) expresses the expected time a person will remain in the labor market until he or she retires. This paper compares a life table approach to estimating WLE to an approach based on multi-state proportional hazards models. The two methods are used to estimate WLE in Danish members and non-members of an early retirement pensioning (ERP) scheme according to levels of health. In 2008, data on self-rated health (SRH) was collected from 5212 employees 55-65 years of age. Data on previous and subsequent long-term sickness absence, unemployment, returning to work, and disability pension was collected from national registers. WLE was estimated from multi-state life tables and through multi-state models. Results from the multi-state model approach agreed with the life table approach but provided narrower confidence intervals for small groups. The shortest WLE was seen for employees with poor SRH and ERP membership while the longest WLE was seen for those with good SRH and no ERP membership. Employees aged 55-56 years with poor SRH but no ERP membership had shorter WLE than employees with good SRH and ERP membership. Relative WLE reversed for the two groups after age 57. At age 55, employees with poor SRH could be expected to spend approximately 12 months on long-term sick leave and 9-10 months unemployed before they retired - regardless of ERP membership. ERP members with poor SRH could be expected to spend 4.6 years working, while non-members could be expected to spend 7.1 years working. WLE estimated through multi-state models provided an effective way to summarize complex data on labor market affiliation. WLE differed noticeably between members and non-members of the ERP scheme. It has been hypothesized that while ERP membership would prompt some employees to retire earlier than they would have done otherwise, this effect would be partly offset by reduced time spent on long-term sick leave or unemployment. Our data showed no indication of

  6. Worklife expectancy in a cohort of Danish employees aged 55–65 years - comparing a multi-state Cox proportional hazard approach with conventional multi-state life tables

    Directory of Open Access Journals (Sweden)

    Jacob Pedersen

    2017-11-01

    Full Text Available Abstract Background Work life expectancy (WLE expresses the expected time a person will remain in the labor market until he or she retires. This paper compares a life table approach to estimating WLE to an approach based on multi-state proportional hazards models. The two methods are used to estimate WLE in Danish members and non-members of an early retirement pensioning (ERP scheme according to levels of health. Methods In 2008, data on self-rated health (SRH was collected from 5212 employees 55–65 years of age. Data on previous and subsequent long-term sickness absence, unemployment, returning to work, and disability pension was collected from national registers. WLE was estimated from multi-state life tables and through multi-state models. Results Results from the multi-state model approach agreed with the life table approach but provided narrower confidence intervals for small groups. The shortest WLE was seen for employees with poor SRH and ERP membership while the longest WLE was seen for those with good SRH and no ERP membership. Employees aged 55–56 years with poor SRH but no ERP membership had shorter WLE than employees with good SRH and ERP membership. Relative WLE reversed for the two groups after age 57. At age 55, employees with poor SRH could be expected to spend approximately 12 months on long-term sick leave and 9–10 months unemployed before they retired – regardless of ERP membership. ERP members with poor SRH could be expected to spend 4.6 years working, while non-members could be expected to spend 7.1 years working. Conclusion WLE estimated through multi-state models provided an effective way to summarize complex data on labor market affiliation. WLE differed noticeably between members and non-members of the ERP scheme. It has been hypothesized that while ERP membership would prompt some employees to retire earlier than they would have done otherwise, this effect would be partly offset by reduced time spent on

  7. Icon arrays help younger children's proportional reasoning.

    Science.gov (United States)

    Ruggeri, Azzurra; Vagharchakian, Laurianne; Xu, Fei

    2018-06-01

    We investigated the effects of two context variables, presentation format (icon arrays or numerical frequencies) and time limitation (limited or unlimited time), on the proportional reasoning abilities of children aged 7 and 10 years, as well as adults. Participants had to select, between two sets of tokens, the one that offered the highest likelihood of drawing a gold token, that is, the set of elements with the greater proportion of gold tokens. Results show that participants performed better in the unlimited time condition. Moreover, besides a general developmental improvement in accuracy, our results show that younger children performed better when proportions were presented as icon arrays, whereas older children and adults were similarly accurate in the two presentation format conditions. Statement of contribution What is already known on this subject? There is a developmental improvement in proportional reasoning accuracy. Icon arrays facilitate reasoning in adults with low numeracy. What does this study add? Participants were more accurate when they were given more time to make the proportional judgement. Younger children's proportional reasoning was more accurate when they were presented with icon arrays. Proportional reasoning abilities correlate with working memory, approximate number system, and subitizing skills. © 2018 The British Psychological Society.

  8. The atypical hydrodynamics of the Mayotte Lagoon (Indian Ocean): Effects on water age and potential impact on plankton productivity

    Science.gov (United States)

    Chevalier, C.; Devenon, J. L.; Pagano, M.; Rougier, G.; Blanchot, J.; Arfi, R.

    2017-09-01

    In mesotidal lagoons of the Indian Ocean, the coral reef barrier may be temporarily submerged at high tide and partially exposed at low tide, and this may cause unusual lagoon dynamics. A field measurement campaign was conducted in the north-east Mayotte Lagoon in order to understand these processes. An experimental approach was used, combining measurements taken by 1) a side-mounted Acoustic Doppler Current Profiler (ADCP) on a moving boat along transects through the reef passages (17 transects) and 2) by more conventional high-resolution moored ADCP measurements. A specific tidal analysis methodology was used to determine the spatial variability of the velocity. The tidal hydrodynamics within the lagoon were determined using a numerical model and then analyzed. The tide acted as a quasi-progressive forced wave in the lagoon: at low tide, water entered through the south passage, over the reef and left the lagoon through the north passage. This flow was reversed at high tide. The tide-driven quasi-progressive wave created a specific lagoon dynamics. Contrary to most other channel lagoons, the flow over the reef was mainly outward. This increases the inflow through the passages, which renews the water in the lagoon as shown by the indicators of age and origin of the water inside the lagoon. This study also showed the importance of these indicators for better understanding the variations and levels of plankton biomass (with chlorophyll concentration as proxy) which is quite high in this lagoon.

  9. Proportioning of light weight concrete

    DEFF Research Database (Denmark)

    Palmus, Lars

    1996-01-01

    Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory......Development of a method to determine the proportions of the raw materials in light weight concrete made with leight expanded clay aggregate. The method is based on composite theory...

  10. Proportional Symbol Mapping in R

    Directory of Open Access Journals (Sweden)

    Susumu Tanimura

    2006-01-01

    Full Text Available Visualization of spatial data on a map aids not only in data exploration but also in communication to impart spatial conception or ideas to others. Although recent carto-graphic functions in R are rapidly becoming richer, proportional symbol mapping, which is one of the common mapping approaches, has not been packaged thus far. Based on the theories of proportional symbol mapping developed in cartography, the authors developed some functions for proportional symbol mapping using R, including mathematical and perceptual scaling. An example of these functions demonstrated the new expressive power and options available in R, particularly for the visualization of conceptual point data.

  11. Optical fusions and proportional syntheses

    Science.gov (United States)

    Albert-Vanel, Michel

    2002-06-01

    A tragic error is being made in the literature concerning matters of color when dealing with optical fusions. They are still considered to be of additive nature, whereas experience shows us somewhat different results. The goal of this presentation is to show that fusions are, in fact, of 'proportional' nature, tending to be additive or subtractive, depending on each individual case. Using the pointillist paintings done in the manner of Seurat, or the spinning discs experiment could highlight this intermediate sector of the proportional. So, let us try to examine more closely what occurs in fact, by reviewing additive, subtractive and proportional syntheses.

  12. Cooling rates and the depth of detachment faulting at oceanic core complexes: Evidence from zircon Pb/U and (U-Th)/He ages

    Science.gov (United States)

    Grimes, Craig B.; Cheadle, Michael J.; John, Barbara E.; Reiners, P.W.; Wooden, J.L.

    2011-01-01

    Oceanic detachment faulting represents a distinct mode of seafloor spreading at slow spreading mid-ocean ridges, but many questions persist about the thermal evolution and depth of faulting. We present new Pb/U and (U-Th)/He zircon ages and combine them with magnetic anomaly ages to define the cooling histories of gabbroic crust exposed by oceanic detachment faults at three sites along the Mid-Atlantic Ridge (Ocean Drilling Program (ODP) holes 1270D and 1275D near the 15??20???N Transform, and Atlantis Massif at 30??N). Closure temperatures for the Pb/U (???800??C-850??C) and (U-Th)/He (???210??C) isotopic systems in zircon bracket acquisition of magnetic remanence, collectively providing a temperature-time history during faulting. Results indicate cooling to ???200??C in 0.3-0.5 Myr after zircon crystallization, recording time-averaged cooling rates of ???1000??C- 2000??C/Myr. Assuming the footwalls were denuded along single continuous faults, differences in Pb/U and (U-Th)/He zircon ages together with independently determined slip rates allow the distance between the ???850??C and ???200??C isotherms along the fault plane to be estimated. Calculated distances are 8.4 ?? 4.2 km and 5.0 2.1 km from holes 1275D and 1270D and 8.4 ?? 1.4 km at Atlantis Massif. Estimating an initial subsurface fault dip of 50 and a depth of 1.5 km to the 200??C isotherm leads to the prediction that the ???850??C isotherm lies ???5-7 km below seafloor at the time of faulting. These depth estimates for active fault systems are consistent with depths of microseismicity observed beneath the hypothesized detachment fault at the TAG hydrothermal field and high-temperature fault rocks recovered from many oceanic detachment faults. Copyright 2011 by the American Geophysical Union.

  13. Proportional counter end effects eliminator

    International Nuclear Information System (INIS)

    Meekins, J.F.

    1976-01-01

    An improved gas-filled proportional counter which includes a resistor network connected between the anode and cathode at the ends of the counter in order to eliminate ''end effects'' is described. 3 Claims, 2 Drawing Figures

  14. Electronics for proportional drift tubes

    International Nuclear Information System (INIS)

    Fremont, G.; Friend, B.; Mess, K.H.; Schmidt-Parzefall, W.; Tarle, J.C.; Verweij, H.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration); Geske, K.; Riege, H.; Schuett, J.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration); Semenov, Y.; CERN-Hamburg-Amsterdam-Rome-Moscow Collaboration)

    1980-01-01

    An electronic system for the read-out of a large number of proportional drift tubes (16,000) has been designed. This system measures deposited charge and drift-time of the charge of a particle traversing a proportional drift tube. A second event can be accepted during the read-out of the system. Up to 40 typical events can be collected and buffered before a data transfer to a computer is necessary. (orig.)

  15. Analogical proportions: another logical view

    Science.gov (United States)

    Prade, Henri; Richard, Gilles

    This paper investigates the logical formalization of a restricted form of analogical reasoning based on analogical proportions, i.e. statements of the form a is to b as c is to d. Starting from a naive set theoretic interpretation, we highlight the existence of two noticeable companion proportions: one states that a is to b the converse of what c is to d (reverse analogy), while the other called paralogical proportion expresses that what a and b have in common, c and d have it also. We identify the characteristic postulates of the three types of proportions and examine their consequences from an abstract viewpoint. We further study the properties of the set theoretic interpretation and of the Boolean logic interpretation, and we provide another light on the understanding of the role of permutations in the modeling of the three types of proportions. Finally, we address the use of these proportions as a basis for inference in a propositional setting, and relate it to more general schemes of analogical reasoning. The differences between analogy, reverse-analogy, and paralogy is still emphasized in a three-valued setting, which is also briefly presented.

  16. Response of a comprehensive climate model to a broad range of external forcings: relevance for deep ocean ventilation and the development of late Cenozoic ice ages

    Science.gov (United States)

    Galbraith, Eric; de Lavergne, Casimir

    2018-03-01

    Over the past few million years, the Earth descended from the relatively warm and stable climate of the Pliocene into the increasingly dramatic ice age cycles of the Pleistocene. The influences of orbital forcing and atmospheric CO2 on land-based ice sheets have long been considered as the key drivers of the ice ages, but less attention has been paid to their direct influences on the circulation of the deep ocean. Here we provide a broad view on the influences of CO2, orbital forcing and ice sheet size according to a comprehensive Earth system model, by integrating the model to equilibrium under 40 different combinations of the three external forcings. We find that the volume contribution of Antarctic (AABW) vs. North Atlantic (NADW) waters to the deep ocean varies widely among the simulations, and can be predicted from the difference between the surface densities at AABW and NADW deep water formation sites. Minima of both the AABW-NADW density difference and the AABW volume occur near interglacial CO2 (270-400 ppm). At low CO2, abundant formation and northward export of sea ice in the Southern Ocean contributes to very salty and dense Antarctic waters that dominate the global deep ocean. Furthermore, when the Earth is cold, low obliquity (i.e. a reduced tilt of Earth's rotational axis) enhances the Antarctic water volume by expanding sea ice further. At high CO2, AABW dominance is favoured due to relatively warm subpolar North Atlantic waters, with more dependence on precession. Meanwhile, a large Laurentide ice sheet steers atmospheric circulation as to strengthen the Atlantic Meridional Overturning Circulation, but cools the Southern Ocean remotely, enhancing Antarctic sea ice export and leading to very salty and expanded AABW. Together, these results suggest that a `sweet spot' of low CO2, low obliquity and relatively small ice sheets would have poised the AMOC for interruption, promoting Dansgaard-Oeschger-type abrupt change. The deep ocean temperature and

  17. Structural styles and zircon ages of the South Tianshan accretionary complex, Atbashi Ridge, Kyrgyzstan: Insights for the anatomy of ocean plate stratigraphy and accretionary processes

    Science.gov (United States)

    Sang, Miao; Xiao, Wenjiao; Orozbaev, Rustam; Bakirov, Apas; Sakiev, Kadyrbek; Pak, Nikolay; Ivleva, Elena; Zhou, Kefa; Ao, Songjian; Qiao, Qingqing; Zhang, Zhixin

    2018-03-01

    The anatomy of an ancient accretionary complex has a significance for a better understanding of the tectonic processes of accretionary orogens and complex because of its complicated compositions and strong deformation. With a thorough structural and geochronological study of a fossil accretionary complex in the Atbashi Ridge, South Tianshan (Kyrgyzstan), we analyze the structure and architecture of ocean plate stratigraphy in the western Central Asian Orogenic Belt. The architecture of the Atbashi accretionary complex is subdivisible into four lithotectonic assemblages, some of which are mélanges with "block-in-matrix" structure: (1) North Ophiolitic Mélange; (2) High-pressure (HP)/Ultra-high-pressure (UHP) Metamorphic Assemblage; (3) Coherent & Mélange Assemblage; and (4) South Ophiolitic Mélange. Relationships between main units are tectonic contacts presented by faults. The major structures and lithostratigraphy of these units are thrust-fold nappes, thrusted duplexes, and imbricated ocean plate stratigraphy. All these rock units are complicatedly stacked in 3-D with the HP/UHP rocks being obliquely southwestward extruded. Detrital zircon ages of meta-sediments provide robust constraints on their provenance from the Ili-Central Tianshan Arc. The isotopic ages of the youngest components of the four units are Late Permian, Early-Middle Triassic, Early Carboniferous, and Early Triassic, respectively. We present a new tectonic model of the South Tianshan; a general northward subduction polarity led to final closure of the South Tianshan Ocean in the End-Permian to Late Triassic. These results help to resolve the long-standing controversy regarding the subduction polarity and the timing of the final closure of the South Tianshan Ocean. Finally, our work sheds lights on the use of ocean plate stratigraphy in the analysis of the tectonic evolution of accretionary orogens.

  18. Development of multiwire proportional chambers

    CERN Multimedia

    Charpak, G

    1969-01-01

    It has happened quite often in the history of science that theoreticians, confronted with some major difficulty, have successfully gone back thirty years to look at ideas that had then been thrown overboard. But it is rare that experimentalists go back thirty years to look again at equipment which had become out-dated. This is what Charpak and his colleagues did to emerge with the 'multiwire proportional chamber' which has several new features making it a very useful addition to the armoury of particle detectors. In the 1930s, ion-chambers, Geiger- Muller counters and proportional counters, were vital pieces of equipment in nuclear physics research. Other types of detectors have since largely replaced them but now the proportional counter, in new array, is making a comeback.

  19. Bayesian inference on proportional elections.

    Directory of Open Access Journals (Sweden)

    Gabriel Hideki Vatanabe Brunello

    Full Text Available Polls for majoritarian voting systems usually show estimates of the percentage of votes for each candidate. However, proportional vote systems do not necessarily guarantee the candidate with the most percentage of votes will be elected. Thus, traditional methods used in majoritarian elections cannot be applied on proportional elections. In this context, the purpose of this paper was to perform a Bayesian inference on proportional elections considering the Brazilian system of seats distribution. More specifically, a methodology to answer the probability that a given party will have representation on the chamber of deputies was developed. Inferences were made on a Bayesian scenario using the Monte Carlo simulation technique, and the developed methodology was applied on data from the Brazilian elections for Members of the Legislative Assembly and Federal Chamber of Deputies in 2010. A performance rate was also presented to evaluate the efficiency of the methodology. Calculations and simulations were carried out using the free R statistical software.

  20. The Pacific Equatorial Age Transect, IODP Expeditions 320 and 321: Building a 50-Million-Year-Long Environmental Record of the Equatorial Pacific Ocean

    Directory of Open Access Journals (Sweden)

    Kusali Gamage

    2010-04-01

    Full Text Available In March 2009, the R/V JOIDES Resolution returned to operations after its extended refit and began with a drilling program ideally suited to its drilling strengths, the Pacific Equatorial Age Transect (PEAT, IODP Exp 320/321; Fig. 1A. The PEAT drilling program was developed to understand how a major oceanic region evolved over the Cenozoic Era(65–0 Ma and how it interacted with global climate. It specifically targeted the interval between 52 Ma and 0 Ma and drilled a series of sites that originated on the paleoequator. These sites have since been moved to the northwest by plate tectonics.The equatorial Pacific is an important target for paleocean ographic study because it is a significant ‘cog’ in the Earth’s climate machine, representing roughly half of the total tropical oceans that in turn represent roughly half of the total global ocean area. Prior drilling in both the Deep Sea Drilling Project (DSDP and the Ocean Drilling Program (ODP outlined the changes that have occurred through the Cenozoic (e.g., van Andel et al., 1975; Pisias et al., 1995. Not only did the earlier work fail to cover sufficient timeintervals but also many of the sites were cored with ‘first-generation’ scientific drilling technology with incomplete and disturbed sediment recovery and thus cannot be used for detailed studies.

  1. Multistate cohort models with proportional transfer rates

    DEFF Research Database (Denmark)

    Schoen, Robert; Canudas-Romo, Vladimir

    2006-01-01

    of transfer rates. The two living state case and hierarchical multistate models with any number of living states are analyzed in detail. Applying our approach to 1997 U.S. fertility data, we find that observed rates of parity progression are roughly proportional over age. Our proportional transfer rate...... approach provides trajectories by parity state and facilitates analyses of the implications of changes in parity rate levels and patterns. More women complete childbearing at parity 2 than at any other parity, and parity 2 would be the modal parity in models with total fertility rates (TFRs) of 1.40 to 2......We present a new, broadly applicable approach to summarizing the behavior of a cohort as it moves through a variety of statuses (or states). The approach is based on the assumption that all rates of transfer maintain a constant ratio to one another over age. We present closed-form expressions...

  2. Saving Money Using Proportional Reasoning

    Science.gov (United States)

    de la Cruz, Jessica A.; Garney, Sandra

    2016-01-01

    It is beneficial for students to discover intuitive strategies, as opposed to the teacher presenting strategies to them. Certain proportional reasoning tasks are more likely to elicit intuitive strategies than other tasks. The strategies that students are apt to use when approaching a task, as well as the likelihood of a student's success or…

  3. Deep Ocean Mineral Supplementation Enhances the Cerebral Hemodynamic Response during Exercise and Decreases Inflammation Postexercise in Men at Two Age Levels

    Directory of Open Access Journals (Sweden)

    Ching-Yin Wei

    2017-12-01

    Full Text Available Background: Previous studies have consistently shown that oral supplementation of deep ocean minerals (DOM improves vascular function in animals and enhances muscle power output in exercising humans.Purpose: To examine the effects of DOM supplementation on the cerebral hemodynamic response during physical exertion in young and middle-aged men.Design: Double-blind placebo-controlled crossover studies were conducted in young (N = 12, aged 21.2 ± 0.4 years and middle-aged men (N = 9, aged 46.8 ± 1.4 years. The counter-balanced trials of DOM and Placebo were separated by a 2-week washout period. DOM and Placebo were orally supplemented in drinks before, during, and after cycling exercise. DOM comprises desalinated minerals and trace elements from seawater collected ~618 m below the earth's surface.Methods: Cerebral hemodynamic response (tissue hemoglobin was measured during cycling at 75% VO2max using near infrared spectroscopy (NIRS.Results: Cycling time to exhaustion at 75% VO2max and the associated plasma lactate response were similar between the Placebo and DOM trials for both age groups. In contrast, DOM significantly elevated cerebral hemoglobin levels in young men and, to a greater extent, in middle-aged men compared with Placebo. An increased neutrophil to lymphocyte ratio (NLR was observed in middle-aged men, 2 h after exhaustive cycling, but was attenuated by DOM.Conclusion: Our data suggest that minerals and trace elements from deep oceans possess great promise in developing supplements to increase the cerebral hemodynamic response against a physical challenge and during post-exercise recovery for middle-aged men.

  4. Disease proportions attributable to environment

    Directory of Open Access Journals (Sweden)

    Vineis Paolo

    2007-11-01

    Full Text Available Abstract Population disease proportions attributable to various causal agents are popular as they present a simplified view of the contribution of each agent to the disease load. However they are only summary figures that may be easily misinterpreted or over-interpreted even when the causal link between an exposure and an effect is well established. This commentary discusses several issues surrounding the estimation of attributable proportions, particularly with reference to environmental causes of cancers, and critically examines two recently published papers. These issues encompass potential biases as well as the very definition of environment and of environmental agent. The latter aspect is not just a semantic question but carries implications for the focus of preventive actions, whether centred on the material and social environment or on single individuals.

  5. PEP quark search proportional chambers

    Energy Technology Data Exchange (ETDEWEB)

    Parker, S I; Harris, F; Karliner, I; Yount, D [Hawaii Univ., Honolulu (USA); Ely, R; Hamilton, R; Pun, T [California Univ., Berkeley (USA). Lawrence Berkeley Lab.; Guryn, W; Miller, D; Fries, R [Northwestern Univ., Evanston, IL (USA)

    1981-04-01

    Proportional chambers are used in the PEP Free Quark Search to identify and remove possible background sources such as particles traversing the edges of counters, to permit geometric corrections to the dE/dx and TOF information from the scintillator and Cerenkov counters, and to look for possible high cross section quarks. The present beam pipe has a thickness of 0.007 interaction lengths (lambdasub(i)) and is followed in both arms each with 45/sup 0/ <= theta <= 135/sup 0/, ..delta..phi=90/sup 0/ by 5 proportional chambers, each 0.0008 lambdasub(i) thick with 32 channels of pulse height readout, and by 3 thin scintillator planes, each 0.003 lambdasub(i) thick. Following this thin front end, each arm of the detector has 8 layers of scintillator (one with scintillating light pipes) interspersed with 4 proportional chambers and a layer of lucite Cerenkov counters. Both the calculated ion statistics and measurements using He-CH/sub 4/ gas in a test chamber indicate that the chamber efficiencies should be >98% for q=1/3. The Landau spread measured in the test was equal to that observed for normal q=1 traversals. One scintillator plane and thin chamber in each arm will have an extra set of ADC's with a wide gate bracketing the normal one so timing errors and tails of earlier pulses should not produce fake quarks.

  6. Age and microfacies of oceanic Upper Triassic radiolarite components from the Middle Jurassic ophiolitic mélange in the Zlatibor Mountains (Inner Dinarides, Serbia and their provenance

    Directory of Open Access Journals (Sweden)

    Gawlick Hans-Jürgen

    2017-08-01

    Full Text Available Oceanic radiolarite components from the Middle Jurassic ophiolitic mélange between Trnava and Rožanstvo in the Zlatibor Mountains (Dinaridic Ophiolite Belt west of the Drina–Ivanjica unit yield Late Triassic radiolarian ages. The microfacies characteristics of the radiolarites show pure ribbon radiolarites without crinoids or thin-shelled bivalves. Beside their age and the preservation of the radiolarians this points to a deposition of the radiolarites on top of the oceanic crust of the Neo-Tethys, which started to open in the Late Anisian. South of the study area the ophiolitic mélange (Gostilje–Ljubiš–Visoka–Radoševo mélange contains a mixture of blocks of 1 oceanic crust, 2 Middle and Upper Triassic ribbon radiolarites, and 3 open marine limestones from the continental slope. On the basis of this composition we can conclude that the Upper Triassic radiolarite clasts derive either from 1 the younger parts of the sedimentary succession above the oceanic crust near the continental slope or, more convincingly 2 the sedimentary cover of ophiolites in a higher nappe position, because Upper Triassic ribbon radiolarites are only expected in more distal oceanic areas. The ophiolitic mélange in the study area overlies different carbonate blocks of an underlying carbonate-clastic mélange (Sirogojno mélange. We date and describe three localities with different Upper Triassic radiolarite clasts in a mélange, which occurs A on top of Upper Triassic fore-reef to reefal limestones (Dachstein reef, B between an Upper Triassic reefal limestone block and a Lower Carnian reef limestone (Wetterstein reef, and C in fissures of an Upper Triassic lagoonal to back-reef limestone (Dachstein lagoon. The sedimentary features point to a sedimentary and not to a tectonic emplacement of the ophiolitic mélange (= sedimentary mélange filling the rough topography of the topmost carbonate-clastic mélange below. The block spectrum of the underlying and

  7. Age and microfacies of oceanic Upper Triassic radiolarite components from the Middle Jurassic ophiolitic mélange in the Zlatibor Mountains (Inner Dinarides, Serbia) and their provenance

    Science.gov (United States)

    Gawlick, Hans-Jürgen; Djerić, Nevenka; Missoni, Sigrid; Bragin, Nikita Yu.; Lein, Richard; Sudar, Milan; Jovanović, Divna

    2017-08-01

    Oceanic radiolarite components from the Middle Jurassic ophiolitic mélange between Trnava and Rožanstvo in the Zlatibor Mountains (Dinaridic Ophiolite Belt) west of the Drina-Ivanjica unit yield Late Triassic radiolarian ages. The microfacies characteristics of the radiolarites show pure ribbon radiolarites without crinoids or thin-shelled bivalves. Beside their age and the preservation of the radiolarians this points to a deposition of the radiolarites on top of the oceanic crust of the Neo-Tethys, which started to open in the Late Anisian. South of the study area the ophiolitic mélange (Gostilje-Ljubiš-Visoka-Radoševo mélange) contains a mixture of blocks of 1) oceanic crust, 2) Middle and Upper Triassic ribbon radiolarites, and 3) open marine limestones from the continental slope. On the basis of this composition we can conclude that the Upper Triassic radiolarite clasts derive either from 1) the younger parts of the sedimentary succession above the oceanic crust near the continental slope or, more convincingly 2) the sedimentary cover of ophiolites in a higher nappe position, because Upper Triassic ribbon radiolarites are only expected in more distal oceanic areas. The ophiolitic mélange in the study area overlies different carbonate blocks of an underlying carbonate-clastic mélange (Sirogojno mélange). We date and describe three localities with different Upper Triassic radiolarite clasts in a mélange, which occurs A) on top of Upper Triassic fore-reef to reefal limestones (Dachstein reef), B) between an Upper Triassic reefal limestone block and a Lower Carnian reef limestone (Wetterstein reef), and C) in fissures of an Upper Triassic lagoonal to back-reef limestone (Dachstein lagoon). The sedimentary features point to a sedimentary and not to a tectonic emplacement of the ophiolitic mélange (= sedimentary mélange) filling the rough topography of the topmost carbonate-clastic mélange below. The block spectrum of the underlying and slightly older

  8. Incisors’ proportions in smile esthetics

    Science.gov (United States)

    Alsulaimani, Fahad F; Batwa, Waeil

    2013-01-01

    Aims: To determine whether alteration of the maxillary central and lateral incisors’ length and width, respectively, would affect perceived smile esthetics and to validate the most esthetic length and width, respectively, for the central and lateral incisors. Materials and Methods: Photographic manipulation was undertaken to produce two sets of photographs, each set of four photographs showing the altered width of the lateral incisor and length of the central length. The eight produced photographs were assessed by laypeople, dentists and orthodontists. Results: Alteration in the incisors’ proportion affected the relative smile attractiveness for laypeople (n=124), dentists (n=115) and orthodontists (n=68); dentists and orthodontists did not accept lateral width reduction of more than 0.5 mm (P<0.01), which suggests that the lateral to central incisor width ratio ranges from 54% to 62%. However, laypeople did not accept lateral width reduction of more than 1 mm (P<0.01), widening the range to be from 48% to 62%. All groups had zero tolerance for changes in central crown length (P<0.01). Conclusion: All participants recognized that the central incisors’ length changes. For lateral incisors, laypeople were more tolerant than dentists and orthodontists. This suggests that changing incisors’ proportions affects the relative smile attractiveness. PMID:24987650

  9. Constant Proportion Debt Obligations (CPDOs)

    DEFF Research Database (Denmark)

    Cont, Rama; Jessen, Cathrine

    2012-01-01

    be made arbitrarily small—and thus the credit rating arbitrarily high—by increasing leverage, but the ratings obtained strongly depend on assumptions on the credit environment (high spread or low spread). More importantly, CPDO loss distributions are found to exhibit a wide range of tail risk measures......Constant Proportion Debt Obligations (CPDOs) are structured credit derivatives that generate high coupon payments by dynamically leveraging a position in an underlying portfolio of investment-grade index default swaps. CPDO coupons and principal notes received high initial credit ratings from...... the major rating agencies, based on complex models for the joint transition of ratings and spreads for all names in the underlying portfolio. We propose a parsimonious model for analysing the performance of CPDO strategies using a top-down approach that captures the essential risk factors of the CPDO. Our...

  10. Precambrian U-Pb zircon ages in eclogites and garnet pyroxenites from South Brittany (France): an old oceanic crust in the West European Hercynian belt?

    Science.gov (United States)

    Peucat, J. J.; Vidal, Ph.; Godard, G.; Postaire, B.

    1982-08-01

    U-Pb zircon ages have been determined for two eclogites from the Vendée and for two garnet pyroxenites from the Baie d'Audierne. In an episodic Pb loss model, the two discordia would give upper intercept ages around 1300-1250 Ma and lower intercepts ages of 436-384 Ma. Two interpretations are proposed: (1) The 1250-1300 Ma ages may reflect an unspecified upper mantle event or process; the Paleozoic ages correspond to the tectonic emplacement of an eclogitic mantle fragment into the continental crust. (2) The protolith may have been extracted from the upper mantle 1250-1300 Ma ago and stored in a crustal environment until it was metamorphosed under high-pressure conditions around 400 Ma ago. This latter model is favoured by available geologic and isotopic data. Consequently, we propose that a 1300 Ma old oceanic crust was tectonicly incorporated into a sialic basement during the Proterozoic. This mixture was subsequently subducted during the Paleozoic.

  11. Position-sensitive proportional counter

    International Nuclear Information System (INIS)

    Kopp, M.K.

    1980-01-01

    A position-sensitive proportional counter circuit uses a conventional (low-resistance, metal-wire anode) counter for spatial resolution of an ionizing event along the anode, which functions as an RC line. A pair of preamplifiers at the anode ends act as stabilized active-capacitance loads, each comprising a series-feedback, low-noise amplifier and a unity-gain, shunt-feedback amplifier whose output is connected through a feedback capacitor to the series-feedback amplifier input. The stabilized capacitance loading of the anode allows distributed RC-line position encoding and subsequent time difference decoding by sensing the difference in rise times of pulses at the anode ends where the difference is primarily in response to the distributed capacitance along the anode. This allows the use of lower resistance wire anodes for spatial radiation detection which simplifies the counter construction of handling of the anodes, and stabilizes the anode resistivity at high count rates (>10 6 counts/sec). (author)

  12. The 3.6 ka Aniakchak tephra in the Arctic Ocean: a constraint on the Holocene radiocarbon reservoir age in the Chukchi Sea

    Science.gov (United States)

    Pearce, Christof; Varhelyi, Aron; Wastegård, Stefan; Muschitiello, Francesco; Barrientos, Natalia; O'Regan, Matt; Cronin, Thomas M.; Gemery, Laura; Semiletov, Igor; Backman, Jan; Jakobsson, Martin

    2017-04-01

    The caldera-forming eruption of the Aniakchak volcano in the Aleutian Range on the Alaskan Peninsula at 3.6 cal kyr BP was one of the largest Holocene eruptions worldwide. The resulting ash is found as a visible sediment layer in several Alaskan sites and as a cryptotephra on Newfoundland and Greenland. This large geographic distribution, combined with the fact that the eruption is relatively well constrained in time using radiocarbon dating of lake sediments and annual layer counts in ice cores, makes it an excellent stratigraphic marker for dating and correlating mid-late Holocene sediment and paleoclimate records. This study presents the outcome of a targeted search for the Aniakchak tephra in a marine sediment core from the Arctic Ocean, namely Core SWERUS-L2-2-PC1 (2PC), raised from 57 m water depth in Herald Canyon, western Chukchi Sea. High concentrations of tephra shards, with a geochemical signature matching that of Aniakchak ash, were observed across a more than 1.5 m long sediment sequence. Since the primary input of volcanic ash is through atmospheric transport, and assuming that bioturbation can account for mixing up to ca. 10 cm of the marine sediment deposited at the coring site, the broad signal is interpreted as sustained reworking at the sediment source input. The isochron is therefore placed at the base of the sudden increase in tephra concentrations rather than at the maximum concentration. This interpretation of major reworking is strengthened by analysis of grain size distribution which points to ice rafting as an important secondary transport mechanism of volcanic ash. Combined with radiocarbon dates on mollusks in the same sediment core, the volcanic marker is used to calculate a marine radiocarbon reservoir age offset ΔR = 477 ± 60 years. This relatively high value may be explained by the major influence of typically carbon-old Pacific waters, and it agrees well with recent estimates of ΔR along the northwest Alaskan coast, possibly

  13. Old moms with new tricks: modeling the effects of age-specific spawning behaviors in Pacific Ocean perch

    Science.gov (United States)

    In commercially exploited, long-lived fish species, age structure plays an important role in determining population stability and resilience to human and environmental impacts. The often observed increase in energy allocation per offspring by older females can improve larval surv...

  14. Ocean Acidification | Smithsonian Ocean Portal

    Science.gov (United States)

    Natural History Blog For Educators At The Museum Media Archive Ocean Life & Ecosystems Mammals Sharks Mangroves Poles Census of Marine Life Planet Ocean Tides & Currents Waves & Storms The Seafloor ocean is affected. Such a relatively quick change in ocean chemistry doesn't give marine life, which

  15. Variability of the geothermal gradient across two differently aged magma-rich continental rifted margins of the Atlantic Ocean

    OpenAIRE

    Gholamrezaie, Ershad; Scheck-Wenderoth, Magdalena (Dr.); Sippel, Judith (Dr.); Strecker, Manfred R. (Prof. Dr.)

    2018-01-01

    Abstract. The aim of this study is to investigate the shallow thermal field differences for two differently aged passive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously published 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive margins. These 3-D models differentiate various sedimentary, crustal, and mantle units and i...

  16. Global Drought Proportional Economic Loss Risk Deciles

    Data.gov (United States)

    National Aeronautics and Space Administration — Global Drought Proportional Economic Loss Risk Deciles is a 2.5 minute grid of drought hazard economic loss as proportions of Gross Domestic Product (GDP) per...

  17. Impossibility Theorem in Proportional Representation Problem

    International Nuclear Information System (INIS)

    Karpov, Alexander

    2010-01-01

    The study examines general axiomatics of Balinski and Young and analyzes existed proportional representation methods using this approach. The second part of the paper provides new axiomatics based on rational choice models. New system of axioms is applied to study known proportional representation systems. It is shown that there is no proportional representation method satisfying a minimal set of the axioms (monotonicity and neutrality).

  18. Cognitive and Metacognitive Aspects of Proportional Reasoning

    Science.gov (United States)

    Modestou, Modestina; Gagatsis, Athanasios

    2010-01-01

    In this study we attempt to propose a new model of proportional reasoning based both on bibliographical and research data. This is impelled with the help of three written tests involving analogical, proportional, and non-proportional situations that were administered to pupils from grade 7 to 9. The results suggest the existence of a…

  19. Evaluating Middle Years Students' Proportional Reasoning

    Science.gov (United States)

    Hilton, Annette; Dole, Shelley; Hilton, Geoff; Goos, Merrilyn; O'Brien, Mia

    2012-01-01

    Proportional reasoning is a key aspect of numeracy that is not always developed naturally by students. Understanding the types of proportional reasoning that students apply to different problem types is a useful first step to identifying ways to support teachers and students to develop proportional reasoning in the classroom. This paper describes…

  20. Moving beyond the age-depth model paradigm in deep sea palaeoclimate archives: dual radiocarbon and stable isotope analysis on single foraminifera

    NARCIS (Netherlands)

    Lougheed, Bryan C.; Metcalfe, Brett; Ninnemann, Ulysses S.; Wacker, Lukas

    2017-01-01

    Late-glacial palaeoclimate reconstructions from deep-sea sediment archives provide valuable insight into past rapid changes in ocean chemistry, but only a small proportion of the ocean floor is suitable for such reconstructions using the existing state-of-the-art using the age-depth approach. We

  1. Ocean tides

    Science.gov (United States)

    Hendershott, M. C.

    1975-01-01

    A review of recent developments in the study of ocean tides and related phenomena is presented. Topics briefly discussed include: the mechanism by which tidal dissipation occurs; continental shelf, marginal sea, and baroclinic tides; estimation of the amount of energy stored in the tide; the distribution of energy over the ocean; the resonant frequencies and Q factors of oceanic normal modes; the relationship of earth tides and ocean tides; and numerical global tidal models.

  2. Proportioning of U3O8 powder

    International Nuclear Information System (INIS)

    Cermak, V.; Markvart, M.; Novy, P.; Vanka, M.

    1989-01-01

    The tests are briefly described or proportioning U 3 O 8 powder of a granulometric grain size range of 0-160 μm using a vertical screw, a horizontal dual screw and a vibration dispenser with a view to proportioning very fine U 3 O 8 powder fractions produced in the oxidation of UO 2 fuel pellets. In the tests, the evenness of proportioning was assessed by the percentage value of the proportioning rate spread measured at one-minute intervals at a proportioning rate of 1-3 kg/h. In feeding the U 3 O 3 in a flame fluorator, it is advantageous to monitor the continuity of the powder column being proportioned and to assess it radiometrically by the value of the proportioning rate spread at very short intervals (0.1 s). (author). 10 figs., 1 tab., 12 refs

  3. Body physique and proportionality of Brazilian female artistic gymnasts.

    Science.gov (United States)

    Bacciotti, Sarita; Baxter-Jones, Adam; Gaya, Adroaldo; Maia, José

    2018-04-01

    This study aimed to identify physique characteristics (anthropometry, somatotype, body proportionality) of Brazilian female artistic gymnasts, and to compare them across competitive levels (sub-elite versus non-elite) within competitive age-categories. Two hundred forty-nine female gymnasts (68 sub-elite; 181 non-elite) from 26 Brazilian gymnastics clubs, aged 9-20 years and split into four age-categories, were sampled. Gymnasts were assessed for 16 anthropometric traits (height, weight, lengths, widths, girths, and skinfolds); somatotype was determined according to Heath-Carter method, body fat was estimated by bioimpedance, and proportionality was computed based on the z-phantom strategy. Non-elite and sub-elite gymnasts had similar values in anthropometric characteristics, however non-elite had higher fat folds in all age-categories (P < 0.01). In general, mesomorphy was the salient somatotype component in all age-categories, and an increase in endomorphy, followed by a decrease in ectomorphy across age was observed. Regarding proportionality, profile similarity was found between sub-elite and non-elite within age-categories. In conclusion results suggest the presence of a typical gymnast's physical prototype across age and competitive level, which can be useful to coaches during their selection processes in clubs and regional/national teams.

  4. Variability of the geothermal gradient across two differently aged magma-rich continental rifted margins of the Atlantic Ocean: the Southwest African and the Norwegian margins

    Directory of Open Access Journals (Sweden)

    E. Gholamrezaie

    2018-02-01

    Full Text Available The aim of this study is to investigate the shallow thermal field differences for two differently aged passive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously published 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive margins. These 3-D models differentiate various sedimentary, crustal, and mantle units and integrate different geophysical data such as seismic observations and the gravity field. We extracted the temperature–depth distributions in 1 km intervals down to 6 km below the upper thermal boundary condition. The geothermal gradient was then calculated for these intervals between the upper thermal boundary condition and the respective depth levels (1, 2, 3, 4, 5, and 6 km below the upper thermal boundary condition. According to our results, the geothermal gradient decreases with increasing depth and shows varying lateral trends and values for these two different margins. We compare the 3-D geological structural models and the geothermal gradient variations for both thermal models and show how radiogenic heat production, sediment insulating effect, and thermal lithosphere–asthenosphere boundary (LAB depth influence the shallow thermal field pattern. The results indicate an ongoing process of oceanic mantle cooling at the young Norwegian margin compared with the old SW African passive margin that seems to be thermally equilibrated in the present day.

  5. Variability of the geothermal gradient across two differently aged magma-rich continental rifted margins of the Atlantic Ocean: the Southwest African and the Norwegian margins

    Science.gov (United States)

    Gholamrezaie, Ershad; Scheck-Wenderoth, Magdalena; Sippel, Judith; Strecker, Manfred R.

    2018-02-01

    The aim of this study is to investigate the shallow thermal field differences for two differently aged passive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously published 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive margins. These 3-D models differentiate various sedimentary, crustal, and mantle units and integrate different geophysical data such as seismic observations and the gravity field. We extracted the temperature-depth distributions in 1 km intervals down to 6 km below the upper thermal boundary condition. The geothermal gradient was then calculated for these intervals between the upper thermal boundary condition and the respective depth levels (1, 2, 3, 4, 5, and 6 km below the upper thermal boundary condition). According to our results, the geothermal gradient decreases with increasing depth and shows varying lateral trends and values for these two different margins. We compare the 3-D geological structural models and the geothermal gradient variations for both thermal models and show how radiogenic heat production, sediment insulating effect, and thermal lithosphere-asthenosphere boundary (LAB) depth influence the shallow thermal field pattern. The results indicate an ongoing process of oceanic mantle cooling at the young Norwegian margin compared with the old SW African passive margin that seems to be thermally equilibrated in the present day.

  6. Why do card issuers charge proportional fees?

    OpenAIRE

    Oz Shy; Zhu Wang

    2008-01-01

    This paper explains why payment card companies charge consumers and merchants fees which are proportional to the transaction values instead of charging a fixed per-transaction fee. Our theory shows that, even in the absence of any cost considerations, card companies earn much higher profit when they charge proportional fees. It is also shown that competition among merchants reduces card companies' gains from using proportional fees relative to a fixed per-transaction fee. Merchants are found ...

  7. Age

    Science.gov (United States)

    ... adults? How can you reduce anesthesia risks in older patients? Age Age may bring wisdom but it also brings ... Ask your physician to conduct a pre-surgery cognitive test — an assessment of your mental function. The physician can use the results as a ...

  8. Environmental drivers of sapwood and heartwood proportions

    Science.gov (United States)

    Thurner, Martin; Beer, Christian

    2017-04-01

    Recent advances combining information on stem volume from remote sensing with allometric relationships derived from forest inventory databases have led to spatially continuous estimates of stem, branch, root and foliage biomass in northern boreal and temperate forests. However, a separation of stem biomass into sapwood and heartwood mass has remained unsolved, despite their important differences in biogeochemical function, for instance concerning their contribution to tree respiratory costs. Although relationships between sapwood cross-sectional area and supported leaf area are well established, less is known about relations between sapwood or heartwood mass and other traits (e.g. stem mass), since these biomass compartments are more difficult to measure in practice. Here we investigate the variability in sapwood and heartwood proportions and determining environmental factors. For this task we explore an available biomass and allometry database (BAAD) and study relative sapwood and heartwood area, volume, mass and density in dependence of tree species, age and climate. First, a theoretical framework on how to estimate sap- and heartwood mass from stem mass is developed. Subsequently, the underlying assumptions and relationships are explored with the help of the BAAD. The established relationships can be used to derive spatially continuous sapwood and heartwood mass estimates by applying them to remote sensing based stem volume products. This would be a fundamental step forward to a data-driven estimate of autotrophic respiration.

  9. Relating arithmetical techniques of proportion to geometry

    DEFF Research Database (Denmark)

    Wijayanti, Dyana

    2015-01-01

    The purpose of this study is to investigate how textbooks introduce and treat the theme of proportion in geometry (similarity) and arithmetic (ratio and proportion), and how these themes are linked to each other in the books. To pursue this aim, we use the anthropological theory of the didactic....... Considering 6 common Indonesian textbooks in use, we describe how proportion is explained and appears in examples and exercises, using an explicit reference model of the mathematical organizations of both themes. We also identify how the proportion themes of the geometry and arithmetic domains are linked. Our...

  10. Aging

    International Nuclear Information System (INIS)

    Sasaki, Hideo; Kodama, Kazunori; Yamada, Michiko

    1991-01-01

    The hypothesis that exposure to ionizing radiation accelerates the aging process has been actively investigated at ABCC-RERF since 1958, when longitudinal cohort studies of the Adult Health Study (AHS) and the Life Span Study (LSS) were initiated. In their 1975 overall review of aging studies related to the atomic bomb (A-bomb) survivors, Finch and Beebe concluded that while most studies had shown no correlation between aging and radiation exposure, they had not involved the large numbers of subjects required to provide strong evidence for or against the hypothesis. Extending LSS mortality data up to 1978 did not alter the earlier conclusion that any observed life-shortening was associated primarily with cancer induction rather than with any nonspecific cause. The results of aging studies conducted during the intervening 15 years using data from the same populations are reviewed in the present paper. Using clinical, epidemiological, and laboratory techniques, a broad spectrum of aging parameters have been studied, such as postmortem morphological changes, tests of functional capacity, physical tests and measurements, laboratory tests, tissue changes, and morbidity. With respect to the aging process, the overall results have not been consistent and are generally thought to show no relation to radiation exposure. Although some preliminary results suggest a possible radiation-induced increase in atherosclerotic diseases and acceleration of aging in the T-cell-related immune system, further study is necessary to confirm these findings. In the future, applying the latest gerontological study techniques to data collected from subjects exposed 45 years ago to A-bomb radiation at relatively young ages will present a new body of data relevant to the study of late radiation effects. (author) 103 refs

  11. Oceanic archipelagos

    DEFF Research Database (Denmark)

    Triantis, Kostas A.; Whittaker, Robert James; Fernández-Palacios, José María

    2016-01-01

    Since the contributions of Charles Darwin and Alfred Russel Wallace, oceanic archipelagos have played a central role in the development of biogeography. However, despite the critical influence of oceanic islands on ecological and evolutionary theory, our focus has remained limited to either the i...... of the archipelagic geological dynamics that can affect diversity at both the island and the archipelagic level. We also reaffirm that oceanic archipelagos are appropriate spatiotemporal units to frame analyses in order to understand large scale patterns of biodiversity....

  12. Aging

    International Nuclear Information System (INIS)

    Finch, S.C.; Beebe, G.W.

    1975-01-01

    The hypothesis that ionizing radiation accelerates natural aging has been under investigation at the Atomic Bomb Casualty Commission since 1959. Postmortem observations of morphologic and chemical changes, tests of functional capacity, physical tests and measurements, clinical laboratory tests, tissue changes, morbidity, and mortality have all been examined by ABCC investigators interested in this hypothesis. These studies have been beset with conceptual difficulties centered on the definition and measurement of aging. An empirical approach early led to the calculation of an index of physiologic age as a linear combination of age-related tests of various organ systems. Most studies have been negative but have not involved the large numbers that might be required to provide strong evidence for or against the hypothesis. Mortality, however, has been examined on the basis of a large sample and over the period 1950-1972 had provided no support for the hypothesis of radiation-accelerated aging. Ionizing radiation dose, of course shorten human life, but its life-shortening effect appears to be the result of specific radiation-induced disease, especially neoplasms. The hypothesis is now much less attractive than it was 10-20 years ago but still has some value in stimulating research on aging. The experience of the A-bomb survivors provides an unusual opportunity for a definitive test of the hypothesis. (auth.)

  13. Proportional Reasoning and the Visually Impaired

    Science.gov (United States)

    Hilton, Geoff; Hilton, Annette; Dole, Shelley L.; Goos, Merrilyn; O'Brien, Mia

    2012-01-01

    Proportional reasoning is an important aspect of formal thinking that is acquired during the developmental years that approximate the middle years of schooling. Students who fail to acquire sound proportional reasoning often experience difficulties in subjects that require quantitative thinking, such as science, technology, engineering, and…

  14. Adaptive bayesian analysis for binomial proportions

    CSIR Research Space (South Africa)

    Das, Sonali

    2008-10-01

    Full Text Available of testing the proportion of some trait. For example, say, we are interested to infer about the effectiveness of a certain intervention teaching strategy, by comparing proportion of ‘proficient’ teachers, before and after an intervention. The number...

  15. Mix Proportion Design of Asphalt Concrete

    Science.gov (United States)

    Wu, Xianhu; Gao, Lingling; Du, Shoujun

    2017-12-01

    Based on the gradation of AC and SMA, this paper designs a new type of anti slide mixture with two types of advantages. Chapter introduces the material selection, ratio of ore mixture ratio design calculation, and determine the optimal asphalt content test and proportioning design of asphalt concrete mix. This paper introduces the new technology of mix proportion.

  16. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... This analysis starts with a review of ocean transportation demand and supply including projections of ship capacity demand and world shipbuilding capacity under various economic and political assumptions...

  17. Proportional gas scintillation detectors and their applications

    International Nuclear Information System (INIS)

    Petr, I.

    1978-01-01

    The principle is described of a gas proportional scintillation detector and its function. Dependence of Si(Li) and xenon proportional detectors energy resolution on the input window size is given. A typical design is shown of a xenon detector used for X-ray spetrometry at an energy of 277 eV to 5.898 keV and at a gas pressure of 98 to 270 kPa. Gas proportional scintillation detectors show considerable better energy resolution than common proportional counters and even better resolution than semiconductor Si(Li) detectors for low X radiation energies. For detection areas smaller than 25 mm 2 Si(Li) detectors show better resolution, especially for higher X radiation energies. For window areas 25 to 190 mm 2 both types of detectors are equal, for a window area exceeding 190 mm 2 the proportional scintillation detector has higher energy resolution. (B.S.)

  18. High-pressure metamorphic age and significance of eclogite-facies continental fragments associated with oceanic lithosphere in the Western Alps (Etirol-Levaz Slice, Valtournenche, Italy)

    Science.gov (United States)

    Fassmer, Kathrin; Obermüller, Gerrit; Nagel, Thorsten J.; Kirst, Frederik; Froitzheim, Nikolaus; Sandmann, Sascha; Miladinova, Irena; Fonseca, Raúl O. C.; Münker, Carsten

    2016-05-01

    The Etirol-Levaz Slice in the Penninic Alps (Valtournenche, Italy) is a piece of eclogite-facies continental basement sandwiched between two oceanic units, the blueschist-facies Combin Zone in the hanging wall and the eclogite-facies Zermatt-Saas Zone in the footwall. It has been interpreted as an extensional allochthon from the continental margin of Adria, emplaced onto ultramafic and mafic basement of the future Zermatt-Saas Zone by Jurassic, rifting-related detachment faulting, and later subducted together with the future Zermatt-Saas Zone. Alternatively, the Etirol-Levaz Slice could be derived from a different paleogeographic domain and be separated from the Zermatt-Saas Zone by an Alpine shear zone. We present Lu-Hf whole rock-garnet ages of two eclogite samples, one from the center of the unit and one from the border to the Zermatt-Saas Zone below. These data are accompanied by a new geological map of the Etirol-Levaz Slice and the surrounding area, as well as detailed petrology of these two samples. Assemblages, mineral compositions and garnet zoning in both samples indicate a clockwise PT-path and peak-metamorphic conditions of about 550-600 °C/20-25 kbar, similar to conditions proposed for the underlying Zermatt-Saas Zone. Prograde garnet ages of the two samples are 61.8 ± 1.8 Ma and 52.4 ± 2.1 Ma and reflect different timing of subduction. One of these is significantly older than published ages of eclogite-facies metamorphism in the Zermatt-Saas Zone and thus contradicts the hypothesis of Mesozoic emplacement. The occurrence of serpentinite and metagabbro bodies possibly derived from the Zermatt-Saas Zone inside the Etirol-Levaz Slice suggests that the latter is a tectonic composite. The basement slivers forming the Etirol-Levaz Slice and other continental fragments were subducted earlier than the Zermatt-Saas Zone, but nonetheless experienced similar pressure-temperature histories. Our results support the hypothesis that the Zermatt-Saas Zone and the

  19. Establishing demographic parameters for loggerhead turtles in the northeastern Pacific Ocean: growth rates, age determination, annual habitat use, and population connectivity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Loggerhead turtles nesting in Japan (i.e. the source rookery for individuals along the U.S. West coast and Pacific Mexico) have recently been declared a Distinct...

  20. Ocean technology

    Digital Repository Service at National Institute of Oceanography (India)

    Peshwe, V.B.

    stream_size 2 stream_content_type text/plain stream_name Voices_Oceans_1996_113.pdf.txt stream_source_info Voices_Oceans_1996_113.pdf.txt Content-Encoding ISO-8859-1 Content-Type text/plain; charset=ISO-8859-1 ...

  1. Ocean acidification

    National Research Council Canada - National Science Library

    Gattuso, J.P; Hansson, L

    2011-01-01

    The fate of much of the CO 2 we produce will be to enter the ocean. In a sense, we are fortunate that ocean water is endowed with the capacity to absorb far more CO 2 per litre than were it salt free...

  2. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A critical evaluaton is presented of the actual state of investigations and explanations of the resolution and pulse height changes resulted in proportional counters from radiation intensity variations. (author)

  3. Ocean energy

    International Nuclear Information System (INIS)

    2006-01-01

    This annual evaluation is a synthesis of works published in 2006. Comparisons are presented between the wind power performances and European Commission White Paper and Biomass action plan objectives. The sector covers the energy exploitation of all energy flows specifically supplied by the seas and oceans. At present, most efforts in both research and development and in experimental implementation are concentrated on tidal currents and wave power. 90% of today worldwide ocean energy production is represented by a single site: the Rance Tidal Power Plant. Ocean energies must face up two challenges: progress has to be made in finalizing and perfecting technologies and costs must be brought under control. (A.L.B.)

  4. Proportion congruency effects: Instructions may be enough

    Directory of Open Access Journals (Sweden)

    Olga eEntel

    2014-10-01

    Full Text Available Learning takes time, namely, one needs to be exposed to contingency relations between stimulus dimensions in order to learn, whereas intentional control can be recruited through task demands. Therefore showing that control can be recruited as a function of experimental instructions alone, that is, adapting the processing according to the instructions before the exposure to the task, can be taken as evidence for existence of control recruitment in the absence of learning. This was done by manipulating the information given at the outset of the experiment. In the first experiment, we manipulated list-level congruency proportion. Half of the participants were informed that most of the stimuli would be congruent, whereas the other half were informed that most of the stimuli would be incongruent. This held true for the stimuli in the second part of each experiment. In the first part, however, the proportion of the two stimulus types was equal. A proportion congruent effect was found in both parts of the experiment, but it was larger in the second part. In our second experiment, we manipulated the proportion of the stimuli within participants by applying an item-specific design. This was done by presenting some color words most often in their congruent color, and other color words in incongruent colors. Participants were informed about the exact word-color pairings in advance. Similar to Experiment 1, this held true only for the second experimental part. In contrast to our first experiment, informing participants in advance did not result in an item-specific proportion effect, which was observed only in the second part. Thus our results support the hypothesis that instructions may be enough to trigger list-level control, yet learning does contribute to the proportion congruent effect under such conditions. The item-level proportion effect is apparently caused by learning or at least it is moderated by it.

  5. Ocean Acidification

    Science.gov (United States)

    Ocean and coastal acidification is an emerging issue caused by increasing amounts of carbon dioxide being absorbed by seawater. Changing seawater chemistry impacts marine life, ecosystem services, and humans. Learn what EPA is doing and what you can do.

  6. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... The discussion of technology considers the ocean transportation system as a whole, and the composite subsystems such as hull, outfit, propulsion, cargo handling, automation, and control and interface technology...

  7. Ocean transportation

    National Research Council Canada - National Science Library

    Frankel, Ernst G; Marcus, Henry S

    1973-01-01

    .... In ocean transportation economics we present investment and operating costs as well as the results of a study of financing of shipping. Similarly, a discussion of government aid to shipping is presented.

  8. Ocean Color

    Data.gov (United States)

    National Aeronautics and Space Administration — Satellite-derived Ocean Color Data sets from historical and currently operational NASA and International Satellite missions including the NASA Coastal Zone Color...

  9. Ocean Quality

    OpenAIRE

    Brevik, Roy Schjølberg; Jordheim, Nikolai; Martinsen, John Christian; Labori, Aleksander; Torjul, Aleksander Lelis

    2017-01-01

    Bacheloroppgave i Internasjonal Markedsføring fra ESADE i Spania, 2017 In this thesis we were going to answer the problem definition “which segments in the Spanish market should Ocean Quality target”. By doing so we started to collect data from secondary sources in order to find information about the industry Ocean Quality are operating in. After conducting the secondary research, we still lacked essential information about the existing competition in the aquaculture industry o...

  10. Proportional hazards models of infrastructure system recovery

    International Nuclear Information System (INIS)

    Barker, Kash; Baroud, Hiba

    2014-01-01

    As emphasis is being placed on a system's ability to withstand and to recover from a disruptive event, collectively referred to as dynamic resilience, there exists a need to quantify a system's ability to bounce back after a disruptive event. This work applies a statistical technique from biostatistics, the proportional hazards model, to describe (i) the instantaneous rate of recovery of an infrastructure system and (ii) the likelihood that recovery occurs prior to a given point in time. A major benefit of the proportional hazards model is its ability to describe a recovery event as a function of time as well as covariates describing the infrastructure system or disruptive event, among others, which can also vary with time. The proportional hazards approach is illustrated with a publicly available electric power outage data set

  11. The Origins of Scintillator Non-Proportionality

    Science.gov (United States)

    Moses, W. W.; Bizarri, G. A.; Williams, R. T.; Payne, S. A.; Vasil'ev, A. N.; Singh, J.; Li, Q.; Grim, J. Q.; Choong, W.-S.

    2012-10-01

    Recent years have seen significant advances in both theoretically understanding and mathematically modeling the underlying causes of scintillator non-proportionality. The core cause is that the interaction of radiation with matter invariably leads to a non-uniform ionization density in the scintillator, coupled with the fact that the light yield depends on the ionization density. The mechanisms that lead to the luminescence dependence on ionization density are incompletely understood, but several important features have been identified, notably Auger-like processes (where two carriers of excitation interact with each other, causing one to de-excite non-radiatively), the inability of excitation carriers to recombine (caused either by trapping or physical separation), and the carrier mobility. This paper reviews the present understanding of the fundamental origins of scintillator non-proportionality, specifically the various theories that have been used to explain non-proportionality.

  12. Large-Scale Analysis of Art Proportions

    DEFF Research Database (Denmark)

    Jensen, Karl Kristoffer

    2014-01-01

    While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square) and with majo......While literature often tries to impute mathematical constants into art, this large-scale study (11 databases of paintings and photos, around 200.000 items) shows a different truth. The analysis, consisting of the width/height proportions, shows a value of rarely if ever one (square...

  13. Sexually dimorphic proportions of the harbour porpoise (Phocoena phocoena) skeleton

    DEFF Research Database (Denmark)

    Galatius, Anders

    2005-01-01

    Sexual differences in growth, allometric growth patterns and skeletal proportions were investigated by linear measurements of skeletal parts on 225 harbour porpoises (Phocoena phocoena) from the inner Danish and adjacent waters. Females show larger asymptotic sizes and extended period of growth...... to females is also found in the vertebral epiphyses that mature later in males than females, although the males finish growth at a younger age....

  14. Investigation of a multiwire proportional chamber

    International Nuclear Information System (INIS)

    Konijn, J.

    1976-01-01

    The article discusses some aspects of a prototype multiwire proportional chamber for electron detection located at IKO in Amsterdam, i.e. voltage, counting rates, noise and gas mixture (argon, ethylene bromide). The efficiency and performance of the chamber have been investigated and an error analysis is given

  15. Author: IM Rautenbach PROPORTIONALITY AND THE LIMITATION ...

    African Journals Online (AJOL)

    10332324

    public law, it is not clear to me that there are any differences at this more abstract ... Bills of Rights entrench "basic principles of rationality and proportionality – of ..... Sweet Europe of Rights 10-11; Van Dijk and Van Hoof Theory and Practice.

  16. Obtaining a Proportional Allocation by Deleting Items

    NARCIS (Netherlands)

    Dorn, B.; de Haan, R.; Schlotter, I.; Röthe, J.

    2017-01-01

    We consider the following control problem on fair allocation of indivisible goods. Given a set I of items and a set of agents, each having strict linear preference over the items, we ask for a minimum subset of the items whose deletion guarantees the existence of a proportional allocation in the

  17. Proportional green time scheduling for traffic lights

    NARCIS (Netherlands)

    P. Kovacs; Le, T. (Tung); R. Núñez Queija (Rudesindo); Vu, H. (Hai); N. Walton

    2016-01-01

    textabstractWe consider the decentralized scheduling of a large number of urban traffic lights. We investigate factors determining system performance, in particular, the length of the traffic light cycle and the proportion of green time allocated to each junction. We study the effect of the length

  18. Triangular tube proportional wire chamber system

    Energy Technology Data Exchange (ETDEWEB)

    Badtke, D H; Bakken, J A; Barnett, B A; Blumenfeld, B J; Chien, C Y; Madansky, L; Matthews, J A.J.; Pevsner, A; Spangler, W J [Johns Hopkins Univ., Baltimore, MD (USA); Lee, K L [California Univ., Berkeley (USA). Lawrence Berkeley Lab.

    1981-10-15

    We report on the characteristics of the proportional tube chamber system which has been constructed for muon identification in the PEP-4 experiment at SLAC. The mechanical and electrical properties of the extruded aluminum triangular tubes allow these detectors to be used as crude drift chambers.

  19. Commanding to 'Nudge' via the Proportionality Principle?

    NARCIS (Netherlands)

    K.P. Purnhagen (Kai); E. van Kleef (Ellen)

    2017-01-01

    textabstractThis piece assesses whether nudging techniques can be argued to be a less restrictive but equally effective way to regulate diets in EU law. It has been argued that nudging techniques, due to their freedom-preserving nature, might influence the proportionality test in such a way that

  20. Oceans Past

    DEFF Research Database (Denmark)

    Based on research for the History of Marine Animal Populations project, Oceans Past examines the complex relationship our forebears had with the sea and the animals that inhabit it. It presents eleven studies ranging from fisheries and invasive species to offshore technology and the study of marine...... environmental history, bringing together the perspectives of historians and marine scientists to enhance understanding of ocean management of the past, present and future. In doing so, it also highlights the influence that changes in marine ecosystems have upon the politics, welfare and culture of human...

  1. Ocean energy

    International Nuclear Information System (INIS)

    2009-01-01

    There are 5 different ways of harnessing ocean energy: tides, swells, currents, osmotic pressure and deep water thermal gradients. The tidal power sector is the most mature. A single French site - The Rance tidal power station (240 MW) which was commissioned in 1966 produces 90% of the world's ocean energy. Smaller scale power stations operate around the world, 10 are operating in the European Union and 5 are being tested. Underwater generators and wave energy converters are expanding. In France a 1 km 2 sea test platform is planned for 2010. (A.C.)

  2. Pulse triggering mechanism of air proportional counters

    International Nuclear Information System (INIS)

    Aoyama, T.; Mori, T.; Watanabe, T.

    1983-01-01

    This paper describes the pulse triggering mechanism of a cylindrical proportional counter filled with air at atmospheric pressure for the incidence of β-rays. Experimental results indicate that primary electrons created distantly from the anode wire by a β-ray are transformed into negative ions, which then detach electrons close to the anode wire and generate electron avalanches thus triggering pulses, while electrons created near the anode wire by a β-ray directly trigger a pulse. Since a negative ion pulse is triggered by a single electron detached from a negative ion, multiple pulses are generated by a large number of ions produced by the incidence of a single β-ray. It is therefore necessary not to count pulses triggered by negative ions but to count those by primary electrons alone when use is made of air proportional counters for the detection of β-rays. (orig.)

  3. Very large area multiwire spectroscopic proportional counters

    International Nuclear Information System (INIS)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F.

    1981-01-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) succesfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm 2 with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results. (orig.)

  4. Very large area multiwire spectroscopic proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Ubertini, P.; Bazzano, A.; Boccaccini, L.; Mastropietro, M.; La Padula, C.D.; Patriarca, R.; Polcaro, V.F. (Istituto di Astrofisica Spaziale, Frascati (Italy))

    1981-07-01

    As a result of a five year development program, a final prototype of a Very Large Area Spectroscopic Proportional Counter (VLASPC), to be employed in space borne payloads, was produced at the Istituto di Astrofisica Spaziale, Frascati. The instrument is the last version of a new generation of Multiwire Spectroscopic Proportional Counters (MWSPC) successfully employed in many balloon borne flights, devoted to hard X-ray astronomy. The sensitive area of this standard unit is 2700 cm/sup 2/ with an efficiency higher than 10% in the range 15-180 keV (80% at 60 keV). The low cost and weight make this new type of VLASPC competitive with Nal arrays, phoswich and GSPC detectors in terms of achievable scientific results.

  5. Cylindrical geometry for proportional and drift chambers

    International Nuclear Information System (INIS)

    Sadoulet, B.

    1975-06-01

    For experiments performed around storage rings such as e + e - rings or the ISR pp rings, cylindrical wire chambers are very attractive. They surround the beam pipe completely without any dead region in the azimuth, and fit well with the geometry of events where particles are more or less spherically produced. Unfortunately, cylindrical proportional or drift chambers are difficult to make. Problems are discussed and two approaches to fabricating the cathodes are discussed. (WHK)

  6. 2 π gaseous flux proportional detector

    International Nuclear Information System (INIS)

    Guevara, E.A.; Costello, E.D.; Di Carlo, R.O.

    1986-01-01

    A counting system has been developed in order to measure carbon-14 samples obtained in the course of a study of a plasmapheresis treatment for diabetic children. The system is based on the use of a 2π gaseous flux proportional detector especially designed for the stated purpose. The detector is described and experiment results are given, determining the characteristic parameters which set up the working conditions. (Author) [es

  7. General methods for analyzing bounded proportion data

    OpenAIRE

    Hossain, Abu

    2017-01-01

    This thesis introduces two general classes of models for analyzing proportion response variable when the response variable Y can take values between zero and one, inclusive of zero and/or one. The models are inflated GAMLSS model and generalized Tobit GAMLSS model. The inflated GAMLSS model extends the flexibility of beta inflated models by allowing the distribution on (0,1) of the continuous component of the dependent variable to come from any explicit or transformed (i.e. logit or truncated...

  8. Commanding to 'Nudge' via the Proportionality Principle?

    OpenAIRE

    Purnhagen, Kai; van Kleef, Ellen

    2017-01-01

    textabstractThis piece assesses whether nudging techniques can be argued to be a less restrictive but equally effective way to regulate diets in EU law. It has been argued that nudging techniques, due to their freedom-preserving nature, might influence the proportionality test in such a way that authorities need to give preference to nudging techniques over content-related or information regulation. We will illustrate on the example of EU food law how behavioural sciences have first altered t...

  9. Contingency proportion systematically influences contingency learning.

    Science.gov (United States)

    Forrin, Noah D; MacLeod, Colin M

    2018-01-01

    In the color-word contingency learning paradigm, each word appears more often in one color (high contingency) than in the other colors (low contingency). Shortly after beginning the task, color identification responses become faster on the high-contingency trials than on the low-contingency trials-the contingency learning effect. Across five groups, we varied the high-contingency proportion in 10% steps, from 80% to 40%. The size of the contingency learning effect was positively related to high-contingency proportion, with the effect disappearing when high contingency was reduced to 40%. At the two highest contingency proportions, the magnitude of the effect increased over trials, the pattern suggesting that there was an increasing cost for the low-contingency trials rather than an increasing benefit for the high-contingency trials. Overall, the results fit a modified version of Schmidt's (2013, Acta Psychologica, 142, 119-126) parallel episodic processing account in which prior trial instances are routinely retrieved from memory and influence current trial performance.

  10. Ocean Ridges and Oxygen

    Science.gov (United States)

    Langmuir, C. H.

    2014-12-01

    The history of oxygen and the fluxes and feedbacks that lead to its evolution through time remain poorly constrained. It is not clear whether oxygen has had discrete steady state levels at different times in Earth's history, or whether oxygen evolution is more progressive, with trigger points that lead to discrete changes in markers such as mass independent sulfur isotopes. Whatever this history may have been, ocean ridges play an important and poorly recognized part in the overall mass balance of oxidants and reductants that contribute to electron mass balance and the oxygen budget. One example is the current steady state O2 in the atmosphere. The carbon isotope data suggest that the fraction of carbon has increased in the Phanerozoic, and CO2 outgassing followed by organic matter burial should continually supply more O2 to the surface reservoirs. Why is O2 not then increasing? A traditional answer to this question would relate to variations in the fraction of burial of organic matter, but this fraction appears to have been relatively high throughout the Phanerozoic. Furthermore, subduction of carbon in the 1/5 organic/carbonate proportions would contribute further to an increasingly oxidized surface. What is needed is a flux of oxidized material out of the system. One solution would be a modern oxidized flux to the mantle. The current outgassing flux of CO2 is ~3.4*1012 moles per year. If 20% of that becomes stored organic carbon, that is a flux of .68*1012 moles per year of reduced carbon. The current flux of oxidized iron in subducting ocean crust is ~2*1012 moles per year of O2 equivalents, based on the Fe3+/Fe2+ ratios in old ocean crust compared to fresh basalts at the ridge axis. This flux more than accounts for the incremental oxidizing power produced by modern life. It also suggests a possible feedback through oxygenation of the ocean. A reduced deep ocean would inhibit oxidation of ocean crust, in which case there would be no subduction flux of oxidized

  11. Proportionality in enterprise development of South African towns

    Directory of Open Access Journals (Sweden)

    Maitland T. Seaman

    2012-05-01

    Full Text Available We investigated proportionalities in the enterprise structures of 125 South African towns through examining four hypotheses, (1 the magnitude of enterprise development in a town is a function of the population size of the town; (2 the size of an enterprise assemblage of a town is a function of the town’s age; (3 there are statistically significant relationships, and hence proportionalities, between the total number of enterprises in towns and some, if not all, of the enterprise numbers of different business sectors in towns; and (4 the implications of proportionalities have far-reaching implications for rural development and job creation. All hypotheses were accepted on the basis of statistically significant (p < 0.05 correlations, except for the second hypothesis – the age of a town does not determine the size of its enterprise assemblage. Analysis for the fourth hypothesis suggested that there are two broad entrepreneurial types in South African towns: ‘run-of-the-mill’ entrepreneurs and ‘special’ entrepreneurs, which give rise to different enterprise development dynamics. ‘Run-of-the-mill’ enterprises are dependent on, and limited by, local demand and if there is only a small demand, the entrepreneurial space is small. By comparison, ‘special’ enterprises have much larger markets because their products and/or services are exportable. We propose that the fostering of ‘special’ entrepreneurs is an imperative for local economic development in South African towns.

  12. Ocean Acidification

    Science.gov (United States)

    Ludwig, Claudia; Orellana, Mónica V.; DeVault, Megan; Simon, Zac; Baliga, Nitin

    2015-01-01

    The curriculum module described in this article addresses the global issue of ocean acidification (OA) (Feely 2009; Figure 1). OA is a harmful consequence of excess carbon dioxide (CO[subscript 2]) in the atmosphere and poses a threat to marine life, both algae and animal. This module seeks to teach and help students master the cross-disciplinary…

  13. Ocean energies

    International Nuclear Information System (INIS)

    Charlier, R.H.; Justus, J.R.

    1993-01-01

    This timely volume provides a comprehensive review of current technology for all ocean energies. It opens with an analysis of ocean thermal energy conversion (OTEC), with and without the use of an intermediate fluid. The historical and economic background is reviewed, and the geographical areas in which this energy could be utilized are pinpointed. The production of hydrogen as a side product, and environmental consequences of OTEC plants are considered. The competitiveness of OTEC with conventional sources of energy is analysed. Optimisation, current research and development potential are also examined. Separate chapters provide a detailed examination of other ocean energy sources. The possible harnessing of solar ponds, ocean currents, and power derived from salinity differences is considered. There is a fascinating study of marine winds, and the question of using the ocean tides as a source of energy is examined, focussing on a number of tidal power plant projects, including data gathered from China, Australia, Great Britain, Korea and the USSR. Wave energy extraction has excited recent interest and activity, with a number of experimental pilot plants being built in northern Europe. This topic is discussed at length in view of its greater chance of implementation. Finally, geothermal and biomass energy are considered, and an assessment of their future is given. The authors also distinguished between energy schemes which might be valuable in less-industrialized regions of the world, but uneconomical in the developed countries. A large number of illustrations support the text. This book will be of particular interest to energy economists, engineers, geologists and oceanographers, and to environmentalists and environmental engineers

  14. Turbines in the ocean

    Science.gov (United States)

    Smith, F. G. W.; Charlier, R. H.

    1981-10-01

    It is noted that the relatively high-speed ocean currents flowing northward along the east coast of the U.S. may be able to supply a significant proportion of the future electric power requirements of urban areas. The Gulf Stream core lies only about 20 miles east of Miami; here its near-surface water reaches velocities of 4.3 miles per hour. Attention is called to the estimate that the energy available in the current of the Gulf Stream adjacent to Florida is approximately equivalent to that generated by 25 1,000-megawatt power plants. It is also contended that this power could be produced at competitive prices during the 1980s using large turbines moored below the ocean surface near the center of the Stream. Assuming an average ocean-current speed between 4 and 5 knots at the current core, the power density of a hydroturbine could reach 410 watts per square foot, about 100 times that of a wind-driven device of similar scale operating in an airflow of approximately 11 knots.

  15. Designing an optimally proportional inorganic scintillator

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Jai, E-mail: jai.singh@cdu.edu.au [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia); Koblov, Alexander [School of Engineering and IT, B-Purple-12, Faculty of EHSE, Charles Darwin University, NT 0909 (Australia)

    2012-09-01

    The nonproportionality observed in the light yield of inorganic scintillators is studied theoretically as a function of the rates of bimolecular and Auger quenching processes occurring within the electron track initiated by a gamma- or X-ray photon incident on a scintillator. Assuming a cylindrical track, the influence of the track radius and concentration of excitations created within the track on the scintillator light yield is also studied. Analysing the calculated light yield a guideline for inventing an optimally proportional scintillator with optimal energy resolution is presented.

  16. Designing an optimally proportional inorganic scintillator

    International Nuclear Information System (INIS)

    Singh, Jai; Koblov, Alexander

    2012-01-01

    The nonproportionality observed in the light yield of inorganic scintillators is studied theoretically as a function of the rates of bimolecular and Auger quenching processes occurring within the electron track initiated by a gamma- or X-ray photon incident on a scintillator. Assuming a cylindrical track, the influence of the track radius and concentration of excitations created within the track on the scintillator light yield is also studied. Analysing the calculated light yield a guideline for inventing an optimally proportional scintillator with optimal energy resolution is presented.

  17. Rate dependent image distortions in proportional counters

    International Nuclear Information System (INIS)

    Trow, M.W.; Bento, A.C.; Smith, A.

    1994-01-01

    The positional linearity of imaging proportional counters is affected by the intensity distribution of the incident radiation. A mechanism for this effect is described, in which drifting positive ions in the gas produce a distorting electric field which perturbs the trajectories of the primary electrons. In certain cases, the phenomenon causes an apparent improvement of the position resolution. We demonstrate the effect in a detector filled with a xenon-argon-CO 2 mixture. The images obtained are compared with the results of a simulation. If quantitative predictions for a particular detector are required, accurate values of the absolute detector gain, ion mobility and electron drift velocity are needed. ((orig.))

  18. Hydrogen high pressure proportional drift detector

    International Nuclear Information System (INIS)

    Arefiev, A.; Balaev, A.

    1983-01-01

    The design and operation performances of a proportional drift detector PDD are described. High sensitivity of the applied PAD makes it possible to detect the neutron-proton elastic scattering in the energy range of recoil protons as low as 1 keV. The PDD is filled with hydrogen up to the pressure at 40 bars. High purity of the gas is maintained by a continuously operating purification system. The detector has been operating for several years in a neutron beam at the North Area of the CERN SPS

  19. Optimization of maintenance policy using the proportional hazard model

    Energy Technology Data Exchange (ETDEWEB)

    Samrout, M. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: mohamad.el_samrout@utt.fr; Chatelet, E. [Information Sciences and Technologies Institute, University of Technology of Troyes, 10000 Troyes (France)], E-mail: chatelt@utt.fr; Kouta, R. [M3M Laboratory, University of Technology of Belfort Montbeliard (France); Chebbo, N. [Industrial Systems Laboratory, IUT, Lebanese University (Lebanon)

    2009-01-15

    The evolution of system reliability depends on its structure as well as on the evolution of its components reliability. The latter is a function of component age during a system's operating life. Component aging is strongly affected by maintenance activities performed on the system. In this work, we consider two categories of maintenance activities: corrective maintenance (CM) and preventive maintenance (PM). Maintenance actions are characterized by their ability to reduce this age. PM consists of actions applied on components while they are operating, whereas CM actions occur when the component breaks down. In this paper, we expound a new method to integrate the effect of CM while planning for the PM policy. The proportional hazard function was used as a modeling tool for that purpose. Interesting results were obtained when comparison between policies that take into consideration the CM effect and those that do not is established.

  20. Amplifier Design for Proportional Ionization Chambers

    Energy Technology Data Exchange (ETDEWEB)

    Baker, W. H.

    1950-08-24

    This paper presents the requirements of a nuclear amplifier of short resolving time, designed to accept pulses of widely varying amplitudes. Data are given which show that a proportional ionization chamber loaded with a 1,000-ohm resistor develops pulses of 0.5 microsecond duration and several volts amplitude. Results indicate that seven basic requirements are imposed on the amplifier when counting soft beta and gamma radiation in the presence of alpha particles, without absorbers. It should, (1) have a fast recovery time, (2) have a relatively good low frequency response, (3) accept pulses of widely varying heights without developing spurious pulsed, (4) have a limiting output stage, (5) preserve the inherently short rise time of the chamber, (6) minimize pulse integration, and (7) have sufficient gain to detect the weak pulses well below the chamber voltage at which continuous discharge takes place. The results obtained with an amplifier which meets these requirements is described. A formula is derived which indicates that redesign of the proportional ionization chamber might eliminate the need for an amplifier. This may be possible if the radioactive particles are collimated parallel to the collecting electrode.

  1. Divine proportions in attractive and nonattractive faces.

    Science.gov (United States)

    Pancherz, Hans; Knapp, Verena; Erbe, Christina; Heiss, Anja Melina

    2010-01-01

    To test Ricketts' 1982 hypothesis that facial beauty is measurable by comparing attractive and nonattractive faces of females and males with respect to the presence of the divine proportions. The analysis of frontal view facial photos of 90 cover models (50 females, 40 males) from famous fashion magazines and of 34 attractive (29 females, five males) and 34 nonattractive (13 females, 21 males) persons selected from a group of former orthodontic patients was carried out in this study. Based on Ricketts' method, five transverse and seven vertical facial reference distances were measured and compared with the corresponding calculated divine distances expressed in phi-relationships (f=1.618). Furthermore, transverse and vertical facial disproportion indices were created. For both the models and patients, all the reference distances varied largely from respective divine values. The average deviations ranged from 0.3% to 7.8% in the female groups of models and attractive patients with no difference between them. In the male groups of models and attractive patients, the average deviations ranged from 0.2% to 11.2%. When comparing attractive and nonattractive female, as well as male, patients, deviations from the divine values for all variables were larger in the nonattractive sample. Attractive individuals have facial proportions closer to the divine values than nonattractive ones. In accordance with the hypothesis of Ricketts, facial beauty is measurable to some degree. COPYRIGHT © 2009 BY QUINTESSENCE PUBLISHING CO, INC.

  2. Kalman-predictive-proportional-integral-derivative (KPPID)

    International Nuclear Information System (INIS)

    Fluerasu, A.; Sutton, M.

    2004-01-01

    With third generation synchrotron X-ray sources, it is possible to acquire detailed structural information about the system under study with time resolution orders of magnitude faster than was possible a few years ago. These advances have generated many new challenges for changing and controlling the state of the system on very short time scales, in a uniform and controlled manner. For our particular X-ray experiments on crystallization or order-disorder phase transitions in metallic alloys, we need to change the sample temperature by hundreds of degrees as fast as possible while avoiding over or under shooting. To achieve this, we designed and implemented a computer-controlled temperature tracking system which combines standard Proportional-Integral-Derivative (PID) feedback, thermal modeling and finite difference thermal calculations (feedforward), and Kalman filtering of the temperature readings in order to reduce the noise. The resulting Kalman-Predictive-Proportional-Integral-Derivative (KPPID) algorithm allows us to obtain accurate control, to minimize the response time and to avoid over/under shooting, even in systems with inherently noisy temperature readings and time delays. The KPPID temperature controller was successfully implemented at the Advanced Photon Source at Argonne National Laboratories and was used to perform coherent and time-resolved X-ray diffraction experiments.

  3. Proportional-Integral-Resonant AC Current Controller

    Directory of Open Access Journals (Sweden)

    STOJIC, D.

    2017-02-01

    Full Text Available In this paper an improved stationary-frame AC current controller based on the proportional-integral-resonant control action (PIR is proposed. Namely, the novel two-parameter PIR controller is applied in the stationary-frame AC current control, accompanied by the corresponding parameter-tuning procedure. In this way, the proportional-resonant (PR controller, common in the stationary-frame AC current control, is extended by the integral (I action in order to enable the AC current DC component tracking, and, also, to enable the DC disturbance compensation, caused by the voltage source inverter (VSI nonidealities and by nonlinear loads. The proposed controller parameter-tuning procedure is based on the three-phase back-EMF-type load, which corresponds to a wide range of AC power converter applications, such as AC motor drives, uninterruptible power supplies, and active filters. While the PIR controllers commonly have three parameters, the novel controller has two. Also, the provided parameter-tuning procedure needs only one parameter to be tuned in relation to the load and power converter model parameters, since the second controller parameter is directly derived from the required controller bandwidth value. The dynamic performance of the proposed controller is verified by means of simulation and experimental runs.

  4. Verbal and perceptual analogical reasoning and proportional metaphor comprehension in young children.

    Science.gov (United States)

    Nippold, M A; Sullivan, M P

    1987-09-01

    In contrast to the common assumption that young children have little or no ability to reason by analogy or to comprehend proportional metaphors, the present study demonstrated that children as young as age 5 years have an emerging ability to solve both verbal and perceptual proportional analogy problems and to detect the meanings of proportional metaphoric sentences. These results were largely because the experimental tasks were designed to minimize the number of factors that would restrict the performance of young children. The results indicated that the years between 5 and 7 mark a steady improvement in analogical reasoning and proportional metaphor comprehension, but that children ages 5, 6, and 7 display a wide-ranging ability in these areas. It was also found that perceptual analogical reasoning was statistically related to verbal analogical reasoning and to proportional metaphor comprehension, and that perceptual analogical reasoning and proportional metaphor comprehension were both statistically related to receptive vocabulary development.

  5. Proceedings of oceans '91

    International Nuclear Information System (INIS)

    Anon.

    1991-01-01

    This volume contains the proceedings of the Oceans '91 Conference. Topics addressed include: ocean energy conversion, marine communications and navigation, ocean wave energy conversion, environmental modeling, global climate change, ocean minerals technology, oil spill technology, and submersible vehicles

  6. Ocean acidification

    International Nuclear Information System (INIS)

    Soubelet, Helene; Veyre, Philippe; Monnoyer-Smith, Laurence

    2017-09-01

    This brief publication first recalls and outlines that ocean acidification is expected to increase, and will result in severe ecological impacts (more fragile coral reefs, migration of species, and so on), and therefore social and economic impacts. This issue is particularly important for France who possesses the second exclusive maritime area in the world. The various impacts of ocean acidification on living species is described, notably for phytoplankton, coral reefs, algae, molluscs, and fishes. Social and economic impacts are also briefly presented: tourism, protection against risks (notably by coral reefs), shellfish aquaculture and fishing. Issues to be addressed by scientific research are evoked: interaction between elements of an ecosystem and between different ecosystems, multi-stress effects all along organism lifetime, vulnerability and adaptability of human societies

  7. BCE selector valves and flow proportional sampler

    International Nuclear Information System (INIS)

    Rippy, G.L.

    1994-01-01

    This Acceptance Test Procedure (ATP) has been prepared to demonstrate that the Electrical/Instrumentation systems for the B-Plant Process Condensate Treatment Facility (BCE) function as required by project criteria. Tests will be run to: Verify the operation of the solenoid valve and associated limit switches installed for the BCE portion of W-007H; Operate the solenoid valve and verify the proper operation of the associated limit switches based on the position of the solenoid valve;and, Demonstrate the integrity of the Sample Failure Alarm Relay XFA-211BA-BCE-1, and Power Failure ALarm Relay JFA-211BA-BCE-1 located inside the Flow Proportional Sampler in Building 211 BA

  8. Absolute calibration of TFTR helium proportional counters

    International Nuclear Information System (INIS)

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

    1995-06-01

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

  9. CWRU multiwire proportional counter readout system

    International Nuclear Information System (INIS)

    Bevington, P.R.; Leskovec, R.A.

    1977-01-01

    An electronic system is described which translates pulses from individual wires of multiwire proportional counters into binary addresses indicating the location of the wires in the chambers. The system combines a fast (<100 ns) serial scan of an event buffer with parallel encoding to provide fast transfer of addresses (250 ns per hit). The buffer has provision for disabling the input less than 40 ns after detection of an event to suppress recording of multiple hits caused by individual events. The encoder can digitize the address of every hit encountered or just the first addresses of contiguous hits. The system includes a coincidence trigger for determining whether timing criteria have been satisfied between chambers and with external devices. Events which do not meet the coincidence criteria are typically reset within 400 ns. The addresses are transferred to a computer interface through CAMAC modules. Multiple buffering permits further data acquisition during CAMAC transfer cycles. (Auth.)

  10. Fabrication of preamplifier for proportional counter

    International Nuclear Information System (INIS)

    Lotfi, Y.; Yazdanpanah, M.; Talebi, B.; Mohammadi, A.; Etaati, Gh.

    2002-01-01

    We have tried to describe techniques of preamplifier fabrication for proportional counter. At first electronic circuit of preamplifier has been analyzed by means of Or cad 9.1. Then we assembled the circuit. Thereafter essential and standard parameters of preamplifier has been measured and compared with foreign made one, according to IEEE standard method. (IEEE Std 301-1988) Specification for our preamplifier is: 1. Rise time of output plus: 25 nsec. 2. Fall time of output pulse: 50μ sec. 3. Charge sensitive: 46.3 mV/pc. 4. Average noise: 500 ion pair (rms) 5. Count R ate L imit: 9.14*10 10 Count/sec. 6. Resolution: %1.3 7. Spectrum of Bf3 detector to 300μ Ci Am-Be source for this preamplifier is the same as foreign one. On the Whole comparison of this preamplifier with the foreign one shows that their parameters similarity is about %95

  11. Tables of Confidence Limits for Proportions

    Science.gov (United States)

    1990-09-01

    0.972 180 49 0.319 0.332 0,357 175 165 0.964 0.969 0.976 ISO 50 0.325 0.338 0.363 175 166 0.969 0.973 0.980 180 51 0.331 0.344 0.368 175 167 0.973 0.977...0.528 180 18 0.135 0 145 0.164 180 19 0.141 0.151 0.171 ISO 80 0.495 0,508 0.534 347 UPPER CONFIDENCE LIMIT FOR PROPORTIONS CONFIDENCE LEVEL...500 409 0.8401 0.8459 0.8565 500 355 0.7364 0.7434 0.7564 500 356 0.7383 0.7453 0.7582 500 410 0.8420 0.8478 0 8583 500 357 0.7402 0.7472 0.7602 500

  12. Proportional chamber with data analog output

    International Nuclear Information System (INIS)

    Popov, V.E.; Prokof'ev, A.N.

    1977-01-01

    A proportional multiwier chamber is described. The chamber makes it possible to determine angles at wich a pion strikes a polarized target. A delay line, made of 60-core flat cable is used for removing signals from the chamber. From the delay line, signals are amplified and successively injected into shapers and a time-to-amplitude converter. An amplitude of the time-to amplitude converter output signal unambiguously determines the coordinate of a point at which a particle strikes the chamber plane. There are also given circuits of amplifiers, which consist of a preamplifier with gain 30 and a main amplifier with adjustable gain. Data on testing the chamber with the 450 MeV pion beam is demonstrated. The chamber features an efficiency of about 98 per cent under load of 2x10 5 s -1

  13. Proportional representation apportionment methods and their applications

    CERN Document Server

    Pukelsheim, Friedrich

    2017-01-01

    The book offers an in-depth study of the translation of vote counts into seat numbers in proportional representation systems  – an approach guided by practical needs. It also provides plenty of empirical instances illustrating the results. It analyzes in detail the 2014 elections to the European Parliament in the 28 member states, as well as the 2009 and 2013 elections to the German Bundestag. This second edition is a complete revision and expanded version of the first edition published in 2014, and many empirical election results that serve as examples have been updated. Further, a final chapter has been added assembling biographical sketches and authoritative quotes from individuals who pioneered the development of apportionment methodology. The mathematical exposition and the interrelations with political science and constitutional jurisprudence make this an apt resource for interdisciplinary courses and seminars on electoral systems and apportionment methods.

  14. Quality measurement by proportional counter with B

    International Nuclear Information System (INIS)

    Onizuka, Yoshihiko; Endo, Satoru; Tanaka, Kenichi

    2005-01-01

    The dosimetry of air and the tissue-equivalent phantom made of acryl are carried out by the tissue-equivalent proportional counter (TEPC) and TEPC with wall contained B, and both results were compared. The changes of quality with distance from the beam center are determined by the frequency mean renewal energy y F (y)and the dose mean renewal energy y D (y) as indicators of quality. Both y F (y)and y D (y) of tissue-equivalent phantom are larger than air, but very large change was not observed in all distance. The dose rate is determined by y D (y), the number of events and measurement time. Change of dose rate was larger than the change of quality. The maximum value of dose rate depended on γray and neutron beam showed at the point 2 cm away from the center. (S.Y.)

  15. Proportional counter system for radiation measurement

    Energy Technology Data Exchange (ETDEWEB)

    Sugimoto, M; Okudera, S

    1970-11-21

    A gas such as Xe or Kr employed in counter tubes is charged into the counter tube of a gas-flow type proportional counter for radiation measurement and into a vessel having a volume larger than that of the counter tube. The vessel communicates with the counter tube to circulate the gas via a pump through both the vessel and tube during measurement. An organic film such as a polyester synthetic resin film is used for the window of the counter tube to measure X-rays in the long wavelength range. Accordingly, a wide range of X-rays can be measured including both long and short wavelengths ranges by utilizing only one counter tube, thus permitting the gases employed to be effectively used.

  16. Count rate effect in proportional counters

    International Nuclear Information System (INIS)

    Bednarek, B.

    1980-01-01

    A new concept is presented explaining changes in spectrometric parameters of proportional counters which occur due to varying count rate. The basic feature of this concept is that the gas gain of the counter remains constant in a wide range of count rate and that the decrease in the pulse amplitude and the detorioration of the energy resolution observed are the results of changes in the shape of original current pulses generated in the active volume of the counter. In order to confirm the validity of this statement, measurements of the gas amplification factor have been made in a wide count rate range. It is shown that above a certain critical value the gas gain depends on both the operating voltage and the count rate. (author)

  17. Proceedings of the International Workshop on age determination of oceanic pelagic fishes: Tunas, billfishes, and sharks, Miami, Florida, February 15-18,1982

    OpenAIRE

    1983-01-01

    Accurate and precise estimates of age and growth rates are essential parameters in understanding the population dynamics of fishes. Some of the more sophisticated stock assessment models, such as virtual population analysis, require age and growth information to partition catch data by age. Stock assessment efforts by regulatory agencies are usually directed at specific fisheries which are being heavily exploited and are suspected of being overfished. Interest in stock assessment of som...

  18. A phenomenological SMA model for combined axial–torsional proportional/non-proportional loading conditions

    International Nuclear Information System (INIS)

    Bodaghi, M.; Damanpack, A.R.; Aghdam, M.M.; Shakeri, M.

    2013-01-01

    In this paper, a simple and robust phenomenological model for shape memory alloys (SMAs) is proposed to simulate main features of SMAs under uniaxial as well as biaxial combined axial–torsional proportional/non-proportional loadings. The constitutive model for polycrystalline SMAs is developed within the framework of continuum thermodynamics of irreversible processes. The model nominates the volume fractions of self-accommodated and oriented martensite as scalar internal variables and the preferred direction of oriented martensitic variants as directional internal variable. An algorithm is introduced to develop explicit relationships for the thermo-mechanical behavior of SMAs under uniaxial and biaxial combined axial–torsional proportional/non-proportional loading conditions and also thermal loading. It is shown that the model is able to simulate main aspects of SMAs including self-accommodation, martensitic transformation, orientation and reorientation of martensite, shape memory effect, ferro-elasticity and pseudo-elasticity. A description of the time-discrete counterpart of the proposed SMA model is presented. Experimental results of uniaxial tension and biaxial combined tension–torsion non-proportional tests are simulated and a good qualitative correlation between numerical and experimental responses is achieved. Due to simplicity and accuracy, the model is expected to be used in the future studies dealing with the analysis of SMA devices in which two stress components including one normal and one shear stress are dominant

  19. Cox proportional hazards models have more statistical power than logistic regression models in cross-sectional genetic association studies

    NARCIS (Netherlands)

    van der Net, Jeroen B.; Janssens, A. Cecile J. W.; Eijkemans, Marinus J. C.; Kastelein, John J. P.; Sijbrands, Eric J. G.; Steyerberg, Ewout W.

    2008-01-01

    Cross-sectional genetic association studies can be analyzed using Cox proportional hazards models with age as time scale, if age at onset of disease is known for the cases and age at data collection is known for the controls. We assessed to what degree and under what conditions Cox proportional

  20. Depth of origin of ocean-circulation-induced magnetic signals

    Science.gov (United States)

    Irrgang, Christopher; Saynisch-Wagner, Jan; Thomas, Maik

    2018-01-01

    As the world ocean moves through the ambient geomagnetic core field, electric currents are generated in the entire ocean basin. These oceanic electric currents induce weak magnetic signals that are principally observable outside of the ocean and allow inferences about large-scale oceanic transports of water, heat, and salinity. The ocean-induced magnetic field is an integral quantity and, to first order, it is proportional to depth-integrated and conductivity-weighted ocean currents. However, the specific contribution of oceanic transports at different depths to the motional induction process remains unclear and is examined in this study. We show that large-scale motional induction due to the general ocean circulation is dominantly generated by ocean currents in the upper 2000 m of the ocean basin. In particular, our findings allow relating regional patterns of the oceanic magnetic field to corresponding oceanic transports at different depths. Ocean currents below 3000 m, in contrast, only contribute a small fraction to the ocean-induced magnetic signal strength with values up to 0.2 nT at sea surface and less than 0.1 nT at the Swarm satellite altitude. Thereby, potential satellite observations of ocean-circulation-induced magnetic signals are found to be likely insensitive to deep ocean currents. Furthermore, it is shown that annual temporal variations of the ocean-induced magnetic field in the region of the Antarctic Circumpolar Current contain information about sub-surface ocean currents below 1000 m with intra-annual periods. Specifically, ocean currents with sub-monthly periods dominate the annual temporal variability of the ocean-induced magnetic field.

  1. Calibration of proportional counters in microdosimetry

    International Nuclear Information System (INIS)

    Varma, M.N.

    1982-01-01

    Many microdosimetric spectra for low LET as well as high LET radiations are measured using commercially available (similar to EG and G) Rossi proportional counters. This paper discusses the corrections to be applied to data when calibration of the counter is made using one type of radiation, and then the counter is used in a different radiation field. The principal correction factor is due to differences in W-value of the radiation used for calibration and the radiation for which microdosimetric measurements are made. Both propane and methane base tissue-equivalent (TE) gases are used in these counters. When calibrating the detectors, it is important to use the correct stopping power value for that gas. Deviations in y-bar/sub F/ and y-bar/sub D/ are calculated for 60 Co using different extrapolation procedures from 0.15 keV/μm to zero event size. These deviations can be as large as 30%. Advantages of reporting microdosimetric parameters such as y-bar/sub F/ and y-bar/sub D/ above a certain minimum cut-off are discussed

  2. The Volvo Ocean Adventure

    Science.gov (United States)

    Boxall, S. R.; Flechter, S.; Byfield, Y.

    2003-04-01

    The Volvo Ocean Adventure is a web-based international programme for schools and young scientists in the 10-16 age range which was established in June 2001 (www.volvooceanadventure.org). Using the Volvo Ocean Race as its focus it made use of environmental data colletced from the yachts in the round the World race to introduce the public to a wide range of marine environmental topics including pollution, global climate change and fisheries. As well as web-based activities for the class room a variety of "road" shows were established with the race along with an international competition to encourage active participation by young people. The Adventure involved input from over 50 scientists form around the World with the first phase finishing in September 2002. The successes and lessons learned will be presented by the science co-ordinators of the project.

  3. Building a Global Ocean Science Education Network

    Science.gov (United States)

    Scowcroft, G. A.; Tuddenham, P. T.; Pizziconi, R.

    2016-02-01

    It is imperative for ocean science education to be closely linked to ocean science research. This is especially important for research that addresses global concerns that cross national boundaries, including climate related issues. The results of research on these critical topics must find its way to the public, educators, and students of all ages around the globe. To facilitate this, opportunities are needed for ocean scientists and educators to convene and identify priorities and strategies for ocean science education. On June 26 and 27, 2015 the first Global Ocean Science Education (GOSE) Workshop was convened in the United States at the University of Rhode Island Graduate School of Oceanography. The workshop, sponsored by the Consortium for Ocean Science Exploration and Engagement (COSEE) and the College of Exploration, had over 75 participants representing 15 nations. The workshop addressed critical global ocean science topics, current ocean science research and education priorities, advanced communication technologies, and leveraging international ocean research technologies. In addition, panels discussed elementary, secondary, undergraduate, graduate, and public education across the ocean basins with emphasis on opportunities for international collaboration. Special presentation topics included advancements in tropical cyclone forecasting, collaborations among Pacific Islands, ocean science for coastal resiliency, and trans-Atlantic collaboration. This presentation will focus on workshop outcomes as well as activities for growing a global ocean science education network. A summary of the workshop report will also be provided. The dates and location for the 2016 GOES Workshop will be announced. See http://www.coexploration.net/gose/index.html

  4. Warming and organic matter sources impact the proportion of dissolved to total activities in marine extracellular enzymatic rates

    KAUST Repository

    Baltar, Federico

    2017-04-19

    Extracellular enzymatic activities (EEAs) are the rate-limiting step in the degradation of organic matter. Extracellular enzymes can be found associated to cells or dissolved in the surrounding water. The proportion of cell-free EEA constitutes in many marine environments more than half of the total activity. This high proportion causes an uncoupling between hydrolysis rates and the actual bacterial activity. However, we do not know what factors control the proportion of dissolved relative to total EEA, nor how this may change in the future ocean. To resolve this, we performed laboratory experiments with water from the Great Barrier Reef (Australia) to study the effects of temperature and dissolved organic matter sources on EEA and the proportion of dissolved EEA. We found that warming increases the rates of organic matter hydrolysis and reduces the proportion of dissolved relative to total EEA. This suggests a potential increase of the coupling between organic matter hydrolysis and heterotrophic activities with increasing ocean temperatures, although strongly dependent on the organic matter substrates available. Our study suggests that local differences in the organic matter composition in tropical coastal ecosystems will strongly affect the proportion of dissolved EEA in response to ocean warming.

  5. Obesity: A Venusian story of Paleolithic proportions

    Directory of Open Access Journals (Sweden)

    Krishna G Seshadri

    2012-01-01

    Full Text Available Art through the ages has been a marker of societal trends and fashion. Obesity is proscribed by physicians and almost reviled by today′s society. While Venus (Aphrodite continues to be the role model for those to aspire to free themselves from the clutches of obesity, Paleolithic humans had a different view of the perfect female form. Whether the Venus of Willendorf was a fashion symbol will be never answered, but the fact is that she remains testimony to the fact that obesity has been with us for several millennia.

  6. Planet Ocean

    Science.gov (United States)

    Afonso, Isabel

    2014-05-01

    A more adequate name for Planet Earth could be Planet Ocean, seeing that ocean water covers more than seventy percent of the planet's surface and plays a fundamental role in the survival of almost all living species. Actually, oceans are aqueous solutions of extraordinary importance due to its direct implications in the current living conditions of our planet and its potential role on the continuity of life as well, as long as we know how to respect the limits of its immense but finite capacities. We may therefore state that natural aqueous solutions are excellent contexts for the approach and further understanding of many important chemical concepts, whether they be of chemical equilibrium, acid-base reactions, solubility and oxidation-reduction reactions. The topic of the 2014 edition of GIFT ('Our Changing Planet') will explore some of the recent complex changes of our environment, subjects that have been lately included in Chemistry teaching programs. This is particularly relevant on high school programs, with themes such as 'Earth Atmosphere: radiation, matter and structure', 'From Atmosphere to the Ocean: solutions on Earth and to Earth', 'Spring Waters and Public Water Supply: Water acidity and alkalinity'. These are the subjects that I want to develop on my school project with my pupils. Geographically, our school is located near the sea in a region where a stream flows into the sea. Besides that, our school water comes from a borehole which shows that the quality of the water we use is of significant importance. This project will establish and implement several procedures that, supported by physical and chemical analysis, will monitor the quality of water - not only the water used in our school, but also the surrounding waters (stream and beach water). The samples will be collected in the borehole of the school, in the stream near the school and in the beach of Carcavelos. Several physical-chemical characteristics related to the quality of the water will

  7. Inputs from Indian rivers to the ocean: A synthesis

    Digital Repository Service at National Institute of Oceanography (India)

    DileepKumar, M.; George, M.D.; SenGupta, R.

    ). Fluxes of chemical substances to the Indian Ocean from these rivers are computed to a first approximation. The major ion contents are inversely proportional to the river runoff especially for the rivers entering the Arabian Sea. On an average Indian...

  8. Internal time marker (Q1) of the Cretaceous super chron in the Bay of Bengal - a new age constraint for the oceanic crust evolved between India and Elan Bank

    Science.gov (United States)

    Krishna, K. S.; Ismaiel, M.; Karlapati, S.; Saha, D.; Mishra, J.

    2014-12-01

    Analysis of marine magnetic data of the Bay of Bengal (BOB) led to suggest two different tectonic models for the evolution of lithosphere between India and East Antarctica. The first model explains the presence of M-series (M11 to M0) magnetic anomalies in BOB with a small room leaving for accommodating the crust evolved during the long Cretaceous Magnetic Quiet Period. Second model explains in other way that most part of the crust in BOB was evolved during the quite period together with the possible presence of oldest magnetic chron M1/ M0 in close vicinity of ECMI. It is with this perspective we have reinvestigated the existing and recently acquired magnetic data together with regional magnetic model of BOB for identification of new tectonic constraints, thereby to better understand the evolution of lithosphere. Analysis of magnetic data revealed the presence of spreading anomalies C33 and C34 in the vicinity of 8°N, and internal time marker (Q1) corresponding to the age 92 Ma at 12°N in a corridor between 85°E and Ninetyeast ridges. The new time marker and its location, indeed, become a point of reference and benchmark in BOB for estimating the age of oceanic crust towards ECMI. The magnetic model further reveals the presence of network of fracture zones (FZs) with different orientations. Between 85°E and Ninetyeast ridges, two near N-S FZs, approximately followed 87°E and 89.5°E are found to extend into BOB up to 12°N, from there the FZs reorient in N60°W direction and reach to the continental margin region. Along ECMI two sets of FZs are identified with a northern set oriented in N60°W and southern one in N40°W direction. This suggests that both north and south segments of the ECMI were evolved in two different tectonic settings. The bend in FZs marks the timing (92 Ma) of occurrence of first major plate reorganisation of the Indian Ocean and becomes a very critical constraint for understanding the plate tectonic process in early opening of the

  9. Ocean Uses: Hawaii (PROUA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Pacific Regional Ocean Uses Atlas (PROUA) Project is an innovative partnership between NOAA and the Bureau of Ocean Energy Management (BOEM) designed to...

  10. A New Chronology of Late Quaternary Sequences From the Central Arctic Ocean Based on "Extinction Ages" of Their Excesses in 231Pa and 230Th

    Science.gov (United States)

    Hillaire-Marcel, C.; Ghaleb, B.; de Vernal, A.; Maccali, J.; Cuny, K.; Jacobel, A.; Le Duc, C.; McManus, J.

    2017-12-01

    Merging the late Quaternary Arctic paleoceanography into the Earth's global climate history remains challenging due to the lack of robust marine chronostratigraphies. Over ridges notably, low and variable sedimentation rates, scarce biogenic remains ensuing from low productivity and/or poor preservation, and oxygen isotope and paleomagnetic records differing from global stacks represent major impediments. However, as illustrate here based on consistent records from Mendeleev-Alpha and Lomonosov Ridges, disequilibria between U-series isotopes can provide benchmark ages. In such settings, fluxes of the particle-reactive U-daughter isotopes 230Th and 231Pa from the water column, are not unequivocally linked to sedimentation rates, but rather to sea-ice rafting and brine production histories, thus to the development of sea-ice factories over shelves during intervals of high relative sea level. The excesses in 230Th and 231Pa over fractions supported by their parent U-isotopes, collapse down sedimentary sequences, due to radioactive decay, and provide radiometric benchmark ages of approximately 300 and 140 ka, respectively. These "extinction ages" point to mean sedimentation rates of ˜4.3 and ˜1.7 mm/ka, respectively, over the Lomonosov and Mendeleev Ridges, which are significantly lower than assumed in most recent studies, thus highlighting the need for revisiting current interpretations of Arctic lithostratigraphies in relation to the global-scale late Quaternary climatostratigraphy.

  11. Software of Seismic Proportions Promotes Enjoyable Learning

    Science.gov (United States)

    2005-01-01

    While working for NASA, Jack Sculley and Terry Brooks had a revelation. They wanted to find a novel and unique way to present the scientific principles of NASA research to the public, so as to not only enlighten, but entertain. Suddenly, their revelation morphed into something even grander. "Why stop at NASA?" they asked themselves. With this thought, Sculley and Brooks left NASA and set out to convey voluminous scientific findings from different organizations in the form of digital, interactive media that would enhance the exploration and adventure interests of people of all ages. Sculley, a former researcher at Ames Research Center, the Jet Propulsion Laboratory (JPL), and Apple, Inc. s and LucasFilm Ltd. s multimedia labs, and Brooks, a former public information officer at JPL and an Emmy award-winning documentary film producer, founded Seismic Entertainment in 1989 to communicate their "edutainment" ideas. The two acknowledge that NASA has provided much of the inspiration and content for Seismic Entertainment over the past decade and a half. Additionally, Sculley s experience as a virtual reality and Mars specialist and Brooks s experience creating NASA public access programs were significant to the San Francisco-based company s success. Its most recent project, "Inside NASA," provides virtual tours of NASA s field centers and allows for a comprehensive focus on the broad range of NASA programs for the benefit of the general public

  12. Ice Ages

    Indian Academy of Sciences (India)

    that the precession of the earth's orbit caused ice ages. The precession of the earth's orbit leads to changes in the time of the year at which ... than in the southern hemisphere. ..... small increase in ocean temperature implies a large increase in.

  13. Indian Ocean experiments with a coupled model

    Energy Technology Data Exchange (ETDEWEB)

    Wainer, I. [Sao Paulo, Univ. (Brazil). Dept. of Oceanography

    1997-03-01

    A coupled ocean-atmosphere model is used to investigate the equatorial Indian Ocean response to the seasonally varying monsoon winds. Special attention is given to the oceanic response to the spatial distribution and changes in direction of the zonal winds. The Indian Ocean is surrounded by an Asian land mass to the North and an African land mass to the West. The model extends latitudinally between 41 N and 41 S. The asymmetric atmospheric model is driven by a mass source/sink term that is proportional to the sea surface temperature (SST) over the oceans and the heat balance over the land. The ocean is modeled using the Anderson and McCreary reduced-gravity transport model that includes a prognostic equation for the SST. The coupled system is driven by the annual cycle as manifested by zonally symmetric and asymmetric land and ocean heating. They explored the different nature of the equatorial ocean response to various patterns of zonal wind stress forcing in order to isolate the impact of the remote response on the Somali current. The major conclusions are : i) the equatorial response is fundamentally different for easterlies and westerlies, ii) the impact of the remote forcing on the Somali current is a function of the annual cycle, iii) the size of the basin sets the phase of the interference of the remote forcing on the Somali current relative to the local forcing.

  14. Attending to relations: Proportional reasoning in 3- to 6-year-old children.

    Science.gov (United States)

    Hurst, Michelle A; Cordes, Sara

    2018-03-01

    When proportional information is pit against whole number numerical information, children often attend to the whole number information at the expense of proportional information (e.g., indicating 4/9 is greater than 3/5 because 4 > 3). In the current study, we presented younger (3- to 4-year-olds) and older (5- to 6-year-olds) children a task in which the proportional information was presented either continuously (units cannot be counted) or discretely (countable units; numerical information available). In the discrete conditions, older children showed numerical interference-responding based on the number of pieces instead of the proportion of pieces. However, older children easily overcame this poor strategy selection on discrete trials if they first had some experience with continuous, proportional strategies, suggesting this prevalent reliance on numerical information may be malleable. Younger children, on the other hand, showed difficulty with the proportion task, but showed evidence of proportional reasoning in a simplified estimation-style task, suggesting that younger children may still be developing their proportional and numerical skills in task-dependent ways. Lastly, across both age groups, performance on the proportional reasoning task in continuous contexts, but not discrete contexts, was related to more general analogical reasoning skills. Findings suggest that children's proportional reasoning abilities are actively developing between the ages of 3 and 6 and may depend on domain general reasoning skills. We discuss the implications for this work for both cognitive development and education. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

  15. Ocean Prediction Center

    Science.gov (United States)

    Social Media Facebook Twitter YouTube Search Search For Go NWS All NOAA Weather Analysis & Forecasts of Commerce Ocean Prediction Center National Oceanic and Atmospheric Administration Analysis & Unified Surface Analysis Ocean Ocean Products Ice & Icebergs NIC Ice Products NAIS Iceberg Analysis

  16. Anoxygenic photosynthesis modulated Proterozoic oxygen and sustained Earth's middle age

    Science.gov (United States)

    Johnston, D. T.; Wolfe-Simon, F.; Pearson, A.; Knoll, A. H.

    2009-01-01

    Molecular oxygen (O2) began to accumulate in the atmosphere and surface ocean ca. 2,400 million years ago (Ma), but the persistent oxygenation of water masses throughout the oceans developed much later, perhaps beginning as recently as 580–550 Ma. For much of the intervening interval, moderately oxic surface waters lay above an oxygen minimum zone (OMZ) that tended toward euxinia (anoxic and sulfidic). Here we illustrate how contributions to primary production by anoxygenic photoautotrophs (including physiologically versatile cyanobacteria) influenced biogeochemical cycling during Earth's middle age, helping to perpetuate our planet's intermediate redox state by tempering O2 production. Specifically, the ability to generate organic matter (OM) using sulfide as an electron donor enabled a positive biogeochemical feedback that sustained euxinia in the OMZ. On a geologic time scale, pyrite precipitation and burial governed a second feedback that moderated sulfide availability and water column oxygenation. Thus, we argue that the proportional contribution of anoxygenic photosynthesis to overall primary production would have influenced oceanic redox and the Proterozoic O2 budget. Later Neoproterozoic collapse of widespread euxinia and a concomitant return to ferruginous (anoxic and Fe2+ rich) subsurface waters set in motion Earth's transition from its prokaryote-dominated middle age, removing a physiological barrier to eukaryotic diversification (sulfide) and establishing, for the first time in Earth's history, complete dominance of oxygenic photosynthesis in the oceans. This paved the way for the further oxygenation of the oceans and atmosphere and, ultimately, the evolution of complex multicellular organisms. PMID:19805080

  17. PROPORTIONS AND HUMAN SCALE IN DAMASCENE COURTYARD HOUSES

    Directory of Open Access Journals (Sweden)

    M. Salim Ferwati

    2008-03-01

    Full Text Available Interior designers, architects, landscape architects, and even urban designers, agree that environment, as a form of non-verbal communication means, has a symbolic dimension to it. As for its aesthetic dimension, it seems that beauty is related to a certain proportion, partially and as a whole. Suitable proportion leaves a good impression upon the beholders, especially when it matches human proportion. That in fact was the underlining belief of LeCorbusier, according to which he developed his Modular concept. The study searches for a modular, or proportion, system that governs the design of Damascene traditional house. By geometrical and mathematical examinations of 28 traditional houses, it was found that a certain proportional relationship existed; however, these proportional relationships were not fixed ones. The study relied on analyzing the Iwan elevation as well as the inner courtyard proportion in relation to the building area. Charts, diagrams and tables were produced to summarize the results.

  18. Studying ocean acidification in the Arctic Ocean

    Science.gov (United States)

    Robbins, Lisa

    2012-01-01

    The U.S. Geological Survey (USGS) partnership with the U.S. Coast Guard Ice Breaker Healey and its United Nations Convention Law of the Sea (UNCLOS) cruises has produced new synoptic data from samples collected in the Arctic Ocean and insights into the patterns and extent of ocean acidification. This framework of foundational geochemical information will help inform our understanding of potential risks to Arctic resources due to ocean acidification.

  19. The mediation proportion: a structural equation approach for estimating the proportion of exposure effect on outcome explained by an intermediate variable

    DEFF Research Database (Denmark)

    Ditlevsen, Susanne; Christensen, Ulla; Lynch, John

    2005-01-01

    It is often of interest to assess how much of the effect of an exposure on a response is mediated through an intermediate variable. However, systematic approaches are lacking, other than assessment of a surrogate marker for the endpoint of a clinical trial. We review a measure of "proportion...... of several intermediate variables. Binary or categorical variables can be included directly through threshold models. We call this measure the mediation proportion, that is, the part of an exposure effect on outcome explained by a third, intermediate variable. Two examples illustrate the approach. The first...... example is a randomized clinical trial of the effects of interferon-alpha on visual acuity in patients with age-related macular degeneration. In this example, the exposure, mediator and response are all binary. The second example is a common problem in social epidemiology-to find the proportion...

  20. Increased production of cosmogenic 10Be recorded in oceanic sediment sequences: Information on the age, duration, and amplitude of the geomagnetic dipole moment minimum over the Matuyama-Brunhes transition

    Science.gov (United States)

    Simon, Quentin; Thouveny, Nicolas; Bourlès, Didier L.; Bassinot, Franck; Savranskaia, Tatiana; Valet, Jean-Pierre; Aster Team

    2018-05-01

    New high-resolution authigenic 10Be/9Be ratio (Be-ratio) records covering the last geomagnetic reversal, i.e. the Matuyama-Brunhes transition (MBT), have been obtained and set on a time scale using benthic δ18O (Cibicides wuellerstorfi) records. The geographic distribution of the four studied sites allows global comparison between the North Atlantic, Indian and Pacific Oceans. All Be-ratio records contain a two-fold increase triggered by the geomagnetic dipole moment (GDM) collapse associated with the MBT. The stratigraphic position of the Be-ratio spike, relative to marine isotope stages, allows establishment of a robust astrochronological framework for the MBT, anchoring its age between 778 and 766 ka (average mid-peaks at 772 ka), which is consistent with all other available 10Be-proxy records from marine, ice and loess archives. The global 10Be atmospheric production doubling represents an increase of more than 300 atoms m-2 s-1 that is compatible with the increased magnitude of atmospheric 10Be production obtained by simulations between the present GDM and a null-GDM. The minimum 10Be-derived GDM average computed for the 776-771 ka interval is 1.7 ± 0.4 ×1022 Am2, in agreement with model simulations and absolute paleointensities of transitional lava flows.

  1. The influence of craniofacial to standing height proportion on perceived attractiveness.

    Science.gov (United States)

    Naini, F B; Cobourne, M T; McDonald, F; Donaldson, A N A

    2008-10-01

    An idealised male image, based on Vitruvian Man, was created. The craniofacial height was altered from a proportion of 1/6 to 1/10 of standing height, creating 10 images shown in random order to 89 observers (74 lay people; 15 clinicians), who ranked the images from the most to the least attractive. The main outcome was the preference ranks of image attractiveness given by the observers. Linear regressions were used to assess what influences the choice for the most and the least attractive images, followed by a multivariate rank ordinal logistic regression to test the influence of age, gender, ethnicity and professional status of the observer. A craniofacial height to standing height proportion of 1/7.5 was perceived as the most attractive (36%), followed by a proportion of 1/8 (26%). The images chosen as most attractive by more than 10% of observers had a mean proportion of 1/7.8(min=1/7; max=1/8.5). The images perceived as most unattractive had a proportion of 1/6 and 1/10. The choice of images was not influenced by the age, gender, ethnicity or professional status of the observers. The ideal craniofacial height to standing height proportion is in the range 1/7 to 1/8.5. This finding should be considered when planning treatment to alter craniofacial or facial height.

  2. Pressure control valve using proportional electro-magnetic solenoid actuator

    International Nuclear Information System (INIS)

    Yun, So Nam; Ham, Young Bog; Park, Pyoung Won

    2006-01-01

    This paper presents an experimental characteristics of electro-hydraulic proportional pressure control valve. In this study, poppet and valve body which are assembled into the proportional solenoid were designed and manufactured. The constant force characteristics of proportional solenoid actuator in the control region should be independent of the plunger position in order to be used to control the valve position in the fluid flow control system. The stroke-force characteristics of the proportional solenoid actuator is determined by the shape (or parameters) of the control cone. In this paper, steady state and transient characteristics of the solenoid actuator for electro-hydraulic proportional valve are analyzed using finite element method and it is confirmed that the proportional solenoid actuator has a constant attraction force in the control region independently on the stroke position. The effects of the parameters such as control cone length, thickness and taper length are also discussed

  3. Development of extruded resistive plastic tubes for proportional chamber cathodes

    International Nuclear Information System (INIS)

    Kondo, K.

    1982-01-01

    Carbon mixed plastic tubes with resistivity of 10 3 approx. 10 4 Ωcm have been molded with an extrusion method and used for the d.c. cathode of a proportional counter and a multi-wire proportional chamber. The signal by gas multiplication was picked up from a strip r.f. cathode set outside the tube. The characteristics of the counter in the proportional and limited streamer modes have been studied

  4. Proportion of gynecologic cancer patients using complementary and alternative medicine.

    Science.gov (United States)

    Supoken, Amornrat; Chaisrisawatsuk, Thitima; Chumworathayi, Bandit

    2009-01-01

    Complementary and alternative medicine (CAM) for treatment of cancer and for supportive care of cancer patients must be clearly separated. There is encouraging evidence for CAM in the latter area, such as acupuncture and progressive muscle relaxation for chemotherapy-related nausea and vomiting, and aromatherapy for decreasing anxiety and increasing quality of life. However, there are limited data about CAM used by gynecologic cancer patients, especially in Thai women. Therefore, the authors aimed to investigate the proportion and types of CAM using in our gynecologic cancer patients. This cross-sectional survey was conducted between October to December, 2008. Totals of 50 admitted and 50 walk-in gynecologic cancer patients 1 month after diagnosis, aged more than 20 years and able to give informed consent, were selected for one-by-one interview by random walking survey. Among the 100 interviewed patients, aged 21-69 (mean=50.12), there were 46 cases of cervical cancers, 35 of ovarian cancers, 18 of endometrial cancers (two of these also had ovarian cancers), 2 of malignant gestational trophoblastic diseases, 1 of vulvar cancer, and 1 liver cancer (in a patient with ovarian cancer). Some 67% (95% CI, 57.8-76.2%) of them used CAM. As diet modifications, 11 used Chinese vegetarian, 8 common vegetarian, 5 Cheewajit, and 1 macrobiotics. Five of them used dietary supplements while colonic detoxification was emplyed in three. As herbal medicines, 27 used Thai herbs, 4 Chinese herbs, and 1 a herbal sauna. Twelve were receiving Thai massage. As exercises, 23 used aerobics and 5 stretching. Interestingly, 62 of them used Buddhist praying while only 3 employed native magic. The three most common forms of CAM used by our gynecologic cancer patients were Buddhist praying (62/67, 92.5%), followed by herbal medicines (27/67, 40.3%) and exercises (25/67, 37.3%).

  5. The Ocean Literacy Campaign

    Science.gov (United States)

    Schoedinger, S. E.; Strang, C.

    2008-12-01

    "Ocean Literacy is an understanding of the ocean's influence on you and your influence on the ocean." This simple statement captures the spirit of a conceptual framework supporting ocean literacy (COSEE et al., 2005). The framework comprises 7 essential principles and 44 fundamental concepts an ocean literate person would know (COSEE et al., 2005). The framework is the result of an extensive grassroots effort to reach consensus on (1) a definition for ocean literacy and (2) an articulation of the most important concepts to be understood by ocean-literate citizen (Cava et al., 2005). In the process of reaching consensus on these "big ideas" about the ocean, what began as a series of workshops has emerged as a campaign "owned" by an ever-expanding community of individuals, organizations and networks involved in developing and promoting the framework. The Ocean Literacy Framework has provided a common language for scientists and educators working together and serves as key guidance for the ocean science education efforts. This presentation will focus on the impact this Ocean Literacy Campaign has had to date as well as efforts underway to provide additional tools to enable educators and educational policy makers to further integrate teaching and learning about the ocean and our coasts into formal K-12 education and informal education. COSEE, National Geographic Society, NOAA, College of Exploration (2005). Ocean Literacy: The Essential Principles of Ocean Sciences Grades K-12, a jointly published brochure, URL: http://www.coexploration.org/oceanliteracy/documents/OceanLitChart.pdf Cava, F., S. Schoedinger , C. Strang, and P. Tuddenham (2005). Science Content and Standards for Ocean Literacy: A Report on Ocean Literacy, URL: http://www.coexploration.org/oceanliteracy/documents/OLit2004-05_Final_Report.pdf.

  6. Multiwire proportional chamber for Moessbauer spectroscopy: development and results

    International Nuclear Information System (INIS)

    Costa, M.S. da.

    1985-12-01

    A new Multiwere proportional Chamber designed for Moessbauer Spectroscopy is presented. This detector allows transmission backscattering experiments using either photons or electrons. The Moessbauer data acquisition system, partially developed for this work is described. A simple method for determining the frontier between true proportional and semi-proportional regions of operation in gaseous detectors is proposed. The study of the tertiary gas mixture He-Ar-CH 4 leads to a straight forward way of energy calibration of the electron spectra. Moessbauer spectra using Fe-57 source are presented. In particular those obtained with backsattered electrons show the feasibility of depth selective analysis with gaseous proportional counters. (author) [pt

  7. 75 FR 18778 - Safety Zone; Ocean City Air Show 2010, Atlantic Ocean, Ocean City, MD

    Science.gov (United States)

    2010-04-13

    ...-AA00 Safety Zone; Ocean City Air Show 2010, Atlantic Ocean, Ocean City, MD AGENCY: Coast Guard, DHS... zone on the Atlantic Ocean in the vicinity of Ocean City, Maryland to support the Ocean City Air Show. This action is intended to restrict vessel traffic movement on the Atlantic Ocean to protect mariners...

  8. Ocean Disposal Site Monitoring

    Science.gov (United States)

    EPA is responsible for managing all designated ocean disposal sites. Surveys are conducted to identify appropriate locations for ocean disposal sites and to monitor the impacts of regulated dumping at the disposal sites.

  9. People and Oceans.

    Science.gov (United States)

    NatureScope, 1988

    1988-01-01

    Discusses people's relationship with oceans, focusing on ocean pollution, use, and protective measures of the sea and its wildlife. Activities included are "Mythical Monsters"; "Globetrotters"; "Plastic in the Sea"; and "Sea of Many Uses." (RT)

  10. Ocean Sediment Thickness Contours

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean sediment thickness contours in 200 meter intervals for water depths ranging from 0 - 18,000 meters. These contours were derived from a global sediment...

  11. Ocean Robotic Networks

    Energy Technology Data Exchange (ETDEWEB)

    Schofield, Oscar [Rutgers University

    2012-05-23

    We live on an ocean planet which is central to regulating the Earth’s climate and human society. Despite the importance of understanding the processes operating in the ocean, it remains chronically undersampled due to the harsh operating conditions. This is problematic given the limited long term information available about how the ocean is changing. The changes include rising sea level, declining sea ice, ocean acidification, and the decline of mega fauna. While the changes are daunting, oceanography is in the midst of a technical revolution with the expansion of numerical modeling techniques, combined with ocean robotics. Operating together, these systems represent a new generation of ocean observatories. I will review the evolution of these ocean observatories and provide a few case examples of the science that they enable, spanning from the waters offshore New Jersey to the remote waters of the Southern Ocean.

  12. Ocean Uses: California

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Ocean Uses Atlas Project is an innovative partnership between NOAA's National Marine Protected Areas Center and Marine Conservation Biology Institute. The...

  13. Ethane ocean on Titan

    Science.gov (United States)

    Lunine, J. I.; Stevenson, D. J.; Yung, Y.L.

    1983-01-01

    Voyager I radio occultation data is employed to develop a qualitative model of an ethane ocean on Titan. It is suggested that the ocean contains 25 percent CH4 and that the ocean is in dynamic equilibrium with an N2 atmosphere. Previous models of a CH4 ocean are discounted due to photolysis rates of CH4 gas. Tidal damping of Titan's orbital eccentricity is taken as evidence for an ocean layer approximately 1 km deep, with the ocean floor being covered with a solid C2H2 layer 100 to 200 m thick. The photolytic process disrupting the CH4, if the estimates of the oceanic content of CH4 are correct, could continue for at least one billion years. Verification of the model is dependent on detecting CH4 clouds in the lower atmosphere, finding C2H6 saturation in the lower troposphere, or obtaining evidence of a global ocean.

  14. Regional Ocean Data Assimilation

    KAUST Repository

    Edwards, Christopher A.; Moore, Andrew M.; Hoteit, Ibrahim; Cornuelle, Bruce D.

    2015-01-01

    This article reviews the past 15 years of developments in regional ocean data assimilation. A variety of scientific, management, and safety-related objectives motivate marine scientists to characterize many ocean environments, including coastal

  15. Ocean Disposal Sites

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — In 1972, Congress enacted the Marine Protection, Research, and Sanctuaries Act (MPRSA, also known as the Ocean Dumping Act) to prohibit the dumping of material into...

  16. Ocean Station Vessel

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Ocean Station Vessels (OSV) or Weather Ships captured atmospheric conditions while being stationed continuously in a single location. While While most of the...

  17. California Ocean Uses Atlas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This dataset is a result of the California Ocean Uses Atlas Project: a collaboration between NOAA's National Marine Protected Areas Center and Marine Conservation...

  18. Ocean Acidification Product Suite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Scientists within the ACCRETE (Acidification, Climate, and Coral Reef Ecosystems Team) Lab of AOML_s Ocean Chemistry and Ecosystems Division (OCED) have constructed...

  19. X-ray proportional counter for the Viking Lander

    International Nuclear Information System (INIS)

    Glesius, F.L.; Kroon, J.C.; Castro, A.J.; Clark, B.C.

    1978-01-01

    A set of four sealed proportional counters with optimized energy response is employed in the X-ray fluorescence spectrometer units aboard the two Viking Landers. The instruments have provided quantitative elemental analyses of soil samples taken from the Martian surface. This paper discusses the design and development of these miniature proportional counters, and describes their performance on Mars

  20. Putative golden proportions as predictors of facial esthetics in adolescents.

    Science.gov (United States)

    Kiekens, Rosemie M A; Kuijpers-Jagtman, Anne Marie; van 't Hof, Martin A; van 't Hof, Bep E; Maltha, Jaap C

    2008-10-01

    In orthodontics, facial esthetics is assumed to be related to golden proportions apparent in the ideal human face. The aim of the study was to analyze the putative relationship between facial esthetics and golden proportions in white adolescents. Seventy-six adult laypeople evaluated sets of photographs of 64 adolescents on a visual analog scale (VAS) from 0 to 100. The facial esthetic value of each subject was calculated as a mean VAS score. Three observers recorded the position of 13 facial landmarks included in 19 putative golden proportions, based on the golden proportions as defined by Ricketts. The proportions and each proportion's deviation from the golden target (1.618) were calculated. This deviation was then related to the VAS scores. Only 4 of the 19 proportions had a significant negative correlation with the VAS scores, indicating that beautiful faces showed less deviation from the golden standard than less beautiful faces. Together, these variables explained only 16% of the variance. Few golden proportions have a significant relationship with facial esthetics in adolescents. The explained variance of these variables is too small to be of clinical importance.

  1. Putative golden proportions as predictors of facial esthetics in adolescents.

    NARCIS (Netherlands)

    Kiekens, R.M.A.; Kuijpers-Jagtman, A.M.; Hof, M.A. van 't; Hof, B.E. van 't; Maltha, J.C.

    2008-01-01

    INTRODUCTION: In orthodontics, facial esthetics is assumed to be related to golden proportions apparent in the ideal human face. The aim of the study was to analyze the putative relationship between facial esthetics and golden proportions in white adolescents. METHODS: Seventy-six adult laypeople

  2. The principle of proportionality and European contract law

    NARCIS (Netherlands)

    Cauffman, C.; Rutgers, J.; Sirena, P.

    2015-01-01

    The paper investigates the role of the principle of proportionality within contract law, in balancing the rights and obligations of the contracting parties. It illustrates that the principle of proportionality is one of the general principles which govern contractual relations, and as such it is an

  3. The Improved Estimation of Ratio of Two Population Proportions

    Science.gov (United States)

    Solanki, Ramkrishna S.; Singh, Housila P.

    2016-01-01

    In this article, first we obtained the correct mean square error expression of Gupta and Shabbir's linear weighted estimator of the ratio of two population proportions. Later we suggested the general class of ratio estimators of two population proportions. The usual ratio estimator, Wynn-type estimator, Singh, Singh, and Kaur difference-type…

  4. Attention Modulation by Proportion Congruency: The Asymmetrical List Shifting Effect

    Science.gov (United States)

    Abrahamse, Elger L.; Duthoo, Wout; Notebaert, Wim; Risko, Evan F.

    2013-01-01

    Proportion congruency effects represent hallmark phenomena in current theorizing about cognitive control. This is based on the notion that proportion congruency determines the relative levels of attention to relevant and irrelevant information in conflict tasks. However, little empirical evidence exists that uniquely supports such an attention…

  5. 16 CFR 240.9 - Proportionally equal terms.

    Science.gov (United States)

    2010-01-01

    ... 16 Commercial Practices 1 2010-01-01 2010-01-01 false Proportionally equal terms. 240.9 Section 240.9 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES FOR ADVERTISING ALLOWANCES AND OTHER MERCHANDISING PAYMENTS AND SERVICES § 240.9 Proportionally equal terms. (a...

  6. Regional Ocean Data Assimilation

    KAUST Repository

    Edwards, Christopher A.

    2015-01-03

    This article reviews the past 15 years of developments in regional ocean data assimilation. A variety of scientific, management, and safety-related objectives motivate marine scientists to characterize many ocean environments, including coastal regions. As in weather prediction, the accurate representation of physical, chemical, and/or biological properties in the ocean is challenging. Models and observations alone provide imperfect representations of the ocean state, but together they can offer improved estimates. Variational and sequential methods are among the most widely used in regional ocean systems, and there have been exciting recent advances in ensemble and four-dimensional variational approaches. These techniques are increasingly being tested and adapted for biogeochemical applications.

  7. Which Mixed-Member Proportional Electoral Formula Fits You Best? Assessing the Proportionality Principle of Positive Vote Transfer Systems

    DEFF Research Database (Denmark)

    Bochsler, Daniel

    2014-01-01

    Mixed-member proportional systems (MMP) are a family of electoral systems which combine district-based elections with a proportional seat allocation. Positive vote transfer systems belong to this family. This article explains why they might be better than their siblings, and examines under which ...

  8. Computational Ocean Acoustics

    CERN Document Server

    Jensen, Finn B; Porter, Michael B; Schmidt, Henrik

    2011-01-01

    Since the mid-1970s, the computer has played an increasingly pivotal role in the field of ocean acoustics. Faster and less expensive than actual ocean experiments, and capable of accommodating the full complexity of the acoustic problem, numerical models are now standard research tools in ocean laboratories. The progress made in computational ocean acoustics over the last thirty years is summed up in this authoritative and innovatively illustrated new text. Written by some of the field's pioneers, all Fellows of the Acoustical Society of America, Computational Ocean Acoustics presents the latest numerical techniques for solving the wave equation in heterogeneous fluid–solid media. The authors discuss various computational schemes in detail, emphasizing the importance of theoretical foundations that lead directly to numerical implementations for real ocean environments. To further clarify the presentation, the fundamental propagation features of the techniques are illustrated in color. Computational Ocean A...

  9. The proportionate value of proportionality in palliative sedation.

    Science.gov (United States)

    Berger, Jeffrey T

    2014-01-01

    Proportionality, as it pertains to palliative sedation, is the notion that sedation should be induced at the lowest degree effective for symptom control, so that the patient's consciousness may be preserved. The pursuit of proportionality in palliative sedation is a widely accepted imperative advocated in position statements and guidelines on this treatment. The priority assigned to the pursuit of proportionality, and the extent to which it is relevant for patients who qualify for palliative sedation, have been overstated. Copyright 2014 The Journal of Clinical Ethics. All rights reserved.

  10. An integrated photosensor readout for gas proportional scintillation counters

    International Nuclear Information System (INIS)

    Lopes, J.A.M.; Santos, J.M.F. dos; Conde, C.A.N.

    1996-01-01

    A xenon gas proportional scintillation counter has been instrumented with a novel photosensor that replaces the photomultiplier tube normally used to detect the VUV secondary scintillation light. In this implementation, the collection grid of a planar gas proportional scintillation counter also functions as a multiwire proportional chamber to amplify and detect the photoelectrons emitted by a reflective CsI photocathode in direct contact with the xenon gas. This integrated concept combines greater simplicity, compactness, and ruggedness (no optical window is used) with low power consumption. An energy resolution of 12% was obtained for 59.6 keV x-rays

  11. The pole tide in deep oceans

    Science.gov (United States)

    Dickman, S. R.

    1990-01-01

    The fluid-dynamical theory of the pole tide is examined by describing the oceanic response to the Chandler wobble and assessing its implications for mantle anelasticity and low-frequency ocean dynamics. The Laplace tide equations accounting for bottom friction are given, and a spherical harmonic approach is delineated in which the time-independent portion of the tide height is expanded. Pole-tide height and related inertia products are linearly proportional to wobble amplitude, and the final equations are modified to account for mantle elasticity and oceanic loading. Results for pole tide effects are given for various earth models with attention to the role of boundary constraints. A dynamic effect is identified which lengthens the Chandler period by about 1 day more than static lengthening, a contribution that suggests a vigorous low-frequency response. The values derived are shown to agree with previous models that do not incorporate the effects of the pole tide.

  12. Validity of mathematical proportions in maxillary anterior teeth among Bangladeshi population

    Directory of Open Access Journals (Sweden)

    Monwarul Aziz

    2017-01-01

    Full Text Available Objective: To investigate the existence and suitability of mathematical proportions between the widths of maxillary anterior teeth in Bangladeshi population having an esthetic smile, with the aid of digital photographs and computer analysis. Place of Study: The study was conducted at the Department of Orthodontics and Dentofacial Orthopedics of Dhaka Dental College and Hospital, Dhaka. Period of Study: The study was conducted from April 2016 to September 2016. Sample Selection: The study samples collected from Students of Dhaka Dental College, Mirpur-14, Dhaka, Bangladesh, with age limit 18–35 years. Materials and Methods: Standardized frontal images of 100 dental students of Dhaka Dental College were captured. All the images were downloaded to a personal computer, and width of each tooth was measured by the scale tool of Photoshop CS version 8.0. All the data were analyzed (through standard statistical method using Statistical Package for Social Science Software version 20 (IBM Corp., USA. Results: The golden proportion existed in 17% of the perceived width ratios of lateral incisor to central incisor and 4% of the width ratios of canine to lateral incisor in natural dentition. Sixty-six percent lateral incisors are following the golden percentage, but only 7% central incisors and 21% canines are following the golden percentage. The recurring esthetic dental (RED proportion existed in only 4% of participants. Conclusions: The golden proportion, golden percentage, and the RED proportion cannot be used as constant proportions to create a harmonious proportion throughout the width of maxillary anterior teeth. The adjusted golden percentage might serve as a guideline to create harmonious proportions in maxillary anterior teeth for Bangladeshi population.

  13. A reduced feedback proportional fair multiuser scheduling scheme

    KAUST Repository

    Shaqfeh, Mohammad; Alnuweiri, Hussein M.; Alouini, Mohamed-Slim

    2011-01-01

    . A slight reduction in the prospected multiuser diversity gains is an acceptable trade-off for great savings in terms of required channel-state-information feedback messages. In this work, we propose a novel proportional fair multiuser switched

  14. DC motor proportional control system for orthotic devices

    Science.gov (United States)

    Blaise, H. T.; Allen, J. R.

    1972-01-01

    Multi-channel proportional control system for operation of dc motors for use with externally-powered orthotic arm braces is described. Components of circuitry and principles of operation are described. Schematic diagram of control circuit is provided.

  15. Proportional feedback control of laminar flow over a hemisphere

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jung Il [Dept. of Mechanical Engineering, Ajou University, Suwon (Korea, Republic of); Son, Dong Gun [Severe Accident and PHWR Safety Research Division, Korea Atomic Energy Research Institute (KAERI), Daejeon (Korea, Republic of)

    2016-08-15

    In the present study, we perform a proportional feedback control of laminar flow over a hemisphere at Re = 300 to reduce its lift fluctuations by attenuating the strength of the vortex shedding. As a control input, blowing/suction is distributed on the surface of hemisphere before the separation, and its strength is linearly proportional to the transverse velocity at a sensing location in the centerline of the wake. The sensing location is determined based on a correlation function between the lift force and the time derivative of sensing velocity. The optimal proportional gains for the proportional control are obtained for the sensing locations considered. The present control successfully attenuates the velocity fluctuations at the sensing location and three dimensional vertical structures in the wake, resulting in the reduction of lift fluctuations of hemisphere.

  16. Operability test report for 211BA flow proportional sampler

    International Nuclear Information System (INIS)

    Weissenfels, R.D.

    1995-01-01

    This operability report will verify that the 211-BA flow proportional sampler functions as intended by design. The sampler was installed by Project W-007H and is part of BAT/AKART for the BCE liquid effluent stream

  17. Enhanced deep ocean ventilation and oxygenation with global warming

    Science.gov (United States)

    Froelicher, T. L.; Jaccard, S.; Dunne, J. P.; Paynter, D.; Gruber, N.

    2014-12-01

    Twenty-first century coupled climate model simulations, observations from the recent past, and theoretical arguments suggest a consistent trend towards warmer ocean temperatures and fresher polar surface oceans in response to increased radiative forcing resulting in increased upper ocean stratification and reduced ventilation and oxygenation of the deep ocean. Paleo-proxy records of the warming at the end of the last ice age, however, suggests a different outcome, namely a better ventilated and oxygenated deep ocean with global warming. Here we use a four thousand year global warming simulation from a comprehensive Earth System Model (GFDL ESM2M) to show that this conundrum is a consequence of different rates of warming and that the deep ocean is actually better ventilated and oxygenated in a future warmer equilibrated climate consistent with paleo-proxy records. The enhanced deep ocean ventilation in the Southern Ocean occurs in spite of increased positive surface buoyancy fluxes and a constancy of the Southern Hemisphere westerly winds - circumstances that would otherwise be expected to lead to a reduction in deep ocean ventilation. This ventilation recovery occurs through a global scale interaction of the Atlantic Meridional Overturning Circulation undergoing a multi-centennial recovery after an initial century of transient decrease and transports salinity-rich waters inform the subtropical surface ocean to the Southern Ocean interior on multi-century timescales. The subsequent upwelling of salinity-rich waters in the Southern Ocean strips away the freshwater cap that maintains vertical stability and increases open ocean convection and the formation of Antarctic Bottom Waters. As a result, the global ocean oxygen content and the nutrient supply from the deep ocean to the surface are higher in a warmer ocean. The implications for past and future changes in ocean heat and carbon storage will be discussed.

  18. 39Ar/Ar measurements using ultra-low background proportional counters

    International Nuclear Information System (INIS)

    Hall, Jeter; Aalseth, Craig E.; Bonicalzi, Ricco M.; Brandenberger, Jill M.; Day, Anthony R.; Humble, Paul H.; Mace, Emily K.; Panisko, Mark E.; Seifert, Allen

    2016-01-01

    Age-dating groundwater and seawater using the 39 Ar/Ar ratio is an important tool to understand water mass-flow rates and mean residence time. Low-background proportional counters developed at Pacific Northwest National Laboratory use mixtures of argon and methane as counting gas. We demonstrate sensitivity to 39 Ar by comparing geological (ancient) argon recovered from a carbon dioxide gas well and commercial argon. The demonstrated sensitivity to the 39 Ar/Ar ratio is sufficient to date water masses as old as 1000 years. - Highlights: • 39 Ar/Ar age dating is important for understanding environmental water migration. • Ultra low background proportional counters have been developed. • 39 Ar is detected in atmospheric argon at a rate of 70.3 counts per day. The demonstrated background is 166 counts per day. • Age dating is possible for water with underground residence time of up to 1000 years.

  19. A parsimonious model for the proportional control valve

    OpenAIRE

    Elmer, KF; Gentle, CR

    2001-01-01

    A generic non-linear dynamic model of a direct-acting electrohydraulic proportional solenoid valve is presented. The valve consists of two subsystems-s-a spool assembly and one or two unidirectional proportional solenoids. These two subsystems are modelled separately. The solenoid is modelled as a non-linear resistor-inductor combination, with inductance parameters that change with current. An innovative modelling method has been used to represent these components. The spool assembly is model...

  20. Reduction of degraded events in miniaturized proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Plaga, R.; Kirsten, T. (Max Planck Inst. fuer Kernphysik, Heidelberg (Germany))

    1991-11-15

    A method to reduce the number of degraded events in miniaturized proportional counters is described. A shaping of the outer cathode leads to a more uniform gas gain along the counter axis. The method is useful in situations in which the total number of decay events is very low. The effects leading to degraded events are studied theoretically and experimentally. The usefulness of the method is demonstrated by using it for the proportional counter of the GALLEX solar neutrino experiment. (orig.).

  1. Contrasting effects of climate change in continental vs. oceanic environments on population persistence and microevolution of Atlantic salmon.

    Science.gov (United States)

    Piou, Cyril; Prévost, Etienne

    2013-03-01

    Facing climate change (CC), species are prone to multiple modifications in their environment that can lead to extinction, migration or adaptation. Identifying the role and interplay of different potential stressors becomes a key question. Anadromous fishes will be exposed to both river and oceanic habitat changes. For Atlantic salmon, the river water temperature, river flow and oceanic growth conditions appear as three main stressing factors. They could act on population dynamics or as selective forces on life-history pathways. Using an individual-based demo-genetic model, we assessed the effects of these factors (1) to compare risks of extinction resulting from CC in river and ocean, and (2) to assess CC effects on life-history pathways including the evolution of underlying genetic control of phenotypic plasticity. We focused on Atlantic salmon populations from Southern Europe for a time horizon of three decades. We showed that CC in river alone should not lead to extinction of Southern European salmon populations. In contrast, the reduced oceanic growth appeared as a significant threat for population persistence. An increase in river flow amplitude increased the risk of local extinction in synergy with the oceanic effects, but river temperature rise reduced this risk. In terms of life-history modifications, the reduced oceanic growth increased the age of return of individuals through plastic and genetic responses. The river temperature rise increased the proportion of sexually mature parr, but the genetic evolution of the maturation threshold lowered the maturation rate of male parr. This was identified as a case of environmentally driven plastic response that masked an underlying evolutionary response of plasticity going in the opposite direction. We concluded that to counteract oceanic effects, river flow management represented the sole potential force to reduce the extinction probability of Atlantic salmon populations in Southern Europe, although this might

  2. Golden proportion assessment between maxillary and mandibular teeth on Indian population

    Science.gov (United States)

    Kumar, Vaikunth Vijay; Rangarajan, Vedantham

    2012-01-01

    PURPOSE This study evaluated the existence of golden proportion between the widths of the maxillary and mandibular anterior teeth in Indian population. MATERIALS AND METHODS The clinical tooth width measurements were recorded with the digital vernier calipers on 576 patients of both sexes in the age group of 21 - 30 years. Flexible ruler was used to determine the width of maxillary and mandibular anterior teeth on the patients by the same operator. The data obtained was statistically analyzed using paired student t-test (α=.05). RESULTS The golden proportion was not found between the width of the right central and lateral incisors in 53% of women and 47% of men. The results revealed the golden percentage was rather inconstant in terms of relative tooth width. CONCLUSION The golden proportion is an inappropriate method to relate the successive widths of the maxillary anterior teeth in Indian population. PMID:22737310

  3. The Southern Ocean Observing System

    OpenAIRE

    Rintoul, Stephen R.; Meredith, Michael P.; Schofield, Oscar; Newman, Louise

    2012-01-01

    The Southern Ocean includes the only latitude band where the ocean circles the earth unobstructed by continental boundaries. This accident of geography has profound consequences for global ocean circulation, biogeochemical cycles, and climate. The Southern Ocean connects the ocean basins and links the shallow and deep limbs of the overturning circulation (Rintoul et al., 2001). The ocean's capacity to moderate the pace of climate change is therefore influenced strongly by the Southern Ocean's...

  4. Against proportional shortfall as a priority-setting principle.

    Science.gov (United States)

    Altmann, Samuel

    2018-05-01

    As the demand for healthcare rises, so does the need for priority setting in healthcare. In this paper, I consider a prominent priority-setting principle: proportional shortfall. My purpose is to argue that proportional shortfall, as a principle, should not be adopted. My key criticism is that proportional shortfall fails to consider past health.Proportional shortfall is justified as it supposedly balances concern for prospective health while still accounting for lifetime health, even though past health is deemed irrelevant. Accounting for this lifetime perspective means that the principle may indirectly consider past health by accounting for how far an individual is from achieving a complete, healthy life. I argue that proportional shortfall does not account for this lifetime perspective as it fails to incorporate the fair innings argument as originally claimed, undermining its purported justification.I go on to demonstrate that the case for ignoring past health is weak, and argue that past health is at least sometimes relevant for priority-setting decisions. Specifically, when an individual's past health has a direct impact on current or future health, and when one individual has enjoyed significantly more healthy life years than another.Finally, I demonstrate that by ignoring past illnesses, even those entirely unrelated to their current illness, proportional shortfall can lead to instances of double jeopardy, a highly problematic implication. These arguments give us reason to reject proportional shortfall. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  5. Ejecta from Ocean Impacts

    Science.gov (United States)

    Kyte, Frank T.

    2003-01-01

    Numerical simulations of deep-ocean impact provide some limits on the size of a projectile that will not mix with the ocean floor during a deep-ocean impact. For a vertical impact at asteroidal velocities (approx. 20 km/s), mixing is only likely when the projectile diameter is greater than 112 of the water depth. For oblique impacts, even larger projectiles will not mix with ocean floor silicates. Given the typical water depths of 4 to 5 km in deep-ocean basins, asteroidal projectiles with diameters as large as 2 or 3 km may commonly produce silicate ejecta that is composed only of meteoritic materials and seawater salts. However, the compressed water column beneath the projectile can still disrupt and shock metamorphose the ocean floor. Therefore, production of a separate, terrestrial ejecta component is not ruled out in the most extreme case. With increasing projectile size (or energy) relative to water depths, there must be a gradation between oceanic impacts and more conventional continental impacts. Given that 60% of the Earth's surface is covered by oceanic lithosphere and 500 m projectiles impact the Earth on 10(exp 5) y timescales, there must be hundreds of oceanic impact deposits in the sediment record awaiting discovery.

  6. The golden proportion in facial soft-tissues of Vietnamese females.

    Science.gov (United States)

    Nguyen, Minh Son; Saag, Mare; Le, Van Nho; Nguyen, Thuy Trang; Nguyen, Bui Bao Tien; Jagomägi, Triin

    2016-01-01

    Objective of the current study was to evaluate proportions of frontal facial soft-tissues of Vietnamese females correspond to the golden proportion (GP). Sixty frontal facial photographs of Vietnamese female students aged 19 years were selected. The selected participants had symmetrical face, a Class I relationship occlusion, complete lip closure, and no history of trauma and orthodontic treatment. The photographic record was set-up with a white backdrop, fill light, a reflector, a camera Canon 650D and subjects were asked to sit in a standard position. Trichion (TR), Temporal soft tissue (TS), Lateral canthus (LC), Lateral nasal (LN), Chilion (CH), and Menton (ME) point were used for photometric measurements on CorelDRAW Graphic X3 software. The vertical facial proportions (mean, percentage compared with GP) were significantly higher than the GP including: LC-CH:CH-ME (1.661, 102%), LN-ME:LC-LN (1.729, 106%), TR-ME:LC-ME (1.739, 107%), TR-LN:LN-ME (1.759, 108%). Whereas TR-ME:LN-ME; CH-ME:LN-CH; LC-LN:LN-CH had ratios of 84% - 92% and were significantly smaller in comparison with GP. The horizontal facial proportions of CHR-L:LNR-L, LCR-L:CHR-L and TSR-L:LCR-L deviated from the GP with mean values of 1.221, 1.922 and 1.229, respectively. The new mean values of TR-ME:LC-ME (1.733), TR-LN:LN-ME (1.732), LC-ME:TR-LC (1.374), CH-ME:LN-CH (1.524), which were predictable changes in proportions, can be significantly converged to the GP if LC-CH:CH-ME is equal to the GP. Soft-tissue facial proportions of Vietnamese females did not correspond to the GP. Changing the lower third face may create harmony vertical facial proportions.

  7. Proportioning and performance evaluation of self-consolidating concrete

    Science.gov (United States)

    Wang, Xuhao

    A well-proportioned self-consolidating concrete (SCC) mixture can be achieved by controlling the aggregate system, paste quality, and paste quantity. The work presented in this dissertation involves an effort to study and improve particle packing of the concrete system and reduce the paste quantity while maintaining concrete quality and performance. This dissertation is composed of four papers resulting from the study: (1) Assessing Particle Packing Based Self-Consolidating Concrete Mix Design; (2) Using Paste-To-Voids Volume Ratio to Evaluate the Performance of Self-Consolidating Concrete Mixtures; (3) Image Analysis Applications on Assessing Static Stability and Flowability of Self-Consolidating Concrete, and (4) Using Ultrasonic Wave Propagation to Monitor Stiffening Process of Self-Consolidating Concrete. Tests were conducted on a large matrix of SCC mixtures that were designed for cast-in-place bridge construction. The mixtures were made with different aggregate types, sizes, and different cementitious materials. In Paper 1, a modified particle-packing based mix design method, originally proposed by Brouwers (2005), was applied to the design of self-consolidating concrete (SCC) mixs. Using this method, a large matrix of SCC mixes was designed to have a particle distribution modulus (q) ranging from 0.23 to 0.29. Fresh properties (such as flowability, passing ability, segregation resistance, yield stress, viscosity, set time and formwork pressure) and hardened properties (such as compressive strength, surface resistance, shrinkage, and air structure) of these concrete mixes were experimentally evaluated. In Paper 2, a concept that is based on paste-to-voids volume ratio (Vpaste/Vvoids) was employed to assess the performance of SCC mixtures. The relationship between excess paste theory and Vpaste/Vvoids was investigated. The workability, flow properties, compressive strength, shrinkage, and surface resistivity of SCC mixtures were determined at various ages

  8. Proportional and functional analogical reasoning in normal and language-impaired children.

    Science.gov (United States)

    Nippold, M A; Erskine, B J; Freed, D B

    1988-11-01

    Teachers often use analogies in classroom settings to clarify new concepts for their students. However, analogies may inadvertently confuse the youngster who has difficulty identifying the one-to-one comparisons underlying them. Although analogical reasoning has been studied extensively in normal children, no information was available concerning this construct in children having a specific language impairment. Thus, it was unknown to what extent they might be deficient in analogical reasoning. Therefore, in the present study, 20 children ages 6-8 years (mean age = 7:6) having normal nonverbal intelligence but deficits in language comprehension were administered tasks of verbal and perceptual proportional analogical reasoning and a problem-solving task of functional analogical reasoning. Compared to a normal-language control group matched on the basis of chronological age and sex, the language-impaired group was deficient in all three tasks of analogical reasoning. However, when the factor of nonverbal intelligence was controlled statistically, the differences between the groups on each of the tasks were removed. Additional findings were that verbal proportional analogical reasoning was significantly correlated to perceptual proportional analogical reasoning and to functional analogical reasoning. Implications for assessment and intervention with young school-age language-impaired children are discussed.

  9. The principle of proportionality revisited: interpretations and applications.

    Science.gov (United States)

    Hermerén, Göran

    2012-11-01

    The principle of proportionality is used in many different contexts. Some of these uses and contexts are first briefly indicated. This paper focusses on the use of this principle as a moral principle. I argue that under certain conditions the principle of proportionality is helpful as a guide in decision-making. But it needs to be clarified and to be used with some flexibility as a context-dependent principle. Several interpretations of the principle are distinguished, using three conditions as a starting point: importance of objective, relevance of means, and most favourable option. The principle is then tested against an example, which suggests that a fourth condition, focusing on non-excessiveness, needs to be added. I will distinguish between three main interpretations of the principle, some primarily with uses in research ethics, others with uses in other areas of bioethics, for instance in comparisons of therapeutic means and ends. The relations between the principle of proportionality and the precautionary principle are explored in the following section. It is concluded that the principles are different and may even clash. In the next section the principle of proportionality is applied to some medical examples drawn from research ethics and bioethics. In concluding, the status of the principle of proportionality as a moral principle is discussed. What has been achieved so far and what remains to be done is finally summarized.

  10. Our Changing Oceans: All about Ocean Acidification

    International Nuclear Information System (INIS)

    Rickwood, Peter

    2013-01-01

    The consequences of ocean acidification are global in scale. More research into ocean acidification and its consequences is needed. It is already known, for example, that there are regional differences in the vulnerability of fisheries to acidification. The combination of other factors, such as global warming, the destruction of habitats, overfishing and pollution, need to be taken into account when developing strategies to increase the marine environment’s resilience. Among steps that can be taken to reduce the impact is better protection of marine coastal ecosystems, such as mangrove swamps and seagrass meadows, which will help protect fisheries. This recommendation was one of the conclusions of a three-day workshop attended by economists and scientists and organized by the IAEA and the Centre Scientifique de Monaco in November 2012. In their recommendations the workshop also stressed that the impact of increasing ocean acidity must be taken into account in the management of fisheries, particularly where seafood is a main dietary source

  11. Blue ocean strategy.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2004-10-01

    Despite a long-term decline in the circus industry, Cirque du Soleil profitably increased revenue 22-fold over the last ten years by reinventing the circus. Rather than competing within the confines of the existing industry or trying to steal customers from rivals, Cirque developed uncontested market space that made the competition irrelevant. Cirque created what the authors call a blue ocean, a previously unknown market space. In blue oceans, demand is created rather than fought over. There is ample opportunity for growth that is both profitable and rapid. In red oceans--that is, in all the industries already existing--companies compete by grabbing for a greater share of limited demand. As the market space gets more crowded, prospects for profits and growth decline. Products turn into commodities, and increasing competition turns the water bloody. There are two ways to create blue oceans. One is to launch completely new industries, as eBay did with online auctions. But it's much more common for a blue ocean to be created from within a red ocean when a company expands the boundaries of an existing industry. In studying more than 150 blue ocean creations in over 30 industries, the authors observed that the traditional units of strategic analysis--company and industry--are of limited use in explaining how and why blue oceans are created. The most appropriate unit of analysis is the strategic move, the set of managerial actions and decisions involved in making a major market-creating business offering. Creating blue oceans builds brands. So powerful is blue ocean strategy, in fact, that a blue ocean strategic move can create brand equity that lasts for decades.

  12. Ocean FEST and TECH: Inspiring Hawaii's Students to Pursue Ocean, Earth and Environmental Science Careers

    Science.gov (United States)

    Bruno, B. C.; Wren, J. L.; Ayau, J. F.

    2013-12-01

    undergraduates from diverse backgrounds serve as teaching assistants. Pre-college and community college students can more easily relate to these young role models, which can make pursuing an ocean or earth science career seem more attainable. (7) Organizing career fairs and informal career mixers, to promote one-on-one interactions between students of all ages and diverse career professionals in a range of ocean, earth and environmental science occupations. (8) Forming relationships with minority-serving recruiting organizations and programs to ensure we reach our intended audience. Through such partnerships, we have reached students from underrepresented communities in Hawai';i and throughout the Pacific.

  13. OESbathy version 1.0: a method for reconstructing ocean bathymetry with realistic continental shelf-slope-rise structures

    OpenAIRE

    A. Goswami; P. L. Olson; L. A. Hinnov; A. Gnanadesikan

    2015-01-01

    We present a method for reconstructing global ocean bathymetry that uses a plate cooling model for the oceanic lithosphere, the age distribution of the oceanic crust, global oceanic sediment thicknesses, plus shelf-slope-rise structures calibrated at modern active and passive continental margins. Our motivation is to reconstruct realistic ocean bathymetry based on parameterized relationships of present-day variables that can be applied to global oceans in th...

  14. A reduced feedback proportional fair multiuser scheduling scheme

    KAUST Repository

    Shaqfeh, Mohammad

    2011-12-01

    Multiuser switched-diversity scheduling schemes were recently proposed in order to overcome the heavy feedback requirements of conventional opportunistic scheduling schemes by applying a threshold-based, distributed and ordered scheduling mechanism. A slight reduction in the prospected multiuser diversity gains is an acceptable trade-off for great savings in terms of required channel-state-information feedback messages. In this work, we propose a novel proportional fair multiuser switched-diversity scheduling scheme and we demonstrate that it can be optimized using a practical and distributed method to obtain the per-user feedback thresholds. We demonstrate by numerical examples that our reduced feedback proportional fair scheduler operates within 0.3 bits/sec/Hz from the achievable rates by the conventional full feedback proportional fair scheduler in Rayleigh fading conditions. © 2011 IEEE.

  15. Prospective Teachers Proportional Reasoning and Presumption of Student Work

    Directory of Open Access Journals (Sweden)

    Mujiyem Sapti

    2015-08-01

    Full Text Available This study aimed to describe the proportional reasoning of prospective teachers and their predictions about students' answers. Subjects were 4 prospective teacher  7th semester Department of Mathematics Education, Muhammadiyah University of Purworejo. Proportional reasoning task used to obtain research data. Subjects were asked to explain their reasoning and write predictions of student completion. Data was taken on October 15th, 2014. Interviews were conducted after the subjects completed the task and recorded with audio media. The research data were subject written work and interview transcripts. Data were analyzed using qualitative analysis techniques. In solving the proportional reasoning task, subjects using the cross product. However, they understand the meaning of the cross product. Subject also could predict students' reasoning on the matter.

  16. Proton-recoil proportional counter tests at TREAT

    International Nuclear Information System (INIS)

    Fink, C.L.; Eichholz, J.J.; Burrows, D.R.; DeVolpi, A.

    1979-01-01

    A methane filled proton-recoil proportional counter will be used as a fission neutron detector in the fast-neutron hodoscope. To provide meaningful fuel-motion information the proportional counter should have: a linear response over a wide range of reactor powers background ratio (the number of high energy neutrons detected must be maximized relative to low energy neutrons, and gamma ray sensitivity must be kept small); and a detector efficiency for fission neutrons above 1 MeV of approximately 1%. In addition, it is desirable that the detector and the associated amplifier/discriminator be capable of operating at counting rates in excess of 500 kHz. This paper reports on tests that were conducted on several proportional counters at the TREAT reactor

  17. Multiaxial low cycle fatigue life under non-proportional loading

    International Nuclear Information System (INIS)

    Itoh, Takamoto; Sakane, Masao; Ohsuga, Kazuki

    2013-01-01

    A simple and clear method of evaluating stress and strain ranges under non-proportional multiaxial loading where principal directions of stress and strain are changed during a cycle is needed for assessing multiaxial fatigue. This paper proposes a simple method of determining the principal stress and strain ranges and the severity of non-proportional loading with defining the rotation angles of the maximum principal stress and strain in a three dimensional stress and strain space. This study also discusses properties of multiaxial low cycle fatigue lives for various materials fatigued under non-proportional loadings and shows an applicability of a parameter proposed by author for multiaxial low cycle fatigue life evaluation

  18. Flow proportional sampling of low level liquid effluent

    International Nuclear Information System (INIS)

    Colley, D.; Jenkins, R.

    1989-01-01

    A flow proportional sampler for use on low level radioactive liquid effluent has been developed for installation on all CEGB nuclear power stations. The sampler, operates by drawing effluent continuously from the main effluent pipeline, through a sampler loop and returning it to the pipeline. The effluent in this loop is sampled by taking small, frequent aliquots using a linear acting shuttle valve. The frequency of operation of this valve is controlled by a flowmeter installed in the effluent line; sampling rate being directly proportional to effluent flowrate. (author)

  19. The proportional odds cumulative incidence model for competing risks

    DEFF Research Database (Denmark)

    Eriksson, Frank; Li, Jianing; Scheike, Thomas

    2015-01-01

    We suggest an estimator for the proportional odds cumulative incidence model for competing risks data. The key advantage of this model is that the regression parameters have the simple and useful odds ratio interpretation. The model has been considered by many authors, but it is rarely used...... in practice due to the lack of reliable estimation procedures. We suggest such procedures and show that their performance improve considerably on existing methods. We also suggest a goodness-of-fit test for the proportional odds assumption. We derive the large sample properties and provide estimators...

  20. Neutron dosimetry using proportional counters with tissue equivalent walls

    International Nuclear Information System (INIS)

    Kerviller, H. de

    1965-01-01

    The author reminds the calculation method of the neutron absorbed dose in a material and deduce of it the conditions what this material have to fill to be equivalent to biological tissues. Various proportional counters are mode with walls in new tissue equivalent material and filled with various gases. The multiplication factor and neutron energy response of these counters are investigated and compared with those obtained with ethylene lined polyethylene counters. The conditions of working of such proportional counters for neutron dosimetry in energy range 10 -2 to 15 MeV are specified. (author) [fr

  1. Gas scintillation proportional counters for x-ray synchrotron applications

    International Nuclear Information System (INIS)

    Smith, A.; Bavdaz, M.

    1992-01-01

    Gas scintillation proportional counters (GSPCs) as x-ray detectors provide some advantages and disadvantages compared with proportional counters. In this paper the various configurations of xenon filled GSPC are described including both imaging and nonimaging devices. It is intended that this work be used to configure a GSPC for a particular application and predict its general performance characteristics. The general principles of operation are described and the performance characteristics are then separately considered. A high performance, imaging, driftless GSPC is described in which a single intermediate window is used between the PMT and gas cell

  2. Avalanche localization and its effects in proportional counters

    International Nuclear Information System (INIS)

    Fischer, J.; Okuno, H.; Walenta, A.H.

    1977-11-01

    Avalanche development around the anode wire in a gas proportional counter is investigated. In the region of proportional gas amplification, the avalanche is found to be well localized on one side of the anode wire, where the electrons arrive along the field lines from the point of primary ionization. Induced signals on electrodes surrounding the anode wire are used to measure the azimuthal position of the avalanche on the anode wire. Practical applications of the phenomena such as left-right assignment in drift chambers and measurement of the angular direction of the primary ionization electrons drifting towards the anode wire are discussed

  3. Blue Ocean Thinking

    Science.gov (United States)

    Orem, Donna

    2016-01-01

    This article describes a concept called the "blue ocean thinking strategy," developed by W. Chan Kim and Renée Mauborgne, professors at INSEAD, an international graduate school of business in France. The "blue ocean" thinking strategy considers opportunities to create new markets for services, rather than focusing solely on…

  4. Indian Ocean Rim Cooperation

    DEFF Research Database (Denmark)

    Wippel, Steffen

    Since the mid-1990s, the Indian Ocean has been experiencing increasing economic cooperation among its rim states. Middle Eastern countries, too, participate in the work of the Indian Ocean Rim Association, which received new impetus in the course of the current decade. Notably Oman is a very active...

  5. Communicating Ocean Acidification

    Science.gov (United States)

    Pope, Aaron; Selna, Elizabeth

    2013-01-01

    Participation in a study circle through the National Network of Ocean and Climate Change Interpretation (NNOCCI) project enabled staff at the California Academy of Sciences to effectively engage visitors on climate change and ocean acidification topics. Strategic framing tactics were used as staff revised the scripted Coral Reef Dive program,…

  6. Global Ocean Phytoplankton

    Science.gov (United States)

    Franz, B. A.; Behrenfeld, M. J.; Siegel, D. A.; Werdell, P. J.

    2014-01-01

    Marine phytoplankton are responsible for roughly half the net primary production (NPP) on Earth, fixing atmospheric CO2 into food that fuels global ocean ecosystems and drives the ocean's biogeochemical cycles. Phytoplankton growth is highly sensitive to variations in ocean physical properties, such as upper ocean stratification and light availability within this mixed layer. Satellite ocean color sensors, such as the Sea-viewing Wide Field-of-view Sensor (SeaWiFS; McClain 2009) and Moderate Resolution Imaging Spectroradiometer (MODIS; Esaias 1998), provide observations of sufficient frequency and geographic coverage to globally monitor physically-driven changes in phytoplankton distributions. In practice, ocean color sensors retrieve the spectral distribution of visible solar radiation reflected upward from beneath the ocean surface, which can then be related to changes in the photosynthetic phytoplankton pigment, chlorophyll- a (Chla; measured in mg m-3). Here, global Chla data for 2013 are evaluated within the context of the 16-year continuous record provided through the combined observations of SeaWiFS (1997-2010) and MODIS on Aqua (MODISA; 2002-present). Ocean color measurements from the recently launched Visible and Infrared Imaging Radiometer Suite (VIIRS; 2011-present) are also considered, but results suggest that the temporal calibration of the VIIRS sensor is not yet sufficiently stable for quantitative global change studies. All MODISA (version 2013.1), SeaWiFS (version 2010.0), and VIIRS (version 2013.1) data presented here were produced by NASA using consistent Chla algorithms.

  7. Ocean acidification postcards

    Science.gov (United States)

    Schreppel, Heather A.; Cimitile, Matthew J.

    2011-01-01

    The U.S. Geological Survey (USGS) is conducting research on ocean acidification in polar, temperate, subtropical, and tropical regions including the Arctic, West Florida Shelf, and the Caribbean. Project activities include field assessment, experimental laboratory studies, and evaluation of existing data. The USGS is participating in international and interagency working groups to develop research strategies to increase understanding of the global implications of ocean acidification. Research strategies include new approaches for seawater chemistry observation and modeling, assessment of physiological effects on organisms, changes in marine ecosystem structure, new technologies, and information resources. These postcards highlight ongoing USGS research efforts in ocean acidification and carbon cycling in marine and coastal ecosystems in three different regions: polar, temperate, and tropical. To learn more about ocean acidification visit: http://coastal.er.usgs.gov/ocean-acidification/.

  8. The Utility of School-Age Narrative Microstructure Indices: INMIS and the Proportion of Restricted Utterances

    Science.gov (United States)

    Hoffman, LaVae M.

    2009-01-01

    Purpose: This research investigated the applicability of the index of narrative microstructure (INMIS; L. M. Justice et al., 2006) system for narratives that were elicited through a wordless picture book context. In addition, the viability of an alternative, simpler metric was explored. Method: Narrative transcripts using the "Frog, Where Are…

  9. Insensitivity of proportional fairness in critically loaded bandwidth sharing networks

    NARCIS (Netherlands)

    Vlasiou, M.; Zhang, J.; Zwart, B.

    2014-01-01

    Proportional fairness is a popular service allocation mechanism to describe and analyze the performance of data networks at flow level. Recently, several authors have shown that the invariant distribution of such networks admits a product form distribution under critical loading. Assuming

  10. Principles of operation of multiwire proportional and drift chambers

    International Nuclear Information System (INIS)

    Sauli, F.

    1987-01-01

    The first multiwire proportional chamber, in its modern conception, was constructed and operated in the years 1967-68. It was soon recognized that the main properties of a multiwire proportional chamber, i.e. very good time resolution, good position accuracy and self-triggered operation, are very attractive for the use of the new device in high-energy physics experiments. Today, most fast detectors contain a large number of proportional chambers, and their use has spread to many different fields of applied research, such as X-ray and heavy ion astronomy, nuclear medicine, and protein crystallography. In many respects, however, multiwire proportional chambers are still experimental devices, requiring continuous attention for good operation and sometimes reacting in unexpected ways to a change in the environmental conditions. Furthermore, in the fabrication and operation of a chamber people seem to use a mixture of competence, technical skill and magic rites, of the kind ''I do not know why I'm doing this but somebody told me to do so''. In these notes the authors illustrate the basic phenomena underlying the behaviour of a gas detector, with the hope that the reader will not only better understand the reasons for some irrational-seeming preferences (such as, for example, in the choice of the gas mixture), but will also be able better to design detectors for his specific experimental needs

  11. Proportion of patients in the Uganda rheumatic heart disease ...

    African Journals Online (AJOL)

    Proportion of patients in the Uganda rheumatic heart disease registry with advanced ... of Cardiology guidelines on the management of valvular heart disease. ... disease that require surgical treatment yet they cannot access this therapy due to ... By Country · List All Titles · Free To Read Titles This Journal is Open Access.

  12. Digital signal processing for 3He proportional counters

    International Nuclear Information System (INIS)

    Takahashi, Hiroyuki; Kawarabayashi, Jun; Kurahashi, Tomohiko; Iguchi, Tetsuo; Nakazawa, Masaharu

    1994-01-01

    Numerical analysis of individual pulses from 3 He proportional counters has been performed. A parametric approach has been used for the identification of a charge particle track direction. Using area parameters, a clear separation of events was observed for the wall effect on a triton and a proton, respectively. ((orig.))

  13. Are Explicit Apologies Proportional to the Offenses They Address?

    Science.gov (United States)

    Heritage, John; Raymond, Chase Wesley

    2016-01-01

    We consider here Goffman's proposal of proportionality between virtual offenses and remedial actions, based on the examination of 102 cases of explicit apologies. To this end, we offer a typology of the primary apology formats within the dataset, together with a broad categorization of the types of virtual offenses to which these apologies are…

  14. Radiation loading effect proportional chamber on the performances

    International Nuclear Information System (INIS)

    Alekseev, T.D.; Kalinina, N.A.; Karpukhin, V.V.; Kruglov, V.V.; Khazins, D.M.

    1980-01-01

    The effect of a space charge which appears under the effect of radiation loading on counting characteristics of a proportional chamber, is experimentally investigated. Calculations are made which take into account the effect of a space charge of positive ions formed in the chamber. The investigations have been carried out on the test board which consists of a one-coordinate proportional chamber, a telescope of two scintillation counters and a collimated 90 Sr β-source. The proportional chamber has the 160x160 mm dimensions. The signal wires with the 50 μm diameter are located with the step of s=10 mm. High-voltage planes are coiled with a wire with the 100 μm diameter and a 2 mm step. The distance between high-voltage planes are 18 mm. The chamber is blown through with a gaseous mixture, its composition is 57% Ar+38% CH 4 +5% (OCH 3 ) 2 CH 2 . When carrying out measurements in wide ranges, the density of radiation loading and the amplifier threshold are changed. The experimental results show a considerable effect of radiation loading and the value of amplifier threshold on the value of a counting characteristic. This should be taken into account when estimating the performance of a proportional chamber according to board testing using radioactive sources, as conditions for investigations are usually different from those of a physical experiment on an accelerator

  15. Contribution of working memory in the parity and proportional judgments

    NARCIS (Netherlands)

    Szymanik, J.K.; Zajenkowski, M.

    2011-01-01

    This paper presents experimental evidence on the differences in a sentence-picture verification task under additional memory load between parity and proportional quantifiers. We asked subjects to memorize strings of four or six digits, then to decide whether a quantified sentence was true for a

  16. Amplification and discrimination of signals from proportional multiwire chambers

    International Nuclear Information System (INIS)

    Papadopoulos, L.; Bosio, C.; Cordelli, M.

    1976-03-01

    A circuit is described which detects signals from proportional multiwire chambers. The threshold is about 3μ A and the time jitter of the pulse obtained is better than 2.5 ns. The circuit has one negative input and two complementary outputs. The realized module includes 8 channels with common trigger level control and was built as NIM standard unit

  17. Attentional Control and the Relatedness Proportion Effect in Semantic Priming

    Science.gov (United States)

    Hutchison, Keith A.

    2007-01-01

    In 2 experiments, participants completed both an attentional control battery (OSPAN, antisaccade, and Stroop tasks) and a modified semantic priming task. The priming task measured relatedness proportion (RP) effects within subjects, with the color of the prime indicating the probability that the to-be-named target would be related. In Experiment…

  18. Transposition of Knowledge: Encountering Proportionality in an Algebra Task

    Science.gov (United States)

    Lundberg, Anna. L. V.; Kilhamn, Cecilia

    2018-01-01

    This article reports on an analysis of the process in which "knowledge to be taught" was transposed into "knowledge actually taught," concerning a task including proportional relationships in an algebra setting in a grade 6 classroom. We identified affordances and constraints of the task by describing the mathematical…

  19. Methods of calculus for neutron spectrometry in proportional counters

    International Nuclear Information System (INIS)

    Butragueno, J.L.; Blazquez, J.B.; Barrado, J.M.

    1976-01-01

    Response functions for cylindrical proportional counters with hidrogenated gases have been determined, taking in account only wall effect, by means of two independent calculus methods. One of them is a Montecarlo application and the other one analytical at all. Results of both methods have been compared. (author) [es

  20. Methods of calculus for neutron spectrometry in proportional counters

    International Nuclear Information System (INIS)

    Butragueno Casado, J.L.; Blazquez Martinez, J.B.; Barrado Menendez, J.M.

    1976-01-01

    Response functions for cylindrical proportional counters with hydrogenated gases have been determined, taking in account only wall effect, by means of two independent calculus methods. One of them is a Monte Carlo application and the other one analytica at all. Results of both methods have been compared. (Author)

  1. Pulse-shape discrimination in IAEA tritium proportional counters

    International Nuclear Information System (INIS)

    Florkowski, T.

    1981-01-01

    Two systems of pulse-shape discrimination (PSD) for the reduction of background in low-level proportional counters were tested. A tentative conclusion is drawn that both PSD systems, although they decrease slightly the meson background, do not bring improvement in the analytical accuracy

  2. Development of proportional counters using photosensitive gases and liquids

    International Nuclear Information System (INIS)

    Anderson, D.F.

    1984-10-01

    An introduction to the history and to the principle of operation of wire chambers using photosensitive gases and liquids is presented. Their use as light sensors coupled to Gas Scintillation Proportional Counters and BaF 2 , as well as their use in Cherenkov Ring imaging, is discussed in some detail. 42 references, 21 figures

  3. Position sensitive proportional counters as focal plane detectors

    International Nuclear Information System (INIS)

    Ford, J.L.C. Jr.

    1979-01-01

    The rise time and charge division techniques for position decoding with RC-line proportional counters are reviewed. The advantages that these detectors offer as focal plane counters for nuclear spectroscopy performed with magnetic spectrographs are discussed. The theory of operation of proportional counters as position sensing devices is summarized, as well as practical aspects affecting their application. Factors limiting the position and energy resolutions obtainable with a focal plane proportional counter are evaluated and measured position and energy loss values are presented for comparison. Detector systems capable of the multiparameter measurements required for particle identification, background suppression and ray-tracing are described in order to illustrate the wide applicability of proportional counters within complex focal plane systems. Examples of the use of these counters other than with magnetic spectrographs are given in order to demonstrate their usefulness in not only nuclear physics but also in fields such as solid state physics, biology, and medicine. The influence of the new focal plane detector systems on future magnetic spectrograph designs is discussed. (Auth.)

  4. Nature and proportion of total injuries at the Stellenbosch Rugby ...

    African Journals Online (AJOL)

    Objective. The purpose of this study was to compare the nature and proportion of total injuries occurring at Stellenbosch Rugby Football Club in Stellenbosch, South Africa, between the years 1973 - 1975 and 2003 - 2005. Design. Retrospective, descriptive study. Main outcome measures. Injured rugby players from the ...

  5. Flexible geometry hodoscope using proportional chamber cathode read-out

    International Nuclear Information System (INIS)

    Aubret, C.; Bellefon, A. de; Benoit, P.; Brunet, J.M.; Tristram, G.

    1978-01-01

    The construction of a cathode read-out proportional chamber, used as a low mass hodoscope is described. Results on efficiency, time resolution and space resolution are shown. The associative logic, which permits the use of the chamber as a coplanarity chamber is briefly presented

  6. Proportionality in the New German Insurance Contract Act 2008

    NARCIS (Netherlands)

    H. Heiss (Helmut)

    2013-01-01

    markdownabstract__Abstract__ In 2008, the German legislature enacted a completely revised Insurance Contract Act, in which a new rule of proportionality replaced the former all-or-nothing principle for questions of liability. This article outlines the reasons for this shift and the impact of the

  7. A proportional counter for efficient backscatter Moessbauer effect spectroscopy

    International Nuclear Information System (INIS)

    Pawlowski, Z.; Marzec, J.; Cudny, W.; Holnicka, J.; Walentek, J.

    1979-01-01

    The authors present a novel gas-tight proportional counter with flat beryllium windows for backscatter Moessbauer spectroscopy. The krypton-filled counter has a geometry that approaches 2π and a resolution of 12% fwhm for the 14.4 keV line of 57 Fe, and is easy to manufacture. (Auth.)

  8. An Axiomatization of the Proportional Rule in Financial Networks

    NARCIS (Netherlands)

    Csoka, Péter; Herings, P. Jean-Jacques

    2017-01-01

    The most important rule to determine payments in real-life bankruptcy problems is the proportional rule. Many bankruptcy problems are characterized by network aspects and default may occur as a result of contagion. Indeed, in financial networks with defaulting agents, the values of the agents'

  9. Tsunami Speed Variations in Density-stratified Compressible Global Oceans

    Science.gov (United States)

    Watada, S.

    2013-12-01

    Recent tsunami observations in the deep ocean have accumulated unequivocal evidence that tsunami traveltime delays compared with the linear long-wave tsunami simulations occur during tsunami propagation in the deep ocean. The delay is up to 2% of the tsunami traveltime. Watada et al. [2013] investigated the cause of the delay using the normal mode theory of tsunamis and attributed the delay to the compressibility of seawater, the elasticity of the solid earth, and the gravitational potential change associated with mass motion during the passage of tsunamis. Tsunami speed variations in the deep ocean caused by seawater density stratification is investigated using a newly developed propagator matrix method that is applicable to seawater with depth-variable sound speeds and density gradients. For a 4-km deep ocean, the total tsunami speed reduction is 0.45% compared with incompressible homogeneous seawater; two thirds of the reduction is due to elastic energy stored in the water and one third is due to water density stratification mainly by hydrostatic compression. Tsunami speeds are computed for global ocean density and sound speed profiles and characteristic structures are discussed. Tsunami speed reductions are proportional to ocean depth with small variations, except for in warm Mediterranean seas. The impacts of seawater compressibility and the elasticity effect of the solid earth on tsunami traveltime should be included for precise modeling of trans-oceanic tsunamis. Data locations where a vertical ocean profile deeper than 2500 m is available in World Ocean Atlas 2009. The dark gray area indicates the Pacific Ocean defined in WOA09. a) Tsunami speed variations. Red, gray and black bars represent global, Pacific, and Mediterranean Sea, respectively. b) Regression lines of the tsunami velocity reduction for all oceans. c)Vertical ocean profiles at grid points indicated by the stars in Figure 1.

  10. Global Ocean Sedimentation Patterns: Plate Tectonic History Versus Climate Change

    Science.gov (United States)

    Goswami, A.; Reynolds, E.; Olson, P.; Hinnov, L. A.; Gnanadesikan, A.

    2014-12-01

    Global sediment data (Whittaker et al., 2013) and carbonate content data (Archer, 1996) allows examination of ocean sedimentation evolution with respect to age of the underlying ocean crust (Müller et al., 2008). From these data, we construct time series of ocean sediment thickness and carbonate deposition rate for the Atlantic, Pacific, and Indian ocean basins for the past 120 Ma. These time series are unique to each basin and reflect an integrated response to plate tectonics and climate change. The goal is to parameterize ocean sedimentation tied to crustal age for paleoclimate studies. For each basin, total sediment thickness and carbonate deposition rate from 0.1 x 0.1 degree cells are binned according to basement crustal age; area-corrected moments (mean, variance, etc.) are calculated for each bin. Segmented linear fits identify trends in present-day carbonate deposition rates and changes in ocean sedimentation from 0 to 120 Ma. In the North and South Atlantic and Indian oceans, mean sediment thickness versus crustal age is well represented by three linear segments, with the slope of each segment increasing with increasing crustal age. However, the transition age between linear segments varies among the three basins. In contrast, mean sediment thickness in the North and South Pacific oceans are numerically smaller and well represented by two linear segments with slopes that decrease with increasing crustal age. These opposing trends are more consistent with the plate tectonic history of each basin being the controlling factor in sedimentation rates, rather than climate change. Unlike total sediment thickness, carbonate deposition rates decrease smoothly with crustal age in all basins, with the primary controls being ocean chemistry and water column depth.References: Archer, D., 1996, Global Biogeochem. Cycles 10, 159-174.Müller, R.D., et al., 2008, Science, 319, 1357-1362.Whittaker, J., et al., 2013, Geochem., Geophys., Geosyst. DOI: 10.1002/ggge.20181

  11. Visualizing Proportions and Dissimilarities by Space-filling Maps

    DEFF Research Database (Denmark)

    Carrizosa, Emilio; Guerrero, Vanesa; Morales, Dolores Romero

    2017-01-01

    In this paper we address the problem of visualizing a set of individuals, which have attached a statistical value given as a proportion, and a dissimilarity measure. Each individual is represented as a region within the unit square, in such a way that the area of the regions represent...... the proportions and the distances between them represent the dissimilarities. To enhance the interpretability of the representation, the regions are required to satisfy two properties. First, they must form a partition of the unit square, namely, the portions in which it is divided must cover its area without...... is solved heuristically by using the Large Neighborhood Search technique. The methodology proposed in this paper is applied to three real-world datasets: the first one concerning financial markets in Europe and Asia, the second one about the letters in the English alphabet, and finally the provinces...

  12. Combining proportional and majoritarian democracy: An institutional design proposal

    Directory of Open Access Journals (Sweden)

    Steffen Ganghof

    2016-08-01

    Full Text Available The article proposes a new way to combine the “proportional” and “majoritarian” visions of democracy. The proposal blends elements of mixed electoral systems, parliamentarism, presidentialism and bicameralism. Voters are given a single vote to make two simultaneous choices: one about the proportional composition of the legislature and one about the two top parties forming a majoritarian “confidence chamber” embedded within the legislature. Only the majority in this chamber has the power to dismiss the cabinet in a vote of no-confidence. The proposed system virtually guarantees the feasibility of identifiable and stable one-party cabinets governing with shifting, issue-specific majorities in a highly proportional legislature. It is illustrated with respect to the 2013 federal election in Germany.

  13. Measurements of electron attachment by oxygen molecule in proportional counter

    Energy Technology Data Exchange (ETDEWEB)

    Tosaki, M., E-mail: tosaki.mitsuo.3v@kyoto-u.ac.jp [Radioisotope Research Center, Kyoto University, Kyoto 606-8501 (Japan); Kawano, T. [National Institute for Fusion Science, 322-6 Oroshi, Toki 509-5292 (Japan); Isozumi, Y. [Radioisotope Research Center, Kyoto University, Kyoto 606-8501 (Japan)

    2013-11-15

    We present pulse height measurements for 5-keV Auger electrons from a radioactive {sup 55}Fe source mounted at the inner cathode surface of cylindrical proportional counter, which is operated with CH{sub 4} admixed dry air or N{sub 2}. A clear shift of the pulse height has been observed by varying the amount of the admixtures; the number of electrons, created in the primary ionization by Auger electrons, is decreased by the electron attachment of the admixtures during their drift from the place near the source to the anode wire. The large gas amplification (typically 10{sup 4}) in the secondary ionization of proportional counter makes it possible to investigate a small change in the number of primary electrons. The electron attenuation cross-section of O{sub 2} has been evaluated by analyzing the shifts of the pulse height caused by the electron attachment to dry air and N{sub 2}.

  14. Sample Size Calculation for Controlling False Discovery Proportion

    Directory of Open Access Journals (Sweden)

    Shulian Shang

    2012-01-01

    Full Text Available The false discovery proportion (FDP, the proportion of incorrect rejections among all rejections, is a direct measure of abundance of false positive findings in multiple testing. Many methods have been proposed to control FDP, but they are too conservative to be useful for power analysis. Study designs for controlling the mean of FDP, which is false discovery rate, have been commonly used. However, there has been little attempt to design study with direct FDP control to achieve certain level of efficiency. We provide a sample size calculation method using the variance formula of the FDP under weak-dependence assumptions to achieve the desired overall power. The relationship between design parameters and sample size is explored. The adequacy of the procedure is assessed by simulation. We illustrate the method using estimated correlations from a prostate cancer dataset.

  15. Nonlinear kinematic hardening under non-proportional loading

    International Nuclear Information System (INIS)

    Ottosen, N.S.

    1979-07-01

    Within the framework of conventional plasticity theory, it is first determined under which conditions Melan-Prager's and Ziegler's kinematic hardening rules result in identical material behaviour. Next, assuming initial isotropy and adopting the von Mises yield criterion, a nonlinear kinematic hardening function is proposed for prediction of metal behaviour. The model assumes that hardening at a specific stress point depends on the direction of the new incremental loading. Hereby a realistic response is obtained for general reversed loading, and a smooth behaviour is assured, even when loading deviates more and more from proportional loading and ultimately results in reversed loading. The predictions of the proposed model for non-proportional loading under plane stress conditions are compared with those of the classical linear kinematic model, the isotropic model and with published experimental data. Finally, the limitations of the proposaed model are discussed. (author)

  16. DEVELOPMENT OF HETEROGENEOUS PROPORTIONAL COUNTERS FOR NEUTRON DOSIMETRY.

    Science.gov (United States)

    Forouzan, Faezeh; Waker, Anthony J

    2018-01-10

    The use of a custom-made cylindrical graphite proportional counter (Cy-GPC) along with a cylindrical tissue equivalent proportional counter (TEPC) for neutron-gamma mixed-field dosimetry has been studied in the following steps: first, the consistency of the gamma dose measurement between the Cy-TEPC and the Cy-GPC was investigated over a range of 20 keV (X-ray) to 0.661 MeV (Cs-137 gamma ray). Then, with both the counters used simultaneously, the neutron and gamma ray doses produced by a P385 Neutron Generator (Thermo Fisher Scientific) together with a Cs-137 gamma source were determined. © The Author(s) 2018. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  17. New proportional counter assembly in Gliwice 14C laboratory

    International Nuclear Information System (INIS)

    Moscicki, W.; Zastawny, A.

    1977-01-01

    The design and parameters are described of a proportional counter for low level counting. The cathode tube 80 mm in diameter and 30 cm in length is made of pure copper. The anode is a tungsten wire 0.05 mm in diameter. The cathode tube is surrounded by a cylindrical ring container with mercury. The total volume of the counter is 1.5 l and it is filled with carbon dioxide. At a pressure of 1 at of CO 2 the counter background is 4.20+-0.05 cpm and contemporary 14 C net effect 10.22+-0.10 cpm; at a pressure of 2 at of CO 2 the background is 4.40+-0.05 cpm and the contemporary 14 C net effect 20.53+-10 cpm. The efficiency of the proportional counter is 88% in both cases. (J.B.)

  18. Photometric study of divine proportion and its correlation with facial attractiveness

    Directory of Open Access Journals (Sweden)

    Ana Paula Lazzari Marques Peron

    2012-04-01

    Full Text Available OBJECTIVE: The aim of this study was to evaluate if there is correlation between perception of facial esthetic and divine proportion, verifying if most attractive faces are closer to and less attractive faces are more distant to this proportion. METHODS: Standard facial photographs (frontal and lateral in natural head position were taken of a sample of 85 Brazilian Caucasian women, with mean age of 23 years and 9 months. The photographs were evaluated by 5 orthodontists, 5 artists and 5 laymen and were classified, according to their subjective analysis of facial esthetic, in pleasant, acceptable and not pleasant. Frontal photographs were evaluated by divine proportion analysis using the computerized method. RESULTS AND CONCLUSIONS: According to subjective analysis the sample consisted 18.8% of pleasant, 70.6% of acceptable and 10.6% of not pleasant faces. After statistical analysis, a lack of agreement was verified in esthetic facial preferences among the three groups of observers. It was also possible to verify that in this research there was no correlation between perception of facial beauty and divine proportion.

  19. Maxillary anterior tooth dimensions and proportions in an Irish young adult population.

    LENUS (Irish Health Repository)

    Condon, M

    2011-07-01

    This study was undertaken in a young Irish population to determine the dimensions and ratios of the six maxillary anterior teeth. One hundred and nine Irish subjects (age 18-25 inclusive) had irreversible hydrocolloid impressions made of their maxillary dentition poured in type V stone. Clinical crown dimensions were measured with a digital calliper. The stone casts were digitally photographed in a standardised manner enabling calculation of various ratios between the maxillary anterior teeth. Sexual dimorphism existed for various tooth dimensions; most notably canine teeth were in the region of 0·8 mm longer and 0·6 mm wider in males. Central and lateral incisors were found to be 0·5 mm wider in males. It is, therefore, recommended that dimensional tooth guidelines should be given for each of the sexes and not on a population basis. With regard to tooth proportion ratios, no significant differences were found between genders or the left and right sides for any of the measurements or ratios measured. The digitally recorded tooth proportions were similar for both sexes, and the Golden Proportion guidelines could only be applied to the lateral incisor\\/central incisor widths (0·618). Identified width proportions for the canine\\/central incisor were 0·58 and for canine\\/lateral incisor 0·89.

  20. Cretaceous oceanic anoxic events: causes and consequences

    NARCIS (Netherlands)

    Schlanger, S.O.; Jenkyns, H.C.

    2007-01-01

    Organic carbon-rich sediments are globally developed in pelagic sedimentary sequences of Aptian-Albian and Cenomanian-Turonian age. They formed in a variety of paleo-bathymetric settings including oceanic plateaus and basins, continental margins and shelf seas. The widespread nature of these

  1. Multiwire proportional counter (lecture by an electromagnetic delay line)

    International Nuclear Information System (INIS)

    Bruere-Dawson, R.

    1989-01-01

    For track localisation of ionizing particles with multiwire proportional chamber, an electronic chain including amplifying, shaping and memorizing circuits is required for each wire. In order to lower the cost of this type of detector, an electromagnetic delay line is proposed among various possibilities. In this paper, different coupling modes between chamber and delay line are studied with their respective advantages. The realization of one meter long delay line with a unit delay time of 15 ns per cm is also presented [fr

  2. Quench gases for xenon- (and krypton-)filled proportional counters

    International Nuclear Information System (INIS)

    Ramsey, B.D.; Agrawal, P.C.

    1988-01-01

    Xenon-filled proportional counters are used extensively in astronomy, particularly in the hard X-ray region. The choice of quench gas can have a significant effect on the operating characteristics of the instrument although the data necessary to make the choice are not easily obtainable. We present results which detail the performance obtained from both cylindrical and parallel field geometries for a wide variety of readily available, ultrahigh or research grade purity, quench gases. (orig.)

  3. Azimuthal spread of the avalanche in proportional chambers

    International Nuclear Information System (INIS)

    Okuno, H.; Fischer, J.; Radeka, V.; Walenta, A.H.

    1978-10-01

    The angular distribution of the avalanche around the anode wire in the gas proportional counter is determined by measuring the distribution of positive ions arriving on cathode strips surrounding the anode wire for each single event. The shape and width of the distribution depend on such factors as the gas gain, the anode diameter, the counting gas and the primary ionization density. Effects of these factors are studied systematically, and their importance for practical counter applications is discussed

  4. Metrology and Proportion in the Ecclesiastical Architecture of Medieval Ireland

    OpenAIRE

    Behan, Avril; Moss, Rachel

    2008-01-01

    The aim of this paper is to examine the extent to which detailed empirical analysis of the metrology and proportional systems used in the design of Irish ecclesiastical architecture can be analysed to provide historical information not otherwise available. Focussing on a relatively limited sample of window tracery designs as a case study, it will first set out to establish what, if any, systems were in use, and then what light these might shed on the background, training and work practices of...

  5. Data-driven smooth tests of the proportional hazards assumption

    Czech Academy of Sciences Publication Activity Database

    Kraus, David

    2007-01-01

    Roč. 13, č. 1 (2007), s. 1-16 ISSN 1380-7870 R&D Projects: GA AV ČR(CZ) IAA101120604; GA ČR(CZ) GD201/05/H007 Institutional research plan: CEZ:AV0Z10750506 Keywords : Cox model * Neyman's smooth test * proportional hazards assumption * Schwarz's selection rule Subject RIV: BA - General Mathematics Impact factor: 0.491, year: 2007

  6. Populational Growth Models Proportional to Beta Densities with Allee Effect

    Science.gov (United States)

    Aleixo, Sandra M.; Rocha, J. Leonel; Pestana, Dinis D.

    2009-05-01

    We consider populations growth models with Allee effect, proportional to beta densities with shape parameters p and 2, where the dynamical complexity is related with the Malthusian parameter r. For p>2, these models exhibit a population dynamics with natural Allee effect. However, in the case of 1

  7. Fast multiwire proportional chamber data encoding system for proton tomography

    International Nuclear Information System (INIS)

    Brown, D.

    1979-01-01

    A data encoding system that rapidly generates the binary address of an active wire in a 512-wire multiwire proportional chamber has been developed. It can accept a second event on a different wire after a deadtime of 130 ns. The system incorporates preprocessing of the wire data to reject events that would require more than one wire address. It also includes a first-in, first-out memory to buffer the data flow

  8. Relating the Electrical Resistance of Fresh Concrete to Mixture Proportions.

    Science.gov (United States)

    Obla, K; Hong, R; Sherman, S; Bentz, D P; Jones, S Z

    2018-01-01

    Characterization of fresh concrete is critical for assuring the quality of our nation's constructed infrastructure. While fresh concrete arriving at a job site in a ready-mixed concrete truck is typically characterized by measuring temperature, slump, unit weight, and air content, here the measurement of the electrical resistance of a freshly cast cylinder of concrete is investigated as a means of assessing mixture proportions, specifically cement and water contents. Both cement and water contents influence the measured electrical resistance of a sample of fresh concrete: the cement by producing ions (chiefly K + , Na + , and OH - ) that are the main source of electrical conduction; and the water by providing the main conductive pathways through which the current travels. Relating the measured electrical resistance to attributes of the mixture proportions, such as water-cement ratio by mass ( w/c ), is explored for a set of eleven different concrete mixtures prepared in the laboratory. In these mixtures, w/c , paste content, air content, fly ash content, high range water reducer dosage, and cement alkali content are all varied. Additionally, concrete electrical resistance data is supplemented by measuring the resistivity of its component pore solution obtained from 5 laboratory-prepared cement pastes with the same proportions as their corresponding concrete mixtures. Only measuring the concrete electrical resistance can provide a prediction of the mixture's paste content or the product w*c ; conversely, when pore solution resistivity is also available, w/c and water content of the concrete mixture can be reasonably assessed.

  9. Is proportion burned severely related to daily area burned?

    International Nuclear Information System (INIS)

    Birch, Donovan S; Morgan, Penelope; Smith, Alistair M S; Kolden, Crystal A; Hudak, Andrew T

    2014-01-01

    The ecological effects of forest fires burning with high severity are long-lived and have the greatest impact on vegetation successional trajectories, as compared to low-to-moderate severity fires. The primary drivers of high severity fire are unclear, but it has been hypothesized that wind-driven, large fire-growth days play a significant role, particularly on large fires in forested ecosystems. Here, we examined the relative proportion of classified burn severity for individual daily areas burned that occurred during 42 large forest fires in central Idaho and western Montana from 2005 to 2007 and 2011. Using infrared perimeter data for wildfires with five or more consecutive days of mapped perimeters, we delineated 2697 individual daily areas burned from which we calculated the proportions of each of three burn severity classes (high, moderate, and low) using the differenced normalized burn ratio as mapped for large fires by the Monitoring Trends in Burn Severity project. We found that the proportion of high burn severity was weakly correlated (Kendall τ = 0.299) with size of daily area burned (DAB). Burn severity was highly variable, even for the largest (95th percentile) in DAB, suggesting that other variables than fire extent influence the ecological effects of fires. We suggest that these results do not support the prioritization of large runs during fire rehabilitation efforts, since the underlying assumption in this prioritization is a positive relationship between severity and area burned in a day. (letters)

  10. Contributions to the methodology of multiwire proportional chambers

    International Nuclear Information System (INIS)

    Petrascu, H.

    1993-01-01

    The Ph.D. thesis presents first the realization, testing, optimization, and use of detection equipment based on position sensitive multiwire proportional chambers (MWPC), high resolution proportional counters, and of ΔE,E ionization chambers. In the second chapter it is presented the realization MWPC, in which the coordinate information is obtained by means of LC-delay lines, containing many original constructive elements. By using a system of three MWPC in coincidence, an experimental testing of the theoretically predicted pion generation in the 235 U fission process, was performed. An upper limit of 10 -11 for this process was found. In the 3-rd chapter there are presented the developments of high resolution proportional counters for X-ray spectrometry. Various penning mixtures of high purity gases were studied. The purity of gases was assured by a technology described in a Romanian patents. These counters are currently use in various applications as a rapid analysis of steel marks and in the mining industry. the 4-th chapter is dedicated to the construction and using of ΔE,E closed, high resolution ionization chambers. With these chambers the multinucleon transfer in the 27 Al( 14 M, X) reaction at 116 MeV bombarding energy was investigated. Also this type of chambers was used for the elaboration of an absolute method for analysis and profiling of impurities in silicon wafers. This method is described in the last part of the chapter. (Author) 117 Figs., 8 Tabs., 55 Refs

  11. An extended parametrization of gas amplification in proportional wire chambers

    International Nuclear Information System (INIS)

    Beingessner, S.P.; Carnegie, R.K.; Hargrove, C.K.

    1987-01-01

    It is normally assumed that the gas amplification in proportional chambers is a function of Townsend's first ionization coefficient, α, and that α is a function of the anode surface electric field only. Experimental measurements are presented demonstrating the breakdown of the latter assumption for electric fields, X, greater than about 150 V/cm/Torr on the anode wire surface for a gas mixture of 80/20 argon/methane. For larger values of X, the parametrization of the proportional gas gain data requires an additional term related to the gradient of the electric field near the wire. This extended gain parametrization remains valid until the onset of nonproportional contributions such as positive ion space charge saturation effects. Furthermore, deviations of the data from this parametrization are used to measure the onset of these space charge effects. A simple scaling dependence of the gain data on the product of pressure and wire radius over the whole proportional range is also demonstrated. (orig.)

  12. Duality between resource reservation and proportional share resource allocation

    Science.gov (United States)

    Stoica, Ion; Abdel-Wahab, Hussein; Jeffay, Kevin

    1997-01-01

    We describe anew framework for resource allocation that unifies the well-known proportional share and resource reservation policies. Each client is characterized by two parameters: a weight that represents the rate at which the client 'pays' for the resource, and a share that represents the fraction of the resource that the client should receive. A fixed rate corresponds to a proportional share allocation, while a fixed share corresponds to a reservation. Furthermore, rates and shares are duals of each other. Once one parameters is fixed the other becomes fixed as well. If a client asks for a fixed share then the level of competition for the resource determines the rate at which it has to pay, while if the rate is fixed, level of competition determines the service time the clients should receive. To implement this framework we use a new proportional share algorithm, called earliest eligible virtual deadline first, that achieves optical accuracy in the rates at which process execute. This makes it possible to provide support for highly predictable, real-time services. As a proof of concept we have implemented a prototype of a CPU scheduler under the FreeBSD operating system. The experimental results show that our scheduler achieves the goal of providing integrated support for batch and real-time applications.

  13. Oceans and Coasts

    Science.gov (United States)

    An overview of EPA’s oceans, coasts, estuaries and beaches programs and the regulatory (permits/rules) and non-regulatory approaches for managing their associated environmental issues, such as water pollution and climate change.

  14. Ocean Dumping: International Treaties

    Science.gov (United States)

    The London Convention and London Protocol are global treaties to protect the marine environment from pollution caused by the ocean dumping of wastes. The Marine, Protection, Research and Sanctuaries Act implements the requirements of the LC.

  15. Ocean Technology Development Tank

    Data.gov (United States)

    Federal Laboratory Consortium — The new SWFSC laboratory in La Jolla incorporates a large sea- and fresh-water Ocean Technology Development Tank. This world-class facility expands NOAA's ability to...

  16. Loggerhead oceanic stage duration

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This study involves analysis of skeletal growth marks in humerus bones of 222 juvenile loggerhead sea turtles (Caretta caretta) stranded dead along the Atlantic US...

  17. Ocean iron fertilization

    Digital Repository Service at National Institute of Oceanography (India)

    Naqvi, S.W.A.; Smetacek, V.

    In 2009 and 2010, an Indo-German scientific expedition dusted the ocean with iron to stimulate the biological pump that captures atmosphereic carbon dioxide. Two onboard scientists tell the story of this controversial project. Besides raising...

  18. Ocean Dumping Control Regulations

    International Nuclear Information System (INIS)

    1978-01-01

    These Regulations were made further to the Ocean Dumping Control Act which provides for restrictions in dumping operations. The Regulations contain model applications for permits to dump or load a series of materials. (NEA)

  19. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.; Delworth, Thomas L.; Ramaswamy, V.; Stouffer, Ronald J.; Wittenberg, Andrew; Zeng, Fanrong

    2009-01-01

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean

  20. IODE OceanTeacher

    OpenAIRE

    Brown, M.; Pikula, L.; Reed, G.

    2002-01-01

    The OceanTeacher website and CD-ROM publication have proven to be powerful and flexible tools for marine data and information management training. There are two segments of OceanTeacher: marine data management and marine information management. The IODE trainers have created an encyclopedic Resource Kit covering all aspects of the subjects. Through continual updates, the Kit provides the latest versions of popular public-domain software, documentation for global and regional datasets, docu...

  1. Modeling of oceanic vortices

    Science.gov (United States)

    Cushman-Roisin, B.

    Following on a tradition of biannual meetings, the 5th Colloquium on the Modeling of Oceanic Vortices was held May 21-23, 1990, at the Thayer School of Engineering at Dartmouth College, Hanover, N.H. The colloquium series, sponsored by the Office of Naval Research, is intended to gather oceanographers who contribute to our understanding of oceanic mesoscale vortices via analytical, numerical and experimental modeling techniques.

  2. Wind Generated Ocean Waves

    DEFF Research Database (Denmark)

    Frigaard, Peter

    2001-01-01

    Book review: I. R. Young, Elsevier Ocean Engineering Series, Vol 2. Elsevier Science, Oxford, UK, 1999, 306 pages, hardbound, ISBN 0-08-043317-0, Dfl. 275,00 (US$ 139.50)......Book review: I. R. Young, Elsevier Ocean Engineering Series, Vol 2. Elsevier Science, Oxford, UK, 1999, 306 pages, hardbound, ISBN 0-08-043317-0, Dfl. 275,00 (US$ 139.50)...

  3. LDPC Codes with Minimum Distance Proportional to Block Size

    Science.gov (United States)

    Divsalar, Dariush; Jones, Christopher; Dolinar, Samuel; Thorpe, Jeremy

    2009-01-01

    Low-density parity-check (LDPC) codes characterized by minimum Hamming distances proportional to block sizes have been demonstrated. Like the codes mentioned in the immediately preceding article, the present codes are error-correcting codes suitable for use in a variety of wireless data-communication systems that include noisy channels. The previously mentioned codes have low decoding thresholds and reasonably low error floors. However, the minimum Hamming distances of those codes do not grow linearly with code-block sizes. Codes that have this minimum-distance property exhibit very low error floors. Examples of such codes include regular LDPC codes with variable degrees of at least 3. Unfortunately, the decoding thresholds of regular LDPC codes are high. Hence, there is a need for LDPC codes characterized by both low decoding thresholds and, in order to obtain acceptably low error floors, minimum Hamming distances that are proportional to code-block sizes. The present codes were developed to satisfy this need. The minimum Hamming distances of the present codes have been shown, through consideration of ensemble-average weight enumerators, to be proportional to code block sizes. As in the cases of irregular ensembles, the properties of these codes are sensitive to the proportion of degree-2 variable nodes. A code having too few such nodes tends to have an iterative decoding threshold that is far from the capacity threshold. A code having too many such nodes tends not to exhibit a minimum distance that is proportional to block size. Results of computational simulations have shown that the decoding thresholds of codes of the present type are lower than those of regular LDPC codes. Included in the simulations were a few examples from a family of codes characterized by rates ranging from low to high and by thresholds that adhere closely to their respective channel capacity thresholds; the simulation results from these examples showed that the codes in question have low

  4. Longevity of Atlantic Sharpnose Sharks Rhizoprionodon terraenovae and Blacknose Sharks Carcharhinus acronotus in the western North Atlantic Ocean based on tag-recapture data and direct age estimates [v2; ref status: indexed, http://f1000r.es/4fj

    Directory of Open Access Journals (Sweden)

    Bryan S. Frazier

    2015-01-01

    Full Text Available Longevity of Rhizoprionodon terraenovae and Carcharhinus acronotus in the western North Atlantic Ocean was examined using direct age estimates from vertebral sections and tag-recapture data. Time-at-liberty ranged from 7.7-14.0 years (mean =10.1 for R. terraenovae and 10.9-12.8 years (mean =11.9 for C. acronotus. Maximum estimated longevity was determined to be 19.8 years through tag-recapture data and 18.5 years from direct age estimates for R. terraenovae and 22.8 years through tag-recapture data and 20.5 years through direct age estimates for C. acronotus. These longevity estimates represent a large increase over previous estimates and may have significant effects on analyses that depend on longevity including lifetime fecundity, mortality rates, demographic analyses and stock assessments.

  5. The Ocean: Our Future

    Science.gov (United States)

    Independent World Commission On The Oceans; Soares, Mario

    1998-09-01

    The Ocean, Our Future is the official report of the Independent World Commission on the Oceans, chaired by Mário Soares, former President of Portugal. Its aim is to summarize the very real problems affecting the ocean and its future management, and to provide imaginative solutions to these various and interlocking problems. The oceans have traditionally been taken for granted as a source of wealth, opportunity and abundance. Our growing understanding of the oceans has fundamentally changed this perception. We now know that in some areas, abundance is giving way to real scarcity, resulting in severe conflicts. Territorial disputes that threaten peace and security, disruptions to global climate, overfishing, habitat destruction, species extinction, indiscriminate trawling, pollution, the dumping of hazardous and toxic wastes, piracy, terrorism, illegal trafficking and the destruction of coastal communities are among the problems that today form an integral part of the unfolding drama of the oceans. Based on the deliberations, experience and input of more than 100 specialists from around the world, this timely volume provides a powerful overview of the state of our water world.

  6. Volcanic signals in oceans

    KAUST Repository

    Stenchikov, Georgiy L.

    2009-08-22

    Sulfate aerosols resulting from strong volcanic explosions last for 2–3 years in the lower stratosphere. Therefore it was traditionally believed that volcanic impacts produce mainly short-term, transient climate perturbations. However, the ocean integrates volcanic radiative cooling and responds over a wide range of time scales. The associated processes, especially ocean heat uptake, play a key role in ongoing climate change. However, they are not well constrained by observations, and attempts to simulate them in current climate models used for climate predictions yield a range of uncertainty. Volcanic impacts on the ocean provide an independent means of assessing these processes. This study focuses on quantification of the seasonal to multidecadal time scale response of the ocean to explosive volcanism. It employs the coupled climate model CM2.1, developed recently at the National Oceanic and Atmospheric Administration\\'s Geophysical Fluid Dynamics Laboratory, to simulate the response to the 1991 Pinatubo and the 1815 Tambora eruptions, which were the largest in the 20th and 19th centuries, respectively. The simulated climate perturbations compare well with available observations for the Pinatubo period. The stronger Tambora forcing produces responses with higher signal-to-noise ratio. Volcanic cooling tends to strengthen the Atlantic meridional overturning circulation. Sea ice extent appears to be sensitive to volcanic forcing, especially during the warm season. Because of the extremely long relaxation time of ocean subsurface temperature and sea level, the perturbations caused by the Tambora eruption could have lasted well into the 20th century.

  7. Impacts of Ocean Acidification

    Energy Technology Data Exchange (ETDEWEB)

    Bijma, Jelle (Alfred Wegener Inst., D-27570 Bremerhaven (Germany)) (and others)

    2009-08-15

    There is growing scientific evidence that, as a result of increasing anthropogenic carbon dioxide (CO{sub 2}) emissions, absorption of CO{sub 2} by the oceans has already noticeably increased the average oceanic acidity from pre-industrial levels. This global threat requires a global response. According to the Intergovernmental Panel on Climate Change (IPCC), continuing CO{sub 2} emissions in line with current trends could make the oceans up to 150% more acidic by 2100 than they were at the beginning of the Anthropocene. Acidification decreases the ability of the ocean to absorb additional atmospheric CO{sub 2}, which implies that future CO{sub 2} emissions are likely to lead to more rapid global warming. Ocean acidification is also problematic because of its negative effects on marine ecosystems, especially marine calcifying organisms, and marine resources and services upon which human societies largely depend such as energy, water, and fisheries. For example, it is predicted that by 2100 around 70% of all cold-water corals, especially those in the higher latitudes, will live in waters undersaturated in carbonate due to ocean acidification. Recent research indicates that ocean acidification might also result in increasing levels of jellyfish in some marine ecosystems. Aside from direct effects, ocean acidification together with other global change-induced impacts such as marine and coastal pollution and the introduction of invasive alien species are likely to result in more fragile marine ecosystems, making them more vulnerable to other environmental impacts resulting from, for example, coastal deforestation and widescale fisheries. The Marine Board-ESF Position Paper on the Impacts of Climate Change on the European Marine and Coastal Environment - Ecosystems indicated that presenting ocean acidification issues to policy makers is a key issue and challenge. Indeed, as the consequences of ocean acidification are expected to emerge rapidly and drastically, but are

  8. Decrease in oceanic crustal thickness since the breakup of Pangaea

    Science.gov (United States)

    van Avendonk, Harm J. A.; Davis, Joshua K.; Harding, Jennifer L.; Lawver, Lawrence A.

    2017-01-01

    Earth's mantle has cooled by 6-11 °C every 100 million years since the Archaean, 2.5 billion years ago. In more recent times, the surface heat loss that led to this temperature drop may have been enhanced by plate-tectonic processes, such as continental breakup, the continuous creation of oceanic lithosphere at mid-ocean ridges and subduction at deep-sea trenches. Here we use a compilation of marine seismic refraction data from ocean basins globally to analyse changes in the thickness of oceanic crust over time. We find that oceanic crust formed in the mid-Jurassic, about 170 million years ago, is 1.7 km thicker on average than crust produced along the present-day mid-ocean ridge system. If a higher mantle temperature is the cause of thicker Jurassic ocean crust, the upper mantle may have cooled by 15-20 °C per 100 million years over this time period. The difference between this and the long-term mantle cooling rate indeed suggests that modern plate tectonics coincide with greater mantle heat loss. We also find that the increase of ocean crustal thickness with plate age is stronger in the Indian and Atlantic oceans compared with the Pacific Ocean. This observation supports the idea that upper mantle temperature in the Jurassic was higher in the wake of the fragmented supercontinent Pangaea due to the effect of continental insulation.

  9. Causes of strong ocean heating during glacial periods

    Science.gov (United States)

    Zimov, N.; Zimov, S. A.

    2013-12-01

    During the last deglaciation period, the strongest climate changes occurred across the North Atlantic regions. Analyses of borehole temperatures from the Greenland ice sheet have yielded air temperature change estimates of 25°C over the deglaciation period (Dahl-Jensen et al. 1998). Such huge temperature changes cannot currently be explained in the frames of modern knowledge about climate. We propose that glacial-interglacial cycles are connected with gradual warming of ocean interior waters over the course of glaciations and quick transport of accumulated heat from ocean to the atmosphere during the deglaciation periods. Modern day ocean circulation is dominated by thermal convection with cold waters subsiding in the Northern Atlantic and filling up the ocean interior with cold and heavy water. However during the glaciation thermal circulation stopped and ocean circulation was driven by 'haline pumps' -Red and Mediterranean seas connected with ocean with only narrow but deep straights acts as evaporative basins, separating ocean water into fresh water which returns to the ocean surface (precipitation) and warm but salty, and therefore heavy, water which flows down to the ocean floor. This haline pump is stratifying the ocean, allowing warmer water locate under the colder water and thus stopping thermal convection in the ocean. Additional ocean interior warming is driven by geothermal heat flux and decomposition of organic rain. To test the hypothesis we present simple ocean box model that describes thermohaline circulation in the World Ocean. The first box is the Red and Mediterranean sea, the second is united high-latitude seas, the third is the ocean surface, and the fourth the ocean interior. The volume of these water masses and straight cross-sections are taken to be close to real values. We have accepted that the exchange of water between boxes is proportional to the difference in water density in these boxes, Sun energy inputs to the ocean and sea surface

  10. Limitations of Cox Proportional Hazards Analysis in Mortality Prediction of Patients with Acute Coronary Syndrome

    Directory of Open Access Journals (Sweden)

    Babińska Magdalena

    2015-12-01

    Full Text Available The aim of this study was to evaluate the possibility of incorrect assessment of mortality risk factors in a group of patients affected by acute coronary syndrome, due to the lack of hazard proportionality in the Cox regression model. One hundred and fifty consecutive patients with acute coronary syndrome (ACS and no age limit were enrolled. Univariable and multivariable Cox proportional hazard analyses were performed. The proportional hazard assumptions were verified using Schoenfeld residuals, χ2 test and rank correlation coefficient t between residuals and time. In the total group of 150 patients, 33 (22.0% deaths from any cause were registered in the follow-up time period of 64 months. The non-survivors were significantly older and had increased prevalence of diabetes and erythrocyturia, longer history of coronary artery disease, higher concentrations of serum creatinine, cystatin C, uric acid, glucose, C-reactive protein (CRP, homocysteine and B-type natriuretic peptide (NT-proBNP, and lower concentrations of serum sodium. No significant differences in echocardiography parameters were observed between groups. The following factors were risk of death factors and fulfilled the proportional hazard assumption in the univariable model: smoking, occurrence of diabetes and anaemia, duration of coronary artery disease, and abnormal serum concentrations of uric acid, sodium, homocysteine, cystatin C and NT-proBNP, while in the multivariable model, the risk of death factors were: smoking and elevated concentrations of homocysteine and NT-proBNP. The study has demonstrated that violation of the proportional hazard assumption in the Cox regression model may lead to creating a false model that does not include only time-independent predictive factors.

  11. PRINCIPLE OF PROPORTIONALITY, CRITERION OF LEGITIMACY IN THE PUBLIC LAW

    Directory of Open Access Journals (Sweden)

    MARIUS ANDREESCU

    2011-04-01

    Full Text Available A problem of essence of the state is the one to delimit the discretionary power, respectively the power abuse in the activity of the state’s institutions. The legal behavior of the state’s institutions consists in their right to appreciate them and the power excess generates the violation of a subjective right or of the right that is of legitimate interest to the citizen. The application and nonobservance of the principle of lawfulness in the activities of the state is a complex problem because the exercise of the state’s functions assumes the discretionary powers with which the states authorities are invested, or otherwise said the ‘right of appreciation” of the authorities regarding the moment of adopting the contents of the measures proposed. The discretionary power cannot be opposed to the principle of lawfulness, as a dimension of the state de jure. In this study we propose to analyze the concept of discretionary power, respectively the power excess, having as a guidance the legislation, jurisprudence and doctrine in the matter. At the same time we would like to identify the most important criterions that will allow the user, regardless that he is or not an administrator, a public clerk or a judge, to delimit the legal behavior of the state’s institutions from the power excess. Within this context, we appreciate that the principle of proportionality represents such a criterion. The proportionality is a legal principle of the law, but at the same time it is a principle of the constitutional law and of other law branches. It expresses clearly the idea of balance, reasonability but also of adjusting the measures ordered by the state’s authorities to the situation in fact, respectively to the purpose for which they have been conceived. In our study we choose theoretical and jurisprudence arguments according to which the principle of proportionality can procedurally be determined and used to delimit the discretionary power and

  12. Low proportion of high school senior athletes receiving recommended immunizations.

    Science.gov (United States)

    Karpinos, Ashley Rowatt; Rizzone, Katherine H; Cribbs, Sarah P; Roumie, Christianne L

    2014-05-01

    The preparticipation physical evaluation (PPE) often serves as the only preventive health care visit for athletes, but immunization status is not uniformly addressed in such visits. Thus, athletes may not be receiving recommended immunizations. Our aim was to determine the proportion of high school senior athletes who received all recommended immunizations. Our hypothesis was that females would be less likely than males to receive all recommended immunizations given suboptimal human papillomavirus (HPV) vaccine uptake. We conducted a cross-sectional survey evaluation of the immunization status of high school senior athletes in Davidson County, TN. The primary composite outcome was receipt of recommended immunizations for tetanus, meningococcal, and seasonal influenza. For females, the primary outcome also included completion of the HPV series. A total of 162 participants, 104 males and 58 females, were included. More males than females received all recommended immunizations (15.4% vs 3.5%; P = 0.02). When HPV immunization was excluded from the composite outcome, there was no difference in the proportion of males and females who received all recommended immunizations (15.4% vs 15.5%; P = 0.98). The odds of receiving all recommended immunizations was 0.14 (95% CI, 0.03-0.72) for females compared with males when adjusted for covariates. Athletes seen at retail-based clinics for their PPE were less likely to receive all recommended immunizations compared with athletes seen in primary care (OR, 0.13; 95% CI, 0.02-0.69). Only 1 in 6 high school senior athletes received the recommended tetanus, meningococcal, and influenza immunizations. A lower proportion of females, only 1 in 28, received all recommended immunizations due to the HPV series. Policy changes requiring a review of immunizations at the PPE would benefit many high school athletes.

  13. A versatile gas-flow proportional counter for Moessbauer spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Bibicu, I., E-mail: bibicu@infim.ro [National Institute for Materials Physics (Romania); Nicolescu, G. [IFIN-HH, National Institute of Physics and Nuclear Engineering (Romania); Cretu, C. [Transylvania University, Physics Department (Romania)

    2009-07-15

    This article presents a versatile gas-flow proportional counter for surface and transmission Moessbauer spectroscopy, suitable for studies with {sup 57}Fe, {sup 119}Sn and {sup 151}Eu isotopes. The main advantages obtained by new design are: (1) the height of the detection volume can be changed in large limits from 0 to 38 mm, (2) the detection volume can be choose symmetrical or not in respect with anode plan, (3) the anode replacement is easily (4) and different anode configuration can be used. The characteristics of the detector, operating at room temperature, are reported.

  14. Proportional counter response calculations for gallium solar neutrino detectors

    International Nuclear Information System (INIS)

    Kouzes, R.T.; Reynolds, D.

    1989-01-01

    Gallium bases solar neutrino detectors are sensitive to the primary pp reaction in the sun. Two experiments using gallium, SAGE in the Soviet Union and GALLEX in Europe, are under construction and will produce data by 1989. The radioactive /sup 71/Ge produced by neutrinos interacting with the gallium detector material, is chemically extracted and counted in miniature proportional counters. A number of calculations have been carried out to simulate the response of these counters to the decay of /sup 71/Ge and to background events

  15. Xenon-based Penning mixtures for proportional counters

    International Nuclear Information System (INIS)

    Ramsey, B.D.; Agrawal, P.C.; National Aeronautics and Space Administration, Huntsville, AL

    1989-01-01

    The choice of quench gas can have a significant effect on the gas gain and energy resolution of gas-filed proportional counters. Details are given on the performance obtained with a variety of quench additives of varying ionization potentials for use in xenon-filled systems. It is confirmed that optimum performance is obtained when the ionization potential is closely matched to the first metastable level of xenon (8.3 eV) as is the case with xenon + trimethylamine and xenon + dimethylamine. For these mixtures the Penning effect is at its strongest. (orig.)

  16. A multiwire proportional counter for very high counting rates

    International Nuclear Information System (INIS)

    Barbosa, A.F.; Guedes, G.P.; Tamura, E.; Pepe, I.M.; Oliveira, N.B.

    1997-12-01

    Preliminary measurements in a proportional counter with two independently counting wires showed that counting rates up to 10 6 counts/s per wire can be reached without critical loss in the true versus measured linearity relation. Results obtained with a detector containing 30 active wires (2 mm pitch) are presented. To each wire is associated a fast pre-amplifier and a discriminator channel. Global counting rates in excess to 10 7 events/s are reported. Data acquisition systems are described for 1D (real time) and 2D (off-line) position sensitive detection systems. (author)

  17. Constant Proportion Portfolio Insurance Strategies in Contagious Markets

    DEFF Research Database (Denmark)

    Buccioli, Alice; Kokholm, Thomas

    2018-01-01

    charging and for risk management. The literature on CPPI modeling typically assumes diffusive or Lévy-driven dynamics for the risky asset underlying the strategy. In either case the self-contagious nature of asset prices is not taken into account. In order to account for contagion while preserving......Constant Proportion Portfolio Insurance (CPPI) strategies are popular as they allow to gear up the upside potential of a stock index while limiting its downside risk. From the issuer's perspective it is important to adequately assess the risks associated with the CPPI, both for correct "gap'' fee...

  18. A multiwire proportional counter for very high counting rates

    Energy Technology Data Exchange (ETDEWEB)

    Barbosa, A F; Guedes, G P [Centro Brasileiro de Pesquisas Fisicas (CBPF), Rio de Janeiro, RJ (Brazil); Tamura, E [Laboratorio Nacional de Luz Sincrotron (LNLS), Campinas, SP (Brazil); Pepe, I M; Oliveira, N B [Bahia Univ., Salvador, BA (Brazil). Inst. de Fisica

    1997-12-01

    Preliminary measurements in a proportional counter with two independently counting wires showed that counting rates up to 10{sup 6} counts/s per wire can be reached without critical loss in the true versus measured linearity relation. Results obtained with a detector containing 30 active wires (2 mm pitch) are presented. To each wire is associated a fast pre-amplifier and a discriminator channel. Global counting rates in excess to 10{sup 7} events/s are reported. Data acquisition systems are described for 1D (real time) and 2D (off-line) position sensitive detection systems. (author) 13 refs., 6 figs.

  19. Multi-element proportional counter for radiation protection measurements

    International Nuclear Information System (INIS)

    Kliauga, P.; Rossi, H.H.; Johnson, G.

    1988-01-01

    This article discusses design modifications of a multi-element proportional counter. The original counter exhibited poor resolution, as measured by the width of the event-size spectrum for low-energy photons. It was also suspected that the field inside each volume was not sufficiently symmetric. Results of the modifications showed that a dramatic improvement in resolution could be obtained in the chamber with tissue-equivalent septa if their potentials were adjusted to obtain optimal resolution. The full width at half maximum then approached, although it did not equal, that of a standard spherical counter

  20. Computer simulation of gain fluctuations in proportional counters

    International Nuclear Information System (INIS)

    Demir, Nelgun; Tapan, . Ilhan

    2004-01-01

    A computer simulation code has been developed in order to examine the fluctuation in gas amplification in wire proportional counters which are common in detector applications in particle physics experiments. The magnitude of the variance in the gain dominates the statistical portion of the energy resolution. In order to compare simulation and experimental results, the gain and its variation has been calculated numerically for the well known Aleph Inner Tracking Detector geometry. The results show that the bias voltage has a strong influence on the variance in the gain. The simulation calculations are in good agreement with experimental results. (authors)

  1. Proportional counter with uniform electric field with Penning's mixture

    International Nuclear Information System (INIS)

    Pawlowski, Z.; Marzec, J.; Zaremba, K.

    1984-01-01

    Some calculations are given and the design of proportional counters with a homogeneous electric field filled with Penning's mixtures, which ensure the best energy resolution is described. The counters with mixtures of Ne+Ar, Ne+CH 4 , Ne+CO 2 and Ar+C 2 H 2 have been checked. The admixtures (Ar, CH 4 , CO 2 , C 2 H 2 ) constitute from 0.1 to 2%, with pressure from 125 Tr to 760 Torr. The best energy resolution has been obtained for the mixture of Ne+1%CH 4 at the pressure of 190 Torr

  2. Energy resolution limitations in a gas scintillation proportional counter

    International Nuclear Information System (INIS)

    Simons, D.G.; de Korte, P.A.J.; Peacock, A.; Bleeker, J.A.M.

    1985-01-01

    An investigation is made of the factors limiting the energy resolution of a gas scintillation proportional counter (GSPC). Several of these limitations originate in the drift region of such a counter and data is presented, giving a quantitative description of those effects. Data is also presented of a GSPC without a drift region, that therefore largely circumvents most of those degrading factors. The results obtained so far indicate that in that detector the limitation to the resolution is most probably due to cleanliness of the gas. Further research is underway in order to assess quantitatively the limiting factors in such a driftless GSPC

  3. Golden Proportion in Frontal Social Smile from Orthodontic Viewpoint

    Directory of Open Access Journals (Sweden)

    z Tabatabaei

    2011-09-01

    Full Text Available Introduction: Physical attraction has a significant effect on all aspects of personal life, and in this category facial appearance is the most important part of the body in prediction of attractiveness. In the face, mouth and specially shape and size of anterior teeth is important to gain dental and facial esthetic. The aim of this study is evaluation of golden proportion from orthodontic view in maxillary anterior teeth in both sexes. Methods: Considering inclusion and exclusion criteria, 100 students of Rafsanjan University of Medical Sciences were selected, and photographs of their frontal social smile were taken by a standard method from 30cm distance. Then visible part of central, lateral and canine teeth was measured by Photoshop software (Adobe Photoshop ver8 with 0.1mm precision. Data was evaluated by descriptive statistical analysis and sample T-test using SPSS. Results: According to descriptive statistical analysis and sample T- test, mean ratio of central to lateral teeth in the left side in men and women was 1.209±0.199 and 1.157±0.156 and in the right side in men and women was 1.179± 0.27 and 1.158± 0.145, respectively. The ratio of lateral to canine teeth in the left side in men and women was 1.522±0.146 and 1.494±0.127 and in the right side in men and women was 1.55±0.164 and 1.51±0.114, respectively. Golden proportion was seen between central and lateral teeth in 16% in the right side and 3.4% in the left side only in men. Conclusion: Golden proportion was seen between central and lateral in the left side and right side in men, but due to large canine in men, this proportion was not seen between lateral and canine teeth and so due to small lateral in women, it was not seen between anterior teeth.

  4. Enhanced learning of proportional math through music training and spatial-temporal training.

    Science.gov (United States)

    Graziano, A B; Peterson, M; Shaw, G L

    1999-03-01

    It was predicted, based on a mathematical model of the cortex, that early music training would enhance spatial-temporal reasoning. We have demonstrated that preschool children given six months of piano keyboard lessons improved dramatically on spatial-temporal reasoning while children in appropriate control groups did not improve. It was then predicted that the enhanced spatial-temporal reasoning from piano keyboard training could lead to enhanced learning of specific math concepts, in particular proportional math, which is notoriously difficult to teach using the usual language-analytic methods. We report here the development of Spatial-Temporal Math Video Game software designed to teach fractions and proportional math, and its strikingly successful use in a study involving 237 second-grade children (age range six years eight months-eight years five months). Furthermore, as predicted, children given piano keyboard training along with the Math Video Game training scored significantly higher on proportional math and fractions than children given a control training along with the Math Video Game. These results were readily measured using the companion Math Video Game Evaluation Program. The training time necessary for children on the Math Video Game is very short, and they rapidly reach a high level of performance. This suggests that, as predicted, we are tapping into fundamental cortical processes of spatial-temporal reasoning. This spatial-temporal approach is easily generalized to teach other math and science concepts in a complementary manner to traditional language-analytic methods, and at a younger age. The neural mechanisms involved in thinking through fractions and proportional math during training with the Math Video Game might be investigated in EEG coherence studies along with priming by specific music.

  5. Social Markers of Mild Cognitive Impairment: Proportion of Word Counts in Free Conversational Speech.

    Science.gov (United States)

    Dodge, Hiroko H; Mattek, Nora; Gregor, Mattie; Bowman, Molly; Seelye, Adriana; Ybarra, Oscar; Asgari, Meysam; Kaye, Jeffrey A

    2015-01-01

    Detecting early signs of Alzheimer's disease (AD) and mild cognitive impairment (MCI) during the pre-symptomatic phase is becoming increasingly important for costeffective clinical trials and also for deriving maximum benefit from currently available treatment strategies. However, distinguishing early signs of MCI from normal cognitive aging is difficult. Biomarkers have been extensively examined as early indicators of the pathological process for AD, but assessing these biomarkers is expensive and challenging to apply widely among pre-symptomatic community dwelling older adults. Here we propose assessment of social markers, which could provide an alternative or complementary and ecologically valid strategy for identifying the pre-symptomatic phase leading to MCI and AD. The data came from a larger randomized controlled clinical trial (RCT), where we examined whether daily conversational interactions using remote video telecommunications software could improve cognitive functions of older adult participants. We assessed the proportion of words generated by participants out of total words produced by both participants and staff interviewers using transcribed conversations during the intervention trial as an indicator of how two people (participants and interviewers) interact with each other in one-on-one conversations. We examined whether the proportion differed between those with intact cognition and MCI, using first, generalized estimating equations with the proportion as outcome, and second, logistic regression models with cognitive status as outcome in order to estimate the area under ROC curve (ROC AUC). Compared to those with normal cognitive function, MCI participants generated a greater proportion of words out of the total number of words during the timed conversation sessions (p=0.01). This difference remained after controlling for participant age, gender, interviewer and time of assessment (p=0.03). The logistic regression models showed the ROC AUC of

  6. Ocean Physicochemistry versus Climate Change

    OpenAIRE

    Góralski, Bogdan

    2014-01-01

    It is the dwindling ocean productivity which leaves dissolved carbon dioxide in the seawater. Its solubility is diminished by the rise in ocean water temperature (by one degree Celsius since 1910, according to IPCC). Excess carbon dioxide is emitted into the atmosphere, while its growing concentration in seawater leads to ocean acidification. Ocean acidification leading to lowering pH of surface ocean water remains an unsolved problem of science. My today’s lecture will mark an attempt at ...

  7. Geothermal influences on the abyssal ocean

    Science.gov (United States)

    Emile-Geay, J.; Madec, G.

    2017-12-01

    Long considered a negligible contribution to ocean dynamics, geothermal heat flow (GHF) is now increasingly recognized as an important contributor to the large scale ocean's deep structure and circulation. This presentation will review the history of theories regarding geothermal influences on the abyssal ocean. Though the contribution to the thermal structure was recognized early on, its potential in driving a circulation [Worthington, 1968] was largely ignored on the grounds that it could not materially affect potential vorticity. Huang [JPO, 1999] proposed that GHF may provide 30-50% of the energy available for deep mixing, a calculation that later proved too optimistic [Wunsch & Ferrari ARFM 2004]. Model simulations suggested that a uniform GHF of 50 mW/m2 could drive an abyssal of a few Sverdrups (1 Sv = 106 m3.s-1) [Adcroft et al, GRL 2001], but it was not until Emile-Geay & Madec [OS, 2009] (EM09) that GHF began to be taken seriously [Mashayek et al, GRL 2013; Voldoire et al. Clim. Dyn. 2013; Dufresnes et al., Clim. Dyn. 2013]. Using analytical and numerical approaches, the study made 3 main points: GHF brings as much energy to the deep ocean as intense diapycnal mixing (1 cm2/s). GHF consumes the densest water masses, inducing a deep circulation of 5 Sv even without mixing. This circulation varies in inverse proportion to abyssal stratification. The spatial structure of GHF, highest at mid-ocean ridges and lowest in abyssal plains, matters far less than the fact that it bathes vast fractions of the ocean floor in a relatively low, constant flux. EM09 concluded that GHF "is an important actor of abyssal dynamics, and should no longer be neglected in oceanographic studies". Recent work has confirmed that geothermal heat flow is of comparable importance to ocean circulation as bottom-intensified mixing induced by internal wave breaking [De Lavergne et al, JPO 2016a,b]. Thus, including GHF in ocean general circulation models improves abyssal structure and

  8. Red ocean vs blue ocean strategies

    OpenAIRE

    Λαΐνος, Ιάσονας

    2011-01-01

    This paper is about the strategies that a company can adopt in order to get a competitive advantage over its rivals, and thus be successful (Red Ocean Strategies). We also tried to explain what actually entrepreneurship is, to be able to understand why the corporate strategies are formed as they do, and why companies are choosing to follow them. The following project is a part of our master thesis that we will present for the University of Piraeus for the MBA-TQM master department. The thesis...

  9. On timing properties of the SRPO-304 proportional counters

    International Nuclear Information System (INIS)

    Gusev, A.A.; Pugacheva, G.I.

    1979-01-01

    Data of measurements of the signal delay time and the time of development of the discharge in a proportional counter filled with 90% Xe + 10% CH 4 mixture at 0.3 atm are presented. The measurements were carried out on muons of cosmic rays. Signal delay distribution for the proportional counter are given relative to the time of passage through it of a charged particle. The data obtained shows that the average delay time is 0.8 μs when a particle passes near the counter centre, whereas when it passes near its side wall the average delay time is 1.5 μs. The investigation of the discharge development time distribution was carried out for two values of the discriminator threshold: 6 and 20 keV. It was determined that the discharge development time distribution depends but little on the place of particle passage in a counter. The average discharge development time is 1.5 μs, with the maximum time beina 4.3 μs. It is shown that the resolution time of logical circuits will be near 4 μs when the counter is combined with scintillation detectors

  10. Operability test procedure for 211BA flow proportional sampler

    International Nuclear Information System (INIS)

    Weissenfels, R.D.

    1994-01-01

    The purpose of this operability test procedure (OTP) is to verify the 211-BA flow proportional sampler system and components function correctly as intended by design. System test will include the sampling system, all associated instrumentation, and Facility Process Monitor and Control System (FPMCS). The combined chemical sewer stream from B Plant flows through sump 211BA-SMP-01 located in 211-BA and is continuously monitored for gamma and beta radiation and pH. 211-BA has been upgraded to include a flow proportional sampler. A specified sample volume will be withdrawn at programmed intervals from the 211BA sump and deposited in a 19 liter plastic carboy. The sampler will be programmed per the vendor installation and operations manual by B Plant instrument maintenance personnel. Samples will be taken during five consecutive sample cycles with the sample volumes and sample frequencies recorded for comparison purposes. Additional tests related to the sampler include the alarm circuitry for loss of power and failure to obtain sample

  11. The arcsine is asinine: the analysis of proportions in ecology.

    Science.gov (United States)

    Warton, David I; Hui, Francis K C

    2011-01-01

    The arcsine square root transformation has long been standard procedure when analyzing proportional data in ecology, with applications in data sets containing binomial and non-binomial response variables. Here, we argue that the arcsine transform should not be used in either circumstance. For binomial data, logistic regression has greater interpretability and higher power than analyses of transformed data. However, it is important to check the data for additional unexplained variation, i.e., overdispersion, and to account for it via the inclusion of random effects in the model if found. For non-binomial data, the arcsine transform is undesirable on the grounds of interpretability, and because it can produce nonsensical predictions. The logit transformation is proposed as an alternative approach to address these issues. Examples are presented in both cases to illustrate these advantages, comparing various methods of analyzing proportions including untransformed, arcsine- and logit-transformed linear models and logistic regression (with or without random effects). Simulations demonstrate that logistic regression usually provides a gain in power over other methods.

  12. The oceanic sediment barrier

    International Nuclear Information System (INIS)

    Francis, T.J.G.; Searle, R.C.; Wilson, T.R.S.

    1986-01-01

    Burial within the sediments of the deep ocean floor is one of the options that have been proposed for the disposal of high-level radioactive waste. An international research programme is in progress to determine whether oceanic sediments have the requisite properties for this purpose. After summarizing the salient features of this programme, the paper focuses on the Great Meteor East study area in the Northeast Atlantic, where most oceanographic effort has been concentrated. The geological geochemical and geotechnical properties of the sediments in the area are discussed. Measurements designed to determine the rate of pore water movement through the sediment column are described. Our understanding of the chemistry of both the solid and pore-water phases of the sediment are outlined, emphasizing the control that redox conditions have on the mobility of, for example, naturally occurring manganese and uranium. The burial of instrumented free-fall penetrators to depths of 30 m beneath the ocean floor is described, modelling one of the methods by which waste might be emplaced. Finally, the nature of this oceanic environment is compared with geological environments on land and attention is drawn to the gaps in our knowledge that must be filled before oceanic burial can be regarded as an acceptable disposal option. (author)

  13. The ocean planet.

    Science.gov (United States)

    Hinrichsen, D

    1998-01-01

    The Blue Planet is 70% water, and all but 3% of it is salt water. Life on earth first evolved in the primordial soup of ancient seas, and though today's seas provide 99% of all living space on the planet, little is known about the world's oceans. However, the fact that the greatest threats to the integrity of our oceans come from land-based activities is becoming clear. Humankind is in the process of annihilating the coastal and ocean ecosystems and the wealth of biodiversity they harbor. Mounting population and development pressures have taken a grim toll on coastal and ocean resources. The trend arising from such growth is the chronic overexploitation of marine resources, whereby rapidly expanding coastal populations and the growth of cities have contributed to a rising tide of pollution in nearly all of the world's seas. This crisis is made worse by government inaction and a frustrating inability to enforce existing coastal and ocean management regulations. Such inability is mainly because concerned areas contain so many different types of regulations and involve so many levels of government, that rational planning and coordination of efforts are rendered impossible. Concerted efforts are needed by national governments and the international community to start preserving the ultimate source of all life on earth.

  14. Impact of intrauterine growth retardation and body proportionality on fetal and neonatal outcome.

    Science.gov (United States)

    Kramer, M S; Olivier, M; McLean, F H; Willis, D M; Usher, R H

    1990-11-01

    Previous prognostic studies of infants with intrauterine growth retardation (IUGR) have not adequately considered the heterogeneity of IUGR in terms of cause, severity, and body proportionality and have been prone to misclassification of IUGR because of errors in estimation of gestational age. Based on a cohort of 8719 infants with early-ultrasound-validated gestational ages and indexes of body proportionality standardized for birth weight, the consequences of severity and cause-specific IUGR and proportionality for fetal and neonatal morbidity and mortality were assessed. With progressive severity of IUGR, there were significant (all P less than .001) linear trends for increasing risks of stillbirth, fetal distress (abnormal electronic fetal heart tracings)O during parturition, neonatal hypoglycemia (minimum plasma glucose less than 40 mg/dL), hypocalcemia (minimum Ca less than 7 mg/dL), polycythemia (maximum capillary hemoglobin greater than or equal to 21 g/dL), severe depression at birth (manual ventilation greater than 3 minutes), 1-minute and 5-minute Apgar scores less than or equal to 6, 1-minute Apgar score less than or equal to 3, and in-hospital death. These trends persisted for the more common outcomes even after restriction to term (37 to 42 weeks) births. There was no convincing evidence that outcome among infants with a given degree of growth retardation varied as a function of cause of that growth retardation. Among infants with IUGR, increased length-for-weight had significant crude associations with hypoglycemia and polycythemia, but these associations disappeared after adjustment for severity of growth retardation and gestational age.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Ocean acoustic tomography

    International Nuclear Information System (INIS)

    Cornuelle, Bruce D; Worcester, Peter F; Dzieciuch, Matthew A

    2008-01-01

    Ocean acoustic tomography (OAT) was proposed in 1979 by Walter Munk and Carl Wunsch as an analogue to x-ray computed axial tomography for the oceans. The oceans are opaque to most electromagnetic radiation, but there is a strong acoustic waveguide, and sound can propagate for 10 Mm and more with distinct multiply-refracted ray paths. Transmitting broadband pulses in the ocean leads to a set of impulsive arrivals at the receiver which characterize the impulse response of the sound channel. The peaks observed at the receiver are assumed to represent the arrival of energy traveling along geometric ray paths. These paths can be distinguished by arrival time, and by arrival angle when a vertical array of receivers is available. Changes in ray arrival time can be used to infer changes in ocean structure. Ray travel time measurements have been a mainstay of long-range acoustic measurements, but the strong sensitivity of ray paths to range-dependent sound speed perturbations makes the ray sampling functions uncertain in real cases. In the ray approximation travel times are sensitive to medium changes only along the corresponding eigenrays. Ray theory is an infinite-frequency approximation, and its eikonal equation has nonlinearities not found in the acoustic wave equation. We build on recent seismology results (kernels for body wave arrivals in the earth) to characterize the kernel for converting sound speed change in the ocean to travel time changes using more complete propagation physics. Wave-theoretic finite frequency kernels may show less sensitivity to small-scale sound speed structure.

  16. Are oceanic plateaus sites of komatiite formation?

    Science.gov (United States)

    Storey, M.; Mahoney, J. J.; Kroenke, L. W.; Saunders, A. D.

    1991-04-01

    During Cretaceous and Tertiary time a series of oceanic terranes were accreted onto the Pacific continental margin of Colombia. The island of Gorgona is thought to represent part of the most recent, early Eocene, terrane-forming event. Gorgona is remarkable for the occurrence of komatiites of middle Cretaceous age, having MgO contents up to 24%. The geochemistry of spatially and temporally associated tholeiites suggests that Gorgona is an obducted fragment of the oceanic Caribbean Plateau, postulated by Duncan and Hargraves (1984) to have formed at 100 to 75 Ma over the Galapagos hotspot. Further examples of high-MgO oceanic lavas that may represent fragments of the Caribbean Plateau occur in allochthonous terranes on the island of Curaçao in the Netherlands Antilles and in the Romeral zone ophiolites in the southwestern Colombian Andes. These and other examples suggest that the formation of high-MgO liquids may be a feature of oceanic-plateau settings. The association of Phanerozoic komatiites with oceanic plateaus, coupled with thermal considerations, provides a plausible analogue for the origin of some komatiite-tholeiite sequences in Archean greenstone belts.

  17. Lagrangian ocean analysis: Fundamentals and practices

    Science.gov (United States)

    van Sebille, Erik; Griffies, Stephen M.; Abernathey, Ryan; Adams, Thomas P.; Berloff, Pavel; Biastoch, Arne; Blanke, Bruno; Chassignet, Eric P.; Cheng, Yu; Cotter, Colin J.; Deleersnijder, Eric; Döös, Kristofer; Drake, Henri F.; Drijfhout, Sybren; Gary, Stefan F.; Heemink, Arnold W.; Kjellsson, Joakim; Koszalka, Inga Monika; Lange, Michael; Lique, Camille; MacGilchrist, Graeme A.; Marsh, Robert; Mayorga Adame, C. Gabriela; McAdam, Ronan; Nencioli, Francesco; Paris, Claire B.; Piggott, Matthew D.; Polton, Jeff A.; Rühs, Siren; Shah, Syed H. A. M.; Thomas, Matthew D.; Wang, Jinbo; Wolfram, Phillip J.; Zanna, Laure; Zika, Jan D.

    2018-01-01

    Lagrangian analysis is a powerful way to analyse the output of ocean circulation models and other ocean velocity data such as from altimetry. In the Lagrangian approach, large sets of virtual particles are integrated within the three-dimensional, time-evolving velocity fields. Over several decades, a variety of tools and methods for this purpose have emerged. Here, we review the state of the art in the field of Lagrangian analysis of ocean velocity data, starting from a fundamental kinematic framework and with a focus on large-scale open ocean applications. Beyond the use of explicit velocity fields, we consider the influence of unresolved physics and dynamics on particle trajectories. We comprehensively list and discuss the tools currently available for tracking virtual particles. We then showcase some of the innovative applications of trajectory data, and conclude with some open questions and an outlook. The overall goal of this review paper is to reconcile some of the different techniques and methods in Lagrangian ocean analysis, while recognising the rich diversity of codes that have and continue to emerge, and the challenges of the coming age of petascale computing.

  18. Chapter 1. Impacts of the oceans on climate change.

    Science.gov (United States)

    Reid, Philip C; Fischer, Astrid C; Lewis-Brown, Emily; Meredith, Michael P; Sparrow, Mike; Andersson, Andreas J; Antia, Avan; Bates, Nicholas R; Bathmann, Ulrich; Beaugrand, Gregory; Brix, Holger; Dye, Stephen; Edwards, Martin; Furevik, Tore; Gangstø, Reidun; Hátún, Hjálmar; Hopcroft, Russell R; Kendall, Mike; Kasten, Sabine; Keeling, Ralph; Le Quéré, Corinne; Mackenzie, Fred T; Malin, Gill; Mauritzen, Cecilie; Olafsson, Jón; Paull, Charlie; Rignot, Eric; Shimada, Koji; Vogt, Meike; Wallace, Craig; Wang, Zhaomin; Washington, Richard

    2009-01-01

    The oceans play a key role in climate regulation especially in part buffering (neutralising) the effects of increasing levels of greenhouse gases in the atmosphere and rising global temperatures. This chapter examines how the regulatory processes performed by the oceans alter as a response to climate change and assesses the extent to which positive feedbacks from the ocean may exacerbate climate change. There is clear evidence for rapid change in the oceans. As the main heat store for the world there has been an accelerating change in sea temperatures over the last few decades, which has contributed to rising sea-level. The oceans are also the main store of carbon dioxide (CO2), and are estimated to have taken up approximately 40% of anthropogenic-sourced CO2 from the atmosphere since the beginning of the industrial revolution. A proportion of the carbon uptake is exported via the four ocean 'carbon pumps' (Solubility, Biological, Continental Shelf and Carbonate Counter) to the deep ocean reservoir. Increases in sea temperature and changing planktonic systems and ocean currents may lead to a reduction in the uptake of CO2 by the ocean; some evidence suggests a suppression of parts of the marine carbon sink is already underway. While the oceans have buffered climate change through the uptake of CO2 produced by fossil fuel burning this has already had an impact on ocean chemistry through ocean acidification and will continue to do so. Feedbacks to climate change from acidification may result from expected impacts on marine organisms (especially corals and calcareous plankton), ecosystems and biogeochemical cycles. The polar regions of the world are showing the most rapid responses to climate change. As a result of a strong ice-ocean influence, small changes in temperature, salinity and ice cover may trigger large and sudden changes in regional climate with potential downstream feedbacks to the climate of the rest of the world. A warming Arctic Ocean may lead to

  19. Mixtures of organic and inorganic substrates, particle size and proportion.

    Directory of Open Access Journals (Sweden)

    Emilio Raymundo Morales-Maldonado

    2015-06-01

    Full Text Available The objective of this paper was to review the mixtures of organic and inorganic materials used in the preparation of a new material, particle size, proportion, and their response in plant. In Mexico, agricultural waste is considered as a pollutant reservoir; however, from another perspective, this represents an industry with great potential. The nutrients ingested by animals represent nutriments available for plants when properly recycled. An option that minimizes the risk of contamination and improves its quality is the production of compost and vermicompost. Both processes are an alternative to organic production. A material by itself does not meet the optimum conditions. Reducing the volume of an organic material increases compaction and compression of roots, affecting the efficiency of irrigation and fertilization, so it is necessary to make mixtures with inorganic materials, that is used in the development of a new material for better growing conditions of the plant.

  20. Performance of fine grained photon position detector using proportional tubes

    International Nuclear Information System (INIS)

    Artemiev, V.; Galaktionov, Y.; Gordeev, A.; Gorodkov, Y.; Kamishkov, Y.; Lubimov, V.; Plyaskin, V.; Pojidaev, V.; Shevchenko, V.; Shumilov, E.; Bamberger, A.; Fuchs, M.; Giesen, G.; Heck, W.; Ludwig, J.; Marx, R.; Mocken, T.; Runge, K.; Skodzek, E.; Weber, H.C.; Weltin, A.; Wuelker, M.

    1984-01-01

    As part of the NA24 experiment at the CERN-SPS a photon position detector serves to separate direct photons from abundantly produced π 0 decay photons: electromagnetic showers are measured with an energy- and position-resolution sufficiently good to give a two-gamma resolving power of 1.2 cm. The shower detector covers 3 x 3 m 2 and consists of 12 layers of triangular proportional tubes (7.73 mm pitch) sandwiched with lead (altogether 9.6 X 0 ). For eight layers the analog information is provided by an ADC system. Ambiguities are resolved by the digital information of four additional layers inclined by 45 0 . Prototypes were built in order to test gas mixtures and electronics. The electromagnetic shower development in the PPD and the prototypes are reproduced by Monte Carlo calculations. The homogeneity of the PPD has been checked by calibration measurements. (orig.)

  1. Determination of dose equivalent with tissue-equivalent proportional counters

    International Nuclear Information System (INIS)

    Dietze, G.; Schuhmacher, H.; Menzel, H.G.

    1989-01-01

    Low pressure tissue-equivalent proportional counters (TEPC) are instruments based on the cavity chamber principle and provide spectral information on the energy loss of single charged particles crossing the cavity. Hence such detectors measure absorbed dose or kerma and are able to provide estimates on radiation quality. During recent years TEPC based instruments have been developed for radiation protection applications in photon and neutron fields. This was mainly based on the expectation that the energy dependence of their dose equivalent response is smaller than that of other instruments in use. Recently, such instruments have been investigated by intercomparison measurements in various neutron and photon fields. Although their principles of measurements are more closely related to the definition of dose equivalent quantities than those of other existing dosemeters, there are distinct differences and limitations with respect to the irradiation geometry and the determination of the quality factor. The application of such instruments for measuring ambient dose equivalent is discussed. (author)

  2. Design of nuclear pulse shaped circuit based on proportional counter

    International Nuclear Information System (INIS)

    Song Qianqian; Cheng Yi; Tuo Xianguo

    2011-01-01

    Use the self-developed proportional to sample gas tritium in environment and make the measurement. For this detector, a kind of pulse shape circuit based on second order active low pass filtering circuit realized filtering and shaping nuclear pulse by high-speed operational amplifier, with less stages that has been approved for filter Gaussian wave. Use Multisim 10.0 to simulate the different parameters of the filter circuit. The simulation result was consistent with the theoretical results. The experiments proved the feasibility of this circuit, and at the same time provided a convenient and reliable method for analysis and optimization of the nuclear pulse waveform in order for discriminating by MCA. (authors)

  3. Nitrogen large area proportional counter with gas regeneration

    International Nuclear Information System (INIS)

    Leidner, L.; Sadri, E.

    1984-10-01

    A nitrogen large area proportional chamber with gas regeneration is introduced to measure alpha and beta/gamma activites. In contrast to the flow counters used till now the new detector is independent of an external gas supply. The gas amplification factor of nitrogen keeps constant up to an impurity of 2% of O 2 . Oxygen diffusing through unavoidable leakages into the counting gas is removed by an activated catalyzer using low temperature copper oxidation. Humidty is adsorbed by a molecular sieve. The closed counter consists of three components: the actual detector, a gas purification cartridge and a gas circulating pump. Finally, the report describes long run experiments being carried out with prototypes. (orig./HP) [de

  4. Functional form diagnostics for Cox's proportional hazards model.

    Science.gov (United States)

    León, Larry F; Tsai, Chih-Ling

    2004-03-01

    We propose a new type of residual and an easily computed functional form test for the Cox proportional hazards model. The proposed test is a modification of the omnibus test for testing the overall fit of a parametric regression model, developed by Stute, González Manteiga, and Presedo Quindimil (1998, Journal of the American Statistical Association93, 141-149), and is based on what we call censoring consistent residuals. In addition, we develop residual plots that can be used to identify the correct functional forms of covariates. We compare our test with the functional form test of Lin, Wei, and Ying (1993, Biometrika80, 557-572) in a simulation study. The practical application of the proposed residuals and functional form test is illustrated using both a simulated data set and a real data set.

  5. Mixtures of organic and inorganic substrates, particle size and proportion

    International Nuclear Information System (INIS)

    Morales-Maldonado, Emilio Raymundo; Casanova-Lugo, Fernando

    2015-01-01

    The mixtures of organic and inorganic materials used in the preparation of a new material, particle size, proportion and their response in plant were reviewed. Agricultural wastes are considered a pollutant reservoir in Mexico; however, for another perspective this represent an industry with great potential. The nutrients ingested by animals represent nutriments available for plants when properly recycled. The production of compost and vermicompost is an option that minimize the risk of contamination and improve quality. Both processes are an alternative for organic production. The efficiency of irrigation and fertilization are affected for the reducing the volumen of an organic material incresase compaction and compression of roots. The mixtures with inorganic materials are used in the development of a new material to obtain better growing conditions for the plant. (author) [es

  6. Imaging performance of a multiwire proportional-chamber positron camera

    International Nuclear Information System (INIS)

    Perez-Mandez, V.; Del Guerra, A.; Nelson, W.R.; Tam, K.C.

    1982-08-01

    A new design - fully three-dimensional - Positron Camera is presented, made of six MultiWire Proportional Chamber modules arranged to form the lateral surface of a hexagonal prism. A true coincidence rate of 56000 c/s is expected with an equal accidental rate for a 400 μCi activity uniformly distributed in a approx. 3 l water phantom. A detailed Monte Carlo program has been used to investigate the dependence of the spatial resolution on the geometrical and physical parameters. A spatial resolution of 4.8 mm FWHM has been obtained for a 18 F point-like source in a 10 cm radius water phantom. The main properties of the limited angle reconstruction algorithms are described in relation to the proposed detector geometry

  7. The suppression of destructive sparks in parallel plate proportional counters

    Energy Technology Data Exchange (ETDEWEB)

    Cockshott, R.A.; Mason, I.M.

    1984-02-01

    The authors find that high energy background events produce localised sparks in parallel plate counters when operated in the proportional mode. These sparks increase dead-time and lead to degradation ranging from electrode damage to spurious pulsing and continuous breakdown. The problem is particularly serious in low energy photon detectors for X-ray astronomy which are required to have lifetimes of several years in the high radiation environment of space. For the parallel plate imaging detector developed for the European X-ray Observatory Satellite (EXOSAT) they investigate quantitatively the spark thresholds, spark rates and degradation processes. They discuss the spark mechanism, pointing out differences from the situation in spark chambers and counters. They show that the time profile of the sparks allows them to devise a spark suppression system which reduces the degradation rate by a factor of ''200.

  8. Design of pneumatic proportional flow valve type 5/3

    Science.gov (United States)

    Laski, P. A.; Pietrala, D. S.; Zwierzchowski, J.; Czarnogorski, K.

    2017-08-01

    In this paper the 5/3-way pneumatic, proportional flow valve was designed and made. Stepper linear actuator was used to move the spool. The valve is controlled by the controlled based on a AVR microcontroller. Virtual model of the valve was created in CAD. The real element was made based on a standard 5/3-way manually actuated valve with hand lever, which was dismounted and replaced by linear stepper motor. All the elements was mounted in a specially made housing. The controller consists of microcontroller Atmega16, integrated circuit L293D, display, two potentiometers, three LEDs and six buttons. Series of research was also conducted. Simulation research were performed using CFD by the Flow Simulation addition to SolidWorks. During the experiments the valve characteristics of flow and pressure was determined.

  9. A Bayesian equivalency test for two independent binomial proportions.

    Science.gov (United States)

    Kawasaki, Yohei; Shimokawa, Asanao; Yamada, Hiroshi; Miyaoka, Etsuo

    2016-01-01

    In clinical trials, it is often necessary to perform an equivalence study. The equivalence study requires actively denoting equivalence between two different drugs or treatments. Since it is not possible to assert equivalence that is not rejected by a superiority test, statistical methods known as equivalency tests have been suggested. These methods for equivalency tests are based on the frequency framework; however, there are few such methods in the Bayesian framework. Hence, this article proposes a new index that suggests the equivalency of binomial proportions, which is constructed based on the Bayesian framework. In this study, we provide two methods for calculating the index and compare the probabilities that have been calculated by these two calculation methods. Moreover, we apply this index to the results of actual clinical trials to demonstrate the utility of the index.

  10. Application of multiwire proportional chamber in BEPC test beam

    International Nuclear Information System (INIS)

    Shen Ji; Chen Ziyu; Ye Yunxiu; Cuiu Xiangzong; Li Jiacai

    2006-01-01

    This paper describes a Multiwire Proportional Chamber (MWPC) for the Test Beam on BEPC (Beijing Electron Positron Colider). The distance between the anode surface and the cathode surface of the MWPC is 6 mm. Both surfaces are made of gold-plated tungsten wires, the anode wires are 20 μm in diameter and 2 mm apart, and the cathode wires are 50 μm indiameter and 0.7 mm apart. Six adjacent wires are connected together to form a 4.2 mm wide cathode strip. The MWPC can localize the particles of e, π by cathode-induced charge centre-of-gravity read-out. For 5.9 keV γ photon, the positional resolution is less than 0.3 mm (FWHM) and for 1.1 GeV beam electron, 0.224 mm (FWHM) positional resolution is attained. (authors)

  11. Use of proportional tubes in a muon polarimeter

    International Nuclear Information System (INIS)

    Kenney, C.J.; Eckhause, M.; Ginkel, J.F.

    1988-01-01

    A prototype muon polarimeter was built to study the feasibility of measuring the positive muon polarization in the decay K/sub L/ → μ + μ/sup /minus//. The system consisted of alternating layers of extruded aluminum gas proportional tubes and polarization-retaining absorber plates of either aluminum or marble. Longitudinally polarized positive muons from the Stopped Muon Channel at the Clinton P. Anderson Meson Physics Facility (LAMPF) were stopped in the absorber plates where they precessed in a field of 60 gauss. Decay times were recorded in 100 ns first-in-first-out memories for all wires hit during a 12.8 μs period centered about the muon stop trigger. The performance of the system was studied for different beam rates and absorber thicknesses. The value of imposing time and spacial cuts on track data to enhance the precession signal was also investigated. 7 refs., 4 figs., 1 tab

  12. A Praxeological Study of Proportionality in Mathematics Lower Secondary Textbooks

    DEFF Research Database (Denmark)

    Wijayanti, Dyana

    Research on the uses and contents of mathematics textbooks has expanded over the past decades, due to the central role textbooks occupy in mathematics teaching worldwide. However, the methodology of analysing the texts themselves often appears underdeveloped or even naïve, especially when it comes...... to specific mathematical content. The central idea of this thesis is to deploy the anthropological theory of the didactic, and especially the notion of praxeology, to analyse how textbooks treat three specific and related areas (or more precisely, sectors) of mathematical contents for lower secondary school......, namely "proportion and ratio" (in Arithmetic), "similar plane figures" (in Geometry), and "linear functions" (in Algebra). This leads to a new and very precise methodological tool for analysing the practices (types of tasks, techniques) supported by the textbooks through examples, explanations...

  13. Pressure control of hydraulic servo system using proportional control valve

    International Nuclear Information System (INIS)

    Yang, Kyong Uk; Oh, In Ho; Lee, Ill Yeong

    1999-01-01

    The purpose of this study is to develop a control scheme for the hydraulic servo system which can rapidly control the pressure in a hydraulic cylinder with very short stroke. Compared with the negligible stroke of the cylinder in the system, the flow gain of the proportional pressure control valve constituting the hydraulic servo system is relatively large and the time delay on the response of the valve is quite long. Therefore, the pressure control system, in this study tends to get unstable during operations. Considering the above mentioned characteristics of the system, a two-degree-of-freedom control scheme, composed of the I-PDD 2 ... feedback compensator and the feedforward controller, is proposed. The reference model scheme is used in deciding the parameters of the controllers. The validity of the proposed control scheme is confirmed through the experiments

  14. Optimization of simultaneous tritium–radiocarbon internal gas proportional counting

    Energy Technology Data Exchange (ETDEWEB)

    Bonicalzi, R. M.; Aalseth, C. E.; Day, A. R.; Hoppe, E. W.; Mace, E. K.; Moran, J. J.; Overman, C. T.; Panisko, M. E.; Seifert, A.

    2016-03-01

    Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill of P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium counting efficiency while minimizing radiocarbon beta decay interference.

  15. Industrial defectoscope based on multiwire proportional chamber in CAMAC system

    International Nuclear Information System (INIS)

    Brzeski, P.; Kazubek, M.; Mirkowski, J.; Szabatin, R.

    1976-01-01

    The defectoscope for non-destructive testing has been built at the Institute of Radioelectronics in collaboration with the Electrotechnical Institute, Non-destructive Division. The defectoscope consists of the following parts: gamma radiation detector, multiwire proportional chamber with γ-e converter, preamplifier system attached directly to the chamber wires, logic module of CAMAC philoscopy, and MERA 300 minicomputer. The defectoscope is used to detect material flaws in tested objects, irradiated from an internal radiation source. Minicomputer used enables data processing. The data collected in mincomputer memory are the radiological image of a tested object. It is possible to display the collected image on a television monitor, to display any profile of the image on an oscilloscope, to print the map of the image on a mosaic printer. (author)

  16. A Modified Proportional Navigation Guidance for Accurate Target Hitting

    Directory of Open Access Journals (Sweden)

    A. Moharampour

    2010-03-01

    First, the pure proportional navigation guidance (PPNG in 3-dimensional state is explained in a new point of view. The main idea is based on the distinction between angular rate vector and rotation vector conceptions. The current innovation is based on selection of line of sight (LOS coordinates. A comparison between two available choices for LOS coordinates system is proposed. An improvement is made by adding two additional terms. First term includes a cross range compensator which is used to provide and enhance path observability, and obtain convergent estimates of state variables. The second term is new concept lead bias term, which has been calculated by assuming an equivalent acceleration along the target longitudinal axis. Simulation results indicate that the lead bias term properly provides terminal conditions for accurate target interception.

  17. Estimation of the false discovery proportion with unknown dependence.

    Science.gov (United States)

    Fan, Jianqing; Han, Xu

    2017-09-01

    Large-scale multiple testing with correlated test statistics arises frequently in many scientific research. Incorporating correlation information in approximating false discovery proportion has attracted increasing attention in recent years. When the covariance matrix of test statistics is known, Fan, Han & Gu (2012) provided an accurate approximation of False Discovery Proportion (FDP) under arbitrary dependence structure and some sparsity assumption. However, the covariance matrix is often unknown in many applications and such dependence information has to be estimated before approximating FDP. The estimation accuracy can greatly affect FDP approximation. In the current paper, we aim to theoretically study the impact of unknown dependence on the testing procedure and establish a general framework such that FDP can be well approximated. The impacts of unknown dependence on approximating FDP are in the following two major aspects: through estimating eigenvalues/eigenvectors and through estimating marginal variances. To address the challenges in these two aspects, we firstly develop general requirements on estimates of eigenvalues and eigenvectors for a good approximation of FDP. We then give conditions on the structures of covariance matrices that satisfy such requirements. Such dependence structures include banded/sparse covariance matrices and (conditional) sparse precision matrices. Within this framework, we also consider a special example to illustrate our method where data are sampled from an approximate factor model, which encompasses most practical situations. We provide a good approximation of FDP via exploiting this specific dependence structure. The results are further generalized to the situation where the multivariate normality assumption is relaxed. Our results are demonstrated by simulation studies and some real data applications.

  18. Boosted PWM open loop control of hydraulic proportional valves

    International Nuclear Information System (INIS)

    Amirante, R.; Innone, A.; Catalano, L.A.

    2008-01-01

    This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots

  19. Boosted PWM open loop control of hydraulic proportional valves

    Energy Technology Data Exchange (ETDEWEB)

    Amirante, R.; Catalano, L.A. [Dipartimento di Ingegneria Meccanica e Gestionale, Politecnico di Bari, Via Re David 200, 70125 Bari (Italy); Innone, A. [Universita degli Studi di Foggia, via Napoli, 25 Foggia (Italy)

    2008-08-15

    This paper presents an innovative open loop control technique for direct single stage hydraulic proportional valves whose response rate is significantly higher than that obtained by standard open loop control techniques, even comparable to more costly commercial closed loop systems. Different from standard open loop techniques, which provide the coil with a constant current proportional to the target position, the control strategy proposed in this paper employs the peak and hold (P and H) technique, widely used in Diesel engine modern supply systems, to boost the duty cycle value of the pulse width modulation (PWM) signal for a short time, namely during the spool displacement, while maintaining a lower duty cycle for holding the spool in the required opening position. The developed 'boosted PWM' technique only requires a low cost microcontroller, such as a peripheral interface controller (PIC) equipped with a metal oxide semiconductor (MOS) power driver. The PWM parameters are calibrated as a function of the spool displacement so as to maximize the response rate without introducing overshoots: the collected data are stored in the PIC. Different valve opening procedures with step response have been compared to demonstrate the merits of the proposed boosted PWM technique. No overshoots have been registered. Moreover, the proposed method is characterized by a significantly higher response rate with respect to a standard open loop control, which approximately has the same cost. Similar experimental tests show that the proposed boosted PWM technique has a response rate even higher than that provided by the more costly commercial closed loop system mounted on the valve, and it produces no overshoots. (author)

  20. A Partial Proportional Odds Model for Pedestrian Crashes at Mid-Blocks in Melbourne Metropolitan Area

    Directory of Open Access Journals (Sweden)

    Toran Pour Alireza

    2016-01-01

    Full Text Available Pedestrian crashes account for 11% of all reported traffic crashes in Melbourne metropolitan area between 2004 and 2013. There are very limited studies on pedestrian accidents at mid-blocks. Mid-block crashes account for about 46% of the total pedestrian crashes in Melbourne metropolitan area. Meanwhile, about 50% of all pedestrian fatalities occur at mid-blocks. In this research, Partial Proportional Odds (PPO model is applied to examine vehicle-pedestrian crash severity at mid-blocks in Melbourne metropolitan area. The PPO model is a logistic regression model that allows the covariates that meet the proportional odds assumption to affect different crash severity levels with the same magnitude; whereas the covariates that do not meet the proportional odds assumption can have different effects on different severity levels. In this research vehicle-pedestrian crashes at mid-blocks are analysed for first time. In addition, some factors such as distance of crashes to public transport stops, average road slope and some social characteristics are considered to develop the model in this research for first time. Results of PPO model show that speed limit, light condition, pedestrian age and gender, and vehicle type are the most significant factors that influence vehicle-pedestrian crash severity at mid-blocks.

  1. The critical proportion of immune individuals needed to control hepatitis B

    Science.gov (United States)

    Ospina, Juan; Hincapié-Palacio, Doracelly

    2016-05-01

    We estimate the critical proportion of immunity (Pc) to control hepatitis B in Medellin - Colombia, based on a random population survey of 2077 individuals of 6-64 years of age. The force of infection (Fi) was estimated according to empirical data of susceptibility by age S(a), assuming a quadratic expression. Parameters were estimated by adjusting data to a nonlinear regression. Fi was defined by -(ds(a)/da)/s(a) and according to the form of the empirical curve S(a) we assume a quadratic expression given by S(a)= Ea2+Ba+C. Then we have the explicit expression for the accumulated Fi by age given by F(a) = -a(Ea+B)/c. The expression of average infection age A is obtained as A = L + EL3/(3C)+BL2/(2C) and the basic reproductive number R0 is obtained as R0 = 1 + 6C/(6C+2EL2+3BL). From the las result we obtain the Pc given by Pc= 6C/(12C+2EL2+3BL). Numerical simulations were performed with the age-susceptibility proportion and initial values (a=0.02, b=20, c=100), obtaining an adjusted coefficient of multiple determination of 64.83%. According to the best estimate, the algebraic expressions for S(a) and the Fi were derived. Using the result of Fi, we obtain A = 30, L =85; R0 CI 95%: 1.42 - 1.64 and Pc: 0-0.29. These results indicate that at the worst case, to maintain control of the disease should be immunes at least 30% of susceptible individuals. Similar results were obtained by sex and residential area.

  2. Meta-analyses of the proportion of Japanese encephalitis virus infection in vectors and vertebrate hosts.

    Science.gov (United States)

    Oliveira, Ana R S; Cohnstaedt, Lee W; Strathe, Erin; Hernández, Luciana Etcheverry; McVey, D Scott; Piaggio, José; Cernicchiaro, Natalia

    2017-09-07

    Japanese encephalitis (JE) is a zoonosis in Southeast Asia vectored by mosquitoes infected with the Japanese encephalitis virus (JEV). Japanese encephalitis is considered an emerging exotic infectious disease with potential for introduction in currently JEV-free countries. Pigs and ardeid birds are reservoir hosts and play a major role on the transmission dynamics of the disease. The objective of the study was to quantitatively summarize the proportion of JEV infection in vectors and vertebrate hosts from data pertaining to observational studies obtained in a systematic review of the literature on vector and host competence for JEV, using meta-analyses. Data gathered in this study pertained to three outcomes: proportion of JEV infection in vectors, proportion of JEV infection in vertebrate hosts, and minimum infection rate (MIR) in vectors. Random-effects subgroup meta-analysis models were fitted by species (mosquito or vertebrate host species) to estimate pooled summary measures, as well as to compute the variance between studies. Meta-regression models were fitted to assess the association between different predictors and the outcomes of interest and to identify sources of heterogeneity among studies. Predictors included in all models were mosquito/vertebrate host species, diagnostic methods, mosquito capture methods, season, country/region, age category, and number of mosquitos per pool. Mosquito species, diagnostic method, country, and capture method represented important sources of heterogeneity associated with the proportion of JEV infection; host species and region were considered sources of heterogeneity associated with the proportion of JEV infection in hosts; and diagnostic and mosquito capture methods were deemed important contributors of heterogeneity for the MIR outcome. Our findings provide reference pooled summary estimates of vector competence for JEV for some mosquito species, as well as of sources of variability for these outcomes. Moreover, this

  3. Low Proportion of Dietary Plant Protein among Athletes with Premenstrual Syndrome-Related Performance Impairment.

    Science.gov (United States)

    Yamada, Keiko; Takeda, Takashi

    2018-02-01

    Premenstrual syndrome (PMS) is psychosomatic disorder that are limited to the late luteal phase in the menstrual cycle. PMS could impair athletic performance. To investigate associations between proportions of dietary plant and animal protein and PMS-related impairment of athletic performance, we surveyed 135 female athletes aged 18-23 years attending Kindai University. Participants belonged to authorized university clubs, all of which have high rankings in Japanese university sports. Participants completed self-administered questionnaires on diet history, demographics, and PMS-related impairment of athletic performance. Total protein, animal protein, and plant protein intake were examined, and the proportion of dietary plant protein was calculated for each participant. We divided athletes into two groups: those without PMS-related impairment of athletic performance (n = 117) and those with PMS-related performance impairment (n = 18). A t-test was used to compare mean values and multivariable adjusted mean values between groups; adjustment variables were energy intake, body mass index, and daily training duration. Total protein intake was not significantly different between the groups. However, athletes whose performance was affected by PMS reported higher intake of animal protein (mean 50.6 g) than athletes whose performance was unaffected by PMS (mean 34.9 g). Plant protein intake was lower among athletes with PMS-related impairment (mean 25.4 g) than among athletes without impairment (mean 26.9 g). The proportion of dietary plant protein was lower among athletes with PMS-related impairment (39.3%) than those without impairment (45.9%). A low proportion of dietary plant protein may cause PMS-related athletic impairment among athletes.

  4. Reduced Th22 cell proportion and prevention of atopic dermatitis in infants following maternal probiotic supplementation.

    Science.gov (United States)

    Rø, A D B; Simpson, M R; Rø, T B; Storrø, O; Johnsen, R; Videm, V; Øien, T

    2017-08-01

    In the randomized, controlled study Probiotics in the Prevention of Allergy among Children in Trondheim (ProPACT), maternal probiotic supplementation reduced the incidence of atopic dermatitis (AD) in the offspring. In the current study, we hypothesized that the effect was mediated by a shift in the T helper (Th) cells in the children. To examine whether Th cell proportions were affected by maternal probiotic supplementation and thus could mediate the preventive effect of probiotics on AD. A total of 415 pregnant women were randomized to ingest a combination of Lactobacillus rhamnosus GG (LGG), Bifidobacterium animalis subsp. lactis Bb-12 (Bb-12) and Lactobacillus acidophilus La-5 (La-5) or placebo, and their offspring were assessed for AD during the first 2 years of life. Peripheral blood collected at 3 months of age was analysed for regulatory T cells (n=140) and Th subsets (n=77) including Th1, Th2, Th9, Th17 and Th22. The proportion of Th22 cells was reduced in children in the probiotic group compared to the placebo group (median 0.038% vs 0.064%, P=.009). The difference between the probiotic and placebo groups was also observed in the children who did not develop AD during the 2-year follow-up. The proportion of Th22 cells was increased in children who developed AD compared to the children who did not develop AD (0.090% vs 0.044%, Pprobiotics was partially mediated through the reduction in Th22 cells. Perinatal maternal probiotic supplementation with a combination of LGG, Bb-12 and La-5 reduced the proportion of Th22 cells in 3-month-old children. This may partially explain the preventive effect of probiotics on AD. © 2017 John Wiley & Sons Ltd.

  5. Vertical Motions of Oceanic Volcanoes

    Science.gov (United States)

    Clague, D. A.; Moore, J. G.

    2006-12-01

    Oceanic volcanoes offer abundant evidence of changes in their elevations through time. Their large-scale motions begin with a period of rapid subsidence lasting hundreds of thousands of years caused by isostatic compensation of the added mass of the volcano on the ocean lithosphere. The response is within thousands of years and lasts as long as the active volcano keeps adding mass on the ocean floor. Downward flexure caused by volcanic loading creates troughs around the growing volcanoes that eventually fill with sediment. Seismic surveys show that the overall depression of the old ocean floor beneath Hawaiian volcanoes such as Mauna Loa is about 10 km. This gross subsidence means that the drowned shorelines only record a small part of the total subsidence the islands experienced. In Hawaii, this history is recorded by long-term tide-gauge data, the depth in drill holes of subaerial lava flows and soil horizons, former shorelines presently located below sea level. Offshore Hawaii, a series of at least 7 drowned reefs and terraces record subsidence of about 1325 m during the last half million years. Older sequences of drowned reefs and terraces define the early rapid phase of subsidence of Maui, Molokai, Lanai, Oahu, Kauai, and Niihau. Volcanic islands, such as Maui, tip down toward the next younger volcano as it begins rapid growth and subsidence. Such tipping results in drowned reefs on Haleakala as deep as 2400 m where they are tipped towards Hawaii. Flat-topped volcanoes on submarine rift zones also record this tipping towards the next younger volcano. This early rapid subsidence phase is followed by a period of slow subsidence lasting for millions of years caused by thermal contraction of the aging ocean lithosphere beneath the volcano. The well-known evolution along the Hawaiian chain from high to low volcanic island, to coral island, and to guyot is due to this process. This history of rapid and then slow subsidence is interrupted by a period of minor uplift

  6. An Ocean of Possibilities

    Science.gov (United States)

    Williams, Doug

    2010-01-01

    For more than one hundred years teachers have paddled beside the great ocean of mathematical adventure. Between them they have taught millions of young people. A few have dived in and kept swimming, some have lingered on the shore playing in pools, but most have dipped their toes in and run like heck in the other direction never to return. There…

  7. Deep Water Ocean Acoustics

    Science.gov (United States)

    2016-12-22

    roughly 28°S. The second is the Hawaiian Island Chain, extending to Midway Island at 28°N, 177°W and finally the Emperor Seamount chain running due...dimension array centered near Ascension. The climatology ocean (WOA09) showed very little seasonal dependence or change from the geodesic and this is

  8. Enhanced Ocean Scatterometry

    NARCIS (Netherlands)

    Fois, F.

    2015-01-01

    An ocean scatterometer is an active microwave instrument which is designed to determine the normalized radar cross section (NRCS) of the sea surface. Scatterometers transmit pulses towards the sea surface and measure the reflected energy. The primary objective of spaceborne scatterometers is to

  9. Power from Ocean Waves.

    Science.gov (United States)

    Newman, J. N.

    1979-01-01

    Discussed is the utilization of surface ocean waves as a potential source of power. Simple and large-scale wave power devices and conversion systems are described. Alternative utilizations, environmental impacts, and future prospects of this alternative energy source are detailed. (BT)

  10. Investigating Ocean Pollution.

    Science.gov (United States)

    LeBeau, Sue

    1998-01-01

    Describes a fifth-grade class project to investigate two major forms of ocean pollution: plastics and oil. Students work in groups and read, discuss, speculate, offer opinions, and participate in activities such as keeping a plastics journal, testing the biodegradability of plastics, and simulating oil spills. Activities culminate in…

  11. Ocean Dumping Control Act

    International Nuclear Information System (INIS)

    1975-01-01

    This Act provides for the control of dumping of wastes and other substances in the ocean in accordance with the London Convention of 1972 on Prevention of Marine Pollution by the Dumping of Wastes and other Matter to which Canada is a Party. Radioactive wastes are included in the prohibited and restricted substances. (NEA)

  12. The effect of flooding on soil proportion and plant growth. 2. Its effect on the changes in soil proportion

    International Nuclear Information System (INIS)

    Sisworo, E.L.

    1975-01-01

    An experiment has been carried out to study changes in soil proportion as affected by flooding. Barley plants were used as indicators. Black polyethylene columns were used as plant containers, and were filled with sandy loam Begbroke soil. Several parameters were used in the experiment, namely concentrations of oxygen carbon dioxide, ethylene, hydrogen sulfide, and organic acids. Oxygen concentration dropped to about 2% one day after flooding, while the concentration of carbon dioxide, ethylene and organic acids turned out to be slowly increased with the extension of flooding time. No hydrogen sulfide was detectable as affected by various flooding periods. Different concentrations of oxygen, carbon dioxide, and ethylene were observed between the top and the lower layers of soil. (author)

  13. Zoogeography of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Rao, T.S.S.

    The distribution pattern of zooplankton in the Indian Ocean is briefly reviewed on a within and between ocean patterns and is limited to species within a quite restricted sort of groups namely, Copepoda, Chaetognatha, Pteropoda and Euphausiacea...

  14. World Ocean Atlas 2005, Temperature

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Ocean Atlas 2005 (WOA05) is a set of objectively analyzed (1° grid) climatological fields of in situ temperature, salinity, dissolved oxygen, Apparent Oxygen...

  15. OW CCMP Ocean Surface Wind

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Cross-Calibrated Multi-Platform (CCMP) Ocean Surface Wind Vector Analyses (Atlas et al., 2011) provide a consistent, gap-free long-term time-series of monthly...

  16. OW ASCAT Ocean Surface Winds

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Advanced Scatterometer (ASCAT) sensor onboard the EUMETSAT MetOp polar-orbiting satellite provides ocean surface wind observations by means of radar...

  17. World Ocean Atlas 2005, Salinity

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — World Ocean Atlas 2005 (WOA05) is a set of objectively analyzed (1° grid) climatological fields of in situ temperature, salinity, dissolved oxygen, Apparent Oxygen...

  18. Satellite Ocean Heat Content Suite

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This collection contains an operational Satellite Ocean Heat Content Suite (SOHCS) product generated by NOAA National Environmental Satellite, Data, and Information...

  19. ocean_city_md.grd

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — NGDC builds and distributes high-resolution, coastal digital elevation models (DEMs) that integrate ocean bathymetry and land topography to support NOAA's mission to...

  20. Proportion and clinical features of never-smokers with non-small cell lung cancer.

    Science.gov (United States)

    Cho, Jaeyoung; Choi, Sun Mi; Lee, Jinwoo; Lee, Chang-Hoon; Lee, Sang-Min; Kim, Dong-Wan; Yim, Jae-Joon; Kim, Young Tae; Yoo, Chul-Gyu; Kim, Young Whan; Han, Sung Koo; Park, Young Sik

    2017-02-08

    The proportion of never-smokers with non-small cell lung cancer (NSCLC) is increasing, but that in Korea has not been well addressed in a large population. We aimed to evaluate the proportion and clinical features of never-smokers with NSCLC in a large single institution. We analyzed clinical data of 1860 consecutive patients who were newly diagnosed with NSCLC between June 2011 and December 2014. Of the 1860 NSCLC patients, 707 (38.0%) were never-smokers. The proportions of women (83.7% vs. 5.6%) and adenocarcinoma (89.8% vs. 44.9%) were higher among never-smokers than among ever-smokers. Significantly more never-smokers were diagnosed at a younger median age (65 vs. 68 years, P smokers. Epidermal growth factor receptor mutations (57.8% vs. 24.4%, P never-smokers, whereas Kirsten rat sarcoma viral oncogene homolog mutations (5.8% vs. 9.6%, P = 0.021) were less frequently encountered in never-smokers than in ever-smokers. Never-smokers showed longer survival after adjusting for the favorable effects of younger age, female sex, adenocarcinoma histology, better performance status, early stage disease, being asymptomatic at diagnosis, received antitumor treatment, and the presence of driver mutations (hazard ratio, 0.624; 95% confidence interval, 0.460-0.848; P = 0.003). More than one-third of the Korean patients with NSCLC were never-smokers. NSCLC in never-smokers had different clinical characteristics and major driver mutations and resulted in longer overall survival compared with NSCLC in ever-smokers.

  1. Femoral neck-shaft angle and climate-induced body proportions.

    Science.gov (United States)

    Child, Stephanie L; Cowgill, Libby W

    2017-12-01

    Declination in femoral neck-shaft angle (NSA) is commonly linked to an increased level of physical activity during life. More recently, however, research suggests that lower NSA might also be explained, in part, as the mechanical consequence of differences in ecogeographic body proportions. This study tests the proposed link between NSA and climatic-induced body proportions, using relative body mass (RBM), throughout the course of development. NSA and RBM were collected for 445 immature remains from five geographic locations. NSA and RBM were standardized for age-effects. ANOVA was used to examine when population differences emerged in both NSA and RBM. Regression analyses were used to examine the pattern of relationship between NSA and RBM. Populations differ significantly in NSA and RBM before skeletal maturity, and these differences occur early in life. While both NSA and RBM change over the course of development, no significant relationship was found between NSA and RBM for any sample, or any age category (p = .244). Individuals who have relatively greater relative body mass do not necessarily have lower NSA. Population differences in NSA were found to be variable, while differences in RBM remained consistent across the developmental span. Taken together, these results suggest that regardless of body proportions, the degree of declination of NSA is presumed to be similar among individuals with similar gait and ambulatory behaviors. Conversely, populations differ in RBM from birth, and these differences are consistent throughout development. These two measures likely are responsive to diffing stimuli, and any potential relationship is likely complex and multifactorial. © 2017 Wiley Periodicals, Inc.

  2. Increased proportion of megafibers in chronically painful muscles

    DEFF Research Database (Denmark)

    Andersen, Lars L; Suetta, Charlotte; Andersen, Jesper L

    2008-01-01

    . The percentage of megafibers was positively related to age and weekly working hours, indicating an effect of long-term exposure. In conclusion, this study shows that trapezius myalgia is associated with a significantly higher percentage of grossly hypertrophied type I muscle fibers with poor capillarization...

  3. Molar incisor hypomineralization: proportion and severity in primary public school children in Graz, Austria.

    Science.gov (United States)

    Buchgraber, Barbara; Kqiku, Lumnije; Ebeleseder, Kurt A

    2018-03-01

    The aim of this study was to determine the proportion and severity of molar incisor hypomineralization (MIH) in primary school children in Graz (southeast of Austria). In 1111 children aged 6 to 12 years (mean age 9.0 ± 1.2), a wet examination of all teeth was performed by three trained examiners using a dental chair, optimal illumination, a dental mirror, and a dental explorer. All teeth with MIH lesions were registered so that different definitions of MIH were applicable. According to the European Academy of Pediatric Dentistry criteria that were considered valid at the time of the investigation, MIH was diagnosed when at least one first primary molar (FPM) was affected. MIH was present in 78 children (7.0%). In 64 children (5.8%), at least one molar and one incisor were affected (so-called M + IH). Additionally, in 9 children, only incisors were affected. In 7 affected children, teeth other than FPMs and incisors had MIH lesions. Almost an equal number of males (38) and females (40) were affected. The upper and lower molars were equally affected. The upper incisors were more frequently affected than the lower ones. Demarcated enamel opacities were the predominant types of defects. The proportion of MIH was 7.0% in Graz, which is similar to other comparable trials. This study has proven that MIH is an existing dental problem in Graz.

  4. Calibration of an ultra-low-background proportional counter for measuring 37Ar

    International Nuclear Information System (INIS)

    Seifert, A.; Aalseth, C. E.; Bonicalzi, R. M.; Bowyer, T. W.; Day, A. R.; Fuller, E. S.; Haas, D. A.; Hayes, J. C.; Hoppe, E. W.; Humble, P. H.; Keillor, M. E.; LaFerriere, B. D.; Mace, E. K.; McIntyre, J. I.; Merriman, J. H.; Miley, H. S.; Myers, A. W.; Orrell, J. L.; Overman, C. T.; Panisko, M. E.

    2013-01-01

    An ultra-low-background proportional counter design has been developed at Pacific Northwest National Laboratory (PNNL) using clean materials, primarily electro-chemically-purified copper. This detector, along with an ultra-low-background counting system (ULBCS), was developed to complement a new shallow underground laboratory (30 meters water-equivalent) at PNNL. The ULBCS design includes passive neutron and gamma shielding, along with an active cosmic-veto system. This system provides a capability for making ultra-sensitive measurements to support applications like age-dating soil hydrocarbons with 14 C/ 3 H, age-dating of groundwater with 39 Ar, and soil-gas assay for 37 Ar to support On-Site Inspection (OSI). On-Site Inspection is a key component of the verification regime for the Comprehensive Nuclear-Test-Ban Treaty (CTBT). Measurements of radionuclides created by an underground nuclear explosion are valuable signatures of a Treaty violation. For OSI, the 35-day half-life of 37 Ar, produced from neutron interactions with calcium in soil, provides both high specific activity and sufficient time for inspection before decay limits sensitivity. This work describes the calibration techniques and analysis methods developed to enable quantitative measurements of 37 Ar samples over a broad range of proportional counter operating pressures. These efforts, along with parallel work in progress on gas chemistry separation, are expected to provide a significant new capability for 37 Ar soil gas background studies

  5. Multiwire proportional chamber with a supporting line on anode wires

    International Nuclear Information System (INIS)

    Viktorov, V.A.; Golovkin, S.V.

    1980-01-01

    Results are presented of experimental investigations on a supporting line (wire) used in large-sized proportional chambers to compensate for electrostatic forces. The length of anode wires (gilded tungsten of 0.02 mm in diameter) in the chamber constituted 600 mm, the pitch 2 mm, the total number of channels 192. High-voltage electrodes are made of Cu-Be wire of 0.1 mm in diameter, the pitch is 2 mm. The gap between anode and cathode plates is 6 mm. The supporting line is an enamelled nichrome wire of 0.2 mm in diameter enclosed in an additional fluoroplastic insulation. The outside diameter was equal to 0.4 mm. The supporting line was placed through the centre of the chamber at right angles and immediately adjacent to anode wires with the tension of 2000 g. A negative compensating potential was applied to it. The controllable parameter was the chamber efficiency at variable paAameters: (1) an operating voltage in the chamber; (2) Vsub(c) - a compensating potential of the supporting line, and (3) a beam axis relative coordinate. The performed investigations showed that the supporting line of this type is simple and reliable in operation (electric breakdown occurs at Vsub(c) > 3.5 kV). The noneffective zone in the supporting region can be reduced to approximately 2.4 mm which constitutes approximately 0.3% of the chamber total sensitive region

  6. Low energy recoil detection with a spherical proportional counter

    Science.gov (United States)

    Savvidis, I.; Katsioulas, I.; Eleftheriadis, C.; Giomataris, I.; Papaevangellou, T.

    2018-01-01

    We present results for the detection of low energy nuclear recoils in the keV energy region, from measurements performed with the Spherical Proportional Counter (SPC). An 241Am-9Be fast neutron source is used in order to obtain neutron-nucleus elastic scattering events inside the gaseous volume of the detector. The detector performance in the keV energy region was measured by observing the 5.9 keV line of a 55Fe X-ray source, with energy resolution of 10% (σ). The toolkit GEANT4 was used to simulate the irradiation of the detector by an 241Am-9Be source, while SRIM was used to calculate the Ionization Quenching Factor (IQF), the simulation results are compared with the measurements. The potential of the SPC in low energy recoil detection makes the detector a good candidate for a wide range of applications, including Supernova or reactor neutrino detection and Dark Matter (WIMP) searches (via coherent elastic scattering).

  7. Medical applications of multi-wire proportional chambers

    International Nuclear Information System (INIS)

    Reading, D.H.

    1976-05-01

    The adaption of Multi-Wire Proportional Chambers (MWPC) for medical applications has necessitated bi-dimensional readout. This is achieved by analysing signals induced onto the cathode planes. At a useful X-ray energy of 40 to 45 keV, just above the K absorption edge in Xenon, the efficiency and resolution are both optimized. Poor resolution events due to K shell fluorescent capture and Auger emission, or L shell photo-electron emission, may be rejected by using energy discrimination - resulting in approximately halving the efficiency to 8% for a 1.6 cm thick atmospheric pressure chamber, but with sub millimeter inherent resolution. This is still far inferior to film resolution, but the MWPC is useful when numbers are required for computation or retrieval. Short descriptions of the MWPC applications to bone density measurements and tomography are given. Its use when pressurized as a gamma camera is discussed, and it is concluded that it may prove useful as a portable special purpose camera, or as one with a very large area thus compensating for low efficiency. Developments with liquid filled chambers are given and also the promising positron imaging hybrid MWPC. (author)

  8. Flexible proportional-rate scheduling for OFDMA system

    KAUST Repository

    Leith, Alex

    2013-10-01

    In this paper, we study the sum-rate maximization algorithms for downlink and uplink orthogonal frequency division multiple access (OFDMA) systems under proportional-rate constraint (PRC) and minimum-rate constraint. We develop a low-complexity weighted channel signal-to-noise ratio (w-SNR)-based ranking scheme for user selection on each subchannel in OFDMA combined with waterfilling (WF) power allocation. Both offline and online optimization algorithms are developed to optimize the SNR weight vector to maximize the sum rate while satisfying several constraints, such as PRC. The offline weight optimization technique relies on the analytical throughput results developed in this paper, and the online weight adaptation method tracks the user rates and meets the PRC using a subgradient search. Furthermore, we introduce a novel SNR operating region test to enhance the multiuser diversity gain and the sum rate. The proposed schemes have a low complexity, which is linear to the numbers of users and subchannels. Simulation results verify the accuracy of the developed analytical rates and fairness formulas, and show that the proposed w-SNR schemes can achieve higher sum rates than several benchmark schemes that provide the PRC with either short-term or long-term fairness. © 2013 IEEE. © 2013 ESO.

  9. Digital signal processing for He3 proportional counter

    International Nuclear Information System (INIS)

    Zeynalov, Sh.S.; Ahmadov, Q.S.

    2010-01-01

    Full text : Data acquisition systems for nuclear spectroscopy have traditionally been based on systems with analog shaping amplifiers followed by analog-to-digital converters. Recently, however, new systems based on digital signal processing make possible to replace the analog shaping and timing circuitry the numerical algorithms to derive properties of the pulse such as its amplitude. DSP is a fully numerical analysis of the detector pulse signals and this technique demonstrates significant advantages over analog systems in some circumstances. From a mathematical point of view, one can consider the signal evolution from the detector to the ADC as a sequence of transformations that can be described by precisely defined mathematical expressions. Digital signal processing with ADCs has the possibility to utilize further information on the signal pulses from radiation detectors. In the experiment each step of the signal generation in the 3He filled proportional counter was described using digital signal processing techniques (DSP). The electronic system has consisted of a detector, a preamplifier and a digital oscilloscope. The pulses from the detector were digitized using a digital storage oscilloscope. This oscilloscope allowed signal digitization with accuracy of 8 bit (256 levels) and with frequency of up to 5 * 10 8 samples/s. As a neutron source was used Cf-252. To obtain detector output current pulse I(t) created by the motions of the ions/electrons pairs was written an algorithm which can easily be programmed using modern computer programming languages.

  10. Finishing procedures in Orthodontics: dental dimensions and proportions (microesthetics

    Directory of Open Access Journals (Sweden)

    Roberto Carlos Bodart Brandão

    2013-10-01

    Full Text Available OBJECTIVE: The objective of the present article is to describe procedures that can be performed to achieve excellence in orthodontic treatment finishing. The content is limited to microesthetics, which comprises the concept of ideal dental dimensions and proportions (white esthetics and its correlation with the periodontium (pink esthetics. Standards of normality are described both in their real dimensions (dental height and width, and in those effectively perceived by the observer, the virtual dimensions. METHODS: The best scientific evidence was sought in the literature to support the clinical procedures that must guide the professional to obtain maximum esthetic quality on their treatments. Therefore, it is necessary to investigate what the other specialties in Dentistry expect from Orthodontics and, specially, what they have to offer. Clinical cases will be used to illustrate the dental movement that might maximize treatment outcome and to confront the ideal standards with the current state of the art. CONCLUSION: Treatment quality is directly related to the amount of procedures implemented by the orthodontist, associated with concepts and resources from Periodontics and Dental Prosthesis. Microesthetics cannot be seen in isolation, but rather as the key to establish a pleasant smile (miniesthetics in addition to a harmonious face (macroesthetics and a human being with high self-esteem (hyper-esthetics.

  11. Use of the helium-3 proportional counter for neutron spectrometry

    International Nuclear Information System (INIS)

    Vialettes, H.; Le Thanh, P.

    1967-01-01

    Up to now, two methods have been mainly used for neutron spectrometry near nuclear installations: - photographic emulsion spectrometry - the so-called, 'multisphere' technique spectrometry. The first method, which is fairly difficult to apply, has a threshold energy of about 500 keV; this is a big disadvantage for an apparatus which has to be used for spectrometry around nuclear installations where the neutron radiation is very much degraded energetically. The second method does not suffer from this disadvantage but the results which it yields are only approximate. In order to extend the energy range of the neutron spectra studied with sufficient accuracy the use of a helium-3 proportional counter has been considered. This report presents the principles of operation of the helium-3 spectrometer, and the calculation methods which make it possible to take into account the two main effects tending to deform the spectra obtained: - energy absorption by the walls of the counter, - energy loss of the incident neutrons due to elastic collisions with helium-3 nuclei. As an example of the application, the shape of the neutron spectrum emitted by a polonium-lithium source is given; the results obtained are in excellent agreement with theoretical predictions. (authors) [fr

  12. Conflicts between domestic inequality and global poverty: lexicality versus proportionality

    Directory of Open Access Journals (Sweden)

    Francisco García Gibson

    2016-12-01

    Full Text Available Current views on global justice often hold that affluent states are under at least two duties: a duty to reduce socioeconomic inequalities at home and a duty to reduce extreme poverty abroad. Potential duty conflicts deriving from resource scarcity can be solved in broadly two principled ways. The ‘lexical’ principle requires all disputed resources to be allocated to the weightiest duty. The ‘proportionality’ principle requires resources to be distributed between the two duties according to their relative weight (the weightiest duty receives the largest resource share, but the less weighty duty receives a share too. I argue that the proportionality principle is morally preferable. I show that it is sensitive to a number of factors that are intuitively relevant when solving duty conflicts: the number of affected individuals, the size of the benefits each individual could get, and the time it could take to eventually comply with the less weighty duty. Some argue that the lexical principle should nevertheless be preferred because domestic egalitarian duties are duties of justice, and they are therefore lexically prior to mere humanitarian duties to reduce global poverty. I reject this view by showing that duties of justice are not necessarily lexically prior to humanitarian duties, and that (even if they were duties to reduce global poverty can be regarded as duties of justice too.

  13. The European ‘Nomofilachia’ and the Principle of Proportionality

    Directory of Open Access Journals (Sweden)

    Antonio BARONE

    2009-12-01

    Full Text Available *The European Court of Justice greatly contributes to the guarantees that Community law will be uniformly interpreted and applied (“nomofilachia” and the rights which individuals derive from the Community legal order will be effectively protected. This essay analyses some aspects of the European Union “nomofilachia”; the research is developed in two steps which are strictly correlated. In the first part, it will be underlined how the uniform interpretation and the uniform application of EC law go beyond the provisions of art. 234 of the EC Treat; and are supported by new kind of relations among the Court of Justice, national courts and national administrations. In the second part of the research, it will be highlighted the impact of the general principles of the European Community legal system, moulded through the “nomofilachia” function of the Luxembourg Court, as regards the activities of national administrations. The analysis gives a particular attention to the evolutionary dynamics of the proportionality principle. All these aspects work in a contemporary context of deep transformation of the traditional relations among law, courts, administrations and citizens. * This essay is the joint work of both authors with Barone primary responsible for paragraph 1,2,3,4,9 and Ansaldi for paragraph 5,6,7,8.

  14. Optimization of simultaneous tritium–radiocarbon internal gas proportional counting

    Energy Technology Data Exchange (ETDEWEB)

    Bonicalzi, R.M. [Seattle Central College, 1701 Broadway, Seattle, WA 98122 (United States); Aalseth, C.E.; Day, A.R.; Hoppe, E.W. [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352 (United States); Mace, E.K., E-mail: Emily.Mace@pnl.gov [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352 (United States); Moran, J.J.; Overman, C.T.; Panisko, M.E.; Seifert, A. [Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352 (United States)

    2016-03-21

    Specific environmental applications can benefit from dual tritium and radiocarbon measurements in a single compound. Assuming typical environmental levels, it is often the low tritium activity relative to the higher radiocarbon activity that limits the dual measurement. In this paper, we explore the parameter space for a combined tritium and radiocarbon measurement using a natural methane sample mixed with an argon fill gas in low-background proportional counters of a specific design. We present an optimized methane percentage, detector fill pressure, and analysis energy windows to maximize measurement sensitivity while minimizing count time. The final optimized method uses a 9-atm fill of P35 (35% methane, 65% argon), and a tritium analysis window from 1.5 to 10.3 keV, which stops short of the tritium beta decay endpoint energy of 18.6 keV. This method optimizes tritium-counting efficiency while minimizing radiocarbon beta-decay interference. - Highlights: • Use of a single compound (methane) for dual tritium and radiocarbon measurements. • Optimized analysis window for simultaneous tritium and radiocarbon measurement. • Allows for optimization of tritium counting in the presence of radiocarbon.

  15. Flexible proportional-rate scheduling for OFDMA system

    KAUST Repository

    Leith, Alex; Alouini, Mohamed-Slim; Kim, Dongin; (Sherman) Shen X., Xuemin; Wu, Zhiqiang

    2013-01-01

    In this paper, we study the sum-rate maximization algorithms for downlink and uplink orthogonal frequency division multiple access (OFDMA) systems under proportional-rate constraint (PRC) and minimum-rate constraint. We develop a low-complexity weighted channel signal-to-noise ratio (w-SNR)-based ranking scheme for user selection on each subchannel in OFDMA combined with waterfilling (WF) power allocation. Both offline and online optimization algorithms are developed to optimize the SNR weight vector to maximize the sum rate while satisfying several constraints, such as PRC. The offline weight optimization technique relies on the analytical throughput results developed in this paper, and the online weight adaptation method tracks the user rates and meets the PRC using a subgradient search. Furthermore, we introduce a novel SNR operating region test to enhance the multiuser diversity gain and the sum rate. The proposed schemes have a low complexity, which is linear to the numbers of users and subchannels. Simulation results verify the accuracy of the developed analytical rates and fairness formulas, and show that the proposed w-SNR schemes can achieve higher sum rates than several benchmark schemes that provide the PRC with either short-term or long-term fairness. © 2013 IEEE. © 2013 ESO.

  16. Substantial proportion of global streamflow less than three months old

    Science.gov (United States)

    Jasechko, Scott; Kirchner, James W.; Welker, Jeffrey M.; McDonnell, Jeffrey J.

    2016-02-01

    Biogeochemical cycles, contaminant transport and chemical weathering are regulated by the speed at which precipitation travels through landscapes and reaches streams. Streamflow is a mixture of young and old precipitation, but the global proportions of these young and old components are not known. Here we analyse seasonal cycles of oxygen isotope ratios in rain, snow and streamflow compiled from 254 watersheds around the world, and calculate the fraction of streamflow that is derived from precipitation that fell within the past two or three months. This young streamflow accounts for about a third of global river discharge, and comprises at least 5% of discharge in about 90% of the catchments we investigated. We conclude that, although typical catchments have mean transit times of years or even decades, they nonetheless can rapidly transmit substantial fractions of soluble contaminant inputs to streams. Young streamflow is less prevalent in steeper landscapes, which suggests they are characterized by deeper vertical infiltration. Because young streamflow is derived from less than 0.1% of global groundwater storage, we conclude that this thin veneer of aquifer storage will have a disproportionate influence on stream water quality.

  17. Out of proportion pulmonary hypertension in obstructive lung diseases.

    Science.gov (United States)

    Chatterjee, Kshitij; Tarawneh, Ahmad R; Alam, Shoaib

    2018-03-01

    Pulmonary hypertension is common (25-90%) in chronic obstructive pulmonary diseases (COPDs). Severe pulmonary hypertension, however, is quite rare (1-3%). The term 'out of proportion' pulmonary hypertension is still widely used. New guidelines instead propose to use the term 'Severe pulmonary hypertension' if mean pulmonary arterial pressure at least 35 mmHg or cardiac index (CI) is less than 2.0 l/min/m on right heart catheterization (RHC). Why only a minority of COPD patients develop severe pulmonary hypertension is unclear. When present, severe pulmonary hypertension in COPD is associated with increased dyspnea and decreased survival and often does not closely correlate with degree of obstructive abnormality on pulmonary function testing. COPD patients with severe pulmonary hypertension experience circulatory limitation at maximum exercise, and not ventilatory limitation, which is typical for moderate-to-severe COPD patients with no or moderate pulmonary hypertension. There is no conclusive evidence to support or completely reject the possibility of the use of specific pulmonary arterial hypertension (PAH) therapies in pulmonary hypertension associated with COPD. In mild-to-moderate COPD patients who have severe and progressive symptoms, and have evidence of severe pulmonary hypertension on RHC, specific PAH therapies may be used similar to WHO group-I PAH guidelines.

  18. Tides. Ocean Related Curriculum Activities.

    Science.gov (United States)

    Marrett, Andrea

    The ocean affects all of our lives. Therefore, awareness of and information about the interconnections between humans and oceans are prerequisites to making sound decisions for the future. Project ORCA (Ocean Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…

  19. Energy from rivers and oceans

    International Nuclear Information System (INIS)

    Anon.

    1992-01-01

    This chapter discusses the role energy from rivers and oceans may have in the energy future of the US. The topics discussed in the chapter include historical aspects of using energy from rivers and oceans, hydropower assessment including resources, technology and costs, and environmental and regulatory issues, ocean thermal energy conversion including technology and costs and environmental issues, tidal power, and wave power

  20. 78 FR 32556 - Safety Zone; 2013 Ocean City Air Show, Atlantic Ocean; Ocean City, MD

    Science.gov (United States)

    2013-05-31

    ... FR Federal Register NPRM Notice of Proposed Rulemaking A. Regulatory History and Information The... Atlantic Ocean in Ocean City, MD. In recent years, there have been unfortunate instances of jets and planes...

  1. NCEI Standard Product: World Ocean Database (WOD)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The World Ocean Database (WOD) is the world's largest publicly available uniform format quality controlled ocean profile dataset. Ocean profile data are sets of...

  2. Digital signal processing for He3 proportional counter

    International Nuclear Information System (INIS)

    Ahmadov, Q.S.; Institute of Radiation Problems, ANAS, Baku

    2011-01-01

    Full text: Data acquisition systems for nuclear spectroscopy have traditionally been based on systems with analog shaping amplifiers followed by analog-to-digital converters. Recently, however, new systems based on digital signal processing allow us to replace the analog shaping and timing circuitry the numerical algorithms to derive properties of the pulse such as its amplitude. DSP is a fully numerical analysis of the detector pulse signals and this technique demonstrates significant advantages over analog systems in some circumstances. From a mathematical point of view, one can consider the signal evolution from the detector to the ADC as a sequence of transformations that can be described by precisely defined mathematical expressions.Digital signal processing with ADCs has the possibility to utilize further information on the signal pulses from radiation detectors [1] [2]. In the experiment each step of the signal generation in the 3He filled proportional counter was described using digital signal processing techniques (DSP). The electronic system has consisted of a detector, a preamplifier and a digital oscilloscope. The pulses from the detector were digitized using a OTSZS-02 (250USB)-4 digital storage oscilloscope from ZAO R UDNEV-SHILYAYEV . This oscilloscope allowed signal digitization with accuracy of 8 bit(256 levels) and with frequency of up to 5.10''8 samples/s. As a neutron source was used Cf-252.To obtain detector output current pulse I(t) created by the motions of the ions/electrons pairs was written an algorithm which can easily be programmed using modern computer programming languages

  3. Long-term plasticity is proportional to theta-activity.

    Directory of Open Access Journals (Sweden)

    Marian Tsanov

    Full Text Available BACKGROUND: Theta rhythm in the hippocampal formation is a main feature of exploratory behaviour and is believed to enable the encoding of new spatial information and the modification of synaptic weights. Cyclic changes of dentate gyrus excitability during theta rhythm are related to its function, but whether theta epochs per se are able to alter network properties of dentate gyrus for long time-periods is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: We used low-frequency stimulation protocols that amplify the power of endogenous theta oscillations, in order to estimate the plasticity effect of endogenous theta oscillations on a population level. We found that stimulation-induced augmentation of the theta rhythm is linked to a subsequent increase of neuronal excitability and decrease of the synaptic response. This EPSP-to-Spike uncoupling is related to an increased postsynaptic spiking on the positive phases of theta frequency oscillations. Parallel increase of the field EPSP slope and the population spike occurs only after concurrent pre- and postsynaptic activation. Furthermore, we observed that long-term potentiation (>24 h occurs in the dentate gyrus of freely behaving adult rats after phasic activity of entorhinal afferents in the theta-frequency range. This plasticity is proportional to the field bursting activity of granule cells during the stimulation, and may comprise a key step in spatial information transfer. Long-term potentiation of the synaptic component occurs only when the afferent stimulus precedes the evoked population burst, and is input-specific. CONCLUSIONS/SIGNIFICANCE: Our data confirm the role of the dentate gyrus in filtering information to the subsequent network during the activated state of the hippocampus.

  4. Remote Sensing of Ocean Color

    Science.gov (United States)

    Dierssen, Heidi M.; Randolph, Kaylan

    The oceans cover over 70% of the earth's surface and the life inhabiting the oceans play an important role in shaping the earth's climate. Phytoplankton, the microscopic organisms in the surface ocean, are responsible for half of the photosynthesis on the planet. These organisms at the base of the food web take up light and carbon dioxide and fix carbon into biological structures releasing oxygen. Estimating the amount of microscopic phytoplankton and their associated primary productivity over the vast expanses of the ocean is extremely challenging from ships. However, as phytoplankton take up light for photosynthesis, they change the color of the surface ocean from blue to green. Such shifts in ocean color can be measured from sensors placed high above the sea on satellites or aircraft and is called "ocean color remote sensing." In open ocean waters, the ocean color is predominantly driven by the phytoplankton concentration and ocean color remote sensing has been used to estimate the amount of chlorophyll a, the primary light-absorbing pigment in all phytoplankton. For the last few decades, satellite data have been used to estimate large-scale patterns of chlorophyll and to model primary productivity across the global ocean from daily to interannual timescales. Such global estimates of chlorophyll and primary productivity have been integrated into climate models and illustrate the important feedbacks between ocean life and global climate processes. In coastal and estuarine systems, ocean color is significantly influenced by other light-absorbing and light-scattering components besides phytoplankton. New approaches have been developed to evaluate the ocean color in relationship to colored dissolved organic matter, suspended sediments, and even to characterize the bathymetry and composition of the seafloor in optically shallow waters. Ocean color measurements are increasingly being used for environmental monitoring of harmful algal blooms, critical coastal habitats

  5. Ocean Fertilization for Sequestration of Carbon Dioxide from the Atmosphere

    Science.gov (United States)

    Boyd, Philip W.

    The ocean is a major sink for both preindustrial and anthropogenic carbon dioxide. Both physically and biogeochemically driven pumps, termed the solubility and biological pump, respectively Fig.5.1) are responsible for the majority of carbon sequestration in the ocean's interior [1]. The solubility pump relies on ocean circulation - specifically the impact of cooling of the upper ocean at high latitudes both enhances the solubility of carbon dioxide and the density of the waters which sink to great depth (the so-called deepwater formation) and thereby sequester carbon in the form of dissolved inorganic carbon (Fig.5.1). The biological pump is driven by the availability of preformed plant macronutrients such as nitrate or phosphate which are taken up by phytoplankton during photosynthetic carbon fixation. A small but significant proportion of this fixed carbon sinks into the ocean's interior in the form of settling particles, and in order to maintain equilibrium carbon dioxide from the atmosphere is transferred across the air-sea interface into the ocean (the so-called carbon drawdown) thereby decreasing atmospheric carbon dioxide (Fig.5.1).Fig.5.1

  6. Open ocean tide modelling

    Science.gov (United States)

    Parke, M. E.

    1978-01-01

    Two trends evident in global tidal modelling since the first GEOP conference in 1972 are described. The first centers on the incorporation of terms for ocean loading and gravitational self attraction into Laplace's tidal equations. The second centers on a better understanding of the problem of near resonant modelling and the need for realistic maps of tidal elevation for use by geodesists and geophysicists. Although new models still show significant differences, especially in the South Atlantic, there are significant similarities in many of the world's oceans. This allows suggestions to be made for future locations for bottom pressure gauge measurements. Where available, estimates of M2 tidal dissipation from the new models are significantly lower than estimates from previous models.

  7. To Build Proportions in Time, or Tie Knots in Space? A Reassessment of the Renaissance Turn in Architectural Proportions

    Directory of Open Access Journals (Sweden)

    Marvin Trachtenberg

    2014-06-01

    Full Text Available Since Alberti, and most critically since Wittkower’s 'Architectural Principles', architectural theory has tended to construe ‘proportions’ in plenary, static terms. The dimension of time and change that relentlessly affects all human endeavor is not accommodated by the celebrated Albertian ideal of immutable design perfection, so perfect in all respects that once attained ‘nothing can be added, taken away, or altered, but for the worse’. This article, drawing on the author’s recent book, 'Building-in-Time from Giotto to Alberti and Modern Oblivion' (Yale, 2010, outlines the antithetical, dynamic proportional methodology of the pre-Albertian architectural regime. Its point of departure was the author’s concept of durational aesthetics, according to which perfected architectural form is produced by a process of incessant revision. What distinguished this process from related ancient or neo-antique doctrines was above all its dynamic modality and participation in the fluid orientation and processes of ‘building-in-time’.

  8. On the Spot: Oceans

    OpenAIRE

    Male, Alan; Butterfield, Moira

    2000-01-01

    This a children's non-fiction, knowledge bearing picture book that is part of a Reader's Digest series called 'On the Spot'. The series deals with a range of topics related to the natural world and this one introduces its young audience to the ecosystems of the oceans. \\ud The publication was illustrated and designed by the author (Alan Male) and is technically described as a board book with interactive 'pop up' features, specifically conceived to engage children's discovery and learning thro...

  9. Islands in the Ocean

    Directory of Open Access Journals (Sweden)

    Elena Bagina

    2017-12-01

    Full Text Available Today’s China is an outpost of modern western architecture. All famous architects and firms build here. Having lost their historical context, the objects of traditional Chinese architecture become islands in the ocean of new development. Their destiny is controversial. Architectural masterpieces are perceived in a superficial manner not only by tourists, but also by local people. The link of times that used to be cherished in Chinese culture is being broken today.

  10. Ocean Bottom Seismic Scattering

    Science.gov (United States)

    1989-11-01

    EPR, the Clipperton and Orozco fracture zones , and along the coast of Mexico, were recorded for a two month period using ocean bottom seismometers...67. Tuthill, J.D., Lewis, B.R., and Garmany, J.D., 1981, Stonely waves, Lopez Island noise, and deep sea noise from I to 5 hz, Marine Geophysical...Patrol Pell Marine Science Library d/o Coast Guard R & D Center University of Rhode Island Avery Point Narragansett Bay Campus Groton, CT 06340

  11. Recent changes in the ventilation of the southern oceans.

    Science.gov (United States)

    Waugh, Darryn W; Primeau, Francois; Devries, Tim; Holzer, Mark

    2013-02-01

    Surface westerly winds in the Southern Hemisphere have intensified over the past few decades, primarily in response to the formation of the Antarctic ozone hole, and there is intense debate on the impact of this on the ocean's circulation and uptake and redistribution of atmospheric gases. We used measurements of chlorofluorocarbon-12 (CFC-12) made in the southern oceans in the early 1990s and mid- to late 2000s to examine changes in ocean ventilation. Our analysis of the CFC-12 data reveals a decrease in the age of subtropical subantarctic mode waters and an increase in the age of circumpolar deep waters, suggesting that the formation of the Antarctic ozone hole has caused large-scale coherent changes in the ventilation of the southern oceans.

  12. Ocean Observations of Climate Change

    Science.gov (United States)

    Chambers, Don

    2016-01-01

    The ocean influences climate by storing and transporting large amounts of heat, freshwater, and carbon, and exchanging these properties with the atmosphere. About 93% of the excess heat energy stored by the earth over the last 50 years is found in the ocean. More than three quarters of the total exchange of water between the atmosphere and the earth's surface through evaporation and precipitation takes place over the oceans. The ocean contains 50 times more carbon than the atmosphere and is at present acting to slow the rate of climate change by absorbing one quarter of human emissions of carbon dioxide from fossil fuel burning, cement production, deforestation and other land use change.Here I summarize the observational evidence of change in the ocean, with an emphasis on basin- and global-scale changes relevant to climate. These include: changes in subsurface ocean temperature and heat content, evidence for regional changes in ocean salinity and their link to changes in evaporation and precipitation over the oceans, evidence of variability and change of ocean current patterns relevant to climate, observations of sea level change and predictions over the next century, and biogeochemical changes in the ocean, including ocean acidification.

  13. Springer handbook of ocean engineering

    CERN Document Server

    Xiros, Nikolaos

    2016-01-01

    The handbook is the definitive reference for the interdisciplinary field that is ocean engineering. It integrates the coverage of fundamental and applied material and encompasses a diverse spectrum of systems, concepts and operations in the maritime environment, as well as providing a comprehensive update on contemporary, leading-edge ocean technologies. Coverage includes but is not limited to; an overview of ocean science, ocean signals and instrumentation, coastal structures, developments in ocean energy technologies, and ocean vehicles and automation. The handbook will be of interest to practitioners in a range of offshore industries and naval establishments as well as academic researchers and graduate students in ocean, coastal, offshore, and marine engineering and naval architecture.

  14. Ocean circulation generated magnetic signals

    DEFF Research Database (Denmark)

    Manoj, C.; Kuvshinov, A.; Maus, S.

    2006-01-01

    Conducting ocean water, as it flows through the Earth's magnetic field, generates secondary electric and magnetic fields. An assessment of the ocean-generated magnetic fields and their detectability may be of importance for geomagnetism and oceanography. Motivated by the clear identification...... of ocean tidal signatures in the CHAMP magnetic field data we estimate the ocean magnetic signals of steady flow using a global 3-D EM numerical solution. The required velocity data are from the ECCO ocean circulation experiment and alternatively from the OCCAM model for higher resolution. We assume...... of the magnetic field, as compared to the ECCO simulation. Besides the expected signatures of the global circulation patterns, we find significant seasonal variability of ocean magnetic signals in the Indian and Western Pacific Oceans. Compared to seasonal variation, interannual variations produce weaker signals....

  15. Polar oceans in a changing climate.

    Science.gov (United States)

    Barnes, David K A; Tarling, Geraint A

    2017-06-05

    Most of Earth's surface is blue or white, but how much of each would depend on the time of observation. Our planet has been through phases of snowball (all frozen), greenhouse (all liquid seas) and icehouse (frozen and liquid). Even during current icehouse conditions, the extent of ice versus water has changed considerably between ice ages and interglacial periods. Water has been vital for life on Earth and has driven and been influenced by transitions between greenhouse and icehouse. However, neither the possession of water nor having liquid and frozen seas are unique to Earth (Figure 1). Frozen water oceans on the moons Enceladus and Europa (and possibly others) and the liquid and frozen hydrocarbon oceans on Titan probably represent the most likely areas to find extraterrestrial life. We know very little about life in Earth's polar oceans, yet they are the engine of the thermohaline 'conveyor-belt', driving global circulation of heat, oxygen, carbon and nutrients as well as setting sea level through change in ice-mass balance. In regions of polar seas, where surface water is particularly cold and dense, it sinks to generate a tropic-ward flow on the ocean floor of the Pacific, Atlantic and Indian Oceans. Cold water holds more gas, so this sinking water exports O 2 and nutrients, thereby supporting life in the deep sea, as well as soaking up CO 2 from the atmosphere. Water from mid-depths at lower latitudes flows in to replace the sinking polar surface water. This brings heat. The poles are cold because they receive the least energy from the sun, and this extreme light climate varies on many different time scales. To us, the current warm, interglacial conditions seem normal, yet such phases have represented only ∼10% of Homo sapiens' existence. Variations in Earth's orbit (so called 'Milankovitch cycles') have driven cyclical alternation of glaciations (ice ages) and warmer interglacials. Despite this, Earth's polar regions have been our planet's most

  16. Aplikasi Kontrol PI (Proportional Integral pada Katup Ekspansi Mesin Pendingin

    Directory of Open Access Journals (Sweden)

    Bayu Rudiyanto

    2016-10-01

    Full Text Available Abstrak. Penelitian ini bertujuan untuk melakukan proses perancangan dan pembuatan kontrol katup ekspansi otomatis dengan menggunakan sistem kontrol PI, untuk melakukan proses pengontrolan temperatur ruang evaporator agar didapatkan hasil pembekuan yang lebih optimal. Sensor temperatur LM35 digunakan dalam penelitian ini untuk melakukan pembacaan temperatur pada ruang evaporator, yang mana dari hasil pembacaan sensor tersebut digunakan sebagai sinyal masukan untuk sistem kontrol PI. Berdasarkan hasil pengujian sensor LM35 mempunyai sensitivitas pembacaan sebesar 0,009335 V/oC.  Unjuk kerja sistem kontrol PI pada penelitian ini didapatkan respon yang baik pada nilai Kp = 20 dan Ki = 10, dimana dengan nilai berikut untuk mencapai temperatur set point waktu yang dibutuhkan selama 251 detik dengan nilai maximum overshoot lebih rendah yaitu -2,4 oC. Hasil pendinginan yang didapatkan pada penelitian ini dengan menggunakan sistem kontrol katup ekspansi otomatis didapat proses pendinginan yang lebih cepat dan energi yang dibutuhkan jauh lebih hemat yaitu sebesar 0,265 kWh.   The Application of A Control PI (Proportional Integral on Expansion Valves Refrigeration Machine  Abstract. This research aim to do design process and making control valve expansion automatic by using control system PI, which then applied on refrigerator plates touch to perform the process of control freezing temperatures. Censor temperature LM35 used in this research to do reading the temperature at evaporator room, of results reading sensors is used as input signal to control system PI. Based on the test result of testing censor LM35 have the sensitivity reading of almost accordance with the datav sheet is as much as 0,009335 V/oC. Were control sistem works PI the research this obtained response good to value center Kp = 20 and Ki =10. In which value, to reach set temperature point , the time it takes 251 seconds by value maximum overshoot point lower then -2.4°C. The result

  17. Transferring and implementing the general dynamic model of oceanic island biogeography at the scale of island fragments: the role of geological age and topography in plant diversification in the Canaries

    DEFF Research Database (Denmark)

    Otto, Rüdiger; Whittaker, Robert J.; von Gaisberg, Markus

    2016-01-01

    ontogenies, featuring surfaces of varying age. Here, we extend the GDM to apply at a local scale within islands, and test the predictions analytically within individual islands. Location El Hierro, La Palma and Tenerife (Canary Islands). Methods Following the GDM logic, we derive predictions...

  18. Experimental study on mix proportion of fiber reinforced cementitious composites

    Science.gov (United States)

    Jia, Yi; Zhao, Renda; Liao, Ping; Li, Fuhai; Yuan, Yuan; Zhou, Shuang

    2017-10-01

    To study the mechanical property of fiber reinforced cementations composites influenced by the fiber length, quartz sand diameter, matrix of water cement ratio, volume fraction of fiber and magnesium acrylate solution. Several 40×40×160 mm standard test specimens, "8" specimens and long "8" specimens and 21 groups of fiber concrete specimens were fabricated. The flexural, compressive and uniaxial tensile strength were tested by using the bending resistance, compression resistance and electronic universal testing machine. The results show that flexural and compressive strength of fiber reinforced cementations composites increases along with the increase of quartz sand diameter, with the growth of the PVA fiber length increases; When the water-binder ratio is 0.25 and powder-binder ratio is 0.3, the PVA fiber content is 1.5% of the mass of cementations materials, there is a phenomenon of strain hardening; The addition of magnesium acrylate solution reduces the tensile strength of PVA fiber reinforced cementations composites, the tensile strength of the specimens in the curing age of 7d is decreased by about 21% and the specimens in curing age of 28d is decreased by more than 50%.

  19. Implementasi Strategi Blue Ocean Untuk Mencapai Kinerja Perusahaan Yang Kompetitif

    OpenAIRE

    Chadhiq, Umar

    2009-01-01

    Since the dawn of the industrial age, companies have engaged in head-to-head competition. They are using red ocean strategy and have fought for competitive advantage, battled over market share, and struggled for differentiation. Now imagine instead the prospects for growth if companies could operate with no competitors at all. Because they operate blue ocean strategy, and they are will create uncontested performance.

  20. Juvenile wood volume and its proportion to stem volume vs. selected biometric features of Scots pine (Pinus sylvestris L. trees

    Directory of Open Access Journals (Sweden)

    Arkadiusz Tomczak

    2011-01-01

    Full Text Available The aim of the study was to determine whether there is a correlation between breast height diameter, tree height and stem total volume of Scots pines, on the one hand, and volume and proportion of juvenile wood, on the other. The investigations comprised pure pine stands of the IInd, IIIrd, IVth and Vth age classes developed in conditions of fresh mixed coniferous forest. A distinct curvilinear correlation was found between volume and proportion of juvenile wood in tree stems and breast height diameter, height and stem total volume. Because of high values of determination coefficients (R2, which characterised the above-mentioned correlations, it seems appropriate to use these regularities to assess the quality of the timber raw material regarding the proportions of its volume and juvenile wood in stems of Scots pine trees.

  1. Lifetime of an ocean island volcano feeder zone: constraints from U-Pb dating on coexisting zircon and baddeleyite, and 40/39Ar age determinations, Fuerteventura, Canary Islands

    Science.gov (United States)

    Allibon, James; Ovtcharova, Maria; Bussy, Francois; Cosca, Michael; Schaltegger, Urs; Bussien, Denise; Lewin, Eric

    2011-01-01

    High-precision isotope dilution - thermal ionization mass spectrometry (ID-TIMS) U-Pb zircon and baddeleyite ages from the PX1 vertically layered mafic intrusion Fuerteventura, Canary Islands, indicate initiation of magma crystallization at 22.10 ± 0.07 Ma. The magmatic activity lasted a minimum of 0.52 Ma. 40Ar/39Ar amphibole dating yielded ages from 21.9 ± 0.6 to 21.8 ± 0.3, identical within errors to the U-Pb ages, despite the expected 1% theoretical bias between 40Ar/39Ar and U-Pb dates. This overlap could result from (i) rapid cooling of the intrusion (i.e., less than the 0.3 to 0.6 Ma 40Ar/39Ar age uncertainties) from closure temperatures (Tc) of zircon (699-988 °C) to amphibole (500-600 °C); (ii) lead loss affecting the youngest zircons; or (iii) excess argon shifting the plateau ages towards older values. The combination of the 40Ar/39Ar and U/Pb datasets implies that the maximum amount of time PX1 intrusion took to cool below amphibole Tc is 0.8 Ma, suggesting PX1 lifetime of 520,000 to 800,000 Ma. Age disparities among coexisting baddeleyite and zircon (22.10 ± 0.07/0.08/0.15 Ma and 21.58 ± 0.15/0.16/0.31 Ma) in a gabbro sample from the pluton margin suggest complex genetic relationships between phases. Baddeleyite is found preserved in plagioclase cores and crystallized early from low silica activity magma. Zircon crystallized later in a higher silica activity environment and is found in secondary scapolite and is found close to calcite veins, in secondary scapolite that recrystallised from plagioclase. close to calcite veins. Oxygen isotope δ18O values of altered plagioclase are high (+7.7), indicating interaction with fluids derived from host-rock carbonatites. The coexistence of baddeleyite and zircon is ascribed to interaction of the PX1 gabbro with CO2-rich carbonatite-derived fluids released during contact metamorphism.

  2. An Analysis of Maxillary Anterior Teeth Dimensions for the Existence of Golden Proportion: Clinical Study.

    Science.gov (United States)

    Sandeep, Nalla; Satwalekar, Parth; Srinivas, Siva; Reddy, Chandra Sekhar; Reddy, G Ramaswamy; Reddy, B Anantha

    2015-09-01

    Appearance of the face is a great concern to everyone, as it is a significant part of self-image. The study analyzed the clinical crown dimensions of the maxillary anterior teeth with respect to their apparent mesiodistal widths, width-to-height ratio to determine whether golden proportion existed among the South Indian population. A total of 240 dentulous subjects were chosen for the study (120 males and 120 females) age ranging between 18 and 28 years. Full face and anterior teeth images of the subjects were made on specially designed device resembling a face-bow, mounted onto the wall under a standard light source. The width and height of the maxillary central incisors were measured on the stone casts using a digital caliper. The mean perceived maxillary lateral incisor to central incisor width ratio was 0.67 in males and 0.703 in females. The mean perceived maxillary canine to lateral incisor width ratio was 0.744 in males and 0.714 in females. The mean width-to-height ratio of the maxillary central incisor was 79.49% in males and 79.197% in females. The golden proportion was not found between perceived mesiodistal widths of maxillary central and lateral incisors and nor between perceived mesiodistal widths of maxillary lateral incisors and canines. In the majority of subjects, the width-to-height ratio of maxillary central incisor was within 75-80%. There are no statistically significant differences in maxillary anterior teeth proportions between males and females. The results may serve as guidelines for treatment planning in restorative dentistry and periodontal surgery.

  3. Regulation, proportionality and discharges of radioactive wastes: UK perspective

    International Nuclear Information System (INIS)

    Morley, Bob; Butler, Gregg; Mc Glynn, Grace

    2008-01-01

    In recent years, the UK Government and the Regulators have made a commitment to further improve the operation of the regulatory regime and to its operating within the principles of proportionality, transparency, consistency and accountability which underpin the Government's approach to regulation in general. Particular emphasis was to be placed upon ensuring that there is greater consistency in the treatment of risk and hazard; proportionate and cost effective delivery of public, worker and environmental protection; and an open and transparently applied regulatory system. It is noteworthy that with regard to radiation protection, there are different limits for public doses and workforce doses, with the latter 15 times greater. Allowable doses for medical patients are higher still. This discrepancy raises a question in itself. This presentation focuses on the practical application of the regulatory regime with particular regard to environmental discharges and disposals. Under the Radioactive Substances Act 1993, Operators within the UK nuclear industry are required to employ Best Practicable Means (BPM) to control and minimise radioactive discharges to ensure that doses from discharges are As Low As Reasonably Achievable (ALARA). Scientific assessments to date indicate that there are no expectations of environmental harm from discharges at Sellafield (and hence likewise at other UK nuclear sites where the discharges are lower), even where those discharges have historically been up to two orders of magnitude higher than current levels. Current discharges result in doses which are a small fraction of those received by the UK population due to natural background radiation. In addition, there is no proven environmental harm from foreseeable future discharges from Sellafield or other UK nuclear sites. This is supported by independent work which illustrates that the public collective dose from Sellafield discharges is almost all delivered at risks of less that one in a

  4. Absolute and proportional measures of potential markers of rehearsal, and their implications for accounts of its development

    Science.gov (United States)

    Jarrold, Christopher; Danielsson, Henrik; Wang, Xiaoli

    2015-01-01

    Previous studies of the development of phonological similarity and word length effects in children have shown that these effects are small or absent in young children, particularly when measured using visual presentation of the memoranda. This has often been taken as support for the view that young children do not rehearse. The current paper builds on recent evidence that instead suggests that absent phonological similarity and word length effects in young children reflects the same proportional cost of these effects in children of all ages. Our aims are to explore the conditions under which this proportional scaling account can reproduce existing developmental data, and in turn suggest ways that future studies might measure and model phonological similarity and word length effects in children. To that end, we first fit a single mathematical function through previously reported data that simultaneously captures absent and negative proportional effects of phonological similarity in young children plus constant proportional similarity effects in older children. This developmental function therefore provides the benchmark that we seek to re-produce in a series of subsequent simulations that test the proportional scaling account. These simulations reproduce the developmental function well, provided that they take into account the influence of floor effects and of measurement error. Our simulations suggest that future empirical studies examining these effects in the context of the development of rehearsal need to take into account proportional scaling. They also provide a demonstration of how proportional costs can be explored, and of the possible developmental functions associated with such an analysis. PMID:25852615

  5. Effects of age, adipose percent, and reproduction on PCB concentrations and profiles in an extreme fasting North Pacific marine mammal.

    Directory of Open Access Journals (Sweden)

    Sarah H Peterson

    Full Text Available Persistent organic pollutants, including polychlorinated biphenyls (PCBs, are widely distributed and detectable far from anthropogenic sources. Northern elephant seals (Mirounga angustirostris biannually travel thousands of kilometers to forage in coastal and open-ocean regions of the northeast Pacific Ocean and then return to land where they fast while breeding and molting. Our study examined potential effects of age, adipose percent, and the difference between the breeding and molting fasts on PCB concentrations and congener profiles in blubber and serum of northern elephant seal females. Between 2005 and 2007, we sampled blubber and blood from 58 seals before and after a foraging trip, which were then analyzed for PCBs. Age did not significantly affect total PCB concentrations; however, the proportion of PCB congeners with different numbers of chlorine atoms was significantly affected by age, especially in the outer blubber. Younger adult females had a significantly greater proportion of low-chlorinated PCBs (tri-, tetra-, and penta-CBs than older females, with the opposite trend observed for hepta-CBs, indicating that an age-associated process such as parity (birth may significantly affect congener profiles. The percent of adipose tissue had a significant relationship with inner blubber PCB concentrations, with the highest mean concentrations observed at the end of the molting fast. These results highlight the importance of sampling across the entire blubber layer when assessing contaminant levels in phocid seals and taking into account the adipose stores and reproductive status of an animal when conducting contaminant research.

  6. Assessment of divine proportion in the cranial structure of individuals with Angle Class II malocclusion on lateral cephalograms

    Directory of Open Access Journals (Sweden)

    Marcos André dos Santos da Silva

    2012-06-01

    Full Text Available INTRODUCTION: The study of the Divine Proportion (Φ = 1.618 began with the Greeks, having as main researchers the mathematician Pythagoras and the sculptor Phidias. In Dentistry, Ricketts (1981-82 was an early to study this issue. OBJECTIVE: This study proposed to evaluate how some cephalometric measures are presented in relation to the Divine Proportion, with the total of 52 proportions, formed by 28 cephalometric landmarks. METHODS: Lateral cephalograms of 40 Class II adults patients aging from 17 to 45 years (13 male and 27 female were evaluated. The linear distances between the landmarks were measured using Radiocef Studio software. RESULTS: After statistical analysis, the data shown an average of 65,48% in the Divine Proportion, 17,5% in the relation Ans-Op/V1S-DM16 and 97,5% in the relations Na-Me/Na-PoNa e Na-PoNa/Na-Gn. CONCLUSION: Among all cephalometric measurements investigated, the lower facial third and the dental arches showed the smallest percentages of Divine Proportion.

  7. Substantial proportion of MODY among multiplex families participating in a Type 1 diabetes prediction programme.

    Science.gov (United States)

    Petruzelkova, L; Dusatkova, P; Cinek, O; Sumnik, Z; Pruhova, S; Hradsky, O; Vcelakova, J; Lebl, J; Kolouskova, S

    2016-12-01

    Patients with maturity-onset diabetes of the young (MODY) might be over-represented in families with histories of Type 1 diabetes. Our aim was to re-evaluate families participating in the Czech T1D Prediction Programme (PREDIA.CZ) with at least two members affected with diabetes to assess the proportion of MODY among these families and determine its most significant clinical predictors. Of the 557 families followed up by the PREDIA.CZ, 53 (9.5%) had two or more family members with diabetes. One proband with diabetes from these families was chosen for direct sequencing of the GCK, HNF1A, HNF4A and INS genes. Non-parametric tests and a linear logistic regression model were used to evaluate differences between MODY and non-MODY families. MODY was genetically diagnosed in 24 of the 53 families with multiple occurrences of diabetes (45%). Mutations were detected most frequently in GCK (58%), followed by HNF1A (38%) and INS (4%). MODY families were more likely to have a parent with diabetes and had a higher proportion of females with diabetes than non-MODY families. Higher age (P MODY families already presenting with diabetes. A prediction programme for Type 1 diabetes would provide a useful new source of patients with MODY most likely to benefit from an accurate diagnosis. This identification has implications for patient treatment and disease prognosis. © 2015 Diabetes UK.

  8. Ocean Tide Loading Computation

    Science.gov (United States)

    Agnew, Duncan Carr

    2005-01-01

    September 15,2003 through May 15,2005 This grant funds the maintenance, updating, and distribution of programs for computing ocean tide loading, to enable the corrections for such loading to be more widely applied in space- geodetic and gravity measurements. These programs, developed under funding from the CDP and DOSE programs, incorporate the most recent global tidal models developed from Topex/Poscidon data, and also local tide models for regions around North America; the design of the algorithm and software makes it straightforward to combine local and global models.

  9. Ocean wave energy conversion

    CERN Document Server

    McCormick, Michael E

    2007-01-01

    This volume will prove of vital interest to those studying the use of renewable resources. Scientists, engineers, and inventors will find it a valuable review of ocean wave mechanics as well as an introduction to wave energy conversion. It presents physical and mathematical descriptions of the nine generic wave energy conversion techniques, along with their uses and performance characteristics.Author Michael E. McCormick is the Corbin A. McNeill Professor of Naval Engineering at the U.S. Naval Academy. In addition to his timely and significant coverage of possible environmental effects associa

  10. On Some Aspects of Study on Dimensions and Proportions of Church Architecture

    Science.gov (United States)

    Kolobaeva, T. V.

    2017-11-01

    Architecture forms and arranges the environment required for a comfortable life and human activity. The modern principles of architectural space arrangement and form making are represented by a reliable system of buildings which are used in design. Architects apply these principles and knowledge of space arrangement in regard to the study of special and regulatory literature when performing a particular creative task. This system of accumulated knowledge is perceived in the form of an existing stereotype with no regard for understanding of the form making and experience inherent to the architects and thinkers of previous ages. We make an attempt to restore this connection as the form-making specific regularities known by ancient architects should be taken into account. The paper gives an insight into some aspects of traditional dimensions and proportions of church architecture.

  11. Oceanic magmatic evolution during ocean opening under influence of mantle plume

    Science.gov (United States)

    Sushchevskaya, Nadezhda; Melanholina, Elena; Belyatsky, Boris; Krymsky, Robert; Migdisova, Natalya

    2015-04-01

    Petrology, geochemistry and geophysics as well as numerical simulation of spreading processes in plume impact environments on examples of Atlantic Ocean Iceland and the Central Atlantic plumes and Kerguelen plume in the Indian Ocean reveal: - under interaction of large plume and continental landmass the plume can contribute to splitting off individual lithosphere blocks, and their subsequent movement into the emergent ocean. At the same time enriched plume components often have geochemical characteristics of the intact continental lithosphere by early plume exposure. This is typical for trap magmatism in Antarctica, and for magmatism of North and Central Atlantic margins; - in the course of the geodynamic reconstruction under the whole region of the South Atlantic was formed (not in one step) metasomatized enriched sub-oceanic mantle with pyroxenite mantle geochemical characteristics and isotopic composition of enriched HIMU and EM-2 sources. That is typical for most of the islands in the West Antarctic. This mantle through spreading axes jumping involved in different proportions in the melting under the influence of higher-temperature rising asthenospheric lherzolite mantle; - CAP activity was brief enough (200 ± 2 Ma), but Karoo-Maud plume worked for a longer time and continued from 180 to 170 Ma ago in the main phase. Plume impact within Antarctica distributed to the South and to the East, leading to the formation of extended igneous provinces along the Transantarctic Mountains and along the east coast (Queen Maud Land province and Schirmacher Oasis). Moreover, this plume activity may be continued later on, after about 40 million years cessation, as Kerguelen plume within the newly-formed Indian Ocean, significantly affects the nature of the rift magmatism; - a large extended uplift in the eastern part of the Indian Ocean - Southeastern Indian Ridge (SEIR) was formed on the ancient spreading Wharton ridge near active Kerguelen plume. The strongest plume

  12. Postnatal ontogeny of limb proportions and functional indices in the subterranean rodent Ctenomys talarum (Rodentia: Ctenomyidae).

    Science.gov (United States)

    Echeverría, Alejandra Isabel; Becerra, Federico; Vassallo, Aldo Iván

    2014-08-01

    Burrow construction in the subterranean Ctenomys talarum (Rodentia: Ctenomyidae) primarily occurs by scratch-digging. In this study, we compared the limbs of an ontogenetic series of C. talarum to identify variation in bony elements related to fossorial habits using a morphometrical and biomechanical approach. Diameters and functional lengths of long bones were measured and 10 functional indices were constructed. We found that limb proportions of C. talarum undergo significant changes throughout postnatal ontogeny, and no significant differences between sexes were observed. Five of six forelimb indices and two of four hindlimb indices showed differences between ages. According to discriminant analysis, the indices that contributed most to discrimination among age groups were robustness of the humerus and ulna, relative epicondylar width, crural and brachial indices, and index of fossorial ability (IFA). Particularly, pups could be differentiated from juveniles and adults by more robust humeri and ulnae, wider epicondyles, longer middle limb elements, and a proportionally shorter olecranon. Greater robustness indicated a possible compensation for lower bone stiffness while wider epicondyles may be associated to improved effective forces in those muscles that originate onto them, compensating the lower muscular development. The gradual increase in the IFA suggested a gradual enhancement in the scratch-digging performance due to an improvement in the mechanical advantage of forearm extensors. Middle limb indices were higher in pups than in juveniles-adults, reflecting relatively more gracile limbs in their middle segments, which is in accordance with their incipient fossorial ability. In sum, our results show that in C. talarum some scratch-digging adaptations are already present during early postnatal ontogeny, which suggests that they are prenatally shaped, and other traits develop progressively. The role of early digging behavior as a factor influencing on

  13. Proportional chambers and multiwire drift chambers at high rates

    International Nuclear Information System (INIS)

    Walenta, A.H.

    1977-01-01

    The high event and particle rates expected for ISABELLE intersecting storage rings raise the question whether PWC's and drift chambers, now widely in use in experiments, still can operate under such conditions. Various effects depend on the number of avalanches produced per length of wire N and the size of the avalanche Q, i.e., on the number of positive ions created in an avalanche. Therefore the important parameter for the following discussion is the product QN. The minimum Q is determined by the type and noise level of preamplifiers used. Examples are given for a typical low noise amplifier as well as for a typical integrated ''cheap'' amplifier. The rate/wire length N depends on the chamber arrangement, wire spacing, etc. In multiwire drift chambers, a single wire shows space-charge effects reducing the pulse height by 1% at a rate of N = 7 x 10 3 mm -1 sec -1 . At a rate of N approximately equal to 10 5 mm -1 sec -1 an efficiency loss of the order of 1% was noticed. The aging effect due to deposits on the anode wire can be reduced using low noise amplifiers and low gas gain to such an extent that a lifetime of about half a year at ISABELLE can be expected. The use of conventional cheap preamplifiers will result in a typical lifetime of about 30 days. Improvements are probable. The time resolution of Δt/sub r/ = 4 nsec fwhm seems adequate for event rates of 10 7 sec -1 . The memory time Δt/sub m/ greater than or equal to 100 nsec may cause serious problems for pattern recognition depending on layout and readout. The use of induced signals on cathode pads, thus reading out shorter parts of the wire, can solve the problem

  14. Monitoring of ocean storage projects

    Energy Technology Data Exchange (ETDEWEB)

    Caldeira, K. [Energy and Environment Directorate, Lawrence Livermore National Laboratory, Livermore, CA (United States)

    2003-02-01

    It has been proposed that atmospheric CO2 accumulation could be slowed by capture of CO2 from point sources and subsequent storage of that CO2 in the ocean. If applied, such sequestration efforts would need to be monitored for compliance, effectiveness, and unintended consequences. Aboveground inspection and monitoring of facilities and practices, combined with ocean observations, could assure compliance with ocean sequestration guidelines and regulations. Ocean observations could be made using a variety of sensors mounted on moorings or underwater gliders. Long-term effectiveness and leakage to the atmosphere must be estimated from models, since on large spatial scales it will be impossible to observationally distinguish carbon stored by a project from variable concentrations of background carbon. Furthermore, the ocean naturally would absorb roughly 80% of fossil fuel CO2 released to the atmosphere within a millennium. This means that most of the CO2 sequestered in the ocean that leaks out to the atmosphere will be reabsorbed by the ocean. However, there is no observational way to distinguish remaining carbon from reabsorbed carbon. The science of monitoring unintended consequences in the deep ocean interior is at a primitive state. Little is understood about ecosystems of the deep ocean interior; and even less is understood about how those ecosystems would respond to added CO2. High priority research objectives should be (1) to improve our understanding of the natural ecosystems of the deep ocean, and (2) to improve our understanding of the response of these ecosystems to increased oceanic CO2 concentrations and decreased ocean pH.

  15. Paleomagnetism continents and oceans

    CERN Document Server

    McElhinny, Michael W; Dmowska, Renata; Holton, James R; Rossby, H Thomas

    1999-01-01

    Paleomagnetism is the study of the fossil magnetism in rocks. It has been paramount in determining that the continents have drifted over the surface of the Earth throughout geological time. The fossil magnetism preserved in the ocean floor has demonstrated how continental drift takes place through the process of sea-floor spreading. The methods and techniques used in paleomagnetic studies of continental rocks and of the ocean floor are described and then applied to determining horizontal movements of the Earth''s crust over geological time. An up-to-date review of global paleomagnetic data enables 1000 millionyears of Earth history to be summarized in terms of the drift of the major crustal blocks over the surface of the Earth. The first edition of McElhinny''s book was heralded as a "classic and definitive text." It thoroughly discussed the theory of geomagnetism, the geologicreversals of the Earth''s magnetic field, and the shifting of magnetic poles. In the 25 years since the highly successful first editio...

  16. Blue ocean leadership.

    Science.gov (United States)

    Kim, W Chan; Mauborgne, Renée

    2014-05-01

    Ten years ago, two INSEAD professors broke ground by introducing "blue ocean strategy," a new model for discovering uncontested markets that are ripe for growth. In this article, they apply their concepts and tools to what is perhaps the greatest challenge of leadership: closing the gulf between the potential and the realized talent and energy of employees. Research indicates that this gulf is vast: According to Gallup, 70% of workers are disengaged from their jobs. If companies could find a way to convert them into engaged employees, the results could be transformative. The trouble is, managers lack a clear understanding of what changes they could make to bring out the best in everyone. Here, Kim and Mauborgne offer a solution to that problem: a systematic approach to uncovering, at each level of the organization, which leadership acts and activities will inspire employees to give their all, and a process for getting managers throughout the company to start doing them. Blue ocean leadership works because the managers' "customers"-that is, the people managers oversee and report to-are involved in identifying what's effective and what isn't. Moreover, the approach doesn't require leaders to alter who they are, just to undertake a different set of tasks. And that kind of change is much easier to implement and track than changes to values and mind-sets.

  17. Ocean bottom seismometer technology

    Science.gov (United States)

    Prothero, William A., Jr.

    Seismometers have been placed on the ocean bottom for about 45 years, beginning with the work of Ewing and Vine [1938], and their current use to measure signals from earthquakes and explosions constitutes an important research method for seismological studies. Approximately 20 research groups are active in the United Kingdom, France, West Germany, Japan, Canada, and the United States. A review of ocean bottom seismometer (OBS) instrument characteristics and OBS scientific studies may be found in Whitmarsh and Lilwall [1984]. OBS instrumentation is also important for land seismology. The recording systems that have been developed have been generally more sophisticated than those available for land use, and several modern land seismic recording systems are based on OBS recording system designs.The instrumentation developed for OBS work was the topic of a meeting held at the University of California, Santa Barbara, in July 1982. This article will discuss the state of the art of OBS Technology, some of the problems remaining to be solved, and some of the solutions proposed and implemented by OBS scientists and engineers. It is not intended as a comprehensive review of existing instrumentation.

  18. Ocean Thermal Extractable Energy Visualization

    Energy Technology Data Exchange (ETDEWEB)

    Ascari, Matthew [Lockheed Martin Corporation, Bethesda, MD (United States)

    2012-10-28

    The Ocean Thermal Extractable Energy Visualization (OTEEV) project focuses on assessing the Maximum Practicably Extractable Energy (MPEE) from the world’s ocean thermal resources. MPEE is defined as being sustainable and technically feasible, given today’s state-of-the-art ocean energy technology. Under this project the OTEEV team developed a comprehensive Geospatial Information System (GIS) dataset and software tool, and used the tool to provide a meaningful assessment of MPEE from the global and domestic U.S. ocean thermal resources.

  19. The ocean circulation inverse problem

    National Research Council Canada - National Science Library

    Wunsch, C

    1996-01-01

    .... This book addresses the problem of inferring the state of the ocean circulation, understanding it dynamically, and even forecasting it through a quantitative combination of theory and observation...

  20. Global equivalent magnetization of the oceanic lithosphere

    Science.gov (United States)

    Dyment, J.; Choi, Y.; Hamoudi, M.; Lesur, V.; Thebault, E.

    2015-11-01

    As a by-product of the construction of a new World Digital Magnetic Anomaly Map over oceanic areas, we use an original approach based on the global forward modeling of seafloor spreading magnetic anomalies and their comparison to the available marine magnetic data to derive the first map of the equivalent magnetization over the World's ocean. This map reveals consistent patterns related to the age of the oceanic lithosphere, the spreading rate at which it was formed, and the presence of mantle thermal anomalies which affects seafloor spreading and the resulting lithosphere. As for the age, the equivalent magnetization decreases significantly during the first 10-15 Myr after its formation, probably due to the alteration of crustal magnetic minerals under pervasive hydrothermal alteration, then increases regularly between 20 and 70 Ma, reflecting variations in the field strength or source effects such as the acquisition of a secondary magnetization. As for the spreading rate, the equivalent magnetization is twice as strong in areas formed at fast rate than in those formed at slow rate, with a threshold at ∼40 km/Myr, in agreement with an independent global analysis of the amplitude of Anomaly 25. This result, combined with those from the study of the anomalous skewness of marine magnetic anomalies, allows building a unified model for the magnetic structure of normal oceanic lithosphere as a function of spreading rate. Finally, specific areas affected by thermal mantle anomalies at the time of their formation exhibit peculiar equivalent magnetization signatures, such as the cold Australian-Antarctic Discordance, marked by a lower magnetization, and several hotspots, marked by a high magnetization.

  1. Depth Dependent Relationships between Temperature and Ocean Heterotrophic Prokaryotic Production

    KAUST Repository

    Lønborg, Christian

    2016-06-07

    Marine prokaryotes play a key role in cycling of organic matter and nutrients in the ocean. Using a unique dataset (>14,500 samples), we applied a space-for-time substitution analysis to assess the temperature dependence of prokaryotic heterotrophic production (PHP) in epi- (0-200 m), meso- (201-1000 m) and bathypelagic waters (1001-4000 m) of the global ocean. Here, we show that the temperature dependence of PHP is fundamentally different between these major oceanic depth layers, with an estimated ecosystem-level activation energy (E) of 36 ± 7 kJ mol for the epipelagic, 72 ± 15 kJ mol for the mesopelagic and 274 ± 65 kJ mol for the bathypelagic realm. We suggest that the increasing temperature dependence with depth is related to the parallel vertical gradient in the proportion of recalcitrant organic compounds. These Ea predict an increased PHP of about 5, 12, and 55% in the epi-, meso-, and bathypelagic ocean, respectively, in response to a water temperature increase by 1°C. Hence, there is indication that a major thus far underestimated feedback mechanism exists between future bathypelagic ocean warming and heterotrophic prokaryotic activity.

  2. Individual and population-level responses to ocean acidification.

    Science.gov (United States)

    Harvey, Ben P; McKeown, Niall J; Rastrick, Samuel P S; Bertolini, Camilla; Foggo, Andy; Graham, Helen; Hall-Spencer, Jason M; Milazzo, Marco; Shaw, Paul W; Small, Daniel P; Moore, Pippa J

    2016-01-29

    Ocean acidification is predicted to have detrimental effects on many marine organisms and ecological processes. Despite growing evidence for direct impacts on specific species, few studies have simultaneously considered the effects of ocean acidification on individuals (e.g. consequences for energy budgets and resource partitioning) and population level demographic processes. Here we show that ocean acidification increases energetic demands on gastropods resulting in altered energy allocation, i.e. reduced shell size but increased body mass. When scaled up to the population level, long-term exposure to ocean acidification altered population demography, with evidence of a reduction in the proportion of females in the population and genetic signatures of increased variance in reproductive success among individuals. Such increased variance enhances levels of short-term genetic drift which is predicted to inhibit adaptation. Our study indicates that even against a background of high gene flow, ocean acidification is driving individual- and population-level changes that will impact eco-evolutionary trajectories.

  3. Depth Dependent Relationships between Temperature and Ocean Heterotrophic Prokaryotic Production

    KAUST Repository

    Lø nborg, Christian; Cuevas, L. Antonio; Reinthaler, Thomas; Herndl, Gerhard J.; Gasol, Josep M.; Moran, Xose Anxelu G.; Bates, Nicholas R.; á lvarez-Salgado, Xosé A.

    2016-01-01

    Marine prokaryotes play a key role in cycling of organic matter and nutrients in the ocean. Using a unique dataset (>14,500 samples), we applied a space-for-time substitution analysis to assess the temperature dependence of prokaryotic heterotrophic production (PHP) in epi- (0-200 m), meso- (201-1000 m) and bathypelagic waters (1001-4000 m) of the global ocean. Here, we show that the temperature dependence of PHP is fundamentally different between these major oceanic depth layers, with an estimated ecosystem-level activation energy (E) of 36 ± 7 kJ mol for the epipelagic, 72 ± 15 kJ mol for the mesopelagic and 274 ± 65 kJ mol for the bathypelagic realm. We suggest that the increasing temperature dependence with depth is related to the parallel vertical gradient in the proportion of recalcitrant organic compounds. These Ea predict an increased PHP of about 5, 12, and 55% in the epi-, meso-, and bathypelagic ocean, respectively, in response to a water temperature increase by 1°C. Hence, there is indication that a major thus far underestimated feedback mechanism exists between future bathypelagic ocean warming and heterotrophic prokaryotic activity.

  4. Aging and sexuality.

    OpenAIRE

    Holzapfel, S.

    1994-01-01

    Recent research suggesting that a high proportion of men and women remain sexually active well into later life refutes the prevailing myth that aging and sexual dysfunction are inexorably linked. Age-related physiological changes do not render a meaningful sexual relationship impossible or even necessarily difficult. In men, greater physical stimulation is required to attain and maintain erections, and orgasms are less intense. In women, menopause terminates fertility and produces changes ste...

  5. Modelling the spatio-temporal distribution of age-1 bay of biscay anchovy (Engraulis encrasicolus) at spawning time [Distribución espacio-temporal de la edad 1 de anchoa del golfo de Bizkaia (Engraulis Encrasicolus) en el momento de puesta

    KAUST Repository

    Ibaibarriaga, Leire

    2013-09-13

    To efficiently manage and maintain fish stock abundance and age structure, it is necessary to understand variability in its spatial distribution. The main objective of this study was to describe the demographic structure of the Bay of Biscay anchovy during the main spawning period based on adult samples from 15 daily egg production method surveys. The proportion of age-1 individuals was modelled using generalized additive models with a binomial distribution and a logit link in relation to geographical and environmental covariates. The possibility of obtaining different models depending on the average age-1 proportion (low or high) was also explored. In general, age-1 individuals were found in shallow waters close to the coast, especially associated with the Gironde and Adour river plumes, whereas older individuals were prevalent on the shelf break and in oceanic waters. However, in years with a high age-1 proportion the younger individuals were also dominant in oceanic waters. These results could be used for management purposes, such as defining protected areas for particular age groups.

  6. Evaluation of Recurring Esthetic Dental Proportion in Natural Mandibular Anterior Dentition

    Directory of Open Access Journals (Sweden)

    Dipti S Shah

    2015-01-01

    Results: After calculating proportions in mandibular anterior teeth, P value was found to be statistically insignificant (P > 0.05. Conclusion: Within the limitations of the study, RED proportion was not seen in mandibular natural dentition.

  7. Riding the ocean waves

    International Nuclear Information System (INIS)

    Yemm, Richard

    2000-01-01

    It is claimed that important developments over the past five years mean that there will be a range of competing pre-commercial wave-energy systems by 2002. The generation costs should be on a par with biomass schemes and offshore wind systems. The environmental advantages of wave energy are extolled. Ocean Power Delivery (OPD) have produced a set of criteria to be satisfied for a successful wave power scheme and these are listed. OPD is responsible for the snake-like Pelamis device which is a semi-submerged articulated series of cylindrical sections connected through hinged joints. How the wave-induced movement of the hinges is used to generate electricity is explained. The system is easily installed and can be completely removed at the end of its life

  8. The Ocean deserts:salt budgets of northern subtropical oceans and their

    KAUST Repository

    Carton, Jim

    2011-04-09

    The Ocean deserts: salt budgets of northern subtropical oceans and their relationship to climate variability The high salinity near surface pools of the subtropical oceans are the oceanic deserts, with high levels of evaporation and low levels of precip

  9. Structural context and variation of ocean plate stratigraphy, Franciscan Complex, California: insight into mélange origins and subduction-accretion processes

    Science.gov (United States)

    Wakabayashi, John

    2017-12-01

    The transfer (accretion) of materials from a subducting oceanic plate to a subduction-accretionary complex has produced rock assemblages recording the history of the subducted oceanic plate from formation to arrival at the trench. These rock assemblages, comprising oceanic igneous rocks progressively overlain by pelagic sedimentary rocks (chert and/or limestone) and trench-fill clastic sedimentary rocks (mostly sandstone, shale/mudstone), have been called ocean plate stratigraphy (OPS). During accretion of OPS, megathrust slip is accommodated by imbricate faults and penetrative strain, shortening the unit and leading to tectonic repetition of the OPS sequence, whereas OPS accreted at different times are separated by non-accretionary megathrust horizons. The Franciscan subduction complex of California accreted episodically over a period of over 150 million years and incorporated OPS units with a variety of characteristics separated by non-accretionary megathrust horizons. Most Franciscan OPS comprises MORB (mid-ocean-ridge basalt) progressively overlain by chert and trench-fill clastic sedimentary rocks that are composed of variable proportions of turbidites and siliciclastic and serpentinite-matrix olistostromes (sedimentary mélanges). Volumetrically, the trench-fill component predominates in most Franciscan OPS, but some units have a significant component of igneous and pelagic rocks. Ocean island basalt (OIB) overlain by limestone is less common than MORB-chert assemblages, as are abyssal serpentinized peridotite slabs. The earliest accreted OPS comprises metabasite of supra-subduction zone affinity imbricated with smaller amounts of metaultramafic rocks and metachert, but lacking a clastic component. Most deformation of Franciscan OPS is localized along discrete faults rather than being distributed in the form of penetrative strain. This deformation locally results in block-in-matrix tectonic mélanges, in contrast to the sedimentary mélanges making up part of

  10. Delta Oxygen-18 and SEA SURFACE TEMPERATURE collected from KNORR in Equatorial Pacific Ocean from 0862-01-01 to 2009-01-01 (NCEI Accession 0142201)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Tropical Pacific Ocean dynamics during the Medieval Climate Anomaly (MCA) and Little Ice Age (LIA) are poorly characterized due to lack of evidence from the eastern...

  11. Bringing an Ocean to School.

    Science.gov (United States)

    MacMillan, Mark W.

    1997-01-01

    Describes a school program in which two sixth-grade science classes researched, created, and put together an ocean museum targeted at kindergarten through eighth graders who are geographically distanced from the ocean. Details the process for investigating topical areas, organizing teams of students, researching, writing, creating displays, and…

  12. Ocean Disposal of Dredged Material

    Science.gov (United States)

    Permits and authorizations for the ocean dumping of dredged material is issued by U.S. Army Corps of Engineers. Information is provided about where to dispose dredged material and the process for obtaining an ocean dumping permit for dredged material.

  13. Environmental science: Oceans lose oxygen

    Science.gov (United States)

    Gilbert, Denis

    2017-02-01

    Oxygen is essential to most life in the ocean. An analysis shows that oxygen levels have declined by 2% in the global ocean over the past five decades, probably causing habitat loss for many fish and invertebrate species. See Letter p.335

  14. Respiratory system loop gain in normal men and women measured with proportional-assist ventilation.

    Science.gov (United States)

    Wellman, Andrew; Malhotra, Atul; Fogel, Robert B; Edwards, Jill K; Schory, Karen; White, David P

    2003-01-01

    We hypothesized that increased chemical control instability (CCI) in men could partially explain the male predominance in obstructive sleep apnea (OSA). CCI was assessed by sequentially increasing respiratory control system loop gain (LG) with proportional-assist ventilation (PAV) in 10 men (age 24-48 yr) and 9 women (age 22-36 yr) until periodic breathing or awakening occurred. Women were studied in both the follicular and luteal phases of the menstrual cycle. The amount by which PAV amplified LG was quantified from the tidal volume amplification factor [(VtAF) assisted tidal volume/unassisted tidal volume]. LG was calculated as the inverse of the VtAF occurring at the assist level immediately preceding the emergence of periodic breathing (when LG x VtAF = 1). Only 1 of 10 men and 2 of 9 women developed periodic breathing with PAV. The rest were resistant to periodic breathing despite moderately high levels of PAV amplification. We conclude that LG is low in the majority of normal men and women and that higher volume amplification factors are needed to determine whether gender differences exist in this low range.

  15. Highly discrepant proportions of female and male Scandinavian and British Isles ancestry within the isolated population of the Faroe Islands

    DEFF Research Database (Denmark)

    Als, Thomas Damm; TH, Jørgensen; Børglum, Anders

    2006-01-01

    The Faroe Islands in the North Atlantic Ocean are inhabited by a small population, whose origin is thought to date back to the Viking Age. Historical, archaeological and linguistic evidence indicates that the present population of the Faroe Islands may have a mixture of Scandinavian and British...... a frequency-based admixture approach taking private haplotypes into account by the use of phylogenetic information. While previous studies have suggested an excess of Scandinavian ancestry among the male settlers of the Faroe Islands, the current study indicates an excess of British Isles ancestry among...

  16. Economics of ocean ranching: experiences, outlook and theory

    National Research Council Canada - National Science Library

    Ragnar Arnason

    2001-01-01

    "The author distinguishes between ocean fish farming and ocean ranching. The distinguishing characteristic of ocean ranching is that the released species are unassisted once released into the ocean...

  17. Drinking water as a proportion of total human exposure to volatile N-nitrosamines.

    Science.gov (United States)

    Hrudey, Steve E; Bull, Richard J; Cotruvo, Joseph A; Paoli, Greg; Wilson, Margaret

    2013-12-01

    Some volatile N-nitrosamines, primarily N-nitrosodimethylamine (NDMA), are recognized as products of drinking water treatment at ng/L levels and as known carcinogens. The U.S. EPA has identified the N-nitrosamines as contaminants being considered for regulation as a group under the Safe Drinking Water Act. Nitrosamines are common dietary components, and a major database (over 18,000 drinking water samples) has recently been created under the Unregulated Contaminant Monitoring Rule. A Monte Carlo modeling analysis in 2007 found that drinking water contributed less than 2.8% of ingested NDMA and less than 0.02% of total NDMA exposure when estimated endogenous formation was considered. Our analysis, based upon human blood concentrations, indicates that endogenous NDMA production is larger than expected. The blood-based estimates are within the range that would be calculated from estimates based on daily urinary NDMA excretion and an estimate based on methylated guanine in DNA of lymphocytes from human volunteers. Our analysis of ingested NDMA from food and water based on Monte Carlo modeling with more complete data input shows that drinking water contributes a mean proportion of the lifetime average daily NDMA dose ranging from between 0.0002% and 0.001% for surface water systems using free chlorine or between 0.001% and 0.01% for surface water systems using chloramines. The proportions of average daily dose are higher for infants (zero to six months) than other age cohorts, with the highest mean up to 0.09% (upper 95th percentile of 0.3%). © 2013 Society for Risk Analysis.

  18. Ocean Uses: Oregon and Washington (PROUA)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Pacific Regional Ocean Uses Atlas (PROUA) Project is an innovative partnership between NOAA and the Bureau of Ocean Energy Management (BOEM) designed to...

  19. Superficial mineral resources of the Indian Ocean

    Digital Repository Service at National Institute of Oceanography (India)

    Siddiquie, H.N.; Hashimi, N.H.; Gujar, A; Valsangkar, A

    The sea floor of the Indian Ocean and the continental margins bordering the ocean are covered by a wide variety of terrigenous, biogenous and anthigenic mineral deposits. The biogenous deposits in the Indian Ocean comprise the corals on shallow...

  20. Gravity Field Atlas of the S. Ocean

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This Gravity Field Atlas of the Southern Ocean from GEOSAT is MGG Report 7. In many areas of the global ocean, the depth of the seafloor is not well known because...

  1. NCEP Global Ocean Data Assimilation System (GODAS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The GODAS dataset is a real-time ocean analysis and a reanalysis. It is used for monitoring, retrospective analysis as well as for providing oceanic initial...

  2. New Hampshire / Southern Maine Ocean Uses Atlas

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Ocean Uses Atlas Project is an innovative partnership between the Coastal Response Research Center (CRRC) and NOAA's Office of Ocean and Coastal Resource...

  3. HYbrid Coordinate Ocean Model (HYCOM): Global

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Global HYbrid Coordinate Ocean Model (HYCOM) and U.S. Navy Coupled Ocean Data Assimilation (NCODA) 3-day, daily forecast at approximately 9-km (1/12-degree)...

  4. A Trip Through the Virtual Ocean: Understanding Basic Oceanic Process Using Real Data and Collaborative Learning

    Science.gov (United States)

    Hastings, D. W.

    2012-12-01

    How can we effectively teach undergraduates the fundamentals of physical, chemical and biological processes in the ocean? Understanding physical circulation and biogeochemical processes is essential, yet it can be difficult for an undergraduate to easily grasp important concepts such as using temperature and salinity as conservative tracers, nutrient distribution, ageing of water masses, and thermocline variability. Like many other topics, it is best learned not in a lecture setting, but working with real data: plotting values, making predictions, and making mistakes. Part I: Using temperature and salinity values from any location in the world ocean (World Ocean Atlas), combined with an excellent user interface (http://ferret.pmel.noaa.gov), students are asked to answer a series of specific questions related to ocean circulation. Using established temperature and salinity values to characterize different water masses, students are able to identify various water masses and gain insight to physical circulation processes. Questions related to ocean circulation include: How far south and at what depth does NADW extend into the S. Atlantic? Is deep water formed in the North Pacific? How and why does the depth of the thermocline vary with latitude in the Atlantic Ocean? How deep does the Mediterranean Water descend as it leaves the Straits of Gibraltar? How far into the Atlantic can you see the influence of the Amazon River? Is there any Antarctic Bottom Water in the North Pacific? Collaborating with another student typically leads to increased engagement. Especially in large lecture settings, where one teacher is not able to address student questions or concerns, working in pairs or in groups of three is best. Part II: Using the same web-based viewer and data set students are subsequently assigned one oceanic property (phosphate, nitrate, silicate, O2, or AOU) and asked to construct three different plots: 1) vertical depth profile at one location; 2) latitude vs. depth

  5. Ocean carbon uptake and storage

    International Nuclear Information System (INIS)

    Tilbrook, Bronte

    2007-01-01

    Full text: The ocean contains about 95% of the carbon in the atmosphere, ocean and land biosphere system, and is of fundamental importance in regulating atmospheric carbon dioxide concentrations. In the 1990s an international research effort involving Australia was established to determine the uptake and storage of anthropogenic C02 for all major ocean basins. The research showed that about 118 of the 244 + 20 billion tons of the anthropogenic carbon emitted through fossil fuel burning and cement production has been stored in the ocean since preindustrial times, thus helping reduce the rate of increase in atmospheric C02. The research also showed the terrestrial biosphere has been a small net source of C02 (39 ± 28 billion tons carbon) to the atmosphere over the same period. About 60% of the total ocean inventory of the anthropogenic C02 was found in the Southern Hemisphere, with most in the 30 0 S to 50 0 S latitude band. This mid-latitude band is where surface waters are subducted as Mode and Intermediate waters, which is a major pathway controlling ocean C02 uptake. High storage (23% of the total) also occurs in the North Atlantic, associated with deep water formation in that basin. The ocean uptake and storage is expected to increase in the coming decades as atmospheric C02 concentrations rise. However, a number of feedback mechanisms associated with surface warming, changes in circulation, and biological effects are likely to impact on the uptake capacity. The accumulation or storage-of the C02 in the ocean is also the major driver of ocean acidification with potential to disrupt marine ecosystems. This talk will describe the current understanding of the ocean C02 uptake and storage and a new international research strategy to detect how the ocean uptake and storage will evolve on interannual through decadal scales. Understanding the ocean response to increasing atmospheric C02 will be a key element in managing future C02 increases and establishing

  6. Green sea turtle age, growth, population characteristics

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Morphology, sex ratio, body condition, disease status, age structure, and growth patterns were characterized for 448 green sea turtles cold stunned in St. Joseph...

  7. Subjective Proportions: 18th-Century Interpretations of Paestum’s ‘Disproportion’

    Directory of Open Access Journals (Sweden)

    Sigrid de Jong

    2016-02-01

    Full Text Available When 18th-century travellers saw the Doric temples of Paestum in Southern Italy with their own eyes, they observed for the first time true examples of the proportions of archaic Greek architecture. Contrary to the Roman proportional systems, the Greek ones had been largely unavailable to architects until then. With the rediscovery of Paestum, conveniently located south of Naples and not in far away Greece, the secret of Greek proportions was no more. Architects were able to precisely measure the temples and wrote many accounts about their primitive forms and proportions. But what did architects mean exactly when describing the proportions as primitive? What kinds of reflections did these proportions provoke? This article treats proportions as aesthetics, or as visible proportions, not as a numerical system. The discourse on proportions changed in this period, giving more weight to their cultural and historical meaning. The writings by such architects as Soane, Wilkins, and Labrouste demonstrate how Paestum functioned as a laboratory to unveil the secret of primitive proportions, and how, with the different meanings architects attached to them, it enlarged and renewed the debate on proportions.

  8. Leg length, sitting height, and body proportions references for achondroplasia: New tools for monitoring growth.

    Science.gov (United States)

    Del Pino, Mariana; Ramos Mejía, Rosario; Fano, Virginia

    2018-04-01

    Achondroplasia is the most common form of inherited disproportionate short stature. We report leg length, sitting height, and body proportion curves for achondroplasia. Seven centile format of sitting height, leg length, sitting height/leg length ratio, sitting height/height ratio, and head circumference/height ratio were estimated by the LMS method. The Q-test was applied to assess the goodness of fit. For comparison, centiles of sitting height and leg length were graphed using Argentine national growth references for achondroplasia and non-achondroplasia populations. The sample consisted of 342 children with achondroplasia (171 males, 171 females) aged 0-18 years. The median (interquartile range) number of measurements per child was 6 (3, 12) for sitting height and 8 (3, 13) for head circumference. Median leg length increased from 14 cm at age 1 week to 44 and 40 cm (males and females, respectively) in achondroplasia adolescents which is 3.5 cm shorter than non-achondroplasia children at age 1 week and, 38 cm shorter at adolescence. Median sitting height increased from 34 cm at birth to 86 and 81 in adolescents' boys and girls respectively, only 5 cm shorter than non-achondroplasia children. Sitting height/leg length decreased from 2.61 at birth to approximately 1.90 at adolescent. Median head circumference/height ratio decreased from 0.79 at birth to 0.46 at 18 years in both sexes. Growth of lower limbs is affected early in life and becomes more noticeable throughout childhood. The disharmonic growth between the less affected trunk and the severely affected limbs determine body disproportion in achondroplasia. © 2018 Wiley Periodicals, Inc.

  9. Proportional reasoning as a heuristic-based process: time constraint and dual task considerations.

    Science.gov (United States)

    Gillard, Ellen; Van Dooren, Wim; Schaeken, Walter; Verschaffel, Lieven

    2009-01-01

    The present study interprets the overuse of proportional solution methods from a dual process framework. Dual process theories claim that analytic operations involve time-consuming executive processing, whereas heuristic operations are fast and automatic. In two experiments to test whether proportional reasoning is heuristic-based, the participants solved "proportional" problems, for which proportional solution methods provide correct answers, and "nonproportional" problems known to elicit incorrect answers based on the assumption of proportionality. In Experiment 1, the available solution time was restricted. In Experiment 2, the executive resources were burdened with a secondary task. Both manipulations induced an increase in proportional answers and a decrease in correct answers to nonproportional problems. These results support the hypothesis that the choice for proportional methods is heuristic-based.

  10. Development of Proportional Pressure Control Valve for Hydraulic Braking Actuator of Automobile ABS

    Directory of Open Access Journals (Sweden)

    Che-Pin Chen

    2018-04-01

    Full Text Available This research developed a novel proportional pressure control valve for an automobile hydraulic braking actuator. It also analyzed and simulated solenoid force of the control valves, and the pressure relief capability test of electromagnetic thrust with the proportional valve body. Considering the high controllability and ease of production, the driver of this proportional valve was designed with a small volume and powerful solenoid force to control braking pressure and flow. Since the proportional valve can have closed-loop control, the proportional valve can replace a conventional solenoid valve in current brake actuators. With the proportional valve controlling braking and pressure relief mode, it can narrow the space of hydraulic braking actuator, and precisely control braking force to achieve safety objectives. Finally, the proposed novel proportional pressure control valve of an automobile hydraulic braking actuator was implemented and verified experimentally.

  11. How does ocean ventilation change under global warming?

    Directory of Open Access Journals (Sweden)

    A. Gnanadesikan

    2007-01-01

    Full Text Available Since the upper ocean takes up much of the heat added to the earth system by anthropogenic global warming, one would expect that global warming would lead to an increase in stratification and a decrease in the ventilation of the ocean interior. However, multiple simulations in global coupled climate models using an ideal age tracer which is set to zero in the mixed layer and ages at 1 yr/yr outside this layer show that the intermediate depths in the low latitudes, Northwest Atlantic, and parts of the Arctic Ocean become younger under global warming. This paper reconciles these apparently contradictory trends, showing that the decreases result from changes in the relative contributions of old deep waters and younger surface waters. Implications for the tropical oxygen minimum zones, which play a critical role in global biogeochemical cycling are considered in detail.

  12. Moving beyond the age-depth model paradigm in deep-sea palaeoclimate archives: dual radiocarbon and stable isotope analysis on single foraminifera

    Science.gov (United States)

    Lougheed, Bryan C.; Metcalfe, Brett; Ninnemann, Ulysses S.; Wacker, Lukas

    2018-04-01

    Late-glacial palaeoclimate reconstructions from deep-sea sediment archives provide valuable insight into past rapid changes in ocean chemistry. Unfortunately, only a small proportion of the ocean floor with sufficiently high sediment accumulation rate (SAR) is suitable for such reconstructions using the long-standing age-depth model approach. We employ ultra-small radiocarbon (14C) dating on single microscopic foraminifera to demonstrate that the long-standing age-depth model method conceals large age uncertainties caused by post-depositional sediment mixing, meaning that existing studies may underestimate total geochronological error. We find that the age-depth distribution of our 14C-dated single foraminifera is in good agreement with existing bioturbation models only after one takes the possibility of Zoophycos burrowing into account. To overcome the problems associated with the age-depth paradigm, we use the first ever dual 14C and stable isotope (δ18O and δ13C) analysis on single microscopic foraminifera to produce a palaeoclimate time series independent of the age-depth paradigm. This new state of the art essentially decouples single foraminifera from the age-depth paradigm to provide multiple floating, temporal snapshots of ocean chemistry, thus allowing for the successful extraction of temporally accurate palaeoclimate data from low-SAR deep-sea archives. This new method can address large geographical gaps in late-glacial benthic palaeoceanographic reconstructions by opening up vast areas of previously disregarded, low-SAR deep-sea archives to research, which will lead to an improved understanding of the global interaction between oceans and climate.

  13. Ocean uptake of carbon dioxide

    International Nuclear Information System (INIS)

    Peng, Tsung-Hung; Takahashi, Taro

    1993-01-01

    Factors controlling the capacity of the ocean for taking up anthropogenic C0 2 include carbon chemistry, distribution of alkalinity, pCO 2 and total concentration of dissolved C0 2 , sea-air pCO 2 difference, gas exchange rate across the sea-air interface, biological carbon pump, ocean water circulation and mixing, and dissolution of carbonate in deep sea sediments. A general review of these processes is given and models of ocean-atmosphere system based on our understanding of these regulating processes axe used to estimate the magnitude of C0 2 uptake by the ocean. We conclude that the ocean can absorb up to 35% of the fossil fuel emission. Direct measurements show that 55% Of C0 2 from fossil fuel burning remains in the atmosphere. The remaining 10% is not accounted for by atmospheric increases and ocean uptake. In addition, it is estimated that an amount equivalent to 30% of recent annual fossil fuel emissions is released into the atmosphere as a result of deforestation and farming. To balance global carbon budget, a sizable carbon sink besides the ocean is needed. Storage of carbon in terrestrial biosphere as a result of C0 2 fertilization is a potential candidate for such missing carbon sinks

  14. The relative proportion of preterm births complicated by premature rupture of membranes in multifetal gestations: a population-based study.

    Science.gov (United States)

    Pakrashi, Tarita; Defranco, Emily A

    2013-01-01

    To compare the relative contribution of premature rupture of membranes (PROM) to preterm births in singleton compared with multifetal gestations. A population-based retrospective cohort study of 291,782 nonanomalous live births in the state of Ohio from January 1, 2006, to December 31, 2007, identified through birth certificate data. Frequency of PROM was compared between singleton and multifetal gestations and then stratified by gestational age at birth. Multivariate regression analysis estimated the risk of PROM by plurality in each gestational age group, accounting for influential risk factors. The frequency of PROM increased with increasing plurality of gestation. The relative proportion of preterm birth < 37 weeks complicated by PROM increased with gestational plurality 13.2% singletons, 16.8% twins, 20.0% triplets, 19.6% quadruplets, and 100% for higher-order multiples (p < 0.001). The frequency of PROM increased with earlier gestational age at birth, regardless of plurality. The increased risk of PROM in multifetal gestation persisted even after adjustment for influential concomitant risk factors. The proportion of preterm birth attributable to PROM increases by plurality of gestation, with its most significant contribution in higher-order multiples and at earliest gestational ages when outcomes are the poorest. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  15. Ocean One: A Robotic Avatar for Oceanic Discovery

    KAUST Repository

    Khatib, Oussama; Yeh, Xiyang; Brantner, Gerald; Soe, Brian; Kim, Boyeon; Ganguly, Shameek; Stuart, Hannah; Wang, Shiquan; Cutkosky, Mark; Edsinger, Aaron; Mullins, Phillip; Barham, Mitchell; Voolstra, Christian R.; Salama, Khaled N.; L'Hour, Michel; Creuze, Vincent

    2016-01-01

    The promise of oceanic discovery has long intrigued scientists and explorers, whether with the idea of studying underwater ecology and climate change or with the hope of uncovering natural resources and historic secrets buried deep in archaeological sites. This quest to explore the oceans requires skilled human access, yet much of the oceans are inaccessible to human divers; nearly ninetenths of the ocean floor is at 1 km or deeper [1]. Accessing these depths is imperative since factors such as pollution and deep-sea trawling threaten ecology and archaeological sites. While remotely operated vehicles (ROVs) are inadequate for the task, a robotic avatar could go where humans cannot and still embody human intelligence and intentions through immersive interfaces.

  16. Ocean One: A Robotic Avatar for Oceanic Discovery

    KAUST Repository

    Khatib, Oussama

    2016-11-11

    The promise of oceanic discovery has long intrigued scientists and explorers, whether with the idea of studying underwater ecology and climate change or with the hope of uncovering natural resources and historic secrets buried deep in archaeological sites. This quest to explore the oceans requires skilled human access, yet much of the oceans are inaccessible to human divers; nearly ninetenths of the ocean floor is at 1 km or deeper [1]. Accessing these depths is imperative since factors such as pollution and deep-sea trawling threaten ecology and archaeological sites. While remotely operated vehicles (ROVs) are inadequate for the task, a robotic avatar could go where humans cannot and still embody human intelligence and intentions through immersive interfaces.

  17. 12. Oceans and coasts

    International Nuclear Information System (INIS)

    Paden, M.; Seligman, D.; Weber, M.

    1992-01-01

    The trends of the past 20 years show increasing coastal pollution, accelerated destruction of coastal marine habitats, and, in many areas, a declining catch of marine fish species that have been affected by overfishing and pollution. Stopping land-based pollution, especially pollutants from runoff, requires entering a new political arena, contesting powerful interests in agriculture and industry, and dealing with a nearly worldwide economic framework that allows land-based pollutant sources to dispose of their wastes in waterways at no direct cost. The paper discusses these topics under the following headings: pollution trends (nutrient pollution, human health problems, toxic chemical pollution); coastal habitat destruction (coral reef bleaching, threats to the ocean's surface); fisheries trends; aquaculture; a regional approach to preventing pollution [trends in marine pollution control, upstream activities that pollute coastal waters (logging, agriculture, dam construction and irrigation, cities and industry, air pollution)], vulnerability of coastal waters to pollution, coordinating pollution control (linking the land and the water), case studies of watershed/coastal management (Phuket Province, Thailand; the Chesapeake Bay; the Mediterranean)

  18. Radioactivity in the oceans

    International Nuclear Information System (INIS)

    Templeton, W.L.

    1979-01-01

    While the revised ''Definition and Recommendations'' of the International Atomic Energy Agency (IAEA) restricts the dumping of the radioactive wastes that exceed specified concentration/mass limits, the acceptance of the concept of applying the release rate limits as developed by the IAEA provides a rational basis for further considering the emplacement of radioactive wastes in seabed as an attractive and acceptable alternative to terrestrial geological repositories. The technical basis for the present radiological assessment is on release rate limits and not on dumping rates. However, to meet the present requirements of the London Convention, it is necessary to express to Definition in terms of the concentration in a single site and the assumed upper limit on mass dumping rate at a single site of 100,000 tons/year with the added proviso of release rate limits for the finite ocean volume of 10 17 m 3 . This results in the concentration limits of a) 1 Ci/ton for α-emitters but limited to 10 -1 Ci/ton 226 Ra and supported 210 Po; b) 10 2 Ci/ton for β/γ-emitters with half-lives of at least 0.5 yr (excluding 3 H) and the mixtures of β/γ-emitters of unknown half-lives; and c) 10 6 Ci/ton for 3 H and the β/γ-emitters with half-lives less than 0.5 yr. (Yamashita, S.)

  19. Genetics of human body size and shape: body proportions and indices.

    Science.gov (United States)

    Livshits, Gregory; Roset, A; Yakovenko, K; Trofimov, S; Kobyliansky, E

    2002-01-01

    The study of the genetic component in morphological variables such as body height and weight, head and chest circumference, etc. has a rather long history. However, only a few studies investigated body proportions and configuration. The major aim of the present study was to evaluate the extent of the possible genetic effects on the inter-individual variation of a number of body configuration indices amenable to clear functional interpretation. Two ethnically different pedigree samples were used in the study: (1) Turkmenians (805 individuals) from Central Asia, and (2) Chuvasha (732 individuals) from the Volga riverside, Russian Federation. To achieve the aim of the present study we proposed three new indices, which were subjected to a statistical-genetic analysis using modified version of "FISHER" software. The proposed indices were: (1) an integral index of torso volume (IND#1), an index reflecting a predisposition of body proportions to maintain a balance in a vertical position (IND#2), and an index of skeletal extremities volume (IND#3). Additionally, the first two principal factors (PF1 and PF2) obtained on 19 measurements of body length and breadth were subjected to genetic analysis. Variance decomposition analysis that simultaneously assess the contribution of gender, age, additive genetic effects and effects of environment shared by the nuclear family members, was applied to fit variation of the above three indices, and PF1 and PF2. The raw familial correlation of all study traits and in both samples showed: (1) all marital correlations did not differ significantly from zero; (2) parent-offspring and sibling correlations were all positive and statistically significant. The parameter estimates obtained in variance analyses showed that from 40% to 75% of inter-individual variation of the studied traits (adjusted for age and sex) were attributable to genetic effects. For PF1 and PF2 in both samples, and for IND#2 (in Chuvasha pedigrees), significant common sib

  20. Chaotic advection in the ocean

    Energy Technology Data Exchange (ETDEWEB)

    Koshel' , Konstantin V; Prants, Sergei V [V.I. Il' ichev Pacific Oceanological Institute, Far-Eastern Division of the Russian Academy of Sciences, Vladivostok (Russian Federation)

    2006-11-30

    The problem of chaotic advection of passive scalars in the ocean and its topological, dynamical, and fractal properties are considered from the standpoint of the theory of dynamical systems. Analytic and numerical results on Lagrangian transport and mixing in kinematic and dynamic chaotic advection models are described for meandering jet currents, topographical eddies in a barotropic ocean, and a two-layer baroclinic ocean. Laboratory experiments on hydrodynamic flows in rotating tanks as an imitation of geophysical chaotic advection are described. Perspectives of a dynamical system approach in physical oceanography are discussed. (reviews of topical problems)