Managing "Academic Value": The 360-Degree Perspective

Science.gov (United States)

Wilson, Margaret R.; Corr, Philip J.

2018-01-01

The "raison d'etre" of all universities is to create and deliver "academic value", which we define as the sum total of the contributions from the 360-degree "angles" of the academic community, including all categories of staff, as well as external stakeholders (e.g. regulatory, commercial, professional and community…

What is the (Real Option) Value of a College Degree?

OpenAIRE

Jeffrey R. Stokes

2013-01-01

The value of a college degree is often quantified as the difference in earnings between those with and without a degree. The research presented here operationalizes this idea in two important ways. First, since future income and tuition are uncertain, a contingent claims model is developed and the appropriate discount rate for valuing future earnings is, therefore, endogenized given an economy that does not permit arbitrage. Second, the model is sensitive to the valuation of the real option t...

Anaerobic Transformation of Furfural by Methanococcus deltae (Delta)LH

Science.gov (United States)

Belay, N.; Boopathy, R.; Voskuilen, G.

1997-01-01

Methanococcus deltae (Delta)LH was grown on H(inf2)-CO(inf2) in the presence of various concentrations of furfural. Furfural at higher concentrations, namely, 20 and 25 mM, inhibited growth of this organism. At concentration of 5 and 10 mM, no inhibition of growth was observed. The other methanogens in this study were not inhibited by 10 mM furfural. Among the methanogens tested, M. deltae was capable of transforming furfural, whereas Methanobacterium thermoautotrophicum Marburg, Methanosarcina barkeri 227, Methanococcus thermolithotrophicus, and Methanobrevibacter ruminantium lacked this capability. One hundred percent removal of furfural was observed within 48 h of incubation in M. deltae cultures. The end product observed during furfural metabolism was furfuryl alcohol. An almost stoichiometric amount of furfuryl alcohol was produced by M. deltae. This transformation is likely to be of value in the detoxification of furfural and in its ultimate conversion to methane and CO(inf2) by anaerobic digestion. PMID:16535618

In-situ Kd values and geochemical behavior for inorganic and organic constituents of concern at the TNX Outfall Delta

International Nuclear Information System (INIS)

Kaplan, D.I.

2000-01-01

A series of tests were conducted to provide site-specific Kd values for constituents of concern at the TNX Outfall Delta Operable Unit. These Kd values can be used to calculate contaminant migration within the operable unit and are, at this time considered to be the most defensible values

Financial Performance of Hospitals in the Mississippi Delta Region Under the Hospital Readmissions Reduction Program and Hospital Value-based Purchasing Program.

Science.gov (United States)

Chen, Hsueh-Fen; Karim, Saleema; Wan, Fei; Nevola, Adrienne; Morris, Michael E; Bird, T Mac; Tilford, J Mick

2017-11-01

Previous studies showed that the Hospital Readmissions Reduction Program (HRRP) and the Hospital Value-based Purchasing Program (HVBP) disproportionately penalized hospitals caring for the poor. The Mississippi Delta Region (Delta Region) is among the most socioeconomically disadvantaged areas in the United States. The financial performance of hospitals in the Delta Region under both HRRP and HVBP remains unclear. To compare the differences in financial performance under both HRRP and HVBP between hospitals in the Delta Region (Delta hospitals) and others in the nation (non-Delta hospitals). We used a 7-year panel dataset and applied difference-in-difference models to examine operating and total margin between Delta and non-Delta hospitals in 3 time periods: preperiod (2008-2010); postperiod 1 (2011-2012); and postperiod 2 (2013-2014). The Delta hospitals had a 0.89% and 4.24% reduction in operating margin in postperiods 1 and 2, respectively, whereas the non-Delta hospitals had 1.13% and 1% increases in operating margin in postperiods 1 and 2, respectively. The disparity in total margins also widened as Delta hospitals had a 1.98% increase in postperiod 1, but a 0.30% reduction in postperiod 2, whereas non-Delta hospitals had 1.27% and 2.28% increases in postperiods 1 and 2, respectively. The gap in financial performance between Delta and non-Delta hospitals widened following the implementation of HRRP and HVBP. Policy makers should modify these 2 programs to ensure that resources are not moved from the communities that need them most.

Do Employers Value the Bachelor's Degree Too Much?

Science.gov (United States)

Sigelman, Matt

2014-01-01

The debate over the value of a college education appears to be settled, not only do employers value employees with a bachelor's degree, they may actually value them too much. This author believes that there is a dramatic credentials gap in the American workforce between the education levels employers are requesting in job postings and the…

Hepatitis delta genotypes in chronic delta infection in the northeast of Spain (Catalonia).

Science.gov (United States)

Cotrina, M; Buti, M; Jardi, R; Quer, J; Rodriguez, F; Pascual, C; Esteban, R; Guardia, J

1998-06-01

Based on genetic analysis of variants obtained around the world, three genotypes of the hepatitis delta virus have been defined. Hepatitis delta virus variants have been associated with different disease patterns and geographic distributions. To determine the prevalence of hepatitis delta virus genotypes in the northeast of Spain (Catalonia) and the correlation with transmission routes and clinical disease, we studied the nucleotide divergence of the consensus sequence of HDV RNA obtained from 33 patients with chronic delta hepatitis (24 were intravenous drug users and nine had no risk factors), and four patients with acute self-limited delta infection. Serum HDV RNA was amplified by the polymerase chain reaction technique and a fragment of 350 nucleotides (nt 910 to 1259) was directly sequenced. Genetic analysis of the nucleotide consensus sequence obtained showed a high degree of conservation among sequences (93% of mean). Comparison of these sequences with those derived from different geographic areas and pertaining to genotypes I, II and III, showed a mean sequence identity of 92% with genotype I, 73% with genotype II and 61% with genotype III. At the amino acid level (aa 115 to 214), the mean identity was 87% with genotype I, 63% with genotype II and 56% with genotype III. Conserved regions included the RNA editing domain, the carboxyl terminal 19 amino acids of the hepatitis delta antigen and the polyadenylation signal of the viral mRNA. Hepatitis delta virus isolates in the northeast of Spain are exclusively genotype I, independently of the transmission route and the type of infection. No hepatitis delta virus subgenotypes were found, suggesting that the origin of hepatitis delta virus infection in our geographical area is homogeneous.

Equation of state for isospin asymmetric matter of nucleons and deltas

International Nuclear Information System (INIS)

Lu Xiaohua; Zhang Yingxun; Li Zhuxia; Zhao Zhixiang

2008-01-01

An investigation on the equation of state of the isospin asymmetric, hot, dense matter of nucleons and deltas is performed based on the relativistic mean field theory. The QHD-II-type effective Lagrangian extending to the delta degree of freedom is adopted. Our results show that the equation of state is softened due to the inclusion of the delta degree of freedom. The baryon resonance isomer may occur depending on the delta-meson coupling. The results show that the densities for appearing the baryon resonance isomer, the densities for starting softening the equation of state and the extent of the softening depend not only on the temperature, the coupling strengths but also the isospin asymmetry of the baryon matter. (authors)

{Delta}r in the Two-Higgs-Doublet Model at full one loop level - and beyond

Energy Technology Data Exchange (ETDEWEB)

Lopez-Val, David [Universitaet Heidelberg, Institut fuer Theoretische Physik, Heidelberg (Germany); Sola, Joan [Universitat de Barcelona, Dept. Estructura i Constituents de la Materia, Barcelona, Catalonia (Spain); Institut de Ciencies del Cosmos, Barcelona, Catalonia (Spain)

2013-04-15

After the recent discovery of a Higgs-like boson particle at the CERN LHC-collider, it becomes more necessary than ever to prepare ourselves for identifying its standard or non-standard nature. The fundamental parameter {Delta}r, relating the values of the electroweak gauge boson masses and the Fermi constant, is the traditional observable encoding high precision information of the quantum effects. In this work we present a complete quantitative study of {Delta}r in the framework of the general Two-Higgs-Doublet Model (2HDM). While the one-loop analysis of {Delta}r in this model was carried out long ago, in the first part of our work we consistently incorporate the higher order effects that have been computed since then for the SM part of {Delta}r. Within the on-shell scheme, we find typical corrections leading to shifts of {proportional_to}20-40 MeV on the W mass, resulting in a better agreement with its experimentally measured value and in a degree no less significant than in the MSSM case. In the second part of our study we devise a set of effective couplings that capture the dominant higher order genuine 2HDM quantum effects on the {delta}{rho} part of {Delta}r in the limit of large Higgs boson self-interactions. This limit constitutes a telltale property of the general 2HDM which is unmatched by e.g. the MSSM. (orig.)

Delta-nucleus dynamics: proceedings of symposium

Energy Technology Data Exchange (ETDEWEB)

Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P. (eds.)

1983-10-01

The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta ..delta..(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe ..delta..-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented. (WHK)

Within-canopy and ozone fumigation effects on delta13C and Delta18O in adult beech (Fagus sylvatica) trees: relation to meteorological and gas exchange parameters.

Science.gov (United States)

Gessler, Arthur; Löw, Markus; Heerdt, Christian; de Beeck, Maarten Op; Schumacher, Johannes; Grams, Thorsten E E; Bahnweg, Günther; Ceulemans, Reinhart; Werner, Herbert; Matyssek, Rainer; Rennenberg, Heinz; Haberer, Kristine

2009-11-01

In this study, the effects of different light intensities either in direct sunlight or in the shade crown of adult beech (Fagus sylvatica L.) trees on delta13C and Delta18O were determined under ambient (1 x O3) and twice-ambient (2 x O3) atmospheric ozone concentrations during two consecutive years (2003 and 2004). We analysed the isotopic composition in leaf bulk, leaf cellulose, phloem and xylem material and related the results to (a) meteorological data (air temperature, T and relative humidity, RH), (b) leaf gas exchange measurements (stomatal conductance, g(s); transpiration rate, E; and maximum photosynthetic activity, A(max)) and (c) the outcome of a steady-state evaporative enrichment model. Delta13C was significantly lower in the shade than in the sun crown in all plant materials, whilst Delta18O was increased significantly in the shade than in the sun crown in bulk material and cellulose. Elevated ozone had no effect on delta13C, although Delta18O was influenced by ozone to varied degrees during single months. We observed significant seasonal changes for both parameters, especially in 2004, and also significant differences between the study years. Relating the findings to meteorological data and gas exchange parameters, we conclude that the differences in Delta18O between the sun and the shade crown were predominantly caused by the Péclet effect. This assumption was supported by the modelled Delta18O values for leaf cellulose. It was demonstrated that independent of RH, light-dependent reduction of stomatal conductance (and thus transpiration) and of A(max) can drive the pattern of Delta18O increase with the concomitant decrease of delta13C in the shade crown. The effect of doubling ozone levels on time-integrated stomatal conductance and transpiration as indicated by the combined analysis of Delta18O and delta13C was much lower than the influence caused by the light exposure.

An Empirical Investigation of the Financial Value of a College Degree

Science.gov (United States)

Lobo, Bento J.; Burke-Smalley, Lisa A.

2018-01-01

We generate selection-adjusted NPV and IRR estimates for a bachelor's degree in the U.S. which account for time-to-graduation, debt financing and tuition levels. We find that a college degree is generally worthwhile, but the private value of the investment is a declining function of time-to-graduation. Selection-adjustments show that for students…

Oxygen nonstoichiometry and ionic transport properties of La0.4Sr0.6CoO3-delta .

Science.gov (United States)

Sitte, W; Bucher, E; Benisek, A; Preis, W

2001-09-01

Homogeneous samples of La0.4Sr0.6CoO3-delta were obtained by the glycine nitrate process. The oxygen nonstoichiometry was determined from oxygen exchange measurements as a function of oxygen partial pressure (10(-4) bar PO2 PO2-range between 10(-4) and 10(-2) bar to yield D and the ionic conductivity sigma(i) from the long time solution of the diffusion equation. Values for D from polarization measurements at T= 775 degrees C and from oxygen exchange measurements at T= 725 degrees C are in good agreement with each other. D and sigma(1) increase with increasing PO2 (10(-4) to 10(-2) bar). The ionic conductivity shows a maximum at 3-delta approximately 2.82 and decreases with decreasing oxygen content indicating the possible formation of vacancy ordered structures.

Concentrations and (delta)13C values of atmospheric CO2 from oceanic atmosphere through time: polluted and non-polluted areas

International Nuclear Information System (INIS)

Longinelli, Antonio; Selmo, Enrico; Lenaz, Renzo; Ori, Carlo

2005-01-01

CO 2 is one of the primary agents of global climate changes. The increase of atmospheric CO 2 concentration is essentially related to human-induced emissions and, particularly, to the burning of fossil fuel whose (delta) 13 C values are quite negative. Consequently, an increase of the CO 2 concentration in the atmosphere should be paralleled by a decrease of its (delta) 13 C. Continuous and/or spot measurements of CO 2 concentrations were repeatedly carried out during the last decade and in the same period of the year along hemispheric courses from Italy to Antarctica on a vessel of the Italian National Research Program in Antarctica. During these expeditions, discrete air samples were also collected in 4-l Pyrex flasks in order to carry out precise carbon isotope analyses on atmospheric CO 2 from different areas, including theoretically 'clean' open ocean areas, with the main purpose of comparing these open ocean results with the results obtained by the National Oceanic and Atmospheric Administration/World Meteorological Organization (NOAA/WMO) at land-based stations. According to the data obtained for these two variables, a relatively large atmospheric pollution is apparent in the Mediterranean area where the CO 2 concentration has reached the value of 384 ppmv while quite negative (delta) 13 C values have been measured only occasionally. In this area, southerly winds probably help to reduce the effect of atmospheric pollution even though, despite a large variability of CO 2 concentrations, these values are consistently higher than those measured in open ocean areas by a few ppmv to about 10 ppmv. A marked, though non-continuous, pollution is apparent in the area of the Bab-el-Mandeb strait where (delta) 13 C values considerably more negative than in the Central and Southern Red Sea were measured. The concentration of atmospheric CO 2 over the Central Indian Ocean increased from about 361 ppmv at the end of 1996 to about 373 ppmv at the end of 2003 (mean growth

Atmospheric CO2 concentrations and (delta)13C values across the Antarctic Circumpolar Current between New Zealand and Antarctica

International Nuclear Information System (INIS)

Longinelli, Antonio; Selmo, Enricomaria; Giglio, Federico; Langone, Leonardo; Lenaz, Renzo; Ori, Carlo

2007-01-01

Measurements of atmospheric CO 2 concentrations were repeatedly carried out on the vessel 'Italica' of the Italian National Research Program in Antarctica, during cruises from Italy to Antarctica. Discrete air samples were also collected in 4-L Pyrex flasks during these cruises in order to carry out (delta) 13 C analyses on atmospheric CO 2 . The results acquired between New Zealand and Antarctica are reported here. The mean growth rate of the CO 2 concentration from 1996 to 2003 in this area of the Southern Oceans is of about 1.8 ppmv/yr, in good agreement with NOAA/CMDL measurements. The rates of increase from cruise to cruise are rather variable. From 1996-1997 to 1998-1999 cruise the yearly growth rate is 2.75 ppmv/yr, close to the large growth rates measured in several areas and mainly related to the most severe El Nino event of the last years. The other yearly growth rates are of about 1.3 and 2 ppmv for the periods 1998-1999 to 2001-2002 and 2001-2002 to 2003-2004, respectively. The large difference between these two values is probably related to the uncertainty on the only two 2001-2002 discrete measurements of CO 2 concentration in this area. The measured (delta) 13 C values show two completely different distributions and a large interannual variability. The 1998-1999, 2002-2003, and 2003-2004 results obtained between about 55 deg S and 65 deg S across the Antarctic Polar Front show a marked negativization of up to more than 0.2% when compared to the background values. The results are related to local source regions of CO 2 , as frequently found in the Southern Ocean by several authors; the negative (delta) 13 C values are tentatively related to the possible contribution of different causes. Among them, the southward negative gradient of (delta) 13 C of the dissolved inorganic carbon, the contribution from upwelling deep waters and from subsurface processes between the Northern SubAntarctic Front and the Polar Front, and, partly, the contribution of CO 2

Losses of Sacramento River Chinook Salmon and Delta Smelt to Entrainment in Water Diversions in the Sacramento–San Joaquin Delta

Directory of Open Access Journals (Sweden)

Wim J. Kimmerer

2008-06-01

Full Text Available Pumping at the water export facilities in the southern Sacramento-San Joaquin Delta kills fish at and near the associated fish-salvage facilities. Correlative analyses of salvage counts with population indices have failed to provide quantitative estimates of the magnitude of this mortality. I estimated the proportional losses of Sacramento River Chinook salmon (Oncorhynchus tshawytscha and delta smelt (Hypomesus transpacificus to place these losses in a population context. The estimate for salmon was based on recoveries of tagged smolts released in the upper Sacramento River basin, and recovered at the fish-salvage facilities in the south Delta and in a trawling program in the western Delta. The proportion of fish salvaged increased with export flow, with a mean value around 10% at the highest export flows recorded. Mortality was around 10% if pre-salvage losses were about 80%, but this value is nearly unconstrained. Losses of adult delta smelt in winter and young delta smelt in spring were estimated from salvage data (adults corrected for estimated pre-salvage survival, or from trawl data in the southern Delta (young. These losses were divided by population size and accumulated over the respective seasons. Losses of adult delta smelt were 1–50% (median 15% although the highest value may have been biased upward. Daily losses of larvae and juveniles were 0–8%, and seasonal losses accumulated were 0–25% (median 13%. The effect of these losses on population abundance was obscured by subsequent 50-fold variability in survival from summer to fall.

Incorporation of Socio-Cultural Values in Damage Assessment Valuations of Contaminated Lands in the Niger Delta

Directory of Open Access Journals (Sweden)

Victor A. Akujuru

2014-07-01

Full Text Available Damages on contaminated land have been mostly assessed for developments subsisting on the land, neglecting the goods and services derived from the land which possess only socio-cultural values. This paper aims to ascertain the importance of socio-cultural values in the total economic value of contaminated land, drawing from the experience of a coastal community oil spillage in the Niger Delta. The paper examines what constitutes a valuable interest on contaminated land and how socio-cultural factors are valued in the damage assessment process. After reviewing the literature and decided cases, a questionnaire survey was conducted and a sample valuation report was analysed. It is concluded that there exists a socio-cultural interest on contaminated land which professional valuers do not reflect in damage assessment claims. It is recommended that any comprehensive damage assessment requires the incorporation of socio-cultural values in the valuations.

Evaluation of DELTA(1232) components in sup 1 sup 2 C

CERN Document Server

Bystritsky, V M; Krechetov, Yu F; Saigushkin, O K; Tabachenko, A N; Schuvalov, E N; Grabmayr, R; Fiks, A I

2001-01-01

One measured cross section of sup 1 sup 2 C(gamma, pi sup + p) reaction within DELTA(1232)-isobar range. Data analysis was carried out using model taking account of both nucleon and isobar degrees of freedom of sup 1 sup 2 C nucleus. One makes a conclusion that within high transmitted pulses pi sup + p-pairs are formed during DELTA sup + sup + -isobar direct knocking-out of a nucleus. One estimated the probability to determine DELTA-isobar in sup 1 sup 2 C nucleus ground state equal to 0.018 +- 0.005 DELTA-isobar per nucleon

Application Value of Slider-Crank Mechanism in Pick-and-Place Operation of Delta Robot

Directory of Open Access Journals (Sweden)

Zhe QIN

2018-01-01

Full Text Available By absorbing the advantages of the rotary-driven Delta robot and linear-driven Delta robot, a Delta robot for pick-and-place operation that forms a crank-slider at the drive joint is designed.To take the most common gate shaped curve in Cartesian space as the motion trail of robotic pick-and-place operation, according to the kinematics inverse solution theory of Delta robot, this thesis mainly solves the output angular velocity of robot-driven joint. Establishing the static transfer mathematical model and solving the forced condition of driving joint. The simulation analysis show that after the upper slider-crank mechanism is connected to the driving joint, the angular velocity of the driving joint changes suddenly, which caused a rigid impact on the robot in the picking and releasing operation, though the force of the driving joint can be made smaller.

Initial isotopic geochemistry ({delta} 18 O, {delta} D) of fluids from wells of the Los Humeros, Pue., geothermal field; Geoquimica isotopica ({delta} 18 O, {delta} D) inicial de fluidos de pozos del campo geotermico de Los Humeros, Pue.

Energy Technology Data Exchange (ETDEWEB)

Barragan Reyes, Rosa Maria; Arellano Gomez, Victor Manuel [Instituto de Investigaciones Electricas, Gerencia de Geotermia, Cuernavaca, Morelos (Mexico)]. E-mail: rmb@iie.org.mx; Ramirez Montes, Miguel; Tovar Aguado, Rigoberto [Comision Federal de Electricidad, Gerencia de Proyectos Geotermoelectricos, Morelia, Michoacan (Mexico)

2010-01-15

Isotopic data ({delta} 18 O, {delta} D) from fluids from production wells at the Los Humeros, Pue., geothermal field were analyzed to investigate the possible origin of these fluids and the dominant processes of the reservoir at its initial state. According to pre-exploitation data, it is suggested the Los Humeros reservoir fluids are made of a mixture of meteoric water of very light isotopic composition (paleo-fluids) and andesitic water. The relationship {delta} D vs {delta} 18 O from pre-exploitation data indicates the produced fluids are composed of a mixture of (at least) two fluids with distinct isotopic compositions. At the more enriched end of the mixing relationship are the isotopic compositions of the wells H-23 and H-18 (located in the southern area of the field), while the lighter fluids were found in well H-16 (originally) and then in well H-16 (repaired). It was found that the liquid phases of deep wells are more enriched in {delta} 18 O while the shallow wells present lower values, suggesting a convection process at the initial state. Based on this isotopic profile, it is considered that even the production depths of the wells H-1, H-12 and H-16 (repaired) are just about the same, but their respective isotopic compositions are quite different. The {delta} 18 O value for well H-16 (repaired) seems to be that of condensate steam, while the corresponding values for wells H-1 and H-12 fall within the value interval of the deep wells (H-23). This suggests wells H-1 and H-12 are collecting very deep fluids enriched in {delta} 18 O. These results could be useful in creating a conceptual model of the reservoir. [Spanish] Se analizaron datos isotopicos ({delta}18 O, {delta}D) de los fluidos de pozos productores del campo geotermico de Los Humeros, Pue., para investigar el posible origen de los fluidos asi como los procesos dominantes del yacimiento en su estado inicial. De acuerdo con datos previos a la explotacion, se plantea que los fluidos del yacimiento

QCD in the {delta}-regime

Energy Technology Data Exchange (ETDEWEB)

Bietenholz, W. [Universidad Nacional Autonoma de Mexico, Mexico City (Mexico). Inst. de Ciencias Nucleares; Cundy, N. [Seoul National Univ. (Korea, Republic of). Lattice Gauge Theory Research Center; Goeckeler, M. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Horsley, R.; Zanotti, J.M. [Edinburgh Univ. (United Kingdom). School of Physics; Nakamura, Y. [Tsukuba Univ., Ibaraki (Japan). Center for Computational Sciences; Pleiter, D. [Deutsches Elektronen-Synchrotron (DESY), Zeuthen (Germany); Rakow, P.E.L. [Liverpool Univ. (United Kingdom). Theoretical Physics Div.; Schierholz, G. [Regensburg Univ. (Germany). Inst. fuer Theoretische Physik; Deutsches Elektronen-Synchrotron (DESY), Hamburg (Germany)

2011-03-15

The {delta}-regime of QCD is characterised by light quarks in a small spatial box, but a large extent in (Euclidean) time. In this setting a specific variant of chiral perturbation theory - the {delta}-expansion - applies, based on a quantum mechanical treatment of the quasi onedimensional system. In particular, for vanishing quark masses one obtains a residual pion mass M{sup R}{sub {pi}}, which has been computed to the third order in the {delta}-expansion. A comparison with numerical measurements of this residual mass allows for a new determination of some Low Energy Constants, which appear in the chiral Lagrangian. We first review the attempts to simulate 2-flavour QCD directly in the {delta}-regime. This is very tedious, but results compatible with the predictions for M{sup R}{sub {pi}} have been obtained. Then we show that an extrapolation of pion masses measured in a larger volume towards the {delta}-regime leads to good agreement with the theoretical predictions. From those results, we also extract a value for the (controversial) sub-leading Low Energy Constant anti l{sub 3}. (orig.)

Effects of {Delta}-isobar degrees of freedom on the reactions {sup 3}He(n,{gamma}){sup 4}He and {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He at low-energy

Energy Technology Data Exchange (ETDEWEB)

Schiavilla, R.

1991-12-31

The cross sections of the radiative {sup 3}He(n,{gamma}){sup 4}He and weak {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and {Delta}-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + {Delta} Hilbert space.

Effects of. Delta. -isobar degrees of freedom on the reactions sup 3 He(n,. gamma. ) sup 4 He and sup 3 He(p,e sup +. nu. sub e ) sup 4 He at low-energy

Energy Technology Data Exchange (ETDEWEB)

Schiavilla, R.

1991-01-01

The cross sections of the radiative {sup 3}He(n,{gamma}){sup 4}He and weak {sup 3}He(p,e{sup +}{nu}{sub e}){sup 4}He capture reactions at thermal neutron and keV proton energies have been calculated with the Variational Monte Carlo method. The ground state and low-energy continuum wave functions have been determined variationally from a realistic Hamiltonian, and include both nucleon and {Delta}-isobar degrees of freedom. The electroweak transition operator contains one- and two-body components in the N + {Delta} Hilbert space.

Improved γ-linolenic acid production in Mucor circinelloides by homologous overexpressing of delta-12 and delta-6 desaturases.

Science.gov (United States)

Zhang, Yao; Luan, Xiao; Zhang, Huaiyuan; Garre, Victoriano; Song, Yuanda; Ratledge, Colin

2017-06-21

γ-Linolenic acid (GLA) is important because of its nutritional value and medicinal applications. Although the biosynthetic pathways of some plant and microbial GLA have been deciphered, current understanding of the correlation between desaturases and GLA synthesis in oleaginous fungi is incomplete. In previous work, we found that a large amount of oleic acid (OA) had not been converted to linoleic acid (LA) or GLA in Mucor circinelloides CBS 277.49, which may be due to inadequate activities of the delta-12 or delta-6 desaturases, and thus leading to the accumulation of OA and LA. Thus, it is necessary to explore the main contributing factor during the process of GLA biosynthesis in M. circinelloides. To enhance GLA production in M. circinelloides, homologous overexpression of delta-12 and two delta-6 desaturases (named delta-6-1 and delta-6-2, respectively) were analyzed. When delta-6 desaturase were overexpressed in M. circinelloides, up to 43% GLA was produced in the total fatty acids, and the yield of GLA reached 180 mg/l, which were, respectively, 38 and 33% higher than the control strain. These findings revealed that delta-6 desaturase (especially for delta-6-1 desaturase) plays an important role in GLA synthesis by M. circinelloides. The strain overexpressing delta-6-1 desaturase may have potential application in microbial GLA production.

Investigation at transonic speeds of the lateral-control and hinge-moment characteristics of a flap-type spoiler aileron on a 60 degree delta wing

Science.gov (United States)

Wiley, Harleth G; Taylor, Robert T

1954-01-01

This paper present results of an investigation of the lateral-control and hinge-moment characteristics of a 0.67 semispan flap-type spoiler aileron on a semispan thin 60 degree delta wing at transonic speeds by the reflection-plane technique. The spoiler-aileron had a constant chord of 10.29 percent mean aerodynamic chord and was hinged at the 81.9-percent-wing-root-chord station. Tests were made with the spoiler aileron slot open, partially closed, and closed. Incremental rolling-moment coefficients were obtained through a Mach number range of 0.62 to 1.08. Results indicated reasonably linear variations of rolling-moment and hinge-moment coefficients with spoiler projection except at spoiler projections of less than -2 percent mean aerodynamic chord and angles of attack greater than 12 degrees with results generally independent of slot geometry.

The Localizing Value Of Focal Delta Slowing In Temporal Lobe ...

African Journals Online (AJOL)

Slow wave EEG had a higher marginal probability than neuropsychological assessment of predicting the focus, and was equally effective as other investigative methods. Conclusion These results suggest that focal temporal delta slowing is useful in the localization of epileptogenic foci. There was no discordance with the ...

Antinociceptive activity of Delta9-tetrahydrocannabinol non-ionic microemulsions.

Science.gov (United States)

Lazzari, P; Fadda, P; Marchese, G; Casu, G L; Pani, L

2010-06-30

Delta(9)-Tetrahydrocannabinol (Delta(9)-THC), the major psychoactive constituent of Cannabis sativa L., has been widely studied for its potential pharmaceutical application in the treatment of various diseases and disturbs. This sparingly soluble terpeno-phenolic compound is not easy to handle and to be formulated in pharmaceutical preparations. The aim of this work was to develop a stable aqueous Delta(9)-THC formulation acceptable for different ways of administration, and to evaluate the therapeutic properties of the new Delta(9)-THC based preparation for pain treatment. Due to the thermodynamic stability and advantages of microemulsion based systems, the study was focused on the identification of aqueous microemulsion based systems containing Delta(9)-THC. Oil in water Delta(9)-THC microemulsions were individuated through phase diagrams construction, using the non-ionic surfactant Solutol HS15, being this surfactant acceptable for parenteral administration in human. A selected microemulsion samples containing 0.2 wt% of Delta(9)-THC, stable up to 52 degrees C, was successfully assayed on animal models of pain. Significant antinociceptive activity has been detected by both intraperitoneal and intragastric administration of the new Delta(9)-THC pharmaceutical preparation. The effect has been highlighted in shorter time if compared to a preparation of the same active principle based on previously reported conventional preparation. 2010 Elsevier B.V. All rights reserved.

Measurement of the delta34S value in methionine by double spike multi-collector thermal ionization mass spectrometry using Carius tube digestion.

Science.gov (United States)

Mann, Jacqueline L; Kelly, W Robert

2010-09-15

Methionine is an essential amino acid and is the primary source of sulfur for humans. Using the double spike ((33)S-(36)S) multi-collector thermal ionization mass spectrometry (MC-TIMS) technique, three sample bottles of a methionine material obtained from the Institute for Reference Materials and Measurements have been measured for delta(34)S and sulfur concentration. The mean delta(34)S value, relative to Vienna Canyon Diablo Troilite (VCDT), determined was 10.34 +/- 0.11 per thousand (n = 9) with the uncertainty reported as expanded uncertainties (U). These delta(34)S measurements include a correction for blank which has been previously ignored in studies of sulfur isotopic composition. The sulfur concentrations for the three bottles range from 56 to 88 microg/g. The isotope composition and concentration results demonstrate the high accuracy and precision of the DS-MC-TIMS technique for measuring sulfur in methionine.

Systematics of ground state multiplets of atomic nuclei in the delta-interaction approach

Energy Technology Data Exchange (ETDEWEB)

Imasheva, L. T.; Ishkhanov, B. S.; Stepanov, M. E., E-mail: stepanov@depni.sinp.msu.ru [Moscow State University, Faculty of Physics (Russian Federation); Tretyakova, T. Yu. [Moscow State University, Skobeltsyn Institute of Nuclear Physics (Russian Federation)

2015-12-15

Pairing forces between nucleons in an atomic nucleus strongly influence its structure. One of the manifestations of pair interaction is the ground state multiplet (GSM) formation in the spectrum of low-lying excited states of even–even nuclei. The value of GSM splitting is determined by the value of pair interaction of nucleons; for each isotope, it can be estimated on the basis of experimental nuclear masses. The quality of this estimate is characterized by the degree of reproduction of GSM levels in the nucleus. The GSM systematics in even–even nuclei with a pair of identical nucleons in addition to the filled nuclear core is considered on the basis of delta interaction.

Stable Isotope (delta OXYGEN-18, Delta Deuterium, Delta CARBON-13) Dendroclimatological Studies in the Waterloo Region of Southern Ontario, Canada, Between AD 1610 and 1990.

Science.gov (United States)

Buhay, William Mark

Oxygen (delta^{18} O), hydrogen (delta^2H) and carbon (delta^{13}C) isotopes were measured in wood cellulose from elm, white pine and maple trees that grew in southwestern Ontario, Canada. The measured oxygen and hydrogen isotopic data were used for model-based reconstructions of delta^{18}{O}_{meteoric water}, mean annual temperature (MAT) and relative humidity for a period, AD 1610 to 1880, that precedes instrumental records of climate. The carbon isotope measurements were compared with the Cellulose Model inferred climate data to reveal additional environmental information. Modifications made to the Cellulose Model focused on the dynamics of oxygen and hydrogen isotopic fractionation in plants during evapotranspiration and photosynthetic assimilation. For instance, kinetic fractionation of ^{18}O was found to be predictable from theoretical considerations of leaf energy balance and boundary layer dynamics. Kinetic fractionation during evapotranspiration is sensitive to the nature of the boundary layer, which is controlled by leaf size and morphology. Generally, plants with small segmented leaves have a lower component of turbidity in the leaf boundary layer, which results in higher kinetic fractionation values, than do plants having large simple leaves and more turbulent boundary layers. Kinetic ^2H enrichment in plant leaf water can also be rationalized in terms of leaf size and morphology when an apparent temperature-dependent isotope effect, acting in opposition to evaporative enrichment, is taken into account. Accounting for this temperature -dependent isotope effect helps to: (1) reconcile hydrogen kinetic fractionation inconsistencies for different leaves; (2) explain a temperature effect previously attributed to variable biochemical fractionation during cellulose synthesis, and; (3) verify hydrogen biochemical effects in plants. This improved characterization of the oxygen and hydrogen isotopic effects in plants, using the modified Cellulose Model, helped

Average of delta: a new quality control tool for clinical laboratories.

Science.gov (United States)

Jones, Graham R D

2016-01-01

Average of normals is a tool used to control assay performance using the average of a series of results from patients' samples. Delta checking is a process of identifying errors in individual patient results by reviewing the difference from previous results of the same patient. This paper introduces a novel alternate approach, average of delta, which combines these concepts to use the average of a number of sequential delta values to identify changes in assay performance. Models for average of delta and average of normals were developed in a spreadsheet application. The model assessed the expected scatter of average of delta and average of normals functions and the effect of assay bias for different values of analytical imprecision and within- and between-subject biological variation and the number of samples included in the calculations. The final assessment was the number of patients' samples required to identify an added bias with 90% certainty. The model demonstrated that with larger numbers of delta values, the average of delta function was tighter (lower coefficient of variation). The optimal number of samples for bias detection with average of delta was likely to be between 5 and 20 for most settings and that average of delta outperformed average of normals when the within-subject biological variation was small relative to the between-subject variation. Average of delta provides a possible additional assay quality control tool which theoretical modelling predicts may be more valuable than average of normals for analytes where the group biological variation is wide compared with within-subject variation and where there is a high rate of repeat testing in the laboratory patient population. © The Author(s) 2015.

Collaborative Innovation Research on High-tech Industry in the Center Delta

Directory of Open Access Journals (Sweden)

Yan Jingdong

2017-01-01

Full Text Available As a strong point in the Middle Rises Strategy, the Center Delta is of great significance to high-tech industry development. While the collaborative innovation is an effective way to promote the coordinated development of regional economy. This article selected electronic and communication equipment manufacturing industry of 3 provinces in the Center Delta as samples, built evaluation index system of collaborative innovation of high-tech industry, and put the relevant data into the system coordination degree model, in order to get the synergy of industrial innovation system and innovation environment system of 3 provinces. The empirical results shown that the industrial innovation system and innovation environment system coordination degree of Hubei province was the highest, while Jiangxi province was the lowest. Based on the empirical result analysis of the above-mentioned systems, this article put forward suggestions to promote the development of the high-tech industry collaborative innovation in the Center Delta.

The dynamics of central Main Ethiopian Rift waters: Evidence from {delta}D, {delta}{sup 18}O and {sup 87}Sr/{sup 86}Sr ratios

Energy Technology Data Exchange (ETDEWEB)

Rango, Tewodros, E-mail: tewodros.godebo@duke.edu [Division of Earth and Ocean Sciences, Nicholas School of the Environment, Duke University, Durham, NC 27708 (United States)] [Addis Ababa University, Department of Earth Sciences, P.O. Box 1176, Addis Ababa (Ethiopia); Petrini, Riccardo; Stenni, Barbara [University of Trieste, Department of Geosciences, Via Weiss 1, I-34100 Trieste (Italy); Bianchini, Gianluca [Istituto di Geoscienze e Georisorse-CNR, Pisa (Italy)] [Department of Earth Sciences, University of Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Slejko, Francesca [University of Trieste, Department of Geosciences, Via Weiss 1, I-34100 Trieste (Italy); Beccaluva, Luigi [Department of Earth Sciences, University of Ferrara, Via Saragat 1, 44100 Ferrara (Italy); Ayenew, Tenalem [Addis Ababa University, Department of Earth Sciences, P.O. Box 1176, Addis Ababa (Ethiopia)

2010-12-15

Research highlights: {yields} Chemical and isotope ({delta}D, {delta}{sup 18}O and {sup 87}Sr/{sup 86}Sr) techniques are applied to understand various hydrological processes in the Main Ethiopian Rift. {yields} Some of the studied groundwaters display a depleted {delta}D-{delta}{sup 18}O composition when compared to the present-day average precipitation, thus suggesting that the rift floor aquifers also contains paleo-meteoric waters recharge associated with deep flow system. {yields} The pristine waters coming from the highlands display isotopic compositions characterized by less radiogenic {sup 87}Sr/{sup 86}Sr (and more depleted {delta}D, {delta}{sup 18}O). This isotopic signature subsequently evolves towards higher {sup 87}Sr/{sup 86}Sr by an interaction with the more radiogenic rhyolites of the rift and their weathered and redeposited products. - Abstract: Water samples from cold and geothermal boreholes, hot springs, lakes and rivers were analyzed for {delta}D, {delta}{sup 18}O and {sup 87}Sr/{sup 86}Sr compositions in order to investigate lake water-groundwater mixing processes, water-rock interactions, and to evaluate groundwater flow paths in the central Main Ethiopian Rift (MER) of the Ziway-Shala basin. Different ranges of isotopic values were recorded for different water types: hot springs show {delta}{sup 18}O -3.36 to +3.69 and {delta}D -15.85 to +24.23, deep Aluto-Langano geothermal wells show {delta}{sup 18}O -4.65 to -1.24 and {delta}D -12.39 to -9.31, groundwater wells show {delta}{sup 18}O -3.99 to +5.14 and {delta}D -19.69 to +32.27, whereas the lakes show {delta}{sup 18}O and {delta}D in the range +3.98 to +7.92 and +26.19 to +45.71, respectively. The intersection of the Local Meteoric Water Line (LMWL: {delta}D = 7 {delta}{sup 18}O + 11.2, R{sup 2} = 0.94, n = 42) and the Local Evaporation Line (LEL: {delta}D = 5.63{delta}{sup 18}O + 8, n = 14, R{sup 2} = 0.82) was used to estimate the average isotopic composition of recharge water into the

Exploring the Value of MBA Degrees: Students' Experiences in Full-Time, Part-Time, and Executive MBA Programs

Science.gov (United States)

Bruce, Grady D.

2010-01-01

Critics of the overall value of the MBA have not systematically considered the attitudes of MBA students about the value of their degree. The author used data from a large sample of graduates (N = 16,268) to do so, and to explore predictors of overall degree value. The author developed separate regression models for full-time, part-time, and…

Cryostratigraphy, sedimentology, and the late Quaternary evolution of the Zackenberg River delta, northeast Greenland

DEFF Research Database (Denmark)

Gilbert, Graham L.; Cable, Stefanie; Thiel, Christine

2017-01-01

The Zackenberg River delta is located in northeast Greenland (74 degrees 30' N, 20 degrees 30' E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated the depo......The Zackenberg River delta is located in northeast Greenland (74 degrees 30' N, 20 degrees 30' E) at the outlet of the Zackenberg fjord valley. The fjord-valley fill consists of a series of terraced deltaic deposits (ca. 2 km2) formed during relative sea-level (RSL) fall. We investigated...... the deposits using sedimentological and cryostratigraphic techniques together with optically stimulated luminescence (OSL) dating. We identify four facies associations in sections (4 to 22 m in height) exposed along the modern Zackenberg River and coast. Facies associations relate to (I) overriding glaciers......, (II) retreating glaciers and quiescent glaciomarine conditions, (III) delta progradation in a fjord valley, and (IV) fluvial activity and niveo-aeolian processes. Pore, layered, and suspended cryofacies are identified in two 20 m deep ice-bonded sediment cores. The cryofacies distribution, together...

D2 Delta Robot Structural Design and Kinematics Analysis

Science.gov (United States)

Yang, Xudong; wang, Song; Dong, Yu; Yang, Hai

2017-12-01

In this paper, a new type of Delta robot with only two degrees of freedom is proposed on the basis of multi - degree - of - freedom delta robot. In order to meet our application requirements, we have carried out structural design and analysis of the robot. Through SolidWorks modeling, combined with 3D printing technology to determine the final robot structure. In order to achieve the precise control of the robot, the kinematics analysis of the robot was carried out. The SimMechanics toolbox of MATLAB is used to establish the mechanism model, and the kinematics mathematical model is used to simulate the robot motion control in Matlab environment. Finally, according to the design mechanism, the working space of the robot is drawn by the graphic method, which lays the foundation for the motion control of the subsequent robot.

Co-Articulating the Value of a Liberal Arts Degree with Students

Science.gov (United States)

Cushing, Pamela

2012-01-01

While most scholars and higher education professionals believe in the intrinsic value of a liberal arts degree, high school students and their parents often have a different bias as they seek to determine where to invest themselves and their resources. Anyone who has taught in or recruited for the social sciences or humanities will recognize the…

Controls of {delta}{sup 34}S and {delta}{sup 18}O in dissolved sulphate: Learning from a detailed survey in the Llobregat River (Spain)

Energy Technology Data Exchange (ETDEWEB)

Otero, Neus [Departament Cristal . lografia, Mineralogia i Diposits Minerals, Facultat de Geologia, Universitat de Barcelona, Marti i Franques, s/n, 08028 Barcelona (Spain); Grup d' Hidrogeoquimica, Departament de Geologia Ambiental, Institut de Ciencies de la Terra ' Jaume Almera' , CSIC, Lluis Sole i Sabaris, s/n, 08028 Barcelona (Spain)], E-mail: notero@ub.edu; Soler, Albert; Canals, Angels [Departament Cristal . lografia, Mineralogia i Diposits Minerals, Facultat de Geologia, Universitat de Barcelona, Marti i Franques, s/n, 08028 Barcelona (Spain)

2008-05-15

The S and O isotopic composition of dissolved SO{sub 4}, used as a tracer for SO{sub 4} sources, was applied to the water of the Llobregat River system (NE Spain). The survey was carried out at 30 sites where surface water was sampled on a monthly basis over a period of 2a. The concentration of dissolved SO{sub 4} varied from 20 to 1575 mg L{sup -1}. Sulphur isotopic compositions clustered in two populations: one - 93% of the samples - had positive values with a mode of +9 per mille ; the other had negative values and a mode of -5 per mille . Data for {delta}{sup 18}O{sub SO{sub 4}} showed a mean value of +11 per mille , with no bi-modal distribution, though lower values of {delta}{sup 18}O corresponded to samples with negative {delta}{sup 34}S. These values can not be explained solely by the contribution of bedrock SO{sub 4} sources: that is, sulphide oxidation and the weathering of outcrops of sulphates, though numerous chemical sediments exist in the basin. Even in a river with a high concentration of natural sources of dissolved SO{sub 4}, such as the Llobregat River, the {delta}{sup 34}S values suggest that dissolved SO{sub 4} is controlled by a complex mix of both natural and anthropogenic sources. The main anthropogenic sources in this basin are fertilizers, sewage, potash mine effluent and power plant emissions. Detailed river water sampling, together with the chemical and isotopic characterisation of the main anthropogenic inputs, allowed determination of the influence of redox processes, as well as identification of the contribution of natural and anthropogenic SO{sub 4} sources and detection of spatial variations and seasonal changes among these sources. For instance, in the Llobregat River the input of fertilisers is well marked seasonally. Minimum values of {delta}{sup 34}S are reported during fertilization periods - from January to March - indicating a higher contribution of this source. The dual isotope approach, {delta}{sup 34}S and {delta}{sup 18}O

THE VALUE OF EDUCATIONAL DEGREES IN TURBULENT ECONOMIC TIMES: EVIDENCE FROM THE YOUTH DEVELOPMENT STUDY

Science.gov (United States)

Mortimer, Jeylan T.; Staff, Jeremy

2016-01-01

Rising costs of higher education have prompted debate about the value of college degrees. Using mixed effects panel models of data from the Youth Development Study (ages 31–37), we compare occupational outcomes (i.e., weekly hours worked, earnings, employment status, career attainment, and job security) between educational attainment categories within year, and within categories across years, from 2005 to 2011, capturing the period before, during, and in the aftermath of the Great Recession. Our findings demonstrate the long-term value of post-secondary degrees. Bachelor’s and Associate’s degree recipients, while experiencing setbacks at the height of recession, were significantly better off than those with some or no college attendance. Vocational-Technical degree holders followed a unique trajectory: pre-recession, they are mostly on par with Associate’s and Bachelor’s recipients, but they are hit particularly hard by the recession and then rebound somewhat afterwards. Our findings highlight the perils of starting but not finishing post-secondary educational programs. PMID:26973042

The value of educational degrees in turbulent economic times: Evidence from the Youth Development Study.

Science.gov (United States)

Vuolo, Mike; Mortimer, Jeylan T; Staff, Jeremy

2016-05-01

Rising costs of higher education have prompted debate about the value of college degrees. Using mixed effects panel models of data from the Youth Development Study (ages 31-37), we compare occupational outcomes (i.e., weekly hours worked, earnings, employment status, career attainment, and job security) between educational attainment categories within year, and within categories across years, from 2005 to 2011, capturing the period before, during, and in the aftermath of the Great Recession. Our findings demonstrate the long-term value of post-secondary degrees. Bachelor's and Associate's degree recipients, while experiencing setbacks at the height of recession, were significantly better off than those with some or no college attendance. Vocational-Technical degree holders followed a unique trajectory: pre-recession, they are mostly on par with Associate's and Bachelor's recipients, but they are hit particularly hard by the recession and then rebound somewhat afterwards. Our findings highlight the perils of starting but not finishing post-secondary educational programs. Copyright © 2016 Elsevier Inc. All rights reserved.

Diet-tissue stable isotope (delta¹³C and delta¹⁵N) discrimination factors for multiple tissues from terrestrial reptiles (rock iguanas, Cyclura species)

OpenAIRE

Steinitz, Ronnie

2015-01-01

Trophic interactions can drive community structure; therefore, studying food webs is key in understanding ecological communities. Stable isotope analysis is a powerful tool for reconstructing foraging patterns. However, stable isotope discrimination factors (delta¹³C and delta¹⁵N) are needed to best use this tool. We determined the first delta¹³C and delta¹⁵N values for Rock Iguanas (Cyclura spp.) to better understand isotope fractionation patterns in reptiles and estimate wild reptile diets....

Degree of value alignment - a grounded theory of rural nurse resignations.

Science.gov (United States)

Bragg, S M; Bonner, A

2014-01-01

The shortage of nurses willing to work in rural Australian healthcare settings continues to worsen. Australian rural areas have a lower retention rate of nurses than metropolitan counterparts, with more remote communities experiencing an even higher turnover of nursing staff. When retention rates are lower, patient outcomes are known to be poorer. This article reports a study that sought to explore the reasons why registered nurses resign from rural hospitals in the state of New South Wales, Australia. Using grounded theory methods, this study explored the reasons why registered nurses resigned from New South Wales rural hospitals. Data were collected from 12 participants using semi-structured interviews; each participant was a registered nurse who had resigned from a rural hospital. Nurses who had resigned due to retirement, relocation or maternity leave were excluded. Interviews were transcribed verbatim and imported into NVivo software. The constant comparative method of data collection and analysis was followed until a core category emerged. Nurses resigned from rural hospitals when their personal value of how nursing should occur conflicted with the hospital's organisational values driving the practice of nursing. These conflicting values led to a change in the degree of value alignment between the nurse and hospital. The degree of value alignment occurred in three dynamic stages that nurses moved through prior to resigning. The first stage, sharing values, was a time when a nurse and a hospital shared similar values. The second stage was conceding values where, due to perceived changes in a hospital's values, a nurse felt that patient care became compromised and this led to a divergence of values. The final stage was resigning, a stage where a nurse 'gave up' as they felt that their professional integrity was severely compromised. The findings revealed that when a nurse and organisational values were not aligned, conflict was created for a nurse about how

Haematological and genetic features of delta beta-thalassaemia in Pakistan

International Nuclear Information System (INIS)

Ahmad, S.; Anwar, M.

2006-01-01

Objective: To describe the hematological and genetic features of delta beta-thalassaemia in Pakistani patients. Design: Descriptive case series. Place and Duration of Study: Department of Pathology, PNS Shifa, Karachi and Department of Hematology, Armed Forces Institute of Pathology, Rawalpindi, from January 1994 to April 2004. Patients and Methods: Thirteen individuals from six unrelated Pakistani families with a hematological diagnosis of delta beta-thalassaemia were studied. A brief clinical history, and the results of blood counts, absolute values, Hb-F, Hb-A/sub 2/, and hemoglobin electrophoresis were recorded. The DNA from each subject was first screened for the delta beta-thalassaemia mutations found in the Pakistani population. The samples were then screened for the Invl Del sup G/gamma(sup A/gamma delta beta). Results: The subjects included six heterozygote, six homozygotes and one compound heterozygote of delta beta and delta beta-thalassaemia. All heterozygote and 4/6 homozygotes were asymptomatic. One homo zygote had thalassaemia intermedia while another had transfusion dependent anemia. The mean Hb, TRBC, MCV, MCH, Hb-F and Hb-A/sub 2/ in delta beta-thalassaemia heterozygote were 11.6 g/dl, 5.37 x 1012/L, 70.9 fl, and 21.7 pg, 14% and 2.6% respectively. The same values in the four un transfused homo zygote were 10.6 g/dl, 5.34x1012/L, 69.211, and 20.8pg, 100% and 0% respectively. The mutation analysis revealed that all 13 individuals had the same Invl Del sup G/gamma(sup A/gamma delta beta). Conclusion: delta beta-thalassaemia is a rare disorder in Pakistan. Although the clinical picture is very mild its combination with delta beta-thalassaemia trait can produce a sever transfusion dependent thalassaemia. The DNA based diagnosis is possible in the prenatal as well as the postnatal period. (author)

Cartilage quality in rheumatoid arthritis: comparison of T2* mapping, native T1 mapping, dGEMRIC, {delta}R1 and value of pre-contrast imaging

Energy Technology Data Exchange (ETDEWEB)

Buchbender, Christian; Scherer, Axel; Kroepil, Patric; Quentin, Michael; Reichelt, Dorothea C.; Lanzman, Rotem S.; Mathys, Christian; Blondin, Dirk; Wittsack, Hans-Joerg; Antoch, Gerald; Miese, Falk [University Duesseldorf, Department of Diagnostic and Interventional Radiology, Medical Faculty, Duesseldorf (Germany); Koerbl, Birthe [Heinrich-Heine-University, Department of Endocrinology, Diabetology and Rheumatology, Medical Faculty, Duesseldorf (Germany); Heinrich-Heine-University, Leibniz Centre for Diabetes Research, Institute of Biometrics and Epidemiology, German Diabetes Centre, Duesseldorf (Germany); Bittersohl, Bernd; Zilkens, Christoph [Heinrich-Heine-University, Department of Orthopaedics, Medical Faculty, Duesseldorf (Germany); Hofer, Matthias [Heinrich-Heine-University, Medical Education Group, Medical School, Duesseldorf (Germany); Schneider, Matthias; Ostendorf, Benedikt [Heinrich-Heine-University, Department of Endocrinology, Diabetology and Rheumatology, Medical Faculty, Duesseldorf (Germany)

2012-06-15

To prospectively evaluate four non-invasive markers of cartilage quality - T2* mapping, native T1 mapping, dGEMRIC and {delta}R1 - in healthy volunteers and rheumatoid arthritis (RA) patients. Cartilage of metacarpophalangeal (MCP) joints II were imaged in 28 consecutive subjects: 12 healthy volunteers [9 women, mean (SD) age 52.67 (9.75) years, range 30-66] and 16 RA patients with MCP II involvement [12 women, mean (SD) age 58.06 (12.88) years, range 35-76]. Sagittal T2* mapping was performed with a multi-echo gradient-echo on a 3 T MRI scanner. For T1 mapping the dual flip angle method was applied prior to native T1 mapping and 40 min after gadolinium application (delayed gadolinium-enhanced MRI of cartilage, dGEMRIC, T1{sub Gd}). The difference in the longitudinal relaxation rate induced by gadolinium ({delta}R1) was calculated. The area under the receiver operating characteristic curve (AROC) was used to test for differentiation of RA patients from healthy volunteers. dGEMRIC (AUC 0.81) and {delta}R1 (AUC 0.75) significantly differentiated RA patients from controls. T2* mapping (AUC 0.66) and native T1 mapping (AUC 0.66) were not significantly different in RA patients compared to controls. The data support the use of dGEMRIC for the assessment of MCP joint cartilage quality in RA. T2* and native T1 mapping are of low diagnostic value. Pre-contrast T1 mapping for the calculation of {delta}R1 does not increase the diagnostic value of dGEMRIC. (orig.)

Unexpected {delta}{sup 18}O and {delta}{sup 2}H Variability of Groundwater in the Eastern Paris Basin

Energy Technology Data Exchange (ETDEWEB)

Gourcy, L.; Petelet-Giraud, E. [BRGM Service EAU, Orleans (France)

2013-07-15

The Paris Basin covers about one-third of the total surface area of France. In 2009, two campaigns sampling 25 boreholes tapping Tertiary aquifers were carried out in the Basin. These aquifers are recharged at a similar altitude and the groundwater age is too young to have registered climate change. In the past, regional studies included the use of isotopes to understand groundwater origin and dynamics. Both {delta}{sup 18}O and {delta}{sup 2}H as well as ages (CFC/SF{sub 6)} and chemical components were determined in all collected samples. A noticeable stable isotope 'anomaly' appears in the south-western part of the Basin, where the average {delta}{sup 18}O and {delta}{sup 2}H values are more depleted and do not fit the pattern given by the continental effect in this area. A regional particularity of the spatial distribution of such isotopes in precipitation may be possible, but should be confirmed by additional work. (author)

Determination of the PO2 temperature blood factor from oxygen dissociation curves.

Science.gov (United States)

Hérigault, R A; Soulard, C D; Teisseire, B P; Laurent, D N

1983-01-01

The variation with saturation of the temperature coefficient of PO2 in human blood (delta log PO2/delta T) was determined by continuous recording of the oxygen dissociation curve (ODC), at 37 degrees C and 25 degrees C, on the same blood samples. PCO2 and pH were held constant through an ODC run, and PCO2 was reduced at 25 degrees C to the value measured by anaerobic cooling of the same sample. delta log PO2/delta T was calculated from isosaturation points on the 37 and 25 degrees C curves. The temperature coefficient was also computed as an independent check on this method by determination of the effects of temperature (25, 30, 37 and 40 degrees C) on hemoglobin ligand interaction: fixed acid Bohr effect (delta log PO2/delta pH), carbamino-formation (delta log PO2/delta log PCO2) and hemoglobin oxygen affinity. The values of delta log PO2/delta T ratio obtained from the two different approaches were found to be in good agreement. The coefficient decreased when [H+] concentration was increased. A linear relationship between the Bohr factor and the temperature was found: delta log PO2/delta pH = 0.00267 T-0.520 (r = 0.85; n = 40) At 25 degrees C, the carbamino-formation was one order of magnitude lower than at 37 degrees C. Acid-base state and saturation value appeared to be major determinant factors for the temperature correction coefficient to be applied to blood PO2 values measured at standard (37 degrees C) temperature.

Delta-nucleus dynamics: proceedings of symposium

International Nuclear Information System (INIS)

Lee, T.S.H.; Geesaman, D.F.; Schiffer, J.P.

1983-10-01

The appreciation of the role in nuclear physics of the first excited state of the nucleon, the delta Δ(1232), has grown rapidly in the past decade. The delta resonance dominates nuclear reactions induced by intermediate energy pions, nucleons, and electromagnetic probes. It is also the most important non-nucleonic degree of freedom needed to resolve many fundamental problems encountered in the study of low-energy nuclear phenomena. Clearly, a new phase of nuclear physics has emerged and conventional thinking must be extended to account for this new dimension of nuclear dynamics. The most challenging problem we are facing is how a unified theory can be developed to describe Δ-nucleus dynamics at all energies. In exploring this new direction, it is important to have direct discussions among researchers with different viewpoints. Separate entries were prepared for the 49 papers presented

Challenges, Approaches and Experiences from Asian Deltas and the Rhine-Meuse Delta : Regional Training Workshop on Delta Planning and Management

NARCIS (Netherlands)

Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

2013-01-01

River delta's, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Ayeyarwady Delta (Myanmar), Nile (Egypt) and Ciliwung Delta (Indonesia) are developing rapidly and are characterised by large-scale urbanisation and industrialization processes. They are facing serious planning

Effects of recharge and discharge on delta2H and delta18O composition and chloride concentration of high arsenic/fluoride groundwater from the Datong Basin, northern China.

Science.gov (United States)

Xie, Xianjun; Wang, Yanxin; Su, Chunli; Duan, Mengyu

2013-02-01

To better understand the effects of recharge and discharge on the hydrogeochemistry of high levels of arsenic (As) and fluoride (F) in groundwater, environmental isotopic composition (delta2H and delta18O) and chloride (Cl) concentrations were analyzed in 29 groundwater samples collected from the Datong Basin. High arsenic groundwater samples (As > 50 micog/L) were found to be enriched in lighter isotopic composition that ranged from -92 to -78 per thousand for deuterium (delta2H) and from -12.5 to -9.9 per thousand for oxygen-18 (delta18O). High F-containing groundwater (F > 1 mg/L) was relatively enriched in heavier isotopic composition and varied from -90 to -57 per thousand and from -12.2 to -6.7 per thousand for delta2H and delta18O, respectively. High chloride concentrations and delta18O values were primarily measured in groundwater samples from the northern and southwestern portions of the study area, indicating the effect of evaporation on groundwater. The observation of relatively homogenized and low delta18O values and chloride concentrations in groundwater samples from central part of the Datong Basin might be a result of fast recharge by irrigation returns, which suggests that irrigation using arsenic-contaminated groundwater affected the occurrence of high arsenic-containing groundwater in the basin.

Maximizing the Value of 360-Degree Feedback: A Process for Successful Individual and Organizational Development.

Science.gov (United States)

Tornow, Walter W.; London, Manuel

Ways in which organizations can enhance their use of "360-degree feedback" are presented. The book begins with a review of the process itself, emphasizing that 360-degree feedback should be a core element of self-development. The book is divided into three parts. Part 1 describes how to maximize the value of the process for individual…

THE RURAL TOURISM IN DANUBE DELTA

Directory of Open Access Journals (Sweden)

Ionica SOARE

2014-06-01

Full Text Available Purpose - the purpose of this paper is to evaluate the rural areas has market size and forecast its development as an economic activity. The present paper aims at analyzing the rural areas has in Danube Delta. In an enviable BAs which have responsibility for their particular isolated, such as the Danube Delta and the Danube that used, fishing and rural areas has the main activities that provide jobs and income sources for local populations. Design/methodology/approach - A survey was administered to customers’ rural hostel accommodation in Danube Delta. Descriptive statistics method was mainly adopted to calculate the mean with standard deviation of entry assumes variable, and to examine the different levels of consumers' awareness. The index values of product familiarity, the ratio between entries assumes product's familiarity value and the average value. Findings - the research results show hash has rural consumers have different perception and accomplished through behaviour. The information channels of brand hash mainly from friends, relatives and neighbours, so word of mouth spreading is very important for a brand. Women show a higher sensitivity in health and are currently operating the propensity than referred to follow the recommendations for nutrition. Research limitations/implications - This item is intended to synthesize developments and challenges," on June 13th rural market growth has. The results of this paper should be considered tentatively until has also features replicated by larger has rural consumers. Originality/value - members of rural areas has consumer's behavior would improve marketing and the development of rural areas has products, in order to reduce consumer confusion.

Delta Plaza kohvik = Delta Plaza cafe

Index Scriptorium Estoniae

2010-01-01

Tallinnas Pärnu mnt 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Tiiu Truusi tähtsamate tööde loetelu. Büroohoone Delta Plaza arhitektid Marika Lõoke ja Jüri Okas (AB J. Okas & M. Lõoke)

Navier-Stokes prediction of a delta wing in roll with vortex breakdown

Science.gov (United States)

Chaderjian, Neal M.; Schiff, Lewis B.

1993-01-01

The three-dimensional, Reynolds-averaged, Navier-Stokes (RANS) equations are used to numerically simulate vortical flow about a 65 degree sweep delta wing. Subsonic turbulent flow computations are presented for this delta wing at 30 degrees angle of attack and static roll angles up to 42 degrees. This work is part of an on going effort to validate the RANS approach for predicting high-incidence vortical flows, with the eventual application to wing rock. The flow is unsteady and includes spiral-type vortex breakdown. The breakdown positions, mean surface pressures, rolling moments, normal forces, and streamwise center-of-pressure locations compare reasonably well with experiment. In some cases, the primary vortex suction peaks are significantly underpredicted due to grid coarseness. Nevertheless, the computations are able to predict the same nonlinear variation of rolling moment with roll angle that appeared in the experiment. This nonlinearity includes regions of local static roll instability, which is attributed to vortex breakdown.

Isotopic variations ({delta}{sup 13} C and {delta}{sup 18} O) in Siderastrea stellata (Cnidaria-Anthozoa), Itamaraca island, State of Pernambuco, Northeastern Brazil

Energy Technology Data Exchange (ETDEWEB)

Ferreira, Valderez P.; Sial, Alcides N. [Pernambuco Univ., Recife, PE (Brazil). Dept. de Geologia. Lab. de Isotopos Estaveis; Mayeal, Elga M.; Exner, Marco Antonio [Pernambuco Univ., Recife, PE (Brazil). Dept. de Zoologia. Lab. de Macro e Megabentos

1998-12-01

Isotopic determinations for O and C were performed in coral skeletons collected in beach rocks from two localities (Orange and Catuama), Itamaraca Island, north littoral of the State of pernambuco, northeastern Brazil. Large variations of {delta}{sup 18} O and {delta}{sup 13} C in corals from both localities are found, the largest ones being observed at the Orange locality {delta}{sup 13} C in this locality varies from -0.8 to +1.8% PDB and {delta}{sup 1.8} O from -5.3 to -1.8% PDB, while at the Catuama locality, they vary from -1.8 to 0.1% PDB and -3.8 to -2.7% PDB, respectively. Large variations in {delta}{sup 18} O (up to 2.5%) coupled with weakly defined positive correlation between {delta}{sup 18} O and {delta}{sup 13} C, can be attributed to temperature variations as consequence of climatic perturbations. Temperature estimates, calculated from {delta}{sup 18} O values, assuming isotopic equilibrium with seawater, yield values between 24.9 deg C and 43.1 deg C at Orange, and from 28.4 deg C to 35 deg C at Catuama, all of them (expect one growth band from one sample) are high enough for the full development of the coral colony. Temperature average is 31.4 deg C at Orange, which is a little bit higher than that at Catuama, but both of them indicate thermal stress conditions. In all analyzed specimens, expect for one, at Orange, T increases was accompanied by decreasing in the organic activity, as suggested by corresponding negative {delta}{sup 13} C anomaly. Therefore, the observed bleaching is possibly related to thermal stress and the high T may be related to the El Nino-Southern Oscillation (ENSO) warning event. On the other hand, anthropogenic action at Orange, local of intense tourism throughout the year, coupled with high rate of sedimentation in the region, may contribute to the observed coral bleaching. (author)

The coastal system of the Volta delta, Ghana : Strategies and opportunities for development

NARCIS (Netherlands)

Roest, Lambertus W.M.

2018-01-01

The Volta delta is a very dynamic environment, forming the interface between the Volta river and the Atlantic ocean. The delta is a home for many communities, settled both at the shorelines and more inland. Furthermore the delta provides great natural values and a habitat for many species.
The

Growth laws for sub-delta crevasses in the Mississippi River Delta

Science.gov (United States)

Yocum, T. A.; Georgiou, I. Y.; Straub, K. M.

2017-12-01

River deltas are threatened by environmental change, including subsidence, global sea level rise, reduced sediment inputs and other local factors. In the Mississippi River Delta (MRD) these impacts are exemplified, and have led to proposed solutions to build land that include sediment diversions to reinitiate the delta cycle. Deltas were studied extensively using numerical models, theoretical and conceptual frameworks, empirical scaling relationships, laboratory models and field observations. But predicting the future of deltas relies on field observations where for most deltas data are still lacking. Moreover, empirical and theoretical scaling laws may be influenced by the data used to develop them, while laboratory deltas may be influenced by scaling issues. Anthropogenic crevasses in the MRD are large enough to overcome limitations of laboratory deltas, and small enough to allow for rapid channel and wetland development, providing an ideal setting to investigate delta development mechanics. Here we assessed growth laws of sub-delta crevasses (SDC) in the MRD, in two experimental laboratory deltas (LD - weakly and strongly cohesive) and compared them to river dominated deltas worldwide. Channel and delta geometry metrics for each system were obtained using geospatial tools, bathymetric datasets, sediment size, and hydrodynamic observations. Results show that SDC follow growth laws similar to large river dominated deltas, with the exception of some that exhibit anomalous behavior with respect to the frequency and distance to a bifurcation and the fraction of wetted delta shoreline (allometry metrics). Most SDC exhibit a systematic decrease of non-dimensional channel geometries with increased bifurcation order, indicating that channels are adjusting to decreased flow after bifurcations occur, and exhibit linear trends for land allometry and width-depth ratio, although geometries decrease more rapidly per bifurcation order. Measured distance to bifurcations in SDC

Assessing Niger-Delta Wetland Resources: A Case-Study of Mangrove Ecosystem

Science.gov (United States)

Anwan, R. H.; Ndimele, P. E.; Whenu, O. O.; Anetekhai, M. A.; Essien-Ibok, M. A.; Erondu, E. S.

2016-02-01

The Niger Delta is located in the Atlantic coast of Southern Nigeria and is the world's second largest delta with a coastline of about 450km. The Niger Delta region occupies a surface area of about 112,110km2, representing about 12% of Nigeria's total surface area. The Delta's environment can be broken down into four ecological zones: coastal barrier islands, mangrove swamp forests, freshwater swamps, and lowland rainforests. The mangrove swamps of Niger Delta, which is the largest delta in Africa constitute the dominant wetland ecosystem in the Niger Delta region and covers an area of about 1,900km2. Mangroves constitute important nurseries for fishes, crustaceans, sponges, algae and other invertebrates, and also acts as a sink, retaining pollutants from contaminated tidal water. The Niger Delta mangrove together with the creeks and rivers are a major source of food and livelihood for about 30 million people, which represents more than 17% of Nigeria's population. Other ecosystem services provided by this unique environment are flood control, ground water re-fill, reservoir of biodiversity, fuel wood, cultural values etc. This ecosystem also plays important role in climate change mitigation because of its high blue carbon sequestration potential. This is particularly important because of continuous gas flaring in Niger Delta from petroleum operations, which releases carbon dioxide among other gases into the atmosphere. This wetland is potentially a good site for ecotourism and also qualifies to be a world heritage site and Ramsar site if proper steps are taken. The benefits derivable from this fragile ecosystem are under severe threat by anthropogenic stressors. These include the installation of pipelines and seismic exploration by oil companies, crude oil pollution, deforestation, urbanization etc. This paper discusses the extent of depletion and loss of mangrove ecosystem in the Niger Delta region and the value of its goods and services.

Implications for future survival of delta smelt from four climate change scenarios for the Sacramento–San Joaquin Delta, California

Science.gov (United States)

Brown, Larry R.; Bennett, William A.; Wagner, R. Wayne; Morgan-King, Tara; Knowles, Noah; Feyrer, Frederick; Schoellhamer, David H.; Stacey, Mark T.; Dettinger, Mike

2013-01-01

Changes in the position of the low salinity zone, a habitat suitability index, turbidity, and water temperature modeled from four 100-year scenarios of climate change were evaluated for possible effects on delta smelt Hypomesus transpacificus, which is endemic to the Sacramento–San Joaquin Delta. The persistence of delta smelt in much of its current habitat into the next century appears uncertain. By mid-century, the position of the low salinity zone in the fall and the habitat suitability index converged on values only observed during the worst droughts of the baseline period (1969–2000). Projected higher water temperatures would render waters historically inhabited by delta smelt near the confluence of the Sacramento and San Joaquin rivers largely uninhabitable. However, the scenarios of climate change are based on assumptions that require caution in the interpretation of the results. Projections like these provide managers with a useful tool for anticipating long-term challenges to managing fish populations and possibly adapting water management to ameliorate those challenges.

Water and nitrogen conditions affect the relationships of Delta13C and Delta18O to gas exchange and growth in durum wheat.

Science.gov (United States)

Cabrera-Bosquet, Llorenç; Molero, Gemma; Nogués, Salvador; Araus, José Luis

2009-01-01

Whereas the effects of water and nitrogen (N) on plant Delta(13)C have been reported previously, these factors have scarcely been studied for Delta(18)O. Here the combined effect of different water and N regimes on Delta(13)C, Delta(18)O, gas exchange, water-use efficiency (WUE), and growth of four genotypes of durum wheat [Triticum turgidum L. ssp. durum (Desf.) Husn.] cultured in pots was studied. Water and N supply significantly increased plant growth. However, a reduction in water supply did not lead to a significant decrease in gas exchange parameters, and consequently Delta(13)C was only slightly modified by water input. Conversely, N fertilizer significantly decreased Delta(13)C. On the other hand, water supply decreased Delta(18)O values, whereas N did not affect this parameter. Delta(18)O variation was mainly determined by the amount of transpired water throughout plant growth (T(cum)), whereas Delta(13)C variation was explained in part by a combination of leaf N and stomatal conductance (g(s)). Even though the four genotypes showed significant differences in cumulative transpiration rates and biomass, this was not translated into significant differences in Delta(18)O(s). However, genotypic differences in Delta(13)C were observed. Moreover, approximately 80% of the variation in biomass across growing conditions and genotypes was explained by a combination of both isotopes, with Delta(18)O alone accounting for approximately 50%. This illustrates the usefulness of combining Delta(18)O and Delta(13)C in order to assess differences in plant growth and total transpiration, and also to provide a time-integrated record of the photosynthetic and evaporative performance of the plant during the course of crop growth.

Deformation characteristics of {delta} phase in the delta-processed Inconel 718 alloy

Energy Technology Data Exchange (ETDEWEB)

Zhang, H.Y., E-mail: haiyanzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Zhang, S.H., E-mail: shzhang@imr.ac.cn [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Cheng, M. [Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China); Li, Z.X. [Beijing Institute of Aeronautica1 Materials, Beijing 100095 (China)

2010-01-15

The hot working characteristics of {delta} phase in the delta-processed Inconel 718 alloy during isothermal compression deformation at temperature of 950 deg. C and strain rate of 0.005 s{sup -1}, were studied by using optical microscope, scanning electron microscope and quantitative X-ray diffraction technique. The results showed that the dissolution of plate-like {delta} phase and the precipitation of spherical {delta} phase particles coexisted during the deformation, and the content of {delta} phase decreased from 7.05 wt.% to 5.14 wt.%. As a result of deformation breakage and dissolution breakage, the plate-like {delta} phase was spheroidized and transferred to spherical {delta} phase particles. In the center with largest strain, the plate-like {delta} phase disappeared and spherical {delta} phase appeared in the interior of grains and grain boundaries.

Delta progradation in Greenland driven by increasing glacial mass loss

DEFF Research Database (Denmark)

Bendixen, Mette; Iversen, Lars Lonsmann; Bjork, Anders Anker

2017-01-01

imagery. We find that delta progradation was driven by high freshwater runoff from the Greenland Ice Sheet coinciding with periods of open water. Progradation was controlled by the local initial environmental conditions (that is, accumulated air temperatures above 0 degrees C per year, freshwater runoff...... of erosion and accretion along the large deltas of the main rivers in the Arctic5-7. Our results improve the understanding of Arctic coastal evolution in a changing climate, and reveal the impacts on coastal areas of increasing ice mass loss and the associated freshwater runoff and lengthening of open-water...

Delta antibody radioimmunoassay

Energy Technology Data Exchange (ETDEWEB)

Kselikova, M; Urbankova, J

1985-11-15

The principle and procedure are described of the radioimmunoassay of delta antibody (delta-Ab) using the ABBOTT ANTI-DELTA kit by Abbott Co. A description is given of the kit, the working procedure and the method of evaluation. The results are reported of the incidence of delta-Ab in sera of patients with viral hepatitis B, in haemophiliacs, carriers of the hepatitis B virus surface antigen (HBsAg) and blood donors. The presence was detected of delta-Ab in one HBsAg carrier. The necessity is emphasized of delta-Ab determinations in the blood of donors in view of the antibody transfer with blood and blood preparations.

Perspectives on bay-delta science and policy

Science.gov (United States)

Healey, Michael; Dettinger, Michael; Norgaard, Richard

2016-01-01

The State of Bay–Delta Science 2008 highlighted seven emerging perspectives on science and management of the Delta. These perspectives had important effects on policy and legislation concerning management of the Delta ecosystem and water exports. From the collection of papers that make up the State of Bay–Delta Science 2016, we derive another seven perspectives that augment those published in 2008. The new perspectives address nutrient and contaminant concentrations in Delta waters, the failure of the Delta food web to support native species, the role of multiple stressors in driving species toward extinction, and the emerging importance of extreme events in driving change in the ecosystem and the water supply. The scientific advances that underpin these new perspectives were made possible by new measurement and analytic tools. We briefly discuss some of these, including miniaturized acoustic fish tags, sensors for monitoring of water quality, analytic techniques for disaggregating complex contaminant mixtures, remote sensing to assess levee vulnerability, and multidimensional hydrodynamic modeling. Despite these new tools and scientific insights, species conservation objectives for the Delta are not being met. We believe that this lack of progress stems in part from the fact that science and policy do not incorporate sufficiently long-term perspectives. Looking forward half a century was central to the Delta Visioning process, but science and policy have not embraced this conceptual breadth. We are also concerned that protection and enhancement of the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place, as required by the Delta Reform Act, has received no critical study and analysis. Adopting wider and longer science and policy perspectives immediately encourages recognition of the need for evaluation, analysis, and public discourse on novel conservation approaches. These longer and wider perspectives

Perspectives on Bay–Delta Science and Policy

Directory of Open Access Journals (Sweden)

Michael Healey

2016-12-01

Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art6The State of Bay–Delta Science 2008 highlighted seven emerging perspectives on science and management of the Delta. These perspectives had important effects on policy and legislation concerning management of the Delta ecosystem and water exports. From the collection of papers that make up the State of Bay–Delta Science 2016, we derive another seven perspectives that augment those published in 2008. The new perspectives address nutrient and contaminant concentrations in Delta waters, the failure of the Delta food web to support native species, the role of multiple stressors in driving species toward extinction, and the emerging importance of extreme events in driving change in the ecosystem and the water supply. The scientific advances that underpin these new perspectives were made possible by new measurement and analytic tools. We briefly discuss some of these, including miniaturized acoustic fish tags, sensors for monitoring of water quality, analytic techniques for disaggregating complex contaminant mixtures, remote sensing to assess levee vulnerability, and multidimensional hydrodynamic modeling. Despite these new tools and scientific insights, species conservation objectives for the Delta are not being met. We believe that this lack of progress stems in part from the fact that science and policy do not incorporate sufficiently long-term perspectives. Looking forward half a century was central to the Delta Visioning process, but science and policy have not embraced this conceptual breadth. We are also concerned that protection and enhancement of the unique cultural, recreational, natural resource, and agricultural values of the Delta as an evolving place, as required by the Delta Reform Act, has received no critical study and analysis. Adopting wider and longer science and policy perspectives immediately encourages recognition of the need for evaluation, analysis, and public discourse on

TU-D-207B-02: Delta-Radiomics: The Prognostic Value of Therapy-Induced Changes in Radiomics Features for Stage III Non-Small Cell Lung Cancer Patients

International Nuclear Information System (INIS)

Fave, X; Court, L; Zhang, L; Yang, J; Mackin, D; Stingo, F; Followill, D; Balter, P; Jones, A; Gomez, D

2016-01-01

Purpose: To determine how radiomics features change during radiation therapy and whether those changes (delta-radiomics features) can improve prognostic models built with clinical factors. Methods: 62 radiomics features, including histogram, co-occurrence, run-length, gray-tone difference, and shape features, were calculated from pretreatment and weekly intra-treatment CTs for 107 stage III NSCLC patients (5–9 images per patient). Image preprocessing for each feature was determined using the set of pretreatment images: bit-depth resample and/or a smoothing filter were tested for their impact on volume-correlation and significance of each feature in univariate cox regression models to maximize their information content. Next, the optimized features were calculated from the intratreatment images and tested in linear mixed-effects models to determine which features changed significantly with dose-fraction. The slopes in these significant features were defined as delta-radiomics features. To test their prognostic potential multivariate cox regression models were fitted, first using only clinical features and then clinical+delta-radiomics features for overall-survival, local-recurrence, and distant-metastases. Leave-one-out cross validation was used for model-fitting and patient predictions. Concordance indices(c-index) and p-values for the log-rank test with patients stratified at the median were calculated. Results: Approximately one-half of the 62 optimized features required no preprocessing, one-fourth required smoothing, and one-fourth required smoothing and resampling. From these, 54 changed significantly during treatment. For overall-survival, the c-index improved from 0.52 for clinical factors alone to 0.62 for clinical+delta-radiomics features. For distant-metastases, the c-index improved from 0.53 to 0.58, while for local-recurrence it did not improve. Patient stratification significantly improved (p-value<0.05) for overallsurvival and distant

TU-D-207B-02: Delta-Radiomics: The Prognostic Value of Therapy-Induced Changes in Radiomics Features for Stage III Non-Small Cell Lung Cancer Patients

Energy Technology Data Exchange (ETDEWEB)

Fave, X; Court, L [UT MD Anderson Cancer Center, Houston, TX (United States); UT Health Science Center, Graduate School of Biomedical Sciences, Houston, TX (United States); Zhang, L; Yang, J; Mackin, D; Stingo, F; Followill, D; Balter, P; Jones, A; Gomez, D [UT MD Anderson Cancer Center, Houston, TX (United States)

2016-06-15

Purpose: To determine how radiomics features change during radiation therapy and whether those changes (delta-radiomics features) can improve prognostic models built with clinical factors. Methods: 62 radiomics features, including histogram, co-occurrence, run-length, gray-tone difference, and shape features, were calculated from pretreatment and weekly intra-treatment CTs for 107 stage III NSCLC patients (5–9 images per patient). Image preprocessing for each feature was determined using the set of pretreatment images: bit-depth resample and/or a smoothing filter were tested for their impact on volume-correlation and significance of each feature in univariate cox regression models to maximize their information content. Next, the optimized features were calculated from the intratreatment images and tested in linear mixed-effects models to determine which features changed significantly with dose-fraction. The slopes in these significant features were defined as delta-radiomics features. To test their prognostic potential multivariate cox regression models were fitted, first using only clinical features and then clinical+delta-radiomics features for overall-survival, local-recurrence, and distant-metastases. Leave-one-out cross validation was used for model-fitting and patient predictions. Concordance indices(c-index) and p-values for the log-rank test with patients stratified at the median were calculated. Results: Approximately one-half of the 62 optimized features required no preprocessing, one-fourth required smoothing, and one-fourth required smoothing and resampling. From these, 54 changed significantly during treatment. For overall-survival, the c-index improved from 0.52 for clinical factors alone to 0.62 for clinical+delta-radiomics features. For distant-metastases, the c-index improved from 0.53 to 0.58, while for local-recurrence it did not improve. Patient stratification significantly improved (p-value<0.05) for overallsurvival and distant

A novel mouse PKC{delta} splice variant, PKC{delta}IX, inhibits etoposide-induced apoptosis

Energy Technology Data Exchange (ETDEWEB)

Kim, Jung D. [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Seo, Kwang W. [Department of Internal Medicines, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Lee, Eun A.; Quang, Nguyen N. [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Cho, Hong R. [Department of Surgery, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Biomedical Research Center, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of); Kwon, Byungsuk, E-mail: bskwon@mail.ulsan.as.kr [School of Biological Sciences, University of Ulsan, Ulsan (Korea, Republic of); Biomedical Research Center, Ulsan University Hospital and School of Medicine, University of Ulsan, Ulsan (Korea, Republic of)

2011-07-01

Highlights: {yields} A novel PKC{delta} isoform, named PKC{delta}IX, that lacks the C1 domain and the ATP-binding site is ubiquitously expressed. {yields} PKC{delta}IX inhibits etoposide-induced apoptosis. {yields} PKC{delta}IX may function as an endogenous dominant negative isoform for PKC{delta}. -- Abstract: Protein kinase C (PKC) {delta} plays an important role in cellular proliferation and apoptosis. The catalytic fragment of PKC{delta} generated by caspase-dependent cleavage is essential for the initiation of etoposide-induced apoptosis. In this study, we identified a novel mouse PKC{delta} isoform named PKC{delta}IX (Genebank Accession No. (HQ840432)). PKC{delta}IX is generated by alternative splicing and is ubiquitously expressed, as seen in its full-length PKC{delta}. PKC{delta}IX lacks the C1 domain, the caspase 3 cleavage site, and the ATP binding site but preserves an almost intact c-terminal catalytic domain and a nuclear localization signal (NLS). The structural characteristics of PKC{delta}IX provided a possibility that this PKC{delta} isozyme functions as a novel dominant-negative form for PKC{delta} due to its lack of the ATP-binding domain that is required for the kinase activity of PKC{delta}. Indeed, overexpression of PKC{delta}IX significantly inhibited etoposide-induced apoptosis in NIH3T3 cells. In addition, an in vitro kinase assay showed that recombinant PKC{delta}IX protein could competitively inhibit the kinase activity of PKC{delta}. We conclude that PKC{delta}IX can function as a natural dominant-negative inhibitor of PKC{delta}in vivo.

Types of hypoxic and posthypoxic delta activity in animals and man.

Science.gov (United States)

Gurvitch, A M; Ginsburg, D A

1977-03-01

1. Two types of hypoxic delta activity were observed in ECoG records of dogs subjected to exsanguination, sudden cardiac arrest resulting from ventricular fibrillation or mechanical asphyxiation, as well as during post-hypoxic recovery. They were polymorphous delta activity (PDA) and "standard slow complexes" (SSCs). 2. These two types of delta activity were found to differ from each other as to the shape of the potentials; their amplitude in monopolar and bipolar leads; the cortical areas in which the activity exhibited the highest amplitude; the degree of manifestation in the cortex and subcortical structures; their relation to activating influences; their dependence on the stage and character of hypoxia. 3. Analysis of EEG records of patients during and after hypoxia made it possible to distinguish both PDA and a type of delta activity similar to the SSCs observed in experimental animals. 4. It is suggested that the appearance of SSCs is determined by the activity of a pacemaker situated in the diencephalon and responding to pO2 changes, and that the mechanism of SSC generation is closer to that of monorhythmic, bilataerally synchronous delta waves observed in primary irritative or epileptogenic processes in the diencephalon.

Is there a self-organization principle of river deltas?

Science.gov (United States)

Tejedor, Alejandro; Longjas, Anthony; Foufoula-Georgiou, Efi

2017-04-01

River deltas are known to possess a complex topological and flux-partitioning structure which has recently been quantified using spectral graph theory [Tejedor et al., 2015a,b]. By analysis of real and simulated deltas it has also been shown that there is promise in formalizing relationships between this topo-dynamic delta structure and the underlying delta forming processes [e.g., Tejedor et al., 2016]. The question we pose here is whether there exists a first order organizational principle behind the self-organization of river deltas and whether this principle can be unraveled from the co-evolving topo-dynamic structure encoded in the delta planform. To answer this question, we introduce a new metric, the nonlocal Entropy Rate (nER) that captures the information content of a delta network in terms of the degree of uncertainty in delivering fluxes from any point of the network to the shoreline. We hypothesize that if the "guiding principle" of undisturbed deltas is to efficiently and robustly build land by increasing the diversity of their flux pathways over the delta plane, then they would exhibit maximum nonlocal Entropy Rate at states at which geometry and flux dynamics are at equilibrium. At the same time, their nER would be non-optimal at transient states, such as before and after major avulsions during which topology and dynamics adjust to each other to reach a new equilibrium state. We will present our results for field and simulated deltas, which confirm this hypothesis and open up new ways of thinking about self-organization, complexity and robustness in river deltas. One particular connection of interest might have important implications since entropy rate and resilience are related by the fluctuation theorem [Demetrius and Manke, 2005], and therefore our results suggest that deltas might in fact self-organize to maximize their resilience to structural and dynamic perturbations. References: Tejedor, A., A. Longjas, I. Zaliapin, and E. Foufoula

Flipped SU(5) predicts {delta}T/T

Energy Technology Data Exchange (ETDEWEB)

Kyae, Bumseok [School of Physics, Korea Institute for Advanced Study, 207-43, Cheongnyangni-Dong, Dongdaemun-Gu, Seoul 130-722 (Korea, Republic of)]. E-mail: bkyae@kias.re.kr; Shafi, Qaisar [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, DE 19716 (United States)]. E-mail: shafi@bartol.udel.edu

2006-04-20

We discuss hybrid inflation in supersymmetric flipped SU(5) model such that the cosmic microwave anisotropy {delta}T/T is essentially proportional to (M/M{sub P}){sup 2}, where M denotes the symmetry breaking scale and M{sub P} (=2.4x10{sup 18} GeV) is the reduced Planck mass. The magnitude of M determined from {delta}T/T measurements can be consistent with the value inferred from the evolution of SU(3) and SU(2) gauge couplings. In other words, one could state that flipped SU(5) predicts (more precisely 'postdicts') {delta}T/T. The scalar spectral index n{sub s}=0.993+/-0.007, the scalar to tensor ratio satisfies r-bar 10{sup -6}, while dn{sub s}/dlnk-bar 4x10{sup -4}.

Protoneutron star formation with delta-resonance matter and trapped neutrinos

International Nuclear Information System (INIS)

Oliveira, Jose Carlos Teixeira de; Souza, Ana Graice de; Duarte, Sergio Barbosa; Rodrigues, Hilario

2009-01-01

Full text: We discuss the proto-neutron star structure including delta-matter in its composition, and comparing the result with the same mass post-cooling compact object formed. The maximum mass values and corresponding configurations to pre and post-cooling situation are calculated and discussed face to variations in the coupling constants of delta-resonance with the mesons sigma, omega and rho in the context of the Relativistic Mean Field Theory (RMFT). The complete spin-1/2 sector is included solved consistently with the presence of the 3/2-spin delta-resonance quartet. (author)

Delta Dynamics

DEFF Research Database (Denmark)

Bendixen, Mette

. The warming air temperature affects the soil temperature and permafrost thaws and destabilizes the material in the coastal zone. In Greenland, the warming temperature lowers the surface mass balance of the Greenland Ice Sheet and more material is transported to the coastal zone. The sea ice extent is thinning...... of a fjord and the second type is a wider fan-shaped open delta. Most deltas are directly coupled to the Greenland Ice Sheet or local icecaps and are highly influenced by the dynamics in the catchments. It is demonstrated how a modern changing climate directly affects delta dynamics, and that Greenlandic...... deltas are prograding, contrary to the global trend showing eroding Arctic coasts. Moreover, it is revealed that the increasing proglacial freshwater runoff, caused by a lowering of the surface mass balance of the Greenland Ice Sheet is the main determining agent in delta progradation. The final part...

Evaluation of the Accuracy of NASS/CDS Delta-V Estimates from the Enhanced WinSmash Algorithm

Science.gov (United States)

Hampton, Carolyn E.; Gabler, Hampton C.

2010-01-01

The National Automotive Sampling System / Crashworthiness Data System (NASS/CDS) uses the WinSmash program to reconstruct changes in vehicle velocity for real world crashes. Vehicle change in velocity, or delta-V, is a measure of crash severity and a predictor of injury risk. Earlier studies have demonstrated that WinSmash 2.42 underestimated the delta-V by 23% on average with the use of categorical stiffness values for vehicles identified as a source of error. An enhanced version of WinSmash, WinSmash 2008, was developed to employ vehicle specific stiffness values whenever possible. A total of 478 General Motors vehicles equipped with event data recorders (EDRs) and involved in real-world crashes were collected from years 2000 – 2008 of the NASS/CDS database and the delta-V was computed using the enhanced WinSmash. All vehicles were involved in frontal impacts. The enhanced reconstruction algorithm reduced the underestimation of delta-V from 23% to 13% on average for all vehicles. Delta-V estimates for cars only were greatly improved but still understated by 16% on average. Less than 5% error in delta-V was observed for pickup trucks and utility vehicles. The amount of structural overlap for the vehicle and investigator confidence in the reconstruction continued to have an effect on accuracy. No difference in average delta-V was observed when using either updated categorical stiffness values or vehicle specific stiffness values. The changes in WinSmash delta-Vs have important policy implications for NHTSA as the NASS/CDS delta-Vs are the basis for traffic and safety regulations as well as the speeds for vehicular crash testing and costs/benefits analyses. PMID:21050607

Stringent tests of constrained Minimal Flavor Violation through {Delta}F=2 transitions

Energy Technology Data Exchange (ETDEWEB)

Buras, Andrzej J. [TUM-IAS, Garching (Germany); Girrbach, Jennifer [TUM, Physik Department, Garching (Germany)

2013-09-15

New Physics contributions to {Delta}F=2 transitions in the simplest extensions of the Standard Model (SM), the models with constrained Minimal Flavor Violation (CMFV), are parametrized by a single variable S(v), the value of the real box diagram function that in CMFV is bounded from below by its SM value S{sub 0}(x{sub t}). With already very precise experimental values of {epsilon}{sub K}, {Delta}M{sub d}, {Delta}M{sub s} and precise values of the CP-asymmetry S{sub {psi}K{sub S}} and of B{sub K} entering the evaluation of {epsilon}{sub K}, the future of CMFV in the {Delta}F = 2 sector depends crucially on the values of vertical stroke V{sub cb} vertical stroke, vertical stroke V{sub ub} vertical stroke, {gamma}, F{sub B{sub s}} {radical}(B{sub B{sub s}}) and F{sub B{sub d}} {radical}(B{sub B{sub d}}). The ratio {xi} of the latter two non-perturbative parameters, already rather precisely determined from lattice calculations, allows then together with {Delta}M{sub s} / {Delta}M{sub d} and S{sub {psi}K{sub S}} to determine the range of the angle {gamma} in the unitarity triangle independently of the value of S(v). Imposing in addition the constraints from vertical stroke {epsilon}{sub K} vertical stroke and {Delta}M{sub d} allows to determine the favorite CMFV values of vertical stroke V{sub cb} vertical stroke, vertical stroke V{sub ub} vertical stroke, F{sub B{sub s}} {radical}(B{sub B{sub s}}) and F{sub B{sub d}} {radical}(B{sub B{sub d}}) as functions of S(v) and {gamma}. The vertical stroke V{sub cb} vertical stroke {sup 4} dependence of {epsilon}{sub K} allows to determine vertical stroke V{sub cb} vertical stroke for a given S(v) and {gamma} with a higher precision than it is presently possible using tree-level decays. The same applies to vertical stroke V{sub ub} vertical stroke, vertical stroke V{sub td} vertical stroke and vertical stroke V{sub ts} vertical stroke that are automatically determined as functions of S(v) and {gamma}. We derive correlations

Holocene evolution of a wave-dominated fan-delta: Godavari delta, India

Science.gov (United States)

Saito, Y.; Nageswara Rao, K.; Nagakumar, K.; Demudu, G.; Rajawat, A.; Kubo, S.; Li, Z.

2013-12-01

The Godavari delta is one of the world's largest wave-dominated deltas. The Godavari River arises in the Western Ghats near the west coast of India and drains an area of about 3.1x10^5 km^2, flowing about 1465 km southeast across the Indian peninsula to the Bay of Bengal. The Godavari delta consists of a gentle seaward slope from its apex (12 m elevation) at Rajahmundry and a coastal beach-ridge plain over a distance of about 75 km and covers ~5200 km^2 as a delta plain. The river splits into two major distributary channels, the Gautami and the Vasishta, at a barrage constructed in the mid-1800s. The coastal environment of the deltaic coast is microtidal (~1 m mean tidal range) and wave-dominated (~1.5 m mean wave height in the June-September SW monsoon season, ~0.8 m in the NE monsoon season). Models of the Holocene evolution of the Godavari delta have changed from a zonal progradation model (e.g. Nageswara Rao & Sadakata, 1993) to a truncated cuspate delta model (Nageswara Rao et al., 2005, 2012). Twelve borehole cores (340 m total length), taken in the coastal delta plain during 2010-2013, yielded more than 100 C-14 dates. Sediment facies and C-14 dates from these and previous cores and remote-sensing data support a new delta evolution model. The Holocene coastal delta plain is divided into two parts by a set of linear beach ridges 12-14 km landward from the present shoreline in the central part of the delta. The location of the main depocenter (lobe) has shifted during the Holocene from 1) the center to 2) the west, 3) east, 4) center, 5) west, and 6) east. The linear beach ridges separate the first three from the last three stages. These lobe shifts are controlled by river channel shifts near the apex. Just as the current linear shoreline of the central part of the delta and the concave-up nearshore topography are the result of coastal erosion of a cuspate delta, the linear beach ridges indicate a former eroded shoreline. An unconformity within the deltaic

A dynamic soil chamber system coupled with a tunable diode laser for online measurements of delta-13C, delta-18O, and efflux rate of soil respired CO2

Energy Technology Data Exchange (ETDEWEB)

Powers, Heath H [Los Alamos National Laboratory; Mcdowell, Nate [Los Alamos National Laboratory; Hanson, David [UNM; Hunt, John [LANDCARE RESEARCH

2009-01-01

High frequency observations of the stable isotopic composition of CO(2) effluxes from soil have been sparse due in part to measurement challenges. We have developed an open-system method that utilizes a flow-through chamber coupled to a tunable diode laser (TDL) to quantify the rate of soil CO(2) efflux and its delta(13)C and delta(18)O values (delta(13)C(R) and delta(18)O(R), respectively). We tested the method first in the laboratory using an artificial soil test column and then in a semi-arid woodland. We found that the CO(2) efflux rates of 1.2 to 7.3 micromol m(-2) s(-1) measured by the chamber-TDL system were similar to measurements made using the chamber and an infrared gas analyzer (IRGA) (R(2) = 0.99) and compared well with efflux rates generated from the soil test column (R(2) = 0.94). Measured delta(13)C and delta(18)O values of CO(2) efflux using the chamber-TDL system at 2 min intervals were not significantly different from source air values across all efflux rates after accounting for diffusive enrichment. Field measurements during drought demonstrated a strong dependency of CO(2) efflux and isotopic composition on soil water content. Addition of water to the soil beneath the chamber resulted in average changes of +6.9 micromol m(-2) s(-1), -5.0 per thousand, and -55.0 per thousand for soil CO(2) efflux, delta(13)C(R) and delta(18)O(R), respectively. All three variables initiated responses within 2 min of water addition, with peak responses observed within 10 min for isotopes and 20 min for efflux. The observed delta(18)O(R) was more enriched than predicted from temperature-dependent H(2)O-CO(2) equilibration theory, similar to other recent observations of delta(18)O(R) from dry soils (Wingate L, Seibt U, Maseyk K, Ogee J, Almeida P, Yakir D, Pereira JS, Mencuccini M. Global Change Biol. 2008; 14: 2178). The soil chamber coupled with the TDL was found to be an effective method for capturing soil CO(2) efflux and its stable isotope composition at high

The influence of delta formation mechanism on geotechnical property sequence of the late Pleistocene–Holocene sediments in the Mekong River Delta

Directory of Open Access Journals (Sweden)

Truong Minh Hoang

2016-11-01

Full Text Available The aim of the study was to characterize a variety of microstructure development-levels and geotechnical property sequences of the late Pleistocene–Holocene deposits in the Mekong River delta (MRD, and the paper furthermore discusses the influences of delta formation mechanisms on them. The survey associated the geotechnical engineering and the sedimentary geology of the late Pleistocene–Holocene deposits at five sites and also undifferentiated Pleistocene sediments. A cross-section which was rebuilt in the delta progradation-direction and between the Mekong and Bassac rivers represents the stratigraphy. Each sedimentary unit was formed under a different delta formation mechanism and revealed a typical geotechnical property sequence. The mechanical behaviors of the sediment succession in the tide-dominated delta with significant fluvial-activity and material source tend to be more cohesionless soils and strengths than those in the tide- and wave-dominated delta and even the coast. The particular tendency of the mechanical behavior of the deposit succession can be reasonably estimated from the delta formation mechanism. The characteristics of the clay minerals from the Mekong River produced the argillaceous soil which does not have extremely high plasticity. The microstructure development-levels are low to very high indicating how to choose hydraulic conductivity value, k, for estimating overconsolidation ratio, OCR, by the piezocone penetration tests (CPTU. The OCR of sediments in the delta types strangely change with depth but none less than 1. The post-depositional processes significantly influenced the microstructure development, particularly the dehydrating and oxidizing processes.

Relevance between the degree of industrial competition and fair value information: Study on the listed companies in China

Directory of Open Access Journals (Sweden)

Xuemin Zhuang

2015-05-01

Full Text Available Purpose: The purpose of this article is to study whether there exists natural relationship between fair value and corporate external market. A series of special phenomenon in the application of fair value arouses our research interests, which present evidences on how competition affects the correlation of fair value information. Design/methodology/approach: this thesis chooses fair value changes gains and losses and calculate the ratio of DFVPSit as the alternative variable of the fair value. In order to effectively inspect the mutual influence between the degree of industry competition and the value relevance of fair value, and reduce the impact of multi-collinearity, we built a regression model on the hypothesis, which supposes that if other conditions are the same, the fair value information has greater value relevance if the degree of the industry competition is greater. To test the hypothesis, we use the comparison of the DFVPSit coefficient absolute value to judge the value relevance of fair value information, and the greater the absolute value is, the higher relevance between the changes in fair value per share profits and losses with the stock prices. Findings: The higher the degree of competition in the industry is, the more fair value information relevance is. Also, there are evidences representing that fair value information often presents negative correlation with the stock price. Originality/value: The main contribution of the article is to show that not only need we make the formulation and implementation of the high quality of fair value accounting standards to suit for both the national conditions and international practice, but also need we further to improve the company's external governance mechanism to promote fair value’s information correlation.

Estimation of water transit time in soils under Amazon forest cover using variations in delta18O values

International Nuclear Information System (INIS)

Leopoldo, P.R.; Matsui, E.; Salati, E.

1984-01-01

The work was carried out at the forest reserve of the Instituto Nacional de Pesquisas da Amazonia, located at km 45 of Manaus, in an area characterized by Amazon vegetation of the 'terra-firme' type. To extract the soil water, four soil-water collecting stations were installed, and in each the porous cups were placed at 15, 25, 50, 80 and 120 cm depth from the soil surface. The rain-water and soil-water samples were collected only weekly for analysis of the 18 O content. In an attempt to estimate the soil-water transit time using the variation in 18 O values, a statistical model was used. This model is based on linear regression analysis applied to the values observed for soil water and rain water. From this analysis, regression coefficients are obtained which vary according to time. The values of the coefficients obtained can be adjusted generally, according to a quadratic regression, with the maximum value of the function representing the time in which the best statistical correlation between the observed delta 18 O values occurs. The time obtained from these correlations represents the mean time necessary for the water to run from one collecting point to the next. (author)

Identification of anthropogenic and natural inputs of sulfate and chloride into the karstic ground water of Guiyang, SW China: combined delta37Cl and delta34S approach.

Science.gov (United States)

Liu, Cong-Qiang; Lang, Yun-Chao; Satake, Hiroshi; Wu, Jiahong; Li, Si-Liang

2008-08-01

Because of active exchange between surface and groundwater of a karstic hydrological system, the groundwater of Guiyang, the capital city of Guizhou Province, southwest China, has been seriously polluted by anthropogenic inputs of NO3-, SO4(2-), Cl-, and Na+. In this work, delta37Cl of chloride and delta34S variations of sulfate in the karstic surface/groundwater system were studied, with a main focus to identify contaminant sources, including their origins. The surface, ground, rain, and sewage water studied showed variable delta37Cl and delta34S values, in the range of -4.1 to +2.0 per thousand, and -20.4 to +20.9 per thousand for delta37Cl and delta34S (SO4(2-)), respectively. The rainwater samples yielded the lowest delta37Cl values among those observed to date for aerosols and rainwater. Chloride in the Guiyang area rain waters emanated from anthropogenic sources rather than being of marine origin, probably derived from HCl (g) emitted by coal combustion. By plotting 1/SO4(2-) vs delta34S and 1/Cl- vs delta37Cl, respectively, we were able to identify some clusters of data, which were assigned as atmospheric deposition (acid rain component), discharge from municipal sewage, paleo-brine components in clastic sedimentary rocks, dissolution of gypsum mainly in dolomite, oxidation of sulfide minerals in coal-containing clastic rocks, and possibly degradation of chlorine-containing organic matter. We conclude that human activities give a significant input of sulfate and chloride ions, as well as other contaminants, into the studied groundwater system through enhanced atmospheric deposition and municipal sewage, and that multiple isotopic tracers constitute a powerful tool to ascertain geochemical characteristics and origin of complex contaminants in groundwater.

{delta}{sup 15}N of seagrass leaves for monitoring anthropogenic nutrient increases in coral reef ecosystems

Energy Technology Data Exchange (ETDEWEB)

Yamamuro, M.; Kayanne, H.; Yamano, H

2003-04-01

In a coral reef environment, a slight increase in dissolved inorganic nitrogen (DIN;{>=}1.0 {mu}M) can alter the ecosystem via macroalgal blooms. We collected seagrass leaves from the tropical and subtropical Pacific Ocean in five countries and examined the interactions between nutrient concentrations (C, N, P), molar ratios of nutrients, and {delta}{sup 15}N to find a possible indicator of the DIN conditions. Within most sites, the concentrations of nutrients and their molar ratios showed large variations owing to species-specific values. On the other hand, almost identical {delta}{sup 15}N values were found in seagrass leaves of several species at each site. The correlations between {delta}{sup 15}N and nutrient concentrations and between {delta}{sup 15}N and molar ratios of nutrients suggested that nutrient availability did not affect the {delta}{sup 15}N value of seagrass leaves by altering the physiological condition of the plants. Increases in {delta}{sup 15}N of seagrass leaves mostly matched increases in DIN concentrations in the bottom water. We suggest that {delta}{sup 15}N in seagrass leaves can be a good tool to monitor time-integrated decrease/increase of DIN concentrations at a site, both in the water column and the interstitial water.

delta-vision

Data.gov (United States)

California Natural Resource Agency — Delta Vision is intended to identify a strategy for managing the Sacramento-San Joaquin Delta as a sustainable ecosystem that would continue to support environmental...

Growth laws for delta crevasses in the Mississippi River Delta: observations and modeling

Science.gov (United States)

Yocum, T. A.; Georgiou, I. Y.

2016-02-01

River deltas are accumulations of sedimentary deposits delivered by rivers via a network of distributary channels. Worldwide they are threatened by environmental changes, including subsidence, global sea level rise and a suite of other local factors. In the Mississippi River Delta (MRD) these impacts are exemplified, and have led to proposed solutions to build land that include sediment diversions, thereby reinitiating the delta cycle. While economically efficient, there are too few analogs of small deltas aside from laboratory studies, numerical modeling studies, theoretical approaches, and limited field driven observations. Anthropogenic crevasses in the modern delta are large enough to overcome limitations of laboratory deltas, and small enough to allow for "rapid" channel and wetland development, providing an ideal setting to investigate delta development mechanics. Crevasse metrics were obtained using a combination of geospatial tools, extracting key parameters (bifurcation length and width, channel order and depth) that were non-dimensionalized and compared to river-dominated delta networks previously studied. Analysis showed that most crevasses in the MRD appear to obey delta growth laws and delta allometry relationships, suggesting that crevasses do exhibit similar planform metrics to larger Deltas; the distance to mouth bar versus bifurcation order demonstrated to be a very reasonable first order estimate of delta-top footprint. However, some crevasses exhibited different growth metrics. To better understand the hydrodynamic and geomorphic controls governing crevasse evolution in the MRD, we assess delta dynamics via a suite of field observations and numerical modeling in both well-established and newly constructed crevasses. Our analysis suggests that delta development is affected by the relative influence of external (upstream and downstream) and internal controls on the hydrodynamic and sediment transport patterns in these systems.

[Shifting path of industrial pollution gravity centers and its driving mechanism in Pan-Yangtze River Delta].

Science.gov (United States)

Zhao, Hai-Xia; Jiang, Xiao-Wei; Cui, Jian-Xin

2014-11-01

Shifting path of industrial pollution gravity centers is the response of environmental special formation during the industry transfer process, in order to prove the responding of industrial pollution gravity centers to industry transfer in economically developed areas, this paper calculates the gravity centers of industrial wastewater, gas and solid patterns and reveals the shifting path and its driving mechanism, using the data of industrial pollution in the Pan-Yangtze River Delta from 2000 to 2010. The results show that the gravity center of the industrial waste in Pan-Yangtze River Delta shifts for sure in the last 10 years, and gravity center of solid waste shifts the maximum distance within the three wastes, which was 180.18 km, and shifting distances for waste gas and waste water were 109.51 km and 85.92 km respectively. Moreover, the gravity center of the industrial waste in Pan-Yangtze River Delta shifts westwards, and gravity centers of waste water, gas and solid shift for 0.40 degrees, 0.17 degrees and 0.03 degrees respectively. The shifting of industrial pollution gravity centers is driven by many factors. The rapid development of the heavy industry in Anhui and Jiangxi provinces results in the westward shifting of the pollutions. The optimization and adjustment of industrial structures in Yangtze River Delta region benefit to alleviating industrial pollution, and high-polluting industries shifted to Anhui and Jiangxi provinces promotes pollution gravity center shifting to west. While the development of massive clean enterprise, strong environmental management efforts and better environmental monitoring system slow the shifting trend of industrial pollution to the east in Yangtze River Delta. The study of industrial pollution gravity shift and its driving mechanism provides a new angle of view to analyze the relationship between economic development and environmental pollution, and also provides academic basis for synthetical management and control of

Color stability and degree of cure of direct composite restoratives after accelerated aging.

Science.gov (United States)

Sarafianou, Aspasia; Iosifidou, Soultana; Papadopoulos, Triantafillos; Eliades, George

2007-01-01

This study evaluated the color changes and amount of remaining C = C bonds (%RDB) in three dental composites after hydrothermal- and photoaging. The materials tested were Estelite sigma, Filtek Supreme and Tetric Ceram. Specimens were fabricated from each material and subjected to L* a* b* colorimetry and FTIR spectroscopy before and after aging. Statistical evaluation of the deltaL,* deltaa,* deltab,* deltaE and %deltaRDB data was performed by one-way ANOVA and Tukey's test. The %RDB data before and after aging were statistically analyzed using two-way ANOVA and Student-Newman-Keuls test. In all cases an alpha = 0.05 significance level was used. No statistically significant differences were found in deltaL*, deltaa*, deltaE and %deltaRDB among the materials tested. Tetric Ceram demonstrated a significant difference in deltab*. All the materials showed visually perceptible (deltaE >1) but clinically acceptable values (deltaE statistically significant differences in %RDB were noticed before and after aging (p statistically significantly different among all the groups tested. No correlation was found between deltaE and %deltaRDB.

COMMD1 regulates the delta epithelial sodium channel ({delta}ENaC) through trafficking and ubiquitination

Energy Technology Data Exchange (ETDEWEB)

Chang, Tina; Ke, Ying; Ly, Kevin [Department of Physiology, University of Otago, P.O. Box 913, Dunedin 9054 (New Zealand); McDonald, Fiona J., E-mail: fiona.mcdonald@otago.ac.nz [Department of Physiology, University of Otago, P.O. Box 913, Dunedin 9054 (New Zealand)

2011-08-05

Highlights: {yields} The COMM domain of COMMD1 mediates binding to {delta}ENaC. {yields} COMMD1 reduces the cell surface population of {delta}ENaC. {yields} COMMD1 increases the population of {delta}ENaC-ubiquitin. {yields} Both endogenous and transfected {delta}ENaC localize with COMMD1 and transferrin suggesting they are located in early/recycling endosomes. -- Abstract: The delta subunit of the epithelial sodium channel ({delta}ENaC) is a member of the ENaC/degenerin family of ion channels. {delta}ENaC is distinct from the related {alpha}-, {beta}- and {gamma}ENaC subunits, known for their role in sodium homeostasis and blood pressure control, as {delta}ENaC is expressed in brain neurons and activated by external protons. COMMD1 (copper metabolism Murr1 domain 1) was previously found to associate with and downregulate {delta}ENaC activity. Here, we show that COMMD1 interacts with {delta}ENaC through its COMM domain. Co-expression of {delta}ENaC with COMMD1 significantly reduced {delta}ENaC surface expression, and led to an increase in {delta}ENaC ubiquitination. Immunocytochemical and confocal microscopy studies show that COMMD1 promoted localization of {delta}ENaC to the early/recycling endosomal pool where the two proteins were localized together. These results suggest that COMMD1 downregulates {delta}ENaC activity by reducing {delta}ENaC surface expression through promoting internalization of surface {delta}ENaC to an intracellular recycling pool, possibly via enhanced ubiquitination.

Inhabiting the Delta: A Landscape Approach to Transformative Socio-Ecological Restoration

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Brett Milligan

2017-09-01

Full Text Available doi: https://doi.org/10.15447/sfews.2017v15iss3art3Current legislation and plans for the Sacramento–San Joaquin Delta (Delta call for large-scale restoration of aquatic and terrestrial habitats, which will require significant changes in waterways, land uses, and cultural patterns. These re-made landscapes will be subject to a variety of new human uses, which Delta planning and adaptive management literature has yet to adequately consider. Failing to account for human uses and evolving place values can lead to diminished performance and public support for Delta restoration efforts. Our empirical study examined restored and naturalized Delta landscapes using an integrative landscape approach that seeks to reconcile multiple goals and land-use agendas that span ecological, social, economic, and political domains. The research design consisted of six overlapping methods that included a planning, policy, and law review specific to the Delta; surveys and interviews with approximately 100 land managers, scientists, land-owners, law-enforcement personnel, agency representatives, and Delta residents; nine case studies of restored and naturalized delta landscapes; GIS mapping; and extensive field work. Findings derived from the synthesis of these methods show that human uses of the Delta’s re-wilded landscapes are diverse and pervasive. Given the infrastructural and urbanized context of the region, these environments are subject to multiple and sometimes conflicting uses, perceptions, and place values. Though these myriad uses cannot be fully predicted or controlled (nor should they be, findings showed that more proactive and inclusive planning for human uses can encourage or discourage particular uses while also building constituency, support, and active engagement in ecological restoration efforts. We conclude that reconciling human uses with ecological recovery in the Delta will require a more localized, multi-functional, and creative approach to

Future Deltas Utrecht University research focus area: towards sustainable management of sinking deltas

Science.gov (United States)

Stouthamer, E.; van Asselen, S.

2015-11-01

Deltas are increasingly under pressure from human impact and climate change. To deal with these pressures that threat future delta functioning, we need to understand interactions between physical, biological, chemical and social processes in deltas. This requires an integrated approach, in which knowledge on natural system functioning is combined with knowledge on spatial planning, land and water governance and legislative frameworks. In the research focus area Future Deltas of Utrecht University an interdisciplinary team from different research groups therefore works together. This allows developing integrated sustainable and resilient delta management strategies, which is urgently needed to prevent loss of vital delta services.

Study of 4f hybridization in CeNiX with X=Sn{sub d}eltaGe{sub 1-d}elta, 0<=delta<=1

Energy Technology Data Exchange (ETDEWEB)

Fuente, C. de la, E-mail: cesar@unizar.e [Depto. Fisica de la Materia Condensada, Laboratorio de Magnetismo, Universidad de Zaragoza and ICMA-CSIC (Spain); Moral, A. del [Depto. Fisica de la Materia Condensada, Laboratorio de Magnetismo, Universidad de Zaragoza and ICMA-CSIC (Spain); Adroja, D.T. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire OX11 0QX (United Kingdom); Fraile, A. [Depto. Fisica de la Materia Condensada, Laboratorio de Magnetismo, Universidad de Zaragoza and ICMA-CSIC (Spain); Arnaudas, J.I. [Instituto de Nanociencia de Aragon, Universidad de Zaragoza (Spain)

2010-05-15

We report inelastic neutron scattering and core-level X-ray photoemission spectroscopy experiments for studying the Kondo problem in the CeNiX, X=Sn{sub d}eltaGe{sub 1-d}elta 0<=delta<=1 series. The neutron results confirm that they behave like a Kondo lattice for delta>=0.85, showing broad maxima at around 30 meV, typical of a crystal field magnetic scattering. So, the Ge doping could produce the suppression of the cerium magnetism observed for delta<=0.25. To open a more deep sight on this point, we have analyzed the 3d core-level XPS spectra by using the well-known Gunnarsson-Schoenhammer model. From this analysis, we have obtained the 'on-site' Coulomb bare repulsion for f states, U, and hybridization parameter, DELTA, related with the hopping from the f states to the conduction ones. These U values are very similar for all compounds, about 7 eV, but the hybridization parameter slightly changes from 0.2 to 0.16 eV on increasing the Sn concentration. In Sn-rich compounds, the 4f occupation is close to spin limit fluctuation, which allows us to obtain an estimation of the Kondo temperatures, approx1200 K, and the static 0 K susceptibility, approx1.1x10{sup -3} emu/mol. Finally, we have done 'ab-initio' calculations based on the LDA+U+SO which confirm the existence of a small electronic gap opening in the DOS of Ge-rich compounds for U values lower than 7 eV.

Comparison of the difference and delta 15nitrogen approaches for evaluating liquid urea ammonium nitrate utilization by maize

International Nuclear Information System (INIS)

Clay, D.E.

1997-01-01

Isotopic nitrogen (N) research techniques may be required in watershed studies to determine the impact of landscape position on fertilizer efficiency and the soil supplying power. However, traditional approaches using 15N labeled fertilizer may not be suitable when farmer equipment is used. The delta 15N natural abundance isotopic approach has been used to evaluate N cycling in watersheds. The objectives of this study were to measure the precision of the delta 15N measurement by the Europa 20-20 ratio mass spectrometer (Europa Scientific Ltd, UK), and to compare the difference and delta 15N approaches for measuring fertilizer use by maize (Zea mays). A replicated field study containing two different N rates (0 and 15.7 g N m-2) were used for the study. Maize samples were collected at the 8th-leaf, silking, and plant maturity in 1992 and 1993. Samples were dried (80 degrees C), ground (1-mm), weighed (stover 12 mg and grain 3 mg), and analyzed for total N and delta 15N. Fertilizer utilization at the three growth stages was determined using the natural abundance delta 15N and nonisotopic difference (fertilizer-control) techniques. During the study, the Europa 20-20 ratio mass spectrometer (Europa Scientific Ltd, UK) analyzed over 100 samples a day and had consumable costs of less than $2.00 per sample. The standard deviations of the mean were less than 0.11 and 0.21 per thousand in 51 and 77% of the stover samples, respectively. In 1992, grain yields were not influenced by N fertilizer additions, while in 1993 grain yields were increased by N fertilizer. The difference method estimated that in 1992, 16% of the N fertilizer was utilized by the crop, while the natural abundance delta 15N approach estimated that 36% of the fertilizer N was used by the crop. Differences between calculated values by the two techniques resulted from the difference method calculating net fertilizer use, while the delta 15N approach calculated fertilizer contained in the plant

The Value of a College Degree

Science.gov (United States)

Rose, Stephen

2013-01-01

Although parents, high school students, and most civic leaders in this country and around the world see a college degree as important, this perspective has been attacked over the last five years. Once the Great Recession began in December 2007, there were far fewer good jobs available for new college graduates. The soaring price of college had…

How useful are delta checks in the 21st century? A stochastic-dynamic model of specimen mix-up and detection

Directory of Open Access Journals (Sweden)

Katie Ovens

2012-01-01

Full Text Available Introduction: Delta checks use two specimen test results taken in succession in order to detect test result changes greater than expected physiological variation. One of the most common and serious errors detected by delta checks is specimen mix-up errors. The positive and negative predictive values of delta checks for detecting specimen mix-up errors, however, are largely unknown. Materials and Methods: We addressed this question by first constructing a stochastic dynamic model using repeat test values for five analytes from approximately 8000 inpatients in Calgary, Alberta, Canada. The analytes examined were sodium, potassium, chloride, bicarbonate, and creatinine. The model simulated specimen mix-up errors by randomly switching a set number of pairs of second test results. Sensitivities and specificities were then calculated for each analyte for six combinations of delta check equations and cut-off values from the published literature. Results: Delta check specificities obtained from this model ranged from 50% to 99%; however the sensitivities were generally below 20% with the exception of creatinine for which the best performing delta check had a sensitivity of 82.8%. Within a plausible incidence range of specimen mix-ups the positive predictive values of even the best performing delta check equation and analyte became negligible. Conclusion: This finding casts doubt on the ongoing clinical utility of delta checks in the setting of low rates of specimen mix-ups.

Connectivity in river deltas

Science.gov (United States)

Passalacqua, P.; Hiatt, M. R.; Sendrowski, A.

2016-12-01

Deltas host approximately half a billion people and are rich in ecosystem diversity and economic resources. However, human-induced activities and climatic shifts are significantly impacting deltas around the world; anthropogenic disturbance, natural subsidence, and eustatic sea-level rise are major causes of threat to deltas and in many cases have compromised their safety and sustainability, putting at risk the people that live on them. In this presentation, I will introduce a framework called Delta Connectome for studying connectivity in river deltas based on different representations of a delta as a network. Here connectivity indicates both physical connectivity (how different portions of the system interact with each other) as well as conceptual (pathways of process coupling). I will explore several network representations and show how quantifying connectivity can advance our understanding of system functioning and can be used to inform coastal management and restoration. From connectivity considerations, the delta emerges as a leaky network that evolves over time and is characterized by continuous exchanges of fluxes of matter, energy, and information. I will discuss the implications of connectivity on delta functioning, land growth, and potential for nutrient removal.

Predictive value and modeling analysis of MSCT signs in gastrointestinal stromal tumors (GISTs) to pathological risk degree.

Science.gov (United States)

Wang, J-K

2017-03-01

By analyzing MSCT (multi-slice computed tomography) signs with different risks in gastrointestinal stromal tumors, this paper aimed to discuss the predictive value and modeling analysis of MSCT signs in GISTs (gastrointestinal stromal tumor) to pathological risk degree. 100 cases of primary GISTs with abdominal and pelvic MSCT scan were involved in this study. All MSCT scan findings and enhanced findings were analyzed and compared among cases with different risk degree of pathology. Then GISTs diagnostic model was established by using support vector machine (SVM) algorithm, and its diagnostic value was evaluated as well. All lesions were solitary, among which there were 46 low-risk cases, 24 medium-risk cases and 30 high-risk cases. For all high-risk, medium-risk and low-risk GISTs, there were statistical differences in tumor growth pattern, size, shape, fat space, with or without calcification, ulcer, enhancement method and peritumoral and intratumoral vessels (pvalue at each period (plain scan, arterial phase, venous phase) (p>0.05). The apparent difference lied in plain scan, arterial phase and venous phase for each risk degree. The diagnostic accuracy of SVM diagnostic model established with 10 imaging features as indexes was 70.0%, and it was especially reliable when diagnosing GISTs of high or low risk. Preoperative analysis of MSCT features is clinically significant for its diagnosis of risk degree and prognosis; GISTs diagnostic model established on the basis of SVM possesses high diagnostic value.

Solubility of hydrogen in delta iron

International Nuclear Information System (INIS)

Shapovalov, V.I.; Trofimenko, V.V.

1979-01-01

The solubility of hydrogen in iron (less than 0.002 % impurities) at temperatures of 800-1510 deg C and a pressure of 100 atm was measured. The heat of solution of hydrogen in delta-Fe, equal to 73 kJ/g-atom, is by far greater than the corresponding values for α- and γ-Fe

Delta 2.0

DEFF Research Database (Denmark)

Skott, Jeppe; Skott, Charlotte Krog; Jess, Kristine

DELTA 2.0 er en ny og helt opdateret udgave af Delta, der i ti år været brugt i matematiklærernes grund-, efter- og videreuddannelse. DELTA 2.0 er seriens almene fagdidaktik. Der er også fagdidaktiske overvejelser i de øvrige bøger i serien, men de er knyttet til specifikt matematisk indhold. DELTA...... 2.0 behandler mere generelle matematikdidaktiske problemstillinger såsom læringsteoretiske overvejelser i forbindelse med matematik, centrale aspekter af det at undervise i matematik og digitale teknologier som værktøj til at støtte elevers faglige læring af matematik....

Interval MULTIMOORA method with target values of attributes based on interval distance and preference degree: biomaterials selection

Science.gov (United States)

Hafezalkotob, Arian; Hafezalkotob, Ashkan

2017-06-01

A target-based MADM method covers beneficial and non-beneficial attributes besides target values for some attributes. Such techniques are considered as the comprehensive forms of MADM approaches. Target-based MADM methods can also be used in traditional decision-making problems in which beneficial and non-beneficial attributes only exist. In many practical selection problems, some attributes have given target values. The values of decision matrix and target-based attributes can be provided as intervals in some of such problems. Some target-based decision-making methods have recently been developed; however, a research gap exists in the area of MADM techniques with target-based attributes under uncertainty of information. We extend the MULTIMOORA method for solving practical material selection problems in which material properties and their target values are given as interval numbers. We employ various concepts of interval computations to reduce degeneration of uncertain data. In this regard, we use interval arithmetic and introduce innovative formula for interval distance of interval numbers to create interval target-based normalization technique. Furthermore, we use a pairwise preference matrix based on the concept of degree of preference of interval numbers to calculate the maximum, minimum, and ranking of these numbers. Two decision-making problems regarding biomaterials selection of hip and knee prostheses are discussed. Preference degree-based ranking lists for subordinate parts of the extended MULTIMOORA method are generated by calculating the relative degrees of preference for the arranged assessment values of the biomaterials. The resultant rankings for the problem are compared with the outcomes of other target-based models in the literature.

Peat compaction in deltas : implications for Holocene delta evolution

NARCIS (Netherlands)

van Asselen, S.

2010-01-01

Many deltas contain substantial amounts of peat, which is the most compressible soil type. Therefore, peat compaction potentially leads to high amounts of subsidence in deltas. The main objective of this research was to quantify subsidence due to peat compaction in Holocene fluvial-deltaic settings

Formation of conjugated delta8,delta10-double bonds by delta12-oleic-acid desaturase-related enzymes: biosynthetic origin of calendic acid.

Science.gov (United States)

Cahoon, E B; Ripp, K G; Hall, S E; Kinney, A J

2001-01-26

Divergent forms of the plant Delta(12)-oleic-acid desaturase (FAD2) have previously been shown to catalyze the formation of acetylenic bonds, epoxy groups, and conjugated Delta(11),Delta(13)-double bonds by modification of an existing Delta(12)-double bond in C(18) fatty acids. Here, we report a class of FAD2-related enzymes that modifies a Delta(9)-double bond to produce the conjugated trans-Delta(8),trans-Delta(10)-double bonds found in calendic acid (18:3Delta(8trans,10trans,12cis)), the major component of the seed oil of Calendula officinalis. Using an expressed sequence tag approach, cDNAs for two closely related FAD2-like enzymes, designated CoFADX-1 and CoFADX-2, were identified from a C. officinalis developing seed cDNA library. The deduced amino acid sequences of these polypeptides share 40-50% identity with those of other FAD2 and FAD2-related enzymes. Expression of either CoFADX-1 or CoFADX-2 in somatic soybean embryos resulted in the production of calendic acid. In embryos expressing CoFADX-2, calendic acid accumulated to as high as 22% (w/w) of the total fatty acids. In addition, expression of CoFADX-1 and CoFADX-2 in Saccharomyces cerevisiae was accompanied by calendic acid accumulation when induced cells were supplied exogenous linoleic acid (18:2Delta(9cis,12cis)). These results are thus consistent with a route of calendic acid synthesis involving modification of the Delta(9)-double bond of linoleic acid. Regiospecificity for Delta(9)-double bonds is unprecedented among FAD2-related enzymes and further expands the functional diversity found in this family of enzymes.

Role of delta excitations in pion-, photon- and nucleon-nucleus reactions studied with microscopic models

International Nuclear Information System (INIS)

Engel, A.

1995-01-01

Delta excitation plays a prominent role in intermediate heavy reactions. In this paper, comment is made on the calculations done for pion-, photon- and nucleon-nucleus reactions using the Boltzmann-Uehling-Uhlenbeck (BUU) model and the antisymmetrized molecular dynamics (AMD) model. First, it is recalled how to include delta degrees in microscopic models in general. Then, the comparison of the microscopic calculation performed by the author with the experimental data is presented. Deltas in microscopic models are discussed. Pion-nucleus reactions have been studied since pion beams became available, especially for exploring the delta resonance in a nuclear medium. The dependence of pion absorption cross section on incident pion energy is shown. The photon-induced pion production in the resonance energy region was studied with the BUU model. The calculated results of neutral pion photo-production are shown. In both inelastic proton scattering and (p,n) charge exchange reaction, the excitation of delta resonance can be observed clearly in the experimental data. The results of the AMD calculation for 12 C(p,p') reaction are shown. (K.I.)

Stable computation of generalized singular values

Energy Technology Data Exchange (ETDEWEB)

Drmac, Z.; Jessup, E.R. [Univ. of Colorado, Boulder, CO (United States)

1996-12-31

We study floating-point computation of the generalized singular value decomposition (GSVD) of a general matrix pair (A, B), where A and B are real matrices with the same numbers of columns. The GSVD is a powerful analytical and computational tool. For instance, the GSVD is an implicit way to solve the generalized symmetric eigenvalue problem Kx = {lambda}Mx, where K = A{sup {tau}}A and M = B{sup {tau}}B. Our goal is to develop stable numerical algorithms for the GSVD that are capable of computing the singular value approximations with the high relative accuracy that the perturbation theory says is possible. We assume that the singular values are well-determined by the data, i.e., that small relative perturbations {delta}A and {delta}B (pointwise rounding errors, for example) cause in each singular value {sigma} of (A, B) only a small relative perturbation {vert_bar}{delta}{sigma}{vert_bar}/{sigma}.

A reexamination of cellulose carbon-bound hydrogen deltaD measurements and some factors affecting plant-water D/H relationships

International Nuclear Information System (INIS)

Yapp, C.J.; Epstein, S.

1982-01-01

The method of Epstein et al. (1976) for analysis of D/H ratios of cellulose carbon-bound hydrogen has been modified. This modified 'renitration' method yields deltaD values which are in agreement with those obtained by the sodium chlorite delignification method. Comparison of results obtained by the renitration method with the published results of Epstein et al. indicate some differences in the deltaD values of individual samples. However, the overall plant-water deltaD relationship determined by Epstein et al., is not greatly changed upon redetermination by the renitration method. Additional data from a variety of plants representing a wide geographical range reveal that relative humidity is an important variable in determining the deltaD value of cellulose C-H hydrogen on this inter-regional scale. The role of relative humidity can be reasonably explained by a leaf water model that assumes an isotopic steady-state during transpiration. These results reaffirm the conclusion of Epstein et al., that the deltaD variations of the source water are the dominant control of the deltaD variations of cellulose C-H hydrogen from naturally grown plants. Thus, there is an expectation that these cellulose deltaD variations can have climate significance. (author)

Large-scale coastal and fluvial models constrain the late Holocene evolution of the Ebro Delta

Directory of Open Access Journals (Sweden)

J. H. Nienhuis

2017-09-01

Full Text Available The distinctive plan-view shape of the Ebro Delta coast reveals a rich morphologic history. The degree to which the form and depositional history of the Ebro and other deltas represent autogenic (internal dynamics or allogenic (external forcing remains a prominent challenge for paleo-environmental reconstructions. Here we use simple coastal and fluvial morphodynamic models to quantify paleo-environmental changes affecting the Ebro Delta over the late Holocene. Our findings show that these models are able to broadly reproduce the Ebro Delta morphology, with simple fluvial and wave climate histories. Based on numerical model experiments and the preserved and modern shape of the Ebro Delta plain, we estimate that a phase of rapid shoreline progradation began approximately 2100 years BP, requiring approximately a doubling in coarse-grained fluvial sediment supply to the delta. River profile simulations suggest that an instantaneous and sustained increase in coarse-grained sediment supply to the delta requires a combined increase in both flood discharge and sediment supply from the drainage basin. The persistence of rapid delta progradation throughout the last 2100 years suggests an anthropogenic control on sediment supply and flood intensity. Using proxy records of the North Atlantic Oscillation, we do not find evidence that changes in wave climate aided this delta expansion. Our findings highlight how scenario-based investigations of deltaic systems using simple models can assist first-order quantitative paleo-environmental reconstructions, elucidating the effects of past human influence and climate change, and allowing a better understanding of the future of deltaic landforms.

A New Similarity Measure of Interval-Valued Intuitionistic Fuzzy Sets Considering Its Hesitancy Degree and Applications in Expert Systems

Directory of Open Access Journals (Sweden)

Chong Wu

2014-01-01

Full Text Available As an important content in fuzzy mathematics, similarity measure is used to measure the similarity degree between two fuzzy sets. Considering the existing similarity measures, most of them do not consider the hesitancy degree and some methods considering the hesitancy degree are based on the intuitionistic fuzzy sets, intuitionistic fuzzy values. It may cause some counterintuitive results in some cases. In order to make up for the drawback, we present a new approach to construct the similarity measure between two interval-valued intuitionistic fuzzy sets using the entropy measure and considering the hesitancy degree. In particular, the proposed measure was demonstrated to yield a similarity measure. Besides, some examples are given to prove the practicality and effectiveness of the new measure. We also apply the similarity measure to expert system to solve the problems on pattern recognition and the multicriteria group decision making. In these examples, we also compare it with existing methods such as other similarity measures and the ideal point method.

The influence of the heat treatment on delta ferrite transformation in austenitic stainless steel welds

Directory of Open Access Journals (Sweden)

B. Mateša

2012-04-01

Full Text Available Shielded metal arc (SMAW welded specimens using austenitic consumable materials with different amount of delta-ferrite are annealed in range 650-750 °C through 2-10 hours. Factorial plan 33 with influenced factors regression analyze of measured delta-ferrite values is used. The transformation i.e. decomposition of delta ferrite during annealing was analyzed regarding on weld cracking resistance using metallographic examination and WRC-1992 diagram.

$\\delta$-Expansion at Finite Temperature

OpenAIRE

Ramos, Rudnei O.

1996-01-01

We apply the $\\delta$-expansion perturbation scheme to the $\\lambda \\phi^{4}$ self-interacting scalar field theory in 3+1 D at finite temperature. In the $\\delta$-expansion the interaction term is written as $\\lambda (\\phi^{2})^{ 1 + \\delta}$ and $\\delta$ is considered as the perturbation parameter. We compute within this perturbative approach the renormalized mass at finite temperature at a finite order in $\\delta$. The results are compared with the usual loop-expansion at finite temperature.

Rise and Fall of one of World's largest deltas; the Mekong delta in Vietnam

Science.gov (United States)

Minderhoud, P. S. J.; Eslami Arab, S.; Pham, H. V.; Erkens, G.; van der Vegt, M.; Oude Essink, G.; Stouthamer, E.; Hoekstra, P.

2017-12-01

The Mekong delta is the third's largest delta in the world. It is home to almost 20 million people and an important region for the food security in South East Asia. As most deltas, the Mekong delta is the dynamic result of a balance of sediment supply, sea level rise and subsidence, hosting a system of fresh and salt water dynamics. Ongoing urbanization, industrialization and intensification of agricultural practices in the delta, during the past decades, resulted in growing domestic, agricultural and industrial demands, and have led to a dramatic increase of fresh water use. Since the year 2000, the amount of fresh groundwater extracted from the subsurface increased by 500%. This accelerated delta subsidence as the groundwater system compacts, with current sinking rates exceeding global sea level rise up to an order of magnitude. These high sinking rates have greatly altered the sediment budget of the delta and, with over 50% of the Mekong delta surface elevated less than 1 meter above sea level, greatly increase vulnerability to flooding and storm surges and ultimately, permanent inundation. Furthermore, as the increasingly larger extractions rapidly reduce the fresh groundwater reserves, groundwater salinization subsequently increases. On top of that, dry season low-flows by the Mekong river cause record salt water intrusion in the delta's estuarine system, creating major problems for rice irrigation. We present the work of three years research by the Dutch-Vietnamese `Rise and Fall' project on land subsidence and salinization in both groundwater and surface water in the Vietnamese Mekong delta.

Losing ground in mega-deltas: basin-scale response to existential threats to the Mekong Delta

Science.gov (United States)

Arias, M. E.; Kondolf, G. M.; Schmitt, R. J. P.; Carling, P. A.; Darby, S. E.; Bizzi, S.; Castelletti, A.; Cochrane, T. A.; Gibson, S.; Kummu, M.; Oeurng, C.; Rubin, Z.; Wild, T. B.

2017-12-01

The Mekong Delta is, in terms of the number of livelihoods it supports, its economic importance, and in its vulnerability to climate change and sinking lands, one of the world's critically threatened mega-deltas. Livelihoods depend on the mere existence of the delta, but also on ecosystem services provided by the delta's drainage basin spanning 795,000 km2 in six abutting countries. These ecosystem services include delivery of sand required to build delta land in the face of rising sea-levels and sediment bound nutrients, provision of spawning habitat for fish that are ultimately harvested in the delta, and hydrologic regulation driving the delta's unique flood-pulse regime. However, while the delta is mainly located in Vietnam, the basin of the Mekong River is shared among China, Myanmar, Laos, Thailand, Cambodia, and Vietnam. In the context of the region's dynamic growth, individual countries are pushing their own development agendas, which include extensive dam building, in-channel sand mining, construction of dykes and canals, and groundwater pumping, all of which contribute to subsidence and erosion of the Delta. Our synthesis of recent research indicates that most of the Mekong's delta land will likely fall below sea-level by 2100 as result of these drivers, exacerbating the impacts of global climatic changes. In this context, local infrastructural projects and changes in land- and water-management may temporarily mitigate some negative effects, but do not address the existential threat to the delta as a whole. To prevent, or at least substantially postpone, the drowning of the Mekong Delta requires identification of the key drivers and immediate concerted management actions on the basin-scale to change the trajectory of subsidence and sediment deficit. A specific challenge is to find the institutional arrangements in this transnational context that could support the needed management changes and equitably distribute costs and impacts. The Mekong Delta is

Effect mechanism of air deflectors on the cooling performance of dry cooling tower with vertical delta radiators under crosswind

International Nuclear Information System (INIS)

Zhao, Yuanbin; Long, Guoqing; Sun, Fengzhong; Li, Yan; Zhang, Cuijiao; Liu, Jiabin

2015-01-01

Highlights: • A 3D numerical model was set for NDDCTV to study the effect of air deflectors. • The air deflectors improve the tower performance by 1.375 °C at u c = 6 m/s for a case. • The air deflectors reduce the air inflow deviation angle θ d at most delta entries. • The reduced θ d can improve the cooling performance of former deteriorated columns. • Both the radial inflow air velocity and θ d impact the cooling performance of delta. - Abstract: To study the effect mechanism of air deflectors on dry cooling tower, a three dimensional numerical model was established, with full consideration of the delta structure. The accuracy and credibility of dry cooling tower numerical model were validated. By numerical model, the average air static pressure and the average radial inflow air velocity were computed and analyzed at delta air entry, sector air entry and exit faces. By the air inflow deviation angle θ d , the effect of air deflectors on the aerodynamic field around tower was analyzed. The water exit temperatures of θ −1 columns, θ +2 columns and cooling sectors were also presented to clarify the effect of air deflectors. It was found that the air deflectors improved the aerodynamic field around cooling columns. The reduced air inflow deviation degree at delta entry improved the cooling performance of deteriorated columns. Referring to the radial inflow air velocity u ra and the air inflow deviation degree at delta entry, the effect mechanism of air deflectors are clarified under crosswind

Assessment value of quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer

Directory of Open Access Journals (Sweden)

Jiang-Xia Lei

2016-10-01

Full Text Available Objective: To analyze the assessment value of the quantitative indexes of pancreatic CT perfusion scanning for malignant degree of pancreatic cancer. Methods: A total of 58 patients with space-occupying pancreatic lesions were divided into 20 patients with pancreatic cancer and 38 patients with benign pancreatic lesions after pancreatic CT perfusion. Patients with pancreatic cancer received palliative surgery, and the cancer tissue and para-carcinoma tissue specimens were collected during operation. The differences in pancreatic CT perfusion scanning parameter values and serum tumor marker levels were compared between patients with pancreatic cancer and patients with benign pancreatic lesions, mRNA expression levels of malignant molecules in pancreatic cancer tissue and para-carcinoma tissue were further determined, and the correlation between pancreatic CT perfusion scanning parameter values and malignant degree of pancreatic cancer was analyzed. Results: CT perfusion scanning BF, BV and Per values of patients with pancreatic cancer were lower than those of patients with benign pancreatic lesions; serum CA19-9, CEA, CA125 and CA242 levels were higher than those of patients with benign pancreatic lesions (P<0.05; mRNA expression levels of Bcl-2, Bcl-xL and survivin in pancreatic cancer tissue samples were higher than those in paracarcinoma tissue samples, and mRNA expression levels of P53 and Bax were lower than those in para-carcinoma tissue samples (P<0.05; CT perfusion scanning parameters BF, BV and Per values of patients with pancreatic cancer were negatively correlated with CA19-9, CEA, CA125 and CA242 levels in serum as well as mRNA expression levels of Bcl-2, Bcl-xL and survivin in pancreatic cancer tissue, and positively correlated with mRNA expression levels of P53 and Bax in pancreatic cancer tissue (P<0.05. Conclusions: Pancreatic CT perfusion scanning is a reliable way to judge the malignant degree of pancreatic cancer and plays a

Ecosystem Service Value for the Common Reed Wetlands in the Liaohe Delta, Northeast China

DEFF Research Database (Denmark)

Ye, Siyuan; Laws, Edward A.; Costanza, Robert

2016-01-01

The largest reed field in the world, with an area of 1000 km2 in 1953, is located in the Liaohe Delta, which lies in the five-point-in-a-line economic strategic zone of northeastern China. However, the area of reeds has declined dramatically in recent years to accommodate oil field infrastructure...

Reconstruction of past variations of (delta)13C in atmospheric CO2 from i vertical distribution observed in the firn at Dome Fuji, Antarctica

International Nuclear Information System (INIS)

Sugawara, S.

2003-01-01

Temporal variations of (delta) 13 C of atmospheric CO 2 in the past have been reconstructed from the (delta) 13 C values of CO 2 observed in firn at Dome Fuji, Antarctica. The effective diffusivities of CO 2 in firn were estimated for Dome Fuji and another Antarctic site, H72. The age distributions of 13 CO 2 in firn were first calculated by using a one-dimensional diffusion model, and then the past values of the atmospheric (delta) 13 C were derived by using an iterative procedure so that the calculated and observed vertical profiles of (delta) 13 C of CO 2 in firn agreed with each other. This reconstruction method was also applied to the CH 4 concentration to confirm its validity. The values of the atmospheric (delta) 13 C thus estimated were in good agreement with those from direct atmospheric measurements at Syowa Station, Antarctica, even for the levelling off of the secular decrease observed in the first half of the 1990s. The statistical uncertainty of the iterative procedure was examined by adding normal pseudo-random numbers to the observed (delta) 13 C values in firn. We also calculated the (delta) 13 C values for firn at H72 using the reconstructed history of the atmospheric (delta) 13 C, and its vertical profile was found to be in close agreement with the observational result

Correlation of infrared reflectance ratios at 2.3 microns/1.6 micron and 1.1 micron/1.6 micron with delta O-18 values delineating fossil hydrothermal systems in the Idaho batholith

Science.gov (United States)

Gillespie, A. R.; Criss, R. E.

1983-01-01

Reflectance ratios from laboratory spectra and airborne multispectral images are found to be strongly correlated with delta O-18 values of granite rocks in the Idaho batholith. The correlation is largely a result of interactions between hot water and rock, which lowered the delta O-18 values of the rocks and produced secondary hydrous material. Maps of the ratio of reflectivities at 2.3 and 1.6 microns should delineate fossil hydrothermal systems and provide estimates of alteration intensity. However, hydrous minerals produced during deuteric alteration or weathering cannot be unambiguously distinguished in remotely sensed images from the products of propylitic alteration without the use of narrow-band scanners. The reflectivity at 1.6 micron is strongly correlated with rock density and may be useful in distinguishing rock types in granitic terranes.

Deltas on the move. Making deltas cope with the effects of climate change

International Nuclear Information System (INIS)

Reker, J.; Van Winden, A.; Braakhekke, W.; Vermaat, J.; Eleveld, M.; Janssen, R.; De Reus, N.; Omzigt, N.

2006-01-01

This scoping study is the first phase of a study aimed at: (a) providing knowledge on the potential of a system-based approach to deal with the effects of climate change as an alternative for the more traditional technical measures such as dams, dikes and surge barriers. This should be shown for both rich and poor countries and should address hydrological, ecological as well as socio-economic aspects; and (b) identifying the potential to market these results worldwide. To reach these objectives four research steps are defined: (1) to make an inventory of deltas: their vulnerability to the effects of climate change; (2) development of indicators for successful use of a system-based approach; (3) to provide an overview of the potential of soft measures for these deltas; (4) to select a number of deltas with potential for marketing system-based measures and the development of strategies to link economic and ecological objectives. This scoping study addresses step 1 only. The results from step 1 will be used as a starting point for steps 2 and 3. The outputs of this scoping study are threefold: a background report (this report); a flyer with a brief description of the findings; a website with information on delta's and how these may be affected by climate change. The scoping study will roughly outline which deltas are still functioning in a more or less natural manner - or could be (re)developed in that direction - and thus would be good candidates for a system-based approach. Chapter 2 gives a description of the geomorphological and ecological processes in a delta. In addition, those aspects of climate change that can have an effect on deltas are described. The third chapter deals with human interventions in deltas and whether or not they fit within a system-based approach. In a system-based approach, as presented in Chapter 4, natural processes are given free reign where possible. Chapter 5 shows how available data on deltas could be used in such a system

(D-Pen2,4 prime -125I-Phe4,D-Pen5)enkephalin: A selective high affinity radioligand for delta opioid receptors with exceptional specific activity

Energy Technology Data Exchange (ETDEWEB)

Knapp, R.J.; Sharma, S.D.; Toth, G.; Duong, M.T.; Fang, L.; Bogert, C.L.; Weber, S.J.; Hunt, M.; Davis, T.P.; Wamsley, J.K. (Department of Pharmacology, University of Arizona, College of Medicine, Tucson (United States))

1991-09-01

(D-Pen2,4{prime}-125I-Phe4,D-Pen5)enkephalin ((125I)DPDPE) is a highly selective radioligand for the delta opioid receptor with a specific activity (2200 Ci/mmol) that is over 50-fold greater than that of tritium-labeled DPDPE analogs. (125I)DPDPE binds to a single site in rat brain membranes with an equilibrium dissociation constant (Kd) value of 421 {plus minus} 67 pM and a receptor density (Bmax) value of 36.4 {plus minus} 2.7 fmol/mg protein. The high affinity of this site for delta opioid receptor ligands and its low affinity for mu or kappa receptor-selective ligands are consistent with its being a delta opioid receptor. The distribution of these sites in rat brain, observed by receptor autoradiography, is also consistent with that of delta opioid receptors. Association and dissociation binding kinetics of 1.0 nM (125I) DPDPE are monophasic at 25 degrees C. The association rate (k + 1 = 5.80 {plus minus} 0.88 {times} 10(7) M-1 min-1) is about 20- and 7-fold greater than that measured for 1.0 nM (3H) DPDPE and 0.8 nM (3H) (D-Pen2,4{prime}-Cl-Phe4, D-Pen5)enkephalin, respectively. The dissociation rate of (125I)DPDPE (0.917 {plus minus} 0.117 {times} 10(-2) min-1) measured at 1.0 nM is about 3-fold faster than is observed for either of the other DPDPE analogs. The rapid binding kinetics of (125I)DPDPE is advantageous because binding equilibrium is achieved with much shorter incubation times than are required for other cyclic enkephalin analogs. This, in addition to its much higher specific activity, makes (125I)DPDPE a valuable new radioligand for studies of delta opioid receptors.

Tides Stabilize Deltas until Humans Interfere

Science.gov (United States)

Hoitink, T.; Zheng Bing, W.; Vermeulen, B.; Huismans, Y.; Kastner, K.

2017-12-01

Despite global concerns about river delta degradation caused by extraction of natural resources, sediment retention by reservoirs and sea-level rise, human activity in the world's largest deltas intensifies. In this review, we argue that tides tend to stabilize deltas until humans interfere. Under natural circumstances, delta channels subject to tides are more stable than their fluvial-dominated counterparts. The oscillatory tidal flow counteracts the processes responsible for bank erosion, which explains why unprotected tidal channels migrate only slowly. Peak river discharges attenuate the tides, which creates storage space to accommodate the extra river discharge during extreme events and as a consequence, reduce flood risk. With stronger tides, the river discharge is being distributed more evenly over the various branches in a delta, preventing silting up of smaller channels. Human interference in deltas is massive. Storm surge barriers are constructed, new land is being reclaimed and large-scale sand excavation takes place, to collect building material. Evidence from deltas around the globe shows that in human-controlled deltas the tidal motion often plays a destabilizing role. In channels of the Rhine-Meuse Delta, some 100 scour holes are identified, which relates to the altered tidal motion after completion of a storm surge barrier. Sand mining has led to widespread river bank failures in the tidally-influenced Mekong Delta. The catastrophic flood event in the Gauges-Brahmaputra Delta by Cyclone Aila, which caused the inundation of an embanked polder area for over two years, was preceded by river bank erosion at the mouths of formal tidal channels that were blocked by the embankment. Efforts to predict the developments of degrading deltas are few. Existing delta models are capable of reproducing expanding deltas, which is essentially a matter of simulating the transport of sediment from source in a catchment to the sink in a delta. Processes of soil

Changes in concentration and (delta) 13C value of dissolved CH4, CO2 and organic carbon in rice paddies under ambient and elevated concentrations of atmospheric CO2

International Nuclear Information System (INIS)

Weiguo Cheng; Yagi, Kazuyuki; Sakai, Hidemitsu; Hua Xu; Kobayashi, Kazuhiko

2005-01-01

Changes in concentration and (delta) 13 C value of dissolved CH 4 , CO 2 and organic carbon (DOC) in floodwater and soil solution from a Japanese rice paddy were studied under ambient and elevated concentrations of atmospheric CO 2 in controlled environment chambers. The concentrations of dissolved CH 4 in floodwater increased with rice growth (with some fluctuation), while the concentrations of CO 2 remained between 2.9 to 4.4 and 4.2 to 5.8 μg C mL -1 under conditions of ambient and elevated CO 2 concentration, respectively. The amount of CH 4 dissolved in soil solution under elevated CO 2 levels was significantly lower than under ambient CO 2 in the tillering stage, implying that the elevated CO 2 treatment accelerated CH 4 oxidation during the early stage of growth. However, during later stages of growth, production of CH 4 increased and the amount of CH 4 dissolved in soil solution under elevated CO 2 levels was, on average, greater than that under ambient CO 2 conditions. Significant correlation existed among the (delta) 13 C values of dissolved CH 4 , CO 2 , and DOC in floodwater (except for the samples taken immediately after pulse feeding with 13 C enriched CO 2 ), indicating that the origins and cycling of CH 4 , CO 2 and DOC were related. There were also significant correlations among the (delta) 13 C values of CH 4 , CO 2 and DOC in the soil solution. The turnover rate of CO 2 in soil solution was most rapid in the panicle formation stage of rice growth and that of CH 4 fastest in the grain filling stage. (Author)

delta 13C analyses of vegetable oil fatty acid components, determined by gas chromatography--combustion--isotope ratio mass spectrometry, after saponification or regiospecific hydrolysis.

Science.gov (United States)

Woodbury, S E; Evershed, R P; Rossell, J B

1998-05-01

The delta 13C values of the major fatty acids of several different commercially important vegetable oils were measured by gas chromatography--combustion--isotope ratio mass spectrometry. The delta 13C values obtained were found to fall into two distinct groups, representing the C3 and C4 plants classes from which the oils were derived. The delta 13C values of the oils were measured by continuous flow elemental isotope ratio mass spectrometry and were found to be similar to their fatty acids, with slight differences between individual fatty acids. Investigations were then made into the influence on the delta 13C values of fatty acids of the position occupied on the glycerol backbone. Pancreatic lipase was employed to selectively hydrolyse fatty acids from the 1- and 3-positions with the progress of the reaction being followed by high-temperature gas chromatography in order to determine the optimum incubation time. The 2-monoacylglycerols were then isolated by thin-layer chromatography and fatty acid methyl esters prepared. The delta 13C values obtained indicate that fatty acids from any position on the glycerol backbone are isotopically identical. Thus, whilst quantification of fatty acid composition at the 2-position and measurement of delta 13C values of oils and their major fatty acids are useful criteria in edible oil purity assessment, measurement of delta 13C values of fatty acids from the 2-position does not assist with oil purity assignments.

In vivo metabolism of the methyl homologues of delta-8-tetrahydrocannabinol, delta-9-tetrahydrocannabinol and abn-delta-8-tetrahydrocannabinol in the mouse.

Science.gov (United States)

Brown, N K; Harvey, D J

1988-04-01

Methyl-delta-8-tetrahydrocannabinol (methyl-delta-8-THC), methyl-delta-9-THC and abn-methyl-delta-8-THC were synthesized by condensation of orcinol and (1S)-cis-verbenol and were administered to male Charles River CD-1 mice. Extracted hepatic metabolites were isolated by chromatography on Sephadex LH-20 and examined by gas chromatography/mass spectrometry as trimethylsilyl (TMS), (2H9)TMS and methyl ester/TMS derivatives. In addition, metabolic fractions were reduced with lithium aluminium deuteride to convert carboxylic acids to alcohols for structural correlation. Metabolites from methyl-delta-8-THC were similar with respect to the positions substituted to those produced by higher homologues; the major metabolite was methyl-delta-8-THC-11-oic acid. abn-Methyl-delta-8-THC was metabolized in a different manner. The location of the aromatic methyl group at the position adjacent to ring fusion appeared to inhibit metabolism at C(11) to a considerable extent and also to reduce the amount of the resulting alcohol from being oxidized to a carboxylic acid. This caused other metabolic pathways to become dominant, with the result that a compound containing a hydroxy group at the gem-methyl position was the major metabolite. Hydroxylation at this position has not been confirmed with any other cannabinoid, although it is thought to result in trace concentrations of hydroxy metabolites from some compounds. Metabolism of methyl-delta-9-THC was also similar to that of the higher homologues, with the exception that less metabolism occurred at C(8) and a higher percentage of the total metabolic fraction was accounted for by the 11-oic acid metabolite. Minor metabolites were mainly dihydroxy compounds and hydroxylated derivatives of delta-9-THC-11-oic acid.

An Implementation Of Elias Delta Code And ElGamal Algorithm In Image Compression And Security

Science.gov (United States)

Rachmawati, Dian; Andri Budiman, Mohammad; Saffiera, Cut Amalia

2018-01-01

In data transmission such as transferring an image, confidentiality, integrity, and efficiency of data storage aspects are highly needed. To maintain the confidentiality and integrity of data, one of the techniques used is ElGamal. The strength of this algorithm is found on the difficulty of calculating discrete logs in a large prime modulus. ElGamal belongs to the class of Asymmetric Key Algorithm and resulted in enlargement of the file size, therefore data compression is required. Elias Delta Code is one of the compression algorithms that use delta code table. The image was first compressed using Elias Delta Code Algorithm, then the result of the compression was encrypted by using ElGamal algorithm. Prime test was implemented using Agrawal Biswas Algorithm. The result showed that ElGamal method could maintain the confidentiality and integrity of data with MSE and PSNR values 0 and infinity. The Elias Delta Code method generated compression ratio and space-saving each with average values of 62.49%, and 37.51%.

Delta Evolution at Røde Elv, Disko Island, Greenland

Science.gov (United States)

Kroon, A.; Arngrimson, J.; Bendixen, M.; Sigsgaard, C.

2017-12-01

Ice, snow and freezing temperatures have a large impact on coastal morphodynamics in Arctic polar environments. A recent warming of the Arctic climate induces many changes along the arctic shorelines. Sea-levels are rising due to thermal expansion and due to an increased fresh water flux from the glaciers and land ice masses. At the same time, the ice coverage of the coastal waters reduces and the open water periods in summer extend. There is a strong seasonal variation with open waters and active rivers in summer and ice-covered coastal waters and inactive rivers in winter. Coastal processes by waves and tides are thus limited to the summer and early fall. Besides, there is also a strong daily variation in fluvial discharges due to the daily variations in glacier melt with maximum melt in the afternoon and minimum values at night. At the same time, the actual flux of the river to the coastal bay is influenced by the tidal phase. Low tides will enhance the transport to the delta front, while high tides will create stagnant waters over the delta plain. The delta of the Røde Elv is located in southwestern Disko Island in west Greenland. It has a relatively small (ca. 101 km2) and partly glaciated drainage basin (ca. 20%) and its sediments consist of a mixture of basaltic sands and gravels. The Røde Elv delta is located at the end of a pro-glacial and fluvial valley at about 20 km from the glacier. The shores of the delta are reworked by waves, predominantly from southwestern, southern (largest fetch, over 50 km), and southeastern directions. The environment has a micro- to meso- tidal range with a spring tidal range of 2.7 m. The morphologic changes on the delta over the last decades clearly showed a seaward extension of the delta and a periodic shift in the location of the main delta channel. In this presentation, we focus on quantification of water discharges and suspended sediment fluxes to the Røde Elv delta in western Greenland, and on the morphological

Phenotypic expressions of CCR5-Delta 32/Delta 32 homozygosity

NARCIS (Netherlands)

Nguyen, GT; Carrington, M; Beeler, JA; Dean, M; Aledort, LM; Blatt, PM; Cohen, AR; DiMichele, D; Eyster, ME; Kessler, CM; Konkle, B; Leissinger, C; Luban, N; O'Brien, SJ; Goedert, JJ; O'Brien, TR

1999-01-01

Objective: As blockade of CC-chemokine receptor 5 (CCR5) has been proposed as therapy for HIV-1, we examined whether the CCR5-Delta 32/Delta 32 homozygous genotype has phenotypic expressions other than those related to HIV-1. Design: Study subjects were white homosexual men or men with hemophilia

C4 plant isotopic composition ((delta)13C) evidence for urban CO2 pollution in the city of Cotonou, Benin (West Africa)

International Nuclear Information System (INIS)

Kelome, Nelly C.; Leveque, Jean; Andreux, Francis; Milloux, Marie-Jeanne; Oyede, Lucien-Marc

2006-01-01

The carbon isotopic composition ((delta) 13 C) of plants can reveal the isotopic carbon content of the atmosphere in which they develop. The (delta) 13 C values of air and plants depend on the amount of atmospheric fossil fuel CO 2 , which is chiefly emitted in urban areas. A new indicator of CO 2 pollution is tested using the (delta) 13 C variation in a C 4 grass: Eleusine indica. A range of about 4%% delta units was observed at different sites in Cotonou, the largest city in the Republic of Benin. The highest (delta) 13 C values, from -12%% to -14%%, were found in low traffic zones; low (delta) 13 C values, from -14%% to -16%%, were found in high traffic zones. The amount of fossil fuel carbon assimilated by plants represented about 20% of the total plant carbon content. An overall decrease in plant (delta) 13 C values was observed over a four-year monitoring period. This decrease was correlated with increasing vehicle traffic. The (delta) 13 C dataset and the corresponding geographical database were used to map and define zones of high and low 13 C-depleted CO 2 emissions in urban and sub-urban areas. The spatial distribution follows dominant wind directions, with the lowest emission zones found in the southwest of Cotonou. High CO 2 emissions occurred in the north, the east and the center, providing evidence of intense anthropogenic activity related to industry and transportation. (author)

Clinical value of acoustic radiation force impulse in quantitative prediction of the degree of esophageal varices in patients with liver cirrhosis

Directory of Open Access Journals (Sweden)

CHEN Min

2018-01-01

Full Text Available Objective To investigate the clinical value of acoustic radiation force impulse (ARFI in quantitative prediction of the degree of esophageal varices in patients with cirrhotic portal hypertension. Methods A total of 116 patients with liver cirrhosis who were admitted to 302 Hospital of PLA from October 2014 to February 2016 were enrolled. ARFI was used to measure real-time liver and spleen stiffness for all patients. With the degree of esophageal varices determined by gastroscopy as the gold standard for diagnosis, these patients were divided into non-varices group (EV0, 16 patients, mild varices group (EV1, 39 patients, moderate varices group (EV2, 26 patients, and severe varices group (EV3, 35 patients. The receiver operating characteristic (ROC curve was used to analyze the clinical value of liver/spleen ARFI in predicting the degree of esophageal varices. An analysis of variance or the Kruskal-Wallis H test was used for comparison of continuous data between multiple groups, and the least significant difference Mann-Whitney U test was used for further comparison between any two groups; the chi-square test was used for comparison of categorical data between groups. The Spearman correlation analysis was used to investigate the correlation between the stiffness measured by ARFI and the degree of esophageal varices. Results The ARFI value of the spleen was 2.54±0.34 m/s for EV0 patients, 3.05±0.34 m/s for EV1 patients, 3.48±0.50 m/s for EV2 patients, and 3.69±0.33 m/s for EV3 patients (χ2=60.121,P＜0.001. The ARFI value of the spleen was positively correlated with the grade of esophageal varices (r=0.713, P＜0.001. The areas under the ROC curve for the ARFI value of the spleen in the diagnosis of ≥EV1, ≥EV2, or EV3 esophageal varices were 0.93, 0.88, and 0.83, respectively. There was no significant difference in the ARFI value of the liver between groups (P=0.085, and the ARFI value of the liver was not correlated with the degree of

Recent foraminifera of the Sao Francisco river delta, Sergipe, Brazil: a proposal for the ecological and environmental diagnostic model; Foraminiferos recentes do delta do Rio Sao Francisco, Sergipe (Brasil): uma proposta de modelo ecologico e de diagnostico ambiental

Energy Technology Data Exchange (ETDEWEB)

NONE

2003-07-01

Recent foraminifera assemblages were studied to determine an ecological model of species distribution, diversity, equability and confining degree, with implications to environmental diagnosis and paleoenvironmental reconstructions. The study area is inserted in a sector from Sao Francisco River delta, with interconnected channels and a lagoon connected to the ocean. Besides the biotic variables, sediment salinity and granulometry was considered. An agglomerative hierarchical clustering (AHC) was performed and it was recognized three bio facies distributed along the sector: Miliammina/Arenoparrella in the channels, and Ammonia/Elphidium and Quinqueloculina at the lagoon. The diversity and equability values increase from the Miliammina/Arenoparrella biofacies to the Ammonia/Elphidium and Quinqueloculina biofacies. The confining indices show environments ranging from confined (channels) to different degrees of low restricted to marine influence. From the results obtained, it is possible to recognize that environments dominated by textulariines are characterized by low diversity, equability and high confining degree. Environments dominated by rotaliines and miliolines tend to be more diversified, equitable and low restricted to marine influence. The results are similar to other obtained in other Brazilian estuarine environments, differing only on dominance by some species (author)

Migration in Deltas: An Integrated Analysis

Science.gov (United States)

Nicholls, Robert J.; Hutton, Craig W.; Lazar, Attila; Adger, W. Neil; Allan, Andrew; Arto, Inaki; Vincent, Katharine; Rahman, Munsur; Salehin, Mashfiqus; Sugata, Hazra; Ghosh, Tuhin; Codjoe, Sam; Appeaning-Addo, Kwasi

2017-04-01

Deltas and low-lying coastal regions have long been perceived as vulnerable to global sea-level rise, with the potential for mass displacement of exposed populations. The assumption of mass displacement of populations in deltas requires a comprehensive reassessment in the light of present and future migration in deltas, including the potential role of adaptation to influence these decisions. At present, deltas are subject to multiple drivers of environmental change and often have high population densities as they are accessible and productive ecosystems. Climate change, catchment management, subsidence and land cover change drive environmental change across all deltas. Populations in deltas are also highly mobile, with significant urbanization trends and the growth of large cities and mega-cities within or adjacent to deltas across Asia and Africa. Such migration is driven primarily by economic opportunity, yet environmental change in general, and climate change in particular, are likely to play an increasing direct and indirect role in future migration trends. The policy challenges centre on the role of migration within regional adaptation strategies to climate change; the protection of vulnerable populations; and the future of urban settlements within deltas. This paper reviews current knowledge on migration and adaptation to environmental change to discern specific issues pertinent to delta regions. It develops a new integrated methodology to assess present and future migration in deltas using the Volta delta in Ghana, Mahanadi delta in India and Ganges-Brahmaputra-Meghna delta across India and Bangladesh. The integrated method focuses on: biophysical changes and spatial distribution of vulnerability; demographic changes and migration decision-making using multiple methods and data; macro-economic trends and scenarios in the deltas; and the policies and governance structures that constrain and enable adaptation. The analysis is facilitated by a range of

Cerebral correlates of delta waves during non-REM sleep revisited.

Science.gov (United States)

Dang-Vu, Thien Thanh; Desseilles, Martin; Laureys, Steven; Degueldre, Christian; Perrin, Fabien; Phillips, Christophe; Maquet, Pierre; Peigneux, Philippe

2005-10-15

We aimed at characterizing the neural correlates of delta activity during Non Rapid Eye Movement (NREM) sleep in non-sleep-deprived normal young adults, based on the statistical analysis of a positron emission tomography (PET) sleep data set. One hundred fifteen PET scans were obtained using H(2)(15)O under continuous polygraphic monitoring during stages 2-4 of NREM sleep. Correlations between regional cerebral blood flow (rCBF) and delta power (1.5-4 Hz) spectral density were analyzed using statistical parametric mapping (SPM2). Delta power values obtained at central scalp locations negatively correlated during NREM sleep with rCBF in the ventromedial prefrontal cortex, the basal forebrain, the striatum, the anterior insula, and the precuneus. These regions embrace the set of brain areas in which rCBF decreases during slow wave sleep (SWS) as compared to Rapid Eye Movement (REM) sleep and wakefulness (Maquet, P., Degueldre, C., Delfiore, G., Aerts, J., Peters, J.M., Luxen, A., Franck, G., 1997. Functional neuroanatomy of human slow wave sleep. J. Neurosci. 17, 2807-S2812), supporting the notion that delta activity is a valuable prominent feature of NREM sleep. A strong association was observed between rCBF in the ventromedial prefrontal regions and delta power, in agreement with electrophysiological studies. In contrast to the results of a previous PET study investigating the brain correlates of delta activity (Hofle, N., Paus, T., Reutens, D., Fiset, P., Gotman, J., Evans, A.C., Jones, B.E., 1997. Regional cerebral blood flow changes as a function of delta and spindle activity during slow wave sleep in humans. J. Neurosci. 17, 4800-4808), in which waking scans were mixed with NREM sleep scans, no correlation was found with thalamus activity. This latter result stresses the importance of an extra-thalamic delta rhythm among the synchronous NREM sleep oscillations. Consequently, this rCBF distribution might preferentially reflect a particular modulation of the

Effect of Thickness-to-Chord Ratio on Flow Structure of Low Swept Delta Wing

Science.gov (United States)

Gulsacan, Burak; Sencan, Gizem; Yavuz, Mehmet Metin

2017-11-01

The effect of thickness-to-chord (t/C) ratio on flow structure of a delta wing with sweep angle of 35 degree is characterized in a low speed wind tunnel using laser illuminated smoke visualization, particle image velocimetry, and surface pressure measurements. Four different t/C ratio varying from 4.75% to 19% are tested at angles of attack 4, 6, 8, and 10 degrees for Reynolds numbers Re =10,000 and 35,000. The results indicate that the effect of thickness-to-chord ratio on flow structure is quite substantial, such that, as the wing thickness increases, the flow structure transforms from leading edge vortex to three-dimensional separated flow regime. The wing with low t/C ratio of 4.75% experiences pronounced surface separation at significantly higher angle of attack compared to the wing with high t/C ratio. The results might explain some of the discrepancies reported in previously conducted studies related to delta wings. In addition, it is observed that the thickness of the shear layer separated from windward side of the wing is directly correlated with the thickness of the wing. To conclude, the flow structure on low swept delta wing is highly affected by t/C ratio, which in turn might indicate the potential usage of wing thickness as an effective flow control parameter.

Succession after fire: variation in \\delta13C of organic tissues and respired CO2 in boreal forests

Science.gov (United States)

Fessenden, J. E.; Li, H.; Mack, M.; Schuur, T.; Warren, S.; Randerson, J. T.

2001-12-01

Isotope ratios of carbon dioxide and leaf organic matter were measured in 5 neighboring forests of varying ages: 7, 14, 45, 140, and 160 years. These forests are composed primarily of black spruce (Picea Mariana) and quaking aspen (Populus tremuloides) with a shift in species dominance from aspen to spruce 50 years after fire disturbance. Research on the carbon isotope ratios of leaf material and CO2 was conducted to look for influences from species composition, forest age, and time after most recent burn. Samples of organic \\delta13C in whole leaf tissue were collected from the dominant species of each forest. Concurrent aboveground NPP measurements allowed us to estimate total ecosystem \\delta13C by providing a method for weighting \\delta13C of individual species and plant tissues. \\delta13CO2 and [CO2] were measured on canopy CO2 to determine the isotopic ratio of ecosystem respiration. The atmospheric results indicated that the \\delta13C of ecosystem respiration changes with successional stage. Specifically, the aspen dominating forests showed 13C depleted values relative to the spruce dominated forests. Organic results showed more 13C-enriched values with increased forest age and vegetation functional type. Specifically, oldest trees within the coniferous species had the most 13C-enriched values in leaf tissues. These results suggest that increases in the disturbance regime of northern boreal forests will lead to a decrease in the \\delta13C of ecosystem carbon with consequences for the atmospheric \\delta13C budget.

Development of sea level rise scenarios for climate change assessments of the Mekong Delta, Vietnam

Science.gov (United States)

Doyle, Thomas W.; Day, Richard H.; Michot, Thomas C.

2010-01-01

Rising sea level poses critical ecological and economical consequences for the low-lying megadeltas of the world where dependent populations and agriculture are at risk. The Mekong Delta of Vietnam is one of many deltas that are especially vulnerable because much of the land surface is below mean sea level and because there is a lack of coastal barrier protection. Food security related to rice and shrimp farming in the Mekong Delta is currently under threat from saltwater intrusion, relative sea level rise, and storm surge potential. Understanding the degree of potential change in sea level under climate change is needed to undertake regional assessments of potential impacts and to formulate adaptation strategies. This report provides constructed time series of potential sea level rise scenarios for the Mekong Delta region by incorporating (1) aspects of observed intra- and inter-annual sea level variability from tide records and (2) projected estimates for different rates of regional subsidence and accelerated eustacy through the year 2100 corresponding with the Intergovernmental Panel on Climate Change (IPCC) climate models and emission scenarios.

Carbon dynamics and CO2 and CH4 outgassing in the Mekong delta

Science.gov (United States)

Borges, Alberto V.; Abril, Gwenaël; Bouillon, Steven

2018-02-01

We report a data set of biogeochemical variables related to carbon cycling obtained in the three branches (Mỹ Tho, Hàm Luông, Cố Chiên) of the Mekong delta (Bến Tre province, Vietnam) in December 2003, April 2004, and October 2004. Both the inner estuary (upstream of the mouth) and the outer estuary (river plume) were sampled, as well as side channels. The values of the partial pressure of CO2 (pCO2) ranged between 232 and 4085 ppm, O2 saturation level (%O2) between 63 and 114 %, and CH4 between 2 and 2217 nmol L-1, within the ranges of values previously reported in temperate and tropical meso- and macro-tidal estuaries. Strong seasonal variations were observed. In the upper oligohaline estuary, low pCO2 (479-753 ppm) and high %O2 (98-106 %) values were observed in April 2004 most probably related to freshwater phytoplankton growth owing to low freshwater discharge (1400 m3 s-1) and increase in water residence time; during the two other sampling periods with a higher freshwater discharge (9300-17 900 m3 s-1), higher pCO2 (1895-2664 ppm) and lower %O2 (69-84 %) values were observed in the oligohaline part of the estuary. In October 2004, important phytoplankton growth occurred in the offshore part of the river plume as attested by changes in the contribution of particulate organic carbon (POC) to total suspended matter (TSM) (%POC) and the stable isotope composition of POC (δ13C-POC), possibly related to low TSM values (improvement of light conditions for phytoplankton development), leading to low pCO2 (232 ppm) and high %O2 (114 %) values. Water in the side channels in the Mekong delta was strongly impacted by inputs from the extensive shrimp farming ponds. The values of pCO2, CH4, %O2, and the stable isotope composition of dissolved inorganic carbon (δ13C-DIC) indicated intense organic matter degradation that was partly mediated by sulfate reduction in sediments, as revealed by the slope of total alkalinity (TA) and DIC covariations. The δ13C

C4 plant isotopic composition (delta13C) evidence for urban CO2 pollution in the city of Cotonou, Benin (West Africa).

Science.gov (United States)

Kèlomé, Nelly C; Lévêque, Jean; Andreux, Francis; Milloux, Marie-Jeanne; Oyédé, Lucien-Marc

2006-08-01

The carbon isotopic composition (delta13C) of plants can reveal the isotopic carbon content of the atmosphere in which they develop. The delta13C values of air and plants depend on the amount of atmospheric fossil fuel CO2, which is chiefly emitted in urban areas. A new indicator of CO2 pollution is tested using the delta13C variation in a C4 grass: Eleusine indica. A range of about 4 per thousand delta units was observed at different sites in Cotonou, the largest city in the Republic of Benin. The highest delta13C values, from -12 per thousand to -14 per thousand, were found in low traffic zones; low delta13C values, from -14 per thousand to -16 per thousand, were found in high traffic zones. The amount of fossil fuel carbon assimilated by plants represented about 20% of the total plant carbon content. An overall decrease in plant delta13C values was observed over a four-year monitoring period. This decrease was correlated with increasing vehicle traffic. The delta13C dataset and the corresponding geographical database were used to map and define zones of high and low 13C-depleted CO2 emissions in urban and sub-urban areas. The spatial distribution follows dominant wind directions, with the lowest emission zones found in the southwest of Cotonou. High CO2 emissions occurred in the north, the east and the center, providing evidence of intense anthropogenic activity related to industry and transportation.

Mystery of the delta(980)

International Nuclear Information System (INIS)

Cahn, R.N.; Landshoff, P.V.

1986-01-01

The apparent conflict between the dominance of the decay delta->etaπ in D->deltaπ and its absence in iota->deltaπ is analyzed. Explicit models are presented in which the nearby Kanti K threshold plays an important role in resolving the conflict. (orig.)

Design of the 12-bit Delta-Sigma Modulator using SC Technique for Vibration Sensor Output Processing

Directory of Open Access Journals (Sweden)

M. Pavlik

2012-04-01

Full Text Available The work deals with the design of the 12-bit Delta-Sigma modulator using switched capacitors (SC technique. The modulator serves to vibration sensor output processing. The first part describes the Delta-Sigma modulator parameters definition. Results of the proposed topology ideal model were presented as well. Next, the Delta-Sigma modulator circuitry on the transistor level was done. The ONSemiconductor I2T100 0.7 um CMOS technology was used for design. Then, the Delta-Sigma modulator nonidealities were simulated and implemented into the MATLAB ideal model of the modulator. The model of real Delta-Sigma modulator was derived. Consequently, modulator coefficients were optimized. Finally, the corner analysis of the Delta-Sigma modulator with the optimized coefficients was simulated. The value of SNDR = 82.2 dB (ENOB = 13.4 bits was achieved.

Niger Delta Development Commission and Sustainable ...

African Journals Online (AJOL)

Niger Delta Development Commission and Sustainable Development of Niger Delta Region of Nigeria: The Case of Rivers State. Goddey Wilson. Abstract. The study is on Niger Delta Development Commission and sustainable development of Niger Delta region of Nigeria, the case of Rivers State. The main objective of the ...

Degree distribution in discrete case

International Nuclear Information System (INIS)

Wang, Li-Na; Chen, Bin; Yan, Zai-Zai

2011-01-01

Vertex degree of many network models and real-life networks is limited to non-negative integer. By means of measure and integral, the relation of the degree distribution and the cumulative degree distribution in discrete case is analyzed. The degree distribution, obtained by the differential of its cumulative, is only suitable for continuous case or discrete case with constant degree change. When degree change is not a constant but proportional to degree itself, power-law degree distribution and its cumulative have the same exponent and the mean value is finite for power-law exponent greater than 1. -- Highlights: → Degree change is the crux for using the cumulative degree distribution method. → It suits for discrete case with constant degree change. → If degree change is proportional to degree, power-law degree distribution and its cumulative have the same exponent. → In addition, the mean value is finite for power-law exponent greater than 1.

Large old trees influence patterns of delta13C and delta15N in forests.

Science.gov (United States)

Weber, Pascale; Bol, Roland; Dixon, Liz; Bardgett, Richard D

2008-06-01

Large old trees are the dominant primary producers of native pine forest, but their influence on spatial patterns of soil properties and potential feedback to tree regeneration in their neighbourhood is poorly understood. We measured stable isotopes of carbon (delta(13)C) and nitrogen (delta(15)N) in soil and litter taken from three zones of influence (inner, middle and outer zone) around the trunk of freestanding old Scots pine (Pinus sylvestris L.) trees, to determine the trees' influence on below-ground properties. We also measured delta(15)N and delta(13)C in wood cores extracted from the old trees and from regenerating trees growing within their three zones of influence. We found a significant and positive gradient in soil delta(15)N from the inner zone, nearest to the tree centre, to the outer zone beyond the tree crown. This was probably caused by the higher input of (15)N-depleted litter below the tree crown. In contrast, the soil delta(13)C did not change along the gradient of tree influence. Distance-related trends, although weak, were visible in the wood delta(15)N and delta(13)C of regenerating trees. Moreover, the wood delta(15)N of small trees showed a weak negative relationship with soil N content in the relevant zone of influence. Our results indicate that large old trees control below-ground conditions in their immediate surroundings, and that stable isotopes might act as markers for the spatial and temporal extent of these below-ground effects. John Wiley & Sons, Ltd

An analytical framework for strategic delta planning : negotiating consent for long-term sustainable delta development

NARCIS (Netherlands)

Seijger, C.; Douven, W; Hermans, L.M.; Evers, J.; Phi, H. L.; Brunner, J.; Pols, L.; Ligtvoet, W.; Koole, S.; Slager, K.; Vermoolen, M.S.; Hasan, S.; Hoang, V. T M; van Halsema, G

2016-01-01

Sectoral planning on water, agriculture and urban development has not been able to prevent increased flood risks and environmental degradation in many deltas. Governments conceive strategic delta planning as a promising planning approach and develop strategic delta plans. Such plans are linked to

Growth and {delta}{sup 13}C responses to increasing atmospheric carbon dioxide concentrations for several crop species

Energy Technology Data Exchange (ETDEWEB)

Hanba, Y.T.; Wada, E. [Center for Ecological Research, Kyoto University, Kyoto (Japan); Osaki, M.; Nakamura, T. [Faculty of Agriculture, Hokkaido University, Hokkaido (Japan)

1996-04-01

The responses of plant growth and carbon isotope discrimination ({Delta}) to elevated atmospheric CO{sub 2} concentrations for several crop species (lettuce: Lactuca sativa L.; corn: Zea Mays L. var. P3540, wheat: Triticum aestivum L. var Haruyutaka; and soybean: Glycine Max (L). Merr. var. Kitamusume) were investigated. Shoot relative growth rate was used to indicate plant growth, and {delta}{sup 13}C value of leaf materials in corn (C4 species) was used to calculate {Delta} for C3 species. Plant growth was stimulated by enriched CO{sub 2}, while {Delta} remained almost constant as CO{sub 2} concentration changed. {Delta} showed interspecific difference, and the plant species of larger {Delta} had larger relative growth rates. Relative growth rates of the plants of larger {Delta} were stimulated by CO{sub 2} enrichment more than those of the plants of smaller {Delta}. We propose that plant {Delta} could be a possible parameter to assess the interspecific difference of plant response to the increasing atmospheric CO{sub 2} concentrations. 3 figs., 2 tabs., 25 refs.

The delta18O composition of Antarctic coastal current waters

International Nuclear Information System (INIS)

Frew, R.; Heywood, K.; Dennis, P.

1997-01-01

The varying proportions of 18 O to 16 O in sea water provide an oceanographic trace like salinity, but with an extra degree of freedom: salt is a tracer for the oceanic fluid, whereas the isotopic composition is a tracer specifically for the water component of that fluid. Hydrogen and oxygen isotopes are the variables most intimately related to the water component in the sea, therefore thay furnish a direct link to the water in the atmosphere and on continents and to the precipitation cycle which caused the salinity changes. The ratio of 18 O to 16 O (delta 18 O) ot waters is a powerful tracer in polar regions where sea and glacial ice processes decouple delta 18 O from salinity. Here we present observations from a significant but relatively unexplored component of the Southern Ocean current system, the Antarctic Coastal Current, and its associated Antarctic Slope Front. (author)

Catalyzing action towards the sustainability of deltas: deltas as integrated socio-ecological systems and sentinels of regional and global change

Science.gov (United States)

Foufoula-Georgiou, E.; Tessler, Z. D.; Brondizio, E.; Overeem, I.; Renaud, F.; Sebesvari, Z.; Nicholls, R. J.; Anthony, E.

2016-12-01

Deltas are highly dynamic and productive environments: they are food baskets of the world, home to biodiverse and rich ecosystems, and they play a central role in food and water security. However, they are becoming increasingly vulnerable to risks arising from human activities, land subsidence, regional water management, global sea-level rise, and climate extremes. Our Belmont Forum DELTAS project (BF-DELTAS: Catalyzing actions towards delta sustainability) encompasses an international network of interdisciplinary research collaborators with focal areas in the Mekong, Ganges Brahmaputra, and the Amazon deltas. The project is organized around five main modules: (1) developing an analytical framework for assessing delta vulnerability and scenarios of change (Delta-SRES), (2) developing an open-acess, science-based integrative modeling framework for risk assessment and decision support (Delta-RADS), (3) developing tools to support quantitative mapping of the bio-physical and socio-economic environments of deltas and consolidate bio-physical and social data within shared data repositories (Delta-DAT), (4) developing Global Delta Vulnerability Indices (Delta-GDVI) that capture current and projected scenarios for major deltas around the world , and (5) collaborating with regional stakeholders to put the science, modeling, and data into action (Delta-ACT). In this talk, a research summary will be presented on three research domains around which significant collaborative work was developed: advancing biophysical classification of deltas, understanding deltas as coupled socio-ecological systems, and analyzing and informing social and environmental vulnerabilities in delta regions.

Three New Offset {delta}{sup 11}B Isotope Reference Materials for Environmental Boron Isotope Studies

Energy Technology Data Exchange (ETDEWEB)

Rosner, M. [BAM Federal Institute for Materials Research and Testing, Berlin (Germany); IsoAnalysis UG, Berlin (Germany); Vogl, J. [BAM Federal Institute for Materials Research and Testing, Berlin (Germany)

2013-07-15

The isotopic composition of boron is a well established tool in various areas of science and industry. Boron isotope compositions are typically reported as {delta}{sup 11}B values which indicate the isotopic difference of a sample relative to the isotope reference material NIST SRM 951. A significant drawback of all of the available boron isotope reference materials is that none of them covers a natural boron isotope composition apart from NIST SRM 951. To fill this gap of required {delta}{sup 11}B reference materials three new solution boric acid reference materials were produced, which cover 60 per mille of the natural boron isotope variation (-20 to 40 per mille {delta}{sup 11}B) of about 100 per mille . The new reference materials are certified for their {delta}{sup 11}B values and are commercially available through European Reference Materials (http://www.erm-crm.org). The newly produced and certified boron isotope reference materials will allow straightforward method validation and quality control of boron isotope data. (author)

Computed estimates of maximum temperature elevations in fetal tissues during transabdominal pulsed Doppler examinations.

Science.gov (United States)

Bly, S H; Vlahovich, S; Mabee, P R; Hussey, R G

1992-01-01

Measured characteristics of ultrasonic fields were obtained in submissions from manufacturers of diagnostic ultrasound equipment for devices operating in pulsed Doppler mode. Simple formulae were used with these data to generate upper limits to fetal temperature elevations, delta Tlim, during a transabdominal pulsed Doppler examination. A total of 236 items were analyzed, each item being a console/transducer/operating-mode/intended-use combination, for which the spatial-peak temporal-average intensity, ISPTA, was greater than 500 mW cm-2. The largest calculated delta Tlim values were approximately 1.5, 7.1 and 8.7 degrees C for first-, second- and third-trimester examinations, respectively. The vast majority of items yielded delta Tlim values which were less than 1 degree C in the first trimester. For second- and third-trimester examinations, where heating of fetal bone determines delta Tlim, most delta Tlim values were less than 4 degrees C. The clinical significance of the results is discussed.

Erythromycin and azithromycin transport into Haemophilus influenzae ATCC 19418 under conditions of depressed proton motive force (delta mu H)

Energy Technology Data Exchange (ETDEWEB)

Capobianco, J.O.; Goldman, R.C. (Abbott Laboratories, IL (USA))

1990-09-01

The effect of collapsing the electrochemical proton gradient (delta mu H) on ({sup 3}H)erythromycin and ({sup 14}C)azithromycin transport in Haemophilus influenzae ATCC 19418 was studied. The proton gradient and membrane potential were determined from the distribution of (2-{sup 14}C)dimethadione and rubidium-86, respectively. delta mu H was reduced from 124 to 3 mV in EDTA-valinomycin-treated cells at 22{degrees}C with 150 mM KCl and 0.1 mM carbonyl cyanide m-chlorophenylhydrazone. During the collapse of delta mu H, macrolide uptake increased. Erythromycin efflux studies strongly suggested that this increase was not due to an energy-dependent efflux pump but was likely due to increased outer membrane permeability. These data indicated that macrolide entry was not a delta mu H-driven active transport process but rather a passive diffusion process.

Relationship between symmetry of porphyrinic pi-conjugated systems and singlet oxygen (1Delta g) yields: low-symmetry tetraazaporphyrin derivatives.

Science.gov (United States)

Ishii, Kazuyuki; Itoya, Hatsumi; Miwa, Hideya; Fujitsuka, Mamoru; Ito, Osamu; Kobayashi, Nagao

2005-07-07

We have investigated the excited-state properties and singlet oxygen ((1)Delta(g)) generation mechanism in phthalocyanines (4M; M = H(2), Mg, or Zn) and in low-symmetry metal-free, magnesium, and zinc tetraazaporphyrins (TAPs), that is, monobenzo-substituted (1M), adjacently dibenzo-substituted (2AdM), oppositely dibenzo-substituted (2OpM), and tribenzo-substituted (3M) TAP derivatives, whose pi conjugated systems were altered by fusing benzo rings. The S(1)(x) and S(1)(y) states (these lowest excited singlet states are degenerate in D(4)(h) symmetry) split in the low-symmetry TAP derivatives. The excited-state energies were quantitatively determined from the electronic absorption spectra. The lowest excited triplet (T(1)(x)) energies were also determined from phosphorescence spectra, while the second lowest excited triplet (T(1)(y)) states were evaluated by using the energy splitting between the T(1)(x) and T(1)(y) states previously reported (Miwa, H.; Ishii, K.; Kobayashi, N. Chem. Eur. J. 2004, 10, 4422-4435). The singlet oxygen quantum yields (Phi(Delta)) are strongly dependent on the pi conjugated system. In particular, while the Phi(Delta) value of 2AdH(2) is smallest in our system, that of 2OpH(2), an isomer of 2AdH(2), is larger than that of 4Zn, in contrast to the heavy atom effect. The relationship between the molecular structure and Phi(Delta) values can be transformed into a relationship between the S(1)(x) --> T(1)(y) intersystem crossing rate constant (k(ISC)) and the energy difference between the S(1)(x) and T(1)(y) states (DeltaE(S)(x)(T)(y)). In each of the Zn, Mg, and metal-free compounds, the Phi(Delta)/tau(F) values (tau(F): fluorescence lifetime), which are related to the k(ISC) values, are proportional to exp(-DeltaE(S)(x)(T)(y)), indicating that singlet oxygen ((1)Delta(g)) is produced via the T(1)(y) state and that the S(1)(x) --> T(1)(y) ISC process follows the energy-gap law. From the viewpoint of photodynamic therapy, our methodology

Pion-nucleon scattering in covariant baryon chiral perturbation theory with explicit Delta resonances

Energy Technology Data Exchange (ETDEWEB)

Yao, De-Liang [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); Siemens, D. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Bernard, V. [Groupe de Physique Théorique, Institut de Physique Nucléaire, UMR 8606,CNRS, University Paris-Sud, Université Paris-Saclay, 91405 Orsay Cedex (France); Epelbaum, E. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Gasparyan, A.M. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); SSC RF ITEP, Bolshaya Cheremushkinskaya 25, 117218 Moscow (Russian Federation); Gegelia, J. [Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany); Tbilisi State University, 0186 Tbilisi (Georgia); Krebs, H. [Institut für Theoretische Physik II, Ruhr-Universität Bochum, D-44780 Bochum (Germany); Meißner, Ulf-G. [Helmholtz Institut für Strahlen- und Kernphysik andBethe Center for Theoretical Physics, Universität Bonn, D-53115 Bonn (Germany); Institute for Advanced Simulation, Institut für Kernphysik and Jülich Center for Hadron Physics,Forschungszentrum Jülich, D-52425 Jülich (Germany)

2016-05-05

We present the results of a third order calculation of the pion-nucleon scattering amplitude in a chiral effective field theory with pions, nucleons and delta resonances as explicit degrees of freedom. We work in a manifestly Lorentz invariant formulation of baryon chiral perturbation theory using dimensional regularization and the extended on-mass-shell renormalization scheme. In the delta resonance sector, the on mass-shell renormalization is realized as a complex-mass scheme. By fitting the low-energy constants of the effective Lagrangian to the S- and P-partial waves a satisfactory description of the phase shifts from the analysis of the Roy-Steiner equations is obtained. We predict the phase shifts for the D and F waves and compare them with the results of the analysis of the George Washington University group. The threshold parameters are calculated both in the delta-less and delta-full cases. Based on the determined low-energy constants, we discuss the pion-nucleon sigma term. Additionally, in order to determine the strangeness content of the nucleon, we calculate the octet baryon masses in the presence of decuplet resonances up to next-to-next-to-leading order in SU(3) baryon chiral perturbation theory. The octet baryon sigma terms are predicted as a byproduct of this calculation.

Delta Morphodynamics Matters! Ecosystem Services, Poverty and Morphodynamic Change in the Ganges-Brahmaputra Mega-Delta

Science.gov (United States)

Nicholls, R. J.; Adger, N.; Allan, A.; Darby, S. E.; Hutton, C.; Matthews, Z.; Rahman, M.; Whitehead, P. G.; Wolf, J.

2013-12-01

The world's deltas are probably the most vulnerable type of coastal environment, and they face multiple stresses in the coming decades. These stresses include, amongst others, local drivers due to land subsidence, population growth and urbanisation within the deltas, regional drivers due to changes in catchment management (e.g. upstream land use and dam construction), as well as global climate change impacts such as sea-level rise. At the same time, the ecosystem services of river deltas support high population densities, with around 14% of the global population inhabiting deltas. A large proportion of these people experience extremes of poverty and they are therefore severely exposed to vulnerability from environmental and ecological stress and degradation. In areas close to or below the poverty boundary, both subsistence and cash elements of the economy tend to rely disproportionately heavily on ecosystem services which underpin livelihoods. Therefore, to sustainably manage delta environments they must be viewed as complex social-environmental systems where change is only partially driven by physical drivers such as sea level rise and climate change, and human-induced development activities are also critical. Here we outline a new conceptual framework for the development of methods to understand and characterise the key drivers of change in ecosystem services that affect the environment and economic status of populous deltas, focusing specifically on the Ganges-Brahmaputra-Meghna (GBM) mega-delta. The GBM delta is characterised by densely populated coastal lowlands with significant poverty, with livelihoods supported to a large extent by natural ecosystems such as the Sunderbahns (the largest mangrove forest in the world). However, the GBM delta is under severe development pressure due to many growing cities. At present the importance of ecosystems services to poverty and livelihoods is poorly understood. This is due to due to the complexity of interactions

Authenticity assessment of gamma- and delta-decalactone from prunus fruits by gas chromatography combustion/pyrolysis isotope ratio mass spectrometry (GC-C/P-IRMS).

Science.gov (United States)

Tamura, Hirotoshi; Appel, Markus; Richling, Elke; Schreier, Peter

2005-06-29

Authenticity assessment of gamma-decalactone (1) and delta-decalactone (2) from peach (Prunus persica var. persica), apricot (Prunus armeniaca), and nectarine (Prunus persica var. nectarina) was performed using gas chromatography-isotope ratio mass spectrometry (GC-IRMS) in the combustion (C) and pyrolysis (P) mode. In addition, commercially available synthetic (nature-identical) 1 and 2 as well as biotechnologically produced samples (declared to be "natural") were characterized by their delta(2)H(V)(-)(SMOW) and delta(13)C(V)(-)(PDB) values. For the Prunus fruits under study, rather narrow ranges of delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data of 1, varying from - 34.6 per thousand to - 38.4 per thousand and -160 per thousand to -206 per thousand, respectively, were obtained. Synthetic references of 1 showed delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data ranging from -27.4 per thousand to -28.3 per thousand and -151 per thousand to -184 per thousand, respectively. Samples of 1 declared to be "natural" exhibited ranges from -28.1 per thousand to -29.2 per thousand and -192 per thousand to -286 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively. For 2 from peach, apricot, and nectarine, delta(13)C(V)(-)(PDB) values ranging from -34.0 per thousand to -37.9 per thousand were determined; the delta(2)H(V)(-)(SMOW) values ranged from -171 per thousand to -228 per thousand. The delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data for synthetic 2 were -28.2 per thousand and -171 per thousand, respectively, that is, similar to those of 2 from "natural" origin, ranging from -27.7 per thousand to -30.1 per thousand and -185 per thousand to -230 per thousand for delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW), respectively. GC-C/P-IRMS allowed clear-cut analytical differentiation of the synthetic and "ex-plant" origin of 1 and 2, whereas narrow ranges of delta(13)C(V)(-)(PDB) and delta(2)H(V)(-)(SMOW) data were found for samples of

Thermodynamic and structure-property study of liquid-vapor equilibrium for aroma compounds.

Science.gov (United States)

Tromelin, Anne; Andriot, Isabelle; Kopjar, Mirela; Guichard, Elisabeth

2010-04-14

Thermodynamic parameters (T, DeltaH degrees , DeltaS degrees , K) were collected from the literature and/or calculated for five esters, four ketones, two aldehydes, and three alcohols, pure compounds and compounds in aqueous solution. Examination of correlations between these parameters and the range values of DeltaH degrees and DeltaS degrees puts forward the key roles of enthalpy for vaporization of pure compounds and of entropy in liquid-vapor equilibrium of compounds in aqueous solution. A structure-property relationship (SPR) study was performed using molecular descriptors on aroma compounds to better understand their vaporization behavior. In addition to the role of polarity for vapor-liquid equilibrium of compounds in aqueous solution, the structure-property study points out the role of chain length and branching, illustrated by the correlation between the connectivity index CHI-V-1 and the difference between T and log K for vaporization of pure compounds and compounds in aqueous solution. Moreover, examination of the esters' enthalpy values allowed a probable conformation adopted by ethyl octanoate in aqueous solution to be proposed.

Glucono-delta-lactone and citric acid as acidulants for lowering the heat resistance of Clostridium sporogenes PA 3679 in HTST working conditions.

Science.gov (United States)

Silla Santos, M H; Torres Zarzo, J

1995-04-01

The heat resistance of Clostridium sporogenes PA 3679 spores has been studied to establish the influence of acidification with glucono-delta-lactone (GDL) and citric acid on the thermal resistance parameters (DT and z) of this microorganism and to compare their effect with phosphate buffer and natural asparagus as reference substrates. A reduction in DT values was observed in asparagus purée as the acidification level increased with both acidulants although this effect was more evident at the lower treatment temperatures studied (121-127 degrees C). Citric acid was more effective for reducing the heat resistance of spores than GDL at all of the temperatures. The reduction in pH diminished the value of the z parameter, although it was necessary to lower the pH to 4.5 to obtain a significant reduction.

Inclusive production of. delta. /sup + +/(1232) in pn interactions at 19 GeV/c

Energy Technology Data Exchange (ETDEWEB)

Bakken, V.; Breivik, F.O.; Jacobsen, T.; Rudjord, A.L. (Oslo Univ. (Norway) Fysisk Inst.)

1982-12-21

We present a study of ..delta../sup + +/ production in pn interactions at 19 GeV/c, where the ..delta../sup + +/ is emitted in the protonlike (..delta..sub(F)/sup + +/) and neutron-like (..delta..sub(B)/sup + +/) c.m. hemispheres. The cross-section sigma(pn->..delta..sub(F)/sup + +/+X)=(3.09+-0.43) mb is about three times larger than sigma(pn->..delta..sub(B)/sup + +/+X)=(0.94+-0.34) mb. About 2/3 of ..delta..sub(F)/sup + +/ is peripherally produced with vertical stroketsub(p,..delta..)vertical stroke<1 (GeV/c)/sup 2/, while the cross-section for ..delta..sub(B)/sup + +/ production is nearly zero for vertical stroketsub(n,..delta..)vertical stroke<1 (GeV/c)/sup 2/. We have made a detailed study of the energy dependence of the reaction ap->..delta../sup + +/+X (a=p, anti p, n, ..pi..sup(+-), Ksup(+-)) for vertical stroketsub(p,..delta..)vertical stroke<1 (GeV/c)/sup 2/, by applying the same fitting procedure to extract the ..delta../sup + +/ cross-section to all available mass spectra. All the normalized cross-sections R=sigma(..delta../sup + +/)/sigmasub(inel) can be well described by R=R/sub 0/+R/sub 1/sup(a)psup(-..cap alpha..)sub(lab), where R/sub 0/ and ..cap alpha.. are the same for all reactions, while R/sub 1/sup(a) varies with the beam type a. The value of ..cap alpha.. is slightly below unity. The differential cross section of pn->..delta..sub(F)/sup + +/+X has been determined as a function of the variables t, t', x, y, psub(T)/sup 2/ and Msub(X)/sup 2/ both in the whole kinematical region and for vertical stroketsub(p,..delta..)vertical stroke<1 (GeV/c)/sup 2/. We show that the peripherally produced ..delta..sub(F)/sup + +/ is consistent with the dominance of the one-pion exchange mechanism. This follows from a study of the density matrix elements, the comparison of some properties of the system X with real ..pi../sup +/p data and from the results of a triple-Regge analysis.

Future Change to Tide-Influenced Deltas

Science.gov (United States)

Nienhuis, Jaap H.; Hoitink, A. J. F. (Ton); Törnqvist, Torbjörn E.

2018-04-01

Tides tend to widen deltaic channels and shape delta morphology. Here we present a predictive approach to assess a priori the effect of fluvial discharge and tides on deltaic channels. We show that downstream channel widening can be quantified by the ratio of the tide-driven discharge and the fluvial discharge, along with a second metric representing flow velocities. A test of our new theory on a selection of 72 deltas globally shows good correspondence to a wide range of environments, including wave-dominated deltas, river-dominated deltas, and alluvial estuaries. By quantitatively relating tides and fluvial discharge to delta morphology, we offer a first-order prediction of deltaic change that may be expected from altered delta hydrology. For example, we expect that reduced fluvial discharge in response to dam construction will lead to increased tidal intrusion followed by enhanced tide-driven sediment import into deltas, with implications for navigation and other human needs.

From Natural to Design River Deltas

Science.gov (United States)

Giosan, Liviu

2016-04-01

Productive and biologically diverse, deltaic lowlands attracted humans since prehistory and may have spurred the emergence of the first urban civilizations. Deltas continued to be an important nexus for economic development across the world and are currently home for over half a billion people. But recently, under the double whammy of sea level rise and inland sediment capture behind dams, they have become the most threatened coastal landscape. Here I will address several deceptively simple questions to sketch some unexpected answers using example deltas from across the world from the Arctic to the Tropics, from the Danube to the Indus, Mississippi to Godavari and Krishna, Mackenzie to Yukon. What is a river delta? What is natural and what is not in a river delta? Are the geological and human histories of a delta important for its current management? Is maintaining a delta the same to building a new one? Can we design better deltas than Nature? These answers help us see clearly that survival of deltas in the next century depends on human intervention and is neither assured nor simple to address or universally applicable. Empirical observations on the hydrology, geology, biology and biochemistry of deltas are significantly lagging behind modeling capabilities endangering the applicability of numerical-based reconstruction solutions and need to be ramped up significantly and rapidly across the world.

Phase transformation in delta Pu alloys at low temperature: in situ dilatometric study

Energy Technology Data Exchange (ETDEWEB)

Texier, G.; Oudot, B.; Platteau, C.; Ravat, B.; Delaunay, F. [CEA Valduc, 21 - Is-sur-Tille (France)

2010-07-01

The purpose of this work is to precisely study the martensitic transformation in a plutonium-gallium alloy. Thus, the thermodynamics and kinetics of the {delta} {yields} {alpha}' + {delta} transformation in a Pu-Ga alloy were studied under isochronal and isothermal conditions. The activation energy of the {delta} {yields} {alpha}' + {delta} phase transformation at a constant cooling rate (0.5 K. min{sup -1}) was determined by using Kissinger and Ozawa models. The average value of the activation energy was found to be at -56 kJ.mol{sup -1}. Dilatometry measurement was also used to trace 'in situ' the entire transformation for several temperatures. The kinetics of the {delta} {yields} {alpha}' + {delta} transformation were modelled under isothermal conditions in the theoretical frame of the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory. It is proposed that the transformation consists of three stages. The {alpha}' transformation begins with a nucleation of pre-existing embryos. Then, both nucleation and rapid growth of {alpha}' occurs simultaneously and finally, the plates width expend. Apparent activation energies for nucleation and growth transformation were determined from the temperature dependence of the constant K at respectively -34 kJ.mol{sup -1} and -60 kJ.mol{sup -1}. Dler et al. [1] investigated also the thermodynamics and the kinetics of the martensitic transformation in Pu alloys. These nucleation energies were found by modelling of heterogeneous martensitic nucleation via strain interaction with observed superdislocation-like nucleation sites in PuGa alloys. The values obtain by this model was very close to those we find. Investigations in steels alloys indicate that these energies are of the same order for nucleation near dislocation. Then, it could be indicating a strong relationship between these dislocations and martensitic nucleation sites. (authors)

Phase transformation in {delta} Pu alloys at low temperature: In situ dilatometric study

Energy Technology Data Exchange (ETDEWEB)

Texier, G; Oudot, B; Platteau, C; Ravat, B; Delaunay, F, E-mail: gwenael.texier@cea.fr, E-mail: benoit.oudot@cea.fr [CEA, DAM, Valduc, Is sur Tille 21120 (France)

2010-03-15

The purpose of this work is to precisely study the martensitic transformation in a plutonium-gallium alloy. Thus, the thermodynamics and kinetics of the {delta}{yields}{alpha}'+{delta} phase transformation in a Pu-Ga alloy were studied under isochronal and isothermal conditions. The activation energy of the {delta}{yields}{alpha}'+{delta} phase transformation at a constant cooling rate (0.5 K.min{sup -1}) was determined by using Kissinger and Ozawa models. The average value of the activation energy was found to be at -56 kJ.mol{sup -1}. Dilatometry measurement was also used to trace 'in situ' the entire transformation for several temperatures. The kinetics of the {delta}{yields}{alpha}'+{delta} transformation were modelled under isothermal conditions in the theoretical frame of the Johnson-Mehl-Avrami-Kolmogorov (JMAK) theory. It is proposed that the transformation consists of three stages. The {alpha}' transformation begins with a nucleation of pre-existing embryos. Then, both nucleation and rapid growth of {alpha}' occurs simultaneously and finally, the plates width expend. Apparent activation energies for nucleation and growth transformation were determined from the temperature dependence of the constant K at respectively -34 kJ.mol{sup -1} and -60 kJ.mol{sup -1}. Adler et al. [1] investigated also the thermodynamics and the kinetics of the martensitic transformation in Pu alloys. These nucleation energies were found by modelling of heterogeneous martensitic nucleation via strain interaction with observed superdislocation-like nucleation sites in PuGa alloys. The values obtain by this model was very close to those we find. Investigations in steels alloys indicate that these energies are of the same order for nucleation near dislocation. Then, it could be indicating a strong relationship between these dislocations and martensitic nucleation sites.

On the experimental value of the DELTA sup + (1232) mass from gamma p -> n pi sup + (p suppi sup 0) reactions

CERN Document Server

Omelaenko, A S

2002-01-01

The reliability of the phenomenological estimates for the DELTA sup + (1232) mass is questioned coming from the of pi sup + and pi sup 0 mesons photoproduction data off proton target till the end of 2001. The origin of an old discrepancy for the DELTA sup + (1232) mass presented in tables of the Particle Data Group is discussed.

Biomass co-firing for Delta Electricity

International Nuclear Information System (INIS)

Anon

2014-01-01

Electricity generator Delta Electricity has implemented a biomass co-firing program at its Vales Point power station on the Central Coast to reduce its reliance on coal and emissions of CO 2 . The program comprises two parts: direct co-firing with coal of up to 5% biomass; and development of Continuous Biomass Converter (CBC) technology with the Crucible Group to remove technology constraints and enable much higher rates of biomass co-firing. It is talking industrial scale tests. Delta increased biomass co-firing in 2013/14 to 32,000 tonnes, up from just 3,000 tonnes the previous year, and conducted biochar co-firing trials at a rate equivalent to 400,000 tonnes per annum to demonstrate the potential of CBC technology. It reduced CO 2 emissions in 2013/14 by more than 32,000 tonnes. 'Legislation and regulations define biomass as renewable,' said Delta Electricity sustainability manager Justin Flood. 'By preferring biomass over coal, the carbon in the coal is not burnt and remains locked up.' One biomass source is wood waste that would normally go to landfill, but the primary driver of Delta's recent increase in co-firing is sawmill residues. 'Previously there was a higher value market for the residues for paper pulp. However, when that market evaporated the timber industry was left with a sizable problem in terms of what to do with its residues and the loss of revenue,' said Flood. The way greenhouse gas accounting is conducted in Australia, with carbon emissions based on site activities, makes it difficult to undertake a life cycle assessment of the program. 'However, some of the international studies looking at this issue have concluded that the net carbon emissions of the biomass system are significantly lower than the coal system because of the uptake of carbon during biomass growth,' said Flood. Delta identified two challenges, sourcing the feedstock and that biomass conversion to electricity is slightly less

Delta isobars in neutron stars

Directory of Open Access Journals (Sweden)

Pagliara Giuseppe

2015-01-01

Full Text Available The appearance of delta isobars in beta-stable matter is regulated by the behavior of the symmetry energy at densities larger than saturation density. We show that by taking into account recent constraints on the density derivative of the symmetry energy and the theoretical and experimental results on the excitations of delta isobars in nuclei, delta isobars are necessary ingredients for the equations of state used for studying neutron stars. We analyze the effect of the appearance of deltas on the structure of neutron stars: as in the case of hyperons, matter containing delta is too soft for allowing the existence of 2M⊙ neutron stars. Quark stars on the other hand, could reach very massive configurations and they could form from a process of conversion of hadronic stars in which an initial seed of strangeness appears through hyperons.

Reactivity, structure and physical properties of SrCo{sub 2.5+{delta}} and La{sub 2}CoO{sub 4.0+{delta}}. In situ X-ray diffraction and neutrons study; Reactivite, structure et proprietes physiques de SrCoO{sub 2.5+{delta}} et La{sub 2}CoO{sub 4.0+{delta}}. Etude par diffraction des rayons X et des neutrons in situ

Energy Technology Data Exchange (ETDEWEB)

Le Toquin, R.

2003-11-15

This work was devoted to the study of the reactivity and more specifically the influence of the intercalated oxygen amount {delta} on the structure and physical properties of SrCoO{sub 2.5+{delta}} et La{sub 2}CoO{sub 4.0+{delta}} We controlled the oxidation level by means of reversible electrochemical red ox reaction at room temperature. Structural modifications, especially disorder, and electronic properties were studied for the first time on large orientated single crystal. In the SrCoO{sub 2.5+{delta}} system, after structural and electronic characterisation of the end phases, we studied the real structure of the brownmillerite SrCoO{sub 2.5} phase using single crystal. Moreover, we investigated structural and magnetic evolution upon red ox cycle using X-ray diffraction on 6 times twinned single crystal and in situ neutron powder diffraction. Two intermediate SrCoO{sub 2.75} and SrCoO{sub 2.82} phases have been observed. The reaction on single crystal has evidenced the evolution of domain structure. For the La{sub 2}CoO{sub 4+{delta}} system, we synthesised a large variety of single crystal with stoichiometry {delta} 0.0, 0.09, 0.12, 0.16, 0.20 and 0.25. Using single crystal X-ray and neutron diffraction, we showed a disorder-order transition of the apical and interstitial oxygen for the higher {delta} values. (author)

Holocene Flexural Deformation over the Nile Delta: Evidence from Radar Interferometry

Science.gov (United States)

Gebremichael, E.; Sultan, M.; Becker, R.

2017-12-01

Isostatic adjustment and subsequent subsidence and uplift due to sediment and water loading and unloading mechanisms is one of the major factors that produce regional deformational patterns across river deltas. Using 84 Envisat ASAR scenes that were acquired (2004 - 2010) along three tracks and applying Persistent scatterer (PS) radar interferometric techniques, we documented flexural deformational patterns over the entire Nile Delta (length: 186 km; width: 240 km) of Egypt. The passive continental margin of Africa subsided from Jurassic time onwards due to isostatic loading creating an accommodation space and consequently, the deposition of relatively younger sediments on the oceanic crust. In river deltas, the flexural isostasy model dictates that a subsidence in the oceanic crust side should be balanced by a bulge (uplift) in the flanking regions. Using radar interferometry, we were able to identify the flexural deformation pattern and map its spatial extent over the northern and central Nile Delta region. Findings include: (1) the northern Nile Delta region (block) is separated from the southern delta region by an east-west trending, extensively faulted, hinge line that signifies the boundary between two deformational patterns (subsidence and uplift). It separates the highly subsiding (up to 9.8 mm/yr) northern delta block (up to 85 km long) from the nearly stable (0.4 mm/yr; averaged) southern delta block (up to 91 km long). The hinge line marks the end of the passive continental margin of Africa and the beginning of the oceanic crust of the Mediterranean. (2) We mapped the extent of a 20-40 km wide flexural uplift zone to the south of the hinge line. Within the flexural uplift zone (2.5 mm/yr; averaged), there is a gradual increase in uplift rate reaching peak value (up to 7 mm/yr) near the midpoint of the zone. (3) The uplift rate gradually decreases south of the flexure boundary reaching 0.3 mm/yr at the southern periphery of the delta. (4) The flexural

Seasonal mercury concentrations and {delta}{sup 15}N and {delta}{sup 13}C values of benthic macroinvertebrates and sediments from a historically polluted estuary in south central Chile

Energy Technology Data Exchange (ETDEWEB)

Diaz-Jaramillo, Mauricio, E-mail: mdiazjaramillo@conicet.gov.ar [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile); Munoz, Claudia; Rudolph, Ignacio [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile); Servos, Mark [Department of Biology, University of Waterloo, ON (Canada); Barra, Ricardo [Aquatic Systems Research Unit, EULA Chile Environmental Sciences Centre, Universidad de Concepcion (Chile)

2013-01-01

The Lenga Estuary is one of the most industrialized sites in south central Chile where the historic operation of chlor-alkali plants resulted in large quantities of mercury (Hg) being deposited into the estuary. This historical contamination may still represent a risk to the biota in the estuary. To investigate this four macroinvertebrates, Neotrypaea uncinata (ghostshrimp), Elminius kingii (barnacle), Hemigrapsus crenulatus (shore crab) and Perinereis gualpensis (ragworm) were collected seasonally from three different sites in the Lenga Estuary and one in a reference estuary (Tubul Estuary), and analyzed for Hg and stable isotopes ({delta}{sup 15}N and {delta}{sup 13}C). Mercury concentrations in Lenga sediments ranged from 0.4 {+-} 0.1 to 13 {+-} 3 mg/kg, while those in Tubul sediments ranged from 0.02 {+-} 0.01 to 0.07 {+-} 0.09 mg/kg. Total Hg concentrations of invertebrates were significantly different between estuaries (p < 0.05), but not by species or season for each estuary (p > 0.05). In contrast, organic Hg concentrations were different by species and season with shore crab muscle tissues exhibiting the greatest percent difference. Site-specific relationships demonstrated that total Hg concentrations in ragworm best reflected the total Hg sediment mercury concentrations. Signatures of {delta}{sup 13}C were correlated to the organic Hg % rather than total Hg. This suggests that organic Hg concentrations in these species were related to the carbon sources. -- Highlights: Black-Right-Pointing-Pointer Hg in sediments and biota from Lenga Estuary were elevated compared to nearby estuary. Black-Right-Pointing-Pointer Invertebrates showed interspecific and seasonal differences in terms of organic Hg %. Black-Right-Pointing-Pointer Total Hg levels in the ragworm best reflect Hg sediment gradient in Lenga Estuary. Black-Right-Pointing-Pointer Interspecific variation in {delta}{sup 13}C signatures indicated different feeding modes. Black

Entropy and optimality in river deltas

Science.gov (United States)

Tejedor, Alejandro; Longjas, Anthony; Edmonds, Douglas A.; Zaliapin, Ilya; Georgiou, Tryphon T.; Rinaldo, Andrea; Foufoula-Georgiou, Efi

2017-10-01

The form and function of river deltas is intricately linked to the evolving structure of their channel networks, which controls how effectively deltas are nourished with sediments and nutrients. Understanding the coevolution of deltaic channels and their flux organization is crucial for guiding maintenance strategies of these highly stressed systems from a range of anthropogenic activities. To date, however, a unified theory explaining how deltas self-organize to distribute water and sediment up to the shoreline remains elusive. Here, we provide evidence for an optimality principle underlying the self-organized partition of fluxes in delta channel networks. By introducing a suitable nonlocal entropy rate (nER) and by analyzing field and simulated deltas, we suggest that delta networks achieve configurations that maximize the diversity of water and sediment flux delivery to the shoreline. We thus suggest that prograding deltas attain dynamically accessible optima of flux distributions on their channel network topologies, thus effectively decoupling evolutionary time scales of geomorphology and hydrology. When interpreted in terms of delta resilience, high nER configurations reflect an increased ability to withstand perturbations. However, the distributive mechanism responsible for both diversifying flux delivery to the shoreline and dampening possible perturbations might lead to catastrophic events when those perturbations exceed certain intensity thresholds.

The evolution of a subaqueous delta in the Anthropocene: A stratigraphic investigation of the Brazos River delta, TX USA

Science.gov (United States)

Carlin, Joseph A.; Dellapenna, Timothy M.

2015-12-01

Globally, deltas are increasingly threatened by anthropogenic activities. As a result, deltas now evolve through the combined effects of natural and human-induced processes occurring throughout the fluvial-deltaic system. The Brazos River delta, located along the Texas coast in the northwestern Gulf of Mexico, and its watershed have been impacted by direct and indirect human activities since the late 19th century. This provides an opportunity to investigate how such alterations have shaped the evolution of a delta in the Anthropocene, a time when humans are drivers of geological change. Historic alteration to the delta and watershed include extensive agricultural activity, jetty construction at the mouth in the late 1890s, mouth diversion ~10 km to the southwest in 1929, and reservoir construction throughout the early and mid 20th Century. Three subaerial deltaic geometries provided the framework to connect subaerial deltaic responses, to the anthropogenic alterations, to the resulting stratigraphic characteristics observed in the subaqueous delta. This study utilized high-resolution geophysical data (swath bathymetry, side scan sonar, CHIRP subbottom profiling) on the subaqueous delta to investigate the subaqueous delta stratigraphy and infer the processes that shaped the deltaic record over time. The results showed distinct areas across the subaqueous delta that were dominated by erosion and deposition. Erosional areas corresponded to earlier growth phase depocenters being exposed at the surface, while the depositional areas corresponded to areas with the most recent growth phase depocenter overlying the earlier depocenters. These results highlight that the subaqueous depocenter has migrated westward over time, consistent with the observed changes to the subaerial delta. Additionally, the data showed that evidence for these past growth phases and depocenters may be preserved within the subaqueous delta, even after subaerial portions of the delta returned to pre

Challenges Facing the Sacramento–San Joaquin Delta: Complex, Chaotic, or Simply Cantankerous?

Directory of Open Access Journals (Sweden)

Samuel N. Luoma

2015-09-01

Full Text Available doi: http://dx.doi.org/10.15447/sfews.2015v13iss3art7Freshwater is a scarce and precious resource in California; its overall value is being made clear by the current severe drought. The Sacramento–San Joaquin Delta is a critical node in a complex water supply system that extends throughout much of the western U.S. wherein demand is exceeding supply. The Delta also underpins a major component of the U.S. economy, helps feed a substantial part of the country, is a unique and valuable ecological resource, and is a place with a rich cultural heritage. Sustaining the Delta is a problem that manifests itself in many dimensions including the physical structure of the Delta, the conflicting demands for water, changing water quality, rapidly evolving ecological character, and high institutional complexity. The problems of the California Delta are increasingly complex, sometimes chaotic, and always contentious. There is general agreement that current management will sustain neither the Delta ecosystem nor high-quality water exports, as required under the Delta Reform Act, so there is a renewed urgency to address all dimensions of the problem aggressively. Sustainable management of the Delta ecosystem and California’s highly variable water supply, in the face of global climate change, will require bold political decisions that include adjustments to the infrastructure but give equal emphasis to chronic overuse and misuse of water, promote enhanced efficiency of water use, and facilitate new initiatives for ecosystem recovery. This new approach will need to be underpinned by collaborative science that supports ongoing evaluation and re-adjustment of actions. Problems like the Delta are formally “wicked" problems that cannot be “solved” in the traditional sense, but they can be managed with appropriate knowledge and flexible institutions. Where possible, it is advisable to approach major actions incrementally, with an eye toward avoiding

deltaPlotR: An R Package for Di?erential Item Functioning Analysis with Ango? s Delta Plot

OpenAIRE

David Magis; Bruno Facon

2014-01-01

Angoff's delta plot is a straightforward and not computationally intensive method to identify differential item functioning (DIF) among dichotomously scored items. This approach was recently improved by proposing an optimal threshold selection and by considering several item purification processes. Moreover, to support practical DIF analyses with the delta plot and these improvements, the R package deltaPlotR was also developed. The purpose of this paper is twofold: to outline the delta plot ...

Delta hedging strategies comparison

DEFF Research Database (Denmark)

De Giovanni, Domenico; Ortobelli, S.; Rachev, S.T.

2008-01-01

In this paper we implement dynamic delta hedging strategies based on several option pricing models. We analyze different subordinated option pricing models and we examine delta hedging costs using ex-post daily prices of S&P 500. Furthermore, we compare the performance of each subordinated model...

The Enabling Delta Life Initiative - Global Programme of Action on Deltas - Programme description

NARCIS (Netherlands)

Driel, van W.F.; Skyllerstedt, S.; Wosten, J.H.M.

2014-01-01

Being ‘hotspots’ of human activity with generally high population densities, deltas are vulnerable to changes induced by a range of driving forces, both natural and anthropogenic. In addition to already existing challenges, uncertainty of the possible impacts of climate change, low lying deltas

C{sub 4} plant isotopic composition ({delta}{sup 13}C) evidence for urban CO{sub 2} pollution in the city of Cotonou, Benin (West Africa)

Energy Technology Data Exchange (ETDEWEB)

Kelome, Nelly C.; Leveque, Jean; Andreux, Francis; Milloux, Marie-Jeanne [UMR Microbiologie et Geochimie des Sols INRA, Universite de Bourgogne, Centre des Sciences de la Terre, 6 Bd Gabriel, 21000 Dijon (France); Oyede, Lucien-Marc [Departement des Sciences de la Terre, Universite d' Abomey-Calavi, 01 B.P. 526, Cotonou (Benin)

2006-08-01

The carbon isotopic composition ({delta}{sup 13}C) of plants can reveal the isotopic carbon content of the atmosphere in which they develop. The {delta}{sup 13}C values of air and plants depend on the amount of atmospheric fossil fuel CO{sub 2}, which is chiefly emitted in urban areas. A new indicator of CO{sub 2} pollution is tested using the {delta}{sup 13}C variation in a C{sub 4} grass: Eleusine indica. A range of about 4%% delta units was observed at different sites in Cotonou, the largest city in the Republic of Benin. The highest {delta}{sup 13}C values, from -12%% to -14%%, were found in low traffic zones; low {delta}{sup 13}C values, from -14%% to -16%%, were found in high traffic zones. The amount of fossil fuel carbon assimilated by plants represented about 20% of the total plant carbon content. An overall decrease in plant {delta}{sup 13}C values was observed over a four-year monitoring period. This decrease was correlated with increasing vehicle traffic. The {delta}{sup 13}C dataset and the corresponding geographical database were used to map and define zones of high and low {sup 13}C-depleted CO{sub 2} emissions in urban and sub-urban areas. The spatial distribution follows dominant wind directions, with the lowest emission zones found in the southwest of Cotonou. High CO{sub 2} emissions occurred in the north, the east and the center, providing evidence of intense anthropogenic activity related to industry and transportation. (author)

C{sub 4} plant isotopic composition ((delta){sup 13}C) evidence for urban CO{sub 2} pollution in the city of Cotonou, Benin (West Africa)

Energy Technology Data Exchange (ETDEWEB)

Kelome, Nelly C.; Leveque, Jean; Andreux, Francis; Milloux, Marie-Jeanne [UMR Microbiologie et Geochimie des Sols INRA, Universite de Bourgogne, Centre des Sciences de la Terre, 6 Bd Gabriel, 21000 Dijon (France); Oyede, Lucien-Marc [Departement des Sciences de la Terre, Universite d' Abomey-Calavi, 01 B.P. 526, Cotonou (Benin)

2006-08-01

The carbon isotopic composition ((delta){sup 13}C) of plants can reveal the isotopic carbon content of the atmosphere in which they develop. The (delta){sup 13}C values of air and plants depend on the amount of atmospheric fossil fuel CO{sub 2}, which is chiefly emitted in urban areas. A new indicator of CO{sub 2} pollution is tested using the (delta){sup 13}C variation in a C{sub 4} grass: Eleusine indica. A range of about 4%% delta units was observed at different sites in Cotonou, the largest city in the Republic of Benin. The highest (delta){sup 13}C values, from -12%% to -14%%, were found in low traffic zones; low (delta){sup 13}C values, from -14%% to -16%%, were found in high traffic zones. The amount of fossil fuel carbon assimilated by plants represented about 20% of the total plant carbon content. An overall decrease in plant (delta){sup 13}C values was observed over a four-year monitoring period. This decrease was correlated with increasing vehicle traffic. The (delta){sup 13}C dataset and the corresponding geographical database were used to map and define zones of high and low {sup 13}C-depleted CO{sub 2} emissions in urban and sub-urban areas. The spatial distribution follows dominant wind directions, with the lowest emission zones found in the southwest of Cotonou. High CO{sub 2} emissions occurred in the north, the east and the center, providing evidence of intense anthropogenic activity related to industry and transportation. (author)

Lava delta deformation as a proxy for submarine slope instability

Science.gov (United States)

Di Traglia, Federico; Nolesini, Teresa; Solari, Lorenzo; Ciampalini, Andrea; Frodella, William; Steri, Damiano; Allotta, Benedetto; Rindi, Andrea; Marini, Lorenzo; Monni, Niccolò; Galardi, Emanuele; Casagli, Nicola

2018-04-01

The instability of lava deltas is a recurrent phenomenon affecting volcanic islands, which can potentially cause secondary events such as littoral explosions (due to interactions between hot lava and seawater) and tsunamis. It has been shown that Interferometric Synthetic Aperture Radar (InSAR) is a powerful technique to forecast the collapse of newly emplaced lava deltas. This work goes further, demonstrating that the monitoring of lava deltas is a successful strategy by which to observe the long-term deformation of subaerial-submarine landslide systems on unstable volcanic flanks. In this paper, displacement measurements derived from Synthetic Aperture Radar (SAR) imagery were used to detect lava delta instability at Stromboli volcano (Italy). Recent flank eruptions (2002-2003, 2007 and 2014) affected the Sciara del Fuoco (SdF) depression, created a "stacked" lava delta, which overlies a pre-existing scar produced by a submarine-subaerial tsunamigenic landslide that occurred on 30 December 2002. Space-borne X-band COSMO-SkyMED (CSK) and C-band SENTINEL-1A (SNT) SAR data collected between February 2010 and October 2016 were processed using the SqueeSAR algorithm. The obtained ground displacement maps revealed the differential ground motion of the lava delta in both CSK and SNT datasets, identifying a stable area (characterized by less than 2 mm/y in both datasets) within the northern sector of the SdF and an unstable area (characterized by velocity fields on the order of 30 mm/y and 160 mm/y in the CSK and SNT datasets, respectively) in the central sector of the SdF. The slope stability of the offshore part of the SdF, as reconstructed based on a recently performed multibeam bathymetric survey, was evaluated using a 3D Limit Equilibrium Method (LEM). In all the simulations, Factor of Safety (F) values between 0.9 and 1.1 always characterized the submarine slope between the coastline and -250 m a.s.l. The critical surfaces for all the search volumes corresponded to

Mapping Soil Carbon in the Yukon Kuskokwim River Delta Alaska

Science.gov (United States)

Natali, S.; Fiske, G.; Schade, J. D.; Mann, P. J.; Holmes, R. M.; Ludwig, S.; Melton, S.; Sae-lim, N.; Jardine, L. E.; Navarro-Perez, E.

2017-12-01

Arctic river deltas are hotspots for carbon storage, occupying 10% of carbon stored in arctic permafrost. The Yukon Kuskokwim (YK) Delta, Alaska is located in the lower latitudinal range of the northern permafrost region in an area of relatively warm permafrost that is particularly vulnerable to warming climate. Active layer depths range from 50 cm on peat plateaus to >100 cm in wetland and aquatic ecosystems. The size of the soil organic carbon pool and vulnerability of the carbon in the YK Delta is a major unknown and is critically important as climate warming and increasing fire frequency may make this carbon vulnerable to transport to aquatic and marine systems and the atmosphere. To characterize the size and distribution of soil carbon pools in the YK Delta, we mapped the land cover of a 1910 km2 watershed located in a region of the YK Delta that was impacted by fire in 2015. The map product was the result of an unsupervised classification using the Weka K Means clustering algorithm implemented in Google's Earth Engine. Inputs to the classification were Worldview2 resolution optical imagery (1m), Arctic DEM (5m), and Sentinel 2 level 1C multispectral imagery, including NDVI, (10 m). We collected 100 soil cores (0-30 cm) from sites of different land cover and landscape position, including moist and dry peat plateaus, high and low intensity burned plateaus, fens, and drained lakes; 13 lake sediment cores (0-50 cm); and 20 surface permafrost cores (to 100 cm) from burned and unburned peat plateaus. Active layer and permafrost soils were analyzed for organic matter content, soil moisture content, and carbon and nitrogen pools (30 and 100 cm). Soil carbon content varied across the landscape; average carbon content values for lake sediments were 12% (5- 17% range), fens 26% (9-44%), unburned peat plateaus 41% (34-44%), burned peat plateaus 19% (7-34%). These values will be used to estimate soil carbon pools, which will be applied to the spatial extent of each

Every plane graph of maximum degree 8 has an edge-face 9-colouring.

NARCIS (Netherlands)

R.J. Kang (Ross); J.-S. Sereni; M. Stehlík

2011-01-01

textabstractAn edge-face coloring of a plane graph with edge set $E$ and face set $F$ is a coloring of the elements of $E\\cup F$ such that adjacent or incident elements receive different colors. Borodin proved that every plane graph of maximum degree $\\Delta \\ge 10$ can be edge-face colored with

The Future of the Mississippi Delta: Shifting Baselines, Diminishing Resilience, and Growing Non-Sustainability

Science.gov (United States)

Day, J.

2017-12-01

Ecosystems and human communities of the Mississippi delta developed with predictable basin inputs, stable sea level, and as an open system with a high degree of interaction among drainage basin inputs, deltaic plain, and the coastal sea. Human activity changed altered the coast and lowered predictability. Management has become very energy intensive and dependent on cheap resources with more hard engineering and less ecological engineering. Pervasive alteration of the basin and delta and global change have altered the baseline and change is accelerating. Climate change projections include not only sea-level rise, but also more stronger hurricanes, increased large river floods, and more intense rainfall events and droughts. A sustainable Mississippi is outside of the boundaries of the current CMP.

Stable isotope deltas: Tiny, yet robust signatures in nature

Science.gov (United States)

Brand, Willi A.; Coplen, Tyler B.

2012-01-01

Although most of them are relatively small, stable isotope deltas of naturally occurring substances are robust and enable workers in anthropology, atmospheric sciences, biology, chemistry, environmental sciences, food and drug authentication, forensic science, geochemistry, geology, oceanography, and paleoclimatology to study a variety of topics. Two fundamental processes explain the stable isotope deltas measured in most terrestrial systems: isotopic fractionation and isotope mixing. Isotopic fractionation is the result of equilibrium or kinetic physicochemical processes that fractionate isotopes because of small differences in physical or chemical properties of molecular species having different isotopes. It is shown that the mixing of radioactive and stable isotope end members can be modelled to provide information on many natural processes, including 14C abundances in the modern atmosphere and the stable hydrogen and oxygen isotopic compositions of the oceans during glacial and interglacial times. The calculation of mixing fractions using isotope balance equations with isotope deltas can be substantially in error when substances with high concentrations of heavy isotopes (e.g. 13C, 2H, and 18O ) are mixed. In such cases, calculations using mole fractions are preferred as they produce accurate mixing fractions. Isotope deltas are dimensionless quantities. In the International System of Units (SI), these quantities have the unit 1 and the usual list of prefixes is not applicable. To overcome traditional limitations with expressing orders of magnitude differences in isotope deltas, we propose the term urey (symbol Ur), after Harold C. Urey, for the unit 1. In such a manner, an isotope delta value expressed traditionally as−25 per mil can be written as−25 mUr (or−2.5 cUr or−0.25 dUr; the use of any SI prefix is possible). Likewise, very small isotopic differences often expressed in per meg ‘units’ are easily included (e.g. either+0.015 ‰ or+15 per meg

Tidal controls on river delta morphology

Science.gov (United States)

Hoitink, A. J. F.; Wang, Z. B.; Vermeulen, B.; Huismans, Y.; Kästner, K.

2017-09-01

River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world’s largest deltas intensifies. Harbour development, construction of flood defences, sand mining and land reclamation emerge as key contemporary factors that exert an impact on delta morphology. Tides interacting with river discharge can play a crucial role in the morphodynamic development of deltas under pressure. Emerging insights into tidal controls on river delta morphology suggest that--despite the active morphodynamics in tidal channels and mouth bar regions--tidal motion acts to stabilize delta morphology at the landscape scale under the condition that sediment import during low flows largely balances sediment export during high flows. Distributary channels subject to tides show lower migration rates and are less easily flooded by the river because of opposing non-linear interactions between river discharge and the tide. These interactions lead to flow changes within channels, and a more uniform distribution of discharge across channels. Sediment depletion and rigorous human interventions in deltas, including storm surge defence works, disrupt the dynamic morphological equilibrium and can lead to erosion and severe scour at the channel bed, even decades after an intervention.

Delta Semantics Defined By Petri Nets

DEFF Research Database (Denmark)

Jensen, Kurt; Kyng, Morten; Madsen, Ole Lehrmann

and the possibility of using predicates to specify state changes. In this paper a formal semantics for Delta is defined and analysed using Petri nets. Petri nets was chosen because the ideas behind Petri nets and Delta concide on several points. A number of proposals for changes in Delta, which resulted from...

Plasticity in intact A delta- and C-fibers contributes to cold hypersensitivity in neuropathic rats.

Science.gov (United States)

Ji, G; Zhou, S; Kochukov, M Y; Westlund, K N; Carlton, S M

2007-11-30

Cold hypersensitivity is a common sensory abnormality accompanying peripheral neuropathies and is difficult to treat. Progress has been made in understanding peripheral mechanisms underlying neuropathic pain but little is known concerning peripheral mechanisms of cold hypersensitivity. The aim of this study was to analyze the contribution of uninjured primary afferents to the cold hypersensitivity that develops in neuropathic rats. Rats with a lumbar 5 (L5) and L6 spinal nerve ligation (SNL, Chung model) but not sham, developed mechanical allodynia, evidenced by decreased paw withdrawal thresholds and increased magnitude of response to von Frey stimulation. Cold hypersensitivity also developed in SNL but not sham rats, evidenced by enhanced nociceptive behaviors induced by placement on a cold plate (6 degrees C) or application of icilin (a transient receptor potential M8 (TRPM8)/transient receptor potential A1 (TRPA1) receptor agonist) to nerve-injured hind paws. Single fiber recordings demonstrated that the mean conduction velocities of intact L4 cutaneous A delta- and C-fibers were not different between naive and SNL rats; however, mechanical thresholds of the A delta- but not the C-fibers were significantly decreased in SNL compared with naive. There was a higher prevalence of C-mechanoheat-cold (CMHC) fibers in SNL compared with naive, but the overall percentage of cold-sensitive C-fibers was not significantly increased compared with naive. This was in contrast to the numerous changes in A delta-fibers: the percentage of L4 cold sensitive A delta-, but not C-fibers, was significantly increased, the percentage of L4 icilin-sensitive A delta-, but not C-fibers, was significantly increased, the icilin-induced activity of L4 A delta-, but not C-fibers, was significantly increased. Icilin-induced activity was blocked by the TRPA1 antagonist Ruthenium Red. The results indicate plasticity in both A delta- and C-uninjured fibers, but A delta fibers appear to provide a

C{sub 4} plant isotopic composition ({delta} {sup 13}C) evidence for urban CO{sub 2} pollution in the city of Cotonou, Benin (West Africa)

Energy Technology Data Exchange (ETDEWEB)

Kelome, Nelly C. [UMR Microbiologie et Geochimie des Sols INRA, Universite de Bourgogne, Centre des Sciences de la Terre, 6 Bd Gabriel, 21000 Dijon (France); Departement des Sciences de la Terre, Universite d' Abomey-Calavi, 01 B.P. 526, Cotonou (Benin); Leveque, Jean [UMR Microbiologie et Geochimie des Sols INRA, Universite de Bourgogne, Centre des Sciences de la Terre, 6 Bd Gabriel, 21000 Dijon (France)]. E-mail: jleveque@ubourgogne.fr; Andreux, Francis [UMR Microbiologie et Geochimie des Sols INRA, Universite de Bourgogne, Centre des Sciences de la Terre, 6 Bd Gabriel, 21000 Dijon (France); Milloux, Marie-Jeanne [UMR Microbiologie et Geochimie des Sols INRA, Universite de Bourgogne, Centre des Sciences de la Terre, 6 Bd Gabriel, 21000 Dijon (France); Oyede, Lucien-Marc [Departement des Sciences de la Terre, Universite d' Abomey-Calavi, 01 B.P. 526, Cotonou (Benin)

2006-08-01

The carbon isotopic composition ({delta} {sup 13}C) of plants can reveal the isotopic carbon content of the atmosphere in which they develop. The {delta} {sup 13}C values of air and plants depend on the amount of atmospheric fossil fuel CO{sub 2}, which is chiefly emitted in urban areas. A new indicator of CO{sub 2} pollution is tested using the {delta} {sup 13}C variation in a C{sub 4} grass: Eleusine indica. A range of about 4 per mille delta units was observed at different sites in Cotonou, the largest city in the Republic of Benin. The highest {delta} {sup 13}C values, from - 12 per mille to - 14 per mille , were found in low traffic zones; low {delta} {sup 13}C values, from - 14 per mille to - 16 per mille , were found in high traffic zones. The amount of fossil fuel carbon assimilated by plants represented about 20% of the total plant carbon content. An overall decrease in plant {delta} {sup 13}C values was observed over a four-year monitoring period. This decrease was correlated with increasing vehicle traffic. The {delta} {sup 13}C dataset and the corresponding geographical database were used to map and define zones of high and low {sup 13}C-depleted CO{sub 2} emissions in urban and sub-urban areas. The spatial distribution follows dominant wind directions, with the lowest emission zones found in the southwest of Cotonou. High CO{sub 2} emissions occurred in the north, the east and the center, providing evidence of intense anthropogenic activity related to industry and transportation.

Optimality and self-organization in river deltas

Science.gov (United States)

Tejedor, A.; Longjas, A.; Edmonds, D. A.; Zaliapin, I. V.; Georgiou, T. T.; Rinaldo, A.; Foufoula-Georgiou, E.

2017-12-01

Deltas are nourished by channel networks, whose connectivity constrains, if not drives, the evolution, functionality and resilience of these systems. Understanding the coevolution of deltaic channels and their flux organization is crucial for guiding maintenance strategies of these highly stressed systems from a range of anthropogenic activities. However, in contrast to tributary channel networks, to date, no theory has been proposed to explain how deltas self-organize to distribute water and sediment to the delta top and the shoreline. Here, we hypothesize the existence of an optimality principle underlying the self-organized partition of fluxes in delta channel networks. Specifically, we hypothesize that deltas distribute water and sediment fluxes on a given delta topology such as to maximize the diversity of flux delivery to the shoreline. By introducing the concept of nonlocal Entropy Rate (nER) and analyzing ten field deltas in diverse environments, we present evidence that supports our hypothesis, suggesting that delta networks achieve dynamically accessible maxima of their nER. Furthermore, by analyzing six simulated deltas using the Delf3D model and following their topologic and flux re-organization before and after major avulsions, we further study the evolution of nER and confirm our hypothesis. We discuss how optimal flux distributions in terms of nER, when interpreted in terms of resilience, are configurations that reflect an increased ability to withstand perturbations.

234U/238U and δ87Sr in peat as tracers of paleosalinity in the Sacramento-San Joaquin Delta of California, USA

International Nuclear Information System (INIS)

Drexler, J.Z.; Paces, J.B.; Alpers, C.N.; Windham-Myers, L.; Neymark, L.A.; Bullen, T.D.; Taylor, H.E.

2014-01-01

Highlights: • Concentrations and isotopic values of Sr and U in peat were used to trace paleosalinity. • A three-end-member mixing model was constructed using values from water sources. • Paleosalinity of peat samples was determined relative to that of end members. • δ 87 Sr values were altered during and after the California Gold Rush period. • Oligohaline and freshwater marshes have long existed in the Sacramento-San Joaquin Delta. - Abstract: The purpose of this study was to determine the history of paleosalinity over the past 6000+ years in the Sacramento-San Joaquin Delta (the Delta), which is the innermost part of the San Francisco Estuary. We used a combination of Sr and U concentrations, δ 87 Sr values, and 234 U/ 238 U activity ratios (AR) in peat as proxies for tracking paleosalinity. Peat cores were collected in marshes on Browns Island, Franks Wetland, and Bacon Channel Island in the Delta. Cores were dated using 137 Cs, the onset of Pb and Hg contamination from hydraulic gold mining, and 14 C. A proof of concept study showed that the dominant emergent macrophyte and major component of peat in the Delta, Schoenoplectus spp., incorporates Sr and U and that the isotopic composition of these elements tracks the ambient water salinity across the Estuary. Concentrations and isotopic compositions of Sr and U in the three main water sources contributing to the Delta (seawater, Sacramento River water, and San Joaquin River water) were used to construct a three-end-member mixing model. Delta paleosalinity was determined by examining variations in the distribution of peat samples through time within the area delineated by the mixing model. The Delta has long been considered a tidal freshwater marsh region, but only peat samples from Franks Wetland and Bacon Channel Island have shown a consistently fresh signal (<0.5 ppt) through time. Therefore, the eastern Delta, which occurs upstream from Bacon Channel Island along the San Joaquin River and its

Houtman Abrolhos Isotope (delta 18O, delta 13C) Data for 1795 to 1994

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — DESCRIPTION: VARIABLES AND UNITS: Column #1: core depth in mm Column #2: delta C-13 vs V-PDB Column #3: delta O-18 vs V-PDB Column #4: assigned date in years A.D....

Seasonal Variation of Eutrophication in Some Lakes of Danube Delta Biosphere Reserve.

Science.gov (United States)

Török, Liliana; Török, Zsolt; Carstea, Elfrida M; Savastru, Dan

2017-01-01

  To understand the trophic state of lakes, this study aims to determine the dynamics of phytoplankton assemblages and the main factors that influence their seasonal variation. Sampling campaigns were carried out in three lakes from the Danube Delta Biosphere Reserve. Spectral analysis of specific phytoplankton pigments was applied as a diagnostic marker to establish the distribution and composition of phytoplankton taxonomic groups. Fluorescence spectroscopy was used to quantify changes in dissolved organic matter (DOM). The relative contribution of the main phytoplankton groups to the total phytoplankton biomass and the trend of development during succession of the seasons showed that cyanobacteria could raise potential ecological or human health problems. Moreover, fluorescence spectroscopy revealed that Cryptophyta and cyanobacteria were the main contributors to the protein-like components of DOM. It was concluded that fluorescence could be used to provide a qualitative evaluation of the eutrophication degree in Danube Delta lakes.

Delta infection evidenced by radioimmunoanalysis in selected collectives

Energy Technology Data Exchange (ETDEWEB)

Kselikova, M; Horejsi, J; Urbankova, J

1987-01-01

The presence of the Delta agent within the population was tested by means of the Delta-antibody radioimmunoassay using competitive kits of the firms ABBOTT (ABBOTT-ANTI-DELTA) and SORIN (AB-DELTAK). The Delta-antibody was found in 3.2% HBV patients, 5% HBsAg carriers, and in 20.8% of specific anti-Hbs-immunoglobulin. In hemophiliacs and blood donors no Delta-antibody was seen.

Delta infection evidenced by radioimmunoanalysis in selected collectives

International Nuclear Information System (INIS)

Kselikova, M.; Horejsi, J.; Urbankova, J.

1987-01-01

The presence of the Delta agent within the population was tested by means of the Delta-antibody radioimmunoassay using competitive kits of the firms ABBOTT (ABBOTT-ANTI-DELTA) and SORIN (AB-DELTAK). The Delta-antibody was found in 3.2% HBV patients, 5% HBsAg carriers, and in 20.8% of specific anti-Hbs-immunoglobulin. In hemophiliacs and blood donors no Delta-antibody was seen. (author)

A measurement of. Delta. sigma. sub L (np), the difference between neutron-proton total cross sections in pure longitudinal spin states

Energy Technology Data Exchange (ETDEWEB)

Beddo, M.E.

1990-10-01

A measurement off {Delta}{sigma}{sub L}(np), the difference between neutron-proton total cross sections in pure longitudinal spin states, is described. The results will help determine the isospin-zero (I = 0) scattering amplitudes, which are not well known above laboratory energies of 500 MeV, whereas the isospin-one (I = 1) amplitudes are fairly well-determined to 1 GeV. Data points were taken at the Los Alamos Meson Physics Facility (LAMPF) at Los Alamos, New Mexico, for five neutron beam energies: 484, 568, 634,720 and 788 MeV; they are the first in this energy range. Polarized neutrons were produced by charge-exchange of polarized protons on a liquid deuterium target (LD{sub 2}). Large-volume neutron counters detected the neutrons that passed through a polarized proton target. The counters subtended a range of solid angles large enough to allow extrapolation of the scattered neutrons to 0{degree}. Two modifications to the LAMPF accelerator system which were made for this work are described. They included a beam buncher,'' which modified the normal rf-time structure of the proton beam and allowed for the selection of peak-energy neutrons by time-of-flight means, and a computerized beam steering program, which reduced systematic effects due to beam motion at the LD{sub 2} target. The experimental values of {Delta}{sigma}{sub L}(np) are found to be consistent with other np data, including preliminary data from SIN and Saclay, but not with some results from Argonne which used a polarized proton beam and a polarized deuteron target. The I = 0 component was extracted from {Delta}{sigma}{sub L}(np) using existing pp data (I = 1), with the unexpected result that {Delta}{sigma}{sub L}(I = 0) was found to be essentially identical in shape to {Delta}{sigma}{sub L}(I = 1). The significance of this is not yet understood.

Dermal absorption of the insecticide lindane (1 delta, 2 delta, 3 beta, 4 delta, 5 delta, 6 beta-hexachlorocyclohexane) in rats and rhesus monkeys: Effect of anatomical site

International Nuclear Information System (INIS)

Moody, R.P.; Ritter, L.

1989-01-01

Dermal absorption of the insecticide lindane (1 delta, 2 delta, 3 beta, 4 delta, 5 delta, 6 beta-hexachlorocyclohexane) was determined in rats and rhesus monkeys. Lindane is in widespread use as a 1% cream or lotion scabicide formulation and as a 1% miticide shampoo for body lice control in humans. Results obtained following our in vivo dermal absorption procedure demonstrated that 18 +/- 4.1%, 34 +/- 5.2%, and 54 +/- 26.3% of the applied dose was absorbed following topical applications at a rate of 1.5 micrograms/cm2 (6.2 micrograms/100 microliters of acetone) of the 14C-labeled pesticide to 4.2-cm2 regions of the forearm (n = 8), forehead (n = 7), and palm (n = 4) of rhesus monkeys, respectively. Dose sites were washed with soapy water 24 h posttreatment. Comparative studies in rats (n = 5) dosed middorsally demonstrated 31 +/- 9.5% absorption. Statistical analysis of the 14C excretion kinetics demonstrated slower clearance of lindane from rats than monkey forearm, forehead, or palm. Intramuscular (im) injections of 14C-lindane gave 52 +/- 7.1% recovery in monkey (n = 8) and 64 +/- 5.9% in rats (n = 5), suggesting body storage of this lipophilic chemical

Determination of the positions and residues of the. delta. /sup + +/ and. delta. /sup 0/ poles. [Phase shifts,coulomb corrections

Energy Technology Data Exchange (ETDEWEB)

Vasan, S S [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

1976-04-19

The poles and the associated residues in the ..pi..N P/sub 33/ amplitude corresponding to the resonances ..delta../sup + +/ and ..delta../sup 0/ are determined by fitting the ..pi../sup +/p and ..pi../sup -/p hadronic phase shifts from the Carter 73 analysis. The ..delta../sup + +/ and ..delta../sup 0/ pole positions are determined also from the nuclear phase shifts, these being the phase shifts made up of the hadronic phase shifts plus the Coulomb corrections. The pole positions obtained from the two sets of phase shifts are different, the differences being larger in the case of the ..delta../sup + +/.

Structural and superconducting properties of oxygen-deficient NdBa sub 2 Cu sub 3 O sub 7 minus. delta

Energy Technology Data Exchange (ETDEWEB)

Shaked, H. (Nuclear Research Center-Negev, Post Office Box 9001, Beer Sheva, Israel (IL) Ben Gurion University of the Negev, Post Office Box 653, Beer Sheva, Israel (IL)); Veal, B.W.; Faber, J. Jr.; Hitterman, R.L.; Balachandran, U.; Tomlins, G.; Shi, H.; Morss, L.; Paulikas, A.P. (Argonne National Laboratory, Argonne, Illinois 60439 (USA))

1990-03-01

Neutron diffraction was used to determine the structural properties of oxygen deficient NdBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} for 0.09{lt}{delta}{lt}0.74. It was found that superconductivity disappears at the orthorhombic-to-tetragonal phase transition which occurs at {delta}{sub {ital O}{ital T}}=0.45. Structural parameters vary smoothly with {delta} but exhibit a change in slope at the orthorhombic-to-tetragonal transition. The structural properties exhibit the same features found in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} where {delta}{sub {ital O}{ital T}}=0.65. It is shown that the repulsion energy of oxygen atoms in the O(1) and O(5) sites in NdBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} is smaller than in YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}}. This lower repulsion energy stabilizes the orthorhombic phase at lower values of {delta}. It is argued that the disappearance of superconductivity at the orthorhombic-to-tetragonal transition is an inherent property of the {ital R}Ba{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} ({ital R} denotes rare earth) system.

The Concentration Dependence of the (Delta)s Term in the Gibbs Free Energy Function: Application to Reversible Reactions in Biochemistry

Science.gov (United States)

Gary, Ronald K.

2004-01-01

The concentration dependence of (delta)S term in the Gibbs free energy function is described in relation to its application to reversible reactions in biochemistry. An intuitive and non-mathematical argument for the concentration dependence of the (delta)S term in the Gibbs free energy equation is derived and the applicability of the equation to…

78 FR 21491 - DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption...

Science.gov (United States)

2013-04-10

... SMALL BUSINESS ADMINISTRATION [License No. 02/02-0662, 02/02-0661] DeltaPoint Capital IV, L.P., DeltaPoint Capital IV (New York), L.P.; Notice Seeking Exemption Under Section 312 of the Small Business Investment Act, Conflicts of Interest Notice is hereby given that DeltaPoint Capital IV, L.P. and DeltaPoint...

Mida pakub Delta? / Teele Kurm

Index Scriptorium Estoniae

Kurm, Teele

2011-01-01

Politsei- ja Piirivalveamet võtab kasutusele ühise Siseministeeriumi infotehnoloogia- ja arenduskeskuse ning Webmedia AS koostööna loodud dokumendihaldussüsteemi Delta. Kust sai Delta oma nime? Projekti "Dokumendihaldussüsteemi juurutamine Siseministeeriumi haldusalas" eesmärgid

N* and {delta}* decays into N{pi}{sup 0}{pi}{sup 0}

Energy Technology Data Exchange (ETDEWEB)

Thoma, U. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); II. Physikalisches Institut, Universitaet Giessen (Germany); Fuchs, M. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Anisovich, A.V. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Anton, G. [Physikalisches Institut, Universitaet Erlangen (Germany); Bantes, R. [Physikalisches Institut, Universitaet Bonn (Germany); Bartholomy, O.; Beck, R. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Beloglazov, Yu. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Crede, V. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Department of Physics, Florida State University (United States); Ehmanns, A.; Ernst, J.; Fabry, I. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Flemming, H. [Physikalisches Institut, Universitaet Bochum (Germany); Foesel, A. [Physikalisches Institut, Universitaet Erlangen (Germany); Funke, Chr. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Gothe, R. [Physikalisches Institut, Universitaet Bonn (Germany); Gridnev, A. [Petersburg Nuclear Physics Institute, Gatchina (Russian Federation); Gutz, E. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany); Hoeffgen, St. [Physikalisches Institut, Universitaet Bonn (Germany); Horn, I. [Helmholtz-Institut fuer Strahlen- und Kernphysik der Universitaet Bonn (Germany)] (and others)

2008-01-17

Decays of baryon resonances in the second and the third resonance region into N{pi}{sup 0}{pi}{sup 0} are studied by photoproduction of two neutral pions off protons. Partial decay widths of N* and {delta}* resonances decaying into {delta}(1232){pi}, N({pi}{pi}){sub S}, N(1440)P{sub 11}{pi}, and N(1520)D{sub 13}{pi} are determined in a partial wave analysis of this data and of data from other reactions. Several partial decay widths were not known before. Interesting decay patterns are observed which are not even qualitatively reproduced by quark model calculations. In the second resonance region, decays into {delta}(1232){pi} dominate clearly. The N({pi}{pi}){sub S}-wave provides a significant contribution to the cross section, especially in the third resonance region. The P{sub 13}(1720) properties found here are at clear variance to PDG values.

Changes in the areal extents of the Athabasca River, Birch River, and Cree Creek Deltas, 1950-2014, Peace-Athabasca Delta, Canada

Science.gov (United States)

Timoney, Kevin; Lee, Peter

2016-04-01

Deltas form where riverborne sediment accumulates at the interface of river mouths and their receiving water bodies. Their areal extent is determined by the net effect of processes that increase their extent, such as sediment accumulation, and processes that decrease their extent, such as erosion and subsidence. Through sequential mapping and construction of river discharge and sediment histories, this study examined changes in the subaerial extents of the Cree Creek and Athabasca River Deltas (both on the Athabasca River system) and the Birch River Delta in northern Canada over the period 1950-2014. The purpose of the study was to determine how, when, and why the deltas changed in areal extent. Temporal growth patterns were similar across the Athabasca and Birch River systems indicative of a climatic signal. Little or no areal growth occurred from 1950 to 1968; moderate growth occurred between 1968 and the early to mid-1980s; and rapid growth occurred between 1992 and 2012. Factors that affected delta progradation included dredging, sediment supply, isostatic drowning, delta front bathymetry, sediment capture efficiency, and storms. In relation to sediment delivered, areal growth rates were lowest in the Athabasca Delta, intermediate in the Birch Delta, and highest in the Cree Creek Delta. Annual sediment delivery is increasing in the Cree Creek Delta; there were no significant trends in annual sediment delivery in the Birch and Athabasca Deltas. There was a lag of up to several years between sediment delivery events and progradation. Periods of delta progradation were associated with low water levels of the receiving basins. Predicted climate-change driven declines in river discharge and lake levels may accelerate delta progradation in the region. In the changing ecosystems of northeastern Alberta, inadequate monitoring of vegetation, landforms, and sediment regimes hampers the elucidation of the nature, rate, and causality of ecosystem changes.

An analytical framework for strategic delta planning

NARCIS (Netherlands)

Seijger, C.; Douven, W.; Halsema, van G.; Hermans, L.; Evers, J.; Phi, H.L.; Khan, M.F.; Brunner, J.; Pols, L.; Ligtvoet, W.; Koole, S.; Slager, K.; Vermoolen, M.S.; Hasan, S.; Thi Minh Hoang, Vo

2017-01-01

Sectoral planning on water, agriculture and urban development has not been able to prevent increased flood risks and environmental degradation in many deltas. Governments conceive strategic delta planning as a promising planning approach and develop strategic delta plans. Such plans are linked to

Optimal distribution of integration time for intensity measurements in degree of linear polarization polarimetry.

Science.gov (United States)

Li, Xiaobo; Hu, Haofeng; Liu, Tiegen; Huang, Bingjing; Song, Zhanjie

2016-04-04

We consider the degree of linear polarization (DOLP) polarimetry system, which performs two intensity measurements at orthogonal polarization states to estimate DOLP. We show that if the total integration time of intensity measurements is fixed, the variance of the DOLP estimator depends on the distribution of integration time for two intensity measurements. Therefore, by optimizing the distribution of integration time, the variance of the DOLP estimator can be decreased. In this paper, we obtain the closed-form solution of the optimal distribution of integration time in an approximate way by employing Delta method and Lagrange multiplier method. According to the theoretical analyses and real-world experiments, it is shown that the variance of the DOLP estimator can be decreased for any value of DOLP. The method proposed in this paper can effectively decrease the measurement variance and thus statistically improve the measurement accuracy of the polarimetry system.

Impurity-related nonlinear optical properties in delta-doped quantum rings: Electric field effects

Energy Technology Data Exchange (ETDEWEB)

Restrepo, R.L., E-mail: rrestre@gmail.com [Escuela de Ingeniería de Antioquia-EIA, Medellín (Colombia); Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Morales, A.L. [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Martínez-Orozco, J.C. [Unidad Académica de Física, Universidad Autónoma de Zacatecas, CP 98060, Zacatecas (Mexico); Baghramyan, H.M.; Barseghyan, M.G. [Department of Solid State Physics, Yerevan State University, Al. Manookian 1, 0025 Yerevan (Armenia); Mora-Ramos, M.E. [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Facultad de Ciencias, Universidad Autónoma del Estado de Morelos, Ave. Universidad 1001, CP 62209, Cuernavaca, Morelos (Mexico); Duque, C.A. [Grupo de Materia Condensada-UdeA, Instituto de Física, Facultad de Ciencias Exactas y Naturales, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia)

2014-11-15

Using a variational procedure within the effective mass approximation, we have calculated the donor impurity binding energy for the ground (1s-like) and the excited (2p{sub z}-like) states as well as the impurity-related nonlinear optical absorption and relative changes in the refraction index in a GaAs single quantum ring with axial n-type delta-doping. The delta-like potential along the z-direction is an approximate model analytically described using a Lorentzian function with two parameters. Additionally we consider the application of an electric field along the z-direction. It is found that the changes in the geometry of the quantum ring, the change in the 2D impurity density of the delta-like doping, and different values of the electric field lead to a shifting of the resonant peaks of the optical responses spectrum.

Impurity-related nonlinear optical properties in delta-doped quantum rings: Electric field effects

International Nuclear Information System (INIS)

Restrepo, R.L.; Morales, A.L.; Martínez-Orozco, J.C.; Baghramyan, H.M.; Barseghyan, M.G.; Mora-Ramos, M.E.; Duque, C.A.

2014-01-01

Using a variational procedure within the effective mass approximation, we have calculated the donor impurity binding energy for the ground (1s-like) and the excited (2p z -like) states as well as the impurity-related nonlinear optical absorption and relative changes in the refraction index in a GaAs single quantum ring with axial n-type delta-doping. The delta-like potential along the z-direction is an approximate model analytically described using a Lorentzian function with two parameters. Additionally we consider the application of an electric field along the z-direction. It is found that the changes in the geometry of the quantum ring, the change in the 2D impurity density of the delta-like doping, and different values of the electric field lead to a shifting of the resonant peaks of the optical responses spectrum

Spatio-temporal distributions of delta¹⁸O, delta D and salinity in the Arabian Sea: Identifying processes and controls

Digital Repository Service at National Institute of Oceanography (India)

Deshpande, R.D; Muraleedharan, P.M.; Singh, R.L.; Kumar, B.; Rao, M.S.; Dave, M.; Sivakumar, K.U.; Gupta, S.K.

the geographic distributions of the delta^18O and S; (2) in spite of a large scatter, a statistically significant delta^18O–S relationship can be identified in much of the investigated part of the AS; (3) the delta^18O– delta...

An appraisal of river erosion mitigation in the Niger Delta

International Nuclear Information System (INIS)

Aban, T. K. S.; Omuso, W. O.

1999-01-01

River erosion processes in the Niger Delta and the effectiveness of locally applied remedial measures is appraised, using information on channel geometry, flow velocity distribution, soil type, stratification, bank height and steepness, state of compaction, together with pool level variation in river channels. High flow velocity and bank height were identified as the major erosion causative factors. Local responses towards erosion mitigation have involved structural methods to varying degree of success. River training has been recommended as a long - term regional approach to mitigate river bank erosion. However, in the short -term revetments, concrete and sheets piles may be applied cautiously

Po2 temperature blood factor for blood gas apparatus.

Science.gov (United States)

Teisseire, B P; Hérigault, R A; Teisseire, L J; Laurent, D N

1984-01-01

PO2 temperature formulae supplied by manufacturers on automatic blood gas apparatus, PO2 corr. = PO2 37 degrees C X 10F X delta T were studied and compared to the experimental determination of the delta log PO2/delta T ratio (Hérigault et al. [10]). Acid-base status at 37 degrees C appeared to have a measurable influence on the PO2 temperature factor; alkalosis increased the delta log PO2/delta T ratio, and the contrary was found for acidosis in comparison with normal acid-base status at 37 degrees C. For the same PO2, measured at 37 degrees C, all the proposed formulae of commercial blood gas automatic apparatus did not give the same temperature corrected PO2. The observed difference between the corrected PO2 may be important and greater than the precision of the initial measurement. To correct the measured PO2 for temperature, a relationship between delta log PO2/delta T and PO2 is proposed, between PO2 zero and PO2 180 mmHg, which takes into account measured pH and PO2 values at 37 degrees C:delta log PO2/delta T = [(-0.35 pH + 0.658) X 10(-4) X PO2] + 0.035.

Drug testing data from the 2007 Pan American Games: delta13C values of urinary androsterone, etiocholanolone and androstanediols determined by GC/C/IRMS.

Science.gov (United States)

Aguilera, Rodrigo; Chapman, Thomas E; Pereira, Henrique; Oliveira, Giselle C; Illanes, Renata P; Fernandes, Telma F; Azevedo, Débora A; Neto, Francisco Aquino

2009-07-01

The main purpose of this article is to show the application of the CG/C/IRMS in real time during competition in the steroid confirmation analysis. For this reason, this paper summarizes the results obtained from the doping control analysis during the period of the 2007 Pan American Games held in Rio de Janeiro, Brazil. Approximately 5600 athletes from 42 different countries competed in the games. Testing was performed in accordance to World Anti-Doping Agency (WADA) technical note for prohibited substances. This paper reports data where abnormal urinary steroid profiles, have been found with the screening procedures. One 8 mL urine sample was used for the analysis of five steroid metabolites with two separate analyses by gas chromatography/combustion/isotope ratio mass spectrometry (GC/C/IRMS). Urine samples were submitted to GC/C/IRMS for confirmation analysis to determine the (13)C/(12)C ratio of selected steroids. Fifty-seven urine samples were analyzed by GC/C/IRMS and the delta(13)C values ( per thousand) of androsterone, etiocholanolone, 5beta-androstane-3alpha, 17beta-diol (5beta-diol), 5alpha-androstane-3alpha, 17beta-diol (5alpha-diol) and 5beta-pregnane-3alpha, 20alpha-diol (5beta-pdiol), the endogenous reference compound are presented. One urine sample with a testosterone/epitestosterone (T/E) ratio of 4.7 was confirmed to be positive of doping by GC/C/IRMS analysis. The delta values of 5beta-diol and 5alpha-diol were 3.8 and 10.8, respectively, compared to the endogenous reference compound 5beta-pdiol, which exceeded the WADA limit of 3 per thousand. The results obtained by CG/C/IRMS confirmation analyses, in suspicious samples, were conclusive in deciding whether or not a doping steroid violation had occurred.

Adaptive Delta Management: cultural aspects of dealing with uncertainty

Science.gov (United States)

Timmermans, Jos; Haasnoot, Marjolijn; Hermans, Leon; Kwakkel, Jan

2016-04-01

Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy, metropolization) and cultural (multi-ethnic) perspectives. This multi-faceted dynamic character of delta areas warrants the emergence of a branch of applied adaptation science, Adaptive Delta Management, which explicitly focuses on climate adaptation of such highly dynamic and deeply uncertain systems. The application of Adaptive Delta Management in the Dutch Delta Program and its active international dissemination by Dutch professionals results in the rapid dissemination of Adaptive Delta Management to deltas worldwide. This global dissemination raises concerns among professionals in delta management on its applicability in deltas with cultural conditions and historical developments quite different from those found in the Netherlands and the United Kingdom where the practices now labelled as Adaptive Delta Management first emerged. This research develops an approach and gives a first analysis of the interaction between the characteristics of different approaches in Adaptive Delta Management and their alignment with the cultural conditions encountered in various delta's globally. In this analysis, first different management theories underlying approaches to Adaptive Delta Management as encountered in both scientific and professional publications are identified and characterized on three dimensions: The characteristics dimensions used are: orientation on today, orientation on the future, and decision making (Timmermans, 2015). The different underlying management theories encountered are policy analysis, strategic management, transition management, and adaptive management. These four management theories underlying different approaches in Adaptive Delta Management are connected to

Complex rearrangements within the human J delta-C delta/J alpha-C alpha locus and aberrant recombination between J alpha segments

NARCIS (Netherlands)

Baer, R.; Boehm, T.; Yssel, H.; Spits, H.; Rabbitts, T. H.

1988-01-01

We have examined DNA rearrangements within a 120 kb cloned region of the human T cell receptor J delta-C delta/J alpha-C alpha locus. Three types of pattern emerge from an analysis of T cell lines and clones. Firstly, cells with two rearrangements within J delta-C delta; secondly, cells with one

Sediment and Vegetation Controls on Delta Channel Networks

Science.gov (United States)

Lauzon, R.; Murray, A. B.; Piliouras, A.; Kim, W.

2016-12-01

Numerous factors control the patterns of distributary channels formed on a delta, including water and sediment discharge, grain size, sea level rise rates, and vegetation type. In turn, these channel networks influence the shape and evolution of a delta, including what types of plant and animal life - such as humans - it can support. Previous fluvial modeling and flume experiments, outside of the delta context, have addressed how interactions between sediment and vegetation, through their influence on lateral transport of sediment, determine what type of channel networks develops. Similar interactions likely also shape delta flow patterns. Vegetation introduces cohesion, tending to reduce channel migration rates and strengthen existing channel banks, reinforcing existing channels and resulting in localized, relatively stable flow patterns. On the other hand, sediment transport processes can result in lateral migration and frequent switching of active channels, resulting in flow resembling that of a braided stream. While previous studies of deltas have indirectly explored the effects of vegetation through the introduction of cohesive sediment, we directly incorporate key effects of vegetation on flow and sediment transport into the delta-building model DeltaRCM to explore how these effects influence delta channel network formation. Model development is informed by laboratory flume experiments at UT Austin. Here we present initial results of experiments exploring the effects of sea level rise rate, sediment grain size, vegetation type, and vegetation growth rate on delta channel network morphology. These results support the hypothesis that the ability for lateral transport of sediment to occur plays a key role in determining the evolution of delta channel networks and delta morphology.

Variation in MERRA-2 aerosol optical depth over the Yangtze River Delta from 1980 to 2016

Science.gov (United States)

Sun, Enwei; Che, Huizheng; Xu, Xiaofeng; Wang, Zhenzhu; Lu, Chunsong; Gui, Ke; Zhao, Hujia; Zheng, Yu; Wang, Yaqiang; Wang, Hong; Sun, Tianze; Liang, Yuanxin; Li, Xiaopan; Sheng, Zhizhong; An, Linchang; Zhang, Xiaoye; Shi, Guangyu

2018-05-01

In this study, 765 instantaneous MERRA-2 (second Modern-Era Retrospective analysis for Research and Applications) aerosol optical depth (AOD) values at 550 nm were compared with those of a sky radiometer in Hefei (31.90° N, 117.17° E) for the different seasons from March 2007 to February 2010. The correlation coefficients (R) were 0.88, 0.83, 0.88, and 0.80 in spring, summer, autumn, and winter, respectively. The MERRA-2 AOD is also compared with MODIS Aqua AOD in the entire Yangtze River Delta, and good agreement has been obtained. The MERRA-2 AOD product was used to analyze the spatial distribution and temporal variation of the annual, seasonal and monthly means of the AOD over the Yangtze River Delta region from 1980 to 2016 (37 years). The mean values of the MERRA-2 AOD during the study period show that the AOD (between 0.45 and 0.55) in the northern area of the Yangtze River Delta was higher than that (between 0.30 and 0.45) of the southern area. The northwest part of the Yangtze River Delta had the highest mean AOD values (between 0.50 and 0.55). The AOD increased slowly in the 1980s and 1990s, followed by a rapid increase between 2001 and 2010. An AOD decrease can be seen from 2011 to 2016. The mean AOD in each month is discussed. High AOD was observed in March, April, and June, while low AOD could be seen in September, October, November, and December. Three different area types (large cities, medium-sized cities, and remote areas) had nearly the same annual AOD variation. Large cities had the highest AOD (about 0.48), while remote areas had the lowest (about 0.42). In summer, the AOD in remote areas was much lower than that in cities. The AOD variational trend over the Yangtze River Delta was studied during two periods. The increasing trend could be seen over the entire Yangtze River Delta in each month from 1980 to 2009. A decreasing trend was found all over the Yangtze River Delta in January, February, March, July, October, and November, whereas in

Solution matching for a three-point boundary-value problem on atime scale

Directory of Open Access Journals (Sweden)

Martin Eggensperger

2004-07-01

Full Text Available Let $mathbb{T}$ be a time scale such that $t_1, t_2, t_3 in mathbb{T}$. We show the existence of a unique solution for the three-point boundary value problem $$displaylines{ y^{DeltaDeltaDelta}(t = f(t, y(t, y^Delta(t, y^{DeltaDelta}(t, quad t in [t_1, t_3] cap mathbb{T},cr y(t_1 = y_1, quad y(t_2 = y_2, quad y(t_3 = y_3,. }$$ We do this by matching a solution to the first equation satisfying a two-point boundary conditions on $[t_1, t_2] cap mathbb{T}$ with a solution satisfying a two-point boundary conditions on $[t_2, t_3] cap mathbb{T}$.

132 Tanure Ojaide: The Poet-Priest of the Niger-Delta and the Land ...

African Journals Online (AJOL)

User

Oil detection in the Niger Delta has had multifarious effects on the Nigerian ..... receives infinite respect and reverence from the people, and to this day, a cult .... appellations, sea animals and bird names and value placements form the oral.

Coral skeletal {delta}{sup 15}N reveals isotopic traces of an agricultural revolution

Energy Technology Data Exchange (ETDEWEB)

Marion, Guy S. [Department of Biological Sciences, Stanford University, Stanford, CA 94305 (United States)]. E-mail: g.marion@uq.edu.au; Dunbar, Robert B. [Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305 (United States); Mucciarone, David A. [Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305 (United States); Kremer, James N. [Department of Marine Sciences, University of Connecticut at Avery Point, Groton, CT 06340 (United States); Lansing, J. Stephen [Department of Anthropology, University of Arizona, Tucson, AZ 85721 (United States); Arthawiguna, Alit [Installation for Agricultural Research (IP 2TP), Kotak Pos 3480, Denpasar, Bali (Indonesia)

2005-09-01

This study introduces a new method of tracing the history of nutrient loading in coastal oceans via {delta}{sup 15}N analysis of organic nitrogen preserved in the skeleton of the massive Porites coral. Four coral cores were collected in Bali, Indonesia, from reefs exposed to high levels of fertilizers in agricultural run-off, from lagoonal corals impacted by sewage, and from a reef located 30 km offshore. Skeletal {delta}{sup 15}N in the agriculturally exposed coral declined from 10.7 {+-} 0.4 per mille in 1970-1971, when synthetic fertilizers (-0.8 per mille {+-} 0.2 per mille ) were introduced to Bali, to a depleted 'anthropogenic' baseline of 3.5 per mille {+-} 0.4% in the mid-1990s. {delta}{sup 15}N values were negatively correlated with rainfall, suggesting that marine {delta}{sup 15}N lowers during flood-born influxes of waste fertilizers. Reef cores exposed to untreated sewage in terrestrial discharge were enriched (7.8 and 7.3 {+-} 0.4 per mille ), while the offshore core reflected background oceanic signals (6.2 {+-} 0.4 per mille). {delta}{sup 15}N, N concentration, and C:N systematics indicate that the N isotopic composition of skeletal organic matter was generally well preserved over 30 years. We suggest that skeletal organic {delta}{sup 15}N can serve as a recorder of past nitrogen sources. In Bali, this tracer suggests that the intensification of Western style agricultural practices since 1970 are contributing to the degradation of coastal coral reefs.

Facilitating Adaptive Management in California’s Sacramento–San Joaquin Delta

Directory of Open Access Journals (Sweden)

John A. Wiens

2017-07-01

Full Text Available https://doi.org/10.15447/sfews.2017v15iss2art3Uncertainties in understanding ecosystems increase the risk that management will fail to achieve desired results. Adaptive management is a structured, iterative application of science-based knowledge to reduce uncertainties and build flexibility into decision-making. However, adaptive management is more easily planned than implemented, and it is only beginning to be applied in the California’s Sacramento–San Joaquin Delta. We draw from two assessments of adaptive management in the Delta and examples of its use elsewhere to suggest how the process can be facilitated. Although a highly structured adaptive-management process may not always be needed, several elements are essential. Adaptive management should begin by clearly identifying the problem, goals, and objectives; recognizing uncertainties; identifying decision points and alternative approaches; recognizing when adjustments are needed and having the flexibility to make them; and considering societal and political constraints. Model complexity should be matched to that of the system and management needs; experiments can help unravel causal relationships. Monitoring, analyses, and syntheses require comprehensive data-management systems. More frequent and organized communications among scientists, managers, stakeholders, and decision-makers are necessary. We propose the establishment of an “Adaptive Management Team” to coordinate efforts across the management spectrum of the Delta and to provide guidance and link individual projects to shared approaches and experiences. Reliable long-term support will be needed to assess results of management actions, adjust approaches where improvement is likely, and strive toward the legislated goals of enhancing the Delta ecosystem while also providing reliable water supplies to much of California, and doing both these things in a manner that protects values of the Delta as a place where people live and

Late quaternary evolution of the Orinoco Delta, Venezuela

Science.gov (United States)

Warne, A.G.; Guevara, E.H.; Aslan, A.

2002-01-01

The modern Orinoco Delta is the latest of a series of stacked deltas that have infilled the Eastern Venezuelan Basin (EVB) since the Oligocene. During the late Pleistocene sea-level lowstand (20,000 to 16,000 yrs BP), bedrock control points at the position of the present delta apex prevented the river channel from incising as deeply as many other major river systems. Shallow seismic data indicate that the late Pleistocene Orinoco incised into the present continental shelf, where it formed a braided-river complex that transported sediment to a series of shelf-edge deltas. As sea level rose from 16,000 to 9,500 yrs BP, the Orinoco shoreline shifted rapidly landward, causing shallow-marine waves and currents to form a widespread transgressive sand unit. Decelerating sea-level rise and a warmer, wetter climate during the early Holocene (9,500 to 6,000 yrs BP) induced delta development within the relatively quiet-water environment of the EVB embayment. Sea level approached its present stand in the middle Holocene (6,000 to 3,000 yrs BP), and the Orinoco coast prograded, broadening the delta plain and infilling the EVB embayment. Significant quantities of Amazon sediment began to be transported to the Orinoco coast by littoral currents. Continued progradation in the late Holocene caused the constriction at Boca de Serpientes to alter nearshore and shelf hydrodynamics and subdivide the submarine delta into two distinct areas: the Atlantic shelf and the Gulf of Paria. The increased influence of littoral currents along the coast promoted mudcape development. Because most of the water and sediment were transported across the delta plain through the Rio Grande distributary in the southern delta, much of the central and northwestern delta plain became sediment starved, promoting widespread accumulation of peat deposits. Human impacts on the delta are mostly associated with the Volca??n Dam on Can??o Manamo. However, human activities have had relatively little effect on the

Involvement of the yeast DNA polymerase delta in DNA repair in vivo

Energy Technology Data Exchange (ETDEWEB)

Giot, L. [State University of New York at Stony Brook, Stony Brook, NY. (United States); Chanet, R.; Simon, M.; Facca, C.; Faye, G.

1997-08-15

The POL3 encoded catalytic subunit of DNA polymerase delta possesses a highly conserved C-terminal cysteine-rich domain in Saccharomyces cerevisiae. Mutations in some of its cysteine codons display a lethal phenotype, which demonstrates an essential function of this domain. The thermosensitive mutant pol3-13, in which a serine replaces a cysteine of this domain, exhibits a range of defects in DNA repair, such as hypersensitivity to different DNA-damaging agents and deficiency for induced mutagenesis and for recombination. These phenotypes are observed at 24 degrees, a temperature at which DNA replication is almost normal; this differentiates the functions of POL3 in DNA repair and DNA replication. Since spontaneous mutagenesis and spontaneous recombination are efficient in pol3-13, we propose that POL3 plays an important role in DNA repair after irradiation, particularly in the error-prone and recombinational pathways. Extragenic suppressors of pol3-13 are allelic to sdp5-1, previously identified as an extragenic suppressor of pol3-11. SDP5, which is identical to HYS2, encodes a protein homologous to the p50 subunit of bovine and human DNA polymerase delta. SDP5 is most probably the p55 subunit of Pol delta of S. cerevisiae and seems to be associated with the catalytic subunit for both DNA replication and DNA repair. (author)

Supply Chain Management for Sustainable Development: Perspective from the Greater Pearl River Delta (China)

OpenAIRE

Tsoi, Joyce

2006-01-01

This thesis was submitted for the degree of Doctor of Philosophy and awarded by the University of Hong Kong. This thesis investigates the application and implications of supply chain management as a modern management model in regulating corporate outsourcing activities within the Greater Pearl River Delta. Globalisation has accelerated the application of supply chain management as a mechanism to enhance corporate performance. At the same time this rapid economic development has also accele...

Conceptualizing delta forms and processes in Arctic coastal environments

DEFF Research Database (Denmark)

Bendixen, Mette; Kroon, Aart

2017-01-01

Climate warming in the Arctic directly causes two opposite changes in Arctic coastal systems: increased melt-water discharge through rivers induces extra influx of sediments and extended open water season increases wave impact which reworks and erodes the shores. A shoreline change analysis along...... and popped up as hotspots. The Tuapaat delta and Skansen delta showed large progradation rates (1.5 and 7m/yr) and migration of the adjacent barriers and spits. The dynamic behavior at the delta mouths was mainly caused by classic delta channel lobe switching at one delta (Tuapaat), and by a breach...... of the fringing spit at the other delta (Skansen). The longshore and cross-shore transports are responsible for reworking the sediment with a result of migrating delta mouths and adjacent subaqueous mouth bars. Seaward progradation of the deltas is limited due to the steep nature of the bathymetry in Disko Bay...

Delta-ray spectroscopy of quasi-atoms

International Nuclear Information System (INIS)

Kozhuharov, C.

1983-01-01

The spectroscopy of high energy delta-rays, emitted in collisions of very heavy ions, is studied. The ''orange''-type beta-spectrometer and the achromatic electron channel are the experimental setups. Delta ray production probabilities are studied as a function of the distance of closest approach R /SUB min/ or the impact parameter b. Coulomb ionization, ion trajectory, scaling laws, double differential cross sections, and K-X-rays information is extracted from the experiment. The dependence of delta-ray emission on the united charge number Z /SUB u/ is discussed. Asymmetric collision systems with Z x alpha approx. = 1 (delta ray spectrum from Pb→Sn collisions) are studied. Finally, very heavy collisions, such as 208 Pb + 208 Pb collisions at bombarding energy fas below the Coulomb barrier are touched upon

Multimode delta-E effect magnetic field sensors with adapted electrodes

Energy Technology Data Exchange (ETDEWEB)

Zabel, Sebastian; Fichtner, Simon; Kirchhof, Christine; Quandt, Eckhard; Faupel, Franz, E-mail: ff@tf.uni-kiel.de [Faculty of Engineering, Institute for Materials Science, Kiel University, Kaiserstraße 2, 24143 Kiel (Germany); Reermann, Jens; Schmidt, Gerhard [Faculty of Engineering, Institute for Electrical Engineering, Kiel University, Kaiserstraße 2, 24143 Kiel (Germany); Wagner, Bernhard [Fraunhofer Institute for Silicon Technology ISIT, Fraunhoferstraße 1, 25524 Itzehoe (Germany)

2016-05-30

We present an analytical and experimental study on low-noise piezoelectric thin film resonators that utilize the delta-E effect of a magnetostrictive layer to measure magnetic fields at low frequencies. Calculations from a physical model of the electromechanical resonator enable electrode designs to efficiently operate in the first and second transversal bending modes. As predicted by our calculations, the adapted electrode design improves the sensitivity by a factor of 6 and reduces the dynamic range of the sensor output by 16 dB, which significantly eases the requirements on readout electronics. Magnetic measurements show a bandwidth of 100 Hz at a noise level of about 100 pTHz{sup −0.5}.

Cold dark matter and degree-scale cosmic microwave background anisotropy statistics after COBE

Science.gov (United States)

Gorski, Krzysztof M.; Stompor, Radoslaw; Juszkiewicz, Roman

1993-01-01

We conduct a Monte Carlo simulation of the cosmic microwave background (CMB) anisotropy in the UCSB South Pole 1991 degree-scale experiment. We examine cold dark matter cosmology with large-scale structure seeded by the Harrison-Zel'dovich hierarchy of Gaussian-distributed primordial inhomogeneities normalized to the COBE-DMR measurement of large-angle CMB anisotropy. We find it statistically implausible (in the sense of low cumulative probability F lower than 5 percent, of not measuring a cosmological delta-T/T signal) that the degree-scale cosmological CMB anisotropy predicted in such models could have escaped a detection at the level of sensitivity achieved in the South Pole 1991 experiment.

Adaptive delta management : Roots and branches

NARCIS (Netherlands)

Timmermans, J.S.; Haasnoot, M.; Hermans, L.M.; Kwakkel, J.H.; Rutten, M.M.; Thissen, W.A.H.

2015-01-01

Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy,

Adaptive Delta Management : Roots and Branches

NARCIS (Netherlands)

Timmermans, Jos; Haasnoot, Marjolijn; Hermans, Leon; Kwakkel, Jan H.; Rutten, Maarten; Thissen, Wil A.H.; Mynett, Arthur

2015-01-01

Deltas are generally recognized as vulnerable to climate change and therefore a salient topic in adaptation science. Deltas are also highly dynamic systems viewed from physical (erosion, sedimentation, subsidence), social (demographic), economic (trade), infrastructures (transport, energy,

Undergraduate Perceptions of Value: Degree Skills and Career Skills

Science.gov (United States)

Galloway, Kyle W.

2017-01-01

Recent data suggests that of the UK students graduating with a degree in chemistry in 2015, only 18.9% continued to employment as "Science Professionals". While this shows the wide range of employment that is available for chemistry graduates, it also highlights the need for them to have relevant transferable skills, rather than just the…

Adulteration of honey : relation between microscopic analysis and delta C-13 measurements

NARCIS (Netherlands)

Kerkvliet, JD; Meijer, HAJ

2000-01-01

Upon routine microscopic analysis of some honey samples, parenchyma cells, single rings of ring vessels and epidermal cells are found. These cells originate from the sugar cane stem. We investigated whether there was a relation between these plant fragments and the delta C-13 value of honey. 17

delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.

Science.gov (United States)

Cahoon, E B; Cranmer, A M; Shanklin, J; Ohlrogge, J B

1994-11-04

delta 6 Hexadecenoic acid (16:1 delta 6) composes more than 80% of the seed oil of Thunbergia alata. Studies were conducted to determine the biosynthetic origin of the double bond of this unusual fatty acid. Assays of fractions of developing T. alata seed endosperm with [1-14C]palmitoyl (16:0)-acyl carrier protein (ACP) revealed the presence of a soluble delta 6 desaturase activity. This activity was greatest when 16:0-ACP was provided as a substrate, whereas no desaturation of the coenzyme A ester of this fatty acid was detected. In addition, delta 6 16:0-ACP desaturase activity in T. alata endosperm extracts was dependent on the presence of ferredoxin and molecular oxygen and was stimulated by catalase. To further characterize this enzyme, a cDNA encoding a diverged acyl-ACP desaturase was isolated from a T. alata endosperm cDNA library using polymerase chain reaction with degenerate oligonucleotides corresponding to conserved amino acid sequences in delta 9 stearoyl (18:0)- and delta 4 16:0-ACP desaturases. The primary structure of the mature peptide encoded by this cDNA shares 66% identity with the mature castor delta 9 18:0-ACP desaturase and 57% identity with the mature coriander delta 4 16:0-ACP desaturase. Extracts of Escherichia coli that express the T. alata cDNA catalyzed the delta 6 desaturation of 16:0-ACP. These results demonstrate that 16:1 delta 6 in T. alata endosperm is formed by the activity of a soluble delta 6 16:0-ACP desaturase that is structurally related to the delta 9 18:0- and delta 4 16:0-ACP desaturases. Implications of this work to an understanding of active site structures of acyl-ACP desaturases are discussed.

Migration in Vulnerable Deltas: A Research Strategy

Science.gov (United States)

Hutton, C.; Nicholls, R. J.; Allan, A.

2015-12-01

C. Hutton1, & R. J. Nicholls1, , 1 University of Southampton, University Road, Southampton, Hampshire, United Kingdom, SO17 1BJ. cwh@geodata. soton.ac.ukAbstractGlobally, deltas contain 500 million people and with rising sea levels often linked to large number of forced migrants are expected in the coming century. However, migration is already a major process in deltas, such as the growth of major cities such as Dhaka and Kolkata. Climate and environmental change interacts with a range of catchment and delta level drivers, which encompass a nexus of sea-level rise, storms, freshwater and sediment supply from the catchment, land degradation, subsidence, agricultural loss and socio-economic stresses. DECCMA (Deltas, Vulnerability and Climate Change: Migration and Adaptation/CARRIA) is investigating migration in the Ganges-Brahmaputra-Meghna (GBM), Mahanadi and Volta Deltas, including the influence of climate change. The research will explore migration from a range of perspectives including governance and stakeholder analysis, demographic analysis, household surveys of sending and receiving areas, macro-economic analysis, and hazards and hotspot analysis both historically and into the future. Migration under climate change will depend on other adaptation in the deltas and this will be examined. Collectively, integrated analysis will be developed to examine migration, other adaptation and development pathways with a particular focus on the implications for the poorest. This will require the development of input scenarios, including expert-derived exogenous scenarios (e.g., climate change) and endogenous scenarios of the delta developed in a participatory manner. This applied research will facilitate decision support methods for the development of deltas under climate change, with a focus on migration and other adaptation strategies.

Free radical-scavenging delta-lactones from Boletus calopus.

Science.gov (United States)

Kim, Jin-Woo; Yoo, Ick-Dong; Kim, Won-Gon

2006-12-01

The methanol extracts from the fruiting body of the mushroom Boletus calopus showed free radical-scavenging activity. Bioactivity-guided fractionation of the methanol extracts led to a new hydroxylated calopin named calopin B, along with the known delta-lactones calopin and cyclocalopin A. The structure of the new calopin analogue was elucidated by spectroscopic methods. All compounds showed potent free radical-scavenging activity against superoxide, DPPH, and ABTS radicals with IC (50) values of 1.2 - 5.4 microg/mL.

Upper-division student difficulties with the Dirac delta function

Directory of Open Access Journals (Sweden)

Bethany R. Wilcox

2015-03-01

Full Text Available The Dirac delta function is a standard mathematical tool that appears repeatedly in the undergraduate physics curriculum in multiple topical areas including electrostatics, and quantum mechanics. While Dirac delta functions are often introduced in order to simplify a problem mathematically, students still struggle to manipulate and interpret them. To characterize student difficulties with the delta function at the upper-division level, we examined students’ responses to traditional exam questions and a standardized conceptual assessment, and conducted think-aloud interviews. Our analysis was guided by an analytical framework that focuses on how students activate, construct, execute, and reflect on the Dirac delta function in the context of problem solving in physics. Here, we focus on student difficulties using the delta function to express charge distributions in the context of junior-level electrostatics. Common challenges included invoking the delta function spontaneously, translating a description of a charge distribution into a mathematical expression using delta functions, integrating 3D or non-Cartesian delta function expressions, and recognizing that the delta function can have units. We also briefly discuss implications of these difficulties for instruction.

Measurement of the total cross section difference {Delta}{sigma}{sub L} in np transmission at 1.19, 2.49 and 3.65 GeV

Energy Technology Data Exchange (ETDEWEB)

Averichev, S.A. [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Lab. of High Energy; Azhgirey, L.S. [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Lab. of Nuclear Problems; Benda, B. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee; Adiasevich, B.P. [Russian Research Centre Kurchatov Inst., Moscow (Russian Federation); Ball, J. [Laboratoire National Saturne - Centre d`Etudes Nucleaires de Saclay, 91 - Gif-sur-Yvette (France); Bazhanov, N.A. [AN SSSR, Leningrad (Russian Federation). Inst. Yadernoj Fiziki; Dzyubak, A.P. [AN Ukrainskoj SSR, Kharkov (Ukraine). Fiziko-Tekhnicheskij Inst.; Fedorov, A.N. [Joint Inst. for Nuclear Research, Dubna (Russian Federation). Lab. of Particle Physics; Grosnick, D.P. [Argonne National Lab., IL (United States). High Energy Physics Div.; Gurevich, G.M. [AN SSSR, Moscow (Russian Federation). Inst. Yadernykh Issledovanij] [and others

1996-01-01

Results of the total cross section difference {Delta}{sigma}{sub L} in a np transmission experiment are presented. Results were obtained with a polarized beam of free quasi-monochromatic neutrons passing through the new Dubna frozen spin proton target. The beam and target polarizations were oriented longitudinally. The new results are compared with {Delta}{sigma}{sub L}(pn) data determined as a difference between {Delta}{sigma}{sub L}(pd) and {Delta}{sigma}{sub L}(pp) ANL-ZGS measurements. The values of {Delta}{sigma}{sub L} for the isospin state I=0 were deduced using known pp data. (author). Submitted to Zeitschrift fuer Physik, C (DE); 51 refs.

On the origin of delta spots

International Nuclear Information System (INIS)

Tang, F.

1983-01-01

Mount Wilson sunspot drawings from 1966 through 1980 were used in conjunction with Hα filtergrams from Big Bear Solar Observatory to examine the origin of delta spots, spots with bipolar umbrae within one penumbra. Of the six cases we studied, five were formed by the union of non-paired spots. They are either shoved into one another by two neighboring growing bipoles or by a new spot born piggy-back style on an existing spot of opposite polarity. Proper motions of the growing spots take on curvilinear paths around one another to avoid a collision. This is the shear motion observed in delta spots (Tanaka, 1979). In the remaining case, the delta spot was formed by spots that emerged as a pair. Our findings indicate no intrinsic differences in the formation or the behavior between delta spots of normal magnetic configuration. (orig.)

Holocene evolution of the western Orinoco Delta, Venezuela

Science.gov (United States)

Aslan, A.; White, W.A.; Warne, A.G.; Guevara, E.H.

2003-01-01

The pristine nature of the Orinoco Delta of eastern Venezuela provides unique opportunities to study the geologic processes and environments of a major tropical delta. Remote-sensing images, shallow cores, and radiocarbon-dating of organic remains form the basis for describing deltaic environments and interpreting the Holocene history of the delta. The Orinoco Delta can be subdivided into two major sectors. The southeast sector is dominated by the Rio Grande-the principal distributary-and complex networks of anastomosing fluvial and tidal channels. The abundance of siliciclastic deposits suggests that fluvial processes such as over-bank flooding strongly influence this part of the delta. In contrast, the northwest sector is represented by few major distributaries, and overbank sedimentation is less widespread relative to the southeast sector. Peat is abundant and occurs in herbaceous and forested swamps that are individually up to 200 km2 in area. Northwest-directed littoral currents transport large volumes of suspended sediment and produce prominent mudcapes along the northwest coast. Mapping of surface sediments, vegetation, and major landforms identified four principal geomorphic systems within the western delta plain: (1) distributary channels, (2) interdistributary flood basins, (3) fluvial-marine transitional environments, and (4) marine-influenced coastal environments. Coring and radiocarbon dating of deltaic deposits show that the northern delta shoreline has prograded 20-30 km during the late Holocene sea-level highstand. Progradation has been accomplished by a combination of distributary avulsion and mudcape progradation. This style of deltaic progradation differs markedly from other deltas such as the Mississippi where distributary avulsion leads to coastal land loss, rather than shoreline progradation. The key difference is that the Orinoco Delta coastal zone receives prodigious amounts of sediment from northwest-moving littoral currents that transport

Valence band states in Si-based p-type delta-doped field effect transistors

Energy Technology Data Exchange (ETDEWEB)

Martinez-Orozco, J C; Vlaev, Stoyan J, E-mail: jcmover@correo.unam.m [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Calzada Solidaridad esquina con Paseo la Bufa S/N, C.P. 98060, Zacatecas, Zac. (Mexico)

2009-05-01

We present tight-binding calculations of the hole level structure of delta-doped Field Effect Transistor in a Si matrix within the first neighbors sp{sup 3}s* semi-empirical tight-binding model including spin. We employ analytical expressions for Schottky barrier potential and the p-type delta-doped well based on a Thomas-Fermi approximation, we consider these potentials as external ones, so in the computations they are added to the diagonal terms of the tight-binding Hamiltonian, by this way we have the possibility to study the energy levels behavior as we vary the backbone parameters in the system: the two-dimensional impurity density (p{sub 2d}) of the p-type delta-doped well and the contact voltage (V{sub c}). The aim of this calculation is to demonstrate that the tight-binding approximation is suitable for device characterization that permits us to propose optimal values for the input parameters involved in the device design.

Extended trigonometric Cherednik algebras and nonstationary Schrödinger equations with delta-potentials

International Nuclear Information System (INIS)

Hartwig, J. T.; Stokman, J. V.

2013-01-01

We realize an extended version of the trigonometric Cherednik algebra as affine Dunkl operators involving Heaviside functions. We use the quadratic Casimir element of the extended trigonometric Cherednik algebra to define an explicit nonstationary Schrödinger equation with delta-potential. We use coordinate Bethe ansatz methods to construct solutions of the nonstationary Schrödinger equation in terms of generalized Bethe wave functions. It is shown that the generalized Bethe wave functions satisfy affine difference Knizhnik-Zamolodchikov equations as functions of the momenta. The relation to the vector valued root system analogs of the quantum Bose gas on the circle with delta-function interactions is indicated.

Attitudes and beliefs affect frequency of eating out in the Lower Mississippi Delta

Science.gov (United States)

Attitudes and beliefs reflecting cultural values can have a positive or negative influence on eating behaviors. Eating out may negatively affect diet quality through increased fat intake and larger portion sizes. In a representative sample of the Lower Mississippi Delta (LMD) consisting of 1601 Af...

Hot deformation behavior of delta-processed superalloy 718

Energy Technology Data Exchange (ETDEWEB)

Wang, Y., E-mail: wangyanhit@yahoo.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083 (China); School of Aeronautics and Astronautics, Central South University, Changsha 410083 (China); Shao, W.Z.; Zhen, L.; Zhang, B.Y. [School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001 (China)

2011-03-25

Research highlights: {yields} The peak stress for hot deformation can be described by the Z parameter. {yields} The grain size of DRX was inversely proportional to the Z parameter. {yields} The dissolution of {delta} phases was greatly accelerated under hot deformation. {yields}The {delta} phase stimulated nucleation can serve as the main DRX mechanism. - Abstract: Flow stress behavior and microstructures during hot compression of delta-processed superalloy 718 at temperatures from 950 to 1100 deg. C with strain rates of 10{sup -3} to 1 s{sup -1} were investigated by optical microscopy (OM), electron backscatter diffraction (EBSD) technique and transmission electron microscopy (TEM). The relationship between the peak stress and the deformation conditions can be expressed by a hyperbolic-sine type equation. The activation energy for the delta-processed superalloy 718 is determined to be 467 kJ/mol. The change of the dominant deformation mechanisms leads to the decrease of stress exponent and the increase of activation energy with increasing temperature. The dynamically recrystallized grain size is inversely proportional to the Zener-Hollomon (Z) parameter. It is found that the dissolution rate of {delta} phases under hot deformation conditions is much faster than that under static conditions. Dislocation, vacancy and curvature play important roles in the dissolution of {delta} phases. The main nucleation mechanisms of dynamic recrystallization (DRX) for the delta-processed superalloy 718 include the bulging of original grain boundaries and the {delta} phase stimulated DRX nucleation, which is closely related to the dissolution behavior of {delta} phases under certain deformation conditions.

Primary production in the Delta: Then and now

Science.gov (United States)

Cloern, James E.; Robinson, April; Richey, Amy; Grenier, Letitia; Grossinger, Robin; Boyer, Katharyn E.; Burau, Jon; Canuel, Elizabeth A.; DeGeorge, John F.; Drexler, Judith Z.; Enright, Chris; Howe, Emily R.; Kneib, Ronald; Mueller-Solger, Anke; Naiman, Robert J.; Pinckney, James L.; Safran, Samuel M.; Schoellhamer, David H.; Simenstad, Charles A.

2016-01-01

To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850). Here we describe an approach for using these metrics of land use change to: (1) produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2) convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3) use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

Casscf/ci Calculations for First Row Transition Metal Hydrides - the TIH(4-PHI), VH(5-DELTA), CRH(6-SIGMA-PLUS), MNH(7-SIGMA-PLUS), FEH(4,6-DELTA) and NIH(2-DELTA) States

Science.gov (United States)

Walch, S. P.; Bauschlicher, C. W., Jr.

1983-04-01

Calculations are performed for the predicted ground states of TiH(4-phi), VH(5-delta), CrH(6-sigma-plus), MnH(7-sigma-plus), Fett(4,6-delta) and NiH(2-delta). For FeH both the 6-delta and 4-delta states are studied, since both are likely candidates for the ground state. The ground state symmetries are predicted based on a combination of atomic coupling arguments and coupling of 4s(2)3d(n) and 4s(1)3d(n+1) terms in the molecular system. Electron correlation is included by a CASSCF/CI (SD) treatment. The CASSCF includes near-degeneracy effects, while correlation of the 3d electrons in included at the CI level.

Tidal controls on river delta morphology

NARCIS (Netherlands)

Hoitink, A.J.F.; Wang, Z.B.; Vermeulen, B.; Huismans, Y.; Kästner, K.

2017-01-01

River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world's largest deltas intensifies. Harbour development, construction of flood defences, sand mining and

Tidal controls on river delta morphology

NARCIS (Netherlands)

Hoitink, A.J.F.; Wang, Zhengbing; Vermeulen, B.; Huismans, Y; Kästner, K

River delta degradation has been caused by extraction of natural resources, sediment retention by reservoirs, and sea-level rise. Despite global concerns about these issues, human activity in the world’s largest deltas intensifies. Harbour development, construction of flood defences, sand mining and

Environmental challenges in Nigeria's Delta Region and Agriculture ...

African Journals Online (AJOL)

The paper discussed the environmental challenges in the Niger-Delta region of Nigeria with emphasis on the impacts on agricultural production. It thus discussed the concepts of Niger-Delta, Environmental pollution, Niger-Delta crises and Agriculture. The paper posits that there are positive relationships between these ...

Paleogeographic variations of pedogenic carbonate delta13C values from Koobi Fora, Kenya: implications for floral compositions of Plio-Pleistocene hominin environments.

Science.gov (United States)

Quinn, Rhonda L; Lepre, Christopher J; Wright, James D; Feibel, Craig S

2007-11-01

Plio-Pleistocene East African grassland expansion and faunal macroevolution, including that of our own lineage, are attributed to global climate change. To further understand environmental factors of early hominin evolution, we reconstruct the paleogeographic distribution of vegetation (C(3)-C(4) pathways) by stable carbon isotope (delta(13)C) analysis of pedogenic carbonates from the Plio-Pleistocene Koobi Fora region, northeast Lake Turkana Basin, Kenya. We analyzed 202 nodules (530 measurements) from ten paleontological/archaeological collecting areas spanning environments over a 50-km(2) area. We compared results across subregions in evolving fluviolacustrine depositional environments in the Koobi Fora Formation from 2.0-1.5 Ma, a stratigraphic interval that temporally brackets grassland ascendancy in East Africa. Significant differences in delta(13)C values between subregions are explained by paleogeographic controls on floral composition and distribution. Our results indicate grassland expansion between 2.0 and 1.75 Ma, coincident with major shifts in basin-wide sedimentation and hydrology. Hypotheses may be correct in linking Plio-Pleistocene hominin evolution to environmental changes from global climate; however, based on our results, we interpret complexity from proximate forces that mitigated basin evolution. An approximately 2.5 Ma tectonic event in southern Ethiopia and northern Kenya exerted strong effects on paleography in the Turkana Basin from 2.0-1.5 Ma, contributing to the shift from a closed, lacustrine basin to one dominated by open, fluvial conditions. We propose basin transformation decreased residence time for Omo River water and expanded subaerial floodplain landscapes, ultimately leading to reduced proportions of wooded floras and the establishment of habitats suitable for grassland communities.

Impacts of Irrigation Practices on Groundwater Recharge in Mississippi Delta Using coupled SWAT-MODFLOW Model

Science.gov (United States)

Gao, F.; Feng, G.; Han, M.; Jenkins, J.; Ouyang, Y.

2017-12-01

The Lower Mississippi River alluvial plain (refers to as MS Delta), located in the northwest state of Mississippi, is one of the most productive agricultural region in the U.S. The primary crops grown in this region are soybean, corn, cotton, and rice. Approximately 80% water from the alluvial aquifer in MS Delta are withdrawn for irrigation, which makes it the most used aquifer in the State. As a result, groundwater level has declined > 6 m since 1970, which threaten the sustainability of irrigated agriculture in this region. The objectives of this study were to: 1) couple the SWAT and MODFLOW then calibrate and validate the incorporated model outputs for stream flow, groundwater level and evapotranspiration (ET) in MS Delta; 2) simulate the groundwater recharge as affected by a) conventional irrigation scheme, b) no irrigation scheme, c) ET based and soil moisture based full irrigation schedules using all groundwater, and d) ET and soil moisture based full irrigation schedule using different percentages of surface and ground water. Results indicated that the coupled model performed well during the calibration and validation for daily stream flow at three USGS gauge stations. (R2=0.7; Nash-Sutcliffe efficiency (NSE) varied from 0.6 to 0.7; Root Mean Square Error (RMSE) ranged from 20 to 27 m3/s). The values of determination coefficient R2 for groundwater level were 0.95 for calibration and 0.88 for validation, their NSE values were 0.99 and 0.93, respectively. The values of RMSE for groundwater level during the calibration and validation period were 0.51 and 0.59 m. The values of R2, NSE and RMSE between SWAT-MODFLOW simulated actual evapotranspiration (ET) and remote sensing evapotranspiration (ET) were 0.52, 0.51 and 28.1 mm. The simulated total average monthly groundwater recharge had lower values of 19 mm/month in the crop season than 30 mm/month in the crop off-growing season. The SWAT-MODFLOW can be a useful tool for not only simulating the recharge in MS

Nonperturbative calculation of symmetry breaking in quantum field theory

OpenAIRE

Bender, Carl M.; Milton, Kimball A.

1996-01-01

A new version of the delta expansion is presented, which, unlike the conventional delta expansion, can be used to do nonperturbative calculations in a self-interacting scalar quantum field theory having broken symmetry. We calculate the expectation value of the scalar field to first order in delta, where delta is a measure of the degree of nonlinearity in the interaction term.

Assessing the Value of a College Degree in Outdoor Education or Recreation: Institutional Comparisons Using the College Scorecard and Surveys of Faculty and Employers

Science.gov (United States)

Seaman, Jayson; Bell, Brent J.; Trauntvein, Nate

2017-01-01

In this article, we report on research undertaken in 2016 to assess a number of trends influencing the current status of degree-granting outdoor programs in the United States, including factors that bear on the value of degrees. We analyze data provided by the U.S. Department of Education's College Scorecard and results of a survey comparing 59…

Decontamination of cesium, strontium, and cobalt from aqueous solutions by bentonite

Energy Technology Data Exchange (ETDEWEB)

Khan, M.A. [Univ. of the Punjab, Lahore (Pakistan); Khan, S.A. [Government F.C. College, Lahore (Pakistan)

1996-12-31

Sorption studies of cesium, strontium, and cobalt (Cs, Sr, and Co) on bentonite under various experimental conditions, such as contact time, pH, sorbent and sorbate concentration, and temperature, have been performed. The sorption data for all these metals have been interpreted in terms of Freundlich, Langmuir, and Dubinin-Radushkevich equations. Thermodynamics parameters, such as heat of sorption {Delta}H{degrees}, free energy change {Delta}G{degrees}, and entropy change {Delta}S{degrees}, for the sorption of these metals on bentonite have been calculated. The value of {Delta}H{degrees} shows that the sorption of Cs was exothermic, while the sorption of Sr and Co on bentonite were endothermic in nature. The value of {Delta}G{degrees} for their sorption was negative, showing the spontaneity of the process. The maximum loading capacity of Cs, Sr, and Co were 75.5, 22, and 27.5 meq, respectively, for 100 g of bentonite. The mean free energy E of Cs, Sr, and Co sorption on bentonite was 14.5, 9, and 7.7 kJ/mol, respectively. The value of E indicates that ion exchange may be the predominant mode of sorption for these radionuclides. The desorption studies with 0.01 M CaCl{sub 2} and groundwater at low-metal loading on bentonite showed that about 95% of Cs, 85-90% of Sr, and 97% of Co were irreversibly sorbed. Bentonite could be effectively used for the decontamination of wastewater effluent containing low concentrations of radioactive nuclides of Cs, Sr, and Co. 16 refs., 7 figs., 3 tabs.

An Examination of How Academic Advancement of U.S. Journalism Students Relates to Their Degree Motivations, Values, and Technology Use

Science.gov (United States)

Carpenter, Serena; Hoag, Anne; Grant, August E.; Bowe, Brian J.

2015-01-01

The newsroom is a powerful influence in a journalist's identity formation. Research has yet to verify the socializing impact of academia. This research utilized the quantitative survey method applying it to undergraduate journalism students (n = 798) to assess how academic status relates to students' degree motivations, life values, and technology…

Displacement waves in La2CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta)

Science.gov (United States)

Kajitani, Tsuyoshi; Onozuka, Takashi; Yamaguchi, Yasuo; Hirabayashi, Makoto; Syono, Yasuhiko

1987-11-01

Structural investigation of orthorhombic La2CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta) was carried out by means of X-ray and neutron diffraction on the basis of the space group Cmmm. The periodic expansion/contraction type distortion of CuO6 octahedra was found in both orthorhombic compounds. The distortion is nearly one-dimensional in La2CuO(4-delta) but is two-dimensional in La(1.85)Sr(0.15)CuO(4-delta). The existence of a charge-density wave is highly possible in the structures.

First-principles elastic constants and phonons of delta-Pu

DEFF Research Database (Denmark)

Söderlind, P.; Landa, A.; Sadigh, B.

2004-01-01

Elastic constants and zone-boundary phonons of delta-plutonium have been calculated within the density-functional theory. The paramagnetic state of delta-Pu is modeled by disordered magnetism utilizing either the disordered local moment or the special quasirandom structure techniques. The anomalo......Elastic constants and zone-boundary phonons of delta-plutonium have been calculated within the density-functional theory. The paramagnetic state of delta-Pu is modeled by disordered magnetism utilizing either the disordered local moment or the special quasirandom structure techniques....... The anomalously soft C-' as well as a large anisotropy ratio (C-44/C-') of delta-Pu is reproduced by this theoretical model. Also the recently measured phonons for delta-Pu compare relatively well with their theoretical counterpart at the zone boundaries....

VALUASI TOTAL EKONOMI HUTAN MANGROVE DI KAWASAN DELTA MAHAKAM KABUPATEN KUTAI KARTANEGARA KALIMANTAN TIMUR

Directory of Open Access Journals (Sweden)

Yuyun Wahyuni

2014-04-01

Full Text Available Mangrove forest is a tropical coastal vegetation community. The purpose of this study are: to identify the types and functions of the ecosystem of the area of mangrove forest; calculate the total economic value generated by mangrove forests; examine the factors that affect the economic benefits gained at the Mahakam Delta mangrove forest, Kutai regency. Results of this study indicated that there were four dominant types of forests mangrove: rizhopora, avicennia, sonneratia and nypa. They have decreased due to reduced function of mangrove forest area. This result is supported by the calculation of total economic value (TEV in 2012 which amounted to Rp503.071.398 869,2. Factor affecting the economic benefits of mangrove forests in order to remain sustainable in recreational value of travel cost, student employment, the number of dependent and age, while the factors that affect the existence of the mangrove forest are job and income, while the factor that affect the sustainability endemic bekantan are of the income, origin in the region and outside the region.Keywords: Mahakam delta, mangrove forest, TEV

Assessment of Heavy Metal Pollution and Health Risks in the Soil-Plant-Human System in the Yangtze River Delta, China

Science.gov (United States)

Hu, Bifeng; Jia, Xiaolin; Hu, Jie; Xu, Dongyun; Xia, Fang; Li, Yan

2017-01-01

Heavy metal (HM) contamination and accumulation is a serious problem around the world due to the toxicity, abundant sources, non-biodegradable properties, and accumulative behaviour of HMs. The degree of soil HM contamination in China, especially in the Yangtze River Delta, is prominent. In this study, 1822 pairs of soil and crop samples at corresponding locations were collected from the southern Yangtze River Delta of China, and the contents of Ni, Cr, Zn, Cd, As, Cu, Hg, and Pb were measured. The single pollution index in soil (SPI) and Nemerow composite pollution index (NCPI) were used to assess the degree of HM pollution in soil, and the crop pollution index (CPI) was used to explore the degree of HM accumulation in crops. The bioaccumulation factor (BAF) was used to investigate the translocation of heavy metals in the soil-crop system. The health risks caused by HMs were calculated based on the model released by the U.S. Environmental Protection Agency. The SPIs of all elements were at the unpolluted level. The mean NCPI was at the alert level. The mean CPIs were in the following decreasing order: Ni (1.007) > Cr (0.483) > Zn (0.335) > Cd (0.314) > As (0.232) > Cu (0.187) > Hg (0.118) > Pb (0.105). Only the mean content of Ni in the crops exceeded the national standard value. The standard exceeding rates were used to represent the percentage of samples whose heavy metal content is higher than the corresponding national standard values. The standard exceeding rates of Cu, Hg, and Cd in soil were significantly higher than corresponding values in crops. Meanwhile, the standard exceeding rates of Ni, As, and Cr in crops were significantly higher than corresponding values in soil. The chronic daily intake (CDI) of children (13.8 × 10−3) was the largest among three age groups, followed by adults (6.998 × 10−4) and seniors (5.488 × 10−4). The bioaccumulation factors (BAFs) of all crops followed the order Cd (0.249) > Zn (0.133) > As (0.076) > Cu (0.064) > Ni

Assessment of Heavy Metal Pollution and Health Risks in the Soil-Plant-Human System in the Yangtze River Delta, China.

Science.gov (United States)

Hu, Bifeng; Jia, Xiaolin; Hu, Jie; Xu, Dongyun; Xia, Fang; Li, Yan

2017-09-10

Heavy metal (HM) contamination and accumulation is a serious problem around the world due to the toxicity, abundant sources, non-biodegradable properties, and accumulative behaviour of HMs. The degree of soil HM contamination in China, especially in the Yangtze River Delta, is prominent. In this study, 1822 pairs of soil and crop samples at corresponding locations were collected from the southern Yangtze River Delta of China, and the contents of Ni, Cr, Zn, Cd, As, Cu, Hg, and Pb were measured. The single pollution index in soil (SPI) and Nemerow composite pollution index (NCPI) were used to assess the degree of HM pollution in soil, and the crop pollution index (CPI) was used to explore the degree of HM accumulation in crops. The bioaccumulation factor (BAF) was used to investigate the translocation of heavy metals in the soil-crop system. The health risks caused by HMs were calculated based on the model released by the U.S. Environmental Protection Agency. The SPIs of all elements were at the unpolluted level. The mean NCPI was at the alert level. The mean CPIs were in the following decreasing order: Ni (1.007) > Cr (0.483) > Zn (0.335) > Cd (0.314) > As (0.232) > Cu (0.187) > Hg (0.118) > Pb (0.105). Only the mean content of Ni in the crops exceeded the national standard value. The standard exceeding rates were used to represent the percentage of samples whose heavy metal content is higher than the corresponding national standard values. The standard exceeding rates of Cu, Hg, and Cd in soil were significantly higher than corresponding values in crops. Meanwhile, the standard exceeding rates of Ni, As, and Cr in crops were significantly higher than corresponding values in soil. The chronic daily intake (CDI) of children (13.8 × 10 -3 ) was the largest among three age groups, followed by adults (6.998 × 10 -4 ) and seniors (5.488 × 10 -4 ). The bioaccumulation factors (BAFs) of all crops followed the order Cd (0.249) > Zn (0.133) > As (0.076) > Cu (0.064) > Ni

The MACHO Project Sample of Galactic Bulge High-Amplitude {delta} Scuti Stars: Pulsation Behavior and Stellar Properties

Energy Technology Data Exchange (ETDEWEB)

Alcock, C.; Allsman, R. A.; Alves, D. R.; Axelrod, T. S.; Becker, A. C.; Bennett, D. P.; Cook, K. H.; Freeman, K. C.; Geha, M.; Griest, K. (and others)

2000-06-20

We have detected 90 objects with periods and light-curve structures similar to those of field {delta} Scuti stars using the Massive Compact Halo Object (MACHO) Project database of Galactic bulge photometry. If we assume similar extinction values for all candidates and absolute magnitudes similar to those of other field high-amplitude {delta} Scuti stars (HADS), the majority of these objects lie in or near the Galactic bulge. At least two of these objects are likely foreground {delta} Scuti stars, one of which may be an evolved nonradial pulsator, similar to other evolved, disk-population {delta} Scuti stars. We have analyzed the light curves of these objects and find that they are similar to the light curves of field {delta} Scuti stars and the {delta} Scuti stars found by the Optical Gravitational Lens Experiment (OGLE). However, the amplitude distribution of these sources lies between those of low- and high-amplitude {delta} Scuti stars, which suggests that they may be an intermediate population. We have found nine double-mode HADS with frequency ratios ranging from 0.75 to 0.79, four probable double- and multiple-mode objects, and another four objects with marginal detections of secondary modes. The low frequencies (5-14 cycles day-1) and the observed period ratios of {approx}0.77 suggest that the majority of these objects are evolved stars pulsating in fundamental or first overtone radial modes. (c) 2000 The American Astronomical Society.

Stimulation of accumbal GABAA receptors inhibits delta2-, but not delta1-, opioid receptor-mediated dopamine efflux in the nucleus accumbens of freely moving rats.

Science.gov (United States)

Aono, Yuri; Kiguchi, Yuri; Watanabe, Yuriko; Waddington, John L; Saigusa, Tadashi

2017-11-15

The nucleus accumbens contains delta-opioid receptors that may reduce inhibitory neurotransmission. Reduction in GABA A receptor-mediated inhibition of accumbal dopamine release due to delta-opioid receptor activation should be suppressed by stimulating accumbal GABA A receptors. As delta-opioid receptors are divided into delta2- and delta1-opioid receptors, we analysed the effects of the GABA A receptor agonist muscimol on delta2- and delta1-opioid receptor-mediated accumbal dopamine efflux in freely moving rats using in vivo microdialysis. Drugs were administered intracerebrally through the dialysis probe. Doses of compounds indicate total amount administered (mol) during 25-50min infusions. The delta2-opioid receptor agonist deltorphin II (25.0nmol)- and delta1-opioid receptor agonist DPDPE (5.0nmol)-induced increases in dopamine efflux were inhibited by the delta2-opioid receptor antagonist naltriben (1.5nmol) and the delta1-opioid receptor antagonist BNTX (150.0pmol), respectively. Muscimol (250.0pmol) inhibited deltorphin II (25.0nmol)-induced dopamine efflux. The GABA A receptor antagonist bicuculline (50.0pmol), which failed to affect deltorphin II (25.0nmol)-induced dopamine efflux, counteracted the inhibitory effect of muscimol on deltorphin II-induced dopamine efflux. Neither muscimol (250.0pmol) nor bicuculline (50.0 and 500.0pmol) altered DPDPE (5.0nmol)-induced dopamine efflux. The present results show that reduction in accumbal GABA A receptor-mediated inhibition of dopaminergic activity is necessary to produce delta2-opioid receptor-induced increase in accumbal dopamine efflux. This study indicates that activation of delta2- but not delta1-opioid receptors on the cell bodies and/or terminals of accumbal GABAergic interneurons inhibits GABA release and, accordingly, decreases GABA A receptor-mediated inhibition of dopaminergic terminals, resulting in enhanced accumbal dopamine efflux. Copyright © 2017 Elsevier B.V. All rights reserved.

Dirac delta representation by exact parametric equations.. Application to impulsive vibration systems

Science.gov (United States)

Chicurel-Uziel, Enrique

2007-08-01

A pair of closed parametric equations are proposed to represent the Heaviside unit step function. Differentiating the step equations results in two additional parametric equations, that are also hereby proposed, to represent the Dirac delta function. These equations are expressed in algebraic terms and are handled by means of elementary algebra and elementary calculus. The proposed delta representation complies exactly with the values of the definition. It complies also with the sifting property and the requisite unit area and its Laplace transform coincides with the most general form given in the tables. Furthermore, it leads to a very simple method of solution of impulsive vibrating systems either linear or belonging to a large class of nonlinear problems. Two example solutions are presented.

Tidal modulated flow and sediment flux through Wax Lake Delta distributary channels: Implications for delta development

Directory of Open Access Journals (Sweden)

K. Hanegan

2015-03-01

Full Text Available In this study, a Delft3D model of the Wax Lake Delta was developed to simulate flow and sediment flux through delta distributary channels. The model was calibrated for tidal constituents as well as velocity and sediment concentration across channel transects. The calibrated model was then used to simulate full spring–neap tidal cycles under constant low flow upstream boundary conditions, with grain size variation in suspended load represented using two sediment fractions. Flow and sediment flux results through distributary channel cross-sections were examined for spatial and temporal variability with the goal of characterizing the role of tides in sediment reworking and delta development. The Wax Lake Delta has prograded through channel extension, river mouth bar deposition, and channel bifurcation. Here we show that tidal modulation of currents influences suspended sand transport, and spatial acceleration through distributary channels at low tides is sufficient to suspend sand in distal reaches during lower flows. The basinward-increasing transport capacity in distributary channels indicates that erosive channel extension could be an important process, even during non-flood events.

Delta Vegetation and Land Use [ds292

Data.gov (United States)

California Natural Resource Agency — Vegetation and land use are mapped for the approximately 725,000 acres constituting the Legal Delta portion of the Sacramento and San Joaquin River Delta area....

Primary Production in the Delta: Then and Now

Directory of Open Access Journals (Sweden)

James E. Cloern

2016-10-01

Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss3art1To evaluate the role of restoration in the recovery of the Delta ecosystem, we need to have clear targets and performance measures that directly assess ecosystem function. Primary production is a crucial ecosystem process, which directly limits the quality and quantity of food available for secondary consumers such as invertebrates and fish. The Delta has a low rate of primary production, but it is unclear whether this was always the case. Recent analyses from the Historical Ecology Team and Delta Landscapes Project provide quantitative comparisons of the areal extent of 14 habitat types in the modern Delta versus the historical Delta (pre-1850. Here we describe an approach for using these metrics of land use change to: (1 produce the first quantitative estimates of how Delta primary production and the relative contributions from five different producer groups have been altered by large-scale drainage and conversion to agriculture; (2 convert these production estimates into a common currency so the contributions of each producer group reflect their food quality and efficiency of transfer to consumers; and (3 use simple models to discover how tidal exchange between marshes and open water influences primary production and its consumption. Application of this approach could inform Delta management in two ways. First, it would provide a quantitative estimate of how large-scale conversion to agriculture has altered the Delta's capacity to produce food for native biota. Second, it would provide restoration practitioners with a new approach—based on ecosystem function—to evaluate the success of restoration projects and gauge the trajectory of ecological recovery in the Delta region.

Tensor force and delta excitation for the structure of light nuclei

International Nuclear Information System (INIS)

Horii, K; Myo, T; Toki, H

2014-01-01

We treat explicitly Δ(1232) isobar degrees of freedom using a bare nucleon-nucleon interaction for few-body systems, where Δ excitations can be the origin of the three-body force via the pion exchange. We adopt the Argonne two-body potential including Δ, named as AV28 potential, and study the role of Δ explicitly in two-body and three-body systems. It was found that the additional Δ states generate strong tensor correlations caused by the transitions between N and Δ states, and change tensor matrix elements largely from the results with only nucleons. We studied the effects of three-body force in the triton and obtained 0.8 MeV attraction due to the intermediate Δ excitation. Due to the lack of the total binding energy for the triton in the delta model, we further studied carefully the effects of the delta excitation in various two body channels and compared with the nucleon only model in the AV14 potential. We modified slightly the AV28 potential in the singlet S channel so that we could reproduce the triton binding energy due to the appropriate amount of the three-body force effects

Seasonal inter-relationships in atmospheric methane and companion delta13C values: effects of sinks and sources

Energy Technology Data Exchange (ETDEWEB)

Lassey, K. R.; Mikaloff Fletcher, S. E. (NIWA, Wellington (New Zealand)), e-mail: k.lassey@niwa.co.nz; Allan, W. (Allan Planning and Research Ltd., Petone (New Zealand))

2011-07-15

Recent developments in applying carbon-isotope information to better understand regional and global methane budgets infer a strong role by a highly fractionating seasonal sink such as atomic chlorine. Specifically, OH as the predominant seasonal sink cannot account for the 'phase ellipses' based on observed seasonal cycles of methane mixing ratio and isotope ratio, delta13C. Although a strong role by atomic chlorine is inferred empirically, open questions remain about the interplay between sources and sinks in determining the properties of phase ellipses. This paper employs a simple didactic model of the seasonal cycling of atmospheric methane to understand such interplay. We demonstrate that a single seasonal sink and seasonal source act together to imprint anti-phase seasonalities on atmospheric methane and delta13C, which lead to phase ellipses that collapse onto a straight line with slope characteristic of that sink. This explains empirical findings of these anti-phase relationships in three-dimensional modelling studies. We also demonstrate that multiple seasonal sinks acting with a seasonal source can yield surprising properties for the phase ellipse that not only explain some features of phase ellipses reported in modelling studies but also have the potential to explain marked inter-annual variation in phase ellipses based on observation

The Inconvenient Truth of Fresh Sediment: Insights from a New Method for Quantifying Subsidence in the Mississippi Delta

Science.gov (United States)

Chamberlain, E. L.; Shen, Z.; Tornqvist, T. E.; Kim, W.

2017-12-01

Knowing the rates and drivers of subsidence in deltas is essential to coastal management. There is a growing consensus that relatively shallow processes such as compaction and artificial drainage are primary contributors to subsidence, although deeper processes such as faulting may be locally important. Here we present a new method to quantify subsidence of a 6000 km2 relict bayhead delta of the Mississippi Delta, using the depth of the mouthbar-overbank stratigraphic boundary that formed near the low tide level in combination with OSL chronology. The contributions of isostatic processes are removed by subtracting a relative sea-level rise term previously obtained from basal peat. We find that displacement rates of the boundary, averaged over 750 to 1500 years, are on the order of a few mm/yr. Cumulative displacement is strongly correlated to overburden thickness, decreases coastward coincident with thinning of the bayhead delta deposit, and appears unrelated to the thickness of underlying Holocene strata or the occurrence of previously mapped faults. This supports compaction of shallow strata as a dominant driver of subsidence in the Mississippi Delta. We find that at least 50% of elevation gained through overbank deposition is ultimately lost to subsidence, significantly greater than the 35% loss previously estimated for inland localities underlain by peat. Our results demonstrate that bayhead deltas are especially vulnerable to subsidence. This finding has major relevance to coastal restoration in the Mississippi Delta through engineered river-sediment diversions. While inactive regions of the delta may be fairly stable if not perturbed by humans, the introduction of fresh sediment to the delta plain will inevitably accelerate subsidence. Values obtained with our method will be applied to a delta growth model that predicts the land-building potential of river-sediment diversions discharging into open bays under realistic scenarios of load-driven subsidence.

Pulse radiolysis study of supercritical water-G-value measurement up to 450 degree C

International Nuclear Information System (INIS)

Katsumura, Y.

2006-01-01

It is widely recognized that the understanding of water radiolysis at elevated temperatures is inevitably important in the field of water chemistry in light water reactors because water radiolysis is closely related to many subjects such as hydrogen water chemistry (H 2 injection), SCC (stress corrosion cracking), dose accumulation and so on. This situation would also be applied to the future reactor using supercritical water (>374 C, 22.1MPa) as a coolant, so called supercritical water-cooled reactor (SCWR). Therefore, it is important to investigate water radiolysis of supercritical water. In 1989 Prof. Oka, University of Tokyo, proposed the SCWR as a future reactor and done much design study. This reactor has many advantages such as high energy efficiency, applicability of experience accumulated in light water reactors and supercritical fissile plant, and compact structure. In 2002 the Department of Energy in USA has selected the SCWR as one of the six Generation IV reactors and fundamental research has started in different countries as a national or an international project. In the present research G-values of water radiolysis have been measured by using a pulse radiolysis method up to 450 degree C to obtain the fundamental data relevant to the development of the SCWR. In supercritical water, the pressure controls the density of water easily and it was found that the G-values are strongly dependent not only on temperature but also on density in supercritical water. After presentation of experimental method and its difficulties, temperature and density dependent G-values of water decomposition products in supercritical water would be summarized. (authors)

Detritus fuels ecosystem metabolism but not metazoan food webs in San Francisco estuary's freshwater delta

Science.gov (United States)

Sobczak, W.V.; Cloern, J.E.; Jassby, A.D.; Cole, B.E.; Schraga, T.S.; Arnsberg, A.

2005-01-01

Detritus from terrestrial ecosystems is the major source of organic matter in many streams, rivers, and estuaries, yet the role of detritus in supporting pelagic food webs is debated. We examined the importance of detritus to secondary productivity in the Sacramento and San Joaquin River Delta (California, United States), a large complex of tidal freshwater habitats. The Delta ecosystem has low primary productivity but large detrital inputs, so we hypothesized that detritus is the primary energy source fueling production in pelagic food webs. We assessed the sources, quantity, composition, and bioavailability of organic matter among a diversity of habitats (e.g., marsh sloughs, floodplains, tidal lakes, and deep river channels) over two years to test this hypothesis. Our results support the emerging principle that detritus dominates riverine and estuarine organic matter supply and supports the majority of ecosystem metabolism. Yet in contrast to prevailing ideas, we found that detritus was weakly coupled to the Delta's pelagic food web. Results from independent approaches showed that phytoplankton production was the dominant source of organic matter for the Delta's pelagic food web, even though primary production accounts for a small fraction of the Delta's organic matter supply. If these results are general, they suggest that the value of organic matter to higher trophic levels, including species targeted by programs of ecosystem restoration, is a function of phytoplankton production. ?? 2005 Estuarine Research Federation.

The harmoniation of cultural heritage and architectural conseration needs with socio-economic requirements of rural habitat in Danube Delta

Directory of Open Access Journals (Sweden)

SELA Florentina

2016-12-01

Full Text Available The paper present a study of cultural heritage of rural landscape in Danube Delta Biosphere Reserve focuses on cultural landscapes that reflect traditional lifestyle of the locals, activities of deltas’ resource sustainable exploitation, creating visual elements in the rural landscape, especially on traditional buildings, fishermens’ temporary shelters from fishing areas and other traditional activities. In order to highlight the necessity of cultural heritage harmonization and architectural conservation with the socio-economic requirements of rural habitat in Danube Delta were made some field activities through different methods of field investigation, like structured and semistructured interviews, questionnaires, focus groups. In Danube Delta villages, the changes imposed by the touristic function of most of existing or new construction have produced important changes in the architectural landscape of existing settlements impending danger of destroying traditional architectural values which demonstrates on the one hand the personality and inovation spirit of local people in their constructions, particularly in the use of local materials, and on the other hand gives a specific area feature that blends perfectly with the natural landscape. Danube Delta, the space of complex features in terms of cultural values, characterized as open gate of cultural interference, is the area that can provide options to balance cohabitation and cultural heritage.

Displacement waves in La/sub 2/CuO(4-delta) and La(1. 85)Sr(0. 15)CuO(4-delta)

Energy Technology Data Exchange (ETDEWEB)

Kajitani, T.; Onozuka, T.; Yamaguchi, Y.; Hirabayashi, M.; Syono, Y.

1987-11-01

Structural investigation of orthorhombic La/sub 2/CuO(4-delta) and La(1.85)Sr(0.15)CuO(4-delta) was carried out by means of X-ray and neutron diffraction on the basis of the space group Cmmm. The periodic expansion/contraction type distortion of CuO6 octahedra was found in both orthorhombic compounds. The distortion is nearly one-dimensional in La/sub 2/CuO(4-delta) but is two-dimensional in La(1.85)Sr(0.15)CuO(4-delta). The existence of a charge-density wave is highly possible in the structures. 20 references.

How yield relates to ash content, Delta 13C and Delta 18O in maize grown under different water regimes.

Science.gov (United States)

Cabrera-Bosquet, Llorenç; Sánchez, Ciro; Araus, José Luis

2009-11-01

Stable isotopes have proved a valuable phenotyping tool when breeding for yield potential and drought adaptation; however, the cost and technical skills involved in isotope analysis limit its large-scale application in breeding programmes. This is particularly so for Delta(18)O despite the potential relevance of this trait in C(4) crops. The accumulation of minerals (measured as ash content) has been proposed as an inexpensive way to evaluate drought adaptation and yield in C(3) cereals, but little is known of the usefulness of this measure in C(4) cereals such as maize (Zea mays). The present study investigates how yield relates to ash content, Delta(13)C and Delta(18)O, and evaluates the use of ash content as an alternative or complementary criterion to stable isotopes in assessing yield potential and drought resistance in maize. A set of tropical maize hybrids developed by CIMMYT were subjected to different water availabilities, in order to induce water stress during the reproductive stages under field conditions. Ash content and Delta(13)C were determined in leaves and kernels. In addition, Delta(18)O was measured in kernels. Water regime significantly affected yield, ash content and stable isotopes. The results revealed a close relationship between ash content in leaves and the traits informing about plant water status. Ash content in kernels appeared to reflect differences in sink-source balance. Genotypic variation in grain yield was mainly explained by the combination of ash content and Delta(18)O, whilst Delta(13)C did not explain a significant percentage of such variation. Ash content in leaves and kernels proved a useful alternative or complementary criterion to Delta(18)O in kernels for assessing yield performance in maize grown under drought conditions.

Tenth value layers for 60Co gamma rays and for 4, 6, 10, 15, and 18 MV x rays in concrete for beams of cone angles between 0 degrees and 14 degrees calculated by Monte Carlo simulation.

Science.gov (United States)

Jaradat, Adnan K; Biggs, Peter J

2007-05-01

The calculation of shielding barrier thicknesses for radiation therapy facilities according to the NCRP formalism is based on the use of broad beams (that is, the maximum possible field sizes). However, in practice, treatment fields used in radiation therapy are, on average, less than half the maximum size. Indeed, many contemporary treatment techniques call for reduced field sizes to reduce co-morbidity and the risk of second cancers. Therefore, published tenth value layers (TVLs) for shielding materials do not apply to these very small fields. There is, hence, a need to determine the TVLs for various beam modalities as a function of field size. The attenuation of (60)Co gamma rays and photons of 4, 6, 10, 15, and 18 MV bremsstrahlung x ray beams by concrete has been studied using the Monte Carlo technique (MCNP version 4C2) for beams of half-opening angles of 0 degrees , 3 degrees , 6 degrees , 9 degrees , 12 degrees , and 14 degrees . The distance between the x-ray source and the distal surface of the shielding wall was fixed at 600 cm, a distance that is typical for modern radiation therapy rooms. The maximum concrete thickness varied between 76.5 cm and 151.5 cm for (60)Co and 18 MV x rays, respectively. Detectors were placed at 630 cm, 700 cm, and 800 cm from the source. TVLs have been determined down to the third TVL. Energy spectra for 4, 6, 10, 15, and 18 MV x rays for 10 x 10 cm(2) and 40 x 40 cm(2) field sizes were used to generate depth dose curves in water that were compared with experimentally measured values.

Climatology of the Eastern Arabian Sea during the last glacial cycle reconstructed from paired measurement of foraminiferal delta sup(18)O and Mg/Ca

Digital Repository Service at National Institute of Oceanography (India)

Banakar, V.K.; Mahesh, B.S.; Burr, G.; Chodankar, A

Paired measurements of Mg/Ca and delta sup(18)O of Globigerenoides sacculifer from an Eastern Arabian Sea (EAS) sediment core indicate that sea-surface temperature (SST) varied within 2 degrees C and sea-surface salinity within 2 psu during the last...

Hydrological and Climatic Significance of Martian Deltas

Science.gov (United States)

Di Achille, G.; Vaz, D. A.

2017-10-01

We a) review the geomorphology, sedimentology, and mineralogy of the martian deltas record and b) present the results of a quantitative study of the hydrology and sedimentology of martian deltas using modified version of terrestrial model Sedflux.

Abraham Reef Stable Isotope Data (delta 13C, delta 18O, delta 14C) for 1635-1957

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Site: Abraham Reef, 22ó 06'S, 153ó 00'E, Porites australiensus, Radiocarbon (delta 14C) and Stable Isotope (del 18O and del 13C) results from bi-annual samples from...

Delta Plaza kohvik = The Delta Plaza Café / Margit Mutso

Index Scriptorium Estoniae

Mutso, Margit, 1966-

2010-01-01

Tallinnas Pärnu mnt. 141 asuva kohviku Delta Plaza sisekujundusest. Sisearhitektid Tiiu Truus ja Marja Viltrop (Stuudio Truus OÜ). Hoone arhitektid Jüri Okas ja Marika Lõoke (AB J. Okas & M. Lõoke). Žürii liikme Mait Summataveti arvamus kohvikust

Studying medium effects with the optimized {delta} expansion

Energy Technology Data Exchange (ETDEWEB)

Krein, G [Instituto de Fisica Teorica (IFT), Sao Paulo, SP (Brazil); Menezes, D P [Santa Catarina Univ., Florianopolis, SC (Brazil). Dept. de Fisica; Nielsen, M [Sao Paulo Univ., SP (Brazil). Inst. de Fisica; Pinto, M B [Montpellier-2 Univ., 34 (France). Lab. de Physique Mathematique

1995-04-01

The possibility of using the optimized {delta} expansion for studying medium effects on hadronic properties in quark or nuclear matter is investigated. The {delta} expansion is employed to study density effects with two commonly used models in hadron and nuclear physics, the Nambu-Jona-Lasinio model for the dynamical chiral symmetry breaking and the Walecka model for the equation of state of nuclear matter. The results obtained with the {delta} expansion are compared to those obtained with the traditional Hartree-Fock approximation. Perspectives for using the {delta} expansion in other field theoretic models in hadron and nuclear physics are discussed. (author). 17 refs, 9 figs.

Oil, migration, and the political economy of HIV/AIDS prevention in Nigeria's Niger Delta.

Science.gov (United States)

Udoh, Isidore A

2013-01-01

In most of sub-Saharan Africa, HIV/AIDS is driven by endemic structural problems such as unemployment, poverty, forced migration, sexual exploitation, and concurrent sexual partnerships. In the Niger Delta of Nigeria, the epidemic is exacerbated by recurring regional conflict and negative environmental externalities resulting from 50 years of oil exploration. This article seeks to identify and analyze potential barriers to HIV/AIDS prevention and treatment from oil pollution and other environmental stressors in Nigeria's Niger Delta. We develop a conceptual framework to understand how oil politics and economic systems affect HIV risks in Nigeria. We then evaluate evidence of how environmental exposures can amplify risks. Using 10 semi-structured interviews, with 85 focus group participants, we test the argument that HIV transmission in the Niger Delta is related to a manipulative "divide and rule" power dynamic that characterizes multinational oil companies' role in shaping conflict contours in oil communities. Oil exploration destroys livelihoods, institutions, and values and forces impoverished and illiterate girls and women to migrate or be trafficked to urban centers as child laborers and sex workers. The elevated HIV/AIDS risk in the Niger Delta brings into focus the political economy of resource extraction, globalization, and indigenous, minority rights and struggles.

Delta electron spectroscopy for the study of the inner-shell excitation in heavy ion collisions

International Nuclear Information System (INIS)

Trollmann, G.

1981-01-01

In this thesis energy and angular differential cross sections of delta electrons from ion-atom collisions are measured and compared with different perturbation theories. Shell specific cross sections were obtained from electron-X-ray coincidences. Contradicting theoretical statements concerning the angular distribution of the electrons can be experimentally clarified, other predictions are verified. Starting from fast, strongly asymmetric collisions until to slow, more symmetric collisions the question of the disturbance of the stationary target state by the projectile and the formation of intermediate molecular state is studied. With the results of the measurement of the delta electrons it can be contributed to the clarification of the question for the physical origin of the continuous X-radiation in the energy range beyond the K-line of the heavier collision partner. It is shown that the secondary electron bremsstrahlung discussed as radiation source besides the molecular orbital (MO) radiation is in its intensity about more than one order of magnitude weaker than the measured X-radiation and is therefore excluded as dominant radiation. In the framework of this work an apparature was developed, which allows the electron spectroscopy in the energy range between 10 keV and 150 keV and the angular range between 5 degrees and 180 degrees for the absolute determination of double differential cross sections. (orig./HSI) [de

Assessment and potential sources of metals in the surface sediments of the Yellow River Delta, Eastern China.

Science.gov (United States)

Cheng, Qingli; Lou, Guangyan; Huang, Wenhai; Li, Xudong

2017-07-01

The Yellow River Delta is the most intact estuary wetland in China and suffers from great pressure of metals. Seventy-seven surface sediment samples were collected in the delta, and contents of Cu, Pb, Cd, Cr, Zn, Ni, and Mn were analyzed by inductively coupled plasma spectrometry and those of Hg and As by atomic fluorescence spectrometry. The results showed that means of metal contents (ppm, dry weight) were as follows: Hg, 0.04; Cr, 61.72; Cu, 20.97; Zn, 60.73; As, 9.47; Pb, 21.91; Cd, 0.12; Ni, 27.24; and Mn, 540.48. 43.8% of Hg and 14.3% of Cd were from the allogenic source while others from the authigenic source. The results of the geoaccumulation indexes appeared that 6.5% of sites from the estuarine and the Gudao areas were moderately polluted by Hg. All ecological risk index values of Hg and 37.7% of Cd were more than 40, which were the main factors of strongly and moderately potential ecological risks of 37.7% of sites in the delta. High Cd contents may be due to the alkaline conditions of the delta and the unreasonable management of the farmland, while the abnormal distribution of Hg to the wet or dry deposition and the erosion of the seawater. It was suggested to monitor Hg content in the atmosphere of the Yellow River Delta. The results were expected to update the pollution status of metals in the delta and created awareness of preserving the sound condition of the Yellow River Delta.

Bio-geochemical studies of indus delta mangrove ecosystem through heavy metal assessment

International Nuclear Information System (INIS)

Ismail, S.; Saifullah, S.M.

2014-01-01

In the present study monitoring of heavy metal pollution was done in the mangrove habitats of Indus Delta. Different levels of four heavy metal (Pb, Cu, Cd, and Zn) in abiotic component (sediments and water) and biotic components (mangrove plants parts like, (Pneumatophores, bark, leaves, flowers, and fruits) were determined. The highest average concentration of heavy metals (111 ppm Zn, 60.0 ppm Pb, 52.2 ppm Cu, 1.43 ppm Cd) were measured in sediments and the lowest in the water (0.13 ppm Zn, 0.0014 ppm Cu, 0.0007 ppm Pb , 0.00061 ppm Cd). Among the four heavy metals, Zn was the most abundant metal in all components of the ecosystem, followed by Cu, Pb, and Cd (Zn>Cu>Pb>Cd), and hence A. marina can be proposed as a hyper-accumulator for Zn, which opens doors for further research. The pollution load index (PLI) had values higher than 1 and varied between 2.02-1.70 at Indus Delta, whereas at MianiHor the PLI was 0.65, which indicated that Indus Delta mangrove Ecosystem was under threat of pollution under the present scenario. (author)

LIVER TRANSPLANTATION IN HEPATITIS DELTA: SOUTH AMERICA EXPERIENCE

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Daniel Souza LIMA

Full Text Available ABSTRACT BACKGROUND: The Amazon region is one of the main endemic areas of hepatitis delta in the world and the only one related to the presence of genotype 3 of the delta virus. OBJECTIVE: To analyze the profile, mortality and survival of cirrhotic patients submitted to liver transplantation for chronic hepatitis delta virus and compare with those transplanted by hepatitis B virus monoinfection. METHODS: Retrospective, observational and descriptive study. From May 2002 to December 2011, 629 liver transplants were performed at the Walter Cantídio University Hospital, of which 29 patients were transplanted due to cirrhosis caused by chronic delta virus infection and 40 by hepatitis B chronic monoinfection. The variables analyzed were: age, sex, MELD score, Child-Pugh score, upper gastrointestinal bleeding and hepatocellular carcinoma occurrence before the transplantation, perioperative platelet count, mortality and survival. RESULTS: The Delta Group was younger and all came from the Brazilian Amazon Region. Group B presented a higher proportion of male patients (92.5% compared to Group D (58.6%. The occurrence of upper gastrointestinal bleeding before transplantation, MELD score, and Child-Pugh score did not show statistical differences between groups. The occurrence of hepatocellular carcinoma and mortality were higher in the hepatitis B Group. The survival in 4 years was 95% in the Delta Group and 75% in the B Group, with a statistically significant difference (P=0.034. Patients with hepatitis delta presented more evident thrombocytopenia in the pre-transplantation and in the immediate postoperative period. CONCLUSION: The hepatitis by delta virus patients who underwent liver transplantation were predominantly male, coming from the Brazilian Amazon region and with similar liver function to the hepatitis B virus patients. They had a lower incidence of hepatocellular carcinoma, more marked perioperative thrombocytopenia levels and frequent

Transcriptomic profiling of pancreatic alpha, beta and delta cell populations identifies delta cells as a principal target for ghrelin in mouse islets

DEFF Research Database (Denmark)

Adriaenssens, Alice E; Svendsen, Berit; Lam, Brian Y H

2016-01-01

cytometry and analysed by RNA sequencing. The role of the ghrelin receptor was validated by imaging delta cell calcium concentrations using islets with delta cell restricted expression of the calcium reporter GCaMP3, and in perfused mouse pancreases. RESULTS: A database was constructed of all genes...... expressed in alpha, beta and delta cells. The gene encoding the ghrelin receptor, Ghsr, was highlighted as being highly expressed and enriched in delta cells. Activation of the ghrelin receptor raised cytosolic calcium levels in primary pancreatic delta cells and enhanced somatostatin secretion in perfused...... pancreases, correlating with a decrease in insulin and glucagon release. The inhibition of insulin secretion by ghrelin was prevented by somatostatin receptor antagonism. CONCLUSIONS/INTERPRETATION: Our transcriptomic database of genes expressed in the principal islet cell populations will facilitate...

Geochronology of priority pollutants in sedimentation zones of the Volga and Danube delta in comparison with the Rhine delta

International Nuclear Information System (INIS)

Winkels, H.J.; Kroonenberg, S.B.; Lychagin, M.Y.; Marin, G.; Rusakov, G.V.; Kasimov, N.S.

1998-01-01

Six sediment cores were taken in sedimentation zones of the Volga river (located in the southern part of the Russian Federation) and, additionally, 6 sediment cores were taken in several lakes (sedimentation zones) in the central and western part of the Danube delta in Romania. Priority pollutants (8 metals, 7 polychlorinated biphenyls and 10 polycyclic aromatic hydrocarbons) were determined in all samples of all cores. Present-day and historical levels of pollutants since the late 1930s were established through the use of radionuclide time tracers ( 137 Cs, 134 Cs). For the persistent metals and polycyclic aromatic hydrocarbons, trends in the concentration profiles during the last 5 decades are described. Low and hardly changing concentrations of As, Cu, Zn and all studied PAHs were observed during the last five decades in the sediments of the Volga river. Recently deposited sediments show slightly increasing levels for the heavy metals Zn and Cr and As in the Volga delta. For the studied metals and PAHs, maximum concentrations were found around 1987 in the sediments of the Danube delta. Sediments deposited around 1940 and recently deposited sediments in the Danube delta showed lower pollutant levels. If the contents of heavy metals, PAHs and PCBs in the aquatic sediments in the deltas of the rivers Rhine, Danube and Volga are compared, it is clear that the Volga delta is and was the cleanest delta during the last 5 decades. Nowadays the contents of heavy metals (except Cu and Ni), PAHs and PCBs in the aquatic sediments of the river Rhine are still highest compared to the other two rivers. The recent load of heavy metals (except Cd and Zn) in the sediments of the river Danube is the highest compared to the other two rivers. (Copyright (c) 1998 Elsevier Science B.V., Amsterdam. All rights reserved.)

Doubly truncated FosB isoform (Delta2DeltaFosB) induces osteosclerosis in transgenic mice and modulates expression and phosphorylation of Smads in osteoblasts independent of intrinsic AP-1 activity

DEFF Research Database (Denmark)

Sabatakos, George; Rowe, Glenn C; Kveiborg, Marie

2008-01-01

DeltaFosB and a further truncated isoform (Delta2DeltaFosB) that lacks known transactivation domains but, like DeltaFosB, induces increased expression of osteoblast marker genes. MATERIALS AND METHODS: To test Delta2DeltaFosB's ability to induce bone formation in vivo, we generated transgenic mice......6 expression. CONCLUSIONS: DeltaFosB's AP-1 transactivating function is not needed to induce increased bone formation, and Delta2DeltaFosB may act, at least in part, by increasing Smad1 expression, phosphorylation, and translocation to the nucleus....

Delta Cafés (Portugal: Sustainable Business Development

Directory of Open Access Journals (Sweden)

Olgierd Swiatkiewicz

2017-12-01

Full Text Available In the case study of Delta Cafés we discuss the sustainable development of the Portuguese company and brand over the 55 years of their existence. Delta Cafés has already been analyzed in terms of marketing activity, social responsibility, management control systems, etc. In this paper, we refer to these studies, and we reach the sources, i.e. the information provided by the Delta Cafés itself. Due to the nature of the coffee market and the use of case study methodology, we start the presentation of this case from a broader context, describing the coffee market in the world and characterizing the coffee market in Portugal as well. Then we present the history of the development of the company and the brand Delta Cafés. The paper ends with concluding remarks in which we discuss the issues of social and environmental responsibility in the light of the development of Delta Cafés business and brand strategies. 

Measurement of delta-rays in ATLAS silicon sensors

CERN Document Server

The ATLAS collaboration

2013-01-01

In the inner detector of the ATLAS experiment at the LHC, $\\delta$-rays originating from particle interactions in the silicon sensors may cause additional hit channels. A method for identifying silicon hit clusters that are enlarged due to the emission of a $\\delta$-ray is presented. Using pp collision data the expectation is confirmed that the $\\delta$-ray production rate depends linearly on the path length of the particle in silicon, independently of layer radius and detector technology. The range of the $\\delta$-rays, which is a property of the material and should not depend on anything else, is indeed found to be constant as a function of detector layer, path length in silicon and momentum of the particle traversing the silicon. As a by-product of this analysis a method is proposed that could correct for the effect of these $\\delta$-rays, and this could be used to improve track reconstruction.

Research Degrees as Professional Education?

Science.gov (United States)

Barnacle, Robyn; Dall'Alba, Gloria

2011-01-01

There is an increasing trend within higher education and, more specifically, in higher degrees by research, to treat a professional skills set as a desirable graduate outcome. The increasing value that is being placed on a professional skills set in large part reflects growing interest around the world in the role of research degrees in labour…

Studies of Louisiana's Deltas and Wetlands using SAR

Science.gov (United States)

Jones, C. E.

2017-12-01

Sustainable coastal environments exist in delicate balance between subsidence, erosion, and sea level rise on one hand and accretion of sediment and retention of decomposing organic matter on the other. In this talk we present results from a series of studies using an airborne L-band SAR (UAVSAR) to measure changing conditions in the Mississippi River Delta and coastal wetlands of Louisiana. Change within the Mississippi River delta (MRD), which is a highly engineered environment, is contrasted to those in the Wax Lake Delta, a small, naturally evolving delta located to the west of the current-day lobe of the MRD. The UAVSAR studies provide evidence that in the MRD subsidence and erosion related to human activities are increasing risk of flooding, submergence, and land loss. These are not seen in the Wax Lake Delta, where new land is forming. We evaluate geomorphic and hydrologic changes In the Wax Lake Delta and wetlands hydrologically connected to the Wax Lake Outlet canal that are apparent on the timescales of the UAVSAR data set, which consists of both near-yearly acquisitions (2009-2016) and several series of repeat acquisitions in 2015 and 2016 capturing conditions across a tidal cycle. Using the yearly data, we observe the evolution of subaqueous channels and crevasses in the delta and changes in distributary channels within the wetlands. We use water level change derived from InSAR applied to the rapid repeat data acquired during different stages of a tidal cycle to study the natural pattern of water flux within the delta and the coastal wetlands. The studies, results, and plans for future work will be presented. This work was carried out in part at the Jet Propulsion Laboratory, California Institute of Technology, under contracts with the California Dept. of Water Resources and with the National Aeronautics and Space Administration.

Regional dynamics of persistent organic pollutants (POPs) in the Pearl River Delta, China: Implications and perspectives

International Nuclear Information System (INIS)

Zhang Kai; Zhang Baozhong; Li Shaomeng; Zeng, Eddy Y.

2011-01-01

The mass transport budgets of 1,1,1-trichloro-2,2-bis(chlorophenyl)ethane (p,p'-DDT) and decabromodiphenyl ether (BDE-209) in the Pearl River Delta, South China were calculated based on previously collected data. Residual p,p'-DDT, mostly related to historical use, has largely settled into soil (780,000 kg), while the soil BDE-209 inventory (44,000 kg) is considerably smaller. Conversely, large amounts of BDE-209 currently used in numerous commercial products have resulted in a much higher atmospheric depositional flux of BDE-209 (28,100 kg/yr) relative to p,p'-DDT (310 kg/yr). The soil inventory of p,p'-DDT is predicted to decrease to half of its current value after 22 years, and the percent area containing soil p,p'-DDT at levels exceeding the effects range-medium (27 ng/g) will decrease from 40% to 20%. Finally, soil BDE-209 inventory will reach an equilibrium value of 940 tons in ∼60 years, when BDE-209 levels in 50% of soil will be above an equivalent risk guideline value (125 ng/g). - Highlights: → Transport budgets of p,p'-DDT and BDE-209 in the Pearl River Delta were built. → Dry aerial deposition is the dominant route to transport p,p'-DDT and BDE-209. → Soil inventory of p,p'-DDT is much larger than that of BDE-209. → Soil inventory of p,p'-DDT would decline to half of its current value in 22 years. → Soil BDE-209 inventory is expected to reach an equilibrium value in ∼60 years. - Regional dynamics of p,p'-DDT and BDE-209 in the Pearl River Delta (South China) are examined and used to predict temporal variances.

Gender-Specific Differences in Baseline, Peak, and Delta Serum Creatinine: The NACSELD Experience.

Science.gov (United States)

O'Leary, Jacqueline G; Wong, Florence; Reddy, K Rajender; Garcia-Tsao, Guadalupe; Kamath, Patrick S; Biggins, Scott W; Fallon, Michael B; Subramanian, Ram M; Maliakkal, B; Thacker, Leroy; Bajaj, Jasmohan S

2017-03-01

Women have lower serum creatinine values than men for similar renal function. We aimed to determine the differential effect of baseline, peak, and delta creatinine between genders on outcomes in infected hospitalized cirrhotic patients. North American Consortium for the Study of End-Stage Liver Disease is a 15-center consortium of tertiary care hepatology centers prospectively enrolling infected cirrhotic inpatients. Baseline, peak, and delta creatinine during hospitalization were compared between genders, and their impact on overall survival, transplant-free survival, probability of transplantation, and need for renal replacement therapy (RRT) was analyzed. In total, 532 patients with cirrhosis (males = 59% median admission MELD = 20) had significantly lower median baseline (1.07 vs. 1.30 mg/dL, p creatinine (1.47 vs. 1.59 mg/dL, p = 0.024) in women than men during hospitalization for an infection, but both genders had similar delta creatinine levels (0.30 vs. 0.30 mg/dL, p = 0.957). Thirty-day mortality was similar between genders. RRT was not used more often in women (19 vs. 12%, p = 0.050), and women were 1.8 times more likely than men to receive RRT at the same creatinine (p = 0.028). Both peak and delta creatinine significantly predicted 6-month overall and transplant-free survival (p creatinine. Infected hospitalized cirrhotic women are significantly more likely than men to receive RRT at similar creatinine levels. Gender-specific differences in baseline, peak, and delta creatinine need further investigation to determine whether women need acute kidney injury treatment at lower creatinine thresholds than men.

Floating City IJmeer : Accelerator for Delta Technology

NARCIS (Netherlands)

De Graaf, R.; Fremouw, M.; Van Bueren, B.; Czapiewska, K.; Kuijper, M.

2006-01-01

Climate change, sea level rise, population growth and ongoing urbanization result in higher vulnerability of the Rhine delta because it will result in increased flooding frequency, increasing investments and increased use of water, energy and other resources. The Rhine Delta also faces strong

Understanding delta-sigma data converters

CERN Document Server

Pavan, Shanti; Temes, Gabor C

2017-01-01

This new edition introduces novel analysis and design techniques for delta-sigma (ΔΣ) converters in physical and conceptual terms, and includes new chapters that explore developments in the field over the last decade. This book explains the principles and operation of delta-sigma analog-to-digital converters (ADCs) in physical and conceptual terms in accordance with the most recent developments in the field. The interest of ΔΣ converter designers has shifted significantly over the past decade, due to many new applications for data converters at the far ends of the frequency spectrum. Continuous-time delta-sigma A/D converters with GHz clocks, of both lowpass and bandpass types, are required for wireless applications. At the other extreme, multiplexed ADCs with very narrow (sometimes 10 Hz wide) signal bandwidths, but very high accuracy are needed in the interfaces of biomedical and environmental sensors. To reflect the changing eeds of designers, the second edition includes significant new material on bo...

Educational Attainment and Financial Satisfaction: The Changing Economic Value of a College Degree

Science.gov (United States)

Menard, Lauren Ann

2014-01-01

Dwindling American financial satisfaction and growing college degree attainment were revealed in national social survey data spanning more than four decades (N = 57,061). Against these backdrops, associations between being financially satisfied and having a college degree grew stronger in each decade, with the strongest association between…

Isotopic composition of Danube water in the pre-delta section from the years 2009 - 2012

Directory of Open Access Journals (Sweden)

RANK Dieter

2013-12-01

Full Text Available The isotopic composition of river water in the Danube Basin is mainly governed by the isotopic composition of precipitation in the catchment area, evaporation effects play only a minor role. Short-term and long-term isotope signals from precipitation are thus transmitted through the whole catchment. The isotopic composition of Danube water in the Delta region so provides an integrated isotope signal for climatic/hydrological conditions and changes in the whole catchment. The aim of this investigation was to establish a representative isotope monitoring near the Danube Delta. The results showed that the Danube River is regarding isotope content fully mixed at the bifurcation of the Danube Delta arms. Therefore routine sampling at only one location in the pre-delta region should be sufficient to obtain a representative isotope record for the whole Danube Basin. The δ 18 O time series from November 2009 to May 2012 (sampling twice a month shows seasonal variations in the range of -9.8 ‰ ± 0.7 ‰ with a minimum in spring and a maximum in autumn. The tritium results exhibit the influence of short term contaminations due to human activities. The expected “environmental” tritium content of river water in Central Europe would be about 10 TU. During this investigation 3 H values up to 100 TU were observed in the pre-delta section. This indicates short terms releases of tritium from local sources such as nuclear power plants in the Danube river system.

Open source integrated modeling environment Delta Shell

Science.gov (United States)

Donchyts, G.; Baart, F.; Jagers, B.; van Putten, H.

2012-04-01

In the last decade, integrated modelling has become a very popular topic in environmental modelling since it helps solving problems, which is difficult to model using a single model. However, managing complexity of integrated models and minimizing time required for their setup remains a challenging task. The integrated modelling environment Delta Shell simplifies this task. The software components of Delta Shell are easy to reuse separately from each other as well as a part of integrated environment that can run in a command-line or a graphical user interface mode. The most components of the Delta Shell are developed using C# programming language and include libraries used to define, save and visualize various scientific data structures as well as coupled model configurations. Here we present two examples showing how Delta Shell simplifies process of setting up integrated models from the end user and developer perspectives. The first example shows coupling of a rainfall-runoff, a river flow and a run-time control models. The second example shows how coastal morphological database integrates with the coastal morphological model (XBeach) and a custom nourishment designer. Delta Shell is also available as open-source software released under LGPL license and accessible via http://oss.deltares.nl.

The degree of acceptability of swine blood values at increasing levels of hemolysis evaluated through visual inspection versus automated quantification.

Science.gov (United States)

Di Martino, Guido; Stefani, Anna Lisa; Lippi, Giuseppe; Gagliazzo, Laura; McCormick, Wanda; Gabai, Gianfranco; Bonfanti, Lebana

2015-05-01

The pronounced fragility that characterizes swine erythrocytes is likely to produce a variable degree of hemolysis during blood sampling, and the free hemoglobin may then unpredictably bias the quantification of several analytes. The aim of this study was to evaluate the degree of acceptability of values obtained for several biochemical parameters at different levels of hemolysis. Progressively increased degrees of physical hemolysis were induced in 3 aliquots of 30 nonhemolytic sera, and the relative effects on the test results were assessed. To define the level of hemolysis, we used both visual estimation (on a scale of 0 to 3+) and analytical assessment (hemolytic index) and identified the best analytical cutoff values for discriminating the visual levels of hemolysis. Hemolysis led to a variable and dose-dependent effect on the test results that was specific for each analyte tested. In mildly hemolyzed specimens, C-reactive protein, haptoglobin, β1-globulin, β2-globulin, α1-globulin, γ-globulin, sodium, calcium, and alkaline phosphatase were not significantly biased, whereas α2-globulin, albumin, urea, creatinine, glucose, total cholesterol, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, nonesterified fatty acids, bilirubin, phosphorus, magnesium, iron, zinc, copper, lipase, triglycerides, lactate dehydrogenase, unbound iron-binding capacity, and uric acid were significantly biased. Chloride and total protein were unbiased even in markedly hemolyzed samples. Analytical interference was hypothesized to be the main source of this bias, leading to a nonlinear trend that confirmed the difficulty in establishing reliable coefficients of correction for adjusting the test results. © 2015 The Author(s).

Effect of ageing on optical and thermal properties of YBa{sub 2}Cu{sub 3}O{sub 7}-{delta}

Energy Technology Data Exchange (ETDEWEB)

Nikolic, P.M.; Vujatovic, S.S.; Savic, S.M.; Ristic, M.M. [Institute of Technical Sciences of SASA, Belgrade (Czechoslovakia); Paraskevopoulos, K.M.; Zorbas, K.T. [Aristotle Univ., Thessaloniki (Greece). Solid State Section; Nikolic, M.V.; Aleksic, O.S. [Belgrade Univ. (Czechoslovakia). Center for Multidisciplinary Studies

2007-07-15

Photoacoustic phase and amplitude spectra of YBa{sub 2}Cu{sub 3}O{sub 7}-{delta} samples synthesised 18 years ago were measured and numerically analysed. The value of thermal diffusivity obtained on the aged samples was lower than the values obtained for fresh samples. Far infrared spectra of YBa{sub 2}Cu{sub 3}O{sub 7}-{delta} samples synthesised 18 years ago were recorded and analysed enabling determination of reflectivity peak phonon frequencies present at room temperature. X-ray diffraction analysis and far infrared reflectivity measurements enabled determination of a slight change of the oxygen content with time. The YBa{sub 2}Cu{sub 3}O{sub 7}-{delta} samples synthesised 18 years ago still remained superconducting, which was confirmed by resistivity measurements of the samples between 50 K and room temperature where the critical temperature was reduced from 93 to 73 K. Atomic force microscopy, scanning electron microscopy and energy dispersive X-ray microanalytical measurements were also performed confirming the composition of the sample. (orig.)

Water quality in Danube Delta Lakes: An assessment using benthic macroinvertebrates community

Directory of Open Access Journals (Sweden)

IBRAM Orhan

2016-12-01

Full Text Available An assessment of the ecological status of selected lakes in the Danube Delta Biosphere Reserve was done based on temporal and spatial variation of macroinvertebrate communities during 2012 and 2013. Macroinvertebrate communities and measures of these communities were evaluated and a baseline characterization of assemblages was determined for the analyzed sites. Each year, three sampling campaigns, one for each ice-free season were organized for data collection. Macroinvertebrate samples have been collected in every lake from three different stations with the use of an Ekmann dredge. The highest taxa richness are recorded in Fortuna and Isac lakes in 2013. Total abundance followed a pattern similar to taxa number with Fortuna and Isac lakes having the highest yearly values (maximum number of individuals – 225 - per sample has been recorded in September 2013, in Isac Lake.Using saprobic index as an indicator of ecological status Isac lake was classifies as moderate and other three lakes, Merhei, Furtuna and Rosu as good ecological status. Lack of correlation between diversity indices and the saprobic values suggests that other assessment methods could be more effective and provide better information than saprobic index does at least for Danube Delta.

Numerical Solutions of Fifth Order Boundary Value Problems Using

African Journals Online (AJOL)

Dr A.B.Ahmed

1Department of Mathematics Delta State University, Abraka, Nigeria. 2Department of ..... International Journal of Computational. Mathematics and ... Value Problems using Power Series Approximation Method.Applied. Mathematics,. 7,. 1215-.

How Rapid Change Affects Deltas in the Arctic Region

Science.gov (United States)

Overeem, I.; Bendixen, M.

2017-12-01

Deltas form where the river drains into the ocean. Consequently, delta depositional processes are impacted by either changes in the respective river drainage basin or by changes in the regional marine environment. In a warming Arctic region rapid change has occurred over the last few decades in both the terrestrial domain as well as in the marine domain. Important terrestrial controls include 1) change in permafrost possibly destabilizing river banks, 2) strong seasonality of river discharge due to a short melting season, 3) high sediment supply if basins are extensively glaciated, 4) lake outbursts and ice jams favoring river flooding. Whereas in the Arctic marine domain sea ice loss promotes wave and storm surge impact, and increased longshore transport. We here ask which of these factors dominate any morphological change in Arctic deltas. First, we analyze hydrological data to assess change in Arctic-wide river discharge characteristics and timing, and sea ice concentration data to map changes in sea ice regime. Based on this observational analysis we set up a number of scenarios of change. We then model hypothetical small-scale delta formation considering change in these primary controls by setting up a numerical delta model, and combining it dynamically with a permafrost model. We find that for typical Greenlandic deltas changes in river forcing due to ice sheet melt dominate the morphological change, which is corroborated by mapping of delta progradation from aerial photos and satellite imagery. Whereas in other areas, along the North Slope and the Canadian Arctic small deltas are more stable or experienced retreat. Our preliminary coupled model allows us to further disentangle the impact of major forcing factors on delta evolution in high-latitude systems.

The State of Bay–Delta Science 2016: An Introduction

Directory of Open Access Journals (Sweden)

Michael Healey

2016-07-01

Full Text Available doi: http://dx.doi.org/10.15447/sfews.2016v14iss2art5The State of Bay–Delta Science 2016 (SBDS is a collection of papers that summarizes the scientific understanding of the Sacramento–San Joaquin Delta, emphasizing progress made during the past decade.It builds on the first SBDS edition (Healey et al. 2008. Paper topics for this edition address the most relevant scientific issues in the Delta identified by senior scientists and managers. The topical papers cover issues ranging from contaminants in the Delta to levee stability, and from Delta food webs to recent discoveries about salmon migration. These papers are written for a scientific audience. Two additional papers, one describing the challenges of managing water and ecosystems in the Delta and another that discusses policy implications of the recent scientific findings, are written for a general audience. The papers will be published in at least two issues of San Francisco Estuary and Watershed Science and will be available as a set electronically.

{Delta}{sup 14}C level of annual plants and fossil fuel derived CO{sub 2} distribution across different regions of China

Energy Technology Data Exchange (ETDEWEB)

Xi, X.T.; Ding, X.F.; Fu, D.P. [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China); Zhou, L.P. [Laboratory for Earth Surface Processes, Department of Geography, Peking University, Beijing 100871 (China); Liu, K.X., E-mail: kxliu@pku.edu.cn [State Key Laboratory of Nuclear Physics and Technology and Institute of Heavy Ion Physics, School of Physics, Peking University, Beijing 100871 (China)

2013-01-15

The {sup 14}C level in annual plants is a sensitive tracer for monitoring fossil fuel derived CO{sub 2} in the atmosphere. Corn leave samples were selected from different regions of China, including high mountains in the Tibetan Plateau, grassland in Inner Mongolia, and inland and coastal cities during the summer of 2010. The {sup 14}C/{sup 12}C ratio of the samples was measured with the NEC compact AMS system at the Institute of Heavy Ion Physics, Peking University. The fossil fuel derived CO{sub 2} was estimated by comparing the measured {Delta}{sup 14}C values of corn leave samples to background atmospheric {Delta}{sup 14}C level. The influences of topography, meteorological conditions and carbon cycling processes on the fossil fuel derived CO{sub 2} concentration are considered when interpreting the data. Our results show a clear association of the low {Delta}{sup 14}C values with regions where human activities are intensive.

COMPLEX NETWORK SIMULATION OF FOREST NETWORK SPATIAL PATTERN IN PEARL RIVER DELTA

Directory of Open Access Journals (Sweden)

Y. Zeng

2017-09-01

Full Text Available Forest network-construction uses for the method and model with the scale-free features of complex network theory based on random graph theory and dynamic network nodes which show a power-law distribution phenomenon. The model is suitable for ecological disturbance by larger ecological landscape Pearl River Delta consistent recovery. Remote sensing and GIS spatial data are available through the latest forest patches. A standard scale-free network node distribution model calculates the area of forest network’s power-law distribution parameter value size; The recent existing forest polygons which are defined as nodes can compute the network nodes decaying index value of the network’s degree distribution. The parameters of forest network are picked up then make a spatial transition to GIS real world models. Hence the connection is automatically generated by minimizing the ecological corridor by the least cost rule between the near nodes. Based on scale-free network node distribution requirements, select the number compared with less, a huge point of aggregation as a future forest planning network’s main node, and put them with the existing node sequence comparison. By this theory, the forest ecological projects in the past avoid being fragmented, scattered disorderly phenomena. The previous regular forest networks can be reduced the required forest planting costs by this method. For ecological restoration of tropical and subtropical in south China areas, it will provide an effective method for the forest entering city project guidance and demonstration with other ecological networks (water, climate network, etc. for networking a standard and base datum.

The low-temperature structures of Hgsub(3-delta)SbF6 and Hgsub(3-delta)TaF6

International Nuclear Information System (INIS)

Tun, Z.; Brown, I.D.

1986-01-01

The Hg chains in both Hgsub(3-delta)SbF 6 and Hgsub(3-delta)TaF 6 order below room temperature. Down to about 190 K the ordering results from the interaction between parallel chains. It is short range and is different for the two compounds. Below 190 K both compounds transform to an isostructural long-range-ordered phase which is driven by the interaction between perpendicular chains. The structure of this phase in both compounds has been determined. Hgsub(3-delta)SbF 6 at 173 K, delta=0.134(1), Msub(r)=810.6(2). It is monoclinic but pseudotetragonal with I4 1 /amd, a=7.655(1), c=12.558(1) A, V=735.9(2) A 3 , Z=4, Dsub(x)=7.314(3) Mg m -3 , graphite-monochromated Mo Kα radiation, lambda=0.71069 A, μ=64.8 mm -1 , F(000)=1337.1(3). Hgsub(3-delta)TaF 6 at 150 K is isostructural but has delta=0.142(1), Msub(r)=868.2(2), a=7.634(1), c=12.610(2) A, V=734.9(2) A, Dsub(x)=7.844(3) Mg m -3 , μ=76.4 mm -1 , F(000)=1422.6(3). Comparison of the low-temperature structures with those at room temperature shows that the thermal contraction results from the shortening of interatomic distances associated with the weak bonds, with the result that the MF 6 (M=Sb, Ta) host lattice shrinks more than the Hg chains. Variation of the atomic displacement parameters with temperature indicates that the large librational displacements of the MF 6 ion result from thermal motion rather than static disorder. (orig.)

The Use of {delta}{sup 37}CL to Explain Origin and Production of Salt from the Saline Spring 'Fonte da Pipa' in Rio Maior (Central Portugal)

Energy Technology Data Exchange (ETDEWEB)

Eggenkamp, H. G.M.; Marques, J. M. [Centro de Petrologia e Geoquimica, Instituto Superior Tecnico, Lisbon (Portugal); Graca, H. [Centro Hospitalar das Caldas da Rainha, Caldas da Rainha (Portugal)

2013-07-15

Salt extraction in Rio Maior (Central Portugal) is unique in the sense that salt is exploited from a very saline (134 g/L NaCl) terrestrial spring. This spring receives its salt through meteoric water circulation from nearby hills along a shallow salt diapir. This is shown using {delta}{sup 37}Cl, as the composition in dug wells between the mountains and the saline spring is comparable, while {delta}{sup 37}Cl in a well to the east is significantly different. Unlike seawater this spring contains nearly pure NaCl, giving us the opportunity to determine {delta}{sup 37}Cl values in a natural salt precipitating system beyond the point where (in seawater) potassium and magnesium chlorides start to precipitate. {delta}{sup 37}Cl values were determined from brines and by precipitating salt in salt pans with different evaporation stages. Fractionation of up to 1 per mille was found. To complement these natural data, evaporation/precipitation experiments are currently being conducted under controlled laboratory conditions. First results of these experiments indicate that during continued evaporation and precipitation {delta}{sup 37}Cl continues to decrease. (author)

Experimental river delta size set by multiple floods and backwater hydrodynamics.

Science.gov (United States)

Ganti, Vamsi; Chadwick, Austin J; Hassenruck-Gudipati, Hima J; Fuller, Brian M; Lamb, Michael P

2016-05-01

River deltas worldwide are currently under threat of drowning and destruction by sea-level rise, subsidence, and oceanic storms, highlighting the need to quantify their growth processes. Deltas are built through construction of sediment lobes, and emerging theories suggest that the size of delta lobes scales with backwater hydrodynamics, but these ideas are difficult to test on natural deltas that evolve slowly. We show results of the first laboratory delta built through successive deposition of lobes that maintain a constant size. We show that the characteristic size of delta lobes emerges because of a preferential avulsion node-the location where the river course periodically and abruptly shifts-that remains fixed spatially relative to the prograding shoreline. The preferential avulsion node in our experiments is a consequence of multiple river floods and Froude-subcritical flows that produce persistent nonuniform flows and a peak in net channel deposition within the backwater zone of the coastal river. In contrast, experimental deltas without multiple floods produce flows with uniform velocities and delta lobes that lack a characteristic size. Results have broad applications to sustainable management of deltas and for decoding their stratigraphic record on Earth and Mars.

A Modal Logic for Abstract Delta Modeling

NARCIS (Netherlands)

F.S. de Boer (Frank); M. Helvensteijn (Michiel); J. Winter (Joost)

2012-01-01

htmlabstractAbstract Delta Modeling is a technique for implementing (software) product lines. Deltas are put in a partial order which restricts their application and are then sequentially applied to a core product in order to form specific products in the product line. In this paper we explore the

Four new Delta Scuti stars

Science.gov (United States)

Schutt, R. L.

1991-01-01

Four new Delta Scuti stars are reported. Power, modified into amplitude, spectra, and light curves are used to determine periodicities. A complete frequency analysis is not performed due to the lack of a sufficient time base in the data. These new variables help verify the many predictions that Delta Scuti stars probably exist in prolific numbers as small amplitude variables. Two of these stars, HR 4344 and HD 107513, are possibly Am stars. If so, they are among the minority of variable stars which are also Am stars.

Morphodynamics of a cyclic prograding delta: the Red River, Vietnam

NARCIS (Netherlands)

Maren, D.S. van

2004-01-01

River deltas are inhabited by over 60% of the world population, and are, consequently, of paramount agricultural and economical importance. They constitute unique wetland envi ronments which gives river deltas ecological importance as well. Additionally, many deltas contain large accumulations of

Changes to subaqueous delta bathymetry following a high river flow event, Wax Lake Delta, LA, USA

Science.gov (United States)

Whaling, A. R.; Shaw, J.

2017-12-01

Sediment transport capacity is increased during high river flow (flood) events which are characterized by discharges that exceed the 15 year median daily statistic. The Wax Lake Delta (WLD) in coastal Louisiana has experienced 19 of these high flow events in the past 20 years, yet the depositional patterns of single floods are rarely measured in a field-scale deltaic setting. We characterize flood deposition and erosion patterns on the subaqueous portion of the WLD by differencing two Digital Elevation Models (DEMs) constructed from bathymetric surveys before and after the third largest flood in the WLD's recorded history. The total suspended sediment discharge for the 496 day inter-survey period was 2.14x107 cubic meters measured 21 km upstream of the delta apex. The difference map showed 1.06x107 cubic meters of sediment was deposited and 8.2x106 cubic meters was eroded, yielding 2.40x106 cubic meters of net deposition in the survey area ( 79.7 km2 ). Therefore the average deposition rate was 0.061 mm/day. Channel planform remained relatively unchanged for five out of six distributary passes however Gadwall Pass experienced a maximum channel displacement of 166 m ( 1 channel width) measured from the thalweg centerline. Channel tip extension was negligible. In addition, channel displacement was not concentrated at any portion along the channel centerline. Maximum erosion occurred within channel margins and increased upstream whereas maximum deposition occurred immediately outside the channel margins. Sediment eroded from the survey area was either subsequently re-deposited or transported out of the system. Our results show that up to 77.4% of deposition in the survey area originated from sediment eroded during the flood. Surprisingly, only 11.2% of the total suspended sediment discharge was retained in the subaqueous portion of the delta after the flood. We conclude that a high flow event does not produce channel progradation. Rather, high flow causes delta

Delta-9-tetrahydrocannabinol differentially suppresses cisplatin-induced emesis and indices of motor function via cannabinoid CB(1) receptors in the least shrew.

Science.gov (United States)

Darmani, N A

2001-01-01

We have recently shown that the cannabinoid CB(1) receptor antagonist, SR 141716A, produces emesis in the least shrew (Cryptotis parva) in a dose- and route-dependent manner. This effect was blocked by delta-9-tetrahydrocannabinol (Delta(9)-THC). The present study investigates the cannabinoid receptor mechanisms by which Delta(9)-THC produces its antiemetic effects against cisplatin (20 mg/kg, i.p.)-induced emesis as well as its cannabimimetic activity profile (motor reduction) in the least shrew. Intraperitoneal administration of Delta(9)-THC (1, 2.5, 5 and 10 mg/kg) dose-dependently reduced both the percentage of animals vomiting (ID(50)=1.8+/-1.6 mg/kg) and the frequency of vomits (ID(50)=0.36+/-1.18 mg/kg) in a potent manner. The lowest significantly effective antiemetic dose of Delta(9)-THC for the latter emesis parameters was 2.5 mg/kg. Although Delta(9)-THC reduced the frequency of vomits up to 98%, it failed to completely protect all tested shrews from vomiting (80% protection). The cannabinoid CB(1) antagonist (SR 141716A) and not the CB(2) antagonist (SR 144528), reversed the antiemetic effects of Delta(9)-THC in a dose-dependent fashion. Delta(9)-THC (1, 5, 10 and 20 mg/kg, ip) suppressed locomotor parameters (spontaneous locomotor activity, duration of movement and rearing frequency) in a biphasic manner and only the 20-mg/kg dose simultaneously suppressed the triad of locomotor parameters to a significant degree. Subcutaneous (1-10 mg/kg) and intraperitoneal (0.05-40 mg/kg) injection of some doses of SR 141716A caused significant reductions in one or more components of the triad of locomotor parameters but these reductions were not dose dependent. Subcutaneous injection of SR 141716A (0.2, 1, 5 and 10 mg/kg) reversed the motor suppressant effects of a 20-mg/kg dose of Delta(9)-THC (ip) in a dose-dependent manner. Relative to its motor suppressant effects, Delta(9)-THC is a more potent antiemetic agent. Both effects are probably mediated via CB(1

Fracture toughness testing of V-4Cr-4Ti at 25{degrees}C and -196{degrees}C

Energy Technology Data Exchange (ETDEWEB)

Li, H.X.; Kurtz, R.J. [Pacific Northwest National Lab., Richland, WA (United States)

1996-10-01

Measurements of the fracture toughness of the production-scale heat (832665) of V-4Cr-4Ti have been performed at 25{degrees}C and {minus}196{degrees}C using compact tension (CT) specimens. Test specimens were vacuum annealed at either 1000{degrees}C for 1 hour (HT1) or 1050{degrees}C for two hours (HT2). Specimens given the HT1 treatment were annealed after final machining, whereas the HT2 specimens received the 1050{degrees}C anneal at Teledyne Wah Chang prior to final machining. Following machining HT2 specimens were then vacuum annealed at 180{degrees}C for two hours to remove hydrogen. Specimens treated using HT1 had a partially recrystallized microstructure and those treated using HT2 had a fully recrystallized microstructure. The fracture toughness at 25{degrees}C was determined by J-integral tests and at {minus}196{degrees}C by ASTM E 399 type tests. Toughness values obtained at {minus}196{degrees}C were converted to J-integral values for comparison to the 25{degrees}C data. The 25{degrees}C fracture toughness was very high with none of the specimens giving valid results per ASTM criteria. Specimens fractured by microvoid coalescence. The fracture toughness at {minus}196{degrees}C was much lower than that at 25{degrees}C and the fracture surface showed predominantly cleavage features. The present results show a transition from ductile to brittle behavior with decreasing test temperature which is not observed from one-third scale Charpy impact tests. The fracture toughness at {minus}196{degrees}C was still quite high, however, at about 75 kJ/m{sup 2}. Delaminations in planes normal to the thickness direction were seen at both test temperatures. Fracture surfaces inside the delaminations exhibited nearly 100% cleavage facets. The cause of the brittle delaminations was not determined, but will be a subject for further investigation.

DEVELOPMENT ELECTRONIC MAPS OF ECOLOGICAL STATUS OF WATER OBJECTS OF THE VOLGA RIVER DELTA

Directory of Open Access Journals (Sweden)

Z. N. Isenalieva

2016-01-01

Full Text Available Abstract. Aim. The aim of this work was the comprehensive study of the ecological state of water objects of the Volga River delta. Methods. The following methods were used: field (collection, observation, organoleptic, uniform chemical analysis techniques are based on colorimetric, settlement, photometric, spectrometric measurement methods. Results. On the basis of results of researches for 2010-2014 performed a comparative analysis of the dynamics of the content of hydro-chemical indicators of environmental quality in waters of the Volga River delta and the residential areas of the background. Applying an integrated approach to the study of biological indicators of water quality. Created digitized map of the quality of aquatic ecosystems of the Volga River delta. Displaying modern ecological condition of watercourses investigated, determined the degree of contamination, the overall trophic and saprobic. Main conclusions. The work has identified adverse environmental situation in water objects of the Astrakhan and the surrounding areas. Average annual concentrations of toxicological substances water objects in the background zone 10 times less than in the water objects of settlements. As a result of work on the basis of ArcGis 10.2.2 created information environment "Eco-monitor", which is a systematic set of information, and quantitatively characterizing the ecological status of water objects. Created on the basis of ArcGis 10.2.2 information environment monitoring system of waterways allows for a temporary and spatial analysis, to assess the quality of different streams in the control sections.

Modern sedimentation and morphology of the subaqueous Mekong Delta, Southern Vietnam

Science.gov (United States)

Unverricht, Daniel; Szczuciński, Witold; Stattegger, Karl; Jagodziński, Robert; Le, Xuan Thuyen; Kwong, Laval Liong Wee

2013-11-01

The Mekong River Delta is among the Asian mega-deltas and is influenced by various factors including tides (meso-tidal system), waves, coastal currents, monsoon-driven river discharge and human impact (agriculture, fishing, sand dredging, tourism). The present study aims to document the seafloor relief, sediment distribution and sediment accumulation rates to interpret modern sediment transport directions and main sedimentation processes in the subaqueous Mekong Delta. The major results of this investigation include the detection of two delta fronts 200 km apart, one at the mouth of the Bassac River (the biggest branch of the Mekong Delta) and the other around Cape Ca Mau (most south-western end of the Mekong Delta). Additionally, a large channel system runs in the subaqueous delta platform parallel to the shore and between the two fronts. The sediment accumulation rates vary greatly according to the location in the subaqueous delta and have reached up to 10 cm/yr for the last century. A cluster analysis of surface sediment samples revealed two different sediment types within the delta including a well-sorted sandy sediment and a poorly sorted, silty sediment. In addition, a third end member with medium to coarse sand characterised the distant parts of the delta at the transition to the open shelf. The increase of organic matter and carbonate content to the bottom set area and other sedimentary features such as shell fragments, foraminiferas and concretions of palaeo-soils that do not occur in delta sediments, supported grain size-based classification. Beginning in front of the Bassac River mouth, sedimentary pattern indicates clockwise sediment transport alongshore in the western direction to a broad topset area and the delta front around Cape Ca Mau. Our results clearly show the large lateral variability of the subaqueous Mekong Delta that is further complicated by strong monsoon-driven seasonality. River, tidal and wave forcing vary at local and seasonal scales

River Delta Subsidence Measured with Interferometric Synthetic Aperture Radar (InSAR)

Science.gov (United States)

Higgins, Stephanie

This thesis addresses the need for high-resolution subsidence maps of major world river deltas. Driven by a combination of rising water, sediment compaction, and reduced sediment supply due to damming and flood control, many deltas are sinking relative to sea level. A lack of data constraining rates and patterns of subsidence has made it difficult to determine the relative contributions of each factor in any given delta, however, or to assess whether the primary drivers of land subsidence are natural or anthropogenic. In recent years, Interferometric Synthetic Aperture Radar (InSAR) has emerged as a satellite-based technique that can map ground deformation with mm-scale accuracy over thousands of square kilometers. These maps could provide critical insight into the drivers of subsidence in deltas, but InSAR is not typically applied to non-urban delta areas due to the difficulties of performing the technique in wet, vegetated settings. This thesis addresses those difficulties and achieves high-resolution measurements of ground deformation in rural deltaic areas. Chapter 1 introduces the processes that drive relative sea level rise in river deltas and investigates open questions in delta subsidence research. Chapter 2 assesses the performance of InSAR in delta settings and reviews interferogram generation in the context of delta analysis, presenting delta-specific processing details and guiding interpretation in these challenging areas. Chapter 3 applies Differential (D-) InSAR to the coast of the Yellow River Delta in China. Results show that subsidence rates are as high as 250 mm/y due to groundwater extraction at aquaculture facilities, a rate that exceeds local and global average sea level rise by nearly two orders of magnitude and suggests a significant hazard for Asian megadeltas. Chapter 4 applies interferometric stacking and Small Baseline Subset (SBAS)-InSAR to the Ganges-Brahmaputra Delta, Bangladesh. Results show that stratigraphy controls subsidence in

The Great Diversion: Danube Delta under Human Control (Invited)

Science.gov (United States)

Giosan, L.

2009-12-01

Many deltas around the world are suffering from sediment deficits that render them unstable to current and predicted rates of sea level rise. One solution proposed to alleviate the complete or partial drowning of such deltas is the use of river diversions to increase the quantity of sediment supplied to the delta plain to support marsh accretion. We examine the results of a half century old program of diversion in the Danube delta that led to the creation of an extensive diversion channel network akin in scope and size to a natural deltaic network. Danube’s importance as a shipping route increased after the Crimean War in the 1850s; the European Danube Commission was charged with maintaining the Sulina distributary as a shipping channel until 1940s. In the same period, several canals were dug to aid fishing in lakes and bring freshwater to brackish lagoons. After World War II, Communist authorities dramatically increased the number of canals for fishing, fish-farming and reed harvesting. New data on sedimentation rates and estimates of sediment fluxes suggest that the intensive canalization in the second half of the 20th Century led to increased sediment deposition that compensated the decreasing sediment discharge linked to damming within the internal fluvial part of the delta; however, the external marine delta has become increasingly sediment starved during the same interval. We emphasize the similarities and contrasts between the “human-controlled” and natural deltaic channel networks of the Danube delta and discuss the sustainability of the delta as a sediment budget problem within a sea level rise context.

Population dynamics, delta vulnerability and environmental change: comparison of the Mekong, Ganges–Brahmaputra and Amazon delta regions

OpenAIRE

Szabo, S.; Brondizio, E.; Renaud, F.G.; Hetrick, S.; Nicholls, R.; Matthews, Z.; Tessler, Z; Tejedor, A; Sebesvari, Z; Foufoula-Georgiou, E; da Costa, S; Dearing, J.A.

2016-01-01

Tropical delta regions are at risk of multiple threats including relative sea level rise and human alterations, making them more and more vulnerable to extreme floods, storms, surges, salinity intrusion, and other hazards which could also increase in magnitude and frequency with a changing climate. Given the environmental vulnerability of tropical deltas, understanding the interlinkages between population dynamics and environmental change in these regions is crucial for ensuring efficient pol...

On the measurement of the crack tip stress field as a means of determining Delta K(sub eff) under conditions of fatigue crack closure

Science.gov (United States)

Wallhead, Ian R.; Edwards, Lyndon; Poole, Peter

1994-01-01

The optical method of caustics has been successfully extended to enable stress intensity factors as low as 1MPa square root of m to be determined accurately for central fatigue cracks in 2024-T3 aluminium alloy test panels. The feasibility of using this technique to study crack closure, and to determine the effective stress intensity factor range, Delta K(sub eff), has been investigated. Comparisons have been made between the measured values of stress intensity factor, K(sub caus), and corresponding theoretical values, K(sub theo), for a range of fatigue cracks grown under different loading conditions. The values of K(sub caus) and K(sub theo) were in good agreement at maximum stress, where the cracks are fully open, while K(sub caus) exceeded K(sub theo) at minimum stress, due to crack closure. However, the levels of crack closure and values of Delta K(sub eff) obtained could not account for the variations of crack growth rate with loading conditions. It is concluded that the values of Delta K(sub eff), based on caustic measurements in a 1/square root of r stress field well outside the plastic zone, do not fully reflect local conditions which control crack tip behavior.

Cliff´s Delta Calculator: A non-parametric effect size program for two groups of observations

Directory of Open Access Journals (Sweden)

Guillermo Macbeth

2011-05-01

Full Text Available The Cliff´s Delta statistic is an effect size measure that quantifies the amount of difference between two non-parametric variables beyond p-values interpretation. This measure can be understood as a useful complementary analysis for the corresponding hypothesis testing. During the last two decades the use of effect size measures has been strongly encouraged by methodologists and leading institutions of behavioral sciences. The aim of this contribution is to introduce the Cliff´s Delta Calculator software that performs such analysis and offers some interpretation tips. Differences and similarities with the parametric case are analysed and illustrated. The implementation of this free program is fully described and compared with other calculators. Alternative algorithmic approaches are mathematically analysed and a basic linear algebra proof of its equivalence is formally presented. Two worked examples in cognitive psychology are commented. A visual interpretation of Cliff´s Delta is suggested. Availability, installation and applications of the program are presented and discussed.

Metallicism and pulsation: an analysis of the delta Delphini stars

International Nuclear Information System (INIS)

Kurtz, D.W.

1976-01-01

Fine abundance analyses of seven delta Delphini stars and one delta Scuti star relative to four comparison standards are presented. Five of the delta Del stars are shown to have abundances most similar to the evolved Am stars. It is argued that these abundances are different from the classical Am star and Ap star abundances and that similarities to the Ba II star abundances are coincidental. We suggest that the anomalous abundance delta Del stars are evolved metallic line stars on the basis of their abundances, position in the β, M/sub v/ plane, inferred rotational velocities, and perhaps their binary incidence. Some of the delta Del stars are delta Scuti pulsators. We argue that pulsation and metallicism are mutually exclusive among the classical Am stars but may coexist in other stars related to the classical Am stars. A preference for the diffusion hypothesis model for the metallic line stars is stated and supported and the implications of the coexistence of pulsation and diffusion are discussed

Experimental lead intoxication in dogs: a comparison of blood lead and urinary delta-aminolevulinic acid following intoxication and chelation therapy.

Science.gov (United States)

Green, R A; Selby, L A; Zumwalt, R W

1978-01-01

Intravenous lead administration to dogs produced an acute syndrome of lead intoxication charcterized by depression, vomiting, anorexia and weight loss. The effect of chelation therapy with calcium disodium ethylene diamine tetraacetate, penicillamine or both was determined by serially monitoring changes in blood lead and urine delta-aminolevulinic acid. Following therapy, blood lead values were significantly lower in chelated dogs than non-treated lead exposed dogs on days 7 and 10. Urine delta-aminolevulinic acid at day 7 was significantly higher in untreated lead exposed dogs than in other groups. There was no significant difference in blood lead or urine delta-aminolevulinic acid between lead intoxicated dogs which underwent the indicated chelation therapy protocols. There was, however, a trend for higher urinary delta-aminolevulinic acid excretion in those intoxicated dogs undergoing calcium disodium ethylene diamine tetraacetate therapy as opposed to those undergoing penicilamine therapy. There was no significant correlation between blood lead and urinary delta-aminolevulinic acid previous to lead exposure. However, after lead exposure significant correlation was present at days 4, 7, 10 and 14. Certain lead exposed dogs following chelation therapy were noted to have normal blood lead levels but elevated urinary delta-aminolevulinic acid suggesting that blood lead does not always correlate with metabolic effects of lead in the body. Urinary delta-aminolevulinic acid was therefore recommended as an additional laboratory parameter which improved assessment of lead exposure in dogs, particularly in determining adequacy of chelation therapy. PMID:667707

Thermal Models of the Niger Delta: Implications for Charge Modelling

International Nuclear Information System (INIS)

Ejedawe, J.

2002-01-01

There are generally three main sources of temperature data-BHT data from log headers, production temperature data, and continuo's temperature logs. Analysis of continuous temperature profiles of over 100 wells in the Niger Delta two main thermal models (single leg and dogleg) are defined with occasional occurrence of a modified dogleg model.The dogleg model is characterised by a shallow interval of low geothermal gradient ( 3.0.C/100m). This is characteristically developed onshore area is simple, requiring only consideration of heat transients, modelling in the onshore require modelling programmes with built in modules to handle convective heat flow dissipation in the shallow layer. Current work around methods would involve tweaking of thermal conductivity values to mimic the underlying heat flow process effects, or heat flow mapping above and below the depth of gradient change. These methods allow for more realistic thermal modelling, hydrocarbon type prediction, and also more accurate prediction of temperature prior to drilling and for reservoir rock properties. The regional distribution of the models also impact on regional hydrocarbon distribution pattern in the Niger Delta

[Study of the reineta protein modifications (Brama australis), put under freezing and storage to -18 degrees C and -30 degrees C].

Science.gov (United States)

Abugoch, Lilian; Quitral, Vilma; Larraín, M Angélica; Vinagre, Julia; Kriukov, Andrei; Chávez, Gloria

2006-12-01

The objective of the present work was to study functional and thermal properties of reineta (Brama australis) frozen meat, analysed by water retention capacity (WRC), gel forming capacity (GFC), texture, emulsifying capacity and differential scanning calorimetry (DSC). For this study, reineta fillets were obtained and extracted by the same conditions, and cutted, packaged, frozen and stored at -18 degrees C and -30 degrees C for 7 months. The results obtained, showed that there were no signifficant differences in the responses to thermal treatment for all the specimens. For samples frozen at -18 degrees C and -30 degrees C, the protein contents were 23.5 + 0.0 and 25.4 + 1.0%, respectively. The WRC values were 0.45 + 0.1 and 1.59 +/- 0.0 g water/g protein, respectively. The gel forming capacity was only present in the fresh samples, whereas the frozen stored ones only form protein aggregates. The emulsifying capacity was between 960 and 1400 g oil / g protein, and the storage time increased this value. The miosin denaturation temperature (Td) and denaturation enthalpy (?H), obtained by DSC, fluctuated between 39.2 +/- 0.5 to 44.8 +/- 0.8 degrees C and 1.12 +/- 0.3 to 0.52 +/- 0.2 J/g, respectively. The actina values were between 71.0 +/- 0.6 to 75.3 +/- 0.5 degrees C and between 0.5 +/- 0.1 to 0.7 +/- 0.1 J/g. Cooperativity decreased as the storage time increased. This is showing a certain degree of protein displacement. The values found by thermal analyses showed a direct relationship with the functional properties, both decreasing with storage time.

Iron isotope constraints on arsenic release from Mekong Delta sediments, Cambodia

Science.gov (United States)

Matsumoto, T.; Yamaguchi, K. E.; Hirata, T.; Yamagata, Y.; Yamaguchi, A.; Abe, G.

2017-12-01

Arsenic-contaminated groundwater is a world-wide environmental problem and threatens more than 100 million people living in delta areas of South, SE and East Asia. It is typically associated with reducing aquifers with organic-rich alluvial sediments, little thermal gradients, low sulfate concentrations, and slow flushing rates. Such conditions are typical for low-lying countries in Asian deltas; however, compared to Bangladesh, Cambodia has received far less attention. Upon reductive dissolution of Fe-(oxyhydr)oxides that adsorbed As, Fe and As are released into solution as dissolved Fe2+ and arsenate, respectively. Following the oxidation of dissolved Fe2+, newly-formed Fe-(oxyhydr)oxides adsorb As again. Thus, in anoxic waters, concentrations of As correlate with those of dissolved Fe2+. Fluctuating redox conditions in the aquifer are control As release, although inhibition of adsorption of arsenate and arsenite onto the Fe-(oxyhydr)oxides occurs when the concentrations of phosphate, bicarbonate, silicate, and/or organic matter become sufficiently high. Biogeochemical redox reactions of Fe result in significant isotope fractionation (e.g., Johnson et al., 2008). We hypothesized that magnitude of isotope fractionation of Fe in the aquifer sediments, reflecting repeated (incomplete) redox reactions of Fe, may be proportional to the amount of total As release. We aim to calibrate the As release from aquifer sediment by Fe isotope analysis. As a preliminary study, series of sediment samples were collected from the Mekong Delta, Cambodia, in September 2016. Based on measurements by XRF, ICP-AES and ICP-MS, concentrations of As varied significantly covering the range from 4.5 to 15.5 µg/g with a median value of 11 µg/g (higher than the average crustal value of 5 µg/g), and those of Fe is from 2.6 to 9.7 wt.% with a median value of 7.1 wt.%. Concentrations of As and Fe show positive correlation (R2 = 0.72), indicating an effective redox cycling of Fe and As as

Groundwater Flow Model of Göksu Delta Coastal Aquifer System

Science.gov (United States)

Erdem Dokuz, Uǧur; Çelik, Mehmet; Arslan, Şebnem; Engin, Hilal

2016-04-01

Like many other coastal areas, Göksu Delta (Mersin-Silifke, Southern Turkey) is a preferred place for human settlement especially due to its productive farmlands and water resources. The water dependent ecosystem in Göksu delta hosts about 332 different plant species and 328 different bird species besides serving for human use. Göksu Delta has been declared as Special Environmental Protection Zone, Wildlife Protection Area, and RAMSAR Convention for Wetlands of International Importance area. Unfortunately, rising population, agricultural and industrial activities cause degradation of water resources both by means of quality and quantity. This problem also exists for other wetlands around the world. It is necessary to prepare water management plans by taking global warming issues into account to protect water resources for next generations. To achieve this, the most efficient tool is to come up with groundwater management strategies by constructing groundwater flow models. By this aim, groundwater modeling studies were carried out for Göksu Delta coastal aquifer system. As a first and most important step in all groundwater modeling studies, geological and hydrogeological settings of the study area have been investigated. Göksu Delta, like many other deltaic environments, has a complex structure because it was formed with the sediments transported by Göksu River throughout the Quaternary period and shaped throughout the transgression-regression periods. Both due to this complex structure and the lack of observation wells penetrating deep enough to give an idea of the total thickness of the delta, it was impossible to reveal out the hydrogeological setting in a correct manner. Therefore, six wells were drilled to construct the conceptual hydrogeological model of Göksu Delta coastal aquifer system. On the basis of drilling studies and slug tests that were conducted along Göksu Delta, hydrostratigraphic units of the delta system have been obtained. According to

Multiple linear regression and artificial neural networks for delta-endotoxin and protease yields modelling of Bacillus thuringiensis.

Science.gov (United States)

Ennouri, Karim; Ben Ayed, Rayda; Triki, Mohamed Ali; Ottaviani, Ennio; Mazzarello, Maura; Hertelli, Fathi; Zouari, Nabil

2017-07-01

The aim of the present work was to develop a model that supplies accurate predictions of the yields of delta-endotoxins and proteases produced by B. thuringiensis var. kurstaki HD-1. Using available medium ingredients as variables, a mathematical method, based on Plackett-Burman design (PB), was employed to analyze and compare data generated by the Bootstrap method and processed by multiple linear regressions (MLR) and artificial neural networks (ANN) including multilayer perceptron (MLP) and radial basis function (RBF) models. The predictive ability of these models was evaluated by comparison of output data through the determination of coefficient (R 2 ) and mean square error (MSE) values. The results demonstrate that the prediction of the yields of delta-endotoxin and protease was more accurate by ANN technique (87 and 89% for delta-endotoxin and protease determination coefficients, respectively) when compared with MLR method (73.1 and 77.2% for delta-endotoxin and protease determination coefficients, respectively), suggesting that the proposed ANNs, especially MLP, is a suitable new approach for determining yields of bacterial products that allow us to make more appropriate predictions in a shorter time and with less engineering effort.

Mesquite Risk Mapping and Assessment in Tokar Delta-Eastern Sudan

OpenAIRE

Suliman, Mahgoub; NAWATA, Hiroshi; Hoshino, Buho; Karamalla, Abdelaziz

2015-01-01

Tokar Delta is a name given to a small delta of approximately 161,000 hectares situated in the southern area of the Red Sea in Eastern Sudan. Beginning of 1980, mesquite species (Prosopis chilensis & Prosopis juliflora) were introduced to Tokar area to be planted as a shelterbelt for the city Tokar, but after while; it spread out to the delta area and became an invasive plant to the agricultural lands and along Khor Barak banks. Nowadays mesquite covers more than half of the delta area, decre...

(p,. pi. /sup -/) reaction and. delta. /sup + +/ components of nuclei

Energy Technology Data Exchange (ETDEWEB)

Kisslinger, L S; Miller, G A [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

1975-12-08

The use of the (p,..pi../sup -/) reaction as a probe to determine ..delta../sup + +/(1232) components of nuclear wave functions is examined within the framework of a model which treats baryon resonances on the same footing as nucleons. Nuclear structure properties which affect the ..delta..-probability are discussed. Estimates of cross sections, at several energies, are made for the ..delta../sup + +/ transfer contribution as well as for the competing processes: proton charge exchange (p,n) followed by an (n,..gamma../sup -/) reaction; emission of a ..pi../sup 0/ followed by pion charge exchange (..pi../sup -/,..pi../sup 0/). Even with ..delta..-probabilities as small as 0.0001 the ..delta..-transfer process can compete with ordinary background charge-exchange reactions.

Polarized antiquark flavor asymmetry DELTA anti u(x)-DELTA anti d(x) and the pion cloud

CERN Document Server

Fries, R J; Weiss, C

2003-01-01

The flavor asymmetry of the unpolarized antiquark distributions in the proton, anti u(x)- anti d(x)0. Using a simple chiral linear sigma model as an example, we demonstrate that in the meson cloud picture a large positive DELTA anti u(x)-DELTA anti d(x) can be obtained from pi-sigma interference contributions. This calls into question previous estimates based on rho-meson contributions alone, and indicates how the results of the meson cloud picture may be reconciled with those of quark-based models. (orig.)

Delta agent (Hepatitis D)

Science.gov (United States)

... this page: //medlineplus.gov/ency/article/000216.htm Hepatitis D (Delta agent) To use the sharing features on this page, please enable JavaScript. Hepatitis D is a viral infection caused by the ...

SU-F-T-294: The Analysis of Gamma Criteria for Delta4 Dosimetry Using Statistical Process Control

Energy Technology Data Exchange (ETDEWEB)

Cho, S; Ahn, S; Kim, J; Park, K; Choi, W; Lee, H; Lee, E; Yoon, J; Keum, K [Yonsei Univeristy, Seoul (Korea, Republic of)

2016-06-15

Purpose: To evaluate the sensitivity of gamma criteria for patient-specific volumetric modulated arc therapy(VMAT) quality assurance of the Delta{sup 4} dosimetry program using the statistical process control(SPC) methodology. Methods: The authors selected 20 patient-specific VMAT QA cases which were undertaken MapCHECK and ArcCHECK with gamma pass rate better than 97%. The QAs data were collected Delta4 Phantom+ and Elekta Agility six megavolts without using an angle incrementer. The gamma index(GI) were calculated in 2D planes with normalizing deviation to local dose(local gamma). The sensitivity of the GI methodology using criterion of 3%/3mm, 3%/2mm and 2%/3mm was analyzed with using process acceptability indices. We used local confidence(LC) level, the upper control limit(UCL) and lower control limit(LCL) of I-MR chart for process capability index(Cp) and a process acceptability index (Cpk). Results: The lower local confidence levels of 3%/3mm, 3%/2mm and 2%/3mm were 92.0%, 83.6% and 78.8% respectively. All of the calculated Cp and Cpk values that used LC level were under 1.0 in this study. The calculated LCLs of I-MR charts were 89.5%, 79.0% and 70.5% respectively. These values were higher than 1.0 which means good quality of QA. For the generally used lower limit of 90%, we acquired over 1.3 of Cp value for the gamma index of 3%/3mm and lower than 1.0 in the rest of GI. Conclusion: We applied SPC methodology to evaluate the sensitivity of gamma criteria and could see the lower control limits of VMAT QA for the Delta 4 dosimetry and could see that Delta 4 phantom+ dosimetry more affected by the position error and the I-MR chart derived values are more suitable for establishing lower limits. Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (No. 2015R1D1A1A01060463)

SU-F-T-294: The Analysis of Gamma Criteria for Delta4 Dosimetry Using Statistical Process Control

International Nuclear Information System (INIS)

Cho, S; Ahn, S; Kim, J; Park, K; Choi, W; Lee, H; Lee, E; Yoon, J; Keum, K

2016-01-01

Purpose: To evaluate the sensitivity of gamma criteria for patient-specific volumetric modulated arc therapy(VMAT) quality assurance of the Delta 4 dosimetry program using the statistical process control(SPC) methodology. Methods: The authors selected 20 patient-specific VMAT QA cases which were undertaken MapCHECK and ArcCHECK with gamma pass rate better than 97%. The QAs data were collected Delta4 Phantom+ and Elekta Agility six megavolts without using an angle incrementer. The gamma index(GI) were calculated in 2D planes with normalizing deviation to local dose(local gamma). The sensitivity of the GI methodology using criterion of 3%/3mm, 3%/2mm and 2%/3mm was analyzed with using process acceptability indices. We used local confidence(LC) level, the upper control limit(UCL) and lower control limit(LCL) of I-MR chart for process capability index(Cp) and a process acceptability index (Cpk). Results: The lower local confidence levels of 3%/3mm, 3%/2mm and 2%/3mm were 92.0%, 83.6% and 78.8% respectively. All of the calculated Cp and Cpk values that used LC level were under 1.0 in this study. The calculated LCLs of I-MR charts were 89.5%, 79.0% and 70.5% respectively. These values were higher than 1.0 which means good quality of QA. For the generally used lower limit of 90%, we acquired over 1.3 of Cp value for the gamma index of 3%/3mm and lower than 1.0 in the rest of GI. Conclusion: We applied SPC methodology to evaluate the sensitivity of gamma criteria and could see the lower control limits of VMAT QA for the Delta 4 dosimetry and could see that Delta 4 phantom+ dosimetry more affected by the position error and the I-MR chart derived values are more suitable for establishing lower limits. Acknowledgement: This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education (No. 2015R1D1A1A01060463)

Estimating Air Particulate Matter Using MODIS Data and Analyzing Its Spatial and Temporal Pattern over the Yangtze Delta Region

Directory of Open Access Journals (Sweden)

Jianhui Xu

2016-09-01

Full Text Available The deteriorating air quality in the Yangtze delta region is attracting growing public concern. In this paper, seasonal estimation models of the surface particulate matter (PM were established by using aerosol optical thickness (AOT retrievals from the moderate resolution imaging spectro-radiometer (MODIS on board NASA’s Terra satellite. The change of the regional distribution of the atmospheric mixed layer, relative humidity and meteorological elements have been taken into account in these models. We also used PM mass concentrations of ground measurements to evaluate the estimation accuracy of those models. The results show that model estimation of PM2.5 and PM10 mass concentrations were in good agreement with the ground-based observation of PM mass concentrations (p < 0.01, the R2 value of the PM2.5 concentrations experimental model for four seasons are 0.48, 0.62, 0.61 and 0.52 respectively. The R2 value of PM10 concentrations experimental model for four seasons are 0.57, 0.56, 0.64 and 0.68 respectively. At the same time, spatial and temporal variations of PM2.5 and PM10 mass concentrations were analysed over the Yangtze delta region from 2000 to 2013. The results show that PM2.5 and PM10 show a trend of increase in the Yangtze delta region from 2000 to 2013 and change periodically. The maximum mass concentration of PM2.5 and PM10 was in January–February, and the minimum was in July–August. The highest values of PM2.5 and PM10 mass concentration are in the region of urban agglomeration which is grouped to a delta-shaped region by Shanghai, Hangzhou and Nanjing, while the low values are in the forest far away from the city. PM mass concentration over main cities and rural areas increased gradually year by year, and were increasing more quickly in urban areas than in rural areas.

Impact of alpha-, gamma-, and delta-tocopherol on the radiation induced oxidation of rapeseed oil triacylglycerols

Energy Technology Data Exchange (ETDEWEB)

Braunrath, Robert; Isnardy, Bettina; Solar, Sonja, E-mail: sonja.solar@univie.ac.at; Elmadfa, Ibrahim

2010-07-15

Gamma-irradiation (doses: 2, 4, 7, and 10 kGy) was used as oxidation tool to study the antioxidant effects of alpha-, gamma-, and delta-tocopherol (enrichments 500-5000 ppm) in purified rapeseed oil triacylglycerols (RSOTG). Fatty acid composition, tocopherol degradation, primary (conjugated dienes (CD) and peroxide value (POV)) and secondary (p-anisidine value) oxidation products were chosen as test parameters. Fatty acid composition did not change. While secondary oxidation products could not be found in the irradiated samples, the POVs and CDs showed a significant, dose-dependent increase. alpha-Tocopherol did not inhibit the formation of peroxides, whereas gamma- and delta-tocopherol reduced the POVs by more than 30%. No uniform effect of the different tocopherol concentrations at the particular doses could be established. The influence of the individual tocopherols on the CD formation was not pronounced. The degradation of the tocopherols decreased with increasing concentration. None of the tocopherols showed a prooxidant effect.

Contaminant Effects on California Bay–Delta Species and Human Health

Directory of Open Access Journals (Sweden)

Stephanie Fong

2016-12-01

Full Text Available doi: https://doi.org/10.15447/sfews.2016v14iss4art5Many contaminants in the California Bay–Delta (Bay–Delta exceed regulatory standards, affect aquatic species, and potentially affect human health. Recent studies provide multiple lines of evidence that contaminants affect species of concern in the Bay–Delta (e.g., the decline of several important fish species referred to as the “Pelagic Organism Decline” or POD. Contaminants occur as dynamic complex mixtures and exert effects at multiple levels of biological organization. Multiple chemicals impair processes at cellular and physiological levels (measured as growth, development, and behavior abnormalities, and when viability and reproductive output are affected, populations are affected. As an important example, the population decline of the endangered Delta Smelt (Hypomesus transpacificus is significantly associated with multiple stressors, including insecticide use. New analyses presented in this paper show significant correlations between pyrethroid use and declining abundance of POD fish species. Water sampled from the Bay–Delta causes multiple deleterious effects in fish, and Delta Smelt collected from the Bay–Delta exhibit contaminant effects. Fish prey items are also affected by contaminants; this may have an indirect effect on their populations. Co-occurrence with thermal changes or disease can exacerbate contaminant effects. Contaminants also pose threats to human health via consumption of fish and shellfish, drinking water, and contact recreation, in particular, mercury, cyanobacteria toxins, disinfection byproducts, pathogens, pesticides, and pharmaceuticals and personal care products. The role of contaminants in the decline of Bay–Delta species is difficult to accurately assess in a complex, dynamic system. However, tools and approaches are available to evaluate contaminant effects on Bay–Delta species, and separate the effects of multiple stressors. Integrated

Hepatitis delta in HIV-infected individuals in Europe

DEFF Research Database (Denmark)

Soriano, Vincent; Grint, Daniel; Monforte, Antonellad'arminio

2011-01-01

BACKGROUND:: Hepatitis delta virus (HDV) infection results in the most aggressive form of chronic viral hepatitis. There is scarce information about the prevalence, epidemiology, virological profile and natural historyof hepatitis delta in HIV patients. METHODS:: From 16,597 HIV patients enrolled......-RNA was quantified using a real-time PCR method. RESULTS:: A total of 61/422 HBsAg+ carriers were anti-HDV+ (prevalence: 14.5%). Hepatitis delta predominated in intravenous drug users and for this reason in South and/or East Europe. Serum HDV-RNA was detectable in 87% of tested anti-HDV+ patients, with a median...... titer of 1.76x10¿copies/ml. Overall, delta hepatitis patients showed lower serum HBV-DNA than the rest of HBsAg+ carriers, although the inhibitory effect of HDV on HBV replication was not recognized in HBV genotype D patients.Whereas HDV was not associated with progression to AIDS, it significantly...

The Niger Delta Crisis

African Journals Online (AJOL)

chifaou.amzat

2013-09-28

Sep 28, 2013 ... Department of History & International Studies, Delta State University, Abraka,. Nigeria. .... democracy implies popular power. That is ... Okonta (2006:5) draws attention to Anna Zalik's treatise called 'Petro-Vio- lence' and ...

Breaking down the delta wing vortex: The role of vorticity in the breakdown process

Science.gov (United States)

Nelson, R. C.; Visser, Kenneth Dale

1991-01-01

Experimental x-wire measurements of the flowfield above a 70 degree and 75 degree flat plate delta wing were performed at a Reynolds number of 250,000. Grids were taken normal to the wing at various chordwise locations for angles of attack of 20 degrees and 30 degrees. Axial and azimuthal vorticity distributions were derived from the velocity fields. The dependence of circulation on distance from the vortex core and on chordwise location was also examined. The effects of nondimensionalization in comparison with other experimental data is made. The results indicate that the circulation distribution scales with the local semispan and grows in a nearly linear fashion in the chordwise direction. The spanwise distribution of axial vorticity is severely altered through the breakdown region and the amount of vorticity present appears to reach a maximum immediately preceding breakdown. The axial velocity components with a negative sense, such as that found in the secondary vortex, seem to remain unaffected by changes in wing sweep or angle of attack, in direct contrast to the visible components. In addition, the inclusion of the local wing geometry into a previously derived correlation parameter allows the circulation of growing leading edge vortex flows to be reduced to a single curve.

T gamma/delta lymphocytes in renal transplant recipients

NARCIS (Netherlands)

Raasveld, M. H.; Bloemena, E.; Surachno, S.; ten Berge, R. J.

1992-01-01

T gamma/delta lymphocytes are able to perform allospecific cytotoxicity and natural killer cytotoxicity in vitro. However, very little is known about their function in vivo. To investigate the possible involvement of T gamma/delta lymphocytes in the immune response to renal allografts, fine-needle

An integrated assessment framework for land subsidence in delta cities

Directory of Open Access Journals (Sweden)

T. H. M. Bucx

2015-11-01

Full Text Available In many delta cities land subsidence exceeds absolute sea level rise up to a factor of ten by excessive groundwater extraction related to rapid urbanization and population growth. Without change, parts of Jakarta, Ho Chi Minh City, Bangkok and numerous other delta (and coastal cities will sink below sea level. Increased flooding and also other widespread impacts of land subsidence result already in damage of billions of dollars per year. In order to gain insight in the complex, multi-sectoral aspects of subsidence, to raise awareness and to support decision making on appropriate adaptation strategies and measures, an Integrated Assessment Framework (IAF for subsidence is introduced, illustrated by several (delta case studies. Based on that a list of 10 generic key issues and possible solutions is presented in order to further develop and support a (generic approach how to deal with subsidence in current and future subsidence-prone areas. For exchange of experiences and knowledge development.on subsidence in deltas the Delta Alliance, a knowledge network of deltas worldwide, can be supportive.

Delta ferrite in the weld metal of reduced activation ferritic martensitic steel

Energy Technology Data Exchange (ETDEWEB)

Sam, Shiju, E-mail: shiju@ipr.res.in [Institute for Plasma Research, Gandhinagar, Gujarat 382 428 (India); Das, C.R.; Ramasubbu, V.; Albert, S.K.; Bhaduri, A.K.; Jayakumar, T. [Indira Gandhi Centre for Atomic Research, Kalpakkam 603 102 (India); Rajendra Kumar, E. [Institute for Plasma Research, Gandhinagar, Gujarat 382 428 (India)

2014-12-15

Formation of delta(δ)-ferrite in the weld metal, during autogenous bead-on-plate welding of Reduced Activation Ferritic Martensitic (RAFM) steel using Gas Tungsten Arc Welding (GTAW) process, has been studied. Composition of the alloy is such that delta-ferrite is not expected in the alloy; but examination of the weld metal revealed presence of delta-ferrite in the weld metal. Volume fraction of delta-ferrite is found to be higher in the weld interface than in the rest of the fusion zone. Decrease in the volume fraction of delta-ferrite, with an increase in preheat temperature or with an increase in heat input, is observed. Results indicate that the cooling rate experienced during welding affects the volume fraction of delta-ferrite retained in the weld metal and variation in the delta-ferrite content with cooling rate is explained with variation in the time that the weld metal spends in various temperature regimes in which delta-ferrite is stable for the alloy during its cooling from the liquid metal to the ambient temperature. This manuscript will discuss the effect of welding parameters on formation of delta-ferrite and its retention in the weld metal of RAFM steel.

Optimal Design and Tuning of PID-Type Interval Type-2 Fuzzy Logic Controllers for Delta Parallel Robots

Directory of Open Access Journals (Sweden)

Xingguo Lu

2016-05-01

Full Text Available In this work, we propose a new method for the optimal design and tuning of a Proportional-Integral-Derivative type (PID-type interval type-2 fuzzy logic controller (IT2 FLC for Delta parallel robot trajectory tracking control. The presented methodology starts with an optimal design problem of IT2 FLC. A group of IT2 FLCs are obtained by blurring the membership functions using a variable called blurring degree. By comparing the performance of the controllers, the optimal structure of IT2 FLC is obtained. Then, a multi-objective optimization problem is formulated to tune the scaling factors of the PID-type IT2 FLC. The Non-dominated Sorting Genetic Algorithm (NSGA-II is adopted to solve the constrained nonlinear multi-objective optimization problem. Simulation results of the optimized controller are presented and discussed regarding application in the Delta parallel robot. The proposed method provides an effective way to design and tune the PID-type IT2 FLC with a desired control performance.

Delta count-rate monitoring system

International Nuclear Information System (INIS)

Van Etten, D.; Olsen, W.A.

1985-01-01

A need for a more effective way to rapidly search for gamma-ray contamination over large areas led to the design and construction of a very sensitive gamma detection system. The delta count-rate monitoring system was installed in a four-wheel-drive van instrumented for environmental surveillance and accident response. The system consists of four main sections: (1) two scintillation detectors, (2) high-voltage power supply amplifier and single-channel analyzer, (3) delta count-rate monitor, and (4) count-rate meter and recorder. The van's 6.5-kW generator powers the standard nuclear instrument modular design system. The two detectors are mounted in the rear corners of the van and can be run singly or jointly. A solid-state bar-graph count-rate meter mounted on the dashboard can be read easily by both the driver and passenger. A solid-state strip chart recorder shows trends and provides a permanent record of the data. An audible alarm is sounded at the delta monitor and at the dashboard count-rate meter if a detected radiation level exceeds the set background level by a predetermined amount

Carbon storage in the Mississippi River delta enhanced by environmental engineering

Science.gov (United States)

Shields, Michael R.; Bianchi, Thomas S.; Mohrig, David; Hutchings, Jack A.; Kenney, William F.; Kolker, Alexander S.; Curtis, Jason H.

2017-11-01

River deltas have contributed to atmospheric carbon regulation throughout Earth history, but functioning in the modern era has been impaired by reduced sediment loads, altered hydrologic regimes, increased global sea-level rise and accelerated subsidence. Delta restoration involves environmental engineering via river diversions, which utilize self-organizing processes to create prograding deltas. Here we analyse sediment cores from Wax Lake delta, a product of environmental engineering, to quantify the burial of organic carbon. We find that, despite relatively low concentrations of organic carbon measured in the cores (about 0.4%), the accumulation of about 3 T m-2 of sediment over the approximate 60 years of delta building resulted in the burial of a significant amount of organic carbon (16 kg m-2). This equates to an apparent organic carbon accumulation rate of 250 +/- 23 g m-2 yr-1, which implicitly includes losses by carbon emissions and erosion. Our estimated accumulation rate for Wax Lake delta is substantially greater than previous estimates based on the top metre of delta sediments and comparable to those of coastal mangrove and marsh habitats. The sedimentation of carbon at the Wax Lake delta demonstrates the capacity of engineered river diversions to enhance both coastal accretion and carbon burial.

The impact of human activities in the Wulan Delta Estuary, Indonesia

Science.gov (United States)

Fadlillah, L. N.; Sunarto; Widyastuti, M.; Marfai, M. A.

2018-04-01

The increasing of human population in the watershed and the coastal area and the need of life exert pressure in the delta that provides various resources. Wulan Delta is one of active Delta in Central Java, Indonesia. It has been experienced multiple pressures because of natural factors and human factors. In order to provide the scientific solution and to analyze the impact of human intervention in delta, we collected several pieces of evidence based on secondary data and primary data. The secondary data is water quality data on sites 6 and 7, meanwhile the secondary data is the water quality data in site 1 to 5. This paper present a review and problems identification in Wulan Delta, based on hydrological condition, land use, and human activities in the delta. Meanwhile, the human intervention in the land which is land use exchange leads to several problems such as the land use changes, high sediment load, and water degradation. Almost 80% of Delta has been transformed into the fish pond by local communities.

Application of Multi-Valued Weighting Logical Functions in the Analysis of a Degree of Importance of Construction Parameters on the Example of Hydraulic Valves

Science.gov (United States)

Deptuła, A.

2014-08-01

In the optimization process, changes in the construction parameters value influence the behaviour of functions depending on time. Weighting logical coefficients for the stabilisation time are taken into consideration here, i.e., a shorter (better) stabilisation time has a more important (bigger) value of the weighting coefficient. An example of applying weighting logical functions in the analysis of a degree of importance of construction parameters of a hydraulic valve is presented in the paper

Challenges and Approaches in River Delta Planning - report on training workshop

NARCIS (Netherlands)

Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

2012-01-01

River delta’s, like the Mekong Delta (Vietnam), Ganges-Brahmaputra Delta (Bangladesh), Irrawady (Myanmar) and Ciliwung Delta (Indonesia) are developing rapidly and characterized by large-scale urbanization and industrialization processes. They are facing serious planning challenges related to issues

Spring-Summer Temperatures Since AD 1780 Reconstructed from Stable Oxygen Isotope Ratios in White Spruce Tree-Rings from the Mackenzie Delta, Northwestern Canada

Science.gov (United States)

Porter, Trevor J.; Pisaric, Michael F. J.; Field, Robert D.; Kokelj, Steven V.; Edwards, Thomas W. D.; deMontigny, Peter; Healy, Richard; LeGrande, Allegra N.

2013-01-01

High-latitude delta(exp 18)O archives deriving from meteoric water (e.g., tree-rings and ice-cores) can provide valuable information on past temperature variability, but stationarity of temperature signals in these archives depends on the stability of moisture source/trajectory and precipitation seasonality, both of which can be affected by atmospheric circulation changes. A tree-ring delta(exp 18)O record (AD 1780-2003) from the Mackenzie Delta is evaluated as a temperature proxy based on linear regression diagnostics. The primary source of moisture for this region is the North Pacific and, thus, North Pacific atmospheric circulation variability could potentially affect the tree-ring delta(exp 18)O-temperature signal. Over the instrumental period (AD 1892-2003), tree-ring delta(exp 18)O explained 29% of interannual variability in April-July minimum temperatures, and the explained variability increases substantially at lower-frequencies. A split-period calibration/verification analysis found the delta(exp 18)O-temperature relation was time-stable, which supported a temperature reconstruction back to AD 1780. The stability of the delta(exp 18)O-temperature signal indirectly implies the study region is insensitive to North Pacific circulation effects, since North Pacific circulation was not constant over the calibration period. Simulations from the NASA-GISS ModelE isotope-enabled general circulation model confirm that meteoric delta(exp 18)O and precipitation seasonality in the study region are likely insensitive to North Pacific circulation effects, highlighting the paleoclimatic value of tree-ring and possibly other delta(exp 18)O records from this region. Our delta(exp 18)O-based temperature reconstruction is the first of its kind in northwestern North America, and one of few worldwide, and provides a long-term context for evaluating recent climate warming in the Mackenzie Delta region.

Conflict resolution among Niger delta communities: A historical ...

African Journals Online (AJOL)

Conflict related issues have assumed endemic proportion in the Niger Delta. A proper assessment of the critical factors in motion must take cognizance of their historical underpinnings. Peaceful co-existence, the hallmark of conflict resolution, can be feasible in the Niger Delta, through sustainable dialogue. These, among

Correlation of irradiation-induced transition temperature increases from C sub v and K sub Jc /K sub Ic data

Energy Technology Data Exchange (ETDEWEB)

Hiser, A.L. (Materials Engineering Associates, Inc., Lanham, MD (USA))

1990-03-01

Reactor pressure vessel (RPV) surveillance capsules contain Charpy-V (C{sub v}) specimens, but many do not contain fracture toughness specimens; accordingly, the radiation-induced shift (increase) in the brittle-to-ductile transition region ({Delta}T) is based upon the {Delta}T determined from notch ductility (C{sub v}) tests. Since the ASME K{sub Ic} and K{sub IR} reference fracture toughness curves are shifted by the {Delta}T from C{sub v}, assurance that this {Delta}T does not underestimate {Delta}T associated with the actual irradiated fracture toughness is required to provide confidence that safety margins do not fall below assumed levels. To assess this behavior, comparisons of {Delta}T's defined by elastic-plastic fracture toughness and C{sub v} tests have been made using data from RPV base and weld metals in which irradiations were made under test reactor conditions. Using as-measure'' fracture toughness values (K{sub Jc}), average comparisons between {Delta}T(C{sub v}) and {Delta}T(K{sub Jc}) are: (a) All data: {Delta}T(K{sub Jc} 100 MPa{radical}{bar m}) = {Delta}T(C{sub v} 41 J) +10{degree}C; (b) Plates only: {Delta}T(K{sub Jc} 100 MPa{radical}{bar m}) = {Delta}T(C{sub v} 41 J) +15{degree}C; and (c) Welds only: {Delta}T(K{sub Jc} 100 MPa{radical}{bar m}) = {Delta}T(C{sub v} 41 J) {minus}1{degree}C. Fluence rate is found to have no significant effect on the relationship between {Delta}T(C{sub v}) and {Delta}T(K{sub Jc}). 12 refs., 12 figs., 5 tabs.

Environmental Risk Profiling of the Volta Delta, Ghana

Science.gov (United States)

Nyarko, B. K.; Appeaning-Addo, K.; Amisigo, B.

2017-12-01

Volta Delta communities find it difficult to absorb or bear risk at different levels, because of the physical and economic impacts of environmental hazards. In this regards various agencies and organizations have in recent years launched initiatives to measure and identify risk areas with a set of indicators and indices. The theory underpinning this study is concepts of Modern Portfolio Theory (MPT). The Cox proportional hazards regression model will be used as the model for the risk profile. Finding the optimal level of environmental risk for activities in the Volta Delta considering the risk required, risk capacity and risk tolerance. Using data from different sources, an environmental risk profile was developed for the Volta Delta. The result indicates that risks are distributed across the Delta. However, areas that have government interventions, such as sea defense system and irrigation facilities have less threat. In addition wealthy areas do effectively reduce the threat of any form of disaster.

VTVH-MCD study of the Delta nifB Delta nifZ MoFe protein from Azotobacter vinelandii.

Science.gov (United States)

Cotton, Marcia S; Rupnik, Kresimir; Broach, Robyn B; Hu, Yilin; Fay, Aaron W; Ribbe, Markus W; Hales, Brian J

2009-04-08

NifZ is a member of a series of proteins associated with the maturation of the nitrogenase MoFe protein. An MCD spectroscopic study was undertaken on the Delta nifB Delta nifZ MoFe protein generated in the absence of both NifZ and NifB (deletion of NifB generates an apo-MoFe protein lacking the FeMo cofactor). Results presented here show that, in the absence of NifZ, only one of the two P-clusters of the MoFe protein is matured to the ultimate [8Fe-7S] structure. The other P-cluster site in the protein contains a [4Fe-4S] cluster pair, representing a P-cluster precursor that is electronically identical to the analogous clusters observed in the Delta nifH MoFe protein. These results suggest that the MoFe protein is synthesized in a stepwise fashion where NifZ is specifically required for the formation of the second P-cluster.

78 FR 45592 - DeltaPoint Capital IV, LP;

Science.gov (United States)

2013-07-29

..., Suite 160, Pittsford, NY 14534. The financing was contemplated for working capital. The financing is... SMALL BUSINESS ADMINISTRATION [License No. 02/02-0662] DeltaPoint Capital IV, LP; Notice Seeking... given that DeltaPoint Capital IV, L.P., 45 East Avenue, 6th Floor, Rochester, NY 14604, Federal...

Towards a Comprehensive Framework for Adaptive Delta Management

NARCIS (Netherlands)

Marchand, M.; Ludwig, F.

2014-01-01

Deltas are dynamic landforms at the boundary of land and sea, involving intricate mazes of rivers and small waterways, wetlands, estuaries and coastal barrier islands. They are home to over half a billion people. Deltas are also home to rich ecosystems, such as mangroves and marshes. They are

Conservative Delta Hedging

Science.gov (United States)

1997-09-01

an exact method for converting such intervals into arbitrage based prices of financial derivatives or industrial or contractual options. We call this...procedure conservative delta hedging . As existing procedures are of an ad hoc nature, the proposed approach will permit an institution’s man agement a greater oversight of its exposure to risk.

Sedimentation patterns in floodplains of the Mekong Delta - Vietnam

Science.gov (United States)

Van Manh, Nguyen; Merz, Bruno; Viet Dung, Nguyen; Apel, Heiko

2013-04-01

Quantification of floodplain sedimentation during the flood season in the Mekong Delta (MD) plays a very important role in the assessment of flood deposits for a sustainable agro-economic development. Recent studies on floodplain sedimentation in the region are restricted to small pilot sites because of the large extend of the Delta, and the complex channel. This research aims at a quantification of the sediment deposition in floodplains of the whole Mekong Delta, and to access the impacts of the upstream basin development on the sedimentation in the Delta quantitatively. To achieve this, a suspended sediment transport model is developed based on the quasi-2D hydrodynamic model of the whole Mekong Delta developed by Dung et al. (2011). The model is calibrated and validated using observed data derived from several sediment measurement campaigns in channel networks and floodplains. Measured sediment data and hydrodynamic model quantify the spatio-temporal variability of sediment depositions in different spatial units: individual dyke compartments, and the sub-regions Plain of Reeds, Long Xuyen Quadrangle and the area between Tien River and Hau River. It is shown that the distribution of sediment deposition over the delta is highly depended on the flood magnitude, that in turn drives the operation policy of flood control systems in floodplains of the Mekong Delta. Thus, the sedimentation distribution is influenced by the protection level of the dyke systems in place and the distance to the Tien River and Hau River, the main branches of the Mekong in the Delta. This corroborates the main findings derived from data analysis obtained from a small scale test site by Hung et al, (2011, 2012a). Moreover, the results obtained here underlines the importance of the main channels for the sediment transport into the floodplains, and the deposition rate in floodplains is strongly driven by the intake locations and the distance from these to the main channels as well.

Redox thermodynamics of the native and alkaline forms of eukaryotic and bacterial class I cytochromes c.

Science.gov (United States)

Battistuzzi, G; Borsari, M; Sola, M; Francia, F

1997-12-23

The reduction potentials of beef heart cytochrome c and cytochromes c2 from Rhodopseudomonas palustris, Rhodobacter sphaeroides, and Rhodobacter capsulatus were measured through direct electrochemistry at a surface-modified gold electrode as a function of temperature in nonisothermal experiments carried out at neutral and alkaline pH values. The thermodynamic parameters for protein reduction (DeltaS degrees rc and DeltaH degrees rc) were determined for the native and alkaline conformers. Enthalpy and entropy terms underlying species-dependent differences in E degrees and pH- and temperature-induced E degrees changes for a given cytochrome were analyzed. The difference of about +0.1 V in E degrees between cytochromes c2 and the eukaryotic species can be separated into an enthalpic term (-DeltaDeltaH degrees rc/F) of +0.130 V and an entropic term (TDeltaDeltaS degrees rc/F) of -0.040 V. Hence, the higher potential of the bacterial species appears to be determined entirely by a greater enthalpic stabilization of the reduced state. Analogously, the much lower potential of the alkaline conformer(s) as compared to the native species is by far enthalpic in origin for both protein families, and is largely determined by the substitution of Met for Lys in axial heme ligation. Instead, the biphasic E degrees /temperature profile for the native cytochromes is due to a difference in reduction entropy between the conformers at low and high temperatures. Temperature-dependent 1H NMR experiments suggest that the temperature-induced transition also involves a change in orientation of the axial methionine ligand with respect to the heme plane.

Thermostatted delta f

International Nuclear Information System (INIS)

Krommes, J.A.

2000-01-01

The delta f simulation method is revisited. Statistical coarse-graining is used to rigorously derive the equation for the fluctuation delta f in the particle distribution. It is argued that completely collisionless simulation is incompatible with the achievement of true statistically steady states with nonzero turbulent fluxes because the variance of the particle weights w grows with time. To ensure such steady states, it is shown that for dynamically collisionless situations a generalized thermostat or W-stat may be used in lieu of a full collision operator to absorb the flow of entropy to unresolved fine scales in velocity space. The simplest W-stat can be implemented as a self-consistently determined, time-dependent damping applied to w. A precise kinematic analogy to thermostatted nonequilibrium molecular dynamics (NEMD) is pointed out, and the justification of W-stats for simulations of turbulence is discussed. An extrapolation procedure is proposed such that the long-time, steady-state, collisionless flux can be deduced from several short W-statted runs with large effective collisionality, and a numerical demonstration is given

CAPITALISATION OF NATURAL RESOURCES FOR TOURISM PURPOSES IN THE DANUBE DELTA

Directory of Open Access Journals (Sweden)

IOAN ILDIKO

2015-06-01

Full Text Available The Danube Delta outstands by a number of characteristics that outline its uniquiness at national, regional and world level, pattern that is recognized by its multiple natural reserve status (biosphere reserve, Ramsar site, UNESCO natural heritage site, Natura 2000 site. Despite major technical works that were prior performed for the development of transportation, agriculture, and mining in the Danube Delta, the territory still preserves untamed ecosystems that create breath-taking landscapes and allow a powerful transformative experience of wilderness with major sustainability education potential for its visitors. Meanwhile, traditional economic activities are declining and local communities are experiencing mainly the drawbacks of remoteness instead of harnessing the valuable opportunities born within the current economic trends that emphasize the need to capture the positive externalities of well-preserved natural ecosystems. The Danube Delta is already a well-known tourism destination, but this status still fails to improve local wellbeing. Thus the richness of natural resources is conflicting with the wellbeing of communities with most of the people living at the edge of poverty. This “resource curse” like situation is the main reason that motivates our study that envisages outlining how tourism development and management could create the economic capacity that delivers prosperity for local communities without jeopardising the conservation goals of the natural reserve. In this respect we revisited a number of characteristics of tourism potential, tourism indicators, patterns of tourism products, and the current tourism management. This analysis revealed that there are a number of positive trends, but also the need to strengthen the measures that support high value added tourism products that allow avoiding the threat of numerous visitors and the development of mass tourism infrastructure. The relevance of these conclusions is limited by

Parametrization of the. delta. residue function. [Complex functions

Energy Technology Data Exchange (ETDEWEB)

Vasan, S S [Carnegie-Mellon Univ., Pittsburgh, Pa. (USA). Dept. of Physics

1976-04-19

The complex residues at the ..delta..(1236) and ..delta..(1950) poles in the relevant partial-wave amplitudes provide information on the behaviour of the ..delta.. Regge residue function in the resonance region u>0. Attempts to incorporate this information in parametrizations of the residue by functions that are real on the real u-axis result in residues which have unsatisfactory behaviour in the region u<1GeV/sup 2/. The choice of complex functions for the trajectory and residue removes this undesirable feature and provides a better representation of the residue in the resonance region, suggesting that complex parametrizations would be better suited to Regge analyses of near-backward scattering.

Ratio of deuterium to hydrogen in interstellar space. IV. The lines of sight to delta, epsilon, and iota Orionis

International Nuclear Information System (INIS)

Laurent, C.; Vidal-Madjar, A.; York, D.G.

1979-01-01

We have analyzed the deuterium absorption features in the spectra of delta, epsilon, and iota Ori obtained with Copernicus. The iota Ori line-of-sight analysis, which is quite detailed because of the high-velocity H I components superposed on the deuterium features, gives a D/H ratio (which is uncertain because of a complex profile) of 1.4 x 10 -5 . We determined a D/H ratio of the order of 7 x 10 -6 for delta and epsilon Ori. For the complex line profiles involved, one may regard this as a formal lower limit. Several attempts were made to increase the ratio N (DI)/N (H I) in the context of reasonable models for the line of sight, but with no success; we therefore regard the derived values as actual values, not lower limits. Since our derived value is an average on the line of sight, we cannot rule out the possibility that the true ratios N (D I)/N (H I) in individual nearby components (Δν -1 ) differ from the mean values. Our mean value for these two directions is lower by a factor of 4 than our best value for the zeta Pup line of sight

Central Delta languages: An overview | Kari | Stellenbosch Papers ...

African Journals Online (AJOL)

This paper presents an overview of the phonology, morphology and syntax of Central Delta languages. It also provides information on the geo-linguistic, demographic and sociolinguistic situation of these languages. It notes that Central Delta languages have a 20-vowel system, which divides into two sets of 10 vowels ...

Topological Mappings via B&delta;g-Closed Sets

OpenAIRE

Maruthamuthu, Raja; Narayanasamy, Seenivasagan; Otchanathevar, Ravi

2018-01-01

In this paper we introduce a new class of functions called  B&delta;g-continuous functions. We obtain several characterizations and some their properties. Also we investigate its relationship with other types of functions. Further we introduce and study a new class of functions namely B&delta;g-irresolute.

Sand transport, shear stress, and the building of a delta

Science.gov (United States)

Wagner, W.; Miller, K. L.; Hiatt, M. R.; Mohrig, D. C.

2017-12-01

River deltas distribute sediment to the coastal sea through a complex branching network of channels; however, the routing and storage of this sediment in and through the delta is poorly understood. We present results from field studies of the sediment and water transport through the branching Wax Lake Delta on the coast of Louisiana. Two channels studied, Main Pass and East Pass, maintain a near-equal total partitioning of flow and sediment. However, East Pass is narrower and has higher river velocities, lower tidal velocity fluctuations, less alluvial bed cover, and more sediment flux per unit width than Main Pass. We connect these differences to small differences in the geometry of the two channels and feedbacks between these differences. We link trends in measured sediment deposits to both measured and modeled shear velocities in Wax Lake Delta's channels and open water `islands' to understand how hydrologic processes shaped the sedimentary architecture of the delta. These connections define the sediment transport and deposition regimes in the WLD. We extend the results herein to suggest that the relationships between the available sediment and shear stress determines the basic planform of the Wax Lake Delta and cross-sectional geometries of its channels.

Preparing the Dutch delta for future droughts: model based support in the national Delta Programme

Science.gov (United States)

ter Maat, Judith; Haasnoot, Marjolijn; van der Vat, Marnix; Hunink, Joachim; Prinsen, Geert; Visser, Martijn

2014-05-01

changing conditions. The plan commits to short term actions, and identifies signpost indicators and trigger values to assess if next actions of the identified policy pathways need to be implemented or if reassessment of the plan is needed. For example, river discharges could be measured to monitor changes in low discharges as a result of climate change, and assess whether policy options such as diverting more water the main fresh water lake (IJsselmeer) need to be implemented sooner or later or not at all. The adaptive plan of the Delta Programme will be presented in 2014. First lessons of this part of the Delta Programme can already be drawn: Both the complex and meta-model had its own purpose in each phase. The meta-model was particularly useful for identifying promising policy options and for consultation of stakeholders due to the instant response. The complex model had much more opportunities to assess impacts of regional policy actions, and was supported by regional stakeholders that recognized their areas better in this model. Different sector impact assessment modules are also included in the workflow of the complex model. However, the complex model has a long runtime (i.e. three days for 1 year simulation or more than 100 days for 35 year time series simulation), which makes it less suitable to support the dynamic policy process on instant demand and interactively.

A Novel Sigma-Delta Modulator with Fractional-Order Digital Loop Integrator

Directory of Open Access Journals (Sweden)

Chi Xu

2017-01-01

Full Text Available This paper proposes using a fractional-order digital loop integrator to improve the robust stability of Sigma-Delta modulator, thus extending the integer-order Sigma-Delta modulator to a non-integer-order (fractional-order one in the Sigma-Delta ADC design field. The proposed fractional-order Sigma-Delta modulator has reasonable noise characteristics, dynamic range, and bandwidth; moreover the signal-to-noise ratio (SNR is improved remarkably. In particular, a 2nd-order digital loop integrator and a digital PIλDμ controller are combined to work as the fractional-order digital loop integrator, which is realized using FPGA; this will reduce the ASIC analog circuit layout design and chip testing difficulties. The parameters of the proposed fractional-order Sigma-Delta modulator are tuned by using swarm intelligent algorithm, which offers opportunity to simplify the process of tuning parameters and further improve the noise performance. Simulation results are given and they demonstrate the efficiency of the proposed fractional-order Sigma-Delta modulator.

Non-self-sustained electric discharge in oxygen gas mixtures: singlet delta oxygen production

CERN Document Server

Ionin, A A; Kotkov, A A; Kochetov, I V; Napartovich, A P; Seleznev, L V; Sinitsyn, D V; Hager, G D

2003-01-01

The possibility of obtaining a high specific input energy in an electron-beam sustained discharge ignited in oxygen gas mixtures O sub 2 : Ar : CO (or H sub 2) at the total gas pressures of 10-100 Torr was experimentally demonstrated. The specific input energy per molecular component exceeded approx 6 kJ l sup - sup 1 atm sup - sup 1 (150 kJ mol sup - sup 1) as a small amount of carbon monoxide was added into a gas mixture of oxygen and argon. It was theoretically demonstrated that one might expect to obtain a singlet delta oxygen yield of 25% exceeding its threshold value needed for an oxygen-iodine laser operation at room temperature, when maintaining a non-self-sustained discharge in oxygen gas mixtures with molecular additives CO, H sub 2 or D sub 2. The efficiency of singlet delta oxygen production can be as high as 40%.

Challenges and Approaches in River Delta Planning - Annexes to report on training workshop

NARCIS (Netherlands)

Wosten, J.H.M.; Douven, W.; Long Phi, H.; Fida Abdullah Khan, M.

2012-01-01

Programme, participants and all powerpoint presentations of the Delta Alliance Training Workshop: Challenges and approaches in river delta planning, sharing experiences from SE Asian Deltas and the Rhine-Meuse Delta. 22-26 October 2012, WACC, Vietnam National University, Ho Chi Minh City, Vietnam

Laser ablation-combustion-GC-IRMS--a new method for online analysis of intra-annual variation of delta13C in tree rings.

Science.gov (United States)

Schulze, Brigit; Wirth, Christian; Linke, Petra; Brand, Willi A; Kuhlmann, Iris; Horna, Viviana; Schulze, Ernst-Detlef

2004-11-01

We present a new, rapid method for high-resolution online determination of delta13C in tree rings, combining laser ablation (LA), combustion (C), gas chromatography (GC) and isotope ratio mass spectrometry (IRMS) (LA-C-GC-IRMS). Sample material was extracted every 6 min with a UV-laser from a tree core, leaving 40-microm-wide holes. Ablated wood dust was combusted to CO2 at 700 degrees C, separated from other gases on a GC column and injected into an isotope ratio mass spectrometer after removal of water vapor. The measurements were calibrated against an internal and an external standard. The tree core remained intact and could be used for subsequent dendrochronological and dendrochemical analyses. Cores from two Scots pine trees (Pinus sylvestris spp. sibirica Lebed.) from central Siberia were sampled. Inter- and intra-annual patterns of delta13C in whole-wood and lignin-extracted cores were indistinguishable apart from a constant offset, suggesting that lignin extraction is unnecessary for our method. Comparison with the conventional method (microtome slicing, elemental analysis and IRMS) indicated high accuracy of the LA-C-GC-IRMS measurements. Patterns of delta13C along three parallel ablation lines on the same core showed high congruence. A conservative estimate of the precision was +/- 0.24 per thousand. Isotopic patterns of the two Scots pine trees were broadly similar, indicating a signal related to the forest stand's climate history. The maximum variation in delta13C over 22 years was about 5 per thousand, ranging from -27 to -22.3 per thousand. The most obvious pattern was a sharp decline in delta13C during latewood formation and a rapid increase with spring early growth. We conclude that the LA-C-GC-IRMS method will be useful in elucidating short-term climate effects on the delta13C signal in tree rings.

Degree-degree correlations in random graphs with heavy-tailed degrees

NARCIS (Netherlands)

Hofstad, van der R.W.; Litvak, N.

2014-01-01

Mixing patterns in large self-organizing networks, such as the Internet, the World Wide Web, social, and biological networks are often characterized by degree-degree dependencies between neighboring nodes. In assortative networks, the degree-degree dependencies are positive (nodes with similar

Degree-Degree Dependencies in Random Graphs with Heavy-Tailed Degrees

NARCIS (Netherlands)

van der Hofstad, Remco; Litvak, Nelly

2014-01-01

Mixing patterns in large self-organizing networks, such as the Internet, the World Wide Web, social, and biological networks are often characterized by degree-degree dependencies between neighboring nodes. In assortative networks, the degree-degree dependencies are positive (nodes with similar

Adaptive delta management: a comparison between the Netherlands and Bangladesh Delta Program

NARCIS (Netherlands)

Zevenbergen, Chris; Khan, Shah Alam; Alphen, van Jos; Terwisscha van Scheltinga, Catharien; Veerbeek, William

2018-01-01

In the Netherlands, the central government, water authorities, provinces and municipalities are working together on a new Delta Program on Flood Risk Management and Fresh Water Supply (DP). Its primary goal is to protect the Netherlands against floods and ensure the availability of fresh water, now

Cohesive Sedimentary Processes on River-Dominated Deltas: New Perspectives from the Mississippi River Delta Front, Gulf of Mexico

Science.gov (United States)

Bentley, S. J.; Keller, G. P.; Obelcz, J.; Maloney, J. M.; Xu, K.; Georgiou, I. Y.; Miner, M. D.

2016-12-01

On river deltas dominated by proximal sediment accumulation (Mississippi, Huang He, others), the delta front region is commonly dominated by rapid accumulation of cohesive fluvial sediments, and mass-wasting processes that remobilize recently deposited sediments. Mass transport is preconditioned in sediments by high water content, biogenic gas production, over steepening, and is commonly triggered by strong wave loading and other processes. This understanding is based on extensive field studies in the 1970's and 80's. Recent studies of the Mississippi River Delta Front are yielding new perspectives on these processes, in a time of anthropogenically reduced sediment loads, rising sea level, and catastrophic deltaic land loss. We have synthesized many industry data sets collected since ca. 1980, and conducted new pilot field and modeling studies of sedimentary and morphodynamic processes. These efforts have yielded several key findings that diverge from historical understanding of this dynamic setting. First, delta distributary mouths have ceased seaward progradation, ending patterns that have been documented since the 18th century. Second, despite reduced sediment supply, offshore mass transport continues, yielding vertical displacements at rates of 1 m/y. This displacement is apparently forced by wave loading from storm events of near-annual return period, rather than major hurricanes that have been the focus of most previous studies. Third, core analysis indicates that this vertical displacement is occurring along failure planes >3 m in the seabed, rather than in more recently deposited sediments closer to the sediment-water interface. These seabed morphodynamics have the potential to destabilize both nearshore navigation infrastructure, and seabed hydrocarbon infrastructure offshore. As well, these findings raise more questions regarding the future seabed evolution offshore of major river deltas, in response to anthropogenic and climatic forcing.

Grain-size sorting in grainflows at the lee side of deltas

NARCIS (Netherlands)

Kleinhans, M.G.

2005-01-01

The sorting of sediment mixtures at the lee slope of deltas (at the angle of repose) is studied with experiments in a narrow, deep flume with subaqueous Gilbert-type deltas using varied flow conditions and different sediment mixtures. Sediment deposition and sorting on the lee slope of the delta

Governance of ‘long term delta planning’ in Bangladesh, Vietnam and the Netherlands

NARCIS (Netherlands)

Staveren, van M.F.

2014-01-01

The Deltas in Times of Climate Change Conference II, taking place in September 2014, Rotterdam, presented a suitable occasion to discuss both delta challenges and interesting approaches to how ‘delta dynamics’ are being dealt with worldwide.1 Delta dynamics include here both environmental (including

Structure of the [delta]-opioid receptor bound to naltrindole

Energy Technology Data Exchange (ETDEWEB)

Granier, Sébastien; Manglik, Aashish; Kruse, Andrew C.; Kobilka, Tong Sun; Thian, Foon Sun; Weis, William I.; Kobilka, Brian K. (Stanford-MED)

2012-07-11

The opioid receptor family comprises three members, the {mu}-, {delta}- and {kappa}-opioid receptors, which respond to classical opioid alkaloids such as morphine and heroin as well as to endogenous peptide ligands like endorphins. They belong to the G-protein-coupled receptor (GPCR) superfamily, and are excellent therapeutic targets for pain control. The {delta}-opioid receptor ({delta}-OR) has a role in analgesia, as well as in other neurological functions that remain poorly understood. The structures of the {mu}-OR and {kappa}-OR have recently been solved. Here we report the crystal structure of the mouse {delta}-OR, bound to the subtype-selective antagonist naltrindole. Together with the structures of the {mu}-OR and {kappa}-OR, the {delta}-OR structure provides insights into conserved elements of opioid ligand recognition while also revealing structural features associated with ligand-subtype selectivity. The binding pocket of opioid receptors can be divided into two distinct regions. Whereas the lower part of this pocket is highly conserved among opioid receptors, the upper part contains divergent residues that confer subtype selectivity. This provides a structural explanation and validation for the 'message-address' model of opioid receptor pharmacology, in which distinct 'message' (efficacy) and 'address' (selectivity) determinants are contained within a single ligand. Comparison of the address region of the {delta}-OR with other GPCRs reveals that this structural organization may be a more general phenomenon, extending to other GPCR families as well.

The North Atlantic marine reservoir effect in the Early Holocene: Implications for defining and understanding MRE values

Energy Technology Data Exchange (ETDEWEB)

Ascough, P.L. [School of Geography and Geosciences, Irvine Building, University of St. Andrews, St. Andrews, Fife KY16 9AL (United Kingdom)]. E-mail: pla1@st-andrews.ac.uk; Cook, G.T. [Scottish Universities Environmental Research Centre, Scottish Enterprise Technology Park, Rankine Avenue, East Kilbride G75 OQF (United Kingdom); Dugmore, A.J. [Institute of Geography, School of GeoSciences, University of Edinburgh, Edinburgh EH8 9XP (United Kingdom); Scott, E.M. [Department of Statistics, University of Glasgow, Glasgow G12 8QQ (United Kingdom)

2007-06-15

The marine reservoir effect (MRE) is a {sup 14}C age offset between the oceanic and atmospheric carbon reservoirs. The MRE is neither spatially nor temporally constant and values may deviate significantly from the global model average provided by the Marine04 curve. Such a deviation is calculated as a {delta}R value and modern (pre-bomb) values show considerable spatial variations. There is also considerable evidence for temporal variability linked to paleoenvironmental changes identified in paleoclimatic proxy records. Seven new {delta}R values are presented for the North Atlantic, relating to the period c. 8430-3890 cal. BP (c. 6480-1940 BC). These were obtained from {sup 14}C analysis of multiple samples of terrestrial and marine material derived from seven individual archaeological deposits from Mainland Scotland, the Outer Hebrides and the Orkney Isles. The {delta}R values vary between 143 {+-} 20 {sup 14}C yr and -100 {+-} 15 {sup 14}C yr with the positive values all occurring in the earlier period (8430-5060 cal. BP), and the negative values all coming from later deposits (4820-3890 cal. BP). The nature of MRE values and the potential for spatial and temporal variation in values is the subject of current research interest and these data are placed in the context of (i) other estimates for UK coastal waters and (ii) important questions concerning current approaches to quantifying the MRE.

Spatial structure determination of ({radical}3 x {radical}3)R30{degrees} and (1.5 x 1.5)R18{degrees}CO on Cu(111) using angle-resolved photoemission extended fine structure

Energy Technology Data Exchange (ETDEWEB)

Moler, E.J.; Kellar, S.A.; Huff, W.R.A. [Lawrence Berkeley National Lab., CA (United States)] [and others

1997-04-01

The authors report a study of the spatial structure of ({radical}3 x {radical}3)R30{degrees} (low coverage) and (1.5 x 1.5)R18{degrees} (intermediate coverage) CO adsorbed on Cu(111), using the Angle-Resolved Photoemission Extended Fine Structure (ARPEFS) technique at beamline 9.3.2 at the Advanced Light Source. The CO molecule adsorbs on an atop site for both adsorption phases. Full multiple-scattering spherical-wave (MSSW) calculations were used to extract the C-Cu. bond length and the first Cu-Cu layer spacing for each adsorption phase. The authors find that the C-Cu bond length remains unchanged with increasing coverage, but the 1st Cu-Cu layer spacing contracts at the intermediate coverage. They calculate the bending mode force constant in the (1.5 x 1.5)R18{degrees} phase to be K{sub {delta}} = 2.2 (1) x 10{sup {minus}12} dyne-cm/rad from their experimentally determined bond lengths combined with previously published infra-red absorption frequencies.

T-cell receptor gamma delta bearing cells in normal human skin

NARCIS (Netherlands)

Bos, J. D.; Teunissen, M. B.; Cairo, I.; Krieg, S. R.; Kapsenberg, M. L.; Das, P. K.; Borst, J.

1990-01-01

T-cell antigen receptors (TCR) are divided into common alpha beta and less common gamma delta types. In the murine skin, TCR gamma delta+ cells have been reported to form the great majority of epidermal T lymphocytes. We have examined the relative contribution of TCR alpha beta+ and TCR gamma delta+

Real And Reactive Power Saving In Three Phase Induction Machine Using Star-Delta Switching Schemes

Directory of Open Access Journals (Sweden)

Ramesh Daravath

2017-04-01

Full Text Available Induction machines are the most commonly used industrial drives for variety of applications. It has been estimated that induction motors consumes approximately 50 of all the electric energy generated. Further in the area of renewable energy sources such as wind or bio-mass energy induction machines have been found suitable for functioning as generators. In this context it may be mentioned that a star-delta switching is common for the starting of three-phase induction motor. Now it is proposed to use this star-delta switching for energy conservation of induction machines i.e. at times of reduced loads the machine switched back to star connection. Using a three-phase 400 V 50 Hz 4-pole induction machine it has been demonstrated that the star-delta switching of stator winding of three-phase induction machine motor generator operations reconnected in star at suitable reduced loads with a switching arrangement can result in improved efficiency and power factor as compared to a fixed delta or star connection. The predetermined values along with the experimental results have also been presented in this report. A simulation program has been developed for the predetermination of performance of the three-phase induction machine using exact equivalent circuit. A case study on a 250 kW 400 V 4-pole three-phase induction machine operated with different load cycles reveals the significant real and reactive power savings that could be obtained in the present proposal.

Effect of external stores on the stability and control characteristics of a delta wing fighter model at Mach numbers from 0.60 to 2.01

Science.gov (United States)

Spearman, M. L.

1983-01-01

An investigation has been made to determine the effects of external stores on the stability and control characteristics of a delta wing fighter airplane model at Mach numbers from 0.60 to 2.01 for a Reynolds number of 3.0 X 1 million per foot. The angle-of-attack range was from about -4 degrees to 20 degrees at a sideslip angle of 0 degrees for the transonic tests, and from about -4 degrees to 10 degrees at sideslip angles of 0 degrees and 3 degrees for the supersonic tests. In general, the results of the tests indicated no seriously detrimental effects of the stores on the stability and control characteristics of the model but did show an increase in the minimum drag level throughout the Mach number range. However, the drag-due-to-lift was such that for subsonic/transonic speeds, the drag at higher lifts was essentially unaffected and the indications are that the maneuvering capability may not be impaired by the stores.

Thermochemical properties of gibbsite, bayerite, boehmite, diaspore, and the aluminate ion between 0 and 350/degree/C

Energy Technology Data Exchange (ETDEWEB)

Apps, J.A.; Neil, J.M.; Jun, C.H.

1989-01-01

A requirement for modelling the chemical behavior of groundwater in a nuclear waste repository is accurate thermodynamic data pertaining to the participating minerals and aqueous species. In particular, it is important that the thermodynamic properties of the aluminate ion be accurately determined, because most rock forming minerals in the earth's crust are aluminosilicates, and most groundwaters are neutral to slightly alkaline, where the aluminate ion is the predominant aluminum species in solution. Without a precise knowledge of the thermodynamic properties of the aluminate ion aluminosilicate mineral solubilities cannot be determined. The thermochemical properties of the aluminate ion have been determined from the solubilities of the aluminum hydroxides and oxyhydroxides in alkaline solutions between 20 and 350/degree/C. An internally consistent set of thermodynamic properties have been determined for gibbsite, boehmite, diaspore and corundum. The thermodynamic properties of bayerite have been provisionally estimated and a preliminary value for ..delta..G/sub f, 298//sup 0/ of nordstrandite has been determined. 205 refs., 17 figs., 25 tabs.

Hole states in diamond p-delta-doped field effect transistors

International Nuclear Information System (INIS)

Martinez-Orozco, J C; Rodriguez-Vargas, I; Mora-Ramos, M E

2009-01-01

The p-delta-doping in diamond allows to create high density two-dimensional hole gases. This technique has already been applied in the design and fabrication of diamond-based field effect transistors. Consequently, the knowledge of the electronic structure is of significant importance to understand the transport properties of diamond p-delta-doped systems. In this work the hole subbands of diamond p-type delta-doped quantum wells are studied within the framework of a local-density Thomas-Fermi-based approach for the band bending profile. The calculation incorporates an independent three-hole-band scheme and considers the effects of the contact potential, the delta-channel to contact distance, and the ionized impurity density.

Hole states in diamond p-delta-doped field effect transistors

Energy Technology Data Exchange (ETDEWEB)

Martinez-Orozco, J C; Rodriguez-Vargas, I [Unidad Academica de Fisica, Universidad Autonoma de Zacatecas, Calzada Solidaridad Esquina con Paseo la Bufa S/N, CP 98060 Zacatecas, ZAC. (Mexico); Mora-Ramos, M E, E-mail: jcmover@correo.unam.m [Facultad de Ciencias, Universidad Autonoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, CP 62209 Cuernavaca, MOR. (Mexico)

2009-05-01

The p-delta-doping in diamond allows to create high density two-dimensional hole gases. This technique has already been applied in the design and fabrication of diamond-based field effect transistors. Consequently, the knowledge of the electronic structure is of significant importance to understand the transport properties of diamond p-delta-doped systems. In this work the hole subbands of diamond p-type delta-doped quantum wells are studied within the framework of a local-density Thomas-Fermi-based approach for the band bending profile. The calculation incorporates an independent three-hole-band scheme and considers the effects of the contact potential, the delta-channel to contact distance, and the ionized impurity density.

7 CFR 29.3586 - Elements of quality and degrees of each element.

Science.gov (United States)

2010-01-01

... value, but the actual value of each degree varies with type, group, and grade. Elements Degrees Maturity.... Elasticity Inelastic Semielastic Elastic. Width Narrow Normal Spready. Uniformity (1) (1) (1). Injury...

Linking rapid erosion of the Mekong River delta to human activities.

Science.gov (United States)

Anthony, Edward J; Brunier, Guillaume; Besset, Manon; Goichot, Marc; Dussouillez, Philippe; Nguyen, Van Lap

2015-10-08

As international concern for the survival of deltas grows, the Mekong River delta, the world's third largest delta, densely populated, considered as Southeast Asia's most important food basket, and rich in biodiversity at the world scale, is also increasingly affected by human activities and exposed to subsidence and coastal erosion. Several dams have been constructed upstream of the delta and many more are now planned. We quantify from high-resolution SPOT 5 satellite images large-scale shoreline erosion and land loss between 2003 and 2012 that now affect over 50% of the once strongly advancing >600 km-long delta shoreline. Erosion, with no identified change in the river's discharge and in wave and wind conditions over this recent period, is consistent with: (1) a reported significant decrease in coastal surface suspended sediment from the Mekong that may be linked to dam retention of its sediment, (2) large-scale commercial sand mining in the river and delta channels, and (3) subsidence due to groundwater extraction. Shoreline erosion is already responsible for displacement of coastal populations. It is an additional hazard to the integrity of this Asian mega delta now considered particularly vulnerable to accelerated subsidence and sea-level rise, and will be exacerbated by future hydropower dams.

DELTA-5-ANDROSTENEDIOL AND ITS SULFATE IN SERUM AND URINE OF NORMAL ADULTS AND PATIENTS WITH ENDOCRINE DISEASES

NARCIS (Netherlands)

DIKKESCHEI, LD; WILLEMSE, PHB; WOLTHERS, BG; DERUYTERBUITENHUIS, AW; NAGEL, GT

1993-01-01

OBJECTIVES We evaluated the role of delta-5-androstenediol (adiol) and its sulphates in health and endocrine diseases. DESIGN Serum and urine samples from healthy adult men and pre and post-menopausal women were analysed by gas chromatography-mass spectrometry to establish reference values. In

The Top 100: Graduate Degrees Conferred

Science.gov (United States)

Borden, Victor M. H.

2011-01-01

Recently, some critics and policymakers have started to question the value of a college education given the increasing costs of attending and the commensurate high debt levels of college graduates. Past and present studies also demonstrate that the average value masks important variation by degree level and field of study. This paper focuses on…

Plant delta 15N correlates with the transpiration efficiency of nitrogen acquisition in tropical trees.

Science.gov (United States)

Cernusak, Lucas A; Winter, Klaus; Turner, Benjamin L

2009-11-01

Based upon considerations of a theoretical model of (15)N/(14)N fractionation during steady-state nitrate uptake from soil, we hypothesized that, for plants grown in a common soil environment, whole-plant delta(15)N (deltaP) should vary as a function of the transpiration efficiency of nitrogen acquisition (F(N)/v) and the difference between deltaP and root delta(15)N (deltaP - deltaR). We tested these hypotheses with measurements of several tropical tree and liana species. Consistent with theoretical expectations, both F(N)/v and deltaP - deltaR were significant sources of variation in deltaP, and the relationship between deltaP and F(N)/v differed between non-N(2)-fixing and N(2)-fixing species. We interpret the correlation between deltaP and F(N)/v as resulting from variation in mineral nitrogen efflux-to-influx ratios across plasma membranes of root cells. These results provide a simple explanation of variation in delta(15)N of terrestrial plants and have implications for understanding nitrogen cycling in ecosystems.

Frontal delta-beta cross-frequency coupling in high and low social anxiety: An index of stress regulation?

Science.gov (United States)

Poppelaars, Eefje S; Harrewijn, Anita; Westenberg, P Michiel; van der Molen, Melle J W

2018-05-17

Cross-frequency coupling (CFC) between frontal delta (1-4 Hz) and beta (14-30 Hz) oscillations has been suggested as a candidate neural correlate of social anxiety disorder, a disorder characterized by fear and avoidance of social and performance situations. Prior studies have used amplitude-amplitude correlation (AAC) as a CFC measure and hypothesized it as a candidate neural mechanism of affective control. However, using this metric has yielded inconsistent results regarding the direction of CFC, and the functional significance of coupling strength is uncertain. To offer a better understanding of CFC in social anxiety, we compared frontal delta-beta AAC with phase-amplitude coupling (PAC) - a mechanism for information transfer through neural circuits. Twenty high socially anxious (HSA) and 32 low socially anxious (LSA) female undergraduates participated in a social performance task (SPT). Delta-beta PAC and AAC were estimated during the resting state, as well as the anticipation and recovery conditions. Results showed significantly more AAC in LSA than HSA participants during early anticipation, as well as significant values during all conditions in LSA participants only. PAC did not distinguish between LSA and HSA participants, and instead was found to correlate with state nervousness during early anticipation, but in LSA participants only. Together, these findings are interpreted to suggest that delta-beta AAC is a plausible neurobiological index of adaptive stress regulation and can distinguish between trait high and low social anxiety during stress, while delta-beta PAC might be sensitive enough to reflect mild state anxiety in LSA participants.

Sustainability Efforts of One Oil Company in Niger Delta of Nigeria

Science.gov (United States)

Anosike, Charles Afam

Environmental degradation and socioeconomic dilemma continue to stigmatize oil production in the Niger Delta of Nigeria. Sustainability programs of oil companies often determine the improvement of living conditions in the region. This explanatory qualitative case study, guided by systems thinking theory and sustainable value framework, explored practitioners' perceptions of sustainability programs to identify its impact on business and the host communities. The research question was designed to address how sustainability efforts of a single oil company in the Niger Delta contributed to the business performance and the livelihood of the local people. Research data were gathered from a sample of 20 experienced sustainability practitioners of the oil company, partnering nonprofit organizations, and community leaders through face-to-face semistructured interviews. Data were segmented and categorized. The data analysis process revealed several themes regarding the challenges and shortfalls of sustainability programs in the region. The oil company's understanding of sustainability as programs and projects focused on preserving resources for future generations was not evident in practice. Findings from the study suggested the need for improved inclusiveness of people in driving sustainability projects. Inclusive sustainability should enhance the oil company's contemplation mechanism to ensure eco-saving thinking and processes, which could result in improved quality of life and business performance in the region. The research findings underscore the need for oil multinational corporations (MNCs) to use a business lens in viewing sustainability to achieve sustainable value.

Hydraulic model to assess the hydromorphological changes within the Danube Delta

Directory of Open Access Journals (Sweden)

CIOACĂ Eugenia

2012-09-01

Full Text Available Morphological changes of the hydrographic networks (rivers /channels /brooks /lakes as result of fluvial processes (erosion and alluvial sedimentation induce modification on hydrologic regime with positive /negative impacts on biodiversity. This paper aims at emphasizing the amplitude of these processes within the Danube Delta Biosphere Reserve (Romanian part inner hydrographic network, by means of the morphologic model, as maincomponent of 3D mathematical /hydraulic model. It is constructed based on geo-referenced database as resulted from hydraulicand bathymetric field measurements carried out within 2008-2010. Hydro-morphological changes are assessed by analyzingthose zones where fluvial processes have been identified to be active, meaning that specific hydraulic conditions are fulfilled,such as: water flow with high energy /high values of hydraulic parameters: level, speed, slope, and solid transport (upstream ofdelta: erosion followed by a decrease of these values (middle part: alluvia sedimentation and ending with very clear water at very low flow velocity (downstream of delta: no fluvial processes. Both erosion and, especially, alluvial sedimentation zones, in low water level conditions lead to disconnection of some channels /lakes generating ecological disequilibrium with negative impact on some flora and fauna species. Thus, the gained knowledge on the aquatic ecosystem function is used as scientific tool for decision making on a sound management of such an environment system in order to improve the quality of aquatic life by restoration of hydrographical network with impacts on habitats and overall ecological reconstruction.

Laboratory investigation on effects of flood intermittency on river delta dynamics

Science.gov (United States)

Miller, K. L.; Kim, W.

2015-12-01

In order to simplify the complex hydrological variability of flow conditions, experiments modeling delta evolution are often conducted using a representative "channel-forming" flood flow and then relate results to field settings using an intermittency factor, defined as the fraction of total time at flood conditions. Although this intermittency factor makes it easier to investigate how variables, such as relative base level and/or sediment supply, affect delta dynamics, little is known about how this generalization to a single flow condition affects delta processes. We conducted a set of laboratory experiments with periodic flow conditions to determine the effects of intermittent discharges on delta evolution. During the experiment, flood with a set water discharge and sediment supply, cycles between periods of normal flow where the water flux is halved and the sediment discharge is turned off. For each run, the magnitude of the flood is held constant, but the duration is assigned differently, thus varying the intermittency between 1 and 0.2. We find that as the intermittency factor decreases (duration of each flood period decreases), the delta topset has a larger, more elongated area with a shallower slope as a result of reworking on the delta topset during normal flow conditions. During periods of normal flow, the system adjusts towards a new equilibrium state that then in turn acts as the initial condition for the subsequent flood period. Furthermore, the natural delta avulsion cycle becomes obscured by the flood cycles as the flood duration becomes shorter than the autogenic behavior. These results suggest that the adjustment timescale for differing flow conditions is a factor in determining the overall shape of the delta and behavior of the fluviodeltaic channels. We conclude, periods of normal flow when topset sediment is reworked, may be just as important to delta dynamics as periods of flood when sediment is supplied to the system.

Characterization and Fate of Dissolved Organic Matter in the Lena Delta Region, Siberia

Science.gov (United States)

Goncalves-Araujo, R.; Stedmon, C. A.; Heim, B.; Dubinenkov, I.; Kraberg, A.; Moiseev, D.; Bracher, A.

2016-02-01

Connectivity between the terrestrial and marine environment in the Artic is changing as a result of climate change, influencing both freshwater budgets and the supply of carbon to the sea. This study characterizes the optical properties of dissolved organic matter (DOM) within the Lena Delta region and evaluates the behavior of DOM across the fresh water-marine gradient. Six fluorescent components (four humic-like; one marine humic-like; one protein-like) were identified by Parallel Factor Analysis (PARAFAC) with a clear dominance of allochthonous humic-like signals. Colored DOM (CDOM) and dissolved organic carbon (DOC) were highly correlated and had their distribution coupled with hydrographical conditions. Higher DOM concentration and degree of humification were associated with the low salinity waters of the Lena River. Values decreased towards the higher salinity Laptev Sea shelf waters. Results demonstrate different responses of DOM mixing in relation to the vertical structure of the water column, as reflecting the hydrographical dynamics in the region. Two mixing curves for DOM were apparent. In surface waters above the pycnocline there was a sharper decrease in DOM concentration in relation to salinity indicating removal. In the bottom water layer the DOM decrease within salinity was less. We propose there is a removal of DOM occurring primarily at the surface layer, which is likely driven by photodegradation and flocculation.

Plasticity of gamma delta T cells: impact on the anti-tumor response

Directory of Open Access Journals (Sweden)

Virginie eLafont

2014-12-01

Full Text Available The tumor immune microenvironment contributes to tumor initiation, progression and response to therapy. Among the immune cell subsets that play a role in the tumor microenvironment, innate-like T cells that express T cell receptors composed of gamma and delta chains (gamma delta T cells are of particular interest. gamma delta T cells can contribute to the immune response against many tumor types (lymphoma, myeloma, melanoma, breast, colon, lung, ovary and prostate cancer directly through their cytotoxic activity and indirectly by stimulating or regulating the biological functions of other cell types required for the initiation and establishment of the anti-tumor immune response, such as dendritic cells and cytotoxic CD8+ T cells. However, the notion that tumor-infiltrating gamma delta T cells are a good prognostic marker in cancer was recently challenged by studies showing that the presence of these cells in the tumor microenvironment was associated with poor prognosis in both breast and colon cancer. These findings suggest that gamma delta T cells may also display pro-tumor activities. Indeed, breast tumor-infiltrating gamma deltaT cells could exert an immunosuppressive activity by negatively regulating DC maturation. Furthermore, recent studies demonstrated that signals from the microenvironment, particularly cytokines, can confer some plasticity to gamma delta T cells and promote their differentiation into gamma delta T cells with regulatory functions. This review focuses on the current knowledge on the functional plasticity of gamma delta T cells and its effect on their anti-tumor activities. It also discusses the putative mechanisms underlying gamma delta T cell expansion, differentiation and recruitment in the tumor microenvironment.

Oil and Security in Nigeria: The Niger Delta Crisis | Owolabi | Africa ...

African Journals Online (AJOL)

This paper examines oil and security in Nigeria, with special reference to the crisis-ravaged Niger Delta. Its focus on the Niger Delta and its festering crisis stems from that region's critical importance to Nigeria. As the nation's treasure base, the Niger Delta provides over 80 percent of government revenues, 95 percent of ...

IMPACT STUDY OF ANISOTROPIC OPTICAL FIBERS WINDING WITH DIFFERENT TENSION VALUE ON THE H-PARAMETER INVARIANCE DEGREE

Directory of Open Access Journals (Sweden)

A. B. Mukhtubayev

2015-09-01

Full Text Available Subject of Research. We have investigated the effect of anisotropic optical fibers winding with an elliptical sheath subjecting to stress on the H-parameter invariance degree. This type of optical fiber is used in the manufacture of fiber loop in fiber-optic gyroscopes. Method of Research. The method of research is based on the application of Michelson polarization scanning interferometer as a measuring device. Superluminescent diode with a central wavelength of 1575 nm and a half-width of the spectrum equal to 45 nm is used as a radiation source. The studies were carried out with anisotropic optical fiber with 50 m long elliptical sheath subjecting to stress. The fiber was wound with one layer turn to turn on the coil with a diameter of 18 cm, which is used in the design of fiber-optic gyroscope. The tension force of the optical fiber was controlled during winding on a special machine. Main Results. It was found that at the increase of tension force from 0.05 N to 0.8 H the value of H-parameter increases from 7×10-6 1/m up to 178×10-6 1/m, respectively; i.e. the coupling coefficient of orthogonal modes in the test fiber is being increased. Thus, it is necessary to consider the longitudinal tension force of fiber in the design and manufacture of the fiber-optic sensors of high accuracy class: the less the fiber winding power, the higher invariance degree of distributed H-parameter. The longitudinal tension force of anisotropic optical fiber with elliptical sheath subjecting to stress equal to 0.2 N is recommended in the process of designing fiber-optic gyroscopes. Practical Relevance. The proposed method of Michelson scanning interferometer is usable in the production process for quality determination of the optical fiber winding: no local defects, value controlling of fiber H-parameter.

IMPACTS OF WETLAND DEGRADATION IN NIGER DELTA NIGERIA AND ITS SIGNIFICANCE IN FLOOD CONTROL

Directory of Open Access Journals (Sweden)

Enwere Chidimma Loveline

2015-08-01

Full Text Available  Wetlands perform a wide variety of functions that include flood control, ground water recharge, shore line stabilization, storm protection and climate moderation. However, despite these huge wetland functions, it has witnessed poor appreciation and dreadful conditions. Niger Delta has witnessed constant coastal erosion and rising sea level, this has led to large portions of the landmass being eroded. This paper aims to review some environmental effects of flooding in the Niger Delta region of Nigeria to provide the desired knowledge of role that wetlands play in reducing flood impacts. However, having witnessed the flood, the experience opened my eyes to the environmental challenges facing Niger Delta with respect to Wetlands degradation, poor perception of wetland values and functions, poor environmental practices and non-implementation of environmental regulations. This memorable experience rekindled the desire and motivation to seek a solution to wetland degradation with the aim of recognizing significance of wetlands at the centre of achieving both livelihood and biodiversity improvements to address coastal flooding problem.The study therefore concludes that wetlands are very significant in flood control and thus the conservation and restoration of wetlands, should put in place measures to reduce wetland destruction.International Journal of EnvironmentVolume-4, Issue-3, June-August 2015Page: 177-184

The ratio of deuterium to hydrogen in interstellar space. IV - The lines of sight to Delta, Epsilon, and Iota Orionis

Science.gov (United States)

Laurent, C.; Vidal-Madjar, A.; York, D. G.

1979-01-01

Deuterium absorption features in spectra of Delta, Epsilon, and Iota Ori obtained with Copernicus are analyzed. The Iota Ori line-of-sight analysis, which is quite detailed because of the high-velocity H I components superposed on the deuterium features, gives a D/H ratio (which is uncertain because of a complex profile) of 0.000014. A D/H ratio of the order of 7 millionths is determined for Delta and Epsilon Ori. For the complex line profiles involved, one may regard this as a formal lower limit. Several attempts were made to increase the ratio N(D I)/N(H I) in the context of reasonable models for the line of sight, but with no success; the derived values are therefore regarded as actual values, not lower limits. Since the derived value is an average on the line of sight, the possibility cannot be ruled out that the true ratios N(D I)/N(H I) in individual nearby components differ from the mean values. The mean value for these two directions is lower by a factor of 4 than the best value for the Zeta Pup line of sight (the highest yet derived for path lengths greater than 50 pc).

Peroxisome proliferator-activated receptor delta activation leads to increased transintestinal cholesterol efflux

NARCIS (Netherlands)

Vrins, Carlos L. J.; van der Velde, Astrid E.; van den Oever, Karin; Levels, Johannes H. M.; Huet, Stephane; Elferink, Ronald P. J. Oude; Kuipers, Folkert; Groen, Albert K.

2009-01-01

Peroxisome proliferator-activated receptor delta (PPAR delta) is involved in regulation of energy homeostasis. Activation of PPAR delta markedly increases fecal neutral sterol secretion, the last step in reverse cholesterol transport. This phenomenon can neither be explained by increased

Implementation of an ESA delta-DOR capability

Science.gov (United States)

James, Nick; Abello, Ricard; Lanucara, Marco; Mercolino, Mattia; Maddè, Roberto

2009-06-01

This paper describes the implementation of delta-DOR (delta-differential one-way ranging) receivers within the ESA Deep Space ground station network. Delta-DOR provides very accurate plane-of-sky measurements of spacecraft position which complement existing line-of-sight ranging and Doppler measurements. We discuss how this technique has been adapted and implemented at the two ESA deep-space ground stations using existing equipment and infrastructure. These new capabilities were added by writing new software modules for the standard ESA digital receiver (the intermediate frequency modem system—IFMS). With these upgrades the receiver has the ability to record accurately timetagged signals from up to eight IF sub-channels. These sub-channels can have bandwidths of 50 kHz-2 MHz with a sample quantization of 1-16 bits per component. The IF samples are stored locally for subsequent retrieval over a WAN by the correlator facility at ESOC.

Dynamic controls on shallow clinoform geometry: Mekong Delta, Vietnam

Science.gov (United States)

Eidam, E. F.; Nittrouer, C. A.; Ogston, A. S.; DeMaster, D. J.; Liu, J. P.; Nguyen, T. T.; Nguyen, T. N.

2017-09-01

Compound deltas, composed of a subaerial delta plain and subaqueous clinoform, are common termini of large rivers. The transition between clinoform topset and foreset, or subaqueous rollover point, is located at 25-40-m water depth for many large tide-dominated deltas; this depth is controlled by removal of sediment from the topset by waves, currents, and gravity flows. However, the Mekong Delta, which has been classified as a mixed-energy system, has a relatively shallow subaqueous rollover at 4-6-m depth. This study evaluates dynamical measurements and seabed cores collected in Sep 2014 and Mar 2015 to understand processes of sediment transfer across the subaqueous delta, and evaluate possible linkages to geometry. During the southwest rainy monsoon (Sep 2014), high river discharge, landward return flow under the river plume, and regional circulation patterns facilitated limited sediment flux to the topset and foreset, and promoted alongshore flux to the northeast. Net observed sediment fluxes in Sep 2014 were landward, however, consistent with hypotheses about seasonal storage on the topset. During the northeast rainy monsoon, low river discharge and wind-driven currents facilitated intense landward and southwestward fluxes of sediment. In both seasons, bed shear velocities frequently exceeded the 0.01-0.02 m/s threshold of motion for sand, even in the absence of strong wave energy. Most sediment transport occurred at water depths 4 cm/yr at energy-limited, and thus rollover depths cannot be predicted solely by bed-stress distributions. In systems like the subaqueous Mekong Delta, direction of transport may have a key impact on morphology.

A new identification method for energetic ion {delta}E-E telescopes

Energy Technology Data Exchange (ETDEWEB)

Martin, Cesar [Departamento de Fisica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain); Institut fuer Experimentelle und Angewandte Physik, Christian-Albrechts, Universitaet zu Kiel, 24118 Kiel (Germany); Bronchalo, Enrique [Departamento de Fisica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain); Departamento de Fisica y Arquitectura de Computadores, Universidad Miguel Hernandez, Avda. Universidad s/n, 03202 Elche, Alicante (Spain)], E-mail: ebronchalo@umh.es; Medina, Jose [Departamento de Fisica, Universidad de Alcala, 28871 Alcala de Henares, Madrid (Spain)

2007-11-21

A new ion identification method for {delta}E-E telescopes is presented. The method works by counting data points under {delta}E(E) curves on {delta}E-E diagrams. These curves are obtained by simulating the telescope response to a flux of energetic ions. The method is checked against three published methods applied to several experimental data sets.

Quaternary lacustrine braid deltas on Lake General Carrera in southern Chile Deltas entrelazados lacustres del Cuaternario en el lago General Carrera, sur de Chile

Directory of Open Access Journals (Sweden)

C. Mike Bell

2009-01-01

Full Text Available A series of Quaternary lacustrine braid deltas on the shores of Lake General Carrera in southern Chile formed as a result of falls in lake level. Each delta comprises two components, the delta fan and the beach embayment, each in turn comprising an onshore subaerial and an offshore subaqueous element. The delta fans have a classic Gilbert form with a braided delta top and a steeply inclined delta front. Adjacent to the fans are concave beach embayments that formed parallel with the deltas as they prograded into the lake. The delta sediments consist predominantly of matrix- and clast-supported gravéis to a total composite thickness exceeding 400 m. The depositional environments are dominated by ephemeral river flooding and by storm-driven waves. Beach sediment is sorted, rounded, winnowed and transported alongshore by waves to fill the beach embayment with ridges of very well sorted and well-rounded gravel. A gently-dipping shoreface platform occurs up to 100 m offshore between the beach and the brink point. From the brink point, in water depth of about 8 m, sediment cascades down the steep delta front slope to form long foresets extending to the lake floor. The sedimentary successions therefore wedge in the opposite direction from those of tectonically controlled basin margins where fan growth keeps pace with basin subsidence.Una serie de deltas entrelazados lacustres, pertenecientes al Cuaternario, ubicados en las costas del lago General Carrera, en el sur de Chile, se formaron como resultado de caídas en el nivel del lago. Cada delta consta de dos componentes: el abanico deltaico y la zona de embahiamiento. Cada uno de ellos tiene, a su vez, un elemento subaéreo costero y un elemento subacuático. Los abanicos deltaicos tienen una forma Gilbert clásica con una parte superior de ríos entrelazados y un frente deltaico empinado. Adyacente a los abanicos aluviales existen bahías cóncavas de playa que se formaron de manera paralela a los

Natural and Human-Induced Variations in Accretion of the Roanoke Bay-head Delta

Science.gov (United States)

Jalowska, A.; McKee, B. A.; Rodriguez, A. B.

2014-12-01

Bay-head deltas (BHD), along with their adjacent floodplains serve as storage sites for lithogenic and organic material on millennial time scales and are biogeochemically active sites on daily to decadal time scales, contributing to global nutrient and carbon cycles. BHD host unique, highly diverse ecosystems such as the pristine swamp forest and hardwood bottomlands, of the Lower Roanoke River, NC. The global value of ecosystem services provided by wetlands within natural BHD is 2.5 to 2.8 mln 2007$/km2/year. BHD are very sensitive to changes in sedimentation and to changes in the rate of sea-level rise. Core descriptions, 14C geo-chronologies and grain-size analyses show that the Roanoke BHD in North Carolina, USA experienced two episodes of retreat in late Holocene. The first event occurred around ca 3500 cal. yr. BC and is recognized as a prominent flooding surface separating the delta plain environment, below, from interdistributary bay, above. Across the flooding surface rates of sediment accumulation decreased from 1.8-3.3 mm/year to 0.5-0.6 mm/year. That change was associated with increased sediment accommodation. Sedimentation rates were keeping up with the low rates of sea-level rise until 1600-1700 AD. During that time, the delta started to rapidly accrete and the interdistributary bay was buried with delta plain and prodelta sediment. This occurred in response to the low rates of sea-level rise at that time (-0.1 to 0.47 mm/year) and the release of large quantities of sediments associated with the initiation of agriculture by European settlers in the drainage basin. The second episode of retreat was initiated during the 19th century when the rate of sea-level rose to 2.1 mm/year. During that time, agricultural practices improved, decreasing the amount of sediments delivered to the mouth of the Roanoke River. Under these conditions, the delta started backstepping. Analyses of historical maps, aerial photography, and side-scan sonar data show that between

Groundwater recharge ages in the eastern nile delta based on environmental tritium

International Nuclear Information System (INIS)

Hamza, M.S.; Aly, A.I.M.; Swailem, F.M.; Nada, A.

1986-01-01

The results of the tritium composition of groundwater from eastern Nile delta is presented and compared with the tritium content of the nile according to a given model. A contour map of isoline of tritium in the area was drawn. The decrease of tritium content values in the direction from southwest to northeast was attributed to salt water intrusion. The clustered tritium isoline could be due to local geophysical structures or mixing with other water of older recharge (paleowater).2 fig.,1 tab

How to deal with subsidence in the Dutch delta?

NARCIS (Netherlands)

Stouthamer, E.; Erkens, G.

2017-01-01

In many deltas worldwide subsidence still is an underestimated problem, while the threat posed by land subsidence low-lying urbanizing and urbanized deltas exceeds the threat of sea-level rise induced by climate change. Human-induced subsidence is driven by the extraction of hydrocarbons and

Design Principles of A Sigma-delta Flux-gate Magnetometer

Science.gov (United States)

Magnes, W.; Valavanoglou, A.; Pierce, D.; Frank, A.; Schwingenschuh, K.

A state-of-the-art flux-gate magnetometer is characterised by magnetic field resolution of several pT in a wide frequency range, low power consumption, low weight and high robustness. Therefore, flux-gate magnetometers are frequently used for ground-based Earth's field observation as well as for measurements aboard scientific space missions. But both traditional analogue and recently developed digital flux-gate magnetometers need low power and high-resolution analogue-to-digital converters for signal quan- tization. The disadvantage of such converters is the low radiation hardness. This fact has led to the idea of combining a traditional analogue flux-gate regulation circuit with that of a discretely realized sigma-delta converter in order to get a radiation hard and further miniaturized magnetometer. The name sigma-delta converter is derived from putting an integrator in front of a 1-bit delta modulator which forms the sigma-delta loop. It is followed by a digital decimation filter realized in a field-programmable gate array (FPGA). The flux-gate regulation and the sigma-delta loop are quite similar in the way of realizing the integrator and feedback circuit, which makes it easy to com- bine these two systems. The presented talk deals with the design principles and the results of a first bread board model.

Stratigraphy and Evolution of Delta Channel Deposits, Jezero Crater, Mars

Science.gov (United States)

Goudge, T. A.; Mohrig, D.; Cardenas, B. T.; Hughes, C. M.; Fassett, C. I.

2017-01-01

The Jezero impact crater hosted an open-basin lake that was active during the valley network forming era on early Mars. This basin contains a well exposed delta deposit at the mouth of the western inlet valley. The fluvial stratigraphy of this deposit provides a record of the channels that built the delta over time. Here we describe observations of the stratigraphy of the channel deposits of the Jezero western delta to help reconstruct its evolution.

Alpha-, gamma- and delta-tocopherols reduce inflammatory angiogenesis in human microvascular endothelial cells.

Science.gov (United States)

Wells, Shannon R; Jennings, Merilyn H; Rome, Courtney; Hadjivassiliou, Vicky; Papas, Konstantinos A; Alexander, Jonathon S

2010-07-01

Vitamin E, a micronutrient (comprising alpha-, beta-, gamma- and delta-tocopherols, alpha-, beta-, gamma- and delta-tocotrienols), has documented antioxidant and non-antioxidant effects, some of which inhibit inflammation and angiogenesis. We compared the abilities of alpha-, gamma- and delta-tocopherols to regulate human blood cytotoxicity (BEC) and lymphatic endothelial cytotoxicity (LEC), proliferation, invasiveness, permeability, capillary formation and suppression of TNF-alpha-induced VCAM-1 as in vitro models of inflammatory angiogenesis. alpha-, gamma- and delta-tocopherols were not toxic to either cell type up to 40 microM. In BEC, confluent cell density was decreased by all concentrations of delta- and gamma-tocopherol (10-40 microM) but not by alpha-tocopherol. LEC showed no change in cell density in response to tocopherols. delta-Tocopherol (40 microM), but not other isomers, decreased BEC invasiveness. In LEC, all doses of gamma-tocopherol, as well as the highest dose of alpha-tocopherol (40 microM), decreased cell invasiveness. delta-Tocopherol had no effect on LEC invasiveness at any molarity. delta-Tocopherol dose dependently increased cell permeability at 48 h in BEC and LEC; alpha- and gamma-tocopherols showed slight effects. Capillary tube formation was decreased by high dose (40 microM) concentrations of alpha-, gamma- and delta-tocopherol, but showed no effects with smaller doses (10-20 microM) in BEC. gamma-Tocopherol (10-20 microM) and alpha-tocopherol (10 microM), but not delta-tocopherol, increased LEC capillary tube formation. Lastly, in BEC, alpha-, gamma- and delta-tocopherol each dose-dependently reduced TNF-alpha-induced expression of VCAM-1. In LEC, there was no significant change to TNF-alpha-induced VCAM-1 expression with any concentration of alpha-, gamma- or delta-tocopherol. These data demonstrate that physiological levels (0-40 microM) of alpha-, gamma- and delta-tocopherols are nontoxic and dietary tocopherols, especially delta

Subsidence, Sea Level Rise, and Seismicity in the Sacramento–San Joaquin Delta

Directory of Open Access Journals (Sweden)

Jeffrey Mount

2005-03-01

Full Text Available Anthropogenic accommodation space, or that space in the Delta that lies below sea level and is filled neither with sediment nor water, serves as a useful measure of the regional consequences of Delta subsidence and sea level rise. Microbial oxidation and compaction of organic-rich soils due to farming activity is the primary cause of Delta subsidence. During the period 1900-2000, subsidence created approximately 2.5 billion cubic meters of anthropogenic accommodation space in the Delta. From 2000-2050, subsidence rates will slow due to depletion of organic material and better land use practices. However, by 2050 the Delta will contain more than 3 billion cubic meters of anthropogenic accommodation space due to continued subsidence and sea level rise. An Accommodation Space Index, which relates subaqueous accommodation space to anthropogenic accommodation space, provides an indicator of past and projected Delta conditions. While subsidence and sea level rise create increasing anthropogenic accommodation space in the Delta, they also lead to a regional increase in the forces that can cause levee failure. Although these forces take many forms, a Levee Force Index can be calculated that is a proxy for the cumulative forces acting on levees. The Levee Force Index increases significantly over the next 50 years demonstrating regional increases in the potential for island flooding. Based on continuing increases in the Levee Force Index and the Accommodation Space Index, and limited support for Delta levee upgrades, there will be a tendency for increases in and impacts of island flooding, with escalating costs for repairs. Additionally, there is a two-in-three chance that 100-year recurrence interval floods or earthquakes will cause catastrophic flooding and significant change in the Delta by 2050. Currently, the California Bay-Delta Authority has no overarching policy that addresses the consequences of, and potential responses to, gradual or abrupt