Sample records for diamante carbonado produzido

  1. Magnetism of Carbonados

    NASA Technical Reports Server (NTRS)

    Kletetschka, G.; Taylor, P. T.; Wasilewski, P. J.


    Origin of Carbonado is not clear. Magnetism of Carbonado comes from the surface, indicating contemporary formation of both the surface and magnetic carriers. The interior of carbonado is relatively free of magnetic phases.

  2. Magnetism of Carbonados

    NASA Technical Reports Server (NTRS)

    Kletetschka, G.; Taylor, P. T.; Wasilewski, P. J.


    Carbonados are porous polycrystalline (with crystal sizes up to 100 micrometer) diamonds. Carbonado is found only in alluvial deposits in Bahia, Brazil and in the Central African Republic (CAR). Alluvial deposit host is 1.5 Ga while the carbonados are between 2.6 - 3.8 Ga. The process of fusing the carbonado microcrystals together is not fully understood, partly due to fact that the origin of these carbonado, is not known. Several modes of origins are proposed for carbonado. First, a crustal origin. Carbonados have a light carbon and helium isotopic signature. They contain an enrichment of the rare-earth elements (REE). Carbonados have tightly trapped atmospheric noble gases and contain an evidence of high He content despite the carbonado expected depletion of He at mantle temperatures. Carbonados have high porosity incompatible with high pressure mantle conditions. Second, a mantle origin is proposed based on similar REE pattern to kimberlites. The presence of nitrogen platelet (by IR spectra) indicates high temperature origin and syngenetic inclusions of rutile, ilmenite, and magnetite indicates high pressure and high temperature conditions consistent with mantle origin as well. Third, it is proposed that carbonado diamonds are a result of early impacts into crustal rocks. This is indicated by the rare and controversial occurrence of high pressure diamond polymorph, londsdaleite, frequently found in diamonds from meteorite impact sites, and by observation of planar deformation features, possibly indicating shock events. Finally, it is suggested that carbonados have an extraterrestrial origin, as indicated by a long term annealing based on observation of a zero-phonon line, attributed to paired nitrogen atoms in association with a vacancy.

  3. Carbonado-like diamond from the Avacha active volcano in Kamchatka, Russia

    NASA Astrophysics Data System (ADS)

    Kaminsky, Felix V.; Wirth, Richard; Anikin, Leonid P.; Morales, Luiz; Schreiber, Anja


    In addition to a series of finds of diamond in mafic volcanic and ultramafic massive rocks in Kamchatka, Russia, a carbonado-like diamond aggregate was identified in recent lavas of the active Avacha volcano. This aggregate differs from 'classic carbonado' by its location within an active volcanic arc, well-formed diamond crystallites, and cementing by Si-containing aggregates rather than sintering. The carbonado-like aggregate contains inclusions of Mn-Ni-Si-Fe alloys, native β-Mn, tungsten and boron carbides, which are uncommon for both carbonado and monocrystalline diamonds. Mn-Ni-Si-Fe alloys, trigonal W2C and trigonal B4C are new mineral species that were not previously found in the natural environment. The formation of the carbonado-like diamond aggregate started with formation at 850-1000 °C of tungsten and boron carbides, Mn-Ni-Si-Fe alloys and native β-Mn, which were used as seeds for the subsequent crystallization of micro-sized diamond aggregate. In the final stage, the diamond aggregate was cemented by amorphous silica, tridymite, β-SiC, and native silicon. The carbonado-like aggregate was most likely formed at near-atmospheric pressure conditions via the CVD mechanism during the course or shortly after one of the volcanic eruption pulses of the Avacha volcano. Volcanic gases played a great role in the formation of the carbonado-like aggregate.

  4. Fluid inclusions in carbonado diamond_Implication to the crystal growth environment

    NASA Astrophysics Data System (ADS)

    Kagi, H.; Ishibashi, H.; Sakurai, H.; Ohfuji, H.


    Diamond is a unique geological material carrying inside fluid and solid inclusions which are pristine witnesses of diamond crystallization media. Carbonado is natural polycrystalline diamond whose origin is still under hot depate. Our previous study on Central African carbonado reported the presence of fluid inclusions and high residual pressure in the diamond [1]. These results suggested that C-O-H mantle fluid was trapped in the carbonado sample and carbonado had grown in the volatile-rich environment in the mantle. However, it was unclear that the fluid inclusions in carbonado existed inside of diamond grains or in the grain boundaries. In this study, we precisely investigated the location of fluid inclusions from spectroscopic measurements and TEM observations. A carbonado grain with hundreds of micrometer in diameter was heated incrementally at temperatures from 700 to 1100°C under vacuum. After heating at each temperature condition, infrared absorption spectra were measured. Dehydration of hydrous minerals were observed with increasing temperature. In contrast, absorption bands assignable to liquid water were observed up to 950°C right before graphitization occurred. This observation strongly suggests that the fluid was trapped inside of diamond grains. For obtaining direct evidence of fluid inclusion existing inside of a diamond grain, we conducted TEM observations on an FIB-fabricated thin foil of carbonado. We found a void in the carbonado sample. The void was surrounded by (111) equivalent crystal faces. The octahedral void controlled by crystal habit of host diamond strongly suggests that the void is the negative crystal of diamond. The existence of negative crystal of diamond indicates that the fluid equilibrated with surrounding diamond crystals. Moreover, it was found that the grain boundary of the polished carbonado sample was in zig-zag texture. The detailed EBSD analyses on the grain boundary indicated that the grain boundary corresponded to the

  5. Carbonado: Physical and chemical properties, a critical evaluation of proposed origins, and a revised genetic model

    NASA Astrophysics Data System (ADS)

    Haggerty, Stephen E.


    Carbonado-diamond is the most controversial of all diamond types and is found only in Brazil, and the Central African Republic (Bangui). Neither an affinity to Earth's mantle, nor an origin in the crust can be unequivocally established. Carbonado-diamond is at least 3.8 Ga old, an age about 0.5 Ga older than the oldest diamonds yet reported in kimberlites and lamproites on Earth. Derived from Neo- to Mid-Proterozoic meta-conglomerates, the primary magmatic host rock has not been identified. Discovered in 1841, the material is polycrystalline, robust and coke-like, and is best described as a strongly bonded micro-diamond ceramic. It is characteristically porous, which precludes an origin at high pressures and high temperatures in Earth's deep interior, yet it is also typically patinated, with a glass-like surface that resembles melting. With exotic inclusions of highly reduced metals, carbides, and nitrides the origin of carbonado-diamond is made even more challenging. But the challenge is important because a new diamondiferous host rock may be involved, and the development of a new physical process for generating diamond is possibly assured. The combination of micro-crystals and random crystal orientation leads to extreme mechanical toughness, and a predicable super-hardness. The physical and chemical properties of carbonado are described with a view to the development of a mimetic strategy to synthesize carbonado and to duplicate its extreme toughness and super-hardness. Textural variations are described with an emphasis on melt-like surface features, not previously discussed in the literature, but having a very clear bearing on the history and genesis of carbonado. Selected physical properties are presented and the proposed origins, diverse in character and imaginatively novel, are critically reviewed. From our present knowledge of the dynamic Earth, all indications are that carbonado is unlikely to be of terrestrial origin. A revised model for the origin of

  6. Radiation-induced diamond crystallization: Origin of carbonados and its implications on meteorite nano-diamonds

    USGS Publications Warehouse

    Ozima, M.; Tatsumoto, M.


    Ten carbonados from Central Africa were studied for U-Th-Pb systematics. To extract U, Th, and Pb from the samples, we developed a cold combustion technique wherein diamond was burnt in liquid oxygen. The technique gave low blanks; 25-50 pg for Pb, 3 pg for U, and 5 pg for Th. After very thorough acid treatments of the carbonados with hot HNO3, HF, and HCl over one week, most of U, Th, and Pb were removed from the samples. Lead in the acid-leached diamonds was highly radiogenic (206Pb/204Pb up to 470). However, the amounts of U and Th in the acid-leached diamonds are too low to account for the radiogenic Pb even if we assume 4.5 Ga for the age of the diamonds. Therefore, we conclude that the radiogenic Pb was implanted into the diamonds from surroundings by means of recoil energy of radioactive decays of U and Th. From the radiogenic lead isotopic composition, we estimate a minimum age of 2.6 Ga and a maximum age of 3.8 Ga for the formation of the carbonados. The above findings of the implantation of recoiled radiogenic Pb into carbonados is consistent with the process of radiation-induced crystallization which was proposed for carbonado by Kaminsky (1987). We show from some theoretical considerations that when highly energetic particles, such as those emitted from radioactive decay of U and Th, interact with carbonaceous materials, they give rise to cascades of atomic disturbance (over regions of about a few nanometer), and the disturbed atoms are likely to recrystallize to form micro-diamonds because of increasing surface energy due to small size. The radiation-induced diamond formation mechanism may be relevant to the origin of nano-diamonds in primitive meteorites. Copyright ?? 1997 Elsevier Science Ltd.

  7. Carbonado revisited: Insights from neutron diffraction, high resolution orientation mapping and numerical simulations

    NASA Astrophysics Data System (ADS)

    Piazolo, Sandra; Kaminsky, Felix V.; Trimby, Patrick; Evans, Lynn; Luzin, V.


    One of the most controversial diamond types is carbonado, as its origin and geological history are still under debate. Here, we investigate selected carbonado samples using neutron diffraction and high resolution orientation mapping in combination with numerical simulations. Neutron diffraction analyses show that fine grained carbonado samples exhibit a distinct lack of crystallographic preferred orientation. Quantitative crystallographic orientation analyses performed on transmission electron microscope (TEM) sections reveal that the 2-10 μm grains exhibit locally significant internal deformation. Such features are consistent with crystal plastic deformation of a grain aggregate that initially formed by rapid nucleation, characterized by a high number of nucleation sites and no crystallographic preferred orientation. Crystal plastic deformation resulted in high stress heterogeneities close to grain boundaries, even at low bulk strains, inducing a high degree of lattice distortion without significant grain size reduction and the development of a crystallographic preferred orientation. Observed differences in the character of the grain boundary network and internal deformation structures can be explained by significant post-deformation annealing occurring to variable degrees in the carbonado samples. Differences in intensity of crystal bending and subgrain boundary sharpness can be explained by dislocation annihilation and rearrangement, respectively. During annealing grain energy is reduced resulting in distinct changes to the grain boundary geometry. Grain scale numerical modelling shows that anisotropic grain growth, where grain boundary energy is determined by the orientation of a boundary segment relative to the crystallographic orientation of adjacent grains results in straight boundary segments with abrupt changes in orientation even if the boundary is occurring between two triple junctions forming a ;zigzag; pattern. In addition, in diamond anisotropic

  8. The Magnetic Properties Of Aggregate Polycrystalline Diamond: Implications For Carbonado Petrogenesis

    NASA Technical Reports Server (NTRS)

    Kleteschka, Gunther; Taylor, Patrick T.; Wasilewski, Peter J.; Hill, Hugh G. M.


    Carbonados are a type of diamond, which are made up of many aggregrates of small crystalline diamonds or microdiamonds. The term "carbonado" comes from the Portuguese word carbonated. They are only found in sedimentary deposits in the Central African Republic (CAR) and the Bahia Province of Brazil. They were once the source of the world's supply of industrial diamonds. Their origin is uncertain but several mutually exclusive hypotheses have been proposed. This theories are: (1) extraterrestrial, that is they formed from the dust cloud of original solar nebulae; (2) produced by the high temperatures and pressures of the Earth's mantle; (3) or as the result of an extra-terrestrial impact into a carbon rich layer of sediment. Our study was done to further the understanding of their origin. We measured the magnetic properties on some twenty samples from the CAR. An earlier study was done on whole samples of carbonados and the "common" or kimberlitic diamond. Our work differed in that we started at the surface and subsequently removed the surface layers (by days of acid immersion) into the interior; measuring the magnetic properties at each interval. This procedure permits us to monitor the distribution of magnetic substances within the samples. Our results showed that the magnetic carriers are distributed on the surface including the open pores and that the carbonado interior is essentially non-magnetic. This result suggests that the initial formation environment was deficient in magnetic particles. Such a situation could indicate that their formation was the result of an extra-terrestrial body impacting carbon-rich sediment. Obviously, more work will be required on isotopic and chemical analyses before a more detailed ori-in can be determined.

  9. Photoconductivité et photoémission de diamant(s) sous irradiation XUV femtoseconde

    NASA Astrophysics Data System (ADS)

    Gaudin, J.; Geoffroy, G.; Guizard, S.; Esnouf, S.; Olevano, V.; Petite, G.; Klimentov, S. M.; Pivovarov, P. A.; Garnov, S. V.; Carre, B.; Martin, P.; Belsky, A.


    Nous décrivons une étude des propriétés de photoconductivité (PC) induite dans différents types de diamants (monocristaux de type IIa et couches CVD) par des impulsions femtosecondes XUV (jusqu'à l'harmonique 19 du laser titane/saphir). En complément de ces études, les spectres de photoémission de ces échantillons ont aussi été étudiés (harmoniques 13 à 27). En fonction de l'ordre de l'harmonique, on constate que le signal de PC augmente tout d'abord (harmoniques 9 à 13) puis diminue au delà. Si l'augmentation s'interprète aisément comme résultant de phénomènes de multiplication par collisions inélastiques, la diminution ultérieure n'a pas pour le moment d'explication. Les mesures de spectre de photoémission suggèrent un effet important de la relaxation par émission de plasmons. Enfin, nous avons réalisé le premier calcul ab-initio de la durée de vie des porteurs tenant compte des interactions électron-électron, à l'aide d'une approche de théorie quantique à plusieurs corps de type GW. Au voisinage du gap, on observe un comportement proche de celui d'un liquide de Fermi. A plus haute énergie on observe des déviations à ce comportement, provenant d'effets de structure de bande d'une part, et d'excitations de plasmons d'autre part.

  10. EKOSAT/DIAMANT - The Earth Observation Programme at OHB- System

    NASA Astrophysics Data System (ADS)

    Penne, B.; Tobehn, C.; Kassebom, M.; Luebberstedt

    This paper covers the EKOSAT / DIAMANT programme heading for superspectral geo-information products. The EKOSAT / DIAMANT programme is based on a commercial strategy just before the realization of the first step - the EKOSAT launch in 2004. Further, we give an overview on OHB-System earth observation prime activities especially for infrared and radar. The EKOSAT/ DIAMANT is based on the MSRS sensor featuring 12 user dedicated spectral bands in the VIS/NIR with 5m spatial resolution and 26 km swath at an orbit of 670 km. The operational demonstrator mission EKOSAT is a Korean-Israelean-German-Russian initiative that aims in utilizing the existing proto-flight model of the KOMPSAT-1 spacecraft for the MSRS sensor, which development is finished. The EKOSAT pointing capability will allow a revisit time of 3 days. DIAMANT stands for the future full operational system based on dedicated small satellites. The basic constellation relying on 2-3 satellites with about one day revisit is extendend on market demand. EKOSAT/ DIAMANT is designed to fill the gap between modern high spatial resolution multispectral (MS) systems and hyperspectral systems with moderate spatial resolution. On European level, there is currently no remote sensing system operational with comparable features and capabilities concerning applications especially in the field of environmental issues, vegetation, agriculture and water bodies. The Space Segment has been designed to satisfy the user requirements based on a balance between commercial aspects and scientific approaches. For example eight spectral bands have been identified to cover almost the entire product range for the current market. Additional four bands have been implemented to be prepared for future applications as for example the improved red edge detection, which give better results regarding environmental conditions. The spacecraft design and its subsystems are still reasonable small in order to keep the mass below 200 kg. This is an

  11. Felsic magmatism in the Southern Mariana arc: Petrogenetic comparison between Zealandia Bank and East Diamante

    NASA Astrophysics Data System (ADS)

    Shukuno, H.; Tamura, Y.; Stern, R. J.; Nunokawa, A.; Kawabata, H.; Miyazaki, T.; Senda, R.; Kimura, J.; Nichols, A. R.


    Felsic magmas have been recognized to be a significant component in intra-oceanic arc systems (IOAS), but their origin in this setting is still a matter of debate. Zealandia Bank and East Diamante are two submarine volcanoes in the Southern Marina arc that have erupted felsic magmas. Previous geologic and petrologic studies of the Diamante cross-arc volcanic chain suggest that the felsic magmas of East Diamante may be caused by the remobilization of tonalitic middle crust (Stern et al., 2010). The petrogenetic comparison between Zealandia and East Diamante volcanoes conducted in this study provides further constraints on the genesis of felsic magma in an IOAS. ROV Hyper-Dolphin dives during cruise NT09-08, on R/V Natsushima, were carried out in the Zealandia area and on the Diamante cross-arc volcanic chain. Zealandia Bank, which is built on the volcanic front, has two neighboring edifices, North and West Zealandia, on the rear-arc side. The western half of Zealandia Bank is dominated by felsic lavas, with mafic lavas having been recovered from a ridge extending to the south of the main edifice and a parasitic cone. Magnesian olivine basalts have been recovered from West Zealandia. The Diamante cross-arc volcanic chain consists of three major edifices, a caldera with felsic resurgent domes on the volcanic front (East Diamante), and two basaltic cones on the rear-arc side (West and Central Diamante). There are silica gaps at around 60 % SiO2 in both the Zealandia Bank and East Diamante magmas. Felsic lavas from East Diamante are generally porphyritic, with total phenocryst abundances up to 41 % and the assemblage consisting of quartz, plagioclase, clinopyroxene, orthopyroxene and Fe-Ti oxides. Felsic lavas from Zealandia Bank, on the other hand, generally contain less phenocrysts, with an assemblage of 1-3 % plagioclase, 0.1-0.3 % clinopyroxene, <0.1 % orthopyroxene and Fe-Ti oxides, and no quartz. Microprobe results show felsic lavas from Zealandia Bank have Ca

  12. Felsic Magmatism in Intra-Oceanic Arcs: The Diamante Cross-chain in the Southern Mariana Arc

    NASA Astrophysics Data System (ADS)

    Stern, R. J.; Tamura, Y.; Leybourne, M. I.; Nunokawa, A.; Kawabata, H.; Bloomer, S. H.; Embley, R. W.


    Felsic lavas may be more abundant than commonly thought in intra-oceanic arcs, but the origins of these magmas remain enigmatic. The Diamante Cross-chain in the southern Mariana arc provides a useful perpective on such felsic magas. This cross-chain comprises three submarine volcanoes: E. Diamante lies along the magmatic front whereas Central Diamante and W. Diamante are rear-arc volcanoes that lie above a progressively deeper subducted Pacific plate. We investigated this cross-chain by surface surveys, dredging, and ROV diving. W. Diamante is a conical basaltic volcano whereas Central Diamante is a basaltic volcano affected by recent seismicity and has a morphology that is strongly modified by E-W normal faulting. E. Diamante is elongated E-W. These relationships indicate that the location and trend of the Diamante cross-chain is controlled by an E-W extensional zone. E. Diamante encloses a shallow (floor is ~600m b.s.l.) 5 x 10 km caldera. E. Diamante caldera contains a nest of resurgent dacite domes with an active hydrothermal field (see Hein et al., this meeting). Violent “Neptunian” submarine felsic eruptions from the E. Diamante caldera created an extensive field of megadunes that extend more than 20km distant from the caldera to the north of the volcano. The NE caldera wall is composed of Late Pleistocene - Recent limestones 300m thick, probably constructed on part of an older volcano. In contrast to the moderately fractionated (mean Mg# ~55) basaltic volcanoes of Central and W. Diamante, E. Diamante has erupted lavas that are bimodal in silica, with modes at 52% and 70% SiO2. Diamante cross-chain lavas define a medium-K suite, E. Diamante has a K55 (K2O at 55% SiO2) ~0.7, Central Diamante K55 ~0.9, and W. Diamante K55 ~0.95, showing a modest increase of K55 with depth to the subduction zone. E. Diamante felsic lavas plot show a lot of compositional scatter compared to mafic lavas. It is difficult to explain formation of felsic melts via fractionation of

  13. A petrographic and geochemical study of the Wilkeson Sandstone, Eocene Carbonado Formation, at the quarry near Wilkeson, Washington

    SciTech Connect

    Knoblach, D.A.


    The Wilkeson Sandstone is a light-gray (N 7--8), very well-indurated, fluvial, lenticular, well-sorted, medium- to coarse-grained, arkosic sandstone. Located near the northwest corner of Mount Rainier National Park, west-central Washington State, the Wilkeson Sandstone is an important key rock that was included in part of the former Wilkeson Sandstone(s)/Wilkeson Formation (Willis, 1898). Incorporated into the Eocene Carbonado Formation (Gard, 1968), it is often referenced in Puget Group geological studies. The Wilkeson Sandstone was derived from an eastern highland of plutonic, metamorphic and marine sedimentary rocks, and contains minor carbonized wood debris, and rare siltstone and mudstone clasts. The cross-bedded, subangular, bimodal, first-cycle sand grains are cemented by silica, with secondary nodules of specular hematite. The unit weathers grayish-orange (10YR 7/4) and black (N 1). In the Wilkeson quarry, the bedding strikes north 30 degrees west, and dips 53 degrees northeast. In an effort to distinguish the Wilkeson Sandstone from other sedimentation units, 120 selected samples were analyzed for 25 major and trace elements using an automated x-ray spectrometer. Petrography was done with scanning electron and polarizing light microscopes. Heavy mineral separation also was performed.

  14. Beyond the Comfort Zone: Betsy Diamant-Cohen--Enoch Pratt Free Library, Baltimore

    ERIC Educational Resources Information Center

    Library Journal, 2004


    What have librarians got to do with brain research? Much more than most librarians realize, says Betsy Diamant-Cohen, Children's Programming Specialist at the Enoch Pratt Free Library, Baltimore. Her original plan was to be a social worker, but it was suggested that she could be equally effective in improving lives as a librarian--while having a…

  15. Metagenomic study of red biofilms from Diamante Lake reveals ancient arsenic bioenergetics in haloarchaea.


    Rascovan, Nicolás; Maldonado, Javier; Vazquez, Martín P; Eugenia Farías, María


    Arsenic metabolism is proposed to be an ancient mechanism in microbial life. Different bacteria and archaea use detoxification processes to grow under high arsenic concentration. Some of them are also able to use arsenic as a bioenergetic substrate in either anaerobic arsenate respiration or chemolithotrophic growth on arsenite. However, among the archaea, bioenergetic arsenic metabolism has only been found in the Crenarchaeota phylum. Here we report the discovery of haloarchaea (Euryarchaeota phylum) biofilms forming under the extreme environmental conditions such as high salinity, pH and arsenic concentration at 4589 m above sea level inside a volcano crater in Diamante Lake, Argentina. Metagenomic analyses revealed a surprisingly high abundance of genes used for arsenite oxidation (aioBA) and respiratory arsenate reduction (arrCBA) suggesting that these haloarchaea use arsenic compounds as bioenergetics substrates. We showed that several haloarchaea species, not only from this study, have all genes required for these bioenergetic processes. The phylogenetic analysis of aioA showed that haloarchaea sequences cluster in a novel and monophyletic group, suggesting that the origin of arsenic metabolism in haloarchaea is ancient. Our results also suggest that arsenite chemolithotrophy likely emerged within the archaeal lineage. Our results give a broad new perspective on the haloarchaea metabolism and shed light on the evolutionary history of arsenic bioenergetics.

  16. Metagenomic study of red biofilms from Diamante Lake reveals ancient arsenic bioenergetics in haloarchaea

    PubMed Central

    Rascovan, Nicolás; Maldonado, Javier; Vazquez, Martín P; Eugenia Farías, María


    Arsenic metabolism is proposed to be an ancient mechanism in microbial life. Different bacteria and archaea use detoxification processes to grow under high arsenic concentration. Some of them are also able to use arsenic as a bioenergetic substrate in either anaerobic arsenate respiration or chemolithotrophic growth on arsenite. However, among the archaea, bioenergetic arsenic metabolism has only been found in the Crenarchaeota phylum. Here we report the discovery of haloarchaea (Euryarchaeota phylum) biofilms forming under the extreme environmental conditions such as high salinity, pH and arsenic concentration at 4589 m above sea level inside a volcano crater in Diamante Lake, Argentina. Metagenomic analyses revealed a surprisingly high abundance of genes used for arsenite oxidation (aioBA) and respiratory arsenate reduction (arrCBA) suggesting that these haloarchaea use arsenic compounds as bioenergetics substrates. We showed that several haloarchaea species, not only from this study, have all genes required for these bioenergetic processes. The phylogenetic analysis of aioA showed that haloarchaea sequences cluster in a novel and monophyletic group, suggesting that the origin of arsenic metabolism in haloarchaea is ancient. Our results also suggest that arsenite chemolithotrophy likely emerged within the archaeal lineage. Our results give a broad new perspective on the haloarchaea metabolism and shed light on the evolutionary history of arsenic bioenergetics. PMID:26140530

  17. [Biomedical health care in Angola and in the Companhia de Diamantes de Angola, circa 1910-1970].


    Varanda, Jorge


    The scope of this paper is to analyze the provision of biomedical care in Angola during the activities of the Companhia de Diamantes de Angola. A comparative analysis of public health policies and practices of various colonial actors, such as the health services of the Company, its state counterpart and other colonial companies, will reveal differences in investment in health, namely in health facilities, personnel and treatment. This survey as well as the living conditions highlight the idiosyncratic and central nature of the health services of the Company in terms of morbidity and mortality in Angola, and the importance of these representations for a caregiving empire.

  18. Essential oil composition of Citrus meyerii Y. Tan. and Citrus medica L. cv. Diamante and their lemon hybrids.


    Verzera, Antonella; Trozzi, Alessandra; Zappalá, Mario; Condurso, Cettina; Cotroneo, Antonella


    In this paper we report the volatile fraction composition of Citrus meyerii Y. Tan. and Citrus medica L. cv. Diamante and two new lemon hybrids obtained by cross-breeding them with the tetraploid Citrus limon Burm. cv. Cavone. Both parent and hybrid oils were laboratory-extracted from the peel fruits and analyzed by HRGC-MS and HRGC-FID. Sixty-three components were fully characterized by mass spectra, linear retention indices, and injection of standards. The average composition as single components for all the oils analyzed is reported. Moreover, the data obtained were statistically analyzed. Since limonene is by far the main component of all the essential oils examined, analysis of variance and multivariate analysis gave interesting information on the similarities and differences between the oils analyzed. The new hybrid oils analyzed have potential commercial value because they could be an acceptable alternative to the valuable lemon oil.

  19. Deformation of the very neutron-deficient rare-earth nuclei produced with the SPIRAL 76Kr radioactive beam and studied with EXOGAM + DIAMANT

    SciTech Connect

    Redon, N.; Guinet, D.; Lautesse, Ph.; Meyer, M.; Rosse, B.; Stezowski, O.; France, G. de; Casandjian, J. M.


    The structure of the very neutron-deficient rare-earth nuclei has been investigated in the first experiment with the EXOGAM gamma array coupled to the DIAMANT light charged particle detector using radioactive beam of 76Kr delivered by the SPIRAL facility. Very neutron-deficient Pr, Nd and Pm isotopes have been populated at rather high spin by the reaction 76Kr + 58Ni at a beam energy of 328 MeV. We report here the first results of this experiment.

  20. Citrus medica L. cv Diamante (Rutaceae) peel extract improves glycaemic status of Zucker diabetic fatty (ZDF) rats and protects against oxidative stress.


    Menichini, Francesco; Tundis, Rosa; Loizzo, Monica R; Bonesi, Marco; D'Angelo, Danila; Lombardi, Pietro; Mastellone, Vincenzo


    This study aimed to investigate the antidiabetic, antilipidaemic and antioxidant activities of Citrus medica cv Diamante (Rutaceae) hydroalcoholic (CD) peel extract in Zucker diabetic fatty (ZDF) rats. The ability of CD to protect against oxidative stress was investigated by using different in vitro assays and in vivo by using the reactive oxygen metabolites-derived compounds (d-ROMs) test and the biological antioxidant potential test (BAP). Two different doses of CD extract (300 and 600 mg/kg/die) were administered at ZDF rats for 4 weeks. CD reduced cholesterol and triglycerides levels. A dose-dependent effect on body weight and serum glucose levels was observed. A decrease of d-ROMs and an increase of BAP were recorded by using the dose of 600 mg/kg. The extract inhibited lipid peroxidation (IC50 value of 0.23 mg/ml). These findings suggest as an efficient phytotherapeutic approach in combating hyperlipidaemic and hyperglycaemic disorders.

  1. Evidence for a deep crustal hot zone beneath the Diamante Caldera-Maipo volcanic complex, Southern Volcanic Zone

    NASA Astrophysics Data System (ADS)

    Drew, D.; Murray, T.; Sruoga, P.; Feineman, M. D.


    Subduction zones at convergent continental margins are dynamic environments that control the long-term evolution and interaction of the crust and residual mantle. The Southern Volcanic Zone (SVZ) of the Andes formed as a result of volcanic activity and uplift due to the eastern subduction of the Nazca Plate beneath the South American Plate. Maipo and neighboring volcanoes in the northern SVZ are unique in that the continental crust is exceptionally thick (~50 km), causing the mantle-derived magma to stall and interact with the crust at multiple levels prior to eruption. Maipo is an andesite/dacite stratovolcano that lies within the Diamante Caldera, which formed approximately 450 Ka during an explosive eruption that produced 350 km3 of rhyolitic ignimbrite. Following post-caldera reactivation Maipo has undergone a complex evolution, first erupting 86 Ka and experiencing seven eruptive events extending to historic times. The Maipo lavas represent a unique geochemical evolution resulting from fractional crystallization, crustal assimilation, and magma mixing in the lower and upper crust. By analyzing trace element compositions, major element compositions, and 87Sr/86Sr ratios in sixteen samples, we have begun to constrain the complex geochemical processes that formed this volcano and contribute to the differentiation of Andean continental crust. The major element analysis of the samples reflects the extent of differentiation resulting in dacite to andesite volcanic rock, and was used to distinguish between the seven eruptive events. The trace elements and Sr isotope ratios reflect the composition of the source rock, the extent of crustal assimilation, and the crystallization of minerals from the resulting mantle derived magma. The SiO2 weight percent (ranging from 54.3 to 68.5%) and 87Sr/86Sr ratios (0.7048 to 0.7057) show a linear correlation nearly identical to that reported by Hildreth and Moorbath (1988, CMP 98, 455-489) for nearby Cerro Marmolejo, suggesting a

  2. Chemical composition and bioactivity of Citrus medica L. cv. Diamante essential oil obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction.


    Menichini, Federica; Tundis, Rosa; Bonesi, Marco; de Cindio, Bruno; Loizzo, Monica R; Conforti, Filomena; Statti, Giancarlo A; Menabeni, Roberta; Bettini, Ruggero; Menichini, Francesco


    The chemical composition of the essential oil of Citrus medica L. cv. Diamante peel obtained by hydrodistillation, cold-pressing and supercritical carbon dioxide extraction techniques was determined by GC/MS analysis. Forty-six components were fully characterised. Limonene and γ-terpinene were the major components of the oils obtained by hydrodistillation (HD) and cold-pressing (CP), while citropten was the major constituent in the oil obtained by supercritical carbon dioxide extraction (SFE). Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitory activities were evaluated. The essential oil obtained by hydrodistillation exerted the highest inhibitory activity against BChE (IC₅₀ value of 154.6 µg mL⁻¹) and AChE (IC₅₀ value of 171.3 µg mL⁻¹. Interestingly, the oil obtained by cold-pressing exhibited a selective inhibitory activity against AChE. The essential oils have also been evaluated for the inhibition of NO production in LPS induced RAW 264.7 macrophages. The oil obtained by hydrodistillation exerted a significant inhibition of NO production with an IC₅₀ value of 17 µg mL⁻¹ (IC₅₀ of positive control 53 µg mL⁻¹).

  3. Do the Ubangui diamonds originate from a giant impact?

    NASA Astrophysics Data System (ADS)

    Shelkov, D.; Milledge, H. J.; Verchovsky, A. B.; Hutchison, R.; Collinson, D. W.; Pillinger, C. T.


    Carbonado wa first recognized as a form of polycrystalline diamond as long ago as the 1840s, when it was discovered and mined as a placer mineral in Brazil. It is now known from a number of other sources, where it is colloquially known as 'carbons.' Common to all these samples is the fact that they occur in alluvial deposits far from primary diamond-bearing rocks such as kimberlite and lamporite. Several authors have suggested that carbonado might have a crustal origin. Recently, it has been proposed that a magnetic anomaly spread over 700,000 sq km of Central Africa might be interpreted as a crater formed by an impact that occurred in sedimentary rocks during Precambrian times; if authenticated this would be the largest impact feature recognized to date. Such a hypothesis makes the investigation of Ubangui diamonds and other carbonados worhtwhile. We considered isotopic systematics and other properties of a variety of intact Ubangui carbons. Because of their importance as grinding and polishing materials microcrystalline diamonds are usually crushed before marketing; the stones we obtained were not and showed a surface rind with a texture very reminiscent of a fusion crust. We have now made C isotopic measurements on five approximately centimeter-sized specimens. We have also begun to study N and its isotopes in carbonados. The results were comparable to data obtained for Brazilian carbonados. So far we have not detected any differences for N between the heavy C diamond and the rest of our samples.

  4. Time-Dependent Morphologies and Viscoelastic Properties of Block Copolymers.

    DTIC Science & Technology


    been shown proportional to the relative amounts of those phases (17). Diamant and coworkers (14-16) showed that the viscoelastic behavior between the...traditionally been associated with the re- lative amounts of styrene and butadiene in their respective domains (35). Recently, Diamant and coworkers (14-i6...understood at present. However, Diamant and coworkers (14-16) showed that a maximum in G"(T) between the two main transitions could be attributed to a "bulge

  5. Dynamic High-Pressure Shock Compaction of Diamond Powders

    DTIC Science & Technology


    superhard cutting tools and wear-resistant coatings for mechanical and optical components, to heat-sink substrates for electronic semi-conductor devices.2...tions. Carbonados can also be synthesized and sintered to make * cutting tools . Ballas diamonds are round, dense and randomly oriented polycrystals

  6. Evaluation of GEOSAT Data and Application to Variability of the Northeast Pacific Ocean

    DTIC Science & Technology


    while Diamante and Nee (1981) determined tidal constituents from GEOS-3 derived sea surfaces. Cheney and Marsh I (1981b) mapped mesoscale variability...Miller, L.L., and Porter , D.L. 1987. Geosat altimeter geophysical data record (GDR) user handbook. Rockville, MD: I NOAA National Ocean Service...University Applied Physics Laboratory Report 7292-9510. First revision. i I I 159 I Diamante , J.M., and Nee, T.S. 1981. Application of satellite

  7. Evaluation of GEOSAT (Geodetic Satellite) Data and Application to Variability of the Northeast Pacific Ocean

    DTIC Science & Technology


    locales using GEOS-3 outputs, while Diamante and Nee (1981) determined tidal constituents from GEOS-3 derived sea surfaces. Cheney and Marsh (1981b...and Porter , D.L. 1987. Geosat altimeter geophysical data record (GDR) user handbook. Rockville, MD: NOAA National Ocean Service. Cheney, R.E., and Marsh...Physics Laboratory Report 7292-9510. First revision. 15 Diamante , J.M., and Nee, T.S. 1981. Application of satellite radar altimeter data to the

  8. On possibility of diamond formations in radiation process

    NASA Technical Reports Server (NTRS)

    Fisenko, A. V.; Semjonova, L. F.; Bolsheva, L. N.; Grachjova, T. V.; Verchovsky, A. B.; Shukolyukov, Yu. A.


    The possibility of diamond formation in radiation processes was checked by studying diamond contents in carburanium sample. The diamonds were not found and this result is discussed. At present one possible process of formation of nanometer-size diamond crystals in some meteorites and Earth's diamonds (carbonado), the radiation mechanism, is suggested: the formation of diamonds from carbonaceous matter in tracks of U fragment fissions and heavy fragmentation due to the action of energetic particles of cosmic rays. Bjakov et. al. have carried out the calculations and shown that the volume of formed diamonds in carbonaceous chondrites by radiation processes corresponds to discovery of diamond volume in chondrites. The discovery by Ozima et. al. of the unsupported fission of Xe and Kr in carbonado supports the supposition that carbonado could be formed by radiation processes. The possibility of diamond formation in radiation processes leads to the study of diamond contents in Earth's samples enriched by uranium and carbon. The attempt to release the diamonds from carburanium was undertaken.

  9. SHMUTZ & PROTON-DIAMANT H + Irradiated/Written-Hyper/Super-conductivity(HC/SC) Precognizance/Early Experiments Connections: Wet-Graphite Room-Tc & Actualized MgB2 High-Tc: Connection to Mechanical Bulk-Moduli/Hardness: Diamond Hydrocarbon-Filaments, Disorder, Nano-Powders:C,Bi,TiB2,TiC

    NASA Astrophysics Data System (ADS)

    Wunderman, Irwin; Siegel, Edward Carl-Ludwig; Lewis, Thomas; Young, Frederic; Smith, Adolph; Dresschhoff-Zeller, Gieselle


    SHMUTZ: ``wet-graphite''Scheike-....[Adv.Mtls.(7/16/12)]hyper/super-SCHMUTZ-conductor(S!!!) = ``wet''(?)-``graphite''(?) = ``graphene''(?) = water(?) = hydrogen(?) =ultra-heavy proton-bands(???) = ...(???) claimed room/high-Tc/high-Jc superconductOR ``p''-``wave''/ BAND(!!!) superconductIVITY and actualized/ instantiated MgB2 high-Tc superconductors and their BCS- superconductivity: Tc Siegel[ICMAO(77);JMMM 7,190(78)] connection to SiegelJ.Nonxline-Sol.40,453(80)] disorder/amorphous-superconductivity in nano-powders mechanical bulk/shear(?)-moduli/hardness: proton-irradiated diamond, powders TiB2, TiC,{Siegel[Semis. & Insuls.5:39,47, 62 (79)])-...``VS''/concommitance with Siegel[Phys.Stat.Sol.(a)11,45(72)]-Dempsey [Phil.Mag. 8,86,285(63)]-Overhauser-(Little!!!)-Seitz-Smith-Zeller-Dreschoff-Antonoff-Young-...proton-``irradiated''/ implanted/ thermalized-in-(optimal: BOTH heat-capacity/heat-sink & insulator/maximal dielectric-constant) diamond: ``VS'' ``hambergite-borate-mineral transformable to Overhauser optimal-high-Tc-LiBD2 in Overhauser-(NW-periodic-table)-Land: CO2/CH4-ETERNAL-sequestration by-product: WATER!!!: physics lessons from

  10. Transient Structures and Rheological Properties of SBS Block Copolymer Melts.

    DTIC Science & Technology


    Henderson and M.C. Williams, J. Polym. Sci., Polymer Letters, 17, 257 (1979). [111 E.V. Gouinlock and R.S. Porter , Polym. Eng. Sci., 17, 535 (1977...6, 277 (1974). II -16- [18] G. Akovali, J. Diamant , and M. Shen, J. Macromol. Sci., Phys. Ed., 13, 117 (1977). [191 Y.D.M. Chen and R.E. Cohen, J...Polym. Eng. Sci. [22] G. Kraus and R.W. Rollman, J. Polym. Sci., Polym. Phys. Ed., 14, 1133 (1976). [23] J. Diamant , D.S. Soong and M.C. Williams in

  11. Radiation Halos, a Rare Microstructure in Diamonds From the Central African Republic

    NASA Astrophysics Data System (ADS)

    Vicenzi, E. P.; Heaney, P. J.; Snyder, K.; Armstrong, L.


    The geochemical characterization of bulk diamonds and associated inclusions as a tool for determining provenance carries significant inherent limitations. Isotopic and trace element signatures are imparted within the mantle during diamond growth; hence, discriminating crystals from a particular region on the Earth's surface on this basis is difficult at best, and impossible (using current technologies) in many cases. In contrast, rare diamond characteristics may provide a partial solution for recognizing stones from a limited number of localities. Here we discuss an analysis of radiation halos in alluvially deposited polycrystalline diamonds (carbonados) from the Central African Republic (CAR). Large amounts of implanted Xe and Kr, as well as isotopic ratios of those elements consistent with fission, in carbonado strongly suggest that diamond crystallization took place in the presence of significant quantities of uranium [1]. Such ionizing radiation ultimately results in the loss of periodicity of the diamond structure. Crystallographically damaged areas produce fewer photons in cathodoluminescence microscopy, and therefore, the metamict regions resulting from point source radiation in diamond can be visualized on the scale of ~1-25 micrometers [2]. Because intermediate daughter products in the decay chain release alpha particles at differing energies, a ``bull's eye'' pattern is produced in 2-D by the point source radiation. Radiation haloes have been previously observed in carbonados and are thought to result from U deposition associated with fluids following diamond formation [3,4]. We have made a series of measurements of the apparent diameter of the largest circle within a damage halo. By comparing the statistical distribution of this dimension to the distribution expected for a series of circles resulting from random sectioning of mono-sized spheres, one can estimate whether the radiation resulted from one or more fluid pulses widely separated in time

  12. Children's Services: Partnerships for Success

    ERIC Educational Resources Information Center

    Diamant-Cohen, Betsy, Ed.


    Co-author of the popular titles "Booktalking Bonanza" and "The Early Literacy Kit", Betsy Diamant-Cohen brings together 18 examples of successful outreach partnerships that children's librarians and administrators can adapt to their own situations. Contributors from the U.S and Canada explain how they partnered with schools,…

  13. Transport Code for Regular Triangular Geometry

    SciTech Connect


    DIAMANT2 solves the two-dimensional static multigroup neutron transport equation in planar regular triangular geometry. Both regular and adjoint, inhomogeneous and homogeneous problems subject to vacuum, reflective or input specified boundary flux conditions are solved. Anisotropy is allowed for the scattering source. Volume and surface sources are allowed for inhomogeneous problems.

  14. Poetry Extravaganza.

    ERIC Educational Resources Information Center

    Marion, L. Marvin

    Twenty-six poetic forms are discussed in this paper, with suggested activities for teaching these patterns to students in grades kindergarten through grade twelve. The forms that are discussed include the couplet, quatrain, triplet, limerick, free verse, haiku, cinquain, sijo, septolet, diamante, acrostic, sonnet, parody, dramatic monologue, and…

  15. A Pop-Up, Cut-and-Paste, Knockout Approach to Creative Writing.

    ERIC Educational Resources Information Center

    Miller, Etta; And Others


    Hearing-impaired students can be encouraged to write creatively through such novelty book formats as: shape books, accordion-fold books, alphabet books, rebus books, books with page shape variations, diamante poems, play-along books, guessing books, pattern books, and pop-up and cutout books. (DB)

  16. Writing in the Language Arts.

    ERIC Educational Resources Information Center

    Ediger, Marlow

    Pupils should participate in numerous forms and kinds of writing activities involving poetry and should hear, read, and write different forms and kinds of prose. Types of poetry that pupils can write include couplets, triplets, quatrains, limericks, free verse, haiku, and diamante. The ingredients that all types of poetry might have include…

  17. British Defense Policy: A New Approach?

    DTIC Science & Technology


    members of my thesis committee: Professors Christoph, Diamant and Furniss. Their insightful comments and timely responses to my writings have enabled us...only one secretary, two chief clerks, six subordinate clerks, one messenger, two servants, one porter , one watchman and a woman cleaner 12 - obviously a

  18. Global Ocean Tides. Part X. The Fortnightly Lunar Tide (Mf) Atlas of Tidal Charts and Maps.

    DTIC Science & Technology


    NOAA/National Center for Atmospheric National Geodetic Survey Research ATTN: Dr. B. Chovitz ATTN: Dr. W. R. Holland Dr. J. M. Diamante Boulder, CO...NOAA/National Ocean Survey T. L. Felsentreger Oceanographic Division J. Zwally ATTN: D. C. Simpson Greenbelt, MD 20771 D. L. Porter R. A. Smith NASA

  19. On Computing Instantaneous Geocentric Tides Along Satellite Tracks, the NSWC STT Program.

    DTIC Science & Technology


    J. M. Diamante (1) Boulder, CO 80303 Dr. B. C. Douglas (1) Dr. C. C. Goad (1) NASA/Goddard Space Flight Center Dr. F. Morrison (1) Attn: Dr. J. W...Attn: LCDR A. N. Bodnar (1) Greenbelt, MD 20771 D. C. Simpson (1) D. L. Porter (1) NASA/Wallops Station R. A. Smith (1) Information Processing and

  20. The U.S. Submarine Production Base. An Analysis of Cost, Schedule, and Risk for Selected Force Structures

    DTIC Science & Technology


    Porter , Director, Acquisition Program Integration, and David Gompert, Director, NDRI. We also want to thank the leadership and staff of the Office of...hull and reactor components were completed; this boat is currently in storage. The eighth boat, the Diamant , was canceled. 3This is not, of course, a

  1. {gamma}-ray Spectroscopy of Proton Drip-Line Nuclei in the A{approx}130 Region using SPIRAL beams

    SciTech Connect

    Stezowski, O.; Guinet, D.; Lautesse, Ph.; Meyer, M.; Redon, N.; Rosse, B.; Schmitt, Ch.; De France, G.; Bhattachasyya, S.; Mukherjee, G.


    A fusion-evaporation experiment has been performed with a SPIRAL {sup 76}Kr radioactive beam in order to study the deformation of rare-earth nuclei near the proton drip-line. The experimental setup consisted in the EXOGAM {gamma}-array, coupled to the light-charged particles (LCP) DIAMANT detector and to the VAMOS heavy-ion spectrometer. The difficulties inherent to such measurements are enlightened. The coupling between EXOGAM and DIAMANT has been used to decrease the huge background caused by the radioactivity of the beam. It further permits assigning new {gamma}-ray transitions to specific residual nuclei. A {gamma}-ray belonging to the {sup 130}Pm level scheme has thus been observed for the first time.

  2. Global Ocean Tides. Part IV. The Diurnal Luni-Solar Declination Tide (K1), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology


    1979). Private Communications: I). (. Simpson ((1977). National Ocean Survey, Rockville, Maryland, S. K. Gill and D. L. Porter ( IlIXS), National...80303 National Geodetic Survey ATTN: Dr. W. R. Holland Rockville, MD 20852 ATTN: Dr. B. Chovitz NASA/Goddard Space Flight (’enter Dr. J. M. Diamante ... Porter Branch R. A. Smith Wallops Island, VA 23337 B. B. Parker ATTN: C. I). Leitao N. I.. Huang NOAA Atlantic Oceanographic and W. B. Krabill

  3. Global Ocean Tides. Part VI. The Semidiurnal Elliptical Lunar Tide (N2), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology


    Rockville, Maryland; S. K. Gill and D. L. Porter (1978), National Ocean Survey, Rockville, Maryland; K. Wyrtki (1978), University of Hawaii, Honolulu...ATTN: Dr. B. Chovitz Dr. J. M. Diamante Dr. B. C. Douglas Dr. C. C. Goad Dr. F. Morrison NOAA/National Ocean Survey Oceangraphic Division...Rockville, MD 20852 ATTN: D.C.Simpson D. L. Porter R. A. Smith B. B. Parker NOAA/Atlantic Oceanographic and Meteorological Lab. Physical

  4. Global Ocean Tides. Part VIII. The Semidiurnal Luni-Solar Declination Tide (K2), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology


    and D. L. Porter (1978), National Ocean Survey, Rockville, Maryland; K. Wyrtki (1978), University of Hawaii, Honolulu, Hawaii, and D. E. Cartwright...NASA/Goddard Space Flight Center Dr. J. M. Diamante Greenbelt, MD 20771 Dr. B. C. Douglas ATTN: Dr. J. W. Siry Dr. C. C. Goad D. E. Smith Dr. F...Simpson Information Processing and Analysis D. L. Porter Branch R. A. Smith Wallops Island, VA 23337 B. B. Parker ATTN: C.D. Leitao N. E. Huang NOAA

  5. Global Ocean Tides. Part IX. The Diurnal Elliptical Lunar Tide (Q1), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology


    D. L. Porter (1978), National Ocean Survey, Rockville, Maryland; K. Wyrtki (1978), University of Hawaii, Honolulu, Hawaii, and D. E. Cartwright and D...MD 20852 ATTN: Dr. 13. Chovitz NASA/Goddard Space Flight Center Dr. J. M. Diamante Greenbelt, MD 20771 Dr. B. C. Douglas ATTN: Dr. J. W. Siry Dr. C...NASA/Wallops Station ATTN: D. C. Simpson Information Processing and Analysis D. L. Porter Branch R. A. Smith Wallops Island, VA 23337 B. B. Parker ATTN

  6. Submarine Arc Volcanism in the Southern Mariana Arc: Results of Recent ROV studies

    NASA Astrophysics Data System (ADS)

    Nichols, A. R.; Tamura, Y.; Stern, R. J.; Embley, R. W.; Hein, J. R.; Jordan, E.; Ribeiro, J. M.; Sica, N.; Kohut, E. J.; Whattam, S. A.; Hirahara, Y.; Senda, R.; Nunokawa, A.


    The submarine Diamante cross-arc volcanoes (~16°N) and the Sarigan-Zealandia Bank Multi-Volcano Complex (SZBMVC; ~16°45’N), north and south, respectively, of Anatahan Island in the southern Mariana Arc, were studied during several dives in June 2009 using the ROV Hyper-Dolphin, cruise NT09-08 (R/V Natsushima); neither has been studied in detail before. The data collected provide a new perspective on how the subduction factory operates to complement previous studies on other cross-arc volcanic chains in the Izu-Bonin-Mariana Arc. The Diamante complex consists of three major edifices, two cones (West and Central Diamante) and a more complex caldera-like edifice at the volcanic front (East Diamante). West and Central Diamante are basaltic volcanoes but East Diamante has a more complex history. Our studies indicate initial construction of a basaltic volcano. Magmatic evolution led to a violent caldera-forming and quieter dome-building events. Post-caldera quiescence allowed a carbonate platform to grow, now preserved on the eastern caldera wall. Felsic magma or hot rock provides a heat source for an active hydrothermal field associated with felsic domes in the caldera, which NOAA investigators discovered in 2004. A new type of hydrothermal deposit was discovered in the hydrothermal field, consisting of large sulfide-sulfate mounds topped by bulbous constructions of low-temperature Fe and Mn oxides. Vents on the mounds were observed to emit shimmering water. The SZBMVC consists of six closely spaced edifices whose loci are aligned along two parallel trends, one along the volcanic front (Zealandia Bank, Sarigan and South Sarigan), and one about 15 km west towards the rear-arc (Northwest Zealandia, West Zealandia and West Sarigan). Zealandia Bank dives revealed that, as with East Diamante, initial activity was basaltic and became more evolved with time. The western half of Zealandia Bank is dominated by felsic lavas centered on a small (~2 km diameter) caldera and

  7. High-Spin Structure of 102Ru

    SciTech Connect

    Sohler, D.; Timar, J.; Molnar, J.; Algora, A.; Dombradi, Zs.; Krasznahorkay, A.; Zolnai, L.; Rainovski, G.; Joshi, P.; Wadsworth, R.; Jenkins, D.G.; Raddon, P.M.; Simons, A.J.; Wilkinson, A.R.; Starosta, K.; Fossan, D.B.; Bednarczyk, P.; Curien, D.; Duchene, G.; Gizon, A.


    High-spin states in the nucleus 102Ru have been studied through the 96Zr(13C,{alpha}3n) reaction using the EUROBALL IV {gamma}-ray spectrometer accompanied by the DIAMANT array for the detection of charged particles. All previously known bands have been extended to higher spins and additional bands have been found. Comparing the experimental Routhians and aligned angular momenta to the predictions of Woods-Saxon TRS calculations, vh11/2(d5/2,g7/2) configurations have been assigned to the observed negative-parity bands.

  8. Characterisation Of Polysacharides And Lipids From Selected Green Algae Species By FTIR-ATR Spectroscopy

    NASA Astrophysics Data System (ADS)

    Bartošová, Alica; Blinová, Lenka; Gerulová, Kristína


    Fourier transform infrared (FTIR) spectroscopy was used in this study to identify and determine spectral features of Chromochloris zofingiensis (Dönz) Fucíková et L.A. Lewis (SAG 211-14, Gottingen, Germany), Acutodesmus obliguus (Turpin) Hegewald (SAG 276-1, Gottingen, Germany) and Chlorella sorokiniana (K. Brandt) Pröschold et Darienko (SAG 211-40c, Gottingen, Germany). Polysaccharides and lipids from these three algae species were determined using Fourier Transformed Infrared Spectroscopy (FTIR) with ATR accessory with diamante crystal in spectral range from 400 - 4000 cm-1 and resolution 4.

  9. Global Ocean Tides. Part V. The Diurnal Principal Lunar Tide (O1), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology


    Private Communications: D. C. Simnpson (1977), National Ocean Survey, Rockville, Maryland; S. K. Gill and 1). L. Porter (1978), National Ocean Survey...M. Diamante Greenbelt, MD 20771 Dr. B. C. Douglas ATTN: Dr. J. W. Siry IDr. C. C. Goad D. E. Smith Dr. F. Morrison J. G. Marsh I. L. F lsentreer...Analvsis 1). L. Porter Branch R. A. Smith Wallops siand. VA 23337 B. ti. Plarker ATTN: C. 1). Leitao N. I. Iuane N(O)AA Atlantic ()ceanographic and W. B. K

  10. Phase Relations and Miscibility in Polymer Blends Containing Copolymers.

    DTIC Science & Technology


    Porter , R. S., Polymer Eng. Sci. 17, 534 (1977). 54. Roe, R. J., Fishkis, M., and Chang, J. C., Macromolecules 14, 1091 (1981). 55. Leibler, L...Kimura, M. and Porter , R. S., J. Polymer Sci.: Polymer Phys. Ed. 22, 1697 (1984). 113. Clas, S. D. and Eisenberg, A., J. Polymer Sci.: Polymer Phys. Ed... Diamant , J., Soong, D., and Williams, M. C., Polymer Eng. Sci. 22, 673 (1982). 147. Choi, G., Kaya, A., and Shen, M., Polymer Eng. Sci. 1_3, 231 (1973

  11. Global Ocean Tides. Part VII. The Diurnal Principal Solar Tide (P1), Atlas of Tidal Charts and Maps.

    DTIC Science & Technology


    Survey, Rockville, Maryland; S. K. Gill and D. L. Porter (1978), National Ocean Survey, Rockville, Maryland; K. Wyrtki (1978), University of Hawaii...Rockville, M) 20852 ATTN: )r. B. (’hovitz NASA/Goddard Space Flight Center l)r. J. M. Diamante Greenbelt. MI) 20771 Dr. B. C. )ouglas ATTN: l)r. J. W. Siry Dr...20852 NASA/Wallops Station A I IN: 1). C. Simpson Inlormation Processing and Analysis 1). L. Porter Branch R. A. Smith Wallops Island, VA 23337 It. It

  12. Life-history parameters of the Colorado potato beetle, Leptinotarsa decemlineata, on seven commercial cultivars of potato, Solanum tuberosum.


    Fathi, Seyed Ali Asghar; Fakhr-Taha, Zoha; Razmjou, Jabraeil


    The Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae), is an important pest of potato, Solanum tuberosum L. (Solanales: Solanaceae), crops in the Ardabil region of Iran. In this research, the life-history parameters of L. decemlineata were investigated on seven potato cultivars, namely Agria, Aozonia, Diamant, Cosmus, Kondor, Morene, and Savalan, in a greenhouse at 23 ± 1° C and 55 ± 5% RH under a natural photoperiod. The results indicated that the development time of larvae was longest on Savalan (18.3 days) among the tested potato cultivars. The survival rates (egg to adult) on Savalan and Morene were significantly lower than on the other studied cultivars. L. decemlineata reared on Savalan had the lowest fecundity (286.3 eggs/female) among the tested potato cultivars. The oviposition period of females was significantly shorter on Savalan and Diamant than on Kondor, Aozonia, Morene, Agria, and Cosmus. The values of intrinsic rate of natural increase and population growth rate were lowest on Savalan (0.055 and 1.056, respectively). The generation time and doubling time were significantly longest on Savalan (69.5 and 12.7 days, respectively). Based on these results, it can be concluded that Savalan is the least suitable cultivar for L. decemlineata among the ones tested. These results can be useful in integrated management of L. decemlineata in potato fields.

  13. Magnetoresistance and electrical properties of multi-component copper chalcogenides at pressures up to 50 GPa

    NASA Astrophysics Data System (ADS)

    Melnikova, Nina; Tebenkov, Alexander; Babushkin, Alexey; Kurochka, Kirill; Phase Transitions Team; Transport Properties Team; Novel Materials Team


    Multi-component chalcogenides based on layered semiconductors A3B6 (such as InS, InSe, GaS, GaSe, etc) are new objects of study, they have interesting physical properties and undergo temperature and baric phase transitions. This paper presents the results of a study of the electrical properties and magnetoresistance of CuInS2, CuInSe2, CuInAsS3, CuInAsSe3, CuInSbS3 at pressures up to 50 GPa. High pressures have been generated in the cell with synthetic carbonado-type diamond anvils that can be used as electric contacts. Electric properties at high pressure have been investigated on dc current and by means of impedance spectroscopy. Magnetoresistance has been measured in transverse magnetic field. The pressure ranges of noticeable changes in a behavior of magnetoresistance, of impedance and admittance, tangent of loss angle, relaxation time upon a pressure increase and a pressure decrease are established. This behavior of physical parameters can be due to structural transitions and due to a change of electron structure. This work was supported in part by the Russian Foundation for Basic Research, project no. 13-02-00633.

  14. Ultra-hard polycrystalline diamond synthesized by direct conversion of graphite using multianvil apparatus

    NASA Astrophysics Data System (ADS)

    Irifune, T.; Kurio, A.; Sakamoto, S.; Inoue, T.; Sumiya, H.


    Occurrence of sintered polycrystalline diamonds, such as carbonado and ballas, has been reported in some diamond mines, although the production rate has been very limited and their origin has been unsolved. These polycrystalline diamonds are most valuable in industrial applications because they are often harder than single crystal diamonds, whose hardness depends largely upon the crystallographic directions. Synthesis of pure polycrystalline diamond, however, has been unsuccessful, whereas single crystal diamond has been produced using some catalysts or solvents by high-pressure synthesis since its success in 1950's. Here, we report the first synthesis of a pure massive polycrystalline diamond by direct conversion of graphite without any catalysts/solvents under static high pressure and high temperature. Thus synthesized diamond at pressures 12-25 GPa and temperatures 2300-2500°C was optically transparent and colorless, and consisted of minute crystals of typically 1020 nanometers. Moreover, it was found that the Knoop hardness of the present diamonds is 110-140 GPa, which is higher than those of any known materials, including high quality synthetic type IIa diamond

  15. The Anatahan Felsic Province in the Mariana Arc System

    NASA Astrophysics Data System (ADS)

    Stern, R. J.; Hargrove, U. S.


    The May 2003 plinian eruption of Anatahan was a surprise for the residents of the Northern Mariana Mariana Comonwealth (USA). From a petrologic perspective, this eruption of siliceous andesite was also atypical for the Mariana arc, which elsewhere mostly erupts fractionated basalts and basaltic andesites. However, felsic eruptions are not unusual for Anatahan which has previously erupted a wide range of lavas, from basalts through dacites. The reasons and significance of the intermittently felsic nature of Anatahan lavas may reflect either development of a mature magma chamber localized beneath Anatahan or perhaps the presence of an areally-extensive pool of felsic magma in the middle crust, similar to that inferred for the Izu arc to the north. Anatahan lies at the southern end of the Mariana Central Island Province and just north of the Southern Seamount Province, but it has never been clear whether these morphological subdivisions reflect different magma fluxes along the arc or are due to the island volcanoes being older than the seamounts. Synthesis of existing data for Anatahan and data for surrounding seamounts collected during the 2001 Cook 7 expedition and earlier cruises indicates that Anatahan is situated near the middle of an arc segment with an unusually high proportion of felsic lavas compared to typical Mariana Arc magmatic products. The 115 km-long arc segment from E. Diamante seamount East Diamante seamount (15° 55'N) to a seamount NW of Zealandia Bank (17° N) define the Anatahan Felsic Province (AFP). Seven edifices within this region, including Anatahan, have erupted felsic lavas, often interspersed with more mafic lavas. Volcano size does not seem important in controlling the abundance of felsic lavas within the AFP; the volcanic island of Sarigan does not contain felsic lavas, whereas small parasitic cones NE of Anatahan and SW of E. Diamante erupt lavas with 65% and 72% SiO2, respectively. This region also contains two suspected hydrothermal

  16. [Leaf micrografic anatomy of the Neotropical palm Bactris gasipaes (Arecaceae)].


    Chaimsohn, Francisco Paulo; Montiel, Mayra; Villalobos, Enrique; Mora Urpi, Jorge


    The economic importance of the palm Bactris gasipaes is growing in the Neotropoical region. We collected leaflets from plants under a chemical fertilization regime and a population of 5000 plants per hectare, in Costa Rica. The variety, Diamantes 10, has an ascendency fom the upper Amazon basin. We used Harries hematoxiline, eocine and standard light microscopy techniques. The presence of raphids and buliform cells was confirmed for the abaxial surface of the leaflets and for the hypodermic tissue on both sides. The absence of the Krantz anatomy was confirmed in consistence with former observations about the C3 photosynthesis in other species of Palmaceae. The average stomatal density on the abaxial surface was 96.87 +/- 16.31 and 14.20 +/- 4.05 in the adaxial surface.

  17. CRISPR System Acquisition and Evolution of an Obligate Intracellular Chlamydia-Related Bacterium

    PubMed Central

    Bertelli, Claire; Cissé, Ousmane H.; Rusconi, Brigida; Kebbi-Beghdadi, Carole; Croxatto, Antony; Goesmann, Alexander; Collyn, François; Greub, Gilbert


    Recently, a new Chlamydia-related organism, Protochlamydia naegleriophila KNic, was discovered within a Naegleria amoeba. To decipher the mechanisms at play in the modeling of genomes from the Protochlamydia genus, we sequenced the full genome of Pr. naegleriophila, which includes a 2,885,090 bp chromosome and a 145,285 bp megaplasmid. For the first time within the Chlamydiales order, we describe the presence of a clustered regularly interspaced short palindromic repeats (CRISPR) system, the immune system of bacteria, located on the chromosome. It is composed of a small CRISPR locus comprising eight repeats and associated cas-cse genes of the subtype I-E. A CRISPR locus is also present within Chlamydia sp. Diamant, another Pr. naegleriophila strain, suggesting that the CRISPR system was acquired by a common ancestor of Pr. naegleriophila, after its divergence from Pr. amoebophila. Both nucleotide bias and comparative genomics approaches identified probable horizontal gene acquisitions within two and four genomic islands in Pr. naegleriophila KNic and Diamant genomes, respectively. The plasmid encodes an F-type conjugative system highly similar to 1) that found in the Pam100G genomic island of Pr. amoebophila UWE25 chromosome, as well as on the plasmid of Rubidus massiliensis and 2) to the three genes remaining in the chromosome of Parachlamydia acanthamoebae strains. Therefore, this conjugative system was likely acquired on an ancestral plasmid before the divergence of Parachlamydiaceae. Overall, this new complete Pr. naegleriophila genome sequence enables further investigation of the dynamic processes shaping the genomes of the family Parachlamydiaceae and the genus Protochlamydia. PMID:27516530

  18. Fabrication de transistors mono-electroniques en silicium pour le traitement classique et quantique de l'information: une approche nanodamascene

    NASA Astrophysics Data System (ADS)

    Harvey-Collard, Patrick

    Les transistors mono-electroniques (SETs) sont des dispositifs ayant un grand potentiel d'applications, comme la detection de charge ultra-sensible, la logique a basse consommation de puissance, la memoire ou la metrologie. De plus, la possibilite de pieger un seul electron et de manipuler son etat de spin pourrait permettre des applications en informatique quantique. Le silicium est un materiau interessant pour fabriquer l'ilot d'un SET. Son gap semi-conducteur permet le fonctionnement du dispositif dans le regime a un seul electron ou trou et pourrait permettre d'etendre la plage d'operation du SET en temperature en augmentant l'energie d'addition du diamant central de la valeur du gap. En outre, le silicium beneficie de plus de quarante annees d'expertise en microfabrication et d'une compatibilite avec la technologie metal--oxyde--semi-conducteur complementaire (CMOS). Cependant, la fabrication de ces dispositifs fait face a de serieuses limitations a cause de la taille nanometrique requise pour l'ilot. A ce jour, les procedes de fabrication proposes permettant l'operation a la temperature ambiante sont trop peu reproductibles pour permettre des applications a grande echelle. Dans ce memoire de maitrise, la fabrication de transistors mono-electroniques en silicium (Si-SETs) pour le traitement classique et quantique de l'information est realisee avec un procede nanodamascene. Le polissage chimico-mecanique (CMP) est introduit comme etape clef de la fabrication du transistor, permettant le controle au nanometre pres (nanodamascene) de l'epaisseur du transistor. Cet outil permet la fabrication de dispositifs ayant une geometrie auparavant impossible a realiser et ouvre la porte a l'innovation technologique. De plus, un procede de gravure du silicium par plasma a couplage inductif (ICP) est developpe pour permettre la fabrication de nanostructures de silicium sur une nanotopographie alliant le nano et le 3D. Les Si-SETs fabriques sont caracterises a basse

  19. Distribution and origin of diamonds in Brazil: An overview

    NASA Astrophysics Data System (ADS)

    Svisero, Darcy P.


    Brazil was the first western country to produce diamonds from the washing of alluvial deposits found in central Minas Gerais in the early 1700s. For a century the country remained the world's greatest producer, losing its position only after the discovery of the Kimberley field in South Africa. Currently there are placer deposits (garimpos) scattered throughout the majority of the states with official production averaging 1,000,000 ct/y. Mechanized exploitation using modern dredges has succeeded in only two distinct localities: along the Jequitinhonha River (Diamantina) and at the Fazenda Camargo (Mato Grosso). Large diamonds of several hundred carats have been found periodically in the area of the municipalities of Abaeté and Coromandel in western Minas Gerais State. Carbonado, a polycrystalline variety of diamond, was intensively mined in several localities of the Chapada Diamantina in central Bahia State, mainly in the second half of the last century. Kimberlite-type rocks, on the other hand, were discovered only in the late 1960s, first in the Coromandel area in Minas Gerais and later in Goiás, Mato Grosso, Rondônia and Piauí States. Little is yet known about these intrusions, mainly because the discoveries have been made by foreign companies operating in the country. Detailed studies reported during the Kimberlite Conference of Araxá in 1991 revealed that some intrusions of the Coromandel area have mineralogical and petrographical characteristics, as well as major chemical element compositions, similar to worldwide kimberlites. However, their isotopic signatures in terms of Sr and Nd are intermediate between Groups I and II kimberlites of South Africa. As to mineral inclusions, Brazilian diamonds contain the common phases of olivine, garnets, pyroxenes, sulphides and oxides as observed in diamonds elsewhere. Furthermore, diamonds from the São Luis River in northern Mato Grosso contain, in addition to garnet and pyroxene, periclase, ferripericlase, w

  20. Nuclear magnetic resonance of external protons using continuous dynamical decoupling with shallow NV centers

    NASA Astrophysics Data System (ADS)

    de Las Casas, Charles; Ohno, Kenichi; Awschalom, David D.


    The nitrogen vacancy (NV) center in diamond is a paramagnetic defect with excellent spin properties that can reside within a few nanometers of the diamond surface, enabling atomic-scale magnetic resonance sensing of external nuclear spins. Here we use rotating frame longitudinal spin relaxation (T1ρ) based sensing schemes, known as Continuous Dynamical Decoupling (CDD), to detect external nuclear spins with shallow NV centers (<5 nm from the surface). Distinguishing neighboring nuclear spins from each other requires the NV center be near enough to create differences in the hyperfine shifts and coupling strengths of the nuclei. However, spin coherence time and consequently the sensitivity of dynamical decoupling techniques degrade sharply as NVs become shallower. We use strong continuous driving to overcome this fast decoherence and detect an ensemble of external nuclear spins using a single shallow NV center with a short T2 (<2 μs) at magnetic fields as high as 0.5 Tesla. The increased sensitivity of this method relative to pulsed dynamical decoupling techniques demonstrates the benefits of CDD for sensing with very shallow NV centers. This work was supported by DARPA, AFOSR, and the DIAMANT program.

  1. Multistage adsorption of diffusing macromolecules and viruses

    NASA Astrophysics Data System (ADS)

    Chou, Tom; D'Orsogna, Maria R.


    We derive the equations that describe adsorption of diffusing particles onto a surface followed by additional surface kinetic steps before being transported across the interface. Multistage surface kinetics occurs during membrane protein insertion, cell signaling, and the infection of cells by virus particles. For example, viral entry into healthy cells is possible only after a series of receptor and coreceptor binding events occurs at the cellular surface. We couple the diffusion of particles in the bulk phase with the multistage surface kinetics and derive an effective, integrodifferential boundary condition that contains a memory kernel embodying the delay induced by the surface reactions. This boundary condition takes the form of a singular perturbation problem in the limit where particle-surface interactions are short ranged. Moreover, depending on the surface kinetics, the delay kernel induces a nonmonotonic, transient replenishment of the bulk particle concentration near the interface. The approach generalizes that of Ward and Tordai [J. Chem. Phys. 14, 453 (1946)] and Diamant and Andelman [Colloids Surf. A 183-185, 259 (2001)] to include surface kinetics, giving rise to qualitatively new behaviors. Our analysis also suggests a simple scheme by which stochastic surface reactions may be coupled to deterministic bulk diffusion.

  2. Earthquake evidence for along-arc extension in the Mariana Islands

    NASA Astrophysics Data System (ADS)

    Heeszel, David S.; Wiens, Douglas A.; Shore, Patrick J.; Shiobara, Hajime; Sugioka, Hiroko


    Analysis of data from a deployment of ocean bottom and land seismographs in 2003-2004 detected four swarms of earthquakes in the overriding plate of the Mariana subduction system between the fore-arc and the back-arc spreading center. Two additional shallow swarms were identified by analyzing the teleseismic earthquake catalogs from 1967 to 2003. Focal mechanism solutions for these swarms, determined from regional waveform inversion for the 2003-2004 events or retrieved from the Centroid Moment Tensor catalog for previous years, suggest a complex system of deformation throughout the arc. We observe arc-parallel extension near volcanic cross chains, arc-perpendicular extension along the frontal arc, and arc-parallel compression farther into the back arc near the Mariana Trough. A swarm beneath the middle and eastern summits of the Diamante cross chain may have recorded magmatic activity. Volcanic cross chains showing evidence of adiabatic decompression melting from extensional upwelling are localized at regions of enhanced along-strike extension. The earthquake data are consistent with recent GPS results indicating 12 mm/a of extension between Guam and Agrihan. The along-arc extension may result from either increasing curvature of the Mariana system with time or from deformation induced by oblique subduction in the northernmost and southernmost regions of the arc.

  3. High-spin structure of {sup 102}Ru

    SciTech Connect

    Sohler, D.; Timar, J.; Molnar, J.; Dombradi, Zs.; Krasznahorkay, A.; Zolnai, L.; Rainovski, G.; Joshi, P.; Wadsworth, R.; Jenkins, D.G.; Raddon, P.M.; Simons, A.J.; Wilkinson, A.R.; Starosta, K.; Fossan, D.B.; Koike, T.; Vaman, C.; Algora, A.; Bednarczyk, P.; Curien, D.


    High-spin states in the nucleus {sup 102}Ru have been investigated via the {sup 96}Zr({sup 13}C,{alpha}3n) reaction at beam energies of 51 and 58 MeV, using the euroball IV {gamma}-ray spectrometer and the diamant charged particle array. Several new high-spin bands have been established. The ground-state band has been extended up to E{sub x}{approx}12 MeV with I{sup {pi}}=(26{sup +}); the previously published negative-parity bands have been extended up to E{sub x}{approx}11 and {approx} 9 MeV with I{sup {pi}}=(23{sup -}) and (20{sup -}), respectively. The deduced high-spin structure has been compared with Woods-Saxon total Routhian surface calculations and, on the basis of the measured Routhians, aligned angular momenta, and B(M1)/B(E2) ratios, {nu}h{sub 11/2}(g{sub 7/2},d{sub 5/2}) configurations are suggested for the negative-parity structures.

  4. Explorations of Mariana Arc Volcanoes Reveal New Hydrothermal Systems

    NASA Astrophysics Data System (ADS)

    Embley, R. W.; Baker, E. T.; Chadwick, W. W., Jr.; Lupton, J. E.; Resing, J. A.; Massoth, G. J.; Nakamura, K.


    Some 20,000 km of volcanic arcs, roughly one-third the length of the global mid-ocean ridge (MOR) system, rim the western Pacific Ocean. Compared to 25 years of hydrothermal investigations along MORs, exploration of similar activity on the estimated ~600 submarine arc volcanoes is only beginning [Ishibashi and Urabe, 1995; De Ronde et al., 2003]. To help alleviate this under-sampling, the R/V T. G. Thompson was used in early 2003 (9 February to 5 March) to conduct the first complete survey of hydrothermal activity along 1200 km of the Mariana intra-oceanic volcanic arc. This region includes both the Territory of Guam and the Commonwealth of the Northern Mariana Islands. The expedition mapped over 50 submarine volcanoes with stunning new clarity (Figures 1 and 2) and found active hydrothermal discharge at 12 sites, including the southern back-arc site. This includes eight new sites along the arc (West Rota, Northwest Rota, E. Diamante, Zealandia Bank, Maug Caldera, Ahyi, Daikoku, and Northwest Eifuku) and four sites of previously known hydrothermal activity (Seamount X, Esmeralda, Kasuga 2, and Nikko) (Figures 1 and 2). The mapping also fortuitously provided a ``before'' image of the submarine flanks of Anatahan Island, which had its first historical eruption on 10 May 2003 (Figures 1 and 3).

  5. Engineered diamond nanopillars as mobile probes for high sensitivity metrology in fluid

    NASA Astrophysics Data System (ADS)

    Andrich, P.; de Las Casas, C. F.; Heremans, F. J.; Awschalom, D. D.; Aleman, B. J.; Ohno, K.; Lee, J. C.; Hu, E. L.


    The nitrogen-vacancy (NV) center`s optical addressability and exceptional spin coherence properties at room temperature, along with diamond`s biocompatibility, has put this defect at the frontier of metrology applications in biological environments. To push the spatial resolution to the nanoscale, extensive research efforts focus on using NV centers embedded in nanodiamonds (NDs). However, this approach has been hindered by degraded spin coherence properties in NDs and the lack of a platform for spatial control of the nanoparticles in fluid. In this work, we combine the use of high quality diamond membranes with a top-down patterning technique to fabricate diamond nanoparticles with engineered and highly reproducible shape, size, and NV center density. We obtain NDs, easily releasable from the substrate into a water suspension, which contain single NV centers exhibiting consistently long spin coherence times (up to 700 μs). Additionally, we demonstrate highly stable, three-dimensional optical trapping of the nanoparticles within a microfluidic circuit. This level of control enables a bulk-like DC magnetic sensitivity and gives access to dynamical decoupling techniques on contactless, miniaturized diamond probes. This work was supported by DARPA, AFOSR, and the DIAMANT program.

  6. The memory of iron stress in strawberry plants.


    Gama, Florinda; Saavedra, Teresa; da Silva, José Paulo; Miguel, Maria Graça; de Varennes, Amarilis; Correia, Pedro José; Pestana, Maribela


    To provide information towards optimization of strategies to treat Fe deficiency, experiments were conducted to study the responses of Fe-deficient plants to the resupply of Fe. Strawberry (Fragaria × ananassa Duch.) was used as model plant. Bare-root transplants of strawberry (cv. 'Diamante') were grown for 42 days in Hoagland's nutrient solutions without Fe (Fe0) and containing 10 μM of Fe as Fe-EDDHA (control, Fe10). For plants under Fe0 the total chlorophyll concentration of young leaves decreased progressively on time, showing the typical symptoms of iron chlorosis. After 35 days the Fe concentration was 6% of that observed for plants growing under Fe10. Half of plants growing under Fe0 were then Fe-resupplied by adding 10 μM of Fe to the Fe0 nutrient solution (FeR). Full Chlorophyll recovery of young leaves took place within 12 days. Root ferric chelate-reductase activity (FCR) and succinic and citric acid concentrations increased in FeR plants. Fe partition revealed that FeR plants expressively accumulated this nutrient in the crown and flowers. This observation can be due to a passive deactivation mechanism of the FCR activity, associated with continuous synthesis of succinic and citric acids at root level, and consequent greater uptake of Fe.

  7. The compression of a heavy floating elastic film.


    Jambon-Puillet, Etienne; Vella, Dominic; Protière, Suzie


    We study the effect of film density on the uniaxial compression of thin elastic films at a liquid-fluid interface. Using a combination of experiments and theory, we show that dense films first wrinkle and then fold as the compression is increased, similarly to what has been reported when the film density is neglected. However, we highlight the changes in the shape of the fold induced by the film's own weight and extend the model of Diamant and Witten [Phys. Rev. Lett., 2011, 107, 164302] to understand these changes. In particular, we suggest that it is the weight of the film that breaks the up-down symmetry apparent from previous models, but elusive experimentally. We then compress the film beyond the point of self-contact and observe a new behaviour dependent on the film density: the single fold that forms after wrinkling transitions into a closed loop after self-contact, encapsulating a cylindrical droplet of the upper fluid. The encapsulated drop either causes the loop to bend upward or to sink deeper as the compression is increased, depending on the relative buoyancy of the drop-film combination. We propose a model to qualitatively explain this behaviour. Finally, we discuss the relevance of the different buckling modes predicted in previous theoretical studies and highlight the important role of surface tension in the shape of the fold that is observed from the side-an aspect that is usually neglected in theoretical analyses.

  8. Hydrodynamic interactions between two forced objects of arbitrary shape. II. Relative translation

    NASA Astrophysics Data System (ADS)

    Goldfriend, Tomer; Diamant, Haim; Witten, Thomas A.


    We study the relative translation of two arbitrarily shaped objects, caused by their hydrodynamic interaction as they are forced through a viscous fluid in the limit of zero Reynolds number. It is well known that in the case of two rigid spheres in an unbounded fluid, the hydrodynamic interaction does not produce relative translation. More generally, such an effective pair-interaction vanishes in configurations with spatial inversion symmetry; for example, an enantiomorphic pair in mirror image positions has no relative translation. We show that the breaking of inversion symmetry by boundaries of the system accounts for the interactions between two spheres in confined geometries, as observed in experiments. The same general principle also provides new predictions for interactions in other object configurations near obstacles. We examine the time-dependent relative translation of two self-aligning objects, extending the numerical analysis of our preceding publication [Goldfriend, Diamant, and Witten, Phys. Fluids 27, 123303 (2015)], 10.1063/1.4936894. The interplay between the orientational interaction and the translational one, in most cases, leads over time to repulsion between the two objects. The repulsion is qualitatively different for self-aligning objects compared to the more symmetric case of uniform prolate spheroids. The separation between the two objects increases with time t as t1 /3 in the former case, and more strongly, as t , in the latter.

  9. A comparative study on tribological behavior between metal and polymeric composites used to repair bronze made parts in dry reciprocating sliding tests

    NASA Astrophysics Data System (ADS)

    Iliuţă, V.; Rîpă, M.; Javorova, J.; Andrei, G.


    The paper presents the researches on tribological behaviour of two materials used for parts subjected to friction, under dry sliding conditions. The composite material is a product of the company Diamant Metallplastic GmbH, Germany and the manufacturer recommend it for repairing or reconditioning worn or damaged bronze made parts. The material belongs to Multimetall category, which is a highly resistant 2-component repair system. This polymer composite material was tribologically tested in dry friction reciprocating conditions, in ball-on-flat configuration, using the tribometer UMT-2 (Bruker, former CETR). The counterpiece was a steel ball. Typical test conditions were as follows: normal loads of 20, 30, 40 and 50 N, sliding distance of 100 m, stroke length of 5mm, average sliding speed of 3,5 mm/s, room temperature and relative humidity of 50-60%. After testing, wear tracks were examined by electronic microscopy (SEM), laser profilometry and the profilometric module of the tribometer CETR-UMT-2. The results of the composite material analysis were compared with the similar ones obtained under similar test conditions for the bronze (metal material).

  10. Dero (Allodero) lutzi Michaelsen, 1926 (Oligochaeta: Naididae) associated with Scinax fuscovarius (Lutz, 1925) (Anura: Hylidae) from Semi-deciduous Atlantic Rain Forest, southern Brazil.


    Oda, F H; Petsch, D K; Ragonha, F H; Batista, V G; Takeda, A M; Takemoto, R M


    Amphibians are hosts for a wide variety of ecto- and endoparasites, such as protozoans and parasitic worms. Naididae is a family of Oligochaeta whose species live on a wide range of substrates, including mollusks, aquatic macrophytes, sponges, mosses, liverworts, and filamentous algae. However, some species are known as endoparasitic from vertebrates, such as Dero (Allodero) lutzi, which is parasitic of the urinary tracts of frogs, but also have a free-living stage. Specimens in the parasitic stage lack dorsal setae, branchial fossa, and gills. Here we report the occurrence of D. (A.) lutzi associated with anuran Scinax fuscovarius from Semi-deciduous Atlantic Rain Forest in southern Brazil. The study took place at the Caiuá Ecological Station, Diamante do Norte, Paraná, southern Brazil. Seven specimens of S. fuscovarius were examined for parasites but only one was infected. Parasites occurred in ureters and urinary bladder. Previous records of this D. (A.) lutzi include the Brazilian States of Santa Catarina, São Paulo, Rio de Janeiro, and Minas Gerais, as well as Cuba and North America. This is a new locality record for this species in Brazil. Reports of Dero (Allodero) lutzi are rare, due to difficulty of observation, and such events are restricted only the fortuitous cases. It is important to emphasize the necessity of future studies, which are fundamental to the understanding of biological and ecological aspects of this species.

  11. Origin of Nanodiamonds in Primitive Chondrites: (1) Theory

    NASA Astrophysics Data System (ADS)

    Ozima, M.; Mochizuki, K.


    Microdiamonds in primitive chondrites are characterized by Xe-HL, which supposedly formed in a type II supernova. Several models have been proposed for the origin of the microdiamonds. These include chemical vapor deposition (CVD) [e.g., 1], interstellar shock [2], and UV-annealing of small graphite particles [3]. However, it is difficult for any of these models to explain the unique association of Xe-HL with the microdiamonds. We have suggested that a diamond formation process, proposed by Kaminsky [4], for the origin of a particular terrestrial diamond, carbonado, may apply to the microdiamonds in primitive meteorites [5,6]: Kaminsky speculated that carbonado was formed from natural coal that was enriched in uranium and hence subjected to irradiation by high-energy particles produced from the uranium and thorium. The paper in this volume by Mochizuki et al. [7] reports nanometer-sized diamondlike clusters in a uranium-rich natural coal, in accordance with Kaminsky's hypothesis. Mochizuki et al. also report the possibility of the production of nanodiamonds in graphite that was irradiated with a 50-KeV argon beam. These experimental studies strongly suggest that microdiamonds can be produced by irradiation of carbonaceous matters with energetic particles. On the basis of these experimental results, we propose a scenario for the origin of the microdiamonds in primitive chondrites. The scenario gives a reasonable explanation for the unique association of Xe-HL with the microdiamonds as well as for their formation in a supernova envelope. We assume that carbonaceous materials (amorphous carbon, graphite, and hydrocarbon grains) in the outer envelope of a supernova was irradiated by energetic particles (including Xe-HL) emitted during supernova explosion. The energetic particles then interacted with the carbonaceous matter: Most of the energy was dissipated through electronic interaction, and at the end of the journey the particles produced cascade displacement of

  12. Geology of quadrangles H-12, H-13, and parts of I-12 and I-13, (zone III) in northeastern Santander Department, Colombia

    USGS Publications Warehouse

    Ward, Dwight Edward; Goldsmith, Richard; Cruz, Jaime B.; Restrepo, Hernan A.


    Permian-Carboniferous Diamante Formation, sedimentary rocks younger than Devonian are unmetamorphosed. The effects of Precambrian regional dynamothermal metamorphism and plutonism on Precambrian geosynclinal deposits reached the upper amphibolite facies in the Bucaramanga Gneiss. The geosynclinal Silgara Formation was subjected to similar conditions in Late Ordovician and Early Silurian time but reached only the greenschist or lower amphibolite facies. Orthogneisses generally show a concordance of foliation and lineation with the neighboring Silgara Formation and the Bucaramanga Gneiss as well as similarities in grade of metamorphism. Regional dynamothermal metamorphism in Late Permian and Triassic time reached, low grade in the Floresta Formation and caused recrystallization of limestone of the Diamante Formation. The Bucaramanga and Silgara metamorphic rocks show evidence of metrogressive metamorphism accompanied by high activity or potassium and water, but whether this occurred at the time the Floresta was metamorphosed or later is not clear. Batholiths, plutons, and stocks of igneous rocks in the Santander massif range from diorite to granite. Radioactive age data indicate that most belong to a single plutonic interval. These are referred to as the Santander Plutoniq Group and are Jurassic and Jurassic-Triassic- Two suites of this group are pink granite and quartz monzonite, and gray quartz monzonite and granodiorite. Contact relations indicate that the pink and more granitic rocks are younger than the gray and more mafic rocks, but radioactive age data are in conflict with this. Undated plutonic rocks that are not clearly related to the group are assigned to relatively older or younger age positions. West of the Bucanamanga fault rhyolite makes up a small body at one locality and forms an intrusive sheet with granophyre and intrusive breccias in Triassic sedimentary rocks at another locality. Its age is unknown, but it probably is younger than the

  13. Mineral resources of the southern half of Zone III Santander, Norte de Santander and Boyaca, Colombia

    USGS Publications Warehouse

    Ward, Dwight Edward; Goldsmith, Richard; Cruz, Bruna B.; Restrepo, Jaime; Hernan, A.


    are being explored and sampled at the present time (1969). A little lead has been mined and smelted in the past but operations were on a very small scale and of short duration. Small amounts of lead, zinc, and copper minerals accompany dolomite replacement of Cretaceous limestone in a few scattered places, and several promising prospects are being investigated by means of trenches and drilling. One magnetite and several hematite prospects were examined but none offers any potential for economic development. Thick beds of gypsum in Lower Cretaceous limestone on Mesa de Los Santos, south of Bucaramanga are being quarried from outcrops for use in cement manufacture. The deposit was discovered shortly before the present project began, and although its extent beneath overlying strata is not yet determined by drilling, it appears to be in a small evaporite basin of about three kilometers in radius. Reserves of gypsum are large, but future development will have to be by underground mining. Outcrops of Cretaceous limestone of high purity are widespread and are more than adequate to meet all demands, which at present are for cement and calcined lime, road construction material, and to a small extent for agricultural lime and polished decorative stone. Upper Paleozoic limestone of the Diamante Formation crops out in a few places; it has been used near Bucaramanga for cement manufacture. Marble is present in several localities of the Santander massif in Lower Paleozoic and Devonian rocks. Impurities, fractures, and solution cavities render most of it unsuitable for decorative purposes, but selected parts are used in floor tile and terrazo. Recrystallized limestone of the Diamante Formation in the same area, usually referred to as marble, is of uniform high purity throughout a thick and uninterrupted section, and offers a good source of limestone raw material. A little is now used for agricultural lime. The potential of this resource has not been fully evalua

  14. Thin layer drying of tomato slices.


    Das Purkayastha, Manashi; Nath, Amit; Deka, Bidyut Chandra; Mahanta, Charu Lata


    The hot air convective drying characteristics of blanched tomato (Lycopersicon esculantum L.) slices have been investigated. Drying experiments were carried out at four different temperatures (50, 60, 65 and 70 °C). The effect of drying temperatures on the drying behavior of the tomato slices was evaluated. All drying experiments had only falling rate period. The average effective diffusivity values varied from 0.5453 × 10(-9) to 2.3871 × 10(-9) m(2)/s over the temperature range studied and the activation energy was estimated to be 61.004 kJ/mol. In order to select a suitable form of the drying curve, six different thin layer drying models (Henderson-Pabis, Page, Diamante et al., Wang and Singh, Logarithmic and Newton models) were fitted to the experimental data. The goodness of fit tests indicated that the Logarithmic model gave the best fit to experimental results, which was closely followed by the Henderson-Pabis model. The influence of varied drying temperatures on quality attributes of the tomato slices viz. Hunter color parameters, ascorbic acid, lycopene, titratable acidity, total sugars, reducing sugars and sugar/acid ratio of dried slices was also studied. Slices dried at 50 and 60 °C had high amount of total sugars, lycopene, sugar/acid ratio, Hunter L- and a-values. Drying of slices at 50 °C revealed optimum retention of ascorbic acid, sugar/acid ratio and red hue, whereas, drying at higher temperature (65 and 70 °C) resulted in a considerable decrease in nutrients and colour quality of the slices.

  15. Biplot analysis of strawberry genotypes recommended for the State of Espírito Santo.


    Costa, A F; Teodoro, P E; Bhering, L L; Leal, N R; Tardin, F D; Daher, R F


    Most strawberry genotypes grown commercially in Brazil originate from breeding programs in the United States, and are therefore not adapted to the various soil and climatic conditions found in Brazil. Thus, quantifying the magnitude of genotype x environment (GE) interactions serves as a primary means for increasing average Brazilian strawberry yields, and helps provide specific recommendations for farmers on which genotypes meet high yield and phenotypic stability thresholds. The aim of this study was to use AMMI (additive main effects and multiplicative interaction) and GGE biplot (genotype main effects + genotype x environment interaction) analyses to identify high-yield, stable strawberry genotypes grown at three locations in Espírito Santo for two agricultural years. We evaluated seven strawberry genotypes (Dover, Camino Real, Ventana, Camarosa, Seascape, Diamante, and Aromas) at three locations (Domingos Martins, Iúna, and Muniz Freire) in agricultural years 2006 and 2007, totaling six study environments. Joint analysis of variance was calculated using yield data (t/ha), and AMMI and GGE biplot analysis was conducted following the detection of a significant genotypes x agricultural years x locations (G x A x L) interaction. During the two agricultural years, evaluated locations were allocated to different regions on biplot graphics using both methods, indicating distinctions among them. Based on the results obtained from the two methods used in this study to investigate the G x A x L interaction, we recommend growing the Camarosa genotype for production at the three locations assessed due to the high frequency of favorable alleles, which were expressed in all localities evaluated regardless of the agricultural year.

  16. Effects of gymnemic acid on the chorda tympani proper nerve responses to sweet, sour, salty and bitter taste stimuli in the chimpanzee.


    Hellekant, G; af Segerstad, C H; Roberts, T; van der Wel, H; Brouwer, J N; Glaser, D; Haynes, R; Eichberg, J W


    In man gymnemic acid is able to abolish the sweet taste. Also in man, the neural correlate of that effect is a disappearance of the response to sweet stimuli in the taste nerves, as indicated by the observations of Diamant et al. (1965). Although a variety of other mammals also show neural responses to sweet-tasting compounds, the corresponding effect of gymnemic acid has not been demonstrated. This study presents chorda tympani proper nerve recordings from the chimpanzee before and after gymnemic acid. On the chimpanzee tongue, application of 2 ml gymnemic acid (3-10 mg X ml-1 for 3-4 min) completely abolished the taste responses to 0.0035 M acesulfam-K, 0.0018 M aspartame, 0.015 M D-tryptophan, 0.02% monellin, and 0.02% thaumatin, reduced by 75% the response to 0.3 M sucrose, and by 50% that of 0.76 M xylitol. No decrease was recorded in the responses to 0.001 M quinine, 0.1 M NaCl, 0.02 and 0.04 M ascorbic acid, 0.02 and 0.04 M citric acid. The response to the sweeteners recovered with time and the recovery was complete or nearly complete after one and a half hours. It was also found that after application of 2 ml miraculin, 3 mg X ml-1 for 3 min to the tongue the neural response to acids was about 1.5 times as large as before. Gymnemic acid applied before miraculin prevented this enhancement and gymnemic acid after miraculin depressed the enhancement by miraculin of the response to citric and ascorbic acid.

  17. [Rapid identification of potato cultivars using NIR-excited fluorescence and Raman spectroscopy].


    Dai, Fen; Bergholt, Mads Sylvest; Benjamin, Arnold Julian Vinoj; Hong, Tian-Sheng; Zhiwei, Huang


    Potato is one of the most important food in the world. Rapid and noninvasive identification of potato cultivars plays a important role in the better use of varieties. In this study, The identification ability of optical spectroscopy techniques, including near-infrared (NIR) Raman spectroscopy and NIR fluorescence spectroscopy, for invasive detection of potato cultivars was evaluated. A rapid NIR Raman spectroscopy system was applied to measure the composite Raman and NIR fluorescence spectroscopy of 3 different species of potatoes (98 samples in total) under 785 nm laser light excitation. Then pure Raman and NIR fluorescence spectroscopy were abstracted from the composite spectroscopy, respectively. At last, the partial least squares-discriminant analysis (PLS-DA) was utilized to analyze and classify Raman spectra of 3 different types of potatoes. All the samples were divided into two sets at random: the calibration set (74samples) and prediction set (24 samples), the model was validated using a leave-one-out, cross-validation method. The results showed that both the NIR-excited fluorescence spectra and pure Raman spectra could be used to identify three cultivars of potatoes. The fluorescence spectrum could distinguish the Favorita variety well (sensitivity: 1, specificity: 0.86 and accuracy: 0.92), but the result for Diamant (sensitivity: 0.75, specificity: 0.75 and accuracy: 0. 75) and Granola (sensitivity: 0.16, specificity: 0.89 and accuracy: 0.71) cultivars identification were a bit poorer. We demonstrated that Raman spectroscopy uncovered the main biochemical compositions contained in potato species, and provided a better classification sensitivity, specificity and accuracy (sensitivity: 1, specificity: 1 and accuracy: 1 for all 3 potato cultivars identification) among the three types of potatoes as compared to fluorescence spectroscopy.

  18. Geochronology, Nd isotopes and reconnaissance geochemistry of volcanic and metavolcanic rocks of the São Luís Craton, northern Brazil: Implications for tectonic setting and crustal evolution

    NASA Astrophysics Data System (ADS)

    Klein, Evandro L.; Luzardo, Renê; Moura, Candido A. V.; Lobato, Denise C.; Brito, Reinaldo S. C.; Armstrong, Richard


    New field work, in addition to zircon geochronology, Nd isotopes and reconnaissance geochemical data allow the recognition of Paleoproterozoic volcanic and metavolcanic sequences in the São Luís Craton of northern Brazil. These sequences record at least five volcanic pulses occurring probably in three distinct epochs and in different tectonic settings. (1) The Pirocaua Formation of the Aurizona Group comprises early arc-related calc-alkaline metapyroclastic rocks of 2240 ± 5 Ma formed from juvenile protoliths in addition to minor older crustal components. (2) The Matará Formation of the Aurizona Group holds mafic tholeiitic and ultramafic metavolcanic rocks of back arc and/or island arc setting, which are likely coeval to the Pirocaua Formation. (3) The Serra do Jacaré volcanic unit is composed of tholeiitic basalts and predominantly metaluminous, normal- to high- K calc-alkaline andesites of 2164 ± 3 Ma formed in mature arc or active continental margin from juvenile protoliths along with subordinate older (Paleoproterozoic) materials and associated to the main calc-alkaline orogenic stage. (4) The Rio Diamante Formation consists of late-orogenic metaluminous, medium- K, calc-alkaline rhyolite to dacite and tuffs of 2160 ± 8 Ma formed in continental margin setting from reworked Paleoproterozoic crust (island arc) with incipient Archean contribution. (5) The Rosilha volcanic unit is composed of weakly peraluminous, medium- K, calc-alkaline dacite and tuff formed probably at about 2068 Ma from reworked crustal protoliths. As a whole the volcanic and metavolcanic rocks record and characterized better the previously proposed orogenic evolution of the São Luís Craton.

  19. Community Exposure to Lahar Hazards from Mount Rainier, Washington

    USGS Publications Warehouse

    Wood, Nathan J.; Soulard, Christopher E.


    dependent-population facilities (for example, schools and child day-care centers), public venues (for example, religious organizations and hotels), and critical facilities (for example, police and fire stations). The lahar-hazard zone also includes high-volume tourist sites, such as Mount Rainier National Park and the Puyallup Fairgrounds. Community exposure to lahars associated with Mount Rainier varies considerably among 27 communities and four counties - some may experience great losses that reflect only a small portion of their community and others may experience relatively small losses that devastate them. Among 27 communities, the City of Puyallup has the highest number of people and assets in the lahar-hazard zone, whereas the communities of Carbonado, Fife, Orting, and Sumner have the highest percentages of people and assets in this zone. Based on a composite index, the cities of Puyallup, Sumner, and Fife have the highest combinations of the number and percentage of people and assets in lahar-prone areas.

  20. Tectonic Activity and Processes Preceding the Formation of the Dead Sea Fault Zone

    NASA Astrophysics Data System (ADS)

    Eppelbaum, L. V.; Pilchin, A. N.


    and 530 Ma, point to a huge release of heat likely caused by friction during the thrusting. Presence of giant quantities of K-rich granites also points to reworking of continental crust in the region. Small amount of magmatic formations younger than Cambrian age west of DSFZ and significant amount of magmatic formations of this period east of DSFZ also indicate to presence of the plate beneath Israel. Offset of suture zones within AS shows that displacement was maximal for the northern blocks of AS. This is in agreement with known separation of Israel's crust into three blocks: Negev, Judea-Samaria and Galilee- Lebanon. Numerous markers of high to ultra-high pressure conditions signify to collision between the AP and the PM. These markers are: iron rich aegerine-augite and olivine-rich phenocrysts in S. Israel; peridotite xenoliths in S. Israel equilibrated at depth ~33-34 km; discovery of diamonds, micro-diamonds and indicator minerals (Cr- diopside, orange garnet, pyrope, coesite, picroilmenite, moissanite, carbonado, corundum, olivine, perovskite, aegerine, Ti-augite) in S. Israel; garnet clinopyroxenites, garnet granulites, indicator minerals, and eclogite-like rocks in Mt. Carmel area of N. Israel; iron-rich garnets in Sinai; eclogites, diamonds and indicator minerals in non-kimberlite environments in Syria; ophiolites exposed in Syria at northern extension of the DSFZ; ophiolite-like rocks in Sinai. These markers are located along or in close proximity to the DSFZ. Different isostatic conditions east of the edge of- and above- the underlying plate, along with the eventual activation of the plate caused the later formation of the DSFZ.

  1. Pleistocene glaciation of volcano Ajusco, central Mexico, and comparison with the standard Mexican glacial sequence

    NASA Astrophysics Data System (ADS)

    White, Sidney E.; Valastro, Salvatore


    Three Pleistocene glaciations and two Holocene Neoglacial advances occurred on volcano Ajusco in central Mexico. Lateral moraines of the oldest glaciation, the Marqués, above 3250 m are made of light-gray indurated till and are extensively modified by erosion. Below 3200 m the till is dark red, decomposed, and buried beneath volcanic colluvium and tephra. Very strongly to strongly developed soil profiles (Inceptisols) have formed in the Marqués till and in overlying colluvia and tephra. Large sharp-crested moraines of the second glaciation, the Santo Tomás, above 3300 m are composed of pale-brown firm till and are somewhat eroded by gullies. Below 3250 m the till is light reddish brown, cemented, and weathered. Less-strongly developed soil profiles (Inceptisols) have formed in the Santo Tomás till and in overlying colluvia and tephra. Narrow-crested moraines of yellowish-brown loose till of the third glaciation, the Albergue, are uneroded. Weakly developed soil profiles (Inceptisols) in the Albergue till have black ash in the upper horizon. Two small Neoglacial moraines of yellowish-brown bouldery till on the cirque floor of the largest valley support weakly developed soil profiles with only A and Cox horizons and no ash in the upper soil horizons. Radiocarbon dating of organic matter of the B horizons developed in tills, volcanic ash, and colluvial volcanic sand includes ages for both the soil-organic residue and the humic-acid fraction, with differences from 140 to 660 yr. The dating provides minimum ages of about 27,000 yr for the Marqués glaciation and about 25,000 yr for the Santo Tomás glaciation. Dates for the overlying tephra indicate a complex volcanic history for at least another 15,000 yr. Comparison of the Ajusco glacial sequence with that on Iztaccíhuatl to the east suggests that the Marqués and Santo Tomás glaciations may be equivalent to the Diamantes glaciation First and Second advances, the Albergue to the Alcalican glaciations, and the

  2. Geothermal resources in Martinique (Lesser Antilles): new insight of geochemical isotopic tools

    NASA Astrophysics Data System (ADS)

    Gadalia, A.; Rad, S.; Braibant, G.; Brach, M.; Millot, R.; Traineau, H.


    Geothermal exploration of Martinique Island started in 1967 but was interrupted successively at 3 times. Additional geothermal exploration program was conducted by BRGM, in 2001-2003 and recently in areas known for their geothermal interest: Mount Pelée volcano and Diamant. A complementary exploration is now proceed with new sites of interest such as "Pitons du Carbet" massif after recent dating (Germa et al., 2011). A conceptual model of reservoir was established for Mount Pelée volcano and on the Piton du Carbet massif, but the extension of these greenfield remains unknown. We propose new approach through geochemistry by the integration to the prospection of chemical compositions of river waters adding to hot springs and well waters. Rivers catchment in Lesser Antilles and their hydrothermal impact have been studied in order to quantify and identify the magmatic contribution into the river (Rad et al., 2011). Chemical analyses and new isotopic tools such as Lithium isotopes 7Li/6Li (expressed as δ7Li) are measured in river waters. Among these multi chemical parameters, isotopic in particular (H, Li, C, O, Sr…) the Li isotopic signature appear to be conservative and allows to identify new target with high temperature water-rock interactions or in case of high fractionation, reflecting low temperature water-rock interactions, to avoid an extended zone. These new technique was applied to the Mount Pelée and confirm the pre-existent model established in previous exploration campaign. For Pitons du Carbet massif all the river catchment of the massif have been sampled, first results show a potential western extension of the reservoir, confirm by an important gas leak of hydrothermal origin. For tropical volcanic environment with sharp relief, dense vegetation, and high precipitation, chemical and isotopic analyses, particularly lithium isotopes, in river waters, allow to identify zone of interest. To conclude, river catchment studies dedicate to geothermal

  3. Evolução química de galáxias HII anãs

    NASA Astrophysics Data System (ADS)

    Ferraresi, M., Jr.; Cuisinier, F.; Telles, E.


    Galáxias HII anãs são galáxias de baixa massa, com alto conteúdo de gás, e se encontram em uma fase intensa de formação estelar. A taxa de formação estelar está tão alta nestas galáxias que não pode ter se mantido durante sua vida inteira. O tempo máximo de duração do episódio atual de formação estelar deve ser no máximo de algumas dezenas de milhões de anos, bem inferior à idade destas galáxias. Isto leva naturalmente a idéia de que já aconteceram surtos anteriores. Abundâncias químicas oferecem uma ferramenta poderosa para investigar a história evolutiva destas galáxias, porque aumentam de geração em geração estelar. O hidrogênio, o oxigênio, o nitrogênio produzem algumas das linhas mais importantes em um gás foto-ionizado, permitindo a determinação das abundâncias destes elementos facilmente. A dispersão das abundâncias em oxigênio e nitrogênio é significativa, sendo maior que os erros observacionais. O oxigênio é produzido em estrelas massivas, que explodem quase instâneamente, enquanto o nitrogênio é produzido em estrelas de massa intermediária, que só o liberam depois de um atraso de @ 500 mihões de anos. Construímos um modelo de evolução química semi-analítico, utilizando rendimentos empíricos baseados nas abundâncias observadas destes dois elementos. Conseguimos através deste modelo rudimentar explicar nas galáxias de mais baixas metalicidades as abundâncias de oxigênio e de nitrogênio, assim como a dispersão dos dados observacionais devida a formação estelar descontínua, e isto com um número baixo de surtos (1 ou 2, no máximo 3).

  4. Lb2 satellites spectra emitted due to N - shell spectator vacancy

    NASA Astrophysics Data System (ADS)

    Poonia, Surendra


    , only six transitions superpose to give rise to this satellite, which has been named as b20, in case of elements with Z > 70, in the literature. In the range Z > 65, this satellite gets an added intensity due to the superposition of some intense transitions 2p-14f-1-4d-14f-1 array. This superposition of two arrays in high Z elements justifies the name b20 different from b2(a), given to the analogously placed satellite in the spectra of lower Z elements. Finally, the four closely spaced satellites, reported in the b2 region of the spectrum 46Pd have been assigned to suitable 2p-14x-1-4x-14d-1 (x = s, p, d) transitions. REFERENCES: 1.Y. Cauchois and C. Senemaud, X-Ray wavelength Tables, 2nd ed., (Oxford: Pergamon) pp. 217-314, (1978). 2.S. N. Soni and M. H. Massoud, J. Phys. Chem. Solids 58(1), 145-151 (1997). 3.S. N. Soni and S. Poonia, J. Phys. Chem. Solids 61(9), 1509-1518 (2000). 4.S. Poonia and S. N. Soni, J. Phys. Chem. Solids 62(3), 503-511 (2001). 5.A. M. Vlaicu, T. Tochio, T. Ishizuka, D. Ohsawa, Y. Ito, T. Mukoyama, A. Nisawa, T. Shoji and S. Yoshikado, Phys. Rev. A 58(5), 3544-3551, (1998). 6.R. Diamant, S. Huotari, K. Hamalainen, R. Sharon, C. C. Kao and M. Deutsch, Phys. Rev. A 63(2), 2508-2513 (2001).

  5. Fabrication de transistors monoelectroniques pour la detection de charge

    NASA Astrophysics Data System (ADS)

    Richard, Jean-Philippe

    'averent quasi identiques a celles calculees en conception. Les mesures electriques a basse temperature de SET fabriques demontrent un blocage de Coulomb avec une energie de charge de 10 meV et une temperature d'operation maximale de 10 K. Un effet de grille est aussi observe par l'application d'une tension sur la grille laterale et les electrodes d'un SET a proximite. Les parametres extraits a partir du diamant de Coulomb sont en accord avec les geometries du transistor fabrique, a l'exception de la capacite degrille et de couplage. Enfin, l'etude de la detection de charge est realisee par simulation a partir de ces parametres. Elle permet de conclure que la detection de charge peut etre optimisee en augmentant les surfaces de couplage de l'electrometre. Mots-cles : detection de charge, electrometre, transistor monoelectronique, nanodamascene, nanoelectronique, informatique quantique

  6. Application of multi-dimensional discrimination diagrams and probability calculations to Paleoproterozoic acid rocks from Brazilian cratons and provinces to infer tectonic settings

    NASA Astrophysics Data System (ADS)

    Verma, Sanjeet K.; Oliveira, Elson P.


    studies on Cassiterita-Tabuões, Ritápolis, São Tiago-Rezende Costa (south of São Francisco craton, Minas Gerais) showed a collision setting, which agrees fairly reasonably with a syn-collision tectonic setting indicated in the literature. A within-plate setting is suggested for the Serrinha magmatic suite, Mineiro belt (south of São Francisco craton, Minas Gerais), contrasting markedly with the arc setting suggested in the literature. The ninth case study on Rio Itapicuru granites and Rio Capim dacites (north of São Francisco craton, Serrinha block, Bahia) showed a continental arc setting. The tenth case study indicated within-plate setting for Rio dos Remédios volcanic rocks (São Francisco craton, Bahia), which is compatible with these rocks being the initial, rift-related igneous activity associated with the Chapada Diamantina cratonic cover. The eleventh, twelfth and thirteenth case studies on Bom Jesus-Areal granites, Rio Diamante-Rosilha dacite-rhyolite and Timbozal-Cantão granites (São Luís craton) showed continental arc, within-plate and collision settings, respectively. Finally, the last two case studies, fourteenth and fifteenth showed a collision setting for Caicó Complex and continental arc setting for Algodões (Borborema province).

  7. Mantle Inputs to the Subduction Factory: Detailed Studies of the Southern Mariana Seamount Province

    NASA Astrophysics Data System (ADS)

    Bloomer, S. H.; Stern, R. J.


    The southern Mariana Arc system has been studied intensively, with a focus on volcanoes along the magmatic arc and associated cross-chains. Sonar back-scatter imagery of about 50,000 square kilometers imaged 28 submarine volcanoes of the Mariana arc system that had not been previously studied. We also imaged the spreading axis of the Mariana Trough from 13o45' to 17 o 30', about half the length of this slow-spreading ridge. Our survey of 450 km along the arc magmatic axis, from 13 o 30'N to 17 o 20'N, indicates that these volcanoes vary widely in volume, from a third to 1000 km3. The average volcano from along the Mariana magmatic front is spaced 20km from its neighbor, is built on a platform that lies at 1800m below sealevel, rises 1000m above this platform, and occupies a volume of about 200 cubic kilometers. Lavas collected from 24 edifices along the magmatic front include abundant basalt and dacite; we also collected several cumulate gabbroic xenoliths. Phenocryst phases are dominated by plagioclase, olivine, pyroxene, and hornblende. Five of the volcanoes in the study area - the islands of Guguan, Sarigan, and Anatahan, and the submarine edifices of S. Ruby and Esmeralda -are active. Other volcanoes are extinct, and our study shows that, to a first approximation, the smaller the edifice, the less likely it is to be active. Some extinct edifices have flat summits at depths that range from 40 to 300 m which are capped with coral, or, farther north in the study area, shelly material or carbonate sand. A major cross-chain of small volcanoes along 14 o 40'N was studied and sampled for the first time. These volcanoes yielded a range of lavas, from basalt to dacite. Volcanoes from another cross-chain, extending along 17 o 20'N latitude west of Guguan, yielded only basalt. Shorter cross-chains were also studied in the Diamantes and near Sarigan. We recovered abundant pumice from 6 volcanoes in the northernmost 100km of the arc and one volcano in the south. Each

  8. Gradientes de abundâncias em galáxias espirais

    NASA Astrophysics Data System (ADS)

    Dors, O. L.., Jr.; Copetti, M. V. F.


    Gradientes de abundâncias obtidos através de observações de regiões H II têm um papel importante no estudo de formação e evolução de galáxias espirais. Determinações diretas de abundâncias somente são obtidas quando linhas de emissão sensíveis à temperatura eletrônica (e.g., [O III]l4363) são detectadas. Infelizmente estas linhas são fracas ou não observadas em regiões H II de baixa excitação. Nestes casos métodos empíricos são utilizados para estimar as abundâncias químicas. Entretanto, diferentes métodos têm produzido diferentes estimativas de gradientes de abundâncias. Neste trabalho, nós construímos modelos de fotoionização com o objetivo de descrever diagramas de diagnósticos construídos com dados publicados de algumas galáxias espirais normais e barradas. Comparações entre nossas estimativas de abundâncias e de outros métodos mostram que quando não há acordo entre eles, nossos modelos superestimam as abundâncias de O/H e N/H por um fator de 0.3 dex em relação a estimativas diretas de abundâncias, e por fator de 0.2 dex em relação a outros métodos empíricos. A origem da produção de nitrogênio nas galáxias estudadas é discutida.

  9. Abundâncias de oxigênio e enxofre nas estrelas de tipo solar da vizinhança solar

    NASA Astrophysics Data System (ADS)

    Requeijo, F.; Porto de Mello, G. F.


    Alguns resultados sugerem que o Sol seja 58% mais abundante em oxigênio que o meio interestelar local. Esta anomalia parece estender-se para o carbono e o criptônio. Entre as possíveis explicações deste fenômeno estão: uma supernova de tipo II que tenha enriquecido a nebulosa protosolar, tornando-a superabundante em oxigênio; um episódio de infall de material pobre em metais sobre o disco Galático, diluindo o meio interestelar local ou uma migração dinâmica do Sol de uma órbita mais interna da Galáxia para sua posição atual. A escolha entre estes cenários exige o conhecimento preciso da abundância solar em relação às anãs G da vizinhança. Neste contexto, o oxigênio e enxofre, são elementos-chave por serem ambos produzidos pelas supernovas de tipo II, devendo portanto possuir o mesmo padrão de abundância. Este projeto visa esclarecer qual a posição do Sol na distribuição local de abundâncias de enxofre e oxigênio para uma amostra de estrelas de tipo solar com idades e metalicidades bem conhecidas. Para tal, analisamos espectros de alta resolução e alta relação sinal-ruído nas regiões espectrais de ll 6300, 7774 (O) e l8695 (S). Para o enxofre encontramos que o Sol parece ser uma estrela típica dentre as da vizinhança, e que este elemento não mostra a sobreabundância para baixas metalicidades, já bem estabelecida para o oxigênio. Discutimos as abundâncias do enxofre no contexto da Evolução Química da Galáxia. Apresentamos resultados preliminares muito precisos para a linha proibida do oxigênio l6300 e comparamos estes com os obtidos para o tripleto em l7774. Quantificamos os efeitos não-ETL presentes no tripleto em função dos parâmetros atmosféricos estelares.

  10. Evolução química em galáxias compactas azuis (BCGs)

    NASA Astrophysics Data System (ADS)

    Lanfranchi, G. A.; Matteucci, F.


    Neste trabalho, a formação estelar e evolução quí mica em galáxias Compactas Azuis (Blue Compact Galaxies - BCGs) foram estudadas através da comparação de previsões de modelos de evolução quí mica a várias razões de abundância quí mica observadas nestas galáxias. Modelos detalhados com recentes dados de nucleossí ntese e que levam em consideração o papel desempenahdo por supernovas de ambos os tipos (II e Ia) na evolução galáctica foram desenvolvidos para as BCGs permitindo seguir a evolução de vários elementos quí micos (H, D, He, C, N, O, Mg, Si, S, Ca, e Fe). O modelo é caracterizado pelas prescrições adotadas para a formação estelar, a qual ocorre em vários surtos de atividade separados por longos perí odos quiescentes. Após ajustar os melhores modelos aos dados observacionais, as previsões destes modelos foram comparadas também a razões de abundância observadas em sistemas Damped Lyman alpha (DLAs) e a origem do N (primária ou secundária) foi discutida. Alguns dos resultados obtidos são: i) as razões de abundância observadas nas BCGs são reproduzidas por modelos com 2 a 7 surtos de formação estelar com eficiência entre n = 0.2-0.9 Gano-1; ii) os baixos valores de N/O observados nestas galáxias são um resultado natural de uma formação estelar em surtos; iii) os modelos para BCGs podem reproduzir os dados dos DLAs, iv) uma quantidade "baixa" de N primário produzido em estrelas de alta massa pode ser uma explicação para os baixos valores de [N/a] observados em DLAs.

  11. Network as transconcept: elements for a conceptual demarcation in the field of public health.


    Amaral, Carlos Eduardo Menezes; Bosi, Maria Lúcia Magalhães


    The main proposal to set up an articulated mode of operation of health services has been the concept of network, which has been appropriated in different ways in the field of public health, as it is used in other disciplinary fields or even taking it from common sense. Amid the diversity of uses and concepts, we recognize the need for rigorous conceptual demarcation about networks in the field of health. Such concern aims to preserve the strategic potential of this concept in the research and planning in the field, overcoming uncertainties and distortions still observed in its discourse-analytic circulation in public health. To this end, we will introduce the current uses of network in different disciplinary fields, emphasizing dialogues with the field of public health. With this, we intend to stimulate discussions about the development of empirical dimensions and analytical models that may allow us to understand the processes produced within and around health networks. RESUMO A principal proposta para configurar um modo articulado de funcionamento dos serviços de saúde tem sido o conceito de rede, que vem sendo apropriado de diferentes formas no campo da saúde coletiva, conforme seu emprego em outros campos disciplinares ou mesmo tomando-o do senso comum. Em meio à pluralidade de usos e concepções, reconhecemos a necessidade de rigorosa demarcação conceitual acerca de redes no campo da saúde. Tal preocupação visa a preservar o potencial estratégico desse conceito na investigação e planificação no campo, superando precariedades e distorções ainda observadas em sua circulação discursivo-analítica na saúde coletiva. Para tanto, apresentaremos os usos correntes de rede em diferentes campos disciplinares, destacando interlocuções com o campo da saúde coletiva. Com isso, pretendemos estimular o debate acerca do desenvolvimento de dimensões empíricas e modelos de análise que permitam compreender os processos produzidos no interior e ao redor

  12. Abundâncias em estrelas de Bário

    NASA Astrophysics Data System (ADS)

    Allen, D. M.


    Estrelas de Bário apresentam linhas intensas de elementos produzidos pelo processos (ex: Ba, Y, Sr, Zr) e bandas intensas de CN, C2 e CH. A hipótese mais aceita sobre a origem deste grupo peculiar é a de que essas estrelas façam parte de sistemas binários, tendo recebido material enriquecido em elementos pesados da companheira mais evoluída. Apresentamos neste trabalho uma análise detalhada de uma amostra de estrelas desta classe, incluindo determinação de parâmetros atmosféricos e cálculo de abundâncias. As temperaturas efetivas foram determinadas a partir de dados fotométricos obtidos com o Fotrap instalado no telescópio Zeiss do LNA (Laboratório Nacional de Astrofísica) (B-V, V-I, R-I, V-R), e coletados na literatura nos catálogos Hipparcos (B-V), 2MASS (Two Micron All Sky Survey) (V-K) e The General Catalogue Photometric Data (sistema Geneva). Obtivemos uma faixa de temperaturas de 4400 £ Tef £ 6500. As metalicidades foram determinadas a partir de linhas de Fe I e Fe II, estando os resultados no intervalo -1 £ [Fe/H] £ +0.1. O log g foi determinado pelo equilíbrio de ionização e pela relação com a magnitude bolométrica, a temperatura e a massa, sendo os resultados na faixa 1.5 £ log g £ 4.5. As distâncias utilizadas foram determinadas com o auxílio das paralaxes Hipparcos, e as massas determinadas por modelos de isócronas. Os espectros utilizados foram obtidos com o espectrógrafo FEROS no Telescópio de 1,5m do ESO (European Southern Observatory). As abundâncias foram calculadas por meio de síntese espectral de linhas individuais incluindo elementos alfa, pico do Fe, s e r. Encontramos um excesso de elementos pesados em relação ao Fe, como esperado para estrelas de Bário.

  13. Detecção da fase impulsiva de uma explosão solar gigante até 405 GHz

    NASA Astrophysics Data System (ADS)

    Raulin, J.-P.; Makhmutov, V.; Kaufmann, P.; Pacini, A. A.; Luethi, T.; Hudson, H. S.; Gary, D. E.; Yoshimori, M.


    A explosão ocorrida no dia 25/08/2001 foi uma das mais intensas do presente ciclo solar em ondas de rádio de altas frequências. Foram medidas em ondas milimétricas e submilimétricas, aproximadamente, 105 e vários milhares de unidades de fluxo solar, respectivamente. Apresentamos um estudo deste evento em múltiplas frequências, desde microondas (1GHz), até ondas submilimétricas (405 GHz) detectadas pelo Telescópio Solar para ondas Submilimétricas (SST). Esta base de dados foi complementada utilizando-se o experimento Yohkoh, incluindo a emissão em raios-X duros e raios-g (até 100 MeV), e imagens em raios-X moles da região ativa envolvida. Enfocamos e discutimos principalmente os seguintes aspectos da fase impulsiva do evento: (i) as implicações deduzidas do espectro eletromagnético, obtido pela primeira vez até 405 GHz; (ii) a dinâmica da região ativa. Os resultados mostram que para explicar o espectro rádio observado, são necessários entre 3.5×1037 e 1.5×1039 elétrons acelerados acima de 20 keV em uma região de campo magnético entre 300 e 800 Gauss. A estimativa do fluxo de fótons que seria produzido por estes elétrons, mostra que grande parte deles não precipitou na baixa atmosfera. A evolução temporal da emissão em raios-X moles revela que a configuração magnética da região ativa foi muito dinâmica durante a fase impulsiva da explosão. Em particular, mostramos que a produção dos elétrons altamente energéticos foi iniciada junto com a aparição, na baixa coroa solar, de um novo sistema compacto de estruturas magnéticas. Este fato sugere que os locais de aceleração estão localizados na baixa atmosfera do Sol, como resultado da interação entre o novo sistema compacto e o campo magnético ambiente da região ativa.

  14. Projeto do sistema anti-ressonante da fiação dos transdutores para o detector Mario Schenberg

    NASA Astrophysics Data System (ADS)

    Vieira, S. J.., Jr.; Melo, J. L.


    O detector de ondas gravitacionais Mario Schenberg está sendo projetado e construído pelo grupo Gráviton. Sua construção está ocorrendo no Laboratório de Estado Sólido e Baixas Temperaturas (LESBT) da Universidade de São Paulo, na cidade de São Paulo. Esse detector possui uma massa ressonante esférica de cobre-alumínio, com 65 cm de diâmetro, pesando aproximadamente 1150 Kg, suspensa por um sistema de isolamento vibracional, que se encontra em fase de testes preliminares. A real eficácia desse sistema, entretanto, só poderá ser comprovada quando o detector estiver aparelhado com, pelo menos, um transdutor eletromecânico de altíssima sensibilidade acoplado à massa ressonante. Neste momento, não só este sistema de isolamento vibracional será posto em teste, como o do projeto da fiação que transporta os sinais de microondas até os transdutores e destes para a pré-amplificação. Apesar dessa fiação ter sido projetada para não apresentar nenhum contato com a superfície esférica da antena, de maneira a não haver nenhuma transmissão de ruído vibracional do laboratório para esta, deve-se minimizar o ruído microfônico produzido nessa fiação por oscilações mecânicas, uma vez que ela não utiliza nenhum sistema de isolamento vibracional. Com o intuito de resolver este problema, projetamos uma estrutura, formada por pequenos cilindros conectados por barras, a qual não terá nenhuma ressonância mecânica na faixa de freqüências de interesse para detecção (3000 - 3400 Hz). Desta forma, as vibrações nessa faixa não serão amplificadas. O projeto foi feito usando iterativamente, de maneira a otimizar os resultados obtidos, o programa de elementos finitos Msc/Nastran. Através de simulações feitas neste programa, determinamos os parâmetros geométricos ideais a serem utilizados, os quais proporcionam a maior região espectral de interesse livre de ressonâncias.

  15. Hepcidin: an important iron metabolism regulator in chronic kidney disease.


    Antunes, Sandra Azevedo; Canziani, Maria Eugênia Fernandes


    Anemia is a common complication and its impact on morbimortality in patients with chronic kidney disease (CKD) is well known. The discovery of hepcidin and its functions has contributed to a better understanding of iron metabolism disorders in CKD anemia. Hepcidin is a peptide mainly produced by hepatocytes and, through a connection with ferroportin, it regulates iron absorption in the duodenum and its release of stock cells. High hepcidin concentrations described in patients with CKD, especially in more advanced stages are attributed to decreased renal excretion and increased production. The elevation of hepcidin has been associated with infection, inflammation, atherosclerosis, insulin resistance and oxidative stress. Some strategies were tested to reduce the effects of hepcidin in patients with CKD, however more studies are necessary to assess the impact of its modulation in the management of anemia in this population. Resumo Anemia é uma complicação frequente e seu impacto na morbimortalidade é bem conhecido em pacientes com doença renal crônica (DRC). A descoberta da hepcidina e de suas funções contribuíram para melhor compreensão dos distúrbios do metabolismo de ferro na anemia da DRC. Hepcidina é um peptídeo produzido principalmente pelos hepatócitos, e através de sua ligação com a ferroportina, regula a absorção de ferro no duodeno e sua liberação das células de estoque. Altas concentrações de hepcidina descritas em pacientes com DRC, principalmente em estádios mais avançados, são atribuídas à diminuição da excreção renal e ao aumento de sua produção. Elevação de hepcidina tem sido associada à ocorrência de infecção, inflamação, aterosclerose, resistência à insulina e estresse oxidativo. Algumas estratégias foram testadas para diminuir os efeitos da hepcidina em pacientes com DRC, entretanto, serão necessários mais estudos para avaliar o impacto de sua modulação no manejo da anemia nessa população.

  16. A revision of the shore-fly genus Hydrochasma Hendel (Diptera, Ephydridae)

    PubMed Central

    Mathis, Wayne N.; Zatwarnicki, Tadeusz


    Abstract A revision of the shore-fly genus Hydrochasma Hendel. The species of the genus Hydrochasma Hendel are revised, including 27 new species (type locality in parenthesis): H. andeum (Ecuador. Guayas: Boliche (02°07.7'S, 79°35.5'W)), H. annae (United States. Utah. Grand: Swasey Beach (15.3 km N Green River; 39°07'N, 110°06.6'W; Green River; 1255 m)), H. capsum (Ecuador. Orellana: RíoTiputini (0°38.2'S, 76°8.9'W)), H. castilloi (Ecuador. Loja: Catamayo (03°59'S, 79°21'W)), H. crenulum (Peru. Cuzco: Paucartambo, Atalaya (Río Alto Madre de Dios; 12°53.3'S, 71°21.6'W; 600 m)), H. denticum (Ecuador. Orellana: Río Tiputini (0°38.2'S, 76°8.9'W)), H. digitatum (Peru. Madre de Dios: Diamante (Río Alto Madre de Dios; 12°19.9'S, 70°57.5'W; 400 m)), H. distinctum (Costa Rica. Limón: Parque Nacional Barbilla, Sector Casas Negras, (10°0.8'N, 83°28.1'W; 300 m)), H. dolabrutum (Dominican Republic. Barahona: Barahona (18°12'N, 71°5.3'W)), H. edmistoni (Dominican Republic. Azua: near Pueblo Viejo (18°24.8'N, 70°44.7'W)), H. falcatum (Peru. Madre de Dios: Río Manu, Erika (near Salvación; 12°50.7'S, 71°23.3'W; 550 m)), H. glochium (Dominican Republic. Peravia: San José Ocoa (10 km NE; 18°35'N, 70°25.6'W)), H. kaieteur (Guyana. Kaieteur Falls (05°10.5'N, 59°26.9'W)), H. lineatum (Trinidad and Tobago. Trinidad. St. George: Filette (1 km SE; 10°47'N, 61°21'W)), H. miguelito (Honduras. Cortés: San Pedro Sula (8 km S; 15°25.7'N, 88°01.4'W)), H. octogonum (Ecuador. Manabí: Pichincha (01°02.7'S, 79°49.2'W)), H. parallelum (Trinidad and Tobago. Trinidad. St. Andrew: Lower Manzanilla (16 km S; 10°22'N, 61°01'W)), H. peniculum (Dominican Republic. Pedernales: Pedernales (18°01.8'N, 71°44.7'W)), H. rictum (Honduras. Cortés: San Pedro Sula (8 km S; 15°25.7'N, 88°01.4'W)), H. robustum (Brazil. São Paulo. Ubatuba, Praia Puruba (23°21'S, 44°55.6'W; beach)), H. sagittarium (Trinidad and Tobago. Tobago: St. John: Parlatuvier (creek; 11°17.9'N

  17. Sources de photons uniques et expérience à choix retardé de Wheeler : la dualité onde corpuscule à l'épreuve de l'expérience

    NASA Astrophysics Data System (ADS)

    Jacques, V.

    ésentations classiques de la réalité physique incompatibles. Le travail décrit dans cet ouvrage s'inscrit dans l'étude de la dualité onde-corpuscule pour un photon unique à l'aide d'une source de photons uniques fondée sur l'excitation impulsionnelle d'un centre coloré NV individuel dans un nanocristal de diamant. Nous présentons dans un premier temps une expérience d'interférence à un photon très proche dans sa conception de celle des trous d'Young. Cette expérience nous permettra de discuter de la complémentarité entre interférence et connaissance du chemin suivi par la particule dans l'interféromètre. Pour aller un peu plus au cÅ`ur des problèmes conceptuels soulevés par la dualité onde-corpuscule, nous décrivons par la suite la réalisation expérimentale de l'expérience de pensée dite de “choix retardé” proposée par Wheeler au début des années soixante-dix. Dans cette expérience, la décision de fermer ou non l'interféromètre, et donc d'observer soit les interférences (associé à une propriété ondulatoire) soit le chemin suivi par le photon dans l'interféromètre (associé à une propriété de type corpusculaire), n'est prise qu'une fois que le photon a franchi l'élément séparateur à l'entrée de l'interféromètre. Les résultats de cette expérience nous permettront de conclure qu'aucune réalité physique classique ne saurait être attribuée au photon indépendamment de l'appareil de mesure, comme le stipule le principe de complémentarité.

  18. A revision of the shore-fly genus Hydrochasma Hendel (Diptera, Ephydridae).


    Mathis, Wayne N; Zatwarnicki, Tadeusz


    A revision of the shore-fly genus Hydrochasma Hendel. The species of the genus Hydrochasma Hendel are revised, including 27 new species (type locality in parenthesis): H. andeum (Ecuador. Guayas: Boliche (02°07.7'S, 79°35.5'W)), H. annae (United States. Utah. Grand: Swasey Beach (15.3 km N Green River; 39°07'N, 110°06.6'W; Green River; 1255 m)), H. capsum (Ecuador. Orellana: RíoTiputini (0°38.2'S, 76°8.9'W)), H. castilloi (Ecuador. Loja: Catamayo (03°59'S, 79°21'W)), H. crenulum (Peru. Cuzco: Paucartambo, Atalaya (Río Alto Madre de Dios; 12°53.3'S, 71°21.6'W; 600 m)), H. denticum (Ecuador. Orellana: Río Tiputini (0°38.2'S, 76°8.9'W)), H. digitatum (Peru. Madre de Dios: Diamante (Río Alto Madre de Dios; 12°19.9'S, 70°57.5'W; 400 m)), H. distinctum (Costa Rica. Limón: Parque Nacional Barbilla, Sector Casas Negras, (10°0.8'N, 83°28.1'W; 300 m)), H. dolabrutum (Dominican Republic. Barahona: Barahona (18°12'N, 71°5.3'W)), H. edmistoni (Dominican Republic. Azua: near Pueblo Viejo (18°24.8'N, 70°44.7'W)), H. falcatum (Peru. Madre de Dios: Río Manu, Erika (near Salvación; 12°50.7'S, 71°23.3'W; 550 m)), H. glochium (Dominican Republic. Peravia: San José Ocoa (10 km NE; 18°35'N, 70°25.6'W)), H. kaieteur (Guyana. Kaieteur Falls (05°10.5'N, 59°26.9'W)), H. lineatum (Trinidad and Tobago. Trinidad. St. George: Filette (1 km SE; 10°47'N, 61°21'W)), H. miguelito (Honduras. Cortés: San Pedro Sula (8 km S; 15°25.7'N, 88°01.4'W)), H. octogonum (Ecuador. Manabí: Pichincha (01°02.7'S, 79°49.2'W)), H. parallelum (Trinidad and Tobago. Trinidad. St. Andrew: Lower Manzanilla (16 km S; 10°22'N, 61°01'W)), H. peniculum (Dominican Republic. Pedernales: Pedernales (18°01.8'N, 71°44.7'W)), H. rictum (Honduras. Cortés: San Pedro Sula (8 km S; 15°25.7'N, 88°01.4'W)), H. robustum (Brazil. São Paulo. Ubatuba, Praia Puruba (23°21'S, 44°55.6'W; beach)), H. sagittarium (Trinidad and Tobago. Tobago: St. John: Parlatuvier (creek; 11°17.9'N, 60°35'W

  19. A emissão em 8mm e as bandas de Merrill-Sanford em estrelas carbonadas

    NASA Astrophysics Data System (ADS)

    de Mello, A. B.; Lorenz-Martins, S.


    Estrelas carbonadas possuem bandas moleculares em absorção no visível e, no infravermelho (IR) as principais características espectrais se devem a emissão de grãos. Recentemente foi detectada a presença de bandas de SiC2 (Merrill-Sanford, MS) em emissão sendo atribuída à presença de um disco rico em poeira. Neste trabalho analisamos uma amostra de 14 estrelas carbonadas, observadas no telescópio de 1.52 m do ESO em 4 regiões espectrais diferentes, a fim de detectar as bandas de MS em emissão. Nossa amostra é composta de estrelas que apresentam além da emissão em 11.3 mm, outra em 8 mm. Esta última emissão, não usual nestes objetos, tem sido atribuída ou a moléculas de C2H2, ou a um composto sólido ainda indefinido. A detecção de emissões de MS e aquelas no IR, simultaneamente, revelaria um cenário mais complexo que o habitualmente esperado para os ventos destes objetos. No entanto como primeiro resultado, verificamos que as bandas de Merrill-Sanford encontram-se em absorção, não revelando nenhuma conexão com a emissão a 8 mm. Assim, temos duas hipóteses: (a) a emissão a 8 mm se deve à molécula C2H2 ou (b) essa emissão é resultado da emissão térmica de grãos. Testamos a segunda hipótese modelando a amostra com grãos não-homogêneos de SiC e quartzo, o qual emite em aproximadamente 8mm. Este grão seria produzido em uma fase evolutiva anterior a das carbonadas (estrelas S) e por terem uma estrutura cristalina são destruídos apenas na presença de campos de radiação ultravioleta muito intensos. Os modelos para os envoltórios utilizam o método de Monte Carlo para descrever o problema do transporte da radiação. As conclusões deste trabalho são: (1) as bandas de Merrill-Sanford se encontram em absorção, sugerindo um cenário usual para os ventos das estrelas da amostra; (2) neste cenário, a emissão em 8 mm seria resultado de grãos de quartzo com mantos de SiC, indicando que o quartzo poderia sobreviver a fase

  20. Emissão de hidrogênio molecular e [FeII] em núcleos Seyfert

    NASA Astrophysics Data System (ADS)

    Rodríguez-Ardila, A.; Pastoriza, M. G.; Viegas, S.


    Um dos problemas fundamentais em núcleos ativos de galáxias (AGN) é determinar os mecanismos de excitação dominantes do gás emissor de linhas estreitas, seja este excitado por mecanismos não-estelares (fotoionização por uma fonte central ou choques produzidos por um jato rádio no gás circumnuclear) ou estelares (fotoionização por estrelas OB ou choques originados por um remanescente de supernova em expansão). Essa ambiguedade se faz mais evidente ao intepretar o espectro de espécies tais como H2 e [FeII]. Na primeira, fluorescência UV, processos térmicos (choques e/ou aquecimento por fótons) ou illuminação por raios-x, podem ser responsáveis pelo espectro observado enquanto que na segunda, os dois últimos mechanismos seriam relevantes. Neste trabalho, utilizando espectroscópia JHK de média resolução para uma amostra de AGN encontramos que o H2 observado é gerado principalmente por processos térmicos associados à presença de episódios de formação estelar circumnuclear. No entanto, em galáxias tais como NGC4151 as observações mostram que o hidrogênio molecular origina-se, principalmente, da interação entre o jato radio e o gás da NLR. Esses resultados baseiam-se nos valores das razões de linhas H2 2.24/2.12 mm e H2 2.03/2.22 mm. H2 2.24/2.12 separa claramente processos não-térmicos dos térmicos enquanto H2 2.03/2.22 serve como indicador de temperatura da componente térmica, e portanto, discrimina entre choques e associações OB. Já para o [FeII], as observações são compatíveis com excitação produzida diretamente pela fonte central ou choques associados com o jato rádio. A comparação da largura dos perfis de linhas observados permite concluir que não há correlação entre a emissão de H2 e [FeII]. Em praticamente todos os casos analisados, os perfis das linhas de H2 são não-resolvidos, enquanto que os perfis de [FeII] indicam, em alguns casos, velocidades de até 600 km/s.

  1. Soil carbon stocks in response to management changes due to vinasse application in sugarcane production in southeast of Brazil

    NASA Astrophysics Data System (ADS)

    Fernandes Zani, Caio; Simoes Barneze, Arlete; Clemente Cerri, Carlos


    application at 1 m depth were 117.23 Mg ha-1 and 126.92 Mg ha-1, and at 0.3 m depth we found 50.34 Mg ha-1 and 55.54 Mg ha-1, respectively. It represented an increase 8.3% and 10.3% in soil C stocks in areas with vinasse application at 1 m and 0.3 m soil depth. This information may be used as a basis for public policies decision which dealing of the land use and global warming. The scientific information obtained in this research will be included in carbon footprint calculation of ethanol production and its use as biofuel. References Ellert B.H., Bettany J.R. 1995. Calculation of organic matter and nutrients stored in soils under contrasting management regimes. Can. J. Soil Sci. 75:529-538. Six J., Ogle S.M., Breidt F.J., Conant R.T., Mosier A.R., Paustian K. 2004. The potential to mitigate global warming with no-tillage management is only realized when practiced in the long term. Glob. Chang. Biol. 10:155-160. Soares L.H.B., Alves B.J.R., Urquiaga S., Boddey R.M. 2009. Mitigação das emissões de gases efeito estufa pelo uso de etanol da cana-de-açúcar produzido no Brasil. Embrapa Agrobiologia, Seropédica, RJ. 14p. (Circular Técnica, 27).

  2. Farmyard Manure and Fertilizer Effects on Seed Potato (Solanum tuberosum L.) Yield in Green House Production

    NASA Astrophysics Data System (ADS)

    László, M.


    ção máximas, principalmente em solos mais ácidos e pobres em matéria orgânico. A adubação fosfatada é muito importante no crescimento inicial da planta e, além de aumentar a produção de tuberculos em peso e números, aumenta também a quantidade e qualidade do amido neles contidos e reduz perdas durante o armazenamento dos mesmos. A quantidade de fósforo a aplicar dependerá da análise do solo considerando- se principalmente o nível de P existente e a textura do solo. Solos de textura média e arenosa necessitam maior conteúdo de fósforo do que os de textura argilosa para serem considerandos solos de baixo, médio ou alto teor de fósfato. Efeito da potássica Embora seja o elemento mais absorbido pela batateira, nem sempre há resposta positiva da aduba potássica sobre o rendimento da cultura. Provavelmente isto esteja relacionado com níveis elevados deste elemento no solo (Kurnik et all. 2001.). Entretanto, em solos com médios e baixos teores de potássio, aumentos significativos são conseguidos. Por isto, as recomendações de adubação com potássio, nas diversas regiões do mundo, variam de 50-300 kg ha-1 de K2O. Resultados de trabalhos em brasiléiros têm demonstrado que a aduba potássica pode ser substituída pela aplicação de 150 m3 ha-1 de vinhaça de cana de açúcar. Ao elevar- se a dose de fertilização potássica deverá haver precaução para que a adubação magnesiana seja suficiente. O K além de aumentar a produção, em solos deficientes, aumenta também o tamanho dos tubérculos produzidos, e a proporção de tubérculos grandes. Deficiência no suprimento de potássio á planta pode acarretar produção de tubérculos com elevada susceptibilidade aos danos mecánicos pós-colheita. Os tubérculos injuriados enegrecem facilmente e este enegrecimento é inversamente proporcional á quantidade de potássio nos tuberculos. Ademais, quando fritos dão origem a um produto escuro, de baixa valor comercial. Manejo de aduba