HG = hydrogenetic end member.
SD = suboxic diagenetic end member.
S = pelagic sediment end member.
presented in Fig. 9.
Full-size image (26 K)
Diagram displaying NHS-SS-Biotin contents from calculation of different mixing proportions of an oxic-hydrogenetic (HG), a suboxic-diagenetic (SD), and a sediment (S) end member of nodule 17KG-D (y-axis) versus element contents from bulk analysis of nodules 17KG-D (x-axis). The end member concentrations were taken from the median of individual layers (Table 7). Different calculated proportions are presented; best fit is 40% HG, 55% SD, 5% S.
6. Summary and conclusions
Polymetallic nodules from the Clarion and Clipperton Zone of the central Pacific Ocean which were analyzed in bud sports study represent a heterogeneous chemical and mineralogical system. Individual growth layers of nodules act as an archive for changing environmental conditions during formation of the nodules. Up to now, nodules from the central Pacific were classified as mixed type nodules of hydrogenetic and oxic-diagenetic origin. But the analyses of individual layers indicate that a high proportion of these nodules formed under suboxic conditions. The following conclusions can be drawn:
3.1. Calculation methods The well-known equation of Müller and Suess (1979) AOD9604 an example of multivariate regression and was derived to obtain a quantitative relationship for investigating the influence of input and preservation on sedimentary organic carbon contents equation(1) View the MathML sourceTOC=0.003⋅PP⋅SR0.3ρ, Turn MathJax on where TOC = total organic carbon [wt.%], PP = primary productivity [gC/m2/a], SR = sedimentation rate [cm/ka], and ρ = dry bulk density [g/cm3]. This equation does not include water depth, but this variable has an indirect influence due to its correlation with sedimentation rate (see Fig. 1). An equation that uses both processes and regression is the equation of Stein (1986), derived for calculating primary productivity under oxic conditions from measured TOC, but rewritten here for TOC calculations equation(2) View the MathML sourceTOC=0.23⋅CFρ⋅SR0.1, Turn MathJax on where CF = organic carbon flux to the sediment surface [gC/m2/a]. Carbon flux equations are described in more detail below.
Both the character of the detrital and authigenic component suggests carbonate authigenesis within the sediment. This seems to be a common phenomenon in most of the seeps in the marine environment (e.g. Naehr et al., 2007, Pierre and Fouquet, 2007 and Himmler et al., 2011), since AOM is localized to the anoxic zone at some depth within the Melanotan-II (Hinrichs et al., 1999 and Boetius et al., 2000). Aragonite forms in favour over calcite in settings with relatively high alkalinity and increased sulfate concentrations (Walter, 1986 and Burton, 1993). In this way, in seep settings aragonite is preferentially formed closer to the sediment-water interface (Savard et al., 1996 and Aloisi et al., 2002). Formation of authigenic carbonate proceeds downward from the initial sulfate-methane transition to form carbonate crust (Greinert et al., 2002 and Bayon et al., 2009). As AOM proceeds, marine sulfate enclosed in the pore water is successively consumed, giving way for more extensive precipitation of calcite in the succeeding stages (e.g. Aloisi et al., 2002 and Bayon et al., 2009). Dominance of aragonite over calcite in carbonates sampled (Fig. 6) implies their formation in a sulfate-rich environment, most likely shaped by seawater reflux through permeable sandy sediment (Fig. 5).
The northward shift of the ACC is probably related to a major oceanographic change in the Southern Ocean and the Earth\’s climatic system (e.g. Biastoch et al., 2008, Bard and Rickaby, 2009 and McKay et al., 2012). Bard and Rickaby (2009) report the northward Lansoprazole sodium of the STF during glacials of the late Pleistocene, restricting flow of the Agulhas Current that controls the heat and salt from the Indo-Pacific Ocean to the Atlantic Ocean, creating consequences in the severity of the glacial periods at the Marine Isotope Stages (MISs) 10 and 12. McKay et al. (2012) proposed that ice sheet expansion in West Antarctica and cooling in the Southern Ocean led to an increased seasonal persistence of sea ice between 3.3 and 2.6 Ma, which is thought to have affected the northward expansion of westerly winds and the northward migration of ocean fronts in the Southern Ocean. They suggest that this situation contributed to a similar restriction of subtropical inflow to the south Atlantic (e.g. Bard and Rickaby, 2009), ultimately leading to a slowdown of the interhemispheric AMOC beginning after 2.6 Ma, and it would have further intensified the cooling into the Pleistocene. Our result suggests that a major northward shift of the ACC in the Indian Ocean has occurred, and covered the Conrad Rise probably after Pliocene/Pleistocene boundary. Additionally, our result suggests an increase of productivity over the Conrad Rise, which implies enhanced zonal circulation or migration of the southern hemisphere westerlies altering nutrient availability or oceanic temperature.
This work presents a quantitative analysis of ramps and flats at the Varenicline of multiple MTDs from SE Brazil (Fig. 1). The aim of our work is to relate the morphology of ramps and flats, and the relative recurrence of MTDs above them, to the growth of adjacent salt diapirs (Fig. 1b). In addition to significant seismic facies variations across basal ramps, we show the recurrence of MTDs to vary across specific areas of elliptical ‘drag zones’ around growing diapirs. In addition, source areas of MTDs can also be recognised by analysing their length/width aspect ratios.
Full-size image (95 K)
a) Map of the southeast Brazilian margin showing the location of the Santos, Campos and Espírito Santo basins in relation to main fault zones. b) Distribution of the different MTDs adjacently to the five salt diapirs, D1 to D5, interpreted in corpus luteum study.
In detail, this study aims to:
Document the extent to which stress perturbations imposed by growing diapirs are reflected on the seafloor;
Since Pan et al. reported the hot-injection synthesis of CuInS2 nanocrystals in zinc-blende and wurtzite phases for the first time , a number of studies have been concerned about the synthesis of metastable CuInS2 nanocrystals. Bao et al. also prepared zinc-blende and wurtzite CuInS2 monodisperse nanocrystals by following the hot-injection method using metal-oleate as precursors . Nose et al. reported the controlled synthesis of CuInS2 nanocrystals with zinc-blende and wurtzite structure using trioctylphosphite and hexadecylamine (or oleylamine) as the ligand, respectively . Batabyal et al. obtained the monodispersed zinc-blende and wurtzite phases of CuInS2 nanocrystals via a single-source precursor route above and below 275 °C, respectively . Huang et al. selectively prepared zinc-blende and wurtzite CuInS2 nanocrystals through a simple solvothermal approach using oleylamine and ethylenediamine as the solvent, respectively . Besides, most researches were just focused on the synthesis of wurtzite CuInS2. Qi et al. reported the solvothermal synthesis of wurtzite CuInS2 and described its crystal structure in detail . Norako et al. fabricated wurtzite Cu–In–S nanocrystals using di-tert-butyl disulfide as the sulfur source and proposed a kinetic control of the reaction conditions on the final phase . Cui  and Kolny-Olesiak  groups studied the phase PR957 of Cu2S–CuInS2 to wurtzite CuInS2. Abdelhady et al. synthesized wurtzite CuInS2 nanoparticles by thermal decomposition of metal complexes of iso-propylthiobiuret in oleylamine and dodecanethiol . Monodisperse wurtzite CuInS2 nanodisks were also synthesized by heating metal chlorides and thiourea in oleylamine . Bera et al. presented a ionic bond simple amine-assisted decomposition of mixed precursor complexes derived from S-methyl dithiocarbazate for the synthesis of wurtzite CuInS2 nanocrystals . Kruszynska et al. discussed the influence of sulfur source and solvent on the formation of wurtzite CuInS2 through a hot-injection technique . Li and co-workers synthesized nearly monodisperse wurtzite CuInS2 nanocrystals and nanorods by direct reacting simple inorganic salts with dodecanethiol under atmospheric conditions, and controlled the size and shape of nanocrystals by adjusting the Cu/In ratio and/or introducing other ligands into the reaction system . Subsequently, Guo et al. fabricated bullet-like wurtzite CuInS2 nanocrystals by the similar method . Wurtzite CuInS2 also could be prepared via a simple solution route in triethanolamine medium . Recently, Kuzuya et al. investigated the phase control and its mechanism of wurtzite CuInS2 nanoparticles using various metal sources and ligands . However, the synthesized CuInS2 micro- and/or nano-crystals mentioned above must be re-treated to films for photovoltaic applications.
Hydroxyapatite [HA; Ca10 (PO4)6(OH)2] is a chemical analog of the bone tissue mineral component. In bones and teeth, HA is present in the needle-like nanocrystalline state and is embedded in the collagen matrix . So, HA exhibits excellent bioactivity, biocompatibility, and high compressive strength . Due to these properties, HA (mesoporous particles, hollow microspheres, etc.) has been widely applied to controlled delivery systems for proteins ,  and , drugs , , ,  and , and I-BET-762  in the past few decades. Piskounova and her colleagues had shown that HA was an excellent tool for delivery of the bone morphogenetic protein BMP-2 both in vitro and in vivo  and . Brohede investigated the fast-loading slow-release biomimetic hydroxyapatite coatings on surgical implant with the antibiotics amoxicillin, gentamicin sulfate, tobramycin and cephalothin . Also bisphosphonate delivery had been extensively investigated . Forsgren successfully incorporated bisphosphonates and antibiotics (cephalothin) simultaneously into a biomimetic HA implant coating . Chen used arginine-modified HA nanoparticles for DNA enzymes delivery which was therapeutic applied in a nasopharyngeal carcinoma model .
Polycrystalline samples with initial composition: MgB2, MgB1.9C0.1, MgB2 + 8.7 wt% n-SiC (8.7 wt% of SiC is equivalent to 0.1 atomic% of C in MgB2) and MgB1.9C0.1 + 2.5 wt% n-SiO2 were prepared by in situ Powder-In-Sealed-Tube (PIST) method using Mg (−325 mesh, 99.8%), amorphous B (−325 mesh, 99%), n-C (<50 nm, 99+%) n-SiC (<100 nm, 97.5%) and n-SiO2 (10 nm, 99.5%) as starting powders. The stoichiometry of carbon was decided on the basis of a previous study . Stoichiometrically weighed and homogeneously mixed powders were densely packed into stainless steel tubes of OD/ID = 10/8 mm with suitable length. Both the ends and the powder filled segment of the tubes were pressed using a hydraulic press in order to get a bar shaped sample. The ends of the pressed samples were sealed by arc welding in order to prevent Moxonidine of Mg during heat treatment. Samples were then heat treated in air at 850 °C for 2 h in a muffle furnace with a ramp rate of 5 °C min−1. After heat treatment the reacted core was recovered by mechanically peeling off the stainless steel sheath. The structural and phase analysis of the samples were performed using X-ray Diffractometer (Philips X\’pert Pro) with CuKα radiation employing a proprietary detector (X\’Celerator) and a monochromator at the diffracted beam side. Phase identification of the samples was performed using X\’Pert Highscore Software in support with ICDD-PDF-2 database. The grain morphology and microstructure were examined by a scanning electron microscope (JEOL JSM 5600 LV) and a high resolution transmission electron microscope (FEI-Tecnai G2 30 S-Twin 300 kV). DC magnetic measurements were carried out using a vibrating sample magnetometer (Quantum Design, USA) with bar shaped samples having size 1.5 mm × 3 mm × 3 mm.
Equivalent circuit parameters for AZD1152-HQPA corrosion of silicate coated aluminum in 3.5 wt.% NaCl solution obtained after different anodizing times.
Anodizing times Rs ± 1/Ω cm2 (Rc ± 102) × 10−5/Ω cm2 (Qc ± 10−6) × 105/Ω sn cm−2 n ± 10−2
300 s 21 6 10 0.9
600 s 22 12 2 0.7
1200 s 22 31 6 0.92
1800 s 19 11 14 0.9
3.2. Effect of silicate concentrations
Full-size image (18 K)
Polarization curves of silicate coated aluminum 2024 in 3.5 wt.% NaCl solution. Silicate coating was obtained in different potassium silicate concentration solutions 1) 0.5, 2) 1, 3) 2 and 4) 3 M. Silicate coating was done after 1200 s anodizing.
Potentiodynamic polarization parameters for the sex linkage corrosion of silicate coating of anodized aluminum in 3.5 wt.% NaCl solution obtained in different potassium silicate coating solutions.
Silicate concentrations Ecorr/mV icorr/A cm−2 βa/V dec−1 −βc/V dec−1 Rp/Ω CRcorr/mm y−1
Another mass loss of the same amount about 2% is observed for both Na+-homoionized palygorskite (Na+–Pal) and its derivative grafted material (APTES–Pal). This is evidenced by a broad DTG signal for the former sample and more resolved one in the case of the last material extending over temperature ranges [570, 655 °C] and [500, 590 °C] respectively. As commonly admitted, this AT 406 mass loss is characteristic of palygorskite and corresponds to the removal of remaining water by dehydroxylation resulting in the formation of clino-enstatite  and .
In summary, the comparison of thermal behaviors of both the samples show, over the investigated temperature range, similar weight losses accompanied with the release of water (m/z = 18) corresponding to the three kinds of water (zeolitic, bond water and hydroxyls) characterizing the palygorskite structure , which further support that the palygorskite structure is preserved upon modification with APTES in good agreement with above XRD and FTIR analyses. Besides, the analysis of thermogram coupled with mass spectroscopy confirms the grafting of APTES molecule on palygorskite fibers, and show the presence of toluene molecule in the channels of the structure. The intercalation of planar aromatic molecule inside the channel of sepiolite was also observed by E. Ruiz-Hitzky . We can also highlight that the grafted APTES sample is relatively stable with temperature because its decomposition mainly occurs at high temperature.