scholarly journals Lateritization process of peridotites in Siruka, Choiseul, Solomon Islands

2015 ◽  
Vol 3 (2) ◽  
Author(s):  
Christopher V. Sagapoa ◽  
Akira Imai ◽  
Takeyuki Ogata ◽  
Kotaro Yonezu ◽  
Koichiro Watanabe
Keyword(s):  
Solomon Islands ◽  
The Other ◽  
Nickel Laterite ◽  
Serpentinized Peridotite ◽  
Other Hand ◽  
Low Concentrations ◽  
Residual Elements ◽  
Weathering Crusts ◽  
Iron Chromium ◽  
Cobalt And Nickel

The lateritic weathering crusts exposed in Siruka, Choiseul Islands, Solomon Islands, were developed on the expense of serpentinized peridotite underlain by Siruka schists and Voza lavas with a subhorizontal contact. The lateritic profiles consist of three generalized zones: bedrock, saprolitic zone (weathered and decomposed zone) and the limonitic zones. The profiles demonstrate variations in depths and continuity but illustrate mineralogy and geochemical affinity down profile and are analogous to saprolitic nickel laterite deposits. Silica and magnesia in the bed rock and the saprolitic zones have been removed and only the residual elements (iron, chromium, aluminium, manganese, cobalt and nickel) remain in the limonitic zone. These elements are relatively concentrated as a result of the removal of the soluble elements. Nickel is associated with silica and magnesia, as lizardite ormixed gels (garnierite nickel ore) at the weathering fronts. On the other hand, nickel, with generally low concentrations (

Distribution of metallic trace elements (ETM) in surface soils around the Mediouna discharge (southern of Casablanca)

2019 ◽  
Author(s):  
Chem Int
Keyword(s):  
Trace Elements ◽  
Organic Matter ◽  
Spatial Distribution ◽  
Soil Samples ◽  
The Other ◽  
Surface Soils ◽  
Other Hand ◽  
Metallic Trace Elements ◽  
Low Concentrations ◽  
Uncontrolled Landfill

The objective of present research was to characterize the surface soils located at 300, 600 and 1000 m of an uncontrolled landfill. The work also aims to evaluate the levels and spatial distribution of metallic trace elements (Cd, Pb, Cu, Ni, Zn, Cr, Co and As) in these soils. Soil samples were collected in 36 points around the landfill. Results showed that Cd, Pb, Zn are concentrated in the soils rich in clay and carbonates, and in organic matter, located at 300 m from the landfill. The basic pH of all soils enhances the retention of these metals. On the other hand, As present in soils at 300, 600 and 1000 m at concentrations slightly higher than those of referenced soils were apparently mobilized by water from the solid/water interfaces. The other metals Cu, Ni, Co, Cr are present at very low concentrations.

EFFECT OF ANTIBACTERIAL AGENTS ON THE AUTOPLAQUE PHENOMENON OF PSEUDOMONAS AERUGINOSA

1965 ◽  
Vol 11 (2) ◽  
pp. 213-219 ◽  
Author(s):  
Richard S. Berk
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Antibacterial Agents ◽  
Agar Medium ◽  
The Other ◽  
Other Hand ◽  
Low Concentrations ◽  
Glucose Agar

A survey of 75 cultures of Pseudomonas aeruginosa containing only one discernible phenotype indicated that 68 routinely exhibited spontaneous lysis, resulting in the appearance of turbid erosions or autoplaques (AP+) when grown on a tryptone–glucose agar medium. Single supplements of non-inhibitory levels of chloromycetin, aureomycin, tetracycline, declomycin, and streptomycin increased the degree of lysis of AP+ strains, but were without effect on AP− strains. Enhancement of lysis was also obtained with sulfadiazine, sulfathiazole, sulfamethoxypyridazine, elkosin, gantrisin, and triple sulfa, while little or no effect was observed with sulfamerizine and thiosulfil. On the other hand, low concentrations of either acriflavine or proflavine retarded the rate and degree of lysis, while single supplements of the active antibiotics overcame the suppressive effects of the dyes.

Analysis of Burmese and Thai Rubies by PIXE

1988 ◽  
Vol 42 (1) ◽  
pp. 44-48 ◽  
Author(s):  
S. M. Tang ◽  
S. H. Tang ◽  
T. S. Tay ◽  
A. T. Retty
Keyword(s):  
Trace Element ◽  
Trace Element Analysis ◽  
The Other ◽  
Element Analysis ◽  
X Ray ◽  
Other Hand ◽  
Low Concentrations

Trace element analysis of 60 Burmese and Thai rubies by using the technique of proton-induced x-ray emission was carried out. It was found that the Burmese rubies contained higher concentrations of all impurities except iron. Our results also reveal that vanadium and iron are useful indicators for Burmese and Thai ruby attribution. The Thai rubies have high contents of iron and very low concentrations of vanadium. On the other hand, all the Burmese rubies examined contain significant amounts of vanadium, and their iron contents are, on the average, four times lower than those in the Thai rubies.

Potentiation of the Anti-factor VIII Effect of Thrombin in Plasma by the Plasminolytic Derivatives of Fibrinogen and Fibrin

1973 ◽  
Vol 30 (02) ◽  
pp. 235-247
Author(s):  
S Chandra ◽  
D. C Triantaphyllopoulos
Keyword(s):  
Protective Effect ◽  
Factor Viii ◽  
The Other ◽  
Other Hand ◽  
Low Concentrations ◽  
Derivatives Of ◽  
Native Plasma ◽  
As If ◽  
Oxalated Plasma

SummaryThe activity of factor VIII in mixtures of native plasma or blood with fibrinogen derivatives at concentrations high enough to inhibit prothrombin consumption, is greatly reduced. On the other hand the activity of factor VIII was found normal in similar mixtures of adsorbed native plasma with fibrinogen derivatives, where no generation of thrombin could have taken place. The fibrinogen derivatives increased significantly the inactivating effect of low concentrations of thrombin on the activity of factor VIII of mixtures of adsorbed oxalated plasma with the derivatives. The same inactivating effect was exerted by fibrinogen derivatives heated at 60° C for 15 minutes and by plasmin lysed fibrin. In contradistinction addition of intact fibrinogen or fibrinogen derivatives to heat-defibrinated plasma protected factor VIII from inactivation by thrombin. When both, intact fibrinogen and its derivatives, were added simultaneously at the same concentrations at which they were added singly, the protective effect was intermediate between that exerted by intact fibrinogen and fibrinogen derivatives alone. Under these conditions the fibrinogen derivatives appeared as if they potentiated the inactivating effect of thrombin. Probably by inhibiting the formation of structural fibrin they increased the amount of thrombin, which remained unadsorbed and free to inactivate factor VIII.

Electronic Properties of Bi and In Substituted Layered Ba4Pb3O10 Compounds

1998 ◽  
Vol 547 ◽  
Author(s):  
R. Kasal ◽  
J. B. Ulanday ◽  
J. Obien ◽  
B. Jayaram
Keyword(s):  
Electronic Properties ◽  
Carrier Concentration ◽  
Weak Localization ◽  
The Other ◽  
Layered Compounds ◽  
Oxygen Stoichiometry ◽  
Carrier Localization ◽  
X Ray ◽  
Other Hand ◽  
Low Concentrations

AbstractElectronic properties of the layered compounds with the general composition Ban+1(Pb,Bi)nO3n+1 are quite interesting as the crystal structure of these materials is quite similar to that of high-Tc cuprates. We have investigated the effect of Bi and In substitution on the structure, oxygen stoichiometry (carrier concentration) and the electronic properties of Ba4Pb3O10 compounds. The X-ray powder diffraction results indicate that the unit cell symmetry changes from body-centered tetragonal to cubic with the increasing concentration (x) of Bi and In. The oxygen stoichiometry of the materials is found to increase monotonically with the increase in x(Bi). On the other hand it decreased almost linearly with the increasing x(In). Resistivity of the materials is measured as a function of temperature in the temperature region 3-300K. It is found that the room temeprature resistivity increases with increasing x(Bi/In). Since the oxygen stoichiometry values suggest an increase in the carrier concentration with increasing x(Bi/In), it appears that the disorder caused by the substitution at the Pb site has lead to the carrier localization. For x(Bi)<0.2, we found that the resistivity varies as a function of lnT, which is indicative of weak localization. However, at higher concentrations 3D-VRH behavior is observed. On the other hand the resistivity of indium substituted samples show M-I transition, at low concentrations.

Effect of Activation Pretreatment on the Pyrolysis Behavior of Sludge

2020 ◽  
Vol 14 (4) ◽  
pp. 461-466
Author(s):  
Siyi Luo ◽  
Lin Liu ◽  
Yanggang Song ◽  
Ling Fang ◽  
Junzhi Wang ◽  
...  
Keyword(s):  
Activation Energy ◽  
Chemical Activation ◽  
The Other ◽  
Pyrolysis Process ◽  
Crystallization Water ◽  
Alkaline Activation ◽  
Pyrolysis Behavior ◽  
Combustible Gas ◽  
Other Hand ◽  
Low Concentrations

In the present research, TG and FTIR were used to study the effect of chemical activation pretreatment on sludge pyrolysis. The results showed that both acidic and alkaline activation promoted sludge pyrolysis. KOH inhibited the elimination of crystallization water and promoted the release of volatiles. On the other hand, H2SO4 favored the separation of crystallization water and the release of volatiles. Low concentrations of the activator promoted the production of combustible gas and inhibited the generation of CO2. By analyzing the activation energy of the pyrolysis process using the Coats-Redfern method, it was found that both, KOH and H2SO4, were able to reduce the pyrolysis activation energy. When H2SO4 was used, the effect was more significant.

ECHOES OF BERGSONIAN VITALISM IN SAMUEL BECKETT'S EARLY WORKS

2008 ◽  
Vol 19 (1) ◽  
pp. 143-154 ◽  
Author(s):  
Manfred Milz
Keyword(s):  
The Other ◽  
Henri Bergson ◽  
Other Hand ◽  
Residual Elements ◽  
The One ◽  
Comparative Inquiry

From 1889 to 1934, Henri Bergson differentiated between two aspects of a dynamic naturalism: on the one hand, a rationalized "homogeneous duration" that quantifies a dissected reality by means of symbolisation, and on the other hand, intuited "heterogeneous moments" that dissolve symbols in representing continuously interpenetrating elements qualitatively. These concurring vitalistic conceptions, one of an intellectual, the other of an intuitive nature, can equally be detected in Beckett's attempts to integrate being into art. This comparative inquiry examines resonances of Bergson's vitalism as residual elements of his fading influence in Beckett's early works.

scholarly journals The arc spectrum of palladium, its Zeeman effect and spectral type

1925 ◽  
Vol 109 (750) ◽  
pp. 369-384 ◽  
Keyword(s):  
Atomic Number ◽  
Spectral Type ◽  
Periodic Table ◽  
Zeeman Effect ◽  
Atomic Weight ◽  
The Other ◽  
Present Writer ◽  
Vertical Column ◽  
Other Hand ◽  
Cobalt And Nickel

Palladium is a metal occurring in the eighth group of the periodic table of the elements. Of atomic number 46 and atomic weight 106·7, it is a member of the so-called triad—ruthenium, rhodium, palladium. In the vertical column of the table, palladium occupies a position between nickel and platinum. According to the alternation law governing the multiplicities of terms in the line-spectra of the elements, only odd multiplicities are to be expected in the even groups of the table, and vice versa . The numerous spectral regularities which have been discovered in the arc spectrum of iron, belong entirely to triplet, quintet, and septet systems. The arc spectrum of cobalt, on the other hand, has been shown by Walters to contain quartets. This would seem to indicate that the present grouping of these elements is erroneous, and that a division should occur between iron and cobalt, and probably also between cobalt and nickel. The behaviour of elements in the other groups of the table makes it probable that ruthenium and osmium, in the same vertical column, should be in the same group with iron, and that their spectra should be similar and should contain only odd multiplicities. Similarly, rhodium and iridium would be grouped with cobalt, and only terms of even multiplicity should appear in their spectra. The next group would then be nickel, palladium, and platinum, and again odd multiplicities would be expected. An analysis of the spectrum of nickel has been undertaken at the laboratory of the Bureau of Standards in Washington. Some photographs of the Zeeman effect of nickel have been made by the present writer, and the patterns observed indicate that the spectrum of nickel contains triplet terms.

A study of cometary eruptions through OH radio-lines

1999 ◽  
Vol 173 ◽  
pp. 249-254
Author(s):  
A.M. Silva ◽  
R.D. Miró
Keyword(s):  
Short Duration ◽  
Growth Curves ◽  
The Other ◽  
Initial Mass ◽  
Radio Lines ◽  
Other Hand ◽  
Sudden Rise

AbstractWe have developed a model for theH2OandOHevolution in a comet outburst, assuming that together with the gas, a distribution of icy grains is ejected. With an initial mass of icy grains of 108kg released, theH2OandOHproductions are increased up to a factor two, and the growth curves change drastically in the first two days. The model is applied to eruptions detected in theOHradio monitorings and fits well with the slow variations in the flux. On the other hand, several events of short duration appear, consisting of a sudden rise ofOHflux, followed by a sudden decay on the second day. These apparent short bursts are frequently found as precursors of a more durable eruption. We suggest that both of them are part of a unique eruption, and that the sudden decay is due to collisions that de-excite theOHmaser, when it reaches the Cometopause region located at 1.35 × 105kmfrom the nucleus.

Closing the GAP—A 5Å Scanning Microscope

1969 ◽  
Vol 27 ◽  
pp. 6-7
Author(s):  
A. V. Crewe
Keyword(s):  
Normal Form ◽  
The Other ◽  
Resolving Power ◽  
Scanning Microscope ◽  
Conventional Microscope ◽  
Other Hand ◽  
Closing The Gap ◽  
Thermal Sources ◽  
Better Than ◽  
Transmission Microscope

We have become accustomed to differentiating between the scanning microscope and the conventional transmission microscope according to the resolving power which the two instruments offer. The conventional microscope is capable of a point resolution of a few angstroms and line resolutions of periodic objects of about 1Å. On the other hand, the scanning microscope, in its normal form, is not ordinarily capable of a point resolution better than 100Å. Upon examining reasons for the 100Å limitation, it becomes clear that this is based more on tradition than reason, and in particular, it is a condition imposed upon the microscope by adherence to thermal sources of electrons.

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