Chemical fractionations in meteorites, 4. Abundances of fourteen trace elements in L-chondrites - Implications for cosmothermometry

Trace element abundances in L-chondrites determined by neutron activation analysis, and implications cosmothermometr

Meteoritic material on the moon

Three types of meteoritic material are found on the moon: micrometeorites, ancient planetesimal debris from the "early intense bombardment," and debris of recent, craterforming projectiles. Their amounts and compositions have been determined from trace element studies. The micrometeorite component is uniformly distributed over the entire lunar surface, but is seen most clearly in mare soils. It has a primitive, C1-chondrite-like composition, and comprises 1 to 1.5 percent of mature soils. Apparently it represents cometary debris. The ancient component is seen in highland breccias and soils. Six varieties have been recognized, differing in their proportions of refractories (Ir, Re), volatiles (Ge, Sb), and Au. All have a fractionated composition, with volatiles depleted relative to siderophiles. The abundance patterns do not match those of the known meteorite classes. These ancient meteoritic components seem to represent the debris of an extinct population of bodies (planetisimals, moonlets) that produced the mare basins during the first 700 Myr of the moon's history. On the basis of their stratigraphy and geographic distribution, five of the six groups are tentatively assigned to specific mare basins: Imbrium, Serenitatis, Crisium, Nectaris, and Humorum or Nubium

Meteoritic material on the moon

Micrometeorites, ancient planetesimal debris from the early intense bombardment, and debris of recent, crater-forming projectiles are discussed and their amounts and compositions have been determined from trace element studies. The micrometeorite component is uniformly distrubuted over the entire lunar surface, but is seen most clearly in mare soils whereas, the ancient component is seen in highland breccias and soils. A few properties of the basin-forming objects are inferred from the trace element data. An attempt is made to reconstruct the bombardment history of the moon from the observation that only basin-forming objects fell on the moon after crustal differentiation. The apparent half-life of basin-forming bodies is close to the calculated value for earth-crossing planetesimals. It is shown that a gap in radiometric ages is expected between the Imbrium and Nectaris impacts, because all 7 basins formed in this interval lie on the farside or east limb

Neutron activation analysis for trace elements. Elements depleted on lunar surface - Implications for origin of moon and meteorite influx rate Final report, 1 Aug. 1969 - 31 Jan. 1971

Neutron activation analysis for trace elements depleted on lunar surface with implications for origin of moon and meteorite influx rat

Application of Core Vector Machine for Prediction of Day-Ahead Electricity Prices

This paper presents Core Vector Machine (CVM) applied for short term electricity price forecasting in an Indian energy market. The accuracy in electricity price forecasting is very crucial for the power producers and consumers. With the accurate price forecasting, power producers can maximize their profit and manage short term operation. Meanwhile, consumers can maximize their utilities efficiently. The objective of this research is to develop models for day-ahead price forecasting using CVM during various seasons. A feature selection technique is used along with the CVM to reduce the variables for accurate price forecasting. Simulation results reveal that the CVM along with feature selection gives better results when compared with other machine learning techniques

The orientation number of three complete graphs with linkages

For a graph G, let D(G) be the set of all strong orientations of G. The orientation number of G is d~(G) = min{d(D)|D ∈ D(G)}, where d(D) denotes the diameter of the digraph D. In this paper, we consider the problem of determining the orientation number of three complete graphs with linkages.Publisher's Versio

NANOEMULSIONS FOR PROSTRATE CANCER THERAPY: AN OVERVIEW

The objective of this review is to focus the inferences of low/poor bioavailability and lack of dose proportionality for the oral delivery of drugs in prostatecancer therapy. To overcome such problems, various formulation strategies has been reported including various methods for the use of surfactants,cyclodextrins, solid dispersions, micronization, permeation enhancers, and lipids. Flutamide is an antiandrogen drug and used for the therapy of prostate cancer. The flutamide drug is having limited clinical application due to its poor water solubility and needs enhancement of its dissolution rate in simulated gastric fluids. The lipid-based formulations such as nanoemulsion have been shown to improve the solubility and oral absorption of lipophilic drugs. To conclude, this article emphasizes the various approaches of nanoemulsion based formulation for prostate cancer therapy.Â

Macroscopic synthesis and characterization of giant fullerenes

Thermal treatment of carbon soot produced by arc evaporation of nickel-filled graphite rods in 500 Torr of helium gives giant fullerenes showing characteristic IR, Raman, NMR and powder XRD signatures. Transmission electron micrographs show faceted structures with pentagonal, hexagonal and spherical shapes. The simplicity and similarity of the IR spectrum with those of smaller fullerenes suggest that the material is a form of large fullerenes. Chemical treatment of the material gives carbon onions

Evaluating the use of lemon grass roots for the reinforcement of a landslideaffected soil from Nilgris district, Tamil Nadu, India

For many centuries, man has been concerned with stabilizing soils in order to either prevent them from being easily eroded or to make them better suited for construction such as for earth building and road construction purposes. Attempts have been made to utilize many natural, synthetic or waste materials for such soil stabilization. Plants have been used as soil cover to prevent erosion and protect slopes. However, there is need to evaluate the engineering characteristics of soils reinforced with plant roots. Consequently, this research work was aimed at investigating the effects of the reinforcement of a landslide-affected soil using the roots of a locally-available plant on the strength and permeability properties of the soil. The natural moisture content, specific gravity, particle size distribution, Atterberg limits, compaction characteristics, shear strength, unconfined compressive strength (UCS) and permeability of the natural (landslide-affected) soil were determined. Results obtained for the natural landslide-affected soil were compared with those of the soil sample admixed with varying proportions (1%, 2%, 3% and 4%) of lemon grass roots. The result shows that the shear strength and UCS of the soil having 4% lemon grass roots is almost double that of the natural soil. Also, the permeability of the soil-root matrix was sufficiently reduced. Planting lemon grass on soils located along slopes is recommended to improve its strength and minimize the ease with which water infiltrates the soil, thereby reducing the incidence of landslide and other water-induced types of slope failure

Structure-Activity (Flotation) Relationship Modeling of Flotation of Sphalerite by N-Arylhydroxamic Acids

Molecular structure is known to play a vital role in the efficiency of chleating collectors in mineral flotation. Hence, flotation efficiencies of congeneric organic compounds used as mineral collectors are amenable to QSAR modeling. Sphalerite grade of the floats of a set of flotation tests conducted with a copper-zinc ore using a series of twenty seven Narylhydroxamic acids of the generic structure Ar-N(OH)C(=0)-R (R= arylialkyliaaralkyl) were modeled using calculated molecular descriptors such as, topochemical, topostructural, quantum chemical, and geometrical parameters. In addition to these molecular descriptors, calculated physicochemical properties such as octanol-water partition coefficient (ClogP), and orga-nic carbon-water partition coefficient (logKoe) were also used to build the regression models. The collectors were classified into C-aryl, C-alkyl, and C-aralkyl. Octanol-water partition coefficient (ClogP) was found to give the best quadratic fit for C-aryl, and the combined set of C-aralkyl and C-alkyl. It was interesting to note that the data for individual sets namely, C-alkyl, and C-aralkyl gave linear fits with positive and negative slopes, resp-ectively. This indicated that the points were distributed on the right hand and left hand sides of the parabola that fits the combined data set