An attempt to characterize natural graphites by their trace element content is reported. Ten samples of graphite of known deposits over the world are classified by their graphitization indices, ranging from 0.26 to 1.00, and analyzed for trace elements content. Results of neutron activation analysis of 28 evaluated elements, i.e. Na, Rb, Cs, Th, U, Cr, Fe, Co, As, Sb, Ag, Au, Se, Te, Zn, Hg, Zr...

Introduction: The coupled Sm-Nd systematics of lunar samples has been extensively studied for estimating the timescale of lunar differentiation [1-3]. The published datasets yield consistent ages for Nd isotopic closure within the lunar mantle of ~200 Myr after CAI formation. Although this time constraint is consistent with estimates derived from Hf-W chronometry of the Moon (>60 Myr after CAI ...

A swarm of minette and melanephelinite dikes is exposed over 2500 km 2 in and near the Wasatch Plateau, central Utah, along the western margin of the Colorado Plateaus in the transition zone with the Basin and Range province. To date, 110 vertical dikes in 25 dike sets have been recognized. Strikes shift from about N80øW for 24 Ma dikes, to about N60øW for 18 Ma, to due north for 8-7 m.y. These...

The Ramsey number R(m,n) is the smallest integer p such that any blue-red colouring of the edges of the complete graph Kp forces the appearance of a blue Km or a red Kn. Bipartite Ramsey problems deal with the same questions but the graph explored is the complete bipartite graph instead of the complete graph. We investigate the appearance of simpler monochromatic graphs such as stripes, stars a...

هدف: کارآفرینی یکی از عوامل کلیدی در توسعه اقتصادی و شاخص اساسی جوامع روبه‌رشد است. آنچه که کارآفرین را به آغاز فعالیت ترغیب می‌کند، انگیزه فرایند تبدیل یک فرد عادی است می‌تواند فرصت‌هایی ایجاد کند حداکثر رساندن ثروت کمک کند. هدف این پژوهش شناسایی طبقه‌بندی انگیزه‌های کارآفرینان می­باشد.طراحی/ روش‌شناسی/ رویکرد: با رویکرد مرور نظام­مند استفاده ماتریس شش سلولی دو مؤلفه جهت (کشش یا فشار) منبع (اق...

The Minas-Bahia orogeny juxtaposed Archean crustal fragments and Paleoproterozoic magmatic arcs to form the São Francisco-Congo Paleocontinent by Rhyacian (ca. 2.05 Ga). Unravelling Minas segment of Orogenic Belt (MBO) is an important key understanding role in construction Columbia Supercontinent. Orosirian 1.9 Ga) final amalgamation was preceded a complex history accretion nuclei Proterozoic a...

We report a new radiometric Rb–Sr age determination of 4.0370.04 Ga for high-Al basaltic clast 14321,1353, which is a Group B Apollo 14 high-Al basalt based on its whole-rock incompatible-traceelement chemistry. In addition, available literature Rb–Sr isotope data for Apollo 14 high-Al basalts were reprocessed using the same decay constant and data reduction protocol as used for sample 14321,13...

Abstract The results of this investigation show that Azerbaijan industries and agricultural sector provide considerable anthropogenic impact on the environment Caucasus. use moss biomonitoring technique neutron activation analysis (NAA) is a first attempt to study heavy metal atmospheric deposition in Azerbaijan, country different relief climate. was undertaken summer 2015 man-made pollutants a...

Factors controlling closure in the biotite Rb-Sr system were investigated in a detailed study of an amphibolite-facies metacarbonate from the central Swiss Alps. Oxygen isotope data suggest that the rock cooled as a closed system. Calcite-dolomite thermometry temperatures of ;450°C to 500°C and feldspar thermometry temperatures of ;300°C to 400°C provide evidence of extensive Ca-Mg and Na-K exc...