Improving the technology of gold ore X-ray radiometric separation

Introduction. Gold ore pre-concentration is an urgent issue that can efficiently be solved by the technology of X-ray radiometric separation (XRS). Quarts and quarts-sulfide gold ore XRS is based on the methods of indirect sorting by gold accompanying chemical elements or genetic associate minerals laying the foundation for the creation of separation characteristics for these ores. Additional separation characteristics are required for efficient gold-quartz and gold-quartz-sulfide ore sorting; Irgiredmet Research Institute works on these characteristics search and development. Research methodology. Optimal ore separation characteristics for each specific deposit are chosen after studying and analyzing the spectral information acquired at XRF separators when detecting secondary characteristic radiation from each specific deposit ore samples. The recent modernization of XRF separators significantly enhanced the technological capabilities of XRS concerning intensive search and study of new separation characteristics for gold ore. It has been established that most ores can be efficiently sorted by three characteristics. Research results. A new method of gold ore XRS has been developed which consists of simultaneously applying three, two, or one decision criterion of a lump separation depending on the type, geologicalmineralogical properties, and material composition of the processed ore

Chern–Simons forms for ℝ-linear connections on Lie algebroids

This paper considers the Chern–Simons forms for [Formula: see text]-linear connections on Lie algebroids. A generalized Chern–Simons formula for such [Formula: see text]-linear connections is obtained. We apply it to define the Chern character and secondary characteristic classes for [Formula: see text]-linear connections of Lie algebroids.

The Secondary Characteristic Classes

Changing the representation bundle from T to T ⊗ T∗ gives a sequence where both torsion and curvature live. Vanishing of the curvature gives rise to some closed forms.

Invasive Reed Canarygrass (Phalaris arundinacea) and Native Vegetation Channel Roughness

In instances where vegetation plays a dominant role in the riparian landscape, the type and characteristics of species, particularly a dominant invasive, can alter water velocity at high flows when vegetation is inundated. However, quantifying this resistance in terms of riparian vegetation has largely been ignored or listed as a secondary characteristic on roughness reference tables. We calculated vegetation roughness based on measurements of plant stem stiffness, plant frontal area, stem density, and stem area of three dominant herbaceous plants along the Sprague River, Oregon: the invasive reed canarygrass, native creeping spikerush, and native inflated sedge. Results show slightly lower roughness values than those predicted for vegetation using reference tables. In addition, native creeping spikerush and invasive reed canarygrass exhibit higher roughness values than native inflated sedge, which exhibits values lower than the other two species. These findings are of particular importance where the invasive reed canarygrass is outcompeting native inflated sedge, because with invasive colonization, roughness is increasing in channel zones and therefore is likely changing channel processes. Direct depositional measurements show similar results.

THE CRISIS AND FAIR VALUES: ECHOES OF EARLY TWENTIETH CENTURY DEBATES?

The recent global financial crisis has led to extensive criticism of the role of accounting and its use of fair value measurement in causing and spreading the crisis. This paper argues that the debate surrounding fair value vs. historic cost, and relevance versus reliability, is nothing new; it was at the center of early accounting discussions in the AAA (especially by A.C. Littleton and W.A. Paton), the AICPA (especially G.O. May), and the SEC. Although prominent accounting scholars and practitioners in postdepression 1929 focused on the use of historic cost, the paper discusses the decision of the IASB/FASB to move reliability to a secondary characteristic in its recent conceptual framework. This action ignores lessons learned from a century of research, teaching, and practice of accounting.

ON THE GENERALIZED VOLUME CONJECTURE AND REGULATOR

In this paper, by using the regulator map of Beilinson-Deligne on a curve, we show that the quantization condition posed by Gukov is true for the SL2(ℂ) character variety of the hyperbolic knot in S3. Furthermore, we prove that the corresponding ℂ*-valued closed 1-form is a secondary characteristic class (Chern-Simons) arising from the vanishing first Chern class of the flat line bundle over the smooth part of the character variety, where the flat line bundle is the pullback of the universal Heisenberg line bundle over ℂ* × ℂ*. Based on this result, we give a reformulation of Gukov's generalized volume conjecture from a motivic perspective.