scholarly journals Material Composition of the Mesozoic Alkaline Rocks of the Yukhta Massif (Southern Yakutia, Central-Aldan Ore Region)

2021 ◽  
Vol 906 (1) ◽  
pp. 012114
Author(s):  
Aleksey Ivanov
Keyword(s):  
Igneous Rocks ◽  
Optical Methods ◽  
Petrographic Composition ◽  
Gold Ore ◽  
Weathering Processes ◽  
Karst Formation ◽  
Multi Stage ◽  
Mineralogical Characteristics ◽  
Southern Yakutia

Abstract The paper considers the petrographic composition of the Mesozoic alkaline igneous rocks of the Yukhta massif. It is part of the Central Aldan ore region and is spatially located in the central part of the Nymnyr block. The massif is a large multiphase structure, of the most productive stage of the territory’s development – the Mesozoic tectonic-magmatic activation of the Aldan-Stanovoy shield. Determination of the qualitative quantitative-mineralogical characteristics of the 2 and 3 phases of intrusion (emplacement) most promising for gold-radioactive mineralization with the help of crystal-optical methods was the main goal of this work. As a result of petrographic studies of Mesozoic alkaline igneous rocks, it is defined that, the Yukhta massif is a multiphase magmatic structure, with decrease of the content of dark-colored minerals in rocks from the early to later phases of intrusion. In general, the rocks of the massif bear significant traces of secondary changes, which are related to the gradual formation of the massif. According to the features of the composition of the massif rocks, it was found that the latter could be formed from residual differentiates during the fractional crystallization of rock-forming minerals with the involvement of plagioclases. The Yukhta massif is associated with the large Samolazovskoye gold deposit, which formation is related to an intense contact-metasomatic impact on carbonate rocks. Hydrothermal-metasomatic transformations of the latter are the products of multi-stage silica-alkaline metasomatosis associated with the second and especially with the third phases of the massif intrusion, and with further weathering processes, involving karst formation, disintegration of gold-ore metasomatites and the formation of a thick oxidation zone. From whence it is concluded that uranium being a chemically active element does not accumulate in a hypergenic form within the Yukhta massif. Where the weathering crust is intensively developed, a gold-ore type of mineralization is observed. On the other hand, the rocks of the massif itself, in particular syenites of the 2 and 3 phases of intrusion, may be promising for the uranium-thorium-rare earth (U-Tn-REE) type of mineralization. In general, these studies in this direction will provide insight into a number of issues related to the study of the evolution and metallogeny of the Mesozoic tectonic-magmatic activation of the Aldan-Stanovoy Shield

scholarly journals Development and Validation of Optical Methods for Zeta Potential Determination of Silica and Polystyrene Particles in Aqueous Suspensions

Materials ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 290
Author(s):  
Yannic Ramaye ◽  
Marta Dabrio ◽  
Gert Roebben ◽  
Vikram Kestens
Keyword(s):  
Zeta Potential ◽  
Particle Tracking ◽  
Colloidal Stability ◽  
Optical Methods ◽  
Intermediate Precision ◽  
Electrophoretic Light Scattering ◽  
Measurement Uncertainties ◽  
Development And Validation ◽  
Direct Implementation

Zeta potential is frequently used to examine the colloidal stability of particles and macromolecules in liquids. Recently, it has been suggested that zeta potential can also play an important role for grouping and read-across of nanoforms in a regulatory context. Although the measurement of zeta potential is well established, only little information is reported on key metrological principles such as validation and measurement uncertainties. This contribution presents the results of an in-house validation of the commonly used electrophoretic light scattering (ELS) and the relatively new particle tracking analysis (PTA) methods. The performance characteristics were assessed by analyzing silica and polystyrene reference materials. The ELS and PTA methods are robust and have particle mass working ranges of 0.003 mg/kg to 30 g/kg and 0.03 mg/kg to 1.5 mg/kg, respectively. Despite different measurement principles, both methods exhibit similar uncertainties for repeatability (2%), intermediate precision (3%) and trueness (4%). These results confirm that the developed methods can accurately measure the zeta potential of silica and polystyrene particles and can be transferred to other laboratories that analyze similar types of samples. If direct implementation is impossible, the elaborated methodologies may serve as a guide to help laboratories validating their own methods.

Research and Progress of Electromagnetic Coil Gun Ranging

2014 ◽  
Vol 1049-1050 ◽  
pp. 1176-1180
Author(s):  
Chao Qi ◽  
Ye Wang ◽  
Wei Jian Liu ◽  
Yong Quan
Keyword(s):  
Great Influence ◽  
Energy Conversion Efficiency ◽  
Optical Methods ◽  
Laser Scattering ◽  
Advantages And Disadvantages ◽  
Electromagnetic Coil ◽  
Position Detection ◽  
Multi Stage ◽  
Optimum Position ◽  
Scattering Measurement

The armature trigger position of multi-stage electromagnetic coil gun has great influence on the exit velocity of projectile. The energy conversion efficiency of the coil gun can be improved effectively if the armature is triggered in the optimum position. So it is important to detect the projectile position in time. Several typical electrical and optical methods for position detection are summarized in this paper. The advantages and disadvantages of each method are analyzed and evaluated. And a new laser scattering measurement method is proposed. Results show that optical detection method is simple and easy to implement, but it is susceptible to environmental impacts.

XXV.—The Determination of Temperature Gradients over the Greenland Ice Sheet by Optical Methods

1957 ◽  
Vol 64 (4) ◽  
pp. 381-397
Author(s):  
R. A. Hamilton
Keyword(s):  
Temperature Gradient ◽  
Ice Sheet ◽  
Greenland Ice Sheet ◽  
Temperature Gradients ◽  
Lower Atmosphere ◽  
Optical Methods ◽  
Snow Surface ◽  
Vertical Angle ◽  
Gradient Measurements

SynopsisThe temperature gradient in the lower atmosphere can be directly determined by measuring the optical refractive index of the air. This method is suitable for use on the Greenland ice sheet where errors introduced by water vapour are small, and where the strong solar radiation reflected by the snow surface makes it difficult to measure temperature differences over height differences of about I metre.The refraction was measured by observing the apparent vertical angle of each of a set of targets at distances up to 4 km. from a theodolite. The refraction was found to vary linearly with the distance of the target. The true vertical angle to the targets was determined when a second theodolite was available and reciprocal sights could be taken with it from the site of target to the fixed theodolite. The true vertical angle varied with time due to slow descent of the theodolite as the firn slumped; a correction for this was made. The standard error of the temperature gradient measurements was about 1.5 × 10−2 C.° per metre. It is considered that the method could be developed and improved so that over a range of only 100 metres temperature gradients could be measured to an accuracy of about 0·1° C. per metre.

scholarly journals Comparative characteristics of the petrographic composition and quality of coal series С12 and С13 of the Prydniporovia Block

2021 ◽  
Vol 30 (1) ◽  
pp. 145-152
Author(s):  
Vyacheslav S. Savchuk ◽  
Vasyl F. Prykhodchenko ◽  
Dmytro V. Prykhodchenko ◽  
Valeriia V. Tykhonenko
Keyword(s):  
Volatile Matter ◽  
Matter Content ◽  
Coal Seams ◽  
Combustion Heat ◽  
Petrographic Composition ◽  
Genetic Features ◽  
History Of ◽  
Coal Composition ◽  
Technological Indices

Taking into consideration the whole history of geological development of the Western Donbas, data on composition and grade of С12 series coal involved information about the geotectonic development of the Basin. To satisfy the objectives, a system of research methods, covering petrographic, computational, statistical, chronological, comparative and other methods, has been applied. In the process of identification of the petrographic composition and grade of series С12coal on the territory of the Prydniprovia Block, and determination of lateral regularities of their change as well as change in stratigraphic section of the Lower Carboniferous, data of petrographic as well as chemical and technological indices of the coal seam c1 were generalized along with data of all seams of С13 series. The activities helped define genetic features of series С12coal as well as stratigraphic and lateral regularities of changes in the coal composition. The differences in the petrographic composition as well as in the chemical and technological characteristics of series С12 and С13 are indicative of dissimilar conditions of formation of their peat depositions. It has been determined that compared with С13 series coal, the coal of С12 series contains more humidity and fewer mineral impurities. It is characterized by higher values of sulfur content, volatile-matter content, and combustion heat. The ultimate composition of coal seams of С12series is characterized by smaller values of carbon and oxygen contents as well as greater hydrogen content. The conclusions on common features and differences in the petrographic composition as well as chemical and technological features of coal seams of С12and С13 series, and regularities of their changes over the area of the seam occurrence was assessed.

scholarly journals Field test of available methods to measure remotely SO<sub>x</sub> and NO<sub>x</sub> emissions from ships

2014 ◽  
Vol 7 (8) ◽  
pp. 2597-2613 ◽  
Author(s):  
J. M. Balzani Lööv ◽  
B. Alfoldy ◽  
L. F. L. Gast ◽  
J. Hjorth ◽  
F. Lagler ◽  
...  
Keyword(s):  
Field Studies ◽  
Emission Factors ◽  
Sulphur Content ◽  
Nox Emission ◽  
Optical Methods ◽  
Optical Absorption Spectroscopy ◽  
Open Sea ◽  
Remote Measurements ◽  
Convenient Technique

Abstract. Methods for the determination of ship fuel sulphur content and NOx emission factors based on remote measurements have been compared in the harbour of Rotterdam and compared to direct stack emission measurements on the ferry Stena Hollandica. The methods were selected based on a review of the available literature on ship emission measurements. They were either optical (LIDAR, Differential Optical Absorption Spectroscopy (DOAS), UV camera), combined with model-based estimates of fuel consumption, or based on the so called "sniffer" principle, where SO2 or NOx emission factors are determined from simultaneous measurement of the increase of CO2 and SO2 or NOx concentrations in the plume of the ship compared to the background. The measurements were performed from stations at land, from a boat and from a helicopter. Mobile measurement platforms were found to have important advantages compared to the land-based ones because they allow optimizing the sampling conditions and sampling from ships on the open sea. Although optical methods can provide reliable results it was found that at the state of the art level, the "sniffer" approach is the most convenient technique for determining both SO2 and NOx emission factors remotely. The average random error on the determination of SO2 emission factors comparing two identical instrumental set-ups was 6%. However, it was found that apparently minor differences in the instrumental characteristics, such as response time, could cause significant differences between the emission factors determined. Direct stack measurements showed that about 14% of the fuel sulphur content was not emitted as SO2. This was supported by the remote measurements and is in agreement with the results of other field studies.

Size Determination of Latex Particles by Optical Methods

1979 ◽  
Vol 18 (6) ◽  
pp. 1053-1059
Author(s):  
Kohei Ametani ◽  
Hiizu Fujita
Keyword(s):  
Optical Methods ◽  
Size Determination ◽  
Latex Particles
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