The morphology, mineralogy, and behavior of "fine-grained" gold from placer deposits of Alberta: sampling and implications for mineral exploration: Discussion

1987 ◽  
Vol 24 (7) ◽  
pp. 1502-1502
Author(s):  
S. J. Day ◽  
W. K. Fletcher
Keyword(s):  
Mineral Exploration ◽  
Fine Grained ◽  
Placer Deposits ◽  
And Behavior

The morphology, mineralogy, and behavior of u "fine-grained" gold from placer deposits of Alberta: sampling and implications for mineral exploration

1986 ◽  
Vol 23 (11) ◽  
pp. 1662-1672 ◽  
Author(s):  
L. Giusti
Keyword(s):  
Mineral Exploration ◽  
Sampling Procedure ◽  
Stream Sediments ◽  
Shape Factors ◽  
Athabasca River ◽  
Fine Grained ◽  
The North ◽  
Placer Deposits ◽  
Routine Sampling ◽  
And Behavior

The morphology of a large number of gold grains from stream sediments of the North Saskatchewan River and the Athabasca River was studied, together with the partitioning of the placer gold between various size fractions.Two major morphological varieties of gold were observed: (1) flaky, scaly gold, with folded and hammered edges, and with crystals or crystal faces still visible on the surface; and (2) "sandwiched," droplike particles, sometimes toroidal. About 5% of both types of gold were found to be coated with "new," secondary gold.The size of the majority of the gold grains studied varies between 0.500 and 0.010 mm. The most frequent size range in the North Saskatchewan River is 0.125–0.250 mm, whereas in the Athabasca River it is 0.063–0.125 mm. An important fraction of the gold from both rivers is smaller than 0.063 mm.The average Corey shape factor (CSF) of the gravity-recovered gold increases as the particle size decreases, whereas the gold grains lost to the tailings indicate very low average shape factors (i.e., high degree of flattening). This apparent increase in CSF for the smallest fractions recovered when using mechanical techniques is due to the fact that the flaky gold particles are more difficult to recover than the more spherical ones. Moreover, the presence of a gold-rich rim on all the gold grains increases their hydrophobicity.The sampling procedure to be adopted in Alberta and, more generally, in glaciated terrains is discussed. In particular, the use of the −63 μm fraction for routine sampling of stream sediments is suggested.

scholarly journals Application of the Fine-Grained Soil Prospecting Method in Typical Covered Terrains of Northern China

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1383
Author(s):  
Hanliang Liu ◽  
Bimin Zhang ◽  
Xueqiu Wang ◽  
Zhixuan Han ◽  
Baoyun Zhang ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Mineral Resources ◽  
Northern China ◽  
Gobi Desert ◽  
Test Results ◽  
Fine Grained ◽  
Ore Body ◽  
Ore Bodies ◽  
Fine Grained Soil ◽  
Body Location

In recent years, mineral resources near the surface are becoming scarce, causing focused mineral exploration on concealed deposits in covered terrains. In northern China, covered terrains are widespread and conceal bedrock sequences and mineralization. These represent geochemical challenges for mineral exploration in China. As a deep-penetrating geochemical technology that can reflect the information of deep anomalies, the fine-grained soil prospecting method has achieved ideal test results in arid Gobi Desert covered terrain, semi-arid grassland covered terrain, and alluvium soil covered terrain of northern China. The anomaly range indicated by the fine-grained soil prospecting method is very good with the known ore body location. The corresponding relationship can effectively indicate deep ore bodies and delineate anomalies in unknown areas. Overall, the fine-grained soil prospecting method can be applied to geochemical prospecting and exploration in covered terrains.

Modeling Secure 3D Web Applications

2011 ◽  
pp. 263-283 ◽  
Author(s):  
Krzysztof Walczak
Keyword(s):  
Web Applications ◽  
Fine Grained ◽  
Dynamic Composition ◽  
Novel Approach ◽  
Access Privileges ◽  
3D Scene ◽  
High Level ◽  
And Behavior ◽  
Content Modeling ◽  
3D Web

This chapter describes a novel approach to building 3D web applications, called Flex-VR, which can be used a basis for implementing security solutions. Two key elements of the approach are described: scene structuralization and content modeling. The scene structuralization enables decomposition of a 3D scene into independent geometrical and behavioral objects, called VR-Beans. Virtual scenes with rich interactivity and behavior can be dynamically created by combining sets of independent VR-Beans. The second element – the content model – is a generalized high-level description of the application content. The model enables efficient manipulation of content elements and dynamic composition of virtual scenes. Flex-VR provides a fine-grained semantically-rich content structure, which can be used as a basis for defining access privileges for users and groups. Five levels of user privileges definition in the Flex-VR approach are described. An application of Flex-VR in the cultural heritage domain is presented. Examples demonstrate how user privileges can be defined at all levels.

scholarly journals Prefrontal cortex modulates posterior alpha oscillations during top-down guided visual perception

2017 ◽  
Vol 114 (35) ◽  
pp. 9457-9462 ◽  
Author(s):  
Randolph F. Helfrich ◽  
Melody Huang ◽  
Guy Wilson ◽  
Robert T. Knight
Keyword(s):  
Visual Perception ◽  
Alpha Activity ◽  
Alpha Power ◽  
Top Down ◽  
Visual Stream ◽  
Alpha Oscillations ◽  
Fine Grained ◽  
Oscillatory Dynamics ◽  
Delta Activity ◽  
And Behavior

Conscious visual perception is proposed to arise from the selective synchronization of functionally specialized but widely distributed cortical areas. It has been suggested that different frequency bands index distinct canonical computations. Here, we probed visual perception on a fine-grained temporal scale to study the oscillatory dynamics supporting prefrontal-dependent sensory processing. We tested whether a predictive context that was embedded in a rapid visual stream modulated the perception of a subsequent near-threshold target. The rapid stream was presented either rhythmically at 10 Hz, to entrain parietooccipital alpha oscillations, or arrhythmically. We identified a 2- to 4-Hz delta signature that modulated posterior alpha activity and behavior during predictive trials. Importantly, delta-mediated top-down control diminished the behavioral effects of bottom-up alpha entrainment. Simultaneous source-reconstructed EEG and cross-frequency directionality analyses revealed that this delta activity originated from prefrontal areas and modulated posterior alpha power. Taken together, this study presents converging behavioral and electrophysiological evidence for frontal delta-mediated top-down control of posterior alpha activity, selectively facilitating visual perception.

Vulnerable Narcissism as Key Link Between Dark Triad Traits, Mental Toughness, Sleep Quality and Stress

2017 ◽  
Vol 41 (S1) ◽  
pp. S261-S261 ◽  
Author(s):  
H. Annen ◽  
C. Nakkas ◽  
D. Sadeghi Bahmani ◽  
M. Gerber ◽  
E. Holsboer-Trachsler ◽  
...  
Keyword(s):  
Sleep Quality ◽  
Perceived Stress ◽  
Dark Triad ◽  
Mental Toughness ◽  
Poor Sleep ◽  
Vulnerable Narcissism ◽  
Fine Grained ◽  
Competing Interest ◽  
And Behavior ◽  
The University

IntroductionThe concept of the Dark Triad (DT) consists of the dimensions of Machiavellianism, narcissism, and psychopathy, and has gained increased interest within the last 15 years for its predictive power to explain success in the fields of economy, politics, and professional sport. However, recent research suggests that the associations between DT and behavior are not as uniform as expected.AimsInvestigating the associations between DT traits and vulnerable narcissism, mental toughness, sleep quality, and stress perception.MethodsA total of 720 participants between 18 and 28 years took part in the study. The sample consisted of military cadres in the US (n = 238), Switzerland (n = 220), and of students from the university of Basel (n = 262). Participants completed self-rating questionnaires covering DT traits, mental toughness, vulnerable narcissism, sleep quality, and perceived stress.ResultsIrrespective of the sample, participants scoring high on vulnerable narcissism also reported higher DT traits, lower mental toughness, poor sleep quality, and higher scores on perceived stress.ConclusionsThe present pattern of results suggests a more fine-grained association between DT traits and further behavior, calling into question to what extent DT traits might be a predictor for greater success in the fields of economy, politics or elite sports. Specifically, vulnerable narcissism seems to be key for more unfavourable behavior.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Pb–Zn occurrences and their Pb-isotopic signatures bearing on metallogeny and mineral exploration—Paleozoic sedimentary rocks, northern Appalachians, Quebec

1988 ◽  
Vol 25 (11) ◽  
pp. 1777-1790 ◽  
Author(s):  
K. Schrijver ◽  
E. Marcoux ◽  
G. Beaudoin ◽  
J. Y. Calvez
Keyword(s):  
Continental Crust ◽  
Mineral Exploration ◽  
Sedimentary Rocks ◽  
Isotope Ratios ◽  
Isotopic Signature ◽  
Coarse Grained ◽  
Pb Isotope ◽  
Isotopic Signatures ◽  
Fine Grained ◽  
Quartz Veins

Galena Pb-isotope ratios of epithermal vein and disseminated sulfide occurrences in the Taconian Orogen and Siluro-Devonian basin cluster around 17.90–18.05 for 206Pb/204Pb and 37.70–38.00 for 208Pb/204Pb. The major source of Pb in most, if not all, occurrences is a fairly common continental crust, a characteristic found in published analyses of Grenville feldspar Pb. A southwest to northeast increase in galena 206Pb/204Pb ratios is ascribed to the supply of several types of detritus from Grenville basement during the Cambro-Ordovician: coarse-grained, K-feldspar-bearing in the southwest, grading into fine-grained phyllitic, and relatively more highly radiogenic in the northeast.Emplacement (i) of Pb–Zn–barite veins and disseminations, commonly of homogeneous crustal Pb-isotopic signature, was late Taconian; (ii) of Pb–Zn–quartz veins, of less homogeneous signature, was post-Taconian; and (iii) of Pb–Zn–carbonate veins, relatively highly radiogenic and commonly homogeneous, was late or post-Acadian. Signatures of the first-mentioned group seem to be most useful in exploration.

scholarly journals Semantic-Based Requirements Content Management for Cloud Software

2015 ◽  
Vol 2015 ◽  
pp. 1-10 ◽  
Author(s):  
Jianqiang Hu ◽  
Songhao Jia ◽  
Keshou Wu
Keyword(s):  
Conditional Random Fields ◽  
Search Algorithm ◽  
Content Management ◽  
Coarse Grained ◽  
Breadth First Search ◽  
Software Complex ◽  
Fine Grained ◽  
Requirements Modeling ◽  
Behavioral Requirements ◽  
And Behavior

Cloud Software is a software complex system whose topology and behavior can evolve dynamically in Cloud-computing environments. Given the unpredictable, dynamic, elasticity, and on-demand nature of the Cloud, it would be unrealistic to assume that traditional software engineering can “cleanly” satisfy the behavioral requirements of Cloud Software. In particular, the majority of traditional requirements managements take document-centric approaches, which have low degree of automation, coarse-grained management, and limited support for requirements modeling activities. Facing the challenges, based on metamodeling frame called RGPS (Role-Goal-Process-Service) international standard, this paper firstly presents a hierarchical framework of semantic-based requirements content management for Cloud Software. And then, it focuses on some of the important management techniques in this framework, such as the native storage scheme, an ordered index with keywords, requirements instances classification based linear conditional random fields (CRFs), and breadth-first search algorithm for associated instances. Finally, a prototype tool called RGPS-RM for semantic-based requirements content management is implemented to provide supporting services for open requirements process of Cloud Software. The proposed framework applied to the Cloud Software development is demonstrated to show the validity and applicability. RGPS-RM also displays effect of fine-grained retrieval and breadth-first search algorithm for associated instance in visualization.

scholarly journals Transcranial Alternating Current and Random Noise Stimulation: Possible Mechanisms

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Andrea Antal ◽  
Christoph S. Herrmann
Keyword(s):  
Random Noise ◽  
Animal Experiments ◽  
Alternating Current ◽  
Brain Oscillations ◽  
Physiological Mechanisms ◽  
Fine Grained ◽  
Transcranial Random Noise Stimulation ◽  
Transcranial Alternating Current Stimulation ◽  
Network Simulations ◽  
And Behavior

Background. Transcranial alternating current stimulation (tACS) is a relatively recent method suited to noninvasively modulate brain oscillations. Technically the method is similar but not identical to transcranial direct current stimulation (tDCS). While decades of research in animals and humans has revealed the main physiological mechanisms of tDCS, less is known about the physiological mechanisms of tACS.Method. Here, we review recent interdisciplinary research that has furthered our understanding of how tACS affects brain oscillations and by what means transcranial random noise stimulation (tRNS) that is a special form of tACS can modulate cortical functions.Results. Animal experiments have demonstrated in what way neurons react to invasively and transcranially applied alternating currents. Such findings are further supported by neural network simulations and knowledge from physics on entraining physical oscillators in the human brain. As a result, fine-grained models of the human skull and brain allow the prediction of the exact pattern of current flow during tDCS and tACS. Finally, recent studies on human physiology and behavior complete the picture of noninvasive modulation of brain oscillations.Conclusion. In future, the methods may be applicable in therapy of neurological and psychiatric disorders that are due to malfunctioning brain oscillations.

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