scholarly journals In-situ gamma-ray survey of rare-earth tailings dams – A case study in Baotou and Bayan Obo Districts, China

2016 ◽  
Vol 151 ◽  
pp. 304-310 ◽  
Author(s):  
Baochuan Li ◽  
Nanping Wang ◽  
Jianhua Wan ◽  
Shengqing Xiong ◽  
Hongtao Liu ◽  
...  
Keyword(s):  
Rare Earth ◽  
Gamma Ray ◽  
Tailings Dams ◽  
Bayan Obo ◽  
Rare Earth Tailings

scholarly journals Denitrification performance of rare earth tailings-based catalysts

2019 ◽  
Vol 8 (1) ◽  
pp. 865-872 ◽  
Author(s):  
Zhenfeng Wang ◽  
Yanan Huang ◽  
Huijuan Luo ◽  
Zhijun Gong ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Rare Earth ◽  
High Performance ◽  
Acid Leaching ◽  
Performance Tests ◽  
Temperature Range ◽  
Catalytically Active ◽  
Bayan Obo ◽  
Roasting Temperature ◽  
Rare Earth Tailings ◽  
Active Substances

Abstract Rare earth tailings from the Bayan Obo mine are rich in rare earth, iron, and other catalytically active substances. In this study, Na2CO3 and Ca(OH)2 were mixed with rare earth tailings, roasted, and the tailings modified by HCl-citric acid leaching and pickling to prepare high-performance rare earth tailings-based denitrification catalysts. Denitrification performance tests show that, in the temperature range 700°C~900°C, the alkali and acid co-processed modified tailings sample gave the best catalytic denitrification performance. XRD, SEM, and H2-TPR analyses show that, compared with raw ore samples, Fe activity sites increased after alkali and acid co-treatment. Cracks and holes appeared on the surface of the sample, and the reduction temperature range was broadened. XPS analysis showed that Fe coexisted in the forms Fe2+ and Fe3+, and Ce in the forms Ce3+ and Ce4+. At a rare earth tailings microwave roasting temperature of 500°C, NO concentration of 500 ppm, CO/NO ratio 4:1, and reaction temperature of 900°C, the denitrification efficiency of the catalyst was optimal, at up to 96.2%. In this study, a relatively green and pollution-free method was used to prepare catalysts, which can provide reference for solving the problem of rare earth tailings accumulation.

Using in situ gamma ray spectrometry (GRS) exploration of buried archaeological structures: A case study from NW Spain

2018 ◽  
Vol 34 ◽  
pp. 247-254 ◽  
Author(s):  
Jorge Sanjurjo-Sánchez ◽  
Carlos Arce Chamorro ◽  
Carlos Alves ◽  
Jose Carlos Sánchez-Pardo ◽  
Rebeca Blanco-Rotea ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Gamma Ray Spectrometry ◽  
Nw Spain

Geostatistical Mapping of Cs-137 Contamination Depth in Building Structures by Integrating ISOCS Measurements of Different Spatial Supports

2013 ◽  
Author(s):  
B. Rogiers ◽  
S. Boden ◽  
D. Jacques
Keyword(s):  
Radioactive Waste ◽  
Gamma Ray ◽  
Future Application ◽  
Building Structures ◽  
Gamma Ray Spectroscopy ◽  
Reliable Methods

Reliable methods to determine the contamination depth in nuclear building structures are very much needed for minimizing the radioactive waste volume and the decontamination workload. This paper investigates the geostatistical integration of in situ gamma-ray spectroscopy measurements of different spatial supports. A case study is presented from the BR3 decommissioning project, yielding an estimated reduction of waste volume of ∼35%, and recommendations are made for future application of the proposed methodology.

scholarly journals Rare-earth metal diisopropylamide-catalyzed intramolecular hydroamination

2016 ◽  
Vol 45 (41) ◽  
pp. 16393-16403 ◽  
Author(s):  
Tatiana Spallek ◽  
Reiner Anwander
Keyword(s):  
Rare Earth ◽  
Alkali Metal ◽  
Rare Earth Metal ◽  
Earth Metal ◽  
Donor Solvent ◽  
Catalyst Formation

Well-defined rare-earth metal diisopropylamide complexes provide an exemplary case study to investigate the effect of donor solvent, alkali metal, chloro co-ligands, and in situ catalyst formation.

SenCity – Evaluating Users’ Experiences of Intelligent Lighting for Well-Being in Smart Cities

2018 ◽  
pp. 60-67
Author(s):  
Henrika Pihlajaniemi ◽  
Anna Luusua ◽  
Eveliina Juntunen
Keyword(s):  
Case Studies ◽  
Smart City ◽  
Smart Cities ◽  
Well Being ◽  
Evaluation Methods ◽  
Data Analyses ◽  
Sense Of Security ◽  
System Data

This paper presents the evaluation of usersХ experiences in three intelligent lighting pilots in Finland. Two of the case studies are related to the use of intelligent lighting in different kinds of traffic areas, having emphasis on aspects of visibility, traffic and movement safety, and sense of security. The last case study presents a more complex view to the experience of intelligent lighting in smart city contexts. The evaluation methods, tailored to each pilot context, include questionnaires, an urban dashboard, in-situ interviews and observations, evaluation probes, and system data analyses. The applicability of the selected and tested methods is discussed reflecting the process and achieved results.

Site specific agricultural soil management with the use of new technologies

2013 ◽  
Vol 16 (1) ◽  
pp. 59-67
Keyword(s):  
New Technologies ◽  
Digital Interface ◽  
Appropriate Treatment ◽  
Wide Range ◽  
Soil Variation ◽  
Soil Information ◽  
Remote Sensing Techniques ◽  
Agricultural Areas

<p>The Soil Science Institute of Thessaloniki produces new digitized Soil Maps that provide a useful electronic database for the spatial representation of the soil variation within a region, based on in situ soil sampling, laboratory analyses, GIS techniques and plant nutrition mathematical models, coupled with the local land cadastre. The novelty of these studies is that local agronomists have immediate access to a wide range of soil information by clicking on a field parcel shown in this digital interface and, therefore, can suggest an appropriate treatment (e.g. liming, manure incorporation, desalination, application of proper type and quantity of fertilizer) depending on the field conditions and cultivated crops. A specific case study is presented in the current work with regards to the construction of the digitized Soil Map of the regional unit of Kastoria. The potential of this map can easily be realized by the fact that the mapping of the physicochemical properties of the soils in this region provided delineation zones for differential fertilization management. An experiment was also conducted using remote sensing techniques for the enhancement of the fertilization advisory software database, which is a component of the digitized map, and the optimization of nitrogen management in agricultural areas.</p>

China and the Geopolitics of Rare Earths

2017 ◽  
Author(s):  
Sophia Kalantzakos
Keyword(s):  
Rare Earth ◽  
Rare Earths ◽  
Resource Competition ◽  
Renewable Energy Sources ◽  
High Tech ◽  
Trade Dispute ◽  
Policy Responses ◽  
Economic Statecraft ◽  
The Rare Earth

In 2010, because of a geopolitical incident between China and Japan, seventeen elements of the periodic table known as rare earths became notorious overnight. An “unofficial” and temporary embargo of rare-earth shipments to Japan alerted the world to China’s near monopoly position on the production and export of these indispensable elements for high-tech, defense, and renewable energy sources. A few months before the geopolitical confrontation, China had chosen to substantially cut export quotas of rare earths. Both events sent shockwaves across the markets, and rare-earth prices skyrocketed, prompting reactions from industrial nations and industry itself. The rare-earth crisis is not a simple trade dispute, however. It also raises questions about China’s use of economic statecraft and the impacts of growing resource competition. A detailed and nuanced examination of the rare-earth crisis provides a significant and distinctive case study of resource competition and its spill-over geopolitical effects. It sheds light on the formulation, deployment, longevity, effectiveness, and, perhaps, shortsightedness of policy responses by other industrial nations, while also providing an example of how China might choose to employ instruments of economic statecraft in its rise to superpower status.

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