scholarly journals Vertical Zoning in Hydrothermal U-Ag-Bi-Co-Ni-As Systems: A Case Study from the Annaberg-Buchholz District, Erzgebirge (Germany)

2021 ◽  
Author(s):  
Marie Guilcher ◽  
Anna Schmaucks ◽  
Joachim Krause ◽  
Gregor Markl ◽  
Jens Gutzmer ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Thermodynamic Calculations ◽  
Ore Formation ◽  
Precipitation Mechanism ◽  
General Importance ◽  
Hydrothermal Remobilization ◽  
Homogenization Temperatures ◽  
Vertical Zoning ◽  
Made In

Abstract The Annaberg-Buchholz district is a classic occurrence of hydrothermal five-element (U-Ag-Bi-Co-Ni-As) veins in the Erzgebirge (Germany) with an historic production of ~8,700 metric tons (t) Co ore, 496 t U ore, and 26.9 t Ag. Multiple mineralization stages are recognized in polyphase veins hosted by Proterozoic paragneiss. Fluorite-barite-Pb-Zn mineralization occurs across the entire vertical profile of the district, whereas U and five-element stages are restricted to the upper 400 m below surface, coinciding with a graphite-rich gneiss lithology. Here, we present field and petrographic observations, electron probe microanalysis and fluid inclusion data, as well as thermodynamic calculations to characterize five-element and fluorite-barite-Pb-Zn associations, and to constrain the origin of the vertical zoning in the Annaberg-Buchholz district. Microthermometric analyses of fluid inclusions related to the fluorite-barite-Pb-Zn stage yield homogenization temperatures between 78° and 140°C and salinities between 21.9 and 27.7 equiv wt % (NaCl-CaCl2). A correlation of fluid inclusion Na/(Na + Ca) ratios with salinity suggests fluid mixing as a likely precipitation mechanism and relates ore formation tentatively to regional tectonics of the Mesozoic opening of the Atlantic. Thermodynamic calculations indicate that U is more sensitive to reduction than As, predicting that arsenide minerals are precipitated more distally relative to uraninite upon reduction along the fluid-flow path. This implies that the observed vertical zoning is not a primary feature but is the result of hydrothermal remobilization. The observations made in the Annaberg-Buchholz district have general importance to the understanding of U-rich five-element mineralization and may be relevant for exploration targeting in unconformity-related U deposits.

scholarly journals Non-destructive handheld XRF study of archaeological composite silver objects—the case study of the late Roman Seuso Treasure

2021 ◽  
Vol 13 (5) ◽  
Author(s):  
Viktória Mozgai ◽  
Bernadett Bajnóczi ◽  
Zoltán May ◽  
Zsolt Mráv
Keyword(s):  
Fluorescence Analysis ◽  
The Body ◽  
High Quality ◽  
X Ray ◽  
Composite Objects ◽  
Mechanical Attachment ◽  
Non Destructive ◽  
Made In ◽  
Late Roman

AbstractThis study details the non-destructive chemical analysis of composite silver objects (ewers, situlas, amphora and casket) from one of the most significant late Roman finds, the Seuso Treasure. The Seuso Treasure consists of fourteen large silver vessels that were made in the fourth–early fifth centuries AD and used for dining during festive banquets and for washing and beautification. The measurements were systematically performed along a pre-designed grid at several points using handheld X-ray fluorescence analysis. The results demonstrate that all the objects were made from high-quality silver (above 90 wt% Ag), with the exception of the base of the Geometric Ewer B. Copper was added intentionally to improve the mechanical properties of soft silver. The gold and lead content of the objects shows constant values (less than 1 wt% Au and Pb). The chemical composition as well as the Bi/Pb ratio suggests that the parts of the composite objects were manufactured from different silver ingots. The ewers were constructed in two ways: (i) the base and the body were made separately, or (ii) the ewer was raised from a single silver sheet. The composite objects were assembled using three methods: (i) mechanical attachment; (ii) low-temperature, lead-tin soft solders; or (iii) high-temperature, copper-silver hard solders. Additionally, two types of gilding were revealed by the XRF analysis, one with remnants of mercury, i.e. fire-gilding, and another type without remnants of mercury, presumably diffusion bonding.

scholarly journals Influence of the variability of the odour emission rate on its impact range: a case study of the selected industrial source

2019 ◽  
Vol 100 ◽  
pp. 00070 ◽  
Author(s):  
Elżbieta Romanik ◽  
Yaroslav Bezyk ◽  
Marcin Pawnuk ◽  
Urszula Miller ◽  
Agnieszka Grzelka
Keyword(s):  
Emission Rate ◽  
Dispersion Model ◽  
Grid Size ◽  
Model Calculations ◽  
Gas Treatment ◽  
Industrial Source ◽  
Odour Concentration ◽  
Made In ◽  
Dynamic Olfactometry

Odour concentration measurements in a chosen industrial source were made in this study using the method of dynamic olfactometry. The two different scenarios considered the variation of the odour emission rate as input for the dispersion model were compared for the period 2017 (before installation of the equipment for gas treatment) and 2018 (after implementation of purifying technologies). In this paper the odour impact range was determined by applying model calculations conducted in the Polish reference dispersion model – OPERAT FB software for the grid size 2 x 2 km. The conducted research shows a significant improvement in the odour impact range of chosen industrial source in year 2018 compared to 2017.

Introducing Problem-based Learning to Special Needs Dentistry—A Case Study

2002 ◽  
Vol os9 (1) ◽  
pp. 9-13 ◽  
Author(s):  
Raman Bedi ◽  
Jackie A Champion ◽  
Roger Davies
Keyword(s):  
Special Needs ◽  
Problem Based Learning ◽  
Chi Square ◽  
Training And Education ◽  
Mixed Response ◽  
Conventional Teaching ◽  
The Subject ◽  
Better Than ◽  
Made In

Introduction In order to promote training and education in special-needs dentistry an attempt was made to introduce problem-based learning (PBL) as a method of postgraduate dental education. The aim of this paper was to review the principles of PBL and report on a case study using this methodology. Method The case study was of a PBL session, on the subject of ‘problems of obtaining appropriate dental care for people with epilepsy’, undertaken at a national conference. Delegates were asked to complete a pre- and post-session questionnaire on PBL and their attitudes to the session. Results The session received a mixed response. Only 33 (35%) thought the session was valuable and only 20 (31%) thought it was better than conventional teaching methods and yet over half (55%) said they would like to attend more PBL in special-needs dentistry. Professionals complementary to dentistry were more likely to find the PBL session of value and to prefer the method to a more conventional format than dentists were (chi-square=5.5, df=1, p<0.05 and chi-square=5.9, df=1, p<0.05 respectively). Conclusion Valuable feedback was received from delegates. This will enable improvements to be made in future courses so that the effectiveness of PBL can be optimised.

The "Right to Die": A Case Study in American Lawmaking*

1996 ◽  
Vol 3 (1) ◽  
pp. 49-74
Author(s):  
Alan Meisel
Keyword(s):  
Legal System ◽  
Right To Die ◽  
Judicial Process ◽  
Clinical Issue ◽  
The Press ◽  
American Law ◽  
American Legal System ◽  
The Right ◽  
Made In

AbstractIn the 20 years that have passed since the Karen Quinlan case exposed a simmering clinical issue to the light of day — more precisely, to the press and to judicial process — a consensus has developed in American law about how end-of-life decisionmaking should occur. To be sure, there are dissenting voices from this consensus, but they are often (though not always) about minor issues. By illustrating how this consensus has evolved, this paper explores how law is made in the American legal system and the roles that different legal and extra-legal institutions play in lawmaking.

Case Study Comparison: Limitations in Telehealth Relating to Poverty and Family Support

2021 ◽  
Vol 42 (02) ◽  
pp. 158-164
Author(s):  
Lindsey E. Jorgensen ◽  
Rachel E. Barrett
Keyword(s):  
Family Support ◽  
Pediatric Patients ◽  
Internet Access ◽  
Smart Devices ◽  
Internet Connection ◽  
The Third ◽  
Global Pandemic ◽  
Internet Connections ◽  
Made In

AbstractTelehealth appointments have grown in popularity due to the COVID-19 global pandemic. Three cases presented in this article show several different perspectives where telehealth was utilized. For the first patient, appointments were successfully completed via telehealth; however, the patient's family opted to continue with an unsecure internet connection at a local laundromat. For the second patient, a stable internet connection could not be obtained in his home, thus making telehealth appointments unavailable. The caregiver of this patient ended up driving to the clinic to have adjustments made in person. For the third patient, telehealth appointments were unavailable due to unstable internet connections as well as difficulty setting up video interpreting services. These cases highlight the idea that telehealth can be incredibly beneficial, when used correctly. For some, the option to attend appointments virtually gives them access to specialists that otherwise may not be available. For other patients, aspects such as access to smart devices and steady internet access must be considered to ensure a successful connection. The hope is that this article sheds light on some of the potential setbacks that can come from the use of telehealth appointments in a practice and provides discussion regarding for whom telehealth may be appropriate, even in pediatric patients. After reading this article, readers should be able to discuss ways in which there could be solutions for these barriers that may prevent some patients from utilizing these types of virtual appointments.

Translation policy

2021 ◽  
Vol 7 (3) ◽  
pp. 339-369
Author(s):  
Alireza Jazini
Keyword(s):  
End Users ◽  
Reception Theory ◽  
Audience Reception ◽  
Policy Network ◽  
Top Down ◽  
Bottom Up ◽  
Policy Model ◽  
Subsequent Research ◽  
Made In

Abstract The translation policy model by González Núñez (2013, 475) comprises three elements, namely “translation management”, “translation practices”, and “translation beliefs”. While the first two elements of this model are straightforward and easy to study in top-down approaches, translation beliefs can relate both to policymakers and policy receivers. However, the distinction has not been clearly made in this model and the element of translation beliefs has been chiefly treated in the literature as though it comes from the top levels of policymaking, hence overlooking the bottom-up aspects of it (see González Núñez 2014, 2016; Li et al. 2017). In order to improve this model, the present paper draws on the audience reception theory (Hall 1973), and shows that the current translation policy model requires a fourth element that I would call ‘translation reception’. The paper draws on the findings of a reception-oriented case study on translation policies in provincial broadcasting in Iran. This study argues that a more inclusive model of translation policy should not only include the authority-level elements of translation management, translation practices, and translation beliefs, but also the element of translation reception on the part of policy receivers. This way, I hope, the end users’ involvement in and contribution to the translation policy network will not be overlooked in subsequent research.

The Traceability of Construction and Demolition Waste in Flanders via Blockchain Technology: A Match Made in Heaven?

2021 ◽  
Vol 18 (4) ◽  
pp. 347-369
Author(s):  
Jonas Voorter ◽  
Christof Koolen
Keyword(s):  
Circular Economy ◽  
Construction And Demolition Waste ◽  
Waste Processing ◽  
Construction Sector ◽  
Sustainable Society ◽  
Demolition Waste ◽  
Blockchain Technology ◽  
Legal Case ◽  
Made In

Abstract The construction sector plays a crucial role in the transition to a circular economy and a more sustainable society. With this objective in mind, Flanders – the Dutch speaking part of Belgium – makes use of a traceability procedure for construction and demolition waste in order to guarantee that value can be derived from downstream waste processing activities. This article takes this traceability procedure as a legal case study and examines if the use of blockchain technology could lead to even stronger supply chains, better data management, and, more generally, a smoother transition to circular practices in the construction sector.

scholarly journals Precious Metal Enrichment at the Myra Falls VMS Deposit, British Columbia, Canada

Geosciences ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 422
Author(s):  
Daniel Marshall ◽  
Carol-Anne Nicol ◽  
Robert Greene ◽  
Rick Sawyer ◽  
Armond Stansell ◽  
...  
Keyword(s):  
Fluid Inclusion ◽  
Precious Metal ◽  
Metal Enrichment ◽  
Sea Floor ◽  
North West ◽  
Low Salinity ◽  
Volcanogenic Massive Sulphide ◽  
Igneous Fluids ◽  
Homogenization Temperatures ◽  
Water Depths

Gold, present as electrum, in the Battle Gap, Ridge North-West, HW, and Price deposits at the Myra Falls mine, occurs in late veinlets cutting the earlier volcanogenic massive sulphide (VMS) lithologies. The ore mineral assemblage containing the electrum comprises dominantly galena, tennantite, bornite, sphalerite, chalcopyrite, pyrite, and rarely stromeyerite, and is defined as an Au-Zn-Pb-As-Sb association. The gangue is comprised of barite, quartz, and minor feldspathic volcanogenic sedimentary rocks and clay, comprised predominantly of kaolinite with subordinate illite. The deposition of gold as electrum in the baritic upper portions of the sulphide lenses occurs at relatively shallow water depths beneath the sea floor. Primary, pseudosecondary, and secondary fluid inclusions, petrographically related to gold, show boiling fluid inclusion assemblages in the range of 123 to 173 °C, with compositions and eutectic melt temperatures consistent with seawater at approximately 3.2 wt % NaCl equivalent. The fluid inclusion homogenization temperatures are consistent with boiling seawater corresponding to water depths ranging from 15 to 125 m. Slightly more dilute brines corresponding to salinities of approximately 1 wt % NaCl indicate that there is input from very low-salinity brines, which could represent a transition from subaqueous VMS to epithermal-like conditions for precious metal enrichment, mixing with re-condensed vapor, or very low-salinity igneous fluids.

scholarly journals The Quality of Life of Suburbanities: A Case Study of the Gdańsk Agglomeration

2010 ◽  
Vol 14 (14) ◽  
pp. 91-101
Author(s):  
Grzegorz Masik
Keyword(s):  
Quality Of Life ◽  
Local Government ◽  
Public Transport ◽  
Local Governments ◽  
Public Spaces ◽  
Relative Importance ◽  
Made In

The Quality of Life of Suburbanities: A Case Study of the Gdańsk Agglomeration The article explains the meaning of the concept of ‘quality of life’, placing emphasis on its subjective dimension. As the concept is more and more discussed in the literature, the author intends to examine the satisfaction within public spaces for which local government is responsible. According to research made in Canada it is worth measuring not only satisfaction as such but also the importance of its constituent dynamics. Therefore, a survey made in the suburbs of the Gdańsk agglomeration asked respondents about their satisfaction with public transport, roads, environment, etc., including questions about the relative importance of such issues. The combination of satisfaction and importance provide the overall quality of life. At the end of the paper the author considers if there is a chance to improve the quality of life through a brief analysis of local governments expenditure.

scholarly journals Fluid Inclusion and Oxygen Isotope Constraints on the Origin and Hydrothermal Evolution of the Haisugou Porphyry Mo Deposit in the Northern Xilamulun District, NE China

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Qihai Shu ◽  
Yong Lai
Keyword(s):  
Fluid Inclusion ◽  
Meteoric Water ◽  
Early Time ◽  
Low Oxygen ◽  
Potassic Alteration ◽  
Low Salinity ◽  
Oxygen Isotopic ◽  
Homogenization Temperatures ◽  
Porphyry Mo Deposit ◽  
Positive Correlations

The Haisugou porphyry Mo deposit is located in the northern Xilamulun district, northeastern China. Based on alteration and mineralization styles and crosscutting relationships, the hydrothermal evolution in Haisugou can be divided into three stages: an early potassic alteration stage with no significant metal deposition, a synmineralization sericite-chlorite alteration stage with extensive Mo precipitation, and a postmineralization stage characterized by barren quartz and minor calcite and fluorite. The coexistence of high-salinity brine inclusions with low-salinity inclusions both in potassic alteration stage (~440°C) and locally in the early time of mineralization stage (380–320°C) indicates the occurrence of fluid boiling. The positive correlations between the homogenization temperatures and the salinities of the fluids and the low oxygen isotopic compositions (δ18Ofluid < 3‰) of the syn- to postmineralization quartz together suggest the mixing of magmatic fluids with meteoric water, which dominated the whole mineralization process. The early boiling fluids were not responsible for ore precipitation, whereas the mixing with meteoric water, which resulted in temperature decrease and dilution that significantly reduced the metal solubility, should have played the major role in Mo mineralization. Combined fluid inclusion microthermometry and chlorite geothermometer results reveal that ore deposition mainly occurred between 350 and 290°C in Haisugou.

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