Search results for "Metals"
showing 10 items of 2013 documents
Selective Synthesis of Z -Silyl Enol Ethers via Ni-Catalyzed Remote Functionalization of Ketones
2021
Journal of the American Chemical Society : JACS 143(22), 8375-8380 (2021). doi:10.1021/jacs.1c01797
The Janus Face of Political Experience
2018
Arendt’s concept of experience can contribute in important ways to the contemporary debates in political and feminist theory. However, while the notion is ubiquitous in Arendt’s thinking we lack an understanding of experience as a concept, as opposed to the impact of Arendt’s personal experiences on her thought. Drawing from her notes for “Political Experiences in the Twentieth Century,” the article seeks to enrich our understanding of the Janus-faced character of political experience. It emphasizes the importance of vicariousness, and argues that experience should be understood as a process of suffering, enduring, and re-experiencing events beyond our conscious control. The article further…
CHEMICAL CONTAMINATION OF BEE HONEY – IDENTIFYING SENSOR OF THE ENVIRONMENT POLLUTION
2005
Changes in the quality of bee honey are also caused by the contamination with micro-polluting agents, toxic to consumers. This research is about chemical contamination of honey. The honey used in this study was harvested from beehives situated in Copşa Mica (Sibiu region), famous for the ecological unbalances induced by the non-ferrous metal industry through pollution produced by SC Sometra SA. The amount of Pb, Cd and Zn contained in the samples harvested in the area specifi ed above have been determined using an atomic absorption spectrometer AAS. Amounts of heavy metals above the admitted limit by the OMS 975/88 have been discovered. The results suggested that honey could be used to dete…
Model research on the influence of green roofs on environmental parameters in urban agglomerations
2018
The intensive development of urban agglomerations in Poland and other European countries has rendered the growth of biologically active areas more important with respect the quality of the urban environment. Taking the rapidly rising prices of plots in city centers into consideration, it is worth noting the vast surfaces of building roofs that can be used as biologically active areas. The term green roof is to be understood as an open, overgrown surface on a multilayer roof of a building. Green roofs can only be made on a planar surface with an inclination of 2% to 30%. In accordance with the type of usage, construction factors and maintenance requirements, green roofs are typically defined…
The Influence of Urban Agglomeration on the Accumulation of Certain Heavy Metal Ions in Tansy (Tanacetum vulgare L.)
2020
Different compounds including toxic heavy metals ions have been used in various industrial branches for ages. Therefore, these compounds are nowadays often identified in the natural environment. Plants usually function like indirect transporters through which heavy metals, in the form of ions, infiltrate from the environment into the human and animals’ food chains. The present paper studied the influence of urban agglomeration on the accumulation of certain heavy metals in tansy. The content of heavy metals ions (Cr, Ni, Cd and Pb) was marked in the tansy leaves. Depending on the location of sampling, large variations in the heavy metal content were observed in the plant material. The resea…
Multi-elemental EDXRF mapping of polluted soil from former horticultural land.
2004
The distribution of major and trace elements was systematically investigated by use of energy dispersive X-ray fluorescence spectrometry (EDXRF) on a former horticultural soil. The purpose of the study was to combine mapping of soil element concentration levels with multivariate statistics for characterisation of soil metal pollution in relation to previous and present land use. A 1-ha study site was chosen from a former horticulture where a previous preliminary survey indicated increased concentration levels of toxic elements. The soil was sampled from the top 20 cm of the soil surface in a 10×10-m grid-like pattern covering the 1-ha study area. In addition, three soil profiles were studie…
Optimal Solutions for the Use of Sewage Sludge on Agricultural Lands
2021
The use of sewage sludge in agriculture decreases the pressure on landfills. In Romania, massive investments have been made in wastewater treatment stations, which have resulted in the accumulation of important quantities of sewage sludge. The presence of these sewage sludges coincides with large areas of degraded agricultural land. The aim of the present article is to identify the best technological combinations meant to solve these problems simultaneously. Adapting the quality and parameters of the sludge to the specificity of the land solves the possible compatibility problems, thus reducing the impact on the environment. The physico-chemical characteristics of the fermented sludge were …
Optimizing the Shape of Welded Constructions Made through the Technique “Temper Bead Welding”
2020
Welded constructions are subject to high stresses during operation. One solution for improving the behavior in exploitation of welded constructions in various cases is to use the welding technique “temper bead welding” (TBW). In the paper, the optimization of the geometry of the welded joints by the TBW technique was performed. Thus, corner welded joints made of S355 steel were analyzed. To make the welded joints, three layers of welding seams were deposited, and the intermediate layers were processed through cutting with various radii. To analyze the influence of the size of these rays on the behavior of welded constructions, a research program based on factorial experiences wa…
Task Planner for Robotic Disassembly of Electric Vehicle Battery Pack
2021
The rapidly growing deployment of Electric Vehicles (EV) put strong demands on the development of Lithium-Ion Batteries (LIBs) but also into its dismantling process, a necessary step for circular economy. The aim of this study is therefore to develop an autonomous task planner for the dismantling of EV Lithium-Ion Battery pack to a module level through the design and implementation of a computer vision system. This research contributes to moving closer towards fully automated EV battery robotic dismantling, an inevitable step for a sustainable world transition to an electric economy. For the proposed task planner the main functions consist in identifying LIB components and their locations, …
Evidencias de un recubrimiento de magnetita artificial en el armamento íbero
2011
A metallographic study of two pre-roman Iberian arms, affected by a cremation process, revealed the presence of an outer magnetite layer, providing highly protective properties. This layer is extraordinarily tenacious and of very homogeneous thickness, indicating an intentional manufacturing process rather than an accidental formation during the severe heating/cooling cycles the artefact suffered. Up to date, the intentional production of these types of layers has been attributed to a welding process of three different metallic sheets, here an alternative model is proposed, allowing, as could be simulated in the laboratory, the virtually exclusive formation of a magnetite coating.<br>…