Search results for " Metals"

Novel organo-modifier for thermally-stable polymer-layered silicate nanocomposites

2015

A new novel approach for the stabilisation of polymer-clay nanocomposites has been investigated based on reacting chemically an antioxidant function, a hindered phenol moiety, with an organic modifier based on a quaternary ammonium salt. The chemically linked antioxidant-containing organic modifier (AO-OM) was then introduced into natural montmorillonite (MMt) through a cation-exchange reaction resulting in antioxidant-containing organo-modified clay (AO-OM-MMt). The new antioxidant-containing modified clay, along with other organo-modified clays having a similar organo-modifier but without the reacted antioxidant, were characterised by spectroscopic, thermogravimetric and x-ray diffraction…

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

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…

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 …

Potential Carcinogens in Makeup Cosmetics

2023

Facial makeup cosmetics are commonly used products that are applied to the skin, and their ingredients come into contact with it for many years. Consequently, they should only contain substances that are considered safe or used within an allowable range of established concentrations. According to current European laws, all cosmetics approved for use should be entirely safe for their users, and the responsibility for this lies with manufacturers, distributors, and importers. However, the use of cosmetics can be associated with undesirable effects due to the presence of certain chemical substances. An analysis of 50 random facial makeup cosmetics commercially available on the European Union m…

Transformacja połączeń rtęć - substancje humusowe przy udziale Pleurotus ostreatus

2013

Phosphorus-Chalcogen Ring Expansion and Metal Coordination

2017

The reactivity of 4-membered (RPCh)2 rings (Ch = S, Se) that contain phosphorus in the +3 oxidation state is reported. These compounds undergo ring expansion to (RPCh)3 with the addition of a Lewis base. The 6-membered rings were found to be more stable than the 4-membered precursors, and the mechanism of their formation was investigated experimentally and by density functional theory calculations. The computational work identified two plausible mechanisms involving a phosphinidene chalcogenide intermediate, either as a free species or stabilized by a suitable base. Both the 4- and 6-membered rings were found to react with coinage metals, giving the same products: (RPCh)3 rings bound to the…

Translokacja metali ciężkich z gleby do wybranych gatunków warzyw

2016

Toksyczne działanie metali ciężkich na rośliny obserwowano od dawna, szczególnie na glebach o ich wysokim stężeniu. Efektem tego są zaburzenia procesów fizjologicznych roślin, obniżenie ilości i jakości plonu. Celem pracy było zbadanie procesu translokacji metali ciężkich z potencjalnie zanieczyszczonej gleby do powszechnie uprawianych warzyw – ogórka siewnego (Cucumis sativus L.), kalarepy (Brassica oleracea var. gongylodes L.), marchwi zwyczajnej (Daucus carota L.), fasoli szparagowej żółtostrąkowej i zielonostrąkowej (Phaseolus vulgaris L.) oraz buraka zwyczajnego (Beta vulgaris L.). Badane warzywa najbardziej były zanieczyszczone żelazem, a najmniej miedzią. Wyznaczone wartości współczy…