Search results for "contamination"
showing 10 items of 916 documents
Spin-restricted open-shell coupled-cluster theory for excited states
2000
Using a linear-response approach, the recently introduced spin-restricted coupled-cluster (SR-CC) theory is extended to the treatment of excited states of high-spin open-shell molecules. Explicit equations are given within the usual singles and doubles approximation and our implementation (within an existing spin–orbital code) is described. It is shown that in SR-CC theory, due to spin constraints, the spin-expectation value for the excited states calculated as corresponding energy derivatives always corresponds to the exact value. In addition, the SR-CC singles and doubles (SR-CCSD) approach is extended to include also the so-called pseudotriple excitations (best described as double excita…
Dealing with contaminants in Coulomb excitation of radioactive beams
2020
Abstract Data analysis of the Coulomb excitation experiment of the exotic 206Hg nucleus, recently performed at CERN’s HIE-ISOLDE facility, needs to account for the contribution to target excitation due to the strongly-present beam contaminant 130Xe. In this paper, the contamination subtraction procedure is presented.
SuperK-Gd Physics Potential
2018
In this section, all the measurements and potential searches that SuperK-Gd would be able to performed, are addressed. This section takes into account all the advantages of the 80% efficiency neutron tagging technique using gadolinium, but also the drawbacks that the inclusion of radioactive contamination could have in these measurements.
Shoot accumulation of several trace elements in native plant species from contaminated soils in the Peruvian Andes
2012
Abstract Metal mining gives access to very important resources but contributes to severe and diverse environmental problems. Until recently, little has been known about the remediation of mining sites in Latin America using metallophytes. The present study was designed to identify and characterize spontaneously growing heavy metal tolerant plant species in the area around the polymetallic Carolina mine in Hualgayoc (Cajamarca, Peru). The aim was to find species that are potentially useful for phytoremediation. Plants and soils were sampled and analysed for concentrations of As, Fe, Mn, Pb, Zn and Ti. The Translocation Factor (TF) and the Bioaccumulation Factor (BF) were determined and used …
Role of yeasts in table olive production
2008
Table olives are a traditional fermented vegetable of the Mediterranean countries, but their production and consumption are now spread all around the world. Yeasts can play a double role in this food. They are present throughout the fermentative process and it is generally accepted that they can produce compounds with important organoleptic attributes determining the quality and flavour of the final product. However, yeasts can also be spoilage microorganisms in olive fermentation/storage and packing causing gas pockets, swollen containers, cloudy brines and off-flavours and off-odours. Candida boidinii, Debaryomyces hansenii, Pichia anomala, P. membranifaciens, Rhodotorula glutinis and Sac…
Hygienic characteristics of radishes grown in soil contaminated with Stenotrophomonas maltophilia
2015
Background: Stenotrophomonas maltophilia is a plant growth-promoter. This bacterium is also implicated in human diseases. Thus, after the use of this bacterium in agriculture, the safety of the final products has to be verified. Due to the ubiquitous presence of S. maltophilia in soil, in this study a massive contamination was simulated to evaluate the growth and safety of Raphanus sativus L.. Results: Different inoculums and soil treatment conditions were tested. Soils were analysed weekly and the radishes at harvest for their microbial loads and presence/persistence of S. maltophilia LMG 6606. The concentration of the bacterium added in the different trials decreased during the first week…
Electrochemical production and use of chlorinated oxidants for the treatment of wastewater contaminated by organic pollutants and disinfection
2021
Abstract In the last years, an increasing attention has been devoted to the use of electrogenerated chlorinated oxidants for the treatment of wastewater polluted by recalcitrant organics and/or for the disinfection of water contaminated by pathogen microorganisms. In this review, more recent and relevant findings were presented and critically discussed. The main advantages and disadvantages of this technique were commented, including the potential formation of toxic chlorinated organic specie and of chlorate and perchlorate or the difficult selection of proper operative parameters, as well as the key points that should be addressed to enhance the use on an applicative scale.
Passive Sampling of Atmospheric Organic Contaminants
2012
The state of the art of passive sampling monitoring studies of atmospheric contaminants is reviewed in this chapter. The following passive samplers were considered: badge-type diffusive samplers; diffusive tubes; semi-permeable membrane devices; Radiello samplers; solid-phase microextraction fibers; polyurethane foam disks; XAD-2 passive air samplers; stir-bar samplers; polymer-coated glass surfaces; versatile, easy and rapid atmospheric monitor; and vegetation. A summary of the passive samplers used, sampling times, sampling rates, and analyte concentrations found is provided for different organic compounds, such as: carbonyl compounds, volatile compounds, polycyclic aromatic hydrocarbons,…
Metal Oxides for Removal of Arsenic Contaminants from Water
2021
Arsenic (As), one of the highest harmful pollutants found in drinking/groundwater, is owing to have unfavourable impacts, for example, skin disease, on human health. The new Environmental Protection Agency (EPA) assigned the maximum contaminations of arsenic in groundwater is 10μg/L, and several drinking water plants are needing extra treatment to accomplish this standard. In recent years, several researchers have been attempting to discover practical and expendable adsorbents for some water filtration systems that are utilized in many arsenic endemic territories. Metal oxide-based adsorbents had been proved to be the best strategies for arsenic expulsion/removal. This chapter reviews the r…
Assessment of the quality of the air in the city of Palermo through chemical and cell analyses on Pinus Needles
2001
The influence of air pollution on the chemical composition of Pinus sp. needles was examined in polluted and control sites in and around the city of Palermo (Sicily). The chemical composition of needles indicated the extent of contamination of the trees, which were cytologically examined. Cell analysis was carried out on pine samples, including needles and pollens, from 15 different locations. Biostructural and spectrophotometric tests were performed. In particular, concentrations of toxic (Cd, Pb) and non-toxic metals (Fe,Cu, Zn) were determined, as well as injury caused by their accumulation in the needles. The more highly urbanised areas showed higher concentrations of metals (Pb, Cu. Zn…