Search results for "SULFUR"
showing 10 items of 545 documents
Agronomic treatments to avoid seed presence in ‘Nadorcott’ mandarin I. Effect on in vivo pollen tube growth
2022
Abstract Fresh market demands high quality fruit and, therefore, citrus growers and researchers are constantly looking for solutions to avoid seed presence. Current horticultural techniques have low effectiveness or high cost. The objective of this study is to evaluate the inhibition effect of seven products on the in vivo pollen tube growth in Nadorcott mandarin, which is a high-value seedy variety. To achieve this main objective, three inorganic fertilizers (ammonium nitrate, potassium nitrate, sulfur), and four saccharides (saccharose, methyl cellulose, callose, chitosan) were applied to Nadorcott stigmas 24 h before and after hand pollination. Pollen tubes were counted 1, 3, and 5 days …
A Theoretical Study of the Wet Removal of Atmospheric Pollutants. Part II: The Uptake and Redistribution Of (NH4)2SO4Particles and SO2Gas Simultaneou…
1987
Abstract A theoretical model has been formulated which allows the processes which control the wet deposition of atmospheric aerosol particles and pollutant gases to be included in cloud dynamic models. The cloud considered in the model was allowed to grow by condensation and collision–coalescence, to remove aerosol particles by nucleation and impaction scavenging, and to remove pollutant gases by convective diffusion. The model was tested by using a simple air-parcel model as the dynamic framework. In this form the model was used to determine the fate of ammonium sulfate [(NH4)2SO4] particles and sulfur dioxide (SO2) gas as they became scavenged by cloud and precipitation drops. Special emp…
The combined effect of CO2, ozone, and drought on the radical scavenging system of young oak trees (Quercus petraea) — A phytothron study
1998
In order to study the combined effects of CO 2 , ozone, and drought, we simulated in a controlled environment the climatic conditions of a German oak stand with high ozone (daytime: 80 ppb, control: 20 ppb) during one vegetative period under a regime of low and high CO 2 concentration (370 vs 720 ppm) and drought (4 weeks < -800 hPa). To investigate the effects of CO 2 , ozone and drought on the radical scavenging system, we monitored the level of glutathione, ascorbate, and α-tocopherol. However, it is important that, under the regime of elevated CO 2 , the antioxidative behaviour of glutathione and ascorbate appears to be masked by their function as storage molecules for sulfur or carbon.
Urban air pollution and emergency room admissions for respiratory symptoms: a case-crossover study in Palermo, Italy
2011
Abstract Background Air pollution from vehicular traffic has been associated with respiratory diseases. In Palermo, the largest metropolitan area in Sicily, urban air pollution is mainly addressed to traffic-related pollution because of lack of industrial settlements, and the presence of a temperate climate that contribute to the limited use of domestic heating plants. This study aimed to investigate the association between traffic-related air pollution and emergency room admissions for acute respiratory symptoms. Methods From January 2004 through December 2007, air pollutant concentrations and emergency room visits were collected for a case-crossover study conducted in Palermo, Sicily. Ris…
PCDTs in the environment
1997
Abstract Polychlorinated dibenzothiophenes (PCDTs) are sulfur analogues of polychlorinated dibenzofurans. Recently, PCDTs have been found in stack gas and fly ash samples, pulp mill effluents, sediments and in some aquatic organisms. PCDTs have been analyzed by high resolution GC/MS and by other GC-MS techniques. Combustion is until now the major known source of PCDTs in the environment. Tri-, tetra- and pentaCDTs in concentrations approaching those of PCDTs have been analyzed in some samples from waste incineration and metal reclamation. Concentrations of PCDTs in pulp mill effluents have been found to be quite low. 2378-TeCDT was found to be the major TeCDT isomer in some pulp mill efflue…
Assessing anthropogenic pressures on coastal marine ecosystems using stable CNS isotopes: State of the art, knowledge gaps, and community-scale persp…
2015
Abstract In recent decades, the analysis of carbon, nitrogen and sulfur stable isotopes (SIA) has emerged as a powerful, viable methodology for examining food web structure and dynamics, as well as addressing a number of applied issues. Here, we provide a state-of-the-art review of the use of SIA for assessing anthropogenic pressures on natural ecosystems, in order to establish current knowledge gaps and identify promising applications for evaluating the ecological status of marine coastal waters. Specifically, the potential of SIA to provide food web-scale indicators for estimating cumulative anthropogenic pressures is addressed. The review indicates that the methodology has been used for …
Lichens <i>(Xanthoria parietina)</i> - Bio-Indicators for Sulphur and Metallic Elements for Pollution Investigation in Riga City
2021
The aim of the research was to investigate the pollution level of sulphur and metallic elements in Riga city (Freeport of Riga, Kundziņsala, Mežaparks) by using foliose lichens (Xanthoriaparietina) as a bio-indicators. Obtained results show that the Freeport of Riga is the most polluted area comparing with other neatest places in Riga city, Kundziņsala and Mežaparks. Evaluate a washing effect, obtained results shows that lichen thallus contains about 50 % of total amount of sulphur and investigated elements as dust particles on the surface of lichens.
Sulfur’s role in the flame retardancy of thio-ether–linked hyperbranched polyphosphoesters in epoxy resins
2020
Abstract Hyperbranched polyphosphoesters are promising multifunctional flame retardants for epoxy resins. These polymers were prepared via thiol-ene polyaddition reactions. While key chemical transformations and modes of actions were elucidated, the role of sulfur in the chemical composition remains an open question. In this study, the FR-performance of a series of phosphorus-based flame retardant additives with and without sulfur (thio-ethers or sulfones) in their structure are compared. The successful synthesis of thio-ether or sulfone-containing variants is described and verified by 1H and 31P NMR, also FTIR and MALDI-TOF. A decomposition process is proposed from pyrolytic evolved gas an…
Sulphur dioxide evolution during dried apricot storage
2009
Abstract Sulphur dioxide is used as a pre-treatment to facilitate drying, improve product quality and extend the shelf life of apricots. During storage, SO 2 losses are observed, thus reducing the effect of this agent. The aim of this paper is to analyze the evolution of SO 2 content in dried apricots packaged in different types of containers, namely glass and polypropylene trays thermosealed with different films (oriented polyamide OPA + polyethylene PE and polyamide PA + polypropylene PP). The packaging atmosphere was air in all cases. Storage was carried out at constant temperature: 5, 15, 25 and 35 °C. Stored samples were analysed periodically over 12 months. In order to model the SO 2 …
Diversity of freshwater Epsilonproteobacteria and dark inorganic carbon fixation in the sulphidic redoxcline of a meromictic karstic lake.
2015
Sulfidic redoxclines are a suitable niche for the growth and activity of different chemo- and photolithotrophic sulphide-oxidizing microbial groups such as the Epsilonproteobacteria and the green sulfur bacteria (GSB). We have investigated the diversity, abundance and contribution to inorganic carbon uptake of Epsilonproteobacteria in a meromictic basin of Lake Banyoles. CARD-FISH counts revealed that Epsilonproteobacteria were prevalent at the redoxcline in winter (maximum abundance of 2 × 10(6) cells mL(-1), ≈60% of total cells) but they were nearly absent in summer, when GSB bloomed. This seasonal trend was supported by 16S rRNA gene pyrotag datasets, which revealed that the epsilonprote…