scholarly journals Complex Characterization of Fine Fraction and Source Contribution to PM2.5 Mass at an Urban Area in Central Europe

Atmosphere ◽  
2020 ◽  
Vol 11 (10) ◽  
pp. 1085
Author(s):  
Lucyna Samek ◽  
Anna Turek-Fijak ◽  
Alicja Skiba ◽  
Przemyslaw Furman ◽  
Katarzyna Styszko ◽  
...  
Keyword(s):  
Fine Particles ◽  
Chemical Constituents ◽  
Fine Fraction ◽  
Urban Site ◽  
Particulate Pollution ◽  
Input Dataset ◽  
Physical And Chemical ◽  
The City ◽  
Careful Comparison

It is well documented that Southern Poland is one of the most polluted areas in Europe due to the highest airborne concentrations of particulate matter (PM). Concentrations of fine particles are especially high in winter. Apart from detailed number concentrations, it is essential to accurately identify and quantify specific particulate pollution sources. Only a few Polish research centers are involved in such experiments—among them is Krakow research group. For the most part, research focuses on collecting 24-h average samples from stationary PM samplers at ambient monitoring sites and quantifying the specific elements and chemical constituents in PM. This approach includes modeling methods that can use the variability in physical and chemical PM characteristics as an input dataset to identify possible sources of the particles. The objective of this paper is to provide research results based on data collected from June 2018 to May 2019 from a single monitoring station at a central urban site. Careful comparison of data obtained prior to a 2019 law prohibiting solid fuel burning in the city of Krakow with data (2019–2020) when a regulation went into effect should indicate progress by noting lower PM levels. This work has shown that the method applied and Krakow results might be of interest to the broader community in regions of high PM concentration.

Characterization of “Stickies” Polymeric Contaminants in Recycle Pulp Slurries by Optical Fluorescence and Scanning Electron Microscopy.

1997 ◽  
Vol 3 (S2) ◽  
pp. 1247-1248
Author(s):  
R. M. Fisher ◽  
J. Holbery ◽  
Barbara Reine
Keyword(s):  
Electron Microscopy ◽  
Fine Particles ◽  
Polymeric Materials ◽  
Measuring Instruments ◽  
Paper Machine ◽  
X Ray ◽  
Optical Fluorescence ◽  
Thermal Analysis Techniques ◽  
Physical And Chemical

A major problem now hampering increased recycling of old cardboard containers (OCC), is the presence of significant amounts of polymeric materials such as adhesives, tapes, labels and wax which enter the pulp process stream along with the cardboard and paper that was collected for recycling. Many of these materials contain very fine particles of inorganic fillers and pigments. These various contaminant constituents combine in some, as yet unknown, manner to form an extremely gummy material that deposits on paper machine surfaces and sticks tenaciously (hence the term “Stickies”). The sticky blobs are very difficult to remove and increases machine downtime and maintenance costs as well as causing blemishes on the finished container board product Light optical image analysis, UV fluorescence, FTIR and electron microscopy are being used in consort with particle size measuring instruments, TGS and DSC thermal analysis techniques, FTIR infra-red spectroscopy as well as XRF (x-ray fluorescence spectroscopy ), XPS (x-ray photo emission spectroscopy) and classical contact angle determination methods as part of a broad program to characterize the physical and chemical nature of stickies in pulp slurries with the goal of removing them or alleviating their pronounced tendency to deposit on machinery and paper products.

Chemical Constituents Study of Weixian Turnip (Raphanus sativus L.)

2014 ◽  
Vol 941-944 ◽  
pp. 1036-1039
Author(s):  
Gui Feng Li ◽  
Li Gang Deng ◽  
Hong Zhang ◽  
Ping Juan Zhao ◽  
Hui Wang ◽  
...  
Keyword(s):  
Raphanus Sativus ◽  
Chemical Constituents ◽  
Chemical Properties ◽  
Biologically Active ◽  
Isolation And Characterization ◽  
Raphanus Sativus L ◽  
Physical And Chemical ◽  
First Time ◽  
Active Effects

Objective: Cruciferous herb plant Weixian Radish (Raphanus Sativus L.), also known as Lai Fu, is a kind of popularly eatable fruit and vegetable. The present paper describes the isolation and characterization of two compounds isolated from Weixian Radish. Methods: The methanol extraction was separated by column chromatography. Obtained compounds were identified with physical and chemical properties and NMR. Results: Two compounds were isolated from the extract of Raphanus Sativus L. for the first time and their structures were identified as β-sitosterol and 1-O-(β-D-glucopyranosyl)-(2S, 3S, 4R, 8E)-2-[(2'R)-2'-hydroxyltetracos-15'-enoylamino]-8-octa-decene-1, 3, 4-triol, which have many biologically active effects.

scholarly journals In-situ physical and chemical characterization of the Eyjafjallajökull aerosol plume in the free troposphere over Italy

2013 ◽  
Vol 13 (8) ◽  
pp. 20195-20238
Author(s):  
S. Sandrini ◽  
L. Giulianelli ◽  
S. Decesari ◽  
M. C. Facchini ◽  
S. Fuzzi ◽  
...  
Keyword(s):  
Fine Fraction ◽  
Chemical Properties ◽  
Chemical Characterization ◽  
Analytical Techniques ◽  
Ground Level ◽  
Coarse Fraction ◽  
Volcanic Plume ◽  
Physical And Chemical ◽  
Aerosol Plume

Abstract. Continuous measurements of physical and chemical properties at the Mt. Cimone GAW-WMO Global Station (2165 m a.s.l.) allowed the detection of the volcanic aerosol plume resulting from the Eyjafjallajökull eruption of spring 2010. The event affected the site after a transport over a distance of more than 3000 km. Two main transport episodes were detected during the eruption period, showing a volcanic fingerprint discernible against the free tropospheric background conditions typical of the site, the first from 19 to 21 April and the second from 18 to 20 May 2010. The paper reports the modification of aerosol characteristics observed during the two episodes, both characterized by an abrupt increase in fine and, especially, coarse mode particle number. Analysis of major, minor and trace elements by different analytical techniques (Ionic Chromatography, PIXE-PIGE and ICP-MS) were performed on aerosols collected by ground level discrete sampling. The resulting database allows the characterization of aerosol chemical composition during the volcanic plume transport and in background conditions. During the passage of the volcanic plume, the fine fraction was dominated by sulphates, denoting the secondary origin of this mode, mainly resulting from in-plume oxidation of volcanic SO2. By contrast, the coarse fraction was characterized by increased concentration of numerous elements of crustal origin, such as Fe, Ti, Mn, Ca, Na, and Mg, which enter the composition of silicate minerals. Data analysis of selected elements (Ti, Al, Fe, Mn) allowed the estimation of the volcanic plume's contribution to total PM10, resulting in a local enhancement of up to 9.5 μg m-3, i.e. 40% of total PM10, on 18 May, which was the most intense of the two episodes. These results appear significant, especially in the light of the huge distance of Mt. Cimone from the source, confirming the widespread diffusion of the Eyjafjallajokull ashes over Europe.

scholarly journals Evaluation of hydromechanical behavior and macro-structure of an expansive soil in the city of Paulista-PE Brazil

2021 ◽  
Vol 337 ◽  
pp. 01002
Author(s):  
Felipe Araújo Silva Barbosa ◽  
Arthur Gomes Dantas de Araújo ◽  
Thalita Cristina Rodrigues Silva ◽  
Izabela Medeiros de Lima Bezerra ◽  
Antonio Celso Dantas Antonino ◽  
...  
Keyword(s):  
Expansive Soils ◽  
Expansive Soil ◽  
Chemical Characterization ◽  
Liquid Limit ◽  
Before And After ◽  
X Ray Computed ◽  
Wetting Process ◽  
Physical And Chemical ◽  
The City

The characterization of the structural arrangement of an unsaturated soil is important for the understanding of its behavior. For expansive soils, obtaining this information and combining it with an understanding of their intrinsic and extrinsic properties, makes it possible to predict their performance. The experimental procedure for this study was developed using the expansive soil of the Maria Farinha formation in the city of Paulista, in Pernambuco, Brazil. Physical and chemical characterization tests, edometric tests with wetting, and structural analysis through X-Ray computed tomography were performed for both undisturbed and compacted samples, before and after wetting and swelling. The compaction process was performed without any prior air drying and without loosening, beginning with the field moisture level. Based on its liquid limit and plasticity index, the soil can be classified as CH according to the USCS, moderately acidic, with a swelling potential ranging from high to very high, depending on the initial suction of the sample. The analysis of the soil macro-structure revealed a smaller number of voids in the compacted samples. In addition, it was found that the wetting process caused a reduction of the soil macro pores, in both cases.

Characterization of Different Brazilian Soils for the Production of Ceramic Artifacts

2021 ◽  
Vol 1017 ◽  
pp. 123-132
Author(s):  
A.R.G. Azevedo ◽  
S.V. Klyuev ◽  
V.A. Klimenko ◽  
M.T. Marvila ◽  
Roman Fediuk
Keyword(s):  
Ceramic Materials ◽  
Raw Material ◽  
Technological Parameters ◽  
Ceramic Blocks ◽  
Physical And Chemical ◽  
Existing Housing ◽  
The City ◽  
Production Industry ◽  
Different Soils

The ceramic materials production industry produces a wide variety of products, such as sealing blocks, roof tiles and shackles, used in civil construction. However, one of the major problems related to the production of these artefacts is the large consumption of natural raw material, which are the clays that are calcined and acquire appropriate technological properties. Brazil is a country that has great prominence in the production of ceramic blocks, used to reduce the existing housing deficit, however the great variability in the characteristics of the soils in the country makes this process very difficult. Thus, the objective of this work was to evaluate the physical and chemical characteristics of four different soils collected in deposits in the city of Campos dos Goytacazes, evaluating right after its technological parameters such as the flexural mechanical strength, water absorption and linear burning retraction of the calcined prismatic specimens at 750, 850 and 1100 °C. The results showed that the collected soils have adequate characteristics for the production of ceramic blocks at a temperature of 1100 °C.

scholarly journals Dinâmica Fluvial e Caracterização Limnológica do Córrego do Cedro, Presidente Prudente -São Paulo/ Brasil

2020 ◽  
Vol 13 (4) ◽  
pp. 1851
Author(s):  
Edmiler José Silva Degrande ◽  
Glauber Verner Firmino ◽  
Marco Aurélio Neri Torres
Keyword(s):  
Water Resources ◽  
Cross Sections ◽  
Hydraulic Geometry ◽  
River Dynamics ◽  
Adverse Impacts ◽  
Fluvial Dynamics ◽  
Lotic Environment ◽  
Physical And Chemical ◽  
The City

A necessidade de estudos sobre as questões ambientais, tais como os recursos hídricos, são cada vez mais essenciais como forma de mitigar os impactos adversos promovidos pelas ações antrópicas.  Neste sentido o presente artigo visa analisar a dinâmica fluvial e sua relação com as características limnológicas do córrego do Cedro localizado no município de Presidente Prudente- SP. Para tanto, este estudo avaliou três seções transversais situadas no alto, médio e baixo curso deste ambiente lótico, sendo realizadas coletas em campo de amostras dos principais parâmetros associados a geometria hidráulica do canal como: vazão (Q), largura (w), profundidade (d), e velocidade (v). Para a caracterização limnológica do córrego em questão coletou-se informações sobre o Potencial Hidrogeniônico (pH), com o auxílio de um pHmetro, e a Turbidez (para a qual se utilizou um turbidímetro) e ainda a coleta de sedimentos em suspensão e de leito. A avaliação da carga detrítica em suspensão e de fundo ocorreram no Laboratório de Geologia, Geomorfologia e Recursos Hídricos da Universidade Estadual Paulista (UNESP) campus de Presidente Prudente- SP. Os resultados obtidos demonstram que tanto a dinâmica fluvial quanto as variáveis limnológicas analisadas vêm sofrendo com as formas de uso da terra na bacia repercutindo na entrada de material alóctone de origem tecnogênica, promovendo mudanças no ajuste do sistema fluvial e alterações na característica física e química da água. Dessa forma o estudo tem se mostrado eficaz na correlação entre os dados de geometria hidráulica e limnologia na avaliação ambiental da área em questão.  Fluvial Dynamics and Limnological Characterization of Cedro Stream, President Prudente-SP A B S T R A C TThe need for studies on environmental issues, such as water resources, is increasingly essential as a way of mitigating the adverse impacts caused by human actions. In this sense this article aims to analyze the river dynamics and its relationship with the limnological characteristics of the Cedro stream located in the city of Presidente Prudente-SP. For this, this study evaluated three cross sections located in the high, medium and low course of this lotic environment. Samples were collected in the field of the main parameters associated with the channel hydraulic geometry, such as flow (Q), width (w), depth. (d), and velocity (v). For the limnological characterization of the stream in question we collected information about the Hydrogenionic Potential (pH), with the aid of a pH meter, and the Turbidity (for which a turbidimeter was used), as well as the collection of suspended sediment and bed. The evaluation of the suspended and bottom detrimental load occurred at the Laboratory of Geology, Geomorphology and Water Resources of the Universidade Estadual Paulista (UNESP), Presidente Prudente-SP campus. The results show that both the river dynamics and the limnological variables analyzed have been suffering from land use in the basin, resulting in the entry of allochthonous material of technogenic origin, promoting changes in the fluvial system adjustment and changes in the physical and chemical characteristics of the water. Thus, the study has been shown to be effective in correlating the data of hydraulic geometry and limnology in the environmental assessment of the area in question.Keywords: Hydraulic geometry. Limnology. Environmental diagnosis

Characterization of defects in tabular silver halide grains

1990 ◽  
Vol 48 (4) ◽  
pp. 1046-1047
Author(s):  
C. Goessens ◽  
D. Schryvers ◽  
J. Van Landuyt ◽  
A. Verbeeck ◽  
R. De Keyzer
Keyword(s):  
Radiation Damage ◽  
Silver Halide ◽  
Chemical Characteristics ◽  
X Ray ◽  
Free Region ◽  
Central Defect ◽  
Crystallographic Defects ◽  
Physical And Chemical ◽  
Two Sides

Silver halide grains (AgX, X=Cl,Br,I) are commonly recognized as important entities in photographic applications. Depending on the preparation specifications one can grow cubic, octahedral, tabular a.o. morphologies, each with its own physical and chemical characteristics. In the present study crystallographic defects introduced by the mixing of 5-20% iodide in a growing AgBr tabular grain are investigated. X-ray diffractometry reveals the existence of a homogeneous Ag(Br1-xIx) region, expected to be formed around the AgBr kernel. In fig. 1 a two-beam BF image, taken at T≈100 K to diminish radiation damage, of a triangular tabular grain is presented, clearly showing defect contrast fringes along four of the six directions; the remaining two sides show similar contrast under relevant diffraction conditions. The width of the central defect free region corresponds with the pure AgBr kernel grown before the mixing with I. The thickness of a given grain lies between 0.15 and 0.3 μm: as indicated in fig. 2 triangular (resp. hexagonal) grains exhibit an uneven (resp. even) number of twin interfaces (i.e., between + and - twin variants) parallel with the (111) surfaces. The thickness of the grains and the existence of the twin variants was confirmed from CTEM images of perpendicular cuts.

Chemical Constituents and Antibacterial Activity of Cissus Aralioides.

2020 ◽  
Vol 17 ◽  
Author(s):  
Balogun Olaoye Solomon ◽  
Ajayi Olukayode Solomon ◽  
Owolabi Temitayo Abidemi ◽  
Oladimeji Abdulkarbir Oladele ◽  
Liu Zhiqiang
Keyword(s):  
Plant Extract ◽  
Chemical Constituents ◽  
Ethyl Acetate Fraction ◽  
Antibacterial Activities ◽  
Sub Saharan Africa ◽  
Chromatographic Purification ◽  
Whole Plant ◽  
Sub Saharan ◽  
First Time

: Cissus aralioides is a medicinal plant used in sub-Saharan Africa for treatment of infectious diseases; however the chemical constituents of the plant have not been investigated. Thus, in this study, attempt was made at identifying predominant phytochemical constituents of the plant through chromatographic purification and silylation of the plant extract, and subsequent characterization using spectroscopic and GC-MS techniques. The minimum inhibitory concentration (MICs) for the antibacterial activities of the plant extract, chromatographic fractions and isolated compounds were also examined. Chromatographic purification of the ethyl acetate fraction from the whole plant afforded three compounds: β-sitosterol (1), stigmasterol (2) and friedelin (3). The phytosterols (1 and 2) were obtained together as a mixture. The GC-MS analysis of silylated extract indicated alcohols, fatty acids and sugars as predominant classes, with composition of 24.62, 36.90 and 26.52% respectively. Results of MICs indicated that friedelin and other chromatographic fractions had values (0.0626-1.0 mg/mL) comparable with the standard antibiotics used. Characterization of natural products from C. aralioides is being reported for the first time in this study.

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