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

2014 ◽  
Vol 14 (2) ◽  
pp. 1075-1092 ◽  
Author(s):  
S. Sandrini ◽  
L. Giulianelli ◽  
S. Decesari ◽  
S. Fuzzi ◽  
P. Cristofanelli ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Gamma Ray ◽  
Fine Fraction ◽  
Chemical Properties ◽  
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 (Italy) GAW-WMO (Global Atmosphere Watch, World Meteorological Organization) Global Station (2165 m a.s.l.) have allowed the detection of the volcanic aerosol plume resulting from the Eyjafjallajökull (Iceland) eruption of spring 2010. The event affected the Mt. Cimone 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 April 19 to 21 and the second from 18 to 20 May 2010. This paper reports the modification of aerosol characteristics observed during the two episodes, both characterised 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, particle induced X-ray emission–particle induced gamma-ray emission (PIXE–PIGE) and inductively coupled plasma mass spectrometry (ICP-MS)) were performed on aerosols collected by ground-level discrete sampling. The resulting database allows the characterisation 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 characterised 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 light of the huge distance of Mt. Cimone from the source, confirming the widespread diffusion of the Eyjafjallajökull ashes over Europe.

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 Basic Materials Studies of Lanthanide Halide Scintillators

2007 ◽  
Vol 1038 ◽  
Author(s):  
F. P. Doty ◽  
Douglas McGregor ◽  
Mark Harrison ◽  
Kip Findley ◽  
Raulf Polichar ◽  
...  
Keyword(s):  
Gamma Ray ◽  
Materials Science ◽  
Low Cost ◽  
Large Diameter ◽  
Scale Up ◽  
Chemical Properties ◽  
Anisotropic Plasticity ◽  
Ongoing Work ◽  
Perfect Cleavage ◽  
Physical And Chemical

AbstractCerium and lanthanum tribromides and trichlorides form isomorphous alloys with the hexagonal UCl3 type structure, and have been shown to exhibit high luminosity and proportional response, making them attractive alternatives for room temperature gamma ray spectroscopy. However the fundamental physical and chemical properties of this system introduce challenges for material processing, scale-up, and detector fabrication. In particular, low fracture stress and perfect cleavage along prismatic planes cause profuse cracking during and after crystal growth, impeding efforts to scale this system for production of low cost, large diameter spectrometers. We have reported progress on basic materials science of the lanthanide halides. Studies to date have included thermomechanical and thermogravimetric analyses, hygroscopicity, yield strength, and fracture toughness. The observed mechanical properties pose challenging problems for material production and post processing; therefore, understanding mechanical behavior is key to fabricating large single crystals, and engineering of robust detectors and systems. Analysis of the symmetry and crystal structure of this system, including identification of densely-packed and electrically neutral planes with slip and cleavage, and comparison of relative formation and propagation energies for proposed slip systems, suggest possible mechanisms for deformation and crack initiation under stress. The low c/a ratio and low symmetry relative to traditional scintillators indicate limited and highly anisotropic plasticity cause redistribution of residual process stress to cleavage planes, initiating fracture. Ongoing work to develop fracture resistant lanthanide halides is presented.

scholarly journals What Was Released? Assessing the Physical Properties and Chemical Composition of Petroleum and Products of Burned Oil

Oceanography ◽  
2021 ◽  
Vol 34 (1) ◽  
pp. 44-57
Author(s):  
Jürgen Rullkötter ◽  
John Farrington
Keyword(s):  
Oil Spills ◽  
Complex Mixture ◽  
Chemical Properties ◽  
Analytical Techniques ◽  
Ion Cyclotron Resonance ◽  
Model Calculations ◽  
Research Questions ◽  
Physical And Chemical ◽  
And Chemical Properties

The severity of oil spills depends on the quantity of material released and its physical and chemical properties. The total amount of petroleum spilled during the Deepwater Horizon incident and the relative fractions of the chemical compound classes of the Macondo oil were obtained by measurements, observations, and model calculations, with a significant amount of uncertainty. Because petroleum is an extremely complex mixture of many thousands or more of gaseous, liquid, and solid constituents, full elucidation of their compositions at the molecular level is impossible with presently available analytical techniques. This paper reviews published work on widely used analytical techniques and points out that scientists’ varying approaches to research questions and preferences for methods of analysis constitute a source of uncertainty. In addition, the focus is on two technical advancements developed over the last two decades, namely two-dimensional gas chromatography and Fourier transform ion cyclotron resonance mass spectrometry. Both were particularly valuable in the analysis of the spilled Macondo oil and its weathering products. Among the different processes of alteration of the original oil, only in situ oil burning is dealt with in this paper. This review reveals the paucity of data on this mitigation process and shows the need for more systematic coordination of methods in burned oil research studies.

scholarly journals A Review on Characterizations and Biocompatibility of Functionalized Carbon Nanotubes in Drug Delivery Design

2014 ◽  
Vol 2014 ◽  
pp. 1-20 ◽  
Author(s):  
Julia M. Tan ◽  
Palanisamy Arulselvan ◽  
Sharida Fakurazi ◽  
Hairuszah Ithnin ◽  
Mohd Zobir Hussein
Keyword(s):  
Carbon Nanotubes ◽  
Drug Delivery ◽  
Surface Modification ◽  
Chemical Properties ◽  
Analytical Techniques ◽  
Aqueous Environment ◽  
Functionalized Carbon Nanotubes ◽  
Characterization Methods ◽  
Physical And Chemical

The revolutionary development of functionalized carbon nanotubes (f-CNTs) for applications in nanomedicine has emerged as one of the most interesting fields, which has increased exponentially in recent years. This is due to their appealing physical and chemical properties, as well as their unique architecture. After a brief introduction on the physicochemical properties of carbon nanotubes (CNTs), we described several functionalization methods for the surface modification of CNTs, with the aim to facilitate their solubility in physiological aqueous environment. This review focuses on recent advances in drug delivery design based onf-CNTs with an emphasis on the determination of various parameters involved and characterization methods used in order to achieve higher therapeutic efficacy of targeted drug delivery. In particular, we will highlight a variety of different analytical techniques which can be used to characterize the elemental composition, chemical structure, and functional groups introduced onto the CNTs after surface modification. We also review the current progress of availablein vitrobiocompatibility assays based onf-CNTs and then discuss their toxicological profile and biodistribution for advanced drug delivery.

Effect of alpha particle irradiations on the structural properties of graphene oxide

2018 ◽  
Vol 32 (31) ◽  
pp. 1850343 ◽  
Author(s):  
M. F. Eissa ◽  
Waleed M. A. El Rouby
Keyword(s):  
Graphene Oxide ◽  
Alpha Particle ◽  
Gamma Ray ◽  
Fourier Transforms ◽  
Chemical Properties ◽  
Alpha Particles ◽  
Multilayer Graphene ◽  
Irradiation Effect ◽  
Physical And Chemical ◽  
Different Doses

Graphene has been considered one of the most important materials for many applications due to its unique electronic structure, physical and chemical properties. Graphite flakes are the main source of graphene oxide which can be transformed to graphene after reduction. The effect of irradiation on graphene oxide has been rarely studied, only few studies dealing with the irradiation of graphene oxide with gamma radiation were reported. The effect of irradiation of graphene oxide with gamma ray doses (low linear energy transfer) has been previously studied. It was found that there are no changes in the crystalline structure of graphene oxide after irradiation. Graphene oxide was prepared by modified Hummer’s method. The scanning electron microscopy image of the obtained sample suggests the presence of both single and multilayer graphene oxide sheets. The structural measurements for the graphene oxide samples with high linear energy transfers were carried out after irradiations with different doses of alpha particle (9.30–479.90 Gy). The effect of irradiation on oxygen functional groups of graphene oxide was followed by Fourier transforms infra-red spectrometer. Moreover, the irradiation effect on the lamellar space of graphene oxide layers was measured by X-ray diffraction. It was found that the d-spacing of graphene oxide was decreased after alpha particles irradiation with different doses. The effect of irradiation on dielectric constant and conductivity of graphene oxide samples was measured in the frequency range (200 Hz–1.00 MHz). The dielectric measurements show less dependence on irradiation doses. The graphene oxide sample can be used as radiation dosimeter for [Formula: see text]-particles in the range of the low irradiation doses.

scholarly journals Seasonal Variation, Chemical Composition, and PMF-Derived Sources Identification of Traffic-Related PM1, PM2.5, and PM2.5–10 in the Air Quality Management Region of Žilina, Slovakia

2021 ◽  
Vol 18 (19) ◽  
pp. 10191
Author(s):  
Dusan Jandacka ◽  
Daniela Durcanska
Keyword(s):  
Seasonal Variation ◽  
Urban Environment ◽  
Maximum Concentration ◽  
Inductively Coupled Plasma ◽  
Road Traffic ◽  
Fine Fraction ◽  
Gravimetric Method ◽  
Principal Component ◽  
Coarse Fraction ◽  
Over Time

Particulate matter (PM) air pollution in the urban environment is mainly related to the presence of potential sources throughout the year. Road transport is one of the most important sources of PM in the urban environment, because it directly affects pedestrians. PM measurements were performed in the city of Žilina, Slovakia, at various road-traffic-related measurement stations over the course of several years. This paper evaluates changes in the concentration of the fine fraction (PM2.5), the ultrafine fraction (PM1), and the coarse fraction (PM2.5–10) over time. PM concentrations were measured by reference gravimetric method. Significant changes in PM concentrations over time due to the diversification of pollution sources and other, secondary factors can be observed from the analysis of the measured data. PM samples were subjected to chemical analysis inductively coupled plasma mass spectrometry (ICP-MS) to determine the concentrations of elements (Mg, Al, Ca, Cr, Cu, Fe, Cd, Sb, Ba, Pb, Ni, and Zn). The seasonal variation of elements was evaluated, and the sources of PM2.5, PM1, and PM2.5–10 were estimated using principal component analysis (PCA) and positive matrix factorization (PMF). PM2.5 (maximum concentration of 148.95 µg/m3 over 24 h) and PM1 (maximum concentration of 110.51 µg/m3 over 24 h) showed the highest concentrations during the heating season, together with the elements Cd, Pb, and Zn, which showed a significant presence in these fractions. On the other hand, PM2.5–10 (maximum concentration of 38.17 µg/m3 over 24 h) was significantly related to the elements Cu, Sb, Ba, Ca, Cr, Fe, Mg, and Al. High correlation coefficients (r ≥ 0.8) were found for the elements Mg, Ca, Fe, Al, Cd, Pb, and Zn in the PM1 fraction, Cd, Pb, and Zn in PM2.5, and Ba, Sb, Fe, Cu, Cr, Mg, Al, and Ca in PM2.5–10. Using PMF analysis, three major sources of PM (abrasion from tires and brakes, road dust resuspension/winter salting, and combustion processes) were identified for the PM2.5 and PM1 fractions, as well as for the coarse PM2.5–10 fraction. This study reveals the importance of non-exhaust PM emissions in the urban environment.

scholarly journals Monitoring of the Physical and Chemical Properties of a Gasoline Engine Oil during Its Usage

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Behnam Rahimi ◽  
Abolfazl Semnani ◽  
Alireza Nezamzadeh-Ejhieh ◽  
Hamid Shakoori Langeroodi ◽  
Massoud Hakim Davood
Keyword(s):  
Physical Properties ◽  
Inductively Coupled Plasma ◽  
Gasoline Engine ◽  
Viscosity Index ◽  
Chemical Properties ◽  
Engine Oil ◽  
Physical And Chemical Properties ◽  
Total Acid ◽  
Physical And Chemical ◽  
And Chemical Properties

Physicochemical properties of a mineral-based gasoline engine oil have been monitored at 0, 500, 1000, 2000, 3500, 6000, 8500, and 11500 kilometer of operation. Tracing has been performed by inductively coupled plasma and some other techniques. At each series of measurements, the concentrations of twenty four elements as well as physical properties such as: viscosity at 40 and 100°C; viscosity index; flash point; pour point; specific gravity; color; total acid and base numbers; water content have been determined. The results are indicative of the decreasing trend in concentration of additive elements and increasing in concentration for wear elements. Different trends have been observed for various physical properties. The possible reasons for variations in physical and chemical properties have been discussed.

scholarly journals Development of the Functionalized Nanocomposite Materials for Adsorption/Decontamination of Radioactive Pollutants

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2896
Author(s):  
Gyo Eun Gu ◽  
Joonwon Bae ◽  
Ho Seok Park ◽  
Jin-Yong Hong
Keyword(s):  
Chemical Properties ◽  
Analytical Techniques ◽  
Electrospun Nanofibers ◽  
High Specific Surface Area ◽  
High Porosity ◽  
Adsorption Sites ◽  
Electrospinning Method ◽  
One Step ◽  
Cyano Groups ◽  
Physical And Chemical

A polymer-based nanofiber membrane with a high specific surface area, high porosity and abundant adsorption sites is demonstrated for selective trapping of radionuclides. The Prussian blue (PB)/poly(methyl methacrylate) (PMMA) nanofiber composites were successfully prepared through a one-step, single-nozzle electrospinning method. Various analytical techniques were used to examine the physical and chemical properties of PB nanoparticles and electrospun nanofibers. It is possible to enhance binding affinity and selectivity to radionuclide targets by incorporation of the PB nanoparticles into the polymer matrix. It is noteworthy that the maximum 133Cs adsorption capacity of hte PB/PMMA nanofiber filter is approximately 28 times higher than that of bulk PB, and the removal efficiency is measured to be 95% at 1 ppm of 133Cs. In addition, adsorption kinetics shows that the PB/PMMA nanofiber has a homogenous surface for adsorption, and all sites on the surface have equal adsorption energies in terms of ion-exchange between cyano groups of the introduced PB nanoparticles and radionuclides.

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