Search results for "particulate"

Aerosol responses to precipitation along North American air trajectories arriving at Bermuda

2021

North American pollution outflow is ubiquitous over the western North Atlantic Ocean, especially in winter, making this location a suitable natural laboratory for investigating the impact of precipitation on aerosol particles along air mass trajectories. We take advantage of observational data collected at Bermuda to seasonally assess the sensitivity of aerosol mass concentrations and volume size distributions to accumulated precipitation along trajectories (APT). The mass concentration of particulate matter with aerodynamic diameter less than 2.5 µm normalized by the enhancement of carbon monoxide above background (PM2.5/ΔCO) at Bermuda was used to estimate the degree of aerosol loss durin…

Composition and diurnal variability of the natural Amazonian aerosol

2003

As part of the Large-Scale Biosphere-Atmosphere Experiment in Amazonia (LBA)-Cooperative LBA Airborne Regional Experiment (CLAIRE) 2001 campaign, separate day and nighttime aerosol samples were collected in July 2001 at a ground-based site in Amazonia, Brazil, in order to examine the composition and temporal variability of the natural “background” aerosol. A combination of analytical techniques was used to characterize the elemental and ionic composition of the aerosol. Major particle types larger than ∼0.5 μm were identified by electron and light microscopy. Both the coarse and fine aerosol were found to consist primarily of organic matter (∼70 and 80% by mass, respectively), with the coar…

Cooking Particulate Matter: A Systematic Review on Nanoparticle Exposure in the Indoor Cooking Environment

2022

Background: Cooking and fuel combustion in the indoor environment are major sources of respirable suspended particulate matter (RSPM), which is an excellent carrier of potentially harmful absorbed inorganic and organic compounds. Chronic exposure to RSPM can lead to acute pulmonary illness, asthma, cardiovascular disease, and lung cancer in people involved in cooking. Despite this, questions remain about the harmfulness of different particulate matter (PM) sources generated during cooking, and the factors influencing PM physico-chemical properties. The most reliable methods for sampling and analyzing cooking emissions remain only partially understood. Objectives: This review aims to compreh…

Organosulfates in atmospheric aerosol: synthesis and quantitative analysis of pm<sub>2.5</sub> from xi'an, northwestern c…

2018

Abstract. The sources, formation mechanism and amount of organosulfates (OS) in atmospheric aerosol are not yet well understood, partly due to the lack of authentic standards for quantification. In this study, we report an improved robust procedure for the synthesis of organosulfates with different functional groups. Nine authentic organosulfate standards were synthesized and four standards (benzyl sulfate, phenyl sulfate, glycolic acid sulfate, and hydroxyacetone sulfate) were used to quantify their ambient concentrations. The authentic standards and ambient aerosol samples were analyzed using an optimized ultra performance liquid chromatography–electrospray ionization-tandem mass spectrom…

RADIONUCLIDE CONCENTRATIONS IN AIR PARTICULATE AT PALERMO (ITALY) FOLLOWING FUKUSHIMA ACCIDENT

2012

Following the Fukushima accident, a series of samplings were carried out with a daily frequency to detect the arrival of radioactive contamination in air at Palermo (Italy) and to follow its evolution during the time. Air particulate collection was performed by suction of atmospheric air through cellulose filter paper by means of a high-volume air sampler (∼15 000 m(3) d(-1)). Spectrometric analysis of the filters highlights the presence of (131)I, (134)Cs, (137)Cs and, only for a few samples, traces of (132)Te-(132)I and (136)Cs. Maximum airborne concentrations were 883 μBq m(-3) for (131)I (only particulate), 81 μBq m(-3) for (137)Cs and 70 μBq m(-3) for (134)Cs. From a dose to population…

Dynamics of particulate major and trace elements in the lower reaches of the Daugava River and adjacent area of the Gulf of Riga (Baltic Sea).

2004

Suspended particulate matter (SPM) was collected in the freshwater-seawater mixing zone in the lower reaches of the Daugava River (Latvia) and adjacent marine area, during five cruises in 1998-2001. The study focused on biogeochemical phase exchange processes. SPM in the freshwater was found to be mainly allochthonous with a high content of organic matter, Mn and sorbed phosphate. Property-salinity plots suggested flocculation of humic-Fe complexes across the salinity gradient. The variability of sorbed phosphate was related to particulate Fe, although no dependence on pH and ionic strength was observed. The Mn contents of SPM mainly follow conservative mixing, but there are also indication…

Seasonal benthic nepheloid layer in the Gulf of Riga, Baltic Sea: Sources, structure and geochemical interactions

2005

Abstract The sources of particles, as well as the geochemical structure and interfacial exchange were studied for the summer benthic nepheloid layer of the shallow (50 m) Gulf of Riga. The material was sampled at nine stations during three cruises of August 2001–2003 with a main focus on the deep waters. Suspended particulate matter (SPM) and its major (N, Si, P, Al, Fe, Mn, Ca) elements were determined as the principal parameters. The results indicate the summer benthic nepheloid layer as an important component of the environmental regime of the Gulf of Riga. The nepheloid layer develops as a result of the near-bottom hydrodynamics and a corresponding saline structure below the thermocline…

PREPARATION AND CHARACTERIZATION OF BIOPOLYMERIC POROUS STRUCTURES FOR ADVANCED APPLICATIONS

Porous biopolymers received an increasing academic and industrial interest finding application in several fields such as tissue engineering, bioprocess intensification and waste removal. Tissue engineering combines the knowledge of materials science and bioengineering in order to develop structures able to substitute and restore the normal function of injured or diseased tissues. In this context, polymeric 3D or 2D scaffolds are widely investigated as temporary cell guidance during the tissue restore. Porous biomaterials can offer a versatile and cost effective way for immobilization of filamentous microorganisms in submerged fermentation processes for the production of biologically active …

Hyaluronic Acid–Silica Nanohybrid Gels

2013

Excessive water sorption and low mechanical properties are a severe drawback in some biomedical applications of hyaluronic acid (HA). A way to improve these properties is here explored through the novel concept of nanohybrid hydrogels consisting of a HA matrix including different amounts of silica-derived species. This inorganic filler phase controls the mechanical and swelling properties of HA cross-linked matrices. Below a 2 wt % of silica in the systems, nanoparticle aggregates of tens of nanometers and silica oligomers are distributed more or less homogeneously throughout the organic matrix, without percolating. This morphology of the silica phase is accompanied by an increased swelling…

Quantitative x-ray diffraction phase analysis of coarse airborne particulate collected by cascade impactor sampling

1997

Mineralogical composition of Castellon (Spanish Mediterranean coast) atmospheric aerosol was studied by X-ray diffraction by sampling with a cascade impactor without filters. Quantitative phase analysis of natural phases present in the atmospheric coarse aerosol was performed using a modified version of the computer program MENGE, that uses the standardless X-ray method developed by Rius for the quantitative analysis of multiphase mixtures, adapted for PC running. Presence of quartz, calcite and gypsum was identified in the atmospheric aerosol and we have quantified their amounts using the standardless method.