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Articles 1 - 18 of 18
Full-Text Articles in Nanoscience and Nanotechnology
Monitoring Exposure To Airborne Ultrafine Particles In Lisbon, Portugal, João F. Gomes
Monitoring Exposure To Airborne Ultrafine Particles In Lisbon, Portugal, João F. Gomes
João F Gomes
No abstract provided.
Assessment Of Exposure To Airborne Ultrafine Particles In The Urban Environment Of Lisbon, Portugal, João F. Gomes
Assessment Of Exposure To Airborne Ultrafine Particles In The Urban Environment Of Lisbon, Portugal, João F. Gomes
João F Gomes
The aim of this study was the assessment of exposure to ultrafine in the urban environment of Lisbon, Portugal, due to automobile traffic, and consisted of the determination of deposited alveolar surface area in an avenue leading to the town center during late spring. This study revealed differentiated patterns for weekdays and weekends, which could be related with the fluxes of automobile traffic. During a typical week, ultrafine particles alveolar deposited surface area varied between 35.0 and 89.2 mm2/cm3, which is comparable with levels reported for other towns such in Germany and the United States. These measurements were also complemented …
Emissions Of Polyciclic Aromatic Hidrocarbons And Polyciclic Carbonyl Bifenils From Electric Arc Furnaces, João F. Gomes
Emissions Of Polyciclic Aromatic Hidrocarbons And Polyciclic Carbonyl Bifenils From Electric Arc Furnaces, João F. Gomes
João F Gomes
This paper describes work done in order to determine the emissions of highly toxic organic micropollutants from electric arc furnaces used in the production of carbon steel from scrap. The study will be allowing to derive relationships between the levels of airborne micropollutants and the operational parameters of the production process so that an abatement of pollution could be achieved. By using the European standard method CEN 1948 for dioxin like compounds sampling and measurement, it was possible to determine the characteristic fingerprint of micropollutants such as polycyclic aromatic hydrocarbons (PAHs) and PCBs emitted by this particular stationary source.
Assessing The Possibility Of Corrosion Occurrence In Metallic Stacks Caused By Hydrochloric Acid, João F. Gomes
Assessing The Possibility Of Corrosion Occurrence In Metallic Stacks Caused By Hydrochloric Acid, João F. Gomes
João F Gomes
This article presents a simple method to estimate the possibility of corrosion in metallic stacks and surfaces due to hydrochloric acid deposition from stack gases, based on the HCl content in gases and also the flue gas temperature
The Importance Of Considering Building Downwash When Assessing The Need To Heighten Stacks Of Existing Small And Medium Sized Industries, João F. Gomes
João F Gomes
No abstract provided.
Estimation Of Uncertainty In The Determination Of Nitrogen Oxides Emissions, João F. Gomes
Estimation Of Uncertainty In The Determination Of Nitrogen Oxides Emissions, João F. Gomes
João F Gomes
This paper presents a methodology for estimation of uncertainty on a reference test method for determination of nitrogen oxides concentration in gaseous emissions from stationary sources. As a first stage for identification of uncertainty sources, the test method is carefully reviewed in detail. Afterwards, these sources are quantified, bearing in mind its partial uncertainty, allowing the determination of the combined uncertainty and, finally, the expanded uncertainty. The calculation procedure was implemented into an excel calculation file. Using this file and considering several numerical applications from real situations, uncertainities around 15 mg/Nm3 over determined concentrations of 350 mg/Nm3 of NOx (expressed …
Avoid Sulfuric Acid Corrosion In Metallic Stacks, João F. Gomes
Avoid Sulfuric Acid Corrosion In Metallic Stacks, João F. Gomes
João F Gomes
Acidic gaseous effluents frequently cause corrosion on metallic stacks. This paper presents a method for prevision of probability of corrosion occurrence caused by gaseous effluents containing sulphur oxides which is based on the sulphur trioxide and moisture content measured in stack
Emissions Of Dioxin And Dibenzofuran From Electric Arc Furnaces, João F. Gomes
Emissions Of Dioxin And Dibenzofuran From Electric Arc Furnaces, João F. Gomes
João F Gomes
This paper describes work done in order to clarify the formation mechanism of highly toxic micropollutants, such as dioxins and dibenzofurans, from electric arc furnaces used in the production of carbon steel from scrap. The study is allowing to derive relationships between the levels of airborne micropollutants and the operational parameters of the production process so that an abatement of pollution could be achieved. By using the European standard method CEN 1948 for dioxin like compounds sampling and measurement, it was possible to determine the characteristic fingerprint of micropollutants emitted by this particular stationary source.
Air Quality Regulation Policy In Portugal, João F. Gomes
Air Quality Regulation Policy In Portugal, João F. Gomes
João F Gomes
Ten years after the publication of first air quality laws in Portugal, and seven years after the publication of the respective emission limits, it seems appropriate to analyse the degree of law enforcement by the Portuguese manufacturing industry. Therefore, based on the emission measurements made regularly by ISQ, as the only officially accredited laboratory, a set of about 400 sources is analysed in terms of the compliance with the emission limits regarding total suspended particulate, sulphur dioxide, nitrogen oxides and VOCs. The compliance is evaluated through a non-dimensional parameter and plotted versus the emission flow rate to derive conclusions: it …
Emission And Odour Control In Kraft Pulp Mills, João F. Gomes
Emission And Odour Control In Kraft Pulp Mills, João F. Gomes
João F Gomes
This paper describes systematic work done in the field of atmospheric emissions from Portuguese Kraft pulp mills, focused mainly on the gaseous emissions responsible for its characteristic odour. These mal-odorous gases, which were identified as hydrogen sulphide, methyl mercaptan, deimethyl mercaptan and dimethyl-disulphide, were experimentally quantified and classified into groups so that alternatives for abatement could be devised. The considered abatement techniques were evaluated economically and it was concluded that the costs to be incurred by pulp mills for an efficient abatement of TRS gases are not dramatic and could be easily covered by this industry, resulting in an evident …
Diagnostic Of Critical Circuits Of Kraft Pulp Production Process Considering The Environmental Aspects, João F. Gomes
Diagnostic Of Critical Circuits Of Kraft Pulp Production Process Considering The Environmental Aspects, João F. Gomes
João F Gomes
This paper describes systematic work done in the field of atmospheric emissions from Portuguese Kraft pulp mills. This study led to the determination of emission factors from stationary sources that proved to be an important tool to assess the need for investment on air pollution abatement equipment, namely in what concerns mal-odorous gases.
Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills (2), João F. Gomes
Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills (2), João F. Gomes
João F Gomes
This paper describes work performed on the sampling and analysis of non-condensable gases (NCG) emitted from diffuse sources of a Portuguese Kraft pulp mill, which is the background information for a NCG collection, treatment and disposal system. The variability found in the composition of the gaseous compounds showed the existence of gaseous streams other than typical total reduced sulphur (TRS) compounds as usually described. From the measured TRS concentrations and the gas flow rate from each source it was possible to calculate the emission flow rate, E, of each source. These emission flow rates were then divided into 3 categories …
Practical Determination Of Efficiency Of Electrostatic Precipitators, João F. Gomes
Practical Determination Of Efficiency Of Electrostatic Precipitators, João F. Gomes
João F Gomes
Electrostatic precipitators are one of the most efficient particulate pollution control equipments used mainly for the treatment of gaseous effluents at high flow rates. Consequently electrostatic precipitators are widely used in thermal power plants, cement plants and pulp mills. Apart from a high efficiency other advantages are related with the fact that this type of equipment has a considerable low payback time in industrial plants where the particulate recovered from the gases has commercial value and can be recycled within the industrial process itself or even sold to other industrial companies. Where sulphate (Kraft) pulp mills are concerned an electrostatic …
Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills, João F. Gomes
Characterisation Of Non-Condensable Sulphur Containing Gases From Kraft Pulp Mills, João F. Gomes
João F Gomes
This paper describes work performed on the sampling and analysis of non-condensable gases (NCG) emitted from diffuse sources of a Portuguese kraft pulp mill, which is the background information for a NCG collection, treatment and disposal system. The variability found in the composition of the gaseous compounds showed the existence of gaseous streams other than typical total reduced sulphur (TRS) compounds as usually described.
A Simple Way To Measure Particle Size, João F. Gomes
A Simple Way To Measure Particle Size, João F. Gomes
João F Gomes
The size range of particles is an important parameter for subsequent dispersion estimates and sometimes is quite useful for analysing the performance of combustion equipment as well as dedusting equipment efficiency. So far, no standard method has been developed but several laboratories use laser-beam techniques which are usually quite expensive ones. In this paper a method is presented where the particles are collected isokinetically in a filter from gases circulating in a stack as described in USEPA method 5. Afterwards particles are observed at an optical microscope and measured. In spite of some limitations this appears to be an inexpensive …
Assessment Of Opacimeter Calibration On Kraft Pulp Mills, João F. Gomes
Assessment Of Opacimeter Calibration On Kraft Pulp Mills, João F. Gomes
João F Gomes
This paper describes the methodology and specific techniques for calibrating automatic on-line industrial emission analysers, specifically equipments that measure total suspended dust installed in pulp mills within the scope of Portuguese Regulation Nº 286/93 on air quality. The calibration of opacimeters is a multi-parameter relationship instead of the bi-dimensional calibration which is used in industrial practice. For a stationary source from a pulp mill such as the recovery boiler stack, which is subjected to significant variations, the effects of parameters such as the humidity and gas temperature, deviations on isokinetism, size range of particles and characteristic transmitance of equipment are …
Pollutant Atmospheric Emissions From Portuguese Kraft Pulp Mills, João F. Gomes
Pollutant Atmospheric Emissions From Portuguese Kraft Pulp Mills, João F. Gomes
João F Gomes
This paper describes systematic work done in the field of atmospheric emissions from Portuguese Kraft pulp mills. This study led to the determination of emission factors from stationary sources that proved to be an important tool to assess the need for investment on air pollution abatement equipment.
Notice On A Method For Measuring Size Range Of Particles In Gases From Stationary Sources, João F. Gomes
Notice On A Method For Measuring Size Range Of Particles In Gases From Stationary Sources, João F. Gomes
João F Gomes
No abstract provided.