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Full-Text Articles in Nanoscience and Nanotechnology

Novel Nanocomposite Clay Brick For Strain Sensing In Structural Masonry, F. Ubertini, A. D'Alessandro, A. L. Materazzi, Simon Laflamme, Austin Downey Feb 2018

Novel Nanocomposite Clay Brick For Strain Sensing In Structural Masonry, F. Ubertini, A. D'Alessandro, A. L. Materazzi, Simon Laflamme, Austin Downey

Simon Laflamme

The monitoring of civil structures is critical in ensuring users' safety. Structural health monitoring (SHM) is the automation of this monitoring task. It is typically used to identify incipient damages through a spatio-temporal comparison in structural behaviors. Traditional sensors exhibit mechanical characteristics that are usually very different from those of the structures they monitor, which is a factor limiting their durability. Ideally, the material of a sensor would share the same mechanical characteristics as the material onto or into which it is installed. A solution is to fabricate multifunctional materials, capable of serving both structural and sensing functions, also known ...


Continuous And Embedded Solutions For Shm Of Concrete Structures Using Changing Electrical Potential In Self-Sensing Cement-Based Composites, Austin Downey, Enrique Garcia-Macias, Antonella D'Alessandro, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini Feb 2018

Continuous And Embedded Solutions For Shm Of Concrete Structures Using Changing Electrical Potential In Self-Sensing Cement-Based Composites, Austin Downey, Enrique Garcia-Macias, Antonella D'Alessandro, Simon Laflamme, Rafael Castro-Triguero, Filippo Ubertini

Simon Laflamme

Interest in the concept of self-sensing structural materials has grown in recent years due to its potential to enable continuous low-cost monitoring of next-generation smart-structures. The development of cement-based smart sensors appears particularly well suited for monitoring applications due to their numerous possible field applications, their ease of use and long-term stability. Additionally, cement-based sensors offer a unique opportunity for structural health monitoring of civil structures because of their compatibility with new or existing infrastructure. Particularly, the addition of conductive carbon nanofillers into a cementitious matrix provides a self-sensing structural material with piezoresistive characteristics sensitive to deformations. The strain-sensing ability ...


Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen Jun 2017

Platinum Nanoparticle Decorated Sio2 Microfibers As Catalysts For Micro Unmanned Underwater Vehicle Propulsion, Bolin Chen, Nathaniel T. Garland, Jason Geder, Marius Pruessner, Eric Mootz, Allison Cargill, Anne Leners, Granit Vokshi, Jacob Davis, Wyatt Burns, Michael A. Daniele, Josh Kogot, Igor L. Medintz, Jonathan C. Claussen

Jonathan C. Claussen

Micro unmanned underwater vehicles (UUVs) need to house propulsion mechanisms that are small in size but sufficiently powerful to deliver on-demand acceleration for tight radius turns, burst-driven docking maneuvers, and low-speed course corrections. Recently, small-scale hydrogen peroxide (H2O2) propulsion mechanisms have shown great promise in delivering pulsatile thrust for such acceleration needs. However, the need for robust, high surface area nanocatalysts that can be manufactured on a large scale for integration into micro UUV reaction chambers is still needed. In this report, a thermal/electrical insulator, silicon oxide (SiO2) microfibers, is used as a support for platinum nanoparticle (PtNP) catalysts ...


Biodiesel Production From Waste Trying Oils Over Lime Catalysts, João F. Gomes Jan 2013

Biodiesel Production From Waste Trying Oils Over Lime Catalysts, João F. Gomes

João F Gomes

No abstract provided.


Monitoring Exposure To Airborne Ultrafine Particles In Lisbon, Portugal, João F. Gomes Jan 2012

Monitoring Exposure To Airborne Ultrafine Particles In Lisbon, Portugal, João F. Gomes

João F Gomes

No abstract provided.


Comparison Of Deposited Surface Area Of Airborne Ultrafine Particles Generated From Two Welding Processes, João F. Gomes Jan 2012

Comparison Of Deposited Surface Area Of Airborne Ultrafine Particles Generated From Two Welding Processes, João F. Gomes

João F Gomes

No abstract provided.


Determination Of Airborne Nanoparticles From Welding Operations, João F. Gomes Dec 2011

Determination Of Airborne Nanoparticles From Welding Operations, João F. Gomes

João F Gomes

The aim of this study is to assess the levels of airborne ultrafine particles emitted in welding processes (tungsten inert gas (TIG), metal active gas (MAG) of carbon steel and friction stir welding (FSW) of aluminium) in terms of deposited area in pulmonary alveolar tract using a Nanoparticle Surface Area Monitor (NSAM) analyzer. The obtained results showed the dependence from process parameters on emitted ultrafine particles and demonstrated the presence of ultrafine particles compared to background levels. Data indicated that the process that resulted in the lowest levels of alveolar deposited surface area (ADSA) was FSW, followed by TIG and ...


Exposure To Airborne Ultrafine Particles From Cooking In Portuguese Homes, João F. Gomes Dec 2011

Exposure To Airborne Ultrafine Particles From Cooking In Portuguese Homes, 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 Dec 2011

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 ...


Study On The Use Of Mgal Hydrotalcites As Solid Heterogeneous Catalysts For Biodiesel Production, João F. Gomes Dec 2011

Study On The Use Of Mgal Hydrotalcites As Solid Heterogeneous Catalysts For Biodiesel Production, João F. Gomes

João F Gomes

This paper, reports experimental work on the use of new heterogeneous solid basic catalysts for biodiesel production: double oxides of Mg and Al, produced by calcination, at high temperature, of MgAl lamellar structures, the hydrotalcites (HT). The most suitable catalyst system studied are hydrotalcite Mg:Al 2:1 calcinated at 507 ºC and 700 ºC, leading to higher values of FAME also in the second reaction stage. One of the prepared catalysts resulted in 97.1 % Fatty acids methyl esters (FAME) in the 1st reaction step, 92.2 % FAME in the 2nd reaction step and 34 % FAME in the 3rd ...


Notice On A Case Study On The Utilization Of Wind Energy Potential On A Remote And Isolated Small Wastewater Treatment Plant, João F. Gomes Aug 2011

Notice On A Case Study On The Utilization Of Wind Energy Potential On A Remote And Isolated Small Wastewater Treatment Plant, João F. Gomes

João F Gomes

Small wastewater treatment plants (WWTP) are frequently located, by necessity, in remote and isolated sites, which increases the difficulty of its energy supply. Some of them are located near the seaside, in environmental sensible zones, and due to tourism activity of these sites, seasonal effects related with population size fluctuation can occur, which can originate certain inefficiencies concerning WWTP design and energy supply. The objective of this paper is to describe a step by step procedure for evaluation of the wind potential of sites that are dependent of in-situ energy generation, as well as, a case study on the utilization ...


Study On The Glycerolysis Reaction Of High Free Fatty Acid Oils For Use As Biodiesel Feedstock, João F. Gomes Jan 2011

Study On The Glycerolysis Reaction Of High Free Fatty Acid Oils For Use As Biodiesel Feedstock, João F. Gomes

João F Gomes

Biodiesel is the main alternative to fossil diesel and it may be produced from different feedstocks such as semi-refined vegetable oils, waste frying oils or animal fats. However, these feedstocks usually contain significant amounts of free fatty acids (FFA) that make them inadequate for the direct base catalyzed transesterification reaction (where the FFA content should be lower than 4%). The present work describes a possible method for the pre-treatment of oils with high content of FFA (20 to 50%) by esterification with glycerol. In order to reduce the FFA content, the reaction between these FFA and an esterification agent is ...


Design Of A New Test Chamber For Evaluation Of The Toxicity Of Rubber Infill, João F. Gomes Jan 2011

Design Of A New Test Chamber For Evaluation Of The Toxicity Of Rubber Infill, João F. Gomes

João F Gomes

A test chamber was projected and built (according to ISO 16000-9 Standard) to simulate atmospheric conditions experienced by rubber infill (when applied in synthetic turf pitches) and measure accurately the airborne emissions of pollutants such as dusts and volatile organic compounds (VOC), as well as pollutants present in leacheates. It should be pointed out that standard ISO 16000-9 is only concerned with the determination of the emission of VOC from building products and furnishing (not specific of synthetic turf materials), while other standards are concerned with the emission of leacheates only. This procedure is to be considered as a technical ...


What Is A Chemical Engineer ?, João F. Gomes Jan 2011

What Is A Chemical Engineer ?, João F. Gomes

João F Gomes

No abstract provided.


On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes Jan 2011

On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes

João F Gomes

No abstract provided.


Advances On The Development Of Novel Heterogeneous Catalysts For Transesterification Of Triglycerides In Biodiesel, João F. Gomes Jan 2010

Advances On The Development Of Novel Heterogeneous Catalysts For Transesterification Of Triglycerides In Biodiesel, João F. Gomes

João F Gomes

This paper describes experimental work done towards the search for more profitable and sustainable alternatives regarding biodiesel production, using heterogeneous catalysts instead of the conventional homogenous alkaline catalysts, such as NaOH, KOH or sodium methoxide, for the methanolysis reaction. This experimental work is a first stage on the development and optimization of new solid catalysts, able to produce biodiesel from vegetable oils. The heterogeneous catalytic process has many differences from the currently used in industry homogeneous process. The main advantage is that, it requires lower investment costs, since no need for separation steps of methanol/catalyst, biodiesel/catalyst and glycerine ...


Study On The Activity Of New Amine Based Absorbents For Co2 Absorption From Flue Gases, João F. Gomes Jan 2010

Study On The Activity Of New Amine Based Absorbents For Co2 Absorption From Flue Gases, João F. Gomes

João F Gomes

The capture of CO2 from flue gases can be done by chemical absorption with aqueous amine solutions like MEA (monoethanolamine). Although this is a proven process, there are still operational problems to overcome [1], namely those resulting from solvent degradation, precipitation, corrosion and foaming. Also, the absorption capacity of the most current amines must be improved in order to obtain a more profitable operation. It has been shown previously that relationships exist between the amine structure and the activity/capacity for CO2 absorption. The introduction of amine substituents at the α-carbon creates a carbamate instability, which causes the hydrolysis to ...


A Simulation Study On The Abatement Of Co2 Emissions By De-Absorption, João F. Gomes Jan 2010

A Simulation Study On The Abatement Of Co2 Emissions By De-Absorption, João F. Gomes

João F Gomes

Due to the adverse effect of CO2 from fossil fuel combustion on the earth’s ecosystems, the most cost effective method for CO2 capture is an important area of research. The predominant process for CO2 capture currently employed by industry is chemical absorption in amine solutions. A dynamic model for the de-absorption process was developed with Monoethanolamine (MEA) solution. Henry’s law was used for modeling the vapour phase equilibrium of the CO2, and fugacity ratios calculated by the Peng Robinson equation of state (EOS) were used for H2O, MEA, N2 and O2. Chemical reactions between CO2 and MEA were ...


Studies On The Development Of Novel Heterogeneous Catalysts For Transesterification Of Triglycerides In Biodiesel, João F. Gomes Jan 2010

Studies On The Development Of Novel Heterogeneous Catalysts For Transesterification Of Triglycerides In Biodiesel, João F. Gomes

João F Gomes

No abstract provided.


2009 Report Of Crerg Research Activities, João F. Gomes Dec 2009

2009 Report Of Crerg Research Activities, João F. Gomes

João F Gomes

No abstract provided.


Toxicological Assessment Of Coated Versus Uncoated Rubber Granulates Obtained From Used Tires For Use In Sport Facilities, João F. Gomes Dec 2009

Toxicological Assessment Of Coated Versus Uncoated Rubber Granulates Obtained From Used Tires For Use In Sport Facilities, João F. Gomes

João F Gomes

Reuse of tire crumb in sport facilities is currently a very cost-effective waste management measure. Considering that incorporation of the waste materials in artificial turf would be facilitated if the rubber materials were already colored green, coatings were specifically developed for this purpose. This paper presents an experimental toxicological and environmental assessment aimed at comparing the obtained emissions to the environment in terms of polycyclic aromatic hydrocarbons (PAHs), heavy metals, and ecotoxicity for coated and noncoated rubber granulates. This study is a comprehensive evaluation of the major potential critical factors related with the release of all of these classes of ...


Endargement Of Undeveloped Areas Of Serbia By Forest Fires, João F. Gomes Jan 2009

Endargement Of Undeveloped Areas Of Serbia By Forest Fires, João F. Gomes

João F Gomes

Considering the significance of discovering the causes of forest fires, the hypothesis on the solar activity is presented (i.e. physical–chemical characteristics of the solar wind) as the possible cause of these natural disasters. The empirical confirmation of the mentioned hypothesis was disabled by the non existence of an adequate data base on the (regional) distribution of the number of fires and burned areas on the level of Serbia. Therefore an emphasis is put on theoretical explanations, but also on the characteristic situations in which there is an agreement between the processes occurring on the Sun and fire phenomena ...


2008 Report Of Crerg Research Activities, João F. Gomes Jan 2009

2008 Report Of Crerg Research Activities, João F. Gomes

João F Gomes

No abstract provided.


Study Of A Nanoscale Water Cluster By Atomic Force Microscopy, Manhee Lee, Baekman Sung, Nicole N. Hashemi, Wonho Jhe Jan 2009

Study Of A Nanoscale Water Cluster By Atomic Force Microscopy, Manhee Lee, Baekman Sung, Nicole N. Hashemi, Wonho Jhe

Nastaran Hashemi

We present a novel method for investigating a nanometric cluster of water molecules, which includes the formation and manipulation of nanometric water, and the measurement of its mechanical properties. The atomic force microscope based on the quartz tuning-fork sensor is employed to form and manipulate the nanometric water, and the theoretical tool of amplitude-modulation atomic force microscopy is used to obtain the elasticity, viscosity and dissipation energy of it. With high vertical resolution less than [similar]0.1 nm and high force sensitivity of [similar]0.01 N m−1, this tool facilitates the stable formation and manipulation of a ...


Assessment Of The Impact Of The European Co2 Emissions Trading Scheme On The Portuguese Chemical Industry, João F. Gomes Dec 2008

Assessment Of The Impact Of The European Co2 Emissions Trading Scheme On The Portuguese Chemical Industry, João F. Gomes

João F Gomes

No abstract provided.


Estimating Local Greenhouse Gas Emissions - A Case Study On A Portuguese Municipality, João F. Gomes Jan 2008

Estimating Local Greenhouse Gas Emissions - A Case Study On A Portuguese Municipality, João F. Gomes

João F Gomes

This paper describes the study that led to the development of a carbon dioxide emissions matrix for the Oeiras municipality, one of the largest Portuguese municipalities, located in the metropolitan area of Lisbon. This matrix takes into account the Greenhouse Gases (GHG) Emissions, due an increase of electricity demand in buildings as well as solid and liquid wastes treatment, from the domestic and services sectors. Using emission factors that were calculated from the relationship between the electricity produced and amount of treated wastes, the GHG emissions in the Oeiras municipality, were estimated for a time series of 6 years (1998 ...


Dynamic Simulation Of Co2 Absorption From Post Combustion Gases, João Gomes Jan 2008

Dynamic Simulation Of Co2 Absorption From Post Combustion Gases, João Gomes

João F Gomes

CO2 capture from combustion flue gases is currently an issue of main interest due to the high taxes being imposed on industrial companies as a measure to achieve CO2 emissions abatement. CO2 capture can be efficiently achieved by gas absorption using amines, namely Monoethanolamine (MEA). Based on henrys law, validated with previously published experimental work, this study considers the development of a dynamic model of an absorption column for post combustion CO2 capture. A dynamic model of the temperature swing de-absorption process was developed with the integration of both models for absorption and de-absorption (with the introduction of heat exchangers ...


Reflexions On The Use Of Renewable Power Sources And Nuclear Energy In Portugal, João F. Gomes Jan 2008

Reflexions On The Use Of Renewable Power Sources And Nuclear Energy In Portugal, João F. Gomes

João F Gomes

This paper analyses the current energy balance of Portugal, considering the actual sources which are mainly traditional fossil fuels, hydroelectric power and renewables. Other potential sources are discussed also and taken into consideration in view of the previewed evolution of the country in energetic terms. Among these, nuclear power, once regarded as an option, is now being re-considered. This paper also sums up the main issues to be considered in a future debate on the subject.


Emissions Of Polyciclic Aromatic Hidrocarbons And Polyciclic Carbonyl Bifenils From Electric Arc Furnaces, João F. Gomes Dec 2007

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 Jan 2007

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