Open Access. Powered by Scholars. Published by Universities.®
Nanoscience and Nanotechnology Commons™
Open Access. Powered by Scholars. Published by Universities.®
- Keyword
-
- Atmospheric Pollution (15)
- Catalysis (5)
- Heterogeneous catalysis (5)
- Greenhouse Gas Emissions (4)
- Indoor air quality (4)
-
- Zeolite Synthesis (4)
- Biodiesel (3)
- Energy (3)
- Forest Fires (3)
- Portugal (3)
- Zeolites (3)
- Corrosion (2)
- Elasticity (2)
- Entropy (2)
- Environmental Engineering (2)
- Heterogeneous Catalysts (2)
- Ionothermal synthesis (2)
- Kraft Pulp Mills ; Atmospheric Emissions (2)
- Lubricant oil (2)
- Nanocrystals (2)
- Nanoparticles (2)
- Non-Newtonian flow (2)
- Polymer solutions (2)
- Toxicology (2)
- Unit operations and transport phenomena (2)
- Wastewater treatment (2)
- Water sorption (2)
- Welding (2)
- Zeolite (2)
- Acid oils (1)
- Publication Year
- Publication
- File Type
Articles 1 - 30 of 59
Full-Text Articles in Nanoscience and Nanotechnology
Nanonickel Catalyst Reinforced With Silicate For Methane Decomposition To Produce Hydrogen And Nanocarbon: Synthesis By Co-Precipitation Cum Modified Stöber Method, Upm Ashik, Wma Wan Daud
Nanonickel Catalyst Reinforced With Silicate For Methane Decomposition To Produce Hydrogen And Nanocarbon: Synthesis By Co-Precipitation Cum Modified Stöber Method, Upm Ashik, Wma Wan Daud
upm ashik
Co-precipitation cum modified Stöber method is a continuous process avoiding application of higher temperature treatment before supporting nanometal with SiO2, irrespective of pre-preparation methods. We have conducted the co-precipitation process without undertaking calcination under air in order to avoid even a partial particle agglomeration and hence maintained average particle size [similar]30 nm after enforcing with SiO2. This is the first report adopting such an unceasing preparation for preparing metal/silicate nanostructures. Furthermore, n-Ni/SiO2 nanostructured catalysts were used for thermocatalytic decomposition of methane to produce hydrogen and carbon nanotubes. The catalyst was found to be very stable and the methane transformation activity …
Biodiesel Production From Waste Trying Oils Over Lime Catalysts, João F. Gomes
Biodiesel Production From Waste Trying Oils Over Lime Catalysts, João F. Gomes
João F Gomes
No abstract provided.
The Impact Of Controlled Solvent Exposure On The Morphology, Structure And Function Of Bulk Heterojunction Solar Cells, Raghavendra R. Hegde Dr
The Impact Of Controlled Solvent Exposure On The Morphology, Structure And Function Of Bulk Heterojunction Solar Cells, Raghavendra R. Hegde Dr
Raghavendra R Hegde Dr
Films of poly(3-hexyl thiophene) (P3HT):[6,6]-phenyl C61-butyric acid methyl ester (PCBM) were controllably exposed to CS2 vapor in a column with a linear solvent vapor pressure gradient. Changes in the morphology of the P3HT:PCBM thin film were monitored and correlated to the ability of this thin film to act as the active layer in an organic solar cell. The results show that the crystallinity and crystal size of the P3HT increase initially with solvent vapor pressure and annealing time, but longer exposure to solvent decreases P3HT crystallinity and photovoltaic efficiency. Neutron reflectivity indicates that the PCBM segregates to the Si substrate …
Temperature Dependence Anomalous Dielectric Relaxation In Co Doped Zno Nanoparticles, Sajid Ali Ansari
Temperature Dependence Anomalous Dielectric Relaxation In Co Doped Zno Nanoparticles, Sajid Ali Ansari
Sajid Ali Ansari
We have reported temperature and frequency dependence of dielectric behaviour of nanocrystalline Zn1-xCoxO (x = 0.0, 0.01, 0.05 and 0.1) samples prepared by gel-combustion method. The synthesized samples were examined by x-ray diffraction (XRD), scanning electron microscopy (SEM) and LCR-meter, respectively. The XRD analysis reveals that ZnO has a hexagonal (wurtzite) crystal structure. The morphology and size of the nanoparticles (∼10-25 nm) were observed by SEM for 5% Co doped ZnO sample. In dielectric properties, complex permittivity (ɛ* = ɛ’-jɛ”), loss tangent (tanδ) and ac conductivity (σac) in the frequency range 75 kHz - 5 MHz were analyzed with temperature …
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.
Comparison Of Deposited Surface Area Of Airborne Ultrafine Particles Generated From Two Welding Processes, João F. Gomes
Comparison Of Deposited Surface Area Of Airborne Ultrafine Particles Generated From Two Welding Processes, João F. Gomes
João F Gomes
No abstract provided.
Capturing Ultrasmall Emt Zeolite From Template-Free Systems, Eng-Poh Ng Dr.
Capturing Ultrasmall Emt Zeolite From Template-Free Systems, Eng-Poh Ng Dr.
Eng-Poh Ng
No abstract provided.
Study On The Use Of Mgal Hydrotalcites As Solid Heterogeneous Catalysts For Biodiesel Production, João F. Gomes
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 reaction …
Notice On A Case Study On The Utilization Of Wind Energy Potential On A Remote And Isolated Small Wastewater Treatment Plant, João F. Gomes
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
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
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
On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes
On The Toxicological Effects Of Airborne Nanoparticles From Welding Processes, João F. Gomes
João F Gomes
No abstract provided.
Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr.
Nanosized Molecular Sieves Utilized As An Environmentally Friendly Alternative To Antioxidants For Lubricant Oils, Eng-Poh Ng Dr.
Eng-Poh Ng
Lubricants play a significant part in current environmental considerations since they are an integral and indispensable component of modern technology. The production, application and disposal of the lubricants have to follow increasingly strict requirements for protecting the environment and living organisms. In this respect, molecular sieve (LTL type zeolite) is investigated as a potential environmentally friendly alternative to traditional antioxidant additives for lubricant oils. Accelerated oxidation experiments using pure base oil and additivated base oil in the presence of the LTL molecular sieve are carried out in parallel, and the oxidation processes are monitored by FT-IR spectroscopy, spectrophotometry, chromatography, total …
Advances On The Development Of Novel Heterogeneous Catalysts For Transesterification Of Triglycerides In Biodiesel, João F. Gomes
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/catalyst. This work …
Study On The Activity Of New Amine Based Absorbents For Co2 Absorption From Flue Gases, João F. Gomes
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 go …
A Simulation Study On The Abatement Of Co2 Emissions By De-Absorption, João F. Gomes
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 included in …
Studies On The Development Of Novel Heterogeneous Catalysts For Transesterification Of Triglycerides In Biodiesel, João F. Gomes
Studies On The Development Of Novel Heterogeneous Catalysts For Transesterification Of Triglycerides In Biodiesel, João F. Gomes
João F Gomes
No abstract provided.
Micro- To Macroscopic Observations Of Mnalpo-5 Nanocrystal Growth In Ionic-Liquid Media, Eng-Poh Ng Dr.
Micro- To Macroscopic Observations Of Mnalpo-5 Nanocrystal Growth In Ionic-Liquid Media, Eng-Poh Ng Dr.
Eng-Poh Ng
Micro- and macroscopic studies of nucleation and growth processes of MnAlPO-5 nanosized crystals under ionothermal synthesis conditions are reported herein. The samples treated at 150 8C were extracted from the reaction mixture at various stages of crystallization, and characterized by XRD; SEM; thermogravimetric analysis (TGA); 31P and 27Al solid-state magic angle spinning (MAS) NMR, Raman, UV/Vis, and X-ray fluorescence spectroscopy (XRF). The starting raw materials (alumina, manganese, and phosphorous) were dissolved completely in the ionic liquid and transformed into an amorphous solid after 5 h of ionothermal treatment. This amorphous solid then undergoes structural changes over the following 5–25 h, …
Dynamics Of Individual Molecules Of Linear Polyethylene Liquids Under Shear: Atomistic Simulation And Comparison With A Free-Draining Bead-Rod Chain, David Keffer, J. M. Kim, B. J. Edwards, B. Khomami
Dynamics Of Individual Molecules Of Linear Polyethylene Liquids Under Shear: Atomistic Simulation And Comparison With A Free-Draining Bead-Rod Chain, David Keffer, J. M. Kim, B. J. Edwards, B. Khomami
David Keffer
Nonequilibrium molecular dynamics (NEMD) simulations of a dense liquid composed of linear polyethylene chains were performed to investigate the chain dynamics under shear. Brownian dynamics (BD) simulations of a freely jointed chain with equivalent contour length were also performed in the case of a dilute solution. This allowed for a close comparison of the chain dynamics of similar molecules for two very different types of liquids. Both simulations exhibited a distribution of the end-to-end vector, |Rete|, with Gaussian behavior at low Weissenberg number (Wi). At high Wi, the NEMD distribution was bimodal, with two peaks …
پاسخهای تشریحی سوالات کنکور کارشناسی ارشد رشته شیمی کاربردی-چاپ دوم-ویرایش جدید, A. Khataee, M. H. Rasoulifard, Mir Saeed Seyed Dorraji, V. Vatanpoor
پاسخهای تشریحی سوالات کنکور کارشناسی ارشد رشته شیمی کاربردی-چاپ دوم-ویرایش جدید, A. Khataee, M. H. Rasoulifard, Mir Saeed Seyed Dorraji, V. Vatanpoor
Mir saeed Seyed Dorraji
No abstract provided.
Endargement Of Undeveloped Areas Of Serbia By Forest Fires, João F. Gomes
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 in the …
2008 Report Of Crerg Research Activities, João F. Gomes
2008 Report Of Crerg Research Activities, João F. Gomes
João F Gomes
No abstract provided.
Discrete Mnalpo-5 Nanocrystals Synthesized By An Ionothermal Approach, Eng-Poh Ng, Satpal Singh Sekhon, Svetlana Mintova
Discrete Mnalpo-5 Nanocrystals Synthesized By An Ionothermal Approach, Eng-Poh Ng, Satpal Singh Sekhon, Svetlana Mintova
Eng-Poh Ng
Discrete MnAlPO-5 nanocrystals with monomodal particle size distribution (diameter of 80 nm) were synthesized using an ionothermal technique; the pore filling effect of the ionic liquid molecules during the synthesis of microporous nanocrystals is verified.
Selective Capture Of Water Using Microporous Adsorbents To Increase The Lifetime Of Lubricants, Eng-Poh Ng, Luc Delmotte, Svetlana Mintova
Selective Capture Of Water Using Microporous Adsorbents To Increase The Lifetime Of Lubricants, Eng-Poh Ng, Luc Delmotte, Svetlana Mintova
Eng-Poh Ng
Eco-recycling towards an increase of the lifetime of lubricating mineral oil by selective capturing of water with nanosized microporous aluminophosphate and aluminosilicate materials is reported. Quantitative water measurements of oxidized lubricating oil before and after treatment with microporous materials were carried out by FT-IR spectroscopy combined with Karl Fischer titration method. The high selectivity of the nanosized aluminophosphate to water without adsorbing other additives in comparison to nanosized aluminosilicates that are adsorbing altogether polar oxidation products, ionic additives and water are revealed. A removal of nearly 98 % of moisture from the lubricating oil at ambient condition is achieved, which …
Self-Consistent Multiscale Modeling In The Presence Of Inhomogeneous Fields, David Keffer
Self-Consistent Multiscale Modeling In The Presence Of Inhomogeneous Fields, David Keffer
David Keffer
Molecular dynamics (MD) simulations of a Lennard–Jones fluid in an inhomogeneous external field generate steady-state profiles of density and pressure with nanoscopic heterogeneities. The continuum level of mass, momentum, and energy transport balances is capable of reproducing the MD profiles only when the equation of state for pressure as a function of density is extracted directly from the molecular level of description. We show that the density profile resulting from simulation is consistent with both a molecular-level theoretical prediction from statistical mechanics as well as the solution of the continuum-level set of differential equations describing the conservation of mass and …
Nanoporous Materials With Enhanced Hydrophilicity And High Water Capacity, Eng-Poh Ng, Svetlana Mintova
Nanoporous Materials With Enhanced Hydrophilicity And High Water Capacity, Eng-Poh Ng, Svetlana Mintova
Eng-Poh Ng
The main types of nanoporous adsorbents for water are identified and described with emphasis on the mechanism of adsorption, modification, improvement of the water sorption capacity, possible regeneration, and stabilization. Among the three main groups of water sorbents, i.e. inorganic materials (zeolites, clays, silica), carbon based materials and organic polymers, the first one is described in details. The significance of their porosity, chemical and structural features relative to the water adsorptive properties of each inorganic type materials is reviewed. Important features for silicates, zeolites, aluminophosphates, mesoporous materials and clays are described, which define the interactions between the water and the …
Removal Of Organic Dyes From Industrial Wastewaters Using Uv/H2o2, Uv/H2o2/Fe (Ii), Uv/H2o2/Fe (Iii) Processes (Persian Paper), Mir Saeed Seyed Dorraji
Removal Of Organic Dyes From Industrial Wastewaters Using Uv/H2o2, Uv/H2o2/Fe (Ii), Uv/H2o2/Fe (Iii) Processes (Persian Paper), Mir Saeed Seyed Dorraji
Mir saeed Seyed Dorraji
UV/H2O2, UV/H2O2/Fe (II) and UV/H2O2/Fe (III) processes are very effective in removing pollutants from wastewater and can be used for treatment of dyestuff units wastewaters. In this study, Rhodamine B was used as a typical organic dye. Rhodamine B has found wide applications in wax, leather, and paper industries. The results from this study showed that this dye was degradable in the presence of hydrogen peroxide under UV-C irradiation (30W mercury light) and Photo-Fenton process. The dye was resistant to UV irradiation. In the absence of UV irradiation, the decolorization efficiency was very negligible in the presence of hydrogen. Theeffects …
Supercritical Water Oxidation Process And Its Application In Treatment Of Industrial Wastewater (Persian Paper), N. Daneshvar, S. Aber, Mir Saeed Seyed Dorraji, M. Zarei, M. H. Rasoulifard
Supercritical Water Oxidation Process And Its Application In Treatment Of Industrial Wastewater (Persian Paper), N. Daneshvar, S. Aber, Mir Saeed Seyed Dorraji, M. Zarei, M. H. Rasoulifard
Mir saeed Seyed Dorraji
In the last two decades, supercritical water has become an interesting medium for chemistry. One of its most investigated applications is the oxidative treatment of aqueous wastes containing organic compound in the so-called “supercritical water oxidation”. In this technology, supercritical water acts as a non-polar solvent. Consequently, even non-polar organic compounds and gases like oxygen become completely miscible with the supercritical fluid. During the supercritical water oxidation (SCWO) process, the organic compounds react completely with oxidant –mostly oxygen- in a single phase reaction forming CO2 and H2O. The hetero-atoms present in the organic wastes are transformed into the mineral acids. …
Estimating Local Greenhouse Gas Emissions - A Case Study On A Portuguese Municipality, João F. Gomes
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 …