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- Atmospheric Pollution (18)
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- Research and Publications (2)
- Ultrafine particles (2)
- Unit operations and transport phenomena (2)
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- Ag@TiO2nanocomposites; Hydrogen peroxide sensor; Nonenzymatic sensor; Glassy carbon electrode; Ag@TiO2/GCE; Differential pulse voltammetry (1)
- Ag@ZnO nomposites (1)
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Articles 1 - 30 of 65
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 …
Au@Tio2 Nanocomposites For The Catalytic Degradation Of Methyl Orange And Methylene Blue: An Electron Relay Effect, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho
Au@Tio2 Nanocomposites For The Catalytic Degradation Of Methyl Orange And Methylene Blue: An Electron Relay Effect, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
Au@TiO2 nanocomposites were used for the catalytic degradation of methyl orange and methylene blue by NaBH4. A detail pathway for step by step reduction, oxidation and complete mineralization of intermediates into the respective end-products was established by UV-vis spectroscopy, chemical oxygen demand, ion chromatography and cyclic voltammetry (CV). CV studies confirmed that the dyes were reduced and oxidized to the end-products by NaBH4 in the presence of Au@TiO2 nanocomposites and O2•, •OH and HO2• radicals generated in-situ. Results suggest that Au@TiO2 nanocomposites not only assist in the decolorization of dyes, but also promote their complete mineralization into harmless end-products.
Highly Visible Light Active Ag@Zno Nanocomposites Synthesized By Gel-Combustion Route, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho
Highly Visible Light Active Ag@Zno Nanocomposites Synthesized By Gel-Combustion Route, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
Highly visible light active 1% and 3% Ag@ZnO nanocomposites were synthesized via a gel combustion route using citric acid as a fuel. The formation of the nanocomposites with enhanced properties was confirmed using a range of characterization techniques, photocatalysis and photoelectrochemical studies. Compared to the pristine ZnO nanoparticles, the Ag@ZnO nanocomposites exhibited enhanced visible light photocatalytic activity for the degradation of methylene blue and photoelectrochemical response. A mechanism was proposed to account for the photocatalytic activities of the Ag@ZnO nanocomposite that showed the surface plasmon resonance (SPR) of Ag is an effective way of enhancing the visible light photocatalytic activities.
Highly Photoactive Sno2 Nanostructures Engineered By Electrochemically Active Biofilm, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho
Highly Photoactive Sno2 Nanostructures Engineered By Electrochemically Active Biofilm, S. A. Ansari, Mohammad Mansoob Khan Dr, M. O. Ansari, J. Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
This paper reports the defect-induced band gap narrowing of pure SnO2 nanostructures (p-SnO2) using an electrochemically active biofilm (EAB). The proposed approach is biogenic, simple and green. Systematic characterization of the modified SnO2 nanostructures (m-SnO2) revealed EAB-mediated defects in pure SnO2 nanostructures (p-SnO2). m-SnO2 nanostructures in visible light showed the enhanced photocatalytic degradation of p-nitrophenol and methylene blue compared to p-SnO2 nanostructures. Photoelectrochemical studies, such as electrochemical impedance spectroscopy and linear scan voltammetry, also revealed a significant increase in the visible light response of m-SnO2 compared to p-SnO2 nanostructures. The enhanced activities of m-SnO2 in visible light was attributed to …
Band Gap Engineered Tio2 Nanoparticles For Visible Light Induced Photoelectrochemical And Photocatalytic Studies, Mohammad Mansoob Khan Dr, S A. Ansari, D Pradhan, D H. Han, J Lee, M. H. Cho
Band Gap Engineered Tio2 Nanoparticles For Visible Light Induced Photoelectrochemical And Photocatalytic Studies, Mohammad Mansoob Khan Dr, S A. Ansari, D Pradhan, D H. Han, J Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
Visible light-active TiO2 (m-TiO2) nanoparticles were obtained by an electron beam treatment of commercial TiO2 (p-TiO2) nanoparticles. The m-TiO2 nanoparticles exhibited a distinct red-shift in the UV-visible absorption spectrum and a much narrower band gap (2.85 eV) due to defects as confirmed by diffuse reflectance spectroscopy (DRS), photoluminescence (PL), X-ray diffraction, Raman spectroscopy, electron paramagnetic resonance, transmission electron microscopy, X-ray photoelectron spectroscopy (XPS), electrochemical impedance spectroscopy (EIS) and linear scan voltammetry (LSV). The XPS revealed changes in the surface states, composition, Ti4+ to Ti3+ ratio, and oxygen deficiencies in the m-TiO2. The valence band XPS, DRS and PL results were …
Optimization Of Gold Nanoparticles Synthesis By Stainless Steel For H2o2 And Glucose Detection, T. H. Han, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho
Optimization Of Gold Nanoparticles Synthesis By Stainless Steel For H2o2 And Glucose Detection, T. H. Han, Mohammad Mansoob Khan Dr, J. Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
The synthesis of (+)AuNPs procedure using a stainless-steel mesh was optimized. The optimal synthetic parameters were found to be one piece of stainless-steel mesh (22.5 cm2 in surface area) in 100 mL of a 1 mM precursor, precursor solution pH 4, and reaction temperature of 30°C. Under the optimal conditions, the as-synthesized (+)AuNPs were highly positively charged (+24.2 mV). Therefore, the as-synthesized (+)AuNPs act as a peroxidase mimic and provide a simple, fast, highly sensitive and selective colorimetric method for H2O2 detection with a detection limit of 0.06 mM in the linear range from 0.06 mM to 4.29 mM.
Novel Ag@Tio2 Nanocomposite Synthesized By Electrochemically Active Biofilm For Nonenzymatic Hydrogen Peroxide Sensor, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho
Novel Ag@Tio2 Nanocomposite Synthesized By Electrochemically Active Biofilm For Nonenzymatic Hydrogen Peroxide Sensor, Mohammad Mansoob Khan Dr, S. A. Ansari, J. Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
A novel nonenzymatic sensor for H2O2 was developed based on an Ag@TiO2 nanocomposite synthesized using a simple and cost effective approach with an electrochemically active biofilm. The optical, structural, morphological and electrochemical properties of the as-prepared Ag@TiO2 nanocomposite were examined by UV-vis spectroscopy, x-ray diffraction, transmission electron microscopy and cyclic voltammetry (CV). The Ag@TiO2 nanocomposite was fabricated on a glassy carbon electrode (GCE) and their electrochemical performance was analyzed by CV, differential pulse voltammetry and electrochemical impedance spectroscopy. The Ag@TiO2 nanocomposite modified GCE (Ag@TiO2/GCE) displayed excellent performance towards H2O2 sensing at −0.73 V in the linear response range from 0.83 …
Simultaneous Enhancement Of The Methylene Blue Degradation And Power Generation In Microbial Fuel Cell By Gold Nanoparticles, Mohammad Mansoob Khan Dr, T. H. Han, S. Kalathil, J. Lee, M. H. Cho
Simultaneous Enhancement Of The Methylene Blue Degradation And Power Generation In Microbial Fuel Cell By Gold Nanoparticles, Mohammad Mansoob Khan Dr, T. H. Han, S. Kalathil, J. Lee, M. H. Cho
Dr. Mohammad Mansoob Khan
This study examined the effect of positively charged gold nanoparticles ((+)AuNPs) on the enhancement of methylene blue (MB) degradation in microbial fuel cell (MFC) cathode. The maximum electricity production of 36.56 mW/m2 and complete MB degradation were achieved simultaneously. The MFC performance and MB degradation are strictly dependent on cathodic conditions, such as N2 bubbling, air bubbling and addition of H2O2. MB was reduced rapidly under anaerobic condition, whereas complete oxidative mineralization of MB occurred in the presence of dissolved oxygen (DO) or H2O2. (+)AuNPs enhanced the electricity generation in the MFCs involving MB degradation owing to its electron relay …
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.
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.
Determination Of Airborne Nanoparticles From Welding Operations, João F. Gomes
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
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
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 …
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 …
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 …
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, …
2009 Report Of Crerg Research Activities, João F. Gomes
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
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
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.