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Full-Text Articles in Engineering

Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem Dec 2012

Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem

Long D Nghiem

Significant adsorption of sulfamethoxazole and carbamazepine to powdered activated carbon (PAC) was confirmed by a series of adsorption tests. In contrast, adsorption of these micropollutants to the sludge was negligible. The removal of these compounds in membrane bioreactor (MBR) was dependent on their hydrophobicity and loading as well as the PAC dosage. Sulfamethoxazole exhibited better removal rate during operation under no or low (0.1 g/L) PAC dosage. When the PAC concentration in MBR was raised to 1.0 g/L, a sustainable and significantly improved performance in the removal of both compounds was observed – the removal efficiencies of sulfamethoxazole and carbamazepine …


Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou Nov 2012

Silicon/Single-Walled Carbon Nanotube Composite Paper As A Flexible Anode Material For Lithium Ion Batteries, Shulei Chou, Yue Zhao, Jiazhao Wang, Zhixin Chen, Hua-Kun Liu, S. X. Dou

Shulei Chou

Flexible silicon/single-walled carbon nanotube (Si/SWCNT) composite paper was prepared using the pulsed laser deposition (PLD) method to deposit Si onto SWCNT paper. In the composite, Si mainly shows nanoworm-like morphology. Increasing deposition time results in an increased amount of Si microspheres. Electrochemical measurements show that the capacity of the composite paper is improved by the presence of Si. The Si/SWCNT composite with only 2.2% Si shows a capacity of 163 mA h g−1 at a current density of 25 mA g−1 up to 50 cycles, which is more than 60% improvement of the capacity of pristine CNT paper. The Si …


High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou Nov 2012

High-Surface-Area -Fe2o3/Carbon Nanocomposite: One-Step Synthesis And Its Highly Reversible And Enhanced High-Rate Lithium Storage Properties, S X. Dou, David Wexler, Jiazhao Wang, Hua-Kun Liu, Konstantin K. Konstantinov, Chao Zhong, Shulei Chou

Shulei Chou

Hollow-structured α-Fe2O3/carbon (HIOC) nanocomposite with a high surface area of around 260 m2 g−1 was synthesized by a one-step, in situ, and industrially-oriented spray pyrolysis method using iron lactate and sucrose solution as the precursors. The small α-Fe2O3 nanocrystals were highly dispersed inside amorphous carbon to form a carbon nanocomposite. Electrochemical measurements showed that the carbon played an important role in affecting both the cycle life and the rate capability of the electrode. The HIOC composites showed the best electrochemical performance in terms of high capacity (1210 mAh g−1 at a current density of 0.1 C), enhanced rate capability and …


Removal Of Trace Organic Contaminants By A Membrane Bioreactor-Granular Activated Carbon (Mbr -Gac) System, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, William E. Price, Long Nghiem Oct 2012

Removal Of Trace Organic Contaminants By A Membrane Bioreactor-Granular Activated Carbon (Mbr -Gac) System, Luong N. Nguyen, Faisal I. Hai, Jinguo Kang, William E. Price, Long Nghiem

William E. Price

The removal of trace organics by a membrane bioreactor–granular activated carbon (MBR–GAC) integrated system were investigated. The results confirmed that MBR treatment can be effective for the removal of hydrophobic (logD > 3.2) and readily biodegradable trace organics. The data also highlighted the limitation of MBR in removing hydrophilic and persistent compounds (e.g. carbamazepine, diclofenac, and fenoprop) and that GAC could complement MBR very well as a post-treatment process. The MBR– GAC system showed high removal of all selected trace organics including those that are hydrophilic and persistent to biological degradation at up to 406 bed volumes (BV). However, over an …


Zawartość Węgla I Siarki W Pyle Pm2,5 I Pm10 W Powietrzu W Centrum Krakowa, Monika Dziugieł, Marek Bogacki, Robert Oleniacz, Marian Mazur Oct 2012

Zawartość Węgla I Siarki W Pyle Pm2,5 I Pm10 W Powietrzu W Centrum Krakowa, Monika Dziugieł, Marek Bogacki, Robert Oleniacz, Marian Mazur

Robert Oleniacz

This paper presents the results of the PM2.5 and PM10 mass concentration measurements in an urban air and results obtained from the additional chemical analysis concerning carbon and sulfur content of the collected dust samples. Dust samples were collected at the measuring point located on the roof of five-storey building at the AGH University of Science and Technology in Krakow, Poland (the center of the urban area of the city). In the scope of this study the relations between the carbon and sulfur content within the collected dust samples were determined in the function of the dust fraction content and …


Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem Aug 2012

Simultaneous Activated Carbon Adsorption Within A Membrane Bioreactor For An Enhanced Micropollutant Removal, Xueqing Li, Faisal I. Hai, Long Nghiem

Faisal I Hai

Significant adsorption of sulfamethoxazole and carbamazepine to powdered activated carbon (PAC) was confirmed by a series of adsorption tests. In contrast, adsorption of these micropollutants to the sludge was negligible. The removal of these compounds in membrane bioreactor (MBR) was dependent on their hydrophobicity and loading as well as the PAC dosage. Sulfamethoxazole exhibited better removal rate during operation under no or low (0.1 g/L) PAC dosage. When the PAC concentration in MBR was raised to 1.0 g/L, a sustainable and significantly improved performance in the removal of both compounds was observed – the removal efficiencies of sulfamethoxazole and carbamazepine …


Investigation Of Electrical Transport In Hydrogenated Multiwalled Carbon Nanotubes, Adam L. Friedman, Hyunkyung Chun, Don Heiman, Yung Joon Jung, Latika Menon Apr 2012

Investigation Of Electrical Transport In Hydrogenated Multiwalled Carbon Nanotubes, Adam L. Friedman, Hyunkyung Chun, Don Heiman, Yung Joon Jung, Latika Menon

Donald Heiman

Highly disordered multiwalled carbon nanotubes of large outer diameter (~60 nm) fabricated by means of chemical vapor deposition process inside porous alumina templates exhibit ferromagnetism when annealed in a H2/Ar atmosphere. In the presence of an applied magnetic field, there is a transition from positive to negative magnetoresistance. The transition may be explained in terms of the Bright model for ordered and disordered carbon structures. Additionally, temperature dependent electrical transport experiments exhibit a zero-bias anomaly at low temperature.


Influence Of Shielding Gas On Fume Formation Rate For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel, Kristin R. Carpenter, Brian J. Monaghan, John Norrish Jan 2012

Influence Of Shielding Gas On Fume Formation Rate For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel, Kristin R. Carpenter, Brian J. Monaghan, John Norrish

Brian Monaghan

Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). The present paper compares thirteen shielding gases and their impact on FFR in spray transfer. In Ar-based mixtures, increasing CO2 had a greater impact than raising O2 on FFR. When O2 was increased in ternary mixtures, the FFR increased for Ar-5%CO2 but no discernable increase was observed for the Ar-12%CO2 mixtures. Ar-He-CO2 mixtures had the most stable FFR's. The FFR for 100% CO2 was significantly higher due to the change in weld transfer mode to …


Analysis Of Fume Formation Rate And Fume Particle Composition For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel Using Different Shielding Gas Compositions, Kristin R. Carpenter, Brian J. Monaghan, John Norrish Jan 2012

Analysis Of Fume Formation Rate And Fume Particle Composition For Gas Metal Arc Welding (Gmaw) Of Plain Carbon Steel Using Different Shielding Gas Compositions, Kristin R. Carpenter, Brian J. Monaghan, John Norrish

Brian Monaghan

The present paper compares thirteen shielding gases and their impact on FFR and fume particle while welding in the spray transfer regime. There was no obvious influence from the shielding gas on particle composition and fume particles were identified as (Fe,Mn)3O4. There was a slight peak shift that indicated that small levels of Mn, as detected by TEM-EDS, substituted for Fe in the Fe3O4 phase. Shielding gas composition is an important parameter for successful gas metal arc welding (GMAW) and has been shown to affect the fume formation rate (FFR). In Ar-based mixtures, increasing CO2 had a greater impact than …


Investigation Of Electrical Transport In Hydrogenated Multiwalled Carbon Nanotubes, Adam L. Friedman, Hyunkyung Chun, Don Heiman, Yung Joon Jung, Latika Menon Jun 2011

Investigation Of Electrical Transport In Hydrogenated Multiwalled Carbon Nanotubes, Adam L. Friedman, Hyunkyung Chun, Don Heiman, Yung Joon Jung, Latika Menon

Yung Joon Jung

Highly disordered multiwalled carbon nanotubes of large outer diameter (~60 nm) fabricated by means of chemical vapor deposition process inside porous alumina templates exhibit ferromagnetism when annealed in a H2/Ar atmosphere. In the presence of an applied magnetic field, there is a transition from positive to negative magnetoresistance. The transition may be explained in terms of the Bright model for ordered and disordered carbon structures. Additionally, temperature dependent electrical transport experiments exhibit a zero-bias anomaly at low temperature.


Improving The Adsorption Of Heavy Metals From Water Using Commercial Carbons Modified With Egg Shell Wastes, Alejandro Guijarro-Aldaco, Virginia Hernandez-Montoya, Adrian Bonilla-Petriciolet, Miguel A. Montes-Moran, Didilia I. Mendoza-Castillo Jan 2011

Improving The Adsorption Of Heavy Metals From Water Using Commercial Carbons Modified With Egg Shell Wastes, Alejandro Guijarro-Aldaco, Virginia Hernandez-Montoya, Adrian Bonilla-Petriciolet, Miguel A. Montes-Moran, Didilia I. Mendoza-Castillo

Adrian Bonilla-Petriciolet

We introduce the application of hen egg shell waste to improve the adsorption capacities of heavy-metal ions using commercial carbons via the modification of their surface chemistry. Specifically, a calcium solution extracted from egg shell waste has been used as a low-cost activation agent to improve the adsorption properties of three commercial carbons. An orthogonal array of the Taguchi method has been applied to identify the optimal conditions for the adsorbent modification process using the Zn batch adsorption, at 30 °C and pH 5, as the response variable. Our results show that maximum adsorption capacities of Cd, Ni, and Zn …


Co-Generation Of C2 Hydrocarbons And Synthesis Gases From Methane And Carbon Dioxide: A Thermodynamic Analysis, Istadi Istadi, Nor Aishah Saidina Amin Aug 2005

Co-Generation Of C2 Hydrocarbons And Synthesis Gases From Methane And Carbon Dioxide: A Thermodynamic Analysis, Istadi Istadi, Nor Aishah Saidina Amin

Istadi

This paper deals with thermodynamic chemical equilibrium analysis using the method of direct minimization of Gibbs free energy for all possible CH4 and CO2 reactions. The effects of CO2/CH4 feed ratio, reaction temperature, and system pressure on equilibrium composition, conversion, selectivity and yield were studied. In addition, carbon and no carbon formation regions were also considered at various reaction temperatures and CO2/CH4 feed ratios in the reaction system at equilibrium. It was found that the reaction temperature above 1100 K and CO2/CH4 ratio=1 were favourable for synthesis gas production with H2/CO ratio unity, while carbon dioxide oxidative coupling of methane …