bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on NOx Emission Aftertreatment of Lean Burn Gasoline Engine Using Adsorber Reduction Catalyst
Authors: Ye Zhengmao , Li Zhijun , Mohamadian Habib
Published: June 2009

A novel catalyst converter system has been developed for NOx emission aftertreatment of lean burn gasoline engines. The goal is to investigate its impact on emission characteristic and Break Specific Fuel Consumption (BSFC) across a wide range of engine speed and load operating regions, subject to several arrangement schemes for this catalyst converter. It has been indicated from experimental results that the upstream placement of TWC (Three Way Catalyst) ahead of the NOx Adsorber Catalyst is the best solution, which gives rise to the highest converting efficiency to reduce the NOx emission level of the lean burn gasoline engine. The effects of engine speed on exhaust emissions and BSFC are also reflected by operating time of lean mode and rich mode as well as the time ratio between the two using adsorber-reduction catalyst converters. Engine load is in fact the major factor in affecting exhaust characteristics and BSFC of lean burn engines.
Modeling of Formaldehyde Formation From Crevices in a Large Bore Natural Gas Engine
Authors: Olsen Daniel B. , Palmer Ryan K. , Mitchell Charles E.
Published: June 2009

Formaldehyde emissions from stationary natural gas engines are regulated in the United States, as mandated by the 1990 Clean Air Act Amendments. This work aims to advance the understanding of formaldehyde formation in large bore (>36 cm) natural gas engines. Formaldehyde formation in a large bore natural gas engine is modeled utilizing computational fluid dynamics and chemical kinetics. The top land crevice volume is believed to play an important role in the formation mechanisms of engine-out formaldehyde. This work focuses specifically on the top land crevice volume in the Cooper-Bessemer LSVB large bore 4-stroke cycle natural gas engine. Chemical kinetic modeling predicts that the top land crevice volume is responsible for the formation of 22 ppm of engine-out formaldehyde. Based on a raw exhaust concentration of 80 ppm, this constitutes about 27% of engine-out formaldehyde. Simplifying assumptions made for the chemical kinetic modeling are validated using computational fluid dynamics. Computational fluid dynamic analysis provided confirmation of crevice volume mass discharge timing. It also provided detailed pressure, temperature and velocity profiles within the top land crevice volume at various crank angle degrees.
MEMS-Based Gyroscope: Design, Analysis and Simulation
Authors: Sharaf Abdelhameed , Sedky Sherif , Ashour Mahmoud A. , Habib S. E.-D.
Published: June 2009

This paper introduces an efficient design for a symmetrical and decoupled micromachined gyroscope. The angular rate resolution of the gyroscope is increased by matching the resonance frequencies of the drive and sense modes close to each other using symmetric suspensions; whereas, the undesired mechanical coupling between the two modes during matched mode operation is reduced by the fully decoupled gyroscope flexures. Reduced mechanical coupling results in a stable zero-rate output, providing excellent bias stability. The design utilizes efficiently the silicon area, increases the driving electrostatic force, and increases the sensing capacitance.
Characterization of (Bi0.25Sb0.75)2Te3 Deposited by Pulsed Laser Deposition
Authors: Kamal Ahmed , Bakr Hassan Abu , Wang Ziyang , El Samman H. , Fiorini Paolo , Sedky Sherif
Published: June 2009

The main objective of this work is to investigate the possibility of preparing bismuth telluride thin films using pulsed laser deposition. The effect of varying the deposition pressure, laser fluence, and the deposition temperature on the surface roughness, film composition, grain microstructure and electrical resistivity is analyzed using, scanning electron microscopy, atomic force microscopy, X-ray fluorescence, transmission electron microscopy, and four point probe measurements. It is demonstrated that relatively smooth films can be deposited at a laser flounce of 0.6 J/cm2 and using argon as a background gas at 10−1 mbar. On the other hand, resistivities as low as 2 mΩ.cm can be obtained by either depositing the film at 200°C, or by post-laser annealing films deposited at room temperature.
Novel Multifunctional Composites by Functionally Dispersed Carbon Nanotubes Throughout the Matrix of Carbon/Carbon Composites
Authors: Aly-Hassan Mohamed S.
Published: June 2009

Recently, increasing demands for smarter and smaller products calls for the development of multifunctional composites. These materials are used not only as structural materials but also satisfy the needs for additional functionalities such as thermal, electrical, magnetic, optical, chemical, biological, etc. In this research, a novel carbon nanotubes dispersion approach leads to a new generation of multifunctional composites with additionally novel thermal functionality, we called it heat-directed functionality. These distinctive composites have unique capability which can conduct the majority of the transferred heat by conduction to the preferred area or direction of the thermal structure. This unique heat-directed property can be attained by varying the in-plane thermal conductivity. Varying the in-plane thermal conductivity of the composites functionally is achieved by dispersing highly heat-conductive materials such as carbon nanotubes throughout the matrix functionally, not uniformly. Therefore, in this research three phase carbon/carbon composites have been fabricated with functionally dispersed carbon nanotubes throughout the carbon matrix of continuously plain woven carbon fiber fabrics in order to attain this useful property. The fabricated heat-directed carbon/carbon composites have been examined experimentally and numerically. The in-situ full-field infrared measurements and finite element analysis of the designed composites showed that the heat transfer direction can be substantially controlled by just functionally dispersed a few percentages of carbon nanotubes through the matrix of traditional long carbon fiber-reinforced carbon matrix composites. This exceptional property can play a significant performance improvement in heat transfer process along the in-plane of the materials as well as helping to decrease the heating up of the Earth, global warming, due to the escaped heat of many engineering applications. In other words, the efficient heat energy management or heat energy saving via using the introduced multifunctional carbon/carbon composites with heat-directed functionality can significantly help with both sides of the equation of efficient energy consumption and friendly-environment applications.
Effect of Nanostructured Thermal Spray Coatings on Fatigue Behavior of Low-Carbon Steel
Authors: Ibrahim Ahmed , Berndt Christopher C.
Published: June 2009

Nanostructured and conventional titania (TiO2) coatings were thermally sprayed using air plasma spray (APS) and high velocity oxy-fuel (HVOF) processes. The fatigue and mechanical properties of these coatings were investigated. The fatigue strength of coatings deposited onto low-carbon steel showed that the nanostructured titania coated specimens exhibited significantly higher fatigue strength compared to the conventionally sprayed titania. SEM analysis of fracture surfaces revealed valuable information regarding the influence of these coatings on the performance of the coated component. Analysis of surface deformation around Vickers indentations was carried out. This investigation gives new understanding to the nature of fatigue and deformation of these coatings.
Production of Polymer Nanofibers by Wet Spinning
Authors: El-Ashry Mostafa M. , Gouda Kareem M. , Young Henry Daniel
Published: June 2009

Polymer nanofibers are attractive in many engineering and medical applications because of its distinctive mechanical, chemical, and electrical properties typically evident in nanomaterials. Some applications are liquid & particle filters, composites, surgical masks, sensors. We propose a fibre fabrication method that can produce continuous polymer nanofibres with submicron cross-section. This technique can spin fibres from precursor rheologies that would be considered “unspinnable” by any other current method. As such, this technique may allow the fabrication of novel fibre structures, assist in the fabrication of nanofibers from new materials, and allow the use of novel chemical routes in fibre spinning.
Fabrication and Properties of Nylon-6/Layered Silicate Nanocomposites by Melt Blending
Authors: Awad Walid , Esawi Amal , Ramadan Adham
Published: June 2009

Polymer/clay nanocomposites currently attract immense interest from both research and industrial communities. By dispersing at the molecular level a tiny amount of clay within a polymeric matrix, a wide range of properties can be significantly improved. The efficiency of the clay (layered silicate) in improving the properties of the polymer materials is primarily determined by the degree of its dispersion in the polymer matrix. To promote the molecular and stable dispersion of the clay layers, the clays should be organically-modified with onium salts. In this work, nylon-6 nanocomposites based on two types of commercial organoclays were prepared by melt blending via single-screw extrusion. The good dispersion of clay in the nylon-6 nanocomposites was confirmed by X-ray diffraction and transmission electron microscopy. The influence of the dispersed nano-clay fillers on the thermal and mechanical properties of the resulting nanocomposites was characterized using thermogravimetric analysis and nanoindentation.
Measurement of DNA Hybridization by Nano-Deformation of Microcantilever in CMOS Biosensor
Authors: Yang S. M. , Yin T. I. , Chang C.
Published: June 2009

A 1 cm × 1 cm biosensor chip for analyzing DNA hybridization is developed by CMOS process. The sensor chip has 6 measurement regions, each region with 3 pairs of parallel microcantilever of 125 × 60 × 0.75μm. The microcantilever is a 4-layer structure composed of an immobilized surface layer, a top insulation layer, an embedded piezoresistive layer, and a bottom insulation layer to measure the nano-deformation induced by the surface-assemble monolayer of alkanethiols on Au. By the Langmuir adsorption model, the estimated adsorption rate of the ssDNA is 0.005sec−1. The design has intrinsic sensitivity needed in biochemical applications such as detecting nucleotide polymorphism and single base mutation to sequence DNA. The capability of in-situ, multipoint measurement promise many frontiers to be explored.
Synthesis and Characterization of New Cast A356(Al2O3)P Metal Matrix Nano-Composites
Authors: El-Mahallawi I. S. , Eigenfeld K. , Kouta F. H. , Hussein A. , Mahmoud T. S. , Ragaie R. M. , Shash A. Y. , Abou-Al-Hassan W.
Published: June 2009

The present investigation studies the processing of A356 Al-Si alloy containing up to 5% vol.-% nano-sized al2o3 particles having size less than 500 nm. Composites were prepared using semi-solid casting route. To evaluate the results the alloys were further characterised by various metallurgical and mechanical characterization methods. The results showed that introducing nano-particles into semi-solid slurries promises to be a successful route for producing a new generation of cast metal matrix nano-composites (MMNCs). The nano-composites showed high strength values associated with superior ductility, low porosity content, high corrosion resistance, and improved electrical conductivity compared to the alloy without particles addition under the same casting conditions.
Tensile and Shear Properties of Biaxial Flat Braided Carbon/Epoxy Composites With Dispersed Carbon Nanofibers in the Matrix
Authors: Aly-Hassan Mohamed S. , Kobayashi Yuka , Nakai Asami , Hamada Hiroyuki
Published: June 2009

In laminated flat braided composites there are no fibers through the thickness direction except at the edges due to the fiber continuity of the braiding technique. A delamination along the interlaminar planes can be propagated because of the lack of fibers in the Z- or third-direction to the composite. The delamination initiates essentially as a result of arising the stresses concentrations around the transverse or matrix cracks that appear due to the mismatch of the thermal expansion coefficients of the fibers and matrix during the fabrication process. The delamination renders low interlaminar composite properties and represents a fundamental weakness of laminated flat braided composites especially with increasing the braiding angle, and thus minimizes the shear stress transfer. In this research, laminated flat braided carbon fabrics were performed via flattening tubular braided fabrics with braiding angle of ±45° by applying carefully compressive loads laterally on the tubular fabrics. Then, carbon fiber reinforced epoxy matrix composites were fabricated from the above-mentioned biaxial fabrics with and without uniformly dispersed carbon nanofibers throughout the epoxy matrix. Three loading percentages of carbon nanofibers (specifically, 0.5, 1, and 2 wt%) were dispersed in the matrix of the composites to enhance the matrix and interlaminar/inter-ply properties. The influence of matrix and interlaminar properties improvements on the in-plane tensile and shear response of the laminated flat braided composites was clarified via conducting of ±45° laminates tensile tests. The experimental results of tensile tests revealed that the tensile and in-plane shear properties as well as the fracture behavior of the composites are substantially influenced by the incorporation of the dispersed carbon nanofibers in the matrix of the composites. A pulsed thermography technique was used to inspect the occurrence of the delamination after the fracture under tensile loadings. The thermal wave image and logarithmic temperature-time curves of the pulsed thermography inspection illustrated that the composites with dispersed carbon nanofibers rendered higher interlaminar properties than that of composites without nanofibers. The main conclusion of this research can be summarized that dispersion of carbon nanofibers through the epoxy matrix of laminated flat braided composites is not only enhanced the matrix properties but also improved the interphase morphology between the composite plies that maximized the stress transfer of the composites. In other words, the fabricated braided composites with braiding angle of ±45° are predominantly by both of matrix and interlaminar properties.
Effect of the Compaction Parameters and Canning Material of Nanostructured Al-Powder Consolidated via Intense Plastic Straining Process
Authors: Salem H. G. , Shamma M.
Published: June 2009

Research groups around the world have reached common and contradicting conclusions regarding the behavior and properties of nanostructured materials. The aim of this research is to affirm the common findings by previous research, and support one of the currently proposed concepts of mechanical behavior based on processing and characterization of consolidated nanocrystalline micropowders of high strength/precipitation hardenable aluminum alloy using combined PM/intense plastic straining via Equal Channel angular Extrusion (ECAE). This research work investigated the effect of (a) Cold and hot consolidation of nanocrystalline Al-2124 micropowders into compacts with 4.0 h/d ratio and (b) Canning material used for encapsulating the compact rods for subsequent extrusion within the ECAE channels, and (c) the effect of ECAE number of passes and routes on the green compact properties. The effect of the processing parameters (compaction condition, extrusion temperature, strain rate) on the sample density, grain, subgrain and subcell sizes, and hardness was studied. Pure wrought and cast Cu, and casts Al-cans as well as Al-2024 wrought cans were used for canning of the consolidated powders. Green and hot compact rods were produced from 40μm average particle size Al-2124 powders with 53nm internal structure. Highest density consolidated rods were produced for the double sided cold compaction at 6σ (450MPa) over duration of 30min, while single sided compaction at similar pressure over 60min duration time of compaction and at temperature of 480°C produced the most dense and highest hardness hot compacts. Pure wrought Cu and cast Al are the most suitable canning material for room temperature ECAE of the Al-2124 green compacts. Non-isothermal heating during extrusion hindered the uniform warm deformation of the green and hot compacts canned in wrought Al-2024. Loose powder particles of the green compacts results in particle rotation while passing though the 90° angle intersecting channels of ECAE, and hence prevents full consolidation and densification of the produced product.
Facile Synthesis of Mesoporous Silica Nanotubes With Amide Type Surfactant
Authors: Han Sang-Cheol , Choi Kwang-Min , Park Sang-Eon
Published: June 2009

Novel synthetic method for the formation of mesoporous silica nanotubes was proposed using glycyldodecylamide (GDA) as an amino acid surfactant, which enabled to control the tube diameter, wall structure and morphology with the diverse structures of amphiphile due to the capability of H-bonds by forming amide bond. Moreover, this sol-gel transcription process could be elucidated at neutral condition that enabled the recyclable use of surfactant and resulted in unique structures depending on the temperatures of self-assembly.
CVD Nano-Crystalline Tin Oxide Coatings on Glass Substrate: The Effect of Substrate Temperature
Authors: Karsliog˘lu Ramazan , Akbulut Hatem , Alp Ahmet
Published: June 2009

Tin oxide thin films were grown by chemical vapor deposition (CVD) on glass substrates at atmospheric pressure (AP) and different temperatures of 400, 500 and 600 °C. The deposition times were also altered from 15 to 60 minutes with 15 minutes time intervals to investigate the effect of deposition time. A horizontal home-made reactor was used for the deposition from SnCl2 precursors with flowing pure oxygen at a rate 5 ccpm. The structure was analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM) and atomic force microscopy (AFM) facilities to reveal the deposition mechanisms and crystalline structures. Energy-dispersive spectroscopy (EDS) was conducted to understand the elemental surface composition of the thin films produced. It was detected that the morphology and the oxide structure were changed with deposition time and temperature. The optical and electrical properties were also studied to reveal a relationship between physical properties and production parameters of the resultant thin films.
Conversion Technologies: The Challenges for the MARTIN Reverse-Acting Grate System
Authors: Koralewska Ralf
Published: June 2009

Thermal treatment of waste differs significantly from the combustion of regular fuels due to the fluctuating and unpredictable composition of the fuel. It is therefore necessary to develop processes with safe process engineering technology that guarantee the treatment of waste in accordance with ecological and economic constraints in addition to complying with international legal requirements. Various important factors have to be considered: not only the reduction of the volume and mass of waste and the destruction and separation of pollutants, but also the efficient energy production (electricity and district heating) and the guaranteed treatment of all waste. In order to comply with strict Japanese regulatory policies, particularly with regard to residue quality and overall output of organic substances, grate technology was modified by means of downstream melting processes that are intensive in terms of maintenance, energy and resulting costs. While vitrification of bottom ash and fly ash does improve quality and provide additional recycling possibilities, it has not proven sustainable. Conversion technologies using separated high-temperature processes make integrated production of granulated slag possible. Large market shares in Japan were gained as a result. However, practical experience in largescale plants has shown serious drawbacks with regard to availability, profitability and process safety. The use of alternative waste conversion technologies failed on the German market due to massive technical problems and considerable financial losses for all those involved.
Dry Ash Collection at Coal Fired Power Plants and Potential for WTE Facilities
Authors: Cianci Vincenzo , Coppola Daniele , Sunk Werner
Published: June 2009

Remarkable environmental and economical benefits derive from an innovative technology for dry bottom ash removal from coal-fired power plants that may be applied at WTE facilities combusting unprocessed MSW or RDF. This paper describes the MAC system technology that offers a very reliable and broadly proved solution for dry bottom ash collection and handling. Up to now the MAC system has been installed widely and successfully at coal-fired power stations. However, because of the flexibility of the MAC dry ash collector and the wide experience of MAGALDI GROUP in conveying solid bulk materials, this system is ready to be tested for the collection of bottom ash from WTE boilers.
Pioneer Plus™: The Next Generation of Mass Burn Combustors
Authors: Champagne Edward P.
Published: June 2009

Two of Energy Answers Corporation’s (EnergyAnswers) waste-to-energy (WTE) facilities utilize mass burn stepped hearth refractory combustors. Three 120 ton per day (TPD) units are located at the Pittsfield (MA) Resource Recovery Facility and three 136 TPD units are at the Pioneer Valley Resource Recovery Facility in Agawam, MA. EnergyAnswers has over 20 years operating experience with these mass burn units which are known for their rugged construction and dependable operation. Over the past several years, EnergyAnswers operating personnel have developed and installed numerous improvements which have reduced residual carbon in the ash, lowered operating and maintenance (O&M) costs, and increased steam generation and throughput. The following highlights the numerous improvements that have resulted in a new generation of mass burn combustor called Pioneer Plus™: • Improved tracking and alignment of the ash transfer ram carriages for reduced air infiltration and jamming, • Utilization of poured and sprayed refractories for lower O&M costs, • Improved control of under-fire air to improve burn out and steam rate while maintaining throughput, • Better sealing to reduce air in-leakage and ash accumulation. The above improvements have been implemented on several of the combustors at the EnergyAnswers facilities. Additional improvements have been identified and will be incorporated into the design of new Pioneer Plus™ plants in the coming years.
MSW Contingency Planning: Opportunities for Perham Facility Expansion
Authors: Traeger David , Clark Matt , Louiseau Robert
Published: June 2009

The Perham Resource Recovery Facility (PRRF) in Perham, Minnesota receives and processes Municipal Solid Waste (MSW) from Otter Tail, Todd, Wadena and Stearns Counties. Combustion of the MSW provides the generation of steam for sale to two local industries. Under the terms of these steam sales agreements, the PRRF supplies the base load and peak steam required by these industries from a MSW boiler and/or a natural gas-fired auxiliary boiler. The City of Fergus Falls, Minnesota until recently operated the Fergus Falls Waste-to-Energy (WTE) plant. This facility received municipal solid waste (MSW) from Otter Tail and Grant County. The facility generated steam for use in the State Hospital, however, the State of Minnesota has decided to shut down the hospital and will no longer need the steam. As a result, on February 28, 2006, the Fergus Falls plant shut down. HDR Engineering, Inc. (HDR) working with the City of Perham and the participating counties, conducted a study to consider cooperative disposal of the waste currently processed in Fergus Falls. Three of the options considered included expansion of the PRRF. These options included salvaging of portions of the Fergus Falls WTE plant and providing pre-combustion processing of the waste to recover recyclables in order to maximize the Perham plant capacity. This paper describes the options and the conclusions of the investigations.
Analysis of Boiler Fouling and Boiler Cleaning Methods at the Commerce Refuse-to-Energy Facility
Authors: Eaton Matthew A.
Published: June 2009

Waste-to-energy boiler fire-side fouling is a major operational issue for many facilities, including the Commerce Refuse-to-Energy Facility. The Commerce Refuse-to-Energy Facility is a 350 ton per day, mass burn waterwall facility that began operation in 1987. Fouling occurs throughout the convection sections with the highest differential pressure occurring across the generating bank. Flue gas differential pressures and temperatures have been tracked and analyzed at the facility for approximately ten years during various operating conditions. It has been determined that the rate of increase of the differential pressure across the generating bank is correlated with flue gas temperature and the extent of fouling. Several different cleaning methods have been used to clear the convection zone of ash deposits, including off-line hydroblasting, on-line hydroblasting, on-line explosives cleaning, sootblowers and sonic horns. Better understanding of the fouling trends and evaluation of cleaning methods has led the facility to use a combination of on-line hydroblasting and explosives cleaning and off-line hydroblasting. The facility is now able to operate one year between planned outages, compared to ten weeks during the initial operation of the facility. Additional savings have also been achieved by reducing induced draft fan load, and possibly a reduction in tube wastage.
York Resource Recovery Center Metal Spray Success
Authors: Salsbury Edward
Published: June 2009

Early US waste-to-energy plants were constructed using conventional boilers designed for fossil fuels, gas, and oil. Combusting MSW exposed those boilers to high levels of sulfides and chlorides that caused accelerated corrosion problems. MSW fuel required higher amounts of excess air that resulted in high furnace gas velocities and metal erosion. Depending upon the individual design of each boiler, effects of higher upper furnace temperature, flame impingement, and flyash carry over were reported. This paper describes a test conducted to extend the useful metal life of superheater tubes by employing recently developed high velocity continuous combustion (HVCC) metal spray materials.
Implementing and Managing a Practical Corporate Wide Legionella Risk Reduction Strategy for Industrial Water Systems
Authors: Myers Eric R. , Lehr Jay
Published: June 2009

Experts believe that Legionella may be present in 25% of cooling towers at any time, even with normal water treatment programs in place. This could pose a risk to employees and others working near cooling towers, and it could pose a risk to neighboring facilities such as schools, hospitals, public facilities, other businesses, or residential communities. The goal is to reduce the risk of Legionella, more specifically Legionella pnuemophila, which is the bacterium that causes a potentially fatal pneumonia known as Legionenaires’ Disease or legionellosis. Reducing the risk of Legionella requires more than water treatment alone, it requires a strategic plan based on recommended industry best practices that considers the mechanical, operational, and chemical control of cooling water systems. Implementing a corporate wide policy for Legionella risk reduction is challenging for waste-to-energy facility cooling towers. While a corporate policy for managing the risk due to Legionella is prudent, application of such a policy should not be wholly applied across all facilities or plant locations because not all water systems are equal or operated the same. Implementation starts with a plan that involves a multidisciplinary team including third party consultation and expertise. The first step of the Legionella risk reduction strategy is to evaluate current equipment and practices at each plant through a risk assessment process. The second step is to prepare a written Management Plan based on the risk assessment that clearly details risk reduction practices. The third step is to implement the management plan and monitor the system to ensure practices remain effective. And finally, all documentation should be periodically reviewed and adjustments made as necessary. This presentation will describe a process for implementing a corporate Legionella risk reduction policy, and it will highlight some of the major experiences learned.
Investigation of Thermo-Gravimetric Analysis (TGA) on Waste Tires and Chemical Analysis Including Light Hydrocarbons, Substituted Aromatics, and Polycyclic Aromatic Hydrocarbon (PAH)
Authors: Kwon Eilhann , Castaldi Marco J.
Published: June 2009

This investigation has been initiated to characterize the thermal decomposition of waste tires with Thermo-Gravimetric Analysis (TGA) in various atmospheres ranging in oxygen content; 100% N2, 7%, 21% (air) and 30% O2. Chemical analysis focusing on light hydrocarbons, substituted aromatics, and polycyclic aromatic hydrocarbon has been done qualitatively and quantitatively to understand the mechanism of thermal degradation of scrap tires and hazardous air pollutants such as PAH. The release of chemicals from scrap tires has been determined experimentally using Gas Chromatography/Mass Spectroscopy (GC/MS) coupled to TGA unit. The identities and absolute concentrations of over 50 major and minor species have been established. Significant volatile organic carbons (VOC) including substituted aromatics and PAH were observed between 300°C and 500°C. In addition, significant black carbon residual was observed in most environments except air and oxygen enhanced atmospheres and suggested not only the potential recovery of black carbon out of feedstock, but also the possibility of combined thermal treatment between combustion and gasification. These measurements supply information on the identities and levels of hazardous air pollutants, and provide useful new data for the development and validation of detailed reaction mechanisms describing their origin and fate. Finally, while high contents of VOC show significant potential to be utilized as an unconventional solid fuel, they also tend to generate hazardous pollutants.
WTERT: May 2006–May 2007 Highlights
Authors: Themelis Nickolas J.
Published: June 2009

The Waste-To-Energy Research and Technology Council (WTERT) was co-founded in May 2002 by the Earth Engineering Center of Columbia University (EEC) and Integrated Waste Services Association (IWSA). Its mission is to direct academic research on various aspects of energy and materials recovery from municipal and other solid wastes and disseminate the findings of its research to professionals and the public. WTERT is a non-profit organization that relies heavily on faculty and graduate students who are studying various aspects of integrated waste management and waste-to-energy. The main products of WTERT research are the theses, technical publications and presentations made during the year. In all there were 14 publications, 22 presentations, and 12 posters presented by WTERT faculty and graduate students at different technical meetings and public forums. This report presents the highlights of the WTERT activities since NAWTEC 14.
Determination of Composition of Cellulose and Lignin Mixtures Using Thermo Gravimetric Analysis (TGA)
Authors: Singh Kaushlendra , Risse Mark , Das K. C. , Worley John
Published: June 2009

The proportional composition of cellulose, hemicellulose, lignin and minerals in a biomass plays a significant role in the proportion of pyrolysis products (bio-oil, char, and gases). Traditionally, the composition of biomass is chemically determined, which is a time consuming process. This paper presents the results of a preliminary investigation of a method using thermo-gravimetric analysis for predicting the fraction of cellulose and lignin in lignin-cellulose mixtures. The concept is based on a newly developed theory of Pyrolytic Unit Thermographs (PUT). The Pyrolytic Unit Thermograph (PUT) is a thermograph showing rate of change of biomass weight with respect to temperature for a unit weight loss. These PUTs were used as input for two predictive mathematical procedures that minimize noise to predict the fractional composition in unknown lignin-cellulose mixtures. The first model used linear correlations between cellulose/lignin content and peak decomposition rate while the second method used a system of linear equations. Results showed that both models predicted the composition of lignin-cellulose mixture within 7 to 18% of measured value. The promising results of this preliminary study will certainly motivate further refinement of this method through advanced research.
EXTRA NEUTRAL GAUGE BOSON FROM THE 3-3-1 MODEL AND THE SPIN CORRECTION OF TOP QUARK PAIR PRODUCTION AT THE ILC
Authors: LIU YAO-BEI , WANG XUE-LEI
Published: June 2009

In the off-diagonal basis, we explore the effects of extra neutral gauge boson Z' predicted in two versions of SU (3)C × SU (3)L × U (1)X model on the spin configuration of the top quark pair production in the high energy linear e+e- collider (ILC). Our numerical results show that, the cross sections for the suppressed spin configurations can be enhanced with the effects of the Z' boson through the modification of the spin configuration by producing enough top quark pairs to be measured in the future ILC experiments, which provides the way to observe the effects of Z' predicted in the 3-3-1 model and discriminate the various versions of 3-3-1 model.
EFFECTS OF HEAVY BOSONIC EXCITATIONS ON QED VACUUM
Authors: ARIAS PAOLA , GAMBOA JORGE , FALOMIR HORACIO , MÉNDEZ FERNANDO
Published: June 2009

We discuss the contribution of axion-like excitations (ALE) to the vacuum birefringence in the limit mA ≳ ω, where mA is the mass of the excitation and ω the energy of test photons interacting with an external (intense) magnetic field. The relevance of this term with respect to the QED contribution depends on the ratio gA/mA and, from present bounds on the mass and the coupling constant gA, we find that in the present low energy regime, it ranges from 10-14 to 102 suggesting an interesting alternative to explore.
MOTION OF MASSIVE AND MASSLESS TEST PARTICLES IN DYADOSPHERE GEOMETRY
Authors: RAYCHAUDHURI B. , RAHAMAN F. , KALAM M. , GHOSH A.
Published: June 2009

Motion of massive and massless test particle in equilibrium and nonequilibrium case is discussed in a dyadosphere geometry through Hamilton–Jacobi method. Scalar wave equation for massless particle is analyzed to show the absence of superradiance in the case of dyadosphere geometry.
Learning and Macroeconomics
Authors: Evans George W. , Honkapohja Seppo
Published: June 2009

Expectations play a central role in modern macroeconomic theories. The econometric learning approach models economic agents as forming expectations by estimating and updating forecasting models in real time. The learning approach provides a stability test for rational expectations and a selection criterion in models with multiple equilibria. In addition, learning provides new dynamics if older data are discounted, if models are misspecified, or if agents choose between competing models. This paper describes the expectational stability (E-stability) principle and the stochastic approximation tools used to assess equilibria under learning. Applications of learning to a number of areas are reviewed, including the design of monetary and fiscal policy, business cycles, self-fulfilling prophecies, hyperinflation, liquidity traps, and asset prices.
A Behavioral Account of the Labor Market: The Role of Fairness Concerns
Authors: Fehr Ernst , Goette Lorenz , Zehnder Christian
Published: June 2009

In this paper, we argue that important labor market phenomena can be better understood if one takes (a) the inherent incompleteness and relational nature of most employment contracts and (b) the existence of reference-dependent fairness concerns among a substantial share of the population into account. Theory shows and experiments confirm that, even if fairness concerns were to exert only weak effects in one-shot interactions, repeated interactions greatly magnify the relevance of such concerns on economic outcomes. We also review evidence from laboratory and field experiments examining the role of wages and fairness on effort, derive predictions from our approach for entry-level wages and incumbent workers' wages, confront these predictions with the evidence, and show that reference-dependent fairness concerns may have important consequences for the effects of economic policies such as minimum wage laws.
Improving Education in the Developing World: What Have We Learned from Randomized Evaluations?
Authors: Kremer Michael , Holla Alaka
Published: June 2009

Across a range of contexts, reductions in education costs and provision of subsidies can boost school participation, often dramatically. Decisions to attend school seem subject to peer effects and time-inconsistent preferences. Merit scholarships, school health programs, and information about returns to education can all cost-effectively spur school participation. However, distortions in education systems, such as weak teacher incentives and elite-oriented curricula, undermine learning in school and much of the impact of increasing existing educational spending. Pedagogical innovations designed to address these distortions (such as technology-assisted instruction, remedial education, and tracking by achievement) can raise test scores at a low cost. Merely informing parents about school conditions seems insufficient to improve teacher incentives, and evidence on merit pay is mixed, but hiring teachers locally on short-term contracts can save money and improve educational outcomes. School vouchers can cost-effectively increase both school participation and learning.
Some Developments in Economic Theory Since 1940: An Eyewitness Account
Authors: Arrow Kenneth J.
Published: June 2009

Any psychologist who has studied eyewitness accounts knows first of all how unreliable they are. I therefore submit this informal account of some developments in economic theory without research, just as a set of recollections. It is also not an autobiography, nor a systematic account of my own work. Rather, I consider primarily those developments in economic theory that have had both general interest in the field and special concern for me. For example, as social choice theory is still a specialized field, I am not going to discuss it at all. Further, as it has turned out, I emphasize the developments of technique, although to some extent I refer to some of the underlying visions of the economy to which they are applied. To evaluate my eyewitness testimony, I give the reader some idea of my background and, in particular, the path that led me to be an economist and that has influenced my work and my perception of the development of economics in general. (As my friend Paul David keeps on reminding me and the rest of the world, all development is path-dependent.) I then follow up with four major aspects of economic research in the last 60 years, the period of my scholarly activity. One, econometric methodology and practice, is of such fundamental importance that it cannot go unnoticed, although I played no role in it. With the other three, general equilibrium, dynamic processes, and uncertainty and information, I was more intimately involved.
A New 4‐Point C3 Quaternary Approximating Subdivision Scheme
Authors: Mustafa Ghulam , Khan Faheem
Published: June 2009

A new 4‐point C3 quaternary approximating subdivision scheme with one shape parameter is proposed and analyzed. Its smoothness and approximation order are higher but support is smaller in comparison with the existing binary and ternary 4‐point subdivision schemes.
Inflammatory Profile of Awake Function-Controlled Craniotomy and Craniotomy under General Anesthesia
Authors: Klimek Markus , Hol Jaap W. , Wens Stephan , Heijmans-Antonissen Claudia , Niehof Sjoerd , Vincent Arnaud J. , Klein Jan , Zijlstra Freek J.
Published: June 2009

Background. Surgical stress triggers an inflammatory response and releases mediators into human plasma such as interleukins (ILs). Awake craniotomy and craniotomy performed under general anesthesia may be associated with different levels of stress. Our aim was to investigate whether those procedures cause different inflammatory responses.Methods. Twenty patients undergoing craniotomy under general anesthesia and 20 patients undergoing awake function-controlled craniotomy were included in this prospective, observational, two-armed study. Circulating levels of IL-6, IL-8, and IL-10 were determined pre-, peri-, and postoperatively in both patient groups. VAS scores for pain, anxiety, and stress were taken at four moments pre- and postoperatively to evaluate physical pain and mental duress.Results. Plasma IL-6 level significantly increased with time similarly in both groups. No significant plasma IL-8 and IL-10 change was observed in both experimental groups. The VAS pain score was significantly lower in the awake group compared to the anesthesia group at 12 hours postoperative. Postoperative anxiety and stress declined similarly in both groups.Conclusion. This study suggests that awake function-controlled craniotomy does not cause a significantly different inflammatory response than craniotomy performed under general anesthesia. It is also likely that function-controlled craniotomy does not cause a greater emotional challenge than tumor resection under general anesthesia.
Fast and Reliable Mouse Picking Using Graphics Hardware
Authors: Zhao Hanli , Jin Xiaogang , Shen Jianbing , Lu Shufang
Published: June 2009

Mouse picking is the most commonly used intuitive operation to interact with 3D scenes in a variety of 3D graphics applications. High performance for such operation is necessary in order to provide users with fast responses. This paper proposes a fast and reliable mouse picking algorithm using graphics hardware for 3D triangular scenes. Our approach uses a multi‐layer rendering algorithm to perform the picking operation in linear time complexity. The objectspace based ray‐triangle intersection test is implemented in a highly parallelized geometry shader. After applying the hardware‐supported occlusion queries, only a small number of objects (or sub‐objects) are rendered in subsequent layers, which accelerates the picking efficiency. Experimental results demonstrate the high performance of our novel approach. Due to its simplicity, our algorithm can be easily integrated into existing real‐time rendering systems.
How to Efficiently Obtain Human Tissues to Support Specific Biomedical Research Projects
Authors: Bell Walter C. , Sexton Katherine C. , Grizzle William E.
Published: June 2009

The purpose of this article is to facilitate access of biomedical researchers to human tissues by describing the types of tissue resources available to researchers, common problems with tissue requests that may limit tissue availability to specific investigators, and steps that can be taken to simplify requests to avoid these problems and enhance access to tissue. Types of human tissue resources available to investigators are described and reviewed, and the experience of the University of Alabama Tissue Collection and Banking Facility (TCBF) is described. Our experience indicates that typical problems with requests for tissue fall into the following categories: (1) size and number of specimens, (2) type (rarity and availability), (3) time constraints, (4) demand versus supply, (5) limitations and goals of the resource, and (6) time and resources that can be devoted to a specific request. Investigators should review their requests for human tissues to support their research if they are not receiving adequate quantities of tissue. This review is best accomplished by discussing their requests with the tissue resource and correcting specific limitations that block access to the tissues they need. (Cancer Epidemiol Biomarkers Prev 2009;18(6):1676–9)
Effect of Coffee and Green Tea Consumption on the Risk of Liver Cancer: Cohort Analysis by Hepatitis Virus Infection Status
Authors: Inoue Manami , Kurahashi Norie , Iwasaki Motoki , Shimazu Taichi , Tanaka Yasuhito , Mizokami Masashi , Tsugane Shoichiro ,   for the Japan Public Health Center-Based Prospective Study Group
Published: June 2009

In spite of their anticarcinogenic potential, the effect of coffee and green tea consumption on the risk of liver cancer has not been clarified prospectively in consideration of hepatitis C (HCV) and B virus (HBV) infection. We examined whether coffee and green tea consumption was associated with a reduced risk of liver cancer by hepatitis virus infection status in the Japan Public Health Center-Based Prospective Study Cohort II. A total of 18,815 subjects ages 40 to 69 years participating in a questionnaire and health checkup survey in 1993 to 1994 were followed for the incidence of liver cancer through 2006. A total of 110 cases of liver cancer were newly documented. Hazard ratios for coffee and green tea consumption categories were calculated with a Cox proportional hazards model. Compared with almost never drinkers, increased coffee consumption was associated with a reduced risk of liver cancer in all subjects (hazard ratio for <1, 1-2, and ≥3 cups/d; Ptrend = 0.67, 0.49, 0.54, and 0.025). A similar risk tendency was observed in those with either or both HCV and HBV infection. In contrast, no association was observed between green tea consumption and the risk of liver cancer in all subjects. Our results suggest that coffee consumption may reduce the risk of liver cancer regardless of HCV and HBV infection status, whereas green tea may not reduce this risk.(Cancer Epidemiol Biomarkers Prev 2009;18(6):1746–53)
Prediagnosis Reproductive Factors and All-Cause Mortality for Women with Breast Cancer in the Breast Cancer Family Registry
Authors: Phillips Kelly-Anne , Milne Roger L. , West Dee W. , Goodwin Pamela J. , Giles Graham G. , Chang Ellen T. , Figueiredo Jane C. , Friedlander Michael L. , Keegan Theresa H.M. , Glendon Gord , Apicella Carmel , O'Malley Frances P. , Southey Melissa C. , Andrulis Irene L. , John Esther M. , Hopper John L.
Published: June 2009

Studies have examined the prognostic relevance of reproductive factors before breast cancer diagnosis, but most have been small and their overall findings inconclusive. Associations between reproductive risk factors and all-cause mortality after breast cancer diagnosis were assessed with the use of a population-based cohort of 3,107 women of White European ancestry with invasive breast cancer (1,130 from Melbourne and Sydney, Australia; 1,441 from Ontario, Canada; and 536 from Northern California, United States). During follow-up with a median of 8.5 years, 567 deaths occurred. At recruitment, questionnaire data were collected on oral contraceptive use, number of full-term pregnancies, age at first full-term pregnancy, time from last full-term pregnancy to breast cancer diagnosis, breastfeeding, age at menarche, and menopause and menopausal status at breast cancer diagnosis. Hazard ratios for all-cause mortality were estimated with the use of Cox proportional hazards models with and without adjustment for age at diagnosis, study center, education, and body mass index. Compared with nulliparous women, those who had a child up to 2 years, or between 2 and 5 years, before their breast cancer diagnosis were more likely to die. The unadjusted hazard ratio estimates were 2.75 [95% confidence interval (95% CI), 1.98-3.83; P < 0.001] and 2.20 (95% CI, 1.65-2.94; P < 0.001), respectively, and the adjusted estimates were 2.25 (95% CI, 1.59-3.18; P < 0.001) and 1.82 (95% CI, 1.35-2.46; P < 0.001), respectively. When evaluating the prognosis of women recently diagnosed with breast cancer, the time since last full-term pregnancy should be routinely considered along with other established host and tumor prognostic factors, but consideration of other reproductive factors may not be warranted. (Cancer Epidemiol Biomarkers Prev 2009;18(6):1792–7)