bluuebunny/crossref_metadata_2025 huggingface dataset:
Train Horn Noise Impact Assessment Model
Authors: Huang Jade , Warner Jeffery E.
Published: November 2010

Train horn noise has been long regarded as a nuisance to the residents of the adjacent communities, in spite of the fact that train horn is an effective deterrent to accidents at highway-rail grade crossings. Federal, state, and local governments are making efforts in mitigating the negative effect of train horn noise. This paper utilized census data and train speed and volume information to develop a GIS-based model that exhibits the train horn noise impact on adjacent populations and demonstrates how these impacts change with altered rail operations. This model serves as a tool for planners, engineers, and decision-makers to gain a better understanding of the most affected areas, thus pursue the most appropriate mitigation measures for the localities.
Case Studies in Planning Railroad Crew Members
Authors: Martins Joa˜o P. , Morgado Ernesto M.
Published: November 2010

CREWS is a software product for planning and managing the work of rail-staff, providing solutions to one of the core problems that railroad companies face today: effective management of resources. CREWS addresses, in an integrated way, all phases of the planning and management process. This paper reports some results of work in the application of both Artificial Intelligence and Operations Research techniques in planning and managing crew-members (engineers and conductors) in railroad companies. The paper also presents case studies emerging from the application of CREWS both to railroad and to subway companies. The main goal of the development of CREWS was to increase the efficiency of railroad companies through optimized use of human resources. This goal has largely been achieved, but many other benefits, that were not fully apparent when the project started, have surfaced along the years. This paper also addresses some of these issues.
Freight Truck for Higher Speed Operations
Authors: Vithani Anand R. , Booth Graydon F. , Prabhakaran Anand , Singh Som P. , Brabb David C. , Chitti Srinivas , Stewart Monique F. , Punwani S. K.
Published: November 2010

The current freight railroad operations are restricted to a maximum speed of 80 mph partly due to lateral instability of conventional freight trucks at higher speeds. The three-piece truck, a workhorse of the railroad industry for over 100 years, and its variations are susceptible to hunt at 50–55 mph when empty and 90–100 mph in loaded conditions. Design attempts to increase high-speed stability generally lead to diminished curving performance and increased risk of derailment. In this paper we describe a true pendulum suspension based freight truck that is designed to achieve stable operations up to 150 mph without compromising curving performance. The truck’s performance has been analyzed using an industry standard vehicle dynamics simulation tool. The AAR MSRP M-1001 Chapter 11 ‘Service-Worthiness Tests and Analyses For New Freight Cars’ were used to qualify the design where applicable. Traditional tread brakes are supplemented with axle-mounted disc brakes to provide safe braking capabilities beyond 110 mph. Two full-size 70-ton prototypes have been assembled using off-the-shelf and fabricated components. Yard tests have shown that the truck curves properly even under very tight curving conditions.
Applying the European High-Speed Rail Experience to North America
Authors: Lehlbach David S. , Hunt David T. , Foy Kevin M. , Case Rodney E.
Published: November 2010

Driven by a range of factors, there is growing interest in highspeed passenger rail (HSR) and intercity passenger rail (IPR) in North America. A valuable source of information on the cooperation needed to make these services viable in North America is European experience with HSR/IPR, which extends over many decades. North American owners and operators can learn much from Europe with regard to operating dense, mixed-use corridors: Using a “partnership” model, European rail operators have found that when incremental demand for freight and passenger markets are considered together, networks can be expanded faster and further. In North America, a similar partnership approach to capital and strategic planning has already shown huge benefits, for example, in the development of the highly regarded Capital Corridor passenger service in California and in infrastructure improvements on Canadian National’s Kingston subdivision that allow VIA Rail to provide 100–125 mph train service. Through an analysis of current passenger/freight cooperation in Europe, and the examination of HSR/IPR developments and trends in North America, we aim in this paper to illustrate how benefits can be achieved for all stakeholders in the North American rail system as passenger services expand.
Anomalous Heat Conduction, Diffusion and Heat Rectification in Nanoscale Structures
Authors: Zhang Gang , Yang Nuo , Wu Gang , Li Baowen
Published: November 2010

In this paper, we report the recent developments in the study of heat transport in nano materials. First of all, we show that phonon transports in nanotube super-diffusively which leads to a length dependence thermal conductivity, thus breaks down the Fourier law. Then we discuss how the introduction of isotope doping can reduce the thermal conductivity efficiently. The theoretical results are in good agreement with experimental ones. Finally, we will demonstrate that nanoscale structures are promising candidates for heat rectification.
Nanofluid Heat Transfer Enhancement for Nuclear Reactor Applications
Authors: Buongiorno Jacopo , Hu Lin-wen
Published: November 2010

Colloidal dispersions of nanoparticles are known as ‘nanofluids’. Such engineered fluids offer the potential for enhancing heat transfer, particularly boiling heat transfer, while avoiding the drawbacks (i.e., erosion, settling, clogging) that hindered the use of particle-laden fluids in the past. At MIT we have been studying the heat transfer characteristics of nanofluids for the past five years, with the goal of evaluating their benefits for and applicability to nuclear power systems (i.e., primary coolant, safety systems, severe accident mitigation strategies). This paper will summarize the MIT research in this area with particular emphasis to boiling behavior, including, prominently, the Critical Heat Flux limit and quenching phenomena.
CHF of Pool Boiling on Microwires
Authors: Zhao Jian-Fu , Lu Yang-Hui , Li Jing
Published: November 2010

The present paper reports a new series of experimental data of CHF (critical heat flux) of pool boiling on cylinders. Platinum wires of 30 mm in length are simultaneously used as heaters and thermometers. Their diameters are 0.1, 0.06, and 0.025 mm, respectively. FC-72 and acetone are used as working fluids. The range of the subcooling is from 0 K to about 50 K. The gaps between CHF and MHF (minimum heat flux) become narrower and narrower with the decrease of the heater diameter. But it exists even in the saturated pool boiling on the smallest wire in the present study. The dependence of CHF on the subcooling in acetone differs from that in FC-72 though the data locate in the similar range of Bond number in the two different kinds of working fluids. It indicates that interactions between the influences of the subcooling and size on CHF will be important for the small Bond number, and that there may exist some other parameters, which may be material-dependant, in addition to the Bond number that play important roles in the CHF phenomenon with small Bond number.
The Size Effect on Critical Back Pressure Ratio for Sonic Nozzles
Authors: Li Chunhui , Wang Chi
Published: November 2010

As an important parameter, the critical back pressure ratio is directly related with the application of sonic nozzle. When the stagnation condition was fixed, the size effect on critical back pressure ratio was investigated. Some numerical simulations were conducted for sonic nozzles with throat diameter within (0.15–5) mm under laminar flow. From the simulation results, it was clear that the critical back pressure ratio decreased with throat diameter decreasing. From the analyses of flow filed for sonic nozzles with different throat diameters, the most possible reason was the strong interaction between core flow and boundary layer near to the wall, which intensified with throat diameter increasing. As a result, the boundary layer effect decreased with the throat diameter increased, which resulted in the increase of critical pressure ratio with the throat diameter increasing.
Removal of Suspended Particulate Matters by Humidity Swing Operation for Air-Cleaning Method
Authors: Onoda Nagisa , Nakabeppu Osamu
Published: November 2010

The removal effect of a humidity swing operation on suspended particulate matters (SPM) of room air was experimentally studied. The variation of the SPM number between inlet and outlet of an apparatus with a continuous humidification and dehumidification was measured with an optical particle counter. Generally, the filtering method and the electrical-dust-collection method are widely used for the removal of the SPM of sub- to micron-size. At the beginning of this study, the aim was set to investigation of a new SPM removal method using suction flow with condensation of water vapor in moist air. Removal of airborne molecular contaminant and VOC were also expected as well as a humidity control function in the air conditioning system. The experimental results showed that the humidity swing operation increases observable particles and reduces large particles over 5 μm. A large number of liquid droplets were found in observation of collected particles after the humidity swing operation. It was concluded that the nuclear condensation takes place on the SPM in the supersaturation moist air. New whole SPM removal method can be proposed, where the SPM grow to several micrometer sizes by the nuclear condensation by the humidity swing operation, and then the grown particles are easily removed by gravitational sedimentation or an inertial collision method.
Plasmon-Enhanced Quantum Dot Fluorescence Induced by Brownian Motion
Authors: Lee Bong Jae , Hanson Willard , Han Bumsoo
Published: November 2010

Metal-enhanced fluorescence has been extensively studied over the past three decades due to numerous opportunities for enhanced fluorescence sensing and imaging in microfluidics and medical diagnostics. Since the interaction between plasmonic nanoparticles and quantum dots (QDs) is the near-field phenomenon, most of past studies employed dielectric spacers to maintain the nanoscale interparticle distance. In the present study, however, we investigate the enhanced fluorescence from QDs that are mixed with plasmonic nanostructures, such as gold nanoshell (GNS), in the aquatic medium without confining inter-particle distances. Although the near-field interaction could not occur according to the distance estimation based on the particle concentrations, the experimental results indicate that the QD fluorescence can be greatly enhanced. A simple two-dimensional model based on Monte Carlo simulation reveals that there exist considerable probability that QDs reach the near-field region of GNSs due to the thermally induced Brownian motion. The results obtained from this study will facilitate the development of QD-mediated thermometry and ultimately enable image-guided deep-tissue thermal therapy.
Effect of Self-Rewetting Fluids on Pulsating Heat Pipe Thermal Performance
Authors: Fumoto Koji , Kawaji Masahiro , Kawanami Tsuyoshi
Published: November 2010

Pulsating heat pipes (PHPs) have recently emerged as a possible cooling device for high heat flux electronics to replace conventional cooling devices. In this study, new experimental results were obtained for using self-rewetting fluids to enhance the heat transport of PHPs. Unlike other common liquids, the surface tension of self-rewetting fluids increases with temperature. The increase in surface tension at high temperatures causes the liquid to be drawn towards a heated surface if a dry spot appears, which improves boiling heat transfer. PHPs were constructed out of multiport extruded aluminum tubing with a square channel cross section. In experiments, heptanol was added to water at a concentration of less than 1 wt% to form the self-rewetting fluid. Several other parameters were adjusted for optimization, such as the aqueous alcohol solution concentration of the working fluid, the fluid fill ratio, and the heat pipe orientation. Using a self-rewetting fluid in PHPs was found to be highly effective in improving their heat transport capability. The PHPs delivered a better performance when oriented vertically rather than horizontally. As a working fluid, the heptanol water mixture outperformed both the butanol water mixture and pure water within the parameters of this experiment.
Numerical Investigation of Heat Transfer Enhancement on a Small Scale Vortex Generator
Authors: Wang Jiansheng , Yang Zhiqin
Published: November 2010

The heat transfer characteristic and flow structure of fluid in the rectangular channel with different height vortex generators in small scale are investigated with numerical simulation. Meantime, the properties of heat transfer and flow of fluid in the rectangular channel are compared with the channel which located small scale vortex generator. The variation law of local heat transfer and flow structure in channel is obtained. The mechanism of heat transfer enhancement of small scale vortex generators is discussed in detail. It is found that the influence of vortex generator on heat transfer is not in proportion to the size of vortex generator. What is more, turbulent flow structure near the wall, which influences the temperature distribution near the wall, induces the variety of local heat transfer. The fluid movement towards to the wall causes the heat transfer enhanced. On the contrary, the fluid movement away from the wall decreases the local heat transfer.
The Experimental Study on Magnetic Fluid Flat Plate Heat Pipe as Thermal Spreaders
Authors: Zhang Ming , Liu Zhongliang , Wang Chen
Published: November 2010

An effective thermal spreader can achieve uniform heat flux distribution and thus enhance heat dissipation of heat sinks. Flat plate heat pipe is one of the highly effective thermal spreaders. Magnetic fluid is a special fluid that can be made flow by traveling force of magnetic field. Therefore, the magnetic fluid is suitable for using as the working fluid of flat plate heat pipes that have a very small gap between evaporation and condensation surfaces. In this paper, we prepared a disk-shaped wickless flat plate heat pipe, and the distance between evaporation and condensation surfaces is 1 mm. From experimental study, the effects of heat flux and working fluid ratio on the performance of the flat plate heat pipe are obtained and the working performance of the magnetic fluid is compared with that of the water flat pate heat pipe of the same geometry structure.
Second Order Slip Flow Effects on Heat Transfer Performance of Microchannels
Authors: Dolu Cem , Kuddusi Lu¨tfullah
Published: November 2010

First and second order slip flow models in rectangular microchannels heated at constant and uniform wall temperature are studied. The velocity and temperature profiles for hydrodynamically and thermally developed incompressible slip flow regime available in literature are used. The average nondimensional slip velocity and temperature jump are found by using first and second order slip flow models. The average Nusselt number is also derived by using both first and second order slip flow models. The effects of Knudsen number, aspect ratio and second order slip flow model on the heat transfer characteristics of microchannel are explored.
Revisiting the Thermal Conductivity of Nanoporous Materials
Authors: Bera Chandan , Mingo Natalio , Volz S.
Published: November 2010

Although the thermal conductivity of nanoporous materials has been investigated in the past, previous models have overestimated the small pore limit. Various authors had proposed a cylindrical boundary geometry to mimic the pore’s environment. This permits to solve the phonon Boltzmann equation analytically [1] or numerically [2], but for fixed porosity it leads to a saturation of the thermal conductivity at small pore diameters. We show that such saturation is a spurious effect of the cylindrical boundary approximation. By implementing a Monte Carlo calculation with correct boundary conditions, we obtain considerably different thermal conductivities than predicted by the cylindrical boundary geometry. The approach is illustrated in the case of Si and SiGe nanoporous materials.
Development of an Adaptive Vapor Chamber With Thermoresponsive Polymer Coating
Authors: Zhao Yuejun , Chen Tao , Zhang Xiaodong , Zauscher Stefan , Chen Chuan-Hua
Published: November 2010

We propose a novel concept for an adaptive vapor chamber using a thermoresponsive polymer coating to enhance heat transfer and reduce local thermal gradients. By coating the wick structures with stimulus-responsive polymer brushes with an upper critical solution temperature (UCST), the hotter surface becomes more wettable than the colder surface. The smaller contact angle at higher temperature generates larger capillary forces and promotes stronger return flow toward the hotspots. In this paper, we present our progress toward developing the adaptive vapor chamber. We have grafted poly(2-(meth-acryloyloxy)ethyl(dimethyl(3-sulfopropyl) ammonium hydroxide) (PMEDSAH) brushes on silica wafers, and the PMEDSAH polymer coating exhibits UCST properties with stable and tunable wettability. We have captured infrared images of the evaporator with steady and transient heating, and developed a thermographic technique that can be used to test the adaptive wick functionality in a vapor chamber.
The Experimental Study on Cryofreeze-Drying of Porcine Aortic
Authors: Wang Jinfeng , Tao Leren , Wang Yonghong , Huang Lihao , Zhang Shuhong , Liu Mengfang , Wu Jianqing , Li Yongfu , Xi Decheng , Zheng Zhigao
Published: November 2010

At present, the vascular tissue disease has become the major cause to against people’s health, vascular graft is an effective means for the treatment of vascular tissue disease, but the preservation of blood vessels has always been a big challenge. This paper based on the conduct of porcining aortic cryofreeze-drying, with using micro-CT to track the whole drying process, expect to reveal what vascular morphology changes have taken place during the process of cryofreeze-drying, and take a comparative analysis of porcine aortic mechanical properties between freeze-dried after the restoration of water and fresh porcine aortic by the Texture analyzer, so that uncover the effect the process of freeze-dried making on pig arteries mechanical properties. Test results showed that the pig aorta vascular occur stratification in the process of cryofreeze-drying, blood vessels freeze-dried following the resumption of water comparing the mechanical properties with the fresh blood vessels, its maximum axial tensile stress reduced by about 40%, and the largest peripheral tensile stress increase by about 45%, and the biggest puncture stress is about 75 percent of fresh blood vessels.
Improved Thermoelectric Properties of SixGe1−x by the “Nanoparticle-in-Alloy” Approach
Authors: Wang Shidong , Mingo Natalio
Published: November 2010

We theoretically find that embedding silicide nanoparticles in SixGe1-x alloys is able to considerably improve the figure of merit (ZT). We have computed the thermal conductivity as a function of the sizes of NiSi2 and CoSi2 nanoparticles. We find that the optimal nanoparticle diameters minimizing the composite’s thermal conductivity are 6.9 nm for NiSi2 and 12.6 nm for CoSi2 at room temperature. We provide validity ranges of nanoparticle volume fractions that will not reduce the thermoelectric power factor, but will considerably decrease the thermal conductivity. Embedding NiSi2 or CoSi2 nanoparticles in SixGe1-x may lead to a 5-fold increase of figure of merit (ZT ∼ 0.5) at room temperature and 2.8 times increase (ZT ∼ 2.0) at 900 K. The proposed materials with high figures of merit are promising candidates to be used in integrated micro refrigerators in chips and thermoelectric power generation and waste heat recovery.
Biomimetic Passive Skin Cooling for High-End Handheld Devices
Authors: Zhang Xinsheng , Zhou Ming , Huang Zhi , Xu Xiaoding , Zhang Xianzheng , Hu Xuejiao
Published: November 2010

Increasing functionality demands more heat dissipation from the skin of handheld microelectronics devices. The maximum amount of heat that can be dissipated passively, prescribed by the natural convection and blackbody radiation theories, is becoming the bottleneck. In this paper, we propose a novel technique that may overcome this passive cooling limit. It is made possible by using a biomimetic skin capable of perspiration on demand. The key component of the biomimetic skin is a thin layer of temperature sensitive hydro gel (TSHG). The TSHG layer can sweat the skin with moisture when the skin temperature is higher than the TSHG’s lower critical solution temperature (LCST), and thus boost the heat dissipation rate through evaporation. The TSHG layer can be refilled by absorbing the moisture in air when the device batteries are being recharged. A generic practice of this novel cooling technique with preliminary analysis and experimental results is presented. With this novel passive cooling technology, a handheld device can be powered 2–4.8 times higher, and may be powerful enough to run a desktop operation system like a personal computer.
Microscopic Wetting at Nanostructured Surface: A Molecular Dynamics Study
Authors: Nagayama Gyoko , Yanai Kosuke , Kurokawa Kei , Tsuruta Takaharu
Published: November 2010

Wettability of the solid surface is a very important property in the micro/nanoscale thermal fluidic systems. In this study, molecular dynamics simulations were carried out to study the microscopic wetting characteristics at the nanostructured surface and the contacting mode in the vicinity of the solid-liquid-vapor interface. A pure liquid nanodroplet was placed on a solid surface in a shape of molecular-scale unevenness with different height and spacing. The wettability of the solid-liquid interface was examined with evaluating the contact angles at the three-phase interface and the liquid-solid contacting area ratio. The results of the measured contact angles demonstrated that the nanostructures could strengthen the hydrophobic properties for a partial wetting condition, while it was insignificant in a completely wetting case. Furthermore, we compared the results of molecular dynamics (MD) simulations to the classical descriptions of Wenzel’s model and Cassie-Baxter’s model. Significant discrepancy among the results was found and a new model of contact angle in consideration of liquid filling ratio among nanostructures was proposed.
Heat Transfer Characteristic of Meshed Vapor Chamber
Authors: Mo Dong-chuan , Lu Shu-shen
Published: November 2010

Focus on solving the increasing heat fluxes in the electronic industry, vapor chamber shows its excellent characteristic as an effective heat spreading device. A serial of vapor chambers made of copper-water and using mesh as the wick material had been manufactured in this paper. The dimension of the vapor chambers are all 95mm*70mm*3.2mm. A remote method was used to test the performance of the vapor chambers, where the property of evaporation and vapor transportation will be mainly studied. Results show that the adiabatic resistance (vapor transportation) can be less than 0.05°C/W at high heat flux, which means the temperature is almost uniform on the top wall of the vapor chamber. The evaporation heat transfer coefficient could be higher than 20000W/m2K. But compared with the small size of heated zone, the evaporation thermal resistant might be still the largest one in the vapor chambers. The orientations have no obviously effect on the performance of the vapor chamber. As the vapor chamber is small, the gravity effect is not obvious here. The flatness of the mesh may become worse during the operation. To solve this problem, at least two ways can be performed. One is to use some support to keep the mesh attached closed to the wall, and the other is to use the diffusion banding. Finally, we use the experiment data to estimate the thermal resistance of vapor chamber as a heat sink base, and compare with the solid copper to see the potential opportunity to use the vapor chamber.
Experimental Study on Thermal Performance of a Silicon-Based Micro Pulsating Heat Pipe
Authors: Qu Jian , Wu Huiying , Cheng Ping
Published: November 2010

In this paper, an experimental investigation was conducted on the thermal performance of a silicon-based micro-pulsating heat pipe (SMPHP) using FC-72 and R113 as working fluids. The SMPHP, covering an area of 46 × 19mm2, consisted of fourteen meandering trapezoidal channels with a hydraulic diameter of 352μm. The effects of gravity, filling ratio, and working fluids on the overall thermal resistance of the SMPHP were discussed. Experimental results show that gravity had an impact on the thermal performance of the SMPHP, and self-sustained oscillation could not be achieved at the horizontal orientation. The SMPHP worked as a true pulsating device when the filling ratio varied from 30% to 65%. For FC-72 and R113, there was an optimal filling ratio of 55% and 41%, respectively, for the best thermal performance of the SMPHP. As compared to the SMPHP with 0% filling ratio (or charged with the air), the thermal resistances of the SMPHP charged with FC-72 (at 55% filling ratio) and R113 (at 41% filling ratio) were decreased maximally by 7.24°C/W (or 56.5%) and 7.51 °C/W (or 59.7%), respectively. It is also found that the R113 was favorable for the operation of the SMPHP at lower power inputs, while FC-72 was favorable at relatively higher power inputs.
Experimental Research on Microchannel Heat Exchanger Performance for Residential Air Conditioner Applications
Authors: Wu Jianghong , Wang Shuangfeng , Ge Yunting
Published: November 2010

Two type condensers of R22 residential air conditioning systems were investigated in this study. Two R22 residential air-conditioning systems, one with a microchannel condenser and the other with a round-tube condenser, were examined experimentally, while the other components of the two systems were identical except the condensers. Based on the principle of the microchannel condensation, the analysis of heat transfer along parallel heat exchanger was conducted. The non-uniform air velocity distribution at the face of the microchannel condenser and refrigerant distribution in headers were taken into account in this research. The mechanism and possibility of the superior thermal performance as compared with conventional fin-tube heat exchangers were discussed. In addition, the maximum of thermal performance influenced by the running parameter was experimentally measured. The experimental results show that with one third face area of round tube heat exchanger, microchannel condenser’s pressure drop increase around 12–23% and refrigeration output increase 2–5%, refrigerant charge decreases around 50%, it is found to be a promising candidate for residential air conditioning condenser.
Computational Studies of Interfacial Dynamics in Microfluidics via a 3D Spectral Boundary Integral Algorithm
Authors: Wang Yechun , Dimitrakopoulos Panagiotis
Published: November 2010

Interfacial dynamics in micron-sized geometries is getting more attention as technologies evolve towards small scales. In pharmaceutical and biochemical applications, fluid droplets moving in microfluidic channels are utilized as “micro-reactors” to precisely control the reaction rate and enhance the mixing efficiency of the reagents. In emulsion generations, low polydispersity of droplets is achieved by the “passive” fission, fusion and sorting of droplets in microfluidic channels. In nanolithography, a micron/nano sized fluid bridge forms between the substrate and the depositing tip. The ability to numerically simulate in a fast and accurate manner the behavior of a small volume of fluid in microfluidic systems is thus demanded. We utilize a 3D Spectral Boundary Element algorithm for interfacial dynamics in microfluidics that exploits all the benefits of the spectral methods (i.e. exponential convergence and numerical stability) but it is not affected by the disadvantage of the spectral methods used in volume discretization to create denser systems. We consider the deformation and migration of droplets in a square microfluidic channel. We investigate the behavior for a single droplet. The effects of droplet size, flow rate and viscosity ratio will be presented.
Comparison of Acid Gas Control Technologies in EFW Facilities
Authors: Kedrowski Craig , Hug Donald , Frey Reudi , Kaspar Adrian
Published: November 2010

As Energy-from-Waste (EfW) facilities make the leap into the twenty-first (21st) century, so does the demand for cost efficient air pollution control technology. In an effort to meet this rising demand, companies have to develop concepts that remove acid gases in an efficient, sustainable, and reliable way. The current market trend to provide the best available control technology (BACT) leads people searching for technologies that are: • Proven and have extensive records of success. • Highly efficient, resulting in low emission to the atmosphere, but requiring minimal investment. • Compact in design, simple, and low maintenance. • Offering high availability, low reagent consumption, and low residue levels. • Resulting in either clean or suppressed liquid effluents. This paper will specifically discuss the three main types of acid gas control technologies available in today’s marketplace, which include dry, semi-dry, and wet scrubbers. It will first focus on the acid gas control technology most commonly used in the US, the spray dryer absorber, followed by a typical Ring Jet® wet scrubber with packed bed, and finally, the Turbosorp® system. For each of the above technologies, this paper will present the concepts, advantages and disadvantages, achievable emissions, and capital and operating costs. It will then look at how each of these technologies is utilized at existing EfW facilities operating throughout the world and provide information on how each facility has been operating. Lastly, it will look towards the future of acid gas control technologies and provide insight into what advances are being made to meet the most stringent air emission regulation all over the world.
Renewable Energy at Sustainable Cost Using a Combined Heat and Power WTE-Facility in the Paper Industry
Authors: De Greef Johan , De Proft Renaat , Villani Kenneth , Lopez Miguel Angel
Published: November 2010

In March 2008, Keppel Seghers started the engineering, supply, construction and commissioning of a Combined Heat and Power (CHP) Waste-to-Energy (WtE) plant in A˚motfors (Sweden). When completed in 2010 the plant will process close to 74,000 tons per year of household waste (average LHV = 10.5 MJ/kg) and limited quantities of (demolition) wood resulting in a yearly production of about 108,700 MWh of steam, 12,100 MWh of heat and 13,400 MWh of electricity. Herewith, the A˚motfors WtE-CHP is sized to meet the joined energy needs of the local paper production, neighboring industries and buildings at an overall net plant efficiency of almost 65%. The WtE-CHP will offer state-of-the-art combustion and energy recovering technology, featuring Keppel Seghers’ proprietary Air-Cooled Grate, SIGMA combustion control and integrated boiler. Waste is fed into the combustion line with an automatic crane system. To surpass the stringent EU emission requirements, a semi-dry flue gas cleaning system equipped with Keppel Seghers’ Rotary Atomizer was selected as economic type of process for purifying the combustion gas from the given waste mixture. Furthermore a low NOx-emission of 135 mg/Nm3 (11%O2, dry) as imposed by Swedish law is achieved by SNCR. The plant engineering is described with a focus on the overall energy recovery. As stable steam supply to the paper mill and the district heating system needs to be assured under all conditions the design includes for supporting process measures such as combustion air preheating, steam accumulation, turbine bypassing, buffering of the main condenser and back-up energy supply from an auxiliary fuel boiler. Additionally, external conditions can trigger distinct plant operation modes. A selected number of them are elaborated featuring the WtE-plant’s capability to conciliate a strong fluctuating steam demand with the typical intrinsic inertia of a waste-fired boiler. With prices for fossil fuels increasing over the years, the cost for generating process steam and heat has become dominant and for paper mills even makes the overall difference in viability. As will be documented in this paper, the decision to build the A˚motfors WtE-CHP was taken by Nordic Paper after a quest for significant cost-cutting in the production of process energy. Moreover, the use of industrial and household waste as fuel brings along the advantage of becoming largely independent from evolutions on the international oil and gas markets. By opening up the possibility for a long-term secured local (waste) fuel supply at fixed rates, WtE-technology offers a reliable alternative to maintain locally based industrial production sites. The Nordic Paper mills in A˚motfors are therefore now the first in Sweden to include a waste-fired CHP on a paper production site.
A Risk Assessment Framework for Evaluating Health Risks From New and Emerging Waste Management Technologies
Authors: Zemba Stephen G. , Binder James J. , Ames Michael R. , Lester Richard R.
Published: November 2010

Until recently, landfills and waste-to-energy (WTE) facilities were the two basic technologies available to process residual (post-recycled) municipal solid waste. These technologies have both advantages and drawbacks, and their relative merits have been debated many different ways. Risk assessments of both technologies have been used to examine their potential threats to human health and the environment, and have found both landfills and WTE facilities can be operated in an environmentally acceptable manner. Neither alternative, however, has gained general public acceptance, and planned projects are often controversial. There remains considerable skepticism, for example, that landfill liners will be effective over long periods of time, and a general uneasiness over the safety of waste combustion. The interest in emerging conversion technologies, such as gasification and anaerobic digestion, as an alternative to conventional landfills and WTE facilities is thus understandable. However, there is some concern that the environmental impacts of conversion technologies are not well understood, as no commercial facilities exist in the United States. Development of a risk assessment framework for evaluating conversion technologies will serve two purposes. First, it will ultimately facilitate objective evaluation of potential risks to health and the environment as well as comparative evaluation with respect to traditional landfill and WTE technologies. Second, it will initiate a conceptual model of environmental impacts that will be useful in identifying key emissions and data gaps. Our presentation will set forth an initial risk assessment framework, focusing on the emissions and residuals of conversion technologies, and using available data to characterize and project health risk impacts.
Waste Composition in the Northeast U.S.: Implications for Resource Recovery
Authors: Bobman Mark , Culbertson John
Published: November 2010

Waste composition studies can provide meaningful data for design and operation of resource recovery processes. However, relatively limited attention has been devoted to energy recovery predicted by waste composition analysis, despite increasingly detailed analysis of various subsets of the municipal solid waste stream. Further, global economic conditions and markets have dramatically altered since 2008, resulting in significant changes in corporate, institutional and consumer spending patterns. Associated with these shifts in spending, as well as with longer-term trends in packaging and advances in residential and commercial recycling, the quantity and makeup of discarded materials has changed. The authors present data resulting from recent waste composition studies, and discuss potential impacts on the design and operation of material recovery systems.
Measuring the Sustainable Return on Investment (SROI) of Waste-to-Energy
Authors: Williams John F. , Parker John C.
Published: November 2010

Waste to Energy facilities serve their communities in a number of important ways. Our industry does a terrific job reducing volumes that would have otherwise been destined for landfills. Energy recovery is an important and positive byproduct of that process but not the only one. Beyond these two obvious attributes you seldom hear of anything else. This is unfortunate because there are significant social, environmental, and economic benefits associated with the technology. Industry “silence” can be attributed to an inability to describe those benefits in ways people understand or see a dollar value in. In other words, we have a tough time measuring the value of “Green.” This paper describes a framework through which we can make the case for sustainable benefits associated with Waste to Energy. It begins with discussion of why it is important to seek a connection with the “triple bottom line” including the social, environmental, and economic attributes of a given program/project/facility. It sheds light on the need to think beyond traditional life cycle cost analysis techniques that focus on direct cash benefits. It describes a process through which noncash and external costs and benefits can be calculated and presented in monetary terms, referred to as the Sustainable Return on Investment or SROI (direct cash + noncash + external costs and benefits = SROI). This paper should help readers make an aggressive case to reveal the FULL VALUE of Waste to Energy across the sustainability triple bottom line.
Integrated Recycling Strategy at Waste-to-Energy Facilities
Authors: Sfeir Hala , Gutner Sandy
Published: November 2010

In this paper, we summarize Massachusetts’ new Class II Recycling Program regulations and present the preliminary results of Waste Characterization Studies being performed at three waste-to-energy (WTE) plants. We discuss how a Waste Characterization Study can help both the facility and the state to assess the success of existing recycling programs and develop strategies for future programs.
Sustainability in Energy From Broward County’s Waste-to-Energy Plants
Authors: Tewari Ram , Gosine Jairaj , McIlvaine Scott
Published: November 2010

Sustainability and Going Green have been the recent buzz words in the solid waste management field. These two words have an ongoing impact on planning (for either a new project or for refurbishment), performance, people, planet Earth and our quality of life. So the challenge for solid waste professionals is to optimize a balance among environment, natural resources and solid waste management technologies. This paper describes such a sustainability and greening effort through a public–private partnership initiative for an integrated solid waste management for our two Broward County, Florida facilities. Water conservation and use of wastewater, experimental use of waste (sludge) from water treatment plants, continuous quality improvement by monitoring, process optimization and design approaches are some of the on-going areas where efficiencies are being realized.
A Study on Performance and Emissions of a 4-Stroke IC Engine Operated on Landfill Gas With Syngas Addition
Authors: Lee Jechan , Castaldi Marco J.
Published: November 2010

The aim of this study is to investigate the suitability of landfill gas (LFG) as an alternative fuel for an internal combustion (IC) engine and how to reduce pollutants emissions from LFG operations by adding syngas to LFG. The effect of CO2 fractions in LFG on the engine performance and exhaust emissions such as CO, UHC and NOx are experimentally determined, and a simulated LFG (50% CH4 and 50% CO2) mixed with a simulated syngas consisting of H2 and CO (H2/CO = 2) is also studied. The Honda GC160E engine connected with a small generator which functions as different electrical loads is used for this study. When CO2 fraction in LFG changes from 0% to 50% at 0.8 kW load condition, CO and UHC emissions increase from 241.8ppm to 802.1ppm and from 35.6ppm to 113.4ppm respectively, while NOx emission decreases from 126.7ppm to 99.8ppm. In case of LFG (50% CH4 and 50% CO2)-syngas (H2/CO = 2) mixtures, 5% addition of syngas to LFG at 0.8 kW load condition reduces CO, UHC and NOx emissions from 802.1ppm to 203.1ppm, from 113.4ppm to 11.1ppm and from 99.8ppm to 64.5ppm, respectively. However, when more syngas is added to LFG (10% and 15% syngas in fuel mixture) it does not measurably reduce these emissions any further.
Energy Recovery From Municipal Solid Waste in California: Needs and Challenges
Authors: Helou Alexander E. , Tran Kim , Buncio Cecile
Published: November 2010

Thermal technologies, such as gasification, pyrolysis, waste-to-energy (WTE), and advanced thermal recycling (second generation WTE with the most advanced air emission control system), can be employed to recover energy from municipal solid waste (MSW), reduce the volume of material to be landfilled, and lessen the potential emission of methane. Methane is a potent greenhouse gas and a major component of landfill gas. All operating WTE facilities in the United States have been subjected to strict environmental regulations since the passage of the Clean Air Act Amendments in 1990. As a result, U.S. WTE facilities now meet or exceed stringent local air quality standards, including those imposed by the South Coast Air Quality Management District (SCAQMD) in Southern California. The United States Environmental Protection Agency (EPA) recognizes the important role of WTE in the integrated solid waste management and ranks combustion higher than landfilling in its solid waste management hierarchy. In addition to upstream source reduction and recycling, downstream thermal treatment of the residual MSW (conducted in controlled environment) can effectively recover energy and further reduce waste volume. Despite all the advantages and environmental benefits of thermal technologies, its utilization for treating MSW in California still faces many challenges. These include negative public perceptions, economical disadvantages, local marketability of by-products, and disposal options for residuals. This paper discusses the need to include energy recovery in the integrated MSW management in California and the challenges encountered by many local jurisdictions.
Advancements in Grate Cooling Technology
Authors: Owens Emily M. , Szczepkowski Joe
Published: November 2010

Over the last few years an increase in the calorific value of the waste has been observed at our waste-to-energy facilities. Wheelabrator Technologies, Inc. in conjunction with Von Roll/Inova decided to install a zone of water-cooled grate blocks at the Millbury Massachusetts waste-to-energy facility as a pilot program. Common in Europe these water-cooled grate blocks address the issue of higher BTU waste and increase the overall life expectancy of the blocks compared to regular air-cooled grate blocks. This technical paper provides an overview on the installation, operation, and maintenance of a zone of water-cooled grate blocks. Discussed are the procedures for evaluating the overall project and some of the challenges we resolved.
Haptic Assembly of CAD Models Using Virtual Constraint Guidance
Authors: Tching Loi¨c , Dumont Georges , Perret Je´roˆme
Published: November 2010

In the context of virtual reality (VR) and of computed aided design (CAD), haptic simulations are used to perform assembly tasks between 3D objects. To help the user to perform the assembly of CAD objects, we propose a new method of interactive assembly that uses both kinematic constraints and virtual guiding fixtures. Modelling a haptic assembly task as a combination of mechanical joints, we focus on the guidance of objects and on the activation cues of kinematic constraints within physical simulation. In this article, we first outline the difficulties related to the haptic-assembly of CAD objects in VR simulation. Introducing the virtual constraint guidance (VCG), we present a new method for haptic guidance that decomposes a task in two independent steps: a guiding step which use geometries as virtual fixtures to position objects, and a functional step that use kinematic constraints to perform the assembly task while deactivating locally the collisions between objects. We finally present a complete application of our method on a insertion task and present our experimental results concerning the usability of our method.
Towards Point-Based Haptic Interactions With Deformable Objects
Authors: Shi Wen , Payandeh Shahram
Published: November 2010

In this paper, a novel haptic interaction framework for deformable objects is introduced and discussed. Unlike existing frameworks, the proposed approach is based on point-based mechanics framework. Contrary to the finite-element method, the method of this paper does not rely on any predefined mesh representation, and it also incorporates real material properties in the modeling framework. As a result, the haptic interaction produces realistic model behaviour and force feedback. In addition, the framework can be constructed using the actual 3D volume data obtained from various imaging modalities. In this paper, preliminarily implementation issues of this new frame work are discussed and experimental data are compared to the FEM.
An Integrated Calibration Technique for Multi-Camera Vision Systems
Authors: Vader Anup M. , Chadda Abhinav , Zhu Wenjuan , Leu Ming C. , Liu Xiaoqing F. , Vance Jonathan B.
Published: November 2010

This paper presents the integration and evaluation of two popular camera calibration techniques for multi-camera vision system development for motion capture. An integrated calibration technique for multi-camera vision systems has been developed. To demonstrate and evaluate this calibration technique, multiple Wii Remotes (Wiimotes) from Nintendo were used to form a vision system to perform 3D motion capture in real time. This integrated technique is a two-step process: it first calibrates the intrinsic parameters of each camera using Zhang’s algorithm [5] and then calibrates the extrinsic parameters of the cameras together using Svoboda’s algorithm [9]. Computer software has been developed for implementation of the integrated technique, and experiments carried out using this technique to perform motion capture with Wiimotes show a significant improvement in the measurement accuracy over the existing calibration techniques.