bluuebunny/crossref_metadata_2025_split huggingface dataset:
Repurposing Waste Steam and Hot Water to Accelerate Plant Growth in Heated Green Roofs
Authors: Dell Robert , Unnthorsson Runar , Wei C. S. , Foley William 
Published: April 2014

Municipal steam district heating services such as New York City’s Consolidated Edison’s have no recirculation system. The waste heat, usually in the form of steam condensate and hot water, is mixed with and cooled by municipal potable water. Since 2006, The Center for Innovation and Applied Technology and The Laboratory for Energy Reclamation and Innovation at the Cooper Union have been developing a system to use this thermal pollution to heat the growth medium of green roofs. The authors have also constructed three geothermal heated gardens systems in Iceland. American Society of Heating, Refrigeration and Air Conditioning Engineers (ASHRAE) specifications for heated sidewalks were referenced in all locations.
The heated green roofs have the potential to save more than 2,000,000 cubic meters of potable water if applied to 40% of Consolidated Edison’s steam customers. Plant growth is often accelerated by 20% or more in all locations.
An Experimental Study of Turbulent Non-Newtonian Fluid Flow in Concentric Annuli Using Particle Image Velocimetry Technique
Authors: Bizhani Majid , Rodriguez Corredor Fabio Ernesto , Kuru Ergun 
Published: April 2014

Turbulent flow of a Non-Newtonian polymer fluid through concentric annuli was studied using 9 m long horizontal flow loop (inner to outer pipe radius ratio = 0.4) and Particle Image Velocimetry (PIV) technique.
A high molecular weight, anionic, water soluble, acrylamide-based copolymer was used as a viscosifier. The aqueous polymer solution exhibited power law rheology with strong shear thinning behavior.
Experiments with aqueous polymer solutions have been conducted at the same bulk velocity as water experiments. Mean bulk velocity values changed from 0.827 to 1.164 m/s, corresponding to solvent (water) Reynolds number from 46000 to 68000.
Mean axial velocity and Reynolds stress distribution in the near wall region (considering both inner and outer walls) and in the whole annular gap were determined. Axial mean velocity profile was found to be following the universal wall law close to the wall, but it deviated from logarithmic law with an increased slope in the logarithmic zone.
Radial locations of the maximum velocity values were also determined and compared to that of water flow. For the range of Reynolds numbers studied, location of maximum velocity was found to be dependent on Reynolds number. As Reynolds number increased, location of maximum velocity moved closer to inner wall.
Reynolds and laminar stresses were calculated. Reynolds stresses for polymer fluid flow decreased with increasing polymer concentration and were found to be always smaller than that of water. Laminar stresses, on the other hand, were found to be always higher at higher polymer concentration, reflecting the effect of the fluid viscosity.
Near Wall Turbulence Characteristics of a Drag Reducing Polymer Fluid Flow in Concentric Annulus Using CFD
Authors: Rahman Aziz , Rodriguez Corredor Fabio Ernesto , Bizhani Majid , Kuru Ergun 
Published: April 2014

A CFD simulation was conducted to analyze the near wall turbulence characteristics of a drag reducing (DR) polymer fluid (0.12% V/V) flow through concentric annulus. The continuity and momentum equations were solved by using a commercial CFD package (CFX 14) with the Shear-Stress-Transport (SST) model option. The simulation results were compared to the experimental data obtained by using high resolution Particle Image Velocimetry (PIV) analyses of drag reducing polymer fluid flow in a horizontal concentric annulus. A fully developed turbulent flow of water through a horizontal flow loop (ID = 9.5 cm) with concentric annular geometry (inner to outer pipe radius ratio = 0.4) was used for comparison purpose. The flow rates ranged from 3.92 to 5.95 kg/s. Drag reducing PHPA solutions behaved as a power law fluid with the rheological model (μ = Kγn−1) for the shear rate of 1/s to 600/s.
Bulk and near wall velocity profile obtained from simulation showed good agreements with the experimental data. Drag reducing polymer reduce the Reynolds stresses level due to weaker and fewer turbulent eddies formation near the wall. Results of the simulation study also showed that if the flow rates of power law fluid increased from 3.92 to 5.95 kg/s, the drag reduction in the annuli is increased from 10% to 20% compared to water case indicating the strong damping to turbulent kinetic energy in the flow. The CFD analyses using SST model is computationally inexpensive and, therefore, can be conveniently used for investigating the flow characteristics of drag reducing polymer fluids in concentric annulus.
Design Principles for the Conceptual Design of Low-Cost Prosthetic Knee
Authors: Duenas Victor H. , Vargas-Hernandez Noe 
Published: April 2014

The objective of this paper is to document design lessons learned in the development of low-cost lower-limb prosthetic devices. Four design principles are introduced based on the authors′ experience redesigning a low-cost prosthetic knee mechanism. These design principles are valuable sources to complete the conceptual design of the knee mechanism in the absence of a unique or exact methodology that comprises all the aspects concerning engineering design.
The paper defines the motivation to improve life quality by restoring knee functionality in terms of mobility and stability. Subsequent sections explore the state of the art, design constraints, gait analysis, and 3-D modeling using CAD. The model is validated using kinematic and structural simulation in NX 7.5™ covering basic geometric parameters and motion assumptions. The four conceptual design principles are: Hybrid Design Model, Simultaneous Modeling, Multidisciplinary Pulses, and Built-in and Post-design Optimization. Each principle is presented to exemplify its contribution in the knee mechanism redesign. Finally, the design principles are intended to assist the designer with empirical guidelines in the development of prosthetic devices.
Elastoplastic Analysis of a Cantilever Beam Under Combined Compressive and Bending Load
Authors: Boix Salazar Julio A. , de Lange Dirk F. , Cruz Alberto Torres , Medellín Castillo Hugo I. , Rodríguez Gilberto Mejía 
Published: April 2014

In this study the elastoplastic behavior of cantilever beams under a combined compressive axial load and an imposed lateral bending deflection are analyzed. Eventhough the particular condition of elastoplastic buckling has been studied before, the developed theories are limited to the prediction of the initial failure of the beam. In the current study the elastoplastic behavior of cantilever beams under compressive load at levels below the critical buckling load are studied in order to determine the remaining load bearing capacity of the beam under combined bending and axial loads, including the behavior at progressive levels of plastic deformation.
The elastoplastic bending process is analyzed using the finite element method. In particular, the analysis is focused on the evaluation of the limiting bending force necessary to increase or reduce the curvature of the beam in the plastic zone. The bending force depends on the compressive axial load, the geometrical dimensions of the beam, material coefficients, such as Young’s modulus and yield stress, and the hardening model. The large number of variables involved, is reduced by introducing two dimensionless load parameters.
The results of the analysis are presented and discussed for a wide range of dimensionless loads. Also the influence of work hardening on the obtained bending force is analyzed, comparing between an ideal plastic behavior and a bilinear plasticity model with a linear hardening behavior.
Influence of Modeling Assumptions on the Simulated EDM Performance
Authors: Escobar Agustín Márquez , de Lange Dirk F. , Medellín Castillo Hugo I. , Pérez Gutiérrez Francisco G. 
Published: April 2014

Electrical Discharge Machining (EDM) is a non-conventional machining process widely used to manufacture hard material components which are not easily machined by conventional machining processes. Several modeling approaches have since long been proposed to characterize the EDM process, based on the electro-thermal phenomena that occur. Several of these early models are analytical models that have the major advantage of providing predictions of process performance based on analytical solutions. Unfortunately, their derivation often demands a number of assumptions and simplifications, which can limit the scope and precision of the predictions obtained. Two of the most known analytical models are based on different heat sources: a point heat source [1], and a uniform disk heat source [2].
In this paper, these two analytical EDM models are analyzed and compared with more elaborated numerical models in which specific modeling assumptions are lifted; the objective is to quantify the influence of each of these assumptions on the final result. Numerical simulations are based on the finite element method, which enables to study the influence of different temporal pulse shapes, the spatial intensity distribution, the temperature dependency of the thermal coefficients, and in particular the influence of the way latent heat is taken into account. The results are analyzed in terms of the predicted material removal rate (MRR), depth and radius of the crater. A comparison is presented between the two theoretical results [1], [2], and those obtained by the more elaborated numerical models. At the same time, a comparison is also made with some experimental data from literature.
Viscoelastic Strain Response (ViSR) Ultrasound in Pre-Clinical and Clinical Application
Authors: Scola Mallory R. , Kornegay Joe N. , Howard James F. , Nichols Timothy C. , Gallippi Caterina M. 
Published: April 2014

Viscoelastic Strain Response (ViSR) ultrasound is a novel acoustic radiation force (ARF)-based imaging method that noninvasively interrogates the viscoelastic properties of tissue by measuring the relaxation time constant for constant stress in the Voigt biomechanical model. The time constant is defined as the ratio of coefficient of viscosity to elastic modulus, so ViSR differentiates tissue with disparate viscosities and elasticities. ViSR ultrasound is performed by delivering two successive ARF impulses to a single region of exciation (ROE) and tracking the micrometer-scale displacements induced by the propagating longitudinal waves. ViSR does not rely on transverse wave propagation, which can be disrupted and difficult to track in heterogeneous and/or geometrically complex media. Another advantage to ViSR ultrasound is a large axial range relative to conventional ARF Impulse (ARFI) ultrasound.
In this overview, ViSR methods are discussed and demonstrated in calibrated viscoelastic tissue mimicking materials. ViSR ultrasound is then applied to differentiating fatty and fibrous deposition in muscle in a golden retriever muscular dystrophy (GRMD) dog model and in boys with Duchenne muscular dystrophy (DMD) with correlation to standard physical testing. ViSR is also applied to delineating the structure and composition of atherosclerotic plaques in a hypercholesterolemic pig model with histochemical validation. ViSR’s key advantages and disadvantages are discussed in regard to its general clinical utility.
Preliminary Performance Test of Mechanical Pump for a Stella-1
Authors: Han Ji-Woong , Ko Bock Seong , Park Sang-Jun , Lee YoonSang , Jeong Ji-Young , Lee Yong Bum 
Published: April 2014

In the process of sodium-cooled fast reactor (SFR) design, it is very important to verify thermo-hydraulic performance of each component in the sodium environment. In KAERI (Korea Atomic Energy Research Institute) STELLA (Sodium Integral Effect Test Loop for Safety Simulation and Assessment) project is under a Mid- and Long-term Nuclear R&D Program. The STELLA project is composed of two stages. In the 1st stage the performance for heat exchangers such as DHX (Decay heat exchanger) and AHX (Air heat exchanger) and for PHTS (Primary heat transport system) mechanical pump will be evaluated. The detailed design of each component is based on that of a 600MWe demonstration reactor.
Since full-scale components could not be installed in STELLA-1 [1], the model pump is designed to be scaled-down based on the scaling law. Various pump tests have been done in water environment by using model pump.
In this study the design features of model pump were described and the scaling parameters were examined. The results of pump performance tests have been also introduced which is essential to perform safety analysis.
A Review of Nuclear Power in China
Authors: Catlow Fred 
Published: April 2014

Whilst nuclear power does not seem to have the support of public opinion in many parts of the world China is forging ahead with its ambitious nuclear programme. Some might argue that this is to support their weapons programme but that clearly is not the case and is undoubtedly to provide a stable source of energy for the generation of electricity but also for alternative peaceful uses such as desalination.
This paper covers the history of nuclear power in China over more than thirty years and addresses what impact, if any, their policy of continued expansion of nuclear power will have on the rest of the world. The different reactor types installed in China is reviewed, the infrastructure and the overall strategy is surveyed.
Application of Thermal Hydraulic and Severe Accident Code SOCRAT/V3 for Calculation of Air Ingress Experiment QUENCH-16
Authors: Vasiliev Alexander 
Published: April 2014

The thermal hydraulic and SFD (Severe Fuel Damage) best estimate computer modelling code SOCRAT/V3 has been used for the calculation of QUENCH-16 experiment which was performed in the frame of the EC supported LACOMECO programme.
The QUENCH-16 test conditions simulated a representative scenario of LOCA (Loss of Coolant Accident) nuclear power plant accident sequence in which the overheated up to 1800K core would be reflooded from the bottom by ECCS (Emergency Core Cooling System). The QUENCH-16 experiment included the following phases: first heat-up phase, pre-oxidation phase, slow cool-down phase (preparatory to air ingress), air ingress phase and bottom water flooding phase.
The test QUENCH-16 was successfully conducted at the Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany, on July 27, 2011. The primary objective of this test was to investigate the oxidation of Zircaloy in the air following a limited pre-oxidation in the steam and to achieve a long period of oxygen starvation to promote the interaction with the nitrogen. Unexpectedly high cladding oxidation rate was detected during flooding phase which resulted in huge hydrogen production in QUENCH-16. It was due to zirconium nitride (ZrN) formation in a cladding which induced a diffusion transparency of zirconium dioxide layer.
QUENCH facility is designed for studies of the PWR fuel assemblies behaviour under conditions simulating design basis, beyond design basis and severe accidents.
SOCRAT/V3 computer modelling code was used for estimation of basic thermal hydraulic, oxidation and air ingress parameters in QUENCH-16.
The calculated results are in a reasonable agreement with experimental data which justifies the adequacy of modeling capabilities of SOCRAT code for application to such a complicated test as QUENCH-16.
Gravity-Assisted, Passive Cancellation of Disturbances for Inertial Sensors
Authors: Karpachevskyy Taras , Spiewak Swavik 
Published: April 2014

Continuing enhancements in Microsystem Technologies facilitate the development of inertial sensors — accelerometers and gyroscopes — of unprecedented performance to cost ratio and broaden the frontiers of their application. Of particular interest, because of their immunity to ambient disturbances, are sensors equipped with high resolution Electro-Mechanical ΣΔ converters and with a high speed, digital serial signal transmission. The digital circuitry of these sensors reaches the accuracy of 0.02 parts-per-million (ppm). However, the analogue transducers of measured physical quantities into electrical signals inside of the even best inertial sensors are prone to inherent imperfections of analog systems such as nonlinearity, cross-sensitivity, or noise. The best accuracy of these transducers is about two orders of magnitude worse than that of the electrical circuitry. The overall accuracy can be greatly improved by using corrective filters that cancel the effects of imperfections in the analogue transducers. The effectiveness of these filters hinges upon the accuracy of identifying comprehensive models of the analogue transducers.
Ambient disturbances, in particular mechanical vibrations, greatly deteriorate the accuracy of identification. Their impact can be attenuated to some extent by using vibration isolation platforms. The effectiveness of attenuation is usually good at the frequencies above 5–10 Hz, however it is poor at low frequencies. This poor attenuation is a significant disadvantage since the low frequency phenomena in inertial sensors have pronounced impact on their suitability for a broad class of applications (e.g., navigation).
The presented research focuses on the design of a passive vibration isolation device in which horizontal movement is coupled to tilt in a way that a component of the gravity perceived by the tested inertial sensor effectively cancels out the horizontal acceleration coming from the ambient vibrations.
Counter-Rotating Type Tidal-Stream Power Unit Playing Favorable Features in Various Ocean Circumstances
Authors: Usui Yuta , Takaki Kohei , Kanemoto Toshiaki , Hiraki Koju 
Published: April 2014

The authors have invented the unique counter-rotating type tidal-stream power unit, which is composed of the tandem propellers and the double rotational armature type peculiar generator without the traditional stator. In the unit of the downstream type, the front and the rear propellers counter-drive the outer and the inner armatures of the peculiar generator respectively, in keeping the rotational torque counter-balanced between both propellers/armatures.
This paper discusses and verifies experimentally the almighty features of the power unit. The axial force acting on the pillar increases naturally with the increase of not only the stream velocity but also the drag of the tandem propellers. Besides, the tandem propellers bring the symmetrical vertical force from side to side though the single propeller brings the force in one direction. The counter-balanced torque makes it possible to moor the power unit with only one cable/wire/rope, and the behavior of the submerged unit was confirmed experimentally.
Application of Artificial Neural Network for Single Horizontal Bare Tube and Bare Tube Bundles in Gas-Solid (Air-Solid) Fluidized Bed of Small and Large Particles: Heat Transfer Predictions
Authors: Govindaswamy Ravindranath , Srinivasan Savitha 
Published: April 2014

This paper presents heat transfer analysis of single horizontal bare tube and in-line arrangement of bare tube bundles in gas-solid (air-solid) fluidized bed and predictions are done by using Artificial Neural Network (ANN) based on the experimental data. Measurement of average heat transfer coefficient was made by local thermal simulation technique in a cold square bubbling air-fluidized bed of size 0.305m × 0.305m. Studies were conducted for single bare tube and bare tube bundles of in–line arrangement using beds of small (average particle diameter less than 1mm) silica sand particles and of large (average particle diameter greater than 1mm) particle (raagi and mustard). Within the range of experimental conditions influence of bed particle diameter (Dp), fluidizing velocity (U) were studied, which are significant parameters affecting heat transfer.
Artificial neural networks (ANNs) have been receiving an increasing attention for simulating engineering systems due to some interesting characteristics such as learning capability, fault tolerance, and non-linearity.
Here, feed-forward architecture and trained by back-propagation technique is adopted to predict heat transfer analysis found from experimental results. The ANN is designed to suit the present system which has 3 inputs and 2 outputs. The network predictions are found to be in very good agreement with the experimental observed values of bare tube heat transfer coefficient (hb) and Nusselt number of bare tube (Nub).
Thermal Conductivity Measurements of Ultra-Thin Amorphous Poly(Methyl Methacrylate) (PMMA) Films
Authors: Kim Ickchan , Burzo Mihai G. , Komarov Pavel L. , Raad Peter E. 
Published: April 2014

As technology progresses towards smaller and higher density microelectronic devices, we are faced with working with atomic-scale dimensions that present us with challenges but also opportunities. Since mechanical and chemical properties of ultra-thin polymeric films can vary dramatically from their bulk, the thermophysical properties of thin films are also expected to vary. Ultra-thin poly(methyl methacrylate) (PMMA) films have been the focus of numerous investigations in recent years as a data storage medium. Employing Atomic Force Microscopy (AFM) technology, it is possible to store data bits by heating a target zone until it melts, which leaves a nano-dimple indentation in the PMMA polymer film. The AFM technology has great potential because it possesses considerable data density when compared to conventional magnetic data storage. Since the amount of heat that needs to be used to melt the nanoscale region of the polymer needs to be precisely controlled, knowing the thermophysical properties of such films is a critical factor in advancing this technology. It is known that heat carriers such as electrons and phonons in metallic and dielectric materials, respectively, are influenced by the “size effect” in the micro and nano-scale dimensions. Therefore, a goal for this investigation is to determine whether any dependence exists between the PMMA’s film thickness and its thermal conductivity.
In this work we investigated whether a “scale effect” on intrinsic thermal conductivity actually exists for amorphous PMMA films with thicknesses ranging from 40 nm to 2 μm. The approach is based on the transient thermoreflectance (TTR) method, where the change in the surface temperature is measured by detecting the change in the reflectivity of the sample. The sample is heated by laser irradiation and probed using a continuous-wave laser that detects changes in the reflectivity of the heated material surface. The experimentally obtained transient temperature signature is then used to extract unknown values of thermal properties. Based on our previous experience with measuring a wide range of thin-film materials and the data available in the literature, we expected a lower thin-film thermal conductivity as compared to the bulk value. Surprisingly, the results show that the intrinsic thermal conductivity of layers thinner than 40 nm PMMA film deposited on native silicon oxide is about three times higher than the bulk PMMA value. A similar trend was observed for all ultra-thin (sub 100 nm) films.