bluuebunny/crossref_metadata_2025_split huggingface dataset:
Building Energy Scenarios for Large Water Pumping Systems
Authors: Gil Samaniego Ramos Margarita , Campbell Ramírez Héctor Enrique 
Published: October 2013

The life quality of the world’s population and its development activities mainly depend on the availability, quantity and quality of fresh water. Water scarcity at many regions around the globe present challenges towards improving efficiency and rationalizing its use. The state of Baja California, México, is located at the northwestern corner of Mexico at a large semiarid region where rain incidence is very low (169 mm annually); thus, its water provision is also scarce. Federal and state governments have made efforts to guarantee water accessibility to its municipalities. The Río Colorado-Tijuana Aqueduct (ARCT) is a large water supply system that provides 5.33 m3/s of water to these cities. Its 6 pumping stations elevate the water 1,061 m through 147 km of pipes, canals and tunnels, and its total installed motor capacity is of 106,000 HP.
Pumps are high energy consumers and represent a large fraction of operating costs in water supply systems. The volume pumped by the ARCT in 2010 was of 80.7 million of m3, while consuming 322.7 GWh annually at a cost of 23.8 million dollars. Implementing actions for the saving and efficient use of energy in hydraulic facilities is a worldwide priority to achieve rational water management and therefore national and regional sustainable development. Methodologies that improve energy savings while satisfying system performance criteria should be sought for better performance and management of the water supply systems.
For building energy scenarios for such systems, it is necessary to integrate and adapt different methodologies for the simulation and assessment of behavior and performance taking in account hydraulic, electric and economic issues. This paper presents different approaches and results when these methodologies are applied for the case of ARCT.
Study of Flow Field Variables in a Pressure Reducing Valve
Authors: Adhikari Param , Panta Yogendra M. , Reppert Benjamin 
Published: October 2013

Pressurized water valves are required in industrial applications ranging from steel industries to manufacturing plants where cooling is highly required. High water pressures are the most common requirement to descale oxide layers formed during steel production. The water passes through pumps, piping systems and valves before it flows out through nozzles. Such a high pressure requirement is generated from pumps and regulated by means of valves. The directional checking and ON-OFF regulation are the major jobs a valve should perform satisfactorily. The fluid properties are governed by mass, momentum and energy conservation as defined by Continuity, Navier-Stokes and Energy equation. The high pressure drop along the neck of the venturi induces cavitation problems which lead to failure over time.
Variation of several fluid properties like pressure, wall shear stress can be seen as the fluid flows through the valve. The high pressure fluid at the upstream region goes through the downstream region from the nozzle when the given valve allows to exit. The sharp bends and turns inside the valve causes several properties of water to change throughout its flow domain. The failure being observed on a high pressure water flow passage on a specific geometrical cross section from one of the local companies will be evaluated from the computational analysis. Lately, a baffle system was modeled in 2D as one of the capstone design projects for an undergraduate student. The main objective of this system was to attain a pressure drop within the channel to prefill all the pipes and valves connected along the line so that sudden descaling high pressure would not burst the air along the pipe. No pressure based density variation was employed in this study. The wall shear stress computed using ANSYS Fluent code was found to be max where the actual failure had occurred. It has been noted that no pressure based density variation was employed in this study.
Motion Analysis of Weaving “Kana-ami” Technique With Different Years of Experience
Authors: Tsuji Ken-ichi , Narita Chieko , Endo Atsushi , Takai Yuka , Goto Akihiko , Sasaki Gen , Ohta Tomoko , Hamada Hiroyuki 
Published: October 2013

The technique of making “KANA-AMI” is traditional craftsmanship in Kyoto. All wire net fabrications are made by the hand work, so that it is expected that the craft man has the exquisiteness of motion. The purpose of this study is to clarify the characteristics of motion during the weaving the wire nets with different years of experience.
The subjects were three males whose have experienced wire netting craftsman for 44 years, 8 years and 0 years respectively. The working environment was reproduced in the laboratory so that the subjects might work usual like working environment as much as possible and they could concentrate on them work. The infrared reflection markers were affixed at 21 points on the body of the craftsman to analyze motion during the wire netting. And six cameras (hawk-i Motion Analysis Co. Ltd.) captured the position of each marker, and all markers position data which synchronized were taken in by a computer (sampling rate: 100Hz). It was defined that right to left direction was X axis, front to rear direction was Y axis, top to bottom direction was Z axis for subjects. In addition, shape and degradation of wire net were evaluated. The shapes of hexagonal pattern were evaluated. Degradation of wire nets were evaluated by salt spray tests.
Adaptive Electromagnetic Torsional Tuned Vibration Absorber and its Application in Rotating Equipment
Authors: Seer Taher Abu , Vahdati Nader , Karki Hamad , Shiryayev Oleg 
Published: October 2013

Rotating equipment is susceptible to torsional vibrations whenever the RPM of the rotating equipment matches one of the torsional natural frequencies. For rotating equipment running at constant RPM, it is easy to control and mitigate the torsional vibrations, but in applications where the RPM is no longer a constant and varies widely or natural frequencies are changing: there is a need for a wide range vibration reduction device.
In this paper, a translational adaptive electromagnetic tuned vibration absorber (ETVA) is described where its natural frequency is varied using electronics. The ETVA is modeled and its simulation results correlate very well with experimental results. Later, this concept is used to develop a torsional tuned vibration absorber (TTVA) device. The electromagnetic TTVA can be attached to rotating equipment to control torsional vibrations. The electromagnetic TTVA adapts itself and controls the torsional vibrations as and when the RPM varies. Here in this paper, the rotating equipment and the electromagnetic TTVA are modeled. Analysis results indicate that the torsional vibration of rotating equipment can be easily controlled using this newly developed electromagnetic TTVA.
Side Impact Performance of Structurally Integrated Space Frame Doors
Authors: El-Sayed Mohamed E. M. 
Published: October 2013

About 8,000 fatalities and 69,000 serious to critical injuries occur in side impacts every year in U.S. Severe head trauma and spinal cord injuries are directly related to the extent of penetration or intrusion into the occupant’s space. In side impact crashes, lack of a strong side structure reduces the ability of the impacted vehicle to safely respond to the impacting vehicle or object. This structural weakness causes massive injuries to the occupant due to the excessive side intrusion. With the increasing number of larger and heavier vehicle such as SUVs on the road and the higher probability of being impacted by one, the need for side impact protective measures is becoming more critical.
The main difficulty in designing for side impact collisions is the limited structure and energy absorption zone between the impacting vehicle and the impacted occupant. This paper discusses side impact occupant safety of space frame doors and their integration with vehicle body structure. The main objective is to explore the effect of space frame doors utilization on side intrusion and occupant response criteria. To study the effect, side impact crash tests of un-integrated and integrated space frame doors, with the vehicle body structure, are conducted.
Architectural and Performance Integration of Hybrid Vehicles
Authors: El-Sayed Mohamed E. M. 
Published: October 2013

With the development of advanced propulsion systems such as hybrid the need for new system integration, development, and validation strategies increases. Traditional methods for development and validation of vehicles focused mostly on the mechanical systems. Considering that the majority of architectural and performance issues arise from the different interfaces, the complexity increases when these interfaces are of different types such as electro-mechanical and electro-chemical etc.
In this paper, some architectural and performance integration issues arising from vehicle electrification and the development of advanced propulsion systems will be studied. To demonstrate the issues and illustrate their impact on the vehicle development process some hybrid system development examples are discussed.
Aeroderivative Combined Heat and Power Fundementals and Applications
Authors: DiCampli James 
Published: October 2013

Combined heat and power (CHP), is an application that utilizes the exhaust heat generated from a gas turbine and converts it into a useful energy source for heating & cooling, or additional electric generation in combined cycle configurations. Compared to simple-cycle plants with no heat recovery, CHP plants emit fewer greenhouse gasses and other emissions, while generating significantly more useful energy per unit of fuel consumed. Clean plants are easier to permit, build and operate.
Because of these advantages, Aeroderivative gas turbines will be a major part of global CHP growth, particularly in China. In order to improve energy efficiency and reduce CO2 emissions, China is working to build ∼1000 new plants of Natural Gas Distributed Energy System (NG-DES) in the next five years. These plants will replace conventional coal-fired plants with combined cooling, heating and power (CCHP) systems. China power segments require an extensive steam supply for cooling, heating and industrial process steam demands, as well as higher peak loads due to high population densities and manufacturing growth rates.
GE Energy Aero recently entered the CCHP segment in China, and supported the promotion of codes and standards for NG-DES policy, and is developing optimized CCHP gas turbine packages to meet requirements. This paper reviews those policies and requirements, and presents technical case studies on CCHP applications. Appendix B highlights China’s draft “Guidance Opinions on Developing Natural-Gas Distributed Energy.”
Horizontal Two Phase Flow Regime Identification: Comparison of Pressure Signature, Electrical Capacitance Tomography (ECT) and High Speed Visualization
Authors: Kreitzer Paul J. , Hanchak Michael , Byrd Larry 
Published: October 2013

Understanding the behavior of transient two phase refrigerant flow is an important aspect of implementing vapor compression systems in future aerospace applications. Pressure drop and heat transfer coefficient are important parameters that guide the design process, and are influenced by flow regime. Published two phase flow models rely heavily on a priori knowledge of the current two phase flow conditions including flow regime. Additional complications arise when applying published correlations to a range of systems because each correlation is based on a specific set of experimental conditions, including working fluid, flow orientation, channel size, and channel shape. Non-intrusive measurement techniques provide important advantages while measuring the behavior of two phase flow systems.
A two phase flow experimental test rig has been developed at the Air Force Research Laboratory, providing a closed loop refrigeration system capable of producing flow regimes from bubbly through annular flow. Two phase flow is produced by pumping subcooled R134a through a heat exchanger with 40 minichannels into an adiabatic transparent fused quartz observation channel with a hydraulic diameter of 7 mm. Refrigerant mass flux is varied from 100–400 kg/m2s with a heat flux from 0–15.5 W/cm2. Temperatures ranged from 18–25 °C and pressures between 550–750 kPa. The data from high speed pressure transducers were analyzed using standard signal processing techniques to identify the different flow regimes. Initial results indicate that different flow regimes can be identified from their pressure signature. In addition, real-time void fraction measurements were taken using Electrical Capacitance Tomography (ECT). This paper describes the process behind ECT systems used to measure two phase flow conditions. Comparisons with high speed video assess the accuracy of ECT measurements in identifying various two phase flow conditions. Results indicate variations between ECT and high speed images, however, enough information is provided to create flow pattern maps and regime identification for different superficial vapor and liquid velocities.
Coupled Direct Numerical Simulation and Experimental Approach to Develop Framework for Nano Fluids
Authors: Sloan Gregory , Feng Zhi-Gang , Bhaganagar Kiran , Banerjee Debyjoti 
Published: October 2013

Nanofluids are considered to be attractive as heat transfer fluids (HTF) and thermal energy storage (TES) for concentrated solar power (CSP) applications. Solvents doped with relatively low concentrations of nanoparticles (with diameters up to 100 nm) are termed as nanofluids. Numerical models for exploring the forces experienced by the nanoparticles are needed in order to ascertain the transport processes responsible for the anomalous material properties of the nanofluids that are observed in experimental measurements.
In this study a multiscale approach to modeling the forces acting on these particles was performed and the dynamics of transient nanoparticle agglomeration have been explored. The validity of the multiscale approach is demonstrated by examining a pair of nanoparticles in a fluid. The force interactions due to the presence of the electric double layer (EDL) were identified as a significant factor in determining the propensity for agglomerative of the nanoparticles. Simulations were performed to demonstrate the clustering and agglomeration of an ensemble of nanoparticles. The simulation results provide an estimate for the time scale for the agglomeration and the resultant structure of the agglomerated ensemble of nanoparticles. Subsequently simulations were performed using this numerical model corresponding to the available experimental data in the literature. The predictions from the numerical simulations show that the change in zeta potential (determined in part by the pH of the solvent phase) is a crucial parameter that affects the level of agglomeration of the nanoparticles. Finally, the numerical scheme is extended for performing true 3-D simulation. This approach is more sophisticated than the contemporary schemes that are reported in the literature that project 3-D forces on to a 2-D plane.
Determination of Two-Phase Flow Void Fraction of R600a in a Horizontal Smooth Tube
Authors: Ağra Özden , Demir Hakan , Atayılmaz Ş. Özgür , Yurtseven Ahmet , Dalkılıç A. Selim , Wongwises Somchai 
Published: October 2013

In this paper, the void fraction of alternative refrigerant R600a flowing inside horizontal tube is determined by means of an experimental technique, well known correlations in the literature and a generalized neural network analysis. The horizontal tube is made from smooth glass tubing of 4 mm inner diameter. The test runs are done at average saturated condensing temperatures between 30 and 40 °C while the average qualities and the mass fluxes are between 0.45–0.91 and 68.5–138.1 kg m-2s-1 respectively. The flow regime determination inside the tube is performed by means of sight glasses placed at the inlet and outlet sections of the test section, used for in-tube condensation tests, virtually. An image processing technique, performed by means of a high speed camera, is used to determine the void fractions of stratified and annular condensing flow of R600a experimentally. The void fractions are determined using relevant measured data together with 11 different void fraction models and correlations reported in the open literature analytically. Artificial neural network (ANN) analysis is developed to determine the void fractions numerically. For this aim, mass flow rate, average vapor quality, saturation temperature, liquid and vapor densities, liquid and vapor dynamic viscosities and surface tension are selected as the input parameters, while the void fraction is selected as the output.
Three-layer network is used for predicting the void fraction. The number of the neurons in the hidden layer was determined by a trial and error process evaluating the performance of the network and standard sensitivity analysis. The measured void fraction values are found to be in good agreement with those from ANN analysis and correlations in the literature. It is also seen that the trained network are more predictive on the determination of void fraction than most of the investigated correlations.
Bond Strength Models for Adhesively Bonded Flip-Chip Interconnects
Authors: Sinha K. , Dasgupta A. , Caers J. 
Published: October 2013

This paper investigates the role of gold-to-gold interfacial metallurgical bonding on the bond strength of adhesively bonded flip-chip interconnects in microelectronic assemblies. [44] dealt with experimental investigation of the effect of bonding parameters on Au-Au interfacial bond strength. One of the major conclusions in [44] was that interfacial creep deformation closely correlated with the measured evolution of bond strength over time. This study presents a viscoplastic finite element analysis to capture the physical creep mechanisms that drive the development of this strength, so that the effect of the system architecture and bonding parameters can be effectively quantified. Based on the studies in literature [42, 43], the strength is assumed to depend on the area of the contact “a-spots,” which are defined here as the area over which the interfaces come into intimate, atomistically flat contact.
The most important inputs to the finite element model consist of (i) interfacial geometry (with special emphasis on the surface roughness topology); (ii) viscoplastic mechanical properties of gold; and (iii) bonding parameters (force, temperature and time). The viscoplastic constitutive properties for gold are obtained partly from experiments conducted in this study and partly from the existing literature. The model inputs are parametrically varied in a systematic way within the design space, to obtain the variability expected in the bond strength. The simulation results are captured in a response surface model that can predict bond strength for a given set of fabrication conditions. The response surface model thus serves as a prediction tool critical for optimizing the interconnect strength and the durability of adhesively bonded flip chip assemblies.
Time-Efficient Method for Test-Based Optimization of Technical Systems Using Physical Models
Authors: Albers Albert , Schwarz Alexander , Behrendt Matthias , Hettel Rolf 
Published: October 2013

Technical systems must be continuously improved so that they can remain competitive on the market. Also, the time-to-market is an important factor for the success of a product. To achieve this goal, new methods and processes are needed. Especially the testing and calibration are important phases in the development process.
This paper introduces a method, which helps to reduce the time effort while increasing the quality of the calibration process. The basic idea is to use measured test data to parameterize a physical (or mostly physical) model structure to create adequate models for the optimization. The main advantage of the method is the reduction of test effort because the number of variations of the design parameter is one, or extremely decreased (depending on the system). Another advantage is that the uncertainty and the limit of the model can be quantified more accurately compared to common approaches based on non-physical model structures. These normally use artificial neuronal networks (ANN) or polynomial approaches for the test-based optimization.
This contribution illustrates the method by using the example of the calibration process of a double clutch gearbox (DCT) regarding energy efficiency and drivability on a roller test bench. First step is the test planning and test execution. In this step the method calculates the optimal execution order of the measuring points. In this example 81% timesaving can be achieved compared to the equivalent on the test track. The second step is the automated generation of the simulation model. In this step the unknown parameters of the model structure are calculated. The contribution shows different approaches for the identification of non-linear systems. In the last step the model is used to perform the optimization of the design parameters.
Anthropogenic Heat Release Into the Environment
Authors: Wong Kaufui V. , Dai Yading , Paul Brian 
Published: October 2013

This work is intended to systematically study an inventory of the anthropogenic heat produced. This research strives to present a better estimate of the energy generated by humans and human activities, and compare this estimate to the significant energy quantity with respect to climate change.
Because the Top of Atmosphere (TOA) net energy flux was found to be 0.85±0.15 W/m2 the planet is out of energy balance, as studied by the group from NASA in 2005. The Earth is estimated to gain 431 TW from this energy imbalance. This number is the significant heat quantity to consider when studying global climate change, and not the 78,300 TW, the absorbed part of the primary solar radiation reaching the Earth’s surface, as commonly cited and used at present in the literature.
Based on energy supplied to the boilers (in the Rankine cycle) of at least 13 TW, body energy dissipated by 7 billion people and their domestic animals, the value of the total world anthropogenic heat production rate is 15.26 TW or 3.5% of the energy gain by the Earth. Based on world energy consumption and the energy dissipated by 7 billion people and their domestic animals, the value of the total world anthropogenic heat production rate is 19.7 TW or about 5% of the energy gain by the Earth. These numbers are significantly different from 13 TW. More importantly, the figures are 3.5 to 5% of the net energy gained by the Earth, and hence significant. The quantity is not 0.017% of the absorbed part of the main solar radiation reaching the Earth’s surface and negligible.
Electrostatically Actuated Compliant Microvalve
Authors: Dankovic Tatjana , Feinerman Alan 
Published: October 2013

We present an electrostatically operated normally opened microvalve for gas flow control. The valve is made of thermoplastic materials and uses a new fabrication method. The voltage required to close the 0.9 mm wide microvalve was ∼350 V for fluid (air) pressure ∼1kPa.
A new technique [1] has been developed to fabricate valves, micromixer [2, 3] and other microfluidic structures, by patterned welding of compliant thermoplastic films using Universal Laser System CO2 laser. The normally opened valve is electrostatically actuated by applying the voltage on its metalized thermoplastic surfaces. There is no movable membrane or cantilever which closes the fluid path as reported in many other electrostatic microvalves. The walls of the channel collapse toward each other when sufficient voltage is applied, thus effectively closing the fluid path. The material used is 1.4 μm thick Mylar™ sheets (DuPont) coated on one side with ∼10nm of gold.