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Full-Text Articles in Mechanical Engineering

Gas Turbine, Vijaya Krushna Varma Mr Nov 2010

Gas Turbine, Vijaya Krushna Varma Mr

VIJAYA KRUSHNA VARMA Mr

Varma designed ultra modern and high efficiency turbines which can use gas, steam or fuels as feed to produce electricity or mechanical work for wide range of usages and applications in industries or at work sites. Varma turbine engines can be used in all types of vehicles. These turbines can also be used in aircraft, ships, battle tanks, dredgers, mining equipment, earth moving machines etc, Salient features of Varma Turbines. 1. Varma turbines are simple in design, easy to manufacture, easy to operate and maintain. 2. Varma turbines are less expensive. 3. Varma turbines have a great power to weight …


Water Turbine, Vijaya Krushna Varma Mr Nov 2010

Water Turbine, Vijaya Krushna Varma Mr

VIJAYA KRUSHNA VARMA Mr

Varma designed ultra modern and high efficiency turbines which can use gas, steam or fuels as feed to produce electricity or mechanical work for wide range of usages and applications in industries or at work sites. Varma turbine engines can be used in all types of vehicles. These turbines can also be used in aircraft, ships, battle tanks, dredgers, mining equipment, earth moving machines etc, Salient features of Varma Turbines. 1. Varma turbines are simple in design, easy to manufacture, easy to operate and maintain. 2. Varma turbines are less expensive. 3. Varma turbines have a great power to weight …


Modeling Large Modern Fossil-Fueled Steam-Electric Power Plant And Its Coordinated Control System For Power System Dynamic Analysis, Lin Gao Oct 2010

Modeling Large Modern Fossil-Fueled Steam-Electric Power Plant And Its Coordinated Control System For Power System Dynamic Analysis, Lin Gao

Lin Gao

Fossil-fueled steam-electric power plants have many outstanding advantages and are still one of the main power types in the world especially for non-European countries. The classic mathematic models are designed for traditional hydraulic governing steam turbine units. Single turbine and its control system models are used wildly for dynamic analysis in power system. Digital electro-hydraulic (DEH) control systems and coordinated control systems (CCS) are used in most of the modern large power boiler-turbine units. They are key elements in the operation of the power station and have great impact on the system responses to the frequency or load disturbances. But …


Ultra-Thin-Film Aln Contour-Mode Resonators For Sensing Applications, Matteo Rinaldi, Chiara Zuniga, Gianluca Piazza Sep 2010

Ultra-Thin-Film Aln Contour-Mode Resonators For Sensing Applications, Matteo Rinaldi, Chiara Zuniga, Gianluca Piazza

Matteo Rinaldi

This paper reports on the design and experimental verification of a new class of ultra-thin-film (250 nm) aluminum nitride (AlN) microelectromechanical system (MEMS) contour mode resonators (CMRs) suitable for the fabrication of ultra-sensitive gravimetric sensors. The device thickness was opportunely scaled in order to increase the mass sensitivity, while keeping a constant frequency of operation. In this first demonstration the resonance frequency of the device was set to 178 MHz and a mass sensitivity as high as 38.96 KHz⋅μm2/fg was attained. This device demonstrates the unique capability of the CMR-S technology to decouple resonance frequency from mass sensitivity.


Absolute Ground-State Nitrogen Atom Density In A N2/Ch4 Late Afterglow: Talif Experiments And Modelling Studies, Et. Es-Sebbar, M.-C. Gazeau, Y. Benilan, A. Jolly, C D. Pintassilgo Aug 2010

Absolute Ground-State Nitrogen Atom Density In A N2/Ch4 Late Afterglow: Talif Experiments And Modelling Studies, Et. Es-Sebbar, M.-C. Gazeau, Y. Benilan, A. Jolly, C D. Pintassilgo

Dr. Et-touhami Es-sebbar

Following a first study on a late afterglow in flowing pure nitrogen post discharge, we report new two-photon absorption laser-induced fluorescence (TALIF) measurements of the absolute ground-state atomic nitrogen density N(4S) and investigate the influence of methane introduced downstream from the discharge by varying the CH4 mixing ratio from 0% up to 50%. The N (4S) maximum density is about 2.2 × 1015 cm−3 in pure N2 for a residence time of 22 ms and does not change significantly for methane mixing ratio up to ~15%, while above, a drastic decrease is observed. The influence of the residence time has …


Experimental And Theoretical Studies On Nitrogen Plasma And Methane Photolysis: Implications For Laboratory Simulations Of Titan’S Atmosphere, M-C. Gazeau, Y. Benilan, E. Arzoumanian, Et. Es-Sebbar, A. Jolly Jul 2010

Experimental And Theoretical Studies On Nitrogen Plasma And Methane Photolysis: Implications For Laboratory Simulations Of Titan’S Atmosphere, M-C. Gazeau, Y. Benilan, E. Arzoumanian, Et. Es-Sebbar, A. Jolly

Dr. Et-touhami Es-sebbar

No abstract provided.


Spectroscopic Studies Applied To Uvis Observations Of Titan, Y. Benilan, F. Capalbo, Et. Es-Sebbar, N. Fray, A. Jolly, M-C. Gazeau, J-C. Guillemin, M. Schwell Jul 2010

Spectroscopic Studies Applied To Uvis Observations Of Titan, Y. Benilan, F. Capalbo, Et. Es-Sebbar, N. Fray, A. Jolly, M-C. Gazeau, J-C. Guillemin, M. Schwell

Dr. Et-touhami Es-sebbar

No abstract provided.


Talif Investigation And Modelling Of The Absolute N(4s) Density In A N2-Ch4 Late Afterglow, C.D. Pintassilgo, Et. Es-Sebbar, Y. Benilan, M-C. Gazeau, A. Jolly Jul 2010

Talif Investigation And Modelling Of The Absolute N(4s) Density In A N2-Ch4 Late Afterglow, C.D. Pintassilgo, Et. Es-Sebbar, Y. Benilan, M-C. Gazeau, A. Jolly

Dr. Et-touhami Es-sebbar

The purpose of the present work is the experimental and numerical study of the absolute ground-state nitrogen atoms density N(4S) in the late afterglow of a pure N2 flowing microwave discharge in which different amounts of CH4 have been injected at 25 cm downstream from the nitrogen discharge. The absolute N(4S) concentrations have been measured using Two-photon Absorption Laser-Induced Fluorescence (TALIF), while a detailed kinetic model has been developed to simulate both the discharge and the post-discharge regions. Theoretical predictions are then compared to experimental measurements.


Combined Experimental And Theoretical Studies On Methane Photolysis At 121.6 Nm And 248 Nm- Implications On A Program Of Laboratory Simulations Of Titan’S Atmosphere, C. Romanzin, E. Arzoumanian, Et. Es-Sebbar, A. Jolly, S. Perrier, M.-C. Gazeau, Y. Bénilan Jul 2010

Combined Experimental And Theoretical Studies On Methane Photolysis At 121.6 Nm And 248 Nm- Implications On A Program Of Laboratory Simulations Of Titan’S Atmosphere, C. Romanzin, E. Arzoumanian, Et. Es-Sebbar, A. Jolly, S. Perrier, M.-C. Gazeau, Y. Bénilan

Dr. Et-touhami Es-sebbar

Methane is, together with N2, the main precursor of Titan’s atmospheric chemistry. In our laboratory, we are currently developing a program of laboratory simulations of Titan’s atmosphere, where methane is intended to be dissociated by multiphotonic photolysis at 248 nm. A preliminary study has shown that multiphotonic absorption of methane at 248 nm is efficient and leads to the production of hydrocarbons such as C2H2 (Romanzin et al., 2008). Yet, at this wavelength, little is known about the branching ratios of the hydrocarbon radicals (CH3, CH2 and CH) and their following photochemistry. This paper thus aims at investigating methane photochemistry …


Temperature-Dependent Photoabsorption Cross-Section Of Cyano-Diacetylene In The Vacuum Uv, N. Fray, Y. Bénilan, M.-C. Gazeau, A. Jolly, M. Schwell, E. Arzoumanian, Et. Es-Sebbar, T. Ferradaz, J.- C. Guillemin Jun 2010

Temperature-Dependent Photoabsorption Cross-Section Of Cyano-Diacetylene In The Vacuum Uv, N. Fray, Y. Bénilan, M.-C. Gazeau, A. Jolly, M. Schwell, E. Arzoumanian, Et. Es-Sebbar, T. Ferradaz, J.- C. Guillemin

Dr. Et-touhami Es-sebbar

Using synchrotron radiation as a tunable VUV light source, we have measured, for the first time, the absolute photoabsorption cross sections of HC5N with a spectral resolution of 0.05 nm in the region between 80 and 205 nm from 233 to 298 K. The measured cross sections are used to predict the HC5N photodestruction rate in the solar system and to model a transmission spectrum in Titan's atmosphere. Comparing the latter with that acquired by the Ultraviolet Imaging Spectrograph on board the Cassini spacecraft, we have determined an upper limit of 2.7 × 10−5 on the HC5N abundance at 1100 …


Analysis Of Power System Frequency Responses With Hydro Turbines Incorporating Load Shedding, Lin Gao Jun 2010

Analysis Of Power System Frequency Responses With Hydro Turbines Incorporating Load Shedding, Lin Gao

Lin Gao

As shown in many recent works, the load-frequency behavior can be represented by system frequency response models especially for an islanding process. In this paper, a frequency response model incorporating an under-frequency load-shedding scheme is presented for islanding power system simulations. The model was applied for a realistic power system with hydro power generators. The hydro power generator model parameters were identified and similar responses were observed between the simulations and the accident records. The simulation results showed disadvantages of the primary frequency control systems of hydro power generators at the beginning of the load disturbances. The power system stability …


Determination Of Material Emission Signatures By Ptr-Ms And Their Correlations With Odor Assessments By Human Subjects, Kwanghoon Han Apr 2010

Determination Of Material Emission Signatures By Ptr-Ms And Their Correlations With Odor Assessments By Human Subjects, Kwanghoon Han

Kwanghoon Han

The objectives of this study were to determine volatile organic compound (VOC) emission signatures of nine typical building materials by using proton transfer reaction-mass spectrometry (PTR-MS) and to explore the correlation between the PTR-MS measurements and the measurements of acceptability by human subjects. VOC emissions from each material were measured in a 50-l small-scale chamber. Chamber air was sampled by PTR-MS to determine emission signatures. Sorbent tube sampling and TD-GC/MS analysis were also performed to identify the major VOCs emitted and to compare the resulting data with the PTR-MS emission signatures. The data on the acceptability of air quality assessed …


Conference Proceedings 3rd International Scientific Conference On “Energy Systems With It” At Alvsjö Fair In Association With Energitinget March 16-17 2010, Dr. Erik Dahlquist, Dr. Jenny Palm Mar 2010

Conference Proceedings 3rd International Scientific Conference On “Energy Systems With It” At Alvsjö Fair In Association With Energitinget March 16-17 2010, Dr. Erik Dahlquist, Dr. Jenny Palm

Dr. Erik Dahlquist

2010 “The Energiting” is performed for the 12th time. The International Scientific conference is arranged for the 3rd time. The organisers are Swedish Energy Agency, Mälardalen University and the Research School for Energy Systems with LiU, KTH, UU and CTH. The first topic will be “Energy systems” covering use of renewable energy sources, energy conversion and process efficiency improvement with new technologies, as well as societal aspects of the introduction of new technologies. The second topic is “Energy and IT”. This covers energy and load management, interaction between production, distribution and “consumption”, usage of data for decision support and control, …


A Microflow Cytometer On A Chip, Joel P. Golden, Jason Kim, George P. Anderson, Nicole N. Hashemi, Peter J. Howell, Frances S. Ligler Feb 2010

A Microflow Cytometer On A Chip, Joel P. Golden, Jason Kim, George P. Anderson, Nicole N. Hashemi, Peter J. Howell, Frances S. Ligler

Nastaran Hashemi

A rapid, automated, multi-analyte Microflow Cytometer is being developed as a portable, field-deployable sensor for onsite diagnosis of biothreat agent exposure and environmental monitoring. The technology relies on a unique method for ensheathing a sample stream in continuous flow past an interrogation region where optical fibers provide excitation and collect emission. This approach efficiently focuses particles in the interrogation region of the fluidic channel, avoids clogging and provides for subsequent separation of the core and sheath fluids in order to capture the target for confirmatory assays and recycling of the sheath fluid. Fluorescently coded microspheres provide the capability for highly …


The Carillon And Its Haptic Signature : Modeling The Changing Force-Feedback Constraints Of A Musical Instrument For Haptic Display, Mark Havryliv, F. Geiger, M. Gurtler, Fazel Naghdy, Greg Schiemer Feb 2010

The Carillon And Its Haptic Signature : Modeling The Changing Force-Feedback Constraints Of A Musical Instrument For Haptic Display, Mark Havryliv, F. Geiger, M. Gurtler, Fazel Naghdy, Greg Schiemer

Greg Schiemer

The carillon is one of the few instruments that elicits sophisticated haptic interaction from amateur and professional players alike. Like the piano keyboard, the velocity of a player’s impact on each carillon key, or baton, affects the quality of the resultant tone; unlike the piano, each carillon baton returns a different force-feedback. Force-feedback varies widely from one baton to the next across the entire range of the instrument and with further idiosyncratic variation from one instrument to another. This makes the carillon an ideal candidate for haptic simulation. The application of synthesized forcefeedback based on an analysis of forces operating …


100nm Thick Aluminum Nitride Based Piezoelectric Nano Switches Exhibiting 1mv Threshold Voltage Via Body-Biasing, Nipun Sinha, Zhijun Guo, Valeriy Felmetsger, Gianluca Piazza Dec 2009

100nm Thick Aluminum Nitride Based Piezoelectric Nano Switches Exhibiting 1mv Threshold Voltage Via Body-Biasing, Nipun Sinha, Zhijun Guo, Valeriy Felmetsger, Gianluca Piazza

Nipun Sinha

This paper reports on the first demonstration of aluminum nitride (AlN) piezoelectric logic switches that were fabricated with ultra-thin (100nm) AlN films and exhibit a 1 mV threshold voltage via the body-biasing scheme. The application of a relatively low (< 6 V) fixed potential to the body terminal of a 4-terminal switch has resulted in a repeatable threshold voltage of 1 mV. The nano-switch has been cycled to > 109 cycles and, although the contact resistance was found to be high (~ 1 MΩ), the nano-films have functioned throughout to show high piezoelectric nano-film reliability.


Super-High-Frequency Two-Port Aln Contour-Mode Resonators For Rf Applications, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza Dec 2009

Super-High-Frequency Two-Port Aln Contour-Mode Resonators For Rf Applications, Matteo Rinaldi, Chiara Zuniga, Chengjie Zuo, Gianluca Piazza

Matteo Rinaldi

This paper reports on the design and experimental verification of a new class of thin-film (250 nm) super-high-frequency laterally-vibrating piezoelectric microelectromechanical (MEMS) resonators suitable for the fabrication of narrow-band MEMS filters operating at frequencies above 3 GHz. The device dimensions have been opportunely scaled both in the lateral and vertical dimensions to excite a contour-extensional mode of vibration in nanofeatures of an ultra-thin (250 nm) AlN film. In this first demonstration, 2-port resonators vibrating up to 4.5 GHz have been fabricated on the same die and attained electromechanical coupling, kt2, in excess of 1.5%. These devices are employed to synthesize …


Demonstration Of Low Voltage And Functionally Complete Logic Operations Using Body-Biased Complementary And Ultra-Thin Aln Piezoelectric Mechanical Switches, Nipun Sinha, Timothy S. Jones, Zhijun Guo, Gianluca Piazza Dec 2009

Demonstration Of Low Voltage And Functionally Complete Logic Operations Using Body-Biased Complementary And Ultra-Thin Aln Piezoelectric Mechanical Switches, Nipun Sinha, Timothy S. Jones, Zhijun Guo, Gianluca Piazza

Nipun Sinha

This paper reports, for the first time, on the demonstration of low voltage and functionally complete logic elements (NAND and NOR) implemented by using body-biased complementary and ultra-thin (250 nm thick) Aluminum Nitride (AlN) based piezoelectric mechanical switches. This work presents, firstly, the importance of scaling AlN films for the demonstration of ultra-thin AlN switches and, secondly, the implementation of a new actuation scheme based on body biasing to lower the switch threshold voltage. Four of these ultra-thin switches were connected together to synthesize functionally complete MEMS logic gates (NAND and NOR) with a ± 2V swing and a body-bias …