VLSI DESIGN OF PIPELINED ADC WITH WIDE RANGE OPERATING TEMPERATURE FOR WAVE APPLICATIONS

2017 ◽  
Vol 6 (2) ◽  
pp. 13
Author(s):  
P LOKESH ◽  
U. SOMALATHA ◽  
S. CHANDANA ◽  
◽  
◽  
...  
Keyword(s):  
Operating Temperature ◽  
Vlsi Design ◽  
Pipelined Adc ◽  
Wide Range

scholarly journals Flux-Reducing Tendency of Pd-Based Membranes Employed in Butane Dehydrogenation Processes

Membranes ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 291 ◽  
Author(s):  
Thijs A. Peters ◽  
Marit Stange ◽  
Rune Bredesen
Keyword(s):  
Competitive Adsorption ◽  
Prolonged Exposure ◽  
Hydrogen Permeation ◽  
State Of The Art ◽  
Operating Temperature ◽  
Operating Conditions ◽  
Maximum Temperature ◽  
Hydrogen Flux ◽  
Membrane Performance ◽  
Wide Range

We report on the effect of butane and butylene on hydrogen permeation through thin state-of-the-art Pd–Ag alloy membranes. A wide range of operating conditions, such as temperature (200–450 °C) and H2/butylene (or butane) ratio (0.5–3), on the flux-reducing tendency were investigated. In addition, the behavior of membrane performance during prolonged exposure to butylene was evaluated. In the presence of butane, the flux-reducing tendency was found to be limited up to the maximum temperature investigated, 450 °C. Compared to butane, the flux-reducing tendency in the presence of butylene was severe. At 400 °C and 20% butylene, the flux decreases by ~85% after 3 h of exposure but depends on temperature and the H2/butylene ratio. In terms of operating temperature, an optimal performance was found at 250–300 °C with respect to obtaining the highest absolute hydrogen flux in the presence of butylene. At lower temperatures, the competitive adsorption of butylene over hydrogen accounts for a large initial flux penalty.

scholarly journals Higher Operating Temperature IR Detectors of the MOCVD Grown HgCdTe Heterostructures

2020 ◽  
Vol 49 (11) ◽  
pp. 6908-6917
Author(s):  
P. Madejczyk ◽  
W. Gawron ◽  
A. Kębłowski ◽  
K. Mlynarczyk ◽  
D. Stępień ◽  
...  
Keyword(s):  
Infrared Detectors ◽  
Diffusion Processes ◽  
Operating Temperature ◽  
Chemical Vapour ◽  
Dual Band ◽  
Theoretical Modelling ◽  
Organic Chemical ◽  
Ir Detectors ◽  
Wide Range ◽  
Technology Improvement

Abstract This paper summarizes progress in metal organic chemical vapour deposition (MOCVD) technology achieved in recent years at the Institute of Applied Physics, Military University of Technology and VIGO System S.A. MOCVD with a wide range of composition and donor/acceptor doping and without post-growth annealing is a very convenient tool for the deposition of HgCdTe epilayers used for uncooled infrared detectors. Particular attention is focused on: surface morphology improvement, doping issues, diffusion processes during growth study, substrate issues, crystallographic orientation selection. In this respect, MOCVD technology improvement influencing IR detector parameters is shown. CdTe buffer layer deposition allows HgCdTe heterostructure growth on GaAs substrates. Theoretical modelling using APSYS platform supports designing and better understanding of the carrier transport mechanism in detector’s structures. Secondary ion mass spectrometry profiles allows to compare projected and obtained structures and revealed diffusion processes of the elements. A wide range of different types of infrared detectors operating at high operating temperature conditions has been constructed: photoresistors, non-equilibrium photodiodes, dual-band photodiodes, barrier and multiple detectors. The methodical research efforts contributed to the time constant reduction are important in many detector applications. Future challenges and prospects are also discussed.

Creep Characterization of Ni-Based Superalloy IN-792 Using the 4- and 6-θ Projection Method

2013 ◽  
Vol 136 (1) ◽  
Author(s):  
S. A. Sajjadi ◽  
M. Berahmand ◽  
A. Rezaee-Bazzaz
Keyword(s):  
Projection Method ◽  
High Strain ◽  
Operating Temperature ◽  
Constant Load ◽  
Least Square ◽  
Creep Tests ◽  
Wide Range ◽  
Creep Curves ◽  
Projection Techniques

This paper studies the accuracy of a technique which is capable of predicting and modeling a wide range of creep life in Ni-based superalloys. The θ-projection method was applied to characterize the creep behavior of the Ni-based superalloy IN-792 at 800 °C. Constant load creep tests have been carried out over a wide range of loads at the constant operating temperature. Creep curves were fitted using either 4-θ or 6-θ equation by the use of a nonlinear least-square technique. The results showed that both 4- and 6-θ projection parameters revealed a good linearity as a function of stress. Comparison of experimental creep curves with those predicted using both of the utilized θ-projection techniques showed that the techniques fit the experimental data at high strain values very well while the 6-θ approach describes much better the creep curves at low strain region.

Anand Viscoplasticity Model for the Effect of Aging on Mechanical Behavior of SAC305 Operating at High Strain Rate and High Temperature

2015 ◽  
Author(s):  
Pradeep Lall ◽  
Di Zhang ◽  
Jeff Suhling ◽  
David Locker
Keyword(s):  
High Temperature ◽  
High Strain ◽  
Operating Temperature ◽  
Uniaxial Stress ◽  
Strain Rates ◽  
High Strain Rates ◽  
Plastic Properties ◽  
Long Term Storage ◽  
Wide Range ◽  
Operational Life

Portable products such as smartphones and tablets stay in the powered on condition for a majority of their operational life during which time the device internals are maintained at higher than ambient temperature. Thus, it would be expected for interconnects in portable products to be at a temperature high than room temperature when subjected to accidental drop or shock. Furthermore, electronics in missile-applications may be subjected to high strain rates after prolonged period of storage often at high temperature. Electronics systems including interconnects may experience high strain rates in the neighborhood of 1–100 per sec during operation at high temperature. However, the material properties of SAC305 leadfree solders at high strain rates and high operating temperatures are scarce after long-term storage. Furthermore, the solder interconnects in simulation of product drop are often modeled using elastic-plastic properties or linear elastic properties, neither of which accommodate the effect of operating temperature on the solder interconnect deformation at high operating temperature. SAC305 solders have been shown to demonstrate the significant degradation of mechanical properties including the tensile strength and the elastic modulus after exposure to high temperature storage for moderate periods of time. Previously, Anand’s viscoplastic constitutive model has been widely used to describe the inelastic deformation behavior of solders in electronic components under thermo-mechanical deformation. Uniaxial stress-strain curves have been plotted over a wide range of strain rates (ε̇ = 10, 35, 50, 75 /sec) and temperatures (T = 25, 50, 75, 100, 125°C). Anand viscoplasticity constants have been calculated by non-linear fitting procedures. In addition, the accuracy of the extracted Anand constants has been evaluated by comparing the model prediction and experimental data.

Experimental Methodology to Characterize Mechanical Losses in Small Turbochargers

2010 ◽  
Author(s):  
Francisco Payri ◽  
Jose R. Serrano ◽  
Pablo Olmeda ◽  
Arlington Paez ◽  
Fabrice Vidal
Keyword(s):  
Heat Transfer ◽  
Operating Temperature ◽  
Mechanical Efficiency ◽  
Experimental Methodology ◽  
Current Work ◽  
Lubricating Oil ◽  
Heat Flows ◽  
Friction Power ◽  
Wide Range ◽  
Temperature Heat

Turbocharging and turbocharger phenomena have been studied by many authors covering a wide range of subjects. One of these subjects, and objective of this work, is mechanical losses due to friction. Current work presents a methodology to characterize mechanical losses in small size turbochargers. Such methodology is based on low and constant operating temperature values for the turbine, lubricating oil, and compressor. In this way, a quasi-adiabatic operation of the turbocharger is achieved which allows separating friction power from heat transfer. The experiments performed have covered variations in turbocharger speed, lubricating oil pressure and temperature. Heat flows between turbine and compressor has been maintained as reduced as possible by means of the experiment conditions. The results obtained show satisfactory correlation between mechanical efficiency of the studied turbocharger and non-dimensional magnitudes.

scholarly journals The Effect of Spool Displacement Control to the Flow Rate in the Piezoelectric Stack-Based Valve System Subjected to High Operating Temperature

Actuators ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 239
Author(s):  
Yu-Jin Park ◽  
Bo-Gyu Kim ◽  
Jun-Cheol Jeon ◽  
Dongsoo Jung ◽  
Seung-Bok Choi
Keyword(s):  
Pressure Drop ◽  
Flow Rate ◽  
Operating Temperature ◽  
Control Volume ◽  
Tracking Error ◽  
Displacement Control ◽  
Structural Part ◽  
Valve System ◽  
Wide Range ◽  
Experimental Apparatus

This work investigates the effect of spool displacement control of the piezoelectric stack actuator (PSA) based valve system on the flow motion of the pressure drop and flow rate. As a first step, the governing equations of the structural parts of the displacement amplifier and spool are derived, followed by the governing equation of the fluid part considering control volume and steady flow force. Then, an appropriate size of the valve is designed and manufactured. An experimental apparatus to control the spool displacement is set up in the heat chamber and tracking control for the spool displacement is evaluated at 20 °C and 100 °C by implementing a proportional-integral-derivative (PID) feedback controller. The tracking controls of the spool displacement associated with the sinusoidal and triangular trajectories are realized at 20 °C and 100 °C. It is demonstrated that the tracking controls for the sinusoidal and triangular trajectories have been well carried out showing the tracking error less than 3 μm at both temperatures. In addition, the flow motions for the pressure drop and the flow rate of the proposed valve system are experimentally investigated. It is identified from this investigation that both pressure drop and flow rate evaluated 20 °C have been decreased up to 18% at 100 °C. This result directly indicates that the temperature effect to control performance of the structural part and fluid part in the proposed PSA based valve system is different and hence careful attention is required to achieve the successful development of advanced valve systems subjected to a wide range of the operating temperature.

Dielectrics for Power Capacitors

2015 ◽  
Vol 2015 (CICMT) ◽  
pp. 000015-000020
Author(s):  
R. Karmazin ◽  
A. Koch ◽  
R. Matz ◽  
R. Männer ◽  
W. Metzger ◽  
...  
Keyword(s):  
High Temperature ◽  
Operating Temperature ◽  
Wide Spectrum ◽  
Dielectric Materials ◽  
Ceramic Composites ◽  
Atmospheric Plasma ◽  
Self Healing ◽  
Pure Alumina ◽  
Wide Range ◽  
Temperature Applications

High voltage capacitors are key components for transient storage and release of electrical energy in mobile electric devices, electric vehicles, stationary power systems and power transmission. Due to their high electric breakdown voltage, self-healing capability and affordability, polymer-based film capacitors are widely used, particularly those made from biaxially oriented polypropylene (BOPP). Their maximum operating temperature near 100°C, however, requires careful thermal management and oversize design. In high temperature applications well above 200°C, the preference shifts from organic to ceramic dielectric materials. Multilayer ceramic capacitors (MLCCs) are known for their excellent mechanical and thermal robustness, have a mature fabrication technology and have found a wide spectrum of applications in power electronic systems. Their higher cost level is frequently over-compensated by their robustness, a unique selling point particularly in high temperature applications. The present investigation deals with the suitability of various ceramic materials like mica, several high and low temperature sinterable tapes (HTCC, LTCC) as well as atmospheric plasma-sprayed (APS) alumina under such conditions. Aspects of manufacturability and component design are taken into account as well. Dielectric materials performance is particularly addressed by high temperature impedance spectroscopy up to several hundred °C to minimize further self heating of the components above the operating temperature. Although these materials, commercial as well as non-commercial ones, were originally developed for either electric or high temperature applications, the analysis suggests promising materials choices also in cases, when both requirements come together. Although dissipation factors obtained from capacitive test structures cover a wide range, capacitors made from pure alumina (HTCC) generally have lower dielectric loss at all temperatures than those made from glass-ceramic composites (LTCC). Quite diverse properties are obtained with APS alumina, which would represent a promising fabrication alternative due to the possible solid deposition on metal surfaces.

TECHALLOY 294

Alloy Digest ◽  
1975 ◽  
Vol 24 (10) ◽  
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Physical Properties ◽  
Temperature Coefficient ◽  
Nickel Alloy ◽  
Electrical Resistance ◽  
Operating Temperature ◽  
Heat Treating ◽  
Wide Range ◽  
Copper Nickel Alloy

Abstract TECHALLOY 294 is a copper-nickel alloy with constant electrical resistance over a wide range of temperatures. It is used widely in rheostats and controls where the maximum operating temperature does not exceed 1000 F. Its low temperature coefficient of electrical resistance and its stability make it highly useful in sizes for instruments and resistors. This datasheet provides information on composition, physical properties, elasticity, and tensile properties. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-301. Producer or source: Techalloy Company Inc..

Startup and Operation of a Supercritical Carbon Dioxide Brayton Cycle

2014 ◽  
Vol 136 (7) ◽  
Author(s):  
Eric M. Clementoni ◽  
Timothy L. Cox ◽  
Christopher P. Sprague
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Carbon Dioxide ◽  
Operating Temperature ◽  
Integrated System ◽  
Working Fluid ◽  
Brayton Cycle ◽  
Normal Operating ◽  
Wide Range ◽  
Startup Process ◽  
Supercritical Carbon

Bechtel Marine Propulsion Corporation (BMPC) is testing a supercritical carbon dioxide (S-CO2) Brayton system at the Bettis Atomic Power Laboratory. The 100 kWe integrated system test (IST) is a two shaft recuperated closed Brayton cycle with a variable speed turbine driven compressor and a constant speed turbine driven generator using S-CO2 as the working fluid. The IST was designed to demonstrate operational, control, and performance characteristics of an S-CO2 Brayton power cycle over a wide range of conditions. Initial operation of the IST has proven a reliable method for startup of the Brayton loop and heatup to normal operating temperature (570 °F). An overview of the startup process, including initial loop fill and charging, and heatup to normal operating temperature is presented. Additionally, aspects of the IST startup process which are related to the loop size and component design which may be different for larger systems are discussed.

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