PERFECT case studies demonstrating order of magnitude reduction in power consumption

2016 ◽  
Author(s):  
David K. Wittenberg ◽  
Edin Kadric ◽  
Andre DeHon ◽  
Jonathan Edwards ◽  
Jeffrey Smith ◽  
...  
Keyword(s):  
Power Consumption ◽  
Case Studies ◽  
Order Of Magnitude

Study on Flaw Acceptance Standard of ASME Code Sec. XI Based on Failure Probability

2004 ◽  
Author(s):  
Katsuyuki Shibata ◽  
Kunio Onizawa ◽  
YinSheng Li ◽  
Yasuhiro Kanto ◽  
Shinobu Yoshimura
Keyword(s):  
Case Studies ◽  
Failure Probability ◽  
Pressure Vessels ◽  
Aspect Ratios ◽  
Pressurized Thermal Shock ◽  
Asme Code ◽  
Order Of Magnitude ◽  
The Difference ◽  
Reactor Pressure

Based on the failure probability, the flaw acceptance standard of ASME Code Sec. XI is examined with some concerns weather the failure probability is uniform for flaws with various aspect ratios and failure frequencies are small enough. In this paper, the results of preliminary case studies are described on the failure probability of reactor pressure vessels (RPVs) with a surface flaw specified in Sec. XI. PFM code PASCAL was used for case studies. A PTS (Pressurized Thermal Shock) transient prescribed by NRC/EPRI PTS Benchmark Study was used as an applied load. Analysis results showed that the conditional failure probability of a RPV with an initial flaw of acceptable depth depends on the aspect ratio. In the case flaw shapes are close to semi-circular, the failure probability are higher than that of the cases aspect ration are less than 0.6 by one order of magnitude due to the difference of fracture behavior at the surface point. A case study for determining the acceptable flaws based on failure probability was also carried out.

Fluidized Bed Solar Collector

1988 ◽  
Vol 110 (4) ◽  
pp. 321-326 ◽  
Author(s):  
L. R. Glicksman ◽  
J. Azzola ◽  
J. Modlin
Keyword(s):  
Heat Transfer ◽  
Power Consumption ◽  
Fluidized Bed ◽  
Solar Collector ◽  
Effective Conductivity ◽  
Thermal Design ◽  
Low Density ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Order Of Magnitude

An air fluidized bed, contained in the wall cavity of an exterior building wall, forms the basis of a new solar collector design which is simpler than a water-cooled collector and has a thermal performance superior to that of an air-cooled collector. The fluidized bed serves as an intermediate heat transfer medium between a solar flux absorbed on the external building surface and a liquid thermal transfer loop. Fluidized beds yield heat-transfer coefficients an order of magnitude higher than single phase air flow. Low density particles are used in the bed to minimize power consumption. When defluidized, the bed acts as a good thermal insulator. Recent experimental results are presented for the heat-transfer coefficients of the immersed tubes, bounding walls, the effective conductivity of the bed, and the overall full-scale thermal design efficiency for various low density materials. Structural and power consumption performance is examined as well. An integrated fluidized bed solar collector design is proposed and compared with representative water and air collector designs.

scholarly journals Final Heat Treatment as a Possible Solution for the Improvement of Machinability of Pb-Free Brass Alloys

Metals ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 575 ◽  
Author(s):  
Anagnostis Toulfatzis ◽  
George Pantazopoulos ◽  
Constantine David ◽  
Dimitrios Sagris ◽  
Alkiviadis Paipetis
Keyword(s):  
Heat Treatment ◽  
Surface Roughness ◽  
Power Consumption ◽  
Chip Morphology ◽  
Lead Free ◽  
Maximum Height ◽  
Average Roughness ◽  
Treatment Conditions ◽  
Order Of Magnitude ◽  
Brass Alloys

Heat treatment was performed in order to improve the machinability of three lead-free extruded and drawn brasses, namely CuZn42 (CW510L), CuZn38As (CW511L), and CuZn36 (C27450), based on the concept of microstructural modification. The examined machinability criteria were the following: chip morphology, power consumption, cutting force, and surface roughness. All the above quality characteristics were studied in turning mode in “as received” and “heat treated” conditions for comparison purposes. The selected heat treatment conditions were set for CW510L (775 °C for 60 min), CW511L (850 °C for 120 min), and C27450 (850 °C for 120 min) lead-free brass alloys, according to standard specification and customer requirement criteria. The results are very promising concerning the chip breaking performance, since the heat treatment contributed to the drastic improvement of chip morphology for every studied lead-free brass. Regarding power consumption, heat treatment seems beneficial only for the CW511L brass, where a reduction by 180 W (from 1600 to 1420 W), in relation to the as-received condition, was achieved. Furthermore, heat treatment resulted in a marginal reduction by 10 N and 15 N in cutting forces for CW510L (from 540 to 530 N) and CW511L (from 446 to 431 N), respectively. Finally, surface roughness, expressed in terms of the average roughness value (Ra), seems that it is not affected by heat treatment, as it remains almost at the same order of magnitude. On the contrary, there is a significant improvement of maximum height (Rt) value of CW511L brass by 14.1 μm (from 40.1 to 26.0 μm), after heat treatment process performed at 850 °C for 120 min.

scholarly journals A Novel OTA Architecture Exploiting Current Gain Stages to Boost Bandwidth and Slew-Rate

Electronics ◽  
2021 ◽  
Vol 10 (14) ◽  
pp. 1638
Author(s):  
Francesco Centurelli ◽  
Riccardo Della Sala ◽  
Pietro Monsurrò ◽  
Giuseppe Scotti ◽  
Alessandro Trifiletti
Keyword(s):  
Power Consumption ◽  
Supply Voltage ◽  
Current Gain ◽  
Small Signal ◽  
Slew Rate ◽  
Large Signal ◽  
Current Mirrors ◽  
Order Of Magnitude ◽  
Unity Gain ◽  
Architecture And Design

A novel architecture and design approach which make it possible to boost the bandwidth and slewrate performance of operational transconductance amplifiers (OTAs) are proposed and employed to design a low-power OTA with top-of-class small-signal and large-signal figures of merit (FOMs). The proposed approach makes it possible to enhance the gain, bandwidth and slew-rate for a given power consumption and capacitive load, achieving more than an order of magnitude better performance than a comparable conventional folded cascode amplifier. Current mirrors with gain and a push–pull topology are exploited to achieve symmetrical sinking and sourcing output currents, and hence class-AB behavior. The resulting OTA was implemented using the 130 nm STMicroelectronics process, with a supply voltage of 1 V and a power consumption of only 1 µW. Simulations with a 200 pF load capacitance showed a gain of 92 dB, a unity-gain frequency of 141 kHz, and a peak slew-rate of 30 V/ms, with a phase margin of 80°, and good noise, PSRR and CMRR performance. The small-signal and large-signal current and power FOMs are the highest reported in the literature for comparable amplifiers. Extensive parametric and Monte Carlo simulations show that the OTA is robust against process, supply voltage and temperature (PVT) variations, as well as against mismatches.

Scaling the Vibrations of Water Pipes: Application to Industrial Case Studies

2006 ◽  
Author(s):  
P. Moussou ◽  
Th. Papaconstantinou ◽  
J. Cohen
Keyword(s):  
Case Studies ◽  
Scaling Law ◽  
Piping System ◽  
Centrifugal Pumps ◽  
Water Pipes ◽  
Single Hole ◽  
Piping Systems ◽  
Order Of Magnitude ◽  
The One ◽  
Globe Valve

A scaling approach for the vibrations of water pipes was proposed in the ASME PVP 2005 Conference. Using a single hole orifice in non-cavitating conditions as a reference noise source, the vibrations of a piping system were estimated on the basis of plane wave propagation for the acoustics, and on the basis of vibrating beams for the structure. The scaling of the velocity Power Spectral Density (PSD) of a pipe is then a function of the pressure drop of the device considered, of the inner and outer diameters of the pipe, of the flow velocity, of the support spacing and of the densities of steel and water. The present paper describes the application of the scaling approach to industrial case studies: velocity PSD were measured on a sample of piping systems with pressures varying from 3 to 100 bars, with flows varying from 30 to 1000 m3/h and with hydraulic powers varying from 10 to 200 kW. The sources of vibrations were orifices, globe valves and butterfly valves in turbulent or cavitating regimes, and centrifugal pumps operating at nominal or partial flow regimes. In most cases, the measured data match the scaling law based on the single hole orifice noise, as an order of magnitude. A closer look reveals that different sources of vibrations exhibit recognizable patterns; the partial flow regime of a centrifugal pump generates a velocity PSD different from the nominal regime, and the cavitation of a globe valve generates a velocity PSD very different from the one generated by the cavitation of a single hole orifice. Typical non-dimensional spectra are proposed for each type of noise generating device.

Statistical Simulations on Perceptron-Based Adders

2011 ◽  
pp. 1474-1481
Author(s):  
Snorre Aunet ◽  
Hans Kristian Otnes Berge
Keyword(s):  
Power Consumption ◽  
Supply Voltage ◽  
Reducing Power ◽  
Process Variations ◽  
Full Adder ◽  
Cmos Technology ◽  
Subthreshold Cmos ◽  
Order Of Magnitude ◽  
Supply Voltages ◽  
Circuit Technique

In this article we compare a number of full-adder (1- bit addition) cells regarding minimum supply voltage and yield, when taking statistical simulations into account. According to the ITRS Roadmap two of the most important challenges for future nanoelectronics design are reducing power consumption and increasing manufacturability (ITRS, 2005). We use subthreshold CMOS, which is regarded by many as the most promising ultra low power circuit technique. It is also shown that a minimum redundancyfactor as low as 2 is sufficient to make circuits maintain full functionality under the presence of defects. This is, to our knowledge, the lowest redundancy reported for comparable circuits, and builds on a method suggested a few years ago (Aunet & Hartmann, 2003). A standard Full-Adder (FA) and an FA based on perceptrons exploiting the “mirrored gate”, implemented in a standard 90 nm CMOS technology, are shown not to withstand statistical mismatch and process variations for supply voltages below 150 mV. Exploiting a redundancy scheme tolerating “open” faults, with gate-level redundancy and shorted outputs, shows that the same two FAs might produce adequate Sum and Carry outputs at the presence of a defect PMOS for supply voltages above 150 mV, for a redundancy factor of 2 (Aunet & Otnes Berge, 2007). Two additional perceptrons do not tolerate the process variations, according to simulations. Simulations suggest that the standard FA has the lowest power consumption. Power consumption varies more than an order of magnitude for all subthreshold FAs, due to the statistical variations

Electrical Failure Analysis and Characterization of Leakage Paths Leading to Single Cell Failures in 128Mbit SDRAMs

2003 ◽  
Author(s):  
M. Versen ◽  
A. Schramm
Keyword(s):  
Failure Analysis ◽  
Single Cell ◽  
Case Studies ◽  
Leakage Current ◽  
Random Access ◽  
Electrical Failure ◽  
Leakage Path ◽  
Short Summary ◽  
Order Of Magnitude

Abstract A common failure signature in dynamic random access memories (DRAMs) is the single cell failure. The charge is lost and thereby the information stored in trench capacitors can be destroyed by high resistive leakage paths. The nature of the leakage path determines the properties of the failure such as temperature-, voltage- and timing-dependencies and its stability. In this study, high resistive leakage paths were investigated and delimited from classical shorts by estimating the order of magnitude of the leakage current and by comparison to a simple resistive leakage path. Such an investigation is the basis for a defect-based test approach that leads to multiparameter tests [1]. An introduction to the problem is given in the first section, while the second section deals with the characterization of the defects in two case studies. A short summary is given in the end.

scholarly journals Thermo-Optic Phase Tuners Analysis and Design for Process Modules on a Silicon Nitride Platform

Photonics ◽  
2021 ◽  
Vol 8 (11) ◽  
pp. 496
Author(s):  
Rubén Alemany ◽  
Pascual Muñoz ◽  
Daniel Pastor ◽  
Carlos Domínguez
Keyword(s):  
Silicon Nitride ◽  
Power Consumption ◽  
Transfer Model ◽  
Systematic Design ◽  
Design Decisions ◽  
Analysis And Design ◽  
Figures Of Merit ◽  
Order Of Magnitude ◽  
The Cost ◽  
Micro Structures

In this paper, we present a systematic design for manufacturing analysis for thermo-optic phase tuners, framed within the process modules available on a silicon nitride platform. Departing from an established technology platform, the heat distribution in various micro-structures was analyzed, both in steady and transient states, employing a 2D heat transfer model solved numerically. Multi-parametric simulations were performed on designs combining trenches and substrate undercut, by varying their position and dimensions. The simulation results were compared to a reference conventional fully-clad cross-section. Deep air-filled trenches are shown to reduce the power consumption up to 70%, alongside a thermal crosstalk phase shift reduction of more than one order of magnitude (0.045 π rad/mm), at the expense of a slightly lower bandwidth (11.8 kHz). The design with trenches and substrate undercut lowers the power consumption up to 97%, decreases two orders of magnitude the crosstalk (0.006 π rad/mm), at the cost of less than one order of magnitude in bandwidth (0.9 kHz). In the works, we selected three different heater materials (Cr/Au, Al, poly-silicon) offered by the fab and four different heater widths (2.5 to 7 μm). Their combinations are related to performance, reliability and durability of the devices, strongly linked to temperature, current density, and Omegaic resistance. The different figures of merit defined, and the methodology followed, can be mimicked by future designers to take design decisions at bird’s eye.

scholarly journals Indoor Environmental Quality and Consumption Patterns before and during the COVID-19 Lockdown in Twelve Social Dwellings in Madrid, Spain

2021 ◽  
Vol 13 (14) ◽  
pp. 7700
Author(s):  
Fernando de Frutos ◽  
Teresa Cuerdo-Vilches ◽  
Carmen Alonso ◽  
Fernando Martín-Consuegra ◽  
Borja Frutos ◽  
...  
Keyword(s):  
Air Quality ◽  
Power Consumption ◽  
Case Studies ◽  
Environmental Quality ◽  
Indoor Air ◽  
Household Composition ◽  
Consumption Patterns ◽  
Daily Activities ◽  
Indoor Environmental Quality ◽  
Starting Conditions

This article analyses the situation that prevailed in 12 dwellings located on the outskirts of Madrid during Spain’s state of emergency. How did 24/7 occupation affect the quality of indoor air and power consumption patterns? The mixed method used (surveys and instrumental monitoring) pragmatically detected the variation in consumption, comfort and indoor air quality patterns before and during the COVID-19 pandemic. The characteristics initially in place and household predisposition had a conclusive effect on such variations. The starting conditions, including household composition, habits and the way daily activities were performed, differed widely, logically affecting power consumption: 8/12 case studies increase occupancy density by more than 25 percent; 11/12 improve thermal comfort; 10/12 improve air quality but not necessarily translate in a sufficient ventilation practices; air quality was lower in the bedrooms on the whole; only 4/12 case studies use the potential of passive measures; only one household adopted energy savings strategies; 10/12 case studies increase electric power consumption but none of the dwellings was fitted with a renewable power generation system. The conclusion drawn is that, despite starting conditions differing widely, household composition, habits (including performance of daily activities performance) and power consumption also played an active role in the end result. This approach allowed to integrate qualitative and quantitative findings on indoor environmental quality (IEQ), energy use and households’ behavior. The objective data on the energy situation of the case studies not only is useful for the study, but also for potential enrollment in energy rehabilitation programs, such as the European Regional Development Fund (ERDF).

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