Fast Bit Compression and Expansion with Parallel Extract and Parallel Deposit Instructions

2006 ◽  
Author(s):  
Yedidya Hilewitz ◽  
Ruby B. Lee
Keyword(s):  
Compression And Expansion

The Effect of Nonlinear Amplitude Growth on the Speech Perception Benefits Provided by a Single-Sided Vocoder

2019 ◽  
Vol 62 (3) ◽  
pp. 745-757 ◽  
Author(s):  
Jessica M. Wess ◽  
Joshua G. W. Bernstein
Keyword(s):  
Transfer Functions ◽  
Spatial Configuration ◽  
Free Field ◽  
Spatial Separation ◽  
Compression And Expansion ◽  
Interaural Difference ◽  
Interaural Differences ◽  
Single Sided Deafness ◽  
Perceptual Separation ◽  
Loudness Growth

PurposeFor listeners with single-sided deafness, a cochlear implant (CI) can improve speech understanding by giving the listener access to the ear with the better target-to-masker ratio (TMR; head shadow) or by providing interaural difference cues to facilitate the perceptual separation of concurrent talkers (squelch). CI simulations presented to listeners with normal hearing examined how these benefits could be affected by interaural differences in loudness growth in a speech-on-speech masking task.MethodExperiment 1 examined a target–masker spatial configuration where the vocoded ear had a poorer TMR than the nonvocoded ear. Experiment 2 examined the reverse configuration. Generic head-related transfer functions simulated free-field listening. Compression or expansion was applied independently to each vocoder channel (power-law exponents: 0.25, 0.5, 1, 1.5, or 2).ResultsCompression reduced the benefit provided by the vocoder ear in both experiments. There was some evidence that expansion increased squelch in Experiment 1 but reduced the benefit in Experiment 2 where the vocoder ear provided a combination of head-shadow and squelch benefits.ConclusionsThe effects of compression and expansion are interpreted in terms of envelope distortion and changes in the vocoded-ear TMR (for head shadow) or changes in perceived target–masker spatial separation (for squelch). The compression parameter is a candidate for clinical optimization to improve single-sided deafness CI outcomes.

Comparison between Flat and Creviced Pistons in a Controlled Trajectory Rapid Compression and Expansion Machine (CT-RCEM)

2021 ◽  
Author(s):  
Krishna Chandra C. Bavandla ◽  
Abhinav Tripathi ◽  
Dezhi Zhou ◽  
Zongxuan Sun ◽  
Suo Yang
Keyword(s):  
Compression And Expansion ◽  
Rapid Compression

scholarly journals Calculation and interpretation of classical turning surfaces in solids

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Aaron D. Kaplan ◽  
Stewart J. Clark ◽  
Kieron Burke ◽  
John P. Perdew
Keyword(s):  
Density Functional ◽  
Molecular Crystals ◽  
Chemical Properties ◽  
Density Functionals ◽  
Compression And Expansion ◽  
Forbidden Regions ◽  
Internuclear Distances ◽  
Wide Gap ◽  
Equilibrium Geometries ◽  
Classical Picture

AbstractClassical turning surfaces of Kohn–Sham potentials separate classically allowed regions (CARs) from classically forbidden regions (CFRs). They are useful for understanding many chemical properties of molecules but need not exist in solids, where the density never decays to zero. At equilibrium geometries, we find that CFRs are absent in perfect metals, rare in covalent semiconductors at equilibrium, but common in ionic and molecular crystals. In all materials, CFRs appear or grow as the internuclear distances are uniformly expanded. They can also appear at a monovacancy in a metal. Calculations with several approximate density functionals and codes confirm these behaviors. A classical picture of conduction suggests that CARs should be connected in metals, and disconnected in wide-gap insulators, and is confirmed in the limits of extreme compression and expansion. Surprisingly, many semiconductors have no CFR at equilibrium, a key finding for density functional construction. Nonetheless, a strong correlation with insulating behavior can still be inferred. Moreover, equilibrium bond lengths for all cases can be estimated from the bond type and the sum of the classical turning radii of the free atoms or ions.

scholarly journals Air Movement in Snow Due to Windpumping

1989 ◽  
Vol 35 (120) ◽  
pp. 209-213 ◽  
Author(s):  
S.C. Colbeck
Keyword(s):  
Pore Space ◽  
Barometric Pressure ◽  
Surface Flows ◽  
Wind Speeds ◽  
Compression And Expansion ◽  
Strong Winds ◽  
Pressure Changes ◽  
Low Amplitude ◽  
Pressure Perturbations ◽  
Rapid Pressure

Abstract Strong winds can disrupt the thermal regime in seasonal snow because of the variation in surface pressure associated with surface features like dunes and ripples. Topographical features of shorter wavelengths produce stronger surface flows, but the flow decays rapidly with depth. Longer-wavelength features produce weaker surface flows but the flow decays more slowly with depth. The flow may only be strong enough to disrupt the temperature field for features of wavelengths on the scale of meters or tens of meters at wind speeds of 10 m/s or more. Other possible causes of windpumping have been examined but they do not appear to be as significant. Rapid pressure perturbations due to turbulence produce very little displacement of the air because of the high frequency and low amplitude. Barometric pressure changes cause compression and expansion of the air in the pore space, but the rate is too low to have much effect.

Defining the Thermodynamic Efficiency in a Wave Rotor

2016 ◽  
Vol 138 (11) ◽  
Author(s):  
Shining Chan ◽  
Huoxing Liu ◽  
Fei Xing
Keyword(s):  
Gas Turbine ◽  
Control Volume ◽  
Thermodynamic Efficiency ◽  
Wave Rotor ◽  
Wave Rotors ◽  
Compression And Expansion ◽  
Efficiency Estimation ◽  
Parametric Analyses ◽  
Control Volumes ◽  
Thermodynamic Processes

A wave rotor enhances the performance of a gas turbine with its internal compression and expansion, yet the thermodynamic efficiency estimation has been troubling because the efficiency definition is unclear. This paper put forward three new thermodynamic efficiency definitions to overcome the trouble: the adiabatic efficiency, the weighted-pressure mixed efficiency, and the pressure pre-equilibrated efficiency. They were all derived from multistream control volumes. As a consequence, they could correct the efficiency values and make the values for compression and expansion independent. Moreover, the latter two incorporated new models of pre-equilibration inside a control volume, and modified the hypothetical “ideal” thermodynamic processes. Parametric analyses based on practical wave rotor data demonstrated that the trends of those efficiency values reflected the energy losses in wave rotors. Essentially, different thermodynamic efficiency definitions indicated different ideal thermal cycle that an optimal wave rotor can provide for a gas turbine, and they were recommended to application based on that essence.

scholarly journals Inner Damping of Water in Conduit of Hydraulic Power Plant

2021 ◽  
Vol 13 (13) ◽  
pp. 7125
Author(s):  
Daniel Himr ◽  
Vladimír Habán ◽  
David Štefan
Keyword(s):  
Power Plant ◽  
Operating Conditions ◽  
Mathematical Apparatus ◽  
Pressure Pulsations ◽  
Hydraulic Power ◽  
Economic Operation ◽  
Compression And Expansion ◽  
Rotor Stator Interaction ◽  
Start Ups

The operation of any hydraulic power plant is accompanied by pressure pulsations that are caused by vortex rope under the runner, rotor–stator interaction and various transitions during changes in operating conditions or start-ups and shut-downs. Water in the conduit undergoes volumetric changes due to these pulsations. Compression and expansion of the water are among the mechanisms by which energy is dissipated in the system, and this corresponds to the second viscosity of water. The better our knowledge of energy dissipation, the greater the possibility of a safer and more economic operation of the hydraulic power plant. This paper focuses on the determination of the second viscosity of water in a conduit. The mathematical apparatus, which is described in the article, is applied to data obtained during commissioning tests in a water storage power plant. The second viscosity is determined using measurements of pressure pulsations in the conduit induced with a ball valve. The result shows a dependency of second viscosity on the frequency of pulsations.

Oscillations in Closed Surge Tanks

1943 ◽  
Vol 10 (4) ◽  
pp. A183-A186
Author(s):  
A. M. Binnie
Keyword(s):  
Small Scale ◽  
Maximum Pressure ◽  
Surge Tank ◽  
Compression And Expansion ◽  
Made In

Abstract The existing methods of predicting the oscillations in a closed surge tank are very lengthy unless drastic simplifications are made. In this paper a new and quick procedure is explained for calculating the maximum pressure and expansion of the air, which result from a sudden shutdown of the plant. Friction is taken into account, both in the pipe and also in any arrangement placed between the pipe and the tank to damp the oscillations, but the compression and expansion of the air must be assumed isothermal. Small-scale experiments confirmed the expectation that the observed maximum pressures would be greater than the theoretical. The shutdown of a big plant is, however, not instantaneous, and the theory may be expected to yield results sufficiently accurate for the purpose in view.

Arterial blood gas measurements during deep open-water breath-hold dives

2021 ◽  
Author(s):  
Tom Scott ◽  
Hanna van Waart ◽  
Xavier CE Vrijdag ◽  
David Mullins ◽  
Peter Mesley ◽  
...  
Keyword(s):  
Open Water ◽  
Absolute Pressure ◽  
Breath Hold ◽  
Blood Gas ◽  
Mixed Gas ◽  
Constant Weight ◽  
Arterial Blood Gas ◽  
Arterial Blood ◽  
Compression And Expansion ◽  
Gas Measurements

Arterial blood gas (ABG) measurements at both maximum depth and at re-surfacing prior to breathing have not previously been measured during freedives conducted to extreme depth in cold open-water conditions. An elite freediver was instrumented with a left radial arterial cannula connected to two sampling syringes through a low-volume splitting device. He performed two open-water dives to 60 metres depth (197', 7 atmospheres absolute pressure) in the constant weight with fins competition format. ABG samples were drawn at 60 metres (by a mixed-gas scuba diver), and again on re-surfacing before breathing. An immersed surface static apnea, of identical length to the dives and with ABG sampling at identical times, was also performed. Both dives lasted approximately two minutes. PaO2 increased during descent from an indicative baseline of 15.8 kPa (after hyperventilation and glossopharyngeal insufflation) to 42.8 and 33.3 kPa (dives one and two), and decreased precipitously (to 8.2 and 8.6 kPa) during ascent. PaCO2 also increased from a low indicative baseline of 2.8 kPa to 6.3 and 5.1 kPa on dives one and two; an increase not explained by metabolic production of CO2 alone since PaCO2 actually decreased during ascent (to 5.2 and 4.5 kPa). Surface static apnea caused a steady decrease in PaO2 and increase in PaCO2 without the inflections provoked by depth changes. Lung compression and expansion provoke significant changes in both PaO2 and PaCO2 during rapid descent and ascent on a deep freedive. These changes generally support predictive hypotheses and previous findings in less extreme settings.

Thermodynamic Performance Optimization of Reciprocating Internal Combustion (IC) Engines

2008 ◽  
Author(s):  
George A. Adebiyi ◽  
Kalyan K. Srinivasan ◽  
Charles M. Gibson
Keyword(s):  
Performance Optimization ◽  
Combustion Process ◽  
Design Parameters ◽  
Second Law ◽  
Ic Engine ◽  
Thermodynamic Performance ◽  
Second Law Analysis ◽  
Compression And Expansion ◽  
Dual Cycle ◽  
Ic Engines

Reciprocating IC engines are traditionally modeled as operating on air standard cycles that approximate indicator diagrams obtained in experiments on real engines. These indicator diagrams can best be approximated by the dual cycle for both gasoline and diesel engines. Analysis of air standard cycles unfortunately fails to capture second law effects such as exergy destruction due to the irreversibility of combustion. Indeed, a complete thermodynamic study of any process requires application of both the first and second laws of thermodynamics. This article gives a combined first and second law analysis of reciprocating IC engines in general with optimization of performance as primary goal. A practical dual-like cycle is assumed for the operation of a typical reciprocating IC engine and process efficiencies are assigned to allow for irreversibilities in the compression and expansion processes. The combustion process is modeled instead of being replaced simply by a heat input process to air as is common in air standard cycle analysis. The study shows that performance of the engine can indeed be optimized on the basis of geometrical design parameters such as the compression ratio as well as the air-fuel ratio used for the combustion.

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