Wyniki wyszukiwania - BazTech

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Wykorzystanie wykresów entalpia - entropia do obliczeń inżynierskich w gazownictwie

Barczyński Andrzej, Barczyński Paweł

Gaz, Woda i Technika Sanitarna

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2019

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Nr 9

282--285

PL

W artykule omówiono możliwości zastosowania wykresów entalpia - entropia do obliczeń inżynierskich w branży gazowniczej. Jest on przeznaczony dla kadry technicznej zajmującej się projektowaniem, budową oraz eksploatacją obiektów gazowniczych (tłocznie, stacje redukcyjne, instalacje wykorzystujące energię potencjalną zawartą w sprężonym gazie). Dzięki tym wykresom można w sposób prosty wyznaczyć np. ilość ciepła jaką należy doprowadzić do strumienia gazu, aby go podgrzać (ciepło technologiczne) lub ochłodzić od temperatury t1, do t2, po jego sprężeniu, określić moc sprężarki zainstalowanej na tłoczni gazu, moc turbiny uzyskanej w wyniku rozprężenia gazu [8,9], parametry pracy reduktora takie jak: temperatura gazu za reduktorem, najniższa temperatura jaka może się pojawić w reduktorze itp.

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Physical Implementation and Testing of Low-Power Adiabatic Flip-Flops with Energy-Recycling Pads

Jiang J., Hu J.

Przegląd Elektrotechniczny

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2012

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R. 88, nr 9b

192-195

EN

This paper presents adiabatic flip-flops based on CPAL (complementary pass-transistor adiabatic logic) circuits with energy-recycling output pad cells. The energy-recycling output pad cells for driving adiabatic chips include mainly bonding pads, ESD (electrostatic discharge) protection circuits, and two stage energy-recycling buffers. The adiabatic flip-flops and sequential circuits with energy-recycling output pad cells have been fabricated with Chartered 0.35um process. The adiabatic flip-flops have large energy savings over a wide range of frequencies.

PL

W artykule zaproponowano adiabatyczny przerzutnik bazujący na układach CPAL – complementary pass-transistor adiabatic logic). Zastosowano też blok wyjściowy z odzyskiwaniem energii.

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The quantum diffusion of carbon in alfa-iron in low temperature

Dąbrowski L., Andreev A., Georgiev M.

Nukleonika

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2006

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Vol. 51, nr 2

93-99

EN

Recent experimental data on the diffusion coefficient of carbon in á-iron below liquid nitrogen temperature (LNT) question the classical approach to the observed temperature dependence. As the temperature is lowered below LNT, the diffusion constant tends to a nearly temperature-independent value rather than continuing its activated trend. The low temperature branch is apparently characteristic of a quantum mechanical process dominated by tunneling in ground state. Concomitantly we apply an occurrence-probability approach to describing the overall temperature dependence as a single continuous rate. Within the adiabatic approximation the electronic eigenvalue depending parametrically on the nuclear coordinates is taken to be the potential energy to control the motion of the nuclei. The resulting rate involves all horizontal-tunneling energy-conserving elastic transitions at the quantized energy levels of the migrating atom. A small though not negligible slope in the temperature dependence as the temperature is raised below 100 K is dealt with by complementing for the rate of a parallel one-phonon inelastic-tunneling process in excess to the basic elastic-tunneling rate. Our combined approach agrees well with the experimental data. In particular, the frequency of the coupled vibration is obtained virtually identical to the carbon vibrational frequency from inelastic neutron scattering data. The migrational barrier is also found to be within the limits expected for alfa-iron.

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Non-linear spectral analysis of Rayleigh-Benard convection in a high-porosity medium

Thangaraj R. P.

International Journal of Applied Mechanics and Engineering

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2002

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Vol. 7, no 4

1305-1328

EN

A local non-linear stability analysis using the spectral method is made of the Rayleigh-Benard situation in a high-porosity porous medium. The series expansion solution so obtained is valid for a large range of imposed temperature differences and yields a quantitative estimate of the heat transport by convection. Streamline patterns and mean temperature distributions have been obtained. The temperature distributions show that at the middle of the fluid-filled porous layer a layer of isothermal mean temperature develops, thus limiting the major heat transport to thermal boundary layers. The damping nature of porous media on heat transport is also clearly brought out.

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The effect of non-uniform basic temperature gradient on the convective instability of a fluid layer sandwiched between two porous layers with general velocity and thermal conditions

Thangaraj R. P.

International Journal of Applied Mechanics and Engineering

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2001

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Vol. 6, no 1

35-52

EN

The stability of a horizontal fluid layer bounded on either side by porous layers with different permeabilities is examined for different non-uniform basic temperature gradients using general velocity and thermal conditions at the boundaries. In the case of sudden heating and cooling, analytical solutions are obtained using single-term Galerkin expansion. Numerical solutions are obtained for all possible combinations of basic temperature gradients and boundary conditions in respect of velocity and temperature. General conclusion about the thermal depth and the destabilizing effects of the basic temperature gradients are presented. The classical results of free-free, rigid-free and rigid-rigid boundaries with isothermal or adiabatic boundaries are recovered as limiting cases of the present study.