Physico-Mathematical Model of the Theoretical Gamma-Type Stirling Motor-Driven Compressor

2014 ◽  
Vol 659 ◽  
pp. 383-388
Author(s):  
Vlad Mario Homutescu ◽  
Dan Teodor Balanescu
Keyword(s):  
Mathematical Model ◽  
Thermodynamic Cycle ◽  
Absolute Maximum ◽  
Isothermal Compression ◽  
Expansion Process ◽  
Isothermal Model ◽  
Heating And Cooling ◽  
The Absolute ◽  
The Ideal

Paper is analyzing a physico-mathematical isothermal model of the theoretical engine-driven gamma-type Stirling compressor. The absolute maximum performances of an theoretical engine-driven gamma-type Stirling compressor (that function after a thermodynamic cycle comprising two isochoric processes of heating and cooling the agent, one isothermal compression and one partially-cooled expansion process) are obtained. Using these absolute maximum performances as reference, it is possible to assess the degree in which several real physical constructions of this machine can approach to the ideal functioning.

Gamma-Type Stirling Motor-Driven Compressor

2014 ◽  
Vol 659 ◽  
pp. 377-382 ◽  
Author(s):  
Vlad Mario Homutescu ◽  
Dan Teodor Balanescu
Keyword(s):  
Mathematical Model ◽  
Thermodynamic Cycle

Paper is analyzing an engine-driven gamma-type Stirling compressor by means of an isothermal physico-mathematical model. The maximum performances of an engine-driven gamma-type Stirling compressor (working after a quasi-Stirling thermodynamic cycle) are obtained. By using these maximum performances as reference, a comparison between different physical embodiments of engine-driven gamma-type Stirling compressors can be achieved.

Development of a Mathematical Model for a Workpiece Heating and Cooling in a Protective Medium while Treatment under Pressure

2021 ◽  
Vol 410 ◽  
pp. 115-122
Author(s):  
Victoria V. Devyatiarova ◽  
Eugenia E. Balakhnina ◽  
Lilya M. Valeeva
Keyword(s):  
Mathematical Model ◽  
Cross Section ◽  
Arbitrary Shape ◽  
Thermal Conductivity Coefficient ◽  
Regression Equations ◽  
Heating And Cooling ◽  
Temperature Problem ◽  
Protective Medium ◽  
Computer Calculations ◽  
The Mathematical Model

The paper reviews and develops the mathematical model of plastic flow during the hot-forming processes. A flat non-stationary temperature problem for a cross-section of a long solid (rolled product) of arbitrary shape with different heat transfer conditions along the perimeter of the cross-section was considered. Equations for calculation of the thermal conductivity coefficient and heat capacity of tungsten billets were obtained in the temperature range of 700 - 1500°C, based on the literature data. Analytical dependences in form of regression equations were obtained, allowing for computer calculations of physical specifications of 11x11 mm VA grade tungsten billets in form of temperature functions with accuracy sufficient for practical calculations.

scholarly journals Population Characteristics Erodium tataricum Willd.

2020 ◽  
Vol 6 (9) ◽  
pp. 45-52
Author(s):  
E Krylova
Keyword(s):  
Population Characteristics ◽  
Absolute Maximum ◽  
Aerial Parts ◽  
Ontogenetic Structure ◽  
Tap Root ◽  
The Absolute ◽  
Herbaceous Perennial

Erodium tataricum is a herbaceous perennial multi-headed tap-root (caudex) plant. Hemicryptophyte. Endemic. The ontogenetic structure was studied in the shrub-herb-grass petrophytic steppe. Individuals of the species have four periods and ten ontogenetic states. It was revealed that the population is normal with an incomplete spectrum. In accordance with the classification of A. A. Uranova and O. V. Smirnova the population is definitive. According to the criterion of the absolute maximum, the population is young. The ontogenetic spectrum of the population is left-sided. A specific ontogenetic spectrum corresponds to a characteristic ontogenetic spectrum, i.e. biology of the species. According to the ontogenetic spectrum, the development of the population is characterized as sustainable. The peculiarity of Erodium tataricum is that on all aerial parts of the plant there is abundant pubescence, but in the old generative ontogenetic state, pubescence on the leaves decreases. Reproduction of the species is carried out by seed. In the subsenile ontogenetic state, senile particulation is possible.

The ideal pseudo-rigid continuum

2006 ◽  
Vol 462 (2074) ◽  
pp. 3185-3195 ◽  
Author(s):  
James Casey
Keyword(s):  
Mathematical Model ◽  
Mathematical Models ◽  
Royal Society ◽  
Recent Article ◽  
Finite Size ◽  
Rigid Bodies ◽  
Global Constraint ◽  
Restricted Class ◽  
The Ideal

In the literature on pseudo-rigid bodies and their applications, it is generally assumed that these bodies can undergo only a restricted class of motions, without questioning how this restriction is to be strictly enforced. In 2004, I proposed in these Proceedings that such a restriction may be regarded as a ‘global constraint’ on a deformable continuum, and influenced by ideas of Antman & Marlow from the early 1990s, I assumed that the constraint is enforced by a field of reactive stresses, and I constructed a mathematical model that idealizes pseudo-rigid bodies as globally constrained continua of finite size. In a recent article in Proceedings of the Royal Society A , the validity of this model was challenged. Essentially, the controversy revolves around the issue of working definitions versus idealized mathematical models of pseudo-rigid bodies.

Dynamics of Submerged Expandable Tubes in Borehole Wells

2005 ◽  
Author(s):  
Ali Karrech ◽  
Abdennour Seibi ◽  
Tasneem Pervez ◽  
Karam Sab
Keyword(s):  
Mathematical Model ◽  
Analytical Solution ◽  
Elastic Limit ◽  
Petroleum Industry ◽  
Differential Pressure ◽  
Pressure Waves ◽  
Expansion Process ◽  
Fluid System ◽  
New Development ◽  
Potential Failure

Solid Expandable Tubular Technology (SETT) is a new development in the petroleum industry. It consists in accomplishing hydraulic expansion of a submerged tube by propelling a mandrel through it using a differential pressure. The progress of the mandrel deforms the tube beyond its elastic limit. Towards the end of the expansion process, the mandrel pops out of the tube resulting in displacement, stress and pressure waves. A mathematical model is developed to describe the dynamics of the tube-fluid system due to the pop-out phenomenon. The model takes into consideration the effects of the coupling between fluids and structure as well as the inherent system damping on the response. Through a specific field case, the model provides an analytical solution describing the wave propagating in the tube-fluid system and identifies the potential failure locations.

Estimation Accuracy of Absolute Maximum Elasto-Plastic Displacements of MDOF Oscillators Based on a Modal Combination Rule With Post-Yielding Modal Properties and Linear Response Spectrum Values

2018 ◽  
Author(s):  
Tomoyo Taniguchi ◽  
Yoshihiko Toda ◽  
Yusuke Ono ◽  
Kyosuke Mukaibo
Keyword(s):  
Response Spectrum ◽  
Time History ◽  
Degree Of Freedom ◽  
Estimation Accuracy ◽  
Absolute Maximum ◽  
Earthquake Excitation ◽  
Linearized System ◽  
The Absolute ◽  
Plastic Displacement ◽  
Mode 3

Taniguchi, et al. [1] developed an analytical method for evaluating the absolute maximum elasto-plastic displacements of multi-degree-of-freedom (MDOF) oscillators under the action of base excitation based on a modal combination. Its essence is that 1) modal frequencies, shapes and damping during yielding of any member of the MDOF oscillators are readily specified by the modal analysis with the secondary stiffness of the members being yielded, 2) assuming that a bilinear hysteresis may describe the force-displacement relationship of each mode, an equivalently linearized system consisting of a single-degree-of-freedom (SDOF) oscillator is introduced to approximate the absolute maximum elasto-plastic displacement of each mode, 3) the absolute maximum elasto-plastic displacement of the MDOF oscillator is evaluated by the Square Root of Sum of Squares rule (SRSS-rule) by combining the maximum elasto-plastic displacement of each mode approximated by the proposed equivalently linearized system. This study first provides small modification in the equivalently linearized system. Then, employing a couple of MDOF oscillators whose spring at arbitrary storey may yield and an accelerogram, the maximum elasto-plastic displacement of the MDOF oscillator is calculated by the proposed method and is compared with that computed by the time history analysis. Their comparison suggests that the proposed method can reasonably evaluate the absolute maximum elasto-plastic displacement of the MDOF oscillator subjected to earthquake excitation as the conventional SRSS-rule does that for the linear MDOF oscillators.

scholarly journals Discovering sounds in Patagonia, characterizing sei whale (<i>Balaenoptera borealis</i>) downsweeps in the south-eastern Pacific Ocean

2018 ◽  
Author(s):  
Sonia Español-Jiménez ◽  
Paulina A. Bahamonde ◽  
Gustavo Chiang ◽  
Verena Häussermann
Keyword(s):  
Pacific Ocean ◽  
Peak Frequency ◽  
Eastern Pacific ◽  
Absolute Maximum ◽  
Maximum Frequency ◽  
Eastern Pacific Ocean ◽  
The South ◽  
South Eastern ◽  
Average Maximum ◽  
The Absolute

Abstract. Sei whales (Balaenoptera borealis) is the least known whale species. Information on sei whale´s vocalizations in the south-eastern Pacific Ocean and its regional variability are even more scarce than that from other ocean areas. This research presents the first characterization of sei whale sounds recorded in Chile during austral autumn of 2016 and 2017. A total of 41 calls have been attributed to sei whale’s downsweeps. In 2016, calls ranged from an average maximum frequency of 105.3 Hz down to an average minimum 35.6 Hz over 1.6 s with a peak frequency of 65.4 Hz. During 2017, calls ranged from an average maximum frequency of 93.3 Hz down to 42.2 Hz (over 1.6 s) with a peak frequency of 68.3 Hz. The absolute minimum frequency recorded was 30 Hz and the absolute maximum frequency was 129.4 Hz. Calls generally occurred in pairs, but triplets or singles were also registered. These low frequency sounds share characteristics with recordings of sei whales near the Hawaii Islands, but with differences in the maximum frequencies and duration. These calls distinctly differ from sounds previously described for sei whales in the Southern Ocean and are the first documented sei whale calls in the South-eastern Pacific.

The Ideal Local Party Secretary and the “Model” Man

1964 ◽  
Vol 17 ◽  
pp. 229-240 ◽  
Author(s):  
A. S. Chen
Keyword(s):  
Communist Party ◽  
Direct Observation ◽  
Absolute Power ◽  
Party Secretary ◽  
The People ◽  
The Absolute ◽  
Local Party ◽  
The Ideal

In what light does the Communist Party wish to project itself to the people? Is the local party secretary presented as the remote symbol of authoritarian efficiency, a reflection of the absolute power above? Or is he supposed to be a model of the nutrient “helper,” responsive to the people's needs and governed by humanitarian considerations? The actual quality of these relationships is of course inaccessible for direct observation, but we can examine some of the Communist presentations of the image and expectations in officially approved literary publications.

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