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1
Content available Kamienie milowe & wyzwania ekonofizyki a także socjofizyki cz. 1
Kutner Ryszard
Postępy Fizyki
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2022
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T. 73, z. 1
11--20
PL
Omówiono kamienie milowe ekonofizyki a także socjofizyki wybrane w kontekście wyzwań, jakie stawia współczesna społeczno-ekonomiczna rzeczywistość. Wskazano na ich rolę w budowaniu obszarów badawczych ekonofizyki i socjofizyki [1, 2, 3, 4 ].
EN
We discuss the milestones of econophysics and sociophysics. We chose them in the context of the challenges posed by contemporary socio-economic reality. We indicate their role in building research areas in econophysics and sociophysics [1, 2, 3, 4 ].
2
Content available Scaling laws for the FE solutions of induction machines
Nell Martin, Lenz Jonas, Hameyer Kay
Archives of Electrical Engineering
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2019
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Vol. 68, nr 3
677--695
EN
In this paper a scaling approach for the solution of 2D FE models of electric machines is proposed. This allows a geometrical and stator and rotor resistance scaling as well as a rewinding of a squirrel cage induction machine enabling an efficient numerical optimization. The 2D FEM solutions of a reference machine are calculated by a model based hybrid numeric induction machine simulation approach. In contrast to already known scaling procedures for synchronous machines the FEM solutions of the induction machine are scaled in the stator-current-rotor-frequency-plane and then transformed to the torque-speed-map. This gives the possibility to use a new time scaling factor that is necessary to keep a constant field distribution. The scaling procedure is validated by the finite element method and used in a numerical optimization process for the sizing of an electric vehicle traction drive considering the gear ratio. The results show that the scaling procedure is very accurate, computational very efficient and suitable for the use in machine design optimization.
3
Content available remote Design of premium efficiency (IE3) induction motors using evolutionary optimization and scaling laws
Žarko D., Frljić S., Stipetić S.
Przegląd Elektrotechniczny
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2016
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R. 92, nr 12
181--184
EN
The paper presents a method for optimal design of premium efficiency (IE3) squirrel-cage induction motor by utilizing radial scaling, axial scaling and rewinding of an existing 4 kW 4-pole high efficiency (IE2) motor. The scaling factors are defined for all parameters of the equivalent circuit and consider the influence of saturation on main and leakage inductances in all operating points. The optimal scaling factors are determined using Differential evolution optimization algorithm with minimum volume of iron stack defined as a cost function.
PL
W artykule zaprezentowano metodę optymalnego projektowania silnika indukcyjnego klatkowego w standardzie IE3 poprzez wykorzystanie skalowania promieniowego, osiowego oraz przezwojenia istniejącego silnika czterobiegunowego o mocy 4 kW w standardzie IE2. Współczynniki skalowania zdefiniowane zostały dla wszystkich parametrów obwodu zastępczego. Został rozważony wpływ nasycenia na indukcyjności: główną I rozproszenia we wszystkich punktach działania. Optymalne współczynniki skalowania są określone za pomocą algorytmu optymalizacyjnego ewolucji różniczkowej z minimalną objętością ferromagnetyka zdefiniowaną jako funkcja kosztu.
4
Content available Diagnostics and scaling of fusion-produced neutrons in PF experiments
Schmidt H.
Nukleonika
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2011
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Vol. 56, No. 2
107-112
EN
Neutrons from a plasma focus (PF) device operated in a deuterium gas, measured as a function of time, location and direction of emission, reveal quite a number of important parameters on fusion reactions occurring in the dense high-current phase of the experiment. In addition the determination of the energy spectra of the emitted neutrons is important for understanding the mechanisms taking place for the neutron production. Results of neutron measurements in large experiments such as the former POSEIDON experiment in Stuttgart and the PF-1000 experiment in Warsaw are presented. The neutron diagnostic methods that had been utilized include nuclear track detectors, plastic scintillators coupled to photomultipliers, activation measurements, time-of-flight methods as well as pinholes for spatial resolution of the neutron source. The well known scaling law according to which the neutron yield scales roughly as the square of the energy input or the fourth power of the current is discussed. Reasons for strong deviation from this law for high energies - known as the saturation effect - are still a subject of debate.
5
Content available remote Nano-mechanics or how to extend continuum mechanics to nano-scale
Wang J., Karihaloo B.L., Duan H.L.
Bulletin of the Polish Academy of Sciences. Technical Sciences
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2007
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Vol. 55, nr 2
133-140
EN
In a series of recent papers we have shown how the continuum mechanics can be extended to nano-scale by supplementing the equations of elasticity for the bulk material with the generalised Young-Laplace equations of surface elasticity. This review paper begins with the generalised Young-Laplace equations. It then generalises the classical Eshelby formalism to nano-inhomogeneities; the Eshelby tensor now depends on the size of the inhomogeneity and the location of the material point in it. The generalized Eshelby formalism for nano-inhomogeneities is then used to calculate the strain fields in quantum dot (QD) structures. This is followed by generalisation of the micro-mechanical framework for determining the effective elastic proper-ties of heterogeneous solids containing nano-inhomogeneities. It is shown that the elastic constants of nanochannel-array materials with a large surface area can be made to exceed those of the non-porous matrices through pore surface modification or coating. Finally, the scaling laws governing the properties of nano-structured materials are given.
6
Content available Recent progress in 1 MJ Plasma-Focus research
Scholz M., Karpiński L., Paduch M., Tomaszewski K., Miklaszewski R., Szydlowski A.
Nukleonika
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2001
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Vol. 46, nr 1
35-39
EN
The paper reports on actual operational characteristics of the PF-1000 facility and it presents results of the first neutron experiments performed with a new set of large Mather-type electrodes, which were designed for shots up to 1000 kJ. Dynamics of a current-sheath was studied by means of two high-speed streak cameras and a two-frame camera. The last one was used for the side-on observation of the pinch column. The high-speed streak pictures were taken side-on behind slits oriented in the radial or axial direction. On the basis of the pictures taken behind the radial slit, average values of the radial compression and expansion velocities were estimated. Time-resolved X-ray signals were measured with PIN diodes covered by different filters, and they were compared with other traces (voltage waveforms, dI/dt signals, and neutron-induced pulses) in order to determine their correlation. The total neutron yield (Ytot), i.e. the number of neutrons produced during a single discharge and emitted in various directions, was measured by means of several silver-activation detectors placed at different angles around the PF-1000 experimental chamber.
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