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1

An analysis of thermo-magnetic convection of paramagnetic fluid in rectangular enclosure

Kraszewska A., Pyrda Ł.

Acta Innovations

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2016

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no. 18

5--13

EN

The thermo-magnetic convection of paramagnetic fluid in a strong magnetic field is studied. The fluid is aqueous solution of glycerol with gadolinium nitrate hexahydrate. Experimental enclosure – rectangular vessel with aspect ratio equal to 2 – was heated from the bottom, and cooled from the top. Temperature difference between top and bottom walls was kept constant ΔT=5K. The magnetic induction was increased stepwise from 1 to 10 [T]. On the basis of temperature measurements, analysis of heat transfer and fluid flow were performed, showing that magnetic field strongly enhance heat transfer (over 300%) and that aspect ratio of the enclosure has a great influence on heat exchange in the system.

2

Potential of low concentration nanofluids in heat transfer

Roszko A., Fornalik-Wajs E.

Acta Innovations

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2015

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no. 16

48--55

EN

The main purpose of conducted studies was recognition of low concentration nanofluid under the influence of magnetic field potential applications. The investigations are having fundamental character but Authors keep in mind better energy utilization through the heat transfer enhancement. The examined fluid was composed of water and Cu/CuO nanoparticles. Three temperature differences were imposed on the system. The results did not give unequivocal answer on possible utilization of studied phenomena, but there is open scene for the studies of particle-fluid interaction and flow structure. The main conclusion is that the magnetic properties of base fluid and particles are crucial for such analysis.

3

The Structural Relaxation and its Influence on High Field Magnetization Processes

Pietrusiewicz P., Nabiałek M., Szota M., Dośpiał M., Błoch K., Bukowska A., Gruszka K.

Archives of Metallurgy and Materials

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2014

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Vol. 59, iss. 2

659--662

EN

In this paper the results of the structural and magnetic investigation of Fe61Co10Y8Zr1B20 alloy after solidification and isothermal annealing was presented. The isothermical annealing was carried out at 700 K for 1 h and 770 K for 3.5 h. For the structural investigation was performed by X-ray diffractometer equipped with a copper lamp. The results of (XRD) measurements showed the material in the state after the solidification and heat treatment is amorphous. Static hysteresis loops and initial magnetization curve was measured using vibrating magnetometer (VSM). The quality and quantity of structural defects in the sample after heat treatment was determined by indirect method using analyze the initial magnetization curve in accordance with the theory of Kronmüllera. These studies have shown that the annealing process has big influence to change significantly quantity of defects in amorphous structure as a result, there are changes of magnetic parameters such as saturation magnetization and field μ0Ms coercivity Hc.

PL

W pracy przedstawiono wyniki badań strukturalnych i magnetycznych stopu Fe61Co10Y8Zr1B20 w stanie po zestaleniu oraz po izotermicznym wygrzewaniu w temperaturze 700 K przez 1h i 770 K przez 3,5 h. Badania struktury wykonano przy użyciu dyfraktometru rentgenowskiego wyposażonego w lampę miedzianą. Wynik pomiarów (XRD) wykazał, że material w stanie po zestaleniu i obróbce termicznej jest amorficzny. Statyczne pętle histerezy i krzywą pierwotnego namagnesowania zmierzono za pomocą magnetometru wibracyjnego (VSM). Analizując krzywą pierwotnego namagnesowania i wykorzystując pośrednią metodę wyznaczania defektów strukturalnych zgodnie z teorią H. Kronmüllera wyznaczono jakość i ilość tych defektów w próbce w stanie po zestaleniu i po izotermicznym wygrzewaniu. Badania te wykazały że proces wygrzewania istotnie wypływa na zmiany zdefektowania struktury amorficznej w wyniku czego zachodzą zmiany parametrów magnetycznych takich jak magnetyzacja nasycenia μ0Ms i pole koercji Hc.

4

Jądro atomu w silnym polu magnetycznym - przykład 229Th89+

Żylicz J.

Postępy Fizyki

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2006

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T. 57, z. 5

194-198

EN

Predictions of hyperfine structure in hydrogen-like 229Th89+* ions are presented for both the 5/2+ ground state of the nucleus and the 3.5 eV 3/2+ isomeric state. The effect of nuclear spin mixing and mixing oscillations is analyzed. Perspectives of experimental verification of these predictions are briefly discussed.