Paradoxical magnetic cooling in a structural transition model

Paradoxical magnetic cooling in a structural transition model

In contrast to the experimentally widely used isentropic demagnetization process for cooling to ultra-low temperatures we examine a particular classical model system that does not cool, but rather heats up with isentropic demagnetization. This system consists of several magnetite particles in a colloidal suspension, and shows the uncommon behavior of disordering structurally while ordering magn...

Presenting a paradoxical cognitive strategy model on human resource agility

Background: Educational organizations are one of the main pillars in human society and the development and survival of societies depends on the good performance of these organizations. Universities are among the social systems. In which real power arises from recognizing patterns of change, measuring and seizing opportunities. In this type of environment, human resources need many competencies ...

The Effect of Transition Metals Incorporation on the Structural and Magnetic Properties of Magnesium Oxide Nanoparticles

Pure and doped magnesium oxide nanoparticles were successfully synthesized employing a sol-gel process. The synthesized nanoparticles were characterized by thermal differential analysis, X-ray powder diffraction, transmission electron microscopy, scanning electron microscope, energy-dispersive X-ray spectroscopy, and vibrating sample magnetometer. X-ray diffraction patterns confirmed the crysta...

Structural properties and magnetic phase transition in HoNi2Mn (57Fe)

Synthesis and characterization of magnetic γ- Fe2O3 nanoparticles: Thermal cooling enhancement in a sinusoidal headbox

Nano-size maghemite (γ-Fe2O3) particles were prepared in one step using ultrasound radiation. The obtained nanoparticles were characterized by SEM, TEM , XRD, FTIR, and VSM. The results revealed that the synthesized nanoparticles were spherical, mono-dispersed and uniform. Furthermore, the crystalline structure of nanoparticles endorsed by X-ray diffraction study. The FTIR spectra have provided...