An alternate model for magnetization plateaus in the molecular magnet V_15

Starting from an antiferromagnetic Heisenberg Hamiltonian for the fifteen spin-1/2 ions in V_15, we construct an effective spin Hamiltonian involving eight low-lying states (spin-1/2 and spin-3/2) coupled to a phonon bath. We numerically solve the time-dependent Schrodinger equation of this system, and obtain the magnetization as a function of temperature in a time-dependent magnetic field. The magnetization exhibits unusual patterns of hysteresis and plateaus as the field sweep rate and temperature are varied. The observed plateaus are not due to quantum tunneling but are a result of thermal averaging. Our results are in good agreement with recent experimental observations.Comment: Revtex, 4 pages, 5 eps figure

High-resolution thermal expansion measurements under Helium-gas pressure

We report on the realization of a capacitive dilatometer, designed for high-resolution measurements of length changes of a material for temperatures 1.4 K $\leq T \leq$ 300 K and hydrostatic pressure $P \leq$ 250 MPa. Helium ($^4$He) is used as a pressure-transmitting medium, ensuring hydrostatic-pressure conditions. Special emphasis has been given to guarantee, to a good approximation, constant-pressure conditions during temperature sweeps. The performance of the dilatometer is demonstrated by measurements of the coefficient of thermal expansion at pressures $P \simeq$ 0.1 MPa (ambient pressure) and 104 MPa on a single crystal of azurite, Cu$_3$(CO$_3$)$_2$(OH)$_2$, a quasi-one-dimensional spin S = 1/2 Heisenberg antiferromagnet. The results indicate a strong effect of pressure on the magnetic interactions in this system.Comment: 8 pages, 7 figures, published in Rev. Sci. Instrum with minor change

Effectiveness of Virtualization in the Process of Running a Virtual Instance of a Computer System in a Layer Abstracted from the Actual Hardware

oai:ojs2.ojs.technoaretepublication.org:article/9Abstract - Under this research paper many different kinds of viewpoints concept of Virtualizations, the use ofvisualization for security reasons, and the Importance of IoT in the virtualization process. Moreover, this paper willsignify that Different virtual environments are offered through a virtualized IT firm, which has to be accepted andoperated if technology evolves quickly. This research paper will highlight many different types of strong andsustainable viewpoints about the visualization process and its impacts. It can be a supportive way for the nextresearcher to understand the scope of this research paper in a proper manner. In order to conduct a properunderstanding of the effect of virtualization in running a virtual instance of a computer system from actualhardware will be the main aim of this paper. On the other hand, virtualization may also be described as a techniquethat can theoretically divide a server's physical resources and use it as several, separated computers known asvirtual machines

Languages' impact on emotional classification methods

There is currently a lack of research concerning whether Emotional Classification (EC) research on a language is applicable to other languages. If this is the case then we can greatly reduce the amount of research needed for different languages. Therefore, we propose a framework to answer the following null hypothesis: The change in classification accuracy for Emotional Classification caused by changing a single preprocessor or classifier is independent of the target language within a significance level of p = 0.05. We test this hypothesis using an English and a Danish data set, and the classification algorithms: Support-Vector Machine, Naive Bayes, and Random Forest. From our statistical test, we got a p-value of 0.12852 and could therefore not reject our hypothesis. Thus, our hypothesis could still be true. More research is therefore needed within the field of cross-language EC in order to benefit EC for different languages