Alien Registration- Finnemore, Louise M. (Detroit, Somerset County)

https://digitalmaine.com/alien_docs/9751/thumbnail.jp

Temperature- and magnetic-field-dependent resistivity of MgB2 sintered at high temperature and high pressure condition

We report the temperature- and magnetic-field-dependent resistivity of MgB2 sintered at high temperature and high pressure condition. The superconducting transition width for the resistivity measurement was about 0.4 K, and the low-field magnetization showed a sharp superconducting transition with a transition width of about 1 K. The resistivity in the normal state roughly followed T^2 behavior with smaller residual resistivity ratio (RRR) of 3 over broad temperature region above 100 K rather than reported T^3 behavior with larger RRR value of ~ 20 in the samples made at lower pressures. Also, the resistivity did not change appreciably with the applied magnetic field, which was different from previous report. These differences were discussed with the microscopic and structural change due to the high-pressure sintering.Comment: 2 pages, 3 figures. Accepted by Physica

Talking Past Each Other: Government, Business and Civil Society Discussing Cyber Security

Martha Finnemore has visited MGIMO-University this September, she gave several public lectures for students and participated in a number of roundtables. Professor Finnemore was very kind to give an interview to our journal on various issues of international information and cybersecurity. The interview was conducted by Elena Zinovieva, vice director of the Center for International Information Security, Science and Technology Policy at MGIMO-University

Fluxon dynamics by microwave surface resistance measurements in MgB2

Field-induced variations of the microwave surface resistance, Rs(H), have been investigated in high-density ceramic MgB2. At low temperatures, several peculiarities of the Rs(H) curves cannot be justified in the framework of models reported in the literature. We suggest that they are ascribable to the unconventional vortex structure in MgB2, related to the presence of two gaps. On the contrary, the results near Tc can be accounted for by the Coffey and Clem model, with fluxons moving in the flux-flow regime, provided that the anisotropy of the upper critical field is taken into due account.Comment: 6 pages, 4 figure

Why Was There a Harmful Algal Bloom in 2015: The Relative Growth of Toxic and Non-toxic Diatoms as a Function of Temperature

A coastwide bloom of the toxigenic diatom Pseudo-nitzschia in 2015 resulted in the largest recorded outbreak and unprecedented levels of the neurotoxin, domoic acid (DA), along the North American west coast. The scientific community has suggested that warmer ocean temperatures were the main cause of this harmful algal bloom (HAB), but little scientific evidence to support the relationship between temperature, and the growth and toxicity of Pseudo-nitzschia has been provided for local isolates of these diatoms. To gain insight into bloom dynamics, a laboratory study was conducted to examine the growth of toxic and non-toxic phytoplankton species at a range of temperatures. Non- (or low) toxic diatoms Pseudo-nitzschia fraudulenta, Skeletonema costatum, and Chaetoceros decipiens were isolated from the 2015 bloom, and cultured at eight temperature conditions (5.6, 6.8, 8.7, 10.8, 13.3, 15.2, 17.2, 19.0°C). A total of 48 cultures (6 tubes per condition), with duplicates at each temperature, were grown in a temperature gradient incubator and monitored for 31 days over three complete growth cycles (runs) of exponential and stationary growth. Specific growth rates, determined from daily measures of in vivo fluorescence, indicate that by Run 3, there was no growth at 5.6°C for Chaetoceros decipiens, and a large decline in the growth rate for Skeletonema costatum at 17.2 and 19.0°C. Pseudo-nitzschia fraudulenta demonstrated the greatest growth rates of all species from 10.8 to 19.0°C, and exhibited the broadest range of elevated growth rates. These temperature results indicate that Skeletonema costatum does not thrive in ocean temperatures above 15°C, and is outcompeted by other algae, including both species of Pseudo-nitzschia. Results of this study will greatly aid oceanographers in determining the dominant species in a coastal region as a function of ambient ocean temperature conditions

Anisotropic Superconducting Properties of MgB2 Single Crystals

In-plane electrical transport properties of MgB2 single crystals grown under high pressure of 4-6 GPa and temperature of 1400-1700oC in Mg-B-N system have been measured. For all specimens we found sharp superconducting transition around 38.1-38.3K with transition width within 0.2-0.3K. Estimated resistivity value at 40K is about 1 mkOhmcm and resistivity ratio R(273K)/R(40K) of about 4.9. Results of measurements in magnetic field up to 5.5T perpendicular to Mg and B planes and up to 9T in parallel orientation show temperature dependent anisotropy of the upper critical field with anisotropy ratio increasing from 2.2 close to Tc up to about 3 below 30K. Strong deviation of the angular dependence of Hc2 from anisotropic mass model has been also found.Comment: 10pages, including 5 figures,submitted to Physica C (in press

High Pressure Study on MgB2

The hydrostatic pressure effect on the newly discovered superconductor MgB2 has been determined. The transition temperature Tc was found to decrease linearly at a large rate of -1.6 K/GPa, in good quantitative agreement with the ensuing calculated value of -1.4 K/GPa within the BCS framework by Loa and Syassen, using the full-potential linearlized augmented plane-wave method. The relative pressure coefficient, dlnTc/dp, for MgB2 also falls between the known values for conventional sp- and d-superconductors. The observation, therefore, suggests that electron-phonon interaction plays a significant role in the superconductivity of the compound.Comment: 8 pages, 3 figures; submitted to Physical Review B (February 14, 2001; revised March 21, 2001); minor modifications, including a discussion of the preprint by Vogt et a

The Average Kinetic Energy of the Superconducting State

Isothermal magnetization curves are plotted as the magnetization times the magnetic induction, $4 \pi M \cdot B$, versus the applied field, H. We show here that this new curve is the average kinetic energy of the superconducting state versus the applied field, for type-II superconductors with a high Ginzburg-Landau parameter $\kappa$. The maximum of $4 \pi M \cdot B$ occurs at a field, $H^{*}$, directly related to the upper critical field, $H_{c2}$, suggesting that $H_{c2}(T)$ may be extracted from such plots even in cases when it is too high for direct measurement. We obtain these plots both theoretically, from the Ginzburg-Landau theory, and experimentally, using a Niobium sample with $T_c = 8.5 K$, and compare them.Comment: 11 pages, 9 postscript figure