Assessment of Arctic seasonal snow cover rates of change

Arctic snow cover extent (SCE) trends and rates of change reported across recent climate assessments vary due to the time period of available data, the selection of snow products, and methodological considerations. While all reported trends are strongly negative during spring, more uncertainty exists in autumn. Motivated to increase the confidence in SCE trends reported in climate assessments, we quantify the impact of (1) year-over-year increases in time series length over the past 2 decades, (2) the choice of reference period, (3) the application of a statistical methodology to improve inter-dataset agreement, (4) the dataset ensemble size, and (5) product version changes. Results show that the rate of change during May and June has remained consistent over the past decade as time series length has increased and is largely insensitive to the choice of reference period. Although new product versions have increased spatial resolution, use more advanced reanalysis meteorology to force snow models, and include improved remote sensing retrieval algorithms, these enhancements do not result in any notable changes in the observed rate of Arctic SCE change in any month compared to a baseline set of older products. The most impactful analysis decision involves the scaling of dataset climatologies using an updated version of the NOAA snow chart climate data record as the baseline. While minor for most months, this adjustment can influence the calculated rate of change for June by a factor of 2 relative to different climatological baselines.</p

Complex magnetism of lanthanide intermetallics unravelled

We explain a profound complexity of magnetic interactions of some technologically relevant gadolinium intermetallics using an ab-initio electronic structure theory which includes disordered local moments and strong $f$-electron correlations. The theory correctly finds GdZn and GdCd to be simple ferromagnets and predicts a remarkably large increase of Curie temperature with pressure of +1.5 K kbar$^{-1}$ for GdCd confirmed by our experimental measurements of +1.6 K kbar$^{-1}$. Moreover we find the origin of a ferromagnetic-antiferromagnetic competition in GdMg manifested by non-collinear, canted magnetic order at low temperatures. Replacing 35\% of the Mg atoms with Zn removes this transition in excellent agreement with longstanding experimental data.Comment: 11 pages, 4 figure

Influence of the starting temperature of calorimetric measurements on the accuracy of determined magnetocaloric effect

Availability of a restricted heat capacity data range has a clear influence on the accuracy of calculated magnetocaloric effect, as confirmed by both numerical simulations and experimental measurements. Simulations using the Bean-Rodbell model show that, in general, the approximated magnetocaloric effect curves calculated using a linear extrapolation of the data starting from a selected temperature point down to zero kelvin deviate in a non-monotonic way from those correctly calculated by fully integrating the data from near zero temperatures. However, we discovered that a particular temperature range exists where the approximated magnetocaloric calculation provides the same result as the fully integrated one. These specific truncated intervals exist for both first and second order phase transitions and are the same for the adiabatic temperature change and magnetic entropy change curves. The effect of this truncated integration in real samples was confirmed using heat capacity data of Gd metal and Gd5Si2Ge2 compound measured from near zero temperatures

Electrical resistivity and magnetoresistance of single-crystal Tb5Si2.2Ge1.8

A positive colossal magnetoresistance (CMR) of 160% has been observed in Tb5Si2.2Ge1.8 with the magnetic field applied parallel to the a axis. When the magnetic field is applied parallel to the b and c axes, the magnetoresistance (MR) is less than 8% and 5%, respectively. The CMR effect originates from intrinsic crystallographic phase coexistence. The anisotropy of the MR effect is due to a unique geometric arrangement of the interphase boundaries and large magnetocrystalline anisotropy of the compound

Magnetic and structural properties of single-crystalline Er5Si4

The magnetization of the oriented Er5Si4 single crystal, measured along the three principal crystallographic directions, reveals strong magnetocrystalline anisotropy. The b axis is the easy magnetization direction. The possible presence of the crystal-field effect and the noncollinear alignment of magnetic moments result in a lower than gJ magnetization along all crystallographic directions, even in a 70-kOe applied magnetic field, with the lowest moment (4.22 μB/Er3+) recorded along the a axis. The magnetization measurements show that even in the true paramagnetic state there is a weak magnetic field dependence of the structural-only transition when the field is applied along the a and c axes, but this transition is magnetic field independent along theb axis in fields of 70 kOe or less. The temperature- and magnetic-field-dependent x-ray powder diffraction study of the powdered single crystal confirms the temperature-driven structural orthorhombic-monoclinic transition in the paramagnetic state and the low-temperature magnetic-field-driven monoclinic-orthorhombic transition in the magnetically ordered state. The x-ray powder diffraction indicates that the high-temperature transition is magnetic field independent below 40 kOe in a polycrystalline sample while the low-temperature transition requires a high magnetic field for its completion

Magnetic and magnetocaloric properties of DyCo2Cx alloys

The magnetic and magnetocaloric properties of DyCo2Cx (x = 0, 0.05, 0.1, and 0.15) alloys were investigated. The results show that the Curie temperature (TC) of the DyCo2Cx alloys increases with increasing C content, from 136 K (x = 0) to 152 K (x = 0.15), but the lattice parameter a of DyCo2Cx exhibits a maximum at x = 0.05. The suppression of the ac susceptibility of DyCo2Cx at low temperature indicates the enhancement of the domain wall pinning effect by carbon doping. The positive slops of the Arrott plots of the doped compounds indicate that the phase transition is second order for the carbon-doped alloys, and the maximum value of the isothermal magnetic entropy change (ΔSM) for the magnetic field change of 50 kOe decreases from −13.9 J/kg· K (x = 0) to −7.8 J/kg·K (x = 0.15). The relative cooling power (RCP) of DyCo2Cx is nearly the same in all studied alloys, while the temperature-averaged entropy change over 10 K temperature span, TEC(10), indicates decreasing magnetocaloric performance of carbon doped materials

ВИКОРИСТАННЯ АКТИВНИХ ФОРМ НАВЧАННЯ ТА СУЧАСНИХ ІНФОРМАТИВНИХ ТЕХНОЛОГІЙ ЯК ЗАСОБУ ІНТЕНСИФІКАЦІЇ НАВЧАЛЬНОГО ПРОЦЕСУ

The article provides information on the features of the use of learning active forms and modern informative technologies in teaching the discipline “Children’s Infectious Diseases” at the Department of Children’s Diseases with Pediatric Surgery of the I.&nbsp;Horbachevsky Ternopil National Medical University of the Ukrainian Health Ministry. The article reflects many years experience in the teaching and methodological work of the faculty of the department using the principles of personality-oriented learning, the specifics of teaching the discipline in the context of reforming the health system. The use of active forms of training and modern computer technologies contribute to the intensification of the educational process, make it possible to approximate the conditions for teaching students in clinical practice and to fully reveal the individual cognitive abilities of each. Optimization of the infectious diseases teaching and the basics of immunoprophylaxis in children by medical students is the basis for improving the results of treatment of patients and conducting preventive measures to prevent infectious diseases.У статті подано інформацію щодо особливостей використання активних форм навчання (рольові ігри, кейс-метод) та сучасних інформативних технологій у викладанні циклу «Дитячі інфекційні хвороби» на кафедрі дитячих хвороб з дитячою хірургією Тернопільського національного медичного університету імені І. Я. Горбачевського МОЗ України. Відображено багаторічній досвід навчально-методичної роботи професорсько-викладацького складу кафедри з використанням принципів особистісно-орієнтованого навчання, специфіку викладання дисципліни в умовах реформування системи охорони здоров’я. Використання активних форм навчання та сучасних комп’ютерних технологій сприяють інтенсифікації навчального процесу, дозволяють максимально наблизити умови навчання студентів до клінічних, повною мірою дати розкритися індивідуальним пізнавальним здібностям кожного. Оптимiзацiя викладання інфекційних захворювань та основ імунопрофілактики в дітей студентам-медикам є основою для покращення результатів лікування хворих та проведення профілактичних заходiв щодо запобігання інфекційним захворюванням