Evidence for Adiabatic Magnetization of cold Dy_N Clusters

Magnetic properties of Dy_N clusters in a molecular beam generated with a liquid helium cooled nozzle are investigated by Stern-Gerlach experiments. The cluster magnetizations \mu_z are measured as a function of magnetic field (B = 0 - 1.6T) and cluster size (16 < N < 56). The most important observation is the saturation of the magnetization \mu_z(B) at large field strengths. The magnetization approaches saturation following the power law |\mu_z-\mu_0| proportional to 1/\sqrt{B}, where \mu_0 denotes the magnetic moment. This gives evidence for adiabatic magnetization.Comment: 4 pages, 3 figure

Expert consensus statements for the management of COVID-19-related acute respiratory failure using a Delphi method.

Coronavirus disease 2019 (COVID-19) pandemic has caused unprecedented pressure on healthcare system globally. Lack of high-quality evidence on the respiratory management of COVID-19-related acute respiratory failure (C-ARF) has resulted in wide variation in clinical practice. Using a Delphi process, an international panel of 39 experts developed clinical practice statements on the respiratory management of C-ARF in areas where evidence is absent or limited. Agreement was defined as achieved when &gt; 70% experts voted for a given option on the Likert scale statement or &gt; 80% voted for a particular option in multiple-choice questions. Stability was assessed between the two concluding rounds for each statement, using the non-parametric Chi-square (χ &lt;sup&gt;2&lt;/sup&gt; ) test (p &lt; 0·05 was considered as unstable). Agreement was achieved for 27 (73%) management strategies which were then used to develop expert clinical practice statements. Experts agreed that COVID-19-related acute respiratory distress syndrome (ARDS) is clinically similar to other forms of ARDS. The Delphi process yielded strong suggestions for use of systemic corticosteroids for critical COVID-19; awake self-proning to improve oxygenation and high flow nasal oxygen to potentially reduce tracheal intubation; non-invasive ventilation for patients with mixed hypoxemic-hypercapnic respiratory failure; tracheal intubation for poor mentation, hemodynamic instability or severe hypoxemia; closed suction systems; lung protective ventilation; prone ventilation (for 16-24 h per day) to improve oxygenation; neuromuscular blocking agents for patient-ventilator dyssynchrony; avoiding delay in extubation for the risk of reintubation; and similar timing of tracheostomy as in non-COVID-19 patients. There was no agreement on positive end expiratory pressure titration or the choice of personal protective equipment. Using a Delphi method, an agreement among experts was reached for 27 statements from which 20 expert clinical practice statements were derived on the respiratory management of C-ARF, addressing important decisions for patient management in areas where evidence is either absent or limited. The study was registered with Clinical trials.gov Identifier: NCT04534569

A Real-Space Approach to Electronic Transport

Using orthogonal polynomials, a novel approach for studying DC and AC conductivity and velocity-velocity correlation function has been developed. The method works in direct space and can treat order or disordered, finite or infinite, and pure or alloy systems with equal ease. Further, it is not computer intensive and allows conductivity calculations as a function of frequency or the location of the Fermi energy in an efficient manner

ON THE BULK AND SURFACE ELECTRONIC STRUCTURE OF AMORPHOUS TRANSITION METALS

Amorphous metals are characterized by the absence of a long range periodicity as well as the presence of a local disorder. The study of their electronic properties requires an understanding of the relation between the local disorder and the local electronic structure. In this work, we have carried out calculations on local density of d-states for bulk and surface of amorphous metals using moments method within tight-binding framework, in conjunction with various existing geometrical models. Our results show that the dominant factor governing the local density of states is the strength and shape of the first peak of the local radial distribution function. In the bulk where this local distribution has only small deviations from the average value, the density of states has a double peaked structure with peaks becoming sharper as the first maxima becomes stronger and peaked. As one goes to the surface, the decrease in the first coordination number leads to a merging tendency towards a single central peak. These calculations have been used to investigate some physical properties like the resistivity, thermoelectric power and the cohesive energy in amorphous materials

Structure of liquid transition and rare earth metals

It is shown that the observed structure factors of transition and rare earth liquid metals can be reasonably simulated by a one component plasma (OCP) model. The simulated OCP model has been used to calculate the temperature coefficient of resistivity in liquid transition metals and good agreement with experiment has been obtained.On montre que les résultats expérimentaux des facteurs de structure des métaux de transition et terres rares liquides sont raisonnablement décrits par un modèle de plasma (OCP). Ce modèle est utilisé aussi pour calculer le coefficient de température de la résistivité des métaux de transition liquides. Les résultats sont en bon accord avec l'expérience