46 research outputs found
Le développement de la construction touristique et de repos dans les Bieszczady Polonaises
W artykule przedstawiono zarys rozwoju budownictwa turystyczno-wypoczynkowego
w Bieszczadach Polskich z podziałem na dwa okresy: przedwojenny
i powojenny. Autor omawia powstanie ważniejszych obiektów turystycznych,
charakteryzując ich lokalizację oraz standard. Pracę kończy ogólna analiza współczesnego
rozmieszczenia obiektów turystycznych w polskiej części Bieszczadów
Spin transfer torque oscillator based on asymmetric magnetic tunnel junctions
We present a study of the spin transfer torque oscillator based on
CoFeB/MgO/CoFeB asymmetric magnetic tunnel junctions. We observe microwave
precession in junctions with different thickness of the free magnetization
layer. Taking advantage of the ferromagnetic interlayer exchange coupling
between the free and reference layer in the MTJ and perpendicular interface
anisotropy in thin CoFeB electrode we demonstrate the nanometer scale device
that can generate high frequency signal without external magnetic field
applied. The amplitude of the oscillation exceeds 10 nV/Hz^0.5 at 1.5 GHz.Comment: 4 pages, 4 figures, to be submitted to Applied Physics Letter
Buffer influence on magnetic dead layer, critical current and thermal stability in magnetic tunnel junctions with perpendicular magnetic anisotropy
We present a thorough research on Ta/Ru-based buffers and their influence on
features crucial from the point of view of applications of MTJs, such as
critical switching current and thermal stability. We investigate devices
consisting of buffer/FeCoB/MgO/FeCoB/Ta/Ru multilayers for three different
buffers: Ta 5 / Ru 10 / Ta 3, Ta 5 / Ru 10 / Ta 10 and Ta 5 / Ru 20 / Ta 5 (all
thicknesses in nm). In addition, we study systems with a single FeCoB layer
deposited above as well as below the MgO barrier. The crystallographic texture
and the roughness of the buffers are determined by means of XRD and atomic
force microscopy measurements. Furthermore, we examine the magnetic domain
pattern, the magnetic dead layer thickness and the perpendicular magnetic
anisotropy fields for each sample. Finally, we investigate the effect of the
current induced magnetization switching for nanopillar junctions with lateral
dimensions ranging from 1 {\mu}m down to 140 nm. Buffer Ta 5 / Ru 10 / Ta 3,
which has the thickest dead layer, exhibits a large increase in the thermal
stability factor while featuring a slightly lower critical current density
value when compared to the buffer with the thinnest dead layer Ta 5 / Ru 20 /
Ta 5
Inductive determination of the optimum tunnel barrier thickness in magnetic tunnelling junction stacks for spin torque memory applications
We use pulsed inductive microwave magnetometry to study the precessional
magnetization dynamics of the free layer in CoFeB/MgO/CoFeB based magnetic
tunnelling junction stacks with varying MgO barrier thickness. From the field
dependence of the precession frequency we are able to derive the uniaxial
anisotropy energy and the exchange coupling between the free and the pinned
layer. Furthermore the field dependence of the effective damping parameter is
derived. Below a certain threshold barrier thickness we observe an increased
effective damping for antiparallel orientation of free and pinned layer which
would inhibit reversible low current density spin torque magnetization
reversal. Such inductive measurements, in combination with wafer probe station
based magneto transport experiments, allow a fast determination of the optimum
tunnel barrier thickness range for spin torque memory applications in a
lithography free process.Comment: 22 pages, 5 figure
Neurological symptoms in hospitalised patients with COVID-19 and their association with in-hospital mortality
Objectives. To evaluate the spectrum of neurological symptoms in patients with COVID-19 during the first 14 days of hospitalisation and its association with in-hospital mortality. Material and methods. We included 200 patients with RT-PCR-confirmed COVID-19 admitted to University Hospital in Krakow, Poland. In 164 patients, a detailed questionnaire concerning neurological symptoms and signs was performed prospectively within 14 days of hospitalisation. In the remaining 36 patients, such questionnaires were completed retrospectively based on daily observations in the Department of Neurology. Results. During hospitalisation, 169 patients (84.5%) experienced neurological symptoms; the most common were: fatigue (62.5%), decreased mood (45.5%), myalgia (43.5%), and muscle weakness (42.5%). Patients who died during hospitalisation compared to the remainder were older (79 [70.5–88.5] vs. 63.5 [51–77] years, p = 0.001), and more often had decreased level of consciousness (50.0% vs. 9.3%, p < 0.001), delirium (33.3% vs. 4.4%, p < 0.001), arterial hypotension (50.0% vs. 19.6%, p = 0.005) or stroke during (18.8% vs. 3.3%, p = 0.026) or before hospitalisation (50.0% vs. 7.1, p < 0.001), whereas those who survived more often suffered from headache (42.1% vs. 0%, p = 0.012) or decreased mood (51.7% vs. 0%, p = 0.003).
Conclusions. Most hospitalised patients with COVID-19 experience neurological symptoms. Decreased level of consciousness, delirium, arterial hypotension, and stroke during or before hospitalisation increase the risk of in-hospital mortality