In the paper the most recent research and development efforts made by Pulsed Technologies ltd. are presented. Design and essential characteristics of power high-voltage TDI and TPI-thyratrons (Pseudospark Switches), spark gaps, as well as X-ray tubes of the new generation are described. The report cites examples of emerging applications in leading world institutions, including high-power pulsed Electro-Physics (EP).
We report on 2.3x μm wavelength InP-based type-II distributed feedback (DFB) lasers heterogeneously integrated on a silicon photonics integrated circuit. In the devices, a III–V epitaxial layer stack with a “W”-shaped InGaAs/GaAsSb multi-quantum-well active region is adhesively bonded to the first-order silicon DFB gratings. Single mode laser emission coupled to a single mode silicon waveguide with a side mode suppression ratio of 40 dB is obtained. In continuous-wave regime, the 2.32 μm laser operates close to room temperature (above 15 °C) and emits more than 1 mW output power with a threshold current density of 1.8 kA/cm2 at 5 °C. A tunable diode laser absorption measurement of CO is demonstrated using this source.
The Na,K-ATPase is essential for the contractile function of skeletal muscle, which expresses the α1 and α2 subunit isoforms of Na,K-ATPase. The α2 isozyme is predominant in adult skeletal muscles and makes a greater contribution in working compared with noncontracting muscles. Hindlimb suspension (HS) is a widely used model of muscle disuse that leads to progressive atrophy of postural skeletal muscles. This study examines the consequences of acute (6-12 h) HS on the functioning of the Na,K-ATPase α1 and α2 isozymes in rat soleus (disused) and diaphragm (contracting) muscles. Acute disuse dynamically and isoform-specifically regulates the electrogenic activity, protein, and mRNA content of Na,K-ATPase α2 isozyme in rat soleus muscle. Earlier disuse-induced remodeling events also include phospholemman phosphorylation as well as its increased abundance and association with α2 Na,K-ATPase. The loss of α2 Na,K-ATPase activity results in reduced electrogenic pump transport and depolarized resting membrane potential. The decreased α2 Na,K-ATPase activity is caused by a decrease in enzyme activity rather than by altered protein and mRNA content, localization in the sarcolemma, or functional interaction with the nicotinic acetylcholine receptors. The loss of extrajunctional α2 Na,K-ATPase activity depends strongly on muscle use, and even the increased protein and mRNA content as well as enhanced α2 Na,K-ATPase abundance at this membrane region after 12 h of HS cannot counteract this sustained inhibition. In contrast, additional factors may regulate the subset of junctional α2 Na,K-ATPase pool that is able to recover during HS. Notably, acute, low-intensity muscle workload restores functioning of both α2 Na,K-ATPase pools. These results demonstrate that the α2 Na,K-ATPase in rat skeletal muscle is dynamically and acutely regulated by muscle use and provide the first evidence that the junctional and extrajunctional pools of the α2 Na,K-ATPase are regulated differently.
We investigate the unfolded formulation of bosonic Lorentz tensor fields ofarbitrary spin in $AdS_3$ containing a parity breaking mass parameter. Theyinclude deformations of the linearisations of the Prokushkin--Vasiliev higherspin theory around its critical points. They also provide unfolded formulationsof linearized topologically massive higher spin fields including their criticalversions. The gauge invariant degrees of freedom are captured by infinitetowers of zero forms. We also introduce two inequivalent sets of gaugepotentials given by trace constrained Fronsdal fields and trace unconstrainedmetric-like fields.
We investigate the stability of massless topological black holes in Adsd when minimally coupled to a scalar field of negative mass-squared. In many cases such black holes are unstable even though the field is above the BF bound and the geometry is locally AdS. The instability depends on the choice of boundary conditions for the scalars: scalars with non-standard (Neumann) boundary conditions tend to be more unstable, though scalars with standard (Dirichlet) boundary conditions can be unstable as well. This leads to an apparent mismatch between boundary and bulk results in the Vasiliev/vector-like matter duality.
We investigate the pressure dependence of the upper critical fields({\mu}$_0$$H$$_{c2}$) for FeSe single crystals with pressure up to 2.57 GPa.The superconducting (SC) properties show a disparate behavior across a criticalpressure where the pressure-induced antiferromagnetic phase coexists withsuperconductivity. The magnetoresistance for $H//ab$ and $H//c$ is verydifferent: for $H//c$, magnetic field induces and enhances a hump in theresistivity close to the $T_c$ for pressures higher than 1.2 GPa, while it isabsent for $H//ab$. Since the measured {\mu}$_0$$H$$_{c2}$ for FeSe samples issmaller than the orbital limited upper critical field ($H$$^{orb}$$_{c2}$)estimated by the Werthamer Helfand and Hohenberg (WHH) model, the Makiparameter ({\alpha}) related to Pauli spin-paramagnetic effects is additionallyconsidered to describe the temperature dependence of {\mu}$_0$$H$$_{c2}$($T$).Interestingly, the {\alpha} value is hardly affected by pressure for $H//ab$,while it strongly increases with pressure for $H//c$. The pressure evolution ofthe {\mu}$_0$$H$$_{c2}$(0)s for the FeSe single crystals is found to be almostsimilar to that of $T_c$($P$), suggesting that the pressure-induced magneticorder adversely affects the upper critical fields as well as the SC transitiontemperature.
We conjecture that Vasiliev's theory of higher spin gravity in four-dimensional de Sitter space (dS) is holographically dual to a three-dimensional conformal field theory (CFT) living on the spacelike boundary of dS at future timelike infinity. The CFT is the Euclidean Sp(N) vector model with anticommuting scalars. The free CFT flows under a double-trace deformation to an interacting CFT in the IR. We argue that both CFTs are dual to Vasiliev dS gravity but with different future boundary conditions on the bulk scalar field. Our analysis rests heavily on analytic continuations of bulk and boundary correlators in the proposed duality relating the O(N) model with Vasiliev gravity in AdS.
The field and temperature dependencies of the longitudinal and Hallresistivity have been measured for FeSe${}_{1-x}$S${}_{x}$ (x=0.04, 0.09 and0.19) single crystals. The sample FeSe${}_{0.81}$S${}_{0.19}$ does not show atransition to an orthorhombic phase and exhibits at low temperatures thetransport properties quite different from those of orthorhombic samples. Thebehavior of FeSe${}_{0.81}$S${}_{0.19}$ is well described by the simple twoband model with comparable values of hole and electron mobility. In particular,at low temperatures the transverse resistance shows a linear field dependence,the magnetoresistance follow a quadratic field dependence and obeys to Kohler'srule. In contrast, Kohler's rule is strongly violated for samples having anorthorhombic low temperature structure. However, the transport properties ofthe orthorhombic samples can be satisfactory described by the three band modelwith the pair of almost equivalent to the tetragonal sample hole and electronbands, supplemented with the highly mobile electron band which has two ordersmaller carrier number. Therefore, the peculiarity of the low temperaturetransport properties of the orthorhombic Fe(SeS) samples, as probably of manyother orthorhombic iron superconductors, is due to the presence of a smallnumber of highly mobile carriers which originate from the local regions of theFermi surface, presumably, nearby the Van Hove singularity points.