Isogeometric Approximation Methods Using the Interlineation Operators

Interlineation of functions of two or more variables is approximation of the functions by their traces or traces of some differential operators on the fixed system of lines. The given paper presents the analysis of the building methods of interlineation operators, that preserve the differentiability class and have the same traces as the approximated function

Use of a thin liquid film moving under the action of gas flow in a mini-channel for removing high heat fluxes

Intensively evaporating liquid films shear-driven in a mini- or micro-channel under the action of cocurrent gas flow are promising for the use in modern cooling systems of semiconductor devices. In this work, we investigated the influence of liquid and gas flow rates on the critical heat flux in a locally heated film of water, moving under the action of air flow in a mini-channel. In experiments a record value of critical heat flux of 870 W/cm{2} was reached. Heat spreading into the substrate and heat losses to the atmosphere in total do not exceed 25 % at heat fluxes above 400 W/cm{2} . A comparison with the critical heat flux for water flow boiling in the channel shows that, for shear-driven liquid films the critical heat flux is almost an order of magnitude higher

Precursors of order in aggregates of patchy particles

We study computationally the local structure of aggregated systems of patchy particles. By calculating the probability distribution functions of various rotational invariants we can identify the precursors of orientation order in amorphous phase. Surprisingly, the strongest signature of local order is observed for 4-patch particles with tetrahedral symmetry, not for 6-patch particles with the cubic one. This trend is exactly opposite to their known ability to crystallize. We relate this anomaly to the observation that a generic aggregate of patchy systems has coordination number close to 4. Our results also suggest a significant correlation between rotational order in the studied liquids with the corresponding crystalline phases, making this approach potentially useful for a broader range of patchy systems.Comment: 12 pages, 3 figure

Use of a thin liquid film moving under the action of gas flow in a mini-channel for removing high heat fluxes

Intensively evaporating liquid films shear-driven in a mini- or micro-channel under the action of cocurrent gas flow are promising for the use in modern cooling systems of semiconductor devices. In this work, we investigated the influence of liquid and gas flow rates on the critical heat flux in a locally heated film of water, moving under the action of air flow in a mini-channel. In experiments a record value of critical heat flux of 870 W/cm{2} was reached. Heat spreading into the substrate and heat losses to the atmosphere in total do not exceed 25 % at heat fluxes above 400 W/cm{2} . A comparison with the critical heat flux for water flow boiling in the channel shows that, for shear-driven liquid films the critical heat flux is almost an order of magnitude higher

Taxonomic revision of the Typhula ishikariensis complex

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Tuning the bandstructure of electrons in a two-dimensional artificial electrostatic crystal in GaAs quantum wells

The electronic properties of solids are determined by the crystal structure and interactions between electrons, giving rise to a variety of collective phenomena including superconductivity, strange metals and correlated insulators. The mechanisms underpinning many of these collective phenomena remain unknown, driving interest in creating artificial crystals which replicate the system of interest while allowing precise control of key parameters. Cold atoms trapped in optical lattices provide great flexibility and tunability [1, 2], but cannot replicate the long range Coulomb interactions and long range hopping that drive collective phenomena in real crystals. Solid state approaches support long range hopping and interactions, but previous attempts with laterally patterned semiconductor systems were not able to create tunable low disorder artificial crystals, while approaches based on Moire superlattices in twisted two-dimensional (2D) materials [3, 4] have limited tunability and control of lattice geometry. Here we demonstrate the formation of highly tunable artificial crystals by superimposing a periodic electrostatic potential on the 2D electron gas in an ultrashallow (25 nm deep) GaAs quantum well. The 100 nm period artificial crystal is identified by the formation of a new bandstructure, different from the original cubic crystal and unique to the artificial triangular lattice: transport measurements show the Hall coefficient changing sign as the chemical potential sweeps through the artificial bands. Uniquely, the artificial bandstructure can be continuously tuned from parabolic free-electron bands into linear graphene-like and flat kagome-like bands in a single device. This approach allows the formation arbitrary geometry 2D artificial crystals, opening a new route to studying collective quantum states.Comment: 30 pages, 11 figure

Geometric control of universal hydrodynamic flow in a two dimensional electron fluid

Fluid dynamics is one of the cornerstones of modern physics and has recently found applications in the transport of electrons in solids. In most solids electron transport is dominated by extrinsic factors, such as sample geometry and scattering from impurities. However in the hydrodynamic regime Coulomb interactions transform the electron motion from independent particles to the collective motion of a viscous `electron fluid'. The fluid viscosity is an intrinsic property of the electron system, determined solely by the electron-electron interactions. Resolving the universal intrinsic viscosity is challenging, as it only affects the resistance through interactions with the sample boundaries, whose roughness is not only unknown but also varies from device to device. Here we eliminate all unknown parameters by fabricating samples with smooth sidewalls to achieve the perfect slip boundary condition, which has been elusive both in molecular fluids and electronic systems. We engineer the device geometry to create viscous dissipation and reveal the true intrinsic hydrodynamic properties of a 2D system. We observe a clear transition from ballistic to hydrodynamic electron motion, driven by both temperature and magnetic field. We directly measure the viscosity and electron-electron scattering lifetime (the Fermi quasiparticle lifetime) over a wide temperature range without fitting parameters, and show they have a strong dependence on electron density that cannot be explained by conventional theories based on the Random Phase Approximation

Acid-sensing ion channel blocker diminazene facilitates proton-induced excitation of afferent nerves in a similar manner that Na+/H+ exchanger blockers do

Tissue acidification causes sustained activation of primary nociceptors, which causes pain. In mammals, acid-sensing ion channels (ASICs) are the primary acid sensors; however, Na+/H+ exchangers (NHEs) and TRPV1 receptors also contribute to tissue acidification sensing. ASICs, NHEs, and TRPV1 receptors are found to be expressed in nociceptive nerve fibers. ASIC inhibitors reduce peripheral acid-induced hyperalgesia and suppress inflammatory pain. Also, it was shown that pharmacological inhibition of NHE1 promotes nociceptive behavior in acute pain models, whereas inhibition of TRPV1 receptors gives relief. The murine skin-nerve preparation was used in this study to assess the activation of native polymodal nociceptors by mild acidification (pH 6.1). We have found that diminazene, a well-known antagonist of ASICs did not suppress pH-induced activation of CMH-fibers at concentrations as high as 25 μM. Moreover, at 100 μM, it induces the potentiation of the fibers’ response to acidic pH. At the same time, this concentration virtually completely inhibited ASIC currents in mouse dorsal root ganglia (DRG) neurons (IC50 = 17.0 ± 4.5 μM). Non-selective ASICs and NHEs inhibitor EIPA (5-(N-ethyl-N-isopropyl)amiloride) at 10 μM, as well as selective NHE1 inhibitor zoniporide at 0.5 μM induced qualitatively the same effects as 100 μM of diminazene. Our results indicate that excitation of afferent nerve terminals induced by mild acidification occurs mainly due to the NHE1, rather than acid-sensing ion channels. At high concentrations, diminazene acts as a weak blocker of the NHE. It lacks chemical similarity with amiloride, EIPA, and zoniporide, so it may represent a novel structural motif for the development of NHE antagonists. However, the effect of diminazene on the acid-induced excitation of primary nociceptors remains enigmatic and requires additional investigations

Розробка методу підвищення оперативності оцінки стану об’єкту моніторингу в інформаційних системах спеціального призначення

The peculiarities of modern military conflicts significantly increase the requirements for the efficiency of object state assessment. Therefore, it is necessary to develop algorithms (methods and techniques) that can assess the state of the monitoring object from different sources of intelligence for a limited time and with a high degree of reliability. Accurate and objective object analysis requires multi-parameter estimation with significant computational costs. That is why the following tasks were solved in the study: the formalization of the assessment of monitoring objects was carried out, a method of increasing the efficiency of assessing the condition of monitoring objects was developed and an efficiency assessment was carried out. The essence of the proposed method is the hierarchical hybridization of binary classifiers and their subsequent training. The method has the following sequence of actions: determining the degree of uncertainty, constructing a classifier tree, determining belonging to a particular class, determining object parameters, pre-processing data about the object of analysis and hierarchical traversal of the tree. The novelty of the method lies in taking into account the type of uncertainty and noise of the data and taking into account the available computing resources of the object state analysis system. The novelty of the method also lies in the use of combined training procedures (lazy training and training procedure for evolving neural networks) and selective use of system resources by connecting only the necessary types of detectors. The method allows you to build a top-level classifier using various low-level schemes for combining them and aggregating compositions. The method increases the efficiency of data processing by 12–20 % using additional advanced proceduresОсобливості сучасних воєнних конфліктів вимагають суттєво підвищують вимоги з оперативності оцінки стану об’єкту. Саме тому, необхідно проводити розробку алгоритмів (методів та методик) які здатні за обмежений час та з високим ступенем достовірності провести оцінку стану об’єкту моніторингу від різнотипних джерел розвідувальних відомостей. Точний та об’єктивний аналіз об’єкту вимагає багатопараметричної оцінки зі значними обчислювальними витратами. Саме тому в дослідженні вирішені наступні завдання, а саме: проведено формалізацію оцінки обєктів моніторингу, розроблено метод підвищення оперативності оцінювання стану обєктів моніторингу та проведено оцінку ефективності. Сутність запропонованого методу полягає в ієрархічній гібридизації бінарних класифікаторів та подальшому їх навчанні. Метод має наступну послідовність дій: визначення ступеня невизначеності, побудова дерева класифікаторів, визначення належності до певного класу, визначення параметрів об’єкту, попередня обробка даних про об’єкт аналізу та ієрархічний обхід дерева. Новизна методу полягає в врахуванні типу невизначеності та зашумленості даних та врахуванні наявних обчислювальних ресурсів системи аналізу стану об’єкту. Новизна методу також полягає у використанні комбінованих процедур навчання (ліниве навчання та процедура навчання на для штучних нейронних мереж, що еволюціонують) та вибірковим задіянням ресурсів системи за рахунок підключення тільки необхідних типів детекторів. Метод дозволяє побудувати класифікатор верхнього рівня за допомогою різних низькорівневих схем їх комбінування та агрегуючих композицій. Використання методу дозволяє досягти підвищення оперативності обробки даних на рівні 12–20 % за рахунок використання додаткових удосконалених процеду