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The force-driven Poiseuille flow of dense gases between two parallel plates is investigated through the numerical solution of the generalized Enskog equation for two-dimensional hard discs. We focus on the competing effects of the mean free path ${\\it\\lambda}$ , the channel width $L$ and the disc diameter ${\\it\\sigma}$ . For elastic collisions between hard discs, the normalized mass flow rate in the hydrodynamic limit increases with $L/{\\it\\sigma}$ for a fixed Knudsen number (defined as $Kn={\\it\\lambda}/L$ ), but is always smaller than that predicted by the Boltzmann equation. Also, for a fixed $L/{\\it\\sigma}$ , the mass flow rate in the hydrodynamic flow regime is not a monotonically decreasing function of $Kn$ but has a maximum when the solid fraction is approximately 0.3. Under ultra-tight confinement, the famous Knudsen minimum disappears, and the mass flow rate increases with $Kn$ , and is larger than that predicted by the Boltzmann equation in the free-molecular flow regime; for a fixed $Kn$ , the smaller $L/{\\it\\sigma}$ is, the larger the mass flow rate. In the transitional flow regime, however, the variation of the mass flow rate with $L/{\\it\\sigma}$ is not monotonic for a fixed $Kn$ : the minimum mass flow rate occurs at $L/{\\it\\sigma}\\approx 2{-}3$ . For inelastic collisions, the energy dissipation between the hard discs always enhances the mass flow rate. Anomalous slip velocity is also found, which decreases with increasing Knudsen number. The mechanism for these exotic behaviours is analysed.

Storage-class memory (SCM) combines the benefits of a solid-state memory, such as high performance and robustness, with the archival capabilities and low cost of conventional hard-disk magnetic storage. Such a device would require a solid-state nonvolatile memory technology that could be manufactured at an extremely high effective areal density using some combination of sublithographic patterning techniques, multiple bits per cell, and multiple layers of devices. We review the candidate solid-state nonvolatile memory technologies that potentially could be used to construct such an SCM. We discuss evolutionary extensions of conventional flash memory, such as SONOS (silicon-oxide-nitride-oxide-silicon) and nanotraps, as well as a number of revolutionary new memory technologies. We review the capabilities of ferroelectric, magnetic, phase-change, and resistive random-access memories, including perovskites and solid electrolytes, and finally organic and polymeric memory. The potential for practical scaling to ultrahigh effective areal density for each of these candidate technologies is then compared. [PUBLICATION ABSTRACT]

In view of the shortcomings of pulse radar signals that are easily affected by internal and external conditions, a pulse radar signal calibrator is designed based on FPGA. The radar's transmitted signals are pulsed by the calibrator in real time, and the radar signals can be calibrated by inversion analysis. At the same time, the functions of timing reception of the status information of each extension and saving of the collected data to the USB mobile hard disk are controlled by the host computer. After testing, the measurement accuracy error caused by the transmission path during the radar system's working process can be calibrated by this radar signal calibrator, the accuracy of the radar system link is improved, and the accuracy of the radar system measurement is guaranteed. Therefore, it can be widely used in ground calibration equipment of pulse radar.

The dream of replacing rotating mechanical storage, the disk drive, with solid-state, nonvolatile RAM may become a reality in the near future. Approximately ten new technologies-collectively called storage-class memory (SCM)-are currently under development and promise to be fast, inexpensive, and power efficient. Using SCM as a disk drive replacement, storage system products will have random and sequential I/O performance that is orders of magnitude better than that of comparable disk-based systems and require much less space and power in the data center. In this paper, we extrapolate disk and SCM technology trends to 2020 and analyze the impact on storage systems. The result is a 100- to 1,000-fold advantage for SCM in terms of the data center space and power required. [PUBLICATION ABSTRACT]

Colloidal particles suspended in liquid crystals can exhibit various effective anisotropic interactions that can be tuned and utilized in self-assembly processes. We simulate a two-dimensional system of hard disks suspended in a solution of dense hard needles as a model system for colloids suspended in a nematic lyotropic liquid crystal. The novel event-chain Monte Carlo technique enables us to directly measure colloidal interactions in a microscopic simulation with explicit liquid crystal particles in the dense nematic phase. We find a directional short-range attraction for disks along the director, which triggers chaining parallel to the director and seemingly contradicts the standard liquid crystal field theory result of a quadrupolar attraction with a preferred 45 ∘ angle. Our results can be explained by a short-range density-dependent depletion interaction, which has been neglected so far. Directionality and strength of the depletion interaction are caused by the weak planar anchoring of hard rods. The depletion attraction robustly dominates over the quadrupolar elastic attraction if disks come close. Self-assembly of many disks proceeds via intermediate chaining, which demonstrates that in lyotropic liquid crystal colloids depletion interactions play an important role in structure formation processes.

High-strength, colorless glass–ceramics in the MgO/Al 2 O 3 /SiO 2 system with high concentrations of ZrO 2 and a great potential for technical application, e.g., as high-performance hard disc substrates, are investigated. ZrO 2 concentrations from 6 to 9 mol% are added to a stoichiometric cordierite glass to investigate the influence of the concentration of the nucleating agent on the crystallization behavior and the mechanical properties. The phase formation and the microstructure of the glass–ceramics are studied using X-ray diffraction and scanning electron microscopy including electron backscatter diffraction. It is shown that the volume crystallization of ZrO 2 , a low-/high-quartz solid solution (low-/high-QSS), and spinel is accompanied by the surface crystallization of indialite. This phase offers a much smaller coefficient of thermal expansion than the other crystal phases, which may induce high compressive stresses in the surface layer of the glass–ceramics after cooling and seems to result in excellent mechanical properties of the material. Biaxial flexural strengths of up to 1 GPa were measured. Higher ZrO 2 concentrations reduce the surface crystallization of indialite and decrease the mean size of the crystals resulting in a higher translucency. The volume-crystallizing phases and the mechanical properties of the glass–ceramics do not seem to be significantly affected by the analyzed ZrO 2 concentrations.

Using Brownian dynamics simulations, we investigate the response to shear of a two-dimensional system of quasi-hard disks that are confined in the velocity gradient direction by a smooth external potential. Shearing the confined system leads to a homogenization of the one-body density profile. In order to rationalize this deconfinement effect, we split the internal one-body force field into adiabatic and superadiabatic contributions. We demonstrate that the superadiabatic force field consists of viscous and of structural contributions. We give an empirical scaling law that yields results for the superadiabatic force profiles both in the flow and in the gradient direction, in excellent agreement with the simulation data.

. The necessary conditions to derive the quantum Van der Waals (VdW) equation of state (EoS) with hard-core repulsion from the quantum partition are discussed for the one-component case. This EoS is obtained in the grand canonical and canonical variables, and its standard virial representation with the quantum virial coefficients is given. The multicomponent formulation of the quantum VdW EoS with hard-core repulsion is derived within a self-consistent approximation which allows one to recover the classical virial coefficients of higher order. For practical applications the latter EoS is simplified, extended to higher densities and generalized to the case of hard convex bodies of any dimension D ≥ 2 .

The popularity of Big Data applications places pressures on storage systems to efficiently scale to meet the demand. At the same time, new developments like solid-state drives have changed to traditional storage hierarchy. Cloud storage systems are transitioning towards a hybrid architecture consisting of large amounts of memory, solid-state disks (SSDs), and traditional magnetic hard disks (HD). This paper presents elasticity aware deduplication (EAD), a data deduplication framework designed for multi-tier cloud storage architectures consisting of SSD and HD. EAD dynamically adjusts the deduplication parameters at runtime in order to improve performance. Experimental results indicate that EAD is able to detect more than 98% of all duplicate data, but it only consumes less than 5% of expected memory space. Additionally, EAD saves approximately 74% of overall IO access cost compared to the traditional design.