Принципы построения сетевых систем обнаружения вторжений на базе ПЛИС

The common principles of FPGA-based NIDS (Network Intrusion Detection Systems) construction are investigated. The main requirements and characteristics of such systems are discussed. The generalized structure of a reconfigurable NIDS is described

Анализ способов и устройств для уплотнения мелкофракционных шихт

Выполнен анализ способов уплотнения мелкофракционных сыпучих материалов. Предложена схема уплотнения на основе валковых прессов с многоступенчатым уплотнением

Magnetic Fields, Relativistic Particles, and Shock Waves in Cluster Outskirts

It is only now, with low-frequency radio telescopes, long exposures with high-resolution X-ray satellites and gamma-ray telescopes, that we are beginning to learn about the physics in the periphery of galaxy clusters. In the coming years, Sunyaev-Zeldovich telescopes are going to deliver further great insights into the plasma physics of these special regions in the Universe. The last years have already shown tremendous progress with detections of shocks, estimates of magnetic field strengths and constraints on the particle acceleration efficiency. X-ray observations have revealed shock fronts in cluster outskirts which have allowed inferences about the microphysical structure of shocks fronts in such extreme environments. The best indications for magnetic fields and relativistic particles in cluster outskirts come from observations of so-called radio relics, which are megaparsec-sized regions of radio emission from the edges of galaxy clusters. As these are difficult to detect due to their low surface brightness, only few of these objects are known. But they have provided unprecedented evidence for the acceleration of relativistic particles at shock fronts and the existence of muG strength fields as far out as the virial radius of clusters. In this review we summarise the observational and theoretical state of our knowledge of magnetic fields, relativistic particles and shocks in cluster outskirts.Comment: 34 pages, to be published in Space Science Review

Scanning electron microscope-cathodoluminescence (SEM-CL) imaging of planar deformation features and tectonic deformation lamellae in quartz

Planar deformation features (PDFs) in quartz are essential proof for the correct identification of meteorite impact structures and related ejecta layers, but can be confused with tectonic deformation lamellae. The only completely reliable method to demonstrate the shock origin of suspected (sub-) planar microstructures, transmission electron microscope (TEM) observations, is costly and time consuming. We have used a cathodoluminescence (CL) detector attached to a scanning electron microscope (SEM) to image both PDFs and tectonic deformation lamellae in quartz to demonstrate the potential of a simple method to identify PDFs and define characteristics that allow their distinction from tectonic deformation lamellae. In both limited wavelength grayscale and composite color SEM-CL images, PDFs are easily identified. They are straight, narrow, well-defined features, whereas tectonic deformation lamellae are thicker, slightly curved, and there is often no clear boundary between lamella and host quartz. Composite color images reveal two types of CL behavior in PDFs: either they emit a red to infrared CL signal or they are nonluminescent. The color of the CL signal emitted by tectonic deformation lamellae ranges from blue to red. For comparison, we also imaged several shocked quartz grains at cryogenic temperature. In most cases, the PDF characteristics in cryo-CL images do not differ significantly from those in images recorded at room temperature. We conclude that SEM-CL imaging, especially when color composites are used, provides a promising, practical, low cost, and nondestructive method to distinguish between PDFs and tectonic lamellae, even when the simplest CL techniques available are used

Shocked quartz in the SEM: Distinction between amorphous and healed PDFs

Combined SEM techniques show that different CL signatures of PDFs are related to fresh and healed microstructures of PDFs and host quartz. This is confirmed by TEM results. A combination of SEM techniques can give the same type of information as TE

The Guarda structure (Portugal): Impact structure or not? Microstructural studies of Quartz, Zircon and Monazite

The Guarda Structure in north-eastern Portugal has been proposed as a potential impact structure. We have studied the structure in detail, but no field or microscopic evidence has been found to support the impact hypothesi

The Othris Ophiolite, Greece: A snapshot of subduction initiation at a mid-ocean ridge

The mantle section of the Tethyan-type Othris Ophiolite, Greece, records tectono-magmatic processes characteristic of both mid-ocean ridges and supra-subduction zones. The Othris Ophiolite is a remnant of the Jurassic Neotethys Ocean, which existed between Eurasia and Gondwanaland. Othris peridotites range from fertile plagioclase lherzolites to depleted harzburgites. Abundances of A

Upper mantle viscosity and lithospheric thickness under Iceland

Deglaciation during the Holocene on Iceland caused uplift due to glacial isostatic adjustment. Relatively low estimates for the upper mantle viscosity and lithospheric thickness result in rapid uplift responses to the deglaciation cycles on Iceland. The relatively high temperatures of the upper mantle under the newly formed mid-ocean ridge under Iceland are responsible for the low upper mantle viscosity values. In this study, estimates for lithospheric thickness and upper mantle viscosity under Iceland from glacial isostatic adjustment studies are complemented by a microphysical modelling approach using the theoretical temperature distribution under mid-ocean ridges combined with olivine diffusion and dislocation creep flow laws. The lithospheric thickness (27–40 km) and upper mantle viscosity (2 × 1018–1019 Pa s) outcomes for the upper mantle recent glaciation under the Vatnajökull glacier are consistent with previous reports of viscosity and lithospheric thickness from glacial isostatic adjustment studies. A combination of a 40 km thick elastic lithosphere and an average upper mantle viscosity of 5 ×1018 Pa s would suggest that the upper mantle under Iceland is most likely dry. The earlier and larger Weichselian glaciation event (∼10,000 BP) on Iceland is predicted to have had a slightly larger upper mantle viscosity ∼1019 Pa s and a lithospheric thickness of ∼100 km. Large lateral variations in upper mantle viscosity and especially lithospheric thickness are expected for Iceland perpendicular to the ridge axis

Upper mantle viscosity and lithospheric thickness under Iceland

Deglaciation during the Holocene on Iceland caused uplift due to glacial isostatic adjustment. Relatively low estimates for the upper mantle viscosity and lithospheric thickness result in rapid uplift responses to the deglaciation cycles on Iceland. The relatively high temperatures of the upper mantle under the newly formed mid-ocean ridge under Iceland are responsible for the low upper mantle viscosity values. In this study, estimates for lithospheric thickness and upper mantle viscosity under Iceland from glacial isostatic adjustment studies are complemented by a microphysical modelling approach using the theoretical temperature distribution under mid-ocean ridges combined with olivine diffusion and dislocation creep flow laws. The lithospheric thickness (27–40 km) and upper mantle viscosity (2 × 1018–1019 Pa s) outcomes for the upper mantle recent glaciation under the Vatnajökull glacier are consistent with previous reports of viscosity and lithospheric thickness from glacial isostatic adjustment studies. A combination of a 40 km thick elastic lithosphere and an average upper mantle viscosity of 5 ×1018 Pa s would suggest that the upper mantle under Iceland is most likely dry. The earlier and larger Weichselian glaciation event (∼10,000 BP) on Iceland is predicted to have had a slightly larger upper mantle viscosity ∼1019 Pa s and a lithospheric thickness of ∼100 km. Large lateral variations in upper mantle viscosity and especially lithospheric thickness are expected for Iceland perpendicular to the ridge axis