Tunable local polariton modes in semiconductors

We study the local states within the polariton bandgap that arise due to deep defect centers with strong electron-phonon coupling. Electron transitions involving deep levels may result in alteration of local elastic constants. In this case, substantial reversible transformations of the impurity polariton density of states occur, which include the appearance/disappearance of the polariton impurity band, its shift and/or the modification of its shape. These changes can be induced by thermo- and photo-excitation of the localized electron states or by trapping of injected charge carriers. We develop a simple model, which is applied to the $O_P$ center in $GaP$. Further possible experimental realizations of the effect are discussed.Comment: 7 pages, 3 figure

Architectural Support for Scalable High-Bandwidth I/O

The number of cores in modern-day processors keeps growing and it has already reached hundreds of cores per socket. This trend, combined with improvements in virtualization technologies, results in many independent tenants sharing a single server. Available local server interconnect and network bandwidth is growing as well, moving to a terabit per second speeds. Efficient link and processor utilization in environments with thousands of tenants sharing an I/O device introduces unique challenges and requires rethinking existing hardware architectures. As the number of tenants increases, contention for shared resources can degrade total performance. In this thesis, compute environments with many independent tenants sharing a single server are referred to as hyper-tenant environments. A high-bandwidth network requires significant CPU involvement to handle transport protocol operations. In cloud datacenters, these CPU resources can also be sold to customers running their applications. Therefore, datacenter providers need to decrease CPU involvement in network transport protocol operations. This can be achieved by performing common protocol operations in hardware. However, there are multiple transport protocols used in datacenters. On top of that, the hardware design should support thousands of connections due to the high workload consolidation ratio. This thesis presents an analysis of current I/O address translation schemes and studies of their scalability in hyper-tenant setups. Based on the conclusion from the analysis, it introduces a new design for hyper-tenant I/O address translation. Furthermore, this thesis describes a new trace-based simulator, which allows us to study various system parameters. This thesis describes the architecture of scalable hardware units used to perform the common operations between multiple network protocols to offload a portion of the networking stack from software on general purpose a processor to hardware. The units are combined into a configurable design, which supports thousands of concurrent flows and can fully utilize a 100Gb/s link. Finally, this thesis covers an I/O interface for communication between a hardware testbench and a host machine. The presented design can execute both assembly tests and an operating system without physical access to hardware across a variety of platforms to enable automated testing

INCREASING EFFICIENCY OF CONTINUOUS POWER SUPPLY SYSTEMS FOR MICROPROCESSOR CONTROL FACILITIES

The digital models of the continuous power supply system (CPSS)-consumer have been developed, the methods for optimization of the load-carrying CPSS capacity and the methods for investigations of the dynamic CPSS characteristics have been proposed. The recommendations on the construction of the microprocessor CPSS control facilities have been given, the GPSS optimization has been performed that permitted to increase the load-carrying capacity of CPSS by 30-50%, the dynamic characteristics of CPSS have been investigated. The digital models, optimization methods and investigations of the dynamic CPSS characteristics have been introduced in the Association of Engineering and Technical Higher Schools of Russian Federation. Application field: developments and investigations of CPSS for microprocessor control facilitiesAvailable from VNTIC / VNTIC - Scientific & Technical Information Centre of RussiaSIGLERURussian Federatio

Detection of Fusarium infected seeds of cereal plants by the fluorescence method.

Infection of seeds of cereal plants with fusarium affects their optical luminescent properties. The spectral characteristics of excitation (absorption) in the range of 180-700 nm of healthy and infected seeds of wheat, barley and oats were measured. The greatest difference in the excitation spectra of healthy and infected seeds was observed in the short-wave range of 220-450 nm. At the same time, the excitation characteristics of infected seeds were higher than those of healthy ones, and the integral parameter Η in the entire range was 10-56% higher. A new maximum appeared at the wavelength of 232 nm and the maximum value increased by 362 nm. The spectral characteristics were measured when excited by radiation at wavelengths of 232, 362, 424, 485, 528 nm and the luminescence fluxes were calculated. It is established that the photoluminescence fluxes Φ in the short-wave ranges of 290-380 nm increase by 1.58-3.14 times and 390-550 nm-by 1.44-2.54 times. The fluxes in longer wavelength ranges do not change systematically and less significantly: for wheat, they decrease by 12% and increase by 19%, for barley, they decrease by 10% and increase by 33%. The flux decreases by 43-71% for oats. Based on the results obtained for cereal seeds, it is possible to further develop a method for detecting fusarium infection with absolute measurements of photoluminescence fluxes in the range of 290-380 nm, or when measuring photoluminescence ratios: for wheat seeds when excited with wavelengths of 424 nm and 232 nm (Φ424/Φ232); for barley seeds-when excited with wavelengths of 485 nm and 232 nm (Φ485/Φ232) and for oat seeds-when excited with wavelengths of 424 nm and 362 nm (Φ424/Φ362)

Complex Spectroscopic Study for Fusarium Genus Fungi Infection Diagnostics of “Zalp” Cultivar Oat

At present, one of the critical problems in agriculture is the identification of cereals, including oats, infected by Fusarium spp. genus fungi. Timely diagnostics can prevent the further disease spread and help to identify the already stored infected grains. In this regard, the aim of this work is to develop the spectroscopic approaches that determine the infected grains. As an object of the investigation the “Zalp” cultivar oat, both healthy and infected grains of the 2020 harvest were chosen. The spectroscopic diagnostics included FTIR in the mid-IR region, Raman, and luminescence methods. Combination of chemometric tools with FTIR and Raman spectroscopy allowed obtaining approaches based on identified characteristic spectral features which may be used as infection markers. These approaches make it possible to detect the infection on the grain husk. The carotenoid type fungi pigment was identified within the resonance conditions of Raman scattering excitation. The luminescence study of infected oat husk revealed the presence of characteristic chlorophyll α peak which is absent in healthy grain husk

Enabling Programmable Transport Protocols in High-Speed NICs

Data-center network stacks are moving into hardware to achieve 100 Gbps data rates and beyond at low latency and low CPU utilization. However, hardwiring the network stack in the NIC would stifle innovation in transport protocols. In this paper, we enable programmable transport protocols in high-speed NICs by designing Tonic, a flexible hardware architecture for transport logic. At 100 Gbps, transport protocols must generate a data segment every few nanoseconds using only a few kilobits of per-flow state on the NIC. By identifying common patterns across transport logic of different transport protocols, we design an efficient hardware "template" for transport logic that satisfies these constraints while being programmable with a simple API. Experiments with our FPGA-based prototype show that Tonic can support the transport logic of a wide range of protocols and meet timing for 100 Gbps of back-to-back 128-byte packets. That is, every 10 ns, our prototype generates the address of a data segment for one of more than a thousand active flows for a downstream DMA pipeline to fetch and transmit a packet

Ursus etruscus from the late Early Pleistocene of the Taurida сave (Crimean Peninsula)

Altres ajuts: CERCA Programme/Generalitat de CatalunyaThe present work describes the dentognathic remains of Ursus etruscus Cuvier, 1823 from the recently discovered Taurida cave in central Crimea at the north Black Sea area. The bone-bearing layer of Taurida cave corresponds to the Psekupsian Faunal Assemblage of Eastern Europe and to the Late Villafranchian of Western Europe (ca. 1.8-1.5 Ma). Here, we describe unpublished ursid material unearthed during the excavations performed at the cave in 2020-2021, further comparing it with coeval chronologic and geographic sites around Europe. Our anatomical and biometrical analyses suggest the inclusion of the studied specimens in the hypodigm of the Early Pleistocene medium-sized species Ursus etruscus. The finds of the U. etruscus from the southern part of Eastern Europe provide a link between the western and eastern parts of the species range. Therefore, the finds from Crimea are important for understanding of the morphological diversity and evolution of U. etruscus which is the putative ancestor of both cave bears and brown bears. Furthermore, the study of these remains is also important for understanding the processes of the forming of the large mammal assemblages in the late Early Pleistocene and its relationships with the dispersal of the genus Homo

Synchrotron and Neutron Tomography of Paleontological Objects on the Facilities of the Kurchatov Institute

The most important results of tomographic studies of paleontological objects on the facilities of the National Research Centre “Kurchatov Institute” are described. It is shown that the use of the synchrotron and neutron tomography makes it possible to obtain new information on the structure of fossil animals, which is of fundamental importance for taxonomy and morphological analysis of extinct fauna

Determination of Main Spectral and Luminescent Characteristics of Winter Wheat Seeds Infected with Pathogenic Microflora

In connection with the constant growth of demand for high-quality food products, there is a need to develop effective methods for storing agricultural products, and the registration and predicting infection in the early stages. The studying of the physical properties of infected plants and seeds has fundamental importance for determining crop losses, conducting a survey of diseases, and assessing the effectiveness of their control (assessment of the resistance of crops and varieties, the effect of fungicides, etc.). Presently, photoluminescent methods for diagnosing seeds in the ultraviolet and visible ranges have not been studied. For research, seeds of winter wheat were selected, and were infected with one of the most common and dangerous diseases for plants—fusarium. The research of luminescence was carried out based on a hardware–software complex consisting of a multifunctional spectrofluorometer “Fluorat-02-Panorama”, a computer with software “Panorama Pro” installed, and an external camera for the samples under study. Spectra were obtained with a diagnostic range of winter wheat seeds of 220–400 nm. Based on the results obtained for winter wheat seeds, it is possible to further develop a method for determining the degree of fusarium infection