Transit navigation through Northern Sea Route from satellite data and CMIP5 simulations

Rapid Arctic sea ice decline over the last few decades opens new perspectives for Arctic marine navigation. Further warming in the Arctic will promote the Northern Sea Route (NSR) as an alternative to the conventional Suez or Panama Canal routes for intercontinental shipping. Here we use both satellite data and CMIP5 ensemble of climate models to estimate the NSR transit window allowing intercontinental navigation between Atlantic and Pacific regions. To this end, we introduce a novel approach to calculate start and end dates of the navigation season along the NSR. We show that modern climate models are able to reproduce the mean time of the NSR transit window and its trend over the last few decades. The selected models demonstrate that the rate of increase of the NSR navigation season will slow down over the next few decades with the RCP4.5 scenario. By the end of the 21st century ensemble-mean estimates show an increase of the NSR transit window by about 4 and 6.5 months according to RCP4.5 and 8.5, respectively. Estimated trends for the end date of the navigation season are found to be stronger compared to those for the start date

Effective Light-weight Masonry Mortars with Dispersed Reinforcement

AbstractThe article is devoted to the development of masonry mortars with hollow ceramic microspheres and reinforcing fibers with improved properties. The mortars with ceramic microspheres and light-weight masonry mortars based on them have low average density, low thermal conductivity, high compressive strength, high specific strength, but insufficient crack resistance, frost resistance and mortar durability. One way of improvement of the properties of such mortars is the introduction of dispersed reinforcing fibers into their structure. In this study, the following types of fibers were used: basalt ones, glass ones, chrysotile ones and two types of polymer fibers – polyacrylic and polypropylene ones. The basic properties of mortar mixtures and mortar have been determined; the dependences of the influence of consumption of various fiber types on the basic properties of mortars have been studied, primarily, on the average density, compressive strength and tensile bending strength. The optimum composition of the masonry mortars with hollow ceramic microspheres and fibers were obtained, the results of microstructural analysis of the samples are given

Recent Flight Test Results of the Joint CIAM-NASA Mach 6.5 Scramjet Flight Program

Under a contract with NASA, a joint Central Institute of Aviation Motors (CIAM) and NASA team recently conducted the fourth flight test of a dual-mode scramjet aboard the CIAM Hypersonic Flying Laboratory, 'Kholod'. With an aim test Mach 6.5 objective, the successful launch was conducted at the Sary Shagan test range in central Kazakstan on February 12, 1998. Ground-launch, rocket boosted by a modified Russian SA5 missile, the redesigned scramjet was accelerated to a new maximum velocity greater than Mach 6.4. This launch allowed for the measurement of the fully supersonic combustion mode under actual flight conditions. The primary program objective was the flight-to-ground correlation of measured data with preflight analysis and wind-tunnel tests in Russia and potentially in the United States. This paper describes the development and objectives of the program as well as the technical details of the scramjet and SA5 redesign to achieve the Mach 6.5 aim test condition. An overview of the launch operation is also given. Finally, preliminary flight test results are presented and discussed

Insulation systems for structures on pile supports

Construction on problem soils or in permafrost conditions involves using of pile foundations with a ventilated space under the floor structure. In this case, additional thermal insulation is required under the first-floor structure (above the ventilated space). The aim of research was to develop insulation systems for buildings on pile foundations for different climatic zones, including conditions of the arctic region and other regions with a predominance of ever-frozen ground. With the help of the THERM computer program, the conditions of bidimensional heat interchange in the enclosing structures of a building with pile foundation were simulated. The resulting models were analysed in terms of the thermophysical characteristics of the structures. As a result, the optimal version of the insulation system was chosen, effective both in the climatic conditions of the midland and in the especially cold conditions of Yakutia and Trans-Polar region (The Subarctic). This system included insulation with mineral wool slabs along the facade walls, with extruded foamed polystyrene along the basement part and the floor structure, and with rolled foamed polyethylene (with the formation of a seamless insulation shell) along the ventilated space under the floor structure and above, on top of insulation boards

Shear driven FC-72 liquid film flow on the heater with microgrooves

The crisis in a FC-72 liquid film moving under the action of a gas flow through a smooth and micro-grooved heater was experimentally investigated. It is shown that the use of micro-grooves leads to an increase of the critical heat flux

Reactive co-sputter deposition of nanostructured cermet anodes for solid oxide fuel cells

The impact of a nanostructured NiO/yttria-stabilized zirconia (NiO/YSZ) and NiO/gadolinia-doped ceria (NiO/GDC) anode functional layers on low- and intermediate-temperature solid oxide fuel cell (SOFC) performance is investigated. NiO/YSZ and NiO/GDC thin films were reactively sputter-deposited by pulsed direct current magnetron sputtering from the Ni, Zr–Y, and Ce–Gd targets onto commercial NiO/YSZ substrates. Anode-supported SOFCs based on magnetron sputtered YSZ and GDC electrolytes (~4 µm) with and without the nanostructured anode layers are fabricated. A direct comparison of the YSZ- and GDC-based SOFCs in temperature range of 600–800 and 400–600 °C is made. The performance of cells with the nanostructured anode layers significantly increases as compared to that of the cell without it, especially at lower temperatures. Increase of cells performance was achieved by reduction of the total area-specific resistance by 26–30%

Magnetron sputtered LSC thin films for solid oxide fuel cell application

In this study, La0.6Sr0.4CoO3-d (LSC) thin films were deposited by pulsed DC magnetron sputtering at oblique angle of the LSC target. The effect of post-annealing temperature in the range of 600-1000°C on the film crystalline structure was investigated. The phase composition, crystalline structure and surface morphology of the films were determined using X-ray diffraction, scanning electron microscopy and atomic force microscopy, respectively. Anode-supported solid oxide fuel cells (SOFCs) with bi-layered thin-film yttria-stabilized zirconia (YSZ) / gadolinium-doped ceria (GDC) electrolyte and an LSC thin film interlayer were fabricated. Polarization curves were measured in the temperature range from 700 to 800°C. It was shown that the LSC interlayer improves SOFC power density. Our results demonstrate that magnetron sputtering provides a low-temperature synthesis route for realizing thin LSC films for intermediate-temperature SOFCs

Insulation Systems of Frame Cottages

• The article presents studies of the exploitation characteristics of the material, the results of a full-scale survey of a residential private house insulated with expanded polyethylene, as well as the main design solutions for the insulation of a frame cottage. The features of insulation systems of low-rise buildings, including those with a frame-bearing carrier system, are considered. It has been substantiated that the use as thermal insulation of mineral-wool plates used on non-loaded structures assumes the mandatory placement of vapor barrier (usually plastic film) from the inside of the insulated surface and the windproof membrane outside. The use of a rolled foamed polyethylene as an insulating material makes it possible to realize an insulating sheath without additional layers. Experimental determinations of diffusion moisture absorption, water absorption upon partial immersion in water, water absorption upon full immersion in water, tensile strength in the longitudinal direction, and adhesion strength of the adhesive layer to metal were performed. It was established that the diffusion moisture absorption of samples of expanded polyethylene is 0.51-0.75%, and taking into account the weld it is 0.70-0.75%. Water absorption of samples when fully immersed in water does not exceed 0.96% by volume. The tensile strength in the longitudinal direction for products with a metallized coating is 80-92 kPa, without a metallized coating - 80-87 kPa, and for a weld - 29-32 kPa. A field survey showed that the humidity of the pine timber is within the normative. The expediency of warming only the outer coating of expanded polyethylene of the calculated thickness without filling the frame is justified, which, with standard air exchange and observance of the conditioning conditions, will be sufficient to maintain the microclimate in the room

Probing anomalous off-shell electroweak dipole moment of the top quark

A possibility to search for anomalous Wtb interaction ∂μWμ−b¯ f W L P L + f W R P R t is considered for the first time. Despite such couplings do not contribute to both pair top quark production or three main electroweak production modes, they could provide non-zero contributions to associated single top quark production with W or Z bosons or in association with two forward light jets via electroweak fusion diagrams