Flood Hazard Modelling in Upper Mandakini Basin of Uttarakhand

Floods in Himalayan region raise serious concerns regarding ongoing path of development as recent manifestations of catastrophic events establish link between climate changes and risk to anthropogenic activities in mountainous regions. Scientists predict frequent occurrence of such disasters wherein rapid glacial melting; incidents of glacial lake outburst and weather extremes may trigger floods in the Himalayan mountains. This paper examined flood risk in Upper Mandakini basin through GIS based flood simulationto highlight flood potential and risk associated with such hazard in the study area.It is observed that floods in study area display hazardous interplay of natural terrain gradient, high kinetic energy of streams, and intense rainfall. The upper sections of basin that includes Kali Ganga, Mandani Ganga, Madhyamaheshwar and Mandakini rivers shows high flood susceptibility with greatest risk in the latter. Such hazardousness is likely to be intensified by ongoing anthropogenic activities in the basin.

Laser Assisted Catalytic Growth of Silicon Nanowires Using Gold and Nickel Catalysts

Laser assisted synthesis of silicon nanowires (SiNWs) was successfully achieved through the use of gold and nickel as catalysts. The diameter of the resulting SiNWs was found to be dependent on that of the catalyst in the case of gold catalyst. The gold catalysed silicon nanowires were unevenly curved and branched owing to the high kinetic energy possessed by gold nanoparticles (AuNPs) at relatively high processing temperature. The use of nickel as catalyst resulted in the formation of several SiNWs on a single nickel catalyst crystallite due to interconnection of the nickel metal crystallites at processing temperature. The morphology of SiNWs catalysed by both nickel and gold was controlled by optimising the laser energy during ablation.

Sandwich Structures for Energy Absorption Applications: A Review

It is crucial that proper engineering structures are designed as energy absorbers for high dynamic loading situations, such as accidents, blasts, or impacts. The role of such structures is to absorb the high kinetic energy as strain energy through irreversible deformation of the structure. Many types of energy absorbers were designed for different dynamic high strain rate applications. One of these structures are sandwich structures. The aim of this review paper is to provide a general review on the type of sandwich structures that have been designed as energy absorbers and their performance in crashworthiness and blast related applications. The focus is on the type of core structures being used, namely foam and architected cores. It was found from the review that sandwich structures are viable candidates for such applications not only because of their light weight, but also due to the high-energy absorption capabilities. The work presented in this review paper shows that the data from the literature on this topic are vast and do not converge to any particular sandwich structure design. This presents the potential future research direction in designing sandwich structures, which have wider application at different scales.

ДЕТОНАЦІЙНО-ГАЗОВЕ ЗМІЦНЕННЯ ДЕТАЛЕЙ ДВИГУНІВ ВНУТРІШНЬОГО ЗГОРАННЯ

The paper deals with improving the reliability and durability of parts of the cylinder-piston group of internal combustion engines. Strengthening of machine parts is possible through the use of special production processes. Modern materials and coatings must be able to meet high operating temperatures and loads.Chrome plating, boriding and ion-plasma spraying do not meet the established quality requirements. The aluminum piston suffers damage in the head area. This manifests itself in the accumulation of cracks, channels, and traces of alloy washout. In addition, due to heating, the strength of the aluminum alloy becomes worse more than 2 times.It is proposed to create and use a coating that would withstand operating temperatures of more than 2000°C, as well as shock-pulsating loads. A detonation-gas spraying method is proposed. It is characterized by the versatility of materials and can be applied to polymers and to refractory ceramics, as well as to any metals and alloys.The deposited particles have high kinetic energy. The coating is characterized by high strength, which reaches 180 ... 200 MPa, hardness HRCe 60, and minimal cracks. The temperature effect during spraying on the workpiece is negligible. A sequence of preparatory operations is proposed. The piston and glow ring on the UN-102 detonation-gas installation were to be strengthened. A manipulator was used that uses the energy of the installation shot.The resulting surfaces are characterized by a regular macrostructure (waviness). A nickel-aluminum alloy was applied. Coating thickness was about 150 ... 270 microns, hardness was of HV 550, adhesion to the base eas of 94 ... 100 MPa. The results of studies on the parts of the cylinder-piston group showed a decrease in operating temperatures due to the running-in of the coating and high-quality sealing of the combustion chamber.The durability of the rings is 1.6·106…2.3·106, which indicates a significant increase in fatigue resistance and service life. The proposed technology is suitable and recommended for implementation in mass production

What Food will We be Eating in Space in the Future?

The aim of this article is to show the potential of space flight and related research. The authors analyze the conditions of space flight and the associated possible threats that may occur. It is assumed that the basic problem is cosmic radiation, which not only can significantly affect the health of astronauts, but also prevent potential cultivation of plants or animal breeding on board a spacecraft. The solution to this problem proposed in the article is a shield which provides re-sistance to collisions with high kinetic energy particles, while reducing the speed of corpuscular radiation. An important part of the article is a detailed analysis of various biotechnological and bioengineering methods that could be used for food production on board a spacecraft. The au-thors indicate that technological development in the field of bioprinting or genetic modification of organisms may play a key role in the success of long-distance technological missions. Moreover, the organisms mentioned in the work, such as algae, fungi and insects, are indicated as a potential source of energy for future colonizers. In sum, the research covers both the field of engineering and biotechnology, as well as the possibility of checking these technological methods in the test flights.

Development of a focused high-energy macromolecular ion beam

The development of a focused macromolecular ion beam with kinetic energy of up to 110 keV. This is the first report of both a focused and high-kinetic-energy protein ion beam.