Optical switching performance of thermally oxidized vanadium dioxide with an integrated thin film heater

Optical switching performance of vanadium dioxide produced by thermal oxidation of vanadium is presented in this paper. A 100nm thick vanadium was oxidized under controlled conditions in a quartz tube furnace to produce approximately 200nm thick VO2. The substrate was appropriately coated on the front and back side to reduce reflection in the cold state, and an integrated thin film heater was fabricated to allow in-situ thermal cycling. Electrical measurements show a greater than three orders of magnitude change in resistivity during the phase transition. Optical measurements exhibit 70% transparency at 1500nm and about 15dB extinction across a wide spectral band between 1000nm and 3000nm. These results are used to show a huge optical bistability effect in VO2-based devices

Single-Walled Carbon Nanotube Network Field Effect Transistor as a Humidity Sensor

Single-walled carbon nanotube network field effect transistors were fabricated and studied as humidity sensors. Sensing responses were altered by changing the gate voltage. At the open channel state (negative gate voltage), humidity pulse resulted in the decrease of the source-drain current, and, vice versa, the increase in the source-drain current was observed at the positive gate voltage. This effect was explained by the electron-donating nature of water molecules. The operation speed and signal intensity was found to be dependent on the gate voltage polarity. The positive or negative change in current with humidity pulse at zero-gate voltage was found to depend on the previous state of the gate electrode (positive or negative voltage, respectively). Those characteristics were explained by the charge traps in the gate dielectric altering the effective gate voltage, which influenced the operation of field effect transistor.Peer reviewe

Improving vehicle adaptability to the operating conditions of "smart" cities in the northern regions

The paper reviews a relevant problem of providing a higher quality of people’s living in the northern regions by the application of the modern technologies within transport in order to improve its environmental performance and efficiency. The aim of the research is to substantiate methods of increasing the adaptability of vehicles to variable low-temperature operating conditions based on a neural control system of preheating and maintaining the optimum temperature of technological fluids by SHF radiation and improving diesel fuel properties by introducing a multifunctional additive. It has been found that SHF radiation influences the physical and chemical parameters of diesel fuel, as well as the engine output parameters. SHF radiation results in a reduction of fuel consumption to 7%, smoke from the exhaust to 15%, and nitrogen oxide emission to 30%. A conclusion is made that using SHF radiation for technological fuel preheating is essential. An approach has been developed that improves low-temperature properties of diesel fuels and increases engine operation efficiency under severe climatic conditions by introducing a multifunctional additive. The additive will enable a significant decrease in fuel consumption under low-temperature operating conditions and a complex improvement of fuel properties

The origins and spread of domestic horses from the Western Eurasian steppes

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture

The analysis of the electric vehicle charging infrastructure in Tyumen city

The development of electric vehicles, which is also observed in the Russian Federation at present, leads to the need to create a charging infrastructure. Variable operating conditions, and in particular low ambient temperature, cause difficulties in the use of electric vehicles, which are associated with a low power reserve and increased energy consumption in the winter. These features of the electric vehicle operation in the Russian Federation can lead to an increase in the number of charging stations needed to create a developed infrastructure, and, therefore, can increase capital costs. The purpose of this research is to identify patterns of the electric vehicle charging station operation in the regional infrastructure using the example of Tyumen city to develop a methodology for calculating their quantity that can satisfy demand in variable climatic conditions with a low capital cost. As a result of this study, patterns of change in the number of charging sessions, its duration and the amount of energy transferred to electric vehicles from the ambient temperature were obtained

Evaluation of the traffic signal regulation efficiency of crossroads with unstable transport demand by time

The article describes the results of the research, whose goal is to assess the effectiveness of the traffic light operation at crossroads with unstable transport demand in terms of time and directions. The modern way of cities development consists in creation of sustainable, and, hence, safe, harmless and comfortable environment for residing. This determines the separation of urban and industrial areas, the creation of transport infrastructure, in particular crossroads, which are equipped with traffic lights. As a rule, it is characterized by unstable transport demand in the direction of entry and exit from the territory of enterprises, which causes an inadvertent increase in the idle time of vehicles in the main direction. In the course of experimental studies, the authors found that the crossroads under consideration are parts of the road network that connect the industrial and urban areas, which causes a high traffic intensity in the main areas. At the same time, the share of ineffective resolving phase for entry and exit from the territory of the enterprise reaches 70-80%, which increases the idle time of vehicles in the main direction. The authors proposed an indicator that characterizes the proportion of inefficient operation of the traffic signal

Device for Transplanting Young Undergrowth with Soil Lump When Performing Forestry

The designs of devices for transplanting young undergrowth from under the forest canopy are considered. Patent search methods were used. Particular attention is paid to the designs of devices that allow digging outplanting with a soil lump in the form of a hemisphere and capturing a clod of earth from two sides. The proposed design allows you to upgrade these devices and reduce the likelihood of damage to the dug undergrowth. The device is recommended for replanting coniferous young undergrowth up to 1 meter high during forestry work