Application of Pareto and Ishikawa Diagrams for Identification of Dangerous Production Factors

Приведены результаты анализа возможности применением для идентификации опасных и вредных производственных факторов диаграмм Парето и Исакавы. Показано, что применение диаграмм позволяет выявить значимые и приоритетные факторы, что позволяет целенаправленно направлять материальные ресурсы на улучшение условий труда и повышение безопасности на рабочих местах.The results of the analysis of the possibility of using Pareto and Isakawa diagrams to identify dangerous and harmful production factors are presented. It is shown that the use of diagrams allows us to identify significant and priority factors, which allows us to purposefully direct material resources to improve working conditions and improve safety in the workplace

TRANSPORT AND THE GREENHOUSE EFFECT

The article presents the results of the analysis of the impact of carbon dioxide emissions from diesel locomotive exhaust gases on the formation of the greenhouse effect. It is shown that the role of rail transport is very noticeable and carbon dioxide emissions into the environment should be taken into account in general greenhouse gas emissions.В статье приведены результаты анализ воздействия выброса углекислого газа с отработавшими газами тепловозов на образование парникового эффекта. Показано, что роль железнодорожного транспорта весьма заметна и выбросы углекислого газа в окружающую среду следует учитывать в общем выбросы парниковых газов

Real Time Electron Tunneling and Pulse Spectroscopy in Carbon Nanotube Quantum Dots

We investigate a Quantum Dot (QD) in a Carbon Nanotube (CNT) in the regime where the QD is nearly isolated from the leads. An aluminum single electron transistor (SET) serves as a charge detector for the QD. We precisely measure and tune the tunnel rates into the QD in the range between 1 kHz and 1 Hz, using both pulse spectroscopy and real - time charge detection and measure the excitation spectrum of the isolated QD.Comment: 12 pages, 5 figure

A valley-spin qubit in a carbon nanotube

Although electron spins in III-V semiconductor quantum dots have shown great promise as qubits, a major challenge is the unavoidable hyperfine decoherence in these materials. In group IV semiconductors, the dominant nuclear species are spinless, allowing for qubit coherence times that have been extended up to seconds in diamond and silicon. Carbon nanotubes are a particularly attractive host material, because the spin-orbit interaction with the valley degree of freedom allows for electrical manipulation of the qubit. In this work, we realise such a qubit in a nanotube double quantum dot. The qubit is encoded in two valley-spin states, with coherent manipulation via electrically driven spin resonance (EDSR) mediated by a bend in the nanotube. Readout is performed by measuring the current in Pauli blockade. Arbitrary qubit rotations are demonstrated, and the coherence time is measured via Hahn echo. Although the measured decoherence time is only 65 ns in our current device, this work offers the possibility of creating a qubit for which hyperfine interaction can be virtually eliminated

Waste of Reinforced Concrete Products in Railway Transport as a Material Resource

При эксплуатации железных дорог образуется много отходов - в официальном классификаторе их не менее шестисот. На сегодняшний день большой проблемой является утилизация железобетонных изделий с истекшим сроком эксплуатации. Принцип разумного расхода и оптимизации бюджета заключается в повторном использовании железобетонных изделий на железнодорожном транспорте, если они не утратили своих функциональных свойств. Это означает, что вместо утилизации часть изделий можно повторно использовать на железной дороге, в производстве или быту повторно.When operating railways, a lot of waste is generated - there are at least six hundreds of them in the official classifier. To date, a big problem is the disposal of reinforced concrete products with expired service life. The principle of reasonable expenditure and budget optimization is the reuse of reinforced concrete products in railway transport, if they have not lost their functional properties. This means that instead of recycling, some of the products can be reused on the railway, in production or in everyday life

Tunable few-electron double quantum dots and Klein tunnelling in ultra-clean carbon nanotubes

Quantum dots defined in carbon nanotubes are a platform for both basic scientific studies and research into new device applications. In particular, they have unique properties that make them attractive for studying the coherent properties of single electron spins. To perform such experiments it is necessary to confine a single electron in a quantum dot with highly tunable barriers, but disorder has until now prevented tunable nanotube-based quantum-dot devices from reaching the single-electron regime. Here, we use local gate voltages applied to an ultra-clean suspended nanotube to confine a single electron in both a single quantum dot and, for the first time, in a tunable double quantum dot. This tunability is limited by a novel type of tunnelling that is analogous to that in the Klein paradox of relativistic quantum mechanics.Comment: 21 pages including supplementary informatio

Electrical control over single hole spins in nanowire quantum dots

Single electron spins in semiconductor quantum dots (QDs) are a versatile platform for quantum information processing, however controlling decoherence remains a considerable challenge. Recently, hole spins have emerged as a promising alternative. Holes in III-V semiconductors have unique properties, such as strong spin-orbit interaction and weak coupling to nuclear spins, and therefore have potential for enhanced spin control and longer coherence times. Weaker hyperfine interaction has already been reported in self-assembled quantum dots using quantum optics techniques. However, challenging fabrication has so far kept the promise of hole-spin-based electronic devices out of reach in conventional III-V heterostructures. Here, we report gate-tuneable hole quantum dots formed in InSb nanowires. Using these devices we demonstrate Pauli spin blockade and electrical control of single hole spins. The devices are fully tuneable between hole and electron QDs, enabling direct comparison between the hyperfine interaction strengths, g-factors and spin blockade anisotropies in the two regimes

Semiconductor Spintronics

Spintronics refers commonly to phenomena in which the spin of electrons in a solid state environment plays the determining role. In a more narrow sense spintronics is an emerging research field of electronics: spintronics devices are based on a spin control of electronics, or on an electrical and optical control of spin or magnetism. This review presents selected themes of semiconductor spintronics, introducing important concepts in spin transport, spin injection, Silsbee-Johnson spin-charge coupling, and spindependent tunneling, as well as spin relaxation and spin dynamics. The most fundamental spin-dependent nteraction in nonmagnetic semiconductors is spin-orbit coupling. Depending on the crystal symmetries of the material, as well as on the structural properties of semiconductor based heterostructures, the spin-orbit coupling takes on different functional forms, giving a nice playground of effective spin-orbit Hamiltonians. The effective Hamiltonians for the most relevant classes of materials and heterostructures are derived here from realistic electronic band structure descriptions. Most semiconductor device systems are still theoretical concepts, waiting for experimental demonstrations. A review of selected proposed, and a few demonstrated devices is presented, with detailed description of two important classes: magnetic resonant tunnel structures and bipolar magnetic diodes and transistors. In most cases the presentation is of tutorial style, introducing the essential theoretical formalism at an accessible level, with case-study-like illustrations of actual experimental results, as well as with brief reviews of relevant recent achievements in the field.Comment: tutorial review; 342 pages, 132 figure