bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of long-term operation of the steam boiler live-steam outlet header and assessment of the feasibility of the header operation during accelerated start-ups
Authors: Węglowski Bohdan , Pilarczyk Marcin
Published: December 2019

The energy mix in most European countries is now characterized by a growing share of renewable energy sources (RES). The random nature of RES entails the need to balance the differences between the current amount of power generated in the system and the actual power demand. For this reason, power units incorporating steam boilers are most often operated under sub-peak rather than base load regimes. This creates many challenges to boiler operators due to the advanced age of the power units in service. In Poland, for instance, 77% of power units are more than 20 years old and 45% have been working for more than 30 years, which means that most of them are approaching their design life time. Further operation of these units requires a detailed analysis of the degree of wear of critical pressure components, including a thermal and mechanical stress-state analysis. The paper aims to present a methodology of wear degree calculations incorporated in the power unit control system. The performed calculations are based on real measurement data obtained from 8 months of operation of a boiler unit with the steam output of 650·103 kg/h. Wear degree calculations and a thermal and mechanical FEM-based analysis are performed to assess the possibility of shortening start-ups to address the dynamic requirements that power units operating in the Polish power generation system will have to meet.
Sizing of biomass-fired ORC cogeneration unit within coal-fired municipal heating plant back fitting project
Authors: Kalina Jacek , Świerzewski Mateusz
Published: December 2019

The problem discussed in this paper is optimal sizing of biomass-fired ORC cogeneration units into existing coal-fired district heating plants under given site-specific technical, economic and ecological constraints. In this paper the municipal heating plant in Krosno (Poland) is taken into account as the reference case. Basing on the operational experiences from this unit an optimisation study has been performed in order to examine the influence of current economic and legal conditions on the optimal design characteristics of the plant. Different electricity, biomass and coal prices are taken into account as well as the influence of the EUA (European Emission Allowance) price is examined. There are taken into account thermal energy storage and sale of electricity on balancing market. It has been found that in the studied case the implementation of hot water storage tank moves the optimal electric power output slightly towards higher values. On the other hand only a small improvement of financial performance has been gained. The results reveal importance of the optimisation of design parameters as well as the dependence of the plant’s size and structure on local economic conditions.
Virtual power plants - types and development opportunities
Authors: Przychodzień Arkadiusz
Published: December 2019

Modern power engineering meets new challenges. With the development of new energy production and storage technologies, creates new demands for energy services. To support this development, it is necessary to implement new teleinformatic systems that will allow for resource management. Such systems are called Virtual Power Plants (VPP). There are many definitions of this type of solutions due to the very wide range of possible applications. VPPs can be developed by many types of entities, e.g. distribution system operators, electricity generators, energy clusters. The ability to build a system based on modules allows you to customize the system to user’s needs. An opportunity for the development of VPP will be a package “Clean energy for all Europeans” (so called “Winter package”) that introduces regulations that allow for the development of renewable energy sources, including prosumers, and enables an active participation in the energy market for energy consumers. In addition, more stringent requirements for balancing production and energy consumption are introduced, requiring greater balancing accuracy.
Quantity and Quality of Dual Fuel IC Marine Engine Exhaust Sensible Waste Heat Considering Different Sulphur Content in Fuels
Authors: Przybyła Mateusz , Adamkiewicz Andrzej
Published: December 2019

Maritime transport is facing a significant set of technical challenges due to planned by the International Maritime Organization implementation of ecological criterions on 01 January 2020 and 2021 regarding the emission of sulphur oxides, carbon dioxide and nitrogen oxides. The advantageous properties of natural gas (NG) as fuel in conjunction with dual fuel (DF) internal combustion (IC) engines potentially enables the fulfilment of all planned criterions. However, if the methane emission of DF IC is taken into consideration in CO2 emission balance it completely devaluates the advantages arising from high hydrogen to carbon ratio of NG. On the other hand, the planned global sulphur cap in combination with its low content in NG potentially enables to recover higher rates of waste heat and exergy of combustion products without the risk of low temperature corrosion (compared to liquid fuel). In this study the influence of sulphur content in NG and pilot fuel on the sulphuric acid condensation temperature was investigated in order to determine the rate of waste heat (quantity) and exergy (quality) of four stroke DF IC engine combustion products. In ideal process scenario (exergy based) the methane slip effect compensation was achieved only for a 0,5 engine load.
Major repair and reconstruction of the historical housing development in Saint Petersburg
Authors: Tokunova Galina , Drozdova Irina , Shesterov Evgeny
Published: December 2019

The article provides results of housing technical state examination in the historical development of Saint Petersburg, performed by experts of the Saint Petersburg State University of Architecture and Civil Engineering. The described methodology developed by the authors serves a basis to find the most efficient solution for issues arising in Saint Petersburg, and fully meets all social, scientific, technical and economic conditions of modern urban development. This is especially important when implementing the concepts of Smart City and Smart Home intended to become a basis for development of modern urban environment within the existing historical city. As for cultural heritage sites, it is possible to extend the useful life of a historical building by its timely reconstruction. Reconstruction shall be performed following a clear plan with account for the sequence of stages: from handing archive materials and a city plan to identify the historical appearance of a building to a possible need for reconstruction of not only a separate building but also a whole block. In case of a major repair of an apartment building, or reconstruction of historical cultural heritage sites, activities improving energy efficiency of buildings are required, which are associated with significant costs that sometimes exceed the federal or city budget.
little-known facts about silicate bricks and fires
Authors: Ibragimov Alexandr
Published: December 2019

The article presents a brief historical background about the epistemology of silicate brick. Well-known facts about silicate brick are given: the technological scheme of manufacture, modern grades for strength and frost resistance, information about thermal conductivity, classification by species, size and purpose. Advantages are considered, among which are noted: relatively low cost, environmental friendliness, compatibility with masonry mortars, aesthetics, wide color gamut, good geometric parameters, high strength characteristics, good soundproof ability, relatively high frost resistance, ease of processing. Disadvantages are given, among which are noted: high thermal conductivity, high water absorption, brittleness, and instability to acidic and alkaline aggressive environments. Particular attention is given to the consideration of the behavior of silicate brick and masonry from it in a fire. References to works devoted to this problem are given. The research of high temperature effects on the brickwork of the silicate bricks in the fire was held. A model for the possible collapse of brickwork as a re-sult of reducing its bearing ability due to fire was designed. The conclusion is drawn about the need for technical diagnostics of the structures of buildings made of silicate brick exposed to fire, as well as the special tactics of extinguishing fires in such buildings.
Eco-efficiency of passive solar heating
Authors: Klevets Ksenia , Dvoretsky Alexander , Spiridonov Alexander
Published: December 2019

The article presents calculations of the energy efficiency of direct solar heating and sunspace, located on the building facades of various orientations, in the climatic conditions of the southern coast of Crimea. The share of compensation for heat losses due to passive solar heating has been determined. The calculation of the environmental effect of passive solar heating systems has been done.
Study of dust particle size distribution in the air of work areas at cement production facilities
Authors: Menzelintseva Nadezhda , Karapuzova Natalia , Redhwan Awadh M. , Fomina Ekaterina
Published: December 2019

The particle size distribution of dust in the air of the work area has been determined for some cement plant shops. An experimental study has been conducted to explore the effects of microclimate parameters on the dust particle size distribution on the shop floor in the cement milling shop and cement packing shop, and regression equations have been obtained. A mathematical model has been developed to forecast the dust particle size distribution in the air of work areas of cement plants.
Disposal of waste generated during drinking water disinfection with electrolytic sodium hypochlorite
Authors: Skryabin A.Yu.
Published: December 2019

The present article is concerned with the problems of recycling and reuse of waste generated in the electrolytic production of sodium hypochlorite at water treatment plants. New engineering solutions aimed at ensuring environmental safety and lack of waste during large-scale production of sodium hypochlorite from aqueous solutions of common table salt are recommended herein.
Dust concentration in the urban environment air depending on traffic intensity and time of year (on the example of the Volgograd city)
Authors: Dobrinskiy D.R. , Nikolenko D.A. , Vasil’ev A.N. , Gorshkov E.V. , Azarov V.N.
Published: December 2019

Measurements of the small-dispersed dust concentration on 50 roads intersections in morning and evening, in winter and spring periods in the Volgograd city. A comparative analysis of the small-dispersed dust concentration in morning and evening is carried out, and the results, obtained in winter and spring, are compared. Methods to reduce dust emission from the roadway are proposed.
Dispersion analysis of carbon monoxide concentrations in the linear cities atmospheric air
Authors: Ivanova Julia , Sokolova Ekaterina , Azarov Valery , Martynova Elizaveta
Published: December 2019

Volgograd belongs to a number of cities in which a linear planning structure was formed, stretching along the Volga River for almost 100 km, however, the width of Volgograd in some sections ranges from 3 to 10 km. The total area outlined by the borders is 400 km2, Volgograd has a “loose” structure, as a result, the territory occupied by residential quarters is almost 3 times smaller. In the city there are gaps between the districts, which are occupied by green areas and wastelands. In Volgograd, large green space arrays prevail on the ravines and gullies slopes, which are widespread in the city, as well as in watershed areas, while having a soil-protective and water-regulating value. Moreover, in general, in Volgograd, the area of green areas is much less than the normative.
Public-private partnership in the implementation of innovative urban development policy
Authors: Vertakova Yulia , Babich Tatyana , Lebedenko Olga
Published: December 2019

Many countries are moving to a new technological structure, caused by the 4th industrial and technological revolution. This transition is accompanied by the transformation of the previously existing territorial organization of the economy, infrastructure and resettlement, which relates to issues of urban development policy. In this case, coordination of the interests of the state and business is required. An effective tool in this area is public-private partnership (PPP). The main goal is the development of tools for the implementation of innovative urban development policy in the technological and social transformation of the economy. The methodological basis is the methodologies, approaches in the works of foreign and Russian scientists in the field of PPP research in the implementation of innovative urban policy. The main results of the study are following: 1.The modern task of urban development policy is the formation of a comfortable environment that will ensure a high standard of living for the population. 2. For the implementation of this task, the “adaptive territory” approach is suggested. 3. The modern tool for this approach is PPP. The main conclusions and recommendations can be used to justify the mechanisms for implementing innovative urban development policy in order to harmonize the interests of the state and business in the implementation of the “adaptive territory” approach, which meets the modern development paths of the global economy.
The use of concessions for overcoming crisis and pre-emergency condition of housing-and-communal facilities
Authors: Levoshich Natalia , Fatkullina Alina
Published: December 2019

The purpose of the article is to develop some recommendations on the improvement of housing-and-communal services financing on the basis of the mechanism of public-and-private partnership, and namely on the basis of concessionary agreements. The analysis of the housing-andmunicipal industry condition was carried out with the use of the municipal infrastructure development index. According to the analysis results, the that a considerable part of housing-and-communal facilities are in crisis or pre-emergency condition. It is fraught with technogenic accidents, damage to an environment, additional expenses on compensation of the environmental damage. Besides, the ecological costs of outdated and wornout facilities are high even without emergence of accidents. The conclusion was drawn that development, repair and replacement of worn-out objects of housing-and-communal infrastructure are necessary. In turn, additional financing of the sphere is necessary for this purpose. The experience of the concessionary agreements implementation in the Russian regions is considered. The conclusion is drawn that this experience positive in general, but the mechanism also has some shortcomings, some problems of the legislative regulation exist. Further distribution of concessions demands purposeful measures. The corresponding recommendations, developed by the author of the article, can be useful for regional and municipal authorities as well as for specialists of the companies, working in the field of housing-and-public services.
Landscape-town-planning reconstruction of the spatially-planning structure of destroyed cities (On the example of the cities of Baghdad and Mosul)
Authors: Sumayah Layij Jasim
Published: December 2019

The problem of restoring the spatial planning structure of the major cities of Iraq - Baghdad and Mosul, destroyed during the war of 2003-2011. Is currently relevant for ensuring their sustainable development and the formation of a comfortable, safe and environmentally-oriented urban environment. The study of the dynamics of the transformation of urban fabric of Baghdad and Mosul has a number of historical and methodological features related to specific socio-economic, cultural, historical and landscape-urban conditions that ensure their sustainable development in the future. An analysis of the dynamics of changes in the urban fabric of Baghdad and Mosul, which occurred as a result of military operations in these cities, made it possible to determine the priority areas of urban development, which in the future will ensure the formation of sustainable spatial planning structures of these cities. Proceeding from landscape, ecological and historical-architectural and urban development features of the cities of Baghdad and Mosul, the priority direction is landscape-urban reconstruction, based on the principles of landscape urbanism, which will restore and make accessible to residents and visitors of the city the lost historical and architectural objects, preserve identity historical and cultural environment through integration with the transport and green framework, linking the functional and planning zones of the city in a single “infrastructur” At present, such a strategy of urban transformation is used in the restoration of the historical cities of Iraq - Baghdad and Mosul.
Dangerous zone during transportation of dangerous goods
Authors: Medvedev Vladimir , Oshchepkov Zakhar , Bogomolova Ekaterina , Bogomolov Vladislav
Published: December 2019

The purpose of research is to develop elements of an integrated security system for zone of dangerous goods by federal railway transport with the possibility to employ them on international scale and in other modes of transport. Improving the concept of dangerous zone during transportation of dangerous goods stands in as the first-priority work stage of the development process. Solving the main tasks of the research was based on such proven and fruitful theoretical and experimental methods as computer modelling, comparative typology and circular expert estimations, statistical analysis, probability theory, theory of similarity, and others. The most meaningful results of the development are both of theoretical and practical importance. The theoretical result consists in development of a new approach to the concept of dangerous zone during transportation of dangerous goods by rail. The practical result involves development of proposals for improvement of the Railway Transport System of Emergency Prevention and Response; introduction of amendments into the Safety Rules for Response to Emergencies related to Dangerous Goods during Their Transportation by Rail; emergency cards for dangerous goods and a number of other technical guidance documents. Processing of the experimental data has established that the expected effectiveness of the development is 7.5–10%
Ensuring the competitiveness of innovation projects through the management of their life cycle parameters
Authors: Minaeva Elena , Yutkina Olga , Anoshina Yuliya , Maslyukova Ekaterina , Karapetyan Irina
Published: December 2019

The purpose of this paper is to develop guidelines for the assessment and implementation of innovation projects, which ensure its competitiveness through the management of life cycle parameters. The paper substantiates and generalizes the theoretical aspects of innovation project management, explores and systematizes the principles of developing a competitive innovation project. Based on the analyzed competitiveness factors, an integrated assessment indicator is proposed and an algorithm is formed that allows choosing the optimal set of risk management methods within the framework of an innovation project. In addition, modern methods for monitoring the competitiveness of innovation projects have been proposed, which allow determining the main areas of implementation and the level of research intensity of innovations.
Priority directions of development “Uzbekneftegas” jsc in the conditions of globalization of the world economy
Authors: Allaeva G.Zh.
Published: December 2019

The article considers the role of “Uzbekneftegas” JSC in the economic development of the fuel and energy complex of the Republic in the face of increasing global economic globalization. The structure of the company, the priority areas for the development of JSC activities are shown. The perspective directions in hydrocarbon production are considered. The data on the production, use and distribution of natural gas by sectors of the economy of Uzbekistan are presented, and the structure of the energy balance of the Republic of Uzbekistan is shown.
Search of the most important combinations of gas industry objects from the positions of system operability
Authors: Vorobev Sergey , Smirnova Elena
Published: December 2019

The article is devoted to the search and determination of the most important combinations of gas industry objects from the standpoint of system operability. The study was carried out on the example of the Unified Gas Supply System of Russia. The study is a development of the topic of the search and determination of critical objects of the system. Cases of simultaneous failure of two disconnected and independent from each other system objects are possible. The article presents a list of the most important combinations of gas industry objects that are not included in the list of critical objects, failure of which can lead to a significant gas shortage among consumers. Their significance and impact on the performance of the Russian gas industry are shown. Conclusions have been drawn on the feasibility of searching for such paired combinations of gas industry objects from the standpoint of system operability.
The investigation of frequency response analysis for power transformers winding condition
Authors: Nazarov Artyom , Savelev Vitaliy , Frogh Dennis
Published: December 2019

In modern electrical transmission and distribution systems, power transformers are critical components within the network. In the event that a failure occurs in service, the impact can be far reaching. The majority of mechanical deformation within power transformers is due to short circuit faults. The ageing transformer population increases the likelihood of failure so a reliable diagnostic tools required to determine the remaining life of these assets. Although, frequency response analysis (FRA) has been recently recognized as the most reliable detection tool for mechanical deformation in transformers, in the event of minor fault, the current FRA interpretation approach may not able to detect any variations between healthy and faulty FRA signatures. This paper focuses on FRA tests for power transformer and interpretation of obtained FRA signatures.
Method of calculation of system reliability on the basis of construction of the logical function of the system
Authors: Okhunov Dilshod , Okhunov Mamatjon , Akbarova Mukaddas
Published: December 2019

The article considers methods of calculating the reliability of systems using the logical functions of the system on the basis of the structural scheme of the system. And also the appliance of this method to calculate the probability of hacking the system based on the logical function of it.
About reliability characteristics of overhead electrical grids 6-10 kV elements
Authors: Abdurakhmanov Abdula , Glushkin Sergey , Shuntov Andrey
Published: December 2019

In the paper, failure outage statistics in 6–10 kV overhead electric grids of one of the largest electric grid companies in the European part of the country were analyzed to clarify the reliability characteristics of their elements. Failure intensity and mean restoration time for covered and uninsulated overhead lines, low-oil and vacuum circuit breaker cells, power transformers and secondary electrical grid elements were obtained. The obtained reliability characteristics of elements should be used in the tasks of technical justification and selection 6–10 kV overhead electrical grid preferred structure.
Increase the Reliability of Operation of Protection DC traction substation
Authors: Alekseev Leonid L. , Kolesnikov Anton A. , Papkov Boris V. , Osokin Sergey
Published: December 2019

For protection of direct current (DC) traction substation is proposed to use centralized differential protection. Estimation of reliability indicators is carried out on the basis of the method of Markov chains. The obtained results allow to make a conclusion about the prospects of implementing this protection.
Improving the reliability of combined overhead and cable power lines by organizing smart autoreclosing
Authors: Pelevin Pavel , Loskutov Anton , Sharafeev Timur
Published: December 2019

The application of combined overhead and cable power lines (OCPLs) of 110 kV voltage rate and higher call for new features for power system protection and automation devices. One of the most urgent is the problem of autoreclosing (AR) of OCPL. One or another solution to this problem significantly affects the reliability and efficiency of the OCPL operating. In many countries, both non-selective AR and selective AR are used. A method of selective AR of OCPL based on traveling waves is proposed, which increases the reliability of OCPL protection and automation. The method uses a special procedure of traveling wave pattern classification for faulted section identification.
Two approaches for automating analysis of electromagnetic processes in non-linear circuits with valves
Authors: Sapaev Khushnud , Umarov Shukhrat
Published: December 2019

This article analyses and compares two approaches related to automating modeling of valve electric circuits with piecewise linear approximation of valve characteristics. The first approach is based on operator equivalent circuits’ analytical formulas and on analytical expressions programming which describe equivalent circuits on each conduction interval of valve elements. The second approach provides implementation of a system for modeling valve converters based on implicit numerical integration formulas.
Artemisia abrotanum L., Eberraute
Authors: Melzig Matthias F.
Published: December 2019

Die Eberraute, Artemisia abrotanum L., ist eine seit dem Altertum bekannte Arzneipflanze, die traditionell bis ins 19. Jahrhundert bei Bronchial-, Lungen- und Darmkatarrhen genutzt wurde. In der Krautdroge sind neben ätherischem Öl v.a. Phenolsäuren, Cumarine, Flavonoide, Bitterstoffe sowie Peroxidhalbketale enthalten. Wegen des Thujongehaltes im ätherischen Öl einiger Herkünfte besitzt die Droge toxikologische Relevanz. Die pharmakologisch nur wenig untersuchte Arzneipflanze zeigt antimikrobielle, anthelminthische, repellente sowie immunmodulatorische Aktivität, die zur Behandlung der allergischen Rhinitis genutzt werden könnte. Ohne weitere klinische Studien kann die Anwendung der Droge nicht empfohlen werden.
Klostermedizin – Heilwissen aus der Antike bis heute
Authors: Mayer Johannes Gottfried
Published: December 2019

Europäische Klöster waren vom 8. bis zum 12. Jahrhundert wesentlich für die medizinische Versorgung. Antike Schriften dienten als Vorbild und prägten das heilkundliche Wissen. Die Klostermedizin umfasst dabei eine medizingeschichtliche Epoche, die auf die Regula Benedicti des Heiligen Benedikt zurückgeht. Die Klöster entwickelten sich zum Ort medizinischer Versorgung. Die zentralen heilkundlichen Ansätze der Klostermedizin waren die Humoralpathologie und die vier Primärqualitäten. Abhängig von den Primärqualitäten einer Erkrankung setzt man in der Klostermedizin Heilpflanzen mit jeweils gegenteiligen Qualitäten zur Behandlung ein.
Synthesis of Phenanthridinones by Palladium-Catalyzed Cyclization of N-Aryl-2-aminopyridines with 2-Iodobenzoic Acids in Water
Authors: Ding Xiaojuan , Zhang Lei , Mao Yiyang , Rong Binsen , Zhu Ning , Duan Jindian , Guo Kai
Published: December 2019

The first Pd-catalyzed cyclization of N-aryl-2-aminopyridines with 2-iodobenzoic acids for the synthesis of phenanthridinones through C–H bond activation under very low catalyst loadings (down to 0.1 mol% Pd) in water is reported. This protocol features a broad substrate scope and provides easy efficient access to various phenanthridinones.
Logical discrimination of multiple disease-markers in an ultra-compact nano-pillar lab-in-a-photonic-crystal
Authors: Al-Rashid Abdullah , John Sajeev
Published: December 2019

We present a theoretical prescription for a physically realizable Lab-in-a-Photonic-Crystal optical biosensor that can instantaneously detect and discriminate multiple analytes, both quantitatively and combinatorially, in a single spectroscopic measurement. Unlike other biosensors that utilize simple resonance modes, our fundamental operating principle is the analyte-induced hybridization of waveguide modes and surface modes in a photonic bandgap, leading to a complex spectral fingerprint. Our real-world liquid-infiltrated photonic crystal sensor supplants two-dimensional conceptual paradigms proposed earlier with realistic features and a path to implementation. A square-lattice photonic crystal of nanopillars with fixed height but differentiated cross sections within a narrow flow-channel is used for cascaded transmission of light through the photonic bandgap. The nanopillar array is placed on a thin layer of high-refractive-index backing material resting on a glass substrate with fluid and biomarker flow along the waveguide direction. Using finite-difference time-domain simulations of light transmission perpendicular to the waveguide, a variety of spectral fingerprints are identified as various disease-marker combinations bind to specific lines of nanopillars. Various diseases or various stages of a given disease are detected and differentiated through the interplay of central-waveguide resonances with edge modes and three-dimensional index-guided bulk modes. This offers a distinctive mechanism for instantaneous disease diagnosis using a minimal volume of fluid sample.
An adaptive stair-ascending gait generation approach based on depth camera for lower limb exoskeleton
Authors: Zhao Xiaoming , Chen Wei-Hai , Li Bing , Wu Xingming , Wang Jianhua
Published: December 2019

The mobility on stairways is a daily challenge for seniors and people with dyskinesia. Lower limb exoskeletons can be effective assistants to improve their life quality. In this paper, we present an adaptive stair-ascending gait generation algorithm based on a depth camera for lower limb exoskeletons. We first construct a linked-list-based stairway model with the point cloud captured from the depth camera. Then, an optimal foothold point is calculated based on the linked-list stair model for gait generation. Finally, the exoskeleton takes the stair-ascending gait of healthy people as a reference and generates appropriate gait for the stair. The proposed gait generation algorithm is initially validated through holistic simulation analyses. We tested the stairway modeling algorithm on varieties of indoor and outdoor stairways and evaluated the gait generation algorithm on stairs of different height. The subjects’ stair walking tests with lower limb exoskeletons show the effectiveness of the proposed stairway modeling and gait generation approaches.
Development of a dual infrared and visible near-infrared measurement system for the observation of adiabatic shear bands
Authors: Pawelko R. , Pina V. , Hervé P.
Published: December 2019

This paper presents the development of a new system designed to measure the local temperature field in adiabatic shear bands. Transient temperature fields are simultaneously recorded by using an array of 32 InSb infrared (IR) detectors and a streak camera working in visible-near infrared (VIS-NIR). Observations in IR offer a low temperature detection limit (550 K), but they are highly sensitive to uncertainties in emissivity. Observations in VIS-NIR allow for measurements only at high temperatures (>1000 K), but they are less affected by uncertainties in emissivity and present a higher temperature sensitivity. By performing simultaneous measurements, it is possible to obtain data in a large temperature range with an improved accuracy at high temperature. The different sources of error caused by uncertainties in emissivity, spatial resolution, and temporal resolution have been analyzed, and an estimation of the total measurement uncertainties of the system is given.
The ion kinetics at the wafer edge by the variation of geometry and permittivity of the focus ring in capacitively coupled discharges
Authors: Kim Jin Seok , Hur Min Young , Kim Ho Jun , Lee Hae June
Published: December 2019

The change of the ion transport is investigated with the variation of the focus ring property at the wafer edge of a capacitively coupled plasma under an intermediate pressure of a few Torr. The particle fluxes and the ion trajectories at different locations are investigated with the variations of the gap size between the wafer edge and the focus ring, the focus ring height, and the permittivity of the focus ring. The incident angle and the particle fluxes to the wafer edge increase with the gap size. Conversely, the particle fluxes to the wafer edge decrease with the increase in the focus ring height. The incident angle of ions still keeps normal to the surface at the wafer edge, but on the left side of the focus ring, it increases dramatically with the increase in the focus ring height. With the change of the permittivity of the focus ring, it is possible to control the ratio of the ion flux to the neutral flux on the focus ring surface by enhancing only the ion flux independently.
Aging transition in the absence of inactive oscillators
Authors: Sathiyadevi K. , Gowthaman I. , Senthilkumar D. V. , Chandrasekar V. K.
Published: December 2019

The role of counter-rotating oscillators in an ensemble of coexisting co- and counter-rotating oscillators is examined by increasing the proportion of the latter. The phenomenon of aging transition was identified at a critical value of the ratio of the counter-rotating oscillators, which was otherwise realized only by increasing the number of inactive oscillators to a large extent. The effect of the mean-field feedback strength in the symmetry preserving coupling is also explored. The parameter space of aging transition was increased abruptly even for a feeble decrease in the feedback strength, and, subsequently, aging transition was observed at a critical value of the feedback strength surprisingly without any counter-rotating oscillators. Further, the study was extended to symmetry breaking coupling using conjugate variables, and it was observed that the symmetry breaking coupling can facilitate the onset of aging transition even in the absence of counter-rotating oscillators and for the unit value of the feedback strength. In general, the parameter space of aging transition was found to increase by increasing the frequency of oscillators and by increasing the proportion of the counter-rotating oscillators in both symmetry preserving and symmetry breaking couplings. Further, the transition from oscillatory to aging occurs via a Hopf bifurcation, while the transition from aging to oscillation death state emerges via the pitchfork bifurcation. Analytical expressions for the critical ratio of the counter-rotating oscillators are deduced to find the stable boundaries of the aging transition.
Deconstructing electrode pore network to learn transport distortion
Authors: Mistry Aashutosh , Mukherjee Partha P.
Published: December 2019

The central premise of porous electrodes is to make more surface area available for reactions. However, the convoluted pore network of such reactors exacerbates the transport of reacting species. Tortuosity is a measure of such transport distortion and is conventionally expressed in terms of porosity (the fraction of electrode volume occupied by liquid-filled pores). Such an approach is overly simplistic and falls short of accounting for spatial variabilities characteristic of electrode samples. These networks are defined by multiple features such as size distribution, connectivity, and pore morphology, none of which are explicitly considered in a porosity based interpretation, thus limiting predictability. We propose a recourse using a two-point correlation function that deconstructs the pore network into its essential attributes. Such a quantitative representation is mapped to the transport response of these networks. Given the explicit treatment of pore network geometry, this approach provides a consistent treatment of three-dimensionalities such as inhomogeneity and anisotropy. Three-dimensional (3D) tomograms of Li-ion battery electrodes are studied to characterize the efficacy of the proposed approach. The proposed approach is applicable to abstracting effective properties related to different transport modes in porous fluid networks.
Physics behind laser thermogenetic neurostimulation
Authors: Lanin A. A. , Belousov V. V. , Zheltikov A. M.
Published: December 2019

We present a physical model of laser thermogenetic neurostimulation, which combines radiation- and heat-transfer analysis with thermodynamic treatment of thermosensitive cell-membrane ion channels and the electrophysical description of the neuron response to the thermal gating of ion channels. Based on the analysis performed within the framework of this model, we identify the parameter space within which laser thermogenetic neurostimulation can be confined to a single neuron and show that an accurately dosed nonstationary heat transfer set off by near-infrared laser pulses with a laser wavelength chosen within the transparency window of water, centered at ≈1670 nm, can help extend single-cell thermogenetic neurostimulation to deep brain regions.
Subsonic choking in microchannel slip flow: Isothermal or adiabatic?
Authors: Garg Richie , Agrawal Amit
Published: December 2019

Some experimental evidence of subsonic choking in rarefied gas flow regime is available; however, the nature of the flow (isothermal/adiabatic) close to the choking point is not known. The theoretical limiting Mach number (Ma) for isothermal choked flows is 1/γ (where γ is the ratio of specific heat) and that for adiabatic choked flows is unity. In this work, we perform measurements for temperature, pressure, and mass flow rate at the inlet and outlet of a microchannel of aspect ratio 0.49 in the slip flow regime (4.04 × 10−3 < Kno < 7.04 × 10−3, where Kno is the outlet Knudsen number). We see some evidence of choking at Ma close to 1/γ with a shift in the choking point to Ma of unity. The measured static temperature is observed to be constant at microchannel inlet and outlet, indicating isothermal flow behavior for lower Ma values. The stagnation temperature is calculated to be nearly constant at the microchannel outlet for higher Ma values, indicating a shift in flow behavior to adiabatic. This study emphasizes the significance of temperature measurement for understanding the choking behavior. There is no active transfer of heat during the experiments, making the present work relevant to practical and real situations. This state-of-the-art study would be immensely useful while designing microchannels and microtubes for long-distance gas transportation, microelectromechanical systems, and space applications, where one needs to be careful about any occurrence of choking.
Modeling of parasitic oscillations in smooth-wall circular symmetric dielectric-loaded gyrotron beam ducts
Authors: Genoud J. , Alberti S. , Hogge J.-Ph. , Tigelis I. G. , Latsas G. P. , Chelis I. G.
Published: December 2019

The self-consistent simulation of the electron beam interaction was performed in the presence of a lossy dielectric layer in the smooth-wall beam duct of a gyrotron oscillator. For this purpose, the linear and spectral code TWANGlinspec was extended. In this code, the local transverse structure of the TE mode is adapted to the solution of the complex cold dispersion relation of an infinite, homogeneous, dielectric coated cylindrical waveguide. Before considering the realistic situation, the validity of the TE pure mode (Ez = 0) assumed in TWANGlinspec had to be assessed for SiC or BeOSiC materials. The effect of the dielectric layer on the parasitic starting current is large for parasitic oscillations localized at the end of the beam duct and in the so-called spacer region. For the realistic case, the geometry of the dual frequency gyrotron for the Tokamak à Configuration Variable was considered, and the effect of a dielectric layer was numerically investigated. The electron beam velocity spread was also included in the simulations. The result is that in such conditions, the parasitic oscillation starting currents are increased above the operating beam current. The observation of these spurious modes would therefore not be expected.
Optoelectronic response of hybrid PbS-QD/graphene photodetectors
Authors: Ahn Seungbae , Chung Hyeseung , Chen Wenjun , Moreno-Gonzalez Miguel A. , Vazquez-Mena Oscar
Published: December 2019

Lead sulfide quantum dots (QDs) have been widely used for various optoelectronic devices due to their high absorption coefficient and tunable bandgap. However, the low mobility of QD films results in poor charge collection and device performance. By combining QDs with graphene into hybrid graphene/QD photodetectors, photocarriers from QDs are transferred to graphene, improving charge collection and transport, drastically increasing the photoresponsivity. Herein, we carry a systematic analysis on how critical tuning parameters such as QD size and QD film thickness affect responsivity, spectral response, and time response. We report the absorption coefficient, refractive index (n, k), penetration depth, and energy bandgap of PbS QDs of different sizes. We study systematically how the photocurrent, photoresponsivity, time response, and power density dependence vary with QD size in hybrid Gr/QD. The bandgap of lead sulfide quantum dots was size-tuned between 0.86 and 1.39 eV. The time response shows that subsecond modulation can be achieved for different QD sizes with a responsivity up to 107 A/W at power densities of 10−5 mW/cm2. We also studied how the performance of the photodetectors is affected by the thickness, discussing the limitations on the thickness by the compromise between light absorption and charge collection. We describe how the optical response shifts toward the infrared as QD films get thicker. Time responses below 1 s are obtained for graphene/QD devices with thickness from 150 nm to 1 μm. This systematic study provides important guidelines to design hybrid graphene/QD photodetectors and tune their spectral response and performance.
Convolutional neural network enhancement of fast-scan low-dose cone-beam CT images for head and neck radiotherapy
Authors: Yuan Nimu , Dyer Brandon , Rao Shyam , Chen Quan , Benedict Stanley , Shang Lu , Kang Yan , Qi Jinyi , Rong Yi
Published: December 2019

To improve image quality and CT number accuracy of fast-scan low-dose cone-beam computed tomography (CBCT) through a deep-learning convolutional neural network (CNN) methodology for head-and-neck (HN) radiotherapy.

Fifty-five paired CBCT and CT images from HN patients were retrospectively analysed. Among them, 15 patients underwent adaptive replanning during treatment, thus had same-day CT/CBCT pairs. The remaining 40 patients (post-operative) had paired planning CT and 1st fraction CBCT images with minimal anatomic changes. A 2D U-Net architecture with 27-layers in 5 depths was built for the CNN. CNN training was performed using data from 40 post-operative HN patients with 2080 paired CT/CBCT slices. Validation and test datasets include 5 same-day datasets with 260 slice pairs and 10 same-day datasets with 520 slice pairs, respectively. To examine the impact of differences in training dataset selection and network performance as a function of training data size, additional networks were trained using 30, 40 and 50 datasets. Image quality of enhanced CBCT images were quantitatively compared against the CT image using mean absolute error (MAE) of Hounsfield units (HU), signal-to-noise ratio (SNR) and structural similarity (SSIM).

Enhanced CBCT images reduced artifact distortion and improved soft tissue contrast. Networks trained with 40 datasets had imaging performance comparable to those trained with 50 datasets and outperformed those trained with 30 datasets. Comparison of CBCT and enhanced CBCT images demonstrated improvement in average MAE from 172.73 to 49.28 HU, SNR from 8.27 to 14.25 dB, and SSIM from 0.42 to 0.85. The image processing time is 2 s per patient using a NVIDIA GeForce GTX 1080 Ti GPU.

The proposed deep-leaning methodology was fast and effective for image quality enhancement of fast-scan low-dose CBCT. This method has potential to support fast online-adaptive re-planning for HN cancer patients.
Microstructural and ageing response assessment of eutectic Al-Cu alloy due to isothermal heat treatment in semisolid state
Authors: Chaudhari Abhimanyu , Nasker Purnendu , Srivastava Ankur , Paul Sudeep , Chakrabarti Ajit Kumar
Published: December 2019

An as cast Al-33%Cu eutectic alloy has been processed by semisolid heat treatment, with the ultimate objective of developing a ductile and strong eutectic composite material for probable application as bearing materials and other sliding wear components. In this phase of work only microstructural characterises has been attempted. The as cast sample of Al–Cu alloy is subjected to isothermal heat treatment at a temperature of 560 °C for varying periods of time and followed by water quenched. The microstructures of the semisolid heat treated (SSH) samples are analysed using an optical microscope and scanning electron microscopy (SEM). The microstructures of the quenched Al-33%Cu alloy samples show lamellar to lamellar + dendritic transition after SSH treatment. The quenched microstructure after 20 min of holding time primarily consists of copper aluminide dendrites + supersaturated α–Al grains. A massive copper-aluminide (>80%Cu) intermediate phase is observed after 3 to 6 min SSH. The sample configuration did not change after semisolid heat treatment and water quenching. This suggest that complete remelting and overburning did not occur during the semisolid heat treatment. The SSH sample shows maximum hardness, after 10 min holding time compared to solution treated (at 560 °C) and aged (at 150 °C) sample of a standard Al-4.5%Cu cast alloy. The Transmission electron microscopy (TEM) micrograph of the as quenched 10 min. SSH sample shows rod shaped CuAl2 (θ) precipitates, a dislocation network, cellular subgrains and an extremely fine lamellar eutectic. Solute cluster probably Guinier–Preston (GP) zones, precipitates and fine α –Al grains was observed in the peak aged sample. The x-ray diffraction (XRD) analysis of aged SSH treated sample shows several intermetallic copper-aluminide phases in each sample.
Aphids in focus: unravelling their complex ecology and evolution using genetic and molecular approaches
Authors: Loxdale Hugh D , Balog Adalbert , Biron David G
Published: December 2019

Aphids are renowned plant parasites of agriculture, horticulture and forestry, causing direct physical damage by sucking phloem and especially by transmission of plant pathogenic viruses. The huge yield loss they cause amounts to hundreds of millions of dollars globally, and because of this damage and the intense efforts expended on control, some 20 species are now resistant to pesticides worldwide. Aphids represent an ancient, mainly northern temperate group, although some species occur in the tropics, often as obligate asexual lineages or even asexual ‘species’. However, besides their notoriety as enemies of plant growers, aphids are also extremely interesting scientifically, especially at the molecular and genetic levels. They reproduce mainly asexually, one female producing 10–90 offspring in 7–10 days and therefore, theoretically, could produce billions of offspring in one growing season in the absence of mortality factors (i.e. climate/weather and antagonists). In this overview, we provide examples of what molecular and genetic studies of aphids have revealed concerning a range of topics, especially fine-grained ecological processes. Aphids, despite their apparently limited behavioural repertoire, are in fact masters (or, perhaps more accurately, mistresses) of adaptation and evolutionary flexibility and continue to flourish in a variety of ecosystems, including the agro-ecosystem, regardless of our best efforts to combat them.