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2020

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Articles 541 - 570 of 1829

Full-Text Articles in Civil and Environmental Engineering

Thermodynamic Cement Hydration Modelling Using Hydcem, Niall Holmes, Denis Kelliher, Mark Tyrer Aug 2020

Thermodynamic Cement Hydration Modelling Using Hydcem, Niall Holmes, Denis Kelliher, Mark Tyrer

Conference papers

Thermodynamics have been successfully applied to the field of cement hydration science to predict the formation of phase assemblages and pore solution chemistry. For any cement hydration model to be accepted, it must provide accurate forecasts of which solids may form and how the cement will dissolve over time. This is particularly important for the ongoing development of new sustainable cements and understanding their hydration behaviour in service. HYDCEM is a cement hydration model that simulates volumetric changes of cement and gypsum dissolution and product growth that, up to now, assumed which solids would form. In order to improve its …

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Effects Of Accelerated Carbonation Curing On Co2 Sequestration And On The Compressive Strength Of Concrete Masonry Units, Barry Gilroy, Leon Black, David Thompson, Ronan Hogan, Niall Holmes Aug 2020

Effects Of Accelerated Carbonation Curing On Co2 Sequestration And On The Compressive Strength Of Concrete Masonry Units, Barry Gilroy, Leon Black, David Thompson, Ronan Hogan, Niall Holmes

Conference papers

The global consumption of Portland cement has risen to over 4 billion tonnes per annum. Its manufacture is energy and carbon intensive and approximately 900 kg of CO2 is emitted into the atmosphere for each tonne of Portland cement produced. The International Energy Agency (IEA) roadmap sets out a goal to reduce emissions due to cement production to 18 % below 2006 levels by 2050. Concrete has the potential to re-absorb CO2 by the process of carbonation, where it reacts with CaO in the concrete to form calcium carbonate. Accelerated carbonation curing (ACC) is a technique for curing fresh concrete …

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The Use Of Three-Dimensional Conjugate Cfd To Enhance Understanding Of, And To Verify, Multi-Modal Heat Transfer In Dynamic Laboratory Test Walls, Rakshit D. Muddu, Timothy Patrick O'Leary, Ronan Hogan, Anthony James Robinson, Aimee Byrne Aug 2020

The Use Of Three-Dimensional Conjugate Cfd To Enhance Understanding Of, And To Verify, Multi-Modal Heat Transfer In Dynamic Laboratory Test Walls, Rakshit D. Muddu, Timothy Patrick O'Leary, Ronan Hogan, Anthony James Robinson, Aimee Byrne

Articles

This work describes the use of conjugate computational fluid dynamics (C-CFD) to simulate controlled laboratory based dynamic heat transfer tests on building components. This study proposes that conjugate CFD simulation can be used to evaluate the influence of combined convective and conductive heat transfer in multi-state building components. To this end, a solid wall and cavity wall were tested with a Calibrated Hotbox and subject to variable temperature conditions leading to combined convective and conductive heat transfer. The varying temperature of the heat source was monitored and used as the input boundary condition in the simulation model, which included a …

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Predicting Mortar Compressive Strength Using Hydcem, Ewoma Ogoro, Niall Holmes, Denis Kelliher, Mark Tyrer Aug 2020

Predicting Mortar Compressive Strength Using Hydcem, Ewoma Ogoro, Niall Holmes, Denis Kelliher, Mark Tyrer

Conference papers

The compressive strength of mortar is a significant property that will influence its performance in concrete or masonry. Being able to accurately model and predict the mortar compressive strength would be of great benefit to suppliers and end users alike that could possibly reduce the need for multiple physical testing. A section of the original HYDCEM cement hydration model (amoungst others) has been partitioned to focus on predicting the compressive strength of Portland cement and cement-limestone mortars, entitled HYDCEM_CompressiveStrength. The model uses the cement/binder oxide composition along with other inputs to predict the compressive strength development over time. This paper …

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Characterization And Performance Of Cement-Based Thermoelectric Materials, Ruchita Jani, Niall Holmes, Roger P. West, Kevin Gaughan, Xiaoli Liu, Esther Orisakwee, Conrad Johnston, Ming Qu, Jorge Kohanoff, Lorenzo Stella, Hongxi Yin Aug 2020

Characterization And Performance Of Cement-Based Thermoelectric Materials, Ruchita Jani, Niall Holmes, Roger P. West, Kevin Gaughan, Xiaoli Liu, Esther Orisakwee, Conrad Johnston, Ming Qu, Jorge Kohanoff, Lorenzo Stella, Hongxi Yin

Conference papers

Thermoelectric materials enable direct conversion of thermal energy to electricity. Ambient heat energy harvesting could be an effective route to convert buildings from being energy consumers to energy harvesters, thus making them more sustainable. There exists a relatively stable temperature gradient (storing energy) between the internal and external walls of buildings which can be utilized to generate meaningful energy (that is, electricity) using the thermoelectric principle. This could ultimately help reduce the surface temperatures and energy consumption of buildings, especially in urban areas. In this paper, ongoing work on developing and characterizing a cement-based thermoelectric material is presented. Samples are …

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Conceptual Study Of A Real-Time Hybrid Simulation Framework For Monopile Offshore Wind Turbines Under Wind And Wave Loads, Wei Song, Chao Sun, Yanhui Zuo, Vahid Jahangiri, Yan Lu, Qinghua Han Aug 2020

Conceptual Study Of A Real-Time Hybrid Simulation Framework For Monopile Offshore Wind Turbines Under Wind And Wave Loads, Wei Song, Chao Sun, Yanhui Zuo, Vahid Jahangiri, Yan Lu, Qinghua Han

Faculty Publications

As an attractive renewable energy source, offshore wind plants are becoming increasingly popular for energy production. However, the performance assessment of offshore wind turbine (OWT) structure is a challenging task due to the combined wind-wave loading and difficulties in reproducing such loading conditions in laboratory. Real-time hybrid simulation (RTHS), combining physical testing and numerical simulation in real-time, offers a new venue to study the structural behavior of OWTs. It overcomes the scaling incompatibilities in OWT scaled model testing by replacing the rotor components with an actuation system, driven by an aerodynamic simulation tool running in real-time. In this study, a …

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Rapid Visual Presentation To Support Geospatial Big Data Processing, E. Levin, W. Roland, R. Habibi, Z. An, R. Shults Aug 2020

Rapid Visual Presentation To Support Geospatial Big Data Processing, E. Levin, W. Roland, R. Habibi, Z. An, R. Shults

Michigan Tech Publications, Part 1

Given the limited number of human GIS/image analysts at any organization, use of their time and organizational resources is important, especially in light of Big Data application scenarios when organizations may be overwhelmed with vast amounts of geospatial data. The current manuscript is devoted to the description of experimental research outlining the concept of Human-Computer Symbiosis where computers perform tasks, such as classification on a large image dataset, and, in sequence, humans perform analysis with Brain-Computer Interfaces (BCIs) to classify those images that machine learning had difficulty with. The addition of the BCI analysis is to utilize the brain's ability …

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On The Localized Settlement Of Geodetic Networks And Points For The Monitoring Of The Migration Of Landslides, B.R. Nazarov, H.T. Kayumova, R.X. Mukarramov Aug 2020

On The Localized Settlement Of Geodetic Networks And Points For The Monitoring Of The Migration Of Landslides, B.R. Nazarov, H.T. Kayumova, R.X. Mukarramov

Journal of Tashkent Institute of Railway Engineers

The article is devoted to the formation of on-site geodetic network points to prevent geological processes such as landslides or large deformations, and provides methodology for establishing network points to continuously monitor the movement of avalanche sites. In addition, the methodology for the creation of geodetic network points at impassable distances are described.

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Research Of Porosity Of A Cement Stone With A Zeolite Containing Filler And A Superplasticstificator, Anvar Ishanovich Adilhodzhaev, I.A. Kadyrov, K.S. Umarov Aug 2020

Research Of Porosity Of A Cement Stone With A Zeolite Containing Filler And A Superplasticstificator, Anvar Ishanovich Adilhodzhaev, I.A. Kadyrov, K.S. Umarov

Journal of Tashkent Institute of Railway Engineers

The question of the influence of the zeolite-containing filler of the Beltau deposit and the polycarboxylate superplasticizer on the formation of porosity of cement stone is considered. The results of experiments to establish the effect of a zeolite-containing filler and a plasticizing additive on pore size distribution are graphically presented. The data obtained confirm the advisability of using this type of filler in concrete.

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Features Of Laboratory Testing Methods Of Clayey Soils, A. Zhussupbekov, A. Tulebekova, U. Abduraimov Aug 2020

Features Of Laboratory Testing Methods Of Clayey Soils, A. Zhussupbekov, A. Tulebekova, U. Abduraimov

Journal of Tashkent Institute of Railway Engineers

The article compares the results of laboratory tests of dispersed soils to determine their strength characteristics. For this purpose, soils were tested on devices with three-axis compression and single-plane cut. In calculations for clay and sandy soils, indicators of their strength properties are used, which include such characteristics as the angle of internal friction φ and specific adhesion c. Based on the results of this work, recommendations on the practical application of the obtained soil characteristics for the geo-information geotechnical database of Astana were compiled.

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Mathematical Modeling Of The Carriage Movement Along The Descending Part To Movement Of The Marshalling Hump, Kh.T Turanov, Sh.U. Saidivaliev, Sh.B. Djabbаrov, Kh.Kh. Djalilov Aug 2020

Mathematical Modeling Of The Carriage Movement Along The Descending Part To Movement Of The Marshalling Hump, Kh.T Turanov, Sh.U. Saidivaliev, Sh.B. Djabbаrov, Kh.Kh. Djalilov

Journal of Tashkent Institute of Railway Engineers

In the article, based on the basic law of point dynamics with non-ideal connection of theoretical mechanics, the speed of the car movement on each section of the descending part of the marshalling hump. A generalized model of the speed of the car at the calculated point of the marshalling hump is obtained. This model made it possible to calculate the instantaneous values of the speed of the car from the top of the hill to the calculated point in a continuous mode. This made it possible to speed up the process of plotting changes in accelerations, speeds, and time …

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On Design Features And Improvements Freight Wagon Braking Systems, U.Sh. Israilov Aug 2020

On Design Features And Improvements Freight Wagon Braking Systems, U.Sh. Israilov

Journal of Tashkent Institute of Railway Engineers

The review of the basic schemes of brake lever transmissions used on freight wagons of Uzbekistan is presented. The advantages and disadvantages inherent to these schemes are shown. Methods of brake systems improvement are considered and the analysis of theoretical methods of their design evaluation is made.

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Equipment For Transportation Of Wooden Materials: New Technological Solutions And The Use Of High Strong Steels, N.A. Tanicheva, I.O. Filippova, R.V. Rahimov, Ya.O. Ruzmetov Aug 2020

Equipment For Transportation Of Wooden Materials: New Technological Solutions And The Use Of High Strong Steels, N.A. Tanicheva, I.O. Filippova, R.V. Rahimov, Ya.O. Ruzmetov

Journal of Tashkent Institute of Railway Engineers

There is a need to develop a new design of removable reusable means for the transportation of timber on universal wagon platforms, including using high-strength steel. The use of high-strength steel improves the technical and economic performance of platform wagons for the transportation of timber. The need to develop the regulatory and technical base for the introduction of new high-strength steels in the wagon industry has been identified.

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Forecast Efficiency Of Application Of Electronic Documents In Cargo And Commercial Works On Railway Transport, N.M. Aripov, Sh.Sh. Kamaletdinov Aug 2020

Forecast Efficiency Of Application Of Electronic Documents In Cargo And Commercial Works On Railway Transport, N.M. Aripov, Sh.Sh. Kamaletdinov

Journal of Tashkent Institute of Railway Engineers

This article provides a predictive economic assessment of the introduction of electronic document management technology based on an electronic digital signature on the processes of freight and commercial work in rail transport. To determine the economic efficiency of the proposed technology, a technique was used that includes countable and uncountable effects. The constituent elements, the main economic indicators of the implementation of the automated system are detailed. Savings of money and time of railway transport and users of freight transportation services are determined.

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Increasing The Train Safety Level Based On A Process Approach, A.Kh. Makhkamov, M.Sh. Valiev Aug 2020

Increasing The Train Safety Level Based On A Process Approach, A.Kh. Makhkamov, M.Sh. Valiev

Journal of Tashkent Institute of Railway Engineers

The article deals with improving the level of train traffic safety based on the process approach, provides a classification of failures of technical means and methods of their parry. The main attention is paid to the occurrence of cases of traffic safety violations. To increase the level of the DB support system, the entire process of organizing transportation is divided into four main blocks: management processes, resource support processes, production processes, interaction and control processes.

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Modernization Of The Crate Suspension Unit Of The Vl-80s Electric Carrier, G.А. Khromova, D.O. Radjibaev, S.A. Khromov, I.C. Kamalov Aug 2020

Modernization Of The Crate Suspension Unit Of The Vl-80s Electric Carrier, G.А. Khromova, D.O. Radjibaev, S.A. Khromov, I.C. Kamalov

Journal of Tashkent Institute of Railway Engineers

The article presents the development of a modernized design of a cradle suspension unit for an electric locomotive VL-80s with improved elastic-dissipative suspension properties with substantiation of dynamic and strength parameters. Numerical studies were carried out in the MathCAD 15 programming environment. For railway company is necessary to develop a new method of modernizing the cradle suspension of the VL-80s electric locomotive during overhaul repairs in order to improve the dynamic characteristics and increase the strength and reliability.

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Research Of Development Prospects Of Transportation Hub In Jsc "Umc", Marufdjan Xalikovich Rasulov, Sh.M. Suyunbayev, M.N. Masharipov Aug 2020

Research Of Development Prospects Of Transportation Hub In Jsc "Umc", Marufdjan Xalikovich Rasulov, Sh.M. Suyunbayev, M.N. Masharipov

Journal of Tashkent Institute of Railway Engineers

As you know, an increase in the volume of production of any object requires to reasonably provide for a comprehensive analysis of the compliance of its technical equipment and technology of work with the prospective traffic volumes. The article analyzes the existing and prospective volumes of work, shows the results of calculations, the available throughput capacity of the station. "B" - Art. "З" and the throughput of the receiving and departure tracks stations "Z", "P" and “S ", the required number of shunting locomotives has been determined, a number of measures have been proposed to improve the work of the …

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Application Of Fiber-Optic Communication Line Under Control And Monitoring Of Track Relays In Station Rail Circuits, Q.K Nuriddinov, Z.I. Mamedova Aug 2020

Application Of Fiber-Optic Communication Line Under Control And Monitoring Of Track Relays In Station Rail Circuits, Q.K Nuriddinov, Z.I. Mamedova

Journal of Tashkent Institute of Railway Engineers

This article discusses the problems of using a fiber-optic transmission line under control and monitoring the voltage of track relays in station rail circuits. A functional diagram of the fast and central equipment of a fiber-optic transmission line and their interconnection are shown. Several different network modules for organizing data transfer are considered. Comparative analyzes are given, problems that arise during the operation of network modules and their solutions are described. As a result of the analysis, the optimal version of the network module was selected and recommendations for developing its software are given

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Transfer Function Of A Traction Induction Motor Controlled By A Four-Quadrant Converter, As A Link Functional Diagnostics, M.C. Yakubov, Zh.S. Fayzullaev Aug 2020

Transfer Function Of A Traction Induction Motor Controlled By A Four-Quadrant Converter, As A Link Functional Diagnostics, M.C. Yakubov, Zh.S. Fayzullaev

Journal of Tashkent Institute of Railway Engineers

An expression for the transfer function of a traction asynchronous motor with a four-square converter is derived. It is shown that the basic properties of the traction motor, which are a four-square converter, correspond to the linearization coefficients. The values of linearization coefficients for a typical system in the entire region of equilibrium states.

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Dynamic Characteristics Of The New Three-Phase Current Unbalance Transformer Converter, Sultan Fayzullayevich Amirov, S.X. Zhumaboyev, N.R. Yuldashev Aug 2020

Dynamic Characteristics Of The New Three-Phase Current Unbalance Transformer Converter, Sultan Fayzullayevich Amirov, S.X. Zhumaboyev, N.R. Yuldashev

Journal of Tashkent Institute of Railway Engineers

The article examines the dynamic characteristics of a new transformer Converter for three-phase current asymmetry. It is shown that when a three-phase current is applied to the input of the Converter, its transient characteristic consists of the sum of the established sinusoidal and free components, which decay at a speed that depends on the time constant of the magnetic circuit of the Converter.

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Automatic Locomotive Signaling Parameters Devices On The Basis Of Microprocessor Elements, B.B Raxmonov, J.F. Kurbanov, J.E. Xidirov Aug 2020

Automatic Locomotive Signaling Parameters Devices On The Basis Of Microprocessor Elements, B.B Raxmonov, J.F. Kurbanov, J.E. Xidirov

Journal of Tashkent Institute of Railway Engineers

This article is devoted to an automatic locomotive signaling device associated with railway automation and telemechanics systems, ensuring the safety of train traffic. Wearable devices designed to test locomotive alarms are presented. Methods of measuring the magnetic field of the rails are described. A microprocessor-based digital decoder was developed for the special communication laboratory carriage. To improve the accuracy of the device, software and a wireless module were developed for storing the obtained measurement results and sending data online to the station's electromechanics. In the process, the following parameters are comprehensively determined: differential EMF, active resistance, quality factor and insulation …

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Substantiation Of The Input Of The Parameters Of The Unprofitable Loss Of Time When Norming The Time Of The Duration Of The Wagons On The Sorting Station, D.B. Butunov Aug 2020

Substantiation Of The Input Of The Parameters Of The Unprofitable Loss Of Time When Norming The Time Of The Duration Of The Wagons On The Sorting Station, D.B. Butunov

Journal of Tashkent Institute of Railway Engineers

Defining a new approach to accounting, analysis and reduction of unproductive losses in the operation of the sorting station. The methods of factor analysis are applied, the construction of a map of value creation flows. An expression is given for determining the values of unproductive losses in the operation of the station. The number of the causes of losses is determined, and they are grouped in order to solve the problem of overcoming the information gap in the analysis of the causes of losses. A flow map of the existing and proposed state of the carriage processing process at the …

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Development Of Algorithms And Methods Of Automatic Mode Of Electric Centralization System For Installing Routes For High-Speed Trains, B.B. Raxmonov, S.T. Boltaev, J.F. Kurbanov Aug 2020

Development Of Algorithms And Methods Of Automatic Mode Of Electric Centralization System For Installing Routes For High-Speed Trains, B.B. Raxmonov, S.T. Boltaev, J.F. Kurbanov

Journal of Tashkent Institute of Railway Engineers

At present, the CIS (Commonwealth of Independent States) has introduced an additional “high-speed traffic” regime in the electrical interlocking system to prepare routes for high-speed trains at stations. The use of a scheduled time notification restricts the movement of trains at stations and paralyzes all movements at stations and tracks before and after the passage of a high-speed train. To reduce this time, algorithms and methods were proposed for the automatic mode of the electrical interlocking system when establishing routes to stations, taking into account various categories of trains.

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Determining The Correction Factor For A Current Transformer With Automatic Range Control, Sultan Fayzullayevich Amirov, Sh.S. Mukhsimov, O.T. Boltayev, S.Kh. Zhumaboyev Aug 2020

Determining The Correction Factor For A Current Transformer With Automatic Range Control, Sultan Fayzullayevich Amirov, Sh.S. Mukhsimov, O.T. Boltayev, S.Kh. Zhumaboyev

Journal of Tashkent Institute of Railway Engineers

The article deals with the introduction of a correction factor for protection and control devices, since the value of the secondary current in one range does not correspond to the value of the secondary current in the other range, which is determined depending on the difference of the counter-directional MDS created by the components of the inter-counter-directional primary current of the current transformer. Also, an algorithm was developed to account for the measurement error in the automatic system that controls the operation mode of the current transformer. In addition, it was determined that the output data should be transmitted taking …

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Railway Transportation Of Tourists: Problems And Solutions, M.M. Talipov Aug 2020

Railway Transportation Of Tourists: Problems And Solutions, M.M. Talipov

Journal of Tashkent Institute of Railway Engineers

Uzbekistan is one of the top ten countries in the world in terms of the scale of tourism and the number of historical monuments. The cities of Samarkand, Bukhara, Khiva and Shakhrisabz are included in the list of UNESCO World Heritage Sites. The country has created the necessary conditions that meet the requirements of tourists, more and more existing directions are expanding. The peace and stability prevailing in our country, the atmosphere of goodness and mercy, Uzbek hospitality known throughout the world are an important factor in capturing the flow of tourists arriving in our country.

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Recovery Of Worn Parts By Electrodes, Sh.Kh. Yuldashev, M.N. Masharipov Aug 2020

Recovery Of Worn Parts By Electrodes, Sh.Kh. Yuldashev, M.N. Masharipov

Journal of Tashkent Institute of Railway Engineers

Studies have been worked on the restoration of various perishable parts with welding. The main purpose of the research is to increase the strength of the working surfaces of parts different coating by welding different types of covered electrodes. Studies have been carried out to determine the composition, structure, rigidity and eroding resistance of the welded covering material. As a result of laboratory research, the optimal composition of the covering material is determined and the optimal method of welding them to the eroded working surface of the parts is selected.

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Increase In The Throughput Capacity Of The “D-S” Section In Railway Transport, S.K. Khudayberganov, S.A Abduqodirov Aug 2020

Increase In The Throughput Capacity Of The “D-S” Section In Railway Transport, S.K. Khudayberganov, S.A Abduqodirov

Journal of Tashkent Institute of Railway Engineers

This article analyzes the current state of the throughput capacity of the railway section D-S. Based on foreign experience, research was carried out and measures were developed to increase the capacity of trains on the site. After analysis, the site’s throughput capacity was presented at Uzbek Railways JSC.

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Methodological Approach To Substantiating Economically Feasible Volumes Of Work In The Road Sector, I.M. Tsarenkova Aug 2020

Methodological Approach To Substantiating Economically Feasible Volumes Of Work In The Road Sector, I.M. Tsarenkova

Journal of Tashkent Institute of Railway Engineers

This paper presents the results of a study aimed at developing methodological bases for selecting the most rational management decisions in the current economic situation to improve the transport and operational condition of individual sections of roads and the development of the national road network. The relevance of road infrastructure modernization as a system of measures aimed at improving it and improving consumer qualities is proved. In this regard, the theoretical substantiation of the content of the concept "modernization of highways" and the characteristics of the types of work performed in this case are presented. In the development of the …

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Calculation Of Seismic Resistance Of Reinforced Concrete Railway Spans Without Prestressing Reinforcement, U.Sh. Raxmanov, G.B. Ismailova Aug 2020

Calculation Of Seismic Resistance Of Reinforced Concrete Railway Spans Without Prestressing Reinforcement, U.Sh. Raxmanov, G.B. Ismailova

Journal of Tashkent Institute of Railway Engineers

The article discusses the calculation of earthquake resistance of reinforced concrete rail spans without prestressing reinforcement. The calculation is made for the main and special combination of loads. The calculation results show that with a design seismicity of 8 points, the bending moment in the middle of the beam span will significantly decrease compared to a design seismicity of 9 points

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Nonlinear Innovation Identification For Ship Maneuvering Modeling Via The Full-Scale Trial Data, Chunyu Song Aug 2020

Nonlinear Innovation Identification For Ship Maneuvering Modeling Via The Full-Scale Trial Data, Chunyu Song

Maritime Safety & Environment Management Dissertations (Dalian)

No abstract provided.

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