Experimental Study on the Sinking and Leveling of A Large-Capacity Offshore Wind Turbine Five-Bucket Foundation in Sand

As offshore wind farms expand into deeper and farther ocean regions and the unit capacity of offshore wind turbines(OWTs)increases,there is a pressing need for a new foundation structure that can accommodate deep-sea conditions and support large capacities while maintaining economical and safe.To meet this goal of integrated transportation and one-step installation,a novel five-bucket jacket foundation(FBJF),with its suction installation and leveling methods in sand,has been proposed,analyzed and experimentally studied.First,seepage failure experiments of the FBJF at various depths were conducted,and a formula for calculating the critical suction of seepage failure suitable for the FBJF in sand was chosen and recommended for use with a range of values for the permeability coefficient ratio.Second,through leveling experiments of the FBJF at different depths,the maximum adjustable leveling angle during the sinking process was defined using seepage failure and the adjustable leveling angle of the foundation as control criteria.Various leveling control strategies were proposed and verified.Finally,an automatic sinking and leveling control system for the FBJF was developed and experimentally verified for feasibility.

Simplified prediction models for acoustic installation effects of train-mounted equipment

Acoustic models of railway vehicles in standstill and pass-by conditions can be used as part of a virtual certification process for new trains.For each piece of auxiliary equipment,the sound power measured on a test bench is combined with meas-ured or predicted transfer functions.It is important,however,to allow for installation effects due to shielding by fairings or the train body.In the current work,fast-running analytical models are developed to determine these installation effects.The model for roof-mounted sources takes account of diffraction at the corner of the train body or fairing,using a barrier model.For equipment mounted under the train,the acoustic propagation from the sides of the source is based on free-field Green’s functions.The bottom surfaces are assumed to radiate initially into a cavity under the train,which is modelled with a simple diffuse field approach.The sound emitted from the gaps at the side of the cavity is then assumed to propagate to the receivers according to free-field Green’s functions.Results show good agreement with a 2.5D boundary element model and with measurements.Modelling uncertainty and parametric uncertainty are evaluated.The largest variability occurs due to the height and impedance of the ground,especially for a low receiver.This leads to standard deviations of up to 4 dB at low frequencies.For the roof-mounted sources,uncertainty over the location of the corner used in the equivalent barrier model can also lead to large standard deviations.

Engineering and Physical Bases of Development and Creation of Plasmochemical Reactors for Mobile Facilities for Medical Waste Disposal

This paper presents the results of the development and creation of plasma-chemical reactors for mobile and stationary installations for the destruction and disposal of solid, liquid, gaseous and mixed medical waste based on the domestic plasma generator PUN-1, with air as the plasma-forming gas. The design and principle of operation of plasma-chemical reactors installed on mobile experimental and industrial plants “Plazmon-1,2,3”, as well as the main features of the plasma waste disposal process are described.

Chinese Economy Scales New Heights

The positive figures of last year confirm the strength,resilience,and prospects of the Chinese economy.CHINA’S government work report delivered to the 2024“Two Sessions”in early March released some important statistics.The GDP surpassed RMB 126 trillion,an increase of 5.2 percent.A total of 12.44 million urban jobs were added,and the average surveyed urban unemployment rate stood at 5.2 percent by average.The consumer price index(CPI)rose by 0.2 percent.The production and sales of new-energy vehicles accounted for over 60 percent of the world’s total.Grain output hit a record high of 695 million tonnes.The installed renewable energy capacity surpassed its thermal power for the first time in Chinese history,accounting for over half of newly installed renewable energy capacity worldwide.The per capita disposable income of residents also rose by 6.1 percent nationwide.

Digital Twins:A New Model for Urban Governance

Avivid three-dimensional rendering of a bridge appeared on the intelligent monitor and evaluation platform at Beijing Yunlu Technology Co.,Ltd.,pointing to key factors of bridge health.Real-time status,events,transportation navigation,and traffic conditions were all tracked on the screen.Numerous sensors installed on bridge track every minor dynamic change on the bridge surface and perform digital analysis.

Speeds Up the Construction of a New Power System

"In 2023,China's photovoltaic industry continued to maintain a rapid development momentum,with an additional installed capacity of more than 216 GW,accounting for more than half of the global total.The cumulative installed capacity is close to 610 GW,which helps the installed capacity of renewable energy surpass that of thermal power historically.In 2023,the output value of the domestic photovoltaic manufacturing industry exceeded RMB1.75 trillion,a year-on-year increase of 17.1%,and the output of the four main industrial chains of polysilicon.

Translation Theory and Techniques in Optometry Literature: A Case Study of the “Optoform 80 Installation and Maintenance Manual”

Translation of specialized documents in optometry presents unique challenges,requiring a deep understanding of the professional context,terminology,and adherence to specific translation styles.This paper delves into the translation theory and techniques employed in the English-to-Chinese translation of the“Optoform 80 Installation and Maintenance Manual”,serving as a case study.Emphasizing Nida’s theory of functional equivalence,the paper explores the complexities of translating professional optometry literature,focusing on key points and common issues in translating installation and maintenance manuals for optometric devices.Special attention is given to the translation of professional terminology,employing methods such as addition,omission,conversion,and repetition.The translation process aims to meet specific requirements,ensuring accuracy and coherence while aligning with Chinese language conventions.The paper also analyzes translation methods and techniques concerning terminology,prepositions,conjunctions,and handling parallel elements based on practical insights from the Optoform 80 Manual.

Construction Safety Management of Mechanical and Electrical Installation Projects

Various industries today rely on the support of electromechanical equipment,expanding its scope of application and leading to an increase in electromechanical installation projects.However,due to the high level of expertise required and the potential risks involved,it is crucial to emphasize safety management during construction.This paper delves into the significance of construction safety management for electromechanical installation projects,identifies common problems encountered during construction,and proposes solutions.This analysis aims to provide relevant personnel with essential guidance and references for managing electromechanical installation projects safely.

Return to Reality:Speculative Design of Interaction Ritual Chains and Exploration of Alone Together

“Alone together”is an ever-changing“wicked problem.”In this research and practice,the author tries to combine experience design,referring to the theory of“interaction ritual chain theory,”and creatively add interactive experience to discursive works,so that the audience can think between the real and the virtual.

New Quality,Great Potential

Here are some of the achievements China made in 2023:GDP exceeded 126 trillion yuan($17.43 trillion)with a growth of 5.2 percent;12.44 million new urban jobs were created;average surveyed unemployment rate in urban areas was 5.2 percent;consumer price index increased by 0.2 percent;new energy vehicle production and sales accounted for more than 60 percent of the global share;grain output reached a record high of 695 billion kg;installed renewable energy capacity surpassed thermal power capacity for the first time in history,and China accounted for over half of newly installed renewable energy capacity worldwide;per-capita disposable income of residents increased by 6.1 percent…

Research on the Application and Development of Digital Media Art in Urban Public Space Design

Digital media art is an emerging art form that combines digital technology and media art.It has huge potential to bring innovation to urban public spaces and provide them with vibrant artistic experiences.This article analyzes the design significance and value of digital media art in urban public space,its various forms of application in urban public space design,and the innovative ideas and paths that digital media art can take in urban public space to guide the future.The application and innovative methods of digital media art in urban public space design provide certain theoretical and practical references for urban planners and designers.

Construction Engineering,Equipment Installation,Construction Engineering

At present,with the development of society,China’s civil construction equipment installation engineering has many majors,complete catego-ries and high functional requirements.In particular,the installation of the equipment is a large amount of work,with a large number of types of work,with a strong degree of specialization,and also technically complex.In the construction of construction projects in China,the installation of engineer-ing equipment is a key control point of construction safety,and equipment installation has always been a key point that construction enterprises at-tach great importance to.The installation of engineering equipment will not only affect the overall progress of engineering construction,but also affect the quality of the project,therefore,the installation of construction equipment has played a vital role and has attracted increasing attention.Combined with the actual situation of construction enterprises,this paper briefly introduces some problems and solutions existing in the construction of construction enterprises.

Construction Technology of Lightning Protection Devices in Building Electrical Installation Engineering

To better improve the electrical safety of buildings and fulfill the role of lightning protection and grounding,this article combines cases and discusses seven aspects of lightning protection devices’construction technology.These aspects include the lightning protection classification of buildings,air terminals,down conductors,grounding devices,division of lightning protection zones,and lightning electromagnetic pulse shielding.Through the introduction of this article,readers can gain a comprehensive understanding of the application and value of lightning protection grounding construction technology in building electrical installation projects.

Use of Geosynthetic Access Mats in Construction

A stable surface to move manpower and equipment is a key for the construction operations. To create a stable road surface, the road construction techniques are time-consuming and expensive for a traditional construction which requires compaction of soil, aggregate base, sub-base and asphaltic layers. A Geosynthetic Access Mat (GAM) system can serve as an alternative to other traditional construction techniques to accommodate temporary construction. Due to its rigidity, the mat system can provide substantial vertical resistance to the applied load under a large deflection subject to soil conditions. This paper provides details of GAM specifications, soil conditions, applications, installation procedure, comparison with other soil stabilization methods and Aramco experience for deployments of these mats.

Performance of a Combined Energy System Consisting of Solar Collector, Biogas Dry Reforming and Solid Oxide Fuel Cell: An Indian Case Study

An energy production system consisting of a solar collector, biogas dry reforming reactor and solid oxide fuel cell (SOFC) was assumed to be installed in Kolkata, India. This study aims to understand the impact of climate conditions on the performance of solar collectors with different lengths of parabolic trough solar collector (dx) and mass flow rate of heat transfer fluid (m). In addition, this study has evaluated the amount of H2 produced by biogas dry reforming (GH2), the amount of power generated by SOFC (PSOFC) and the maximum number of possible households (N) whose electricity demand could be met by the energy system proposed, considering the performance of solar collector with the different dx and m. As a result, the optimum dx was found to be 4 m. This study revealed that the temperature of heat transfer fluid (Tfb) decreased with the increase in m. Tfb in March, April and May was higher than that in other months, while Tfb from June to December was the lowest. GH2, PSOFC and N in March, April and May were higher than those in other months, irrespective of m. The optimum m was 0.030 kg/s.

Cooling System Design Optimization of an Enclosed PM Traction Motor for Subway Propulsion Systems

This paper presents the design optimization of a self-circulated ventilation system for an enclosed permanent magnet(PM)traction motor utilized in the propulsion systems for subway trains.In order to analyze accurately the machine's inherent cooling capacity when the train is running,the ambient airflow and the related heat transfer coefficient(HTC)are numerically investigated considering synchronously the bogie installation structure.The machine is preliminary cooled with air ducts set on the motor shell,and the fluidic-thermal field distributions with only the shell air duct cooling are numerically calculated.During simulations,the HTC obtained in the former steps is applied to the external surface of the machine to model the inherent cooling characteristic caused by the train movement.To reduce the temperature rise and thus guarantee the motor's working reliability,an internal self-circulated air cooling system is proposed according to the machine temperature distribution.The air enclosed in the end-caps is driven by the blades mounted on both sides of the rotor core and forms two air circuits to bring the excessive power losses generated in the heating components to cool regions.The fluid flow and temperature rise distributions of the cooling system's structural parameters are further improved by the Taguchi method in order to confirm the efficacy of the internal air cooling system.

Studies on Suction-Assisted Installation Behavior of Suction Caissons in Clay Under Various Undrained Shear Strengths

Suction caissons are widely used for anchoring floating platform and offshore wind turbines.Penetration of the suction caisson into the desired position under the combination of its self-weight and applied suction resulted from pumping out the encased water is integral to practical engineering.Model tests were carried out to investigate the suctionassisted installation of suction caissons in clay under various undrained shear strengths.It was found that there exists a critical penetration depth value.When the penetration depth is smaller than the critical value,the soil plug undrained shear strength is higher than intact clay(i.e.,clay prior to installation).However,when the penetration depth is greater than the critical penetration depth,the undrained shear strength of soil plug is lower than intact clay.The critical value decreases with the increasing consolidation time and undrained shear strength of clay.During suction-assisted installation,cracks occur around suction caissons.The installation way has little effect on the crack formation.The influence range(i.e.,the maximum distance between the crack and the suction caisson edge)was found to increase with the increasing friction coefficient of interface between the suction caisson wall and soil and decreases with the increasing soil undrained shear strength.In addition,the drained condition of the clay during installation is dominated by the caisson aspect ratio,the undrained shear strength and the friction coefficient between the caisson wall and clay.Equations to estimate the penetration resistance and the required suction to install the suction caisson are summarized.

Dynamic Analysis of A Deep-Water Compliant Vertical Access Riser with A Variable Length During Installation

Compliant vertical access risers(CVAR)have broad application prospects in deep-water oil and gas transportation.However,the mechanical behaviors of the CVAR with a variable length during installation remains unclear.To address this issue,based on the flexible segment method,a model of CVAR with a variable length during installation is established in this study,which is verified by the comparison with commercial software.Then,the mechanical behaviors of CVAR during installation are investigated.The results reveal that the CVAR configuration is significantly affected by the buoyancy blocks.The streamwise displacement of CVAR increases with the increase of current velocity.When the BOP weight is insuffcient,obvious upbending is observed in the lower region and transition region,leading to local compression.When the platform moves in the opposite direction to the current,the maximum stress is larger than that of the scenario when the platform moves in the same direction as the current.

Application of integrated simulation environment SIEMNED to the analysis of the MEPHIST-0 tokamak operation

This paper presents the results of numerical simulation of plasma equilibrium and stability in the MEPHIST-0 tokamak with SIEMNED software and comparison of simulation results with experiments.The determined characteristics of the vacuum chamber show that it significantly affects the entire discharge.For various scenarios of the inductor operation,a comparison of experimental data and simulated currents and magnetic fields induced in the chamber was carried out.For steady-state tokamak operation,a numerical study of equilibrium plasma configurations was carried out depending on the currents in the poloidal magnetic field coils and plasma current.The vertical plasma instability was investigated.The limiting values of plasma ellipticity preventing the vertical plasma instability were numerically determined.Numerical simulations show that plasma equilibrium is supported by induced currents.It was shown numerically that magnetic configuration with‘zero of higher order’were obtained before the plasma shot,suggesting consistency between the simulation results and observations.

Studies on Performance of Distributed Vertical Axis Wind Turbine under Building Turbulence

As a part of the new energy development trend,distributed power generation may fully utilize a variety of decentralized energy sources.Buildings close to the installation location,besides,may have a considerable impact on the wind turbines’operation.Using a combined vertical axis wind turbine with an S-shaped lift outer blade and-shaped drag inner blade,this paper investigates how a novel type of upstream wall interacts with the incident wind at various speeds,the influence region of the turbulent vortex,and performance variation.The results demonstrate that the building’s turbulence affects the wind’s horizontal and vertical direction,as well as its speed,in downstreamplaces.The wall’s effect on wind speed changing in the downstreamarea is thoroughly investigated.It turns out that while choosing an installation location,disturbing flow areas or low disturbing flow zones should be avoided to have the least impact on wind turbine performance.