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.

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.

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.

Effect of Family Cohesion on Depression of Chinese College Students in the COVID-19 Pandemic: Chain Mediation Effect of Perceived Social Support and Intentional Self-Regulation

Individuals’perceptions,attitudes,and patterns of getting along with family members are important factors influencing Chinese people’s self-evaluation.The aim of this study was to investigate the effect of family cohesion on depression and the role of perceived social support and intentional self-regulation in this association.A hypothesized model of the association of family cohesion,perceived social support,intentional self-regulation,and depression was examined.A convenience sampling method was used to survey 1,180 college students in Yunnan Province using self-report.Data were collected using the Family Cohesion Scale,the Perceived Social Support Scale,the Intentional Self-Regulation Scale,and the Center for Epidemiological Studies Depression Scale.The findings revealed low to moderate correlation between the variables studied.College students’family cohesion was a negative predictor of their depression.This association was also mediated by the knock-on effect of perceived social support and intentional self-regulation.These findings show how family cohesion affects college students’depressive status.Specifically,these results help demonstrate the importance of family cohesion,perceived social support,and intentional self-regulation in optimizing students’depression,which in turn can promote better psychological states.

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.

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.

使用IBM Installation Factory简化Web Sphere Application Server的安装和部署

本文重点介绍了IBMInstal-lation Factory(以下简称IF)的主要功能,讲解如何使用IF生成定制安装包和集成安装包,以及如何使用生成的定制安装包和集成安装包来简化和标准化Web Sphere Application Server的安装和部署。

One-Step-Installation of Offshore Wind Turbine on Large-Scale Bucket-Top-Bearing Bucket Foundation

In 2010,the first offshore wind turbine with integrated installation was established in Qidong sea area of Jiangsu Province,China,which led to the implementation phase of one-step-installation technique based on the design and construction of large-scale bucket-top-bearing (LSBTB) bucket foundation.The critical technique of LSBTB bucket foundation included self-floating towing,penetration with adjustment of horizontal levelness,removability and one-step-installation.The process of one-step-installation included the prefabrication of LSBTB bucket foundation in onshore construction base,installation and debugging of wind power,overall water transportation of foundation and wind power system,and installation of foundation and offshore wind turbine on the appointed sea area.The cost of one-step-installation technique was about 5 000 Yuan/kW,which was 30%-50% lower than that of the existing technique.The prefabrication of LSBTB bucket foundation took about two months.During the one-step-installation process,the installation and debugging of wind power and overall water transportation need about one to two days in sea area within 35 m depth.After the proposed technique is industrialized,the cost will be further reduced,and the installation capacity is expected to be up to 500 wind turbines per year.

Valuation of the flexibility in decision-making for revamping installations―A case from fertilizer plants

This paper puts forward a valuation model for the flexibility of revamping urea plants based on the substitutability of switching between the internationally accepted fertilizer feedstock fuel oil and natural gas. The paper first builds a stochastic mean-reversion model for fuel oil prices and natural gas prices respectively, then estimates and tests the parameters using the fuel oil and natural gas prices data from the U.S. market. This paper also conducts a sensitivity analysis with important parameters. The results show that the real option method can be applied successfully to evaluate the flexibility in decision- making for revamping installations in fertilizer plants or other similar plants.

An Installation System of Deepwater Risers by An S-Lay Vessel

Along with the consumption increase of the petroleum products, more countries have transferred their attentions to the offshore fields, especially the deepwater oil and gas reserves. For deepwater exploitation, the risers must be installed to act as the conduits connecting surface platforms to subsea facilities. In this paper, the typical risers sorted by different classes are introduced, and the correspondent installation methods are presented. By investigating the recent projects performed in the deepwater hot spots, and combining the challenges of HYSY20 l for riser installation, a lifting device developed for assisting riser installation is proposed and detailed to satisfy the installation of deepwater risers in the LW3-1 Gas Field of 1500 m in the South China Sea. Tests on both the functions and performances of such a new system exhibit the satisfaction of meeting all challenging requirements of HYSY201 for application to riser installation in waters up to a depth of 3000 m in the South China Sea.

The self-regulation process and its mechanism of channels' bed changes in the Changjiang(Yangtze) Estuary in China

Recent bathymetric changes in the Changjiang Estuary under the influence of artificial regulation engineerings and basin reservoirs have been analyzed based on the maritime charts since 1997 and recent fieldworks. The results indicate a slight erosion of the channels in the upper and middle estuary, continuing deposition and seaward move of the mouth bar crest and intensifying erosion at the nearshore seabed. It is noteworthy that the morphological evolution caused by intensive human activities dominates over the changes from nature process. First, the riverbes are eroded overall in the South Branch （SB）, the South Channel （SC） and the upper and middle reaches of the North Channel （NC）. The nearshore seabed outside the river mouth is being eroded slightly, which is attributed to the declining sediment supply from the Changjiang Basin due to the construction of the Three Gorges Dam upstream. The sediment above the seabed is very active and coarsened, meanwhile, sand waves are becoming more distinct. Second, a deposition occurs in the North Brach （NB）, the mouth of the NC, the mouth bars of the North Passage （NP） and the South Passage （SP） and especially the main channel of the NP, where it shows a massive siltation after the deep waterway project. The reasons for the recent changes are not only the dynamic structure in estuarine mouth bars, but also the supply of sediment resuspension in a local and offshore area. Meanwhile, the severe erosion and siltation in some reaches is related to the construction of estuarine engineerings. It is indicated that the Changjiang Estuary is gradually self-adjusted and adapting to the varying natural factors and intensive human activities. The study on the mechanism of self-regulation of the recent bathymetric changes in the Changjiang Estuary has important and practical significance.

Analysis on Interface Shear Stress of Thermally InsulatedOcean Pipelines Under Installation

It has been proved that the thermally insulated ocean pipeline has advantages over the conventional pipe-in-pipe pipeline. The risk of using the thermally insulated pipeline is that the exterior layers covering the steel pipe may be. pulled off if the shear stress on the interface induced by the pullout fore from the tensioner is greater than the binding fore between two neighboring layers during installation. This paper develops a procedure to calculate the shear stress on the interface. The binding force between two neighboring layers can be determined with full scale model tests. The safety of the thermally insulated pipe under installation can then be checked by comparison of the interface shear stress with the binding force.

The Survey of Self-Regulation Behaviors and Related Factors in Elderly with Hypertension in South-East of Iran

Hypertension is one of the most important risk factors for heart diseases today. The effect of hypertension in the elderly is higher than other age groups and it may lead to changes in their quality of life. By the increase of age, the amount of self-care behaviors of patients with hypertension decreased. Therefore, control and self-care behaviors are so important. This study has been conducted to study self-regulation behaviors and Associated Factors in elderly patients with hypertension. This study was a cross sectional, descriptive analytic study, which was conducted using multistage sampling on the elderly 60 years and above with hypertension. The sample size was calculated 365 and the final sample size of 380 people was considered by possible losses. The instruments include of demographic and self-regulatory behaviors questionnaire. The results showed that self-regulation of behavior was 42.3% of the total score. In terms of quality, only 7.4% of the elderly had good behavior, 46.6% of poor performance, and the rest were mediocre performance. Age (p = 0.03), gender (p = 0.02), education (p = 0.001), income level (p = 0.03) and marital status (p = 0.001) significantly associated with behaviors of self-regulation. The results generally indicate unfavorable self-regulation of elderly patients with hypertension. Some variables such as gender, age, marital status, education and income levels were associated with these behaviors. So paying attention to the education of the elderly in care centers is essential.

Numerical Simulation of Float-Over Installation for Offshore Platform

In this paper,a numerical investigation of a float-over installation for an offshore platform is presented to verify the feasibility of the actual installation.The hydrodynamic performance of a T-barge is investigated in the frequency domain,and the coupled motions are analyzed in the time domain.We then compare with those of the model test and determine that the response amplitude operator and the time series agree quite well.The barge exhibits favorable hydrodynamic behavior in the considered sea state,and the equipment loads are allowable.Themooring systemand sway fender forces are within the permissible range.Based on these results,we can verify that the actual installation of the offshore platform is feasible.We accurately simulated many important factors and effectively reduced the risk associated with the offshore installation,which is of great importance.As such,we demonstrate that the numerical simulation of the float-over installation for offshore platforms has practical engineering significance.

Electric-Arc Plasma Installation for Preparing Nanodispersed Carbon Structures

An electric-arc plasma installation operated in the hidden anode arrangement is constructed and used for the preparation of carbon nanostructures. A contracted plasma arc generated by a plasma torch using an inert gas is used as heat source. The average mass temperature of arc is higher than 10^4 K, while its power density, which is directly transferred onto the electrode （anode）, is - 2 kW/mm^2. The anode contact area formed on the electrode moves against the arc by way of shifting the electrode and is hidden completely in the interior of plasma gas stream moving towards it. As a result of both the direct plasma attack and the opposite movement of streams in the hidden anode contact area, a temperature higher than 6000 K is reached. Thus, intensive vaporization takes place, which forms a saturated plasma-gas-aerosol phase of the initial material of electrode （anode）. This gas phase is mixed in and carried by the plasma stream. Over that mixed plasma stream, a controlled process of quenching （fixation） is carried out by twisted turbulent fluid streams. After the fixation, the resultant carbon nano-structures are caught by a filter and collected in a bunker.

Preparation and Characteristic of Self-regulation Water-transmitting Coating Fiber

Common clay, Kaolin and Bentonite were used as additives to prepare water-transmitting coating fiber, respectively, and the water-transmitting characteristic of coating fiber was studied. Different water-transmitting coating fibers were prepared by coating fiber using coating material with different mass proportions of additives to adhesive. And the coating materials were made from three kinds of inorganic clays as additives respectively and polyvinyl alcohol （PVA） as adhesive. Furthermore, the surface morphology and water-transmitting capacity of coating fiber were studied by SEM, Perkin Elmer Diamond SII thermal multi-analyzer and instrument for quick measurement moisture M30. The experimental results indicate that water-transmitting coating fibers made from three kinds of clays all have water-transmitting capacity. The surface of water-transmitting coating fiber prepared by common clay T is continuous and compact, and the water-transmitting effect is better than coating fibers made from other clays.

Longitudinal Vibration Analysis of Marine Riser During Installation and Hangoff in Ultra Deepwater

This paper is concerned with the problem of longitudinal vibration of a 3,000 m long disconnected drilling riser during installation and hangoff operation.The natural frequency,amplitude of vibration displacement and vibration force of longitudinal vibration have been determined with consideration of the damping effect of the sea water.Results show the natural frequency of riser under these two situations are both decrease with the increase of water depth.The natural frequency of riser in installation operation is bigger than that in hangoff operation.The vibration displacement in hangoff configuration is bigger than that in installation while the vibration force in hangoff configuration is smaller than that in installation configuration.Under the condition of resonance,the vibration displacement increase along riser from top end to the bottom end while the vibration force increase along riser from riser bottom end to the top end.

Dynamic Analysis of A Subsea Suspended Manifold Going Through Splash Zone During Installation

The subsea suspended manifold designed to replace the traditional foundation structure with the buoys is a new generation subsea production system that can be suspended at a certain height from the seafloor and rapidly recycled by its own buoyancy.Due to complex environmental conditions,its hydrodynamic performance in the splash zone is extremely important for the safety of the whole installation process.In this paper,the mathematical model for the dynamic analysis of the seawater ingress process of the single-layer pre-set horizontal cabin is proposed based on the different center of gravity positions of the buoy.Meanwhile,the theoretical analysis of fiber cable is divided into infinite differential units by the discretization method,and the formulae of the horizontal displacement of the subsea suspended manifold are presented.In addition,the simulations are carried out to verify the rules of the dynamic responses on the subsea suspended manifold system with the consideration of the environmental conditions in the South China Sea.Comparing with the calculated value of the mathematical model of the cabin water ingress,the error of the simulation result by use of FLUENT is about 5.47%.Furthermore,the wave height is greater than the current impact on the lowering manifold system and the azimuth angle of the installation vessel is aligned with the direction of the environmental load.

A retrievable sensor installation technique for acquiring high frequency signals

The use of in-seam waves for void detection in mines requires the capability of capturing high frequency signals over large distances. For instance, the Airy phase of Love waves which are used for void detection in coal mines ranges from several hundred to over one thousand Hertz and the expected travel distance of these signals is at least 90 m （equivalent to a detection distance of 45 m） for the technique to be considered practical. In order to obtain high quality and broadband signals, sensors are conventionally grouted at the bottom of boreholes so that the attenuation due to the fractured surface is minimized and the coupling effect is improved. However, to be economically feasible, the expensive and high sensitive sensors must be retrievable so that they can be used repeatedly at the same or other locations. Because of these concerns, a retrievable sensor installation technique was developed. This paper provides a detailed review of the technique as well as a brief discussion of its applications. The technique is simple and reliable for both installation and retrieval operations and can be used for boreholes oriented in any directions. The technique has been demonstrated in over 200 sensor installation/retrieval operations under various borebole conditions, including bituminous coal, anthracite coal, shale, sandstone and trona. With this technique, we were able to detect the high frequency signals required for our projects. For instance, the signals used at a trona mine for void detection have a typical frequency of 5 kHz with the travel distance of 150-200 m. The results of these operations have shown that sensors installed in the prescribed manner exhibit predictable, consistent, and repeatable performance. The technique also provides an economical and reliable means for many other field seismic monitoring applications where high quality and broadband signals are essential, such as microseismic monitoring and geotomography studies.