Line Sections Research Articles

Numerical modelling of the cool-down of the helium transfer-lines for FRIB LINAC and experimental systems

The cryogenic distribution system at FRIB is extensive, encompassing three Linac segments, fourteen experimental system superconducting magnets, cross-connect between FRIB and the reconfigured NSCL legacy system, and the A1900 magnets, as well as many other user experimental loads. The cool-down or warm-up of these transfer-lines is an inherently transient process and must be conducted at a gradual enough rate to keep local temperature gradients and corresponding thermal stress on the piping system within acceptable limits. To this end, estimation of this transient process is very helpful in operational planning. A two temperature (fluid and pipe wall) model was developed to capture the transient characteristics of the cool-down or warm-up process with real fluid properties, and considering the effects of heat in-leak, momentum, flow resistance, and piping components. It was employed to estimate the cool-down of different FRIB transfer line sections, and the results were compared against data obtained during actual cool-down of the transfer line.

Groundwater potential identification using electrical resistivity tomography method in Sendangrejo Village, Minggir District, Sleman Regency, Special Region of Yogyakarta

Groundwater is vital element for living. One of methods to identify groundwater potential is Electricity Resistivity Tomography (ERT). This study aims to identify the groundwater potential occurrence in Sleman, Yogyakarta through non-destructive geoelectrical surveys. Based on the ERT models and geological information, supported by hydrogeological data in the research area, drilling a well at the planned location was deemed necessary to reach a depth of at least 100 to 250 meters in order to tap into the maximum groundwater potential. Groundwater is predicted to flow and accumulate in the pores and fractures of rocks. Well drilling in the northern part of section line 1 was more favourable and recommended due to the lower elevation compared to the area of section line 2, where the drill location was originally planned at a higher elevation uphill. Layers of hard rock, presumably lava and breccia, have already been found at a depth of 5 to 15 meters based on historical open well excavations around the area. Identifying the characteristics of subsurface volcanic rocks during drilling is suggested to evaluate drilling and well planning. Well logging should be conducted to collect lithostratigraphy and rock mass information. Further tests of hydraulic conductivity for each potential layer.

KTX 경전선 복선화 마산선 구간이 합성1동 내 합포성지(合浦城址)에 미친 영향에 대한 연구

KTX 경전선 복선화 마산선 구간이 합성1동 내 합포성지(合浦城址)에 미친 영향에 대한 연구

Floating offshore wind turbine mooring line sections health status nowcasting: From supervised shallow to weakly supervised deep learning

The global installed capacity of floating offshore wind turbines is projected to increase by at least 100 times over the next decades. Station-keeping of floating offshore renewable energy devices is achieved through the use of mooring systems. Mooring systems are exposed to a variety of environmental and operational conditions that cause corrosion, abrasion, and fatigue. Regular physical in-service inspections of mooring systems are the golden standard for monitoring their health status. This approach is often expensive, inefficient, and unsafe, and for this reason, researchers are focusing on developing tools for digital solutions for real-time monitoring. Floating offshore renewable energy devices are usually equipped with a wide range of sensors, some low-cost, low/zero maintenance, and easily deployable (e.g., accelerometers on the tower), contrary to others (e.g., direct tension mooring line measurements), producing real-time data streams. In this paper, we propose exploiting the data coming from the first type of sensors for mooring systems health status nowcasting. In particular, we will first rely on state-of-the-art supervised shallow and deep learning models for predicting the health status of the different sections of the mooring lines. Then, since these supervised models require types and amount of data that are seldom available, we will propose new shallow and deep weekly supervised models that require a very small amount of data regarding worn mooring lines. Results will show that these last models can potentially have practical applicability and impact for real-time monitoring of mooring systems in the near future. In order to support our statements, we will make use of data generated with a state-of-the-art digital twin of the mooring system, OrcaFlex11www.orcina.com ., for a floating offshore wind turbine reproducing the physical mechanism of the mooring degradation under different loads and environmental conditions. Results will show errors around 1% in the simplest scenario and errors around 4% in the most challenging one, confirming the potentiality of the proposed approaches.

From the history of drawing up drafts of the Belgorod region cities in the region of the Dnieper-Don interfluve 1590–1694

Importance. Based on the analysis of written and graphic materials of the Russian State Archive of Ancient Acts, it is proposed to consider the circumstances that influenced the drawing up of drawings in the key section of the Belgorod line – the territory of the Field in the Dnieper-Don interfluve.Research Methods. The methodological basis of the research is based on the desire to comply with the principle of consistency (involving a comprehensive consideration of facts, taking into account their development, relying on the structural and functional features of the subject), the principle of historicism (which is based on the study of historical phenomena, events and processes in accordance with their chronology and interrelation), the principle of objectivity (based on the fact that the sources and facts have objective content that allows us to reconstruct the historical past). The research is based on such general scientific methods as analysis, synthesis, generalization, and systematization.Results and Discussion. The totality of available information about drawings allows you to divide graphic materials into drawings of one city, a group of cities and individual localities. At the same time, the information content of graphic materials is directly related to the purposes of their compilation. If it is necessary to reflect the fortifications in the county, then only they are shown, although they are surrounded by arable land and the lands of serving people. This is a direct consequence of the fact that the fortresses and fortifications are under the jurisdiction of the Discharge Order. Arable land, hay mowing and other lands that are in use by serving people were taken into account in the Local Order. Such circumstances can be called the main factors influencing the information component of the drawings. The economic development of the territory went on in parallel with military defensive measures, despite the danger, the population sowed and harvested bread, moved around the territory for their needs, including beyond the line. The preparation of drawings in the 16th–17th centuries is an integral part of urban planning activities, sources allow us to identify two blocks of circumstances under which cartographic material is compiled: 1) upon inspection of large territories by special expeditions from Moscow and making copies according to available paintings and drawings covering large areas of copies of individual localities; 2) drawing up drawings during revision inspections of existing fortress cities and structures on their borders.Conclusion. Two types sources consideration through the structuring of materials according to the chronology and informativeness of a particular region made it possible to identify a number of drawings with the circumstances of their compilation and events occurring during this period in a particular territory. The considered examples, the proposed conclusions and conclusions make it possible to significantly expand the knowledge and importance of cartographic materials in the general system of state construction of fortress cities. At the same time, significant material has been identified that allows in the future to expand the designated topic, show the history and fate of drawings for a number of cities of the Belgorod region.

Knowledge, Attitude, and Practices Toward Kangaroo Mother Care Among Mothers in a Tertiary Neonatal Care Unit

Aim: To study the knowledge, attitude, and practices of Kangaroo Mother Care (KMC) among eligible postnatal mothers in the postnatal ward (PNW) and neonatal intensive care unit (NICU) of a tertiary neonatal unit in Eastern India. Methods: A cross-sectional survey was conducted among 100 mothers of low-birth-weight babies in our PNW and NICU. As part of the unit protocol, all mothers of eligible babies were counseled about KMC at first contact verbally as well as by using an informative video on KMC. Data was collected using a structured questionnaire after the routine counseling of the mothers on their first visit after delivery. The analysis of the data was done using appropriate statistics. Results: More than three-fourths (83.2%) of mothers had good knowledge of KMC. A good attitude toward using KMC was found in 91.6% of the mothers. Almost all the mothers (98%) knew the correct KMC position, and 12% of mothers had a previous preterm baby and had given KMC. Many mothers felt the small size of the baby, pain after cesarean section, and central or peripheral intravenous lines in the baby were barriers to KMC. Conclusion: The knowledge regarding KMC among mothers whose babies were admitted into the PNW/NICU was good. Though the attitude toward KMC was good, mothers felt there were multiple barriers to initiating KMC.

Effects of musical expertise on line section and line extension.

This study investigated whether music training led to better length estimation and/or rightward bias by comparing the performance of musicians (pianists) and non-musicians on performance of line sections and line extensions. One hundred and sixteen participants, among them 62 musicians and 54 non-musicians, participated in the present study, completed line section and line extension task under three conditions: 1/2, 1/3 and 2/3. The mixed repeated measures ANOVA analysis revealed a significant group × condition interaction, that the musicians were more accurate than non-musicians in all the line section tasks and showed no obvious pseudoneglect, while their overall performance on the line extension tasks was comparable to the non-musicians, and only performed more accurately in the 1/2 line extension condition. These findings indicated that there was a dissociation between the effects of music training on line section and line extension. This dissociation does not support the view that music training has a general beneficial effect on line estimation, and provides insight into a potentially important limit on the effects of music training on spatial cognition.

City-forming role of the Metro in Warsaw

The article analyses the continuous transformations in the spatial development of the western part of Warsaw from 2001 to 2022. The study utilises cartographic materials and temporal analysis, considering pedestrian travel times to planned metro stations in the Bemowo district. An investment analysis of single and multi-family buildings was conducted throughout the Bemowo district and near metro stations. The analysis is based on four time intervals to determine the speed and nature of changes and their impact on land development. The selected analysis periods are 2001–2005, 2005–2010, 2010–2016, and 2016–2022. In 2022, the construction of the last section of the second metro line commenced. The results indicate that the total number of buildings constructed in Bemowo within 833 m of the metro station increased by 298 between 2001 and 2022, representing a growth of 64.5 %. During the same period, the building area increased by 1,237,405 m2, corresponding to a growth of 136.2 % relative to the existing area. The highest increase in the number of new multi-family buildings was observed after 2016, providing evidence of the alignment of the construction and the second metro line station with the transit-oriented development (TOD) concept in the western part of Warsaw.

A step-by-step experimental characterization of a low-height acoustic barrier for railway applications

ABSTRACT The development of rail transport is crucial for transitioning towards a more sustainable form of mobility. It is imperative to address and mitigate issues regarding discomfort and noise pollution caused by rail traffic in order to foster a harmonious coexistence between the population and railway transport. In this paper, an experimental prototype of a low height acoustic barrier is characterized. The barrier has a high capacity for mitigating railway noise and has great potential for urban design. The acoustic barrier prototypes were initially developed using numerical models and subsequently subjected to a series of experimental tests. The initial experimental characterization was carried out in a semi-anechoic chamber. In the second phase, the prototypes were tested in a free field. The final phase of the experimental characterization involves the application of the noise barrier prototypes along a section of the Sintra railway line, located near Lisboa, Portugal. The results demonstrate the significant potential for noise mitigation offered by the developed solutions, achieving insertion loss levels of approximately 10 dB across the entire frequency range.

A new differential protection scheme based on Synchro-squeezing transform applied to AC Micro-Grid

In recent years, the protection of a microgrid has been a substantial challenge. This paper performs a differential protection scheme for the micro-grid based on Synchro-Squeezing Transform (SST). The proposed scheme protects the micro-grid in different modes i.e. islanded or grid-connected mode. Also, it is investigated in the ring and radial configuration. In the proposed scheme, currents on two sides of the line are measured by current transformers (CTs), and then differential current (IDiff) is calculated. This current is applied to extract the absolute value of the summation of the square root (ASSR). In this stage, transient and external faults without CT saturation and different switching such as connected or disconnected load/capacitor/distributed generation are detected from different internal faults. In the next stage, the frequency components of SST (FCSST) are extracted. By this feature, external fault and cross-country fault with CT saturation are detected. The proposed scheme is evaluated in noisy conditions, fault in different section of line with high resistance fault (HRF), and high impedance faults (HIF) of line. The micro-grid is simulated in PSCAD/EMTDC by various distributed generation (DG) like wind generation and photovoltaic systems penetrated at different buses. The proposed protection scheme is coded in MATLAB. The simulations represent the proposed protection scheme is correctly discriminate external and internal faults. At the same time, the method is immune to CT saturation and cross-country faults.

Неотражающие фильтры CВЧ (обзор)

The subject of the review is non-reflective microwave filters (NF) of various types, also called absorption filters. Brief information from the history of the creation of SF is provided. Directional filters are considered, which served as the prototype of non-reflective filters, NFs on lumped elements, non-reflective filters with loaded sections of transmission lines, non-reflective filters on coupled lines. All of these types of devices differ from conventional filters in that they remain matched both in and out of the operating passband (or non-passband). Part of the unwanted frequency spectrum of the signal entering the input of such filters is not reflected back to the signal source, but is absorbed in the filter itself. This operating principle of the NF ensures effective matching with other devices in the system, which is a key characteristic when designing wideband equipment with multiple output and output channels tuned to different frequencies. An assessment is made of the current state of development, prospects for miniaturization and improvement of the characteristics of non-reflective filters.

АНАЛІЗ РЕЗУЛЬТАТІВ ЕКСПЕРИМЕНТАЛЬНИХ ДОСЛІДЖЕНЬ НЕОДНОРІДНОСТІ МЕРЕЖІ ПОСТІЙНОГО СТРУМУ

The modes of breakage of one line of network sections with parallel lines in electrical distribution networks of power supply to consumers of direct current electric transport have been studied. An analysis of the experimental data was carried out, the results of which indicate the presence of a dependence of the value of the variable component in the rectified current on the distance to the damaged area. Mathematical modeling of the breakage mode of one of the line sections in the network with a serial connection of three sections, each of which has parallel lines, has been carried out. The obtained results of mathematical modeling of the modes of operation of a direct current network with heterogeneity of different sections also indicate the possibility of using the sixth harmonic of the current to determine the occurrence of heterogeneity and the section with this heterogeneity. To reduce the influence of load changes when determining an inhomogeneous section, it is proposed to control the input impedance of the network at a frequency of 300 Hz. It has been established that in these regimes the resistance angle changes the most. A method for determining the occurrence of local damage to a direct current line and the distance to this damage location is proposed, which is based on moni-toring the value of the line current and the input resistance of the line at a frequency of 300 Hz. References 7, Figures 4, Tables 2.

Experimental Monitoring of Dynamic Parameters of the Sub-Ballast Layers as a Prerequisite for a High-Quality and Sustainable Railway Line

Monitoring dynamic load transfer from train traffic to sub-ballast layers is crucial for verifying the reliability and safety of railway lines, assessing the design cost-effectiveness and achieving minimum environmental impact. For this purpose, measurements in labs, in situ or modeling the influence of dynamic loads on the immediate and long-term roadway quality are often performed using suitable software. The available test sections enabled monitoring of the dynamic loads and optimizing the critical spots where increased dynamic effects from railway traffic may occur. The subject of this paper is the calibration of the sensors installed in the different test sections of the trans-European corridor number V. As a result, the necessary input parameters for the subsequent numerical modeling of the dynamic effects on the track substructure and vibration propagation on the available sections of the upgraded railway line were obtained. The sensor calibration was carried out on the experimental field, part of the Experimental Basis of the Department of Railway Engineering and Track Management. As part of the calibration, the sensitivity of the sensors embedded in the track bed to the applied dynamic loads resulting from the impact effects of the lightweight deflectometer was assessed. The result of the calibration was the demonstration of sufficient sensitivity of the sensors and their suitability for implementation in an actual railway track structure, with the aim of obtaining relevant values of the response of the sub-ballast layers to dynamic loads and assessing the operational impacts on the sustainable environment. Also, the main result of the research was the possibility of using the theoretical–experimental route to optimize the layers of the railway body.

Research on rapid detection of characteristic parameters of aeroengine blade surface based on laser scanning

How to detect and evaluate the profile quality of aeroengine blades and provide technical support for blade manufacturing has become one of the key technical problems in the field of aviation manufacturing quickly and effectively. This paper studies the evaluation criteria of medium surface quality in the processing and manufacturing process of aeroengine blades, optimizes and innovates the fast extraction algorithms of various geometric parameters such as aeroengine blade section line, middle arc, front/rear edge center, front/rear edge radius, blade chord length, and chord angle, and establishes the evaluation criteria of aeroengine blade surface. According to the geometric relationship of blade chord length and front/rear edge radius in the blade section profile, the parameters are solved one by one through an optimization algorithm, combined with non-contact laser scanning measurement, and the blade detection efficiency is improved by more than 40%.

ОПТИМИЗАЦИЯ ПОЛУПЛОСКООВАЛЬНЫХ ГНУТОСВАРНЫХ ПРОФИЛЕЙ ДЛЯ БАЛОЧНЫХ КОНСТРУКЦИЙ.

A new technical solution for semi-flat bent-welded profiles is presented, optimized for bending strength characteristics, the originality of which has been confirmed by patent examination. Rectangular profiles with a ratio of width and height 1/3 along the middle section line served as the basis for their shaping, which ensures maximum strength. As a prototype, semi-flat profiles are assembled on the basis of flat-oval profiles with maximum strength due to the ratio of width and height 1/3.064 along the middle section line. The calculation of the optimal parameters of thin-walled sections using an approximate technique using their average lines, repeatedly tested in solving optimization problems for bent-welded profiles of various shapes and outlines, is presented. A comparative analysis of the design parameters revealed a positive effect of optimized profiles in truss and girder structures, including a reduction in the consumption of structural material, a decrease in stress concentration, and a reduction in building height. The prospects of expanding the scope of their rational use with the addition of pipe-concrete and steel-reinforced concrete structures are indicated.

A Novel Wideband Splitter for a Four-Element Antenna Array

In the paper, a novel design of a wideband power splitter for a four-element antenna array using two RF antiphase segments is proposed. Based on a detailed analysis of the power splitter circuit, an analytical model was set up in the MATLAB environment. The derived analytical model allows the development of a design of the described structure for any operating frequency and estimates the properties of the designed structure. In addition to the RF electrical part, the copper cover is also considered in this study. The copper cover serves as both a support and shielding part of the proposed structure. The electrical part consists of two sections of transmission lines. The first transmission line is symmetrical, while the second transmission line is asymmetrical. The given transmission lines can be realized using any technology (microstrip, coaxial, etc.). A prototype of the proposed wideband splitter operating at 650 MHz with a fractional bandwidth of 84.3% was designed and tested in real-world conditions to prove the concept. The board of the manufactured prototype has dimensions of 25 × 152 mm. A double-sided FR4 material with a substrate height of 1.48 mm, copper thickness of 50μm, and ϵr ≅ 4.3, with a dielectric loss tangent of 0.021 was used to manufacture the prototype. The prototype was tested and its parameters were verified in practical conditions as a part of the current radio communication system for the 5G band. Under these conditions, verification measurements of the proposed splitter with a four-element antenna array were carried out.

Optimization Analysis of Partition Wall Support Scheme of Multi-Arch Tunnel

With the fast progress of infrastructure projects, super-large cross-section projects are constantly emerging, and, therefore, engineering challenges and problems are increasing. Taking the triple-arch tunnel project in the turn-back line section of Santunbei Station in Urumqi Metro Line 1# as a case study, this research applied numerical simulation software Midas GTS/NX 2022 for the analysis of tunnel force and deformation in triple-arch cross-sections under different support forms of partition wall. Following the optimization of the support design of the mixed partition wall to a single straight wall, the following analytical results were obtained: surface settlement was decreased by 21.15% at the original cross-section; maximum values of principal stress and displacement of partition wall were decreased by 6.73 and 10.64%, respectively; and corresponding values for initial support structure were decreased by 21.47% and 54.74%, respectively. Meanwhile, combined with comparative analysis of engineering measurement and numerical simulation results, surface settlement and vault deformation were found to be similar to the optimized simulation results, which not only verified the reliability of simulation results but also ensured the safe and smooth construction of the project, greatly improving construction efficiency and saving construction time and cost.

Prompt gamma rays of terbium induced by inelastic scattering of fission neutrons

AbstractPrompt gamma rays of terbium emitted after (n,nʹγ) inelastic scattering reactions induced by irradiation of a terbium(III) hexahydrate (TbCl3·6H2O) sample with a beam of fission neutrons were investigated with the instrument FaNGaS (Fast Neutron-induced Gamma-ray Spectrometry) at an angle of 90° between neutron beam and detector. At sample position, the fast-neutron flux was 1.13 × 108 cm−2 s−1 and the neutron beam has an average energy of 2.30 MeV. We identified 124 prompt gamma lines from the 159Tb(n,nʹγ)159Tb reaction. Presence of prompt gamma rays from oxygen and chlorine was used for a concise verification of recently published results. Relative gamma-ray intensities, effective cross sections and fast-neutron spectrum-averaged partial production cross sections of the gamma lines are given including comparisons with available literature data. We found a reasonable agreement and the multitude of unreported lines adds decisive value to nuclear spectroscopy. Additionally, we estimated the detection limit of terbium as 1 mg for a counting time of 12 h.

A Decision Tree Based Ultra-high-speed Protection Scheme for Meshed MMC-MTDC Grids with Hybrid Lines

The reliable operation of modular multi-level converter based multi-terminal high voltage direct current (MMC-MTDC) grids requires high-speed and selective DC line protection. A single-ended protection technique is proposed for MTDC grids with offshore wind farms and hybrid lines that involve overhead lines and submarine cables in series. Positive and negative poles’ currents at one end of each line section are analyzed using discrete wavelet analysis (DWA). To classify fault type and identify fault zone, a fine decision tree is supplied with an energy index and the envelope slop of detail 1 coefficient (D1) obtained from DWA. Only 0.2 ms following the fault inception are needed for calculating the energy index and the envelope slope to perform relay functions. The approach was tested on a three-terminal two-poles ±\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\pm$$\\end{document} 400 kV MMC-MTDC model. The simulation results validate the effectiveness of the suggested protection technique under various fault scenarios, even with up to 200 Ω fault resistance. The proposed technique is not only able to detect the faulty line, but also it identifies overhead line faults and submarine cable faults for hybrid type lines. Moreover, the proposed technique is not affected by wind power injection changes, AC faults, or data noise. The simulated model was produced in the MATLAB/Simulink platform.

Modelling electrified railway signalling misoperations during extreme space weather events in the UK

Space weather has the potential to impact ground-based technologies on Earth, affecting many systems including railway signalling. This study uses a recently developed model to analyse the impact of geomagnetically induced currents on railway signalling systems in the United Kingdom during the March 1989 and October 2003 geomagnetic storms. The March 1989 storm is also scaled to estimate a 1-in-100 year and a 1-in-200 year extreme storm. Both the Glasgow to Edinburgh line, and the Preston to Lancaster section of the West Coast Main Line are modelled. No “right side” failures (when unoccupied sections appear occupied) are suggested to have occurred during either storm, and the total number of potential “wrong side” failures (when occupied sections appear clear) is low. However, the modelling indicates “right side” and “wrong side” failures are possible on both routes during the 1-in-100 year and 1-in-200 year extreme storms, with the Glasgow to Edinburgh line showing more total misoperations than the Preston to Lancaster section of the West Coast Main Line. A 1-in-100 year or 1-in-200 year extreme storm would result in misoperations over an extended period of time, with most occurring over a duration of 2–3 h either side of the peak of the storm.