Simulation of Continuous Tension Stringing Process of Conductor with Bending Stiffness Model

At present, there is no research on the calculation of tension variation of the conductor with bending stiffness model between the continuous span during tension stringing construction. Aiming at the typical terrain with large elevation difference in UHV project, a vector finite element method for calculating the tension of the conductor with bending stiffness model passes through the pulley in the process of tension stringing is proposed. The process of the wire rope under the action of the tractor pulling the conductor passes through the pulley continuously is realized. The variations of tension of tensioner and tractor, reaction force of pulley and envelope angle of the conductor passes through the pulley are obtained by simulation of tension stringing conditions such as 1 pulls 1, 1 pulls 2, etc, which provides reference for equipment selection for the tension stringing construction of mountain terrain with large elevation difference.

Changes in Anterior and Posterior Corneal Elevation in Patients With Allergic Conjunctivitis

Purpose: To evaluate corneal elevation changes in patients with allergic conjunctivitis (AC) and to analyze their correlations with ocular allergy signs and corneal biomechanical alterations.Methods: Thirty patients (30 eyes) with AC and twenty normal subjects (20 eyes) were included in this prospective study. All participants underwent a complete ocular examination, including corneal tomography by Pentacam and corneal biomechanics evaluation by Corvis ST. AC patients were evaluated for their eye rubbing frequency and ocular allergic signs.Results: The elevation at the thinnest location (TE) and the central location (CE), the elevation difference at the thinnest location (TED) and the central location (CED), and the mean value of elevation difference in the central 4 mm zoom (MED) of both the anterior and posterior corneal surface were significantly higher in the AC group than in the normal group (p < 0.05 for all). In AC patients, only anterior corneal elevation parameters were positively correlated with eye rubbing frequency and ocular allergy sign severity (p < 0.05 for all), while the tomography and biomechanical index (TBI) was positively correlated with the elevation parameters of both the anterior and posterior corneal surfaces (p < 0.05 for all).Conclusion: AC patients carry an increased risk of corneal ectasia. Posterior corneal elevation parameters are sensitive and reliable predictors of keratoconus (KC) risk in AC patients.Clinical Trial Registration:https://clinicaltrials.gov/ct2/show/NCT04299399, identifier [NCT04299399].

Preliminary Study on Siltation in Pussur Navigation Channel with Regulating Structure

In view of the serious problem of siltation rate in Waterway Engineering, feasibility of the scheme is studied from the perspective of sedimentation on Pussur River of Bangladesh in this paper. Based on the analysis of the tide, sediment and topography of the waterway and numerical simulation, the characteristics of the flow movement in the project reach, the influence of the dredging channel on the flow and the siltation were analyzed. With the excavation of channel, due to the influence of dynamic changes and elevation difference, the siltation of the channel is about 0.70–1.79m/a near Inner Bar area, and is more severely in the upper section near Chalna. The implementation of the preliminary regulating structure can increase the velocity and reduce the siltation of the local section. Yet the siltation of the upstream and downstream sections may be added due to changes of flow with the structure. The further scheme should be optimized from the angle of increasing the velocity in channel and reducing the influence to upstream and downstream. The feasibility results can provide scientific basis for the design and construction departments.

Agglomerate Fog Early Warning Method based on GWR Model

In order to realize the early warning of Agglomerate fog-prone sections, reduce accidents and ensure the safety of personal and property. Taking Shandong Province as an example, according to the statistics of the time and location of the roads where the agglomerate fog occurs and the number of occurrences in 2018, the time and space analysis of the agglomerate fog occurrence is carried out, and combined with the analysis of the correlation between the frequent occurrence of agglomerate fog and the elevation of Shandong Province, river density, and Normalized Difference Vegetation Index (NDVI), construction of Geographically Weighted Regression (GWR) model to study the geographical environment conditions of highways prone to foggy weather, the influence of regional altitude, river density analysis and NDVI on the occurrence of agglomerated fog. The research results show that the number of agglomerate fog occurrences in different regions has a strong spatial correlation, that is, the environment of different regions has a greater impact on the number of agglomerate fog occurrences. The agglomerate fog early warning model built with regional river density, elevation difference and NDVI as independent variables can effectively predict agglomerate fog-prone areas. The prediction result shows that more than 98% of the area is within the allowable range of error.

Re-design the use of PV to distribute water from tanks to rural area for Mentawai especially in Central Siberut sub-district

The redesign of the water pump stuck in the district of Central Siberut is reused by using the Solar Panel as an alternative energy source. The materials and tools used are Booster pump, pipe, air valve, wash out, blow off and gate valve. The booster pump is used to pump high pressure water from the tank so that it can reach Saibi village, where Saibi village is the farthest village compared to Simulaklak village, where the distance from the tank to Simulaklak village is only 1.5 km and the tank to Saibi village is 4.5 km the elevation difference between the tank and the village of Saibi is 25 meters above sea level. The total water demand in Simulaklak and Saibi villages is 17.63 liters / second with flow rates in Simulaklak and Saibi villages of 2.25 m / sec and 1.69 m / sec, for the pump head obtained from the tank to Simulaklak village is 72,1 m and the pump head from the tank to Saibi Village is 120.31 m. The standard atmospheric pressure obtained for Simulaklak village is 10,284 mH2O and for Saibi village is 10.301 mH2O. Booster pump is an alternative that can be used for distributing water from the tank to the village.

Improvement Methods for Supply Performance in Emergency Interconnection Plans

When operating a water supply network (WSN), pipe failures and water service interruptions are inevitable. A large-scale water service interruption decreases the reliability of a WSN; therefore, an emergency interconnection plan (EIP) is adopted to prevent it. To establish an EIP involving emergency interconnection pipes, in most cases, only the operation plan is considered. However, it is required to evaluate possible interconnected supply areas (PISAs) from the EIP to achieve the purpose of the EIP. It is obvious that PISA is dependent on the structure of the WSN, elevation difference between the adjacent interconnected blocks, size and location of the emergency interconnection pipes, and inline pumping station. In this study, we categorized the reasons resulting in insufficient PISA from the EIP and suggested improvement methods such as increasing the pipe diameter, new pumping stations, adding emergency interconnection pipes, and adding pressure relief valves. To quantify the effect of the improvement methods on the performance of the EIP, we applied them to a real WSN and estimated the emergency supply rate for each improvement method by using Pressure Driven Analysis (PDA) was used as the hydraulic simulation tool. Consequently, each improvement method increased the PISA and the emergency supply rate on the network. Thus, the suggested method will be used in the design and operation of EIPs to improve their performance.

A Comprehensive Assessment of XGBoost Algorithm for Landslide Susceptibility Mapping in the Upper Basin of Ataturk Dam, Turkey

The success rate in landslide susceptibility mapping efforts increased with the advancements in machine learning algorithms and the availability of geospatial data with high spatial and temporal resolutions. Existing data-driven susceptibility mapping models are not globally applicable due to the high variability of landslide conditioning parameters and the limitations in the availability of up-to-date and accurate data. Among numerous applications, landslide susceptibility maps are essential for site selection and health monitoring of engineering structures, such as dams, for increasing their lifetime and to prevent from disastrous events caused by the damages. In this study, landslide susceptibility mapping performance of XGBoost algorithm was evaluated in a landslide-prone area in the upper basin of Ataturk Dam, which is a prime investment located in the southeast of Turkey. The study area has a size of 2718.7 km2 with an elevation difference of ca. 2000 m and contains 27 lithological units. EU-DEM v1.1 from the Copernicus Programme was used to derive the geomorphological features. High classification accuracy with area under curve value of 0.96 could be obtained from the XGBoost algorithm. According to the results, the main factors controlling the landslides in the study area are the lithology, altitude and topographic wetness index.

Elevation and Volume Changes in Greenland Ice Sheet From 2010 to 2019 Derived From Altimetry Data

Long-term altimetry data are one of the major sources to analyze the change in global ice reserves. This study focuses on the elevation and volume changes in the Greenland ice sheet (GrIS) from 2010 to 2019 derived from altimetry observations. In this study, the methods for determining surface elevation change rates are discussed, and specific strategies are designed. A new elevation difference method is proposed for CryoSat-2 synthetic aperture interferometric (SARin) mode observations. Through validation with Airborne Topographic Mapper (ATM) data, this new method is proved to be effective for slope terrains at the margins of the ice sheet. Meanwhile, a surface fit method is applied for the flat interior of the ice sheet where low resolution mode (LRM) observations are provided. The results of elevation change rates in the GrIS from 2010 to 2019 are eventually calculated by combining CryoSat-2 and ATM observations. An elevation change rate of −11.83 ± 1.14 cm·a−1 is revealed, corresponding to a volume change rate of −200.22 ± 18.26 km3·a−1. The results are compared with the elevation changes determined by Ice, Cloud, and Land Elevation Satellite (ICESat) from 2003 to 2009. Our results show that the overall volume change rate in the GrIS slowed down by approximately 10% during the past decade, and that the main contributor of GrIS ice loss has shifted from the southeast coast to the west margin of the ice sheet.

Fault identification approach and its application for predicting coal and gas outbursts

The formation and development of faults are a manifestation of stress concentrations and energy release in crustal rocks, and faults have a great influence on the occurrence of dynamic mine disasters. This study proposed mapping technology as a fault identification method. The mapping procedure included four steps: (1) Drawing points on topographic maps. The information of topographic maps, such as elevation, rivers, and lakes was copied onto sulfuric acid paper. (2) Classifying the landform. Based on the highest and lowest points in the studied area, the minimum elevation difference was calculated and the elevation points were graded according to the minimum elevation difference. (3) Determining the block boundaries. The elevation points in the same grade were categorized into the same blocks. (4) Mapping the fault distribution. The boundaries between different blocks were considered as faults. In this regard, numbers were assigned to the faults, and a graphic scale, coordinate grid, and legends were added to the map. Fault identification for classes I–V was conducted at different scales. Fault identification for the next class always retained the previous results. Using this method, the faults in the Pingdingshan coal mining zone were divided into classes I–V. By comparing the classes with historical coal and gas outbursts, it was indicated that more than 90% of the coal and gas outbursts occurred in the vicinity of faults, especially at the intersections of multiple faults and in areas with concentrated faults. This study provided a scientific basis for predicting coal and gas outbursts.

Evaluating the Vertical Accuracy of DEM Generated from ZiYuan-3 Stereo Images in Understanding the Tectonic Morphology of the Qianhe Basin, China

Currently available high-resolution digital elevation model (DEM) is not particularly useful to geologists for understanding the long-term changes in fluvial landforms induced by tectonic uplift, although DEMs that are generated from satellite stereo images such as the ZiYuan-3 (ZY3) satellite include characteristics with significant coverage and rapid acquisition. Since an ongoing analysis of fluvial systems is lacking, the ZY3 DEM was generated from block adjustment to describe the mountainous area of the Qianhe Basin that have been induced by tectonic uplift. Moreover, we evaluated the overall elevation difference in ZY3 DEM, Shuttle Radar Topography Mission (1″ × 1″) (SRTM1), and Reflection Radiometer Global Digital Elevation Model (ASTER GDEM) by using the Ice Cloud and Land Elevation Satellite/Geoscience Laser Altimeter (ICESat/GLAH14) point cloud and a DEM of 1:50,000 scale. The values of the root mean square error (RMSE) of the elevation difference for ZY3 DEM were 9.31 and 9.71 m, respectively, and are in good agreement with SRTM1. The river long profiles and terrace heights were also extracted to compare the differences in channel steepness and the incision rates with SRTM1 and ASTER GDEM. Our results prove that ZY3 DEM would be a good alternative to SRTM1 in achieving the 1:50,000 scale for DEM products in China, while ASTER GDEM is unsuitable for extracting river longitudinal profiles. In addition, the northern and southern river incision rates were estimated using the ages and heights of river terraces, demonstrating a range from 0.12–0.45 to 0.10–0.33 m/kyr, respectively. Collectively, these findings suggest that ZY3 DEM is capable of estimating tectonic geomorphological features and has the potential for analyzing the continuous evolutionary response of a landscape to changes in climate and tectonics.