Ground Surface Research Articles

Investigation of groundwater availability and geoelectric analysis to anticipate the scarcity of clean water in urban areas

The need for housing makes suburban areas of Jakarta such as Tangerang Regency, Indonesia, a location that continues to grow. AG Housing is a developer in the area that continues to build housing. In housing development, it is very important to pay attention to the magnitude of water needs, both domestic water needs and non-domestic water needs. A problem that often occurs is that housing developers do not take into account the long-term water needs of their residents, especially in water-scarce areas. Developers often do not check the condition and location of water content in the soil, resulting in water drilling being inefficient and wasteful. The aim of this research is to predict the clean water needs of residents of a housing complex and assess the condition of the water supply below the ground surface using the properties of electric current by flowing DC electric current. The method used in this research is a survey method and geoelectric analysis. This approach involves harnessing the characteristics of electrical current and directing it into the earth. Geoelectric measurements took a sample of 19 Vertical Electrical Sounding (VES) measurement points with North South and East West trajectories in the area. The research results show that there will be an increase in population and an increase in water demand in TA Housing in the next 20 years. Geoelectrical analysis shows the type of soil and rock below the ground surface that will be used as a housing location. Geoelectric testing showed 8 potential points as drilled well locations with a sand layer thickness of between 36.26 m – 62.28 m, while the depth from the ground surface was between 1.01 m – 70.00 m.

Evaluating the Effectiveness of Geotextile and Sub-Drainage in Addressing Road Subsidence on Bumiayu–Sirampog Road, Brebes Regency

Road subsidence commonly occurs in highlands which have poor soil parameters, supported by a lack of proper treatment to prevent subsidence. Common problems are the unequal bearing capacity of the subgrade at each location and variations in settlement caused by the presence of soft soil layers beneath the subgrade. This is why using a geotextile approach is the first step. Like the road subsidence incident located in Sridadi Village, Kec. Sirampog, Kab. Brebes, to be precise at KM 116+100 to KM 116+250, was caused by ground movement which was influenced by a fault from the North East to the South West. Based on the collection and processing of primary and secondary data, the results of the technical evaluation of road repairs on soft soil were obtained, namely treatment with geotextile reinforcement, namely class 1 stabilizer type. Use of 5″ PVC pipe sub-drainage and Ø 1 m Armco to drain water below the ground surface. Through 2D V20 plaxis modeling, the condition of soil stability can be determined before and after the use of geotextiles and sub-drainage at that location. Namely, it can minimize the extreme value of land displacement (Utot) which was originally 5.126 m to 1,414 m. And the reduction value obtained based on field observations was smaller than the laboratory calculation, namely 0.700 m < 0.845 m.

GPR and ERT Exploration in the Western Cemetery in Giza, Egypt

ABSTRACTA geophysical exploration employing ground‐penetrating radar (GPR) and electrical resistivity tomography (ERT) was conducted at the Western Cemetery, Giza, Egypt, in 2021–23 by a joint research team of Higashi Nippon International University, Tohoku University and the National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, Egypt. We believe we found an anomaly: a combination of a shallow structure connected to a deeper structure. The shallow structure, which is L‐shaped in the horizontal plane, 10 m by 10 m, was clearly imaged by GPR. It seems to have been filled with sand, which means it was backfilled after it was constructed. It may have been an entrance to the deeper structure. Its depth is of up to 2 m, measured from the ground surface. Below this structure, ERT reveals a highly electrically resistive anomaly, which extends over an area of about 10 m by 10 m. The depth of the structure is about 5–10 m below the surface. Electrically resistive material in a sand dune can be a mixture of sand and gravel, including sparse spacing or air voids within it. Neither GPR nor ERT could identify the properties of the anomaly.

Magnetic and GPR Data Modelling via Multiscale Methods in San Pietro in Crapolla Abbey, Massa Lubrense (Naples)

ABSTRACTWe performed magnetic and GPR measurements to image the buried ruins of the Middle Age abbey San Pietro in Crapolla, on the Sorrento‐Amalfi Coast (Massa Lubrense, Southern Italy). The site represents an important religious location, which is nowadays partially buried along the cliff. An integrated study was necessary to map the buried structures and address the archaeological excavation. For this reason, we carried out the surveys on two main grids in order to reconstruct the structures of the abbey and of its related church. The magnetic data were filtered through the discrete wavelet transform (DWT) and then transformed to total gradient maps. The obtained maps were interpreted with depth from extreme points (DEXP) imaging method to assess the horizontal and depth positions of the top. The GPR data were processed and time‐depth converted. Results from the integrated interpretation of these data suggest the possible presence of different vaulted rooms and an elongated structure at 0.3‐m depth from ground surface. This latter is interpretable in terms of perimetral and internal walls of the abbey and its church. These outcomes were crucial to successfully address archaeological excavations, which targeted one of the modelled areas and unearthed a wall at the predicted depths.

Effects of two wintering practices on behavioral and physiological indicators of welfare of non-lactating, pregnant dairy cattle in a pasture-based system

In countries with pasture-based dairy systems and relatively cold winters, such as New Zealand, it is common to manage pregnant, nonlactating cows on forage crop paddocks rather than pasture due to slow pasture growth rates. Wintering dairy cattle on grazed crops can compromise welfare if wet and muddy underfoot conditions occur, which can reduce lying. This study investigated behavioral and physiological indicators of welfare of cows under 2 wintering practices: cows managed on and grazed kale crop (Brassica oleracea), and cows managed on pasture with baled hay. Following dry-off (d 0), 80 cows were randomly assigned to one of the 2 wintering practices (40 cows/practice) and monitored between d 4 and d 32 (phase 1). During this period, lying and stepping behavior was continuously recorded using leg-based accelerometers. Blood samples were obtained at d 0 and 32 for measurements of thyroxine (T4), nonesterified fatty acids (NEFA), white blood cells (WBC), and red blood cells (RBC). All data for phase 1 were presented descriptively due to the lack of treatment replication. Daily mean air temperature during this period was 5.2°C (range: 0.0 to 10.7°C), and rainfall was 1.1mm/d (range: 0 to 5.6mm/d). Between d 4 and 32, cows in both groups spent similar amounts of time lying (pasture with hay cows: 8.9h/24h ± 2.57, kale crop cows: 8.7h/24h ± 3.06, mean ± SEM). Both groups reduced their lying on wet and cold days and there was evidence of rebound lying once unfavorable weather conditions stopped. Cows on kale crop had numerically higher NEFA and lower WBC compared with cows managed on pasture, although most physiological values were within normal ranges. In a second phase of the study (d 34 and 35), cows were managed under controlled, replicated conditions in the 2 wintering practices using typical on-farm stocking rates (2 or 4 cows per group in the pasture with hay and kale crop treatments, respectively; n = 10 groups/treatment). During this period, cow behavior, skin and surface temperatures, hygiene scores, feed intakes and ground conditions were measured. Weather conditions during the 48-h exposure were mostly cold and dry (mean air temperature: 7.8°C, range: -2.2 to 20.5°C). Cows managed on pasture with hay spent more time lying down on the first day of exposure, however, this was likely due to less space being available to kale cows on this day. Cows managed on pasture with hay ruminated more than cows on kale crop on both days of observations (Day 1: 37.9% vs 30.9% of observations, Day 2: 36.8% vs 28.7% of observations for pasture with hay and kale crop groups, respectively) and were lying more often in postures indicative of greater thermal comfort. Cows managed on pasture with hay had higher skin and surface temperatures compared with cows on kale crop, whereas cows on kale crop had dirtier coats. Results suggest that opportunities for thermal comfort were greater for cows managed on pasture with hay bales, which may be due to increased rumination activities and more insulated lying areas.

Bayesian Inversion of MDJ Seismograms for Source Parameters and Yields of DPRK Underground Nuclear Explosions 2 to 6

AbstractThe Democratic People’s Republic of Korea (DPRK) conducted six underground nuclear explosions at the Punggye-ri nuclear test site at Mount Mantap, a granite peak. Test 1 was separate from tests 2 to 6, which were within about 1 km of each other. Using seismograms recorded at Mudanjiang (MDJ) seismic station in China, I propose a new approach to obtain source parameters, source time functions and yields of events 2 to 6, assuming they share the same Green’s function from Punggye-ri to MDJ. Each source is modelled as a spherical cavity in a homogeneous isotropic elastic full space, with four independent parameters constrained by published data on the properties of granite and analysis of the recorded MDJ seismograms. The effect of the ground surface is included as a planar reflection that modifies the pressure at the cavity boundary. The Green’s function for each event is estimated by deconvolving the seismogram for the estimated source time function. Very fast simulated annealing (VFSA) is used to search the parameter space to minimise the root-mean square difference among the estimated Green’s functions and their mean. The estimated Green’s functions are similar and differ in amplitude by less than a factor of 2. Green’s functions from Punggye-ri to other seismic stations may be obtained by deconvolving the seismograms for the corresponding source time functions. Mapping the nonlinear zones surrounding each explosion indicates that this part of the site was destroyed by the underground nuclear tests before its official destruction on 24 May 2018.

Behavior of a Laterally Loaded Rigid Finned Pile Located on a Sloping Ground Surface

Behavior of a Laterally Loaded Rigid Finned Pile Located on a Sloping Ground Surface

A framework for automated landslide dating utilizing SAR-Derived Parameters Time-Series, An Enhanced Transformer Model, and Dynamic Thresholding

Determining the timing of landslide occurrence is crucial for establishing an accurate, comprehensive and systematic landslide inventory while assessing the potential for reducing landslide risk. Unfortunately, many existing landslide inventories lack temporal information such as the precise time of landslide events. Optical and Synthetic Aperture Radar (SAR) sensors are the most commonly used remote sensing technologies for landslide detection. Unlike optical sensors, SAR sensors are not affected by cloudy conditions and provide valuable imagery regardless of sunlight availability. Therefore, SAR-derived parameters, i.e., SAR amplitude, interferometric coherence, and polarimetric features (alpha and entropy), offer a higher temporal resolution for detecting landslide occurrence times compared to optical data. Despite the advantages, there is currently no universally accepted automatic method for determining the time of landslide events using SAR data. This is due to the lack of anomaly labels and the high time-series volatility in detecting landslide occurrence times. Despite advances in deep-learning methods for anomaly detection in time-series, only a few of them can address these challenges in our case. In this paper, we propose an unsupervised multivariate transformed-based deep-learning model to automatically and efficiently estimate landslide occurrence times using multivariate SAR-derived parameters time-series analysis. The designed gated relative position can increase robustness and temporal context information, by learning global temporal trends in the time-series. Subsequently, the time-series of the anomaly score derived from the proposed Transformer model is analyzed using an adaptive thresholding strategy to dynamically and automatically mark anomalies related to the landslide occurrence. Our research focuses on collapsed landslides characterized by dramatic changes in ground surface topography, with a particular attention for the need of a prior knowledge about landslide boundaries. We assess the performance of the proposed methodology for several collapsed landslides including the July 21, 2020 Shaziba and 23 July, 2019 Shuicheng landslides in China, March 19, 2019 Takht landslide in Iran, June 15, 2018 Jalgyz-Jangak and May 25, 2018 Kugart landslides in Kyrgyzstan, July 7, 2018 Hitardalur landslide in Iceland, and January 25, 2019 Brumadinho landslide in Brazil. In comparison to commonly used neural networks like the LSTM algorithm, our proposed framework leads to a more accurate estimate for the time of landslide failure using time-series of SAR-derived parameters. Furthermore, our results suggest the great potential of SAR data to narrow the time period detected from optical data when used in conjunction with them.

Using Vehicle‐Induced DAS Signals for Near‐Surface Characterization With High Spatiotemporal Resolution

AbstractVehicle‐induced seismic waves, generated as vehicles traverse the ground surface, carry valuable information for imaging the underlying near‐surface structure. These waves propagate differently in the subsurface depending on soil properties at various spatial locations. By leveraging wave propagation characteristics, such as surface‐wave velocity and attenuation, this study presents a novel method for near‐surface monitoring. Our method employs passing vehicles as active, non‐dedicated seismic sources and leverages pre‐existing telecommunication fibers as large‐scale and cost‐effective roadside sensors empowered by Distributed Acoustic Sensing (DAS) technology. A specialized Kalman filter algorithm is integrated for automated DAS‐based traffic monitoring to accurately determine vehicles' location and speed. Then, our approach uniquely leverages vehicle trajectories to isolate space‐time windows containing high‐quality surface waves. With known vehicle (i.e., seismic source) locations, we can effectively mitigate artifacts associated with suboptimal distribution of sources in conventional ambient noise interferometry. Compared to ambient noise interferometry, our approach enables the synthesis of virtual shot gathers with a high signal‐to‐noise ratio and spatiotemporal resolution at reduced computational costs. We validate the effectiveness of our method using the Stanford DAS‐2 array, with a focus on capturing spatial heterogeneity and monitoring temporal variations in soil seismic properties during rainfall events. Specifically, in non‐built‐up areas, we observed an evident decrease in phase velocity and group velocity and an increase in attenuation due to the rainfall. Our findings illustrate our method's sensitivity and resolution in discerning variations across different spatial locations and demonstrate that our method is a promising advancement for high‐resolution near‐surface imaging in urban settings.

Hydrogeological Assessment of the Aquifers in Shwan Sub-Basin, Kirkuk, Iraq

Groundwater is considered one of the main sources of providing water for agricultural, domestic, and industrial activities within the Kirkuk province. The current article aims to assess the groundwater impound and estimate the hydraulic properties of the main aquifers within the Shwan sub-basin. Pumping test was conducted in 6 water wells with the aid of the principal observation wells drilled in the Bai-Hassan formation and Quaternary deposit. Based on the sketches of the drilling wells and according to the results of the hydraulic characteristics the aquifer types lie under the confined to semi-confined conditions. The saturation thickness varies between 35–82 m. The values of hydraulic conductivity ranged between 12–28 m/d the Transitivity is in the range of 570 m2/d–1032 m2/day, and the storage coefficient ranged between 3 x 10-4 – 9 x 10-4. The flow net map was created by measuring the depths of the groundwater from 55 wells drilled inside the area of interest. The depths to the water table range from 7.5 –108 m below the ground surface and the static water level varies from 235–750 m a.s.l. The groundwater flow map shows that the water in the area heads mainly from the eastern towards the western direction, then drains to the Lesser Zab River.

Urban microclimate differences in continental zone of China

In modern cities, the block geometry and land cover feature directly affect the heat transfer between ground surface and atmosphere, resulting in significant differences of local microclimate. Clarifying this difference will help to accurately predict regional building energy demand and optimize regional layout design. However, existing microclimate research mainly focuses on tropical, arid, and temperate climate regions, leaving continental areas virtually unexplored. To address this problem and clarify the interactions of the urban blocks and microclimate, the combination of the local climate zone (LCZ) scheme and fixed-point weather station monitoring is employed to investigate the variation characteristics of the thermal and humidity conditions of typical urban blocks in continental zone of China. Firstly, sixty-seven typical urban blocks with self-built, national and regional meteorological stations are selected as the object of study, and classified into twelve LCZ categories, according to their inherent features. Secondly, the spatial and temporal variation patterns of the thermal environment indexes of the twelve LCZ types are analyzed and compared. Additionally, correlation analyses and regression fittings are performed between the thermal environment indexes and the urban morphological parameters. The results indicate significant differences in thermal environment indexes among different LCZ types. The mean temperature of built types is 0.72 °C higher than land cover types. The temperature and humidity exhibit a parabolic relationship with height of roughness elements and building surface fraction respectively, while the humidity has strong negatively correlations with the impervious surface fraction and the height of roughness elements.

Amphibious Robots Locomotion Strategies in Unstructured Complex Environments: A Review

In the previous literature, amphibious robots focused mainly on locomotion in underwater and flat land surface manoeuvring. Few amphibious robots focused on unstructured land environments. The amphibious robot designs were more emphasised in academics, leading to more work done in building amphibious robots that mimic biological amphibians, imitating the geometry and overall functionality of the amphibious robots. Developing amphibious robots with propulsive mechanisms for manoeuvring in a water environment received more attention than other functionalities like adaptability on rough natural terrain and obstacle repositioning capability. However, practical applications like reconnaissance and surveying posed challenges in the ground environment, which had unstructured and complex terrain profiles, especially in the transition area. Therefore, reviewing the amphibious robots focused on manoeuvring complex uneven surfaces was essential. The literature had comprehensive review papers on navigation strategies encompassing manoeuvring on flat ground surfaces and underwater locomotion. There was a need for a focused study that highlighted the amphibious robot that manoeuvred in an unstructured land environment. The open challenges and recent solutions by designing new mechanisms and deployment issues were highlighted and reviewed. Hence, the paper addressed a more specific review of amphibious robot locomotion in an unstructured environment. The paper also discussed a case study of an amphibious robot capable of locomotion in unstructured environments. It was envisaged that the review would provide directions and insights to researchers and robotic system designers on developing robust propulsive mechanisms for amphibious robots capable of locomotion in unstructured environments.Keywords: manoeuvrability, mobility, terrain, unified locomotion, mechanism, propulsion

A new method of ship detection in complex background of SAR images based on YOLO

Synthetic Aperture Radar (SAR) is a remote sensing technology capable of high-resolution imaging of the ground surface under any weather and light conditions. SAR image ship detection is a technique that uses the ship target features in SAR images to identify and locate ships, which is of great value for applications in the fields of maritime traffic management, marine environment monitoring, and maritime security and defence. However, SAR image ship detection also faces some challenges, such as complex sea surface background, low signal-to-noise ratio, and the diversity and density of ship targets, which lead to the shortcomings of traditional feature extraction and classifier-based detection methods in terms of accuracy and efficiency. To address these challenges, this paper proposes a new method for ship detection in SAR images based on YOLOv7. When dealing with SAR images containing clutter interference and complex backgrounds, many models face the dual challenge of insufficient real-time and accuracy. To address this problem, this study proposes a new PCAN aggregation network, which firstly introduces the SimAM attention mechanism, which significantly enhances the model's ability to identify the differences between ships and background clutter, further improves the ability of focusing on target features, and effectively It further improves the ability to focus on target features, effectively reduces the interference of background noise, and improves the detection accuracy in complex scenes. At the same time, the PConv strategy is added to further lighten the model structure, thus accelerating the computation process and improving the inference efficiency. We trained and tested the model on the SAR-Ship-Dataset dataset, and achieved an accuracy of 91.1%, an F1 score of 92.9, and an FPS of 46, demonstrating its excellent detection capability. By comparing and analysing the model with several classical and cutting-edge methods in the current field, the proposed model in this study demonstrates obvious performance advantages, and in addition, through ablation experiments, we further confirm the effectiveness and contribution of PCAN.

Rain gardens enhance the taxonomic richness but not the abundance of soil invertebrates in urban ecosystems

Natural treatment systems such as rain gardens aim to overcome the negative effects of urban stormwater, preventing harm to human population and infrastructure. Rain gardens house an abundance of soil fauna comprising a functionally important group of organisms. However, the responses of different groups of soil fauna to rain gardens remain poorly explored. In this study, we investigated the abundance, taxonomic richness, taxonomic diversity, and community composition of ground-dwelling and belowground invertebrates in rain gardens and nearby lawns in Nanjing and Zhenjiang cities, China. In Nanjing, we found that the taxonomic richness of ground-dwelling and belowground invertebrates was significantly higher in rain gardens than in lawns. We also discovered that the community composition of ground-dwelling invertebrates differed significantly between rain gardens and lawns, a distinction primarily explained by gravel coverage. However, in Zhenjiang, there were no significant differences in the abundance, taxonomic richness, taxonomic diversity, or community composition of ground-dwelling and belowground invertebrates between rain gardens and lawns. These results indicate that the effects of rain gardens on soil faunal community structure varied with soil fauna groups and cities. Considering that soil fauna have positive effects on the function of rain gardens such as water infiltration and decomposition, we suggest that the addition of ground surface mulch such as gravel may enhance soil biodiversity.

Influence of synchronous grouting on surrounding sandy cobbles during shield tunnelling process: Insights from a scaled model test

Substantial soil deformation around tail-grouting activity is frequently observed during the shield tunnelling process in the sandy cobble strata, which is attributed to the convergence and potential collapse of the soils around the tail-void left behind the shield machine. The stability of the underlying strata is significantly impacted by synchronous grouting inside the tail-void. This study examines four-opening synchronous grouting, which is frequently used in shield tunnelling of metro-tunnels, to analyze the grout-spreading mechanism and soil displacement generated by the synchronous grouting in the sandy cobble layer. Laboratory tests are used to determine the characteristics of grouting mortar and soils in accordance with the similarity theory. The model experiment outcomes show that a rise in the GVR (Grouting-Volume Ratio) can cause the settlement at the ground surface. However, as the GVR improves, the pace of settlement growth diminishes. Additionally, the expanding cover depth of the tunnel contributes to the stability of the soil after synchronous grouting. As observed in the model test, when GVR achieves its maximum amplitude (i.e., GVR = 200 %), the grout mortar cannot spread to the crown of the tail-void, necessitating secondary grouting after the synchronous grouting during tunnelling practice. After grout hardening process, it was discovered that grout material above the tunnel waist was concentrated near the upper grout openings, implying a seepage spreading mode of the grout-mortar at these locations. In contrast, grout material below the tunnel waist was evenly distributed along the periphery of the tail void. The model test outcomes may be utilized as a guide for tail-grouting while shield tunneling in sandy cobble strata.

Geotechnical and structural assessment on estimated bearing capacity of strip footing resting on silty sand incorporating moisture content effect

This paper aims to assess the ultimate bearing capacity of a strip footing on the ground surface of a silty sand soil layer. It considers structural failures and geotechnical changes, including the impact of moisture content, using numerical simulation in PLAXIS 3D V21. The structural damage assessments on a student center building located in the northern part of Peninsular Malaysia were performed by visual inspection, and thirty-six sub-points of rebound hammer tests were conducted on three selected different points (Point 1, 2, 3) of the building to evaluate concrete strength and record crack characteristics for severity classification. Subsequently, an extensive geotechnical laboratory tests were performed to investigate the effects of moisture content on physical and mechanical properties of silty sand including, soil compositions, Atterberg limits, compaction characteristics and unconfined compressive strength (UCS) from the building area which resulted to structural damage caused by differential settlement beneath the building. The visual inspection assessment has shown the student center building experienced severe damage category at Point 1 with crack width and length are 25 mm and 3 m respectively. At Point 2, there was minimal damage to the surface structure, with a crack measuring 1 mm in diameter and 0.1 m in length. Furthermore, crack width and length are 1 mm and 0.2 m respectively are recorded for Point 3. The study fills in a gap in the research by combining geotechnical and structural tests on the bearing capacity of silty sand with moisture content. The effect of soil saturation, matric suction, and the unsaturated strength of soil are affected by these factors in the analysis of the bearing capacity of the foundation. The exact solution gives us 568.213 kPa for a zero degree of saturation and 385.34 kPa for a 100 percent degree of saturation. The incorporation of geotechnical and structural assessments aims to find reliable strategies for failure remediations for instance patched and sealed with a concrete patching compound.

Assessment of the effect of moisture on the strength of concrete and ceramic masonry wall products

Introduction. The material of the article considers the strength characteristics of ceramic and concrete masonry products, the operation of which is carried out in difficult conditions. The analysis of domestic and foreign publications and sources carried out in this work, including the results of previously performed experiments and field studies, showed that the values of the tensile strength of concrete and ceramic masonry products largely depend on moisture saturation.&#x0D; &#x0D; Aim. When analyzing previously performed works, it was found that moisture saturation and operating conditions significantly affect the strength properties of concrete and ceramic masonry products in the form of bricks and small blocks. It is noted that in some cases, the effect of degradation of the physical and mechanical properties of the products was observed. When performing surveys of buildings and structures, it becomes necessary to determine the bearing capacity of the masonry of foundations and basement walls located below the mark of the adjacent ground surface. These structures are located in an environment of excessive humidity, therefore, the masonry products themselves are in a state of increased moisture saturation, for example, due to the absence or damage of waterproofing, violation of the heat and humidity regime of the indoor microclimate.&#x0D; &#x0D; Materials and methods. During the work, masonry ceramic products in the form of bricks were used – new ones made according to State Standard 530-2012; historical bricks selected during the inspection of buildings and structures of historical buildings, as well as concrete wall products made according to State Standard 6133-2019. The test procedure complies with the established standard State Standard R 58527-2019.&#x0D; &#x0D; Results. Conducting of the research and developing of methods to assess the effect of humidification of ceramic and concrete masonry products on the strength of masonry is important for assessing the reliability of buildings and structures.&#x0D; &#x0D; Conclusions. The current problem requires comprehensive studies of the strength characteristics of ceramic and concrete masonry wall products, taking into account the influence of humidity.

A NEW ABRASIVE DISC DESIGNED FOR GRINDING GRANITE

The aim of the work is to develop a new effective design and material of the disc for abrasive machining of granite. The task was undertaken in order to shorten the time of the machining operation of surface grinding by ensuring a uniform post-machining surface roughness for a given cycle , shortening the time for a given grain group of abrasive segments. For the purpose of the task, an analysis of the effectiveness of the impact of the working surface of the disc of known geometric solutions and a new solution of the disc geometry was carried out. Recipes for material composition and technology for making prototypes of discs with a new geometry of abrasive segments were developed, for which laboratory tests were performed.

Implementation of hybrid CryoMQL sustainable lubri-cooling to enhance the grindability and surface integrity of tool steel

The current demand for surface finishing processes that are both technically proficient and environmentally friendly is increasing, necessitating the advancement of more efficient sustainable methods. Minimum quantity lubrication (MQL) provides excellent lubrication in the tool-work interaction but insufficient cooling impact. Besides, cryogenic enhances the chilling effect but has inadequate lubrication. This research revealed the synergistic impact of hybrid CryoMQL with eco-friendly Al2O3 NFs while grinding AISI D2 tool steel. CryoMQL facilitates the application of MQL-based soybean oil and deionized water (SO+DW) emulsion with 0.5 wt% and 1 wt% concentration of Al2O3 NPs and liquid nitrogen (LN2) through two individual nozzles in the cutting region. The results indicated that CryoMQL reduced grinding force (tangential force, Ft, and normal force, Fn), specific grinding energy (Ug), surface roughness (Ra), and grinding temperature (Tg) by 3.64–25.66 % in Ft, 3.52–12.87 % in Fn, 3.64–25.66 % in Ug, 8.81–25.02 % in Ra and 57.59–58.30 % in Tg, respectively, compared to MQL environment at 0.04 mm downfeed and 150 mm/s table feed rate. Eventually, it was observed that 1 wt% Al2O3 NFs improve Ft, Fn, Ug, Ra and Tg by up to 32.71 %, 20.33 %, 32.71 %, 23.55 %, and 6.81 % in comparison to 0.5 wt% Al2O3 NFs in the CryoMQL mode. The effectiveness of Al2O3 nanofluids with CryoMQL has resulted in good tribological conditions in the grinding zone with enhanced cooling/lubricating action of vegetable oil. Furthermore, negligible chip adhesion over finished surfaces was seen with 0.5 wt% and 1 wt% Al2O3 NFs under CryoMQL grinding. This study provides numerous scientific assistance in the automotive and tooling sectors, such as a better selection of environmentally friendly coolants and sustainable parameters for excellent surface properties, to provide the solution to highly complex and close tolerances of tool steel parts using CryoMQL finishing.

Cooling Performance of a Novel Ventilated Slope on Railbed in Permafrost Regions

ABSTRACTThe heat absorption of the railbed mainly originates from the embankment slope in permafrost regions. A novel ventilated slope (NVS) with a double‐layer convection channel is proposed and verified. By applying this method to the Qinghai–Tibet Railway (QTR), the annual average temperature at the 10 cm depth below the embankment slope surface under NVS was reduced by 4.95°C. The freezing index at the 10 cm depth of NVS was 1.78 times higher than that of the slope without any cooling approaches. The numerical simulation results showed that heat was accumulated for the conventional embankment, while heat was released from the railbed after the application of NVS. With the cooling effect of NVS, the 0°C isotherm would rise above the original natural ground surface in the 2nd year after the embankment construction. A low‐temperature region of −2°C would be observed in the underlying permafrost by the 10th year. The underlying permafrost would remain frozen in the 50th year. This study provides a novel method for protecting the underlying permafrost in permafrost regions.