Adaptive Robust Servo Control for Vertical Electric Stabilization System of Tank and Experimental Validation

A tracking stability control problem for the vertical electric stabilization system of moving tank based on adaptive robust servo control is addressed.This paper mainly focuses on two types of possibly fast timevarying but bounded uncertainty within the vertical electric stabilization system:model parameter uncertainty and uncertain nonlinearity.First,the vertical electric stabilization system is constructed as an uncertain nonlinear dynamic system that can reflect the practical mechanics transfer process of the system.Second,the dynamical equation in the form of state space is established by designing the angular tracking error.Third,the comprehensive parameter of system uncertainty is designed to estimate the most conservative effects of uncertainty.Finally,an adaptive robust servo control which can effectively handle the combined effects of complex nonlinearity and uncertainty is proposed.The feasibility of the proposed control strategy under the practical physical condition is validated through the tests on the experimental platform.This paper pioneers the introduction of the internal nonlinearity and uncertainty of the vertical electric stabilization system into the settlement of the tracking stability control problem,and validates the advanced servo control strategy through experiment for the first time.

Hydrogeophysical and Structural Investigations Using VES: A Case Study of Dosso Region in the Southwestern Part of the Meso-Cenozoic Iullemmeden Basin (Southwestern Niger)

A regional study connecting geolelectrical surveys with geology and hydrogeology was carried out in the western part of the Iullemmeden basin, precisely in the Dosso region in Niger. One hundred and four (104) vertical electrical sounds have been realized, among them nineteen representative were thus be used as parametric surveys. The local resistivity values of the geological formations of Quaternary range from 100 Ω⋅m to 1000 Ω⋅m (sands and lateritic sandstones). The Oligo-Miocene formation of the Continental terminal (Ct) shows resistivity values ranging from 1 to 5 Ω⋅m (brackish groundwaters) to 1500 Ω⋅m (clay sandstones) while the Upper Cretaceous formation of the Continental “hamadien” (Ch) indicates values ranging from 20 Ω⋅m (sandy clay) to 5000 Ω⋅m (clayey sandstones). The geological formations of Paleocene have values from 2 Ω⋅m (marls) to 60 Ω⋅m (calcareous marl), while the Precambrian basement exhibits values of granite around 300 Ω⋅m to 60,000 Ω⋅m. The update of the structural settings reveals many faults in the study area which explain both the shape of the basin and the geometry of the aquifers. Tectonics is also consistent with the hydraulic characteristics of aquifers. In addition, brackish groundwaters were identified as perched aquifer groundwaters in different depths in Dosso region. They probably come from the marine brines during the regression of the Paleocene Sea.

An analytical model for the vertical electric field distribution and optimization of high voltage REBULF LDMOS

In this paper, an analytical model for the vertical electric field distribution and optimization of a high voltage-reduced bulk field（REBULF） lateral double-diffused metal–oxide-semiconductor（LDMOS） transistor is presented. The dependences of the breakdown voltage on the buried n-layer depth, thickness, and doping concentration are discussed in detail.The REBULF criterion and the optimal vertical electric field distribution condition are derived on the basis of the optimization of the electric field distribution. The breakdown voltage of the REBULF LDMOS transistor is always higher than that of a single reduced surface field（RESURF） LDMOS transistor, and both analytical and numerical results show that it is better to make a thick n-layer buried deep into the p-substrate.

Evolution of Vertical Electric Currents and Flares in An Active Region

In this paper, solar active region (AR) 6891 is studied. The long term temporal (over a 8 day period) relationahip between vertical current evolution and flare are examined. We found that the day to day variation of the flare number in the active region is more closly associated with the variation of net current intensity than that of total current intensity. The increase in negative current in the weak following polarity area is due to the reduction in negative current in the strong preceding area.

Characterization of Subsurface Lithology and Aquifer Parameters Using Vertical Electrical Sounding(VES)for Groundwater Development in Igbo-Imabana,Southern Nigeria

Vertical Electrical Soundings(VES)using Schlumberger array was carried out at fifteen(15)different points to evaluate aquifer characteristics within Igbo-Imabana,Abi L.G.A of Cross River State.Resistivity meter and its accessories were used for data acquisition.The maximum current and potential electrode distance were 400 m and 20 m respectively.The field data were interpreted using Interpex software and three to five geo-electric layers encountered within the study area.The dominant curve type was H followed by K.From the result,geo-electric layers delineated were sandstone,clay,saturated sandstone,sandy shale,clayey shale,and shale with average apparent resistivity values of 2249.94Ωm,2.86Ωm,365.28Ωm,222.69Ωm,14.60Ωm and 59.02Ωm respectively.The top geoelectric layer was dominantly lateritic topsoil,with variation in degrees of compaction and having an average resistivity of 876.33Ωm with depth and thickness generally less than 5 m.The calculated aquifer parameters hydraulic conductivity(K_(c)),transmissivity,longitudinal conductance,and transverse resistance from the VES results show ranges values;3.86×10^(-4)to 4.69×10^(-2)m/day,2.95×10^(-3)to 2.82 m^(2)/day,2.95×10^(-3)to 2.81Ωm and 484.33 to 19444.83Ω^(2)m respectively.The aquifer thickness and depth values range from 3.60 m to 68.05 m and 5.20 m to 76 m respectively.The study reviewed that the area is made of heterolithic/heterogenous lithofacies,confined aquifer(s),shallow and deep aquifer.Also,from the models and aquifer parameters,the area is characterized by semipervious materials.This integrally explains why the area have have low transmissivity and majority of boreholes drilled in the area failed.

Estimating aquifer transmissivity using Dar-Zarrouk parameters to delineate groundwater potential zones in Alluri Seetharama Raju District,Andhra Pradesh, India

This study aimed to explore groundwater potential zones in the EGMB of Alluri Seetharama Raju district, Andhra Pradesh, India, for drinking and agriculture purposes. To achieve this goal, 72 Vertical Electrical Soundings(VES) were conducted using the Schlumberger electrode configuration. The resistivity sounding data were analyzed to determine the aquifer thickness, basement depth, Dar-Zarrouk parameters,and aquifer transmissivity. Spatial distribution maps were generated for these parameters to understand the subsurface formation. The analysis revealed a linear groundwater potential zone(8.46 km~2) in the eastern part of the study area, extending in the NNE-SSW direction for 9.6 km. Six VES locations(P24, P27, P29,P30, P33, and P38) in this zone exhibit good potential(>30 m aquifer thickness), while the three VES locations(OP19, P5, and P46) in the central region are recommended for drilling bore wells. Additionally,moderate aquifer thickness(20–30 m) are identified in other VES locations(OP14, OP20, P4, P10, P12,P13, P15, P17, P18, P31, P46, and P50) along streams in the western and central part of the area, which can yield reasonable quantities of water. This information is useful for groundwater exploration and watershed management to meet the demands of tribal population in the study area.

Electrical geophysical evaluation of susceptibility to flooding in University of Nigeria, Nsukka main campus and its environs, Southeastern Nigeria

Flooding occurs when rainfall exceeds the absorption capacity of soil and causes significant environmental consequences.In this study,electrical resistivity techniques were employed to assess the flood susceptibility of the study area by examining variations in electrical properties.Prior to flooding,Vertical Electrical Sounding(VES)and Electrical Resistivity Tomography(ERT)profiles were conducted to determine the variations in resistivity within subsurface lithologies exposed to the injected current.The injected current penetrated the subsurface units characterised by resistivity ranging from 190.5Ω·m to 6,775.7Ω·m,42.3Ω·m to 7,297.4Ω·m,and 320.2Ω·m to 24,433.3Ω·m in the first,second and third layers,respectively.These layers were identified as lateritic topsoil,medium-coarse brownish grained sand,and coarse pebbly blackish sand,respectively.The calculated reflection coefficients between layers 1,2,and 3 reveal alternation in layers with values ranging from−0.04 to 0.66 and 0.36 to 0.95 for and,respectively.The transverse resistivity,longitudinal resistivity and anisotropy ranged from 243.59Ω·m to 24,115.42Ω·m,199.61Ω·m to 14,950.76Ω·m,and 1.02 to 2.14.Models derived from the ERT profiles reveal variations in resistivity,pinpointing areas of low resistivity which correspond to waterlogged and impermeable layers.The result of this study underscores the importance of integrated resistivity techniques in the study of floods,as it provides valuable insights into flood behaviour,and subsurface dynamics.

Groundwater Potential Mapping in Lapan Gwari Community Using Integrated Remote Sensing and Electrical Resistivity Soundings

This research aims to address the pressing issue of failed and abandoned wells, causing water scarcity in Lapan Gwari Community, through an improved groundwater exploration approach integrating remote sensing and electrical resistivity soundings. The study area, located within the Zungeru Sheet 163 SE, spans Latitudes 9°30'00"N to 9°32'00"N and Longitudes 6°28'00" to 6°30'00". The surface geologic, structural, and hydrogeological mapping provided essential insights into the hydrogeological framework. Leveraging SRTM DEM data, thematic maps were created for geomorphology, slope, land use, lineament density, and drainage density. These datasets were then integrated using ArcGIS to develop a preliminary groundwater potential zones map. Further investigations were conducted using Vertical Electrical Sounding (VES) and Electrical Resistivity Imaging (2D VES) surveys at targeted locations identified by the preliminary map. Results show that the study area predominantly consists of crystalline rocks of the Nigerian Basement Complex, primarily comprising schist and granite with minor occurrences of quartz vein intrusions. Surface joint directions indicated a dominant NE-SW trend. The VES data revealed three to four geoelectric layers, encompassing the topsoil (1 to 5 m depth, resistivity: 100 Ωm to 300 Ωm), the weathered layer (in the 3-layer system) or fractured layer (in the 4-layer system), and the fresh basement rock characterized by infinite resistivity. The shallow weathered layers (3 to 30 m thickness) are believed to hold aquiferous potential. Hydrogeological interpretation, facilitated by 2D resistivity models, delineated water horizons trapped within clayey sand and weathered/fractured formations. Notably, the aquifer resistivity range was found to be between 3 - 35 m and 100 - 300 Ωm, signifying a promising aquifer positioned at depths of 40 to 88 m. This aligns with corroborative static water level measurements. Given this, we recommend drilling depths of a minimum of 80 m to ensure the acquisition of sufficient and sustainable water supplies. The final groundwater potential zones map derived from this study is expected to serve as an invaluable guide for prospective groundwater developers and relevant authorities in formulating effective water resource management plans. By effectively tackling water scarcity challenges in Lapan Gwari Community, this integrated approach demonstrates its potential for application in similar regions facing comparable hydrogeological concerns.

Dar Zarrouk Parameter as a Tool for Evaluation of Well Locations in Afikpo and Ohaozara, Southeastern Nigeria

The inhabitants of this area depend solely on contact springs as supply source of potable water. However, provision of potable water to meet the needs of the people still remains an unsolved problem. Therefore, this paper attempts to solve this problem by using Dar Zarrouk (D-Z) Parameters;Total Transverse Unit Resistance, T (Ωm2) and Total Longitudinal Unit Conductance, S (Ω-1) to suggest optimal locations for drilling of boreholes in the study area. To attain this purpose, 50 Schlumberger Vertical Electrical Sounding (VES) curves with maximum current electrode spacing of AB/2 = 681 m were interpreted. Thus, the aquifer parameters information estimated from the (VES) curves were used to prepare contour maps of T (Ωm2), S (Ω-1), aquifer thickness h (m), aquifer resistivity ρ (Ωm), and Water Table Depth (WTD). For effective use of these parameters, iso-thickness and iso-resistivity maps were compared with contour map of transverse resistance. The good agreement between these parameters provided the basis for identification of prolific aquiferous zones. It was observed that the Southern part of the study area majorly underlain by the Afikpo Sandstone of Nkporo Formation (Campanian-Maastrichtian), relatively showed higher T (Ωm2), h (m), and ρ (Ωm) values, which implies high yield aquiferous zones. The relatively loose structure of this sandstone unit, coarse grains, and sorting enables it to be porous and permeable. The Northern part of the region which shows low values for T (Ωm2), h (m), and ρ (Ωm) suggests low productivity for the aquiferous zones. The paucity of water in this parts of the study area can be explained to be as a result of the dominant geology. The high S, values at the Uburu and Okposi locations in this region suggests the presence of saline aquifer. This study would be relevant to the development of effective ground water scheme and for future hydrogeological investigations in the area.

A compact two-dimensional analytical model of the electrical characteristics of a triple-material double-gate tunneling FET structure

This paper presents a compact two-dimensional analytical device model of surface potential,in addition to electric field of triple-material double-gate(TMDG)tunnel FET.The TMDG TFET device model is developed using a parabolic approximation method in the channel depletion space and a boundary state of affairs across the drain and source.The TMDG TFET device is used to analyze the electrical performance of the TMDG structure in terms of changes in potential voltage,lateral and vertical electric field.Because the TMDG TFET has a simple compact structure,the surface potential is computationally efficient and,therefore,may be utilized to analyze and characterize the gate-controlled devices.Furthermore,using Kane's model,the current across the drain can be modeled.The graph results achieved from this device model are close to the data collected from the technology computer aided design(TCAD)simulation.

Electrical Resistivity Sounding for Groundwater Investigation around Enugu Metropolis and the Environs, Southeast Nigeria

This report evaluates the use of electrical method and borehole data to investigate the subsurface to delineate the groundwater potential in Enugu metropolis and the environs, south-eastern Nigeria other than rely only on resistivity method which could lead to interpretation error. Integrating these 2 data sets is key in this study. The study area is located in the Anambra Basin and is underlain by Nkporo/Enugu Shale which is overlain by the Mamu Formation. It is bounded by Latitudes 6°2 0'00"N to 6°30'00"N and Longitudes 7°25'00"E to 7°35'00"E and covers surface area of about 342 m2. Thirty-one vertical electrical soundings (VES) were carried out across the area using the Schlumberger electrode array with current electrode separation from 2 to 500 m to identify the depths and resistivity values of the identified geo-electric layers. Through data analysis using WinResist software, the apparent resistivity, thicknesses and depths and the thicknesses of the aquifers were generated. The resistivity and depths were modelled to generate resistivity map and depth map. The resistivity of the aquiferous zone within the study area varied from 20.55 - 427.8 ohm-m at depths of between 10.7 - 40.05 m. Depth to the water table appears to be shallow at the south western part of the map. The interpreted geo-electric layers show a sequence of lateritic top soil, shale, sand and shale. The frequency distribution of the VES curves generated shows the presence of 3 to 5 layers with HK type as the highest. Also, a 2D model was generated using the correlation of VES to VES data and borehole data to VES data to show the underlying stratigraphy beneath the study area as well as the direction of ground water flow. Result of the VES curve analysis reveals that the sub-surface is underlain by three lithological layers namely: lateritic top soil, shale, sand and shales with NW direction of groundwater flow from the 2D model. Groundwater prospective zones can be seen along NW, SW and central parts of the study area which have low resistivity values.

Prognostics for Lithium-ion batteries for electric Vertical Take-off andLanding aircraft using data-driven machine learning

The health management of batteries is a key enabler for the adoption of Electric Vertical Take-off and Landingvehicles (eVTOLs). Currently, few studies consider the health management of eVTOL batteries. One distinctcharacteristic of batteries for eVTOLs is that the discharge rates are significantly larger during take-off andlanding, compared with the battery discharge rates needed for automotives. Such discharge protocols areexpected to impact the long-run health of batteries. This paper proposes a data-driven machine learningframework to estimate the state-of-health and remaining-useful-lifetime of eVTOL batteries under varying flightconditions and taking into account the entire flight profile of the eVTOLs. Three main features are consideredfor the assessment of the health of the batteries: charge, discharge and temperature. The importance of thesefeatures is also quantified. Considering battery charging before flight, a selection of missions for state-ofhealth and remaining-useful-lifetime prediction is performed. The results show that indeed, discharge-relatedfeatures have the highest importance when predicting battery state-of-health and remaining-useful-lifetime.Using several machine learning algorithms, it is shown that the battery state-of-health and remaining-useful-lifeare well estimated using Random Forest regression and Extreme Gradient Boosting, respectively.

Overall eVTOL aircraft design for urban air mobility

Electric vertical takeoff and landing(eVTOL)aircraft have emerged as a potential alternative to the existing transportation system,offering a transition from two-dimensional commuting and logistics to three-dimensional mobility.As a groundbreaking innovation in both the automotive and aviation sectors,eVTOL holds significant promise but also presents notable challenges.This paper aims to address the overall aircraft design(OAD)approach specifically tailored for eVTOL in the context of Urban Air Mobility(UAM).In contrast to traditional OAD methods,this study introduces and integrates disciplinary methodologies specifically catered to eVTOL aircraft design.A case study is conducted on a tilt-duct eVTOL aircraft with a typical UAM mission,and the disciplinary performance,including initial sizing,aerodynamics,electric propulsion systems,stability and control,weight,mission analysis and noise,is examined using the OAD methodologies.The findings demonstrate that the current approach effectively evaluates the fundamental aircraft-level performance of eVTOL,albeit further high-fidelity disciplinary analysis and optimization methods are required for future MDO-based eVTOL overall aircraft design.

Effects of vertical electric field and compressive strain on electronic properties of bilayer ZrS2

Using first-principles calculations,including Grimme D2 method for van der Waals interactions,we investigate the tuning electronic properties of bilayer zirconium disulfides（ZrS_2/ subjected to vertical electric field and normal compressive strain.The band gap of ZrS_2 bilayer can be flexibly tuned by vertical external electric field.Due to the Stark effect,at critical electric fields about 1.4 V/？,semiconducting-metallic transition presents.In addition,our results also demonstrated that the compressive strain has an important impact on the electronic properties of ZrS_2 bilayer sheet.The widely tunable band gaps confirm possibilities for its applications in electronics and optoelectronics.

Geoelectrical Investigation of Groundwater Potentials of Northern Paiko,Niger State,North Central Nigeria

Vertical electrical sounding（VES） was carried out in northern part of Paiko, North Central Nigeria, using Abem terrameter model SAS 4000 to determine the subsurface layer parameters（resistivities, depths and thickness） employed in delineating the groundwater potential of the area. A total of six transverses with ten VES stations along each traverse, at intervals of 50 m were investigated. It has a maximum current electrode separation（AB/2） of 100 m. Three to four distinct geoelectric layers were observed, namely, the top layer, the weathered layer, the fractured/fresh layer, and the fresh basement layer. The observed frequencies in curve types include 21% of H, 4.2% of HA, 2.4% of K, 4.2% of A, 1.67% of KH and 3% of HK. Eight VES stations were delineated as ground water potentials of the area, with third and fourth layer resistivities ranging from 191 to 398 ？·m. Depths range from 13.60 to 36.60 m and thickness varies from 9.23 to 30.51 m. A correlation of the borehole log with the VES lithology is in agreement. Viable boreholes for good portable water should be sited at VES stations J8 and J10 having a fine aquifer at a depth of 36.60 and 17.80 m respectively with thickness of 30.51 and 15.07 m, respectively.