Explore the vast range of titles available.

This paper investigates subsurface structures within the United Arab Emirates University (UAEU) campus using microgravity survey. Gravity methods are widely used in geophysical exploration to detect density variations that may indicate subsurface anomalies. The primary objective of this research is to generate the Bouguer anomaly map of the UAEU campus to map subsurface structures and to assess potential geological hazards such as cavities. A total of 76 gravity stations were measured across the UAEU campus using the Scintrex CG-6 gravimeter. The acquired gravity data underwent standard processing to obtain the Bouguer anomaly, including tidal, instrumental drift, latitude, free air, Bouguer, and terrain corrections. The first Bouguer anomaly map of the UAEU campus was produced, revealing gravity values ranging from 112.8 to 115.1 mGal. High gravity anomalies are concentrated in the north-eastern and western regions, while lower gravity anomalies are predominantly observed in the southeastern and southwestern areas. Gravity gradient derivative techniques, such as the horizontal gradient, tilt angle, horizontal derivative of tilt angle and analytic signal were applied to the Bouguer anomaly. A 3-D gravity inversion was performed, modeling density variations from the surface down to a depth of 300 m below the sea level. The study successfully identified significant density contrasts indicative of probable cavities or low-density bodies, lithological variations and possible faults zones dominant structural trends along WNW-ESE, NW-SE, N-S, and E-W directions in the study area. Two distinct geological layers were identified: a shallow layer extending up to approximately 50 m and a comparatively deeper layer ranging from 50 to 100 m in depth. The 3-D inversion model delineated two prominent low-density anomalies at depths of 125–175 m from surface, suggesting the presence of cavities or low-density zones. This research represents the first high-resolution microgravity study of the UAEU campus, establishes a baseline microgravity dataset for the UAEU campus. The results enhance understanding of subsurface and highlight the need for further geotechnical and geophysical investigations to validate and refine cavity detection and hazard assessments.

Solar photovoltaic (PV) plays a crucial role in China’s pursuit of carbon neutrality. Assessing the PV power potential over China is essential for future energy planning and policy making. Surface solar radiation and panel tilt angle are critical factors influencing PV power generation. However, existing solar radiation datasets cannot fully meet assessment needs due to insufficient temporal coverage and limited accuracy, and the impact of panel tilt angles on PV potential is largely overlooked. This study developed a PV power estimation framework to assess the long-term (1980–2019) PV power potential at 609 stations across China, based on reconstructed high-quality solar radiation and optimized tilt angles. The validation of PV power estimates using ground measured outputs from four operational PV power stations indicated a correlation coefficient of 0.67 and a root mean square error of 0.07 for estimated daily capacity factor (CF). The assessment results revealed that the multi-year mean CF of China is 0.149 ± 0.031, with higher potentials in northern provinces and lower in southern provinces. The mean annual CF shows a declining trend of −7 × 10−4 per decade during 1980–2019, with significant decreases primarily in heavily polluted regions. In addition, we propose an optimal tilt angle estimation model based on diffuse fraction, achieving higher accuracy than previously released models. The estimated optimal tilt angle results in an increase in PV energy yield by 14.9 TWh/year for China compared with latitude-based schemes, based on China’s cumulative PV capacity by 2023 (609 GW). Our findings provide valuable insights for the effective implementation of solar PV projects in China.

We report on the impact of effective Prandtl number, variable magnetic field and viscous dissipation on MHD bioconvective micropolar nanofluid flow over an inclined stretching surface. The governing partial differential equations of continuity, momentum, energy, angular momentum, nanoparticle concentration and density of gyrotactic microorganism are suitably transformed to non-linear ordinary differential equations using similarity variables. The numerical solutions of these ODE's are obtained using MATLAB bvp4c. A comparative study is carried out on previously published work to ascertain the efficiency of the simulated solution. Th effect of various relevant parameters on velocity, temperature, concentration, microorganism density, skin friction, heat transfer rate, mass transfer rate, couple stress coefficients and the density number of microorganisms are analysed and presented through tables and graphs. Findings show that the velocity, temperature and density of microorganism profiles are consistently stronger when the surface tilt angle exceeds the magnetic field tilt angle, regardless of the tilt angles combination. Also, larger values of the Eckert number magnifies the Sherwood number, and the local density number of the motile microorganism while it suppresses the skin friction and the Nusselt number. In addition, escalating values of the effective Prandtl number boosts the skin friction and the Sherwood number, while the Nusselt number and the local density number of the motile microorganism declines. Furthermore, elevating the bioconvection Rayleigh number results in higher fluid angular velocity, density of microorganism and Nusselt number, but simultaneously decrease the fluid velocity, skin friction, Sherwood number and local density number of microorganism.

The collision of the Indian plate and the Eurasian plate created shortening and imbrications with thrusting and faulting which influences northward tectonic movement. This plate movement has divided the Himalaya into four parts, viz . Outer Himalaya, Lesser Himalaya, Greater Himalaya, and Tethys Himalaya. The crystalline basement rock plays an imperative role for structural and tectonic association. The study has been carried out near Rishikesh-Badrinath neighborhood in the northwestern part of the Himalayan girdle with multifarious tectonic set up with thrusted and faulted geological setting. In this study area, 3D Euler deconvolution, horizontal gradient analysis, tilt angle (TILT) and horizontal tilt angle (TDX) analysis have been carried out using gravity data to delineate the subsurface geology and heterogeneity in the northwestern part of Himalaya. The Euler depth solutions suggest the source depth of about 12 km and various derivative analyses suggest the trend of the delineation thrust-fault boundaries along with the dip and strike direction in the study area.

BackgroundStroke results in an impaired sit to stand (STS) task. Pelvic movements are essential in daily living activities. Few studies investigated the effect of spine and pelvis separately on functional activities in stroke patients.ObjectiveThe study aimed to assess the angles of pelvic inclination (anterior and posterior pelvic tilt angles) (APT and PPT) during sitting position and during STS movement. It aimed also to determine the influence of sagittal pelvic tilt angles on STS performance in stroke patients.Patients and methodsThirty male hemi-paretic stroke patients (GI) and 15 matched healthy volunteer subjects (GII) represented the sample of this study. Stroke patients were assigned into two equal groups (group Ia and Ib). Sagittal pelvic tilt angles were measured by using the palpation meter inclinometer during sitting position and during initiation and mid of STS by using two dimensional (2D) video-based motion analysis system. Time of five repetitions STS test was used to assess the ability to perform STS task.ResultsThe results showed a significant increase of PPT angle during static sitting, a significant decrease in APT angle during initiation and mid of STS task and a significant increase in time taken for five repetitions STS test in both stroke groups (P < 0.05).ConclusionAbnormal pelvic alignment and movements affect the functional performance of stroke patients during sitting and sit to stand task.Trial registrationNCT03053154. Registered January 22, 2017. Retrospectively registered.

The study has been carried out in the transition zone of the Narmada-Son lineament (NSL) which is seismically active with various geological complexities, upwarp movement of the mantle material into the crust through fault, fractures lamination and upwelling. NSL is one of the most prominent lineaments in central India after the Himalaya in the Indian geology. The area of investigation extends from longitude 80.25°E to 81.50°E and latitude 23.50°N to 24.37°N in the central part of the Indian continent. Different types of subsurface geological formations viz. alluvial, Gondwana, Deccan traps, Vindhyan, Mahakoshal, Granite and Gneisses groups exist in this area with varying geological ages. In this study area tectonic movement and crustal variation have been taken place during the past time and which might be reason for the variation of magnetic field. Magnetic anomaly suggests that the area has been highly disturbed which causes the Narmada-Son lineament trending in the ENE-WSW direction. Magnetic anomaly variation has been taken place due to the lithological variations subject to the changes in the geological contacts like thrusts and faults in this area. Shallow and deeper sources have been distinguished using frequency domain analysis by applying different filters. To enhance the magnetic data, various types of derivatives to identify the source-edge locations of the causative source bodies. The present study carried out the interpretation using total horizontal derivative, tilt angle derivative, horizontal tilt angle derivative and Cos (θ) derivative map to get source-edge locations. The results derived from various derivatives of magnetic data have been compared with the basement depth solutions calculated from 3D Euler deconvolution. It is suggested that total horizontal derivative, tilt angle derivative and Cos (θ) derivative are the most useful tools for identifying the multiple source edge locations of the causative bodies in this tectonically active and transition zone area. As this area is highly prone to hydrocarbon bearing zone, hence, the integrated interpretation could reliably image various thrusts and faults boundaries and the source edge locations with dip and strike orientation along with the basement lineation in encouraging exploration for better understanding of the geo-scientific data.

In this study, we purposed to investigate the edge of geostructures and position of existing faults of the Shamakhy–Gobustan and Absheron hydrocarbon containing regions in Azerbaijan. For this purpose, the horizontal gradient, analytic signal, tilt angle, and hyperbolic of tilt angle methods were applied to the first vertical derivative of gravity data instead of Bouguer gravity data. We obtained the maps that show the previous lineaments which were designated by considering the maximum contours of horizontal gradient, analytic signal maps, and zero values of tilt angle, hyperbolic of tilt angle maps. The geometry of basement interface was also modeled utilizing the Parker–Oldenburg algorithm to understand the sediment thickness and coherency or incoherency between the gravity values and basement topography. The lineaments were held a candle to most current tectonic structure map of the study area. It was seen that the techniques used in this study are very effective to determine the old and new lineaments in the Shamakhy–Gobustan and Absheron regions. The epicenter distribution of earthquakes within the study area supports the new lineaments which are extracted by our interpretation. We concluded that better comprehension of Azerbaijan geostructures and its effect on the large scale works will be provided by means of this study.

This study provides a novel and comprehensive assessment of solar photovoltaic (PV) panel performance under varying environmental conditions, integrating laboratory experiments with real-world field studies to address challenges specific to mining operations. The research uniquely explores the combined effects of shading, temperature, humidity, dust deposition, and tilt angle, delivering actionable insights for optimizing PV systems in harsh conditions. Laboratory experiments demonstrated that a parallel configuration significantly minimizes power losses under partial shading, while a rise in temperature from 35 to 75 °C resulted in a notable 21.34% and 29.12% power output reduction for monocrystalline and polycrystalline panels, respectively. Furthermore, increased humidity (65.40 to 98.20%) caused a 35.82% decline in power output due to scattering effects. Field studies conducted in a surface mining environment revealed that dust accumulation led to a substantial 43.18% drop in maximum power output after 5 days, emphasizing the importance of regular cleaning. Optimal energy capture was achieved at a 15° tilt angle, aligning with the site's latitude. These findings underscore the novelty of using combined experimental approaches and field validation to improve PV performance in mining operations. Practical recommendations, including parallel configurations to mitigate shading losses, temperature regulation strategies, and frequent cleaning protocols, are proposed to enhance the sustainability and efficiency of renewable energy systems in challenging environments.

Global solar radiation is generally measured on a horizontal surface, whereas the maximum amount of incident solar radiation is measured on an inclined surface. Over the last decade, a number of models were proposed for predicting solar radiation on inclined surfaces. These models have various scopes; applicability to specific surfaces, the requirement for special measuring equipment, or limitations in scope. To find the most suitable model for a given location the hourly outputs predicted by available models are compared with the field measurements of the given location. The main objective of this study is to review on the estimation of the most accurate model or models for estimating solar radiation components for a selected location, by testing various models available in the literature. To increase the amount of incident solar radiation on photovoltaic (PV) panels, the PV panels are mounted on tilted surfaces. This article also provides an up-to-date status of different optimum tilt angles that have been determined in various countries.

This paper investigates and enhances unmanned aerial vehicle (UAV) relay-assisted free-space optics (FSO) optical wireless communication (OWC) systems under the effects of pointing errors (PEs) and atmospheric turbulences (ATs). The incorporation of UAVs as buffer-aided moving relays in the conventional FSO (CFSO) relay-assisted systems is proposed for enhancing the performance of PEs through AT. Using M-PSK (phase shift keying) and M-QAM (quadrature amplitude modulation), the impact of PEs on transmission quality is evaluated in this work. We evaluate and optimize the symbol error rate, outage probability (OP), and signal-to-noise ratio (SNR) for the UAV-to-ground station-based FSO communications systems. The spatial diversity-based relay-assisted CFSO systems can enhance the performance of the UAV-UAV FSO links. In this paper, a new FSO (NFSO) channel model for the hovering UAV-FSO OWC fluctuations under the PEs, AT effects, jitter, deviation, receiving an error, and wind resistance effects are established. To improve the performance of hovering UAV-based FSO relay OWC systems. We reduce the influence of UAV-FSO OWC fluctuations under PEs and AT effects. By receiving incoherent signals at various locations, the spatial diversity-based relay-assisted NFSO systems can significantly increase the system's redundancy and enhance connection stability. Numerical results show that to achieve a bit-error-rate (BER) of ≤ 10 - 5 , the required SNR is ≥ 23 dB when the wind variance of the UAVs σ α 2 increases from 0 to 7 mrad with FSO link distance L = 2000 m. The required SNR is ≥ 25 dB when the wind variance σ α 2 is 1 mrad at an OP of 10 - 6 . To obtain an average BER of 10 - 6 , the SNR should be 16.23 dB, 17.64 dB, and 21.45 dB when σ α 2 is 0 mrad, 1 mrad, and 2 mrad, respectively. Using 8-PSK modulation without PEs requires 23.5 dB at BER of 10 - 8 while 16-QAM without PEs requires 26.5 dB to maintain the same BER of 10 - 8 . Compared with 16-QAM without PEs, the SNR gain of 8-PSK without PEs is 3 dB. The results show the relay-assisted UAV-FSO system with five stationary relays can achieve BER 10 - 8 at 25 dB SNR in the ideal case and 10 - 5 at 27 dB SNR with AT and PE at FSO length 1000 m. The results show the relay UAV-FSO system outperforms the CFSO at the BER and SNR performance. The effects of UAV’FSO s fluctuation increase when the UAV-FSO link length, L fso increases. The results of the weak turbulence achieve better SER compared with MT and ST. The obtained results show that decreasing L fso can compensate for the effects of UAV-FSO link fluctuation on the proposed system. Finally, we investigated the CFSO relay-assisted UAV-FSO system with aided NFSO-UAVs spatial diversity-based relay-based on NFSO OWC and revealed the benefits of the resulting hybrid architecture.