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Arithmetic Mean-Geometric Mean Inequality for Convex Fuzzy Sets
Full text linkConvex analysis is a discipline of mathematics dedicated to the explication of the properties of convex sets and convex functions. Convex functions are extremely useful in proving many famous inequalities in mathematics. It is widely known that inequalities defined by convex functions originated with the works done by Holder and Jensen among others and applied to modeling a variety of problems both in hard and soft sciences. It is said that the arsenal of an analyst is heavily stocked with inequalities. Studies related to convexity have kept occupying a central position in almost all areas of mathematics, especially in functional analysis and operations research. Following the emergence of fuzzy set theory, fuzzy convexity alongside a number of related concepts has been explicated. However, not much has been done regarding fuzzy inequalities defined by fuzzy convexity. In this paper, a novel attempt to study arithmetic mean-geometric mean is proposed. In this short note, we provide two proofs of the arithmetic mean-geometric mean inequality for convex fuzzy sets.
Mathematics Subject Classification 2020: 03E72, and 94D05
Experimental Measurements to Study Correlations between Porosity, Absolute Permeability, and Capillary Pressure
Full text linkRock permeability is a measurement of how easily a fluid can flow through a rock while porosity is a measure of the rock’s storage capacity or its pore volume that is capable of holding fluids. In many cases correlations may exist between porosity and permeability, however, these correlations are usually derived for a certain formation, and therefore they do not exhibit general application or validity. Cross-plot of permeability versus porosity data, to create a porosity-permeability transform, is sometimes used to assign permeability values to areas of a reservoir where permeability data are unavailable. The capillary pressure curve is also used to predict rock absolute permeability. In the present work, porosity, absolute permeability, and capillary pressure were measured experimentally to investigate and establish new correlations between porosity, Klinkenberg-corrected permeability, and capillary pressure. Fifty-nine core plugs, obtained from two different fields located in Sirte basin, Libya, were utilized. Results indicate that porosity might be a reasonable estimator of permeability, as correlations between porosity and permeability were observed and empirical permeability equations based on porosity were established. Capillary pressure was observed to be overall inversely proportional to permeability, however, determined capillary pressure curves varied within the same formation
The Electromagnetic Scattering Problem by a Cylindrical Doubly-Connected Domain at Oblique Incidence: An Inverse Problem
Full text linkIn this work, we examine the inverse problem to reconstruct the inner boundary of a cylindrical doubly-connected infinitely long medium from measurements of the scattered electromagnetic wave in the far-field. We consider the integral representation of the solution to derive a non-linear system of equations for the unknown radial function. We propose an iterative scheme using linearization and regularization techniques
Selection and Application of Beam Pumping Unit for Heavy Oil Production
Full text linkBeam pumping units were among the first and are still among the most widely used artificial lift systems. This study investigates the components of beam pumping units and the manufacturing mechanism and design procedure recommended by Recommended Practice and the QRod simulator. The API provides API RP 11L Recommended Practice to obtain the values and operating characteristics for each component in dimensionless form. A trial-and-error method is used during the design procedures to determine the best surface and subsurface equipment for a given well's data. When completing a well, the artificial lift method must be considered to ensure that the well is able to be produced at a satisfactory rate. Besides, the procedures created nine cases to compare the requirements of different production rates and depths for a heavy oil well with 14 APIs. A depth of 5,000 ft with a rate of 300 bbl/day and a depth of 7,000 ft with a rate of 500 bbl/day is the specific production rate and depths at which the well will produce. For 300 BBL/Day the tubing size selected was 2-7/8” OD, for this size the suitable plunger size is 2”, and the suitable stroke length was 74in. In cases 6, 8, and 9, all the simulated rod strings were unable to handle the stress imposed by the combination of high depth and high production rate. As a result, all designed systems will fail during production
A Comprehensive Review on Third-Generation Photovoltaic Technologies
Full text linkThe renewable energy industry has revolutionized due to photovoltaic (PV) technologies, which offer a clean and sustainable alternative to conventional energy sources. Third-generation photovoltaic technologies refer to a group of emerging PV technologies aiming to surpass the efficiency and cost-effectiveness of traditional silicon-based solar cells. Different ceramic materials have also been investigated for use in these advanced PV technologies. This review examines the science, current state, and advancements of third-generation PV systems for wide-scale implementation. The first section of this study provides an overview of the development of PV technologies from the first to the third generation, highlighting the most significant novel developments made at each step. Organic photovoltaic (OPV) cells, dye-sensitized solar cells (DSSCs), and perovskite solar cells (PSCs) are discussed here as a few new technologies that constitute the third generation, also known as the next generation of advanced PV. This review presents how these devices can be used in specialized settings, including indoor and low-light environments, thereby expanding the range of energy harvesting potential. The brief history of these emerging technologies, their current status, future developments, and key challenges are discussed in this review paper
Crustal and Lithospheric Variations along the Western Passive Continental Margin of the Indian Peninsula
Full text linkThe western passive continental margin (WPCM) of the Indian Peninsula is one of the world's largest and most remarkable escarpments, signifying a boundary between oceanic and continental lithospheres. It traverses distinct lithological units, majorly the SGT, WDC, and DVP, each characterized by distinct geological structures, geochronological histories, and petro-physical properties. Despite numerous research efforts, the exact mechanisms governing the WPCM evolution and its developmental connections remain unclear due to limited data and significant uncertainties. In our study, we meticulously analyzed global and local models, focusing on the Western Ghats (WG), to examine crust and lithosphere thickness. Our analysis revealed significant uncertainties in crustal and lithospheric variations, with a maximum difference of 10.68% in crust thickness and 20.04% in lithospheric thickness across different major lithological formations in the WG. These differences can have a substantial impact on the geodynamic analysis of lithospheric structures and tectonic evolution. Additionally, we developed a 2-D lithospheric density model over the WG, crossing the major geological units, which delineates the crust and lithospheric structure between the eastern and western sides of the escarpment. Our results, in conjunction with geomorphological data, suggest that the WPCM’s thick lithosphere with elevated topography illustrates a continuous upwarp, supported by flexural compensation of uplifted terrain. The movement of the Indian plate, primarily in the N-S and NW-SE directions, subsequently modified the entire escarpment. This model offers insights into the evolution of the WPCM and potentially contributes to the formation of the NE-SW fault in the southern part of the South Indian Shield, with potential implications for the Palghat gap
Hydrogeological Analysis of Cretaceous and Tertiary Aquifers in Semiarid Sokoto Basin, Northwestern Nigeria: Implications for Sustainable Groundwater Development
Full text linkGroundwater development in arid and semiarid regions is accelerated by expanded irrigation farming, industrialisation, and municipal water supply. This study provides a detailed hydrogeological analysis of sedimentary aquifers of the Sokoto basin, Northwestern Nigeria, for improved water resource development and management. Hydrogeological data, including static water level (Swl), pumping water level (Pwl), pumping test (Pt), and estimated yield (Ey), were analysed. A total of three hundred (300) observations on Swl, Pt, Pwl, Ey, and Hps were derived from boreholes and analysed using Factor analysis (FA) and Regression analysis (RA). Results showed that Gwandu Formation is the most prolific aquifer. Boreholes can yield more than 24000 litres per hour (L/h). This was followed by The Kalambaina limestone aquifer, which has the potential to yield about 15000 (L/h). However, the Taloka Formation is characterised by very poor aquifers in most of the basin, though along the Jega-Dogon Daji axis, boreholes can yield more than 24000 (L/h). Likewise, boreholes tapping the Wurno Formation can produce a maximum yield of 24000 (L/h). Estimated yields from boreholes were less than 1500 (L/h) from the Gundumi aquifer, and the maximum borehole yields were 17760 (L/h) in the Illo aquifer. Statistical modelling showed that all the analysed variables are significant concerning groundwater potentials and variability of borehole yields in the study area. Therefore, future groundwater resource development in the study area should be based on a proper analysis of the geological configurations of the Sokoto basin. This study provides an outlook on the groundwater potentials of the study area and aquifers that can provide a basis for sustainable groundwater development policy. Thus, the study has shown how multivariate and regression analysis can be used to study the hydrogeological conditions of a particular basin. Therefore, it is hoped that this study's findings will inspire other researchers to take a comparable approach
Determination of Multiple-target Equivalent Static Wind Load of Large-span Roof Structures based on Clustering Analysis Techniques
Full text linkSpatial structures in modern society exhibit a city’s distinguishing features and show its strength in building technology. Large-span roof structures are mostly seen among spatial structures for various activities. Large-span roof structures are usually sensitive to wind loads due to their lightness in materials and curved geometric appearance. However, spatial structures are generally designed with many structural members, making it challenging to determine adequate load distributions for structural safety analysis. This paper intends to introduce the concept of the multiple-target equivalent static wind loads and to demonstrate how to reduce the heavy computational burden when the structural designer needs to consider multiple loading effects of the target structure. The wind tunnel test of an elliptical-shaped stadium structure with a flat roof is first conducted to show the fundamental aerodynamic characteristics. The methodologies of the background-component wind force based on the load-response-correlation (LRC) method and the resonant-component wind force based on the inertial force method are then introduced for the specification of single-target equivalent static wind loads. Finally, the clustering analysis technique is adopted to explain the concept of the multiple-target equal static wind loads. A decay index is proposed to indicate how the clustering technique improves the specification of equivalent static wind loads
Editorial: Designing Spaces and Services in Contemporary Cities
Full text linkSome questions accompany us very closely throughout our experiences and professional years. They may become a constant topic in our educational path, a gap to answer within research. Or they could become the lenses through which we glance and understand the world around us. According to Marina Waisman [1], the practice of architecture is based on relationships built from the conditions of a given time and place, and it is these conditions that will allow us to think and practice architecture reflectively and critically
Cooling Strategy Optimization of a Permanent Magnet Synchronous Motor
Full text linkIn this study, 250 kW, 9 phase, outer rotor types of Permanent Magnet Synchronous Motor (PMSM) are taken into consideration. To optimize the cooling efficiency of the motor, firstly, the motor geometry is obtained, and the e-magnetic model of the geometry is validated with the manufacturer`s data. Secondly, by using the validated e-magnetic model, the cooling system of the motor was analyzed by using the thermal model of the Motor-CAD. The thermal model is also validated with the real-time experiments which are held on an electric bus at constant speed experimentally. For finding the best cooling strategy for the motor, after validation, the effect of the mass flow rate, the type of the cooling refrigerant, the cooling pipe diameter size, and the change of torque are analyzed on the validated model. The results showed us that mass flow rate and torque have a significant effect on winding temperature, and the Taguchi method showed that [mass flow rate (A)=50 l/min, pipe diameter (B) = 17.7 mm, number of turns (C)=20, type of fluid (D)= EGW50/50, torque (E)=2000 Nm] is the best cooling design parameters for the cooling strategy of the considered PMSM