81 research outputs found

    Recycling of Waste Glass as Partial Replacement to Fine Aggregate and Rice Husk Ash as Partial Replacement of Cement in Concrete Production

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    The Recycled Waste Glass (RWG) is a most suitable substitute to the natural sand to be utilized in the concrete manufacturing industry and Rice Husk Ash (RHA) is an agricultural by-product having enormous characteristics to utilize as cementitious material in concrete. This study was carried out to understand the effects of RHA as partial replacement to cement and RWG as a partial replacement to natural fine aggregate with 10%, 20% and 30% levels of substitutions in the concrete mixes respectively. The effects were investigated on the workability and compressive strength characteristics of fresh and hardened concrete. A total of 4 mixtures were prepared for M15 grade concrete with 1:2:4 concrete proportions and water to cement ratio of 0.55. Out of them one was controlled mixture and three were with 10%, 20% and 30% equal substitution levels of combined RHA and RWG. The acquired results showed that the slump values were like that of conventional concrete at combined incorporation of RHA and RWG at 10% replacement, but a decline was noticed at 20% and 30% replacement. The decline was due to the more surface area of RHA which absorbs more water. The compressive strength at 10%RHA and 10% RWG combined replacement in concrete mix was increased by 9.7% as compared to controlled mix after 28 days curing. The results were similar at 20%RHA and 20%RWG incorporation as compared to controlled concrete mix. It is concluded that RHA and RGW can be utilized at 10% equal replacement in the concrete and the cost of construction can be reduced. This research work will be helpful in developing a comprehensive scientific data base on combined utilization of RHA and RWG in the concrete mixes and the upcoming scientists, scholars and students will be benefitted

    Design of a high speed 18/12 switched reluctance motor drive with an asymmetrical bridge converter for electric vehicles

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    The application of permanent magnet free motors have gained a huge attention for pure electric and hybrid electric vehicles. This paper proposed the design of 20-kW switched reluctance motor having 18 stator poles and 12 rotor poles by using finite element analysis machine design software Infolytica magnet and the main focus is to achieve the high speed, torque with adequate performance for electric vehicles. The asymmetric bridge converter has been used and the series of varying the excitation voltage, slot fill factor with respect to the number of turns and stranded area of the conductor has been analysed. Additionally, in order to the electromagnetic force vector, the switching sequence is examined. The simulation results show the great potential of the suggested motor and can provide a good starting torque with high speed and can be suitable to achieve the freedom Car 2020 electric vehicle target

    On the Soliton Solutions for the Stochastic Konno–Oono System in Magnetic Field with the Presence of Noise

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    In this study, we consider the stochastic Konno–Oono system to investigate the soliton solutions under the multiplicative sense. The multiplicative noise is considered firstly in the Stratonovich sense and secondly in the Itoˆ sense. Applications of the Konno–Oono system include current-fed strings interacting with an external magnetic field. The F-expansion method is used to find the different types of soliton solutions in the form of dark, singular, complex dark, combo, solitary, periodic, mixed periodic, and rational functions. These solutions are applicable in the magnetic field when we study it at the micro level. Additionally, the absolute, real, and imaginary physical representations in three dimensions and the corresponding contour plots of some solutions are drawn in the sense of noise by the different choices of parameters.This research was funded by Basque Government through Grants IT1555-22 and KK-2022/00090; and (MCIN/AEI 269.10.13039/501100011033/FEDER, UE) for Grants PID2021-1235430B-C21 and PID2021-1235430B-C22

    Effects of Diagenesis on the Reservoir Quality in the Upper Sands of Lower Goru Formation, Badin Block, Lower Indus Basin, Pakistan

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    The core samples of B member of upper sand reservoir rocks of the lower Goru Formation from three wellsof the Badin block were studied using thin section, XRD, and SEM techniques to investigate the diagenetic trends andtheir effect on reservoir quality. Microscopic study indicates that the B sand unit is mature with quartz as thepredominant mineral constituent with variable amount of feldspar and lithic minerals. The QFL plot indicates that mostof the samples are plotted in the field of quartz arenite, sub-litharenite and sub-arkose respectively. A few samplesbelong to the category of litharenite and feldspathic litharenite. The feldspars were partially to completely altered tokaolinite and other clay minerals. Coarse-crystalline or micro-crystalline calcite is the predominant cementing material.Bulk rock XRD analysis also confirms that the main mineral constituents of there samples are quartz and calcite invariable proportions. The undulose extinction and fracturing of quartz grains indicate that the area remained understress. Moreover, such fracturing is post-depositional and therefore is the product of late diagenesis. Scanning ElectronMicroscopic (SEM) images at 50 micrometer (μm) size show irregular type of fracturing within the quartz grains. Thislate stage fracturing of quartz has also generated various types of channels which may serve as secondary porosity. Thequartz overgrowth was observed in some samples due to late stage diagenesis. The micro-crystalline cement in the formof calcite is mostly present within the pores in fractured quartz. The results indicate that the diagenesis played asignificant role in improving the reservoir characteristics of B sand by increasing the porosity due to quartz fracturing,feldspar dissolution, alteration and quartz corrosion. Hence, better understanding of reservoir heterogeneities inporosity through diagenetic studies can be helpful in evaluating potential reservoir horizons for hydrocarbonaccumulation on spatial and temporal scales

    The role of diffusion of innovation theory towards the adoption of halal meat supply chain

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    This paper aims to examine the factors that drive the exporter’s influence toward halal meat supply chain adoption by encompassing the diffusion of innovation (DOI) theory in the context of Pakistan. Using DOI as an underpinning theory, this study evaluates halal supply chain adoption by collecting data from the members of associations from Pakistan. A total of 258 useable responses were received, and PLS-SEMwas adopted using SmartPLS. The exporter’s adoption of the halal supply chain is determined not only by perceived relative advantage and perceived compatibility but also by perceived complexity, religious beliefs and awareness. Though this study has practical and managerial implications, it has few limitations. Further studies need to be conducted in other contexts as well with a larger population. There are limited studies that have tested DOI theory in the context of the halal meat supply chain in Pakistan. Therefore, the author extends the diffusion theory of innovation in the current work. Further, this paper will be a helpful reference guide for academicians, practitioners and researchers

    Comparative analysis of UWB balance Antipodal Vivaldi Antenna for array configuration

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    In this paper, an Ultra-wideband Balance Antipodal Vivaldi Antenna in planar and h-plane array configuration is presented. The comparison of four elements of BAVA array in both planes has been observed. Each element of an antenna printed on the glass-reinforced epoxy laminate material (FR4) with a thickness of 1.5mm and relative permittivity of 4.3. The dimension of every single element is 60.75mm x 66mm approximately. The array elements of both planes almost cover the whole UWB frequency range with the reflection coefficient of -10dB. Based on the simulation results, the array elements in planar configuration showing good reflection and works well at 3.2GHz frequency while the configuration in h-plane the array elements works well at 7GHz of frequency. In planar configuration, the operating frequency of antenna elements is shifting as a result of the distance between inter elements which intensification in wavelength. The array elements in h-plane produce more gain up to 10.2 dB with good radiation patterns as compared to the planar plane. The antenna design and optimization development are verified using CST simulation software

    A Nonlinear Structure of a Chemical Reaction Model and Numerical Modeling with the New Aspect of Existence and Uniqueness

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    In this article, a nonlinear autocatalytic chemical reaction glycolysis model with the appearance of advection and diffusion is proposed. The occurrence and unicity of the solutions in Banach spaces are investigated. The solutions to these types of models are obtained by the optimization of the closed and convex subsets of the function space. Explicit estimates of the solutions for the admissible auxiliary data are formulated. An elegant numerical scheme is designed for an autocatalytic chemical reaction model, that is, the glycolysis model. The fundamental traits of the prescribed numerical method, for instance, the positivity, consistency, stability, etc., are also verified. The authenticity of the proposed scheme is ensured by comparing it with two extensively used numerical techniques. A numerical example is presented to observe the graphical behavior of the continuous system by constructing the numerical algorithm. The comparison depicts that the projected numerical design is more productive as compared to the other two schemes, as it holds all the important properties of the continuous model.Basque Government, Grant IT1555-22 and Grant KK-2022/00090 MCIN/AEI 269.10.13039/ 501100011033, Grant PID2021-1235430B-C21/C22

    Exploration of Shallow Geothermal Energy Aquifers by Using Electrical Resistivity Survey in Laki Range Jamshoro district Sindh, Pakistan

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    Geothermal water is increasingly used around the world for its exploitation. Bulk electrical resistivity differences can bring significant information on variation of subsurface geothermal aquifer characteristics. The electrical resistivity survey was carried out in Laki range in lower Indus basin in the study area to explore the subsurface geothermal aquifers. The Schlumberger electrode configuration with range from 2 m to 220 m depth was applied. Three prominent locations of hot springs were selected including Laki Shah Saddar, Lalbagh and Kai hot spring near Sehwan city. After processing resistivity image data, two hot water geothermal aquifers were delineated at Laki Shah Sadder hot springs. The depth of first aquifer was 56 m and its thickness 38 m in the limestones. The depth of second aquifer of 190 m and with thickness of 96 m hosted in limestone. In Lalbagh hot springs two geothermal aquifers were delineated on the basis of apparent resistivity contrast, the depth of first aquifer zone in sandstone was in sandstone 15 m and thickness 12 m, while the depth of second aquifer was 61m and thickness was 35m. In Kai hot springs two hot water geothermal aquifers were delineated. The depth of first geothermal aquifer was 21m and thickness was 18 m and the depth of second aquifer was 105 m and thickness was 61m present in sandstone lithology. Present work demonstrates the capability of electrical resistivity images to study the potential of geothermal energy in shallow aquifers. These outcomes could potentially lead to a number of practical applications, such as the monitoring or the design of shallow geothermal systems

    UWB antenna based time-domain approach for through the walls gap estimation

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    This paper has introduced a novel experimental system adopted a time domain approach for estimating through wall distance and recognizes buried objects behind the wall. The designed and fabricated balanced antipodal Vivaldi antenna (BAVA) has been used for the development of UWB system. The working mechanism of an intended detection system based on time domain reflectometry (TDR) and ground-penetrating radar (GPR). A miniature pulse in the UWB range is generated by the vector network analyzer (VNA) to irradiate a barrier made of two walls separated by airgap between them. The signal radiations reflect partially from the front wall while remaining goes through for getting reflected from the rear wall. The VNA is used for measuring the time interval passed between the instant when an incident signal irradiates the first wall and the instant when the incident signal gets reflected from the rear wall. The investigational process of a system is carried out by UWB antenna probe. The detected information is attained using the values of reflection coefficient (S 11 ) represented in time domain measurements. Experimental results have been proved the ability to detect wall gap as well as the width estimation between two walls with high accuracy. The maximum percentage error has been found to not exceeding 4.5% in the worst condition

    Lessons and implications from a mass immunization campaign in squatter settlements of Karachi, Pakistan: an experience from a cluster-randomized double-blinded vaccine trial [NCT00125047]

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    OBJECTIVE: To determine the safety and logistic feasibility of a mass immunization strategy outside the local immunization program in the pediatric population of urban squatter settlements in Karachi, Pakistan. METHODS: A cluster-randomized double blind preventive trial was launched in August 2003 in 60 geographic clusters covering 21,059 children ages 2 to 16 years. After consent was obtained from parents or guardians, eligible children were immunized parenterally at vaccination posts in each cluster with Vi polysaccharide or hepatitis A vaccine. Safety, logistics, and standards were monitored and documented. RESULTS: The vaccine coverage of the population was 74% and was higher in those under age 10 years. No life-threatening serious adverse events were reported. Adverse events occurred in less than 1% of all vaccine recipients and the main reactions reported were fever and local pain. The proportion of adverse events in Vi polysaccharide and hepatitis A recipients will not be known until the end of the trial when the code is broken. Throughout the vaccination campaign safe injection practices were maintained and the cold chain was not interrupted. Mass vaccination in slums had good acceptance. Because populations in such areas are highly mobile, settlement conditions could affect coverage. Systemic reactions were uncommon and local reactions were mild and transient. Close community involvement was pivotal for information dissemination and immunization coverage. CONCLUSION: This vaccine strategy described together with other information that will soon be available in the area (cost/effectiveness, vaccine delivery costs, etc) will make typhoid fever control become a reality in the near future
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