69 research outputs found
Crystalline phase, surface morphology and electrical properties of monovalent-doped Nd0.75Na0.25Mn1-yCoyO3 manganites
Get PDFPerovskite-type manganites Nd0.75Na0.25Mn1-yCoyO3 (y = 0 – 0.05) have been investigated to clarify the influence of Co-doped on crystal phase and morphological study as well as electrical transport properties. The Nd0.75Na0.25Mn1-yCoyO3 samples are prepared via solid state synthesis method. X-ray diffraction analysis revealed all the samples are essentially single phased and the peaks are indexed to an orthorhombic structure with Pnma space. The morphological study from scanning electron microscope shows the improvement of the grains boundaries and sizes as well as the compaction of particles can be seen as cobalt doping increased. On the other hand, the temperature dependence of electrical resistivity measurements using four-point-probe technique indicates all samples maintained an insulator like behaviour down to low temperature. Analysis of the resistivity change with respect to temperature, dlnρ/dT-1 versus T reveals a slope changes of resistivity has been observed and a boarder peak exist for y = 0 sample and the peaks become significantly obvious for y = 0.02 and 0.05 samples. The peaks are observed in the range of charge ordering (CO) transition indicate the existence of CO in the system
Correction: Ahmad et al. TiO2/Activated Carbon/2D Selenides Composite Photocatalysts for Industrial Wastewater Treatment. Water 2023, 15, 1788
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Fabrication of Ternary MoS<sub>2</sub>/CdS/Bi<sub>2</sub>S<sub>3</sub>-Based Nano Composites for Photocatalytic Dye Degradation
No full textThe synthesis and design of low-cost visible-light-active catalysts for the photodegradation of organic dyes have been regarded as an efficient way to use solar energy in addressing environmental issues. We report the fabrication of MoS2/CdS nanoparticles functionalized with Bi2S3 nanoflakes. The ternary composites of “MoS2/CdS/Bi2S3” were synthesized in situ by a hydrothermal method at different temperatures. The changes in structural, optical, and morphological properties of the synthesized CdS/MoS2/Bi2S3 were explored. The effects of Bi2S3 on CdS/MoS2 were thoroughly studied by performing an X-ray diffractometer (XRD), a scanning electron microscope (SEM), an ultra-violet–visible spectrometer (Uv–vis), and Fourier transform infrared spectroscopic (FT-IR) studies of the nanoparticles. XRD confirms the cubical crystal structure of the nanoparticles. SEM studies possess the modulation in the surface morphology with the tenability in volume ratios of “MoS2/CdS/Bi2S3” composites. It was observed that the bandgaps calculated using absorption measurements could be manipulated from 2.40 eV to 0.97 eV with varying Bi2S3 in the MoS2/CdS nanostructures. FT-IR confirmed the synthesis of “MoS2/CdS/Bi2S3” nanoparticles. On allowing the visible light to fall for 120 min, it was observed that “MoS2/CdS/Bi2S3” degrades the methylene blue up to 90%. The calculated results of “MoS2/CdS/Bi2S3” suggest that the synthesized material could be a strong candidate for photodegradation applications. This research work explains the synthesis of MoS2/CdS/Bi2S3-based nanocomposites for the degradation of dye using a photocatalytic process. The final results show that this catalyst effectively degrades the dye
PCA-Based Advanced Local Octa-Directional Pattern (ALODP-PCA): A Texture Feature Descriptor for Image Retrieval
Get PDFThis paper presents a novel feature descriptor termed principal component analysis (PCA)-based Advanced Local Octa-Directional Pattern (ALODP-PCA) for content-based image retrieval. The conventional approaches compare each pixel of an image with certain neighboring pixels providing discrete image information. The descriptor proposed in this work utilizes the local intensity of pixels in all eight directions of its neighborhood. The local octa-directional pattern results in two patterns, i.e., magnitude and directional, and each is quantized into a 40-bin histogram. A joint histogram is created by concatenating directional and magnitude histograms. To measure similarities between images, the Manhattan distance is used. Moreover, to maintain the computational cost, PCA is applied, which reduces the dimensionality. The proposed methodology is tested on a subset of a Multi-PIE face dataset. The dataset contains almost 800,000 images of over 300 people. These images carries different poses and have a wide range of facial expressions. Results were compared with state-of-the-art local patterns, namely, the local tri-directional pattern (LTriDP), local tetra directional pattern (LTetDP), and local ternary pattern (LTP). The results of the proposed model supersede the work of previously defined work in terms of precision, accuracy, and recall
Abu Bakr Effendi: a report on the activities and challenges of an Ottoman Muslim theologian in the Cape of Good Hope
No full textThis thesis presents the religious activities of an Ottoman Islamic scholar Abu Bakr Effendi and his educational challenges at the Cape of Good Hope. Abu Bakr Effendi was a professor of canon law who was sent to the Cape by the Ottoman Caliph in order to resolve the religious issues as well as educate the Muslims in South Africa in the second half of the nineteenth century. This study takes into consideration diverse archival materials that explain different dimensions of the socio-historical events which happened during Effendi's stay in South Africa. Due to limited reliable sources, Effendi's activities have not been examined by researchers extensively. Several local newspapers, South African and Ottoman archival materials not used before in such studies, private family documents, foundation (Waqf) records and official correspondences have been used in this study and contributed to understanding the social-religious situation amongst Muslims at the Cape of the nineteenth century. Applying a comparative historical method, the study shows how Effendi became a prominent scholar in society despite his reformist understanding with regards to Islamic topics which made him a marginal theologian in the eyes of local Muslims. In this sense, the study illustrates the contribution of his works in the Muslim social sphere and how it enabled the emergence of a Muslim consciousness and identity in Southern Africa. Finally, with his cultural and educational endeavors, Effendi became a historical figure in South African society and this reality has been illuminated by rich archival documents
Hybrid System for Electricity Generation using Waste Heat & Wind from Exhaust Duct of Generator
No full textInternational audienceThe objective of this paper is to utilize wasted heat and hot pressurized air from the exhaust duct of the generator in generating station to produce electricity. This heat and exhaust air is produced due to two types of losses i.e, core losses and copper losses inside generator and its temperature gradient with respect to the external environment. To accomplish this task a hybrid system consisting of Thermoelectric Cells and Wind Turbine assembly is designed in which Thermoelectric Cells produces electricity using the wasted heat based upon the Seebeck effect while the wind turbine generates electricity due to high speed wind striking its specially designed blades according to the modern Aero-Dynamical designs. This hybrid system will work in parallel with the main Generator acting as auxiliary electricity generating source. This system will provide improved results at higher temperature differences and high pressure of wind
Six-Minute Walk Test Performance in Healthy Adult Pakistani Volunteers
Get PDFObjective: To determine the six-minute walking distance (6MWD) for healthy Pakistanis, identify factors affecting 6MWD, compare published equations with the local data and derive an equation. Study Design: Cross-sectional study. Place and Duration of Study: Two medical institutes of Karachi, from January to May 2011. Methodology: Subjects between 15 and 65 years were prospectively enrolled after screening. A standardized 6MWT was administered. SpO2, HR, BP and dyspnoea scores were determined pre- and post-test. Results: Two hundred and eleven (71%) men and 85 (29%) women participated. Mean 6MWD was 469.88 ± 101.24 m: men walked 502.35 ± 92.21 m and women walked 389.28 ± 74.29 m. On univariate analysis, gender, height, weight and age showed a significant relationship with the 6MWD. Gender and age were identified as independent factors in multiple regression analysis, and together explained 33% of the variance. The gender-specific prediction equations were: 6MWD (m) for men = 164.08 + (78.06*1) - (1.90*age in years) + (1.95*height in cms) 6MWD (m) for women = 164.08 - (1.90*age in years) + (1.95*height in cms). Conclusion: 6MWDs among the volunteer subjects were shorter than predicted by reference equations in literature. Height, gender and weight combined explained 33% of the variance. The moderate over-estimation of the 6MWD in Pakistani subject. The proposed equation gives predicted (mean) 6MWDs for adult Pakistani naïve to the test when employing standardized protocol
A Comprehensive Review on Adaptability of Network Forensics Frameworks for Mobile Cloud Computing
Get PDFNetwork forensics enables investigation and identification of network attacks through the retrieved digital content. The proliferation of smartphones and the cost-effective universal data access through cloud has made Mobile Cloud Computing (MCC) a congenital target for network attacks. However, confines in carrying out forensics in MCC is interrelated with the autonomous cloud hosting companies and their policies for restricted access to the digital content in the back-end cloud platforms. It implies that existing Network Forensic Frameworks (NFFs) have limited impact in the MCC paradigm. To this end, we qualitatively analyze the adaptability of existing NFFs when applied to the MCC. Explicitly, the fundamental mechanisms of NFFs are highlighted and then analyzed using the most relevant parameters. A classification is proposed to help understand the anatomy of existing NFFs. Subsequently, a comparison is given that explores the functional similarities and deviations among NFFs. The paper concludes by discussing research challenges for progressive network forensics in MCC
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