19 research outputs found
Probing into the properties of B4C reinforced nickel phosphorus-based nanocomposite coating
No full textNickel-based coatings are well known for their good corrosion resistance performance. However, these materials suffer from inferior mechanical properties that limit their wider application. This work investigates the synthesis, and performs an exhaustive characterization, of Ni-P-B4C nanocomposite coatings developed through conventional electrode -position using a modified Watts bath. The study examines the effect of an increase in the concentration of boron carbide nanoparticles (BCNPs) on the structural, morphological, topographical, mechanical and electrochemical properties of the nanocomposite coating. Vickers microhardness tester and nanoindentation technique were utilized to elucidate the role of BCNPs in modifying the mechanical response of nanocomposite coatings. Furthermore, corrosion resistance of the nanocomposite coatings was investigated through d.c potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Comparison of the properties of the developed coatings revealed the remarkable improvement in the properties of Ni-P-B4C nanocomposite coatings when compared to the bare mild steel substrate and the Ni-P coatings. The enhanced corrosion resistance and superior mechanical properties of Ni-P-B4C nanocomposite coatings make them attractive for many industries. Based upon the experimental findings, a possible mechanism for the synthesis and improved corrosion resistance of Ni-P-B4C nanocomposite coatings was also proposed. (c) 2022 The Author(s). Published by Elsevier B.V
X-ray photoelectron spectroscopy studies of Fe3O4 films on Si and MgO substrates grown by pulsed laser deposition
No full textConflict of law and the methodology of Tarjīẖ : a study in Islamic legal theory
No full textIslamic law never achieved unity but expressed itself in, at least, four surviving schools. More interestingly, contemporary Muslim communities are still divided among themselves on a number of issues related to their laws. This work describes how problem of legal conflicts have been tackled by Muslim jurists. It is an attempt to examine closely the phenomenon of conflict in Islamic law from the standpoint of usūl-al-fiqh or Islamic legal theory. In fact, much is heard nowadays of the contradiction in the body of Islamic law. Whilst in contrast, little is presented in terms of the methodology of removing this conflict. The present work therefore, attempts to redress this balance. The emphasis of the work will be concerned primarily with tarjīh methodology ; how to give preference to one piece of evidence or argument over the other when they conflict. Nevertheless, considerable concern is given to investigating the background to the conflict of law in the Shari'ah.
This study of a neglected area in Islamic legal scholarship will be an important source of reference to students, both practising and theoretical jurists or to anyone who merely wishes to increase his knowledge of legal themes, particularly legal conflict. The very aim of the work is to argue that conflict is a natural and unavoidable consequence of legal study because legal conflict is only conflicting principles and arguments adduced by both the classical and modern jurists to reach what is actually intended by God in the target case. Therefore, conflicts are inevitable in most of the cases in fiqh owing to the variety of principles set out to deal with one piece of legal evidence, let alone with all the pieces of legal evidence in question.
Tarjīh is therefore, an important and workable instrument in the re-examination of these conflicts and in arriving at the most accurate principle for establishing the law for as long as this is possible. It is hoped that the discovery of new facts and the increase of knowledge which results from the broadening and deepening of the research will positively contribute to the process of unification of Islamic law
Corrosion behavior of electrodeposited Ni-B coatings modified with SiO2 particles
No full textThe need for coatings with improved operation is vital to insure safety and high output of industrial plants. Electrodeposition is a valuable surface modification technology that can be used to develop various kinds of coatings. Although, Ni-B coatings have good mechanical properties (hardness and wear) but are suffering from inferior corrosion resistance. The development of Ni-B composite coatings by incorporating insoluble hard particles such as metal oxides (Al2O3, TiO2 ) through electrodeposition process has generated a great interest among the research community because of auspicious improvement in properties. The main purpose of this research work was to study the influence of addition of SiO2 particles on corrosion performance of Ni-B coated surfaces which has not been reported so far. Coatings of Ni-B and Ni-B-SiO2 were deposited on steel through electrodeposition process. The microstructural (SEM) analysis confirms the formation of uniform, dense nodular structure in coatings of Ni-B and Ni-B-SiO2 . Surface examination (AFM) discloses that the addition of SiO2 increases surface smoothness. Electrochemical characterization of the synthesized coatings indicates that Ni-B-SiO2 composite coatings demonstrate better anticorrosion properties when compared to Ni-B. Enhanced corrosion performance may be ascribed to reduction in the active surface area and grain size refinement which reduces the porosity by the addition of inactive SiO2 particles.Scopu
Novel Ni based duplex coatings for anticorrosion applications
No full textNi-B/Ni-P-CeO2 duplex coatings containing inner Ni-B layer were synthesized on mild steel substrate through the electrodeposition process. The structural, surface and electrochemical properties of the duplex coatings in their as synthesized condition were compared with Ni-P, Ni-B and binary Ni-B/Ni-P duplex coatings to demonstrate the improved performance of Ni-B/Ni-P-CeO2 duplex coatings. The structural analysis (XRD) indicates that the developed coatings exhibit amorphous behavior. The SEM and AFM studies indicate that Ni-B/Ni-P-CeO2 duplex coatings have less surface defects and more defined nodular structure compared to Ni-P, Ni-B and NiB/Ni-P duplex coatings. However, these coatings show an increase in surface roughness which may be attributed to the incorporation of CeO2 ceramic particles used as reinforcement. The Ni-B/Ni-P-CeO2 duplex coatings present superior anticorrosion properties compared to Ni-B and duplex Ni-B/Ni-P coatings. Owing to tempting properties, Ni-B/Ni-P-CeO2 duplex coatings may be considered as potential candidate for oil and gas industry.This research work was supported by the Director Center for Advanced Materials (CAM), Qatar University, Doha, Qatar.Scopu
Enhanced electrochemical and mechanical performance of BN reinforced Ni-P based nanocomposite coatings
No full textAdequate corrosion protection and improved mechanical properties are necessary requirements to overcome operational costs in the industries. Ni-P based coatings are known to possess better superior corrosion resistance than its counterparts. Boron Nitride nanoparticles (BNNPs) are well known refractory material with higher hardness and chemically inert nature suitable for reinforcement. In the current investigation, the effect of incorporation and increasing concentration of BNNPs in Ni-P matrix in thoroughly investigated in terms of mechanical and electrochemical performances. Successful incorporation of BNNPs within the Ni-P matrix was achieved by employing tailored Watts bath and optimized deposition parameters. The addition and increment of BNNPs reveal a significant impact on the characteristics of pure Ni-P coatings. Improvement in the structural, morphological, mechanical and corrosion behavior of BNNPs reinforced nanocomposite coatings can be ascribed to uniform incorporation of BNNPs in the deposit leading to the dispersion hardening effect that enhances strength to the coating improving surface hardness up to 58 % in comparison to pure Ni-P coating. Moreover, reduction in the active area caused by inert BNNPs leads to the improvement in corrosion resistance properties with protection efficiency (PE%) reaching up to 95 % for Ni-P-1.5 g/L BN nanocomposite coating in comparison to the bare mild steel substrate. BNNPs reinforced Ni-P based nanocomposite coatings provide a possible choice for their application in many industries like in the aerospace, automotive, marine, oil and gas industry.Other InformationPublished in: Diamond and Related MaterialsLicense: http://creativecommons.org/licenses/by/4.0/See article on publisher's website: https://dx.doi.org/10.1016/j.diamond.2022.109454</p
Synthesis and Performance Evaluation of Pulse Electrodeposited Ni-AlN Nanocomposite Coatings
No full textThis research work presents the microscopic analysis of pulse electrodeposited Ni-AlN nanocomposite coatings using SEM and AFM techniques and their performance evaluation (mechanical and electrochemical) by employing nanoindentation and electrochemical methods. The Ni-AlN nanocomposite coatings were developed by pulse electrodeposition. The nickel matrix was reinforced with various amounts of AlN nanoparticles (3, 6, and 9 g/L) to develop Ni-AlN nanocomposite coatings. The effect of reinforcement concentration on structure, surface morphology, and mechanical and anticorrosion properties was studied. SEM and AFM analyses indicate that Ni-AlN nanocomposite coatings have dense, homogenous, and well-defined pyramid structure containing uniformly distributed AlN particles. A decent improvement in the corrosion protection performance is also observed by the addition of AlN particles to the nickel matrix. Corrosion current was reduced from 2.15 to 1.29 μA cm−2 by increasing the AlN particles concentration from 3 to 9 g/L. It has been observed that the properties of Ni-AlN nanocomposite coating are sensitive to the concentration of AlN nanoparticles used as reinforcement.</jats:p
The new year's festivals and the shrine of Ali Ibn Abi Talib Sy Mazar-I-Sharif, Afghanistan
No full textThis study examines the customs and origins of three spring festivals at the shrine of 'Ali b. Abi Talib, Mazar-i Sharif, Afghanistan; namely Nauroz, Janda Bala and Gul-i Surkh. Since these festivals are not part of the Islamic religious calendar, we seek to locate their origins in the pre-Islamic religions of Iran and record the contemporary traditions of these festivals. Since the festivals are assimilated to a shrine dedicated to the fourth Caliph of
Sunni Islam, we examine the processes which gave rise to this juxtaposition and how it came about that this shrine came to be considered a rival to Najaf.
The Sa1juq and Timurid discovery narratives are examined (Chapters 1-2) in their wider religious and cultural context, followed by an examination of Afghan folklore related to Nauroz and the pre-Islamic religious traditions of Bactria (Chapters 3-4). We conclude that an important impetus for the founding of this shrine is the fact that, until the arrival of Islam, Bactra had been the paramount pilgrimage and cult centre of the region. Over the millennia, whilst the dominant religious tradition had changed, Bactra adapted to such ideological fluctuations in order to maintain its dominance of the. lucrative pilgrimage
traffic. Marginalised by Islam, whose heroes and foci of pilgrimage lay in the Arab world, the alleged discovery of the body of Hazrat 'Ali at the site, provided an acceptable Islamic framework for the revival, or continuation, of indigenous Bactrian New Year customs.
Our examination of Gul-i Surkh, or 'Red Rose', festival (chapters 5-6) finds a parallel in the Annenian Vardavar festival. Originally this festival appears to have been derived from a blending of Iranian and Babylonian religion in Bactria, namely the cults of Anahita, Adonistrammuz and custoins associated with the Iranian hero, Siyawush. Janda Bala (Chapter 7), on the other hand, appears to be rooted in ancient Vedic and Shamanistic tradition. All three festivals, though, we argue, also represent different aspects of ancient Indo-Aryan and Babylonian fertility rites connected with the spring and vernal equinox
Enhancement of mechanical and corrosion resistance properties of electrodeposited Ni–P–TiC composite coatings
No full textIn the present study, the effect of concentration of titanium carbide (TiC) particles on the structural, mechanical, and electrochemical properties of Ni–P composite coatings was investigated. Various amounts of TiC particles (0, 0.5, 1.0, 1.5, and 2.0 g L−1) were co-electrodeposited in the Ni–P matrix under optimized conditions and then characterized by employing various techniques. The structural analysis of prepared coatings indicates uniform, compact, and nodular structured coatings without any noticeable defects. Vickers microhardness and nanoindentation results demonstrate the increase in the hardness with an increasing amount of TiC particles attaining its terminal value (593HV100) at the concentration of 1.5 g L−1. Further increase in the concentration of TiC particles results in a decrease in hardness, which can be ascribed to their accumulation in the Ni–P matrix. The electrochemical results indicate the improvement in corrosion protection efficiency of coatings with an increasing amount of TiC particles reaching to ~ 92% at 2.0 g L−1, which can be ascribed to a reduction in the active area of the Ni–P matrix by the presence of inactive ceramic particles. The favorable structural, mechanical, and corrosion protection characteristics of Ni–P–TiC composite coatings suggest their potential applications in many industrial applications
