1,720,983 research outputs found
Magnetic nano-adsorbents applications and modelling for green environmental remediations / Muhammad Abdur Rehman
Full text linkThis work describes some general procedures for the preparation, characterization of adsorbents, CuFe2O4, CuCe0.1Fe2O4, CuCe0.2Fe2O4, CuCe0.3Fe2O4, CuCe0.4Fe2O4, CuCe0.5Fe2O4, CuCe0.2Fe2O4-rGO, POCS (X=4.75), POCS (X=2.36), POCS (X=1.18), POCS (X=0.6), POCS (X=0.3), POCS (X=0.15) and their application for the decontamination of hydrological samples in an environment of high competitions for available active sites on the surface of adsorbents. A detailed characterization and analysis were carried out by the Fourier Transform Infrared spectroscopy (FTIR), Raman spectroscopy, X-ray Diffraction (XRD), BET surface area, particle size analyzer, Zeta Potential (ZP), Thermal gravimetric analysis (TGA & DTA), Field emission scanning electron microscopy (FESEM), Transmission Electron microscopy (TEM), Nuclear magnetic resonance (NMR), High performance liquid chromatography (HPLC), ion chromatography (IC), Inductively coupled mass spectroscopy (ICPMS), Electrochemical impedance spectroscopy (EIS), Linear scan cyclic voltammetry (LSCV) and UV-Visible spectroscopy that revealed the formation of impurity free magnetic adsorbents. The adsorbents were applied for the green environment remediation of heavy metals, anionic species and organophosphorus acephate. The properties of these synthetic adsorbents were fine-tuned by the facile process of doping rare earths, monitored by Autolab PGSTAT 302N and NOVA 1.10 software. Response surface methodology (RSM) for optimum adsorption and central composite design (CCD) was selected to study the main effects and interaction effects of various controlling parameter such as Adsorbent dose (g L-1), mixing speed (r/min), temperature (oC) and initial concentration (mgL-1). The nature of all the interaction was explained by a number of isotherms and kinetic models. Kinetic models include, pseudo first order, pseudo second order, Banghams, intra-particle diffusion, while the equilibrium models such as Langmuir, Freundlich, Temkin, Dubenin Redushkvich (DR), and Flory Huggins (FH). The equilibrium and kinetic models were tested for goodness of fit between the observed and model predicted adsorption capacities (Qe) to explain the interaction removal mechanisms. The results were further used to prepare adsorbents, characterize, apply and check for the best fit model that explains the adsorption process. The series of CuCexFe2-xO4 (x=0.0 to 0.5) retained magnetic properties for fluoride adsorption with coefficient values of X1(74.29), X2 (25.31), X3 (36.99) and X4 (8.31) respectively. The natural POCS displayed Arsenic adsorption coefficient X1(1.62), X2 (1.81), X3 (0.80) and X4 (3.10). The isotherms results of Acephate show the value of Qe (Langmuir), 11.23 mgg-1 or 10.67 mgg-1 at 293K and 313K respectively. The pseudo second order kinetic model give best fit to the results (R2 = 0.998), and the value of Qe (pseudo second order) were 12.427 mgg-1and 12.280 mgg-1 at 293K and 313 K respectively. The magnetic separations, dopant facilitated dispersions and graphene layers provided some novel series of energy efficient adsorbent. The design of experiments strategy with various statistical standards designs helps optimize the adsorption conduction with minimal number of experiments, reducing the cost and time of research and development in green environmental remediation
خطبہ جمعہ کی دینی اور فقہی اہمیت: ایک تجزیاتی مطالعہ : The Significance of Friday Sermon (Khutbah Jumu'ah) in Islam: Theological Analysis
No full textFriday congregational prayer (Salat al-Jumma) holds paramount importance in Islamic worship, and the Friday sermon (Khutbah-e-Jumma) is an integral aspect of this ritual. Originating in the early centuries and transmitted in Arabic, the legitimacy and jurisprudential rulings regarding the Friday sermon have been subjects of differing opinions among Islamic scholars. These opinions range from its obligatory nature to its permissibility. This paper delves into the significance of the Friday sermon, arguing that it serves not only as a direct adjunct to prayer but also as a means of spiritual purification. Hence, it advocates considering diverse jurisprudential perspectives and emphasizes the facilitation of spiritual purification and communal guidance within the Muslim community. Through an examination of evidences and theological reasoning, this paper aims to shed light on the broader theological and legal significance of the Friday sermon in Islam
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
سیدنا سعید بن زید: دینی زندگی کا ایک نمونہ: Syedina Saeed Bin Zaid: An Exemplar of Spirituality
No full textSyedina Saeed Bin Zaid, a prominent figure in early Islamic history, stood as a beacon of unwavering faith and staunch monotheism amidst the idolatrous society of pre-Islamic Arabia. This paper delves into the life and legacy of Syedina Saeed Bin Zaid, exploring his steadfast commitment to the pursuit of truth and his rejection of idol worship. Born into the tribe of Adi, Syedina Saeed Bin Zaid was renowned for his rejection of polytheism and his quest for monotheism. Despite facing persecution and ridicule, he remained resolute in his beliefs, earning the admiration of those who witnessed his unwavering commitment to the truth. The paper examines Syedina Saeed Bin Zaid's encounters with various religious figures and his relentless search for guidance, which ultimately led him to reject the idolatry of his society and embrace the path of monotheism. It highlights his encounters with the Prophet Muhammad (peace be upon him) and the profound impact he(ﷺ) had on his spiritual journey. Furthermore, the paper explores the poetic eulogy written by Waraqah bin Nawfal, a close associate of Zaid, lamenting his untimely demise and celebrating his unwavering dedication to truth and monotheism. In conclusion, the paper reflects on the enduring legacy of Zaid bin Amr bin Nufail, whose steadfastness and conviction serve as an inspiration for believers seeking truth in the face of adversity. His life exemplifies the timeless struggle for faith and the pursuit of righteousness in the quest for divine guidance
اجماع : تعارف و مبادیات: CONSENSUS: INTRODUCTION AND BASICS
No full textConsensus (Ijma) is an important component of Islamic jurisprudence. In the sources of Sharia, consensus ranks after the Quran and the Sunnah. The agreement of the mujtahids (Jurists) and scholars of the ummah in sub issues of religion is called consensus and this is Hujjat. Consensus is not acceptable in the matters of principle. People agreeing on an issue is not consensus. In order to hold consensus, it is necessary that the era of the Prophet (peace and blessings of Allah be upon him) must be passed because it is not held in the presence of the Prophet.
There are basically two types of consensuses. First one is Verbal or Practical consensus: That is, the people who consensus should make it clear by their words or actions. Second one is Silent consensus: That is, Let the words or actions of some of the scholars of consensus be made public and the rest of the people should avoid talking about it
Antenna design and optimisation for UHF glacial environmental sensor networks
Full text linkOur planet’s ice masses play an important role in regulating numerous natural phenomena vital to keep our planet habitable by humans as well as other living species. Since few decades, global climate changes are probably responsible for an increased melt rate of the ice masses causing catastrophes. It is therefore desirable to monitor our planet’s ice masses for predicting catastrophes and timely initiating disaster management measures. This monitoring can also provide scientific evidence for supporting anti-climate change efforts. This research contributes to a joint UCL (University College London) – BAS (British Antarctic Survey) project that aims to develop and deploy an Environmental Sensor Network (ESN) at the Thwaites glacier, Antarctica. Glacial ESNs reported in the last two decades are reviewed, focusing on the antenna types used. A link budget framework for designing such antenna systems is presented. As an example, the framework has been used to design an antenna system for deployment at the Thwaites glacier, Antarctica. Design details of six circularly polarized (CP) antennas, one for the englacial sensor probes and five for supraglacial surface receivers are presented. The probe antenna is a 3D bent cross dipole that fits within a borehole of 8 cm diameter while providing a 1 dBic gain at 433 MHz in ice. The other five antennas are printed ones made for use with glacier surface receivers to receive information transmitted by the englacial sensor probes. Out of five, three are cross dipole antennas, while the remaining two are of Archimedean spiral type. All these six antennas provide 3 dB beamwidths of at least 50º in the xz and yz vertical planes catering for transmitter-receiver antenna misalignments caused by extended deployments. The printed cross dipole versions 1 and 2, and the half ring shaped cross dipole antennas for surface receivers provide realized gains of 6.1 dBic, 5.9 dBic, and 5.9 dBic respectively with a quarter wave reflector. The version 2 antenna provides size reduction at the cost of minor gain loss compared to the version 1 antenna. The half ring cross dipole antenna provides improvements in terms of a lower profile, wider 3 dB beamwidth, smaller axial ratio, and purer polarization over all the other antennas developed for use with surface receivers. The axial ratios of all four cross dipole antennas remained below 1.1 dB within the 330-580 MHz band while the co-polarizations remained adequately stronger than the cross polarizations within a 40º beamwidth in both the vertical planes. The spiral antenna version 1 provides a gain of 7.4 dBic at 433 MHz and a -10 dB fractional bandwidth of 47% in snow. Through some design modifications, the version 2 spiral antenna provides significant improvements in the antenna’s reflection coefficient, gain, total efficiency, and axial ratio over the version 1 spiral antenna. None of the previous works used these antenna types for the said applications. The previous works used helical, coil ferrite, and Dielectric Resonator antennas for the sensor probe. Types of antennas previously used with surface receivers included Yagi, helical, non-printed cross dipole, and log periodic dipole array. Lastly, the feasibility of 433 MHz band has been investigated for communication ranges up to 2300 metres through ice. Previous works used lower frequencies like 30 MHz, and 151 MHz to achieve such ranges
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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