217 research outputs found
Removal of Heavy Metals from Wastewater Using Novel Polydopamine-Modified CNTs-Based Composite Membranes
No full textThe presence of major heavy metals including Pb2+, Cu2+, Co2+, Ni2+, Hg2+, Cr6+, Cd2+, and Zn2+ in water is of great concern because they cannot degrade or be destroyed. They are toxic even at very low concentrations. Therefore, it is necessary to remove such toxicants from water. In the current study, polydopamine carbon nanotubes (PD-CNTs) and polysulfone (PS) composite membranes were prepared. The structural and morphological features of the prepared PDCN composite membranes were studied using FTIR, XRD, SEM, and EDS. The potential application of PDCNs for heavy metal removal was studied for the removal of Pb2+, Cr6+, and Cd2+ from wastewater. The maximum removal efficiency of 96.1% was obtained for Cr6+ at 2.6 pH using a composite membrane containing 1.0% PD-CNTs. The removal efficiencies decreased by 64.1 and 73.4, respectively, by enhancing the pressure from 0.50 up to 0.85 MPa. Under the same circumstances, the percentages of Pb+2 removal at 0.49 bar by the PDCNS membranes containing 0.5% and 1.0% PD-CNT were 70 and 90.3, respectively, and decreased to 54.3 and 57.0, respectively, upon increasing the pressure to 0.85 MPa. The results showed that PDCNS membranes have immense potential for the removal of heavy metals from water
Electrosynthesis and Characterization of Novel {CNx}-{HMMT} Supported Pd Nanocomposite Material for Methanol Electro-Oxidation
No full textIn the current research work, palladium (Pd) nanoparticles were electrochemically deposited on a nitrogen doped montmorillonite (CNx-MMT) support using the underpotential deposition (UPD) method. The prepared Pd based composite electrode was studied as an electrocatalyst for methanol fuel oxidation. The catalysts and the supporting materials montmorillonite, acid activated montmorillonite, and nitrogen doped montmorillonite (MMT, HMMT and CNx-HMMT) were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) and electrochemical characterization by cyclic voltammetry (CV). The results indicated that Pd supported on CNx-HMMT possesses enhanced electrocatalytic activity and stability compared to commercial Pd/C, which was attributed to its higher electrochemical surface area (ECSA) (23.00 m(2) g(-1)). The results demonstrated the potential application of novel Pd/CNx-HMMT composite nanomaterial as electrocatalysts for methanol electrooxidation in direct methanol fuel cells (DMFCs)
Novel Sepiolite Reinforced Emerging Composite Polymer Electrolyte Membranes for high Performance Direct Methanol Fuel Cells
No full textMethanol permeation is the main issue of Nafion membranes when they are used as a polymer
electrolyte membrane (PEM) in direct methanol fuel cells (DMFCs). In the current study, novel
nanocomposite polymer membranes are prepared by the integration of surface-modified sepiolite
(MS) in polyvinylidene fluoride grafted polystyrene (PVDF-g-PS) copolymer as PEM in DMFCs.
Sepiolite surface is chemically modified using vinyltriethoxysilane and analyzed by fouriertransform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) and scanning electron
microscopy (SEM). Nanocomposite PVDF-g-PS/MS membranes are prepared by phase inversion
technique and subsequently treated with chlorosulfonic acid to induce sulfonic acid (SO3H) active
sites at the membrane surface. The prepared nanocomposite membranes (S-PPMS) are analyzed
for their physicochemical characteristics in terms of water uptake percentage, cation exchange
capacity (CEC), proton conductivity (σ), and methanol permeability. MS dispersion in the
copolymer matrix is proved through morphological SEM examination. The S-PPMS membranes
exhibit increased proton conductivity due to the presence of well-dispersed MS and surface
functional –SO3H groups. A peak power density of 210 mWcm−2 is recorded for S-PPMS10 at
110 °C which is higher than the output obtained from Nafion-117. These promising results indicate
the potential utilization of prepared nanocomposite PEMs for DMFC application
THE PROBLEM OF UNIVERSAL SALVATION IN THE TEACHING OF RASHID RIDA
No full textThe problem of salvation of non-Muslims is a crucial element in the discourse of Islamic modernism. It was no less important for such Islamic thinkers of the classical period as Ibn Qayyim al-Jawziyya and Abu Ḥamid al-Ġazali. The attention of the author of the present paper focuses on understanding the problem of salvation in the teaching of Muhammad Rashid Rida, who was one of the key participants in the modernist movement in Islam. Being a representative of “intellectual salafism”, Rashid Rida proposes a solution for the issue of salvation that comes as an alternative for traditionalist views predominating in Sunni Islam. The present paper serves to prove that Rida’s quite peculiar solution is deeply rooted in Islamic tradition. In particular, it relates to viewpoints of al-Jawziyya and al-Ġazali, which deflect from mainstream. Similar to many other Islamic modernists (we can consider as part of them proponents of Jadidism, such as M. Bigiev, Z. Kamali, R. Fahreddin and others), the main although not the only argument of Rida is based on the Quranic idea of all-embracing Divine grace. In his analysis of Rida’s position, the author notes that the former does not lean towards the liberal variant of Islamic reformism that supposes religious pluralism as one of its basic ideas. Advocating the superiority of Muhammad’s message, the Egyptian thinker adhered to a specific form of soteriological inclusivism that differs from religious pluralism. According to Rida, the main criterion for one’s salvation is whether one was touched upon by undistorted Islamic message or not. Rida was convinced that Gehenna only awaits those non-Muslims who received undistorted Islamic message, clearly understood its Divine source and thenintentionally rejected it. But even they may be redeemed, as God is not obligated to act on his declared threat
Microbial Degradation of Plastics:New Plastic Degraders, Mixed Cultures and Engineering Strategies.
No full textPlastic and plastic recycling/degradation has been in the spotlight during last decade, due to its increasing waste accumulation in all world’s ecosystems and the huge challenge deriving from micro-plastic pollution. Therefore, different strategies are under investigation, trying to cope with this problem. Although depolymerisation of plastics by chemico-physical methods seems to represent a promising technology, biodegradation by microorganisms has been raising interest in recent years. In fact, new studies regarding the possibility of engineering specific plastic-degrading enzymes have obtained much attention by the media, due to the hope of overcoming one of the main bottlenecks of this technology: the extremely slow conversion rates. In the following chapter, we will be discussing two important strategies, which are expected to help overcoming these bottlenecks: genetic engineering to improve the catalytic activity of plastic-degrading enzymes and the development of syntrophism and cross-feeding mechanisms in enriched microbial communities. Finally, the potential of ongoing studies and future trends will also be discussed
Microbial Remediation of Pesticide Polluted Soils
No full textThe increasingly rapid growth of both, population- and food demands has driven a research race in food production efficiency through the last century, which has made the pesticide use seemingly unavoidable. However, many pesticides are very persistent and tend to accumulate in the ecosystem, often threatening biodiversity and public health. Although abiotic degradation of these compounds plays a role in many cases, the biodegradation of pesticides by microorganisms is usually the most important and dominant process. This natural degradation varies from site to site, depending on several factors, but it can be favourably improved by applying techniques such as bioaugmentation and biostimulation, which can lead to the cleaning-up of pesticide-contaminated soils. The present chapter introduces the most recent findings in the field of bioremediation of pesticides, critically discussing the main bottlenecks and how to overcome them. Factors affecting biodegradation of pesticide-polluted soils are presented, with a clear focus on the enrichment and selection strategies for relevant microbial strains. Case studies on bioaugmentation of contaminated soils and future trends are also described, including the microbial degradation of pesticide mixtures through mixed culture technology.<br/
Mapping the policy, policing and positioning of street vending in New York City
No full textThesis: M.C.P., Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2016.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references.tolerance of their activities; governments often allow street vendors in certain areas of the city, while relocating street vendors from sidewalks in others. In the absence of meaningful, in-depth datasets on urban informality, studies investigating this variation have had to rely on case studies, anecdotal material and qualitative neighborhood comparisons. As a result, there have been no large-scale empirical studies undertaking city-wide analysis of the policing of urban informality. This thesis overcomes such limitations by using a mix of administrative data, mobile sensing, GIS mapping and qualitative methods to uncover informality's relationship with the state and the larger urban fabric in New York City. Through visualization and empirical analysis of the enforcement landscape vis-à-vis socioeconomic variables in New York, this project highlights the underlying impulses that lead to uneven regulatory outcomes: disparate claims on urban citizenship and a city's move towards more privatized urbanism. At the same time, my methodology allows this thesis to display the unique interactions street vending has with each neighborhood's socio-spatial environment, resulting in the creation of diverse vending cultures. By recognizing this vibrancy and detangling the determinants of the spatial landscape of vending rule enforcement, this thesis advocates for a fairer regulatory schema for informal commerce.by Rida Qadri.M.C.P
The Life of Hedonism from the Perspective of Al-Tabari and Sayyid Muhammad Rashid Rida (Comparative Study of Tafsir Surah Ali Imran: 14)
No full textThe Qur'an not only tells us about prohibitions and commands, but also talks about the problems of the lives of previous people. Among them are illustrated by the human lifestyle that prioritizes pleasure and physical luxury. Based on the hedonistic lifestyle, it certainly has 'ibrah that can be learned if an in-depth study of the life of hedonism is carried out. The author wants to examine the life of hedonism from the perspective of al-Tabari and Sayyid Muhammad Rasyid Rida. This paper uses a qualitative approach that is classified into library research with library materials, especially Jami' al-Bayan fi Ta'wil Ayi al-Qur'an and Tafsir al-Manar and uses comparative data analysis. The conclusion in this paper is that the life of hedonism according to al-Tabari and Sayyid Muhammad Rasyid Rida is an excessive human lifestyle and indulges in lust in reaching the pleasures of the world. The similarities and differences according to these two mufassirs are almost the same in interpreting the life of hedonism in surah Ali Imran verse 14 that Allah SWT makes beautiful in human views of the pleasures of the world, namely women, children, large assets of gold and silver, selected horses, livestock and rice fields. Sayyid Muhammad Rasyid Rida besides agreeing with Imam al-Tabari, he added that human love for the beauty and pleasure of the world is not only specific to the Jews, but is general
Protease production by Brevundimonas sp. and Trabulsiella guamensis isolated from contaminated soil
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