136 research outputs found

    Correction: Ultra-fast and highly sensitive enzyme-free glucose biosensing on a nickel–nickel oxide core–shell electrode

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    Correction for ‘Ultra-fast and highly sensitive enzyme-free glucose biosensing on a nickel–nickel oxide core–shell electrode’ by Halima Begum et al., RSC Adv., 2017, 7, 3554–3562.</p

    Sustainability Awareness Week 2021: esa New York presents Halima Garrett of Threads of Habit

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    In this workshop, master-thrifter and designer, Halima Garrett, will describe the importance and craft of upcycling. She will give advice for identifying materials that can be upcycled and take the audience through a short upcycling tutorial to show how it is done in a way that minimizes waste and maximizes utility and style. Ms. Garrett is the founder of Threads of Habit, a New Jersey-based outlet offering bold, eccentric, and unique vintage pieces.Sustainability is a key component of FIT’s mission and is embedded in the college’s curriculum and operations. During virtual Sustainability Awareness Week, we invite our community to learn about recent innovations from leaders in the industry, FIT students, faculty, staff, and alumni; experience FIT’s efforts to make a positive impact on the earth; and discover new ways to live with a smaller footprint

    Improving access to housing for low-income communities in Dhaka: From rhetoric to reality in community participation

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    The research explores how community participation can address affordable housing problems of the poor in Dhaka. The research, based on extensive interviews, community focus groups and household surveys in different Dhaka slums, identifies the limiting factors to promote community participation in affordable housing creation. In Dhaka housing options for poor are currently limited to affordable shelters in informal settlements. Public housing programs have failed to reach the poor and meet affordability levels due to a number of factors including lack of beneficiary participation. Beneficiary participation, though widely recognized for success in housing initiatives, often deteriorates in process of implementation into mere involvement, not reflecting community needs and aspirations and thus failing to meet its core objectives. This research identified the most significant impediments as well as opportunities to advance participation in their own housing provisions in Dhaka city

    Characterization and Performances of Nanosized Bi-metallic Fe-based Zeolite Catalysts during Selective Catalytic Reduction (SCR) of NO by NH3

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    因應日益嚴重的一氧化氮汙染與更嚴謹之法律規範,相關於一氧化氮(DeNOx)去除技術的研發頗受重視,本研究論文即針對鐵基(Fe-based) ZSM-5沸石觸媒在選擇性催化還原(Selective Catalytic Reduction; SCR)反應之應用效能進行系列性探討,包括觸媒合成方法,物理化學特性鑑定及其在SCR反應之效能與機理等做深入比較與討論。論文內容主要由五個主要章節目次所構成。首章概略敘述現行所使用去除一氧化氮製程工序之相關策略、反應機理、觸媒種類及其相關特性以及本研究之目的等;第二章主要描述本研究論文之研究架構與實驗流程,並詳述觸媒合成程序,物理性質與化學性質之鑑定技術以及去除一氧化氮反應效能測試之設備與實驗步驟等;隨後第三、四、五章之內容則為本研究論文之結果與討論部分。第三章的主題在於比較並討論單金屬與雙金屬鐵基沸石觸媒之合成方式對SCR反應效能之影響。第四章則著重於探討鑭系金屬元素(Ce, Pr, Nd, Sm)摻雜之鐵基沸石觸媒之物化特性比較及其應用於一氧化氮去除的效能差異。第五章則針對觸媒擔體(即ZSM-5沸石)中矽鋁組成比例對SCR反應活性之影響進行討論。第六章為本研究論文之總結及未來研究展望。本研究論文所合成之觸媒皆經過系統性的鑑定,所使用的物化分析研究包含ICP-MS、XRF、XRD、BET、FE-TEM、H2-TPR、XPS、EPR、NH3-TPD、pyridine-FTIR以及固態27Al/31P MAS NMR等。研究發現雙金屬鐵基(CeFe-ZSM-5)沸石觸媒去除一氧化氮效能上普遍優於單金屬鐵基(Fe-ZSM-5)沸石,反應在350-500 oC下,去除率可達94%以上。吾人將雙金屬鐵基沸石觸媒優異的SCR反應活性歸因於由沸石擔體本身具備的強布朗斯特酸(Bronsted acidity)以及該單體在摻雜Fe、Ce等金屬後所引發之超強路易士酸(Lewis acidity)兩者的協同效應所致。In view of the stringent global regulation and increasing R&D demands in NOx removal (DeNOx), this thesis focuses on synthesis, characterization, and applications of Fe-based H-ZSM-5 zeolite catalysts for selective catalytic reduction (SCR) of NO by NH3. This thesis mainly consists of five chapters: Chapter 1 provides an overview and the chemistry, strategy, mechanism, and solid acid catalysts involved in a DeNOx process. Chapter 2 contains experimental details, including catalyst preparation methods, characterization techniques, and experimental procedures invoked during this study. Chapter 3 compares the SCR performances of mono- and bi-metallic Fe-based ZSM-5 catalysts prepared by different methods. Chapter 4 describes the syntheses and SCR performances of Lanthanide metal (Ce, Pr, Nd, and Sm)-incorporated Fe-based ZSM-5 catalysts prepared by reflux method. Chapter 5 summarizes the effect of Si/Al ratio of zeolite support on SCR performances of CeFe-ZSM-5 catalysts prepared by impregnation method. The catalysts so prepared were characterized by a variety of analytical and spectroscopic techniques, such as ICP-MS, XRF, XRD, BET, FE-TEM, H2-TPR, XPS, EPR, NH3-TPD, Pyridine-FTIR, and solid-state 27Al and 31P MAS NMR. It is conclusive that bimetallic catalysts (such as CeFe-ZSM-5) normally exhibit higher NH3-SCR activity (> 94%) over the temperature range of 350-500 oCthan mono-metal catalysts (such as Fe-ZSM-5). The superior SCR activity observed for the bimetallic catalysts has been attributed, for the first time, to the synergistic effect of Bronsted acidity originated from the zeolite support and strong Lewis acidity induced by the incorporated metals.Contents Page Acknowledgements i 摘要 iv Abstract v Contents vi Figure contents x Scheme contents xv Table contents xvi Chapter 1 Introduction 1 1.1 Background and Overview 1 1.2 NOx Removal (DeNOx) 2 1.2.1 Selective non-catalytic reduction (SNCR) 3 1.2.2 Non-selective catalytic reduction (NSCR) 3 1.2.3 Selective catalytic reduction (SCR) 3 1.3 Catalysis and SCR Chemistry 4 1.4 DeNOx Catalysts 6 1.5 Zeolites 7 1.5.1 Introduction 7 1.5.2 Structures of zeolites 7 1.5.3 Catalytic properties of zeolites 9 1.5.4 MFI type of Zeolite, ZSM-5 11 1.6 Mechanism of NH3-SCR over H-ZSM-5 Catalyst 12 1.7 Motivation of Research 15 1.8 References 17 Chapter 2 Experimental 21 2.1 Chemicals 21 2.2 Preparation of Fe-Based ZSM-5 Catalysts 21 2.2.1 Impregnation method 22 2.2.2 MO-CVD method 22 2.2.3 CVD method 23 2.2.4 Modified CVD method 23 2.2.5 Reflux method 24 2.3 Selective Catalytic Reduction of NO by NH3 25 2.3.1 Experimental apparatus 25 2.3.2 Experimental procedures 25 2.4 Characterization techniques 27 2.4.1 Inductively coupled plasma–mass spectroscopy (ICP-MS) 28 2.4.2 X-ray fluorescence spectroscopy (XRF) 29 2.4.3 X-ray diffraction (XRD) 30 2.4.4 X-ray photoelectron spectroscopy (XPS) 31 2.4.5 N2 adsorption-desorption isotherms 32 2.4.6 Field emission transmission electron microscopy (FE-TEM) 33 2.4.7 Temperature programmed reduction (TPR) 34 2.4.8 Electron paramagnetic resonance (EPR) 35 2.4.9 Solid-state nuclear magnetic resonance spectroscopy (SS-NMR) 35 2.5 Acidity Characterization Methods 36 2.5.1 Temperature programmed desorption of ammonia (NH3-TPD) 39 2.5.2 Fourier transform infrared spectroscopy of adsorbed pyridine (pyridine-IR) 40 2.5.3 Solid-state 31P NMR of adsorbed phosphine oxides 41 2.6 References 44 Chapter 3 SCR Performances of Mono- and Bi-Metallic Fe-Based ZSM-5 Catalysts Prepared by Different Methods 47 3.1 Introduction 47 3.2 Results and Discussion 50 3.2.1 SCR performances of Fe-ZSM-5 catalysts prepared by different methods 50 3.2.1.1 Structural property 50 3.2.1.2 Surface property 54 3.2.1.3 SCR performance 63 3.2.1.4 Acid property 66 3.2.2 SCR performances of CeFe-ZSM-5 catalysts prepared by different methods 76 3.2.2.1 Structural property 76 3.2.2.2 Surface property 79 3.2.2.3 SCRperformance 83 3.2.2.4 Acid property 85 3.3 Conclusions 95 3.4 References 97 Chapter 4 SCR Performances of Lanthanide Metal-Incorporated Fe-Based ZSM-5 Prepared by Reflux Method 103 4.1 Introduction 103 4.2 Results and Discussion 107 4.2.1 Structural property 108 4.2.2 SCR performance 116 4.2.3 Surface property 118 4.2.4 Acid property 120 4.2.4.1 NH3-TPD 121 4.2.4.2 Pyridine-IR 124 4.2.4.3 31P MAS NMR of adsorbed TMPO 129 4.3 Conclusions 137 4.4 References 138 Chapter 5 Effect of Si/Al Ratio of the Zeolite Support on SCR Performances of CeFe-ZSM-5 Catalysts Prepared by Impregnation Method 143 5.1 Introduction 143 5.2 Results and Discussion 146 5.2.1 Structural property 146 5.2.2Surface property 150 5.2.3 SCR performance 163 5.2.4 Acid property 165 5.3 Conclusions 187 5.4 References 189 Chapter 6 Summary and Perspectives 19

    Commodifying multicultures: urban regeneration and the politics of space in Spitalfields

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    PhDSpitalfields, within close distance to the City of London. has been subject to intense regeneration and gentrification in recent years. This thesis investigates the use of culture in promoting urban regeneration. This thesis analyses the role of multiculturally based regeneration in Spitalfields and assesses the possibilities for civic engagement in a number of recent regeneration initiatives. I argue that regeneration in Spitalfields has taken a cultural turn, and that a new set of discourses is present in regeneration practices. These new forms of regeneration practices demand a different kind of interpretation. This distinctiveness in policy consists of the use and mobilisation of 'culture' and 'multicultural capital' as tools for regeneration. Most notably the study's timing during a phase of intense change sets it apart as one of the few studies undertaken of the complex relationship between the new cultural industries, multicultural capital and the practice of selling places. The study's theoretical framework draws from a range of inter-disciplinary literature on urban space. cultural politics and feminist theory. In capturing a series of moments that took place between 2000 and 2003,1 analyse a range of regeneration initiatives but focus closely on three case studies: the construction of Banglatown in Brick Lane, the Rich Mix Centre for London, and the annual street festivals/melas that took place in 2001 and 2002. I focused on two sets of respondents - young people and young Muslim women whose experiences of regeneration raise unsettling questions of inclusion and exclusion in/through space. Cumulatively these sites are key examples of Spitalfields' multi-cultural spaces. They extend a sense of promise to all its residents in the hope of a cosmopolitan future or progressive city politics. The tensions from these cultural strategies pose challenges for thinking about the place of citizenship in urban multicultures. The research findings point to a sophisticated understanding of the relationship of ethnicity, gender, commerce and public space

    The traumatic experience and sexual violence in Halima Bashir’s tears of the desert

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    El objetivo principal de este trabajo se centra en el análisis de la experiencia traumática de la escritora sudanesa Halima Bashir en su obra autobiográfica Las lágrimas del desierto. A la hora de analizar la obra hemos tenido en cuenta los postulados del trauma para entender la función de la memoria como herramienta a partir de la cual la memoria individual de Halima se convierte en memoria colectiva para los sudaneses oprimidos en Darfur. La obra de Halima, aunque se centra en la experiencia de violación de un individuo, implica un mensaje político y un testimonio histórico de las atrocidades en Darfur.This paper applies trauma theory to Tears of the Desert, an autobiography written by the Sudanese author Halima Bashir. It examines the traumatic experience of the protagonist Halima Bashir who has been raped during Darfur conflict. In applying the aforementioned theory, this paper shows how the traumatic memory of Halima stands as a collective memory for the oppressed Sudanese in Darfur. Halima’s work, although focusing on the rape experience of an individual, implies a political message that many Sudanese were subjected to physical and psychological traumas as they were bearing witness to the conflict in Darfur

    The solution structure of the human IgG2 subclass is distinct from those for human IgG1 and IgG4 providing an explanation for their discrete functions

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    Human IgG2 antibody displays distinct therapeutically-useful properties compared with the IgG1, IgG3 and IgG4 antibody subclasses. IgG2 is the second most abundant IgG subclass, being able to bind human FcγRII/FcγRIII, but not to FcγRI or complement C1q. Structural information on IgG2 is limited by the absence of a full-length crystal structure for this. To this end, we determined the solution structure of human myeloma IgG2 by atomistic X-ray and neutron scattering modelling. Analytical ultracentrifugation disclosed that IgG2 is monomeric with a sedimentation coefficient s020,w of 7.2 S. IgG2 dimer formation was ≤ 5% and independent of the buffer conditions. Small-angle X-ray scattering in a range of NaCl concentrations and in light and heavy water revealed that the X-ray radius of gyration Rg is 5.2-5.4 nm, after allowing for radiation damage at higher concentrations, and that the neutron Rg value of 5.0 nm remained unchanged in all conditions. The X-ray and neutron distance distribution curves P(r) revealed two peaks, M1 and M2, that were unchanged in different buffers. The creation of ˃123,000 physically-realistic atomistic models by Monte Carlo simulations for joint X-ray and neutron-scattering curve fits, constrained by the requirement of correct disulfide bridges in the hinge, resulted in the determination of symmetric Y-shaped IgG2 structures. These molecular structures were distinct from those for asymmetric IgG1 and asymmetric and symmetric IgG4, and were attributable to the four hinge disulfides. Our IgG2 structures rationalize the existence of the human IgG1, IgG2, and IgG4 subclasses, and explain the receptor binding functions of IgG2

    Effect of ethanolic extract of aloe vera gel on certain common clinical pathogens

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    Antimicrobial activity of ethanolic extract of Aloe vera were observed against Staphylococcus aureus, Staphylococcus pyogenes, Staphylococcus saprophyticus, Streptococcus pneumoniae and Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae . Aloe vera leaf gel was used for ethanolic extraction.Zones of inhibition in millimeter was used to measure the antimicrobial effect. Antimicrobial susceptibility test showed that ethanolic extract has growth inhibitory effects against the tested pathogens. Ethanolic extract of Aloe vera has growth inhibitory effects against tested pathogen seen by antimicrobial susceptibility testing

    SPATIAL DIMENSION OF SOCIAL EXCLUSION. AN IMPERIAL INVESTIGATION INTO THE RELATIONSHIP OF HOUSING AND SOCIAL EXCLUSION IN THE SLUMS OF DHAKA CITY

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    Slums are perceived to be heavily populated urban areas characterized by inadequate access to safe water, hygienic sanitation, urban roads, legitimate power supply, poor structural quality of housing and insecure residential status. From that perspective, slums are the clear manifestation of urban poverty. This article emphasize that slums are not just simple expression of poverty but there is a causal process that leads to poverty and inequality. It is not a mere static state describing the inequality rather it is an outcome of structural process causing a chain of disadvantages and deprivations of the community living in the slums. In view of this, this article commences by outlining the key elements of housing in slums and through empirical findings summarises how each of these elements relate to the processes and outcomes involved in social exclusion. Findings from questionnaire interview and in-depth discussion with slum dwellers tend to lend credence to the drawing of a spatial margin of social exclusion. It is understood that slum dwellers’ socio-economic deprivation is closely related with housing elements that further leads to their segregation in social and economic life - thus invigorating a vicious cycle. The systematic exploitation, material deprivation leads to social and economic marginalization of the poor people and results in greater vulnerability of this marginalized group.Social Exclusion, spatial dimension, slums, Dhaka, Housing.
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