67 research outputs found

    Effect of substructure stiffness on the performance of integral abutment bridges under thermal loads

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    This research investigates the effect of substructure stiffness on the performance of short and medium span length Integral Abutment Bridges (IABs) subjected to thermal load. Various parameters such as foundation soil stiffness, pile orientation, pile type, and abutment geometry on the performance of IABs, are considered. Three-dimensional (3D) Finite Element (FE) models were developed using the FE software LUSAS to capture the behavior of IABs including the variations in displacement and rotation in the transverse direction for the various components of the superstructure as well as the substructure. Field measurements from a recently constructed two-span steel girder IAB were utilized to validate the 3D FE models. Using the validated model, a parametric study was carried out to study the effect of the above parameters on the performance of IABs under thermal loading using AASHTO-LRFD temperature ranges. The study shows that among the investigated parameters, the foundation soil stiffness stands as the most important factor that affects the performance of IABs. In general, the bridge behavior is more sensitive to the foundation soil stiffness during bridge contraction. The results from the study show considerable variations in displacement and rotation in the transverse direction for the various components of the superstructure and the substructure in relatively wide IABs. This research suggests that Prestressed Concrete Piles can be a viable alternative to steel H-Piles for short span bridges. It was also noticed that the stress level due to thermal loading in the various components of the bridge can be significantly reduced by enclosing the top part of the pile in an enclosure filled with crushed stone or loose sand. Moreover, the research suggests that the pile orientation has a minimum effect on the behavior of IABs. It also suggests that a slight increase in the abutment height can significantly reduce the displacement and rotation along the piles during bridge expansion. The research also suggests that 3D models are necessary to capture the behavior of IABs especially during bridge expansion. The research provides simple equations and charts to help bridge engineers calculate the displacement and rotation along the substructure.Ph. D.Includes bibliographical referencesIncludes vitaby Suhail Albhais

    The clothes have no emperor! Reflections on the crisis of violence in Lyari Town, Pakistan

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    This report seeks to decenter the dominant discourse of criminality and gang-violence which has become wedded to Lyari Town, Karachi, Pakistan. The study builds upon the insights and analyses of scholars who have sought to interrogate the state of affairs in Karachi but also deviates in important ways from the questions scholars have usually asked of Karachi by exploring the one aspect on which much of this scholarship has, for various and understandable reasons, hitherto been silent. For the partiality of our narratives may hold the possibility that the very element that escapes the analysis is the one that makes or breaks any analysis

    The Amnesia of Genesis

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    State, society and power towards a new political economy of Pakistan

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    Five sc holars engage with S Akbar Zaidi's proposed agenda for research in the political economy of Pakistan, "Rethinking Pakistan's Political Economy" (1 Febr uar y 2014). Majed A k hter introduces the discussion, Aasim Sajjad Akhtar discusses the hegemonic "politics of common sense", Fahd Ali draws on postcolon ia l theor y to engage Zaidi's use of "political settlements", Umair Javed focuses on associational politics in Punjab and Adeem Suhail theorises "the negotiated state" based on his fieldwork in Karachi. Zaidi responds to the critiques by suggest i ng they are not ruthless enough

    State Formation

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    Literature and Life

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    Seaweed minerals: unlocking functional food potential from an Indian perspective

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    Abstract Minerals and trace elements are thought to be necessary for human nutrition, and seaweeds are well known for their accumulation capacity and the rate may vary based on the locations. Green seaweeds are recognized for their iron and magnesium content, whilst brown and red seaweeds prefer to accumulate manganese, iodine, sodium, potassium, and zinc. These properties provide significant opportunities for the functional food development industry to create new ingredients and generate employment. Additionally, certain seaweeds are considered as potential candidates for addressing the iodine deficiency through regular consumption, thus seaweeds hold great potential as functional foods. This review examines the role of minerals in seaweed farming followed by their impact on seaweed growth and nutritional value, the health benefits of mineral-enriched seaweed, and its market potential as a functional food. It also discusses about the limitations, challenges, pathways for popularization, and future opportunities for seaweed as a functional food. Author name: Please confirm if the author names are presented accurately and in the correct sequence (given name, middle name/initial, family name). Author 1 Given name: [S. Shek Mohamed] Last name [Ibrahim]. Author 2 Given name: [R. Suhail] Last name [Haq]. Author 3 Given name: [S. Dinesh] Last name [Kumar]. Also, kindly confirm the details in the metadata are correct. The author's given name modified accordingly. Graphical Abstrac
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