An evaluation of minimum flexural reinforcement in concrete girders with an emphasis on post-tensioned segmental members

Providing the minimum flexural reinforcement requirements for concrete girders specifies that additional reserve capacity is provided over the flexural cracking limit state. This ensures that collapse will not occur upon flexural cracking. The AASHTO LRFD Bridge Design Specifications (2017) for the minimum flexural reinforcement requirement are experimentally based on research from 1962 and did not include segmental girders, which were not prevalent at the time. Furthermore, there has not been research regarding the minimum flexural reinforcement for segmental girders. There is also research suggesting that scale effects have an influence that was not captured in previous experimental programs. This thesis is completed to evaluate the minimum flexural reinforcement in concrete girders as part of the National Cooperative Highway Research Program (NCHRP) 12-94 project. The details of the construction of the reinforced concrete and pretensioned girders are presented. Experimental results and commentary of the testing on two reinforced concrete and three pretensioned girders have been documented. Further study was completed with the design and analytical study of segmental girders on important parameters used in deriving the minimum flexural reinforcement requirements regarding the AASHTO LRFD Bridge Specifications (2017). The overstrength moment ratio required through the AASHTO LRFD Bridge Specifications (2017) has been clarified, which allows for an adequacy evaluation for minimally reinforced girders. Through the experiments, it is shown that the full-scale girders perform adequately, despite having the minimum or less than minimum flexural reinforcement. There is also further evidence provided for a decreasing modulus of rupture value for an increasing beam depth. The bond condition of the reinforcement is shown to be a significant factor and the overstrength moment ratio remains close to one for unbonded external segmental structures, despite substantially varying the amount of prestressing steel. Girders with bonded reinforcement achieve much higher overstrength moment ratios than girders with unbonded tendons and behave more similarly to pretensioned girders. Additionally, bonded reinforcement experiences local debonding which allows for greater ductility in the structures

Cyclic Orbit Codes

In network coding a constant dimension code consists of a set of k-dimensional subspaces of F_q^n. Orbit codes are constant dimension codes which are defined as orbits of a subgroup of the general linear group, acting on the set of all subspaces of F_q^n. If the acting group is cyclic, the corresponding orbit codes are called cyclic orbit codes. In this paper we give a classification of cyclic orbit codes and propose a decoding procedure for a particular subclass of cyclic orbit codes.Comment: submitted to IEEE Transactions on Information Theor

The Immersive Media Library @ VCU

Answering the call issued by John Underkoffler in 2010 about the future of UI, I have imagined the Immersive Media Library (IML) as an annex of the main VCU library, offering a concentration of visually immersive spaces to compliment the space the university is already building in the renovated Cabell Library. The design is new in that the emphasis is placed on the collaboration between librarians and visitors in creating new work. Focusing on the interpersonal might be unexpected from program with such an emphasis on new technology - but I see it as vital part of the new computing paradigm

The Freedom to Speak: A Sociolegal and Historical Analysis of Information Gatekeeping and Speech Censorship for the Digital Era

This dissertation offers a philosophical and historical exploration of speech and content moderation to an interdisciplinary readership of students, scholars, corporate executives, policymakers, and thought leaders. Through critical textual analysis, it analyzes the sociolegal and historical objectives of protecting freedoms of expression, speech, and press. It challenges deep-seated legal premises, including the American “marketplace of ideas” and contextualizes the U.S. speech tradition within a global sociolegal framework. This inquiry is pressing. Scholarship has not thoroughly examined the implications of what I label American “speech imperialization” or “über-right fetishization:” an exceptionalist, typically latent, tendency to export neoliberal free-speech ideology internationally. Without this understanding of First Amendment deification, Americans, especially Silicon-Valley based communications companies, will be poorly positioned to handle international speech-related disputes when their speech-regulatory frameworks clash with international jurisprudence and philosophy

The Invisible Brain Injury Crisis

According to the Center for Disease Control and Prevention’s 2013 data, over 282,000 hospitalizations and 2.5 million emergency department visits were at least in part attributable to TBI. In the same year, about 56,000 people died. Emergency departments in 2012 treated about 329,290 kids under 20 for TBI following an injury taking place during physical activity. This project explores the rise in traumatic brain injuries and examines the difficult path that some of the survivors have to go through during recovery. By telling the story through my own personal experiences, I guide the reader through what the initial trauma and ensuing postconcussion syndrome can be like. The project also examines how media and changes in attitude about brain injuries could help people take them more seriously and help move along the science. Some organizations stand to lose profits though from changing attitudes on concussions, even though some of their athletes will have brain injuries for life. Even a single brain injury can change someone forever, and my project aims to educate people about brain injuries so that they knew what to do instead of feeling lost.https://medium.com/@michael.rosenthal/traumatic-brain-injuries-are-traumatic-2b1df1738a8