Alternatives to steel grid bridge decks

Most of the moveable bridges use open grid steel decks, because these are factory assembled, light-weight, and easy to install. Open grid steel decks, however, are not as skid resistant as solid decks. Costly maintenance, high noise levels, poor riding comfort and susceptibility to vibrations are among the other disadvantages of these decks. The major objective of this research was to develop alternative deck systems which weigh no more than 25 lb/ft2, have solid riding surface, are no more than 4–5 in. thick and are able to withstand prescribed loading. Three deck systems were considered in this study: ultra-high performance concrete (UHPC) deck, aluminum deck and UHPC-fiber reinforced polymer (FRP) tube deck. UHPC deck was the first alternative system developed as a part of this project. Due to its ultra high strength, this type of concrete results in thinner sections, which helps satisfy the strict self-weight limit. A comprehensive experimental and analytical evaluation of the system was carried out to establish its suitability. Both single and multi-unit specimens with one or two spans were tested for static and dynamic loading. Finite element models were developed to predict the deck behavior. The study led to the conclusion that the UHPC bridge deck is a feasible alternative to open grid steel deck. Aluminum deck was the second alternative system studied in this project. A detailed experimental and analytical evaluation of the system was carried out. The experimental work included static and dynamic loading on the deck panels and connections. Analytical work included detailed finite element modeling. Based on the in-depth experimental and analytical evaluations, it was concluded that aluminum deck was a suitable alternative to open grid steel decks and is ready for implementation. UHPC-FRP tube deck was the third system developed in this research. Prestressed hollow core decks are commonly used, but the proposed type of steel-free deck is quite novel. Preliminary experimental evaluations of two simple-span specimens, one with uniform section and the other with tapered section were carried out. The system was shown to have good promise to replace the conventional open grid decks. Additional work, however, is needed before the system is recommended for field application.

A qualitative case study of teacher perceptions and concerns during the implementation of literacy folders in a select elementary school in Broward County, Florida

Classroom teachers are often required to implement new procedures or practices in response to local or federal education mandates. Attempts to implement innovations, often do not take into account the personal side of change; the perceptions, concerns and needs of those required to implement the innovation. One innovation that was required by the School Board of Broward County, Florida for all elementary classroom teachers was the implementation of Literacy Folders. ^ This study attempted to address the personal side of change by identifying teacher concerns during the implementation of Literacy Folders in a select elementary school in Broward County Florida. The Concerns Based Adoption model (CBAM) for change was used as the conceptual framework for this qualitative case study. ^ Sources of data for this study included participant interviews, observations and analysis of documents. Informal conversations with the participants and unscheduled classroom visits were also sources of data. Seven classroom teachers were interviewed using a predesigned interview guide developed based on the CBAM of change, specifically the Stages of Concern Dimension. Participant responses were coded into two categories, (a) recollections of past perceptions, and (b) present perceptions regarding the innovation. ^ Data analysis resulted in the emergence of one major theme and two subordinate themes. The themes were related to time and purpose of the innovation. The researcher also discovered that the participants exhibited responses typically representative of the CBAM for individuals who are in the process of adjusting to a new innovation. ^ Recommendations based on participant concerns are made for improving the implementation of the innovation. Recommendations for alternatives to the innovation and suggestions regarding areas for further research in the field of educational change are also made. ^

Syntheses of aza analogs of kainoids

The kainoids are a class of non-proteinogenic pyrrolidine dicarboxylates that exhibit both excitatory and excitotoxic activities. These activities are a result of the ability of the kainoids to act as glutamate receptor agonists by activating ionotropic glutamate receptors. The parent of this group of compounds is α-kainic acid. Kainic acid is isolated from the seaweed Diginea simplex and has been used in Asian countries as a treatment for intestinal worms in children. In addition it is used extensively by neuropharmacologists for the study of glutamate receptors. Several years ago, the world's sole supplier of kainic acid discontinued this product. Since that time, other sources have appeared, however, the price of kainic acid remains significantly higher than it once was. We have thus been working on synthesizing aza analogs of kainoids which would be less costly but potentially potent alternatives to kainic acid via the dipolar cycloadditions of diazoalkanes with trans diethyl glutaconate. These 1, 3-dipolar cycloadditions yielded 2-pyrazolines or pyrazoles. The 2-pyrazolines may be precursors to aza analogs of kainoids. The regioselectivity of these 1, 3-dipolar cycloadditions and isomerization of the 1-pyrazolines to 2-pyrazolines was evaluated. Reductions of the 2-pyrazolines yielded aza analogs of kainoids.^ TMS diazomethane, due to the commercial availability, has been frequently used as a synthetic reagent in 1, 3-dipolar cycloadditions, particularly in the preparation of novel amino acid analogs. A survey of the recent literature indicates that the regioselectivity of the double bond isomerization of TMS substituted 1-pyrazolines is variable and at first glance, unpredictable. In an effort to develop a mechanistic rational for the isomerization which could account for the products obtained, a systematic survey of dipolar cycloadditions between TMS diazomethane and α, β-unsaturated dipolarophiles was undertaken. It was suggested that the steric demand of the dipolarophiles had a profound effect on both the relative stereochemistry of dipolar cycloaddition reactions of TMSCHN2 and the preferred direction of isomerization of the resulting 1-pyrazoline.^

Development of a medium-capacity guideway transit planning guide

Rapid population increase and booming economic growth have caused a significant escalation in car ownership in many cities, leading to additional or, multiple traffic problems on congested roadways. The increase of automobiles is generating a significant amount of congestion and pollution in many cities. It has become necessary to find a solution to the ever worsening traffic problems in our cities. Building more roadways is nearly impossible due to the limitations of right-of-way in cities. Studies have shown that guideway transit could provide effective transportation and could stimulate land development. The Medium-Capacity Guideway Transit (MCGT) is one of the alternatives to solve this problem. The objective of this research was to better understand the characteristics of MCGT systems, to investigate the existing MCGT systems around the world and determine the main factors behind the planning of successful systems, and to develop a MCGT planning guide. The factors utilized in this study were determined and were analyzed using Excel. A MCGT Planning Guide was developed using Microsoft Visual Basic. ^ A MCGT was defined as a transit system whose capacity can carry up to 20,000 passengers per hour per direction (pphpd). The results shown that Light Rail Transit (LRT) is favored when peak hour demand is less than 13,000 pphpd. Automated People Mover (APM) is favored when the peak hour demand is more than 18,000 pphpd. APM systems could save up to three times the waiting time cost compared to that of the LRT. If comfort and convenience are important, then using an APM does make sense. However, if cost is the critical factor, then LRT will make more sense because it is reasonable service at a reasonable price. If travel time and safety (accident/crush) costs were included in calculating life-cycle “total” costs, the capital cost advantage of LRT disappeared and APM could become very competitive. The results also included a range of cost-performance criteria for MCGT systems that help planners, engineers, and decision-makers to select the most feasible system for their respective areas. ^

Advanced oxidation of arsenic species in aqueous solutions

Ingestion of arsenic from contaminated water is a serious problem and affects the health of more than 100 million people worldwide. Traditional water purification technologies are generally not effective or cost prohibitive for the removal of arsenic to acceptable levels (≤10 ppb). Current multi-step arsenic removal processes involve oxidation, precipitation and/or adsorption. Advanced Oxidation Technologies (AOTs) may be attractive alternatives to existing treatments. The reactions of inorganic and organic arsenic species with reactive oxygen species were studied to develop a fundamental mechanistic understanding of these reactions, which is critical in identifying an effective and economical technology for treatment of arsenic contaminated water. ^ Detailed studies on the conversion of arsenite in aqueous media by ultrasonic irradiation and TiO2 photocatalytic oxidation (PCO) were conducted, focusing on the roles of hydroxyl radical and superoxide anion radical formed during the irradiation. ·OH plays the key role, while O2 -· has little or no role in the conversion of arsenite during ultrasonic irradiation. The reaction of O2-· does not contribute in the rapid conversion of As(III) when compared to the reaction of As(III) with ·OH radical during TiO2 PCO. Monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) are readily degraded upon TiO2 PCO. DMA is oxidized to MMA as the intermediate and arsenate as the final product. For dilute solutions, TiO2 also may be applicable as an adsorbent for direct removal of arsenic species, namely As(III), As(V), MMA and DMA, all of which are strongly adsorbed, thus eliminating the need for a multi-step treatment process. ^ Phenylarsonic acid (PA) was subjected to gamma radiolysis under hydroxyl radical generating conditions, which showed rapid degradation of PA. Product analysis and computational calculation both indicate the arsenate group is an ortho, para director. Our results indicate · OH radical mediated processes should be effective for the remediation of phenyl substituted arsonic acids. ^ While hydroxyl radical generating methods, specifically AOTs, appear to be promising methods for the treatment of a variety of arsenic compounds in aqueous media, pilot studies and careful economic analyses will be required to establish the feasibility of AOTs applications in the removal of arsenic. ^

Rich and poor, white and black, free and slave: The social history of Cuba's tobacco farmers, 1763--1817

Tobacco was of primary importance to Spain, and its impact on Cuba's economy and society was greater than just the numbers of farms, workers, or production, demonstrated by the Spanish crown's outlay of monies for capital assets, bureaucrats' salaries, and payments to farmers for their crop. This study is a micro- and macro-level study of rural life in colonial Cuba and the interconnected relationships among society, agricultural production, state control, and the island's economic development. ^ By placing Cuba's tobacco farmers at the forefront of this social history, this work revisits and offers alternatives to two prevailing historiographical views of rural Cuba from 1763 (the year Havana returned to Spanish control following the Seven Years' War) to 1817 (the final year of the 100-year royal monopoly on Cuban tobacco). Firstly, it argues against the primacy of sugar over other agricultural crops, a view that has shaped decades of scholarship, and challenges the thesis which maintains the Cuban tobacco farmer was almost exclusively poor, white, and employed free labor, rather than slaves, in the production of their crop. ^ This study establishes the importance of tobacco as an agricultural product, and argues that Cuban tobacco growers were a heterogeneous group, revealing the role that its cultivation may have played in helping some slaves earn their freedom. ^

Mechanistic studies on the advanced oxidation and photochemical transformation of cyanotoxins (microcystins)

The increased occurrence of cyanobacteria (blue-green algae) blooms and the production of associated cyanotoxins have presented a threat to drinking water sources. Among the most common types of cyanotoxins found in potable water are microcystins (MCs), a family of cyclic heptapeptides containing substrates. MCs are strongly hepatotoxic and known to initiate tumor promoting activity. The presence of sub-lethal doses of MCs in drinking water is implicated as one of the key risk factors for an unusually high occurrence of primary liver cancer. ^ A variety of traditional water treatment methods have been attempted for the removal of cyanotoxins, but with limited success. Advanced Oxidation Technologies (AOTs) are attractive alternatives to traditional water treatments. We have demonstrated ultrasonic irradiation and UV/H2O2 lead to the degradation of cyanotoxins in drinking water. These studies demonstrate AOTs can effectively degrade MCs and their associated toxicity is dramatically reduced. We have conducted detailed studies of different degradation pathways of MCs and conclude that the hydroxyl radical is responsible for a significant fraction of the observed degradation. Results indicate preliminary products of the sonolysis of MCs are due to the hydroxyl radical attack on the benzene ring and substitution and cleavage of the diene of the Adda peptide residue. AOTs are attractive methods for treatment of cyanotoxins in potable water supplies. ^ The photochemical transformation of MCs is important in the environmental degradation of MCs. Previous studies implicated singlet oxygen as a primary oxidant in the photochemical transformation of MCs. Our results indicate that singlet oxygen predominantly leads to degradation of the phycocyanin, pigments of blue green algae, hence reducing the degradation of MCs. The predominant process involves isomerization of the diene (6E to 6Z) in the Adda side chain via photosensitized isomerization involving the photoexcited phycocyanin. Our results indicate that photosensitized processes play a key role in the environmental fate and elimination of MCs in the natural waters. ^

Integrated Ecological Modeling and Decision Analysis Within the Everglades Landscape

Planning for complex ecosystem restoration projects involves integrating ecological modeling with analysis of performance trade-offs among restoration alternatives. The authors used the Everglades Landscape Model and Multi-Criteria Decision Analysis to explore the effect of simulated ecosystem performance, risk preferences, and criteria weights on the ranking of three alternatives to restoring overland sheet flow in the Everglades. The ecological model outputs included both hydrologic and water quality criteria. Results were scored in the decision analysis framework, highlighting the trade-offs between hydrologic restoration and water quality constraints. Given equal weighting of performance measures, the alternative with more homogenous sheet flow was preferred over other alternatives, despite evidence of some localized eutrophication risk.

Effect of arginine and oscillatory calcium ion (II) on vascular response mediated via nitric oxide signaling in normal and salt sensitive hypertensive rat mesenteric arterioles

Hypertension, a major risk factor in the cardiovascular system, is characterized by an increase in the arterial blood pressure. High dietary sodium is linked to multiple cardiovascular disorders including hypertension. Salt sensitivity, a measure of how the blood pressure responds to salt intake is observed in more than 50% of the hypertension cases. Nitric Oxide (NO), as an endogenous vasodilator serves many important biological roles in the cardiovascular physiology including blood pressure regulation. The physiological concentrations for NO bioactivity are reported to be in 0-500 nM range. Notably, the vascular response to NO is highly regulated within a small concentration spectrum. Hence, much uncertainty surrounds how NO modulates diverse signaling mechanisms to initiate vascular relaxation and alleviate hypertension. Regulating the availability of NO in the vasculature has demonstrated vasoprotective effects. In addition, modulating the NO release by different means has proved to restore endothelial function. In this study we addressed parameters that regulated NO release in the vasculature, in physiology and pathophysiology such as salt sensitive hypertension. We showed that, in the rat mesenteric arterioles, Ca2+ induced rapid relaxation (time constants 20.8 ± 2.2 sec) followed with a much slower constriction after subsequent removal of the stimulus (time constants 104.8 ± 10.0 sec). An interesting observation was that a fourfold increase in the Ca 2+ frequency improved the efficacy of arteriolar relaxation by 61.1%. Our results suggested that, Ca2+ frequency-dependent transient release of NO from the endothelium carried encoded information; which could be translated into different steady state vascular tone. Further, Agmatine, a metabolite of L-arginine, as a ligand, was observed to relax the mesenteric arterioles. These relaxations were NO-dependent and occurred via &agr;-2 receptor activity. The observed potency of agmatine (EC50, 138.7 ± 12.1 ± μM; n=22), was 40 fold higher than L-arginine itself (EC50, 18.3 ± 1.3 mM; n = 5). This suggested us to propose alternative parallel mechanism for L-arginine mediated vascular relaxation via arginine decarboxylase activity. In addition, the biomechanics of rat mesentery is important in regulation of vascular tone. We developed 2D finite element models that described the vascular mechanics of rat mesentery. With an inverse estimation approach, we identified the elasticity parameters characterizing alterations in normotensive and hypertensive Dahl rats. Our efforts were towards guiding current studies that optimized cardiovascular intervention and assisted in the development of new therapeutic strategies. These observations may have significant implications towards alternatives to present methods for NO delivery as a therapeutic target. Our work shall prove to be beneficial in assisting the delivery of NO in the vasculature thus minimizing the cardiovascular risk in handling abnormalities, such as hypertension.

A study of the top executive conference centers in the United States and an examination of the corresponding corporate meetings market

Introduction: The United States today has become "meeting-conscious." The complexity of conducting business has led to the need for sophisticated coordination of decision-making processes on all levels of the organization. Company meetings have played an increasingly important role in the success and future of many companies. Strategies and decisions are developed at meetings that can determine future policies of crucial importance. Executive training can mean the difference in whether the company will even survive. Large and growing companies have increased their off-premise meeting budgets annually in spite of the state of the economy. however, the rising costs of travel and lodging have made management monitor these budgets more closely than ever. Thus, the need to use every dollar efficiently has compelled companies to examine newer methods of running meetings and alternatives to the usage of typical off-premise meeting facilities. The importance of off-premise meetings in the United States economy has greatly increased due to the billions of dollars spent annually. These factors make it vital to explore the effectiveness of time and monetary expenditures. Up until the mid-1960's, company meetings were held in facilities of various design and purpose, none of which were specifically designed for the small to medium corporate meeting. Upon gathering information concerning the meetings market and the corporate meeting planner, certain individuals endeavored to change the situation. This study is designed to investigate this new concept, which will hereafter be referred to as "conference center." For the purpose of this study, the following two definitions will be used. 1. Conference center - that meeting facility primarily marketing its facilities for the small to medium-sized corporate meeting. The center is operated by specialists aware of market needs in as much detail as are those people working for the company involved. On-premise sleeping rooms are not mandatory provided such facilities are within easy access. 2. Meeting planner - that person within an organization who has primary responsibility for arranging off-premise meetings and all other related items necessary for meeting effectiveness. This person may spend anywhere from 10 to 100l of his time in this capacity. The conference center has effectively satisfied the need for specialized corporate meeting facilities. This study will show the depth of the corporate meetings market and trace the growth and development of this relatively new conference center concept. Information will also be compiled on the top centers in the country. It is hoped that by presenting this research meeting planners will become more aware of the nature and location of these centers, especially for use by the small to medium-sized company. Such exposure of the centers will hopefully increase existing demand and enable the construction of new, innovative centers.

More than Metadata: Where the Rubber Meets the Road in DLS Migration

This panel presentation provided several use cases that detail the complexity of large-scale digital library system (DLS) migration from the perspective of three university libraries and a statewide academic library services consortium. Each described the methodologies developed at the beginning of their migration process, the unique challenges that arose along the way, how issues were managed, and the outcomes of their work. Florida Atlantic University, Florida International University, and the University of Central Florida are members of the state's academic library services consortium, the Florida Virtual Campus (FLVC). In 2011, the Digital Services Committee members began exploring alternatives to DigiTool, their shared FLVC hosted DLS. After completing a review of functional requirements and existing systems, the universities and FLVC began the implementation process of their chosen platforms. Migrations began in 2013 with limited sets of materials. As functionalities were enhanced to support additional categories of materials from the legacy system, migration paths were created for the remaining materials. Some of the challenges experienced with the institutional and statewide collaborative legacy collections were due to gradual changes in standards, technology, policies, and personnel. This was manifested in the quality of original digital files and metadata, as well as collection and record structures. Additionally, the complexities involved with multiple institutions collaborating and compromising throughout the migration process, as well as the move from a consortial support structure with a vendor solution to open source systems (both locally and consortially supported), presented their own sets of unique challenges. Following the presentation, the speakers discussed commonalities in their migration experience, including learning opportunities for future migrations.

Effect of Arginine and Oscillatory Ca2+ on Vascular Response Mediated Via Nitric Oxide Signaling in Normal and Salt Sensitive Hypertensive Rat Mesenteric Arterioles

Hypertension, a major risk factor in the cardiovascular system, is characterized by an increase in the arterial blood pressure. High dietary sodium is linked to multiple cardiovascular disorders including hypertension. Salt sensitivity, a measure of how the blood pressure responds to salt intake is observed in more than 50% of the hypertension cases. Nitric Oxide (NO), as an endogenous vasodilator serves many important biological roles in the cardiovascular physiology including blood pressure regulation. The physiological concentrations for NO bioactivity are reported to be in 0-500 nM range. Notably, the vascular response to NO is highly regulated within a small concentration spectrum. Hence, much uncertainty surrounds how NO modulates diverse signaling mechanisms to initiate vascular relaxation and alleviate hypertension. Regulating the availability of NO in the vasculature has demonstrated vasoprotective effects. In addition, modulating the NO release by different means has proved to restore endothelial function. In this study we addressed parameters that regulated NO release in the vasculature, in physiology and pathophysiology such as salt sensitive hypertension. We showed that, in the rat mesenteric arterioles, Ca2+ induced rapid relaxation (time constants 20.8 ± 2.2 sec) followed with a much slower constriction after subsequent removal of the stimulus (time constants 104.8 ± 10.0 sec). An interesting observation was that a fourfold increase in the Ca2+ frequency improved the efficacy of arteriolar relaxation by 61.1%. Our results suggested that, Ca2+ frequency-dependent transient release of NO from the endothelium carried encoded information; which could be translated into different steady state vascular tone. Further, Agmatine, a metabolite of L-arginine, as a ligand, was observed to relax the mesenteric arterioles. These relaxations were NO-dependent and occurred via α-2 receptor activity. The observed potency of agmatine (EC50, 138.7 ± 12.1 µM; n=22), was 40 fold higher than L-arginine itself (EC50, 18.3 ± 1.3 mM; n = 5). This suggested us to propose alternative parallel mechanism for L-arginine mediated vascular relaxation via arginine decarboxylase activity. In addition, the biomechanics of rat mesentery is important in regulation of vascular tone. We developed 2D finite element models that described the vascular mechanics of rat mesentery. With an inverse estimation approach, we identified the elasticity parameters characterizing alterations in normotensive and hypertensive Dahl rats. Our efforts were towards guiding current studies that optimized cardiovascular intervention and assisted in the development of new therapeutic strategies. These observations may have significant implications towards alternatives to present methods for NO delivery as a therapeutic target. Our work shall prove to be beneficial in assisting the delivery of NO in the vasculature thus minimizing the cardiovascular risk in handling abnormalities, such as hypertension.