Photochemical and Microbial Alteration of Dissolved Organic Matter in Temperate Headwater Streams Associated with Different Land Use

[1] Photochemical and microbial transformations of DOM were evaluated in headwater streams draining forested and human-modified lands (pasture, cropland, and urban development) by laboratory incubations. Changes in DOC concentrations, DOC isotopic signatures, and DOM fluorescence properties were measured to assess the amounts, sources, ages, and properties of reactive and refractory DOM under the influence of photochemistry and/or bacteria. DOC in streams draining forest-dominated watersheds was more photoreactive than in streams draining mostly human-modified watersheds, possibly due to greater contributions of terrestrial plant-derived DOC and lower amounts of prior light exposure in forested streams. Overall, the percentage of photoreactive DOC in stream waters was best predicted by the relative content of terrestrial fluorophores. The bioreactivity of DOC was similar in forested and human-modified streams, but variations were correlated with temperature and may be further controlled by the diagenetic status of organic matter. Alterations to DOC isotopes and DOM fluorescence properties during photochemical and microbial incubations were similar between forested and human-modified streams and included (1) negligible effects of microbial alteration on DOC isotopes and DOM fluorescence properties, (2) selective removal of 13C-depleted and 14C-enriched DOC under the combined influence of photochemical and microbial processes, and (3) photochemical alteration of DOM resulting in a preferential loss of terrestrial humic fluorescence components relative to microbial fluorescence components. This study provides a unique comparison of DOC reactivity in a regional group of streams draining forested and human-modified watersheds and indicates the importance of land use on the photoreactivity of DOC exported from upstream watersheds.

Climate, Land Use and Hydrologic Sensitivities of Stormwater Quantity and Quality in Complex Coastal Urban Watersheds

The study analyzed hydro-climatic and land use sensitivities of stormwater runoff and quality in the complex coastal urban watershed of Miami River Basin, Florida by developing a Storm Water Management Model (EPA SWMM 5). Regression-based empirical models were also developed to explain stream water quality in relation to internal (land uses and hydrology) and external (upstream contribution, seawater) sources and drivers in six highly urbanized canal basins of Southeast Florida. Stormwater runoff and quality were most sensitive to rainfall, imperviousness, and conversion of open lands/parks to residential, commercial and industrial areas. In-stream dissolved oxygen and total phosphorus in the watersheds were dictated by internal stressors while external stressors were dominant for total nitrogen and specific conductance. The research findings and tools will be useful for proactive monitoring and management of storm runoff and urban stream water quality under the changing climate and environment in South Florida and around the world.

Customization of the design of antenna using genetic algorithm and finite-difference time-domain technique

Antenna design is an iterative process in which structures are analyzed and changed to comply with certain performance parameters required. The classic approach starts with analyzing a "known" structure, obtaining the value of its performance parameter and changing this structure until the "target" value is achieved. This process relies on having an initial structure, which follows some known or "intuitive" patterns already familiar to the designer. The purpose of this research was to develop a method of designing UWB antennas. What is new in this proposal is that the design process is reversed: the designer will start with the target performance parameter and obtain a structure as the result of the design process. This method provided a new way to replicate and optimize existing performance parameters. The base of the method was the use of a Genetic Algorithm (GA) adapted to the format of the chromosome that will be evaluated by the Electromagnetic (EM) solver. For the electromagnetic study we used XFDTD™ program, based in the Finite-Difference Time-Domain technique. The programming portion of the method was created under the MatLab environment, which serves as the interface for converting chromosomes, file formats and transferring of data between the XFDTD™ and GA. A high level of customization had to be written into the code to work with the specific files generated by the XFDTD™ program. Two types of cost functions were evaluated; the first one seeking broadband performance within the UWB band, and the second one searching for curve replication of a reference geometry. The performance of the method was evaluated considering the speed provided by the computer resources used. Balance between accuracy, data file size and speed of execution was achieved by defining parameters in the GA code as well as changing the internal parameters of the XFDTD™ projects. The results showed that the GA produced geometries that were analyzed by the XFDTD™ program and changed following the search criteria until reaching the target value of the cost function. Results also showed how the parameters can change the search criteria and influence the running of the code to provide a variety of geometries.

Aerodynamic load characteristics evaluation and tri-axial performance testing on fiber reinforced polymer connections and metal fasteners to promote hurricane damage mitigation

Damages during extreme wind events highlight the weaknesses of mechanical fasteners at the roof-to-wall connections in residential timber frame buildings. The allowable capacity of the metal fasteners is based on results of unidirectional component testing that do not simulate realistic tri-axial aerodynamic loading effects. The first objective of this research was to simulate hurricane effects and study hurricane-structure interaction at full-scale, facilitating better understanding of the combined impacts of wind, rain, and debris on inter-component connections at spatial and temporal scales. The second objective was to evaluate the performance of a non-intrusive roof-to-wall connection system using fiber reinforced polymer (FRP) materials and compare its load capacity to the capacity of an existing metal fastener under simulated aerodynamic loads. ^ The Wall of Wind (WoW) testing performed using FRP connections on a one-story gable-roof timber structure instrumented with a variety of sensors, was used to create a database on aerodynamic and aero-hydrodynamic loading on roof-to-wall connections tested under several parameters: angles of attack, wind-turbulence content, internal pressure conditions, with and without effects of rain. Based on the aerodynamic loading results obtained from WoW tests, sets of three force components (tri-axial mean loads) were combined into a series of resultant mean forces, which were used to test the FRP and metal connections in the structures laboratory up to failure. A new component testing system and test protocol were developed for testing fasteners under simulated triaxial loading as opposed to uni-axial loading. The tri-axial and uni-axial test results were compared for hurricane clips. Also, comparison was made between tri-axial load capacity of FRP and metal connections. ^ The research findings demonstrate that the FRP connection is a viable option for use in timber roof-to-wall connection system. Findings also confirm that current testing methods of mechanical fasteners tend to overestimate the actual load capacities of a connector. Additionally, the research also contributes to the development a new testing protocol for fasteners using tri-axial simultaneous loads based on the aerodynamic database obtained from the WoW testing. ^

Adaptation of trailing spouses: Does gender matter?

The adaptation to a new country is a complex and stressful process that is compounded when changes in status and identity have to be made. This exploratory study examined the adaptation of international company transferee spouses when they decide to follow the transferee on overseas assignments. Research to date indicates that the spouses’ dissatisfaction with life abroad is the leading cause of transferees breaking contract and prematurely returning home. The causes of this dissatisfaction are still not clear and this study sought greater clarification, particularly examining the experiences of male as well as female trailing spouses. The study, thus, takes gender as a main variable to consider. It explores how gendered expectations inherent in the structures of society inflect and inform the decisions, attitudes, and behaviors that affect the adaptations of trailing spouses living in a foreign habitus. The study is based on eight months of ethnographic research in two culturally different locations, Kuala Lumpur, Malaysia and Brussels, Belgium. Forty-two American international company transferee spouses were recruited (seven males and thirty-five females). The data analysis revolved around five main themes: (1) the comparison of male with female trailing spouses’ experiences, (2) the effect of location on spouses’ adaptation, (3) the communities that spouses integrate into, (4) variations in personal work and family histories, and (5) conditions of exit. The analysis engaged multiple theories regarding gender, sociological adaptation, and psychological adaptation. Results indicate that both socio-cultural and psychological factors affect adaptation and that gender matters very significantly, particularly along two axes: (1) gendered structures in our society create different reasons why males and females become trailing spouses, (2) the gendered social constructions of role expectations make the experience of being a trailing husband different from being a trailing wife. In addition spouses’ status as parents (or not) and their “readiness for change” were found to be important predictors of positive spousal adaptation. In contrast, significant ties with families in the home country and strong professional identity with career projections were important predictors of negative spousal adaptation.

Inspection of parts with complex geometry and welds with structural health monitoring techniques

Structural Health Monitoring (SHM) systems were developed to evaluate the integrity of a system during operation, and to quickly identify the maintenance problems. They will be used in future aerospace vehicles to improve safety, reduce cost and minimize the maintenance time of a system. Many SHM systems were already developed to evaluate the integrity of plates and used in marine structures. Their implementation in manufacturing processes is still expected. The application of SHM methods for complex geometries and welds are two important challenges in this area of research. This research work started by studying the characteristics of piezoelectric actuators, and a small energy harvester was designed. The output voltages at different frequencies of vibration were acquired to determine the nonlinear characteristics of the piezoelectric stripe actuators. The frequency response was evaluated experimentally. AA battery size energy harvesting devices were developed by using these actuators. When the round and square cross section devices were excited at 50 Hz frequency, they generated 16 V and 25 V respectively. The Surface Response to Excitation (SuRE) and Lamb wave methods were used to estimate the condition of parts with complex geometries. Cutting tools and welded plates were considered. Both approaches used piezoelectric elements that were attached to the surfaces of considered parts. The variation of the magnitude of the frequency response was evaluated when the SuRE method was used. The sum of the square of the differences was calculated. The envelope of the received signal was used for the analysis of wave propagation. Bi-orthogonal wavelet (Binlet) analysis was also used for the evaluation of the data obtained during Lamb wave technique. Both the Lamb wave and SuRE approaches along with the three methods for data analysis worked effectively to detect increasing tool wear. Similarly, they detected defects on the plate, on the weld, and on a separate plate without any sensor as long as it was welded to the test plate.

Okay Cool No Smoking Love Pony

This poetry collection moves from the narrator’s childhood in the marshes of Canada to her coming of age in a new, southern swamp in South Florida. Many of the poems use free verse as well as fairly recent poetic forms like the Golden Shovel and the Pecha Kucha. Others rely on wordplay and nonce forms. Influenced by Hector Veil Temperly, Matthew Zapruder, Dorothea Lasky, Laura Kasischke and Anne Carson, the poems often employ simple language in stream of consciousness, and oscillate between lyric and narrative. These poems are feverish creations inspired by the oracular tradition and induced by the psychic crush of modern life: depression of the body and mind, cultural paranoia, and the decline of nature. The reader is privy not only to the personal biography of the narrator, but also to the inner workings of the narrator’s mind as it encounters and interprets the world.

Aerodynamic Load Characteristics Evaluation and Tri-Axial Performance Testing on Fiber Reinforced Polymer Connections and Metal Fasteners to Promote Hurricane Damage Mitigation

Damages during extreme wind events highlight the weaknesses of mechanical fasteners at the roof-to-wall connections in residential timber frame buildings. The allowable capacity of the metal fasteners is based on results of unidirectional component testing that do not simulate realistic tri-axial aerodynamic loading effects. The first objective of this research was to simulate hurricane effects and study hurricane-structure interaction at full-scale, facilitating better understanding of the combined impacts of wind, rain, and debris on inter-component connections at spatial and temporal scales. The second objective was to evaluate the performance of a non-intrusive roof-to-wall connection system using fiber reinforced polymer (FRP) materials and compare its load capacity to the capacity of an existing metal fastener under simulated aerodynamic loads. The Wall of Wind (WoW) testing performed using FRP connections on a one-story gable-roof timber structure instrumented with a variety of sensors, was used to create a database on aerodynamic and aero-hydrodynamic loading on roof-to-wall connections tested under several parameters: angles of attack, wind-turbulence content, internal pressure conditions, with and without effects of rain. Based on the aerodynamic loading results obtained from WoW tests, sets of three force components (tri-axial mean loads) were combined into a series of resultant mean forces, which were used to test the FRP and metal connections in the structures laboratory up to failure. A new component testing system and test protocol were developed for testing fasteners under simulated tri-axial loading as opposed to uni-axial loading. The tri-axial and uni-axial test results were compared for hurricane clips. Also, comparison was made between tri-axial load capacity of FRP and metal connections. The research findings demonstrate that the FRP connection is a viable option for use in timber roof-to-wall connection system. Findings also confirm that current testing methods of mechanical fasteners tend to overestimate the actual load capacities of a connector. Additionally, the research also contributes to the development a new testing protocol for fasteners using tri-axial simultaneous loads based on the aerodynamic database obtained from the WoW testing.

Adaptation of Trailing Spouses: Does Gender Matter?

The adaptation to a new country is a complex and stressful process that is compounded when changes in status and identity have to be made. This exploratory study examined the adaptation of international company transferee spouses when they decide to follow the transferee on overseas assignments. Research to date indicates that the spouses’ dissatisfaction with life abroad is the leading cause of transferees breaking contract and prematurely returning home. The causes of this dissatisfaction are still not clear and this study sought greater clarification, particularly examining the experiences of male as well as female trailing spouses. The study, thus, takes gender as a main variable to consider. It explores how gendered expectations inherent in the structures of society inflect and inform the decisions, attitudes, and behaviors that affect the adaptations of trailing spouses living in a foreign habitus. The study is based on eight months of ethnographic research in two culturally different locations, Kuala Lumpur, Malaysia and Brussels, Belgium. Forty-two American international company transferee spouses were recruited (seven males and thirty-five females). The data analysis revolved around five main themes: (1) the comparison of male with female trailing spouses’ experiences, (2) the effect of location on spouses’ adaptation, (3) the communities that spouses integrate into, (4) variations in personal work and family histories, and (5) conditions of exit. The analysis engaged multiple theories regarding gender, sociological adaptation, and psychological adaptation. Results indicate that both socio-cultural and psychological factors affect adaptation and that gender matters very significantly, particularly along two axes: (1) gendered structures in our society create different reasons why males and females become trailing spouses, (2) the gendered social constructions of role expectations make the experience of being a trailing husband different from being a trailing wife. In addition spouses’ status as parents (or not) and their “readiness for change” were found to be important predictors of positive spousal adaptation. In contrast, significant ties with families in the home country and strong professional identity with career projections were important predictors of negative spousal adaptation.