Some concern has been expressed that the load capacity of corner columns might be reduced in fire due to the expansion of unprotected fire-exposed connected beams, even through the columns themselves are protected from fire. A structural analysis program VULCAN has been used to perform a series of parametric studies on corner sub-frames. In order to obtain the best possible representation of the column cross- section, the formulation of beam-column elements was developed to allow the cross- section to be divided into large numbers of segments. The analyses indicate that the existing fire design codes, such as BS5950: Part 8, give an un-conservative result. The finite element method is shown to be capable of modelling this type of sub- frame, but is too complex to be used routinely. As an alternative, a generalised simplified approach to enable a rapid assessment of the sub-frame by hand or spreadsheet calculation has been developed. The results, in comparison with the finite element analyses, give some confidence in the use of this approach. The beam-column elements of the program VULCAN were further developed to model the three-dimensional behaviour of asymmetric steel beams for fire conditions. The general approach, including the principles and details of the modifications to the formulation for asymmetric cross-sections, together with the refinement of the cross- section, are presented. The modified program has been validated by comparison with classical analytical results and test results at ambient and high temperatures. A new generalised beam model has been developed, which can model not only reinforced concrete sections but also steel sections of different shapes including hollow sections, for three-dimensional composite structures at ambient and high temperatures. The method currently includes both geometrical and material non linearities and considers the cracking and crushing of concrete. Several material models have been included, especially for concrete in tension which shows significant effects on the results. The thermal expansion and degradation of both steel and concrete materials with elevated temperatures are also included. The cross- section is divided into an appropriate number of segments so that non-uniform temperature profiles, and variations of strain and stress across the section, can be represented with more accuracy. The formulation is used to further develop the program VULCAN, and is then validated by comparison with theoretical and experimental results.

No description available.

Master of Science / Department of Architectural Engineering and Construction Science / Kimberly Waggle Kramer / Architecturally exposed structural steel, AESS, is a unique member designation used in contract documents to describe steel members designed according to stringent provisions as to be completely exposed in close proximity to the human eye after the structure is completed, rather than concealed from view. These members are often used to convey architectural art or expression, and have a distinctive beauty that attracts the eye. The requirements for AESS members are much more stringent than those for typical structural steel members, and therefore is more controversial as to whether it is worth the extra attention it requires. The purpose of this report is to examine the design, detailing, fabrication and execution of architecturally exposed structural steel. This is done by examining what contributes to each of these stages from design to field erection. Much of this report is based on guides and sample specification by various sources, including the Structural Engineers Association of Colorado (SEAC), Rocky Mountain Steel Construction Association (RMSCA), and the AISC 303-10 Code of Standard Practice for Steel Buildings and Bridges (American Institute of Steel Construction Committee on the Code of Standard Practice, 2010) in addition to other sources. The conglomeration and in-depth review of this information provides the Structural Engineer, Architect, Fabricator and Owner an enhanced understanding and knowledge of AESS, as to make better decisions throughout its use.

We propose a novel medium access control scheme which borrows ideas from the dual busy tone approach and the IEEE 802.11e standard for improving quality of services in wireless networks. In the field of medium access control in Wireless LAN, there are two notorious problems, which have been studied for a long time. They are the hidden terminal problem and the exposed terminal problem. To avoid the collisions caused by hidden terminals, the RTS/CTS approach is widely adopted. However, RTS and CTS frames themselves are still subject to collisions. The Transmit Busy Tone and the Receive Busy Tone were proposed to further mitigate the hidden terminal problem and the exposed terminal problem. The transmit busy tone provides protection for the RTS packets and thus, increase the probability of successful RTS reception at the intended receiver. The receive busy tone acknowledges the RTS packet and provide continuous protection for the subsequent data packets. We use computer simulations to justify the usage of our proposal. We show that the proposed scheme outperforms the IEEE 802.11e standard.

With the increasing miniaturization of transistors, wire delays are becoming a dominant factor in microprocessor performance. To address this issue, a number of emerging architectures contain replicated processing units with software-exposed communication between one unit and another (e.g., Raw, SmartMemories, TRIPS). However, for their use to be widespread, it will be necesary to develop a common machine language to allow programmers to express an algorithm in a way that can be efficiently mapped across these architectures. We propose a new common machine language for grid-based software-exposed architectures: StreamIt. StreamIt is a high-level programming language with explicit support for streaming computation. Unlike sequential programs with obscured dependence information and complex communication patterns, a stream program is naturally written as a set of concurrent filters with regular steady-state communication. The language imposes a hierarchical structure on the stream graph that enables novel representations and optimizations within the StreamIt compiler. We have implemented a fully functional compiler that parallelizes StreamIt applications for Raw, including several load-balancing transformations. Though StreamIt exposes the parallelism and communication patterns of stream programs, analysis is needed to adapt a stream program to a software-exposed processor. We describe a partitioning algorithm that employs fission and fusion transformations to adjust the granularity of a stream graph, a layout algorithm that maps a stream graph to a given network topology, and a scheduling strategy that generates a fine-grained static communication pattern for each computational element. Using the cycle-accurate Raw simulator, we demonstrate that the StreamIt compiler can automatically map a high-level stream abstraction to Raw. We consider this work to be a first step towards a portable programming model for communication-exposed architectures. / Singapore-MIT Alliance (SMA)

Previous research into the subsequent effects of prenatal methadone exposure has primarily focused on neurological changes and short term physical development. While there have been some studies of behavioural development, only short term effects have been investigated. The present research therefore aimed to assess longer term behavioural development of offspring exposed to methadone gestationally, lactationally or both. Methadone was provided in the drinking water of drug-treated rat dams during gestation (2.39mg/kg/day) and lactation (2.86mg/kg/day). The four conditions were: non-exposure/control (N = 24), gestational-exposure (N = 20), lactational-exposure (N = 24), and combined-exposure (N = 21). As well as several measures of pregnancy characteristics, offspring postnatal physical development was assessed at 30, 60 and 120 days after birth. Behavioural assessments were also made at these ages by means of an open-field, Y maze and emergence apparatus. There were no significant differences in physical development. Maternal methadone exposure during gestation reduced the number of rat dams that became (or remained) pregnant. In the offspring, there was increased activity in lactationally-exposed rats through into adulthood. Anxiety was increased in the combined-exposure condition, primarily in adolescent males. The significant longer term effects of earlier methadone on the rats’ behavioural development supported the need for more research into this hitherto relatively neglected area. More information about effects of methadone exposure on anxiety and activity, as well as on social functioning and motor coordination could be useful for understanding potential risk factors in the ever growing methadone-exposed population, and thus suggesting best practice for methadone maintenance programmes.

No description available.

Individuals may develop symptoms in response to inhaled odors, chemicals, and irritants. This may affect their quality of life. Little is known about the prevalence and severity of symptoms that result from exposure to odors, chemicals and irritants. This study demonstrates the development of a new respiratory questionnaire to detect the prevalence and severity of symptoms experienced upon exposure to chemicals, odors, and irritants, and relates these symptoms to quality of life. This questionnaire was submitted to 96 volunteers at the University of South Florida College of Public Health who responded to items regarding symptoms developed in response to exposure to automobile exhaust, cigarette smoke, strong smells, cologne, perfumes or scented candles, or fresh paint vapors or fumes. Health-related quality of life was assessed using a subscale included with the questionnaire. The number and severity of symptoms developed in response to exposure to odors, chemicals, and irritants showed a strong negative correlation with health-related quality of life, consistent with intuitive estimates of the direction of this relationship. Also, it was shown that in normal populations, males and females develop statistically similar prevalence and severity of symptoms in response to exposure to odors, chemicals, and irritants.

Geosynthetic Clay Liners (GCLs) are commonly paired with a geomembrane and used as part of a composite liner system for landfill barriers. Under some circumstances, leaving a composite geomembrane/geosynthetic clay liner exposed to solar radiation in the field has been shown to cause shrinkage of the underlying GCL. Recent field studies have shown that leaving a composite liner exposed can also lead to down-slope erosion of bentonite from the GCL due to the down-slope movement of moisture. To investigate the factors that can affect the onset of bentonite erosion in a GCL an experimental technique was developed to reproduce similar erosion in the laboratory. The test method simulates the features that occur with the erosion of bentonite caused by down-slope migration of evaporative water in the field. One needle-punched GCL was tested to examine the factors that can affect the onset of erosion of bentonite particles with the flow of water. The factors examined include the effect of the initial wet/dry cycle, water source chemistry, flow rate, slope, prior cation exchange, and the effect of no drying phase in the test cycle. Ten different manufactured GCL products were tested to examine the effect of material properties on the erosion of bentonite from a GCL. The material properties of the products tested differed in terms of the type of carrier and cover geotextiles, bentonite (powdered, fine and coarse grained, and some with a polymer enhancement additive) and the presence of a polypropylene coating over the geotextile. It was found that the most critical factor to trigger the onset of bentonite erosion was the water source chemistry, with the tests that simulated the evaporation and condensation of water (deionized water) below an exposed composite liner leading to the formation of major erosion features. The results of the laboratory testing program also show that erosion features are more visible in products with white coloured geotextiles. The products containing a polypropylene coated geotextile and polymer enhanced bentonite slowed or, in some cases, prevented erosion features from developing. / Thesis (Master, Civil Engineering) -- Queen's University, 2014-05-01 10:16:14.05

Violence-exposed children are unintended victims, often an unseen and overlooked victim group in society. It is a societal responsibility that all victims are realized and supported. Through describing the perspective of professionals meeting these children, their status and opportunities in society and legal system can be investigated. To study professionals’ experiences, conceptions, and knowledge about violence-exposed children, a questionnaire was distributed to 63 professionals, representing police, prosecutors, social- and treatment personnel. Qualitative questions about experiences and knowledge were analysed thematically. Additional quantitative statements of held conceptions were analysed with t-tests and regression methods. Findings revealed these children are still overlooked; psychological knowledge about their symptoms, testimonies, and perspective is lacking; professional routines/guidelines are missing; and problems such as children’s legal status as non-victims are hindering effective work to guarantee these children’s care. Results provide information facilitating necessary changes to ensure this group of psychologically abused victims’ recovery and societal rights.