A Novel Method for Confirming the Presence of Volatile Reduced Sulfide Compounds via Inductively Coupled Plasma-Optical Emission Spectroscopy

Millions of dollars in destruction in the past decade have resulted from the use of Chinese drywall in homes. There are also potential health hazards related to this corrosive material. As such, it is important to find a way to identify Chinese drywall. Drywall can be tested for certain markers, such as strontium, sulfur, and carbonates to identify it as corrosive Chinese drywall. The laboratory preparation and analysis should be efficient and cost effective. The methods previously used, such as an X-ray fluorescence gun have had issues with getting a proper reading due to the layers of other materials found on the drywall, and instruments such as atomic absorption can only test for one metal at a time. This investigation is beneficial because it uses a novel technique. This experiment focused on developing a method for the ICP-AES, inductively coupled plasma-atomic emission spectroscopy, which could qualitatively identify the presence of sulfide compounds in drywall. The drywall samples were set up in a natural environment, and the presence of sulfide compounds were tested for with copper coupons. The oxidized copper was then put into an acidic solution, and real time analysis was used to immediately analyze the volatilized sulfide compounds. All of the Chinese drywall samples tested positive for sulfur. This means that this type of analysis can be used to show that drywall containing corrosive sulfide compounds can be positively identified as Chinese drywall

A Robot Navigation Algorithm for Moving Obstacles

In recent years, considerable progress has been made towards the development of intelligent autonomous mobile robots which can perform a wide variety of tasks. Although the capabilities of these robots vary significantly, each must have the ability to navigate within its environment from a starting location to a goal without experiencing collisions with obstacles in the process - a capability commonly referred to as robot navigation . Numerous algorithms for robot navigation have been developed which allow the robot to operate in static environments. However, little work has been accomplished in the development of algorithms which allow the robot to navigate in a dynamic environment. This thesis presents a mathematically-based navigation algorithm for a robot operating in a continuous-time environment inhabited by moving obstacles whose trajectories and velocities can be detected. In this methodology, the obstacles are represented as sheared cylinders to depict the areas swept out by the obstacle disks of influence over time. The robot is represented by the cone of positions it can reach by traveling at a constant speed in any direction. The methodology utilizes a three-dimensional navigation planning approach in which the search points, or tangent points, are the points in time at which the robot tangentially meets the obstacles. These tangent points are determined by calculating the intersection curves between the robot and the obstacles, and then using the first derivative of the intersection curves to make the tangent selections. Paths are created as sequences of these tangent points leading from the robot starting location to the goal, and are searched using the A* strategy, with a heuristic of the Euclidean distance from the tangent point to the goal. The main contribution of this thesis is the development of a methodology which produces optimal tangent paths to the goal for a dynamic robot environment. This feature is significant, since no other algorithm located in the literature survey as background to this thesis has shown the ability to produce paths with optimal properties

Chlamydomonas fla Mutants Reveal a Link Between Deflagellation and Intraflagellar Transport

Background: Cilia and flagella are often lost in anticipation of mitosis or in response to stress.There are two ways that a cell can lose its flagella: resorption or deflagellation. Deflagellationinvolves active severing of the axoneme at the base of the flagellum; this process is defective inChlamydomonas fa mutants. In contrast, resorption has been thought to occur as a consequence ofconstitutive disassembly at the tip in the absence of continued assembly, which requiresintraflagellar transport (IFT). Chlamydomonas fla mutants are unable to build and maintain flagelladue to defects in IFT.Results: fla10 cells, which are defective in kinesin-II, the anterograde IFT motor, resorb theirflagella at the restrictive temperature (33°C), as previously reported. We find that in standardmedia containing ~300 microM calcium, fla10 cells lose flagella by deflagellation at 33°C. Thistemperature-induced deflagellation of a fla mutant is not predicted by the IFT-based model forflagellar length control. Other fla mutants behave similarly, losing their flagella by deflagellationinstead of resorption, if adequate calcium is available. These data suggest a new model wherebyflagellar resorption involves active disassembly at the base of the flagellum via a mechanism withcomponents in common with the severing machinery of deflagellation. As predicted by this model,we discovered that deflagellation stimuli induce resorption if deflagellation is blocked either bymutation in a FA gene or by lack of calcium. Further support for this model comes from ourdiscovery that fla10-fa double mutants resorb their flagella more slowly than fla10 mutants.Conclusions: Deflagellation of the fla10 mutant at the restrictive temperature is indicative of anactive disassembly signal, which can manifest as either resorption or deflagellation. We proposethat when IFT is halted by either an inactivating mutation or a cellular signal, active flagellardisassembly is initiated. This active disassembly is distinct from the constitutive disassembly whichplays a role in flagellar length control

Heterogeneous Multi-Robot Cooperation

This report addresses the problem of achieving cooperation within small- to medium- sized teams of heterogeneous mobile robots. I describe a software architecture I have developed, called ALLIANCE, that facilitates robust, fault tolerant, reliable, and adaptive cooperative control. In addition, an extended version of ALLIANCE, called L-ALLIANCE, is described, which incorporates a dynamic parameter update mechanism that allows teams of mobile robots to improve the efficiency of their mission performance through learning. A number of experimental results of implementing these architectures on both physical and simulated mobile robot teams are described. In addition, this report presents the results of studies of a number of issues in mobile robot cooperation, including fault tolerant cooperative control, adaptive action selection, distributed control, robot awareness of team member actions, improving efficiency through learning, inter-robot communication, action recognition, and local versus global control

'Baptism of Fire': The First Year in the Life of a Newly Qualified Social Worker.

This paper describes research commissioned by Skills for Care South West to identify and track the learning and development needs of newly qualified social workers through their first year of employment. The perceptions of 22 newly qualified social workers based in statutory settings are reported concerning the effectiveness of the social work degree (England), their induction and probationary periods and their progress towards post-qualifying social work education as part of their continuing professional development. The perspectives of line managers, people who use services and carers are also discussed. Findings from the research suggest that the social work degree has been well received by most newly qualified social workers and highlights the perceived importance of a statutory placement for social work degree students. Key social work practice skills that require further development are identified and a rationale is presented for greater investment in the induction and probationary periods of newly qualified social workers

Chlamydomonas fla mutants reveal a link between deflagellation and intraflagellar transport

BACKGROUND: Cilia and flagella are often lost in anticipation of mitosis or in response to stress. There are two ways that a cell can lose its flagella: resorption or deflagellation. Deflagellation involves active severing of the axoneme at the base of the flagellum; this process is defective in Chlamydomonas fa mutants. In contrast, resorption has been thought to occur as a consequence of constitutive disassembly at the tip in the absence of continued assembly, which requires intraflagellar transport (IFT). Chlamydomonas fla mutants are unable to build and maintain flagella due to defects in IFT. RESULTS: fla10 cells, which are defective in kinesin-II, the anterograde IFT motor, resorb their flagella at the restrictive temperature (33°C), as previously reported. We find that in standard media containing ~300 microM calcium, fla10 cells lose flagella by deflagellation at 33°C. This temperature-induced deflagellation of a fla mutant is not predicted by the IFT-based model for flagellar length control. Other fla mutants behave similarly, losing their flagella by deflagellation instead of resorption, if adequate calcium is available. These data suggest a new model whereby flagellar resorption involves active disassembly at the base of the flagellum via a mechanism with components in common with the severing machinery of deflagellation. As predicted by this model, we discovered that deflagellation stimuli induce resorption if deflagellation is blocked either by mutation in a FA gene or by lack of calcium. Further support for this model comes from our discovery that fla10-fa double mutants resorb their flagella more slowly than fla10 mutants. CONCLUSIONS: Deflagellation of the fla10 mutant at the restrictive temperature is indicative of an active disassembly signal, which can manifest as either resorption or deflagellation. We propose that when IFT is halted by either an inactivating mutation or a cellular signal, active flagellar disassembly is initiated. This active disassembly is distinct from the constitutive disassembly which plays a role in flagellar length control