5,835 research outputs found

    Bioremediation of biodiesel and diesel contaminated soil by pseudomonas putida

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    As occurs to the diesel fuel, the commercialization of biodiesel and their diesel blends can cause environmental damages due to accidental spillage. Presence of these contaminants containing polyaromatic hydrocarbons (PAHs) in soil is toxic to humans, plants and soil microorganisms due to their recalcitrant and mutagenic or carcinogenic properties. Therefore, this study was conducted to suggest a new technique of treatment to clean up the biodiesel and diesel contaminated soil by Pseudomonas putida. Spill simulations with biodiesel, diesel and their blends in sandy gravel soil were performed according to previous study with some modification. Briefly, 200 mL of Pseudomonas putida was inoculated into soil samples: B5 (5% biodiesel + 95% diesel), B20 (20% biodiesel + 80% diesel), B50 (50% biodiesel + 50% diesel), B100 (100% biodiesel) and D100 (100% diesel). As a control sample, there is no addition of biodiesel and diesel into the sample. All samples were stored in the incubator at 35 ºC throughout the 24 days of treatment. Samples were analyzed for: soil particle size, moisture content, pH, total nitrogen (TN), orthophosphate, sulfate, total organic carbon (TOC), soxhlet extraction of PAHs and enumeration of Pseudomonas putida. The measurement of all testing parameters was carried out at interval of three days starting from Day 0 to Day 24 of bioremediation period. Results showed that the highest removal of total nitrogen (TN), orthophosphate, sulfate, total organic carbon (TOC) and PAHs were observed in the sample B100 with up to 70.43%, 69.47%, 68.08%, 97.66% and 96.28% removal, respectively. The degradation rates of PAHs and survival of Pseudomonas putida were also observed highest in the sample B100 with up to 0.149 mg/kg/day and 60 × 106 cfu/g, respectively. Based on these overall findings, it can be verified that the sample B100 has the higher biodegradability than other samples. According to results, it can conclude that, the capability and effectiveness of Pseudomonas putida as oil-biodegradable agent in soil bioremediation were proved and bioremediation of contaminated samples may be considered as a successful and feasible practice

    Saturn S-IB Stage assembly and test report, S-IB-1

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    Manufacture, assembly, and static tests of Saturn S-IB-1 stag

    A high-input impedance differential millivolt meter for use with solid ceramic oxygen electrolyte cells

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    Design factors are given for a high-input impedance differential millivolt meter designed, built, and tested as an inexpensive solid-state electronic system for use in measuring the electromotive force from solid ceramic oxygen electrolyte cells. A schematic diagram is included

    Efficient algorithms and a two-stage framework for autonomous exploration of complex 3D environments using a climbing robot

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    University of Technology Sydney. Faculty of Engineering and Information Technology.Enabling robots to autonomously explore complex 3D environments is crucial in facilitating the automation of many real-world tasks. There exist many algorithms for exploring unknown environments with autonomous robots. Most of these are restricted to the 2D case, or to cases where the robot can be abstracted as a holonomic point robot. Algorithms that deal with the 3D case restrict the robot’s possible positions to the 2D plane, or assume that the robot can freely move through any empty space, like an idealised quadrocopter. This thesis presents a two-stage exploration framework that allows robots to consider any adherable surface in a 3D environment as a potential position from which to conduct exploration. The framework is therefore suitable to any robotic platform that must at all times maintain contact with a surface, but where this surface need not be the floor plane. A Nearest Neighbours Exploration Approach (NNEA) is developed to accomplish exploration of the environment immediately surrounding the robot when the robot is fixed to a position on a surface. In this approach, the Next Best Viewpoint is selected first by evaluating and choosing between candidate viewpoints that are within a bounded range of the robot’s current position. NNEA is demonstrated in experiments in a real bridge environment for the case of a high degrees of freedom (DOF) robot arm with a fixed base. NNEA is shown to result in faster exploration times in the case of a high-DOF robot arm in a fixed base position. Four frontier detection algorithms are proposed and investigated for determining the set of frontiers—the boundary between known and unknown space—after each map update. The resulting frontiers are used to limit which candidate positions need to be considered for exploration. The novel frontier detection algorithms are compared to other state of the art algorithms and are found to be suited for efficient frontier detection in different situations. A novel graph-based method for selecting the Next Best Base location (NBB) is presented in which the map is used to create an updated graph of possible positions for the robot base, sampled from all surfaces. Positions that are sufficiently close to the frontiers are selected as candidate positions for the robot to move to next. The information that could be gained from each reachable candidate position is estimated. A cost function determines which candidate is the best to move to next, and the robot moves to that position to take another sequence of scans. This method is demonstrated in simulations and experiments to be efficient in minimising the computation required to select and move to the NBB. The exploration framework and the developed algorithms and approach are demonstrated in simulation in an environment made up of unconnected surfaces, large enough that the robot is required to repeatedly move through the environment in order to fully explore it. The framework is shown to result in efficient exploration of the observable environment

    Celecoxib decreases prostaglandin E\u3csub\u3e2\u3c/sub\u3e concentrations in nipple aspirate fluid from high risk postmenopausal women and women with breast cancer

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    Background Celecoxib inhibits PGE2 production in cancerous tissue. We previously reported that PGE2 levels in nipple aspirate fluid (NAF) and plasma were not decreased in women at increased breast cancer risk who received celecoxib 200 mg twice daily (bid). The endpoints of the current study were to determine if a short course of celecoxib 400 mg bid would decrease PGE2 levels in women 1) at increased breast cancer risk, and 2) with established breast cancer. Methods NAF and plasma samples were collected before, 2 weeks after taking celecoxib 400 mg bid, and two weeks after washout from 26 women who were at increased breast cancer risk. From 13 women with newly diagnosed breast cancer, NAF from the incident breast and plasma were collected before and on average 2 weeks after taking celecoxib. Additionally, in nine of the 13 women with breast cancer, NAF was collected from the contralateral breast. Results No consistent change in NAF or plasma PGE2 levels was noted in high risk premenopausal women. NAF PGE2 levels decreased after celecoxib administration in postmenopausal high risk women (p = 0.02), and in both the NAF (p = 0.02) and plasma (p = 0.03) of women with breast cancer. Conclusion Celecoxib 400 mg bid taken on average for 2 weeks significantly decreased NAF, but not plasma, PGE2 levels in postmenopausal high risk women, and decreased both NAF and plasma PGE2 levels in women with newly diagnosed breast cancer. PGE2 levels may predict celecoxib breast cancer prevention and treatment efficacy. Our observations are preliminary, and larger studies to confirm and extend these findings are warranted

    River Crake (at Bouthrey Bridge) freeze coring report

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    This is the River Crake (at Bouthrey Bridge) freeze coring report produced by Lancaster University in 1999. This study looks at fine materials in river Crake at Bouthrey Bridge that may have to be considered detrimental to successful salmonid spawning. Following an observed decline in quality of salmonid fisheries at the site an investigation was initiated to assess the extent of ingress of fine sediments into the spawning gravels. Fine sediments from one potential source, upstream riverbanks, are also compared to those isolated from the spawning gravels. The percentage by weight of fine sediments for the six freeze cores, was found to be lower than first expected, given the visual appearance of the reach. However the fines were found to be distributed evenly down the cores with a marked absence of an upper, coarse gravel armour layer. In addition the median grain size (D50) of the six samples was generally low, falling to 6mm for core 5. The low median grain size and the absence of coarse grained upper strata are considered detrimental to the success rate of salmonid spawning

    River Leith fluvial aufit. Final project report

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    This is the River Leith fluvial audit: Final project report produced by Lancaster University in 1998. Freeze cores extracted from the upper and lower ends of River Leith illustrate that the bed is highly compacted in the downstream reach. Fine material is locally derived from bedrock at depths of only 32 cms into the bed and in one core fine material is 66% of the extracted core. Levels of fines that are believed to be detrimental to fish are put at 20 to 30%. Reduced flow and stream power from water abstraction may lead to a greater infiltration of fine material if gravels are not regularly flushed through with flood flows. Infiltration of fine material can lead to river bed compaction and concretion. A small abstraction may have no effect on the morphology of a river if the reduced discharge is within the normal range of flows experienced. However if the impact on flows is small it is still possible that fine sediment problems will develop progressively and the effects may not be noticed for several years
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