3 resultados para Scaling and root planing

em Brock University, Canada


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The effect that plants {Typha latifolia) as well as root-bed medium physical and chemical characteristics have on the treatment of primary treated domestic wastewater within a vertical flow constructed wetland system was investigated. Five sets of cells, with two cells in each set, were used. Each cell was made of concrete and measured 1 .0 m X 1 .0 m and was 1.3 m deep. Four different root-bed media were tested : Queenston Shale, Fonthill Sand, Niagara Shale and a Michigan Sand. Four of the sets contained plants and a single type of root-bed medium. The influence of plants was tested by operating a Queenston Shale set without plants. Due to budget constraints no replicates were constructed. All of the sets were operated independently and identically for twenty-eight months. Twelve months of data are presented here, collected after 16 months of continuous operation. Root-bed medium type did not influence BOD5 removal. All of the sets consistently met Ontario Ministry of Environment (MOE) requirements (<25 mg/L) for BOD5 throughout the year. The 12 month average BOD5 concentration from all sets with plants was below 2.36 mg/L. All of the sets were within MOE discharge requirements (< 25 mg/L) for suspended solids with set effluent concentrations ranging from 1.53 to 14.80 mg/L. The Queenston Shale and Fonthill Sand media removed the most suspended solids while the Niagara Shale set produced suspended solids. The set containing Fonthill Sand was the only series to meet MOE discharge requirements (< Img/L) for total phosphorus year-round with a twelve month mean effluent concentration of 0.23 mg/L. Year-round all of the root-bed media were well below MOE discharge requirements (< 20mg/L in winter and < 10 mg/L in sumnner) for ammonium. The Queenston Shale and Fonthill Sand sets removed the most total nitrogen. Plants had no effect on total nitrogen removal, but did influence how nitrogen was cycled within the system. Plants increased the removal of suspended solids by 14%, BOD5 by 10% and total phosphorus by 22%. Plants also increased the amount of dissolved oxygen that entered the system. During the plant growing season removal of total phosphorus was better in all sets with plants regardless of media type. The sets containing Queenston Shale and Fonthill Sand media achieved the best results and plants in the Queenston Shale set increased treatment efficiency for every parameter except nitrogen. Vertical flow wetland sewage treatment systems can be designed and built to consistently meet MOE discharge requirements year-round for BOD5, suspended solids, total phosphorus and ammonium. This system Is generally superior to the free water systems and sub-surface horizontal flow systems in cold climate situations.

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Abstract: Root and root finding are concepts familiar to most branches of mathematics. In graph theory, H is a square root of G and G is the square of H if two vertices x,y have an edge in G if and only if x,y are of distance at most two in H. Graph square is a basic operation with a number of results about its properties in the literature. We study the characterization and recognition problems of graph powers. There are algorithmic and computational approaches to answer the decision problem of whether a given graph is a certain power of any graph. There are polynomial time algorithms to solve this problem for square of graphs with girth at least six while the NP-completeness is proven for square of graphs with girth at most four. The girth-parameterized problem of root fining has been open in the case of square of graphs with girth five. We settle the conjecture that recognition of square of graphs with girth 5 is NP-complete. This result is providing the complete dichotomy theorem for square root finding problem.

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Edward W. Bowslaugh (1843-1923) was the son of Jacob and Anna (Beamer) Bowslaugh. Edward Bowslaugh married Mary Southward, and the couple had six children, Edgar Morley, Edward Freeman, twins Alfred Malcolm and Alice Mary, Annie Olivia, John Jacob and Mabel Florence. Edward W. Bowslaugh was a farmer, contractor and owner of the Grimsby Planing Mills in Grimsby, Ont. and Bowslaugh’s Planing Mill in Kingsville, Ont. The mills manufactured door and sash trim and other wood related products. Some customers contracted the firm to provide wood products for cottages being built at Grimsby Park, the Methodist camp ground. Some time before 1885 Edward Bowslaugh and his family moved to Kingsville, Ont. to open up a new planing mill and door and sash manufactory. He later sold the Grimsby Planing Mills to Daniel Marsh. The diaries and account books include many names of workers as well as friends and family members residing in the Grimsby and Kingsville areas. James M. Bowslaugh (1841-1882) was the son of Jacob and Anna (Beamer) Bowslaugh. James married first Anna Catharine Merritt and after her death in 1875 he married Mary Gee in 1877. James and Anna had three children, Eliza, James Herbert, George Hiram, all died very young. James and Mary Gee had one son, Charles Leopold Kenneth Frederich Bowslaugh, b. 1881. James Bowslaugh was a farmer and lumberman, much like his younger brother Edward. James’ early diaries often note the activities of himself and his brother Edward. Both Edward and James were heavily involved in the Methodist church, teaching or leading Sunday school and attending prayer meetings. Alfred M. Bowslaugh b. 1873 was the son of Edward W. Bowslaugh and his wife Mary Southward. The school notebook is from his days as a student in Kingsville, Ont.