1,425 research outputs found
Intermediate integer programming representations using value disjunctions
We introduce a general technique to create an extended formulation of a
mixed-integer program. We classify the integer variables into blocks, each of
which generates a finite set of vector values. The extended formulation is
constructed by creating a new binary variable for each generated value. Initial
experiments show that the extended formulation can have a more compact complete
description than the original formulation.
We prove that, using this reformulation technique, the facet description
decomposes into one ``linking polyhedron'' per block and the ``aggregated
polyhedron''. Each of these polyhedra can be analyzed separately. For the case
of identical coefficients in a block, we provide a complete description of the
linking polyhedron and a polynomial-time separation algorithm. Applied to the
knapsack with a fixed number of distinct coefficients, this theorem provides a
complete description in an extended space with a polynomial number of
variables.Comment: 26 pages, 5 figure
Assessment of Biosorption Activated Media under Roadside Swales for the Removal of Phosphorus from Stormwater
Stormwater runoff from highways is a source of pollution to surface water bodies and groundwater. Excess loadings of phosphorus in stormwater discharged to surface water bodies can result in eutrophication. Treatment of stormwater for phosphorus is necessary in order to sustain ecological and economical benefits related to aquatic resources. If phosphorus is removed, the water can be sustained for other uses, such as irrigation and industrial applications. The data presented in this paper is used to evaluate the treatment performance of a roadside biosorption activated media system with regards to the removal of total phosphorus and soluble reactive phosphorus from highway runoff. The evaluation also compares removal efficiencies and effluent concentrations using biosorption activated media (BAM) to that with sandy soil commonly found in the Florida area. The results presented in this paper indicate that BAM bio-filtration systems are a feasible treatment method for removing phosphorus from highway runoff. A discussion concerning the additional treatment and reuse of water by harvesting, as part of a Bio-filtration & Harvesting Swale System, is also presented in the paper
Floating Wetland Systems for Nutrient Removal in Stormwater Ponds
Wet detention ponds are frequently used in stormwater management systems as part of a treatment train for attenuation of flow and removal of pollutants. Wet detention ponds designed and operated according to commonly used standards and specifications remove nutrients but the removal of nitrogen has remained low, about 30-40% concentration reduction on a yearly basis. A Floating Treatment Wetland (FTW) composed of selected plants suspended in a wet detention pond was proposed in this research to improve the removal of nutrients before discharge from a pond
Achieving the Millennium Development Goals through mainstreaming nutrition: speaking with one voice.
At the most recent meeting of the Standing Committee on Nutrition of the UN system in Geneva in March of this year (2006) there was a dramatic shift in the tenor of the opening plenary session. Three very high-ranking officials of three of the largest implementing UN agencies (WHO UNICEF World Bank) along with WFP and FAO produced -- independently of one another -- a clear consistent message focusing on the importance of nutrition for development. In each case this was couched within the comparative advantage of each agency. It was also striking that none of the speakers came from a background of nutrition training -- one economist one public health physician one health economist and one development expert. All had been converted by enthusiastic nutrition colleagues within their particular agency and by long experience in many countries and an expanding evidence base. All referred to the same evidence base -- the Bellagio Child Survival Study Group and subsequent papers published not in nutrition or even public health journals but in medical journals (the Lancet and the British Medical Journal in particular) although the significance of this will not be discussed here. But all were somewhat perplexed as to why nutrition issues were not an automatic component of all national health and development programmes including within each agency. They had clearly used their considerable experience in the public sector to think this through especially the importance of having a common and consistent message. (excerpt
Stormwater Harvesting Using Retention and In-Line Pipes for Treatment Consistent with the new Statewide Stormwater Rule
Stormwater rules and regulations are evolving. Thus, there is a need for research that supports alternative methods for water quality treatment of runoff water. The information in this report supports the use of filtration media called Biosorption Activated Media (BAM) that improves runoff water quality. Runoff to impaired waters may need additional treatment or reduced volume of discharge to meet a mass discharge limitation. In addition, some nutrients in runoff waters may need to be removed before they percolate to nutrient sensitive areas such as aquifers with discharge to springs or estuaries. Thus, stormwater harvesting or reuse is another best management practice that can be used to reduce the mass of pollutants in runoff discharged to surface waters.
Harvesting of stormwater for a single user is typically done by direct use of the water from a pond provided there is no cross connection and that a screen filter is used. When contact with the general public is expected, irrigation quality water is needed. The water in a stormwater pond has to be treated by some form of filtration to provide irrigation quality water. Treatment methods considered within this report are those resulting from biosorption filtration media, commonly called BAM, and from disc technologies. When using BAM, the media can be placed in a pipe or other suitable containment and the runoff water or wet detention pond water passes through the filter in either a down-flow or up-flow configuration. Another option is to place BAM in a pipe within a pipe in a wet detention pond and draft the water through the pipe. This BAM pipe-in-pipe can then be moved from one location to another, and thus is considered to be a mobile treatment method. Some options for the use of BAM are called pipe treatment systems because of their practical installation configurations.
Harvesting can also occur after runoff water has infiltrated into the ground, such as from shoulder or swale areas adjacent to roadways. This infiltrated water can either be collected by compartments (pipes are common) or be allowed to further percolate into the ground until they reach a point of discharge.
A concern resulting from harvesting water from a wet detention pond is the potential effect on the surrounding wetlands when the water in a wet detention pond is lowered. Thus, a computer model was developed and tested to determine the safe yield of a wet detention pond as controlled by the harvesting schedule and the minimum ground water level at select points in the study area. This integrated surface and ground water model was used for Stormwater Harvesting and Assessment for Reduction of Pollution and is thus called the SHARP model. The model was tested at an interstate highway wet detention pond in Miramar, Florida.
BAM filtration media mixes were laboratory tested for pollution removal and filtration rates. The laboratory work was conducted in six inch diameter columns, and the media mix depth was equal to what was expected in a full-scale operating filter (2 feet depth is common). The media mixes were then installed in pipes placed in operation at existing wet detention ponds, and effectiveness in the removal of nutrients was documented.
A wet detention pond in Tampa receiving runoff from an urban watershed composed of highways, parking lots, and buildings was the site of the down-flow filter. The down-flow media filter for water from this wet detention pond was successful in removing pollution. Another wet detention pond in Sarasota County was used as a demonstration for an up-flow filter. This pond collects both highway and residential runoff. The up-flow filter operation was demonstrated to include a backwashing operation and at a filtration rate of up to 2 million gallons per day. Both ponds require installation of provisions for removing debris and with mechanisms to backwash the filter media. A reliable and redundant operation was demonstrated since the water quality in the wet detention ponds did not meet a majority of the irrigation water quality standards.
A mobile pipe-in-pipe system was also demonstrated, but application at a high rate of filtration provided marginal improvement in water quality. Due to this, a lower filtration rate was recommended. This system can also be used in emergency situations.
The water quality effectiveness and continual operation of disc filtration using water from an interstate highway wet detention pond in Miramar, Florida was also documented. A disc filter was an alternative to filtration using BAM. It provided reliability and redundancy in meeting irrigation quality standards.
A swale filter system using BAM was also demonstrated and water quality effectiveness documented. The BAM filter removed more pollutants relative to the use of parent soils documented as Type A-3 soils. The removal was especially significant when new sod was used on top of the BAM filter. Runoff not collected in the slope of the swale can be collected in the bottom of the swale if not transported. This collection can be enhanced with the use of exfiltration or French drains. Also, since filtration is assumed using at least two feet of media, the collected water can be reused. Example calculations for a BAM filter with a swale were presented.
Every time runoff water is not discharged, pollution removal can be expected. This pollution removal can be quantified and the total maximum daily load reduction estimated. Limited cost and removal information for these systems are presented
Green Residential Stormwater Management Demonstration: An Integrated Stormwater Management and Graywater System to Reduce the Quantity and Improve the Quality of Residential Water Discharges, Post CO Data Analysis
Structural and electrical properties of CuAlMo thin films prepared by magnetron sputtering
The structural and electrical properties of a low resistivity CuAlMo thin film resistor material were investigated. The thin films were grown on Al2O3 and glass substrates by direct current (dc) magnetron sputtering. The key electrical properties of sheet resistance, temperature coefficient of resistance (TCR) and resistance stability were investigated as a function of sputtering pressure and post-deposition heat treatment time and temperature. A low sputtering pressure range of 0.13 to 0.40 Pa produced CuAlMo films with sheet resistance in the range 0.1 to 0.2 Ω/□ and resistance stability of 0.45 to 0.65% with a TCR of − 90 ppm/°C which could be shifted to zero following annealing in air at 425 °C. Films grown at higher sputtering pressures of 0.53 to 0.80 Pa had increased sheet resistance in the range 0.4 to 0.6 Ω/□ and inferior stability of 0.8 to 1.7% with a more negative TCR of − 110 to − 180 ppm/°C which could not be shifted to zero following annealing. The stability of the films grown at 0.13 and 0.40 Pa could be further improved to < 0.25% with heat treatment, due to the formation of a protective aluminium oxide layer. A minimum dwell time of 3 h at 425 °C was required to stabilise the films and set the electrical properties
Identification and characterization of OSTL (RNF217) encoding a RING-IBR-RING protein adjacent to a translocation breakpoint involving ETV6 in childhood ALL
Genomic aberrations involving ETV6 on band 12p13 are amongst the most common chromosomal abnormalities in human leukemia. The translocation t(6;12)(q23;13) in a childhood B-cell acute lymphoblastic leukemia (ALL) cell line fuses ETV6 with the putative long non-coding RNA gene STL. Linking STL properties to leukemia has so far been difficult. Here, we describe a novel gene, OSTL (annotated as RNF217 in Genbank), which shares the first exon and a CpG island with STL but is transcribed in the opposite direction. Human RNF217 codes for a highly conserved RING finger protein and is mainly expressed in testis and skeletal muscle with different splice variants. RNF217 shows regulated splicing in B cell development, and is expressed in a number of human B cell leukemia cell lines, primary human chronic myeloid leukemia, acute myeloid leukemia with normal karyotype and acute T-ALL samples. Using a yeast two-hybrid screen, we identified the anti-apoptotic protein HAX1 to interact with RNF217. This interaction could be mapped to the C-terminal RING finger motif of RNF217. We propose that some of the recurring aberrations involving 6q might deregulate the expression of RNF217 and result in imbalanced apoptosis signalling via HAX1, promoting leukemia development
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Public health nutrition and food policy
C/O PUBLISHING DIVISION, WALLINGFORD,
ENGLAND, OXON, OX10 8D
The case for launch of an international DNA-based birth cohort study
The global health agenda beyond 2015 will inevitably need to broaden its focus from mortality reduction to the social determinants of deaths, growing inequities among children and mothers, and ensuring the sustainability of the progress made against the infectious diseases. New research tools, including technologies that enable high-throughput genetic and ‘-omics’ research, could be deployed for better understanding of the aetiology of maternal and child health problems. The research needed to address those challenges will require conceptually different studies than those used in the past. It should be guided by stringent ethical frameworks related to the emerging collections of biological specimens and other health related information. We will aim to establish an international birth cohort
which should assist low- and middle-income countries to use emerging genomic research technologies to address the main problems in maternal and child health, which are still major contributors to the burden of disease globally
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