481 research outputs found
Estimation of Costs of Phosphorus Removal In Wastewater Treatment Facilities: Adaptation of Existing Facilities
As part of a wider enquiry into the feasibility of offset banking schemes as a means to implement pollutant trading within Georgia watersheds, this is the second of two reports addressing the issue of estimating costs for upgrades in the performance of phosphorus removal in point-source wastewater treatment facilities. Earlier, preliminary results are presented in Jiang et al (2004) (Working Paper # 2004-010 of the Georgia Water Planning and Policy Center). The present study is much more detailed and employs an advanced software package (WEST®, Hemmis nv, Kortrijk, Belgium) for simulating a variety of treatment plant designs operating under typical Georgia conditions. Specifically, upgrades in performance, in a single step, from a plant working at an effluent limit of less than 2.0 mg/l phosphorus to one working with limits variously ranging between less than 1.0 mg/l to less than 0.05 mg/l phosphorus are simulated and the resulting costs of the upgrade estimated.Five capacities of plant are considered, from 1 MGD to 100 MGD. Three strategic, alternative designs for the facility are considered: the basic activated sludge (AS) process with chemical addition, the Anoxic/Oxic (A/O) arrangement of the AS process, and the Anaerobic/Aerobic/Oxic (A/A/O) arrangement of the AS process. Upgrades in performance are consistent with the logical alternatives for adapting these options. Cost comparisons are made primarily on the basis of the incremental cost of the upgrade, i.e., from the base-case, reference plant to that performing at the higher level, as expressed through the incremental Total Annual Economic Cost (TAEC; in /kg).For the most stringent upgrade, for example, to a plant generating an effluent with less than 0.05 mg/l phosphorus, these marginal costs -- the cost of the additional phosphorus removed as a result of the upgrade -- amount to something of the order of 150-425 $/kg, with the upper bound being associated with the smallest plant configuration (1 MGD). Working Paper Number 2005-001
Clinical Geography: A Proposal to Embrace Space, Place and Wellbeing through Person-Centered Practice
This essay envisions how geography can operationalize nuanced understandings of space and place to enrich the lives of individuals across the lifespan. We propose a focused integration of geography into person-centered practice: a clinical geography dedicated to working directly with people to promote optimal physical and mental health outcomes and wellbeing. Our proposal integrates spatial modifications to facilitate access and utility, behavioral interventions to maximize effectiveness in using space, and therapeutic engagement to nurture a deeper sense of ‘being in place’ that enhances wellbeing and quality of life. This focus is timely given societal instability and precariousness resulting from incongruous person-environment situations. In addition to investigating, explaining, and critiquing hazardous and inappropriate conditions, geographers might also directly and more immediately intervene with people who find themselves in such situations
Assessing the Market for Poultry Litter in Georgia: Are Subsidies Needed to Protect Water Quality?
Concerns about nutrient loads into our waters have focused attention on poultry litter applications. Like many states with a large poultry industry, Georgia recently designed a subsidy program to facilitate the transportation of poultry litter out of vulnerable watersheds. This paper uses a transportation model to examine the necessity of a poultry litter subsidy to achieve water protection goals in Georgia. We also demonstrate the relationship between diesel and synthetic fertilizer prices and the value of poultry litter. Results suggest that a well functioning market would be able to remove excess litter from vulnerable watersheds in the absence of a subsidy.fertilizer, phosphorous, poultry litter, subsidy, transportation model, water quality, Environmental Economics and Policy, Marketing, Q12, Q13, Q25, Q53,
The Structure of Molecular Clouds: I - All Sky Near Infrared Extinction Maps
We are studying the column density distribution of all nearby giant molecular
clouds. As part of this project we generated several all sky extinction maps.
They are calculated using the median near infrared colour excess technique
applied to data from the Two Micron All-Sky Survey (2MASS). Our large scale
approach allows us to fit spline functions to extinction free regions in order
to accurately determine the colour excess values. Two types of maps are
presented: i) Maps with a constant noise and variable spatial resolution; ii)
Maps with a constant spatial resolution and variable noise. Our standard Av map
uses the nearest 49 stars to the centre of each pixel for the determination of
the extinction. The one sigma variance is constant at 0.28mag Av in the entire
map. The distance to the 49th nearest star varies from below 1arcmin near the
Galactic Plane to about 10arcmin at the poles, but is below 5arcmin for all
giant molecular clouds (|b|< 30degr). A comparison with existing large scale
maps shows that our extinction values are systematically larger by 20% compared
to Dobashi et al. and 40% smaller compared to Schlegel et al.. This is most
likely caused by the applied star counting technique in Dobashi et al. and
systematic uncertainties in the dust temperature and emissivity in Schlegel et
al.. Our superior resolution allows us to detect more small scale high
extinction cores compared to the other two maps.Comment: 39 pages, 3 tables, 54 figures, accepted for publication by MNRAS, a
version with higher resolution figures can be found at
http://astro.kent.ac.uk/extinction/index.htm
Industrial precipitation of zirconyl chloride: the effect of pH and solution concentration on calcination of zirconia
In situ and ex situ X-ray diffraction, and transmission electron microscopy were used to investigate thecalcination of four samples of zirconia manufactured using two different zirconia reactant solution concentrations (0.81M and 1.62M) with precipitation carried out at pH 3 and 12. The calcinations wereinvestigated over the temperature range from room temperature to 1000"C. It was found that varyingthe precipitation conditions resulted in differing calcination routes; it is believed that variations in particlesize and initial degree of hydration are responsible for these differences. It was also found that theinitial phase produced after calcination was tetragonal zirconia, which underwent a process of crystallitegrowth to a size of # 30nm before transformation from tetragonal to monoclinic
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Minimal breast milk transfer of rituximab, a monoclonal antibody used in neurological conditions.
ObjectiveTo determine the transfer of rituximab, an anti-CD20 monoclonal antibody widely used for neurologic conditions, into mature breast milk.MethodsBreast milk samples were collected from 9 women with MS who received rituximab 500 or 1,000 mg intravenous once or twice while breastfeeding from November 2017 to April 2019. Serial breast milk samples were collected before infusion and at 8 hours, 24 hours, 7 days, and 18-21 days after rituximab infusion in 4 patients. Five additional patients provided 1-2 samples at various times after rituximab infusion.ResultsThe median average rituximab concentration in mature breast milk was low at 0.063 μg/mL (range 0.046-0.097) in the 4 patients with serial breast milk collection, with an estimated median absolute infant dose of 0.0094 mg/kg/d and a relative infant dose (RID) of 0.08% (range 0.06%-0.10%). Most patients had a maximum concentration at 1-7 days after infusion. The maximum concentration occurred in a woman with a single breast milk sample and was 0.29 μg/mL at 11 days postinfusion, which corresponds with an estimated RID of 0.33%. Rituximab concentration in milk was virtually undetectable by 90 days postinfusion.ConclusionsWe determined minimal transfer of rituximab into mature breast milk. The RID for rituximab was less than 0.4% and well below theoretically acceptable levels of less than 10%. Low oral bioavailability would probably also limit the absorption of rituximab by the newborn. In women with serious autoimmune neurologic conditions, monoclonal antibody therapy may afford an acceptable benefit to risk ratio, supporting both maternal treatment and breastfeeding
About the nature of Mercer14
We used UKIRT near infrared (NIR) broad band JHK photometry, narrow band
imaging of the 1-0S(1) molecular hydrogen emission line and mid infrared
Spitzer IRAC data to investigate the nature of the young cluster Mercer14.
Foreground star counts in decontaminated NIR photometry and a comparison with
the Besancon Galaxy Model are performed to estimate the cluster distance. This
method yields a distance of 2.5kpc with an uncertainty of about 10% and can be
applied to other young and embedded clusters. Mercer14 shows clear signs of
ongoing star formation with several detected molecular hydrogen outflows, a
high fraction of infrared excess sources and an association to a small gas and
dust cloud. Hence, the cluster is less than 4Myrs old and has a line of sight
extinction of A_K=0.8mag. Based on the most massive cluster members we find
that Mercer14 is an intermediate mass cluster with about 500Mo.Comment: 10pages, 2tables, 5figures, accepted for publication by MNRAS, a
version with higher resolution figures can be found at
http://astro.kent.ac.uk/~df
A furnace and environmental cell for the in situ investigation of molten salt electrolysis using high-energy X-ray diffraction
This paper describes the design, construction and implementation of a relatively large controlled-atmosphere cell and furnace arrangement. The purpose of this equipment is to facilitate the in situ characterization of materials used in molten salt electrowinning cells, using high-energy X-ray scattering techniques such as synchrotron-based energy-dispersive X-ray diffraction. The applicability of this equipment is demonstrated by quantitative measurements of the phase composition of a model inert anode material, which were taken during an in situ study of an operational Fray-Farthing-Chen Cambridge electrowinning cell, featuring molten CaCl(2) as the electrolyte. The feasibility of adapting the cell design to investigate materials in other high-temperature environments is also discussed
A very luminous, highly extinguished, very fast nova - V1721 Aquilae
Fast novae are primarily located within the plane of the Galaxy, slow novae
are found within its bulge. Because of high interstellar extinction along the
line of sight many novae lying close to the plane are missed and only the
brightest seen. One nova lying very close to the Galactic plane is V1721
Aquilae, discovered in outburst on 2008 September 22. Spectra obtained 2.69
days after outburst revealed very high expansion velocities (FWHM ~6450 km/s).
In this paper we have used available pre- and post-outburst photometry and
post-outburst spectroscopy to conclude that the object is a very fast,
luminous, and highly extinguished A_V=11.6+/-0.2) nova system with an average
ejection velocity of ~3400 km/s. Pre-outburst near-IR colours from 2MASS
indicate that at quiescence the object is similar to many quiescent CNe and
appears to have a main sequence/sub-giant secondary rather than a giant. Based
on the speed of decline of the nova and its emission line profiles we
hypothesise that the axis ratio of the nova ejecta is ~1.4 and that its
inclination is such that the central binary accretion disc is face-on to the
observer. The accretion disc's blue contribution to the system's near-IR
quiescent colours may be significant. Simple models of the nova ejecta have
been constructed using the morphological modelling code XS5, and the results
support the above hypothesis. Spectral classification of this object has been
difficult owing to low S/N levels and high extinction, which has eliminated all
evidence of any He/N or FeII emission within the spectra. We suggest two
possibilities for the nature of V1721 Aql: that it is a U Sco type RN with a
sub-giant secondary or, less likely, that it is a highly energetic bright and
fast classical nova with a main sequence secondary. Future monitoring of the
object for possible RN episodes may be worthwhile, as would archival searches
for previous outbursts.Comment: 9 pages 10 figures, accepted for publication in A&A. Abstract has
been slightly shortened from published versio
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