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 $) and the marginal unit cost of phosphorus removal, expressed in ($/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

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,

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

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

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

Extended H? emission line sources from UWISH2

We present the extended source catalogue for the UKIRT Wide Field Infrared Survey for H2 (UWISH2). The survey is unbiased along the inner Galactic Plane from l ? 357° to l ? 65° and |b| ? 1.5° and covers 209 deg2. A further 42.0 and 35.5 deg2 of high dust column density regions have been targeted in Cygnus and Auriga. We have identified 33 200 individual extended H2 features. They have been classified to be associated with about 700 groups of jets and outflows, 284 individual (candidate) planetary nebulae, 30 supernova remnants and about 1300 photodissociation regions. We find a clear decline of star formation activity (traced by H2 emission from jets and photodissociation regions) with increasing distance from the Galactic Centre. About 60 per cent of the detected candidate planetary nebulae have no known counterpart and 25 per cent of all supernova remnants have detectable H2 emission associated with them

Modelling the Galactic distribution of free electrons

In this paper we test 8 models of the free electron distribution in the Milky Way that have been published previously, and we introduce 4 additional models that explore the parameter space of possible models further. These new models consist of a simple exponential thick disk model, and updated versions of the models by Taylor & Cordes and Cordes & Lazio with more extended thick disks. The final model we introduce uses the observed H-alpha intensity as a proxy for the total electron column density, also known as the dispersion measure (DM). We use the latest available data sets of pulsars with accurate distances (through parallax measurements or association with globular clusters) to optimise the parameters in these models. In the process of fitting a new scale height for the thick disk in the model by Cordes & Lazio we discuss why this thick disk cannot be replaced by the thick disk that Gaensler et al. advocated in a recent paper. In the second part of our paper we test how well the different models can predict the DMs of these pulsars at known distances. Almost all models perform well, in that they predict DMs within a factor of 1.5-2 of the observed DMs for about 75% of the lines of sight. This is somewhat surprising since the models we tested range from very simple models that only contain a single exponential thick disk to very complex models like the model by Cordes & Lazio. We show that the model by Taylor & Cordes that we updated with a more extended thick disk consistently performs better than the other models we tested. Finally, we analyse which sightlines have DMs that prove difficult to predict by most models, which indicates the presence of local features in the ISM between us and the pulsar. (abridged)Comment: 16 pages, 10 figures, 5 tables. Accepted for publication in the Monthly Notices of the RAS by the Royal Astronomical Society and Blackwell Publishin

Dark gas in the solar neighnorhood from extinction data

When modeling infrared or gamma-ray data as a linear combination of observed gas tracers, excess emission has been detected compared to expectations from known neutral and atomic gas as traced by HI and CO measurements, respectively. This excess might correspond to an additional gas component. This so-called "dark gas" (DG) has been observed in our Galaxy, as well as the Magellanic Clouds. For the first time, we investigate the correlation between visible extinction (Av) data and gas tracers on large scales in the solar neighborhood. Our work focuses on both the solar neighborhood (|b|>10\degr), and the inner and outer Galaxy, as well as on four individual regions: Taurus, Orion, Cepheus-Polaris and Aquila-Ophiuchus. Thanks to the recent production of an all-sky Av map, we first perform the correlation between Av and both HI and CO emission over the most diffuse regions, to derive the optimal (Av/NH)^(ref) ratio. We then iterate the analysis over the entire regions to estimate the CO-to-H2 conversion factor as well as the DG mass fraction. The average extinction to gas column-density ratio in the solar neighborhood is found to be (Av/NH)^(ref)=6.53 10^(-22) mag. cm^2, with significant differences between the inner and outer Galaxy. We derive an average XCO value of 1.67 10^(20) H2 cm^(-2)/(K km s^(-1)). In the solar neighborhood, the gas mass in the dark component is found to be 19% relative to that in the atomic component and 164$$ relative to the one traced by CO. These results are compatible with the recent analysis using Planck data within the uncertainties of our measurements. We estimate the ratio of dark gas to total molecular gas to be 0.62 in the solar neighborhood. The HI-to-H2 and H2-to-CO transitions appear for Av $\simeq$0.2 mag and Av$\simeq1.5$ mag, respectively, in agreement with theoretical models of dark-H2 gas.Comment: 9 pages, 4 figures, 1 table. Accepted for publication in A&A (in press

V2494 cyg: A unique FU ori type object in the cygnus OB7 complex

A photometric and spectral study of the variable star V2494 Cyg in the L 1003 dark cloud is presented. The brightness of the star, formerly known as HH 381 IRS, increased by 2.5 mag in R (probably in the 1980s) and since then has remained nearly constant. Since the brightness increase, V2494 Cyg has illuminated a bipolar cometary nebula. The stellar spectrum has several features typical of the FU Ori (FUor) type, plus it exhibits very strong Ha and forbidden emissionlines with high-velocity components. These emission lines originate in the Herbig-Haro (HH) jet near the star. The kinematic age of the jet is consistent with it forming at the time of the outburst leading to the luminosity increase. V2494 Cyg also produces a rather extended outflow; it is the first known FUor with both an observed outburst and a parsec-sized HH flow. The nebula, illuminated by V2494 Cyg, possesses similar morphological and spectral characteristics to Hubble's variable nebula (R Monocerotis/NGC 2261). © 2013 The Authors Published by Oxford University Press on behalf of the Royal Astronomical Society

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