Variability and polarization in the inner jet of 3C395

We present new results on the parsec-scale jet of the quasar 3C395, derived from VLBI polarization sensitive observations made in 1995.91 and 1998.50 at 8.4, 15.4 and 22.2 GHz. The observations show a complex one-sided jet extending up to 20 mas, with a projected magnetic field essentially aligned with the radio jet. The emission is strongly dominated, in total intensity and polarization, by the core and the inner jet region (of ~3 mas length). We have studied the details of this dominant region finding clear structural variations during this ~2.5 years period, in contrast with the apparent quietness of the jet structure inferred from lower resolution VLBI observations. We observe the ejection of a new component from the core and variations in the degree of polarization of the inner jet components. We estimate a high Faraday Rotation Measure close to the core, with a strong decrease along the inner jet.Comment: 7 pages, 4 figures, A&A in pres

DNA sequencing supports the reinstatement of Pycnolejeunea glauca from synonymy of Cheilolejeunea intertexta, as Cheilolejeunea glauca comb. nov.

Pycnolejeunea glauca, originally described by Stephani based on a collection in New Zealand by William Colenso, was placed by Grolle into the synonymy of the paleotropical species Cheilolejeunea intertexta with a type from Micronesia. In this study, we generated DNA sequences from a recently-collected sample of P. glauca and compared them with published sequences of C. intertexta from China. Pycnolejeunea glauca was recovered in the phylogenetic analyses as sister to C. nipponica, whereas C. intertexta grouped in another clade with C. vittata and C. streimannii. The analysis justifies the reinstatement of P. glauca as the new combination Cheilolejeunea glauca, a New Zealand endemic. Descriptions and illustrations are provided of key features of this species together with data on its position in the phylogeny of the genus

Concentration and Extraction of Phosphorous from Swine Manure Slurries (as Struvite)

Excessive loading of phosphorus (P) onto agricultural lands has been recognized as a threat to surface water quality. Forced precipitation of struvite (MgNH4PO4•6H2O) from animal waste slurries prior to land application can reduce dissolved reactive P levels in manure slurries. It also offers the potential to recover excess phosphorus from manures and move it to cropping areas that require phosphorus fertilizer inputs. Past work indicates that ~90% of the soluble phosphorus can be concentrated into a precipitate following chemical amendment. This study will provide important information regarding the feasibility of phosphorus recovery as a means of balancing swine manure nutrient content with crop needs. Given the expanding regulations regarding phosphorus management, it is important to develop and test phosphorus management strategies. The sustainability of many animal operations in their current locations will depend upon their ability to meet new regulations requiring phosphorus management as well as nitrogen management

The inner kiloparsec of the jet in 3C264

We present new multi-frequency EVN, MERLIN and VLA observations of the radio source 3C264, sensitive to linear scales ranging from the parsec to several kiloparsecs. The observations confirm the existence of regions with different properties in the first kiloparsec of the jet. The most remarkable feature is the transition between a well collimated narrow jet at distances from the core below 80 pc, to a conical-shaped wide jet, with an opening angle of 20 degrees. Another change of properties, consisting of an apparent deflection of the jet ridge line and a diminution of the surface brightness, occurs at a distance of 300 pc from the core, coincident with the radius of a ring observed at optical wavelengths. Our observations add new pieces of information on the spectrum of the radio-optical jet of 3C264, with results consistent with a synchrotron emission mechanism and a spectrum break frequency in the infrared. Brightness profiles taken perpendicularly to the jet of 3C264 are consistent with a spine brightened jet at distances below 100 pc from the core, and an edge-brightened jet beyond, which can be interpreted as evidence of a transverse jet velocity structure. Our observations do not allow us to distinguish between the presence of a face--on dust and gas disk at the center of the host galaxy of 3C264, or rather an evacuated bubble. However, the properties of the jet structure, the changes in the polarization angle, and the plausible jet orientation can be naturally brought into agreement in the bubble scenario.Comment: 10 pages, 9 figures, accepted in A&

Molecular and morphological evidence support the reinstatement of Cheilolejeunea comitans from synonymy of C. krakakammae.

In 2006 Cheilolejeunea comitans (Hook f. and Taylor) R.M.Schust., previously treated as endemic to New Zealand and Australia, was placed in synonymy of C. krakakammae (Lindenb.) R.M.Schust., a taxon with an African type. Here we generated DNA sequences from samples of New Zealand C. comitans and compared them with published sequences for C. krakakammae from China. The molecular evidence, together with a new analysis of morphological evidence from selected samples of C. comitans, and from the types and descriptions of C. krakakammae, justify the reinstatement of C. comitans

Performance of a Pilot-Scale Air Sparged Continuous Flow Reactor and Hydrocyclone for Struvite Precipitation and Removal from Liquid Swine Manure

The objective of this research was to test a pilot-scale air sparged tank reactor (ASTR) and the ASTR in combination with a hydrocyclone (called the pilot-scale ASTR-hydrocyclone system) on two swine manure slurries for struvite-based (MgNH4PO4-6H2O) phosphorus removal and recovery. The pilot-scale ASTR system operated at flow rates of 80 to 115 L/min and was based on the bench-scale design from Shepherd et al. (2007). The ASTR effluent was processed using a hydrocyclone separator for struvite separation and total phosphorus (TP) recovery. The pilot-scale ASTR-hydrocyclone system provided a 92% reduction of dissolved reactive phosphorus (DRP) in manure slurry from a swine finishing facility concrete storage tank and a 91% reduction of DRP in manure slurry collected from a swine finishing facility deep-pit under floor collection system. The pilot-scale ASTR-hydrocyclone system removed 18% of TP in swine manure from a concrete storage tank and 9% to 14% of TP in swine manure slurry from a deep-pit under floor collection system. The low TP recovery was attributed to the hydrocyclones inability to provide effective struvite separation as operated. Full-scale economics and implementation of the tested struvite-based phosphorus removal is discussed. A case study of a typical Iowa deep-pit swine production facility (10,000 head/year) indicated that the annual cost of struvite-based phosphorus removal using this system would be approximately $8.88/finished pig or$0.035/L manure slurry treated ($ 0.134/gal). This cost often exceeds producer\u27s profit margins; this indicates that struvite-based phosphorus removal using this ASTR-hydrocyclone system in swine finisher manure slurries is not currently economically viable

Validation of a Low Cost Flow Measurement System for Monitoring Vegetative Treatment System Performance

In 2006, the Iowa Department of Natural Resources issued National Pollution Discharge Elimination System (NPDES) permits to six feedlots participating in research on the use of vegetative treatment systems (VTSs) to control beef feedlot runoff. While Iowa State University monitors releases from the research portion of these sites, the producers are required to monitor releases from the non-research portions. Additionally, non-research site producers with VTSs and NPDES permits are required to monitor system releases. They are required to measure release volume and collect a sample for analysis. Automated, research oriented open channel flow measurement systems typically cost $7,500 to employ. Muhlbauer et. al (2007) developed a low cost monitoring system (LMS) designed to measure open channel flow from a VTS with a total cost of$1,600. Testing of the LMS by Muhlbauer et. al. (2007) across flow events ranging from one to six hours indicated a mean accuracy of 90.6% in comparison to a flow meter equipped ISCO 6712 portable sampler using a .46m (18”) fiberglass H-flume. Further cost reduction options for a producer include fabrication of a metal H-flume, reducing total system cost to $850. This paper compares the performance of the LMS for estimating both short and longer duration flow events and performance of the fabricated metal flume. The LMS flow measurements were compared to an ISCO 6712 portable sampler and a Krohne Optiflux 4000 flow meter in twelve field tests lasting one and six hours with an accuracy of 88.5% in comparison to the Krohne. Relative to a commercial fiberglass flume, the three fabricated flumes had a mean percent accuracy of 98%

Magnetic Fields in Quasar Cores II

Multi-frequency polarimetry with the Very Long Baseline Array (VLBA) telescope has revealed absolute Faraday Rotation Measures (RMs) in excess of 1000 rad/m/m in the central regions of 7 out of 8 strong quasars studied (e.g., 3C 273, 3C 279, 3C 395). Beyond a projected distance of ~20 pc, however, the jets are found to have |RM| < 100 rad/m/m. Such sharp RM gradients cannot be produced by cluster or galactic-scale magnetic fields, but rather must be the result of magnetic fields organized over the central 1-100 pc. The RMs of the sources studied to date and the polarization properties of BL Lacs, quasars and galaxies are shown to be consistent so far with the predictions of unified schemes. The direct detection of high RMs in these quasar cores can explain the low fractional core polarizations usually observed in quasars at centimeter wavelengths as the result of irregularities in the Faraday screen on scales smaller than the telescope beam. Variability in the RM of the core is reported for 3C 279 between observations taken 1.5 years apart, indicating that the Faraday screen changes on that timescale, or that the projected superluminal motion of the inner jet components samples a new location in the screen with time. Either way, these changes in the Faraday screen may explain the dramatic variability in core polarization properties displayed by quasars.Comment: Accepted to the ApJ. 27 pages, 9 figures including figure 6 in colo