Meeting the phosphorus consent with biological nutrient removal under UK winter conditions

It is estimated that up to 342 wastewater treatment plants (Wwtps) in England and Wales will require a phosphorus (P) consent by 2010. Although biological P removal is considered to be the most sustainable option for P removal, it has always been problematic for plants that remove both nitrogen and P due to the inadequate concentration of organic material during wet periods. Two biological nutrient removal (BNR) configurations, the Johannesburg (JHB) process and a combined JHB and five-stage Bardenpho process, were evaluated over a period of 2 years to assess the impact of sewage strength on bio-P removal. The JHB achieved an average effluent total phosphorus (TP) of 2.4 mg/L and the combined JHB and five-stage process averaged 1.4 mg/L effluent TP. The major problems affecting the performance of both configurations were: dissolved oxygen (DO) in the recycled mixed liquor, nitrate in the return activated sludge (RAS) and low influent biological oxygen demand (BOD) concentrations. Acetate dosing proved successful as a source of volatile fatty acids (VFAs) in the anaerobic zone during periods of low-strength sewage. An acetate dosing strategy based on the influent flow rate to the plant was found to be a simple and effective technique that ensured that a consent of <1 mg TP/L could be met.     

Textured Bi2Sr2Ca2Cu3O10+y tiles manufactured from sintered and plasma-sprayed precursors for magnetic shieldingtiles manufactured from sintered and plasma-sprayed precursors for magnetic shielding

Superconducting magnetic shields have potential weight advantages over conventional materials as efficient, light, shielding materials. Shielding properties in high fields depend on many material features, including alignment, critical current densities, and flux pinning. Diffusion texturing can produce grain alignment with the c-axis parallel to the sheet plane. In this article, the superconducting tile is made by bonding the ceramic precursor, SrCaCu₂, to a metal substrate before texture growth with Pb-Bi-O. The bonding can be produced by sintering or by plasma spraying. After diffusion texture growth, a tile with a superconducting transition temperature of 110 K and a critical current density greater than 2500 A/cm² has been manufactured and characterized.     

Beneficial effects of Tadenan therapy after two weeks of partial obstruction in the rabbit

Tadenan (Debat Laboratories, France) is a plant extract used in Europe for the treatment of micturition disorders associated with benign prostatic hypertrophy (BPH). Prior studies demonstrated that pretreatment of rabbits with Tadenan significantly reduced the contractile dysfunction observed after 2 weeks of partial outlet obstruction. The specific aim of the present study was to determine the effect of Tadenan therapy following the creation of partial outlet obstruction. Two sets of experiments were performed: one with mild and the other with severe outlet obstruction. For both sets of experiments, male New Zealand rabbits (3-5 kg) were separated into 3 groups of 5 rabbits each. Each rabbit in groups 1 and 2 was obstructed using standard methodology. Rabbits in group 3 served as controls and did not receive any surgery. After 2 weeks, each rabbit in group 1 received Tadenan orally at 100 mg/kg/day for 3 weeks; each rabbit in group 2 received vehicle (peanut oil). After 3 weeks of treatment (5 weeks after partial outlet obstruction), rabbits were anesthetized and cystometries were performed. Immediately after cystometry, the rabbits were euthanized, the bladder rapidly removed, and 4 longitudinal strips prepared and mounted in individual baths for contractile studies. The contractile responses to field stimulation, carbachol, adenosine-5'-triphosphate (ATP), and potassium chloride (KCl) were determined, as follows: (1) Bladder mass approximately doubled in the mildly obstructed groups. Bladder mass increased significantly (3-5-fold) in the severely obstructed groups. (2) Cystometrograms from the mildly obstructed rabbits treated with peanut oil showed low compliance, whereas those of the mildly obstructed rabbits treated with Tadenan showed normal compliance. The cystometrograms of all severely obstructed rabbits showed low compliance. (3) Mild obstruction caused small but significant decreases in the contractile response to field stimulation that were reversed by Tadenan treatment. No changes were noted in response to bethanechol, ATP, and KCl stimulation. (4) Severe obstruction caused significant decreases in the response of bladder strips to field stimulation and bethanechol. Following Tadenan therapy, there was a significant improvement in the response to high-frequency field stimulation and a substantial improvement in the response to bethanechol (response equal to control). No changes were noted in response to ATP and KCl stimulation. In conclusion, Tadenan treatment reversed the bladder dysfunctions induced by mild partial outlet obstruction, and resulted in improved bladder function in the severe model of outlet obstruction. These studies are consistent with previous studies showing that Tadenan pretreatment protects the bladder against the development of contractile dysfunctions.     

Correlation of EGTA and calcium-blocking agents on the response of the bladder to in vitro ischemia

The effects of repetitive field stimulation (model of hyperrelexia) on the responses of isolated strips of rabbit urinary bladder to FS and carbachol were evaluated under a variety of incubation conditions. Compared to control conditions, 2 h of repetitive FS in normal, oxygenated Tyrode's solution followed by incubation for 1 h with no stimulation resulted in a 50% decrease in contractile response to FS and a 30% decrease in the response to carbachol. Incubation in the absence of O2 and glucose was used as an in vitro model for ischemia. Repetitive stimulation during in vitro ischemia resulted in a significantly greater decrease in the contractile responses to FS and carbachol than did in vitro ischemia without repetitive stimulation. The magnitude of contractile dysfunctions in response to both stimuli were significantly reduced in the presence of EGTA (calcium chelator), diltiazem (calcium channel blocker) or pincidil (potassium channel opener). Incubation with thapsigargin (SR calcium uptake inhibitor) + ryanodine (SR calcium storage inhibitor) had no effect. The results of these studies indicate that inhibition of Ca2+ entry reduces the contractile dysfunctions induced by repetitive stimulation in the presence of in vitro ischemia. Inhibition of Ca2+i storage and release had no significant effect on the magnitude of contractile dysfunctions induced by repetitive stimulation an in vitro ischemia.     

Separate and combined effects of a cognitive map and a symbolic code in the learning of a modeled social skill (job interviewing).

Evaluated the incremental effects of a cognitive map (CM) and a symbolic code (SC) treatment (separately and in combination) relative to a standard modeling treatment (SMT) that generated equivalent demand characteristics. SMT in turn was compared to a no-treatment control condition (NT). Simulated job interviews were conducted 3 wks after treatment with 55 undergraduates who had been assigned to 1 of 4 treatments or NT. The Job Interview Rating Scale, knowledge scores, and speaking time were included in the measures of interviewing proficiency. Significant gains were attributable to CM on 4 of 6 social skills criteria. The SC and combination (CM plus SC) treatments produced significant improvement on all dependent variables. Evidence favoring SMT over NT was weak. Cost–benefit implications for the theoretically derived CM and SC treatments are discussed. (30 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fade slope analysis for Alaska, Florida, and New Mexico ACTSpropagation data at 20 and 27.5 GHz

This paper analyzes fade slope for the Alaska, Florida, and New Mexico Advanced Communications Technology Satellite (ACTS) propagation data at 20 and 27.5 GHz for the first two years of the experiment (December 1, 1993-November 30, 1995). The propagation experiment will continue to collect data for at least another 21 months. Fade slope is examined on a statistical basis for the three sites. The Florida and New Mexico receiver sites have very different weather characteristics but almost identical elevation angles, while the Alaska receiver terminal has an extremely low elevation angle. The cumulative statistics illustrate the relationship between fade slope, fade level, transmission frequency, and elevation angle for all three sites     

Market Dynamics and Local Policy Choices for Converged Systems: Case Study of Integrated Telecommunication Design and Deployment

Researchers have cogently presented the technical case for converged telecommunications systems. However, it is not clear how market-based telecommunications providers and local communities are embracing this technical argument as they design and adopt new telecommunication systems. This paper uses a case study approach to examine market and policy dynamics influencing converged network deployment in a mixed commercial and residential environment. Specifically, the article presents the overall telecommunications design and then analyzes several implementation alternatives proposed for a major urban redevelopment project in the greater Denver metropolitan area. These alternatives range from more traditional telecommunications solutions to fully converged networks. Based on this review, the paper analyzes the role of a layered policy approach to telecommunications regulation at the local level and how interoperability serves as a mediating condition before market convergence is achieved. Finally, the paper addresses public policy implications for encouraging adoption of fiber-IP based networks as well as research directions for assessing metropolitan adoption of converged systems.     

Does anhedonia in schizophrenia reflect faulty memory for subjectively experienced emotions?

The authors evaluated whether self-reported trait anhedonia in schizophrenia reflects faulty memory, such that patients are capable of experiencing pleasure while engaged in enjoyable activities but underestimate their pleasure in recalling these experiences. Thirty schizophrenia patients and 31 nonpatient control participants rated their emotional responses to pleasant and neutral foods and film clips and completed a surprise recall task for their emotions after a 4-hr delay. Despite reporting elevated trait anhedonia, patients did not significantly differ from control participants in immediate pleasant emotional responses to the stimuli or in delayed recall for these experiences. In-the-moment pleasure and short-term retention for emotional experiences thus appear to be relatively intact in schizophrenia. Alternative explanations for the hedonic deficit in this disorder are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)