ALTERNATIVES FOR FINANCING MUNICIPAL SERVICES: THE CASE OF UNIT-PRICED TRASH DISPOSAL

New policy is being developed that incorporates not only innovative means of disposal, including the integration of source reduction and recycling, but also innovative approaches to funding disposal of municipal solid waste (MSW). This study was conducted to determine if a higher marginal price for MSW disposal affected per capita waste generation in New Hampshire towns, how the existence of a pay-as-you-throw (PAYT) program influenced per capita MSW generation, and to attempt to determine which towns were most likely to adopt a PAYT program in the future. The results showed that average household size, existence of a capital improvement plan, and marginal price to dispose of waste were statistically significant influences, regardless of the variation of price in the PAYT program. Towns with PAYT programs currently being implemented produce 0.18 tons of MSW less waste per capita per year than towns without PAYT programs.Public Economics,

Characterization of Vacuum Facility Background Gas Through Simulation and Considerations for Electric Propulsion Ground Testing

The background gas in a vacuum facility for electric propulsion ground testing is examined in detail through a series of cold flow simulations using a direct simulation Monte Carlo (DSMC) code. The focus here is on the background gas itself, its structure and characteristics, rather than assessing its interaction and impact on thruster operation. The background gas, which is often incorrectly characterized as uniform, is found to have a notable velocity within a test facility. The gas velocity has an impact on the proper measurement of pressure and the calculation of ingestion flux to a thruster. There are also considerations for best practices for tests that involve the introduction of supplemental gas flows to artificially increase the background pressure. All of these effects need to be accounted for to properly characterize the operation of electric propulsion thrusters across different ground test vacuum facilities

Pipeline and Canal Downstream Control System For Recirculation - Patterson ID Case Study

Patterson ID in Central California has five long, along-the-contour lateral canals that flow northward from a main canal. The main canal operates on downstream control, providing excellent flexibility to heads of the laterals. The lateral canals operate with manual upstream control and have little storage. The classic tail-ender problem existed; spill from the tail end was necessary to avoid under-supplying tail-end customers. To eliminate the spill and to provide better flexibility, a system was designed and constructed to tie the ends of the five laterals together with pipes and pumps, with one central regulating reservoir. The automatic control system allows water to exit a lateral pool by gravity if that particular lateral end has too high a water level. Conversely, if the most downstream pool on a lateral canal drops, a VFD-equipped pump from a downhill lateral automatically supplies the correct flow rate to re-establish a constant water level. The same pipe is used for flow in both directions. Any excess flow from the system as a whole is automatically routed to the reservoir. Any deficit from the system as a whole is removed from the reservoir. The complete system is monitored by SCADA, so operators know where excesses or deficits occur, and can adjust flows at the heads of the laterals to compensate for mismatches at the ends of the laterals. The system has worked successfully for three irrigation seasons. The paper describes the control philosophy, design, costs, challenges, and benefits

Influence of supply-channel velocity on farm delivery meter gate flow measurement

The work presented here is an extension of previous papers that updated the calibration of round (Armco-type) meter gates (three sizes: 0.30, 0.46, and 0.61 m), developed ratings for rectangular gates (two sizes: 0.46 and 0.61 m) on round pipes, and examined errors and uncertainty related to using these devices for water discharge measurement. Previous works examined gate discharge ratings under low supply-channel flow velocity perpendicular to the gate discharge pipeline. Here, additional testing was conducted to test the hypothesis that higher velocities in the supply channel would show decreased meter gate flow compared to the low-velocity ratings, but that the published gate calibration method would still yield accurate flow-rate calculations. All testing was conducted in a test facility with the gate discharge pipe set perpendicular to the supply channel, as is common in field installations. Velocities up to 0.94 m=s (3.1 ft=s) were tested with the smaller gate and 0.66 m=s (2.2 ft=s) for all other gates. These velocities are on the upper end of velocities found in common earthen irrigation canals (and in many lined channels at the farm delivery level) in California. Interestingly, results indicate that the Froude number of the supply-channel flow did not have a statistically significant (at an α-level of 0.01) influence on gate discharge coefficients. Discharge percent error and uncertainty were examined to compare the discharge coefficients presented in the literature to the discharge measured during the testing at different supply-channel velocities. Under recommended operating conditions, the uncertainty was within ±5% without adjustments for supply-channel velocity. This extended work supports earlier recommendations that meter gates can be an accurate flow measurement device for farm water delivery flow measurement if installed and operated correctl

Crystal-Induced Inflammation: Studies of the Mechanism of Crystal-Membrane Interactions

Studies of the interactions of monosodium urate monohydrate (MSUM) crystals and calcium Pyrophosphate dihydrate triclinic (CPPD) crystals with biomembranes have been reviewed. Crystalmembrane binding and crystal-induced membranolysis have been studied using human erythrocytes as a model membrane system. The extent of MSUM-membrane binding was determined by incorporating a hydrophobic, fluorescent probe into the membranes, centrifugation to separate free membranes from membranes with bound crystals and quantitation of free membranes by measuring the total fluorescence intensity. The ability of MSUM and CPPD to hemolyse red cells was used as a measure of the membranolytic potential of the crystals. Fluorescence polarization studies showed that MSUM-membrane binding resulted in fluidization of the membrane. Cross-linking of the membrane proteins of the erythrocyte or the presence of divalent cations in the incubation medium inhibited MSUM induced hemolysis. These findings were explained by hypothesizing a pore model mechanism for MSUM induced membranolysis as follows. Binding of crystals to membranes induces the redistribution of transmembrane proteins into clusters or aggregates leading to pore formation. The pores permit the leakage of low molecular weight soluble compounds and ions across the membrane which is followed by osmotic rupture of the membran

Autologous hematopoietic cell transplantation in multiple sclerosis.

INTRODUCTION: Autologous haematopoietic cell transplantation (AHCT) is an evolving treatment avenue in multiple sclerosis (MS), which may be highly effective in controlling disease activity and improving disability. However, AHCT is associated with intrinsic toxicities and risks compared with conventional therapies. With growing experience in patient selection and treatment delivery, AHCT is increasingly considered an option in patients with aggressive disease that's responding poorly to disease modifying therapy. AREAS COVERED: This article provides an introduction to AHCT and looks at its development as a treatment for MS over the last 20 years. It also highlights potential mechanisms of action, patient selection, and future trends for this treatment approach. EXPERT OPINION: Currently published data suggest that AHCT's use is associated with significant reduction in MS disease activity and marked improvement in disability when used in patients with highly active relapsing remitting disease. Its long term safety and efficacy have not been fully evaluated but as increasing clinical trial data are published, its use is likely to grow. Further randomised controlled studies are needed to compare AHCT with standard disease modifying therapies and to optimise transplant regimens. Mechanistic studies may provide potential markers for response and a better understanding of disease pathogenesis

Validation of frequency and mode extraction calculations from time-domain simulations of accelerator cavities

The recently developed frequency extraction algorithm [G.R. Werner and J.R. Cary, J. Comp. Phys. 227, 5200 (2008)] that enables a simple FDTD algorithm to be transformed into an efficient eigenmode solver is applied to a realistic accelerator cavity modeled with embedded boundaries and Richardson extrapolation. Previously, the frequency extraction method was shown to be capable of distinguishing M degenerate modes by running M different simulations and to permit mode extraction with minimal post-processing effort that only requires solving a small eigenvalue problem. Realistic calculations for an accelerator cavity are presented in this work to establish the validity of the method for realistic modeling scenarios and to illustrate the complexities of the computational validation process. The method is found to be able to extract the frequencies with error that is less than a part in 10^5. The corrected experimental and computed values differ by about one parts in 10^$, which is accounted for (in largest part) by machining errors. The extraction of frequencies and modes from accelerator cavities provides engineers and physicists an understanding of potential cavity performance as it depends on shape without incurring manufacture and measurement costs

Microdosing and other phase 0 clinical trials: facilitating translation in Drug Development

Increasing costs of drug development and ethical concernsabout the risks of exposing humans and animals to novelchemical entities favor limited exposure clinical trials suchas microdosing and other phase 0 trials. An increasing bodyof research supports the validity of extrapolation from thelimited drug exposure of phase 0 approaches to the full,therapeutic exposure. An increasing number of applicationsand design options demonstrate the versatility and exibilitythese approaches offer to drug developers

Extreme environmental conditions reduce coral reef fish biodiversity and productivity

Tropical ectotherms are hypothesized to be vulnerable to environmental changes, but cascading effects of organismal tolerances on the assembly and functioning of reef fish communities are largely unknown. Here, we examine differences in organismal traits, assemblage structure, and productivity of cryptobenthic reef fishes between the world’s hottest, most extreme coral reefs in the southern Arabian Gulf and the nearby, but more environmentally benign, Gulf of Oman. We show that assemblages in the Arabian Gulf are half as diverse and less than 25% as abundant as in the Gulf of Oman, despite comparable benthic composition and live coral cover. This pattern appears to be driven by energetic deficiencies caused by responses to environmental extremes and distinct prey resource availability rather than absolute thermal tolerances. As a consequence, production, transfer, and replenishment of biomass through cryptobenthic fish assemblages is greatly reduced on Earth’s hottest coral reefs. Extreme environmental conditions, as predicted for the end of the 21st century, could thus disrupt the community structure and productivity of a critical functional group, independent of live coral loss

Improved Two-level Voltage Source Converter for High-Voltage Direct Current Transmission Systems

this paper presents an improved two-level voltage source converter for dc transmission systems with relatively low rated power and dc operating voltage. Unlike conventional two-level converter, the presented converter employs two distributed cell capacitors per three-phase; thus, do not contribute any current when converter is blocked during dc short circuit fault as in modular multilevel converter case. The use of three-phase cells is proven to be beneficial because the arm currents do not contain 2nd order harmonic currents, and cell capacitors tend to be small as they only experience high-order harmonic current associated with the switching frequency. For the same rated dc link voltage and switching devices, the rated power of the improved two-level converter will be twice that of the conventional two-level converter. Average, switching function and electromagnetic transient simulation models of the improved two-level converter are discussed and validated against detailed switch model. The viability of the improved two-level converter for HVDC applications is examined, considering dc and ac short circuit faults. Besides, reduced complexity of the control and power circuit of the improved two-level converter, it has been found that its transient responses to ac and dc faults are similar to that of the modular multilevel converter