The effect of fly ash on fluid dynamics of CO2 scrubber in coal-fired power plant

Uncaptured fly ash and/or suspended solids from wet flue gas desulfurization (WFGD) scrubbing solutions are one of several factors that will influence the performance and robustness of carbon dioxide capture systems in coal-fired power plants which will be installed prior to the exhaust stack. In this study, a 100 mm ID packed column scrubber was tested with different concentrations of ash in various chemical solutions to evaluate the influence of solids on the fluid dynamics of the packing material. Data reported here are collected from three solutions including water, 30 wt% MEA (monoethanolamine), and 20 wt% potassium carbonate. The packing selected for this study was a 16 mm polypropylene pall rings. Compressed air was used to simulate flue gas at near ambient temperature and pressure.     

The rhetoric and reality of housing choice: The role of urban consolidation

In Australia, growth at the fringe has been seen as an inevitable response to a lack of affordable housing in the inner and middle zones of the major metropolitan cities. Urban consolidation was seen as one way of improving housing affordability and increasing housing choices and, at the same time, constraining outward growth. It will do so only if households forego past preferences for ownership of a detached house. This paper examines the contribution urban consolidation has made to meeting affordability and choice objectives by providing some insights into whether households are trading off tenure choices for lifestyle choices based on location and dwelling type. It also provides information on the extent of spatial polarisation of income that has contributed to the observed outcomes.     

Ductile fracture behaviour under Mode I loading using rousellier ductile damage theory

The aim of this study is to investigate the ductile fracture behaviour under Mode I loading using 5A533B pressure vessel steel. Experiments consist of the Round Notch Bar Test (RNB), Single Edge Crack Bending Test (SECB), and V-Notch Bar Test (VNB). Results from the RNB test were used to tune the damage modelling constant. The other tests were performed to acquire the J-resistance curves and to confirm the damage constants. Microstructural observation includes the measurement of crack profile to obtain the roughness parameter. Finally, simulation using Rousellier Ductile Damage Theory (RDDT) was carried out with 4-node quadrilateral element (L _c =O.25 mm), For the crack advance, the failed element removal technique was adopted with a β criterion. In conclusion, the predicted simulation using RDDT showed a good agreement with the experimental results. A trial using a roughness parameter was made for a new evaluation ofJ-resistance curve, which is more conservative than the conventional one.     

The Parlay Network API Specification

New business opportunities have emerged for network operators to offer a new generation of interfaces directly to solution providers that expose information and control in various intelligent networks. The paper describes the commercial rationale and operational benefits of these application level interfaces. The Parlay Group has defined application programming interfaces (APIs) to expose network capabilities including wireline, mobile, IP QoS, and messaging to external enterprises. The Parlay Group and the API specification are described together with an illustration of how the API could be used to create an enterprise workflow solution that integrates capabilities in different networks.     

Remediation of methyl iodide in aqueous solution and soils amended with thiourea

Methyl iodide (MeI) is considered a very promising fumigant alternative to methyl bromide (MeBr) for controlling soil-borne pests. Because atmospheric emission of highly volatile fumigants contributes to air pollution, feasible strategies to reduce emissions are urgently needed. In this study, thiourea (a nitrification inhibitor) was shown to accelerate the degradation of MeI in soil and water. In aqueous solution, the reaction between MeI and thiourea was independent of pH, although the rate of MeI hydrolysis increased in alkaline solution. Substantial increases in the rate of MeI dissipation were observed in thiourea-amended soils. Transformation of MeI by thiourea in aqueous solution was by a single chemical reaction process, while MeI degradation in thiourea-amended soil apparently involved a catalytic mechanism. The electron delocalization between the thiourea molecule and the surfaces of soil particles is energetically favorable and would increase the nucleophilic reactivity of the thiono group toward MeI, resulting in an enhancement of the dissipation rate. The soil half-life for MeI was reduced from >300 h for unamended soils to only a few hours in soil or sand amended with thiourea at a 2:1 molar ratio (thiourea:MeI). The MeI transformation rate in thiourea-amended soil increased with increasing soil temperature and decreasing soil moisture. Therefore, spraying thiourea on the soil surface to form a "reactive surface barrier" may be an effective and innovative strategy for controlling fumigant emissions to the atmosphere and for improving environmental protection.     

An integrated population,economic, and water resource model to address sustainable development questions for Botswana

Abstract:

An integrated population, economic, and water resource model was developed to address sustainable development questions for Botswana. raditionally, water resources planning models have considered the implications of different assumptions of population and economic growth on the sustainability of existing water resources supply; however, this model extends that capability to consider feedbacks from one model component to another. For example, the model has the unique capability to examine implications of changing water‐related diarrhea incidence on the health of the HIV/AIDS population. Investments in water supply and sanitation or in HIV/AIDS medication impact the health and productivity of the population. The water model uses a physically‐based hydrologic rainfall‐runoff model with surface and groundwater components to produce monthly runoff and groundwater recharge at the watershed scale. Botswana is divided into socioeconomic regions, and the water resources infrastructure is characterized by virtual reservoirs in each. The demographic sub‐model is a standard multi‐cohort model that forecasts the population by age, sex, rural or urban residence, education level, and HIV/AIDS status. The economic sub‐model is a computable general equilibrium model with three components: agriculture, non‐agricultural exports, and non‐tradables. The model runs an ensemble of scenarios, including climate change, HIV/AIDS, health, economic, and water conservation scenarios, whose output is probabilistic in nature. The three model components are described, with particular emphasis on the model linkages and the water sub‐component, and results are shown for a variety of scenarios.