Solubilization of sewage sludge creates favorable conditions for anaerobic microorganisms to produce biogas. In this paper, we quantify the effect of heating pretreatment on the degree of solubilization of sewage sludge. The pretreatment process was carried out using a lab-scale industrial microwave unit (2450 MHz frequency). Response surface analysis was applied to determine the combination of...

Unlimited access to a motorway network can, in overloaded conditions, cause a loss of capacity. Ramp metering (signals on slip roads to control access to the motorway) can help avoid this loss of capacity. The design of ramp metering strategies has several features in common with the design of access control mechanisms in communication networks. Inspired by models and rate control mechanisms de...

This paper aims to evaluate and compare the effects of different methods of ramp metering on the operational conditions of traffic flow at three levels: the network level (including the freeway and its connected ramps), the entrance ramp, and the upstream segment of the entrance. To achieve this aim, one of the most important urban freeways in the metropolis of Isfahan was selected. The traffic...

Measurements of oxygen deficit during submaximal exercise were correlated with the anaerobic threshold (as measured by gas exchange analysis), peak work rate on a ramp protocol, and the ability to perform constant work rate exercise in 10 male patients with New York Heart Association class 2 congestive heart failure and 12 age- and gender-matched normal controls. All subjects performed a maxima...

OBJECTIVES This study tested the hypotheses that (1) secondary criteria (respiratory exchange ratio (RER), heart rate, blood [lactate]) traditionally used to verify the determination of maximum oxygen uptake (VO₂(max)) in children can result in the acceptance of a 'submaximal' VO₂(max) or falsely reject a 'true' VO(₂max) and (2) the VO₂(peak) recorded during a ramp test in children is comparabl...

Constant ramp strength tests on unidirectional thermoplastic composite specimens oriented in the 90° direction were conducted at constant temperatures ranging from 149°C to 232°C. Ramp rates spanning 5 orders of magnitude were tested so that failures occurred in the range from 0.5 sec. to 24 hrs. (0.5 to 100,000 MPa/sec). Below 204°C, time-temperature superposition held allowing strength at lon...

This paper presents a biogeography-based optimization (BBO) algorithm to solve the economic loadDispatch (ELD) problem with generator constraints in thermal plants. The applied method can solvethe ELD problem with constraints like transmission losses, ramp rate limits, and prohibited operatingzones. Biogeography is the science of the geographical distribution of biological species. The modelsof...

The fundamental objective of economic load dispatch is to operate the available generating units such that needed demand satisfies lowest generation cost and also complies with various constraints. With proper power system operation planning using optimized limits, it possible reduce generation. To fulfill needs objectives, can help plan electrical system. optimize problems, classical new evolu...