Design study: A 186 kW lightweight diesel aircraft engine

The design of an aircraft engine capable of developing 186 kW shaft power at a 7620 m altitude is described. The 186 kW design takes into account expected new developments in aircraft designs resulting in a reassessment of the power requirements at the cruise mode operation. Based on the results of this analysis a three phase technology development program is projected resulting in production dates of 1985, 1992, and 2000

Social stigma is an underestimated contributing factor to unemployment in people with mental illness or mental health issues:Position paper and future directions

Background As yet, little is known about the effects of mental health stigma on sustainable employment. This is surprising, as mental health stigma is common, and because people with severe and common mental disorders are 7 and 3 times more likely to be unemployed, respectively, than people with no disorders. As the global lifetime prevalence of mental disorders is 29%, the high unemployment rates of people with these health problems constitute an important and urgent public health inequality problem that needs to be addressed. Main text The aim of this position paper is to illustrate the assumption that stigma contributes to the unemployment of people with mental illness and mental health issues with evidence from recent scientific studies on four problem areas, and to provide directions for future research. These four problem areas indicate that: (1) employers and line managers hold negative attitudes towards people with mental illness or mental health issues, which decreases the chances of people with these health problems being hired or supported; (2) both the disclosure and non-disclosure of mental illness or mental health issues can lead to job loss; (3) anticipated discrimination, self-stigma and the ‘Why Try’ effect can lead to insufficient motivation and effort to keep or find employment and can result in unemployment; and (4) stigma is a barrier to seeking healthcare, which can lead to untreated and worsened health conditions and subsequently to adverse occupational outcomes (e.g. sick leave, job loss). Conclusions The paper concludes that stigma in the work context is a considerable and complex problem, and that there is an important knowledge gap especially regarding the long-term effects of stigma on unemployment. To prevent and decrease adverse occupational outcomes in people with mental illness or mental health issues there is an urgent need for high quality and longitudinal research on stigma related consequences for employment. In addition, more validated measures specifically for the employment setting, as well as destigmatizing intervention studies are needed

Lightweight diesel engine designs for commuter type aircraft

Conceptual designs and performance of advanced technology lightweight diesel engines, suitable for commuter type aircraft power plants are defined. Two engines are discussed, a 1491 kW (2000 SHP) eight-cylinder engine and a 895 kW (1200 SHP) six-cylinder engine. High performance and related advanced technologies are proposed such as insulated cylinders, very high injection pressures and high compressor and turbine efficiencies. The description of each engine includes concept drawings, a performance analysis, and weight data. Fuel flow data are given for full and partial power up to 7620m altitude. The performance data are also extrapolated over a power range from 671 kW(900SHP) to 1864 kW (2500 SHP). The specific fuel consumption of the 1491 kW (2000 SHP) engine is 182 g/hWh (.299 lb/HPh) at cruise altitude, its weight 620 kg (1365 lb.) and specific weight .415 kg/kW (.683 lb/HP). The specific fuel consumption of the 895 kW (1200 SHP) engine is 187 g/hWh (.308 lb/HPh) at cruise altitude, its weight 465 kg (1025 lb.) and specific weight .520 kg/kW (.854 lb/HP)

A 150 and 300 kW lightweight diesel aircraft engine design study

The diesel engine was reinvestigated as an aircraft powerplant through design study conducted to arrive at engine configurations and applicable advanced technologies. Two engines are discussed, a 300 kW six-cylinder engine for twin engine general aviation aircraft and a 150 kW four-cylinder engine for single engine aircraft. Descriptions of each engine include concept drawings, a performance analysis, stress and weight data, and a cost study. This information was used to develop two airplane concepts, a six-place twin and a four-place single engine aircraft. The aircraft study consists of installation drawings, computer generated performance data, aircraft operating costs, and drawings of the resulting airplanes. The performance data show a vast improvement over current gasoline-powered aircraft

Effect of PCE-type superplasticizer on early-age behaviour of ultra-high performance concrete (UHPC)

The effect of PCE-type SP on zeta potential of particles, spread flow, hydration kinetics, setting time, autogenous shrinkage and chemical shrinkage of UHPC pastes is investigated, as well as the spread flow, slump life and early-age strength development of UHPC. Furthermore, the dispersing and fluid-retaining ability of SP, retardation effect of SP, physical and chemical process effects are analysed. The results show that the dispersing ability of PCE-type SP is determined by its chemical structure, which shows an exponential relationship between the flowability of pastes and SP dosages. The fluid-retaining abilities of UHPCs are sensitive to the water-to-powder ratio, while the further addition of SP will not enhance the slump life after excessing the saturation dosage. Both the adsorbed PCE and the PCE remaining in the aqueous phase contribute to retardation effect. A linear correlation between the final setting time (t final) and the time of maximum heat flow rate (t Q¨=max) is derived. The types and dosages of SP primarily influence the absolute chemical shrinkage of pastes within 1 day, but have a great effect on the autogenous shrinkage due to different physical coagulation and chemical process. </p

Thermal treatment on MSWI bottom ash fines

The municipal solid waste incineration (MSWI) bottom ash is the main by-product in the waste-to-energy plant, which accounts for about 80% of the total by-products. The further challenge after incineration is to find a suitable way to dispose or use the solid residue. It is well understood that the bottom ash contains contaminants, such as heavy metals, which pose an environmental risk. In order to reduce landfill of these residues and enhance the recycling of resources, different treatments are applied to upgrade the quality of the bottom ash, for instance, weathering, washing, etc. However, the treatments on the MSWI fine bottom ash particles are less sufficient. Hence, in this study the thermal treatment is applied on fine bottom ash and its effect on the bottom ash properties are investigated

Thermal treatment on MSWI bottom ash fines

The municipal solid waste incineration (MSWI) bottom ash is the main by-product in the waste-to-energy plant, which accounts for about 80% of the total by-products. The further challenge after incineration is to find a suitable way to dispose or use the solid residue. It is well understood that the bottom ash contains contaminants, such as heavy metals, which pose an environmental risk. In order to reduce landfill of these residues and enhance the recycling of resources, different treatments are applied to upgrade the quality of the bottom ash, for instance, weathering, washing, etc. However, the treatments on the MSWI fine bottom ash particles are less sufficient. Hence, in this study the thermal treatment is applied on fine bottom ash and its effect on the bottom ash properties are investigated

The investigation of the MSWI bottom ash fines (0-2 mm) as binder substitute after combined treatments

In this study, a series of treatments is used to upgrade the quality of the MSWI bottom ash fines (0-2 mm) from a waste-to-energy plant in the Netherlands. The efficiency of combined treatments on upgrading the quality of fine bottom ash particles to be used as cementitious material is studied. The leaching properties of treated bottom ash fines are analyzed according to the Dutch legislation. Additionally, their physical and chemical properties (density, chemical composition, hydration influence, etc.) are characterized. Finally, the hydration of the cement mixed with treated bottom ash is investigated by calorimetric measurements