A case definition for post-viral fatigue syndrome is proposed within which various subgroups of patients exist. Any one treatment may not apply to all the subgroups. In particular, patients' experiences do not show that avoidance of exercise is maladaptive. It is proposed that the recently ill often try to exercise to fitness whereas the chronically ill have learnt to avoid exercise. Recovery i...

Atmospheric aerosols and particulate matter from a wide variety of emissions sources measurements are conventionally performed by recording PM mass. The ambient standards are written in terms of mass concentrations, and emission regulations are based on mass rates. However, in order to understand better the nature of the mobile source contribution to ambient PM, many research groups are current...

BACKGROUND Diesel exhaust exposure may cause acute irritant-induced asthma and potentiate allergen-induced asthma. There are no previous reports of occupational asthma due to diesel exhaust. AIMS To describe occupational asthma with latency in workers exposed to diesel exhaust in bus garages. METHODS The Shield database of occupational asthma notifications in the West Midlands, UK, was sear...

Traffic-related sources have been recognized as a significant contributor of particulate matter particularly within major cities. Exhaust and non-exhaust traffic-related sources are estimated to contribute almost equally to traffic-related PM10 emissions. Non-exhaust particles can be generated either from non-exhaust sources such as brake, tyre, clutch and road surface wear or already exist in ...

Motor vehicles are major sources of gas-phase organic carbon, which includes volatile organic compounds (VOCs) and other compounds with lower vapor pressures. These emissions react in the atmosphere, leading to the formation of ozone and secondary organic aerosol (SOA). With more chemical detail than previous studies, we report emission factors for over 230 compounds from gasoline and diesel ve...

Of primary concern with the integration of Hall thrusters on conventional satellite designs is the possible damaging effect of high-energy exhaust ions impinging upon spacecraft surfaces. This paper reports on measurements of plasma ion-energy distributions within the plume of an SPT-100 Hall thruster using a custom-designed molecular beam mass spectrometer. With this instrument ion energy was ...

Message transmission in opportunistic networks is accomplished via the encounters of mobile nodes while moving around. The distributing of nodes greatly impacts the performance of message delivery ratio due to their sparse encounter opportunities. Nodes with exhaust energy can’t participate in message transfer process. So it is very meaningful to make nodes energetic and balance the energy cons...

Of primary concern with the integration of Hall thrusters on conventional satellite designs is the possible damaging effect of high-energy exhaust ions impinging upon spacecraft surfaces. This paper reports on measurements of plasma ion energy distributions within the plume of an SPT-100 Hall thruster using a custom-designed molecular beam mass spectrometer. With this instrument ion energy was ...

This study presents comparative energy and exergy analyses of a single cylinder, four stroke Ruston diesel engine. The test was conducted by varying the load between zero and maximum while keeping the engine speed constant. Then, using the steady-state data along with energy and exergy balance equations, various performance parameters of the engine were measured. From the study it was found tha...

The hot gases produced by the internal combustion engines passes through the exhaust valve and causes high temperatures in the exhaust valve and its seat. To avoid damaging the exhaust valve, heat must be transferred from the valve to its seat during the contact they make at the opening and closing cycle. Heat transfer rate from the exhaust valve to its seat is a function of many factors. One o...