A new passive solar water pasteurization system based on density difference flow principles has been designed, built and tested. The system contains no valves and regulates flow based on the density difference between two columns of water. The new system eliminates boiling problems encountered in previous designs. Boiling is undesirable because it may contaminate treated water. The system with ...

the objective of this study was to investigate dehydration kinetics of barberry (berberis vulgaris l.) at different drying temperatures (60 ºc, 70 ºc, 80 ºc), air velocities (0.3 m s-1, 0.5 m s-1, 1 m s-1) with two types of pretreatment. drying time and colour quality during dehydration were experimentally determined. barberries were dried from the initial moisture content of 73.44% (w.b.) to t...

In this report, experimental investigation of waste water treatment by reverse osmosis to enable its reuse in cooling tower is presented. A polyamide spiral wound RO membrane followed by three filters as RO pretreatment (two activated carbon and one cartridge filter) and samples of Tehran refinery treated waste water have been used. The effect of operating conditions such as pressure difference...

New and improved methods are needed to disinfect pathogens in treated wastewater, especially highly resistant ones like Cryptosporidium parvum oocysts. In addition, new and improved methods are needed to detect pathogens and indicators for them in wastewater in order to monitor the efficacy of disinfection and other waste water treatment processes. Spores of the anaerobic bacterium Clostridium ...

Bloodfed female Aedes aegypti were exposed to a surface treated with pyriproxyfen at 1.0 g m2 for 30 min and then allowed to lay eggs in cups of water containing 4th-instar larvae. Adult emergence from the immatures was highly inhibited, and transmission of pyriproxyfen from the females to the water was revealed. The transfer of the chemical to the water decreased with time before the blood mea...

Occurrence nets (ONs) are acyclic Petri nets recording single system executions. Structured occurrence nets (SONs), composed of multiple ONs together with additional relationships, are intended for portraying the behaviour of complex evolving systems. Such systems generally consist of a large number of sub-systems which may proceed concurrently and interact with each other. In this paper, we de...

BACKGROUND: Pregnant women are a major risk group for malaria in endemic areas. Only little information exists on the compliance of pregnant women with malaria and anaemia preventive drug regimens in the rural areas of sub-Saharan Africa (SSA). In this study, we collected information on malaria and anaemia prevention behaviour in pregnant women of rural Burkina Faso. METHODS: Cross-sectional qu...

Several high-level extensions have been introduced for Petri nets (PNs). Coloured Petri nets (CPNs) are the most famous high-level extensions of PNs. Stochastic activity networks (SANs) are a stochastic generalization of PNs. These models have widely been used for dependability and performability evaluation purposes and are supported with a few powerful modeling tools. To provide some high-leve...