This paper investigates the effect of separated exhaust expansion chamber parameters on pressure oscillations in spark-ignited internal combustion (IC) gasoline engines. It is known that exhaust expansion chambers are becoming increasingly more popular among both – original equipment (OE) and aftermarket equipment (AE) exhaust system manufacturers for performance-oriented motorcycles equipped with mainly single cylinder engines, but the companies are reluctant to reveal any detailed principles of operation of the mentioned expansion chambers. The subject of this research is the type of expansion chamber (separate) as used on performance-oriented motorcycles, particularly its’ effect on exhaust pressure pulsations as different chamber volumes, locations and passage sizes are tested. Time-dependent computational fluid dynamics (CFD) analysis was carried out in Solidworks Flow Simulation environment on a simplified exhaust header pipe model imitating engine operation at full load and steady speed. Honda CRF450R motorcycle engine was used as the example and fully defined using a 1D engine performance calculator software to determine the combustion chamber pressure and exhaust valve lift at any given crankshaft position. Volume flow rate of exhaust gasses at the header pipe inlet was calculated based on engine parameters and operating speed. The average pressure values with respect to physical time were measured and graphed across the header pipe inlet cross-section. Eight different header pipe and exhaust expansion chamber combinations were modelled, tested, and results compared at low, medium and high engine speeds. It was found that the presence of exhaust expansion chamber tends to dampen the amplitude and decrease the frequency of pressure oscillations generated at the opening of the exhaust valve(s). Observations show that the addition of an expansion chamber as per design of performance-oriented motorcycles helps to decrease the negative effect of engine tuning while also dampening the positive effect.

Remote and automatic monitoring of two Apis Cerana bee colonies was conducted in Indonesia to demonstrate precision beekeeping approach in that region. Successful implementation of the precision beekeeping system includes development of the bee colony monitoring hardware and software for data collection, analysis and visualisation. This paper focuses on development and installation of such systems at the private apiary in Indonesia. For bee colony monitoring at the apiary a developed monitoring unit was used, which is based on ESP microchip, and for the data storage SAMS data warehouse was used. The monitoring results showed that the choice of the location of the temperature sensor is important, as the temperature at the hive sides changes synchronously with the outside temperature. Also, feedback from the beekeeper is collected to further improve the system and monitoring process. This research is conducted within the SAMS – Smart Apiculture Management Services project, which is funded by the European Union within the H2020-ICT-39-2016-2017 call and with close collaboration with the local private beekeeper. To find out more, visit the project website https://sams-project.eu/.