The analytical investigations of the filtering efficiency with multi-layered stainless screen filter, which is designed to generate swirling stream of micro metal dust from industrial manufacturing processes, were conducted. Compared to general filter dust collecting using bag filter, it can be expected that the metallic screen filters in this study enable the higher dust collecting efficiency of a system to be maintained even under harsh filtering conditions. The CFD analysis includes dust particles behavior, filtering efficiency, and pressure loss in the flow-field. The results show that the proposed 16 layered screen filter is able to collect 10 microns metal dust up to 97 % under 487.84 ㎩ differential pressure.

We used the three kinds of mosquito traps (Black-hole with UV light, CO2-baited Mos-hole with the newly developed attracting-solvent, CO2-baited DMS; Digital Mosquito Monitoring System) to know their collecting efficiency for the female mosquitoes in Korean rural areas. The Black-hole mosquito trap caught many kinds of insects including only few female mosquitoes. The Black-hole trap has the UV-light and the light seemed to attract other terrestrial and aquatic insects, such as the common flies, May flies, and the stone flies. Even though the trap was developed to collect mosquitoes, the trap caught only few of female mosquitoes less than 1% of all insects caught. Their selective efficiency to collect the female mosquitoes was relatively lower than other two kinds of traps. The Mos-hole and CO2-baited DMS traps had the collecting efficiency of over 80% to collect the female mosquitoes. The two traps caught the relatively lower number (less than 3% of total insects) of other insects, such as few Coleoptera and Diptera, and their collecting efficiency for the female mosquitoes was very higher. Generally speaking, mosquitoes disliked the UV light but they relatively preferred CO2 gas including the attracting-solvent. They had also been attracted the acidic solvent with CO2 gas. If we could use the efficient and selective mosquito traps with the fully understanding about the mosquito habits, we could assume that we can keep the biodiversity high around the mosquito habitats as well as to save money for the insect pest control.