Research of the Indoor Air Quality of New Decoration Residence in Tianjin
With the level of life raised in China, the indoor air quality has aroused people's concern. In order to learn the actuality of air pollution in new decoration residence and improve indoor air quality and provide the foundation that constructs countermeasure of controlling indoor air pollution, the field measurements about indoor air pollution of new decoration residence are made in Tianjin. Basing on type of residences, hours of decoration, distinct development business and decoration corporations selected, the status of indoor air contaminants are analyzed, and the major factors effecting on indoor tiny contaminants concentration are researched. Indoor air contaminants mainly come from the residential decoration and building material and various furnishings and the major contaminants is formaldehyde. Temperature and humidity have great effect on tiny contaminants concentration and the sorts of contaminant¿and influencing degree on human of different tiny contaminants are different. The emitting velocity of contaminants in the same material is alterative under the condition of temperature and humidity being changed. The time of residential decoration is also one important element of contaminants concentration. There are many factors influencing the indoor air quality of new decoration residence. To improve the indoor air quality, we can open the windows to make the fresh outdoor air into room. But if the outdoor air is not clean enough, we should place air purification equipment in room.
Design and prototype implementation of indoor air quality monitoring using LonWorks technology
Environmental Protection Agency (EPA) shows indoor air is 2-3 times more polluted than the worst outside air. These pollutants also lead to simple asphyxiation as general health hazard which ensures the importance of indoor air quality (IAQ) monitoring. Therefore maintaining a good indoor air quality improves the health zone of the peoples both in urban and rural areas. Peoples in rural areas are more affected because burning woods and papers are common practices occurring since there is no much awareness about indoor pollution. Studying about indoor air pollutants is important in order to know about the health hazards caused, exposure limits and sources of the pollutants in the living place which makes a right path way to know about the presence and absence of particular pollutant. The proposed system comprises of low cost sintered metal oxide gas sensor which are general air contaminant sensors. These sensors can sense gas concentrations in ppm level which makes it suitable for the indoor air quality monitoring. Testing of the sensors is been carried out in microcontroller to study their real time characteristics. Later sensors are connected to the LonWorks module. LonWorks technology is a cost effective protocol for building automation system. This communication protocol ensures reliable and energy efficient solution to building automation system.
Lake Muzahi, Rwanda: limnological features and phytoplankton production
Lake Muhazi, a small lake of Rwanda (East Africa) was studied from 1986 to 1990. A dramatic decrease of the catch of Oreochromis niloticus (350 T y−1 in the fifties vs 30 T y−1 in 1982) suggested a loss of productivity or overfishing. In the same period, other ecological changes occurred: the submerged macrophytes regressed and there was a decrease in Secchi depth (0.65 m in 1987 vs 1.5 m in the fifties). Compared to other lakes of the same area, the plankton production seemed low. The results of the present study characterize lake Muhazi as a shallow lake with a rather unstable diurnal stratification and with slight differences in mixing regime between its eastern, deepest part and its western, shallowest part. Secchi disk depth does not vary seasonally to a large extent. The water has a rather high mineral content (conductivity of about 500 µS cm−1 at 25 °C) and low concentrations of dissolved N and P, except in the hypolimnion, where NHinf4sup+-N can be high.Two species, Microcystis aeruginosa and Ceratium hirundinella, account for most of the phytoplankton biomass, which is about 50–80 mg chlorophyll a m−2 in the euphotic zone, usually with little seasonal variation. Daily gross production estimates amount to about 6 to 9.5 g O2 m−2 d−1 with a significant difference between the two parts of the lake. Data on C:N and C:P ratio in the phytoplankton suggest that some N deficiency might occur in the eastern part. Moreover, the Zm:Zc ratio could also lead to rather low net production rates (0.21–0.25 d−1 for a mixed layer of 4 m)In conclusion, the primary production of lake Muhazi is medium for African lakes and the hypothesis that decreased planktonic production could account for a reduced fish production should be discarded. Whereas the present yield of the fishery is only 20 kg ha−1 y−1, the yield estimated from primary production ranges between 46 and 64 kg ha−1 y−1. This could be reached through proper management. Finally, some hypotheses are given to explain the ecological changes which occurred in the lake.