POPULATION ESTIMATES

In dealing with population estimates, we need to determine first the reason for estimating the population. If we are dealing with a local situation, are we concerned with a local estimate? If we are dealing with a regional problem, are we concerned with a regional estimate? The blackbird problem is chiefly a regional problem, but we need to look at broader horizons than just local or regional situations. Are we dealing with a national problem? Is this problem a year-round one or is it a seasonal problem? We may want to know just purely the number of birds we are dealing with. Another reason for doing population estimates might be to determine the effectiveness of some lethal control method that has been employed. Fortunately, those species with which we are most concerned are those not on the endangered species list at the present time. Many Ohio farmers would like to see the Red-winged Blackbird on the endangered species list, I think, but it is not there. My particular interest in population estimates is to determine if we can develop an early warning system for the agriculturists, so that they can better anticipate the time they can expect damage from birds. A lot of methods have been tried in the past.

Feasibility Study of Solar Driven Underground Cooling System

In the United States the peak electrical use occurs during the summer. In addition, the building sector consumes a major portion of the annual electrical energy consumption. One of the main energy consuming components in the building sector is the Heating, Ventilation, and Air-Conditioning (HVAC) systems. This research studies the feasibility of implementing a solar driven underground cooling system that could contribute to reducing building cooling loads. The developed system consists of an Earth-to-Air Heat Exchanger (EAHE) coupled with a solar chimney that provides a natural cool draft to the test facility building at the Solar Energy Research Test Facility in Omaha, Nebraska. Two sets of tests have been conducted: a natural passively driven airflow test and a forced fan assisted airflow test. The resulting data of the tests has been analyzed to study the thermal performance of the implemented system. Results show that: The underground soil proved to be a good heat sink at a depth of 9.5ft, where its temperature fluctuates yearly in the range of (46.5°F-58.2°F). Furthermore, the coupled system during the natural airflow modes can provide good thermal comfort conditions that comply with ASHRAE standard 55-2004. It provided 0.63 tons of cooling, which almost covered the building design cooling load (0.8 tons, extreme condition). On the other hand, although the coupled system during the forced airflow mode could not comply with ASHRAE standard 55-2004, it provided 1.27 tons of cooling which is even more than the building load requirements. Moreover, the underground soil experienced thermal saturation during the forced airflow mode due to the oversized fan, which extracted much more airflow than the EAHE ability for heat dissipation and the underground soil for heat absorption. In conclusion, the coupled system proved to be a feasible cooling system, which could be further improved with a few design recommendations.