Overview. Beryllium is the lightest member of the alkaline earth metals family. These metals make up Group 2 (IIA) of the periodic table. They include beryllium, magnesium, calcium, strontium, barium, and radium.Elements in the same column of the periodic table have similar chemical properties.eryllium is the lightest member of the alkaline earth metals family. These metals make up Group 2 (IIA) of the periodic table.
Definition 1: EER, energy efficiency ratio: Is the measure of air conditioner efficiency at maximum air conditioning load. It is measured by ratio of Btu/hour of cooling or heating load, to watts of electrical power input. The unit is in Btu hr-1 W-1. Definition 2: SEER, seasonal energy efficiency ratio: The measurement units of SEER is exactly the same as EER, but the difference lies in the data used for the measurement. Values for SEER, is determined through averaging readings of different air conditions, to represent air conditioner efficiency throughout the season.
internal rate of return (IRR) One of the two discounted cash flow (DCF) techniques (the other is net present value or NPV) used in comparative appraisal of investment proposals where the flow of income varies over time. IRR is the average annual return earned through the life of an investment and is computed in several ways. Depending on the method used, it can either be the effective rate of interest on a deposit or loan, or the discount rate that reduces to zero the net present value of a stream of income inflows and outflows.