-This paper introduces an uncertainty model for the quantitatively estimate precipitation using weather radars. The model considers various key aspects associated to radar calibration, attenuation, and the tradeoff between accuracy and radar coverage. An S-band-radar case study is presented to illustrate particular fractional-uncertainty calculations obtained to adjust various typical radar-calibration elements such as antenna, transmitter, receiver, and some other general elements included in the radar equation. This paper is based in "Guide to the expression of Uncertainty in measurement" [1] and the results show that the fractional uncertainty calculated by the model was 40 % for the reflectivity and 30% for the precipitation using the Marshall Palmer Z-R relationship.

This article shows the results of the analysis performed to the Liquefied Petroleum Gas (LPG) sector, covering aspects related to its production and consumption, initially addressing the international scenario with countries such as Spain, Brazil, China, India and Ghana, to later make the analysis of the national scenario with a look at the participation of the sector within the energy matrix. Finally, a comparison of the international scenario with the national reality is made, concluding that the contribution of the sector to the economy of the country is quite small, it is not competitive despite having favorable environmental characteristics, making urgent its intervention in order to take it to be competitive within the basket of liquid fuels, in such a way that it becomes a viable alternative energy and is established from a public policy sector structure, allowing supply a market and meet social and economic needs.