the main task of drilling the formation by the bit is done via scraping, crushing and grinding. discharging the fluid from the bit nozzles is done with high pressure which assists to break the rocks. different parameters affect the bit selection and design for each drilling formation, but the most important one is drillability that depends on hardness of the formation. in this paper, the design...

The aim of this paper is to introduce a methodology for defining groups from regionalized compositional data, through a hierarchical clustering algorithm aware of both the spatial dependence and the compositional character of the data set. This method is used to define a regionalization of Catalunya (NE Spain) with respect to its precipitation patterns in the Winter season. This region is chara...

Quantifying rainfall at spatial and temporal scales in regions where meteorological stations are scarce is important for agriculture, natural resource management and land-atmosphere interactions science. We describe a new approach to reconstruct daily rainfall from rain gauge data and the normalized difference vegetation index (NDVI) based on the fact that both signals are periodic and proporti...

Recent research has suggested that changes in temperature and precipitation events due to climate change have had a significant impact on the availability and timing of streamflow. In this study, monthly temperature and precipitation data collected over 29 climate divisions covering the entire Colorado River basin and monthly natural flow data from 29 U.S. Geological Survey (USGS) gauge locatio...

Studying precipitation variability in the Peruvian Andes is a challenge given the high topographic variability and the scarcity of weather stations. Yet previous research has shown that a near-linear relationship exists between precipitation and vegetation in the semiarid central Andes. We exploit this relationship by developing a new, spatially highly resolved spatiotemporal precipitation reco...