Salim Bawazir

Estimating Solar Radiation from Temperature with Spatial and Temporal Calibration

A procedure is introduced to estimate daily solar radiation from maximum and minimum temperatures for areas where solar radiation is either unavailable or unreliable. The procedure uses historical temperature data for spatial and temporal self-calibration. The results from the self-calibrated procedure are compared with measured solar radiation data in one coastal and two interior regions. The self-calibrated procedure is also compared with an equation presented by Thornton and Running that also uses historical maximum and minimum temperature to estimate solar radiation. The comparison between measured and predicted solar radiation values for several years shows that the self-calibrated method can predict solar radiation with error ranging from 0–3%. The error from the Thornton and Running equation ranges from 7–11%. In general, the Thornton and Running equation tends to overestimate solar radiation especially for overcast sky conditions such as monsoon season.

Remote sensing used to detect moisture status of pecan orchards grown in a desert environment

Remote-sensing techniques can detect and up-scale leaf-level physiological responses to large areas, and provide significant and reliable information on water use and irrigation management. The objectives of this study were to screen leaf-level physiological changes that occur during the cyclic irrigation of pecan orchards to determine which responses best represent changes in moisture status of plants and link plant physiological changes to remotely sensed surface reflectance data derived from the Landsat Thematic Mapper and Enhanced Thematic Mapper Plus (ETM+). The study was conducted simultaneously on two southern New Mexico mature pecan orchards. For both orchards, plant physiological responses and remotely sensed surface reflectance data were collected from trees that were either well watered or in water deficit. Remotely sensed variables included reflectance in band 1, the ratio between shortwave infrared (SWIR) bands (B5:B7), the normalized difference vegetation index, and SWIR moisture indices. Midday stem water potential (Ψsmd) was the best performing leaf-level physiological response variable for detecting moisture status in pecans. The B5:B7 ratio positively and significantly correlated with Ψsmd in five of six irrigation cycles while multiple linear regression weighted with six remotely sensed surface reflectance variables revealed a significant relationship with moisture status in all cycles in both orchards (R2 > 0.73). Because changes in the B5:B7 band ratio and multiple regression of spectral variables correlate with the moisture status of pecan orchards, we conclude that remotely sensed data hold promise for detecting the moisture status of pecans.

Teaching introductory fluids through fountain design

Neophyte engineering students have difficulty conceptualizing fluid concepts, and have little understanding of the design process. The fountain concept development, prototyping, design, and fountain building process allows students to experience the iterative nature of design while they developed an intuitive basis for learning and remembering fluids fundamentals. The students were divided into teams and given a budget of

A simple irrigation scheduling approach for pecans

20/team. The final report included concept development, fountain features, design approach, materials list, budget, engineering drawings, and design calculations. The students gave the project a very positive review, resulting in the civil engineering (CE) and engineering technology (ET) introductory fluids classes using the project during the spring semester 2003.