Remote Sensing
Tayebe Managhebi; Mohammadreza Mobasheri
Abstract
The leaf water content is a specific index for the assessment of the physiological status of the plant based on the water content of the vegetation. This research provides an appropriate model based on the reflectance spectra between 400 and 2500 nm to estimate the leaf water content. We examined 53 ...
Read More
The leaf water content is a specific index for the assessment of the physiological status of the plant based on the water content of the vegetation. This research provides an appropriate model based on the reflectance spectra between 400 and 2500 nm to estimate the leaf water content. We examined 53 different species of the well-known Leaf Optical Properties Experiment and a total of 263 spectral curves were employed in a supervised modelling procedure. for this purpose, three different linear models were proposed based on the two different indices and their combination. The first index refers to the ratio of reflectance value in two wavelengths and the second one is the ratio of the derivative of the spectral curve slop in two wavelengths. The experimental results indicate the dependence between the water absorption bands and leaf water content. Finally determination of coefficient for hybrid linear model, which is used both indices, resulted to be 87 percent, indicating a very good fit. Also, the 0.06 relative root mean square error represents the aceptable accuracy in the water content modelling
Propulsion
ALI RASTGAR; Hojat Ghasemi
Abstract
The purpose of this paper is to present experimental data for merging two outlet fluid skirts in a dual pressure- swirl coaxial injector. In this study, a dual pressure- swirl external mixing injector was designed and fabricated. Operational characteristics including discharge coefficient and breakup ...
Read More
The purpose of this paper is to present experimental data for merging two outlet fluid skirts in a dual pressure- swirl coaxial injector. In this study, a dual pressure- swirl external mixing injector was designed and fabricated. Operational characteristics including discharge coefficient and breakup length were expressed in terms of different injection pressures for internal and external injectors. Utilizing fast shooting, based on the backlighting method, the interaction between of two outlet skirts were investigated and the merge performance map was extracted. The merge performance map results indicated, when the pressure difference of the external injector increases from 0.3 bar to 0.95 bar, the pressure difference of the internal injector for the merge to occur increases. The reason for this increase in this range of external injector injection pressure differences is that, the effect of the internal injector injection pressure for merge in this area is greater than the external injector injection pressure, the external injector skirt is pulled toward the internal injector skirt. For injection pressures difference of more than 0.95 bar in the external injector, because the effect of the external injector injection pressure for merge is greater than the internal injector injection pressure, the internal injector injection pressure difference is reduced for the merge to occur and the internal injector skirt is pulled toward the external injector skirt.
