Search results

Radiometric calibration is a method that estimates the reflection of the target from the measured input radiation. The purpose of this study is to radiometrically calibrate three spectral bands of Sentinel-2A, including green, red and infrared. For this purpose, Landsat-8 OLI data are used. Because they have bands with the same wavelength range and they have the same structure. As a result, Landsat-8 OLI is appropriate for relative radiometric calibration.

The method used in this study is radiometric calibration uncorrected data from a sensor with corrected data from another sensor. Also, another aim of this study is a comparison between radiometric correction data and data that, in addition to radiometric correction, has been sharpened with panchromatic data. In this method, both of them have been used for radiometric calibration. Calibration coefficients have been obtained using the first-order polynomial equation.

This study showed that the corrected data has more valid answers than corrected and sharpened data. This method studied three land-cover types, including soil, water and vegetation, which it obtained the most accurate coefficients of calibration for soil class because R-square in all three bands was above 88%, and the root mean square error in all three bands was below 0.01. In the case of water and vegetation classes, only results of red and infrared bands were suitable.

For validating this method, the radiometric correction module of SNAP software was used. According to the results, the coefficient of radiometric calibration of the Landsat-8 sensor was very close to the coefficients obtained from the corrected data by SNAP.

The objective of this study was to determine the chemical composition of saffron's pollen.

A 30 kg sample of saffron (Crocus sativus L.) was collected at the end of November from a farm in a village in the suburb of Gonabad, in Khorasan Razavi, in Iran. Then the pollens were separated from the flowers and stored at −15°C in airtight containers until the analyze. The proximate composition of the pollen was determined by using standard methods of food analysis. The samples of ash were used for the subsequent determination of potassium, magnesium, sodium, calcium, zinc, iron, copper and manganese by using atomic absorption.

Results showed the chemical composition as follows: moisture (12.50 percent), ash (9.5 percent), crude fiber (7.4 percent), crude fat (5.8 percent), crude protein (23.6 percent) and total carbohydrate (20 percent). Saffron's pollen is a good source of minerals such as potassium (57,460 ppm), magnesium (3,357.5 ppm), sodium (1,100 ppm), calcium (600 ppm), zinc (100.75 ppm), iron (194 ppm), copper (53.2 ppm) and manganese (48.5 ppm).

The composition and nutritional value of saffron's pollen had not been determined before.

Technological entrepreneurship has been a very significant topic in recent decades. It has a crucial role in economic modernization and growth. The need for technological entrepreneurship is because technology-based industries are expanding rapidly and are replacing traditional industries. Therefore, this study aimed at identifying the factors affecting the success of technological entrepreneurship in Iranian nanotechnology businesses.

The research was conducted through mixed method. The participants in the qualitative section included 17 university experts and executive managers in the field of nanotechnology in Iran, and 75 nanotechnology business managers participated in the quantitative section. The interview and questionnaire were used to collect information. In order to measure and fit the models, the confirmatory factor analysis method and PLS3 software were used.

The results indicated that the key factors affecting the success of the technological entrepreneurship process in nanotechnology were classified into five general categories: organizational, environmental, institutional, individual and technology factors. Moreover, it was shown that all these dimensions had a positive and significant effect on technological entrepreneurship. In addition, the organizational dimension has an essential role.

Companies' ability to engage technological entrepreneurship is a vital factor in human resource management and strategic management. However, technological entrepreneurship in Iranian nanotechnology businesses has not been involved integrally in the context of companies.