Crop production process utilizes input energy and produces some biomass energy as output.  During this process, greenhouse gases (GHGs) are also emitted which can make environmental risks. In this study, input and output energies, energy indices, and GHG emissions arising from inputs were estimated for wheat-cotton rotation under different tillage practices in Fars province. The study was condu...

medical linear accelerators are one of the most widespread methods for cancer treatment. despite their advantages, unwanted photoneutrons are produced by high energy linacs. this photoneutrons are as undesired doses to patients and a significant problem for radiation protection of the staffs and patients. photoneutrons radiological risk must be evaluated because of their high let and range.in o...

in order to perform each component of agricultural practices, its plan should be rationalized economically and technically. in a study for recognition patterns of energy inputs and outputs in saffron fields of southern khorasan, iran, during a five years exploitation period, two questionnaires were prepared, one for the first cultivation year, and another for crop management and harvest during ...

A method for solving the descriptor discrete-time linear system is focused. For easily, it is converted to a standard discrete-time linear system by the definition of a derivative state feedback. Then partial eigenvalue assignment is used for obtaining state feedback and solving the standard system. In partial eigenvalue assignment, just a part of the open loop spectrum of the standard linear s...

Cognitive radio (CR) technology has been suggested for effective use of spectral resources. Spectrum sensing is one of the main operations of CR users to identify the vacant frequency bands. Cooperative spectrum sensing (CSS) is used to increase the performance of CR networks by providing spatial diversity. The accuracy of spectrum sensing is the most important challenge in the CSS process sinc...

We study the energy spectrum of bottomonium in perturbative QCD, taking α s (M Z) = 0.1181 ± 0.0020 as input and fixing m MS b (m MS b) on the Υ(1S) mass. Contrary to wide beliefs, perturbative QCD reproduces reasonably well the gross structure of the spectrum as long as the coupling constant remains smaller than one. We perform a detailed analysis and discuss the size of non-perturbative effec...

iran is one of the most energy-rich countries subsidizing energy carriers, especially in the agricultural sector, to the extent that the resulting growth is at the expense of the environment. this study tries to investigate the potential impacts of energy price reform on the agro-environment, based on the marginal abatement costs (macs) of emissions. firstly, the energy demand function of the a...

Nonlinear dynamic analyses are performed to compute the maximum relative input energy per unit mass for 21 multi-degree-of-freedom systems (MDOF) with preselected target fundamental periods of vibration ranging from 0.2 to 4.0 s and 6 target inter-story ductility demands of 1, 2, 3, 4, 6, 8 subjected to 40 the earthquake ground motions. The efficiency of the several intensity measures as an ind...