predicting the maintenance and management costs and replacement age of tractors in agricultural mechanized units, is important from several points. so, doing a timely agricultural operations, more accurate measure of the amount of income  including the cost of these items , determining the useful life of old tractors , replacement age, cost of the process changes and the possibility of examinin...

this paper presents mathematical models of thin layer forced convection solar drying of cuminum cyminum using two drying methods (mixed and indirect) at different operating conditions. the average initial moisture content of the seeds for all tests was about 43% d.b. and the drying was performed continuously, in each test, for a uniform period of 90 minutes drying time in a solar cabinet dryer ...

the aim of this research is to simulate oil spill behavior in the persian gulf due to the wind andtidal currents. this is achieved by coding an oil spill mathematical model consisting of several major submodels including hydrodynamic model, oil slick dynamic model and oil weathering model. the base of all of them is eulerian approach and they are coupled together to simulate spill incident in t...

this paper mainly focuses the study and analysis of the existing contributions related to the biodiesel production. it, firstly, discuss the key issues related contributions which include chemical process, reactor designing, plantation, blending and applications. next, it summarizes the analysis of the other prominent contributions related to process model, design, production, cost, optimizatio...

gene transfer to plants and the production of transgenic plants with various purposes, such as improving the performance and quality, resistance to pests, diseases, etc., and of great importance are carried out gene transfer to plants performs to evaluate the transient and permanent gene expression. transient expression is quick, easy and simple and is not influenced by position effect compare ...

abstract in recent years, many researchers have attempted to estimate the soil hydraulic functions (e.g. soil moisture characteristics curve, and hydraulic conductivity function) using particle-size distribution (psd) curve. in these studies, an accurate mathematical representation of psd is required for fitting the observed data. so far, some mathematical models were developed with different l...

We study the history and recent developments in nonelementarymodel theory focusing on the framework of abstractelementary classes. We discuss the role of syntax and semanticsand the motivation to generalize first order model theory to nonelementaryframeworks and illuminate the study with concrete examplesof classes of models. This first part introduces the main conceps and philosophies anddiscu...

We study the history and recent developments in nonelementarymodel theory focusing on the framework of abstractelementary classes. We discuss the role of syntax and semanticsand the motivation to generalize first order model theory to nonelementaryframeworks and illuminate the study with concrete examplesof classes of models. This second part continues to study the question of catecoricitytrans...