Sharif Digital Repository

Time of concentration (TC) of surface flow in watersheds depends on the coupled response of hillslopes and stream networks. The important point in this background is to study the effects of the geometry and the shape of complex hillslopes on the time of concentration considering the degree of flow convergence (convergent, parallel or divergent) as well as the profile curvature (concave, straight or convex). In this research, the shape factor of complex hillslopes as introduced by Agnese et al. (2007) is generalized and linked to the TC. A new model for calculating TC of complex hillslopes is presented, which depends on the plan shape, the type and degree of profile curvature, the Manning... 

The travel time of subsurface flow in complex hillslopes (hillslopes with different plan shape and profile curvature) is an important parameter in predicting the subsurface flow in catchments. This time depends on the hillslopes geometry (plan shape and profile curvature), soil properties and climate conditions. The saturation capacity of hillslopes affect the travel time of subsurface flow. The saturation capacity, and subsurface travel time of compound hillslopes depend on parameters such as soil depth, porosity, soil hydraulic conductivity, plan shape (convergent, parallel or divergent), hillslope length, profile curvature (concave, straight or convex) and recharge rate to the groundwater... 

In the present study, we aimed to quantify the effects of COVID-19 restrictions and speech treatment approaches during lockdowns on autistic children using CBCL and neuro-fuzzy artificial intelligence method. In this regard, a survey including CBCL questionnaire is prepared using online forms. In total, 87 children with diagnosed Autism spectrum disorders (ASD) participated in the survey. The influences of three treatment approaches of in-person, telehealth and public services along with no-treatment condition during lockdown were the main factors of the investigation. The main output factors were internalized and externalized problems in general and their eight subcategory syndromes. We... 

In this work, the mesoporous magnetic heterogeneous catalyst was synthesized by anchoring copper (II) onto the nitrogen-rich poly (melamine) Schiff base networks magnetic nanocomposite. First, MNP (Fe3O4@SiO2) was functionalized with chlorosilane (CPTS). Then, the chlorine of these functionalized magnetic nanoparticles could react with the –NH2 groups of the melamine through a nucleophilic substitution reaction. Simultaneously, the condensation polymerization of melamine and benzene-1, 3, 5-tricarbaldehyde was carried out in the presence of surface-modified magnetic nanoparticles. Later, Fourier-transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermogravimetric analysis... 

In recent years there has been potential increase in the use of alkaline protease as industrial catalysts. Many major industrial and commercial applications, such as food and textile industries, and medical diagnoses, are highly dependent on the protease enzyme. In the cell immobilization technique, the free movement of microorganisms is restricted in the process, and a continuous system of fermentation can be used. In the present work, this technique has been used for alkaline protease production using different carriers, such as chitosan, corn cob and corn tassel. Enzyme activity before immobilization (72 h) was 78.3 U/ml. Corn cob, with 65% immobilization capacity and the highest enzyme... 

The simultaneous control of the molecular weight, separation, and purification of polyvinyl acetate was achieved using a cobalt-mediated radical polymerization (CMRP) in a packed column with silica gel particles (PC-CMRP). The controlled radical polymerization of VAc in the packed columns was evaluated from the linear time dependence of Ln[M]0/[M], linear increase of molecular weight with the increase in conversion, and narrow molecular weight distribution. PC-CMRP method was used to produce high-purity polymers with controlled molecular weight and narrow molecular weight distribution without requiring additional purification steps. The high ability of silica gel particles to adsorb free...