somayeh dehghani

Any collaborative innovation activities cannot be separated from the support of social networks. Many factors in the social network affect the knowledge transfer activities. Moreover, the effectiveness of knowledge transfer determines the performance of collaborative innovation. From the point of view of relevance between collaborative innovation behavior and social network, this paper analyzes the influence of some factors in social network on knowledge transfer of school enterprise synergy innovation. The purpose of this paper is to find out the laws of knowledge transfer in the process of University-Industry (U-I) collaborative innovation, and to verify the role of these laws through system dynamics simulation. Firstly, this paper summarizes the previous views on collaborative innovation and U-I knowledge transfer. Based on the analysis of literature, it puts forward the process model of knowledge transfer in U-I Collaborative Innovation and analyzes the factors that affect this process. Secondly, the paper uses a system dynamics method to analyze the causality of knowledge transfer in the process of U-I collaborative innovation, establishes the model of system flow diagrams, and uses Vensim PLE to test the validation and sensitivity of the model. Furthermore, the experimental results demonstrate that the model could fit well the actual knowledge transfer activities in the process of U-I collaborative innovation. And, the results show that some factors in social networks (trust, knowledge transfer capability, knowledge absorptive capacity, and contract mechanisms) affect U-I knowledge transfer in different degrees. Finally, some suggestions concerning the promotion of knowledge transfer are presented according to the simulation.

Despite the diversity of land use in arid and semi-arid areas of the country, land use can change the soil quality characteristics, as well as soil physical quality. The aim of this study was to investigate the effects of different land use on soil characteristics in the Baghan watershed in the southeast of Bushehr province with an area of about 929 square kilometers. That region has an important role in the production of agricultural products. From the surface soil (0-20 cm) of range, croplands and orchards, 120 composite soil samples were taken. Sampling sites were determined using the Latin hypercube technique. sand (Sa), silt (Si), clay (Cl), bulk density (ρb), porosity (F), air content (AC), effective porosity (Φeff), macro pores (MAP), mean weight (MWD), geometry mean of aggregate diameter (GMD), water aggregate stability (WSA), aggregate stability index (SI), relative water content (RWC), saturated moisture (ΘS), field capacity moisture (FC), permanent wilting point (PWP) and availaible water content (AWC) were determined by conventional methods and fractal dimension (Db) was calculated by mass-diameter method. range, crop land and orchard land uses had significant effect (P <0.01) on all studied characteristics except AC. Mean comparison showed that in range and crop land, among all studied characteristics, only PWP, FC and ΘS were significantly different. In orchard, compared to range, there is a significant increases trend in Sa, F, Φeff, MAP, MWD, GMD, WSA, SI, ،S, FC, PWP, AWC and RWC and a significant decreases trend in Si, Cl , Ρb and Db were observed. Fitting of the linear equation to the measured data showed that with decreasing the clay and silt and increasing the sand, the fractal dimension decreased. The coefficients of explanation of the linear function of the fractal dimension with the percentages of sand, silt and clay were 0.8, 0.55 and 0.82, respectively. Based on the studied characteristics, the most desirable physical quality of soil was observed in orchard land use.

Watersheds are the sources of drinking water for cities and villages, and their pollution with heavy elements threatens the health of the inhabitants who use their water and agricultural products. Considering the importance of Baghan watershed in Bushehr province, the purpose of this study was to evaluate the contamination of soil particle size fractions (<63 and <2000 µm) by some heavy metals (Cd, Mn, Ni, Pb, Zn, Cu, and Fe) in three major land uses (range lands, croplands and orchards). Location of 120 surficial composite soil samples (0-20 cm) were determined using the Latin Hypercube technique on the topographical map. After pretreatment of soil samples, heavy metals were extracted by the Sposito method and measured using an atomic absorption spectrometry and geochemical pollution indicators including contamination factor (CF), geo-accumulation index (Igeo) and the pollution load index (PLI) were calculated. A significant increase in the concentration of Cu, Cd, and Fe has been observed by decreasing the particle size in different land uses. The contamination factor (CF) for particle sizes <2000 and <63 were ordered as Cd>Mn>Pb>Ni>Cu>Zn>Fe and Cd>Mn>Cu>Ni>Pb>Zn>Fe, respectively. The CF index indicates that the orchard soils for Cd were considerably polluted and for other metals moderatly polluted. Positive and significant amount of geo-accumulation index (Igeo) for Cd and Mn was observed for both soil particle classes in all land uses. Overall, the results of this study confirmed concentration of some heavy metals in smaller particles size. Comparing contaminants concentration of Cd and Mn in croplands and orchards soils with the range lands soils indicated anthropogenic effects on soil pollution. The results revealed risk of heavy metals in the watershed and necessity of reconsidering management policies.

Nowadays, international concern about the impact of antibiotic residues on the environment increased and their removal has received a lot of consideration. The aim of this study was to investigate the efficiency of Fenton’s advanced oxidation process (H2O2/Fe+2) in sulfadiazine antibiotic removal from aqueous solutions. An experimental-laboratory scale study was done on a synthetic wastewater containing sulfadiazine antibiotic with 0.079, 0.19, and 0.47 mM concentrations under Fenton’s process. Then optimal values of affecting parameters, such as initial antibiotic concentration, molar ratio of reagents, [Fe+2] and [H2O2] concentration, detention time, and pH, were determined. The discharged effluent analyzed by HPLC-UV to identify the antibiotic residues. The results showed that the optimal parameters in the Fenton’s oxidation process to remove the sulfadiazine included antibiotics at pH 3.5, molar ratio of [H2O2] / [Fe +2] equal to 1.5, and contact time of 15 minutes, respectively. In these optimal conditions, the efficiency of removal of antibiotic in concentrations of 0.079, 0.19, and 0.47 mM were 99.82%, 97.97% and 78.23% and the wastewater COD removal degrees were 83.33%, 78.57%, and 78.57%, respectively. The experiments showed the efficient removal of sulfadiazine antibiotic in wastewater by Fenton’s oxidation process. The efficiency of this method can also be considered in eliminating other antibiotics resistant to biological treatment.