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Sclerotinia stem rot (SSR), caused by Sclerotinia sclerotiorum, is one of the most important diseases of canola (Brassica napus) in Golestan province, the leading canola producer in Iran. In order to assess the yield loss of canola caused by SSR, 80 fields were surveyed in four different regions of the province (Gorgan, Ali Abad, Kalaleh and Gonbad) during 2006-2007, and SSR intensity was recorded weekly in the fields. Study of yield loss-SSR severity relationships by linear, nonlinear and multiple regression analyses with final intensity (S_f), time to initial symptoms (t_is), Gompertz rate of disease progress (r_G), and standardized area under disease progress curve (SAUDPC) as independent variables indicate that single point and integral models were significant (P < 0.05) only in three cases. Results of multiple point models which were performed using weekly recorded SSR intensities (S₁, S₂, …), were significant in two cases and a general model for 2007 survey was developed using S₃ to S₆. Eventually, response surface models were developed for each region by integrating t_is with SSR intensity variables (S_f or SAUDPC).

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Present study describes the approach of applying Response Surface Methodology (RSM) with a Pareto-based multi-objective genetic algorithm to assist engineers in optimization of sheet metal forming. In many studies, Finite element analysis and optimization technique have been integrated to solve the optimal process parameters of sheet metal forming by transforming multi objective problem into a single-objective problem. This paper aims to minimize the objective functions of fracture and wrinkle simultaneously. Design variables are blank-holding force and draw-bead geometry (length and Diameter). Response surface model has been used for design of experiment and finding relationships between variables and objective functions. Forming Limit Curve (FLC) has been used to define the objective functions. Finite element analysis applied for simulating the forming process. Proposed approach has been investigated on a cross-shaped cup drawing case and it has been observed that it is more effective and accurate than traditional finite element analysis methods and the ‘trial and error’ procedure.

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This study aimed to optimize the formulation of chitosan-caffeic acid nanogel containing Shirazi thyme (Zataria multiflora) essential oil (ZEO) and nisin. The independent variables (the concentration of chitosan nanogel, Shirazi-thyme, and nisin) were optimized based on the highest zeta potential and encapsulation efficiency, besides the lowest particle size and IC₅₀(DPPH) values. The results of The Box-Behnken experimental design and Stepwise-response surface model showed the optimal nanogel formulation was as follows: chitosan concentration= 0.4 g; ZEO= 157.1 ppm and nisin= 10.1 ppm. The particle size, zeta-potential, antioxidant activity, and encapsulation efficiency of the optimal chitosan-ZEO-nisin nanogel were 411.39±18.11 nm, 32.90±1.10 mV, 0.79±0.06 mg.mL^-1, 71.06-82.69% respectively. Moreover, the addition of optimized nanogel to the Iranian white cheese formulation showed that the treated cheese samples with ZEO and nisin (free or encapsulated in chitosan nanogel) improved the microbial quality of chess. The antimicrobial activity of the ZEO and nisin encapsulated in chitosan-caffeic acid nanogel was higher than a free form of ZEO-nisin. The Coliforms population of cheeses treated with sodium nitrate and chitosan nanogel containing ZEO-nisin was acceptable during 60 days of storage. During the storage period, the most changes in the color and texture (hardness) of the cheese samples were related to the control sample, and the least change was obtained for samples treated with sodium-nitrate and chitosan nanogel (P < 0.05). Also, the sensory quality of the sample containing ZEO and nisin was acceptable for the sensory evaluator. The sample containing chitosan nanogel received an acceptable sensory score (> 3) during 60 days of storage. In general, the potential of the nanogel in increasing the shelf-life of Iranian white cheese was comparable with sodium nitrate.