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در این پژوهش حساسیت تبخیر-تعرق ذرت به تنش آبی، در مراحل متمایز رشد و برای شرایط کاربرد مقادیر مختلف آب آبیاری بررسی شد. آزمایش به‌صورت فاکتوریل و در قالب طرح بلوک‌های کامل تصادفی انجام شد. تیمارهای آبیاری شامل چهار سطح (I0)100، (I1)80، (I2)60 و (I3)40 درصد نیاز آبی گیاه و تیمارهای مراحل رشد شامل چهار مرحله‌ی اولیه، توسعه، میانی و پایانی رشد بود. تبخیر-تعرق روزانه گیاه بر اساس بیلان آب خاک در منطقه ریشه اندازه‌گیری شد. مقادیر تبخیر-تعرق در مراحل رشد مذکور به‌ترتیب برابر با 79، 8/201، 8/123 و 6/14 میلی‌متر (در تیمار I0)، 3/78، 196، 6/112 و 6/14 میلی‌متر (در تیمار I1)، 72، 6/173، 99 و 7/11 میلی‌متر (در تیمار I2)، 8/62، 5/147، 5/81 و 4/8 میلی‌متر (در تیمار I3) اندازه‌گیری شد. مقدار عملکرد خشک ذرت در تیمارهای I0، I1، I2 و I3 به‌ترتیب برابر با 1/17، 8/15، 6/12 و 7/8 تن بر هکتار بود. در کل دوره رشد و در سطوح آبیاری I1، I2 و I3، مقدار تبخیر-تعرق نسبی ذرت به‌ترتیب 6/95، 85 و 6/71 درصد و مقدار عملکرد نسبی محصول به‌ترتیب 4/92، 7/73 و 9/50 درصد برآورد شد. در این پژوهش ضرایب حساسیت درون فصلی تبخیر-تعرق ذرت به تنش آبی، از طریق مدل جنسن مدل‌سازی شد. به‌این صورت که برای داده‌های واقعی هر تیمار تحت تنش (I1الی I3) و در مراحل اولیه، توسعه، میانی و پایانی رشد ذرت، به‌ترتیب ضرایب حساسیت الی (موجود در مدل جنسن) توسط نرم‌افزار SPSS برآورد شد. میانگین ضرایب مذکور در تیمارهای تحت تنش به‌ترتیب برابر با 421/0، 37/1، 274/0 و 133/0 تعیین شد. برای صحت‌سنجی مدل جنسن در تخمین عملکرد نسبی واقعی ذرت، از آماره‌های ارزیابی ، EF، RMSE، ME و CRM استفاده شد. آماره‌های مذکور به‌ترتیب برابر با 998/0، 986/0، 753/2، 026/0 و 021/0 محاسبه شد که نشان‌دهنده کارایی خوب مدل در تخمین عملکرد نسبی محصول بود. همچنین در سطوح مختلف آبیاری، بین دو پارامتر تبخیر-تعرق و عملکرد زیست‌توده خشک ذرت، رابطه‌ی Y=69.935ET-12281 با ضریب همبستگی 999/0 برازش داده شد. انتخاب مرحله‌ی رشد مناسب به‌منظور اعمال تنش آبی و سطح تنش وارده، تأثیر به‌سزایی در مقدار تبخیر-تعرق و تولید زیست‌توده گیاهی داشت. دستاورد کاربردی پژوهش این بود که با استفاده از مدل‌ها و روابط بین تبخیر-تعرق و عملکرد گیاه، می‌توان بر اساس مقدار تبخیر-تعرق واقعی و تحت مدیریت در مراحل مختلف رشد، مقدار عملکرد واقعی محصول را تخمین زد. همچنین با توجه به تأثیر شدت تنش آبی بر کاهش تعرق گیاه و افزایش تبخیر از سطح خاک، استفاده از مالچ روی خاک به‌خصوص در مراحل اولیه و پایانی رشد قابل توصیه بود.

Background and Objective: In today's society, preparing healthy food has become challenging due to the variety of food production methods. Oil is produced in several ways in our country. In the cold pressing method, there is insufficient monitoring of the manufactured product. The aim of the present study is to investigate the physicochemical characteristics and the levels of heavy metals of industrial oil compared to cold-pressed oil. Materials and Methods: In this research, 54 samples of sunflower, sesame, and canola oil produced by both cold pressing and industrial refiningmethods were prepared. Their physicochemical characteristics, including refractive index, acid value, iodine value, saponification value, peroxide value, anisidine value, as well as the concentrations of lead, iron, arsenic and copper were determined. Additionally, the effect of storage time on these characteristics was investigated. Results: The Iodine number showed the highest deviation from the standard (61%), with an average of 136.70 gI/100g for the cold-pressed oil and 134.48 gI/100g for industrially refined oiland. The average value of the physicochemical characteristics, except for the saponification value, were higher in the cold-pressed oil samples compared to the industrially refined oil samples, but the observed difference was not statistically significant. An investigation into the effect of storage time on physicochemical properties revealed a significant increase in peroxide value (p<0.01) and anisidine (p <0.05) in both oil groups over a two-month period. The average concentration of arsenic, lead, iron and copper in the studied oils was 0.03, 0.78, 0.05 and 0.05 mg/kgoil, respectively. A deviation from the standard was observed only in one sample of cold-pressed sunflower oil, with an arsenic concentration of 0.11 mg/kgoil). Conclusion: Based on the obtained results, the refined industrial oils exhibited more favorable chemical characteristics and stability. It is suggested that cold-pressed oils should be consumed within a short period of time. For frying purposes, refined industrial oils are preferable. [ABSTRACT FROM AUTHOR]

Simulation of water uptake amount during crop growth period, leads to optimal management of water consumption. This research was conducted on maize S.C 704 in lysimetric space (in Qazvin), in 2021. The research aim was simulation of salinity stress effect on crop water uptake amount. The experiment was performed as factorial and in a completely randomized design. The effect of soil salinity with levels of; 0.5(S1), 1.7(S2), 2.5(S3), 3.5(S4), 4.5(S5), 5.5(S6), 6.5(S7) and 7.5(S8) dS.m-1, were investigated in growth stages of initial(P1), development(P2), mid(P3) and late(P4). For simulating the amount of water uptake reduction in salinity stress conditions, the functions of Van Genuchten, Van Genuchten-Hoffman, Dirksen-Augustijn and Mass-Hoffman were used. Models calibration was done by real data in S1, S3, S5 and S7 treatments and models evaluation was done in S2, S4, S6 and S8 treatments. The models calibration was done once for whole growth period (by constant coefficients) and again by considering the crop growth stages sensitivity (by variable coefficients). The slope of water uptake reduction at P1 to P4 stages and whole growth period, was estimated to be 6.81%, 7.4%, 9.13%, 4.25% and 7.9%, respectively. The highest to lowest crop sensitivity to salinity stress was observed in P3, P2, P1 and P4 stages, respectively. The functions calibration for whole growth period, was less accurate for determining the water uptake amount. Evaluation statistics (CRM: -0.0005, EF: 0.993, R²:0.995, RMSE: 0.016 and ME:0.031) showed that the Mass-Hoffman function was optimal model for simulation the water uptake reduction. By considering the effect of crop growth stages sensitivity, were done a more accurate estimation of water uptake and actual crop water requirement amounts. [ABSTRACT FROM AUTHOR]

The aim of this study was to produce a suitable cake with reduced fat with the help of apple pomace fiber as a fat substitute. After preparing fiber from apple pomace by water extraction method, first some properties of this fiber were evaluated. Due to the low amount of fat and energy and the amount of crude fiber, the extracted apple fiber was able to replace carbohydrate-based fat for flour products. In this study, optimization of the cake production process by three factors, including apple fiber with a ratio of (0.5, 10%) and oil (16.38, 15.47, 14.57%) with a shelf life of 0, 15 and 30 days. Response method was performed. The result showed that with increasing the amount of fiber moisture, fat, firmness and adhesion, the springiness of the cakes increased and the volume decreased. With increasing shelf life, moisture, fat, aw increased and the firmness and stickiness of cake spring decreased. The results of this study show that the cake containing 5.163% fiber and 14.9% oil in 8 days was the best sample. The results showed that the use of apple pomace in the cake reduced the fat content by 9.3% compared to the control sample. According to the optimization results, the optimum sample moisture content is 22.847%, water activity 0.850%, fat 15.018%, specific gravity 82.737 cm3/g, hardness 10809 (N), spring content 0.747 cm and the amount of adhesion was determined to be 0.392. [ABSTRACT FROM AUTHOR]