mohammad passandideh

A national project was carried out in 10 provinces in order to compare the fertilization method of farmers with the integrated method of soil fertility recommendation for canola plants. The experiment included 54 farms in the provinces of Golestan, Mazandaran, Khuzestan (Dezful), Khuzestan (Ahvaz), Ardabil (Maghan), East Azerbaijan, Isfahan, Bushehr, Khorasan Razavi, Kermanshah, Fars and Varamin regions. These areas consisted of a wide range of canola cultivation regions, climatic conditions and a different range of soil characteristics. In a part of selected fields, fertilization was recommended based on the soil test (optimal use of fertilizers) and in the other half of the fields, application was according to the traditional method of the farmer in the region. At the end of the growth stage, the seed yield of treatments was compared in each province and in each region. According to the results, phosphorus had the highest percentage of deficiency in the soil of the fields, and among the micro nutrients, the highest deficiency was related to the zinc element. On average, the increase in grain yield of first year was 600 kg ha-1 or 24%, compared to the conventional treatment. In the second year, the increase in grain yield was 784 kg ha-1 or 27.4%. For the average of two years, the amount of 692 kg ha-1 or 25.7% increase in grain yield was obtained. The benefit to cost ratio of different regions depended on the characteristics of the soil and the amount of used fertilizers. The highest value of this ratio was obtained from the region of Neishabur (26.52) and Darab (22.31. The lowest was obtained from Bushehr (0.28). The results showed that the consumption of fertilizers with considering the time, quantity, source and method of application will improve the yield of canola in all regions.

Canola is known as one of the most important oily plants in the world due to its good composition of fatty acids and oil content. As the first oilseed crop in Iran, Canola is recommended to increase its cultivated area to reduce dependence on oil imports with high oil quality compared to other similar crops. Drought stress is one of the major environmental limiting factors for the successful production of crops, especially canola, in Iran and the world. One effective strategy to reduce the adverse effects of drought stress is to use new nutritional techniques like humic compounds and growth stimuli, including amino acids. Due to the lack of sufficient studies on the effects of growth stimuli on canola, the present study was performed to study the effects of four plant growth biostimulants on increasing canola tolerance to drought stress under Moghan conditions.

To compare the effects of growth biostimuli on canola yield under drought stress, an experiment was conducted at Moghan Agricultural Research Station in the 2018-2019 crop years. The experiment was conducted as a split-plot in a randomized complete block design with three replications. Treatments included the main factor of irrigation regime at two levels, and the sub-plot included six treatments; control, amino acid foliar application, humic acid with irrigation, fulvic acid foliar application, seaweed extract foliar application, and the combination of second, third, and fifth treatments. In this study, plant height, number of pods per main stem, number of pods per lateral branches, total number of pods per plant, number of seeds per pod, 1000-seed weight and seed yield were measured. Before analysis of variance, the presence or absence of outliers was identified using Grubbs test. Normality of data was then checked by Shapiro-Wilk test. Finally, the analysis of variance was performed and the means were compared using the least significant difference (LSD) method at the statistical level of one and five percent using SAS software version 9.1.

The results showed that the effect of growth biostimulants could be different in non-stress and drought stress conditions, and biostimulants can reduce the effects of dry stress. in regular irrigation and non-stress conditions, the combined treatment uses of growth stimulants> humic acid> fulvic acid > seaweed extract> amino acid increased by 22.7%, 14.3%, 6.4%, 6.3%, and 3.4%, respectively, compared to the control treatment. In drought stress conditions, the highest effect was related to the combined use of growth stimulants> amino acids> seaweed extract> fulvic acid > humic acid, respectively, with an increase of 31.9%, 21.3%, 15.9%, 11.9%, and 11.1%, respectively, compared to the control treatment.

Under non-stress conditions, the effect of growth stimulants was related to all studied components yield, and the effect of humic acid, fulvic acid, seaweed extract, and amino acid were related to the number of pods. Under stress conditions, other yield components including, number of pods per main stem and lateral branches, plant height and number of seeds per pods had more effect on increasing yield. It can be concluded that the application of growth biostimulants while improving canola yield under normal moisture conditions, can increase its tolerance to drought stress.

Study has shown that the soil available-P content in 71.8% of the agricultural lands in Iran falls below 15 mg. kg-1. Moreover, excessive use of P-fertilizers in calcareous soils not only increases costs but also leads to P-accumulation and reduced uptake of micronutrients, especially Zinc, to pose serious threats to public health. Generally, only a small percentage (15‒20%) of P-fertilizers used each year may be absorbed by plants while the remaining portion precipitates to increase soil total-P in lands with high pH levels. This process can cause environmental problems in areas close to lakes or those near surface waters used to supply drinking water. These observations warrant the quest for indicators that address both plant requirements and adverse environmental effect. It is worth noting that P is far more easily released in calcareous soils than in acidic ones because the bond between phosphate ions and calcium is by five times weaker than that between phosphate ions and iron or aluminum. It may, therefore, be concluded that application of P fertilizers should be based on local soil analysis and that P fertilizers should be recommended in soils whose available phosphorus concentration is below a critical level. Thus, such appropriate practices as applying P- fertilizers with due consideration of soil analysis results, increasing soil organic matter, and using P solubilizing bio-fertilizers may be recommended in order not only to enhance uptake of soil non-available P but to meet plant requirements, optimize fertilizer consumption, and prevent environmental hazards as well.

Numerical investigations of the effects of ocean water waves on the structures and also the devices designed to capture energy from waves, primarily need proper generation of desired water waves with Specific features. In this study, a numerical method for generation of nonlinear irregular waves is proposed for viscous flow simulations based on Navier-Stokes equations. The numerical method is based on a control-volume approach where a two-step projection method is used to solve the governing equations. In this regard, the motion of the flap-type wavemaker inside the water is simulated using the fast-fictitious domain method, the VOF method is used to capture the free surface evolutions and high-viscosity regions are employed to damp the reflecting waves. First, various methods of wave generation for the numerical wave tanks, available in the literature, are reviewed and next, three waves with different wave steepness are simulated to demonstrate the capabilities of the proposed method. Results show that the method can effectively produce irregular waves, from linear waves up to the steep nonlinear ones. Furthermore, shallow to deep water waves can be generated with reasonable accuracy using the proposed method.

In this study, the boiler of Mashhad Toos power plant is studied numerically in order to investigate the possibility to improve its efficiency and reduce its pollutants emission. In this regard, first the current status of the boiler is simulated and the numerical results are compared with the available experimental data, where a good agreement is observed. Next, the effects of the injected fuel droplets’ diameters, air flow rate and the inlet air swirl direction arrangement on the boiler thermal efficiency and pollution emissions are studied. An appropriate arrangement of the inlet air swirl directions for the nine liquid-fueled burners of the boiler is proposed that will lead to a higher boiler thermal efficiency and lifetime.

Zeolites with their crystallized structures which with their pores act on sieve and due to having open channels in their net, let to some ions by passing and acting as dam on going way of some other ions. There is some cations such as NH4 and K in their structure. Using of this material in soil may improve nitrogen efficiency and reduces its loss. A factorial experiment in a completely randomized design with three replications was performed in a green-house study to evaluation the effects of zeolite on corn shoot yield and nitrogen efficiency in 2008-2009. First factor was sources of N fertilizer (five kind), second factor was four levels of nitrogen (0, 200, 250 and 300 kgNha-1) and variety of corn was SC 704. Shoot dry weight and nitrogen concentration was determined in upper plant part. Results indicated that nitrogen in tested zeolits couldn’t act as slow release fertilizers (such as SCU) therefore they couldn’t be as suitable replacement for slow release fertilizers. Ratio of nitrogen in zeolite fertilizers is 1/3 of urea, therefore farmers has to use three times more amount of it to prepare same nitrogen for plants. If we consider other inputs such as packing, transporting and the cost of zeolite material, the cost of each nitrogen unit in this material is more expensive than urea. Due to these results using of nitrogenous zeolite which was tested in this experiment is not scientific and economically recommendable for corn cropping.

In this paper, the dynamics of evaporation of water droplets on surfaces with different contact angle hysteresis is studied experimentally and theoretically. The evaporation of water droplets on surfaces usually occurs in three distinct stages, namely the constant contact area mode, followed by the constant contact angle mode, and the mixed mode in which both contact angle and contact area are decreased. Due to the unknown nature of the time dependency of both the dynamic contact angle and contact radius, solving the governing equations for the evaporation rate of a droplet is complicated. The experimental observations performed in this study for the evaporation of sessile droplets on different solid substrates under various conditions shows that the surfaces with a high contact angle hysteresis remain more in the constant contact area mode. On the other hand, the surfaces with a low contact angle hysteresis remain more in the constant contact angle mode. Based on these observations, it is assumed that the entire process of evaporation on surfaces with high and low contact angle hysteresis occur in a dominated mode. Next, based on this assumption, the governing equation for the droplet evaporation for both surfaces is solved separately using a theoretical model. A good agreement is observed between the results of the theoretical analysis with those of the experiments; this confirms the validity of the proposed theoretical model.

Expansion and economical importance of yield reduction due to iron deficiency chlorosis in the world has attracted many researchers attention. Different materials, such as iron sulfate, acidified remediation, wastes, by-products of industries, iron chelate and organic compounds, have been tested to correct iron chlorosis. This experiment studied effect of applying an iron fertilizer for corn (SC 704) consisting sulfur and Thiobacillus bacteria. Experiment was carried out in greenhouse in factorial with complete of randomized design in four replications. The first factor was two kinds of irrigation water, w1= irrigation with ordinary water of soil and water research station of Karaj and w2= irrigation with acidified water of station with pH of 5-5.2 (acidified with sulfuric acid). The second factor was seven iron fertilizer treatments, T1=Control (without iron fertilizer); T2= Iron sequestrine 138 (10 mg. kg-1), T3= Iron sulfate (110 mg.kg-1), T4= Iron oxide powder of iron ore (220 mg.kg-1), T5= T4 + sulfur (250 mg.kg-1 powdered sulfur) + Thiobacillus inoculant (104 cell.gr soil -1), T6= T5 + organic matter, T7= T3 + organic matter. Nitrogen, potassium, triple superphosphate, Mn, Zn, Cu sulfates and acid boric was used 200, 85, 90, 10, 5, 10 and 5 mg. kg-1, respectively. In the end of experiment, Dry shoot and root weight, iron uptake, chlorophyll Index (SPAD 502) and Fv/Fm were measured. Based on results, acidified irrigation water had significant effect on shoot dry weight and P and Fe uptake at five percent probability level, but had no significant effect on chlorophyll index. Effects of different fertilizer treatments on dry weight, P and Fe uptake and chlorophyll index, against Fv/Fm, were significant on five percent level. T6 and T7 produced highest shoot dry weight and T2 produced the lowest. The highest amount of P and Fe uptake was belonging to T7 and the lowest was belonging to T2. The highest amount of chlorophyll index was belonging to T6. Between treatments there was no significant difference on Fv/Fm factor.

Contact angle has an important effect on the dynamic behavior of a droplet during its impact onto a solid surface; this behavior includes deformation, spreading and even rebounding of the droplet from the surface. In this paper, the effect of contact angle during droplet impact is studied and numerically simulated. First, using molecular-kinetic theory and based on the newly available research in this field, a correlation for determining the dynamic contact angle during droplet impact is obtained. This correlation is then implemented in the numerical model used to simulate the process. The results of the numerical model are compared with those of the experiments and those of the previous models (using an equilibrium contact angle; two advancing and receding contact angles). Model predictions agreed well with experimental measurements; this validated the model results for the droplet deformation during the impact. The results show that using the molecular-kinetic theory in modeling contact angle prevents the spreading-and-recoiling oscillations of the droplet that are seen when an equilibrium contact angle is used. Compared to the model with advancing and receding contact angles, the molecular-kinetic theory results in a better prediction of the time and value of the maximum and minimum spread of the droplet on the solid surface. Based on the results of the developed model, a critical maximum spread and two regions of droplet spreading or rebounding from the surface are defined. Next in the paper, an analytical model is presented to study the effect of contact angle on the droplet maximum spread. The results of this model show that for low Capillary numbers (Ca) with an increase of the equilibrium contact angle or a decrease of We number, the maximum spread of the droplet is decreased and becomes less dependent on Re number. In contrast, the maximum spread for high We numbers or low equilibrium contact angles is increased and becomes more dependent on Re numbe

In this paper, the inclined impact of a droplet on a solid surface in a spray coating process is studied using both numerical and analytical models. The numerical simulation is based on a previously developed model that includes the solution of Navier-Stokes equations along with an equation for the liquid free surface. The contact angle is modeled using two advancing and receding angles at the liquid front on the solid surface. The close agreement between the results of the numerical model with those of the experiments shows that the model can accurately predict the droplet impact behavior. Using the balance of droplet energy before and after the impact, a simple analytical model is presented for the maximum spread of a droplet during an inclined impact. This model is an extension of a previously developed model for the normal impact of a droplet on a solid surface. A comparison between the results of the analytical model with those of the simulations and experiments verifies the accuracy of the analytical model predictions for the maximum spread of a droplet in a spray coating process. Based on the analytical model, for high Reynolds numbers and small angles of impact, the effect of Weber number on the maximum spread is increased. For low Reynolds numbers and impact angles close to 90o, the maximum spread remains nearly constant