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Showing 49 results for Spray


Volume 0, Issue 0 (1-2024)
Abstract

Potassium (K) mitigates the effect of high temperature on canola, especially during its later growth stages when sowing of canola is delayed. To explore the effect of K on high temperature tolerance and canola production a field experiment (2019 – 2021) was conducted. The experiment had two sowing dates (October 15 and November 1) and four K treatments, i.e. control, soil application (50 kg K ha-1), soil application + 0.25% K foliar spray at pre- and post-flowering stages and soil application + 0.50% K foliar spray at pre and post-flowering stages. Application of 50 kg K ha-1 as soil application along with 0.50% K-foliar sprays resulted in higher production of biochemicals (superoxide dismutase, peroxidase, catalase, and total soluble sugars) besides net photosynthetic rate and stomatal conductance along with less malondialdehyde production and relative cell injury in crops sown on November 1st than untreated plants. Moreover, it also enhanced chlorophyll florescence and chlorophyll (a and b) contents of late- sown crops. Plants sown on November 1st and received 50 kg K ha-1 as soil application along with 0.50% K foliar spray also gave a higher yield components, yield and economic returns than control. Therefore, it is suggested to supply 50 kg K ha-1 at sowing and a foliar spray of 0.50% K at the pre- and post-flowering stages to canola crops sown late in the season to achieve optimal and economical yield levels.
 

Volume 0, Issue 0 (8-2024)
Abstract

Fire can not only lead to many human and financial losses, but also can cause structures to collapse and destroy them. For this reason, it is necessary and inevitable to protect buildings against fire and conduct more research in the field of better understanding the effects of combining different materials with each other and obtaining materials with greater resistance to fire. Concrete and concrete structures are always used by construction engineers due to their resistance, availability and resilience against fire. Ordinary concrete loses its strength at high temperatures, and the use of unreinforced concrete is not very useful due to its brittleness and weakness in tensile strength. In concrete, the tensile strength is lower than its compressive strength, and for this reason, researchers are trying to increase the resistance to fire and heating by improving the tensile strength of concrete. Reinforcing concrete with rebar is always a solution to increase the tensile strength in concrete parts, one of the most important weaknesses of using rebar in concrete is that the reinforcements form a small part of the concrete cross-section and actually cause the concrete to be inhomogeneous. In this research, double-bent steel fibers have been used to overcome the mentioned weakness and reinforce the concrete. It should be noted that concrete containing steel fibers has favorable compressive and tensile strength due to the high tensile strength of steel fibers. In order to achieve this goal and achieve fiber concrete that has good fire resistance, we defined seven different mixing plans with different percentages of steel fibers and lubricants. Concrete samples were produced using double-bent steel fibers in amounts of 0.5, 1, and 1.2 percent by volume of concrete and superlubricant in 0.5, 1, and 1.3 percent by weight of cement, and then in Cubic molds with dimensions of 10x10x10 cm and cylindrical ones were sampled as standard, and after setting the cement, the 28-day-old concrete samples, after heating and placing inside the electric heater with different temperatures, were divided into two The method of gradual cooling with ambient air and fog spraying (water spraying) is similar to what firefighters do when extinguishing a fire, after measuring the amount of weight loss of the heated samples, the weight loss values ​​were presented in the form of a diagram, then the samples were subjected to tests Compressive strength, tensile strength (Brazilian test) and ultrasonic wave speed (ultrasonic test) were placed, and the results and data of each of them for each mixing design were presented in the form of a diagram after examination and classification, so that the effect of high heat on Concrete containing steel fibers and super-lubricant should be determined. The results clearly showed the improvement of the tensile strength in three volume percentages of fibers by 14.6, 16.8 and 64.5%, respectively, compared to concrete without fibers, and also the compressive strength of concrete after bearing the heat of 250 degrees Celsius and cooling to the fogging method had 44.5, 31.6, and 9.3 percent, respectively, and in the gradual air cooling method, the compressive strength was 43.3, 44.9, and 50 percent, respectively.


 

Volume 1, Issue 1 (7-2004)
Abstract



Volume 3, Issue 4 (12-2014)
Abstract

Variable rate spray applications using proportional control systems can greatly reduce pesticide use and off-target contamination of environment in orchards. Variable rate spraying of the canopy allows growers to apply pesticides only to the target, only use the correct quantity according to canopy size, season and growth stage and to apply plant protection products in an economic and environmentally sound manner. A major challenge is the reduction of agrochemicals used as Plant Protection Products (PPP) while achieving suitable deposition on the canopy. Spraying efficiency can be improved by reducing the spray losses associated with deposition on the ground and off-target drift. Adjustment of application rate proportional to the size and shape of tree crops has shown high potential for reducing agrochemicals in automatically controlled sprayers. In recent years target detection methods have been developed by using advanced techniques such as vision and laser scanning systems or simpler ultrasound, infrared and spectral systems. These systems have made it possible to develop geometric maps of trees allowing site-specific management of orchards. Variable rate spraying can thus be utilized as a methodology for applying the required amount of PPPs to the canopy while preventing over dosage as well as drift. Utilization of sensors to monitor canopy, distances and location ensures better use of expensive inputs, resulting in a sustainable approach to an important practice. This paper discusses various methodologies available for determination of canopy structural parameters and introduces some applicable commercial systems while pointing out their similarities and differences.  

Volume 4, Issue 2 (6-2015)
Abstract

Laboratory and field experiments were conducted to determine the efficacy of some insecticides on the control of Sarta longhorned beetle, Aeolesthes sarta Solsky adults and larvae. In the laboratory, three pairs of mated and non-oviposited adults were released on the logs of field elm, Ulmus minor Mill that had been treated with chlorpyrifos, carbaryl, permethrin or imidacloprid. In the field experiments, artificially infested U. minor var. umbraculifera Rehd trees were treated by imidacloprid and oxydemeton-methyl through soil and trunk injection. In the laboratory test the best results were obtained from imidacloprid and permethrin applications, because of occurrence of high adult mortality after short period and also preventing egg laying. Despite a few eggs that were laid on the chlorpyrifos treated logs, there were no living larvae in the sprayed logs. Results of the field tests showed that the number of living larvae did not differ significantly between oxydemeton-methyl and control treatment, however, imidacloprid injection was effective in controlling this pest.

Volume 10, Issue 3 (6-2021)
Abstract

The previous works have addressed selecting the nozzle to minimize the hazard of pesticide drift by producing large spray droplet sizes. However, this spray application with the largest sizes does not effectively impact insects either, as it needs many pesticides. Several studies have demonstrated that the small spray droplet sizes can affect the insects and be obtained by selecting the appropriate nozzle size and height. This study sheds light on the nozzle sizes and heights, and insecticide types for controlling the cabbage aphid to ensure efficient insect control. Different parameters including three sizes of flat fan nozzle 01, 02, and 03, two nozzle heights 35 and 70 cm above the plant top, and two insecticide types 20% wide plus WP and 90% methomyl SP were investigated to measure spray deposition, coverage percentage, and droplets density in different locations of the cabbage plant for improving control efficacy. The outcomes showed significant differences in the spray deposition and coverage percentage using different nozzle sizes, nozzle heights, and insecticide types. The best spray deposition, coverage percentage, and control efficacy (0.321 µm.cm-2, 15.05%, and 84.83%, respectively) were achieved using the 02 nozzle size, nozzle height of 35 cm methomyl SP insecticide type on the fourteenth day after spraying application in comparison to the others. The fourteenth day was the most effective to control aphids compared to the first and the seventh days.

Volume 11, Issue 3 (7-2009)
Abstract

In this study, an electrostatic sprayer which had been previously designed and constructed was evaluated in order to quantify the charging of droplets. Liquid atomization was achieved by using an ultrasonic nozzle. The nozzle maximum flow rate was 25 milliliters per minute and vibration frequency was about 30 kHz. The induction method was used for charging the output droplets. All experiments were carried out within a closed environment with a fixed ambient humidity and temperature to reduce the effect of environmental factors. The independent parameters in this study included: voltage at four levels of 1.5, 3, 5 and 7 kV; air flow speed at six levels of 14, 14.9, 17, 20.2, 21.6 and 23 m s-1; charging electrode radius in two levels of 10 and 15 millimeters, horizontal distance between the electrode and nozzle tip at four levels of 1.5, 6, 10 and 15 millimeters; and liquid flow rate at three levels of 5, 12 and 25 milliliters per minutes. For evaluation of the system, the charging quantities of droplets were measured in different states. The maximum charging occurred at 5 ml min-1 flow rate, voltage of 7 kV, air flow speed of 23 m s-1 and the resulting current was 0.24 μA. On dividing the electrical current by the liquid flow rate and changing the scale, the mean charge to mass ratio was 1.032 μC g-1. Increasing voltage increased the charging quantity slightly but higher voltages and lower air speeds decreased it. The effect of the faster air speed on droplet charging phenomena is positive and the smaller electrode radius causes less charge induction on the droplets. The quantity of droplets charging first increased with increased distance between ring electrode and nozzle tip, and then it was either reduced and/or fixed.

Volume 11, Issue 42 (2-2014)
Abstract

Probiotic yogurt is one of the most common and important probiotic products in the market. Researchers have revealed that the survival of probiotic organisms in yogurt during storage has often been low. An appropriate technique to preserve the survival rate of these organisms is to prepare yogurt powder using spray drying. The objective of this study was to investigation the effect of ingredient supplementation on survival of bacteria in probiotic yogurt during spray drying process. Effect of supplementing milk before preparing probiotic yogurt with various of ingredient (including whey protein concentrate, maltodextrin powder (DE=10-12), lactose, sodium caseinate and skim milk powder at a level of 1.5% (w/v) on survival of bacteria in probiotic yogurt powder after spray drying using inlet air temperature of 150 ˚C, air flow rate of 478 m3/h and feed flow rate of 2 L/h was investigated. The results indicate that supplementing milk with various ingredients prior to preparing probiotic yogurt not only enhances the growth of bacteria in fresh yogurt but also improve the survival rate these bacteria following spray drying and preparation of probiotic yogurt powder.    

Volume 12, Issue 3 (11-2023)
Abstract


This study aimed to assess the effect of a time gap between adding adjuvant and herbicide to the tank on hard-water antagonism of trifloxysulfuron under greenhouse conditions. Treatments consisted of herbicide dose (0, 0.75, 1.5, 3, 6, and 12 g ha-1), spray carrier (distilled water ± 600 mg MgCl2, CaCl2, and FeCl3 L–1), the order of adding adjuvant and herbicide to the spray carrier (herbicide alone, the addition of 20 g ammonium sulfate L-1 or 300 mg citric acid L-1 15 min before, at the same time, and 15 min after adding trifloxysulfuron to the spray carrier). The dry matter of velvetleaf was regressed over the doses of trifloxysulfuron to obtain herbicide doses in which 50 and 90% velvetleaf control occur (ED50 and ED90, respectively). The presence of Mg2+, Ca2+, and Fe3+ in the spray carrier increased the ED50 from 2.41 to 5.07, 7.65, and 9.78 g a.i. ha-1 and the ED90 from 5.88 to 16.56, 28.48, and 28.19 g a.i. ha-1, respectively, indicating a hard-water antagonism of trifloxysulfuron as Fe3+ = Ca2+ > Mg2+. Generally, the best order was adding adjuvants 15 min before adding trifloxysulfuron to the tank. It could completely overcome the hard-water antagonism of trifloxysulfuron. In contrast, the order of adding adjuvants 15 min after adding trifloxysulfuron to the tank had no significant effect on overcoming the hard-water antagonism of trifloxysulfuron, resulting in additional costs for farmers.

 

Volume 12, Issue 48 (9-2015)
Abstract

Production and export of Doogh as a Iranian fermented national drink have increased. Contamination of Doogh by yeasts and molds is one of the defects that results in spoilage and increasing the waste of  the product. Drying and convertion of Doogh to its powder by spray dryer is one of the method for increasing the shelf life and decreasing the volume and the costs of transportation. In this study Doogh samples with fat content ( 0.5% and 1.5%), dry matter without fat and salt (3.5% and 4.5%) and 0.7% salt were first dried in preliminary tests including inlet air temperature ( 100, 150 and 200 oC), liquid feed flow rate (5,10 and 15 mL min˗1 )  and drying air flow rate ( 400, 600 and 800 L h˗). Best condition were adjusted accordingto the best results of solubility test  and were conducted to drying the samples. fat content and dry matter had significant effect on physical, chemical and microbial characteristics of Doogh powder. First and  forth formula had highest and lowest solubility. The solubility of first and forth formula was 82.11±0.62% at 25 oC and 63.18±0.33% at 15 oC respectively. Increasing the fat content results in decreasing the solubility, increasing the particle size and the rate of viable starter counts.    

Volume 13, Issue 0 (11-2015)
Abstract



Volume 13, Issue 0 (11-2015)
Abstract

Structured polymer fibres with a diameter of about several micrometers to a few nanometres have attracted considerable attention in various scientific fields. Among the various methods applied to produce the fibre, electrospinning is proposed as one of the novel techniques. In this method, the non-woven structures are produced by applying electrical field to the polymer solution and due to the solvent evaporation. In the electrospraying method (as a branch of the electrospinning technique), the manufacturing process of the fibre production shifts to the production of capsules and thus conditions are provided for other varied applications of this technique. The electrospun fibres are applied in the processes such as filtration, tissue engineering, drug and nutraceutical targeted delivery as well as reinforcement of composite systems. In this comprehensive paper, relying on the experiences of the author, the introduction of electrospinning, the method of its implementation, and its potential applications in the food industry as well as the prospect of this technique in the industry will be discussed. Indeed, the entrances of this new approach to the food industry can induce significant alterations in this area of science.

Volume 13, Issue 0 (11-2015)
Abstract

The aim of this study was to investigat the effect of modifierd starch and maltodextrin as a wall material on the microencapsulation of ginger oil in green tea extract by spray drying method. Ginger oil was encapsulated with modiferd starch, maltodextrin, and mixture of these by ratio(2:1، 1:1، 1:2) .The mean droplet size  of emulsion and Encapsulation efficiency, oil surface, particle size and moisture of microcapsul was evaluated. The results showed that by reducing the Gum Arabic content and increasing Maltodextrin content, the emulsion  particle  size became larger. Encapsulation efficiency  increased and oil surface decreased by the decreas in particle  size  of emulsion  and powder. And the results indicated the lack of effect of rim material on the amount of moisture. A 2:1 and 1:1 blend of Gum Arabic:Maltodextrin offered a protection, better than gum Arabic and maltodextrin .

Volume 13, Issue 50 (5-2016)
Abstract


Saeed Rahmati, Abbas Ghaei, Ahmad Rezaeian,
Volume 14, Issue 2 (5-2014)
Abstract

Cold spray is a process which is used in coating industry and manufacturing of new parts. Experimental studies of this process are expensive and also very difficult due to high velocity of particles. Therefore, one effective method to study this process is its computer simulation. Previous works show that the Johnson-Cook hardening law has been usually used for simulation of this process. However, it is unanimously believed that this model is not able to reproduce the material behavior at extremely high strain rates commonly occurred in the cold spray process. Therefore, the simulation results are expected to improve if a suitable material model for extremely high strain rates is used. In this study, the PTW1 model was implemented in ABAQUS commercial finite element package. The cold spray process was then simulated for copper using both the PTW and Johnson-Cook hardening models. A comparison between the simulation and experimental results showed that the PTW model did improve the simulation results. The predicted flow stress by Johnson-Cook model was also shown to be not so sensitive to strain rate at extremely high strain rates.
Seyed Mostafa Hosseinalipour, Hadiseh Karimaei, Fathollah Ommi,
Volume 14, Issue 10 (1-2015)
Abstract

In this paper, 5 samples of one kind of swirl injector with tangential inlets, which has been designed and manufactured by using CNC, have been tested. Above injector has a spray cone in the shape of very thin layer because it is formed an air core in injector center. In fact, this is a one-fluid injector but its operation is two-phase. In order to detect acceptable injector among them, characterization tests have been done in the propulsion laboratory of Tarbiat Modarres University for all sample injectors. The methods of experimental characterization have been described in detail in current paper and also important parameters introduced. In these tests, injection uniformity, symmetry, mass flow rate versus pressure difference and some other parameter such as spray cone angle are investigated. Experimental results have been compared with design points. Finally, one injector has been selected as a suitable and nearer to theoretical design injector among them. The selected injector can be used for validation of numerical analysis results and also doing some complemental microscopic experiments. The results show good agreement between theoretical predictions and experimental results.
Seyed Hadi Poorhoseini, Mohammad Moghiman,
Volume 14, Issue 15 (3-2015)
Abstract

This is a study of the effect of synchronous combustion of gas-gasoil, achieved through the injection of gasoil droplets into natural gas flame, on the flame luminosity and radiative heat transfer. Droplets were injected by a single-hole micro-nozzle with a hole diameter of 100 μm and injection pressure of 9 bars. A photovoltaic cell was used to determine the luminous radiation and the total radiation of flame was measured by a thermopile. Also, the combination of chemiluminescence and IR photography of flame were employed to determine the qualitative distribution of soot particles in flame. The results show that the synchronous combustion of gas-gasoil raises the soot content of flame, leading to an increase of the luminosity and volume reaction of flame 38 and 2.5 times in comparison to the non-injection mode. Also, for the synchronous combustion of gasoil and gas with a mass fraction of 10%, the flame temperature changed only 95˚C, whereas the flame radiation rose as much as 52%. The improvement of flame radiation in synchronous combustion of gas-gasoil is due to the enhancement of flame emissivity coefficient in the IR region of electromagnetic wavelengths. Meanwhile, the injection of gasoil droplets increased the CO and NO pollutants by 4 ppm and 35 ppm in comparison to the non-injection mode; Due to the low mass flow rate of injection, however, the increase does not exceed the allowable limit for outlet pollution.
Mohammadmehdi Naghizadeh, Amirreza Ghahremani, Mohammad Hassan Saidi,
Volume 15, Issue 4 (6-2015)
Abstract

In this study, spray behavior of bio-ethanol as a regenerative fuel that reduces emissions such as NOX and CO is investigated in a combustion chamber and compared to its different blends with gasoline. For this purpose, microscopic and macroscopic spray characteristics and also evaporated fuel mass after the injection are modeled and investigated using Fire 2013. It is concluded by increasing bio-ethanol content in the fuel, evaporated fuel mass, spray cone angle, spray area and sauter mean diameter increases, however spray tip penetration remains roughly constant. Increase of injection pressure, decreases spray cone angle and suater mean diameter and increases evaporated fuel mass, spray area and spray tip penetration. If the energy content and time of injection of bio-ethanol and gasoline be equivalent the results vary significantly compared to previous cases. In this case bio-ethanol has a longer spray tip penetration and spray area, higher fuel mass evaporated and smaller spray cone angle and sauter mean diameter compared to gasoline. The increased spray tip penetration and spray area in this case may lead to piston impingement and bore wetting resulting increased hydrocarbon emissions and decreasing engine efficiency.

Volume 15, Issue 81 (11-2018)
Abstract

Powder production from vegetables is one of the preservative methods could be resulted to their diverse applications. The purpose of this study is to investigate the effect of carrier type on the characteristics of the celery powder produced by spray dryer. For this aim, Arabic Gum and maltodextrin (16.5-19.5 DE) were used in two concentrations of 0.0125%and 0.025% (w/w) and their effect on color parameters (a* ,b* ,L*), antioxidant activity, density and Tg piont were investigated. The results showed that the celery powder containing 0.0125% of Arabic Gum had the highest values for the parameters a*, b*, L*, antioxidant activity and density. The Higher level of green color and the antioxidant activity of celery powder containing 0.125% Arabic gum could be related to the type of binds involved in the reaction (hydrophobic and hydrophilic) between the Arabic gum and chlorophyll carrier, as well as the better preservation of phenolic and Flavonoid contents by Arabic gum carrier.

Volume 15, Issue 85 (3-2019)
Abstract

The purpose of this study was to produce the spray dried stevia extract and evaluation of Arabic gum concentration on production yield, physicochemical and morphological properties of stevia powder. the effect of sucrose replacement with stevia powders on physicochemical, texture and sensory properties of Aloe Vera jelly were investigated. The spray drying process was carried out at 10, 20 and 30% w/v concentrations. Then, 25, 50 and 75% of sucrose in the formulation of Aloe Vera jelly was replaced with 0.25, 0.50 and 0.75% of stevia powders. the maximum yield of powder(47.73%)has been obtained at 10:90 ratio. The amount of moisture, aw and hygroscopicity of powders decreased with increasing the carrier ratio.Other properties such as bulk, particle and true density, solubility and wettability of powders decreased with increasing the carrier ratio. These properties were varied in the range of 0.39-0.46 g/ml, 0.42-0.57g/ml, 1.42-1.55g/ml, 89.10-92.30%, and 15.39- 27.52 s. Also, flow ability behavior of samples improved by increasing the carrier ratios. According to the results of scanning electron microscopy, the increase of carrier concentration also led to the production of larger particles with wrinkled surface and irregular shapes. Evaluation of the physicochemical properties of the jelly samples revealed that by increasing the stevia concentration, the moisture content, synersis and acidity of samples increased, while the brix, gel strength and pH decreased. Treatments A, B and D(containing 0.25, 0.50 and 0.25% of G1 and G2 powder respectively)showed higher acceptability regarding sensory characteristics and did not show significant differences with the control sample

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