Original Article
Abstract
Sugarcane, which has high water requirements, is grown in Khuzestan province (Iran). Climate and optimizing the use of water is very important to sustainable cultivation of sugarcane. Studies of water requirements for sugar cane in Khuzestan show that in parts of sugarcane agro-industry, the water applied ...
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Sugarcane, which has high water requirements, is grown in Khuzestan province (Iran). Climate and optimizing the use of water is very important to sustainable cultivation of sugarcane. Studies of water requirements for sugar cane in Khuzestan show that in parts of sugarcane agro-industry, the water applied is more than the actual water requirement of the plant. The present study was conducted to predict the long-term effects of irrigation system and drainage in the Imam Khomeini sugarcane agro-industry on soil salinity, drainage depth, water table and irrigation sufficiency and efficiency using the SaltMod model. The model varied the irrigation depth and drainage control factor (Frd) to decrease subsurface drainage depth and salinity of irrigation water. Model output was calibrated using field data. The model predictions showed that a drainage control factor of more than 0.25 without a decrease in irrigation water caused the water table to rise. A 20% decrease in irrigation water and an assumed drainage control factor of up to 0.5, there was no change in soil salinity or water table depth. Drainage outflow depth of about 2.07 m decreased to 1.26 m during irrigation. The SaltMod model predicted that increasing the subsurface drainage depth to over 1.5 m would not improve yield or change soil salinity. If the irrigation water had salinity levels of >1.7 dS/m, soil salinity in the root zone will be >3 dS/m.
Original Article
Abstract
Analysis of seepage from an earth dam helps determine water loss and is very important for analysis of the stability of these structures. The present study examined the effect of material hydraulic properties and drawdown rate and ratio on the position and form of the phreatic line, pore water pressure ...
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Analysis of seepage from an earth dam helps determine water loss and is very important for analysis of the stability of these structures. The present study examined the effect of material hydraulic properties and drawdown rate and ratio on the position and form of the phreatic line, pore water pressure and the stability of the shoulder of a homogeneous earth dam. For this purpose, the materials used in the homogeneous earth dam were selected from the unsaturated soil hydraulic database. Seepage and stability analysis were performed using the Geostudio sub-programs of seep/w and slope/w (based on the finite element and limit equilibrium methods, respectively). Seepage and stability analysis were performed in steady and transient states by applying four different drawdown rates. The results showed that the lack of significant differences in safety factors means that application of constant or function conductivity does not affect downstream slope stability of a homogeneous earth dam and the phreatic line was independent of conductivity. Results from the numerical model shows the noticeable impact of the soil water characteristic curve and slope () on the rate of drainage and subsequent pore water pressure and shear strength. The safety factors and critical states changed as the degree of saturation decreased or increased. With rapid drawdown of the reservoir at constant volumetric water content, the state of the upstream shoulder became critical when the drawdown ratio (L/H) reached about 0.5. As the water content of the unsaturated zone and the capacity of drainage decreased, stability reached the minimum FOS at a reservoir water level of about 2/3 of the total drawdown height.
Original Article
Abstract
This study prepared new edible composite film by blending kefiran with whey protein. The film-forming solutions used different ratios of kefiran to whey protein (70/30, 50/50, 30/70, 10/90) and were cast at room temperature. The effects of the addition of whey protein on the physical, mechanical and ...
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This study prepared new edible composite film by blending kefiran with whey protein. The film-forming solutions used different ratios of kefiran to whey protein (70/30, 50/50, 30/70, 10/90) and were cast at room temperature. The effects of the addition of whey protein on the physical, mechanical and water-vapor permeability (WVP) properties of the film were investigated. It was found that an increase in whey protein content from 0% to 50% (v/v) decreased WVP; however, further addition of whey protein increased WVP. This increase in whey protein content increased the tensile strength and extensibility of the composite film; however, these mechanical properties decreased at higher whey protein contents. Electron scanning micrography of the composite film showed it was homogeneous with no sign of phase separation between components. It was observed that these two film-forming components were compatible and that an interaction existed between them.
Original Article
Abstract
New edible composite films formed from salep (Orchis mascula) and 10%, 20%, and 30% (w/w) oleic acid were prepared by emulsification with the aim of improving the water vapor barrier and mechanical properties of the film. As oleic acid concentration increased up to 30% (w/w), oxygen permeability (27%), ...
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New edible composite films formed from salep (Orchis mascula) and 10%, 20%, and 30% (w/w) oleic acid were prepared by emulsification with the aim of improving the water vapor barrier and mechanical properties of the film. As oleic acid concentration increased up to 30% (w/w), oxygen permeability (27%), elongation at break (86%) and thickness (2%) of salep films increased significantly and the tensile strength (37%), solubility (39%), transparency (13%) and water vapor permeability (54%) decreased significantly (P<0.05). Increasing the oleic acid concentration produced a slight yellowish color in the salep film, but it was still transparent in appearance. It was found that oleic acid can be incorporated into the film and might be applicable for food packaging applications that require high water vapor permeability.
Original Article
Abstract
Fruit yoghurt is frequently made with fermented milk products; however, the use of fruit and its products may cause changes in the viscoelastic properties, syneresis and sensory properties of fruit yoghurt. One approach to improve these properties in fruit yoghurt is the use of thickening agents. This ...
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Fruit yoghurt is frequently made with fermented milk products; however, the use of fruit and its products may cause changes in the viscoelastic properties, syneresis and sensory properties of fruit yoghurt. One approach to improve these properties in fruit yoghurt is the use of thickening agents. This study investigated the effect of carboxymethyl cellulose and guar thickening agents on the properties of set fruit yogurt. Syneresis decreased and water holding capacity increased as carboxymethyl cellulose and guar increased up to 0.2% and 0.06%, respectively. The type and content of hydrocolloids at all concentrations had no significant effect (P< 0.05) on mold and yeast growth. Increasing the concentration of these two thickening agents up to critical levels produced no negative effects on sensorial properties such as color, coarseness, cohesiveness and adhesiveness. Different mechanisms effected the formation of yogurt structure. No synergistic effect was observed on improvement of the gelled structure and physicochemical properties of the yoghurt.
Original Article
Abstract
A semi-automatic 9-row transplanter for bare root seedlings has recently been developed at the Isfahan Center for Agricultural Research that plants 80 seedlings/m2 using 9 operators at a capacity of 0.3 ha/d (8 h). Separating a single seedling from a bunch and dropping it into a distributer cell by hand ...
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A semi-automatic 9-row transplanter for bare root seedlings has recently been developed at the Isfahan Center for Agricultural Research that plants 80 seedlings/m2 using 9 operators at a capacity of 0.3 ha/d (8 h). Separating a single seedling from a bunch and dropping it into a distributer cell by hand takes 1 s on average. At a density of 700-800 thousand/ha, the travel speed should not exceed 6-8 cm/s, which is a limitation to improving machine field capacity. Increasing the speed to >8 cm/s to improve machine efficiency can only be achieved if more than one seedling is allocated to each cell. A randomized complete block design was used to drop 1, 2 and 3 seedlings per cell at speeds of 8, 12 and 16 cm/s, respectively, with manual transplanting as the control treatment. The treatments were compared for stand establishment, crop yield components, machine field capacity and economic benefit. The results showed that dropping two seedlings per cell and increasing speed 50% and produced a about a 24% increase in stand establishment and bulb yield compared to the single seedling/cell treatment. Three seedlings per cell produced a 53% increase in stand establishment but only about 17% improvement in bulb yield. This can be attributed to the smaller sizes and weights of the individual bulbs. The number of established seedlings in the 1 seedling per cell pattern produced results that were similar to the manual single transplanting treatment. Economic appraisal of treatments revealed that replacing 1 seedling per cell with 2 and 3 seedlings per cell produced a net increase in profits of 33% and 12%, respectively. The 2 and 3 seedlings per cell methods increased machine field capacity 50% and 100%, respectively. It can be concluded that, from the economic standpoint, 2 seedlings per cell is preferred over the 3 seedling per cell treatment; however when planting must be completed rapidly, the 3 seedling per cell treatment is also economically justified.
Original Article
Abstract
In this research, unpeeled and peeled fruit from the Persian lilac were prepared and the flow properties, mean geometric diameter, sphericity coefficient, bulk density, coefficient of static friction and coefficient of internal static friction were determined. The flow patterns and discharge flow ...
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In this research, unpeeled and peeled fruit from the Persian lilac were prepared and the flow properties, mean geometric diameter, sphericity coefficient, bulk density, coefficient of static friction and coefficient of internal static friction were determined. The flow patterns and discharge flow rates from a cubic hopper was investigated. The results indicate that the minimum discharge diameter for peeled fruit was 4.6 cm and for unpeeled was 6.3 cm. A comparison of discharge through a 5.5 cm diameter discharge outlet showed that the flow for the peeled and unpeeled fruits were 586 and 554 cm3/s, respectively. Three flow patterns were distinguished within the hopper: the increasing zone, the decreasing zone and the re-increasing zone. Exponential and two third-degree polynomial models were chosen and presented to predict the instantaneous horizontal and vertical positions and speed of the fruits within the hopper. The discharge rate was modeled using the Beverloo and Gregory models. Both models were well-fitted to the experimental data; however the Beverloo model resulted in a higher accuracy (R2 = 0.97).
Original Article
Abstract
This study evaluated direct drilling planters used for wheat cultivation in Khorasan-e Razavi province. A randomized complete block design with three replications was used. The treatments were direct drilling of wheat plants into wheat residue using the following direct planters: (1) Sfoggia (13-25), ...
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This study evaluated direct drilling planters used for wheat cultivation in Khorasan-e Razavi province. A randomized complete block design with three replications was used. The treatments were direct drilling of wheat plants into wheat residue using the following direct planters: (1) Sfoggia (13-25), (2) Baldan (SPD3000), (3) Tondar (SPD 2500), (4) Semeato (SHM 11/13). The parameters measured were uniformity of seed depth, planter field capacity, seed germination, mechanical damage to seed, yield, number of spikes per m2, number of grains per spike, 1000 seed weight and harvest index. The results showed that planter type was significant at the 1% probability level for uniformity of seed depth, planter field capacity and harvest index and at the 5% probability level for yield, number of spikes per m2, number of grains per spike and seed germination. Results showed that the Sfoggia planter performed best for uniformity of seed depth and number of spikes per m2. The Sfoggia and Tondar planters performed best for seed germination, yield, and number of grains per spike and harvest index.
