Maximum Allowable Depletion (MAD) by affecting on number of irrigation in growing season and irrigation use reduction can be used as a managerial tool to save water. The purpose of this study was to investigate the effect of MAD in irrigation interval, applied irrigation water, top and root growth of grass under subsurface drip irrigation system. Three irrigation treatments which were MAD equal to 40% (W1), 60% (W2), and 80% (W3) arranged in a randomized complete blocks statistical design with three replications in 2012 and 2013 in Isfahan University of Technology. The soil moisture was measured daily using Moisture Meter GMK-770S in the root zone depth of grass to manage irrigation. The apparent parameters and root parameters of grass were collected periodically. These parameters were analyzed by Duncan's multiple range test and the results showed that the irrigation treatments had no significant effect on the root growth parameters and top weight. In the depth of 0-13 cm the maximum root volumetric density and fresh and dry root weighted density were occurred in W1, W2 and W3 treatments, respectively. On the average, 80.14% of the mentioned parameters were in of 0-5 cm depth and 19.86% of them were in of 5-13 cm depth. The maximum (3.93 g/day) and minimum (3.21/day) dry biomass were observed in W1 and W3 treatments, respectively. Overall, the results indicated that although the increment of MAD to 80% in a clay-loam soil slightly decreased the shoot and root growth of mix sport grass under a subsurface drip irrigation system, it is a reasonable management solution with the aim of conserving water in the water shortage condition which had the least negative effect on apparent parameters of grass.

This paper develops a computational technique for finding the maximum allowable ‎load of mobile manipulators for a given trajectory. The maximum allowable loads ‎which can be achieved by a mobile manipulator during a given trajectory are limited ‎by the number of factors; probably the dynamic properties of mobile base and ‎mounted manipulator, their actuator limitations and additional constraints applied to ‎resolving the redundancy are the most important factors. To resolve extra D.O.F ‎introduced by the base mobility, additional constraint functions are proposed directly ‎in the task space of mobile manipulator. Finally, in two numerical examples involving ‎a two-link planar manipulator mounted on a differentially driven mobile base, ‎application of the method to determining maximum allowable load is verified. The ‎simulation results demonstrates the maximum allowable load on a desired trajectory ‎has not a unique value and directly depends on the additional constraint functions ‎which applies to resolve the motion redundancy‏.‏

Gorganrood river is one of the three main rivers in Golestan province have a basic role in Golestan water supply. To study Gorganrood water quality and estimating maximum allowable pollutant, water quality data was used from 8 stations. Purification of this river has been studied by two methods: statistical and experimental methods. Each method showed that the Gorganrood river at present condition has no problem for purification. Average measured BOD in this river on Tamar-Ghareghoozy station was 9.7 mg/Lit and maximum observed BOD on up stream of Voshmgir dam was, some times larger than allowable amount but on the down stream there wasnt any problem. Average BOD in Gorganrood varies from 1.7 mg/Lit on Gonbad entrance station to 2.48 mg/Lit on Tamar-Ghareghoozy and Agh ghala entrance stations. This river has no main problem to fall pollutants. 

In this paper, a general formula for finding the Maximum Allowable Dynamic Load (MADL) of geometrically nonlinear flexible link manipulators is presented. The dynamic model for links in most mechanisms is often based on the small deflection theory but for applications like lightweight links, high-precision elements or high speed it is necessary to capture the deflection caused by nonlinear terms. First, the equations of motion are derived; taking into account the nonlinear strain displacement relationship using Finite Element Method (FEM) approaches. The maximum allowable loads that can be achieved by a mobile manipulator during a given trajectory are limited by a number of factors. Therefore, a method for determination of the dynamic load carrying capacity for a given trajectory is explained, subject to the accuracy, actuator and amplitude of residual vibration constraints and by imposing a maximum stress limitation as a new constraint. In order to verify the effectiveness of the presented algorithm, two simulation studies considering a flexible two-link planar manipulator mounted on a mobile base are presented and the results are discussed. The simulation results indicate that the effect of introducing geometric elastic nonlinearities and inertia nonlinearities on the maximum allowable loads of a manipulator.

ABSTRACTIntroductionSoil and water salinization is a worldwide problem, especially in irrigated areas, causing decrease in crop yield and the continuous loss of arable fields. Halophytes are the natural genetic source of salt tolerance traits and can be used for revegetation and remediation of salt-affected lands, and also as an alternative crop or biofuel. Due to the limited quality of water resources in the country and considering that the major regions of Iran's area are considered to be arid and semi-arid, it is important to cultivate plants with high tolerance to environmental stresses such as drought and salinity. The quinoa (Chenopodium quinoa Willd.) plant is important because of its ability to be cultivated in saline areas and irrigated with saline water. According to previous research, quinoa is an optional halophyte, and its irrigation is possible up to sea level salinity. Quinoa (Chenopodium quinoa Willd.) is one of the plants that has outstanding economic and agronomic advantages among the crops; it is particularly important in terms of forage production. There is no reliable and accurate information about the amount of water consumption by this plant in Iran. Considering the climatic characteristics and water shortages in the country, as well as the development plan for the cultivation of this plant due to its high nutritional value, attention to its water requirement becomes more important. For this reason, the importance of precise irrigation design and planning is needed in order to improve the performance of irrigation water usage in this region.Materials and MethodsThis research is conducted aim to determine the effects of different levels of moisture and salinity on the yield, some morphological traits, and some yield components of quinoa (Chenopodium quinoa Willd.) in field conditions during two growing seasons (2020-2022) in Yazd, Iran. The experiments were carried out in a factorial experiment in a randomized complete block design, which included two irrigation water salinity levels of 5 and 12 dS/m and four irrigation levels of 60, 80, 100, and 120% to provide the amount of allowable moisture depletion (MAD equal to 50%) in the root zone, in three replications. Experimental plots were designed with dimensions of 5×7 meters. Applying the amount of irrigation was done according to the determination of the field capacity levels and the permanent wilting point moisture measured (using a pressure plate device) before the start of the experiments. In this regard, according to this information, on the day of irrigation, the amount of soil moisture in each of the plots was measured at the root zone, and based on the treatments, the amount of water required was calculated, and irrigation was applied to the determined moisture level. Irrigation was carried out in the form of flooding, and the volume of irrigation water for each treatment was controlled by the volume contour and applied separately at each interval. At the end of the experiment, quinoa was harvested in a one-square-meter grid, and then plant height, panicle length and width, and stem diameter were measured. After the plant's drying, the weight of the seeds and the weight of the whole shoot were measured in different treatments.Results and DiscussionThe results showed that the different levels of salinity and soil moisture cause significant changes in biomass yield, seed yield, and harvest index. Also, the results indicated that changes in salinity levels and moisture levels caused significant differences in plant height, stem diameter and panicle length, panicle width, and 1000-seed weight (P<0.01), but their interaction was not significant. For two levels of salinity, the maximum biomass (9.28 tons/ha) was observed by supplying 100% of the depleted soil moisture based on MAD = 50%. According to the yield-water use function, the maximum seed yield for 5 and 12 dS/m irrigation water salinity was observed in treatments that supplied 115% and more than 120% of depleted soil moisture based on MAD = 50%, respectively. With the increase in salinity stress from 5 to 12 dS/m, biomass weight decreased by 23% and seed yield decreased by 17%. Based on the results, the average volume of applied water in fall cultivated quinoa under the 5 dS/m irrigation water salinity was 4900 m3/ha during the growth season (90 days).ConclusionIn the autumn planting of the Titicaca variety of quinoa, with a planting period of about 90 days in arid and semi-arid regions like Yazd, water consumption is about 450 to 550 mm. But in conditions of moisture deficiency, it is possible to grow this plant. Because it has a lower yield reduction slope than other plants under drought and salt stress conditions. Furthermore, the results indicated that the salinity of the soil profile increased in deficit irrigation conditions (60% and 80% of depleted soil moisture based on MAD = 50%) due to the lack of leaching requirements.

In this paper a general formulation for finding the maximum allowable dynamic load (MADL) of flexible link mobile manipulators is presented. The main constraints used for the algorithm presented are the actuator torque capacity and the limited error bound for the end-effectors during motion on the given trajectory. The precision constraint is taken into account with two boundary lines in plane which are equally offset due to the given end-effectors trajectory, while a speed-torque characteristics curve of a typical DC motor is used for applying the actuator constraint. Finite element method (FEM) is utilized for deriving the kinematic and dynamic equations which considers the full nonlinear dynamic of mobile manipulator. In order to verify the effectiveness of the presented algorithm, two simulation studies considering a flexible two-link planar manipulator mounted on a mobile base are presented and the results are discussed.

Hybrid layered manufacturing is one of the key methods among rapid manufacturing techniques in which a layer of molten metal is deposited on the substrate and desired geometry is completed by stacking the layers. Low cost, high rates of deposition and great applicability are some of the characteristics of hybrid layered manufacturing. Welding and face milling are the two steps of the process. In welding phase, metal is built up by weld lines to cover a given surface and in milling phase weld beads are truncated to achieve a flat and integrated layer. The focus in this article is to optimize two contradictory objectives, namely reduction in machining volume and increase in deposition rate. Thus, the first task is to formulate the bead model considering the metal build-up effect. Then, the situation needed for achieving quasi-flat layers in welding phase is studied and the unified model is extracted. Moreover, GA is used to find optimum values for the proposed model based on heat and process constraints. Finally the model is verified and conclusions are drawn. This article presents a new criterion by defining the heat constraint for the multi-objective function. Results show that for the 0.8 mm wire ER70S6, optimum values are 8.6 m/min for wire speed and 0.6 m/min for torch speed that yield a deposition rate of 4224 mm3/min without violating heat constraint.

Introduction: Water is one of the most important factors limiting plant growth and agricultural productivity in many areas of the world. Decreasing water losses and irrigation times are one of the basic countermeasures for agriculture development and minimizing the stress to plants. Correct management and applying improved techniques for saving and conserving the humidity of soil and increasing the soil water holding capacity is among the activities for productivity increasing and consequently exploiting limited water resources. New method in science of soil and water is using super absorbent materials as reservoirs and prevention from water wastage and increase of irrigation efficiency. Materials and Methods: In order to evaluate the application effects of different levels of superabsorbent polymer on growth of strawberry plants under drought stress condition, a research was conducted in the Mazandaran province in loamy soil during 2010. Experiment was carried out as factorial based on randomized complete block design with three replications and three plants for each replication. Dryness stress treatments (30%, 50% and 70% of Maximum allowable depletion of soil moisture; MAD) and superabsorbent polymer (0, 0. 25, 0. 5, 0. 75 and 1 % of soil weight) were allocated to main and sub-plots, respectively. In this research the superabsorbent polymer TawaratA200 is used that is produced by the research center of petrochemical and polymer of Iran. Before planting, super absorbent polymer was added to the soil of pots in deepness of root development. For stress application, the pots were weighted every day. During the experiment, the physicomorpholigic characteristics such as number and length of stolones, number of leaves, plant length, biomass, fresh and dry weight, fruit diameter, number and weight of fruit were estimated. Results and Discussion: The results showed, superabsorbent and drought stress and their interaction effects effected on all factors. In vegetative characteristics, number and length of stolones in treatment of 1% superabsorbent and 30%of MAD (maximum allowable depletion) has been maximum. By increasing stress, number and length of stolones declined. The lowest amount was obtained in the treatment of non-superabsorbent and 70% of MAD. With increasing stress, the number of leaves decreased and with increased superabsorbent, leaf number was increased. Strawberry leaves in treatment of one percent superabsorbent and 30%of MAD has a maximum value and in treatment of non-absorbent and 70% of MAD was minimal. Root length, fresh and dry weight were affected by the water stress. 70% of MAD and 30% of MAD has been the minimum and maximum amount, respectively. The plant length, biomass, fresh and dry weight, by reducing stress and increasing superabsorbent has increased and maximum values were obtained in the treatment of 30%of MAD and one percent of superabsorbent. In reproductive characteristics, fruit diameter reduction, occurred with increase stress. Fruit diameter was increased by adding superabsorbent and reducing stress. In the treatment of 1% superabsorbent and 30%MAD the maximum diameter of the fruit was obtained. Increased water stress has been causes weight reduction. In treatment 30%of MAD, the weight of fruit was obtained 4. 17 g, with the increase of water stress, the fruit weight was reduced to 1. 99 g. The use of superabsorbent increases the yield. With an increase of 0. 25%superabsorbent, fruit weight was increased from 4. 17 to 8. 14 g. In the interaction of stress and superabsorbent, the maximum weight of the fruit with 18. 99 g was obtained in treatment of 1% superabsorbent and 30% MAD. the maximum number of fruits was obtained, in treatment with 1% superabsorbent and 30% MAD with the number of 19. 67. Conclusion: Super absorbent polymer plays an important role in enhancement of absorption capacity and retention of water in soil, fighting against water shortage and decreasing harmful effects of drought stress. The above mentioned rates of polymer have the best effect to all characteristics of strawberry in all levels of water stress treatment. The findings strongly suggest that the irrigation period of strawberry cultivation can be increased by application of polymer.

Introduction: Nowadays, the decrease of water resources and increasing salinity of irrigation water are evident in most parts of Iran. Increased salinity of irrigation water can impair plant metabolism, decrease biomass and stem length. On the other hand, water stress decreases root length and weight and crop yield. One way to reduce the negative effects of moisture stress is management of irrigation time. This can be investigated by changing the percentage of moisture permitted depletion and selecting the one with the lowest yield depletion. On the other hand, the amount of damage to the crop can be reduced by examining different amounts of water salinity and its effect on crop yield. Therefore, in this study, the effects of different amounts of irrigation water salinity and irrigation time management on tomato yield under greenhouse conditions were investigated. Materials and Methods: This study was carried out in greenhouse (No. 2) of Faculty of Agriculture and Natural Resources of University of Mohaghegh Ardabili. In this research, the effect of different values of salinity (in different irrigation times) on root characteristics and yield of tomato (Saint Pierre cultivar) was investigated. The experimental design used in this research was a factorial experiment in a completely randomized block design with four replications. The applied treatments included salinity of irrigation water (four levels: S1=1. 5ds/m, S2=2. 5ds/m, S3=4ds/m and S4=7ds/m) and irrigation time management stress (in three levels, irrigation at 40, 50 and 65% field capacity, respectively, I1, I2, I3). The pots used in this study were incomplete cones with a height of 27 cm, a span diameter of 26 cm and a bottom diameter of 19 cm. In this study, indirect method (transplanting) was used for cultivating tomato. After cultivating the transplants in prepared pots, they were irrigated with pure water for two months to stabilize the transplants in order to avoid any stress effect on the transplants. The moisture meter (Model: PMS-714) was also used to measure daily soil moisture of the pots. Statistical analysis was performed by MSTATC software. The important characteristics investigated in this study were root length, root weight (dry and wet), root diameter and volume, plant yield, water drainage, evapotranspiration and water use efficiency. Results and Discussion: According to the results of this study, salinity values of irrigation water had a significant effect at 1% level on fresh and dry root weight, root diameter and volume, total evapotranspiration, total water use, total water drainage output, crop yield and the number of blooms. On the other hand, irrigation water salinity had no significant effect on the number of unripe fruits at 5% confidence level. For example, the highest fresh and dry weight of roots were 26. 17 and 6. 3 g for S2 treatment, respectively. However, the difference in root weight values for S2 and S1 treatments (Mean equal to 27. 5%) was not significant. Also, with increasing salinity of irrigation water above 2. 5 dS/m, root weight (dry and fresh) decreased significantly (at 1% level). The reason for the decrease in root weight at high level of salt concentrations can be due to the accumulation of salt (including potassium, sodium, etc. ) in various organs of the plant including the root. On the other hand, the results showed that the effect of irrigation time management was significant only on root diameter and weight of ripe fruit at 5% and 1%, respectively. According to the results of this study, irrigation can be achieved with 50% moisture allowable depletion instead of 40% moisture permitted depletion without significant change in the weight of ripe tomato fruit. This can certainly cause saving of irrigation water that can be very effective in the current condition of Iran and lack of water resources. In this study, the relationship between evapotranspiration and crop yield and the relationship between these parameters, were investigated. Results showed that, tomato yield coefficient of response to moisture stress (Ky) varied from 0. 4 to 1. 20. Also the average response coefficient of tomato to water stress was 1. 12. This value was close to the mean Ky provided by the FAO (Ky = 1. 05). The slight increase in Ky value obtained from this study is probably due to the salinity stress applied to the tomato plant. Conclusion: This study was conducted to investigate the effect of salinity stress on yield and root characteristics of tomato under irrigation time management and greenhouse conditions. The results showed that the effect of irrigation salinity was significant on yield, yield components and root characteristics (e. g., root weight, diameter and volume, yield, evapotranspiration and drainage output). On the other hand, moisture stress induced by irrigation time variation had no significant effect on yield, yield components and root characteristics of tomato except in two cases. This study indicated that the effect of salinity irrigation water is more effective than water stress on reduction yield. Also, according to the results of this study, the use of 2. 5 dS/m irrigation water salinity instead of 1. 5 dS/m in most cases had no significant effect on yield reduction but may also increase it. The results of this study show that under current conditions of Iran (increasing quantitative and qualitative shortage of water resources) it is possible to use lower quality waters such as treated wastewater and agricultural wastewater (with management of salinity and leaching) to achieve the acceptable yields for crops.

This study aimed to determine the crop coefficient of sugar beet using canopy cover extracted from digital images under different irrigation managements. The crop coefficient and canopy cover were directly measured by water balance and image processing methods, respectively, in 10 days intervals during the growing season. The crop coefficient of sugar beet in three irrigation managements with maximum allowable depletion (MAD) of 40%, 60%, and 80%, was estimated using its regression equation with canopy cover. This was modeled for potential conditions and then validated by using the average measurements in two years. The findings showed that the estimated crop coefficients were in good agreement with the observations in irrigation managements that had MAD of 40% and 60%. The coefficient of determination (R2), normalized Root Mean Square Error (nRMSE), and model efficiency (EF) were 0. 95, 0. 11 and 0. 95, for 40% MAD, 0. 9, 0. 13 and 0. 85 for 60% MAD, respectively. The results illustrate that the crop coefficient of sugar beet, within the moisture range between field capacity to a MAD of 60%, can be reliably estimated by this approach. The values of determination coefficient (R2), normalized Root Mean Square Error (nRMSE) and model efficiency (EF) decreased to 0. 49, 0. 37 and 0. 63, respectively, for 80% MAD, indicating poor performance of the model under severe drought stress conditions. The proposed method has some advantages including easy and fast data collection, greater accuracy and lower cost, the ability to provide the desired number of images, and no need for meteorological data. Therefore, this can be applied to study the plant growth and crop coefficient variations during the growth period.