In this research which is based on synoptic Climatology procedures including synoptic maps interpretation and statistical analysis, the air masses influencing Iran, in three stations: Tehran, Shiraz and Kermanshah based on the temperature and dew point, daily upper air data surface, 850,700,500 hecopascal for the years 1981-90 were studied.Also in this research in order to identify the air masses, based on the conservation of air mass properties law, the following parameters: potential temperature, wet bulb potential temperature and mixing ration were selected, and Calculated. statistical analyses such as principal component and cluster analysis were done. Given all the information above the results are as follow:For Tehran station 4 Shiraz 3 and Kermanshah 3 factors were extracted, and based on these factors hierarchical cluster analysis for aggregate days was applied and then mean analysis for all data was done. With comparing the average value of all parameters in each groups and comparing them with the data of Aswan, Ashkhabad and Mediterranean air mass properties, these air masses tmA.,cA,cP,mT,cT and med. were determined.And then based on the data of potential temperature and mixing ratio of 500 hectopascal index days was extracted and tephigrams for these days were prepared and their synoptic maps were studied.

Introduction: Stereo vision is an approach to 3D information from multiple 2D views of a scene. The 3D information can be extracted from a pair image, as known stereo pair by estimating the relative depth of points in the scene. Soil aggregate size distribution is one of the most important issues in the agriculture sector which highly affects energy consumed for preparing the field before planting. Mean weight diameter of clods is a standard metric for determining clod (big aggregates) size. Conventional methods are based on sieving soil samples to calculate the MWD. However, they are faced with several challenges in larger scales and practical applications. Furthermore, due to inherent limitations of soil environment and also being a tedious work, traditional methods would beuse to estimate the metric higher or lower than actual value. As new methods, researchers are using computer vision techniques as virtual sieve so that the size of clods can be determined via processing digital images which have been taken from soil surface. Although, image-based methods have solved many of previous problems, their accuracy is not so high due to the complexity of soil environment and overlapping colds, and needs to be improved. In order to overcome the mentioned challenges, in the current study stereo vision method was developed so that it is possible to extract the third dimension information as height of clods which helps us to categorize clods into their own class. Materials and Methods: In this study, the W3-Fujifilm stereo camera equipped with two 10-megapixel CCD sensors for both left and right lenses, and baseline spacing of 7. 5 cm was used. The distance between the camera lens and the ground was also set to 60 cm. In order to get three components of soil clods including (x, y, z), point cloud was investigated. For this, local features were extracted using a SIFT feature detector. The SIFT algorithm is robust against scale, rotation and illumination changes, so that these specifications have made it as a strong tool in the field of stereo vision. Then, the extracted features (keypoints) were matched between two stereo pair images by means of Brute Force algorithm and the location of all corresponding points were determined and point cloud was obtained. At the final stage, three features including length, width and height of all six classes of soil clods were entered into a linear classifier entitled discriminant analysis. This classifier as a linear separator classified these six classes based on appropriate functions in a 5 dimensional space. Results and Discussion: Results of classification model showed that the height (thickness) of clods have more distinguishing different soil clods. The reason for this refers to the event of overlapping, because most of clods were touched each other after sieving. Consequently, the length and width of clods had not significant effect in soil aggregates classification. In order to analysis the result of soil aggregate classification, confusion matrix was calculated and the overall classification accuracy was achieved 83. 7%. The lowest and highest accuracy were obtained for class 1 (the littlest class) and class 6 (the biggest class), respectively due to their low and high height from the soil surface. Conclusions: In this research, the basic geometrical features including length, width and height were extracted from stereo pair digital images via stereo vision techniques to classify six classes of soil clods. This aim was reached by 3-D reconstruction of image data, so that the height of each image as the third component of (x, y, z) was obtained as well as the length and width. The results of classification indicated that the stereo vision technique had the satisfactory performance in determining the aggregate size distribution which is one of the most important indices for tilled soil quality.

Reduction of tillage operations in conventional systems and its replacement with a reduced tillage and conservation systems is recommended in order to sustainable production in agriculture and preservation of soil and water resources. In this research, the effect of applying three types of conventional tillage machines with different geometry that have less rigidity of soil tillage than conventional tillage machines (Chisel packer, combined tiller and offset disc) on the performance parameters of tillage including Specific draft, specific tillage energy, and weighted average diameter of clods, roughness of soil surface and percent of crop residue on the soil surface. Tillage depth is fixed in 20 cm, forward speed was in three levels (2. 5, 4. 5 and 6 km/h) and tillage machinery type was in three levels. Double Split plot in Randomized Complete Block Design used in the study in which tillage depth (main factor), forward speed (secondary factor) and the tiller type (sub-secondary factor) were the independent variables. The results showed that the amount of residues remaining on the soil surface after soil tillage was negatively correlated with not only special draft but also with other indices (weighted average diameter of clods and roughness of soil surface), and crop residue after soil tillage was applied as a criterion for comparing soil tillage machinery. The results of the comparison of the ranking of treatments based on two methods (amount of crop residues after soil tillage and the Component Analysis method) showed that the combined tiller and the offset disc at low velocity and Chisel packer at high velocity is recommended for conservation systems of tillage.

Separating clods from potato tubers is one of the most challenging jobs in a potato harvester. In this study, an acoustic-based intelligent system was developed for high speed discriminating between potato tubers and clods. About 500kg mixture of potato tubers and clods were put on the belt conveyer and impacted on a steel plate in four different velocities. The resulting acoustic signals were recorded, processed and potential features were extracted from the analysis of sound signals in both time and frequency domains. A multilayer perceptron (MLP) neural network with a back propagation algorithm was used for pattern recognition. Altogether, 17 potential discriminating features were selected and fed as input vector to artificial neural network (ANN) models. Optimal network was selected based on mean square error, correct detection rate and correlation coefficient. At the velocity of 1 ms-1 of the belt, detection accuracy of the presented system was about 97.3% and 97.6% for potato and clod, respectively. Detection accuracy decreased by increasing belt velocity. A potato harvester by using this system can perform at capacity of 20 ton hr-1 by accuracy of about 97%.

Introduction Tillage is a main operation for seedbed preparation and is one of the major items of energy and cost expenditure in crop production. In the conventional rotary tillers, using the L-shape blades has numerous problems such as severe vibrational problems, weeds wrapping around the blades, and lower performance due to the limited power of such small tillers. Therefore in order to overcome the addressed problems, design, fabrication and evaluation of a new rototiller adapted for small farms and gardens were considered in this research. Materials and Methods To start the design, the power requirement was estimated using a semi-theoretical model for the given working depth, working width, forward and rotational speed of the machine. Then a suitable engine was chosen based on the estimated power. The estimated power was 3. 4 kW (4. 5 hp); therefore, according to the available engines in the market for single cylinder gasoline engines, a Kato engine with 5. 5 hp power and maximum speed of 3600 rpm was chosen. By reducing the rotational speed of the engine in three stages, rotational speed of the rotor was obtained in the range of 140-260 rpm. To transmit the power from the engine to the rotary axis, first, a pulley and belt mechanism (two V-shaped belt, type B) and then two chain mechanisms (roller chains 40 and 60) were used. Rotary axis with the diameter of 2. 5 cm was made from steel E295. The fabricated rototiller has a working width of 60 cm, working depth of 7 cm, rotational speed between 140-260 rpm, forward speed equal to the operator’ s translational speed, and maximum power equal to 5. 5 hp. The maximum force exerted on each of the blades was calculated equal to 84. 10 kgf (824. 73 N) using the theoretical approach proposed by Bernacki (1972). In the next step, numerical simulation of blades, flanges and rotating shaft for stress and strain analysis was performed using the Ansys software. Farm experiments were carried out as split plots in citrus gardens based on randomized complete block design with three replications. The soil moisture content as the main plot varied in two levels (13. 5-21. 9 and 21. 9-30. 3 percent based on dry weight) and the rotational speed of blades as subplots varied in three levels (140-170, 170-200 and 200-230 rpm). The measured parameters consisted of clod mean weight diameter, soil relent percentage, soil bulk density and specific fuel consumption. To determine the diameter of aggregates, a set of standard sieves with the diameter ranging from 0. 5 to 8 mm were used. Then a laboratory shaker was used to sift the samples. Each sample was shaken for 30 sec. To determine the fuel consumption during the experiments, the filled fuel tank method was used. Data analyses including analysis of variance (Anova), mean comparisons and interaction between the parameters were performed using the SPSS 16 software. Results and Discussion The numerical stress analysis of the flange showed that the maximum van-Mises stress occurred in the position of the blade-flange connections, with a magnitude of 52. 98 MPa for the given working conditions, including soil engineering properties, working depth and other important parameters. The experimental results obtained in this study indicated that influence of soil moisture and rotational speed of blades on the clod mean weight diameter, soil relent percentage and specific fuel consumption were significant (P<0. 01). The clod mean weight diameter was measured equal to 8 mm at high rotational speed (200-230 rpm) and high soil moisture content (21. 9%-30. 3%) and equal to 15 mm at low rotational speed (140-170 rpm) and low soil moisture content (13. 5%-21. 9%). The maximum soil relent percentage was obtained equal to 97% at high rotational speed (200-230 rpm) and high soil moisture content (21. 9%-30. 3%). Regarding the results obtained in this study, the specific fuel consumption increased first in a light slop, then in a steep rise with increasing the blades rotational speed. The reason can be the higher relent percent of the soil at higher rotational speeds and higher moisture contents, albeit at the examined range of 21. 9-30. 3. The specific fuel consumption was maximum at higher soil moisture content, i. e., 30 %. The results indicated that the blades rotational speed and soil moisture content had no significant effect on the field efficiency of the examined rototiller. Reduction of the rotational speed of the rototiller from high-to-moderate speeds yields decreasing the fuel consumption of 17 liter/ha, which could be significant in a wide scale soil tillage operations. As a general result, reduction of the rotational speed has some considerable advantages such as reducing the power requirements, reducing the blade wearing and maintaining the soil structure. Conclusion The stress analysis of the fabricated machine together with the experimental and field measurements indicated that the new proposed and fabricated blades were a suitable choice for construction of small rototillers. The fabricated machine with the new blades showed some additional advantages including less specific energy consumption, less weeds wrapping around the blades, and less vibrational problems.

Background: The aim of radiation therapy is to deliver a precisely measured dose of irradiation to a defended tumor volume. Simulation has been used instances to document the configuration of the portal and target volume to be irradiated accurately. Unfortunately, there is non-Conventional simulation in most of cancer centers in Iran. There fore in this study, it was tried to estimate pelvic inlet from inrerspinous diameter (distance between two Ant. Sup. Iliac spine) of the aforementioned patients in Radiotherapy – Oncology Department in Imam Hossein hospital. Materials and methods: Interspious diameter on the surface kin (X) and pelvic inlet (Y) on simulation in the 44 men and 61 women were determined, coefficient (r) in men and women rm=0.8841 rw=0.8141 and linear regression analysis the following equation was obtained. Y=0.525X-0.339 R2=0.7815 for men Y=0.326 X+5.18 R2=0.6626 for women Conclusion: It was concluded that in both men and women, it is possible to estimate pelvic Inlet diameter from Interspinous diameter. But the coefficient of determination (Rsq) is lower in women than men.

Suitable seedbed preparation and adequate rate of seeding are necessary to obtain desirable plant population. These management practices are more important for plants with small seeds such as rapeseed. In this research, the effect of different tillage systems and seeding rates on machinery parameters, grain yield and yield components of rapeseed, cv. Orient, was studied in a split-split plot arrangement using randomized complete block design with three replications at the Kabutarabad Agricultural Research Station, Isfahan, Iran in 2003-2004 cropping season. Four primary tillage systems: moldboard plow to a depth of 20-25 cm, chisel to a depth of 15- 20 cm and 8-10 em and disk to a depth of 8-10 cm were assigned to main plots and two secondary tillage methods: disk and rotary tiller to a depth of 8-10 cm and three seeding rates; 4, 8 and 12 (kg.ha-1) were randomized sub-plots and sub-sub plots, respectively. Tillage methods showed no significant effect on mean weighed diameter of clods. Disk and rotary tiller had maximum and minimum machinery effective field capacity, respectively. By increasing seeding rate from 4 to 8 and then to 12 kg.ha-1, number of days from planting to the end of flowering and flowering duration decreased. Increases in seeding rate increased plant population. Using of 8 kg.ha-1 of seeds produced higher grain yield (2521 kg.ha-1) than 4 kg.ha-1 seeds (2400 kg.ha-1), but was not significantly different from 12 kg.ha-1 (2426 kg.ha-1). Based on these results, it might be concluded that disk harrow method as the secondary tillage with 8 kg.ha-1of seeds as desireable agronomic practices under conditions similar to this study. However, when rotary tiller is used, the seeding rate might decrease to less than 8 kg.ha-1.

Farm management needs creative methods to success. FMEA (Failure Modes and Effects Analysis) is a new method to analyze potential reliability problems in the development cycle of the project, making it easier to take actions to overcome such issues, thus enhancing the reliability through design or process. Anticipating these failure modes, being the central step in the analysis, needs to be carried on extensively, in order to prepare a list of maximum potential failure modes. Risk is measured in terms of Risk Priority Number (RPN) that is a product of occurrence, severity, and detection difficulty. This study attempted to improve clod mean weight diameter and soil inversion as indicators of tillage quality by FMEA methodology. The results showed that low soil moisture, slow speed of ploughing and great depth of ploughing is the most important factors that increase clod MWD with 900, 630 and 560 RPN, respectively. Also for soil inversion the slow speed of ploughing, not using coulter, low soil moisture and great depth of ploughing are important factors with 720, 648, 490 and 420 RPN. Using a split - split factorial experiment with 16 treatments and three replications also acknowledged the results of this method. After reforming the conditions and re-testing the experiment, results showed that clod MWD was reduced 20% and soil inversion increased 2% approximately. This study proposes the use of this technique in agricultural management.

Harvesting practices of potato is one of the most difficult, troublesome and sensitive stages. Potatoes enter the machine with huge amounts of clod and stones: In the meantime separation of potato some stone and clod, which are the same size as of that the potatoes, shall be confide red a major problem. Many methods of study by investigators are based on physical properties of potato, stone and clod. In the present research with regards to the farm conditions and economic situation of the Iranian farmers, the beveled conveyor method is recommended. In this method, primarily a schematic design of the separating section of the stones and clod and the crop was produced and important parameters such as the surface angle, conveyor-belt motion speed and type of the conveyor, which play a key role in the separation stage, were studied. The test was carried out on the factorial basis and complete random block, using 3 angles factors in 5 levels (5, 10, 15.17.5 and 20 degrees) and the speed on 5 levels (100, 200, 300, 400 and 600 RPM) and the belt type with 2 surfaces (soft and rough) repeated 5 times. The SPSS software was used to analyze data. The result revealed that the ideal combination of the angle, speed and belt type for acquiring the highest separation rate and the least amount of mix clod, stones of the separated potatoes are the order, and the crop would be the angle 15 degrees, the speed of 300 RPM, with the use of soft belt, and the angle of 17.5 degrees and the speed of 200 RPM is recommended for a rough belt.

Background and aim: According to the frequent tooth loss at molar sites and necessity to replace them, the purpose of this study was to evaluate the short term clinical and radiographic outcomes of fresh molar sockets immediately implanted, with tapered wide platform implants.Materials and Methods: 10 patients with the mean age of 46 were treated with the immediate implantation of 12 wide diameter and wide platform implants in the molar sites.Following the atraumatic extraction of molars and preservation of the interradicular septum, implantswere placed. Immediately after the insertion of healing abutment, implant primary stability was tested with the Periotest and the crestal bone level was estimated with the periapical long-cone radiographs.Four months later patients were recalled for final evaluations, the crestal bone loss was measured and the periotest values were judged with the Wilcoxon test.Results: All 12 implants were reported with no pain, infection and continuous radiographic lucency.The average PTV1 and PTV2 reported were -4.9±0.99 and -4.6±1.37 (-2 to -7).The difference between PTVs wasn' t statistically significant (P>0.05).The average crestal bone loss was 0.54±0.96.Conclusion: Successful results were achieved with wide diameter and wide platform implants with the appropriate case selection and surgical technique.