Seismic noise can be divided to random and coherent in reflection survey. The ground roll is a coherent noise in land seismic data that has high energy، high amplitude، low frequency and low velocity. It usually masks the reflections. Therefore، it must be attenuated in the seismic data processing. In this paper، we proposed a modification on the Common Offset Common reflection surface method to attenuate ground roll and random noise. The CO CRS stacking operator is a hyperbola; therefore، it fits the hyperbolic reflections in the prestack data. Ground roll and random noise has linear and uncorrelated traveltime respectively. When the CO CRS operator is applied to the data، the reflection events can be detected by the coherency analyses. High coherency values belong to the reflection events، and low values indicate that no events with hyperbolic traveltime are detected. As a result، when the events are distinguished، any event with non-hyperbolic traveltime can be muted. We applied the proposed method on two real land data sets. The new method was compared with the f-k filtering and conventional CO CRS stacking after the f-k filtering. Results showed that the proposed method attenuated aliased ground roll better than the f-k filtering and conventional CRS. Further investigation was the effect of reflection amplitudes on ground roll attenuation by the CO CRS stacking. For a better attenuation، the minimum coherency of reflections had to be higher than the maximum coherency of the ground roll. Therefore، the intersection of the minimum reflections coherency and the maximum ground roll coherency is an SNR threshold (dB) for ground roll attenuation with FO CRS stacking.

Offset agreements are legal trade practices, Common in the aerospace and military industries. The international names for these commercial practices are various: industrial compensations, industrial cooperation, Offsets, industrial and regional benefits, balances and equilibrium. An Offset agreement is an agreement between two parties whereby a supplier agrees to buy products from the party to whom it is selling, in order to win the buyer as a customer and Offset the buyer's outlay. Generally the seller is a foreign company and the buyer is a government that stipulates that the seller must then agree to buy products from companies within their country. Indeed, industrial compensation practices required as a condition of purchase in either government-to-government or commercial sales of articles and/or services. Often, the aim of this process is to even-up a country's balance of trade. Although the Offset agreement is so significant, it has been rarely known for inner academic associations; in this work, after brief introducing of the mechanism, variations and compensatory obligations of these contracts, we discuss about the structure of them and the tendency of their parties to bind independent contracts related to each other throughout a document called the protocol.

In order to study the genetic control of resistance to Common smut in maize, two resistant inbred lines, K1264/1 and K47/2-2-21 and two susceptible inbred lines, K3304/1-2 and K47/2-2-1-3-3-1, were crossed as K1264/1 × K3304/1-2, K47//2-2-21 × K3304/1-2 and K1264/1 × K47/2-2-1-3-3-1. The F1, F2, BC1 and BC2 progenies were produced and evaluated along with parents using randomized compelet block design with three replications. All generations were artificially inoculated with spordia of Ustilago maydis suspension. Inoculation was carried out 7-10 days after silking through injection of 3 ml of 106 spores/ml fungal suspension, using tip injection method. At maturity, disease severity was determined based on ears infection and analysed according to generation means analysis method for three crosses. Joint scaling test showed that the presence of additive, dominance and epistasis effects, especially additive × additive and dominance × dominance type, and in lesser extent, additive × dominance, in genetic control of resistance to maize Common smut. Average broad and narrow-sense heritability based on three crosses data were estimated 80.3 and 57.3, respectively.

In this study, an experimental and numerical analysis is done to study the flow characteristics of an Offset and non-Offset axisymmetric jet impingement on a circular cylinder. The purpose of this study is investigation of the behavior of the cutting gas jets and finding the optimum distance between nozzle and cylinder to achieve maximum cutting performance. Finite volume approach is used to solve the governing equations for a turbulent, incompressible jet numerically. According to the literature the suitable turbulence model for this purpose is realizable k-e. Velocity and pressure fields around the cylinder and pressure and shear stress distribution on the cylinder surface are determined for various cases. Also, some experiments are done to validate repeatability of experiments and numerical results. Comparisons between numerical results and experimental measurements validate the accuracy of numerical results. Also, results show that if the horizontal distance between the nozzle outlet and the stagnation point of cylinder is 2.5D, the shear stress on the cylinder surface has maximum value. Therefore in this situation jet has a maximum performance in cutting procedure.

It has been shown over several decades of radar research that the exploitation of diversity in a number of domains such as space, frequency, time, polarization, and, recently, waveform can provide increased agility, flexibility, reliability, and capabilities to the radar system. However this is often achieved either through efforts in system design, increased hardware complexity, or by employing additional resources. In the frequency diverse array (FDA) the subsequent antenna elements are fed with stepped discrete frequencies. So a range-angle dependent radiation pattern is made possible. It is possible to apply different frequencies with different patterns to the elements of FDA to achieve different radiation pattern. In this paper, a frequency diverse array with non-uniform inter-element frequency Offset called quadratic-FDA has been proposed, that its variation is a function of physical distance of elements from the first element. To produce the coefficient of the frequency Offset two Frequency Offset generators has been proposed. In The first proposed method uses linear distance as a input of function and the second one uses multiples of the roots of the Chebyshev polynomial. The proposed strategy provides a non-periodic beampattern, with a maximum that can be steered in space by selecting appropriate excitation weights of the antennas. This single-maximum beampattern, in contrast to multiple-maxima beampattern of the other forms of FDA, can help to further reject range-dependent interferences, causing improved SINR and increased detectability.

The use of zeolite was investigated to improve the environmental condition of Common carp. The fingerlings of 13 grams were tested in 4 treatments. Each treatment contained 60 fish and 3 replications, in RBD experiment design. The treatment was performed 20, 40, 80 and 120 mg/l and one without zeolite as control. EC, T, O2 and salinity was equal but the amount of No2, NO3, NH4 and total hardness, was lower in zeolite treatment compared to the control group. Other parameters such as TDS, pH and sulfide were not different. The results showed that using zeolite can improve the water condition but the SGR, PER, FCR and total weight, in spite of pronounced difference between the dosage of 8 and 120 mg/l, the difference was not significant. In treatment of 80 mg/l, weight increased for 31%, GR for 29%, SGR for 29%, PER for 42%, more than the control group. FCR in the control group was 3.07 while in treatment with 80 mg/l zeolite, it was 2.34.The present study showed by using zeolite and by good management to improve the water condition, it is possible to improve the growth parameters of fish.

Summary Radio magnetotelluric (RMT) and ground penetrating radar (GPR) are known as the near-surface geophysical methods in groundwater investigations. The RMT method provides information about the variation of the electrical resistivity of 50 m of the uppermost part of the ground. High-resolution structural information can be extracted from the GPR processed sections of the very shallow ground. Combining the obtained data using these two methods lead to valuable results on the identification of near-surface layers and structures. In this study, we propose a new constraint for the two dimensional (2D) inversion of the RMT data. We have investigated a known aquifer located in Heby, Sweden, to assess the constrained inversion results using a joint interpretation approach. RMT and GPR surveys have been carried out along two survey lines having the lengths of 870 m and 550 m, respectively. The results show that thick saturated zones are distinguished quite well either in the joint interpretation results or when using the constrained inversion approach. In such cases, the main problem is to locate the water table in the inverted RMT sections. Imposing smooth regularization in the inversion results turns rather sharp boundaries into the gradual transition zone in the final resistivity models. Thus, using the GPR Common-Offset (CO) reflections as constraints in the inversion of the RMT can recover the water table as a sharp interface in the RMT inverted model. Thin saturated zone has not been recognized in the RMT sections, due to low resolution of the RMT method. For verification of the results, we have evaluated a synthetic model with similar physical properties to the study area. In such circumstances, the results need to be improved either in the joint interpretation or the constrained inversion approach using CO sections. Hence, harder constraints through our proposed scheme have been incorporated into the inversion routine to detect a thin aquifer and achieve a more realistic model. Introduction The RMT and GPR methods are among the most useful non-invasive methods, which can provide continuous data for groundwater exploration. The RMT method due to its limited range of frequencies (10-250 KHz) has low resolution, especially at very shallow depth, and the GPR method itself suffers from its limited penetration depth. Hence, it seems that combining the modeling results of these two methods leads to a more accurate anomaly definition. Reflection (seismic or GPR) data are usually used as constraints in electromagnetic data inversion. Although all reflectors in seismic and GPR sections are not attributed to the distinct resistivity contrasts, in GPR they are mainly related to the dielectric contrast or may occur due to the thin layers embedded in homogenous geological formations. Thus, we propose an alternative scheme to incorporate interfaces with distinct resistivity contrast in the RMT data inversion. Methodology and Approaches Using all GPR reflections as constraints in the RMT data inversion may cause some artifacts in the final inverted model. In low clay content formations, such as clean sand and gravel formations, dielectric constant and resistivity are mainly related to the volumetric water content. Therefore, we propose a new structural constraint based on the assumption that the resistivity and water content contrasts occur at the same boundaries. To establish this constraint, we have used Common mid-point (CMP) velocity analysis as well as the combination of Topp’ s and Archie’ s relationships. As a result, an initial resistivity model has been deduced from the CMP velocity analysis that can be used as a priori information in the RMT data inversion. Results and Conclusions Thick saturated zones (having thicknesses of more than 10 m) have been distinguished quite well by applying smooth constraint inversion of the RMT data as the joint interpretation of The RMT and GPR data leads to a reasonable outcome in this regard. Although sharp boundaries are mapped as gradual interfaces in the inverted resistivity section of the RMT data, such interfaces are recovered well by incorporating the GPR result as a priori information in the constrained inversion of the RMT data. The water table at a depth of 10 to 20 m, and consequently, the saturated zone is resolved well in this constrained inversion method. It correlates to the borehole log information. On the other hand, thin saturated layers could not be distinguished in the RMT sections due to its low resolution. It means that the water table at a depth of 10 to 15 m is not mainly detected when only the determinant mode data are used. In such areas, the constrained inversion of the RMT data using the water table location deduced from the CO GPR data also fails. However, we have incorporated harder constraints through the model covariance matrix and prior information in our proposed constrained inversion routine. Using this approach, a local thin aquifer has been recognized well. Furthermore, our proposed technique can be used in the inversion of other electric and electromagnetic data.

Nowadays, computer simulations are becoming more and more important in performance investigation of thermal systems. In this article, radiator from a cooling system of a diesel engine of ER24PC locomotive is simulated. The radiator is composed of parallel and series arrangement of compact heat exchangers with Offset strip fins. It also has two high and low temperature sections. Due to the complexity and compactness of heat transfer plates implemented in the radiator, the simulation is carried out in two steps. First, a relation for coolant-side and air -side heat transfer coefficient is correlated using computational fluid dynamics. Due to vortex shedding phenomenon in the staggered fin arrays, governing equations are solved transiently in twodimensional space. Appropriate timestep for the transient solution is chosen according to time period of vortex shedding from the surface. In the second step, using the developed computational code, the overall thermal performance of the radiator is simulated as a heat exchanger. Consequently, temperature distribution inside the radiator and its thermal performance are studied. Amount of heat released from the radiator in different flow rates and temperatures of fluid flowing out of the radiator are among the outputs of the developed code. Finally, thermal performance curve of radiator is obtained.