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Bars with standard hooks in tension are often used to anchor reinforcing bars where concrete dimensions element are not sufficient to provide the required development length for straight reinforcement. In previous researches, concrete breakout failure was the predominant failure mode of hooked bars. Closely-spaced hooks provide a lower strength per hooked bar than more widely-spaced hooked bars because the area of the breakout surface is reduced for the more closely-spaced bars. The effects of fy of bars, spacing, and confinement by ties or stirrups have been updated to reflect test results, in 25.4.3.1 of ACI 318-19. In this formula, The confining reinforcement factor ψr is based on test results reported by Ajaam et al. (2018). Base on ACI 318-19 definition, Ath is total cross-sectional area of ties or stirrups confining hooked bars. Therefore crossties are not included in the relationship. The purpose of this study is to expand the understanding of the behavior of confinement effect of crossties on development length bars with 90 degree bent hooks in tension. In this study, 3 simulated beam-column joints were tested as a continuation of previous work by Ajaam et al. (2018). The results of this experimental study show that the ACI318-19 provisions underestimate the contribution of confinement by crossties on the development length bars with 90 degree bent hooks in tension.

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There are a number of ideas to generate cloud and precipitation in the southern coasts of Caspian Sea, but none of them explain the cause of precipitation particularly heavy and super heavy precipitations precisely. This study describes main thermodynamic factors when the situation and location of synoptic patterns are effective. On the basis of daily data, monthly regimes and monthly trends of the Sea Surface Temperature (SST), difference between 2m air temperature and SST over the Caspian Sea as well as the SST gradients in different distances on latitude and its anomaly were calculated. For recognition of synoptic conditions, humidity advection, geopotential and sea level pressure maps were drawn. The results showed that there are three thermodynamic factors over the Caspian Sea to produce precipitation particularly from September to December. The first factor is arrangement and well organized of the SST gradients as it decreases from the south to the north of Caspian Sea. Also, the SST over the Sea must be enough warm to produce clouds and precipitation. The last factor is the difference between 2m air temperature and SST. When the synoptic patterns in different pressure levels are suitable for instability, the air-sea interaction process is the most important factor to produce the advection humidity, clouds and precipitation particularly heavier precipitation events in the north of Iran.

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Performance of the fiber optic networks with different physical topologies such as point-to-point, bus, ring and star, with respect to requirements as bit rates, topology structure, bit. error rate (BER) and optical component characteristics including optical amplifiers, filters, sources and detectors, are analyzed and simulated. For this purpose, maximum number of supportable nodes and throughput, crosstalk due to optical amplifiers and optical filters, reliability, physical limitations and fiber induced limitations such as dispersion and nonlinear effects (self phase modulation) are considered as performance evaluation criteria of different topologies. Dispersion and nonlinearities are simulated with split-step Fourier method, sometimes referred to as beam-propagation method. The fiber length can be estimated by this method, with respect to above effects and maximum tolerable power penalties. Parameters such as maximum number of supportable nodes and crosstalk are evaluated using amount of degradation in BER of receiver, BER is calculated using Gaussian approximation. Reliability of networks is modeled on the bypassing of the failed station as recovery mechanism in ring and bus networks and reliable assumption for central node in star network. By the way physical limitations in each topology, regarding its structure, are derived as an economical criterion. Results indicate that no topology can be preferred to others, however imposed limitations and requirements determine the optimum topology. Neglecting economical aspects, star topology is preferred from different points of view such as reliability, crosstalk and maximum number of supportable nodes. Results of above simulations can be used in calculating power penalties of different factors such as dispersion, crosstalk and nonlinearities. This penalties perform important role in estimating power budget of networks.

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The subject of obligation and possesstion should be definite, for instance, in a bilateral contract, consideration must be definite and if it is not so, the contract will not be concluded and that makes it void (Article: 216,338 and 384 civil code if Iran). The consideration may not be mentioned either due to carelessness or oblivion or when the two parties intentionally refuse to mention it in the contract and leave it to expert's view, customary law, common practices or well-known norms to determine it. When determination of consideration or price of a contract requires expert surveying and estimation or accounting operations, the involved parties are compelled to leave this task to a later time and not to mention it in the contract. The question in such a situation is whether these kinds of contracts are valid and binding or either of the parties can refuse to perform his/her commitments by resorting just to the pretext that the contract is invalid or the agreements is defected. At ention must be paid to the fact that not mentioning a price in the contract does not always mean that the consideration is indefinite and it depends on the agreement between the parties involved. Agreement on the methods and rule of determining the subject of obligation or possesstion, that is to say, specifying the rule and criterion for determining the subject of obligation or possesstion is sufficient because it is thus determined with that rule and such contracts cannot be considered as null and void with the pretext that the consideration is indefinite. In legal obligations and possesstions assigned by the law, it is usually preferable to determine methods and mention an exact price or cost. Not mentioning the subject of obligation or possesstion does not nullify the terms or the contract and the terms even in the Islamic jurisprudence and as it is quite well known they do not consider the indefinite condition as nullifying the terms or the contract. Since the indefinite condition cannot be considered a valid condition because obligation of an obliged person to perform an indefinite act is impossible, the condition shall thus be null and void but in cases where the ambiguity of the condition can be removed in future and it can be performed, the condition is not null and void.

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Investigating the trend of temperature changes occurring in the Persian Gulf can be used to determine the pattern of climate change in the region and to study the impact of these changes on aquatic habitats in the Persian Gulf waters.  This study was carried out to investigate the changes in sea surface temperature and sea surface temperature anomaly in Kharg and Hendourabi islands by using Environmental Research Division's Data Access Program (ERDDAP) of National Oceanic and Atmospheric Administration (NOAA) and  daily sea surface temperature and sea surface temperature anomaly  were investigated over a 35-year period.The results showed that the average annual surface temperature increased by about 1 °C over 35 years in Kharg and Hendourabi Islands and the average annual sea surface temperature anomaly in these islands were increased by 2 °C. The slope of this increasing trend on Kharg Island was more severe than Hendourabi Island. The most significant bleaching event in the Persian Gulf occurred in 2016-2017, with the highest increase in temperature in 2017. As water temperatures continue to increase in the coming years, the living conditions of the Persian Gulf corals are likely to deteriorate, and only some resistant species can survive in the Gulf.

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In this article, a special duct is introduced in which, inlet water jet initiates to oscillate after a short time and it causes the velocity and pressure to oscillate regularly. Considering that there is a linear relationship between the inlet jet velocity and its oscillations frequency, the flow rate can be calculated by measuring the pressure frequency. In order to study the flow field inside the current geometry of fluidic oscillator and also to find the optimum location for sensor to detect the pressure oscillation, the unsteady turbulent Navier-Stokes equations are solved by ANSYS CFX software. Having studied the grid independency, capability of K-ε and SST turbulence models for numerical simulation of unsteady flow inside the fluidic oscillator is considered. Then, according to the peak to average ratio (PAR) criterion, the qualities of pressure signals are compared at some points, to distinguish an optimum pressure sensor position. Afterwards, a prototype of fluidic oscillator flow meter is manufactured for the first time in Iran. Using this prototype and inserting the pressure and Piezoelectric sensor at the optimum point, the numerical simulation results are validated by the experimental data. Comparison between the numerical and experimental results shows that the SST model is more suitable for this flow simulation. Finally, by performing experiments in different flows, acquiring and processing pressure signals, the flow meter characteristic diagram (inlet jet oscillations frequency- inlet jet velocity) are extracted.

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In current study turbulent flow around a 3D square cylinder is modeled using large eddy simulation and shear stress k-ω turbulence modeling for three values of Reynolds numbers 5000, 46000 and 69000. The flow and sound field simulations are conducted by using fluent commercial software. Sound pressure level in the acoustical far field and on the surface of the square cylinder at incidence are evaluated for six angles of attack. Flow induced sound at far field is predicted by employing FWH analogy while sound pressure level over the surface model is directly estimated by measuring the unsteady surface pressures. The results of the present study showed good agreement with the available experimental results. The fluctuating lift and drag forces acting on the square rod and flow turbulence are the main sources of the acoustic field generation. It is noticed that the minimum of drag coefficient, mean and root mean squared (rms) value of lift coefficient, and sound pressure level in acoustical far field occurred at 13 angle of attack. The maximum Strouhal number occurred at 13o angle of attack. The Strouhal number for all angles of attack is noticed to be independent of the flow Reynolds number. Both turbulence models considered in this study predict the acoustic and flow features within an acceptable accuracy.

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In this research, the effect of square wave pulsating air on temperature distribution and film cooling effectiveness of flat plate at different frequencies and blowing ratios is experimentally and numerically investigated. Hot air is injected through the holes at an angle of 25 degrees. Square wave pulsed flow is generated at four frequencies of 2, 10, 50, 100 Hz, and five blowing ratios of 0.5, 1, 1.5, 2.4 and 3. To study the film cooling, Navier-Stokes equations are solved by a Reynolds average method. The SST k-ω model was used for turbulent modeling. The results showed that the film cooling effectiveness decreases with increasing of blowing ratio along with an increase in its rate of changes. The difference of centerline film cooling effectiveness between the numerical and experimental values decreases with increasing distance from the edge of injection hole. In general, pulsating decreases film cooling effectiveness in comparison with steady-state. The lift-off of the local jet increases under pulsation. In the pulsating state, the overall film cooling effectiveness decreases by increasing the blowing ratio at a constant frequency. On the other hand, increasing the frequency increases the overall efficiency of film cooling. The maximum averaged centerline effectiveness was obtained at a frequency of 100 Hz and a blowing ratio of 0.5 and the minimum value was obtained for a frequency of 2 Hz and a blowing ratio of 3. For pulsed flow, the maximum and minimum differences of the averaged centerline film cooling effectiveness between experimental and numerical results were 25.55% and 0.717%, respectively.

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Chicory (Cichorium intybus L.) is a typical Mediterranean plant distributed throughout the world and has different commercial uses such as salad, forage, inulin production, and coffee substitute. Health promoting characteristics of inulin as a prebiotic compound led to its biosynthesis pathway discovery. Two enzymes, namely, 1-SST and 1-FFT, are involved in inulin biosynthesis during normal phase. By cold nights or other factors, 1-FEHs enzymes degrade inulin to fructosyl units. To compare the strength of function of these genes in a wild type genotype with root type cultivar (Orchies) of chicory at three stages, i.e. 60, 90, and 120 days after seed planting, relative expression of those genes along with their corresponding metabolites were assessed using RT-qPCR and HPLC. Expression results showed that, unlike Orchies cultivar, relative expression of 1-SST in wild type genotype was ascending, relative expression of 1-FFT was very low and constant and there were high levels of relative expression of 1-FEH I gene during growing season due to flowering initiation. Also, glucose and fructose concentrations were upward, as result of 1-SST and 1-FEH I enzymes activity in wild type genotype, respectively. Degree of Polymerization (DP) of produced inulin had almost no increase due to low function of 1-FFT enzyme in the wild type genotype (DP< 5), but Orchies cultivar produced inulin with DP> 10 as expression of 1-SST decreased during growing season. So, it is possible to make inulin pathway in root type chicory cultivars more efficient by expanding and overexpressing 1-SST function using such wild resources through backcross breeding or biotechnology methods.
 

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This study examines the accuracy of three different methods for calculating the aerodynamic noise of the NACA-0012 airfoil in a homogeneous shear flow. The strength of flow vortices is crucial in aeroacoustic calculations, and it can be modeled more cost-effectively using the k-ω SST method or directly simulated up to 90% using large eddy simulation (LES) with higher cost. Additionally, a hybrid method called IDDES, which offers moderate accuracy and cost, is also considered in this research. The primary sources of noise generation identified are vortex shedding from the laminar boundary layer and its interference with the trailing edge, as well as Tollmien-Schlichting waves. Experimental data of the sound pressure level (SPL) in 1/3 octave is used to validate the accuracy of the methods. The results indicate that LES and IDDES show the closest agreement with the experimental data, with LES showing better accuracy. Furthermore, when studying the intensity of sound attenuation with distance, it is observed that the rapid attenuation of small vortices in LES leads to similar SPLs as IDDES after a distance of 1.2 meters. Moreover, since IDDES does not require strict regulations for creating a near-wall grid, it reduces the computing mesh by approximately 41% with less than 2 dB of error. This finding suggests that in similar applications, the IDDES method can be used as a suitable approximation instead of LES to expedite calculations and conduct parametric studies