توجه: محتویات این صفحه به صورت خودکار پردازش شده و مقاله‌های نویسندگانی با تشابه اسمی، همگی در بخش یکسان نمایش داده می‌شوند.
۱CONCRETE SHEARE WALLS STRENGTHENING STRUCTURAL ELEMENTS FOR SEISMIC REHABILITATION OF MASONRY BUILDINGS
نویسنده(ها): ،
اطلاعات انتشار: سومین کنفرانس بین المللی بتن و توسعه، سال
تعداد صفحات: ۱۰
This paper aims at investigating the behavior of masonry buildings strengthened with concrete shear walls. To this end, a masonry wall with openings extracted from an individual two–storey masonry building is modeled using ANSYS finite element software. A number of nonlinear static analyses were conducted on the model. The nonlinear behavior of the existing model was compared with that of the
model enhanced with concrete shear wall. The re sults obtained from the numerical analyses confirm that the load–carrying capacity of the unreinforced masonry buildings degrades due to the global failure of the wall. Whereas, the masonry buildings strengthened with concrete shear wall may achieve their target displacement. Moreover, the results reveal that the wall load–carrying capacity may
be upgraded, if the added shear wall is connected to both the diaphragm and adjacent masonry wall.<\div>

۲Investigation of cured shapes of trapezoidal corrugated composite skins
نویسنده(ها): ، ، ،
اطلاعات انتشار: کنفرانس بین المللی فرآورش پلیمرها، سال
تعداد صفحات: ۴
During the manufacturing process and operating conditions of multilayered fiber–reinforced quasi– Trapezoidal corrugated composites with variable fiber orientations, residual stresses build up due to the directional expansion of the unidirectionally reinforced single layers. Depending on the properties of skin, these inhomogeneous residual stresses, which are primarily caused by thermal effects, can lead to out–of–plane displacement in the unsymmetric laminates. Instead of avoiding laminates curvatures, they can be advantageously used for technical applications such as morphing structures. In this research, parameters such as geometry and dimensions of corrugation made of Graphite\Epoxy are investigated and simulated by commercial FEM software, Marc Mentat<\div>

۳Dielectric study on binary mixture of 2 – butanol with, 2–ethyl–1– hexanol at T=298.2 ,308.2 , 318.2K.
اطلاعات انتشار: سومین کنفرانس تخصصی ترمودینامیک، سال
تعداد صفحات: ۵
The interaction between the molecules of 2–butanol (sec–BuOH),2–ethyl–1–hexanol (2EH), was studied at static frequency. Static permittivity at three different temperatures was computed for the above system.Permittivity at static frequency was measured at different concentrations of the mixtures at different temperatures and they were used to calculate dielectric parameters such as Kirkwood correlation factor , excess permittivity, Bruggeman parameter.<\div>

۴Dielectric data of binary mixtures of 1,2–butandiol with 1,4– dioxane at T = (298.2, 308.2 and 318.2) K
اطلاعات انتشار: سومین کنفرانس تخصصی ترمودینامیک، سال
تعداد صفحات: ۴
Relative permittivity measurements were made on binary mixtures of (1,2–butandiol + 1,4–dioxane) for various concentrations at T = 298.2 K, 308.2 K and 318.2 K. The molecular dipole moments were determined using Guggenheim–Debye method in the temperature range of (298.2 to 318.2) K. The variations of effective dipole moment and correlation factor, g, with the mole fraction in these materials were investigated using Kirkwood–Frohlich equation. The pure compounds showed a negative and small temperature coefficient of effective dipole moment.<\div>

۵Investigation of the effects of bed forms on sediment transport coefficient by taking interaction of wave–current into account
نویسنده(ها): ، ،
اطلاعات انتشار: هفتمین کنگره ملی مهندسی عمران، سال
تعداد صفحات: ۹
In this paper, the effects of bed forms on sediment transport coefficient were studied by using two physical and mathematical modeling programs, in order to generate the graphical changes of bed profiles under effects of waves and currents. Sediment transport coefficient (STC) is defined as the ratio of sediment velocity to the velocity of water particles. STC was studied at different states of currents, waves, and wave’s interaction with currents in order to define a modified ratio for bed load movements in the boundary layer. If applying this modified ratio (STC), in the mathematical program, improve the graphical changes in bed level and have a better fitness with the measured changes, it will have more validity to use it in the modeling programs instead of using the previous values of STC which considered a single value for this ratio. However, reliable experimental data are essentially required to examine the validity of the model.<\div>

۶Displacement Mechanism, Oil Recovery and Main Problems during CO2–Foam Flooding: A Review
نویسنده(ها): ، ،
اطلاعات انتشار: دومین کنفرانس بین المللی نفت، گاز و پتروشیمی، سال
تعداد صفحات: ۸
Gas flooding process has relatively poor sweep efficiency due to the high mobility ratio between the gas and crude oils under reservoir conditions. A need for mobility control during gas flooding has led to the study of foam flooding. Foam injection methodologies are consisting of gas and surfactant solution co–injection, surfactant solution alternating gas injection and pre–prepared foam injection.In this paper, the displacement mechanisms, oil recovery and main problems during CO2 and surfactant solution co–injection (CO2–faom flooding) have been investigated.It seems that aqueous phase mobility to be reduced by reducing relative permeability during CO2–foam displacement. However, experimental results show the inverse trend. Also, the experimental investigations show that two foam flow regimes can be generated during CO2–foam flooding: high quality regime or low CO2 fractional zone and low quality regime or high CO2 fractional zone. The CO2 mobility decreases with increasing CO2 fractional flow during high quality regime. The investigations clearly indicate that CO2–foam flooding improves oil recovery by following mechanisms:  CO2 mobility reduction  Increment of CO2 dissolution in the oil  Water in oil or oil in water emulsifications High viscosity of the crude oils and stability of the foam are the main problems during CO2–foam flooding. The results show that use of steam injection before CO2–foam flooding is a logical way to alleviate the problem of high viscosity of the oil. In steam–CO2–foam flooding at first steam is injected to reduce oil viscosity and then CO2–foam flooding is performed. The investigations indicate that stability of the foam is affected by temperature and pressure. The increase of temperature and pressure leads to the decrease of foam stability. However, efficient displacement of oil or a decrease in CO2 mobility during CO2–foam flooding is not depending on foam stability.<\div>

۷Laser surface alloying of aluminum with chromium powder by pulsed Nd:YAG laser
نویسنده(ها): ، ، ،
اطلاعات انتشار: سومین کنفرانس بین‌المللی آلومینیوم ایران IIAC2014، سال
تعداد صفحات: ۴
In this paper, laser surface alloying of AA6061 aluminum alloy with chromium was investigated. Chromium powder was pre–placed on Al substrate and subsequently laser alloyed using pulsed Nd:YAG laser with a maximum mean power of 400W at different output powers and scanning rates in the argon gas shielding. Optical and Scanning electron microscopy equipped with EDS analysis and XRD were used for characterization of the phases formed by laser alloying. Alloyed layer contained relatively large amounts of Al–Cr intermetallic compounds dispersed in a matrix of α–A1. The intermetallic compounds appeared in two needle–like and equiaxed cell morphologies, organized in a dense network. At 240W output power and scanning rate of 8 mm\s, a defect–free layer containing of Al7Cr and Al4Cr intermetallics was achieved.<\div>

۸Simultaneous determination of lovastatin and niacin in tablet by first and third derivative spectrophotometry and H–point standard addition methods
نویسنده(ها): ، ، ،
اطلاعات انتشار: Research in Pharmaceutical Sciences، هفتم،شماره۲(پياپي ۱۴)، ۲۰۱۲، سال
تعداد صفحات: ۸
Most cardiovascular diseases need to be treated by more than a simple drug and the use of combination products diminishes noncompliance. Advicor® as a combination product of a vitamin and a fat lowering agent has no monograph in official pharmacopeias for its quality control purposes. In this study, first and third derivative signals for NA and LV quantitation at the two pairs of wavelengths, 261 and 273 nm; 245 and 249 nm were monitored with the addition of standard solutions of NA or LV, respectively. The limits of detection were 0.03 and 0.32 mg\L for LV and NA, respectively. The limits of quantitation were 0.09 and 0.78 mg\L for LV and NA, respectively. RSD% for both interday and intraday precision was lower than 2.6 and 2.7% for LV and NA, respectively. Selectivity of the method was assessed for both degradation products produced in stress conditions and common excipients that may present in the pharmaceutical dosage forms. The recommended procedure was successfully applied to real samples.
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