Many studies have been published to address the growing issues in wireless communication systems. Space-Time Block Coding (STBC) is an effective and practical MIMO-OFDM application that can address such issues. It is a powerful tool for increasing wireless performance by coding data symbols and transmitting diversity using several antennas. The most significant challenge is to recover the transmitted signal through a time-varying multipath fading channel and obtain a precise channel estimation to recover the transmitted information symbols. This work considers different pilot patterns for channel estimation and equalization in MIMO-OFDM systems. The pilot patterns fall under two general types: comb and block types, with

The current study included testing the ability of plant Hydrilla verticillata (L. F.) on the accumulation of two heavy metals in its tissues, and use the plant in phytoremediation. The plant was exposure to different concentrations of chromium and copper metals (2.5, 5, 10, 15, 20) ppm, for a period of fourteen days, for each solution.The results showed that Hydrilla was more efficient in the removal of chromium, where the amount of the remaining concentration of chromium at the last day of the experiment was (0.20 ± 0.014- 0.66 ± 0.114- 0.99 ± 0.176- 0.79 ± 0.073- 1.80 ± 0.131) ppm, while for copper was (0.33 ± 0.06- 1.13 ± 0.39- 1.66 ± 0.05- 1.96 ± 0.043- 2.33 ± 0.0497) ppm at the last day of the experiment, respectively.

In the current study, gold nanoparticles were made using Acinetobacter baumannii broth culture. UV-vis, FTIR, XRD, FESEM, AMF, and zeta potential measurements were also used to study the properties of the Ab-AuNPs. The average was 66 nm, ranging from 20 to 90 nm. The examination results proved that the Ab-AuNPs are semi-spherical and varied from 20 to 90 nm, with an average of 66 nm. 

   MTT assay on the breast cancer cell line MCF-7 confirmed the anticancer activity in vitro. Cancer cells showed an important cytotoxic activity of Ab-AuNPs. The breast. Cancer cell. Line.MCF-7 but ineffective against the normal.cell line.MCF-10. The IC50 values of Ab-AuNPs were at 11.45 μg ml-1. The results proved that Ab-

The main purpose of this work is the construction of an optical parametric amplifier (OPA) to generate a 629 nm pulsed laser. KTP nonlinear crystals were used for both parametric oscillation and amplification. A singly resonant parametric oscillator (OPO) is constructed to generate a signal of 1.54 μm and idler of 3.4 μm when the OPO system is pumped by 1.064 μm Q – switched Nd: YAG laser. The signal was then mixed with the pumping beam in OPA system to form the wanted wavelength. The obtained optical conversion efficiency was 60%.

ABSTRACT

Critical buckling temperature of angle-ply laminated plate is developed using a higher-order displacement field. This displacement field used by Mantari et al based on a constant ‘‘m’’, which is determined to give results closest to the three dimensions elasticity (3-D) theory. Equations of motion based on higher-order theory angle ply plates are derived through Hamilton^, s principle, and solved using Navier-type solution to obtain critical buckling temperature for simply supported laminated plates. Changing (α₂/ α₁) ratios, number of layers, aspect ratios, E₁/E₂ ratios for thick and thin plates and their effect on thermal

  Corrosion behavior of aluminium in 0.6 mol. dm-3 NaCl solution in acidic medium 0.7 was investigated in the absence and presence of different concentrations of amino acid, methionine, as environmentally – friendly corrosion inhibitor over temperature range (293-308)K. The investigation involved electrochemical polarization method using potentiostatic technique and optical microscopy, the inhibition efficiency increased with an increase in inhibitor concentration but decreased with increase in temperature. Results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface and it was found to obey Langmuir adsorption isotherm. Some thermodynamic parameters ∆. and activation ener

This research is devoted to investigate the behavior and performance of reinforced concrete beams strengthened with externally bonded Carbon Fiber Reinforced Polymer (CFRP) laminates under the effect of torsion. In this study a theoretical analysis has been conducted using finite element code ANSYS. Six previously tested beams are used to investigate reinforced concrete beams behavior
under torsion, two of them are solid and the rest are box-section beams. Also, two beams are without CFRP reinforcement, which are used as control beams for the strengthened one, and the other four beams are strengthened with CFRP laminates with different number of layers and spacing. Numerical investigation is conducted on these beams, and comparisons b

A liquid-solid chromatography of Bovine Serum Albumin (BSA) on (diethylaminoethyl-cellulose) DEAE-cellulose adsorbent is worked experimentally, to study the effect of changing the influent concentration of (0.125, 0.25, 0.5, and 1 mg/ml) at constant volumetric flow rate Q=1ml/min. And the effect of changing the volumetric flow rate (1, 3, 5, and 10 ml/min) at constant influent concentration of Co=0.125mg/ml. By using a glass column of (1.5cm) I.D and (50cm) length, packed with adsorbent of DEAE-cellulose of height (7cm). The influent is introduced in to the column using peristaltic pump and the effluent concentration is investigated using UV-spectrophotometer at 30oC and 280nm wavelength. A spread (steeper) break-through curve is gained

A rapid, sensitive and selective spectrophotometric method was developed for determination of sulfathiazole (STHZ) in aqueous solution. The method is based on the  oxidative coupling reaction with 2,4-dinitrophenylhydrazine (2,4-DNPH) in a basic medium (pH 10.9) in the presence of  potassium periodate to produce an intense orange colour, soluble in water , stable product and absorbs at 492 nm. Beer's law was in the linear range 2.0-28.0 μg/ml of sulfathiazole, the molar absorptivity, Sandellʼs sensitivity index and detection limit were 1.1437 ×104 liter. mol-1.cm-1,0.0223 μg.cm-2 and 0.1274 μg/ml respectively. The RSD value was  0.75 - 1.12 % depending on the concentration. This method was applied successfu