Abstract: Stopband split ring resonator (SSRR) is presented in this paper for measuring complex permittivity of liquid with different position of microfluidic channel operates at resonant frequency of 1 GHz. The sensor was fabricated and microfluidic channel is located in the gap groove with two different positions of the carrier where the electric field is as large as possible.  The sensor has been tested with several solvents to verify its sensitivity where the electric field interacts with the liquid filled in a quartz tube and hence alter the SRR behavior. The electromagnetic properties (complex permittivity) of the solvent can be extracted from shift in the resonant frequency of the resonator due to perturbation phenomenon.

Abstract: The natural convection heat transfer has many applications in engineering like solar collectors, cooling of electronic equipment and geothermal engineering. The present work demonstrates the recent publications in the last ten years in this specific subject for a body located in complex shapes like rhombic, wavy, trapezoidal, elliptical and Parallelogrammic enclosure. Many parameters like Ra, Nu, number of undulations, the position of the inner body had been addressed and discuss to draw the main conclusions and recommendations.  It is worthy to mention that wavy enclosure had been investigated less than the other simple enclosure shapes due to its complexity. Beside that entropy generation should be included in the future studies in complex shapes of enclosure as this will helps the researchers to extended their studies. The inner bodies inside trapezoidal, parallelogrammic enclosure are very limited and more investigation should be done.

Abstract: A rotating tubular packed bed electrochemical reactor was used for the electrochemical removal of cadmium (Cd) from simulated wastewater. Impacts of electrolysis operating parameters: current (0.56–2.8 A), rotation speed (100–500 rpm), initial cadmium concentration (20–100 ppm), and pH (3-9) were investigated. Response surface methodology and Box-Behnken design were used for optimizing the process parameters where cadmium Removal Efficiency (RE %) was selected as a response function. Findings of the present work suggested that currently has a main impact on the removal efficiency of cadmium followed by rotation speed, then concentration and pH. The results of the regression analysis showed that experimental data could be fitted to a second-degree polynomial model with value of the determination coefficient (R2) equal to 91.8 %. Optimal conditions for process parameters based on the RSM model were initial Cd concentration of 32.0 ppm, current of 2.8 A, rotation speed of 371 rpm and pH = 3, where a final cadmium concentration less than 0.3 ppm was obtained after 30 min of electrolysis process (RE= 99.28% ).

Abstract: The present study, experimentally investigated the mixed convection in a square enclosure partitioned in two layers. The experiments were performed with Al2O3–water nanofluid (upper layer) and superposed porous medium (lower layer) with an adiabatic rotating cylinder at the center of the cavity. The boundary conditions of the experimental study were; the upper and lower walls were assumed adiabatic, the right wall was heated, and the left wall was cooled. Experimentally, 15 K-type thermocouples and thermal imaging camera were employed to measure the temperatures distribution inside the cavity when the concentration of nanoparticles (ɸ = 0.06), the temperature difference (∆T) between the cold and hot walls was (6, 8, and 10) °C, and angular rotational velocity (-50, -25, 0, 25, and 50) rpm. The results of experimental data showed that in general, the distribution of temperatures was very well along the upper half of the enclosure, while in the lower half the temperature distribution was confined near the hot wall region. When the circular cylinder rotates in counter-clockwise, it noted that the effect of speed is evident in the downside of the cylinder, while the temperature distribution in the left upper part of the enclosure decreasing. When the circular cylinder rotates in the clockwise direction, the results showed that the effect of cylinder rotation was around cylinder only. Moreover, the results demonstrated that the increasing temperature difference leads to a noticeable increment in the intensity of the flow.

Abstract: In the last era of the digital revolution, architectural outputs with distinctive void formations appeared. The development in digital technologies, which adopts solid geometry in the formation of its interfaces. So the void became an integral part of the design at the level of three dimensions, to serves as a fourth dimension of architecture. By connecting architecture with the time, the limits of length, width, and height fade away and change from the limits of place to those of time, and this void shifts out from achieving the aesthetic needs to achieving functional and structural needs. The direct correlation of the architectural void with the process of forming the interfaces led it to be considered as a basic architectural formation unit, and in light of this,  the research problem was presented as (insufficient knowledge about the importance and role of the three-dimensional architectural void and the mechanisms of its formation in the interfaces of contemporary digital architecture as a void that generates or creates the design within the needs of the designer and the receiver ). The aim of the research came to reveal the concept of architectural void at the three-dimensional level, as well as revealing strategies and mechanisms for shaping the void in the interfaces. The research adopted the descriptive and analytical research methodology in proposing theoretical knowledge extracted from previous studies of building the theoretical framework for the geometry terms which contains  (strategies for forming digital void, characteristics of void in digital output, features of digital spatial structure),  and applying it on contemporary architectural models with a qualitative measure that is aimed at knowing the effect of terms on the selected samples and the percentage of their effectiveness in the characteristics of the digital output, and verifying the main research hypothesis which stipulated the adoption of the strategy of forming the digital void to combine the mechanisms of digital formation that is used to create void formation to meet the needs in contemporary architecture. The results indicated that the disappearance of the boundaries between the interior and exterior over time led to the use of the void in the formation of the building’s outer mass at the three-dimensional level so that the formation of the mass is based on that void which is called (design-generating void) and the structure which is created by the void called (the spatial structure), as its formation depended on "geometry" and its methods of formation.

Abstract: The present paper deals with the electrochemical treatment of wastewaters generated from Al-Diwaniyah petroleum refinery plant in a batch electrochemical reactor using stainless steel cathode and porous graphite anode. Effects of operating parameters such as current density (5-25mA/cm2), pH (3-9), addition of NaCl (0-2g/l), and time (20–60min) on the removal efficiency of chemical oxygen demand (COD) were investigated. The results revealed that both pH and NaCl addition have the main effect on the COD removal efficiency confirming that the system was governed by reaction conditions in the bulk of solution not upon the electro oxidation of chloride ion on the surface of the electrode. Parametric optimization was carried out using Response Surface Methodology (RSM) combined with Box–Behnken Design (BBD) to maximize the removal of COD. Under optimized operating conditions of initial pH: 3, current density = 25 mA/cm2, NaCl conc.  = 2g/l, and time = 60 min, the removal efficiency of COD was found to be 98.16% with energy consumption of 9.85 kWh/kgCOD which is relatively lower than the previous works.

Abstract: This paper presents and validates a numerical model utilizing the nonlinear finite element software ABAQUS/Standard to simulate the performance and failure of GFRP reinforced concrete beams under high temperature. A numerical model was firstly developed by selecting the proper geometrical and material modelling parameters with suitable analysis procedure available in ABAQUS/Standard. The developed numerical model was verified by comparing numerical results with the corresponding results of experimental test extracted from current study on GFRP-RC beams under different elevated temperatures ranges from (20 to 600ºC). Validation results have indicated the accuracy of the suggested numerical model. The validated numerical model was implemented to investigate the effect of important parameters on the performance and maximum load of GFRP-RC beams under different elevated temperatures that are not considered in the current experimental tests. These parameters include effect of exposed time or time- temperature history; effect of temperature distribution around the beams cross-section. Results indicate that the finite element software ABAQUS/Standard can reasonably predict the performance and ultimate load of GFRP-RC beams under different elevated temperatures.

Abstract: Green roofs are a layer that effectively working on blocks of solar radiation from entering the building's structure below partially. Its work as a passive cooling technique, and have the potential to reduce the high surface temperature of conventional roofs because of the soil thermal resistance, evapotranspiration, and several effects for foliage shading. This affects the heat flux flow of the roof that in turn influences the indoor thermal conditions and the building energy demand. The research goals are to test the influence of the green roof on reducing heat transfer to the interior of heavy structural buildings. The experimental part was done to examine the effect of the green roof and compare it with a standard roof under influence of ambient air temperature, solar radiation, and wind speed and test the effect of the green roof on reducing heat transfer inside the building. The model site was at the Diwanyah city (Latitude: 31.9868 and Longitude: 44.9215), the engineering college campus, Qadisiyah University. The experimental setup includes two cubicles, with equal internal volume values (163cm * 163cm * 105cm). The experimental results showed for the period 5-8 September 2019. The maximum zone temperature was 46.4 °C for traditional roof and 37.06 °C for the green roof at 3:24 p.m. The results showed that the maximum internal temperature was 46.97 °C and 36.42 °C for the traditional roof and green roof respectively at 3 p.m. Also,  the results for period 18-21 July 2019 noted that the zone temperature decreased by 7.5 °C and the maximum temperature of the internal traditional standard roof’s surface is 45.66 °C  and 37.41 °C for the green roof.

Abstract: Mixtures of different types of amine solution Monoethanolamine, Diethanolamine, and Triethanolamine were experimentally used to investigate the overall mass transfer coefficient (KGa) at different operating parameters. The experiments were made in a packed bed reactor (PBR) with 75 cm in high and10 cm inside diameter as a gas-liquid contactor at 25℃ and atmospheric pressure, using a simulation gaseous mixture (air, carbon dioxide)  with recycle stream (semi-continuous process). Experimental design process Taguchi was employed. Four factors and three levels were chosen and exploded using L9 (3 ^4) orthogonal array design. These parameters for semi-continuous  process were namely: gas flow rate 5,10,and 15 L/min ,airflow rate80,90,and 100 L/h, liquid flow rate 400,450,and 500 mL/min  and time absorption time  30,45,and 60min . A Shimadzu GC-8A Gas Chromatograph with a thermal conductivity detector was used to measure the CO2 concentration absorbed in aqueous blended solution. The maximum value for CO2 loading was 8.622 (mol CO2/mol amine) at 15 L/min gas flow and 450 mL/min liquid flow and 100 L/h airflow for 60 min from absorption time. The results showed that the max value of KGa is 0.048 S-1.

Abstract: This research aims to investigate the literature review on the extraction of algae oil, production of algae methyl ester(AME) biodiesel and the effect of microalgae biodiesel on the performance, combustion and exhaust  emissions of diesel engine. The study dealt with researchers who published their reports between 2006 and 2020. Researches now concentrate on renewable energies, and biodiesel is one of those renewable energy sources. Biodiesel is a fuel similar to diesel and has many positive aspects such as quality, renewable energy, lower exhaust emissions and greater lubricity. In addition to the use of microalgae in the production of fuels, they are used in reducing CO2 of the atmosphere which in turn results in better air quality to breathe and cleaner environment. Many researchers have paid attention to produce biodiesel derived from microalgae that represents one of the oldest living creatures on the globe. However, by comparing with diesel, it has some drawbacks like lower heat content, higher density, viscosity, and NOx emissions. Optimization strategies is still recommended to fight the side effects of using biodiesel instead of original diesel fuel.