Engineering and Technology Journal

The Microbial Fuel Cell (MFC) is a bioreactor with which the chemical energy in chemical bonds of organic compounds are converted to electricity under anaerobic conditions through catalytic reactions of micro-organisms. It has been familiar for a long time that electricity can be generated directly through using bacteria to break organic matter. A microbial fuel cell can also serve in different wastewater treatment to destroy organic matter. The development of MFC technology requires a greater understanding of the microbial processes for MFCs, and their components, limitations, factors and design this system, to be simpler and large scale system developed; so that it would increase electricity production while being cost-effective. This review discusses, what is the MFCs and the basic principle of how MFC operate, the most essential MFC components and their relevance, multiple MFC designs that have been presented as efficient configurations, Applications of MFCs, and several types of wastewater as substrates in MFC also highlighted.

In this paper, an automated test setup for PV panels using LabVIEW and several microcontrollers (μCs) based embedded systems has been designed, tested, and implemented. This PV testing system has been characterized as fully automated and the only human intervention required is to install the PV panel and to set the required testing conditions. Several PV panels were evaluated and tested, the obtained results showed a high degree of accuracy and conformity with several testing schemes that have been carried out numerically, manually and manufacturer specifications. The designed system is characterized by a high-performance standard with accuracy, precision, and resolution (9 mV / 1.8 mA) that is good enough to test any PV panel of 12 V and 24 V rating. This system can test and calculate the maximum power point for any PV panel operating at any given working condition by applying different amounts of solar irradiance from 0 W/m2 to 1000 W/m2 to simulate the amount of solar irradiation at any time and everywhere on earth. This system also mimics the environment temperature by providing ambient temperature ranged from 0 °C to 50 °C to simulate the variation of weather around the year.

In this research paper, results are obtained from Reactive Powder Concrete (RPC) push-off specimens - double L shape subjected to direct shear loading. Different parameters considered are compressive strength, percentages of steel fiber, presence of aggregate and shear reinforcement. The results show that increasing in steel fiber content starting from 0.0% and ending with 1.5% leads to increases in the shear strength by (261%) and attempt to decrease its brittleness. The presence of steel fiber content enhances and improves the tensile strength and the shear strength. Using RPC in constructing the specimens enhances the shear strength by 29.6% compared with NSC specimen.
Shear strength increased by 25% when the compressive strength increased from 75 to 90MPa. The presence of transverse steel rebar in the direction of shear line increased the shear strength by (108.3%) as compare with the specimen without shear rebar. The presence of small aggregate in RPC mix creates an increase in the shear strength by (9.1%).

The present work investigated the thermal performance of thermosyphon by using distilled water as a working fluid at different filling ratios (50%, 60%, and 70 %). The thermosyphon was manufactured from a copper tube with outer and inner diameters (26 and 24) mm, respectively. The thermosyphon was tested experimentally at different input power (100, 200 and 300) Watt. The operating temperature of the oil was chosen below 85°C. Experimental results revealed that the filling ratio of 60% exhibited the best heat dissipation at the highest operating temperature. While the low operating temperature and 50 % filling ratio show better heat dissipation. Further, it was found that the thermal resistance of the thermosyphon was obviously decreased with increasing the input power. The percentage decrease in the thermal resistance of the thermosyphon at a filling ratio of 0.6 was 14.6 % compared with that filling ratio of 0.5 at an input power of 300 W.

The operation and performance of heat-pump systems are affected by indoor and outdoor operating conditions. Power consumption and system efficiency are related to evaporator and condenser working pressures. Intelligent controllers such as a proportional integral (PI) controller improve the performance of variable speed refrigeration systems (VSRs) with electronic expansion valve (EEV). Evaporator and condenser pressures affect the system power consumption and efficiency. In this study, the influence of evaporator and condenser temperatures on the performance of a variable speed refrigeration system with an EEV was experimentally investigated at constant cooling load. The experimental system comprises of a rotary compressor, shell-and-coil condenser, EEV, and shell-and-coil evaporator for one-ton cooling capacity with refrigerant R410. Compressor speed and EEV opening are controlled by a PI controller with two control loops and the refrigerant superheat (DS) is maintained at 7°C. The results show that at constant cooling capacity, the refrigerant flow rate rises with the increase in the compressor speed. The coefficient of performance (COP) is improved with low compressor speed. The System COP is increased by 3.3% with increasing evaporator inlet water temperature for 2°C due to the reduction in the compressor speed and compression ratio. High condenser inlet water temperature promotes the refrigerant subcooling.

Rice husk is considered a main agricultural waste in Iraq. High purity SiO2 NPs were produced from rice husk by enhanced precipitation and developed leaching processes for the preparation of silica from RH. In this study, pre-treatment for rice husk was with 3N HCl, and calcination at 700°C was achieved, then followed with a leaching process with (1.5, 2, 2.5, 3) N NaOH concentrations. The characterizations of the prepared SiO2 NPs were studied by X-ray fluorescence (XRF), X-ray diffraction (XRD), and atomic force microscopy (AFM). The results show that the prepared SiO2 NPs have an amorphous structure with a high purity of 99.75%. The results of the X-Ray confirm the amorphous nature of the extracted SiO2 NPs. Also, the AFM results indicated that the average diameter of the SiO2 NPs was 85 nm. It was noted that the leaching processes and pretreatment methods determine the structure, particle size, and quality of the synthesized SiO2 NPs.

Many liquid storage tanks around the world have been affected by earthquakes, and the seismic analysis of such tanks is much more complicated due to the Fluid-Structure Interaction. Besides, when the soil properties are taken into the consideration, the analysis with the Fluid-Soil-Structure Interaction becomes very complicated. In this paper, a series of shaking table tests are conducted on a model of the cylindrical water tank rested on dry granular soil and the equivalent load is considered to study the effect of hydrodynamic pressure generated in the storage water tank on the soil behavior. An experimental investigation of (1:100) scale model has been carried out on a shake table that was manufactured with specific mechanical parts and flexible laminar shear box. The preparation of the test included three cases in different relative densities (medium, dense, medium-dense). Three earthquake histories (Kobe, El-Centro and Ali Al-Gharbi) were implemented to study a wide range of the acceleration. The results showed that the acceleration at the bottom-depth of the soil column is slightly higher than at the mid-depth, while at the top portion of the soil column, the acceleration comparatively becomes less than that at the mid-depth. The settlement due to hydrodynamic pressure in the storage base tank is significantly reduced compared with results of nonhydrodynamic pressure in all cases of the acceleration history. In addition, the lateral stress at the surface gives higher than the stress at a depth equal to the diameter of the base tank.

This study describes an experimental investigation of the thermal efficiency of stainless steel mesh and steel wool as a porous medium in the lower channel of a double pass solar air heater. An experimental setup was planned and developed. Various types of porous media with high thermal conductivity and with different porosities have been tested. The effects of the porosity of wire mesh, the thermal conductivity of porous media, mass flow rate, and the intensity of radiation have been studied. Experimental results show that thermal efficiency with using porous media is greater than without using porous media. When used steel wool as a porous medium, the thermal efficiency reached 79.82 percent while it can be achieved 76. The percent by using stainless mesh as porous material. The reduction in porosity increasing thermal efficiency. The thermal efficiency of multi-pass solar air collector when used steel wool as porous media is 6, 12.6 and31.7percent higher than without porous media at porosity 98.75, 97.5, and 96.25percent. While it can increase 8.1 and 28.5 percent at porosity 97.875 and 95.75 percent when using stainless steel as porous media.

The objective of the research presented in this paper is to investigate the buckling behavior of a perforated thin-walled lipped channel beam subjected to combined load. A nonlinear finite element method was used to analyze the buckling behavior of the beam. Experimental tests were made to validate the finite element simulation. Three factors with three levels for each factor were chosen to examine their influence on the buckling behavior of the beam and these factors are: the shape of holes, opening ratio ????????/???????????????? and the spacing ratio of ????????/????????????????. The finite elements outcome was analyzed by using Taguchi method to identify the best set of three-parameter combinations for optimum critical buckling load. The analysis of variance technique (ANOVA) was implemented to determine the contribution of each parameter on buckling strength. Results showed that the mode of buckling failure of the perforated beam is lateral-torsional buckling and the hexagonal hole shape, ????????/????????????????=1.7 and ????????/????????????????= 1.3 were the best combination of parameters that gives the best buckling strength. The results also showed that the shape of holes is the most influential on buckling behavior of the perforated beam for this case of loading.

Because cracks are the main problem of mass concrete, this paper investigates an experimental study on the effect of polypropylene microfiber (PPMFs) on self -repair behavior of mass concrete, through study the microstructure, workability, physical, and mechanical properties of mass concrete. PPMFs with a diameter of 18 μm add in different percentages (0, 0.5, 1 and 1.5) % of cement weight. Where the prepared mixture ratio was (1:2:4.8) and the water-cement ratio (W/C) was 0.4. Also, 0.6% of Superplasticizer (SP) % of cement weight to all concrete mixtures was added. In this study, an SEM analysis used to observe the effect of PPMFs on the microstructure of mass concrete, and compressive and flexural strength tests for study the mechanical properties of this. And referring to the analysis and discussion of the results, PPMFs used have changed the microstructure of mass concrete, and have an effective effect on improving compressive strength and flexural strength, and mechanism of sealing the cracks of concrete autogenously. Also, 1% PPMFs (% of cement weight) recorded as the highest addition, which has a positive effect on mass concrete properties to apply it in the construction field.

This paper studied the impact of the addition of pulse electric-filed low voltage (PEF-LV) in the filtration process by designing, constructing, and operating a pilot-scale. The Disinfectant process (DP) demonstrated several benefits in terms of efficiency and ease of application, without the use of any chemical additive. This system contains two pairs of silver mesh electrodes inside the filtration column test with a low pulse voltage for killing microorganisms. The parametric effects of DP performance, such as alternating current pulse frequency and the voltage applied were investigated. The effect of PEF-LV on the biological, physical, and chemical characteristic of water was studied. The transmission electron microscopy (TEM) was used to examine the change of the cell wall morphology of Escherichia coli, Staphylococcus aureus cells for influent, and treated water. The results show the removal efficiency of E. coli and S. aureus 96 % at 30 V and 0.5 Hz.

This paper presents a survey of some of the most recent research work on the extraction phase of the Iris recognition system. Iris biometric system has been used for person recognition in wide applications where person identity authentication required for its stability and uniqueness as compared to other biometric systems. Iris based recognition systems consist of stages are Iris localization, normalization, feature extraction, and matching. The extraction of features influences the precision and reliability of the biometric system, so several methods have been used.

In this work, the Upflow Anaerobic Sludge Blanket “UASB” reactor treated effluent wastewater to investigate the process performance on a pilot plant scale. Municipal wastewater at high and medium strength with different organic load rate OLR (0.6-9) kg COD m-3day-1 with the flow of 20 l/h, up-flow velocity 0.4 m/h, hydraulic retention time HRT 9 h at a temperature of (20-30 ºC) was evaluated. The wastewater concentration, including TSS, COD was measured, and the removal efficiencies of chemical oxygen demand (COD) and total suspended solid TSS were calculated and summarized as 45-85% and 70-75%, respectively, depending on organic load rate OLR. Effluent volatile fatty acids VFA was measured, and the results were in the range between 12-90 mg/L depending on OLR with a slight change in pH (8.3-8.4), which means the conversion of COD to methane and increase ammonia concentration.

This research revealed control on Nano fluid temperature in the evacuated tube solar collector system, where Nano fluids used in ETSC as working fluid to increase heating system thermal efficiency. Smart curtain was used to shadow the evacuated tube solar collector and to control the temperature of the Nano fluid in heating or cooling condition which is moved by the stepper motor which is programmed to move through the Arduino board using an artificial intelligence method such as (PSO based PID) controller method . Where the curtain's main idea is to control the polarization of the sun's radiation, the work of the curtain refers to the parameters: the first parameter is the Nano fluid temperature and the second is sun radiation falling on the collector, and one output parameter is defined by (distance parameter).

In this paper, the strength of aircraft sandwich structure with honeycomb core under bending load was evaluated theoretically and experimentally based on failure mode maps. A failure mode map for the loading under three-point bending was constructed theoretically to specify the failure modes and corresponding load. Three point bending test for aluminum honeycomb sandwich beam has been achieved to measure the peak load and maximum deflection. The obtained results elucidated a good agreement between the theoretical solutions and experimental tests, where the error ratio was not exceeded 12%. The core height, the cell size and the cell wall thickness were selected to explore the effect of honeycomb parameters on the strength of sandwich structure. In order to obtain the optimum solution of peak load and maximum deflection and energy absorption, Response Surface Methodology (RSM) was used. Results showed that the maximum bending load, minimum deflection, and maximum energy absorption were found at 25 mm core height, 10 mm size cell and 1 mm cell wall thickness. The optimal value of maximum bending load, minimum deflection and maximum energy absorption were 1975.3415 N, 1.0402 mm and 1.0229 J respectively.