Al-Nahrain Journal for Engineering Sciences

Dynamic modeling of a robot manipulator is a central problem in an accurate robot control. In this paper; the dynamic equations of motion were derived by using Eular-Lagrange method for a six degree of freedom articulated robot manipulator based on the geometrical jacobian construction for each link and actuator. In addition, friction effects beside the end effector forces that act the environment are considered. A Matlab Simulink plant is developed to embrace the theoretical work and simulate the dynamic response for a designed nonlinear controller Proportional Derivative plus Gravity (PD+G), also a modified controller is applied to reject the disturbances and the internal friction effect where the settling errors were 3.57E-6, 2.09E-7, -3.63E-6, 8.84E-6, -5.39E-8 and -4.39E-5 (deg) for joints one to six respectively. The presented approach can be applicable to solve the dynamic problem of other n-link robot manipulators and achieve a suitable solution for tracking trajectories.

The purpose of this study is to reduce weight and improve the mechanical properties of aircraft wing using Hybrid materials known as fiber metal laminates (FMLs). In this study, seven layers were used to produce the FMLs that consist of aluminum alloy2024-T3 reinforced by carbon and glass fibers bonded with blend of epoxy-resole. The Carbon Glass Reinforced Aluminum Laminates (CAGRALLs) was used as FMLs. The results showed that The CAGRALLs gave good mechanical properties because of increasing in tensile strength, elongation at fracture and impact toughness except flexural strength by comparing with other FMLs using commercial epoxy. The increasing in layers led to weaken adhesion force between layers of FMLs caused decreasing almost mechanical properties. The FMLs has good mechanical properties by using carbon and glass fibers by comparing with carbon and jute fibers. The CAGRALLs have higher numbers of cycles at failure under cyclic loadings than Aramid Reinforced Aluminum Laminates (ARALLs). The CAGRALLs have lower density by comparing with aluminum alloy 2024-T3 that used in manufacturing of aircraft wing

This paper present glass waste material reusing in concrete as partial replacement of cement. Some hardened properties like compressive and flexural strengths, modulus of elasticity and % absorption was made. The effect of glass powder on these properties was examined compared to reference specimens without glass powder. Five percentage was tested: 0%(reference), 10%, 15%, 20% and 25%. From tests results one can conclude that replacing cement partially by glass powder enhanced strengths of concrete (compression and flexural) up to 20% replacing level Using glass powder as partial replacement of cement improved strengths and modulus of elasticity of concrete. The %absorption decrease with increasing of glass powder content. The results show that utilization of waste glass as powder in concrete can reduce amount of cement which save cost besides its environmental benefits.

Zinc oxide nano particles is one of the best choices for ultraviolet protection due to its special properties. In this research, the UV-protection ability of sol gel-derived thin ZnO films on cotton fabrics was investigated. Various polymers have been used as adhesives to bind the nano-oxide with the surface of the treated fabric. Scanning electron microscopy and UV spectroscopy were carried out to study the properties of the treated fabrics. The results showed that the diameters of the synthesis zinc oxide particles - (68.81, 41.76 and 44.6 nm) with (PVA, PVP and CMC) respectively- were of the nanostructure, and the smallest diameter of the particles was produced with polyvinylpyrrolidone as adhesive. Using a spectrophotometer showed a decrease in the transmittance of the studied samples compared with the raw untreated sample of about 23%.

The efficiency of the solar PV panel decreases significantly as the PV panel’s operating temperature increases. There are many cooling techniques might be suitably deal with this problem to enhance the solar panel efficiency. The presented cooling technique used for solving the PV panel’s temperature elevation is an active close loop cooling system, accomplished using two water glazing chambers made from acrylic glass placed at the PV panel surfaces (rear and front). These champers are utilized for cooling down the PV cell’s temperature, as well as filtering the useful sunlight spectrum. The results show that the PV cell’s temperature reduction by 50.06% with using the cooling system, this leads to an average increase in the maximum output power and consequently electrical efficiency of the PV panel by about 12.69% and 14.2%, respectively.

In this study sunlight and UV radiation were used to compare the efficiency of decolorization of textile wastewater containing brilliant reactive red dye K-2BP (λmax = 534 nm) by the advanced oxidation process (AOP) using (H2O2/sunlight, H2O2/UV, H2O2/TiO2/sunlight, and H2O2/TiO2/UV). The results studied the effect of solution pH, applied H2O2 concentration, TiO2 concentration (nanoparticle), and initial dye concentration were studied. The experimental results showed that decolorization percentage with H2O2/sunlight and TiO2/H2O2/sunlight under the following conditions: - reaction time 150 of minutes, [ 500 ppm] H2O2, [100 ppm] TiO2, pH=3, initial dye concentration =15 ppm and at ambient temperature were 95.7% and 98.42% respectively. For the same conditions using H2O2/UV, H2O2/TiO2 /UV, the percentage of decolorization were 97.85% and 96.33% respectively. The results also indicated that the sunlight is more economic and cost-effective than UV radiation.

This research deals with the subject of Built heritage attractions in Muslim historical building, for what it represents, as an element dealing with Cultural tourism, in the process of developing tourism industry of the city.
The location of Mustansiriya Madrassa in Baghdad’s commercial district could make it a profitable investment project to revive a cultural, artistic and tourist centre that could make it a cultural Tourism haven.
The problem emerges through, how the role of built heritage to attract tourists in order to give vitality and liveability to the cultural tourism destination such as Al - Mustansiriya Madrassa which is one of the most popular heritage destinations, a historic school building situated in the ancient Abbasid district of Rusafa in the very heart of Baghdad.
Therefore, the research's aim is to shed light on the heritage attraction as a mean to clarify the meaning of Cultural Tourism and specifying its definition.
This research explains how the built heritage plays an important role in tourism in general and in the cultural tourism in particular because they attract tourists and provides a sustainable economic resource through its inclusion of values that make it distinct from other sources of attraction.

Both surface extension and nanofluid methods were used to enhance the heat transfer in a double pipe heat exchanger under turbulent flow conditions. Aluminum oxide nanoparticles were used with different concentrations(0.6-3 g/l)in hot water to increase the heat transfer rate on smooth tube and circular fins tube for a range of Reynolds number4240-19790. The simulation was also performed to predict the heat transfer coefficient and temperature profile for selected conditions in which COMSOL Multiphysics is used. The experimental results revealed that the heat transfer enhancement by both circular fin and nanofluid exhibited an increasing trend with Reynolds number and nanofluid concentration. The conjoint effect of Al2O3 of 3 g/l concentration and circular fin provided largest heat transfer enhancement of 53% for the highest Re investigated. Simulation results showed reasonable agreement with the experimental values of heat transfer coefficient. The simulation showed that the presence of nanofluid on finned surface influenced the temperature profile indicating the increased heat transfer rate

Our proposed method used to overcome the drawbacks of computing values parameters in the mountain algorithm to image clustering. All existing clustering algorithms are required values of parameters to starting the clustering process such as these algorithms have a big problem in computing parameters. One of the famous clustering is a mountain algorithm that gives expected number of clusters, we presented in this paper a new modification of mountain clustering called Spatial Modification in the Parameters of Mountain Image Clustering Algorithm. This modification in the spatial information of image by taking a window mask for each center pixel value to compute distance between pixel and neighborhood for estimation the values of parameters σ, β that gives a potential optimum number of clusters requiring in image segmentation process. Our experiments show ability the proposed algorithm in image brain segmentation with a quality in the large data sets