Aniline effect on concrete steel rebar degradation in saline and sulfate media

Electrochemical potential monitoring experiments were performed on mild steel rebars embedded in concrete admixed with aniline inhibitor and fixed amount of sodium chloride salt partially immersed in sulfuric acid and sodium chloride solution. The open circuit potential corrosion monitoring technique was employed and the potential readings were taken in accordance with ASTM C 876. Repressive attribute and consistency of the inhibitor was then estimated by the Weibull probability density distribution as an extreme value statistical modeling approach to study performance effectiveness and to predict the most efficient inhibitor concentration in each media. Aniline effect on the compressive strengths of the reinforced concrete samples was also investigated and reported. Varying concentrations of the inhibitor were used and its performance improved as concentration changed in NaCl medium, while no particular order of performance was noted in sulfuric medium. In the statistically analyzed experimental results for each of the inhibitor concentrations employed, 0.34 and 0.41 M aniline admixed samples were identified as exhibiting the best inhibiting quality in sodium chloride while 0.14 M aniline was predicted as showing the lowest probability of corrosion risk in sulfuric acid medium. The overall effective inhibitive performance in sulfuric acid was less when compared to the sodium chloride medium. Concrete sample admixed with 0.41 M aniline had the highest improvement in compressive strength in both media

Analytical Modelling of Human Arm Locomotion during Dance as a Dynamical Multiple Pendulum System

During dance human arms move. The movement of the arms, to a large extent, determines how good a dance is. This paper attempts to model the locomotion of human arm, analytically, during a dance as a dynamical multiple pendulum system with three segments. The system is analyzed by considering some instances during the dance. The three angles the three segments make with the vertical are considered. The Euler-Lagrange equation is used in obtaining the equation of Motion. The resulted second order differential equation is solved analytically. Simulation results are presented. They are consistent with the ones in literature. Specifically the angular displacement values of the three segments are directly proportional to their respective angular acceleration. However, the novelty of this work is in the full analytical approach to 3-pendulum system and its application to danc

Assessment of geomorphic and morphometry characteristics of parts of Shasha and Opa river basins in Obafemi Awolowo University Campus, Southwestern Nigeria

Geomorphic and morphometry characteristics of parts of Shasha and Opa Basins in Obafemi Awolowo University campus, Ile-Ife, southwestern Nigeria were assessed through the analysis of basin linear, areal and shape parameters with a view to quantitatively describe the hydrological characteristics of the area. The campus is drained by Rivers Shasha and Opa and their tributaries. Stream order, stream number, stream length, mean stream length, stream length ratio, length of over land flow, confluence factor, form factor, elongation ratio, stream segment density, drainage density, drainage texture and slope within the campus were determined through the evaluation of topographic, drainage, and land use and land cover maps. The campus is drained mostly by River Opa (4th order channel) and its tributaries while the remaining part (i.e. northeastern and northwestern parts of the campus) is drained by River Shasha (3rd order channel) and its tributaries. The mean 1st, 2nd and 3rd stream orders of River Shasha were 0.42, 0.54 and 1.03 km, respectively; while the mean stream length for the 1st , 2nd , 3rd and 4th stream orders of River Opa were 0.40, 0.64, 1.84 and 4.07 km, respectively. The average length of overland flow within the Shasha sub-basin was 0.25 km, while the average - length of overland flow within the Opa sub-basin was 0.15 km. Stream segment density increased from 0.16 km to 3.18 km in River Shasha and 0.08 km to 4.33 km in River Opa. Increased stream segment density from lower to higher stream order could have been influenced by increased fracture control of streams from lower to higher stream order. The predominant trend of the streams were NE-SW and NW-SE, suggesting the influence of differing lithologies or tectonic activities, where streams must have developed by taking advantage of the local relief for the varying stream flow directions

Dynamic Response of Inclined Isotropic Elastic Damped Rectangular Mindlin Plate resting on Pasternak Foundation under a Moving Load

In this article, the dynamic behavior of inclined damped rectangular Mindlin plate under the influence of moving load along the mid-plate on the plate surface is considered. A numerical method is used to solve the nondimensional form of the resulting coupled partial differential equations. The desired solutions are obtained with the aid of computer program developed in conjunction with MATLAB. It is observed that the response amplitude of the plate is affected significantly by the foundation moduli. Also, the effects of the shear deformation, rotatory inertia, damping and angle of inclination of the plate, to the horizontal, are noticeable

Vibration Analysis of the Low Speed Shaft and Hub of a Wind Turbine Using Sub Structuring Techniques

The wind turbine vibration causes dynamic instability of components of the transmission system desired to generate electricity. The vibration motion of the hub relative to the shaft need to be studied in order to improve durability of components part and ensure that a good percentage of wind energy captured is transmitted to electricity. This paper attempts to do that. A sub-structuring technique was adopted in the analysis of the vibration motion. Firstly, the finite element equation was derived for the hub and shaft structures before coupling. After coupling, the appropriate boundary condition was used to minimize the system complexities. The solution to the eigenvalue problem was then developed using MATLAB. This results obtained show that sub-structuring is a suitable technique for the dynamic analysis of the transmission system of a wind turbine as compared with other approaches

Dynamic Modeling and Analysis of Inverted Pendulum using Lagrangian-Differential Transform Method

There has been an increase in application of pendulum in robotics which is applicable in Medicine, Agriculture, Military, Industries Explorations and Entertainment. Many Researchers have shown interest in inverted pendulum stability and control in recent years. This study is concerned with the development of equation of motion of inverted pendulum and its analysis by adopting the Lagrangian and Differential Transform Method (DTM) respectively. The resulting equations were solved analytically. Results obtained are consistent with the ones in the literatur

Lagrangian-Analytical Modelling of Damped Quintuple Pendulum System

Quintuple pendulums are an extension of the chaotic double, triple and Quatertuple pendulums problems. In this paper, a planar compound quintuple pendulum was modelled with viscous damping forces. Using Lagrangian energy methods, we derive coupled ordinary differential equations of motion for the system and submit them to analytical manipulation to model the dynamics of the system. We obtain the simulated results. The inclusion of damping in the system has significant effect on the dynamics, highlighting the system's chaotic natur