Abstract: Preparation of Alpinia galanga agro waste-high density polyethylene (HDPE) composites involved the addition of eco degradant and polyethylene-g-maleic anhydride (PE-g-MA). The Alpinia galanga agro waste fibers at 3, 6, 10 and 15 wt% were compounded in an internal mixer with the addition of 5 wt% MA-g-PE and eco degradant. The composite specimens were prepared using an injection molding machine. The results show that the maximum tensile strength of 33 MPa was obtained for sodium hydroxide (NaOH) & 3-aminopropyltriethoxysilane (3-APE) treated fiber composites with eco degradant and MA-g-PE at 15 wt% fiber loading compared to that of pristine HDPE (28 MPa). All the treated composites show an improvement in tensile strength. This indicates that the treatments using NaOH&3-APE and p-toluenesulfonic acid (PTSA) with addition of eco degradant and PE-g-MA improved adhesion between Alpinia galanga fiber and HDPE matrix. The Scanning Electron Microscopy (SEM) micrographs show the presence of a improved interaction between treated Alpinia galanga fibers and HDPE matrix with the addition of eco degradant and MA-g-PE. Thermal stability of composites was also improved for composites with treated fibers.
Abstract: A model-inspired phenomenology constitutive equation was developed from the first principles to study the temperature dependence of flow stress at confined dimension. The model was limited in the range of temperature and strain-rate where diffusion is insignificant. It was assumed that flow stress was predominantly governed by the thermal activation of dislocation lines overcoming short-range barriers. A simple sound model was developed from the established principles. Data from relevant experiments were fitted into the model to evaluate and reveal key parameters. Normalization of the data and linearization of the model were performed prior to the evaluation and analysis. The proposed models were generally well fitted to the experimental data as indicated by the correlation factors of >0.85, which could be principally accepted by the criteria of R2=0.90. Of the candidate models, Model III and Model I are particularly recommended to study the temperature-dependent behavior of Cu at confined dimension in the space of interest related to the intended applications (2<TM/T<5). Physical mechanistic re-interpretation of the models for the problem of interest is presented in the second report (Part II).
Abstract: This contribution deals with a new analysis of a rigid body manipulation system. It is based on the well–knowngeometric control of system dynamics. In such a framework some typical problems in robotics are mathematicallyformalized and analyzed. The outcomes are so general that it is possible to speak of structural properties in roboticmanipulation. The problem of non-interacting force/motion control is investigated. A generalized linear model is usedand a careful analysis is made. The main result consists in proposing a task–oriented choice of the controlled outputs,for which the structural non-interaction property holds for a wide class of manipulation systems. Moreover, a decoupledlinear model predictive control is proposed which uses a pre-selecting matrix to speed up the dynamics of the mechanisms.The pre-selecting matrix enables to considers subspaces which correspond to the eigenvectors of decoupled system tospeed up the dynamic of the considered mechanism.
Abstract: The study of heavy vehicle forces on pavement is important for both vehicle and pavement. Indeed it was identified several factors such as environment, materials and design consideration affects pavement damage over time with traffic loads playing a key role in deterioration. Therefore, this paper presents dynamically varying tire pavement interaction load, thus enable to assess the strain response of pavements influenced by road roughness, truck suspension system, variation of axle loading and vehicle speed. A 100m pavement with good evenness was simulated to check the sensitivity of the dynamic loads and heavy truck vertical motions to the roughness. The most important performance indicators that are required in pavement distress evaluation are radial strain at the bottom of the asphalt concrete and vertical strain at the subgrade surface was predicted using peak influence function approach. The results show that truck speed is the most important variables that interact with truck suspension system and thus effect of loading time are extremely important when calculating the critical.
Abstract: This paper discusses the application of Magneto-rheological (MR) for motorcycle suspension. Previous studies on the usage of the MR fluids could enhance the performance and improved the vibration in systems such as buildings and vehicles. Therefore, MR motorcycle suspension system is proposed and investigated here by using Bouc-wen model. It is designed to bring comfort and safety to both rider and passenger also to improve the handling ability to the motorcycle. The effectiveness between the MR motorcycle suspension and the passive system is demonstrated by computer simulation. It is found that MR suspension system could eliminate external disturbance which obtain much better ride quality and handling performance to the motorcycle.
Abstract: In this paper, statistical quantities of a fully pulsed round jet along the jet centerline are reported. A range of the Reynolds (1.5 x 104 < Re < 4 x 104) and Strouhal (0.0064 < St < 0.0076) numbers is used to generate the jet. Physically this unsteady jet produces a series of distinct pulses due to the excitations. The mechanically excitations lead to the appearance of pulse dominated and high turbulence steady jet region in which their existence is of a strong dependence on the level of the controlled parameters. After the pulse merging completes the pulsed jet alters to a self-preserving steady jet with a significantly higher turbulence intensity. Under a constant mass flow rate the pulsed jet tends to be more fluctuating at a less intense pulsation thus permitting the endurance of the normalized periodic component and a more rapid velocity decay in the pulse-dominated region.
Abstract: This paper will cover the development of Adaptive secondary skin system. Adaptation is essential to managing the problem of climate change. In order to meet this growing challenge, the system will propose a new generation of secondary skin that optimize their configuration in real time by responding to environmental. Performance-based technologies in architectural element have barely lived up to their full potential. The secondary skin system is developed using kinetic object method that could generate changeability in its shape, pattern, and orientation that was controlled by actuators. These actuators received inputs from surrounding environmental data. Furthermore parametric tools, sensors, and environmental modeling was used to create truly dynamic and responsive secondary building skin.
Abstract: A novel method based on numerical continuation algorithm for equilibria and stability analysis of nonlinear dynamical system is introduced and applied to an aircraft vehicle model. Dynamical systems are usually modeled with differential equations, while their equilibria and stability analysis are pure algebraic problems. The newly-proposed method in this paper provides a way to solve the equilibrium equation and the eigenvalues of the locally linearized system simultaneously, which avoids QR iterations and can save much time.
Abstract: Inverse Kinematics solutions are needed for control of robotic manipulators for successful task execution. It is the process of obtaining the required manipulator joint angle values for a given desired end point position and orientation. In general the process of obtaining these joint angle values is a complex process that may require some higher computational power in the hardware. Mainly there are three traditional methods used to solve inverse kinematics problem, namely; geometric methods, algebraic methods and iterative methods. Apart from these traditional techniques researchers have looked into the use of Artificial Neural Networks (ANNs). In this paper we re-visit these non-traditional techniques and compare the advantages and disadvantages of each method.