European Journal of Technology and Design

10-19

Authors: Maria Musa Mukaddas, Umar Hassan, Fatima M. Abubakar, Ziyaulhaq Haladu

An appraisal of planning and control as management tool for optimum productivity on construction sites was assessed with the view of finding the various ways to establish the best alternative planning and control techniques for some particular kinds of projects. Questionnaires were distributed to professionals. Not all construction firms have a separate planning department, this means that they integrate the planning job into other department, and out of the 43 respondents, none had PhD, while majority had M.Sc. A minimum level of planning tools and procedure use is important but what kind of tools is of no importance. However, the most used planning technique for building projects is the Bar chart/Gantt chart and it was discovered that its choice was due to the reasons being that they are simple and easy to handle and manipulate, flexible and it graphically presents the activities with their start time and dates along with links and overlaps. It is suitable for all kinds of project irrespective of its size and nature. Planning tools like progress curve, line of balance, project evaluation and review techniques (PERT) are almost non-existence. The major challenge encountered on site when implementing the plan is delay in completion of the works and dispute does arise between the construction team. Most planners nowadays use computer Aided software to prepare and design their plan, and the major software used is Microsoft project among others. Furthermore, it encourages project managers to believe that although planning does not guarantee project success, lack of planning will probably guarantee failure. Finally, it was revealed from this research that planning is never an easy undertaking but it requires attention since it helps to achieve success. Similarly, Planning is considered a central element of modern project management, the assumption behind the position is that planning reduces uncertainty and increases the likelihood of project success.

26-32

Authors: Vo Quang Nha, Huynh Thi Thuy Linh, Nikolai I. Gorbachuk, Ngo Xuan Cuong

Recently, metal-oxide-semiconductor structures using silicon dioxide is the most common microelectronic structures. Silicon dioxide (SiO2) is used to isolate pole gate dielectric, and it is also the main material used to make stable, high-performance devices of integrated circuits. Electrical parameters at the Si-SiO2 interface created by gamma irradiation depends on the type and penetration of the implanted ions. The paper provides a method of determining the equivalent circuit of a metal-oxide-semiconductor structure to determine its electrical parameters. The structure Al/SiO2/n-Si irradiated by helium ions with energy 5 MeV at fluence 1012 cm-2 are studied to find its equivalent circuit. Result, the structure’s equivalent circuit composing of a resistor and parallel RC circuit in series does not describe the frequency dependence of the electric loss in an alternating current at the frequency range 20 – 3•106 Hz. In the inversion region with voltage U = -40 V, equivalent circuits are developed and implemented in a wide frequency range. These circuits allow us to easily calculate electrical parameters through the frequency dependence of impedance characteristics.