International Journal of Engineering
Volume:18 Issue: 1, Apr 2005

The amount of petroleum hydrocarbon and heavy metals in sediment of Persian Gulf’s shore at 8 selected stations were determined and showed the maximum of 143.6 and 58.6 mg/kg sediment, respectively. The above maximum amounts were related to Emam Hassan zone which is located at 50 kilometers to west Boushehr port. Bioremediation of contaminated sediment were studied in slurry and solid state fermentation. 8 bacteria types were isolated. Four species Em2, SH, GN1 and GN3 presented maximum PAH (Poly Aromatic Hydrocarbons) removal efficiency. Biodegradation efficiency under slurry conditions was observed after about 45 days which during this period, naphthalene and phenanthrene showed 73 and 66% removal efficiency, respectively. Under solid-state conditions, microbial activity of mixed and pure culture was studied. The results presented that the mixed culture due to strength and tolerance of different strains for growth, showed higher degradability compared to pure strains, but due to insufficient mixing under solid state conditions, mass transfer rate of nutrient reduced which caused to reduce cell activity, therefore removal efficiency under slurry conditions was higher.

This paper presents the results of a study on the axial compressive strength of columnsstrengthened with FRP wrap. The experimental part of the study included testing 6 reinforcedconcrete columns in two series. The first series comprised three similar circular reinforced concretecolumns strengthened with FRP wrap. The second series consisted of three similar square columns,two with sharp corners, and the other with rounded corners. Axial load and displacement of columnswere recorded during tests using a displacement control test set up. Test results are compared with thevalues calculated using CSA (Canadaian Standard Association) Code provisions and recent proposedequations. It is shown that the FRP wrap increases the strength and ductility of circular columns,significantly. The recent proposed equations correlate well with the test results of circular and squarecolumn with rounded corners. According to the test results, the FRP wrap did not increase thestrength of square columns with sharp corners. However, the square column with rounded cornersexhibited a higher strength and ductility compared to those with sharp corners.

Web of plate girders in bridges are usually reinforced by welded transverse stiffeners inorder to improve their shear capacity. Due to problems associated with field welding and fatigue,welded stiffeners are not suitable for retrofitting existing bridges. Bolted stiffeners are a practicalalternative for strengthening girders that are expected to experience shear stresses in excess of theirdesign shear capacity. This paper presents the results of an analytical study into behavior of plategirders with bolted transverse stiffeners. Based on this study new requirements are developed fordesign of such girders.

A two dimensional numerical model of shallow water equations was developed tocalculate sub and super-critical open channel flows. Utilizing an implicit scheme the steady stateequations were discretized based on control volume method. Collocated grid arrangement was appliedwith a SIMPLEC like algorithm for depth-velocity coupling. Power law scheme was used fordiscretization of convection and diffusion terms. Under relaxation factors were introduced in themodel to prevent divergence. Momentum interpolation was used in calculating velocities on cell facesto avoid checker board water surface fluctuation in the collocated grid. The model was verified indifferent cases including complex water surface profiles and hydraulic jump. The results arecompared with experimental and analytical data and the necessary values of under relaxation factorsfor a converged solution are discussed. No artificial viscosity was required, which is the advantage ofthe present model.

Automatic Meter Reading (AMR) is the remote collection of consumption data from customer’s utility meters over telecommunications, radio, power line and other links. AMR provides water, electric and gas utility service companies the opportunity to streamline metering, billing and collection activities, increase operational efficiency and improve customer service. The AMR system consists of three major components: the meter interface module, communications system, and data concentrator. This paper details with a feasibility study on creation of a robust bi-directional/two-way communication system between an electricity meter and a distant control unit (data concentrator) over the low voltage (LV) distribution grid. Basic functions of the AMR system include the provision for remote connection and disconnection of meter and fraud detection features at both the meter interface and the data concentrator. As a support system to the entire AMR, Lithium-ion batteries are utilized which are especially important in the cases of power failures. The main advantage of this system is that it is a low cost system that produces very encouraging results and it can be implemented upon existing electro-mechanical meters without the need of purchasing new meters. With many existing meters being the electro-mechanical meters, the need for a high-cost, large-scale implementation of new electronic device meters to enable implementation of the AMR system is unnecessary. The cost of implementation is low and the benefits, especially economically, that it brings to the utility company are immense.

A resource investment problem is a project-scheduling problem in which the availability levels of the resources are considered decision variables and the goal is to find a schedule and resource requirement levels such that some objective function optimizes. In this paper, we consider a resource investment problem in which the goal is to maximize the net present value of the project cash flows. We call this problem as Resource Investment Problem with Discounted Cash Flows (RIPDCF) and we develop a heuristic method to solve it. Results of several numerical examples show that the proposed method performs relatively well.