ORIGINAL_ARTICLE
Bioremediation of Sediment in Persian Gulf Coast (RESEARCH NOTE)
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.
https://www.ije.ir/article_71559_85112cdf9c1f3b026cb5c7e950e535a5.pdf
2005-04-01
1
8
Hydrocarbon Pollutant
Heavy metal
Persian Gulf Coast
Bioremediation
Solid Phase Bioreactor
P.
Moslehi
moslehi@sharif.edu
1
Chemical & Petroleum Engineering, Sharif University of Technology
AUTHOR
M.
Vossoughi
vosoughi@sharif.edu
2
Chemical and Petroleum Engineering, Sharif University of Technology
AUTHOR
Iran
Alemzadeh
alemzadeh@sharif.ir
3
Chemical Engineering, Sharif University of Technology
AUTHOR
ORIGINAL_ARTICLE
Design Requirements for Plate Girders with Bolted Transverse Stiffeners (TECHNICAL NOTE)
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.
https://www.ije.ir/article_71566_1346b50627d1ebc3a7cd41dfed56daf2.pdf
2005-04-01
21
26
bridge
Building
Plate Girder
Plate Buckling
Stiffener
Shear strength
A.
Vasseghi
vasseghi@iiees.ac.ir
1
Civil Engineering, International Institute of Earthquake Engineering
AUTHOR
ORIGINAL_ARTICLE
Development of an Implicit Numerical Model for Calculation of Sub and Super Critical Flows
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.
https://www.ije.ir/article_71568_ebd381532e982f13738d0e68de1bd0c8.pdf
2005-04-01
27
38
Shallow
Water
Under
relaxation
Sub
Critical
Super
Implicit
Numerical Model
M.
Eftekhari
hasnomail@ije.ir
1
Civil Engineering, Amirkabir University of Technology
AUTHOR
A.R.
Zarrati
zarrati@aut.ac.ir
2
Civil & Environmental Engineering, Amirkabir University of Technology (Tehran Polytec
AUTHOR
M. R.
Hadian
mr_hadian@yazd.ac.ir
3
Civil Engineering, Yazd University
AUTHOR
ORIGINAL_ARTICLE
Pic Microcontroller-Based Automatic Meter Reading (AMR) System Using the Low Voltage (LV) Power Line Network (TECHNICAL NOTE)
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.
https://www.ije.ir/article_71572_f66ee5d65bce866c6be5636c64f21442.pdf
2005-04-01
39
50
PLC
AMR
electromechanical meter
PIC
fraud detection
S.Y.
Tan
hasnomail@ije.ir
1
Electerical Engineering, University of Malaya
AUTHOR
M.
Moghavvemi
mahmoud@um.edu.my
2
Electerical Engineering, University of Malaya
AUTHOR
ORIGINAL_ARTICLE
Resource Investment Problem With Discounted Cash Flows
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.
https://www.ije.ir/article_71574_6908d8cdfbff6a13e818e3c12e03c7cc.pdf
2005-04-01
51
62
Project scheduling
resource investment
Net Present Value
Heuristic methods
S.T.A.
Niaki
niaki@sharif.edu
1
Industrial Engineering, Sharif University of Technology
AUTHOR
A. A.
Najafi
aa_najafi@yahoo.com
2
Chemical & Petroleum Engineering, Sharif University of Technology
AUTHOR