ORIGINAL_ARTICLE
Dairy Wastewater Treatment using Three-Stage Rotating Biological Contactor (NRBC)
Dairy wastewater is enriched in organic matter (about 45-72 g/l, COD) and also contains biodegradable carbohydrates. A three-stage system, NRBC was fabricated as a bench scale unit for lab experiments, to remove organic carbon from the whey. The fabricated NRBC had several advantages, such as quick start-up, high biomass concentration and was additionally able to handle high organic loading rates. In this study, the COD removal efficiencies of 80 and 83 percent were achieved at HRT of 16 and 24 h, respectively. While the HRT was increased to 36 h, the COD removal efficiency was increased to 92 percent. High surface COD loading rate of 38-210 g COD/m2.day was achieved. The high organic loading rate of whey was successfully treated in the fabricated NRBC. The COD removal efficiency of 96 percent was achieved, while the discs surface was increased by 10 percent.
https://www.ije.ir/article_71769_b9e5770c7ca31067f3815ba077b12016.pdf
2009-08-01
107
114
Whey
Dairy Wastewater
RBC
COD removal
Ghasem
Najafpour
ije.editor8@gmail.com
1
Biochemical & Chemical Engineering, Noshirvani University of Technology, Babol
AUTHOR
M.
Asadi
asadi.mostafa@gmail.com
2
Civil Engineering, University of Mazandaran
AUTHOR
A.
Ebrahimi
atieh.e@gmail.com
3
Civil Engineering, University of Mazandaran
AUTHOR
ORIGINAL_ARTICLE
Elastico-Viscous Flow between Two Rotating Discs of Different Transpiration for High Reynolds Numbers (RESEARCH NOTE)
The flow in an elastico-viscous fluid between two co-axial infinite rotating porous discs is considered for high cross flow Reynolds number. The discs are rotating with different angular velocity and the injection rate of the fluid at one disc is different from the suction rate of other disc. The effect of suction parameters on the velocity components have been investigated numerically and solved by iterative methods/finite difference methods and depicted graphically. This study has immense practical utility especially when the fluid is non-Newtonian. The results are applicable in the chemical industry using fluids of higher Reynolds numbers.
https://www.ije.ir/article_71770_a4961b04d8e1430439f2568b110fa3ff.pdf
2009-08-01
115
122
Elastico
Viscous
Porous medium
Reynolds Number
Ravindra Kumar Singh
Rajput
narendra_ibsmaths@yahoo.com
1
Computer Engineering, Govind Ballabh Pant University Of Agriculture and Technology
AUTHOR
Anjali
Pant
drapgpcn@gmail.com
2
Mathematics, GPCN
AUTHOR
N.
Kumar
drnk.cse@gmail.com
3
Mathematical / Computer Science and Engineering, Poornima University, Jaipur, India
AUTHOR
ORIGINAL_ARTICLE
Recovery of Methyl Acetoacetate from Antibiotic Production Plant\\\'s Waste Streams (TECHNICAL NOTE)
Chemical recovery of methyl acetoacetate from the amoxicillin plant’s waste stream was investigated. In process of amoxicillin production for activation of amoxicillin molecule, hydrolysis takes place at final stage. As a result methyl acetoacetate is formed. Liquid-liquid extraction was employed for the recovery of methyl acetoacetate from the waste stream. Diluted alkaline solution was used as an extractive agent for the chemical extraction process. Extraction was carried out while the pH was adjusted to 9.5 by addition of alkaline solution. The extraction was repeated in three consecutive stages to enhance the process yield. Finally, distillation was carried out to remove the volatile compounds residues. Samples were taken from each stage of separation for GC analysis. The recovered methyl acetoacetate with purity of 93 % and yield of 75 % was obtained from extraction and distillation processes.
https://www.ije.ir/article_71772_9483f0416b5566dac8d9cd4b7b595360.pdf
2009-08-01
123
129
Amoxicillin Plant
Extraction Process
Methyl Acetoacetate
Alkaline Solution
distillation
Ghasem
Najafpour
ije.editor8@gmail.com
1
Biochemical & Chemical Engineering, Noshirvani University of Technology, Babol
AUTHOR
Maedeh
Mohammadi
m.mohammadi@nit.ac.ir
2
Chemical Engineering, Babol Noshirvani University of Technology
AUTHOR
Ali Asghar
Ghoreyshi
aa_ghoreyshi@nit.ac.ir
3
Chemical Eng., Babol Nooshirvani University of Technology
AUTHOR
ORIGINAL_ARTICLE
Flexural Testing of High Strength Reinforced Concrete Beams Strengthened with CFRP Sheets
The objective of this study is to investigate the effectiveness of externally bonded CFRP sheets to increase the flexural strength of reinforced high strength concrete (HSC) beams. Four-point bending flexural tests to complete failure on six concrete beams, strengthened with different layouts of CFRP sheets were conducted. Three-dimensional nonlinear finite element (FE) models were adopted by ANSYS to examine the behavior of the test beams. More specifically, the strength and ductility of the beams is investigated, as the number of FRP layers and tensile reinforcement bar ratio changed. With the exception of the control beam, one to four layers of CFRP were applied to the specimens. The ductility characteristics of the test beams were evaluated in terms of the displacement, curvature and energy ductility index. It was found that for all the reported beams, the energy ductility value is about two times higher than the displacement ductility values. The crack patterns in the beams are also presented. The load deflection plots obtained from numerical study show good agreement with the experimental results.
https://www.ije.ir/article_71775_09a0693d89efa9f94b41ce780370e38e.pdf
2009-08-01
131
146
Ductility
Finite element model
FRP
high strength concrete
A. A.
Maghsoudi
maghsoudi.a.a@mail.uk.ac.ir
1
Civil Engineering, Shahid Bahonar University of Kerman
AUTHOR
Reza
Rahgozar
rahgozar@mail.uk.ac.ir
2
Civil Engineering, Shahid Bahonar University of Kerman
AUTHOR
seyed hamid
hashemi
hamidhashemi55@yahoo.com
3
Engineering, Arak University
AUTHOR
ORIGINAL_ARTICLE
Computation of Earthquake Response via Fourier Amplitude Spectra
A theoretical relation is presented between the seismological Fourier amplitude spectrumand the mean squared value of the elastic response, which is defined by Gaussian distribution. Byshifting a general process to its mean value, spectrum of the mean squared value of the displacementis computed from the Fourier amplitude spectrum and the real part of the relative displacementtransfer function of the single-degree-of-freedom elastic oscillator. It is shown that the relationpresented in this work opens the door for a better understanding of the relationship between timeinvariantmean squared value of linear response of a single degree freedom system and seismologicalvariables, such as magnitude, focal distance, and path and soil conditions. For illustrating theproposed theoretical relation, the mean squared values of a drift have been calculated for earthquakeground motions with different magnitude, focal distance and soil.
https://www.ije.ir/article_71777_fc063bb4c3b24dbb420d072107566b22.pdf
2009-08-01
147
152
Response
Frequency Domain
Seismological Method
Soil Condition
Azad -
Yazdani
a.yazdani@uok.ac.ir
1
Engineering, University of Kurdistan
AUTHOR
Yunes
Komachi
yns_61@yahoo.com
2
Civil Engineering, University of Kurdistan
AUTHOR
ORIGINAL_ARTICLE
Fabrication and Characterization of a New MEMS Capacitive Microphone using Perforated Diaphragm
In this paper, a novel single-chip MEMS capacitive microphone is presented. The novelties of this method relies on the moveable aluminum (Al) diaphragm positioned over the backplate electrode, where the diaphragm includes a plurality of holes to allow the air in the gap between the electrode and diaphragm to escape and thus reduce acoustical damping in the microphone. Spin-on-glass (SOG) was used as a sacrificial and isolating layer. Back plate is mono crystalline silicon wafer, which is much stiffer. This work will focus on the design, fabrication and characterization of the microphone. The structure has a diaphragm thickness of 3 μm, with 0.5 x 0.5 mm2 size and an air gap of 1.0 μm. The results show that, the pull-in voltage is 105 V, the initial stress of evaporated aluminum diaphragm is around 1500 Mpa and the zero bias capacitance of microphone is 2.12 pF. Compared with the previous works, this microphone has several advantages: The holes have been made on the diaphragm, therefore there is no need for KOH etching to make the back chamber, in this way the chip size of each microphone is reduced. The fabrication process uses minimum number of layers and reduces the fabrication cost.
https://www.ije.ir/article_71778_24fb493a353e5354ddfaee04e825d180.pdf
2009-08-01
153
160
MEMS Microphone
Perforated Diaphragm
SOG Sacrificial Layer
Silicon Backplate
bahram
azizollah Ganji
baganji@nit.ac.ir
1
Electrical Engineering, Babol University of Technology
AUTHOR
Buranuddin
Yeop Majlis
burhan@vlsi.eng.ukm.my
2
IMEN, UKM
AUTHOR
ORIGINAL_ARTICLE
Pulse Reverse Electrodeposition of Spherical Ni-MWCNT Composite Skein
Watt’s bath and pulse reverse (PR) electrodeposition is used to produce spherical nickelmultiwall carbon nanotubes (Ni-MWCNT) of 2.00, 0.93, 1.63 and 6.71 μm diameter and a variety ofsize distributions. For 60 cycles, an absolute electrodeposition current of 18 A/dm2 is applied atcurrent ratios of ii = idissolution/ideposition = 0, 0.077, 0.200 and 0.368. A simple exponential equation isfitted to each pulse response by a resistance-capacitance (RC) simple model giving different timeconstants usable for diagnosing the effect of different parameters. Results show that PRelectrodeposition is capable of producing microspherical Ni-MWCNT composite skeins of differentdiameters and size distributions. This could be identified with the time constant of the process.
https://www.ije.ir/article_71780_d6ebe15bdc9e1807d54ab4076ffb529a.pdf
2009-08-01
161
168
Ni Composite
MWCNT
Spherical Skein Composite
Pulse Reverse Electrodeposition
S.K.
Sadrnezhaad
1
Materials Science and Engineering, Sharif University of Technology
AUTHOR
Mehdi
Attarchi
attarchi@gmail.com
2
Surface Science, Merc
AUTHOR
ORIGINAL_ARTICLE
Structural Evolution of Al-20% (wt) Al2O3 System during Ball Milling Stages
Production of nanostructured aluminum matrix composite powder by high energy ball milling is investigated. Scanning electron microscopy analysis as well as the tap and green density measurements were used to optimize the milling time needed for the completion of the mechanical milling process. Also, we studied the particles morphology and size distribution change with milling time and its correlation with pressability and tap density. SEM showed that distribution of alumina particles in the Al matrix reaches a full homogeneity after the steady state. This would increase the hardness of powder due to a nano-structured matrix and oxide dispersion strengthening.
https://www.ije.ir/article_71782_e9488b014a1d523fbdd4e4e3f74db0b0.pdf
2009-08-01
169
178
metal
Matrix Composites
Nano
Structured Materials
Steady state
A.
Kazemzadeh
asg642001@yahoo.com
1
Semiconductors Department, Materials and Energy Research Center
AUTHOR
M. R.
Rahimipour
rahimi40@yahoo.com
2
Materials Engineering, Merc
AUTHOR
E.
Salahi
e-salahi@merc.ac.ir
3
Department of Engineering, Materilas and Energy Research Cenyer (MERC) P.O.B
AUTHOR
R.
Yazdani
ryazdani5@yahoo.com
4
Materials Engineering, MERC
AUTHOR
Seyed Salman -
Razavi Tousi
s-razavitoosi@merc.ac.ir
5
Materials Engineering, Merc
AUTHOR
Mansour
Razavi
m-razavi@merc.ac.ir
6
Materials Engineering, MERC
AUTHOR
ORIGINAL_ARTICLE
Thermodynamic Evaluation of Adsorption of Zinc Complex and ZnO Nano-Layer Prepared by TSCD Method Based on Langmuir Adsorption Model
Zinc oxide thin films were deposited on soda-lime glass substrates from an aqueous zinccontaining complex by two-stage chemical deposition (TSCD) method. Longmuir adsorption model showed that the adsorption of atoms on the surface of the substrate was typically physical. The relation between the fractional coverage, θ, with the equilibrium constant of the adsorption reaction was nonlinear indicating that the adsorption was non-ideal. The percentage of porosity, 1-θ, of the thin layer was determined as a function of Zn2+ concentration of the solution. By application of XRD technique, it was shown that pure crystalline ZnO of controllable thickness could be deposited by TSCD method on the surface of the substrate. The procedure consisted of immersion into (a) cold Zn2+ complex containing solution and (b) hot water at 90, 95 and 98°C.
https://www.ije.ir/article_71783_2310498aec7774aef94e380d6fb625dc.pdf
2009-08-01
179
184
Zinc oxide
Langmuir Adsorption
physisorption
Immersion
TSCD
S.K.
Sadrnezhaad
1
Materials Science and Engineering, Sharif University of Technology
AUTHOR
M.R.
Vaezi
vaezi9016@yahoo.com
2
Nanotechnology and Advanced Materials Department, Material and Energy Research Center(MERC)
AUTHOR
ORIGINAL_ARTICLE
Influence of Afterbody and Boundary Layer on Cavitating Flow
The characteristics of a cavitation water tunnel test setup and the experiments of cavitation around different models are given in this paper. Models of test are formed from combination of head and variable length afterbody. The experiments are performed initially with the smooth head and then with the roughened head. Cavitation initiates both in the wake and after the head. If the nose of models is roughened then cavitation initiates at the lower cavitation numbers. The cavitation inception is a function of the model geometry, nose condition and upstream flow characteristics. During the measuring process of drag force from non-cavitating flow regions to supercavitation case, only the tunnel pressure is reduced continuously. All measurements are performed at several Reynolds numbers. After cavitation inception in the wake, drag force increases continuously and fast. When cavitation initiates at the end of head, the mentioned force is maximum value and then decreases gradually. Supercavity is specified and compared with wedge case. The choking flow case is investigated around the models completely.
https://www.ije.ir/article_71785_88b35aa2a845235f40b4334a81baa18c.pdf
2009-08-01
185
196
Cavitation Inception Regions
cavitation number
Drag force
Choking Flow
Roughened Head
Supercavity Shape
Boundary Layer Thickness
Iraj
Jafarigavzan
jafarigavzan@mech.sharif.edu
1
Mechanical Engineering, Sharif University of Technology
AUTHOR
M.
Rad
rad@sharif.edu
2
Department of Mechanical Engineering, Sharif University of Technology, Tehran, Iran
AUTHOR
ORIGINAL_ARTICLE
Redistribution of Fibers in the Structure of Hollow Ring Spun Yarn
Core yarn was spun by introducing a PVA multifilament as the core through the yarn forming zone of a ring spinning frame and viscose fibers as the sheath containing tracer fibers. The water soluble PVA multifilament was extracted from the yarn structure. Then internal structure and properties of the hollow ring yarn was assessed and compared with those of typical ring yarns. Also, two plain fabric samples with hollow and typical weft ring yarns were produced to investigate the effect of hollowness and fibers collapse on the structural parameters of the fabrics. Bending behavior and air permeability of these fabrics were consequently studied. The results showed the mean value of fiber spinning-in-coefficient (Kf) and strength of hollow and typical ring yarns were very close, but elongation at break, unevenness and hairiness of hollow ring yarn is more than those of typical ring yarn. Results indicated that the bending rigidity and air permeability of the fabrics constructed from hollow ring weft yarn were improved due to the collapse of the fibers in the center of yarn and better flattening.
https://www.ije.ir/article_71787_778affc1cd0c26936f762b261f65b410.pdf
2009-08-01
197
204
Hollow Ring Yarn
Spinning
In
Coefficient
Tracer Fiber Technique
Fiber Collapse
bending rigidity
air permeability
A. A.
Gharehaghaji
aghaji@cc.iut.ac.ir
1
Textile Engineering, Isfahan University of Technology
AUTHOR
Abdolrasool
Moghassem
armogh@yahoo.com
2
Faculty of Engineering, Islamic Azad University Qaemshahr Branch
AUTHOR
ORIGINAL_ARTICLE
Moisture Diffusion Properties of Fabric Composite (Glass Fiber/Epoxy Resin)
In this study, the effect of hygrothermal conditioning on the moisture diffusion properties of the fabric composite (glass fiber/epoxy resin) was investigated. The water uptake of the specimens conditioned in humid environment at different relative humidities (0, 60 and 96 % r.h) at constant temperature (60°C) was evaluated by weight gain measurements. The moisture diffusion properties of the fabric composite (glass fiber/epoxy resin) were determined using standard weight gain method. The weight gain experiments were performed to determine the equilibrium moisture content Mm of the fabric composite as a function of relative humidity (r.h). The measured weight gain is then fit to the solution to the diffusion equation (Fick’s law) to determine the diffusivity D. The comparison carried out between the values obtained of the characteristic parameters (D and Mm) of the kinetics of water absorption by the hygrothermal test of conditioning carried out into the laboratory and those given by Loos and Springer confirms the following principal remarks clearly: the diffusion coefficient D and the maximum weight gain Mm depend not only on the nature of material but also of the environmental conditions (hygrothermal conditioning). The maximum concentration of water (matrix+interface) obtained from calculations based on measured values, where a homogeneous diffusion phenomenon is assumed inside the material (Df=0), shows clearly that the presence of fibers in a polymeric matrix reduces the water up-take of the matrix by about 4 times.
https://www.ije.ir/article_71789_1d4591c086fcaa5d0d187627a84e1058.pdf
2009-08-01
205
210
Moisture Diffusion Properties
Hygrothermal Conditioning
Fabric Composite Materials
A.
Naceri
abdelghani_naceri@yahoo.fr
1
Civil Engineering, M'sila University
AUTHOR