Ammar Yaser Ali; Maha Ghazi Zghair
Volume 8, Issue 2 , June 2015, Pages 99-119
Abstract
This study presents experimental and theoretical investigation of the overall shear behavior of reinforced concrete deep beams made from hybrid concrete strength : Normal strength concrete (NSC) in tension zone and high strength concrete (HSC) in compression zone. The experimental work included testing ...
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This study presents experimental and theoretical investigation of the overall shear behavior of reinforced concrete deep beams made from hybrid concrete strength : Normal strength concrete (NSC) in tension zone and high strength concrete (HSC) in compression zone. The experimental work included testing of nine models of hybrid reinforced concrete deep beams under the effect of two point loads. One of the beams was tested as pilot and the other eight beams were divided into two groups namely group (A) and group (B) to study the effects of the following parameters: (HSC) the layer thickness, the effect of presence of web reinforcement and method of casting (i.e. monolithically or at different times), on the ultimate shear strength, the cracking load, the cracking pattern, the deflection, the ductility and failure modes.
The experimental test results obtained from the adopted hybridization technique of (HSC) and (NSC) have shown that for beams made from (HSC) (about 45MPa) with a layer in compression zone of thickness (25 - 50)% of total beam depth, the ultimate shear strength was increased about (11.2 - 19.5)% for beams without web reinforcement and (16.75 - 22.25)% for beams with minimum web reinforcement. It has also shown that, the first cracking load was increased about (32.8 - 48)% and (43.4 - 57.9)% for beams without and with web reinforcement, respectively.
The hybrid concrete beams that cast monolithically, have exhibited an increase in ductility about (13.3- 22.6) % and (17.3 - 26.3) % for specimens without and with web reinforcement, respectively. While, the hybrid concrete beams with construction joint and epoxy resin layer of thickness about (1mm), have exhibited larger increasing in ductility about (28.7%) and (30.2%) for specimens without and with web reinforcement, respectively.
On the other hand, a non-linear three dimensional finite elements simulation using ANSYS computer program was adopted to trace the load-deflection response, cracking pattern and ultimate shear strength of the tested reinforced hybrid concrete beams with or without construction joint. Afterward, a parametric study has been conducted to investigate the effects of many important variables (compression strength for (HSC) layer, thickness of (HSC) layer, shear span to effective depth ratio ( ), thickness of resin bond layer).
Comparison between the analytical and experimental results has shown a reasonable agreement of the load-deflection response, where, the average of the maximum difference in first cracking a
jubory; Kanaan Mohammad Musa AL
Volume 8, Issue 2 , June 2015, Pages 120-127
Abstract
There are Several technological revolutions underway which apply to much of biology like Structural imaging, Functional imaging, Patterned photo-stimulation and Super-resolution techniques which is can use for recording activity from many parts of single neuron in vivo or many neurons in vivo. 2-Photon ...
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There are Several technological revolutions underway which apply to much of biology like Structural imaging, Functional imaging, Patterned photo-stimulation and Super-resolution techniques which is can use for recording activity from many parts of single neuron in vivo or many neurons in vivo. 2-Photon Microscopy and Linked Optical Methods for Imaging Neurons can give Imaging deep within non-transparent living tissue such as brain….Two-photon fluorescence microscopy allows three-dimensional imaging of biological specimens in vivo. Compared with confocal microscopy, it offers the advantages of deeper tissue diffusion and less photo damage but has the disadvantage of slightly lower resolution. Two-photon microscopy is expected to have an impact in areas such as physiology, neurobiology, embryology and
tissue engineering, for which imaging of extremely scattering tissue is required. I am trying strive to meet the challenge offered by the chance to ask questions about the workings of as cell that we never thought we could answer, we need to be aware that the new technologies are still evolving. The current limitations of each technique need to be measured when identical them to specific biological requests. In this review, we briefly describe the principles of super-resolution optical microscopy and focus on comparing the features of each technique that are significant for their use in learning nanosensing in the cellular microenvironment.
Ayad Dari Jaafar
Volume 8, Issue 2 , June 2015, Pages 128-136
Abstract
The present investigation is concerned to study the prepared of nano composite catalyst of titanium dioxide and carbon nanotube (TiO2/CNT) based on photo-catalysts process. The synthesized composite catalyst was characterized by Brunauer, Emmett and Teller (BET), Scanning Electron Microscopy (SEM), X-ray ...
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The present investigation is concerned to study the prepared of nano composite catalyst of titanium dioxide and carbon nanotube (TiO2/CNT) based on photo-catalysts process. The synthesized composite catalyst was characterized by Brunauer, Emmett and Teller (BET), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), XRF and Raman Spectroscopy. Moreover, the nano composite catalyst was used as a dye to degradation of contaminated water that containing organic pollutants. The photo-catalytic degradation process was carried out at different operational parameters, (Initial concentration of hydrogen peroxide H2O2 of the medium, mixing speed, and flow rate for methylene blue (MB, C16H18N3SCl.3H2O) dye). The nano titanium dioxide / carbon nanotubes (TiO2/CNT) composite showed greater photo-degradation activity under solar and ultraviolet (UV) lamp.
Shaimaa Hilal Kamel
Volume 8, Issue 2 , June 2015, Pages 137-146
Abstract
Reinforcement of unsaturated polyester by particulates plays is an important role in the improvement of the mechanical properties of high performance materials. Hence, the mechanical behavior of recycled (grapes and dates) particulate polyester composites was studied in order to develop an engineering ...
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Reinforcement of unsaturated polyester by particulates plays is an important role in the improvement of the mechanical properties of high performance materials. Hence, the mechanical behavior of recycled (grapes and dates) particulate polyester composites was studied in order to develop an engineering material for industrial applications. Different percentages (0, 1.5, 3.5 and 5) % of the reinforcement Particles were added to unsaturated polyester resin. Numbers of mechanical tests were included (thermal conductivity test, hardness test, Dielectric testing, tensile test, impact test). The results showed that the hardness and dielectric constant of filled unsaturated polyester increase with the increment of the percentage of grapes and dates particles, while impact resistance decreases. On the other hand the thermal conductivity increase at (1.5%) of percentages and decreases of (3.5%, 5%) of grapes particles while the value of thermal conductivity decrease by (1.5%) and increased when increasing (3.5 %, 5%) of the dates particle. The tensile strength improves of grapes reinforcing particles and increase with an increase in the particle percentage of grapes and the value of tensile strength increases with the dates particle content (1.5%). Also that the percentage of (3.5 %) represents the greatest value for the modulus of elasticity for unsaturated polyester reinforced with dates particle and the percentage of (5 %) represents the greatest value for the modulus of elasticity for unsaturated polyester reinforced with grapes particle.
Hussein H. Hamed
Volume 8, Issue 2 , June 2015, Pages 147-158
Abstract
An adsorption (PSA) unit consist of two – tubes columns pressure swing, (6cm diameter and 70cm bed length) and a dryer part (12cm diameter and 27cm) filling with activated alumina (Al2O3) have been constructed to study the separation of oxygen and nitrogen from air using commercial 5A zeolite under ...
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An adsorption (PSA) unit consist of two – tubes columns pressure swing, (6cm diameter and 70cm bed length) and a dryer part (12cm diameter and 27cm) filling with activated alumina (Al2O3) have been constructed to study the separation of oxygen and nitrogen from air using commercial 5A zeolite under the effect of adsorption pressure (1 to 6 bar), adsorption time (20s), product flow rate (1 liter/min) on the product oxygen purity. For the case of 2-column, 4-step operation, the results show that an optimum concentration product of oxygen was 76.9%purity,at the adsorption pressure 4bar, Temp 17.4oC.Nitrogen optimum production was78.8% purity, at 1 bar
Sami A.Ajeel
Volume 8, Issue 2 , June 2015, Pages 159-170
Abstract
Low carbon steels are widely used materials in industrial application due to its availability and properties. Therefore it always needs to improve its properties especially corrosion resistance. One of the most important methods for improving its corrosion resistance is anodizing process. This study ...
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Low carbon steels are widely used materials in industrial application due to its availability and properties. Therefore it always needs to improve its properties especially corrosion resistance. One of the most important methods for improving its corrosion resistance is anodizing process. This study involves anodized of low carbon steels in 1 M sodium hydroxide (alkaline) electrolyte for 30 minute, using constant current technique at a range of (20-620) mA/cm2.
Atomic force microscope (AFM) used to investigate the topography and anodic film parameters, it was found that the roughness of the anodic film is mainly depend on the anodizing current density and its increase from 0.9 (as polished) to (0.281-0.598) nm after anodizing. Coating thickness also increases with an increase in current density supply to the range of (2.5-13.3) μm. The corrosion behaviors of anodized and non-anodized of low carbon steel specimens in sea water are obtained. The corrosion current density and corrosion rate are decreased with an increase in anodic current density which increases anodic film thickness.
balasim A. Abid; Nada Mahdi Farhan; Shurooq Talib Al-Hemeri
Volume 8, Issue 2 , June 2015, Pages 171-185
Abstract
This work discusses the effect of superficial gas velocity and liquid properties (viscosity μ, surface tension σ, thermal conductivity k , density ρ , specific heat Cp ) on the heat transfer coefficient and gas holdup investigated in a bubble column. Experiments were carried out in a Plexiglass column ...
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This work discusses the effect of superficial gas velocity and liquid properties (viscosity μ, surface tension σ, thermal conductivity k , density ρ , specific heat Cp ) on the heat transfer coefficient and gas holdup investigated in a bubble column. Experiments were carried out in a Plexiglass column (0.15 m diameter and 1.5 m height). A perforated plate was used as a gas distributor, having 84 holes of 1mm diameter, and 0.37% opening area. The heat transfer coefficient was measured for the air-liquid systems in bubble column of four types of liquid (water, 60%ethanol, 35% glycerol, and 65% glycerol) covering a range of surface tension and viscosity values, while the gas phase is atmospheric air. The superficial gas velocity, UG, was varied in rang of (0.0037-0.094) m/sec. For all sets of experiments the height of liquid phase was maintained constant at 0.8 m above the gas distributor. From experimental, data it is found that the values heat transfer coefficient for aqueous glycerol solutions decrease with increasing concentration of glycerin and are lower than those for 60%ethanol and water solutions. This is attributed to the combined effects of surface tension, viscosity, specific heat, and thermal conductivity of the liquid. The overall gas holdup for all liquids increases with an increase in superficial gas velocity, the liquid property has an impact on gas holdup. An increase in liquid viscosity results in large bubbles and thus higher bubble rising velocities and lower gas holdup. A correlation based on dimensionless groups for the prediction of heat transfer coefficient is proposed and found to be in good agreement with available data.
Keywords: heat transfer coefficient; liquid properties; bubble column
Nabaa Shakir Hadi
Volume 8, Issue 2 , June 2015, Pages 186-198
Abstract
The records of influents concentration for both BOD5 and TSS of Maamera sewage treatment plant which were chosen of this study are very important parameters, They play an important part in the planing and management of the national water resources. Most of these records have periods of missing data ...
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The records of influents concentration for both BOD5 and TSS of Maamera sewage treatment plant which were chosen of this study are very important parameters, They play an important part in the planing and management of the national water resources. Most of these records have periods of missing data of the influent BOD5 and TSS. In this study a model for generating missing monthly concentrations influent BOD5 and TSS. Data are introduced. Initially univariate models using the Box-Jenkins approach were fitted to the logarithmically transformed series. Both transformed series were found to be generated by a random process using sampling theory were considered to be white noise. Ordinary regression analysis was performed. No significant correlation between influent BOD5 and TSS concentration were found.
Ahmed Toman Thahab
Volume 8, Issue 2 , June 2015, Pages 199-210
Abstract
Steganography is the capability to embed important data in a cover media without alarming the observer that data is embedded. There are many methods which are used to carry secret data, mostly are image and audio. In this paper a new video steganography concealing a secret video in a cover video taking ...
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Steganography is the capability to embed important data in a cover media without alarming the observer that data is embedded. There are many methods which are used to carry secret data, mostly are image and audio. In this paper a new video steganography concealing a secret video in a cover video taking the technique of steganography to a new stage. The secret video is encoded using Set Partitioning in Hierarchical Trees (SPIHT) using bi-orthogonal decimated wavelet transform, the data of the secret video is embedded in the decimated wavelet domain of the cover media, in the three bands that have high frequency content, by replacing the cover coefficients of the wavelet domain with the encoded secret coefficients. The process is applied on each frame of the secret and cover videos producing an imperceptible and robust stego-video. Image quality metrics are utilized to assess the performance of the algorithm. Experimental results show that the method produces a high video resolution using various standard video sequences and other statistical assessment. Proposed algorithm does not only apply on video but on still images as well, a collection of experiments are also applied on various content images and compared with previous work in terms of image metrics and statistics.
Khamail Abdul-Mahdi Mosheer
Volume 8, Issue 2 , June 2015, Pages 211-224
Abstract
In the present paper, experimental investigations were conducted to improve the properties of concrete by using conductive screws as a fibre. Screws of two different lengths were used (1/2 inch and 1 inch). These screws were made of iron coated with Zinc-Aluminium alloy (called Al-Clad), which is resistant ...
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In the present paper, experimental investigations were conducted to improve the properties of concrete by using conductive screws as a fibre. Screws of two different lengths were used (1/2 inch and 1 inch). These screws were made of iron coated with Zinc-Aluminium alloy (called Al-Clad), which is resistant to corrosion and rust. This coating gives the screw strength and flexibility. The water/cement ratio used was w/c = 0.55 and the volume fractions of the conductive screw were 0%, 0.5%, 1%, and 1.5% by volume of concrete mix. The results show that the use of the conductive screw enhanced the mechanical properties of concrete. The compressive strength increases with increasing the volume fraction of the screw with a length of 1 inch. For 1.5% fibre content, the strength was increased by 24.28%, 23.66%, and 20.91% for 7, 28, and 90 curing days respectively compared to the reference mix. The same trend was observed with the modulus of rupture results. For the same length and with the 1.5% volume fraction of fibre, the modulus of rupture increased by 19.44% and 32.26% for 7 and 28 days of curing respectively. The splitting tensile strength also increased by 27.05% and 33.17% for 7 and 28 curing days respectively for 1.0% fibre content
Dhafeer M. H. Al-Shamkhi; Wisam A. Abd Al-Wahid
Volume 8, Issue 2 , June 2015, Pages 225-241
Abstract
The heat losses by convection from the collector tube of a trough collector to the ambient are analyzed. The strategy to reduce such losses is by using a vacuum glass tube covering the collector tube. Since the maintaining of this vacuum state is difficult, beside the high cost and easily broken off ...
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The heat losses by convection from the collector tube of a trough collector to the ambient are analyzed. The strategy to reduce such losses is by using a vacuum glass tube covering the collector tube. Since the maintaining of this vacuum state is difficult, beside the high cost and easily broken off the glass tube, another strategy presented in this paper. The strategy based on reducing the overall convection heat transfer by the use of guides made of metal, which effect on the process of heat transfer. The guides put in front of the collector as a half circle with different dimensions, and each one analyzed numerically by using 4.4 COMSOL Multiphysics program. The analysis include the streamlines behavior, temperature distribution, and average Nusselt number. The minimum the Nusselt number obtained the best arrangement to use. The data show a decrement in heat transfer process due to that modification with different percentages.
Mohammed HamzaAbdulsada
Volume 8, Issue 2 , June 2015, Pages 242-258
Abstract
One dimensional analysis of heat transfer from fin is simple when only heat transfer by convection
from fin surface. However, in some cases heat transfers by combined phenomena (convection and
radiation), this makes the governing differential equation of heat transfer non-linear and the analytical
solution ...
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One dimensional analysis of heat transfer from fin is simple when only heat transfer by convection
from fin surface. However, in some cases heat transfers by combined phenomena (convection and
radiation), this makes the governing differential equation of heat transfer non-linear and the analytical
solution becomes hard to solve. This paper uses an approximate method to solve the problem with
high-quality results based on finite element technique. The method can be used for different types of
fins and for different shapes. The results show suitable agreement between semi-exact solution and
numerical solution
Kadhim Naief Al-Ta; Hana M. Alkassar; Ameera Naji Hussein
Volume 8, Issue 2 , June 2015, Pages 259-266
Abstract
In this study the samples of southern drainage water and Euphrates river water were taken from the north region of Al- Manadhra city [Najaf province-Iraq].Those samples were mixed with different ratios by adding drainage water to river water to get a new solution containing different salt. To find a ...
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In this study the samples of southern drainage water and Euphrates river water were taken from the north region of Al- Manadhra city [Najaf province-Iraq].Those samples were mixed with different ratios by adding drainage water to river water to get a new solution containing different salt. To find a standard indicator of water quality that sodium adsorption ratio (SAR) as well as examine electrical conductivity (E.C.).The results were (3.15, 3.9, 4.2, 4.8, 5, 5.2, 5.3, 5.4, 5.5, 5.6, 5.8) for (SAR), (1.58, 2.3, 3.06, 3.75, 4.35, 5.11, 5.85, 6.33, 7.2, 7.63, 8.2) for (E.C.) respectively.
Then, examine those samples of salt water where used as an irrigation water supplied to several types from of Oryza satival seeds (Al-forat class, Yassmin class, Amber Baraka class) to test germination of seeds. The results of germination of seeds with those samples of irrigation water at mixing drainage water ratios (0-100)% equal to (100-5)% for Al-forat class, (90-0)% for Yassmin and Amber Baraka class respectively
