Preferred Language
Articles
/
yoa_t4YBIXToZYAL_7Md
Numerical Analysis of Segmental Post Tensioned Concrete Beams Exposed to High Fire Temperature
...Show More Authors

The main objective of this study is to characterize the main factors which may affect the behavior of segmental prestressed concrete beams comprised of multi segments. The 3-D finite element program ABAQUS was utilized. The experimental work was conducted on twelve simply supported segmental prestressed concrete beams divided into three groups depending on the precast segments number. They all had an identical total length of 3150mm, but each had different segment numbers (9, 7, and 5 segments), in other words, different segment lengths. To simulate the genuine fire disasters, nine beams were exposed to high-temperature flame for one hour, the selected temperatures were 300°C (572°F), 500°C (932°F) and 700°C (1292°F) as recommended by ASTM–E119. Four numerical models have been utilized to represent the unburned and the burned specimens at the three elevated temperatures. Calibration and simulation of the experimental work were conducted, while comparisons were made with the experimental results. These included the prestress effect, load-deflection relation under applied load, and load at failure of the reference beam and the beams after the exposure to fire.

Crossref
View Publication Preview PDF
Quick Preview PDF
Publication Date
Wed Dec 01 2010
Journal Name
Iraqi Journal Of Physics
The effect of anode temperature on the Optical characteristic of Se films prepared by direct current planar magnetron sputtering
...Show More Authors

This work describes, selenium (Se) films were deposited on clean glass substrates by dc planar magnetron sputtering technique.The dependence of sputtering deposition rate of Se film deposited on pressure and DC power has been studied. The optimum argon pressure has range (4x10-1 -8x10-2 )mbar. The optical properties such as absorption coefficient (α) was determined using the absorbance and transmission measurement from UnicoUV-2102 PC spectrophotometer, at normal incidence of light in the wavelength range of 200-850 nm. And also we calculated optical constants(refractive index (n), dielectric constant (εi,r), and Extinction coefficient (κ) for selenium films.

View Publication Preview PDF
Publication Date
Fri Oct 01 2010
Journal Name
Iraqi Journal Of Physics
Effect of the Thickness and Annealing Temperature on the Structural Properties of Thin CdS Films Prepared by Thermal Evaporation
...Show More Authors

A thin CdS Films have been evaporated by thermal evaporation technique with different thicknesses (500, 1000, 1500 and 2000Å) and different duration times of annealing (60, 120 180 minutes) under 573 K annealing temperature, the vacuum was about 8 × 10-5 mbar and substrate temperature was 423 K. The structural properties of the films have been studied by X- ray diffraction technique (XRD). The crystal growth became stronger and more oriented as the film thickness (T) and duration time of annealing ( Ta) increases.

View Publication Preview PDF
Publication Date
Fri Jun 18 2004
Journal Name
Iraqi Journal Of Laser
Effect of Operating Temperature on Performance of Obliquely Deposited Bi, Sb and Bi-Sb Semimetal Thin Film Laser Detectors
...Show More Authors

Obliquely deposited (70o) Bi, Sb, and Bi-Sb alloy thin films have been prepared by thermal
resistive technique. Structural properties of these films were studied using XRD. Their resistance and
voltage responsivity for Nd:YAG and CO2 laser pulses have been recorded as function of operating
temperature between 10 oC and 120 oC. It was found that the maximum responsivity for these detectors
can be obtained at 75 oC. On the other hand, the dependence of responsivity on the width of detectors was
investigated.

View Publication Preview PDF
Publication Date
Wed Apr 05 2023
Journal Name
Journal Of Engineering
Analytical Solution of Transient Heat Conduction through a Hollow Spherical Thermal Insulation Material of a Temperature Dependant Thermal Conductivity
...Show More Authors

The one-dimensional, spherical coordinate, non-linear partial differential equation of transient heat conduction through a hollow spherical thermal insulation material of a thermal conductivity temperature dependent property proposed by an available empirical function is solved analytically using Kirchhoff’s transformation. It is assumed that this insulating material is initially at a uniform temperature. Then, it is suddenly subjected at its inner radius with a step change in temperature. Four thermal insulation materials were selected. An identical analytical solution was achieved when comparing the results of temperature distribution with available analytical solution for the same four case studies that assume a constant thermal con

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Tue Jan 01 2019
Journal Name
Abu Dhabi International Petroleum Exhibition & Conference
Influence of pressure and temperature on CO2-nanofluid interfacial tension: Implication for enhanced oil recovery and carbon geosequestration
...Show More Authors

Nanoparticles (NPs) based techniques have shown great promises in all fields of science and industry. Nanofluid-flooding, as a replacement for water-flooding, has been suggested as an applicable application for enhanced oil recovery (EOR). The subsequent presence of these NPs and its potential aggregations in the porous media; however, can dramatically intensify the complexity of subsequent CO2 storage projects in the depleted hydrocarbon reservoir. Typically, CO2 from major emitters is injected into the low-productivity oil reservoir for storage and incremental oil recovery, as the last EOR stage. In this work, An extensive serious of experiments have been conducted using a high-pressure temperature vessel to apply a wide range of CO2-pres

... Show More
Publication Date
Sun May 10 2020
Journal Name
Baghdad Science Journal
Temperature Impacts on the Cardiac Activity of the Snail Pomacea canaliculata from Shatt Al-Arab Region, Basrah, Iraq
...Show More Authors

The effects of temperature on an exotic aquatic snail Pomacea canaliculata  (Lamarck, 1819) collected from the Shatt Al-Arab intertidal zone were investigated. A series of laboratory experiments were conducted during the summer period of 2017. Individuals of new born snails hatched in the laboratory from adult snails were collected from Shatt Al-Arab intertidal zone, and subjected to five fixed temperatures: 15, 25, 35, 40 and 45 Cº, after short term thermal acclimation. The heartbeats (HB) were counted at each temperature level. The results showed significant  direct increase of HB from 15 Cº (19.8 HB/min) up to 25 Cº (76 HB/min) (P<0.05)  as well as from 25 Cº to 35 Cº (93 HB/min). At 40 Cº the snail HB

... Show More
View Publication Preview PDF
Scopus (1)
Scopus Clarivate Crossref
Publication Date
Sun Apr 01 2007
Journal Name
Journal Of Engineering
CURVATURE DUCTILITYOF REINFORCED CONCRETE BEAMSECTIONS STIFFENED WITH STEEL PLATES
...Show More Authors

Publication Date
Tue Oct 30 2018
Journal Name
Journal Of Engineering
Bond Stresses between Reinforcing Bar and Reactive Powder Concrete
...Show More Authors

A good performance of reinforced concrete structures is ensured by the bond between steel and concrete, which makes the materials work together, forming a part of solidarity. The behavior of the bond between the reinforcing bar and the surrounding concrete is significant to evaluate the cracking control in serviceability limit state and load capacity in the ultimate limit state. In this investigation, the bond stresses between reinforcing bar and reactive powder concrete (RPC) was considered to compare it with that of normal strength concrete (NSC). The push-out test with short embedment length is considered in this study to evaluate the bond strength, bond stress-slip relationship, and bond stress-crack width relationsh

... Show More
View Publication Preview PDF
Crossref (4)
Crossref
Publication Date
Fri Jul 21 2023
Journal Name
Journal Of Engineering
Laboratory Investigation on Roller Compaction Technique in Concrete Construction
...Show More Authors

Roller compacted concrete (RCC) is a concrete compacted by roller compaction. The concrete mixture in its unhardened state must support a roller while being compacted. The aim of this research work was to investigate the behavior and properties of roller compacted concrete when constructed in the laboratory using roller compactor manufactured in local market to simulate the field conditions. The roller compaction was conducts in three stages; each stage has different loading and number of passes of the roller. For the first stage, a load of (24) kg and (5) passes in each direction had been employed. For the second stage, a load of (104) kg and (10) passes in each direction were conducted. Finally, at the third stage, a load of (183) kg a

... Show More
View Publication Preview PDF
Crossref (2)
Crossref
Publication Date
Sat Jan 01 2022
Journal Name
Open Engineering
Producing low-cost self-consolidation concrete using sustainable material
...Show More Authors
Abstract<p>The disposal of the waste material is the main goal of this investigation by transformation to high-fineness powder and producing self-consolidation concrete (SCC) with less cost and more eco-friendly by reducing the cement weight, taking into consideration the fresh and strength properties. The reference mix design was prepared by adopting the European guide. Five waste materials (clay brick, ceramic, granite tiles, marble tiles, and thermostone blocks) were converted to high-fine particle size distribution and then used as 5, 10, and 15% weight replacements of cement. The improvement in strength properties is more significant when using clay bricks compared to other activated waste </p> ... Show More
View Publication
Scopus (11)
Crossref (10)
Scopus Clarivate Crossref