University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Computer Aided Training Needs Analysis And Performance Improvement Measurement(Ca- Tnapim) System
1
17
EN
Hussein
Salem Ketan
Layla
Lateef Alwan
10.30684/etj.27.1.1
The purpose of training is to facilitate learning skills and knowledge required.<br />Success or failure of any education and training will depend to a very large extent on the<br />accuracy and effectiveness of the needs analysis. The outcome of training is acceptable<br />performance on these tasks. In this research an algorithm is established in order to build a<br />computer aided training needs analysis system based on 360 º-feedbacks approach for<br />performance appraisals. This system is called CA- 360º TNAPIM. Mathematical model<br />is designed in this work in order to analyze training needs which is used to calculate the<br />performance gap of each trainee and of each management level in the organizational<br />hierarchy, The performance gap at each performance objective of each employee, all<br />performance objectives of each employee, each performance objective of all employees<br />and Performance gap of factory or an organization The system has been tested in (Sٍtate<br />Company for Electrical Industries), in (Motors of Air-Cooler Factory), and showed<br />Performance gap of factory before training was 26.77%, Performance level was<br />73.23%, after training was 19.87%, 80.13% and Performance improvement level was<br />25.70% .
training needs analysis,performance appraisal techniques,performance gap,degree feedback approach,hierarchy management levels
https://etj.uotechnology.edu.iq/article_28494.html
https://etj.uotechnology.edu.iq/article_28494_3a6125bcc1abff497c2e8cd80d350e4a.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Through manufacturing and assembly processes, materials and parts transfers inter series of workstations, where the product starts
1
9
EN
Sawsan
Sabih
Al-zubedi
Zainab
Alawi
Ibrahim
zaynab.2010@yahoo.com
10.30684/etj.27.1.16
from raw materials and semi products<br />pass through many tasks, these tasks differ in numbers and complexity with the product<br />differece, design specifications, and also the production system type. Tasks time<br />differential cause work in process inventory problem or idle time problem in some<br />workstations of the line. These problems affect efficiency of the line and increase the<br />total production cost. In this research, computer aided visual monitoring system designs<br />and builds for monitoring the flow of materials and determine location and quantity of<br />work in process inventory in the production line to minimize this problems by rearrange<br />workstations of the line and connecting the critical stations that materials blocked in it<br />with extra stations in parallel to minimize the work in process inventory among<br />workstations of the line possiblely to minimum level to increase the flow of materials<br />and then to the increases efficiency of the line .The suggested system applied at the state<br />company for electrical industries on the stator production line where the system uses for<br />monitoring & studying flow of materials between its workstations. The researcher<br />depends on company data&his grouping data. Monitoring &studying the current<br />workstations arrangement shows low efficiency (50.96%) and low daily production rate<br />(270 unite/day), so arrange workstations of the line by suggested arrangement, can<br />increase the line efficiency to (77.96%)and also can increase daily production rate to<br />(540unite/day) by arrange the line workstations by suggested arrange
Work in process inventory,idle time
https://etj.uotechnology.edu.iq/article_28513.html
https://etj.uotechnology.edu.iq/article_28513_ee919ada07812c6a06c34cfb329d47e6.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
The Mesopotamian marshlands
10
20
EN
Abdul-Razaq
Tarish
Zaboon
Salah
Abed-Alhameed.
Salih
Ail
Kareem.
Shayesh
10.30684/etj.27.1.17
The Mesopotamian marshlands, the largest wetland in the Middle East and one of<br />the most outstanding in the world have been lost mainly as a result of drainage and<br />damming. The cause of the decline is mainly as a result of damming upstream as well as<br />drainage schemes since the 1970s. The Tigris and the Euphrates are amongst the most<br />intensively dammed rivers in the world. In the past 40 years, the two rivers have been<br />fragmented by the construction of more than 30 large dams, whose storage capacity is<br />several times greater than the volume of both rivers. Satellite images provide hard<br />evidence that the once extensive marshlands have dried-up and regressed into desert,<br />with vast stretches salt encrusted. Recent satellite imagery shows only limited areas of<br />the marshlands have been reclaimed. The objected of this study was to classify a land<br />cover methodology through digital analysis of historical and new satellite data. Two<br />satellite images, Landsat (TM) and MODIS of AL-Kurmashia Marsh south of Iraq<br />acquired in 2003 (before reflooded) and 2005 (after reflooded).
https://etj.uotechnology.edu.iq/article_28514.html
https://etj.uotechnology.edu.iq/article_28514_e78a2b46fa949e67b29bfc806a90d7f3.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Modeling Time to Corrosion Initiation in High-Performance Ferrocement Exposed to Chlorides Environments
18
31
EN
S.
A. Salih
Maan
S. Hassan
J.
Forth
10.30684/etj.27.1.2
The applications of a mineral admixture, or a zinc coating to steel surface, or a<br />combination of both are methods used for the corrosion prevention of ferrocement<br />element in this study. Results of a study to evaluate many corrosion protection systems<br />with metakaolin and/or galvanized steel mesh are presented in six U-shaped specimens.<br />Specimens were built to simulate exposure conditions typical for marine environment.<br />Laboratory data collected along duration of 40 weeks of exposure were used in<br />modeling the cover depth as a function of time to corrosion initiation of the investigated<br />corrosion prevention methods. Methods used to assess the condition of specimens<br />included chloride concentration measurements, and corrosion rates. Model predictions<br />show that the ferrocement specimen of high-performance mortar with metakaolin<br />provides much better level of protection against moisture and chlorides than the<br />conventional specimen, by delay rate of chloride ingress. Application of a galvanized<br />steel mesh causes an elevation of the chloride threshold resulting in an additional<br />increase in the predicted time to corrosion initiation.
Modeling,ferrocement,corrosion,Service life,Durability,Metakaolin,Galvanized steel
https://etj.uotechnology.edu.iq/article_28495.html
https://etj.uotechnology.edu.iq/article_28495_2e1066d9a7bebb47da3f790f805aaeba.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Towerd Method to Find The Elevations of Points to Creat Digital Elevations Model (DEM) Using Global Positioning System(GPS)
21
25
EN
Safaa
Jassim.
Mohammed
Salah
Yousif.
Abood
10.30684/etj.27.1.18
In this present research mathematical model is built , this model has the<br />ability of using global positioning system (G.P.S) to compute the elevations with<br />high accuracy to use in mapping contour lines with contour interval 1m applied in<br />fabricating digital elevation model (DEM). Certain spot height are chosen by<br />means of universal standard, the measurements are mathematically analyzed using<br />general equations in geodesy to obtain acceptable accuracy to all engineering<br />works .
https://etj.uotechnology.edu.iq/article_28515.html
https://etj.uotechnology.edu.iq/article_28515_e29cd4e89386f56c33ef36659e7020d5.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
this paper
26
43
EN
Alaa
Hassan.
Ali
10.30684/etj.27.1.19
This paper concentrated on the study of stresses effected on governing blade<br />during steam turbine working which are represented by the pressure of 12 atm caused<br />by nuzzled steam and with rotating speed about 3000 rpm and temperature of 538 c.ْ<br />The aim of this research is to know the design parameters, all forces simulated by<br />analysis package (Ansys 5.4) to know the magnitudes of different stresses and strains<br />and their distribution on which the blade design depend on.
https://etj.uotechnology.edu.iq/article_28516.html
https://etj.uotechnology.edu.iq/article_28516_c18326434497e34bf6d8ff483a7f367b.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Using Citric Acid As An Admixture and It's Influence on Some Properties of Concrete
32
41
EN
Wasan
I. Khalil
10.30684/etj.27.1.3
The objective of this investigation is to find the effectiveness of the citric acid as<br />retarding admixture. The experimental results indicate that the optimum dosage of citric<br />acid is 0.02% by weight of cement. This dosage causes a delay in initial and final setting<br />time of 1:42 and 3:18 hour: minute, respectively; and a reduction in water-cement ratio<br />of 13% relative to reference concrete mix. So, citric acid can be classified according to<br />ASTM-C494 as water-reducing and retarding chemical admixture type D.<br />The investigation also extends to evaluate the effect of using citric acid on<br />properties of concrete such as, compressive strength, splitting tensile strength, modulus<br />of rupture and dynamic modulus of elasticity at normal conditions and after exposure to<br />salt solutions. Generally the results indicate that using citric acid in concrete enhance it's<br />properties at normal conditions, the percentage increase in compressive strength,<br />splitting tensile strength, modulus of rupture and dynamic modulus of elasticity at age<br />180 days was about 56%, 13%, 24% and 8% respectively relative to reference concrete.<br />Also it was observed that concrete containing citric acid has good performance after 180<br />days exposure to salt solution in comparison with reference concrete.
Citric acid,Admixture,initial and final setting time,compressive strength,splitting tensile strength,modulus of rupture
https://etj.uotechnology.edu.iq/article_28496.html
https://etj.uotechnology.edu.iq/article_28496_8283b642de5ff999ec49a7414153424b.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Near IR Laser Beam Analyzing System
42
52
EN
Mohamed
S.Ahmed
Muna
S. Yousif
10.30684/etj.27.1.4
A simple and reliable laser beam analyzing system has been constructed and utilized for<br />analyzing NIR laser beams. The system uses a CCD camera of 488×380 pixels (12 m<br />pixel size) CCD chip, which is interfaced with a PC computer. Computer programs,<br />utilizing facilities provided by MATLAB software, have been developed for analyzing<br />laser beams and display them in 2D and 3D configurations. The obtained good quality<br />laser beam images together with the efficient developed software have made the system<br />a reliable profiler.
Laser profiler,Laser analyzer
https://etj.uotechnology.edu.iq/article_28497.html
https://etj.uotechnology.edu.iq/article_28497_c5fab279bd6bbff47484885908e66c1d.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Studying The Effect of Some Used Collectors in Iron Ore Concentration by Froth Flotation
44
56
EN
Faiza
Ali.
Samir
Sawsan
Mohammed
Noori
10.30684/etj.27.1.20
This study explained that the used collector type and the Flotation<br />Procedure have apparent effect on concentration procedure, the results explained<br />that the used of these collectors lead to occuring of reversed anionic silica flotation<br />and on using the formic acid it has been noted that the Iron grade increases when<br />the collector weight reaches to 64% It adding 0.5 gm of the acid. and when acetic<br />acid was used there is an increasing in Iron grade with increasing of acetic percent<br />which reaches to 76% inadding 0.3 gm of the acid but on the pH=11 with(0.3) gm<br />of the same acid (acetic acid) the Iron grade increases to 89% and in using streaic<br />acid it has been noted that the Iron grade that goted becomes constant which is<br />about 65% so from these results it had been noted that the acetic acid gives the best<br />results where it had reached to 89% of Iron grade on adding 0.3 gm of this acid on<br />pH=11
Iron Ore,Concentration by Froth Flotation
https://etj.uotechnology.edu.iq/article_28517.html
https://etj.uotechnology.edu.iq/article_28517_dde1648b5a9cd45f42257118dcb71a21.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Behavior of Composite Steel-Concrete Beam Subjected To Negative Bending
53
71
EN
Ikbal
N. Korkess
Anas
H. Yousifany
Qais
Abdul-Majeed
Husain
M. Husain
10.30684/etj.27.1.5
This work deals with the behavior of structural continuous composite steelconcrete<br />beams, which are widely used in building and bridge constructions. Therefore<br />the structural behavior of composite beams under negative moment is a significant<br />subject. However experimental tests in this field are very rare and information about the<br />efficiency of shear connection when the slab is under tension are really few.<br />In the present research, available experimental tests on composite steel-concrete<br />beams under negative bending are theoretically analyzed using the finite element<br />software ANSYS. ANSYS computer program is a large-scale multipurpose finite<br />element program which may be used for solving several cases of engineering analyses.<br />The proposed three dimensional model is able to simulate the overall flexural<br />behavior of composite beams. This covers; load-deflection behavior, longitudinal slip at<br />the steel-concrete interface, and distribution of shear studs. The reliability of the model<br />is demonstrated by comparison with available experiment and alternative numerical<br />analysis which shows 9-10% difference.
ANSYS,Composite beams,Finite element method,Negative moments,partial interaction,slip,uplift
https://etj.uotechnology.edu.iq/article_28498.html
https://etj.uotechnology.edu.iq/article_28498_a29051e3c2e0afc94cf26e694c37e421.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Utilization of Variable Message Signs to Reduce the Queue Delay Values at Off-Street Parking Facilities
72
80
EN
Ali
M. K. Al-Ubaidy
10.30684/etj.27.1.6
Generally, Advanced Parking Management Systems (APMS) use Variable<br />Message Signs (VMS) to provide drivers with updated information on the number of<br />open spaces at selected off-street parking facility to minimize or avoid parking search<br />traffic within a full car park facility, and reduce the delay times at the entrance and exit<br />gates of a parking facility. The simulation model STARSIM-VMS is developed, in the<br />present study, to simulate the operation of a designed parking garage with the<br />implementation of the VMS technology. The simulation results show that the delay<br />values is smallest than that predicted without using the VMS technique, especially at<br />the high proportions of vehicles waiting to park. These results reflect the importance of<br />using the VMS in the transportation systems.
Parking,Variable Message Sign,Delay times
https://etj.uotechnology.edu.iq/article_28499.html
https://etj.uotechnology.edu.iq/article_28499_8de588c2049a61b18cd0d0bad9bd96e4.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Estimation of Baghdad Municipal Solid Waste Generation Rate
81
95
EN
Adnan
A. Alsamawi
Abdul
Razzak T. Zboon
Aumar
Alnakeeb
10.30684/etj.27.1.7
Generally In this paper, Baghdad Municipal Solid Waste (MSW) Generate for<br />five years period (from year 2006 to year 2010). This Period are estimated as a minimum<br />duration of landfill site operation time. Geographic Information System (GIS) technique<br />are used to prepare digital map of Baghdad city to determine all of Baghdad ten districts<br />areas and its geographic distribution. Population size forecasting are interpolated to find<br />urban population size of each district and its population density. Depending on economic<br />studies of population wealth variation of Gross Domestic Product (GDP) and the<br />adopted percentage of the chronically poor population in Baghdad which could<br />reach 40% in some districts, the individual waste generation rates of each districts<br />are assumed to ranged between 0.3 and 0.8 kg/capita/day. A value of 0.63<br />kg/capita/day is concluded for the year 2006 and increase it at a net rate (growth<br />rate less waste reduction rate) of the expected GDP increase of 4% per year to<br />reach 0.74 kg/capita/day in year 2010. Comparison between the obtained estimation<br />with other studies for other countries, puts Iraq in class of middle income countries.
Municipal Solid Waste,landfill,Generation Rate,population,GIS
https://etj.uotechnology.edu.iq/article_28500.html
https://etj.uotechnology.edu.iq/article_28500_77d13d94dae11976d3da7a8b96ed62d1.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Flexural Rigidity of Slender RC Columns
96
115
EN
Sabeh
Z. Al-Sarraf
Ihsan
A. S. Al-Shaarbaf
Bassman
R. Al-Bakri
Kaiss
F. Sarsam
10.30684/etj.27.1.8
166320 hypothetical reinforced concrete (RC) columns, each with a different<br />combination of variables, were used to investigate the major variables that affect the<br />flexural rigidity (EI) of slender RC columns. Using linear regression analysis, new EI<br />expression was statistically developed for 131 slender RC columns. These columns were<br />experimentally tested and available in the literature. This proposed EI expression were<br />introduced into the ACI 318M-05 Code column design procedure to make comparisons<br />between 150 column experimental data with theoretical estimates of the nominal<br />strength using theoretical other methods. These estimates include, in addition to the proposed<br />EI expression, other calculations from the literature.
building codes,columns,flexural strength,reinforced concrete,rigidity,Slenderness Ratio,statistical,structural design
https://etj.uotechnology.edu.iq/article_28501.html
https://etj.uotechnology.edu.iq/article_28501_6c0ba50e4f8870e4805331c933389a00.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Study The Effect Of The (Al) And (Al2O3) Particles Reinforcing On The Wear Volume Loss Characteristics Of Epoxy
116
126
EN
Jamal
Jalal Dawood
Bassam
Ali Ahmed
10.30684/etj.27.1.9
This study investigated experimentally the wear volume loss of the epoxy reinforced<br />by (Al) and (Al2O3) particles of grain size ( £ 30 mm) with different four volume<br />fractions of the reinforcements which are (3 %, 6 %, 9 %, and 12 % Vol.). Pin-on-Disc<br />wear test were conducted to exam the wear volume loss behavior of the composite<br />specimens. The wear test results indicated that the wear volume loss of the specimen<br />increases with the increase of the applied load and sliding time, while it decreases with<br />the increase of the volume fraction of the reinforcing material. Also the results show that<br />the average volume loss of the epoxy reinforced by (Al) was higher than reinforced by<br />(Al2O3) by the value was (45 % ) at volume fraction (= 6 %), sliding speed (Vs =2<br />m/sec.) and sliding time ( T =300 sec.)
https://etj.uotechnology.edu.iq/article_28504.html
https://etj.uotechnology.edu.iq/article_28504_76fdb372518522e7ca3450e4e4440a02.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Time Dependent Analysis of Tunnels Using The Finite Element Method
127
151
EN
Mohammed
Y. Fattah
Kais
T. Shlash
Nahla
M. Salim
10.30684/etj.27.1.10
The analyses of tunnels in clay were carried out taking into consideration two<br />great important and effective categories, the time independent and time dependent. Time<br />independent behaviours are used to represent the excavation stage while time dependent<br />analyses are used to represent the behaviour of the unlined tunnel after a long time.<br />The finite element analyses were carried out using the linear elastic model for the<br />concrete liner while elasto-plastic and modified Cam clay model for the soil. The<br />excavation has been used together with transient effects through a fully coupled Biot<br />formulation. All these models and the excavation technique together with Biot<br />consolidation are implemented into finite element computer program named "Modf-<br />CRISP" developed for the purpose of these analyses.<br />In this paper, the basic problem represents the proposed "Baghdad metro line"<br />which consists of two routes of (32 km) long and 36 stations is analyzed. The tunnel is<br />circular in cross section with a (5.9) m outer diameter and (0.45) m of concrete lining<br />thickness. Eight-node isoparametric elements are used to model the soil and concrete<br />lining. Four-node element is used for pore water pressure.<br />Two kinds of analyses are carried out:<br />a- Using elastic-plastic constitutive model for all soil layers.<br />b- Using modified Cam clay model (MCC) for the first soil layer (upper layer) and<br />elastic-plastic Mohr Coulomb for the other two layers.<br />The movements of the soil around the tunnel at the end of excavation at typical<br />points (crown, spring line and the invert) are calculated. The results indicate that there is<br />an inward movement at the crown and this movement is restricted to four and a half<br />tunnel diameters. A limited movement can be noticed at spring line which reaches<br />0.05% of tunnel diameter, while there is a heave at the region below the invert, which<br />reaches its maximum value of about 0.14% of the diameter and is also restricted to a<br />region extending to (1.5) diameters.<br />It was found that the maximum consolidation settlement above the tunnel is about<br />three times that at the end of excavation. The settlement trough extends only to (5)<br />tunnel diameters using consolidation analysis while it is extended to (12) tunnel<br />diameters using undrained analysis.
https://etj.uotechnology.edu.iq/article_28505.html
https://etj.uotechnology.edu.iq/article_28505_72081d1ff20b47ea8c0f582b02d76aee.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Ultrathin Te Films on Si(111): Schottky Barrier Formation and Photovoltaic Applications
152
158
EN
Khaleel
I. Hassoon
10.30684/etj.27.1.11
In this work, ultrathin trillium films were evaporated on chemically etched<br />silicon substrate. Schottky barrier heights (SBHs) of Te contacting to n-Si were<br />determined by analyzing dark current-Voltage (I-V) curves and illuminated short<br />circuit current-open circuit voltage (Isc-Voc) curves. To eliminate the effect of<br />series resistance we used Norde method to extract effective SBHs. Experimental<br />results showed good reasonable agreement of the barrier height values. There is<br />more than one mechanism to transport the current through the barrier. The<br />possibility of using Te-nSi as a photovoltaic device is presented in this work.
https://etj.uotechnology.edu.iq/article_28507.html
https://etj.uotechnology.edu.iq/article_28507_c6e603eb7ba3cfc316ea16d8dfb127ec.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Modeling of A Miso Control System For A Turboshaft Engine
159
171
EN
Arkan
k.AL-Taie
Usama
S.Salah
10.30684/etj.27.1.12
The general configuration of a turboshaft gas turbine control systems model is<br />presented. The control systems included the relationships between the engine and its<br />limitations such as a compressor surge line limit, exhaust gases temperature, the speed<br />of the engines spools. The control system is of Multi Input Single Output (MISO) type,<br />where the inputs to the controller are the limitation signals and the demand whither the<br />only single output is the fuel valve new setting. The main parameter that the system<br />controls by is that the fuel mass flow rate and the device which is doing this job is the<br />fuel controller. The control system changes the fuel flow according to the engine<br />demands by changing the fuel valve angle (θ) .<br />The time responses of each effective parameter was predicted for a different fuel<br />valve angle and introduce the most effective specifications of the time response of the<br />system (delay time, rise time, settling time and maximum overshoot). The behavior of<br />the maximum overshoot value (if founded) is increasing with the fuel valve increasing.<br />The value of delay, rising, and settling times decreases with the fuel valve angle<br />increases. The present results show a good agreement with the previous works.
https://etj.uotechnology.edu.iq/article_28509.html
https://etj.uotechnology.edu.iq/article_28509_d9f24efb924895e1486e9d1e4e1a19a3.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Study Diffusion of Water to Carbon Fiber /Epoxy Composite
172
181
EN
Adnan
A. Abdul Razak
10.30684/etj.27.1.13
In present work moisture diffusion properties of the woven fabric carbon/epoxy<br />laminates were determined using weight gain, experiments over a temperature range of<br />30 0C to 60 0C. The laminate–shaped fiber reinforced composites were manufactured by<br />using epoxy resin (Epon 828) cured with TETA (tri ethylene tetra amine) reinforced with<br />carbon fiber. The prepared Composite samples were immersed in water for several<br />weeks and moisture content was measured. The diffusivity of the composite was found<br />to obey the Arrhenius relation over the entire range of temperature. Analytical solution to<br />Fick’s law is done by build up computer program in Matlab. Good agreement between<br />experiment data and analytical solution of Fick’s Law.
composite,diffusion,laminate,Activation Energy
https://etj.uotechnology.edu.iq/article_28510.html
https://etj.uotechnology.edu.iq/article_28510_9715ac7e720b9fd561ba920dd977dd08.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Estimation Of Average Suspended Sediment Concentration In A Flow Depth By One Sample
182
202
EN
Numa
H. Imara
Hind
Y. A. Jalil
10.30684/etj.27.1.14
In this research, an attempt has been made to have full understanding about the<br />nature of the sediment in the flow. Due to the difficulties during flood periods, the<br />attention was focused on the shortcut methods to measure the average sediment<br />concentration in the water column. These methods use limited number of water<br />samples. Two groups of data have been utilized. The first group covers the field work<br />in Tigris River at Sarai site and middle Euphrates canals. The second group is outside<br />Iraq which covers Missouri River in Montana. The data of the first group has been<br />used for analysis of Imara’s semi-empirical equation for the measurement of the<br />average concentration in the water column. In this equation, an empirical constant,<br />(a) , was given a value of (10) in estimating the sediment load in the tributaries of<br />Adhaim River. A uniformity index was suggested, to analysis the vertical distribution<br />of different kinds of sediment, and then uniformity index for different kinds of<br />sediment was calculated for Missouri river in the second group of data. The value of<br />the empirical constant, (a) varied between (7.2) and (11.65) with an average value of<br />(9.4) for group one data compared with the value of (10) used for the tributaries of<br />Adhaim River. This value was accepted with a significance level (α = 0.05). The<br />uniformity index gave a value close to (1.0) for clay and silt, and a value between (1.5)<br />and (2.5) for sand depending on the sand’s grain size.
https://etj.uotechnology.edu.iq/article_28511.html
https://etj.uotechnology.edu.iq/article_28511_8d4bf86c3ec090526732fcaa805fe98d.pdf
University of Technology-Iraq
Engineering and Technology Journal
1681-6900
2412-0758
27
1
2009
01
01
Studying of The Impact Strength of Rubber- Toughened Thermosets
203
215
EN
Awham
Mohammed Hamid
Sabah
S. Abd Al Noor
Balkees
M. Dhyaa
10.30684/etj.27.1.15
In this investigation, the development of composite materials was achieved<br />in two steps. The first, by the hybridization of the resin matrix with different<br />elastomers to prepare binary polymer blends, these blends have been synthesized<br />by mixing either of (Nitrile Rubber(NBR), Styrene Butadiene Rubber(SBR) and<br />Butadiene Rubber(BR)) with the Epoxy resin(EP) and Unsaturated polyester<br />resin(UP). The second step is reinforcement of the polymer blends with 30% of<br />two types of fibers. The first, is by using E-glass fibers alone while the second by<br />utilizing a hybrid of E-glass fibers with Kevlar fibers (type-49). Different weight<br />percentages (5, 10, 15,…., 50)% of those elastomers were mixed with each of EP<br />and UP. The optimum mixing ratios (OMR) of those blends have been selected<br />depending on achieving acceptable macro miscibility, best adhesion between two<br />phases and highest impact strength (I.S) of the resulting blends. The values of<br />(I.S) increased gradually with increasing of rubber content until its maximum<br />value (OMR), and then it goes down as the percentage of the elastomer<br />increases. Five blends with (OMR) were prepared : EP/NBR(80/20)% ,<br />EP/BR(70/30)% , UP/NBR (90/10)%, UP/SBR (90/10)% , UP/BR (90/10)%,<br />while a phase separation of SBR rubber from EP resin has taken place at all<br />ratios; then, these blends were reinforced with single and hybrid fibers. Impact<br />test was carried out at different environmental conditions to have full description<br />about the mechanical behavior of those blends and their composites under effect<br />of the impact stress.
https://etj.uotechnology.edu.iq/article_28512.html
https://etj.uotechnology.edu.iq/article_28512_f714f0d6b6d41f42ad227c45c4b1fefb.pdf