bluuebunny/crossref_metadata_2025_split huggingface dataset:
Channel Crosstalk Impact on OCDMA Performance Under Efficient Diagonal Code and Optimized Pulse Shaping
Authors: Atiya Yasseen Sadoon , Abd H. J. , Salim Noora , Din Norashidah M. , Omran Karar 
Published: January 2020

Abstract
This paper examines the four-wave mixing (FWM) effect on optical code-division multiple-access (OCDMA) performance systems in the presence of Multi-Diagonal code (MD). System performance improvement is accomplished by means of fibre length tuning and stratified different modulation shapes, which are Non-return-to-Zero (NRZ), Gaussian, and Sine wave, all examined with 500 and 1Gb/s data rate values. The tests show that the NRZ modulation offers better system performance compared with other modulations for all data rate values used. Moreover, the second channel of each user offered better system performance than the other channels used. For instance, for 1Gb/s, at the second channel, the NRZ modulation offered the best performance with a quality factor (Q –factor) of 5.1 at 100 km fibre length, whereas the first channel introduced a worse Q-factor of 3.1 at the same fibre length value.
A biomaterial for scaffold applications: Thermal properties analysis of a PSZ-TiO2/HDPE system
Authors: Kashan Jenan S. , Ali Saad M. 
Published: January 2020

AbstractHigh-density polyethylene (HDPE) matrices reinforced with titanium dioxide (TiO2) biocomposites are seen as promising biomaterials due to their superior properties. In this work, an attempt was made to study the effects of six biocomposites hybrid Titanium dioxide (TiO2) and yttria-stabilized zirconia (Y-PSZ) samples reinforced with high-density polyethylene (HDPE) matrices, split into two groups, in terms of withstanding the daily activity loads imposed by human bone grafting and repairs. The fabricated composites were investigated using the hot-pressing technique at different compression pressures and compounding temperature. To achieve characterization, thermal analysis of the process using differential scanning calorimetry (DSC) techniques was undertaken. To improve and verify the results, Design Expert 11.0 software and a response surface methodology (RSM) technique were used. For both nanofabricated types, the results showed that an increase in TiO2ceramic filler from 1% to 10 %, caused percentage crystallization to increase by 14.58%. The heat of system fusion for the second fabricated system also decreased by 11%. These results show that this addition reduced the heat of system fusion by 109% compared with previous studies. The glass transition (onset) and end (melting) temperature also increased with increases in the applied compression pressure and hot-pressing temperature when a small value, 1%, of TiO2ceramic nanoparticle fillers in the HDPE matrix. The temperature values were increased when using higher compression pressure of between 60 and 90 MPa, and the onset temperature reached a maximum value of 127 °C. This increase in onset temperature continued when using higher values of TiO2Nanoceramic filler and the onset temperature reached its maximum value with 10% TiO2and 2% PSZ Nanoceramic fillers added to the fabricated nanomaterial system. The differential scanning calorimetry (DSC) scanned curves and the 3D atomic force microscopy (AFM) microstructure and granularity distribution images for both fabricated nanocomposite systems clearly showed that the interconnections between the filler’s ceramic nanoparticles within the polymeric matrix offer high surface roughness values due to the excellent nanofiller particle distribution within the polymeric matrix.
Investigation of Chitosan Film Degradation in Tissue Engineering Applications
Authors: Kadhim Ishraq A , Abdul Ameer Zuhair J , Alzubaidi Aseel B 
Published: January 2020

Abstract
In this paper, the biological and physical properties of chitosan, a potential polysaccharide resource, were investigated. The proposed film was synthesised by mixing chitosan (CS) solution and polyvinyl alcohol (PVA) using solvent casting. The modified chitosan/PVA films were then subjected to analysis by Fourier transform infrared spectroscopy (FTIR), in which intermolecular hydrogen bonding between the molecules of CS and PVA was clearly demonstrated. The swelling degree of chitosan along with the contact angle were also examined. After the addition of genipin, which increased chitosan concentration the swelling degree, degradation rate, and contact angle was decreased. The results confirm that the properties of chitosan are such that they can be employed for tissue engineering applications.
Effect of Mud Rheology on Cuttings’ Transport in Drilling Operations
Authors: Khalil Abdulk. A. , Adnan M. S. 
Published: January 2020

AbstractSettling of solid particles in drilling fluids represents a major problem, necessitating effective removal of drilled cuttings to the surface of the well to maintain safe and profitable drilling operations. Experiments were conducted using two group of drilling fluids, Newtonian (water, gas-oil, kerosene, and ethyl-glycol) and Non-Newtonian (Carboxyl Methyl cellulose (CMC)) in four different concentrations. Four cutting sizes were used, with diameters 0.212, 0.445, 0.672, and 0.853 cm, taken from the Garraf area of the Nasirya oil fields. The test results showed lower Reynolds numbers within the laminar flow region compared with the Turbulent flow region. The drag coefficients decreased with increasing particle Reynolds number, and small particle sizes gave higher drag coefficients and lower Reynolds numbers, while large particles gave lower drag coefficients and higher Reynolds numbers in both Newtonian and Non-Newtonian fluids. The results indicate that an increase in CMC concentration will decrease NRep and increase the drag coefficient for different particle sizes. For non-Newtonian fluids, the settling velocity decreases with increases in CMC concentration due to increases in the viscous forces that oppose settling of particles, while in Newtonian fluids, the settling velocity increases with increasing particle size due to gravity forces increasing. The low CMC concentrations (low n, and high k) offer higher settling velocities, while larger particle sizes give lower drag coefficients than smaller ones.
Effect of fluidization on pressure drop and power consumption in packed bed columns
Authors: Qassem E S , Mohammed S H , Sarmad T N 
Published: January 2020

AbstractThis research investigated the effect of different initial heights of packed bed on pressure drop and minimum fluidisation velocity in packing bed columns. Glass beads with different sizes (6 and 8 mmdp) with density 2, 550 kg/m3were used, with distilled water as the liquid. In order to study the effect of changing the properties of water, a heater with a temperature controller was used to control the temperature of water for each experimental run at one of two levels (20 and 30 °C) to examine any changes occurring in terms of values of pressure drop at minimum fluidisation velocity.All experimental runs were carried out in a cylindrical Perspex column with a 5 cm inside diameter, 5 mm wall thickness, and 100 cm length; six pressure sensors of transducer type (analogue) were fixed on wall of the column and at bed height in order to measure the pressure; the pressure differences between any two points were thus calculable. The pressure sensors were located 10 cm apart, beginning at the bed mesh holder. The pressure data were recorded using the LabVIEW program and an Arduino.A comparison was made between a stationary (fixed) and fluidised bed by measuring the pressure drop in each case via pressure sensors at the same flow rate, temperature level, and initial height of bed. It was observed that the minimum fluidisation did not change with changes in the initial height, though pressure drop increased with the increase in initial height and both pressure drop and minimum fluidisation velocity increased with increase in temperature. The fluidisation state showed a lower pressure drop than the fixed state, reducing power consumption. For validation Octave Levenspiel’s equations for both pressure drop and minimum fluidisation velocity were applied, showing good agreement with the experimental work in terms of using the liquid as a working fluid.
Evaluation of the upstream slope stability of earth dams based on drawdown conditions - Khassa Chai Dam: a case study
Authors: Alfatlawi Thair J M , Al-temimi Yahyea K. , Alomari Zeena M. 
Published: January 2020

AbstractSudden drawdowns may cause instability in slopes without adequate levels of protection against failure. In this paper, a numerical approach utilising the finite element method (FEM) was employed to examine the seepage and slope stability of a typical earth fill dam. Finite element software (GEOSTUDIO 2012) was used to carry out both steady-state and transient seepage analyses on Khassa Chai Dam in Iraq to study the seepage and upstream slope stability after various upstream drawdown scenarios. To include water levels during evacuation, variable linear water heads with time were identified as boundary states in the transient seepage analysis. The quantity and direction of water flux, existing gradient, and safety factor were calculated for all scenarios. The results revealed that the stability of the slope during drawdown is highly impacted by how fast its pore water pressure dissipates. The results also showed that a minimum F.S. was achieved within 10 hr in the case of a 1-day water drawdown, with the F.S. reduced by 60.66%; this becomes critical when the water level in the basin drops by about 41.67% of its original height.
Estimating municipal solid waste generation from service processions during the Ashura religious event
Authors: Abdulredha M , Abdulridha A , Shubbar A A , Alkhaddar R , Kot P , Jordan D 
Published: January 2020

Abstract
Multiple religious events attended by millions of pilgrims take place across the world every year. Large quantities of municipal solid waste are therefore produced which pose serious threats to the management systems of the host cities and negatively affect their attractiveness. Accurate and reliable information about municipal solid waste generation during such events is thus valuable in terms of management planning and resource recovery applications. The current investigation thus aims to estimate waste generation from the service processions, which are temporary tents set up by Iraqis to provide accommodation and services to pilgrims, during such events. To achieve this goal, a pilot questionnaire survey and an on-site municipal solid waste audit were conducted over 20 processions during Ashura, which is one of the largest religious events in the city, being attended by up to 3.5 million pilgrims. The outcomes of this investigation indicated that municipal solid waste generation from processions broadly varied from 22 to 944 kg per day, with an average of 284 kg per day. This variation can be attributed to the number of meals provided by each procession and similar expenditures. These results can thus be taken as a starting point for introducing a proper management system to be used in Kerbala during religious events.
Assessing provisions in Eurocode2 for anchoring reinforcing bars with bends
Authors: Ajaam A 
Published: January 2020

Abstract
In Eurocode2, the design provisions allow for the anchorage length of reinforcing bars with bends to be calculated as the center line of the bar from the critical section of the member to the end of the straight portion of the bar beyond the bend, with no limit on the maximum value of the length beyond the bend (extension length). This paper thus presents statistical analysis for test results of reinforcing bars anchored with bends, collected from the literature, as a means to assess the performance of the provisions of Eurocode2. Strength of bent bars at an anchorage length depends on many parameters, including concrete compressive strength, embodied as a constant bond stress along the anchorage length; diameter of the bar; concrete side cover; spacing between bars, and confining reinforcement. Test results incorporated in this analysis include 113 simulated beam-column joint specimens with 16, 19, 22, 25, and 36 mm beam bars with stresses at anchorage failure ranging from 213 to 943 MPa, and concrete compressive strengths ranging from 18 to 114 MPa. Each specimen contained 2, 3, or 4 bent beam bars with clear spacing between them ranging from 2db
to 11.4db
. All specimens contained no confining reinforcement within the joint region and a constant concrete side cover of either 65 mm or 90 mm. The analysis showed that, for a given bar diameter, the predicted bar stress at anchorage failure with limitations as originally integrated on bond stress, concrete cover, and spacing between bars is reasonably safe. However, the ratio of test-to-calculated bar stress decreases as the ratio of extension to embedment length increases, resulting in an unconservative design when the extension length exceeds half of the embedment length. For rational designs, an upper limit on the extension length of half the embedment length is thus suggested.
Fracture Mechanism of Fibre Reinforced Concrete Pavement Based on a RILEM Design Approach
Authors: Wtaife Salam , Alsabbagh Ahmed , Shaban Alaa M. , Suksawang Nakin 
Published: January 2020

Abstract
Using fibre-reinforced concrete pavement (FRCP) offers excellent performance in terms of enhancing the concrete’s physical properties. The most popular fibres used in creating concrete for pavements are steel, polypropylene, and polyvinyl alcohol (PVA) fibres, though these come in a variety of geometries (lengths, shapes, sizes, and thickness). This paper utilises steel and PVA fibres at different low volume fractions to examine the improvement mechanism of FRC. The volume fractions of fibre (Vf) used were 0.04, 0.12, and 0.2 % and 0.3, 0.4, and 0.6% for PVA and steel hooked end fibres, respectively. There are many theoretical methods available for determining the effect of fibre inclusion on the load-carrying capacity of concrete pavements. One of these methods is analysing the stress-strain diagram (σ-ε method) according to RILEM TC-162-TDF. This paper used the (σ-ε) method to evaluate these types of fibre, showing that the stress-strain diagram, residual flexural tensile strength, and toughness are improved by adding both types of fibre. The improvement in fracture mechanisms enhances the ability of FRCP to bear stresses and moments, helping to avoid premature failure in the pavement. PVA FRC showed better performance than steel FRC in terms of supporting the external bending moment capacity, however, which reduces the thickness of the concrete required.
Development of optimal location and design capacity of wastewater treatment plants for urban areas: a case study in Samawah city
Authors: Hussien Amjad , Al-Mukaram Noorance , Mohammed Ruqayah 
Published: January 2020

Abstract
Water, and related wastewater structures, are critical factors in the existence and the improvement of civilizations. Wastewater gathering and management has a considerable effect on the climate and economy at both regional and global level, and, accordingly, it is appropriate to advance actions that guarantee effective management for wastewater, particularly in urban areas. This research thus examined the environmental and economic aspects of proposed locations for wastewater treatment plants. Samawah city, located in the southern part of Iraq, was selected as a case study for the research methodology, and for research purposes, the studied city was divided into three main zones (1, 2, and 3) of sixteen areas. The Google Earth tool was used to calculate the lowest elevations in the studied zones in order to assess the suggested positions of treatment plants. Additionally, the WinQSB program was utilised to select the most appropriate positions for treatment plants based on data obtained from local government departments. These data include population, water consumption, and required lengths and subsequent cost of pipes. This research thus developed a new strategy for assigning the locations of wastewater treatment plants.
Spatial Analyses of Traffic Conflicts to Assess Safety at Signalised Intersections
Authors: Abdul Majeed Raghad Zeki , Ewadh Hussein A. 
Published: January 2020

Abstract
Safety improvements at intersections play an important role in reducing the number and severity of crashes in roadway networks, as such locations are associated with high numbers of crashes. This paper presents an approach to assessing traffic safety at intersections by using GIS software tools to achieve spatial analyses of traffic conflicts data to enable the identification and ranking of intersections by risk instead of using crash data. Traffic conflict data were collected for nine four-legged signalized intersections in Baghdad city, Iraq through site-based observations in 2017, and archived crash data for three years obtained to conduct a comparison. Kernel density estimation was used as a spatial analysis tool in ArcGIS software to estimate conflict intensity at each location, and an Intersection Prediction Conflict Index (IPCI) used to represent the ratio of the proportion of conflicts events occurring within the identified hazard locations (hotspots within intersections) to the area covered. The results showed that the developed approach, based on the spatial properties of traffic conflict events, is efficient and reliable in terms of identifying potential hot spots and ranking sites as compared with observed crash frequency. This approach can thus be used as a tool to support effective decision making about improvements in safety at signalised intersections.
Numerical analysis of nonhomogeneous and nonprismatic members under generalised loadings
Authors: Al-Azzawi Adel A , Emad Hiba 
Published: January 2020

Abstract
This research studied the problem of varying depth and varying elastic properties along flexural member lengths subjected to generalised loading, with such members considered to be nonhomogeneous and non-prismatic. The differential equation for classical thin beams was thus derived and the finite differences used in solving this equation. Fortran programs were written to solve the problem in finite differences, and three-dimensional elements were used to simulate or model the beams in finite element ABAQUS software. A parametric study of the influence of beam width, depth, load nature, and boundary conditions on deformations and internal forces was thus accomplished. The maximum variation in deformations seen between this study and previous studies was 8%. The deflection of the non-prismatic beam was reduced by 31% when the ratio of the beam moment of inertia at different sections increased by up to three times, while, the moment capacity and the right end support shear capacity were increased by 78% and 50%, respectively.
Delay Time Analysis and Modelling of Signalised Intersections using Global Positioning System (GPS) Receivers
Authors: Alkaissi Z A , Hussain R Y 
Published: January 2020

Abstract
Delays at signalised intersection are considered the most important measure of effectiveness (MOE) for signalised intersections as these are used to determine the level of service (LOS). Thus, the aim of this research is the estimation of total delay and modelling of signalised intersections in Baghdad along the Palestine arterial street. Global Positioning System (GPS) receivers provide an opportunity to accurately measure intersection delay in terms of deceleration delay, stopped delay, and acceleration delay. The field data were collected for the selected sections of Palestine arterial street for Bab Al Moatham; AlSakhara; Beirut; and Maysaloon intersections respectively. Congestion of traffic conditions takes place during peak hours of the day, so from 12:00 to 3:00 p.m. on Mondays and Tuesdays in May 2019 were selected to study the variations of total travel time and travel delay times for each intersection in the selected sites. GPS essential measurement equipment running on cell phones was applied to compute the delay components for each group’s set of data points recorded at peak periods on each selected intersection corridor. A total of 60 test runs were carried out in the north and south direction in each case. The obtained results indicated that the stopping time for vehicles represents the major part of total control delay reaching about 88% of the control delay at some signalised intersections (Beirut and Bab Al Moatham intersections) at peak hours. The acceleration delay time was also higher than the deceleration delay time. GPS was also shown to be an effective field tool to accurately measure intersection delay as composed of deceleration delay, stopped delay, and acceleration delay for oversaturated traffic conditions.
Modelling Stilling Basins for Sewage Networks
Authors: Mohammed Shahad R. , Nile Basim K. , Hassan Waqed H. 
Published: January 2020

Abstract
Concrete elements play an effective role in stilling basin design in terms of enhancing the dissipation of energy to prevent immoderate scouring of downstream structures. Proper appurtenances, such as wedge-shaped splitter blocks, baffle walls, inverted t-sections, rectangular walls, inverted L sections, and impact walls, are thus utilised with circular pipe outlets to create stilling basins that are shorter yet more effective, and thus more economical. This research was based on numerical analysis of stilling basins using FLOW-3D software; the resulting Froude numbers were compared with the Froude number of a case study, a stilling basin manhole created by the Karbala Government. This research thus examined the influence of Froude number, the arrangement and location of dissipators, and the height of the pipe inlet under different hydraulic condition in order to better simulate stilling basin models. The turbulent energy dissipation was found to vary from 16% to 85%. The results from the models showed that L-sections offered maximum turbulent energy dissipation (ΔE/E1), while the rectangular wall shape gave minimum turbulent energy dissipation (ΔE/E1). It was also observed that the maximum turbulent kinetic energy almost always occurred in the initial sections, with flow becoming generally less turbulent at the end sections. Thus, at the end of all stilling basins, the turbulent kinetic energy dissipation and turbulent kinetic energy profiles became more uniform. The proposed numerical simulation using FLOW-3D was shown to be a reliable tool for predicting and discussing the turbulent energy dissipation in stilling basins. Further conclusions included the fact that the maximum turbulent energy dissipation (ΔE/E1) increases as values of Fr increase. The results of this research could thus help hydraulic designers to consider their selections for the optimum design of stilling basins more carefully.