bluuebunny/crossref_metadata_2025_split huggingface dataset:
Shear Performance of Hybrid Concrete Deep Beams of Trapezoidal Section
Authors: Sada Majid Jafar , Resan Sa’ad Fahad 
Published: March 2021

AbstractThe structural behaviour of hybrid reinforced concrete beams of trapezoidal section was investigated in this work. The main aim of study was to investigate the interaction effect of hybrid concrete compressive strength–section geometry variations on beam strength characteristics. The experimental programme included fourteen simply supported reinforced concrete deep beams being prepared and examined under a four-point load setting protocol. All specimens were of 1,000 mm length and of equal cross-sectional area. The specimens were divided into groups according to section shape variations and hybrid compressive strength considerations. Various concrete compressive strengths (70, 50, and 25) MPa were considered, and three different trapezoidal geometries of different alignment side angles (75°, 80°, and 85°) were also adopted, along with two steel rebar ratios (0.008617 and 0.01508). Generally, the experimental results showed that the shear strength capacity increased with increases in the area of high-strength concrete in the compression zone in increments, with improvements ranging from 3.66% to 8.63% as compared to reference specimens of uniform section (rectangular section); the diagonal crack load decreased, however. It was also observed that the hybrid concrete created high ductile behaviour, and the significant failure mode was shear mode without slippage of the hybrid concrete layers. A comparison of results with the hybrid strength reduction index (Ψ=f’cb/f’ct) showed that as Ψ decreased from 0.714 to 0.357, the average rating varied between 1.15 and 1.22 with respect to rectangular specimens and from 1.07 to 1.13 with respect to trapezoidal sections of uniform strength. An optimum alignment side angle for trapezoidal configuration also appears to be indicated, with the best results for all hybrid strength-trapezoidal sections in specimens where Ө=80°.
Perception Of Architectural Output: The Presence Of Architecture In The Presence Of a Pandemic
Authors: Kadhim Ibrahim Jawad , Ubaid Wasan Jawad 
Published: March 2021

Abstract
The importance of the fourth dimension in architecture is based on its use to determine the effectiveness and structure of four-dimensional space through perception; how people livesin architecture and move within spaces is affected by the ways their senses become accustomed to what they see and perceive. New intellectual responses are generated by both new formations and circumstances, generating the research problem focused on the role of architecture with respect to recognising the current pandemic and its effects on architectural production. The research goal was thus to achieve a new perception of architecture by adding the fourth dimension of time as one of the component dimensions within the system of change that architecture must develop in response to the pandemic; this can be achieved by creating broader horizons within classic theories in an attempt to formularise architectural products that adopt the fourth dimension to address issues arising from the pandemic. The research method included inductive, analytical, and interpretive approaches, examining various theories and concepts to arrive at a set of values, and the results were a set of mental concepts that describe an architectural perception of the pandemic, based on interaction, which provide a knowledge base for developing awareness of the pandemic through architecture.
Physically and chemically treating sulphurous water in western of Iraq
Authors: Khudair M. Y. , Al-Hadithi Y.K. 
Published: March 2021

Abstract
The agricultural sector in Iraq is one of the country’s most water-consuming sectors. Recent shortages of fresh water have made it necessary to utilise treated water, whether sewage water, sulphurous water, or industrial water, for such purposes to preserve the available water resources. A laboratory experiment was therefore conducted to study the effects of different physical and chemical treatments on sulphurous water intended for irrigation. The chemical treatments used were bentonite, nitric acid, activated carbon, and manganese oxide, while the physical treatment process examined was ventilation of various durations. The results showed that all treatments led to a reduction in the concentrations of iron, hydrogen sulphide, and sodium in the treated water, and that all methods of treatment and concentrations led to the reduction of SAR in the treated water. Some treatments led to an increase in the electrical conductivity, namely bentonite and nitric acid, while the other treatments led to lower electrical conductivity. All treatments and concentrations led to an increase in the concentration of magnesium in the water compared to that in the untreated water, which is considered a positive indicator.
Evaluating Porous Pavement for the Mitigation of Stormwater Impacts
Authors: Al-Busaltan Shakir , Kadhim Mustafa Amoori , Nile Basim K , Alshama Ghofran A. 
Published: March 2021

Abstract
Urban stormwater management is one of the biggest challenges facing modern cities. The current stormwater networks are likely to be insufficient under continuous urbanisation and the development of residential areas in addition to increases in rainfall intensity, especially in areas with relatively high slopes, which may thus be subject to flooding. This study aimed to mitigate the overflow rate of the selected case study area using a pervious inlets pavement technique based on porous asphalt concrete pavements with a reservoir layer. The current stormwater network system of the Al-Yarmouk quarter (located at the centre of Karbala City, Iraq) was evaluated by exposing it in simulation to a rainfall intensity equivalent to the 5-year return period and applying storm and sanitary analysis (SSA) and GIS software. The simulation results showed that constructing 50% of the road surface area (5% of the total studied area) with porous asphalt concrete with air voids of about 20% and variable reservoir thicknesses, could reduce water runoff entering the network significantly. Moreover, placing 240 mm, 328 mm and 400 mm of No.75 aggregate layer within reservoir depths would result in further mitigations of surface runoff quantity by about 15%, 30%, and 45%, respectively. A reservoir depth of 240 mm was found to reduce flooding quantities and times by about 71% and 18.29%, respectively, while creating a 328 mm reservoir depth under the porous asphalt results in quantity and time reductions of about 98.5% and 81%, respectively. No surface flooding was observed when reservoir depth was changed to 400 mm.
Experimental and finite element analysis of mechanical behavior of concrete damaged by Alkali Aggregate Reaction (AAR) and repaired with CFRP Layers
Authors: Kadhim Roaa A , Al-Taie Rania S , Al-Mahaidi Prof Riadh 
Published: March 2021

Abstract
Concrete structures is affected by a deleterious reaction, which is known as Alkali Aggregate Reaction (AAR). AAR can be defined as a chemical reaction between the alkali content in the pore water solution of the cement paste and reactive forms of silica hold in the aggregate. This internal reaction produces expansion and cracking in concrete, which can lead to loss of strength and stiffness. Carbon fiber-reinforced polymer (CFRP) is one of the methods used to suppress further AAR expansion and rehabilitate and support damaged concrete structures. In this research, thirty-six cylindrical specimens were fabricated from non-reactive and reactive concrete, which contained fused silica as 7.5%. In addition, twelve concrete prisms were fabricated from non-reactive and reactive concrete in which three different percentages of fused silica are used, 5%, 7.5% and 10% of the total aggregate. This paper investigates the impact of AAR expansion on the physical and mechanical properties of concrete. It also reports the effective use of one and two CFRP layers on wrapping concrete cylinders. The experimental results show that CFRP is effective in confining damaged concrete by AAR and results in concrete strength enhancement of up to 560%. A comparison of finite element (FE) analysis using ATENA 3D software and the experimental results indicated that FE analysis is capable of modelling the behavior of AAR-damaged concrete repaired with CFRP.
Study of Various Techniques for Estimating the Generalised Extreme Value Distribution Parameters
Authors: Hossain Iqbal , Imteaz Monzur , Khastagir Anirban 
Published: March 2021

Abstract
Generalised extreme value distribution (GEVD) remains the commonly employed technique for investigating the probability of occurrence of extreme events for given recurrence of intervals. However, the application of the GEV distribution requires the estimation of its three parameters. There are different methods presented in the literature to determine the parameters of the GEVD. Different methods have been adopted by different researchers in determining the three parameters. This paper investigates the comparison of the commonly used methods to estimate the GEVD parameters. The maximum likelihood estimation (MLE), generalised maximum likelihood estimation (GMLE) and L-moments methods were considered in this study. The analysis was performed using the monthly extreme rainfall of Tasmania, Australia. The GEVD was fitted to four different data sets using the three parameters estimation techniques. The outcomes of the analysis suggest that parameters estimation techniques have negligible impact on the magnitude of the parameters. However, length of the data series has minor impact on the parameters value of different parameters estimation techniques.
Efficient environmental architectural design for educational buildings in Iraq: An environmental study of the computer engineering building in the University of Technology, Iraq
Authors: Hameed Haddad Ahmed Talib , Abbas Kais Abdulhusein , Challoob Ahmed Abed 
Published: March 2021

AbstractThe topic of the thermal environment of architectural buildings is important in current architectural design. This research thus discusses the state of the computer engineering building in the University of Technology of Baghdad through the lens of climate elements and the principles of sustainability with the aim of achieving increased comfort for those occupying this building during office hours.The research thus proposes several solutions including creating a mask for the building, as well as making decorations commensurate with the goal that highlight elements of Arab Islamic architecture while also creating shadows that may decrease direct solar radiation. Further ideas include tilting the glass inwards in some windows, and replacing the capon panels with concrete structures that separate then from the building to create a buffer distance, as well as shifting room locations from one place to another, and adding afforestation around the building in a thoughtful manner.
Failure evaluation of composite concrete using an acoustic emissions technique
Authors: Al-Jumaili Safaa Kh , Jassim Ahmad K , Ali Dhia C 
Published: March 2021

Abstract
One major problem with concrete is high brittleness with low tensile strength and strain capacity, which can cause sudden failure. Structural Health Monitoring (SHM) is thus very important to detect cracks in initial stages to avoid catastrophic failure. In this research, an acoustic emissions (AE) technique was applied to enable SHM to detect cracks and predict the failure of composite concrete. This physical non-destructive testing process utilises transient elastic waves caused by the rapid release of energy from a localised source within a structure. A low-frequency acoustic emission system was thus tested for economical monitoring of the damage to reinforced composite cubic concrete under compression. Specimens of standard size (150 x 150 x 150 mm) were produced without and with polyamide reinforcement bars. The compression strength of the cubic concrete was then tested according to BS EN 12390-1. Prior to testing, a low-cost single piezoelectric wafer active sensor was applied to the centre of one side of each specimen, which was then connected to a PC’s sound card. Data was successfully recorded using sensors and the real-time of the applied load was recorded using a separate data logger. Traditional AE signal parameters were extracted and used for damage evaluation. The results indicated that the AE system was capable of detecting cracks in representative structures to final failure. Signal amplitude with load versus time showed an increase in AE activity and energy approaching the end of the test, while commutative hits could be used to distinguish between stable and unstable loading stages. The system also detected the initiation of the final failure stage at 72.6% and 83% of the failure load of specimens without and with polyamide reinforcement bars, respectively.
Evaluating the mechanical properties of thin asphalt overlay incorporating reed ash
Authors: Abduljabbar Nadia , Al-Busaltan Shakir , Dulaimi Anmar 
Published: March 2021

Abstract
Thin Asphalt Overlay (TAO) is a preservation maintenance technique that has been shown to overcome shortcomings in the functional properties of surface pavement layers. Although TAO is not a structural layer, its application sustains the pavement’s structural strength and increases its lifespan, which is a valuable effect for the paving industry. Due to recent realisation of the limits of natural resources and the high cost of raw materials, the paving industry has also developed a secondary target of incorporating waste materials as an alternative to conventional raw materials, both to reduce environmental pollution and minimise costs, in such applications. This study focuses on evaluating the effect of using reed ash (RA) in this manner on the mechanical properties of TAO. The control TAO mixture was densely graded, with a 9.5 mm nominal maximum aggregate size (NMAS) utilising a 40/50 asphalt binder grade. Three percentages of RA were incorporated, 6%, 12% and 18%, to produce modified asphalt binder. To verify the effect of this material on cracking behaviours, resistance to permanent deformation of TAO, indirect tensile strength, creep compliance, and wheel track tests were carried out on both control and modified asphalt mixtures. The results showed a significant enhancement in the performance of TAO modified with 6% RA as compared to the control mixture, although the very high dosage of 18% reduced the performance of the relevant TAO mixtures. This study thus indicates that using this waste material can offer an alternative solution for asphalt cement modification, increasing sustainability, if dosages are carefully controlled.
Analysis of the Euphrates River’s movement within Al-Hindiya, Karbala, relative to steady flow conditions using the HEC-RAS model
Authors: Saleh Layla Ali Mohammed , Majeed Sumayah Amal Al-Din , Algretawee Hayder H. 
Published: March 2021

AbstractThe steady flow condition is considered to be the dominant case for multiple rivers around the world. River studies thus necessarily focus on this condition, including those in Iraq, which has two rivers running from north to the south. In this study, the HEC–RAS program was applied to steady flow analysis of the Euphrates River within Al-Hindiya in Karbala. The case study was executed for the whole city of Al-Hindiya by selecting 12 km length of the river and dividing it into 30 sections. Field data for 2019 was thus used to develop three profiles for discharge at minimum, normal, and maximum magnitudes, which were 90 m3/sec, 250 m3/sec, and 445 m3/sec, respectively. The results showed that the maximum variation ratios in velocity between sections were 80%, 70%, and 72% for the minimum, normal, and maximum profiles, respectively, with the variation ratios in water level between reach ends being 4%, 6%, and 5% and the slopes of energy grade lines were about 0.009%, 0.015%, and 0.013% for the three profiles respectively. In addition, the regression analysis of the results revealed that the relative energy losses between any two adjacent sections are linked strongly to the relative change in water level for the normal and minimum profiles, with coefficients of determination R2= 0.88 and 0.96 for these profiles, respectively; however, for maximum discharge, the relative energy losses were related to the relative change in both velocity head and water level, withR2=0.94.
Effects of linear modification on the performance of finite length journal bearings
Authors: Al-Mosawy H A , Jamali H U , Tolephih M H 
Published: March 2021

Abstract
Journal bearings are widely used in industry due to their favourable characteristics such as relatively low cost of manufacturing and maintenance, high load carrying capacity, and useful dynamic characteristics for rotor systems. Journal bearing misalignment, however, may have negative consequences for the general performance of this type of bearing. Misalignment commonly occurs due to errors in manufacturing tolerances, installation errors, wear, shaft deflection, and asymmetrical loading of systems. This paper presents a solution for hydrodynamic problems in journal bearings of finite length based on a 3D misalignment model and linear modification of the bearing profile to reduce the effect of misalignment on the characteristics of the journal bearing. The results showed that linear modification of misaligned journal bearings reduces the maximum pressure and improves the level of film thickness; additionally, the dynamic characteristics of the journal bearing are also improved by such linear profile modification.
Solar cooling modelling utilising for cooling agro-products cold store under Rwandan environmental conditions
Authors: Alammar A A , Rezk A , Alaswad A , Ruhumuliza J , Gasana Q G 
Published: March 2021

Abstract
Solar-driven cooling systems can be considered as a sustainable solution for the weak cold chain. Transient Simulation System (TRNSYS) offers component-based 0D modelling capability of different engineering systems. TRNSYS has been employed to model a year-round performance of a PV solar-driven electric chiller to meet the cooling demand of post-harvested foodstuffs under Rwandan metrological data. Various PV module sizes and batteries storage capacities have been investigated to examine their effect on the solar energy fraction powering the electric chiller to maintain the room at the desired temperature. In addition, two different arrangements of chilled water loop, namely one-loop with 3 KW chiller capacity and two-loops with 6 KW chiller capacity have been compared to investigate their effect on the chiller performance and solar fraction. Results revealed that the later arrangement exhibits a higher solar fraction compared to one loop despite the addition of another pump. For 35 PV modules, the two-loops arrangement requires 42 kWh battery capacity to provide about 90% solar fraction, while one-loop needs 66 kWh to deliver the same solar fraction. Accordingly, the battery storage capacity is reduced by a factor of 0.36 which justifies the increase in the chiller capacity from 3 KW to 6 KW. This study provides a selection map to choose between the number of PV panels and batteries capacity required to power the chiller and meet the cooling load.
A Review of Solar Energy Harvesting Utilising a Photovoltaic–Thermoelectric Integrated Hybrid System
Authors: Aljibory M W , Hashim H T , Abbas W N 
Published: March 2021

Abstract
Solar energy has the potential to be converted from light to electricity; however, solar cells can only utilise the short-wavelength portion of the solar spectrum to do this directly. In contrast, long-wavelength portions of the spectrum can be converted to heat inside solar cells, and such heat can be harvested and converted into electricity by means of a thermoelectric generator (TEG). The integration of photovoltaic and thermoelectric hybrid systems has thus attracted a great deal of attention due to these offering the ability to utilise solar energy across the full spectrum, including light and heat. This paper reviews the possibility of integrating photovoltaic (PV) and thermoelectric generators (TEG) in a PV-TEG hybrid system based on examining recent efforts in the field of PV-TEG creation. It also examines the efficiency improvement in PV-TEGs and their applications in recent years, offering a valuable guide for researchers and designers.
Optimization-based Component Sizing Method for Electrified Heavy-Duty Powertrain Concepts
Authors: Roth D. , Habermehl C. , Jacobs G. , Neumann S. , Juretzki B. , Bayer D. 
Published: March 2021

Abstract
The demand for battery-powered, exhaust emission-free mobile machinery is increasing. However, the high energy requirements of mobile machines result in large, heavy and expensive battery storage systems. Driven by continuously decreasing but still fairly high battery costs battery costs, the efficiency of the drive system is becoming the focus of development activities, even in an industry where robustness, service lifetime, productivity and power density have been the driving factors up to now. Interactions between topology, component sizing, and control strategy require a system-level approach for the development of drive systems. In this paper, a novel optimization-based sizing method for electrified heavy-duty powertrain concepts is presented and applied to subsystems of a wheeled excavator. Scalable component cost and efficiency models are used in a system simulation to calculate objective function values for a multi-objective optimization. The result of the optimization, a trade-off between energy consumption and costs provides the OEM with a decision support in the development process. The modular structure of the approach allows a subsequent extension of the design parameter space as well as the detailing of the models used.
Tribological analysis of the plain bearings in an external gear pump
Authors: Brinkmann Lars , Kock Stefan , Lang Jochen , Knoll Gunter 
Published: March 2021

Abstract
Tribological loads in the plain bearings of external gear pumps are influenced by system-specific parameters (e.g. elasticity of the components, micro-geometry and manufacturing tolerances) and the operating point (rotation speed, operating pressure and temperature of the pressure medium). Due to the pressure build-up in the tooth chambers, fluctuating radial forces are acting on the gear shafts and lead to complex deformations of the bearing bushings and the housing. These deformations have an influence on the tribological loads in the plain bearings. To decrease tribological loads and failure rates, it is possible to modify the plain bearings in terms of their micro-geometry (e.g. clearance and contours) or to take constructive measures on the overall system (e.g. on the bearing bushings). Therefore, it is necessary to understand the influences of external loads, elastic environment and micro-geometry on the tribological loads in the plain bearings. This paper describes the first steps to understand these interactions by building up a simulation model of a specific external gear pump using the MBS/EHD-tool FIRST developed by IST [1]. The focus is to evaluate the required modeling depth regarding the consideration of an elastic housing.