bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of Hybrid-Modified Asphalt Mixtures Performance Using Bending Beam Rheometer
Authors: Abed Mohammed A , Abed Alaa H
Published: August 2020

This study elucidate a test methodology to execute the creep tests to assess the performance of the hot asphalt mixture (HMA) beams by utilizing the bending beam rheometer (BBR) and explain the most issues related to performing this test. Firstly, a comprehensive samples preparation technique has illustrated and the experimental data were presented to evaluate the reliability of this technique. To perform this test, one aggregate gradation and two types of polymer modifiers with three percent of modification for each type of polymers were used. However, experimental results showed that decreasing the testing temperature by an increment of 10 oC can reduce the deflection by 95.6, and 99.13%. Decreasing the temperature from 25 to 15 and 10 oC can increase the creep stiffness by 12.6 and 36.6 time. Which indicate that temperature was a predominant factor affecting the most responses of the hot asphalt Mixtures. besides polymer modification significant effect on the stiffness which is clear that using 4, 6, and 8 % of SBS can increase the creep stiffness by 9.8, 44.6 and 196 % respectively. Although, the hybrid modification had been increased the creep stiffness for asphalt mixtures by 16.3, 72.5, and 186.7% respectively.
Monte carlo simulation for stability of finite slope subjected to earthquake loading
Authors: Al-Gharrawi Asaad M. B. , Abdul-Husain Husain Ali
Published: August 2020

Analysis of finite slopes is a common practical problem which faces the geotechnical engineering. The aim of the slope analysis is to predict the safety factor against shear failure of the slope which is the ratio between the resisting and the disturbing forces developed along an assumed slip surface. Presence of seismic forces due earthquake lead to more critical situation. The deterministic approaches are employed for this purpose. These approaches do not take into account the uncertainty related to soil properties and/or seismic loads in their procedures. In the present work, a probabilistic approach is adopted using the Monte Carlo simulation technique to study the effect of uncertainty due to soil properties (unit weight, angle of internal friction and cohesion) and seismic accelerations (vertical and horizontal). The results of the work demonstrate that the use of probabilistic approach will yield more accurate results for estimating the safety factor and then economic design of the slope. Also, the results reveal that the statistical properties for the soil shear strength parameters have significant impact on the standard deviation of the output (factor of safety), while the soil unit weight and horizontal acceleration have small effect. However, the vertical acceleration has no effect on it. On other hand, the mean of the output distribution does not affect by the statistical parameters of all input variables. All cases simulated in this study give reliability index (RI) less than 3. Hence, RI values indicate that there are unsatisfactory level of safety for the slope subjected to seismic loading. Finally, the soil shear strength parameters have the same positive significant impact on the safety factor. But, the soil properties and the coefficient of the horizontal acceleration should be selected carefully in the stability analysis due to the effect of their uncertainty on the analysis results.
Behavior and Failure Mode of GFRP bars RC Beams under Elevated Temperature
Authors: Al-Thairy Haitham , Al-hasnawi Nuha Hussien
Published: August 2020

The presented work is providing the results of experimental study to investigate the impact of elevated temperature on load resistance related to the concrete beams that are reinforced via the glass fibre reinforced polymers (GFRPs). There are four GFRP reinforced concrete beams with width (250mm) and height (160mm) as cross-sectional dimensions, also (1250mm) as total length have been designed according to ACI440.1R-15[1], cast using normal weight concrete and considered in the experimental tests. One specimen has been put to test at ambient temperature, while other three specimens were firstly exposed to increased temperatures (350, 500, and 600 °C), after that subjected to a monolithically increased one point load up to failure. The effect of increased temperature on load displacement relationships as well as the failure modes regarding tested beams were discussed and put to comparison with the results related to the control beam (20°C). The experimental tests results have indicated that the shear failure is the pre-dominate failure mode with regard to all the tested GFRP-beams before and after exposing to elevated temperature. Results have also shown that in comparison to the control beam (20°C), reduction in loading capacity of heated reinforced concrete beams have been 4%, 15.5% and 19% when exposing to temperature of 350°C, 500°C and 600°C respectively.
Reliable prediction of structure settlement in Al-Najaf city using laboratory testing
Authors: Mahmood M S , Almahbobi S H , Rabee A M , Rahim A M , Naama M A , Mohammed M F
Published: August 2020

This paper studies the effect of the specimen sizes and shapes on the settlement behaviour of sand soil with gypsum from Al-Najaf city in Iraq. The investigation aimed to verify the impact of the studied parameters of the prediction of the settlement using reliability-based analysis. Three sets of soil samples with different shapes and sizes, 60 mm diameter Oedometer cell, 60 x 60 mm box container and 100 x100 mm box container were remoulded with three different densities related to the maximum dry density, 100%, 95% and 92%. The results reveal that different settlement behaviours were determined at several normal stress levels during the soaking process. The samples exhibited reductions in volume due to the applied stresses, while under the same level of normal stress, the final settlement values due to soaking were higher for the samples with a lower value of initial relative compaction. Further, the test results showed that at any initial relative compaction and applied vertical stress, the higher settlement value is achieved by the larger square specimen (100x100)mm.
Changing bolt arrangement and their effect on bearing capacity of single shear connections
Authors: Jawad Faris A , Dheyab Hasanain M , Jasim Heydar A
Published: August 2020

In steel structures, bolted joints are used to connect structural elements. Due to the ease of its making, the square and rectangle arrangement of bolts are the prevalent pattern in these structural joints. To investigate the effect of changing the arrangement of bolts on the bearing capacity of single shear joint, square, circular and diamond are the patterns of bolts that have been chosen in this study. Nine specimens represent all these configurations experimentally have been tested under tension load. The results indicated that the highest bearing capacity of a single shear connection could be achieved using a square arrangement of bolts. While stresses could not be equally distributed around holes in circular and diamond pattern specimens of the same connection.
Effect of Contraction Joints on Structural Behavior of Double Curvature Concrete Dam Subject to Dynamic Loading
Authors: Khassaf Saleh Issa , Chkheiwr Aqeel Hatem , Jasim Mohammed Abdulrahim
Published: August 2020

A double curvature arch dam considers as complex mega structure built for the hydropower or agriculture national goals. Arch dam cost effective is less compared to other types of dams, construction a safe and stable of arch dam depending on intelligent formation of dam layouts. This work conducted to explore the structural behavior of the double curvature arch concrete dam under the variation effect of the distance in between the contraction joints. The dam blocks divided and distributed as seven intervals of the distance between the blocks of the dam as 15,17.5,20,22.5,25, 27.5, and 30 m. Stresses analysis of arch dam conducted to study the effects of these intervals on the structural behavior of double curvature concrete dam when the water in the reservoir at the operation level. Arch dam data input considered the Nonlinearity in both of dam shape and concrete materials properties to evaluate the maximum and minimum principal stresses at the top of the crown cantilever, and the maximum principal stresses along the crest path of the upstream face. Finite element and building information modeling tools (Revit – Abaqus6.13) were considered during the modeling and analysis process. The results show that the dam must be simulated for a specific interval of distance between each two contraction joints are 20 to 22.5 meter and the optimum selection to this interval of contractions joints leads to increase the structural stability status of the arch dam.
CFD Based Model to Identify the Minimum Length of a Gradual Rectangular Expansion Operated under Supercritical Flow
Authors: Hassan Fadhel A.
Published: August 2020

Computational Fluid Dynamics (CFD) has been used to derive a mathematical model to relate the length of a gradual expansion (Le) with the others of hydraulic and geometric parameters of the flow in rectangular channels under supercritical flow conditions. Five models with different length of expansion 30 cm, 50 cm, 75 cm, 100 cm, and 125 cm were simulated in the CFD v18.2 software and verified by experimental data which have been measured into a laboratory flume. All models of CFD software were processed depending on k – epsilon viscous models while the mesh was built by adapting the multi-zone method. Five values of inlet velocity of flow were applied in the runs of the program to each model of 1.5 m/s, 1.6 m/s, 1.7 m/s, 1.8 m/s, and 2 m/s. Depths of water along the channel were measured in multi-section, before expansion, within expansion and after expansion. The results of CFD analysis showed that the minimum length of expansion to maintain the flow within supercritical regime was 0.35 m and the ratio of (Le/W) equal to 1.167. The results of the non-dimensional relationship were compared with the experimental results and the comparison showed a significant correlation where the highest percentage difference was 13.8 %. The coefficient of determination for this equation was 0.973.
Zeolite-assisted electrocoagulation for remediation of phosphate from calcium-phosphate solution
Authors: Alenezi Ahmad K. , Hasan Hussein A. , Hashim Khalid S. , Amoako-Attah Joseph , Gkantou Michaela , Muradov Magomed , Kot Patryk , Abdulhadi Bareq
Published: August 2020

Phosphorus is crucial to the growth of the skeletons and the living cell. However, elevated phosphate concentrations represent a problem due to its grave impacts on human health, animal and also because of its effects on water quality and economy. This research studies the applicability of filtration-electrocoagulation (filtration - EC) system to remove phosphate from wastewater when calcium is present as competitor ions. In laboratory batch trials, the ability of zeolite filter-electrocoagulation system to eliminate phosphate from artificial wastewater samples, in the presence of calcium as competitor ions, was tested. The research was initiated by studying the ability of the electrocoagulation method (EC), as a separated treatment unit, to remove phosphate from solutions that containing calcium ions. In this phase of the study, the influence initial pH, current densities and electrolysing period. Then, the new method, filtration-EC, was applied to treat solutions (with identical chemical composition to that used in the first phase) considering the effects of the initial pH, current densities, contact periods (in the filter), electrolysing period (in the EC cell) and zeolite dosage. The results of this research evidenced that the filtration - EC system completely removes phosphate from calcium-phosphate solution at pH, current density, dosage of zeolites, contact period and electrolysing period of 7, 2.0 mA.cm−2, 150.0 g, 30.0 minutes and 20.0 minutes, respectively.
Treatment of effluents of construction industry using a combined filtration-electrocoagulation method
Authors: Alyafei Ali , AlKizwini Rasha Salah , Hashim Khalid S. , Yeboah David , Gkantou Michaela , Al Khaddar Rafid , Al-Faluji Duaa , Zubaidi Salah L.
Published: August 2020

One of the significant sources of water pollution is construction industry as it requires considerable freshwater amounts during manufacturing of concrete, mortars and other construction materials. Vast volume of the used water is discharged back to source of freshwater as extremely polluted effluent (high level of suspended solids and pH), which is categorized as hazardous wastewaters. Therefore, environmental regulations prevent discharging these effluents before conducting adequate treatment. As a result, efficient treatment solutions for these effluents become necessary in the field of construction industry. In this context, this research aims at treating construction industry effluents using an integrated method, which involves adsorption (AD) and electrochemical (EL) techniques, to treat effluents of concentration sites. Turbidity and chemical oxygen demand (COD) were selected as pollutants models due to their wide occurrence in this type of effluents. 200 mg of activated carbon (AC) and four aluminum electrodes were utilized to construct the adsorption and electrochemical units, respectively. Aluminum and AC were used here as they are economically efficient, safe, and have a proven efficiency in waters/wastewaters treatment. The influences of initial pH, retention time (RT) and electrolyzing time (ET) on the removal of COD and turbidity using the new method (AD-EL method) were examined. The results demonstrated the AD-EL decreased COD and turbidity by about 72% and 85%, respectively. The perfect conditions to reach this removal levels were pH, RT and ET of 6, 30 minutes and 20 minutes, respectively.
Removal of organic matter from water using ultrasonic-assisted electrocoagulation method
Authors: Zanki Ayat K. , Mohammad Faris H. , Hashim Khalid S. , Muradov Magomed , Kot Patryk , Kareem Mohanad Mousa , Abdulhadi Bareq
Published: August 2020

Organic matter (OM) is commonly occur in freshwaters, and it poses a threat for health and environment. For instance, high OM concentrations increase the sludge volume and cost of the treatment process in turn. Remediation of water or wastewater from OM has thus become an important issue for the treatment industry. Electrocoagulation (EC) is one of the preferred techniques of treatment for remediation of water from OM and other polluting chemicals, as it utilises simple and easy to run machines and tools, it requires less working area in comparison with conventional methods, and it is more rapidly pollutant separation than other methods. EC technique could be described by passing an electric current through sacrificial electrodes to produce metal hydroxides that separate dissolved contaminants from aqueous phase. On the other hand, the EC method has a limited efficiency in the treatment of high OM concentrations. The present study is thus intended to develop a new technique that combines an EC reactor with an ultrasound (US) field to remediate water from OM. The EC reactor, in this study, was made from four aluminium plats (500 cm2 in gross area) and plastic container (1 L in volume). The operation of this combined method was optimised for the effects of key factors, such as the pH of solution, electrodes gapping, and current density. The obtained results proved that the US-EC technique removed 97.50 % of OM after 5.0 minutes of US irradiation, 20 minutes of electrolysing at current density 4.0 mA. cm−2, initial pH 7 and gap between electrodes 5.0 mm.
Natural filtration unit for removal of heavy metals from water
Authors: Abdulraheem Fatemah S. , Al-Khafaji Zainab S. , Hashim Khalid S. , Muradov Magomed , Kot Patryk , Shubbar Ali Abdulhussein
Published: August 2020

Occurrence of iron in the potable water is responsible for several issues related to environmental, economic, and public health. Water remediation from iron is very vital step for ensuring the safety of potable water. Hence, many treatment techniques, such as chemical precipitation and reverse osmosis, have been proposed in recent literature. However, these methods are either expensive or possess some negative environmental impacts. This paper therefore studies the possibility of utilizing farms’ wastes (straw and reed) to produce a filtration system for remediating water from iron ions. This natural filtration cell (NFC) was manufactured by mixing equal weights of straw and reed (1:1 ratio), while the artificial iron solution (10.0 mg.L−1) was synthesized by dissolving suitable amount of iron sulfates in deionized water. This artificial solution was treated in the NFC at different retention times (RTS) (ranging from 10 to 90 minutes) and initial pH of solution (IPS) (ranging from 4 to 9). The remaining iron in the solution, during the course of filtration process, was calculated utilizing a spectrophotometer and a standard iron cuvette test. The outcomes of this study revealed that 33.1% of iron was absorbed at RTS and IPS of 80 minutes and 7.0, respectively. Even though the research’s outcomes proved that the NFC possesses an acceptable capacity for iron removal from water, light brownish color was formed in the produced water, so another suitable treatment technique is needed to decolorize the produced.
Electrochemical removal of brilliant green dye from wastewater
Authors: Aqeel Khalifah , Mubarak Hayfaa A. , Amoako-Attah Joseph , Abdul-Rahaim Laith A. , Al Khaddar Rafid , Abdellatif Mawada , Al-Janabi Abuduljaleel , Hashim Khalid S.
Published: August 2020

Dyes are one of the most widely used materials in many industrial fields as coloring agents such as textile, wood, and food manufacturing. As these dyes end up in a water source, this high rate of dyes use represents one of the severe risks to the environment and health organizations. Most of the dyes are considered as highly toxic compounds and dangerous to the environment and human health as it consists of heavy metals, carcinogenic elements, oxygen – absorbing chemicals, and other toxic compounds that need to be well treated before discharge them back to environment. As a result, federal legislations have directed that all industrials that waste dyes-containing effluents to ensure a full dyes removal before discharging their effluents back to water bodies. Industries have applied many different treatment methods including physical, chemical, and biological methods in order to meet the required legislations. In recent years, many industries started to use electrocoagulation as the main treatment method. This study is focusing on using electrocoagulation (EC) method to remediate artificial colored effluents from coloring agents (brilliant green dye (BG dye) as a model). Electrocoagulation reactor, uses aluminum electrodes, was employed to remove this dye under different initial pH (40-10.0), direct currents (DC) (244-732 mA), and spaces between electrodes (SBE) (4-12 mm). According to the findings obtained, EC was highly efficient in treatment of colored effluents; 95.3% of BG dye was removed at treatment time, SBE, DC and pH of 30 minutes, 4 mm, 488 mA and 7.0, respectively.
Cost-effective hybrid filter for remediation of water from fluoride
Authors: Alhendal Mohammed , Nasir Mohsin Jasim , Hashim Khalid S. , Amoako-Attah Joseph , Al-Faluji Duaa , Muradov Magomed , Kot Patryk , Abdulhadi Bareq
Published: August 2020

Incidence of fluoride concentrations in drinking water above the allowable limit (1.5 mg/L) leads to varied health issues. However, fluoride concentration below 1.5 mg/L in drinking water is useful for teeth and bones health. A considerable concentration of fluoride is naturally released to the sources of freshwaters from the geological environment, specifically the groundwater, because of the weathering and seepage of water phenomena influences. Unfortunately, nowadays world population depend on groundwater as the main drinking water source, which means those people are exposed to fluoride contaminations. As a result, contamination of groundwater with fluoride has been lately considered as a universal grave issue. Although fluoride could be removed from drinking water using efficient methods, such as reverse osmosis and filtrations, there is a challenge to develop a cost-effective practical removal method. This study examines the efficiency of an economically-efficient a hybrid filtration cell (HFC), which utilizes limestone and activated carbons, for fluorides removal from water. Batch flow experiments were conducted using HFC to remediate artificial water from fluorides. Additionally, the influences of initial pH, initial concentration of fluoride (IFC), water temperature (WT) and adsorbent dosage (AD) were optimized, using Box–Behnken approach, to reach the highest removal of fluorides. The results demonstrated that fluoride could be completely removed from artificial water when the HFC is run at pH of 5.0, IFC of 30 mg/L, AD of 30 mg/L and WT of 313 K.
Effect of Construction Joint on Flexural Behavior of Reinforced Self compacting Concrete Two Way Slabs
Authors: Ismael Murtada A. , Hameed Yahyia M.
Published: August 2020

This paper investigates the influence of construction joints on the behavior of reinforced self-compacting concrete (SCC) slabs in flexure. The experimental scheme involves constructing and testing four slab specimens with dimensions of 450mm×450mm×60mm. One of the specimens is without construction joint as a reference, the second is of vertical construction joint at mid-span of the slab, the third is of horizontal construction joint at mid-depth and the fourth is of construction joint with key-shaped at mid-span. The outcomes of this investigation revealed that the influence of construction joint on the first crack load was more significant than that on the ultimate load. The slab with key-shaped construction joint gave better performance with regard to first crack load and ultimate bearing capacity as compared with the other cases with reduction percentages of 15% and 9.5% respectively as compared with the reference specimen, while the slab with horizontal construction joint in mid-depth represented the less efficiency case with reduction percentages of 40% and 22.8% respectively. Also, the load-deflection relationship becomes stiffer after the first crack load for the slabs with construction joint comparing with the reference specimen.
Low-velocity impact tests on self-compacting concrete prisms
Authors: Abid Sallal R , Al-Gasham Thaar S , Ali Sajjad H , Kadhum Ahmed L
Published: August 2020

Several structural members like columns and walls can be under the effect of accidental strikes from falling objects or collision of moving vehicles. Several researches are available in the literature on impact tests on different types of concrete, while those on Self-Compacting Concrete (SCC) reinforced with steel fiber are very limited. In this research, repeated impact tests were conducted on normal strength and high strength SCC reinforced with micro-steel fibers. Four fiber fractions of 0, 0.5, 0.75 and 1.0% by volume were investigated, while two design strength of 30 and 50 MPa were considered as normal and high strength SCCs. The test procedure was similar to the repeated impact test technique of ACI 544-2R but with a drop height of 100 mm and using prism specimens. The test results showed that micro-steel fiber can increase the impact resistance of SCC significantly. The inclusion of 1.0% fiber led to up to approximately 500% increase in the retained number of impacts at cracking stage, while the percentage increase at failure was much higher which reached approximately 2100%. On the other hand, the adopted high strength SCC could retained only up to approximately 30% higher number of impacts compared to normal strength SCC.
Spatial Analyses of Pavement Condition at Intersection Sites
Authors: AL-Kazaz Ahmed B , Ewadh Hussein A
Published: August 2020

Repeated and periodic assessments of pavement conditions at intersection sites to improve the serviceability of intersection, is an essential component of the transportation system. Further, continuous maintenance of deterioration and defects that appear on the surface layers of pavement at intersection sites according to pavement condition indices (PCI), is a vital process in pavement management. This research aims at conducting spatial analysis for pavement conditions at intersection sites. The application of the developed measure is demonstrated for three signalized intersections in Hilla city, Iraq, by using distress definition. Point density Estimation (PDE) as spatial analyses and interpolation tool (IDW) in ArcGIS software is used to estimate the position intensity. PDE for Pavement condition applications enables the visualization and extraction of distress density in a selected zone or a network of road, which gives the makers of decision an advanced vision to the problem within a location. In this paper, PDE is used to generate potential distress hotspots map based on distress definition data. The result of this research shows the suitability of the heat map for the maintenance entitlement of a particular intersection. It gives a clear indication of the deterioration in the pavement layers depending on the severity of the colours shown in the heat map. For instance, a section of high score of PCI may include a very deteriorating units of low score of PCI due to the presence of many defects. Hence, it can be concluded that, it is doubtful that the PCI section represents the reality of all units. As a sample section (D) of the AL Thawra intersection where there were damaged units, PCI reached 55, 56, 59, while the PCI of section (D) was 74. The developed heat map demonstrates deterioration condition thoroughly for all units and provides advanced vision to pavement condition at the studied sites.
Gravimetric Analysis of Oil pollution of Tigris River
Authors: Humaish Hussein , Hafudh Wissam , Ismaael Baydaa
Published: August 2020

Environmental Pollution has become the first threat to humanity nowadays. Water pollution with petroleum products occupies the largest space because of its impact on the environment and waste of money. Oil is still one of the most important sources of energy currently used in the world. The aim of this research is to monitor and measure the intensity of the oil pollution caused by the oil spill leaks to the Tigris river and to treatment this leakage by oil booms. Six stations for remote sensing were distributed along the Tigris river to record oil concentrations. Each station consists of a sensor and a data reader that receives the digital data from the handsets and stores in the form of tables. Gravimetric analysis has been used to measure oil concentration. An organic solvent, hexane, was used to extract oil from the water. Oil booms have been used to collect spilled oil, preventing oil from spreading and changing flow direction for the purpose of collection. The process of scraping oil above the surface of water was done using oil scrapers.
Building a predictive model to improve the quality of government building construction projects in Iraq using Multi Linear Regression technique
Authors: ALFahham Ahmed F. H. , Alajeeli Hatem K. B.
Published: August 2020

Quality measurement is an important tool for quality improvement. Due to the lack of tools and methods used to measure quality, quality improvement in construction projects is difficult. As a result of the high cost of construction projects for public buildings and the lack of improved tools for measuring quality, there is an urgent need to develop new models. This study aims to provide necessary information for owners, project managers, designers, and contractors to determine the main and secondary factors that have a major impact on improving the quality of construction projects for government buildings and reduce maintenance. This study also contributes to building a predictive model to measure the quality of these projects, and a literature review and interviews were conducted. A personal figure to collect a list of factors affecting the quality of government building projects, and the resulting factors were subject to a survey that was sent to owners, project managers, and engineers working on general construction projects in Iraq. Adoption of the technique of multiple linear regression in the modeling process and determining the most important factors that affect the quality of the project.
Using the uniaxial tension test to satisfy the hyperelastic material simulation in ABAQUS
Authors: Esmail Jihan F. , Mohamedmeki Mohammed Z. , Ajeel Awadh E.
Published: August 2020

Since, hyperelastic materials, such rubber, are widely used in different life fields principally in engineering of elastomeric bearing pads. The present study aims to determine a suitable constitutive model dependent on strain energy potential which can characterize hyperelastic material behavior through uniaxial tension test only. Built-in ABAQUS software constitutive hyperelastic models are used to fit the experimental results of the uniaxial tension test, check the stability and obtain the material coefficients. The used models are that of Mooney-Rivlin, Polynomial, Neo-Hookean, Yeoh and Ogden. The results revealed that Polynomial, Ogden and then Yeoh models are convenient to fit the hyperelastic behavior of the rubber material while Mooney-Rivlin and Neo-Hookean models have a slight ability of fitting limited to the early stage of the linear behavior of the material.
The flow and transport parameter estimation of groundwater in a laboratory-scale sand tank aquifer
Authors: AL-Chlaibawi Shaymaa H , Gzar Hatam A
Published: August 2020

A laboratory study was conducted on groundwater reservoir to characterize the hydrogeological conditions and performance of wells in an unconfined aquifer using laboratory experiments and real-–time groundwater level data. A single-well step-drawdown pumping test was conducted using a two-dimensional sand tank aquifer model, followed by Hunts–Bierschenk’s graphical analyses. The step-drawdown pumping test revealed 25% well losses and 75% aquifer losses, demonstrating high well efficiency, while the well efficiency value of 75% indicated that the well was appropriately designed and developed. The laboratory results suggested that the contact point of the aquifer’s laminar flow and well-face had only slight turbulent flow. A well development factor of 0.46 reflected the effective development of the well. The hydraulic conductivity (K) value was 0.037cm/s. Our approach thus demonstrated the potential of the pumping test of a single-well step-drawdown at the laboratory scale for the estimation of safe and sustained yield from the well for groundwater exploitation within an unconfined aquifer under similar conditions in the future.
Flexural-Creep Stiffness of Asphalt Binders Measured by Simple Developed Apparatus
Authors: Abedali Abdulhaq Hadi , Kareem Yassir Nashaat A. , Jebur Yasir Mohammed , Abed Mohammed A , Almaali Yassir Abo , Fahem Fatimah , Badri Rawand M.
Published: August 2020

As the climate temperature decreases, the flexible pavement will be subjected to high tensile stresses which exceeding to the movement resistance of asphalt binder leading to low temperature cracking. SHRP identified a Bending Beam Rheometer (BBR) for measuring the value of flexural-creep stiffness of asphalt binder at low temperatures which consider this value a good indicator for resistance of low-temperature cracking. This study developed a method for measuring the flexural-creep stiffness of asphalt binder by modification of an apparatus instead of Bending Beam Rheometer due to its expensive cost and unavailable in most research laboratories. A (40-50) penetration grade of asphalt binder used in this study at different test temperatures (-5, 0, 5)°C. The experimental results indicate to the modified apparatus and developed test is suitable for testing an asphalt binder at different temperature and loading time.
Waste time activity determination to improvement process in the Construction environment
Authors: Kh.Shati Hayfaa Abed , Breesam Hatem Khaleefah
Published: August 2020

Waste effects inter-reliant with productivity, the Waste measurement is essential in the management of production systems, because it is an effective way to evaluate their performance. Maine aim for this paper is diagnoses the waste time factors and examined to eliminate them in the implementation ‘the tests assess the performance of the process accomplished by finding the waste time on the two case studies, the observations have been taken in Baghdad using forms developed by researchers specifically designed based on the fundamentals of work-study methods and Work measurement techniques including (Activity sampling observations sheet, the flow process chart, and foremen survey form.) the wasted time causes defined clearly inclusion the performance of general efficiency also determining the Invaluable and unnecessary activities ratio that contribute in the waste of implementation a general regression model had been made for these factors showing the power of their association. The calculations shown the Mismanagement of the site and Choosing an inefficient contractor is most significant. while the conduct of activities the direct work is 56%, and the unnecessary activities by 25.75%, that’s the activity type should target for mitigation to increase the efficiency of the construction process from Wasted Tim reduction.
Environmental and social sustainable operation for parking lots within the Hilla central business district (CBD)
Authors: Medlol Sadiq G. , Alwash Ali A.
Published: August 2020

Central Business District (CBD) is the undisputed center of traffic development resulting from growing industry and economic activity. Attracts people from various parts of the city as well as its area to shop and leisure services. To achieve the objective of this research the Central Commercial Area, Sector 2 in Hilla, was selected to evaluate the sustainability process on the basis of environmental and social indicators for car parks (20 parking lots), as well as identifying the level of service for the pedestrian sidewalks for three roads (Street 60, Street 40 and Bab al-Hussein). The methodology of this research can be summarized by obtaining field data for the volumes of pedestrian traffic using the imaging process, and vehicle parking data (air pollutants from vehicle exhausts, noise level and a number of accidents) through collaboration with relevant government institutions. This work is developing a method for achieving a sustainable composite index for the available information. The indicators are incorporated into environmental, social and economic indicators in a composite sustainable index in a way that overcomes the restrictions of normalization, weight, and aggregation. The results of the composite sustainable transportation index for car parking sustainability range from very low level (2 parking), low level (4 parking), moderate level (12 parking) and high level (2 parking). While the study concluded that the level of service for pedestrian sidewalks is of type (D) for Bab Al-Hussein Street and type (A) for Street 60 and Street 40.
Mechanical Properties of Steel Fiber –Waste Marble Aggregate Concrete
Authors: AL-Baghdadi Waseem H. , Al-Hussaini Osama M. , Al-Assady Fadhl A. , Jabal Qusay A.
Published: August 2020

In this research, the enhancement of compressive, tensile and flexural strength of concrete mixtures was explored using both waste white marble instead of aggregate and steel fibers. White marble was mixed with an ordinary Portland cement replacing the mixture of both coarse and fine aggregate by 10%, 50% and 100% of weight. Besides adding the steel fibres to mixture with a total volume of concrete up to 2%. At the age of 28 days of curing, a significant increase of 24.3%, 34.5% and 38.8% was noticed in compressive, tensile and flexural strengths respectively for the replaced aggregate mixtures. Further improvement was gained by adding the steel fiber.
Experimental and Numerical Comparison of Prestressed Perforated Concrete Rafters of Different Configurations
Authors: Alkhafaji F J , Izzet A F
Published: August 2020

This paper demonstrates an experimental and numerical study aimed to compare the influence of openings of different configurations on the flexural behavior of prestressed concrete rafters. The experimental program consisted of testing six simply supported prestressed concrete rafters; 5 rafters are perforated, and the other one is solid as a reference. All rafters were tested under monotonic midpoint load. The variable which has been investigated in this work was the opening’s configuration (quadrilateral or circular) with the same upper and lower chords depths. The results indicate improvement in the beam flexural behavior using the circular openings compared to the quadrilateral openings, represented by increase the ultimate load capacity and decrease in deflection at the service limit. The experimental results of the tested rafters were confirmed by the non-linear finite element software (ABAQUS13.6.1). Comparisons are offered and the good agreement appears between the experimental results and the predictions of finite element analysis in terms of load-deflection and failure loads relationships.
The Effect of polypropylene fibres on the tensile performance of asphalt mixtures for road pavements
Authors: Shanbara Hayder K. , Musa Sarah S. , Dulaimi Anmar
Published: August 2020

The tensile strength of asphalt mixtures is one of the main parameters of deterioration and failure in flexible pavements. Hence, in this study, the effects of reinforcing asphalt mixtures, using polypropylene fibers, on their engineering performance were experimentally investigated. A set of cylindrical specimens of asphalt mixtures was prepared and subjected to a compressive load at different testing temperatures in terms of evaluation of the indirect tensile stiffness modulus. Similarly, fatigue (four-point bending) and crack propagate (three-point bending) tests were conducted for different asphalt mixtures made with and without polypropylene fibres. The impacts of such fibres on the engineering properties of asphalt mixtures were studied. The laboratory results revealed that the reinforced mixtures with polypropylene fibres had a noticeable influence on the tensile, fatigue and cracking initiation and propagation of these mixtures.
Experimentally Flexural Behaviour Study of Steel Beams with Corrugated Webs
Authors: Al-Kannoon Muslim A. , Suhiel Ibtihal A.
Published: August 2020

The corrugated web girders had a wide applications because of its many favourable properties. Such as there is no need for intermediate stiffeners to avoid local buckling of the web and the reduction in web to produce by this technique. This study is an experimental investigation of flexural behaviour of I-section steel beams with corrugated webs and flat flange. The study involved testing six groups of steel beams. Each group consisted of two identical specimens and the average result was taken for compression. The first two groups consisted of standard and built-up I-section beams which served as a control beams. The other four groups content a corrugated web beams with different corrugation profiles (trapezoidal, rectangular, sinusoidal and zigzag). The experimental results showed that flexural contribution of the web does not exceed 7-11% from the total beam bending capacity for all configurations types. The rectangular corrugated web had the higher bending capacity and mid-span deflection among all the corrugation types.
Inclusive Fitness of Male and Facultatively Social Female Nesting Behavior in the Socially Polymorphic Bee,Ceratina australensis(Hymenoptera: Xylocopinae)
Authors: Oppenheimer Robert L , Rehan Sandra M
Published: August 2020

Male hymenopterans do not typically provide help with nest construction or maintenance. This is thought to be due to the decreased relatedness of males to their siblings compared to sisters, and selection for outbreeding resulting in male dispersal from natal nesting sites. However, some instances of male ‘helping’ behaviors have been observed and can usually be explained by increased access to mating with resident females. Here we report on the first observations of cohabiting males within the nests of reproductive females of the facultatively social small carpenter bee, Ceratina australensis. Social nesting in C. australensis occurs at a consistently low rate across populations. We used microsatellites markers to determine relatedness, combined with 3 yr of nest demographic data collected across three populations, to assess the relative fitness of reproductive, nonreproductive, and male individuals cohabiting in reproductive nests. We found that males were brothers of reproductive females, both remaining in their natal nest. However, there was no evidence that they were mating with their sisters across all nests observed. Males in reproductive nests did not gain any direct or indirect fitness benefits as they did not sire any brood and their presence did not increase brood productivity or survivorship. It is possible that males were waiting to mate with nieces who had not yet emerged. Why males were tolerated remains unknown. Mating biology is an important consideration in social theory which requires additional empirical studies. Future long-term studies are needed to capture unusual social behaviors including male nesting behaviors.
Practice of Academic Surgical Pathology During the COVID-19 Pandemic
Authors: Ahmad Zubair , Rahim Shabina , Ud Din Nasir , Ahmed Arsalan
Published: August 2020

Objectives

To determine the impact of the coronavirus disease 2019 (COVID-19) pandemic on our service, pre-, and postgraduate education and discuss the measures taken to ensure continued provision of quality service as well as education during the mandatory lockdown.

Methods

Measures taken to protect staff from infection and minimize virus transmission within the department as well as measures taken to allow smooth provision of quality service and uninterrupted pre- and postgraduate education were analyzed. Data were collected regarding case volumes (histology, cytology, and frozen sections) and case complexity during the lockdown and analyzed.

Results

Staggered rota was introduced for all staff. Strict social distancing measures were implemented. Staff was extensively counseled regarding the importance of protective measures. Pre- and postgraduate education, which was temporarily suspended, was quickly resumed using online teaching ensuring continuation of academic activities. The volume of cases decreased during the lockdown but complexity increased even more.

Conclusions

Immediate and effective measures were taken to protect staff from infection and ensure smooth provision of quality services. Measures were quickly taken to ensure resumption of pre- and postgraduate academic activities. The volume of cases decreased but complexity increased. There is fear among faculty and staff regarding the future.
Scopy: an integrated negative design python library for desirable HTS/VS database design
Authors: Yang Zi-Yi , Yang Zhi-Jiang , Lu Ai-Ping , Hou Ting-Jun , Cao Dong-Sheng
Published: August 2020

Background

High-throughput screening (HTS) and virtual screening (VS) have been widely used to identify potential hits from large chemical libraries. However, the frequent occurrence of ‘noisy compounds’ in the screened libraries, such as compounds with poor drug-likeness, poor selectivity or potential toxicity, has greatly weakened the enrichment capability of HTS and VS campaigns. Therefore, the development of comprehensive and credible tools to detect noisy compounds from chemical libraries is urgently needed in early stages of drug discovery.

Results

In this study, we developed a freely available integrated python library for negative design, called Scopy, which supports the functions of data preparation, calculation of descriptors, scaffolds and screening filters, and data visualization. The current version of Scopy can calculate 39 basic molecular properties, 3 comprehensive molecular evaluation scores, 2 types of molecular scaffolds, 6 types of substructure descriptors and 2 types of fingerprints. A number of important screening rules are also provided by Scopy, including 15 drug-likeness rules (13 drug-likeness rules and 2 building block rules), 8 frequent hitter rules (four assay interference substructure filters and four promiscuous compound substructure filters), and 11 toxicophore filters (five human-related toxicity substructure filters, three environment-related toxicity substructure filters and three comprehensive toxicity substructure filters). Moreover, this library supports four different visualization functions to help users to gain a better understanding of the screened data, including basic feature radar chart, feature-feature-related scatter diagram, functional group marker gram and cloud gram.

Conclusion

Scopy provides a comprehensive Python package to filter out compounds with undesirable properties or substructures, which will benefit the design of high-quality chemical libraries for drug design and discovery. It is freely available at https://github.com/kotori-y/Scopy.
Vasectomy and prostate cancer risk: a meta-analysis of prospective studies
Authors: Cheng Sheng , Yang Bo , Xu Liwei , Zheng Qiming , Ding Guoqing , Li Gonghui
Published: August 2020

Epidemiological cohort studies investigating the association between vasectomy and prostate cancer risk have yielded inconsistent results. The aim of the present meta-analysis is to update the evidence on the association between vasectomy and prostate cancer. A comprehensively literature search of relevant studies was performed in December 2019 using PubMed. A DerSimonian and Laird random-effects model was used to calculate the summary relative risk (RR) and its 95% confidence interval (CI). A total of 15 eligible cohort studies (16 data sets) with more than four million of participants were eventually included in this meta-analysis. There was a statistically significant higher risk of prostate cancer among men who underwent vasectomy (RR: 1.09, 95% CI: 1.04–1.13) with obvious heterogeneity among included studies (P < 0.001, I2 = 64.2%). Vasectomy was also associated with the risk of advanced prostate cancer (RR: 1.07, 95% CI: 1.02–1.13), which is less likely to be affected from detection bias. In conclusion, findings from this meta-analysis of prospective studies indicate that vasectomy may be positively associated with the risk of prostate cancer. Further large prospective studies with long follow-up are warranted to verify the findings from this meta-analysis. In addition, the potential underlying molecular mechanism needed further exploration with in vitro and animal studies.