bluuebunny/crossref_metadata_2025 huggingface dataset:
Excavation Support and Foundation Ground Improvement Using Jet Grouting Method – A Case Study
Authors: Mustafa bilal A. , Elahi H.R. , Sabermahani M. , Mousavi S.H.
Published: September 2023

One of the soil improvement methods is using soil-cement columns, and one of the most common methods of implementing these columns is the Jet grouting method. In this article, the performance of Jet grouting columns in soil improvement and excavation wall stabilization is investigated in a project located in Chalous, north of Iran, by implementing several experimental soil-cement columns in real scale at depths of 4, 8, and 15 meters and diameter of 80 cm. By comparing the soil settlement before and after the improvement, it was found that the average settlement, which was in the range of 186 mm before the improvement, reached about 68 mm after the improvement using the jet grouting method. It has been observed that the settlement of the foundation has been significantly reduced after improving the ground with soil-cement columns. On the other hand, the results of this study showed that this method has also been very effective in stabilizing the excavation walls. The maximum displacement of the crest of the wall is about 3.4 cm, and the maximum settlement behind the wall is limited to 12 mm.
Using a Laboratory Model Test to Evaluate Collapsibility of Gypseous Soils Improved by Sludge
Authors: Kamil Kamil S. , Abdulkareem Ahmed H. , Mahmood Nabeel S.
Published: September 2023

Collapsibility of gypseous soils may cause excessive settlement and severe damage to engineering structures. Many improvement methods have been employed to reduce the collapsibility of these soils, such as by using physical methods or chemical additives. The collapsibility of the improved gypseous soils has conventionally been evaluated by using the odometer test, which may not accurately replicate the field conditions because of the small size of the test specimens. In this research, a laboratory model test of 600x600x600 mm with a model footing of 100x100mm was developed to measure the collapse characteristics of sandy soil with a gypsum content of 37%. The test was first conducted on specimens in the model at three different relative densities. The test was then performed after compacting the top layer of the test specimens [thickness from 50 to 100 mm] to the maximum dry density, as obtained from the Standard Compaction Test. Water treatment sludge was also used to further improve the top compacted layer. The results indicated that the collapsibility settlement reduction factor was 75% when the top layer of 50 mm thickness was compacted to the maximum dry density. Additionally, when the sludge was used with the top layer, the collapsibility settlement reduction factor was 86%.
Evaluation of Tikrit Dune Sand Soil Enhanced with CKD
Authors: Altameemi Zainab A. , Mohammed Shafiqu Qassun S. , Al-Taie Abbas J.
Published: September 2023

Dune sands occupy large parts of Iraq, posing significant challenges for infrastructure building. Geotechnical research and stabilization for dune soils are necessary to determine the engineering features of these soils as a foundation material in consideration of the global growth in construction activities, especially in Iraq. The compressibility and collapsibility of dune soils are key soil features in the design and construction works, which must be carefully analyzed. In this study, selected geotechnical properties, including compaction, compressibility, and collapsibility characteristics, of compacted dune soil samples from the city of Tikrit were evaluated in the laboratory using a specific range of “cement kiln dust (CKD)” concentrations as a stabilizing agent. The amounts of CKD used in this study were 4, 8, 12, 16, and 20% by dry weight of dune soil. The results showed that adding CKD to Tikrit dune soil improved the compaction properties, decreased the compressibility, and amazingly eliminated the collapsibility. The quality of Tikrit dune soils treated with CKD is very high, and it is recommended for use in the construction of geotechnical engineering works.
Ground Improvement of Dhu Al-Kifil Minaret Using Micropile and Cement Grouting
Authors: Mustafa bilal A. , Sabermahani M. , Elahi H.R. , Mousavi S.H.
Published: September 2023

The Minaret of Dhu Al-Kifil Nabi (PBUH), located in the city of Kifil with a height of about 25 meters, is one of the historical monuments of Iraq. The 4.5 degree deviation of this Minaret has become a challenge for authorities in recent years. Various reasons, such as the old age of the building and manipulation of the soil of the minaret bed, damage the structure and have caused it to deviate from the vertical direction and form cracks at its height. A temporary metal retaining structure is currently constructed on the site to maintain the building in its current state. Still, in order to remove it and repair the body and foundation of the Minaret, the designs have been carried out by Iranian engineering groups. After that, its strengthening operations have also finished. In this article, after the introduction of the project, the analytical and numerical results of the bed improvement plan using the combination of inclined and vertical micropiles are presented. Finally, the reliability of the plan in controlling the heterogeneous settlement of the Minaret is assessed.
Experimental Study for Load-Settlement Behavior of Flat and Shell Footings on Sandy Silt Soil
Authors: Mahmood Alaa Y. , Khalil Amina A.
Published: September 2023

Shell foundations are often used to raise the carrying capacity of a structure on weak soils. In cases where large superstructure loads must be transferred to poorer soils, shell foundations are more cost-effective than ordinary shallow foundations. Advances in the study and design of shell-type foundations have shown their superiority over traditional footings in poorer soils. The current study aims to investigate shell shape’s influence on ultimate load capacity. Seven footing types’ models were created along with an appropriate testing box. The soil needed for the study was from the region north of Mosul city, classified as silt with low plasticity (sandy silt) soil. A laboratory model experimentally determined the ultimate load capacities for inverted and upright conical, inverted and upright pyramid, and hemispherical shell foundations on silty soil. The achieved results were associated with those for conventional flat squares and circles. According to the findings, the “upright conical” shell footing has a load capacity of 12.7 kN, higher than the other foundations, and its efficiency was 51%. When comparing foundations, the “upright pyramidal” shell footing has better settling characteristics and a settlement factor of 0.017. As the shell factor decreases, the shell foundation begins to behave more like a flat foundation, which reduces the maximum load capacity of the shell foundation.
Evaluation on the SPT Based Design Approach for Shallow Foundations
Authors: Fahad Raghad Adel , Shakir Ressol R. , Ali Haneen Mohammed
Published: September 2023

This research evaluated four SPT-based design equations used to estimate the carrying capacity of shallow footing. Using different methods, two plate load tests performed on silty clay and clay soil in Nasiriyah have been used to obtain the ultimate load-carrying capacity. Further, this study aims to utilize the finite element method based on Plaxis 3D foundation software to simulate the behavior of load settlement of the foundation with actual dimensions. It was concluded that the numerical analysis methods showed a good convergence to the actual test results, where the numerical results were 67 and 65 ton/m2for two projects, respectively. The field values were 70 ton/m2for projects with a number of possibilities in determining the failure areas of the soil to give a sufficient picture of the load expectations. The boundary of the influence zone obtained by the finite element method has functioned as an influence zone proposed for a new proposed equation which gave a good convergence with the measured bearing capacity values.
Evaluation of Elasticity Modulus of Clayey Soil from Undrained Shear Strength
Authors: Waheed Mohanned Q. , Asmael Noor M.
Published: September 2023

The modulus of elasticity represents the soil stiffness; it was used to design and analyze the foundation, slope stability, retaining structure, etc. It is one of the main input parameters used in the finite element method for analyzing soil behavior. The scope of this study is to evaluate the correlation between the modulus of elasticity (E) and the cohesion of the soil (cu) for the remolded and undisturbed samples of clayey soil so it can assess the effect of lateral confining pressure on the soil modulus of elasticity. The unconfined test is chosen for remolded soil to identify the stress-strain behavior. After the experimental utilized is done, the test is modeled using the finite element method to study several states of soil. The PLAXIS program is utilized, and the results are compared with the practical results. The mohr-Coulomb model is chosen for this study because it is commonly used. Based on the results throughout this study, it can be concluded the simulation using the Mohr-Coulomb model of PLAXIS software gives good results for representing the unconfined compression test, so that for soft clay, the ratio between modulus of elasticity and cohesion is equal to (Eu = 30 cu) for remolded clay and (Eu = 55 cu) for undisturbed clay. While for stiff clay, it was equal (Eu = 65 cu) for remolded and (Eu = 120 cu) for undisturbed clay. The modulus of elasticity for the undisturbed is higher than for remolded clay, so the difference is almost double in the case of stiff clay. The lateral confining pressure affects the modules of soil; however, for soft clay, the range of soil modulus in the case of the drained test was (5 to 25 MPa), while the range is higher for the undrained case (18 to 54 MPa). Moreover, for stiff clay, the range was equal (11 to 100 MPa) for a drained test and between (18 to 100 MPa) for an undrained case.
Abaqus Simulation of the Fire's Impact on Reinforced Concrete Bubble Deck Slabs
Authors: Al-Ansari Ahmed A. , Kharnoob Majid M. , Kadhim Mustafa A.
Published: September 2023

The use of Bubble Deck in modern prefabricated construction methods has recently become widespread in industrial projects worldwide. In the middle of a typical slab, Bubble Deck places hollow plastic balls that do not improve structural performance but significantly reduce structural weight. This study analyzes the behavior of self-uniting bidirectional concrete slabs with plastic spherical voids under high temperatures and for different periods. Six simply supported bidirectional plates, five of which contained bubbles and one solid, were numerically tested using the finite element method and the commercial ABAQUS software to investigate the behavior of bidirectional plates fired at various temperatures and for various amounts of time. Each slab has the following measurements: (1500*1500*150) mm. These slabs were fired at different temperatures (600 and 800) °C and for different periods (one and two hours). The slabs were classified into four groups depending on the kind of slab (solid or bubble), the degree of burning (600 and 800) °C, and the duration of the burning (one and two hours). The loading strength of concrete was found to be up to 65% less than the maximum capacity of a slab that was bubbled and fired at high temperatures. The length of the firing time also had a significant effect on reducing the strength of the concrete. The longer the firing period, the lower the load resistance of the concrete. The ball would melt and scorch in an intense, protracted fire without noticeable effects. The ability of the steel to maintain adequate strength during a fire, when it will be burned and lose significant strength as the temperature rises, determines the slab’s ability to withstand fire. Bubble deck slabs produce between 17% and 39% stronger thermal resistance than an equivalent solid slab of the same depth, even though they are not intended to provide thermal insulation due to the encapsulation of the air bubbles within the center of the concrete slab.
Structural Behavior of Prestressed RC Dapped Beam with Openings Strengthened Using CFRP Sheets
Authors: Mohammad Abdulkareem Qassim , Abbas Rafaa M.
Published: September 2023

This research examines the strengthening efficiency of prestressed concrete dapped end beam with opening under monotonic point load. The study concerns with the position of the opening relative to the dapped end, the shape of opening, as circle or square, in addition, the effect of CFRP strengthening around the opening. The experimental program consisted of testing nine scaled down prestressed concrete dapped end beam specimens with single opening near the dapped end. Beam specimens consisted of one control beam and the remaining eight beams classified into two groups. The first group contained four unstrengthened specimens, whereas the second group included beams with opening strengthened using CFRP sheets. A full wrapping configuration for the opening region was adopted in this research. The results presented the detrimental influence of the openings on the shear strength of the dapped beam and the additional strength achieved from strengthening. This study concludes that the shear strength of the prestressed dapped beam decreased by the presence of openings in the web with maximum reduction about 20% when the opening was located close the dapped end. Based on the test results, the strengthened beams recovered significant part of their original load carrying capacity. Generally, prestressed dapped beams regain a maximum of 92% of their strength when openings with different configurations and locations were strengthened with full CFRP wrap.
Experimental Study on the Performance of Concrete Beams Including Holes Reinforced with Glass Fiber Polymer
Authors: Ali Hasan Hussein , Said Abdulmuttailb I.
Published: September 2023

This paper carried out An examination of the performance characteristics of concrete beams including openings that were reinforced with Glass Fiber Reinforced Polymer (GFRP) bars. This investigation studied five reinforced concrete (RC) beams with both longitudinal and transverse GFRP reinforcement with openings in two directions (horizontal and vertical) were studied. Both the orientation of the openings and the number of openings were considered to be the main parameters in this research. These holes are located in the beams' flexural region. The results demonstrate that relative to the reference beam, the vertical openings significantly reduced the maximum load of the tested beams by 27.8% and increased the mid-span displacement by 39% relative to the control beam. In addition, the research results demonstrated that the strength of the beam was scaled down if one equivalent opening was used to substitute for two adjacent openings.
Behavior of Damaged Continuous Reinforced Concrete Beams Repaired by CFRP Sheets
Authors: Alkinani Alaa Y. , Kamonna Hayder H.
Published: September 2023

Despite the widespread use of RC continuous beams, the performance of these beams, when repaired via Fiber Reinforced Polymer (FRP) composite material, has received less attention. Furthermore, several features of the flexural aspect of repaired RC continuous beams still demand experimental and analytical evaluation. However, many anchoring methods have been developed to delay premature failure in the RC beams, which are strengthened with FRP composite materials. The plan of this experimental study consists of eight continuous beams cast with dimensions (150*250*2800) mm considering the length of the clear span is 1300mm. Except for one, all specimens were attached via Carbon FRP sheets about 70% of the span length in negative and positive moment zones beyond a predetermined damage level. Moreover, this study suggested modifying the end-anchor technique and adding CFRP layers with (45, 65, and 95) % as damage ratios. According to the results, the optimal percentage of restored ultimate capacity was 108.8% with peeling-off concrete cover failure mode, which was obtained from using an end-anchor and two layers of the sheet. Also, increasing the damage ratio leads to a decline in toughness and ductility values. In addition, it is possible to repair the structure with a 95% damage ratio rather than remove it.
Structural Behavior of Short Thin-Walled Steel Columns Filled with High Strength Concrete Made of Recycled Aggregate
Authors: Samir Haitham A. , Almamoori Ali H. N.
Published: September 2023

This paper introduces an experimental work to study the behavior of 12 recycled aggregate concrete-filled steel tubular (RACFST) short columns with high-strength concrete grade subjected to axial compression loading. These columns formed from six different cross-sections involving triangle, elliptical, and hexagon, whereas the other three sections included traditional forms for control purposes, involving square, rectangular, and circular. All RACFST columns used are made of mild steel plates. These columns were divided into two groups. The steel tube thickness was the only parameter modified to study its effect properly. In addition, the study included the search for the best effective section concerning the properties of stability and confinement, so these columns were designed so that the cross-sectional areas of steel tubes were approximately equal. Also, composite action and level of ductility for these columns were studied. The ultimate failure axial load, the reduction in the axial column length, the failure pattern of cross-section shape, and lateral displacement were recorded during the test. Regarding the two groups of columns with (1 and 2) mm thick steel plates, testing data obtained from RACFST columns with elliptical and circular cross-sections respectively showed better stability and confinement of concrete and the ability to withstand a higher ultimate failure stress. Moreover, columns with polygonal sections showed when the number of ribs for the steel plates of the model or increased the angle between the two sides is (90°) or more, column cross-sections can achieve more stability and confinement, respectively. In general , increasing the thickness of the steel tubes increases. Finally, for all columns, the higher values of the concrete contribution ratio (C.C.R) led to an increase in the strength index (S.I.) values. An increase in values of final failure stresses accompanied this increase.
Performance of Reinforced Concrete Gable Beam with Quadrilateral Openings of Different Side Inclinations
Authors: Mohammed Mohammed H. , Izzet Amer F.
Published: September 2023

The existence of openings in a gable beam would have numerous advantages, the most important of which would be a reduction in the overall weight. These advantages include geometric flexibility, ease of handling when erected, and more. This study aims to investigate the flexural behavior of reinforced concrete gable beams with quadrilateral openings of different side inclinations; this goal has been specified with beam stiffness, the maximum load-carrying capacity, and strains of the beams. Beams are identical in their dimensions and reinforcement. The experimental program involved casting and testing four simply supported beams: a solid beam (reference beam) and others with quadrilateral openings. They were 3000mm long, 100mm wide, and 400 mm deep in the middle, tapering to 250 mm on both ends, concentrically loaded. The results demonstrate the load-carrying capacity is reduced by 6.1–12.9%, and the mid-span deflection is increased by 13–52% when openings exist compared to the solid gable beam. Enhancement represented by increases in strength and decreases in deflection was observed when the inclination of the quadrilateral side opening decreased from 90 to 60 and then 45o, respectively. In contrast, the total opening area was maintained. The creation of openings in concrete gable beams can reduce their weight by about 12.5%.
Utilizing CFRP Sheet for Strengthening Extended Concrete Beams
Authors: Mhawesh Zaid A. N. , Sadjad A.H. , Alyhya Wajde S. S.
Published: September 2023

This research investigates the behavior of extended reinforced concrete beams that have been enhanced using CFRP at the extension points. Five reinforced concrete beams with measurements of 2500 mm in length, 150mm in width, and 260mm in height were built and extended in different types. The studied cases included varied CFRP strengthening schemes for the splice joints. The findings conclude that the inclusion of horizontal stirrups on the complete top of the beam produced comparable results to those of the reference beam. Additionally, the spliced beams glued at their lateral faces and strengthened by vertical CFRP laminates provided a marginal increase in their ultimate loads. The results also showed that the strengthening with carbon fibers exhibited lower crack width than the reference beam in general.
Performance of Reinforced Subbase Materials by Geogrid as Abase Layer Under Weak Subgrade
Authors: Banyhussan Qais S. , hassan Hanan A. , Kadhum Ali J.
Published: September 2023

The current study examines how an unpaved road behaves when it is installed on top of a soft clay layer that's been strengthened at the subgrade/subbase interface with a single layer of geogrid type SS2 is used to reinforce a laboratory model, and cycling load is used to apply repeated loads to the model. Subbases with and without reinforcement over soft subgrade were built in a sizable test box. (1000 mm×1000 mm×1000 mm). The test results show that using a geogrid reinforcement layer enhances the number of cycles and stress distribution while decreasing displacement on the soft subgrade surface on reinforced models compared to similar unreinforced ones for the same rutting value (85 mm). The rate of increase in failure time is about (6.12, 3.7, and 1.7) for 150, 230, and 300 mm thickness, respectively. The rate of redaction in vertical stress is about (18, 12.5, and 7.1) % for 150 mm, 230 mm, and 300 mm thickness, respectively.
Prediction Models for Modified Pavement Mixtures by Reclaimed Asphalt in Terms of Durability Indicators
Authors: Al Helo Karim H. Ibrahim , Qasim Zaynab I. , Kadhim Zahraa A.
Published: September 2023

The asphaltic pavement is often subjected to various types of distress during the service life caused by excessive load, construction practices, deficient materials, and environmental conditions. A lot of pavements may occur due to moisture damage because of the presence of water on the pavement's surface, which affects the pavement's service life. It needs periodic maintenance, which requires materials and money. So many countries take the economic side by reusing old, damaged pavement and mixed with new materials in addition to its sustainable benefits, the old material called reclaimed asphalt pavement (RAP). This study examines the effect of adding RAP on durability indicators, including tensile strength ratio, retained Marshall Stability, and durability Index, in addition to prediction statistical models for reclaimed asphalt pavement mixtures in terms of durability indicators. To achieve the goals of this study, the asphalt mixtures are designed according to the superpave system; the samples are compacted by a superpave gyratory compactor with a diameter of 100 mm and prepared with (6%, 13%, 19%, and 25%) RAP content with three conditioning periods of (1, 3, and 7) days and two aging periods (short term aging for loose mixture at 135˚C for 4 hours long term aging for 120 hours at 85˚C), and two testing temperature of 25˚C and 60˚C. The results indicated that stability increased as the RAP content increased compared to the control mix, and indirect tensile strength increased with RAP addition for both aging periods. Also, results illustrated that the tensile strength ratio for specimens tested at 25˚C is higher than that tested at 60˚C temperature.
Enhancement of Physical Properties of Asphalt Binder by Using Silica Powder
Authors: Rasheed Sozan S. , Joni Hasan H. , Al-Rubaee Rasha H.
Published: September 2023

One of the primary requirements for a successful pavement system can be regarded as the caliber of the road pavement. Therefore, various measures have been taken, such as improving pavement quality and structure design methods, to reduce the issues of fatigue cracks and rutting of roads. Since a few years ago, engineers have paid more attention to modifying and improving the performance of asphalt by adding various additives to improve the environment and lower the price of modified pavement mixture. Evaluation of employing modified asphalt cement at various percentages of particle size of silica powder is the main goal of this study. Three percentages of Particle Size of Silica Powder Nano silica and micro silica with 2, 4, and 6% of the weight of asphalt as a modifier for asphalt and their effect on the performance of asphalt mixtures at high temperatures. It was discovered that adding silica powder to asphalt cement would increase the softening point and viscosity and decrease ductility and penetration. Experimental results indicated that the Silica Powder positively contributed to the performance properties of asphalt.
Evaluation of Bonding Interior Layer Failure Strength Modes in the Composite Pavement
Authors: Falih Teeba , Abed Alaa H.
Published: September 2023

A tack coat is a minimal coating of asphalt cement, cut-back asphalt, or asphalt emulsion to an existing pavement surface between layers to guarantee proper bonding between the two layers and longitudinal and transverse Joints. Numerous researchers have assessed interlayer adhesion employing failure-mode behavior tests, such as pull-off, direct shear, and torsion testing. This study aims to quantify the best tensile resistance obtained using PG (76-10) modified asphalt cement with polymer 4.5%, Sikadur®-31 CF (S.E) usage at elevated temperatures between +25 °C and +45 °C, an epoxy-resin-based adhesive, and repair mortar with specific fillers. And Nitomortar TC2000 epoxy (F.E) resin-based sealing compound from Fosrok Company. All are applied on concrete surfaces at a rate of 0.5 kg/m2 except for Nitomortar, which depends on layer thickness ranges between (1-2.5) mm instead of the application rate. The Proceq DYNA Z16 pull–off tester is used to measure the tensile strength at a rate of 2lb/s. It is found that the average tensile strength of the tack coat materials is (0.607, 1.481, 2.622) MPa, respectively. It concluded that (F.E) epoxy has the maximum tensile strength. Also, adding polymer to asphalt increased adhesiveness. Failure strength modes of interior bonding varied between cohesive failure adhesive, adhesive failure, and cohesive failure in the concrete substrate.
Experimental Study of the Effect of Crumb Rubber on Properties of Asphalt Mix by Wet Process
Authors: Al-Soudany Kawther Y. H. , Mohammed Humam H. , Hussein Luay Y. , Qasim Zaynab I.
Published: September 2023

The increase in the number of vehicles during the past twenty years has dramatically increased the traffic density and axial loading. In addition to the construction failures and lack of periodic maintenance, rapid deterioration of the road condition happens. So, it was necessary to find solutions to these problems that have been growing for years. One of these solutions is to improve the asphalt mixture to resist excessive loads and weather fluctuations. This research aims to investigate the addition of crumb rubber derived from recycled tires; to the asphalt mixture for improving performance characteristics and to compare the improved and unimproved samples. It is worth mentioning that crumb rubber addition to the asphalt mixture is considered one of the smart solutions for sustainability that the world is heading towards today, considering that the crumb rubber comes from waste tires, which is difficult to eliminate and pollute the environment. Four different proportions of crumb rubber have been added in this research (6, 9, 12, and 15%); by weight of bitumen to (60-70) asphalt binder, with a particle size passing from sieve no.50 (0.3 mm). The aggregate gradation is designed according to the Marshall method with a (12.5 mm NMAS) wearing course to obtain the optimum asphalt content and to prepare laboratory samples to perform various laboratory tests. Marshall Stability and flow, indirect tensile strength (ITS), moisture susceptibility, and permanent deformation of asphaltic mixes with different contents of crumb rubber were investigated. The results of the tested samples were compared with the original samples. It is shown that the asphaltic mixes performance has been improved when adding a certain amount of crumb rubber. Marshall Stability is increased by 29.2% when adding 9% CR by the weight of bitumen. However, the addition of crumb rubber can increase the stiffness of the asphalt mixture resulting in a more rigid pavement structure that is less prone to moisture damage and rutting under traffic load.
Selected Indicators of Al-Najaf Road Network: Public Transportation Noise and Pollution
Authors: Abdullah Naseer A. , Khalaf Dhuha K. , Al-Jameel Hamid A. , Ali Mohammed J.
Published: September 2023

It is urgently necessary to improve the state of transportation and related infrastructure, especially given that the most important indicators of urban development gauge a city's progress. One of the most influential of these indicators is what is known as "smart transport, " which refers to transportation that utilizes modern communication and information technology technologies to address various challenges in various transportation sectors. The holy city of Najaf smart transportation strategy seeks to reduce dangerous levels of traffic-related noise and air pollution while enhancing various aspects of mobility and traffic flow indicators. This study aims to evaluate the performance of the existing traffic network and public transport in Najaf City and its interference with noise and air pollution at selected points for data gathering by using field measurements using cameras, noise meters, and pollution measurement devices. The study states that the public transport sector in Al-Najaf city is significantly poor as private cars are dominant by about 65% of traffic mix with values of pollution and noise above the standards. One of the most effective solutions to traffic problems is the implementation of intelligent transportation systems. Part of these strategies is establishing a tram network and raising road classes’ strategies by proposing some geometric design editing, U-turns reducing, and raised ramps additions.
The Impact of Financial Crises on The Parties Involved in the Construction Project
Authors: Mahdi Zainab A. , Muhsin Ibrahim F.
Published: September 2023

Iraq has witnessed a number of crises that had an impact on multiple industries, including the construction industry particularly. In 2014, Iraq was subjected to terrorist acts in several provinces, which led to insecurity and a very large financial crisis that affected all provinces, This was followed by the financial crisis that occurred due to the drop in oil prices and because oil was the main and exclusive source of income for the Iraqi economy, this resulted in a severe economic collapse. This study examines the financial crisis's detrimental effects on the construction industry. The research has divided the crisis in finance into two types: the external crisis, which has occurred as a result of external influences such as the decline in oil prices globally, which has been reflected in the budget of the Iraqi government, and the second type is the internal crisis, which has occurred as a result of bankruptcy or the bankruptcy of any of the parties involved in the constructing industry. The open questionnaire represents the practical side, which was completed by conducting personal interviews with construction and project implementation experts and financial and economic experts to discuss how to deal with the crisis's effects and address them. The researcher concluded that the factors that have a high degree of influence on the occurrence of crises are arranged according to relative importance from highest to lowest, as follows: (changes in oil prices, changes in currency exchange rates, the bankruptcy of banks, force majeure, high prices, and the unemployment rate). The (post-crisis stage) is the highest among the stages, with the highest percentage when it comes to the stage at which the financial crisis impacting construction projects could be addressed.
Gastrointestinal Dysfunction in Multiple Sclerosis and Related Conditions
Authors: Sakakibara Ryuji
Published: September 2023

Nervous system disorders may be accompanied by gastrointestinal (GI) dysfunction. Brain lesions may be responsible for GI problems such as decreased peristalsis (e.g., lesions in the basal ganglia, pontine defecation center/Barrington's nucleus), decreased abdominal strain (e.g., lesions in the parabrachial nucleus), hiccupping and vomiting (e.g., lesions in the area postrema), and appetite loss (e.g., lesions in the hypothalamus). Decreased peristalsis also may be caused by lesions of the spinal long tracts or the intermediolateral nucleus projecting to the myenteric plexus. This review addresses GI dysfunction caused by multiple sclerosis, neuromyelitis optica spectrum disorder, and myelin oligodendrocyte glycoprotein-associated disorder. Neuro-associated GI dysfunction may develop concurrently with brain or spinal cord dysfunction or may predate it. Collaboration between gastroenterologists and neurologists is highly desirable when caring for patients with GI dysfunction related to nervous system disorders, particularly since patients with these symptoms may visit a gastroenterologist prior to the establishment of a neurological diagnosis.
Infant Rudimentary Meningocele with Tethering of the Cervical Cord: A Case Report
Authors: Shanahan Regan M. , Hudson Joseph S. , Huq Sakibul , Legarreta Andrew , Fields Daryl P. , Phillips H. Westley , Kellogg Robert G.
Published: September 2023

Rudimentary meningoceles of the spine with dural extension are very rare and warrant surgical excision to prevent infection and long-term neurological deficits in pediatric patients. We present the case of a 5-month-old infant with a tethered spinal cord secondary to a rudimentary meningocele. The patient presented shortly after birth with a midline cervical dimple that was evaluated for a suspected dermal sinus tract. Magnetic resonance imaging scan of the spine showed a sinus tract with intradural extension to C2-3 and external opening at the level of spinous process C5. En bloc surgical excision and spinal cord release were successfully performed. Histological analysis of the specimen confirmed the presence of two blunt sinus tracts and staining was consistent with a rudimentary meningocele. Intradural rudimentary meningoceles in infants can successfully be managed with surgical intervention. Surgery is indicated to prevent future motor complications from spinal cord tethering and neoplastic growth from the rudimentary meningocele.
Physics-informed Bayesian inference of external potentials in classical density-functional theory
Authors: Malpica-Morales Antonio , Yatsyshin Peter , Durán-Olivencia Miguel A. , Kalliadasis Serafim
Published: September 2023

The swift progression and expansion of machine learning (ML) have not gone unnoticed within the realm of statistical mechanics. In particular, ML techniques have attracted attention by the classical density-functional theory (DFT) community, as they enable automatic discovery of free-energy functionals to determine the equilibrium-density profile of a many-particle system. Within classical DFT, the external potential accounts for the interaction of the many-particle system with an external field, thus, affecting the density distribution. In this context, we introduce a statistical-learning framework to infer the external potential exerted on a classical many-particle system. We combine a Bayesian inference approach with the classical DFT apparatus to reconstruct the external potential, yielding a probabilistic description of the external-potential functional form with inherent uncertainty quantification. Our framework is exemplified with a grand-canonical one-dimensional classical particle ensemble with excluded volume interactions in a confined geometry. The required training dataset is generated using a Monte Carlo (MC) simulation where the external potential is applied to the grand-canonical ensemble. The resulting particle coordinates from the MC simulation are fed into the learning framework to uncover the external potential. This eventually allows us to characterize the equilibrium density profile of the system by using the tools of DFT. Our approach benchmarks the inferred density against the exact one calculated through the DFT formulation with the true external potential. The proposed Bayesian procedure accurately infers the external potential and the density profile. We also highlight the external-potential uncertainty quantification conditioned on the amount of available simulated data. The seemingly simple case study introduced in this work might serve as a prototype for studying a wide variety of applications, including adsorption, wetting, and capillarity, to name a few.
Generating a tunable narrow electron beam comb via laser-driven plasma grating
Authors: Yang Hetian , Wang Jingwei , Luan Shixia , Feng Ke , Wang Wentao , Li Ruxin
Published: September 2023

We propose a novel approach for generating a high-density, spatially periodic narrow electron beam comb (EBC) from a plasma grating induced by the interference of two intense laser pulses in subcritical-density plasma. We employ particle-in-cell (PIC) simulations to investigate the effects of cross-propagating laser pulses with specific angles overlapping in a subcritical plasma. This overlap results in the formation of a transverse standing wave, leading to a spatially periodic high-density modulation known as a plasma grating. The electron density peak within the grating can reach several times the background plasma density. The charge imbalance between electrons and ions in the electron density peaks causes mutual repulsion among the electrons, resulting in Coulomb expansion and acceleration of the electrons. As a result, some electrons expand into vacuum, forming a periodic narrow EBC with an individual beam width in the nanoscale range. To further explore the formation of the nanoscale EBC, we conduct additional PIC simulations to study the dependence on various laser parameters. Overall, our proposed method offers a promising and controlled approach to generate tunable narrow EBCs with high density.
Characterization of hot electrons generated by laser–plasma interaction at shock ignition intensities
Authors: Filippov E. D. , Khan M. , Tentori A. , Gajdos P. , Martynenko A. S. , Dudzak R. , Koester P. , Zeraouli G. , Mancelli D. , Baffigi F. , Gizzi L. A. , Pikuz S. A. , Nicolaï Ph.D. , Woolsey N. C. , Fedosejevs R. , Krus M. , Juha L. , Batani D. , Renner O. , Cristoforetti G.
Published: September 2023

In an experiment carried out at the Prague Asterix Laser System at laser intensities relevant to shock ignition conditions (I > 1016 W/cm2), the heating and transport of hot electrons were studied by using several complementary diagnostics, i.e., Kα time-resolved imaging, hard x-ray filtering (a bremsstrahlung cannon), and electron spectroscopy. Ablators with differing composition from low Z (parylene N) to high Z (nickel) were used in multilayer planar targets to produce plasmas with different coronal temperature and collisionality and modify the conditions of hot-electron generation. The variety of available diagnostics allowed full characterization of the population of hot electrons, retrieving their conversion efficiency, time generation and duration, temperature, and angular divergence. The obtained results are shown to be consistent with those from detailed simulations and similar inertial confinement fusion experiments. Based on the measured data, the advantages, reliability, and complementarity of the experimental diagnostics are discussed.
Enhanced linearity through high-order antisymmetric vibration for MEMS DC power sensor
Authors: Zou Xuecui , Jaber Nizar , Bukhamsin Abdullah , Yaqoob Usman , Salama Khaled Nabil , Fariborzi Hossein
Published: September 2023

We present an electric power meter that capitalizes on the interaction of electrothermal strain and mechanical vibration in a micro-electro-mechanical systems (MEMS) beam undergoing the antisymmetric mode of vibration. This is achieved by using a resonant bridge driven with an electrothermal modulation technique. The change in electrical power is monitored through the alteration in the mechanical stiffness of the structure, which is tracked electrostatically. The observed deflection profile of the beam under the influence of electrothermal effects shows that the deflection geometry due to buckling exhibits similar trends as the first symmetric vibrational mode, in contrast to the antisymmetric mode. Therefore, we compare two distinct vibrational modes, converting the compressive thermal stress generated by the input electrical power via Joule heating into a shift in the resonance frequency. By employing antisymmetric vibrational mode, the output of our device is consistently monotonic to the input electrical power, even when the microbeam is experiencing buckling deflections. In addition, the sensing operation based on antisymmetric modes yields only a 1.5% nonlinear error in the response curve, which is ten times lower than that of symmetric modes. The observed deformation shape of the resonator agrees with the results obtained from multi-physics finite simulations. Finally, this approach has the potential to be extended to other frequency-shift-based sensors, allowing for higher linearity.
Aerodynamic-whistles-based ultrasonic tone generators for bat deterrence
Authors: Zeng Zhangming , Sharma Anupam
Published: September 2023

Novel ultrasonic bat deterrents based on aerodynamic whistles are proposed and investigated experimentally and numerically for their ability to generate ultrasound. The baseline deterrent, a single-whistle design inspired by Beeken [“Fluid ultrasonic generator,” U.S. patent 3,432,804 (1969)], is examined first. It consists of two resonating cavities/chambers. The whistle is “powered” by a regulated high-pressure air supply, and the performance of the whistle is examined for a range of supply pressures. Far-field acoustic measurements in the 20 Hz–50 kHz frequency range are made in an anechoic chamber. The noise measurements are supplemented with two- and three-dimensional unsteady Reynolds-averaged Navier–Stokes (uRANS) simulations to investigate the mechanisms of ultrasound generation. The Ffowcs Williams–Hawkings acoustic analogy is used with the three-dimensional uRANS results to predict the far-field radiation. The far-field acoustic predictions are in good agreement with the measurements in the anechoic chamber. The peak frequency (fundamental) of the radiated ultrasound of the baseline deterrent is approximately 23 kHz. Harmonics and a sub-harmonic of the fundamental tone are also observed. The numerical simulations show that the two resonating chambers of the baseline deterrent operate out-of-phase and Helmholtz resonance determines the whistling frequency over the range of supply air pressure considered. A six-whistle deterrent targeting a broad spectral coverage in the 20–50 kHz frequency range is designed, fabricated, and tested in the anechoic chamber. Each whistle in the deterrent is obtained by geometrically scaling the baseline whistle. Measurements show that the six-whistle ultrasound deterrent generates ultrasound with six dominant peaks in the designed frequency range when the supply air pressure exceeds 5 psig. The proposed ultrasound devices can be used for a variety of purposes including bat deterrence at wind turbines.
Effects of turbulent inflow time scales on wind turbine wake behavior and recovery
Authors: Hodgson Emily L. , Madsen Mads H. Aa. , Andersen Søren J.
Published: September 2023

Wind turbines experience a range of turbulent time and length scales related to the atmospheric boundary layer, wakes of upstream turbines, and wind farm effects. This work aims to investigate the impact of turbulent scales on wake behavior and recovery, in isolation from overall turbulence intensity, shear, or buoyancy. Large eddy simulations of a single turbine are conducted using idealized single time scale inflows and full spectra turbulent inflows, varying the predominant time scale in the equivalent Strouhal number range of St=0.04–0.5, while maintaining the same turbulence intensity and flow structures. Under idealized inflows, shorter inflow time scales result in a faster breakdown of tip vortices, while longer scales induce greater wake meandering. For full spectra turbulent inflows, shorter integral time scales result in a shorter near-wake region and enhanced wake recovery, while wake meandering occurs to a similar extent when adjusted for the near-wake breakdown location. A wake-generated turbulence region in the range of St=0.3–0.7 is identified in the streamwise velocity spectra, and inflows that contain more turbulent kinetic energy in this range show a faster redistribution from long inflow scales to smaller wake-generated turbulence and enhanced wake recovery. The improved wake recovery for the shortest integral time scale results in a 9% increase in mean rotor-averaged velocity and 35% increase in power at 12R downstream, compared to the longest integral time scale. Overall, it is shown that inflow turbulent scales have a significant impact on wake recovery, particularly through their impact on the near-wake breakdown.
Simulations of spin/polarization-resolved laser–plasma interactions in the nonlinear QED regime
Authors: Wan Feng , Lv Chong , Xue Kun , Dou Zhen-Ke , Zhao Qian , Ababekri Mamutjan , Wei Wen-Qing , Li Zhong-Peng , Zhao Yong-Tao , Li Jian-Xing
Published: September 2023

Strong-field quantum electrodynamics (SF-QED) plays a crucial role in ultraintense laser–matter interactions and demands sophisticated techniques to understand the related physics with new degrees of freedom, including spin angular momentum. To investigate the impact of SF-QED processes, we have introduced spin/polarization-resolved nonlinear Compton scattering, nonlinear Breit–Wheeler, and vacuum birefringence processes into our particle-in-cell (PIC) code. In this article, we provide details of the implementation of these SF-QED modules and share known results that demonstrate exact agreement with existing single-particle codes. By coupling normal PIC simulations with spin/polarization-resolved SF-QED processes, we create a new theoretical platform to study strong-field physics in currently running or planned petawatt or multi-petawatt laser facilities.
Tuning of electrical properties of CVD grown graphene by surface doping with organic molecules
Authors: Singh Anand Kumar , Andleeb Shaista , Singh Arun Kumar
Published: September 2023

Tailoring the charge carriers of two-dimensional (2D) materials is essential for high performance optoelectronic devices. The surface transfer doping by adsorption of molecules on 2D crystals is an attractive technique to tune the properties. Here, we study the change in the electronic transport properties of monolayer graphene (MLG) by surface doping with two different types of molecules. An effect of methyl isobutyl ketone (MIBK) and chlorobenzene molecular doping on the carrier concentration and electrical conductivity of chemical vapor deposition(CVD)-grown MLG was carried out by Raman spectroscopy and electrical transport measurement. The shifting of Raman peaks toward higher wave number and shifting of Dirac points toward positive gate voltage confirmed that the surface doping of graphene with MIBK and chlorobenzene molecules induced holes doping effect. The molecular doping approach significantly improved the carrier concentration of CVD grown MLG, which is a promising result. Our study will be useful for understanding as well as improvement of graphene based electronic device research.