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Assessment of the Cost and Time Impact of Variation Orders on Construction Projects in Sulaimani Governorate
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Variation orders are an on-going phenomenon in construction and industry projects worldwide, particularly in the province of Sulaimani, where the project's damage from cost and schedule overrun because of variation orders. However, the effect on project costs and time overrun of variation order has yet to be identified. This study evaluates the impact of variation orders on the cost and time off in the Sulaimani governorate. Two hundred twenty-eight projects from various construction sectors built between 2007-2012 were adopted to calculate the contract cost and schedule overruns due to variation orders. Data analysis was applied in the study were descriptive statistics. One-way ANOVA was also applied to determine whether the overrun of project cost and schedule significantly varied depending on project type, size, duration, location, and awarded years. The findings indicated that cost overruns are very common due to variation orders. 95.6% of the projects were studied being impacted, and overrun in project cost are also huge, with 16%. Time also overruns more common than cost overruns due to the variation orders. 98.7% of the projects were studied in Sulaimani were affected by time overrun with an average of 46.3% of initial duration observed. Findings also indicated that two out of five parameters measured in the analysis had a significant correlation with project cost overruns. Three out of five considered variables correlated with construction time overruns. 

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Publication Date
Wed Nov 30 2022
Journal Name
Desalination And Water Treatment
Removal of amoxicillin from wastewater by adsorption onto activated carbon prepared from sunflower seed hulls
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In this study, the potential of adsorption of amoxicillin antibiotic (AMOX) from aqueous solutions using prepared activated carbon (AC) was studied. The used AC was prepared from an inexpensive and available precursor (sunflower seed hulls (SSH)) and activated by potassium hydroxide (KOH). The prepared AC was examined for its ability to remove AMOX from aqueous contaminated solutions and characterized with the aid of N2 -adsorption/desorption isotherm Brunauer–Emmett– Teller, scanning electron microscopy, energy-dispersive X-ray spectroscopy and Fourier-transform infrared. Zeta potential of the prepared activated carbon from sunflower seed hulls (SSHAC) were studied in relation to AMOX adsorption. The physical and chemical propert

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Publication Date
Thu Jan 23 2020
Journal Name
Acoustics Australia
Absorption Coefficient of a Double-Layer Inhomogeneous Micro-perforated Panel Backed with Multiple Cavity Depths
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Double-layer micro-perforated panels (MPPs) have been studied extensively as sound absorption systems to increase the absorption performance of single-layer MPPs. However, existing proposed models indicate that there is still room for improvement regarding the frequency bands of absorption for the double-layer MPP. This study presents a double-layer MPP formed with two single MPPs with inhomogeneous perforation backed by multiple cavities of varying depths. The theoretical formulation is developed using the electrical equivalent circuit method to calculate the absorption coefficient under a normal incident sound. The simulation results show that the proposed model can produce absorption coefficient with wider absorption bandwidth compared w

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Publication Date
Thu Oct 01 2020
Journal Name
Alexandria Engineering Journal
Biodegradation of reactive dyes by some bacteria using response surface methodology as an optimization technique
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Water pollution as a result of contamination with dye-contaminating effluents is a severe issue for water reservoirs, which instigated the study of biodegradation of Reactive Red 195 and Reactive Blue dyes by E. coli and Bacillus sp. The effects of occupation time, solution pH, initial dyes concentrations, biomass loading, and temperature were investigated via batch-system experiments by using the Design of Experiment (DOE) for 2 levels and 5 factors response surface methodology (RSM). The operational conditions used for these factors were optimized using quadratic techniques by reducing the number of experiments. The results revealed that the two types of bacteria had a powerful effect on biodegradable dyes. The regression analysis reveale

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Publication Date
Mon May 01 2023
Journal Name
Ain Shams Engineering Journal
Neural network modeling of rutting performance for sustainable asphalt mixtures modified by industrial waste alumina
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Publication Date
Tue Apr 02 2024
Journal Name
Journal Of Engineering
Revolutionizing Depth Sensing: A Review Study of Apple LiDAR Sensor for as-built Scanning Applications
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Incorporating the LiDAR sensor in the most recent Apple devices represents a substantial development in 3D mapping technology. Meanwhile, Apple's Lidar is still a new sensor. Therefore, this article reviews the potential uses of the Apple Lidar sensor in various fields, including engineering and construction, focusing on indoor and outdoor as-built 3D mapping and cultural heritage conservation. The affordable cost and shorter observation times compared to traditional surveying and other remote sensing techniques make the Apple Lidar an attractive choice among scholars and professionals. This article highlights the need for continued research on the Apple LiDAR sensor technology while discussing its specifications and limitations. A

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Publication Date
Mon Oct 07 2024
Journal Name
Semiconductor Science And Technology
A facile method of deriving solar selective nickel-cobalt oxide thin films via spraying process
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Abstract<p>The present study focuses on synthesizing solar selective absorber thin films, combining nanostructured, binary transition metal spinel features and a composite oxide of Co and Ni. Single-layered designs of crystalline spinel-type oxides using a facile, easy and relatively cost-effective wet chemical spray pyrolysis method were prepared with a crystalline structure of M<sub>x</sub>Co<sub>3−x</sub>O<sub>4</sub>. The role of the annealing temperature on the solar selective performance of nickel-cobalt oxide thin films (∼725 ± 20 nm thick) was investigated. XRD analysis confirmed the formation of high crystalline quality thin films with a crystallite si</p> ... Show More
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Publication Date
Tue Dec 31 2024
Journal Name
International Review On Modelling And Simulations (iremos)
Vibration Analysis of Laminated Shallow Shells Under Thermal Loading Using Higher Order Shear Deformation Theory
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Publication Date
Tue Jun 01 2021
Journal Name
Journal Of The College Of Languages (jcl)
Metaphor in Political Discourse Press Articles By Louis Bassets As A Model: La metáfora en el discurso político. Los artículos de Lluís Bassets como ejemplo
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       The present paper focuses on studying a rhetorical form often used in Spanish linguistic discourse .It also examines the study two sides (theoretical and practical), the concept of metaphor, the most important modern school that deals with this issue, the development of this technique and its relationship with other intellectual ideologies, and the role metaphor plays in interpreting the meaning of the linguistic discourse especially in conveying political message. The study allows the formulation and the creation of a conceptual picture for the purposes of metaphor in the linguistic discourse used in Spanish press. It investigates discursive models from the Spanish press,

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Publication Date
Fri Nov 01 2024
Journal Name
Process Safety And Environmental Protection
Optimized ensemble deep random vector functional link with nature inspired algorithm and boruta feature selection: Multi-site intelligent model for air quality index forecasting
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Publication Date
Sun Feb 28 2021
Journal Name
Journal Of Economics And Administrative Sciences
دور الهندسة المتزامنة في تحسين التكلفة
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يهدف البحث الى دراسة وتحليل الهندسة المتزامنة (CE) وتحسين التكلفة(CO)، واستعمال مخرجات الهندسة المتزامنة كمدخلات لتحسين التكلفة، وبيان دور الهندسة المتزامنة في تحسين جودة المنتوج، وتحقيق وفورات في وقت التصميم والتصنيع والتجميع وتخفيض التكاليف، فضلاً عن توظيف بعض النماذج لتحديد مقدار الوفورات في الوقت ومنها نموذج(Lexmark) ونموذج (Pert) لتحديد الوفورات في وقت التصميم وقت لتصنيع والتجميع.      ولتحقيق اهداف 

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