bluuebunny/crossref_metadata_2025 huggingface dataset:
An Enhancement Coherent Code Discriminator for Tracking GPS Signal
Authors: Albu-Rghaif Ali , Abdulkadhim Hussein A.
Published: February 2021

Tracking the global positioning system (GPS) signals is a more important process in hardware/software GPS receivers. Any error leads to either provide inaccurate location fixing/measurement or lose signal lock in the tracking process. Delay lock loop and phase lock loop are responsible for synchronising with receiving code and wiping off the carrier frequency with Doppler frequency shift receptively. Code discriminator and code loop filter are characterised the delay lock loop, which is utilised to synchronise the generated code with received signal’s code. In this work, an enhanced coherent code discriminator is designed in order to enhance the tracking process. Our discriminator has been analysed and compared with the coherent and non-coherent discriminators. Also, real GPS data is employed for different GPS satellites situations, in these comparisons. The processing results showed that our design has better performance than the coherent and non-coherent code discriminators for the strong and weaker GPS signals in terms of reducing errors of discriminator output. Moreover, a standard deviation and root mean square is also utilised to evaluate our design, and the results revealed that all obtained values are less than the coherent and non-coherent code discriminators.
Optimized Design for Improving the Performance of Stator Three-Phase Induction Motor for Industrial Applications Using HHO Algorithm
Authors: Mohammed Khalid G , Khalaf Nasrallah S , Yas Qahtan M , Hutaihit Maha A
Published: February 2021

In the present study, an optimal design method of industrial induction motor is developed. All design equations are formulated, all constraints and limitations requirement are assigned. Harris Hauk Optimization (HHO) is a robust heuristic optimization technique; it is considered fairly new. It is adopted to find optimal values of parameters to achieve the best efficient design. An industrial practical sample is suggested to validate the proposed performance improvement method. For comparison, Particle Swarm Optimization (PSO) is used as another robust optimization widely used. Some of important performance parameters of induction motor design system were compared with the performance of convergent systems in size available in literatures.
The Smart Parking System Using Ultrasonic Control Sensors
Authors: Allbadi Yousif , Shehab Jinan N. , Jasim Musaab M.
Published: February 2021

Over the past decade, the concept of smart cities has become very popular thanks to the Internet of Things (IoT) development and expansion for increasing the reliability of building the infrastructure of cities. The continuous increase of vehicles in the streets with the lack of car parking is becoming a problem in most urban cities. Therefore, the demand for smart car parking systems is increased for helping drivers to find a suitable car space quickly. This paper presents a smart parking system using infrared and ultrasonic sensors, which is controlled by Arduino Mega 2560. The Radio Frequency Identification (RFID) reader provides authorization to enter the smart parking system. On the other hand, a mobile application is added to allows users to know about the empty spaces based via WiFi application. This smart parking system is implementing in a small-scale model, and the results show that simulates the car parking with the mobile application, all the sensors, and the Liquid Crystal Display (LCD) screen display, to describe a view of the system architecture.
On the Trade-offs of 5G networks and Beyond
Authors: Ahmed Al-Karawi Yassir Ameen , Taher Montadar Abas , Ahmed Riyadh khlf
Published: February 2021

Towards offering productive organizations and clean condition, green organization is an essential for the future correspondence ages. This paper talks about the comprehensive and best compromises that are simultaneous with empowering the green advancement. This paper numerically assesses the impacts of the numerous measurements and factors, for example, powering sufficiency, deployment cost, revenue, economy dimension, delay up on CO2 emission, bandwidth, consumed power, cost efficiency, transmitted power, energy efficiency and spectral efficiency. This work likewise shows that green situated organizations may think about generally significant expense productivity. In like manner, the organization suppliers and financial specialists can decide after utilizing the suitable wellspring of vitality and supporters one of them.
Geometry Modification Effect on The Aerodynamic Characteristics of NACA 0015 Using CFD.
Authors: Abed K N , Almahdawi YA J , Kader E E
Published: February 2021

The airflow around two-dimensional standard NACA 0015 airfoil effect was studied and analysed. The study was performed by simulating three geometrical modification airfoils (bumps NACA 0015, multi-element NACA 0015, and a backward-facing step NACA0015). Using SST (Shear Stress Transport) turbulence model and compared with standard NACA 0015 was the performed methodology. The research focuses on two cases (at different attack angles from 0 to 18 degrees with Re=1.65x106). Case I: the numerical analysis method data for the coefficient of lift of standard NACA 0015 (baseline case study) is compared to the previous experimental data. Case II: the coefficient of pressure, coefficient of lift, the contour of static pressure, and the velocity contour for standard NACA 0015(chord length c=1m) were calculated and compared with three geometrical modifications NACA 0015 airfoil. The CFD software ANSYS FLUENT version 17.1 was used for the computations in the present study. As a result, the geometrical modification influences on the aerodynamic properties of NACA 0015 was investigated. Compared to standard NACA 0015 airfoil, a significant improvement in the lift coefficient for multi-element NACA 0015 was noticed especially at the angle of attack (6°,14° and 18°) while slight improvement was noticed in the lifting coefficient for the other two models (bumps NACA 0015, and a backward-facing step NACA0015) at AOA 14 degree.
Experimental Study of Forced Convection Heat Transfer through Porous Media inside a Rectangular Duct of Fully Developed Region
Authors: Mahdi A N , Hasan M R , Rasheed S A
Published: February 2021

This prospective study was designed to experimentally investigate the effects of inserting copper mesh in fully developed turbulent flow on the flow and heat transfer characteristics. Experimental work includes designing and manufacturing the test section of rectangular duct with dimensions of (30*3*40 cm) with aspect ratio and hydraulic diameter of 10 and 5.45 mm respectively. A constant heat flux ranged (1.5*102– 1.8*102W/m2) was applied to the lower surface of duct with Reynolds number range (3.3*104– 4.8*104). The porosity rang of (0.98 – 0.99). Also, the effects of porous height ratio (full and partial filling) were considered and considered air as working fluid. The results indicate that inserting mesh wire leads to enhance heat transfer coefficient and increase pressure drop. Taken together, these results show that the obtained values of performance enhancement criteria (PEC) ranged (1.01 -1.98 ), the enhancement in heat transfer coefficient is 315% duo to wire mesh insert. Also, from obtained results empirical correlation for friction factor and Nusselt number were suggested.
Simulation between Soldering and Brazing of Copper at 450 Temperature by Zn-Sn Fillet Alloy
Authors: Kahlol Kadhim K. , Aldhaidhawi M , Nawi Sami A.
Published: February 2021

In this research, a comparison between Soldering and Brazing welding of pure copper metal using a (Zn-Sn) alloy filler was numerically investigated. The welding operations on the eight pieces with dimension (30mm x 20mm x 2mm) were carried out used (Auto Desk Inventor program) to prepare four samples, while the simulation was conducted on these samples by utilized the (COMSOL Multiphysics 4.1 program) to investigate the heat distribution and tensile stress. The simulation study results showed that the thermal distribution of Soldering welding was less than that of the Brazing welding in the area between (40-60 mm) and the maximum temperature of Soldering welding in that region was (405 °C), while the highest temperature for the Brazing welding in the same area reaches to (449 °C). The total displacement of the Soldering welding was up to1.9 x10-7 mm greater than that of the Brazing welding when the shedding stress equal to 5x104 N/ m2
Numerical response of aluminium plate (6061-T6) under dynamic loadings.
Authors: Nassir Nassier A. , Hassan Ayad K.
Published: February 2021

The response of aluminium plates (6061-T6) under low velocity impact is investigated numerically using ABAQUS software package. Firstly, the effect of the sample thickness on the perforation resistance of the aluminium plates is undertaken. It was shown that the perforation behaviour of the plates investigated increases with the target thickness and the maximum resistance to perforation, for the range of thicknesses investigated, was achieved using 4 mm thick panels. In order to capture the influence of the projectile shapes on the perforation behaviour, the aluminium plates were impacted with different head shapes impactors. The results showed that plates impacted with a flatted impactor offer the highest perforation resistance. Moreover, the results showed that changing the size of the targets has no significant change on the dynamic behaviour of the plates investigated in this study. Finally, it is suggested that the finite element models developed in this study can be used to capture the effect of the geometric and loading conditions of aluminium plates under perforation by low velocity impact.
Influence study of porous material and diameter on heat transmission from corrugated walls cavity
Authors: Sadeq Mays Subhi , Kadhi Zena Khalefa
Published: February 2021

Experimental study of heat transfer by free convection in a cavity filled with a porous medium. The study carried out on three forms of cavities (a cavity with flat walls, opposite walls, and similar walls), for the wavy wall cavity the (Asp=1), where a regular thermal flux was applied at the bottom with five values ranging between (500-2000) W/m2 by using five voltages (8,10,12,14 and 16) W. The side was completely insulated to be adiabatic and the upper surface of the cavity is exposed to free convection. The sand (1 mm and 3 mm) and glass (1 mm and 5 mm) were used as a porous medium of the three forms of cavities that have been studied. The experimental results show that the cavity with opposite walls gives the largest difference in temperature, as this difference is the basis for studying the other parameter. The lower thermal conductivity of the materials gives the greater heat transfer process, and this was demonstrated by the materials used, where sand gave the best heat transfer. When the diameter of the porous material increases, the temperature difference will decrease, and accordingly the heat transfer coefficient of free convection increases.
Numerical and experimental Study of Heat Transfer Enhancement in Contour Corrugated Channel Using nanofluid and Engine Oil
Authors: Khata Naseer Dawood , Kadim Zena Khalefa , Khalaf Kamil Abdulhussein
Published: February 2021

Research on improving heat transfer methods in heat exchangers has received wide attention in response to the increasing demand for high-efficiency devices in this field. Wherefore, the corrugated wall is one of the many suitable techniques used to enhance the heat transfer in heat exchangers. In the present investigation, laminar flow thermal and hydraulic efficiency of the trapezoidal, and straight counter heat exchanger with SiO2/water nanofluid and engine oil was carried out numerically and experimentally over Reynolds number ranges of 1100-2300 for nanofluid and 0.250 for engine oil. The results indicate that the numerical simulation of the laminar flow of nanofluids was performed with fractions of 0-4% volume. It should be noted that SiO2/water nanofluid has resulted in a significant improvement in heat transfer for all Reynolds numbers. Moreover, The error deviation of the Nusselt number is 0.0102% and 0.0208% between numerical and experimental work and the error deviation of the pressure drop is 0.0512% and 0.0325% between numerical and experimental work over the Reynolds number of 2300. The use of corrugated surfaces in reverse heat exchangers with nanofluid can improve heat transfer in many engineering applications, therefor the improving of the design and engineering parameters of a heat exchanger increases the heat transfer and makes it more compact, which in turn increases the efficiency of the thermal process, which leads to saving operating costs.
Numerical Model of Seepage Analysis and Slope Stability for Horan Dam H4 in Iraq
Authors: Mahmoud Ahmad I , Hussein Haitham A , Khaled Zeyad S
Published: February 2021

Horan Dam H4 is an earth dam located 18 km northeast Rutba town in Anbar province in Iraq. The main objective for dam construction is to save rainfall for agriculture purposes and some household uses. In this study, a mathematical model is developed to analyze water seepage through the dam under steady state. The upstream and downstream slopes stability of the dam are also evaluated by using four methods which are: Bishop, Janbu, Morgenstern-Price, and Ordinary method. In addition, a two-dimensional finite element model was developed using GeoStudio program. The results of seepage analysis clearly show that Horan Dam H4 is safe against failure. Furthermore, the obtained factor of safety of upstream and downstream slopes stability proves that the dam body is stable based on Janbu’s method of minimum value. Moreover, it was found that the soil shear strength parameters highly influence the dam stability in steady state condition.
Groundwater Modeling of Ahmed Taher and Bakhtiari areas southwest of Khanaqin Basin in Diyala Governorate – Iraq
Authors: Jalut Qassem H.
Published: February 2021

A foretelling of the groundwater level declining is substantial for the administration of subsurface water resources system, particularly in dry and semi-dry zones (area under this study), in which ground-water is the main exporter for agrarian and Household requirements. The purpose of this study is to investigate the influence of the increasing withdrawal rates from the aquifer on the condition of the groundwater. In addition to the effect of the decreasing recharge rate on the groundwater for the area under study. The study area (the southwest part of Khanaqin city) extended over 129 km2 was simulated using the mathematical model (GMS10-MODFLOW2000). Under a steady-state calibration process, good matching between model and observed groundwater head values has been found. To observe and evaluate the competence of the groundwater water system, five different scenarios have been used for the unsteady state. The first case used as a reference case for comparison, in which the existing withdrawal rates were modeled, after that the discharging rates will be increased up to (50 %, 100 %, and 200%) on the current rates through the next ten years. For the fifth case, the recharge rate was decreased by up to 25% by keeping the same condition applied in the previous cases. Maximum drawdown values resulted from these scenarios are equal to (11.58, 19.14, 27.58, 46.82 and 48.35 m) respectively. According to the drawdown map, the maximum value recorded on the left side of the modeled region in the study area, and the minimum was recorded in the area near Al-Wand River.
Assessment the relationship between air pollutant concentrations and meteorological factors in Baghdad city, Iraq
Authors: Hussein Ahmed Alaa , Mahdi Zahraa S.
Published: February 2021

Meteorological parameters directly effect on the amount of pollutants in the atmosphere as well as the period of their stay in it, and to verify this effect, the current study was conducted to find the relationship between pollutants (CO, NO, NO2, NOx, PM10, SO2) and meteorological parameters (wind speed, rainfall, air temperature, relative humidity, and atmospheric pressure) for Baghdad city from 2017 to 2019. The results showed increase in monthly average of wind speed in 2018 compared to 2017 and the decrease in the monthly average of relative humidity in 2018 compared to 2017, negative relationship between the monthly average of wind speed and the concentrations of pollutants (CO, NOx, SO2) and a positive relationship between this pollutants with relative humidity, positive relationship between PM10 and wind speed and the presence of a negative relationship between PM10 and relative humidity. Most monthly average levels of PM10 was higher than EPA limits due to the increase in wind speed, as the wind increased PM10 concentration in the atmosphere due to the lack of Vegetation cover around the Baghdad city also due to the scarcity of water and increase in desertification of agricultural lands and converting them to residential lands randomly and by unpaved roads, which made the wind speed an important and influential factor in increasing the concentration of PM10 and not a mitigation factor as is known. The Pearson correlation coefficient ranged from weak to medium between pollutants and meteorological parameters except CO with temperature, relative humidity, and atmospheric pressure in 2018 was a strong. The equations of CO and PM10 with meteorological parameters in 2018 can be adopting.
A Critical Review on Expansive Soils Including the Influence of Hydrocarbon Pollution and the Use of Electrical Resistivity to Evaluate their Properties
Authors: Mosleh Ameerah T , Al-Obaidy Nesreen K
Published: February 2021

This paper reviews the studies on expansive soil with a main focus on failure mechanism, financial losses, mineralogy, determination of swelling parameters and others. Effect of hydrocarbon pollution on geotechnical properties of expansive soil was presented. The paper discussed the assessment of electrical response of contaminated swelling soils. Wide extend of expansive grounds around the world and the serious impact created on infrastructures requires to identify its influential aspects and the appropriate treatments. Also, it was found that petroleum product affect significantly on the basic properties of swelling soils such as gradation, consistency, compaction, swelling and others, and electrical resistivity can be employed to reveal the electrical characteristics of polluted expansive soil.
Effect of Screw Piles Spacing on Group Compressive Capacity in Soft Clay
Authors: Jamill Abeer S , Abbas H O
Published: February 2021

Screw piles are considered as one of the solutions in different complications projects. Performance of circular screw piles group subjected to compressive load and embedded in two layers; soft clay and compacted sandy soils is investigated in this study. The thickness of two layers soft clay and sand soil is 250 mm and 350 mm respectively which are prepared after compacted to sub layers in the container. By choosing different slenderness ratios of L/ D 25, 32 and 39, many model tests were achieved on screw piles group. Single and double helix plates were used in screw piles with constant of helix spacing 60mm. A square pattern of screw piles group with different spacing between piles (1.5Dh, 3Dh, 4.5Dh), where Dh is diameter of helix is adopted in this study. The results of this study showed that the ultimate capacity of piles group was increased by increasing the spacing between the piles until reached spacing 3Dh then begin to decrease when piles extended in sandy soil, while in soft clay the ultimate capacity increase with decrease piles spacing in two cases single and double helix. The increasing percentages for pile spacing 3Dh and 4.5Dh are (55.3% and 39.4%) respectively for L/D ratio 32 and (27.2% and 23.8%) respectively for L/D ratio 39. Also, it is recommended to use screw piles group in case of deep layer of soft clay laying on sandy layer due to high increase in compressive resistance capacity of group when extended in sandy layer.
Structural behavior of MRPC beams exposure to riverine simulated circumstances using GFRP and CFRP bars
Authors: Wenas Abeer Hassan , AbdulKareem Wael Shahadha , Mushatat Haider Amer
Published: February 2021

Reinforced polymer bars could potentially be used with fiber as a strengthening technology in MRPC. The main objective of this paper is to study the influence development of the flexural behavior of MRPC beams after 120 days of virtual corrosion-exposure in riverine simulated circumstances using GFRP and CFRP bars. Nine beams were tested via a two-point loading method up to failure, 1200 mm long, (200x100mm) cross-section. The water/binder is chosen to be 0.14 by weight. Silica fume was replaced by 8% weight of cement. The dose of superplasticizer used to the total binder weight was 0.41 percent. Three types of flexural reinforcement ratios were used individually per each cross-section; GFRP, CFRP, and traditional steel rebar, with a nominal diameter of 10 mm. The compressive strength of MRPC is 80 MPa. The experimental evidence indicates that GFRP and CFRP bars used with MRPC have higher tensile strength and anti-corroded bars. Also, the load results indicate that CFRP bars are more efficient than GFRP bars and steel rebar. Finally, the behavior of MRPC beams neither GFRP and CFRP bars submerged in Tigris river water did not chemically affect. The author recommended replacing steel rebar with GFRP and CFRP bars to improved structural behavior.
Using Phase Change Material to Improve Asphalt Pavement Behavior
Authors: Salman Maryam Mohammed , Abd Alwahab Omar Adel
Published: February 2021

This research is an attempt to use PCM technology in order to protect and treat the asphalt pavement from the influence of temperatures and thus not to crack the road pavements. Applying the phase change materials in roadway traffic domain is becoming an exploration research, although the PCM have been used in many fields. Depending on the properties of latent heat, we can apply the phase change materials to control and regulate temperature of asphalt pavement and keeping mix feasibility. Asphalt pavement is a material that can heat up to 60°C due to solar irradiation in summertime because of their excellent heat-absorbing properties. Using the PCM can treat the asphalt mixture pavement cracks related to temperature, enhance the performance of asphalt concrete pavement, and prolong the service life of asphalt concrete pavement. We address the procedure bitumen penetration grade 50/60 was used in this test. In this study, gravel and sand are used as coarse and fine aggregate respectively in hot mixture asphalt. In order to apply PCM in asphalt concrete pavement, mechanism of controlling temperature, road performance and mixture design method of asphalt mixture have been considered. Results show that maximum temperature of surface and bottom respectively is (43.41°C, 46.47°C), and the maximum absolute Delta (difference between surface and bottom) reached to 4.72°C.
Explicit and Combined Effects of Blast and Seismic Loadings on Tall Buildings with and without Shear Walls
Authors: Kadhum Ali K. , Abdul-Razzaq Khattab S.
Published: February 2021

This paper aims at comparing seismic (EQ) and blast (TNT) loadings using different TNT weights on 12-storey reinforced concrete residential building with and without shear walls. These types of loading should be taken into considerations now in Iraq. The explosions besides earthquakes must be studied in Iraq to avoid significant losses in the lives of people and their public and private property. The same reinforced concrete multistory building was designed with three different TNT weights; 100, 350 and 750 kg in order to discuss drift, displacement and story shear. A commercial package ETABS2018 was used to analyze this 36-meter-high building. The building was designed according to ACI 318-14 and US Department of Defense TM5-1300 for blast load. As for the blast load, in case of shear wall existence, the maximum increase in drift was seen on the 11th and 12th stories about 1306-187% and 1232-175 %, respectively for each TNT weight compared with EQ. The maximum increase in drift was found on the 11th and 12th stories about 4236-618% and 2646-386% for each TNT weight. The maximum increase in story shear was seen on the 2nd and 3rd stories 5150-698% and 4625-618% for each TNT weight compared with EQ.
Confinement of Concrete by Fiber Reinforced Polymer Tube: A Review
Authors: Sachet Wrood H. , Salman Wissam D.
Published: February 2021

Researchers studied a lot of strengthening techniques of concrete, one of which is the technology of concrete confinement. This technique is common to utilize fiber fabric impregnated with epoxy resin adhesive. Relevant applications mainly include strengthening the existing structure and new structural construction. This paper presents a review of previous studies on the confinement of concrete using fiber-reinforced polymer (FRP) tubes. Four main parameters were investigated in this study: the number of layers of FRP tubes, cross-sectional shape and slenderness ratio, material types of FRP tubes, and concrete types. The results of the investigation showed that increasing the number of FRP tubes resulting in a significant improvement in the behavior of confined specimens, circular cross-section specimens exhibited better behavior than square. Also, the behavior of confined square specimens improvement with increasing the angular radius. A carbon fiber reinforced polymer tube is better than (aramid, glass, and basalt) fibers. Finally, the concrete confining technique significantly improved the behavior of specimens regardless of the type of concrete confined, and the effect of confining decreases with the increase of compressive strength of the concrete confined.
Geopolymer Concrete, Mortar, and Paste: A Review
Authors: Sachet Wrood H. , Salman Wissam D.
Published: February 2021

The problems of global warming and environmental pollution with gaseous and solid wastes, made researchers think of finding effective alternatives to reduce the proportion of carbon dioxide in the atmosphere and make use of solid waste for iron manufacturing stations and power production stations. Thus, geopolymers are considered one of the most promising solutions in the field of structural engineering. Therefore, this paper presents a review of previous studies on geopolymer mixtures, which were investigated in three main parameters, included: slag addition, solution ratios, adding fibers, and Nano silica. The results of the previous investigation showed that the compressive strength increased with the increase in the slag ratio. At certain proportions, the compressive strength increases with increasing the sodium silicate to sodium hydroxide and increasing the sodium hydroxide concentration (M). While it was reduced fresh properties such as flow-ability and setting time. It was also found that the addition of fibers or Nano silica improved the microstructures of geopolymers, and thus a significant improvement in tensile strength and compressive strength. Finally, the addition of external water was found to improve flow-ability but reduce compressive strength, while the addition of the superplasticizer in certain proportions improves fresh properties.
Assessment of Flood Frequency Using Maximum Flow Records for the Euphrates River, Iraq
Authors: Saeed Saeb F. , Mustafa Ayad S. , Aukidy Mustafa Al
Published: February 2021

A flood frequency analysis (FFA) on Euphrates River in Iraq has been carried out. Gumbel, generalized extreme value (GEV) and log person type III (LP3) probability distributions were employed for the simulating of flood flow using annual peak flow data from two gauging stations on Euphrates River. The first gauging station is Qaim station and recorded data for the period (1981-2018) was adopted the second gauging station is Hit station and its adopted records are for the period (1985-2018). The collected data was evaluated and tested for independency, stationary and homogeneity. The predicted flood flows of different return periods (Tr) i.e., 5, 10, 25, 50, 100 and 200 years are obtained and compared. The results show that the estimated flows of all the return periods does not exceed the current average carrying capacity of the river and this is due to the large number of dams built outside Iraq in Turkey and Syria. The estimated values for 100 and 200 years return period for Qaim gauge station are 2030 and 2250 m3/sec respectively while for Hit gauge station are 1480 and 1580 m3/sec respectively. Also, the results reveal that the river’s flow can be satisfactorily expected by any one of the used probability distribution methods; however, the generalized extreme value (GEV) was found to be the better fitted as shown by the goodness of fit test
Using Wasted Rubber Material for Reducing Loads and Energy Dispersal in Building Industries: State of the Art
Authors: Jassim Teeba A. , Zhuang Bozhou , Ibrahim Amer M. , Ali Ibrahim A.
Published: February 2021

The accumulation of rubber tires poses a great danger to the environment, especially since the number of cars is constantly increasing. Therefore, at the beginning work was done to recycle these tires and use them as an alternative to the natural aggregate used in concrete. It was also used in asphalt used in roads. Packaging for the Shear Connecter used in composite section. As this work gave excellent results in reducing the hardness of the shaker contactor, increasing its durability and resistance, and also preserving it from corrosion by rust. Waste rubber was also used to covering the bolts used to connect the beam with the column in steel structures. Where the presence of rubber gave a high ability to dissipate energy when the steel structure is subjected to a seismic load. It also worked to increase the displacement and increase the durability of the steel structure and also reduce the friction between the bolts and their holes. The presence of rubber around the bolt also delayed the failure time of the steel structure and thus the important aim of the research work has been achieved, which is to maintain the safety of people when the structure is exposed to an earthquake load.
Forecasting construction time for road projects and infrastructure using the fuzzy PERT method
Authors: Nemaa Zahraa Kadhim , Aswed Gafel Kareem
Published: February 2021

It is essential to organize and plan any project at all stages, from start to finish; however, it is also necessary to certify completion by means of correct and effective methods. Scheduling projects using scientific approaches and sophisticated scheduling tools helps guarantee to project completion by the scheduled dates, as well as allowing institutions and municipal departments to make accurate estimations for project execution. The construction of roads includes several activity packages, one of which is the generation of road infrastructure such as that related to the sewer work (such as water and wastewater), the drilling and pouring work, the electrical work, and finally the paving. One of the most difficult jobs facing a manager in terms of such a project is the scheduling of activities over time. In many projects, the scheduling is done compactly, such that each activity that matches one scheduled in previous projects is scheduled but not detailed, with estimates based on previous overall times. In this research, however, each major activity was divided into several sub-activities to allow more accurate calculation of duration based on several criteria that affect the activities’ use of time. Three timings were thus estimated for each activity: a pessimistic time, an optimistic time, and a normal time. The PERT method was improved by using a Fuzzy Delphi technique to estimate the actual time required to implement each activity. The overall scheduling of a project in Karbala city, the rehabilitation of the road connecting the intersection of the Al-Ghadeer district to the intersection of the Al-Mudraa district was done in this manner. The project implementation period was predicted at 301 days, which is very close to the 322-day actual duration in which the work was carried out. The findings confirmed that the improved PERT method using the Fuzzy Delphi technique was the most accurate way to predict execution time.
Impact of illegal use of storm network on Tigris River using supervised classification technique
Authors: Shamkhi Mohammed S. , Abd Nariman N.
Published: February 2021

This paper studies the impact of the stormwater network outfall of the Al-Rabee Quarter on the Tigris River. Residents of the district use the storm network for contacts of illegal sewage. Household wastewater is discharged through the storm network directly into the river without treatment, which affects the water quality. Storm network model was developed and use a dynamic wave approach in routing hydraulic flow. The model was simulated based on the calculations of the quantities of domestic wastewater. The supervised classification was used in the spectroscopy of the satellite image of the river by the ArcGIS software in determining the effect of the storm network outfall on the Tigris River. The image was classified into four categories, which are pure water, polluted water, shallow water, and plants. Storm network data was obtained the from Wasit Sewerage Directorate in the form of ArcGIS files. The QuickBird satellite with a high spatial resolution of 25 cm was bought in 2019.

The results of the study indicated that sewage quantities were discharged into the river, which led to water pollution by 17.79% from the river surface area. It was concluded from the results that the outfall of the storm network has a high impact on the river water quality. Therefore, this study suggests implementing and managing a separate sewage network that is directed directly to the treatment plants. A stormwater management model (SWMM) was used to simulate a storm network as a sewage network in dry weather.
Photonic-crystal lasers with high-quality narrow-divergence symmetric beams and their application to LiDAR
Authors: Yoshida Masahiro , De Zoysa Menaka , Ishizaki Kenji , Kunishi Wataru , Inoue Takuya , Izumi Koki , Hatsuda Ranko , Noda Susumu
Published: February 2021

Light detection and ranging (LiDAR) is a key technology for smart mobility of robots, agricultural and construction machines, and autonomous vehicles. However, current LiDAR systems often rely on semiconductor lasers with low-quality, large-divergence, and asymmetric beams, requiring high-precision integration of complicated lens systems to reshape the beam. Also, due to the broad linewidth and the large temperature dependence of their lasing spectrum, a bandpass filter with broad bandwidth must be used in front of the detector, so the detected signal is affected by noise from background light such as sunlight. These critical issues limit the performance, compactness, affordability, and reliability of the LiDAR systems. Photonic-crystal surface-emitting lasers (PCSELs) have attracted much attention as novel semiconductor lasers that can solve the issues of conventional semiconductor lasers owing to their capability of high-quality, very-narrow-divergence, and symmetric beam operation supported by broad-area band-edge resonance in their two-dimensional photonic crystal. In this paper, we show the progress and the state of the art of broad-area coherent PCSELs and their application to a time-of-flight (ToF) LiDAR system. We first review the progress of PCSELs made so far. Next, we show recent progress based on PCSELs with a double-lattice structure that enables higher-power and narrower-divergence operation while keeping a symmetric beam shape. By optimizing the double-lattice photonic crystal and the reflective properties of a backside distributed Bragg reflector (DBR), we achieve a high peak power of 10 W while maintaining a nearly diffraction-limited beam divergence of ∼0.1° (FWHM) from a 500 µm diameter resonator. Using this PCSEL, we construct a LiDAR system that uses no external lens system in its light source and demonstrate highly spatially resolved ToF sensing (measurement range of ∼20 m), which is appropriate for autonomous robots and factory automation.
Mesoscale modeling of metal-based selective laser melting: evolution of the vapor capillary
Authors: Allen J B
Published: February 2021

In this work we apply a multiphysics approach to selective laser melting to model the evolution of the vapor capillary, taking into account the effects of variable laser intensity, scan speed, and spot size. Restricting the work to a single line scan with a continuous wave laser, we focused on the application of Ti-6Al-4V alloy. In addition to heat, momentum and mass transfer, the solid/liquid/vapor interface was simulated using a front-tracking, level-set method, and an imposed recoil pressure was used to model the evolving vapor capillary. Initial benchmark applications focusing on an evolving melting front served to validate the heat transfer/phase change numerical framework.
Study on hardness and wear resistance of shot peened AA7075-T6 aluminum alloy
Authors: Win Khun Nay , Quang Trung Pham , Lee Butler David
Published: February 2021

AA7075-T6 aluminum alloy samples were shot peened at various shot peening pressures in the range of 10–70 psi to study their mechanical and tribological properties under dry and mineral oil lubrication conditions. The surface roughness of the shot peened AA7075-T6 samples apparently increased with increased shot peening pressure. The best bearing surface was obtained when the shot peening process was carried out at the highest shot peening pressure of 70 psi. It was found that the increased shot peening pressure increased the hardness and decreased the wear of the shot peened samples. The shot peened samples tested under the mineral oil lubrication condition also had lower wear for higher shot peening pressures due to the combined effects of their higher surface wear resistance and better bearing surfaces. The results clearly showed that using the mineral oil lubricant during sliding apparently decreased the wear of the shot peened samples as a result of the lubricating effect of the lubricant. It could be deduced that the tribological properties of the shot peened AA7075-T6 samples under the dry and lubrication conditions were affected by the shot peening pressure.
Music: A Very Short Introduction
Authors: Cook Nicholas
Published: February 2021

Music: A Very Short Introduction is a study of music and thinking about music, focusing on its social, cultural, and historical dimensions. It draws on a wealth of accessible examples, ranging from Beethoven to Chinese zither music. This VSI also discusses the nature of music as a real-time performance practice; the role of music in social and political action; and the nature of musical thinking, including the roles played in it by instruments, notations, and creative imagination. Digital technology has had a massive impact on the production and consumption of music, including transforming participatory music-making and the music business. This in turn has affected music’s position in a globalized world. In many ways music has changed out of all recognition over the last twenty years.
Introduction
Authors: Cook Nicholas
Published: February 2021

‘Introduction’ describes a forty-second television commercial for Prudential pension plans in order to illustrate music’s ability to convey complex cultural meanings. Music encodes values, people’s cherished beliefs about the world they live in; it is an entertainment, one of life’s great pleasures. But it also penetrates deep into society, culture, and identity. It is important for any study of music that aims to reflect the importance of digital technology and globalization to place equal emphasis on music as real-time performance and the processes of creative imagination in music.
Thinking in music
Authors: Cook Nicholas
Published: February 2021

‘Thinking in music’ examines how the culture of music involves a system of established metaphors that culture members share—what may be loosely called a language. This is the condition of writing, talking, or thinking about music, but more than that, it is the condition of music’s existence as cultural practice and product. Musicians internalize properties of instruments and notations: these are key ways musicians think not just about but in music. The creative imagination can be seen at work through the example of Beethoven, whose compositional process—based on the piano and on sketches—became central to a whole tradition of thinking about classical music.
The presence of the past
Authors: Cook Nicholas
Published: February 2021

‘The presence of the past’ traces a number of key ideas going back to the 18th century that still condition music and thinking about it today, largely focusing on classical music, but situating it in relation to popular culture. A distinction needs to be drawn between ‘classical’ (small-C) and ‘Classical’ (big-C) music: Classical (big-C) music is a narrower term referring to a particular series of developments centred on Vienna and the Austro-Hungarian Empire during the late 18th and early 19th centuries—developments in which Haydn, Mozart, and Beethoven played a key role, and which eventually led to the idea of music as its composer’s self-expression. A very different idea of what music is and what it is for emerged, centred around the consumption rather than the creation of music, linked to major social and technological changes, and this has given rise to today’s culture of musical pluralism.
Marketing research
Authors: Le Meunier-FitzHugh Kenneth
Published: February 2021

This chapter examines marketing research, one of the most engaging parts of marketing, as it is the opportunity for organizations to evaluate marketing performance, uncover customer behaviours, and explore their preferences. Marketing research covers a range of activities which may be positioned as either problem-identification research or problem-solving research. Sources of data and information for marketing research include secondary or desk research; primary or field data; quantitative data; and qualitative data. Meanwhile, marketing research methods are reviewed including surveys and questionnaires; focus groups and interviews; experiments and observations; and neuromarketing. The chapter then considers how sampling is widely used in primary research. It also looks at customer insights and big data.
Promotions (marketing communications) and social media
Authors: Le Meunier-FitzHugh Kenneth
Published: February 2021

This chapter explores promotions, which are made up of a range of marketing communication tools that are critical in supporting the organization’s offer and conveying their brand values. They are designed to reach, interest, and engage customers in conversations and to encourage them to purchase their products. Promotional tools include advertising, sales promotions, public relations, direct marketing (on- or offline), sponsorship, and personal selling. Today, communication activities are being totally reinvented by the growth of social media and digital marketing. Indeed, the development of different types of social media has created opportunities to develop digital marketing that has an immediacy of interaction and increased intimacy with potential customers.
Price and place (managing channels)
Authors: Le Meunier-FitzHugh Kenneth
Published: February 2021

This chapter studies the elements of price and distribution, which are important parts of marketing strategy. Pricing is critical in that it directly relates to the revenues generated by the organization and consequently affects its profitability. Pricing also has a strategic impact as it can be used to create competitive advantage in the marketplace by either undercutting the competition or supporting premium positioning statements. Meanwhile, place decisions are about how the product reaches the customers and are therefore about forms of distribution. Distribution can be mass, selective, or exclusive, and can be achieved through direct or indirect channels to market.
1. The Second World War and the destruction of the old order
Authors: McMahon Robert J.
Published: February 2021

‘The Second World War and the destruction of the old order’ focuses on the Second World War, the most destructive conflict in human history. The death and destruction precipitated by the war left not only much of Europe and Asia in ruins but the old international order as well. The origins of the Cold War lay in the intersection between a war-shattered world and the conflicting recipes for international order that the United States and the Soviet Union sought to impose on that world. The Soviets and Americans each saw themselves acting out of noble motives—acting to usher humanity into a new age of peace, justice, and order.
3. Towards ‘Hot War’ in Asia, 1945–50
Authors: McMahon Robert J.
Published: February 2021

‘Towards ‘Hot War’ in Asia, 1945–50’ discusses how Asia became the second major theatre of the Cold War, considering the US occupation regime in Japan. As many as 6 million soldiers and civilians would ultimately lose their lives in Cold War-related conflicts in Korea and Indo-China. Just as the Chinese civil war became inextricably entangled with the Cold War, so too did the independence struggles in post-war Southeast Asia. It was the outbreak of the Korean War in June of 1950, moreover, that precipitated the first direct military showdown between US and communist forces and, as much as any other single event, turned the Cold War into a worldwide struggle.
5. From confrontation to détente, 1958–68
Authors: McMahon Robert J.
Published: February 2021

‘From confrontation to détente, 1958–68’ explores the events and forces that made the late 1950s and early 1960s a period of seemingly perpetual crisis. In the late 1950s, the Cold War entered perhaps its most dangerous phase, the time in which the danger of general nuclear war was highest. A succession of crises, culminating in 1962 with the epochal confrontation between Washington and Moscow over the presence of Soviet missiles in Cuba, brought the world perilously close to a nuclear conflagration. On both sides of the superpower divide, risk-taking and shrill rhetoric reached levels not witnessed since the late 1940s. The US involvement in Vietnam, particularly the Vietnam War, is an important part of this history.
7. The rise and fall of superpower détente, 1968–79
Authors: McMahon Robert J.
Published: February 2021

‘The rise and fall of superpower détente, 1968–79’ describes how the French term détente served as a convenient shorthand for the more stable and cooperative relationship being forged by the Cold War’s primary protagonists during the 1970s. The United States and the Soviet Union worked to lessen the danger of nuclear war through the negotiation of verifiable arms control agreements and to formulate a core set of ‘rules’ to govern their relationship. Nevertheless, competition continued, especially in the Third World. Each side, moreover, harboured a fundamentally different understanding about the meaning of détente. By the end of the 1970s, those problems had grown so severe that they brought the era of détente to an abrupt close.
8. The final phase, 1980–90
Authors: McMahon Robert J.
Published: February 2021

‘The final phase, 1980–90’ recounts how the late 1980s witnessed the most momentous changes in the overall structure of world politics since the 1940s. Why did the Cold War end when it did? How does one make sense of a decade that opens with a rapidly intensifying Cold War and closes with a historic Soviet–American rapprochement, unprecedented arms control agreements, the withdrawal of Soviet power from Eastern Europe, Afghanistan, and elsewhere, and the peaceful reunification of Germany? These questions can be looked at by examining the Cold War’s final phase, including Mikhail S. Gorbachev’s accession as the general secretary of the Soviet Communist Party and the demolition of the Berlin Wall.