bluuebunny/crossref_metadata_2025_split huggingface dataset:
Damage assessment of RC voided slabs experienced extreme fire flame
Authors: Alawsi Manal A. , Mhalhal Jasim M. , Al-Gasham Thaar S. , Abid Sallal R. 
Published: February 2021

Abstract
The main objective of this study was to assess the damage level in reinforced concrete voided slabs experimentally after exposure to high fire flame. Accordingly, four analogous slabs were created using the same concrete strength with dimensions of 500 mm long×270 mm wide×90 mm deep. They contained fifteen plastic balls with a 70 mm diameter, placed in between the top and bottom reinforcement meshes. Three specimens were subjected to direct fire flame using a diesel furnace at 200 °C, 500 °C, and 800 °C for one hour. The fourth was left without burning for the contrast purpose. Afterward, the slabs were tested under uniformly distributed loads up to collapse. The results indicated that the slabs’ failure mode changed from combined flexural-shear to pure shear when the temperatures passed 200 °C. The residual strengths of 200-800 °C exposed slabs downed to 71.80% -52.00% relative to the unexposed one, respectively. As well, the ductility, service stiffness, and toughness of burned slabs remarkably decreased, approaching 65.97%, 54.18%, and 77.82%, respectively.
Bubble slabs burned at 800 °C with different periods
Authors: Al-Gasham Thaar S. , Mhalhal Jasim M. , Al-Magsusy Lamea J. 
Published: February 2021

AbstractThe bubble slabs are a modern type invented to reduce the self-weight significantly. However, limited studies were conducted on such slabs, and many influencing parameters still uninspected or need further investigations. The period of fire flame exposure is one of these factors. Hence, the current study was planned to examine bubble slabs’ behavior when burned at 800 °C for different durations. Four bubble slabs were designed in analogous specifics. Three slabs were exposed to direct fire flame of 800 °C for three durations: 1, 1.5, and 2 hours. The remaining one was kept without exposure. Just the burning operations had accomplished, the slabs were statically tested under the influence of uniform loads. The results indicated that exposed slabs’ failure mode changed to the shear mode, and the flexural cracks were limited. The slabs’ strengths decreased owing to fire flame, where the residual strength of burned slabs were 50.24%-20.78% of that of the control slabs. Besides, essential decays in the mechanical characteristics of burned slabs were observed compared to the control one.
Ideality factor of Al/nanosilver/PS/Si/Al sandwich structure
Authors: Ali Hanan R. A. 
Published: February 2021

Abstract
In this work, n-type (p-Si) porous Si nanostructures were fabricated by photochemical etching of n-type (p-Si) chips. The etching time of 20 min and the density of current of 20 mA / cm2 were examined to discuss their impact on nanopore array formation. Crystal size was assessed by XRD. AFM confirmed the non-metric size of porous Si showing a rough Si surface increased with etching time and increased the depth and width (diameter) of the surface etching. Colloidal silver nanoparticles were also prepared by laser ablation in liquid (LAL) with Nd: YAG laser pulses and an Ag target submerged in ethanol using laser fluorescence (1.32 J / cm2). The effect of laser flux on the physical properties obtained from this study of Ag nanoparticles has been studied. The energy band gap prepared for the Ag nanoparticles was determined from the optical properties and found between (1.85 eV). Optical constants of deposit film were obtained using transmittance and absorbance spectra. Electrical properties of prepared Al/Ag/PS/p-Si/Al sandwich Solar cells are represented by I-V characteristics under dark conditions.
Residential Load Scheduling Based Analytical Optimization Method
Authors: Sultan M J , Tawfeeq M A , Haider H T 
Published: February 2021

Abstract
Peak load periods in smart grids significantly affect the energy stability produced by energy suppliers. One of the important factors that distinctly affects the load during these periods is the household energy consumption. Thus, managing and improving energy demand for smart home appliances can effectively reduce the peak loads which represents a major challenge. This paper introduces a dynamic Analytical optimization Method (AM) to find the optimum managing for residential energy load. The results showed that the maximum load of total demand is decreased by 35%, as well as, the energy consumption cost bill is decreased by 44%. The results of proposed method are compared with two widely used optimization methods; Genetic Algorithm (GA), and Particle Swarm Optimization (PSO). Although the results of the proposed method showed a superior time saving for achieving the final results.
Design and Implementation of Constant Speed control System for the Induction motors Using Programmable logic Controller (PLC) and Variable Frequency Derive (VFD)
Authors: Khudier Khalid Hussien , Mohammed Khalid G. , Ibrahim Mayyadah Sahib 
Published: February 2021

Abstract
This paper presents an automatic speed control system on three phase squirrel cage induction motor using Programming Logic Circuit (PLC) and Variable Frequency Drive (VFD) techniques. The aim of this study is to obtain a constant speed of induction motors when these motors are exposed to variable loads. The required speed of the induction motor can be set as a numerical value by (PLC), while the actual speed of the induction motor can be measured by a tachometer which is equipped with (PLC) ) Through an Analog to Digital Converter (ADC). Then the two speeds are compared to the set point with minimum error to get the required constant speed. The control system designed to be tested with two stator poles number (two and four poles) of induction motors. The results have cleared that in spite of doubled the load 11 and 8 times respectively, but the yield average shaft speeds are almost constant 2891.15 rpm and 1402.45 rpm respectively.
Numerical Study of Latent Heat Storage Unit Thermal Performance Enhancement Using Natural Inspired Fins
Authors: Mahdi Mustafa S. , Khadom Anees A. , Mahood Hameed B. , Campbell Alasdair N. 
Published: February 2021

Abstract
Thermal energy storage plays an important role to control the intermittent nature of renewable energy. This paper presents a numerical study to the enhancement of the melting and solidification rates of phase change material (PCM) mounted in the annulus of a double pipe latent heat storage unit (LHSU). The enhancement is achieved by using the natural inspired fins (branch shape fins). One and two bifurcations branch fins were designed and their effect on the thermal performance of the LHSU was studied and compared with the longitudinal-finned. The result shows that the melting and solidification processes of the branch shape fins contributed to the improvement by about 44% and 46% respectively.
Geometric Form Algorithm for Data Hiding
Authors: Salih Abdulkreem Mohammed , Zaki Karam Mazin 
Published: February 2021

Abstract
Hiding digital data is one of the arts of hiding information in the internet. This technique has an important role in the field of information security. Transmission of information over communication networks exposes it to theft from attackers and hackers. One solution of avoiding this problem is to hide the information in image so that the targeted message will not be known to repel the attention of thieves. In the proposed algorithm, the hiding of data is based on rearranging the target data and distributing it in a frame called Geometric Frame (GF) that have dimensions with the same dimensions of the cover image. The proposed algorithm is able to achieve the basic metrics used in steganography. In addition, the secret key improves the security objectives. The image quality for stage image will be improved due to ability to choosing the suitable frame for message bits. The proposed Geometric Form algorithm shows a significant result compared with the other related works.
Evaluating Python, C++, JavaScript and Java Programming Languages Based on Software Complexity Calculator (Halstead Metrics)
Authors: Abdulkareem Sabah A. , Abboud Ali J. 
Published: February 2021

Abstract
Various software organizations used software metrics to assessing and assuring operation, maintenance, and quality of software codes. Halstead is an essential type of software complexity metrics used to measure source code complexity. We presented a comparative analysis study using this metric to benefit software testing process by showing the possibility of software metrics to measure the characteristics of the software in all its aspects. Halstead metric is used to analyse the written code in python, C, JavaScript and Java programming languages. It provides a better tool to evaluate the complexity level of the language and displays the differences levels of code complexity. The conducted experiments show that python is the simplest programming language and Java is the difficulty and more complex language than others. These results benefit the automation in software metrics computation to decide which programming language can produce high quality and the less complexity software.
Performance Analysis of Inter-satellite Optical Wireless Communication (IsOWC) System with Multiple Transmitters/Receivers
Authors: Majeed Majidah H. , Ahmed Riyadh Khlf , Alhumaima Raad S 
Published: February 2021

Abstract
The satellite communications networks have certainly been innovated recently by Inter-satellite optical wireless communication (IsOWC) networks. The prerequisite for next generation mobile satellite communication is superior multimedia facility for consumers at anytime and anywhere. The proposed optical communication system is designed and analysed to improve data transmission quality over the distance between two geostationary (GEO) satellites greater than 36000 km. This trend is to achieve high speed transmission with minimizing the presence possibility of free space loss in transmission that can occur in satellite communication via the longest range. Numerous transceivers IsOWC is a hopeful way to deal with be utilized related to different earth stations as a system utilized between the geosynchronous satellites. The wireless transmission creates the opportunity at high optical power without free space loss. The results of the simulated system showed that with 32 transmitters/receivers IsOWC, the Q-factor values of 36.526, 12.176 and 4.015 are obtained at 38000 km range at laser power of (19, 14 and 9) dBm, respectively. The proposed system is operated at 19 dBm optical power and different values of aperture size and the best values of Q-factor and BER are 41 and 10−250, respectively, for highest diameter value of 20 cm. The operation of the system with various values of bit rate is verified as well. It is seen that the best system performance is at 0.032 Gb/s bit rate and will be of lower as the bit rate increases until it roughly fixes at 32 Gb/s. This research offers the treatment for the transmission problem for ultra-speed application in mobile satellite systems.
SINR and Capacity Analysis for Multiuser MIMO Interference Channels
Authors: Naser Ahmed Abdulameer , Abdulameer Lwaa Faisal , Bayat Oguz 
Published: February 2021

Abstract
Multiple-Input-Multiple-Output (MIMO) has a significant effect on wireless communications due to providing high capacity and low BER as compared to the conventional wireless communications with SISO. Due to transmitting a large number of an independent signal from different users in different space-time approach, the BER performance suffers inferiority leading to decreasing in the system reliability. So, our work is based on maximizing the SINR of a multiuser (MU)-MIMO system by sending separate data of different users from one base station (BS) via a number of antennas with different time slots to a number of mobile stations (MS) each with more than one antenna technique. The proposed work considers one user as a desired user and others as interferer users when these data are propagating in multipath fading channel. BER performance as well as channel capacity for various diversity systems such as 2×2 and 4×4 are simulated. The numerical results obtained by computer simulation show that implementing 4×4 MIMO system gives gain of 1 dB as compared to the system implemented with 2×2 MIMO. The results show that when the 10 users communicate with the BS required SINR of 18 dB at 10−2 BER while for 20 users it requires a SINR of 20 dB at BER of 10−2. We can conclude that the BER is decreased and the capacity is increased with increasing the number of antennas when the system is under multiuser and multipath interferences.
Characterization of Multimode Interference Based Optical Fiber
Authors: Younus Shahad I , Al-Dergazly Anwaar A , Abass A K 
Published: February 2021

Abstract
In this paper, the fiber optic cascade based on multimode interference (MMI) is demonstrated and investigated via COMSOL Multiphysics software. Two different cascades were adopted in this work, namely, single mode–multimode–single mode (SMS) and single mode–No–Core–single mode fiber (SNS). The transmission spectrum tuning range depending on the geometrical dimensions of the midst fiber (MMF and NCF). According to the results, the achieved tuning range due to the diameter fiber changing is higher than that of the length changing. The high tunability about 171 nm is achieved within the SMS cascade for the diameter changes from 61 µm –to– 64 µm and about 340 nm is achieved within the SMS cascade for the length changes from 3.9 mm –to– 4.9 mm. In addition, the increasing in the midst fiber diameter caused a red shift in the peak wavelength of the transmission spectrum. While, the increasing in the fiber length caused a blue shift in the wavelength. The calculated lengths for the NCF show good agreement with results that achieved from the simulation software with a total deviation about 0.46 %. While its about 6.5 % for the MMF, since the cladding refractive index is not considered in the theoretical model.
Design of an Efficient Controller for Steam Generator System
Authors: Alkurawy Lafta E. J. , Ismael Ammar Issa , Mohammed Khalid G. 
Published: February 2021

Abstract
The paper describes the establishment of a boiler control implemented on laws of fundamental physical system, effects of modelling of boiler, data of plant, constant of known physical, and adjustment of heuristic. The objective of this work it to find the modelling of the steam generator and steady the properties of the outputs to find the suitable controller. The model involves the nonlinearity mathematical model, noise of measurement, and time delays. The model represents by state space equations for each variable to describe the whole model system. The model acquired can be utilized for the algorithm for modelled-based control as a simulator of real- time for controlling and operating system. The suggested control for this system will be state feedback control to decrease the peak overshoot for each response of outputs have been seen to maintain the stability and performance.
Reflection and transmission coefficients measurements for polymer composites with a nano-pzt material using a non-resonant method
Authors: Al-Nedawe Basman M. , Ali Israa Hazem , Ahmed Ahmed Mohammed , Mahan Hamid M. 
Published: February 2021

Abstract
The recent significant growth of telecommunications systems, especially in radar applications, has created a sustained need for more smart materials for detecting and/or concealing given objects from radar systems. Key contributing factors in this respect are the reflection and transmission coefficients of such composite materials. The two main methods for calculating the reflection and transmission coefficients are non-resonant and resonant methods. In this work, non-resonant reflection/transmission methods are used to calculate the reflection and transmission coefficients of polymer composites mixed from 1 - 4 wt% of Nano-PZT (Lead Zirconium Titanate). The calculation of the reflection and transmission coefficients is carried out experimentally using an electromagnetic wave on a single layer made from this material. Results show that the transmission coefficient reached a maximum value at 10 GHz, while the reflection coefficient reached a maximum value at 8-9 GHz for all the distance 50-160mm.
Fabrication and Investigation of Bioceramic Scaffolds by a Polymer Sponge Replication Technique
Authors: Mehatlaf Auday A. , Farid Saad B. H. , Atiyah Alaa A. 
Published: February 2021

Abstract
Initially, hydroxyapatite powder was produced using the wet participation method. The x-ray diffraction and particle size analysis were performed after the preparation method of the powder. Using polymer replication technique to produce scaffolds of HAP with structural and physical properties appropriate to human trabecular bone. The microstructure and chemical bonding of the pours scaffolds were investigated by using XRD spectroscopy, scanning electron microscopy (SEM) and Fourier Transform Infrared (FTIR) after the sintering at temperture1300 °C for 2 hours. The synthesized scaffold was soaked in medium of the simulated body fluid (SBF) in order to evaluate bioactivity. From the results, it was observed that the scaffolds were contained open and interconnected pores with porosity range between 72-75 %. In addition, SEM morphology analysis was indicated high bioactivity of pours scaffolds due to the creation of apatite layer on its surfaces were observed after soaking 7days in SBF media.
Thermodynamic analysis with energy recovery comparison of transcritical CO2 heat pump system using various expansion devices.
Authors: Jawad Al-Tameemi Mohammed Ridha , Abed Khuder N , Salem Thamer Khalif , Yu Zhibin 
Published: February 2021

Abstract
The high irreversibility caused by the expansion valve in the conventional transcritical CO2 heat pump cycle has been reported as the major drawback on the overall system performance. To overcome this problem and recover some of the energy lost, different isentropic expansion devices such as turbine expander and two phase ejector have been proposed. This study aims to numerically compare the performance of the transcrtical CO2 heat pump in terms of first and second law of thermodynamics. In addition, the energy recovered by the two phase ejector and the turbine expander cycles have been evaluated. The pressure recovery and entrainment ratio in the ejector device were investigated comprehensively. Two numerical models using MATLAB and ASPEN PLUS software have been developed, and REFPROP database was used to estimate the refrigerant thermophysical properties. The results showed that the heating coefficient of performance (COPh) of the ejector cycle is higher than that of the turbine and valve cycles by 10.15 % and 20.84 % respectively. In addition, the ejector cycle has the highest second law efficiency (0.1) and the recovered energy is (0.63 kW) compared to (0.107 kW) gained by the turbine cycle. The ejector device has the least exergy destruction (0.2 kW) and can recover 0.7 Mpa of the pressure losses.
Drawing the Tensile Curve for Pure Metals and Alloys Depending On Crystal Structure and Acoustic Impedance
Authors: Mohammed Arshed Abdulhamed , Azzawi Wessam Al 
Published: February 2021

AbstractA new method to predict the stress-strain relation of the pure metals and alloys has been presented in this paper by using the acoustic impedance property. The method involves developing new algorithms that were programmed in a MATLAB code. Also, it compromises the experimental measurement of some physical properties, such as longitudinal wave velocity, density, and crystal structure. The study considered 19-samples, which have been put in three different groups depending on the crystal structure (seven FCC samples, six BCC samples, and six HCB samples). The samples’ crystal structure was examined using the X-ray diffraction method before the samples’ density, and longitudinal wave velocity were experimentally measured. To evaluate the validity of the developed model, a comparison between its prediction for the stress-strain relation and the corresponding curves in the literature was done. The results, also, verified the existence of a relation between pressure transmission coefficient (PrTr) and each of the σu, σy, and modulus of elasticity (E) properties for the metals in the same crystal structure group.
Design exploration study of a smart passive window based on NiTi bent actuator
Authors: Alazzawi S , Filip P 
Published: February 2021

Abstract
This paper presents a multi-functional (sensing -actuating) greenhouse ventilation window design heated/cooled naturally by convection, to overcome different industry challenges in terms of designing smart applications. This ventilation window design includes a smart C-shaped NiTi actuator and three-pulley system, and all attached to the window. The force generated in the NiTi wire shrinks the C-shaped to open the ventilation window when the environmental temperature increases. When the environmental temperature decreases, the C-Shaped NiTi actuator returns to its initial position and closes the window. This smart actuation allows energy saving due to natural phase transformation induction (i.e. convection) and high force generation compared to the small NiTi wire mass. Using the pulley system is important as well to reduce the load on the NiTi actuator and enhance its long-life time. In this paper, the smart ventilation window actuator design has been disused followed by a simulation study to investigate the NiTi C-shaped element behavior. The simulation results predict the thermomechanical behavior of the NiTi wire at the proposed greenhouse environmental conditions and the force generated in the wire. For future studies, an experimental investigation could be done to prove the simulation results.
A Critical Review of Subgrade Soil Reinforced with Geo-synthetics
Authors: Oleiwi Ghusoon H , Aodah Haider H , Al-Obaidy Nesreen K , Alomari Kasim 
Published: February 2021

AbstractRecently, the application of geosynthetics in the reinforcement of weak subgrade is expanded dramatically. However, selection of the geo-material that fits site conditions and soil type is crucial to achieving the success of the overall performance of such improvement. Also, the road life and cost construction are significant keys for evaluating this type of ground treatment. This paper presents an overview of the subgrade strengthening with geosynthetics to acquire a better understanding of the technique and to provide a clear guide for transportation and geotechnical engineers. The rutting failure along with its main causes are highlighted briefly. The types of geosynthetics, their applications and functions are also listed. Besides, the effect of soil type and properties on the efficiency of geofabrics-subgrade reinforcement are presented. Moreover, the effectiveness of geosynthetics on the road’s life and construction costs are discussed. Findings of the reviewed studies referred to the contributions of the technique in strengthening the soft subgrade, extending the service road life, reducing the construction cost and reducing the associated rutting deformation. Most studies presented in this paper have proven the efficiency of utilizing geosynthetics in the pavements to minimize the vertical stress in the subgrade under the wheel path. However, the influence was related to the geo-material type and site-specific conditions.