bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic co-pyrolysis palm oil empty fruit bunch and low-density polyethylene of plastic waste into high grade bio-oil
Authors: Sunarno  , Zultiniar  , Santoso A H , Utama P S
Published: February 2021

Bio-oil produced from biomass pyrolysis is still acidic and has a low heating value. Co-pyrolysis is a process of pyrolysis of biomass and material that has a higher (H/C) effective. Low-density polyethylene (LDPE) is a type of plastic waste that has a higher hydrogen index than empty fruit bunch (EFB). To improve the quality of bio-oil, it is necessary to co-pyrolysis EFB and LDPE using a calcium oxide catalyst. The purpose of this research is to produce bio-oil from a mixture of EFB and LDPE, to determine the effect of the CaO catalyst ratio and temperature on the bio-oil yield, and to determine the physical and chemical characteristics of the bio-oil product. The catalytic co-pyrolysis process uses 10 grams of EFB/LDPE mixture (EFB/LDPE ratio 50%:50%), CaO catalyst with a variation of CaO/raw material ratio (1%, 2%, 3%, 4%, and 5% w/w) and temperature variations (400°C, 450°C, 500°C,550 and 600 °C), with nitrogen gas flowing at a flow rate of 400 mL/min for 45 minutes. The highest yield generated on the use of CaO/raw material ratio of 5% w/w and temperature of 550 °C was 35.2%. The characteristics of the bio-oil obtained were the density of 0.948 g/mL, the viscosity of 4.18 cSt, pH of 4.04, and heating value of 43.4 MJ/Kg. The results of GC-MS analysis showed that bio-oil contained 37.05% phenol compounds, 27.88% hydrocarbon, 20.27% ketones, 7.21% alcohol, 4.36% aldehydes, and 1.08% ester.
The Effect of Air Temperature on Drying Rate of Red Cayenne Pepper
Authors: Yusuf Syafza M , Diamantini Yura Amalia , Djaeni Mohamad
Published: February 2021

The red cayenne pepper (red chili), an agriculture crop, is useful for food seasoning. The fresh red pepper popular as red chili contains around 73-75% water. With high water content, the pepper cannot be stored for a long time due to the microorganism and enzymatic activities. The drying is a good option to remove its water content in which improves the storage life. The research studies the effect of drying temperature on the drying rate of the red pepper. Here, the red pepper was put in a tray dryer to be contacted with air at various temperatures ranging from 40°C - 70°C for 180 minutes. As a response, the moisture content in the red pepper was observed and the drying rate, as well as thermal efficiency, were calculated. Research showed that the higher air temperature accelerated the rate of water removal. At operational temperature 70°C, thermal efficiency was the highest. Besides, the moisture content in the pepper was also below 15% in which was favorable for dry pepper storing.
Modeling of Glycerolysis Kinetic of Free Fatty Acid in Crude Palm Oil
Authors: Suriaini N , Raaf A , Arpi N , Syamsuddin Y , Supardan M D
Published: February 2021

Kinetics describing chemical glycerolysis reaction of free fatty acid (FFA) in crude palm oil (CPO) with crude glycerol has been investigated. In this study, the kinetics was explored under the conventional procedure using KOH as a homogenous catalyst. The FFA value was measured by the acid-base titration technique. The effect of FFA to glycerol molar ratio and reaction temperature are examined to determine the best condition for FFA reduction. The glycerolysis achieved a maximum FFA reduction from 6.15% to 0.28% under the following conditions: FFA to glycerol molar ratio of 1:4 and 75°C temperature. Under these conditions, the total reaction orders and the reaction rate constant of glycerolysis were determined by establishing six kinetic models. It was found that the highest R2 was 0.89, which was presented from model 5 (α=2, β=0): ^j = kCAOt. The calculated rate constant, activation energy, and pre-exponential factor were’ 6^5608 L mol-1 min−1, 9,432 cal mol-1, and 5.4x106 L mol-1 min−1, respectively.
The effect of solvent volume ratio and extraction time on the yield of red dye from sappanwood
Authors: Septiani I E , Kumoro A C , Djaeni M
Published: February 2021

Natural red dye from sappanwood (Caesalpinia sappan L) contains brazilin that can be used as an antioxidant source. The dye can be isolated by extraction using a polar solvent such as distilled water. The more water was added, the more extract can be obtained. However, the process cannot be straightforward since the excessive solvent consumes more energy cost in the extract product purification. The study aims to investigate the effect of water to sappanwood ratio and operational time on the effective time for the extraction of red dye from sappanwood assisted by ultrasound vibration. Here, the water to sappanwood ratios were varied from 5:1 to 8:1 at operational temperatures 60°C. With more excessive solvent, the yield of sappanwood extract increased. For example, at 60°C and solvent to sappanwood ratio 8:1, the process yielded 4.0% extract for 15 minutes. Compared to the literature with conventional extraction without ultrasound, this achievement was twofold. Lowering solvent to sappanwood ratio reduced the extract yield, but it will ease in product separation. Furthermore, extending extraction time increased the yield, but after 15 minutes the effect was limited.
Experimental Investigations of Partial Replacement of OPC with PFA and GGBS in cement mortar
Authors: Quraya Abdullah Bin , Al-Ameeri Abbas , Hashim Raad , Yeboah David , Shubbar Ali , AL-Hayawi Anas Y. , Al-Jumeily Dhiya , Mustafina Jamila
Published: February 2021

Production of cement has been identified as a major source of carbon dioxide, particulates, and other gases, where it was reported that the production of one ton of OPC could produce one ton of CO2. These gases and particulates exert significant effects on human health and the environment. Therefore, the supplementary cementitious materials (SCMs) are becoming sustainable concrete in comparison with ordinary Portland cement (OPC) by decreasing the consumption of cement and carbon dioxide emissions. This experimental study is to focus on the effect of partial replacement in cement by pulverized fly ash (PFA) and ground granulated blast furnace slag (GGBS). Four mixes were used with different values of PFA and GGBS and they tested at 1, 2, and 4 weeks. The compressive strength of these specimens was carried out by a compression test. The test results revealed that increasing the ratios of PFA and GGBS replacement results in a decrease in the compressive strength of specimens. The decrease in compressive strength of SCMs mortar ranged from 20 to 30%, and they could be an acceptable value.
An experimental study for adapting electrocoagulation as a technique for fluoride removal from water
Authors: Aayef Ali Naser , Mahdi Al Masoodi Wasim T. , Kamel Ruaa Jameel , Abdulredha M , Almansoori Nayef A. , Kot Patryk , Muradov Magomed
Published: February 2021

A small amount of fluoride in potable water can maximize teeth mineralization and minimizes their cavities. However, fluoride presence in excess quantities in drinking water could cause severe illnesses including Alzheimer’s syndrome and women infertility. Thus, scholars are concerned over the last decades in developing techniques to minimizes the concentration of fluoride from wastewater and lower its impact on human health. The current research aims to utilize the electrocoagulation technique to remove the fluoride from wastewater. Experiments were conducted to study fluoride removal using rectangular electrocoagulation cell and analyze the influence of four main parameters namely detention duration, electrodes spacing, pH and current density on the performance of the electrocoagulation techniques on fluoride removal. The results showed that 93% of the fluoride was removed from the wastewater after 20 minutes of treatment using 5mm electrodes spacing with a current density of 2 mA/cm2 at a pH level of 7. The main parameters have a significant influence on the removal efficiency of the fluoride. A higher fluoride removal efficiency can be achieved in the acidic setting. The removal efficiency is positively related to the electrical current and the detention time while it is negatively related to the electrode spacing.
Dye removal from textile wastewater using solar-powered electrocoagulation reactor
Authors: Jawad Sabrean Farhan , Saddam Nahlah Salman , Adaami Qasim J. , Kareem Mohanad M. , Abdulredha M , Mubarak Hayfaa A. , Kot Patry , Gkantou Michaela , AlKhayyat Ahmed
Published: February 2021

A wide range of methods is currently used to remove various pollutants from wastewater. The current focus of research and industries is the use of electrocoagulation for wastewater treatment as this technique can be run using solar energy which produces in-site coagulant able remove dissolved and suspended pollutants at a short time and low cost. Dyes are currently categorised as a universal surface water pollution problem since many industries produce dyes polluted wastewater such as the textile industry. The current investigation focus on the use of electrocoagulation to treat acid orange 2 dye polluted synthetic wastewater and study the impact of the experimental parameters. An electrocoagulation reactor was developed using Iron electrodes and the energy was provided to the reactor using a solar panel. It was found that 100% of the pollutant was removed using electrocoagulation reactor runs on solar power. The Neutral pH level is favourable to remove the dye from textile wastewater. Higher current density and smaller distance between electrodes provide higher removal efficiency of the dye. Generally, it could be said that the best removal of the dye was achieved at pH level at 7, the current density at 2 mA/cm2, the spacing at 5 mm, and the treatment time at 40 minutes.
Agro-based carbon for lead removal from solutions
Authors: Naser Salam M. , Ali Sarah A. , Alkizwini Rasha S. , Alshamali Mohammad , Alquzweeni Saif S. , Abdellatif Mawada , Amoako-Attah Joseph , AlKhayyat Ahmed
Published: February 2021

The current study utilizes the carbon derived from the lemon peel (CLP) as an adsorbent to remove Pb (II) ions from solutions. Activation of the lemon peels was carried out by adding 1 part of the lemon peels to 1.8 parts of concentrated sulphuric acid, and well-mixed before heating the mixture at a temperature of 150 °C for 24 hours. The produced material, CLP, was employed for lead adsorption from water. A number of parameters namely, treatment times, pH, and doses of CLP were studied to assess their influence on the removability of Pb (II) by the CLP. The results indicated that the optimum contact time, pH, and dosage values for the best removal of lead were 80 min, 5, and 3 g/L respectively. To analyze the observed data gained from batch equilibrium tests, isotherm models (Freundlich and Langmuir), kinetic models (the pseudo-first-order, and the pseudo-second-order), and inter-particle diffusion using non-linear regression techniques were applied for this purpose. The obtained results proved that the equilibrium data have reasonable and good fitness and correspondence with the Freundlich isotherm models. The highest adsorption capacity and the highest removal percentage for Pb (II) were 32.98 mg/g and 99% respectively at ambient temperature.
Agri-food wastes for heavy metals removal from water
Authors: Talebi Zainab Abbas Al , Abbas Sahar F. , Alkizwini Rasha S. , Alazemi Saud , Alquzweeni Saif S. , Kot Patryk , Muradov Magomed , AlKhayyat Ahmed H.
Published: February 2021

The current study explores the possibility of using granular activated carbon derived from wasted coconut shell (CCS) as a bio adsorbent to purify aqueous solution from Al(II) ions. A number of different parameters including treatment time, pH, and dosage of adsorbent (CCS) were tested to assess their influence on the Al(II) removability. The optimum conditions for best removal were contact time of 90 min, pH of 7, and a dosage of 1 g/L. Freundlich and Langmuir isotherm models and kinetic models including the pseudo-first-order, the pseudo-second-order, and interparticle diffusion were employed to analyse the observed data which were gained from batch equilibrium tests using nonlinear regression methods. The obtained results revealed that the equilibrium data have good and reasonable fitness and correspondence with the Langmuir isotherm models. The maximum adsorption capacity for CCS and the maximum Al(II) removability were 120.6801335 mg/g and about 100%, respectively, at ambient temperature.
Study the performance of three-phase induction motor under imbalanced non-sinusoidal supply
Authors: Jassim Abdulsatar H. , Hussein Arkan A. , Abbas Laith F.
Published: February 2021

The rising of single-phase distributed generators and imbalanced loads in the electrical power grid can cause the three phases voltage to unbalance, causing in risen losses and overheating in motors. As a consequence of the growing usage of electronic equipment and non-linear load, the waveform of the voltage source of the electrical system is becoming distorted and variations appear among the phases. This work explores the negative impacts of imbalanced of 10 HP three phase induction motor squirrel-cage fed by three phase IGBT inverter at full load. The drive system has been designed and simulated by MATLAB/Simulink. The inverter switches are controlled by a pulse controller, which consists of two level pulse width modulation (PWM). The results represent the effects on the performance of the motor. The results of the Simulation show the negative impacts of imbalanced non-sinusoidal voltages which are higher than the case of balanced non-sinusoidal voltages. Also, the computation of voltage unbalance factor (VUF) depending on positive and negative sequence components are considered.
An encryption based on DNA and AES algorithms for hiding a compressed text in colored Image
Authors: Alsaffar Qusay S. , Mohaisen Hatem N. , Almashhdini Firas N.
Published: February 2021

The vast serious security challenges has created new secured ways of transmitting information and reduce the chance of hackers to use their methods to analyse the confidential information between two parties. The research combines between several stages of encryption techniques: DNA encryption algorithm, GZIP algorithm, AES cryptography and image steganography. We proposed multiplying by a factor along the last stage of DNA encryption, and the outputs of this process are compressed using the GZIP algorithm, where the message is converted to a new form and its size reduced to (75%), then after the message is encrypted using the AES encryption algorithm to increase the level of security. Furthermore, LSB image Steganography technology is utilized to hide the encrypted message in a high-quality image. By combining these four security technologies we obtained good results for image measures such that Lina sample provided (PSNR is equal 67.589, MSE is equal 0.0116, SSIM is equal 1, NPCR score is 0.011630262741374 and UACI score is 4.5608873495583733e-05) and we ensure transferring data without gaps & make it difficult and more complex for the hacker.
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

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

The 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

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

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

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

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

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

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

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

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

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

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

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

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

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

A 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

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

Recently, 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.
Comparative Study of Structural Behaviour of Reinforced Concrete Box Girder with Different Numbers of Cells
Authors: Zuhdiy Zahraa Sermed , Abbas Ali Laftah
Published: February 2021

The aim of this research is to study the experimental effect of the number of cells on the structural behaviour of reinforced concrete box girder. Three simply supported box girder specimens with different numbers of cells were cast by using self-compacting concrete and experimentally tested under four-point load, the first reference specimen is with one cell, the second specimen is with two cells and the last specimen is with four cells. The testing results show that the ultimate load in the two-cell and four-cell specimens is higher compared with the one-cell specimen by (20.1% and 23.3%) respectively. Increasing the number of cells decrease the cracks width and increase the number of cracks, all the specimens failed with diagonal shear.
Adoption PPP model as an alternative method of government for funding abandoned construction projects in Iraq
Authors: Khudhaire Huda Yaseen , Naji Hafeth I.
Published: February 2021

The Iraqi construction sector is facing complex issues and a number of problems. Abandoned construction projects are considered one of the most common and serious problems in the construction industry in Iraq due to a lack of funding, which reflected by exceeding the time limit for completion of the projects. The number and value of the projects involved are usually large. reconstruction, maintenance, and operation of unfinished projects in Iraq require better coordination between these issues, and the country’s other affairs, this goal, cannot be accomplished unless the project is financing in the most successful way. This study aims to use the analytic hierarchy process (AHP)technique to select the appropriate type of the Public-Private Partnership (PPP) contracts to finance abandoned projects in Iraq. using a questionnaire survey to select the most significant criteria for choosing an appropriate financing approach for the abandoned project. The reliability of the questionnaire is achieved, by using the Cronbach Alpha calculated by SPSS software (Version 26). The results obtained illustrate the final weight of the Build, Operate and Transfer (BOT) contract from AHP is 0.261 is the best type of the (PPP) contracts in the alternatives suggested to finance the project.
Diagnosing the Causes of Poor Quality Management in Iraqi Construction Projects Using Technique of Root Cause Analysis
Authors: Jasim Nidal Adnan
Published: February 2021

The objective of this research is to classify and diagnose the causes of poor quality management in Iraqi construction projects. This study diagnosed fifty-three causes of poor quality management in Iraqi construction Projects. which they divided into eight main groups (Equipment causes, Labors causes, Systems causes, Materials causes, Design and Execution causes, Subcontractors causes, Site staff causes, Contract causes). Then calculated the relative importance of the causes of poor quality management in Iraqi construction projects. Three techniques were used in this study: Ishikawa diagrams, Pareto diagrams, and 5-why techniques. Pareto analysis showed that thirty-six causes out of fifty-three causes represent the most important causes of poor Quality Management, these causes had been filtered by 5-Why analysis. The most important causes were failure to comply with laws and standards and poor compliance to specification, as identified in contract conditions within design and execution causes group, followed by low skill and experience of Contractor’s staff within Site staff causes group and failure to implement a quality control and assurance system within systems causes group.
Dissolved Oxygen Sag Curve for Diyala River at Baquba City
Authors: Abbas Muhanad Mohammed
Published: February 2021

The water pollution is one of the major environmental problems that which suffered in rivers at Diyala governorate when the untreated waste or partially treated is disposed to rivers. In this study the effect of five sources of raw waste water distributed along Diyala River on the dissolved oxygen sag curve behavior was investigated for selected reach of river when passing Baquba city in Iraq. Dissolved oxygen sag curve tested by using Streeter and Phelps model during summer season Jun, 2018. The study results showed that there was an accumulative effect by decreasing in dissolved oxygen due to these five sources. The dissolved oxygen in the river being below 4 mg/L after the fifth source and continues for (99.4 Km) distance, this point located before river mouth with Tigris River by about 3.4 Km. Dissolved oxygen declined to its critical value after 45Km from first source with maximum deficit. According to the model calculation, Diyala River decants in Tigris River with low limit of dissolved oxygen by about 4.1 mg/L if there were no another sources downstream the observed sources and before achieving its self purification required distance. Also, biochemical oxygen demand was greater than 4 mg/L before river meeting the sources and increased gradually to be greater than 10 mg/L after the fifth source and the temperature increased by about 4 °C.
Integrity of Revit with structural analysis softwares
Authors: Hadi A S , Abd A M , Mahmood Mohammed
Published: February 2021

This paper investigates how the utilize of Building Information Modeling (BIM) can be a useful platform for engineers. The interlinking of Revit with structural analysis software like Robot Structural Analysis and Etabs is evaluated. A case study was taken considering a multi-story reinforced concrete building. It was modelled in Revit and analyzed and design in Robot Structural Analysis and Etabs software. The difference in results of design between traditional methods and using BIM methods is discussed. Also, extract documentations from the same model. This study highlighted powerful of BIM technology for structural engineers in terms of analysis, design and documentation process.
A Comprehensive Study of Franki pile with the other pile models Embedded within cohesionless soils
Authors: Mahmood Mahmood R. , Muhsin Makki K. , Abbas Ahmed M.
Published: February 2021

Frankie pile is classified as a large displacement pile cast in place with a concrete mixture. This paper dealt with the laboratory work to produce a model of the Franki pile similar to the full-scale production process in the field to investigate its behaviour and make a comparison study with the other familiar types of piles models (precast concrete pile, closed-ended steel pipe pile, and bored pile with the same surface and cross-sectional area). The investigation occurred within dry sandy soil with two different relative densities (30 and 60) % will be denoted as (S1) and (S2) respectively. Axial compressive piles load tests were performed for embedded piles models in sandy soils at relative densities of 30% and 60%. Several interpretations have been used to estimate the ultimate capacity of pile models from the results of pile load tests. It was found that the Davisson, De Beer, Fuller and Hoy, and Tangent Methods gives an approximate acceptable result for all typical pile load tests, so average values of theses methods were adopted for comparisons. It was observed that the ultimate bearing load value at a Franki pile was greater than the other types of piles models in both densities. The for precast concrete pile, 2.98 for close ended pipe pile and 5.5 for bored piles for low relative density. While for high relative density the bearing ratio of Franki pile over other pile models were 0.94 for precast concrete pile, 2.26 for pipe pile model and 3.16 for bored pile model. During this study, it was found that a Franki pile was more effective in weak granular soils.
Mosul Dam between the threats of imminent collapse
Authors: Abdul Hameed Maha Rasheed , Abbas Ali Laftah
Published: February 2021

This research deals with the state of Mosul Dam since first filling of the reservoir, studying the salt measurements and quantity of grouting materials consumption against drilling bore holes lengths. Based on those measurements, the conclusion made that, the state of the dam had been passed prior periods more dangerous cases than it is now, specially before fixing 319m level as threshold level in which the Reservoir level not admitted it be higher. The conclusion made that the state of the dam currently is not the worst case as claimed by USA side the research also explained the most important methods of maintenance and controlling which needs to follow according to design and guidance of treatment. The most important conclusion that this research raise is the necessity of construction of the Diaphragm Wall as a permanent solution which can be considered as a unique solution to solve the Mosul Dam problems permanently.