bluuebunny/crossref_metadata_2025 huggingface dataset:
Plasmonic gratings from highly doped Ge1−y
Sn
y
films on Si
Authors: Berkmann Fritz , Ayasse Markus , Schlipf Jon , Mörz Florian , Weißhaupt David , Oehme Michael , Prucnal Slawomir , Kawaguchi Yuma , Schwarz Daniel , Fischer Inga Anita , Schulze Jörg
Published: August 2021

Plasmonic modes in metal structures are of great interest for optical applications. While metals such as Au and Ag are highly suitable for such applications at visible wavelengths, their high Drude losses limit their usefulness at mid-infrared wavelengths. Highly n-doped Ge1−y
Sn
y
alloys are interesting possible alternative materials for plasmonic applications in this wavelength range. Here, we investigate the use of highly n-doped Ge1−y
Sn
y
films grown directly on Si by molecular beam epitaxy with varying Sn-content from 0% up to 7.6% for plasmonic grating structures. We compare plasma wavelengths and relaxation times obtained from electrical and optical characterization. While theoretical considerations indicate that the decreasing effective mass with increasing Sn content in Ge1−y
Sn
y
films could improve performance for plasmonic applications, our optical characterization results show that the utilization of Ge1−y
Sn
y
films grown directly on Si is only beneficial if material quality can be improved.
A stiffness compensated piezoelectric energy harvester for low-frequency excitation
Authors: van de Wetering E , Blad T W A , van Ostayen R A J
Published: August 2021

In this work, a stiffness compensated piezoelectric vibration energy harvester is modelled and tested for low-frequency excitations and large input amplitudes. Attracting magnets are used to introduce a negative stiffness that counteracts the stiffness of the piezoelectric beam. This results into a nearly statically balanced condition and makes the harvester a nonresonant device. A distributed parameter model based on modal analysis is used to model the output of the energy harvester. This model is extended by including the negative stiffness, endstop mechanics and force-displacement data to the model. The peak RMS power amounts 1.20 mW at 9 Hz and 3 g input acceleration. These are large inputs and serve to illustrate the case of having inputs larger than the device length. Furthermore, to benchmark the energy harvester in this work, the efficiency is evaluated in terms of generator figure of merit and is compared to prior art. This peak efficiency amounts to 0.567%, which is relatively large for its range of excitation. From the output that has been obtained with this design, it can be concluded that stiffness compensation can make a piezoelectric energy harvester competitive in terms of generator figure of merit at low-frequency excitation with input amplitudes exceeding the device length.
Constraints on the properties of warm dark matter using the satellite galaxies of the Milky Way
Authors: Newton Oliver , Leo Matteo , Cautun Marius , Jenkins Adrian , Frenk Carlos S. , Lovell Mark R. , Helly John C. , Benson Andrew J. , Cole Shaun
Published: August 2021

The satellite galaxies of the Milky Way (MW) are effective probes of the underlying dark matter (DM) substructure, which is sensitive to the nature of the DM particle. In particular, a class of DM models have a power spectrum cut-off on the mass scale of dwarf galaxies and thus predict only small numbers of substructures below the cut-off mass. This makes the MW satellite system appealing to constrain the DM properties: feasible models must produce enough substructure to host the number of observed Galactic satellites. Here, we compare theoretical predictions of the abundance of DM substructure in thermal relic warm DM (WDM) models with estimates of the total satellite population of the MW. This produces conservative robust lower limits on the allowed mass, m
th, of the thermal relic WDM particle. As the abundance of satellite galaxies depends on the MW halo mass, we marginalize over the corresponding uncertainties and rule out m
th ≤ 2.02 keV at 95 percent confidence independently of assumptions about galaxy formation processes. Modelling some of these — in particular, the effect of reionization, which suppresses the formation of dwarf galaxies — strengthens our constraints on the DM properties and excludes models with m
th ≤ 2.02 keV in our fiducial model. We also find that thermal relic models cannot produce enough satellites if the MW halo mass is M
200 ≤ 0.6 × 1012
M
☉, which imposes a lower limit on the MW halo mass in CDM. We address several observational and theoretical uncertainties and discuss how improvements in these will strengthen the DM mass constraints.
Performance Analysis and Comparison of narrowband noise passing through filter types (Elliptic) and (Butterworth)
Authors: Mahdi Khafaga Ali. S.
Published: August 2021

This paper introduces the properties of an elliptical filter and Butterworth filter characteristics when narrowband noise passes through them, which has the same behavior in both, traffic and stop range. The amount of ripple in each band can be adjusted independently as it has a faster gain transition between the pass and stop band, so a compression has been made between elliptical and Butterworth filters response to narrowband noise in order to find a new ways to increase their immunity to noise. MATLAB Simulink Software has been used as a simulations environment.
Laser Transmission Welding is a promising joining technology technique – A Recent Review
Authors: Khayoon Marwa A. , Hubeatir Kadhim A. , Al-Khafaji Mohanned M.
Published: August 2021

Laser transmission welding (LTW) is one of the latest evolutions in joining technology. Simply, it involves joining two similar or dissimilar materials by melting and fusing two parts at their interface using laser radiation. The upper material is transparent in order to allow the laser radiation to pass and heat the second material which is in this case an absorbent material. This technique is also known with other names such as Laser Plastic Welding, Through-Transmission Welding and Laser Assisted Metal to Polymer Joining. The developments occurred in this field have also enabled LTW to approach different Lasers like Diode Laser, CO2Laser, Nd: YAG Laser and Fiber Laser. This review aims to explain LTW process, working procedures, effect of Laser types and process parameters on this approach. It especially clarifies using LTW to weld thermoplastics materials together or with metals. It also attempts to help scholars to have an overview on LTW technique and achieve their answers related to this topic.
Remove Skin Deformities by Using CO2 and Nd:Yag Laser
Authors: Lefta Sadiq Hassan , Jaraa Ihsan , Hadi Ghufran
Published: August 2021

The treatment of some skin damage have been studied influence the laser beam CO2 and the Nd:Yag with wavelengths (10600nm and 1064 nm) respectively as foundation of radiation. The current research aims to verify effect of altered laser dosages of the skin in an attempt to recognize how the laser achieves medicinal effects to treat skin lesions. And the aims to establish the correlation between laser dose and biological influence and so after that calculate its low dose with higher medical influence and minimal harm to. The number of cases included four different diseases, ranging between 18-50 years. Areas of the body were exposed to laser beams and different wavelengths by type laser user. The first case, represent the image of a girl suffering from autoimmune disease, Nd:YAG laser was used with Q-swtich Nd: YAG to treat this condition and the wavelength is 1064 nm, second case, image of a person suffering from the impact. Fractional Co2 Laser and wavelength 10600 nm where used and third case: An image of a person suffering from costs, treatment by using Q-switch Nd-YAG laser short pulse has a wavelength of 1064nm.
Fresh Water Generator: A Review
Authors: Muhammed Haneen Q. , Khalifa Muhannad Z. , Owaid Abdul J.
Published: August 2021

This search presents a study for some types of fresh water generators FWGs, giving an overview of each type and comparing them with other types, and knowing the design criteria for different designs, as well as studying their advantages and disadvantages, including thermal desalting which types are vapor compression (VC), multi stage flash distillation (MSF), multiple effect distillation (MED), and multiple effecte evaporator, adsorption desalination, membrane distillation (MD), freezing desalination, and hydrate desalination. Then we studied the non-thermal desalination process, which includes electro-dialysis (ED), ion exchange desalination (IX), extraction desalination process, and additional types of fresh water generators FWGs.
Evaluation of the hospital’s wastewater treatment plant in basrah province
Authors: Al-Khafaji Samar A. , Al-Rekabi Wisam S.
Published: August 2021

This paper concentrates on evaluating the wastewater properties and performance of the hospital wastewater treatment plant (WWTP) for two hospitals in Basrah province Al-Taaleme hospital, and Al-Fayhaa hospital. Samples were collected from the WWTS influent and effluent then evaluated pollutants containing by using American Public Health Association (APHA) methods and in comparison to standard guidelines. Laboratory tests of wastewater were conducted to investigate ten parameters: chemical oxygen demand (COD), biochemical oxygen demand (BOD), PH, temperature, electric conductivity (E.C), total suspended solids (T.S.S), total dissolved solids (T.D.S), dissolved oxygen (DO) sulfate (SO4), phosphate (PO4), ammonia (NH3) and nitrate (NO3) which have been chosen to assess the quality of wastewater. The results showed that all pollutants were in compliance with the standard limit in Iraqi standard specification B1 for the year 1998, except for the NH3 results for Al-Fayhaa hospital (B), which were 12 mg/L while the standard was 10 mg/L, and COD effluent was exceeded the Iraqi standards for both hospitals Al-Taalemee hospital (A) and Al-Fayhaa hospital (B), which were 155 mg/L and 150 mg/L respectively while the standard was specified effluent by 100 mg/L, and for SO4 effluent was exceeded the Iraqi standards for both hospitals Al-Taalemee hospital (A) and Al-Fayhaa hospital (B) was 760 mg/L and 650 mg/L respectively while the standards were specified by 400 mg/L.
Comparative Analysis of Two Alloys (GTD-111 and IN-738) used in Blade of Gas Turbine Model MS9001E at South Baghdad Station
Authors: Abdulah Alaa Jasim , Khalifa Muhannad Z. , Owaid Abdul Jabbar
Published: August 2021

Blades are one of the basic components of a gas turbine and its main function is to rotate the shaft associated with the generator motor. Gas turbine model MS9001E used power plants at south Baghdad station, the blades are subjected to harsh working conditions such as high vibration, temperatures and pressures, thus highlighting the importance of studying the materials used in Manufacture of blades that work under harsh operating conditions. In this research, stress, strain and deformation produced by the centrifugal force that the blade is subjected to be studied, as well as studying the natural frequencies of the blades. Three-dimensional was created through the program solidwork 2018 and then exported to the program ansys 2019 for analyzing. Two alloys of materials (GTD-111) and (IN-738) were analyzed and compared between them, and the results showed that alloy (GTD-11) is the best and is suitable for use in the manufacture of blades.
Study the effect of changing voltages values on MRR in the cutting process of electrical discharge machining
Authors: Aghdeab Shukry H , Abdulnabi Anwer Q
Published: August 2021

Electric discharge machining (EDM) is one of thermo-electric, non-conventional machining process. By EDM process can be machining of hard conductive materials which is complicated to machine by traditional machining, complicated shapes, with micro or macro removal rate. Each cutting process was controlled by several parameters, from that’s a voltages values. The aim of this work was study the effect of changing these values on material removal rate (MRR) of AISI 444 stainless steel. The EDM parameters were used in this study are voltage (140, 240) V, current Ip (12, 24, 50) A, pulse on time Ton (100, 200, 400) μs, and pulse off time Toff (3, 6.5, 12) μs. For the design of experiments, the full factorial was used to analysis the result on Minilab 19 software. The results show the (MRR) was increasing with increasing in voltage. Maximum (MRR) that be achieved is (144.2308) mm3/min at higher value of voltage, current and pulse on time.
Estimation the Performance of Gas Turbine Power Station with Air Cooling Fog System
Authors: Sh.Alnasur Fawzi , Al-Furaiji Mushtaq A.
Published: August 2021

The purpose of this study is to shed light on the fog system to cool the inside air to the compressor in the gas station to generate electricity. Where it mainly focused on the suitability of the fog system to the hot Iraqi climate throughout the summer period, a simulation analysis of the operation of the gas turbine unit using a fog system at an ambient temperature in the range of 25-55 °C was conducted in the southern Baghdad second station. The fog system proved to be highly effective in raising the effective power, the thermal efficiency and the effective efficiency coefficient of the gas turbine unit as well as a apparent decrease in the specific air flow rate, the specific fuel consumption and the specific heat consumption in the gas turbine unit compared to not using fog system for cooling and for the same operating conditions.
The effect of first generation biofuel on emission characteristics under variable conditions of engine speeds and loads in diesel engine
Authors: Fayad Mohammed A. , Chaichan Miqdam T. , Dhahad Hayder A.
Published: August 2021

Iraqi sunflower was used in the current study and blended with diesel fuel into different ratios. The results indicated that lowest level of gaseous emissions (CO, HC, and CO2) and PM produced from B100 compared with other fuels tests. Furthermore, the CO and unburnt HC decreased with high conditions of engine loads and speeds. The high concentration of NOX emissions was found from the combustion of B100, B50, and B20 compared with diesel fuel. The emissions of NOX and exhaust gas temperature improved from increasing the operating conditions of engine loads and speeds. The effect of biodiesel blends on the gaseous emissions and particulate matter (PM) was investigated under variable engine operating conditions of loads and speeds. The best reduction was achieved with medium conditions of engine loads and speeds compared with low and high loads and speeds for all fuels tests. The higher oxidation rate of soot particles inside combustion cycle from the burning of B100, B50, and B20 decreased the total concentration of PM.
Building and validation of a low-cost driving simulator
Authors: Khadeir A M , Saehood Z A , Mutar H S , Abduljabbar A S , Al-Dahwi A M , Abdulameer R H , Mohammed A A
Published: August 2021

This study presents the design and manufacture of a low-cost driving simulator device that achieves results comparable to advanced simulation devices with a high cost. The aim is to use it in a variety of laboratory studies to understand the behaviour and performance of the driver and vehicle and in designing the elements of the road infrastructure and using it as a driving training device. (51) participants of both genders and of different ages participated in the performance of driving experiences in the city environment scenario, where the experiment lasted (30) minutes for the purpose of evaluating the validity of the manufactured simulator by filling out a questionnaire consisting of (9) questions. The results indicate that all participants (100%) were impressed with the design of the device, the ease of use of the device’s controls (steering wheel, gearbox and pedals) and the realism of the approved driving simulation program, and by (52.9%) the simulated experience was very good. With a percentage of (96.1%), they evaluated the device between the device being (realistic - very realistic) (100%), and the participants evaluated the device on a scale of (0-100). The summary of the results is that the device has a high acceptance.
Influence of Alumina and Zinc OxideNanoparticles on The Tensile, Impact and Hardness Properties of Epoxy Nanocomposites
Authors: Al-Mansoori Raad Obaid. , Diwan Abbas Ali , Taher Ahmed A.
Published: August 2021

The present work investigates the effect of addition different concentration of nano Alumina (Al2O3) and nano zinc oxide (Zno) by (1%, 3%, 5%) weight fraction with epoxy as the matrix on the tensile, impact and hardness properties. Preparing the samples by using hand lay-up technique, magnatic sterrier, vacuum chamber and ultra-sonication method. The results show that there are increases in tensile strength and impact toughness at 3% Al2O3 nanoparticles (21%) and (189%) respectively compare to pure epoxy. Due to adding 3% Zno nanoparticles there are increase in tensile strength by (21%) and increase impact strength (28%) compare to pure epoxy. In addition, the hardness improved slightly when increase nanoparticles materials of both components.
Investigation of the Axial Forming Force during Low Frequency Vibration Assisted SPIF.
Authors: Nema Reham Ali , Sadoon Muthanna Hamzah , Tawfik Mauwafak Ali
Published: August 2021

Applied low frequency vibration in a single point incremental forming technique has recently been used. Through process of the Single-Point Incremental Forming (SPIF), the precision was affected by forming force and can cause sheet metal fracture. The magnitude of the forming forces is necessary for designing suitable models for the metal forming of the Incremental Layer. Using vibration with various values of frequency (20, 40, 60, 80, 100) Hz with amplitude (0.1mm) can decrease the forming force. It is established that the reduction rate in axial force is about (11.63%) at the frequency of (100 Hz), it is the lowest for the selection of frequencies introduced. The experimental force result has been compared with analytical solution
Design Pipeline Architecture with Fuzzy Logic
Authors: Hassan A F , Hassan Q F
Published: August 2021

This paper aims to design the pipeline who is considered a set of related data processing elements in a series where the result of one element is the introduction of the next one, and it can be used to increase performance and speed at the same time, and we use it in computer systems or home appliances. Increasing the voltage in the pipeline increases the power. When the clock frequency increases to increase the performance of the pipeline, the power increases but at the same time the possibility of an error increases. System errors will lead to a wasted in energy consumption which in turn reduces system efficiency. The problem is how to reduce the power in the pipeline system without effecting the process speed or frequency so that we mention the same throughput with this power. We will deal with N bit full adder and study the effect of increasing these bits on both the time delay and the power consumption of the pipeline gate, and the results show that there is a direct relationship between the number of bits and the power. The razor circuit is used with the pipeline so that the errors that will occur in the pipeline will be detected and corrected within one clock cycle instead of wasting the time and energy on incorrect data, thus the power consumption will be reduced. By introducing a Fuzzy logic controller to the pipeline, it was possible to minimize the power consumption of the system by monitoring the number of bit errors and the consumed power. Also, we will make a comparison of the pipeline when using the controller and when not in use, and we will notice the effect of the controller in reducing the power consumption of the pipeline.
EEG Motor-Imagery BCI System Based on Maximum Overlap Discrete Wavelet Transform (MODWT) and cubic SVM
Authors: Abdulwahab Samaa S. , Khleaf Hussain K. , Jassim Manal H.
Published: August 2021

Communication of the human brain with the surroundings became reality by using Brain- Computer Interface (BCI) based mechanism. Electroencephalography (EEG) being the non-invasive method has become popular for interaction with the brain. Traditionally, the devices were used for clinical applications to detect various brain diseases but with the advancement in technologies, companies like Emotiv, NeuoSky are coming up with low cost, easily portable EEG based consumer graded devices that can be used in various application domains like gaming, education etc as these devices are comfortable to wear also. This paper reviews the fields where the EEG has shown its impact and the way it has proved useful for individuals with severe motor disorder, rehabilitation and has become a means of communication to the real world. This paper investigates the use of Cubic SVM algorithm In the EEG classification. EEG feature extraction is Implemented by maximum overlap discrete wavelet transform (MODWT) to reduce the dimensionality of data. The Sliding Window Technique is used to calculate the mean within each window samples. The feature vectors are loaded into the support vector machine (SVM) and optimize tree.
Experimental Investigation of a Window Solar Air Collector with Circular-Perforated Moveable Absorber Plates
Authors: Dawood Norhan I , Jalil Jalal M , Ahmed Majida K
Published: August 2021

Window solar air collector is a significant instrument for heating residential buildings in cold regions. This paper presents an experimental investigation of the thermal performance of a window solar air collector with seven moveable absorber plates, as each plate contains 28 circular perforations. The 7 plates opened and closed at different angles in unison manually by a specific mechanical mechanism. The effect of changing the plate angles have been tested, alongside the effect of mass flow rates and the intensity of solar radiation. Experimental results shows that the highest air temperature difference is gained at vertical plates position (angle 0°) at mass flow rate 0.0097 kg/s and irradiance 730 W/m2, and the maximum thermal efficiency were 71% at mass flow rate 0.0224 kg/s. In addition, the temperature difference between inlet and outlet air has increased by 24% in case of angle 0 than in angle 45°. In contrast, a flexibility between sunlight penetrating into the room and hot air from the collector will be gained when the plates set on angle 45°.
Experimental Study of Double Pass water passage in Evacuated Tube with Parabolic Trough Collector
Authors: Bassem Sarah , Jalil Jalal M. , Ismael Samer Jaffer
Published: August 2021

In this paper, a new design, fabricate and investigate the performance of the parabolic trough systems (PTC) by using double pass water passage in evacuated tube technology. This system can be used for heating water in winter season without assistive devices. The double-pass method utilizing to improve thermal performance for PTC by increasing the path of water flow in the evacuated tube and then increase the rate of the outlet temperature. Besides, the evacuated tube was used to decrease the thermal losses, which is caused an increase in thermal efficiency. The experiments were test and simulate the different solar radiation approximate to winter season and at many flow rates 0.00305, 0.0055 and 0.0083 kg/s. The higher temperature difference was 46 ° C at minimum mass flow rate 0.00305 kg/s. The maximum thermal efficiency was 69.7 % at 0.0083 kg/s.
Multiple transceivers based wimax mesh network to optimize routing algorithm
Authors: Hamza Bashar J. , Yousif Thanaa Hasan
Published: August 2021

The Base Station (BS) is a WiMAX (Worldwide Interoperability for Microwave Access) centralized scheduling mesh topology decision maker for scheduling the whole network including allocation of packets between the Subscribers (SSs) in the network through the BS. Hence, the system, which, by interference, especially affects the nodes, close to BS. A network routing algorithm was built for mesh topology named Energy Bit Minimum Routing (EBMR), which is used to optimize the chosen path. all nodes were fitted with a multi-channel and four scenarios were planned: the first scenario is called the Multi-Transceiver fitted both SSs with a multi-transceiver except at the brink without cap the number of parent nodes. Whereas the second scenario was called Closest Multi-Transceiver system no ceiling on the number of parent nodes, in this scenario only the nearest BS is fitted with multi-transceiver SSs. The third scenario used the Multi-Transceiver system but with cap the number of parent nodes by 30% for whole nodes network. The fourth scenario used the closest Multi-Transceiver system but with cap, the number of parent nodes by 30%, for whole nodes network. In scenarios, the system content considers 120 users as maximum. It will improve the network capacity, throughput, channel scheduling range and channel utilization ratio (CUR). WiMAX mesh topology is used to centralize scheduling and improve the performance system by finding the best route to centralizing the mesh network EBMR; consequently, it increases latency, CUR and distance scheduling, avoiding messing, otherwise. Multi-transceiver network is used to prevent primary interference and multi-channel network used to stop secondary interference. This paper develops two styles of network: the multi-transceiver multi-channel network and the closest multi-transceiver multi-channel device that uses the Time Division Multiple Access (TDMA) algorithm for EBMR-CS3,4 (Energy Bit Minimization Routing and centralized Scheduling). This algorithm is optimizing network efficiency by having higher throughput by preventing interaction with adjacent nodes and the scheduling duration and growing the device’s channel utilization ratio (CUR).
Using Recycled Coarse Aggregate in Reinforced Concrete Beams Strengthened for Shear by GFRP bars Using NSM Technique
Authors: Issa H M , Jomaah M M , Al-Shaarbaf I A
Published: August 2021

The NSM technique began to apply as a modern technique to treat defects in structural elements and to increase the shear and flexural strength of structural elements. For this technique to be effective, a series of practical experiments were conducted to characterize the behavior of the element strengthened by the NSM technique for flexure and shear. Shear strengthening with GFRP rods is the focus of this paper for concrete beams that contain 30% coarse aggregate replacement ratio of thermstone (volumetric ratio) obtained from the rubble of demolished buildings. A total of 7 beams were loaded under four-point load test, the parameters examined were the angle of inclination and the distance between the GFRP bars, the presence and absence of stirrups and the thermstone aggregate replacement ratio. The characterization of the tested beams includes failure mode, load-deflection curves, load-strain curves of stirrups, rebars and GFRP rods and the surface concrete strain in the shear zone of beam. The results showed that the use of GFRP rods to strengthen concrete beams was effective, especially in the presence of stirrups, where the gain in shear strength was 29.6% and 22.2% when the distance between the GFRP bars was (200 and 300) mm, respectively with the presence of stirrups. While the gain in shear was just (3.7% and 11.1%) in the absence of stirrups, when the distance between the GFRP bars was (200 and 300) mm, respectively.
The effect of different number of layers and fiber distribution on the performance of composite laminates
Authors: Mulaan Najjm Abdalla , Mahmood Amjed Saleh , Basturk Suleyman
Published: August 2021

Fiber-reinforced composites are widely used in world industries such as transportation vehicles, sports tools, space crafts, and more. This research investigates the influence of the number of layers and fiber distribution on the mechanical properties of woven fiber-reinforced composites by changing the number of layers or the manufacturing process. Hand lay-up and infusion processes are used to manufacture the composite plates. Three mechanical tests are conducted for all composite plates, such as Interlaminar shear stress (ILSS), ultimate tensile strength (UTS), and ultimate flexural strength (UFS). Furthermore, analyzing the microstructure of the laminates is conducted to evaluate fractal dimension (FD). It is observed that the distribution of the fibers measured by FD had an effective role in improving the mechanical properties. Also, the use of vacuum molds had an additional role in improving the mechanical properties. One could conclude that all the mechanical properties have proportional relationships with FD.
Synthesis and preparation of Nano-silica particles from Iraqi western region silica sand via SOL-GEL method
Authors: Kadhim Rawnak A. , Mohammed Abdulhaleem A. K , Hussein Halah M.
Published: August 2021

Nano-silica particles have been successfully synthesized from Iraqi western region sand (Al-anbar sand) by SOL-GEL method, the raw materials for this work were sodium hydroxide, concentrated sulfuric acid, de-ionized water in addition to the Iraqi sand. In this method; solid sodium silicate is dissolved in deionized water and then precipitated by adding concentrated sulfuric acid. The selection of the used Iraqi sand based on XRF analysis, then the produced Sample was studied using XRD, BET surface area, AFM, FT-IR, and SEM analysis, BET Surface area and average particle size were (438,215 m2/g) and (6 nm) respectively.
Influence of GFRP Vertical Stirrups Using NSM Technique on Shear Behavior of Reinforced Concrete Beams with Recycled Coarse Aggregate
Authors: Issa H M , Al-Shaarbaf I A S , Jomaah M M
Published: August 2021

Shear strengthening with GFRP rods is the focus of this paper on concrete beams that contain aggregate replacement ratios of thermstone and bonza (pumice materials), obtained from the rubble of demolished buildings. A total of nine beams (2400×160×300mm dimensions) were loaded under a four-point bending load test. The parameters examined in this research were the replacement ratio of lightweight coarse aggregate (20% and 30% volumetric ratio), type of lightweight aggregate replaced by (thermstone or bonza) and strengthened in shear by GFRP rods using NSM technique. The characterization of the tested beams includes ultimate load, failure mode, load-deflection curve, load strain curves of stirrups, bottom longitudinal rebars, GFRP rods at the shear zone of concrete. The results showed that the use of GFRP rods to strengthen concrete beams was effective. As the failure mode was transformed from a shear failure in the reference beam that was cast using normal concrete to a concrete compression failure in the beams which was occurred when using suitable and sufficient amount of strengthening by GFRP rods for selected used lightweight aggregate replacement ratios.
Effect of Calcinations Temperature on ZnO:Co Nanostructured Thin Films Prepared By Sol – Gel Method.
Authors: Kareem Shaima’a J. , Al-Majeed Elham Abd , Salam Afnan
Published: August 2021

Nanostructured ZnO thin films were developed on medical-glass substrates using a sol gel dip coating process and calcinated at various temperatures (350, 450, and 550 C°). The impact of Co doping and effect temperature calcination on the structural, optical and electrical properties of ZnO:Co nanostructured thin films were investigated using XRD, SEM, Hall effect, and UV-Visible spectra measurements. Both nanostructured films have hexagonal-wurtzite crystals composition according to XRD analysis with the average crystallite sizes of ZnO:Co nanostructured thin films are of (26.7-102.1) nm. The FESEM findings show that the undoped ZnO thin film has the smoothest and more regular surface compared to the doped ZnO films, indicating that both films with nanoscale ZnO particles. The average transmittance of all films is about 69–91 % in the visible range and the band gap energy decreased from 3.283 to 3.205 eV with increase of temperature calcination. The Hall impact indicates that all thin films are n-type and the electrical conductivity increase from (12.4-16.2) in the ZnO:Co thin films. This one of the outstanding property of ZnO thin films, both undoped and doped with cobalt, enables the fabrication of transparent electrodes for flat panel displays, metal-insulator-semiconductor diodes, and solar cells.
A review of Wire Arc Additive Manufacturing (WAAM) of Aluminium Composite, Process, Classification, Advantages, Challenges, and Application
Authors: Athaib Noor Hmoud , Haleem Ali Hubi , Al-Zubaidy Basem
Published: August 2021

Wire-arc additive manufacturing (WAAM) is a common metal 3D printing technique that offers several benefits, including the high rate of deposition, cheap price, and efficacy for complex parts. Even though (WAAM) has demonstrated its ability to meet the demands of manufacture components on medium-to-large size made of (Al) for the automotive and other related industries, WAAM cannot currently use as a complete production procedure due to practical issues such as mechanical properties that aren’t matched and the presence of significant residual stresses. the AM technologies offer promising new benefits with the MMCs as a solution for some challenges. This article reviews the MMCs Mixing technique and their critical issues, AM classification, WAAM process with advantages and challenges. also reviews WAAM of some AMCs with different reinforcements and power sources. The results of the study of the influence of reinforcement particles on the structure showed that they were changed grains structure from the columnar dendrite to equiaxial dendrites after the solidification and improves hardness.
Experimental investigation of base oil properties containing modified TiO2/CuO nanoparticles additives
Authors: Fahad Mustafa Raad , Abdulmajeed Basma Abbas
Published: August 2021

The majority of lubricating oil properties are the product of a material being used to enhance or produce the desired properties. Different materials with various nanostructures are now being used as new additives to improve lubricants’ properties due to their peculiar characteristics. In this study, oleic acid was used to surface-modified TiO2 and CuO nanoparticles to enhance the dispersion and stability of Nanofluid. The X-ray diffraction and Fourier transform Infrared spectroscopy FT-IR used to characterize the nanoparticles. The main objective of this paper was to investigate the influence of adding TiO2 -CuO nanoparticles on the thermal-physical properties such as kinematic viscosity, viscosity index, pour point and flash point of base oil and nano-lubricating oil, which is prepared by different concentration (0, 0.2, 0.5, 0.8, and 1 %) by weight, and also the contact pressure (load – carrying capacity) was examined by using commercial portable Timken tester. The results showed increases in viscosity index and flash point of nano-lubricant oil by 7.69% and 7.07%, respectively.
Technological strategies for recycling concrete block in Iraq
Authors: Al-Saffar Israa Mohammad , Al-Tameemi Osamah Abdulmunem
Published: August 2021

Many concrete recycling strategies have emerged and many studies were devoted so as to find the best alternative to recycle concrete waste in order to produce recycled concrete aggregates (RCA) with a quality that competes with natural aggregates which contribute to concrete mixtures and try to establish effective and practical treatment methods in applications of new concrete mixtures, where concrete is considered a building material. Concrete is considered as one of the basic materials in architecture because of its durability and strength and contributes to the worldwide constructional movement and proved its robustness, durability and flexibility in architectural applications as it is considered one of the most widespread material and in the meantime forms a burden impact on the environment at the end of its function in the structures, so it was necessary to employ technological strategies in order to face this dilemma that began to deteriorate our environment.

Therefore, the research problem is determined as the need to clarify the concept of concrete recycling and concrete waste recycling in Iraq, due to lack of local knowledge, to produce recycled concrete aggregate, applicable in the fields of architecture and can be used in new concrete mixtures.

The aim of this research is to provide knowledge on different methods of recycling concrete from construction and demolition waste (C&DW) and the possibility of reusing its components in new concrete mixes, and to raise a debate about the reality of concrete waste in Iraq and the recycling concrete technology and suggest the most effective technological strategy to solve the Iraqi concrete waste crisis.
A wideband Circular polarization cross printed dipole antenna with four quadrants parasitic
Authors: Hasan Mustafa , AlKafaji Nasr , Al-Anssary Hussam
Published: August 2021

The cross printed dipoles antenna is the best solution to generate wide band circular polarization, in this design prepared cross rectangular printed dipoles (antenna1) then added four inner quadrants parasitic (antenna2) with perfect arrangement and excellent dimensions. The quadrants, (inner parasitic) rotate sequentially round the crossed dipole, are used to persuade new resonance and increase the activity bandwidth, additional improving the AR bandwidth. The results show that the antenna achieves an impedance bandwidth (IBW) of 88.38% (4.66-12.04 GHz) for |S11| < −10 dB and a wide axial ratio bandwidth (ARBW) of 55.80% (5.75-10.2 GHz). The proposed antenna would be utilized in C-band applications and for wireless local area network (WLAN) applications. The structures modelled and analysed by the Ansoft’s HFSS simulation software.
Preparation and investigation of microstructure and wear properties of functionally graded materials of Aluminum-Nickel alloys
Authors: Al-Shafaie Saad Hameed , Radhi Nabaa S , Hussein Massoud Aziz
Published: August 2021

A functionally graded material is a high-performance engineering material that can withstand extreme working conditions without losing its properties or failing during operation. The design, fabrication, and characterization of Al-Ni integrated into single functionally graded materials are presented in this study. FGM (Al-Ni) have been successfully fabricated using the powder metallurgy process. FGMs samples are made up of five layers, starting with Al on one side and ending with Ni on the other. The FGM (Al-Ni) samples used in this research were made up of the following percentages: (100 Al, 25 Ni-75Al, 50Ni-50Al, 75Ni-25Al, and 100Ni) wt%. The samples were pressed with a load of 800 MPa and sintered at temperature 600°C for 3 hours. In this research we applied the wear test and X-ray analysis of FGM (Al-Ni) samples where the intermetallic phases that formed were (AlNi3, Al0.9Ni1.1, Ni5Al3, Al3Ni2, Al4Ni3, AlNi,), in addition to optical microscopy images.
Simulation study of biopolymer microspheres shape varying behavior
Authors: Muneer Roaa Mohammed , Hadi Nizar Jawad , Al-Zubiedy Ali
Published: August 2021

Simulation and modeling are very strong tools to design and simulate engineering cases that can be difficult to ably experimentally. In microscale domains, simulation and modeling play a very strong role to maintain results for specific cases that are hard to explain in microfluidic devices experimentally. Microfluidic devices were developed for mixing, separation, drug delivery, and microspheres formation. Drug delivery and microfluidic devices and modeling have a tight relationship that can solve and discuss the behavior of microspheres under variable formation process conditions. The main goal of this research is to discover the microspheres formation behavior under different flow rates. Experimentally, starch microspheres were formed with a different shape ranging from oval to spherical shape. This difference in shape was the main goal to study in this paper. To understand the shape changing, a numerical simulation study has been introduced using (ANSYS workbench 16.1) program, to simulate and study the microspheres formation process and the effect of flow rate varying on microspheres formation.
The effect of adding Ag nanoparticles on the electrical properties (A.C) of the PMMA-SPO-PS blend
Authors: Rabee Bahaa H , Haider Rafal
Published: August 2021

This paper investigates the Effect of Ag Nanoparticles on the PMMA-SPO-PS Blend, the samples of nano composition were prepared by adding Ag nano particles percentages of (1,3,5,7 mgm)wt % to the (SPO-PS-PMMA) blend, the thick films, It was the best blend when forgetting to mix (7mgm) silver nanoparticles were prepared by solvent with pure benzene at different time, The dielectric constant increases with increasing concentration and at frequency (from 100Hz to 3.E06Hz), and decreases with increasing frequency, the A.C electrical conductivity increases with increasing the frequency of applied electric field and concentrations of the (Ag) nanoparticles..
Buckling at Elevated Temperature for (6061-T6) Aluminum Alloy Columns under Increasing Load
Authors: Mshattat Shaymaa Mezaal , Al-Alkawi Hussein J , Reja Ahmed Hameed
Published: August 2021

A column is a structural member that bears an axial compressive load and is more likely to fail due to buckling than due to material strength. Some of these columns work at high temperature and this temperature effects the behavior of buckling. Then the designer must takes this factor into consideration. The present work involves the high-temperature buckling of 6061-T6 aluminum alloy rod(column) at different range of temperature (room temperature to 200°C). This work study the critical buckling load (Pcr) under the above temperature dynamically. The (Pcr) can be predicted by Euler theory. It has been observed that the Euler theory is not satisfy to applied under high temperature unless using temperature safety factor. The results show that elevated temperature weakens the structure and decreasing its mechanical and buckling properties. From the experimental results, empirical equations were derived to predict yield strength, ultimate tensile strength, modulus of elasticity, critical buckling load and temperature safety factor at high temperature.
Study the antibacterial activity of hydroxyapatite- nano silver coating on titanium substrate
Authors: Hamza Saja , Radhi Nabaa Sattar , Sahi Nebras Mohammed
Published: August 2021

The most often encountered laborer as a consequence prosthetic titanium (Ti) implant, failure is infection. Implant surfaces that are antibacterial due to nanoscale titanium modifications appear as an appealing peri-implantitis prevention approach. In this study, composite coating preparation) and antimicrobial properties (hydroxyapatite, hydroxyapatite/nanosilver) on titanium substrate by Micro Arc Oxidation(MAO). Preparation the electrolyte in the electrolyte, cell was an aqueous calcium acetate monohydrate solution of 0.1.3 mol/L ((CH3-COO)2..Ca.H2O) and 0.0.6 mol/l sodium biphosphate dihydrate (NaH2PO4.2H2O) in distilled, water, pH of electrolyte was 2.3 after that, nano silver was added to the electrolyte in different proportions (0.5, 1, 1.5, 2) g/L, and the coating times were also different (30, 45, 60) sec at a constant voltage 200 V. To observe the morphology a AFM test was done and must be known if there are bacteria present or not on Ti substrate and composite coating (HA, HA/nAg) samples by the antibacterial test. In addition, the surface, roughness was measured to study the extent of bacterial adhesion. The result of the tests for coated samples better compared with the uncoated sample. As a result, in the antibacterial test, composite coatings (HA, HA/nAg) were found to be more effective than Ti samples in destroying bacteria that had formed on their surfaces.
A Numerical Simulation Study to Improve Heat Transfer Rate in a Double Pipe Heat Exchanger using Different ways.
Authors: Salman Zomorrod Ahmed , Kadhim Zena Khalefa , khalaf Kamil Abdulhussein , Kamil Hassanein Ali
Published: August 2021

In this work the thermo hydraulic performance of double pipe heat exchanger made of stainless-steel with inner and outer diameters are (11.43 and 16.83cm) respectively, 0.305cm thickness and150cm length, studied numerically by using Solid Works 2016 package. It is used to the purpose of preheat heavy fuel oil flow in the outer pipe by hot air flow inside the inner one. Helical tape with different pitches (11, 14, and 17) cm the inner side of the inner tube and helical fin with different fin spaces (10, 20, and 30) cm over the inner tube are used as an enhancement heat transfer device. The study was conducted with specific identifiers, Reynold’s number (Re) values are (31668, 47361, 63008, 78589) for air side (inner tube), oil inlet temperature is (313) K and flow with rate of oil (0.1 and 0.06 kg/s). The results were first verified by using both the inner helical tape and outer helical fin separately and comparing the results of them with the plain tube, and then combining each of the helical tape and helical fin together and indicating the improvement in heat transfer rate, the result show that the maximum heat transfer is (4559.726 W) obtained by merged the helical tape with smaller pitch (11 cm) and helical fin with low fin pitch (10 cm) at oil flow rate (0.1 kg/s) as compared with (2052.385W) for plain tube, the maximum enhancement percentage in heat transfer rate and overall heat transfer coefficient were is (122.167 % and 142.941%) at the same conditions. The maximum enhancement in Nusselt number (Nu) and convection heat transfer coefficient were (224.572 % and 129.523 % W/m2. K) respectively were achieved by using helical tape with pitch (11 cm). At higher Reynolds number, the higher-pressure drop for air side is (7437.8 pa) obtained when using minimum pitch for helical tape and it is (1086.26 pa) for oil side by using helical fin with pitch (10 cm).
Evaluation the magnetic and microstructure properties of Al/TiO2 nanocomposites using various stir casting temperature
Authors: Kadhim Zahraa. J. , Alalkawi Hussain. J. M. , Reja Ahmed. H.
Published: August 2021

The effect of three stir casting temperatures (ST) (900, 1000, and 1100 on magnetic and microstructure properties of AA5052 reinforced with 5wt% TiO2 nanoparticles has been investigated using the stir casting technique. It was found that the magnetic properties decrease with increasing stir casting temperature and the least magnetic saturation (Ms) and magnetic susceptibility (Xm) occurred for nanocomposite fabricated under stir casting temperature (1000 °C) also the maximum coercivity (Hc) and residual magnetization (Mr) occurred in this nanocomposite. The values of magnetic saturation (Ms), coercivity (Hc) and residual magnetization (Mr) obtained for nanocomposite under (1000 °C) are 2.714×10−6 (A/m), 4676.55530 (A/m) and 3.25032 ×10−8 (A/m), respectively. Scanning electron microscopy (SEM) is used to analyze the microstructure, and it is discovered that well-distributed nano particles lead to decrease grain size in the parent phase.