bluuebunny/crossref_metadata_2025 huggingface dataset:
The role of surfactant to enhance photocatalyst performance on phenol degradation in TiO2-CNT composite-modified CNT (Cetyltrimethylammonium bromide)
Authors: Heltina D , Avisa U , Fermi M I
Published: March 2021

The TiO2-CNT composite – modified CNT (Cetyltrimethylammonium bromide) photocatalyst material was successfully prepared. The composites material was characterized by Scanning Electron Miscroscopy (SEM), X-ray Diffraction (XRD), Fourier Transform Infrared absorption spectroscopy (FTIR), and Breneur Emmet Teller (BET). The TiO2-CNT composite-modification CNT (Cetyltrimethylammonium bromide) formation obtained are discussed in detail. The highest performance effectiveness of photocatalyst material composites for degrading phenol was obtained on phenol concentration 10 mg/L and degradation temperature at 50°C was 98,74 %
Comparison of Natural Fiber Types as Reinforcement Material on Composite Mechanical Properties via Carbon Nanotubes Addition
Authors: Yolanda Y , Wulan Praswasti P D K
Published: March 2021

Composites with natural fiber reinforcement have been widely used in various field. Natural fibers have the advantages of easy recycling, environmentally-friendly characters, renewable, non-toxic, inexpensive, high toughness, good insulation against heat and noise, and good thermal properties. The aim of this paper is compare natural fibers used as reinforcing material on composite with an epoxy matrix and the addition of carbon nanotubes (CNT). The natural fibers used are oil palm empty fruit bunches (OPEFB), bagasse, and hemp fiber. Alkalization treatment with NaOH was carried out on natural fibers to remove impurities on the fiber surface and activate hydroxyl groups. CNTs need to be functionalized to achieve the desired compatibility. Functionalization is carried out by the mild acid oxidation method using nitric acid and hydrogen peroxide. Silane coupling agent treatment is carried out on natural fibers and CNTs to improve compatibility with the matrix. The result of the bending strength test of OPEFB, bagasse, and hemp fiber was 509.94 MPa, 36.22 MPa, and 18.12, respectively, in addition to CNT 0.5% mass. The bending strength of OPEFB fiberismore significant than bagasse and hemp fiber, so it has the opportunity to be developed in the automotive industry.
Improvement in the accuracy of the dynamic behaviour prediction of a bolted structure using a simplified finite element model and model updating
Authors: Omar R , Rani M N A , Yunus M A , Rusli M , Shah M A S A , Izhan W I , Mirza W I
Published: March 2021

Bolted joints in assembled structures contribute to the dynamic behaviour of the structures but also increase uncertainties in modelling and prediction of the dynamic behaviour. This paper presents a modelling scheme able to reduce uncertainties and increase the accuracy of the prediction. A finite element (FE) model of a bolted joint structure was developed using CBUSH, CBEAM and 3D elements representing the bolts, contacting interfaces, and structural components, respectively. Normal modes analysis was performed on the FE model to calculate the natural frequencies and mode shapes. Sensitivity analysis was formulated and used in identifying the highly sensitive design parameters of the FE model. Model updating was adopted in correlating the FE model with experimental modal analysis (EMA) and producing an updated FE model. It was found that the updated FE model is capable of predicting the dynamic behaviour of the bolted joint structure with 95 per cent accuracy. This proposed scheme demonstrated potential for applicability to the dynamic behaviour analysis of complex bolted structures.
Andalas Medical Robot Assistance (AMIRA) serves Covid-19 isolation patients
Authors: Ridwan F , Syamsuddin S , Fathan A , Ananta A A , Bintang G A , Jordan A , Ningsih Eka M , Fadel M
Published: March 2021

The world is currently alert to the spread of a virus known as the coronavirus. Corona Virus or Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a collection of viruses that can infect the human respiratory system until death. The spread of the virus is very fast and easy just by coming in contact with sufferers until it has contaminated almost all countries. For places prone to being exposed to viruses, especially in isolation rooms for Covid sufferers, the medical staff is terrified so that they are always on their toes; moreover, dozens of medical workers have died in handling patients. For this reason, innovation is needed to reduce contact between medical personnel and Covid-19 patients by replacing the duty of humans with robots so that the risk of infected medical workers decreases and avoids the level of work fatigue on the medical worker. The team from Andalas University created and designed a robot that could solve these problems. The robot was designed to perform activities carried out by nurses in serving patient’s needs. This robot has the necessary features: food delivery, the patient room’s smart position, protecting certain areas with disinfectants, reading the patient’s body temperature, and a reminder of the patient’s medication schedule anti-collision and providing other smart features which needed by the hospital. This robot is called Andalas Medical Robot Assistant or abbreviated as AMIRA.
Blending Between Aged and Virgin Asphalt Binders in Recycled Pavements: A Review Study
Authors: Pirzadeh P , Kapilan S , Kriz P
Published: March 2021

It is the intent of this work to provide a background on works on diffusion in asphalt binders and review the researches carried out at Imperial Oil and ExxonMobil Technology Centres which have investigated nature of diffusion in asphalt material. These investigations include diffusion between Reclaimed Asphalt Pavement (RAP) and virgin binders, progress of diffusion in laboratory-produced mix samples from rheology perspective, and impact of silo storage on diffusion progress between binders and its manifestation on the performance of plant-produced asphalt mix. RAP is a major component of manufacturing hot mix asphalt (HMA) in North America. RAP utilization promotes sustainability of asphalt industry with economic and environmental incentives for manufacturing process. Recent statistics in North America show that RAP content of HMA has increased from 15 to 20%. This RAP content increase further prompts development and implementation of science-based practices in manufacturing plants to achieve optimum quality of RAP containing mixes. Quality of blending between aged and virgin binders has been shown to significantly impact performance and durability of final mix in the field. It has been demonstrated that mechanical blending helps achieving effective contacts between RAP and virgin binder. However, diffusion is the dominant process to help blending between the binders. It has been demonstrated that binder diffusion follows Fick’s Law and the rate increases with temperature. Field verification indicated that around 12 hours is required to complete the diffusion at the typical hot mix production and silo storage temperatures. Mix samples with more-progressed diffusion exhibited improved rutting resistance and higher number of cycles to fatigue failure. Field work also validated that there is an optimum storage time during which diffusion is the dominant process impacting mix properties; but eventually mix hardening dominates due to oxidation, evaporation and absorption.
Characterization of pavement surface undulations using side view images
Authors: Jain Subham , Das Animesh
Published: March 2021

Pavement surface undulations affect friction, ride comfort, water drainage, noise etc. Various indices have been proposed in the literature to characterize the pavement surface undulations. The present paper compares a few pavement surface undulation indices in the spatial domain and the frequency domain. For this study, core samples of pavement surface were collected from freshly constructed pavements, which had not been opened to the traffic yet. The core samples were sliced using a high-speed diamond saw. Images of the side view of the slices were captured using a digital camera. Suitable image processing scheme was employed to detect the pavement surface profiles. Various indices were subsequently estimated and compared.
Utilization of jarosite in precast concrete paver blocks
Authors: Nandi S , Ransinchung G D R N
Published: March 2021

Sustainability has become the major concern for the construction industry in the recent era. Concrete stands as a versatile construction material, but cement being its main constituent poses a threat to the environment consuming a huge amount of energy and emanating CO2 and other greenhouse gases in its production process. On the other hand, the extraction of natural resources for construction works has been disrupting the environmental and ecological balance due to a huge accumulation of waste or by-products. So the major concern of the hour is the formulation of a mitigation strategy to fight this uncontrolled quantum of construction and its resulting consequences. The main objective of this present study is the utilization of jarosite, a hazardous solid waste, as a replacement of cement in concrete paver blocks. Six concrete mixes were prepared to keep the water-to-cementitious material ratio fixed at 0.43. The replacement of cement with jarosite was carried out at five replacement levels (0 – 25%) in an increment of 5%. Mechanical properties (compressive and flexural strength) and durability properties (water absorption and abrasion resistance) of the jarosite incorporated paver blocks were determined and compared to the control specimens. Experimental results indicate that mechanical and durability properties improve with the incorporation of jarosite, which could be attributed to a much developed packing of the jarosite concrete mix.
Development of structure model of hollow slab for solar pavement based on light-guide concrete
Authors: Zha X D , Hu H W , Wang Z W , Chen H P , Zhang C J
Published: March 2021

To develop a reasonable structure type of solar pavement, a kind of structure model of hollow slab was proposed for solar pavement based on light-guide concrete in this paper. It is composed of two parts: a rectangular hollow slab of light-guide concrete with an arch chamber as well as a solar panel which is installed in the arch chamber. Each light-guide body is compounded of a convex lens, a prism and a light-guide fiber. Through building a three-dimensional finite element model for the pavement structure of hollow slab, the mechanical responses of hollow slab were numerically simulated, thus the geometric sizes of arch chamber were optimized according to the requirements of bearing capacity. By establishing a simulation analysis model of light path for the light-guide body, the total solar energy of single day transmission for the light-guide body were numerically simulated, then the geometric sizes and optical parameters of light-guide body were optimized according to the condensing and light-guide performances. Accordingly, the steel shaping die was designed and manufactured, and the hollow slab model of light-guide concrete was prepared by taking self-compacting concrete as slab matrix. The mechanical properties and the power generation efficiencies were tested for the model. The results show that the developed hollow slab of solar pavement based on light-guide concrete has high strength, and its working voltage and maximum output power increase with the increase of the number of light-guide bodies. Therefore, the model can meet the dual function requirements of safe driving and clean power generation.
Continuously Separation of Sodium and Potassium Using an Adsorption Rotating Disc
Authors: Al-Falahi Hamed A , Awad E M
Published: March 2021

This paper is dealing with one of the applications of liquid chromatography using rotary disks. The research aims to study the effect of using distilled water (PH = 7) as a carrier phase and its absence on the practical results using NaOH and KOH at different speeds (2500, 3000, 3500 rpm). As well as choosing the best ratio of the diameter of the rotary disk nozzles that achieves the best displacement between the NaOH and KOH slides with paths separated from each other. Then propose a mathematical model that shows how the thickness of the slice sector behaves with changing the rotational speed. After that, calculating the pressure caused by the rotation and evaluating the results up to a speed of 12000 rpm. The practical results proved that the carrier fluid has an apparent effect on the displacement value between NaOH and KOH slides by changing the internal and external diameters of the rotating disk nozzles and the rotational speed from (500-3500 rpm). The effect of each of them was clear on the displacement of the injected slices from the center of the rotating disk and the convergence between the practical and theoretical results.
Integral Sliding Mode Control Design for a Quarter-Car Active Suspension System
Authors: Flayyih Mujtaba A , Hamzah M N , Hassan Jafar M
Published: March 2021

This paper utilizes the design of a robust integral sliding mode control (ISMC) for a quarter-car active suspension system. The main goal is to increase the ride comfort, whilst the road holding and rattle space remain within the safety bound. According to ISMC, the system state starts at the switch surface where the system nonlinearity, parameter changes, and road disturbances are rejected by a discontinuous control term present strongly in the suspension dynamics. This feature allows the design of a continuous controller, i.e. ideal controller during sliding motion from the first instant. Consequently, the car body is isolated from the wheel unit to perform the desired suspension requirements characteristics. The ISMC shows a high robustness control design of the suspension system, and can suppress chattering in the high-frequency band. The effectiveness of the proposed controller is performed by simulating the 2- DOF quarter car system with controlled and uncontrolled cases. The Matlab 2019a software is used to simulate the suspension models with bump road profiles as excitation disturbance.
An Experimental and Numerical Evaluation of Natural Frequencies and Mode Shapes using Vibration Isolator to Transport “Satellite Model–Plate Connecting Interface” System
Authors: Dahham Abbas Waheed , Taranenko Pavel Alexandrovich , Erpalov Aleksey Victorovich
Published: March 2021

This paper examines the natural frequencies and mode shape numerically and experimentally using vibration isolator for satellite model-plate connecting interface. The experiment was carried out using a modern software and hardware complex LMS. Vibration accelerations on the object were measured at 13 points in three mutually perpendicular directions using one-component and three-component PCB accelerometers with a sensitivity of 100 mV/g. Excitation was carried out with a PCB 086D50 m modal hammer. The SCADAS mobile data acquisition system was utilized to record the response from the sensors. While the numerical calculations were performed in the finite element package ANSYS Workbench. The result shows that the natural frequencies are less dependent on the system damping where the most considerable difference (about 10%) is observed in those forms, which plate makes flexural vibrations; the six natural modes of vibration of the satellite model (as a rigid body), the first three lowest forms correspond to vibrations in the plane. While the other oscillations were out of the plane, to reduce the oscillation frequency of the product from the plane (around the x and z axes), it is recommended to reduce the distance between the shock absorbers.
A Design Chart for Optimum Dimensions of Reinforced Concrete Cantilever Beams
Authors: Al-Shammaa Abdel Kareem M , Al-Mamoori Sohaib K
Published: March 2021

This theoretical study focused on cantilever reinforced concrete beams with a rectangular cross-section (different dimensions) subjected to bending moments due to uniformly distributed loads. By creating an algorithm and using the Python 3.4 software, the beams’ length was calculated for each cross-section dimension to check the required immediate and sustained deflections according to ACI 318M-19. Based on the analysis output, a graphical relationship was developed between the dimensions of the cantilever beam’s cross-section versus the maximum length to control the allowable deflection of the beam. Finally, the author was able to draw a simplified novel graph to facilitate the selection of cross-sections required for specified lengths of cantilever concrete beams.
The Urban Capitals: A New Guide for Sustainable and Smart Development
Authors: Al-Khafaji Rashaa Malik Musa
Published: March 2021

Global attention is focused on transforming cities and urban areas and trying to trace their success path. This research assumes that cognitive development is based on what is termed knowledge capital, a framework that includes a combination of core capital for the operation of knowledge-based economic processes and mechanisms to enhance them in the areas of product development. This research aims to determine aspects of development and the foundations and mechanisms of knowledge cities. The indicators include the knowledge cluster, and knowledge diversity was identified as a product of the urban capital’s implementation, measured by indicators of urban, social, economic, and cultural dimensions of urban capital. The indicators derived from the theoretical framework were applied for research in several international and Arab experiments in the applied part of the research and applying these indicators within a local situation.
Spiral Flow Heat Exchanger Effect on Photovoltaic/Thermal System Performance
Authors: Al-Zubidi S M Dina , Sanaa A Hafith , Radhi Amera A , Mahdy Aedah M J , Ibrahim Sulafa I
Published: March 2021

The photovoltaic modules produce electricity directly by making use of sunlight. However, these modules are clearly affected by atmospheric conditions such as irradiation, temperature, relative humidity and dust. The greater part of the radiation is converted into heat which leads to the heating of the PV module resulting in degradation in the power productivity. In the present research, a spiral heat exchanger was added to the PV module to circulate water forming a PV/T system. This exchanger was welded to the back of the PV panel. The exchanger absorbs the excess heat from the panel and losing it through the cooling water in an outside exchanger. The tests were carried out in Baghdad weather conditions during May 2020. The highest solar radiation intensity measured during the measurement period was 823 W/m2 while the highest ambient air temperature was 44°C in the shade at 1:30 PM for the day 23/5/2020. The study focused on investigating the effect of the used heat exchanger on the PV/T system’s generated parameters. The most important results that were extracted from the study are that the studied PV/T system current was increased by 7.8%, the voltage by 3.3%, the power by 11.48%, and the efficiency up to 21.33% as compared to the photovoltaic panel. The PV/T system produced thermal efficiency ranging from 34.3% at 9 AM to the maximum value of 56.66% at 4 PM. The PV/T system’s electrical efficiency in this study was compared with the literature, and it was found that the studied system gave an acceptable electrical efficiency.
Performance Optimization of Hybrid ROFSO Link Using Hybrid Optical Amplifiers (RAMAN\EDFA) for Long-Haul Transmission with the C-band and L-band Comparison
Authors: Alnajjar Satea H , Zuhair S Esraa , Arif Fouad Abdul Razzaq
Published: March 2021

In this paper, a hybrid system is proposed consisting of a radio-frequency (RF) over free space optic/fiber optic (RFOFSO/FO). A free-space communication system is an alternative to optical fibers if it fails in performance or if it is difficult to propagate. This hybrid system is an effective solution for developing new generation networks, by transmitting the optical signal over long distances within the C-band, and L-band. The proposed system sends the radio frequency signal through the optical free-space link then extends to 80 km of optical fiber, of which 40 km is amplified by the Raman/EDFA hybrid optical amplifier. This paper aims to test the performance of the free space optic link under different weather conditions. The atmospheric attenuation, which reduces visibility, was considered as the main challenge. Several copies were sent in different paths in FSO to meet this challenge. The submitted system was implemented in the case of transmission in a wavelength within the C-band and also in L-band. The results of the hybrid system were compared by measuring the bit error rate (BER) and Q-factor under dust and fog conditions relative to Kim’s standard model by using Optisystem. The results obtained showed an effective sensation at a long haul, inn addition to not using an additional light source when transmitting for such long distances.
Experimental Investigation of Phase Change Material as an Insulator in Hollow Brick Wall
Authors: Abbas Hayder M , Jalil Jalal M , Ahmed Sabah T
Published: March 2021

In this paper, an experimental study has been conducted for using a PCM as a thermal insulation material in a south wall of a room. Two identical cubic rooms were fabricated from sandwich panels except for the south wall (test wall) was built as an Iraqi domestic wall. South wall orientation was chosen as the test wall due to the significant amount of solar radiation falling on it so that the study compared two test walls, a wall without PCM or not treated wall (NTW) and a wall embedded with PCM or treated wall (TW). The results show that using PCM in TW will increase the time lag by 1 hour and decrease the inner surface wall and room temperature by about 2.7 °C compared with NTW.
Kinematic Analysis of Underactuated Robotic Finger Design
Authors: Mohammed R Ahmed , Soud Wafa Abd , Baqer Ihsan A
Published: March 2021

This paper presents a kinematic analysis of a novel underactuated robotic finger design. The design finger is a development of an index finger of the Ottobock hand. Namely, it consists of three phalanges with 3-degrees of freedom. A four-bar mechanism was used to make the finger self-adaptive with the grasped object. The Solidworks software was used to create the design, and the ANSYS software was used to analyze the design. The kinematic equations of the novel design are derived to get the optimum values of the links dimension that achieved the optimum grasping force by using the genetic algorithm. The normal force was measured by using the grasping force measuring mechanism. The models were manufactured using a 3D printer with hard Polylactic acid (PLA) printing material. The contact points’ normal force between phalanxes and grasping force measuring mechanism was measured using a load cell. The experimental results of the normal force of the finger were closed to the theoretical results.
Mitigating the Volume of Inflow and Infiltration Entering the Sewage Network during the Storm of the Trunk Sewage Line (A Case Study in Karbala-Iraq)
Authors: Htif Khawlah A , Nile Basim k , Mohammed Hussein Ali
Published: March 2021

Managing rainwater in light of climate variability is one of the most difficult problems facing urban areas in the world. Heavy rainfall contributes to increased infiltration of rainwater and effluent (RDII) into the sewage systems, which leads to system overflow and thus increased environmental pollution. This study aims at reducing the volume of surface runoff and thus reducing the volume of inflow and infiltration that enters the sewage network during the storm of the main sewage line of Karbala city. To investigate the extent to which the proposed solution would mitigate floods in the study area, the rainwater Management Model [SWMM] used data density for hourly precipitation from 2016 - 2019. The results indicate that the size of the flood was reduced to more than 75%, while the flood time decreased from 38 hours to 8 hours. The overload limit was reduced from 25 manholes to 5 manholes reduced (80%), and the excess duration were reduced by 55%. Total sanitary sewer overflow (SSO) 95m3 and area flooding 633m2. This analysis is expected to provide a comprehensive solution to mitigate sewage flooding during a storm and provide support to decision-makers to reduce environmental and health problems during heavy rains.
Effect of Natural Fillers on the Tensile and Flexural Properties of PMMA used in Denture Manufacture
Authors: Jassam Ahmed , Mohammed Farag Mahel , Hamad Hassan M
Published: March 2021

The mechanical properties of the dental are very important in order to make the proper selection of the right material to be used by the dentist. The effect of natural filler on the mechanical properties of PMMA used for denture manufacture has been investigated. Three natural materials, which are Siwak, Pomegranate, and Olive, are selected. The filler is prepared by grinding the material and sieving it to get the filler with a grain size of 50, 75, and 100 μm for each. The filler is added with three weight fractions in which become four parameters with three levels. Using the standard Taguchi’s array L9 (43). S/N ratio and ANOVA are used to determine the optimum process parameters with their significant factor. The results show that the optimal parameters combination with their levels for higher modulus of elasticity appear by using grain size of 75 μm with (0.6% Olive, 0.6% Pomegranate, and 0.9% Siwak) filler weight fraction. Whereas for the tensile strength and bending strength at (100 μm, with (0.6% Olive, 1.2% Pomegranate and 0.9% Siwak)) and 75 μm, with (0.9% Olive, 0.6% Pomegranate and 0.9% Siwak) respectively. The Siwak filler has the most significant influence on the mechanical properties with contribution ranged from (25-52) %, followed by pomegranate filler. The grain size affects tensile strength more than the other mechanical properties. The experimental and predicted results are very close, with errors not exceed 4%.
A Biomedical Device for Early Detection of Symptoms of Mild Cognitive Impairment (MCI) and Alzheimer Disease (AD)
Authors: Ahmed Qayssar A , Al-Neami Auns Q H
Published: March 2021

The present study aims to design and implement a biomedical device helps in the diagnosis of mild cognitive impairment (MCI) and Alzheimer disease (AD). It is an electronic device that provides information helps in the early diagnosis of people suffering from (MCI) in current time which may develop into (AD) in the future. The design was based on the event related potential (ERP) principles with audio stimulation, by acquiring the stimulated brain waves from (P3 and P4) regions in the parietal lobs. The audio stimulated signals that pass through a series of amplifications with gain of approximately 880x and filtering processes and then recoded as sound waves to be analyzed by MATLAB resulting in a final wave that helps in the diagnosis of (MCI) or (AD).
Gain and Noise Figure Analysis of Erbium Doped Fiber Amplifier Based on Double Pass Configuration Using Forward Pumping
Authors: Awsaj Mohammed K , Goktas H Haldun , Yucel Murat , Awsaj Mahmood K
Published: March 2021

In this paper, gain and noise figure of Erbium Doped Fiber Amplifier (EDFA) is analyzed based on double pass with Wave Selective Coupler (WSC). The main contribution in this study the use of a (WSC) to eliminate the residual pump power out of the signal and attain optimal result in L-band. This method decreases the self-saturation effect of ASE. Also, the study shows the effect on input and output signal power in L-band Erbium Doped Fiber Amplifiers with pump power using forward pumping. Moreover, the researchers analyzed the high-yield behavior and characterization details of the new double-pass EDFA with WSC. Finally, the study shows the effects of pump power on gain and noise figure with input and output signal power in L-band at 1590 nm.
Conventional and Fuzzy Control for First Order Plus Dead Time Process Using Different Tuning Methods
Authors: Mousa Al-zobai Khalid M , Makki Dalya S
Published: March 2021

This research discusses the performance of closed loop control system to control the first order process with dead time which represents most of the chemical processes. Proportional, proportional integral and proportional integral derivative controls were used to characterize the performance of the closed loop. Fuzzy logic control as advanced strategy was used to improve the characteristic of the response. Different tuning methods (Cohen-Coon, Ziegler Nichols and internal model) were used for tuning the controllers. The results showed that the fuzzy control greatly improves the performance of the closed loop system because the rise in the controlled variable is arrested more quickly, and it returns rapidly to the original value with little or no oscillation. Hence, the system is more stable with Fuzzy control.
Electro-Kinetic Removal (EKR) of Heavy Metals from Contaminated Soil using Palm Fibers and Organic Material
Authors: Ajjam S , Karbool M
Published: March 2021

The heavy metals that are contaminating the soil considered a global problem and especially in Iraq. One of the latest techniques is EKR that can hand a senior promise to clean the contaminated soil with heavy metals. Iraq is the top country in terms of the number of palm trees and the dates that are produced each year, which eliminates thousands of tons of waste are eliminated. This study involves, firstly, mediating an EKR off-site pilot study of impact assessment of the organic material in the soil at a pH of 3. Regent HNO3 and diluted NaOH were chosen to set the samples of distilled water, reaching the desired pH value. Secondly, test the capacity of date palm fibers (DPF) as a low cost, obtainable, and eco-friendly invert osmosis blocker. In this pH 3, organic removal of copper is more active than without the organic material of the same ph; 50 %, 47%, on the way. However, it was concluded that in Iraq, the utilization of organic materials and fibers of the palm are available at low cost, and materials of eco-friendly have succeeded to improve the removal of copper method in the EKR Reactor; via raising the efficiency of copper (%R) removal to be around 50%.
Overview of Joining and Repairing Techniques of Ni-Based Superalloy for Industrial Gas Turbine Applications
Authors: AL-Nafeay Ruaa H , AL-Roubaiy Ahmed O , Omidvar H
Published: March 2021

In industrial gas turbine (IGT) engine manufacturing, nickel-based superalloys are used mainly to meet the needs of components of the hot gas pathway. Although these alloys have high-temperature capabilities, the parts are prone to damage during service. The high working temperatures of these engines lead to component degradation due to creep, fatigue, and oxidation reactions; therefore, due to the high cost of newly produced superalloy components, it is usually more cost-effective to repair the damaged parts rather than completely replacing them. Joining and repairing techniques are necessary when manufacturing and repairing these alloys. This article will present an overview of the Ni-based superalloy for industrial gas turbine application by studying the microstructure of Ni-based superalloy, weldability issues, and cracking phenomena. Joining/repairing techniques of Ni-base superalloy with advantages and limitations to each technique are discussed to know a suitable technique for use in the high-temperature application.
Study of Elastic Modulus and Roughness of Porous Alumina Toughened Zirconia
Authors: Ibrahim S N , Zaidan Sh A , Mohammed M A
Published: March 2021

Alumina Toughened Zirconia (ATZ) composite with 20 wt% alumina has been prepared by powder compaction method after stabilized zirconia using 3 mol. of yttria to get the 3Y-TZP compound. A graphite additive (0,10,20,30, and 40) wt.% have been added to produce porous ATZ. The composite has been sintered in the air at 1500 °C. The effect of porosity on physical and structural properties have been investigated. Porosity increased, and bulk density decreased with graphite additives increases in the range (7.5-51.7) % and (5.6-2.8) g/cm3 respectively for (3Y-TZP/20 wt% Al2O3) specimens. The porosity effect is apparent by deteriorating the mechanical properties; the diametric strength decreased from 95.7 to 8.7 MPa, while the young modulus decreased from 159.7 to 27.3 GPa with porosity increases. Surface morphology was detected by atomic force microscope (AFM). The average grain size and roughness of 3Y-TZP/20 wt% Al2O3 specimens increased with increasing porosity from 75.44 to 91.9 nm and 2.9 to 18.7 nm, respectively. It was found that porous ATZ was successfully fabricated by using graphite additives. The apparent porosity of 3Y-TZP/20 wt% Al2O3 composite after sintering can be controlled by the amount of graphite content in the powder mixture. The presence of porosity greatly influences physical and microstructural properties.
MWCNTs Addition to Al2O3-SiC Binary Coating Deposited by Plasma Thermal Spray on Low Carbon Steel Substrate
Authors: Jalal Zainab , Al-Sultani Kadhim F , Majdi Hassan Sh
Published: March 2021

Coating with alumina and silicon carbide on low alloy steel specimens surface was conducted by using plasma thermal spray technique. The coating was of different percentages of alumina and silicon carbide (75% alumina +25% silicon carbide, 50% alumina + 50% silicon carbide) and then carbon nanotube was added to the mixtures of powder with percentage of 1%. Cyclic hot corrosion test was done after coating and XRD and SEM were performed to all samples after corrosion. Coating thickness was measured by SEM cross-section micrographs. The weight change of bare and coated specimens after 50 hours of corrosion in 67% wt. V2O5 + 33% wt. Na2SO4 at 950 °C was measured. The maximum reduction in weight was shown by specimens coated with 50% wt. alumina +50%wt. silica carbide with addition of 1% carbon nanotube . X-Ray of coated samples indicated that no phase change occurred to the coating materials. Scanning electron microscopy imaging of surface layer clarified that surface layer has relatively moderate porosity and some coating layers contain micro-cracks.
Investigation of the Effect of Wire Electrical Discharge Machining on the Fracture Toughness of Aluminum-Boron Carbide Composite
Authors: Al-Ethari Haydar , Fadhil Zahraa
Published: March 2021

Aluminum metal matrix composites reinforced by ceramic particles have a wide acceptance in engineering applications due to their mechanical and physical properties. One of the major challenges in machining these composites by the conventional machining operations is the presence of the abrasive particles, which affects the tool life and the required surface finish. Electro discharge machining process is widely used instead of conventional methods to overcome these challenges. Therefore, it is essential to study the influence of the electro-discharge machining on its fracture toughness, as it is the most important structural integrity indicator in the wide range applications of the studied composites. In this work, all samples were prepared by the stir casting method with using a squeezing pressure during the solidification. Samples were reinforced by (0, 2, 4, and 6wt %) of B4C particles with a size of 0.387μm. The fracture toughness studied were based on the stress intensity factor, determined experimentally by using compact tensile test and numerically using the finite element method. The fracture toughness improvement was recorded for the samples containing 4wt% of B4C.
Preparation and Characterization of CuO/MgO Nano Particles using Sol-Gel Technique
Authors: Yassen D A , Othman F M , Hamead A A Abdul
Published: March 2021

Copper oxide CuO and Magnesium oxide MgO are considered among the most promising oxides in the current development. Nanocomposite particles NCPs of MgO-CuO were synthesized by using the sol-gel method. The copper (II) nitrate trihydrate 0.1M and Magnesium nitrate hexahydrate 0.1M solvents were mixed at a 1:1 ratio and the gel was formed at a temperature of 80 °C, then dried calcined at 500 °C for different time (3, 5, and 7 hours). The CuO/MgO particles were characterized by particle size analyzer (PZA), X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and apparent density. The result of x-ray diffraction proved the phases purity of the composite particles. On the other hand, FESEM images proved nanoparticles embedded in the MgO-CuO matrix with a particle size of 33.5 –63.27 nm. Moreover, the density for the above samples was 0.699, 0.721, and 0.755 g/cm3 respectively. It increases with increasing the calcined time. This stimulates the growth of crystals CuO/MgO which exhibits excellent catalytic activity for the advanced application.
Advantages of cryogenic machining technique over without-coolant and with-coolant machining on SS316
Authors: Karthik Rao M C , Malghan Rashmi L , Shettigar Arun Kumar , Herbert Mervin A , Rao Shrikantha S
Published: March 2021

The analysis concentrated towards the influence of speed of the spindle along with a cryogenic (LN2) cooling technique in treating SS316 using CNC (Computerized numerical control) milling machine. An comparative study path was set and anlyised among three states i.e. Dry (Without coolant), wet (With coolant) and cryogenic (With liquid LN2) machining using coated carbide inserts. The coolant used in case of wet machining was water-soluble, referred to as cutting fluid. The experimental range falls in 3 different levels of spindle speed (SS), such as low level (1000 rpm), medium level (2000 rpm), and high level (3000 rpm), respectively. Meanwhile, feed rate (FR) and depth of cut (DOC) were reserved steadily with 450 mm min−1, 1 mm separately. This vital focus is towards cryogenic (LN2) machining effects and its perception of machinability on SS316, such as tool wear –TW (μm), cutting force–CF (N), cutting temperature–CT (ºC) and surface roughness–Ra (μm). The experiments were conducted and documented with cryogenic (LN2) techniques to establish the fairness and practicability of the method to compare with without-coolant (dry) and with-coolant (wet) machining. The attained statistical results in comparison of LN2 method over without-coolant and with-coolant machining concerned to test cases for CF- Fx (N), CT (ºC), Ra (μm) and FW (μm) are 53.21%–34.20%, 65.88%–44.51%, 75.43%–44.27%, & 59.76%–23.10%, respectively.
Generalized Poisson distributions for systems with two-particle interactions
Authors: Hameeda M , Plastino Angelo , Rocca M C
Published: March 2021

In a cosmological context, observational best fits for galaxies’ distributions in the Universe have been tackled by recourse to different distribution functions. We provide here arguments favoring the formulation of a rather general distribution function (DF), of Poisson origin, describing galaxy clustering. The DF should be useful irrespective of distances or temperatures. We will be discussing distribution function for gravitational interactions.
Inter-rater reliability of care home staff’s proxy judgements with residents’ assessments of their own health-related quality of life: an analysis of the PATCH trial EQ-5D data
Authors: Kelly Charlotte , Hulme Claire , Graham Liz , Ellwood Alison , Patel Ismail , Cundill Bonnie , Farrin Amanda , Goodwin Madeline , Hull Karen , Fisher Jill , Forster Anne
Published: March 2021

Objectives

to compare care staff proxies with care home residents’ self-assessment of their health-related quality of life (HRQoL).

Methods

we assessed the degree of inter-rater reliability between residents and care staff proxies for the EQ-5D-5L index, domains and EQ Visual Analogue Scale at baseline, 3 months and 6 months, collected as part of the PATCH trial. We calculated kappa scores. Interpreted as <0 no agreement, 0–0.2 slight, 0.21–0.60 fair to moderate and >0.6 substantial to almost perfect agreement. Qualitative interviews with care staff and researchers explored the challenges of completing these questions.

Results

over 50% of the HRQoL data from residents was missing at baseline compared with a 100% completion rate by care staff proxies. A fair-to-moderate level of agreement was found for the EQ-5D-5L index. A higher level of agreement was achieved for the EQ-5D-5L domains of mobility and pain. Resident ‘non-completers’ were more likely to: be older, have stayed a longer duration in the care home, have lower Barthel Index and Physical Activity and Mobility in Residential Care (PAM-RC) scores, a greater number of co-morbidities and have joined the trial through consultee agreement. Interviews with staff and researchers indicated that it was easier to rate residents’ mobility levels than other domains, but in general it was difficult to obtain data from residents or to make an accurate proxy judgement for those with dementia.

Conclusions

whilst assessing HRQoL by care staff proxy completion provides a more complete dataset, uncertainty remains as to how representative these values are for different groups of residents within care homes.
Acceptance and commitment therapy for late-life treatment-resistant generalised anxiety disorder: a feasibility study
Authors: Gould Rebecca L , Wetherell Julie Loebach , Kimona Kate , Serfaty Marc A , Jones Rebecca , Graham Christopher D , Lawrence Vanessa , Livingston Gill , Wilkinson Philip , Walters Kate , Le Novere Marie , Leroi Iracema , Barber Robert , Lee Ellen , Cook Jo , Wuthrich Viviana M , Howard Robert J
Published: March 2021

Background

Generalised anxiety disorder (GAD) is the most common anxiety disorder in older people. First-line management includes pharmacological and psychological therapies, but many do not find these effective or acceptable. Little is known about how to manage treatment-resistant generalised anxiety disorder (TR-GAD) in older people.

Objectives

To examine the acceptability, feasibility and preliminary estimates of the effectiveness of acceptance and commitment therapy (ACT) for older people with TR-GAD.

Participants

People aged ≥65 years with TR-GAD (defined as not responding to GAD treatment, tolerate it or refused treatment) recruited from primary and secondary care services and the community.

Intervention

Participants received up to 16 one-to-one sessions of ACT, developed specifically for older people with TR-GAD, in addition to usual care.

Measurements

Co-primary outcomes were feasibility (defined as recruitment of ≥32 participants and retention of ≥60% at follow-up) and acceptability (defined as participants attending ≥10 sessions and scoring ≥21/30 on the satisfaction with therapy subscale). Secondary outcomes included measures of anxiety, worry, depression and psychological flexibility (assessed at 0 and 20 weeks).

Results

Thirty-seven participants were recruited, 30 (81%) were retained and 26 (70%) attended ≥10 sessions. A total of 18/30 (60%) participants scored ≥21/30 on the satisfaction with therapy subscale. There was preliminary evidence suggesting that ACT may improve anxiety, depression and psychological flexibility.

Conclusions

There was evidence of good feasibility and acceptability, although satisfaction with therapy scores suggested that further refinement of the intervention may be necessary. Results indicate that a larger-scale randomised controlled trial of ACT for TR-GAD is feasible and warranted.
DCI: learning causal differences between gene regulatory networks
Authors: Belyaeva Anastasiya , Squires Chandler , Uhler Caroline
Published: March 2021

Designing interventions to control gene regulation necessitates modeling a gene regulatory network by a causal graph. Currently, large-scale gene expression datasets from different conditions, cell types, disease states, and developmental time points are being collected. However, application of classical causal inference algorithms to infer gene regulatory networks based on such data is still challenging, requiring high sample sizes and computational resources. Here, we describe an algorithm that efficiently learns the differences in gene regulatory mechanisms between different conditions. Our difference causal inference (DCI) algorithm infers changes (i.e. edges that appeared, disappeared, or changed weight) between two causal graphs given gene expression data from the two conditions. This algorithm is efficient in its use of samples and computation since it infers the differences between causal graphs directly without estimating each possibly large causal graph separately. We provide a user-friendly Python implementation of DCI and also enable the user to learn the most robust difference causal graph across different tuning parameters via stability selection. Finally, we show how to apply DCI to single-cell RNA-seq data from different conditions and cell states, and we also validate our algorithm by predicting the effects of interventions.

Availability and implementation

Python package freely available at http://uhlerlab.github.io/causaldag/dci.

Supplementary information

Supplementary data are available at Bioinformatics online.
LSTrAP-Kingdom: an automated pipeline to generate annotated gene expression atlases for kingdoms of life
Authors: Goh William , Mutwil Marek
Published: March 2021

Motivation

There are now more than two million RNA sequencing experiments for plants, animals, bacteria and fungi publicly available, allowing us to study gene expression within and across species and kingdoms. However, the tools allowing the download, quality control and annotation of this data for more than one species at a time are currently missing.

Results

To remedy this, we present the Large-Scale Transcriptomic Analysis Pipeline in Kingdom of Life (LSTrAP-Kingdom) pipeline, which we used to process 134 521 RNA-seq samples, achieving ∼12 000 processed samples per day. Our pipeline generated quality-controlled, annotated gene expression matrices that rival the manually curated gene expression data in identifying functionally related genes.

Availability and implementation

LSTrAP-Kingdom is available from: https://github.com/wirriamm/plants-pipeline and is fully implemented in Python and Bash.

Supplementary information

Supplementary data are available at Bioinformatics online.
Zbed3 Is Indispensable for Wnt Signaling Regulation of Cortical Layers Formation in Developing Brain
Authors: Ruan Xiangbin , Liu Gaoao , Zhou Jiafeng , Chen Pan , Sun Changjie , Liu Wei , Wu Chao , Hou Lin , Yin Bin , Qiang Boqin , Shu Pengcheng , Peng Xiaozhong
Published: March 2021

Wnt/β-catenin signaling plays multiple important roles during mammalian brain development, and it regulates the proliferation and differentiation of neural progenitors in a context-dependent manner and affects neocortex layer formation. However, the specific role of Wnt/β-catenin in neuronal layer fate determination in the neocortex is still unclear. Here, we report that Zbed3, which is a positive regulator of Wnt/β-catenin signaling, colocalizes with β-catenin at the endfeet of radial glia in the ventricular zone of embryo mouse neocortex. Overexpression and knockdown of Zbed3 increased and decreased the activity of Wnt/β-catenin signaling in the neocortex, respectively. Interestingly, knockdown of Zbed3 in vivo could significantly shift neuronal fates from deep layers to upper layers but is not required for the proliferation and differentiation of neural progenitors. Overexpression of Zbed3 led to increased generation of deep-layer neurons without impairing cell cycle exit of neural progenitors. More importantly, knockdown of Zbed3 could effectively block the effects of the ectopic expression of stabilized β-catenin on neocortex layer formation. Hence, our results demonstrate that Zbed3 is indispensable for Wnt/β-catenin signaling regulating neuronal layer fates in the developing brain.