bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Silica Fume on the Performance of Bacterial Concrete
Authors: Doshi Tejas , Patil Umesh P , Patil M B 
Published: August 2021

Abstract
The main aim of this experiment is to study the effect of bacteria on the strength and durability properties of normal and silica fume (SF) concrete. The experiment is carried out to evaluate influence of Pseudomonas putida bacteria on the compressive strength, shear strength, sulphate attack and water sorptivity on concrete. Cement was replaced with 20% SF by weight. Three different cell concentrations (103, 105, 107cells/ml) of bacteria were used in making the concrete mixes. The tests were carried out on the strength and durability properties after complete curing of 28 days. The inclusion of Pseudomonas putida in SF based concrete has an ability to enhance strength and improve durability of concrete. The study showed that concrete having bacterial infusion in all cell concentrations have increment in strength in comparison to reference mix. From the test results, it was concluded that, optimum cell concentration for concrete was found to be 105 cells/ml. The strength and durability properties were enhanced due to addition of bacteria in SF concrete compared to plain concrete. The calcite precipitation in concrete was visualized through SEM and is the reason for improvement in properties of concrete due to filling of pores by the growth of filler materials resulting in denser concrete.
Effect of Curing Methods on Fly Ash based Concrete
Authors: Sai Srinath BLN , Venkata Ramesh K , Patnaikuni Chandan Kumar , Soujanya Vani V , Potharaju M 
Published: August 2021

Abstract
Concrete is known to be is the most used construction material throughout the world to meet the needs of major infrastructure projects. Its superior structural strength and stability are mainly due to the presence of binding material cement. The production of cement accounts for large amounts of carbon-di-oxide throughout the world. This percentage is estimated to rise further increasing the CO2 levels in the coming future. It may not be avoided entirely, but it can be partially reduced by using supplementary cementitious materials. Fly ash is one such material that can be partially replaced with cement, with altering the strength of conventional concrete. Fly ash ranging from 0% to 50% was replaced with cement and the concrete was evaluated for compressive strength. Curing is also an essential factor in order to achieve the desired strength to the concrete. The heat produced during the hydration process needs to be brought down by curing, to maintain the favourable conditions for the surface of concrete. Various curing methods have been adopted, such as complete water immersion curing, 3-day water immersion curing, wet burlap curing, compound curing, and open-air curing. These specimens were tested for compression at 3 days, 7days and 28 days. It is concluded from the experimental results that at all ages, 20% fly ash replacement resulted in better strength. Complete water immersion curing proved to give better strength results, followed by wet burlap curing, 3-day immersion curing, compound curing, and open-air curing.
Study of environmental radioactivity and radon measurement associated health effect due to coal and fly ash samples
Authors: Singh L M , Singh K Y , Mahur A K 
Published: August 2021

Abstract
The increasing demand for electricity generation in India primarily depends on coal-fired power plants. The burning of coal is known as fly ash and a prominent factor of pollution in the environment. Fly ash generation in plants leads to the creation of radon and radionuclide, which affects the health of the general public. Since the general public around the area adjoining power plants are at considerable risk of radiation exposure. Also, inhalation of radon gas at a high level increases the possibility of lung cancer. So monitoring radon and radionuclide concentrations is essential. In the present investigation, radon and thoron exhalation rates have been estimated by implementing the accumulation method-based active technique. Natural radioactivity concentrations have been found out using NaI(Tl) detector-based gamma-ray spectrometry. Since the radiation hazard index is less than unity, so fly ash retains not a considerable amount of radiation effect. The result obtained concludes that radon/thoron exhalation rate and radioactivity concentration from fly ash residues are within the limits prescribed by the competent authority. So, the uses of fly ash in coal-based power plants cause no effectively adverse effect on health.
Evaluation of Strength Parameters of Metakaolin and Nanosilica Incorporated High-Performance Concrete
Authors: Gadag Pushpalatha R , Somasekharaiah H M , Ghorpade Vaishali , Sudarsana Rao H 
Published: August 2021

Abstract
This article presents the evalution of strength properties of High-Performance Concrete (HPC) due to the addition of nanosilica and metakaolin. Metakaolin partially replaces the cement at 10%, 20%, and 30% by weight. The addition proportions of nanosilica are 0%, 1. 5%, 3.0%, and 4.5% by weight of binder for each of the metakaolin replacement levels. Water-to-binder ratios of 0.3, 0.325, 0.35, 0.375, 0.4, and 0.425. The hardened HPC mixes were tested for their compressive, split tensile, and flexural strength at 7 and 28 days. Additionally, the compressive strength test was carried out after 90 days of curing to study the long-term strength development. The obtained results were compared with conventional concrete as a reference mix. HPC with 10% metakaolin, 3% nanosilica and 0.3 water-to-binder ratio yielded the best performance with 36.11%, 31.75% and 34.59% improvement in 7, 28 and 90 days compressive strength respectively. The improvement in split tensile strength were 25.24% and 40.26% at 7 and 28 days respectively. The flexural strength was enhanced by 41.10% and 30.30% at 7 and 28 days respectively. Furthermore, mathematical relationships between cube compressive strength and split tensile strength, flexural strength were derived from the experimental results of this investigation.
Studies on Effect of Recycled Aggregate on Deflection Characteristics of RC Slab
Authors: Poongodi K. , Revathi P. , Murthi P. 
Published: August 2021

Abstract
Substantial utilization of natural aggregates leads to the depletion of the naturally available resources. Hence an alternative approach is to utilize the recycled concrete aggregate (RCA) from the construction and demolition waste in the production of concrete and also in the prevention of dumping this waste in cultivable landfill. On the other side, codal provisions available for the predication of deflection in reinforced concrete one-way slab using effective moment of inertia (leg) were not comparable with the experimental values. Hence in the present study, it is proposed to study the load and deflection characteristics of simply supported slabs by varying the percentage of RCA content as 0 %, 50 % and 100 % under two point loading. Further, the work is extended to compare the deflection values obtained from experimental studies to the computed deflection values based on the IS 456:2000, ACI 318:2008 and BS: 8110. From the results, it is inferred that the replacement of natural aggregate with RCA does not affect the deflection characteristic of RC slab. Moreover, the computed deflection based on IS: 800, ACI and BS codal provisions does not match with the experimental deflection.
Sustainability Studies on Concrete Partial Replacement of Sugarcane Granular Bagasse-ash in Cement
Authors: Gaddam Kalpana 
Published: August 2021

Abstract
In recent times, the research in every branch of science and technology is focusing on utilisation of waste materials from different sources such as agricultural, industrial etc., It is both economically beneficial as well as helps in creating a pollution free environment. Various agricultural waste such a sugar cane bagasse ash is also utilised in recent times as it has high amount of silica content. It is a waste product from sugar refinery industry. With the increase in production of sugar, the disposal of bagasse ash becomes difficult. Hence utilisation of bagasse ash as a replacement to cement was experimented by few researchers and found that certain paste properties could be increased by using bagasse ash at certain percentage replacements. In this research, the bagasse ash was replaced by weight of ordinary Portland cement in concrete. The replacement percentage varied from 0 to 15% with a 5% interval. The proportions of cement aggregate and water was finalised by following standard mix design procedure given in IS-10262. Both fresh and hardened concrete properties were tested in each mix. It was observed that the slump value was decreased with the increase in bagasse ash content, the hardened properties like flexural strength, compressive strength, have indicated no major difference in strength levels up to 10% replacement of bagasse ash. Similar trend was observed in the results of 7, 14 and 28 days. With further research, the bagasse ash replacement in concrete can be made more sustainable.
Strength and Durability Studies on Hybrid Fiber Reinforced High-Performance Concrete for Silica Fume Based Mineral Admixture
Authors: Adanagouda  , Somasekharaiah H.M. 
Published: August 2021

Abstract
This study aims to investigate the strength and durability studies on Hybrid fibers reinforced High-Performance Concrete for Silica fume (SF) based mineral admixture. A constant proportion of 0.25% for polypropylene fibers (PF) and varying proportions of 0%, 0.5%, 0.75% and 1.0% for crimped steel fibers (CF) making a total fiber volume fractions of 0%, 0.75%, 1.0% and 1.25% were used to develop hybrid fiber-reinforced high-performance concrete (HFRHPC). Four replacement levels for hybrid fibers by volume of the binders and four partial replacement levels for Silica fume (0%, 10%, 20% & 30%) by weight of cement have been considered for three different water binder ratios (0.275, 0.325 & 0.375). An aggregate binder ratio of 1.75 was kept constant. The test results reveal a maximum increase of 35.18%, 40.35%, and 71.54% in compressive strength, split tensile strength, and flexural strength, respectively, for a curing period of 28 days. Acid attack tests have been conducted to measure the durability of HFRHPC. Cubes of 100x100x00mm have been cast, cured, and then kept immersed in 5% concentrated solutions of Hydrochloric acid (HCL), Magnesium sulphate (MgSO4), and Sulphuric acid ( H2SO4) for 30,60 and 90 days and then tested to record the residual compressive strength of HFRHPC produced with the Silica fume mineral admixtures. The results have been analyzed, and valid conclusions have been drawn. The results indicate that a combination of 1.25% hybrid fibers and 10% Silica fume mineral admixture gains all the water-binder ratios’ highest strength.
Ternary Blended Geo-Polymer Concrete – A Review
Authors: Khalid S Md , Shobha M S , Tanu H M , Reshma T V 
Published: August 2021

Abstract
The manufacturing of ordinary Portland cement produces carbon di oxide which is responsible for global warming. Geopolymer concrete in the field of construction leads to economic sustainability and reduces adverse effects on environment. Geopolymers are inorganic polymers obtained from chemical reaction between an alkaline activator’s solution and an alumina-silicate material without using cement. Alkali activators are Homogeneous mixture consisting of two (NaOH and Na2SO3) or more chemicals in different proportions are highly corrosive and difficult to handle. There are still some limitations with respect to the alkaline activators in geopolymer concrete. To overcome ordinary portland cement, many wastes materials such as Silica-fume, GGBS, fly ash etc. have been used in recent studies to create eco-friendly cements by geo-polymerization reactions. Geopolymers are economic & good alternative construction material in making concrete This review paper briefly explains on previous literatures, properties, materials of geopolymer concrete, testing and practical applications of geopolymer concrete.
Static and modal analysis of sine-wave-shaped spar
Authors: Elshazly E , Kassem M , Elshafei M A , Kamel M 
Published: August 2021

Abstract
Sine-Wave-shaped Spar (SWS) is recently involved in wing design as one of the corrugated shaped spars that highly improve the torsion and buckling resistance. SWS is an I-beam made of sine wave shaped vertical web fixed to upper and lower flanges. The current research evaluates the behavior of SWS in comparison to the traditional straight-web spar in resisting two cases of loading; static bending loading and static torsion loading. For each case, deformation and stress are analyzed. Modal analysis is also performed for the two spar configurations. For this purpose, a finite element model is developed using Ansys Workbench software for the SWS and the straight web spar. To reach a fair comparison, similar weight is considered for the two spar structures. A parametric study is performed to investigate the effect of web thickness and flange thickness on the bending and torsion deformation and stresses. The effect of thickness variation on the natural frequencies and mode shapes is also considered. The current study can be considered a base to design wing spars that combine the merits of the two spar configurations.
Numerical simulation of temperature field in a C/C composite multidisk brake during aircraft braking
Authors: Ramadan E M , Hussien A E , Youssef A M , El-Badia T M Abd 
Published: August 2021

Abstract
This article presents a finite element method for simulating the heat production during stopping the aircraft. Thermal analysis and simulation in the finite element model are based on the theory of energy transformation and transportation. A commercial software COMSOL Multiphysics 5.5a is used for simulating the braking operation. The internal temperatures of the brake disks were obtained and the variation in temperatures between disks were discussed. Thermomechanical behaviour is studied to show the effect of thermal energy on the contact mechanics for the friction surfaces between the brake disks. Aircraft mass, initial velocity and deceleration rate are responsible for heat generation and consequently the maximum reached temperature during braking. The friction surfaces between disks were the main heat energy source where the heat was concentrating on these layers of friction surfaces. For the selected braking operation, the maximum reached temperature was 1020K. The finite element model was validated against historical data for a Boeing737-400 at constant deceleration for new disk brakes and for RTO brake energy.
Design of a smart energy efficient IoT wireless node
Authors: Nabil M S , Tammamand A F , ElKhatib M M 
Published: August 2021

Abstract
The Internet of Things (IoT) is gaining greater effect in our life from day to day. Wireless sensor networks (WSN) are embedded into the “Internet of Things” and power saving is one of the problems that it faces. This study introduces a new circuit design for a DC-DC Buck-Boost converter for controlling the output voltage of Energy Harvester (EH) via adaptive Neuro-Fuzzy inference systems (ANFIS) controller. It has proven that there is an effective changes regarding settling time almost being zero, overshoot being negligible and steady state voltage. As an application for the proposed design, an implementation for Precision Agriculture (PA) self-sustainable Wireless Sensor-Node (WS-N) with low power consumption has been presented. A solar power management for Precision agricultural in internet of things system proved to enhance cost-efficiency and increased lifetime for the device. The simulation results are determined by means that of MATLAB/Simulink software. The cloud service of Blynk IoT has been implemented to monitor the collected data on real time. Data on solar cells, batteries and soil were regarded reliable and precise.
Comparative study between cognitive radio techniques in FM broadcasting band
Authors: Hamed I , Elmenyawi M A , Hassan A Y 
Published: August 2021

Abstract
Optimum usage of the existing frequency spectrum is a major requirement due to the large increase in the number of subscribers at the same frequency. The cognitive radio scheme has become an important application used to optimize spectrum utilization, detects spectrum bands that are not occupied by primary users to create communication links between secondary users in the same band. These non-occupied bands are described as white space. In this paper, a spectrum sensing method that is an important stage in cognitive radio communications is discussed. Various spectrum sensing methods such as energy detection (ED) and cyclostationary feature detection (CFD) are used to sense the spectrum in the FM broadcasting band. A comparison of energy detection and cyclostationary feature detection spectrum sensing methods is made to determine the empty bands in the FM broadcasting band. This enables secondary users to transfer information in these empty bands without affecting the primary users of the FM broadcasting system.
Enhanced image encryption algorithm by quantum key distribution
Authors: Mahmoud M A , Mekkawy T , Elbayoumy A D 
Published: August 2021

Abstract
Quantum Key Distribution (QKD) is one type of Quantum Cryptography (QC) which is based on quantum mechanics fundamentals such as Heisenberg’s uncertainty principle and No-cloning theory. The usage of QKD warns the legitimate communicated parties to any attack attempt and this is the most interesting security parameter. Therefore, QKD provides unconditional secure communication method and supports a powerful encryption scheme. The combination between classical communication and QKD creates a new technique called semi quantum key distribution SQKD. Unfortunately, SQKD increases the schemes complexity and requires two steps for ciphering, scramble and encryption. In this paper an enhance image encryption algorithm is proposed based on QKD that eliminates most of the drawbacks of SQKD. The proposed algorithm is simpler than other encryption schemes as it exploits only one encryption step based on the power and the randomness of the generated secret key, which decreases the chance to be cracked. The correctness and efficiency of the proposed algorithm are validated by numerical simulations.
Assessment of top of atmosphere reflectance generation algorithm for world view-2 high resolution images
Authors: Allam M , Mahmoud T , Elsharkawy A , Sheta B 
Published: August 2021

Abstract
Recently, there are many developments in remote sensing techniques using satellite imagery as a result of the variety of remotely sensed image sources with different spatial and spectral resolutions and from different sensors. Optical satellite products are affected by an error of payload, atmosphere (scattering and absorption), and variations relative to positions of Sun, Earth, and satellite during capturing data. Top of Atmosphere (TOA) correction is the process of removing the effects of variations relative to sensor error and positions of Sun, Earth, and satellite. In this paper, maximum benefits from high spectral and spatial resolution images are demonstrated and analyzed or compared with images from different. TOA correction algorithm, which was implemented using Python environment, is applied to high resolution images from WorldView-2 (WV-2) satellite. TOA reflectance is considered the first step in any algorithm dedicated to the change detection process. Reflectance conversion is also performed on the same images using Orfeo ToolBox (OTB), the open-source software. The performance and efficiency of the proposed algorithm are compared with that of the Orfeo ToolBox (OTB) TOA reflectance output. The achieved results show that the proposed algorithm, which is automatically performed, is faster and provides significant results for WV-2 images, and can be adapted to be applied on different optical satellite sensors.
Non-destructive aerial and terrestrial analysis of uranium isotopic activity by sensitive α-spectrometer for El-Sella site
Authors: Sabry M , Omar A , Abdel-Rahman M A , El-Mongy S A 
Published: August 2021

Abstract
Any comprehensive radioactivity surveillance for a specific site should be carried out by a sensitive airborne system (e.g. carried on aircraft) together with terrestrial sampling and analysis. In the framework of ore, environmental and nuclear materials monitoring and investigation, the activity and isotopic compositions signature are considered crucial factors that must be considered, determined and evaluated. In this work and based on previous aerial monitoring, a very sensitive hyper pure germanium detector (Hp-Ge) of 50% efficiency with the Genie 2000 software has been used for spectroscopic non-destructive assay (NDA) of radioactivity content for samples collected from the Egyptian eastern desert (El-Sella Site). The identification of specific signature isotopes through their characteristic gamma lines and a calculation of their specific activities, activity ratios of 235U/238U and 234U/238U and mathematically estimation of the natural enrichment percentage are very vital and nuclear forensic targets. The results of measurements, analysis and calculations show that the Site samples have high radioactivity, natural enrichment origin and high uranium concentration. The obtained results are given tabulated, depicted, discussed and compared with the recent nationally published work and the international levels and limits.
On the unsteady behaviours of the adiabatic endwall film cooling effectiveness
Authors: Qenawy M , Liu Y , Zhou W 
Published: August 2021

Abstract
The film cooling technique is introduced in modern gas turbines to protect the blade from the high temperature of the incoming hot gases by forming a thin coolant blank over the blade surface. However, it is known as a jet in crossflow (JICF), where coolant and mainstream interact intensively and generate complex vortices leading to highly unsteady coolant coverage over the blades surface. In this study, a fast-response pressure-sensitive paint technique (fast-PSP) was used to measure the coolant unsteadiness with a high-resolution camera. The measurements were performed in a novel single-passage transonic wind tunnel to uncover the unsteady effectiveness of the endwall surface. Such effectiveness was dramatically influenced by the blowing ratios (M), showing attached flow at a low blowing ratio and lift-off at a high blowing ratio. The effectiveness was asymmetrically distributed due to the pressure gradients, jet compounding angle, and associated complex flows. The unsteady effectiveness was highly influenced by the energetic vortical structures, which interacted with the mainstream flow immediately behind the holes. It was featured by secondary structures (horseshoe, passage, and counter vortices) beside the JICF structures. Meanwhile, the unsteadiness was originated from the middle of the passage behind the holes. It is suggested to pay close attention to the locations of the holes for further optimization. This study could help the designers to understand the characteristics of unsteady effectiveness, promoting advanced cooling strategies for enhanced protection of future gas turbines.