Search results for: coupled double quantum well (CDQW)

Authors: Spoorthi Sripad

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Rapid advancements in LiDAR (Light Detection and Ranging) technology, coupled with the synergy of remote sensing, have revolutionized Earth observation methodologies. This paper delves into the transformative impact of integrated LiDAR and remote sensing systems. Focusing on miniaturization, cost reduction, and improved resolution, the study explores the evolving landscape of terrestrial and aquatic environmental monitoring. The integration of multi-wavelength and dual-mode LiDAR systems, alongside collaborative efforts with other remote sensing technologies, presents a comprehensive approach. The paper highlights the pivotal role of LiDAR in environmental assessment, urban planning, and infrastructure development. As the amalgamation of LiDAR and remote sensing reshapes Earth observation, this research anticipates a paradigm shift in our understanding of dynamic planetary processes.

Keywords: LiDAR, remote sensing, earth observation, advancements, integration, environmental monitoring, multi-wavelength, dual-mode, technology, urban planning, infrastructure, resolution, miniaturization

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Authors: A. Amar

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A new model, namely the crystal model, has been modified to calculate the radius and density distribution of light nuclei up to ⁸Be. The crystal model has been modified according to solid-state physics, which uses the analogy between nucleon distribution and atoms distribution in the crystal. The model has analytical analysis to calculate the radius where the density distribution of light nuclei has obtained from analogy of crystal lattice. The distribution of nucleons over crystal has been discussed in a general form. The equation that has been used to calculate binding energy was taken from the solid-state model of repulsive and attractive force. The numbers of the protons were taken to control repulsive force, where the atomic number was responsible for the attractive force. The parameter has been calculated from the crystal model was found to be proportional to the radius of the nucleus. The density distribution of light nuclei was taken as a summation of two clusters distribution as in ⁶Li=alpha+deuteron configuration. A test has been done on the data obtained for radius and density distribution using double folding for d+⁶,⁷Li with M3Y nucleon-nucleon interaction. Good agreement has been obtained for both the radius and density distribution of light nuclei. The model failed to calculate the radius of ⁹Be, so modifications should be done to overcome discrepancy.

Keywords: nuclear physics, nuclear lattice, study nucleus as crystal, light nuclei till to ⁸Be

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Authors: Abu Harera Nadeem, Kingsley Donkor

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Tea is a popular beverage due to its flavour, aroma and antioxidant properties—with the most consumed varieties being green and black tea. Antioxidants in tea can lower the risk of Alzheimer’s and heart disease and obesity. However, these teas contain heavy metals such as Hg, Cd, or Pb, which can cause autoimmune diseases like Graves disease. In this study, 11 heavy metals in various commercial green, black, and oolong tea samples were determined using inductively coupled plasma-mass spectrometry (ICP-MS). Two methods of sample preparation were compared for accuracy and precision, which were microwave-assisted digestion and ultrasonic-assisted extraction. The developed method was further validated by detection limit, precision, and accuracy. Results showed that the proposed method was highly sensitive with detection limits within parts-per-billion levels. Reasonable method accuracy was obtained by spiked experiments. The findings of this study can be used to delve into the link between tea consumption and disease and to provide information for future studies on metal determination in tea.

Keywords: ICP-MS, green tea, black tea, microwave-assisted acid digestion, ultrasound-assisted extraction

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Authors: Maged Assem Soliman Mossallam

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Microsatellites' low available power limits the usage of active thermal control techniques in these categories of satellites. Passive thermal control techniques are preferred due to their high reliability and power saving which increase the satellite's survivability in orbit. Steady-state and transient simulations are applied to the microsatellite design in order to define severe conditions in orbit. Satellite thermal orbital three-dimensional simulation is performed using thermal orbit propagator coupled with Comsol Multiphysics finite element solver. Sensitivity study shows the dependence of the satellite temperatures on the internal heat dissipation and the thermooptical properties of anodization coatings. The critical case is defined as low power orbiting mode at the eclipse zone. Using black anodized aluminum drops the internal temperatures to severe values which exceed the permissible cold limits. Replacement with anodized titanium returns the internal subsystems' temperatures back to adequate temperature fluctuations limits.

Keywords: passive thermal control, thermooptical, anodized titanium, emissivity, absorbtiviy

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Authors: H. Ucar, U. Aridogan

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Composite structures become intriguing for the design of aerospace, automotive and marine applications due to weight reduction, corrosion resistance and radar signature reduction demands and requirements. Studies on piezoelectric ceramic transducers (PZT) for diagnostics and health monitoring have gained attention for their sensing capabilities, however PZT structures are prone to fail in case of heavy operational loads. In this paper, we develop a piezo-based Glass Fiber Reinforced Polymer (GFRP) composite finite element (FE) model, validate with experimental setup, and identify the applicability and limitations of PZTs for a marine application. A case study is conducted to assess the piezo-based sensing capabilities in a representative marine composite structure. A FE model of the composite structure combined with PZT patches is developed, afterwards the response and functionality are investigated according to the sea conditions. Results of this study clearly indicate the blockers and critical aspects towards industrialization and wide-range use of PZTs for marine composite applications.

Keywords: FRP composite, operational challenges, piezoelectric transducers, FE modeling

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Authors: Patrizia Frontera, Anastasia Macario, Simona Crispi, Angela Malara, Pierantonio De Luca, Stefano Trocino

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The exploration of solar energy for the photoelectrochemical splitting of water into hydrogen and oxygen has been extensively researched as a means of generating sustainable H₂ fuel. However, despite these efforts, commercialization of this technology has not yet materialized. Presently, the primary impediments to commercialization include low solar-to-hydrogen efficiency (2-3% in PEC with an active area of up to 10-15 cm²), the utilization of costly and critical raw materials (e.g., BiVO₄), and energy losses during the separation of H₂ from O₂ and H₂O vapours in the output stream. The SERGIO partners have identified an advanced approach to fabricate photoelectrode materials, coupled with an appropriate scientific direction to achieve cost-effective solar-driven H₂ production in a tandem photoelectrochemical cell. This project is designed to reach Technology Readiness Level (TRL) 4 by validating the technology in the laboratory using a cell with an active area of up to 10 cm², boasting a solar-to-hydrogen efficiency of 5%, and ensuring acceptable hydrogen purity (99.99%). Our objectives include breakthroughs in cost efficiency, conversion efficiency, and H₂ purity.

Keywords: photoelectrolysis, green hydrogen, photoelectrochemical cell, semiconductors

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Authors: Kyung-Hoon Jang, Jae-Hyo Park, Kwang-Yeop Jang, Dongjin Kim

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The Tesla coil is an electrical resonant transformer circuit designed by inventor Nikola Tesla in 1891. It is used to produce high voltage, low current and high frequency alternating current electricity. Tesla experimented with a number of different configurations consisting of two or sometimes three coupled resonant electric circuits. This paper focuses on development and high voltage education to apply a Tesla coil to cuisine for high quality flavor and taste conditioning as well as high voltage education under 50 kV corona discharge. The result revealed that the velocity of roasted black belly pork by Tesla coil is faster than that of conventional methods such as hot grill and steel plate etc. depending on applied voltage level and applied voltage time. Besides, carbohydrate and crude protein increased, whereas natrium and saccharides significantly decreased after lightning surge by Tesla coil. This idea will be useful in high voltage education and high voltage application.

Keywords: corona discharge, Tesla coil, high voltage application, high voltage education

Procedia PDF Downloads 328

Authors: Najwa Mimouni, Omar Rahli, Rachid Bennacer, Salah Chikh

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In the present work 2D and 3D numerical simulations of double diffusion natural convection in an elongated enclosure filled with a binary fluid saturating a porous medium are carried out. In the formulation of the problem, the Boussinesq approximation is considered and cross Neumann boundary conditions are specified for heat and mass walls conditions. The numerical method is based on the control volume approach with the third order QUICK scheme. Full approximation storage (FAS) with full multigrid (FMG) method is used to solve the problem. For the explored large range of the controlling parameters, we clearly evidenced that the increase in the depth of the cavity i.e. the lateral aspect ratio has an important effect on the flow patterns. The 2D perfect parallel flows obtained for a small lateral aspect ratio are drastically destabilized by increasing the cavity lateral dimension. This yields a 3D fluid motion with a much more complicated flow pattern and the classically studied 2D parallel flows are impossible.

Keywords: bifurcation, natural convection, heat and mass transfer, parallel flow, porous media

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Authors: Mahdi Fakoor, Seyed Mohammad Navid Ghoreishi

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Composite patching is a common way for reinforcing the cracked pipes and cylinders. The effects of composite patch reinforcement on fracture parameters of a cracked pipe depend on a variety of parameters such as number of layers, angle, thickness, and material of each layer. Therefore, stacking sequence optimization of composite patch becomes crucial for the applications of cracked pipes. In this study, in order to obtain the optimal stacking sequence for a composite patch that has minimum weight and maximum resistance in propagation of cracks, a coupled Multi-Objective Genetic Algorithm (MOGA) and Finite Element Method (FEM) process is proposed. This optimization process has done for longitudinal and transverse semi-elliptical cracks and optimal stacking sequences and Pareto’s front for each kind of cracks are presented. The proposed algorithm is validated against collected results from the existing literature.

Keywords: multi objective optimization, pareto front, composite patch, cracked pipe

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Authors: P. J. Moore-Jones

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Emirati students studying at the University of the Emirates, one of three major public institutions of higher learning in the United Arab Emirates (UAE), have a wide demographic of faculty members teaching them an equally wide variety of courses. These faculty members bring with them their own cultural assumptions, methods, expectations, educational practices and use of language. The history of multiculturalism in the UAE coupled with the contemporary multiculturalism that exists in higher education Dubai create intriguing phenomena within the classroom. This study seeks to delve into students’ and faculty members’ perceptions of the social stratification that exist in this context. Data were collected via semi-structured interviews with both and analyzed from an interpretive perspective. Findings suggest the social stratification with is deeply-seeded in the multicultural history of the region and country are reflected in the everyday interworkings of education in modern day Dubai. The relevance of this research lies in that these findings can provide valuable insights into not only the attitudes and perceptions of these Emirati students might also be applicable to any of those student populations may exist.

Keywords: social stratification, intercultural competence, Dubai, United Arab Emirates

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Authors: Jainendra Singh, Zaheeruddin

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A typical wireless sensor networks (WSNs) consists of several tiny and low-power sensors which use radio frequency to perform distributed sensing tasks. The longevity of wireless sensor networks (WSNs) is a major issue that impacts the application of such networks. While routing protocols are striving to save energy by acting on sensor nodes, recent studies show that network lifetime can be enhanced by further involving sink mobility. A common approach for energy efficiency is partitioning the network into clusters with correlated data, where the representative nodes simply transmit or average measurements inside the cluster. In this paper, we propose an energy- efficient homogenous clustering (EHC) technique. In this technique, the decision of each sensor is based on their residual energy and an estimate of how many of its neighboring cluster heads (CHs) will benefit from it being a CH. We, also explore the routing algorithm in clustered WSNs. We show that the proposed schemes significantly outperform current approaches in terms of packet delay, hop count and energy consumption of WSNs.

Keywords: wireless sensor network, energy efficiency, clustering, routing

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Authors: Janet Joy, Shri Shailesh Amarkhed, Pradeep M. Kulkarni

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Introduction: Ureteral stent-related symptoms significantly impact patients' quality of life. This study compared the efficacy of Mirabegron, Tolterodine, and Fesoterodine in managing these symptoms. Methodology: In this prospective, randomized, placebo-controlled trial, two hundred patients undergoing ureteral stenting were randomly assigned to receive Mirabegron, Tolterodine, Fesoterodine, or placebo for two weeks. Symptoms were assessed using the Ureteral Stent Symptom Questionnaire (USSQ) at stent removal. Results: 200 patients completed the study. Mirabegron demonstrated the lowest mean USSQ score (31.6 ± 6.4), followed by Fesoterodine (34.0 ± 6.9) and Tolterodine (35.0 ± 7.2), all significantly lower than placebo (48.6 ± 8.7, p<0.001). Mirabegron showed superior efficacy in reducing urinary symptoms (score: 16.5 ± 3.9) compared to Fesoterodine (17.8 ± 4.1) and Tolterodine (18.2 ± 4.3). Side effects, such as parched mouth, were less frequent with Mirabegron (6%) than with Tolterodine (28%) and Fesoterodine (24%). Conclusion: All three medications significantly improved stent-related symptoms compared to placebo. Mirabegron demonstrated a trend toward superior efficacy and fewer side effects, suggesting its potential as a first-line treatment for stent-related discomfort.

Keywords: ureteral stent, mirabegron, tolterodine, fesoterodine, USSQ, stent-related symptoms

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Authors: Mohammed Sghir Taleb

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Located at the northwest corner of the African continent between 21 ° and 36 ° north latitude and between the 1st and the 17th degree of west longitude, Morocco, with a total area of 715,000 km², enjoys a privileged position with a coastline of 3 446 km long opening to the Mediterranean and the Atlantic Ocean. Its privileged location with a double coastline and its diverse mountain with four major mountain ranges: the Rif, Middle Atlas, High Atlas, and Anti Atlas, with altitudes exceeding 2000 m in the Rif, 3000 m in the Middle Atlas, and 4000 m in the High Atlas. Morocco is characterized by an important forest genetic diversity represented by a rich and varied flora and many ecosystems: forest, preforest, presteppe, steppe, Sahara that spans a range of bioclimatic zones: arid, semiarid, subhumid, and humid. The vascular flora of Morocco is rich and highly diversified, with a very significant degree of endemism. Natural flora and ecosystems provide important services to populations represented by grazing, timber harvest, harvesting of medicinal and aromatic plants. This work will be focused on the Moroccan biodiversity and natural ecosystem services and on the interaction between local populations and ecosystems

Keywords: biodiversity, forest, ecosystem, services, Morocco

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Authors: Harold Jideofor

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The application of Project Management (PM) tools and techniques in the public sector is gradually becoming an important issue in developing economies, especially in a country like Nigeria where projects of different size and structures are undertaken. The paper examined the application of the project management practice in the public sector in Nigeria. The PM lifecycles, tools, and techniques were presented. The study was carried out in Lagos because of its metropolitan nature and rapidly growing economy. Twenty-three copies of questionnaire were administered to 23 public institutions in Lagos to generate primary data. The descriptive analysis techniques using percentages and table presentations coupled with the coefficient of correlation were used for data analysis. The study revealed that application of PM tools and techniques is an essential management approach that tends to achieve specified objectives within specific time and budget limits through the optimum use of resources. Furthermore, the study noted that there is a lack of in-depth knowledge of PM tools and techniques in public sector institutions sampled, also a high cost of the application was also observed by the respondents. The study recommended among others that PM tools and techniques should be applied gradually especially in old government institutions where resistance to change is perceived to be high.

Keywords: project management, public sector, practice, Nigeria

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Authors: Varun Joshi, Manish K. Rathod

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The latent heat thermal energy storage system is a thrust area of research due to exuberant thermal energy storage potential. The thermal performance of PCM is significantly augmented by installation of the high thermal conductivity fins. The objective of the present study is to obtain optimum size and location of the fins to enhance diffusion heat transfer without altering overall melting time. Hence, the constructal theory is employed to eliminate, resize, and re-position the fins. A numerical code based on conjugate heat transfer coupled enthalpy porosity approached is developed to solve Navier-Stoke and energy equation.The numerical results show that the constructal fin design has enhanced the thermal performance along with the increase in the overall volume of PCM when compared to conventional. The overall volume of PCM is found to be increased by half of total of volume of fins. The elimination and repositioning the fins at high temperature gradient from low temperature gradient is found to be vital.

Keywords: constructal theory, enthalpy porosity approach, phase change materials, fins

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Authors: A. Moualdia, D. J. Boudana, O. Bouchhida, A. Medjber

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Wind energy has many advantages, it does not pollute and it is an inexhaustible source. However, the cost of this energy is still too high to compete with traditional fossil fuels, especially on sites less windy. The performance of a wind turbine depends on three parameters: the power of wind, the power curve of the turbine and the generator's ability to respond to wind fluctuations. This paper presents a control chain conversion based on a double-fed asynchronous machine and flow-oriented. The supply system comprises of two identical converters, one connected to the rotor and the other one connected to the network via a filter. The architecture of the device is up by three commands are necessary for the operation of the turbine control extraction of maximum power of the wind to control itself (MPPT) control of the rotor side converter controlling the electromagnetic torque and stator reactive power and control of the grid side converter by controlling the DC bus voltage and active power and reactive power exchanged with the network. The proposed control has been validated in both modes of operation of the three-bladed wind 7.5 kW, using Matlab/Simulink. The results of simulation control technology study provide good dynamic performance and static.

Keywords: D.F.I.G, variable wind speed, hypersynchrone, energy quality, hyposynchrone

Procedia PDF Downloads 367

Authors: María R. Contreras, Diana Endara

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Cyanide leaching is the most used technology for gold mining industry, which produces large amounts of effluents requiring treatment. In Ecuador the development of gold mining industry has increased, causing significant environmental impacts due to the highly use of cyanide, it is estimated that 10 gr of extracted gold generates 7000 liters of water contaminated with 300mg/L of free cyanide. The most common methods used nowadays are the treatment with peroxodisulfuric acid, ozonation, H₂O₂ and other reactants which are expensive and present disadvantages. Several methods have been developed to treat this contaminant such as heterogeneous catalysts. Layered double hydroxides (LDHs) have received much attention due to their wide applications like a catalysis support. Therefore, in this study, Mg-Al/ LDH was synthetized by coprecipitation method and then platinum was impregned on it, in order to enhance its catalytic activity. Two methods of impregnation were used, the first one, called incipient wet impregnation and the second one was developed by continuous agitation of LDH in contact with chloroplatinic acid solution for 24 h. The support impregnated was analyzed by X-ray diffraction, FTIR and SEM. Finally, the oxidation of cyanide ion was performed by preparing synthetic solutions of sodium cyanide (NaCN) with an initial concentration of 500 mg/L at pH 10,5 and air flow of 180 NL/h. After 8 hours of treatment, an 80% of oxidation of ion cyanide was achieved.

Keywords: catalysis, cyanide, LDHs, mining

Procedia PDF Downloads 146

Authors: Vera Varazashvili, Murman Tsarakhov, Tamar Mirianashvili, Teimuraz Pavlenishvili, Tengiz Machaladze, Mzia Khundadze

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Standard Gibbs energy of formation ΔGfor(298.15) of lanthanide-iron double oxides of garnet-type crystal structure R3Fe5O12 - RIG (R – are rare earth ions) from initial oxides are evaluated. The calculation is based on the data of standard entropies S298.15 and standard enthalpies ΔH298.15 of formation of compounds which are involved in the process of garnets synthesis. Gibbs energy of formation is presented as temperature function ΔGfor(T) for the range 300-1600K. The necessary starting thermodynamic data were obtained from calorimetric study of heat capacity and by using the semi-empirical method for calculation of ΔH298.15 (formation). Thermodynamic functions for standard temperature – enthalpy, entropy and Gibbs energy - are recommended as reference data for technological evaluations. Through the isostructural series of rare earth-iron garnets the correlation between thermodynamic properties and characteristics of lanthanide ions are elucidated.

Keywords: calorimetry, entropy, heat capacity, Gibbs energy of formation, rare earth iron garnets

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Authors: Muhammad Tariq, Hammad Tahir, Fawwad Mahmood Butt

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Purpose: This study attempts to examine the best forecasting methodologies in the time series. The time series forecasting models such as VAR, ARCH and the ARMA are considered for the analysis. Methodology: The Bench Marks or the parameters such as Adjusted R square, F-stats, Durban Watson, and Direction of the roots have been critically and empirically analyzed. The empirical analysis consists of time series data of Consumer Price Index and Closing Stock Price. Findings: The results show that the VAR model performed better in comparison to other models. Both the reliability and significance of VAR model is highly appreciable. In contrary to it, the ARCH model showed very poor results for forecasting. However, the results of ARMA model appeared double standards i.e. the AR roots showed that model is stationary and that of MA roots showed that the model is invertible. Therefore, the forecasting would remain doubtful if it made on the bases of ARMA model. It has been concluded that VAR model provides best forecasting results. Practical Implications: This paper provides empirical evidences for the application of time series forecasting model. This paper therefore provides the base for the application of best time series forecasting model.

Keywords: forecasting, time series, auto regression, ARCH, ARMA

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Authors: Valeria Butera, Norihisa Fukaya, Jun-Chu Choi, Kazuhiko Sato, Yoong-Kee Choe

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Several silicon dioxide sources can react with dimethyl carbonate (DMC) in presence of alkali bases catalysts to ultimately produce tetramethoxysilane (TMOS). Experimental findings suggested that the reaction proceeds through several steps in which the first molecule of DMC is converted to dimethylsilyloxide (DMOS) and CO₂. Following the same mechanistic steps, a second molecule of DMC reacts with the DMOS to afford the final product TMOS. Using a cluster model approach, a quantum-mechanical investigation of the first part of the reaction leading to DMOS formation is reported with a twofold purpose: (1) verify the viability of the reaction mechanism proposed on the basis of experimental evidences .(2) compare the behaviors of three different alkali hydroxides MOH, where M=Li, K and Cs, to determine whether diverse ionic radius and charge density can be considered responsible for the observed differences in reactivity. Our findings confirm the observed experimental trend and furnish important information about the effective role of the alkali hydroxides giving an explanation of the different catalytic activity of the three metal cations.

Keywords: Alcoxysilanes production, cluster model approach, DFT, DMC conversion

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Authors: Emmanuel A. Oriaifo, Noel Perera, Alan Guy, Pak. S. Leung, Kian T. Tan

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Concerns on corrosion and effective coating protection of double hull tankers and bulk carriers in service have been raised especially in water ballast tanks (WBTs). Test protocols/methodologies specifically that which is incorporated in the International Maritime Organisation (IMO), Performance Standard for Protective Coatings for Dedicated Sea Water ballast tanks (PSPC) are being used to assess and evaluate the performance of the coatings for type approval prior to their application in WBTs. However, some of the type approved coatings may be applied as very thick films to less than ideally prepared steel substrates in the WBT. As such films experience hygrothermal cycling from operating and environmental conditions, they become embrittled which may ultimately result in cracking. This embrittlement of the coatings is identified as an undesirable feature in the PSPC but is not mentioned in the test protocols within it. There is therefore renewed industrial research aimed at understanding this issue in order to eliminate cracking and achieve the intended coating lifespan of 15 years in good condition. This paper will critically review test protocols currently used for assessing and evaluating coating performance, particularly the IMO PSPC.

Keywords: corrosion test, hygrothermal cycling, coating test protocols, water ballast tanks

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Authors: Abdellahi Cheikh

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With the emergence of quantum computers with very powerful capabilities, the security of the exchange of shared keys between two interlocutors poses a big problem in terms of the rapid development of technologies such as computing power and computing speed. Therefore, the Diffie-Hellmann (DH) algorithm is more vulnerable than ever. No mechanism guarantees the security of the key exchange, so if an intermediary manages to intercept it, it is easy to intercept. In this regard, several studies have been conducted to improve the security of key exchange between two interlocutors, which has led to interesting results. The modification made on our model Diffie-Hellman-RSA-AES (DRA), which encrypts the information exchanged between two users using the three-encryption algorithms DH, RSA and AES, by using stenographic photos to hide the contents of the p, g and ClesAES values that are sent in an unencrypted state at the level of DRA model to calculate each user's public key. This work includes a comparative study between the DRA model and all existing solutions, as well as the modification made to this model, with an emphasis on the aspect of reliability in terms of security. This study presents a simulation to demonstrate the effectiveness of the modification made to the DRA model. The obtained results show that our model has a security advantage over the existing solution, so we made these changes to reinforce the security of the DRA model.

Keywords: Diffie-Hellmann, DRA, RSA, advanced encryption standard

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Authors: Antonis Constantinides, Christos Yiallouras, Christakis Damianou

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The coaxial transformer-coupled push-pull circuitry has been used widely in HF and VHF amplifiers for many decades without significant changes in the topology of the transformers. Basic changes over the years concerned the construction and turns ratio of the transformers as has been imposed upon the newer technologies active devices demands. The balun transmission line transformers applied in push-pull amplifiers enable input/output impedance transformation, but are mainly used to convert the balanced output into unbalanced and the input unbalanced into balanced. A simple and affordable alternative solution over the traditional coaxial transformer is the coreless planar balun. A key advantage over the traditional approach lies in the high specifications repeatability; simplifying the amplifier construction requirements as the planar balun constitutes an integrated part of the PCB copper layout. This paper presents the performance analysis of a planar LDMOS MRFE6VP5600 Push-Pull amplifier that enables robust operation in Band III, DVB-T, DVB-T2 standards but functions equally well in Band II, for DRM+ new generation transmitters.

Keywords: amplifier, balun, complex impedance, LDMOS, planar-transformers

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Authors: Shreya Banerjee, Prasanta K. Panigrahi

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The three-way distributive entanglement is shown to be related to the parallelism of vectors. Using a measurement-based approach a set of 2−dimensional vectors is formed, representing the post-measurement states of one of the parties. These vectors originate at the same point and have an angular distance between them. The area spanned by a pair of such vectors is a measure of the entanglement of formation. This leads to a geometrical manifestation of the 3−tangle in 2−dimensions, from inequality in the area which generalizes for n− qubits to reveal that the n− tangle also has a planar structure. Quantifying the genuine n−party entanglement in every 1|(n − 1) bi-partition it is shown that the genuine n−way entanglement does not manifest in n− tangle. A new quantity geometrically similar to 3−tangle is then introduced that represents the genuine n− way entanglement. Extending the formalism to 3− qutrits, the nonlocality without entanglement can be seen to arise from a condition under which the post-measurement state vectors of a separable state show parallelism. A connection to nontrivial sum uncertainty relation analogous to Maccone and Pati uncertainty relation is then presented using decomposition of post-measurement state vectors along parallel and perpendicular direction of the pre-measurement state vectors. This study opens a novel way to understand multiparty entanglement in qubit and qudit systems.

Keywords: Geometry of quantum entanglement, Multipartite and distributive entanglement, Parallelism of vectors , Tangle

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Authors: Nidal H. Abu-Zahra, Aruna P. Wanninayake

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Copper Oxide (CuO) is a p-type semiconductor with a band gap energy of 1.5 eV, this is close to the ideal energy gap of 1.4 eV required for solar cells to allow good solar spectral absorption. The inherent electrical characteristics of CuO nano particles make them attractive candidates for improving the performance of polymer solar cells when incorporated into the active polymer layer. The UV-visible absorption spectra and external quantum efficiency of P3HT/PC70BM solar cells containing different weight percentages of CuO nano particles showed a clear enhancement in the photo absorption of the active layer, this increased the power conversion efficiency of the solar cells by 24% in comparison to the reference cell. The short circuit current of the reference cell was found to be 5.234 mA/cm2 and it seemed to increase to 6.484 mA/cm2 in cells containing 0.6 mg of CuO NPs; in addition the fill factor increased from 61.15% to 68.0%, showing an enhancement of 11.2%. These observations suggest that the optimum concentration of CuO nano particles was 0.6 mg in the active layer. These significant findings can be applied to design high-efficiency polymer solar cells containing inorganic nano particles.

Keywords: copper oxide nanoparticle, UV-visible spectroscopy, polymer solar cells, P3HT/PCBM

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Authors: M. R. Phadatare, J. V. Meshram, S. H. Pawar

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Conversion of electromagnetic energy into heat by nanoparticles (NPs) has the potential to be a powerful, non-invasive technique for biomedical applications such as magnetic fluid hyperthermia, drug release, disease treatment and remote control of single cell functions, but poor conversion efficiencies have hindered practical applications so far. In this paper, an attempt has been made to increase the efficiency of magnetic, thermal induction by NPs. To increase the efficiency of magnetic, thermal induction by NPs, one can take advantage of the exchange coupling between a magnetically hard core and magnetically soft shell to tune the magnetic properties of the NP and maximize the specific absorption rate, which is the gauge of conversion efficiency. In order to examine the tunability of magnetocrystalline anisotropy and its magnetic heating power, a representative magnetically hard material (CoFe₂O₄) has been coupled to a soft material (Ni₀.₅Zn₀.₅Fe₂O₄). The synthesized NPs show specific absorption rates that are of an order of magnitude larger than the conventional one.

Keywords: magnetic nanoparticles, surface functionalization of magnetic nanoparticles, magnetic fluid hyperthermia, specific absorption rate

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Authors: N. Larbi, F. Debbat

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Wireless communication systems have changed dramatically and shown spectacular evolution over the past two decades. These radio technologies are engaged in a quest endless high-speed transmission coupled to a constant need to improve transmission quality. Various radio communication systems being developed use code division multiple access (CDMA) technique. This work analyses a hybrid honey bees mating optimization algorithm (HBMO) applied to multiuser detection (MuD) in CDMA communication systems. The HBMO is a swarm-based optimization algorithm, which simulates the mating process of real honey bees. We apply a hybridization of HBMO with simulated annealing (SA) in order to improve the solution generated by the HBMO. Simulation results show that the detection based on Hybrid HBMO, in term of bit error rate (BER), is viable option when compared with the classic detectors from literature under Rayleigh flat fading channel.

Keywords: BER, DS-CDMA multiuser detection, genetic algorithm, hybrid HBMO, simulated annealing

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Authors: Nisha Deopa, Allam Srinivasa Rao

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Quaternary potassium lead alumino borate (KPbAlB) glasses doped with different concentration of Eu³⁺ ions have been synthesized by melt quench technique and characterized by X-ray diffraction (XRD), Scanning electron microscope (SEM), Photoluminescence (PL), Time-resolved photoluminescence (TRPL) and CIE-chromaticity co-ordinates to study their luminescence behavior. A broad hump was observed in XRD spectrum confirms glassy nature of as-prepared glasses. By using Judd-Ofelt (J-O) theory, various radiative parameters for the prominent fluorescent levels of Eu³⁺ have been investigated. The intense emission peak was observed at 613 nm (⁵D₀→⁷F₂) under 393 nm excitation, matches well with the excitation of n-UV LED chips. The decay profiles observed for ⁵D₀ level were exponential for lower Eu³⁺ ion concentration while non-exponential for higher concentration, which may be due to efficient energy transfer between Eu³⁺-Eu³⁺ through cross relaxation and subsequent quenching observed. From the emission cross-sections, branching ratios, quantum efficiency and CIE coordinates, it was concluded that 7 mol % of Eu³⁺ ion concentration (glass B) is optimum in KPbAlB glasses for photonic device application.

Keywords: energy transfer, glasses, J-O parameters, photoluminescence

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Authors: BenedictI Ita, Etido P. Inyang

Abstract:

In this work, the resolutions of the N-dimensional Schrödinger equation with the screened modified Kratzerplus inversely quadratic Yukawa potential (SMKIQYP) have been obtained with the Greene-Aldrich approximation scheme using the Nikiforov-Uvarov method. The eigenvalues and the normalized eigenfunctions are obtained. We then apply the energy spectrum to study four (HCl, N₂, NO, and CO) diatomic molecules. The results show that the energy spectra of these diatomic molecules increase as quantum numbers increase. The energy equation was also used to calculate the partition function and other thermodynamic properties. We predicted the partition function of CO and NO. To check the accuracy of our work, the special case (Modified Kratzer and screened Modified Kratzer potentials) of the collective potential energy eigenvalues agrees excellently with the existing literature.

Keywords: Schrödinger equation, Nikiforov-Uvarov method, modified screened Kratzer, inversely quadratic Yukawa potential, diatomic molecules

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Authors: Rupak Kumar Sarma, Ratul Saikia

Abstract:

Macrophytes encompass major functional group in eutrophic wetland ecosystems. As a key functional element of freshwater lakes, they play a crucial role in regulating various wetland biogeochemical cycles, as well as maintain the biodiversity at the ecosystem level. The high carbon-rich underground biomass of macrophyte populations may harbour diverse microbial community having significant potential in maintaining different biogeochemical cycles. The present investigation was designed to study the macrophyte-microbe interaction in coupled nitrification and denitrification, considering Deepor Beel Lake (a Ramsar conservation site) of North East India as a model eutrophic system. Highly eutrophic sites of Deepor Beel were selected based on sediment oxygen demand and inorganic phosphorus and nitrogen (P&N) concentration. Sediment redox potential and depth of the lake was chosen as the benchmark for collecting the plant and sediment samples. The average highest depth in winter (January 2016) and summer (July 2016) were recorded as 20ft (6.096m) and 35ft (10.668m) respectively. Both sampling depth and sampling seasons had the distinct effect on variation in macrophyte community composition. Overall, the dominant macrophytic populations in the lake were Nymphaea alba, Hydrilla verticillata, Utricularia flexuosa, Vallisneria spiralis, Najas indica, Monochoria hastaefolia, Trapa bispinosa, Ipomea fistulosa, Hygrorhiza aristata, Polygonum hydropiper, Eichhornia crassipes and Euryale ferox. There was a distinct correlation in the variation of major sediment physicochemical parameters with change in macrophyte community compositions. Quantitative estimation revealed an almost even accumulation of nitrate and nitrite in the sediment samples dominated by the plant species Eichhornia crassipes, Nymphaea alba, Hydrilla verticillata, Vallisneria spiralis, Euryale ferox and Monochoria hastaefolia, which might have signified a stable nitrification and denitrification process in the sites dominated by the selected aquatic plants. This was further examined by a systematic analysis of microbial populations through culture dependent and independent approach. Culture-dependent bacterial community study revealed the higher population of nitrifiers and denitrifiers in the sediment samples dominated by the six macrophyte species. However, culture-independent study with bacterial 16S rDNA V3-V4 metagenome sequencing revealed the overall similar type of bacterial phylum in all the sediment samples collected during the study. Thus, there might be the possibility of uneven distribution of nitrifying and denitrifying molecular markers among the sediment samples collected during the investigation. The diversity and abundance of the nitrifying and denitrifying molecular markers in the sediment samples are under investigation. Thus, the role of different aquatic plant functional types in microorganism mediated nitrogen cycle coupling could be screened out further from the present initial investigation.

Keywords: denitrification, macrophyte, metagenome, microorganism, nitrification

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