Search results for: characteristic impedance exponential nonuniform transmission line

Authors: Barenten Suciu

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An electrical generator able to harness energy from the water waves and designed as a double-cone geared motor-generator (DCGMG), is proposed and theoretically investigated. Similar to a differential gear mechanism, used in the transmission system of the auto vehicle wheels, an angular speed differential is created between the cones rolling on two concentric circular rails. Water wave acting on the floating DCGMG produces and a gear-box amplifies the speed differential to gain sufficient torque for power generation. A model that allows computation of the speed differential, torque, and power of the DCGMG is suggested. Influence of various parameters, regarding the construction of the DCGMG, as well as the contact between the double-cone and rails, on the electro-mechanical output, is emphasized. Results obtained indicate that the generated electrical power can be increased by augmenting the mass of the double-cone, the span of the rails, the apex angle of the cones, the friction between cones and rails, the amplification factor of the gear-box, and the efficiency of the motor-generator. Such findings are useful to formulate a design methodology for the proposed wave-powered generator.

Keywords: amplification of angular speed differential, circular concentric rails, double-cone, wave-powered electrical generator

Procedia PDF Downloads 156

Authors: M. D. H. Beg, John O. Akindoyo, Suriati Ghazali, Nitthiyah Jeyaratnam

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Over the period of time, several approaches have been undertaken to mitigate the challenges associated with bone regeneration. This includes but not limited to xenografts, allografts, autografts as well as artificial substitutions like bioceramics, synthetic cements and metals. The former three techniques often come along with peculiar limitation and problems such as morbidity, availability, disease transmission, collateral site damage or absolute rejection by the body as the case may be. Synthetic routes remain the only feasible alternative option for treatment of bone defects. Hydroxyapatite (HA) is very compatible and suitable for this application. However, most of the common methods for HA synthesis are either expensive, complicated or environmentally unfriendly. Interestingly, extraction of HA from bio-wastes have been perceived not only to be cost effective, but also environment friendly. In this research, HA was synthesized from bio-waste: namely bovine bones through three different methods which are hydrothermal chemical processes, ultrasound assisted synthesis and ordinary calcination techniques. Structure and property analysis of the HA was carried out through different characterization techniques such as TGA, FTIR, and XRD. All the methods applied were able to produce HA with similar compositional properties to biomaterials found in human calcified tissues. Calcination process was however observed to be more efficient as it eliminated all the organic components from the produced HA. The HA synthesized is unique for its minimal cost and environmental friendliness. It is also perceived to be suitable for tissue and bone engineering applications.

Keywords: hydroxyapatite, bone, calcination, biowaste

Procedia PDF Downloads 249

Authors: Nino Grigolaia

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Introduction: The article discusses the experience of the EU in the social field, analyzes the peculiarities of the functioning of the social system in Georgia, and reveals the priority and importance of social policy. Methodology: Different research methods are applied in the presented paper. There are used induction, deduction, analysis, synthesis, analogy, correlation, and statistical observation methodologies in the work. Main Findings: Based on the analysis of social security reforms in Georgia, the main systematic problems are detected, the recommendations on social security system components, integration of the social security field in the unified insurance system, the formation of the national social system, perfection of the legislative, regulatory framework of social protection, adoption of foreign experience are developed in the article. Conclusion: The article concludes that the social protection system in Georgia is at an early stage of development, with the significant impact of factors such as high level of unemployment, low pensions, a large number of families living under the poverty line, and other ones. Accordingly, it is well-established that the study of the social security problem in Georgia is still actual. Based on the analysis, appropriate suggestions in the field of social security are made, and relevant recommendations are proposed.

Keywords: social security, social system, social policy, social security models

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Authors: M. Yushalify Misro, Ahmad Ramli, Jamaludin M. Ali

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Bezier curves have useful properties for path generation problem, for instance, it can generate the reference trajectory for vehicles to satisfy the path constraints. Both algorithms join cubic Bezier curve segment smoothly to generate the path. Some of the useful properties of Bezier are curvature. In mathematics, the curvature is the amount by which a geometric object deviates from being flat, or straight in the case of a line. Another extrinsic example of curvature is a circle, where the curvature is equal to the reciprocal of its radius at any point on the circle. The smaller the radius, the higher the curvature thus the vehicle needs to bend sharply. In this study, we use Bezier curve to fit highway-like curve. We use the different approach to finding the best approximation for the curve so that it will resemble highway-like curve. We compute curvature value by analytical differentiation of the Bezier Curve. We will then compute the maximum speed for driving using the curvature information obtained. Our research works on some assumptions; first the Bezier curve estimates the real shape of the curve which can be verified visually. Even, though, the fitting process of Bezier curve does not interpolate exactly on the curve of interest, we believe that the estimation of speed is acceptable. We verified our result with the manual calculation of the curvature from the map.

Keywords: speed estimation, path constraints, reference trajectory, Bezier curve

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Authors: Deepak Choudhary

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COEP-Microgrid, a project by the students of College of Engineering Pune aims at establishing a micro grid in the college campus serving as a living laboratory for research and development of novel grid technologies. Proposed micro grid has an AC-bus and DC-bus, interconnected together with a tie line DC-AC converter. In grid-connected mode AC bus of microgrid is synchronized with utility grid. Synchronization with utility grid requires grid and AC bus to have synchronism in frequency, phase sequence and voltage. Power flow requires phase difference between grid and AC bus. Control System is required to effectively regulate power flow between the grid and AC bus. The grid synchronizing control system is composed of frequency and phase control for regulated power flow and voltage control system for reduction of reactive power flow. The control system involves automatic active power flow control. It takes the feedback of DC link Capacitor and changes the power angle accordingly. Control system incorporating voltage, phase and power control was developed for grid-tie inverter. This paper discusses the design, simulation and practical implementation of control system described in various micro grid scenarios.

Keywords: microgrid, Grid-tie inverter, voltage control, automatic power control

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Authors: Dawei Li, Cheng Liu, Yiteng Liu

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This paper introduces an embedded digital image system for Chinese space environment vertical exploration sounding rocket. In order to record the flight status of the sounding rocket as well as the payloads, an onboard embedded image processing system based on ADV212, a JPEG2000 compression chip, is designed in this paper. Since the sounding rocket is not designed to be recovered, all image data should be transmitted to the ground station before the re-entry while the downlink band used for the image transmission is only about 600 kbps. Under the same condition of compression ratio compared with other algorithm, JPEG2000 standard algorithm can achieve better image quality. So JPEG2000 image compression is applied under this condition with a limited downlink data band. This embedded image system supports lossless to 200:1 real time compression, with two cameras to monitor nose ejection and motor separation, and two cameras to monitor boom deployment. The encoder, ADV7182, receives PAL signal from the camera, then output the ITU-R BT.656 signal to ADV212. ADV7182 switches between four input video channels as the program sequence. Two SRAMs are used for Ping-pong operation and one 512 Mb SDRAM for buffering high frame-rate images. The whole image system has the characteristics of low power dissipation, low cost, small size and high reliability, which is rather suitable for this sounding rocket application.

Keywords: ADV212, image system, JPEG2000, sounding rocket

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Authors: Long Cheng, Tong He, Iraj Mantegh, Wen-Fang Xie

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Path planning is essential for UAVs (Unmanned Aerial Vehicle) with autonomous navigation in unknown environments. In this paper, an adaptive probabilistic sampling algorithm is proposed for the GPS-denied environment, which can be utilized for autonomous navigation system of multiple UAVs in a dynamically-changing structured environment. This method can be used for Unmanned Aircraft Systems Traffic Management (UTM) solutions and in autonomous urban aerial mobility, where a number of platforms are expected to share the airspace. A path network is initially built off line based on available environment map, and on-board sensors systems on the flying UAVs are used for continuous situational awareness and to inform the changes in the path network. Simulation results based on MATLAB and Gazebo in different scenarios and algorithms performance measurement show the high efficiency and accuracy of the proposed technique in unknown environments.

Keywords: path planning, adaptive probabilistic sampling, obstacle avoidance, multiple unmanned aerial vehicles, unknown environments

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Authors: Vivienne Langhorne, Helen Sharpe

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Body dissatisfaction begins developing in middle childhood, with wide-ranging implications for mental health and well-being. Previous research on parent behavior has focused on the role of explicit parent behaviors in adolescent and young adult body dissatisfaction, leaving a gap in understanding how implicit parent behaviors relate to body dissatisfaction in childhood. The current study investigated how implicit parent behavior (such as modeling own body dissatisfaction and dieting) relates to parent and child body dissatisfaction. It was hypothesized that implicit behavior would be directly related to parent and child body dissatisfaction and mediate the relationship between the two. Furthermore, this study aimed to examine child gender as a potential moderator in this mediation, as research shows that boys and girls experience body dissatisfaction differently. This study analyzed survey responses on parent body dissatisfaction, implicit behavior, and child body dissatisfaction measures from a sample of 166 parent-child dyads with children between the ages of 6 to 9 years old. Regression analyses revealed that parent body dissatisfaction is related to both parent-implicit behavior and child body dissatisfaction. However, implicit behavior did not mediate the relationship between the two body dissatisfaction variables. Additionally, the results of moderated mediation indicated there were no child gender differences in the strength of the association between parental implicit behaviors and child body dissatisfaction. These findings highlight the need for further research into the mechanisms behind parent and child body dissatisfaction to better understand the process through which intergenerational transmission occurs.

Keywords: body dissatisfaction, implicit behaviour, middle childhood, parenting

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Authors: Cristian Viespe, Dana Miu

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Surface acoustic wave (SAW) sensors with nanoparticles (NPs) of various dimensions and concentrations embedded in different types of polymer sensing films for detecting volatile organic compounds (VOCs) were studied. The sensors were ‘delay line’ type with a center frequency of 69.4 MHz on ST-X quartz substrates. NPs with different diameters of 7 nm or 13 nm were obtained by laser ablation with lasers having 5 ns or 10 ps pulse durations, respectively. The influence of NPs dimensions and concentrations on sensor properties such as frequency shift, sensitivity, noise and response time were investigated. To the best of our knowledge, the influence of NP dimensions on SAW sensor properties with has not been investigated. The frequency shift and sensitivity increased with increasing NP concentration in the polymer for a given NP dimension and with decreasing NP diameter for a given concentration. The best performances were obtained for the smallest NPs used. The SAW sensor with NPs of 7 nm had a limit of detection (LOD) of 65 ppm (almost five times better than the sensor with polymer alone), and a response time of about 9 s for ethanol.

Keywords: surface acoustic wave sensor, nanoparticles, volatile organic compounds, laser ablation

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Authors: M. Salmanpour, O. Nourani Zonouz

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In this research, a numerical simulation of an Electrohydrodynamic (EHD) actuator’s effects on the flow around a square cylinder by using a finite volume method has been investigated. This is one of the newest ways for controlling the fluid flows. Two plate electrodes are flush-mounted on the surface of the cylinder and one wire electrode is placed on the line with zero angle of attack relative to the stagnation point and excited with DC power supply. The discharge produces an electric force and changes the local momentum behaviors in the fluid layers. For this purpose, after selecting proper domain and boundary conditions, the electric field relating to the problem has been analyzed and then the results in the form of electrical body force have been entered in the governing equations of fluid field (Navier-Stokes equations). The effect of ionic wind resulted from the Electrohydrodynamic actuator, on the velocity, pressure and the wake behind cylinder has been considered. According to the results, it is observed that the fluid flow accelerates in the nearest wall of the frontal half of the cylinder and the pressure difference between frontal and hinder cylinder is increased.

Keywords: CFD, corona discharge, electro hydrodynamics, flow around square cylinders, simulation

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Authors: Juiwen Liang, Choliang Chung

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In this study, the silicon-base oxide nanofibers with hollow structure were prepared using single-nozzle electrospinning and heat treatment. Firstly, precursor solution was prepared: the Polyvinylpyrrolidone (PVP) and Tetraethyl orthosilicate (TEOS) dissolved in ethanol and to make sure the concentration of solution in appropriate using single-nozzle electrospinning to produce the nanofibers. Secondly, control morphology of the electrostatic spinning nanofibers was conducted, and design the temperature profile to created hollow nanofibers, exploring the morphology and properties of nanofibers. The characterized of nanofibers, following instruments were used: Atomic force microscopy (AFM), Field Emission Scanning Electron Microscope (FE-SEM), Transmission electron microscopy (TEM), Photoluminescence (PL), X-ray Diffraction (XRD). The AFM was used to scan the nanofibers, and 3D Graphics were applied to explore the surface morphology of fibers. FE-SEM and TEM were used to explore the morphology and diameter of nanofibers and hollow nanofiber. The excitation and emission spectra explored by PL. Finally, XRD was used for identified crystallization of ceramic nanofibers. Using electrospinning technique followed by subsequent heat treatment, we have successfully prepared silicon-base oxide nanofibers with hollow structure. Thus, the microstructure and morphology of electrostatic spinning silicon-base oxide hollow nanofibers were explored. Major characteristics of the nanofiber in terms of crystalline, optical properties and crystal structure were identified.

Keywords: electrospinning, single-nozzle, hollow, nanofibers

Procedia PDF Downloads 350

Authors: Beate Englich, Linda Schlittenbauer, Christiane Pfeifer, Isabel Kratochvil, Michael Borte, Gabriele I. Stangl, Martin von Bergen, Thorsten Reemtsma, Irina Lehmann, Kristin M. Junge

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The worldwide production of endocrine disrupting compounds (EDC) has risen dramatically over the last decades, as so has the prevalence for obesity. Many EDCs are believed to contribute to this obesity epidemic, by enhancing adipogenesis or disrupting relevant metabolism. This effect is most tremendous in the early prenatal period when priming effects find a highly vulnerable time window. Therefore, we investigate the impact of parabens on childhood overweight development and adipogenesis in general. Parabens are ester of 4-hydroxy-benzoic acid and part of many cosmetic products or food packing. Therefore, ubiquitous exposure can be found in the westernized world, with exposure already starting during the sensitive prenatal period. We assessed maternal cosmetic product consumption, prenatal paraben exposure and infant BMI z-scores in the prospective German LINA cohort. In detail, maternal urinary concentrations (34 weeks of gestation) of methyl paraben (MeP), ethyl paraben (EtP), n-propyl paraben (PrP) and n-butyl paraben (BuP) were quantified using UPLC-MS/MS. Body weight and height of their children was assessed during annual clinical visits. Further, we investigated the direct influence of those parabens on adipogenesis in-vitro using a human mesenchymal stem cell (MSC) differentiation assay to mimic a prenatal exposure scenario. MSC were exposed to 0.1 – 50 µM paraben during the entire differentiation period. Differentiation outcome was monitored by impedance spectrometry, real-time PCR and triglyceride staining. We found that maternal cosmetic product consumption was highly correlated with urinary paraben concentrations at pregnancy. Further, prenatal paraben exposure was linked to higher BMI Z-scores in children. Our in-vitro analysis revealed that especially the long chained paraben BuP stimulates adipogenesis by increasing the expression of adipocyte specific genes (PPARγ, ADIPOQ, LPL, etc.) and triglyceride storage. Moreover, we found that adiponectin secretion is increased whereas leptin secretion is reduced under BuP exposure in-vitro. Further mechanistic analysis for receptor binding and activation of PPARγ and other key players in adipogenesis are currently in process. We conclude that maternal cosmetic product consumption is linked to prenatal paraben exposure of children and contributes to the development of infant overweight development by triggering key pathways of adipogenesis.

Keywords: adipogenesis, endocrine disruptors, paraben, prenatal exposure

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Authors: Sarthak Karki, Haribansha Timalsina

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Kanchan Arsenic Filter is an economical low cost and termed the most efficient arsenic removal filter system in South Asian countries such as Nepal. But when the effluent quality was evaluated, it was seen to possess a lower removal rate of arsenite species. In addition to that, greater pathogenic growth and loss in overall efficacy with time due to precipitation of iron sulphates were the further complications. This brings the health issue on the front line as millions of people rely on groundwater sources for general water necessities. With this paper, we analyzed the mechanisms and changes in the efficiency of the extant filter system when integrated with activated laterite and hair column beds, plus an additional charcoal layer for inhibiting pathogen colonies. Hair column have rich keratin protein that binds with arsenic species, and similarly, raw laterite has huge deposits of iron and aluminum, all of these factors helping to remove heavy metal contaminants from water sources. Further study on the commercialized mass production of the new proposed filter and versatility analysis is required.

Keywords: laterite, charcoal, arsenic removal, hair column

Procedia PDF Downloads 88

Authors: Nareshkumar Harale, B. B. Meshram

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The continued exponential growth of successful cyber intrusions against today’s businesses has made it abundantly clear that traditional perimeter security measures are no longer adequate and effective. We evolved the network trust architecture from trust-untrust to Zero-Trust, With Zero Trust, essential security capabilities are deployed in a way that provides policy enforcement and protection for all users, devices, applications, data resources, and the communications traffic between them, regardless of their location. Information exchange over the Internet, in spite of inclusion of advanced security controls, is always under innovative, inventive and prone to cyberattacks. TCP/IP protocol stack, the adapted standard for communication over network, suffers from inherent design vulnerabilities such as communication and session management protocols, routing protocols and security protocols are the major cause of major attacks. With the explosion of cyber security threats, such as viruses, worms, rootkits, malwares, Denial of Service attacks, accomplishing efficient and effective intrusion detection and prevention is become crucial and challenging too. In this paper, we propose a design and analysis model for next generation network intrusion detection and protection system as part of layered security strategy. The proposed system design provides intrusion detection for wide range of attacks with layered architecture and framework. The proposed network intrusion classification framework deals with cyberattacks on standard TCP/IP protocol, routing protocols and security protocols. It thereby forms the basis for detection of attack classes and applies signature based matching for known cyberattacks and data mining based machine learning approaches for unknown cyberattacks. Our proposed implemented software can effectively detect attacks even when malicious connections are hidden within normal events. The unsupervised learning algorithm applied to network audit data trails results in unknown intrusion detection. Association rule mining algorithms generate new rules from collected audit trail data resulting in increased intrusion prevention though integrated firewall systems. Intrusion response mechanisms can be initiated in real-time thereby minimizing the impact of network intrusions. Finally, we have shown that our approach can be validated and how the analysis results can be used for detecting and protection from the new network anomalies.

Keywords: network intrusion detection, network intrusion prevention, association rule mining, system analysis and design

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Authors: Mariam Dianat Sabet Gilani, Lars M. Blank, Birgitta E. Ebert

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Plant-derived lupane-type, pentacyclic triterpenoids are biologically active compounds that are highly interesting for applications in medical, pharmaceutical, and cosmetic industries. Due to the low abundance of these valuable compounds in their natural sources, and the environmentally harmful downstream process, alternative production methods, such as microbial cell factories, are investigated. Engineered Saccharomyces cerevisiae strains, harboring the heterologous genes for betulinic acid synthesis, can produce up to 2 g L-1 triterpenoids, showing high potential for large-scale production of triterpenoids. One limitation of the microbial synthesis is the intracellular product accumulation. It not only makes cell disruption a necessary step in the downstream processing but also limits productivity and product yield per cell. To overcome these restrictions, the aim of this study is to develop an in-situ extraction method, which extracts triterpenoids into a second organic phase. Such a continuous or sequential product removal from the biomass keeps the cells in an active state and enables extended production time or biomass recycling. After screening of twelve different solvents, selected based on product solubility, biocompatibility, as well as environmental and health impact, isopropyl myristate (IPM) was chosen as a suitable solvent for in-situ product removal from S. cerevisiae. Impedance-based single-cell analysis and off-gas measurement of carbon dioxide emission showed that cell viability and physiology were not affected by the presence of IPM. Initial experiments demonstrated that after the addition of 20 vol % IPM to cultures in the stationary phase, 40 % of the total produced triterpenoids were extracted from the cells into the organic phase. In future experiments, the application of IPM in a repeated batch process will be tested, where IPM is added at the end of each batch run to remove triterpenoids from the cells, allowing the same biocatalysts to be used in several sequential batch steps. Due to its high biocompatibility, the amount of IPM added to the culture can also be increased to more than 20 vol % to extract more than 40 % triterpenoids in the organic phase, allowing the cells to produce more triterpenoids. This highlights the potential for the development of a continuous large-scale process, which allows biocatalysts to produce intracellular products continuously without the necessity of cell disruption and without limitation of the cell capacity.

Keywords: betulinic acid, biocompatible solvent, in-situ extraction, isopropyl myristate, process development, secondary metabolites, triterpenoids, yeast

Procedia PDF Downloads 153

Authors: Funmilayo Lanrewaju Amao, Amos Olusegun Amao, Odetoye Adeola Sunday, Joseph Joshua Olu

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There is a high magnitude of housing inadequacy in urban centers in Nigeria. This is manifested in quantitative and qualitative terms. Severe overcrowding and insanitary physical environment characterize the housing in the urban centers. The culminating effect of this is the growth of slum areas. This paper takes a critical look at inter-allia history and anatomy, general characteristic, present condition, root causes, official responses and reactions, possible solution and advocacy housing in central city slum of Ibadan. It also examines slum development and consequent deviant behaviors in the inner-city neighborhoods of Ibadan, the capital city of Oyo State, Nigeria. Residing there are many underemployed and unemployed individuals, these are miscreants who are generally socially frustrated. The activities of this group of people are a cause of concern. Deleterious and anti-social behaviors such as prostitution and house burglary are commonplace in the neighborhoods. The paper examines building conditions in the neighborhoods and the nexus with the deviant behavior of the inhabitants. The paper affirms that there is monumental deficiency in housing quality, while the design and the arrangement of the buildings into spatial units significantly influence the behavior of the residents. The paper suggests a two-prong approach in dealing with the situation. This involves urban renewal and slum upgrading programmes on the one hand, and an improvement in the socio-economic circumstances of the inhabitants, especially an increase in employment opportunity on the other.

Keywords: slum, behavior, housing, poverty, environmental degeneration

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Authors: Tachita Vlad-Bubulac, Ionela-Daniela Carja, Diana Serbezeanu, Corneliu Hamciuc, Vicente Javier Forrat Perez

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The present work describes the preparation of new organophosphorus compounds with high content of phosphorus followed by the incorporation of these compounds into epoxy resin systems in order to investigate the phosphorus effect in terms of thermal stability, flame-retardant and mechanical properties of modified epoxy resins. Thus, two new organophosphorus compounds have been synthesized and fully characterized. 6-Oxido-6H-dibenz[c,e][1,2]oxaphosphorinyl-phenylcarbinol has been prepared by the addition reaction of P–H group of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to carbonyl group of benzaldehyde. By treating the phenylcarbinol derivative with POCl3 a new phosphorus compound was obtained, having a content of 12.227% P. The organophosphorus compounds have been purified by recrystallization while their chemical structures have been confirmed by melting point measurements, FTIR and HNMR spectroscopies. In the next step various flame-retardant epoxy resins with different content of phosphorus have been prepared starting from a commercial epoxy resin and using dicyandiamide (DICY) as a latent curing agent in the presence of an accelerator. Differential scanning calorimetry (DSC) has been applied to investigate the behavior and kinetics of curing process of thermosetting systems. The results showed that the best curing characteristic and glass transition temperature are obtained at a ratio of epoxy resin: DICY: accelerator equal to 94:5:1. The thermal stability of the phosphorus-containing epoxy resins was investigated by thermogravimetric analysis in nitrogen and air, DSC, SEM and LOI test measurements.

Keywords: epoxy resins, flame retardant properties, phosphorus-containing compounds, thermal stability

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Authors: M. Yilmaz, I. Yilmaz, M. Uysal

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The Earth system generates different phenomena that are observable at the surface of the Earth such as mass deformations and displacements leading to plate tectonics, earthquakes, and volcanism. The dynamic processes associated with the interior, surface, and atmosphere of the Earth affect the three pillars of geodesy: shape of the Earth, its gravity field, and its rotation. Geodesy establishes a characteristic structure in order to define, monitor, and predict of the whole Earth system. The traditional and new instruments, observables, and techniques in geodesy are related to the gravity field. Therefore, the geodesy monitors the gravity field and its temporal variability in order to transform the geodetic observations made on the physical surface of the Earth into the geometrical surface in which positions are mathematically defined. In this paper, the main components of the gravity field modeling, (Free-air and Bouguer) gravity anomalies are calculated via recent global models (EGM2008, EIGEN6C4, and GECO) over a selected study area. The model-based gravity anomalies are compared with the corresponding terrestrial gravity data in terms of standard deviation (SD) and root mean square error (RMSE) for determining the best fit global model in the study area at a regional scale in Turkey. The least SD (13.63 mGal) and RMSE (15.71 mGal) were obtained by EGM2008 for the Free-air gravity anomaly residuals. For the Bouguer gravity anomaly residuals, EIGEN6C4 provides the least SD (8.05 mGal) and RMSE (8.12 mGal). The results indicated that EIGEN6C4 can be a useful tool for modeling the gravity field of the Earth over the study area.

Keywords: free-air gravity anomaly, Bouguer gravity anomaly, global model, land gravity

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Authors: Feny Acelia Silaban

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The development of Indonesia’s infrastructure in many islands is significantly increased through the years. Based on this condition, concrete materials which are extracted from natural resources are over exploited and slowly becoming rare, thus the demand for alternative materials becomes so urgently crucial. Oil Palm is one of the biggest commodities in Indonesia with the total amount of 31 million tons in the last 2014. The production of palm oil also generates lots of solid wastes in the form of Oil Palm Shell (OPS). Constructing more environmentally sustainable structures can be achieved by producing lightweight concrete using the Oil Palm Shell (OPS). This paper investigated the effects of OPS and combination of Superplasticizer and fly ash proportion of lightweight concrete mix design to the compressive strength, flexure strength, modulus of elasticity, shrinkage behavior, and water absorption. The Oil Palm Shell had undergone special treatment by washing it with hot water and soap to reduce the oil content. This experiment used four different proportions of Superplasticizer with fly ash and 30 % OPS proportion from the weight of total compositions mixture by the result of trial mix. The experiment result showed that using OPS coarse aggregates and Superplasticizer with fly ash, the average of 28-day compressive strength reached 30-35 MPa. The highest 28-day compressive strength comes from 1.2 % Superplasticizer with 5 % fly ash proportion samples with the strength by 33 MPa. The sample with proportion of 1 % Superplasticizer and 7.5 % fly ash has the highest shrinkage value compared to other proportions. The characteristic of OPS as coarse aggregates is in a standard range of natural coarse aggregates. In general, this lightweight concrete using OPS coarse aggregate and Superplasticizer has high potential to be green-structural lightweight concrete alternative in Indonesia.

Keywords: lightweight concrete, oil palm shell, waste materials, superplasticizer

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Authors: Güzi̇n Ti̇rkeş, Özge Teki̇n, Kerem Kurtuluş, Y. Yekta Yurtseven, Murat Baran

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A scanning electron microscope (SEM) is a type of electron microscope mainly used in nanoscience and nanotechnology areas. Automatic image recognition and classification are among the general areas of application concerning SEM. In line with these usages, the present paper proposes a deep learning algorithm that classifies SEM images into nine categories by means of an online application to simplify the process. The NFFA-EUROPE - 100% SEM data set, containing approximately 21,000 images, was used to train and test the algorithm at 80% and 20%, respectively. Validation was carried out using a separate data set obtained from the Middle East Technical University (METU) in Turkey. To increase the accuracy in the results, the Inception ResNet-V2 model was used in view of the Fine-Tuning approach. By using a confusion matrix, it was observed that the coated-surface category has a negative effect on the accuracy of the results since it contains other categories in the data set, thereby confusing the model when detecting category-specific patterns. For this reason, the coated-surface category was removed from the train data set, hence increasing accuracy by up to 96.5%.

Keywords: convolutional neural networks, deep learning, image classification, scanning electron microscope

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Authors: Florence Ibeh, David Oyewmi Oyekunle, David Boohene

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The continuous advancement of information technology has completely transformed how businesses and organizations operate on a global scale. The widespread availability of virtual communication tools enables individuals to opt for remote work. While remote employment offers various benefits, such as facilitating corporate growth and enhancing customer support, it also presents distinct challenges. Therefore, investigating the intricacies of virtual team morale is crucial for ensuring the achievement of project objectives. For this study, content analysis of pre-existing secondary data was employed to examine the phenomenon. Essential elements vital for improving the success of projects within virtual teams were identified. These factors include technology adoption, creating a distraction-free work environment, effective leadership, trust-building, clear communication channels, well-defined task allocation, active team participation, and motivation. Furthermore, the study established a substantial correlation between morale levels and the participation and productivity of virtual team members. Higher levels of morale were associated with optimal performance among virtual teams. The study determined that the key factors for enhancing project performance in virtual teams are the adoption of technology, a focused environment, effective leadership, trust, communication, well-defined tasks, collaborative teamwork, and motivation. Additionally, the study discovered that modifying the optimal strategies employed by in-office teams can enhance the diminished morale prevalent in remote teams to sustain a high level of team morale for virtual teams. The findings of this study are highly significant in the dynamic field of project management. Currently, there is limited information regarding strategies that address challenges arising from external factors in virtual teams, such as ambient noise and disruptions caused by family members. The findings underscore the significance of selecting appropriate communication technologies, delineating distinct roles and responsibilities for virtual team members, and nurturing a culture of accountability and trust. Promoting seamless collaboration and instilling motivation among virtual team members are deemed highly effective in augmenting employee engagement and performance within virtual team setting.

Keywords: virtual teams, morale, project performance, distract-free environment, technology adaptation

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Authors: Ravi Kumar

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Agricultural wastes are the non-product outcomes of agricultural processing whose monetary value is less as compared to its collection cost, transportation, and processing. When such agricultural waste is not properly disposed of, it may damage the natural environment and cause detrimental pollution in the atmosphere. Agricultural development and intensive farming methods usually result in wastes that remarkably affect the rural environments in particular and the global environment in general. Agricultural waste has toxicity latent to human beings, animals, and plants through various indirect and direct outlets. The present paper explores the various activities that result in agricultural waste and the routes that can utilize the agricultural waste in a manageable manner to reduce its adverse impact on the environment. Presently, the agricultural waste management system for ecological agriculture and sustainable development has emerged as a crucial issue for policymakers. There is an urgent need to consider agricultural wastes as prospective resources rather than undesirable in order to avoid the transmission and contamination of water, land, and air resources. Waste management includes the disposal and treatment of waste with a view to eliminate threats of waste by modifying the waste to condense the microbial load. The study concludes that proper waste utilization and management will facilitate the purification and development of the ecosystem and provide feasible biofuel resources. This proper utilization and management of these wastes for agricultural production may reduce their accumulation and further reduce environmental pollution by improving environmental health.

Keywords: agricultural waste, utilization, management, environment, health

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Authors: Kopila Shrestha

Abstract:

Adolescent sexual reproductive health is one of the most important issues in the world. Reproductive ability is taking place at an earlier age and adolescents are indulging in risk taking behaviors day by day. A descriptive cross-sectional study was conducted in Kathmandu valley to assess the knowledge regarding sexual and reproductive health among adolescent. Total of 200 respondents were selected through non-probability convenient sampling technique. Self-administered written questionnaires using semi-structured questions were used. The collected data were analyzed by using descriptive statistics such as frequency, percentage, mean, standard deviation and inferential statistics such as Chi-square test. The findings revealed that most of the respondents had adequate knowledge regarding transmission and protection of HIV/AIDs and STIs but still some respondents had a misconception regarding it. Few respondents had knowledge regarding legal age for marriage and the minimum age for first child bearing. The statistical analysis revealed that the total mean knowledge score with standard deviation was 45.02±8.674. Nearly half of the respondents (49.5%) had a moderate level of knowledge, followed by an inadequate level of knowledge 29.5% and adequate level of knowledge 21.0% regarding sexual and reproductive health. There was significant association of level of knowledge with area of residence (p-value .002) but no association with age (p-value .067), sex (p-value .999), religion (p-value .082) and ethnicity (p-value .114). Nearly half of the participants possess some knowledge about sexual and reproductive health but still effective educational intervention is required in higher secondary school to encourage more sensible and healthy behaviour.

Keywords: adolescents, higher secondary school, knowledge, sexual and reproductive health

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Authors: P. Vanichkobchinda

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The Logistics Transportation techniques, Open Vehicle Routing (OVR) is an approach toward transportation cost reduction, especially for long distance pickup and delivery nodes. The outstanding characteristic of OVR is that the route starting node and ending node are not necessary the same as in typical vehicle routing problems. This advantage enables the routing to flow continuously and the vehicle does not always return to its home base. This research aims to develop a heuristic for the open vehicle routing problem with pickup and delivery under time window and loading capacity constraints to minimize the total distance. The proposed heuristic is developed based on the Insertion method, which is a simple method and suitable for the rapid calculation that allows insertion of the new additional transportation requirements along the original paths. According to the heuristic analysis, cost comparisons between the proposed heuristic and companies are using method, nearest neighbor method show that the insertion heuristic. Moreover, the proposed heuristic gave superior solutions in all types of test problems. In conclusion, the proposed heuristic can effectively and efficiently solve the open vehicle routing. The research indicates that the improvement of new transport's calculation and the open vehicle routing with "Insertion Heuristic" represent a better outcome with 34.3 percent in average. in cost savings. Moreover, the proposed heuristic gave superior solutions in all types of test problems. In conclusion, the proposed heuristic can effectively and efficiently solve the open vehicle routing.

Keywords: business competitiveness, cost reduction, SMEs, logistics transportation, VRP

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Authors: Tarek Dandashi

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WSNs may provide a fast and reliable solution for the early detection of environment events like forest fires. This is crucial for alerting and calling for fire brigade intervention. Sensor nodes communicate sensor data to a host station, which enables a global analysis and the generation of a reliable decision on a potential fire and its location. A WSN with TinyOS and nesC for the capturing and transmission of a variety of sensor information with controlled source, data rates, duration, and the records/displaying activity traces is presented. We propose a similarity distance (SD) between the distribution of currently sensed data and that of a reference. At any given time, a fire causes diverging opinions in the reported data, which alters the usual data distribution. Basically, SD consists of a metric on the Cumulative Distribution Function (CDF). SD is designed to be invariant versus day-to-day changes of temperature, changes due to the surrounding environment, and normal changes in weather, which preserve the data locality. Evaluation shows that SD sensitivity is quadratic versus an increase in sensor node temperature for a group of sensors of different sizes and neighborhood. Simulation of fire spreading when ignition is placed at random locations with some wind speed shows that SD takes a few minutes to reliably detect fires and locate them. We also discuss the case of false negative and false positive and their impact on the decision reliability.

Keywords: forest fire, WSN, wireless sensor network, algortihm

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Authors: Hubert Beisch, Janik Marx, Svenja Garlof, Roman Shvets, Ivan Grygorchak, Andriy Kityk, Bodo Fiedler

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Three-dimensional carbon materials can be used as electrode materials for energy storage systems such as batteries and supercapacitors. Fast charging and discharging times are realizable without reducing the performance due to aging processes. Furthermore high specific surface area (SSA) of three-dimensional carbon structures leads to high specific capacities. One newly developed carbon foam is Globugraphite. This interconnected globular carbon morphology with statistically distributed hierarchical pores is manufactured by a chemical vapor deposition (CVD) process from ceramic templates resulting from a sintering process. Via scanning electron (SEM) and transmission electron microscopy (TEM), the morphology is characterized. Moreover, the SSA was measured by the Brunauer–Emmett–Teller (BET) theory. Measurements of Globugraphite in an organic and inorganic electrolyte show high energy densities and power densities resulting from ion absorption by forming an electrochemical double layer. A comparison of the specific values is summarized in a Ragone diagram. Energy densities up to 48 Wh/kg and power densities to 833 W/kg could be achieved for an SSA from 376 m²/g to 859 m²/g. For organic electrolyte, a specific capacity of 100 F/g at a density of 20 mg/cm³ was achieved.

Keywords: BET, carbon foam, CVD process, electrochemical cell, Ragone diagram, SEM, TEM

Procedia PDF Downloads 234

Authors: Yen-Luan Chen

Abstract:

Maintenance has a great impact on the capacity of production and on the quality of the products, and therefore, it deserves continuous improvement. Maintenance procedure done before a failure is called preventive maintenance (PM). Sequential PM, which specifies that a system should be maintained at a sequence of intervals with unequal lengths, is one of the commonly used PM policies. This article proposes a generalized sequential PM policy for a system subject to shocks with imperfect maintenance and random working time. The shocks arrive according to a non-homogeneous Poisson process (NHPP) with varied intensity function in each maintenance interval. As a shock occurs, the system suffers two types of failures with number-dependent probabilities: type-I (minor) failure, which is rectified by a minimal repair, and type-II (catastrophic) failure, which is removed by a corrective maintenance (CM). The imperfect maintenance is carried out to improve the system failure characteristic due to the altered shock process. The sequential preventive maintenance-last (PML) policy is defined as that the system is maintained before any CM occurs at a planned time Ti or at the completion of a working time in the i-th maintenance interval, whichever occurs last. At the N-th maintenance, the system is replaced rather than maintained. This article first takes up the sequential PML policy with random working time and imperfect maintenance in reliability engineering. The optimal preventive maintenance schedule that minimizes the mean cost rate of a replacement cycle is derived analytically and determined in terms of its existence and uniqueness. The proposed models provide a general framework for analyzing the maintenance policies in reliability theory.

Keywords: optimization, preventive maintenance, random working time, minimal repair, replacement, reliability

Procedia PDF Downloads 275

Authors: Joao Garretto, R. J. Yarwood, Vamsi Borra, Frank Li

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Bluetooth Low Energy (BLE) has emerged as one of the main wireless communication technologies used in low-power electronics, such as wearables, beacons, and Internet of Things (IoT) devices. BLE’s energy efficiency characteristic, smart mobiles interoperability, and Over the Air (OTA) capabilities are essential features for ultralow-power devices, which are usually designed with size and cost constraints. Most current research regarding the power analysis of BLE devices focuses on the theoretical aspects of the advertising and scanning cycles, with most results being presented in the form of mathematical models and computer software simulations. Such computer modeling and simulations are important for the comprehension of the technology, but hardware measurement is essential for the understanding of how BLE devices behave in real operation. In addition, recent literature focuses mostly on the BLE technology, leaving possible applications and its analysis out of scope. In this paper, a coin cell battery-powered BLE Data Acquisition Device, with a 4-in-1 sensor and one accelerometer, is proposed and evaluated with respect to its Power Consumption. First, evaluations of the device in advertising mode with the sensors turned off completely, followed by the power analysis when each of the sensors is individually turned on and data is being transmitted, and concluding with the power consumption evaluation when both sensors are on and respectively broadcasting the data to a mobile phone. The results presented in this paper are real-time measurements of the electrical current consumption of the BLE device, where the energy levels that are demonstrated are matched to the BLE behavior and sensor activity.

Keywords: bluetooth low energy, power analysis, BLE advertising cycle, wireless sensor node

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Authors: Barenten Suciu

Abstract:

Classical matrix calculus and Routh-Hurwitz stability conditions, applied to the snake-like motion of the conical wheel axle, lead to the conclusion that the hunting mode is inherently unstable, and its natural frequency is a complex number. In order to analytically solve such a complicated vibration model, either the inertia terms were neglected, in the model designated as geometrical, or restrictions on the creep coefficients and yawing diameter were imposed, in the so-called dynamical model. Here, an alternative solution is proposed to solve the hunting mode, based on the observation that the bullet train wheel axle is equipped with cylindrical wheels. One argues that for such wheel treads, the geometrical hunting is irrelevant, since its natural frequency becomes nil, but the dynamical hunting is significant since its natural frequency reduces to a real number. Moreover, one illustrates that the geometrical simplification of the wheel causes the stabilization of the hunting mode, since the characteristic quartic equation, derived for conical wheels, reduces to a quadratic equation of positive coefficients, for cylindrical wheels. Quite simple analytical expressions for the damping ratio and natural frequency are obtained, without applying restrictions into the model of contact. Graphs of the time-depending hunting lateral perturbation, including the maximal and inflexion points, are presented both for the critically-damped and the over-damped wheel axles.

Keywords: bullet train, creep, cylindrical wheels, damping, dynamical hunting, stability, vibration analysis

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Authors: Douglas Rossi Ramos

Abstract:

The current digital conjuncture, called by some authors as 'Internet of Things' (IoT), 'Web 2.0' or even 'Web 3.0', consists of a network that encompasses any communication of objects and entities, such as data, information, technologies, and people. At this juncture, especially characterized by an "object socialization," communication can no longer be represented as a simple informational flow of messages from a sender, crossing a channel or medium, reaching a receiver. The idea of communication must, therefore, be thought of more broadly in which it is possible to analyze the process communicative from interactions between humans and nonhumans. To think about this complexity, a communicative process that encompasses both humans and other beings or entities communicating (objects and things), it is necessary to constitute a new epistemology of communication to rethink concepts and notions commonly attributed to humans such as 'memory.' This research aims to contribute to this epistemological constitution from the discussion about the notion of memory according to the complex ontology of Henri Bergson. Among the results (the notion of memory in Bergson presents itself as a conceptual tool for the analysis of posthumanism and the anthropomorphic conjuncture of the new advent of digital), there was the need to think about an ontological memory, analyzed as a being itself (being itself of memory), as a strategy for understanding the forms of interaction and communication that constitute the new digital conjuncture, in which communicating beings or entities tend to interact with each other. Rethinking the idea of communication beyond the dimension of transmission in informative sequences paves the way for an ecological perspective of the digital dwelling condition.

Keywords: communication, digital, Henri Bergson, memory

Procedia PDF Downloads 164