Search results for: academic performance index
1329 On-Farm Evaluation of Fast and Slow Growing Genotypes for Organic and Pasture Poultry Production Systems
Authors: Komala Arsi, Terrel Spencer, Casey M. Owens, Dan J. Donoghue, Ann M. Donoghue
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Organic poultry production is becoming increasingly popular in the United States with approximately 17% increase in the sales of organic meat and poultry in 2016. As per the National Organic Program (NOP), organic poultry production system should operate according to specific standards, including access to outdoors. In the United States, organic poultry farmers are raising both fast growing and slow growing genotypes for alternative productive systems. Even though heritage breed birds grow much slower compared to commercial breeds, many free range producers believe that they are better suited for outdoor production systems. We conducted an on-farm trial on a working pasture poultry farm to compare the performance and meat quality characteristics of a slow-growing heritage breed (Freedom Rangers, FR), and two commonly used fast growing types of chickens (Cornish cross, CC and Naked Neck, NN), raised on pasture, in side by side pens segregated by breed (n=70/breed). CC and NN group birds were reared for eight weeks whereas FR group birds were reared for 10 weeks and all the birds were commercially processed. By the end of the rearing period, the final body weight of FR group birds was significantly lower than both the fast growing genotypes (CC and NN). Both CC and NN birds showed significantly higher live weight, carcass weight as well as fillet, tender and leg yield (P < 0.05). There was no difference in the wing and rack yield among the different groups. Color of the meat was measured using CEILAB method and expressed as lightness (L), redness (a*) and yellowness (b*). The breast meat from FR birds was much redder (higher a* values) and less yellow (lesser b* values) compared to both the fast growing type of chickens (P < 0.05). Overall, fast growing genotypes produced higher carcass weight and meat yield compared to slow growing genotypes and appear to be an economical option for alternative production systems.Keywords: fast growing chickens, meat quality, pasture, slow growing chickens
Procedia PDF Downloads 3801328 Investigation of the Technological Demonstrator 14x B in Different Angle of Attack in Hypersonic Velocity
Authors: Victor Alves Barros Galvão, Israel Da Silveira Rego, Antonio Carlos Oliveira, Paulo Gilberto De Paula Toro
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The Brazilian hypersonic aerospace vehicle 14-X B, VHA 14-X B, is a vehicle integrated with the hypersonic airbreathing propulsion system based on supersonic combustion (scramjet), developing in Aerothermodynamics and hypersonic Prof. Henry T. Nagamatsu Laboratory, to conduct demonstration in atmospheric flight at the speed corresponding to Mach number 7 at an altitude of 30km. In the experimental procedure the hypersonic shock tunnel T3 was used, installed in that laboratory. This device simulates the flow over a model is fixed in the test section and can also simulate different atmospheric conditions. The scramjet technology offers substantial advantages to improve aerospace vehicle performance which flies at a hypersonic speed through the Earth's atmosphere by reducing fuel consumption on board. Basically, the scramjet is an aspirated aircraft engine fully integrated that uses oblique/conic shock waves generated during hypersonic flight, to promote the deceleration and compression of atmospheric air in scramjet inlet. During the hypersonic flight, the vehicle VHA 14-X will suffer atmospheric influences, promoting changes in the vehicle's angles of attack (angle that the mean line of vehicle makes with respect to the direction of the flow). Based on this information, a study is conducted to analyze the influences of changes in the vehicle's angle of attack during the atmospheric flight. Analytical theoretical analysis, simulation computational fluid dynamics and experimental investigation are the methodologies used to design a technological demonstrator prior to the flight in the atmosphere. This paper considers analysis of the thermodynamic properties (pressure, temperature, density, sound velocity) in lower surface of the VHA 14-X B. Also, it considers air as an ideal gas and chemical equilibrium, with and without boundary layer, considering changes in the vehicle's angle of attack (positive and negative in relation to the flow) and bi-dimensional expansion wave theory at the expansion section (Theory of Prandtl-Meyer).Keywords: angle of attack, experimental hypersonic, hypersonic airbreathing propulsion, Scramjet
Procedia PDF Downloads 4001327 Derivation of Fragility Functions of Marine Drilling Risers Under Ocean Environment
Authors: Pranjal Srivastava, Piyali Sengupta
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The performance of marine drilling risers is crucial in the offshore oil and gas industry to ensure safe drilling operation with minimum downtime. Experimental investigations on marine drilling risers are limited in the literature owing to the expensive and exhaustive test setup required to replicate the realistic riser model and ocean environment in the laboratory. Therefore, this study presents an analytical model of marine drilling riser for determining its fragility under ocean environmental loading. In this study, the marine drilling riser is idealized as a continuous beam having a concentric circular cross-section. Hydrodynamic loading acting on the marine drilling riser is determined by Morison’s equations. By considering the equilibrium of forces on the marine drilling riser for the connected and normal drilling conditions, the governing partial differential equations in terms of independent variables z (depth) and t (time) are derived. Subsequently, the Runge Kutta method and Finite Difference Method are employed for solving the partial differential equations arising from the analytical model. The proposed analytical approach is successfully validated with respect to the experimental results from the literature. From the dynamic analysis results of the proposed analytical approach, the critical design parameters peak displacements, upper and lower flex joint rotations and von Mises stresses of marine drilling risers are determined. An extensive parametric study is conducted to explore the effects of top tension, drilling depth, ocean current speed and platform drift on the critical design parameters of the marine drilling riser. Thereafter, incremental dynamic analysis is performed to derive the fragility functions of shallow water and deep-water marine drilling risers under ocean environmental loading. The proposed methodology can also be adopted for downtime estimation of marine drilling risers incorporating the ranges of uncertainties associated with the ocean environment, especially at deep and ultra-deepwater.Keywords: drilling riser, marine, analytical model, fragility
Procedia PDF Downloads 1391326 Effect of N2-cold Plasma Treatment of Carbon Supports on the Activity of Pt3Pd3Sn2/C Towards the Dimethyl Ether Oxidation
Authors: Medhanie Gebremedhin Gebru, Alex Schechter
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Dimethyl ether (DME) possesses several advantages over other small organic molecules such as methanol, ethanol, and ammonia in terms of providing higher energy density, being less toxic, and having lower Nafion membrane crossover. However, the absence of an active and stable catalyst has been the bottleneck that hindered the commercialization of direct DME fuel cells. A Vulcan XC72 carbon-supported ternary metal catalyst, Pt₃Pd₃Sn₂/C is reported to have yielded the highest specific power density (90 mW mg-¹PGM) as compared to other catalysts tested fordirect DME fuel cell (DDMEFC). However, the micropores and sulfur groups present in Vulcan XC72 hinder the fuel utilization by causing Pt agglomeration and sulfur poisoning. Vulcan XC72 having a high carbon sp³ hybridization content, is also prone to corrosion. Therefore, carbon supports such as multi-walled carbon nanotube (MWCNT), black pearl 2000 (BP2000), and their cold N2 plasma-treated counterpartswere tested to further enhance the activity of the catalyst, and the outputs with these carbons were compared with the originally used support. Detailed characterization of the pristine and carbon supports was conducted. Electrochemical measurements in three-electrode cells and laboratory prototype fuel cells were conducted.Pt₃Pd₃Sn₂/BP2000 exhibited excellent performance in terms of electrochemical active surface area (ECSA), peak current density (jp), and DME oxidation charge (Qoxi). The effect of the plasma activation on the activity improvement was observed only in the case of MWCNT while having little or no effect on the other carbons. A Pt₃Pd₃Sn₂ supported on the optimized mixture of carbons containing 75% plasma-activated MWCNT and 25% BP2000 (Pt₃Pd₃Sn₂/75M25B) provided the highest reported power density of 117 mW mg-1PGM using an anode loading of1.55 mgPGMcm⁻².Keywords: DME, DDMEFC, ternary metal catalyst, carbon support, plasma activation
Procedia PDF Downloads 1361325 Impact of Environmental Rule of Law towards Positive Environmental Outcomes in Nigeria
Authors: Kate N. Okeke
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The ever-growing needs of man requiring satisfaction have pushed him strongly towards industrialization which has and is still leaving environmental degradation and its attendant negative impacts in its wake. It is, therefore, not surprising that the enjoyment of fundamental rights like food supply, security of lives and property, freedom of worship, health and education have been drastically affected by such degradation. In recognition of the imperative need to protect the environment and human rights, many global instruments and constitutions have recognized the right to a healthy and sustainable environment. Some environmental advocates and quite a number of literatures on the subject matter call for the recognition of environmental rights via rule of law as a vital means of achieving positive outcomes on the subject matter. However, although there are numerous countries with constitutional environmental provisions, most of them such as Nigeria, have shown poor environmental performance. A notable problem is the fact that the constitution which recognizes environmental rights appears in its other provisions to contradict its provisions by making enforceability of the environmental rights unattainable. While adopting a descriptive, analytical, comparative and explanatory study design in reviewing a successful positive environmental outcome via the rule of law, this article argues that rule of law on a balance of scale, weighs more than just environmental rights recognition and therefore should receive more attention by environmental lawyers and advocates. This is because with rule of law, members of a society are sure of getting the most out of the environmental rights existing in their legal system. Members of Niger-Delta communities of Nigeria will benefit from the environmental rights existing in Nigeria. They are exposed to environmental degradation and pollution with effects such as acidic rainfall, pollution of farmlands and clean water sources. These and many more are consequences of oil and gas exploration. It will also pave way for solving the violence between cattle herdsmen and farmers in the Middle Belt and other regions of Nigeria. Their clashes are over natural resource control. Having seen that environmental rule of law is vital to sustainable development, this paper aims to contribute to discussions on how best the vehicle of rule law can be driven towards achieving positive environmental outcomes. This will be in reliance on other enforceable provisions in the Nigerian Constitution. Other domesticated international instruments will also be considered to attain sustainable environment and development.Keywords: environment, rule of law, constitution, sustainability
Procedia PDF Downloads 1491324 Application of Multilayer Perceptron and Markov Chain Analysis Based Hybrid-Approach for Predicting and Monitoring the Pattern of LULC Using Random Forest Classification in Jhelum District, Punjab, Pakistan
Authors: Basit Aftab, Zhichao Wang, Feng Zhongke
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Land Use and Land Cover Change (LULCC) is a critical environmental issue that has significant effects on biodiversity, ecosystem services, and climate change. This study examines the spatiotemporal dynamics of land use and land cover (LULC) across a three-decade period (1992–2022) in a district area. The goal is to support sustainable land management and urban planning by utilizing the combination of remote sensing, GIS data, and observations from Landsat satellites 5 and 8 to provide precise predictions of the trajectory of urban sprawl. In order to forecast the LULCC patterns, this study suggests a hybrid strategy that combines the Random Forest method with Multilayer Perceptron (MLP) and Markov Chain analysis. To predict the dynamics of LULC change for the year 2035, a hybrid technique based on multilayer Perceptron and Markov Chain Model Analysis (MLP-MCA) was employed. The area of developed land has increased significantly, while the amount of bare land, vegetation, and forest cover have all decreased. This is because the principal land types have changed due to population growth and economic expansion. The study also discovered that between 1998 and 2023, the built-up area increased by 468 km² as a result of the replacement of natural resources. It is estimated that 25.04% of the study area's urbanization will be increased by 2035. The performance of the model was confirmed with an overall accuracy of 90% and a kappa coefficient of around 0.89. It is important to use advanced predictive models to guide sustainable urban development strategies. It provides valuable insights for policymakers, land managers, and researchers to support sustainable land use planning, conservation efforts, and climate change mitigation strategies.Keywords: land use land cover, Markov chain model, multi-layer perceptron, random forest, sustainable land, remote sensing.
Procedia PDF Downloads 181323 Importance of Detecting Malingering Patients in Clinical Setting
Authors: Sakshi Chopra, Harsimarpreet Kaur, Ashima Nehra
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Objectives: Malingering is fabricating or exaggerating the symptoms of mental or physical disorders for a variety of secondary gains or motives, which may include financial compensation; avoiding work; getting lighter criminal sentences; or simply to attract attention or sympathy. Malingering is different from somatization disorder and factitious disorder. The prevalence of malingering is unknown and difficult to determine. In an estimated study in forensic population, it can reach up to 17% cases. But the accuracy of such estimates is questionable as successful malingerers are not detected and thus, not included. Methods: The case study of a 58 years old, right handed, graduate, pre-morbidly working in a national company with reported history of stroke leading to head injury; cerebral infarction/facial palsy and dementia. He was referred for disability certification so that his job position can be transferred to his son as he could not work anymore. A series of Neuropsychological tests were administered. Results: With a mental age of < 2.5 years; social adaptive functioning was overall < 20 showing profound Mental Retardation, less than 1 year social age in abilities of self-help, eating, dressing, locomotion, occupation, communication, self-direction, and socialization; severely impaired verbal and performance ability, 96% impairment in Activities of Daily Living, with an indication of very severe depression. With inconsistent and fluctuating medical findings and problem descriptions to different health professionals forming the board for his disability, it was concluded that this patient was malingering. Conclusions: Even though it can be easily defined, malingering can be very challenging to diagnosis. Cases of malingering impose a substantial economic burden on the health care system and false attribution of malingering imposes a substantial burden of suffering on a significant proportion of the patient population. Timely, tactful diagnosis and management can help ease this patient burden on the healthcare system. Malingering can be detected by only trained mental health professionals in the clinical setting.Keywords: disability, India, malingering, neuropsychological assessment
Procedia PDF Downloads 4121322 Effects of Magnetization Patterns on Characteristics of Permanent Magnet Linear Synchronous Generator for Wave Energy Converter Applications
Authors: Sung-Won Seo, Jang-Young Choi
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The rare earth magnets used in synchronous generators offer many advantages, including high efficiency, greatly reduced the size, and weight. The permanent magnet linear synchronous generator (PMLSG) allows for direct drive without the need for a mechanical device. Therefore, the PMLSG is well suited to translational applications, such as wave energy converters and free piston energy converters. This manuscript compares the effects of different magnetization patterns on the characteristics of double-sided PMLSGs in slotless stator structures. The Halbach array has a higher flux density in air-gap than the Vertical array, and the advantages of its performance and efficiency are widely known. To verify the advantage of Halbach array, we apply a finite element method (FEM) and analytical method. In general, a FEM and an analytical method are used in the electromagnetic analysis for determining model characteristics, and the FEM is preferable to magnetic field analysis. However, the FEM is often slow and inflexible. On the other hand, the analytical method requires little time and produces accurate analysis of the magnetic field. Therefore, the flux density in air-gap and the Back-EMF can be obtained by FEM. In addition, the results from the analytical method correspond well with the FEM results. The model of the Halbach array reveals less copper loss than the model of the Vertical array, because of the Halbach array’s high output power density. The model of the Vertical array is lower core loss than the model of Halbach array, because of the lower flux density in air-gap. Therefore, the current density in the Vertical model is higher for identical power output. The completed manuscript will include the magnetic field characteristics and structural features of both models, comparing various results, and specific comparative analysis will be presented for the determination of the best model for application in a wave energy converting system.Keywords: wave energy converter, permanent magnet linear synchronous generator, finite element method, analytical method
Procedia PDF Downloads 2951321 Phase Optimized Ternary Alloy Material for Gas Turbines
Authors: Mayandi Ramanathan
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Gas turbine blades see the most aggressive thermal stress conditions within the engine, due to Turbine Entry Temperatures in the range of 1500 to 1600°C, but in synchronization with other functional components, they must readily deliver efficient performance, whilst incurring minimal overhaul and repair costs during its service life up to 5 million flying miles. The blades rotate at very high rotation rates and remove significant amount of thermal power from the gas stream. At high temperatures the major component failure mechanism is creep. During its service over time under high temperatures and loads, the blade will deform, lengthen and rupture. High strength and stiffness in the longitudinal direction up to elevated service temperatures are certainly the most needed properties of turbine blades. The proposed advanced Ti alloy material needs a process that provides strategic orientation of metallic ordering, uniformity in composition and high metallic strength. 25% Ta/(Al+Ta) ratio ensures TaAl3 phase formation, where as 51% Al/(Al+Ti) ratio ensures formation of α-Ti3Al and γ-TiAl mixed phases fand the three phase combination ensures minimal Al excess (~1.4% Al excess), unlike Ti-47Al-2Cr-2Nb which has significant excess Al (~5% Al excess) that could affect the service life of turbine blades. This presentation will involve the summary of additive manufacturing and heat treatment process conditions to fabricate turbine blade with Ti-43Al matrix alloyed with optimized amount of refractory Ta metal. Summary of thermo-mechanical test results such as high temperature tensile strength, creep strain rate, thermal expansion coefficient and fracture toughness will be presented. Improvement in service temperature of the turbine blades and corrosion resistance dependence on coercivity of the alloy material will be reported. Phase compositions will be quantified, and a summary of its correlation with creep strain rate will be presented.Keywords: gas turbine, aerospace, specific strength, creep, high temperature materials, alloys, phase optimization
Procedia PDF Downloads 1771320 Remediation of Dye Contaminated Wastewater Using N, Pd Co-Doped TiO₂ Photocatalyst Derived from Polyamidoamine Dendrimer G1 as Template
Authors: Sarre Nzaba, Bulelwa Ntsendwana, Bekkie Mamba, Alex Kuvarega
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The discharge of azo dyes such as Brilliant black (BB) into the water bodies has carcinogenic and mutagenic effects on humankind and the ecosystem. Conventional water treatment techniques fail to degrade these dyes completely thereby posing more problems. Advanced oxidation processes (AOPs) are promising technologies in solving the problem. Anatase type nitrogen-platinum (N, Pt) co-doped TiO₂ photocatalysts were prepared by a modified sol-gel method using amine terminated polyamidoamine generation 1 (PG1) as a template and source of nitrogen. The resultant photocatalysts were characterized by X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X‐ray photoelectron spectroscopy (XPS), UV‐Vis diffuse reflectance spectroscopy, photoluminescence spectroscopy (PL), Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy (RS), thermal gravimetric analysis (TGA). The results showed that the calcination atmosphere played an important role in the morphology, crystal structure, spectral absorption, oxygen vacancy concentration, and visible light photocatalytic performance of the catalysts. Anatase phase particles ranging between 9- 20 nm were also confirmed by TEM, SEM, and analysis. The origin of the visible light photocatalytic activity was attributed to both the elemental N and Pd dopants and the existence of oxygen vacancies. Co-doping imparted a shift in the visible region of the solar spectrum. The visible light photocatalytic activity of the samples was investigated by monitoring the photocatalytic degradation of brilliant black dye. Co-doped TiO₂ showed greater photocatalytic brilliant black degradation efficiency compared to singly doped N-TiO₂ or Pd-TiO₂ under visible light irradiation. The highest reaction rate constant of 3.132 x 10-2 min⁻¹ was observed for N, Pd co-doped TiO₂ (2% Pd). The results demonstrated that the N, Pd co-doped TiO₂ (2% Pd) sample could completely degrade the dye in 3 h, while the commercial TiO₂ showed the lowest dye degradation efficiency (52.66%).Keywords: brilliant black, Co-doped TiO₂, polyamidoamine generation 1 (PAMAM G1), photodegradation
Procedia PDF Downloads 1751319 Effect of Molecular Weight Distribution on Toughening Performance of Polybutadiene in Polystyrene
Authors: Mohamad Mohsen Yavarizadeh
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Polystyrene (PS) and related homopolymers are brittle materials that typically fail in tensile tests at very low strains. These polymers can be toughened by the addition of rubbery particles which initiate a large number of crazes that produce substantial plastic strain at relatively low stresses. Considerable energy is dissipated in the formation of these crazes, producing a relatively tough material that shows an impact toughness of more than 5 times of pure PS. While cross linking of rubbery phase is necessary in aforementioned mechanism of toughening, another mechanism of toughening was also introduced in which low molecular weight liquid rubbers can also toughen PS when dispersed in the form of small pools in the glassy matrix without any cross linking. However, this new mechanism which is based on local plasticization, fails to act properly at high strain rate deformations, i.e. impact tests. In this work, the idea of combination of these two mechanisms was tried. To do so, Polybutadiene rubbers (PB) with bimodal distribution of molecular weight were prepared in which, comparable fractions of very high and very low molecular weight rubbers were mixed. Incorporation of these materials in PS matrix in a reactive process resulted in more significant increases in toughness of PS. In other words, although low molecular weight PB is ineffective in high strain rate impact test by itself, it showed a significant synergistic effect when combined with high molecular weight PB. Surprisingly, incorporation of just 10% of low molecular weight PB doubled the impact toughness of regular high impact PS (HIPS). It was observed that most of rubbery particles could initiate crazes. The effectiveness of low molecular weight PB in impact test was attributed to low strain rate deformation of each individual craze as a result of producing a large number of crazes in this material. In other words, high molecular weight PB chains make it possible to have an appropriate dispersion of rubbery phase in order to create a large number of crazes in the PS matrix and consequently decrease the velocity of each craze. Low molecular weight PB, in turn, would have enough time to locally plasticize craze fibrils and enhance the energy dissipation.Keywords: molecular weight distribution, polystyrene, toughness, homopolymer
Procedia PDF Downloads 4381318 Processing and Characterization of Oxide Dispersion Strengthened (ODS) Fe-14Cr-3W-0.5Ti-0.3Y₂O₃ (14YWT) Ferritic Steel
Authors: Farha Mizana Shamsudin, Shahidan Radiman, Yusof Abdullah, Nasri Abdul Hamid
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Oxide dispersion strengthened (ODS) ferritic steels are amongst the most promising candidates for large scale structural materials to be applied in next generation fission and fusion nuclear power reactors. This kind of material is relatively stable at high temperature, possess remarkable mechanical properties and comparatively good resistance from neutron radiation damage. The superior performance of ODS ferritic steels over their conventional properties is attributed to the high number density of nano-sized dispersoids that act as nucleation sites and stable sinks for many small helium bubbles resulting from irradiation, and also as pinning points to dislocation movement and grain growth. ODS ferritic steels are usually produced by powder metallurgical routes involving mechanical alloying (MA) process of Y2O3 and pre-alloyed or elemental metallic powders, and then consolidated by hot isostatic pressing (HIP) or hot extrusion (HE) techniques. In this study, Fe-14Cr-3W-0.5Ti-0.3Y₂O₃ (designated as 14YWT) was produced by mechanical alloying process and followed by hot isostatic pressing (HIP) technique. Crystal structure and morphology of this sample were identified and characterized by using X-ray Diffraction (XRD) and field emission scanning electron microscope (FESEM) respectively. The magnetic measurement of this sample at room temperature was carried out by using a vibrating sample magnetometer (VSM). FESEM micrograph revealed a homogeneous microstructure constituted by fine grains of less than 650 nm in size. The ultra-fine dispersoids of size between 5 nm to 19 nm were observed homogeneously distributed within the BCC matrix. The EDS mapping reveals that the dispersoids contain Y-Ti-O nanoclusters and from the magnetization curve plotted by VSM, this sample approaches the behavior of soft ferromagnetic materials. In conclusion, ODS Fe-14Cr-3W-0.5Ti-0.3Y₂O₃ (14YWT) ferritic steel was successfully produced by HIP technique in this present study.Keywords: hot isostatic pressing, magnetization, microstructure, ODS ferritic steel
Procedia PDF Downloads 3111317 Designing of Induction Motor Efficiency Monitoring System
Authors: Ali Mamizadeh, Ires Iskender, Saeid Aghaei
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Energy is one of the important issues with high priority property in the world. Energy demand is rapidly increasing depending on the growing population and industry. The useable energy sources in the world will be insufficient to meet the need for energy. Therefore, the efficient and economical usage of energy sources is getting more importance. In a survey conducted among electric consuming machines, the electrical machines are consuming about 40% of the total electrical energy consumed by electrical devices and 96% of this consumption belongs to induction motors. Induction motors are the workhorses of industry and have very large application areas in industry and urban systems like water pumping and distribution systems, steel and paper industries and etc. Monitoring and the control of the motors have an important effect on the operating performance of the motor, driver selection and replacement strategy management of electrical machines. The sensorless monitoring system for monitoring and calculating efficiency of induction motors are studied in this study. The equivalent circuit of IEEE is used in the design of this study. The terminal current and voltage of induction motor are used in this motor to measure the efficiency of induction motor. The motor nameplate information and the measured current and voltage are used in this system to calculate accurately the losses of induction motor to calculate its input and output power. The efficiency of the induction motor is monitored online in the proposed method without disconnecting the motor from the driver and without adding any additional connection at the motor terminal box. The proposed monitoring system measure accurately the efficiency by including all losses without using torque meter and speed sensor. The monitoring system uses embedded architecture and does not need to connect to a computer to measure and log measured data. The conclusion regarding the efficiency, the accuracy and technical and economical benefits of the proposed method are presented. The experimental verification has been obtained on a 3 phase 1.1 kW, 2-pole induction motor. The proposed method can be used for optimal control of induction motors, efficiency monitoring and motor replacement strategy.Keywords: induction motor, efficiency, power losses, monitoring, embedded design
Procedia PDF Downloads 3411316 Application Case and Result Consideration About Basic and Working Design of Floating PV Generation System Installed in the Upstream of Dam
Authors: Jang-Hwan Yin, Hae-Jeong Jeong, Hyo-Geun Jeong
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K-water (Korea Water Resources Corporation) conducted basic and working design about floating PV generation system installed above water in the upstream of dam to develop clean energy using water with importance of green growth is magnified ecumenically. PV Generation System on the ground applied considerably until now raise environmental damage by using farmland and forest land, PV generation system on the building roof is already installed at almost the whole place of business and additional installation is almost impossible. Installation space of PV generation system is infinite and efficient national land use is possible because it is installed above water. Also, PV module's efficiency increase by natural water cooling method and no shade. So it is identified that annual power generation is more than PV generation system on the ground by operating performance data. Although it is difficult to design and construct by high cost, little application case, difficult installation of floater, mooring device, underwater cable, etc. However, it has been examined cost reduction plan such as structure weight lightening, floater optimal design, etc. This thesis described basic and working design result systematically about K-water's floating PV generation system development and suggested optimal design method of floating PV generation system. Main contents are photovoltaic array location select, substation location select related underwater cable, PV module and inverter design, transmission and substation equipment design, floater design related structure weight lightening, mooring system design related water level fluctuation, grid connecting technical review, remote control and monitor equipment design, etc. This thesis will contribute to optimal design and business extension of floating PV generation system, and it will be opportunity revitalize clean energy development using water.Keywords: PV generation system, clean energy, green growth, solar energy
Procedia PDF Downloads 4051315 Eco-Design of Construction Industrial Park in China with Selection of Candidate Tenants
Authors: Yang Zhou, Kaijian Li, Guiwen Liu
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Offsite construction is an innovative alternative to conventional site-based construction, with wide-ranging benefits. It requires building components, elements or modules were prefabricated and pre-assembly before installed into their final locations. To improve efficiency and achieve synergies, in recent years, construction companies were clustered into construction industrial parks (CIPs) in China. A CIP is a community of construction manufacturing and service businesses located together on a common property. Companies involved in industrial clusters can obtain environment and economic benefits by sharing resources and information in a given region. Therefore, the concept of industrial symbiosis (IS) can be applied to the traditional CIP to achieve sustainable industrial development or redevelopment through the implementation of eco-industrial parks (EIP). However, before designing a symbiosis network between companies in a CIP, candidate support tenants need to be selected to complement the existing construction companies. In this study, an access indicator system and a linear programming model are established to select candidate tenants in a CIP while satisfying the degree of connectivity among the enterprises in the CIP, minimizing the environmental impact, and maximizing the annualized profit of the CIP. The access indicator system comprises three primary indicators and fifteen secondary indicators, is proposed from the perspective of park-based level. The fifteen indicators are classified as three primary indicators including industrial symbiosis, environment performance and economic benefit, according to the three dimensions of sustainability (environment, economic and social dimensions) and the three R's of the environment (reduce, reuse and recycle). The linear programming model is a method to assess the satisfactoriness of all the indicators and to make an optimal multi-objective selection among candidate tenants. This method provides a practical tool for planners of a CIP in evaluating which among the candidate tenants would best complement existing anchor construction tenants. The reasonability and validity of the indicator system and the method is worth further study in the future.Keywords: construction industrial park, China, industrial symbiosis, offsite construction, selection of support tenants
Procedia PDF Downloads 2651314 Spray Drying and Physico-Chemical Microbiological Evaluation of Ethanolic Extracts of Propolis
Authors: David Guillermo Piedrahita Marquez, Hector Suarez Mahecha, Jairo Humberto Lopez
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The propolis are substances obtained from the beehive have an action against pathogens, prooxidant substances and free radicals because of its polyphenols content, this has motivated the use of these compounds in the food and pharmaceutical industries. However, due to their organoleptic properties and their ability to react with other compounds, their application has been limited; therefore, the objective of this research was to propose a mechanism to protect propolis and mitigate side effects granted by its components. To achieve the stated purpose ethanolic extracts of propolis (EEP) from three samples from Santander were obtained and their antioxidant and antimicrobial activity were evaluated in order to choose the extract with the biggest potential. Subsequently mixtures of the extract with maltodextrin were prepared by spray drying varying concentration and temperature, finally the yield, the physicochemical, and antioxidant properties of the products were measured. It was concluded that Socorro propolis was the best for the production of microencapsulated due to their activity against pathogenic strains, for its large percentage of DPPH radical inactivation and for its high phenolic content. In spray drying, the concentration of bioactive had a greater impact than temperature and the conditions set allowed a good performance and the production of particles with high antioxidant potential and little chance of proliferation of microorganisms. Also, it was concluded that the best conditions that allowed us to obtain the best particles were obtained after drying a mixture 1:2 ( EEP: Maltodextrin), besides the concentration is the most important variable in the spray drying process, at the end we obtained particles of different sizes and shape and the uniformity of the surface depend on the temperature. After watching the previously mentioned microparticles by scanning electron microscopy (SEM) it was concluded that most of the particles produced during the spray dry process had a spherical shape and presented agglomerations due to the moisture content of the ethanolic extracts of propolis (EEP), the morphology of the microparticles contributed to the stability of the final product and reduce the loss of total phenolic content.Keywords: spray drying, propolis, maltodextrin, encapsulation, scanning electron microscopy
Procedia PDF Downloads 2851313 Automatic Processing of Trauma-Related Visual Stimuli in Female Patients Suffering From Post-Traumatic Stress Disorder after Interpersonal Traumatization
Authors: Theresa Slump, Paula Neumeister, Katharina Feldker, Carina Y. Heitmann, Thomas Straube
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A characteristic feature of post-traumatic stress disorder (PTSD) is the automatic processing of disorder-specific stimuli that expresses itself in intrusive symptoms such as intense physical and psychological reactions to trauma-associated stimuli. That automatic processing plays an essential role in the development and maintenance of symptoms. The aim of our study was, therefore, to investigate the behavioral and neural correlates of automatic processing of trauma-related stimuli in PTSD. Although interpersonal traumatization is a form of traumatization that often occurs, it has not yet been sufficiently studied. That is why, in our study, we focused on patients suffering from interpersonal traumatization. While previous imaging studies on PTSD mainly used faces, words, or generally negative visual stimuli, our study presented complex trauma-related and neutral visual scenes. We examined 19 female subjects suffering from PTSD and examined 19 healthy women as a control group. All subjects did a geometric comparison task while lying in a functional-magnetic-resonance-imaging (fMRI) scanner. Trauma-related scenes and neutral visual scenes that were not relevant to the task were presented while the subjects were doing the task. Regarding the behavioral level, there were not any significant differences between the task performance of the two groups. Regarding the neural level, the PTSD patients showed significant hyperactivation of the hippocampus for task-irrelevant trauma-related stimuli versus neutral stimuli when compared with healthy control subjects. Connectivity analyses revealed altered connectivity between the hippocampus and other anxiety-related areas in PTSD patients, too. Overall, those findings suggest that fear-related areas are involved in PTSD patients' processing of trauma-related stimuli even if the stimuli that were used in the study were task-irrelevant.Keywords: post-traumatic stress disorder, automatic processing, hippocampus, functional magnetic resonance imaging
Procedia PDF Downloads 1931312 Chemical Aging of High-Density Polyethylene (HDPE-100) in Interaction with Aggressive Environment
Authors: Berkas Khaoula, Chaoui Kamel
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Polyethylene (PE) pipes are one of the best options for water and gas transmission networks. The main reason for such a choice is its high-quality performance in service conditions over long periods of time. PE pipes are installed in contact with different soils having various chemical compositions with confirmed aggressiveness. As a result, PE pipe surfaces undergo unwanted oxidation reactions. Usually, the polymer mixture is designed to include some additives, such as anti-oxidants, to inhibit or reduce the degradation effects. Some other additives are intended to increase resistance to the ESC phenomenon associated with polymers (ESC: Environmental Stress Cracking). This situation occurs in contact with aggressive external environments following different contaminations of soil, groundwater and transported fluids. In addition, bacterial activity and other physical or chemical media, such as temperature and humidity, can play an enhancing role. These conditions contribute to modifying the PE pipe structure and degrade its properties during exposure. In this work, the effect of distilled water, sodium hypochlorite (bleach), diluted sulfuric acid (H2SO4) and toluene-methanol (TM) mixture are studied when extruded PE samples are exposed to those environments for given periods. The chosen exposure periods are 7, 14 and 28 days at room temperature and in sealed glass containers. Post-exposure observations and ISO impact tests are presented as a function of time and chemical medium. Water effects are observed to be limited in explaining such use in real applications, whereas the changes in TM and acidic media are very significant. For the TM medium, the polymer toughness increased drastically (from 15.95 kJ/m² up to 32.01 kJ/m²), while sulfuric acid showed a steady augmentation over time. This situation may correspond to a hardening phenomenon of PE increasing its brittleness and its ability for structural degradation because of localized oxidation reactions and changes in crystallinity.Keywords: polyethylene, toluene-methanol mixture, environmental stress cracking, degradation, impact resistance
Procedia PDF Downloads 701311 Lead-Free Inorganic Cesium Tin-Germanium Triiodide Perovskites for Photovoltaic Application
Authors: Seyedeh Mozhgan Seyed-Talebi, Javad Beheshtian
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The toxicity of lead associated with the lifecycle of perovskite solar cells (PSCs( is a serious concern which may prove to be a major hurdle in the path toward their commercialization. The current proposed lead-free PSCs including Ag(I), Bi(III), Sb(III), Ti(IV), Ge(II), and Sn(II) low-toxicity cations are still plagued with the critical issues of poor stability and low efficiency. This is mainly because of their chemical stability. In the present research, utilization of all inorganic CsSnGeI3 based materials offers the advantages to enhance resistance of device to degradation, reduce the cost of cells, and minimize the carrier recombination. The presence of inorganic halide perovskite improves the photovoltaic parameters of PCSs via improved surface coverage and stability. The inverted structure of simulated devices using a 1D simulator like solar cell capacitance simulator (SCAPS) version 3308 involves TCOHTL/Perovskite/ETL/Au contact layer. PEDOT:PSS, PCBM, and CsSnGeI3 used as hole transporting layer (HTL), electron transporting layer (ETL), and perovskite absorber layer in the inverted structure for the first time. The holes are injected from highly stable and air tolerant Sn0.5Ge0.5I3 perovskite composition to HTM and electrons from the perovskite to ETL. Simulation results revealed a great dependence of power conversion efficiency (PCE) on the thickness and defect density of perovskite layer. Here the effect of an increase in operating temperature from 300 K to 400 K on the performance of CsSnGeI3 based perovskite devices is investigated. Comparison between simulated CsSnGeI3 based PCSs and similar real testified devices with spiro-OMeTAD as HTL showed that the extraction of carriers at the interfaces of perovskite absorber depends on the energy level mismatches between perovskite and HTL/ETL. We believe that optimization results reported here represent a critical avenue for fabricating the stable, low-cost, efficient, and eco-friendly all-inorganic Cs-Sn-Ge based lead-free perovskite devices.Keywords: hole transporting layer, lead-free, perovskite solar cell, SCAPS-1D, Sn-Ge based
Procedia PDF Downloads 1481310 Effectiveness of Metacognitive Skills in Comprehension Instruction for Elementary Students
Authors: Mahdi Taheri Asl
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Using a variety of strategies to read text plays an important role to make students strategic independent, strategic, and metacognitive readers. Given the importance of comprehension instruction (CI), it is essential to support the fostering comprehension skills at elementary age students, particularly those who struggle with or dislike reading. One of the main components of CI is activating metacognitive skills, which double function of elementary students. Thus, it’s important to evaluate the implemented comprehension interventions to inform reading specialist and teachers. There has been limited review research in the area of CI, so the conduction review research is required. The purpose of this review is to examine the effectiveness of metacognitive reading strategies in a regular classroom environment with elementary aged students. We develop five inclusion criteria to identify researches relevant to our research. First, the article had to be published in a peer-reviewed journal from 2000 to 2023. second, the study had to include participants in elementary school it could include of special education students. Third, the intervention needed to be involved with metacognitive strategies. Fourth, the articles had to use experimental or quasi experimental design. The last one needed to include measurement of reading performance in pre and post intervention. We used computer data-based site like Eric, PsychoINFO, and google scholar to search for articles that met these criteria. we used the following search terms: comprehension instruction, meta cognitive strategies, and elementary school. The next step was to do an ancestral search that get in reviewing the relevant studies cited in the articles that were found in the database search. We identified 30studies in the initial searches. After coding agreement, we synthesized 13 with respect to the participant, setting, research design, dependent variables, measures, the intervention used by instructors, and general outcomes. The finding show metacognitive strategies were effective to empower student’s comprehension skills. It also showed that linguistic instruction will be effective if got mixed with metacognitive strategies. The research provides a useful view into reading intervention. Despite the positive effect of metacognitive instruction on students’ comprehension skills, it is not widely used in classroom.Keywords: comprehension instruction, metacogntion, metacognitive skills, reading intervention
Procedia PDF Downloads 681309 New Environmentally Friendly Material for the Purification of the Fresh Water from Oil Pollution
Authors: M. A. Ashour
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As it is known Egypt is one of the countries having oldest sugarcane industry, which goes back to the year 710 AD. Cane plantations are the main agricultural product in five governorates in Upper Egypt (El-Menia, Sohag, Qena, Luxor, and Aswan), producing not less than 16 million tons a year. Eight factories (Abou-korkas, Gena, Nagaa-Hamadi, Deshna, Kous, Armant, Edfuo, and Komombo), located in such upper Egypt governorates generates huge amount of wastes during the manufacturing stage, the so called bagasse which is the fibrous, and cellulosic materials remaining after the era of the sugarcane and the juice extraction, presents about 30% of such wastes. The amount of bagasse generated yearly through the manufacturing stage of the above mentioned 8 factories is approximately about 2.8 million tons, getting red safely of such huge amount, presents a serious environmental problem. Storage of that material openly in the so hot climate in upper Egypt, may cause its self-ignition under air temperature reaches 50 degrees centigrade in summer, due to the remained residual content of sugar. At the same time preparing places for safely storage for such amount is very expensive with respect to the valueless of it. So the best way for getting rid of bagasse is converting it into an added value environmentally friendly material, especially till now the utilization of it is so limited. Since oil pollution became a serious concern, the issue of environmental cleaning arises. With the structure of sugarcane bagasse, which contains fiber and high content of carbon, it can be an adsorbent to adsorb the oil contamination from the water. The present study is a trail to introduce a new material for the purification of water systems to score two goals at once, the first is getting rid of that harmful waste safely, the second is converting it to a commercial valuable material for cleaning, and purifying the water from oil spills, and petroleum pollution. Introduced the new material proved very good performance, and higher efficiency than other similar materials available in the local market, in both closed and open systems. The introduced modified material can absorb 10 times its weight of oil, while don't absorb any water.Keywords: environment, water resources, agricultural wastes, oil pollution control, sugarcane
Procedia PDF Downloads 1811308 Streamlining .NET Data Access: Leveraging JSON for Data Operations in .NET
Authors: Tyler T. Procko, Steve Collins
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New features in .NET (6 and above) permit streamlined access to information residing in JSON-capable relational databases, such as SQL Server (2016 and above). Traditional methods of data access now comparatively involve unnecessary steps which compromise system performance. This work posits that the established ORM (Object Relational Mapping) based methods of data access in applications and APIs result in common issues, e.g., object-relational impedance mismatch. Recent developments in C# and .NET Core combined with a framework of modern SQL Server coding conventions have allowed better technical solutions to the problem. As an amelioration, this work details the language features and coding conventions which enable this streamlined approach, resulting in an open-source .NET library implementation called Codeless Data Access (CODA). Canonical approaches rely on ad-hoc mapping code to perform type conversions between the client and back-end database; with CODA, no mapping code is needed, as JSON is freely mapped to SQL and vice versa. CODA streamlines API data access by improving on three aspects of immediate concern to web developers, database engineers and cybersecurity professionals: Simplicity, Speed and Security. Simplicity is engendered by cutting out the “middleman” steps, effectively making API data access a whitebox, whereas traditional methods are blackbox. Speed is improved because of the fewer translational steps taken, and security is improved as attack surfaces are minimized. An empirical evaluation of the speed of the CODA approach in comparison to ORM approaches ] is provided and demonstrates that the CODA approach is significantly faster. CODA presents substantial benefits for API developer workflows by simplifying data access, resulting in better speed and security and allowing developers to focus on productive development rather than being mired in data access code. Future considerations include a generalization of the CODA method and extension outside of the .NET ecosystem to other programming languages.Keywords: API data access, database, JSON, .NET core, SQL server
Procedia PDF Downloads 611307 Assessment of the Performance of the Sonoreactors Operated at Different Ultrasound Frequencies, to Remove Pollutants from Aqueous Media
Authors: Gabriela Rivadeneyra-Romero, Claudia del C. Gutierrez Torres, Sergio A. Martinez-Delgadillo, Victor X. Mendoza-Escamilla, Alejandro Alonzo-Garcia
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Ultrasonic degradation is currently being used in sonochemical reactors to degrade pollutant compounds from aqueous media, as emerging contaminants (e.g. pharmaceuticals, drugs and personal care products.) because they can produce possible ecological impacts on the environment. For this reason, it is important to develop appropriate water and wastewater treatments able to reduce pollution and increase reuse. Pollutants such as textile dyes, aromatic and phenolic compounds, cholorobenzene, bisphenol-A and carboxylic acid and other organic pollutants, can be removed from wastewaters by sonochemical oxidation. The effect on the removal of pollutants depends on the type of the ultrasonic frequency used; however, not much studies have been done related to the behavior of the fluid into the sonoreactors operated at different ultrasonic frequencies. Based on the above, it is necessary to study the hydrodynamic behavior of the liquid generated by the ultrasonic irradiation to design efficient sonoreactors to reduce treatment times and costs. In this work, it was studied the hydrodynamic behavior of the fluid in sonochemical reactors at different frequencies (250 kHz, 500 kHz and 1000 kHz). The performances of the sonoreactors at those frequencies were simulated using computational fluid dynamics (CFD). Due to there is great sound speed gradient between piezoelectric and fluid, k-e models were used. Piezoelectric was defined as a vibration surface, to evaluate the different frequencies effect on the fluid into sonochemical reactor. Structured hexahedral cells were used to mesh the computational liquid domain, and fine triangular cells were used to mesh the piezoelectric transducers. Unsteady state conditions were used in the solver. Estimation of the dissipation rate, flow field velocities, Reynolds stress and turbulent quantities were evaluated by CFD and 2D-PIV measurements. Test results show that there is no necessary correlation between an increase of the ultrasonic frequency and the pollutant degradation, moreover, the reactor geometry and power density are important factors that should be considered in the sonochemical reactor design.Keywords: CFD, reactor, ultrasound, wastewater
Procedia PDF Downloads 1861306 Identifying the Factors that Influence Water-Use Efficiency in Agriculture: Case Study in a Spanish Semi-Arid Region
Authors: Laura Piedra-Muñoz, Ángeles Godoy-Durán, Emilio Galdeano-Gómez, Juan C. Pérez-Mesa
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The current agricultural system in some arid and semi-arid areas is not sustainable in the long term. In southeast Spain, groundwater is the main water source and is overexploited, while alternatives like desalination are still limited. The Water Plan for the Mediterranean Basins 2015-2020 indicates a global deficit of 73.42 hm3 and an overexploitation of the aquifers of 205.58hm3. In order to solve this serious problem, two major actions can be taken: increasing available water, and/or improving the efficiency of its use. This study focuses on the latter. The main aim of this study is to present the major factors related to water usage efficiency in farming. It focuses on Almería province, southeast Spain, one of the most arid areas of the country, and in particular on family farms as the main direct managers of water use in this zone. Many of these farms are among the most water efficient in Spanish agriculture, but this efficiency is not generalized throughout the sector. This work conducts a comprehensive assessment of water performance in this area, using on-farm water-use, structural, socio-economic and environmental information. Two statistical techniques are used: descriptive analysis and cluster analysis. Thus, two groups are identified: the least and the most efficient farms regarding water usage. By analyzing both the common characteristics within each group and the differences between the groups with a one-way ANOVA analysis, several conclusions can be reached. The main differences between the two clusters center on the extent to which innovation and new technologies are used in irrigation. The most water efficient farms are characterized by more educated farmers, a greater degree of innovation, new irrigation technology, specialized production and awareness of water issues and environmental sustainability. The research shows that better practices and policies can have a substantial impact on achieving a more sustainable and efficient use of water. The findings of this study can be extended to farms in similar arid and semi-arid areas and contribute to foster appropriate policies to improve the efficiency of water usage in the agricultural sector.Keywords: cluster analysis, family farms, Spain, water-use efficiency
Procedia PDF Downloads 2831305 Effect of Punch Diameter on Optimal Loading Profiles in Hydromechanical Deep Drawing Process
Authors: Mehmet Halkaci, Ekrem Öztürk, Mevlüt Türköz, H. Selçuk Halkacı
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Hydromechanical deep drawing (HMD) process is an advanced manufacturing process used to form deep parts with only one forming step. In this process, sheet metal blank can be drawn deeper by means of fluid pressure acting on sheet surface in the opposite direction of punch movement. High limiting drawing ratio, good surface quality, less springback characteristic and high dimensional accuracy are some of the advantages of this process. The performance of the HMD process is affected by various process parameters such as fluid pressure, blank holder force, punch-die radius, pre-bulging pressure and height, punch diameter, friction between sheet-die and sheet-punch. The fluid pressure and bank older force are the main loading parameters and affect the formability of HMD process significantly. The punch diameter also influences the limiting drawing ratio (the ratio of initial sheet diameter to punch diameter) of the sheet metal blank. In this research, optimal loading (fluid pressure and blank holder force) profiles were determined for AA 5754-O sheet material through fuzzy control algorithm developed in previous study using LS-DYNA finite element analysis (FEA) software. In the preceding study, the fuzzy control algorithm was developed utilizing geometrical criteria such as thinning and wrinkling. In order to obtain the final desired part with the developed algorithm in terms of the punch diameter requested, the effect of punch diameter, which is the one of the process parameters, on loading profiles was investigated separately using blank thickness of 1 mm. Thus, the practicality of the previously developed fuzzy control algorithm with different punch diameters was clarified. Also, thickness distributions of the sheet metal blank along a curvilinear distance were compared for the FEA in which different punch diameters were used. Consequently, it was found that the use of different punch diameters did not affect the optimal loading profiles too much.Keywords: Finite Element Analysis (FEA), fuzzy control, hydromechanical deep drawing, optimal loading profiles, punch diameter
Procedia PDF Downloads 4261304 MIMO Radar-Based System for Structural Health Monitoring and Geophysical Applications
Authors: Davide D’Aria, Paolo Falcone, Luigi Maggi, Aldo Cero, Giovanni Amoroso
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The paper presents a methodology for real-time structural health monitoring and geophysical applications. The key elements of the system are a high performance MIMO RADAR sensor, an optical camera and a dedicated set of software algorithms encompassing interferometry, tomography and photogrammetry. The MIMO Radar sensor proposed in this work, provides an extremely high sensitivity to displacements making the system able to react to tiny deformations (up to tens of microns) with a time scale which spans from milliseconds to hours. The MIMO feature of the system makes the system capable of providing a set of two-dimensional images of the observed scene, each mapped on the azimuth-range directions with noticeably resolution in both the dimensions and with an outstanding repetition rate. The back-scattered energy, which is distributed in the 3D space, is projected on a 2D plane, where each pixel has as coordinates the Line-Of-Sight distance and the cross-range azimuthal angle. At the same time, the high performing processing unit allows to sense the observed scene with remarkable refresh periods (up to milliseconds), thus opening the way for combined static and dynamic structural health monitoring. Thanks to the smart TX/RX antenna array layout, the MIMO data can be processed through a tomographic approach to reconstruct the three-dimensional map of the observed scene. This 3D point cloud is then accurately mapped on a 2D digital optical image through photogrammetric techniques, allowing for easy and straightforward interpretations of the measurements. Once the three-dimensional image is reconstructed, a 'repeat-pass' interferometric approach is exploited to provide the user of the system with high frequency three-dimensional motion/vibration estimation of each point of the reconstructed image. At this stage, the methodology leverages consolidated atmospheric correction algorithms to provide reliable displacement and vibration measurements.Keywords: interferometry, MIMO RADAR, SAR, tomography
Procedia PDF Downloads 1861303 Morphology Evolution in Titanium Dioxide Nanotubes Arrays Prepared by Electrochemical Anodization
Authors: J. Tirano, H. Zea, C. Luhrs
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Photocatalysis has established as viable option in the development of processes for the treatment of pollutants and clean energy production. This option is based on the ability of semiconductors to generate an electron flow by means of the interaction with solar radiation. Owing to its electronic structure, TiO₂ is the most frequently used semiconductors in photocatalysis, although it has a high recombination of photogenerated charges and low solar energy absorption. An alternative to reduce these limitations is the use of nanostructured morphologies which can be produced during the synthesis of TiO₂ nanotubes (TNTs). Therefore, if possible to produce vertically oriented nanostructures it will be possible to generate a greater contact area with electrolyte and better charge transfer. At present, however, the development of these innovative structures still presents an important challenge for the development of competitive photoelectrochemical devices. This research focuses on established correlations between synthesis variables and 1D nanostructure morphology which has a direct effect on the photocatalytic performance. TNTs with controlled morphology were synthesized by two-step potentiostatic anodization of titanium foil. The anodization was carried out at room temperature in an electrolyte composed of ammonium fluoride, deionized water and ethylene glycol. Consequent thermal annealing of as-prepared TNTs was conducted in the air between 450 °C-550 °C. Morphology and crystalline phase of the TNTs were carried out by SEM, EDS and XRD analysis. As results, the synthesis conditions were established to produce nanostructures with specific morphological characteristics. Anatase was the predominant phase of TNTs after thermal treatment. Nanotubes with 10 μm in length, 40 nm in pore diameter and a surface-volume ratio of 50 are important in photoelectrochemical applications based on TiO₂ due to their 1D characteristics, high surface-volume ratio, reduced radial dimensions and high oxide/electrolyte interface. Finally, this knowledge can be used to improve the photocatalytic activity of TNTs by making additional surface modifications with dopants that improve their efficiency.Keywords: electrochemical anodization, morphology, self-organized nanotubes, TiO₂ nanotubes
Procedia PDF Downloads 1471302 Study of the Influence of Refractory Nitride Additives on Hydrogen Storage Properties of Ti6Al4V-Based Materials Produced by Spark Plasma Sintering
Authors: John Olorunfemi Abe, Olawale Muhammed Popoola, Abimbola Patricia Idowu Popoola
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Hydrogen is an appealing alternative to fossil fuels because of its abundance, low weight, high energy density, and relative lack of contaminants. However, its low density presents a number of storage challenges. Therefore, this work studies the influence of refractory nitride additives consisting of 5 wt. % each of hexagonal boron nitride (h-BN), titanium nitride (TiN), and aluminum nitride (AlN) on hydrogen storage and electrochemical characteristics of Ti6Al4V-based materials produced by spark plasma sintering. The microstructure and phase constituents of the sintered materials were characterized using scanning electron microscopy (in conjunction with energy-dispersive spectroscopy) and X-ray diffraction, respectively. Pressure-composition-temperature (PCT) measurements were used to assess the hydrogen absorption/desorption behavior, kinetics, and storage capacities of the sintered materials, respectively. The pure Ti6Al4V alloy displayed a two-phase (α+β) microstructure, while the modified composites exhibited apparent microstructural modifications with the appearance of nitride-rich secondary phases. It is found that the diffusion process controls the kinetics of the hydrogen absorption. Thus, a faster rate of hydrogen absorption at elevated temperatures ensued. The additives acted as catalysts, lowered the activation energy and accelerated the rate of hydrogen sorption in the composites relative to the monolithic alloy. Ti6Al4V-5 wt. % h-BN appears to be the most promising candidate for hydrogen storage (2.28 wt. %), followed by Ti6Al4V-5 wt. % TiN (2.09 wt. %), whereas Ti6Al4V-5 wt. % AlN shows the least hydrogen storage performance (1.35 wt. %). Accordingly, the developed hydride system (Ti6Al4V-5h-BN) may be competitive for use in applications involving short-range continuous vehicles (~50-100km) as well as stationary applications such as electrochemical devices, large-scale storage cylinders in hydrogen production locations, and hydrogen filling stations.Keywords: hydrogen storage, Ti6Al4V hydride system, pressure-composition-temperature measurements, refractory nitride additives, spark plasma sintering, Ti6Al4V-based materials
Procedia PDF Downloads 551301 Thermal Behaviour of a Low-Cost Passive Solar House in Somerset East, South Africa
Authors: Ochuko K. Overen, Golden Makaka, Edson L. Meyer, Sampson Mamphweli
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Low-cost housing provided for people with small incomes in South Africa are characterized by poor thermal performance. This is due to inferior craftsmanship with no regard to energy efficient design during the building process. On average, South African households spend 14% of their total monthly income on energy needs, in particular space heating; which is higher than the international benchmark of 10% for energy poverty. Adopting energy efficient passive solar design strategies and superior thermal building materials can create a stable thermal comfort environment indoors. Thereby, reducing energy consumption for space heating. The aim of this study is to analyse the thermal behaviour of a low-cost house integrated with passive solar design features. A low-cost passive solar house with superstructure fly ash brick walls was designed and constructed in Somerset East, South Africa. Indoor and outdoor meteorological parameters of the house were monitored for a period of one year. The ASTM E741-11 Standard was adopted to perform ventilation test in the house. In summer, the house was found to be thermally comfortable for 66% of the period monitored, while for winter it was about 79%. The ventilation heat flow rate of the windows and doors were found to be 140 J/s and 68 J/s, respectively. Air leakage through cracks and openings in the building envelope was 0.16 m3/m2h with a corresponding ventilation heat flow rate of 24 J/s. The indoor carbon dioxide concentration monitored overnight was found to be 0.248%, which is less than the maximum range limit of 0.500%. The prediction percentage dissatisfaction of the house shows that 86% of the occupants will express the thermal satisfaction of the indoor environment. With a good operation of the house, it can create a well-ventilated, thermal comfortable and nature luminous indoor environment for the occupants. Incorporating passive solar design in low-cost housing can be one of the long and immediate solutions to the energy crisis facing South Africa.Keywords: energy efficiency, low-cost housing, passive solar design, rural development, thermal comfort
Procedia PDF Downloads 2551300 An ANOVA-based Sequential Forward Channel Selection Framework for Brain-Computer Interface Application based on EEG Signals Driven by Motor Imagery
Authors: Forouzan Salehi Fergeni
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Converting the movement intents of a person into commands for action employing brain signals like electroencephalogram signals is a brain-computer interface (BCI) system. When left or right-hand motions are imagined, different patterns of brain activity appear, which can be employed as BCI signals for control. To make better the brain-computer interface (BCI) structures, effective and accurate techniques for increasing the classifying precision of motor imagery (MI) based on electroencephalography (EEG) are greatly needed. Subject dependency and non-stationary are two features of EEG signals. So, EEG signals must be effectively processed before being used in BCI applications. In the present study, after applying an 8 to 30 band-pass filter, a car spatial filter is rendered for the purpose of denoising, and then, a method of analysis of variance is used to select more appropriate and informative channels from a category of a large number of different channels. After ordering channels based on their efficiencies, a sequential forward channel selection is employed to choose just a few reliable ones. Features from two domains of time and wavelet are extracted and shortlisted with the help of a statistical technique, namely the t-test. Finally, the selected features are classified with different machine learning and neural network classifiers being k-nearest neighbor, Probabilistic neural network, support-vector-machine, Extreme learning machine, decision tree, Multi-layer perceptron, and linear discriminant analysis with the purpose of comparing their performance in this application. Utilizing a ten-fold cross-validation approach, tests are performed on a motor imagery dataset found in the BCI competition III. Outcomes demonstrated that the SVM classifier got the greatest classification precision of 97% when compared to the other available approaches. The entire investigative findings confirm that the suggested framework is reliable and computationally effective for the construction of BCI systems and surpasses the existing methods.Keywords: brain-computer interface, channel selection, motor imagery, support-vector-machine
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