Search results for: pedagogical materials
5954 Ge₁₋ₓSnₓ Alloys with Tuneable Energy Band Gap on GaAs (100) Substrate Manufactured by a Modified Magnetron Co-Sputtering
Authors: Li Qian, Jinchao Tong, Daohua Zhang, Weijun Fan, Fei Suo
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Photonic applications based on group IV semiconductors have always been an interest but also a challenge for the research community. We report manufacturing group IV Ge₁₋ₓSnₓ alloys with tuneable energy band gap on (100) GaAs substrate by a modified radio frequency magnetron co-sputtering. Images were taken by atomic force microscope, and scanning electron microscope clearly demonstrates a smooth surface profile, and Ge₁₋ₓSnₓ nano clusters are with the size of several tens of nanometers. Transmittance spectra were measured by Fourier Transform Infrared Spectroscopy that showed changing energy gaps with the variation in elementary composition. Calculation results by 8-band k.p method are consistent with measured gaps. Our deposition system realized direct growth of Ge₁₋ₓSnₓ thin film on GaAs (100) substrate by sputtering. This simple deposition method was modified to be able to grow high-quality photonic materials with tuneable energy gaps. This work provides an alternative and successful method for fabricating Group IV photonic semiconductor materials.Keywords: GeSn, crystal growth, sputtering, photonic
Procedia PDF Downloads 1445953 Effect of Nano-Alumina on the Mechanical Properties of Cold Recycled Asphalt
Authors: Shahab Hasani Nasab, Aran Aeini, Navid Kermanshahi
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In order to reduce road building costs and reduce environmental damage, recycled materials can be used instead of mineral materials in the production of asphalt mixtures. Today, in most parts of the world, cold recycled asphalt with bitumen emulsion, has acceptable results. However, Cold Recycled Asphalt have some deficiency such as stripping, thermal cracking, and rutting. This requires the addition of additives to reduce this deficiency of recycled pavement with emulsified asphalt. In this research, nano-alumina and emulsified asphalt were used to modify the properties of recycled asphalt mixtures according to the technical specifications and the operation of cold recycling. Marshall test methods, dynamic creep test, and resiliency modulus test has been used to obtain the nano-alumina’s effects on asphalt mixture properties. The results show that the addition of nano-alumina would reduce the Marshall stability in samples but increases the rutting resistance. The resiliency modulus increases significantly with this additive.Keywords: cold asphalt, cold recycling, nano-alumina, dynamic creep, bitumen emulsion
Procedia PDF Downloads 1645952 A Study on the Pressure Void Ratio Relationship for Waste Material
Authors: Aktan Ozsoy, Ali Fırat Cabalar, Eyyub Karakan
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Climate change is one of the biggest issues facing communities. Increasing population, growing economies, rapid industrialization are the main factors triggering it. On the other hand, the millions of tons of waste have generated by the period of rapid global growth not only harm to the environment but also lead to the use of valuable lands around the world as landfill sites. Moreover, it is rapidly consuming our resources and this forcing the human population and wildlife to share increasingly shrinking space. In this direction, it is vital to reuse waste materials with a sustainability philosophy. This study was carried out to contribute to the combat against climate change, conserve our natural resources and the environment. An oedometer (consolidation) test was performed on two waste materials combined in certain proportions to evaluate their sustainable usage. Crushed brick (BD) was mixed with rock powder (RP) in 0, 5, 10, 20, 30, 40, and 50% (dry weight of soil). The results obtained revealed the importance of the gradation of the material used in the consolidation test. It was found that there was a negligible difference between the initial and final void ratio of mixtures with brick dust added.Keywords: waste material, oedometer test, environmental geotechnics, sustainability
Procedia PDF Downloads 735951 Adsorptive Membrane for Hemodialysis: Potential, Future Prospection and Limitation of MOF as Nanofillers
Authors: Musawira Iftikhar
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The field of membrane materials is the most dynamic due to the constantly evolving requirements advancement of materials, to address challenges such as biocompatibility, protein-bound uremic toxins, blood coagulation, auto-immune responses, oxidative stress, and poor clearance of uremic toxins. Hemodialysis is a membrane filtration processes that is currently necessary for daily living of the patients with ESRD. Tens of millions of people with ESRD have benefited from hemodialysis over the past 60–70 years, both in terms of safeguarding life and a longer lifespan. Beyond challenges associated with the efficiency and separative properties of the membranes, ensuring hemocompatibility, or the safe circulation of blood outside the body for four hours every two days, remains a persistent challenge. This review explores the ongoing field of metal–Organic Frameworks (MOFs) and their applications in hemodialysis, offering a comprehensive examination of various MOFs employed to address challenges inherent in traditional hemodialysis methodologies. this This review included includes the experimental work done with various MOFs as a filler such as UiO-66, HKUST-1, MIL-101, and ZIF-8, which together lead to improved adsorption capacities for a range of uremic toxins and proteins. Furthermore, this review highlights how effectively MOF-based hemodialysis membranes remove a variety of uremic toxins, including p-cresol, urea, creatinine, and indoxyl sulfate and potential filler choices for the future. Future research efforts should focus on refining synthesis techniques, enhancing toxin selectivity, and investigating the long-term durability of MOF-based membranes. With these considerations, MOFs emerge as transformative materials in the quest to develop advanced and efficient hemodialysis technologies, holding the promise to significantly enhance patient outcomes and redefine the landscape of renal therapy.Keywords: membrane, hemodailysis, metal organic frameworks, seperation, protein adsorbtion
Procedia PDF Downloads 565950 From Theory to Practice: Teaching Rhetorical Theory for Effective Argumentative Essay Writing
Authors: Mohammad Ahmadi
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Argumentative writing is a highly opinion-based form of discourse that necessitates the ability to address commonly held opinions (endoxa). To enhance the development of persuasive, argumentative essays, the incorporation of classical rhetorical theory, with a specific focus on topics related to the canon of Invention (inventio), can be advantageous. This research investigates the practical application of rhetorical theory in teaching students how to construct compelling argumentative essays. The fundamental premise of this study is the limited familiarity of rhetoric and composition students with rhetorical theory. Consequently, this paper presents an effective pedagogical approach to introduce rhetorical theory to students, beginning from a foundational level. It delineates the procedures and progression that educators should adopt to elucidate and facilitate students' comprehension of rhetorical theory while demonstrating its utilization in the writing of an argumentative essay.Keywords: argumentative essay, rhetorical theory, pedagogy, invention
Procedia PDF Downloads 795949 Metal-Organic Frameworks for Innovative Functional Textiles
Authors: Hossam E. Emam
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Metal–organic frameworks (MOFs) are new hybrid materials investigated from 15 years ago; they synthesized from metals as inorganic center joined with multidentate organic linkers to form a 1D, 2D or 3D network structure. MOFs have unique properties such as pore crystalline structure, large surface area, chemical tenability and luminescent characters. These significant properties enable MOFs to be applied in many fields such like gas storage, adsorption/separation, drug delivery/biomedicine, catalysis, polymerization, magnetism and luminescence applications. Recently, many of published reports interested in superiority of MOFs for functionalization of textiles to exploit the unique properties of MOFs. Incorporation of MOFs is found to acquire the textiles some additional formidable functions to be used in considerable fields such like water treatment and fuel purification. Modification of textiles with MOFs could be easily performed by two main techniques; Ex-situ (preparation of MOFs then applied onto textiles) and in-situ (ingrowth of MOFs within textiles networks). Uniqueness of MOFs could be assimilated in acquirement of decorative color, antimicrobial character, anti-mosquitos character, ultraviolet radiation protective, self-clean, photo-luminescent and sensor character. Additionally, textiles treatment with MOFs make it applicable as filter in the adsorption of toxic gases, hazardous materials (such as pesticides, dyes and aromatics molecules) and fuel purification (such as removal of oxygenated, nitrogenated and sulfur compounds). Also, the porous structure of MOFs make it mostly utilized in control release of insecticides from the surface of the textile. Moreover, MOF@textiles as recyclable materials lead it applicable as photo-catalyst composites for photo-degradation of different dyes in the day light. Therefore, MOFs is extensively considered for imparting textiles with formidable properties as ingeniousness way for textile functionalization.Keywords: MOF, functional textiles, water treatment, fuel purification, environmental applications
Procedia PDF Downloads 1455948 Electroless Nickel Boron Deposition onto the SiC and B4C Ceramic Reinforced Materials
Authors: I. Kerti, G. Sezen, S. Daglilar
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This present work is focused on studying to improve low wetting behaviour between liquid metal and ceramic particles. Ceramic particles like SiC and B4C have attracted great attention because of their usability as reinforcement for composite materials. However, poor wettability of particles is one of the major drawbacks of metal matrix composite production. Various methods have been studied to enhance the wetting properties between ceramic materials and metal substrates during ceramic reinforced metal matrix composites. Among these methods, autocatalytic nickel deposition is a unique process for the enhancement of the surface properties of ceramic particles. In fact, it is difficult to obtain continuous and uniform metallic coating on ceramic powders. In this study deposition of nickel boron layer on ceramic particles via autocatalytic plating in borohydride baths were investigated. Firstly, powders with different particle sizes were sensitized and activated respectively in order to ensure catalytic properties. Following the pre-treatment operations, particles were transferred into the coating bath containing nickel sulphate or nickel chloride as the Ni2+ source. The results show that a better bonding and uniform coating layer were obtained for Ni-B coatings with the Ni2+ source of NiCl2.6H2O as compared to NiSO4.6H2O. With the progress of the time, both particle surfaces are completely covered by a continuous and thin nickel boron layer. The surface morphology of the coatings that were analysed using scanning electron microscopy (SEM) show that SiC and B4C particles both distributed and different thickness of Ni-B nanolayers have been successfully coated onto the particles. The particles were mounted into a polimeric resin and polished in order to observe the thickness and the continuity of the coating layer. The composition of the coating layers were also evaluated by EDS analyses. The SEM morphologies and the EDS results of the coatings at different reaction times were adopted for detailed discussion of the Ni-B electroless plating mechanism.Keywords: boron carbide, electroless coating, nickel boron deposition, silicon carbide
Procedia PDF Downloads 3485947 Exploring the Application of Additive Manufacturing in the Production of Aerogels for the Purpose of Creating Environmentally Friendly Agricultural Formulations with Controlled Release Properties
Authors: Pram Abhayawardhana, Ali Reza Nazmi, Hossein Najaf Zadeh
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This study examines the use of additive manufacturing (AM) to develop sustainable and intelligent agricultural formulations that can gradually release fertilisers. AM offers the ability to design customised formulations with precise geometries and controlled release properties while taking into account their mechanical, chemical, and environmental properties. The study specifically investigates the use of an aerogel matrix mixed with a potential fertiliser in agriculture. Highly porous 3D printed aerogel structures were designed to enable the slow release of fertilisers. The performance of the formulated mixture is evaluated against other commonly used materials for slow-release applications. The findings suggest that the 3D printed gel made has great potential for slow-release fertilisers, providing an environmentally friendly solution for agricultural practices. The combination of AM technology and sustainable materials can play a vital role in mitigating the negative environmental impact of traditional fertilisers, as well as improving the efficiency and sustainability of agricultural production.Keywords: 3D printing, hydrogel, aerogel, fertiliser, agriculture
Procedia PDF Downloads 945946 Phase Composition Analysis of Ternary Alloy Materials for Gas Turbine Applications
Authors: Mayandi Ramanathan
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Gas turbine blades see the most aggressive thermal stress conditions within the engine, due to high Turbine Entry Temperatures in the range of 1500 to 1600°C. The blades rotate at very high rotation rates and remove a significant amount of thermal power from the gas stream. At high temperatures, the major component failure mechanism is a creep. During its service over time under high thermal 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 and gas turbine components. The proposed advanced Ti alloy material needs a process that provides a strategic orientation of metallic ordering, uniformity in composition and high metallic strength. The chemical composition of the proposed Ti alloy material (25% Ta/(Al+Ta) ratio), unlike Ti-47Al-2Cr-2Nb, has less excess Al that could limit the service life of turbine blades. Properties and performance of Ti-47Al-2Cr-2Nb and Ti-6Al-4V materials will be compared with that of the proposed Ti alloy material to generalize the performance metrics of various gas turbine components. This paper will involve the summary of the effects of additive manufacturing and heat treatment process conditions on the changes in the phase composition, grain structure, lattice structure of the material, tensile strength, creep strain rate, thermal expansion coefficient and fracture toughness at different temperatures. Based on these results, additive manufacturing and heat treatment process conditions will be optimized to fabricate turbine blade with Ti-43Al matrix alloyed with an optimized amount of refractory Ta metal. Improvement in service temperature of the turbine blades and corrosion resistance dependence on the coercivity of the alloy material will be reported. A correlation of phase composition and creep strain rate will also be discussed.Keywords: high temperature materials, aerospace, specific strength, creep strain, phase composition
Procedia PDF Downloads 1165945 Shock-Induced Densification in Glass Materials: A Non-Equilibrium Molecular Dynamics Study
Authors: Richard Renou, Laurent Soulard
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Lasers are widely used in glass material processing, from waveguide fabrication to channel drilling. The gradual damage of glass optics under UV lasers is also an important issue to be addressed. Glass materials (including metallic glasses) can undergo a permanent densification under laser-induced shock loading. Despite increased interest on interactions between laser and glass materials, little is known about the structural mechanisms involved under shock loading. For example, the densification process in silica glasses occurs between 8 GPa and 30 GPa. Above 30 GPa, the glass material returns to the original density after relaxation. Investigating these unusual mechanisms in silica glass will provide an overall better understanding in glass behaviour. Non-Equilibrium Molecular Dynamics simulations (NEMD) were carried out in order to gain insight on the silica glass microscopic structure under shock loading. The shock was generated by the use of a piston impacting the glass material at high velocity (from 100m/s up to 2km/s). Periodic boundary conditions were used in the directions perpendicular to the shock propagation to model an infinite system. One-dimensional shock propagations were therefore studied. Simulations were performed with the STAMP code developed by the CEA. A very specific structure is observed in a silica glass. Oxygen atoms around Silicon atoms are organized in tetrahedrons. Those tetrahedrons are linked and tend to form rings inside the structure. A significant amount of empty cavities is also observed in glass materials. In order to understand how a shock loading is impacting the overall structure, the tetrahedrons, the rings and the cavities were thoroughly analysed. An elastic behaviour was observed when the shock pressure is below 8 GPa. This is consistent with the Hugoniot Elastic Limit (HEL) of 8.8 GPa estimated experimentally for silica glasses. Behind the shock front, the ring structure and the cavity distribution are impacted. The ring volume is smaller, and most cavities disappear with increasing shock pressure. However, the tetrahedral structure is not affected. The elasticity of the glass structure is therefore related to a ring shrinking and a cavity closing. Above the HEL, the shock pressure is high enough to impact the tetrahedral structure. An increasing number of hexahedrons and octahedrons are formed with the pressure. The large rings break to form smaller ones. The cavities are however not impacted as most cavities are already closed under an elastic shock. After the material relaxation, a significant amount of hexahedrons and octahedrons is still observed, and most of the cavities remain closed. The overall ring distribution after relaxation is similar to the equilibrium distribution. The densification process is therefore related to two structural mechanisms: a change in the coordination of silicon atoms and a cavity closing. To sum up, non-equilibrium molecular dynamics were carried out to investigate silica behaviour under shock loading. Analysing the structure lead to interesting conclusions upon the elastic and the densification mechanisms in glass materials. This work will be completed with a detailed study of the mechanism occurring above 30 GPa, where no sign of densification is observed after the material relaxation.Keywords: densification, molecular dynamics simulations, shock loading, silica glass
Procedia PDF Downloads 2225944 Hydrogen Storage Optimisation: Development of Advanced Tools for Improved Permeability Modelling in Materials
Authors: Sirine Sayed, Mahrez Ait Mohammed, Mourad Nachtane, Abdelwahed Barkaoui, Khalid Bouziane, Mostapha Tarfaoui
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This study addresses a critical challenge in transitioning to a hydrogen-based economy by introducing and validating a one-dimensional (1D) tool for modelling hydrogen permeability through hybrid materials, focusing on tank applications. The model developed integrates rigorous experimental validation, published data, and advanced computational modelling using the PanDiffusion framework, significantly enhancing its validity and applicability. By elucidating complex interactions between material properties, storage system configurations, and operational parameters, the tool demonstrates its capability to optimize design and operational parameters in real-world scenarios, as illustrated through a case study of hydrogen leakage. This comprehensive approach to assessing hydrogen permeability contributes significantly to overcoming key barriers in hydrogen infrastructure development, potentially accelerating the widespread adoption of hydrogen technology across various industrial sectors and marking a crucial step towards a more sustainable energy future.Keywords: hydrogen storage, composite tank, permeability modelling, PanDiffusion, energy carrier, transportation technology
Procedia PDF Downloads 155943 Multichannel Analysis of the Surface Waves of Earth Materials in Some Parts of Lagos State, Nigeria
Authors: R. B. Adegbola, K. F. Oyedele, L. Adeoti
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We present a method that utilizes Multi-channel Analysis of Surface Waves, which was used to measure shear wave velocities with a view to establishing the probable causes of road failure, subsidence and weakening of structures in some Local Government Area, Lagos, Nigeria. Multi channel Analysis of Surface waves (MASW) data were acquired using 24-channel seismograph. The acquired data were processed and transformed into two-dimensional (2-D) structure reflective of depth and surface wave velocity distribution within a depth of 0–15m beneath the surface using SURFSEIS software. The shear wave velocity data were compared with other geophysical/borehole data that were acquired along the same profile. The comparison and correlation illustrates the accuracy and consistency of MASW derived-shear wave velocity profiles. Rigidity modulus and N-value were also generated. The study showed that the low velocity/very low velocity are reflective of organic clay/peat materials and thus likely responsible for the failed, subsidence/weakening of structures within the study areas.Keywords: seismograph, road failure, rigidity modulus, N-value, subsidence
Procedia PDF Downloads 3635942 Integration of Acoustic Solutions for Classrooms
Authors: Eyibo Ebengeobong Eddie, Halil Zafer Alibaba
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The neglect of classroom acoustics is dominant in most educational facilities, meanwhile, hearing and listening is the learning process in this kind of facilities. A classroom should therefore be an environment that encourages listening, without an obstacles to understanding what is being taught. Although different studies have shown teachers to complain that noise is the everyday factor that causes stress in classroom, the capacity of individuals to understand speech is further affected by Echoes, Reverberation, and room modes. It is therefore necessary for classrooms to have an ideal acoustics to aid the intelligibility of students in the learning process. The influence of these acoustical parameters on learning and teaching in schools needs to be further researched upon to enhance the teaching and learning capacity of both teacher and student. For this reason, there is a strong need to provide and collect data to analyse and define the suitable quality of classrooms needed for a learning environment. Research has shown that acoustical problems are still experienced in both newer and older schools. However, recently, principle of acoustics has been analysed and room acoustics can now be measured with various technologies and sound systems to improve and solve the problem of acoustics in classrooms. These acoustic solutions, materials, construction methods and integration processes would be discussed in this paper.Keywords: classroom, acoustics, materials, integration, speech intelligibility
Procedia PDF Downloads 4175941 Particleboard Production from Atmospheric Plasma Treated Wheat Straw Particles
Authors: Štěpán Hýsek, Milan Podlena, Miloš Pavelek, Matěj Hodoušek, Martin Böhm, Petra Gajdačová
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Particle boards have being used in the civil engineering as a decking for load bearing and non-load bearing vertical walls and horizontal panels (e. g. floors, ceiling, roofs) in a large scale. When the straw is used as non-wood material for manufacturing of lignocellulosic panels, problems with wax layer on the surface of the material can occur. Higher percentage of silica and wax cause the problems with the adhesion of the adhesive and this is the reason why it is necessary to break the surface layer for the better bonding effect. Surface treatment of the particles cause better mechanical properties, physical properties and the overall better results of the composite material are reached. Plasma application is one possibility how to modify the surface layer. The aim of this research is to modify the surface of straw particles by using cold plasma treatment. Surface properties of lignocellulosic materials were observed before and after cold plasma treatment. Cold plasma does not cause any structural changes deeply in the material. There are only changes in surface layers, which are required. Results proved that the plasma application influenced the properties of surface layers and the properties of composite material.Keywords: composite, lignocellulosic materials, straw, cold plasma, surface treatment
Procedia PDF Downloads 3305940 Effects of Stokes Shift and Purcell Enhancement in Fluorescence Assisted Radiative Cooling
Authors: Xue Ma, Yang Fu, Dangyuan Lei
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Passive daytime radiative cooling is an emerging technology which has attracted worldwide attention in recent years due to its huge potential in cooling buildings without the use of electricity. Various coating materials with different optical properties have been developed to improve the daytime radiative cooling performance. However, commercial cooling coatings comprising functional fillers with optical bandgaps within the solar spectral range suffers from severe intrinsic absorption, limiting their cooling performance. Fortunately, it has recently been demonstrated that introducing fluorescent materials into polymeric coatings can covert the absorbed sunlight to fluorescent emissions and hence increase the effective solar reflectance and cooling performance. In this paper, we experimentally investigate the key factors for fluorescence-assisted radiative cooling with TiO2-based white coatings. The surrounding TiO2 nanoparticles, which enable spatial and temporal light confinement through multiple Mie scattering, lead to Purcell enhancement of phosphors in the coating. Photoluminescence lifetimes of two phosphors (BaMgAl10O17:Eu2+ and (Sr, Ba)SiO4:Eu2+) exhibit significant reduction of ~61% and ~23%, indicating Purcell factors of 2.6 and 1.3, respectively. Moreover, smaller Stokes shifts of the phosphors are preferred to further diminish solar absorption. Field test of fluorescent cooling coatings demonstrate an improvement of ~4% solar reflectance for the BaMgAl10O17:Eu2+-based fluorescent cooling coating. However, to maximize solar reflectance, a white appearance is introduced based on multiple Mie scattering by the broad size distribution of fillers, which is visually pressurized and aesthetically bored. Besides, most colored pigments absorb visible light significantly and convert it to non-radiative thermal energy, offsetting the cooling effect. Therefore, current colored cooling coatings are facing the compromise between color saturation and cooling effect. To solve this problem, we introduced colored fluorescent materials into white coating based on SiO2 microspheres as a top layer, covering a white cooling coating based on TiO2. Compared with the colored pigments, fluorescent materials could re-emit the absorbed light, reducing the solar absorption introduced by coloration. Our work investigated the scattering properties of SiO2 dielectric spheres with different diameters and detailly discussed their impact on the PL properties of phosphors, paving the way for colored fluorescent-assisted cooling coting to application and industrialization.Keywords: solar reflection, infrared emissivity, mie scattering, photoluminescent emission, radiative cooling
Procedia PDF Downloads 865939 Attitudes of Grade School and Kindergarten Teachers towards the Implementation of Mother-Tongue Based Language in Education
Authors: Irene Guatno Toribio
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This study purported to determine and describe the attitudes of grade school and kindergarten teachers in District I, Division of City Schools in Parañaque towards the implementation of mother tongue-based multilingual education instruction. Employing a descriptive method of research, this study specifically looked into the attitudes of the participants towards the implementation of mother tongue-based language in terms of curricular content, teaching methods, instructional materials used, and administrative support. A total of nineteen teachers, eight (8) of which were kindergarten teachers and eleven (11) were grade one teachers. A self-made survey questionnaire was developed by the researcher and validated by the experts. This constituted the main instrument in gathering the needed data and information relative to the major concern of the study, which were analyzed and interpreted through the use of descriptive statistics. The findings of this study revealed that grade one and kindergarten teachers have a positive attitude towards the integration and inclusion of mother-tongue based language in the curriculum. In terms of suggested teaching methods, the kindergarten teacher’s attitude towards the use of storytelling and interactive activities is highly positive, while two groups of teachers both recommend the use of big books and painting kit as an instructional materials. While the kindergarten teachers would tend to cling on the use of big books, this was not the case for grade school teachers who would rather go for the use of painting kit which was not favored by the kindergarten teachers. Finally, in terms of administrative support, the grade one teacher is very satisfied when it comes to the support of their school administrator. While the kindergarten teachers has developed the feeling that the school administration has failed to give them enough materials in their activities, the grade school teachers, on the other hand, have developed the feeling that the same school administration might have failed to strictly evaluate the kindergarten teachers. Based on the findings of this study, it is recommended that the school administration must provide seminars to teachers to better equip them with the needed knowledge and competencies in implementing the Mother-Tongue Based, Multilingual Education (MTB-MLE).Keywords: attitude, grade school, kindergarten teachers, mother-tongue
Procedia PDF Downloads 3215938 Semiconducting Nanostructures Based Organic Pollutant Degradation Using Natural Sunlight for Water Remediation
Authors: Ankur Gupta, Jayant Raj Saurav, Shantanu Bhattacharya
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In this work we report an effective water filtration system based on the photo catalytic performance of semiconducting dense nano-brushes under natural sunlight. During thin-film photocatalysis usually performed by a deposited layer of photocatalyst, a stagnant boundary layer is created near the catalyst which adversely affects the rate of adsorption because of diffusional restrictions. One strategy that may be used is to disrupt this laminar boundary layer by creating a super dense nanostructure near the surface of the catalyst. Further it is adequate to fabricate a structured filter element for a through pass of the water with as grown nanostructures coming out of the surface of such an element. So, the dye remediation is performed through solar means. This remediation was initially limited to lower efficiency because of diffusional restrictions but has now turned around as a fast process owing to the development of the filter materials with standing out dense nanostructures. The effect of increased surface area due to microholes on fraction adsorbed is also investigated and found that there is an optimum value of hole diameter for maximum adsorption.Keywords: nano materials, photocatalysis, waste water treatment, water remediation
Procedia PDF Downloads 3395937 Teaching Intercultural Literary Genres in Pakistani Universities: The Undergraduate Students’ Perspective on the Poetry of Rumi and Blake
Authors: Afshan Liaquat
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Pakistan is a multicultural country, and people are divided across political and religious values. The major objective of this study is to investigate the pedagogical relevance of the poetry of Rumi and Blake for culturally diverse undergraduate classes in Pakistani universities in Lahore. The study was based on a survey research design. A closed-ended questionnaire was developed for data collection from 100 students purposively selected from two universities in Lahore. The findings of the study indicate that intercultural poetry with the theme of Love, written by poets like Rumi and Blake, needs to be taught at the undergraduate level. The study has implications for students, teachers, and genre-based syllabus designers associated with teaching English Literature in Pakistani universities.Keywords: intercultural literature, globalization, spiritual love, teaching of cross-cultural literature
Procedia PDF Downloads 515936 Kosovar Teachers' Understanding of Literacy Education
Authors: Anemonë Zeneli
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Classrooms composed of students with varied linguistic repertoires, in combination with new technologies, have shifted what it means to be literate and how literacy is taught. At the same time, definitions of literacy matter greatly as they shape literacy education curricula, national literacy agendas, and pedagogical choices. Grounded in the theoretical frameworks of New Literacy Studies and Critical Literacy, this research investigates how Kosovar teachers make sense of literacy. The study employed a qualitative research design involving classroom observations, teacher interviews, and document analysis in a public school in the capital city of Kosovo, Prishtina. Data was collected from 5 Albanian language teachers. Classroom observations allowed for the documentation of how teachers applied literacy and language pedagogies to their teaching. Teacher interviews provided insights into teachers’ understanding of literacy education and the rationale behind their chosen pedagogies. Document analysis, more specifically, lesson plan analysis, further explained teachers’ content and instructional choices. The findings suggest that teachers understand literacy as standardized language instruction. They spoke to the challenges of language instruction in standardized Albanian in a Gheg (dialect) dominant society. Teachers’ narratives described the tension that students face in navigating standardized language expectations while being unable to use their home (Gheg) literacies. Teachers’ narratives were imbued with moral contestation as they explained the lack of an infrastructure that allows students to apply their home language and literacies in the classroom. Furthermore, teachers expressed their insistence on teaching “the words of the book.” While this viewpoint on language and literacy is generally aligned with normative and colonial expectations on language, at the same time, it reveals teachers’ intention to ‘equip’ their students with skills and practices that they will be tested on. Some of the teachers also articulated the need for a pedagogy of correction that the work of upholding the standardized language variation necessitates. Here, teachers also utilized discourses of neoliberalism when discussing students’ English repertoire and its value in “opening doors” and advancement opportunities in life while further framing students’ home literacies, the Gheg dialect, in a deficit manner. If educators and policymakers are to make informed decisions about efforts to improve schools, it is important to improve our knowledge of what informs teachers’ pedagogical choices in teaching literacy. This study contributes to and expands the current knowledge base on teachers’ understanding of literacy education and their role in shaping literacy education. As schools continue to navigate (growing) diverse forms of literacy, this study highlights the importance of equipping educators with the knowledge and tools to apply literacy pedagogies that reflect the ever-shifting definitions of literacy education.Keywords: literacy education, standardized language, critical narrative analysis, literacy teaching
Procedia PDF Downloads 185935 Application of Rapid Prototyping to Create Additive Prototype Using Computer System
Authors: Meftah O. Bashir, Fatma A. Karkory
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Rapid prototyping is a new group of manufacturing processes, which allows fabrication of physical of any complexity using a layer by layer deposition technique directly from a computer system. The rapid prototyping process greatly reduces the time and cost necessary to bring a new product to market. The prototypes made by these systems are used in a range of industrial application including design evaluation, verification, testing, and as patterns for casting processes. These processes employ a variety of materials and mechanisms to build up the layers to build the part. The present work was to build a FDM prototyping machine that could control the X-Y motion and material deposition, to generate two-dimensional and three-dimensional complex shapes. This study focused on the deposition of wax material. This work was to find out the properties of the wax materials used in this work in order to enable better control of the FDM process. This study will look at the integration of a computer controlled electro-mechanical system with the traditional FDM additive prototyping process. The characteristics of the wax were also analysed in order to optimize the model production process. These included wax phase change temperature, wax viscosity and wax droplet shape during processing.Keywords: rapid prototyping, wax, manufacturing processes, shape
Procedia PDF Downloads 4645934 Acoustic Absorption of Hemp Walls with Ground Granulated Blast Slag
Authors: Oliver Kinnane, Aidan Reilly, John Grimes, Sara Pavia, Rosanne Walker
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Unwanted sound reflection can create acoustic discomfort and lead to problems of speech comprehensibility. Contemporary building techniques enable highly finished internal walls resulting in sound reflective surfaces. In contrast, sustainable construction materials using natural and vegetal materials, are often more porous and absorptive. Hemp shiv is used as an aggregate and when mixed with lime binder creates a low-embodied-energy concrete. Cement replacements such as ground granulated blast slag (GGBS), a byproduct of other industrial processes, are viewed as more sustainable alternatives to high-embodied-energy cement. Hemp concretes exhibit good hygrothermal performance. This has focused much research attention on them as natural and sustainable low-energy alternatives to standard concretes. A less explored benefit is the acoustic absorption capability of hemp-based concretes. This work investigates hemp-lime-GGBS concrete specifically, and shows that it exhibits high levels of sound absorption.Keywords: hemp, hempcrete, acoustic absorption, GGBS
Procedia PDF Downloads 4025933 Study of the Behavior of Copper Immersed in Sea Water of the Bay of Large Agadir by Electrochemical Methods
Authors: Aicha Chaouay, Lahsen Bazzi, Mustapha Hilali
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Seawater has chemical and biological characteristics making it particularly aggressive in relation to the corrosion of many materials including copper and steels low or moderate allies. Note that these materials are widely used in the manufacture of port infrastructure in the marine environment. These structures are exposed to two types of corrosion including: general corrosion and localized corrosion caused by the presence of sulfite-reducing micro-organisms. This work contributes to the study of the problematic related to bacterial contamination of the marine environment of large Agadir and evaluating the impact of this pollution on the corrosion resistance of copper. For the realization of this work, we conducted monthly periodic draws between (October 2012 February 2013) of seawater from the Anza area of the Bay of Agadir. Thus, after each sampling, a study of the electro chemical corrosion behavior of copper was carried out. Electro chemical corrosion parameters such as the corrosion potential, the corrosion current density, the charge transfer resistance and the double layer capacity were evaluated. The electro chemical techniques used in this work are: the route potentiodynamic polarization curves and electro chemical impedance.Keywords: Bay of Agadir, microbial contamination, seawater (Morocco), corrosion, copper
Procedia PDF Downloads 5085932 Immersive Environment as an Occupant-Centric Tool for Architecture Criticism and Architectural Education
Authors: Golnoush Rostami, Farzam Kharvari
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In recent years, developments in the field of architectural education have resulted in a shift from conventional teaching methods to alternative state-of-the-art approaches in teaching methods and strategies. Criticism in architecture has been a key player both in the profession and education, but it has been mostly offered by renowned individuals. Hence, not only students or other professionals but also critics themselves may not have the option to experience buildings and rely on available 2D materials, such as images and plans, that may not result in a holistic understanding and evaluation of buildings. On the other hand, immersive environments provide students and professionals the opportunity to experience buildings virtually and reflect their evaluation by experiencing rather than judging based on 2D materials. Therefore, the aim of this study is to compare the effect of experiencing buildings in immersive environments and 2D drawings, including images and plans, on architecture criticism and architectural education. As a result, three buildings that have parametric brick facades were studied through 2D materials and in Unreal Engine v. 24 as an immersive environment among 22 architecture students that were selected using convenient sampling and were divided into two equal groups using simple random sampling. This study used mixed methods, including quantitative and qualitative methods; the quantitative section was carried out by a questionnaire, and deep interviews were used for the qualitative section. A questionnaire was developed for measuring three constructs, including privacy regulation based on Altman’s theory, the sufficiency of illuminance levels in the building, and the visual status of the view (visually appealing views based on obstructions that may have been caused by facades). Furthermore, participants had the opportunity to reflect their understanding and evaluation of the buildings in individual interviews. Accordingly, the collected data from the questionnaires were analyzed using independent t-test and descriptive analyses in IBM SPSS Statistics v. 26, and interviews were analyzed using the content analysis method. The results of the interviews showed that the participants who experienced the buildings in the immersive environment were able to have a thorough and more precise evaluation of the buildings in comparison to those who studied them through 2D materials. Moreover, the analyses of the respondents’ questionnaires revealed that there were statistically significant differences between measured constructs among the two groups. The outcome of this study suggests that integrating immersive environments into the profession and architectural education as an effective and efficient tool for architecture criticism is vital since these environments allow users to have a holistic evaluation of buildings for vigorous and sound criticism.Keywords: immersive environments, architecture criticism, architectural education, occupant-centric evaluation, pre-occupancy evaluation
Procedia PDF Downloads 1345931 Integration of Social Media in Teaching and Learning Activities: A Case Study
Authors: A. Nagaletchimee Annamalai
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The study investigated on how a small group of pre-service teachers and lecturers used social media to interact and collaborate to complete their tasks. The study is a qualitative case study that explored the lecturers’ reflections and pre-service teachers’ interviews. The lecturers were given the option to choose Facebook or any other social media as their teaching and learning platforms. However, certain guidelines based on were given to lecturers to conduct their teaching and learning activities. The findings revealed that although Facebook was a popular social networking site, it was not a preferred educational platform. Lecturers preferred to use WhatsApp, Canvas, and email. The focus group interview found positive and negative experiences of the pre-service teachers. The study suggested several pedagogical implications and importantly highlighted the need for changes in curriculum to ensure lecturers leverage the potential of technology in education.Keywords: social media, interactions, collaboration, online learning environment
Procedia PDF Downloads 1825930 Insight into the Electrocatalytic Activities of Nitrogen-Doped Graphyne and Graphdiyne Families: A First-Principles Study
Authors: Bikram K. Das, Kalyan K. Chattopadhyay
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The advent of 2-D materials in the last decade has induced a fresh spur of growth in fuel cell technology as these materials have some highly promising traits that can be exploited to felicitate Oxygen Reduction Reaction (ORR) in an efficient way. Among the various 2-D carbon materials, graphyne (Gy) and graphdiyne (Gdy)1 with their intrinsic non-uniform charge distribution holds promises in this purpose and it is expected2 that substitutional Nitrogen (N) doping could further enhance their efficiency. In this regard, dispersive force corrected density functional theory is used to map the oxygen reduction reaction (ORR) kinetics of five different kinds of N doped graphyne and graphdiyne systems (namely αGy, βGy, γGy, RGy and 6,6,12Gy and Gdy) in alkaline medium. The best doping site for each of the Gy/ Gdy system is determined comparing the formation energies of the possible doping configurations. Similarly, the best di-oxygen (O₂) adsorption sites for the doped systems are identified by comparing the adsorption energies. O₂ adsorption on all N doped Gy/ Gdy systems is found to be energetically favorable. ORR on a catalyst surface may occur either via the Eley-Rideal (ER) or the Langmuir–Hinschelwood (LH) pathway. Systematic studies performed on the considered systems reveal that all of them favor the ER pathway. Further, depending on the nature of di-oxygen adsorption ORR can follow either associative or dissociative mechanism; the possibility of occurrence of both the mechanisms is tested thoroughly for each N doped Gy/ Gdy. For the ORR process, all the Gy/Gdy systems are observed to prefer the efficient four-electron pathway but the expected monotonically exothermic reaction pathway is found only for N doped 6,6,12Gy and RGy following the associative pathway and for N doped βGy, γGy and Gdy following the dissociative pathway. Further computation performed for these systems reveals that for N doped 6,6,12Gy, RGy, βGy, γGy and Gdy the overpotentials are 1.08 V, 0.94 V, 1.17 V, 1.21 V and 1.04 V respectively depicting N doped RGy is the most promising material, to carry out ORR in alkaline medium, among the considered ones. The stability of the ORR intermediate states with the variation of pH and electrode potentials is further explored with Pourbiax diagrams and the activities of these systems in the alkaline medium are compared with the prior reported B/N doped identical systems for ORR in an acidic medium in terms of a common descriptor.Keywords: graphdiyne, graphyne, nitrogen-doped, ORR
Procedia PDF Downloads 1285929 Continuous Professional Development of Teachers: Implementation Mechanisms in the Republic of Kazakhstan Based on the Professional Standard 'Teacher'
Authors: Yelena Agranovich, Larissa Ageyeva, Aigul Syzdykbayeva, Violetta Tyan
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The modernization of the education system in the Republic of Kazakhstan is aimed at improving the quality of teacher training and enhancing key competencies among teachers. The current professional standard ‘Teacher’ defines the general characteristics of teachers’ activities, key competencies, and criteria according to relevant qualification categories structured on the principle of progression, thereby enabling Continuous Professional Development (CPD). The essence of CPD lies in the constant integration of new knowledge and skills that help teachers adapt to changes in the education system, in technologies, and teaching methods. This developmental process enables teachers to stay updated on recent scientific achievements, innovations, and modern pedagogical practices. Continuous learning helps teachers remain flexible and open to new developments, creating conditions for improving educational quality and fostering students' personal growth. This study aims to address the following objectives: analysis of international CPD practices, identification of conceptual foundations, and investigation of CPD implementation mechanisms in Kazakhstan. The core principles of CPD are identified as longitudinality, systematicity, and fragmentation. CPD implementation is based on various theoretical approaches: axiological, systemic, competency-based, activity-based, and learner-centered. The study analyzes leading models of teacher CPD, with a target sample that includes countries such as Australia, Japan, South Korea, England, Singapore, Sweden, Finland, and Kazakhstan. The research methods include analysis (comparative, historical, content analysis, systematic), case studies of CPD models, and synthesis and systematization of scientific data. As research results, the mechanisms for CPD implementation in Kazakhstan will be identified, along with further perspectives on transforming resources within the teacher professional development system. In comparing CPD models from various countries, it is noted that teacher CPD in the Republic of Kazakhstan: (1) is implemented through educational programs, professional development courses, teacher certification, professional networks, in-school professional development, self-education, and self-assessment; (2) includes the development of pedagogical values and competencies (tolerance, inclusivity, communication, critical thinking, creativity, reflection, etc.); (3) is carried out based on traditional forms (professional development courses, retraining) and informal forms (self-learning, self-development, experience sharing and exchange). Further research will focus on creating a digital ecosystem for teacher CPD, based on an educational platform that facilitates individualized professional development pathways for teachers (competency diagnostics, course selection, and a methodological system of course and post-course support for teachers).Keywords: continuous professional development, CPD models, professional development, professional upgrading, teacher, teacher training
Procedia PDF Downloads 125928 A Novel Bio-ceramic Using Hyperthermia for Bone Cancer Therapy, Ferro-substituted Silicate Calcium Materials
Authors: hassan gheisari
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Ferro silicate calcium nano particles are prepared through the sol-gel method using polyvinyl alcohol (PVA) as a chelating agent. The powder, as prepared, is annealed at three different temperatures (900 ºC, 1000 ºC, and 1100 ºC) for 3 h. The XRD patterns of the samples indicate broad peaks, and the full width at half maximum decreased with increasing annealing temperature. FTIR spectra of the samples confirm the presence of metal - oxygen complexes within the structure. The average particle size obtained from PSA curve demonstrates ultrafine particles. SEM micrographs indicate the particles synthesized have spherical morphology. The saturation magnetization (Ms) and remnant magnetization (Mr) of the samples show dependence on particle size and crystallinity of the samples. The highest saturation magnetization is achieved for the sample annealed at 1100 ºC having maximum average particle size. The high saturation magnetization of the samples suggests the present method is suitable for obtaining nano particles magnetic ferro bioceramic, which is desirable for practical applications such as hyperthermia bone cancer therapy.Keywords: hyperthermia, bone cancer, bio ceramic; magnetic materials; sol– gel, silicate calcium
Procedia PDF Downloads 735927 Ferro-Substituted Silicate Calcium Materials, a Novel Bio-Ceramic Using Hyperthermia for Bone Cancer Therapy
Authors: Hassan Gheisari
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Ferro silicate calcium nano particles are prepared through the sol-gel method using polyvinyl alcohol (PVA) as a chelating agent. The powder as prepared is annealed at three different temperatures (900 ºC, 1000 ºC and 1100 ºC) for 3 h. The XRD patterns of the samples indicate broad peaks and the full width at half maximum decreased with increasing annealing temperature. FTIR spectra of the samples confirm the presence of metal - oxygen complexes within the structure. The average particle size obtained from PSA curve demonstrates ultrafine particles. SEM micrographs indicate the particles synthesized have spherical morphology. The saturation magnetization (Ms) and remnant magnetization (Mr) of the samples show dependence on particle size and crystallinity of the samples. The highest saturation magnetization is achieved for the sample annealed at 1100 ºC having maximum average particle size. The high saturation magnetization of the samples suggests the present method is suitable for obtaining nano particles magnetic ferro bioceramic which is desirable for practical applications such as hyperthermia bone cancer therapy.Keywords: hyperthermia, bone cancer, bio ceramic, magnetic materials, sol– gel, silicate calcium
Procedia PDF Downloads 3085926 Study of Heat Exchangers in Small Modular Reactors
Authors: Harish Aryal, Roger Hague, Daniel Sotelo, Felipe Astete Salinas
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This paper presents a comparative study of different coolants, materials, and temperatures that can affect the effectiveness of heat exchangers that are used in small modular reactors. The corrugated plate heat exchangers were chosen out of different plate options for testing purposes because of their ease of access and better performance than other existing heat exchangers in recent years. SolidWorks enables us to see various results between water coolants and helium coolants acting upon different types of conducting metals, which were selected from different fluids that ultimately satisfied accessibility requirements and were compatible with the software. Though not every element, material, fluid, or method was used in the testing phase, their purpose is to help further research that is to come since the innovation of nuclear power is the future. The tests that were performed are to help better understand the constant necessities that are seen in heat exchangers and through every adjustment see what the breaking points or improvements in the machine are. Depending on consumers and researchers, the results may give further feedback as to show why different types of materials and fluids would be preferred and why it is necessary to keep failures to improve future research.Keywords: heat exchangers, Solidworks, coolants, small modular reactors, nuclear power, nanofluids, Nusselt number, friction factor, Reynolds number
Procedia PDF Downloads 735925 An Analytical Study of FRP-Concrete Bridge Superstructures
Authors: Wael I. Alnahhal
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It is a major challenge to build a bridge superstructure that has long-term durability and low maintenance requirements. A solution to this challenge may be to use new materials or to implement new structural systems. Fiber reinforced polymer (FRP) composites have continued to play an important role in solving some of persistent problems in infrastructure applications because of its high specific strength, light weight, and durability. In this study, the concept of the hybrid FRP-concrete structural systems is applied to a bridge superstructure. The hybrid FRP-concrete bridge superstructure is intended to have durable, structurally sound, and cost effective hybrid system that will take full advantage of the inherent properties of both FRP materials and concrete. In this study, two hybrid FRP-concrete bridge systems were investigated. The first system consists of trapezoidal cell units forming a bridge superstructure. The second one is formed by arch cells. The two systems rely on using cellular components to form the core of the bridge superstructure, and an outer shell to warp around those cells to form the integral unit of the bridge. Both systems were investigated analytically by using finite element (FE) analysis. From the rigorous FE studies, it was concluded that first system is more efficient than the second.Keywords: bridge superstructure, hybrid system, fiber reinforced polymer, finite element analysis
Procedia PDF Downloads 334