Search results for: wind power generation facilities

Authors: Sari Elkahina, Zergoug Mourad, Benachenhou Kamel

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The main purpose of this paper is to perform a computations comparison of stress intensity factor 'SIF' evaluation in case of cracked thin plate with Aluminum alloy 7075-T6 and 2024-T3 used in aeronautics structure under uniaxial loading. This evaluation is based on finite element method with a virtual power principle through two techniques: the extrapolation and G−θ. The first one consists to extrapolate the nodal displacements near the cracked tip using a refined triangular mesh with T3 and T6 special elements, while the second, consists of determining the energy release rate G through G−θ method by potential energy derivation which corresponds numerically to the elastic solution post-processing of a cracked solid by a contour integration computation via Gauss points. The SIF obtained results from extrapolation and G−θ methods will be compared to an analytical solution in a particular case. To illustrate the influence of the meshing kind and the size of integration contour position simulations are presented and analyzed.

Keywords: crack tip, SIF, finite element method, concentration technique, displacement extrapolation, aluminum alloy 7075-T6 and 2024-T3, energy release rate G, G-θ method, Gauss point numerical integration

Procedia PDF Downloads 337

Authors: Sadiah Baharom, Che Nidzam Che Ahmad, Saipol Barin Ramli, Asmayati Yahaya, Sopia Md Yassin

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The early childhood care and education (ECCE) in Malaysia aspire to develop children who are intellectually, emotionally, physically and spiritually balanced. This aspiration can only materialise if the early childhood program developed comprehensive and is of high quality comparable to international standards. As such, there is a pressing need to assess the quality of the program in an all-encompassing manner. The overall research project aims at developing a comprehensive and integrated model of high-quality Malaysian ECCE. One of the major objectives of this project is to assess and evaluate the scope and quality of the existing ECCE programs in Malaysia. To this end, a specific aspect of this objective is to develop and validate an instrument to assess and evaluate the ECCE curriculum of the country. Thus this paper describes the development and validation of an instrument to explore the quality of early childhood care and education curriculum currently implemented in the country’s ECCE centres. The generation of the constructs and items were based on a set of criteria mapped against existing ECCE practice, document analyses, expert interviews and panel discussions. The items went through expert validation and were field tested on 597 ECCE teachers. The data obtained went through an exploratory factor analysis to validate the constructs of the instrument followed by reliability studies on internal consistency based on the Cronbach Alpha values. The final set of items for the ECCE curriculum instrument, earmarked for the main study, consists of four constructs namely philosophy and core values, curriculum content, curriculum review and unique features. Each construct consists of between 21 to 3 items with a total of 36 items in all. The reliability coefficients for each construct range from 0.65 to 0.961. These values are within the acceptable limits for a reliable instrument to be used in the main study.

Keywords: early childhood and care education, instrument development, reliability studies, validity studies

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Authors: Nahla Elazab, Mohamed Aboudina, Ghada Ibrahim, Hossam Fahmy, Ahmed Khalil

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This paper presents the developed memristor based demodulators for eight circular Quadrature Amplitude Modulation (QAM) and Binary Frequency Shift Keying (BFSK) operating at relatively high frequency. In our implementations, the experimental-based ‘nonlinear’ dopant drift model is adopted along with the proposed circuits providing incorporation of all known non-idealities of practically realized memristor and gaining high operation frequency. The suggested designs leverage the distinctive characteristics of the memristor device, definitely, its changeable average memristance versus the frequency, phase and amplitude of the periodic excitation input. The proposed demodulators feature small integration area, low power consumption, and easy implementation. Moreover, the proposed QAM demodulator precludes the requirement for the carrier recovery circuits. In doing so, the designs were validated by transient simulations using the nonlinear dopant drift memristor model. The simulations results show high agreement with the theory presented.

Keywords: BFSK, demodulator, high frequency memristor applications, memristor based analog circuits, nonlinear dopant drift model, QAM

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Authors: Kanik Sharma

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In the year of 2011, the global production of carbon nano-materials (CNMs) was around 3,500 tons, and it is projected to expand at a compound annual growth rate of 30.6%. Expanding markets for applications of CNMs, such as carbon nano-tubes (CNTs) and carbon nano-fibers (CNFs), place ever-increasing demands on lowering their production costs. Current technologies for CNM generation require intensive premium feedstock consumption and employ costly catalysts; they also require input of external energy. Industrial-scale CNM production is conventionally achieved through chemical vapor deposition (CVD) methods which consume a variety of expensive premium chemical feedstocks such as ethylene, carbon monoxide (CO) and hydrogen (H2); or by flame synthesis techniques, which also consume premium feedstock fuels. Additionally, CVD methods are energy-intensive. Renewable and replenishable feedstocks, such as those found in municipal, industrial, agricultural recycling streams have a more judicious reason for usage, in the light of current emerging needs for sustainability. Agricultural sugarcane bagasse and corn residues, scrap tire chips as well as post-consumer polyethylene (PE) and polyethylene terephthalate (PET) bottle shreddings when either thermally treated by sole pyrolysis or by sequential pyrolysis and partial oxidation result in the formation of gaseous carbon-bearing effluents which when channeled into a heated reactor, produce CNMs, including carbon nano-tubes, catalytically synthesized therein on stainless steel meshes. The structure of the nano-material synthesized depends on the type of feedstock available for pyrolysis, and can be determined by analysing the feedstock. These feedstocks could supersede the use of costly and often toxic or highly-flammable chemicals such as hydrocarbon gases, carbon monoxide and hydrogen, which are commonly used as feedstocks in current nano-manufacturing process for CNMs.

Keywords: nanomaterials, waste plastics, sugarcane bagasse, pyrolysis

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Authors: Gideon Nyuimbe Gasu

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Sub Saharan Africa is at a critical point, experiencing rapid population growth, particularly in urban areas and young growing force. At the same time, the growing risk of catastrophic global climate change threatens to weaken food production system, increase intensity and frequency of drought, flood, and fires and undermine gains on development and poverty reduction. Although the region has the lowest per capital greenhouse gas emission level in the world, it will need to join global efforts to address climate change, including action to avoid significant increases and to encourage a green economy. Thus, there is a need for the concept of 'greening the economy' as was prescribed at Rio Summit of 1992. Renewable energy is one of the criterions to achieve this laudable goal of maintaining a green economy. There is need to address climate change while facilitating continued economic growth and social progress as energy today is critical to economic growth. Fossil fuels remain the major contributor of greenhouse gas emission. Thus, cleaner technologies such as carbon capture storage, renewable energy have emerged to be commercially competitive. This paper sets out to examine how to achieve a low carbon economy with minimal emission of carbon dioxide and other greenhouse gases which is one of the outcomes of implementing a green economy. Also, the paper examines the different renewable energy sources such as nuclear, wind, hydro, biofuel, and solar voltaic as a panacea to the looming climate change menace. Finally, the paper assesses the different renewable energy and energy efficiency as a propeller to generating new sources of income and jobs and in turn reduces carbon emission. The research shall engage qualitative, evaluative and comparative methods. The research will employ both primary and secondary sources of information. The primary sources of information shall be drawn from the sub Saharan African region and the global environmental organizations, energy legislation, policies and related industries and the judicial processes. The secondary sources will be made up of some books, journal articles, commentaries, discussions, observations, explanations, expositions, suggestions, prescriptions and other material sourced from the internet on renewable energy as a panacea to climate change. All information obtained from these sources will be subject to content analysis. The research result will show that the entire planet is warming as a result of the activities of mankind which is clear evidence that the current development is fundamentally unsustainable. Equally, the study will reveal that a low carbon development pathway in the sub Saharan African region should be embraced to minimize emission of greenhouse gases such as using renewable energy rather than coal, oil, and gas. The study concludes that until adequate strategies are devised towards the use of renewable energy the region will continue to add and worsen the current climate change menace and other adverse environmental conditions.

Keywords: carbon dioxide, climate change, legislation/law, renewable energy

Procedia PDF Downloads 226

Authors: Yong-Kian Lim, Khan Cheung, Xin Dang, Steven Roberts, Xiaotong Wang, Vengatesen Thiyagarajan

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Unprecedented rate of increased CO₂ level in the ocean and the subsequent changes in carbonate system including decreased pH, known as ocean acidification (OA), is predicted to disrupt not only the calcification process but also several other physiological and developmental processes in a variety of marine organisms, including edible oysters. Nonetheless, not all species are vulnerable to those OA threats, e.g., some species may be able to cope with OA stress using environmentally induced modifications on gene and protein expressions. For example, external environmental stressors, including OA, can influence the addition and removal of methyl groups through epigenetic modification (e.g., DNA methylation) process to turn gene expression “on or off” as part of a rapid adaptive mechanism to cope with OA. In this study, the above hypothesis was tested through testing the effect of OA, using decreased pH 7.4 as a proxy, on the DNA methylation pattern of an endemic and a commercially important estuary oyster species, Crassostrea hongkongensis, at the time of larval habitat selection and metamorphosis. Larval growth rate did not differ between control pH 8.1 and treatment pH 7.4. The metamorphosis rate of the pediveliger larvae was higher at pH 7.4 than those in control pH 8.1; however, over one-third of the larvae raised at pH 7.4 failed to attach to an optimal substrate as defined by biofilm presence. During larval development, a total of 130 genes were differentially methylated across the two treatments. The differential methylation in the larval genes may have partially accounted for the higher metamorphosis success rate under decreased pH 7.4 but with poor substratum selection ability. Differentially methylated loci were concentrated in the exon regions and appear to be associated with cytoskeletal and signal transduction, oxidative stress, metabolic processes, and larval metamorphosis, which implies the high potential of C. hongkongensis larvae to acclimate and adapt through non-genetic ways to OA threats within a single generation.

Keywords: adaptive plasticity, DNA methylation, larval metamorphosis, ocean acidification

Procedia PDF Downloads 139

Authors: Tien Nguyen

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The relationship between mentors and mentees in teaching practicum has received the attention of researchers and been widely investigated. Mentors’ authority and power have captured a large and growing body of the literature in the field of teaching practicum. This article revisits mentor-mentee relationship and shifts the focus to mentees’ agency in planning and delivering lessons, an area which has been under-researched. Drawing on Vygotsky’s Zone of Proximal Development and Harré’s Positioning Theory, this qualitative study examines how mentees responded to mentors’ instructions in practicum. Interviews and classroom observations were conducted with 20 participants including both mentors and mentees across two English language teacher education programs in two different geographical locations in Vietnam. The result indicates that regardless of the similarities and/or differences of the programs, mentees’ agency varied in accordance with their identities in specific contexts. Specifically, mentees follow or resist to mentors’ feedback and instruction in revising their lesson plans and delivery these lessons, depending on their professional identities and institutional conditions. This study contributes to the importance of supporting the agency of mentees in teacher education.

Keywords: mentors, mentees, relationship, agency, professional identity, teacher education

Procedia PDF Downloads 141

Authors: Clifford Otieno Ochieng, Nsenda Lukumwena

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Cities worldwide and most notably those in the global south, including Nairobi City are experiencing accelerated population growth and urban sprawl, accompanied with multiple socioeconomic challenges’ which in turn increase the pressure on already limited infrastructure such as public lighting and on limited financial resources. Based on this premise, through reimaging the value of street lighting infrastructure, the study attempts to highlight the affordance and affordability of streetlights and suggests them as a tool to optimally address limited financial resources that characterize cities in the global south. As a methodology, the paper reviews and analyzes literature available online including Nairobi city budgets; reports from Kenya Power, World Health Organization and United Nations; and articles on enterprise level Internet of Things (IoT) solutions. In conclusion, this study illustrates that streetlights can go well beyond their traditional roles of illuminating cities at night. They can be as suggested in this paper charging stations, communication network terminals and disease prevention nodes.

Keywords: affordance, Nairobi, developing economies, IoT, smart street lights, smart cities

Procedia PDF Downloads 185

Authors: Jo Anne Rey

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Caring for Country (Ngurrain Dharug language) is core to Aboriginal identity, Law/Lore, practice, and resilience within the continent called ‘Australia’. It is the basis of thousands of years of sustainability. However, when Ngurra is a city known as Sydney, due to 235 years of colonial impact, caring for the Country is limited, being controlled by the State and private ownership of the land title. Recent research indicates that localised Indigenous activism is most successful when community members are geographically proximate to the presences and places of connection, caring, and belonging. This article frames these findings through the cadence that proximity provides. This presentation is centred on the proximate agency that is being exercised by Dharug community through three significant sites within the Sydney basin. Those sites include, firstly, Shaw’s Creek Aboriginal Place, at the foot of the Blue Mountains in far western Sydney. Second inclusion is the site of Blacktown Native Institution, that was the part of the authoritarian colonial governance of British Governor Lachlan Macquarie (after who Macquarie University is named), which saw the beginnings of the removal of children from their families and culture to ‘civilize’ them. The third site is that of the so-called Brown’s Waterhole in the State government administered Lane Cove National Park. Each of these sites is being activated through Dharug and, more broadly, Aboriginalways of knowing, doing, and being. These ways involvethe land, water, wind, and star-based ecologies interwoven with traditional transgenerational storying of the presences (Ancestral and spiritual) creating them. Activations include, but are not limited to, the return of cultural fire for reviving plants, soils, animals, and birds. These fire practices have traditionally been at the basis of sustainable, regenerative biodiversity. These practices involve the literacy of reading Ngurra and the seasonal interactions across the ecologies. Together, they both care for the Country and support humanity, and have done so across thousands of years. However, when the cost of real-estate and rental accommodation prevents community members from being able to live on Dharug Ngurra when bureaucratic governance restricts and/or excludes traditional custodial relationships, and when private treaty land title destroys the presences and places while disconnecting people from their Ancestral practices, it becomes clear that caring for Country is only possible when the community can afford to live nearby. Recognising the cadence of proximityas the agency that underpinscaring for Country-in-the-city, sustainable change opportunities don’t have to only focus on regional and remote areas. Urban-based Aboriginal relationality offers an alternative to the unsustainable practices that underpin human-centric disconnection. Weaving Indigenous cadence offers opportunities for sustainable futures even when facing the extremes of climate changing catastrophes.

Keywords: australian aboriginal, biocultural knowledges, climate change, dharug ngurra, sustainability, resilience

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Authors: Kaoutar Ben Azzou, Hanaa Talei

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Human resources is an important department in each organization as it manages the life cycle of employees from recruitment training to retirement or termination of contracts. The recruitment process starts with a job opening, followed by a selection of the best-fit candidates from all applicants. Matching the best profile for a job position requires a manual way of looking at many CVs, which requires hours of work that can sometimes lead to choosing not the best profile. The work presented in this paper aims at reducing the workload of HR personnel by automating the preliminary stages of the candidate screening process, thereby fostering a more streamlined recruitment workflow. This tool introduces an automated system designed to help with the recruitment process by scanning candidates' CVs, extracting pertinent features, and employing machine learning algorithms to decide the most fitting job profile for each candidate. Our work employs natural language processing (NLP) techniques to identify and extract key features from unstructured text extracted from a CV, such as education, work experience, and skills. Subsequently, the system utilizes these features to match candidates with job profiles, leveraging the power of classification algorithms.

Keywords: automated recruitment, candidate screening, machine learning, human resources management

Procedia PDF Downloads 56

Authors: Tali Neta

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Humans’ impact on the environment has been incredibly brutal, with enormous plastic- and other pollutants (e.g., cigarette buds, paper cups, tires) worldwide. On land, litter costs taxpayers a fortune. Most of the litter pollution comes from the land, yet it is one of the greatest hazards to marine environments. Due to spatial and temporal limitations, previous litter data covered very small areas. Currently, smartphones can be used to obtain information on various pollutants (through citizen science), and they can greatly assist in acknowledging and mitigating the environmental impact of litter. Litter app data, such as the Litterati, are available for study through a global map only; these data are not available for download, and it is not clear whether irrelevant hashtags have been eliminated. Instagram and Twitter open-source geospatial data are available for download; however, these are considered inaccurate, computationally challenging, and impossible to quantify. Therefore, the resulting data are of poor quality. Other downloadable geospatial data (e.g., Marine Debris Tracker8 and Clean Swell10) are focused on marine- rather than terrestrial litter. Therefore, accurate terrestrial geospatial documentation of litter distribution is needed to improve environmental awareness. The current research employed citizen science to examine litter distribution in Lethbridge, Alberta, Canada, using the OpenLitterMap (OLM) app. The OLM app is an application used to track litter worldwide, and it can mark litter locations through photo georeferencing, which can be presented through GIS-designed maps. The OLM app provides open-source data that can be downloaded. It also offers information on various litter types and “hot-spots” areas where litter accumulates. In this study, Lethbridge College students collected litter data with the OLM app. The students produced GIS Story Maps (interactive web GIS illustrations) and presented these to school children to improve awareness of litter's impact on environmental health. Preliminary results indicate that towards the Lethbridge Coulees’ (valleys) East edges, the amount of litter significantly increased due to shrubs’ presence, that acted as litter catches. As wind generally travels from west to east in Lethbridge, litter in West-Lethbridge often finds its way down in the east part of the coulees. The students’ documented various litter types, while the majority (75%) included plastic and paper food packaging. The students also found metal wires, broken glass, plastic bottles, golf balls, and tires. Presentations of the Story Maps to school children had a significant impact, as the children voluntarily collected litter during school recess, and they were looking into solutions to reduce litter. Further litter distribution documentation through Citizen Science is needed to improve public awareness. Additionally, future research will be focused on Drone imagery of highly concentrated litter areas. Finally, a time series analysis of litter distribution will help us determine whether public education through Citizen Science and Story Maps can assist in reducing litter and reaching a cleaner and healthier environment.

Keywords: citizen science, litter pollution, Open Litter Map, GIS Story Map

Procedia PDF Downloads 79

Authors: Imas Istiani

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The concept of home is usually closely related to the place of safety and security. For people who have travelled far and long, they long to be united with home to feel safe, secure and comfortable. However, for some people, especially for veterans, home cannot offer them those feelings, on the contrary, it can give them the sense of insecurity as well as guilty. Thus, its juxtaposed concept can also put home as an uncanny place that represses and haunt its occupant. As for veterans, 'survivor guilt' overpowers them in the way that it will be hard for them to embrace the comfort that home offers. In Home, Toni Morrison poignantly depicts Frank’s life upon returning from the war. Burdened with his traumatic experiences, Frank finds home full with terror, guilt, fear, grief, and loss. Using Dominick laCapra’s 'Trauma Theory,' the study finds that Frank works through his trauma by being able to distinguish between past and present so that he can overcome those repressed feelings. Aside from his inner healing power, Frank digests the process of working through with the help of home and community, as proposed by Evelyn Jaffe Schreiber claiming that community can help survivors to heal from traumatic experiences. Thus, Home has two juxtaposed functions; both as traumatizing and healing place.

Keywords: trauma, healing, home, trauma theory

Procedia PDF Downloads 293

Authors: Arsenio Jose Mindu

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The concern to carry out a study related to Energy Efficiency arose based on the various debates in international television networks and not only, but also in several forums of national debates. The concept of Energy Efficiency is not yet widely disseminated and /or taken into account in terms of energy consumption, not only at the domestic level but also at the industrial level in Mozambique. In the context of the energy audit, the time during which each of the appliances is connected to the voltage source, the time during which they are in standby mode was recorded on a spreadsheet basis. Based on these data, daily and monthly consumption was calculated. In order to have more accurate information on the daily levels of daily consumption, the electricity consumption was read every hour of the day (from 5:00 am to 11:00 pm), since after 23:00 the energy consumption remains constant. For ten days. Based on the daily energy consumption and the maximum consumption power, the design of the photovoltaic system for the residence was made. With the implementation of the photovoltaic system in order to guarantee energy efficiency, there was a significant reduction in the use of electricity from the public grid, increasing from approximately 17 kwh per day to around 11 kwh, thus achieving an energy efficiency of 67.4 %. That is to say, there was a reduction not only in terms of the amount of energy consumed but also of the monthly expenses with electricity, having increased from around 2,500,00Mt (2,500 meticais) to around 800Mt per month.

Keywords: energy efficiency, photovoltaic system, residential sector, Mozambique

Procedia PDF Downloads 206

Authors: Junaid Jibran Jawed, Prasanta Saini, Subrata Majumdar

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Background: Leishmania donovani infection causes severe host immune-suppression through the modulation of pathogen recognition receptors. Apart from TLRs (Toll Like Receptor), recent studies focus on the important contribution of NLR (NOD-Like Receptor) family member NOD1 and NOD2 as these receptors are capable of triggering host innate immunity. The aim of this study was to decipher the role of NOD1/NOD2 receptors during experimental visceral leishmaniasis (VL) and the important link between host failure and parasite evasion strategy. Method: The status of NOD1 and NOD2 receptors were analysed in uninfected and infected cells through western blotting and RT-PCR. The active contributions of these receptors in reducing parasite burden were confirmed by siRNA mediated silencing, and over-expression studies and the parasite numbers were calculated through microscopic examination of the Giemsa-stained slides. In-vivo studies were done by using non-toxic dose of Mw (Mycobacterium indicus pranii), Ara-LAM(Arabinoasylated lipoarabinomannan) along with MDP (Muramyl dipeptide) administration. Result: Leishmania donovani infection of the macrophages reduced the expression of NOD2 receptors whereas NOD1 remain unaffected. MDP, a NOD2-ligand, treatment during over-expression of NOD2, reduced the parasite burden effectively which was associated with increased pro-inflammatory cytokine generation and NO production. In experimental mouse model, Ara-LAM treatment increased the expression of NOD2 and in combination with MDP it showed active therapeutic potential against VL and found to be more effective than Mw which was already reported to be involved in NOD2 modulation. Conclusion: This work explores the essential contribution of NOD2 during experimental VL and mechanistic understanding of Ara-LAM + MDP combination therapy to work against this disease and highlighted NOD2 as an essential therapeutic target.

Keywords: Ara-LAM (Arabinoacylated Lipoarabinomannan), NOD2 (nucleotide binding oligomerization receptor 2), MDP (muramyl di peptide), visceral Leishmaniasis

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Authors: Sela Adjei

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This paper aims to rationalize the need for media policy implementation and copyright enforcement to address various challenges faced within Ghana’s film industry. After Ghana transitioned to democratic rule in 1992, critics and media professionals advocated a national media policy. This advocacy subsequently resulted in agitation for media deregulation and loosening of grip on state-owned media organizations. The reinstatement of constitutional rule in 1992 paved the way for the state to lax its monopoly of the media within the democratic context of a free market economy. The National Media Commission proposed a media policy and broadcast bill which was presented to parliament but has still not been passed into law. This legislative lapse partly contributed to the influx of unregulated foreign content. Accessible foreign media content subsequently promoted a system of unfair competition that radically undermined locally produced content, putting a generation of thriving film producers out of work. Drawing on reflections from a series of structured interviews, focus group discussions and creative workshops, the findings of this study maintain that the various challenges confronting Ghanaian filmmakers is centred around inadequate funding opportunities, copyright violation and policy implementation issues. Using the film industry structure and value chain analysis, the various challenges faced by the selected film producers were discussed and critically analyzed. A significant aspect of this study is the solution-driven approach adopted in outlining the practical recommendations that will boost the aesthetic, cultural and economic value of Ghanaian film productions. Based on the discussions and conclusions drawn with the various stakeholders within Ghana’s creative industries, the paper makes a strong case for firm state regulation, copyright enforcement and policy implementation to grow Ghana’s film industry.

Keywords: film, value, copyright, media, policy, culture, regulation, economy

Procedia PDF Downloads 69

Authors: Tushar Vasant Salunkhe, Sariput M. Nawghare, Maheboobsab B. Nadaf, Sushovan Dutta, J. N. Mandal

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The model tests were conducted in the laboratory without and with plastic recycled polymer in fly ash steep slopes overlaying soft foundation soils like fly ash and power soil in order to check the stability of steep slope. In this experiment, fly ash is used as a filling material, and Plastic Recycled Polymers of diameter = 3mm and length = 4mm were made from the waste plastic product (lower grade plastic product). The properties of fly ash and plastic recycled polymers are determined. From the experiments, load and settlement have measured. From these data, load–settlement curves have been reported. It has been observed from test results that the load carrying capacity of mixture fly ash with Plastic Recycled Polymers slope is more than that of fly ash slope. The deformation of Plastic Recycled Polymers slope is slightly more than that of fly ash slope. A Finite Element Method (F.E.M.) was also evaluated using PLAXIS 3D version. The failure pattern, deformations and factor of safety are reported based on analytical programme. The results from experimental data and analytical programme are compared and reported.

Keywords: factor of safety, finite element method (FEM), fly ash, plastic recycled polymer

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Authors: Ensieh Hajeb, Hefzollah Mohammadiyan, Mohamad Baqer Heidari

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In this paper layout plans and determine the best place to install a heat recovery boilers , gas turbines , and simulation models built to evaluate the performance of the design and operating conditions, heat recovery boiler design using model built on the basis of operating conditions , the effect of various parameters on the performance of the designed heat recovery boiler , heat recovery boiler installation was designed to evaluate the technical and economic impact on performance would be Turbo generator. Given the importance of this issue, that is the main goal of economic efficiency and reduces costs; this project has been implemented similar plans in which the target is implementation specific patterns. The project will also help us in the process of gas refineries and the actual efficiency of the process after adding a system to analyze the turbine and predict potential problems and how to fix them and appropriate measures according to the results of simulation analysis and results of the process gain. The results of modeling and the effect of different parameters on this line, the software has been ThermoFlow.

Keywords: boiler, gas turbine, turbo generator, power flow

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Authors: I. Kamika, S. Azizi, M. Tekere

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Nanotechnology promises significant improvements of advanced materials and manufacturing techniques with a vast range of applications, which are critical for the future competitiveness of national industries. The manipulations and productions of materials, whilst, controlling the optical properties and surface area to a nanosize scale enabled a birth of a new field known as nanotechnology. However, their rapidly developing industry raises concerns about the environmental impacts of nanoparticles, as their effects on functional bacterial community in wastewater treatment remain unclear. The present research assessed the impact of cerium Oxide nanoparticles (nCeO) on the bacterial microbiome of an activated sludge system, which influenced its performance of this system on nutrient removal. Out of 15875 reads sequenced, a total of 13133 reads were non-chimeric. The wastewater samples were more dominant to the unclassified bacteria (51.07% of bacteria community) followed with the classified bacteria (48.93). Proteobacteria was the most dominant phylum in both classified and unclassified bacteria, whereas 18% of bacteria could even not be assigned a phylum and remained unclassified suggesting hitherto vast untapped microbial diversity. The bacterial operational taxonomic units (OTUs) ranged from 1014 to 2629 over the experimental period. The denitrification related species including Diaphorobacter species, Thauera species and those in the Sphaerotilus and Leptothrix group were found to be inhibited in a high concentration of CeO-NP. The diversity indices suggested that the bacterial community inhabiting the wastewater samples were less diverse as the concentration of CeO increases. The canonical correspondence analysis (CCA) results highlighted that the bacterial community variance had the strongest relationship with water temperature, conductivity, pH, and dissolved oxygen (DO) content as well as nCeO. The results provided the relationships between the microbial community and environmental variables in the wastewater samples.

Keywords: bacterial community, next generation, cerium oxide, wastewater, activated sludge, nanoparticles, nanotechnology

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Authors: Po-Sheng Kuo, Che-Wei Lu, Ssu-Ching Chen

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Chlorinated ethenes (CEs) constitute a predominant contaminant in Taiwan's native polluted sites, particularly in groundwater inundated with sulfate salts that substantially impede remediation efforts. The reduction of sulfate by sulfate-reducing bacteria (SRB) impairs the dechlorination efficiency of Dehalococcoides by generating hydrogen sulfide (H₂S), resulting in incomplete chloride degradation and thereby leading to the failure of bioremediation. In order to elucidate interactions between sulfate reduction and dechlorination, this study aims to establish a co-culture system of Dehalococcoides and SRB, overcoming H₂S inhibition by employing the synthesis of ferrous sulfide (FeS), which is commonly utilized in chemical remediation due to its high reduction potential. Initially, the study demonstrates that the addition of ferrous chloride (FeCl₂) effectively removed H₂S production from SRB and enhanced the degradation of trichloroethylene to ethene. This process overcomes the inhibition caused by H₂S produced by SRB in high sulfate environments. Compared to different concentrations of ferrous dosages for the biogenic generation of FeS, the efficiency was optimized by adding FeCl₂ at an equal ratio to the concentration of sulfate in the environment. This was more effective in removing H₂S and crystal particles under 10 times smaller than those synthesized under excessive FeCl₂ dosages, addressing clogging issues in situ remediation. Finally, utilizing Taiwan's indigenous dechlorinating consortium in a simulated high sulfate-contaminated environment, the biodiversity of microbial species was analyzed to reveal a higher species richness within the FeS group, conducive to ecological stability. This study validates the potential of the co-culture system in generating biogenic FeS under sulfate and CEs co-contamination, removing sulfate-reducing products, and improving CE remediation through integrated chemical and biological remediations.

Keywords: biogenic ferrous sulfide, chlorinated ethenes, Dehalococcoides, sulfate-reducing bacteria, sulfide inhibition

Procedia PDF Downloads 51

Authors: N. Singh, G. K. Darbha

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Since the last decade, a wave of research has begun to study the prevalence and impact of ever-increasing plastic pollution in the environment. The wide application and ubiquitous distribution of plastic have become a global concern due to its persistent nature. The disposal of plastics has emerged as one of the major challenges for waste management landfills. Microplastics (MPs) have found its existence in almost every environment, from the high altitude mountain lake to the deep sea sediments, polar icebergs, coral reefs, estuaries, beaches, and river, etc. Microplastics are fragments of plastics with size less than 5 mm. Microplastics can be classified as primary microplastics and secondary microplastics. Primary microplastics includes purposefully introduced microplastics into the end products for consumers (microbeads used in facial cleansers, personal care product, etc.), pellets (used in manufacturing industries) or fibres (from textile industries) which finally enters into the environment. Secondary microplastics are formed by disintegration of larger fragments under the exposure of sunlight, mechanical abrasive forces by rain, waves, wind and/or water. A number of factors affect the quantity of microplastic present in freshwater environments. In addition to physical forces, human population density proximal to the water body, proximity to urban centres, water residence time, and size of the water body also affects plastic properties. With time, other complex processes in nature such as physical, chemical and biological break down plastics by interfering with its structural integrity. Several studies demonstrate that microplastics found in wastewater sludge being used as manure for agricultural fields, thus having the tendency to alter the soil environment condition influencing the microbial population as well. Inadequate data are available on the fate and transport of microplastics under varying environmental conditions that are required to supplement important information for further research. In addition, microplastics have the tendency to absorb heavy metals and hydrophobic organic contaminants such as PAHs and PCBs from its surroundings and thus acting as carriers for these contaminants in the environment system. In this study, three kinds of microplastics (polyethylene, polypropylene and expanded polystyrene) of different densities were chosen. Plastic samples were placed in sand with different aqueous media (distilled water, surface water, groundwater and marine water). It was incubated at varying temperatures (25, 35 and 40 °C) and agitation levels (rpm). The results show that the number of plastic fragments enhanced with increase in temperature and agitation speed. Moreover, the rate of disintegration of expanded polystyrene is high compared to other plastics. These results demonstrate that temperature, salinity, and mechanical abrasion plays a major role in degradation of plastics. Since weathered microplastics are more harmful as compared to the virgin microplastics, long-term studies involving other environmental factors are needed to have a better understanding of degradation of plastics.

Keywords: environmental contamination, fragmentation, microplastics, temperature, weathering

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Authors: Mimeche Leila, Debabeche Mahmoud

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It is question to study and to value the possibility of settling the process of purification by plants (constructed wetland) to treat the domestic waste water of Biskra, city in a semi-arid environment with grave problems of. According to the bibliography, the process of treatment by plants is considered as more advantageous than the classic techniques. It is the use of beds with macrophytes where the purification is made by the combined action of plants and micro-organisms in a filtering bed. The micro-organisms which are aerobic bacteria and\or anaerobic have for main function to degrade the polluting materials. Plants in the macrophytes beds have for function to serve as support in the development of bacteria and to favour also their development. In this study, we present a preliminary experimental analysis of the potentialities of treatment of some macrpohytes plants, implanted in basins filled of gravel. Analyses physico chemical and bacteriological of the waste water indicate a good elimination of the polluting materials, and put in evidence the purifier power of these plants, in association with bacteria. The obtained results seem to be interesting and encourage deepening the study for other types of plants in other conditions.

Keywords: constructed wetlands, macrophytes, sewage treatment, wastewater

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Authors: Jagdeep Nayak, Biswajit Paul, Anup Gupta

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Characterization of coal refuses to fly ash, and steel slag from steel industries have been performed to develop a mixture of both these materials to enhance strength properties of their utilization in other sectors like mine fill, construction work, etc. A large amount of Linz-Donawitz (LD) slag and fly ash waste are generated from steel and thermal power industries respectively. Management of these wastes is problematic, and their reutilization may provide a sustainable waste management option. LD slag and fly ash mixed in different proportions were tested to analyse the micro structural improvement and hardening rate of the matrix. Mixing of activators such as sodium hydroxide and potassium silicate with silica-alumina of LD slag-fly ash mixture, geopolymeric structure were found to be developed. The effect of geo-polymerization behaviour and subsequent structural rearrangement has been studied using compressibility; shear strength and permeability tests followed by micro-graphical analysis. Densification in the mixture was observed along with an improvement of geotechnical properties due to the addition of LD slag. Due to suitable strength characteristics of these two waste materials as mixture, it can be used in the various construction field or may be used as a filling material in mine voids.

Keywords: LD slag, fly-ash, geopolymer, strength property, compressibility

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Authors: Mohammed Shaath

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Aims Technological advancements in teaching and learning have made significant improvements over the past decade and have been incorporated in institutions to aid the learner’s experience. This review aims to assess whether Technology Enhanced Learning (TEL) pedagogy is more effective at improving students’ attitude and knowledge retention in orthodontic training than traditional methods. Methodology The searches comprised Systematic Reviews (SRs) related to the comparison of TEL and traditional teaching methods from the following databases: PubMed, SCOPUS, Medline, and Embase. One researcher performed the screening, data extraction, and analysis and assessed the risk of bias and quality using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR-2). Kirkpatrick’s 4-level evaluation model was used to evaluate the educational values. Results A sum of 34 SRs was identified after the removal of duplications and irrelevant SRs; 4 fit the inclusion criteria. On Level 1, students showed positivity to TEL methods, although acknowledging that the harder the platforms to use, the less favourable. Nonetheless, the students still showed high levels of acceptability. Level 2 showed there is no significant overall advantage of increased knowledge when it comes to TEL methods. One SR showed that certain aspects of study within orthodontics deliver a statistical improvement with TEL. Level 3 was the least reported on. Results showed that if left without time restrictions, TEL methods may be advantageous. Level 4 shows that both methods are equally as effective, but TEL has the potential to overtake traditional methods in the future as a form of active, student-centered approach. Conclusion TEL has a high level of acceptability and potential to improve learning in orthodontics. Current reviews have potential to be improved, but the biggest aspect that needs to be addressed is the primary study, which shows a lower level of evidence and heterogeneity in their results. As it stands, the replacement of traditional methods with TEL cannot be fully supported in an evidence-based manner. The potential of TEL methods has been recognized and is already starting to show some evidence of the ability to be more effective in some aspects of learning to cater for a more technology savvy generation.

Keywords: TEL, orthodontic, teaching, traditional

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Authors: Seyedeh Mozhgan Seyed-Talebi, Weng-Kent Chan, Hsin-Yi Tiffany Chen

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Lead-free perovskite photovoltaic (PV) technology employing non-toxic tin halide perovskite absorbers is pivotal for advancing perovskite solar cell (PSC) commercialization. Despite challenges posed by perovskite sensitivity to oxygen and humidity, our study utilizes DFT calculations using VASP and NanoDCAL software and SCAPS-1D simulations to elucidate the charge transport mechanism at the interface of CsSnI₃-FASnI₃ heterojunction. Results reveal how inherent electric fields facilitate efficient carrier transport, reducing recombination losses. We predict optimized power conversion efficiencies (PCEs) and highlight the potential of CsSnI3-FASnI3 heterojunctions for cost-effective and efficient charge transport layer-free (CTLF) photovoltaic devices. Our study provides insights into the future direction of recognizing more efficient, nontoxic heterojunction perovskite devices.

Keywords: charge transport layer free, CsSnI₃-FASnI₃ heterojunction, lead-free perovskite solar cell, tin halide perovskite., Charge transport layer free

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Authors: Mei Xutao, Nakano Kimihiko

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In order to enhance the energy harvesting efficiency, this paper presents a novel tri-stable energy harvesting system (TEHS), which is realized by the effect of magnetic force, in rotational motion to scavenge vibration energy. The device is meant to provide the power supply for wireless autonomous systems in low-frequency environment. The nonlinear TEHS is composed of the cantilever beam which is mounted on a rotating hub and partially covered by piezoelectric patch, a tip mass magnet in the end and two fixed magnets. A theoretical investigation using the Lagrangian formulation is derived to describe the motion of the energy harvesting system and the output voltage. Additionally, several numerical simulations were carried out to characterize the system under different external excitations and to validate its performance. The results demonstrated that TEHS owns a wide range of frequency of snap-through and high output voltage compared with the bi-stable energy harvesting system (BEHS). Moreover, some sets of experimental validations will be performed in the future work because the experimental setup is in the configuration now.

Keywords: piezoelectric beam, rotational motion, snap-through, tri-stable energy harvester

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Authors: Javeria Arain, Saad Malik

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The management of solid waste is a crucial and essential aspect of urban environmental management especially in a city with an ever increasing population such as Karachi. The total amount of municipal solid waste generated from Gulshan e Iqbal town on average is 444.48 tons per day and landfill sites are a widely accepted solution for final disposal of this waste. However, an improperly selected site can have immense environmental, economical and ecological impacts. To select an appropriate landfill site a number of factors should be kept into consideration to minimize the potential hazards of solid waste. The purpose of this research is to analyse the study area for the construction of an appropriate landfill site for disposal of municipal solid waste generated from Gulshan e-Iqbal Town by using geospatial techniques considering hydrological, geological, social and geomorphological factors. This was achieved using analytical hierarchy process and fuzzy analysis as a decision support tool with integration of geographic information sciences techniques. Eight most critical parameters, relevant to the study area, were selected. After generation of thematic layers for each parameter, overlay analysis was performed in ArcGIS 10.0 software. The results produced by both methods were then compared with each other and the final suitability map using AHP shows that 19% of the total area is Least Suitable, 6% is Suitable but avoided, 46% is Moderately Suitable, 26% is Suitable, 2% is Most Suitable and 1% is Restricted. In comparison the output map of fuzzy set theory is not in crisp logic rather it provides an output map with a range of 0-1, where 0 indicates least suitable and 1 indicates most suitable site. Considering the results it is deduced that the northern part of the city is appropriate for constructing the landfill site though a final decision for an optimal site could be made after field survey and considering economical and political factors.

Keywords: Analytical Hierarchy Process (AHP), fuzzy set theory, Geographic Information Sciences (GIS), Multi-Criteria Decision Analysis (MCDA)

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Authors: Zeyu Zhou, Ziyu Zhao, Xiaochen Yang, Ling AI, Heng Zhai, Stuart Holmes

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As a promising sustainable alternative to traditional fossil fuels, fuel cell technology is highly favoured due to its enhanced working efficiency and reduced emissions. In the context of high-temperature fuel cells (operating above 100 °C), the most commonly used proton exchange membrane (PEM) is the Polybenzimidazole (PBI) doped phosphoric acid (PA) membrane. Grafting is a promising strategy to advance PA-doped PBI PEM technology. The existing grafting modification on PBI PEMs mainly focuses on grafting phosphate-containing or alkaline groups onto the PBI molecular chains. However, quaternary ammonium-based grafting approaches face a common challenge. To initiate the N-alkylation reaction, deacidifying agents such as NaH, NaOH, KOH, K2CO3, etc., can lead to ionic crosslinking between the quaternary ammonium group and PBI. Polyvinylpyrrolidone (PVP) is another widely used polymer, the N-heterocycle groups within PVP endow it with a significant ability to absorb PA. Recently, PVP has attracted substantial attention in the field of fuel cells due to its reduced environmental impact and impressive fuel cell performance. However, due to the the poor compatibility of PVP in PBI, few research apply PVP in PA-doped PBI PEMs. This work introduces an innovative strategy to graft PVP onto PBI to form a network-like polymer. Due to the absence of quaternary ammonium groups, PVP does not pose issues related to crosslinking with PBI. Moreover, the nitrogen-containing functional groups on PVP provide PBI with a robust phosphoric acid retention ability. The nuclear magnetic resonance (NMR) hydrogen spectrum analysis results indicate the successful completion of the grafting reaction where N-alkylation reactions happen on both sides of the grafting agent 1,4-bis(chloromethyl)benzene. On one side, the reaction takes place with the hydrogen atoms on the imidazole groups of PBI, while on the other side, it reacts with the terminal amino group of PVP. The XPS results provide additional evidence from the perspective of the element. On synthesized PBI-g-PVP surfaces, there is an absence of chlorine (chlorine in grafting agent 1,4-bis(chloromethyl)benzene is substituted) element but a presence of sulfur element (sulfur element in terminal amino PVP appears in PBI), which demonstrates the occurrence of the grafting reaction and PVP is successfully grafted onto PBI. Prepare these modified membranes into MEA. It was found that during the fuel cell operation, all the grafted membranes showed substantial improvement in maximum current density and peak power density compared to unmodified one. For PBI-g-PVP 30, with a grafting degree of 22.4%, the peak power density reaches 1312 mW cm⁻², marking a 59.6% enhancement compared to the pristine PBI membrane. The improvement is caused by the improved PA binding ability of the membrane after grafting. The AST test result shows that the grafting membranes have better long-term durability and performance than unmodified membranes attributed to the presence of added PA binding sites, which can effectively prevent the PA leaching caused by proton migration. In conclusion, the test results indicate that grafting PVP onto PBI is a promising strategy which can effectively improve the fuel cell performance.

Keywords: fuel cell, grafting modification, PA doping ability, PVP

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Authors: Felix U. Asoiro, Meshack I. Simeon, Chinenye E. Azuka, Harami Solomon, Chukwuemeka J. Ohagwu

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The drying kinetics, specific energy consumed (SEC), effective moisture diffusivity (EMD), flavonoid, phenolic, and vitamin C contents of onion slices dried under convective oven drying (COD) were compared with microwave drying (MD). Drying was performed with onion slice thicknesses of 2, 4, 6, and 8 mm; air drying temperatures of 60, 80, and 100°C for COD, and microwave power of 450 W for MD. A decrease in slice thickness and an increase in drying air temperature led to a drop in the drying time. As thickness increased from 2 – 8 mm, EMD rose from 1.1-4.35 x 10⁻⁸ at 60°C, 1.1-5.6 x 10⁻⁸ at 80°C, and 1.25-6.12 x 10⁻⁸ at 100°C with MD treatments yielding the highest mean value (6.65 x 10⁻⁸ m² s⁻¹) at 8 mm. Maximum SEC for onion slices in COD was 238.27 kWh/kg H₂O (2 mm thickness), and the minimum was 39.4 kWh/kg H₂O (8 mm thickness) whereas maximum during MD was 25.33 kWh/kg H₂O (8 mm thickness) and minimum, 18.7 kWh/kg H₂O (2 mm thickness). MD treatment gave a significant (p 0.05) increase in the flavonoid (39.42 – 64.4%), phenolic (38.0 – 46.84%), and vitamin C (3.7 – 4.23 mg 100 g⁻¹) contents, while COD treatment at 60°C and 100°C had positive effects on only vitamin C and phenolic contents, respectively. In comparison, the Weibull model gave the overall best fit (highest R²=0.999; lowest SSE=0.0002, RSME=0.0123, and χ²= 0.0004) when drying 2 mm onion slices at 100°C.

Keywords: allium cepa, drying kinetics, specific energy consumption, flavonoid, vitamin C, microwave oven drying

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Authors: Ranjot Kaur, Om P. Katare, Anupama Sharma, Sarah R. Dennison, Kamalinder K. Singh, Bhupinder Singh

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Respiratory microbial infections being among the top leading cause of death worldwide are difficult to treat as the microbes reside deep inside the airways, where only a small fraction of drug can access after traditional oral or parenteral routes. As a result, high doses of drugs are required to maintain drug levels above minimum inhibitory concentrations (MIC) at the infection site, unfortunately leading to severe systemic side-effects. Therefore, delivering antimicrobials directly to the respiratory tract provides an attractive way out in such situations. In this context, current study embarks on the systematic development of lung lia pid-modified chitosan nanoparticles for inhalation of voriconazole. Following the principles of quality by design, the chitosan nanoparticles were prepared by ionic gelation method and further coated with major lung lipid by precipitation method. The factor screening studies were performed by fractional factorial design, followed by optimization of the nanoparticles by Box-Behnken Design. The optimized formulation has a particle size range of 170-180nm, PDI 0.3-0.4, zeta potential 14-17, entrapment efficiency 45-50% and drug loading of 3-5%. The presence of a lipid coating was confirmed by FESEM, FTIR, and X-RD. Furthermore, the nanoparticles were found to be safe upto 40µg/ml on A549 and Calu-3 cell lines. The quantitative and qualitative uptake studies also revealed the uptake of nanoparticles in lung epithelial cells. Moreover, the data from Spraytec and next-generation impactor studies confirmed the deposition of nanoparticles in lower airways. Also, the interaction of nanoparticles with DPPC monolayers signifies its biocompatibility with lungs. Overall, the study describes the methodology and potential of lipid-coated chitosan nanoparticles in futuristic inhalation nanomedicine for the management of pulmonary aspergillosis.

Keywords: dipalmitoylphosphatidylcholine, nebulization, DPPC monolayers, quality-by-design

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Authors: Dong Tang, Yongli Zhao

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The study of the microstructure of asphalt is of great importance for the analysis of its macroscopic properties. However, the peculiarities of the chemical composition of the asphalt itself and the limitations of existing direct imaging techniques have caused researchers to face many obstacles in studying the microstructure of asphalt. The advantage of small-angle X-ray scattering (SAXS) is that it allows quantitative determination of the internal structure of opaque materials and is suitable for analyzing the microstructure of materials. Therefore, the SAXS technique was used to study the evolution of microstructures on the nanoscale during asphalt aging. And the reasons for the change in scattering contrast during asphalt aging were also explained with the help of Fourier transform infrared spectroscopy (FTIR). SAXS experimental results show that the SAXS curves of asphalt are similar to the scattering curves of scattering objects with two-level structures. The Porod curve for asphalt shows that there is no obvious interface between the micelles and the surrounding mediums, and there is only a fluctuation of the hot electron density between the two. The Beaucage model fit SAXS patterns shows that the scattering coefficient P of the asphaltene clusters as well as the size of the micelles, gradually increase with the aging of the asphalt. Furthermore, aggregation exists between the micelles of asphalt and becomes more pronounced with increasing aging. During asphalt aging, the electron density difference between the micelles and the surrounding mediums gradually increases, leading to an increase in the scattering contrast of the asphalt. Under long-term aging conditions due to the gradual transition from maltenes to asphaltenes, the electron density difference between the micelles and the surrounding mediums decreases, resulting in a decrease in the scattering contrast of asphalt SAXS. Finally, this paper correlates the macroscopic properties of asphalt with microstructural parameters, and the results show that the high-temperature rutting resistance of asphalt is enhanced and the low-temperature cracking resistance decreases due to the aggregation of micelles and the generation of new micelles. These results are useful for understanding the relationship between changes in microstructure and changes in properties during asphalt aging and provide theoretical guidance for the regeneration of aged asphalt.

Keywords: asphalt, Beaucage model, microstructure, SAXS

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