Search results for: falling film
370 Immobilization of Cobalt Ions on F-Multi-Wall Carbon Nanotubes-Chitosan Thin Film: Preparation and Application for Paracetamol Detection
Authors: Shamima Akhter, Samira Bagheri, M. Shalauddin, Wan Jefrey Basirun
Abstract:
In the present study, a nanocomposite of f-MWCNTs-Chitosan was prepared by the immobilization of Co(II) transition metal through self-assembly method and used for the simultaneous voltammetric determination of paracetamol (PA). The composite material was characterized by field emission scanning electron microscopy (FESEM) and energy dispersive X-Ray analysis (EDX). The electroactivity of cobalt immobilized f-MWCNTs with excellent adsorptive polymer chitosan was assessed during the electro-oxidation of paracetamol. The resulting GCE modified f-MWCNTs/CTS-Co showed electrocatalytic activity towards the oxidation of PA. The electrochemical performances were investigated using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and differential pulse voltammetry (DPV) methods. Under favorable experimental conditions, differential pulse voltammetry showed a linear dynamic range for paracetamol solution in the range of 0.1 to 400µmol L⁻¹ with a detection limit of 0.01 µmol L⁻¹. The proposed sensor exhibited significant selectivity for the paracetamol detection. The proposed method was successfully applied for the determination of paracetamol in commercial tablets and human serum sample.Keywords: nanomaterials, paracetamol, electrochemical technique, multi-wall carbon nanotube
Procedia PDF Downloads 201369 Anti-Site Disorder Effects on the Magnetic Properties of Sm₂NiMnO₆ Thin Films
Authors: Geetanjali Singh, R. J. Choudhary, Anjana Dogra
Abstract:
Here we report the effects of anti-site disorder, present in the sample, on the magnetic properties of Sm₂NiMnO₆ (SNMO) thin films. To our best knowledge, there are no studies available on the thin films of SNMO. Thin films were grown using pulsed laser deposition technique on SrTiO₃ (STO) substrate under oxygen pressure of 800 mTorr. X-ray diffraction (XRD) profiles show that the film grown is epitaxial. Field cooled (FC) and zero field cooled (ZFC) magnetization curve increase as we decrease the temperature till ~135K. A broad dip was observed in both the curves below this temperature which is more dominating in ZFC curve. An additional sharp cusplike shape was observed at low temperature (~20 K) which is due to the re-entrant spin-glass like properties present in the sample. Super-exchange interaction between Ni²⁺-O-Mn⁴⁺ is attributed to the FM ordering in these samples. The spin-glass feature is due to anti-site disorder within the homogeneous sample which was stated to be due to the mixed valence states Ni³⁺ and Mn³⁺ present in the sample. Anti-site disorder was found to play very crucial role in different magnetic phases of the sample.Keywords: double perovskite, pulsed laser deposition, spin-glass, magnetization
Procedia PDF Downloads 262368 Basics for Corruption Reduction and Fraud Prevention in Industrial/Humanitarian Organizations through Supplier Management in Supply Chain Systems
Authors: Ibrahim Burki
Abstract:
Unfortunately, all organizations (Industrial and Humanitarian/ Non-governmental organizations) are prone to fraud and corruption in their supply chain management routines. The reputational and financial fallout can be disastrous. With the growing number of companies using suppliers based in the local market has certainly increased the threat of fraud as well as corruption. There are various potential threats like, poor or non-existent record keeping, purchasing of lower quality goods at higher price, excessive entertainment of staff by suppliers, deviations in communications between procurement staff and suppliers, such as calls or text messaging to mobile phones, staff demanding extended periods of notice before they allow an audit to take place, inexperienced buyers and more. But despite all the above-mentioned threats, this research paper emphasize upon the effectiveness of well-maintained vendor/s records and sorting/filtration of vendor/s to cut down the possible threats of corruption and fraud. This exercise is applied in a humanitarian organization of Pakistan but it is applicable to whole South Asia region due to the similarity of culture and contexts. In that firm, there were more than 550 (five hundred and fifty) registered vendors. As during the disasters or emergency phases requirements are met on urgent basis thus, providing golden opportunities for the fake companies or for the brother/sister companies of the already registered companies to be involved in the tendering process without declaration or even under some different (new) company’s name. Therefore, a list of required documents (along with checklist) was developed and sent to all of the vendor(s) in the current database and based upon the receipt of the requested documents vendors were sorted out. Furthermore, these vendors were divided into active (meeting the entire set criterion) and non-active groups. This initial filtration stage allowed the firm to continue its work without a complete shutdown that is only vendors falling in the active group shall be allowed to participate in the tenders by the time whole process is completed. Likewise only those companies or firms meeting the set criterion (active category) shall be allowed to get registered in the future along with a dedicated filing system (soft and hard shall be maintained), and all of the companies/firms in the active group shall be physically verified (visited) by the Committee comprising of senior members of at least Finance department, Supply Chain (other than procurement) and Security department.Keywords: corruption reduction, fraud prevention, supplier management, industrial/humanitarian organizations
Procedia PDF Downloads 539367 Recycling of Polymers in the Presence of Nanocatalysts: A Green Approach towards Sustainable Environment
Authors: Beena Sethi
Abstract:
This work involves the degradation of plastic waste in the presence of three different nanocatalysts. A thin film of LLDPE was formed with all three nanocatalysts separately in the solvent. Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetric (DSC) analysis of polymers suggest that the presence of these catalysts lowers the degradation temperature and the change mechanism of degradation. Gas chromatographic analysis was carried out for two films. In gas chromatography (GC) analysis, it was found that degradation of pure polymer produces only 32% C3/C4 hydrocarbons and 67.6% C5/C9 hydrocarbons. In the presence of these catalysts, more than 80% of polymer by weight was converted into either liquid or gaseous hydrocarbons. Change in the mechanism of degradation of polymer was observed therefore more C3/C4 hydrocarbons along with valuable feedstock are produced. Adjustment of dose of nanocatalyst, use of nano-admixtures and recycling of catalyst can make this catalytic feedstock recycling method a good tool to get sustainable environment. The obtained products can be utilized as fuel or can be transformed into other useful products. In accordance with the principles of sustainable development, chemical recycling i.e. tertiary recycling of polymers along with the reuse (zero order recycling) of plastics can be the most appropriate and promising method in this direction. The tertiary recycling is attracting much attention from the viewpoint of the energy resource.Keywords: degradation, differential scanning calorimetry, feedstock recycling, gas chromatography, thermogravimetric analysis
Procedia PDF Downloads 422366 Effect of the Deposition Time of Hydrogenated Nanocrystalline Si Grown on Porous Alumina Film on Glass Substrate by Plasma Processing Chemical Vapor Deposition
Authors: F. Laatar, S. Ktifa, H. Ezzaouia
Abstract:
Plasma Enhanced Chemical Vapor Deposition (PECVD) method is used to deposit hydrogenated nanocrystalline silicon films (nc-Si: H) on Porous Anodic Alumina Films (PAF) on glass substrate at different deposition duration. Influence of the deposition time on the physical properties of nc-Si: H grown on PAF was investigated through an extensive correlation between micro-structural and optical properties of these films. In this paper, we present an extensive study of the morphological, structural and optical properties of these films by Atomic Force Microscopy (AFM), X-Ray Diffraction (XRD) techniques and a UV-Vis-NIR spectrometer. It was found that the changes in DT can modify the films thickness, the surface roughness and eventually improve the optical properties of the composite. Optical properties (optical thicknesses, refractive indexes (n), absorption coefficients (α), extinction coefficients (k), and the values of the optical transitions EG) of this kind of samples were obtained using the data of the transmittance T and reflectance R spectra’s recorded by the UV–Vis–NIR spectrometer. We used Cauchy and Wemple–DiDomenico models for the analysis of the dispersion of the refractive index and the determination of the optical properties of these films.Keywords: hydragenated nanocrystalline silicon, plasma processing chemical vapor deposition, X-ray diffraction, optical properties
Procedia PDF Downloads 377365 Effect of Demineralized Water Purity on the Corrosion Behavior of Steel Alloys
Authors: A. M. El-Aziz, M. Elsehamy, H. Hussein
Abstract:
Steel or stainless steel have reasonable corrosion behavior in water, their corrosion resistance is significantly dependent on the water purity. It was not expected that demineralized water has an aggressive effect on steel alloys, in this study, the effect of water with different purity on steel X52 and stainless steel 316L was investigated. Weight loss and electrochemical measurements were employed to measure the corrosion behavior. Samples were microscopically investigated after test. It was observed that the higher the water purity the more reactive it is. Comparative analysis of the potentiodynamic curves for different water purity showed the aggressiveness of the demineralised water (conductivity of 0.05 microSiemens per cm) over the distilled water. Whereas, the corrosion rates of stainless steel 858 and 623 nm/y for demi and distilled water respectively. On the other hand, the corrosion rates of carbon steel x52 were estimated about 4.8 and 3.6 µm/y for demi and distilled water, respectively. Open circuit potential (OCP) recorded more positive potentials in case of stainless steel than carbon steel in different water purities. Generally, stainless steel illustrated high pitting resistance than carbon steel alloy, the surface film was investigated by scanning electron microscopy (SEM) and analyzed by energy dispersive X-ray spectroscopy (EDX). This behavior was explained based on that demi and distilled water might be considered as ‘hungry water’ in which it wants to be in equilibrium and will pull ions out of the surrounding metals trying to satisfy its ‘hunger’.Keywords: corrosion, demineralized water, distilled water, steel alloys
Procedia PDF Downloads 813364 Effects of Voltage Pulse Characteristics on Some Performance Parameters of LiₓCoO₂-based Resistive Switching Memory Devices
Authors: Van Son Nguyen, Van Huy Mai, Alec Moradpour, Pascale Auban Senzier, Claude Pasquier, Kang Wang, Pierre-Antoine Albouy, Marcelo J. Rozenberg, John Giapintzakis, Christian N. Mihailescu, Charis M. Orfanidou, Thomas Maroutian, Philippe Lecoeur, Guillaume Agnus, Pascal Aubert, Sylvain Franger, Raphaël Salot, Nathalie Brun, Katia March, David Alamarguy, Pascal ChréTien, Olivier Schneegans
Abstract:
In the field of Nanoelectronics, a major research activity is being developed towards non-volatile memories. To face the limitations of existing Flash memory cells (endurance, downscaling, rapidity…), new approaches are emerging, among them resistive switching memories (Re-RAM). In this work, we analysed the behaviour of LixCoO2 oxide thin films in electrode/film/electrode devices. Preliminary results have been obtained concerning the influence of bias pulses characteristics (duration, value) on some performance parameters, such as endurance and resistance ratio (ROFF/RON). Besides, Conducting Probe Atomic Force Microscopy (CP-AFM) characterizations of the devices have been carried out to better understand some causes of performance failure, and thus help optimizing the switching performance of such devices.Keywords: non volatile resistive memories, resistive switching, thin films, endurance
Procedia PDF Downloads 611363 The Impact of Insomnia on the Academic Performance of Mexican Medical Students: Gender Perspective
Authors: Paulina Ojeda, Damaris Estrella, Hector Rubio
Abstract:
Insomnia is a disorder characterized by difficulty falling asleep, staying asleep or both. It negatively affects the life quality of people, it hinders the concentration, attention, memory, motor skills, among other abilities that complicate work or learning. Some studies show that women are more susceptible to insomnia. Medicine curricula usually involve a great deal of theoretical and memory content, especially in the early years of the course. The way to accredit a university course is to demonstrate the level of competence or acquired knowledge. In Mexico the most widely used form of measurement is written exams, with numerical scales results. The prevalence of sleep disorders in university students is usually high, so it is important to know if insomnia has an effect on school performance in men and women. A cross-sectional study was designed that included a probabilistic sample of 118 regular students from the School of Medicine of the Autonomous University of Yucatan, Mexico. All on legally age. The project was authorized by the School of Medicine and all the ethical implications of the case were monitored. Participants completed anonymously the following questionnaires: Pittsburgh Sleep Quality Index, Insomnia Severity Index, AUDIT test, epidemiological and clinical data. Academic performance was assessed by the average number of official grades earned on written exams, as well as the number of approved or non-approved courses. These data were obtained officially through the corresponding school authorities. Students with at least one unapproved course or average less than 70 were considered to be poor performers. With all courses approved and average between 70-79 as regular performance and with an average of 80 or higher as a good performance. Statistical analysis: t-Student, difference of proportions and ANOVA. 65 men with a mean age of 19.15 ± 1.60 years and 53 women of 18.98 ± 1.23 years, were included. 96% of the women and 78.46% of the men sleep in the family home. 16.98% of women and 18.46% of men consume tobacco. Most students consume caffeinated beverages. 3.7% of the women and 10.76% of the men complete criteria of harmful consumption of alcohol. 98.11% of the women and 90.76% of the men are perceived with poor sleep quality. Insomnia was present in 73% of women and 66% of men. Women had higher levels of moderate insomnia (p=0.02) compared to men and only one woman had severe insomnia. 50.94% of the women and 44.61% of the men had poor academic performance. 18.86% of women and 27% of men performed well. Only in the group of women we found a significant association between poor performance with mild (p= 0.0035) and moderate (p=0.031) insomnia. The medical students reported poor sleep quality and insomnia. In women, levels of insomnia were associated with poor academic performance.Keywords: scholar-average, sex, sleep, university
Procedia PDF Downloads 296362 Schooling Competent Citizens: A Normative Analysis of Citizenship Education Policy in Europe
Authors: M. Joris, O. Agirdag
Abstract:
For over two decades, calls for citizenship education (CE) have been rising to the top of educational policy agendas in Europe. The main motive for the current treatment of CE as a key topic is a sense of crisis: social and political threats that go beyond the reach of nations and require action at the international and European level. On the one hand, this context has triggered abundant attention to the promotion of citizenship through education. On the other hand, the ubiquity of citizenship and education in policy language is paired with a self-evident manner of using the concepts: the more we call for citizenship in and through education, the less the concepts seem to be made explicit or be defined. Research and reflection on the normativity of the concepts of citizenship and CE in Europe are scarce. Departing from the idea that policies are always normative, this study, therefore, investigates the normativity of the current concepts of citizenship and education, in ’key’ European CE policy texts. The study consists of a content analysis of these texts, based on a normative framework developed around the different dimensions of citizenship as status, identity, virtues and agency. The framework also describes the purposes of education and its learning processes, content and practices, based on the assumption that good education always includes, next to qualification and socialisation, a purpose of emancipation: of helping young people become autonomous and independent subjects. The analysis shows how contemporary European citizenship is conceptualised around the dimension of competences. This focus on competences is also visible in the normative framing of education and its relationship to citizenship in the texts: CE should help young people learn how to become good citizens by acquiring a toolkit of competences, consisting of knowledge, skills, values and attitudes that can be predetermined, measured and evaluated. This ideal of citizenship-as-competence entails a focus on the educational purposes of socialisation and qualification. Current policy texts thus seem to leave out the educational purpose of emancipating young people, allowing them to take on citizenship as something to which they can determine their own relation and position. It is, however, this purpose of CE that seems increasingly important in our current context. Young people are stepping out of school and onto the streets by the thousands in Belgium and throughout Europe, protesting for more and better environmental policies. They are making use of existing modes of citizenship, exactly to indicate to policymakers how these are falling short and are claiming their right and entitlement to a future that established practices of politics are putting at risk. The importance of citizenship education might then lie, now more than ever, not in the fact that it would prepare young people for competent citizenship, but in offering them a possibility, an emancipatory experience of being able to do something new. It seems that this is what we might want to expect from the school if we want it to educate our truly future citizens.Keywords: citizenship education, normativity, policy, purposes of education
Procedia PDF Downloads 134361 Effect of Enzymatic Modification on the Crystallinity of Cellulose Pulps
Authors: J. Janicki, M. Rom, C. Slusarczyk, J. Fabia, M. Siika-aho, K. Marjamaa, K. Kruus, K. Langfelder, C. Steel, M. Paloheimo, T. Puranen, S. Mäkinen, D. Wawro
Abstract:
The cellulose is one of the most abundant polymers in the world, however, its application in the high-end value products such as films or fibres, it triggered by the cellulose properties. The noticeable presence of hydrogen bonding reflected with partially crystalline structure makes the cellulose insoluble in common solvents and not meltable. The existing technologies, such as viscose process, suffer from environmental and economical problems, because of the risk of harmful chemicals liberation during the spinning process. The enzymatic modification of cellulose with endoglucanase makes it directly alkali soluble in NaOH solution, giving the opportunities for film and fibers formation. As the effect of enzymatic treatment, there are observed changes in crystalline structure and accompanying changes of the affinity of cellulose to water, demonstrated by water retention value. The objective of the project ELMO - Novel carbohydrate modifying enzymes for fibre modification is is to develop new enzyme products for modification of dissolving grade pulps. The aim is to increase the reactivity of dissolving grade pulps and remove residual hemicellulose. The scientific aim of this paper is to present the effect of enzymatic treatment on the crystallinity and affinity to water of cellulose pulps modified with enzymes.Keywords: cellulose, crystallinity, WAXS, enzyme
Procedia PDF Downloads 236360 Lab Activities for Introducing Nanoscience to Teachers and Students
Authors: Riam Abu-Much, Muhamad Hugerat
Abstract:
Nanoscience has become one of the main science fields in the world; its importance is reflected in both society and industry; therefore, it is very important to intensify educational programs among teachers and students that aim to introduce "Nano Concepts" to them. Two different lab activities were developed for demonstrating the importance of nanoscale materials using unique points of view. In the first, electrical conductive films made of silver nanoparticles were fabricated. The silver nanoparticles were protected against aggregation using electrical conductive polypyrrole, which acts also as conductive bridge between them. The experiments show a simpler way for fabricating conductive thin film than the much more complicated and costly conventional method. In the second part, the participants could produce emulsions of liposome structures using Phosphatidylcholine as a surfactant, and following by minimizing the size of it from micro-scale to nanometer scale (400 nm), using simple apparatus called Mini-Extruder, in that way the participants could realize the change in solution transparency, and the effect of Tyndall when the size of the liposomes is reduced. Freshmen students from the Academic Arab College for Education in Haifa, Israel, who are studying to become science teachers, participated in this lab activity as part of the course "Chemistry in the Lab". These experiments are appropriate for teachers, high school and college students.Keywords: case study, colloid, emulsion, liposome, surfactant
Procedia PDF Downloads 202359 A Survey and Theory of the Effects of Various Hamlet Videos on Viewers’ Brains
Authors: Mark Pizzato
Abstract:
How do ideas, images, and emotions in stage-plays and videos affect us? Do they evoke a greater awareness (or cognitive reappraisal of emotions) through possible shifts between left-cortical, right-cortical, and subcortical networks? To address these questions, this presentation summarizes the research of various neuroscientists, especially Bernard Baars and others involved in Global Workspace Theory, Matthew Lieberman in social neuroscience, Iain McGilchrist on left and right cortical functions, and Jaak Panksepp on the subcortical circuits of primal emotions. Through such research, this presentation offers an ‘inner theatre’ model of the brain, regarding major hubs of neural networks and our animal ancestry. It also considers recent experiments, by Mario Beauregard, on the cognitive reappraisal of sad, erotic, and aversive film clips. Finally, it applies the inner-theatre model and related research to survey results of theatre students who read and then watched the ‘To be or not to be’ speech in 8 different video versions (from stage and screen productions) of William Shakespeare’s Hamlet. Findings show that students become aware of left-cortical, right-cortical, and subcortical brain functions—and shifts between them—through staging and movie-making choices in each of the different videos.Keywords: cognitive reappraisal, Hamlet, neuroscience, Shakespeare, theatre
Procedia PDF Downloads 315358 A Crossover between Avant-Garde Fashion and Contemporary Art: A Case Study of Alexander McQueen
Authors: Chi-Ying Yu
Abstract:
Fashion design is, in fact, an aesthetic inquiry of fabric, style and human body. In recent years, close cooperation between the artistic circles and the fashion world has even brought fashion into the arena of contemporary art. This study offers a case study on the avant-garde fashion designer Alexander McQueen, investigating how he and his brand translate fashion into contemporary art at various levels. Firstly, in terms of his designs themselves, McQueen demonstrates through fashions his declarations on political and gender issues, demonstrating his unique barbarian aesthetics and creating an enchanting sublimity. Secondly, McQueen extends his fashion aesthetics into a cross-disciplinary performing method, and raises catwalk shows to the level of complete artistic experience. Finally, and also most importantly, the brand has been producing fashion movies for its seasonal design series. By means of an abstract, non-narrative visual language, these films essentially transform people’s experience of clothing – from the senses to the pure visual. This is not simply a cross-media artistic practice, but much more fundamentally a discourse on contemporary perceptual experience. From the case of Alexander McQueen, it can be argued that avant-garde fashion has broken through the boundary between design and art, issuing its own art manifesto through the field of art or non-art.Keywords: Alexander McQueen, avant-garde fashion, contemporary art, fashion film
Procedia PDF Downloads 330357 Evidence on the Nature and Extent of Fall in Oil Prices on the Financial Performance of Listed Companies: A Ratio Analysis Case Study of the Insurance Sector in the UAE
Authors: Pallavi Kishore, Mariam Aslam
Abstract:
The sharp decline in oil prices that started in 2014 affected most economies in the world either positively or negatively. In some economies, particularly the oil exporting countries, the effects were felt immediately. The Gulf Cooperation Council’s (GCC henceforth) countries are oil and gas-dependent with the largest oil reserves in the world. UAE (United Arab Emirates) has been striving to diversify away from oil and expects higher non-oil growth in 2018. These two factors, falling oil prices and the economy strategizing away from oil dependence, make a compelling case to study the financial performance of various sectors in the economy. Among other sectors, the insurance sector is widely recognized as an important indicator of the health of the economy. An expanding population, surge in construction and infrastructure, increased life expectancy, greater expenditure on automobiles and other luxury goods translate to a booming insurance sector. A slow-down of the insurance sector, on the other hand, may indicate a general slow-down in the economy. Therefore, a study on the insurance sector will help understand the general nature of the current economy. This study involves calculations and comparisons of ratios pre and post the fall in oil prices in the insurance sector in the UAE. A sample of 33 companies listed on the official stock exchanges of UAE-Dubai Financial Market and Abu Dhabi Stock Exchange were collected and empirical analysis employed to study the financial performance pre and post fall in oil prices. Ratios were calculated in 5 categories: Profitability, Liquidity, Leverage, Efficiency, and Investment. The means pre- and post-fall are compared to conclude that the profitability ratios including ROSF (Return on Shareholder Funds), ROCE (Return on Capital Employed) and NPM (Net Profit Margin) have all taken a hit. Parametric tests, including paired t-test, concludes that while the fall in profitability ratios is statistically significant, the other ratios have been quite stable in the period. The efficiency, liquidity, gearing and investment ratios have not been severely affected by the fall in oil prices. This may be due to the implementation of stronger regulatory policies and is a testimony to the diversification into the non-oil economy. The regulatory authorities can use the findings of this study to ensure transparency in revealing financial information to the public and employ policies that will help further the health of the economy. The study will also help understand which areas within the sector could benefit from more regulations.Keywords: UAE, insurance sector, ratio analysis, oil price, profitability, liquidity, gearing, investment, efficiency
Procedia PDF Downloads 244356 Randomly Casted Single-Wall Carbon Nanotubes Films for High Performance Hybrid Photovoltaic Devices
Authors: My Ali El Khakani
Abstract:
Single-wall Carbon nanotubes (SWCNTs) possess an unprecedented combination of unique properties that make them highly promising for suitable for a new generation of photovoltaic (PV) devices. Prior to discussing the integration of SWCNTs films into effective PV devices, we will briefly highlight our work on the synthesis of SWCNTs by means of the KrF pulsed laser deposition technique, their purification and transfer onto n-silicon substrates to form p-n junctions. Some of the structural and optoelectronic properties of SWCNTs relevant to PV applications will be emphasized. By varying the SWCNTs film density (µg/cm2), we were able to point out the existence of an optimum value that yields the highest photoconversion efficiency (PCE) of ~10%. Further control of the doping of the p-SWCNTs films, through their exposure to nitric acid vapors, along with the insertion of an optimized hole-extraction-layer in the p-SWCNTs/n-Si hybrid devices permitted to achieve a PCE value as high as 14.2%. Such a high PCE value demonstrates the full potential of these p-SWCNTs/n-Si devices for sunlight photoconversion. On the other hand, by examining both the optical transmission and electrical conductance of the SWCNTs’ films, we established a figure of merit (FOM) that was shown to correlate well with the PCE performance. Such a direct relationship between the FOM and the PCE can be used as a guide for further PCE enhancement of these novel p-SWCNTs/n-Si PV devices.Keywords: carbon nanotubes (CNTs), CNTs-silicon hybrid devices, photoconversion, photovoltaic devices, pulsed laser deposition
Procedia PDF Downloads 118355 Queer Social Realism and Architecture in British Cinema: Tenement Housing, Unions and the Affective Body
Authors: Christopher Pullen
Abstract:
This paper explores the significance of British cinema in the late 1950s and early 1960s as offering a renaissance of realist discourse, in the representation of everyday social issues. Offering a rejection of Hollywood cinema and the superficially of the middle classes, these ‘kitchen sink dramas’ often set within modest and sometimes squalid domestic and social environments, focused on the political struggle of the disenfranchised examining poverty, the oppressed and the outsider. While films like Look Back in Anger and Room at the Top looked primarily at male heterosexual subjectivity, films like A Taste of Honey and Victim focused on female and queer male narratives. Framing the urban landscape as a discursive architectural arena, representing basic living conditions and threatening social worlds, these iconic films established new storytelling processes for the outsider. This paper examines this historical context foregrounding the contemporary films Beautiful Thing (Hettie Macdonald, 1996), Weekend (Andrew Haigh, 2011) and Pride (Marcus Warchus, 2014), while employing the process of textual analysis in relation to theories of affect, defined by writers such as Lisa U. Marks and Sara Ahmed. Considering both romance narratives and public demonstrations of unity, where the queer ‘affective’ body is placed within architectural and social space, Beautiful Thing tells the story of gay male teenagers falling in love despite oppression from family and school, Weekend examines a one-night stand between young gay men and the unlikeliness of commitment, but the drive for sensitivity, and Pride foregrounds an historical relationship between queer youth activists and the miner’s union, who were on strike between 1984-5. These films frame the queer ‘affective’ body within politicized public space, evident in lower class men’s working clubs, tenement housing and brutal modernist tower blocks, focusing on architectural features such as windows, doorways and staircases, relating temporality, desire and change. Through such an examination a hidden history of gay male performativity is revealed, framing the potential of contemporary cinema to focus on the context of the outsider in encouraging social change.Keywords: queer, affect, cinema, architecture, life chances
Procedia PDF Downloads 358354 Electrochemical Determination of Caffeine Content in Ethiopian Coffee Samples Using Lignin Modified Glassy Carbon Electrode
Authors: Meareg Amare, Senait Aklog
Abstract:
Lignin film was deposited at the surface of the glassy carbon electrode potential-statically. In contrast to the unmodified glassy carbon electrode, an oxidative peak with an improved current and overpotential for caffeine at the modified electrode showed catalytic activity of the modifier towards oxidation of caffeine. Linear dependence of peak current on caffeine concentration in the range 6 × 10⁻⁶ to 100 × 10⁻⁶ mol L⁻¹ with determination coefficient and method detection limit (LoD = 3 s/slope) of 0.99925 and 8.37 × 10⁻⁷ mol L⁻¹, respectively, supplemented by recovery results of 93.79–102.17%, validated the developed method. An attempt was made to determine the caffeine content of aqueous coffee extracts of Ethiopian coffees grown in four coffee cultivating localities (Wonbera, Wolega, Finoteselam, and Zegie) and hence to evaluate the correlation between users preference and caffeine content. In agreement with reported works, caffeine contents (w/w%) of 0.164 in Wonbera coffee; 0.134 in Wolega coffee; 0.097 in Finoteselam coffee; and 0.089 in Zegie coffee were detected, confirming the applicability of the developed method for determination of caffeine in a complex matrix environment. The result indicated that users’ highest preference for Wonbera and least preference for Zegie cultivated coffees are in agreement with the caffeine content.Keywords: electrochemical, lignin, caffeine, electrode
Procedia PDF Downloads 119353 Effect on Physicochemical and Sensory Attributes of Bread Substituted with Different Levels of Matured Soursop (Anona muricata) Flour
Authors: Mardiana Ahamad Zabidi, Akmalluddin Md. Yunus
Abstract:
Soursop (Anona muricata) is one of the underutilized tropical fruits containing nutrients, particularly dietary fibre and antioxidant properties that are beneficial to human health. This objective of this study is to investigate the feasibility of matured soursop pulp flour (SPF) to be substituted with high-protein wheat flour in bread. Bread formulation was substituted with different levels of SPF (0%, 5%, 10% and 15%). The effect on physicochemical properties and sensory attributes were evaluated. Higher substitution level of SPF resulted in significantly higher (p<0.05) fibre, protein and ash content, while fat and carbohydrate content reduced significantly (p<0.05). FESEM showed that the bread crumb surface of control and 5% SPF appeared to distribute evenly and coalesced by thin gluten film. However, higher SPF substitution level in bread formulation exhibited a deleterious effect by formation of discontinuous gluten network. For texture profile analysis, 5% SPF bread resulted in the lowest value of hardness. The score of sensory evaluation showed that 5% SPF bread received good acceptability and is comparable with control bread.Keywords: soursop pulp flour, bread, physicochemical properties, sensory attributes, scanning electron microscopy (SEM)
Procedia PDF Downloads 322352 Hydrogeochemical Assessment of Groundwater in Selected Part of Benue State Southern, Nigeria
Authors: Moses Oghenenyoreme Eyankware, Christian Ogubuchi Ede
Abstract:
Groundwater is the principal source for various uses in this study area. The quality and availability of groundwater depend on rock formation within the study area. To effectively study the quality of groundwater, 24 groundwater samples were collected. The study was aimed at investigating the hydrogeochemistry of groundwater, and additionally its suitability for drinking and irrigation purposes. The following parameters were analyzed using the American Public Health Association standard method: pH, turbidity, Ec, TDS, Mg2+, SO42-, NO3¯, Cl-, HCO3¯, K+, Na2+ and Ca2+. Results obtained from Water Quality Index revealed that the groundwater sample fell within good water quality that implies that groundwater is considered fit for drinking purposes. Deduced results obtained from irrigation indices revealed that Permeability Index (PI), Soluble Sodium Percentage (SSP), Sodium Percentage (Na %), Sodium Absorption Ratio (SAR), Kelly Ratio (KR), Magnesium Hazard (MH) ranges from 0.00 to 0.01, 4.04 to 412.9, 0.63 to 257.7, 0.15 to 2.34, 0.09 to 2.57 and 6.84 to 84.55 respectively. Findings from Total hardness revealed that groundwater fell within soft, moderately hard and hard categories. Estimated results obtained from CSMR, RI and LSI showed that groundwater showed corrosion tendency, salinization influenced groundwater at certain sampling points and chloride and sulfate unlikely to interfere with natural formation film.Keywords: water, quality, suitability, anthropogenic, Nigeria
Procedia PDF Downloads 223351 Momentum in the Stock Exchange of Thailand
Authors: Mussa Hussaini, Supasith Chonglerttham
Abstract:
Stocks are usually classified according to their characteristics which are unique enough such that the performance of each category can be differentiated from another. The reasons behind such classifications in the financial market are sometimes financial innovation or it can also be because of finding a premium in a group of stocks with similar features. One of the major classifications in stocks market is called momentum strategy. Based on this strategy stocks are classified according to their past performances into past winners and past losers. Momentum in a stock market refers to the idea that stocks will keep moving in the same direction. In other word, stocks with rising prices (past winners stocks) will continue to rise and those stocks with falling prices (past losers stocks) will continue to fall. The performance of this classification has been well documented in numerous studies in different countries. These studies suggest that past winners tend to outperform past losers in the future. However, academic research in this direction has been limited in countries such as Thailand and to the best of our knowledge, there has been no such study in Thailand after the financial crisis of 1997. The significance of this study stems from the fact that Thailand is an open market and has been encouraging foreign investments as one of the means to enhance employment, promote economic development, and technology transfer and the main equity market in Thailand, the Stock Exchange of Thailand is a crucial channel for Foreign Investment inflow into the country. The equity market size in Thailand increased from $1.72 billion in 1984 to $133.66 billion in 1993, an increase of over 77 times within a decade. The main contribution of this paper is evidence for size category in the context of the equity market in Thailand. Almost all previous studies have focused solely on large stocks or indices. This paper extends the scope beyond large stocks and indices by including small and tiny stocks as well. Further, since there is a distinct absence of detailed academic research on momentum strategy in the Stock Exchange of Thailand after the crisis, this paper also contributes to the extension of existing literature of the study. This research is also of significance for those researchers who would like to compare the performance of this strategy in different countries and markets. In the Stock Exchange of Thailand, we examined the performance of momentum strategy from 2010 to 2014. Returns on portfolios are calculated on monthly basis. Our results on momentum strategy confirm that there is positive momentum profit in large size stocks whereas there is negative momentum profit in small size stocks during the period of 2010 to 2014. Furthermore, the equal weighted average of momentum profit of both small and large size category do not provide any indication of overall momentum profit.Keywords: momentum strategy, past loser, past winner, stock exchange of Thailand
Procedia PDF Downloads 317350 The Impact of Migrants’ Remittances on Household Poverty and Income Inequality: A Case Study of Mazar-i-Sharif, Balkh Province, Afghanistan
Authors: Baqir Khawari
Abstract:
This study critically examines the influence of remittances on household poverty and income inequality in Mazar-i-Sharif, Balkh Province, Afghanistan, utilizing robust OLS and Logit models with a rigorous multi-random sampling method. The empirical findings reveal that a 1% increase in per capita international remittances is associated with a substantial 0.071% and 0.059% rise in per capita income during the fiscal years 2019/20 and 2020/21, respectively. Furthermore, this increase significantly mitigates the per capita depth of poverty by 0.0272% and 0.025% and the severity of poverty by 0.0149% and 0.0145% over the same periods. Notably, the impact of international remittances on poverty alleviation surpasses that of internal remittances. In addressing income inequality, the analysis demonstrates that remittances contribute to a reduction in the Gini coefficient by 2% in 2019/20 and 7% in 2020/21, underscoring their pivotal role in promoting equitable economic distribution. However, the COVID-19 pandemic has posed significant challenges, diminishing remittance flows and, consequently, their positive effects on household welfare. The logistic regression results further corroborate these findings, indicating that increased per capita remittances, both international and internal, markedly decrease the likelihood of households falling below the poverty line. Specifically, a 1% rise in per capita external remittances reduces this likelihood by 4.5% in 2019/20 and by 3.7% in 2020/21, while internal remittances decrease it by 3% and 2.4%, respectively. The study also explores the demographic determinants of poverty. Larger household sizes and older household heads correlate positively with poverty, whereas higher education levels among household heads and members, and a greater proportion of male members, correlate negatively with poverty incidence and severity. Female-headed households are disproportionately affected by poverty, exacerbated by socio-cultural restrictions. Despite these adversities, the data suggest that remittances are a crucial instrument for poverty alleviation and income inequality reduction in Afghanistan. The findings advocate for policy interventions aimed at enhancing formal remittance channels, promoting education, and empowering women. Effective governance and sustained international assistance are essential to harness the full potential of remittances in combating poverty and inequality. This study highlights the need for strategic, multifaceted approaches to foster sustainable economic development in Afghanistan’s challenging socio-political context.Keywords: migration, remittances, poverty, inequality, COVID-19, Afghanistan
Procedia PDF Downloads 34349 Experimental Proof of Concept for Piezoelectric Flow Harvesting for In-Pipe Metering Systems
Authors: Sherif Keddis, Rafik Mitry, Norbert Schwesinger
Abstract:
Intelligent networking of devices has rapidly been gaining importance over the past years and with recent advances in the fields of microcontrollers, integrated circuits and wireless communication, low power applications have emerged, enabling this trend even more. Connected devices provide a much larger database thus enabling highly intelligent and accurate systems. Ensuring safe drinking water is one of the fields that require constant monitoring and can benefit from an increased accuracy. Monitoring is mainly achieved either through complex measures, such as collecting samples from the points of use, or through metering systems typically distant to the points of use which deliver less accurate assessments of the quality of water. Constant metering near the points of use is complicated due to their inaccessibility; e.g. buried water pipes, locked spaces, which makes system maintenance extremely difficult and often unviable. The research presented here attempts to overcome this challenge by providing these systems with enough energy through a flow harvester inside the pipe thus eliminating the maintenance requirements in terms of battery replacements or containment of leakage resulting from wiring such systems. The proposed flow harvester exploits the piezoelectric properties of polyvinylidene difluoride (PVDF) films to convert turbulence induced oscillations into electrical energy. It is intended to be used in standard water pipes with diameters between 0.5 and 1 inch. The working principle of the harvester uses a ring shaped bluff body inside the pipe to induce pressure fluctuations. Additionally the bluff body houses electronic components such as storage, circuitry and RF-unit. Placing the piezoelectric films downstream of that bluff body causes their oscillation which generates electrical charge. The PVDF-film is placed as a multilayered wrap fixed to the pipe wall leaving the top part to oscillate freely inside the flow. The warp, which allows for a larger active, consists of two layers of 30µm thick and 12mm wide PVDF layered alternately with two centered 6µm thick and 8mm wide aluminum foil electrodes. The length of the layers depends on the number of windings and is part of the investigation. Sealing the harvester against liquid penetration is achieved by wrapping it in a ring-shaped LDPE-film and welding the open ends. The fabrication of the PVDF-wraps is done by hand. After validating the working principle using a wind tunnel, experiments have been conducted in water, placing the harvester inside a 1 inch pipe at water velocities of 0.74m/s. To find a suitable placement of the wrap inside the pipe, two forms of fixation were compared regarding their power output. Further investigations regarding the number of windings required for efficient transduction were made. Best results were achieved using a wrap with 3 windings of the active layers which delivers a constant power output of 0.53µW at a 2.3MΩ load and an effective voltage of 1.1V. Considering the extremely low power requirements of sensor applications, these initial results are promising. For further investigations and optimization, machine designs are currently being developed to automate the fabrication and decrease tolerance of the prototypes.Keywords: maintenance-free sensors, measurements at point of use, piezoelectric flow harvesting, universal micro generator, wireless metering systems
Procedia PDF Downloads 193348 Color Conversion Films with CuInS2/ZnS Quantum Dots Embedded Polystyrene Nanofibers by Electrospinning Process
Authors: Wonkyung Na, Namhun Kim, Heeyeop Chae
Abstract:
Quantum dots (QDs) are getting attentions due to their excellent optical properties in display, solar cell, biomolecule detection and lighting applications. Energy band gap can be easilty controlled by controlling their size and QDs are proper to apply in light-emitting-diode(LED) and lighting application, especially. Typically cadmium (Cd) containing QDs show a narrow photoluminescence (PL) spectrum and high quantum yield. However, Cd is classified as a hazardous materials and the use of Cd is being tightly regulated under 100ppm level in many countries.InP and CuInS2 (CIS) are being investigated as Cd-free QD materials and it is recently demonstrated that the performance of those Cd-free QDs is comparable to their Cd-based rivals.Due to a broad emission spectrum, CuInS2 QDs are also proper to be applied to white LED.4 For the lighting applications, the QD should be made in forms of color conversion films. Various film processes are reported with QDs in polymer matrixes. In this work, we synthesized the CuInS2 (CIS) QDs and QD embedded polystyrene color conversion films were fabricated for white color emission with electro-spinning process. As a result, blue light from blue LED is converted to white light with high color rendering index (CRI) of 72 by the color conversion films.Keywords: CuInS2/ZnS, electro-spinning, color conversion films, white light emitting diodes
Procedia PDF Downloads 813347 Influence of Sewage Sludge on Agricultural Land Quality and Crop
Authors: Catalina Iticescu, Lucian P. Georgescu, Mihaela Timofti, Gabriel Murariu
Abstract:
Since the accumulation of large quantities of sewage sludge is producing serious environmental problems, numerous environmental specialists are looking for solutions to solve this problem. The sewage sludge obtained by treatment of municipal wastewater may be used as fertiliser on agricultural soils because such sludge contains large amounts of nitrogen, phosphorus and organic matter. In many countries, sewage sludge is used instead of chemical fertilizers in agriculture, this being the most feasible method to reduce the increasingly larger quantities of sludge. The use of sewage sludge on agricultural soils is allowed only with a strict monitoring of their physical and chemical parameters, because heavy metals exist in varying amounts in sewage sludge. Exceeding maximum permitted quantities of harmful substances may lead to pollution of agricultural soil and may cause their removal aside because the plants may take up the heavy metals existing in soil and these metals will most probably be found in humans and animals through food. The sewage sludge analyzed for the present paper was extracted from the Wastewater Treatment Station (WWTP) Galati, Romania. The physico-chemical parameters determined were: pH (upH), total organic carbon (TOC) (mg L⁻¹), N-total (mg L⁻¹), P-total (mg L⁻¹), N-NH₄ (mg L⁻¹), N-NO₂ (mg L⁻¹), N-NO₃ (mg L⁻¹), Fe-total (mg L⁻¹), Cr-total (mg L⁻¹), Cu (mg L⁻¹), Zn (mg L⁻¹), Cd (mg L⁻¹), Pb (mg L⁻¹), Ni (mg L⁻¹). The determination methods were electrometrical (pH, C, TSD) - with a portable HI 9828 HANNA electrodes committed multiparameter and spectrophotometric - with a Spectroquant NOVA 60 - Merck spectrophotometer and with specific Merck parameter kits. The tests made pointed out the fact that the sludge analysed is low heavy metal falling within the legal limits, the quantities of metals measured being much lower than the maximum allowed. The results of the tests made to determine the content of nutrients in the sewage sludge have shown that the existing nutrients may be used to increase the fertility of agricultural soils. Other tests were carried out on lands where sewage sludge was applied in order to establish the maximum quantity of sludge that may be used so as not to constitute a source of pollution. The tests were made on three plots: a first batch with no mud and no chemical fertilizers applied, a second batch on which only sewage sludge was applied, and a third batch on which small amounts of chemical fertilizers were applied in addition to sewage sludge. The results showed that the production increases when the soil is treated with sludge and small amounts of chemical fertilizers. Based on the results of the present research, a fertilization plan has been suggested. This plan should be reconsidered each year based on the crops planned, the yields proposed, the agrochemical indications, the sludge analysis, etc.Keywords: agricultural use, crops, physico–chemical parameters, sewage sludge
Procedia PDF Downloads 289346 Geochemical Evaluation Assessment of Groundwater in Selected Part of Benue State Southern, Nigeria
Authors: Moses Oghnennyoreme Eyankware, Christian Ogubuchi Ede
Abstract:
Groundwater is the principal source for various uses in this study area. The quality and availability of groundwater depend on rock formation within the study area. To effectively study the quality of groundwater, 24 groundwater samples were collected. The study was aimed at investigating the hydrogeochemistry of groundwater, and additionally its suitability for drinking and irrigation purposes. The following parameters were analyzed using the American Public Health Association standard method: pH, turbidity, Ec, TDS, Mg2+, SO42-, NO3¯, Cl-, HCO3¯, K+, Na2+ and Ca2+. Results obtained from Water Quality Index revealed that the groundwater sample fell within good water quality that implies that groundwater is considered fit for drinking purposes. Deduced results obtained from irrigation indices revealed that Permeability Index (PI), Soluble Sodium Percentage (SSP), Sodium Percentage (Na %), Sodium Absorption Ratio (SAR), Kelly Ratio (KR), Magnesium Hazard (MH) ranges from 0.00 to 0.01, 4.04 to 412.9, 0.63 to 257.7, 0.15 to 2.34, 0.09 to 2.57 and 6.84 to 84.55 respectively. Findings from Total hardness revealed that groundwater fell within soft, moderately hard and hard categories. Estimated results obtained from CSMR, RI and LSI showed that groundwater showed corrosion tendency, salinization influenced groundwater at certain sampling points and chloride and sulfate unlikely to interfere with natural formation film.Keywords: water, quality, suitability, anthropogenic, Nigeria
Procedia PDF Downloads 169345 Conformal Noble Metal High-Entropy Alloy Nanofilms by Atomic Layer Deposition for Enhanced Hydrogen Evolution Reaction/Oxygen Evolution Reaction Electrocatalysis Applications
Authors: Jing Lin, Zou Yiming, Goei Ronn, Li Yun, Amanda Ong Jiamin, Alfred Tok Iing Yoong
Abstract:
High-entropy alloy (HEA) coatings comprise multiple (five or more) principal elements that give superior mechanical, electrical, and thermal properties. However, the current synthesis methods of HEA coating still face huge challenges in facile and controllable preparation, as well as conformal integration, which seriously restricts their potential applications. Herein, we report a controllable synthesis of conformal quinary HEA coating consisting of noble metals (Rh, Ru, Ir, Pt, and Pd) by using the atomic layer deposition (ALD) with a post-annealing approach. This approach realizes low temperature (below 200 °C), precise control (nanoscale), and conformal synthesis (over complex substrates) of HEA coating. Furthermore, the resulting quinary HEA coating shows promising potential as a platform for catalysis, exhibiting substantially enhanced electrocatalytic hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) performances as compared to other noble metal-based structures such as single metal coating or multi-layered metal composites.Keywords: high-entropy alloy, thin-film, catalysis, water splitting, atomic layer deposition
Procedia PDF Downloads 124344 Influence of Resin Finishes on Properties of Khadi Fabric
Authors: Shivi Rastogi, Suman Pant
Abstract:
Khadi is an Indian fabric and also known by another name “Khaddar”. During pre-independence era, the movement of khadi manufacturing gained momentum. Over the years, khadi fabrics that were generally considered as the “second skin” of the Swadesh revolutionists changed its uniqueness. It underwent a metamorphosis from that of a patriot’s fabric, and a farmer’s apparel, to become a “fashion fabric”. Drape of garment is governed by draping quality of fabric used. Drape is an essential parameter to decide both appearance and handle of fabric. It is also a secondary determinant of fabric mechanical properties as influenced by the low stress properties, like bending length, formability, tensile and shear properties and compressibility of the fabric. In finishing, fabric is treated to add something to coat the fabric or fiber and thereby temporarily or permanently fix. Film forming agents such as thermoplastic and thermosetting resins and other surface deposits alter hand. In this study, resins were used to modify fabric hand. Three types of resins have been applied on the khadi fabric at three concentration. The effect of these finishes on drapeability, crease recovery, stiffness, tearing strength and smoothness of khadi fabrics were assessed. Silicone gave good results in imparting properties specially drape, smoothness and softness and hand of cotton and khadi fabric. KES result also showed that silicone treated samples enhanced THV rating amongst all treated samples when compared to the control fabric.Keywords: crease recovery, drapeability, KES, silicone, THV
Procedia PDF Downloads 228343 Optical Characterization and Surface Morphology of SnO2 Thin Films Prepared by Spin Coating Technique
Authors: J. O. Ajayi, S. S. Oluyamo, D. B. Agunbiade
Abstract:
In this work, tin oxide thin films (SnO2) were prepared using the spin coating technique. The effects of precursor concentration on the thin film properties were investigated. Tin oxide was synthesized from anhydrous Tin (II) Chloride (SnCl2) dispersed in Methanol and Acetic acid. The metallic oxide (SnO2) films deposited were characterized using the UV Spectrophotometer and the Scanning Electron Microscope (SEM). From the absorption spectra, absorption increases with decrease in precursor concentration. Absorbance in the VIS region is lower than 0 % at higher concentration. The optical transmission spectrum shows that transmission increases as the concentration of precursor decreases and the maximum transmission in visible region is about 90% for films prepared with 0.2 M. Also, there is increase in the reflectance of thin films as concentration of precursor increases. The films have high transparency (more than 85%) and low reflectance (less than 40%) in the VIS region. Investigation showed that the direct band gap value increased from 3.79eV, to 3.82eV as the precursor concentration decreased from 0.6 M to 0.2 M. Average direct bandgap energy for all the tin oxide films was estimated to be 3.80eV. The effect of precursor concentration was directly observed in crystal outgrowth and surface particle densification. They were found to increase proportionately with higher concentration.Keywords: anhydrous TIN (II) chloride, densification, NIS- VIS region, spin coating technique
Procedia PDF Downloads 261342 Storyboarding for VR: Towards A Conceptual Framework for Transitioning Traditional Storyboarded Narrative Sequences to Immersive 3D VR Experiences
Authors: Sorin Oancea
Abstract:
More than half a century after Ivan Sutherland’s seminal essay, ‘The Ultimate Display’ (1965), 3D Virtual Reality is still an emergent and exploratory medium in terms of its narrative potential, production methodology, and market penetration. Traditionally positioned in front of the screen/canvas as a ‘window-on-the-world’, the storyboarder and animation director transcend the medium and its narrative reality entirely while designing a linear cinematic sequence. This paper proposes a gradual transition from the traditional linear sequence design process based on a transcendent position of the storyboarder and animation director to an increasingly immersed one characterized by a sense of unmediated presence and immanence. Employing a quaitative analysis of the current exploratory storyboarding processes for 3D VR, this research uses a practice-based methodology based on producing a short-form 3D VR narrative experience to derive its findings. The original contribution to knowledge is charting an empirically derived conceptual framework for VR storyboarding and animation directing, with the documented reflective and reflexive process as a map for directorial transitioning between converging mediums by articulating the new VR lexical categories and expounding links to allied performative arts, such as film and theatre.Keywords: storyboarding, immersive, virtual reality, transitioning
Procedia PDF Downloads 101341 Optical Bands Splitting in Tm₃Fe₅O₁₂ Thin Films
Authors: R. Vidyasagar, G. L. S. Vilela, B. M. Guiraldelli, A. B. Henriques, J. Moodera
Abstract:
Nano-scaled magnetic systems that can have both magnetic and optical transitions controlled and manipulated by external means have received enormous research attention for their potential applications in magneto-optics and spintronic devices. Among several ferrimagnetic insulators, the Tm₃Fe₅O₁₂ (TmIG) has become a prototype material displaying huge perpendicular magnetic anisotropy. Nevertheless, the optical properties of nano-scale TnIG films have not yet been investigated. We report the observation of giant splitting in the optical transitions of high-quality thin films of Tm₃Fe₅O₁₂ (TmIG) grown by rf sputtering on gadolinium gallium garnet substrates (GGG-111) substrate. The optical absorbance profiles measured with optical absorption spectroscopy show a dual optical transition in visible frequency regimes attributed to the transitions of electrons from the O-2p valence band to the Fe-3d conduction band and from the O-2p valence band to the Fe-2p⁵3d⁶ excitonic states at the Γ-symmetric point of the TmIG Brillouin zone. When the thickness of the film is reduced from 120 nm to 7.5 nm, the 1st optical transition energy shifted from 2.98 to 3.11 eV ( ~130 meV), and the 2nd transition energy shifted from 2.62 to 2.56 eV (~ 60 meV). The giant band splitting of both transitions can be attributed to the population of excited states associated with the atomic modification pertaining to the compressive or tensile strains.Keywords: optical transitions, thin films, ferrimagnetic insulator, strains
Procedia PDF Downloads 49