Search results for: African film
1071 Newly Developed Epoxy-Polyol and Epoxy- Polyurethane from Renewable Resources
Authors: Akintayo Emmanuel Temitope, Akintayo Cecilia Olufunke, Ziegler Thomas
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Bio-polyols are important components in polyurethane industries. The preliminary studies into the synthesis of bio-polyol products (epoxy-polyol and epoxyl-polyurethanes) from Jatropha curcas were investigated. The reactions were followed by both infrared and nuclear magnetic resonance. Physico-chemical characterisation of the samples for iodine value (IV), acid value (AV), saponification value (SV) and hydroxyl value (HV) were carried out. Thermal transitions of the products were studied by heating 5 mg of the sample from 20ºC to 800ºC and then cooling down to -500ºC on a differential scanning calorimeter (DSC). The preparation of epoxylpolyol and polyurethane from Jatropha curcas oil was smooth and efficient. Results of film and solubility properties revealed that coatings of Jatropha curcas epoxy-polyurethanes performed better with increased loading of toluylene 2, 4-diisocyanate (TDI) up to 2 wt% while their solvent resistance decreased beyond a TDI loading of 1.2 wt%. DSC analysis shows the epoxy-polyurethane to be less stable compared to the epoxy-polyol.Keywords: synthesis, epoxy-polyol, epoxy-polyurethane, jatropha curcas oil
Procedia PDF Downloads 4051070 Improvement of Chemical Demulsifier Performance Using Silica Nanoparticles
Authors: G. E. Gandomkar, E. Bekhradinassab, S. Sabbaghi, M. M. Zerafat
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The reduction of water content in crude oil emulsions reduces pipeline corrosion potential and increases the productivity. Chemical emulsification of crude oil emulsions is one of the methods available to reduce the water content. Presence of demulsifier causes the film layer between the crude oil emulsion and water droplets to become unstable leading to the acceleration of water coalescence. This research has been performed to study the improvement performance of a chemical demulsifier by silica nanoparticles. The silica nano-particles have been synthesized by sol-gel technique and precipitation using poly vinyl alcohol (PVA) and poly ethylene glycol (PEG) as surfactants and then nano-particles are added to the demulsifier. The silica nanoparticles were characterized by Particle Size Analyzer (PSA) and SEM. Upon the addition of nanoparticles, bottle tests have been carried out to separate and measure the water content. The results show that silica nano-particles increase the demulsifier efficiency by about 40%.Keywords: demulsifier, dehydration, silicon dioxide, nanoparticle
Procedia PDF Downloads 3951069 A South African Perspective on Palestine and the Motivation for a One-State Solution
Authors: Farhin Delawala
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In the context of Palestine and the broader Middle East, this study delves into the Apartheid regime in Palestine, the country under occupation, and the intricate ties between the United States of America (USA) and the settler colony of ‘Israel’. The paper provides an explanation of the colonisation of Palestine as well as the forms of Apartheid. Moreover, it explains the provisions of United Nations (UN) international laws and how they have been broken by the settler colony of ‘Israel’. The paper contends that the US, motivated by its security interests in the region, has strategically influenced the political instability in the Middle East and the illegal occupation of Palestine. Furthermore, this paper proposes an alternative path of a one-state solution to foster a more peaceful and stable society and advocates for the integration of the Palestinian population into the region, from Gaza and the West Bank, under equal citizen rights. Thereby, the ethno-theocratic nature of the settler colony as an ethno-theocratic state is dismantled.Keywords: apartheid, one-state solution, Palestine, political instability, settler colony
Procedia PDF Downloads 501068 Studying the Effect of Silicon Substrate Intrinsic Carrier Concentration on Performance of ZnO/Si Solar Cells
Authors: Syed Sadique Anwer Askari, Mukul Kumar Das
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Zinc Oxide (ZnO) solar cells have drawn great attention due to the enhanced efficiency and low-cost fabrication process. In this study, ZnO thin film is used as the active layer, hole blocking layer, antireflection coating (ARC) as well as transparent conductive oxide. To improve the conductivity of ZnO, top layer of ZnO is doped with aluminum, for top contact. Intrinsic carrier concentration of silicon substrate plays an important role in enhancing the power conversion efficiency (PCE) of ZnO/Si solar cell. With the increase of intrinsic carrier concentration PCE decreased due to increase in dark current in solar cell. At 80nm ZnO and 160µm Silicon substrate thickness, power conversion efficiency of 26.45% and 21.64% is achieved with intrinsic carrier concentration of 1x109/cm3, 1.4x1010/cm3 respectively.Keywords: hetero-junction solar cell, solar cell, substrate intrinsic carrier concentration, ZnO/Si
Procedia PDF Downloads 5871067 On the Difference between Cultural and Religious Identities
Authors: Mputu Ngandu Simon
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Culture and religion are two of the most significant markers of an individual or group's identity. Religion finds its expression in a given culture, and culture is the costume in which a religion is dressed. In other words, there is a crucial relationship between religion and culture which should not be ignored. On the one hand, religion influences the way in which a culture is consumed. A person's consumption of a certain cultural practice is influenced by his/her religious identity. On the other hand, cultural identity plays an important role in how a religion is practiced by its adherents. Some cultural practices become more credible when interpreted in religious terms just as religious doctrines and dogmas need cultural interpretation to be understood by a given people in a given context. This relationship goes so deep that sometimes the boundaries between culture and religion become blurred, and people end up mixing religion and culture. In some cases, the two are considered to be one and the same thing. However, despite this apparent sameness, religion and culture are two distinct aspects of identity, and they should always be considered as such. One results from knowledge, while the other has beliefs as its foundation. This essay explores the difference between cultural and religious identity by drawing from existing literature on this topic as a whole before applying that knowledge to two specific case studies: Christianity and Islam in some African and Asian countries.Keywords: culture, religion, identity, knowledge, belief
Procedia PDF Downloads 1761066 Ion Beam Sputtering Deposition of Inorganic-Fluoropolymer Nano-Coatings for Real-Life Applications
Authors: M. Valentini, D. Melisi, M. A. Nitti, R A. Picca, M. C. Sportelli, E. Bonerba, G. Casamassima, N. Cioffi, L. Sabbatini, G. Tantillo, A. Valentini
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In recent years antimicrobial coatings are receiving increasing attention due to their high demand in medical applications as well as in healthcare and hygiene. Research and technology are constantly involved to develop advanced finishing which can provide bacteriostatic growth without compromising the other typical properties of a textile as durability and non-toxicity, just to cite a few. Here we report on the antimicrobial coatings obtained, at room temperature and without the use of solvents, by means of the ion beam co-sputtering technique of an Ag target and a polytetrafluoroethylene one. In particular, such method allows to conjugate the well-known antimicrobial action of silver with the anti-stain and water-repellent properties of the fluoropolymer. Moreover, different Ag nanoparticle loadings (φ) were prepared by tuning the material deposition conditions achieving a fine control on film thickness and their antimicrobial/anti-stain properties.Keywords: antimicrobial, ion beam sputtering, nanocoatings, anti-stain
Procedia PDF Downloads 3821065 South African Students' Statistical Literacy in the Conceptual Understanding about Measures of Central Tendency after Completing Their High School Studies
Authors: Lukanda Kalobo
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In South Africa, the High School Mathematics Curriculum provides teachers with specific aims and skills to be developed which involves the understanding about the measures of central tendency. The exploration begins with the definitions of statistical literacy, measurement of central tendency and a discussion on why statistical literacy is essential today. It furthermore discusses the statistical literacy basics involved in understanding the concepts of measures of central tendency. The statistical literacy test on the measures of central tendency, was used to collect data which was administered to 78 first year students direct from high schools. The results indicated that students seemed to have forgotten about the statistical literacy in understanding the concepts of measure of central tendency after completing their high school study. The authors present inferences regarding the alignment between statistical literacy and the understanding of the concepts about the measures of central tendency, leading to the conclusion that there is a need to provide in-service and pre-service training.Keywords: conceptual understanding, mean, median, mode, statistical literacy
Procedia PDF Downloads 2911064 The Reintegration of the Past as Self-Realisation
Authors: Haotian Wu
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This article examines the figure Zhao Tao in Jia Zhangke’s films in light of Carl Jung’s psychoanalytical theory. Zhao is a recurring aesthetic trope in Jia’s films, and the characters she plays often have an intimate relationship with the past. Nevertheless, this relationship has not been systematically investigated, especially its symbolism of the typical relationship between the past and the self in post-social China. To fill this research gap, the article will explore how Zhao’s characters discover, preserve, and adapt the past in I Wish I knew (2010), Mountains May Depart (2015), and Ash Is Purest White (2018). Through a Jungian lens, these three levels of engagement with the past will be demonstrated as corresponding with Jung’s psychoanalytical theory of self-realisation, which entails the confrontation with the shadow, the embodiment of the archetype, and individuation. Thus, by articulating a film-philosophy dialogue between Jia and Jung, this article will develop a new philosophy of self-realisation based on the symbolism of Zhao. Through the reintegration of the past, the individuals can overcome the fragmentation of temporality and selfhood in the postmodern world and achieve self-realisation.Keywords: Jia Zhangke, Jung, psychoanalysis, self-realisation
Procedia PDF Downloads 5801063 Exploring Cardiovascular and Behavioral Impacts of Aerobic Exercise: A Moroccan Perspective
Authors: Ahmed Boujdad
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Morocco, a North African nation known for its rich culture and diverse landscapes, is facing evolving challenges related to cardiovascular health and behavioral well-being. Against this backdrop, the paper aims to spotlight the insights emerging from Moroccan research into the impacts of aerobic exercise on cardiovascular physiology and psychological outcomes. Presentations will encompass a range of topics, including exercise-induced adaptations in heart function, blood pressure management, and vascular health specific to the Moroccan population. A notable focus of the paper will be the examination of how aerobic exercise intertwines with Moroccan behavioral patterns and sociocultural factors. The research will delve into the links between regular exercise and its potential to alleviate stress, anxiety, and depression in the Moroccan context. This exploration extends to the role of exercise in bolstering the cultural fabric of Moroccan society, enhancing community engagement, and promoting a sense of well-being.Keywords: event-related potential, executive function, physical activity, kinesiology
Procedia PDF Downloads 751062 Effects of Dimensional Sizes of Mould on the Volumetric Shrinkage Strain of Lateric Soil
Authors: John E. Sani, Moses George
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The paper presents the result of a laboratory study carried out on lateritic soil to determine the effects of dimensional size on the volumetric shrinkage strain (VSS) using three mould sizes i.e. split former mould, proctor mould and California bearing ratio (CBR) mould at three energy levels; British standard light (BSL), West African standard (WAS) and British standard heavy (BSH) respectively. Compactions were done at different molding water content of -2 % to +6 % optimum moisture content (OMC). At -2% to +2% molding water content for the split former mould the volumetric shrinkage strain met the requirement of not more than 4% while at +4% and +6% only the WAS and BSH met the requirement. The proctor mould and the CBR mould on the other hand gave a lower value of volumetric shrinkage strain in all compactive effort and the values are lower than the 4% safe VSS value.Keywords: lateritic soil, volumetric shrinkage strain, molding water content, compactive effort
Procedia PDF Downloads 5181061 Middle School as a Developmental Context for Emergent Citizenship
Authors: Casta Guillaume, Robert Jagers, Deborah Rivas-Drake
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Civically engaged youth are critical to maintaining and/or improving the functioning of local, national and global communities and their institutions. The present study investigated how school climate and academic beliefs (academic self-efficacy and school belonging) may inform emergent civic behaviors (emergent citizenship) among self-identified middle school youth of color (African American, Multiracial or Mixed, Latino, Asian American or Pacific Islander, Native American, and other). Study aims: 1) Understand whether and how school climate is associated with civic engagement behaviors, directly and indirectly, by fostering a positive sense of connection to the school and/or engendering feelings of self-efficacy in the academic domain. Accordingly, we examined 2) The association of youths’ sense of school connection and academic self-efficacy with their personally responsible and participatory civic behaviors in school and community contexts—both concurrently and longitudinally. Data from two subsamples of a larger study of social/emotional development among middle school students were used for longitudinal and cross sectional analysis. The cross-sectional sample included 324 6th-8th grade students, of which 43% identified as African American, 20% identified as Multiracial or Mixed, 18% identified as Latino, 12% identified as Asian American or Pacific Islander, 6% identified as Other, and 1% identified as Native American. The age of the sample ranged from 11 – 15 (M = 12.33, SD = .97). For the longitudinal test of our mediation model, we drew on data from the 6th and 7th grade cohorts only (n =232); the ethnic and racial diversity of this longitudinal subsample was virtually identical to that of the cross-sectional sample. For both the cross-sectional and longitudinal analyses, full information maximum likelihood was used to deal with missing data. Fit indices were inspected to determine if they met the recommended thresholds of RMSEA below .05 and CFI and TLI values of at least .90. To determine if particular mediation pathways were significant, the bias-corrected bootstrap confidence intervals for each indirect pathway were inspected. Fit indices for the latent variable mediation model using the cross-sectional data suggest that the hypothesized model fit the observed data well (CFI = .93; TLI =. 92; RMSEA = .05, 90% CI = [.04, .06]). In the model, students’ perceptions of school climate were significantly and positively associated with greater feelings of school connectedness, which were in turn significantly and positively associated with civic engagement. In addition, school climate was significantly and positively associated with greater academic self-efficacy, but academic self-efficacy was not significantly associated with civic engagement. Tests of mediation indicated there was one significant indirect pathway between school climate and civic engagement behavior. There was an indirect association between school climate and civic engagement via its association with sense of school connectedness, indirect association estimate = .17 [95% CI: .08, .32]. The aforementioned indirect association via school connectedness accounted for 50% (.17/.34) of the total effect. Partial support was found for the prediction that students’ perceptions of a positive school climate are linked to civic engagement in part through their role in students’ sense of connection to school.Keywords: civic engagement, early adolescence, school climate, school belonging, developmental niche
Procedia PDF Downloads 3611060 Impact of Fly Ash-Based Geopolymer Modification on the High-Temperature Properties of Bitumen
Authors: Burak Yigit Katanalp, Murat Tastan, Perviz Ahmedzade, çIgdem Canbay Turkyilmaz, Emrah Turkyilmaz
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This study evaluated the mechanical and rheological performance of fly ash-based geopolymer at high temperatures. A series of laboratory tests were conducted on neat bitumen and three modified bitumen samples, which incorporated fly ash-based geopolymer at various percentages. Low-calcium fly ash was used as the alumina-silica source. The dynamic shear rheometer and rotational viscometer were employed to determine high-temperature properties, while conventional tests such as penetration and softening point were used to evaluate the physical properties of bitumen. The short-term aging resistance of the samples was assessed using the rolling thin film oven. The results show that geopolymer has a compromising effect on bitumen properties, with improved stiffness, enhanced mechanical strength, and increased thermal susceptibility of the asphalt binder.Keywords: bitumen, geopolymer, modification, dynamic mechanical analysis
Procedia PDF Downloads 831059 An Introduction to the Radiation-Thrust Based on Alpha Decay and Spontaneous Fission
Authors: Shiyi He, Yan Xia, Xiaoping Ouyang, Liang Chen, Zhongbing Zhang, Jinlu Ruan
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As the key system of the spacecraft, various propelling system have been developing rapidly, including ion thrust, laser thrust, solar sail and other micro-thrusters. However, there still are some shortages in these systems. The ion thruster requires the high-voltage or magnetic field to accelerate, resulting in extra system, heavy quantity and large volume. The laser thrust now is mostly ground-based and providing pulse thrust, restraint by the station distribution and the capacity of laser. The thrust direction of solar sail is limited to its relative position with the Sun, so it is hard to propel toward the Sun or adjust in the shadow.In this paper, a novel nuclear thruster based on alpha decay and spontaneous fission is proposed and the principle of this radiation-thrust with alpha particle has been expounded. Radioactive materials with different released energy, such as 210Po with 5.4MeV and 238Pu with 5.29MeV, attached to a metal film will provides various thrust among 0.02-5uN/cm2. With this repulsive force, radiation is able to be a power source. With the advantages of low system quantity, high accuracy and long active time, the radiation thrust is promising in the field of space debris removal, orbit control of nano-satellite array and deep space exploration. To do further study, a formula lead to the amplitude and direction of thrust by the released energy and decay coefficient is set up. With the initial formula, the alpha radiation elements with the half life period longer than a hundred days are calculated and listed. As the alpha particles emit continuously, the residual charge in metal film grows and affects the emitting energy distribution of alpha particles. With the residual charge or extra electromagnetic field, the emitting of alpha particles performs differently and is analyzed in this paper. Furthermore, three more complex situations are discussed. Radiation element generating alpha particles with several energies in different intensity, mixture of various radiation elements, and cascaded alpha decay are studied respectively. In combined way, it is more efficient and flexible to adjust the thrust amplitude. The propelling model of the spontaneous fission is similar with the one of alpha decay, which has a more complex angular distribution. A new quasi-sphere space propelling system based on the radiation-thrust has been introduced, as well as the collecting and processing system of excess charge and reaction heat. The energy and spatial angular distribution of emitting alpha particles on unit area and certain propelling system have been studied. As the alpha particles are easily losing energy and self-absorb, the distribution is not the simple stacking of each nuclide. With the change of the amplitude and angel of radiation-thrust, orbital variation strategy on space debris removal is shown and optimized.Keywords: alpha decay, angular distribution, emitting energy, orbital variation, radiation-thruster
Procedia PDF Downloads 1941058 Defence Diplomacy and Collective Security in Africa: Case of Rwanda Defence Forces
Authors: Emmanuel Mugiraneza
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Rwanda uses defence diplomacy to pursue international collective security through different mechanisms. This paper shows that with an intent of promoting international collective security, Rwanda has constituted its defense diplomacy policy in three standpoints. First, Rwanda has formed strategic cooperation alliances with state actors, regional and international Organizations that enables her to participate in and promote international collective peace, security and cooperation. Secondary, Rwanda uses defence diplomacy to foster cooperation in to pre-empt, minimize and neutralize potential triggers that would lead to the outbreak of international conflict. Thirdly, Rwanda implements defence diplomacy policy strategy through internationally recognized operational and tactical standards while dispelling hostilities, assisting the friendly nation’s forces and or building and maintaining public confidence and trust in the areas where Rwanda Defence Force deploys for peacekeeping missions in Sudan, South Sudan, Central African Republic and Mozambique for a counterterrorism mission.Keywords: defence diplomacy, collective security, Rwanda, Peacekeeping
Procedia PDF Downloads 1101057 Comparison of Tribological Properties of TiO₂, ZrO₂ and TiO₂–ZrO₂ Composite Films Prepared by Sol–Gel Method
Authors: O. Çomaklı, M. Yazıcı, T. Yetim, A. F. Yetim, A. Çelik
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In this study, TiO₂, ZrO₂, and TiO₂–ZrO₂ composite films were coated on Cp-Ti substrates by sol-gel method. Structures of uncoated and coated samples were investigated by X-ray diffraction and SEM. XRD data identified anatase phase in TiO₂ coated samples and tetragonal zirconia phase in ZrO₂ coated samples while both of anatase and tetragonal zirconia phases in TiO₂–ZrO₂ composite films. The mechanical and wear properties of samples were investigated using micro hardness, pin-on-disk tribotester, and 3D profilometer. The best wear resistance was obtained from TiO₂–ZrO₂ composite films. This can be attributed to their high surface hardness, low surface roughness and high thickness of the film.Keywords: sol-gel, TiO₂, ZrO₂, TiO₂–ZrO₂, composite films, wear
Procedia PDF Downloads 2531056 Tectono-Stratigraphic Architecture, Depositional Systems and Salt Tectonics to Strike-Slip Faulting in Kribi-Campo-Cameroon Atlantic Margin with an Unsupervised Machine Learning Approach (West African Margin)
Authors: Joseph Bertrand Iboum Kissaaka, Charles Fonyuy Ngum Tchioben, Paul Gustave Fowe Kwetche, Jeannette Ngo Elogan Ntem, Joseph Binyet Njebakal, Ribert Yvan Makosso-Tchapi, François Mvondo Owono, Marie Joseph Ntamak-Nida
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Located in the Gulf of Guinea, the Kribi-Campo sub-basin belongs to the Aptian salt basins along the West African Margin. In this paper, we investigated the tectono-stratigraphic architecture of the basin, focusing on the role of salt tectonics and strike-slip faults along the Kribi Fracture Zone with implications for reservoir prediction. Using 2D seismic data and well data interpreted through sequence stratigraphy with integrated seismic attributes analysis with Python Programming and unsupervised Machine Learning, at least six second-order sequences, indicating three main stages of tectono-stratigraphic evolution, were determined: pre-salt syn-rift, post-salt rift climax and post-rift stages. The pre-salt syn-rift stage with KTS1 tectonosequence (Barremian-Aptian) reveals a transform rifting along NE-SW transfer faults associated with N-S to NNE-SSW syn-rift longitudinal faults bounding a NW-SE half-graben filled with alluvial to lacustrine-fan delta deposits. The post-salt rift-climax stage (Lower to Upper Cretaceous) includes two second-order tectonosequences (KTS2 and KTS3) associated with the salt tectonics and Campo High uplift. During the rift-climax stage, the growth of salt diapirs developed syncline withdrawal basins filled by early forced regression, mid transgressive and late normal regressive systems tracts. The early rift climax underlines some fine-grained hangingwall fans or delta deposits and coarse-grained fans from the footwall of fault scarps. The post-rift stage (Paleogene to Neogene) contains at least three main tectonosequences KTS4, KTS5 and KTS6-7. The first one developed some turbiditic lobe complexes considered as mass transport complexes and feeder channel-lobe complexes cutting the unstable shelf edge of the Campo High. The last two developed submarine Channel Complexes associated with lobes towards the southern part and braided delta to tidal channels towards the northern part of the Kribi-Campo sub-basin. The reservoir distribution in the Kribi-Campo sub-basin reveals some channels, fan lobes reservoirs and stacked channels reaching up to the polygonal fault systems.Keywords: tectono-stratigraphic architecture, Kribi-Campo sub-basin, machine learning, pre-salt sequences, post-salt sequences
Procedia PDF Downloads 381055 Polarization Dependent Flexible GaN Film Nanogenerators and Electroluminescence Properties
Authors: Jeong Min Baik
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We present that the electroluminescence (EL) properties and electrical output power of flexible N-face p-type GaN thin films can be tuned by strain-induced piezo-potential generated across the metal-semiconductor-metal structures. Under different staining conditions (convex and concave bending modes), the transport properties of the GaN films can be changed due to the spontaneous polarization of the films. The I-V characteristics with the bending modes show that the convex bending can increase the current across the films by the decrease in the barrier height at the metal-semiconductor contact, increasing the EL intensity of the P-N junction. At convex bending, it is also shown that the flexible p-type GaN films can generate an output voltage of up to 1.0 V, while at concave bending, 0.4 V. The change of the band bending with the crystal polarity of GaN films was investigated using high-resolution photoemission spectroscopy. This study has great significance on the practical applications of GaN in optoelectronic devices and nanogenerators under a working environment.Keywords: GaN, flexible, laser lift-off, nanogenerator
Procedia PDF Downloads 4091054 Magnetoelectric Coupling in Hetero-Structured Nano-Composite of BST-BLFM Films
Authors: Navneet Dabra, Jasbir S. HUndal
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Hetero-structured nano-composite thin film of Ba0.5Sr0.5TiO3/Bi0.9La0.1Fe0.9Mn0.1O3 (BST/BLFM) has been prepared by chemical solution deposition method with various BST to BLFM thickness ratios. These films have been deposited over on p-type Si (100) substrate. These samples exhibited low leakage current, large grain size and uniform distribution of particles. The maximum remanent polarization (Pr) was achieved in the heterostructures with thickness ratio of 2.65. The dielectric tenability, electric hysteresis (P-E), ME coupling coefficient, magnetic hysteresis (M-H), ferromagnetic exchange interaction and magnetoelectric measurements were carried out. Field Emission Scanning Electron Microscopy has been employed to investigate the surface morphology of these heterostructured nano-composite films.Keywords: magnetoelectric, Schottky emission, interface coupling, dielectric tenability, electric hysteresis (P-E), ME coupling coefficient, magnetic hysteresis (M-H)
Procedia PDF Downloads 4201053 Silicon Surface Treatment Effect on the Structural, Optical, and Optoelectronic Properties for Solar Cell Applications
Authors: Lotfi Hedi Khezami, Mohamed Ben Rabha, N. Sboui, Mounir Gaidi, B. Bessais
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Metal-nano particle-assisted Chemical Etching is an extraordinary developed wet etching method of producing uniform semiconductor nano structure (nano wires) from patterned metallic film on crystalline silicon surface. The metal films facilitate the etching in HF and H2O2 solution and produce silicon nanowires (SiNWs). Creation of different SiNWs morphologies by changing the etching time and its effects on optical and opto electronic properties was investigated. Combination effect of formed SiNWs and stain etching treatment in acid (HF/HNO3/H2O) solution on the surface morphology of Si wafers as well as on the optical and opto electronic properties are presented in this paper.Keywords: stain etching, porous silicon, silicon nanowires, reflectivity, lifetime, solar cells
Procedia PDF Downloads 4401052 Effect of Temperature on the Structural and Optical Properties of ZnS Thin Films Obtained by Chemical Bath Deposition in Acidic Medium
Authors: Hamid Merzouk, Dajhida Talantikite, Amel Tounsi
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Thin films of ZnS have been deposited by chemical route into acidic medium. The deposition time fixed at 5 hours, and the bath temperature varied from 80° C to 95°C with an interval of 5°C. The X-ray diffraction (XRD), UV/ visible spectrophotometry, Fourier Transform Infrared spectroscopy (FTIR) have been used to study the effect of temperature on the structural and optical properties of ZnS thin films. The XRD spectrum of the ZnS layer obtained shows an increase of peaks intensity of ZnS with increasing bath temperature. The study of optical properties exhibit good transmittance (60–80% in the visible region), and the band gap energy of the ZnS thin film decrease from 3.71 eV to 3.64 eV while the refractive index (n) increase with increasing temperature bath. The FTIR analyze confirm our studies and show characteristics bands of vibration of Zn-S.Keywords: ZnS thin films, XRD spectra, optical gap, XRD
Procedia PDF Downloads 1421051 A Study on the Etching Characteristics of High aspect ratio Oxide Etching Using C4F6 Plasma in Inductively Coupled Plasma with Low Frequency Bias
Authors: ByungJun Woo
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In this study, high-aspect-ratio (HAR) oxide etching characteristics in inductively coupled plasma were investigated using low frequency (2 MHz) bias power with C4F6 gas. An experiment was conducted using CF4/C4F6/He as the mixed gas. A 100 nm (etch area)/500 nm (mask area) line patterns were used, and the etch cross-section and etch selectivity of the amorphous carbon layer thin film were derived using a scanning electron microscope. Ion density was extracted using a double Langmuir probe, and CFx and F neutral species were observed via optical emission spectroscopy. Based on these results, the possibility for HAR oxide etching using C4F6 gas chemistry was suggested in this work. These etching results also indicate that the use of C4F6 gas can significantly contribute to the development of next-generation HAR oxide etching.Keywords: plasma, etching, C4F6, high aspect ratio, inductively coupled plasma
Procedia PDF Downloads 601050 Production and Mechanical Properties of Alkali–Activated Inorganic Binders Made from Wastes Solids
Authors: Sonia Vanessa Campos Moreira
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The aim of this research is the production and mechanical properties of Alkali-Activated Inorganic Binders (AAIB) made from The Basic Oxygen Furnace Slag (BOF Slag) and Thin Film Transistor Liquid Crystal Display (TFT-LCD), glass powder (waste and industrial by-products). Many factors have an influence on the production of AAIB like the glass powder finesses, the alkaline equivalent content (AE %), water binder ratios (w/b ratios) and the differences curing process. The findings show different behavior in the AAIB related to the factors mentioned, the best results are given with a glass powder fineness of 4,500 cm²/g, w/b=0.30, a curing temperature of 70 ℃, curing duration of 4 days and an aging duration of 14 days results in the highest compressive strength of 18.51 MPa.Keywords: alkaline activators, BOF slag, glass powder fineness, TFT-LCD, w/b ratios
Procedia PDF Downloads 1531049 Mergers and Acquisitions in the Banking Sector: The West African Experience
Authors: Sunday Odunaiya
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The statistics of banks in operation in this current dispensation compared to some decades ago has brought about a lot of changes on the face of the financial system. The demand of customers, technological advancement, and government policies among others has therefore generated a lot of heat for financial sector’s growth, sustenance and survival. This paper discusses mergers and acquisitions (M&A) in banking sector using West Africa as a yardstick of evaluation. It explains rigorously the conditions that warrant mergers and acquisitions in the banking sector, its effect, and how to ensure mergers and acquisitions effectiveness in the banking sector. The conceptual and empirical review of the relevant literature were done systematically while value-increasing and value-decreasing theories were used to substantiate the discourse. Findings of this paper show that mergers and acquisitions is a practical and conscious activity in Nigeria, Ghana and Ivory Coast from earliest time till date with tremendous turnaround in the financial sector. It was found out that M&A is consensually arrived at by the targets and the acquirer on a value-based account. In other words, merger and acquisition is a deliberate decision reached by the management of such bank for a ‘just cause’.Keywords: acquisitions, merger, management, financial sector
Procedia PDF Downloads 2581048 New Approach to Encapsulated Clay/Wax Nanocomposites Inside Polystyrene Particles via Minemulstion Polymerization
Authors: Nagi Greesh
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This study highlights a new method to obtain multiphase composites particles containing hydrophobic (wax) and inorganic (clay) compounds. Multiphase polystyrene-clay-wax nanocomposites were successfully synthesized. Styrene monomer were polymerized in the presence of different wax-clay nanocomposites concentrations in miniemulsion. Wax-clay nanocomposites were firstly obtained through ultrasonic mixing at a temperature above the melting point of the wax at different clay loadings. The obtained wax-clay nanocomposites were then used as filler in the preparation of polystyrene-wax-clay nanocomposites via miniemulsion polymerization. The particles morphology of PS/wax-clay nanocomposites latexes was mainly determined by Transmission Electron Microscopy ( TEM) , core/shell morphology was clearly observed, with the encapsulation of most wax-clay nanocomposites inside the PS particles. On the other hand, the morphology of the PS/wax-clay nanocomposites (after film formation) ranged from exfoliated to intercalated structures, depending on the percentage of wax-clay nanocomposites loading. This strategy will allow the preparation materials with tailored properties for specific applications such as paint coatings and adhesives.Keywords: polymer-wax, paraffin wax, miniemulsion, core/shell, nanocomposites
Procedia PDF Downloads 831047 Gamma Irradiation Effects on the Crystal Structural and Transport Properties of Bi₂Te₃ Thin Films Grown by Thermal Evaporation
Authors: Shoroog Alraddadi
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In this study, the effect of gamma irradiation on the structural and transport properties of Bismuth Telluride (Bi₂Te₃) thin films was investigated. Bi₂Te₃ thin films with thicknesses varying from 100 nm to 500 nm were grown using thermal evaporation in vacuum 10⁻⁵ Torr. The films were irradiated by Gamma radiation with different doses (50, 200, and 500 kGy). The crystal structure of Bi₂Te₃ thin films was studied by XRD diffraction. It was showed that the degree of crystallinity of films increases as the doses increase. Furthermore, it was found that the electrical conductivity of Bi₂Te₃ increase as the doses increase. From these results, it can be concluding that the effect of radiation on the structural and transport properties was positive at the levels of irradiation used.Keywords: bismuth telluride, gamma irradiation, thin film, transport properties
Procedia PDF Downloads 1501046 Political Cinema: Rewriting The Malaysian Political History Through Documentary Films
Authors: Raja Rodziah Binti Raja Zainal Hassan
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The development of Malaysian political cinema is rapidly taking shape in the local film industry. The paper focuses on the production of independent political documentary by two Malaysian filmmakers, Amir Muhammad and Fahmi Reza. Revolutionary cinema can be understood by utilizing the Third Cinema Theory in order to analyse the meaning and its impact on the audience. The issue surrounding the political cinema in Malaysia is the question of national identity. The implementation of racial or ethnic based politics has resulted in hostility within Malaysia’s multiracial society. Amir Muhammad and Fahmi Reza revisit the Malaysian political history through their films in order to understand the reasons behind the hostility and conflict.Keywords: Political cinema, third cinema theory, revolutionary cinema, national identity, racial or ethnic politics
Procedia PDF Downloads 4221045 Study of Low Loading Heavier Phase in Horizontal Oil-Water Liquid-Liquid Pipe Flow
Authors: Aminu J. A. Koguna, Aliyu M. Aliyu, Olawale T. Fajemidupe, Yahaya D. Baba
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Production fluids are transported from the platform to tankers or process facilities through transfer pipelines. Water being one of the heavier phases tends to settle at the bottom of pipelines especially at low flow velocities and this has adverse consequences for pipeline integrity. On restart after a shutdown this could result in corrosion and issues for process equipment, thus the need to have the heavier liquid dispersed into the flowing lighter fluid. This study looked at the flow regime of low water cut and low flow velocity oil and water flow using conductive film thickness probes in a large diameter 4-inch pipe to obtain oil and water interface height and the interface structural velocity. A wide range of 0.1–1.0 m/s oil and water mixture velocities was investigated for 0.5–5% water cut. Two fluid model predictions were used to compare with the experimental results.Keywords: interface height, liquid, velocity, flow regime, dispersed, water cut
Procedia PDF Downloads 3801044 Energy Trends in Rural South Africa: A Case Study of the Mnweni Rural Community in the Province of Kwazulu-Natal
Authors: Noel Chellan
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Energy is the life-blood of development. All human societies have been and still are dependent on energy – some societies more than others. With regard to energy in South Africa, previous policies of the apartheid regime neglected the energy needs of poor black communities in general – and rural communities in particular. Since South Africa’s first democratic elections in 1994 – whilst millions of South African households have received electricity from the national electricity grid, there are still many rural communities that are still experiencing challenges in relation to both electricity deprivation as well as provision. This paper looks at the energy-mix of the Mnweni rural community in South Africa and argues that understanding energy is key to understanding the nature and forms of development of any community or country, for that matter. The paper engages with the energy trends in the rural community of Mnweni from the days of apartheid until 2021. It also looks at agricultural practises from an energy perspective. Such an energy perspective will enable one to assess the pace and scale of development in rural Mnweni.Keywords: rural, energy, development, apartheid
Procedia PDF Downloads 2331043 Assessment of the Relationship between Energy Price Dynamics and Green Growth in the Sub-Sharan Africa
Authors: Christopher I. Ifeacho, Adeleke Omolade
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The paper examines the relationship between energy price dynamics and green growth in Sub Sahara African Countries. The quest for adopting green energy in order to improve green growth that can engender sustainability and stability has received more attention from researchers in recent times. This study uses a panel autoregressive distributed lag approach to investigate this relationship. Findings from the result showed that energy price dynamics and exchange rates have more short-run significant impacts on green growth in individual countries rather than the pooled result. Furthermore, the long-run result confirmed that inflation and capital have a significant long-run relationship with green growth. The causality test result revealed the existence of a bi-directional relationship between green growth and energy price dynamics. The study recommends caution in a currency devaluation and improvement in renewable energy production in the Sub Sahara Africa in order to achieve sustainable green growth.Keywords: green growth, energy price dynamics, Sub Saharan Africa, relationship
Procedia PDF Downloads 881042 Number of Perovskite Layers and the Effect of Antisolvent on Perovskite Solar Cell Efficiency
Authors: Ece Çetin, İsmail Boz, Mehtap Şafak Boroğlu
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Energy is one of the most important components of production processes, economic activities, and daily life. Non-renewable energy sources cause serious environmental problems with the increase of greenhouse gases. Obtaining energy from renewable sources is also essential for sustainable economic growth. Solar energy is also an important renewable energy source with its unlimited and clean features. In this study, the effect of 1, 2, and 3 layers of perovskite film number and antisolvent dripping on perovskite based solar cell efficiency was investigated. The yield increased as the number of perovskite films increased. In addition, the yields obtained with the antisolvent dripped in the last 5 seconds are higher than the ones dropped in the last 17 seconds. The highest efficiency was obtained with 3 perovskite films, and antisolvent dropped in the last 5 seconds.Keywords: antisolvent, efficiency, perovskite, solar cell
Procedia PDF Downloads 102