Search results for: air bubbles size

Authors: B. G. Sheeparamatti, Prashant Hanasi, Vanita Abbigeri

Abstract:

The objective of this work is to carry out a critical comparison of different actuation mechanisms like electrostatic, thermal, piezoelectric, and magnetic with reference to a microcantilever. The relevant parameters like force generated, displacement are compared in actuation methods. With these results, they help in choosing the best actuation method for a particular application. In this study, Comsol/Multiphysics software is used. Modeling and simulation are done by considering the microcantilever of same dimensions as an actuator using all the above-mentioned actuation techniques. In addition to their small size, micro actuators consume very little power and are capable of accurate results. In this work, a comparison of actuation mechanisms is done to decide the efficient system in the micro domain.

Keywords: actuation techniques, microswitch, micro actuator, microsystems

Procedia PDF Downloads 408

Authors: Vishnu Pratap Singh Kirar

Abstract:

Wireless sensor network (WSN) is a network of many interconnected networked systems, they equipped with energy resources and they are used to detect other physical characteristics. On WSN, there are many researches are performed in past decades. WSN applicable in many security systems govern by military and in many civilian related applications. Thus, the security of WSN gets attention of researchers and gives an opportunity for many future aspects. Still, there are many other issues are related to deployment and overall coverage, scalability, size, energy efficiency, quality of service (QoS), computational power and many more. In this paper we discus about various applications and security related issue and requirements of WSN.

Keywords: wireless sensor network (WSN), wireless network attacks, wireless network security, security requirements

Procedia PDF Downloads 491

Authors: Adeline Meriaux, Claire Gaiani, Jennifer Burgain, Frantz Fournier, Lionel Muniglia, Jérémy Petit

Abstract:

Spray-drying process is widely used for the production of dairy powders for food and pharmaceuticals industries. It involves the atomization of a liquid feed into fine droplets, which are subsequently dried through contact with a hot air flow. The resulting powders permit transportation cost reduction and shelf life increase but can also exhibit various interesting functionalities (flowability, solubility, protein modification or acid gelation), depending on operating conditions and milk composition. Indeed, particles porosity, surface composition, lactose crystallization, protein denaturation, protein association or crust formation may change. Links between spray-drying conditions and physicochemical and functional properties of powders were investigated by a design of experiment methodology and analyzed by principal component analysis. Quadratic models were developed, and multicriteria optimization was carried out by the use of genetic algorithm. At the time of abstract submission, verification spray-drying trials are ongoing. To perform experiments, milk from dairy farm was collected, skimmed, froze and spray-dried at different air pressure (between 1 and 3 bars) and outlet temperature (between 75 and 95 °C). Dry matter, minerals content and proteins content were determined by standard method. Solubility index, absorption index and hygroscopicity were determined by method found in literature. Particle size distribution were obtained by laser diffraction granulometry. Location of the powder color in the Cielab color space and water activity were characterized by a colorimeter and an aw-value meter, respectively. Flow properties were characterized with FT4 powder rheometer; in particular, compressibility and shearing test were performed. Air pressure and outlet temperature are key factors that directly impact the drying kinetics and powder characteristics during spray-drying process. It was shown that the air pressure affects the particle size distribution by impacting the size of droplet exiting the nozzle. Moreover, small particles lead to more cohesive powder and less saturated color of powders. Higher outlet temperature results in lower moisture level particles which are less sticky and can explain a spray-drying yield increase and the higher cohesiveness; it also leads to particle with low water activity because of the intense evaporation rate. However, it induces a high hygroscopicity, thus, powders tend to get wet rapidly if they are not well stored. On the other hand, high temperature provokes a decrease of native serum proteins, which is positively correlated to gelation properties (gel point and firmness). Partial denaturation of serum proteins can improve functional properties of powder. The control of air pressure and outlet temperature during the spray-drying process significantly affects the physicochemical and functional properties of powder. This study permitted to better understand the links between physicochemical and functional properties of powder to identify correlations between air pressure and outlet temperature. Therefore, mathematical models have been developed, and the use of genetic algorithm will allow the optimization of powder functionalities.

Keywords: dairy powders, spray-drying, powders functionalities, design of experiment

Procedia PDF Downloads 65

Authors: Supakorn Tantisriyanurak, Hussaya Maneesuwan, Thanyalak Chaisuwan, Sujitra Wongkasemjit

Abstract:

TUD-1 is a siliceous mesoporous material with a three-dimensional amorphous structure of random, interconnecting pores, large pore size, high surface area (400-1000 m2/g), hydrothermal stability, and tunable porosity. However, the significant disadvantage of the mesoporous silicates is few catalytic active sites. In this work, a series of bimetallic Fe and Ti incorporated into TUD-1 framework is successfully synthesized by sol–gel method. The synthesized Fe,Ti-TUD-1 is characterized by various techniques. To study the catalytic activity of Fe, Ti–TUD-1, phenol hydroxylation was selected as a model reaction. The amounts of residual phenol and oxidation products were determined by high performance liquid chromatography coupled with UV-detector (HPLC-UV).

Keywords: iron, phenol hydroxylation, titanium, TUD-1

Procedia PDF Downloads 258

Authors: Ahmed. Abdel Bary, Omneya. Khowessah, Mojahed. al-jamrah

Abstract:

Introduction: The major challenge with the design of oral dosage forms lies with their poor bioavailability. The most frequent causes of low oral bioavailability are attributed to poor solubility and low permeability. The aim of this study was to develop solid nanodispersed tablet formulation of Glimepiride for the enhancement of the solubility and bioavailability. Methodology: Solid nanodispersions of Glimepiride (GMP) were prepared using two different ratios of 2 different carriers, namely; PEG6000, pluronic F127, and by adopting two different techniques, namely; solvent evaporation technique and fusion technique. A full factorial design of 2 3 was adopted to investigate the influence of formulation variables on the prepared nanodispersion properties. The best chosen formula of nanodispersed powder was formulated into tablets by direct compression. The Differential Scanning Calorimetry (DSC) analysis and Fourier Transform Infra-Red (FTIR) analysis were conducted for the thermal behavior and surface structure characterization, respectively. The zeta potential and particle size analysis of the prepared glimepiride nanodispersions was determined. The prepared solid nanodispersions and solid nanodispersed tablets of GMP were evaluated in terms of pre-compression and post-compression parameters, respectively. Results: The DSC and FTIR studies revealed that there was no interaction between GMP and all the excipients used. Based on the resulted values of different pre-compression parameters, the prepared solid nanodispersions powder blends showed poor to excellent flow properties. The resulted values of the other evaluated pre-compression parameters of the prepared solid nanodispersion were within the limits of pharmacopoeia. The drug content of the prepared nanodispersions ranged from 89.6 ± 0.3 % to 99.9± 0.5% with particle size ranged from 111.5 nm to 492.3 nm and the resulted zeta potential (ζ ) values of the prepared GMP-solid nanodispersion formulae (F1-F8) ranged from -8.28±3.62 mV to -78±11.4 mV. The in-vitro dissolution studies of the prepared solid nanodispersed tablets of GMP concluded that GMP- pluronic F127 combinations (F8), exhibited the best extent of drug release, compared to other formulations, and to the marketed product. One way ANOVA for the percent of drug released from the prepared GMP-nanodispersion formulae (F1- F8) after 20 and 60 minutes showed significant differences between the percent of drug released from different GMP-nanodispersed tablet formulae (F1- F8), (P<0.05). Conclusion: Preparation of glimepiride as nanodispersed particles proven to be a promising tool for enhancing the poor solubility of glimepiride.

Keywords: glimepiride, solid Nanodispersion, nanodispersed tablets, poorly water soluble drugs

Procedia PDF Downloads 488

Authors: Dayane de Almeida

Abstract:

This work aims at presenting a study that demonstrates the usability of categories of analysis from Discourse Semiotics – also known as Greimassian Semiotics in authorship cases in forensic contexts. It is necessary to know if the categories examined in semiotic analysis (the ‘grammar’ of the content plane) can distinguish authors. Thus, a study with 4 sets of texts from a corpus of ‘not on demand’ written samples (those texts differ in formality degree, purpose, addressees, themes, etc.) was performed. Each author contributed with 20 texts, separated into 2 groups of 10 (Author1A, Author1B, and so on). The hypothesis was that texts from a single author were semiotically more similar to each other than texts from different authors. The assumptions and issues that led to this idea are as follows: -The features analyzed in authorship studies mostly relate to the expression plane: they are manifested on the ‘surface’ of texts. If language is both expression and content, content would also have to be considered for more accurate results. Style is present in both planes. -Semiotics postulates the content plane is structured in a ‘grammar’ that underlies expression, and that presents different levels of abstraction. This ‘grammar’ would be a style marker. -Sociolinguistics demonstrates intra-speaker variation: an individual employs different linguistic uses in different situations. Then, how to determine if someone is the author of several texts, distinct in nature (as it is the case in most forensic sets), when it is known intra-speaker variation is dependent on so many factors?-The idea is that the more abstract the level in the content plane, the lower the intra-speaker variation, because there will be a greater chance for the author to choose the same thing. If two authors recurrently chose the same options, differently from one another, it means each one’s option has discriminatory power. -Size is another issue for various attribution methods. Since most texts in real forensic settings are short, methods relying only on the expression plane tend to fail. The analysis of the content plane as proposed by greimassian semiotics would be less size-dependable. -The semiotic analysis was performed using the software Corpus Tool, generating tags to allow the counting of data. Then, similarities and differences were quantitatively measured, through the application of the Jaccard coefficient (a statistical measure that compares the similarities and differences between samples). The results showed the hypothesis was confirmed and, hence, the grammatical categories of the content plane may successfully be used in questioned authorship scenarios.

Keywords: authorship attribution, content plane, forensic linguistics, greimassian semiotics, intraspeaker variation, style

Procedia PDF Downloads 242

Authors: Davendra Singh Malik

Abstract:

India is one of the mega-biodiversity countries in the world and contributing about 11.72% of global fish diversity. The Yamuna river is the longest tributary of Ganga river ecosystem, providing a natural habitat for existing fish diversity of Himalayan region of Indian subcontinent. The several hydropower dams and barrages have been constructed on different locations of major rivers in Garhwal region. These dams have caused a major ecological threat to change existing fresh water ecosystems altering water flows, interrupting ecological connectivity, fragmenting habitats and native riverine fish species. Mahseer fishes (Indian carp) of the genus Tor, are large cyprinids endemic to continental Asia popularly known as ‘Game or sport fishes’ have continued to be decimated by fragmented natural habitats due to damming the water flow in riverine system and categorized as threatened fishes of India. The fresh water fish diversity as 24 fish species were recorded from Yamuna river. The present fish catch data has revealed that mahseer fishes (Tor tor and Tor putitora) were contributed about 32.5 %, 25.6 % and 18.2 % in upper, middle and lower riverine stretches of Yaumna river. The length range of mahseer (360-450mm) recorded as dominant size of catch composition. The CPUE (catch per unit effort) of mahseer fishes also indicated about a sharp decline of fish biomass, changing growth pattern, sex ratio and maturity stages of fishes. Only 12.5 – 14.8 % mahseer female brooders have showed only maturity phases in breeding months. The fecundity of mature mahseer female fish brooders ranged from 2500-4500 no. of ova during breeding months. The present status of mahseer fishery has attributed to the over exploitative nature in Yamuna river. The mahseer population is shrinking continuously in down streams of Yamuna river due to cumulative effects of various ecological stress. Mahseer conservation programme have implemented as 'in situ fish conservation' for enhancement of viable population size of mahseer species and restore the genetic loss of mahseer fish germplasm in Yamuna river of Garhwal Himalayan region.

Keywords: conservation practice, population dynamics, tor fish species, Yamuna River

Procedia PDF Downloads 255

Authors: Majid Eslami

Abstract:

Functionally graded materials (FGMs) exhibit heterogeneous microstructures in which the composition and properties gently change in specified directions. The common type of FGMs consist of a metal in which ceramic particles are distributed with a graded concentration. There are many processing routes for FGMs. An important group of these methods is casting techniques (gravity or centrifugal). However, the main problem of casting molten metal slurry with dispersed ceramic particles is a destructive chemical reaction between these two phases which deteriorates the properties of the materials. In order to overcome this problem, in the present investigation a suspension of 6061 aluminum and alumina powders in a liquid polymer was used as the starting material and subjected to centrifugal force for making FGMs. The size rang of these powders was 45-63 and 106-125 μm. The volume percent of alumina in the Al/Al2O3 powder mixture was in the range of 5 to 20%. PMMA (Plexiglas) in different concentrations (20-50 g/lit) was dissolved in toluene and used as the suspension liquid. The glass mold contaning the suspension of Al/Al2O3 powders in the mentioned liquid was rotated at 1700 rpm for different times (4-40 min) while the arm length was kept constant (10 cm) for all the experiments. After curing the polymer, burning out the binder, cold pressing and sintering , cylindrical samples (φ=22 mm h=20 mm) were produced. The density of samples before and after sintering was quantified by Archimedes method. The results indicated that by using the same sized alumina and aluminum powders particles, FGM sample can be produced by rotation times exceeding 7 min. However, by using coarse alumina and fine alumina powders the sample exhibits step concentration. On the other hand, using fine alumina and coarse alumina results in a relatively uniform concentration of Al2O3 along the sample height. These results are attributed to the effects of size and density of different powders on the centrifugal force induced on the powders during rotation. The PMMA concentration and the vol.% of alumina in the suspension did not have any considerable effect on the distribution of alumina particles in the samples. The hardness profiles along the height of samples were affected by both the alumina vol.% and porosity content. The presence of alumina particles increased the hardness while increased porosity reduced the hardness. Therefore, the hardness values did not show the expected gradient in same sample. The sintering resulted in decreased porosity for all the samples investigated.

Keywords: FGM, powder metallurgy, centrifugal method, polymeric suspension

Procedia PDF Downloads 210

Authors: J. G. Batista, T. S. Santiago, E. A. Ribeiro, G. A. P. Thé

Abstract:

This work deals with parameter identification of permanent magnet motors, a class of ac motor which is particularly important in industrial automation due to characteristics like applications high performance, are very attractive for applications with limited space and reducing the need to eliminate because they have reduced size and volume and can operate in a wide speed range, without independent ventilation. By using experimental data and genetic algorithm we have been able to extract values for both the motor inductance and the electromechanical coupling constant, which are then compared to measure and/or expected values.

Keywords: modeling, AC servomotor, permanent magnet synchronous motor-PMSM, genetic algorithm, vector control, robotic manipulator, control

Procedia PDF Downloads 520

Authors: N. Senu, I. A. Kasim, F. Ismail, N. Bachok

Abstract:

In this paper zero-dissipative explicit Runge-Kutta method is derived for solving second-order ordinary differential equations with periodical solutions. The phase-lag and dissipation properties for Runge-Kutta (RK) method are also discussed. The new method has algebraic order three with dissipation of order infinity. The numerical results for the new method are compared with existing method when solving the second-order differential equations with periodic solutions using constant step size.

Keywords: dissipation, oscillatory solutions, phase-lag, Runge-Kutta methods

Procedia PDF Downloads 411

Authors: Ali Alhajeri, Tarig Makki, Mosa Almutahhar, Mohammed Ahmed, Usman Ali

Abstract:

Metal powder is the raw material used for laser powder-bed fusion (LPBF) additive manufacturing (AM). There are many metal materials that can be used in LPBF. The properties of these materials are varied between each other, which can affect the building part. The objective of this paper is to do an overview of the titanium powders available in LBPF. Comparison between different literature works will lead us to study the similarities and differences between the powder properties such as size, shape, and chemical composition. Furthermore, the results of this paper will point out the significant titanium powder properties in order to clearly illustrate their effect on the build parts.

Keywords: LPBF, titanium, Ti-6Al-4V, Ti-5553, metal powder, AM

Procedia PDF Downloads 174

Authors: Calvin Ralph, Edward Archer, Alistair McIlhagger

Abstract:

3D woven textile composites continue to emerge as an advanced material for structural applications and composite manufacture due to their bespoke nature, through thickness reinforcement and near net shape capabilities. When 3D woven preforms are produced, they are in their optimal physical state. As 3D weaving is a dry preforming technology it relies on compression of the preform to achieve the desired composite thickness, fibre volume fraction (Vf) and consolidation. This compression of the preform during manufacture results in changes to its thickness and architecture which can often lead to under-performance or changes of the 3D woven composite. Unlike traditional 2D fabrics, the bespoke nature and variability of 3D woven architectures makes it difficult to know exactly how each 3D preform will behave during processing. Therefore, the focus of this study is to investigate the effect of compression on differing 3D woven architectures in terms of structure, crimp or fibre waviness and thickness as well as analysing the accuracy of available software to predict how 3D woven preforms behave under compression. To achieve this, 3D preforms are modelled and compression simulated in Wisetex with varying architectures of binder style, pick density, thickness and tow size. These architectures have then been woven with samples dry compression tested to determine the compressibility of the preforms under various pressures. Additional preform samples were manufactured using Resin Transfer Moulding (RTM) with varying compressive force. Composite samples were cross sectioned, polished and analysed using microscopy to investigate changes in architecture and crimp. Data from dry fabric compression and composite samples were then compared alongside the Wisetex models to determine accuracy of the prediction and identify architecture parameters that can affect the preform compressibility and stability. Results indicate that binder style/pick density, tow size and thickness have a significant effect on compressibility of 3D woven preforms with lower pick density allowing for greater compression and distortion of the architecture. It was further highlighted that binder style combined with pressure had a significant effect on changes to preform architecture where orthogonal binders experienced highest level of deformation, but highest overall stability, with compression while layer to layer indicated a reduction in fibre crimp of the binder. In general, simulations showed a relative comparison to experimental results; however, deviation is evident due to assumptions present within the modelled results.

Keywords: 3D woven composites, compression, preforms, textile composites

Procedia PDF Downloads 135

Authors: Ousmane Sarr

Abstract:

The Senegalese coasts have high productivity of fishery resources due to the frequency of intense up-welling system that occurs along its coast, caused by the maritime trade winds making its waters nutrients rich. Fishing plays a primordial role in Senegal's socioeconomic plans and food security. However, a global diagnosis of the Senegalese maritime fishing sector has highlighted the challenges this sector encounters. Among these concerns, some significant stocks, a priority target for artisanal fishing, need further assessment. If no efforts are made in this direction, most stock will be overexploited or even in decline. It is in this context that this research was initiated. This investigation aimed to apply a multi-modal approach (LBB, Catch-only-based CMSY model and its most recent version (CMSY++); JABBA, and JABBA-Select) to assess the stock of Atlantic bonito, Sarda sarda (Bloch, 1793) in the Senegalese Exclusive Economic Zone (SEEZ). Available catch, effort, and size data from Atlantic bonito over 15 years (2004-2018) were used to calculate the nominal and standardized CPUE, size-frequency distribution, and length at retentions (50 % and 95 % selectivity) of the species. These relevant results were employed as input parameters for stock assessment models mentioned above to define the stock status of this species in this region of the Atlantic Ocean. The LBB model indicated an Atlantic bonito healthy stock status with B/BMSY values ranging from 1.3 to 1.6 and B/B0 values varying from 0.47 to 0.61 of the main scenarios performed (BON_AFG_CL, BON_GN_Length, and BON_PS_Length). The results estimated by LBB are consistent with those obtained by CMSY. The CMSY model results demonstrate that the SEEZ Atlantic bonito stock is in a sound condition in the final year of the main scenarios analyzed (BON, BON-bt, BON-GN-bt, and BON-PS-bt) with sustainable relative stock biomass (B2018/BMSY = 1.13 to 1.3) and fishing pressure levels (F2018/FMSY= 0.52 to 1.43). The B/BMSY and F/FMSY results for the JABBA model ranged between 2.01 to 2.14 and 0.47 to 0.33, respectively. In contrast, The estimated B/BMSY and F/FMSY for JABBA-Select ranged from 1.91 to 1.92 and 0.52 to 0.54. The Kobe plots results of the base case scenarios ranged from 75% to 89% probability in the green area, indicating sustainable fishing pressure and an Atlantic bonito healthy stock size capable of producing high yields close to the MSY. Based on the stock assessment results, this study highlighted scientific advice for temporary management measures. This study suggests an improvement of the selectivity parameters of longlines and purse seines and a temporary prohibition of the use of sleeping nets in the fishery for the Atlantic bonito stock in the SEEZ based on the results of the length-base models. Although these actions are temporary, they can be essential to reduce or avoid intense pressure on the Atlantic bonito stock in the SEEZ. However, it is necessary to establish harvest control rules to provide coherent and solid scientific information that leads to appropriate decision-making for rational and sustainable exploitation of Atlantic bonito in the SEEZ and the Eastern Atlantic Ocean.

Keywords: multi-model approach, stock assessment, atlantic bonito, healthy stock, sustainable, SEEZ, temporary management measures

Procedia PDF Downloads 58

Authors: Ibrahim Hassan

Abstract:

Motion typography is one of the most important types of visual communication based on display. Through the digital display media, we can control the text properties (size, direction, thickness, color, etc.). The use of motion typography in visual communication made it have several images. We need to adjust the terminology and clarify the different differences between them, so relying on the word motion typography -considered a general term- is not enough to separate the different communicative functions of the moving text. In this paper, we discuss the different effects of motion typography on Arabic writing and how we can achieve harmony between the movement and the letterform, and we will, during our experiments, present a new type of text movement.

Keywords: Arabic typography, motion typography, kinetic typography, fluid typography, temporal typography

Procedia PDF Downloads 160

Authors: Krupali Mehta, Sandip Bhatt, Umesh Trivedi, Bhavesh Bharatiya, Mukesh Ranjan, Atindra D. Shukla

Abstract:

Owing to the dominating surface forces and large-scale surface interactions, the nano-scale particles face difficulties in getting suspended in various media. Magnetic nanoparticles of iron oxide offer a great deal of promise due to their ease of preparation, reasonable magnetic properties, low cost and environmental compatibility. We intend to modify the surface of magnetic Fe₂O₃ nanoparticles with selected surface modifying agents using simple and effective single-step chemical reactions in order to enhance dispersibility of magnetic nanoparticles in non-polar media. Magnetic particles were prepared by hydrolysis of Fe²⁺/Fe³⁺ chlorides and their subsequent oxidation in aqueous medium. The dried particles were then treated with Octadecyl quaternary ammonium silane (Terrasil™), stearic acid and gallic acid ester of stearyl alcohol in ethanol separately to yield S-2 to S-4 respectively. The untreated Fe₂O₃ was designated as S-1. The surface modified nanoparticles were then analysed with Dynamic Light Scattering (DLS), Fourier Transform Infrared spectroscopy (FTIR), X-Ray Diffraction (XRD), Thermogravimetric Gravimetric Analysis (TGA) and Scanning Electron Microscopy and Energy dispersive X-Ray analysis (SEM-EDAX). Characterization reveals the particle size averaging 20-50 nm with and without modification. However, the crystallite size in all cases remained ~7.0 nm with the diffractogram matching to Fe₂O₃ crystal structure. FT-IR suggested the presence of surfactants on nanoparticles’ surface, also confirmed by SEM-EDAX where mapping of elements proved their presence. TGA indicated the weight losses in S-2 to S-4 at 300°C onwards suggesting the presence of organic moiety. Hydrophobic character of modified surfaces was confirmed with contact angle analysis, all modified nanoparticles showed super hydrophobic behaviour with average contact angles ~129° for S-2, ~139.5° for S-3 and ~151° for S-4. This indicated that surface modified particles are super hydrophobic and they are easily dispersible in non-polar media. These modified particles could be ideal candidates to be suspended in oil-based fluids, polymer matrices, etc. We are pursuing elaborate suspension/sedimentation studies of these particles in various oils to establish this conjecture.

Keywords: iron nanoparticles, modification, hydrophobic, dispersion

Procedia PDF Downloads 141

Authors: R. S. Hassani, S. Chikh, L. Tadrist, S. Radev

Abstract:

A bubbly flow in a vertical miniature tube is analyzed theoretically. The liquid and gas phase are co-current flowing upward. The gas phase is injected via a nozzle whose inner diameter is 0.11mm and it is placed on the axis of the tube. A force balance is applied on the bubble at its detachment. The set of governing equations are solved by use of Mathematica software. The bubble diameter and the bubble generation frequency are determined for various inlet phase velocities represented by the inlet mass quality. The results show different behavior of bubble growth and detachment depending on the tube size.

Keywords: two phase flow, bubble growth, mini-channel, generation frequency

Procedia PDF Downloads 432

Authors: Enrique Barra, Abel Carril, Aldo Gordillo, Joaquin Salvachua, Juan Quemada

Abstract:

Computers and multimedia equipment have improved a lot in the last years. They have reduced costs and size while at the same time has increased their capabilities. These improvements allowed us to design and implement a portable recording system that also integrates the teacher´s tablet PC to capture what he/she writes on the slides and all that happens in it. This paper explains this system in detail and the validation of the recordings that we did after using it to record all the lectures of a course in our university called “Communications Software”. The results show that pupils used the recordings for different purposes and consider them useful for a variety of things, especially after missing a lecture.

Keywords: recording system, capture dynamic presentations, lecture recording

Procedia PDF Downloads 366

Authors: Zeinab Jokar, Mohammad Reza Moslemi

Abstract:

In this work, we study the behavior of introducing atomic size vacancy in a graphene nanoribbon superlattice. Our investigations are based on the density functional theory (DFT) with the Local Density Approximation in Atomistix Toolkit (ATK). We show that, in addition to its shape, the position of vacancy has a major impact on the electrical properties of a graphene nanoribbon superlattice. We show that the band gap of an armchair graphene nanoribbon may be tuned by introducing an appropriate periodic pattern of vacancies. The band gap changes in a zig-zag manner similar to the variation of the band gap of a graphene nanoribbon by changing its width.

Keywords: AGNR, antidot, atomistic toolKit, vacancy

Procedia PDF Downloads 1006

Authors: Lopez J., Mehrvar M., Quinones E., Suarez A., RomeroC.

Abstract:

The Silver Nanoparticles (AgNP) are used as deliver of heat on surface of Membrane Distillation in order to fight against Thermal Polarization and improving the Desalination Process. In this study AgNPwere deposited by dip coating process over PVDF, FG hydrophilic, and PTFE hydrophobic commercial membranes as substrate. Membranes were characterized by SEM, EDS, contact angle, Pore size distributionand using a UV lamp and a thermal camera were measured the performance of heat deliver. The presence of AgNP 50 – 150 nm and the increase in absorption of energy over membrane were verified.

Keywords: silver nanoparticles, membrane distillation, plasmon effect, heat deliver

Procedia PDF Downloads 125

Authors: Kemal Kehan, Emine Aktas Bajalan

Abstract:

This study was carried out to determine the burnout levels and related factors of teachers working in primary schools affiliated to the Turkish Republic of Northern Cyprus (TRNC) Ministry of National Education during the COVID-19 pandemic period. The research was conducted in descriptive cross-sectional design. The population of the research consists of 1071 teachers working in 93 primary schools in 6 central districts affiliated to the TRNC Ministry of National Education in the 2021-2022 academic year. When the sample size of the study was calculated by power analysis, it was determined that 202 teachers should be reached with 95% confidence (1-α), 95% test power (1-β) and d=0.5 effect size. Within the scope of the inclusion criteria of the research, the main sample of the study consisted of 300 teachers and the baist random sampling method was used. The data were collected using the Sociodemographic Data Form consisting of 34 questions, including the sociodemographic characteristics of the teachers and the 22-item Maslach Burnout Scale (MBS). The analysis of the data was carried out using descriptive and correlational analyzes in the SPSS 22 package program. In the study, it was determined that 65% of the teachers were women, 68% were married, 84% had a bachelor's degree, 70.33% had children, and 67.67% were dependents. Regarding how teachers evaluate the COVID-19 pandemic period; 90% of them said, “I am worried about my family's health and the risk of infection”, 80% of them, “I feel that my profession does not get the value it deserves”, 75.67% of them mentioned “My hopes for the future have started to wane”, 75.33% of them say “I am worried about my own health”. It was determined that they gave the answer of, “I am worried about the issue”. It was found that the teachers' MBS total score average was 48.63±8.01, the burnout level was moderate, and the average score they got from the sub-dimensions of the scale was also moderate. It has been found that there are negative correlations between the professional satisfaction scores of the teachers during and before the COVID-19 pandemic and the scores they received from the general and sub-dimensions of MBS. It was determined that there was a statistically significant difference (p<0.05) between the scores of teachers diagnosed with COVID-19 from the scale and its sub-dimensions. As a result, it is suggested that social activities should be increased and professional development and promotion opportunities should be offered in order to ensure that teachers are satisfied with their work areas, to reduce their burnout levels or to prevent them completely.

Keywords: teachers, burnout, maslach burnout scale, pandemic, online education

Procedia PDF Downloads 65

Authors: M. V. Shivaani, P. K. Jain, Surendra S. Yadav

Abstract:

Worldwide regulators, practitioners and researchers view risk-disclosure as one of the most important steps that will promote corporate accountability and transparency. Recognizing this growing significance of risk disclosures, the paper first develops a risk disclosure index. Covering 69 risk items/themes, this index is developed by employing thematic content analysis and encompasses three attributes of disclosure: namely, nature (qualitative or quantitative), time horizon (backward-looking or forward-looking) and tone (no impact, positive impact or negative impact). As the focus of study is on substantive rather than symbolic disclosure, content analysis has been carried out manually. The study is based on non-financial companies of Nifty500 index and covers a ten year period from April 1, 2005 to March 31, 2015, thus yielding 3,872 annual reports for analysis. The analysis reveals that (on an average) only about 14% of risk items (i.e. about 10 out 69 risk items studied) are being disclosed by Indian companies. Risk items that are frequently disclosed are mostly macroeconomic in nature and their disclosures tend to be qualitative, forward-looking and conveying both positive and negative aspects of the concerned risk. The second objective of the paper is to gauge the factors that affect the level of disclosures in annual reports. Given the panel nature of data, and possible endogeneity amongst variables, Diff-GMM regression has been applied. The results indicate that age and size of firms have a significant positive impact on disclosure quality, whereas growth rate does not have a significant impact. Further, post-recession period (2009-2015) has witnessed significant improvement in quality of disclosures. In terms of corporate governance variables, board size, board independence, CEO duality, presence of CRO and constitution of risk management committee appear to be significant factors in determining the quality of risk disclosures. It is noteworthy that the study contributes to literature by putting forth a variant to existing disclosure indices that not only captures the quantity but also the quality of disclosures (in terms of semantic attributes). Also, the study is a first of its kind attempt in a prominent emerging market i.e. India. Therefore, this study is expected to facilitate regulators in mandating and regulating risk disclosures and companies in their endeavor to reduce information asymmetry.

Keywords: risk disclosure, voluntary disclosures, corporate governance, Diff-GMM

Procedia PDF Downloads 162

Authors: Yin-Hsuan Wu, Perng-Jy Tsai, Ying-Fang Wang, Shun-Hui Chung

Abstract:

The present study was conducted to characterize exposure concentrations, concentrations deposited on the different respiratory regions, and resultant health risks associated with heavy metal exposures for road marking workers. Road marking workers of three similar exposure groups (SEGs) were selected, including the paint pouring worker, marking worker, and preparing worker. Personal exposure samples were collected using an inhalable dust sampler (IOM), and the involved particle size distribution samples were estimated using an eight-stage Marple personal cascade impactor during five working days. In total, 25 IOM samples and 20 Marple samples were collected. All collected samples were analyzed for their heavy metal contents using the ICP/MS. The resultant heavy metal particle size distributions were also used to estimate the fractions of particle deposited on the head airways (Chead), tracheobronchial (Cthorac) and alveolar regions (Cresp) of the exposed workers. In addition, Pb and Cr were selected to estimate the incremental cancer risk, and Zn, Ti, and Mo were selected to estimate the corresponding non-cancer risk in the present study. Results show that three heavy metals, including Pb, Cr, and Ti, were found with the highest concentrations for the SEG of the paint pouring worker (=0.585±2.98, 0.307±1.71, 0.902±2.99 μg/m³, respectively). For the fraction of heavy metal particle deposited on the respiratory tract, both alveolar and head regions were found with the highest values (=23-43% and 39-61%, respectively). For both SEGs of the paint pouring and marking, 51% of Cr, 59-61% of Zn, and 48-51% of Ti were found to be deposited on the alveolar region, and 41-43% of Pb was deposited on the head region. Finally, the incremental cancer risk for the SEGs of the paint pouring, marking, and preparing were found as 1.08×10⁻⁵, 2.78×10⁻⁶, and 2.20×10⁻⁶, respectively. In addition, the estimated non-cancer risk for the above three SEGs was found to be consistently less than unity. In conclusion, though the estimated non-cancer risk was less than unity, all resultant incremental cancer risk was greater than 10⁻⁶ indicating the abatement of workers’ exposure is necessary. It is suggested that strategies, including placing on the molten kettle, substitution the currently used paints for less heavy metal containing paints, and wearing fume protecting personal protective equipment can be considered in the future from reducing the worker’s exposure aspect.

Keywords: health risk assessment, heavy metal, respiratory track deposition, road marking

Procedia PDF Downloads 169

Authors: Sandeep K. Saxena, N. Viswanadham, Ala’a H. Al-Muhtaseb

Abstract:

In an attempt to facilitate effective conversion of biomass derived products into gasoline rich in aromatics and iso-paraffins, various zeolite catalysts with special features such as nano crystallite size and acidity has been synthesized and evaluated. The catalyst (NZ) exhibits highest gasoline yield of about 74wt% with aromatics and iso-paraffins as major components. The product measures Research Octane Number (RON) of about 95, which is desirable for the gasoline specifications. Moreover, considerable amount of the Liquefied Petroleum Gas (LPG) (15wt%) and light olefins (14wt%) are also formed as bi-product that adds value to the process. The study reveals the effective conversion of bio- ethanol to high-octane gasoline.

Keywords: biomass, ethanol, acetone, gasoline, zeolite

Procedia PDF Downloads 447

Authors: Na Young Kim

Abstract:

This is a study on the relation between the introduction bill of the Whistle Blowing Act and the CPI (Corruption Perception Index) from 1998 to 2019. It shows that the degree of corruption can be relatively lowered when WBA is introduced, and the system is matured. And when WBA was introduced at the national level and matured, it was found that it could have a greater impact on corruption. Secondly, it shows that OECD countries may have relatively low levels of corruption. In addition to the two variables representing democracy, when additional control variables (GDP (economic power), population size, HDI (education level), etc.) are controlled under the same conditions, the degree of corruption in countries with high political rights can be low (it means clean), while those with high civil freedom can be serious (it means not clean).

Keywords: Whistle Blowing Act, anti-corruption, CPI, GDP

Procedia PDF Downloads 61

Authors: Rowanda Daoud Ahmed, Mansoor Abdulhak, Muhammad Azeem Afzal, Sezer Filiz, Usama Ahmad Mughal

Abstract:

This paper discusses important aspects of AI in the healthcare domain. The increase of data in healthcare both in size and complexity, opens more room for artificial intelligence applications. Our focus is to review the main AI methods within the scope of the health care domain. The results of the review show that recommendations for diagnosis and recommendations for treatment, patent engagement, and administrative tasks are the key applications of AI in healthcare. Understanding the potential of AI methods in the domain of healthcare would benefit healthcare practitioners and will improve patient outcomes.

Keywords: AI in healthcare, technologies of AI, neural network, future of AI in healthcare

Procedia PDF Downloads 112

Authors: Hashem M. Alargha, Mohammad O. Hamdan, Waseem H. Aziz

Abstract:

Aerobatic and military pilots are subjected to high gravitational forces that could cause blackout, physical injuries or death. A CFD simulation using fluid-solid interactions scheme has been conducted to investigate the gravitational effects and hazards inside cerebral aneurysms. Medical data have been used to derive the size and geometry of a simple aneurysm on a T-shaped bifurcation. The results show that gravitational force has no effect on maximum Wall Shear Stress (WSS); hence, it will not cause aneurysm initiation/formation. However, gravitational force cause causes hypertension which could contribute to aneurysm rupture.

Keywords: aneurysm, cfd, wall shear stress, gravity, fluid dynamics, bifurcation artery

Procedia PDF Downloads 367

Authors: Della Saddam Housseyn

Abstract:

Gold, the quintessential noble metal, is one of the most popular metals today, given its ever-increasing cost in the international market. The Amesmessa gold deposit is one of the gold-producing deposits. The first step in our job is to analyze the ore (considered rich ore). Mineralogical and chemical analysis has shown that the general constitution of the ore is quartz in addition to other phases such as Al2O3, Fe2O3, CaO, dolomite. The second step consists of all the leaching tests carried out in rolling bottles. These tests were carried out on 14 samples to determine the maximum recovery rate and the optimum consumption of reagent (NaCN and CaO). Tests carried out on a pulp density at 50% solid, 500 ppm cyanide concentration and particle size less than 0.6 mm at alkaline pH gave a recovery rate of 94.37%.

Keywords: cyanide, DRX, FX, gold, leaching, rate of recovery, SAA

Procedia PDF Downloads 181

Authors: Neli P. Zlatareva

Abstract:

Ontology validation is an important part of web applications’ development, where knowledge integration and ontological reasoning play a fundamental role. It aims to ensure the consistency and correctness of ontological knowledge and to guarantee that ontological reasoning is carried out in a meaningful way. Existing approaches to ontology validation address more or less specific validation issues, but the overall process of validating web ontologies has not been formally established yet. As the size and the number of web ontologies continue to grow, the necessity to validate and ensure their consistency and interoperability is becoming increasingly important. This paper presents a validation technique intended to test the consistency of independent ontologies utilized by a common application.

Keywords: knowledge engineering, ontological reasoning, ontology validation, semantic web

Procedia PDF Downloads 322

Authors: V. Ziegler, F. Schneider, M. Pesch

Abstract:

With the EDM264, GRIMM offers a solution for mobile short- and long-term measurements in outdoor areas and at production sites. For research as well as permanent areal observations on a near reference quality base. The model EDM264 features a powerful and robust measuring cell based on optical particle counting (OPC) principle with all the advantages that users of GRIMM's portable aerosol spectrometers are used to. The system is embedded in a compact weather-protection housing with all-weather sampling, heated inlet system, data logger, and meteorological sensor. With TSP, PM10, PM4, PM2.5, PM1, and PMcoarse, the EDM264 provides all fine dust fractions real-time, valid for outdoor applications and calculated with the proven GRIMM enviro-algorithm, as well as six additional dust mass fractions pm10, pm2.5, pm1, inhalable, thoracic and respirable for IAQ and workplace measurements. This highly versatile instrument performs real-time monitoring of particle number, particle size and provides information on particle surface distribution as well as dust mass distribution. GRIMM's EDM264 has 31 equidistant size channels, which are PSL traceable. A high-end data logger enables data acquisition and wireless communication via LTE, WLAN, or wired via Ethernet. Backup copies of the measurement data are stored in the device directly. The rinsing air function, which protects the laser and detector in the optical cell, further increases the reliability and long term stability of the EDM264 under different environmental and climatic conditions. The entire sample volume flow of 1.2 L/min is analyzed by 100% in the optical cell, which assures excellent counting efficiency at low and high concentrations and complies with the ISO 21501-1standard for OPCs. With all these features, the EDM264 is a world-leading dust monitor for precise monitoring of particulate matter and particle number concentration. This highly reliable instrument is an indispensable tool for many users who need to measure aerosol levels and air quality outdoors, on construction sites, or at production facilities.

Keywords: aerosol research, aerial observation, fence line monitoring, wild fire detection

Procedia PDF Downloads 151

Authors: Ahmet Sekreter

Abstract:

Although there are conceptual similarities in terms of financial products between conventional and Islamic finance, they are entirely different financial systems. Despite Islamic finance’s small size in the conventional finance world, its promising growth makes Islamic finance a hot topic both in academia and business world. Today customers can access sophisticated Islamic financial products not only in Muslim countries but also in Europe. This study analyzes Islamic finance and its products and includes a brief overview of Islamic finance in Europe. Literature review is the basis of this paper. The author analyzed the academic papers, numerical data, and estimations to set a perspective for the future of Islamic finance in Europe. Findings show that UK is the main hub for the Islamic finance, and it will remain so in the near future.

Keywords: islamic finance, islamic banking, islamic finance in Europe, finance

Procedia PDF Downloads 238