Search results for: high volume
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 21798

Search results for: high volume

19458 Fluoride Removal from Groundwater in the East Nile Area (Sudan) Using Locally Available Charcoal

Authors: Motwkel M. Alhaj, Bashir M. Elhassan

Abstract:

The East Nile area is located in Khartoum state. The main source of drinking water in the East Nile Area (Sudan) is groundwater. However, fluoride concentration in the water is more than the maximum allowable dose, which is 1.5 mg/l. This study aims to demonstrate and innovative, affordable, and efficient filter to remove fluoride from drinking water. Many researchers have found that aluminum oxide-coated adsorbent is the most affordable technology for fluoride removal. However, adsorption is pH-dependent, and the water pH in the East Nile area is relatively high (around 8), which is hindering the adsorption process. Locally available charcoal was crushed, sieved, and coated with aluminum oxide. Then, different coating configurations were tested in order to produce an adsorbent with a high pH point of zero charge pH PZC in order to overcome the effect of high pH of water. Moreover, different methods were used to characterize the adsorbent, including: Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDX), Brunauer - Emmett - Teller (BET) method, and pH point of zero charge pH PZC. The produced adsorbent has pH PZC of 8.5, which is essential in enhancing the fluoride adsorption process. A pilot household fluoride filter was also designed and installed in a house that has water with 4.34 mg/l F- and pH of 8.4. The filter was operated at a flow rate 250 cm³/min. The total cost of treating one cubic meter was about 0.63$, while the cost for the same water before adsorbent coating modification was 2.33$⁄cm³.

Keywords: water treatment, fluoride, adsorption, charcoal, Sudan

Procedia PDF Downloads 116
19457 Starting Characteristic Analysis of LSPM for Pumping System Considering Demagnetization

Authors: Subrato Saha, Yun-Hyun Cho

Abstract:

This paper presents the design process of a high performance 3-phase 3.7 kW 2-pole line start permanent magnet synchronous motor for pumping system. A method was proposed to study the starting torque characteristics considering line start with high inertia load. A d-q model including cage was built to study the synchronization capability. Time-stepping finite element method analysis was utilized to accurately predict the dynamic and transient performance, efficiency, starting current, speed curve and, etc. Considering the load torque of pumps during starting stage, the rotor bar was designed with minimum demagnetization of permanent magnet caused by huge starting current.

Keywords: LSPM, starting analysis, demagnetization, FEA, pumping system

Procedia PDF Downloads 471
19456 The Impact of Fiscal Policy on Gross Domestic Product under Contributions of Level of External Debt in Developing Countries

Authors: Zohreh Bang Tavakoli, Shuktika Chatterjee

Abstract:

This study investigates the fiscal policy impact on countries’ economic growth in developing countries with a different external debt level. The fiscal policy effectiveness has been re-emphasized in the global financial crisis of 2008 with the external debt as its new contemporary driver (Ruščáková and Semančíková, 2016). According to Bouakez, (2014 ) different theories have proposed the economic consequence of fiscal policy, specifically for developing countries. However, fiscal policy literature is lacking research regarding the fiscal policy’s effectiveness with the external debt’s contributions through comprehensive study (Canh, 2018). Also, according to scholars, high levels of external debt will influence economic growth. First, through foreign resources and channel of investment in which high level of debt decreases the amount of foreign investment in the developing countries. Second, through the deterioration of foreign investors and fiscal policies related to a high level of debt (Cordella, et.al., 2010). Therefore, this study proposed that only countries with a low external debt level and appropriate fiscal policies and good quality institutions can gain the proper quantity and quality of foreign investors, which will help the economic growth. For this, this research is examining the impact of fiscal policy on developing countries' economic growth in the situation of different external debt levels.

Keywords: fiscal policy, external debt, gross domestic product, developing countries

Procedia PDF Downloads 160
19455 Numerical Modeling of Air Shock Wave Generated by Explosive Detonation and Dynamic Response of Structures

Authors: Michał Lidner, Zbigniew SzcześNiak

Abstract:

The ability to estimate blast load overpressure properly plays an important role in safety design of buildings. The issue of studying of blast loading on structural elements has been explored for many years. However, in many literature reports shock wave overpressure is estimated with simplified triangular or exponential distribution in time. This indicates some errors when comparing real and numerical reaction of elements. Nonetheless, it is possible to further improve setting similar to the real blast load overpressure function versus time. The paper presents a method of numerical analysis of the phenomenon of the air shock wave propagation. It uses Finite Volume Method and takes into account energy losses due to a heat transfer with respect to an adiabatic process rule. A system of three equations (conservation of mass, momentum and energy) describes the flow of a volume of gaseous medium in the area remote from building compartments, which can inhibit the movement of gas. For validation three cases of a shock wave flow were analyzed: a free field explosion, an explosion inside a steel insusceptible tube (the 1D case) and an explosion inside insusceptible cube (the 3D case). The results of numerical analysis were compared with the literature reports. Values of impulse, pressure, and its duration were studied. Finally, an overall good convergence of numerical results with experiments was achieved. Also the most important parameters were well reflected. Additionally analyses of dynamic response of one of considered structural element were made.

Keywords: adiabatic process, air shock wave, explosive, finite volume method

Procedia PDF Downloads 192
19454 Influence of Milled Waste Glass to Clay Ceramic Foam Properties Made by Direct Foaming Route

Authors: A. Shishkin, V. Mironovs, D. Goljandin, A. Korjakins

Abstract:

The goal of this work is to develop sustainable and durable ceramic cellular structures using widely available natural resources- clay and milled waste glass. Present paper describes method of obtaining clay ceramic foam (CCF) with addition of milled waste glass in 5, 7 and 10 wt% by direct foaming with high speed mixer-disperser (HSMD). For more efficient clay and waste glass milling and mixing, the high velocity disintegrator was used. The CCF with 5, 7, and 10 wt% were obtained at 900, 950, 1000 and 1050 °C firing temperature and they have demonstrated mechanical compressive strength for all 12 samples ranging from 3.8 to 14.3 MPa and porosity 76-65%. Obtained CCF has compressive strength 14.3 MPa and porosity 65.3%.

Keywords: ceramic foam, waste glass, clay foam, glass foam, open cell, direct foaming

Procedia PDF Downloads 310
19453 Highway Casualty Rate in Nigeria: Implication for Human Capital Development

Authors: Ali Maji

Abstract:

Highway development is an important factor for economic growth and development in both developed and developing countries. In Nigeria about two-third of transportation of goods and persons are done through highway network. It was this that made highway investment to enjoy position of relative high priority on the list of government expenditure programmes in Nigeria today. The paper noted that despite expansion of public investment in highway construction and maintenance of them, road traffic accident is increasing rate. This has acted as a drain of human capital which is a key to economic growth and development in Nigeria. In order to avoid this, the paper recommend introduction of Highway Safety Education (HSE) in Nigerian’s education system and investment in train transportation among other as a sure measure for curtailing highway accident.

Keywords: accident rate, high way development, human capital, national development

Procedia PDF Downloads 286
19452 Influences of Socioeconomic Status and Age on Child Creativity: An Exploratory Study Applied to School Children in Poland

Authors: Bernard Vaernes

Abstract:

Creativity is thought to be of importance for educational success. Educational institutions vary greatly in regard to socioeconomic status (SES) and curricular emphasis on creativity. Research is needed to clarify the effects of age and SES on creativity. The objective of this study will be to compare the creative performance of children with different SES, low or high, and age. It is hypothesized that younger children will score higher than older children, independent of their SES. Children aged 15, 12, and 9 from four different junior and secondary schools in Warsaw, Poland, will participate in the study. The schools will differ in terms of socioeconomic, geographic localization. To assess creative performance, a Polish adaptation of the Torrance Test of Creative Thinking (TTCT) will be used. In order to select low and high SES individuals for SES grouping, a Polish adaptation of the MacArthur Scale of Subjective Social Status will be given to all participants. To control for individual differences in personality traits, a Polish adaptation of the Big Five Questionnaire for Children (BFQ-C) will be used. These measures will allow to compare the creative performance of children with different age and SES and eliminate confound variables. It is predicted that younger children, as well as high SES children, will score higher on the TTCT than older children, and low SES children. The findings of this study may provide useful insight into socioeconomic and age differences in creativity, as well as facilitating teacher’s adjustment of learning styles and emphasis on creativity in relation to the SES and age of their students.

Keywords: big five questionnaire for children, children, creativity, socioeconomic status, Torrance test of creative thinking, TTCT

Procedia PDF Downloads 140
19451 Numerical Homogenization of Nacre

Authors: M. Arunachalam, M. Pandey

Abstract:

Nacre, a biological material that forms the inner-layer of sea shells can achieve high toughness and strength by way of staggered arrangement of strong tablets with soft and weak organic interface. Under applied loads the tablets slide over the adjacent tablets, thus generating inelastic deformation and toughness on macroscopic scale. A two dimensional finite element based homogenization methodology is adopted for obtaining the effective material properties of Nacre using a representative volume element (RVE) at finite deformations. In this work, the material behaviour for tablet and interface are assumed to be Isotropic elastic and Isotropic elastic-perfectly plastic with strain softening respectively. Numerical experiments such as uniaxial tension test along X, Y directions and simple shear test are performed on the RVE with uniform displacement and periodic constraints applied at the RVE boundaries to obtain the anisotropic homogenized response and maximum local stresses within each constituents of Nacre. Homogenized material model is then tested for macroscopic structure under three point bending condition and the results obtained are comparable with the results obtained for detailed microstructure based structure, thus homogenization provides a bridge between macroscopic scale and microscopic scale and homogenized material properties obtained from microstructural (RVE) analysis could be used in large scale structural analysis.

Keywords: finite element, homogenization, inelastic deformation, staggered arrangement

Procedia PDF Downloads 318
19450 Computational Homogenization of Thin Walled Structures: On the Influence of the Global vs Local Applied Plane Stress Condition

Authors: M. Beusink, E. W. C. Coenen

Abstract:

The increased application of novel structural materials, such as high grade asphalt, concrete and laminated composites, has sparked the need for a better understanding of the often complex, non-linear mechanical behavior of such materials. The effective macroscopic mechanical response is generally dependent on the applied load path. Moreover, it is also significantly influenced by the microstructure of the material, e.g. embedded fibers, voids and/or grain morphology. At present, multiscale techniques are widely adopted to assess micro-macro interactions in a numerically efficient way. Computational homogenization techniques have been successfully applied over a wide range of engineering cases, e.g. cases involving first order and second order continua, thin shells and cohesive zone models. Most of these homogenization methods rely on Representative Volume Elements (RVE), which model the relevant microstructural details in a confined volume. Imposed through kinematical constraints or boundary conditions, a RVE can be subjected to a microscopic load sequence. This provides the RVE's effective stress-strain response, which can serve as constitutive input for macroscale analyses. Simultaneously, such a study of a RVE gives insight into fine scale phenomena such as microstructural damage and its evolution. It has been reported by several authors that the type of boundary conditions applied to the RVE affect the resulting homogenized stress-strain response. As a consequence, dedicated boundary conditions have been proposed to appropriately deal with this concern. For the specific case of a planar assumption for the analyzed structure, e.g. plane strain, axisymmetric or plane stress, this assumption needs to be addressed consistently in all considered scales. Although in many multiscale studies a planar condition has been employed, the related impact on the multiscale solution has not been explicitly investigated. This work therefore focuses on the influence of the planar assumption for multiscale modeling. In particular the plane stress case is highlighted, by proposing three different implementation strategies which are compatible with a first-order computational homogenization framework. The first method consists of applying classical plane stress theory at the microscale, whereas with the second method a generalized plane stress condition is assumed at the RVE level. For the third method, the plane stress condition is applied at the macroscale by requiring that the resulting macroscopic out-of-plane forces are equal to zero. These strategies are assessed through a numerical study of a thin walled structure and the resulting effective macroscale stress-strain response is compared. It is shown that there is a clear influence of the length scale at which the planar condition is applied.

Keywords: first-order computational homogenization, planar analysis, multiscale, microstrucutures

Procedia PDF Downloads 233
19449 Fuzzy Logic Modeling of Evaluation the Urban Skylines by the Entropy Approach

Authors: Murat Oral, Seda Bostancı, Sadık Ata, Kevser Dincer

Abstract:

When evaluating the aesthetics of cities, an analysis of the urban form development depending on design properties with a variety of factors is performed together with a study of the effects of this appearance on human beings. Different methods are used while making an aesthetical evaluation related to a city. Entropy, in its preliminary meaning, is the mathematical representation of thermodynamic results. Measuring the entropy is related to the distribution of positional figures of a message or information from the probabilities standpoint. In this study, analysis of evaluation the urban skylines by the entropy approach was modelled with Rule-Based Mamdani-Type Fuzzy (RBMTF) modelling technique. Input-output parameters were described by RBMTF if-then rules. Numerical parameters of input and output variables were fuzzificated as linguistic variables: Very Very Low (L1), Very Low (L2), Low (L3), Negative Medium (L4), Medium (L5), Positive Medium (L6), High (L7), Very High (L8) and Very Very High (L9) linguistic classes. The comparison between application data and RBMTF is done by using absolute fraction of variance (R2). The actual values and RBMTF results indicated that RBMTF can be successfully used for the analysis of evaluation the urban skylines by the entropy approach. As a result, RBMTF model has shown satisfying relation with experimental results, which suggests an alternative method to evaluation of the urban skylines by the entropy approach.

Keywords: urban skylines, entropy, rule-based Mamdani type, fuzzy logic

Procedia PDF Downloads 290
19448 Study and GIS Development of Geothermal Potential in South Algeria (Adrar Region)

Authors: A. Benatiallah, D. Benatiallah, F. Abaidi, B. Nasri, A. Harrouz, S. Mansouri

Abstract:

The region of Adrar is located in the south-western Algeria and covers a total area of 443.782 km², occupied by a population of 432,193 inhabitants. The main activity of population is agriculture, mainly based on the date palm cultivation occupies a total area of 23,532 ha. Adrar region climate is a continental desert characterized by a high variation in temperature between months (July, August) it exceeds 48°C and coldest months (December, January) with 16°C. Rainfall is very limited in frequency and volume with an aridity index of 4.6 to 5 which corresponds to a type of arid climate. Geologically Adrar region is located on the edge North West and is characterized by a Precambrian basement cover stolen sedimentary deposit of Phanerozoic age transgressive. The depression is filled by Touat site Paleozoic deposits (Cambrian to Namurian) of a vast sedimentary basin extending secondary age of the Saharan Atlas to the north hamada Tinhirt Tademaït and the plateau of south and Touat Gourara west to Gulf of Gabes in the Northeast. In this work we have study geothermal potential of Adrar region from the borehole data eatable in various sites across the area of 400,000 square kilometres; from these data we developed a GIS (Adrar_GIS) that plots data on the various points and boreholes in the region specifying information on available geothermal potential has variable depths.

Keywords: sig, geothermal, potenteil, temperature

Procedia PDF Downloads 465
19447 Thermal Performance Analysis of Nanofluids in a Concetric Heat Exchanger Equipped with Turbulators

Authors: Feyza Eda Akyurek, Bayram Sahin, Kadir Gelis, Eyuphan Manay, Murat Ceylan

Abstract:

Turbulent forced convection heat transfer and pressure drop characteristics of Al2O3–water nanofluid flowing through a concentric tube heat exchanger with and without coiled wire turbulators were studied experimentally. The experiments were conducted in the Reynolds number ranging from 4000 to 20000, particle volume concentrations of 0.8 vol.% and 1.6 vol.%. Two turbulators with the pitches of 25 mm and 39 mm were used. The results of nanofluids indicated that average Nusselt number increased much more with increasing Reynolds number compared to that of pure water. Thermal conductivity enhancement by the nanofluids resulted in heat transfer enhancement. Once the pressure drop of the alumina/water nanofluid was analyzed, it was nearly equal to that of pure water at the same Reynolds number range. It was concluded that nanofluids with the volume fractions of 0.8 and 1.6 did not have a significant effect on pressure drop change. However, the use of wire coils in heat exchanger enhanced heat transfer as well as the pressure drop.

Keywords: turbulators, heat exchanger, nanofluids, heat transfer enhancement

Procedia PDF Downloads 407
19446 Salinity Stress: Effects on Growth Biochemical Parameters and Ion Homeostasis in Spinach (Spinacia Oleracea L.)

Authors: Umar Jaafar, Mungadi

Abstract:

Plant growth, biochemical parameters, cytotoxic ion sequestration and ionic in balance were determined for spinach in response to varied concentrations of NaCl. The plant show decline in all vegetative parameters measured. Free proline content increase with increasing salt concentration and differ significantly (p<0.05) while the glycine betaine insignificantly (p>0.05) affected by concentration of NaCl. Salinity increases the cytotoxic ions, sodium chlorine ion and calcium with corresponding decrease in potassium ion concentrations. The ionic balance (Na+/K+) is low due to high content of potassium ion in plant accumulation ranging from 7700 to 6500 mg/kg. It can be concluded that the osmolyte accumulations, high number of leaves are possible indicators of salt tolerance in the spinach.

Keywords: spinach, salinity, osmolyte, cytotoxic

Procedia PDF Downloads 358
19445 Investigation for Pixel-Based Accelerated Aging of Large Area Picosecond Photo-Detectors

Authors: I. Tzoka, V. A. Chirayath, A. Brandt, J. Asaadi, Melvin J. Aviles, Stephen Clarke, Stefan Cwik, Michael R. Foley, Cole J. Hamel, Alexey Lyashenko, Michael J. Minot, Mark A. Popecki, Michael E. Stochaj, S. Shin

Abstract:

Micro-channel plate photo-multiplier tubes (MCP-PMTs) have become ubiquitous and are widely considered potential candidates for next generation High Energy Physics experiments due to their picosecond timing resolution, ability to operate in strong magnetic fields, and low noise rates. A key factor that determines the applicability of MCP-PMTs in their lifetime, especially when they are used in high event rate experiments. We have developed a novel method for the investigation of the aging behavior of an MCP-PMT on an accelerated basis. The method involves exposing a localized region of the MCP-PMT to photons at a high repetition rate. This pixel-based method was inspired by earlier results showing that damage to the photocathode of the MCP-PMT occurs primarily at the site of light exposure and that the surrounding region undergoes minimal damage. One advantage of the pixel-based method is that it allows the dynamics of photo-cathode damage to be studied at multiple locations within the same MCP-PMT under different operating conditions. In this work, we use the pixel-based accelerated lifetime test to investigate the aging behavior of a 20 cm x 20 cm Large Area Picosecond Photo Detector (LAPPD) manufactured by INCOM Inc. at multiple locations within the same device under different operating conditions. We compare the aging behavior of the MCP-PMT obtained from the first lifetime test conducted under high gain conditions to the lifetime obtained at a different gain. Through this work, we aim to correlate the lifetime of the MCP-PMT and the rate of ion feedback, which is a function of the gain of each MCP, and which can also vary from point to point across a large area (400 $cm^2$) MCP. The tests were made possible by the uniqueness of the LAPPD design, which allows independent control of the gain of the chevron stacked MCPs. We will further discuss the implications of our results for optimizing the operating conditions of the detector when used in high event rate experiments.

Keywords: electron multipliers (vacuum), LAPPD, lifetime, micro-channel plate photo-multipliers tubes, photoemission, time-of-flight

Procedia PDF Downloads 178
19444 Biochemical Evaluation of Air Conditioning West Water in Jeddah City: Concept of Sustainable Water Resources

Authors: D. Alromi, A. Alansari, S. Alghamdi, E. Jambi

Abstract:

As the need for water is increasing globally, and the available water resources are barely meeting the current quality of life and economy. Air conditioning (AC) condensate water could be explored as an alternative water source, which could be considered within the global calculations of the water supply. The objective of this study is to better understand the potential for recovery of condensate water from air conditioning systems. The results generated so far showed that the AC produces a high quantity of water, and data analysis revealed that the amount of water is positively and significantly correlated with the humidity (P <= 0.05). In the meantime, the amount of heavy metals has been measuring using ICP-OES. The results, in terms of quantity, clearly show that the AC can be used as an alternative source of water, especially in the regions characterized by high humidity. The results also showed that the amount of produced water depends on the type of AC.

Keywords: air conditioning systems, water quantity, water resources, wastewater

Procedia PDF Downloads 213
19443 The Effects of High Technology on Communicative Translation: A Case Study of Yoruba Language

Authors: Modupe Beatrice Adeyinka

Abstract:

European Languages are languages of literature, science and technology. Whereas, African languages are of literature, both written and oral, making it difficult for Yoruba, the African language of Kwa linguistic classification, to neatly and accurately translate European scientific and technological words, expressions and technologies. Unless a pragmatic and communicative approach is adopted, equivalence of European technical and scientific texts might be a mission impossible for Yoruba scholars. In view of the aforementioned difficult task, this paper tends to highlight the need for a thorough study and evaluation of English or French words, expressions, idiomatic expressions, technical and scientific terminologies then, trying to find ways of adopting them to Yoruba environment through interpretative translation.

Keywords: communication, high technology, translation, Yoruba language

Procedia PDF Downloads 513
19442 Reinforcing Fibre Reinforced Polymer (FRP) Bridge Decks with Steel Plates

Authors: M. Alpaslan Koroglu

Abstract:

Fibre reinforced polymer (FRP) bridge decks have become an innovative alternative, and they have offered many advantages, and this has been increasing attention for applications in not only reinforcement of existing bridges decks but also construction of new bridges decks. The advantages of these FRP decks are; lightweight, high-strength FRP materials, corrosion resistance. However, this high strength deck is not ductile. In this study, the behaviour of hybrid FRP-steel decks are investigated. All FRP decks was analysed with the commercial package ABAQUS. In the FE model, the webs and flanges were discretised by 4 nodes shell elements. A full composite action between the steel and the FRP composite was assumed in the FE analysis because the bond-slip behaviour was unknown at that time. The performance of the proposed hybrid FRP deck panel with steel plates was evaluated by means of FE analysis.

Keywords: FRP, deck, bridge, finite element

Procedia PDF Downloads 475
19441 Adsorption of Congo Red on MgO Nanoparticles Prepared by Molten Salt Method

Authors: Shahbaa F. Bdewi, Bakhtyar K. Aziz, Ayad A. R. Mutar

Abstract:

Nano-materials show different surface properties due to their high surface area and active sites. This study investigates the feasibility of using nano-MgO (NMO) for removing Congo red (CR) dye from wastewater. NMO was prepared by molten salt method. Equilibrium experiments show the equilibrium was reached after 120 minutes and maximum adsorption efficiency was obtained in acidic media up to pH 6. Isotherm studies revealed the favorability of the adsorption process. The overall adsorption process was spontaneous and endothermic in nature with a maximum adsorption capacity of 1100 mg g-1 at 40°C as estimated from Langmuir isotherm. The adsorption kinetics was found to follow pseudo second-order rate equation. Relatively high activation energy (180.7 kJ mol-1) was obtained which is consistent with chemisorption mechanism for the adsorption process.

Keywords: adsorption, congo red, magnesium oxide, nanoparticles

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19440 Analysis of Spectral Radiative Entropy Generation in a Non-Gray Participating Medium with Heat Source (Furnaces)

Authors: Asadollah Bahrami

Abstract:

In the present study, spectral radiative entropy generation is analyzed in a furnace filled with a mixture of H₂O, CO₂ and soot at radiative equilibrium. For the angular and spatial discretization of the radiative transfer equation and radiative entropy generation equations, the discrete ordinates method and the finite volume method are used, respectively. Spectral radiative properties are obtained using the correlated-k (CK) non-gray model with updated parameters based on the HITEMP2010 high-resolution database. In order to evaluate the effects of the location of the heat source, boundary condition and wall emissivity on radiative entropy generation, five cases are considered with different conditions. The spectral and total radiative entropy generation in the system are calculated for all cases and the effects of mentioned parameters on radiative entropy generation are attentively analyzed and finally, the optimum condition is especially presented. The most important results can be stated as follows: Results demonstrate that the wall emissivity has a considerable effect on the radiative entropy generation. Also, irreversible radiative transfer at the wall with lower temperatures is the main source of radiative entropy generation in the furnaces. In addition, the effect of the location of the heat source on total radiative entropy generation is less than other factors. Eventually, it can be said that characterizing the effective parameters of radiative entropy generation provides an approach to minimizing the radiative entropy generation and enhancing the furnace's performance practicality.

Keywords: spectral radiative entropy generation, non-gray medium, correlated k(CK) model, heat source

Procedia PDF Downloads 103
19439 The Influence of Workplace Aggression on Employee Turnover Intention

Authors: Nimra Parvez, Nawaz Ahmed

Abstract:

Workplace aggression not only is a proven safety and health issue but it also is a problem witnessed at workplace which has far-reaching consequences. It hinders the overall productivity of the organizations and individual employees. The current study examined employee turnover intentions as a result of workplace aggression. The study was conducted on employees from the private sector. Self-report questionnaires that measured the workplace aggression and turnover intentions of employees were used to target a sample size of 200 employees. In the hypothesis, it was assumed that high levels of workplace aggression at any organization will result in subsequent high levels of employee turnover intentions. It was therefore identified that there has been a relationship between workplace aggression and employee turnover intentions. The results determined a positive relationship between the workplace bullying behaviors towards the individuals and the turnover intention.

Keywords: bullying, organizational commitment, turnover intention, workplace aggression

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19438 Peer-Mediated Interventions as a High-Leverage Practice in Inclusive General Education Classrooms

Authors: Daniel Pyle, Nicole Pyle, Ben Lignugaris-Kraft, Lawrence Maheady

Abstract:

Students with disabilities are not included in general education at the same rate as their peers without disabilities. There are multiple reasons cited for why inclusion rates vary, such as teachers' lack of knowledge of the successful delivery of inclusive practices to students with the most extensive support needs. However, decades of research document effective inclusive practices associated with benefits across domains for students with disabilities. One effective inclusive practice that teachers use to improve outcomes for students with disabilities is flexible grouping. Teachers can use flexible grouping to facilitate students working collaboratively by using peer-mediated interventions (PMIs). This article describes PMIs as a flexible grouping of High Leverage Practices (HLP). There are variations of PMIs to select from when using flexible grouping. PMIs are described by varied grouping arrangements and different instructional procedures to clarify the flexibility of grouping students and students’ roles within those groupings. In support of teachers’ use of flexible grouping in inclusive general education classrooms, we identify different PMI formats teachers can use depending on the preferred grouping arrangement, explain the distinctive characteristics of PMI models to distinguish expected procedures with peers, highlight outcomes associated with PMIs, and provide an overview of evaluating PMIs effectiveness.

Keywords: peer-mediated interventions, high leverage practices, flexible grouping, general education, special education

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19437 Production of Date Juice Infused with Natural Antioxidants from Qatari Herbs

Authors: Tahra ElObeid, Noura Al-Wahiemed, Jawaher Al-shammari, Wedad Al-Asmar

Abstract:

The aim of this study is to utilize Qatari raw materials in the production of a date juice high in antioxidants. The antioxidants were extracted from five Qatari herbs: Caspian manna, Tetraena mongolica, Capparis spinosa, Ziziphus Vulgaris and Lycium shawii. The date juice was prepared in the lab and was infused with the polyphenolic extracts from the 5 different Qatari herbs. The date juice was then infused with the antioxidant containing the highest antioxidant activity and was within the acceptable range in sensory evaluation scale. The phenolic content for Lycium shawii, Alhagi maurorum, Ziziphus Vulgaris, Capparis spinosa and Tetraena mongolica was 4294 ppm, 3843 ppm, 804.59 ppm, 189.14 ppm and 226 ppm respectively, whereas their antioxidant capacity of was 6.21 %, 45.27 %, 69.81 %, 2.96 % and 8.63 % respectively. The highest antioxidant capacity was found in Ziziphus Vulgaris 69.8 % and the highest phenolic content was found in Lycium shawii 4294 ppm. Alhagi maurorum, Tetraena mongolica and Lycium shawii showed good results in terms of taste and aroma however Ziziphus Vulgaris exhibited bitter flavor. Alhagi maurorum antioxidant extract was used to be added to the date juice due to its high phenolic content, high antioxidant capacity, good taste and aroma.

Keywords: Qatar, dates, herbs, antioxidants

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19436 Land Use Sensitivity Map for the Extreme Flood Events in the Kelantan River Basin

Authors: Nader Saadatkhah, Jafar Rahnamarad, Shattri Mansor, Zailani Khuzaimah, Arnis Asmat, Nor Aizam Adnan, Siti Noradzah Adam

Abstract:

Kelantan river basin as a flood prone area at the east coast of the peninsular Malaysia has suffered several flood and mudflow events in the recent years. The current research attempted to assess the land cover changes impact in the Kelantan river basin focused on the runoff contributions from different land cover classes and the potential impact of land cover changes on runoff generation. In this regards, the hydrological regional modeling of rainfall induced runoff event as the improved transient rainfall infiltration and grid based regional model (Improved-TRIGRS) was employed to compute rate of infiltration, and subsequently changes in the discharge volume in this study. The effects of land use changes on peak flow and runoff volume was investigated using storm rainfall events during the last three decades.

Keywords: improved-TRIGRS model, land cover changes, Kelantan river basin, flood event

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19435 Use Cases Analysis of Free Space Optical Communication System

Authors: Kassem Saab, Fritzen Bart, Yves-Marie Seveque

Abstract:

The deployment of Free Space Optical Communications (FSOC) systems requires the development of robust and reliable Optical Ground Stations (OGS) that can be easily installed and operated. To this end, the Engineering Department of Airbus Defence and Space is actively working on the development of innovative and compact OGS solutions that can be deployed in various environments and provide high-quality connectivity under different atmospheric conditions. This article presents an overview of our recent developments in this field, including an evaluation study of different use cases of the FSOC with respect to different atmospheric conditions. The goal is to provide OGS solutions that are both simple and highly effective, allowing for the deployment of high-speed communication networks in a wide range of scenarios.

Keywords: end to end optical communication, laser propagation, optical ground station, turbulence

Procedia PDF Downloads 94
19434 Effect of the Nature of Silica Precursor in Zeolite ZSM-22 Synthesis

Authors: Nyiko M. Chauke, James Ramontja, Richard M. Moutloali

Abstract:

The zeolite ZSM-22 material demonstrated effective hydrophilic character as a nanoadditive filler in the preparation of nanocomposite membranes. In this study, nanorods ZSM-22 zeolite materials were hydrothermally synthesised from a homogenous gel mixture prepared using different silica precursors: colloidal silica, fumed silica, tetraethylorthosilicate (TEOS), and aluminium precursor: aluminium sulphate octadecahydrate (Al₂(SO₄)₃.18H₂O to Si/Al of 60. This was focused on developing a defect-free zeolite framework for effective use in applications such as membrane separation process, adsorption, and catalysis. The obtained ZSM-22 zeolite materials with 60 Si/Al ratio exhibits high crystallinity, hydrophilicity, and needle-like morphologies, suggesting successful synthesis as shown by X-ray Diffraction (XRD), Brunauer-Emmett-Teller (BET), Fourier-Transform Infrared Spectroscopy (FTIR), Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) physicochemical analysis. It was revealed that the use of different nature of silica precursors significantly influenced the properties of the final product and contributed to the development of defect-free zeolite material. As such, the crystalline nanorods of Theta-1 (TON) ZSM-22 obtained from TEOS silica showed high phase purity, defect-free, and narrow particle size distribution. Morphological analysis exhibited that the use of TEOS as silica precursor was effective than its counterparts and produced high crystalline need-like agglomerated particles.

Keywords: silica precursor, hydrothermal synthesis, zeolite material, ZSM-22

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19433 Delaunay Triangulations Efficiency for Conduction-Convection Problems

Authors: Bashar Albaalbaki, Roger E. Khayat

Abstract:

This work is a comparative study on the effect of Delaunay triangulation algorithms on discretization error for conduction-convection conservation problems. A structured triangulation and many unstructured Delaunay triangulations using three popular algorithms for node placement strategies are used. The numerical method employed is the vertex-centered finite volume method. It is found that when the computational domain can be meshed using a structured triangulation, the discretization error is lower for structured triangulations compared to unstructured ones for only low Peclet number values, i.e. when conduction is dominant. However, as the Peclet number is increased and convection becomes more significant, the unstructured triangulations reduce the discretization error. Also, no statistical correlation between triangulation angle extremums and the discretization error is found using 200 samples of randomly generated Delaunay and non-Delaunay triangulations. Thus, the angle extremums cannot be an indicator of the discretization error on their own and need to be combined with other triangulation quality measures, which is the subject of further studies.

Keywords: conduction-convection problems, Delaunay triangulation, discretization error, finite volume method

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19432 Hydraulics of 3D Aerators with Lateral Enlargements

Authors: Nirmala Lama

Abstract:

The construction of high dams has led to significant challenges in managing flow rates discharging over spillways, resulting in cavitation damages on hydraulic surfaces. To address this, aerator devices were designed and installed to promote fore aeration, thereby controlling and mitigating damages caused by cavitation. Consequently, these aerator types, three-dimensional aerators (3DAEs), have demonstrated superior efficiency in introducing forced air into the flow.This research focuses on the installation and evaluation of three-dimensional aerator devices at the high discharge spillway surface. In the laboratory, the air concentration downstream of the hydraulic structures was extensively measured, and the data were analyzed in details.Multiple flow scenarios and structural arrangements of the aerators were adopted for the study. The outcomes of these experiments are listed as In terms of air concentration value, the comparison between 3 DAE (three-dimensional aerator) with offset only and offset with ramp reveals significant differences. The concentration value on the side wall was justified. The side cavity length was found to increase with higher approach Froude numbers and lateral enlargement widths. Furthermore, 3DAE exhibited shorter side cavity lengths compared to three-dimensional aerator devices without ramps (3DAD), a beneficial features for controlling water fins. An empirical formula to express the side cavity length was derived from the measured data. Also, the comparison were made on the basis of water fin formation between the different arrangements of 3D aerators. In conclusion, this research provides valuable insights into the performance of three-dimensional aerators in mitigating cavitation damages and controlling water fins in high dam spillways. The findings offer practical implications for designers and engineers seeking to enhance the efficiency and safety of hydraulic structures subjected to high flow rates.

Keywords: three-dimension aerator, cavity, water fin, air entrainment

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19431 Cholesterol Modulating Properties of a Proprietary Extract from Phyllanthus spp on Hypercholesteraemic Mice Models

Authors: Anne R. Fernandez, Mohammad Akmal Adnan, Tanes Prasat, Indu Bala Jaganath, Brian Kirby, Kamalan Jeevaratnam

Abstract:

Introduction: Plants from the Phyllantus genus have been used indigenously for the treatment of a variety of ailments for generations. A cocktail of phytonutrients prepared from a plant of the genus Phyllanthus has demonstrated the potential to alleviate ailments which include cardiovascular disorders. In this study, we investigated the cholesterol modulating properties of a highly purified proprietary extract of a Phyllanthus species in hypercholesteraemic mice. Methods: Hypercholesteraemia was induced in ICR mice by ad-libitum feeding of high fat diet daily for six weeks. The mice were then divided into 3 groups and force fed with 10mg/kg of atorvastatin, 200mg/kg of the proprietary Phyllanthus extract and water respectively. Blood samples were taken at the end of fourth week of treatment by a tail prick. At the end of the eighth week of treatment, mice were sacrificed and serum levels of total cholesterol, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and triglycerides were measured. Results: The mean cholesterol levels in the mice fed with high fat diet were 44% (p < 0.05) higher than the mice on normal diet thus validating the model developed. The plasma HDL was significantly elevated in mice treated with the formulation (p ˂ 0.05) in comparison to the statin-treated and control mice. The total cholesterol levels in the mice treated with the proprietary extract were reduced significantly (p < 0.05) at the end of 4 weeks of treatment in comparison to the mice treated with atorvastatin. By the end of 8 weeks of treatment, there was no significant difference in the cholesterol levels of the mice in all groups. Conclusion: These results demonstrate that this proprietary extract from Phyllanthus species has the beneficial effect of reducing total cholesterol level more rapidly than atorvastatin and increasing HDL levels. Since an increase in the HDL cholesterol can reduce the risk of heart disease, this proprietary extract is a useful and safe therapeutic option compared to atorvastatin.

Keywords: high-density lipoprotein, hypercholesteraemic mice model, ICR mice, Phyllanthus spp.

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19430 A Pragma-Rhetorical Study of Christian Religious Pentecostal Sermons in Nigeria

Authors: Samuel Alaba Akinwotu

Abstract:

Effectiveness in communication requires the deployment of pragmatic and rhetorical strategies in religious sermons. In spite of high volume of works in religious discourse, scholars have not adequately accounted for the persuasive and argumentation strategies employed in Christian religious Pentecostal sermons. This study examines communicative intentions and the pragma-rhetorical strategies deployed to maintain balance and effectiveness in selected sermons of Pastor E. A. Adeboye, Bishop D. Oyedepo and Pastor W. F. Kumuyi. Fifteen sermons, delivered orally and transcribed into the written mode, were selected and analysed using Jacob Mey’s theory of pragmeme, Aristotle’s rhetoric and the theory of argumentation by van Eemeren and Grootendorst. Speakers pract stating, encouraging, assuring, warning, condemning, directing, praising, thanking, etc. through rhetorical question, repetition, direct address, direct command and structural parallelism. They assume divine role by speaking authoritatively and they tactically and logically select words to legitimise their ideology. They also categorise and portray individuals and/or issues either as good or bad, sinner/sin or righteous/righteousness, etc. The study provides clearer insight into the pragmatic import and the communicative effectiveness of Christian Pentecostal sermons. Further research can juxtapose the pragma-rhetorical and argumentation strategies of preachers of two clearly differentiated movements within the Christian religion.

Keywords: argumentation, communicative intentions, pentecostal sermons, pragmeme, rhetoric

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19429 Copper Doped P-Type Nickel Oxide Transparent Conducting Oxide Thin Films

Authors: Kai Huang, Assamen Ayalew Ejigu, Mu-Jie Lin, Liang-Chiun Chao

Abstract:

Nickel oxide and copper-nickel oxide thin films have been successfully deposited by reactive ion beam sputter deposition. Experimental results show that nickel oxide deposited at 300°C is single phase NiO while best crystalline quality is achieved with an O_pf of 0.5. XRD analysis of nickel-copper oxide deposited at 300°C shows a Ni2O3 like crystalline structure at low O_pf while changes to NiO like crystalline structure at high O_pf. EDS analysis shows that nickel-copper oxide deposited at low O_pf is CuxNi2-xO3 with x = 1, while nickel-copper oxide deposited at high O_pf is CuxNi1-xO with x = 0.5, which is supported by Raman analysis. The bandgap of NiO is ~ 3.5 eV regardless of O_pf while the band gap of nickel-copper oxide decreases from 3.2 to 2.3 eV as Opf reaches 1.0.

Keywords: copper, ion beam, NiO, oxide, resistivity, transparent

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