Search results for: contact angle

Authors: Lukasz Grabowski, Konrad Pietrykowski, Michal Bialy

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This paper presents the results of the research to verify the combustion in aircraft piston engine Asz62-IR. This engine was modernized and a type of ignition system was developed. Due to the high costs of experiments of a nine-cylinder 1,000 hp aircraft engine, a simulation technique should be applied. Therefore, computational fluid dynamics to simulate the combustion process is a reasonable solution. Accordingly, the tests for varied ignition advance angles were carried out and the optimal value to be tested on a real engine was specified. The CFD model was created with the AVL Fire software. The engine in the research had two spark plugs for each cylinder and ignition advance angles had to be set up separately for each spark. The results of the simulation were verified by comparing the pressure in the cylinder. The courses of the indicated pressure of the engine mounted on a test stand were compared. The real course of pressure was measured with an optical sensor, mounted in a specially drilled hole between the valves. It was the OPTRAND pressure sensor, which was designed especially to engine combustion process research. The indicated pressure was measured in cylinder no 3. The engine was running at take-off power. The engine was loaded by a propeller at a special test bench. The verification of the CFD simulation results was based on the results of the test bench studies. The course of the simulated pressure obtained is within the measurement error of the optical sensor. This error is 1% and reflects the hysteresis and nonlinearity of the sensor. The real indicated pressure measured in the cylinder and the pressure taken from the simulation were compared. It can be claimed that the verification of CFD simulations based on the pressure is a success. The next step was to research on the impact of changing the ignition advance timing of spark plugs 1 and 2 on a combustion process. Moving ignition timing between 1 and 2 spark plug results in a longer and uneven firing of a mixture. The most optimal point in terms of indicated power occurs when ignition is simultaneous for both spark plugs, but so severely separated ignitions are assured that ignition will occur at all speeds and loads of engine. It should be confirmed by a bench experiment of the engine. However, this simulation research enabled us to determine the optimal ignition advance angle to be implemented into the ignition control system. This knowledge allows us to set up the ignition point with two spark plugs to achieve as large power as possible.

Keywords: CFD model, combustion, engine, simulation

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Authors: Chanchal Biswas, Anrin Bhattacharyya, Gopes Chandra Das, Mahua Ghosh Chaudhuri, Rajib Dey

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Boiler coals with low fixed carbon and higher ash content have always challenged the metallurgists to develop a suitable method for their utilization. In the present study, an attempt is made to establish an energy effective method for the reduction of iron ore fines in the form of nuggets by using ‘Syngas’. By devolatisation (expulsion of volatile matter by applying heat) of boiler coal, gaseous product (enriched with reducing agents like CO, CO2, H2, and CH4 gases) is generated. Iron ore nuggets are reduced by this syngas. For that reason, there is no direct contact between iron ore nuggets and coal ash. It helps to control the minimization of the sulphur intake of the reduced nuggets. A laboratory scale devolatisation furnace designed with reduction facility is evaluated after in-depth studies and exhaustive experimentations including thermo-gravimetric (TG-DTA) analysis to find out the volatile fraction present in boiler grade coal, gas chromatography (GC) to find out syngas composition in different temperature and furnace temperature gradient measurements to minimize the furnace cost by applying one heating coil. The nuggets are reduced in the devolatisation furnace at three different temperatures and three different times. The pre-reduced nuggets are subjected to analytical weight loss calculations to evaluate the extent of reduction. The phase and surface morphology analysis of pre-reduced samples are characterized using X-ray diffractometry (XRD), energy dispersive x-ray spectrometry (EDX), scanning electron microscopy (SEM), carbon sulphur analyzer and chemical analysis method. Degree of metallization of the reduced nuggets is 78.9% by using boiler grade coal. The pre-reduced nuggets with lesser sulphur content could be used in the blast furnace as raw materials or coolant which would reduce the high quality of coke rate of the furnace due to its pre-reduced character. These can be used in Basic Oxygen Furnace (BOF) as coolant also.

Keywords: alternative ironmaking, coal gasification, extent of reduction, nugget making, syngas based DRI, solid state reduction

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Authors: Deepa Kundu, Prabhakar Sharma, Sayan Bhattacharya, Jianying Shang

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The discharge of dye-containing effluents in the water bodies has raised concern due to the potential hazards related to their toxicity in the environment. There are various treatment technologies available for the removal of dyes from wastewaters. The use of biosorbent to remove dyes from wastewater is one of the effective and inexpensive techniques. In the study, the adsorption of phenothiazine dye methylene blue onto biosorbent prepared from Lantana camara L. has been studied in aqueous solutions. The batch adsorption experiments were conducted and the effects of various parameters such as pH (3-12), contact time, adsorbent dose (100-400 mg/L), initial dye concentration (5-20 mg/L), and temperature (303, 313 and 323 K) were investigated. The prepared leaf (BCL600) and shoot (BCS600) biochar of Lantana were characterized using FTIR, SEM, elemental analysis, and zeta potential (pH~7). A comparison between the adsorption potential of both the biosorbent was also evaluated. The results indicated that the amount of methylene blue dye (mg/g) adsorbed onto the surface of biochar was highly dependent on the pH of the dye solutions as it increased with an increase in pH from 3 to 12. It was observed that the dye treated with BCS600 and BCL600 attained an equilibrium within 60 and 100 minutes, respectively. The rate of the adsorption process was determined by performing the Lagergren pseudo-first-order and pseudo-second-order kinetics. It was found that dye treated with both BCS600 and BCL600 followed pseudo-second-order kinetics implying the multi-step nature of the adsorption process involving external adsorption and diffusion of dye molecules into the interior of the adsorbents. The data obtained from batch experiments were fitted well with Langmuir and Freundlich isotherms (R² > 0.98) to indicate the multilayer adsorption of dye over the biochar surfaces. The thermodynamic studies revealed that the adsorption process is favourable, spontaneous, and endothermic in nature. Based on the results, the inexpensive and easily available Lantana camara biomass can be used to remove methylene blue dye from wastewater. It can also help in managing the growth of the notorious weed in the environment.

Keywords: adsorption kinetics, biochar, Lantana camara, methylene blue dye, possible mechanism, thermodynamics

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Authors: Chun-Lin Zhang, Min Wan

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With the upgrade development of the tourism industry from the simple sightseeing tour to the leisure and vacation, people's travel idea has undergone a fundamental change. More and more people begin to pursue liberal and personal tourism, so self-driving tourism has become the main form of current tourism activities. With the self-driving tourism representing the general trend, the importance of convenient tourism transportation and perfect road traffic signs have become more and more prominent. A clear urban road traffic signs can help visitors quickly identify the direction and distance to the tourism destination. The purpose of this article is analyzing the planning of urban road traffic signs which can bring positive impact on the participation in the recreation involved of self-driving tourists. The content of this article is divided into three parts. Based on the literature review and theoretical analysis, the first part constructs a structural variance model. The model is from three dimensions: the attention of the self-driving tourists to the urban traffic signs along the road, the perception of the self-driving tourists to the road traffic signs itself, the perceptions of the self-driving tourists to the tourism destination information on the traffic signs. Through this model, the paper aims to explore the influence of the urban road traffic signs to the leisure psychological involvement and leisure behavior involvement of the self-driving tourists. The second part aims to verify through the hypothesis model the questionnaire survey and come to preliminary conclusions. The preliminary conclusions are as follows: firstly, the color, shape, size, setting mode and occurrence frequency of urban road traffic sign have significant influence on the leisure psychological involvement and leisure behavior involvement of the self-driving tourists. Secondly, the influence on the leisure behavior involvement is obviously higher than the influence on the leisure psychological involvement. Thirdly, the information about the tourism destination marked on the urban road traffic signs has not obviously influence on the leisure psychological involvement, but it has distinct influence on the leisure behavior involvement of self-driving tourists. The third part puts forward that the planning of urban road traffic signs should focus on the angle of the impact of road traffic signs on people's psychology and behavior. On the basis of the above conclusions, the paper researches the color, shape, size, setting mode and information labeling of urban road traffic signs so that they can preferably satisfy the demand of the leisure involvement of self-driving tourists.

Keywords: leisure involvement, self-driving tourism, structural equation, urban road traffic signs

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Authors: Ashraf Mohammadzadeh, Ahmad Shah Farhat, Azin Vaezi, Aradokht Vaezi

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Background & Aim: Preterm infants born at less than 34 weeks postconceptional age are not as neurologically mature as their term counterparts and thus have difficulty coordinating sucking, swallowing and breathing. As a result, they are traditionally gavage fed until they are able to oral feed successfully. The aim of study was to evaluate comparative effect of orogastric and breast feeding on oxygen saturation in very low birth weight infant (<1500gm). Patients and Methods: In this clinical trial all babies admitted in the Neonatal Research Center of Imamreza Hospital, Mashhad during a 4 months period were elected. Criteria for entrance to study included birth weight ≤ 1500 grams, exclusive breastfeeding, having no special problem after 48 hours, receivinge only routine care and intake of milk was 100cc/kg/day. Each neonate received two rounds of orogastric and breast feeding in the morning and in the afternoon, during which mean oxygen saturation was measured by pulse-oxymetry. During the study the heart rate and temperature of the neonates were monitored, and in case of hypothermia, bradycardia(less than 100 per minute) or apnea the feeding was discontinued and the study was repeated the following day. Data analysis was carried out using SPSS. Results: Fifty neonates were studied. The average birth weight was 1267.20±165.42 grams and average gestational age was 31.81±1.92 and female/male ratio was 1.2. There was no significant statistical difference in arterial oxygen saturation in orogastric and breast feeding in the morning and in the afternoon. (p=0.16 in the morning and p=0.6 in the afternoon). There was no complication of apnea, hypothermia or bradycardia. Conclusion: There was no significant statistical difference between the two methods in arterial oxygen saturation. It seems that oral feeding (which is a natural route) and skin contact between the mother and neonate causes a strong emotional bonding between the two and brings about better social adaptation for the neonate. Also shorter period of stay in hospital is more preferred, and breast feeding should be started at the earliest possible time after birth.

Keywords: Very low birth weight (V.L.B.W), O2 Saturation, Breast Feeding, Tube Feeding

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Authors: F. Abdelhamid

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Algeria is a multilingual speech community where individuals constantly mix between codes in spoken discourse. Code is used as a cover term to refer to the existing languages and language varieties which include, among others, the mother tongue of the majority Algerian Arabic, the official language Modern Standard Arabic and the foreign languages French and English. The present study explores whether Algerians mix between these codes in online communication as well. Facebook is the selected platform from which data is collected because it is the preferred social media site for most Algerians and it is the most used one. Adopting the notion of translanguaging, this study attempts explaining how users of Facebook use multilingual messages to communicate meaning. Accordingly, multilingual interactions are not approached from a pejorative perspective but rather as a creative linguistic behavior that multilingual utilize to achieve intended meanings. The study is intended as a contribution to the research on multilingualism online because although an extensive literature has investigated multilingualism in spoken discourse, limited research investigated it in the online one. Its aim is two-fold. First, it aims at ensuring that the selected platform for analysis, namely Facebook, could be a source for multilingual data to enable the qualitative analysis. This is done by measuring frequency rates of multilingual instances. Second, when enough multilingual instances are encountered, it aims at describing and interpreting some selected ones. 120 posts and 16335 comments were collected from two Facebook pages. Analysis revealed that third of the collected data are multilingual messages. Users of Facebook mixed between the four mentioned codes in writing their messages. The most frequent cases are mixing between Algerian Arabic and French and between Algerian Arabic and Modern Standard Arabic. A focused qualitative analysis followed where some examples are interpreted and explained. It seems that Algerians mix between codes when communicating online despite the fact that it is a conscious type of communication. This suggests that such behavior is not a random and corrupted way of communicating but rather an intentional and natural one.

Keywords: Algerian speech community, computer mediated communication, languages in contact, multilingualism, translanguaging

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Authors: Firas Daghistani, Hossam Abuel Naga

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Waste tyres is a global problem that has a negative effect on the environment, where there are approximately one billion waste tyres discarded worldwide yearly. Waste tyres are discarded in stockpiles, where they provide harm to the environment in many ways. Finding applications to these materials can help in reducing this global problem. One of these applications is recycling these waste materials and using them in geotechnical engineering. Recycled waste tyre particulates can be mixed with sand to form a lightweight material with varying shear strength characteristics. Contradicting results were found in the literature on the inclusion of particulate rubber to sand, where some experiments found that the inclusion of particulate rubber can increase the shear strength of the mixture, while other experiments stated that the addition of particulate rubber decreases the shear strength of the mixture. This research further investigates the inclusion of particulate rubber to sand and whether it can increase or decrease the shear strength characteristics of the mixture. For the experiment, a series of direct shear tests were performed on a poorly graded sand with a mean particle size of 0.32 mm mixed with recycled poorly graded particulate rubber with a mean particle size of 0.51 mm. The shear tests were performedon four normal stresses 30, 55, 105, 200 kPa at a shear rate of 1 mm/minute. Different percentages ofparticulate rubber content were used in the mixture i.e., 10%, 20%, 30% and 50% of sand dry weight at three density states, namely loose, slight dense, and dense state. The size ratio of the mixture,which is the mean particle size of the particulate rubber divided by the mean particle size of the sand, was 1.59. The results identified multiple parameters that can influence the shear strength of the mixture. The parameters were: normal stress, particulate rubber content, mixture gradation, mixture size ratio, and the mixture’s density. The inclusion of particulate rubber tosand showed a decrease to the internal friction angle and an increase to the apparent cohesion. Overall, the inclusion of particulate rubber did not have a significant influenceon the shear strength of the mixture. For all the dense states at the low normal stresses 33 and 55 kPa, the inclusion of particulate rubber showed aslight increase in the shear strength where the peak was at 20% rubber content of the sand’s dry weight. On the other hand, at the high normal stresses 105, and 200 kPa, there was a slight decrease in the shear strength.

Keywords: shear strength, direct shear, sand-rubber mixture, waste material, granular material

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Authors: Ajith Kumar S., Sankaran Namboothiri, Sankrish J., SarathKumar S., S. Anil Lal

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A numerical analysis of flow over a heated circular cylinder is done in this paper. The governing equations, Navier-Stokes, and energy equation within the Boussinesq approximation along with continuity equation are solved using hybrid FEM-FVM technique. The density gradient created due to the heating of the cylinder will induce buoyancy force, opposite to the direction of action of acceleration due to gravity, g. In the present work, the flow direction and the direction of buoyancy force are taken as same (vertical flow configuration), so that the buoyancy force accelerates the mean flow past the cylinder. The relative dominance of the buoyancy force over the inertia force is characterized by the Richardson number (Ri), which is one of the parameter that governs the flow dynamics and heat transfer in this analysis. It is well known that above a certain value of Reynolds number, Re (ratio of inertia force over the viscous forces), the unsteady Von Karman vortices can be seen shedding behind the cylinder. The shedding wake patterns could be seriously altered by heating/cooling the cylinder. The non-dimensional shedding frequency called the Strouhal number is found to be increasing as Ri increases. The aerodynamic force coefficients CL and CD are observed to change its value. In the present vertical configuration of flow over the cylinder, as Ri increases, shedding frequency gets increased and suddenly drops down to zero at a critical value of Richardson number. The unsteady vortices turn to steady standing recirculation bubbles behind the cylinder after this critical Richardson number. This phenomenon is well known in literature as "Breakdown of the Karman Vortex Street". It is interesting to see the flow structures on further increase in the Richardson number. On further heating of the cylinder surface, the size of the recirculation bubble decreases without loosing its symmetry about the horizontal axis passing through the center of the cylinder. The separation angle is found to be decreasing with Ri. Finally, we observed a second critical Richardson number, after which the the flow will be attached to the cylinder surface without any wake behind it. The flow structures will be symmetrical not only about the horizontal axis, but also with the vertical axis passing through the center of the cylinder. At this stage, there will be a "single plume" emanating from the rear stagnation point of the cylinder. We also observed the transition of the plume is a strong function of the Richardson number.

Keywords: drag reduction, flow over circular cylinder, flow control, mixed convection flow, vortex shedding, vortex breakdown

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Authors: Niaz Gharavi, Hexin Zhang

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In the structural timber design, the shear modulus of the timber beam is an important factor that needs to be determined accurately. According to BS EN 408, shear modulus can be determined using torsion test or shear field test method. Although torsion test creates pure shear status in the beam, it does not represent the real-life situation when the beam is in the service. On the other hand, shear field test method creates similar loading situation as in reality. The latter method is based on shear distortion measurement of the beam at the zone with the constant transverse load in the standardized four-point bending test as indicated in BS EN 408. Current testing practice code advised using two metallic arms act as an instrument to measure the diagonal displacement of the constructing square. Timber is not a homogenous material, but a heterogeneous and this characteristic makes timber to undergo a non-uniform deformation. Therefore, the dimensions and the location of the constructing square in the area with the constant transverse force might alter the shear modulus determination. This study aimed to investigate the impact of the shape, size, and location of the square in the shear field test method. A binocular stereo vision system was developed to capture the 3D displacement of a grid of target points. This approach is an accurate and non-contact method to extract the 3D coordination of targeted object using two cameras. Two group of three glue laminated beams were produced and tested by the mean of four-point bending test according to BS EN 408. Group one constructed using two materials, laminated bamboo lumber and structurally graded C24 timber and group two consisted only structurally graded C24 timber. Analysis of Variance (ANOVA) was performed on the acquired data to evaluate the significance of size and location of the square in the determination of shear modulus of the beam. The results have shown that the size of the square is an affecting factor in shear modulus determination. However, the location of the square in the area with the constant shear force does not affect the shear modulus.

Keywords: shear field test method, BS EN 408, timber shear modulus, photogrammetry approach

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Authors: Manisha Choudhary, Sudarsan Neogi

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Malachite green (MG), an organic basic dye, has been widely used for the dyeing purpose, as well as a fungicide and antiseptic in aquaculture industry to control fish parasites and disease. However, MG has now turned out to be an extremely controversial compound due to its adverse impact on living beings. Due to high toxicity, proper treatment of wastewater containing MG is utmost important. Among different available technologies, adsorption process is one of the most efficient and cost-effective treatment method due to its simplicity of design, ease of operation and regeneration of used materials. Nonetheless, commercial activated carbon is expensive leading the researchers to focus on utilizing natural resources. In the present work, a species of cactus, Opuntia ficus-indica (OFI), was used to develop a highly efficient, low-cost powdered activated carbon by chemical activation using NaOH. The biosorbent was characterized by Fourier-transform infrared spectroscopy, field emission scanning electron microscope, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller (BET) and X-ray diffraction analysis. Batch adsorption studies were performed to remove MG from an aqueous solution as a function of contact time, initial solution pH, initial dye concentration, biosorbent dosages, the presence of salt and temperature. By increasing the initial dye concentration from 100 to 500 mg/l, adsorption capacity increased from 165.45 to 831.58 mg/g. The adsorption kinetics followed the pseudo-second-order model and the chemisorption mechanisms were revealed. The electrostatic attractions and chemical interactions were observed between amino and hydroxyl groups of the biosorbent and amine groups of the dye. The adsorption was solely controlled by film diffusion. Different isotherm models were used to fit the adsorption data. The excellent recovery of adsorption efficiency after the regeneration of biosorbent indicated the high potential of this adsorbent to remove MG from aqueous solution and an excellent cost-effective biosorbent for wide application in wastewater treatment.

Keywords: adsorption, biosorbent, cactus, malachite green

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Authors: Zemenu Yohannes

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Introduction: The pandemic overstretched the weak health systems in developing countries, including Ethiopia. This study aims to assess and explore the effect of COVID-19 on antenatal care (ANC) provision. Methods: A concurrent mixed methods study was applied. An interrupted time series design was applied for the quantitative study, and in-depth interviews were implemented for the qualitative research to explore maternity care providers' perceptions of ANC provision during COVID-19. We used routine monthly collected data from the health management information system (HMIS) in fifteen hospitals in the Sidama region, Ethiopia, from March 2019 to February 2020 (12 months) before COVID-19 and from March to August 2020 (6 months) during COVID-19. We imported data into STATA V.17 for analysis. ANC provision's mean monthly incidence rate ratio (IRR) was calculated using Poisson regression with a 95% confidence interval. The qualitative data were analysed using thematic analysis. Findings from quantitative and qualitative elements were integrated with a contiguous approach. Results: Our findings indicate the rate of ANC provision significantly decreased in the first six months of COVID-19. This study has three identified main themes: barriers to ANC provision, inadequate COVID-19 prevention approach, and delay in providing ANC. Conclusion and recommendation: Based on our findings, the pandemic affected ANC provision in the study area. The health bureau and stakeholders should take a novel and sustainable approach to prevent future pandemics. The health bureau and hospital administrators should establish a task force that relies on financial self-reliance to close gaps in future pandemics of medical supply shortages. Pregnant women should receive their care promptly from maternity care providers. In order to foster contact and avoid discrimination the future pandemics, hospital administrators should set up a platform for community members and maternity care providers.

Keywords: ANC provision, COVID-19, mixed methods study, Ethiopia

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Authors: Mahfouz Saeed

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Cu₂(ZnSn)(S)₄ (CTZS) offers potential advantages over CuInGaSe₂ (CIGS) as solar thin film because to its higher band gap. Preparing such photovoltaic materials by electrochemical techniques is particularly attractive due to the lower processing cost and the high throughput of such techniques. Several recent publications report CTZS electroplating; however, the electrochemical process still facing serious challenges such as a sulfur atomic ration which is about 50% of the total alloy. We introduce in this work an improved electrolyte composition which enables the direct electrodeposition of CTZS from a single bath. The electrolyte is significantly more dilute in comparison to common baths described in the literature. The bath composition we introduce is: 0.0032 M CuSO₄, 0.0021 M ZnSO₄, 0.0303 M SnCl₂, 0.0038 M Na₂S₂O₃, and 0.3 mM Na₂S₂O3. PHydrion is applied to buffer the electrolyte to pH=2, and 0.7 M LiCl is applied as supporting electrolyte. Electrochemical process was carried at a rotating disk electrode which provides quantitative characterization of the flow (room temperature). Comprehensive electrochemical behavior study at different electrode rotation rates are provided. The effects of agitation on atomic composition of the deposit and its adhesion to the molybdenum back contact are discussed. The post treatment annealing was conducted under sulfur atmosphere with no need for metals addition from the gas phase during annealing. The potential which produced the desired atomic ratio of CTZS at -0.82 V/NHE. Smooth deposit, with uniform composition across the sample surface and depth was obtained at 500 rpm rotation speed. Final sulfur atomic ratio was adjusted to 50.2% in order to have the desired atomic ration. The final composition was investigated using Energy-dispersive X-ray spectroscopy technique (EDS). XRD technique used to analyze CTZS crystallography and thickness. Complete and functional CTZS PV devices were fabricated by depositing all the required layers in the correct order and the desired optical properties. Acknowledgments: Case Western Reserve University for the technical help and for using their instruments.

Keywords: photovoltaic, CTZS, thin film, electrochemical

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Authors: Mohammad R. Jalali, Mohammad M. Jalali

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The earliest theories of sloshing waves and solitary waves based on potential theory idealisations and irrotational flow have been extended to be applicable to more realistic domains. To this end, the computational fluid dynamics (CFD) methods are widely used. Three-dimensional CFD methods such as Navier-Stokes solvers with volume of fluid treatment of the free surface and Navier-Stokes solvers with mappings of the free surface inherently impose high computational expense; therefore, considerable effort has gone into developing depth-averaged approaches. Examples of such approaches include Green–Naghdi (GN) equations. In Cartesian system, GN velocity profile depends on horizontal directions, x-direction and y-direction. The effect of vertical direction (z-direction) is also taken into consideration by applying weighting function in approximation. GN theory considers the effect of vertical acceleration and the consequent non-hydrostatic pressure. Moreover, in GN theory, the flow is rotational. The present study illustrates the application of GN equations to propagation of sloshing waves and solitary waves. For this purpose, GN equations solver is verified for the benchmark tests of Gaussian hump sloshing and solitary wave propagation in shallow basins. Analysis of the free surface sloshing of even harmonic components of an initial Gaussian hump demonstrates that the GN model gives predictions in satisfactory agreement with the linear analytical solutions. Discrepancies between the GN predictions and the linear analytical solutions arise from the effect of wave nonlinearities arising from the wave amplitude itself and wave-wave interactions. Numerically predicted solitary wave propagation indicates that the GN model produces simulations in good agreement with the analytical solution of the linearised wave theory. Comparison between the GN model numerical prediction and the result from perturbation analysis confirms that nonlinear interaction between solitary wave and a solid wall is satisfactorilly modelled. Moreover, solitary wave propagation at an angle to the x-axis and the interaction of solitary waves with each other are conducted to validate the developed model.

Keywords: Green–Naghdi equations, nonlinearity, numerical prediction, sloshing waves, solitary waves

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Authors: Souhila Belabbas

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This paper focuses on the Kabyles’ multilingual practices in the UK, within the Kabyle/Amazigh Cultural Organisation in London, on online platforms and at home. The Kabyles have roots in northern Algeria and associate their language, Kabyle, with a pre-Arabized history of northern Africa. Drawing on ethnographic research with this community, this study brings together their post-migration language preservation activisms as well as their dynamic multilingual practices and situational language choice into a dialogue. This shows the enduring significance of the heritage language for social, cultural and historical identity. It also demonstrates that the current survival of the “mother tongue” hinges on multilingual and multi-sited language activisms, which bear the hallmarks of both new creativities and diminishing fluencies in multilingual spaces. These multilingual repertoires also included a range of ideological stances, expressed as cultural, moral, and political attitudes to the “mother tongue” and to other, potentially more dominant, languages in their lives, involving both inclusive and exclusive instances. The Kabyles in the UK practice everyday forms of multilingualism in the dynamic terms whilst making strong identity claims to an endangered heritage language. Crucially, their language contact experiences were not a post-migration novelty but part of their pre-migration lifeworlds. The participants involved in this study shared a commitment to Kabyle identity activism. They expressed this differently, varyingly foregrounding cultural, social or political issues. These differences were related to their North-African cultural background, live, gender, religious and/or political affiliation, as well as to their different migratory trajectories. Among these ethno-conscious individuals, the use of Kabyle was often particularly vibrant in informal domains of casual conversations and mixed in with French, English and often Arabic. During community events and festivals, though, many made special efforts to converse in Kabyle as if to make a point about their commitment to a shared identity.

Keywords: ethnography, language ideology, language choice, heritage language, migration trajectories, multilingual repertoires

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Authors: Souhila Belabbas

Abstract:

This paper focuses on the Kabyles’ multilingual practices in the UK, within the Kabyle/Amazigh Cultural Organisation in London, on online platforms and at home. The Kabyles have roots in northern Algeria and associate their language, Kabyle, with a pre-Arabized history of northern Africa. Drawing on ethnographic research with this community, this study brings together their post-migration language preservation activisms as well as their dynamic multilingual practices and situational language choice into a dialogue. This shows the enduring significance of the heritage language for social, cultural and historical identity. It also demonstrates that the current survival of the “mother tongue” hinges on multilingual and multi-sited language activisms, which bear the hallmarks of both new creativities and diminishing fluencies in multilingual spaces. These multilingual repertoires also included a range of ideological stances, expressed as cultural, moral, and political attitudes to the “mother tongue” and to other, potentially more dominant, languages in their lives, involving both inclusive and exclusive instances. The Kabyles in the UK practice everyday forms of multilingualism in the dynamic terms whilst making strong identity claims to an endangered heritage language. Crucially, their language contact experiences were not a post-migration novelty but part of their pre-migration lifeworlds. The participants involved in this study shared a commitment to Kabyle identity activism. They expressed this differently, varyingly foregrounding cultural, social or political issues. These differences were related to their North-African cultural background, live, gender, religious and/or political affiliation, as well as to their different migratory trajectories. Among these ethno-conscious individuals, the use of Kabyle was often particularly vibrant in informal domains of casual conversations and mixed in with French, English and often Arabic. During community events and festivals, though, many made special efforts to converse in Kabyle as if to make a point about their commitment to a shared identity.

Keywords: ethnography, language ideology, language choice, heritage language, migration trajectories, multilingual repertoires

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Authors: Seyedeh Mozhgan Seyed-Talebi, Javad Beheshtian

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The toxicity of lead associated with the lifecycle of perovskite solar cells (PSCs( is a serious concern which may prove to be a major hurdle in the path toward their commercialization. The current proposed lead-free PSCs including Ag(I), Bi(III), Sb(III), Ti(IV), Ge(II), and Sn(II) low-toxicity cations are still plagued with the critical issues of poor stability and low efficiency. This is mainly because of their chemical stability. In the present research, utilization of all inorganic CsSnGeI₃ based materials offers the advantages to enhance resistance of device to degradation, reduce the cost of cells, and minimize the carrier recombination. The presence of inorganic halide perovskite improves the photovoltaic parameters of PCSs via improved surface coverage and stability. The inverted structure of simulated devices using a 1D simulator like solar cell capacitance simulator (SCAPS) version 3308 involves TCOHTL/Perovskite/ETL/Au contact layer. PEDOT:PSS, PCBM, and CsSnGeI₃ used as hole transporting layer (HTL), electron transporting layer (ETL), and perovskite absorber layer in the inverted structure for the first time. The holes are injected from highly stable and air tolerant Sn_0.5Ge_0.5I₃ perovskite composition to HTM and electrons from the perovskite to ETL. Simulation results revealed a great dependence of power conversion efficiency (PCE) on the thickness and defect density of perovskite layer. Here the effect of an increase in operating temperature from 300 K to 400 K on the performance of CsSnGeI₃ based perovskite devices is investigated. Comparison between simulated CsSnGeI₃ based PCSs and similar real testified devices with spiro-OMeTAD as HTL showed that the extraction of carriers at the interfaces of perovskite absorber depends on the energy level mismatches between perovskite and HTL/ETL. We believe that optimization results reported here represent a critical avenue for fabricating the stable, low-cost, efficient, and eco-friendly all-inorganic Cs-Sn-Ge based lead-free perovskite devices.

Keywords: hole transporting layer, lead-free, perovskite solar cell, SCAPS-1D, Sn-Ge based

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Authors: Nirav Jadav, M. G.Vanza

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Black cotton soils mainly exhibit the property of swelling/shrinkage when they react to moisture variations. This property causes development of cracks in the structures resting on these soils, which poses instability to the structures. Soil stabilization is a technique to enhance the geotechnical characteristics of Black cotton soils by changing their properties. Due to rapid growth in construction industry, a lot of waste material is being generated every day, which poses the problem of its disposal. If the waste material can be utilized for soil stabilization, it will mitigate the problems of its disposal. The tests results evaluate that the strength of the Black cotton soils increased by the use of C&D waste material. This study determines various Index and engineering properties of soil and compare for different proportions of soil and C&D Waste. For finding properties of soil and C&D Waste, various test is carried out like sieve analysis, hydrometer test, specific gravity test, Atterberg’s limit test, Standard proctor test and soil Triaxial unconsolidated undrained test. It also takes into account the characteristics alteration due to addition of C&D Waste in active and passive pressure. This study presents the efficacy for use of C&D Waste as a stabilizing material to be mixed with backfill soil in retaining walls. Standard proctor test was conducted at proportions S1W0 (soil = 100%, Waste = 0%), S7W1 (soil = 87.5%, waste = 12.5%), S3W1, S5W3 and S1W1. From these, S5W3 showed optimum results, so this proportion was considered for Soil Triaxial UU-Test. Also, S1W0 was considered too. When 37.5% of soil is replaced by C&D Waste, the Optimum moisture content (OMC) decrease by 11.48%, further, increase C&D Waste in soil OMC remains constant, and maximum dry density (MDD) were observed to be increased by 9.27%, further increased C&D Waste in soil MDD reduces. Carried out strength test, which shows cohesion decreased by 162% and the internal friction angle increased by 49.4% with compare to virgin soil. The study focuses on the potential use of C&D Waste as a stabilizing material in the retaining wall backfill. The active earth pressure decreases, and the passive earth pressure increases in the S5W3 mixture compared to the S1W0 mixture at the same depth.

Keywords: black cotton soil, construction demolition waste, compaction test, strength test

Procedia PDF Downloads 67

Authors: Lars A. L. Giske, Ola J. Mork, Emil Bjoerlykhaug

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The design of fish processing equipment greatly impacts how easy the cleaning process for the equipment is. This is a critical issue in fish processing, as cleaning of fish processing equipment is a task that is both costly and time consuming, in addition to being very important with regards to product quality. Even more, poorly cleaned equipment could in the worst case lead to contaminated product from which consumers could get ill. This paper will elucidate how equipment design changes could improve the work for the cleaners and saving money for the fish processing facilities by looking at a case for product design improvements. The design of fish processing equipment largely determines how easy it is to clean. “Design for cleaning” is the new hype in the industry and equipment where the ease of cleaning is prioritized gets a competitive advantage over equipment in which design for cleaning has not been prioritized. Design for cleaning is an important research area for equipment manufacturers. SeaSide AS is doing continuously improvements in the design of their products in order to gain a competitive advantage. The focus in this paper will be conveyors for internal logistic and a product called the “electro stunner” will be studied with regards to “Design for cleaning”. Often together with SeaSide’s customers, ideas for new products or product improvements are sketched out, 3D-modelled, discussed, revised, built and delivered. Feedback from the customers is taken into consideration, and the product design is revised once again. This loop was repeated multiple times, and led to new product designs. The new designs sometimes also cause the manufacturing processes to change (as in going from bolted to welded connections). Customers report back that the concrete changes applied to products by SeaSide has resulted in overall more easily cleaned equipment. These changes include, but are not limited to; welded connections (opposed to bolted connections), gaps between contact faces, opening up structures to allow cleaning “inside” equipment, and generally avoiding areas in which humidity and water may gather and build up. This is important, as there will always be bacteria in the water which will grow if the area never dries up. The work of creating more cleanable design is still ongoing, and will “never” be finished as new designs and new equipment will have their own challenges.

Keywords: cleaning, design, equipment, fish processing, innovation

Procedia PDF Downloads 221

Authors: Sameh Shahin, Nannang Arrys

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Optimizing pit slope stability and reducing strip ratio of a mining operation are two key tasks in geotechnical engineering. With a growing demand for minerals and an increasing cost associated with extraction, companies are constantly re-evaluating the viability of mineral deposits and challenging their geological understanding. Within Rio Tinto Iron Ore, the Structural Geology (SG) team investigate and collect critical data, such as point based orientations, mapping and geological inferences from adjacent pits to re-model deposits where previous interpretations have failed to account for structurally controlled slope failures. Utilizing innovative data collection methods and data-driven investigation, SG aims to address the root causes of slope instability. Committing to a resource grid drill campaign as the primary source of data collection will often bias data collection to a specific orientation and significantly reduce the capability to identify and qualify complexity. Consequently, these limitations make it difficult to construct a realistic and coherent structural model that identifies adverse structural domains. Without the consideration of complexity and the capability of capturing these structural domains, mining operations run the risk of inadequately designed slopes that may fail and potentially harm people. Regional structural trends have been considered in conjunction with surface and in-pit mapping data to model multi-batter fold structures that were absent from previous iterations of the structural model. The risk is evident in newly identified dip-slope and rock-mass controlled sectors of the geotechnical design rather than a ubiquitous dip-slope sector across the pit. The reward is two-fold: 1) providing sectors of rock-mass controlled design in previously interpreted structurally controlled domains and 2) the opportunity to optimize the slope angle for mineral recovery and reduced strip ratio. Furthermore, a resulting high confidence model with structures and geometries that can account for historic slope instabilities in structurally controlled domains where design assumptions failed.

Keywords: structural geology, geotechnical design, optimization, slope stability, risk mitigation

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Authors: J. Tirano, H. Zea, C. Luhrs

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Photocatalysis has established as viable option in the development of processes for the treatment of pollutants and clean energy production. This option is based on the ability of semiconductors to generate an electron flow by means of the interaction with solar radiation. Owing to its electronic structure, TiO₂ is the most frequently used semiconductors in photocatalysis, although it has a high recombination of photogenerated charges and low solar energy absorption. An alternative to reduce these limitations is the use of nanostructured morphologies which can be produced during the synthesis of TiO₂ nanotubes (TNTs). Therefore, if possible to produce vertically oriented nanostructures it will be possible to generate a greater contact area with electrolyte and better charge transfer. At present, however, the development of these innovative structures still presents an important challenge for the development of competitive photoelectrochemical devices. This research focuses on established correlations between synthesis variables and 1D nanostructure morphology which has a direct effect on the photocatalytic performance. TNTs with controlled morphology were synthesized by two-step potentiostatic anodization of titanium foil. The anodization was carried out at room temperature in an electrolyte composed of ammonium fluoride, deionized water and ethylene glycol. Consequent thermal annealing of as-prepared TNTs was conducted in the air between 450 °C-550 °C. Morphology and crystalline phase of the TNTs were carried out by SEM, EDS and XRD analysis. As results, the synthesis conditions were established to produce nanostructures with specific morphological characteristics. Anatase was the predominant phase of TNTs after thermal treatment. Nanotubes with 10 μm in length, 40 nm in pore diameter and a surface-volume ratio of 50 are important in photoelectrochemical applications based on TiO₂ due to their 1D characteristics, high surface-volume ratio, reduced radial dimensions and high oxide/electrolyte interface. Finally, this knowledge can be used to improve the photocatalytic activity of TNTs by making additional surface modifications with dopants that improve their efficiency.

Keywords: electrochemical anodization, morphology, self-organized nanotubes, TiO₂ nanotubes

Procedia PDF Downloads 137

Authors: Zhongzhong Zeng, Zichen Liang

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In recent years, Beijing courtyards have been facing the problem of renewal and renovation, and the residents are faced with the problems of small house areas, large household sizes, old and dangerous houses, etc. Among the many renovation methods, the authors note two more common practices of using the front porch to expand the floor area and adding a loft. Residents and architects, however, did not give the ventilation performance of the significant interior consideration before beginning the remodeling. The aim of this article is to explore the good or negative impacts of both front porch and loft structures on the manner of interior ventilation in the courtyard. Ventilation, in turn, is crucial to the indoor environmental quality of a home. The major method utilized in this study is the comparative analysis method, in which the authors create four alternative house models with or without a front porch and an attic as two variables and examine internal ventilation using the CFD(Computational Fluid Dynamics) technique. The authors compare the indoor ventilation of four different architectural models with or without front porches and lofts as two variables. The results obtained from the analysis of the sectional airflow and the plane 1.5m height cloud are the existence of the loft, to a certain extent, disrupts the airflow organization of the building and makes the rear wall high windows of the building less effective. Occupying the front porch to become the area of the house has no significant effect on ventilation, but try not to occupy the front porch and add the loft at the same time in the building renovation. The findings of this study led to the following recommendations: strive to preserve the courtyard building's original architectural design and make adjustments to only the inappropriate elements or constructions. The ventilation in the loft portion is inadequate, and the inhabitants typically use the loft as a living area. This may lead to the building relying more on air conditioning in the summer, which would raise energy demand. The front porch serves as a transition place as well as a source of shade, weather protection, and inside ventilation. In conclusion, the examination of interior environments in upcoming studies should concentrate on cross-disciplinary, multi-angle, and multi-level research topics.

Keywords: Beijing courtyard renewal, CFD, indoor environment, ventilation analysis

Procedia PDF Downloads 67

Authors: Helnaz Soltani, J. N. Reddy

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Presence of fluid medium interacting with a structure can lead to failure of the structure. Since developing efficient computational model for fluid-structure interaction (FSI) problems has broader impact to realistic problems encountered in aerospace industry, ship industry, oil and gas industry, and so on, one can find an increasing need to find a method in order to investigate the effect of fluid domain on structural response. A coupled finite element formulation of problems involving FSI issue is an accurate method to predict the response of structures in contact with a fluid medium. This study proposes a finite element approach in order to study the transient response of the structures interacting with a fluid medium. Since beam and plate are considered to be the fundamental elements of almost any structure, the developed method is applied to beams and plates benchmark problems in order to demonstrate its efficiency. The formulation is a combination of the various structure theories and the solid-fluid interface boundary condition, which is used to represent the interaction between the solid and fluid regimes. Here, three different beam theories as well as three different plate theories are considered to model the solid medium, and the Navier-Stokes equation is used as the theoretical equation governed the fluid domain. For each theory, a coupled set of equations is derived where the element matrices of both regimes are calculated by Gaussian quadrature integration. The main feature of the proposed methodology is to model the fluid domain as an added mass; the external distributed force due to the presence of the fluid. We validate the accuracy of such formulation by means of some numerical examples. Since the formulation presented in this study covers several theories in literature, the applicability of our proposed approach is independent of any structure geometry. The effect of varying parameters such as structure thickness ratio, fluid density and immersion depth, are studied using numerical simulations. The results indicate that maximum vertical deflection of the structure is affected considerably in the presence of a fluid medium.

Keywords: beam and plate, finite element analysis, fluid-structure interaction, transient response

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Authors: Pranjali Sharma, Swati Neogi

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Composite pressure vessels are low weight structures mainly used in a variety of applications such as automobiles, aeronautics and chemical engineering. Fiber reinforced polymer (FRP) composite materials offer the simplicity of design and use, high fuel storage capacity, rapid refueling capability, excellent shelf life, minimal infrastructure impact, high safety due to the inherent strength of the pressure vessel, and little to no development risk. Apart from these preliminary merits, the subsidized weight of composite vessels over metallic cylinders act as the biggest asset to the automotive industry, increasing the fuel efficiency. The result is a lightweight, flexible, non-explosive, and non-fragmenting pressure vessel that can be tailor-made to attune with specific applications. The winding pattern of the composite over-wrap is a primary focus while designing a pressure vessel. The critical stresses in the system depend on the thickness, angle and sequence of the composite layers. The composite over-wrap is wound over a plastic liner, whose geometry can be varied for the ease of winding. In the present study, we aim to optimize the FRP vessel geometry that provides an ease in winding and also aids in weight reduction for enhancing the vessel performance. Finite element analysis is used to study the effect of dome geometry, yielding a design with maximum value of burst pressure and least value of vessel weight. The stress and strain analysis of different dome ends along with the cylindrical portion is carried out in ANSYS 19.2. The failure is predicted using different failure theories like Tsai-Wu theory, Tsai-Hill theory and Maximum stress theory. Corresponding to a given winding sequence, the optimum dome geometry is determined for a fixed internal pressure to identify the theoretical value of burst pressure. Finally, this geometry is used to decrease the number of layers to reach the set value of safety in accordance with the available safety standards. This results in decrease in the weight of the composite over-wrap and manufacturing cost of the pressure vessel. An improvement in the overall weight performance of the pressure vessel gives higher fuel efficiency for its use in automobile applications.

Keywords: Compressed Gas Storage, Dome geometry, Theoretical Analysis, Type-4 Composite Pressure Vessel, Improvement in Vessel Weight Performance

Procedia PDF Downloads 128

Authors: Siming Wang, Qing Ni, Yu Wu, Ruihai Xu, Hong Ye

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Porous electric heaters, compared to conventional electric heaters, exhibit excellent heating performance due to their large specific surface area. Porous electric heaters employ porous metallic materials or conductive porous ceramics as the heating element. The former attains a low heating power with a fixed current due to the low electrical resistivity of metal. Although the latter can bypass the inherent challenges of porous metallic materials, the fabrication process of the conductive porous ceramics is complicated and high cost. This work proposed a porous ceramic electric heater with dielectric honeycomb ceramic as a substrate and surface conductive coating as a heating element. The conductive coating was prepared by the sol-gel method using silica sol and methyl trimethoxysilane as raw materials and graphite powder as conductive fillers. The conductive mechanism and degradation reason of the conductive coating was studied by electrical resistivity and thermal stability analysis. The heating performance of the proposed heater was experimentally investigated by heating air and deionized water. The results indicate that the electron transfer is achieved by forming the conductive network through the contact of the graphite flakes. With 30 wt% of graphite, the electrical resistivity of the conductive coating can be as low as 0.88 Ω∙cm. The conductive coating exhibits good electrical stability up to 500°C but degrades beyond 600°C due to the formation of many cracks in the coating caused by the weight loss and thermal expansion. The results also show that the working medium has a great influence on the volume power density of the heater. With air under natural convection as the working medium, the volume power density attains 640.85 kW/m3, which can be increased by 5 times when using deionized water as the working medium. The proposed honeycomb ceramic electric heater has the advantages of the simple fabrication method, low cost, and high volume power density, demonstrating great potential in the fluid heating field.

Keywords: conductive coating, honeycomb ceramic electric heater, high specific surface area, high volume power density

Procedia PDF Downloads 131

Authors: Mona Maria Mombeck

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Social participation in heterogeneous classrooms is one of the main goals in inclusive education. Children with special educational needs (SEN) and children with learning difficulties, or behavioural problems not diagnosed as SEN, are more likely to be excluded by other children than others. It is proven that the presence of dogs, as well as contact with dogs, increases the likelihood of positive social behaviour between humans. Therefore, animal-assisted pedagogy may be presumed to be a constructive way of inclusive teaching and facing the challenges of social inclusion in school classes. This study investigates the presence of a friendly dog in heterogeneous groups of pupils in order to evaluate the influence of dogs on facets of social participation of children in school. 30 German pupils, aged from 10 to 14, in four classes were questioned about their social participation before and after they were educated for a year in school with animal-assisted-pedagogy, using the problem-concerned interview method. In addition, the post-interview includes some general questions about the putative differences or similarities of being educated with and without a dog. The interviews were analysed with the qualitative-content-analysis using QDA software. The results showed that a dog has a positive impact on the atmosphere, student relationships, and well-being in class. Regarding the atmosphere, the pupils mainly argued that the improvement was caused by taking into account the dog’s well-being, respecting the dog-related rules, and by emotional self-regulation. It can be supposed that children regard the rules concerning the dog as more relevant to them than rules, not concerning the dog even if they require the same behaviour and goal. Furthermore, a dog has a positive impact on emotional self-regulation and, therefore, on pupil’s behaviour in class and the atmosphere. In terms of the statements about relationships, the dog’s presence was mainly seen to provide both a unifying aim and a uniting topic to talk about. The improved well-being was described as a feeling of joy and peace of mind. Moreover, the teacher was evaluated as more friendly and trustworthy after animal-assisted teaching. Nevertheless, animal-assisted pedagogy can, rarely, cause problems as well, such as jealousy, distraction, or concerns about the well-being of the dog. The study could prove the relevance of animal-assisted pedagogy for facing the challenges of social participation in inclusive education.

Keywords: animal-assisted-pedagogy, inclusive education, human-animal-interactions, social participation

Procedia PDF Downloads 100

Authors: Theodrose Sisay, Kindie Tesfaye, Mengistu Ketema, Nigussie Dechassa, Mezegebu Getnet

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Agriculture is a sector that is very vulnerable to the effects of climate change and contributes to anthropogenic greenhouse gas (GHG) emissions in the atmosphere. By lowering emissions and adjusting to the change, it can also help to reduce climate change. Utilizing Climate-Smart Agriculture (CSA) technology that can sustainably boost productivity, improve resilience, and lower GHG emissions is crucial. This study sought to identify the CSA technologies used by farmers and assess adoption levels and factors that influence them. In order to gather information from 384 smallholder farmers in the Great Rift Valley (GRV) of Ethiopia, a cross-sectional survey was carried out. Data were analysed using percentage, chi-square test, t-test, and multivariate probit model. Results showed that crop diversification, agroforestry, and integrated soil fertility management were the most widely practiced technologies. The results of the Chi-square and t-tests showed that there are differences and significant and positive connections between adopters and non-adopters based on various attributes. The chi-square and t-test results confirmed that households who were older had higher incomes, greater credit access, knowledge of the climate, better training, better education, larger farms, higher incomes, and more frequent interactions with extension specialists had a positive and significant association with CSA technology adopters. The model result showed that age, sex, and education of the head, farmland size, livestock ownership, income, access to credit, climate information, training, and extension contact influenced the selection of CSA technologies. Therefore, effective action must be taken to remove barriers to the adoption of CSA technologies, and taking these adoption factors into account in policy and practice is anticipated to support smallholder farmers in adapting to climate change while lowering emissions.

Keywords: climate change, climate-smart agriculture, smallholder farmers, multivariate probit model

Procedia PDF Downloads 102

Authors: Yuri Melis, Mattia Resteghini, Emanuela Apicella, Eugenia Dozio, Leonardo Mendolicchio

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Aim: This retrospective study was created to analyze the psychometric, anthropometric and body composition values in patients at the beginning and the discharge of their of hospitalization in the residential care clinic for eating and feeding disorders (EFD’s). Method: The sample was composed by (N=59) patients with mean age N= 33,50, divided in subgroups: Anorexia Nervosa (AN) (N=28), Bulimia Nervosa (BN) (N=13) and Binge Eating Disorders (BED) (N=14) recruited from a residential care clinic for eating and feeding disorders. The psychometrics level was measured with self-report questionnaires: Eating Disorders Inventory-3 (EDI-3) The Body Uneasiness Test (BUT), Minnesota Multiphasic Personality Inventory (MMPI – 2). The anthropometric and nutritional values was collected by Body Impedance Assessment (B.I.A), Body mass index (B.M.I.). Measurements were made at the beginning and at the end of hospitalization, with an average time of recovery of about 8,6 months. Results: The all data analysis showed a statistical significance (p-value >0,05 | power size N=0,950) in variation from T0 (start of recovery) to T1 (end of recovery) in the clinical scales of MMPI-2, AN group (Hypocondria T0 64,14 – T1 56,39) (Depression T0 72,93 – T1 59,50) (Hysteria T0 61,29 – T1 56,17) (Psychopathic deviation T0 64,00 – T1 60,82) (Paranoia T0 63,82 – T1 56,14) (Psychasthenia T0 63,82 – T1 57,86) (Schizophrenia T0 64,68 – T1 60,43) (Obsessive T0 60,36 – T1 55,68); BN group (Hypocondria T0 64,08 – T1 47,54) (Depression T0 67,46 – T1 52,46) (Hysteria T0 60,62 – T1 47,84) (Psychopathic deviation T0 65,69 – T1 58,92) (Paranoia T0 67,46 – T1 55,23) (Psychasthenia T0 60,77 – T1 53,77) (Schizophrenia T0 64,68 – T1 60,43) (Obsessive T0 62,92 – T1 54,08); B.E.D groups (Hypocondria T0 59,43 – T1 53,14) (Depression T0 66,71 – T1 54,57) (Hysteria T0 59,86 – T1 53,82) (Psychopathic deviation T0 67,39 – T1 59,03) (Paranoia T0 58,57 – T1 53,21) (Psychasthenia T0 61,43 – T1 53,00) (Schizophrenia T0 62,29 – T1 56,36) (Obsessive T0 58,57 – T1 48,64). EDI-3 report mean value is higher than clinical cut-off at T0, in T1, there is a significant reduction of the general mean of value. The same result is present in the B.U.T. test in the difference between T0 to T1. B.M.I mean value in AN group is (T0 14,83 – T1 18,41) BN group (T0 20 – T1 21,33) BED group (T0 42,32 – T1 34,97) Phase Angle results: AN group (T0 4,78 – T1 5,64) BN (T0 6 – T1 6,53) BED group (T0 6 – T1 6,72). Discussion and conclusion: The evident presence that on the whole sample, we have an altered serious psychiatric and clinic conditions at the beginning of recovery. The interesting conclusions that we can draw from this analysis are that a multidisciplinary approach that includes the entire care of the subject: from the pharmacological treatment, analytical psychotherapy, Psychomotricity, nutritional rehabilitation, and rehabilitative, educational activities. Thus, this Multidisciplinary treatment allows subjects in our sample to be able to restore psychopathological and metabolic values to below the clinical cut-off.

Keywords: feeding and eating disorders, anorexia nervosa, care clinic treatment, multidisciplinary treatment

Procedia PDF Downloads 111

Authors: Chi-Feng Lai, Wen-Chun Liao Liao

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Many people are bothered by sleep difficulties in Taiwan’s society. However, majority of patients get medical treatments without a comprehensive sleep assessment. It is still a big challenge to formulate a comprehensive assessment of sleep difficulties in clinical settings, even though many assessment tools have existed in literature. This study tries to implement reliable and effective ‘comprehensive sleep assessment scales’ in a medical center and to explore differences in sleep-related factors between clinic clients with or without sleep difficulty complaints. The comprehensive sleep assessment (CSA) scales were composed of 5 dimensions: ‘personal factors’, ‘physiological factors’, ‘psychological factors’, ‘social factors’ and ‘environmental factors, and were first evaluated by expert validity and 20 participants with test-retest reliability. The Content Validity Index (CVI) of the CSA was 0.94 and the alpha of the consistency reliability ranged 0.996-1.000. Clients who visited sleep clinic due to sleep difficulties (n=32, 16 males and 16 females, ages 43.66 ±14.214) and gender-and age- matched healthy subjects without sleep difficulties (n=96, 47 males and 49 females, ages 41.99 ±13.69) were randomly recruited at a ratio of 1:3 (with sleep difficulties vs. without sleep difficulties) to compare their sleep and the CSA factors. Results show that all clinic clients with sleep difficulties did have poor sleep quality (PSQI>5) and mild to moderate daytime sleepiness (ESS >11). Personal factors of long working hours (χ2= 10.315, p=0.001), shift workers (χ2= 8.964, p=0.003), night shift (χ2=9.395, p=0.004) and perceived stress (χ2=9.503, p=0.002) were disruptors of sleep difficulties. Physiological factors from physical examination including breathing by mouth, low soft palate, high narrow palate, Edward Angle, tongue hypertrophy, and occlusion of the worn surface were observed in clinic clients. Psychological factors including higher perceived stress (χ2=32.542, p=0.000), anxiety and depression (χ2=32.868, p=0.000); social factors including lack of leisure activities (χ2=39.857, p=0.000), more drinking habits (χ2=1.798, p=0.018), irregular amount and frequency in meals (χ2=5.086, p=0.024), excessive dinner (χ2=21.511, p=0.000), being incapable of getting up on time due to previous poor night sleep (χ2=4.444, p=0.035); and environmental factors including lights (χ2=7.683, p=0.006), noise (χ2=5.086, p=0.024), low or high bedroom temperature (χ2=4.595, p=0.032) were existed in clients. In conclusion, the CSA scales can work as valid and reliable instruments for evaluating sleep-related factors. Findings of this study provide important reference for assessing clinic clients with sleep difficulties.

Keywords: comprehensive sleep assessment, sleep-related factors, sleep difficulties

Procedia PDF Downloads 259

Authors: Luna Degife, Desalegn Belay, Yoseph Worku, Tigist Tesfaye, Assefa Tufa, Abyot Bekele, Zegeye Hailemariam, Abay Hagos

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Half of the world’s population is at risk of Dengue Fever (DF), a highly under-recognized and underreported mosquito-borne viral disease with high prevalence in the tropical and subtropical regions. Globally, an estimated 50 to 200 million cases and 20, 000 DF deaths occur annually as per the world health organization report. In Ethiopia, the first outbreak occurred in 2013 in Diredawa administration city. Afterward, three outbreaks have been reported from the eastern part of the country. We received a report of the fifth DF outbreak for Ethiopia and the second for Diredawa city on October 4, 2015. We conducted the investigation to confirm the outbreak, identify the risk factors for the repeatedly occurrence of the disease and implement control measures. We conducted un- matched case-control study and defined a suspected DF case as any person with fever of 2-7 days and 2 or more of the following: a headache, arthralgia, myalgia, rash, or bleeding from any part of the body. Controls were residents of Diredawa city without DF symptoms. We interviewed 70 Cases and 140 controls from all health facilities in Diredawa city from October 7 to 15; 2015. Epi Info version 7.1.5.0 was used to analyze the data and multivariable logistic regression was conducted to assess risk factors for DF. Sixty-nine blood samples were collected for Laboratory confirmation.The mean age for cases was 23.7±9.5 standard deviation (SD) and for controls 31.2±13 SD. Close contact with DF patient (Adjusted odds ratio (AOR)=5.36, 95% confidence interval(CI): 2.75-10.44), nonuse of long-lasting insecticidal nets (AOR=2.74, 95% CI: 1.06-7.08) and availability of stagnant water in the village (AOR=3.61, 95% CI:1.31-9.93) were independent risk factors associated with higher rates of the disease. Forty-two samples were tested positive. Endemicity of DF is becoming a concern for Diredawa city after the first outbreak. Therefore, effective vector control activities need to be part of long-term preventive measures.

Keywords: dengue fever, Diredawa, outbreak, risk factors, second

Procedia PDF Downloads 252

Authors: Mostafa Zandi, Ramin Mansouri

Abstract:

Spillways are one of the most important hydraulic structures of dams that provide the stability of the dam and downstream areas at the time of flood. Morning-Glory spillway is one of the common spillways for discharging the overflow water behind dams, these kinds of spillways are constructed in dams with small reservoirs. In this research, the hydraulic flow characteristics of a morning-glory spillways are investigated with CFD model. Two dimensional unsteady RANS equations were solved numerically using Finite Volume Method. The PISO scheme was applied for the velocity-pressure coupling. The mostly used two-equation turbulence models, k- and k-, were chosen to model Reynolds shear stress term. The power law scheme was used for discretization of momentum, k , and  equations. The VOF method (geometrically reconstruction algorithm) was adopted for interface simulation. The results show that the fine computational grid, the input speed condition for the flow input boundary, and the output pressure for the boundaries that are in contact with the air provide the best possible results. Also, the standard wall function is chosen for the effect of the wall function, and the turbulent model k -ε (Standard) has the most consistent results with experimental results. When the jet is getting closer to end of basin, the computational results increase with the numerical results of their differences. The lower profile of the water jet has less sensitivity to the hydraulic jet profile than the hydraulic jet profile. In the pressure test, it was also found that the results show that the numerical values of the pressure in the lower landing number differ greatly in experimental results. The characteristics of the complex flows over a Morning-Glory spillway were studied numerically using a RANS solver. Grid study showed that numerical results of a 57512-node grid had the best agreement with the experimental values. The desired downstream channel length was preferred to be 1.5 meter, and the standard k-ε turbulence model produced the best results in Morning-Glory spillway. The numerical free-surface profiles followed the theoretical equations very well.

Keywords: morning-glory spillway, CFD model, hydraulic characteristics, wall function

Procedia PDF Downloads 58