Search results for: Modified Taylor-Couette Flow

Authors: Afnan Ahmad, Shahid Ali, Mujahid Khan

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This research presents the parametric study of an existing earth fill dam located at Latamber, Karak city, Pakistan. The study consists of carrying out seepage analysis, slope stability analysis, and Earthquake analysis of the dam for the existing dam geometry and do the same for modified geometry. Dams are massive as well as expensive hydraulic structure, therefore it needs proper attention. Additionally, this dam falls under zone 2B region of Pakistan, which is an earthquake-prone area and where ground accelerations range from 0.16g to 0.24g peak. So it should be deal with great care, as the failure of any dam can cause irreparable losses. Similarly, seepage as well as slope failure can also cause damages which can lead to failure of the dam. Therefore, keeping in view of the importance of dam construction and associated costs, our main focus is to carry out parametric study of newly constructed dam. GeoStudio software is used for this analysis in the study in which Seep/W is used for seepage analysis, Slope/w is used for Slope stability analysis and Quake/w is used for earthquake analysis. Based on the geometrical, hydrological and geotechnical data, Seepage and slope stability analysis of different proposed geometries of the dam are carried out along with the Seismic analysis. A rigorous analysis was carried out in 2-D limit equilibrium using finite element analysis. The seismic study began with the static analysis, continuing by the dynamic response analysis. The seismic analyses permitted evaluation of the overall patterns of the Latamber dam behavior in terms of displacements, stress, strain, and acceleration fields. Similarly, the seepage analysis allows evaluation of seepage through the foundation and embankment of the dam, while slope stability analysis estimates the factor of safety of the upstream and downstream of the dam. The results of the analysis demonstrate that among multiple geometries, Latamber dam is secure against seepage piping failure and slope stability (upstream and downstream) failure. Moreover, the dam is safe against any dynamic loading and no liquefaction has been observed while changing its geometry in permissible limits.

Keywords: earth-fill dam, finite element, liquefaction, seepage analysis

Procedia PDF Downloads 169

Authors: Kamellia Reshadi, Pranav Ragji, Theodoros Soldatos

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Recent advancements in cloud computing and storage, along with rapid progress in artificial intelligence (AI), have transformed approaches to developing efficient, scalable applications. However, integrating AI with cloud computing poses challenges as these fields are often disjointed, and many advancements remain difficult to access, obscured in complex documentation or scattered across research reports. For this reason, we share experiences from prototype projects combining these technologies. Specifically, we focus on Google Cloud Platform (GCP) functionalities and describe vision and speech activities applied to labeling, subtitling, and urban traffic flow tasks. We describe challenges, pricing, architecture, and other key features, considering the goal of real-time performance. We hope our demonstrations provide not only essential guidelines for using these functionalities but also enable more similar approaches.

Keywords: artificial intelligence, cloud computing, real-time applications, case studies, knowledge management, research and development, text labeling, video annotation, urban traffic analysis, public safety, prototyping, Google Cloud Platform

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Authors: M. Mazraehli, F. Mehrabani, S. Zare

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In general, mechanical and hydraulic processes are not independent of each other in jointed rock masses. Therefore, the study on hydro-mechanical coupling of geomaterials should be a center of attention in rock mechanics. Rocks in their nature contain discontinuities whose presence extremely influences mechanical and hydraulic characteristics of the medium. Assuming this effect, experimental investigations on intact rock cannot help to identify jointed rock mass behavior. Hence, numerical methods are being used for this purpose. In this paper, water inflow into a tunnel under significant water table has been estimated using hydro-mechanical discrete element method (HM-DEM). Besides, effects of geomechanical and geometrical parameters including constitutive model, friction angle, joint spacing, dip of joint sets, and stress factor on the estimated inflow rate have been studied. Results demonstrate that inflow rates are not identical for different constitutive models. Also, inflow rate reduces with increased spacing and stress factor.

Keywords: distinct element method, fluid flow, hydro-mechanical coupling, jointed rock mass, underground excavations

Procedia PDF Downloads 169

Authors: E. Behmanesh, J. Pannek

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Logistics network design is known as one of the strategic decision problems. As these kinds of problems belong to the category of NP-hard problems, traditional ways are failed to find an optimal solution in short time. In this study, we attempt to involve reverse flow through an integrated design of forward/reverse supply chain network that formulated into a mixed integer linear programming. This Integrated, multi-stages model is enriched by three different delivery path which makes the problem more complex. To tackle with such an NP-hard problem a revised random path direct encoding method based memetic algorithm is considered as the solution methodology. Each algorithm has some parameters that need to be investigate to reveal the best performance. In this regard, Taguchi method is adapted to identify the optimum operating condition of the proposed memetic algorithm to improve the results. In this study, four factors namely, population size, crossover rate, local search iteration and a number of iteration are considered. Analyzing the parameters and improvement in results are the outlook of this research.

Keywords: integrated logistics network, flexible path, memetic algorithm, Taguchi method

Procedia PDF Downloads 194

Authors: Zhenghua Dai, Jianliang Xu, Fuchen Wang

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Non-catalyst partial oxidation technology has been widely used to produce syngas by reforming of hydrocarbon, including gas (natural gas, shale gas, refinery gas, coalbed gas, coke oven gas, pyrolysis gas, etc.) and liquid (residual oil, asphalt, deoiled asphalt, biomass oil, etc.). For natural gas non-catalyst partial oxidation, the H₂/CO(v/v) of syngas is about 1.8, which is agreed well with the request of FT synthesis. But for other process, such as carbonylation and glycol, the H₂/CO(v/v) should be close to 1 and 2 respectively. So the syngas composition of non-catalyst partial oxidation should be adjusted to satisfy the request of different chemical synthesis. That means a multi-reforming method by CO₂ and H₂O addition. The natural gas non-catalytic partial oxidation hot model was established. The effects of O₂/CH4 ratio, steam, and CO₂ on the syngas composition were studied. The results of the experiment indicate that the addition of CO₂ and steam into the reformer can be applied to change the syngas H₂/CO ratio. The reactor network model (RN model) was established according to the flow partition of industrial reformer and GRI-Mech 3.0. The RN model results agree well with the industrial data. The effects of steam, CO₂ on the syngas compositions were studied with the RN model.

Keywords: non-catalyst partial oxidation, natural gas, H₂/CO, CO₂ and H₂O addition, multi-reforming method

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Authors: Pradakshina Sharma, Jagriti Narang

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Due to the critical significance in the early identification of infectious diseases, electrochemical sensors have garnered considerable interest. Here, we develop a detection platform for the chikungunya virus by rationally implementing the extremely high charge-transfer efficiency of a ternary nanocomposite of graphene oxide, silver, and gold (G/Ag/Au) (CHIKV). Because paper is an inexpensive substrate and can be produced in large quantities, the use of electrochemical paper analytical device (EPAD) origami further enhances the sensor's appealing qualities. A cost-effective platform for point-of-care diagnostics is provided by paper-based testing. These types of sensors are referred to as eco-designed analytical tools due to their efficient production, usage of the eco-friendly substrate, and potential to reduce waste management after measuring by incinerating the sensor. In this research, the paper's foldability property has been used to develop and create 3D multifaceted biosensors that can specifically detect the CHIKVX-ray diffraction, scanning electron microscopy, UV-vis spectroscopy, and transmission electron microscopy (TEM) were used to characterize the produced nanoparticles. In this work, aptamers are used since they are thought to be a unique and sensitive tool for use in rapid diagnostic methods. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV), which were both validated with a potentiostat, were used to measure the analytical response of the biosensor. The target CHIKV antigen was hybridized with using the aptamer-modified electrode as a signal modulation platform, and its presence was determined by a decline in the current produced by its interaction with an anionic mediator, Methylene Blue (MB). Additionally, a detection limit of 1ng/ml and a broad linear range of 1ng/ml-10µg/ml for the CHIKV antigen were reported.

Keywords: biosensors, ePAD, arboviral infections, point of care

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Authors: Chakshu Baweja, Ishaan Prakash, Deepak Giri, Prithwish Mukherjee, Herambraj Ashok Nalawade

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The need to prevent and control rampant and indiscriminate usage of energy in present-day realm on earth has motivated active research efforts aimed at understanding of controlling mechanisms leading to sustained energy. Although much has been done but complexity of the problem has prevented a complete understanding due to nonlinear interaction between flow, heat and mass transfer in terrestrial environment. Therefore, there is need for a systematic study to clearly understand mechanisms controlling energy-spreading phenomena to increase a system’s efficiency. The present work addresses the issue of sustaining energy and proposes a devoted technique of optimizing energy in the automotive domain. The proposed method focus on utilization of the mechanical and thermal energy of an automobile IC engine by converting and storing energy due to motion of a piston in form of electrical energy. The suggested technique utilizes piston motion of the engine to generate high potential difference capable of working as a secondary power source. This is achieved by the use of a gear mechanism and a flywheel.

Keywords: internal combustion engine, energy, electromagnetic induction, efficiency, gear ratio, hybrid vehicle, engine shaft

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Authors: Karla E. Sanchez-Cazares, Kim H. Parker, Jennifer H. Tweedy

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The purpose of this work is to develop a simple compartmental model of cerebral fluid balance including blood and cerebrospinal-fluid (CSF). At the first level the cerebral arteries and veins are modelled as bifurcating trees with constant scaling factors between generations which are connected through a homogeneous microcirculation. The arteries and veins are assumed to be non-rigid and the cross-sectional area, resistance and mean pressure in each generation are determined as a function of blood volume flow rate. From the mean pressure and further assumptions about the variation of wall permeability, the transmural fluid flux can be calculated. The results suggest the next level of modelling where the cerebral vasculature is divided into three compartments; the large arteries, the small arteries, the capillaries and the veins with effective compliances and permeabilities derived from the detailed vascular model. These vascular compartments are then linked to other compartments describing the different CSF spaces, the cerebral ventricles and the subarachnoid space. This compartmental model is used to calculate the distribution of fluid in the cranium. Known volumes and flows for normal conditions are used to determine reasonable parameters for the model, which can then be used to help understand pathological behaviour and suggest clinical interventions.

Keywords: cerebrovascular, compartmental model, CSF model, vascular network

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Authors: Tahani Amutairi, Paul May, Neil Allan

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Many properties of semiconductor materials (mechanical, electronic, magnetic, and optical) can be significantly modified by introducing a point defect. Diamond offers extraordinary properties as a semiconductor, and doping seems to be a viable method of solving the problem associated with the fabrication of diamond-based electronic devices in order to exploit those properties. The dopants are believed to play a significant role in reducing the energy barrier to conduction and controlling the mobility of the carriers and the resistivity of the film. Although it has been proven that the n-type diamond semiconductor can be obtained with phosphorus doping, the resulting ionisation energy and mobility are still inadequate for practical application. Theoretical studies have revealed that this is partly because the effects of the many phosphorus atoms incorporated in the diamond lattice are compensated by acceptor states. Using spin-polarised hybrid density functional theory and a supercell approach, we explored the effects of bonding one N atom to a P in adjacent substitutional sites in diamond. A range of hybrid functional, including HSE06, B3LYP, PBE0, PBEsol0, and PBE0-13, were used to calculate the formation, binding, and ionisation energies, in order to explore the solubility and stability of the point defect. The equilibrium geometry and the magnetic and electronic structures were analysed and presented in detail. The defect introduces a unique reconstruction in a diamond where one of the C atoms coordinated with the N atom involved in the elongated C-N bond and creates a new bond with the P atom. The simulated infrared spectra of phosphorus-nitrogen defects were investigated with different supercell sizes and found to contain two sharp peaks at the edges of the spectrum, one at a high frequency 1,379 cm⁻¹ and the second appearing at the end range, 234 cm⁻¹, as obtained with the largest supercell (216).

Keywords: DFT, HSE06, B3LYP, PBE0, PBEsol0, PBE0-13

Procedia PDF Downloads 90

Authors: Mohamed S. Selim, Nesreen A. Fatthallah, Shimaa A. Higazy, Zhifeng Hao, Ping Jing Mo

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As marine fouling-release (FR) surfaces, two new superhydrophobic nanocomposite series of polydimethylsiloxane (PDMS) loaded with reduced graphene oxide (RGO) and graphene oxide/boehmite nanorods (GO-γ-AlOOH) nanofillers were created. The self-cleaning and antifouling capabilities were modified by controlling the nanofillers' shapes and distribution in the silicone matrix. With an average diameter of 10-20 nm and a length of 200 nm, γ-AlOOH nanorods showed a single crystallinity. RGO was made using a hydrothermal process, whereas GO-γ-AlOOH nanocomposites were made using a chemical deposition method for use as fouling-release coating materials. These nanofillers were disseminated in the silicone matrix using the solution casting method to explore the synergetic effects of graphene-based materials on the surface, mechanical, and FR characteristics. Water contact angle (WCA), scanning electron, and atomic force microscopes were used to investigate the surface's hydrophobicity and antifouling capabilities (SEM and AFM). The roughness, superhydrophobicity, and surface mechanical characteristics of coatings all increased the homogeneity of the nanocomposite dispersion. To examine the antifouling effects of the coating systems, laboratory tests were conducted for 30 days using specified bacteria.PDMS/GO-γ-AlOOH nanorod composite demonstrated superior antibacterial efficacy against several bacterial strains than PDMS/RGO nanocomposite. The high surface area and stabilizing effects of the GO-γ-AlOOH hybrid nanofillers are to blame for this. The biodegradability percentage of the PDMS/GO-γ-AlOOH nanorod composite (3 wt.%) was the lowest (1.6%), while the microbial endurability percentages for gram-positive, gram-negative, and fungi were 86.42%, 97.94%, and 85.97%, respectively. The homogeneity of the GO-γ-AlOOH (3 wt.%) dispersion, which had a WCA of 151° and a rough surface, was the most profound superhydrophobic antifouling nanostructured coating.

Keywords: superhydrophobic nanocomposite, fouling release, nanofillers, surface coating

Procedia PDF Downloads 239

Authors: H. Fuad Usman, M. Rafay Khan Sial, Shahzaib Hamid

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The trend of renewable energy resources has been amplified due to global warming and other environmental related complications in the 21st century. Recent research has very much emphasized on the generation of electrical power through renewable resources like solar, wind, hydro, geothermal, etc. The use of the photovoltaic cell has become very public as it is very useful for the domestic and commercial purpose overall the world. Although a single cell gives the low voltage output but connecting a number of cells in a series formed a complete module of the photovoltaic cells, it is becoming a financial investment as the use of it fetching popular. This also reduced the prices of the photovoltaic cell which gives the customers a confident of using this source for their electrical use. Photovoltaic cell gives the MPPT at single specific point of operation at a given temperature and level of solar intensity received at a given surface whereas the focal point changes over a large range depending upon the manufacturing factor, temperature conditions, intensity for insolation, instantaneous conditions for shading and aging factor for the photovoltaic cells. Two improved algorithms have been proposed in this article for the MPPT. The widely used algorithms are the ‘Incremental Conductance’ and ‘Perturb and Observe’ algorithms. To extract the maximum power from the source to the load, the duty cycle of the convertor will be effectively controlled. After assessing the previous techniques, this paper presents the improved and reformed idea of harvesting maximum power point from the photovoltaic cells. A thoroughly go through of the previous ideas has been observed before constructing the improvement in the traditional technique of MPP. Each technique has its own importance and boundaries at various weather conditions. An improved technique of implementing the use of both ‘Perturb and Observe’ and ‘Incremental Conductance’ is introduced.

Keywords: duty cycle, MPPT (Maximum Power Point Tracking), perturb and observe (P&O), photovoltaic module

Procedia PDF Downloads 181

Authors: Md. Moinul Islam, N. M. Golam Zakaria

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Seakeeping analysis of catamaran vessels in the earlier stages of design has become an important issue as it dictates the seakeeping characteristics, and it ensures safe navigation during the voyage. In the present paper, a 3D numerical method for the seakeeping prediction of catamaran vessel is presented using the 3D Green Function method. Both steady and unsteady potential flow problem is dealt with here. Using 3D linearized potential theory, the dynamic wave loads and the subsequent response of the vessel is computed. For validation of the numerical procedure catamaran vessel composed of twin, Wigley form demi-hull is used. The results of the present calculation are compared with the available experimental data and also with other calculations. The numerical procedure is also carried out for NPL-based round bilge catamaran, and hydrodynamic coefficients along with heave and pitch motion responses are presented for various Froude number. The results obtained by the present numerical method are found to be in fairly good agreement with the available data. This can be used as a design tool for predicting the seakeeping behavior of catamaran ships in waves.

Keywords: catamaran, hydrodynamic coefficients , motion response, 3D green function

Procedia PDF Downloads 226

Authors: M. Arabghahestani, A. Darwish Ahmad, N. K. Akafuah

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In this work, small-scale experiments of fire whirl were conducted to study the spinning fire phenomenon and to gain comprehensive understandings of fire tornadoes and the factors that affect their behavior. High speed imaging was used to track the flames at both temporal and spatial scales. This allowed us to better understand the role of the near-ground height in creating a boundary layer flow profile that, in turn contributes to formation of vortices around the fire, and consequent fire whirls. Based on the results obtained from these observations, we were able to spot the differences in the fuel burning rate of the fire itself as a function of a newly defined specific non-dimensional near-ground height. Based on our observations, there is a cutoff non-dimensional height, beyond which a normal fire can be turned into a fire whirl. Additionally, the results showed that the fire burning rate decreases by moving the fire to a height higher than the ground level. These effects were justified by the interactions between vortices formed by, the back pressure and the boundary layer velocity profile, and the vortices generated by the fire itself.

Keywords: boundary layer profile, fire whirls, near-ground height, vortex interactions

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Authors: Vimal Kumar Chouksey, S. P. Sharma

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This paper deals with theoretical analysis of performance of solar air collector having its duct packed with blackened wire screen matrices. The heat transfer equations for two-dimensional fully developed fluid flows under quasi-steady-state conditions have been developed in order to analyze the effect of bed depth on performance. A computer programme is developed in C++ language to estimate the temperature rise of entering air for evaluation of performance by solving the governing equations numerically using relevant correlations for heat transfer coefficient for packed bed systems. Results of air temperature rise and thermal efficiency obtained from the analysis have been compared with available experimental results and results have been found fairly in closed agreement. It has been found that there is considerable enhancement in performance with packed bed collector upto a certain total bed depth. Effect of total bed depth on efficiency show that there is an upper limiting value of total bed depth beyond which the thermal efficiency begins to fall again and this type of characteristics behavior is observed at all mass flow rate.

Keywords: plane collector, solar air heater, solar energy, wire screen packed bed

Procedia PDF Downloads 243

Authors: Jihoon Lim, Patrick Kirchen, Ryozo Nagamune

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This paper proposes a linear parameter-varying (LPV) controller capable of reducing nitrogen oxide (NOx) emissions with low ammonia (NH3) slip downstream of selective catalytic reduction (SCR) systems. SCR systems are widely adopted in diesel engines due to high NOx conversion efficiency. However, the nonlinearity of the SCR system and sensor uncertainty result in a challenging control problem. In order to overcome the control challenges, an LPV controller is proposed based on gain-scheduling parameters, that is, exhaust gas temperature and exhaust gas flow rate. Based on experimentally obtained data under the non-road transient driving cycle (NRTC), the simulations firstly show that the proposed controller yields high NOx conversion efficiency with a desired low NH3 slip. The performance of the proposed LPV controller is then compared with other controllers, including a gain-scheduling PID controller and a sliding mode controller. Additionally, the robustness is also demonstrated using the uncertainties ranging from 10 to 30%. The results show that the proposed controller is robustly stable under uncertainties.

Keywords: diesel engine, gain-scheduling control, linear parameter-varying, selective catalytic reduction

Procedia PDF Downloads 149

Authors: Chongsutthamani Sitthiwet, Praphatsorn Plerdsranoy, Palmarin Dansirima, Priew Eiamlamai, Oliver Utke, Rapee Utke

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Hydrogen storage tank containing compacted LiNH2-LiH is developed by doping with TiF₄ and multi-walled nanotubes (MWCNTs) to study kinetic properties. Transition metal-based catalyst (TiF₄) provides the catalytic effect on hydrogen dissociation/recombination, while MWCNTs benefit thermal conductivity and hydrogen permeability during de/rehydrogenation process. The Enhancement of dehydrogenation kinetics is observed from the single-step reaction at a narrower and lower temperature range of 150-350 ºC (100 ºC lower than the compacted LiNH₂-LiH without additives) as well as long plateau temperature and constant hydrogen flow rate (50 SCCM) up to 30 min during desorption. Besides, Hydrogen contents de/absorbed during 5-6 cycles increase from 1.90-2.40 to 3.10-4.70 wt. % H₂ (from 29 to up to 80 % of theoretical capacity). In the process, Li₅TiN₃ is detected upon cycling probably absorbs NH₃ to form Li₅TiN₃(NH₃)x, which is favoring hydrogen sorption properties of the LiNH₂-LiH system. Importantly, the homogeneous reaction mechanisms and performances are found at all positions inside the tank of compacted LiNH₂-LiH doped with TiF₄ and MWCNTs.

Keywords: carbon, hydride, kinetics, dehydrogenation

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Authors: Y. Jeon, A. Bissessur, J. Lin, P. Ndungu

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Most transformers employ the usage of cellulose paper, which has been chemically modified through the Kraft process that acts as an effective insulator. Cellulose ageing and oil degradation are directly linked to fouling of the transformer and accumulation of large quantities of waste insulating paper. In addition to technical difficulties, this proves costly for power utilities to deal with. Currently there are no cost effective method for the rejuvenation of cellulose paper that has been documented nor proposed, since renewal of used insulating paper is implemented as the best option. This study proposes and contrasts different rejuvenation methods of accelerated aged cellulose insulating paper by chemical and bio-bleaching processes. Of the three bleaching methods investigated, two are, conventional chlorine-based sodium hypochlorite (m/v), and chlorine-free hydrogen peroxide (v/v), whilst the third is a bio-bleaching technique that uses a bacterium isolate, Acinetobacter strain V2. Through chemical bleaching, varying the strengths of the bleaching reagents at 0.3 %, 0.6 %, 0.9 %, 1.2 %, 1.5 % and 1.8 % over 4 hrs. were analyzed. Bio-bleaching implemented a bacterium isolate, Acinetobacter strain V2, to bleach the aged Kraft paper over 4 hrs. The determination of the amount of alpha cellulose, degree of polymerization and viscosity carried out on Kraft-cellulose insulating paper before and after bleaching. Overall the investigated techniques of chemical and bio-bleaching were successful and effective in treating degraded and accelerated aged Kraft-cellulose insulating paper, however, to varying extents. Optimum conditions for chemical bleaching were attained at bleaching strengths of 1.2 % (m/v) NaOCl and 1.5 % (v/v) H2O2 yielding alpha cellulose contents of 82.4 % and 80.7 % and degree of polymerizations of 613 and 616 respectively. Bio-bleaching using Acinetobacter strain V2 proved to be the superior technique with alpha cellulose levels of 89.0 % and a degree of polymerization of 620. Chemical bleaching techniques require careful and controlled clean-up treatments as it is chlorine and hydrogen peroxide based while bio-bleaching is an extremely eco-friendly technique.

Keywords: alpha cellulose, bio-bleaching, degree of polymerization, Kraft-cellulose insulating paper, transformer, viscosity

Procedia PDF Downloads 275

Authors: I. Behroyan, P. Ganesan, S. He, S. Sivasankaran

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This study compares the predictions of five types of Computational Fluid Dynamics (CFD) models, including two single-phase models (i.e. Newtonian and non-Newtonian) and three two-phase models (Eulerian-Eulerian, mixture and Eulerian-Lagrangian), to investigate turbulent forced convection of Cu-water nanofluid in a tube with a constant heat flux on the tube wall. The Reynolds (Re) number of the flow is between 10,000 and 25,000, while the volume fraction of Cu particles used is in the range of 0 to 2%. The commercial CFD package of ANSYS-Fluent is used. The results from the CFD models are compared with results from experimental investigations from literature. According to the results of this study, non-Newtonian single-phase model, in general, does not show a good agreement with Xuan and Li correlation in prediction of Nu number. Eulerian-Eulerian model gives inaccurate results expect for φ=0.5%. Mixture model gives a maximum error of 15%. Newtonian single-phase model and Eulerian-Lagrangian model, in overall, are the recommended models. This work can be used as a reference for selecting an appreciate model for future investigation. The study also gives a proper insight about the important factors such as Brownian motion, fluid behavior parameters and effective nanoparticle conductivity which should be considered or changed by the each model.

Keywords: heat transfer, nanofluid, single-phase models, two-phase models

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Authors: Oluwatobi Emmanuel Olaniyi, Babafemi George Ogunjemite

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The high rate of infrastructural development in Ikogosi warm spring towards harnessing her great ecotourism potentials calls for a serious concern, as more forest areas are been opened up for public access and the landscape is modified. On this note, we investigated the implication of ecotourism development on the floristic composition and forest structure in Ikogosi. The study aimed at identifying the past and present status of infrastructural development, assessing and comparing the floristic composition and structure of the built- up/ recreational areas and undisturbed forested areas, to infer on the impact of ecotourism development on the study site. We conducted stakeholder interview and field observation to identify the past and present status of infrastructural development respectively. A total of ten quadrants were employed in the vegetation assessment to characterize the woody tree species composition, diameter at breast height and height, to obtain mean indices characterizing each part of the site. These indices were compared using T – test analysis. A total of 49 different woody tree species distributed in 21 families were identified in the built-in/ recreational areas while 67 different woody tree species belonging to 25 families were recorded in the undeveloped forested areas. Although, the latter has a higher mean diameter at breast height of woody trees, it was not significantly different from the former (T-test = -0.74, p = 0.46). On the contrary, the built-up area had a higher mean trees height than the undeveloped areas, but the difference was not statistically significant (T-test= 1.04, p = 0.30). Despite these, the slight reduction in richness and diversity of the woody tree species in the built- up/ recreational areas implies mitigating the negative effects of infrastructural development on the warm spring's vegetation.

Keywords: ecosystem services, forest structure, vegetation assessment, warm-spring

Procedia PDF Downloads 515

Authors: Kasra Afsahi, Maryam Soheilifar, S. Hossein Hosseini, Omid Seyed Esmaeili, Rouzbeh Kezemi, Noushin Mehrbod, Nazanin Vahed, Tahereh Hajiahmad, Noureddin Nakhostin Ansari

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Background: Stroke is a disabling neurological disease. Rehabilitative therapies are important treatment methods. This clinical trial was done to compare the effects of VR beside conventional rehabilitation versus conventional rehabilitation alone on spasticity and motor function in stroke patients. Materials and Methods: In this open-label randomized controlled clinical trial, 40 consecutive patients with stable first-ever ischemic stroke in the past three to 12 months that were referred to a rehabilitation clinic in Tehran, Iran, in 2020 were enrolled. After signing the informed written consent form, subjects were randomly assigned by block randomization of five in each block as cases with 1:1 into two groups of 20 cases; conventional plus VR therapy group: 45-minute conventional therapy session plus 15-minute VR therapy, and conventional group: 60-minute conventional therapy session. VR rehabilitation is designed and developed with different stages. Outcomes were modified Ashworth scale, recovery stage score for motor function, range of motion (ROM) of shoulder abduction/wrist extension, and patients’ satisfaction rate. Data were compared after study termination. Results: The satisfaction rate among the patients was significantly better in the combination group (P=0.003). Only wrist extension was varied between groups and was better in the combination group. The variables generally had a statistically significant difference (P < 0.05). Conclusion: Virtual reality plus conventional rehabilitation therapy is superior versus conventional rehabilitation alone on the wrist and elbow spasticity and motor function in patients with stroke.

Keywords: stroke, virtual therapy, rehabilitation, treatment

Procedia PDF Downloads 239

Authors: A. Hadjadj, S. Maamir

Abstract:

Since the advent of the law 86/14 concerning the
exploitation of the national territory by foreign companies in
partnership with the Algerian oil and gas company, the problem of
hydrocarbons metering in the sharing production come out.
More generally, good management counting hydrocarbons can
provide data on the production wells, the field and the reservoir for
medium and long term planning, particularly in the context of the
management and field development.
In this work, we are interested in the transactional metering which
is a very delicate and crucial period in the current context of the new
hydrocarbon’s law characterized by assets system between the
various activities of Sonatrach and its foreign partners.
After a state of the art on hydrocarbons metering devices in
Algeria and elsewhere, we will decline the advantages and
disadvantages of each system, and then we describe the problem to
try to reach an optimal solution.

Keywords: transactional metering, flowmeter orifice, heat flow, Sonatrach

Procedia PDF Downloads 367

Authors: Nour Eldin Afyouni, Hassan Assoum, Kamel Abed-Meraim, Anas Sakout

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The acoustic of an impinging jet holds significant importance in the engineering field. In HVAC systems, the jet impingement, in some cases, generates noise that destroys acoustic comfort. This paper presents an experimental study of a rectangular air jet impinging on a slotted plate to investigate the correlation between sound emission and turbulence dynamics. The experiment was conducted with an impact ratio L/H = 4 and a Reynolds number Re = 4700. The survey shows that coherent structures within the impinging jet are responsible for self-sustaining tone production. To achieve this, a specific experimental setup consisting of two simultaneous Stereoscopic Particle Image Velocimetry (S-PIV) measurements was developed to track vortical structures both before and after the plate, in addition to acoustic measurements. The results reveal a significant correlation between acoustic waves and the passage of coherent structures. Variations in the arrangement of vortical structures between the upstream and downstream sides of the plate were observed. This analysis of flow dynamics can enhance our understanding of slot noise.

Keywords: impinging jet, coherent structures, SPIV, aeroacoustics

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Authors: Lubna Khondker

Abstract:

Background: Melasma is a common pigmentary dermatosis, manifested by hyperpigmented macules or patches on the face, commonly occurring in females due to an acquired disorder in the melanogenesis process. Although several treatments are currently used, it remains a great challenge due to recurrence and refractory nature. It was recently reported that tranexamic acid (TA-plasmin inhibitor) is an effective treatment for melasma. Objective: This study aims to compare the efficacy and side effects of intralesional injection of Tranexamic acid with oral Tranexamic acid in the treatment of melasma. Methods: A clinical trial was done in the Department of Dermatology and Venereology, Bangabandhu Sheikh Mujib Medical University, for a period of 4 years. A total of 100 patients with melasma who did not respond to topical therapy were included in the study as group A and group B. Group A Patients were administered intralesional injection (10 mg/ml) of Tranexamic acid( TA) weekly for 6 weeks, and group B patients were treated with oral tranexamic acid 250 mg 12 hourly for 12 weeks after taking informed consent. The severity and extent of pigmentation were assessed by the modified melasma area severity index (MASI). The response to treatment was assessed by MASI at 4 weeks, 8 weeks, and 12 weeks after stopping treatment. Results: The study showed the MASI scores at the baseline, 4 weeks, 8 weeks, and 12 weeks in group A were 18.23±1.22, 6.14±3.26, 3.21±2.14 and 2.11±2.01 respectively, and in group B, 17.87±1.12, 11.21±6.25, 6.57±4.26 and 6.41±4.17 respectively. The mean MASI significantly reduced in group A compared to group B in the 4th, 8th, and 12th weeks. The present study showed that among group A patients, 56% rated excellent (>75% reduction) in outcome, 32% good (50-75% reduction), 8% moderate (25-50% reduction) and only 4% (<25% reduction) was unsatisfactory and among group B patients, 14% rated excellent in outcome, 28% good, 36% moderate and 22% was unsatisfactory. Overall improvement in our study in group A was 96% and in group B 78%. Side effects were negligible, and all the patients tolerated the treatment well. Conclusion: Based on our results, intralesional Tranexamic acid (10 mg/ml) is more effective and safer than oral Tranexamic acid in the treatment of melasma.

Keywords: intralesional tranexamic acid, melasma, oral tranexamic acid, MASI score

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Authors: Claudia Koby, Merav Boaz, Meirav Zaiger Kober

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Krembo Wings is an all-inclusive youth movement which brings children and youth with any disability together with their able-bodied peers (counselors) for weekly fun and educational social activities. Krembo Wings utilizes a socio-educational framework to create and lead social change through members with and without disabilities. All the work that Krembo Wings engages in stems from its central goal of promoting inclusion and integration using social and psychological theories to develop its unique model and approach. The key to Krembo Wings' approach in promoting inclusion is active participation – each member, with and without disabilities, is enabled to participate to their fullest capacity in the youth movement and its activities. In order for this to be achieved, all activities are adjustable and are modified to fit the abilities of each member. Additionally, youth counselors – most of whom are members without disabilities – go through extensive training in order to act as 'intermediaries' for their partner with disabilities, enabling and facilitating their partner's participation in a way that allows them to be as independent and active as possible. The relationship is one of friendship and not of caretaking. There is always a nurse on-hand to tend to any caretaking needs. Two essential elements of Krembo Wings' model is the broadening of concepts – shifting and changing the understanding of certain concepts such as what it means to be 'independent' or 'able' – and the development of a unique language – creating a language which both reflects and shapes reality. These elements of Krembo Wings' model foster the development of the values of acceptance and appreciation of those who are 'different'. It instills in members and counselors a new way of perceiving the world, one in which inclusion and integration are achievable and natural. Krembo Wings is certain that implementation of this model will promote the participation and inclusion of individuals with disabilities in society while promoting diversity. This model can serve as a platform which can be replicated and adjusted to suit any environment.

Keywords: innovative model for inclusion, socio-educational movement, youth leadership, youth with and without disabilities

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Authors: Saranya Ganapathy, Megha N. Parajulee, Michael San Francisco, Hong Zhang

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Insect pests are a serious threat to agricultural productivity. Use of chemical pesticides, the predominant control method thus far, has resulted in environmental damage, pest resurgence, and negative effects on non-target species. Genetically modified (GM) crops offer a promising alternative, and Bacillus thuringiensis endotoxin genes have played a major role in this respect. However, to overcome insect tolerance issues and to broaden the target range, it is critical to identify alternative-insecticidal toxins working through novel mechanisms. Our research group has identified a kinase from Chilo iridescent virus (CIV; Family Iridoviridae) that has insecticidal activity and designated it as ISTK (Iridovirus Serine/Threonine Kinase). A 35 kDa truncated form of ISTK, designated iridoptin, was obtained during expression and purification of ISTK in the yeast system. This yeast-expressed CIV toxin induced 50% mortality in cotton aphids and 100% mortality in green peach aphids (GPA). Optimized viral genes (o-ISTK and o-IRI) were stably transformed into the model plant, Arabidopsis. PCR analysis of genomic DNA confirmed the presence of the gene insert (oISTK/oIRI) in selected transgenic lines. The further screening was performed to identify the PCR positive lines that showed expression of respective toxins at the polypeptide level using Western blot analysis. The stable lines expressing either of these two toxins induced moderate to very high mortality in GPAs and significantly affected GPA development and fecundity. The aphicidal potential of these transgenic Arabidopsis lines will be presented.

Keywords: Chilo iridescent virus, insecticidal toxin, iridoviruses, plant-incorporated protectants, serine/threonine kinase

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Authors: Radzuan Junin, Dayang Zulaika A. Hasbollah

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The increasing amount of greenhouse gasses in the atmosphere recently has become one of the discussed topics in relation with world’s concern on climate change. Developing countries’ emissions (such as Malaysia) are now seen to surpass developed country’s emissions due to rapid economic development growth in recent decades. This paper presents the potential storage sites suitability and storage capacity assessment for CO2 sequestration in sedimentary basins of Malaysia. This study is the first of its kind that made an identification of potential storage sites and assessment of CO2 storage capacity within the deep saline aquifers in the country. The CO2 storage capacity in saline formation assessment was conducted based on the method for quick assessment of CO2 storage capacity in closed, and semi-closed saline formations modified to suit the geology setting of Malaysia. Then, an integrated approach that involved geographic information systems (GIS) analysis and field data assessment was adopted to provide the potential storage sites and its capacity for CO2 sequestration. This study concentrated on the assessment of major sedimentary basins in Malaysia both onshore and offshore where potential geological formations which CO2 could be stored exist below 800 meters and where suitable sealing formations are present. Based on regional study and amount of data available, there are 14 sedimentary basins all around Malaysia that has been identified as potential CO2 storage. Meanwhile, from the screening and ranking exercises, it is obvious that Malay Basin, Central Luconia Province, West Baram Delta and Balingian Province are respectively ranked as the top four in the ranking system for CO2 storage. 27% of sedimentary basins in Malaysia were evaluated as high potential area for CO2 storage. This study should provide a basis for further work to reduce the uncertainty in these estimates and also provide support to policy makers on future planning of carbon capture and sequestration (CCS) projects in Malaysia.

Keywords: CO₂ storage, deep saline aquifer, GIS, sedimentary basin

Procedia PDF Downloads 362

Authors: Mohamed A. Eid, Sobhy M. Aly

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Background: About 75% of children with spastic hemiplegic cerebral palsy walk independently, but most still show abnormal gait patterns because of contractures across the joints and muscle spasticity. Objective: The purpose of this study was to investigate and compare the effects of extracorporeal shock wave therapy (ESWT) versus functional electrical stimulation (FES) on spasticity, function, and gait parameters in children with hemiplegic cerebral palsy (CP). Methods: A randomized controlled trail was conducted for 45 children with hemiplegic CP ranging in age from 6 to 9 years. They were assigned randomly using opaque envelopes into three groups. Physical Therapy (PT) group consisted of 15 children and received the conventional physical therapy program (CPTP) in addition to ankle foot orthosis (AFO). ESWT group consisted of 15 children and received the CPTP, AFO in addition to ESWT. FES group also consisted of 15 children and received the CPTP, AFO in addition to FES. All groups received the program of treatment 3 days/week for 12 weeks. Evaluation of spasticity by using the Modified Ashworth Scale (MAS), function by using the Pediatric Evaluation Disability Inventory (PEDI) and gait parameters by using the 3-D gait analysis was conducted at baseline and after 12 weeks of the treatment program. Results: Within groups, significant improvements in spasticity, function, and gait (P = 0.05) were observed in both ESWT and FES groups after treatment. While between groups, ESWT group showed significant improvements in all measured variables compared with FES and PT groups (P ˂ 0.05) after treatment. Conclusion: ESWT induced significant improvement than FES in decreasing spasticity and improving function and gait in children with hemiplegic CP. Therefore, ESWT should be included as an adjunctive therapy in the rehabilitation program of these children.

Keywords: cerebral palsy, extracorporeal shock wave therapy, functional electrical stimulation, function, gait, spasticity

Procedia PDF Downloads 133

Authors: Mauricio Gracia, Luis Leal, Bharat Verma

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Computational fluid dynamics (CFD) has become nowadays an important tool in the process of hydrodynamic design of modern ships. CFD is used to model any phenomena related to fluid flow in a control volume like a ship or any offshore structure in the sea. In the present study, the current force drag coefficients for a Colombian Navy Frigate in deep and shallow water are estimated through the application of CFD. The study shows the process of simulating the ship current drag coefficients using the CFD simulations method, which is conducted using STAR-CCM+ software package. The Almirante Padilla class Frigate ship scale model is investigated. The results show the ship current drag coefficient calculated considering a current speed of 1 knot with a 90° drift angle for the full-scale ship. Predicted results were compared against the current drag coefficients published in the Lloyds register OCIMF report. It is shown that the simulation results agree fairly well with the published results and that STAR-CCM+ code can predict current drag coefficients.

Keywords: CFD, current draft coefficient, STAR-CCM+, OCIMF, Bollard pull

Procedia PDF Downloads 184

Authors: A. Vijayendra Chary, R. Hemalatha

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Background: Vitamin D is a potent modulator of the immune system and is involved in regulating cell proliferation and differentiation. Vitamin D deficiency has been linked to increased severity of asthma in children. Asthma has dramatically increased in past decades, particular in developing countries and affects up to 20% of the population. IgE and its receptors, CD23 (FcεRII) and CD 21, play an essential role in all allergic conditions. Methods: A case control study was conducted on asthma and age and sex matched control children. 25 hydroxyvitamin D3 was quantified by HPLC; CD23; and CD21 expression on B cells were performed by flow cytometry. Total Histamine, total IGE and IL-5 and IFN-γ cytokines were determined by ELISA in blood samples of bronchial asthma (n=45) and control children (n=45). Results: The mean ± SE of vitamin D was significantly (p<0.05) low in asthma children (13.6±0.54 ng/mL) than in controls (17.4 ± 0.37 ng/mL). The mean (%) ± SE of CD23 and CD21 expression on B cells were significantly (p<0.01) high in asthma (1.02±0.09; 1.67± 0.13), when compared to controls (0.24±0.01; 0.94±0.03) respectively. The mean± SE of Serum IgE and blood histamine levels in asthma children (354.52 ± 17.33 IU/mL; 53.27 ± 2.54 nM/mL) were increased (P<0.05) when compared to controls (183.12±17.62 IU/mL 39.34±4.16 nM/mL) respectively and IFN-γ (Th1 cytokine) was lower (P<0.01) (16.37±1.27 pg/mL) than in controls (43.34±6.21 pg/mL). Conclusion: Our study provides evidence that low vitamin D levels are associated with increased IgE receptors CD23 and CD21 on B cells. In addition, there was preferential activation of Th2 (IL-5) and suppression of Th1 (IFN-γ) cytokines in children with asthma.

Keywords: bronchial asthma, CD23, IgE, vitamin D

Procedia PDF Downloads 478

Authors: Genesis Julyus T. Agcaoili, Esperanza C. Cabrera

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Thirty (30) isolates of lactic acid bacteria (LAB) from traditionally-prepared fermented products specifically fermented soy-bean paste, fermented mustard and fermented rice-fish mixture were studied for their in vitro antimicrobial and cytotoxic activities. Seventeen (17) isolates were identified as Lactobacillus plantarum, while 13 isolates were identified as Enterococcus spp using 16s rDNA sequences. Disc diffusion method was used to determine the antibacterial activity of LAB against Staphylococcus aureus (ATCC 25923) and Escherichia coli (ATCC 25922), while the modified agar overlay method was used to determine the antifungal activity of LAB isolates on the yeast Candida albicans, and the dermatophytes Microsporum gypseum, Trichophyton rubrum and Epidermophyton floccosum. The filter-sterilized LAB supernatants were evaluated for their cytotoxicity to mammalian colon cancer cell lines (HT-29 and HCT116) and normal human dermal fibrolasts (HDFn) using resazurin assay (PrestoBlueTM). Colchicine was the positive control. No antimicrobial activity was observed against the bacterial test organisms and the yeast Candida albicans. On the other hand, all of the tested LAB strains were fungicidal for all the test dermatophytes. Cytotoxicity index profiles of the supernatants of the 15 randomly picked LABs and negative control (brain heart infussion broth) suggest nontoxicity to the cells when compared to colchicine, whereas all LAB supernatants were found to be cytotoxic to HT-29 and HCT116 colon cancer cell lines. Results provide strong support for the role of the lactic acid bacteria studied in antimicrobial treatment and anticancer therapy.

Keywords: antimicrobial, fermented products, fungicidal activity, lactic acid bacteria, probiotics

Procedia PDF Downloads 241