Search results for: fluid retention

Authors: Adedayo Jeremiah Adeyekun, Samuel Oluwagbemiga Ishola

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This research aims to study the use of traditional building materials for the repair and refurbishment of historic buildings in India and to provide an authentic treatment of historical buildings that will be highly considered by taking into consideration the new standards of rehabilitating process. This can be proven to be an effective solution over modern impervious material due to its compatibility with traditional building methods and materials. For example, their elastoplastic properties allow accommodating movement due to settlement or moisture/temperature changes without cracking. The use of lime also enhances workability, water retention and bond characteristics. Lime is considered to be a natural, traditional material, but it is also sustainable and energy-efficient, with production powered by biomass and emissions up to 25% less than cementitious materials. However, there is a lack of comprehensive data on the impact of lime‐based materials on the energy efficiency and thermal properties of traditional buildings and structures. Although lime mortars, renders and plasters were largely superseded by cement-based products in the first half of the 20th century, lime has a long and proven track record dating back to ancient times. This was used by the Egyptians in 4000BC to construct the pyramids. This doesn't mean that lime is an outdated technology, nor is it difficult to be used as a material. In fact, lime has a growing place in modern construction, with increasing numbers of designers choosing to use lime-based products because of their special properties. To carry out this research, some historic buildings will be surveyed and information will be derived from the textbooks and journals related to Architectural restoration.

Keywords: lime, materials, historic, buildings, sustainability

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Authors: Mengqi Zhu, Chang Nyung Kim

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This study numerically investigates three-dimensional liquid-metal (LM) magnetohydrodynamic (MHD) flows in a misaligned duct under a uniform magnetic field. The duct consists of two misaligned horizontal channels (one is inflow channel, the other is outflow channel) and one central vertical channel. Computational fluid dynamics simulations are performed to predict the behavior of the MHD flows, using commercial code CFX. In the current study, a case with Hartmann number 1000 is considered. The electromagnetic features of LM MHD flows are elucidated to examine the interdependency of the flow velocity, current density, electric potential, pressure drop and Lorentz force. The results show that pressure decreases linearly along the main flow direction.

Keywords: CFX, liquid-metal magnetohydrodynamic flows, misaligned duct, pressure drop

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Authors: B. Oral, C. Bal, M. S. Kar, A. Akgürbüz

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Loss of maxillary central incisors occurs in many patients, and the treatment of young adults with this problem is a challenge for both prosthodontists and orthodontists. Common treatment alternatives are distalization of adjacent teeth and fabrication of a conventional 3-unit fixed partial denture, a single implant supported crown restoration or a resin-bonded fixed partial denture. This case report describes the indication of a resin-bonded fixed partial denture, preparation of the abutment teeth and the prosthetic procedures. The technique described here represents a conservative, esthetically pleasing and rapid solution for the missing maxillary central incisor when implant placement and/or guided bone regeneration techniques are not feasible because of financial, social or time restrictions. In this case a 16 year-old female patient who lost her maxillary left central incisor six years ago in a bicycle accident applied to our clinic with a major complaint of her unaesthetic appearance associated with the loss of her maxillary left central incisor. Although there was an indication for orthodontic treatment because of the limited space at the traumatized area, the patient did not accept to receive any orthodontic procedure. That is why an implant supported restoration could not be an option for the narrow area. Therefore maryland bridge as a minimal invasive dental therapy was preferred as a retention appliance so the patient's aesthetic appearance was restored.

Keywords: Maryland bridge, single tooth restoration, aesthetics, maxillary central incisors

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Authors: Anil P. Dewani, Ravindra L. Bakal, Anil V. Chandewar

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Present work demonstrates the applicability of high-performance liquid chromatography (HPLC) with UV detection for the determination of malondialdehyde as malondialdehyde-thiobarbituric acid complex (MDA-TBA) in-vivo in rats. The HPLC-UV method for MDA-TBA was achieved by isocratic mode on a reverse-phase C18 column (250mm×4.6mm) at a flow rate of 1.0mLmin−1 followed by UV detection at 278 nm. The chromatographic conditions were optimized by varying the concentration and pH followed by changes in percentage of organic phase optimal mobile phase consisted of mixture of water (0.2% Triethylamine pH adjusted to 2.3 by ortho-phosphoric acid) and acetonitrile in ratio (80:20 % v/v). The retention time of MDA-TBA complex was 3.7 min. The developed method was sensitive as limit of detection and quantification (LOD and LOQ) for MDA-TBA complex were (standard deviation and slope of calibration curve) 110 ng/ml and 363 ng/ml respectively. The method was linear for MDA spiked in plasma and subjected to derivatization at concentrations ranging from 100 to 1000 ng/ml. The precision of developed method measured in terms of relative standard deviations for intra-day and inter-day studies was 1.6–5.0% and 1.9–3.6% respectively. The HPLC method was applied for monitoring MDA levels in rats subjected to chronic treatment of ciprofloxacin (CFL) (5mg/kg/day) for 21 days. Results were compared by findings in control group rats. Mean peak areas of both study groups was subjected for statistical treatment to unpaired student t-test to find p-values. The p value was < 0.001 indicating significant results and suggesting increased MDA levels in rats subjected to chronic treatment of CFL of 21 days.

Keywords: MDA, TBA, ciprofloxacin, HPLC-UV

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Authors: Sachin Aggarwal, Sarah Kassinger, Nicholas Hoffman

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Geometry simplification is a key step in performing conjugate heat transfer analysis using CFD. This paper proposes a standard methodology for the geometry simplification of rotating machines, such as electrical generators and electrical motors (both air and liquid-cooled). These machines are extensively deployed throughout the aerospace and automotive industries, where optimization of weight, volume, and performance is paramount -especially given the current global transition to renewable energy sources and vehicle hybridization and electrification. Conjugate heat transfer analysis is an essential step in optimizing their complex design. This methodology will help in reducing convergence issues due to poor mesh quality, thus decreasing computational cost and overall analysis time.

Keywords: CFD, electrical machines, Geometry simplification, heat transfer

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Authors: Saeid Shahraki, Mohammad Mahdi Kaekha

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1030 steel, a kind of carbon steel used in homogenization, cold-forming, quenching, and tempering conditions, is generally utilized in small parts resisting medium stress, such as connection foundations, hydraulic cylinders, tiny gears, pins, clamps, automotive normal forging parts, camshafts, levers, pundits, and nuts. In this study, AC3 software was used to measure the effect of carbon and manganese percentage, dimensions and geometry of pieces, the type of the cooling fluid, temperature, and time on hardness and the content of 1030 steel phases. Next, the results are compared with the analytical values obtained from the Lumped Capacity Method.

Keywords: 1030Steel, AC3software, heat treatment, lumped capacity method

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Authors: Bhupinder Kaur, P. P. Srivastav

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The fruit and vegetable industries are responsible for producing huge amount of waste, which is a problem to environmental safety and should be utilized efficiently. Mango (Mangifera indica L.) is an important commercially grown fruit and referred as the “King of fruits”. In 2015, India was the largest producer (18.506 MT) of mangoes and out of which 9.16 % lost during post-harvest handling. The mango kernel and peel represent approximately 17-22% and 7-22% of the overall mass of fruit respectively and discarded as waste. Hence, an attempt has been made with three mango cultivars (Langra, Dashehari, Fazli) to investigate the effect of cryogenic grinding on various characteristics of mango peel powder (MPP). The cryogenic grinding is an emerging technology which is used for retention of beneficial volatile and bioactive components. The feed rate was highest for Langra followed by Chausa. The samples have 2-4% fat along with significant amount of protein (4-6%) and crude fiber (9-13%). Mango peel is also a good source of minerals such as calcium, potassium, manganese, iron, copper, zinc, and magnesium. Interestingly, the significant amount of essential minerals like phosphorus and chlorine in all the varieties was found with the highest value in Langra (phosphorus 10.83% and chlorine 2.41%) which are not reported earlier. SEM analysis revealed the surface morphology and shape of the particles. Waste utilization is a promising measure from both an environmental and economic point of view. Chemical characterization of the samples indicated its potential to be used for the fortification of food products which in turn reduces hazards due to waste and improve functional quality of the foods.

Keywords: cryogenic grinding, morphological, mineral composition, SEM

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Authors: Nebbat El Amine

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The void is a dust free region inside the dust cloud in the plasma. It is found that the dust grain charge variation lead to the extension of the void. Moreover, for bigger dust grains, it is seen that the wave-like structure recedes when charge variation is dealt with. Furthermore, as the grain-grain distance is inversely proportional to density, the grain-grain interaction gets more important for a denser dust population and is to be included in momentum equation. For the result indicate above, the plasma is considered non viscous. But in fact, it’s not always true. Some authors measured experimentally the viscosity of this background and found that the viscosity of dusty plasma increase with background gas pressure. In this paper, we tack account the viscosity of the fluid, and we compare the result with that found in the recent work.

Keywords: voids, dusty plasmas, variable charge, viscosity

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Authors: Huseyin Gokberk, Shian Gao

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CFD analysis of the relationship between the coefficients of lift and drag with respect to the angle of attack on a NACA 2412 wing section of an RC plane is conducted. Both the 2D and 3D models are investigated with the turbulence model. The 2D analysis has a free stream velocity of 10m/s at different AoA of 0°, 2°, 5°, 10°, 12°, and 15°. The induced drag and drag coefficient increased throughout the changes in angles even after the critical angle had been exceeded, whereas the lift force and coefficient of lift increased but had a limit at the critical stall angle, which results in values to reduce sharply. Turbulence flow characteristics are analysed around the aerofoil with the additions caused due to a finite 3D model. 3D results highlight how wing tip vortexes develop and alter the flow around the wing with the effects of the tapered configuration.

Keywords: CFD, turbulence modelling, aerofoil, angle of attack

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Authors: Won Jun Jo, Man Young Kim

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To meet stringent diesel particulate matter regulations, DPF system is essential after treatment technology providing exceptional reliability and filtration performance. At low load driving conditions, the passive type of DPF system is ineffective for regeneration method due to the inadequate of engine exhaust heat in removing accumulated soot from the filter. Therefore, DPF cleaning device is necessary to remove the soot particles. In this work, the numerical analysis on the active regeneration of DPF in DPF cleaning device is performed to find the optimum operating conditions. In order to find the DPF regeneration characteristics during active regeneration, 5 different initial soot loading condition are investigated. As the initial soot mass increases, the maximum temperature of DPF and regeneration rate also increase.

Keywords: active regeneration, DPF cleaning device, pressure drop, Diesel Particulate Filter, particulate matters, computational fluid dynamics

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Authors: Jayme R. T. Silva, Paulo G. P. Toro, Angelo Passaro, Giannino P. Camillo, Antonio C. Oliveira

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An in-house C++ code has been developed, at the Prof. Henry T. Nagamatsu Laboratory of Aerothermodynamics and Hypersonics from the Institute of Advanced Studies (Brazil), to estimate the aerothermodynamic properties around the Hypersonic Vehicle Integrated to the Scramjet. In the future, this code will be applied to the design of the Brazilian Scramjet Technological Demonstrator 14-X B. The first step towards accomplishing this objective, is to apply the in-house C++ code at the leading edge of a flat plate, simulating the leading edge of the 14-X Hypersonic Vehicle, making possible the wave phenomena of oblique shock and boundary layer to be analyzed. The development of modern hypersonic space vehicles requires knowledge regarding the characteristics of hypersonic flows in the vicinity of a leading edge of lifting surfaces. The strong interaction between a shock wave and a boundary layer, in a high supersonic Mach number 4 viscous flow, close to the leading edge of the plate, considering no slip condition, is numerically investigated. The small slip region is neglecting. The study consists of solving the fluid flow equations for unstructured meshes applying the SIMPLE algorithm for Finite Volume Method. Unstructured meshes are generated by the in-house software ‘Modeler’ that was developed at Virtual’s Engineering Laboratory from the Institute of Advanced Studies, initially developed for Finite Element problems and, in this work, adapted to the resolution of the Navier-Stokes equations based on the SIMPLE pressure-correction scheme for all-speed flows, Finite Volume Method based. The in-house C++ code is based on the two-dimensional Navier-Stokes equations considering non-steady flow, with nobody forces, no volumetric heating, and no mass diffusion. Air is considered as calorically perfect gas, with constant Prandtl number and Sutherland's law for the viscosity. Solutions of the flat plate problem for Mach number 4 include pressure, temperature, density and velocity profiles as well as 2-D contours. Also, the boundary layer thickness, boundary conditions, and mesh configurations are presented. The same problem has been solved by the academic license of the software Ansys Fluent and for another C++ in-house code, which solves the fluid flow equations in structured meshes, applying the MacCormack method for Finite Difference Method, and the results will be compared.

Keywords: boundary-layer, scramjet, simple algorithm, shock wave

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Authors: Linyu Wang, Liguo Qiao, Jianhong Xiang, Hao Xu

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In semantic communication, the existing joint Source Channel coding (JSCC) wireless communication system without pilot has unstable transmission performance and can not effectively capture the global information and location information of images. In this paper, a pilot-free image transmission system of joint source channel based on multi-level semantic information (Multi-level JSCC) is proposed. The transmitter of the system is composed of two networks. The feature extraction network is used to extract the high-level semantic features of the image, compress the information transmitted by the image, and improve the bandwidth utilization. Feature retention network is used to preserve low-level semantic features and image details to improve communication quality. The receiver also is composed of two networks. The received high-level semantic features are fused with the low-level semantic features after feature enhancement network in the same dimension, and then the image dimension is restored through feature recovery network, and the image location information is effectively used for image reconstruction. This paper verifies that the proposed multi-level JSCC algorithm can effectively transmit and recover image information in both AWGN channel and Rayleigh fading channel, and the peak signal-to-noise ratio (PSNR) is improved by 1~2dB compared with other algorithms under the same simulation conditions.

Keywords: deep learning, JSCC, pilot-free picture transmission, multilevel semantic information, robustness

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Authors: D. Serero, L. Couton, J. D. Parisse, R. Leroy

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In urban planning, an increasing number of cities require wind analysis to verify comfort of public spaces and around buildings. These studies are made using computer fluid dynamic simulation (CFD). However, this technique is often based on wind information taken from meteorological stations located at several kilometers of the spot of analysis. The approximated input data on project surroundings produces unprecise results for this type of analysis. They can only be used to get general behavior of wind in a zone but not to evaluate precise wind speed. This paper presents another approach to this problem, based on collecting wind data and generating an urban wind cartography using connected ultrasound anemometers. They are wireless devices that send immediate data on wind to a remote server. Assembled in array, these devices generate geo-localized data on wind such as speed, temperature, pressure and allow us to compare wind behavior on a specific site or building. These Netatmo-type anemometers communicate by wifi with central equipment, which shares data acquired by a wide variety of devices such as wind speed, indoor and outdoor temperature, rainfall, and sunshine. Beside its precision, this method extracts geo-localized data on any type of site that can be feedback looped in the architectural design of a building or a public place. Furthermore, this method allows a precise calibration of a virtual wind tunnel using numerical aeraulic simulations (like STAR CCM + software) and then to develop the complete volumetric model of wind behavior over a roof area or an entire city block. The paper showcases connected ultrasonic anemometers, which were implanted for an 18 months survey on four study sites in the Grand Paris region. This case study focuses on Paris as an urban environment with multiple historical layers whose diversity of typology and buildings allows considering different ways of capturing wind energy. The objective of this approach is to categorize the different types of wind in urban areas. This, particularly the identification of the minimum and maximum wind spectrum, helps define the choice and performance of wind energy capturing devices that could be implanted there. The localization on the roof of a building, the type of wind, the altimetry of the device in relation to the levels of the roofs, the potential nuisances generated. The method allows identifying the characteristics of wind turbines in order to maximize their performance in an urban site with turbulent wind.

Keywords: computer fluid dynamic simulation in urban environment, wind energy harvesting devices, net-zero energy building, urban wind behavior simulation, advanced building skin design methodology

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Authors: Larbi Hammadi, N. Boudjenane, N. Benhallou, R. Houjedje, R. Reffis, M. Belhadri

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Many of clays exhibited the thixotropic behavior in which, the apparent viscosity of material decreases with time of shearing at constant shear rate. The structural kinetic model (SKM) was used to characterize the thixotropic behavior of two different kinds of clays used in fabrication of ceramic. Clays selected for analysis represent the fluid and semisolid clays materials. The SKM postulates that the change in the rheological behavior is associated with shear-induced breakdown of the internal structure of the clays. This model for the structure decay with time at constant shear rate assumes nth order kinetics for the decay of the material structure with a rate constant.

Keywords: ceramic, clays, structural kinetic model, thixotropy, viscosity

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Authors: Andra Yount

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The purpose of this research project is to understand how focusing on movement can help English language learners acquire better reading, writing, and speaking skills. More specifically, this case study tests how Laban movement analysis, a tool often used in dance and physical education classes, contributes to advanced-level high school students’ English language acquisition at an international Swiss boarding school. This article shares theoretical bases for and findings from a teaching experiment in which LMA categories (body, effort, space, and shape) were adapted and introduced to students to encourage basic language acquisition and also cultural awareness and sensitivity. As part of the participatory action research process, data collection included pseudonym-protected questionnaires and written/video-taped responses to LMA language and task prompts. Responses from 43 participants were evaluated to determine the efficacy of using this system. Participants (ages 16-19) were enrolled in advanced English as an Additional Language (EAL) courses at a private, co-educational Swiss international boarding school. Final data analysis revealed that drawing attention to movement using LMA language as a stimulus creates better self-awareness and understanding/retention of key literary concepts and vocabulary but does not necessarily contribute to greater cultural sensitivity or eliminate the use of problematic (sexist, racist, or classist) language. Possibilities for future exploration and development are also explored.

Keywords: dance, English, Laban, pedagogy

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Authors: Zdzislaw Kaminski, Zbigniew Czyz, Krzysztof Skiba

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This paper discusses the CFD simulation of a flow around a rotor of a Vertical Axis Wind Turbine. Numerical simulation, unlike experiments, enables us to validate project assumptions when it is designed and avoid a costly preparation of a model or a prototype for a bench test. CFD simulation enables us to compare characteristics of aerodynamic forces acting on rotor working surfaces and define operational parameters like torque or power generated by a turbine assembly. This research focused on the rotor with the blades capable of modifying their working surfaces, i.e. absorbing wind kinetic energy. The operation of this rotor is based on adjusting angular aperture α of the top and bottom parts of the blades mounted on an axis. If this angular aperture α increases, the working surface which absorbs wind kinetic energy also increases. The operation of turbines is characterized by parameters like the angular aperture of blades, power, torque, speed for a given wind speed. These parameters have an impact on the efficiency of assemblies. The distribution of forces acting on the working surfaces in our turbine changes according to the angular velocity of the rotor. Moreover, the resultant force from the force acting on an advancing blade and retreating blade should be as high as possible. This paper is part of the research to improve an efficiency of a rotor assembly. Therefore, using simulation, the courses of the above parameters were studied in three full rotations individually for each of the blades for three angular apertures of blade working surfaces, i.e. 30 °, 60 °, 90 °, at three wind speeds, i.e. 4 m / s, 6 m / s, 8 m / s and rotor speeds ranging from 100 to 500 rpm. Finally, there were created the characteristics of torque coefficients and power as a function of time for each blade separately and for the entire rotor. Accordingly, the correlation between the turbine rotor power as a function of wind speed for varied values of rotor rotational speed. By processing this data, the correlation between the power of the turbine rotor and its rotational speed for each of the angular aperture of the working surfaces was specified. Finally, the optimal values, i.e. of the highest output power for given wind speeds were read. The research results in receiving the basic characteristics of turbine rotor power as a function of wind speed for the three angular apertures of the blades. Given the nature of rotor operation, the growth in the output turbine can be estimated if angular aperture of the blades increases. The controlled adjustment of angle α enables a smooth adjustment of power generated by a turbine rotor. If wind speed is significant, this type of adjustment enables this output power to remain at the same level (by reducing angle α) with no risk of damaging a construction. This work has been financed by the Polish Ministry of Science and Higher Education.

Keywords: computational fluid dynamics, numerical analysis, renewable energy, wind turbine

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Authors: Md. Abdul Hannan

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Two organophosphorus compounds, namely diethyloxymethyl-9-oxa-10- phosphaphenanthrene-10-oxide (DOPAC) and diethyl (2,2-diethoxyethyl) phosphonate (DPAC) were applied on cotton cellulose to impart non-carcinogenic and durable (in alkaline washing) flame retardant property to it. Some acidic catalysts, sodium dihydrogen phosphate (NaH2PO4), ammonium dihydrogen phosphate (NH4H2PO4) and phosphoric acid (H3PO4) were successfully used. Synergistic acidic catalyzing effect of NaH2PO4+H3PO4 and NaH2PO4+NH4H2PO4 was also investigated. Appreciable limiting oxygen index (LOI) value of 23.2% was achieved in case of the samples treated with flame retardant (FR) compound DPAC along with the combined acidic catalyzing effect. A distinguishing outcome of total heat of combustion (THC) 3.27 KJ/g was revealed during pyrolysis combustion flow calorimetry (PCFC) test of the treated sample. In respect of thermal degradation, low temperature dehydration in conjugation with sufficient amount of char residue (30.5%) was obtained in case of DPAC treated sample. Consistently, the temperature of peak heat release rate (TPHRR) (325°C) of DPAC treated sample supported the expected low temperature pyrolysis in condensed phase mechanism. Subsequent thermogravimetric analysis (TGA) also reported inspiring weight retention% of the treated samples. Furthermore, for both of the flame retardant compounds, effect of different catalysts, considering both individual and combined, effect of solvents and overall the optimization of the process parameters were studied in detail.

Keywords: cotton cellulose, organophosphorus flame retardant, acetal linkage, THC, HRR, PHHR, char residue, LOI

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Authors: Rim Ben Kalifa, Sabra Habli, Nejla Mahjoub Saïd, Hervé Bournot, Georges Le Palec

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The present study treats different phenomena taking place in a configuration of air jet impinging on a flat surface in a coflow stream. A Computational Fluid Dynamics study is performed using the Reynolds-averaged Navier–Stokes equations by means of the Reynolds Stress Model (RSM) second order turbulent closure model. The results include mean and turbulent velocities and quantify the large effects of the coflow stream on an impinging air jet. The study of the jet in a no-directed coflow stream shows the presence of a phenomenon of recirculation near the flat plate. The influence of the coflow velocity ratio on the behavior of an impinging plane jet was also numerically investigated. The coflow stream imposed noticeable restrictions on the spreading of the impinging jet. The results show that the coflow stream decreases considerably the entrainment of air jet.

Keywords: turbulent jet, turbulence models, coflow stream, velocity ratio

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Authors: Mustapha Rilwan Adewale, Salau Ayobami Muhammed

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This study focuses on the heat transfer analysis of magneto-hydrodynamics (MHD) squeezing flow between parallel disks, considering a viscous incompressible fluid. The upper disk exhibits both upward and downward motion, while the lower disk remains stationary but permeable. By employing similarity transformations, a system of nonlinear ordinary differential equations is derived to describe the flow behavior. To solve this system, a numerical approach, namely the Chebyshev collocation method, is utilized. The study investigates the influence of flow parameters and compares the obtained results with existing literature. The significance of this research lies in understanding the heat transfer characteristics of MHD squeezing flow, which has practical implications in various engineering and industrial applications. By employing the similarity transformations, the complex governing equations are simplified into a system of nonlinear ordinary differential equations, facilitating the analysis of the flow behavior. To obtain numerical solutions for the system, the Chebyshev collocation method is implemented. This approach provides accurate approximations for the nonlinear equations, enabling efficient computations of the heat transfer properties. The obtained results are compared with existing literature, establishing the validity and consistency of the numerical approach. The study's major findings shed light on the influence of flow parameters on the heat transfer characteristics of the squeezing flow. The analysis reveals the impact of parameters such as magnetic field strength, disk motion amplitude, fluid viscosity on the heat transfer rate between the disks, the squeeze number(S), suction/injection parameter(A), Hartman number(M), Prandtl number(Pr), modified Eckert number(Ec), and the dimensionless length(δ). These findings contribute to a comprehensive understanding of the system's behavior and provide insights for optimizing heat transfer processes in similar configurations. In conclusion, this study presents a thorough heat transfer analysis of magneto-hydrodynamics squeezing flow between parallel disks. The numerical solutions obtained through the Chebyshev collocation method demonstrate the feasibility and accuracy of the approach. The investigation of flow parameters highlights their influence on heat transfer, contributing to the existing knowledge in this field. The agreement of the results with previous literature further strengthens the reliability of the findings. These outcomes have practical implications for engineering applications and pave the way for further research in related areas.

Keywords: squeezing flow, magneto-hydro-dynamics (MHD), chebyshev collocation method(CCA), parallel manifolds, finite difference method (FDM)

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Authors: Ye Ling, Ruan Haihui

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Aqueous Zn-ion hybrid supercapacitors (AZHSCs) pertain to a new type of electrochemical energy storage device that has received considerable attention. They integrate the advantages of high-energy Zn-ion batteries and high-power supercapacitors to meet the demand for low-cost, long-term durability, and high safety. Nevertheless, the challenge caused by the finite ion adsorption/desorption capacity of carbon electrodes gravely limits their energy densities. This work describes titanium nitride@nitrogen-doped carbon nanocage (TiN@NCNC) composite cathodes for AZHSCs to achieve a greatly improved energy density, and the composites can be facile synthesized based on the calcination of a mixture of tetrabutyl titanate and zeolitic imidazolate framework-8 in argon atmosphere. The resulting composites are featured by the ultra-fine TiN particles dispersed uniformly on the NCNC surfaces, enhancing the Zn2+ storage capabilities. Using TiN@NCNC cathodes, the AZHSCs can operate stably with a high energy density of 154 Wh kg-¹ at a specific power of 270 W kg-¹ and achieve a remarkable capacity retention of 88.9% after 104 cycles at 5 A g-¹. At an extreme specific power of 8.7 kW kg-1, the AZHSCs can retain an energy density of 97.2 Wh kg-1. With these results, we stress that the TiN@NCNC cathodes render high-performance AZHSCs, and the facile one-pot method can easily be scaled up, which enables AZHSCs a new energy-storage component for managing intermitted renewable energy sources.

Keywords: Zn-ion hybrid supercapacitors, ion absorption/desorption reactions, titanium nitride, zeolitic imidazolate framework-8

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Authors: M. Meenasaranya, S. Saravanan

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Nonlinear stability analysis is carried out to determine the effect of surface temperature modulation in an infinite horizontal porous layer heated from below. The layer is saturated by an electrically conducting, viscous, incompressible and Newtonian fluid. The Brinkman model is used for momentum equation, and the Boussinesq approximation is invoked. The system is assumed to be bounded by rigid boundaries. The energy theory is implemented to find the global exponential stability region of the considered system. The results are analysed for arbitrary values of modulation frequency and amplitude. The existence of subcritical instability region is confirmed by comparing the obtained result with the known linear result. The vertical magnetic field is found to stabilize the system.

Keywords: Brinkman model, energy method, magnetic field, surface temperature modulation

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Authors: Amina Ramadni, Safia Taleb, André Dératani

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The present study presents, firstly, to characterize the physicochemical quality of brackish groundwater of the Terminal Complex (TC) from the region of Eloued-souf and to investigate the presence of fluoride, and secondly, to study the comparison of adsorbing power of three materials, such as (activated alumina AA, sodium clay SC and hydroxyapatite HAP) against the groundwater in the region of Eloued-souf. To do this, a sampling campaign over 16 wells and consumer taps was undertaken. The results show that the groundwater can be characterized by very high fluoride content and excessive mineralization that require in some cases, specific treatment before supply. The study of adsorption revealed removal efficiencies fluoride by three adsorbents, maximum adsorption is achieved after 45 minutes at 90%, 83.4% and 73.95%, and with an adsorbed fluoride content of 0.22 mg/L, 0.318 mg/L and 0.52 mg/L for AA, HAP and SC, respectively. The acidity of the medium significantly affects the removal fluoride. Results deducted from the adsorption isotherms also showed that the retention follows the Langmuir model. The adsorption tests by adsorbent materials show that the physicochemical characteristics of brackish water are changed after treatment. The adsorption mechanism is an exchange between the OH^- ions and fluoride ions. Three materials are proving to be effective adsorbents for fluoride removal that could be developed into a viable technology to help reduce the salinity of the Saharan hyper-fluorinated waters. Finally, a comparison between the results obtained from the different adsorbents allowed us to conclude that the defluoridation by AA is the process of choice for many waters of the region of Eloued-souf, because it was shown to be a very interesting and promising technique.

Keywords: fluoride removal, hydrochemical characterization of groundwater, natural materials, nanofiltration

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Authors: Stefana Francisca Lupu, Jasmin Chantah, Mara Krone, Ingo Roden, Stephan Bongard, Gunter Kreutz

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Long-term music interventions could enhance both musical and nonmusical skills. The present study was designed to explore cognitive, socio-emotional, and musical development in a longitudinal setting. Third-graders (N = 184: 87 male, 97 female; mean age = 8.61 years; 115 native German and 69 migrant children) were randomly assigned to two intervention groups (music and maths) and a control group over a period of one school-year. At baseline, children in these groups were similar in basic cognitive skills, with a trend of advantage in the control group. Dependent measures included the culture fair intelligence test CFT 20-R; the questionnaire of emotional and social school experience for grade 3 and 4 (FEESS 3-4), the test of resources in childhood and adolescence (FRKJ 8-16), the test of language proficiency for German native and non-native primary school children (SFD 3), the reading comprehension test (ELFE 1-6), the German math test (DEMAT 3+) and the intermediate measures of music audiation (IMMA). Data were collected two times at the beginning (T1) and at the end of the school year (T2). A third measurement (T3) followed after a six months retention period. Data from baseline and post-intervention measurements are currently being analyzed. Preliminary results of all three measurements will be presented at the conference.

Keywords: musical training, primary-school German and migrant children, socio-emotional skills, transfer

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Authors: Hasan Jumaah Mrayeh, Fue-Sang Lien

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ANSYS Fluent will be used to simulate Computational Fluid Dynamics (CFD) for an efficient lens and nozzle design which will be explained in this paper. We have designed and characterized an aerodynamic lens and a divergent nozzle for focusing flow that transmits sub 25 nm particles through the aerodynamic lens. The design of the lens and nozzle has been improved using CFD for particle trajectories. We obtained a case for calculating nanoparticles (25 nm) flowing through the aerodynamic lens and divergent nozzle. Nanoparticles are transported by air, which is pumped into the aerodynamic lens through the nozzle at 1 atmospheric pressure. We have also developed a computational methodology that can determine the exact focus characteristics of aerodynamic lens systems. Particle trajectories were traced using the Lagrange approach. The simulation shows the ability of the aerodynamic lens to focus on 25 nm particles after using a divergent nozzle.

Keywords: aerodynamic lens, divergent nozzle, ANSYS Fluent, Lagrange approach

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Authors: Jack Johnstone

Abstract:

This research presents postcolonial translation as an approach to eradicate traces of colonialism in former colonies. An example of demonstrating postcolonial translation in the Indonesian context is in Hasan Aspahani's Chairil, a biographical narrative and history book based on the personal life of a well-known Indonesian poet and writer, Chairil Anwar (1922-1949) in Dutch occupied Indonesia. This postcolonial translation approach has been applied in the first five chapters on his early years under Dutch colonization, in an attempt to show a postcolonialised TT. This approach aims to demonstrate the postcolonial refutation of the Dutch colonial language to convey the Indonesian setting to target readers. It is also designed to explicate the summary of the book as well as my attempt to apply postcolonial translation as a strategy to reject the Dutch colonial terms in this book. The data conveys 26 important examples of the ST and TT, in consideration of the chosen three factors of culture, forced-Europeanisation, and cross-genre between a biographical narrative and history under categories of Cultural Bound Objects, Politics and Place. However, the 10 selected examples will be analyzed in the Analysis Chapter, which are discussed at word, sentence, and paragraph level. As well, the translation strategies used, namely retention, substitution and specification on four main examples, on the methods utilized to achieve a postcolonialised translation that attempts to 1) examine the way the alteration of the TT can affect the message portrayed within the ST, 2) show the notion of disagreement between the Dutch colonizers and colonized Indonesians on their views on the way Indonesia should be governed and 3) present a translation that reverses the inequality between the superior colonials and inferior Indigenous Indonesians during the Dutch colonial era.

Keywords: Chairil, Dutch colonialism, Indonesia, postcolonial translation

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Authors: Hadiseh Hosamirudsari, Farhad Afsarikordehmahin, Pooria Sekhavatfar

Abstract:

Concomitant cortical blindness and deafness that follow varicella zoster virus (VZV) infection is rare. We describe a case of ophthalmic zoster that caused cortical blindness and deafness after central nervous system (CNS) involvement. A 42-year old, HIV infected woman has developed progressive blurry vision and deafness, 4 weeks after ophthalmic zoster. A physical examination and positive VZV polymerase chain reaction (PCR) of cerebrospinal fluid (CSF) suggested VZV encephalitis. Complication of VZV encephalitis is considered as the cause of blindness and deafness. In neurological deficit patient especially with a history of herpes zoster, VZV infection should be regarded as the responsible agent in inflammatory disorders of nervous system. The immunocompromised state of patient (including HIV) is as important an agent as VZV infection in developing the disease.

Keywords: blindness, deafness, hiv, VZV encephalitis

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Authors: Suzan Sami Ibrahim, Mohamed Gad Shahien, Ali Quarny Seliem, Mostafa Ragab Abukhadra

Abstract:

Pegmatite quartz deposits of Marwit Rod El Leqah area classify as medium purity quartz with 99.575 % average SiO2 content and therefore do not match the requirements of high technical applications (99.8 % SiO2 for solar cells, 99.8% SiO2 for electronics). Petrographic field and petrographic investigations reveal that, the reduction of the silica content attributed mainly to impurities of iron oxide, muscovite, rutile, orthoclase, granitic rafts and fluid inclusions. Such impurities resulted in raising Fe2O3, Al2O3, MgO, CaO, K2O and Na2O relative to the silica content. Structural impurities are the main source of trace elements in the quartz samples.

Keywords: High purity quartz, High-tech applications, solid impurities, structural impurities

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Authors: Ahmed Bensreti, Mohamed Gouarsha

Abstract:

This paper presents a review of the pressure surge simulations carried out for Phase III of the Man Made River project in Libya with particular emphasis on the transient generated by simultaneous pump trips at Al Gardabiya Pump Station. The omission of the surge vessel check valve and bypass system on the grounds of cost, ease of design, and construction will result in, as expected, increased surge fluctuations as the damping effect in the form was removed. From the hydraulic and control requirements, it is recommended for Al Gardabiya Pump station that the check valve and check valve bypass be included in the final surge vessel design.

Keywords: computational fluid dynamics, surge vessel design, transient surge analysis, water pipe hydraulics

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Authors: Delara Soltani, Sajad Alimohammadi, Tim Persoons

Abstract:

Microfluidic technology reveals a new area of research in drug delivery, biomedical diagnostics, and the food and chemical industries. Mixing is an essential part of microfluidic devices. There is a need for fast and homogeneous mixing in microfluidic devices. On the other hand, mixing is difficult to achieve in microfluidic devices because of the size and laminar flow in these devices. In this study, a hybrid passive micromixer of a curved channel with obstacles inside the channel is designed. The computational fluid dynamic method is employed to solve governing equations. The results show that using obstacles can improve mixing efficiency in spiral micromixers. the effects of Reynolds number, number, and position of baffles are investigated. In addition, the effect of baffles on pressure drop is presented. this novel micromixer has the potential to utilize in microfluidic devices.

Keywords: CFD, micromixer, microfluidics, spiral, reynolds number

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Authors: Biao Sun, Tejas Bhatelia, Vishnu Pareek, Ranjeet Utikar, Moses Tadé

Abstract:

Additive manufacturing (AM), commonly known as 3D printing, with the continuing advances in parallel processing and computational modeling, has created a paradigm shift (with significant radical thinking) in the design and operation of chemical processing plants, especially LNG plants. With the rising energy demands, environmental pressures, and economic challenges, there is a continuing industrial need for disruptive technologies such as AM, which possess capabilities that can drastically reduce the cost of manufacturing and operations of chemical processing plants in the future. However, the continuing challenge for 3D printing is its lack of adaptability in re-designing the process plant equipment coupled with the non-existent theory or models that could assist in selecting the optimal candidates out of the countless potential fabrications that are possible using AM. One of the most common packings used in the LNG process is structured packing in the packed column (which is a unit operation) in the process. In this work, we present an example of an optimum strategy for the application of AM to this important unit operation. Packed columns use a packing material through which the gas phase passes and comes into contact with the liquid phase flowing over the packing, typically performing the necessary mass transfer to enrich the products, etc. Structured packing consists of stacks of corrugated sheets, typically inclined between 40-70° from the plane. Computational Fluid Dynamics (CFD) was used to test and model various geometries to study the governing hydrodynamic characteristics. The results demonstrate that the costly iterative experimental process can be minimized. Furthermore, they also improve the understanding of the fundamental physics of the system at the multiscale level. SpiroPak, patented by Curtin University, represents an innovative structured packing solution currently at a technology readiness level (TRL) of 5~6. This packing exhibits remarkable characteristics, offering a substantial increase in surface area while significantly enhancing hydrodynamic and mass transfer performance. Recent studies have revealed that SpiroPak can reduce pressure drop by 50~70% compared to commonly used commercial packings, and it can achieve 20~50% greater mass transfer efficiency (particularly in CO2 absorption applications). The implementation of SpiroPak has the potential to reduce the overall size of columns and decrease power consumption, resulting in cost savings for both capital expenditure (CAPEX) and operational expenditure (OPEX) when applied to retrofitting existing systems or incorporated into new processes. Furthermore, pilot to large-scale tests is currently underway to further advance and refine this technology.

Keywords: Additive Manufacturing (AM), 3D printing, Computational Fluid Dynamics (CFD, structured packing (SpiroPak)

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