Search results for: carbon element

Authors: Muhamad Syafiq Hakimi Kamaruddin, Norhidayah Suleiman

Abstract:

Ginger extracts (Zingiber officinale Rosc.) have been attributed therapeutic properties primarily as antioxidant, anticancer, and anti-inflammatory properties. Conventional extractions including Soxhlet and maceration are commonly used to extract the bioactive compounds from plant material. Nevertheless, high energy consumption and being non-environmentally friendly are the predominant limitations of the conventional extractions method. Herein, green technology, namely supercritical carbon dioxide (scCO2) extraction, is used to study process variables' effects on extract yields. Herein, green technology, namely supercritical carbon dioxide (scCO2) extraction, is used to study process variables' effects on extract yields. A pressure (10-30 MPa), temperature (40-60 °C), and median particle size (300-600 µm) were conducted at a CO2 flow rate of 0.9 ± 0.2 g/min for 120 mins. The highest overall yield was 4.58% obtained by the scCO2 extraction conditions of 300 bar and 60 °C with 300µm of ginger powder for 120 mins. In comparison, the yield of the extract was increased considerably within a short extraction time. The results show that scCO2 has a remarkable ability over ginger extract and is a promising technology for extracting bioactive compounds from plant material.

Keywords: conventional, ginger, non-environmentally, supercritical carbon dioxide, technology

Procedia PDF Downloads 116

Authors: Debananda Mohapatra, Subramanya Badrayyana, Smrutiranjan Parida

Abstract:

Recognizing the upcoming era of carbon nanostructures and their revolutionary applications, we investigated the formation and supercapacitor application of highly pure and hydrophilic carbon nano-onions (CNOs) by economical one-step flame-synthesis procedure. The facile and scalable method uses easily available organic carbon source such as clarified butter, restricting the use of any catalyst, sophisticated instrumentation, high vacuum and post processing purification procedure. The active material was conformally coated onto a locally available cotton wipe by “sonicating and drying” process to obtain novel, lightweight, inexpensive, flexible, binder-free electrodes with strong adhesion between nanoparticles and porous wipe. This interesting electrode with CNO as the active material delivers a specific capacitance of 102.16 F/g, the energy density of 14.18 Wh/kg and power density of 2448 W/kg which are the highest values reported so far in symmetrical two electrode cell configuration with 1M Na2SO4 as an electrolyte. Incorporation of CuO nanoparticles to these functionalized CNOs by one-step hydrothermal method add up to a significant specific capacitance of 420 F/g with deliverable energy and power density at 58.33 Wh/kg and 4228 W/kg, respectively. The free standing CNOs, as well as CNO-CuO composite electrode, showed an excellent cyclic performance and stability retaining 95 and 90% initial capacitance even after 5000 charge-discharge cycles at a current density of 5 A/g. This work presents a new platform for high performance supercapacitors for next generation wearable electronic devices.

Keywords: binder-free, flame synthesis, flexible, carbon nano-onion

Procedia PDF Downloads 197

Authors: Christobel Gondwe, Yongtao Lu, Claudia Mazzà, Xinshan Li

Abstract:

Skeletal muscle plays an important role in the human body system and function by generating voluntary forces and facilitating body motion. However, The mechanical properties and behaviour of skeletal muscle are still not comprehensively known yet. As such, various robust engineering techniques have been applied to better elucidate the mechanical behaviour of skeletal muscle. It is considered that muscle mechanics are highly governed by the architecture of the fibre orientations. Therefore, the aim of this study was to investigate the effect of different fibre orientations on the mechanical behaviour of skeletal muscle.In this study, a continuum mechanics approach–finite element (FE) analysis was applied to the left bicep femoris long head to determine the contractile mechanism of the muscle using Hill’s three-element model. The geometry of the muscle was segmented from the magnetic resonance images. The muscle was modelled as a quasi-incompressible hyperelastic (Mooney-Rivlin) material. Two types of fibre orientations were implemented: one with the idealised fibre arrangement, i.e. parallel single-direction fibres going from the muscle origin to insertion sites, and the other with curved fibre arrangement which is aligned with the muscle shape.The second fibre arrangement was implemented through the finite element method; non-uniform rational B-spline (FEM-NURBs) technique by means of user material (UMAT) subroutines. The stress-strain behaviour of the muscle was investigated under idealised exercise conditions, and will be further analysed under physiological conditions. The results of the two different FE models have been outputted and qualitatively compared.

Keywords: FEM-NURBS, finite element analysis, Mooney-Rivlin hyperelastic, muscle architecture

Procedia PDF Downloads 479

Authors: Dragan Ribarić

Abstract:

We employ the so-called problem-dependent linked interpolation concept to develop two cubic 4-node quadrilateral Mindlin plate finite elements with 12 external degrees of freedom. In the problem-independent linked interpolation, the interpolation functions are independent of any problem material parameters and the rotation fields are not expressed in terms of the nodal displacement parameters. On the contrary, in the problem-dependent linked interpolation, the interpolation functions depend on the material parameters and the rotation fields are expressed in terms of the nodal displacement parameters. Two cubic 4-node quadrilateral plate elements are presented, named Q4-U3 and Q4-U3R5. The first one is modelled with one displacement and two rotation degrees of freedom in every of the four element nodes and the second element has five additional internal degrees of freedom to get polynomial completeness of the cubic form and which can be statically condensed within the element. Both elements are able to pass the constant-bending patch test exactly as well as the non-zero constant-shear patch test on the oriented regular mesh geometry in the case of cylindrical bending. In any mesh shape, the elements have the correct rank and only the three eigenvalues, corresponding to the solid body motions are zero. There are no additional spurious zero modes responsible for instability of the finite element models. In comparison with the problem-independent cubic linked interpolation implemented in Q9-U3, the nine-node plate element, significantly less degrees of freedom are employed in the model while retaining the interpolation conformity between adjacent elements. The presented elements are also compared to the existing problem-independent quadratic linked-interpolation element Q4-U2 and to the other known elements that also use the quadratic or the cubic linked interpolation, by testing them on several benchmark examples. Simple functional upgrading from the quadratic to the cubic linked interpolation, implemented in Q4-U3 element, showed no significant improvement compared to the quadratic linked form of the Q4-U2 element. Only when the additional bubble terms are incorporated in the displacement and rotation function fields, which complete the full cubic linked interpolation form, qualitative improvement is fulfilled in the Q4-U3R5 element. Nevertheless, the locking problem exists even for the both presented elements, like in all pure displacement elements when applied to very thin plates modelled by coarse meshes. But good and even slightly better performance can be noticed for the Q4-U3R5 element when compared with elements from the literature, if the model meshes are moderately dense and the plate thickness not extremely thin. In some cases, it is comparable to or even better than Q9-U3 element which has as many as 12 more external degrees of freedom. A significant improvement can be noticed in particular when modeling very skew plates and models with singularities in the stress fields as well as circular plates with distorted meshes.

Keywords: Mindlin plate theory, problem-independent linked interpolation, problem-dependent interpolation, quadrilateral displacement-based plate finite elements

Procedia PDF Downloads 312

Authors: Grzegorz Raniszewski, Zbigniew Kolacinski, Lukasz Szymanski, Slawomir Wiak, Lukasz Pietrzak, Dariusz Koza

Abstract:

One of the most promising area for carbon nanotubes (CNTs) application is medicine. One of the most devastating diseases is cancer. Carbon nanotubes may be used as carriers of a slowly released drug. It is possible to use of electromagnetic waves to destroy cancer cells by the carbon nanotubes (CNTs). In our research we focused on thermal ablation by ferromagnetic carbon nanotubes (Fe-CNTs). In the cancer cell hyperthermia functionalized carbon nanotubes are exposed to radio frequency electromagnetic field. Properly functionalized Fe-CNTs join the cancer cells. Heat generated in nanoparticles connected to nanotubes warm up nanotubes and then the target tissue. When the temperature in tumor tissue exceeds 316 K the necrosis of cancer cells may be observed. Several techniques can be used for Fe-CNTs synthesis. In our work, we use high-temperature methods where arc-discharge is applied. Low-temperature systems are microwave plasma with assisted chemical vapor deposition (MPCVD) and hybrid physical-chemical vapor deposition (HPCVD). In the arc discharge system, the plasma reactor works with a pressure of He up to 0,5 atm. The electric arc burns between two graphite rods. Vapors of carbon move from the anode, through a short arc column and forms CNTs which can be collected either from the reactor walls or cathode deposit. This method is suitable for the production of multi-wall and single-wall CNTs. A disadvantage of high-temperature methods is a low purification, short length, random size and multi-directional distribution. In MPCVD system plasma is generated in waveguide connected to the microwave generator. Then containing carbon and ferromagnetic elements plasma flux go to the quartz tube. The additional resistance heating can be applied to increase the reaction effectiveness and efficiency. CNTs nucleation occurs on the quartz tube walls. It is also possible to use substrates to improve carbon nanotubes growth. HPCVD system involves both chemical decomposition of carbon containing gases and vaporization of a solid or liquid source of catalyst. In this system, a tube furnace is applied. A mixture of working and carbon-containing gases go through the quartz tube placed inside the furnace. As a catalyst ferrocene vapors can be used. Fe-CNTs may be collected then either from the quartz tube walls or on the substrates. Low-temperature methods are characterized by higher purity product. Moreover, carbon nanotubes from tested CVD systems were partially filled with the iron. Regardless of the method of Fe-CNTs synthesis the final product always needs to be purified for applications in medicine. The simplest method of purification is an oxidation of the amorphous carbon. Carbon nanotubes dedicated for cancer cell thermal ablation need to be additionally treated by acids for defects amplification on the CNTs surface what facilitates biofunctionalization. Application of ferromagnetic nanotubes for cancer treatment is a promising method of fighting with cancer for the next decade. Acknowledgment: The research work has been financed from the budget of science as a research project No. PBS2/A5/31/2013

Keywords: arc discharge, cancer, carbon nanotubes, CVD, thermal ablation

Procedia PDF Downloads 449

Authors: Jay N. Vyas, Sachin Daxini

Abstract:

Numerical simulation techniques are widely used now in product development and testing instead of expensive, time-consuming and sometimes dangerous laboratory experiments. Numerous numerical methods are available for performing simulation of physical problems of different engineering fields. Grid based methods, like Finite Element Method, are extensively used in performing various kinds of static, dynamic, structural and non-structural analysis during product development phase. Drawbacks of grid based methods in terms of discontinuous secondary field variable, dealing fracture mechanics and large deformation problems led to development of a relatively a new class of numerical simulation techniques in last few years, which are popular as Meshless methods or Meshfree Methods. Meshless Methods are expected to be more adaptive and flexible than Finite Element Method because domain descretization in Meshless Method requires only nodes. Present paper introduces Meshless Methods and differentiates it with Finite Element Method in terms of following aspects: Shape functions used, role of weight function, techniques to impose essential boundary conditions, integration techniques for discrete system equations, convergence rate, accuracy of solution and computational effort. Capabilities, benefits and limitations of Meshless Methods are discussed and concluded at the end of paper.

Keywords: numerical simulation, Grid-based methods, Finite Element Method, Meshless Methods

Procedia PDF Downloads 389

Authors: Rajeev jain, D. C. Tiwari, Praveena Mishra

Abstract:

Nano-composite of polypyrrole/multiwalled carbon nanotubes:mangenese oxide (PPy/MWCNT:MnO2) was electrochemically deposited on the surface of carbon cloth (CC). The nano-composite was structurally characterized by FTIR, SEM, TEM and UV-Vis studies. Nano-composite was also characterized by cyclic voltammetry (CV), current voltage measurements (I-V) and the optical band gaps of film were evaluated from UV-Vis absorption studies. The PPy/MWCNT:MnO2 nano-composite was used as anode in microbial fuel cell (MFC) for sewage waste water treatment, power and coulombic efficiency measurement. The prepared electrode showed good electrical conductivity (0.1185 S m-1). This was also supported by band gap measurements (direct 0.8 eV, indirect 1.3 eV). The obtained maximum power density was 1125.4 mW m-2, highest chemical oxygen demand (COD) removal efficiency was 93% and the maximum coulombic efficiency was 59%. For the first time PPy/MWCNT:MnO2 nano-composite for MFC prepared from nano-composite electrode having the potential for the use in MFC with good stability and better adhesion of microbes is being reported. The SEM images confirm the growth and development of microbe’s colony.

Keywords: carbon cloth, electro-polymerization, functionalization, microbial fuel cells, multi walled carbon nanotubes, polypyrrole

Procedia PDF Downloads 271

Authors: João Paulo Pascon

Abstract:

In this work, a mixed 3D finite element formulation is proposed in order to analyze thermoviscoplastic materials under large strain levels and ductile damage. To this end, a tetrahedral element of linear order is employed, considering a thermoviscoplastic constitutive law together with the neo-Hookean hyperelastic relationship and a nonlocal Gurson`s porous plasticity theory The material model is capable of reproducing finite deformations, elastoplastic behavior, void growth, nucleation and coalescence, thermal effects such as plastic work heating and conductivity, strain hardening and strain-rate dependence. The nonlocal character is introduced by means of a nonlocal parameter applied to the Laplacian of the porosity field. The element degrees of freedom are the nodal values of the deformed position, the temperature and the nonlocal porosity field. The internal variables are updated at the Gauss points according to the yield criterion and the evolution laws, including the yield stress of matrix, the equivalent plastic strain, the local porosity and the plastic components of the Cauchy-Green stretch tensor. Two problems involving 3D specimens and ductile damage are numerically analyzed with the developed computational code: the necking problem and a notched sample. The effect of the nonlocal parameter and the mesh refinement is investigated in detail. Results indicate the need of a proper nonlocal parameter. In addition, the numerical formulation can predict ductile fracture, based on the evolution of the fully damaged zone.

Keywords: mixed finite element, large strains, ductile damage, thermoviscoplasticity

Procedia PDF Downloads 95

Authors: T. Kuchukhidze, N. Jalagonia, T. Archuadze, G. Bokuchava

Abstract:

The growing scientific-technological progress in modern civilization causes actuality of producing construction materials which can successfully work in conditions of high temperature, radiation, pressure, speed, and chemically aggressive environment. Such extreme conditions can withstand very few types of materials and among them, ceramic materials are in the first place. Corundum ceramics is the most useful material for creation of constructive nodes and products of various purposes for its low cost, easy accessibility to raw materials and good combination of physical-chemical properties. However, ceramic composite materials have one disadvantage; they are less plastics and have lower toughness. In order to increase the plasticity, the ceramics are reinforced by various dopants, that reduces the growth of the cracks. It is shown, that adding of even small amount of carbon fibers and carbon nanotubes (CNT) as reinforcing material significantly improves mechanical properties of the products, keeping at the same time advantages of alundum ceramics. Graphene in composite material acts in the same way as inorganic dopants (MgO, ZrO2, SiC and others) and performs the role of aluminum oxide inhibitor, as it creates shell, that gives possibility to reduce sintering temperature and at the same time it acts as damper, because scattering of a shock wave takes place on carbon structures. Application of different structural modification of carbon (graphene, nanotube and others) as reinforced material, gives possibility to create multi-purpose highly requested composite materials based on alundum ceramics. In the present work offers simplified technology for obtaining of aluminum oxide ceramics, reinforced with carbon nanostructures, during which chemical modification with doping carbon nanostructures will be implemented in the process of synthesis of final powdery composite – Alumina. In charge doping carbon nanostructures connected to matrix substance with C-O-Al bonds, that provide their homogeneous spatial distribution. In ceramic obtained as a result of consolidation of such powders carbon fragments equally distributed in the entire matrix of aluminum oxide, that cause increase of bending strength and crack-resistance. The proposed way to prepare the charge simplifies the technological process, decreases energy consumption, synthesis duration and therefore requires less financial expenses. In the implementation of this work, modern instrumental methods were used: electronic and optical microscopy, X-ray structural and granulometric analysis, UV, IR, and Raman spectroscopy.

Keywords: ceramic materials, α-Al₂O₃, carbon nanostructures, composites, characterization, hot-pressing

Procedia PDF Downloads 119

Authors: Eric Ohene, Albert P. C. Chan, Shu-Chien HSU

Abstract:

The rising building energy consumption and related carbon emissions make it necessary to construct net-zero carbon buildings (NZCBs). The objective of net-zero buildings has raised the benchmark for building performance and will alter how buildings are designed and constructed. However, there have been growing concerns about uncertainty in net-zero building design and cost implications in decision-making. Lessons from practice have shown that a robust net-zero building design is complex, expensive, and time-consuming. Moreover, climate conditions have an enormous implication for choosing the best-optimal passive and active solutions to ensure building energy performance while ensuring the indoor comfort performance of occupants. It is observed that 20% of the design decisions made in the initial design phase influence 80% of all design decisions. To design and construct NZCBs, it is crucial to ensure adequate decision-making during the early design phases. Therefore, this study aims to explore practical strategies to design NZCBs and to offer a design framework that could help decision-making during the design stage of net-zero buildings. A parametric simulation approach was employed, and experts (i.e., architects, building designers) perspectives on the decision framework were solicited. The study could be helpful to building designers and architects to guide their decision-making during the design stage of NZCBs.

Keywords: net-zero, net-zero carbon building, energy efficiency, parametric simulation, hot climate

Procedia PDF Downloads 105

Authors: Ebru Kaymaz, Aslı İlbay Hamamcı, Yakup Enes Garip, Samet Ay

Abstract:

The use of hydrogen as a fuel is important for decreasing carbon emissions. For the steel industry, reducing carbon emissions is one of the most important agendas of recent times globally. Because of the Paris Agreement requirements, European steel industry studies on green steel production. Although many literature reviews have analyzed this topic from technological and hydrogen based ironmaking, there are very few studies focused on patents of decarbonize parts of the steel industry. Hence, this study focus on technological progress of hydrogen based ironmaking and on understanding the main trends through patent data. All available patent data were collected from Questel Orbit. The trend analysis of more than 900 patent documents has been carried out by using Questel Orbit Intellixir to analyze a large number of data for scientific intelligence.

Keywords: hydrogen based ironmaking, DRI, direct reduction, carbon emission, steelmaking, patent analysis

Procedia PDF Downloads 144

Authors: T. Mohanarajah, J. Rizk, M. Nagrial, A. Hellany

Abstract:

This paper analyses numerous features of the synchronous Reluctance Motor (Syn-RM) and propose a rotor for high electrical torque, power factor & efficiency using Finite Element Method (FEM). A comprehensive analysis completed on solid rotor structure while the total thickness of the flux guide kept constant. A number of tests carried out for nine different studies to find out optimum location of the flux guide, the optimum location of multiple flux guides & optimum wall thickness between flux guides for high-performance reluctance machines. The results are concluded with the aid of FEM simulation results, the saliency ratio and machine characteristics (location, a number of barriers & wall width) analysed.

Keywords: electrical machines, finite element method, synchronous reluctance machines, variable reluctance machines

Procedia PDF Downloads 485

Authors: Theo H. G. Moundzounga

Abstract:

Arsenic and 2-chlorophenol are priority pollutants that pose serious health threats to humans and ecology. An electrochemical sensor, based on graphitic carbon nitride (g-C₃N₄) and carbon dots (CDs), was fabricated and used for the determination of arsenic and 2-chlorophenol. The g-C₃N₄/CDs nanocomposite was prepared via microwave irradiation heating method and was dropped-dried on the surface of the glassy carbon electrode (GCE). Transmission electron microscopy (TEM), X-ray diffraction (XRD), photoluminescence (PL), Fourier transform infrared spectroscopy (FTIR), UV-Vis diffuse reflectance spectroscopy (UV-Vis DRS) were used for the characterization of structure and morphology of the nanocomposite. Electrochemical characterization was done by electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV). The electrochemical behaviors of arsenic and 2-chlorophenol on different electrodes (GCE, CDs/GCE, and g-C₃N₄/CDs/GCE) was investigated by differential pulse voltammetry (DPV). The results demonstrated that the g-C₃N₄/CDs/GCE significantly enhanced the oxidation peak current of both analytes. The analytes detection sensitivity was greatly improved, suggesting that this new modified electrode has great potential in the determination of trace level of arsenic and 2-chlorophenol. Experimental conditions which affect the electrochemical response of arsenic and 2-chlorophenol were studied, the oxidation peak currents displayed a good linear relationship to concentration for 2-chlorophenol (R²=0.948, n=5) and arsenic (R²=0.9524, n=5), with a linear range from 0.5 to 2.5μM for 2-CP and arsenic and a detection limit of 2.15μM and 0.39μM respectively. The modified electrode was used to determine arsenic and 2-chlorophenol in spiked tap and effluent water samples by the standard addition method, and the results were satisfying. According to the measurement, the new modified electrode is a good alternative as chemical sensor for determination of other phenols.

Keywords: electrochemistry, electrode, limit of detection, sensor

Procedia PDF Downloads 144

Authors: V. D. Thi, M. Li, M. Khelifa, M. El Ganaoui, Y. Rogaume

Abstract:

This paper presents a two-dimensional model to study the heat and moisture transfer through porous building materials. Dynamic and static coupled models of heat and moisture transfer in porous material under low temperature are presented and the coupled models together with variable initial and boundary conditions have been considered in an analytical way and using the finite element method. The resulting coupled model is converted to two nonlinear partial differential equations, which is then numerically solved by an implicit iterative scheme. The numerical results of temperature and moisture potential changes are compared with the experimental measurements available in the literature. Predicted results demonstrate validation of the theoretical model and effectiveness of the developed numerical algorithms. It is expected to provide useful information for the porous building material design based on heat and moisture transfer model.

Keywords: finite element method, heat transfer, moisture transfer, porous materials, wood

Procedia PDF Downloads 400

Authors: S. A. Tabatabaei, S. Aarabi

Abstract:

Predicting the hot mix asphalt (HMA) response and performance is a challenging task because of the subjectivity of HMA under the complex loading and environmental condition. The behavior of HMA is a function of temperature of loading and also shows the time and rate-dependent behavior directly affecting design criteria of mixture. Velocity of load passing make the time and rate. The viscoelasticity illustrates the reaction of HMA under loading and environmental conditions such as temperature and moisture effect. The behavior has direct effect on design criteria such as tensional strain and vertical deflection. In this paper, the computational framework for viscoelasticity and implementation in 3D dimensional HMA model is introduced to use in finite element method. The model was lied under various repeated loading conditions at constant temperature. The response of HMA viscoelastic behavior is investigated in loading condition under speed vehicle and sensitivity of behavior to the range of speed and compared to HMA which is supposed to have elastic behavior as in conventional design methods. The results show the importance of loading time pulse, unloading time and various speeds on design criteria. Also the importance of memory fading of material to storing the strain and stress due to repeated loading was shown. The model was simulated by ABAQUS finite element package

Keywords: viscoelasticity, finite element method, repeated loading, HMA

Procedia PDF Downloads 398

Authors: Usman D. Hamza, Noor S. Nasri, Mohammed Jibril, Husna M. Zain

Abstract:

Activated carbons (M4P0, M4P2, and M5P2) used in this research were produced from palm shell and polyetherether ketone (PEEK) via carbonization, impregnation, and microwave activation. The adsorption/desorption process was carried out using static volumetric adsorption. Regeneration is important in the overall economy of the process and waste minimization. This work focuses on the thermal regeneration of the CO2 exhausted microwave activated carbons. The regeneration strategy adopted was thermal with nitrogen purge desorption with N2 feed flow rate of 20 ml/min for 1 h at atmospheric pressure followed by drying at 1500C. Seven successive adsorption/regeneration processes were carried out on the material. It was found that after seven adsorption regeneration cycles; the regeneration efficiency (RE) for CO2 activated carbon from palm shell only (M4P0) was more than 90% while that of hybrid palm shell-PEEK (M4P2, M5P2) was above 95%. The cyclic adsorption and regeneration shows the stability of the adsorbent materials.

Keywords: activated carbon, palm shell-PEEK, regeneration, thermal

Procedia PDF Downloads 488

Authors: Simon Bard, Martin Demleitner, Florian Schonl, Volker Altstadt

Abstract:

For an electrically driven aircraft, whose engine is based on semiconductors, alternative materials are needed. The avoid hotspots in the materials thermally conductive polymers are necessary. Nevertheless, the mechanical properties of these materials should remain. Herein, the work of three years in a project with airbus and Siemens is presented. Different strategies have been pursued to achieve conductive fiber-reinforced composites: Metal-coated carbon fibers, pitch-based fibers and particle-loaded matrices have been investigated. In addition, a combination of copper-coated fibers and a conductive matrix has been successfully tested for its conductivity and mechanical properties. First, prepregs have been produced with a laboratory scale prepreg line, which can handle materials with maximum width of 300 mm. These materials have then been processed to fiber-reinforced laminates. For the PAN-fiber reinforced laminates, it could be shown that there is a strong dependency between fiber volume content and thermal conductivity. Laminates with 50 vol% of carbon fiber offer a conductivity of 0.6 W/mK, those with 66 vol% of fiber a thermal conductivity of 1 W/mK. With pitch-based fiber, the conductivity enhances to 1.5 W/mK for 61 vol% of fiber, compared to 0.81 W/mK with the same amount of fibers produced from PAN (+83% in conducitivity). The thermal conductivity of PAN-based composites with 50 vol% of fiber is at 0.6 W/mK, their nickel-coated counterparts with the same fiber volume content offer a conductivity of 1 W/mK, an increase of 66%.

Keywords: carbon, electric aircraft, polymer, thermal conductivity

Procedia PDF Downloads 163

Authors: Ebrahim Akbarzadeh, Josep A. Picas Barrachina, Maite Baile Puig

Abstract:

This study focuses on a novel method for dispersion and distribution of reinforcement under high intensive shear stress to produce metal composites. The polyacrylonitrile (PAN)-based short carbon fiber (Csf) and Nextel 610 alumina fiber were dispersed under high intensive shearing at mushy zone in semi-solid of A356 by a novel method. The bundles and clusters were embedded by infiltration of slurry into the clusters, thus leading to a uniform microstructure. The fibers were embedded homogenously into the aluminum around 576-580°C with around 46% of solid fraction. Other experiments at 615°C and 568°C which are contained 0% and 90% solid respectively were not successful for dispersion and infiltration of aluminum into bundles of Csf. The alumina fiber has been cracked by high shearing load. The morphologies and crystalline phase were evaluated by SEM and XRD. The adopted thixo-process effectively improved the adherence and distribution of Csf into Al that can be developed to produce various composites by thixomixing.

Keywords: aluminum, carbon fiber, alumina fiber, thixomixing, adhesion

Procedia PDF Downloads 557

Authors: Z. N. Ali, O. A. Babatunde, S. Garba, H. M. S. Haruna

Abstract:

The potency of modified and unmodified activated carbons prepared from shells of Cocos nucifera (coconut shell), straws of Pennisetum glaucum (millet) and Sorghum bicolor (sorghum) for adsorption of hydrogen sulphide gas were investigated using an adsorption apparatus (stainless steel cylinder) at constant temperature (ambient temperature). The adsorption equilibria states were obtained when the pressure indicated on the pressure gauge remained constant. After modification with nitric acid, results of the scanning electron microscopy of the unmodified and modified activated carbons showed that HNO3 greatly improved the formation of micropores and mesopores on the activated carbon surface. The adsorption of H2S gas was found to be highest in modified Cocos nucifera activated carbon with maximum monolayer coverage of 28.17 mg/g, and the adsorption processes were both physical and chemical with the physical process being predominant. The adsorption data were well fitted into the Langmuir isotherm model with the adsorption capacities of the activated carbons in the order modified Cocos nucifera > modified Pennisetum glaucum > modified Sorghum bicolor > unmodified Cocos nucifera > unmodified Pennisetum glaucum > unmodified Sorghum bicolour.

Keywords: activated carbon adsorption, hydrogen sulphide, nitric acid, modification, stainless steel cylinder

Procedia PDF Downloads 138

Authors: Shagil Akhtar, Syed Muneeb Iqbal, Mohammed R. Rahim

Abstract:

Common steel tubes with similar confines were used in simulation of tubes with distinctive type of corrugated sections. These corrugated cross-sections were arc-tangent, triangular, trapezoidal and square corrugated sections. The outcome of fluctuating structures of tube cross-section shape on the deformation feedback, collapse form and energy absorption characteristics of tubes under quasi-static axial compression have been prepared numerically. The finite element package of ANSYS Workbench was applied in the current analysis. The axial load-displacement products accompanied by the fold formation of disparate tubes were inspected and compared. Deviation of the initial peak load and the mean crushing force of the tubes with distinctive cross-sections were conscientiously examined.

Keywords: absorbed energy, axial loading, corrugated tubes, finite element, initial peak load, mean crushing force

Procedia PDF Downloads 388

Authors: Deepak Kumar Mittal, Alok Kumar Jena, Deepmala Joshi

Abstract:

The present study was carried out to observe the hepatoprotective effect and antioxidant activity of the aqueous extract of the roots of Polygonum bistorta (PB) (200 mg/kg) and Zingiber roseum (ZR) (250 mg/kg) in rats treated with carbon tetrachloride (0.15 ml/kg, i.p.). Extract of PB and ZR at the tested doses restored the levels of liver homogenate enzymes, glutathione peroxidase, glutathione-S-transferase, superoxide dismutase and catalase enzymes, significantly. The activities of MTT assay significantly recovered the damage and supported the biochemical observations. This study suggests that Zingiber roseum has a higher protective effect on liver, compared to Polygonum bistorta, against carbon tetrachloride-induced hepatotoxicity and possesses antioxidant activities. Also, extracts exhibited moderate anticancer activity towards cell viability at higher concentration.

Keywords: Polygonum bistorta, Zingiber roseum, hepatoprotective effect, carbon tetrachloride, anti-cancerous

Procedia PDF Downloads 430

Authors: Yongde Xia, Laicong Deng, Zhuxian Yang

Abstract:

Developing cost-effective electrocatalysts for oxygen reduction reaction (ORR), oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) is vital in energy conversion and storage applications. Herein, we report a simple method for the synthesis of graphene-reinforced cobalt sulfide/carbon nanocomposites and the evaluation of their electrocatalytic performance for typical electrocatalytic reactions. Nanocomposites of cobalt sulfide embedded in N, S co-doped porous carbon and graphene (CoS@C/Graphene) were generated via simultaneous sulfurization and carbonization of one-pot synthesized graphite oxide-ZIF-67 precursors. The obtained CoS@C/Graphene nanocomposite was characterized by X-ray diffraction, Raman spectroscopy, Thermogravimetric analysis-Mass spectroscopy, Scanning electronic microscopy, Transmission electronic microscopy, X-ray photoelectron spectroscopy and gas sorption. It was found that cobalt sulfide nanoparticles were homogenously dispersed in the in-situ formed N, S co-doped porous carbon/Graphene matrix. The CoS@C/10Graphene composite not only shows excellent electrocatalytic activity toward ORR with high onset potential of 0.89 V, four-electron pathway and superior durability of maintaining 98% current after continuously running for around 5 hours, but also exhibits good performance for OER and HER, due to the improved electrical conductivity, increased catalytic active sites and connectivity between the electrocatalytic active cobalt sulfide and the carbon matrix. This work offers a new approach for the development of novel multifunctional nanocomposites for the next generation of energy conversion and storage applications.

Keywords: MOF derivative, graphene, electrocatalyst, oxygen reduction reaction, oxygen evolution reaction, hydrogen evolution reaction

Procedia PDF Downloads 50

Authors: Anup Kumar Keshri, Arvind Agarwal

Abstract:

Carbon nanotube (CNT) reinforced aluminum oxide (Al2O3) composite coating was synthesized on the steel substrate using plasma spraying technique. Three different compositions of coating such as Al2O3, Al2O¬3-4 wt. % CNT and Al2O3-8 wt. % CNT were synthesized and the fracture strength was determined using the four point bend test. Uniform dispersion of CNTs over Al2O3 powder particle was successfully achieved. With increasing CNT content, porosity in the coating showed decreasing trend and hence contributed towards enhanced mechanical properties such as hardness (~12% increased) and elastic modulus (~34 % increased). Fracture strength of the coating was found to be increasing with the CNT additions. By reinforcement of 8 wt. % of CNT, fracture strength increased by ~2.5 times. The improvement in fracture strength of Al2O3-CNT coating was attributed to three competitive phenomena viz. (i) lower porosity (ii) higher hardness and elastic modulus (iii) CNT bridging between splats.

Keywords: aluminum oxide, carbon nanotube, fracture strength, plasma spraying

Procedia PDF Downloads 394

Authors: Alia Alghosoun, Ashraf Osman, Mohammed Seaid

Abstract:

A coupled two-layer finite volume/finite element method was proposed for solving dam-break flow problem over deformable beds. The governing equations consist of the well-balanced two-layer shallow water equations for the water flow and a linear elastic model for the bed deformations. Deformations in the topography can be caused by a brutal localized force or simply by a class of sliding displacements on the bathymetry. This deformation in the bed is a source of perturbations, on the water surface generating water waves which propagate with different amplitudes and frequencies. Coupling conditions at the interface are also investigated in the current study and two mesh procedure is proposed for the transfer of information through the interface. In the present work a new procedure is implemented at the soil-water interface using the finite element and two-layer finite volume meshes with a conservative distribution of the forces at their intersections. The finite element method employs quadratic elements in an unstructured triangular mesh and the finite volume method uses the Rusanove to reconstruct the numerical fluxes. The numerical coupled method is highly efficient, accurate, well balanced, and it can handle complex geometries as well as rapidly varying flows. Numerical results are presented for several test examples of dam-break flows over deformable beds. Mesh convergence study is performed for both methods, the overall model provides new insight into the problems at minimal computational cost.

Keywords: dam-break flows, deformable beds, finite element method, finite volume method, hybrid techniques, linear elasticity, shallow water equations

Procedia PDF Downloads 181

Authors: Hassan Noun, Christian Urban-Seelmann, Mohamed Abdelfattah, Guillaume Zeller, Rajesh G., Iryna Mozgova, Roland Lachmayer

Abstract:

Several modules in automotive are usually modified and adapted for various project-specific applications. Due to a standardized safety concept, high reusability is accessible. A safety element out of context (SEooC) according to ISO 26262 can be a suitable approach. Based on the same safety concept and analysis, common modules can reach high usability. For developing according to a module out of context, an appropriate and detailed development approach is required. This paper shows how to derive these development processes for platform modules. Therefore, the detailed approach to the safety element out of context is derived. The aim is to create a detailed workflow for all phases of the development and integration of any kind of system modules. As an application example, an automotive project for an actuator control module is considered.

Keywords: functional safety, engineering processes, system engineering, electronic engineering

Procedia PDF Downloads 144

Authors: Chedly Tizaoui, Hussain Mohammed, Lobna Mansouri, Nidal Hilal, Latifa Bousselmi

Abstract:

The degradation of diethyl phthalate (DEP) was studied using heterogeneous catalytic ozonation. Activated carbon was used as a catalyst. The degradation of DEP with ozone alone was slow while catalytic ozonation increased degradation rates. Second-order reaction kinetics was used to describe the experimental data, and the corresponding rate constant values were 1.19 and 3.94 M-1.s-1 for ozone and ozone/activated carbon respectively.

Keywords: ozone, heterogeneous catalytic ozonation, diethyl phthalate, endocrine disrupting chemicals

Procedia PDF Downloads 347

Authors: Elisa Y. M. Ang, Teng Yong Ng, Jingjie Yeo, Rongming Lin, Zishun Liu, K. R. Geethalakshmi

Abstract:

By stacking carbon nanotubes (CNT) one on top of another, single layer CNT arrays can perform water-salt separation with ultra-high permeability and selectivity. Such outer-wall CNT slit membrane is named as the transverse flow CNT membrane. By adjusting the slit size between neighboring CNTs, the membrane can be configured to sieve out different solutes, right down to the separation of monovalent salt ions from water. Molecular dynamics (MD) simulation results show that the permeability of transverse flow CNT membrane is more than two times that of conventional axial-flow CNT membranes, and orders of magnitude higher than current reverse osmosis membrane. In addition, by carrying out MD simulations with different CNT size, it was observed that the variance in desalination performance with CNT size is small. This insensitivity of the transverse flow CNT membrane’s performance to CNT size is a distinct advantage over axial flow CNT membrane designs. Not only does the membrane operate well under constant pressure desalination operation, but MD simulations further indicate that oscillatory operation can further enhance the membrane’s desalination performance, making it suitable for operation such as electrodialysis reversal. While there are still challenges that need to be overcome, particularly on the physical fabrication of such membrane, it is hope that this versatile membrane design can bring the idea of using low dimensional structures for desalination closer to reality.

Keywords: carbon nanotubes, membrane desalination, transverse flow carbon nanotube membrane, molecular dynamics

Procedia PDF Downloads 196

Authors: M. Mohan, J. P. Roise, G. P. Catts

Abstract:

Despite living in an era where conservation zones are de-facto the central element in any sustainable wildlife management strategy, we still find ourselves grappling with several pareto-optimal situations regarding resource allocation and area distribution for the same. In this paper, a multi-objective decision making (MODM) model is presented to answer the question of whether or not we can establish mutual relationships between these contradicting objectives. For our study, we considered a Red-cockaded woodpecker (Picoides borealis) habitat conservation scenario in the coastal plain of North Carolina, USA. Red-cockaded woodpecker (RCW) is a non-migratory territorial bird that excavates cavities in living pine trees for roosting and nesting. The RCW groups nest in an aggregation of cavity trees called ‘cluster’ and for our model we use the number of clusters to be established as a measure of evaluating the size of conservation zone required. The case study is formulated as a linear programming problem and the objective function optimises the Red-cockaded woodpecker clusters, carbon retention rate, biofuel, public safety and Net Present Value (NPV) of the forest. We studied the variation of individual objectives with respect to the amount of area available and plotted a two dimensional dynamic graph after establishing interrelations between the objectives. We further explore the concept of interdependency by integrating the MODM model with GIS, and derive a raster file representing carbon distribution from the existing forest dataset. Model results demonstrate the applicability of interdependency from both linear and spatial perspectives, and suggest that this approach holds immense potential for enhancing environmental investment decision making in future.

Keywords: conservation, interdependency, multi-objective decision making, red-cockaded woodpecker

Procedia PDF Downloads 337

Authors: Sudipt Agarwal, Siddharth Verma, S. M. Iqbal, Hitik Kalra

Abstract:

Natural gas as a fuel has created wonders, but on the contrary, the ill-effects of methane have been a great worry for professionals. The largest source of methane emission is the oil and gas industry among all industries. Methane depletes groundwater and being a greenhouse gas has devastating effects on the atmosphere too. Methane remains for a decade or two in the atmosphere and later breaks into carbon dioxide and thus damages it immensely, as it warms up the atmosphere 72 times more than carbon dioxide in those two decades and keeps on harming after breaking into carbon dioxide afterward. The property of a fluid to adhere to the surface of a solid, better known as adsorption, can be a great boon to minimize the hindrance caused by methane. Adsorption of methane during upstream processes can save the groundwater and atmospheric depletion around the site which can be hugely lucrative to earn profits which are reduced due to environmental degradation leading to project cancellation. The paper would deal with reasons why casing and cementing are not able to prevent leakage and would suggest methods to adsorb methane during upstream processes with mathematical explanation using volumetric analysis of adsorption of methane on the surface of activated carbon doped with copper oxides (which increases the absorption by 54%). The paper would explain in detail (through a cost estimation) how the proposed idea can be hugely beneficial not only to environment but also to the profits earned.

Keywords: adsorption, casing, cementing, cost estimation, volumetric analysis

Procedia PDF Downloads 191

Authors: Lim Sanny, Felix Christian

Abstract:

The use of heavy equipment in Indonesia is always increasing. Cost reduction in procurement of spare parts is the aim of the company. The spare parts in this research are focused in the kind of filters. On the early step, the choosing of priority filter will be studied further by using the ABC analysis. To find out future demand of the filter, this research is using demand forecast by utilizing the QM software for windows. And to find out the best method of inventory control for each kind of filter is by comparing the total cost of Economic Order Quantity and Quick response inventory method. For the three kind of filters which are Cartridge, Engine oil – pn : 600-211-123, Element, Transmission – pn : 424-16-11140, and Element, Hydraulic – pn : 07063-01054, the best forecasting method is Linear regression. The best method for inventory control of Cartridge, Engine oil – pn : 600-211-123 and Element, Transmission – pn : 424-16-11140, is Quick Response Inventory, while the best method for Element, Hydraulic – pn : 07063-01054 is Economic Order Quantity.

Keywords: strategy, inventory, ABC analysis, forecasting, economic order quantity, quick response inventory

Procedia PDF Downloads 364