Search results for: AP/HTPB composite solid propellant
422 Production of (V-B) Reinforced Fe Matrix Composites
Authors: Kerim Emre Öksüz, Mehmet Çevik, A. Enbiya Bozdağ, Ali Özer, Mehmet Simsir
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Metal matrix composites (MMCs) have gained a considerable interest in the last three decades. Conventional powder metallurgy production route often involves the addition of reinforcing phases into the metal matrix directly, which leads to poor wetting behavior between ceramic phase and metal matrix and the segregation of reinforcements. The commonly used elements for ceramic phase formation in iron based MMCs are Ti, Nb, Mo, W, V and C, B. The aim of the present paper is to investigate the effect of sintering temperature and V-B addition on densification, phase development, microstructure, and hardness of Fe–V-B composites (Fe-(5-10) wt. %B – 25 wt. %V alloys) prepared by powder metallurgy process. Metal powder mixes were pressed uniaxial and sintered at different temperatures (ranging from 1300 to 1400ºC) for 1h. The microstructure of the (V, B) Fe composites was studied with the help of high magnification optical microscope and XRD. Experimental results show that (V, B) Fe composites can be produced by conventional powder metallurgy route.
Keywords: Hardness, Metal matrix composite (MMC), Microstructure, Powder Metallurgy.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2762421 Comparison of Vermicompost and Vermiwash Bio-Fertilizers from Vermicomposting Waste Corn Pulp
Authors: M. M. Manyuchi, A. Phiri, P. Muredzi, T. Chitambwe
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Vermicomposting is the conversion of organic waste into bio-fertilizers through the action of earthworm. This technology is widely used for organic solid waste management. Waste corn pulp blended with cow dung manure was vermicomposted over 30 days using Eisenia fetida earthworms species. pH, temperature, moisture content, and electrical conductivity were daily monitored. The feedstock, vermicompost and vermiwash were analyzed for nutrient composition. The average temperature and moisture content in the vermi-reactor was 22.5°C and 42.5% respectively. The vermicompost and vermiwash had an almost neutral pH whilst the electrical conductivity was 21% higher in the vermicompost. The nitrogen and potassium content was 57% and 79.6% richer in the vermicompost respectively compared to the vermiwash. However, the vermiwash was 84% richer in phosphorous as compared to vermicompost. Furthermore, the vermiwash was 89.1% and 97.6% richer in Ca and Mg respectively and was 97.8% richer in Na salts compared to the vermicompost. The vermiwash also indicated a significantly higher amount of micronutrients. Both bio-fertilizers were rich in nutrients specification for fertilizers.Keywords: Vermicompost, vermiwash, nutrient composition.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 6795420 Parametric Studies of Wood Pyrolysis Particles
Authors: W. Afef, A. Mohamed Ammar, G. Kamel, O. Ahmed
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In the present study, a numerical approach to describe the pyrolysis of a single solid particle of wood is used to study the influence of various conditions such as particle size, heat transfer coefficient, reactor temperature and heating rate. The influence of these parameters in the change of the duration of the pyrolysis cycle was studied. Mathematical modeling was employed to simulate the heat, mass transfer, and kinetic processes inside the reactor. The evolutions of the mass loss as well as the evolution of temperature inside the thick piece are investigated numerically. The elaborated model was also employed to study the effect of the reactor temperature and the rate of heating on the change of the temperature and the local loss of the mass inside the piece of wood. The obtained results are in good agreement with the experimental data available in the literature.
Keywords: Wood, Pyrolysis, Modeling, Convective heat transfer, Kinetic.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1376419 Treatment of Chrome Tannery Wastewater by Biological Process - A Mini Review
Authors: Supriyo Goswami, Debabrata Mazumder
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Chrome tannery wastewater causes serious environmental hazard due to its high pollution potential. As a result, rigorous treatment is necessary for abatement of pollution from this type of wastewater. There are many research studies on chrome tannery wastewater treatment in the field of physical, chemical, and biological methods. In general, biological treatment process is found ineffective for direct application because of adverse effects by toxic chromium, sulphide, chloride etc. However, biological methods were employed mainly for a few sub processes generating significant amount of organic matter and without chromium, chlorides etc. In this context the present paper reviews the characteristics feature and pollution potential of wastewater generated from chrome tannery units and treatment of the same. The different biological processes used earlier and their chronological development for treatment of the chrome tannery wastewater are thoroughly reviewed in this paper. In this regard, the scope of hybrid bioreactor - an advanced technology option has also been explored, as this kind of treatment is well suited for the wastewater having inhibitory substances.
Keywords: Composite tannery wastewater, biological treatment, Hybrid bioreactor, Organic removal
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 4226418 A Global Perspective on Urban Environmental Problems in Developing Countries: The Case of Turkey
Authors: Nükhet Konuk, N. Gamze Turan, Yüksel Ardalı
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Cities play a vital role in the social fabric of countries and in national and regional economic growth worldwide; however, the environmental effects of such growth need to be assessed and managed better. The critical and most immediate problems faced by cities of developing countries are the health impacts of urban pollution that derive from inadequate water, sanitation, drainage and solid waste services, poor urban and industrial waste management, and air pollution. As globalization continues, earth's natural processes transform local problems into international issues. The aim of this study is to provide a broad overview of the pollution from urban wastes and emissions in Turkey which is a developing country. It is aimed to underline the significance of reorganizing the institutional tools in a worldwide perspective in order to generate coherent solutions to urban problems, and to enhance urban quality.Keywords: Environmental pollution, developing countries, environmental degradation, urban environmental problems.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2220417 The Effect of Material Properties and Volumetric Changes in Phase Transformation to the Final Residual Stress of Welding Process
Authors: Djarot B. Darmadi
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The wider growing Finite Element Method (FEM) application is caused by its benefits of cost saving and environment friendly. Also, by using FEM a deep understanding of certain phenomenon can be achieved. This paper observed the role of material properties and volumetric change when Solid State Phase Transformation (SSPT) takes place in residual stress formation due to a welding process of ferritic steels through coupled Thermo- Metallurgy-Mechanical (TMM) analysis. The correctness of FEM residual stress prediction was validated by experiment. From parametric study of the FEM model, it can be concluded that the material properties change tend to over-predicts residual stress in the weld center whilst volumetric change tend to underestimates it. The best final result is the compromise of both by incorporates them in the model which has a better result compared to a model without SSPT.Keywords: Residual stress, ferritic steels, SSPT, coupled-TMM.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1983416 Influence of S. carnosus Bacteria as Biocollector for the Recovery Organic Matter in the Flotation Process
Authors: G. T. Ramos-Escobedo, E. T. Pecina-Treviño, L. F. Camacho-Ortegon, E. Orrantia-Borunda
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The mineral bioflotation represents a viable alternative for the evaluation of new processes benefit alternative. The adsorption bacteria on minerals surfaces will depend mainly on the type of the microorganism as well as of the studied mineral surface. In the current study, adhesion of S. carnosus on coal was studied. Several methods were used as: DRX, Fourier Transform Infra-Red (FTIR) adhesion isotherms and kinetic. The main goal is to recovery of organic matter by the microflotation process on coal particles with biological reagent (S. carnosus). Adhesion tests revealed that adhesion took place after of 8 h at pH 9. The results suggest that the adhesion of bacteria to solid substrates can be considered an abiotic physicochemical process that is consequently governed by bacterial surface properties such as their specific surface area, hydrophobicity and surface functionalities. The greatest coal fine flotability was of 75%, after 5 min of flotation.
Keywords: Fine Coal, Bacteria, Adhesion, recovery matter organic.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2087415 Evaluation for Punching Shear Strength of Slab-Column Connections with Ultra High Performance Fiber-Reinforced Concrete Overlay
Authors: H. S. Youm, S. G. Hong
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This paper presents the test results on 5 slab-column connection specimens with Ultra High Performance Fiber-Reinforced Concrete (UHPFRC) overlay including 1 control specimen to investigate retrofitting effect of UHPFRC overlay on the punching shear capacity. The test parameters were the thickness of the UHPFRC overlay and the amount of steel re-bars in it. All specimens failed in punching shear mode with abrupt failure aspect. The test results showed that by adding a thin layer of UHPFRC over the Reinforced Concrete (RC) substrates, considerable increases in global punching shear resistance up to 82% and structural rigidity were achieved. Furthermore, based on the cracking patterns the composite systems appeared to be governed by two failure modes: 1) diagonal shear failure in RC section and 2) debonding failure at the interface.
Keywords: Punching shear strength, retrofit, slab-column connection, UHPFRC, UHPFRC overlay.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1027414 Radiological Risk Assessment in Soil Samples of Western Haryana, India
Authors: R. Mehra
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The measurements of 226Ra, 232Th and 40K using gamma spectrometry and radon concentration and exhalation rates measurements using solid state nuclear track (LR-115, Type-II plastic) detectors are used to asses a first order exposure risk for the persons residing in Fatehbad and Hissar districts of Western Haryana, India. The concentration of Radium, Thorium and Potassium in the soil samples varies from 13.37 Bq m-3 to 24.67 Bq m-3, 34.67 Bq m-3 to 67.34 Bq m-3 and 298.78 Bq m-3 to 405.67 Bq m-3 respectively with average values of 18.78, 47.35 and 361.57 Bq m-3 respectively. The radium equivalent activity (Raeq) calculated for the same soil samples varies from 92.72 Bq m-3 to 140.6 Bq m-3 with an average value of 111.80 Bq m-3. The values of absorbed dose and annual effective dose (indoors and outdoors) are found to vary from 44.18 nGy h-1 to 65.23 nGy h-1, 0.22 mSv y-1 to 0.32 mSv y-1 and 0.05 mSv y-1 to 0.08 mSv y-1 respectively. The radon concentration and exhalation rates have also been reported. The radium equivalent activities in all the soil samples were found to be lower than the limit (370 Bq kg-1) set in the Organization for Economic Cooperation and Development (OECD) report and the value of Hex in all the samples is less than unity.Keywords: Gamma ray spectrometry, dose, radon, exhalationrate.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1838413 Influence of the Entropic Parameter on the Flow Geometry and Morphology
Authors: D. Mirauda, M. Greco, A. Volpe Plantamura
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The necessity of updating the numerical models inputs, because of geometrical and resistive variations in rivers subject to solid transport phenomena, requires detailed control and monitoring activities. The human employment and financial resources of these activities moves the research towards the development of expeditive methodologies, able to evaluate the outflows through the measurement of more easily acquirable sizes. Recent studies highlighted the dependence of the entropic parameter on the kinematical and geometrical flow conditions. They showed a meaningful variability according to the section shape, dimension and slope. Such dependences, even if not yet well defined, could reduce the difficulties during the field activities, and also the data elaboration time. On the basis of such evidences, the relationships between the entropic parameter and the geometrical and resistive sizes, obtained through a large and detailed laboratory experience on steady free surface flows in conditions of macro and intermediate homogeneous roughness, are analyzed and discussed.
Keywords: Froude number, entropic parameter, roughness, water discharge.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1318412 Adsorption of Acetone Vapors by SBA-16 and MCM-48 Synthesized from Rice Husk Ash
Authors: Wanting Zeng, Hsunling Bai
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Silica was extracted from agriculture waste rice husk ash (RHA) and was used as the silica source for synthesis of RMCM-48 and RSBA-16. An alkali fusion process was utilized to separate silicate supernatant and the sediment effectively. The CTAB/Si and F127/Si molar ratio was employed to control the structure properties of the obtained RMCM-48 and RSBA-16 materials. The N2 adsorption-desorption results showed the micro-mesoporous RSBA-16 possessed high specific surface areas (662-1001 m2/g). All the obtained RSBA-16 materials were applied as the adsorbents for acetone adsorption. And the breakthrough tests clearly revealed that the RSBA-16(0.004) materials could achieve the highest acetone adsorption capacity of 181 mg/g under 1000 ppmv acetone vapor concentration at 25oC, which was also superior to ZSM-5 (71mg/g) and MCM-41 (157mg/g) under same test conditions. This can help to reduce the solid waste and the high adsorption performance of the obtained materials could consider as potential adsorbents for acetone adsorption.
Keywords: Acetone, adsorption, micro-mesoporous material, rice husk ash (RHA), RSBA-16.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2083411 Development of Predictive Model for Surface Roughness in End Milling of Al-SiCp Metal Matrix Composites using Fuzzy Logic
Authors: M. Chandrasekaran, D. Devarasiddappa
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Metal matrix composites have been increasingly used as materials for components in automotive and aerospace industries because of their improved properties compared with non-reinforced alloys. During machining the selection of appropriate machining parameters to produce job for desired surface roughness is of great concern considering the economy of manufacturing process. In this study, a surface roughness prediction model using fuzzy logic is developed for end milling of Al-SiCp metal matrix composite component using carbide end mill cutter. The surface roughness is modeled as a function of spindle speed (N), feed rate (f), depth of cut (d) and the SiCp percentage (S). The predicted values surface roughness is compared with experimental result. The model predicts average percentage error as 4.56% and mean square error as 0.0729. It is observed that surface roughness is most influenced by feed rate, spindle speed and SiC percentage. Depth of cut has least influence.Keywords: End milling, fuzzy logic, metal matrix composites, surface roughness
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2174410 Homotopy Analysis Method for Hydromagnetic Plane and Axisymmetric Stagnation-point Flow with Velocity Slip
Authors: Jing Zhu, Liancun Zheng, Xinxin Zhang
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This work is focused on the steady boundary layer flow near the forward stagnation point of plane and axisymmetric bodies towards a stretching sheet. The no slip condition on the solid boundary is replaced by the partial slip condition. The analytical solutions for the velocity distributions are obtained for the various values of the ratio of free stream velocity and stretching velocity, slip parameter, the suction and injection velocity parameter, magnetic parameter and dimensionality index parameter in the series forms with the help of homotopy analysis method (HAM). Convergence of the series is explicitly discussed. Results show that the flow and the skin friction coefficient depend heavily on the velocity slip factor. In addition, the effects of all the parameters mentioned above were more pronounced for plane flows than for axisymmetric flows.Keywords: slip flow, axisymmetric flow, homotopy analysismethod, stagnation-point.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1705409 Wave Interaction with Defects in Pressurized Composite Structures
Authors: R. K. Apalowo, D. Chronopoulos, V. Thierry
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A wave finite element (WFE) and finite element (FE) based computational method is presented by which the dispersion properties as well as the wave interaction coefficients for one-dimensional structural system can be predicted. The structural system is discretized as a system comprising a number of waveguides connected by a coupling joint. Uniform nodes are ensured at the interfaces of the coupling element with each waveguide. Then, equilibrium and continuity conditions are enforced at the interfaces. Wave propagation properties of each waveguide are calculated using the WFE method and the coupling element is modelled using the FE method. The scattering of waves through the coupling element, on which damage is modelled, is determined by coupling the FE and WFE models. Furthermore, the central aim is to evaluate the effect of pressurization on the wave dispersion and scattering characteristics of the prestressed structural system compared to that which is not prestressed. Numerical case studies are exhibited for two waveguides coupled through a coupling joint.Keywords: Finite element, prestressed structures, wave finite element, wave propagation properties, wave scattering coefficients.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 951408 Performance of Modified Wedge Anchorage System for Pre-Stressed FRP Bars
Authors: Othman S. Alsheraida, Sherif El-Gamal
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Fiber Reinforced Polymer (FRP) is a composite material with exceptional properties that are capable to replace conventional steel reinforcement in reinforced and pre-stressed concrete structures. However, the main obstacle for their wide use in pre-stressed concrete application is the anchorage system. Due to the weakness of FRP in the transverse direction, the pre-stressing capacity of FRP bars are limited. This paper investigates the modification of the conventional wedge anchorage system to be used for stressing of FRP bars in pre-stressed applications. Epoxy adhesive material with glass FRP (GFRP) bars and conventional steel wedge were used in this paper. The GFRP bars are encased with epoxy at the anchor zone and the wedge system was used in pull-out test. The results showed a loading capacity of 47.6 kN which is 69% of the bar ultimate capacity. Additionally, nylon wedge was made with the same dimensions of the steel wedge and tested for GFRP bars without epoxy layer. The nylon wedge showed a loading capacity of 19.7 kN which is only 28.5% of the ultimate bar capacity.
Keywords: Anchorage, concrete, epoxy, FRP, pre-stressed.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2518407 When Scientific Laws and Findings Encounter Life: A Traditional Chinese Medicine Perspective
Authors: Eric Y. Zhang, L. Acu
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This paper is to point out the limitations of modern medical research and why the Traditional Chinese Medicine (TCM) can help address the limitations. Many of the modern medical research results are based on the findings in fundamental research disciplines, such as physics, and chemistry. However, this foundation is not as solid as it seems. The theory proposed in this paper, the Law of Chasm, or the Chasm Theory, states that there are two categories of objects to be studied. One is non-life objects, or lifeless objects; the other is living beings, or the objects that are alive. The laws and findings obtained by studying non-life objects may not all be extended to living beings, and vice versa. TCM is the study of medicine based on living beings. Therefore, TCM findings may not exist in the body of the knowledge obtained from studying non-life objects.
Keywords: TCM, Traditional Chinese Medicine, Law of Chasm, Chasm Theory, living-beings, non-life.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 254406 Conventional Synthesis and Characterization of Zirconium Molybdate, Nd2Zr3(MoO4)9
Authors: G. Çelik Gül, F. Kurtuluş
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Rare earths containing complex metal oxides have drawn much attention due to physical, chemical and optical properties which make them feasible in so many areas such as non-linear optical materials and ion exchanger. We have researched a systematic study to obtain rare earth containing zirconium molybdate compound, characterization, investigation of crystal system and calculation of unit cell parameters. After a successful synthesis of Nd2Zr3(MoO4)9 which is a member of rare earth metal containing complex oxides family, X-ray diffraction (XRD), High Score Plus/Rietveld refinement analysis, and Fourier Transform Infrared Spectroscopy (FTIR) were completed to determine the crystal structure. Morphological properties and elemental composition were determined by scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) analysis. Thermal properties were observed via Thermogravimetric-differential thermal analysis (TG/DTA).Keywords: Nd2Zr3(MoO4)9, solid state synthesis, powder x-ray diffraction, zirconium molybdates.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1094405 Magnesium Borate Synthesis by Microwave Method Using MgCl2.6H2O and H3BO3
Authors: A. S. Kipcak, P. Gurses, K. Kunt, E. Moroydor Derun, S. Piskin
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There are many kinds of metal borates found not only in nature but also synthesized in the laboratory such as magnesium borates. Due to its excellent properties, as remarkable ceramic materials, they have also application areas in anti-wear and friction reducing additives as well as electro-conductive treating agents. The synthesis of magnesium borate powders can be fulfilled simply with two different methods, hydrothermal and thermal synthesis. Microwave assisted method, also another way of producing magnesium borate, can be classified into thermal synthesis because of using the principles of solid state synthesis. It also contributes producing particles with small size and high purity in nano-size material synthesize. In this study the production of magnesium borates, are aimed using MgCl2.6H2O and H3BO3. The identification of both starting materials and products were made by the equipments of, X-Ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FT-IR). After several synthesis steps magnesium borates were synthesized and characterized by XRD and FT-IR, as well.Keywords: FT-IR, magnesium borates, microwave method, XRD.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2564404 Design Optimization of Cutting Parameters when Turning Inconel 718 with Cermet Inserts
Authors: M. Aruna, V. Dhanalaksmi
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Inconel 718, a nickel based super-alloy is an extensively used alloy, accounting for about 50% by weight of materials used in an aerospace engine, mainly in the gas turbine compartment. This is owing to their outstanding strength and oxidation resistance at elevated temperatures in excess of 5500 C. Machining is a requisite operation in the aircraft industries for the manufacture of the components especially for gas turbines. This paper is concerned with optimization of the surface roughness when turning Inconel 718 with cermet inserts. Optimization of turning operation is very useful to reduce cost and time for machining. The approach is based on Response Surface Method (RSM). In this work, second-order quadratic models are developed for surface roughness, considering the cutting speed, feed rate and depth of cut as the cutting parameters, using central composite design. The developed models are used to determine the optimum machining parameters. These optimized machining parameters are validated experimentally, and it is observed that the response values are in reasonable agreement with the predicted values.Keywords: Inconel 718, Optimization, Response Surface Methodology (RSM), Surface roughness
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2841403 Analysis of Hollow Rollers Implementation in Flexible Manufacturing of Large Bearings
Authors: S. Barabas, A.Fota.
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In this paper is study the possibility of successfully implementing of hollow roller concept in order to minimize inertial mass of the large bearings, with major results in diminution of the material consumption, increasing of power efficiency (in wind power station area), increasing of the durability and life duration of the large bearings systems, noise reduction in working, resistance to vibrations, an important diminution of losses by abrasion and reduction of the working temperature. In this purpose was developed an original solution through which are reduced mass, inertial forces and moments of large bearings by using of hollow rollers. The research was made by using the method of finite element analysis applied on software type Solidworks - Nastran. Also, is study the possibility of rapidly changing the manufacturing system of solid and hollow cylindrical rollers.Keywords: Large bearings, Von Mises stress, hollow rollers, flexible manufacturing system
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2251402 Effect of Curing Temperature on Mechanical Properties of Jute Fiber Reinforced Polylactic Acid Based Green Composite
Authors: Sehijpal Singh Khangura, Jai Inder Preet Singh, Vikas Dhawan
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Global warming, growing awareness of the environment, waste management issues, dwindling fossil resources, and rising oil prices resulted to increase the research in the materials that are friendly to our health and environment. Due to these reasons, green products are increasingly being promoted for sustainable development. In this work, fully biodegradable green composites have been developed using jute fibers as reinforcement and poly lactic acid as matrix material by film stacking technique. The effect of curing temperature during development of composites ranging from 160 °C, 170 °C, 180 °C and 190 °C was investigated for various mechanical properties. Results obtained from various tests indicate that impact strength decreases with an increase in curing temperature, but tensile and flexural strength increases till 180 °C, thereafter both the properties decrease. This study gives an optimum curing temperature for the development of jute/PLA composites.Keywords: Natural fibers, polymer matrix composites, jute, compression molding, biodegradation.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1065401 Mathematical Modeling of an Avalanche Release and Estimation of Flow Parameters by Numerical Method
Authors: Mahmoud Zarrini
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Avalanche release of snow has been modeled in the present studies. Snow is assumed to be represented by semi-solid and the governing equations have been studied from the concept of continuum approach. The dynamical equations have been solved for two different zones [starting zone and track zone] by using appropriate initial and boundary conditions. Effect of density (ρ), Eddy viscosity (η), Slope angle (θ), Slab depth (R) on the flow parameters have been observed in the present studies. Numerical methods have been employed for computing the non linear differential equations. One of the most interesting and fundamental innovation in the present studies is getting initial condition for the computation of velocity by numerical approach. This information of the velocity has obtained through the concept of fracture mechanics applicable to snow. The results on the flow parameters have found to be in qualitative agreement with the published results.
Keywords: Snow avalanche, fracture mechanics, avalanche velocity, avalanche zones.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1776400 Investigation of Dissolution in Diammonium Hydrogen Phosphate Solutions of Gypsum
Authors: Turan Çalban, Nursel Keskin, Sabri Çolak, Soner Kuşlu
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Gypsum (CaSO4.2H2O) is a mineral that is found in large quantities in the Turkey and in the World. In this study, the dissolution of this mineral in the diammonium hydrogen phosphate solutions has been studied. The dissolution and dissolution kinetics of gypsum in diammonium hydrogen phosphate solutions will be useful for evaluating of solid wastes containing gypsum. Parameters such as diammonium hydrogen phosphate concentration, temperature and stirring speed affecting on the dissolution rate of the gypsum in diammonium hydrogen phosphate solutions were investigated. In experimental studies have researched effectiveness of the selected parameters. The dissolution of gypsum were examined in two parts at low and high temperatures. The experimental results were successfully correlated by linear regression using Statistica program. Dissolution curves were evaluated shrinking core models for solidfluid systems. The activation energy was found to be 34.58 kJ/mol and 44.45 kJ/mol for the low and the high temperatures. The dissolution of gypsum was controlled by chemical reaction both low temperatures and high temperatures.
Keywords: Diammonium hydrogen phosphate, Dissolution, Gypsum, Kinetics.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 2053399 Extraction of Natural Colorant from the Flowers of Flame of Forest Using Ultrasound
Authors: Sunny Arora, Meghal A. Desai
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An impetus towards green consumerism and implementation of sustainable techniques, consumption of natural products and utilization of environment friendly techniques have gained accelerated acceptance. Butein, a natural colorant, has many medicinal properties apart from its use in dyeing industries. Extraction of butein from the flowers of flame of forest was carried out using ultrasonication bath. Solid loading (2-6 g), extraction time (30-50 min), volume of solvent (30-50 mL) and types of solvent (methanol, ethanol and water) have been studied to maximize the yield of butein using the Taguchi method. The highest yield of butein 4.67% (w/w) was obtained using 4 g of plant material, 40 min of extraction time and 30 mL volume of methanol as a solvent. The present method provided a greater reduction in extraction time compared to the conventional method of extraction. Hence, the outcome of the present investigation could further be utilized to develop the method at a higher scale.
Keywords: Butein, flowers of flame of forest, Taguchi method, ultrasonic bath.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 960398 Vibration Control of a Cantilever Beam Using a Tunable Vibration Absorber Embedded with ER Fluids
Authors: Chih-Jer Lin, Chun-Ying Lee, Chiang-Ho Cheng, Geng-Fung Chen
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This paper investigates experimental studies on vibration suppression for a cantilever beam using an Electro-Rheological (ER) sandwich shock absorber. ER fluid (ERF) is a class of smart materials that can undergo significant reversible changes immediately in its rheological and mechanical properties under the influence of an applied electric field. Firstly, an ER sandwich beam is fabricated by inserting a starch-based ERF into a hollow composite beam. At the same time, experimental investigations are focused on the frequency response of the ERF sandwich beam. Second, the ERF sandwich beam is attached to a cantilever beam to become as a shock absorber. Finally, a fuzzy semi-active vibration control is designed to suppress the vibration of the cantilever beam via the ERF sandwich shock absorber. To check the consistency of the proposed fuzzy controller, the real-time implementation validated the performance of the controller.
Keywords: Electro-Rheological Fluid, Semi-active vibration control, shock absorber, fuzzy control, Real-time control.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 3229397 Land Reclamation Using Waste as Fill Material: A Case Study in Jakarta
Authors: Q. Han, W. Schaefer, N. Barry
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To coop with urbanization issues and the economic need for expansion, the city of Jakarta is planning to reclaim more land in the Jakarta Bay. However, the reclamation activities of some islands have barely started and already the developers are facing difficulties in finding sufficient quantities of sand as fill material. When addressing the problem of sand scarcity in the case of Jakarta where, an excess of waste production, an inadequate solid waste management system and a lack of dumping ground pose a major problem, it is hard not to think of the use of waste as alternative fill material. This paper analyses the possibilities of using waste in the land reclamation projects, considering the governmental, social, environmental and economic context of the city. The results identify types of waste that could be used, ways of using those types of waste and implementation conditions for the city of Jakarta.
Keywords: Waste Management systems, Land reclamation, Multi Criteria Analysis, Scenario planning.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 5362396 Sorption of Congo Red from Aqueous Solution by Surfactant-Modified Bentonite: Kinetic and Factorial Design Study
Authors: B. Guezzen, M. A. Didi, B. Medjahed
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An organoclay (HDTMA-B) was prepared from sodium bentonite (Na-B). The starting material was modified using the hexadecyltrimethylammonium ion (HDTMA+) in the amounts corresponding to 100 % of the CEC value. Batch experiments were carried out in order to model and optimize the sorption of Congo red dye from aqueous solution. The pseudo-first order and pseudo-second order kinetic models have been developed to predict the rate constant and the sorption capacity at equilibrium with the effect of temperature, the solid/solution ratio and the initial dye concentration. The equilibrium time was reached within 60 min. At room temperature (20 °C), optimum dye sorption of 49.4 mg/g (98.9%) was achieved at pH 6.6, sorbent dosage of 1g/L and initial dye concentration of 50 mg/L, using surfactant modified bentonite. The optimization of adsorption parameters mentioned above on dye removal was carried out using Box-Behnken design. The sorption parameters were analyzed statistically by means of variance analysis by using the Statgraphics Centurion XVI software.
Keywords: Adsorption, dye, factorial design, kinetic, organo-bentonite.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1495395 Correlation to Predict the Effect of Particle Type on Axial Voidage Profile in Circulating Fluidized Beds
Authors: M. S. Khurram, S. A. Memon, S. Khan
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Bed voidage behavior among different flow regimes for Geldart A, B, and D particles (fluid catalytic cracking catalyst (FCC), particle A and glass beads) of diameter range 57-872 μm, apparent density 1470-3092 kg/m3, and bulk density range 890-1773 kg/m3 were investigated in a gas-solid circulating fluidized bed of 0.1 m-i.d. and 2.56 m-height of plexi-glass. Effects of variables (gas velocity, particle properties, and static bed height) were analyzed on bed voidage. The axial voidage profile showed a typical trend along the riser: a dense bed at the lower part followed by a transition in the splash zone and a lean phase in the freeboard. Bed expansion and dense bed voidage increased with an increase of gas velocity as usual. From experimental results, a generalized model relationship based on inverse fluidization number for dense bed voidage from bubbling to fast fluidization regimes was presented.
Keywords: Axial voidage, circulating fluidized bed, splash zone, static bed.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1274394 Sulfate Attack on Pastes Made with Different C3A and C4AF Contents and Stored at 5°C
Authors: Konstantinos Sotiriadis, Radosław Mróz
Abstract:
In the present work the internal sulfate attack on pastes made from pure clinker phases was studied. Two binders were produced: (a) a binder with 2% C3A and 18% C4AF content; (b) a binder with 10% C3A and C4AF content each. Gypsum was used as the sulfate bearing compound, while calcium carbonate added to differentiate the binders produced. The phases formed were identified by XRD analysis. The results showed that ettringite was the deterioration phase detected in the case of the low C3A content binder. Carbonation occurred in the specimen without calcium carbonate addition, while portlandite was observed in the one containing calcium carbonate. In the case of the high C3A content binder, traces of thaumasite were detected when calcium carbonate was not incorporated in the binder. A solid solution of thaumasite and ettringite was found when calcium carbonate was added. The amount of C3A had not fully reacted with sulfates, since its corresponding peaks were detected.
Keywords: Tricalcium aluminate, calcium aluminate ferrite, sulfate attack, calcium carbonate, low temperature.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 1978393 Aerodynamic Analysis and Design of Banners for Remote-Controlled Aircraft
Authors: Peyman Honarmandi, Mazen Alhirsh
Abstract:
Banner towing is a major form of advertisement. It consists of a banner showing a logo or a selection of words or letters being towed by an aircraft. Traditionally bush planes have been used to tow banners given their high thrust capabilities, however, with the development of Remote-Controlled (RC) aircraft, they could be a good replacement as RC planes mitigate the risk of human life and can be easier to operate. This paper studies the best banner design to be towed by an RC aircraft. This is done by conducting wind tunnel testing on an array of banners with different materials and designs. A pull gauge is used to record the drag force during testing which is then used to calculate the coefficient of drag, Cd. The testing results show that the best banner design would be a hybrid design with a solid and mesh material. The design with the lowest Cd of 0.082 was a half ripstop nylon half polyester mesh design. On the other hand, the design with highest Cd of 0.305 involved incorporating a tail chute to decrease fluttering.
Keywords: Aerodynamics of banner, banner design, banner towing, drag coefficients of banner, RC aircraft banner.
Procedia APA BibTeX Chicago EndNote Harvard JSON MLA RIS XML ISO 690 PDF Downloads 582