Search results for: absorbed energy
5576 An Integrated Approach to Solid Waste Management of Karachi, Pakistan (Waste-to-Energy Options)
Authors: Engineer Dilnawaz Shah
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Solid Waste Management (SWM) is perhaps one of the most important elements constituting the environmental health and sanitation of the urban developing sector. The management system has several components that are integrated as well as interdependent; thus, the efficiency and effectiveness of the entire system are affected when any of its functional components fails or does not perform up to the level mark of operation. Sindh Solid Waste Management Board (SSWMB) is responsible for the management of solid waste in the entire city. There is a need to adopt the engineered approach in the redesigning of the existing system. In most towns, street sweeping operations have been mechanized and done by machinery operated by vehicles. Construction of Garbage Transfer Stations (GTS) at a number of locations within the city will cut the cost of transportation of waste to disposal sites. Material processing, recovery of recyclables, compaction, volume reduction, and increase in density will enable transportation of waste to disposal sites/landfills via long vehicles (bulk transport), minimizing transport/traffic and environmental pollution-related issues. Development of disposal sites into proper sanitary landfill sites is mandatory. The transportation mechanism is through garbage vehicles using either hauled or fixed container systems employing crew for mechanical or manual loading. The number of garbage vehicles is inadequate, and due to comparatively long haulage to disposal sites, there are certain problems of frequent vehicular maintenance and high fuel costs. Foreign investors have shown interest in enterprising improvement schemes and proposed operating a solid waste management system in Karachi. The waste to Energy option is being considered to provide a practical answer to be adopted to generate power and reduce waste load – a two-pronged solution for the increasing environmental problem. The paper presents results and analysis of a recent study into waste generation and characterization probing into waste-to-energy options for Karachi City.Keywords: waste to energy option, integrated approach, solid waste management, physical and chemical composition of waste in Karachi
Procedia PDF Downloads 315575 Virtual Approach to Simulating Geotechnical Problems under Both Static and Dynamic Conditions
Authors: Varvara Roubtsova, Mohamed Chekired
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Recent studies on the numerical simulation of geotechnical problems show the importance of considering the soil micro-structure. At this scale, soil is a discrete particle medium where the particles can interact with each other and with water flow under external forces, structure loads or natural events. This paper presents research conducted in a virtual laboratory named SiGran, developed at IREQ (Institut de recherche d’Hydro-Quebec) for the purpose of investigating a broad range of problems encountered in geotechnics. Using Discrete Element Method (DEM), SiGran simulated granular materials directly by applying Newton’s laws to each particle. The water flow was simulated by using Marker and Cell method (MAC) to solve the full form of Navier-Stokes’s equation for non-compressible viscous liquid. In this paper, examples of numerical simulation and their comparisons with real experiments have been selected to show the complexity of geotechnical research at the micro level. These examples describe transient flows into a porous medium, interaction of particles in a viscous flow, compacting of saturated and unsaturated soils and the phenomenon of liquefaction under seismic load. They also provide an opportunity to present SiGran’s capacity to compute the distribution and evolution of energy by type (particle kinetic energy, particle internal elastic energy, energy dissipated by friction or as a result of viscous interaction into flow, and so on). This work also includes the first attempts to apply micro discrete results on a macro continuum level where the Smoothed Particle Hydrodynamics (SPH) method was used to resolve the system of governing equations. The material behavior equation is based on the results of simulations carried out at a micro level. The possibility of combining three methods (DEM, MAC and SPH) is discussed.Keywords: discrete element method, marker and cell method, numerical simulation, multi-scale simulations, smoothed particle hydrodynamics
Procedia PDF Downloads 2915574 Compliance Of Dialysis patients With Nutrition Guidelines: Insights From A Questionnaire
Authors: Zeiler M., Stadler D., Schmaderer C.
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Over the years of dialysis treatment, most patients experience significant weight loss. The primary emphasis in earlier research was the underlying mechanism of protein energy wasting and the subsequent malnutrition inflammation syndrome. In the interest to provide an effective and rapid solution for the patients, the aim of this study is identifying individual influences of their assumed reduced dietary intake, such as nausea, appetite loss and taste changes, and to determine whether the patients adhere to their nutrition guidelines. A prospective, controlled study with 38 end-stage renal disease patients was performed using a questionnaire to reflect their diet within the last 12 months. Thereby, the daily intake for the most important macro-and micronutrients was calculated to be compared with the individual KDQOI-guideline value, as well as controls matched in age and gender. The majority of the study population did not report symptoms commonly associated with dialysis, such as nausea or inappetence, and denied any change in dietary behavior since receiving renal replacement therapy. The patients’ daily intake of energy (3080kcal ± 1266) and protein (89,9g [53,4-142,0]) did not differ significantly from the controls (energy intake: 3233kcal ± 1046, p=0,597; protein intake: 103,7g [90,1-125,5], p=0,120). The average difference to the individual calculated KDQOI-guideline was +176,0kcal ± 1156 (p=0,357) for energy intake and -1,75g ± 45,9 (p=0,491) for protein intake. However, there was an observed imbalance in the distribution of macronutrients, with a preference for fats over proteins. The patients’ daily intake of sodium (5,4g [ 2,95-10,1]) was higher than in the controls (4,1g [2,04-5,99], p= 0,058) whereas both values for potassium (3,7g ± 1,84) and phosphorous (1,79g ± 0,91) went significantly below the controls’ values (potassium intake: 4,89g ± 1,74, p=0,014; phosphorous intake: 2,04g ± 0,64, p=0,038). Thus, the values exceeded the calculated KDQOI-recommendation by + 3,3g [0,63-7,90] (p<0,001) for sodium, +1,49g ± 1,84 (p<0,001) for potassium and +0,89g ± 0,91 (p<0,001) for phosphorous. Contrary to the assumption, the patients did not under-eat. Nevertheless, their diets did not align with the recommended values. These findings highlight the need for intervention and education among patients and that regular dietary monitoring could prevent unhealthy nutrition habits. The elaboration of individual references instead of standardized guidelines could increase the compliance to the advised diet so that interdisciplinary comorbidities do not develop or worsen.Keywords: compliance, dialysis, end-stage renal disease, KDQOI, malnutrition, nutrition guidelines, questionnaire, salt intake
Procedia PDF Downloads 615573 Informed Urban Design: Minimizing Urban Heat Island Intensity via Stochastic Optimization
Authors: Luis Guilherme Resende Santos, Ido Nevat, Leslie Norford
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The Urban Heat Island (UHI) is characterized by increased air temperatures in urban areas compared to undeveloped rural surrounding environments. With urbanization and densification, the intensity of UHI increases, bringing negative impacts on livability, health and economy. In order to reduce those effects, it is required to take into consideration design factors when planning future developments. Given design constraints such as population size and availability of area for development, non-trivial decisions regarding the buildings’ dimensions and their spatial distribution are required. We develop a framework for optimization of urban design in order to jointly minimize UHI intensity and buildings’ energy consumption. First, the design constraints are defined according to spatial and population limits in order to establish realistic boundaries that would be applicable in real life decisions. Second, the tools Urban Weather Generator (UWG) and EnergyPlus are used to generate outputs of UHI intensity and total buildings’ energy consumption, respectively. Those outputs are changed based on a set of variable inputs related to urban morphology aspects, such as building height, urban canyon width and population density. Lastly, an optimization problem is cast where the utility function quantifies the performance of each design candidate (e.g. minimizing a linear combination of UHI and energy consumption), and a set of constraints to be met is set. Solving this optimization problem is difficult, since there is no simple analytic form which represents the UWG and EnergyPlus models. We therefore cannot use any direct optimization techniques, but instead, develop an indirect “black box” optimization algorithm. To this end we develop a solution that is based on stochastic optimization method, known as the Cross Entropy method (CEM). The CEM translates the deterministic optimization problem into an associated stochastic optimization problem which is simple to solve analytically. We illustrate our model on a typical residential area in Singapore. Due to fast growth in population and built area and land availability generated by land reclamation, urban planning decisions are of the most importance for the country. Furthermore, the hot and humid climate in the country raises the concern for the impact of UHI. The problem presented is highly relevant to early urban design stages and the objective of such framework is to guide decision makers and assist them to include and evaluate urban microclimate and energy aspects in the process of urban planning.Keywords: building energy consumption, stochastic optimization, urban design, urban heat island, urban weather generator
Procedia PDF Downloads 1245572 Modeling of Enthalpy and Heat Capacity of Phase-Change Materials
Authors: Igor Medved, Anton Trnik, Libor Vozar
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Phase-change materials (PCMs) are of great interest in the applications where a temperature level needs to be maintained and/or where there is demand for thermal energy storage. Examples are storage of solar energy, cold, and space heating/cooling of buildings. During a phase change, the enthalpy vs. temperature plot of PCMs shows a jump and there is a distinct peak in the heat capacity plot. We present a theoretical description from which these jumps and peaks can be obtained. We apply our theoretical results to fit experimental data with very good accuracy for selected materials and changes between two phases. The development is based on the observation that PCMs are polycrystalline; i.e., composed of many single-crystalline grains. The enthalpy and heat capacity are thus interpreted as averages of the contributions from the individual grains. We also show how to determine the baseline and excess part of the heat capacity and thus the latent heat corresponding to the phase change.Keywords: averaging, enthalpy jump, heat capacity peak, phase change
Procedia PDF Downloads 4475571 Impact of Fischer-Tropsch Wax on Ethylene Vinyl Acetate/Waste Crumb Rubber Modified Bitumen: An Energy-Sustainability Nexus
Authors: Keith D. Nare, Mohau J. Phiri, James Carson, Chris D. Woolard, Shanganyane P. Hlangothi
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In an energy-intensive world, minimizing energy consumption is paramount to cost saving and reducing the carbon footprint. Improving mixture procedures utilizing warm mix additive Fischer-Tropsch (FT) wax in ethylene vinyl acetate (EVA) and modified bitumen highlights a greener and sustainable approach to modified bitumen. In this study, the impact of FT wax on optimized EVA/waste crumb rubber modified bitumen is assayed with a maximum loading of 2.5%. The rationale of the FT wax loading is to maintain the original maximum loading of EVA in the optimized mixture. The phase change abilities of FT wax enable EVA co-crystallization with the support of the elastomeric backbone of crumb rubber. Less than 1% loading of FT wax worked in the EVA/crumb rubber modified bitumen energy-sustainability nexus. Response surface methodology approach to the mixture design is implemented amongst the different loadings of FT wax, EVA for a consistent amount of crumb rubber and bitumen. Rheological parameters (complex shear modulus, phase angle and rutting parameter) were the factors used as performance indicators of the different optimized mixtures. The low temperature chemistry of the optimized mixtures is analyzed using elementary beam theory and the elastic-viscoelastic correspondence principle. Master curves and black space diagrams are developed and used to predict age-induced cracking of the different long term aged mixtures. Modified binder rheology reveals that the strain response is not linear and that there is substantial re-arrangement of polymer chains as stress is increased, this is based on the age state of the mixture and the FT wax and EVA loadings. Dominance of individual effects is evident over effects of synergy in co-interaction of EVA and FT wax. All-inclusive FT wax and EVA formulations were best optimized in mixture 4 with mixture 7 reflecting increase in ease of workability. Findings show that interaction chemistry of bitumen, crumb rubber EVA, and FT wax is first and second order in all cases involving individual contributions and co-interaction amongst the components of the mixture.Keywords: bitumen, crumb rubber, ethylene vinyl acetate, FT wax
Procedia PDF Downloads 1665570 Catalytic Dehydrogenation of Formic Acid into H2/CO2 Gas: A Novel Approach
Authors: Ayman Hijazi, Witold Kwapinski, J. J. Leahy
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Finding a sustainable alternative energy to fossil fuel is an urgent need as various environmental challenges in the world arise. Therefore, formic acid (FA) decomposition has been an attractive field that lies at the center of biomass platform, comprising a potential pool of hydrogen energy that stands as a new energy vector. Liquid FA features considerable volumetric energy density of 6.4 MJ/L and a specific energy density of 5.3 MJ/Kg that qualifies it in the prime seat as an energy source for transportation infrastructure. Additionally, the increasing research interest in FA decomposition is driven by the need of in-situ H2 production, which plays a key role in the hydrogenation reactions of biomass into higher value components. It is reported elsewhere in literature that catalytic decomposition of FA is usually performed in poorly designed setup using simple glassware under magnetic stirring, thus demanding further energy investment to retain the used catalyst. it work suggests an approach that integrates designing a novel catalyst featuring magnetic property with a robust setup that minimizes experimental & measurement discrepancies. One of the most prominent active species for dehydrogenation/hydrogenation of biomass compounds is palladium. Accordingly, we investigate the potential of engrafting palladium metal onto functionalized magnetic nanoparticles as a heterogeneous catalyst to favor the production of CO-free H2 gas from FA. Using ordinary magnet to collect the spent catalyst renders core-shell magnetic nanoparticles as the backbone of the process. Catalytic experiments were performed in a jacketed batch reactor equipped with an overhead stirrer under inert medium. Through a novel approach, FA is charged into the reactor via high-pressure positive displacement pump at steady state conditions. The produced gas (H2+CO2) was measured by connecting the gas outlet to a measuring system based on the amount of the displaced water. The novelty of this work lies in designing a very responsive catalyst, pumping consistent amount of FA into a sealed reactor running at steady state mild temperatures, and continuous gas measurement, along with collecting the used catalyst without the need for centrifugation. Catalyst characterization using TEM, XRD, SEM, and CHN elemental analyzer provided us with details of catalyst preparation and facilitated new venues to alter the nanostructure of the catalyst framework. Consequently, the introduction of amine groups has led to appreciable improvements in terms of dispersion of the doped metals and eventually attaining nearly complete conversion (100%) of FA after 7 hours. The relative importance of the process parameters such as temperature (35-85°C), stirring speed (150-450rpm), catalyst loading (50-200mgr.), and Pd doping ratio (0.75-1.80wt.%) on gas yield was assessed by a Taguchi design-of-experiment based model. Experimental results showed that operating at lower temperature range (35-50°C) yielded more gas while the catalyst loading and Pd doping wt.% were found to be the most significant factors with a P-values 0.026 & 0.031, respectively.Keywords: formic acid decomposition, green catalysis, hydrogen, mesoporous silica, process optimization, nanoparticles
Procedia PDF Downloads 445569 Model Predictive Control Applied to Thermal Regulation of Thermoforming Process Based on the Armax Linear Model and a Quadratic Criterion Formulation
Authors: Moaine Jebara, Lionel Boillereaux, Sofiane Belhabib, Michel Havet, Alain Sarda, Pierre Mousseau, Rémi Deterre
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Energy consumption efficiency is a major concern for the material processing industry such as thermoforming process and molding. Indeed, these systems should deliver the right amount of energy at the right time to the processed material. Recent technical development, as well as the particularities of the heating system dynamics, made the Model Predictive Control (MPC) one of the best candidates for thermal control of several production processes like molding and composite thermoforming to name a few. The main principle of this technique is to use a dynamic model of the process inside the controller in real time in order to anticipate the future behavior of the process which allows the current timeslot to be optimized while taking future timeslots into account. This study presents a procedure based on a predictive control that brings balance between optimality, simplicity, and flexibility of its implementation. The development of this approach is progressive starting from the case of a single zone before its extension to the multizone and/or multisource case, taking thus into account the thermal couplings between the adjacent zones. After a quadratic formulation of the MPC criterion to ensure the thermal control, the linear expression is retained in order to reduce calculation time thanks to the use of the ARMAX linear decomposition methods. The effectiveness of this approach is illustrated by experiment and simulation.Keywords: energy efficiency, linear decomposition methods, model predictive control, mold heating systems
Procedia PDF Downloads 2625568 Natural Patterns for Sustainable Cooling in the Architecture of Residential Buildings in Iran (Hot and Dry Climate)
Authors: Elnaz Abbasian, Mohsen Faizi
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In its thousand-year development, architecture has gained valuable patterns. Iran’s desert regions possess developed patterns of traditional architecture and outstanding skeletal features. Unfortunately increasing population and urbanization growth in the past decade as well as the lack of harmony with environment’s texture has destroyed such permanent concepts in the building’s skeleton, causing a lot of energy waste in the modern architecture. The important question is how cooling patterns of Iran’s traditional architecture can be used in a new way in the modern architecture of residential buildings? This research is library-based and documental that looks at sustainable development, analyzes the features of Iranian architecture in hot and dry climate in terms of sustainability as well as historical patterns, and makes a model for real environment. By methodological analysis of past, it intends to suggest a new pattern for residential buildings’ cooling in Iran’s hot and dry climate which is in full accordance to the ecology of the design and at the same time possesses the architectural indices of the past. In the process of cities’ physical development, ecological measures, in proportion to desert’s natural background and climate conditions, has kept the natural fences, preventing buildings from facing climate adversities. Designing and construction of buildings with this viewpoint can reduce the energy needed for maintaining and regulating environmental conditions and with the use of appropriate building technology help minimizing the consumption of fossil fuels while having permanent patterns of desert buildings’ architecture.Keywords: sustainability concepts, sustainable development, energy climate architecture, fossil fuel, hot and dry climate, patterns of traditional sustainability for residential buildings, modern pattern of cooling
Procedia PDF Downloads 2945567 Water-Energy-Food Nexus Model for India: A Way Forward for Achieving Sustainable Development Goals
Authors: Rajendra Singh, Krishna Mondal, Chandranath Chatterjee
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The water, energy, and food (WEF) nexus describes the interconnectedness of these three essential elements of human life. Each of these three sectors depends on the others. India's expanding population, urbanization, and industrialization make WEF nexus management difficult. Coupling and coordination degrees can be used as indicators of a complex system's level of sustainable development. Thus, coupling and coordination of WEF sectors in India are essential for achieving Sustainable Development Goals (SDGs) 2 (zero hunger), 6 (clean water and sanitation), and 7 (affordable and clean energy). This study used a newly developed WEF nexus model and the concept of coupling coordination degree model to examine the coupling and coordination degrees of the WEF nexus at India's sub-national scale (States/Union Territories (UTs)) for the years 2011 and 2021. Results indicate that the WEF nexus coupling degree was reasonably stable among the Indian States/UTs in both years, with all having a coupling degree above 0.90, indicating high-quality coupling. However, the degree of coordination varied spatially and temporally from ‘primary development’ to ‘quality development’ for the Indian States/UTs. In 2021, it went from 53% to 14% intermediate development and 44% to 83% good development compared to 2011. Most Indian States/UTs developed SDG2 more than SDG6 and SDG7. This study also suggests that most States/UTs must implement WEF-related policies and programmes effectively to achieve quality coordinated WEF nexus development. This study may help administrators and policymakers identify States/UTs that need more attention to implement existing or new policies for achieving SDGs 2, 6, and 7.Keywords: WEF nexus model, Pardee-RAND WEF nexus, sustainable development, policy
Procedia PDF Downloads 545566 Assessing the NYC's Single-Family Housing Typology for Urban Heat Vulnerability and Occupants’ Health Risk under the Climate Change Emergency
Authors: Eleni Stefania Kalapoda
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Recurring heat waves due to the global climate change emergency pose continuous risks to human health and urban resources. Local and state decision-makers incorporate Heat Vulnerability Indices (HVIs) to quantify and map the relative impact on human health in emergencies. These maps enable government officials to identify the highest-risk districts and to concentrate emergency planning efforts and available resources accordingly (e.g., to reevaluate the location and the number of heat-relief centers). Even though the framework of conducting an HVI is unique per municipality, its accuracy in assessing the heat risk is limited. To resolve this issue, varied housing-related metrics should be included. This paper quantifies and classifies NYC’s single detached housing typology within high-vulnerable NYC districts using detailed energy simulations and post-processing calculations. The results show that the variation in indoor heat risk depends significantly on the dwelling’s design/operation characteristics, concluding that low-ventilated dwellings are the most vulnerable ones. Also, it confirmed that when building-level determinants of exposure are excluded from the assessment, HVI fails to capture important components of heat vulnerability. Lastly, the overall vulnerability ratio of the housing units was calculated between 0.11 to 1.6 indoor heat degrees in terms of ventilation and shading capacity, insulation degree, and other building attributes.Keywords: heat vulnerability index, energy efficiency, urban heat, resiliency to heat, climate adaptation, climate mitigation, building energy
Procedia PDF Downloads 695565 Copper Coil Heat Exchanger Performance for Greenhouse Heating: An Experimental and Theoretical Study
Authors: Maha Bakkari, R.Tadili
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The present work is a study of the performance of a solar copper coil heating system in a greenhouse microclimate. Our system is based on the circulation of a Heat transfer fluid, which is water in our case, in a closed loop under the greenhouse's roof in order to store heat all day, and then this heat will supply the greenhouse during the night. In order to evaluate our greenhouse, we made an experimental study in two identical greenhouses, where the first one is equipped with a heating system and the second (without heating) is used for control. The heating system allows the establishment of the thermal balance and determines the mass of water necessary for the process in order to ensure its functioning during the night. The results obtained showed that this solar heating system and the climatic parameters inside the experimental greenhouse were improved, and it presents a significant gain compared to a controlled greenhouse without a heating system. This research is one of the solutions that help to reduce the greenhouse effect of the planet Earth, a problem that worries the world.Keywords: solar energy, energy storage, greenhouse, environment
Procedia PDF Downloads 685564 The Use of Superplastic Tin-Lead Alloy as A solid Lubricant in Free Upsetting of Aluminum and Brass
Authors: Adnan I. O. Zaid, Hebah B. Melhem, Ahmad Qandil
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The main function of a lubricant in any forming process is to reduce friction between the work piece and the die set, hence reducing the force and energy requirement for forming process and to achieve homogeneous deformation. The free upsetting test is an important open forging test. In this paper, super plastic tin-lead alloy is used as solid lubricant in the free upsetting test of non-ferrous metals and compared with eight different lubricants using the following three criteria: one comparing the value of the reduction in height percentages, i.e. the engineering strain, in identical specimens of the same material under the effect of the same compressive force. The second is comparing the amount of barreling produced in each of the identical specimens, at each lubricant. The third criterion is using the specific energy, i.e. the energy per unit volume consumed in forming each material, using the different lubricants to produce the same reduction in height percentage of identical specimens from each of the two materials, namely: aluminum and brass. It was found that the super plastic tin-lead alloy lubricant has produced higher values of reductions in height percentage and less barreling in the two non-ferrous materials, used in this work namely: aluminum and brass. It was found that the super plastic tin-lead alloy lubricant has produced higher values of reductions in height percentage and less barreling in the two non-ferrous materials, used in this work, under the same compression force among the different used lubricants.Keywords: aluminum, brass, different lubricants, free upsetting, solid lubricants, superplastic tin-lead alloy
Procedia PDF Downloads 4565563 An Energy Detection-Based Algorithm for Cooperative Spectrum Sensing in Rayleigh Fading Channel
Authors: H. Bakhshi, E. Khayyamian
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Cognitive radios have been recognized as one of the most promising technologies dealing with the scarcity of the radio spectrum. In cognitive radio systems, secondary users are allowed to utilize the frequency bands of primary users when the bands are idle. Hence, how to accurately detect the idle frequency bands has attracted many researchers’ interest. Detection performance is sensitive toward noise power and gain fluctuation. Since signal to noise ratio (SNR) between primary user and secondary users are not the same and change over the time, SNR and noise power estimation is essential. In this paper, we present a cooperative spectrum sensing algorithm using SNR estimation to improve detection performance in the real situation.Keywords: cognitive radio, cooperative spectrum sensing, energy detection, SNR estimation, spectrum sensing, rayleigh fading channel
Procedia PDF Downloads 4415562 Energy Dissipation Characteristics of an Elastomer under Dynamic Condition: A Comprehensive Assessment Using High and Low Frequency Analyser
Authors: K. Anas, M. Selvakumar, Samson David, R. R. Babu, S. Chattopadhyay
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The dynamic deformation of a visco elastic material can cause heat generation. This heat generation is aspect energy dissipation. The present work investigates the contribution of various factors like; elastomer structure, cross link type and density, filler networking, reinforcement potential and temperature at energy dissipation mechanism. The influences of these elements are investigated using very high frequency analyzer (VHF ) and dynamical mechanical analysis(DMA).VHF follows transmissibility and vibration isolation principle whereas DMA works on dynamical mechanical deformation principle. VHF analysis of different types of elastomers reveals that elastomer can act as a transmitter or damper of energy depending on the applied frequency ratio (ω/ωn). Dynamic modulus (G') of low damping rubbers like natural rubber does not varies rapidly with frequency but vice-versa for high damping rubber like butyl rubber (IIR). VHF analysis also depicts that polysulfidic linkages has high damping ratio (ζ) than mono sulfidic linkages due to its dissipative nature. At comparable cross link density, mono sulfidic linkages shows higher glass transition temperature (Tg) than poly sulfidic linkages. The intensity and location of loss modulus (G'') peak of different types of carbon black filled natural rubber compounds suggests that segmental relaxation at glass transition temperature (Tg) is seldom affected by filler particles, but the filler networks can influence the cross link density by absorbing the curatives. The filler network breaking and reformation during a dynamic strain is a thermally activated process. Thus, stronger aggregates are highly dissipative in nature. Measurements indicate that at lower temperature regimes polymeric chain friction is highly dissipative in nature.Keywords: damping ratio, natural frequency, crosslinking density, segmental motion, surface activity, dissipative, polymeric chain friction
Procedia PDF Downloads 2855561 Estimation of Rock Strength from Diamond Drilling
Authors: Hing Hao Chan, Thomas Richard, Masood Mostofi
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The mining industry relies on an estimate of rock strength at several stages of a mine life cycle: mining (excavating, blasting, tunnelling) and processing (crushing and grinding), both very energy-intensive activities. An effective comminution design that can yield significant dividends often requires a reliable estimate of the material rock strength. Common laboratory tests such as rod, ball mill, and uniaxial compressive strength share common shortcomings such as time, sample preparation, bias in plug selection cost, repeatability, and sample amount to ensure reliable estimates. In this paper, the authors present a methodology to derive an estimate of the rock strength from drilling data recorded while coring with a diamond core head. The work presented in this paper builds on a phenomenological model of the bit-rock interface proposed by Franca et al. (2015) and is inspired by the now well-established use of the scratch test with PDC (Polycrystalline Diamond Compact) cutter to derive the rock uniaxial compressive strength. The first part of the paper introduces the phenomenological model of the bit-rock interface for a diamond core head that relates the forces acting on the drill bit (torque, axial thrust) to the bit kinematic variables (rate of penetration and angular velocity) and introduces the intrinsic specific energy or the energy required to drill a unit volume of rock for an ideally sharp drilling tool (meaning ideally sharp diamonds and no contact between the bit matrix and rock debris) that is found well correlated to the rock uniaxial compressive strength for PDC and roller cone bits. The second part describes the laboratory drill rig, the experimental procedure that is tailored to minimize the effect of diamond polishing over the duration of the experiments, and the step-by-step methodology to derive the intrinsic specific energy from the recorded data. The third section presents the results and shows that the intrinsic specific energy correlates well to the uniaxial compressive strength for the 11 tested rock materials (7 sedimentary and 4 igneous rocks). The last section discusses best drilling practices and a method to estimate the rock strength from field drilling data considering the compliance of the drill string and frictional losses along the borehole. The approach is illustrated with a case study from drilling data recorded while drilling an exploration well in Australia.Keywords: bit-rock interaction, drilling experiment, impregnated diamond drilling, uniaxial compressive strength
Procedia PDF Downloads 1285560 Earthquake Forecasting Procedure Due to Diurnal Stress Transfer by the Core to the Crust
Authors: Hassan Gholibeigian, Kazem Gholibeigian
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In this paper, our goal is determination of loading versus time in crust. For this goal, we present a computational procedure to propose a cumulative strain energy time profile which can be used to predict the approximate location and time of the next major earthquake (M > 4.5) along a specific fault, which we believe, is more accurate than many of the methods presently in use. In the coming pages, after a short review of the research works presently going on in the area of earthquake analysis and prediction, earthquake mechanisms in both the jerk and sequence earthquake direction is discussed, then our computational procedure is presented using differential equations of equilibrium which govern the nonlinear dynamic response of a system of finite elements, modified with an extra term to account for the jerk produced during the quake. We then employ Von Mises developed model for the stress strain relationship in our calculations, modified with the addition of an extra term to account for thermal effects. For calculation of the strain energy the idea of Pulsating Mantle Hypothesis (PMH) is used. This hypothesis, in brief, states that the mantle is under diurnal cyclic pulsating loads due to unbalanced gravitational attraction of the sun and the moon. A brief discussion is done on the Denali fault as a case study. The cumulative strain energy is then graphically represented versus time. At the end, based on some hypothetic earthquake data, the final results are verified.Keywords: pulsating mantle hypothesis, inner core’s dislocation, outer core’s bulge, constitutive model, transient hydro-magneto-thermo-mechanical load, diurnal stress, jerk, fault behaviour
Procedia PDF Downloads 2685559 Experimental Study of Semitransparent and Opaque Photovoltaic Modules with and without Air Duct
Authors: Sanjay Agrawal, Trapti Varshney, G. N. Tiwari
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In this paper, thermal modeling has been developed for photovoltaic PV modules, namely; Case A: semitransparent PV module without duct, Case B: semitransparent PV module with duct, Case C: opaque PV module without duct, Case D: opaque PV module with duct for Delhi, India climatic condition. MATLAB 7.0 software has been used to solve mathematical models of the proposed system. For validation of proposed system, the experimental study has also been carried out for all above four cases, and then comparative analysis of all different type of PV module has been presented. The hybrid PVT module air collectors presented in this study are self sustaining the system and can be used for the electricity generation in remote areas where access of electricity is not economical due to high transmission and distribution losses. It has been found that overall annual thermal energy and exergy gain of semitransparent PV module is higher by 11.6% and7.32% in summer condition and 16.39% and 18% in winter condition respectively as compared to opaque PV module considering same area (0.61 m2) of PV module.Keywords: semitransparent PV module, overall exergy, overall thermal energy, opaque
Procedia PDF Downloads 4265558 Ionic Liquid Desiccant for the Dehumidification System
Authors: Chih-Hao Chen, Yu-Heng Fang, Jyi-Ching Perng, Wei-Chih Lee, Yi-Hsiang Chen, Jiun-Jen Chen
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Emerging markets are almost in the high temperature and high humidity area. Regardless of industry or domestic fields, the energy consumption of air conditioning systems in buildings is always significant. Moreover, the proportion of latent heat load is high. A liquid desiccant dehumidification system is one kind of energy-saving air conditioning system. However, traditional absorbents such as lithium chloride are hindered in market promotion because they will crystallized and cause metal corrosion. This study used the commercial ionic liquid to build a liquid desiccant dehumidification system with an air volume of 300 CMH. When the absolute humidity of the inlet air was 15g/kg, the absolute humidity of the outlet air was 10g/kg. The operating condition of a hot water temperature is 45 °C, and the cooling water temperature is 15 °C. The test result proves that the ionic liquid desiccant can completely replace the traditional liquid desiccant.Keywords: ionic liquid desiccant, dehumidification, heat pump, air conditioning systems
Procedia PDF Downloads 1565557 Anaerobic Digestion of Organic Wastes for Biogas Production
Authors: Ayhan Varol, Aysenur Ugurlu
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Due to the depletion of fossil fuels and climate change, there is a rising interest in renewable energy sources. In this concept, a wide range of biomass (energy crops, animal manure, solid wastes, etc.) are used for energy production. There has been a growing interest in biomethane production from biomass. Biomethane production from organic wastes is a promising alternative for waste management by providing organic matter stabilization. Anaerobic digestion of organic material produces biogas, and organic substrate is degraded into a more stable material. Therefore, anaerobic digestion technology helps reduction of carbon emissions and produces renewable energy. The hydraulic retention time (HRT) and organic loading rate (OLR), as well as TS (VS) loadings, influences the anaerobic digestion of organic wastes significantly. The optimum range for HRT varies between 15 days to 30 days, whereas OLR differs between 0.5 to 5 g/L.d depending on the substrate type and its lipid, protein and carbohydrate contents. The organic wastes have biogas production potential through anaerobic digestion. In this study, biomethane production potential of wastes like sugar beet bagasse, agricultural residues, food wastes, olive mill pulp, and dairy manure having different characteristics was investigated in mesophilic CSTR reactor, and their performances were compared. The reactor was mixed in order to provide homogenized content at a rate of 80 rpm. The organic matter content of these wastes was between 85 to 94 % with 61% (olive pulp) to 22 % (food waste) dry matter content. The hydraulic retention time changed between 20-30 days. High biogas productions, 13.45 to 5.70 mL/day, were achieved from the wastes studied when operated at 9 to 10.5% TS loadings where OLR varied between 2.92 and 3.95 gVS/L.day. The results showed that food wastes have higher specific methane production rate and volumetric methane production potential than the other wastes studied, under the similar OLR values. The SBP was 680, 585, 540, 390 and 295 mL/g VS for food waste, agricultural residues, sugar beet bagasse, olive pulp and dairy manure respectively. The methane content of the biogas varied between 72 and 60 %. The volatile solids conversion rate for food waste was 62%.Keywords: biogas production, organic wastes, biomethane, anaerobic digestion
Procedia PDF Downloads 2745556 Study on the Neurotransmitters and Digestion of Amino Acids Affecting Psychological Chemical Imbalance
Authors: Yoonah Lee, Richard Kyung
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With technological advances in the computational biomedical field, the ability to measure neurotransmitters’ chemical imbalances that affect depression and anxiety has been established. By comparing the thermodynamics stability of amino acid supplements, such as glutamine, tyrosine, phe-nylalanine, and methionine, this research analyzes mood-regulating neurotransmitters, amino acid supplements, and antipsychotic substances (ie. Reserpine molecule and CRF complexes) in relation to depression and anxiety and suggests alternative complexes that are low in energy to act as more efficient treatments for mood disorders. To determine a molecule’s thermodynamic stability, this research examines the molecular energy using Avogadro, a software for building virtual molecules and calculating optimized geometry using GAFF (General Amber Force Field) and UFF (Universal Force Field). The molecules, built using Avogadro, is analyzed using their theoretical values and atomic properties.Keywords: amino acids, anxiety, depression, neurotransmitters
Procedia PDF Downloads 1585555 Prediction Study of the Structural, Elastic and Electronic Properties of the Parent and Martensitic Phases of Nonferrous Ti, Zr, and Hf Pure Metals
Authors: Tayeb Chihi, Messaoud Fatmi
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We present calculations of the structural, elastic and electronic properties of nonferrous Ti, Zr, and Hf pure metals in both parent and martensite phases in bcc and hcp structures respectively. They are based on the generalized gradient approximation (GGA) within the density functional theory (DFT). The shear modulus, Young's modulus and Poisson's ratio for Ti, Zr, and Hf metals have were calculated and compared with the corresponding experimental values. Using elastic constants obtained from calculations GGA, the bulk modulus along the crystallographic axes of single crystals was calculated. This is in good agreement with experiment for Ti and Zr, whereas the hcp structure for Hf is a prediction. At zero temperature and zero pressure, the bcc crystal structure is found to be mechanically unstable for Ti, Zr, and Hf. In our calculations the hcp structures is correctly found to be stable at the equilibrium volume. In the electronic density of states (DOS), the smaller n(EF) is, the more stable the compound is. Therefore, in agreement with the results obtained from the total energy minimum.Keywords: Ti, Zr, Hf, pure metals, transformation, energy
Procedia PDF Downloads 3415554 The Manufacturing of Metallurgical Grade Silicon from Diatomaceous Silica by an Induction Furnace
Authors: Shahrazed Medeghri, Saad Hamzaoui, Mokhtar Zerdali
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The metallurgical grade silicon (MG-Si) is obtained from the reduction of silica (SiO2) in an induction furnace or an electric arc furnace. Impurities inherent in reduction process also depend on the quality of the raw material used. Among the applications of the silicon, it is used as a substrate for the photovoltaic conversion of solar energy and this conversion is wider as the purity of the substrate is important. Research is being done where the purpose is looking for new methods of manufacturing and purification of silicon, as well as new materials that can be used as substrates for the photovoltaic conversion of light energy. In this research, the technique of production of silicon in an induction furnace, using a high vacuum for fusion. Diatomaceous Silica (SiO2) used is 99 mass% initial purities, the carbon used is 6N of purity and the particle size of 63μm as starting materials. The final achieved purity of the material was above 50% by mass. These results demonstrate that this method is a technically reliable, and allows obtaining a better return on the amount 50% of silicon.Keywords: induction furnaces, amorphous silica, carbon microstructure, silicon
Procedia PDF Downloads 3945553 Discrete Crack Modeling of Side Face FRP-Strengthened Concrete Beam
Authors: Shahriar Shahbazpanahi, Mohammad Hemen Jannaty, Alaleh Kamgar
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Shear strengthening can be carried out in concrete structures by external fibre reinforced polymer (FRP). In the present investigation, a new fracture mechanics model is developed to model side face of strengthened concrete beam by external FRP. Discrete crack is simulated by a spring element with softening behavior ahead of the crack tip to model the cohesive zone in concrete. A truss element is used, parallel to the spring element, to simulate the energy dissipation rate by the FRP. The strain energy release rate is calculated directly by using a virtual crack closure technique and then, the crack propagation criterion is presented. The results are found acceptable when compared to previous experimental results and ABAQUS software data. It is observed that the length of the fracture process zone (FPZ) increases with the application of FRP in side face at the same load in comparison with that of the control beam.Keywords: FPZ, fracture, FRP, shear
Procedia PDF Downloads 5275552 Perception and Usage of Academic Social Networks among Scientists: A Cross-Sectional Study of North Indian Universities
Authors: Anita Chhatwal
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Purpose: The purpose of this paper is to evaluate and investigate the scope of usage of Academic Social Networking Websites (ASNs) by the Science faculty members across universities of North India, viz. Panjab University, Punjabi University and University of Delhi, Delhi. Design/Methodology/Approach: The present study is based upon the primary data collected from 81 science faculty participants from three universities of North India. Questionnaire method was used as an instrument for survey. The study is descriptive and research-based to investigate the popular ASNs amongst the participants from three sample universities and the purpose for which they use them along with the problems they encounter while using ASNs. Findings: The findings of the study revealed that majority of the participants were using ASNs for their academic needs. It was observed that majority of the participants (78%) used ASNs to access scientific papers, while 73.8% of the participants used them to share their research publications. ResearchGate (60.5%) and Google Scholar (59.7%) were the top two most preferred and widely used ASNs by the participants. The critical analysis of the data shows that laptops (86.3%) emerged as major tools for accessing ASNs. Shortage of computers was found to be the chief obstacle in accessing ASNs by the participants. Results of the study demonstrate that 56.3% of participants suggested conduct of seminars and training as the most effective method to increase the awareness of ASNs. Research Limitations/Implications: The study in hand absorbed the 81 faculty (Assistant Professors) members from 15 Science teaching departments across three sample universities of North India. The findings of this study will help the Government of India to regulate and simultaneously make effort to develop and enhance ASNs usage among faculty, researchers, and students. The present study will add to the existing library and information science literature and will be advantageous for all the information professionals as well. Originality/Value: This study is original survey based on primary data investigate the usage of ASNs by the academia. This study will be useful for research scholars, academicians and students all over the world.Keywords: academic social networks, awareness and usage, North India, scholarly communication, web 2.0
Procedia PDF Downloads 1055551 Analysis and the Fair Distribution Modeling of Urban Facilities in Kabul City
Authors: Ansari Mohammad Reza, Hiroko Ono, Fakhrullah Sarwari
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Our world is fast heading toward being a predominantly urban planet. This can be a double-edged sword reality where it is as much frightening as it seems interesting. Moreover, a look to the current predictions and taking into the consideration the fact that about 90 percent of the coming urbanization is going to be absorbed by the towns and the cities of the developing countries of Asia and Africa, directly provide us the clues to assume a much more tragic ending to this story than to the happy one. Likewise, in a situation wherein most of these countries are still severely struggling to find the proper answer to their very first initial questions of urbanization—e.g. how to provide the essential structure for their cities, define the regulation, or even design the proper pattern on how the cities should be expanded—thus it is not weird to claim that most of the coming urbanization of the world is going to happen informally. This reality could not only bring the feature, landscape or the picture of the cities of the future under the doubt but at the same time provide the ground for the rise of a bunch of other essential questions of how the facilities would be distributed in these cities, or how fair will this pattern of distribution be. Kabul the capital of Afghanistan, as a city located in the developing world that its process of urbanization has been starting since 2001 and currently hold the position to be the fifth fastest growing city in the world, contained to a considerable slum ratio of 0.7—that means about 70 percent of its population is living in the informal areas—subsequently could be a very good case study to put this questions into the research and find out how the informal development of a city can lead to the unfair and unbalanced distribution of its facilities. Likewise, in this study we tried our best to first propose the ideal model for the fair distribution of the facilities in the Kabul city—where all the citizens have the same equal chance of access to the facilities—and then evaluate the situation of the city based on how fair the facilities are currently distributed therein. We subsequently did it by the comparative analysis between the existing facility rate in the formal and informal areas of the city to the one that was proposed as the fair ideal model.Keywords: Afghanistan, facility distribution, formal settlements, informal settlements, Kabul
Procedia PDF Downloads 1115550 Removal of Na₂SO₄ by Electro-Confinement on Nanoporous Carbon Membrane
Authors: Jing Ma, Guotong Qin
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We reported electro-confinement desalination (ECMD), a desalination method combining electric field effects and confinement effects using nanoporous carbon membranes as electrode. A carbon membrane with average pore size of 8.3 nm was prepared by organic sol-gel method. The precursor of support was prepared by curing porous phenol resin tube. Resorcinol-formaldehyde sol was coated on porous tubular resin support. The membrane was obtained by carbonisation of coated support. A well-combined top layer with the thickness of 35 μm was supported by macroporous support. Measurements of molecular weight cut-off using polyethylene glycol showed the average pore size of 8.3 nm. High salt rejection can be achieved because the water molecules need not overcome high energy barriers in confined space, while huge inherent dehydration energy was required for hydrated ions to enter the nanochannels. Additionally, carbon membrane with additional electric field can be used as an integrated membrane electrode combining the effects of confinement and electric potential gradient. Such membrane electrode can repel co-ions and attract counter-ions using pressure as the driving force for mass transport. When the carbon membrane was set as cathode, the rejection of SO₄²⁻ was 94.89%, while the removal of Na⁺ was less than 20%. We set carbon membrane as anode chamber to treat the effluent water from the cathode chamber. The rejection of SO₄²⁻ and Na⁺ reached to 100% and 88.86%, respectively. ECMD will be a promising energy efficient method for salt rejection.Keywords: nanoporous carbon membrane, confined effect, electric field, desalination, membrane reactor
Procedia PDF Downloads 1195549 Lanthanum Strontium Titanate Based Anode Materials for Intermediate Temperature Solid Oxide Fuel Cells
Authors: A. Saurabh Singh, B. Raghvendra, C. Prabhakar Singh
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Solid Oxide Fuel Cells (SOFCs) are one of the most attractive electrochemical energy conversion systems, as these devices present a clean energy production, thus promising high efficiencies and low environmental impact. The electrodes are the main components that decisively control the performance of a SOFC. Conventional, anode materials (like Ni-YSZ) are operates at very high temperature. Therefore, cost-effective materials which operate at relatively lower temperatures are still required. In present study, we have synthesized La doped Strontium Titanate via solid state reaction route. The structural, microstructural and density of the pellet have been investigated employing XRD, SEM and Archimedes Principle, respectively. The electrical conductivity of the systems has been determined by impedance spectroscopy techniques. The electrical conductivity of the Lanthanum Strontium Titanate (LST) has been found to be higher than the composite Ni-YSZ system at 700 °C.Keywords: IT-SOFC, LST, Lanthanum Strontium Titanate, electrical conductivity
Procedia PDF Downloads 3775548 An Introduction to the Radiation-Thrust Based on Alpha Decay and Spontaneous Fission
Authors: Shiyi He, Yan Xia, Xiaoping Ouyang, Liang Chen, Zhongbing Zhang, Jinlu Ruan
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As the key system of the spacecraft, various propelling system have been developing rapidly, including ion thrust, laser thrust, solar sail and other micro-thrusters. However, there still are some shortages in these systems. The ion thruster requires the high-voltage or magnetic field to accelerate, resulting in extra system, heavy quantity and large volume. The laser thrust now is mostly ground-based and providing pulse thrust, restraint by the station distribution and the capacity of laser. The thrust direction of solar sail is limited to its relative position with the Sun, so it is hard to propel toward the Sun or adjust in the shadow.In this paper, a novel nuclear thruster based on alpha decay and spontaneous fission is proposed and the principle of this radiation-thrust with alpha particle has been expounded. Radioactive materials with different released energy, such as 210Po with 5.4MeV and 238Pu with 5.29MeV, attached to a metal film will provides various thrust among 0.02-5uN/cm2. With this repulsive force, radiation is able to be a power source. With the advantages of low system quantity, high accuracy and long active time, the radiation thrust is promising in the field of space debris removal, orbit control of nano-satellite array and deep space exploration. To do further study, a formula lead to the amplitude and direction of thrust by the released energy and decay coefficient is set up. With the initial formula, the alpha radiation elements with the half life period longer than a hundred days are calculated and listed. As the alpha particles emit continuously, the residual charge in metal film grows and affects the emitting energy distribution of alpha particles. With the residual charge or extra electromagnetic field, the emitting of alpha particles performs differently and is analyzed in this paper. Furthermore, three more complex situations are discussed. Radiation element generating alpha particles with several energies in different intensity, mixture of various radiation elements, and cascaded alpha decay are studied respectively. In combined way, it is more efficient and flexible to adjust the thrust amplitude. The propelling model of the spontaneous fission is similar with the one of alpha decay, which has a more complex angular distribution. A new quasi-sphere space propelling system based on the radiation-thrust has been introduced, as well as the collecting and processing system of excess charge and reaction heat. The energy and spatial angular distribution of emitting alpha particles on unit area and certain propelling system have been studied. As the alpha particles are easily losing energy and self-absorb, the distribution is not the simple stacking of each nuclide. With the change of the amplitude and angel of radiation-thrust, orbital variation strategy on space debris removal is shown and optimized.Keywords: alpha decay, angular distribution, emitting energy, orbital variation, radiation-thruster
Procedia PDF Downloads 1945547 Sustainable Integrated Waste Management System
Authors: Lidia Lombardi
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Waste management in Europe and North America is evolving towards sustainable materials management, intended as a systemic approach to using and reusing materials more productively over their entire life cycles. Various waste management strategies are prioritized and ranked from the most to the least environmentally preferred, placing emphasis on reducing, reusing, and recycling as key to sustainable materials management. However, non-recyclable materials must also be appropriately addressed, and waste-to-energy (WtE) offers a solution to manage them, especially when a WtE plant is integrated within a complex system of waste and wastewater treatment plants and potential users of the output flows. To evaluate the environmental effects of such system integration, Life Cycle Assessment (LCA) is a helpful and powerful tool. LCA has been largely applied to the waste management sector, dating back to the late 1990s, producing a large number of theoretical studies and applications to the real world as support to waste management planning. However, LCA still has a fundamental role in helping the development of waste management systems supporting decisions. Thus, LCA was applied to evaluate the environmental performances of a Municipal Solid Waste (MSW) management system, with improved separate material collection and recycling and an integrated network of treatment plants including WtE, anaerobic digestion (AD) and also wastewater treatment plant (WWTP), for a reference study case area. The proposed system was compared to the actual situation, characterized by poor recycling, large landfilling and absence of WtE. The LCA results showed that the increased recycling significantly increases the environmental performances, but there is still room for improvement through the introduction of energy recovery (especially by WtE) and through its use within the system, for instance, by feeding the heat to the AD, to sludge recovery processes and supporting the water reuse practice. WtE offers a solution to manage non-recyclable MSW and allows saving important resources (such as landfill volumes and non-renewable energy), reducing the contribution to global warming, and providing an essential contribution to fulfill the goals of really sustainable waste management.Keywords: anaerobic digestion, life cycle assessment, waste-to-energy, municipal solid waste
Procedia PDF Downloads 53