Search results for: solar thermal energy

Authors: Amy Pullen, Samantha Rodrigues, David Kieser, Brian Shaw

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The aim of the study was to determine if a projectile interacting with the lungs increases the severity of injury in comparison to a projectile interacting with the ribs or intercostal muscle. This comparative study employed a 10% gelatine based model with either porcine ribs or balloons embedded to represent a lung. Four sample groups containing five samples were evaluated; these were control (plain gel), intercostal impact, rib impact, and lung impact. Two ammunition natures were evaluated at a range of 10m; these were 5.56x45mm and 7.62x51mm. Aspects of projectile behavior were quantified including exiting projectile weight, location of yawing, projectile fragmentation and distribution, location and area of the temporary cavity, permanent cavity formation, and overall energy deposition. Major findings included the cavity showing a higher percentage of the projectile weight exit the block than the intercostal and ribs, but similar to the control for the 5.56mm ammunition. However, for the 7.62mm ammunition, the lung was shown to have a higher percentage of the projectile weight exit the block than the control, intercostal and ribs. The total weight of projectile fragments as a function of penetration depth revealed large fluctuations and significant intra-group variation for both ammunition natures. Despite the lack of a clear trend, both plots show that the lung leads to greater projectile fragments exiting the model. The lung was shown to have a later center of the temporary cavity than the control, intercostal and ribs for both ammunition types. It was also shown to have a similar temporary cavity volume to the control, intercostal and ribs for the 5.56mm ammunition and a similar temporary cavity to the intercostal for the 7.62mm ammunition The lung was shown to leave a similar projectile tract than the control, intercostal and ribs for both ammunition types. It was also shown to have larger shear planes than the control and the intercostal, but similar to the ribs for the 5.56mm ammunition, whereas it was shown to have smaller shear planes than the control but similar shear planes to the intercostal and ribs for the 7.62mm ammunition. The lung was shown to have less energy deposited than the control, intercostal and ribs for both ammunition types. This comparative study provides insights into the influence of the lungs on thoracic gunshot trauma. It indicates that the lungs limits projectile deformation and causes a later onset of yawing and subsequently limits the energy deposited along the wound tract creating a deeper and smaller cavity. This suggests that lung impact creates an altered pattern of local energy deposition within the target which will affect the severity of trauma.

Keywords: ballistics, lung, trauma, wounding

Procedia PDF Downloads 174

Authors: S. Tayyebi, F. Mirjalili, H. Samadi, A. Nemati

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In this study, hydroxyapatite-Alumina nano composite powder, containing 15,20 and 25% weight percent of reinforced alumina were prepared by chemical precipitation from the reaction between calcium nitrate tetrahydrate and di-ammonium hydrogen phosphate with ratio of Ca / p = 1.67 and different percentage of aluminum nitrate nona hydrate in different pH of 9,10 and 11. The microstructure and thermal stability of samples were measured by X-ray diffraction (XRD), infrared spectroscopy (FT-IR) and transmission electron microscopy (TEM). The results showed that the presence of reinforced alumina phase reduced the degree of crystallinity of hydroxyapatite phase and increased its decomposition to tricalcium phosphate phase. Microstructural analysis showed that the hydroxyapatite-alumina nano composite powder was obtained with spherical shape and size of less than 100 nm.

Keywords: biomaterial, hydroxyapatite, alumina, nano composite, precipitation method

Procedia PDF Downloads 542

Authors: M. Martín-Morales, D. Eliche-Quesada, L. Pérez-Villarejo, M. Zamorano

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Olive oil is a product of particular importance within the Mediterranean and Spanish agricultural food system, and more specifically in Andalusia, owing to be the world's main production area. Olive oil processing generates olive stones which are dried and cleaned to remove pulp and olive stones fines to produce biofuel characterized to have high energy efficiency in combustion processes. Olive stones fine fraction is not too much appreciated as biofuel, so it is important the study of alternative solutions to be valorized. Some researchers have studied recycling different waste to produce ceramic bricks. The main objective of this study is to investigate the effects of olive stones addition on the properties of fired clay bricks for building construction. Olive stones were substituted by volume (7.5%, 15%, and 25%) to brick raw material in three different sizes (lower than 1 mm, lower than 2 mm and between 1 and 2 mm). In order to obtain comparable results, a series without olive stones was also prepared. The prepared mixtures were compacted in laboratory type extrusion under a pressure of 2.5MPa for rectangular shaped (30 mm x 60 mm x 10 mm). Dried and fired industrial conditions were applied to obtain laboratory brick samples. Mass loss after sintering, bulk density, porosity, water absorption and compressive strength of fired samples were investigated and compared with a sample manufactured without biomass. Results obtained have shown that olive stone addition decreased mechanical properties due to the increase in water absorption, although values tested satisfied the requirements in EN 772-1 about methods of test for masonry units (Part 1: Determination of compressive strength). Finally, important advantages related to the properties of bricks as well as their environmental effects could be obtained with the use of biomass studied to produce ceramic bricks. The increasing of the percentage of olive stones incorporated decreased bulk density and then increased the porosity of bricks. On the one hand, this lower density supposes a weight reduction of bricks to be transported, handled as well as the lightening of building; on the other hand, biomass in clay contributes to auto thermal combustion which involves lower fuel consumption during firing step. Consequently, the production of porous clay bricks using olive stones could reduce atmospheric emissions and improve their life cycle assessment, producing eco-friendly clay bricks.

Keywords: clay bricks, olive stones, sustainability, valorization

Procedia PDF Downloads 156

Authors: Xuguang Leng

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The crater pattern on the Moon indicates the Moon was captured by Earth in the more recent years, disproves the theory that the Moon was born as a satellite to the Earth. The Moon was tidal locked since it became the satellite of the Earth. Moon’s near side is shielded by Earth from asteroid/comet collisions, with the center of the near side most protected. Yet the crater pattern on the Moon is fairly random, with no distinguishable empty spot/strip, no distinguishable difference near side vs. far side. Were the Moon born as Earth’s satellite, there would be a clear crater free spot, or strip should the tial lock shifts over time, on the near side; and far more craters on the far side. The nonexistence of even a vague crater free spot on the near side of the Moon indicates the capture was a more recent event. Given Earth’s much larger mass and sphere size over the Moon, Earth should have collided with asteroids and comets in much higher frequency, resulting in significant mass gain over the lifespan. Earth’s larger mass and magnetic field are better at retaining water and gas from solar wind’s stripping effect, thus accelerating the mass gain. A dwarf planet Moon can be pulled closer and closer to the Earth over time as Earth’s gravity grows stronger, eventually being captured as a satellite. Given enough time, it is possible Earth’s mass would be large enough to cause the Moon to collide with Earth.

Keywords: moon, origin, crater, pattern

Procedia PDF Downloads 102

Authors: Manel Boulakoud, Abdelkader Chouaih, Fodil Hamzaoui

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In the present work we are interested in the determination of the Molecular electrostatic potential (MEP) in Z-3N(2-Ethoxyphenyl), 2-N’(2-Ethoxyphenyl) imino thiazolidin-4-one molecule by ab initio and Density Functional Theory (DFT) in the ground state. The MEP is related to the electronic density and is a very useful descriptor in understanding sites for electrophilic attack and nucleophilic reactions as well as hydrogen bonding interactions. First, geometry optimization was carried out using Hartree–Fock (HF) and DFT methods with 6-311G(d,p) basis set. In order to get more information on the molecule, its stability has been analyzed by natural bond orbital (NBO) analysis. Mulliken population analyses have been calculated. Finally, the molecular electrostatic potential (MEP) and HOMO-LUMO energy levels have been performed. The calculated HOMO and LUMO energies show also the charge transfer within the molecule. The energy gap obtained is about 4 eV which explain the stability of the studied compound. The obtained molecular electrostatic potential from the two methods confirms the nature of the electron charge transfer at the molecular shell and locate the electropositive part and the electronegative part in molecular scale of the title compound.

Keywords: DFT, ab initio, HOMO-LUMO, organic compounds

Procedia PDF Downloads 541

Authors: Abdul Hadi Bin Abdol Rahim, Alhassan Salami Tijani

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Hydrogen produced by means of polymer electrolyte membrane electrolyzer (PEME) is one of the most promising methods due to clean and renewable energy source. In the process, some energy loss due to mass transfer through a PEM is caused by diffusion, electro-osmotic drag, and the pressure difference between the cathode channel and anode channel. In PEME water molecules and ionic particles transferred between the electrodes from anode to cathode, Extensive mixing of the hydrogen and oxygen at anode channel due to gases cross-over must be avoided. In recent times the consciousness of safety issue in high pressure PEME where the oxygen mix with hydrogen at anode channel could create, explosive conditions have generated a lot of concern. In this paper, the steady state and simulation analysis of gases crossover in PEME on the temperature and pressure effect are presented. The simulations have been analysis in MATLAB based on the well-known Fick’s Law of molecular diffusion. The simulation results indicated that as temperature increases, there is a significant decrease in operating voltage.

Keywords: diffusion, gases crosover, steady state, Fick’s law

Procedia PDF Downloads 333

Authors: Idris Elfeituri

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In the current study, energy and exergy analysis of a 65 MW steam power plant was carried out. This study investigated the effect of variations of overall conductance of the super heater on the performance of an existing steam power plant located in Derna, Libya. The performance of the power plant was estimated by a mathematical modelling which considers the off-design operating conditions of each component. A fully interactive computer program based on the mass, energy and exergy balance equations has been developed. The maximum exergy destruction has been found in the steam generation unit. A 50% reduction in the design value of overall conductance of the super heater has been achieved, which accordingly decreases the amount of the net electrical power that would be generated by at least 13 MW, as well as the overall plant exergy efficiency by at least 6.4%, and at the same time that would cause an increase of the total exergy destruction by at least 14 MW. The achieved results showed that the super heater design and operating conditions play an important role on the thermodynamics performance and the fuel utilization of the power plant. Moreover, these considerations are very useful in the process of the decision that should be taken at the occasions of deciding whether to replace or renovate the super heater of the power plant.

Keywords: Exergy, Super-heater, Fouling; Steam power plant; Off-design., Fouling;, Super-heater, Steam power plant

Procedia PDF Downloads 339

Authors: Vitoldas Vaitkevičius, Evaldas Šerelis

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Silica fume, also known as microsilica (MS) or condensed silica fume is a by-product of the production of silicon metal or ferrosilicon alloys. Silica fume is one of the most effective pozzolanic additives which could be used for ultrahigh performance and other types of concrete. Despite the fact, however is not entirely clear, which amount of silica fume is most optimal for UHPC. Main objective of this experiment was to find optimal amount of silica fume for UHPC with and without thermal treatment, when different amount of quartz powder is substituted by silica fume. In this work were investigated four different composition of UHPC with different amount of silica fume. Silica fume were added 0, 10, 15 and 20% of cement (by weight) to UHPC mixture. Optimal amount of silica fume was determined by slump, viscosity, qualitative and quantitative XRD analysis and compression strength tests methods.

Keywords: compressive strength, silica fume, ultrahigh performance concrete, XRD

Procedia PDF Downloads 298

Authors: Wicleffe Musingarimi

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Currently, the rising energy demand as a result of an increase in the world’s population and the sustainable use of abundant natural resources are key issues facing many developed and developing countries including South Africa. Most of the energy to meet this growing demand comes from fossil fuel. Use of fossil fuels has led to environmental problems such air pollution, climate change, and acid rain. In addition, fossil fuels are facing continual depletion, which has led to the rise in oil prices, leading to the global economies melt down. Hence development of alternative clean and renewable energy source is a global priority. Renewable biomass from forest products, agricultural crops, and residues, as well as animal and municipal waste are promising alternatives. South Africa is one of the leading wine producers in the world; leading to a lot of winery waste (ww) being produced which can be used in anaerobic digestion (AD) to produce biogas. Biogas was produced from batch anaerobic digestion of zebra manure (zm) and batch anaerobic co-digestion of winery waste (ww) and zebra manure through water displacement. The batch digester with slurry of winery waste and zebra manure in the weight ratio of 1:2 was operated in a 1L container at 37°C for 30days. Co-digestion of winery waste and zebra manure produced higher amount of biogas as compared to zebra manure alone and winery waste alone. No biogas was produced by batch anaerobic digestion of winery waste alone. Chemical analysis of C/N ratio and total solids (TS) of zebra manure was 21.89 and 25.2 respectively. These values of C/N ratio and TS were quite high compared to values of other studied manures. Zebra manure also revealed unusually high concentration of Fe reaching 3600pm compared to other studies of manure. PCR with communal DNA of the digestate gave a positive hit for the presence of archaea species using standard archea primers; suggesting the presence of methanogens. Methanogens are key microbes in the production of biogas. Therefore, this study demonstrated the potential of zebra manure as an inoculum in the production of biogas.

Keywords: anaerobic digestion, biogas, co-digestion, methanogens

Procedia PDF Downloads 228

Authors: Aqsa Asharaf

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The current study aims to examine the physical characteristics of charge compact spheres employing anisotropic fluid under f(R, ϕ, X) modified gravity approach, exploring how this theoretical context influences their attributes and behavior. To accomplish our goal, we adopt the Spherically Symmetric (SS) space-time and, additionally, employ a specific Adler-based mode for the metric potential (gtt), which yields a broader class of solutions, Then, by making use of the Karmarkar condition, we successfully derive the other metric potential. A primary component of our current analysis is utilizing the Bardeen geometry as extrinsic space-time to determine the constant parameters of intrinsic space-time. Further, to validate the existence of Bardeen stellar spheres, we debate the behavior of physical properties and parameters such as components of pressure, energy density, anisotropy, parameters of EoS, stability and dynamical equilibrium, energy bounds, mass function, adiabatic index, compactness factor, and surface redshift. Conclusively, all the obtained results show that the system under consideration is physically stable, free from singularity, and viable models.

Keywords: cosmology, GR, Bardeen BH, modified gravities

Procedia PDF Downloads 38

Authors: Sonal Gupta, Rakhi Bansal, Javed Ali, Reema Gabrani, Shweta Dang

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Nanoemulsions (NEs) and microemulsions (MEs) have been an attractive tool for encapsulation of both hydrophilic and lipophillic actives. Both these systems are composed of oil phase, surfactant, co-surfactant and aqueous phase. Depending upon the application and intended use, both oil-in-water and water-in-oil emulsions can be designed. NEs are fabricated using high energy methods employing less percentage of surfactant as compared to MEs which are self assembled drug delivery systems. Owing to the nanometric size of the droplets these systems have been widely used to enhance solubility and bioavailability of natural as well as synthetic molecules. The aim of the present study is to assess the effect of % age of surfactants on cell viability of Vero cells (African Green Monkeys’ Kidney epithelial cells) via MTT assay. Green tea catechin (Polyphenon 60) loaded ME employing low energy vortexing and NE employing high energy ultrasonication were prepared using same excipients (labrasol as oil, cremophor EL as surfactant and glycerol as co-surfactant) however, the % age of oil and surfactant needed to prepare the ME was higher as compared to NE. These formulations along with their excipients (oilME=13.3%, SmixME=26.67%; oilNE=10%, SmixNE=13.52%) were added to Vero cells for 24 hrs. The tetrazolium dye, 3-(4,5-dimethylthia/ol-2-yl)-2,5-diphi-iiyltclrazolium bromide (MTT), is reduced by live cells and this reaction is used as the end point to evaluate the cytoxicity level of a test formulation. Results of MTT assay indicated that oil at different percentages exhibited almost equal cell viability (oilME ≅ oilNE) while surfactant mixture had a significant difference in the cell viability values (SmixME < SmixNE). Polyphenon 60 loaded ME and its PlaceboME showed higher toxicity as compared to Polyphenon 60 loaded NE and its PlaceboNE that can be attributed to the higher concentration of surfactants present in MEs. Another probable reason for high % cell viability of Polyphenon 60 loaded NE might be due to the effective release of Polyphenon 60 from NE formulation that helps in the sustenance of Vero cells.

Keywords: cell viability, microemulsion, MTT, nanoemulsion, surfactants, ultrasonication

Procedia PDF Downloads 440

Authors: Anders Schou Simonsen, Kim Sorensen, Thomas Condra

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Wet scrubbers are used for flue gas desulfurization by injecting water directly into the flue gas stream from a set of sprayers. The water droplets will flow freely inside the scrubber, and flow down along the scrubber walls as a thin wall film while reacting with the gas phase to remove SO₂. This complex multiphase phenomenon can be divided into three main contributions: the continuous gas phase, the liquid droplet phase, and the liquid wall film phase. This study proposes a complete model, where all three main contributions are taken into account and resolved using OpenFOAM for the continuous gas phase, and MATLAB for the liquid droplet and wall film phases. The 3D continuous gas phase is composed of five species: CO₂, H₂O, O₂, SO₂, and N₂, which are resolved along with momentum, energy, and turbulence. Source terms are present for four species, energy and momentum, which are affecting the steady-state solution. The liquid droplet phase experiences breakup, collisions, dynamics, internal chemistry, evaporation and condensation, species mass transfer, energy transfer and wall film interactions. Numerous sub-models have been implemented and coupled to realise the above-mentioned phenomena. The liquid wall film experiences impingement, acceleration, atomization, separation, internal chemistry, evaporation and condensation, species mass transfer, and energy transfer, which have all been resolved using numerous sub-models as well. The continuous gas phase has been coupled with the liquid phases using source terms by an approach, where the two software packages are couples using a link-structure. The complete CFD model has been verified using 16 experimental tests from an existing scrubber installation, where a gradient-based pattern search optimization algorithm has been used to tune numerous model parameters to match the experimental results. The CFD model needed to be fast for evaluation in order to apply this optimization routine, where approximately 1000 simulations were needed. The results show that the complex multiphase phenomena governing wet scrubbers can be resolved in a single model. The optimization routine was able to tune the model to accurately predict the performance of an existing installation. Furthermore, the study shows that a coupling between OpenFOAM and MATLAB is realizable, where the data and source term exchange increases the computational requirements by approximately 5%. This allows for exploiting the benefits of both software programs.

Keywords: desulfurization, discrete phase, scrubber, wall film

Procedia PDF Downloads 275

Authors: Junus Mara, Herman Parung, Jhony Tanijaya, Rudy Djamaluddin

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The purpose of this study is to determine the behavior of beam-column sub-assemblages castella due to cyclic loading. Knowing these behaviors can if be analyzed the effectiveness of the concrete filler to reduce the damage and improve capacity of beam castella. Test beam consists of beam castella fabricated from normal beam (CB), castella beams with concrete filler between the flange (CCB) and normal beam (NB) as a comparison. Results showed castella beam (CB) has the advantage to increase the flexural capacity and energy absorption respectively 100.5% and 74.3%. Besides advantages, castella beam has the disadvantage that lowering partial ductility and full ductility respectively 12.6% and 18.1%, decrease resistance ratio 29.5% and accelerate the degradation rate of stiffness ratio 31.4%. By the concrete filler between the beam flange to improve the ability of castella beam, then the beam castella have the ability to increase the flexural capacity of 184.78 %, 217.1% increase energy absorption, increase ductility partial and full ductility respectively 27.9 % and 26 %, increases resistance ratio 52.5% and slow the rate of degradation of the stiffness ratio 55.1 %.

Keywords: steel, castella, column beams, cyclic load

Procedia PDF Downloads 462

Authors: M. Nagaraja, H. M. Mahesh, K. Rajanna, M. Z. Kurian, J. Manjanna

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In recent years, composites of conjugated polymers with fullerenes (C60) has attracted considerable scientific and technological attention in the field of organic electronics because they possess a novel combination of electrical, optical, ferromagnetic, mechanical and sensor properties. These properties represent major advances in the design of organic electronic devices. With the addition of C60 in the conjugated polymer matrix, the primary photo-excitation of the conjugated polymer undergoes an ultrafast electron transfer, and it has been demonstrated that fullerene molecules may serve as efficient electron acceptors in polymeric solar cells. The present paper includes the systematic studies on the effect of electrical, structural and sensor properties of polyaniline (PANI) matrix by the presence of C60. Polyaniline-fullerene (PANI/C60) composite is prepared by the introduction of fullerene during polymerization of aniline with ammonium persulfate and dodechyl benzene sulfonic acid as oxidant and dopant respectively. FTIR spectroscopy indicated the interaction between PANI and C60. X-ray diffraction proved the formation of a PANI/C60 complex. SEM image shows the highly branched chain structure of the PANI in the presence of C60. The conductivity of the PANI/C60 was found to be more than ten orders of magnitude over the pure PANI.

Keywords: conductivity, fullerene, nanocomposite, polyaniline

Procedia PDF Downloads 219

Authors: Sirine Sayed, Mahrez Ait Mohammed, Mourad Nachtane, Abdelwahed Barkaoui, Khalid Bouziane, Mostapha Tarfaoui

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This study addresses a critical challenge in transitioning to a hydrogen-based economy by introducing and validating a one-dimensional (1D) tool for modelling hydrogen permeability through hybrid materials, focusing on tank applications. The model developed integrates rigorous experimental validation, published data, and advanced computational modelling using the PanDiffusion framework, significantly enhancing its validity and applicability. By elucidating complex interactions between material properties, storage system configurations, and operational parameters, the tool demonstrates its capability to optimize design and operational parameters in real-world scenarios, as illustrated through a case study of hydrogen leakage. This comprehensive approach to assessing hydrogen permeability contributes significantly to overcoming key barriers in hydrogen infrastructure development, potentially accelerating the widespread adoption of hydrogen technology across various industrial sectors and marking a crucial step towards a more sustainable energy future.

Keywords: hydrogen storage, composite tank, permeability modelling, PanDiffusion, energy carrier, transportation technology

Procedia PDF Downloads 23

Authors: Juan A. G. Carrio, Prasad Talluri, Sergio G. Echeverrigaray, Antonio H. Castro Neto

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Hydrogen as a fuel and environmentally pleasant energy carrier is part of this transition towards low-carbon systems. The extensive deployment of hydrogen production, purification and transport infrastructures still represents significant challenges. Independent of the production process, the hydrogen generally is mixed with light hydrocarbons and other undesirable gases that need to be removed to obtain H₂ with the required purity for end applications. In this context, membranes are one of the simplest, most attractive, sustainable, and performant technologies enabling hydrogen separation and purification. They demonstrate high separation efficiencies and low energy consumption levels in operation, which is a significant leap compared to current energy-intensive options technologies. The unique characteristics of 2D laminates have given rise to a diversity of research on their potential applications in separation systems. Specifically, it is already known in the scientific literature that graphene oxide-based membranes present the highest reported selectivity of H₂ over other gases. This work explores the potential of a new type of 2D materials-based membranes in separating H₂ from CO₂ and CH₄. We have developed nanostructured composites based on 2D materials that have been applied in the fabrication of membranes to maximise H₂ selectivity and permeability, for different gas mixtures, by adjusting the membranes' characteristics. Our proprietary technology does not depend on specific porous substrates, which allows its integration in diverse separation modules with different geometries and configurations, looking to address the technical performance required for industrial applications and economic viability. The tuning and precise control of the processing parameters allowed us to control the thicknesses of the membranes below 100 nanometres to provide high permeabilities. Our results for the selectivity of new nanostructured 2D materials-based membranes are in the range of the performance reported in the available literature around 2D materials (such as graphene oxide) applied to hydrogen purification, which validates their use as one of the most promising next-generation hydrogen separation and purification solutions.

Keywords: membranes, 2D materials, hydrogen purification, nanocomposites

Procedia PDF Downloads 141

Authors: Caiyun Liu, A. Hernandez-Manas, N. Grimi, E. Vorobiev

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Drying is one of the most used methods for food preservation, which extend shelf life of food and makes their transportation, storage and packaging easier and more economic. The commonly dried method is hot air drying. However, its disadvantages are low energy efficiency and long drying times. Because of the high temperature during the hot air drying, the undesirable changes in pigments, vitamins and flavoring agents occur which result in degradation of the quality parameters of the product. Drying process can also cause shrinkage, case hardening, dark color, browning, loss of nutrients and others. Recently, new processes were developed in order to avoid these problems. For example, the application of pulsed electric field provokes cell membrane permeabilisation, which increases the drying kinetics and moisture diffusion coefficient. Microwave drying technology has also several advantages over conventional hot air drying, such as higher drying rates and thermal efficiency, shorter drying time, significantly improved product quality and nutritional value. Rehydration kinetics of dried product is a very important characteristic of dried products. Current research has indicated that the rehydration ratio and the coefficient of rehydration are dependent on the processing conditions of drying. The present study compares the efficiency of two processes (1: room temperature air drying, 2: microwave/air drying) in terms of drying rate, product quality and rehydration ratio. In this work, potato slices (≈2.2g) with a thickness of 2 mm and diameter of 33mm were placed in the microwave chamber and dried. Drying kinetics and drying rates of different methods were determined. The process parameters included inlet air velocity (1 m/s, 1.5 m/s, 2 m/s) and microwave power (50 W, 100 W, 200 W and 250 W) were studied. The evolution of temperature during microwave drying was measured. The drying power had a strong effect on drying rate, and the microwave-air drying resulted in 93% decrease in the drying time when the air velocity was 2 m/s and the power of microwave was 250 W. Based on Lewis model, drying rate constants (kDR) were determined. It was observed an increase from kDR=0.0002 s-1 to kDR=0.0032 s-1 of air velocity of 2 m/s and microwave/air (at 2m/s and 250W) respectively. The effective moisture diffusivity was calculated by using Fick's law. The results show an increase of effective moisture diffusivity from 7.52×10-11 to 2.64×10-9 m2.s-1 for air velocity of 2 m/s and microwave/air (at 2m/s and 250W) respectively. The temperature of the potato slices increased for higher microwaves power, but decreased for higher air velocity. The rehydration ratio, defined as the weight of the the sample after rehydration per the weight of dried sample, was determined at different water temperatures (25℃, 50℃, 75℃). The rehydration ratio increased with the water temperature and reached its maximum at the following conditions: 200 W for the microwave power, 2 m/s for the air velocity and 75°C for the water temperature. The present study shows the interest of microwave drying for the food preservation.

Keywords: drying, microwave, potato, rehydration

Procedia PDF Downloads 273

Authors: U. L. Fulco, E. L. Albuquerque, José X. Lima Neto, L. R. Da Silva

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The binding of the nonsteroidal anti-inflammatory drug ibuprofen (IBU) to human serum albumin (HSA) is investigated using density functional theory (DFT) calculations within a fragmentation strategy. Crystallographic data for the IBU–HSA supramolecular complex shows that the ligand is confined to a large cavity at the subdomain IIIA and at the interface between the subdomains IIA and IIB, whose binding sites are FA3/FA4 and FA6, respectively. The interaction energy between the IBU molecule and each amino acid residue of these HSA binding pockets was calculated using the Molecular Fractionation with Conjugate Caps (MFCC) approach employing a dispersion corrected exchange–correlation functional. Our investigation shows that the total interaction energy of IBU bound to HSA at binding sites of the fatty acids FA3/FA4 (FA6) converges only for a pocket radius of at least 8.5 °A, mainly due to the action of residues Arg410, Lys414 and Ser489 (Lys351, Ser480 and Leu481) and residues in nonhydrophobic domains, namely Ile388, Phe395, Phe403, Leu407, Leu430, Val433, and Leu453 (Phe206, Ala210, Ala213, and Leu327), which is unusual. Our simulations are valuable for a better understanding of the binding mechanism of IBU to albumin and can lead to the rational design and the development of novel IBU-derived drugs with improved potency.

Keywords: ibuprofen, human serum albumin, density functional theory, binding energies

Procedia PDF Downloads 349

Authors: Juergen Orasche, Vesta Kohlmeier, George C. Dragan, Gert Jakobi, Patricia Forbes, Ralf Zimmermann

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Underground mining poses a difficult environment for both man and machines. At more than 1000 meters underneath the surface of the earth, ores and other mineral resources are still gained by conventional and motorised mining. Adding to the hazards caused by blasting and stone-chipping, the working conditions are best described by the high temperatures of 35-40°C and high humidity, at low air exchange rates. Separate ventilation shafts lead fresh air into a mine and others lead expended air back to the surface. This is essential for humans and machines working deep underground. Nevertheless, mines are widely ramified. Thus the air flow rate at the far end of a tunnel is sensed to be close to zero. In recent years, conventional mining was supplemented by mining with heavy diesel machines. These very flat machines called Load Haul Dump (LHD) vehicles accelerate and ease work in areas favourable for heavy machines. On the other hand, they emit non-filtered diesel exhaust, which constitutes an occupational hazard for the miners. Combined with a low air exchange, high humidity and inorganic dust from the mining it leads to 'black smog' underneath the earth. This work focuses on the air quality in mines employing LHDs. Therefore we performed personal sampling (samplers worn by miners during their work), stationary sampling and aethalometer (Microaeth MA200, Aethlabs) measurements in a platinum mine in around 1000 meters under the earth’s surface. We compared areas of high diesel exhaust emission with areas of conventional mining where no diesel machines were operated. For a better assessment of health risks caused by air pollution we applied a separated gas-/particle-sampling tool (or system), with first denuder section collecting intermediate VOCs. These multi-channel silicone rubber denuders are able to trap IVOCs while allowing particles ranged from 10 nm to 1 µm in diameter to be transmitted with an efficiency of nearly 100%. The second section is represented by a quartz fibre filter collecting particles and adsorbed semi-volatile organic compounds (SVOC). The third part is a graphitized carbon black adsorber – collecting the SVOCs that evaporate from the filter. The compounds collected on these three sections were analyzed in our labs with different thermal desorption techniques coupled with gas chromatography and mass spectrometry (GC-MS). VOCs and IVOCs were measured with a Shimadzu Thermal Desorption Unit (TD20, Shimadzu, Japan) coupled to a GCMS-System QP 2010 Ultra with a quadrupole mass spectrometer (Shimadzu). The GC was equipped with a 30m, BP-20 wax column (0.25mm ID, 0.25µm film) from SGE (Australia). Filters were analyzed with In-situ derivatization thermal desorption gas chromatography time-of-flight-mass spectrometry (IDTD-GC-TOF-MS). The IDTD unit is a modified GL sciences Optic 3 system (GL Sciences, Netherlands). The results showed black carbon concentrations measured with the portable aethalometers up to several mg per m³. The organic chemistry was dominated by very high concentrations of alkanes. Typical diesel engine exhaust markers like alkylated polycyclic aromatic hydrocarbons were detected as well as typical lubrication oil markers like hopanes.

Keywords: diesel emission, personal sampling, aethalometer, mining

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Authors: Amit Kumar Haldar, Mark Simms, Ian McDevitt, Anthony Comer

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Interface properties of fiber metal laminates (FML) affects the integrity and deformation failure modes. In this paper, the mechanical behaviours of Ti/GFRP/Ti laminates were experimentally investigated through low-velocity impact tests. Two different surface treatments of Titanium (Ti-6Al-4V) alloy sheets were prepared to obtain the composite interface properties based on annealing and sandblast surface treatment processes. The deformation failure modes, impact load sustaining ability and energy absorption capacity of FMLs were analysed. The impact load and modulus were shown to be dependent on the surface treatments of Titanium (Ti-6Al-4V) alloy sheets. It was demonstrated that the impact load performance was enhanced when titanium surfaces were annealed and sandblasted. It has also been shown that the values of the strength and energy absorption were slightly higher when the tests conducted at relatively higher loading rate, as a result of the rate-sensitive effects on the damage resistance of the FML.

Keywords: fiber metal laminates, metal composite interface, indentation, low velocity impact

Procedia PDF Downloads 201

Authors: Tawfiq Albishri, Abdulmajeed Alqahtani

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Battery electric vehicles (BEVs) are increasingly seen as a sustainable alternative to internal combustion engine (ICE) vehicles, primarily due to their environmental and economic benefits. Saudi Arabia's interest in investing in renewable energy and reducing greenhouse gas emissions presents significant potential for the widespread adoption of BEVs in the country. However, several factors have hindered the adoption of BEVs in Saudi Arabia, with high ownership costs being the most prominent barrier. This cost discrepancy is primarily due to the lack of localized production of BEVs and their components, leading to increased import costs, as well as the high initial cost of BEVs compared to ICE vehicles. This paper aims to evaluate the feasibility of BEVs compared to ICE vehicles in Saudi Arabia by conducting a cost of ownership analysis. Furthermore, a sensitivity analysis will be conducted to determine the most significant contributor to the ownership costs of BEVs that, if changed, could expedite their adoption in Saudi Arabia.

Keywords: battery electric vehicles, internal combustion engine, renewable energy, greenhouse gas emissions, total cost of ownership

Procedia PDF Downloads 89

Authors: Brahim Mazian, Anne Bergeret, Jean-Charles Benezet, Sandrine Bayle, Luc Malhautier

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Hemp fibers are increasingly used as reinforcements in polymer matrix composites due to their competitive performance (low density, mechanical properties and biodegradability) compared to conventional fibres such as glass fibers. However, the huge variation of their biochemical, physical and mechanical properties limits the use of these natural fibres in structural applications when high consistency and homogeneity are required. In the hemp industry, traditional processes termed field retting are commonly used to facilitate the extraction and separation of stem fibers. This retting treatment consists to spread out the stems on the ground for a duration ranging from a few days to several weeks. Microorganisms (fungi and bacteria) grow on the stem surface and produce enzymes that degrade pectinolytic substances in the middle lamellae surrounding the fibers. This operation depends on the weather conditions and is currently carried out very empirically in the fields so that a large variability in the hemp fibers quality (mechanical properties, color, morphology, chemical composition…) is resulting. Nonetheless, if controlled, retting might be favorable for good properties of hemp fibers and then of hemp fibers reinforced composites. Therefore, the present study aims to investigate the influence of controlled retting within a designed environmental chamber (lab-scale pilot unit) on the quality of the hemp fibres harvested at the seed maturity growth stage. Various assessments were applied directly on fibers: color observations, morphological (optical microscope), surface (ESEM), biochemical (gravimetry) analysis, spectrocolorimetric measurements (pectins content), thermogravimetric analysis (TGA) and tensile testing. The results reveal that controlled retting leads to a rapid change of color from yellow to dark grey due to development of microbial communities (fungi and bacteria) at the stem surface. An increase of thermal stability of fibres due to the removal of non-cellulosic components along retting is also observed. A separation of bast fibers to elementary fibers occurred with an evolution of chemical composition (degradation of pectins) and a rapid decrease in tensile properties (380MPa to 170MPa after 3 weeks) due to accelerated retting process. The influence of controlled retting on the biocomposite material (PP / hemp fibers) properties is under investigation.

Keywords: controlled retting, hemp fibre, mechanical properties, thermal stability

Procedia PDF Downloads 158

Authors: Navid Zanganeh, Hafez Balavi, Farbod Sharif, Mahla Zabet, Marzieh Bakhtiary Noodeh

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Cerium oxide (CeO2) also known as cerium dioxide or ceria is a pale yellow-white powder with various applications in the industry from wood coating to cosmetics, filtration, fuel cell electrolytes, gas sensors, hybrid solar cells and catalysts. In this research, attempts were made to synthesize and characterization of CeO2 nano-particles via sol-gel method. In addition, the effect of aging time on the size of particles was investigated. For this purpose, the aging times adjusted 48, 56, 64, and 72 min. The obtained particles were characterized by x-ray diffraction spectroscopy (XRD), scanning electron microscopy (SEM), transmitted electron microscopy (TEM), and Brunauer–Emmett–Teller (BET). As a result, XRD patterns confirmed the formation of CeO2 nanoparticles. SEM and TEM images illustrated the nano-particles with cluster shape, spherical and a nano-size range which was in agreement with XRD results. The finest particles (7.3 nm) was obtained at the optimum condition which was aging time of 48 min, calcination temperature at 400 ⁰C, and cerium concentration of 0.004 mol. Average specific surface area of the particles at optimum condition was measured by BET analysis and recorded as 47.57 m2/g.

Keywords: aging time, CeO2 nanoparticles, size distribution, sol-gel

Procedia PDF Downloads 463

Authors: Abdallah Sofiane Berrouk, Dara Satyadileep

Abstract:

This paper investigates the feasibility of retrofitting a middle-east based commercial amine sweetening unit with a split-flow scheme which involves withdrawing a portion of partially stripped semi-lean solvent from the stripping column and re-injecting it in the absorption column to reduce the overall energy consumption of the unit. This method is comprehensively explored by performing parametric analysis of the split fraction of the semi-lean solvent using a kinetics based process simulator ProMax V 3.2. Re-boiler duty, condenser duty, solvent cooling and pumping loads are analysed as functions of a split fraction of the semi-lean solvent from the stripper. It is shown that the proposed method significantly reduces the overall energy consumption of the unit resulting in an annual savings of 325,000 USD. The thorough economic analysis is performed using Aspen Economic Evaluation V 8.4 to reveal that the retrofit scheme pays back the capital cost in less than eight years and is highly recommended for any commercial plant having suitable provisions for solvent inlet/withdrawal on the columns.

Keywords: split flow, Amine, gas processing, optimization

Procedia PDF Downloads 335

Authors: Danuta Barnat-Hunek

Abstract:

The studies are devoted to assessing the effectiveness of hydrophobic and air entraining admixtures based on organ silicon compounds. Mortars with lightweight aggregate–perlite were the subjects of the investigation. The following laboratory tests were performed: density, open porosity, total porosity, absorptivity, capability to diffuse water vapour, compressive strength, flexural strength, frost resistance, sodium sulphate corrosion resistance and the thermal conductivity coefficient. The composition of the two mixtures of mortars was prepared: mortars without a hydrophobic admixture and mortars with cementitious waterproofing material. Surface hydrophobisation was produced on the mortars without a hydrophobic admixture using a methyl silicone resin, a water-based emulsion of methyl silicone resin in potassium hydroxide and alkyl-alkoxy-silane in organic solvents. The results of the effectiveness of hydrophobisation of mortars are the following: The highest absorption after 14 days of testing was shown by mortar without an agent (57.5%), while the lowest absorption was demonstrated by the mortar with methyl silicone resin (52.7%). After 14 days in water the hydrophobisation treatment of the samples proved to be ineffective. The hydrophobised mortars are characterized by an insignificant mass change due to freezing and thawing processes in the case of the methyl silicone resin – 1%, samples without hydrophobisation –5%. This agent efficiently protected the mortars against frost corrosion. The standard samples showed very good resistance to the pressure of sodium sulphate crystallization. Organosilicon compounds have a negative influence on the chemical resistance (weight loss about 7%). The mass loss of non-hydrophobic mortar was 2 times lower than mortar with the hydrophobic admixture. Hydrophobic and aeration admixtures significantly affect the thermal conductivity and the difference is mainly due to the difference in porosity of the compared materials. Hydrophobisation of the mortar mass slightly decreased the porosity of the mortar, and thus in an increase of 20% of its compressive strength. The admixture adversely affected the ability of the hydrophobic mortar – it achieved the opposite effect. As a result of hydrophobising the mass, the mortar samples decreased in density and had improved wettability. Poor protection of the mortar surface is probably due to the short time of saturating the sample in the preparation. The mortars were characterized by high porosity (65%) and water absorption (57.5%), so in order to achieve better efficiency, extending the time of hydrophobisation would be advisable. The highest efficiency was obtained for the surface hydrophobised with the methyl silicone resin.

Keywords: hydrophobisation, mortars, salt crystallization, frost resistance

Procedia PDF Downloads 213

Authors: M. Varmaziar

Abstract:

Magnesium (Mg) is an essential mineral that plays a crucial role in the human body. Certain types of foods, including nuts, grains, fruits, vegetables, and whole grains, are rich sources of magnesium. Mg serves as an essential cofactor for numerous enzymatic reactions, including energy metabolism, cellular growth, glycolysis, and protein synthesis. The Mg-ATP complex serves as an energy source and is vital for many physiological functions, including nerve conduction, muscle contraction, and blood pressure regulation. Despite the vital role of magnesium in energy metabolism, maintaining adequate magnesium intake is often overlooked among the general population and athletes. The aim of this study was to investigate the effect of magnesium supplementation on the physical activities of field athletes. Field athletes were divided into two groups: those who consumed magnesium supplements and those who received a placebo. These two groups received either 500 mg of magnesium oxide or a placebo daily for 8 weeks. At the beginning and end of the study, athletes completed ISI questionnaires and physical activity assessments. Nutritional analyses were performed using N4 software, and statistical analyses were conducted using SPSS19 software. The results of this study revealed a significant difference between the two study groups. Athletes who received magnesium supplements experienced less fatigue related to field athletic activities and muscle soreness. In contrast, athletes who received the placebo reported more significant fatigue and muscle soreness. A concerning finding in these results is that the performance of athletic activities may be at risk with low magnesium levels. Therefore, magnesium is essential for maintaining health and plays a crucial role in athletic performance. Consuming a variety of magnesium-rich foods ensures that individuals receive an adequate amount of this essential nutrient in their diet. The consumption of these foods improves performance parameters in athletic exercises.

Keywords: athletic performance, effect, field athletes, magnesium supplement

Procedia PDF Downloads 85

Authors: C. S. Paglia, E. Ginercordero, A. Jornet

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Environmental pollution, along with the depletion of natural resources, is among the most serious global challenges in our times. The construction industry is one of the sectors where a relevant reduction of the environmental impact can be achieved. Thus, the cement production will play a key role in sustainability, by reducing the CO₂ emissions and energy consumption and by increasing the durability of the structures. A large number of investigations have been carried out on blended cements, but it exists a lack of information on the Portland cement limestone - silica fume system. Mortar blends are optimized in the mix proportions for the different ingredients, in particular for the dosage of the silica fume. Portland cement and the new binder-based systems are compared with respect to the fresh mortar properties, the mechanical and the durability behaviour of the hardened specimens at 28 and 90 days. The use of this new binder combination exhibits an interesting hydration development with time and maintain the conventional characteristics of Portland cementitious material. On the other hand, it will be necessary to reproduce the Portland Limestone Cement-silica fume system within the concrete. A reduction of the CO₂ production, energy consumption, and a reasonable service life of the concrete structures, including a maintenance free period, will all contribute to a better environment.

Keywords: binder, cement, limestone, silica fume

Procedia PDF Downloads 121

Authors: Perla Elizabeth Jimarez Rocha, Carolina Daniela Tejeda Franco, Arturo Minor Martínez, Annel Gomez Coello

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One of the biggest problems in developing new therapies for the management and treatment of voice disorders is the difficulty of objectively evaluating the results of each treatment. A system was proposed that captures and records voice signals, in addition to analyzing the vocal quality (fundamental frequency, zero crossings, energy, and amplitude spectrum), as well as the subglottic pressure (cm H2O) during the sustained phonation of the vowel / a /; a recording system is implemented, as well as an interactive system that records information on subglottic pressure. In Mexico City, a control group of 31 patients with phoniatric pathology is proposed; non-invasive tests were performed for these most common vocal pathologies (Nodules, Polyps, Irritative Laryngitis, Ventricular Dysphonia, Laryngeal Cancer, Dysphonia, and Dysphagia). The most common pathology was irritative laryngitis (32%), followed by vocal fold paralysis (unilateral and bilateral,19.4 %). We take into consideration men and women in the pathological groups due to the physiological difference. They were separated in gender by the difference in the morphology of the respiratory tract.

Keywords: amplitude spectrum, energy, fundamental frequency, subglottic pressure, zero crossings

Procedia PDF Downloads 125

Authors: Mahmoud Hassan Onsa, Saadelnour Abdueljabbar Adam

Abstract:

Wastes from slaughterhouses in most towns in Sudan are often poorly managed and sometimes discharged into adjoining streams due to poor implementation of standards, thus causing environmental and public health hazards and also there is a large amount of manure from dairy farms. This paper presents solution of organic waste from cow dairy farms and slaughterhouse the anaerobic digestion and biogas production. The paper presents the findings of experimental investigation of biogas production with and without pasteurization using cow manure, blood and rumen content were mixed at two proportions, 72.3% manure, 21.7%, rumen content and 6% blood for bio digester1with 62% dry matter at the beginning and without pasteurization and 72.3% manure, 21.7%, rumen content and 6% blood for bio-digester2 with 10% dry matter and pasteurization. The paper analyses the quantitative and qualitative composition of biogas: gas content, the concentration of methane. The highest biogas output 2.9 mL/g dry matter/day (from bio-digester2) together with a high quality biogas of 87.4% methane content which is useful for combustion and energy production and healthy bio-fertilizer but biodigester1 gave 1.68 mL/g dry matter/day with methane content 85% which is useful for combustion, energy production and can be considered as new technology of dryer bio-digesters.

Keywords: anaerobic digestion, bio-digester, blood, cow manure, rumen content

Procedia PDF Downloads 734

Authors: Şafak Aksoy, Ali Kurşun, Erhan Çetin, Mustafa Reşit Haboğlu

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In this study, thermo elastic stress analysis is performed on a cylinder made of laminated isotropic materials under thermomechanical loads. Laminated cylinders have many applications such as aerospace, automotive and nuclear plant in the industry. These cylinders generally performed under thermomechanical loads. Stress and displacement distribution of the laminated cylinders are determined using by analytical method both thermal and mechanical loads. Based on the results, materials combination plays an important role on the stresses distribution along the radius. Variation of the stresses and displacements along the radius are presented as graphs. Calculations program are prepared using MATLAB® by authors.

Keywords: isotropic materials, laminated cylinders, thermoelastic stress, thermomechanical load

Procedia PDF Downloads 418