Search results for: porous metals

Authors: Khwaja Naweed Seddiqi, Zabihullah Mahdi, Shigeo Honma

Abstract:

Recently increasing oil production from petroleum reservoirs is one of the most important issues in the global energy sector. So, in this paper, the recovery of oil by the waterflooding technique from petroleum reservoir are considered. To investigate the aforementioned phenomena, the relative permeability of two immiscible fluids in sand is measured in the laboratory based on the steady-state method. Two sorts of oils, kerosene and heavy oil, and water are pumped simultaneously into a vertical sand column with different pumping ratio. From the change in fractional discharge measured at the outlet, a method for determining the relative permeability is developed focusing on the displacement mechanism in sand. Then, displacement mechanism of two immiscible fluids in the sand is investigated under the Buckley-Leveret frontal displacement theory and laboratory experiment. Two sorts of experiments, one is the displacement of pore water by oil, the other is the displacement of pore oil by water, are carried out. It is revealed that the relative permeability curves display tolerably different shape owing to the properties of oils, and produce different amount of residual oils and irreducible water saturation.

Keywords: petroleum reservoir engineering, relative permeability, two-phase flow, immiscible displacement in porous media, steady-state method, waterflooding

Procedia PDF Downloads 247

Authors: Hasan Basri Jumin

Abstract:

Fly ash sewage of pulp and paper industries when processed with suitable process and true management may possibly be used fertilizer agriculture purposes. The objective of works is to evaluate re-cycling possibility of fly ash waste to be applied as a fertilizer for agriculture use. Fly ash sewage was applied to maize with 28 g/plant could be increased significantly the average of dry weigh from dry weigh of seed increase from 6.7 g/plant into 10.3 g/plant, and net assimilation rates could be increased from 14.5 mg.m-2.day-1 into 35.4 mg.m-2 day-1. Therefore, production per hectare was reached 3.2 ton/ha. The chemical analyses of fly ash waste indicated that, there are no exceed threshold content of dangerous metals and biology effects. Mercury, arsenic, cadmium, chromium, cobalt, lead, and molybdenum contents as heavy metal are lower than the threshold of human healthy tolerance. Therefore, it has no syndrome effect to human health. This experiment indicated that fly ash sewage in lower doses until 28 g/plant could be applied as substitution fertilizer for agriculture use and it could be eliminate the environment pollution.

Keywords: fly-ash, fertilizer, maize, sludge-sewage pollutant, waste

Procedia PDF Downloads 582

Authors: M. Khallaf, R. Khalil, H. Ghetas

Abstract:

In the present study, V. harveyi and V. alginolyticus were isolated from cultured seabass and seabream at Damietta Governorate, Egypt, during summer season. Isolates were biochemically and molecularly identified using primers for Vhh and Collagenase genes. The most prominent clinical observations of diseased fish were exophthalmia, abdominal distension, and multifocal cutaneous hemorrhagic ulceration on the dorsal musculature and caudal peduncle. Physicochemical characteristics of water samples indicated that the unionized ammonia, nitrate, and hydrogen sulphate concentrations were higher than the acceptable limits. Heavy metals concentrations in water samples exhibited higher concentrations than the permissible levels for fish culture, which was considered as chemical stressors that increase the prevalence of these bacterial diseases. Immune parameters were lower in diseased seabass and seabream than apparently healthy fish. Lesions of different fish organs were identified histopathologically.

Keywords: seabass, seabream, Vibrio alginolyticus, Vibrio harveyi

Procedia PDF Downloads 117

Authors: Piotr Prewysz-Kwinto

Abstract:

A dynamic development of financial market is accompanied by the emergence of new products on stock exchanges which give absolutely new possibilities of investing money. Currently, the most innovative financial instruments offered to investors are exchange traded products (ETP). They can be defined as financial instruments whose price depends on the value of the underlying instrument. Thus, they offer investors a possibility of making a profit that results from the change in value of the underlying instrument without having to buy it. Currently, the Warsaw Stock Exchange offers many types of ETPs. They are investment products with full or partial capital protection, products without capital protection as well as leverage products, issued on such underlying instruments as indices, sector indices, commodity indices, prices of energy commodities, precious metals, agricultural produce or prices of shares of domestic and foreign companies. This paper presents the mechanism of functioning of ETP available on the Warsaw Stock Exchange and the results of the analysis of statistical data on these financial instruments.

Keywords: exchange traded products, financial market, investment, stock exchange

Procedia PDF Downloads 349

Authors: Allouache Nadia

Abstract:

Solid adsorption cooling machines have been extensively studied recently. They constitute very attractive solutions recover important amount of industrial waste heat medium temperature and to use renewable energy sources such as solar energy. The development of the technology of these machines can be carried out by experimental studies and by mathematical modelisation. This last method allows saving time and money because it is suppler to use to simulate the variation of different parameters. The adsorption cooling machines consist essentially of an evaporator, a condenser and a reactor (object of this work) containing a porous medium, which is in our case the activated carbon reacting by adsorption with ammoniac. The principle can be described as follows: When the adsorbent (at temperature T) is in exclusive contact with vapour of adsorbate (at pressure P), an amount of adsorbate is trapped inside the micro-pores in an almost liquid state. This adsorbed mass m, is a function of T and P according to a divariant equilibrium m=f (T,P). Moreover, at constant pressure, m decreases as T increases, and at constant adsorbed mass P increases with T. This makes it possible to imagine an ideal refrigerating cycle consisting of a period of heating/desorption/condensation followed by a period of cooling/adsorption/evaporation. Effect of key parameters on the machine performances are analysed and discussed.

Keywords: activated carbon-ammoniac pair, effect of key parameters, numerical modeling, solar cooling machine

Procedia PDF Downloads 255

Authors: Ashish Khanal, Suja Giri

Abstract:

The scrap collection work is associated with multiple health hazards. Cut and scratches during collection and transportation of scraps are common. IWBs purchase the scraps mainly papers, cartoons, glass bottles and metals from the households. This study was conducted in Kathmandu, the capital city of Nepal. The location was chosen because Kathmandu is the biggest city of Nepal with highest number of IWBs. The research used a case study strategy to examine the occupational health hazards of IWBs. The only mode of collecting and transporting of scraps in Kathmandu is the bicycle. They have to do this regular work even during the scorching sun and chilled winter. The musculoskeletal and gastrointestinal disorders are the common health problem shared by IWBs in Kathmandu, Nepal. Despite of these problems, IWBs don’t take it seriously and rarely goes for the health check-up. There is need of personal protective equipment and guidance for safety of IWBs. IWBs need to wear closed shoes and use gloves to avoid cuts during the collection and transportation of the recyclables.

Keywords: itinerant waste buyers, Kathmandu, occupational health, scrap

Procedia PDF Downloads 181

Authors: Lamia L. G. Al-Mahamad, Benjamin R. Horrocks, Andrew Houlton

Abstract:

Hydrogels based on metal coordination polymers of nucleosides and a range of metal ions (Au, Ag, Cu) have been prepared and characterized by atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, ultraviolet-visible absorption spectroscopy, and powder X-ray diffraction. AFM images of the xerogels revealed the formation of extremely long polymer molecules (> 10 micrometers, the maximum scan range). This result is also consistent with TEM images which show a fibrous morphology. Oxidative doping of the Au-nucleoside fibres produces an electrically conductive nanowire. No sharp Bragg peaks were found at the at the X-ray diffraction pattern for metal ions hydrogels indicating that the samples were amorphous, but instead the data showed broad peaks in the range 20 < Q < 40 and correspond to distances d=2μ/Q. The data was analysed using a simplified Rietveld method by fitting a regression model to obtain the distance between atoms.

Keywords: hydrogel, metal ions, nanowire, nucleoside

Procedia PDF Downloads 265

Authors: Esra Öztürk, Erkul Karacaoglu

Abstract:

Pyrochlores, having compounds of the general formula, A2B2O7 (A and B are metals/rare earths) are important class of materials thanks to having technological applications like in luminescence, ionic conductivity, nuclear waste immobilization etc. The rare earths included pyrochlore compounds have also potential photoluminescence characteristics. In this context, Er3+-activated Lu2Ti2O7 pyrochlore was chosen and synthesized through a high-temperature solid-state reaction route that was sintered under the open atmosphere in this study. The optimal reaction conditions to obtain expected single phase system, the thermal analysis (DTA/TG) were carried out. The X-ray powder diffraction (XRD) was used to determine phase properties of the sample. The photoluminescence (PL) results were done to obtain excitation, emission and decay time properties by a PL spectrometer under room temperature. According to the PL, there are excitation bands at 352 nm, 388 nm, 423 nm and 453 nm that are due to 4I15/2 → 2G7/2, 4I15/2 → 4G11/2 and 4I15/2 → 4F5/2 transitions of Er3+ ions, respectively. The emission bands are placed at 582 nm, 677 nm and 762 nm that are associated with 2H11/2, 4S3/2 → 4I15/2, 4F9/2 → 4I15/2, 4I9/2 → 4I15/2 transitions of Er3+ ions, respectively.

Keywords: Er3+, Lu2Ti2O7, photoluminescence, pyrochlore, rare-earths

Procedia PDF Downloads 271

Authors: B. Soni, S. Biswas

Abstract:

Metal foams of Al find diverse applications in several industrial sectors such as in automotive and sports equipment industry as impact, acoustic and vibration absorbers, the aerospace industry as structural components in turbines and spatial cones, in the naval industry as low frequency vibration absorbers, and in construction industry as sound barriers inside tunnels, as fire proof materials and structure protection systems against explosions and even in heat exchangers, orthopedic components, and decorative items. Here, we report on the development of Al foams by a low cost and convenient technique of salt replication method with efficient control over size, geometry and distribution of the pores. Sodium bicarbonate was used as the foaming agent to form the porous refractory salt pattern. The mixed refractory salt slurry was microwave dried followed by sintering for selected time periods. Molten Al was infiltrated into the salt pattern in an inert atmosphere at a pressure of 2 bars. The final products were obtained by leaching out the refractory salt pattern. Mechanical properties of the derived samples were studied with a universal testing machine. The results were analyzed in correlation with their microstructural features evaluated with a scanning electron microscope (SEM).

Keywords: metal foam, Al, salt replication method, mechanical properties, SEM

Procedia PDF Downloads 356

Authors: Sadia Ilyas, Hyunjung Kim, Rajiv R. Srivastava

Abstract:

Current work has attempted to establish the linkages between circular bio-economy and recycling of copper and gold from urban mine by applying microbial activities instead of the smelter and chemical technologies. Thereafter, based on the potential of microbial approaches and research hypothesis, the structural model has been tested for a significance level of 99%, which is supported by the corresponding standardization co-efficient values. A prediction model applied to determine the recycling impact on circular bio-economy indicates to re-circulate 51,833 tons of copper and 58 tons of gold by 2030 for the production of virgin metals/raw-materials, while recycling rate of the accumulated e-waste remains to be 20%. This restoration volume of copper and gold through the microbial activities corresponds to mitigate 174 million kg CO₂ emissions and 24 million m³ water consumption if compared with the primary production activities. The study potentially opens a new window for environmentally-friendly biotechnological recycling of e-waste urban mine under the umbrella concept of circular bio-economy.

Keywords: urban mining, biobleaching, circular bio-economy, environmental impact

Procedia PDF Downloads 158

Authors: Ali A. Mutair

Abstract:

The concentration levels of iron (Fe), copper (Cu), zinc (Zn), cadmium (Cd) and lead (Pb) in different cigarette brands commonly produced and sold in Yemen were determined. Convenient sample treatment for cigarette tobacco of freshly opened packs was achieved by a sample preparation method based on dry digestion, and the concentrations of the analysed metals were measured by Flame Atomic Absorption Spectrometry (FAAS). The mean values obtained for Fe, Zn, Cu, Cd, and Pb in different Yemeni cigarette tobacco were 311, 52.2, 10.11, 1.71 and 4.06 µg/g dry weight, respectively. There is no more significant difference among cigarette brands tested. It was found that Fe was at the highest concentration, followed by Zn, Cu, Pb and Cd. The average relative standard deviation (RSD) ranged from 1.77% to 19.34%. The accuracy and precision of the results were checked by blank and recovery tests. The results show that Yemeni cigarettes contain heavy metal concentration levels that are similar to those in foreign cigarette brands reported by other studies in the worldwide.

Keywords: iron, zinc, copper, lead, cadmium, tobacco, Yemeni cigarette brands, atomic absorption spectrometry

Procedia PDF Downloads 359

Authors: Nida Rabab

Abstract:

The present study was conducted to assess the Impact on Vegetables Irrigated with Municipal and Industrial wastewater from Korangi Drain near IoBM, Karachi. Some vegetables are grown using sewage and industrial wastewater laden with alarmingly high levels of heavy metals and bacteriological contamination. Maximum concentration of lead was found in spinach 8.20 mg/l as against safe limits of 0.01 mg/l and maximum nickel concentration was found in banana 3.114 mg/l as against 0.02 mg/l, whereas all vegetables were invariably bacteriologically contaminated much beyond safe limits. Appropriate legislations in Sindh and competent manpower for rigorous monitoring to gage the harmful impact on vegetables grown with untreated municipal and industrial wastewater to effectively combat the problems of growing vegetables. The emptying of untreated municipal and industrial wastewater through Korangi Drain in fresh water bodies into Karachi cost should be banned to save the coast becoming hypoxic causing irreparable loss to marine life.

Keywords: laden, concentration, hypoxic, vegetables

Procedia PDF Downloads 301

Authors: Shaher Bano, Samia Fida, Asif Israr

Abstract:

The synergistic effect of properties of metals and fibers reinforced laminates has diverted attention of the world towards use of robust composite materials known as fiber-metal laminates in many high performance applications. In this study, modification of an adhesively bonded joint as a single lap joint of carbon fibers based CARALL FML has done to increase interlaminar shear strength of the joint. The effect of different configurations of joint designs such as spews, stepped and modification in adhesive by addition of nano-fillers was studied. Both experimental and simulation results showed that modified joint design have superior properties as maximum force experienced stepped joint was 1.5 times more than the simple lap joint. Addition of carbon nano-tubes as nano-fillers in the adhesive joint increased the maximum force due to crack deflection mechanism.

Keywords: adhesive joint, Carbon Reinforced Aluminium Laminate (CARALL), fiber metal laminates, spews

Procedia PDF Downloads 237

Authors: A. Mavrikos, N. Petsas, E. Kaltsi, D. Kaliampakos

Abstract:

The lignite-fired power plants in the Western Macedonia Lignite Center produce more than 8 106 t of fly ash per year. Approximately 90% of this quantity is used for restoration-reclamation of exhausted open-cast lignite mines and slope stabilization of the overburden. The purpose of this work is to evaluate the environmental behavior of the mixture of waste rock and fly ash that is being used in the external deposition site of the South Field lignite mine. For this reason, a borehole was made within the site and 86 samples were taken and subjected to chemical analyses and leaching tests. The results showed very limited leaching of trace elements and heavy metals from this mixture. Moreover, when compared to the limit values set for waste acceptable in inert waste landfills, only few excesses were observed, indicating only minor risk for groundwater pollution. However, due to the complexity of both the leaching process and the contaminant pathway, more boreholes and analyses should be made in nearby locations and a systematic groundwater monitoring program should be implemented both downstream and within the external deposition site.

Keywords: co-deposition, fly ash, leaching tests, lignite, waste rock

Procedia PDF Downloads 238

Authors: Partha Pratim Kalita

Abstract:

As sound can be converted to light, light can also be deduced to sound. There are technologies to convert light to sound, but there are not many technologies related to the field where sound can be converted to a distinct vibrational sequence of light. Like the laws under which the principles of sound work, there are principles for the light to become quantum in nature. Thus, as we move from sound to the subtler aspects of light, we are moving from 3D to 5D. Either we will be making technologies of 3D in today’s world, or we will be really interested in making technologies of the 5D, depends on our understanding of how quantum 5D works. Right now, the entire world is talking about quantum, which is about the nature and behavior of subatomic particles, which is 5D. In practice, they are using metals and machines based on atomic structures. If we talk of quantum without taking note of the technologies of 5D and beyond, we will only be reinterpreting relative theories in the name of quantum. This paper, therefore, will explore the possibilities of moving towards quantum in its real essence with the Shoonya ecosystem (zero-point energy). In this context, the author shall highlight certain working models developed by him, which are currently in discussion with the Indian government.

Keywords: quantum mechanics, quantum technologies, healthcare, shoonya ecosystem, energy, human consciousness

Procedia PDF Downloads 196

Authors: Christian C. Vaso, Rinlee Butch M. Cervera

Abstract:

One of the most promising anode materials for solid oxide electrolysis cell (SOEC) application is the Sr-doped LaMnO₃ (LSM) which is known to have a high electronic conductivity but low ionic conductivity. To increase the ionic conductivity or diffusion of ions through the anode, Yttria-stabilized Zirconia (YSZ), which has good ionic conductivity, is proposed to be combined with LSM to create a composite electrode and to obtain a high mixed ionic and electronic conducting anode. In this study, composite of lanthanum strontium manganite and YSZ oxide, La_0.8Sr_0.2MnO₃/Zr_0.92Y_0.08O₂ (LSM/YSZ), with different wt.% compositions of LSM and YSZ were synthesized using solid-state reaction. The obtained prepared composite samples of 60, 50, and 40 wt.% LSM with remaining wt.% of 40, 50, and 60, respectively for YSZ were fully characterized for its microstructure by using powder X-ray diffraction (XRD), Thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and Scanning electron microscope/Energy dispersive spectroscopy (SEM/EDS) analyses. Surface morphology of the samples via SEM analysis revealed a well-sintered and densified pure LSM, while a more porous composite sample of LSM/YSZ was obtained. Electrochemical impedance measurements at intermediate temperature range (500-700 °C) of the synthesized samples were also performed which revealed that the 50 wt.% LSM with 50 wt.% YSZ (L50Y50) sample showed the highest total conductivity of 8.27x10^-1 S/cm at 600 ^oC with 0.22 eV activation energy.

Keywords: ceramics, microstructure, fuel cells, electrochemical impedance spectroscopy

Procedia PDF Downloads 250

Authors: Sathish Sundar Dhilip Kumar, Nicolette Houreld, Heidi Abrahamse

Abstract:

Silver nanoparticles (AgNPs) are classified as metal-based nanomaterials and have received considerable attention globally for wound healing and tissue engineering applications. Naturally available materials are a significant source of medicinal products to treat numerous diseases; polysaccharides are among them. Polysaccharides are non-toxic, safe, and inexpensive, and it has good biocompatibility and biodegradability. Most polysaccharides are shown to have a positive effect on wound healing processes, including chitosan and gum tragacanth. The present study evaluated the improvement of cellular wound healing by nanosilver-loaded polysaccharide-based biomaterial (CGT-NS) in WS1 cells. The physicochemical properties of prepared CGT-NS were studied using different characterization techniques, and it exhibited better stability and swelling properties in various pH conditions. Surface morphology was studied using scanning electron microscopy, and it revealed the porous morphology of the synthesized CGT-NS. The synthesized biomaterial displayed acceptable antibacterial properties against Gram-positive and Gram-negative bacterial strains, and it may prevent infection. The biocompatibility of the synthesized CGT-NS biomaterial was studied in WS1 cells, where it may lead to promote increased cell adhesion and proliferation properties. Thus, the CGT-NS biomaterial has good potential as a biomaterial in wound healing applications.

Keywords: biomaterial, wound healing, nano, silver nanoparticles

Procedia PDF Downloads 184

Authors: Sónia Ribeiro, Diana Farinha, Hélia Sales, Rita Pontes, João Nunes

Abstract:

The demand and commitment to sustainability in the agrifood sector introduce news opportunities for new composite materials. Composite materials are emerging as a vital entity for the sustainable development. Polylactic acid (PLA) has been recognized as a potential polymer with attractive characteristics for agrifood sector applications. PLA that can be beneficial for the development of composites, biocomposites, films, porous gels, and so on. The production of PLA from lignocellulosic biomass residues matrix is a key option towards a sustainable and circular bioeconomy and a non-competitive application with feed and food sector. The Flui and BeirInov projects presents news developments in the production of PLA composites to value the Portuguese forest ecosystem, with high amount of lignocellulosic biomass residues and available. A performance production of lactic acid from lignocellulosic biomass undergoes a process of autohydrolysis, saccharification and fermentation, originating a lactic acid fermentation medium with a 72.27g.L-1 was obtained and a final purification of 72%. The high purification PLA from multi lignocellulosic residues representing one economic expensive process, and a new materials and application for the polymers and a combination with others types of composites matrix characteristic is the drive-up for this green market.

Keywords: polylactic acid, lignocellulosic biomass, agrifood, composite materials

Procedia PDF Downloads 75

Authors: M. Bouhoun Ali, A. Y. Badjah Hadj Ahmed, M. Attou, A. Elias, M. A. Didi

Abstract:

In this paper, the solvent extraction of uranium(VI), plutonium(IV) and thorium(IV) from aqueous solutions using 1-hydroxyhexadecylidene-1,1-diphosphonic acid (HHDPA) in treated kerosene has been investigated. The HHDPA was previously synthesized and characterized by FT-IR, 1H NMR, 31P NMR spectroscopy and elemental analysis. The effects contact time, initial pH, initial metal concentration, aqueous/organic phase ratio, extractant concentration and temperature on the extraction process have been studied. An empirical modelling was performed by using a 25 full factorial design, and regression equation for extraction metals was determined from the data. The conventional log-log analysis of the extraction data reveals that ratios of extractant to extracted U(VI), Pu(IV) and Th(IV) are 1:1, 1:2 and 1:2, respectively. Thermodynamic parameters showed that the extraction process was exothermic heat and spontaneous. The obtained optimal parameters were applied to real effluents containing uranium(VI), plutonium(IV) and thorium(IV) ions.

Keywords: solvent extraction, uranium, plutonium, thorium, 1-hydroxyhexadecylidene-1-1-diphosphonic acid, aqueous solution

Procedia PDF Downloads 288

Authors: Khanom Simarani

Abstract:

Rice husk has been widely reported as a good sorbent for heavy metals. Pre treatment of rice husk minimizes cellulose crystallinity and increases the surface area thus ensuring better adsorption capacity. Commercial base and natural base-treated rice husk were used to investigate the potential of Ni(II) adsorption from synthetic solutions and waste water in batch systems. Effects of process variables such as pH, contact time, adsorbent dose, initial Ni (II) concentration were studied. Optimum Ni (II) adsorption was observed at pH 6 within 60 min of contact time. Experimental data showed increased amount of adsorbed Ni(II) with increasing adsorbent dose and decreased percent of adsorption with increasing initial Ni(II) concentration. Kinetic isotherms (Langmuir, Freundlich) were also applied. Biosorption mechanism of rice husk was analyzed using SEM/EDS, FT-IR, and XRD. The results revealed that natural base produced from agroindustrial waste could be used as efficient as commercial bases during pre treatment rice husk in removing Ni(II) from waste waters within 15 min.

Keywords: Nickel removal, adsorbent, heavy metal, biomass

Procedia PDF Downloads 296

Authors: Mohamed A. Hegazy

Abstract:

Most of Poly Vinyl Chloride (PVC) petrochemical companies produce huge amount of byproduct which characterized as carcinogenic liquid-wastes, insoluble in water, highly corrosive and highly offensive. This byproduct is partially use, a small part, in the production of hydrochloric acid and the huge part is a waste. Therefore, the aim of this work was to conversion of such PVC wastes, to an environmentally safe product that act as a corrosion Inhibitor for metals in ‎aqueous media and as a biocide for microorganisms. This conversion method was accomplished mainly to protect the environment and to produce high economic value-products. The conversion process was established and the final product was tested for the toxicity, water solubility in comparison to the crude product. Furthermore, the end product was tested as a corrosion inhibitor in 1M HCl and as a broad-spectrum biocide against standard microbial strains and against the environmentally isolated Sulfate-reducing bacteria (SRB) microbial community.

Keywords: PVC, surfactant, corrosion inhibitor, biocide, SRB

Procedia PDF Downloads 123

Authors: Fawaz M. Abdullah, Abdulrahman M. Al-Ahmari, Madiha Rafaqat

Abstract:

Laser ablation of any solid target in the liquid leads to fabricate nanoparticles (NPs) with metal or different compositions of materials such as metals, alloys, oxides, carbides, hydroxides. The fabrication of NPs in liquids based on laser ablation has grown up rapidly in the last decades compared to other techniques. Nowadays, laser ablation has been improved to prepare different types of NPs with special morphologies, microstructures, phases, and sizes, which can be applied in various fields. The paper reviews and highlights the different sizes, shapes and application field of nanoparticles that are produced by laser ablation under different liquids and materials. Also, the paper provides a case study for producing a titanium NPs produced by laser ablation submerged in distilled water. The size of NPs is an important parameter, especially for their usage and applications. The size and shape have been analyzed by SEM, (EDAX) was applied to evaluate the oxidation and elements of titanium NPs and the XRD was used to evaluate the phase composition and the peaks of both titanium and some element. SEM technique showed that the synthesized NPs size ranges were between 15-35 nm which can be applied in various field such as annihilator for cancerous cell etc.

Keywords: nanoparticles, laser ablation, titanium NPs, applications

Procedia PDF Downloads 140

Authors: Sneha Samal, Iva Petrikova, Bohdana Marvalova

Abstract:

Influence of grain size, shape and grain boundary diffusion at high temperature oxidation of pure metal is investigated as the function of microstructure evolution in this article. The oxidized scale depends on the geometrical parameter of the metal-scale system and grain shape, size, diffusion through boundary layers and influence of the contamination. The creation of the inner layer and the morphological structure develops from the internal stress generated during the growth of the scale. The oxidation rate depends on the cation and anion mobile transport of the metal in the inward and outward direction of the diffusion layer. Oxidation rate decreases with decreasing the grain size of the pure metal, whereas zinc deviates from this principle. A strong correlation between the surface roughness evolution, grain size, crystalline properties and oxidation mechanism of the oxidized metal was established.

Keywords: high temperature oxidation, pure metals, grain size, shape and grain boundary

Procedia PDF Downloads 497

Authors: R. Bennai, H. Ait Atmane, H. Fourne, B. Ayache

Abstract:

In this work, an analytical approach using a refined theory of hyperbolic shear deformation of a beam was developed to study the buckling of graduated sandwiches beams under different boundary conditions. The effects of transverse shear strains and the transverse normal deformation are considered. The constituent materials of the beam are supposed gradually variable depending on the height direction based on a simple power distribution law in terms of the volume fractions of the constituents; the two materials with which we worked are metals and ceramics. The core layer is taken homogeneous and made of an isotropic material; while the banks layers consist of functionally graded materials with a homogeneous fraction compared to the middle layer. In the end, illustrative examples are presented to show the effects of changes in different parameters such as (material graduation, the stretching effect of the thickness, boundary conditions and thickness ratio-length) on the vibration free of an FGM sandwich beams.

Keywords: FGM materials, refined shear deformation theory, stretching effect, buckling

Procedia PDF Downloads 178

Authors: Hua Tan, David Salamon

Abstract:

In this study, γ-Al2O3 powders doped with various amounts of iron were sintered via SPS process. Two heating modes – auto and manual mode were applied to observe the role of electrical induction on heating. Temperature, electric current, and pulse pattern were experimented with grade iron γ-Al2O3 powders. Phase transformation of γ to α -Al2O3 serves as a direct indicator of internal temperature, independently on measured outside temperature. That pulsing in SPS is also able to induce internal heating due to its strong electromagnetic field when dopants are conductive metals (e.g., iron) is proofed during SPS. Density and microstructure were investigated to explain the mechanism of induction heating. In addition, the role of electric pulsing and strong electromagnetic field on internal heating (induction heating) were compared and discussed. Internal heating by iron doping within electrically nonconductive samples is able to decrease sintering temperature and save energy, furthermore it is one explanation for unique features of this material fabrication technology.

Keywords: spark plasma sintering, induction heating, alumina, microstructure

Procedia PDF Downloads 332

Authors: Przemyslaw J. Jodlowski, Roman J. Jedrzejczyk, Damian K. Chlebda, Anna Dziedzicka, Lukasz Kuterasinski, Anna Gancarczyk, Maciej Sitarz

Abstract:

The aim of this study was to obtain highly active catalysts based on non-noble metal oxides supported on zirconia prepared via a sonochemical method. In this study, the influence of the stabilizers addition during the preparation step was checked. The final catalysts were characterized by using such characterization methods as X-ray Diffraction (XRD), nitrogen adsorption, X-ray fluorescence (XRF), scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM) and µRaman. The proposed preparation method allowed to obtain uniformly dispersed metal-oxide nanoparticles at the support’s surface. The catalytic activity of prepared catalyst samples was measured in a methane combustion reaction. The activity of the catalysts prepared by the sonochemical method was considerably higher than their counterparts prepared by the incipient wetness method.

Keywords: methane catalytic combustion, nanoparticles, non-noble metals, sonochemistry

Procedia PDF Downloads 219

Authors: Olumide A. Fafore, Khondlo Mtshali

Abstract:

The beginning of the 21st century saw the emergence of new and global threats to national and transnational security in West Africa and the Asia Pacific regions as a result of the spread of jihadist terrorism across borders, a manifestation of the rise of radical Islam. Extremist and armed Islamic movements influenced by Salafism, the Jihad in Afghanistan and the Muslim Brotherhood are prevalent in Northern Nigeria, Niger, Cameroon, Mali, Chad, Pakistan, Afghanistan, and India. Carrying out attacks across borders, including assassinations, murders, armed robberies, and kidnapping, assisted by open and porous borders and large flow of illegal immigrants across borders. This paper examines the effect of Radical Islam on Transnational security through a review of past literature and the social and security consequences on the people of the regions. Our findings indicate that the activities of armed Islamic movements such as Boko Haram, Ansaru and Al-Qaeda are having a negative impact on the economy, development, and security of the states and people of West Africa and the Asia Pacific. It stresses the importance of regional, transnational and international cooperation, as these threats to national and transnational security can no longer be solved in a national or regional framework.

Keywords: Islamic movements, jihadist terrorism, radical Islam, transnational security

Procedia PDF Downloads 165

Authors: Kuan Lun Pan, Moo Been Chang

Abstract:

Volatile organic compounds (VOCs) are one of major air contaminants, and they can react with nitrogen oxides (NOx) in atmosphere to form ozone (O3) and peroxyacetyl nitrate (PAN) with solar irradiation, leading to environmental hazards. In addition, some VOCs are toxic at low concentration levels and cause adverse effects on human health. How to effectively reduce VOCs emission has become an important issue. Thermal catalysis is regarded as an effective way for VOCs removal because it provides oxidation route to successfully convert VOCs into carbon dioxide (CO2) and water (H2O(g)). Single perovskite-type catalysts are promising for VOC removal, and they are of good potential to replace noble metals due to good activity and high thermal stability. Single perovskites can be generally described as ABO3 or A2BO4, where A-site is often a rare earth element or an alkaline. Typically, the B-site is transition metal cation (Fe, Cu, Ni, Co, or Mn). Catalytic properties of perovskites mainly rely on nature, oxidation states and arrangement of B-site cation. Interestingly, single perovskites could be further synthesized to form double perovskite-type catalysts which can simply be represented by A2B’B”O6. Likewise, A-site stands for an alkaline metal or rare earth element, and the B′ and B′′ are transition metals. Double perovskites possess unique surface properties. In structure, three-dimensional of B-site with ordered arrangement of B’O6 and B”O6 is presented alternately, and they corner-share octahedral along three directions of the crystal lattice, while cations of A-site position between the void of octahedral. It has attracted considerable attention due to specific arrangement of alternating B-site structure. Therefore, double perovskites may have more variations than single perovskites, and this greater variation may promote catalytic performance. It is expected that activity of double perovskites is higher than that of single perovskites toward VOC removal. In this study, double perovskite-type catalyst (La2CoMnO6) is prepared and evaluated for VOC removal. Also, single perovskites including LaCoO3 and LaMnO3 are tested for the comparison purpose. Toluene (C7H8) is one of the important VOCs which are commonly applied in chemical processes. In addition to its wide application, C7H8 has high toxicity at a low concentration. Therefore, C7H8 is selected as the target compound in this study. Experimental results indicate that double perovskite (La2CoMnO6) has better activity if compared with single perovskites. Especially, C7H8 can be completely oxidized to CO2 at 300oC as La2CoMnO6 is applied. Characterization of catalysts indicates that double perovskite has unique surface properties and is of higher amounts of lattice oxygen, leading to higher activity. For durability test, La2CoMnO6 maintains high C7H8 removal efficiency of 100% at 300oC and 30,000 h-1, and it also shows good resistance to CO2 (5%) and H2O(g) (5%) of gas streams tested. For various VOCs including isopropyl alcohol (C3H8O), ethanal (C2H4O), and ethylene (C2H4) tested, as high as 100% efficiency could be achieved with double perovskite-type catalyst operated at 300℃, indicating that double perovskites are promising catalysts for VOCs removal, and possible mechanisms will be elucidated in this paper.

Keywords: volatile organic compounds, Toluene (C7H8), double perovskite-type catalyst, catalysis

Procedia PDF Downloads 166

Authors: Olukunle C. Olawole, Dilip K. De, Moses Emetere, Omoje Maxwell

Abstract:

Graphene can stand very high temperature up to 4500 K in vacuum and has potential for application in thermionic energy converter. In this paper, we discuss the application of energy dynamics principles and the modified Richardson-Dushman Equation, to estimate the efficiency of solar power conversion to electrical power by a solar thermionic energy converter (STEC) containing emitter made of graphene. We present detailed simulation of power output for different solar insolation, diameter of parabolic concentrator, area of the graphene emitter (same as that of the collector), temperature of the collector, physical dimensions of the emitter-collector etc. After discussing possible methods of reduction or elimination of space charge problem using magnetic field and gate, we finally discuss relative advantages of using emitters made of graphene, carbon nanotube and metals respectively in a STEC.

Keywords: graphene, high temperature, modified Richardson-Dushman equation, solar thermionic energy converter

Procedia PDF Downloads 310

Authors: Susmita Sharma, Pankaj Pathak

Abstract:

Biosolids are by-products of municipal and industrial wastewater treatment process. The generation of the biosolids is increasing at an alarming rate due to the implementation of strict environmental legislation to improve the quality of discharges from wastewater treatment plant. As such, proper management and safe disposal of sewage sludge have become a worldwide topic of research. Biosolids, rich in organic matter and essential micro and macronutrients; can be used as a soil conditioner, to cut fertilizer costs and create favorable conditions for vegetation. However, it also contains pathogens and heavy metals which are undesirable as they are harmful to both humans and the environment. Therefore, for safe utilization of biosolids for land application purposes, categorization of the contaminant and pathogen is mandatory. In this context, biosolids collected from a wastewater treatment plant in Maharashtra are utilized to determine its physical, chemical and microbiological attributes. This study would ascertain, if the use of these materials from the specific site, are suitable for agriculture. Further, efforts have also been made to present the internationally acceptable legal standards and guidelines for biosolids management or application.

Keywords: biosolids, sewage, heavy metal, sustainable agriculture

Procedia PDF Downloads 329