Search results for: chips limit temperature

Authors: Fahad Al-Mufadi, F. Djavanroodi

Abstract:

Ultrafine grained (UFG) and nanostructured (NS) materials have experienced a rapid development during the last decade and made profound impact on every field of materials science and engineering. The present work has been undertaken to develop ultra-fine grained pure copper by severe plastic deformation method and to examine the impact property by different characterizing tools. For this aim, equal channel angular pressing die with the channel angle, outer corner angle and channel diameter of 90°, 17° and 20 mm had been designed and manufactured. Commercial pure copper billets were ECAPed up to four passes by route BC at the ambient temperature. The results indicated that there is a great improvement at the hardness measurement, yield strength and ultimate tensile strength after ECAP process. It is found that the magnitudes of HV reach 136HV from 52HV after the final pass. Also, about 285% and 125% enhancement at the YS and UTS values have been obtained after the fourth pass as compared to the as-received conditions, respectively. On the other hand, the elongation to failure and impact energy have been reduced by imposing ECAP process and pass numbers. It is needed to say that about 56% reduction in the impact energy have been attained for the samples as contrasted to annealed specimens.

Keywords: SPD, ECAP, pure cu, impact property

Procedia PDF Downloads 258

Authors: Tarikayehu Amanuel, Abraham Mohammed

Abstract:

The production of biodiesel from waste materials is becoming an increasingly important research area in the field of renewable energy. One potential waste material source is avocado, a fruit with a large seed and peel that are typically discarded after consumption. This research aims to investigate the feasibility of using avocado waste as a feedstock for the production of biodiesel. The study focuses on extracting oil from the waste material using the transesterification technique and then characterizing the properties of oil to determine its suitability for conversion to biodiesel. The study was conducted experimentally, and a maximum oil yield of 11.583% (150g of oil produced from 1.295kg of avocado waste powder) was obtained from avocado waste powder at an extraction time of 4hr. An 87% fatty acid methyl ester (biodiesel) conversion was also obtained using a methanol/oil ratio of 6:1, 1.3g NaOH, reaction time 60min, and 65°C reaction temperature. Furthermore, from 145 ml of avocado waste oil, 126.15 ml of biodiesel was produced, indicating a high percentage of conversion (87%). Conclusively, the produced biodiesel showed comparable physical and chemical characteristics to that of standard biodiesel samples considered for the study. The results of this research could help to identify a new source of biofuel production while also addressing the issue of waste disposal in the food industry.

Keywords: biodiesel, avocado, transesterification, soxhlet extraction

Procedia PDF Downloads 68

Authors: Hossein Shokouhmand, Masoomeh Shadab, Rohallah Torabi

Abstract:

Turbulent flow inside the seal chamber of a pump operating at nearly high Reynolds number is investigated. A comparison of a 3-D computational model for flow and thermal analysis of a mechanical seal with experimental thermal results is presented. The computational model adequately predicts the flow field in the seal chamber and thermal characteristics with the rotating and stationary rings and the twister flow around the seal parts by solving N-S and energy equations in ANSYS-CFX software. The Reynolds stress model (RSM) is applied as a turbulence model for this purpose. Experimental work is discussed which quantifies the temperature of five different points of the working fluid in chamber, mass flow at inlet and the fluid pressure at inlet and outlet. Experimental measurements are combined with computational modeling to obtain local and average heat transfer characteristics. Numerical results of three cases including different flush rates are reported.

Keywords: mechanical seal, CFD_CFX, reynolds stress model, flow field, heat transfer analysis, stream line, heat transfer coefficient, heat flux, nusselt

Procedia PDF Downloads 439

Authors: Obradith Caicedo, Paola Devia

Abstract:

Methylene blue (MB) and malachite green (MG) are substances commonly used in classrooms for academic purposes. Nevertheless, in most cases, there is no adequate disposal of this type of waste, their presence in the environment affects ecosystems due to the presence of color and the reduction of photosynthetic processes. In this work, we evaluated properties of fibers of Luffa cylindrica in removal from dyes of aqueous solutions through an adsorption process. The point of zero charge, acid and basic sites was also investigated. The best conditions of the adsorption process were determined under a discontinuous system, evaluating an interval of the variables 2 3 : pH value, particle size of the adsorbent and contact time. The temperature (18ºC), agitation (220 rpm) and adsorbent dosage (10g/L) were constant. Measurements were made using UV- Visible spectrophotometry. The point of zero charge for Luffa cylindrica was 4,3. The number of acidic and basic sites was 2.441 meq/g and 1,009 meq/g respectively. These indicate a prevalence of acid groups. The maximum dye sorption was found to be at a pH of 5,5 (97,1 % for MB) and 5,0 (97,7% for MG) and particle size of the adsorbent 850 µm. The equilibrium uptake was attained within 60 min. With this study, it has been shown that Luffa cylindrica can be used as efficient adsorbent for the removal of methylene blue, and malachite green from aqueous solution in classrooms.

Keywords: adsorption, dye removal, low-cost adsorbents, Luffa cylindrical

Procedia PDF Downloads 188

Authors: Victor Arokia Doss, Kuberapandian Dharaniyambigai, K. Julia Rose Mary

Abstract:

Advanced Glycation End (AGE) products are the end products due to the reaction between excess reducing sugar present in diabetes and free amino group in protein lipids and nucleic acids. Thus, non-enzymic glycation of molecules such as hemoglobin, collagen, and other structurally and functionally important proteins add to the pathogenic complications such as diabetic retinopathy, neuropathy, nephropathy, vascular changes, atherosclerosis, Alzheimer's disease, rheumatoid arthritis, and chronic heart failure. The most common non-cross linking AGE, carboxymethyl lysine (CML) is formed by the oxidative breakdown of fructosyllysine, which is a product of glucose and lysine. CML is formed in a wide variety of tissues and is an index to assess the extent of glycoxidative damage. Thus we have constructed a mathematical and computational model that predicts the effect of temperature differences in vivo, on the formation of CML, which is now being considered as an important intracellular milieu. This hybrid model that had been tested for its parameter fitting and its sensitivity with available experimental data paves the way for designing novel laboratory experiments that would throw more light on the pathological formation of AGE adducts and in the pathophysiology of diabetic complications.

Keywords: advanced glycation end-products, CML, mathematical model, computational model

Procedia PDF Downloads 128

Authors: Joe Kallas

Abstract:

It is now widely accepted that the preservation of cultural heritage must go beyond simple restoration and renovation actions. While some historic monuments have been preserved for millennia, many of them, less important or simply neglected because of lack of money, have disappeared. As a result, the adaptation of monuments and archaeological sites to new functions allow them to 'survive'. Temporary activities or 'ephemeral' re-use, are increasingly recognized as a means of vitalization of deprived areas and enhancement of historic sites that became obsolete. They have the potential to increase economic and cultural value while making the best use of existing resources. However, there are often conservation and preservation issues related to the implementation of this type of re-use, which can also threaten the integrity and authenticity of archaeological sites and monuments if they have not been properly managed. This paper aims to get a better knowledge of the ephemeral re-use of heritage, and more specifically the subject of the incorporation of the festival phenomenon within the monuments and archaeological sites in Lebanon, a topic that is not yet studied enough. This paper tried to determine the elements that compose it, in order to analyze this phenomenon and to trace its good practices, by comparing international study cases to important national cases: the International Festival of Baalbek, the International Festival of Byblos and the International Festival of Beiteddine. Various factors have been studied and analyzed in order to best respond to the main problematic of this paper: 'How can we preserve the integrity of sites and monuments after the integration of an ephemeral function? And what are the preventive conservation measures to be taken when holding festivals in archaeological sites with fragile structures?' The impacts of the technical problems were first analyzed using various data and more particularly the effects of mass tourism, the integration of temporary installations, sound vibrations, the effects of unstudied lighting, until the mystification of heritage. Unfortunately, the DGA (General Direction of Antiquities in Lebanon) does not specify any frequency limit for the sound vibrations emitted by the speakers during musical festivals. In addition, there is no requirement from its part regarding the installations of the lighting systems in the historic monuments and no monitoring is done in situ, due to the lack of awareness of the impact that could be generated by such interventions, and due to the lack of materials and tools needed for the monitoring process. The study and analysis of the various data mentioned above led us to the elaboration of the main objective of this paper, which is the establishment of a list of recommendations. This list enables to define various preventive conservation measures to be taken during the holding of the festivals within the cultural heritage sites in Lebanon. We strongly hope that this paper will be an awareness document to start taking into consideration several factors previously neglected, in order to improve the conservation practices in the archaeological sites and monuments during the incorporation of the festival phenomenon.

Keywords: archaeology, authenticity, conservation, cultural heritage, festival, historic sites, integrity, monuments, tourism

Procedia PDF Downloads 117

Authors: Somayeh Azizi, Mohammad Hossein Ehsani, Amir Zareidoost

Abstract:

In this research, a technique has been developed to reduce the corrosion rate of magnesium (Mg) metal by creating Zr-Nb thin film coatings. In this regard, thin-film coatings of niobium (Nb) zirconium (Zr) double alloy are applied on pure Mg specimens under different processes conditions, such as the change of the substrate temperature, substrate bias, and coating thickness using the magnetron sputtering method. Then, deposited coatings are analyzed in terms of surface features via field-emission scanning electron microscopy (FE-SEM), thin-layer X-ray diffraction (GI-XRD), energy-dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and corrosion tests. Also, nano-scratch tests were carried out to investigate the adhesion of the thin film. The results showed that the (Zr-Nb) thin films could control the degradation rate of Mg in the simulated body fluid (SBF). The nano-scratch studies depicted that the (Zr-Nb) thin films have a proper adhesion with the Mg substrate. Therefore, this technique could be used to enhance the corrosion resistance of bare Mg and could result in improving the performance of the biodegradable Mg implant for orthopedic applications.

Keywords: (Zr-Nb) thin film, magnetron sputtering, biodegradable Mg, degradation rate

Procedia PDF Downloads 119

Authors: M. Sneha Reddy, M. Arun Kumar, V. Kameswara Rao

Abstract:

Chromites are binary transition metal oxides with a general formula of ACr₂O₄, where A = Mn²⁺, Fe²⁺, Co²⁺, Ni²⁺, and Cu²⁺. Chromites have a normal-type spinel structure with interesting applications in the areas of applied physics, material sciences, and geophysics. They have attracted great consideration because of their unique physicochemical properties and tremendous technological applications in nanodevices, sensor elements, and high-temperature ceramics with useful optical properties. Copper chromite is one of the most efficient spinel oxides, having pronounced commercial application as a catalyst in various chemical reactions like oxidation, hydrogenation, alkylation, dehydrogenation, decomposition of organic compounds, and hydrogen production. Apart from its usage in chemical industries, CuCr₂O₄ finds its major application as a burn rate modifier in solid propellant processing for space launch vehicles globally. Herein we synthesized the nanoparticles of copper chromite using the co-precipitation method. The synthesized nanoparticles were characterized by XRD, TEM, SEM, BET, and TG-DTA. The synthesized nanoparticles of copper chromites were used as a catalyst for the thermal decomposition of various high-energy materials.

Keywords: copper chromite, coprecipitation method, high energy materials, catalytic thermal decomposition

Procedia PDF Downloads 73

Authors: Emi Yuda, Yutaka Yoshida, Junichiro Hayano

Abstract:

Distinct circadian rhythm of activity, i.e., high activity during the day and deep rest at night are a typical feature of a healthy lifestyle. Exposure to the skylight is thought to be an important factor to increase arousal level and maintain normal circadian rhythm. To examine whether sunshine hours influence the day-night contract of activity, we analyzed the relationship between 24-hour heart rate (HR) and weather data of the recording day. We analyzed data in 36,500 males and 49,854 females of Allostatic State Mapping by Ambulatory ECG Repository (ALLSTAR) database in Japan. Median (IQR) sunshine duration was 5.3 (2.8-7.9) hr. While sunshine hours had only modest effects of increasing 24-hour average HR in either gender (P=0.0282 and 0.0248 for male and female) and no significant effects on nighttime HR in either gender, it increased daytime HR (P = 0.0007 and 0.0015) and day-night HF difference in both genders (P < 0.0001 for both) even after adjusting for the effects of average temperature, atmospheric pressure, and humidity. Our observations support for the hypothesis that longer sunshine hours enhance circadian rhythm of activity.

Keywords: big data, circadian rhythm, heart rate, sunshine

Procedia PDF Downloads 161

Authors: Carlos A. Domínguez Torres, Antonio Domínguez Delgado

Abstract:

In this work we study the thermodynamic behavior of some ventilated facades under summer operating conditions in Southern Spain. Under these climatic conditions, indoor comfort implies a high energetic demand due to high temperatures that usually are reached in this season in the considered geographical area. The aim of this work is to determine if during summer operating conditions in Southern Spain, ventilated façades provide some energy saving compared to the non-ventilated façades and to deduce their behavior patterns in terms of energy efficiency. The modeling of the air flow in the channel has been performed by using Navier-Stokes equations for thermodynamic flows. Numerical simulations have been carried out with a 2D Finite Element approach. This way, we analyze the behavior of ventilated façades under different weather conditions as variable wind, variable temperature and different levels of solar irradiation. CFD computations show that the combined effect of the shading of the external wall and the ventilation by the natural convection into the air gap achieve a reduction of the heat load during the summer period. This reduction has been evaluated by comparing the thermodynamic performances of two ventilated and two unventilated façades with the same geometry and thermophysical characteristics.

Keywords: passive cooling, ventilated façades, energy-efficient building, CFD, FEM

Procedia PDF Downloads 354

Authors: Madhan Vinu, Yue-Chun Jiang, Yi-Feng Lin, Chia-Her Lin

Abstract:

An effective approach to enhance the ethanol/water pervaporation of mixed matrix membranes prepared from three microporous aluminium based metal-organic frameworks (MOFs), [Al(OH)(BPDC)] (DUT-5), [Al(OH)(NDC)] (DUT-4) and [Al(OH)(BzPDC)] (CAU-8) have been synthesized by employing solvothermal reactions. Interestingly, all Al-MOFs showed attractive surface area with microporous 12.3, 10.2 and 8.0 Å for DUT-5, DUT-4 and CAU-8 MOFs which are confirmed through N₂ gas sorption measurements. All the microporous compounds are highly stable as confirmed by thermogravimetric analysis and temperature-dependent powder X-ray diffraction measurements. Furthermore, the synthesized microporous MOF particles of DUT-5, DUT-4, and CAU-8 were successfully incorporated into biological chitosan (CS) membranes to form DUT-5@CS, DUT-4@CS, and CAU-8@CS membranes. The different MOF loadings such as 0.1, 0.15, and 0.2 wt% in CS networks have been prepared, and the same were used to separate mixtures of water and ethanol at 25ºC in the pervaporation process. In particular, when 0.15 wt% of DUT-5 was loaded, MOF@CS membrane displayed excellent permeability and selectivity in ethanol/water separation than that of the previous literature. These CS based membranes separation through functionalized microporous MOFs reveals the key governing factors that are essential for designing novel MOF membranes for bioethanol purification.

Keywords: metal-organic framework, microporous materials, separation, chitosan membranes

Procedia PDF Downloads 219

Authors: Yuksel Akinay, Fatih Hayat

Abstract:

The influence of Ni elements on mechanical properties and microstructure of twinning induced plasticity (TWIP) steels were investigated in this study. TWIP 1 (0,6C, 24Mn) and TWIP 2 (0,6C, 24Mn, 1Ni) high Mn TWIP (Twinning Induced Plasticity) steels were fabricated, and were annealed at 700°C, 800°C and 900°C for 150 minute and then air-cooled. The microstructures and mechanical properties of specimens were analysed to investigate influence of Ni element on TWIP steel. The carbide precipitations have seen in microstructure of TWIP 1 and TWIP 2 specimen annealed at 700 °C. However, the microstructures of TWIP 1 annealed at 800°C and 900°C are fully austenite and some grains are including annealing twins. However twining did not occur at TWIP 2 specimens annealed at 700 °C, 800 °C and 900 °C. TWIP 2 steel contains also Ni element differently from TWIP 1 steel. It can conclude that, Nickel (Ni) was restrained formation of twinning. The reversion of the tensile strength occurred between 700°C and 800°C because of the carbide precipitation hardening. Beside that, hardness value has decreased between 800 °C and 900 °C, which show a good agreement with the equilibrium dissolution temperature of M3C carbides. However, the results show that, carbide precipitations also are as strong barriers for the formation of twining. For this reason, twinning was not obtained at 700 °C.

Keywords: high manganese, heat treatment, SEM, TWIP steel, cold rolling, nickel

Procedia PDF Downloads 356

Authors: Anne Bubriski

Abstract:

Despite improvements in gender inequalities, women and girls continue to face glass ceilings, underrepresentation, and harmful stereotypes that can limit their aspirations and opportunities in STEM. While girls are taking similar high school math and science classes, boys are more likely to take physics and six times more likely to take an engineering course. The gap becomes even larger for minority or low-income girls. This gender gap is not due to biology; rather, it is due to cultural, social, and institutional forces. As girls get older, these forces often ‘teach’ them ‘STEM is more for boys’. The STEM gender gap widens in college, with only 20% of engineering degrees being awarded to women, and by the time women enter the workforce, they only occupy about 13% of engineering jobs. At the University of Central Florida, the Women’s and Gender Studies Program has developed a unique mentoring program to address these issues, Science Leadership and Mentoring (SLAM). What is unique about the approach of SLAM is that we look to address this problem through leadership and STEM. We look to help girls make connections between leadership and STEM—that young women can be leaders as scientists and that scientists are leaders making a change. This is particularly needed and relevant to our community because while there are mentoring programs to our knowledge, SLAM is one of the only, if not only, mentoring programs pairing college women and 7th-grade girls that includes a focus both on STEM and leadership in the United States. SLAM is a curriculum-based mentoring program pairing one 7th-grade girl with one UCF undergraduate STEM major. SLAM empowers young women to be assertive, brave, confident, independent, inquisitive and proud leaders in STEM. SLAM seeks to promote young women’s inspiration and excitement into STEM fields and careers while also building leadership abilities such as problem-solving, teamwork and cooperation, cultural identity and ethnic pride, advocacy for positive change, and goals for the future. SLAM serves about fifteen 7th-grade girls for the academic year and about 20 UCF students. SLAM holds weekly mentoring meetings lasting about 90 minutes, covering topics on leadership, STEM majors and careers, and STEM leadership. This past year, SLAM received a Community Action Grant from the American Association of University Women (AAUW) to run a sub-program, SLAM-Space. SLAM-Space focused on exposing SLAM participants to aerospace engineering and other space-related STEM fields, such as physics and astronomy, through guest speakers, workshops and field trips, including the Kenndy Space Center. The proposed paper presentation will present an overview of SLAM-Space and the data findings from pre and post-surveys, in-depth interviews and focus groups from the SLAM participants' experiences in the program.

Keywords: gender, leadership, STEM, empowerment

Procedia PDF Downloads 39

Authors: Alicia Muñoz, Pedro Oyola, Cristian Henriquez

Abstract:

Pollution in Santiago de Chile has a spatial variability due to different factors, including meteorological parameters and emission sources. Socioenvironmental aspects are also significant for pollution in the canopy layer since it influences the type of edification, vegetal mass proportion and other environmental conditions. This study analyzes spatially urban pollution in Santiago, specifically, from the bike path perspective. Bike paths are located in high traffic zones, as consequence, users are constantly exposed to urban pollution. Measurements were made at the higher polluted hour, three days a week, including three transit regimes, on the most polluted month of the year. The environmental parameters are fine particulate matter (Model 8520, DustTrak Aerosol Monitor, TSI), temperature and relative humidity; it was also considerate urban parameters as sky view factor and vegetal mass. Identification of an environmental injustice will be achieved with a spatial modeling, including all urban factors and environmental mediations with an economic index of population.

Keywords: canopy layer, environmental injustice, spatial modeling, urban pollution

Procedia PDF Downloads 230

Authors: Jurriaan Gillissen

Abstract:

This work is concerned with stabilizing the numerical integration of the Navier-Stokes equation (NSE), backwards in time. Applications involve the detection of sources of, e.g., sound, heat, and pollutants. Stable reverse numerical integration of parabolic differential equations is also relevant for image de-blurring. While the literature addresses the reverse integration problem of the advection-diffusion equation, the problem of numerical reverse integration of the NSE has, to our knowledge, not yet been addressed. Owing to the presence of viscosity, the NSE is irreversible, i.e., when going backwards in time, the fluid behaves, as if it had a negative viscosity. As an effect, perturbations from the perfect solution, due to round off errors or discretization errors, grow exponentially in time, and reverse integration of the NSE is inherently unstable, regardless of using an implicit time integration scheme. Consequently, some sort of filtering is required, in order to achieve a stable, numerical, reversed integration. The challenge is to find a filter with a minimal adverse affect on the accuracy of the reversed integration. In the present work, we explore an adjoint gradient method (AGM) to achieve this goal, and we apply this technique to two-dimensional (2D), decaying turbulence. The AGM solves for the initial velocity field u0 at t = 0, that, when integrated forward in time, produces a final velocity field u1 at t = 1, that is as close as is feasibly possible to some specified target field v1. The initial field u0 defines a minimum of a cost-functional J, that measures the distance between u1 and v1. In the minimization procedure, the u0 is updated iteratively along the gradient of J w.r.t. u0, where the gradient is obtained by transporting J backwards in time from t = 1 to t = 0, using the adjoint NSE. The AGM thus effectively replaces the backward integration by multiple forward and backward adjoint integrations. Since the viscosity is negative in the adjoint NSE, each step of the AGM is numerically stable. Nevertheless, when applied to turbulence, the AGM develops instabilities, which limit the backward integration to small times. This is due to the exponential divergence of phase space trajectories in turbulent flow, which produces a multitude of local minima in J, when the integration time is large. As an effect, the AGM may select unphysical, noisy initial conditions. In order to improve this situation, we propose two remedies. First, we replace the integration by a sequence of smaller integrations, i.e., we divide the integration time into segments, where in each segment the target field v1 is taken as the initial field u0 from the previous segment. Second, we add an additional term (regularizer) to J, which is proportional to a high-order Laplacian of u0, and which dampens the gradients of u0. We show that suitable values for the segment size and for the regularizer, allow a stable reverse integration of 2D decaying turbulence, with accurate results for more then O(10) turbulent, integral time scales.

Keywords: time reversed integration, parabolic differential equations, adjoint gradient method, two dimensional turbulence

Procedia PDF Downloads 222

Authors: Sayem Zafar, Mahmood Rahi

Abstract:

Rigorous international maritime regulations are in place to limit boat and ship hydrocarbon emissions. The global sustainability goals are reducing the fuel consumption and minimizing the emissions from the ships and boats. These maritime sustainability goals have attracted a lot of research interest. Energy harvesting and storage system is designed in this study based on hybrid renewable and conventional energy systems. This energy harvesting and storage system is designed for marine applications, such as, boats and small ships. These systems can be utilized for mobile use or off-grid remote electrification. This study analyzed the use of micro power generation for boats and small ships. The energy harvesting and storage system has two distinct systems i.e. dockside shore-based system and on-board system. The shore-based system consists of a small wind turbine, photovoltaic (PV) panels, small gas turbine, hydrogen generator and high-pressure hydrogen storage tank. This dockside system is to provide easy access to the boats and small ships for supply of hydrogen. The on-board system consists of hydrogen storage tanks and fuel cells. The wind turbine and PV panels generate electricity to operate electrolyzer. A small gas turbine is used as a supplementary power system to contribute in case the hybrid renewable energy system does not provide the required energy. The electrolyzer performs the electrolysis on distilled water to produce hydrogen. The hydrogen is stored in high-pressure tanks. The hydrogen from the high-pressure tank is filled in the low-pressure tanks on-board seagoing vessels to operate the fuel cell. The boats and small ships use the hydrogen fuel cell to provide power to electric propulsion motors and for on-board auxiliary use. For shore-based system, a small wind turbine with the total length of 4.5 m and the disk diameter of 1.8 m is used. The small wind turbine dimensions make it big enough to be used to charge batteries yet small enough to be installed on the rooftops of dockside facility. The small dimensions also make the wind turbine easily transportable. In this paper, PV, sizing and solar flux are studied parametrically. System performance is evaluated under different operating and environmental conditions. The parametric study is conducted to evaluate the energy output and storage capacity of energy storage system. Results are generated for a wide range of conditions to analyze the usability of hybrid energy harvesting and storage system. This energy harvesting method significantly improves the usability and output of the renewable energy sources. It also shows that small hybrid energy systems have promising practical applications.

Keywords: energy harvesting, fuel cell, hybrid energy system, hydrogen, wind turbine

Procedia PDF Downloads 136

Authors: Cho-Liang Chung

Abstract:

Uniform and rapid drug release are important for trauma dressing application. Low glass transition polymer system and non-woven nanofiber structures as the designs conduct rapid-release characteristics. In this study, polyvinylpyrrolidone, polysulfone, and polystyrene were dissolved in dimethylformamide to form precursor solution. These solutions were blended with vitamin C to form the electrospinning solutions. The non-woven nanofibers structures were successfully prepared using an electrospinning process. The following instruments were used to analyze the characteristics of non-woven nanofibers structures: Atomic force microscopy (AFM), Field Emission Scanning Electron Microscope (FE-SEM), and X-ray Diffraction (XRD). The AFM was used to scan the nanofibers. 3D Graphics were applied to explore the surface morphology of nanofibers. FE-SEM was used to explore the morphology of non-woven structures. XRD was used to identify crystal structures in the non-woven structures. The evolution of morphology of non-woven structures was changed dramatically in different durations, because of the moisture absorption and decreasing glass transition temperature; the non-woven nanofiber structures can be applied to uniform and rapid drug release for trauma dressing application.

Keywords: nanofibers, non-woven, electrospinning process, rapid drug releasing

Procedia PDF Downloads 136

Authors: Olga Długosz, Jolanta Pulit-Prociak, Marcin Banach

Abstract:

The paper presents a process to obtain glutathione-modified titanium oxide nanoparticles. The processes were carried out in a microwave radiation field. The influence of the molar ratio of glutathione to titanium oxide and the effect of the fold of NaOH vs. stoichiometric amount on the size of the formed TiO₂ nanoparticles was determined. The physicochemical properties of the obtained products were evaluated using dynamic light scattering (DLS), transmission electron microscope- energy-dispersive X-ray spectroscopy (TEM-EDS), low-temperature nitrogen adsorption method (BET), X-Ray Diffraction (XRD) and Fourier-transform infrared spectroscopy (FTIR) microscopy methods. The size of TiO₂ nanoparticles was characterized from 30 to 336 nm. The release of titanium ions from the prepared products was evaluated. These studies were carried out using different media in which the powders were incubated for a specific time. These were water, SBF and Ringer's solution. The release of titanium ions from modified products is weaker compared to unmodified titanium oxide nanoparticles. The reduced release of titanium ions may allow the use of such modified materials as substances in drug delivery systems.

Keywords: titanium dioxide, nanoparticles, drug carrier, glutathione

Procedia PDF Downloads 79

Authors: Olga Długosz, Jolanta Pulit-Prociak, Marcin Banach

Abstract:

The paper presents a process to obtain glutathione-modified titanium oxide nanoparticles. The processes were carried out in a microwave radiation field. The influence of the molar ratio of glutathione to titanium oxide and the effect of the fold of NaOH vs. stoichiometric amount on the size of the formed TiO₂ nanoparticles was determined. The physicochemical properties of the obtained products were evaluated using dynamic light scattering (DLS), transmission electron microscope- energy-dispersive X-ray spectroscopy (TEM-EDS), low-temperature nitrogen adsorption method (BET), X-Ray Diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR) microscopy methods. The size of TiO₂ nanoparticles was characterized from 30 to 336 nm. The release of titanium ions from the prepared products was evaluated. These studies were carried out using different media in which the powders were incubated for a specific time. These were: water, SBF, and Ringer's solution. The release of titanium ions from modified products is weaker compared to unmodified titanium oxide nanoparticles. The reduced release of titanium ions may allow the use of such modified materials as substances in drug delivery systems.

Keywords: titanium dioxide, nanoparticles, drug carrier, glutathione

Procedia PDF Downloads 159

Authors: Gregory Schmidt

Abstract:

Solid-state lithium batteries are broadly accepted as promising candidates for application in the next generation of EVs as they should offer safer and higher-energy-density batteries. Nonetheless, their development is impeded by many challenges, including the resistive electrode–electrolyte interface originating from the removal of the liquid electrolyte that normally permeates through the porous cathode and ensures efficient ionic conductivity through the cell. One way to tackle this challenge is by formulating composite cathodes containing solid ionic conductors in their structure, but this approach will require the conductors to exhibit chemical stability, electrochemical stability, flexibility, and adhesion and is, therefore, limited to some materials. Recently, Arkema developed a technology called buffering layer which allows the transformation of any conventional porous electrode into a catholyte. This organic layer has a very high ionic conductivity at room temperature, is compatible with all active materials, and can be processed with conventional Gigafactory equipment. Moreover, this layer helps protect the solid ionic conductor from the cathode and anode materials. During this presentation, the manufacture and the electrochemical performance of this layer for different systems of cathode and anode will be discussed.

Keywords: electrochemistry, all solid state battery, materials, interface

Procedia PDF Downloads 94

Authors: Nadjet Taoualit, Zoubida Chemat, Djamel-Eddine Hadj-Boussaad

Abstract:

This study aims the removal of copper Cu (II) contained in wastewater by adsorption on a perfect synthesized mud. It is the materials Hydroxides Double Lamellar, HDL, prepared and synthesized by co-precipitation method at constant pH, which requires a simple titration assembly, with an inexpensive and available material in the laboratory, and also allows us better control of the composition of the reaction medium, and gives well crystallized products. A characterization of the adsorbent proved essential. Thus a range of physic-chemical analysis was performed including: FTIR spectroscopy, X-ray diffraction… The adsorption of copper ions was investigated in dispersed medium (batch). A systematic study of various parameters (amount of support, contact time, initial copper concentration, temperature, pH…) was performed. Adsorption kinetic data were tested using pseudo-first order, pseudo-second order, Bangham's equation and intra-particle diffusion models. The equilibrium data were analyzed using Langmuir, Freundlich, Tempkin and other isotherm models at different doses of HDL. The thermodynamics parameters were evaluated at different temperatures. The results have established good potentiality for the HDL to be used as a sorbent for the removal of Copper from wastewater.

Keywords: adsoption, copper, HDL, isotherm

Procedia PDF Downloads 274

Authors: Abbas S. Alwan, Waleed K. Hussan

Abstract:

In this paper, a general verification of possible heat treatment of steel has been done with the view of conditions of real abrasive wear of rotivater with soil texture. This technique is found promising to improve the quality of agriculture components working with the soil in dry condition. Abrasive wear resistance is very important in many applications and in most cases it is directly correlated with the hardness of materials surface. Responded of heat treatments were carried out in various media (Still air, Cottonseed oil, and Brine water 10 %) and follow by low-temperature tempering (250°C) was applied on steel type (AISI 1030). After heat treatment was applied wear with soil texture by using tillage process to determine the (actual wear rate) of the specimens depending on weight loss method. It was found; the wear resistance Increases with increase hardness with varying quenching media as follows; 30 HRC, 45 HRC, 52 HRC, and 60 HRC for nontreated (as received) cooling media as still air, cottonseed oil, and Brine water 10 %, respectively. Martensitic structure with retained austenite can be obtained depending on the quenching medium. Wear was presented on the worn surfaces of the steels which were used in this work.

Keywords: microstructures, hardness, abrasive wear, heat treatment, soil texture

Procedia PDF Downloads 386

Authors: Pimchanok Puksisuwan, Pitak Laorattanakul, Benya Cherdhirunkorn

Abstract:

The use of aluminium dross as a raw material for geopolymer synthesis via mechanochemistry method was studied. The geopolymers were prepared using aluminium dross from secondary aluminium industry, fly ash from a biomass power plant and liquid alkaline activators, which is a mixture of sodium silicate solution (Na2SiO3) and sodium hydroxide solution (NaOH) (Na2SiO3/NaOH ratio 4:1, 3:1 and 2:1). Aluminium dross consists mostly of alumina (Al2O3), silicon oxide (SiO2) and aluminium nitride (AlN). The raw materials were mixed and milled using the high energy ball milling method for 5, 10 and 15 minutes in order to reduce the particle size. The milled powders were uniaxially pressed into a cylinder die with the pressure of 2200 psi. The cylinder samples were cured in the sealed plastic bags for 3, 7 and 14 days at the room temperature and 60°C for 24 hour. The mechanical property of geopolymers was investigated. In addition, scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis were carried out in order to study the microstructure and phase structures of the geopolymers, respectively. The results showed that aluminium dross could enhance the mechanical property of geopolymers product by mechanochemistry method and meet the TISI requirements.

Keywords: aluminium dross, fly ash, geopolymer, mechanochemistry

Procedia PDF Downloads 252

Authors: Hamdy M. Youssef

Abstract:

In this work, the usual Euler–Bernoulli nanobeam has been modeled in the context of Lord-Shulman thermoelastic theorem, which contains non-Fourier heat conduction law. The nanobeam has been subjected to a constant magnetic field and ramp-type thermal loading. The Laplace transform definition has been applied to the governing equations, and the solutions have been obtained by using a direct approach. The inversions of the Laplace transform have been calculated numerically by using Tzou approximation method. The solutions have been applied to a nanobeam made of silicon nitride. The distributions of the temperature increment, lateral deflection, strain, stress, and strain-energy density have been represented in figures with different values of the magnetic field intensity and ramp-time heat parameter. The value of the magnetic field intensity and ramp-time heat parameter have significant effects on all the studied functions, and they could be used as tuners to control the energy which has been generated through the nanobeam.

Keywords: nanobeam, vibration, constant magnetic field, ramp-type thermal loading, non-Fourier heat conduction law

Procedia PDF Downloads 136

Authors: M. Amoura, M. Benmoussa, N. Zeraibi

Abstract:

The flow and heat transfer is an important phenomenon in engineering systems due to its wide application in electronic cooling, heat exchangers, double pane windows etc.. The enhancement of heat transfer in these systems is an essential topic from an energy saving perspective. Lower heat transfer performance when conventional fluids, such as water, engine oil and ethylene glycol are used hinders improvements in performance and causes a consequent reduction in the size of such systems. The use of solid particles as an additive suspended into the base fluid is a technique for heat transfer enhancement. Therefore, the heat transfer enhancement in a horizontal circular tube that is maintained at a constant temperature under laminar regime has been investigated numerically. A computational code applied to the problem by use of the finite volume method was developed. Nanofluid was made by dispersion of Al2O3 nanoparticles in pure water and ethylene glycol. Results illustrate that the suspended nanoparticles increase the heat transfer with an increase in the nanoparticles volume fraction and for a considered range of Reynolds numbers. On the other hand, the heat transfer is very sensitive to the base fluid.

Keywords: Al2O3 nanoparticles, circular tube, heat transfert enhancement, numerical simulation

Procedia PDF Downloads 320

Authors: Deniz Sahin

Abstract:

This study provides a literature review of the special issue on wastewater treatment technologies, especially membrane technologies. Currently, wastewater is a serious and increasing worldwide problem with an adverse effect on the environment and living organisms. For this reason, many technologies have been developed to treat wastewater before discharging it to water bodies. We have been discussed membrane technologies to remove contaminants from wastewater such as heavy metals, dyes, pesticides, etc., which represent the main pollutants in wastewater. All the properties of these technologies including performance, economics, simplicity, and operability are also compared with other wastewater treatment technologies. The conventional water treatment technologies have the disadvantages of low separation efficiency, high energy consumption, and strict operating temperature. To overcome these difficulties, membrane technologies have been developed and used in wastewater treatment. Membrane technology uses a selectively permeable membrane to remove suspended and dissolved solids from water. This membrane is a very thin film of synthetic organic or inorganic materials, that can allow a very selective separation between a mixture and its components. Examples of membrane technologies include microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), electrodialysis (ED), gas separation, etc. Most of these technologies have been used extensively for the treatment of heavy metal wastewater. For instance, wastewater that contains Cu²⁺, Cd²⁺, Pb²⁺, Zn²⁺ was treated by ultrafiltration technology. It was shown that complete removal of metal ions could be achieved.

Keywords: industrial pollution, membrane technologies, metal ions, wastewater

Procedia PDF Downloads 194

Authors: Veronica Caprai, Katrin Schollbach, Miruna V. A. Florea, H. J. H. Brouwers

Abstract:

Nowadays MSWI (Municipal Solid Waste Incineration) bottom ash (BA) produced by Waste-to-Energy (WtE) plants represents the majority of the solid residues derived from MSW incineration. Once processed, the BA is often landfilled resulting in possible environmental problems, additional costs for the plant and increasing occupation of public land. In order to limit this phenomenon, European countries such as the Netherlands aid the utilization of MSWI BA in the construction field, by providing standards about the leaching of contaminants into the environment (Dutch Soil Quality Decree). Commonly, BA has a particle size below 32 mm and a heterogeneous chemical composition, depending on its source. By washing coarser BA, an MSWI sludge is obtained. It is characterized by a high content of heavy metals, chlorides, and sulfates as well as a reduced particle size (below 0.25 mm). To lower its environmental impact, MSWI sludge is filtered or centrifuged for removing easily soluble contaminants, such as chlorides. However, the presence of heavy metals is not easily reduced, compromising its possible application. For lowering the leaching of those contaminants, the use of MSWI residues in combination with cement represents a precious option, due to the known retention of those ions into the hydrated cement matrix. Among the applications, the European standard for common cement EN 197-1:1992 allows the incorporation of up to 5% by mass of a minor additional constituent (MAC), such as fly ash or blast furnace slag but also an unspecified filler into cement. To the best of the author's knowledge, although it is widely available, it has the appropriate particle size and a chemical composition similar to cement, FC has not been investigated as possible MAC in cement production. Therefore, this paper will address the suitability of MSWI FC as MAC for CEM I 52.5 R, within a 5% maximum replacement by mass. After physical and chemical characterization of the raw materials, the crystal phases of the pastes are determined by XRD for 3 replacement levels (1%, 3%, and 5%) at different ages. Thereafter, the impact of FC on mechanical and environmental performances of cement is assessed according to EN 196-1 and the Dutch Soil Quality Decree, respectively. The investigation of the reaction products evidences the formation of layered double hydroxides (LDH), in the early stage of the reaction. Mechanically the presence of FC results in a reduction of 28 days compressive strength by 8% for a replacement of 5% wt., compared with the pure CEM I 52.5 R without any MAC. In contrast, the flexural strength is not affected by the presence of FC. Environmentally, the Dutch legislation for the leaching of contaminants for unshaped (granular) material is satisfied. Based on the collected results, FC represents a suitable candidate as MAC in cement production.

Keywords: environmental impact evaluation, Minor additional constituent, MSWI residues, X-ray diffraction crystallography

Procedia PDF Downloads 177

Authors: Princess Stephanie P. Llanos, Rinlee Butch M. Cervera

Abstract:

Lithium iron phosphate (LiFePO4) is a potential cathode material for lithium-ion batteries due to its promising characteristics. In this study, carbon-coated nanograined LiFePO4 is synthesized via wet chemistry method at a low temperature of 400 °C and investigated its performance as a cathode in Lithium battery. The X-ray diffraction pattern of the synthesized samples can be indexed to an orthorhombic LiFePO4 structure. Agglomerated particles that range from 200 nm to 300 nm are observed from scanning electron microscopy images. Transmission electron microscopy images confirm the crystalline structure of LiFePO4 and coating of amorphous carbon layer. Elemental mapping using Energy dispersive spectroscopy analysis revealed the homogeneous dispersion of Fe, P, O, and C elements. On the other hand, the electrochemical performances of the synthesized cathodes were investigated using cyclic voltammetry, galvanostatic charge/discharge tests with different C-rates, and cycling performances. Galvanostatic charge and discharge measurements revealed that the sample sintered at 400 °C for 3 hours with carbon coating demonstrated the highest capacity among the samples which reaches up to 160 mAhg⁻¹ at 0.1C rate.

Keywords: cathode, charge-discharge, electrochemical, lithium batteries

Procedia PDF Downloads 330

Authors: Zahra Okba, Hassan El Ouizgani

Abstract:

Anticipating an individual’s behavior to the environmental factors allows for having relevant ecological forecasts. The Dynamic Energy Budget model facilitates prediction, and it is mechanically dependent on biology to abiotic factors but is generally field verified under relatively stable physical conditions. Dynamic Energy Budget Theory (DEB) is a robust framework that can link the individual state to environmental factors, and in our work, we have tested its ability to account for variability by looking at model predictions in the Agadir Bay, which is characterized by a semi-arid climate and temperature is strongly influenced by the trade winds front and nutritional availability. From previous works in our laboratory, we have collected different biological DEB model parameters of Mytilus galloprovincialis mussel in Agadir Bay. We mathematically formulated the equations that make up the DEB model and then adjusted our analytical functions with the observed biological data of our local species. We also assumed the condition of constant immersion, and then we integrated the details of the tidal cycles to calculate the metabolic depression at low tide. Our results are quite satisfactory concerning the length and shape of the shell in one part and the gonadosomatic index in another part.

Keywords: dynamic energy budget, mussels, mytilus galloprovincialis, agadir bay, DEB model

Procedia PDF Downloads 114

Authors: Ali Driouiche, Abdallah Hadfi

Abstract:

During this work on scaling phenomenon observed in the irrigation water pipes in the agricultural region of Greater Agadir, a follow-up was carried out during a year of the physico-chemical quality of these waters. Sampling was conducted from 120 sampling points, well distributed in the study area and involved 120 water samples. The parameters measured for each sample are temperature, pH, conductivity, total hardness and the concentrations of the ions HCO₃₋, Ca²⁺, Mg²⁺, Na⁺, K⁺, SO₄₋, NO₃₋, Cl₋ and OH₋. Indeed, the monitoring of the physico-chemical quality shows that the total hardness varies between 20 and 65 °F and the complete alkalimetric title varies from 14 °F to 42 °F. For the kinetic study of the scaling power, an object of this work, 6 samples which have high hardness were selected from the 120 samples analyzed. This study was carried out using the controlled degassing method Laboratoire de Chimie et de Génie de l’Environnement (LCGE) where it was developed) and showed that the studied waters are calcifying. The germination time Tg varies between 16 and 34 minutes. The highlighting of new scale inhibitors to prevent the formation of scale in the pipelines of the agricultural sector of Greater Agadir will also be discussed.

Keywords: agadir, clogging pipes, localized irrigation, scaling power

Procedia PDF Downloads 120