Search results for: high-resolution infrared spectra

Authors: Ariadne C. Catto, Luis F. da Silva, Khalifa Aguir, Valmor Roberto Mastelaro

Abstract:

Zinc oxide (ZnO) pure or doped are one of the most promising metal oxide semiconductors for gas sensing applications due to the well-known high surface-to-volume area and surface conductivity. It was shown that ZnO is an excellent gas-sensing material for different gases such as CO, O2, NO2 and ethanol. In this context, pure and doped ZnO exhibiting different morphologies and a high surface/volume ratio can be a good option regarding the limitations of the current commercial sensors. Different studies showed that the sensitivity of metal-doped ZnO (e.g. Co, Fe, Mn,) enhanced its gas sensing properties. Motivated by these considerations, the aim of this study consisted on the investigation of the role of Co ions on structural, morphological and the gas sensing properties of nanostructured ZnO samples. ZnO and Zn1-xCoxO (0 < x < 5 wt%) thin films were obtained via the polymeric precursor method. The sensitivity, selectivity, response time and long-term stability gas sensing properties were investigated when the sample was exposed to a different concentration range of ozone (O3) at different working temperatures. The gas sensing property was probed by electrical resistance measurements. The long and short-range order structure around Zn and Co atoms were investigated by X-ray diffraction and X-ray absorption spectroscopy. X-ray photoelectron spectroscopy measurement was performed in order to identify the elements present on the film surface as well as to determine the sample composition. Microstructural characteristics of the films were analyzed by a field-emission scanning electron microscope (FE-SEM). Zn1-xCoxO XRD patterns were indexed to the wurtzite ZnO structure and any second phase was observed even at a higher cobalt content. Co-K edge XANES spectra revealed the predominance of Co2+ ions. XPS characterization revealed that Co-doped ZnO samples possessed a higher percentage of oxygen vacancies than the ZnO samples, which also contributed to their excellent gas sensing performance. Gas sensor measurements pointed out that ZnO and Co-doped ZnO samples exhibit a good gas sensing performance concerning the reproducibility and a fast response time (around 10 s). Furthermore, the Co addition contributed to reduce the working temperature for ozone detection and improve the selective sensing properties.

Keywords: cobalt-doped ZnO, nanostructured, ozone gas sensor, polymeric precursor method

Procedia PDF Downloads 247

Authors: Anna Zimoch-Korzycka, Dominika Kulig, Andrzej Jarmoluk

Abstract:

The aim of this study was to obtain chitooligosaccharides from chitosan with better functional properties using three different enzyme preparations and compare the products of enzymatic hydrolysis. Commercially available cellulase (CL), xylanase (X) and chitosanase (CS) preparations were used to investigate hydrolytic activity on chitosan (CH) with low molecular weight and DD of 75-85%. It has been reported that CL and X have side activities of other enzymes, such as β-glucanase or β-glucosidase. CS enzyme has a foreign activity of chitinase. Each preparation was used in 1000 U of activity and in the same reaction conditions. The degree of deacetylation and molecular weight of chitosan were specified using titration and viscometric methods, respectively. The hydrolytic activity of enzymes preparations on chitosan was monitored by dynamic viscosity measurement. After 4 h reaction with stirring, solutions were filtered and chitosan oligomers were isolated by methanol solution into two fractions: precipitate (A) and supernatant (B). A Fourier-transform infrared spectroscopy was used to characterize the structural changes of chitosan oligomers fractions and initial chitosan. Furthermore, the solubility of lyophilized hydrolytic mixture (C) and two chitooligomers fractions (A, B) of each enzyme hydrolysis was assayed. The antioxidant activity of chitosan oligomers was evaluated as DPPH free radical scavenging activity. The dynamic viscosity measured after addition of enzymes preparation to the chitosan solution decreased dramatically over time in the sample with X in comparison to solution without the enzyme. For mixtures with CL and CS, lower viscosities were also recorded but not as low as the ones with X. A and B fractions were characterized by the most similar viscosity obtained by the xylanase hydrolysis and were 15 mPas and 9 mPas, respectively. Structural changes of chitosan oligomers A, B, C and their differences related with various enzyme preparations used were confirmed. Water solubility of A fractions was not possible to filter and the result was not recorded. Solubility of supernatants was approximately 95% and was higher than hydrolytic mixture. It was observed that the DPPH radical scavenging effect of A, B, C samples is the highest for X products and was approximately 13, 17, 19% respectively. In summary, a mixture of chitooligomers may be useful for the design of edible protective coatings due to the improved biophysical properties.

Keywords: cellulase, xylanase, chitosanase, chitosan, chitooligosaccharides

Procedia PDF Downloads 326

Authors: Vanessa Morgado, Ricardo Bettencourt da Silva, Carla Palma

Abstract:

The environmental pollution by microplastics is well recognized. Microplastics were already detected in various matrices from distinct environmental compartments worldwide, some from remote areas. Various methodologies and techniques have been used to determine microplastic in such matrices, for instance, sediment samples from the ocean bottom. In order to determine microplastics in a sediment matrix, the sample is typically sieved through a 5 mm mesh, digested to remove the organic matter, and density separated to isolate microplastics from the denser part of the sediment. The physical analysis of microplastic consists of visual analysis under a stereomicroscope to determine particle size, colour, and shape. The chemical analysis is performed by an infrared spectrometer coupled to a microscope (micro-FTIR), allowing to the identification of the chemical composition of microplastic, i.e., the type of polymer. Creating legislation and policies to control and manage (micro)plastic pollution is essential to protect the environment, namely the coastal areas. The regulation is defined from the known relevance and trends of the pollution type. This work discusses the assessment of contamination trends of a 700 km² oceanic area affected by contamination heterogeneity, sampling representativeness, and the uncertainty of the analysis of collected samples. The methodology developed consists of objectively identifying meaningful variations of microplastic contamination by the Monte Carlo simulation of all uncertainty sources. This work allowed us to unequivocally conclude that the contamination level of the studied area did not vary significantly between two consecutive years (2018 and 2019) and that PET microplastics are the major type of polymer. The comparison of contamination levels was performed for a 99% confidence level. The developed know-how is crucial for the objective and binding determination of microplastic contamination in relevant environmental compartments.

Keywords: measurement uncertainty, micro-ATR-FTIR, microplastics, ocean contamination, sampling uncertainty

Procedia PDF Downloads 89

Authors: Shady S. Hassan, Brijesh K. Tiwari, Gwilym A. Williams, Amit K. Jaiswal

Abstract:

Waste materials from a wide range of agro-industrial processes may be used as substrates for microbial growth, and subsequently the production of a range of high value products and bioenergy. In addition, utilization of these agro-residues in bioprocesses has the dual advantage of providing alternative substrates, as well as solving their disposal problems. Spent coffee grounds (SCG) are a by-product (45%) of coffee processing. SCG is a lignocellulosic material, which is composed mainly of cellulose, hemicelluloses, and lignin. Thus, a pretreatment process is required to facilitate an efficient enzymatic hydrolysis of such carbohydrates. In this context, microwave pretreatment of lignocellulosic biomass without the addition of harsh chemicals represents a green technology. Moreover, microwave treatment has a high heating efficiency and is easy to implement. Thus, microwave pretreatment of SCG without adding of harsh chemicals investigated as a green technology to enhance enzyme hydrolysis. In the present work, microwave pretreatment experiments were conducted on SCG at varying power levels (100, 250, 440, 600, and 1000 W) for 60 s. By increasing microwave power to a certain level (which vary by varying biomass), reducing sugar increases, then reducing sugar from biomass start to decrease with microwave power increase beyond this level. Microwave pretreatment of SCG at 60s followed by enzymatic hydrolysis resulted in total reducing sugars of 91.6 ± 7.0 mg/g of biomass (at microwave power of 100 w). Fourier transform Infrared Spectroscopy (FTIR) was employed to investigate changes in functional groups of biomass after pretreatment, while high-performance liquid chromatography (HPLC) was employed for determination of glucose. Pretreatment of lignocellulose using microwave was found to be an effective and energy efficient technology to improve saccharification and glucose yield. Energy performance will be evaluated for the microwave pretreatment, and the enzyme hydrolysate will be used as media component substitute for the production of ethanol and other high value products.

Keywords: lignocellulose, microwave, pretreatment, spent coffee grounds

Procedia PDF Downloads 419

Authors: Kanika Kalra, Harmeet Kaur, Dinesh Goyal

Abstract:

Total phenolics were extracted from waste orange peels by solvent extraction and alkali hydrolysis method. The most efficient solvents for extracting phenolic compounds from waste biomass were methanol (60%) > dimethyl sulfoxide > ethanol (60%) > distilled water. The extraction yields were significantly impacted by solvents (ethanol, methanol, and dimethyl sulfoxide) due to varying polarity and concentrations. Extraction of phenolics using 60% methanol yielded the highest phenolics (in terms of gallic acid equivalent (GAE) per gram of biomass) in orange peels. Alkali hydrolyzed extract from orange peels contained 7.58±0.33 mg GAE g⁻¹. By using the solvent extraction technique, it was observed that 60% methanol is comparatively the best-suited solvent for extracting polyphenolic compounds and gave the maximum yield of 4.68 ± 0.47 mg GAE g⁻¹ in orange peel extracts. DPPH radical scavenging activity and reducing the power of orange peel extract were checked, where 60% methanolic extract showed the highest antioxidant activity, 85.50±0.009% for DPPH, and dimethyl sulfoxide (DMSO) extract gave the highest yield of 1.75±0.01% for reducing power ability of the orange peels extract. Characterization of the polyphenolic compounds was done by using Fourier transformation infrared (FTIR) spectroscopy. Solvent and alkali hydrolysed extracts were evaluated for antibacterial activity using the agar well diffusion method against Gram-positive Bacillus subtilis MTCC441 and Gram-negative Escherichia coli MTCC729. Methanolic extract at 300µl concentration showed an inhibition zone of around 16.33±0.47 mm against Bacillus subtilis, whereas, for Escherichia coli, it was comparatively less. Broth-based turbidimetric assay revealed the antibacterial effect of different volumes of orange peel extracts against both organisms.

Keywords: orange peels, total phenolic content, antioxidant, antibacterial

Procedia PDF Downloads 73

Authors: Tamar Trop, Boris Portnov

Abstract:

Public Space Lighting (PSL) of outdoor urban areas promotes comfort, defines spaces and neighborhood identities, enhances perceived safety and security, and contributes to residential satisfaction and wellbeing. However, if excessive or misdirected, PSL leads to unnecessary energy waste and increased greenhouse gas emissions, poses a non-negligible threat to the nocturnal environment, and may become a potential health hazard. At present, PSL is designed according to international, regional, and national standards, which consolidate best practice. Yet, knowledge regarding the optimal light characteristics needed for creating a perception of personal comfort and safety in densely populated residential areas, and the factors associated with this perception, is still scarce. The presented study suggests a paradigm shift in designing PSL towards a user-centered approach, which incorporates pedestrians' perspectives into the process. The study is an ongoing joint research project between China and Israel Ministries of Science and Technology. Its main objectives are to reveal inhabitants' perceptions of and preferences for PSL in different densely populated neighborhoods in China and Israel, and to develop a model that links instrumentally measured parameters of PSL (e.g., intensity, spectra and glare) with its perceived comfort and quality, while controlling for three groups of attributes: locational, temporal, and individual. To investigate measured and perceived PSL, the study employed various research methods and data collection tools, developed a location-based mobile application, and used multiple data sources, such as satellite multi-spectral night-time light imagery, census statistics, and detailed planning schemes. One of the study’s preliminary findings is that higher sense of safety in the investigated neighborhoods is not associated with higher levels of light intensity. This implies potential for energy saving in brightly illuminated residential areas. Study findings might contribute to the design of a smart and adaptive PSL strategy that enhances pedestrians’ perceived safety and comfort while reducing light pollution and energy consumption.

Keywords: energy efficiency, light pollution, public space lighting, PSL, safety perceptions

Procedia PDF Downloads 133

Authors: Da-Wei Wang, Liang Yang, Xuan-Long Peng, Mei-Chuan Kuo, Jen-Taut Yeh

Abstract:

The tensile retention and waterproof properties of thermoplastic starch (TPS) resins were significantly enhanced by modifying with proper amounts of citric acid (CA) and by melt-blending with poly(lactic acid) (PLA), although no distinguished chemical reaction occurred between CA and starch molecules. As evidenced by Fourier transform infrared spectroscopy and Solid-state 13C Nuclear Magnetic Resonance analyses, disruption of intra and interhydrogen-bondings within starch molecules did occur during the modification processes of CA modified TPS (i.e. TPS100CAx) specimens. The tensile strength (σf) retention values of TPS specimens reduced rapidly from 27.8 to 20.5 and 0.4 MPa, respectively, as the conditioning time at 20°C/50% relative humidity (RH) increased from 0 to 7 and 70 days, respectively. While the elongation at break (εf) retention values of TPS specimens increased rapidly from 5.9 to 6.5 and 34.8%, respectively, as the conditioning time increased from 0 to 7 and 70 days. After conditioning at 20°C/50% RH for 70 days, the σf and εf retention values of the best prepared (TPS100CA0.1)30PLA70 specimen are equivalent to 85% and 167% of its initial σf and εf values, respectively, and are more than 105 times higher but 48% lower than those of TPS specimens conditioned at 20°C/50% RH for the same amount of time. Demarcated diffraction peaks, new melting endotherms of recrystallized starch crystals and distinguished ductile characteristics with drawn debris were found for many conditioned TPS specimens, however, only slight retrogradation effect and much less drawn debris was found for most conditioned TPS100CAx and/or (TPS100CA0.1)xPLAy specimens. The significantly improved water proof, tensile retention properties and relatively unchanged in retrogradation effect found for most conditioned TPS100CAx and/or (TPS100CA0.1)xPLAy specimens are apparently due to the efficient blocking of the moisture-absorbing hydroxyl groups (free or hydrogen bonded) by hydrogen-bonding CA with starch molecules during their modification processes.

Keywords: thermoplastic starch, hydrogen-bonding, water proof, strength retention

Procedia PDF Downloads 305

Authors: Marco Furinghetti, Alberto Pavese, Michele Rinaldi

Abstract:

Concave Surface Slider devices have been more and more used in real applications for seismic protection of both bridge and building structures. Several research activities have been carried out, in order to investigate the lateral response of such a typology of devices, and a reasonably high level of knowledge has been reached. If radial analysis is performed, the frictional force is always aligned with respect to the restoring force, whereas under bidirectional seismic events, a bi-axial interaction of the directions of motion occurs, due to the step-wise projection of the main frictional force, which is assumed to be aligned to the trajectory of the isolator. Nonetheless, if non-linear time history analyses have to be performed, standard codes provide precise rules for the definition of an averagely spectrum-compatible set of accelerograms in radial conditions, whereas for bidirectional motions different combinations of the single components spectra can be found. Moreover, nowadays software for the adjustment of natural accelerograms are available, which lead to a higher quality of spectrum-compatibility and to a smaller dispersion of results for radial motions. In this endeavor a simplified design procedure is defined, for building structures, base-isolated by means of Concave Surface Slider devices. Different case study structures have been analyzed. In a first stage, the capacity curve has been computed, by means of non-linear static analyses on the fixed-base structures: inelastic fiber elements have been adopted and different direction angles of lateral forces have been studied. Thanks to these results, a linear elastic Finite Element Model has been defined, characterized by the same global stiffness of the linear elastic branch of the non-linear capacity curve. Then, non-linear time history analyses have been performed on the base-isolated structures, by applying seven bidirectional seismic events. The spectrum-compatibility of bidirectional earthquakes has been studied, by considering different combinations of single components and adjusting single records: thanks to the proposed procedure, results have shown a small dispersion and a good agreement in comparison to the assumed design values.

Keywords: concave surface slider, spectrum-compatibility, bidirectional earthquake, base isolation

Procedia PDF Downloads 292

Authors: W. El-Alami, J. Araña, O. González Díaz, J. M. Doña Rodríguez

Abstract:

The efficiency of the semiconductor TiO₂ needs to be improved to be an effective tool for pollutant removal. To improve the efficiency of this semiconductor, it is necessary to deepen the knowledge of the processes that take place on its surface. In this sense, the deactivation of the catalyst is one of the aspects considered relevant. In order to study this point, the processes of deactivation of TiO₂ during the gas phase degradation of ethanol have been studied. For this, catalysts with only the anatase phase (SA and PC100) and catalysts with anatase and rutile phases (P25 and P90) have been selected. In order to force the deactivation processes, different cycles have been performed, adding ethanol gas but avoiding the degradation of acetates to determine their effect on the process. The surface concentration of fluorine on the catalysts was semi-quantitatively determined by EDAX analysis. The photocatalytic experiments were done with four commercial catalysts (P25, SA, P90, and PC100) and the two fluoride catalysts indicated above. The interaction and photocatalytic degradation of ethanol were followed by Fourier transform infrared spectroscopy (FTIR). EDAX analysis has revealed the presence of sodium on the surface of fluorinated catalysts. In FTIR studies, it has been observed that the acetates adsorbed on the anatase phase in P25 and P90 give rise to electron transfer to surface traps that modify the electronic states of the semiconductor. These deactivation studies have also been carried out with fluorinated P25 and SA catalysts (F-P25 and F-SA) which have observed similar electron transfers but in the opposite direction during illumination. In these materials, it has been observed that the electrons present in the surface traps, as a consequence of the interaction Ti-F, react with the holes, causing a change in the electronic states of the semiconductor. In this way, deactivated states of these materials have been detected by different electron transfer routes. It has been identified that acetates produced from the degradation of ethanol in P25 and P90 are probably hydrated on the surface of the rutile phase. In the catalysts with only the anatase phase (SA and PC100), the deactivation is immediate if the acetates are not removed before adsorbing ethanol again. In F-P25 and F-SA has been observed that the acetates formed react with the sodium ions present on the surface and not with the Ti atoms because they are interacting with the fluorine.

Keywords: photocatalytic degradation, ethanol, TiO₂, deactivation process, F-P25

Procedia PDF Downloads 74

Authors: Aurea C. L. Lacerda, Paulo R. H. Moreno, Bruna M. P. Vianna, Cristina H. R. Serra, Airton Martin, André R. Baby, Vladi O. Consiglieri, Telma M. Kaneko

Abstract:

The modified Franz cell is the most widely used model for in vitro permeation studies, however it still presents some disadvantages. Thus, some alternative methods have been developed such as Skin PAMPA, which is a bio- artificial membrane that has been applied for skin penetration estimation of xenobiotics based on HT permeability model consisting. Skin PAMPA greatest advantage is to carry out more tests, in a fast and inexpensive way. The membrane system mimics the stratum corneum characteristics, which is the primary skin barrier. The barrier properties are given by corneocytes embedded in a multilamellar lipid matrix. This layer is the main penetration route through the paracellular permeation pathway and it consists of a mixture of cholesterol, ceramides, and fatty acids as the dominant components. However, there is no consensus on the membrane composition. The objective of this work was to compare the performance among different bio-artificial membranes for studying the permeation in skin PAMPA system. Material and methods: In order to mimetize the lipid composition`s present in the human stratum corneum six membranes were developed. The membrane composition was equimolar mixture of cholesterol, ceramides 1-O-C18:1, C22, and C20, plus fatty acids C20 and C24. The membrane integrity assay was based on the transport of Brilliant Cresyl Blue, which has a low permeability; and Lucifer Yellow with very poor permeability and should effectively be completely rejected. The membrane characterization was performed using Confocal Laser Raman Spectroscopy, using stabilized laser at 785 nm with 10 second integration time and 2 accumulations. The membrane behaviour results on the PAMPA system were statistically evaluated and all of the compositions have shown integrity and permeability. The confocal Raman spectra were obtained in the region of 800-1200 cm-1 that is associated with the C-C stretches of the carbon scaffold from the stratum corneum lipids showed similar pattern for all the membranes. The ceramides, long chain fatty acids and cholesterol in equimolar ratio permitted to obtain lipid mixtures with self-organization capability, similar to that occurring into the stratum corneum. Conclusion: The artificial biological membranes studied for Skin PAMPA showed to be similar and with comparable properties to the stratum corneum.

Keywords: bio-artificial membranes, comparison, confocal Raman, skin PAMPA

Procedia PDF Downloads 509

Authors: Diana Karina Baigts Allende, Mariana Gonzalez Diaz, Luis Antonio Chel Guerrero, Mukthar Sandoval Peraza

Abstract:

Poverty and food insecurity are still incident problems in the developing countries, where population´s diet is based on cereals which are lack in protein content. Nevertheless, during last years the use of native plants has been studied as an alternative source of protein in order to improve the nutritional intake. Chaya crop also called Spinach tree, is a prehispanic plant native from Central America and South of Mexico (Mayan culture), which has been especially valued due to its high nutritional content particularly protein and some medicinal properties. The aim of this work was to study the effect of protein isolation processing from Chaya leaf harvest in Yucatan, Mexico on its structure quality in order: i) to valorize the Chaya crop and ii) to produce low-cost and high-quality protein. Chaya leaf was extruded, clarified and recovered using: a) acid precipitation by decreasing the pH value until reach the isoelectric point (3.5) and b) thermal coagulation, by heating the protein solution at 80 °C during 30 min. Solubilized protein was re-dissolved in water and spray dried. The presence of Fraction I protein, known as RuBisCO (Rubilose-1,5-biphosfate carboxylase/oxygenase) was confirmed by gel electrophoresis (SDS-PAGE) where molecular weight bands of 55 KDa and 12 KDa were observed. The infrared spectrum showed changes in protein structure due to the isolation method. The use of high temperatures (thermal coagulation) highly decreased protein solubility in comparison to isoelectric precipitated protein, the nutritional properties according to amino acid profile was also disturbed, showing minor amounts of overall essential amino acids from 435.9 to 367.8 mg/g. Chaya protein isolate obtained by acid precipitation showed higher protein quality according to essential amino acid score compared to FAO recommendations, which could represent an important sustainable source of protein for human consumption.

Keywords: chaya leaf, nutritional properties, protein isolate, protein structure

Procedia PDF Downloads 341

Authors: Mohsin Ejaz, Shiao-Wei Kuo

Abstract:

The growing production and exploitation of fossil fuels have placed human society in serious environmental issues. As a result, it's critical to design efficient and eco-friendly energy production and storage techniques. Porous organic polymers (POPs) are multi-dimensional porous network materials developed through the formation of covalent bonds between different organic building blocks that possess distinct geometries and topologies. POPs have tunable porosities and high surface area making them a good candidate for an effective electrode material in energy storage applications. Herein, we prepared a fully benzoxazine-based porous organic polymers (TPA–DHTP–BZ POP) through sonogashira coupling of dihydroxyterephthalaldehyde (DHPT) and triphenylamine (TPA) containing benzoxazine (BZ) monomers. Firstly, both BZ monomers (TPA-BZ-Br and DHTP-BZ-Ea) were synthesized by three steps, including Schiff base, reduction, and mannich condensation reaction. Finally, the TPA–DHTP–BZ POP was prepared through the sonogashira coupling reaction of brominated monomer (TPA-BZ-Br) and ethynyl monomer (DHTP-BZ-Ea). Fourier transform infrared (FTIR) and solid-state nuclear magnetic resonance (NMR) spectroscopy confirmed the successful synthesis of monomers as well as POP. The porosity of TPA–DHTP–BZ POP was investigated by the N₂ absorption technique and showed a Brunauer–Emmett–Teller (BET) surface area of 196 m² g−¹, pore size 2.13 nm and pore volume of 0.54 cm³ g−¹, respectively. The TPA–DHTP–BZ POP experienced thermal ring-opening polymerization, resulting in poly (TPA–DHTP–BZ) POP having strong inter and intramolecular hydrogen bonds formed by phenolic groups and Mannich bridges, thereby enhancing CO₂ capture and supercapacitive performance. The poly(TPA–DHTP–BZ) POP demonstrated a remarkable CO₂ capture of 3.28 mmol g−¹ and a specific capacitance of 67 F g−¹ at 0.5 A g−¹. Thus, poly(TPA–DHTP–BZ) POP could potentially be used for energy storage and CO₂ capture applications.

Keywords: porous organic polymer, benzoxazine, sonogashira coupling, CO₂, supercapacitor

Procedia PDF Downloads 73

Authors: E.K.K. Agyeman, P. Mousseau, A. Sarda, D. Edelin

Abstract:

The uniform and controlled cooling of hot metals by the circulation of water in canals remains a challenge due to the phase change of the water and the high heat fluxes associated with the phase change. This is because, during the cooling process, the phases are not uniformly distributed along the canals with the liquid phase dominating at the entrances of the canals and the gaseous phase dominating towards the exits. The difference in thermal properties between both phases leads to a heterogeneous temperature distribution in the part being cooled. Slowing down the cooling process is also a challenge due to the high heat fluxes associated with the phase change of water. This study investigates the use of multiple water jets for the controlled and homogenous cooling of hot metal parts and the effect of gravity on the effectiveness of the cooling process with a potential application in the cooling of composite forming moulds. A hole is bored at the centre of a steel block along its length. The jets are generated from the holes of a perforated steel pipe which is placed along the centre of the hole bored in the steel block. The evolution of the temperature with respect to time on the external surface of the steel block is measured simultaneously by thermocouples and an infrared camera. Different jet positions are tested in order to identify the jet placement configuration that ensures the most homogenous cooling of the block while the cooling speed is controlled by an intermittent impingement of the jets. In order to study the effect of gravity on the cooling process, a scenario where the jets are oriented in the opposite direction to that of gravity is compared to one where the jets are aligned in the same direction as gravity. It’s observed that orienting the jets in the direction of gravity reduces the effectiveness of the cooling process on the face of the block facing the impinging jets. This is due to the formation of a deeper pool of water due to the effect gravity and of the curved surface of the canal. This deeper pool of water influences the boiling regime characterized by a slower bubble evacuation when compared to the scenario where the jets are opposed to gravity.

Keywords: cooling speed, gravity, homogenous cooling, jet impingement

Procedia PDF Downloads 121

Authors: Alberto Enrique Molina Lozano, María Teresa Cortés Montañez

Abstract:

Polyaniline (PANI) photoelectrodes were electrochemically synthesized through electrodeposition employing three techniques: chronoamperometry (CA), cyclic voltammetry (CV), and potential pulse (PP) methods. The substrate used for electrodeposition was a fluorine-doped tin oxide (FTO) glass with dimensions of 2.5 cm x 1.3 cm. Subsequently, structural and optical characterization was conducted utilizing Fourier-transform infrared (FTIR) spectroscopy and UV-visible (UV-vis) spectroscopy, respectively. The FTIR analysis revealed variations in the molar ratio of benzenoid to quinonoid rings within the PANI polymer matrix, indicative of differing oxidation states arising from the distinct electropolymerization methodologies employed. In the optical characterization, differences in the energy band gap (Eg) values and positions of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were observed, attributable to variations in doping levels and structural irregularities introduced during the electropolymerization procedures. To assess the charge transfer properties of the PANI photoelectrodes, electrochemical impedance spectroscopy (EIS) experiments were carried out within a 0.1 M sodium sulfate (Na₂SO₄) electrolyte. The results displayed a substantial decrease in charge transfer resistance with the PANI coatings compared to uncoated substrates, with PANI obtained through cyclic voltammetry (CV) presenting the lowest charge transfer resistance, contrasting PANI obtained via chronoamperometry (CA) and potential pulses (PP). Subsequently, the photoactive response of the PANI photoelectrodes was measured through linear sweep voltammetry (LSV) and chronoamperometry. The photoelectrochemical measurements revealed a discernible photoactivity in all PANI-coated electrodes. However, PANI electropolymerized through CV displayed the highest photocurrent. Interestingly, PANI derived from chronoamperometry (CA) exhibited the highest degree of stable photocurrent over an extended temporal interval.

Keywords: PANI, photocurrent, photoresponse, charge separation, recombination

Procedia PDF Downloads 65

Authors: Dong Tang, Yongli Zhao

Abstract:

The study of the microstructure of asphalt is of great importance for the analysis of its macroscopic properties. However, the peculiarities of the chemical composition of the asphalt itself and the limitations of existing direct imaging techniques have caused researchers to face many obstacles in studying the microstructure of asphalt. The advantage of small-angle X-ray scattering (SAXS) is that it allows quantitative determination of the internal structure of opaque materials and is suitable for analyzing the microstructure of materials. Therefore, the SAXS technique was used to study the evolution of microstructures on the nanoscale during asphalt aging. And the reasons for the change in scattering contrast during asphalt aging were also explained with the help of Fourier transform infrared spectroscopy (FTIR). SAXS experimental results show that the SAXS curves of asphalt are similar to the scattering curves of scattering objects with two-level structures. The Porod curve for asphalt shows that there is no obvious interface between the micelles and the surrounding mediums, and there is only a fluctuation of the hot electron density between the two. The Beaucage model fit SAXS patterns shows that the scattering coefficient P of the asphaltene clusters as well as the size of the micelles, gradually increase with the aging of the asphalt. Furthermore, aggregation exists between the micelles of asphalt and becomes more pronounced with increasing aging. During asphalt aging, the electron density difference between the micelles and the surrounding mediums gradually increases, leading to an increase in the scattering contrast of the asphalt. Under long-term aging conditions due to the gradual transition from maltenes to asphaltenes, the electron density difference between the micelles and the surrounding mediums decreases, resulting in a decrease in the scattering contrast of asphalt SAXS. Finally, this paper correlates the macroscopic properties of asphalt with microstructural parameters, and the results show that the high-temperature rutting resistance of asphalt is enhanced and the low-temperature cracking resistance decreases due to the aggregation of micelles and the generation of new micelles. These results are useful for understanding the relationship between changes in microstructure and changes in properties during asphalt aging and provide theoretical guidance for the regeneration of aged asphalt.

Keywords: asphalt, Beaucage model, microstructure, SAXS

Procedia PDF Downloads 80

Authors: Mubarack Ahmed, Gabriele Gradoni, Stephen C. Creagh, Gregor Tanner

Abstract:

High-frequency cables commonly connect modern devices and sensors. Interestingly, the proportion of electric components is rising fast in an attempt to achieve lighter and greener devices. Modelling the propagation of signals through these cable networks in the presence of parameter uncertainty is a daunting task. In this work, we study the response of high-frequency cable networks using both Transmission Line and Quantum Graph (QG) theories. We have successfully compared the two theories in terms of reflection spectra using measurements on real, lossy cables. We have derived a generalisation of the vertex scattering matrix to include non-uniform networks – networks of cables with different characteristic impedances and propagation constants. The QG model implicitly takes into account the pseudo-chaotic behavior, at the vertices, of the propagating electric signal. We have successfully compared the asymptotic growth of eigenvalues of the Laplacian with the predictions of Weyl law. We investigate the nearest-neighbour level-spacing distribution of the resonances and compare our results with the predictions of Random Matrix Theory (RMT). To achieve this, we will compare our graphs with the generalisation of Wigner distribution for open systems. The problem of scattering from networks of cables can also provide an analogue model for wireless communication in highly reverberant environments. In this context, we provide a preliminary analysis of the statistics of communication capacity for communication across cable networks, whose eventual aim is to enable detailed laboratory testing of information transfer rates using software defined radio. We specialise this analysis in particular for the case of MIMO (Multiple-Input Multiple-Output) protocols. We have successfully validated our QG model with both TL model and laboratory measurements. The growth of Eigenvalues compares well with Weyl’s law and the level-spacing distribution agrees so well RMT predictions. The results we achieved in the MIMO application compares favourably with the prediction of a parallel on-going research (sponsored by NEMF21.)

Keywords: eigenvalues, multiple-input multiple-output, quantum graph, random matrix theory, transmission line

Procedia PDF Downloads 173

Authors: Esmeralda Chávez Vargas, M. de la L. Olvera, A. Maldonado

Abstract:

The doping it is believed as follows, at high concentration fluorine in ZnO: F films is incorporated to the lattice by substitution of O-2 ions by F-1 ions; at middle fluorine concentrations, F ions may form interstitials, whereas for low concentrations it is increased the carriers and mobility could be explained by the surface passivation effect of fluorine. ZnO:F thin films were deposited on sodocalcic glass substratesat 425 °C , 450°C, 475 during 8, 12, 15 min from a 0.2 M solution. Doping concentration in the starting solutions was varied, namely, [F]/[F+Zn] = 0, 5, 15, 30, 45, 60, and 90 at. %; solvent composition was varied as well, 100:100; 50:50; 100:50(acetic acid: water: methanol ratios, in volume). In this work it is reported the characterization results of fluorine doped zinc oxide (ZnO:F) thin films deposited by the ultrasonic spray pyrolysis technique, using zinc acetate and ammonium fluorine as Zn an F precursors, respectively. The effect of varying the fluorine concentration in the starting solutions, the solvent composition, and the ageing time of the starting solutions, on the electrical resistivity, optical transmittance, structure and surface morphology was analyzed. In order to have a quantitative evaluation of the ZnO:F thin films for its application as transparent electrodes, the Figure of Merit was estimated from the Haacke´s formula. After a thoroughly study, it can be found that optimal conditions for the deposition of transparent and conductive ZnO:F thin films on sodocalcic substrates, were as follows; substrate temperature: solution molar concentration 0.2, doping concentration in the starting solution of [F]/[Zn]= 60 at. %, (water content)/(acetic acid) in starting solution: [H2O/ CH3OH]= 50:50, substrate temperature: 450 °C. The effects of aging of the starting solution has also been analyzed thoroughly and it has been found a dramatic effect on the electric resistivity of the material, aged by 40 days, show an electrical resitivity as low as 120 Ω/□, with a transmittance around 80% in the visible range. X-ray diffraction spectra show a polycrystalline of ZnO (wurtzite structure) where the amount of fluorine doping affects to preferential orientation (002 plane). Therefore, F introduction in lattice is by the substitution of O-2 ions by F-1 ions. The results show that ZnO:F thin films are potentially adequate for application as transparent conductive oxide in thin film solar cells.

Keywords: TCOs, transparent electrodes, ultrasonic spray pyrolysis, zinc oxide, ZnO:F

Procedia PDF Downloads 503

Authors: Bukunola K. Oguntade, Gareth M. Watkins

Abstract:

The synthesis and characterization of metal-organic frameworks (MOFs) is an area of coordination chemistry which has grown rapidly in recent years. Worldwide there has been growing concerns about future energy supplies, and its environmental impacts. A good number of MOFs have been tested for the adsorption of small molecules in the vapour phase. An important issue for potential applications of MOFs for gas adsorption and storage materials is the stability of their structure upon sorption. Therefore, study on the thermal stability of MOFs upon adsorption is important. The incorporation of two or more transition metals in a coordination polymer is a current challenge for designed synthesis. This work focused on the synthesis, characterization and small molecule adsorption properties of three microporous (one zinc monometal and two bimetallics) complexes involving Cu(II), Zn(II) and 1,2,4,5-benzenetetracarboxylic acid using the ambient precipitation and solvothermal method. The complexes were characterized by elemental analysis, Infrared spectroscopy, Scanning Electron microscopy, Thermogravimetry analysis and X-ray Powder diffraction. The N2-adsorption Isotherm showed the complexes to be of TYPE III in reference to IUPAC classification, with very small pores only capable for small molecule sorption. All the synthesized compounds were observed to contain water as guest. Investigations of their inclusion properties for small molecules in the vapour phase showed water and methanol as the only possible inclusion candidates with 10.25H2O in the monometal complex [Zn4(H2B4C)2.5(OH)3(H2O)]·10H2O but not reusable after a complete structural collapse. The ambient precipitation bimetallic; [(CuZnB4C(H2O)2]·5H2O, was found to be reusable and recoverable from structure collapse after adsorption of 5.75H2O. In addition, Solvo-[CuZnB4C(H2O)2.5]·2H2O obtained from solvothermal method show two cycles of rehydration with 1.75H2O and 0.75MeOH inclusion while structure remains unaltered upon dehydration and adsorption.

Keywords: adsorption, characterization, copper, metal -organic frameworks, zinc

Procedia PDF Downloads 133

Authors: Aleksandra BužArovska, Gordana Bogoeva Gaceva

Abstract:

Biodegradable polymers have received significant scientific attention in tissue engineering (TE) application, in particular their composites consisting of inorganic nanoparticles. In the last 15 years, they are subject of intensive research by many groups, aiming to develop polymer scaffolds with defined biodegradability, porosity and adequate mechanical stability. The most important characteristic making these materials attractive for TE is their biodegradability, a process that could be time controlled and long enough to enable generation of a new tissue as a replacement for the degraded polymer scaffold. In this work poly(L-lactic acid) scaffolds, filled with TiO2 nanoparticles functionalized with oleic acid, have been prepared by thermally induced phase separation method (TIPS). The functionalization of TiO2 nanoparticles with oleic acid was performed in order to improve the nanoparticles dispersibility within the polymer matrix and at the same time to inhibit the cytotoxicity of the nanofiller. The oleic acid was chosen as amphiphilic molecule belonging to the fatty acid family because of its non-toxicity and possibility for mediation between the hydrophilic TiO2 nanoparticles and hydrophobic PLA matrix. The produced scaffolds were characterized with thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and mechanical compression measurements. The bioactivity for bone tissue engineering application was tested in supersaturated simulated body fluid. The degradation process was followed by Fourier transform infrared spectroscopy (FTIR). The results showed anisotropic morphology with elongated open pores (100 µm), high porosity (around 92%) and perfectly dispersed nanofiller. The compression moduli up to 10 MPa were identified independent on the nanofiller content. Functionalized TiO2 nanoparticles induced formation of hydroxyapatite clusters as much as unfunctionalized TiO2. The prepared scaffolds showed properties ideal for scaffold vascularization, cell attachment, growth and proliferation.

Keywords: biodegradation, bone tissue engineering, mineralization, PLA scaffolds

Procedia PDF Downloads 269

Authors: Kishor Chandra Kandpal, Amit Kumar

Abstract:

The Indian Himalaya region harbours approximately 1748 plants of medicinal importance, and as per International Union for Conservation of Nature (IUCN), the 112 plant species among these are threatened and endangered. To ease the pressure on these plants, the government of India is encouraging its in-situ cultivation. The Saussurea costus, Valeriana jatamansi, and Picrorhiza kurroa have also been prioritized for large scale cultivation owing to their market demand, conservation value and medicinal properties. These species are found from 1000 m to 4000 m elevation ranges in the Indian Himalaya. Identification of these plants in the field requires taxonomic skills, which is one of the major bottleneck in the conservation and management of these plants. In recent years, Hyperspectral remote sensing techniques have been precisely used for the discrimination of plant species with the help of their unique spectral signatures. In this background, a spectral library of the above 03 medicinal plants was prepared by collecting the spectral data using a handheld spectroradiometer (325 to 1075 nm) from farmer’s fields of Himachal Pradesh and Uttarakhand states of Indian Himalaya. The Random forest (RF) model was implied on the spectral data for the classification of the medicinal plants. The 80:20 standard split ratio was followed for training and validation of the RF model, which resulted in training accuracy of 84.39 % (kappa coefficient = 0.72) and testing accuracy of 85.29 % (kappa coefficient = 0.77). This RF classifier has identified green (555 to 598 nm), red (605 nm), and near-infrared (725 to 840 nm) wavelength regions suitable for the discrimination of these species. The findings of this study have provided a technique for rapid and onsite identification of the above medicinal plants in the field. This will also be a key input for the classification of hyperspectral remote sensing images for mapping of these species in farmer’s field on a regional scale. This is a pioneer study in the Indian Himalaya region for medicinal plants in which the applicability of hyperspectral remote sensing has been explored.

Keywords: himalaya, hyperspectral remote sensing, machine learning; medicinal plants, random forests

Procedia PDF Downloads 203

Authors: W. A. Gonçalves, E. P. Souza, C. R. Alcântara

Abstract:

The ISCCP-Tracking database offers an opportunity to study physical and morphological characteristics of Convective Systems based on geostationary meteorological satellites. This database contains 26 years of tracking of Convective Systems for the entire globe. Then, Tropical Squall Lines which occur in Brazil are certainly within the database. In this study, we propose a methodology for identification of these systems based on the ISCCP-Tracking database. A physical and morphological characterization of these systems is also shown. The proposed methodology is firstly based on the year of 2007. The Squall Lines were subjectively identified by visually analyzing infrared images from GOES-12. Based on this identification, the same systems were identified within the ISCCP-Tracking database. It is known, and it was also observed that the Squall Lines which occur on the north coast of Brazil develop parallel to the coast, influenced by the sea breeze. In addition, it was also observed that the eccentricity of the identified systems was greater than 0.7. Then, a methodology based on the inclination (based on the coast) and eccentricity (greater than 0.7) of the Convective Systems was applied in order to identify and characterize Tropical Squall Lines in Brazil. These thresholds were applied back in the ISCCP-Tracking database for the year of 2007. It was observed that other systems, which were not Squall Lines, were also identified. Then, we decided to call all systems identified by the inclination and eccentricity thresholds as Linear Convective Systems, instead of Squall Lines. After this step, the Linear Convective Systems were identified and characterized for the entire database, from 1983 to 2008. The physical and morphological characteristics of these systems were compared to those systems which did not have the required inclination and eccentricity to be called Linear Convective Systems. The results showed that the convection associated with the Linear Convective Systems seems to be more intense and organized than in the other systems. This affirmation is based on all ISCCP-Tracking variables analyzed. This type of methodology, which explores 26 years of satellite data by an objective analysis, was not previously explored in the literature. The physical and morphological characterization of the Linear Convective Systems based on 26 years of data is of a great importance and should be used in many branches of atmospheric sciences.

Keywords: squall lines, convective systems, linear convective systems, ISCCP-Tracking

Procedia PDF Downloads 300

Authors: Louise H. Gracioso, Marcela P.G. Baltazar, Ingrid R. Avanzi, Bruno Karolski, Luciana J. Gimenes, Claudio O. Nascimento, Elen A. Perpetuo

Abstract:

Introduction: Higher copper concentrations promote a selection pressure on organisms such as plants, fungi and bacteria, which allows surviving only the resistant organisms to the contaminated site. This selective pressure keeps only the organisms most resistant to a specific condition and subsequently increases their bioremediation potential. Despite the bacteria importance for biosphere maintenance, it is estimated that only a small fraction living microbial species has been described and characterized. Due to the molecular biology development, tools based on analysis 16S ribosomal RNA or another specific gene are making a new scenario for the characterization studies and identification of microorganisms in the environment. News identification of microorganisms methods have also emerged like Biotyper (MALDI / TOF), this method mass spectrometry is subject to the recognition of spectroscopic patterns of conserved and features proteins for different microbial species. In view of this, this study aimed to isolate bacteria resistant to copper present in a Copper Processing Area (Sossego Mine, Canaan, PA) and identifies them in two different methods: Recent (spectrometry mass) and conventional. This work aimed to use them for a future bioremediation of this Mining. Material and Methods: Samples were collected at fifteen different sites of five periods of times. Microorganisms were isolated from mining wastes by culture enrichment technique; this procedure was repeated 4 times. The isolates were inoculated into MJS medium containing different concentrations of chloride copper (1mM, 2.5mM, 5mM, 7.5mM and 10 mM) and incubated in plates for 72 h at 28 ºC. These isolates were subjected to mass spectrometry identification methods (Biotyper – MALDI/TOF) and 16S gene sequencing. Results: A total of 105 strains were isolated in this area, bacterial identification by mass spectrometry method (MALDI/TOF) achieved 74% agreement with the conventional identification method (16S), 31% have been unsuccessful in MALDI-TOF and 2% did not obtain identification sequence the 16S. These results show that Biotyper can be a very useful tool in the identification of bacteria isolated from environmental samples, since it has a better value for money (cheap and simple sample preparation and MALDI plates are reusable). Furthermore, this technique is more rentable because it saves time and has a high performance (the mass spectra are compared to the database and it takes less than 2 minutes per sample).

Keywords: copper mining area, bioremediation, microorganisms, identification, MALDI/TOF, RNA 16S

Procedia PDF Downloads 377

Authors: Erfan Rahimi, Hadi Bahari Far, Mojgan Shikhpour

Abstract:

Background: Urinary tract infection is one of the most common nosocomial infections, especially among women. E. coli is one of the main causes of urinary tract infections and one of the most common antibiotics to fight this bacterium is ampicillin. As conventional antibiotics led to bacterial antibiotic resistance, modification of the pure drugs can address this issue. The aim of this study was to prepare nanofluids containing carbon nanotubes conjugated with ampicillin to improve drug performance and reduce antibiotic resistance. Methods: Multi-walled carbon nanotubes (MWCNTs) were activated with thionyl chloride by reflux system and nanofluids containing antibiotics were prepared by ultrasonic method. The properties of the prepared nano-drug were investigated by general element analysis, infrared spectroscopy, Raman spectroscopy, scanning electron microscopy and transmission electron microscopy. After the treatment of the desired strain with nanofluid, microbial studies were performed to evaluate the antibacterial effects and molecular studies were carried out to measure the expression of the resistance gene AcrAB. Result: We have shown that the antimicrobial effect of ampicillin-functionalized MWCNTs at low concentrations performed better than that of the conventional drug in both resistant and ATCC strains. Also, a decrease in antibiotic resistance of bacteria treated with ampicillin-functionalized MWCNTs compared to the pure drug was observed. Also, ampicillin-functionalized MWCNTs downregulated the expression of AcrAB in treated bacteria. Conclusion: Because carbon nanotubes are capable of destroying the bacterial wall, which provides antibiotic resistance features in bacteria, their usage in the form of nanofluids can make lower dosages (about three times less) than that of the pure drug more effective. Additionally, the expression of the bacterial resistance gene AcrAB decreased, thereby reducing antibiotic resistance and improving drug performance against bacteria.

Keywords: urinary tract infection, antibiotic resistance, carbon nanotube, nanofluid

Procedia PDF Downloads 146

Authors: Federica Laface, Cristina Pedà, Francesco Longo, Francesca de Domenico, Riccardo Minichino, Pierpaolo Consoli, Pietro Battaglia, Silvestro Greco, Teresa Romeo

Abstract:

Plastics pollution represents one of the most important threats to marine biodiversity. In the last decades, different species are investigated to evaluate the extent of the plastic ingestion phenomenon. Even if the cephalopods play an important role in the food chain, they are still poorly studied. The aim of this research was to investigate the plastic ingestion in two commercial cephalopod species from the southern Tyrrhenian Sea: the common octopus, Octopus vulgaris (n=6; mean mantle length ML 10.7 ± 1.8) and the common cuttlefish, Sepia officinalis (n=13; mean ML 13.2 ± 1.7). Plastics were extracted from the filters obtained by the chemical digestion of cephalopods gastrointestinal tracts (GITs), using 10% potassium hydroxide (KOH) solution in a 1:5 (w/v) ratio. Once isolated, particles were photographed, measured, and their size class, shape and color were recorded. A total of 81 items was isolated from 16 of the 19 examined GITs, representing a total occurrence (%O) of 84.2% with a mean value of 4.3 ± 8.6 particles per individual. In particular, 62 plastics were found in 6 specimens of O. vulgaris (%O=100) and 19 particles in 10 S. officinalis (%O=94.7). In both species, the microplastics size class was the most abundant (93.8%). Plastic items found in O. vulgaris were mainly fibers (61%) while fragments were the most frequent in S. officinalis (53%). Transparent was the most common color in both species. The analysis will be completed by Fourier transform infrared (FT-IR) spectroscopy technique in order to identify polymers nature. This study reports preliminary data on plastic ingestion events in two cephalopods species and represents the first record of plastic ingestion by the common octopus. Microplastic items detected in both common octopus and common cuttlefish could derive from secondary and/or accidental ingestion events, probably due to their behavior, feeding habits and anatomical features. Further studies will be required to assess the effect of marine litter pollution in these ecologically and commercially important species.

Keywords: cephalopods, GIT analysis, marine pollution, Mediterranean sea, microplastics

Procedia PDF Downloads 253

Authors: Shahrzad Zolfagharnassab, Abdul Rashid Mohamed Shariff, Reza Ehsani, Hawa Ze Jaffar, Ishak Aris

Abstract:

Ripeness estimation of oil palm fresh fruit is important processes that affect the profitableness and salability of oil palm fruits. The adulthood or ripeness of the oil palm fruits influences the quality of oil palm. Conventional procedure includes physical grading of Fresh Fruit Bunches (FFB) maturity by calculating the number of loose fruits per bunch. This physical classification of oil palm FFB is costly, time consuming and the results may have human error. Hence, many researchers try to develop the methods for ascertaining the maturity of oil palm fruits and thereby, deviously the oil content of distinct palm fruits without the need for exhausting oil extraction and analysis. This research investigates the potential of infrared images (Thermal Images) as a predictor to classify the oil palm FFB ripeness. A total of 270 oil palm fresh fruit bunches from most common cultivar of oil palm bunches Nigresens according to three maturity categories: under ripe, ripe and over ripe were collected. Each sample was scanned by the thermal imaging cameras FLIR E60 and FLIR T440. The average temperature of each bunches were calculated by using image processing in FLIR Tools and FLIR ThermaCAM researcher pro 2.10 environment software. The results show that temperature content decreased from immature to over mature oil palm FFBs. An overall analysis-of-variance (ANOVA) test was proved that this predictor gave significant difference between underripe, ripe and overripe maturity categories. This shows that the temperature as predictors can be good indicators to classify oil palm FFB. Classification analysis was performed by using the temperature of the FFB as predictors through Linear Discriminant Analysis (LDA), Mahalanobis Discriminant Analysis (MDA), Artificial Neural Network (ANN) and K- Nearest Neighbor (KNN) methods. The highest overall classification accuracy was 88.2% by using Artificial Neural Network. This research proves that thermal imaging and neural network method can be used as predictors of oil palm maturity classification.

Keywords: artificial neural network, maturity classification, oil palm FFB, thermal imaging

Procedia PDF Downloads 360

Authors: Srinivasa Reddy Mallampati, Min Hee Park, Soo Mim Cho, Sung Hyeon Yoon

Abstract:

One of the issues of End of Life Vehicles (ELVs) recycling promotion is technology for the appropriate treatment of automotive shredder residue (ASR). Owing to its high heterogeneity and variable composition (plastic (23–41%), rubber/elastomers (9–21%), metals (6–13%), glass (10–20%) and dust (soil/sand) etc.), ASR can be classified as ‘hazardous waste’, on the basis of the presence of heavy metals (HMs), PCBs, BFRs, mineral oils, etc. Considering their relevant concentrations, these metals and plastics should be properly recovered for recycling purposes before ASR residues are disposed of. Brominated flame retardant additives in ABS/HIPS and PVC may generate dioxins and furans at elevated temperatures. Moreover, these BFRs additives present in plastic materials may leach into the environment during landfilling operations. ASR thermal process removes some of the organic material but concentrates, the heavy metals and POPs present in the ASR residues. In the present study, Fe/Ca/CaO nanoparticle assisted ozone treatment has been found to selectively hydrophilize the surface of ABS/HIPS and PVC plastics, enhancing its wettability and thereby promoting its separation from ASR plastics by means of froth flotation. The water contact angles, of ABS/HIPS and PVC decreased, about 18.7°, 18.3°, and 17.9° in ASR respectively. Under froth flotation conditions at 50 rpm, about 99.5% and 99.5% of HIPS in ASR samples sank, resulting in a purity of 98% and 99%. Furthermore, at 150 rpm a 100% PVC separation in the settled fraction, with 98% of purity in ASR, respectively. Total recovery of non-ABS/HIPS and PVC plastics reached nearly 100% in the floating fraction. This process improved the quality of recycled ASR plastics by removing surface contaminants or impurities. Further, a hybrid ball-milling and with Fe/Ca/CaO nanoparticle froth flotation process was established for the recovery of HMs from ASR. After ball-milling with Fe/Ca/CaO nanoparticle additives, the flotation efficiency increased to about 55 wt% and the HMs recovery were also increased about 90% for the 0.25 mm size fractions of ASR. Coating with Fe/Ca/CaO nanoparticles associated with subsequent microbubble froth flotation allowed the air bubbles to attach firmly on the HMs. SEM–EDS maps showed that the amounts of HMs were significant on the surface of the floating ASR fraction. This result, along with the low HM concentration in the settled fraction, was confirmed by elemental spectra and semi-quantitative SEM–EDS analysis. Developed hybrid preferential hazardous plastics and metals separation process from ASR is a simple, highly efficient, and sustainable procedure.

Keywords: end of life vehicles shredder residue, hazardous plastics, nanoparticle froth flotation, separation process

Procedia PDF Downloads 277

Authors: J. W. Choi, S. Y. Cho, H. J. Lee, W. Z. Oh, S. J. Choi

Abstract:

Ionic liquids (ILs), which is alternative to conventional organic solvent, were used for extraction of Cs ions. ILs, as useful environment friendly green solvents, have been recently applied as replacement for traditional volatile organic compounds (VOCs) in liquid/liquid extraction of heavy metal ions as well as organic and inorganic species and pollutants. Thus, Ionic liquids were used for extraction of Cs ions from the liquid radioactive waste. In most cases, Cs ions present in radioactive wastes in very low concentration, approximately less than 1ppm. Therefore, unlike established extraction system the required amount of ILs as extractant is comparatively very small. This extraction method involves cation exchange mechanism in which Cs ion transfers to the organic phase and binds to one crown ether by chelation in exchange of single ILs cation, IL_cation+, transfer to the aqueous phase. In this extraction system showed solid-liquid separation in which the Ionic liquid 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonly)imide (C2mimTf2N) and the crown ether Dicyclohexano-18-crown-6 (DCH18C6) both were used here in very little amount as solvent and as extractant, respectively. 30 mM of CsNO3 was used as simulated waste solution cesium ions. Generally, in liquid-liquid extraction, the molar ratio of CE:Cs+:ILs was 1:5~10:>100, while our applied molar ratio of CE:Cs+:ILs was 1:2:1~10. The quantity of CE and Cs ions were fixed to 0.6 and 1.2 mmol, respectively. The phenomenon of precipitation showed two kinds of separation: solid-liquid separation in the ratio of 1:2:1 and 1:2:2; solid-liquid-liquid separation (3 phase) in the ratio of 1:2:5 and 1:2:10. In the last system, 3 phases were precipitate-ionic liquids-aqueous. The precipitate was verified to consist of Cs+, DCH18C6, Tf2N- based on the cation exchange mechanism. We analyzed precipitate using scanning electron microscopy with X-ray microanalysis (SEM-EDS), an elemental analyser, Fourier transform infrared spectroscopy (FT-IR) and differential scanning calorimetry (DSC). The experimental results showed an easy extraction method and confirmed the composition of solid precipitate. We also obtained information that complex formation ratio of Cs+ to DCH18C6 is 0.88:1 regardless of C2mimTf2N quantities.

Keywords: extraction, precipitation, solid-liquid seperation, ionic liquid, precipitate

Procedia PDF Downloads 420

Authors: Burcu Doymus, Fatma N. Kok, Sakip Onder

Abstract:

Titanium and titanium-based materials are commonly used to replace or regenerate the injured or lost tissues because of accidents or illnesses. Hospital infections and strong bond formation at the implant-tissue interface are directly affecting the success of the implantation as weak bonding with the native tissue and hospital infections lead to revision surgery. The purpose of the presented study is to modify the surface of the titanium substrates with nano/microspheres for local drug delivery and to prevent hospital infections. Firstly, titanium surfaces were silanized with APTES (3-Triethoxysilylpropylamine) following the negatively charged oxide layer formation. Then characterization studies using Scanning Electron Microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) were done on the modified surfaces. Secondly, microspheres/nanospheres were prepared with chitosan that is a natural polymer and having valuable properties such as non-toxicity, high biocompatibility, low allergen city and biodegradability for biomedical applications. Antibiotic (ciprofloxacin) loaded micro/nanospheres have been fabricated using emulsion cross-linking method and have been immobilized onto the titanium surfaces with different immobilization techniques such as covalent bond and entrapment. Optimization studies on size and drug loading capacities of micro/nanospheres were conducted before the immobilization process. Light microscopy and SEM were used to visualize and measure the size of the produced micro/nanospheres. Loaded and released drug amounts were determined by using UV- spectrophotometer at 278 nm. Finally, SEM analysis and drug release studies on the micro/nanospheres coated Ti surfaces were done. As a conclusion, it was shown that micro/nanospheres were immobilized onto the surfaces successfully and drug release from these surfaces was in a controlled manner. Moreover, the density of the micro/nanospheres after the drug release studies was higher on the surfaces where the entrapment technique was used for immobilization. Acknowledgement: This work is financially supported by The Scientific and Technological Research Council Of Turkey (Project # 217M220)

Keywords: chitosan, controlled drug release, nanosphere, nosocomial infections, titanium

Procedia PDF Downloads 125

Authors: Yaw Opoku-Damoah, Run Zhang, Hang Thu Ta, Zhi Ping Xu

Abstract:

Gas therapy is still at an early stage of research and development. Even though most gasotransmitters have proven their therapeutic potential, their handling, delivery, and controlled release have been extremely challenging. This research work employs a versatile nanosystem that is capable of delivering a gasotransmitter in the form of a photo-responsive carbon monoxide-releasing molecule (CORM) for targeted cancer therapy. The therapeutic action was mediated by upconversion nanoparticles (UCNPs) designed to transfer bio-friendly low energy near-infrared (NIR) light to ultraviolet (UV) light capable of triggering carbon monoxide (CO) from a water-soluble amphiphilic manganese carbonyl complex CORM incorporated into a carefully designed lipid drug delivery system. Herein, gaseous CO that plays a role as a gasotransmitter with cytotoxic and homeostatic properties was investigated to instigate cellular apoptosis. After successfully synthesizing the drug delivery system, the ability of the system to encapsulate and mediate the sustained release of CO after light excitation was demonstrated. CO fluorescence probe (COFP) was successfully employed to determine the in vitro drug release profile upon NIR light irradiation. The uptake of nanoparticles enhanced by folates and its receptor interaction was also studied for cellular uptake purposes. The anticancer potential of the final lipid nanoparticle Lipid/UCNPs/CORM/FA (LUCF) was also determined by cell viability assay. Intracellular CO release and a subsequent therapeutic action involving ROS production, mitochondrial damage, and CO production was also evaluated. In all, this current project aims to use in vitro studies to determine the potency and efficiency of a NIR-mediated CORM prodrug delivery system.

Keywords: carbon monoxide-releasing molecule, upconversion nanoparticles, site-specific delivery, amphiphilic manganese carbonyl complex, prodrug delivery system.

Procedia PDF Downloads 112

Authors: M. Jerold, V. Sivasubramanian, A. George, B.S. Ashik, S. S. Kumar

Abstract:

Bioethanol is a sustainable biofuel that can be used alternative to fossil fuels. Today, third generation (3G) biofuel is gaining more attention than first and second-generation biofuel. The more lignin content in the lignocellulosic biomass is the major drawback of second generation biofuels. Algae are the renewable feedstock used in the third generation biofuel production. Algae contain a large number of carbohydrates, therefore it can be used for the fermentation by hydrolysis process. There are two groups of Algae, such as micro and macroalgae. In the present investigation, Macroalgae was chosen as raw material for the production of bioethanol. Two marine algae viz. Ulva Lactuca and Sargassum swartzii were used for the experimental studies. The algal biomass was characterized using various analytical techniques like Elemental Analysis, Scanning Electron Microscopy Analysis and Fourier Transform Infrared Spectroscopy to understand the physio-Chemical characteristics. The batch experiment was done to study the hydrolysis and operation parameters such as pH, agitation, fermentation time, inoculum size. The saccharification was done with acid and alkali treatment. The experimental results showed that NaOH treatment was shown to enhance the bioethanol. From the hydrolysis study, it was found that 0.5 M Alkali treatment would serve as optimum concentration for the saccharification of polysaccharide sugar to monomeric sugar. The maximum yield of bioethanol was attained at a fermentation time of 9 days. The inoculum volume of 1mL was found to be lowest for the ethanol fermentation. The agitation studies show that the fermentation was higher during the process. The percentage yield of bioethanol was found to be 22.752% and 14.23 %. The elemental analysis showed that S. swartzii contains a higher carbon source. The results confirmed hydrolysis was not completed to recover the sugar from biomass. The specific gravity of ethanol was found to 0.8047 and 0.808 for Ulva Lactuca and Sargassum swartzii, respectively. The purity of bioethanol also studied and found to be 92.55 %. Therefore, marine algae can be used as a most promising renewable feedstock for the production of bioethanol.

Keywords: algae, biomass, bioethaol, biofuel, pretreatment

Procedia PDF Downloads 159