Search results for: calcium salt of palm oil fatty acid

Authors: Ravi V. Joat, Pravin S. Bodke, Shradha S. Binani, S. S. Wasnik

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A phase diagram of the Ag2SO4 - CaSO4 (Silver sulphate – Calcium Sulphate) binaries system using conductivity, XRD (X-Ray Diffraction Technique) and DTA (Differential Thermal Analysis) data is constructed. The eutectic reaction (liquid -» a-Ag2SO4 + CaSO4) is observed at 10 mole% CaSO4 and 645°C. Room temperature solid solubility limit up to 5.27 mole % of Ca 2+ in Ag2SO4 is set using X-ray powder diffraction and scanning electron microscopy results. All compositions beyond this limit are two-phase mixtures below and above the transition temperature (≈ 416°C). The bulk conductivity, obtained following complex impedance spectroscopy, is found decreasing with increase in CaSO4 content. Amongst other binary compositions, the 80AgSO4-20CaSO4 gave improved sinterability/packing density.

Keywords: phase diagram, Ag2SO4-CaSO4 binaries system, conductivity, XRD, DTA

Procedia PDF Downloads 629

Authors: Kai-Cheng Yang, Yen-Ling Chen, Er-Chieh Cho, Kuen-Chan Lee

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Titanium dioxide nanomaterials offer superior protection for human skin against the full spectrum of ultraviolet light. However, some literature reviews indicated that it might be associated with adverse effects such as cytotoxicity or reactive oxygen species (ROS) due to their nanoscale. The surface of fullerene is covered with π electrons constituting aromatic structures, which can effectively scavenge large amount of radicals. Unfortunately, fullerenes are poor solubility in water, severe aggregation, and toxicity in biological applications when dispersed in solvent have imposed the limitations to the use of fullerenes. Carboxyfullerene acts as the scavenger of radicals for several years. Some reports indicate that carboxyfullerene not only decrease the concentration of free radicals in ambience but also prevent cells from reducing the number or apoptosis under UV irradiation. The aim of this study is to decorate fullerene –C70-carboxylic acid (C70-COOH) on the surface of titanium dioxide nanoparticles (P25) for the purpose of scavenging ROS during the irradiation. The modified material is prepared through the esterification of C70-COOH with P25 (P25/C70-COOH). The binding edge and structure are studied by using Transmission electron microscope (TEM) and Fourier transform infrared (FTIR). The diameter of P25 is about 30 nm and C70-COOH is found to be conjugated on the edge of P25 in aggregation morphology with the size of ca. 100 nm. In the next step, the FTIR was used to confirm the binding structure between P25 and C70-COOH. There are two new peaks are shown at 1427 and 1720 cm-1 for P25/C70-COOH, resulting from the C–C stretch and C=O stretch formed during esterification with dilute sulfuric acid. The IR results further confirm the chemically bonded interaction between C70-COOH and P25. In order to provide the evidence of scavenging radical ability of P25/C70-COOH, we chose pyridoxine (Vit.B6) and terephthalic acid (TA) to react with singlet oxygen and hydroxyl radicals. We utilized these chemicals to observe the radicals scavenging statement via detecting the intensity of ultraviolet adsorption or fluorescence emission. The UV spectra are measured by using different concentration of C70-COOH modified P25 with 1mM pyridoxine under UV irradiation for various duration times. The results revealed that the concentration of pyridoxine was increased when cooperating with P25/C70-COOH after three hours as compared with control (only P25). It indicates fewer radicals could be reacted with pyridoxine because of the absorption via P25/C70-COOH. The fluorescence spectra are observed by measuring P25/C70-COOH with 1mM terephthalic acid under UV irradiation for various duration times. The fluorescence intensity of TAOH was decreased in ten minutes when cooperating with P25/C70-COOH. Here, it was found that the fluorescence intensity was increased after thirty minutes, which could be attributed to the saturation of C70-COOH in the absorption of radicals. However, the results showed that the modified P25/C70-COOH could reduce the radicals in the environment. Therefore, we expect that P25/C70-COOH is a potential materials in using for antioxidant.

Keywords: titanium dioxide, fullerene, radical scavenging activity, antioxidant

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Authors: Vipin Bhandari, Anupama Singh, Kopal Gupta

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Solid state fermentation, an eminent bioconversion technique for converting many biological substrates into a value-added product, has proven its role in the biotransformation of crops by nutritionally enriching them. Hence, an effort was made for nutritional enhancement of underutilized crops viz. barnyard millet, amaranthus and horse gram based composite flour using SSF. The grains were given pre-treatments before fermentation and these pre-treatments proved quite effective in diminishing the level of antinutrients in grains and in improving their nutritional characteristics. The present study deals with the enhancement of nutritional characteristics of underutilized crops viz. barnyard millet, amaranthus and horsegram based composite flour using solid state fermentation (SSF) as the principle bioconversion technique to convert the composite flour substrate into a nutritionally enriched value added product. Response surface methodology was used to design the experiments. The variables selected for the fermentation experiments were substrate particle size, substrate blend ratio, fermentation time, fermentation temperature and moisture content having three levels of each. Seventeen designed experiments were conducted randomly to find the effect of these variables on microbial count, reducing sugar, pH, total sugar, phytic acid and water absorption index. The data from all experiments were analyzed using Design Expert 8.0.6 and the response functions were developed using multiple regression analysis and second order models were fitted for each response. Results revealed that pretreatments proved quite handful in diminishing the level of antinutrients and thus enhancing the nutritional value of the grains appreciably, for instance, there was about 23% reduction in phytic acid levels after decortication of barnyard millet. The carbohydrate content of the decorticated barnyard millet increased to 81.5% from initial value of 65.2%. Similarly popping and puffing of horsegram and amaranthus respectively greatly reduced the trypsin inhibitor activity. Puffing of amaranthus also reduced the tannin content appreciably. Bacillus subtilis was used as the inoculating specie since it is known to produce phytases in solid state fermentation systems. These phytases remarkably reduce the phytic acid content which acts as a major antinutritional factor in food grains. Results of solid state fermentation experiments revealed that phytic acid levels reduced appreciably when fermentation was allowed to continue for 72 hours at a temperature of 35°C. Particle size and substrate blend ratio also affected the responses positively. All the parameters viz. substrate particle size, substrate blend ratio, fermentation time, fermentation temperature and moisture content affected the responses namely microbial count, reducing sugar, pH, total sugar, phytic acid and water absorption index but the effect of fermentation time was found to be most significant on all the responses. Statistical analysis resulted in the optimum conditions (particle size 355µ, substrate blend ratio 50:20:30 of barnyard millet, amaranthus and horsegram respectively, fermentation time 68 hrs, fermentation temperature 35°C and moisture content 47%) for maximum reduction in phytic acid. The model F- value was found to be highly significant at 1% level of significance in case of all the responses. Hence, second order model could be fitted to predict all the dependent parameters. The effect of fermentation time was found to be most significant as compared to other variables.

Keywords: composite flour, solid state fermentation, underutilized crops, cereals, fermentation technology, food processing

Procedia PDF Downloads 330

Authors: Yu Zhang, Il Kim

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Polypeptides with defined peptide sequences illustrate the power of remarkable applications in drug delivery, tissue engineering, sensing and catalysis. Especially the cyclic polypeptides, the distinctive topological architecture imparts many characteristic properties comparing to linear polypeptides. Here, a facile and highly efficient strategy for the synthesis of linear and cyclic polypeptides is reported using N-heterocyclic carbenes (NHCs)-mediated ring-opening polymerization (ROP) of α-amino acid N-carboxyanhydrides (NCA) in the presence or absence of primary amine initiator. The polymerization proceeds rapidly in a quasi-living manner, allowing access to linear and cyclic polypeptides of well-defined chain length and narrow polydispersity, as evidenced by nuclear magnetic resonance spectrum (1H NMR and 13C NMR spectra) and size exclusion chromatography (SEC) analysis. The cyclic architecture of the polypeptides was further verified by matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectra (MALDI-TOF MS) and electrospray ionization (ESI) mass spectra, as well as viscosity studies. This approach can also simplify workup procedures and make bulk scale synthesis possible, which thereby opens avenues for practical uses in diverse areas, opening up the new generation of polypeptide synthesis.

Keywords: α-amino acid N-carboxyanhydrides, living polymerization, polypeptides, N-heterocyclic carbenes, ring-opening polymerization

Procedia PDF Downloads 168

Authors: Mekhaldi Abdelkader, Bouzned Ahcen, Djibaoui Rachid, Hamoum Hakim

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This study presents an attempt to evaluate the antioxidant and antimicrobial activity of methanolic extract and essential oils prepared from the leaves of sage (Salvia officinalis L.). The content of polyphenols in the methanolic extract of the leaves from Salvia officinalis extract was determined by spectrophoto- metrically, calculated as gallic acid and catechin equivalent. Antioxidant activity was evaluated by free radical scavenging activity using 2,2-diphenylpicryl-1-picrylhydrazyl (DPPH) assay. The plant essential oil and methanol extract were also subjected to screenings for the evaluation of their antioxidant activities using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) test. While the plant essential oil showed only weak antioxidant activities, its methanol extract was considerably active in DPPH (IC50= 37.29µg/ml) test. Appreciable total phenolic content (31.25mg/g) was also detected for the plant methanol extract as gallic acid equivalent in the Folin–Ciocalteu test. The plant was also screened for its antimicrobial activity and good to moderate inhibitions were recorded for its essential oil and methanol extract against most of the tested microorganisms. The present investigation revealed that this plant has rich source of antioxidant properties. It is for this reason that sage has found increasing application in food formulations.

Keywords: antibacterial activity, antioxidant activity, flavonoid, polyphenol, salvia officinalis

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Authors: Nour El Houda Bensiradj, Nafila Zouaghi, Taha Bensiradj

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The pollution of water resources is characterized by the presence of microorganisms, chemicals, or industrial waste. Generally, this waste generates effluents containing large quantities of heavy metals, making the water unsuitable for consumption and causing the death of aquatic life and associated biodiversity. Currently, it is very important to assess the impact of heavy metals in water pollution as well as the processes for treating and reducing them. Among the methods of water treatment and disinfection, we mention the complexation of metal ions using ligands which serve to precipitate and subsequently eliminate these ions. In this context, we are interested in the study of complexes containing heavy metals such as zinc, nickel, and cadmium, which are present in several industrial discharges and are discharged into water sources. We will use the ligands of triethanolamine (TEA) and nitrilotriacetic acid (NTA). The theoretical study is based on molecular modeling, using the density functional theory (DFT) implemented in the Gaussian 09 program. The geometric and energetic properties of the above complexes will be calculated. Spectral properties such as infrared, as well as reactivity descriptors, and thermodynamic properties such as enthalpy and free enthalpy will also be determined.

Keywords: heavy metals, NTA, TEA, DFT, IR, reactivity descriptors

Procedia PDF Downloads 106

Authors: Sophio Kobauri, Temur Kantaria, Nina Kulikova, David Tugushi, Ramaz Katsarava

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Polymeric nanoparticles-based drug delivery systems and therapeutics have a great potential in the treatment of a numerous diseases, due to they are characterizing the flexible properties which is giving possibility to modify their structures with a complex definition over their structures, compositions and properties. Important characteristics of the polymeric nanoparticles (PNPs) used as drug carriers are high particle’s stability, high carrier capacity, feasibility of encapsulation of both hydrophilic and hydrophobic drugs, and feasibility of variable routes of administration, including oral application and inhalation; NPs are especially effective for intracellular drug delivery since they penetrate into the cells’ interior though endocytosis. A variety of PNPs based drug delivery systems including charged and neutral, degradable and non-degradable polymers of both natural and synthetic origin have been developed. Among these huge varieties the biodegradable PNPs which can be cleared from the body after the fulfillment of their function could be considered as one of the most promising. For intracellular uptake it is highly desirable to have positively charged PNPs since they can penetrate deep into cell membranes. For long-lasting circulation of PNPs in the body it is important they have so called “stealth coatings” to protect them from the attack of immune system of the organism. One of the effective ways to render the PNPs “invisible” for immune system is their PEGylation which represent the process of pretreatment of polyethylene glycol (PEG) on the surface of PNPs. The present work deals with constructing PNPs from amino acid based biodegradable polymers – regular poly(ester amide) (PEA) composed of sebacic acid, leucine and 1,6-hexandiol (labeled as 8L6), cationic PEA composed of sebacic acid, arginine and 1,6-hexandiol (labeled as 8R6), and comb-like co-PEA composed of sebacic acid, malic acid, leucine and 1,6-hexandiol (labeled as PEG-PEA). The PNPs were fabricated using the polymer deposition/solvent displacement (nanoprecipitation) method. The regular PEA 8L6 form stable negatively charged (zeta-potential within 2-12 mV) PNPs of desired size (within 150-200 nm) in the presence of various surfactants (Tween 20, Tween 80, Brij 010, etc.). Blending the PEAs 8L6 and 8R6 gave the 130-140 nm sized positively charged PNPs having zeta-potential within +20 ÷ +28 mV depending 8L6/8R6 ratio. The PEGylating PEA PEG-PEA was synthesized by interaction of epoxy-co-PEA [8L6]0,5-[tES-L6]0,5 with mPEG-amine-2000 The stable and positively charged PNPs were fabricated using pure PEG-PEA as a surfactant. A firm anchoring of the PEG-PEA with 8L6/8R6 based PNPs (owing to a high afinity of the backbones of all three PEAs) provided good stabilization of the NPs. In vitro biocompatibility study of the new PNPs with four different stable cell lines: A549 (human), U-937 (human), RAW264.7 (murine), Hepa 1-6 (murine) showed they are biocompatible. Considering high stability and cell compatibility of the elaborated PNPs one can conclude that they are promising for subsequent therapeutic applications. This work was supported by the joint grant from the Science and Technology Center in Ukraine and Shota Rustaveli National Science Foundation of Georgia #6298 “New biodegradable cationic polymers composed of arginine and spermine-versatile biomaterials for various biomedical applications”.

Keywords: biodegradable poly(ester amide)s, cationic poly(ester amide), pegylating poly(ester amide), nanoparticles

Procedia PDF Downloads 124

Authors: Noor Khan, Hira Waris

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This study was conducted on genetically male tilapia (GMT) fry reared in glass aquarium for three months to examine the synergetic effect of essential amino acids (EAA) supplementation on growth, body composition, and enzyme activities. Fish having average body weight of 16.56 ± 0.42g were fed twice a day on artificial feed (20% crude protein) procured from Oryza Organics (commercial feed) supplemented with EAA; methionine (M) and lysine (L) designated as T1 (0.3%M and 2%L), T2 (0.6%M and 4%L), T3 (0.9%M and 6%L) and control without EAA. Significantly higher growth performance was observed in T1, followed by T2, T3, and control. The results revealed that whole-body dry matter and crude protein were significantly higher (p ≤ 0.05) in T3 (0.9% and 6%) feeding fish, while the crude fat was lower (p ≤ 0.05) in a similar group of fish. Additionally, protease, amylase, and lipase activities were also observed maximum (p ≤ 0.05) in response to T3 than other treatments and control. However, the EAA, especially lysine and methionine, were found significantly higher (p ≤ 0.05) in T1 compared to other treatments. Conclusively, the addition of EAA, methionine, and lysine in the feed not only enhanced the growth performance of GMT fry but also improved body proximate composition and essential amino acid profile.

Keywords: genetically male tilapia, body composition, digestive enzyme activities, amino acid profile

Procedia PDF Downloads 148

Authors: Mohamed A. Ghandourah, Walied M. Alarif, Nahed O. Bawakid

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Halogenated cyclic enynes and terpenoids are commonly identified among secondary metabolites of the genus Laurencia. Laurencian acetogenins are entirly C15 non-terpenoid haloethers with different carbocyclic nuclei; a specimen of the Red Sea red alga L. obtusa was investigated for its acetogenin content. The dichloromethane extract of the air-dried red algal material was fractionated on aluminum oxide column preparative thin-layer chromatography. Three new rare C12 acetogenin derivatives (1-3) were isolated from the organic extract obtained from Laurencia obtusa, collected from the territorial Red Sea water of Saudi Arabia. The structures of the isolated metabolites were established by means of spectroscopical data analyses. Examining the isolated compounds in activated human peripheral blood mononuclear cells (PBMC) revealed potent Anti-inflammatory activity as evidenced by inhibition of NFκB and release of other inflammatory mediators like TNF-α, IL-1β and IL-6.

Keywords: Red Sea, red algae, fatty acids, spectroscopy, anti-inflammatory

Procedia PDF Downloads 150

Authors: Ashish Kumar Pathak, Ritika Sharma, Vishal Nath, Sudhir Pratap Singh, Rakesh Tuli

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Litchi is a sub-tropical fruit crop with genotypes bearing delicious juicy fruits with variable seed size (bold to rudimentary size). Small seed size is a desirable trait in litchi, as it increases consumer acceptance and fruit processing. The biochemical activities in mid- stage ovules (e.g. 16, 20, 24 and 28 days after anthesis) determine the fate of seed and fruit development in litchi. Comprehensive ovule-specific transcriptome analysis was performed in two litchi genotypes with contrasting seed size to gain molecular insight on determinants of seed fates in litchi fruits. The transcriptomic data was de-novo assembled in 1,39,608 trinity transcripts, out of which 6,325 trinity transcripts were differentially expressed between the two contrasting genotypes. Differential transcriptional pattern was found among ovule development stages in contrasting litchi genotypes. The putative genes for salicylic acid, jasmonic acid and brassinosteroid pathway were down-regulated in ovules of small-seeded litchi. Embryogenesis, cell expansion, seed size and stress related trinity transcripts exhibited altered expression in small-seeded genotype. The putative regulators of seed maturation and seed storage were down-regulated in small-seed genotype.

Keywords: Litchi, seed, transcriptome, defence

Procedia PDF Downloads 248

Authors: Seid Yimer Abate, Ding-Chi Huang, Yu-Tai Tao

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In this study, charge extraction characteristics at the perovskite/TiO2 interface in the conventional perovskite solar cell is studied by interface engineering. Self-assembled monolayers of phosphonic acids with different chain length and terminal functional group were used to modify mesoporous TiO2 surface to modulate the surface property and interfacial energy barrier to investigate their effect on charge extraction and transport from the perovskite to the mp-TiO2 and then the electrode. The chain length introduces a tunnelling distance and the end group modulate the energy level alignment at the mp-TiO2 and perovskite interface. The work function of these SAM-modified mp-TiO2 varied from −3.89 eV to −4.61 eV, with that of the pristine mp-TiO2 at −4.19 eV. A correlation of charge extraction and transport with respect to the modification was attempted. The study serves as a guide to engineer ETL interfaces with simple SAMs to improve the charge extraction, carrier balance and device long term stability. In this study, a maximum PCE of ~16.09% with insignificant hysteresis was obtained, which is 17% higher than the standard device.

Keywords: Energy level alignment, Interface engineering, Perovskite solar cells, Phosphonic acid monolayer, Tunnelling distance

Procedia PDF Downloads 140

Authors: Pui Shan Wong, Kosuke Tashiro, Satoru Kuhara, Sachiyo Aburatani

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Functional genomics and gene regulation inference has readily expanded our knowledge and understanding of gene interactions with regards to expression regulation. With the advancement of transcriptome sequencing in time-series comes the ability to study the sequential changes of the transcriptome. This method presented here works to augment existing regulation networks accumulated in literature with transcriptome data gathered from time-series experiments to construct a sequential representation of transcription factor activity. This method is applied on a time-series RNA-Seq data set from Escherichia coli as it transitions from growth to stationary phase over five hours. Investigations are conducted on the various metabolic activities in gene regulation processes by taking advantage of the correlation between regulatory gene pairs to examine their activity on a dynamic network. Especially, the changes in metabolic activity during phase transition are analyzed with focus on the pagP gene as well as other associated transcription factors. The visualization of the sequential transcriptional activity is used to describe the change in metabolic pathway activity originating from the pagP transcription factor, phoP. The results show a shift from amino acid and nucleic acid metabolism, to energy metabolism during the transition to stationary phase in E. coli.

Keywords: Escherichia coli, gene regulation, network, time-series

Procedia PDF Downloads 374

Authors: Fatimah Al-Hayazi, Ehteram. A. Noor, Aisha H. Moubaraki

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The inhibitive effect of Securigera securidaca seed extract (SSE) on mild steel corrosion in 1 M HCl solution has been studied by weight loss and electrochemical techniques at four different temperatures. All techniques studied provided data that the studied extract does well at all temperatures, and its inhibitory action increases with increasing its concentration. SEM images indicate thin-film formation on mild steel when corroded in solutions containing 1 g L-1 of inhibitor either at low or high temperatures. The polarization studies showed that SSE acts as an anodic inhibitor. Both polarization and impedance techniques show an acceleration behaviour for SSE at concentrations ≤ 0.1 g L-1 at all temperatures. At concentrations ≥ 0.1 g L-1, the efficiency of SSE is dramatically increased with increasing concentration, and its value does not change appreciably with increasing temperature. It was found that all adsorption data obeyed Temkin adsorption isotherm. Kinetic activation and thermodynamic adsorption parameters are evaluated and discussed. The results revealed an endothermic corrosion process with an associative activation mechanism, while a comprehensive adsorption mechanism for SSE on mild steel surfaces is suggested, in which both physical and chemical adsorption are involved in the adsorption process. A good correlation between inhibitor constituents and their inhibitory action was obtained.

Keywords: corrosion, inhibition of steel, hydrochloric acid, thermodynamic study

Procedia PDF Downloads 103

Authors: Mervet A. El-sherif, Ginat M El-sherif, Kadry H Tolba

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The objective of this study was to determine, identify and investigate the effects of natural antioxidants of licorice and carob. Besides, their effects as powder and antioxidant extracts addition on refined sunflower oil stability as natural antioxidants were evaluated. Total polyphenol contents as total phenols, total carotenoids and total tannins were 353.93mg/100g (gallic acid), 10.62mg/100g (carotenoids) and 83.33mg/100g (tannic acid), respectively in licorice, while in carob, it was 186.07, 18.66 and 106.67, respectively. Polyphenol compounds of the studied licorice and carob extracts were determined and identified by HPLC. The stability of refined sunflower oil (which determined by peroxide value and Rancimat) was increased with increasing the level of polyphenols extracts addition. Also, our study shows the effect of addition of these polyphenols extracts to El-mewled El-nabawy sweets fortified by full cream milk powder (sesames and folia). We found that, licorice and carob as powder and polyphenols extracts were delayed the rancidity of sesame and peanut significantly. That encourages using licorice and carob as powder and polyphenols extracts as a good natural antioxidants source instead of synthetic antioxidants.

Keywords: licorice, carob, natural antioxidants, antioxidant activity, applications

Procedia PDF Downloads 437

Authors: Zeineb Kesentini, Abderrahim El Mahi, Jean Luc Rebiere, Rachid El Guerjouma, Moez Beyaoui, Mohamed Haddar

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Industries’ attention has been drawn to green and sustainable materials as a result of the present energy deficit and environmental damage. Sandwiches formed of auxetic structures made up of periodic cells are also being investigated by industry. Several tests have emphasized the exceptional properties of these materials. In this study, the sandwich's core is a one-cell auxetic core. Among plant fibers, flax fibers are chosen because of their good mechanical properties comparable to those of glass fibers. Poly (lactic acid) (PLA), as a green material, is available from starch, and its production process requires fewer fossil resources than petroleum-based plastics. A polylactic acid (PLA) reinforced with flax fiber filament was employed in this study. The manufacturing process used to manufacture the test specimens is 3D printing. The major drawback of a 100% bio-based material is its low resistance to moisture absorption. In this study, a sandwich based on PLA / flax with an auxetic core is characterized statically for different periods of immersion in water. Bending tests are carried out on the composite sandwich for three immersion time. Results are compared to those of non immersed specimens. It is found that non aged sandwich has the ultimate bending stiffness.

Keywords: auxetic, bending tests, biobased composite, sandwich structure, 3D printing

Procedia PDF Downloads 156

Authors: A. K. Singh, Chhotu Ram

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The present work relates to the corrosivity of distillery effluent and corrosion performance of mild steel and stainless steels SS304L, SS316L, and 2205. The report presents the results and conclusions drawn on the basis of (i) electrochemical polarization tests performed in distillery effluent and laboratory prepared solutions having composition similar to that of the effluent (ii) the surface examination by scanning electron microscope (SEM) of the corroded steel samples. It is observed that pH and presence of chloride, phosphate, calcium, nitrite and nitrate in distillery effluent enhance corrosion, whereas presence of sulphate and potassium inhibits corrosion. Among the materials tested, mild steel is observed to experience maximum corrosion followed by stainless steels SS304L, SS316L, and 2205.

Keywords: corrosion, distillery effluent, electrochemical polarization, steel

Procedia PDF Downloads 410

Authors: Glemarie C. Hermosa, Sheng-Jie You, Chien Chih Hu

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Efficient separation technologies are required for the removal of carbon dioxide from natural gas streams. Membrane-based natural gas separation has emerged as one of the fastest growing technologies, due to the compactness, higher energy efficiency and economic advantages which can be reaped. The removal of Carbon dioxide from gas streams using membrane technology will also give the advantage like environmental friendly process compared to the other technologies used in gas separation. In this study, Polyimide membranes, which are mostly used in the separation of gases, are blended with a new kind of solvent: Deep Eutectic Solvents or simply DES. The three types of DES are used are choline chloride based mixed with three different hydrogen bond donors: Lactic acid, N-methylurea and Urea. The blending of the DESs to Polyimide gave out high permeability performance. The Gas Separation performance for all the membranes involving CO2/CH4 showed low performance while for CO2/N2 surpassed the performance of some studies. Among the three types of DES used the solvent Choline Chloride/Lactic acid exhibited the highest performance for both Gas Separation applications. The values are 10.5 for CO2/CH4 selectivity and 60.5 for CO2/N2. The separation results for CO2/CH4 may be due to the viscosity of the DESs affecting the morphology of the fabricated membrane thus also impacts the performance. DES/blended Polyimide membranes fabricated are novel and have the potential of a low-cost and environmental friendly application for gas separation.

Keywords: deep eutectic solvents, gas separation, polyimide blends, polyimide membranes

Procedia PDF Downloads 314

Authors: Patrícia Branco, Catarina Prista, Helena Albergaria

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Industrial fuel-ethanol fermentations are carried out under non-sterile conditions, which favors the development of microbial contaminants, leading to huge economic losses. Wild yeasts such as Brettanomyces bruxellensis and lactic acid bacteria are the main contaminants of industrial bioethanol fermentation, affecting Saccharomyces cerevisiae performance and decreasing ethanol yields and productivity. In order to control microbial contaminations, the fuel-ethanol industry uses different treatments, including acid washing and antibiotics. However, these control measures carry environmental risks such as acid toxicity and the rise of antibiotic-resistant bacteria. Therefore, it is crucial to develop and apply less toxic and more environmentally friendly biocontrol methods. In the present study, an industrial fuel-ethanol starter, S. cerevisiae Ethanol-Red, was genetically modified to over-express AMPs with activity against fuel-ethanol microbial contaminants and evaluated regarding its biocontrol effect during mixed-culture alcoholic fermentations artificially contaminated with B. bruxellensis. To achieve this goal, S. cerevisiae Ethanol-Red strain was transformed with a plasmid containing the AMPs-codifying genes, i.e., partial sequences of TDH1 (925-963 bp) and TDH2/3 (925-963 bp) and a geneticin resistance marker. The biocontrol effect of those genetically modified strains was evaluated against B. bruxellensis and compared with the antagonistic effect exerted by the modified strain with an empty plasmid (without the AMPs-codifying genes) and the non-modified strain S. cerevisiae Ethanol-Red. For that purpose, mixed-culture alcoholic fermentations were performed in a synthetic must use the modified S. cerevisiae Ethanol-Red strains together with B. bruxellensis. Single-culture fermentations of B. bruxellensis strains were also performed as a negative control of the antagonistic effect exerted by S. cerevisiae strains. Results clearly showed an improved biocontrol effect of the genetically-modified strains against B. bruxellensis when compared with the modified Ethanol-Red strain with the empty plasmid (without the AMPs-codifying genes) and with the non-modified Ethanol-Red strain. In mixed-culture fermentation with the modified S. cerevisiae strain, B. bruxellensis culturability decreased from 5×104 CFU/mL on day-0 to less than 1 CFU/mL on day-10, while in single-culture B. bruxellensis increased its culturability from 6×104 to 1×106 CFU/mL in the first 6 days and kept this value until day-10. Besides, the modified Ethanol-Red strain exhibited an enhanced antagonistic effect against B. bruxellensis when compared with that induced by the non-modified Ethanol-Red strain. Indeed, culturability loss of B. bruxellensis after 10 days of fermentation with the modified Ethanol-Red strain was 98.7 and 100% higher than that occurred in fermentations performed with the non-modified Ethanol-Red and the empty-plasmid modified strain, respectively. Therefore, one can conclude that the S. cerevisiae genetically modified strain obtained in the present work may be a valuable solution for the mitigation of microbial contamination in fuel-ethanol fermentations, representing a much safer and environmentally friendly preservation strategy than the antimicrobial treatments (acid washing and antibiotics) currently applied in fuel-ethanol industry.

Keywords: antimicrobial peptides, fuel-ethanol microbial contaminations, fuel-ethanol fermentation, biocontrol agents, genetically-modified yeasts

Procedia PDF Downloads 102

Authors: Alaa G. M. Osman, Abd-El –Baset M. Abd El Reheem, Khaled Y. Abouelfadl, Usama M. Mahmoud, Mohsen A. Moustafa

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This study aimed to explore new sites of biomarker research and to establish the use of blood parameters in wild fish populations. Four hundred and twenty fish samples were collected from six sites along the whole course of the river Nile, Egypt. The mean values of erythrocytes, thrombocytes, hemoglobin concentration, hematocrit value, and mean corpuscular volume were significantly lower in the blood of Nile tilapia and African catfish collected from downstream (contaminated) compared to upstream sites. In contrast, mean corpuscular hemoglobin and mean corpuscular hemoglobin concentration in the peripheral blood of both fish species significantly increased from upstream to downstream river Nile. The leukocytes count was significantly decreased in contaminated sites compared to upstream area. Hematological variables in the peripheral blood of Oreochromis niloticus niloticus and Clarias gariepinus exhibited significant (p<0.05) correlation with nearly all the detected chemical and physical parameters along the Nile course. In the present study, lower cellular and nuclear areas and cellular and nuclear shape factor were recorded in the erythrocytes of fish collected from downstream compared to those caught from upstream sites. This was confirmed by higher immature ratios of red cells in the blood of fish sampled from downstream river Nile. Karyorrhetic and enucleated erythrocytes were significantly correlated with physiochemical parameters in water samples collected from the same sites is being higher in the blood of fish collected from downstream sites. To see if there was any correlation between fish altered physiological fitness and environmental stress, we measured serum biochemical variables namely; total protein, cholesterol, triglycerides, calcium, chlorides, alkaline phosphatase activity (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), uric acid activity, creatinine, and serum glucose. The level of all the selected biochemical variables in the blood of O. niloticus niloticus and C. gariepinus were recorded to be significantly higher (p<0.05) in downstream sites. According to the present results, nearly all the detected haematological and blood biochemical variables are suitable indicators of contaminant exposure in O. niloticus niloticus and C. gariepinus. Also the detected erythrocytes malformations in blood collected from Nile tilapia and African catfish were proven to be suitable for bio-monitoring aquatic pollution. The results revealed species-specific differences in sensitivities, suggesting that Nile tilapia may serve as a more sensitive test species compared to African catfish.

Keywords: biomarkers, water pollution, blood parameters, river nile, african catfish, nile tilapia

Procedia PDF Downloads 294

Authors: Stephen Eyije Abechi, Casimir Emmanuel Gimba, Zaharaddeen Nasiru Garba, Sani Shamsudeen, David Ebuka Authur

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The mechanisms of corrosion inhibition of mild steel in acid medium using Acalypha chamaedrifolia leaves extract as potential green inhibitor were investigated. Gravimetric (weight loss) technique was used for the corrosion studies. Mild steel coupons of 2cm × 1cm × 0.27 cm dimensions were exposed for varying durations of between 24 to 120 hours, in 1M HCl medium containing a varying concentrations of the leaves extract (0.25g/L, - 1.25g/L). The results show that corrosion rates dropped from a value of 0.49 mgcm-2hr-1 for the uninhibited medium to a value of 0.15 mgcm-2hr-1 for the inhibited medium of 1M HCl in 0.25 g/l of the extract. Values of corrosion inhibition efficiencies of 70.38-85.11% were observed as the concentration of the inhibitor were increased from 0.25g/L, - 1.25g/L. Corrosion Inhibition was found to increase with increase in immersion time and temperature. The magnitude of the Ea indicates that the interaction between the metal surface and the inhibitor was chemisorptions. The Adsorption process fit into the Langmuir isotherm model with a correlation coefficient of 0.97. Evidence from molecular dynamics model shows that Methyl stearate (Line 5) and (3Z, 13Z)-2-methyloctadeca-3,13-dien-1-ol (line 11) were found to have the highest binding energy of -197.69 ± 3.12 and-194.56 ± 10.04 in kcal/mol respectively. The binding energy of these compounds indicates that they would be a very good corrosion inhibitor for mild steel and other Fe related materials.

Keywords: binding energy, corrosion, inhibitor, Langmuir isotherm, mild steel.

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Authors: Shahzadi Laibah Burq, Gina Scarpete Walters

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Piipaash, representing one large family of North American languages, Yuman, is reported as one of the seriously endangered languages in the Salt River Pima-Maricopa Indian Community of Arizona. In a collaborative venture between Arizona State University (ASU) and Salt River Pima-Maricopa Indian Community (SRPMIC), efforts have been made to revitalize and preserve the Piipaash language and its cultural heritage. The present study is one example of several other language documentation and revitalization initiatives that Humanities Lab ASU has taken. This study was approved to receive a “Beyond the lab” grant after the researchers successfully created a Teaching Guide for Early Childhood Piipaash storybook during their time working in the Humanities Lab. The current research is an extension of the previous project and focuses on creating customized teaching materials and tools for the teachers and parents of the students of the Early Enrichment Program at SRPMIC. However, to determine and maximize the usefulness of the teaching materials with regards to their reliability, validity, and practicality in the given context, this research aims to conduct Environmental Analysis and Need Analysis. Environmental Analysis seeks to evaluate the Early Enrichment Program situation and Need Analysis to investigate the specific and situated requirements of the teachers to assist students in building target language skills. The study employs a qualitative methods approach for the collection of the data. Multiple data collection strategies are used concurrently to gather information from the participants. The research tools include semi-structured interviews with the program administrators and teachers, classroom observations, and teacher shadowing. The researchers utilize triangulation of the data to maintain validity in the process of data interpretation. The preliminary results of the study show a need for culturally appropriate materials that can further the learning of students of the target language as well as the culture, i.e., clay pots and basket-making materials. It was found that the course and teachers focus on developing the Listening and Speaking skills of the students. Moreover, to assist the young learners beyond the classroom, the teachers could make use of send-home teaching materials to reinforce the learning (i.e., coloring books, including illustrations of culturally relevant animals, food, and places). Audio language resources are also identified as helpful additional materials for the parents to assist the learning of the kids.

Keywords: indigenous education, materials development, need analysis, piipaash language revitalizaton

Procedia PDF Downloads 91

Authors: Saekil Yun, Sib Sankar Giri, Jin Woo Jun, Hyoun Joong Kim, Sang Guen Kim, Sang Wha Kim, Jung Woo Kang, Se Jin Han, Se Chang Park

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In aquaculture, vaccination is important to control and prevent diseases. In the study, we utilized poly D,L-lactide-co-glycolic acid (PLGA) microparticles (MPs) for encapsulating formalin-killed Aeromonas hydrophila cells. To assess the innate and adaptive immune responses, carps and loaches were used for the experiments. Fish were divided into three groups (A, B, C). Total antigen of 0.1 ml vaccine was adjusted by 2 x 108 CFU and injected via intraperitoneal route. Group A was vaccinated with 0.1 ml of PLGA vaccine, group B was with 0.1 ml of FKC vaccine and group C was with 0.1 ml of sterile PBS. All three groups were challenged with A. hydrophila and challenge dose was lethal dose (LD50). Loaches and carp were then challenged with A. hydrophila at 12 and 20 weeks post vaccination (wpv), and 10 and 14 wpv, respectively, and relative survival rates were calculated. For both fish species, the curve of antibody titer over time was shallower in the PLGA group than the FKC group and the PLGA groups demonstrated higher survival rates at all time-points. In the groups of PLGA-MP, relative mRNA levels of IL-1β, TNF-α, lysozyme C and IgM were significantly upregulated than FKC treated groups. Biodegradable PLGA microparticle vaccine could induce longer immune responses than original FKC vaccines to protect from A. hydrophila infection.

Keywords: PLGA, microparticles, Aeromonas hydrophila, vaccine

Procedia PDF Downloads 274

Authors: M. Şahi̇n, E. Erdem, M. Saçak

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In this study, Na-smectite crystals purificated of bentonite were used after being swelling with benzyltributylammonium bromide (BTBAB) as alkyl ammonium salt. Swelling process was carried out using 0.2 g of BTBAB for smectite of 0.8 g with 4 h of mixing time after investigated conditions such as mixing time, the swelling agent amount. Then, the conductive poly(o-anisidine) (POA)/smectite nanocomposite was prepared in the presence of swollen Na-smectite using ammonium persulfate (APS) as oxidant in aqueous acidic medium. The POA content and conductivity of the prepared nanocomposite were systematically investigated as a function of polymerization conditions such as the treatment time of swollen smectite in monomer solution and o-anisidine/APS mol ratio. POA/smectite nanocomposite was characterized by XRD, FTIR and SEM techniques and was compared separately with components of composite.

Keywords: clay, composite, conducting polymer, poly(o-anisidine)

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Authors: Baba John, Abdullahi Mohammed

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The aim of this research is to compare the analysis of biodegradation on polythene and plastics buried in fadama soil amended with Organic and Inorganic fertilizer. Physico- chemical properties of the samples were determined. Bacteria and Fungi implicated in the biodegradation were identified and enumerated. Physico- chemical properties before the analysis indicated pH range of the samples from 4.28 – 5.80 , While the percentage Organic carbon and Organic matter was highest in cow dung samples with 3.89% and 6.69% respectively. The total Nitrogen percentage was recorded to be highest in Chicken dropping (0.68), while the availability of Phosphorus (P), Sodium (Na), Pottasium (K), and Magnessium (mg) was recorded to be highest in F – soil (Control), with values to be 37ppm, 1.63 Cmolkg-1, 0.35 Cmolkg-1 and 1.18 Cmolkg-1 respectively, except for calcium which was recorded to be highest in Cow dung (5.80 Cmolkg-1). However, physico – chemical properties of the samples after analysis indicated pH range of 4.6 – 5.80, Percentage Organic carbon and Organic matter was highest in Fadama soil mixed with fertilizer, having 0.7% and 1.2% respectively. Total Percentage Nitrogen content was found to be highest (0.56) in Fadama soil mixed with poultry dropping. Availability of Sodium (Na), Pottasium (K), and Calcium (Ca) was recorded to be highest in Fadama Soil mixed with Cow dung with values to be 0.64 Cmolkg-1, 2.07 Cmolkg-1 and 3.36 Cmolkg-1 respectively. The percentage weight loss of polythene and plastic bags after nine months in fadama soil mixed with poultry dropping was 11.9% for polythene and 6.0% for plastics. Weight loss in fadama soil mixed with cow dung was 18.1% for polythene and 4.7% for plastics. Weight loss of polythene and plastic in fadama soil mixed with fertilizer (NPK) was 7.4% for polythene and 3.3% for plastics. While, the percentage weight loss of polythene and plastics after nine months of burial in fadama soil (control) was 3.5% and 0.0% respectively. The bacteria species isolated from Fadama soil, organic and inorganic fertilizers before amendments include: S. aureus, Micrococcus sp, Streptococcus. pyogenes, Psuedomonas aeruginosa Bacillus subtilis and Bacillus cereus. The fungi species include: Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Fusarium sp, Mucor sp Penicillium sp and Candida sp. The bacteria species isolated and characterized after nine months of seeding include: S. aureus, Micrococcus sp, S. pyogenes, P. aeruginosa and B. subtilis. The fungi species are: A. niger A. flavus, A. fumigatus, Mucor sp, Penicillium sp and Fusarium sp. The result of this study indicated that plastic materials can be degraded in the fadama soil irrespective of whether the soil is amended or not. The Period of composting also has a significant impact on the rate at which polythene and plastics are degraded.

Keywords: Fadama, fertilizer, plastic and polythene, biodegradation

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Authors: Magdalena Wilk-Kozubek, Magdalena Rowińska, Krzysztof Rola, Joanna Cybińska

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Leuco dye-based thermochromic systems are classified as intelligent materials because they exhibit thermally induced color changes. Thanks to this feature, they are mainly used as temperature sensors in many industrial sectors. For example, placing a thermochromic material on a chemical reactor may warn about exceeding the maximum permitted temperature for a chemical process. Usually two components, a color former and a developer are needed to produce a system with irreversible color change. The color former is an electron donating (proton accepting) compound such as fluoran leuco dye. The developer is an electron accepting (proton donating) compound such as organic carboxylic acid. When the developer melts, the color former - developer complex is created and the termochromic system becomes colored. Typically, the melting point of the applied developer determines the temperature at which the color change occurs. When the lactone ring of the color former is closed, then the dye is in its colorless state. The ring opening, induced by the addition of a proton, causes the dye to turn into its colored state. Since the color former and the developer are often solid, they can be incorporated into polymer films to facilitate their practical use in industry. The objective of this research was to fabricate a leuco dye-based termochromic system that will irreversibly change color after reaching the temperature of 100°C. For this purpose, benzofluoran leuco dye (as color former) and phenoxyacetic acid (as developer with a melting point of 100°C) were introduced into the polymer films during the drop casting process. The film preparation process was optimized in order to obtain thin films with appropriate properties such as transparency, flexibility and homogeneity. Among the optimized factors were the concentration of benzofluoran leuco dye and phenoxyacetic acid, the type, average molecular weight and concentration of the polymer, and the type and concentration of the surfactant. The selected films, containing benzofluoran leuco dye and phenoxyacetic acid, were combined by mild heat treatment. Structural characterization of single and combined films was carried out by FTIR spectroscopy, morphological analysis was performed by optical microscopy and SEM, phase transitions were examined by DSC, color changes were investigated by digital photography and UV-Vis spectroscopy, while emission changes were studied by photoluminescence spectroscopy. The resulting thermochromic system is colorless at room temperature, but after reaching 100°C the developer melts and it turns irreversibly pink. Therefore, it could be used as an additional sensor to warn against boiling of water in power plants using water cooling. Currently used electronic temperature indicators are prone to faults and unwanted third-party actions. The sensor constructed in this work is transparent, thanks to which it can be unnoticed by an outsider and constitute a reliable reference for the person responsible for the apparatus.

Keywords: color developer, leuco dye, thin film, thermochromism

Procedia PDF Downloads 103

Authors: A. T. Laiche, M. L. Tlil, Benine B., S. Bechoua

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The aim of this study is to isolate and select, from camel milk from El-Oued region in Algeria, a strains of lactic acid bacteria and possessing probiotic properties ; and to evaluate their potential effect on intestinal disorders in Wistar ratsmThe results relating to the selection of probiotic strains confirms that the Thermophilic streptococcus exhibits the best probiotic activity performance, with a resistance important to different degrees of pH and to bile salts, and a remarkable antibacterial activity and resistance to antibiotics compared to the other four isolated strains. In the in vivo study, diseases are induced in rats at the level of the digestive system, it was reported that the administration of Escherichia coli and castor oil caused an intestinal disorders. The microscopic observation of the histological section of the intestine showed a damaged intestinal structure and some symptoms of its irritation, including a decrease in the height of the villi and the presence of others destroyed cells, and after treatment with Streptococcus thermophilus, the microscopic observation of the cut of the histological section of the intestine showed almost complete disappearance of the mentioned symptoms, The dosage of the hematological parameters by complete blood count (CBC) is in agreement with the results of the histological sections.

Keywords: camel milk, probiotic, pathogenic bacteria, intestinal disorders, lactic acid bacteria

Procedia PDF Downloads 161

Authors: Faiz Khan Mohammad, Saumya Ray Chaudhari, Raghunathan Rengaswamy, Swagatika Sahoo

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Cholera caused by pathogenic gut bacteria Vibrio Cholerae (VC), is a major health problem in developing countries. Different strains of VC exhibit variable responses subject to different extracellular medium (Nag et al, Infect Immun, 2018). In this study, we present a new approach to model the variable VC responses in mono- and co-cultures, subject to continuously changing growth medium, which is otherwise difficult via simple FBA model. Nine VC strain and seven E. coli (EC) models were assembled and considered. A continuously changing medium is modelled using a new iterative-based controlled medium technique (ITC). The medium is appropriately prefixed with the VC model secretome. As the flux through the bacteria biomass increases secretes certain by-products. These products shall add-on to the medium, either deviating the nutrient potential or block certain metabolic components of the model, effectively forming a controlled feed-back loop. Different VC models were setup as monoculture of VC in glucose enriched medium, and in co-culture with VC strains and EC. Constrained to glucose enriched medium, (i) VC_Classical model resulted in higher flux through acidic secretome suggesting a pH change of the medium, leading to lowering of its biomass. This is in consonance with the literature reports. (ii) When compared for neutral secretome, flux through acetoin exchange was higher in VC_El tor than the classical models, suggesting El tor requires an acidic partner to lower its biomass. (iii) Seven of nine VC models predicted 3-methyl-2-Oxovaleric acid, mysirtic acid, folic acid, and acetate significantly affect corresponding biomass reactions. (iv) V. parhemolyticus and vulnificus were found to be phenotypically similar to VC Classical strain, across the nine VC strains. The work addresses the advantage of the ITC over regular flux balance analysis for modelling varying growth medium. Future expansion to co-cultures, potentiates the identification of novel interacting partners as effective cholera therapeutics.

Keywords: cholera, vibrio cholera El. tor, vibrio cholera classical, acetate

Procedia PDF Downloads 166

Authors: Aguasanta Miguel Sarmiento, José Miguel Dávila, María Luisa de la Torre

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Acid mine drainage (AMD) is an acidic leachate with high levels of metals and sulphates in solution, which seriously affects the durability and strength of metallic materials used in the construction of structural and mechanical components. This paper presents the results of the evolution over time of the reduction in tensile strength and defects in AISI 304 stainless steel in contact with acid mine drainage. For this purpose, a total of 30 bars with a diameter of 8 mm and a length of 14 cm were placed transversely in the course of a stream contaminated by AMD from the sulphide mines of the Iberian Pyritic Belt (SW Spain). This stream has average pH values of 2.6, a potential of 660 mV, and average concentrations of 12 g/L of sulphates, 1.2 g/L of Fe, 191 mg/L of Zn, etc. Every two months of exposure, 6 stainless steel bars were extracted from the acid stream. They were subjected to surface roughness analysis carried out with the help of Mitutoyo Surftest SJ-210 surface roughness tester. The analysis was carried out at three different points on 5 specimens from each series. The average reading of each parameter is calculated in order to ensure the accuracy of the measurements and the surface coverage. Arithmetic mean roughness value (Ra), mean roughness depth (Rz), and root mean square roughness (Rq) were measured. Five specimens from each series were statically tensile tested using universal equipment (Servosis ME 403 of 200kN). The specimens were clamped at their ends with two grips for cylindrical sections, and the tensile force was applied at a constant speed of 0.5 kN/s, according to the requirements of standard UNE-EN ISO 6892-1: 2020. To determine the modulus of elasticity, limits close to 15% and 55% of the maximum load were used, depending on the course of each test. Field Emission Scanning Electron Microscopy (FESEM) was used to observe corrosion products and defects generated by exposure to AMD. Energy dispersive X-ray spectrometry (EDS) was used to analyse the chemical composition of the corrosion products formed. For this purpose, small pieces were cut from the resulting specimens, cleaned, and embedded in epoxy resin. The results show that after only 5 months of exposure of AISI 304 stainless steel to the mining environment, the surface roughness increases significantly, with average depths almost 6 times greater than the initial one. Cracks are observed on the surface of the material, which increases in size with the time of exposure. A large number of grains with a composition of more than 57% Pb and 16% Sn can be observed inside these cracks. Tensile tests show a reduction in the resistance of this material after only two months of exposure. The results show the serious problems that would result from the use of this material for the use of mechanical components in a sulphide mining environment, not only because of the significant reduction in the lifetime of such components, but also because of the implications for human safety.

Keywords: acid mine drainage, corrosion, mechanical properties, stainless steel

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Authors: Emie A. Salamangkit-Mirasol, Rinlee Butch M. Cervera

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Rice hull or rice husk (RH) is an agricultural waste obtained from milling rice grains. Since RH has no commercial value and is difficult to use in agriculture, its volume is often reduced through open field burning which is an environmental hazard. In this study, amorphous nanosilica from Philippine waste RH was prepared via acid precipitation method. The synthesized samples were fully characterized for its microstructural properties. X-ray diffraction pattern reveals that the structure of the prepared sample is amorphous in nature while Fourier transform infrared spectrum showed the different vibration bands of the synthesized sample. Scanning electron microscopy (SEM) and particle size analysis (PSA) confirmed the presence of agglomerated silica particles. On the other hand, transmission electron microscopy (TEM) revealed an amorphous sample with grain sizes of about 5 to 20 nanometer range and has about 95 % purity according to EDS analyses. The elemental mapping also suggests that leaching of rice hull ash effectively removed the metallic impurity such as potassium element in the material. Hence, amorphous nanosilica was successfully prepared via a low-cost acid precipitation method from Philippine waste rice hull. In addition, initial electrode performance of the synthesized samples as an anode material in Lithium Battery have been investigated.

Keywords: agricultural waste, anode material, nanosilica, rice hull

Procedia PDF Downloads 284

Authors: Gemma A. Gruyal

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Plants can contain a wide variety of substances with antioxidative properties which are associated to important health benefits. These positive health effects are of great importance at a time when the environment is laden with many toxic substances. Five selected herbal plants namely, Mimosa pudica, Phyllanthus niruri, Ceiba pentandra, Eleusine polydactyla and Trema amboinensis, were chosen for the experiment to investigate their total phenolics content and antioxidant activities using ABTS radical cation decolorization power, and ferric reducing antioxidant power. The total phenolic content of each herbal plants ranges from 0.84 to 42.59 mg gallic acid equivalent/g. The antioxidant activity in the ABTS radical cation decolorization power varies from 0.005 to 0.362 mg trolox equivalent/g and the FRAP ranges from 0.30 to 28.42 mg gallic acid equivalent/g. Among the five medicinal plants, Mimosa pudica has been an excellent performer in terms of the 3 parameters measured; it is followed by Phyllanthus niruri. The five herbal plants do not have equivalent antioxidant power. The relative high values for M. pudica and P. niruri supports the medicinal value of both plants. The total phenolics, ABTS and FRAP correlate strongly with one another.

Keywords: ABTS, FRAP, Leaf extracts, phenol

Procedia PDF Downloads 436