Search results for: water soaking properties

Authors: Nathalia Florencia Barros Azeredo, Josué Martins Gonçalves, Pamela De Oliveira Rossini, Koiti Araki, Lucio Angnes

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This work demonstrates the electroanalysis of uric acid (UA) at very low working potential (0 V vs Ag/AgCl) directly in body fluids such as saliva and sweat using electrodes modified with mixed -Ni0.75Zn0.25(OH)2 nanoparticles exhibiting stable electrocatalytic responses from alkaline down to weakly acidic media (pH 14 to 3 range). These materials were prepared for the first time and fully characterized by TEM, XRD, and spectroscopic techniques. The electrochemical properties of the modified electrodes were evaluated in a fast and simple procedure for uric acid analyses based on cyclic voltammetry and chronoamperometry, pushing down the detection and quantification limits (respectively of 2.3*10-8 and 7.6*10-8 mol L-1) with good repeatability (RSD = 3.2% for 30 successive analyses pH 14). Finally, the possibility of real application was demonstrated upon realization of unexpectedly robust and sensitive modified FTO (fluorine doped tin oxide) glass and screen-printed sensors for measurement of uric acid directly in real saliva and sweat samples, with no significant interference of usual concentrations of ascorbic acid, acetaminophen, lactate and glucose present in those body fluids (Fig. 1).

Keywords: nickel hydroxide, mixed catalyst, uric acid sensors, biofluids

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Authors: Sadek Salah

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The determination of the strength characteristics of waste materials is essential when evaluating the stability of waste fills during initial placement and at the time of closure and rehabilitation of the landfill. Significant efforts, mostly experimental, have been deployed to date in attempts to quantify the mechanical properties of municipal wastes various stages of decomposition. Even though the studies and work done so far have helped in setting baseline parameters and characteristics for waste materials, inherent concerns remain as to the scalability of the findings between the laboratory and the field along with questions as to the suitability of the actual test conditions. These concerns are compounded by the complexity of the problem itself with significant variability in composition, placement conditions, and levels of decay of the various constituents of the waste fills. A complimentary, if not necessarily an alternative approach is to rely on field observations of behavior and instability of such materials. This paper describes an effort at obtaining relevant shear strength parameters from back-analyses of failures which have been observed at a major un-engineered waste fill along the Mediterranean shoreline. Results from the limit-equilibrium failure back-analyses are presented and compared to results from laboratory-scale testing on comparable waste materials.

Keywords: solid waste, shear strength, landfills, slope stability

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Authors: Subrata Kar, Banani Kundu, Papiya Nandy, Ruma Basu, Sukhen Das

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Natural montmorilollite clay is a common ingredient in pharmaceutical products, both as excipients and active support; hence considered as suitable candidate for Drug Delivery System. In this work, cationic detergent CTAB is used to increase the interlayer spacing of Na+-Montmoriollite clay to intercalate curcumin and methotrexate. Methotrexate is a folic acid antagonist, anti-proliferative and immunosuppressive agent; while curcumin is a bioactive constituent of rhizomes of Curcuma longa, possessing remarkable chemo-preventive and anti-inflammatory properties. The resultant inorganic-organic hybrids are characterized by X-ray diffraction (XRD), Infrared spectroscopy (FTIR) and Thermo Gravimetric Analysis (TGA) to confirm successful intercalation of curcumin and Methotrexate within clay layers. Pharmaceutical investigation of the hybrids is explored by studying the drug loading (%), encapsulation efficiency and release kinetics. Finally in-vitro studies are performed using cancer cells to find the effect of released curcumin to improve the sensitivity of clay bound methotrexate to ameliorate cell death compared to their effectiveness when used without the inorganic aluminosilicate vehicle.

Keywords: montmorillonite, methotrexate, curcumin, loading efficiency, release kinetics, anticancer activity

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Authors: Yusuf Kaygısız, Necmetti̇n Maraşlı

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Aluminum alloys are produced and used at various areas of industry and especially in the aerospace industry. The advantages of these alloys over traditional iron-based alloys are lightweight, corrosion resistance, and very good thermal and electrical conductivity. The aim of this work is to experimentally investigate the effect of growth rates on the eutectic spacings (λ), microhardness, tensile strength and electrical resistivity in Al–30wt.%Cu–6wt.%Mg eutectic alloy. Al–Cu–Mg eutectic alloy was directionally solidified at a constant temperature gradient (G=8.55 K/mm) with different growth rates, 9.43 to 173.3 µm/s by using a Bridgman-type furnace. The dependency of microstructure, microhardness, tensile strength and electrical resistivity for directionally solidified the Al-Cu-Mg eutectic alloy were investigated. Eutectic microstructure is consisting of regular Al2CuMg lamellar and Al2Cu rod phases with in the α (Al) solid solution matrix. The lamellar eutectic spacings were measured from transverse sections of the samples. It was found that the value of microstructures decrease with the increase the value the growth rates. The microhardness, tensile strength and electrical resistivity of the alloy also were measured from sample and relationships between them were experimentally analyzed by using regression analysis. According to present results, values tensile strength and electrical resistivity increase with increasing growth rates.

Keywords: directional solidification, aluminum alloys, microstructure, electrical properties, hardness test

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Authors: M. L. Ibrahim, A. Abdulhamid

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A surface active molecule synthesized by a rhizobacterial strain Bacillus lentus isolated from Cajanus cajan was investigated. The bioemulsifier was extracted, purified and partially characterized using standard methods. Surface properties of the bioemulsifier were determined by studying the emulsification index, solubility test and stability studies. Partial purification of the bioemulsifier was carried out using FT-IR analysis, Silica-gel column chromatography and thin layer chromatography. GC-MS analysis was carried out to detect the composition and mass of the lipids and esters. The isolate showed an emulsifying activity of 57% and surface activity of 36mm. The stability studies revealed that the bioemulsifier had better stability at temperature of 70oC, 8% pH and 8% NaCl concentration. FT-IR indicated the bioemulsifier to contain peptide and aliphatic chain, TLC revealed the compound to be ninhydrin positive and Column chromatography showed the presence of three amino acids namely; glutamine, valine and cysteine. GC-MS indicated the lipid moiety to contain aliphatic chain ranging from C9-C16 and two major peaks of 1,2-benzenedicarboxylic acid diethyl octyl ester. Therefore, surface active agent from Bacillus lentus can be used effectively in a wide range of applications such as in MEOR and in the biosynthesis of plasticizers for industrial uses.

Keywords: Bacillus lentus, bioemulsifiers, phthalic acid ester, Rhizosphere

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Authors: Julide Hizal Yucesoy, Batuhan Yardimci, Aysem Arda, Resat Apak

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Humic substances produce reactive oxygene species such as hydroxyl, phenoxy and superoxide radicals by oxidizing in a wide pH and reduction potential range. Hydroxyl radicals, produced by reducing agents such as antioxidants and/or peroxides, attack on salicylate probe, and form 2,3-dihydroxybenzoate, 2,4-dihydroxybenzoate and 2,5-dihydroxybenzoate species. These species are quantitatively determined by using HPLC Method. Humic substances undergo photodegradation by UV radiation. As a result of their antioxidant properties, they produce hydroxyl radicals. In the presence of salicylate probe, these hydroxyl radicals react with salicylate molecules to form hydroxylated products (dihidroxybenzoate isomers). In this study, humic acid was photodegraded in a photoreactor at 254 nm (400W), formed hydroxyl radicals were caught by salicylate probe. The total concentration of hydroxylated salicylate species was measured by using spectrophotometric CUPRAC Method. And also, using results of time dependent experiments, kinetic of photohydroxylation was determined at different pHs. This method has been applied for the first time to measure the concentration of hydroxylated products. It allows to achieve the results easier than HPLC Method.

Keywords: CUPRAC method, humic acid, photohydroxylation, salicylate probe

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Authors: S. Asreazad

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This paper presents the results that the soil volumetric strain and shear strength are closely related to the confining stress and initial matric suction under constant water content testing on the specimens of unsaturated sand with clay and silt fines contents. The silty sand specimens reached their peak strength after a very small axial strain followed by a post-peak softening towards an ultimate value. The post-peak drop in stress increased by an increment of the suction, while there is no peak strength for clayey sand specimens. The clayey sand shows compressibility and possesses ductile stress-strain behaviour. Shear strength increased nonlinearly with respect to matric suction for both soil types. When suction exceeds a certain range, the effect of suction on shear strength increment weakens gradually. Under the same confining stress, the dilatant tendencies in the silty sand increased under lower values of suction and decreased for higher suction values under the same confining stress. However, the amount of contraction increased with increasing initial suction for clayey sand specimens.

Keywords: unsaturated soils, silty sand, clayey sand, triaxial test

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Authors: Bashir Abubakar Abdulkadir, Anita Ramli, Lim Jun Wei, Yoshimitsu Uemura

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In this study, the ZnO/MCM-22 catalyst with different ZnO loading were prepared using conventional wet impregnation process and the catalyst activity was tested for biodiesel production from Jatropha oil. The effects of reaction parameters with regards to catalyst activity were investigated. The synthesized catalysts samples were then characterized by X-ray diffraction (XRD) for crystal phase, Brunauer–Emmett–Teller (BET) for surface area, pore volume and pore size, Field Emission Scanning electron microscope attached to energy dispersive x-ray (FESEM/EDX) for morphology and elemental composition and TPD (NH3 and CO2) for basic and acidic properties of the catalyst. The XRD spectra couple with the EDX result shows the presence of ZnO in the catalyst confirming the positive intercalation of the metal oxide into the mesoporous MCM-22. The synthesized catalyst was confirmed to be mesoporous according to BET findings. Also, the catalysts can be considered as a bifunctional catalyst based on TPD outcomes. Transesterification results showed that the synthesized catalyst was highly efficient and effective to be used for biodiesel production from low grade oil such as Jatropha oil and other industrial application where the high fatty acid methyl ester (FAMEs) yield was achieved at moderate reaction conditions. It was also discovered that the catalyst can be used more than five (5) runs with little deactivation confirming the catalyst to be highly active and stable to the heat of reaction.

Keywords: MCM-22, synthesis, transesterification, ZnO

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Authors: Milica Z. Karadzic, Lidija R. Jevric, Sanja Podunavac-Kuzmanovic, Strahinja Z. Kovacevic, Anamarija I. Mandic, Katarina Penov-Gasi, Andrea R. Nikolic, Aleksandar M. Okljesa

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In this study, a set of 29 newly synthesized steroid derivatives were investigated using reversed-phase high-performance liquid chromatography (RP-HPLC) as a first step in preselection of drug candidates. This analysis presents an experimental determination of chromatographic lipophilicity, and it was conducted to obtain physicochemical characterization of these molecules. As the most widely used bonded phases in RP-HPLC, octadecyl (C18) and octyl (C8) were used. Binary mixtures of water and acetonitrile or methanol were used as mobile phases. Obtained results were expressed as retention factor values logk and they were correlated with logP values. The results showed that both columns provide good estimations of the chromatographic lipophilicity of the molecules included in this study. This analysis was conducted in order to characterize newly synthesized steroid derivatives for further investigation regarding their antiproliferative and antimicrobial activity. This article is based upon work from COST Action (CM1306), supported by COST (European Cooperation in Science and Technology).

Keywords: antiproliferative activity, chromatographic lipophilicity, liquid chromatography, steroids

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Authors: Chi-Wai Kan, Yanming Wang, Alan Yiu-Lun Tang, Cheng-Hao Lee Lee

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Dyeing of polyester/cotton blend fabrics in various polyester/cotton percentages (32/68, 40/60 and 65/35) was investigated using (poly(ethylene glycol), PEG) based reverse-micelle. High energy disperse dyes and warm type reactive dyes were encapsulated and applied on polyester/cotton blend fabrics in a one bath one step dyeing process. Comparison of reverse micellar-based and aqueous-based (water-based) dyeing was conducted in terms of colour reflectance. Experimental findings revealed that the colour shade of the dyed fabrics in reverse micellar non-aqueous dyeing system at a lower dyeing temperature of 98°C is slightly lighter than that of conventional aqueous dyeing system in two-step process (130oC for disperse dyeing and 70°C for reactive dyeing). The exhaustion of dye in polyester-cotton blend fabrics, in terms of colour reflectance, were found to be highly fluctuated at dyeing temperature of 98°C.

Keywords: one-bath dyeing, polyester/cotton blends, disperse/reactive dyes, reverse micelle

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Authors: Kyoungok Jung, Chang Hong Bak, Gyeong Cheon Jo, Jin-Baek Kim

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Nanostructured arrays have drawn extensive attention because of their unique properties resulting from nanoscale features. However, it is difficult to achieve uniform and freestanding 1D nanostrcutures over a large area. Here, a simple and novel method was developed for fabrication of universal nanoporous templates for high-density nanostructure arrays, by combining self-assembly of a Si-containing block copolymer with a bilayer lithography system. We introduced a dually responsive photoresist bottom layer into which the nanopatterns of block copolymer are transferred by oxygen reactive ion etching. Because the dually responsive layer becomes cross-linked by heating, it can be used as a hard template during the etching process. It becomes soluble again by chain scission upon exposure to light. Therefore, it can be easily removed by the lift-off process. The template was applicable to the various conducting substrates due to the compatibility of the photoresist with a wide range of substrates and was used in electrodeposition for well-aligned and high-density inorganic and organic nanoarrays. We successfully obtained vertically aligned and highly ordered gold nanorods and polypyrrole dots on the substrate without aggregation, and these arrays did not collapse after removing the dually responsive templates by the simple lift-off process.

Keywords: block copolymer, dually responsive, nanostructure, photoresist

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Authors: Esteban Hincapie

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The growing climate change, global warming and population growth have contributed to the energy crisis, aggravated by the generation of organic solid waste, as a material with high energy potential. From the context of waste generation in the Metropolitan Area of the Aburrá Valley, was evaluated the potential of energy content in organic solid waste generated in La Herradura housing complex, through anaerobic digestion process in batch reactors, with mixtures of substrate, water and inoculum 1: 3: 0.2 and 1: 3: 0, reaching a total biogas production of 0,2 m³/Kg y 0,14 m³/Kg respectively, in a period of 38 days under temperature conditions of 24°C. The volume of biogas obtained was equivalent to the monthly consumption of natural gas for 75 apartments or 1.856 Kw of electric power. For the Metropolitan Area of the Aburrá Valley, a production of 7.152Kw of electric power was estimated for a month, from the treatment of 22.319 tons of organic solid waste that would not be taken to the landfill. The results indicate that the treatment of organic waste from anaerobic digestion is a sustainable option to reduce pollution, contribute to the production of alternative energies and improve the efficiency of urban metabolism.

Keywords: alternative energies, anaerobic digestion, solid waste, sustainable construction, urban metabolism, waste management

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Authors: Hafiz Khuram Wasim Aslam, Muhammad Saeed, Azam Shakeel, Muhammad Inam Ur Raheem, Moazzam Rafiq Khan, Muhammad Atif Randhawa

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Inulin is significant ingredient used in food industry that functions technologically as a fat replacer often without compromising taste and texture. In this study inulin was extracted from the chicory roots and the effect of inulin addition as a fat replacer on the physiochemical, microbiological and sensory properties of non-fat yogurt was investigated. The supplementation of chicory inulin reduced the magnitude of firmness in comparison with non-inulin ¬supplemented non-fat yoghurt. Higher values of acidity were observed due to the more microbial fermentation in the inulin containing yogurt as compared to non-inulin yogurt and were in the range of 0.56 to 0.75 during storage days. Syneresis in control sample increased from 43.9% to 47.9% during the storage study. However inulin addition at different treatment enhanced syneresis from 44.5% to 47.6%. Inulin addition at various concentrations caused an increase in the TPC due to its probiotic effect. No effects of inuline addition on fat and protein contents were observed. Non-fat yoghurt supplemented with inulin demonstrated sensory behavior better than that of the control yoghurt. The most important effect of the addition of inulin to non-fat yoghurt is an increase in the sensory attributes appearance, body and texture, taste and mouth feel, overall acceptability. On an average, yoghurt supplemented with 1 to 2% inulin was better in overall acceptance as compared to control yoghurt.

Keywords: inulin, fat replacer, yoghurt, sensory evaluation, low fat

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Authors: Rahimullah Habibzai

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To achieve a sustainable concrete industry, reduce exploitation of the natural aggregate resources, and mitigate waste concrete environmental burden, one way is to use recycled concrete aggregate. The utilization of low-quality fine aggregate inclusively recycled concrete sand that is produced from crushing waste concrete recently has become a popular and challenging topic among researchers nowadays. This study provides a scientific base for promoting the application of concrete waste as fine aggregate in producing concrete by conducting a comprehensive laboratory program. The mechanical properties of mortar made from recycled concrete fine aggregate (RCFA), that is produced by pulse power crushing concrete waste are satisfactory and capable of being utilized in the construction industry. A better treatment of RCFA particles and enhancing its quality will make it possible to be utilized in producing structural concrete. Pulse power discharge technology is proposed in this research to produce RCFA, which is a more effective and promising technique compared to other recycling methods to generate medium to high-quality recycled concrete fine aggregate with a reduced amount of powder, mitigate the environmental burden, and save more space.

Keywords: construction and demolition waste, concrete waste recycle fine aggregate, pulse power discharge

Procedia PDF Downloads 138

Authors: Fabienne Baraud, Lydia Leleyter, Sandra Poree, Melanie Lemoine

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SEDIBRIC (valorization de SEDIments en BRIQues et tuiles) is a French project that aims to replace a part of natural clays with dredged sediments in the preparation of fired bricks in order to propose an alternative solution for the management of harbor dredged sediments. The feasibility of such re-use is explored from a technical, economic, and environmental point of view. The present study focuses on the potential environmental impact of various chemical elements (Al, Ca, Cd, Co, Cr, Cu, Fe, Ni, Mg, Mn, Pb, Ti, and Zn) that are initially present in the dredged sediments. The total content (after acid digestion) and the environmental availability (estimated by single extractions with various extractants) of these elements are determined in the raw sediments and in the obtained fired bricks. The possible influence of some steps of the manufacturing process (sediment pre-treatment, firing) is also explored. The first results show that the pre-treatment step, which uses tap water to desalinate the raw sediment, does not influence the environmental availability of the studied elements. However, the firing process, performed at 900°C, can affect the amount of some elements detected in the bricks, as well as their environmental availability. We note that for Cr, or Ni, the HCl or EDTA availability was increased in the brick (compared to the availability in the raw sediment). For Cd, Cu, Pb, and Zn, the HCl and EDTA availability was reduced in the bricks, meaning that these elements were stabilized within the bricks.

Keywords: bricks, chemical extraction, metals, sediment

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Authors: Rachita Lal

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Solar energy is a clean energy source. Because it is readily available in India and has many potential decentralized uses, urban local authorities may use it in various ways to manage the energy needs in the territory under their control. Apart from these and other services for which people pay a substantial number of money, urban local councils play a crucial role in administering essential services like water supply, street lighting, and health care. ULBs may contribute considerably to the transition to solar energy, both for their benefit and simultaneously for several additional direct and indirect advantages at multiple levels. The research primarily focuses on using clean energy management to reduce urban areas' reliance on traditional (electricity) energy. A technique for estimating the rooftop solar power potential using GIS (Geographical Information System) is described. Given that the combustion of fossil fuels produces 75% of India's power, meeting the country's energy needs through renewable energy sources is a step toward sustainable development and combating climate change. The study will further help in categorization, phasing, and understanding the demand and supply and thus calculating the cumulative benefits. The main objectives are to study the consumption of conventional energy in the study area and to identify the potential areas where solar photovoltaic intervention can be installed.

Keywords: solar energy, GIS, clean energy management, sustainable development

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Authors: Adebayo J. Julius, Oluremi N. Iluyomade

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Livelihood in Nigeria is a paradox of poverty amidst plenty. The Country is endowed with a good climate for agriculture, naturally growing fruit trees and vegetables, and undomesticated water resources. In spite of all its endowment, Nigeria continues to live in poverty year in year out. Rural communities adopted for this study are Ido, Omi-Adio, Onigambari, Okija and Lambata, 500 questionnaires were administered to solicit information from the respondents. This study focused on comparative analysis of the utilization of community informatics for sustainable livelihoods through agriculture. The idea projected in this study is that small strategic changes in the modus operandi of social informatics can have a significant impact on the sustainability of livelihoods. This paper carefully explored the theories of community informatics and its efficacies in dealing with sustainability issues. This study identified, described and evaluates the roles of community informatics in some sectors of the economy, different analytical tools to benchmark the influence of social informatics in agriculture against what is obtainable in agricultural sectors of the economy were used. It further employed comparative analysis to build a case model for sustainable livelihood in agriculture through community informatics.

Keywords: informatics, model, rural community, livelihood, Nigeria

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Authors: Fayyaz Rasool, Shakeela Parveen

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The studies on genetic diversity of Labeo rohita by using molecular markers were carried out to investigate the genetic structure by RAPAD marker and the levels of polymorphism and similarity amongst the different groups of five populations of wild and farmed types. The samples were collected from different five locations as representatives of wild and hatchery raised populations. RAPAD data for Jaccard’s coefficient by following the un-weighted Pair Group Method with Arithmetic Mean (UPGMA) for Hierarchical Clustering of the similar groups on the basis of similarity amongst the genotypes and the dendrogram generated divided the randomly selected individuals of the five populations into three classes/clusters. The variance decomposition for the optimal classification values remained as 52.11% for within class variation, while 47.89% for the between class differences. The Principal Component Analysis (PCA) for grouping of the different genotypes from the different environmental conditions was done by Spearman Varimax rotation method for bi-plot generation of the co-occurrence of the same genotypes with similar genetic properties and specificity of different primers indicated clearly that the increase in the number of factors or components was correlated with the decrease in eigenvalues. The Kaiser Criterion based upon the eigenvalues greater than one, first two main factors accounted for 58.177% of cumulative variability.

Keywords: variation, clustering, PCA, wild, hatchery, RAPAD, Labeo rohita

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Authors: Qi Lu, Jian Deng, Daishun Huang, Chao Guo

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The lead cooled fast reactor is considered as one of the most potential Generation IV nuclear systems due to the low working pressure, the appreciable neutron economy, and the considerable passive characteristics. Meanwhile, the lead bismuth eutectic (LBE) has the related advantages of lead with the weaker corrosiveness, which has been paid much attention by recent decades. Moreover, the sub-channel code is a necessary analysis tool for the reactor thermal-hydraulic design and safety analysis, which has been developed combined with the accumulation of LBE experimental data and the understanding of physical phenomena. In this study, a sub-channel code available for LBE was developed, and the corresponding geometric characterization method of typical sub-channels was described in detail, especially for for the fuel assembly with wire spacer. As for this sub-channel code, the transversal thermal conduction through gap was taken into account. In addition, the physical properties, the heat transfer model, the flow resistance model and the turbulent mixing model were analyzed. Finally, the thermal-hydraulic experiments of LBE conducted on THEADES (THErmal-hydraulics and Ads DESign) were selected as the evaluation data of this sub-channel code, including 19 rods with wire spacer, and the calculated results were in good agreement with the experimental results.

Keywords: lead bismuth eutectic, sub-channel code, wire spacer, transversal thermal conduction

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Authors: Jenaidullah Batur, Sebghatullah Mudaber

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Currently, there is a list of catalysts that can reduce CO₂ to valuable chemicals and fuels, among them metal oxides such as TiO₂, known as promising photocatalysts to produce hydrogen and CO unless they are at an earlier age and still need to promote activity to able for produce fabricated values. Herein, in this work, we provided a novel, facile and eco-friendly synthesis strategy to synthesize more effective TiO₂-organic composite materials to selectively reduce CO₂ to CO. In this experiment, commercial nanocrystalline TiO₂ and saccharin with Li (LiBr, LiCl) were synthesized using the facile physical grinding in the motel pestle for 10 minutes, then added 10 mL of deionized water (18.2 megaohms) on the 300mg composite catalyst before samples moving for hydrothermal heating for 24 hours at 80 C in the oven. Compared with nanosized TiO₂, the new TiO₂-Sac-Li indeed displays a high CO generation rate of 70.83 μmol/g/h, which is 7 times higher than TiO₂, which shows enhancement in CO₂ reduction and an apparent improvement in charge carrier dynamic. The CO₂ reduction process at the gas-solid interface on TiO₂-Sac-Li composite semiconductors is investigated by functional calculations and several characterization methods. The results indicate that CO₂ can be easily activated by the TiO₂-Sac-Li atoms on the surface. This work innovatively investigates CO₂ reduction in novel composite materials and helps to broaden the applications of composite materials semiconductors.

Keywords: green chemistry, green synthesis, TiO₂, photocatalyst

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Authors: Riham A. Ragheb

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Water is a fundamental attraction in all cultures and among all classes of people, tourists and citizens. It is a favorite location for major tourism initiatives, celebrations and ceremonies. The vitality of any city depends on citizen action to take part in creating the neighborhoods they desire. Waterfront can provide extensive new areas of high quality public open space in parts of the city that are popular venues for social activities and also have the highest land values. Each city must have a character that can be used as a key attraction for the development. The morphology of a waterfront can be identified by both its physical characteristics and the socio-cultural activities that take place in the area. Alexandria has been selected as an area of study because it has a unique character due to its possession of a variety of waterfronts. This paper aims to set some criteria of successful waterfront development and then through these criteria analyzing the development of the Qaitbay waterfront in the eastern harbor in Alexandria, Egypt. Hence, a comprehensive improvement of the waterfront areas is certainly needed to ensure a successful waterfront development radiated the sense of uniformity and coherence. Alexandria can benefit from these criteria to develop its urban waterfront in order to preserve and revitalize its unique waterfront character and achieve mixed uses and tourism development.

Keywords: place making, Qaitbay, responsive environment, sustainable urban design, waterfront development

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Authors: Khamael M. Abualnaja, Lidija Šiller, Ben R. Horrocks

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The structural characterization of silicon nano crystals (SiNCs) have been carried out using transmission electron microscope (TEM) and atomic force microscopy (AFM). SiNCs are crystalline with an average diameter of 65 nm. Erbium trichloride was added to silicon nano crystals using a simple chemical procedure. Erbium is useful in this context because it has a narrow emission band at ⋍1536 nm which corresponds to a standard optical telecommunication wavelength. The optical properties of SiNCs and erbium-mixed SiNCs samples have been characterized using UV-vis spectroscopy, confocal Raman spectroscopy and photoluminescence spectroscopy (PL). SiNCs and erbium-mixed SiNCs samples exhibit an orange PL emission peak at around 595 nm that arise from radiative recombination of Si. Erbium-mixed SiNCs also shows a weak PL emission peak at ⋍1536 nm that attributed to the intra-4f transition in erbium ions. The intensity of the PL peak of Si in erbium-mixed SiNCs is increased in the intensity up to ×3 as compared to pure SiNCs. It was observed that intensity of 1536 nm peak decreased dramatically in the presence of silicon nano crystals and the PL emission peak of silicon nano crystals is increased. Therefore, the resulted data present that the energy transfer from erbium ions to SiNCs due to the chemical mixing method which used in this work.

Keywords: Silicon Nanocrystals (SiNCs), Erbium Ion, photoluminescence, energy transfer

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Authors: Ivan Tolj

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Water produced during electrochemical reaction in Proton Exchange Membrane (PEM) fuel cell can be used for internal humidification of reactant gases; hydrogen and air. On such a way it is possible to eliminate expensive external humidifiers and simplify fuel cell balance-of-plant (BoP). When fuel cell operates at constant temperature (usually between 60 °C and 80 °C) relatively cold and dry ambient air heats up quickly upon entering channels which cause further drop in relative humidity (below 20%). Low relative humidity of reactant gases dries up polymer membrane and decrease its proton conductivity which results in fuel cell performance drop. It is possible to maintain such temperature profile throughout fuel cell cathode channel which will result in close to 100 % RH. In order to achieve this, passive heat exchanger was designed using commercial CFD software (ANSYS Fluent). Such passive heat exchanger (with variable surface area) is suitable for small scale PEM fuel cells. In this study, passive heat exchanger for single PEM fuel cell segment (with 20 x 1 cm active area) was developed. Results show close to 100 % RH of air throughout cathode channel with increased fuel cell performance (mainly improved polarization curve) and improved durability.

Keywords: PEM fuel cell, passive heat exchange, relative humidity, thermal management

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Authors: Mohamed A. G. H. Abdalsadig, Amir Nourian, G. G. Nasr, M. Babaie

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Gas lift is one of the most common forms of artificial lift, particularly for offshore wells because of its relative down hole simplicity, flexibility, reliability, and ability to operate over a large range of rates and occupy very little space at the well head. Presently, petroleum industry is investing in exploration and development fields in offshore locations where oil and gas wells are being drilled thousands of feet below the ocean in high pressure and temperature conditions. Therefore, gas-lifted oil wells are capable of failure through gas lift valves which are considered as the heart of the gas lift system for controlling the amount of the gas inside the tubing string. The gas injection rate through gas lift valve must be controlled to be sufficient to obtain and maintain critical flow, also, gas lift valves must be designed not only to allow gas passage through it and prevent oil passage, but also for gas injection into wells to be started and stopped when needed. In this paper, smart gas lift valve has been used to investigate the effect of the valve port size, depth of injection and vertical lift performance on well productivity; all these aspects have been investigated using PROSPER simulator program coupled with experimental data. The results show that by using smart gas lift valve, the gas injection rate can be controlled which leads to improved flow performance.

Keywords: Effect of gas lift valve port size, effect water cut, vertical flow performance

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Authors: Eva Tvrdá, Hana Greifová, Peter Ivanič, Norbert Lukáč

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The aim of this study was to evaluate the dose- and time-dependent in vitro effects of berberine (BER), a natural alkaloid with numerous biological properties on bovine spermatozoa during three time periods (0 h, 2 h, 24 h). Bovine semen samples were diluted and cultivated in physiological saline solution containing 0.5% DMSO together with 200, 100, 50, 10, 5, and 1 μmol/L BER. Spermatozoa motility was assessed using the computer assisted semen analyzer. The viability of spermatozoa was assessed by the metabolic (MTT) assay, production of superoxide radicals was quantified using the nitroblue tetrazolium (NBT) test, and chemiluminescence was used to evaluate the generation of reactive oxygen species (ROS). Cell lysates were prepared and the extent of lipid peroxidation (LPO) was evaluated using the TBARS assay. The results of the movement activity showed a significant increase in the motility during long term cultivation in case of concentrations ranging between 1 and 10 μmol/L BER (P < 0.01; P < 0.001; 24 h). At the same time, supplementation of 1, 5 and 10 μmol/L BER led to a significant preservation of the cell viability (P < 0.001; 24 h). BER addition at a range of 1-50 μmol/L also provided a significantly higher protection against superoxide (P < 0.05) and ROS (P < 0.001; P < 0.01) overgeneration as well as LPO (P < 0.01; P<0.05) after a 24 h cultivation. We may suggest that supplementation of BER to bovine spermatozoa, particularly at concentrations ranging between 1 and 50 μmol/L, may offer protection to the motility, viability and oxidative status of the spermatozoa, particularly notable at 24 h.

Keywords: berberine, bulls, motility, oxidative profile, spermatozoa, viability

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Authors: Xinyong Li

Abstract:

A new coupling system was constructed by combining photo-electrochemical cell with eletro-fenton cell (PEC-EF). The electrode material in this system was derived from MnyFe₁₋yCo Prussian-Blue-Analog (PBA). Mn₀.₄Fe₀.₆Co₀.₆₇-N@C spin-coated on carbon paper behaved as the gas diffusion cathode and Mn₀.₄Fe₀.₆Co₀.₆₇O₂.₂ spin-coated on fluorine-tin oxide glass (FTO) as anode. The two separated cells could degrade Sulfamethoxazole (SMX) simultaneously and some coupling mechanisms by PEC and EF enhancing the degradation efficiency were investigated. The continuous on-site generation of H₂O₂ at cathode through an oxygen reduction reaction (ORR) was realized over rotating ring-disk electrode (RRDE). The electron transfer number (n) of the ORR with Mn₀.₄Fe₀.₆Co₀.₆₇-N@C was 2.5 in the selected potential and pH range. The photo-electrochemical properties of Mn₀.₄Fe₀.₆Co₀.₆₇O₂.₂ were systematically studied, which displayed good response towards visible light. The photo-induced electrons at anode can transfer to cathode for further use. Efficient photo-electro-catalytic performance was observed in degrading SMX. Almost 100% SMX removal was achieved in 120 min. This work not only provided a highly effective technique for antibiotic treatment but also revealed the synergic effect between PEC and EF.

Keywords: Electro-Fenton, photo-electrochemical, synergic effect, sulfamethoxazole

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Authors: Isil Gazioglu, Abdulselam Ertas

Abstract:

Aflatoxins (AFs) are secondary toxic metabolites of Aspergillus flavus and A. parasiticus. AFs can be absorbed through the skin. Potent carcinogens like AFs should be completely absent from cosmetics, this can be achieved by careful quality control of the raw plant materials. Regulatory limits for aflatoxins have been established in many countries, and reliable testing methodology is needed to implement and enforce the regulatory limits. In this study, ten medicinal plant samples (Bundelia tournefortti, Capsella bursa-pastoris, Carduus tenuiflorus, Cardaria draba, Malva neglecta, Malvella sharardiana, Melissa officinalis, Sideritis libanotica, Stakys thirkei, Thymus nummularius) were investigated for aflatoxin (AF) contaminations by employing an HPLC assay for the determination of AFB1, B2, G1 and G2. The samples were extracted with 70% (v/v) methanol in water before further cleaned up with an immunoaffinity column and followed by the detection of AFs by using an electrochemically post-column derivatization with Kobra-Cell and fluorescence detector. The extraction procedure was optimized in order to obtain the best recovery. The method was successfully carried out with all medicinal plant samples. The results revealed that five (50%) of samples were contaminated with AFs. The association between particular samples and the AF contaminated could not be determined due to the low frequency of positive samples.

Keywords: aflatoxin B1, HPLC-FLD, KOBRA-Cell, mycotoxin

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Authors: Yadgar Tayfur, Antony Darby, Tim Ibell, Mark Evernden, John Orr

Abstract:

Fabric form-work is a technique to cast concrete structures with a great advantage of saving concrete material of up to 40%. This technique is particularly associated with the optimized concrete structures that usually have smaller cross-section dimensions than equivalent prismatic members. However, this can make the structural system produced from these members prone to smaller serviceability safety margins. Therefore, it is very important to understand the serviceability issue of non-prismatic concrete structures. In this paper, an analytical computer-based model to optimize concrete beams and to predict load-deflection behaviour of both prismatic and non-prismatic concrete beams is presented. The model was developed based on the method of sectional analysis and integration of curvatures. Results from the analytical model were compared to load-deflection behaviour of a number of beams with different geometric and material properties from other researchers. The results of the comparison show that the analytical program can accurately predict the load-deflection response of concrete beams with medium reinforcement ratios. However, it over-estimates deflection values for lightly reinforced specimens. Finally, the analytical program acceptably predicted load-deflection behaviour of on-prismatic concrete beams.

Keywords: fabric-formed concrete, continuous beams, optimisation, serviceability

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Authors: F. J. Puertas, M. Castro, A. Tebar, P. J. Fito, R. Gadea, J. M. Monzó, R. J. Colom

Abstract:

There is a great diversity of diseases that affect the integrity of the walls of the esophagus, generally of a digestive nature. Among them, gastroesophageal reflux is a common disease in the general population, affecting the patient's quality of life; however, there are still unmet diagnostic and therapeutic issues. The consequences of untreated or asymptomatic acid reflux on the esophageal mucosa are not only pain, heartburn, and acid regurgitation but also an increased risk of esophageal cancer. Currently, the diagnostic methods to detect problems in the esophageal tract are invasive and annoying, as 24-hour impedance-pH monitoring forces the patient to be uncomfortable for hours to be able to make a correct diagnosis. In this work, the development of a sensor able to measure in depth is proposed, allowing the detection of liquids circulating in the esophageal tract. The multisensor detection system is based on radiofrequency photospectrometry. At an experimental level, consumers representative of the population in terms of sex and age have been used, placing the sensors between the trachea and the diaphragm analyzing the measurements in vacuum, water, orange juice and saline medium. The results obtained have allowed us to detect the appearance of different liquid media in the esophagus, segregating them based on their ionic content.

Keywords: bioimpedance, dielectric spectroscopy, gastroesophageal reflux, GERD

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Authors: Jyotika Chopra, Dinesh Goyal

Abstract:

A study was initiated to examine the effects of corn gluten hydrolysate on seedlings growth and its development. Corn gluten is the byproduct of starch industry rich in proteins was hydrolysed by acid and alkali, and the impact of hydrolysate was studied on seed germination of Vigna radiata, Phaseolus vulagris (Fabaceae) and Triticum aestivum and Oryza sativa (Gramineae). For this, the optimum hydrolysis was obtained by 4NHCl and 4M NaOH where insoluble protein in gluten was broken down to glutamic acid, alanine, aspartic acid which was initially confirmed by biuret test, xanthoproteic, solubility and chromatographic tests. The seeds of above families were separately treated with different dilutions of corn gluten hydrolysate ranging from 1-100% to see effects produced by these dilutions on seed germination, plumule, and radical growth. The seedlings were put in the Petri plates and placed in the optimized conditions of temperature (37˚C) and photoperiod of 16:8 hours. The results indicate the plumule of all seeds shows the increase in growth pattern up to 25.75%. Whereas radical shows the increase in growth up to 25.88% till 10% of dilution of corn and wheat gluten hydrolysate with respect to water as blank. Further, there is decrease in growth from 30- 100% of dilutions of both, the hydrolysate indicates the inhibitory effects which unveil about the careful usage of gluten hydrolysate.

Keywords: corn gluten, characterization, hydrolysis, seedling growth

Procedia PDF Downloads 107