Search results for: chemical sensitivity
972 Arsenic and Fluoride Contamination in Lahore, Pakistan: Spatial Distribution, Mineralization Control and Sources
Authors: Zainab Abbas Soharwardi, Chunli Su, Harold Wilson Tumwitike Mapoma, Syed Zahid Aziz, Mahmut Ince
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This study investigated the spatial variations of groundwater chemistry used by communities in Lahore city with emphasis on arsenic (As) and fluoride (F) levels. A total of 472 tubewell samples were collected from 7 towns and analyzed for physical and chemical parameters, including pH, turbidity, electrical conductivity (EC), total dissolved solids (TDS), total hardness, HCO3, Ca2+, Mg2+, Na+, K+, SO42-, Cl-, NO3-, NO2-, F- and As. There were significant spatial variations observed for total hardness, TDS, HCO3, NO3 and As. In general, the south-east of the city displayed higher TH and HCO3 while the north-east showed significantly higher As concentrations attributed to the heterogeneity of the aquifer and industrial activities. In most cases, As was higher than WHO limit value. Indiscriminate disposal of domestic and commercial wastewater into River Ravi is the cause of elevated NO3 observed in the north-west compared to other places in the area. Investigation of the groundwater type revealed facies in the order: Ca-Mg-HCO3-SO4 > Mg-Ca-HCO3-SO4 > Ca-Mg-HCO3-SO4-Cl > Mg-Ca-HCO3-SO4 > Ca-HCO3-SO4 > Ca-Mg-SO4-HCO3. The plausible mineralization control mechanism seems to be that of carbonate weathering, although silicate weathering is probable. Moreover, PHREEQC model results showed that the groundwater was under saturated with respect to evaporites (anhydrite, fluorite, gypsum and halite) while generally equilibrium to saturated with respect to aragonite, calcite and dolomite. The Hierarchical Cluster Analysis (HCA) showed that pH significantly affected As, F, NO3 and NO2 while HCO3 contributing most to the observed TDS values in Lahore. It is concluded that inherent mineral dissolution/ precipitation, pH, oxic conditions, anthropogenic activities, atmospheric transport/ wet deposition, microbial activities and surface soil characteristics play their significant roles in elevating both As and F in the city's groundwater.Keywords: Lahore, arsenic, fluoride, groundwater
Procedia PDF Downloads 541971 Application of Functionalized Magnetic Particles as Demulsifier for Oil‐in‐Water Emulsions
Authors: Hamideh Hamedi, Nima Rezaei, Sohrab Zendehboudi
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Separating emulsified oil contaminations from waste- or produced water is of interest to various industries. Magnetic particles (MPs) application for separating dispersed and emulsified oil from wastewater is becoming more popular. Stabilization of MPs is required through developing a coating layer on their surfaces to prevent their agglomeration and enhance their dispersibility. In this research, we study the effects of coating material, size, and concentration of iron oxide MPs on oil separation efficiency, using oil adsorption capacity measurements. We functionalize both micro-and nanoparticles of Fe3O4 using sodium dodecyl sulfate (SDS) as an anionic surfactant, cetyltrimethylammonium bromide (CTAB) as a cationic surfactant, and stearic acid (SA). The chemical structures and morphologies of these particles are characterized using Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy Dispersive X-ray (EDX). The oil-water separation results indicate that a low dosage of the coated magnetic nanoparticle with CTAB (0.5 g/L MNP-CTAB) results the highest oil adsorption capacity (nearly 100%) for 1000 ppm dodecane-in-water emulsion, containing ultra-small droplets (250–300 nm). While separation efficiency of the same dosage of bare MNPs is around 57.5%. Demulsification results of magnetic microparticles (MMPs) also reveal that the functionalizing particles with CTAB increase oil removal efficiency from 86.3% for bare MMP to 92% for MMP-CTAB. Comparing the results of different coating materials implies that the major interaction reaction is an electrostatic attraction between negatively charged oil droplets and positively charged MNP-CTAB and MMP-CTAB. Furthermore, the synthesized nanoparticles could be recycled and reused; after ten cycles the oil adsorption capacity slightly decreases to near 95%. In conclusion, functionalized magnetic particles with high oil separation efficiency could be used effectively in treatment of oily wastewater. Finally, optimization of the adsorption process is required by considering the effective system variables, and fluid properties.Keywords: oily wastewater treatment, emulsions, oil-water separation, adsorption, magnetic nanoparticles
Procedia PDF Downloads 99970 Treatment of Low-Grade Iron Ore Using Two Stage Wet High-Intensity Magnetic Separation Technique
Authors: Moses C. Siame, Kazutoshi Haga, Atsushi Shibayama
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This study investigates the removal of silica, alumina and phosphorus as impurities from Sanje iron ore using wet high-intensity magnetic separation (WHIMS). Sanje iron ore contains low-grade hematite ore found in Nampundwe area of Zambia from which iron is to be used as the feed in the steelmaking process. The chemical composition analysis using X-ray Florence spectrometer showed that Sanje low-grade ore contains 48.90 mass% of hematite (Fe2O3) with 34.18 mass% as an iron grade. The ore also contains silica (SiO2) and alumina (Al2O3) of 31.10 mass% and 7.65 mass% respectively. The mineralogical analysis using X-ray diffraction spectrometer showed hematite and silica as the major mineral components of the ore while magnetite and alumina exist as minor mineral components. Mineral particle distribution analysis was done using scanning electron microscope with an X-ray energy dispersion spectrometry (SEM-EDS) and images showed that the average mineral size distribution of alumina-silicate gangue particles is in order of 100 μm and exists as iron-bearing interlocked particles. Magnetic separation was done using series L model 4 Magnetic Separator. The effect of various magnetic separation parameters such as magnetic flux density, particle size, and pulp density of the feed was studied during magnetic separation experiments. The ore with average particle size of 25 µm and pulp density of 2.5% was concentrated using pulp flow of 7 L/min. The results showed that 10 T was optimal magnetic flux density which enhanced the recovery of 93.08% of iron with 53.22 mass% grade. The gangue mineral particles containing 12 mass% silica and 3.94 mass% alumna remained in the concentrate, therefore the concentrate was further treated in the second stage WHIMS using the same parameters from the first stage. The second stage process recovered 83.41% of iron with 67.07 mass% grade. Silica was reduced to 2.14 mass% and alumina to 1.30 mass%. Accordingly, phosphorus was also reduced to 0.02 mass%. Therefore, the two stage magnetic separation process was established using these results.Keywords: Sanje iron ore, magnetic separation, silica, alumina, recovery
Procedia PDF Downloads 249969 Active Exopolysaccharides Based Edible Coating Enriched with Red Seaweed (Gracilaria gracilis) Extract for Improved Preservation of Shrimp Quality during Refrigerated Storage
Authors: Rafik Balti, Mohamed Ben Mansour, Abdellah Arhaliass, Anthony Masse
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Unfortunately, shrimps are highly perishable and they start deteriorating immediately after death owing to their high water content and nutritional components. Currently, there has been an increasing interest in bioactive edible films and coatings to preserve the freshness and quality of foods. In this study, active edible coatings from microalgal exopolysaccharides (EPS) enriched with different concentrations of Red Seaweed Extract (RSE) (0.5, 1 and 1.5 % (w/v)) were developed and their effects on the quality changes of white shrimp during refrigerated storage (4 ± 1 °C) were examined over a period of 8 days. The control and the coated shrimp samples were analyzed periodically for microbiological (total viable bacteria, psychrotrophic bacteria, and enterobacteriaceae counts), chemical (pH, TVB-N, TMA-N, PV, TBARS), textural and sensory characteristics. The results indicated that the coating with a mixture of EPS and RSE could significantly decrease the total volatile basic nitrogen (TVB-N), trimethylamine (TMA) and thiobarbituric acid reactive substances (TBARS) (p < 0.05). With storage, EPS coatings containing RSE at both levels (1 and 1.5 %) were more effective in inhibiting the microbial species studied, specially psychrotrophic bacteria. Also, EPS + RSE coated samples had lower polyphenol oxidase (PPO) activity and lipid oxidation (p < 0.05) toward the end of storage. Textural and color properties of coated shrimp were generally more acceptable. Sensory scores indicated no significant changes in all samples during storage. The obtained results indicate that the edible EPS coating solutions enriched with RSE have noticeable effects on the quality and shelf life of shrimps when compared to control group. Finally, the present work demonstrates the effectiveness of EPS enriched coatings, offering a promising alternative to preserve more better the quality characteristics and to extend the shelf life of shrimp during the refrigerated storageKeywords: active coating, exopolysaccharides, red seaweed, refrigerated storage, white shrimp
Procedia PDF Downloads 202968 Treatment of a Galvanization Wastewater in a Fixed-Bed Column Using L. hyperborean and P. canaliculata Macroalgae as Natural Cation Exchangers
Authors: Tatiana A. Pozdniakova, Maria A. P. Cechinel, Luciana P. Mazur, Rui A. R. Boaventura, Vitor J. P. Vilar.
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Two brown macroalgae, Laminaria hyperborea and Pelvetia canaliculata, were employed as natural cation exchangers in a fixed-bed column for Zn(II) removal from a galvanization wastewater. The column (4.8 cm internal diameter) was packed with 30-59 g of previously hydrated algae up to a bed height of 17-27 cm. The wastewater or eluent was percolated using a peristaltic pump at a flow rate of 10 mL/min. The effluent used in each experiment presented similar characteristics: pH of 6.7, 55 mg/L of chemical oxygen demand and about 300, 44, 186 and 244 mg/L of sodium, calcium, chloride and sulphate ions, respectively. The main difference was nitrate concentration: 20 mg/L for the effluent used with L. hyperborean and 341 mg/L for the effluent used with P. canaliculata. The inlet zinc concentration also differed slightly: 11.2 mg/L for L. hyperborean and 8.9 mg/L for P. canaliculata experiments. The breakthrough time was approximately 22.5 hours for both macroalgae, corresponding to a service capacity of 43 bed volumes. This indicates that 30 g of biomass is able to treat 13.5 L of the galvanization wastewater. The uptake capacities at the saturation point were similar to that obtained in batch studies (unpublished data) for both algae. After column exhaustion, desorption with 0.1 M HNO3 was performed. Desorption using 9 and 8 bed volumes of eluent achieved an efficiency of 100 and 91%, respectively for L. hyperborean and P. canaliculata. After elution with nitric acid, the column was regenerated using different strategies: i) convert all the binding sites in the sodium form, by passing a solution of 0.5 M NaCl, until achieve a final pH of 6.0; ii) passing only tap water in order to increase the solution pH inside the column until pH 3.0, and in this case the second sorption cycle was performed using protonated algae. In the first approach, in order to remove the excess of salt inside the column, distilled water was passed through the column, leading to the algae structure destruction and the column collapsed. Using the second approach, the algae remained intact during three consecutive sorption/desorption cycles without loss of performance.Keywords: biosorption, zinc, galvanization wastewater, packed-bed column
Procedia PDF Downloads 307967 Investigation of Input Energy Efficiency in Corn (KSC704) Farming in Khoy City, Iran
Authors: Nasser Hosseini
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Energy cycle is one of the essential points in agricultural ecosystems all over the world. Corn is one of the important products in Khoy city. Knowing input energy level and evaluating output energy from farms to reduce energy and increase efficiency in farms is very important if one can reduce input energy level into farms through the indices like poisons, fertilization, tractor energy and labour force. In addition to the net income of the farmers, this issue would play a significant role in preserving farm ecosystem from pollution and wrecker factors. For this reason, energy balance sheet in corn farms as well as input and output energy in 2012-2013 were researched by distributing a questionnaire among farmers in various villages in Khoy city. Then, the input energy amount into farms via energy-consuming factors, mentioned above, with regard to special coefficients was computed. Energy was computed on the basis of seed corn function, chemical compound and its content as well. In this investigation, we evaluated the level of stored energy 10792831 kcal per hectare. We found out that the greatest part of energy depended on irrigation which has 5136141.8 kcal and nitrate fertilizer energy with 2509760 kcal and the lowest part of energy depended on phosphor fertilizer, the rate of posited energy equaled 36362500 kcal and energy efficiency on the basis of seed corn function were estimated as 3.36. We found some ways to reduce consumptive energy in farm and nitrate fertilizer and, on the other hand, to increase balance sheet. They are, to name a few, using alternative farming and potherbs for biological stabilizing of nitrogen and changing kind of fertilizers such as urea fertilizer with sulphur cover, and using new generation of irrigation, the compound of water super absorbent like colored hydrogels and using natural fertilizer to preserve.Keywords: corn (KSC704), output and input, energy efficiency, Khoy city
Procedia PDF Downloads 428966 Two-Dimensional Material-Based Negative Differential Resistance Device with High Peak-to- Valley Current Ratio for Multi-Valued Logic Circuits
Authors: Kwan-Ho Kim, Jin-Hong Park
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The multi-valued logic (MVL) circuits, which can handle more than two logic states, are one of the promising solutions to overcome the bit density limitations of conventional binary logic systems. Recently, tunneling devices such as Esaki diode and resonant tunneling diode (RTD) have been extensively explored to construct the MVL circuits. These tunneling devices present a negative differential resistance (NDR) phenomenon in which a current decreases as a voltage increases in a specific applied voltage region. Due to this non-monotonic current behavior, the tunneling devices have more than two threshold voltages, consequently enabling construction of MVL circuits. Recently, the emergence of two dimensional (2D) van der Waals (vdW) crystals has opened up the possibility to fabricate such tunneling devices easily. Owing to the defect-free surface of the 2D crystals, a very abrupt junction interface could be formed through a simple stacking process, which subsequently allowed the implementation of a high-performance tunneling device. Here, we report a vdW heterostructure based tunneling device with multiple threshold voltages, which was fabricated with black phosphorus (BP) and hafnium diselenide (HfSe₂). First, we exfoliated BP on the SiO₂ substrate and then transferred HfSe₂ on BP using dry transfer method. The BP and HfSe₂ form type-Ⅲ heterojunction so that the highly doped n+/p+ interface can be easily implemented without additional electrical or chemical doping process. Owing to high natural doping at the junction, record high peak to valley ratio (PVCR) of 16 was observed to the best our knowledge in 2D materials based NDR device. Furthermore, based on this, we first demonstrate the feasibility of the ternary latch by connecting two multi-threshold voltage devices in series.Keywords: two dimensional van der Waals crystal, multi-valued logic, negative differential resistnace, tunneling device
Procedia PDF Downloads 205965 Fuzzy Data, Random Drift, and a Theoretical Model for the Sequential Emergence of Religious Capacity in Genus Homo
Authors: Margaret Boone Rappaport, Christopher J. Corbally
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The ancient ape ancestral population from which living great ape and human species evolved had demographic features affecting their evolution. The population was large, had great genetic variability, and natural selection was effective at honing adaptations. The emerging populations of chimpanzees and humans were affected more by founder effects and genetic drift because they were smaller. Natural selection did not disappear, but it was not as strong. Consequences of the 'population crash' and the human effective population size are introduced briefly. The history of the ancient apes is written in the genomes of living humans and great apes. The expansion of the brain began before the human line emerged. Coalescence times for some genes are very old – up to several million years, long before Homo sapiens. The mismatch between gene trees and species trees highlights the anthropoid speciation processes, and gives the human genome history a fuzzy, probabilistic quality. However, it suggests traits that might form a foundation for capacities emerging later. A theoretical model is presented in which the genomes of early ape populations provide the substructure for the emergence of religious capacity later on the human line. The model does not search for religion, but its foundations. It suggests a course by which an evolutionary line that began with prosimians eventually produced a human species with biologically based religious capacity. The model of the sequential emergence of religious capacity relies on cognitive science, neuroscience, paleoneurology, primate field studies, cognitive archaeology, genomics, and population genetics. And, it emphasizes five trait types: (1) Documented, positive selection of sensory capabilities on the human line may have favored survival, but also eventually enriched human religious experience. (2) The bonobo model suggests a possible down-regulation of aggression and increase in tolerance while feeding, as well as paedomorphism – but, in a human species that remains cognitively sharp (unlike the bonobo). The two species emerged from the same ancient ape population, so it is logical to search for shared traits. (3) An up-regulation of emotional sensitivity and compassion seems to have occurred on the human line. This finds support in modern genetic studies. (4) The authors’ published model of morality's emergence in Homo erectus encompasses a cognitively based, decision-making capacity that was hypothetically overtaken, in part, by religious capacity. Together, they produced a strong, variable, biocultural capability to support human sociability. (5) The full flowering of human religious capacity came with the parietal expansion and smaller face (klinorhynchy) found only in Homo sapiens. Details from paleoneurology suggest the stage was set for human theologies. Larger parietal lobes allowed humans to imagine inner spaces, processes, and beings, and, with the frontal lobe, led to the first theologies composed of structured and integrated theories of the relationships between humans and the supernatural. The model leads to the evolution of a small population of African hominins that was ready to emerge with religious capacity when the species Homo sapiens evolved two hundred thousand years ago. By 50-60,000 years ago, when human ancestors left Africa, they were fully enabled.Keywords: genetic drift, genomics, parietal expansion, religious capacity
Procedia PDF Downloads 331964 Prospectivity Mapping of Orogenic Lode Gold Deposits Using Fuzzy Models: A Case Study of Saqqez Area, Northwestern Iran
Authors: Fanous Mohammadi, Majid H. Tangestani, Mohammad H. Tayebi
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This research aims to evaluate and compare Geographical Information Systems (GIS)-based fuzzy models for producing orogenic gold prospectivity maps in the Saqqez area, NW of Iran. Gold occurrences are hosted in sericite schist and mafic to felsic meta-volcanic rocks in this area and are associated with hydrothermal alterations that extend over ductile to brittle shear zones. The predictor maps, which represent the Pre-(Source/Trigger/Pathway), syn-(deposition/physical/chemical traps) and post-mineralization (preservation/distribution of indicator minerals) subsystems for gold mineralization, were generated using empirical understandings of the specifications of known orogenic gold deposits and gold mineral systems and were then pre-processed and integrated to produce mineral prospectivity maps. Five fuzzy logic operators, including AND, OR, Fuzzy Algebraic Product (FAP), Fuzzy Algebraic Sum (FAS), and GAMMA, were applied to the predictor maps in order to find the most efficient prediction model. Prediction-Area (P-A) plots and field observations were used to assess and evaluate the accuracy of prediction models. Mineral prospectivity maps generated by AND, OR, FAP, and FAS operators were inaccurate and, therefore, unable to pinpoint the exact location of discovered gold occurrences. The GAMMA operator, on the other hand, produced acceptable results and identified potentially economic target sites. The P-A plot revealed that 68 percent of known orogenic gold deposits are found in high and very high potential regions. The GAMMA operator was shown to be useful in predicting and defining cost-effective target sites for orogenic gold deposits, as well as optimizing mineral deposit exploitation.Keywords: mineral prospectivity mapping, fuzzy logic, GIS, orogenic gold deposit, Saqqez, Iran
Procedia PDF Downloads 112963 Synthesis of 5-Substituted 1H-Tetrazoles in Deep Eutectic Solvent
Authors: Swapnil A. Padvi, Dipak S. Dalal
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The chemistry of tetrazoles has been grown tremendously in the past few years because tetrazoles are important and useful class of heterocyclic compounds which have a widespread application such as anticancer, antimicrobial, analgesics, antibacterial, antifungal, antihypertensive, and anti-allergic drugs in medicinal chemistry. Furthermore, tetrazoles have application in material sciences as explosives, rocket propellants, and in information recording systems. In addition to this, they have a wide range of application in coordination chemistry as a ligand. Deep eutectic solvents (DES) have emerged over the current decade as a novel class of green reaction media and applied in various fields of sciences because of their unique physical and chemical properties similar to the ionic liquids such as low vapor pressure, non-volatility, high thermal stability and recyclability. In addition, the reactants of DES are cheaply available, low-toxic, and biodegradable, which makes them predominantly required for large-scale applications effectively in industrial production. Herein we report the [2+3] cycloaddition reaction of organic nitriles with sodium azide affords the corresponding 5-substituted 1H-tetrazoles in six different types of choline chloride based deep eutectic solvents under mild reaction condition. Choline chloride: ZnCl2 (1:2) showed the best results for the synthesis of 5-substituted 1 H-tetrazoles. This method reduces the disadvantages such as: the use of toxic metals and expensive reagents, drastic reaction conditions and the presence of dangerous hydrazoic acid. The approach provides environment-friendly, short reaction times, good to excellent yields; safe process and simple workup make this method an attractive and useful contribution to present green organic synthesis of 5-substituted-1H-tetrazoles. All synthesized compounds were characterized by IR, 1H NMR, 13C NMR and Mass spectroscopy. DES can be recovered and reused three times with very little loss in activity.Keywords: click chemistry, choline chloride, green chemistry, deep eutectic solvent, tetrazoles
Procedia PDF Downloads 223962 Production and Application of Organic Waste Compost for Urban Agriculture in Emerging Cities
Authors: Alemayehu Agizew Woldeamanuel, Mekonnen Maschal Tarekegn, Raj Mohan Balakrishina
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Composting is one of the conventional techniques adopted for organic waste management, but the practice is very limited in emerging cities despite the most of the waste generated is organic. This paper aims to examine the viability of composting for organic waste management in the emerging city of Addis Ababa, Ethiopia, by addressing the composting practice, quality of compost, and application of compost in urban agriculture. The study collects data using compost laboratory testing and urban farm households’ survey and uses descriptive analysis on the state of compost production and application, physicochemical analysis of the compost samples, and regression analysis on the urban farmer’s willingness to pay for compost. The findings of the study indicated that there is composting practice at a small scale, most of the producers use unsorted feedstock materials, aerobic composting is dominantly used, and the maturation period ranged from four to ten weeks. The carbon content of the compost ranges from 30.8 to 277.1 due to the type of feedstock applied, and this surpasses the ideal proportions for C:N ratio. The total nitrogen, pH, organic matter, and moisture content are relatively optimal. The levels of heavy metals measured for Mn, Cu, Pb, Cd and Cr⁶⁺ in the compost samples are also insignificant. In the urban agriculture sector, chemical fertilizer is the dominant type of soil input in crop productions but vegetable producers use a combination of both fertilizer and other organic inputs, including compost. The willingness to pay for compost depends on income, household size, gender, type of soil inputs, monitoring soil fertility, the main product of the farm, farming method and farm ownership. Finally, this study recommends the need for collaboration among stakeholders’ along the value chain of waste, awareness creation on the benefits of composting and addressing challenges faced by both compost producers and users.Keywords: composting, emerging city, organic waste management, urban agriculture
Procedia PDF Downloads 299961 Application of Multivariate Statistics and Hydro-Chemical Approach for Groundwater Quality Assessment: A Study on Birbhum District, West Bengal, India
Authors: N. C. Ghosh, Niladri Das, Prolay Mondal, Ranajit Ghosh
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Groundwater quality deterioration due to human activities has become a prime factor of modern life. The major concern of the study is to access spatial variation of groundwater quality and to identify the sources of groundwater chemicals and its impact on human health of the concerned area. Multivariate statistical techniques, cluster, principal component analysis, and hydrochemical fancies are been applied to measure groundwater quality data on 14 parameters from 107 sites distributed randomly throughout the Birbhum district. Five factors have been extracted using Varimax rotation with Kaiser Normalization. The first factor explains 27.61% of the total variance where high positive loading have been concentrated in TH, Ca, Mg, Cl and F (Fluoride). In the studied region, due to the presence of basaltic Rajmahal trap fluoride contamination is highly concentrated and that has an adverse impact on human health such as fluorosis. The second factor explains 24.41% of the total variance which includes Na, HCO₃, EC, and SO₄. The last factor or the fifth factor explains 8.85% of the total variance, and it includes pH which maintains the acidic and alkaline character of the groundwater. Hierarchical cluster analysis (HCA) grouped the 107 sampling station into two clusters. One cluster having high pollution and another cluster having less pollution. Moreover hydromorphological facies viz. Wilcox diagram, Doneen’s chart, and USSL diagram reveal the quality of the groundwater like the suitability of the groundwater for irrigation or water used for drinking purpose like permeability index of the groundwater, quality assessment of groundwater for irrigation. Gibb’s diagram depicts that the major portion of the groundwater of this region is rock dominated origin, as the western part of the region characterized by the Jharkhand plateau fringe comprises basalt, gneiss, granite rocks.Keywords: correlation, factor analysis, hydrological facies, hydrochemistry
Procedia PDF Downloads 207960 Behavioral Effects of Oxidant and Reduced Chemorepellent on Mutant and Wild-Type Tetrahymena thermophila
Authors: Ananya Govindarajan
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Tetrahymena thermophila is a single-cell, eukaryotic organism that belongs to the Protozoa Kingdom. Tetrahymena thermophila is often used in signal transduction pathway studies because of its ability to model sensory input and the effects of environmental conditions such as chemicals and temperature. The recently discovered G37 chemorepellent receptor showed increased responsiveness to all chemorepellents. Investigating the mutant G37 Tetrahymena gene in various test solutions, including ferric chloride, ferrous sulfate, hydrogen peroxide, tetrazolium blue, potassium chloride, and dithiothreitol were performed to determine the role of oxidants and reducing agents with the mutant and wild-type cells (CU427) to assess the role of the receptor. Behavioral assays and recordings processed by ImageJ indicated that ferric chloride, hydrogen peroxide, and tetrazolium blue yielded little to no chemorepellent responses from G37 cells (<20% ARs). CU427 cells were over-responsive based on the mean percent of cells (>50% ARs). Reducing agents elicited chemorepellent responses from both G37 and CU427, in addition to potassium chloride. Cell responses were classified as over-responsive (>50% ARs). Dithiothreitol yielded unexpected results as G37 (37.0% ARs) and CU427 (38.1% ARs) had relatively similar responses and were only responsive and not over-responsive to the reducing agent test chemical solution. Ultimately, this indicates that the G37 receptor is more interactive with molecules that are reducing agents or non-oxidant compounds; G37 may be unable to sense and respond to oxidants effectively, further elucidating the pathways of the G37 strain and nature of this receptor. Results also indicate that the CSF most likely contained an oxidant, like ferric chloride. This research can be further applied to neuronal influences and how specific compounds may affect human neurons individually and their excitability as the responses model action potentials and membrane potential.Keywords: tetrahymena thermophila, signal transduction, chemosensory, oxidant, reducing agent
Procedia PDF Downloads 122959 Influence of Degassing on the Curing Behaviour and Void Occurrence Properties of Epoxy / Anhydride Resin System
Authors: Latha Krishnan, Andrew Cobley
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Epoxy resin is most widely used as matrices for composites of aerospace, automotive and electronic applications due to its outstanding mechanical properties. These properties are chiefly predetermined by the chemical structure of the prepolymer and type of hardener but can also be varied by the processing conditions such as prepolymer and hardener mixing, degassing and curing conditions. In this research, the effect of degassing on the curing behaviour and the void occurrence is experimentally evaluated for epoxy /anhydride resin system. The epoxy prepolymer was mixed with an anhydride hardener and accelerator in an appropriate quantity. In order to investigate the effect of degassing on the curing behaviour and void content of the resin, the uncured resin samples were prepared using three different methods: 1) no degassing 2) degassing on prepolymer and 3) degassing on mixed solution of prepolymer and hardener with an accelerator. The uncured resins were tested in differential scanning calorimeter (DSC) to observe the changes in curing behaviour of the above three resin samples by analysing factors such as gel temperature, peak cure temperature and heat of reaction/heat flow in curing. Additionally, the completely cured samples were tested in DSC to identify the changes in the glass transition temperature (Tg) between the three samples. In order to evaluate the effect of degassing on the void content and morphology changes in the cured epoxy resin, the fractured surfaces of cured epoxy resin were examined under the scanning electron microscope (SEM). In addition, the amount of void, void geometry and void fraction were also investigated using an optical microscope and image J software (image analysis software). It was found that degassing at different stages of resin mixing had significant effects on properties such as glass transition temperature, the void content and void size of the epoxy/anhydride resin system. For example, degassing (vacuum applied on the mixed resin) has shown higher glass transition temperature (Tg) with lower void content.Keywords: anhydride epoxy, curing behaviour, degassing, void occurrence
Procedia PDF Downloads 207958 Physical Characterization of SnO₂ Films Prepared by the Rheotaxial Growth and Thermal Oxidation (RGTO) Method
Authors: A. Kabir, D. Boulainine, I. Bouanane, N. Benslim, B. Boudjema, C. Sedrati
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SnO₂ is an n-type semiconductor with a direct gap of about 3.6 eV. It is largely used in several domains such as nanocrystalline photovoltaic cells. Due to its interesting physic-chemical properties, this material was elaborated in thin film forms using different deposition techniques. It was found that SnO₂ properties were directly affected by the deposition method parameters. In this work, the RGTO method (Rheotaxial Growth and Thermal Oxidation) was used to deposit elaborate SnO₂ thin films. This technique consists on thermal oxidation of the Sn films deposited onto a substrate heated to a temperature close to Sn melting point (232°C). Such process allows the preparation of high porosity tin oxide films which are very suitable for the gas sensing. The films structural, morphological and optical properties pre and post thermal oxidation were studied using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Visible spectroscopy and Fourier transform infrared spectroscopy (FTIR) respectively. XRD patterns showed a polycrystalline structure of the cassiterite phase of SnO₂. The grain growth was found affected by the oxidation temperature. This grain size evolution was confronted to existing grain growth models in order to understand the growth mechanism. From SEM images, the as deposited Sn film was formed of difference diameter spherical agglomerations. As a function of the oxidation temperature, these spherical agglomerations shape changed due to the introduction of oxygen ions. The deformed spheres started to interconnect by forming bridges between them. The volume porosity, determined from the UV-Visible reflexion spectra, Changes as a function of the oxidation temperature. The variation of the crystalline fraction, determined from FTIR spectra, correlated with the variation of both the grain size and the volume porosity.Keywords: tin oxide, RGTO, grain growth, volume porosity, crystalline fraction
Procedia PDF Downloads 253957 Adhesion Enhancement of Boron Carbide Coatings on Aluminum Substrates Utilizing an Intermediate Adhesive Layer
Authors: Sharon Waichman, Shahaf Froim, Ido Zukerman, Shmuel Barzilai, Shmual Hayun, Avi Raveh
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Boron carbide is a ceramic material with superior properties such as high chemical and thermal stability, high hardness and high wear resistance. Moreover, it has a big cross section for neutron absorption and therefore can be employed in nuclear based applications. However, an efficient attachment of boron carbide to a metal such as aluminum can be very challenging, mainly because of the formation of aluminum-carbon bonds that are unstable in humid environment, the affinity of oxygen to the metal and the different thermal expansion coefficients of the two materials that may cause internal stresses and a subsequent failure of the bond. Here, we aimed to achieving a strong and a durable attachment between the boron carbide coating and the aluminum substrate. For this purpose, we applied Ti as a thin intermediate layer that provides a gradual change in the thermal expansion coefficients of the configured layers. This layer is continuous and therefore prevents the formation of aluminum-carbon bonds. Boron carbide coatings with a thickness of 1-5 µm were deposited on the aluminum substrate by pulse-DC magnetron sputtering. Prior to the deposition of the boron carbide layer, the surface was pretreated by energetic ion plasma followed by deposition of the Ti intermediate adhesive layer in a continuous process. The properties of the Ti intermediate layer were adjusted by the bias applied to the substrate. The boron carbide/aluminum bond was evaluated by various methods and complementary techniques, such as SEM/EDS, XRD, XPS, FTIR spectroscopy and Glow Discharge Spectroscopy (GDS), in order to explore the structure, composition and the properties of the layers and to study the adherence mechanism of the boron carbide/aluminum contact. Based on the interfacial bond characteristics, we propose a desirable solution for improved adhesion of boron carbide to aluminum using a highly efficient intermediate adhesive layer.Keywords: adhesion, boron carbide coatings, ceramic/metal bond, intermediate layer, pulsed-DC magnetron sputtering
Procedia PDF Downloads 155956 Manganese Imidazole Complexes: Electrocatalytic Hydrogen Production
Authors: Vishakha Kaim, Mookan Natarajan, Sandeep Kaur-Ghumaan
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Hydrogen is one of the most abundant elements present on earth’s crust and considered to be the simplest element in existence. It is not found naturally as a gas on earth and thus has to be manufactured. Hydrogen can be produced from a variety of sources, i.e., water, fossil fuels, or biomass and it is a byproduct of many chemical processes. It is also considered as a secondary source of energy commonly referred to as an energy carrier. Though hydrogen is not widely used as a fuel, it still has the potential for greater use in the future as a clean and renewable source of energy. Electrocatalysis is one of the important source for the production of hydrogen which could contribute to this prominent challenge. Metals such as platinum and palladium are considered efficient for hydrogen production but with limited applications. As a result, a wide variety of metal complexes with earth abundant elements and varied ligand environments have been explored for the electrochemical production of hydrogen. In nature, [FeFe] hydrogenase enzyme present in DesulfoVibrio desulfuricans and Clostridium pasteurianum catalyses the reversible interconversion of protons and electrons into dihydrogen. Since the first structure for the enzyme was reported in 1990s, a range of iron complexes has been synthesized as structural and functional mimics of the enzyme active site. Mn is one of the most desirable element for sustainable catalytic transformations, immediately behind Fe and Ti. Only limited number manganese complexes have been reported in the last two decades as catalysts for proton reduction. Furthermore, redox reactions could be carried out in a facile manner, due to the capability of manganese complexes to be stable at different oxidation states. Herein are reported, four µ2-thiolate bridged manganese complexes [Mn₂(CO)₆(μ-S₂N₄C₁₄H₁₀)] 1, [Mn₂(CO)7(μ- S₂N₄C₁₄H₁₀)] 2, Mn₂(CO)₆(μ-S₄N₂C₁₄H₁₀)] 3 and [Mn₂(CO)(μ- S₄N₂C₁₄H₁₀)] 4 have been synthesized and characterized. The cyclic voltammograms of the complexes displayed irreversible reduction peaks in the range - 0.9 to -1.3 V (vs. Fc⁺/Fc in acetonitrile at 0.1 Vs⁻¹). The complexes were catalytically active towards proton reduction in the presence of trifluoroacetic acid as seen from electrochemical investigations.Keywords: earth abundant, electrocatalytic, hydrogen, manganese
Procedia PDF Downloads 166955 Isolation and Identification of Fungi from Different Types of Medicinal Plants Cultivated in Ecuador
Authors: Ana Paola Echavarria, Mariuxi Medina, Haydelba D'Armas, Carmita Jaramillo, Diana San Martin
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The use of medicinal plants is one of the oldest and most extended medical therapies that goes back to prehistoric times, and nowadays, they are also used in the preparation of phytopharmaceuticals with options to cure diseases. The test for the determination of fungi was carried out in the Pharmacy Pilot Plant (treatment of the leaves of the plant species) and the Microbiology Laboratory (determination of fungi of the plant species, using growth medium called Sabouraud agar plus the vegetal sample), of the Academic Unit of Chemical Sciences and Health, of the Universidad Tecnica de Machala. Subsequently, colony counting was performed, both macroscopic, which is determined in the growth medium of the seeding, and microscopic, to identify the germinative forms using blue lactophenol. The procedure was repeated in duplicate to replicate the results data. The determination of the total fungal content of the following plant species was evaluated: Cymbopogon citratus (lemon verbena), Melissa officinalis (lemon balm), Taraxacum officinale (dandelion), Artemisia absinthium (absinthe), Piper carpunya (guaviduca), Moringa oleifera (moringa), Coriandrum sativum (coriander), Momordica charantia (achochilla), Borago officinalis (borage), Aloysia citriodora (cedron), Ambrosia artemisifolia (altamisa) and Ageratum conyzoides (mastrante). The results obtained showed that all the samples of the twelve plant species studied developed filamentous fungi, with great variability of them, within the permissible limits and contemplated by the Ecuadorian Institute of Normalization (INEN), being suitable as raw material for its use in the preparation of nutraceuticals and medicinal products or phytodrugs; with the exception of A. conyzoides (mastranto) which is the only species that exceeds the regulation in the average of dilutions.Keywords: colonies, fungi, medicinal plants, microbiological quality, Sabouraud agar
Procedia PDF Downloads 141954 Assessment of the Groundwater Agricultural Pollution Risk: Case of the Semi-Arid Region (Batna-East Algeria)
Authors: Dib Imane, Chettah Wahid, Khedidja Abdelhamid
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The plain of Gadaïne - Ain Yaghout, located in the wilaya of Batna (Eastern Algeria), experiences intensive human activities, particularly in agricultural practices which are accompanied by an increasing use of chemical fertilizers and manure. These activities lead to a degradation of the quality of water resources. In order to protect the quality of groundwater in this plain and formulate effective strategies to mitigate or avoid any contamination of groundwater, a risk assessment using the European method known as “COSTE Action 620” was applied to the mio-. plio-quaternary aquifer of this plain. Risk assessment requires the identification of existing dangers and their potential impact on groundwater by using a system of evaluation and weighting. In addition, it also requires the integration of the hydrogeological factors that influence the movement of contaminants by means of the intrinsic vulnerability maps of groundwater, which were produced according to the modified DRASTIC method. The overall danger on the plain ranges from very low to high. Farms containing stables, houses detached from the public sewer system, and sometimes manure piles were assigned a weighting factor expressing the highest degree of harmfulness; this created a medium to high danger index. Large areas for agricultural practice and grazing are characterized, successively, by low to very low danger. Therefore, the risks present at the study site are classified according to a range from medium to very high-risk intensity. These classes successively represent 3%, 49%, and 0.2% of the surface of the plain. Cultivated land and farms present a high to very high level of risk successively. In addition, with the exception of the salt mine, which presents a very high level of risk, the gas stations and cemeteries, as well as the railway line, represent a high level of risk.Keywords: semi-arid, quality of water resources, risk assessment, vulnerability, contaminants
Procedia PDF Downloads 38953 Clinico-pathological Study of Xeroderma Pigmentosa: A Case Series of Eight Cases
Authors: Kakali Roy, Sahana P. Raju, Subhra Dhar, Sandipan Dhar
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Introduction: Xeroderma pigmentosa (XP) is a rare inherited (autosomal recessive) disease resulting from impairment in DNA repair that involves recognition and repair of ultraviolet radiation (UVR) induced DNA damage in the nucleotide excision repair pathway. Which results in increased photosensitivity, UVR induced damage to skin and eye, increased susceptibility of skin and ocular cancer, and progressive neurodegeneration in some patients. XP is present worldwide, with higher incidence in areas having frequent consanguinity. Being extremely rare, there is limited literature on XP and associated complications. Here, the clinico-pathological experience (spectrum of clinical presentation, histopathological findings of malignant skin lesions, and progression) of managing 8 cases of XP is presented. Methodology: A retrospective study was conducted in a pediatric tertiary care hospital in eastern India during a ten-year period from 2013 to 2022. A clinical diagnosis was made based on severe sun burn or premature photo-aging and/or onset of cutaneous malignancies at early age (1st decade) in background of consanguinity and autosomal recessive inheritance pattern in family. Results: The mean age of presentation was 1.2 years (range of 7month-3years), while three children presented during their infancy. Male to female ratio was 5:3, and all were born of consanguineous marriage. They presented with dermatological manifestations (100%) followed by ophthalmic (75%) and/or neurological symptoms (25%). Patients had normal skin at birth but soon developed extreme sensitivity to UVR in the form of exaggerated sun tanning, burning, and blistering on minimal sun exposure, followed by abnormal skin pigmentation like freckles and lentiginosis. Subsequently, over time there was progressive xerosis, atrophy, wrinkling, and poikiloderma. Six patients had varied degree of ocular involvement, while three of them had severe manifestation, including madarosis, tylosis, ectropion, Lagopthalmos, Pthysis bulbi, clouding and scarring of the cornea with complete or partial loss of vision, and ophthalmic malignancies. 50% (n=4) cases had skin and ocular pre-malignant (actinic keratosis) and malignant lesions, including melanoma and non melanoma skin cancer (NMSC) like squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) in their early childhood. One patient had simultaneous occurrence of multiple malignancies together (SCC, BCC, and melanoma). Subnormal intelligence was noticed as neurological feature, and none had sensory neural hearing loss, microcephaly, neuroregression, or neurdeficit. All the patients had been being managed by a multidisciplinary team of pediatricians, dermatologists, ophthalmologists, neurologists and psychiatrists. Conclusion: Although till date there is no complete cure for XP and the disease is ultimately fatal. But increased awareness, early diagnosis followed by persistent vigorous protection from UVR, and regular screening for early detection of malignancies along with psychological support can drastically improve patients’ quality of life and life expectancy. Further research is required on formulating optimal management of XP, specifically the role and possibilities of gene therapy in XP.Keywords: childhood malignancies, dermato-pathological findings, eastern India, Xeroderma pigmentosa
Procedia PDF Downloads 70952 Microstructure, Mechanical and Tribological Properties of (TiTaZrNb)Nx Medium Entropy Nitride Coatings: Influence of Nitrogen Content and Bias Voltage
Authors: Mario Alejandro Grisales, M. Daniela Chimá, Gilberto Bejarano Gaitán
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High entropy alloys (HEA) and nitride (HEN) are currently very attractive to the automotive, aerospace, metalworking and materials forming manufacturing industry, among others, for exhibiting higher mechanical properties, wear resistance, and thermal stability than binary and ternary alloys. In this work medium-entropy coatings of TiTaZrNb and the nitrides of (TiTaZrNb)Nx were synthesized on to AISI 420 and M2 steel samples by the direct current magnetron sputtering technique. The influence of the bias voltage supplied to the substrate on the microstructure, chemical- and phase composition of the matrix coating was evaluated, and the effect of nitrogen flow on the microstructural, mechanical and tribological properties of the corresponding nitrides was studied. A change in the crystalline structure from BCC for TiTaZrNb coatings to FCC for (TiTaZrNb)Nx was observed, that is associated with the incorporation of nitrogen into the matrix and the consequent formation of a solid solution of (TiTaZrNb)Nx. An increase in hardness and residual stresses was observed with increasing bias voltage for TiTaZrNb, reaching 12.8 GPa for the coating deposited with a bias of -130V. In the case of (TiTaZrNb)Nx nitride, a greater hardness of 23 GPa is achieved for the coating deposited with a N2 flow of 12 sccm, which slightly drops to 21.7 GPa for that deposited with N2 flow of 15 sccm. The slight reduction in hardness could be associated with the precipitation of the TiN and ZrN phases that are formed at higher nitrogen flows. The specific wear rate of the deposited coatings ranged between 0.5xexp13 and 0.6xexp13 N/m2. The steel substrate exhibited an average hardness of 2.0 GPa and a specific wear rate of 203.2exp13 N/m2. Both the hardness and the specific wear rate of the synthesized nitride coatings were higher than that of the steel substrate, showing a protective effect of the steel against wear.Keywords: medium entropy coatings, hard coatings, magnetron sputtering, tribology, wear resistance
Procedia PDF Downloads 63951 KTiPO4F: The Negative Electrode Material for Potassium Batteries
Authors: Vahid Ramezankhani, Keith J. Stevenson, Stanislav. S. Fedotov
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Lithium-ion batteries (LIBs) play a pivotal role in achieving the key objective “zero-carbon emission” as countries agreed to reach a 1.5ᵒC global warming target according to the Paris agreement. Nowadays, due to the tremendous mobile and stationary consumption of small/large-format LIBs, the demand and consequently the price for such energy storage devices have been raised. The aforementioned challenges originate from the shrinkage of the major applied critical materials in these batteries, such as cobalt (Co), nickel (Ni), Lithium (Li), graphite (G), and manganese (Mn). Therefore, it is imperative to consider alternative elements to address issues corresponding to the limitation of resources around the globe. Potassium (K) is considered an effective alternative to Li since K is a more abundant element, has a higher operating potential, a faster diffusion rate, and the lowest stokes radius in comparison to the closest neighbors in the periodic table (Li and Na). Among all reported materials for metal-ion batteries, some of them possess the general formula AMXO4L [A = Li, Na, K; M = Fe, Ti, V; X = P, S, Si; L= O, F, OH] is of potential to be applied both as anode and cathode and enable researchers to investigate them in the full symmetric battery format. KTiPO4F (KTP structural material) has been previously reported by our group as a promising cathode with decent electronic properties. Herein, we report a synthesis, crystal structure characterization, morphology, as well as K-ion storage properties of KTiPO4F. Our investigation reveals that KTiPO4F delivers discharge capacity > 150 mAh/g at 26.6 mA/g (C/5 current rate) in the potential window of 0.001-3 V. Surprisingly, the cycling performance of C-KTiPO4F//K cell is stable for 1000 cycles at 130 mA/g (C current rate), presenting capacity > 130 mAh/g. More interestingly, we achieved to assemble full symmetric batteries where carbon-coated KTiPO4F serves as both negative and positive electrodes, delivering >70 mAh/g in the potential range of 0.001-4.2V.Keywords: anode material, potassium battery, chemical characterization, electrochemical properties
Procedia PDF Downloads 200950 Preparation and Characterization of Dendrimer-Encapsulated Ytterbium Nanoparticles to Produce a New Nano-Radio Pharmaceutical
Authors: Aghaei Amirkhizi Navideh, Sadjadi Soodeh Sadat, Moghaddam Banaem Leila, Athari Allaf Mitra, Johari Daha Fariba
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Dendrimers are good candidates for preparing metal nanoparticles because they can structurally and chemically well-defined templates and robust stabilizers. Poly amidoamine (PAMAM) dendrimer-based multifunctional cancer therapeutic conjugates have been designed and synthesized in pharmaceutical industry. In addition, encapsulated nanoparticle surfaces are accessible to substrates so that catalytic reactions can be carried out. For preparation of dendimer-metal nanocomposite, a dendrimer solution containing an average of 55 Yb+3 ions per dendrimer was prepared. Prior to reduction, the pH of this solution was adjusted to 7.5 using NaOH. NaBH4 was used to reduce the dendrimer-encapsulated Yb+3 to the zerovalent metal. The pH of the resulting solution was then adjusted to 3, using HClO4, to decompose excess BH4-. The UV-Vis absorption spectra of the mixture were recorded to ensure the formation of Yb-G5-NH2 complex. High-resolution electron microscopy (HRTEM) and size distribution results provide additional information about dendimer-metal nanocomposite shape, size, and size distribution of the particles. The resulting mixture was irradiated in Tehran Research Reactor 2h and neutron fluxes were 3×1011 n/cm2.Sec and the specific activity was 7MBq. Radiochemical and chemical and radionuclide quality control testes were carried. Gamma Spectroscopy and High-performance Liquid Chromatography HPLC, Thin-Layer Chromatography TLC were recorded. The injection of resulting solution to solid tumor in mice shows that it could be resized the tumor. The studies about solid tumors and nano composites show that ytterbium encapsulated-dendrimer radiopharmaceutical could be introduced as a new therapeutic for the treatment of solid tumors.Keywords: nano-radio pharmaceutical, ytterbium, PAMAM, dendrimers
Procedia PDF Downloads 492949 Photocapacitor Integrating Solar Energy Conversion and Energy Storage
Authors: Jihuai Wu, Zeyu Song, Zhang Lan, Liuxue Sun
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Solar energy is clean, open, and infinite, but solar radiation on the earth is fluctuating, intermittent, and unstable. So, the sustainable utilization of solar energy requires a combination of high-efficient energy conversion and low-loss energy storage technologies. Hence, a photo capacitor integrated with photo-electrical conversion and electric-chemical storage functions in single device is a cost-effective, volume-effective and functional-effective optimal choice. However, owing to the multiple components, multi-dimensional structure and multiple functions in one device, especially the mismatch of the functional modules, the overall conversion and storage efficiency of the photocapacitors is less than 13%, which seriously limits the development of the integrated system of solar conversion and energy storage. To this end, two typical photocapacitors were studied. A three-terminal photocapacitor was integrated by using perovskite solar cell as solar conversion module and symmetrical supercapacitor as energy storage module. A function portfolio management concept was proposed the relationship among various efficiencies during photovoltaic conversion and energy storage process were clarified. By harmonizing the energy matching between conversion and storage modules and seeking the maximum power points coincide and the maximum efficiency points synchronize, the overall efficiency of the photocapacitor surpassed 18 %, and Joule efficiency was closed to 90%. A voltage adjustable hybrid supercapacitor (VAHSC) was designed as energy storage module, and two Si wafers in series as solar conversion module, a three-terminal photocapacitor was fabricated. The VAHSC effectively harmonizes the energy harvest and storage modules, resulting in the current, voltage, power, and energy match between both modules. The optimal photocapacitor achieved an overall efficiency of 15.49% and Joule efficiency of 86.01%, along with excellent charge/discharge cycle stability. In addition, the Joule efficiency (ηJoule) was defined as the energy ratio of discharge/charge of the devices for the first time.Keywords: joule efficiency, perovskite solar cell, photocapacitor, silicon solar cell, supercapacitor
Procedia PDF Downloads 75948 Effects of School Culture and Curriculum on Gifted Adolescent Moral, Social, and Emotional Development: A Longitudinal Study of Urban Charter Gifted and Talented Programs
Authors: Rebekah Granger Ellis, Pat J. Austin, Marc P. Bonis, Richard B. Speaker, Jr.
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Using two psychometric instruments, this study examined social and emotional intelligence and moral judgment levels of more than 300 gifted and talented high school students enrolled in arts-integrated, academic acceleration, and creative arts charter schools in an ethnically diverse large city in the southeastern United States. Gifted and talented individuals possess distinguishable characteristics; these frequently appear as strengths, but often serious problems accompany them. Although many gifted adolescents thrive in their environments, some struggle in their school and community due to emotional intensity, motivation and achievement issues, lack of peers and isolation, identification problems, sensitivity to expectations and feelings, perfectionism, and other difficulties. These gifted students endure and survive in school rather than flourish. Gifted adolescents face special intrapersonal, interpersonal, and environmental problems. Furthermore, they experience greater levels of stress, disaffection, and isolation than non-gifted individuals due to their advanced cognitive abilities. Therefore, it is important to examine the long-term effects of participation in various gifted and talented programs on the socio-affective development of these adolescents. Numerous studies have researched moral, social, and emotional development in the areas of cognitive-developmental, psychoanalytic, and behavioral learning; however, in almost all cases, these three facets have been studied separately leading to many divergent theories. Additionally, various frameworks and models purporting to encourage the different socio-affective branches of development have been debated in curriculum theory, yet research is inconclusive on the effectiveness of these programs. Most often studied is the socio-affective domain, which includes development and regulation of emotions; empathy development; interpersonal relations and social behaviors; personal and gender identity construction; and moral development, thinking, and judgment. Examining development in these domains can provide insight into why some gifted and talented adolescents are not always successful in adulthood despite advanced IQ scores. Particularly whether emotional, social and moral capabilities of gifted and talented individuals are as advanced as their intellectual abilities and how these are related to each other. This mixed methods longitudinal study examined students in urban gifted and talented charter schools for (1) socio-affective development levels and (2) whether a particular environment encourages developmental growth. Research questions guiding the study: (1) How do academically and artistically gifted 10th and 11th grade students perform on psychological scales of social and emotional intelligence and moral judgment? Do they differ from the normative sample? Do gender differences exist among gifted students? (2) Do adolescents who attend distinctive gifted charter schools differ in developmental profiles? Students’ performances on psychometric instruments were compared over time and by program type. Assessing moral judgment (DIT-2) and socio-emotional intelligence (BarOn EQ-I: YV), participants took pre-, mid-, and post-tests during one academic school year. Quantitative differences in growth on these psychological scales (individuals and school-wide) were examined. If a school showed change, qualitative artifacts (culture, curricula, instructional methodology, stakeholder interviews) provided insight for environmental correlation.Keywords: gifted and talented programs, moral judgment, social and emotional intelligence, socio-affective education
Procedia PDF Downloads 179947 Design of Nanoreinforced Polyacrylamide-Based Hybrid Hydrogels for Bone Tissue Engineering
Authors: Anuj Kumar, Kummara M. Rao, Sung S. Han
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Bone tissue engineering has emerged as a potentially alternative method for localized bone defects or diseases, congenital deformation, and surgical reconstruction. The designing and the fabrication of the ideal scaffold is a great challenge, in restoring of the damaged bone tissues via cell attachment, proliferation, and differentiation under three-dimensional (3D) biological micro-/nano-environment. In this case, hydrogel system composed of high hydrophilic 3D polymeric-network that is able to mimic some of the functional physical and chemical properties of the extracellular matrix (ECM) and possibly may provide a suitable 3D micro-/nano-environment (i.e., resemblance of native bone tissues). Thus, this proposed hydrogel system is highly permeable and facilitates the transport of the nutrients and metabolites. However, the use of hydrogels in bone tissue engineering is limited because of their low mechanical properties (toughness and stiffness) that continue to posing challenges in designing and fabrication of tough and stiff hydrogels along with improved bioactive properties. For this purpose, in our lab, polyacrylamide-based hybrid hydrogels were synthesized by involving sodium alginate, cellulose nanocrystals and silica-based glass using one-step free-radical polymerization. The results showed good in vitro apatite-forming ability (biomineralization) and improved mechanical properties (under compression in the form of strength and stiffness in both wet and dry conditions), and in vitro osteoblastic (MC3T3-E1 cells) cytocompatibility. For in vitro cytocompatibility assessment, both qualitative (attachment and spreading of cells using FESEM) and quantitative (cell viability and proliferation using MTT assay) analyses were performed. The obtained hybrid hydrogels may potentially be used in bone tissue engineering applications after establishment of in vivo characterization.Keywords: bone tissue engineering, cellulose nanocrystals, hydrogels, polyacrylamide, sodium alginate
Procedia PDF Downloads 144946 The Relationship between Fight-Flight-Freeze System, Level of Expressed Emotion in Family, and Emotion Regulation Difficulties of University Students: Comparison Experienced to Inexperienced Non-Suicidal Self-Injury Students (NSSI)
Authors: Hyojung Shin, Munhee Kweon
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Non-suicide Self Injuri (NSSI) can be defined as the act of an individual who does not intend to die directly and intentionally damaging his or her body tissues. According to a study conducted by the Korean Ministry of Education in 2018, the NSSI is widely spreading among teenagers, with 7.9 percent of all middle school students and 6.4 percent of high school students reporting experience in NSSI. As such, it is understood that the first time of the NSSI is in adolescence. However, the NSSI may not start and stop at a certain time, but may last longer. However, despite the widespread prevalence of NSSI among teenagers, little is known about the process and maintenance of NSSI college students on a continuous development basis. Korea's NSSI research trends are mainly focused on individual internal vulnerabilities (high levels of painful emotions/awareness, lack of pain tolerance) and interpersonal vulnerabilities (poor communication skills and social problem solving), and little studies have been done on individuals' unique characteristics and environmental factors such as substrate or environmental vulnerability factors. In particular, environmental factors are associated with the occurrence of NSSI by acting as a vulnerability factor that can interfere with the emotional control of individuals, whereas individual factors play a more direct role by contributing to the maintenance of NSSI, so it is more important to consider this for personal environmental involvement in NSSI. This study focused on the Fight-Flight-Freeze System as a factor in the defensive avoidance system of Reward Sensitivity in individual factors. Also, Environmental factors include the level of expressed emotion in family. Wedig and Nock (2007) said that if parents with a self-critical cognitive style take the form of criticizing their children, the experience of NSSI increases. The high level of parental criticism is related to the increasing frequency of NSSI acts as well as to serious levels of NSSI. If the normal coping mechanism fails to control emotions, people want to overcome emotional difficulties even through NSSI, and emotional disturbances experienced by individuals within an unsupported social relationship increase vulnerability to NSSI. Based on these theories, this study is to find ways to prevent NSSI and intervene in counseling effectively by verifying the differences between the characteristics experienced NSSI persons and non-experienced NSSI persons. Therefore, the purpose of this research was to examine the relationship of Fight-Flight-Freeze System (FFFS), level of expressed emotion in family and emotion regulation difficulties, comparing those who experienced Non-Suicidal Self-Injury (NSSI) with those who did not experienced Non-Suicidal Self-Injury (NSSI). The data were collected from university students in Seoul Korea and Gyeonggi-do province. 99 subjects were experienced student of NSSI, while 375 were non- experienced student of NSSI. The results of this study are as follows. First, the result of t-test indicated that NSSI attempters showed a significant difference in fight-flight-freeze system, level of expressed emotion and emotion regulation difficulties, compared with non-attempters. Second, fight-flight-freeze system, level of expressed emotion in family and emotion regulation difficulties of NSSI attempters showed a significant difference in correlation. The correlation was significant only freeze system of fight-flight-freeze system, Level of expressed emotion in family and emotion regulation difficulties. Third, freeze system and level of expressed emotion in family predicted emotion regulation difficulties of NSSI attempters. Fight-freeze system and level of expressed emotion in family predicted emotion regulation difficulties of non-NSSI attempters. Lastly, Practical implications for counselors and limitations of this study are discussed.Keywords: fight-flight-freeze system, level of expressed emotion in family, emotion regulation difficulty, non-suicidal self injury
Procedia PDF Downloads 103945 Designing Function Knitted and Woven Upholstery Textile With SCOPY Film
Authors: Manar Y. Abd El-Aziz, Alyaa E. Morgham, Amira A. El-Fallal, Heba Tolla E. Abo El Naga
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Different textile materials are usually used in upholstery. However, upholstery parts may become unhealthy when dust accrues and bacteria raise on the surface, which negatively affects the user's health. Also, leather and artificial leather were used in upholstery but, leather has a high cost and artificial leather has a potential chemical risk for users. Researchers have advanced vegie leather made from bacterial cellulose a symbiotic culture of bacteria and yeast (SCOBY). SCOBY remains a gelatinous, cellulose biofilm discovered floating at the air-liquid interface of the container. But this leather still needs some enhancement for its mechanical properties. This study aimed to prepare SCOBY, produce bamboo rib knitted fabrics with two different stitch densities, and cotton woven fabric then laminate these fabrics with the prepared SCOBY film to enhance the mechanical properties of the SCOBY leather at the same time; add anti-microbial function to the prepared fabrics. Laboratory tests were conducted on the produced samples, including tests for function properties; anti-microbial, thermal conductivity and light transparency. Physical properties; thickness and mass per unit. Mechanical properties; elongation, tensile strength, young modulus, and peel force. The results showed that the type of the fabric affected significantly SCOBY properties. According to the test results, the bamboo knitted fabric with higher stitch density laminated with SCOBY was chosen for its tensile strength and elongation as the upholstery of a bed model with antimicrobial properties and comfortability in the headrest design. Also, the single layer of SCOBY was chosen regarding light transparency and lower thermal conductivity for the creation of a lighting unit built into the bed headboard.Keywords: anti-microbial, bamboo, rib, SCOPY, upholstery
Procedia PDF Downloads 55944 Compatibility of Sulphate Resisting Cement with Super and Hyper-Plasticizer
Authors: Alper Cumhur, Hasan Baylavlı, Eren Gödek
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Use of superplasticity chemical admixtures in concrete production is widespread all over the world and has become almost inevitable. Super-plasticizers (SPA), extend the setting time of concrete by adsorbing onto cement particles and provide concrete to preserve its fresh state workability properties. Hyper-plasticizers (HPA), as a special type of superplasticizer, provide the production of qualified concretes by increasing the workability properties of concrete, effectively. However, compatibility of cement with super and hyper-plasticizers is quite important for achieving efficient workability in order to produce qualified concretes. In 2011, the EN 197-1 standard is edited and cement classifications were updated. In this study, the compatibility of hyper-plasticizer and CEM I SR0 type sulphate resisting cement (SRC) that firstly classified in EN 197-1 is investigated. Within the scope of the experimental studies, a reference cement mortar was designed with a water/cement ratio of 0.50 confirming to EN 196-1. Fresh unit density of mortar was measured and spread diameters (at 0, 60, 120 min after mix preparation) and setting time of reference mortar were determined with flow table and Vicat tests, respectively. Three mortars are being re-prepared with using both super and hyper-plasticizer confirming to ASTM C494 by 0.50, 0.75 and 1.00% of cement weight. Fresh unit densities, spread diameters and setting times of super and hyper plasticizer added mortars (SPM, HPM) will be determined. Theoretical air-entrainment values of both SPMs and HPMs will be calculated by taking the differences between the densities of plasticizer added mortars and reference mortar. The flow table and Vicat tests are going to be repeated to these mortars and results will be compared. In conclusion, compatibility of SRC with SPA and HPA will be investigated. It is expected that optimum dosages of SPA and HPA will be determined for providing the required workability and setting conditions of SRC mortars, and the advantages/disadvantages of both SPA and HPA will be discussed.Keywords: CEM I SR0, hyper-plasticizer, setting time, sulphate resisting cement, super-plasticizer, workability
Procedia PDF Downloads 210943 Preclinical Studying of Stable Fe-Citrate Effect on 68Ga-Citrate Tissue Distribution
Authors: A. S. Lunev, A. A. Larenkov, O. E. Klementyeva, G. E. Kodina
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Background and aims: 68Ga-citrate is one of prospective radiopharmaceutical for PET-imaging of inflammation and infection. 68Ga-citrate is 67Ga-citrate analogue using since 1970s for SPECT-imaging. There's known rebinding reaction occurs past Ga-citrate injection and gallium (similar iron Fe3+) binds with blood transferrin. Then radiolabeled protein complex is delivered to pathological foci (inflammation/infection sites). But excessive gallium bindings with transferrin are cause of slow blood clearance, long accumulation time in foci (24-72 h) and exception of application possibility of the short-lived gallium-68 (T½ = 68 min). Injection of additional chemical agents (e.g. Fe3+ compounds) competing with radioactive gallium to the blood transferrin joining (blocking of its metal binding capacity) is one of the ways to solve formulated problem. This phenomenon can be used for correction of 68Ga-citrate pharmacokinetics for increasing of the blood clearance and accumulation in foci. The aim of real studying is research of effect of stable Fe-citrate on 68Ga-citrate tissue distribution. Materials and methods: 68Ga-citrate without/with extra injection of stable Fe-citrate (III) was injected nonlinear mice with inflammation models (aseptic soft tissue inflammation, lung infection, osteomyelitis). PET/X-RAY Genisys4 (Sofie Bioscience, USA) was used for non-invasive PET imaging (for 30, 60, 120 min past injection 68Ga-citrate) with subsequent reconstruction of imaging and their analysis (value of clearance, distribution volume). Scanning time is 10 min. Results and conclusions: I. v. injection of stable Fe-citrate blocks the metal-binding capability of transferrin serum and allows decreasing gallium-68 radioactivity in blood significantly and increasing accumulation in inflammation (3-5 time). It allows receiving more informative PET-images of inflammation early (for 30-60 min after injection). Pharmacokinetic parameters prove it. Noted there is no statistically significant difference between 68Ga-citrate accumulation for different inflammation model because PET imaging is indication of pathological processes and is not their identification.Keywords: 68Ga-citrate, Fe-citrate, PET imaging, mice, inflammation, infection
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