Search results for: liquid separation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3012

Search results for: liquid separation

2022 Basic Evaluation for Polyetherimide Membrane Using Spectroscopy Techniques

Authors: Hanan Alenezi

Abstract:

Membrane performance depends on the kind of solvent used in preparation. A membrane made by Polyetherimide (PEI) was evaluated for gas separation using X-Ray Diffraction (XRD), Scanning electron microscope (SEM), and Energy Dispersive X-Ray Spectroscopy (EDS). The purity and the thickness are detected to evaluate the membrane in order to optimize PEI membrane preparation.

Keywords: Energy Dispersive X-Ray Spectroscopy (EDS), Membrane, Polyetherimide PEI, Scanning electron microscope (SEM), Solvent, X-Ray Diffraction (XRD)

Procedia PDF Downloads 180
2021 Acculturation and Urban Related Identity of Turk and Kurd Internal Migrants

Authors: Melek Göregenli, Pelin Karakuş

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This present study explored the acculturation strategies and urban related identity of Turk and Kurd internal migrants from different regions of Turkey who resettled in three big cities in the west. Besides we aimed at a comparative analysis of acculturation strategies and urban-related identity of voluntary and internally displaced Kurd migrants. Particularly we explored the role of migration type, satisfaction with migration decision, urban-related identity and several socio demographic variables as predictors of Kurds’ integration strategy preference. The sample consisted of 412 adult participants from Izmir (64 females, 86 males); Ankara (76 females, 75 males); and Istanbul (43 females, 64 males and four unreported). In terms of acculturation strategies, assimilation was found to be the most preferred acculturation attitude among Turks whereas separation was found to be most endorsed acculturation attitude among Kurds. The migrants in Izmir were found to prefer assimilation whereas the migrants in Ankara prefer separation. Concerning urban-related identity mean scores, Turks reported higher urban-related identity scores than Kurds. Furthermore the internal migrants in Izmir were found to score higher in urban-related identity than the migrants living in Istanbul and Ankara. The results of the regression analysis revealed that gender, length of residence and migration type were the significant predictors of integration preference of Kurds. Thus, whereas gender and migration type had significant negative associations; length of residence had positive significant associations with Kurds integration preference. Compared to female Kurds, male Kurds were found to be more integrated. Furthermore, voluntary Kurd migrants were more favour of integration than internally displaced Kurds. The findings supported the significant associations between acculturation strategies and urban-related identity with either group.

Keywords: acculturation, forced migration, internal displacement, internal migration, Turkey, urban-related identity

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2020 Comparison of Anterolateral Thigh Flap with or without Acellular Dermal Matrix in Repair of Hypopharyngeal Squamous Cell Carcinoma Defect: A Retrospective Study

Authors: Yaya Gao, Bing Zhong, Yafeng Liu, Fei Chen

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Aim: The purpose of this study was to explore the difference between acellular dermal matrix (ADM) combined with anterolateral thigh (ALT) flap and ALT flap alone. Methods: HSCC patients were treated and divided into group A (ALT) and group B (ALT+ADM) between January 2014 and December 2018. We compared and analyzed the intraoperative information and postoperative outcomes of the patients. Results: There were 21 and 17 patients in group A and group B, respectively. The operation time, blood loss, defect size and anastomotic vessel selection showed no significant difference between two groups. The postoperative complications, including wound bleeding (n=0 vs. 1, p=0.459), wound dehiscence (n=0 vs. 1, p=0.459), wound infection (n=5vs.3, p=0.709), pharyngeal fistula (n=5vs.4, p=1.000) and hypoproteinemia (n=11 vs. 12, p=0.326) were comparable between the groups. Dysphagia at 6 months (number of liquid diets=0vs. 0; number of partial tube feedings=1vs. 1; number of total tube feedings=1vs. 0, p=0.655) also showed no significant differences. However, significant differences was observed in dysphagia at 12 months (number of liquid diets=0vs. 0; number of partial tube feedings=3 vs. 1; number of total tube feedings=10vs. 1, p=0.006). Conclusion: For HSCC patients, the use of the ALT flap combined ADM, compared to ALT treatment, showed better swallowing function at 12 months. The ALT flap combined ADM may serve as a safe and feasible alternative for selected HSCC patients.

Keywords: hypopharyngeal squamous cell carcinoma, anterolateral thigh free flap, acellular dermal matrix, reconstruction, dysphagia

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2019 Numerical Investigation of Pressure Drop in Core Annular Horizontal Pipe Flow

Authors: John Abish, Bibin John

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Liquid-liquid flow in horizontal pipe is investigated in order to reveal the flow patterns arising from the co-existed flow of oil and water. The main focus of the study is to identify the feasibility of reducing the pumping power requirements of petroleum transportation lines by having an annular flow of water around the thick oil core. This idea makes oil transportation cheaper and easier. The present study uses computational fluid dynamics techniques to model oil-water flows with liquids of similar density and varying viscosity. The simulation of the flow is conducted using commercial package Ansys Fluent. Flow domain modeling and grid generation accomplished through ICEM CFD. The horizontal pipe is modeled with two different inlets and meshed with O-Grid mesh. The standard k-ε turbulence scheme along with the volume of fluid (VOF) multiphase modeling method is used to simulate the oil-water flow. Transient flow simulations carried out for a total period of 30s showed significant reduction in pressure drop while employing core annular flow concept. This study also reveals the effect of viscosity ratio, mass flow rates of individual fluids and ration of superficial velocities on the pressure drop across the pipe length. Contours of velocity and volume fractions are employed along with pressure predictions to assess the effectiveness of this proposed concept quantitatively as well as qualitatively. The outcome of the present study is found to be very relevant for the petrochemical industries.

Keywords: computational fluid dynamics, core-annular flows, frictional flow resistance, oil transportation, pressure drop

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2018 Study of the Adsorptives Properties of Zeolites X Exchanged by the Cations Cu2 + and/or Zn2+

Authors: H. Hammoudi, S. Bendenia, I. Batonneau-Gener, A. Khelifa

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Applying growing zeolites is due to their intrinsic physicochemical properties: a porous structure, regular, generating a large free volume, a high specific surface area, acidic properties of interest to the origin of their activity, selectivity energy and dimensional, leading to a screening phenomenon, hence the name of molecular sieves is generally attributed to them. Most of the special properties of zeolites have been valued as direct applications such as ion exchange, adsorption, separation and catalysis. Due to their crystalline structure stable, their large pore volume and their high content of cation X zeolites are widely used in the process of adsorption and separation. The acidic properties of zeolites X and interesting selectivity conferred on them their porous structure is also have potential catalysts. The study presented in this manuscript is devoted to the chemical modification of an X zeolite by cation exchange. Ion exchange of zeolite NaX by Zn 2 + cations and / or Cu 2 + is gradually conducted by following the evolution of some of its characteristics: crystallinity by XRD, micropore volume by nitrogen adsorption. Once characterized, the different samples will be used for the adsorption of propane and propylene. Particular attention is paid thereafter, on the modeling of adsorption isotherms. In this vein, various equations of adsorption isotherms and localized mobile, some taking into account the adsorbate-adsorbate interactions, are used to describe the experimental isotherms. We also used the Toth equation, a mathematical model with three parameters whose adjustment requires nonlinear regression. The last part is dedicated to the study of acid properties of Cu (x) X, Zn (x) X and CuZn (x) X, with the adsorption-desorption of pyridine followed by IR. The effect of substitution at different rates of Na + by Cu2 + cations and / or Zn 2 +, on the crystallinity and on the textural properties was treated. Some results on the morphology of the crystallites and the thermal effects during a temperature rise, obtained by scanning electron microscopy and DTA-TGA thermal analyzer, respectively, are also reported. The acidity of our different samples was also studied. Thus, the nature and strength of each type of acidity are estimated. The evaluation of these various features will provide a comparison between Cu (x) X, Zn (x) X and CuZn (x) X. One study on adsorption of C3H8 and C3H6 in NaX, Cu (x) X , Zn (x) x and CuZn (x) x has been undertaken.

Keywords: adsorption, acidity, ion exchange, zeolite

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2017 Enhancing of Flame Retardancy and Hydrophobicity of Cotton by Coating a Phosphorous, Silica, Nitrogen Containing Bio-Flame Retardant Liquid for Upholstery Application

Authors: Li Maksym, Prabhakar M. N., Jung-Il Song

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In this study, a flame retardant and hydrophobic cotton textile were prepared by utilizing a renewable halogen-free bio-based solution based on chitosan, urea, and phytic acid, named bio-flame retardant liquid (BFL), through facile dip-coating technology. Deposition of BFL on the surface of the cotton was confirmed by Fourier-transform infrared spectroscopy and scanning electron microscope coupled with energy-dispersive X-ray spectrometer. Thermal and flame retardant properties of the cottons were studied with thermogravimetric analysis, differential scanning calorimetry, vertical flame test, cone calorimeter test. Only with 8.8% of dry weight gain treaded cotton showed self-extinguish properties during fire test. Cone calorimeter test revealed a reduction of peak heat release rate from 203.2 to 21 kW/m2 and total heat release from 20.1 to 2.8 MJ/m2. Incidentally, BFL remarkably improved the thermal stability of flame retardant cotton from expressed in an enhanced amount of char at 700 °C (6.7 vs. 33.5%). BFL initiates the formation of phosphorous and silica contain char layer whichrestrains the propagation of heat and oxygen to unburned materialstrengthen by the liberation of non-combustible gases, which reduce the concentration of flammable volatiles and oxygen hence reducing the flammability of cotton. In addition, hydrophobicity and specific ignition test for upholstery application were performed. In conjunction, the proposed flame retardant cotton is potentially translatable to be utilized as upholstery materials in public transport.

Keywords: cotton farbic, flame retardancy, surface coating, intumescent mechanism

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2016 Purification of Eicosapentaenoic Acid (EPA) and Docosahexaenoic Acid (DHA) from Fish Oil Using HPLC Method and Investigation of Their Antibacterial Effects on Some Pathogenic Bacteria

Authors: Yılmaz Uçar, Fatih Ozogul, Mustafa Durmuş, Yesim Ozogul, Ali Rıza Köşker, Esmeray Kuley Boğa, Deniz Ayas

Abstract:

The aim of this study was to purified eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), that are essential oils from trout oil, using high-performance liquid chromatography (HPLC) method, bioconverted EPA and DHA into bioconverted EPA (bEPA), bioconverted DHA (bDHA) extracts by P. aeruginosa PR3. Moreover, in vitro antibacterial activity of bEPA and bDHA was investigated using disc diffusion methods and minimum inhibitory concentration (MIC). EPA and DHA concentration of 11.1% and 15.9% in trout oil increased in 58.64% and 40.33% after HPLC optimisation, respectively. In this study, EPA and DHA enriched products were obtained which are to be used as valuable supplements for food and pharmaceutical purposes. The bioconverted EPA and DHA exhibited antibacterial activities against two Gram-positive bacteria (Listeria monocytogenes ATCC 7677 and Staphylococcus aureus ATCC 29213) and six Gram-negative bacteria (Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC700603, Enterococcus faecalis ATCC 29212, Aeromonas hydrophila NCIMB 1135, and Salmonella Paratyphi A NCTC 13). Inhibition zones and MIC value of bEPA and bDHA against bacterial strains ranged from 7 to 12 mm and from 350 to 2350 μg/mL, respectively. Our results suggested that the crude extracts of bioconversion of EPA and DHA by P. aeruginosa PR3 can be considered as promising antimicrobials in improving food safety by controlling foodborne pathogens.

Keywords: High-Performance Liquid Chromatography (HPLC), docosahexaenoic acid, DHA, eicosapentaenoic acid, EPA, minimum inhibitory concentration, MIC, Pseudomonas aeruginosa PR3

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2015 Determination of Rare Earth Element Patterns in Uranium Matrix for Nuclear Forensics Application: Method Development for Inductively Coupled Plasma Mass Spectrometry (ICP-MS) Measurements

Authors: Bernadett Henn, Katalin Tálos, Éva Kováss Széles

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During the last 50 years, the worldwide permeation of the nuclear techniques induces several new problems in the environmental and in the human life. Nowadays, due to the increasing of the risk of terrorism worldwide, the potential occurrence of terrorist attacks using also weapon of mass destruction containing radioactive or nuclear materials as e.g. dirty bombs, is a real threat. For instance, the uranium pellets are one of the potential nuclear materials which are suitable for making special weapons. The nuclear forensics mainly focuses on the determination of the origin of the confiscated or found nuclear and other radioactive materials, which could be used for making any radioactive dispersive device. One of the most important signatures in nuclear forensics to find the origin of the material is the determination of the rare earth element patterns (REE) in the seized or found radioactive or nuclear samples. The concentration and the normalized pattern of the REE can be used as an evidence of uranium origin. The REE are the fourteen Lanthanides in addition scandium and yttrium what are mostly found together and really low concentration in uranium pellets. The problems of the REE determination using ICP-MS technique are the uranium matrix (high concentration of uranium) and the interferences among Lanthanides. In this work, our aim was to develop an effective chemical sample preparation process using extraction chromatography for separation the uranium matrix and the rare earth elements from each other following some publications can be found in the literature and modified them. Secondly, our purpose was the optimization of the ICP-MS measuring process for REE concentration. During method development, in the first step, a REE model solution was used in two different types of extraction chromatographic resins (LN® and TRU®) and different acidic media for environmental testing the Lanthanides separation. Uranium matrix was added to the model solution and was proved in the same conditions. Methods were tested and validated using REE UOC (uranium ore concentrate) reference materials. Samples were analyzed by sector field mass spectrometer (ICP-SFMS).

Keywords: extraction chromatography, nuclear forensics, rare earth elements, uranium

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2014 Numerical Simulation of Flow and Heat Transfer Characteristics with Various Working Conditions inside a Reactor of Wet Scrubber

Authors: Jonghyuk Yoon, Hyoungwoon Song, Youngbae Kim, Eunju Kim

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Recently, with the rapid growth of semiconductor industry, lots of interests have been focused on after treatment system that remove the polluted gas produced from semiconductor manufacturing process, and a wet scrubber is the one of the widely used system. When it comes to mechanism of removing the gas, the polluted gas is removed firstly by chemical reaction in a reactor part. After that, the polluted gas stream is brought into contact with the scrubbing liquid, by spraying it with the liquid. Effective design of the reactor part inside the wet scrubber is highly important since removal performance of the polluted gas in the reactor plays an important role in overall performance and stability. In the present study, a CFD (Computational Fluid Dynamics) analysis was performed to figure out the thermal and flow characteristics inside unit a reactor of wet scrubber. In order to verify the numerical result, temperature distribution of the numerical result at various monitoring points was compared to the experimental result. The average error rates (12~15%) between them was shown and the numerical result of temperature distribution was in good agreement with the experimental data. By using validated numerical method, the effect of the reactor geometry on heat transfer rate was also taken into consideration. Uniformity of temperature distribution was improved about 15%. Overall, the result of present study could be useful information to identify the fluid behavior and thermal performance for various scrubber systems. This project is supported by the ‘R&D Center for the reduction of Non-CO₂ Greenhouse gases (RE201706054)’ funded by the Korea Ministry of Environment (MOE) as the Global Top Environment R&D Program.

Keywords: semiconductor, polluted gas, CFD (Computational Fluid Dynamics), wet scrubber, reactor

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2013 Influence of Temperature and Precipitation Changes on Desertification

Authors: Kukuri Tavartkiladze, Nana Bolashvili

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The purpose of this paper was separation and study of the part of structure regime, which directly affects the process of desertification. A simple scheme was prepared for the assessment of desertification process; surface air temperature and precipitation for the years of 1936-2009 were analyzed.  The map of distribution of the Desertification Contributing Coefficient in the territory of Georgia was compiled. The simple scheme for identification of the intensity of the desertification contributing process has been developed and the illustrative example of its practical application for the territory of Georgia has been conducted.

Keywords: aridity, climate change, desertification, precipitation

Procedia PDF Downloads 335
2012 Resistance Analysis for a Trimaran

Authors: C. M. De Marco Muscat-Fenech, A. M. Grech La Rosa

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Importance has been given to resistance analysis for various types of vessels; however explicit guidelines applied to multihull vessels have not been clearly defined. The purpose of this investigation is to highlight the importance of the vessel’s layout in terms of three axes positioning, the transverse (separation), the longitudinal (stagger) and the vertical (draught) with respect to resistance analysis. A vessel has the potential to experience less resistance, at a particular range of speeds, for a vast selection of hull positioning. Many potential layouts create opportunities of various design for both the commercial and leisure market.

Keywords: multihull, reistance, trimaran, vessels

Procedia PDF Downloads 475
2011 Appearance of Ciguatoxin Fish in Atlantic Europe Waters

Authors: J. Bravo, F. Cabrera Suárez, B. Vega, L. Román, M. Martel, F. Acosta

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Ciguatera fish poisoning (CFP) is the most common non-bacterial intoxication in the world caused by ingestion of fish with bio-accumulated ciguatoxins (CTXs). It is typical in tropical and subtropical areas, mainly affecting the Caribbean Sea, Polynesia and other areas in the Pacific and Indian Oceans. Interest in Europe by the CFP is increasing in recent years as more and more cases in European hospitals are appearing, usually by people who have consumed ciguatoxin imported fish or have travelled to areas of risk for this poisoning. Since 2004 a series of poisonings raised the question of a possible occurrence of ciguatoxin in Europe, especially in the area of Macaronesia in the East Atlantic temperate zone. Furthermore, some studies have identified the presence of Gambierdiscus spp. in waters surrounding the Canary Islands and Madeira, a toxic dinoflagellate related to this poisoning. The toxin accumulates and concentrates through the food chain and affects to the end of the chain, the human consumer. Fish were collected from the Canary Islands waters and the toxin has been extracted and purified by using acetone and liquid/liquid partition in order to eliminate the excess of fatty acids that may interfere with the detection of the toxin. The fish extracts were inoculated in Neuroblastoma (neuro-2a) cells. After 24-h cell viability was used as an endpoint for cytotoxic effects measurement. Since 2011 our laboratory is collecting data for species such Seriola spp., Epinephelus spp., Makaira spp., Pomatomus spp., Xiphias spp., and Acantocybium spp., from all islands and including the sports fishing and professional activities, we obtained a 8% of fish that have ciguatoxin in their muscle. With these results, we conclude that the island where fishing and fish size affects the probability of catching a fish with the ciguatoxin.

Keywords: Canary Islands, ciguatera fish poisoning, ciguatoxin, Europe

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2010 Phosphorous Acid: An Efficient and Recyclable Liquid Catalyst for the Synthesis of α-Aminophosphonates

Authors: Hellal Abdelkader, Chafaa Salah, Touafri Lasnouni

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A simple, efficient and general method has been developed for the high diastereoselective synthesis of diethyl α-aminophosphonates in water through “one-pot” three-component reaction of aromatic aldehydes, aminophenols and dialkyl phosphites in the presence of a low catalytic amount (10mol%) of phosphorous acid as highly stable catalyst is described.

Keywords: DFT, HOMO-LUMO, phosphonic acid, aminophenols

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2009 Control of the Sustainability of Fresh Cheese in Order to Extend the Shelf-Life of the Product

Authors: Radovan Čobanović, Milica Rankov Šicar

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The fresh cheese is in the group of perishable food which cannot be kept a long period of time. The study of sustainability have been done in order to extend the shelf-life of the product which was 15 days. According to the plan of sustainability it was defined that 35 samples had to be stored for 30 days at 2°C−6°C and analyzed every 7th day from the day of reception until 30th day. Shelf life of the cheese has expired during the study of sustainability in the period between 15th and 30th day of analyses. Cheese samples were subjected to sensory analysis (appearance, odor, taste, color, aroma) and bacteriological analyzes (Listeria monocytogenes, Salmonella spp., Bacillus cereus, Staphylococcus aureus and total plate count) according to Serbian state regulation. All analyses were tested according to ISO methodology: sensory analysis ISO 6658, Listeria monocytogenes ISO 11 290-1, Salmonella spp ISO 6579, Bacillus cereus ISO 7932, Staphylococcus aureus ISO 6888-1, and total plate count ISO 4833. Analyses showed that after fifteen days of storage at a temperature defined by the manufacturers and within the product's shelf life, the cheese did not have any noticeable changes in sensory characteristics. Smell and taste are unaffected there was no separation of whey and there was not presence of strange smell or taste. As far as microbiological analyses are concerned neither one pathogen was detected and total plate count was at level of 103 cfu/g. After expiry of shelf life in a period of 15th and 30th day of storage, the analysis showed that there was a separation of whey on the surface. Along the edge of the container was present a dried part of cheese and sour-milky smell and taste were very weakly expressed. Concerning the microbiological analyses there still were not positive results for pathogen microorganisms but the total plate count was at a level of 106cfu/g. Based on the obtained results it can be concluded that this product cannot have longer shelf life than shelf life which is already defined because there are a sensory changes that would certainly have influence on decision of customers when purchase of this product is concerned.

Keywords: sustainability, fresh cheese, shelf-life, product

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2008 Separate Production of Hydrogen and Methane from Ethanol Wastewater Using Two-Stage UASB: Micronutrient Transportation

Authors: S. Jaikeaw, S. Chavadej

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The objective of this study was to determine the effects of COD loading rate on hydrogen and methane production and micronutrient transportation using a two-stage upflow anaerobic sludge blanket (UASB) system under mesophilic temperature (37°C) with a constant recycle ratio of 1:1 (final effluent flow rate: feed flow rate). The first (hydrogen) UASB unit having 4 L liquid holding volume was controlled at pH 5.5 but the second (methane) UASB unit having 24 L liquid holding volume had no pH control. The two-stage UASB system operated at different COD loading rates from 8 to 20 kg/m³d based on total UASB working volume. The results showed that, at the optimum COD loading rate of 13 kg/m³d, the produced gas from the hydrogen UASB unit contained 1.5% H₂, 16.5% CH₄, and 82% CO₂ with H₂S of 252 ppm and also provided a hydrogen yield of 1.66 mL/g COD removed (or 0.56 mL/g COD applied) and a specific hydrogen production rate of 156.85 ml H₂/LRd (or 5.12 ml H₂/g MLVSS d). Under the optimum COD loading rate, the produced gas from the methane UASB unit mainly contained methane and carbon dioxide without hydrogen of 74 and 26%, respectively with hydrogen sulfide of 287 ppm and the system also provided a maximum methane yield of 407.00 mL/g COD removed (or 263.23 mL/g COD applied) and a specific methane production rate of 2081.44 ml CH₄/LRd (or 99.75 ml CH₄/g MLVSS d). Under the optimum COD loading rate, all micronutrients markedly dropped by the sulfide precipitation reactions. The reduction of micronutrients mostly appeared in the methane UASB unit. Under the studied conditions, both Co and Ni were found to be greatly precipitated out, causing the deficiency to microbial activity. It is hypothesized that an addition of both Co and Ni can improve the methanogenic activity.

Keywords: hydrogen and methane production, ethanol wastewater, a two-stage upflow anaerobic blanket (UASB) system, mesophillic temperature, microbial concentration (MLVSS), micronutrients

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2007 Prediction of California Bearing Ratio of a Black Cotton Soil Stabilized with Waste Glass and Eggshell Powder using Artificial Neural Network

Authors: Biruhi Tesfaye, Avinash M. Potdar

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The laboratory test process to determine the California bearing ratio (CBR) of black cotton soils is not only overpriced but also time-consuming as well. Hence advanced prediction of CBR plays a significant role as it is applicable In pavement design. The prediction of CBR of treated soil was executed by Artificial Neural Networks (ANNs) which is a Computational tool based on the properties of the biological neural system. To observe CBR values, combined eggshell and waste glass was added to soil as 4, 8, 12, and 16 % of the weights of the soil samples. Accordingly, the laboratory related tests were conducted to get the required best model. The maximum CBR value found at 5.8 at 8 % of eggshell waste glass powder addition. The model was developed using CBR as an output layer variable. CBR was considered as a function of the joint effect of liquid limit, plastic limit, and plastic index, optimum moisture content and maximum dry density. The best model that has been found was ANN with 5, 6 and 1 neurons in the input, hidden and output layer correspondingly. The performance of selected ANN has been 0.99996, 4.44E-05, 0.00353 and 0.0067 which are correlation coefficient (R), mean square error (MSE), mean absolute error (MAE) and root mean square error (RMSE) respectively. The research presented or summarized above throws light on future scope on stabilization with waste glass combined with different percentages of eggshell that leads to the economical design of CBR acceptable to pavement sub-base or base, as desired.

Keywords: CBR, artificial neural network, liquid limit, plastic limit, maximum dry density, OMC

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2006 Lipid Extraction from Microbial Cell by Electroporation Technique and Its Influence on Direct Transesterification for Biodiesel Synthesis

Authors: Abu Yousuf, Maksudur Rahman Khan, Ahasanul Karim, Amirul Islam, Minhaj Uddin Monir, Sharmin Sultana, Domenico Pirozzi

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Traditional biodiesel feedstock like edible oils or plant oils, animal fats and cooking waste oil have been replaced by microbial oil in recent research of biodiesel synthesis. The well-known community of microbial oil producers includes microalgae, oleaginous yeast and seaweeds. Conventional transesterification of microbial oil to produce biodiesel is lethargic, energy consuming, cost-ineffective and environmentally unhealthy. This process follows several steps such as microbial biomass drying, cell disruption, oil extraction, solvent recovery, oil separation and transesterification. Therefore, direct transesterification of biodiesel synthesis has been studying for last few years. It combines all the steps in a single reactor and it eliminates the steps of biomass drying, oil extraction and separation from solvent. Apparently, it seems to be cost-effective and faster process but number of difficulties need to be solved to make it large scale applicable. The main challenges are microbial cell disruption in bulk volume and make faster the esterification reaction, because water contents of the medium sluggish the reaction rate. Several methods have been proposed but none of them is up to the level to implement in large scale. It is still a great challenge to extract maximum lipid from microbial cells (yeast, fungi, algae) investing minimum energy. Electroporation technique results a significant increase in cell conductivity and permeability caused due to the application of an external electric field. Electroporation is required to alter the size and structure of the cells to increase their porosity as well as to disrupt the microbial cell walls within few seconds to leak out the intracellular lipid to the solution. Therefore, incorporation of electroporation techniques contributed in direct transesterification of microbial lipids by increasing the efficiency of biodiesel production rate.

Keywords: biodiesel, electroporation, microbial lipids, transesterification

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2005 Comparison of Physicochemical Properties of Catfish Myofibrillar and Sarcoplasmic Protein Hydrolysates and Characterization of Their Bioactive Peptides

Authors: Leila Najafian

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Sarcoplasmic protein hydrolysates (SPHs) and myofibrillar protein hydrolysates (MPHs) from patin (Pangasius sutchi) were produced using two types of proteases: Papain and Alcalase. 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS) radical scavenging activities and metal chelating activity assays for antioxidant activities were carried out on the SPHs and MPHs. The hydrolysates were isolated and purified by ultrafiltration, gel filtration and reverse phase high-performance liquid chromatography (RP-HPLC) and liquid chromatography with tandem mass spectrometry detection (LC-MS/MS) was used in identifying peptide sequences. The results showed that when the DH of MPHs increased, the protein solubility increased, while the highest amount of the protein solubility of SPHs was after 60 min incubation. The effect of DH on antioxidant activities of SPHs and MPHs was investigated. Among the hydrolysates, papain-MPH and Alcalase-SPH, which had the highest antioxidant activities, were purified. The potent fractions obtained from RP-HPLC of sarcoplasmic (SI 3 fraction) and myofibrillar (MI 4 fraction) hydrolysates showed the highest DPPH radical scavenging activity. The FVNQPYLLYSVHMK peptide for MPH and the LVVDIPAALQHA peptide for SPH exhibited the highest antioxidant activity. The presence of hydrophobic and hydrophilic amino acids, namely leucine (L), valine (V), phenylalanine (F), histidine (H) and proline (P), in the peptide sequences of SPH and MPH are believed to contribute to high antioxidant activity. Hence, SPH and MPH from patin have the potential as a natural functional ingredient in food and pharmaceutical industry.

Keywords: patin (Pangasius sutchi), protein hydrolysates, antioxidative peptides, mass spectrometry

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2004 Quantification of Lawsone and Adulterants in Commercial Henna Products

Authors: Ruchi B. Semwal, Deepak K. Semwal, Thobile A. N. Nkosi, Alvaro M. Viljoen

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The use of Lawsonia inermis L. (Lythraeae), commonly known as henna, has many medicinal benefits and is used as a remedy for the treatment of diarrhoea, cancer, inflammation, headache, jaundice and skin diseases in folk medicine. Although widely used for hair dyeing and temporary tattooing, henna body art has popularized over the last 15 years and changed from being a traditional bridal and festival adornment to an exotic fashion accessory. The naphthoquinone, lawsone, is one of the main constituents of the plant and responsible for its dyeing property. Henna leaves typically contain 1.8–1.9% lawsone, which is used as a marker compound for the quality control of henna products. Adulteration of henna with various toxic chemicals such as p-phenylenediamine, p-methylaminophenol, p-aminobenzene and p-toluenodiamine to produce a variety of colours, is very common and has resulted in serious health problems, including allergic reactions. This study aims to assess the quality of henna products collected from different parts of the world by determining the lawsone content, as well as the concentrations of any adulterants present. Ultra high performance liquid chromatography-mass spectrometry (UPLC-MS) was used to determine the lawsone concentrations in 172 henna products. Separation of the chemical constituents was achieved on an Acquity UPLC BEH C18 column using gradient elution (0.1% formic acid and acetonitrile). The results from UPLC-MS revealed that of 172 henna products, 11 contained 1.0-1.8% lawsone, 110 contained 0.1-0.9% lawsone, whereas 51 samples did not contain detectable levels of lawsone. High performance thin layer chromatography was investigated as a cheaper, more rapid technique for the quality control of henna in relation to the lawsone content. The samples were applied using an automatic TLC Sampler 4 (CAMAG) to pre-coated silica plates, which were subsequently developed with acetic acid, acetone and toluene (0.5: 1.0: 8.5 v/v). A Reprostar 3 digital system allowed the images to be captured. The results obtained corresponded to those from UPLC-MS analysis. Vibrational spectroscopy analysis (MIR or NIR) of the powdered henna, followed by chemometric modelling of the data, indicates that this technique shows promise as an alternative quality control method. Principal component analysis (PCA) was used to investigate the data by observing clustering and identifying outliers. Partial least squares (PLS) multivariate calibration models were constructed for the quantification of lawsone. In conclusion, only a few of the samples analysed contain lawsone in high concentrations, indicating that they are of poor quality. Currently, the presence of adulterants that may have been added to enhance the dyeing properties of the products, is being investigated.

Keywords: Lawsonia inermis, paraphenylenediamine, temporary tattooing, lawsone

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2003 Numerical Investigation of Phase Change Materials (PCM) Solidification in a Finned Rectangular Heat Exchanger

Authors: Mounir Baccar, Imen Jmal

Abstract:

Because of the rise in energy costs, thermal storage systems designed for the heating and cooling of buildings are becoming increasingly important. Energy storage can not only reduce the time or rate mismatch between energy supply and demand but also plays an important role in energy conservation. One of the most preferable storage techniques is the Latent Heat Thermal Energy Storage (LHTES) by Phase Change Materials (PCM) due to its important energy storage density and isothermal storage process. This paper presents a numerical study of the solidification of a PCM (paraffin RT27) in a rectangular thermal storage exchanger for air conditioning systems taking into account the presence of natural convection. Resolution of continuity, momentum and thermal energy equations are treated by the finite volume method. The main objective of this numerical approach is to study the effect of natural convection on the PCM solidification time and the impact of fins number on heat transfer enhancement. It also aims at investigating the temporal evolution of PCM solidification, as well as the longitudinal profiles of the HTF circling in the duct. The present research undertakes the study of two cases: the first one treats the solidification of PCM in a PCM-air heat exchanger without fins, while the second focuses on the solidification of PCM in a heat exchanger of the same type with the addition of fins (3 fins, 5 fins, and 9 fins). Without fins, the stratification of the PCM from colder to hotter during the heat transfer process has been noted. This behavior prevents the formation of thermo-convective cells in PCM area and then makes transferring almost conductive. In the presence of fins, energy extraction from PCM to airflow occurs at a faster rate, which contributes to the reduction of the discharging time and the increase of the outlet air temperature (HTF). However, for a great number of fins (9 fins), the enhancement of the solidification process is not significant because of the effect of confinement of PCM liquid spaces for the development of thermo-convective flow. Hence, it can be concluded that the effect of natural convection is not very significant for a high number of fins. In the optimum case, using 3 fins, the increasing temperature of the HTF exceeds approximately 10°C during the first 30 minutes. When solidification progresses from the surfaces of the PCM-container and propagates to the central liquid phase, an insulating layer will be created in the vicinity of the container surfaces and the fins, causing a low heat exchange rate between PCM and air. As the solid PCM layer gets thicker, a progressive regression of the field of movements is induced in the liquid phase, thus leading to the inhibition of heat extraction process. After about 2 hours, 68% of the PCM became solid, and heat transfer was almost dominated by conduction mechanism.

Keywords: heat transfer enhancement, front solidification, PCM, natural convection

Procedia PDF Downloads 186
2002 Performance Evaluation of Next Generation Shale Stabilizer

Authors: N. K. Thakur

Abstract:

A major proportion of the formations drilled for the production of hydrocarbons consists of clay containing shales. The petroleum industry has hugely investigated the role of clay minerals and their subsequent effect on wellbore stability during the drilling and production of hydrocarbons. It has been found that when the shale formation comes in contact with water-based drilling fluid, the interaction of clay minerals like montmorillonite with infiltrated water leads to hydration of the clay minerals, which causes shale swelling. When shale swelling proceeds further, it may lead to major drilling complications like caving, pipe sticking, which invariably influences wellbore stability, wellbore diameter, the mechanical strength of shale, stress distribution in the wellbore, etc. These problems ultimately lead to an increase in nonproductive time and additional costs during drilling. Several additives are used to prevent shale instability. Among the popular additives used for shale inhibition in drilling muds, ionic liquids and nanoparticles are emerging to be the best additives. The efficiency of the proposed additives will be studied and compared with conventional clay inhibitors like KCl. The main objective is to develop a highly efficient water-based mud for mitigating shale instability and reducing fluid loss which is environmentally friendly and does not alter the formation permeability. The use of nanoparticles has been exploited to enhance the rheological and fluid loss properties in water-based drilling fluid ionic liquid have attracted significant research interest due to its unique thermal stability. It is referred to as ‘green chemical’. The preliminary experimental studies performed are promising. The application of more effective mud additives is always desirable to make the drilling process techno-economically proficient.

Keywords: ionic liquid, shale inhibitor, wellbore stability, unconventional

Procedia PDF Downloads 192
2001 Multi-Criteria Optimal Management Strategy for in-situ Bioremediation of LNAPL Contaminated Aquifer Using Particle Swarm Optimization

Authors: Deepak Kumar, Jahangeer, Brijesh Kumar Yadav, Shashi Mathur

Abstract:

In-situ remediation is a technique which can remediate either surface or groundwater at the site of contamination. In the present study, simulation optimization approach has been used to develop management strategy for remediating LNAPL (Light Non-Aqueous Phase Liquid) contaminated aquifers. Benzene, toluene, ethyl benzene and xylene are the main component of LNAPL contaminant. Collectively, these contaminants are known as BTEX. In in-situ bioremediation process, a set of injection and extraction wells are installed. Injection wells supply oxygen and other nutrient which convert BTEX into carbon dioxide and water with the help of indigenous soil bacteria. On the other hand, extraction wells check the movement of plume along downstream. In this study, optimal design of the system has been done using PSO (Particle Swarm Optimization) algorithm. A comprehensive management strategy for pumping of injection and extraction wells has been done to attain a maximum allowable concentration of 5 ppm and 4.5 ppm. The management strategy comprises determination of pumping rates, the total pumping volume and the total running cost incurred for each potential injection and extraction well. The results indicate a high pumping rate for injection wells during the initial management period since it facilitates the availability of oxygen and other nutrients necessary for biodegradation, however it is low during the third year on account of sufficient oxygen availability. This is because the contaminant is assumed to have biodegraded by the end of the third year when the concentration drops to a permissible level.

Keywords: groundwater, in-situ bioremediation, light non-aqueous phase liquid, BTEX, particle swarm optimization

Procedia PDF Downloads 443
2000 Generation of Charged Nanoparticles and Their Contribution to the Thin Film and Nanowire Growth during Chemical Vapour Deposition

Authors: Seung-Min Yang, Seong-Han Park, Sang-Hoon Lee, Seung-Wan Yoo, Chan-Soo Kim, Nong-Moon Hwang

Abstract:

The theory of charged nanoparticles suggested that in many Chemical Vapour Depositions (CVD) processes, Charged Nanoparticles (CNPs) are generated in the gas-phase and become a building block of thin films and nanowires. Recently, the nanoparticle-based crystallization has become a big issue since the growth of nanorods or crystals by the building block of nanoparticles was directly observed by transmission electron microscopy observations in the liquid cell. In an effort to confirm charged gas-phase nuclei, that might be generated under conventional processing conditions of thin films and nanowires during CVD, we performed an in-situ measurement using differential mobility analyser and particle beam mass spectrometer. The size distribution and number density of CNPs were affected by process parameters such as precursor flow rate and working temperature. It was shown that many films and nanostructures, which have been believed to grow by individual atoms or molecules, actually grow by the building blocks of such charged nuclei. The electrostatic interaction between CNPs and the growing surface induces the self-assembly into films and nanowires. In addition, the charge-enhanced atomic diffusion makes CNPs liquid-like quasi solid. As a result, CNPs tend to land epitaxial on the growing surface, which results in the growth of single crystalline nanowires with a smooth surface.

Keywords: chemical vapour deposition, charged nanoparticle, electrostatic force, nanostructure evolution, differential mobility analyser, particle beam mass spectrometer

Procedia PDF Downloads 450
1999 Separation of Urinary Proteins with Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis in Patients with Secondary Nephropathies

Authors: Irena Kostovska, Katerina Tosheska Trajkovska, Svetlana Cekovska, Julijana Brezovska Kavrakova, Hristina Ampova, Sonja Topuzovska, Ognen Kostovski, Goce Spasovski, Danica Labudovic

Abstract:

Background: Proteinuria is an important feature of secondary nephropathies. The quantitative and qualitative analysis of proteinuria plays an important role in determining the types of proteinuria (glomerular, tubular and mixed), in the diagnosis and prognosis of secondary nephropathies. The damage of the glomerular basement membrane is responsible for a proteinuria characterized by the presence of large amounts of protein with high molecular weights such as albumin (69 kilo Daltons-kD), transferrin (78 kD) and immunoglobulin G (150 kD). An insufficiency of proximal tubular function is the cause of a proteinuria characterized by the presence of proteins with low molecular weight (LMW), such as retinol binding protein (21 kD) and α1-microglobulin (31 kD). In some renal diseases, a mixed glomerular and tubular proteinuria is frequently seen. Sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) is the most widely used method of analyzing urine proteins for clinical purposes. The main aim of the study is to determine the type of proteinuria in the most common secondary nephropathies such as diabetic, hypertensive nephropathy and preeclampsia. Material and methods: In this study were included 90 subjects: subjects with diabetic nephropathy (n=30), subjects with hypertensive nephropahty (n=30) and pregnant women with preeclampsia (n=30). We divided all subjects according to UM/CR into three subgroups: macroalbuminuric (UM/CR >300 mg/g), microalbuminuric (UM/CR 30-300 mg/g) and normolabuminuric (UM/CR<30 mg/g). In all subjects, we measured microalbumin and creatinine in urine with standard biochemical methods. Separation of urinary proteins was performed by SDS-PAGE, in several stages: linear gel preparation (4-22%), treatment of urinary samples before their application on the gel, electrophoresis, gel fixation, coloring with Coomassie blue, and identification of the separated protein fractions based on standards with exactly known molecular weight. Results: According to urinary microalbumin/creatinin ratio in group of subject with diabetic nephropathy, nine patients were macroalbuminuric, while 21 subject were microalbuminuric. In group of subjects with hypertensive nephropathy, we found macroalbuminuria (n=4), microalbuminuria (n=20) and normoalbuminuria (n=6). All pregnant women with preeclampsia were macroalbuminuric. Electrophoretic separation of urinary proteins showed that in macroalbuminric patients with diabetic nephropathy 56% have mixed proteinuria, 22% have glomerular proteinuria and 22% have tubular proteinuria. In subgroup of subjects with diabetic nephropathy and microalbuminuria, 52% have glomerular proteinuria, 8% have tubular proteinuria, and 40% of subjects have normal electrophoretic findings. All patients with maroalbuminuria and hypertensive nephropathy have mixed proteinuria. In subgroup of patients with microalbuminuria and hypertensive nephropathy, we found: 32% with mixed proteinuria, 27% with normal findings, 23% with tubular, and 18% with glomerular proteinuria. In all normoalbuminruic patiens with hypertensive nephropathy, we detected normal electrophoretic findings. In group of subjects pregnant women with preeclampsia, we found: 81% with mixed proteinuria, 13% with glomerular, and 8% with tubular proteinuria. Conclusion: By SDS PAGE method, we detected that in patients with secondary nephropathies the most common type of proteinuria is mixed proteinuria, indicating both loss of glomerular permeability and tubular function. We can conclude that SDS PAGE is high sensitive method for detection of renal impairment in patients with secondary nephropathies.

Keywords: diabetic nephropathy, preeclampsia, hypertensive nephropathy, SDS PAGE

Procedia PDF Downloads 142
1998 Super-Hydrophilic TFC Membrane with High Stability in Oil

Authors: M. Obaid, Nasser A. M. Barakat, Fadali O.A

Abstract:

Low stability in oil media and the hydrophobicity problems of the ploysulfone electrospun membranes could be overcome in the present study. Synthesis of super-hydrophilic and highly stable in oil polysulfone electrospun nanofiber membrane was achieved by electrospinning of polysulfone solution containing NaOH salt followed by activation of the dried electrospun membrane by deposition of polyamide layer on the surface using m-phenylenediamine and 1,3,5-benzenetricarbonyl chloride. The introduced membrane has super-hydrophilicity characteristic (contact angle=3o), excellent stability in oil media and distinct performance in oil-water separation process.

Keywords: electrospinning, oil-degradability, membrane, nanofibers

Procedia PDF Downloads 478
1997 In Vitro Propagation in Barleria prionitis L. Via Callus Organogenesis

Authors: Rashmi Ranade, Neelu Joshi

Abstract:

Barleria prionitis L. is a well explored Indian medicinal plant valued for its stem and leaf which forms an important ingredient of many Ayurvedic formulations. It is used for the treatment of various disorders like toothache, bleeding gums, strengthening gums, whooping cough, inflammation, arthritis, enlargement of scrotum and sciatica etc. The plant is propagated vegetatively through stem cuttings. Frequent harvesting of this plant has led to the shortage of planting material, and it has acquired the status of vulnerable plant species. Plant tissue culture technology offers a very good alternative for propagation and conservation of such plant species. The present investigation was undertaken to develop in vitro regeneration protocol for B. prionitis L. via callus organogenesis pathway. Stem and leaf explants were used for this purpose. Different media and plant growth regulators were optimized to develop the protocol. The problem of phenol secretion and browning and in vitro cultures at the establishment phase was successfully curbed with the usage of antibrowning agents such as ascorbic acid and activated charcoal. Optimum shoot multiplication was achieved by the use of liquid media and incorporation of silver nitrate and TIBA (triiodobenzoic acid) into the media. High percent rooting (76%) was observed on WPM media supplemented with IBA (2.0 mg/l), IAA (0.5 mg/l), GA3(0.5) and activated charcoal(500 mg/l). The rooted plantlets were subjected to in vitro hardening on sterile potting mix (soil:farmyard manure:compost; 1:2:1) and acclimatized under greenhouse conditions. Around 85% survival of plantlets was recorded upon acclimatization. This lab scale protocol would be tested for in vitro scaling up production of B. prionitis L.

Keywords: explant browning, liquid culture, micropropagation, shoot multiplication, phenolic secretion

Procedia PDF Downloads 281
1996 The Role of Heat Pumps in the Decarbonization of European Regions

Authors: Domenico M. Mongelli, Michele De Carli, Laura Carnieletto, Filippo Busato

Abstract:

Europe's dependence on imported fossil fuels has been particularly highlighted by the Russian invasion of Ukraine. Limiting this dependency with a massive replacement of fossil fuel boilers with heat pumps for building heating is the goal of this work. Therefore, with the aim of diversifying energy sources and evaluating the potential use of heat pump technologies for residential buildings with a view to decarbonization, the quantitative reduction in the consumption of fossil fuels was investigated in all regions of Europe through the use of heat pumps. First, a general overview of energy consumption in buildings in Europe has been assessed. The consumption of buildings has been addressed to the different uses (heating, cooling, DHW, etc.) as well as the different sources (natural gas, oil, biomass, etc.). The analysis has been done in order to provide a baseline at the European level on the current consumptions and future consumptions, with a particular interest in the future increase of cooling. A database was therefore created on the distribution of residential energy consumption linked to air conditioning among the various energy carriers (electricity, waste heat, gas, solid fossil fuels, liquid fossil fuels, and renewable sources) for each region in Europe. Subsequently, the energy profiles of various European cities representative of the different climates are analyzed in order to evaluate, in each European climatic region, which energy coverage can be provided by heat pumps in replacement of natural gas and solid and liquid fossil fuels for air conditioning of the buildings, also carrying out the environmental and economic assessments for this energy transition operation. This work aims to make an innovative contribution to the evaluation of the potential for introducing heat pump technology for decarbonization in the air conditioning of buildings in all climates of the different European regions.

Keywords: heat pumps, heating, decarbonization, energy policies

Procedia PDF Downloads 125
1995 Pain Management in Burn Wounds with Dual Drug Loaded Double Layered Nano-Fiber Based Dressing

Authors: Sharjeel Abid, Tanveer Hussain, Ahsan Nazir, Abdul Zahir, Nabyl Khenoussi

Abstract:

Localized application of drug has various advantages and fewer side effects as compared with other methods. Burn patients suffer from swear pain and the major aspects that are considered for burn victims include pain and infection management. Nano-fibers (NFs) loaded with drug, applied on local wound area, can solve these problems. Therefore, this study dealt with the fabrication of drug loaded NFs for better pain management. Two layers of NFs were fabricated with different drugs. Contact layer was loaded with Gabapentin (a nerve painkiller) and the second layer with acetaminophen. The fabricated dressing was characterized using scanning electron microscope, Fourier Transform Infrared Spectroscopy, X-Ray Diffraction and UV-Vis Spectroscopy. The double layered based NFs dressing was designed to have both initial burst release followed by slow release to cope with pain for two days. The fabricated nanofibers showed diameter < 300 nm. The liquid absorption capacity of the NFs was also checked to deal with the exudate. The fabricated double layered dressing with dual drug loading and release showed promising results that could be used for dealing pain in burn victims. It was observed that by the addition of drug, the size of nanofibers was reduced, on the other hand, the crystallinity %age was increased, and liquid absorption decreased. The combination of fast nerve pain killer release followed by slow release of non-steroidal anti-inflammatory drug could be a good tool to reduce pain in a more secure manner with fewer side effects.

Keywords: pain management, burn wounds, nano-fibers, controlled drug release

Procedia PDF Downloads 251
1994 Analytical Method Development and Validation of Stability Indicating Rp - Hplc Method for Detrmination of Atorvastatin and Methylcobalamine

Authors: Alkaben Patel

Abstract:

The proposed RP-HPLC method is easy, rapid, economical, precise and accurate stability indicating RP-HPLC method for simultaneous estimation of Astorvastatin and Methylcobalamine in their combined dosage form has been developed.The separation was achieved by LC-20 AT C18(250mm*4.6mm*2.6mm)Colum and water (pH 3.5): methanol 70:30 as mobile phase, at a flow rate of 1ml/min. wavelength of this dosage form is 215nm.The drug is related to stress condition of hydrolysis, oxidation, photolysis and thermal degradation.

Keywords: RP- HPLC, atorvastatin, methylcobalamine, method, development, validation

Procedia PDF Downloads 333
1993 Synthesis of Fullerene Nanorods for Detection of Ethylparaben an Endocrine Disruptor in Cosmetics

Authors: Jahangir Ahmad Rather, Emad A. Khudaish, Ahsanulhaq Qurashi, Palanisamy Kannan

Abstract:

Chemical modification and assembling of fullerenes are fundamentally important for the application of fullerenes as functional molecules and in molecular devices and organic electronic devices. We have synthesized fullerene nanorods C60NRs conjugate via liquid-liquid interface and the synthesized C60NRs was characterized by FTIR spectroscopy, field emission electron microscopy (FESEM) and X-ray diffraction techniques. The C60NRs were immobilized on glassy carbon electrode via surface bound diazonium salts as an impact strategy. This method involves electrografting of p–nitrophenyl to give GCE–Ph–NO2 and then the terminal nitro-group was chemically reduced to GCE–Ph–NH2 in a presence of sodium borohydride/gold–polyaniline nanocomposite (NaBH4/Au–PANI). The Au–PANI composite was synthesized and characterized by FTIR, UV-vis, SEM and EDX techniques. The C60NRs were immobilized on GCE–Ph–NH2 via amination reaction which involves N-H addition across a π-bond on [60] fullerene. The immobilized C60NRs/GCE was subjected to electrochemical reduction in 1.0 M KOH to yield ERC60NRs/GCE sensor. The developed sensor shows high electrocatalytic activity for the detection of ethylparaben (EP) over a concentration range from 0.01 to 0.52 µM with a detection limit (LOD) 3.8 nM. The amount of EP present in the nourishing repair cream (OlAY®) was determined by standard addition method at the developed ERC60NRs/GCE sensor. The total concentration of EP was found to be 0.011 µM (0.1%) and is within the permissible limit of 0.19 % EP in cosmetics according to the European scientific committee (SCCS) on consumer safety on 22 March 2011 (SCCS/1348/11).

Keywords: diazonium salt reduction, ethylparaben (EP), endocrine disruptor, fullerene nanorods (C60NRs), gold–polyaniline nanocomposite (Au–PANI)

Procedia PDF Downloads 232