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Sample records for thermo-gravimetric analysis tga

  1. Strategy for thermo-gravimetric analysis of K East fuel samples

    International Nuclear Information System (INIS)

    Lawrence, L.A.

    1997-01-01

    A strategy was developed for the Thermo-Gravimetric Analysis (TGA) testing of K East fuel samples for oxidation rate determinations. Tests will first establish if there are any differences for dry air oxidation between the K West and K East fuel. These tests will be followed by moist inert gas oxidation rate measurements. The final series of tests will consider pure water vapor i.e., steam

  2. Thermal analysis of thermo-gravimetric measurements of spent nuclear fuel oxidation rates

    International Nuclear Information System (INIS)

    Cramer, E.R.

    1997-01-01

    A detailed thermal analysis was completed of the sample temperatures in the Thermo-Gravimetric Analysis (TGA) system used to measure irradiated N Reactor fuel oxidation rates. Sample temperatures during the oxidation process did not show the increase which was postulated as a result of the exothermic reactions. The analysis shows the axial conduction of heat in the sample holder effectively removes the added heat and only a very small, i.e., <10 C, increase in temperature is calculated. A room temperature evaporation test with water showed the sample thermocouple sensitivity to be more than adequate to account for a temperature change of approximately 5 C. Therefore, measured temperatures in the TGA are within approximately 10 C of the actual sample temperatures and no adjustments to reported data to account for the heat input from the oxidation process are necessary

  3. Thermo Gravimetric and Differential Thermal Analysis of Clay of Western Rajasthan (india)

    Science.gov (United States)

    Shekhawat, M. S.

    The paper presents the study of thermo gravimetric and differential thermal analysis of blended clay. Western part of Rajasthan (India) is rich resource of Ball clays and it is mainly used by porcelain, sanitary ware, and tile industry. The quality and grade of clay available in the region vary from one deposit to other. To upgrade the fired colour and strength properties, different variety of clays may be blended together. The paper compares the results of thermal analysis one of blended clay B2 with reference clay of Ukraine which is imported by industries owners. The result revealed that the blended clay is having mineral kaolinite while the Ukrainian clay is Halloysite.

  4. Understanding of thermo-gravimetric analysis to calculate number of addends in multifunctional hemi-ortho ester derivatives of fullerenol

    International Nuclear Information System (INIS)

    Singh, Rachana; Goswami, Thakohari

    2011-01-01

    Test results for the applicability of existing thermo-gravimetric analysis (TGA) technique to ascertain average number of exohedral chemical attachment in a new class of fullerene dyads consisting of multiple hemi-ortho esters onto fullerenol is presented. Although the method is nicely applicable for higher fullerenol, but homogeneous phase products calculate lower number of addends, whereas, the hetero phase products indicate higher value. Lower value is attributed to either overlapping of thermal events or substituents effects and higher value is the contribution of tetra butyl ammonium hydroxide (TBAH) impurity used as phase transfer catalyst (PTC) in heterogeneous phase reactions. Presence of TBAH impurity is recognized through thermo-gravimetry mass spectrometry (TG-MS) measurement. Appropriate modification of test method to arrive at accurate and precise values of x (total mass contribution due to addends only) and y (total mass contribution due to fullerene plus char yield) are also reported. Successful use of two more different techniques, viz., electron-spray ionization mass spectrometry (ESI-MS) and X-ray photoelectron spectroscopy (XPS), supplement above results. Influences of fullerene and different substituents on thermal behavior of dyads are assessed.

  5. Heavy fuel oil pyrolysis and combustion: kinetics and evolved gases investigated by TGA-FTIR

    KAUST Repository

    Abdul Jameel, Abdul Gani; Han, Yunqing; Brignoli, Omar; Telalovic, Selvedin; Elbaz, Ayman M.; Im, Hong G.; Roberts, William L.; Sarathy, Mani

    2017-01-01

    investigated using non-isothermal thermo-gravimetric analysis (TGA) coupled with a Fourier-transform infrared (FTIR) spectrometer. TG and DTG (differential thermo-gravimetry) were used for the kinetic analysis and to study the mass loss characteristics due

  6. Some critical aspects of FT-IR, TGA, powder XRD, EDAX and SEM studies of calcium oxalate urinary calculi.

    Science.gov (United States)

    Joshi, Vimal S; Vasant, Sonal R; Bhatt, J G; Joshi, Mihir J

    2014-06-01

    Urinary calculi constitute one of the oldest afflictions of humans as well as animals, which are occurring globally. The calculi vary in shape, size and composition, which influence their clinical course. They are usually of the mixed-type with varying percentages of the ingredients. In medical management of urinary calculi, either the nature of calculi is to be known or the exact composition of calculi is required. In the present study, two selected calculi were recovered after surgery from two different patients for detailed examination and investigated by using Fourier-Transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), powder X-ray diffraction (XRD), scanning electron microscopy and energy dispersive analysis of X-rays (EDAX) techniques. The study demonstrated that the nature of urinary calculi and presence of major phase in mixed calculi could be identified by FT-IR, TGA and powder XRD, however, the exact content of various elements could be found by EDAX only.

  7. Study of solid chemical evolution in torrefaction of different biomasses through solid-state "1"3C cross-polarization/magic angle spinning NMR (nuclear magnetic resonance) and TGA (thermogravimetric analysis)

    International Nuclear Information System (INIS)

    Rodriguez Alonso, Elvira; Dupont, Capucine; Heux, Laurent; Da Silva Perez, Denilson; Commandre, Jean-Michel; Gourdon, Christophe

    2016-01-01

    The objective of this work is to compare mass loss and chemical evolution of the solid phase, versus time, during dynamic torrefaction of different types of biomass. For this purpose, two experiments, ThermoGravimetric Analysis and solid-state "1"3C Cross-Polarization/Magic Angle Spinning Nuclear Magnetic Resonance, were run on four representative biomasses. Overall mass loss and chemical evolution of the solid phase were followed, respectively, as a function of temperature and time. Thanks to this coupled information, it was shown that the knowledge of both solid mass loss and chemical evolution is necessary to characterize torrefaction severity. Moreover, biomasses containing higher proportions of xylan lost mass faster than those containing lower proportions. Lignin showed a protecting role towards cellulose, which would lead to a faster degradation of non-woody biomasses in comparison with woody biomasses. Three parameters would have an influence on solid chemical evolution during torrefaction: xylan content in hemicellulose, lignin content in biomass, and cellulose crystallinity. - Highlights: • Torrefaction of four biomasses was studied with TGA and solid-state NMR. • Both solid mass loss and chemical evolution characterize torrefaction severity. • Biomasses containing a higher proportion of xylan lose mass faster. • Lignin shows a stronger protecting role in degradation of woody biomasses. • Xylan, lignin and crystalline cellulose values influence solid chemical evolution.

  8. Determination of oxygen to metal ratio for varying UO2 content in sintered (U,Th)O2 pellet by oxidation-reduction method using thermo-gravimetric analyser

    International Nuclear Information System (INIS)

    Mahanty, B.N.; Khan, F.A.; Karande, A.P.; Prakash, A.; Afzal, Md.; Panakkal, J.P.

    2009-01-01

    Experiments were carried out to determine oxygen to metal ratio in 4%, 6%, 10%, 20%, 50% and 80% UO 2 in sintered (U, Th) O 2 pellets by oxidation-reduction method using thermo gravimetric analyser. (author)

  9. Characterization of materials used in the execution of historic oil paintings by XRD, SEM-EDS, TGA and LIBS analysis

    OpenAIRE

    Şerifaki, Kerem; Böke, Hasan; Yalçın, Şerife; İpekoğlu, Başak

    2009-01-01

    In this study, material characteristics of historic oil paintings in a 19th century church in Ayvali{dotless}k/Turkey were investigated to propose the treatments to be used in their conservation and protection. For this purpose, physical, chemical and mineralogical compositions and the microstructure of the paintings were determined by X-ray Diffraction, Scanning Electron Microscope, Thermo Gravimetric Analyzer, Differential Scanning Calorimeter, Infrared Spectroscopy and Laser Induced Breakd...

  10. Quantitative detection of powdered activated carbon in wastewater treatment plant effluent by thermogravimetric analysis (TGA).

    Science.gov (United States)

    Krahnstöver, Therese; Plattner, Julia; Wintgens, Thomas

    2016-09-15

    For the elimination of potentially harmful micropollutants, powdered activated carbon (PAC) adsorption is applied in many wastewater treatment plants (WWTP). This holds the risk of PAC leakage into the WWTP effluent and desorption of contaminants into natural water bodies. In order to assess a potential PAC leakage, PAC concentrations below several mg/L have to be detected in the WWTP effluent. None of the methods that are used for water analysis today are able to differentiate between activated carbon and solid background matrix. Thus, a selective, quantitative and easily applicable method is still needed for the detection of PAC residues in wastewater. In the present study, a method was developed to quantitatively measure the PAC content in wastewater by using filtration and thermogravimetric analysis (TGA), which is a well-established technique for the distinction between different solid materials. For the sample filtration, quartz filters with a temperature stability up to 950 °C were used. This allowed for sensitive and well reproducible measurements, as the TGA was not affected by the presence of the filter. The sample's mass fractions were calculated by integrating the mass decrease rate obtained by TGA in specific, clearly identifiable peak areas. A two-step TGA heating method consisting of N2 and O2 atmospheres led to a good differentiation between PAC and biological background matrix, thanks to the reduction of peak overlapping. A linear correlation was found between a sample's PAC content and the corresponding peak areas under N2 and O2, the sample volume and the solid mass separated by filtration. Based on these findings, various wastewater samples from different WWTPs were then analyzed by TGA with regard to their PAC content. It was found that, compared to alternative techniques such as measurement of turbidity or total suspended solids, the newly developed TGA method allows for a quantitative and selective detection of PAC concentrations down to 0

  11. Pyrolysis kinetics investigation of Malaysian based biomass with non-isothermal thermogravimetric analysis (TGA)

    International Nuclear Information System (INIS)

    Seyed Shahabeddin Nehzati; Dayang Radiah Awang Biak; Wan Azlina Wan Abdul Karim Ghani; Mohd Amran Mohd Salleh

    2010-01-01

    Full text: Biomass is currently being used as a sustainable energy source. Otherwise the scarceness of fossil fuel sources and the demand for environmental responsibility force the industries to use biomass as an alternate source of energy. Pyrolysis is the first step of biomass conversion and well understanding of this process can develop the biomass conversion such as gasification, liquefaction, carbonization and combustion .TGA studies of Malaysian based biomass have been carried out. TGA studies provide important insight on the thermochemical behavior of specific solid waste. The results of non-isothermal thermogravimetric analysis of palm kernel shell, coconut shell and bagasse, carried out at heating rates of 10 degree Celsius/ min, 20 degree Celsius/ min and 50 degree Celsius/ min, to ramp the temperature from 30 to 1000 were analysed. The TGA studies were carried out in an inert atmosphere of nitrogen. Arrhenius parameters were estimated by 3 different models namely Kissinger model, three-pseudo component and DEAM model the estimated values and the models were compared. The results show that the three-pseudo component model has a good agreement with the experimental results, indicating that ligno celluloses components in the mixture behave in the same way as they do separately. Also it is seen that the decomposition process shifts to higher temperatures at higher heating rates as a result of the competing effects of heat and mass transfer to the material. (Author)

  12. Qualitative and kinetic analysis of torrefaction of lignocellulosic biomass using DSC-TGA-FTIR

    Directory of Open Access Journals (Sweden)

    Bimal Acharya

    2015-11-01

    Full Text Available Torrefaction is a thermochemical conversion technique to improve the fuel properties of lignocellulosic biomass by treating at temperature 200 ℃-300 ℃ in the minimum oxygen environment for a reasonable residence time. In this study, thermal decomposition and thermal activities of miscanthus and wheat straw during the torrefaction at 200 ℃, 275 ℃, and 300 ℃ in a nitrogen environment for 45 minutes of residence time are analyzed in a simultaneous thermogravimetric analyzer (micro TGA with a differential scanning calorimetry (DSC, and a macro-TGA. The output of the micro TGA is fed into the Fourier transform infrared spectrometry (FTIR and qualitative analysis of the gaseous product is carried out. The composition of different gas products during the torrefaction of biomass are compared critically and kinetics were analyzed. It is found that the weight loss due to degradation of initial biomass in second stage (torrefaction process is a much faster conversion process than the weight loss process in the first stage (drying process. The weight loss of biomass increases with increase in the residence time and torrefaction treatment temperatures. The yield after torrefaction is a solid bio-coal product. The torrefied product were less reactive and has nearly 25% better heating value than the raw biomass. Between the two feedstocks studied, torrefied miscanthus proved to be a more stable fuel than the torrefied wheat straw. The major gaseous components observed during torrefaction are water, carbon dioxide, carbon monoxide, 1,2-Dibromethylene.

  13. Heavy fuel oil pyrolysis and combustion: kinetics and evolved gases investigated by TGA-FTIR

    KAUST Repository

    Abdul Jameel, Abdul Gani

    2017-08-24

    Heavy fuel oil (HFO) obtained from crude oil distillation is a widely used fuel in marine engines and power generation technologies. In the present study, the pyrolysis and combustion of a Saudi Arabian HFO in nitrogen and in air, respectively, were investigated using non-isothermal thermo-gravimetric analysis (TGA) coupled with a Fourier-transform infrared (FTIR) spectrometer. TG and DTG (differential thermo-gravimetry) were used for the kinetic analysis and to study the mass loss characteristics due to the thermal degradation of HFO at temperatures up to 1000°C and at various heating rates of 5, 10 and 20°C/min, in air and N2 atmospheres. FTIR analysis was then performed to study the composition of the evolved gases. The TG/DTG curves during HFO combustion show the presence of three distinct stages: the low temperature oxidation (LTO); fuel decomposition (FD); and high temperature oxidation (HTO) stages. The TG/DTG curves obtained during HFO pyrolysis show the presence of two devolatilization stages similar to that seen in the LTO stage of HFO combustion. Apart from this, the TG/DTG curves obtained during HFO combustion and pyrolysis differ significantly. Kinetic analysis was also performed using the distributed activation energy model, and the kinetic parameter (E) was determined for the different stages of HFO combustion and pyrolysis processes, yielding a good agreement with the measured TG profiles. FTIR analysis showed the signal of CO2 as approximately 50 times more compared to the other pollutant gases under combustion conditions. Under pyrolytic conditions, the signal intensity of alkane functional groups was the highest followed by alkenes. The TGA-FTIR results provide new insights into the overall HFO combustion processes, which can be used to improve combustor designs and control emissions.

  14. Magneto-thermo-gravimetric technique to investigate the structural and magnetic properties of Fe-B-Nb-Y Bulk Metallic Glass

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangmin; Makino, Akihiro; Inoue, Akihisa [Department of Materials Science, Graduate School of Engineering, Tohoku University, Sendai 980-8579 (Japan); Masood, Ansar; Tamaki, Takahiko; Valter, Strom; Rao, K V, E-mail: smlee@imr.tohoku.ac.j [Royal Institute of Technology (KTH), SE-100 44 Stockhom (Sweden)

    2009-01-01

    Magneto-thermo-gravimetric (MTG) technique is highly informative about the changes in the magnetic state, as well as structural changes in a system, which cannot be often noticed in calorimetric measurements. We demonstrate the versatility of this technique in determining the magnetic transition temperature, and the subsequent crystallization process in a (Fe{sub 0.72}B{sub 0.24}Nb{sub 0.04}){sub 95.5}Y{sub 4.5} Bulk Metallic Glass (BMG). MTG and DSC analyses were carried out at the heating rate of 0.67 K/s from RT {approx}1170 K. As a result of the repeated MTG measurements, a magnetic 2nd amorphous phase was observed in the BMG sample, which could be the first measurement for the Magnetic Short Range Ordering (MSRO). Consequently, the MTG measurement is proved as the most convenient method for determining the various structural and magnetic transitions in a glassy material.

  15. Thermogravimetric Analysis (TGA) Profile of Modified Sba-15 at Different Amount of Alkoxy silane Group

    International Nuclear Information System (INIS)

    Norhasyimi Rahmat; Nur Fathilah Mohd Yusof; Ezani Hafiza

    2014-01-01

    This study focused on meso porous silica SBA-15 modified with alkoxy silane functional group; phenyltriethoxysilane (PTES) and vinyltriethoxysilane (VTES) using direct synthesis and post-grafting methods. By direct synthesis method, SBA-15 template by triblock copolymer (P123) and functionalized with alkoxy silane groups at different amount of loadings were co-condensed with tetraethyl orthosilicate (TEOS) under acidic conditions. As for post-grafting method, different loadings of alkoxy silane groups were added after co-condensation of TEOS with P123 template. Both synthesis methods used calcination process to remove surfactant template at 550 degree Celsius for 5 hours. The derivatized SBA-15 was characterized by thermogravimetric analysis to evaluate the profile at different loadings of alkoxy silane groups with different synthesis method. At temperature range of 300-800 degree Celsius, post-grafting method displayed the highest weight loss of phenyl and vinyl groups. However, there was no significant difference of weight loss for different amount of organo silane groups. In this study, TGA has shown to be significant characterization means to determine the effects of different method used in synthesizing modified SBA-15. It was shown that different loading of phenyl and vinyl groups did not affect the efficiency of surfactant removal. (author)

  16. A thermogravimetric analysis (TGA) method to determine the catalytic conversion of cellulose from carbon-supported hydrogenolysis process

    International Nuclear Information System (INIS)

    Leal, Glauco F.; Ramos, Luiz A.; Barrett, Dean H.; Curvelo, Antonio Aprígio S.; Rodella, Cristiane B.

    2015-01-01

    Graphical abstract: - Highlights: • A new method to determine the catalytic conversion of cellulose using TGA has been developed. • TGA is able to differentiate between carbon from cellulose and carbon from the catalyst. • Building an analytical curve from TGA results enables the accurate determination of cellulose conversion. - Abstract: The ability to determine the quantity of solid reactant that has been transformed after a catalytic reaction is fundamental in accurately defining the conversion of the catalyst. This quantity is also central when investigating the recyclability of a solid catalyst as well as process control in an industrial catalytic application. However, when using carbon-supported catalysts for the conversion of cellulose this value is difficult to obtain using only a gravimetric method. The difficulty lies in weighing errors caused by loss of the solid mixture (catalyst and non-converted cellulose) after the reaction and/or moisture adsorption by the substrate. These errors are then propagated into the conversion calculation giving erroneous results. Thus, a quantitative method using thermogravimetric analysis (TGA) has been developed to determine the quantity of cellulose after a catalytic reaction by using a tungsten carbide catalyst supported on activated carbon. Stepped separation of TGA curves was used for quantitative analysis where three thermal events were identified: moisture loss, cellulose decomposition and CO/CO 2 formation. An analytical curve was derived and applied to quantify the residual cellulose after catalytic reactions which were performed at various temperatures and reaction times. The catalytic conversion was calculated and compared to the standard gravimetric method. Results showed that catalytic cellulose conversion can be determined using TGA and exhibits lower uncertainty (±2%) when compared to gravimetric determination (±5%). Therefore, it is a simple and relatively inexpensive method to determine catalytic

  17. Thermal analysis on parchments I: DSC and TGA combined approach for heat damage assessment

    DEFF Research Database (Denmark)

    Fessas, D.; Signorelli, M.; Schiraldi, A.

    2006-01-01

    Ancient, new and artificially aged parchments were investigated with both differential scanning calorimetry (DSC) and thermogravimetry (TGA). Criteria to define a quantitative ranking of the damage experienced by the bulk collagen of historical parchments were assessed. A damage-related correlation...

  18. Thermal decomposition of dolomite under CO2: insights from TGA and in situ XRD analysis.

    Science.gov (United States)

    Valverde, Jose Manuel; Perejon, Antonio; Medina, Santiago; Perez-Maqueda, Luis A

    2015-11-28

    Thermal decomposition of dolomite in the presence of CO2 in a calcination environment is investigated by means of in situ X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The in situ XRD results suggest that dolomite decomposes directly at a temperature around 700 °C into MgO and CaO. Immediate carbonation of nascent CaO crystals leads to the formation of calcite as an intermediate product of decomposition. Subsequently, decarbonation of this poorly crystalline calcite occurs when the reaction is thermodynamically favorable and sufficiently fast at a temperature depending on the CO2 partial pressure in the calcination atmosphere. Decarbonation of this dolomitic calcite occurs at a lower temperature than limestone decarbonation due to the relatively low crystallinity of the former. Full decomposition of dolomite leads also to a relatively low crystalline CaO, which exhibits a high reactivity as compared to limestone derived CaO. Under CO2 capture conditions in the Calcium-Looping (CaL) process, MgO grains remain inert yet favor the carbonation reactivity of dolomitic CaO especially in the solid-state diffusion controlled phase. The fundamental mechanism that drives the crystallographic transformation of dolomite in the presence of CO2 is thus responsible for its fast calcination kinetics and the high carbonation reactivity of dolomitic CaO, which makes natural dolomite a potentially advantageous alternative to limestone for CO2 capture in the CaL technology as well as SO2in situ removal in oxy-combustion fluidized bed reactors.

  19. Analysis of the effects of biomass on the co-pyrolysis of coal using TGA method

    International Nuclear Information System (INIS)

    Yaman, S.; Haykiri-Acma, H.

    2009-01-01

    Turkey is a developing country with a population of 7.15 million and its economy is the 16th biggest in the world and 7th biggest in Europe (after Germany, United Kingdom, France, Italy, Spain, and Russia) with a Gross Domestic Product (GDP) of about 700 billion dollar. Low quality lignitic coals are the most significant primary energy resources of Turkey. Consequently, production of lignite in 2007 is 72 million tons, representing about 7.5% of lignite consumption of the world. However, undesirable characteristics of these lignites such as low calorific value, high ash, and high sulfur are some of serious drawbacks in the usage of them in conventional burning systems, regarding problematic deposit formations and polluting emissions. Therefore, alternative processes for these lignites such as pyrolysis and gasification to produce fuel gases and chemical are preferable. In this study, co-pyrolysis characteristics of Afsin-Elbistan lignite with biomass species such as hazelnut shells, sunflower seed shells, and hybrid poplar were investigated by Non-isothermal Thermogravimetry (TGA) technique. Structural differences in the physical and chemical properties of the samples were studied applying some methods such as X-Ray Diffractometry and Scanning Electron Microscopy. This study showed that addition of such biomass materials into lignite and then co-pyrolysis of these mixtures led to conversion levels that are seriously higher than the conversion level of the lignite alone under the same pyrolytic conditions. It is concluded that there are evident differences between the thermal reactivities of the lignite and the biomass materials, and the increase in the thermal reactivity when biomass was introduced may be explained by synergistic interactions between the constituents of lignite and biomass. (author)

  20. Pyrolysis characteristics and kinetic parameters determination of biomass fuel powders by differential thermal gravimetric analysis (TGA/DTG)

    International Nuclear Information System (INIS)

    El-Sayed, Saad A.; Mostafa, M.E.

    2014-01-01

    Highlights: • The sugarcane bagasse powder has better energy value compared to the cotton stalks. • Bagasse moisture is entrained in its cell walls and its evaporation needs more energy. • The cotton stalks is more reactive and readily combustible than the bagasse powders. • A lower E and A 0 has been found for bagasse compared with cotton stalks powders. • Calculated E of bagasse and cotton stalks by direct and integral methods are different. - Abstract: The kinetics of the thermal decomposition of the two biomass materials (sugarcane bagasse and cotton stalks powders) were evaluated using a differential thermo-gravimetric analyzer under a non-isothermal condition. Two distinct reaction zones were observed for the two biomasses. The direct Arrhenius plot method and the integral method were applied for determination of kinetic parameters: activation energy, pre-exponential factor, and order of reaction. The weight loss curve showed that pyrolysis of sugarcane bagasse and cotton stalks took place mainly in the range of 200–500 °C. The activation energy of the sugarcane bagasse powder obtained by the direct Arrhenius plot method ranged between 43 and 53.5 kJ/mol. On the other side, the integral method shows larger values of activation energy (77–87.7 kJ/mol). The activation energy of the cotton stalks powder obtained by the direct Arrhenius plot method was ranged between 98.5 and 100.2 kJ/mol, but the integral method shows larger values of activation energy (72.5–127.8 kJ/mol)

  1. Analysis of glass fibre sizing

    DEFF Research Database (Denmark)

    Petersen, Helga Nørgaard; Kusano, Yukihiro; Brøndsted, Povl

    2014-01-01

    Glass fibre reinforced polymer composites are widely used for industrial and engineering applications which include construction, aerospace, automotive and wind energy industry. During the manufacturing glass fibres, they are surface-treated with an aqueous solution. This process and the treated...... surfaces are called sizing. The sizing influences the properties of the interface between fibres and a matrix, and subsequently affects mechanical properties of composites. In this work the sizing of commercially available glass fibres was analysed so as to study the composition and chemical structures....... Soxhlet extraction was used to extract components of the sizing from the glass fibres. The glass fibres, their extracts and coated glass plates were analysed by Thermo-Gravimetric Analysis combined with a mass spectrometer (TGA-MS), and Attenuated Total Reflectance Fourier Transform Infrared (ATR...

  2. Pyrolysis characteristics and kinetics of microalgae via thermogravimetric analysis (TGA): A state-of-the-art review.

    Science.gov (United States)

    Bach, Quang-Vu; Chen, Wei-Hsin

    2017-12-01

    Pyrolysis is a promising route for biofuels production from microalgae at moderate temperatures (400-600°C) in an inert atmosphere. Depending on the operating conditions, pyrolysis can produce biochar and/or bio-oil. In practice, knowledge for thermal decomposition characteristics and kinetics of microalgae during pyrolysis is essential for pyrolyzer design and pyrolysis optimization. Recently, the pyrolysis kinetics of microalgae has become a crucial topic and received increasing interest from researchers. Thermogravimetric analysis (TGA) has been employed as a proven technique for studying microalgae pyrolysis in a kinetic control regime. In addition, a number of kinetic models have been applied to process the TGA data for kinetic evaluation and parameters estimation. This paper aims to provide a state-of-the art review on recent research activities in pyrolysis characteristics and kinetics of various microalgae. Common kinetic models predicting the thermal degradation of microalgae are examined and their pros and cons are illustrated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Combustion characteristics of Malaysian oil palm biomass, sub-bituminous coal and their respective blends via thermogravimetric analysis (TGA).

    Science.gov (United States)

    Idris, Siti Shawalliah; Rahman, Norazah Abd; Ismail, Khudzir

    2012-11-01

    The combustion characteristics of Malaysia oil palm biomass (palm kernel shell (PKS), palm mesocarp fibre (PMF) and empty fruit bunches (EFB)), sub-bituminous coal (Mukah Balingian) and coal/biomass blends via thermogravimetric analysis (TGA) were investigated. Six weight ratios of coal/biomass blends were prepared and oxidised under dynamic conditions from temperature 25 to 1100°C at four heating rates. The thermogravimetric analysis demonstrated that the EFB and PKS evolved additional peak besides drying, devolatilisation and char oxidation steps during combustion. Ignition and burn out temperatures of blends were improved in comparison to coal. No interactions were observed between the coal and biomass during combustion. The apparent activation energy during this process was evaluated using iso-conversional model free kinetics which resulted in highest activation energy during combustion of PKS followed by PMF, EFB and MB coal. Blending oil palm biomass with coal reduces the apparent activation energy value. Copyright © 2012 Elsevier Ltd. All rights reserved.

  4. Kinetics and evolved gas analysis for pyrolysis of food processing wastes using TGA/MS/FT-IR.

    Science.gov (United States)

    Özsin, Gamzenur; Pütün, Ayşe Eren

    2017-06-01

    The objective of this study was to identify the pyrolysis of different bio-waste produced by food processing industry in a comprehensible manner. For this purpose, pyrolysis behaviors of chestnut shells (CNS), cherry stones (CS) and grape seeds (GS) were investigated by thermogravimetric analysis (TGA) combined with a Fourier-transform infrared (FT-IR) spectrometer and a mass spectrometer (MS). In order to make available theoretical groundwork for biomass pyrolysis, activation energies were calculated with the help of four different model-free kinetic methods. The results are attributed to the complex reaction schemes which imply parallel, competitive and complex reactions during pyrolysis. During pyrolysis, the evolution of volatiles was also characterized by FT-IR and MS. The main evolved gases were determined as H 2 O, CO 2 and hydrocarbons such as CH 4 and temperature dependent profiles of the species were obtained. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Technical basis for the reduction of the maximum temperature TGA-MS analysis of oxide samples from the 3013 destructive examination program

    International Nuclear Information System (INIS)

    Scogin, J. H.

    2016-01-01

    Thermogravimetric analysis with mass spectroscopy of the evolved gas (TGA-MS) is used to quantify the moisture content of materials in the 3013 destructive examination (3013 DE) surveillance program. Salts frequently present in the 3013 DE materials volatilize in the TGA and condense in the gas lines just outside the TGA furnace. The buildup of condensate can restrict the flow of purge gas and affect both the TGA operations and the mass spectrometer calibration. Removal of the condensed salts requires frequent maintenance and subsequent calibration runs to keep the moisture measurements by mass spectroscopy within acceptable limits, creating delays in processing samples. In this report, the feasibility of determining the total moisture from TGA-MS measurements at a lower temperature is investigated. A temperature of the TGA-MS analysis which reduces the complications caused by the condensation of volatile materials is determined. Analysis shows that an excellent prediction of the presently measured total moisture value can be made using only the data generated up to 700 °C and there is a sound physical basis for this estimate. It is recommended that the maximum temperature of the TGA-MS determination of total moisture for the 3013 DE program be reduced from 1000 °C to 700 °C. It is also suggested that cumulative moisture measurements at 550 °C and 700°C be substituted for the measured value of total moisture in the 3013 DE database. Using these raw values, any of predictions of the total moisture discussed in this report can be made.

  6. Technical basis for the reduction of the maximum temperature TGA-MS analysis of oxide samples from the 3013 destructive examination program

    Energy Technology Data Exchange (ETDEWEB)

    Scogin, J. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-24

    Thermogravimetric analysis with mass spectroscopy of the evolved gas (TGA-MS) is used to quantify the moisture content of materials in the 3013 destructive examination (3013 DE) surveillance program. Salts frequently present in the 3013 DE materials volatilize in the TGA and condense in the gas lines just outside the TGA furnace. The buildup of condensate can restrict the flow of purge gas and affect both the TGA operations and the mass spectrometer calibration. Removal of the condensed salts requires frequent maintenance and subsequent calibration runs to keep the moisture measurements by mass spectroscopy within acceptable limits, creating delays in processing samples. In this report, the feasibility of determining the total moisture from TGA-MS measurements at a lower temperature is investigated. A temperature of the TGA-MS analysis which reduces the complications caused by the condensation of volatile materials is determined. Analysis shows that an excellent prediction of the presently measured total moisture value can be made using only the data generated up to 700 °C and there is a sound physical basis for this estimate. It is recommended that the maximum temperature of the TGA-MS determination of total moisture for the 3013 DE program be reduced from 1000 °C to 700 °C. It is also suggested that cumulative moisture measurements at 550 °C and 700°C be substituted for the measured value of total moisture in the 3013 DE database. Using these raw values, any of predictions of the total moisture discussed in this report can be made.

  7. Thermal degradation of Shredded Oil Palm Empty Fruit Bunches (SOPEFB) embedded with Cobalt catalyst by Thermogravimetric Analysis (TGA)

    Science.gov (United States)

    Alias, R.; Hamid, N. H.; Jaapar, J.; Musa, M.; Alwi, H.; Halim, K. H. Ku

    2018-03-01

    Thermal behavior and decomposition kinetics of shredded oil palm empty fruit bunches (SOPEFB) were investigated in this study by using thermogravimetric analysis (TGA). The SOPEFB were analyzed under conditions of temperature 30 °C to 900 °C with nitrogen gas flow at 50 ml/min. The SOPEFB were embedded with cobalt (II) nitrate solution with concentration 5%, 10%, 15% and 20%. The TG/DTG curves shows the degradation behavior of SOPEFB following with char production for each heating rate and each concentration of cobalt catalyst. Thermal degradation occurred in three phases, water drying phase, decomposition of hemicellulose and cellulose phase, and lignin decomposition phase. The kinetic equation with relevant parameters described the activation energy required for thermal degradation at the temperature regions of 200 °C to 350 °C. Activation energy (E) for different heating rate with SOPEFB embedded with different concentration of cobalt catalyst showing that the lowest E required was at SOPEFB with 20% concentration of cobalt catalyst..

  8. Measurement of Gd content in (U,Gd)O2 using thermal gravimetric analysis

    International Nuclear Information System (INIS)

    Kim, Keon Sik; Yang, Jae Ho; Kang, Ki Won; Song, Kun Woo; Kim, Gil Moo

    2004-01-01

    We propose a simple and precise method for measuring the Gd content in the (U,Gd)O 2 pellet by only measuring the weight variation of the pellet during thermal heat treatment in air. The (U,Gd)O 2 fuel pellets were oxidized at 475 deg. C, subsequently heat treated at 1300 deg. C, and then cooled to room temperature in air. The accompanying weight variations were measured using thermo gravimetric analysis (TGA). The measured weight variations were mathematically analyzed with reference to the successive phase reactions during the heat treatment. This method provides an advantage in that the rare-earth element content including Gd can be measured using relatively simple equipment such as an electric furnace and a balance

  9. A thermogravimetric analysis (TGA) method developed for estimating the stoichiometric ratio of solid-state {alpha}-cyclodextrin-based inclusion complexes

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yuxiang; Wang, Jinpeng; Bashari, Mohanad; Hu, Xiuting [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Feng, Tao [School of Perfume and Aroma Technology, Shanghai Institute of Technology, Shanghai 201418 (China); Xu, Xueming [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Jin, Zhengyu, E-mail: jinlab2008@yahoo.com [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China); Tian, Yaoqi, E-mail: yqtian@jiangnan.edu.cn [The State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122 (China)

    2012-08-10

    Highlights: Black-Right-Pointing-Pointer We develop a TGA method for the measurement of the stoichiometric ratio. Black-Right-Pointing-Pointer A series of formulas are deduced to calculate the stoichiometric ratio. Black-Right-Pointing-Pointer Four {alpha}-CD-based inclusion complexes were successfully prepared. Black-Right-Pointing-Pointer The developed method is applicable. - Abstract: An approach mainly based on thermogravimetric analysis (TGA) was developed to evaluate the stoichiometric ratio (SR, guest to host) of the guest-{alpha}-cyclodextrin (Guest-{alpha}-CD) inclusion complexes (4-cresol-{alpha}-CD, benzyl alcohol-{alpha}-CD, ferrocene-{alpha}-CD and decanoic acid-{alpha}-CD). The present data obtained from Fourier transform-infrared (FT-IR) spectroscopy showed that all the {alpha}-CD-based inclusion complexes were successfully prepared in a solid-state form. The stoichiometric ratios of {alpha}-CD to the relative guests (4-cresol, benzyl alcohol, ferrocene and decanoic acid) determined by the developed method were 1:1, 1:2, 2:1 and 1:2, respectively. These SR data were well demonstrated by the previously reported X-ray diffraction (XRD) method and the NMR confirmatory experiments, except the SR of decanoic acid with a larger size and longer chain was not consistent. It is, therefore, suggested that the TGA-based method is applicable to follow the stoichiometric ratio of the polycrystalline {alpha}-CD-based inclusion complexes with smaller and shorter chain guests.

  10. A thermogravimetric analysis (TGA) method developed for estimating the stoichiometric ratio of solid-state α-cyclodextrin-based inclusion complexes

    International Nuclear Information System (INIS)

    Bai, Yuxiang; Wang, Jinpeng; Bashari, Mohanad; Hu, Xiuting; Feng, Tao; Xu, Xueming; Jin, Zhengyu; Tian, Yaoqi

    2012-01-01

    Highlights: ► We develop a TGA method for the measurement of the stoichiometric ratio. ► A series of formulas are deduced to calculate the stoichiometric ratio. ► Four α-CD-based inclusion complexes were successfully prepared. ► The developed method is applicable. - Abstract: An approach mainly based on thermogravimetric analysis (TGA) was developed to evaluate the stoichiometric ratio (SR, guest to host) of the guest–α-cyclodextrin (Guest-α-CD) inclusion complexes (4-cresol-α-CD, benzyl alcohol-α-CD, ferrocene-α-CD and decanoic acid-α-CD). The present data obtained from Fourier transform-infrared (FT-IR) spectroscopy showed that all the α-CD-based inclusion complexes were successfully prepared in a solid-state form. The stoichiometric ratios of α-CD to the relative guests (4-cresol, benzyl alcohol, ferrocene and decanoic acid) determined by the developed method were 1:1, 1:2, 2:1 and 1:2, respectively. These SR data were well demonstrated by the previously reported X-ray diffraction (XRD) method and the NMR confirmatory experiments, except the SR of decanoic acid with a larger size and longer chain was not consistent. It is, therefore, suggested that the TGA-based method is applicable to follow the stoichiometric ratio of the polycrystalline α-CD-based inclusion complexes with smaller and shorter chain guests.

  11. Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez, Carmen P.; Pierce, David A.; Schweiger, Michael J.; Kruger, Albert A.; Chun, Jaehun; Hrma, Pavel R.

    2013-12-03

    For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent mass loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.

  12. Development of microbial resistant Carbopol nanocomposite hydrogels via a green process

    CSIR Research Space (South Africa)

    Varaprasad, K

    2014-01-01

    Full Text Available transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA), scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and transmission electron microscopy (TEM). The pure and inorganic nanocomposite hydrogels developed were tested...

  13. DABCO CONTAINING ACIDIC POLY(IONIC LIQUID): AN EFFICIENT ...

    African Journals Online (AJOL)

    3Department of Medicinal Chemistry, School of Pharmacy, Ardabil University of Medical. Sciences, Ardabil, Iran ... Two basic strategies have been utilized for PILs synthesis, 1) direct .... The thermo gravimetric analysis (TGA) of the catalyst was.

  14. DNA Based Electrolyte/Separator for Lithium Battery Application (Postprint)

    Science.gov (United States)

    2015-10-07

    composite electrolyte as shown by the thermos- gravimetric analysis (TGA). The AC conductivity measurements suggest that the addition of DC to the gel...stability of the composite electrolyte as shown by the thermos- gravimetric analysis (TGA). The AC conductivity measurements suggest that the...2.3. Testing methods and equipment Impedance testing using the Solartron 1260A Impedance/ Gain- phase Analyzer was performed on each cell at

  15. Thermal study of sintered (Th-U)O2 MOX pellet by a commercial thermo-gravimetric analyzer coupled with an evolved gas analyzer

    International Nuclear Information System (INIS)

    Mahanty, B.N.; Khan, F.A.; Karande, A.; Prakash, A.; Afzal, Md.; Panakkal, J.P.; Kamath, H.S.

    2010-01-01

    Full text: Fabrication of (Th-U)O 2 MOX pellets by the impregnation agglomerate pelletization (lAP) process is being explored in Advanced Fuel Fabrication Facility, BARC, Tarapur for the forthcoming Advanced Heavy Water Reactor (AHWR). High temperature thermal study of this fuel is important in order to understand the behaviour of the fuel under the operational temperature of the reactor. In this study, fabrication of ThO 2 -3%UO 2 was carried out by impregnation agglomerate pelletization process and subsequently sintered in reducing or air atmosphere. The degassed pellets were broken into small pieces and subjected to high temperature (1050 deg C-1250 deg C) heating under high pure argon gas in a commercial thermal analyzer. Subsequently the evolved gases were qualitatively analyzed by a quadrupole mass analyzer. The pellet sintered in reducing atmosphere (IAP-R) shows an increase in weight after the analysis where as the pellet sintered in oxidizing atmosphere (IAP-O) shows a decrease in final weight. The IAP-R pellet may become slightly hyper-stoichiometric on heating due to the presence of small amount of oxygen in the high pure argon gas. This is further supported by the mass spectrum at m/z 32(O 2 + ) that shows a decrease in the signal intensity as the temperature of analysis increases. The sharp decrease of the signal intensity at m/z 32(O 2 + ) started at 920 deg C temperature may be attributed to the formation of SO 2 (m/z=64) and CO 2 (m/z=44) gases. On the other hand the IAP-O pellet being hyper stoichiometric initially may lose its weight to form water on reaction with the excess oxygen on heating due to the presence ( small amount of hydrogen in the high pure argon gas. This is being supported by the appearance of small peak at m/z 18 (H 2 O + ) in the mass spectrum. The formation of SO 2 and CO 2 gases started at higher temperature in case of IAP-O pellet as compared to that of IAP-R pellet. This may be due to the higher density achieved in case of

  16. Mutational analysis of the PITX2 coding region revealed no common cause for transposition of the great arteries (dTGA

    Directory of Open Access Journals (Sweden)

    Goldmuntz Elizabeth

    2005-05-01

    Full Text Available Abstract Background PITX2 is a bicoid-related homeodomain transcription factor that plays an important role in asymmetric cardiogenesis. Loss of function experiments in mice cause severe heart malformations, including transposition of the great arteries (TGA. TGA accounts for 5–7% of all congenital heart diseases affecting 0.2 per 1000 live births, thereby representing the most frequent cyanotic heart defect diagnosed in the neonatal period. Methods To address whether altered PITX2 function could also contribute to the formation of dTGA in humans, we screened 96 patients with dTGA by means of dHPLC and direct sequencing for mutations within the PITX2 gene. Results Several SNPs could be detected, but no stop or frame shift mutation. In particular, we found seven intronic and UTR variants, two silent mutations and two polymorphisms within the coding region. Conclusion As most sequence variants were also found in controls we conclude that mutations in PITX2 are not a common cause of dTGA.

  17. Assessment of the surface chemistry of carbon blacks by TGA-MS, XPS and inverse gas chromatography using statistical chemometric analysis

    International Nuclear Information System (INIS)

    Strzemiecka, Beata; Voelkel, Adam; Donate-Robles, Jessica; Martín-Martínez, José Miguel

    2014-01-01

    Highlights: • Carbon blacks with lower specific surface area had basic character (electron donor) due to C=O and C-O groups. • Carbon blacks with higher specific surface area had acidic character (acceptor electron) due to OH groups. • Total surface energy and its dispersive component of carbon blacks increased by increasing their specific surface area. (table) - Abstract: Four carbon blacks with different specific surface areas and surface chemistries (C32, C71, C159 and C178) were analyzed by transmission electron microscopy (TEM) and nitrogen adsorption isotherms at 77 K. Their surface chemistries were analyzed by X-ray photoelectron spectroscopy (XPS), thermal gravimetric analysis coupled with mass spectrometry (TGA-MS) and inverse gas chromatography (IGC). The carbon blacks contained 2.7–5.8 wt% volatiles corresponding to -OH, C-O, C=O and COO groups. The surface chemistry parameters obtained with the different experimental techniques were inter-related by using chemometric statistical analysis tools. The application of this methodology showed that the carbon blacks with lower specific surface area (C32 and C71) had basic character (electron donor) mainly due to C=O and C-O groups, whereas the carbon black with the highest specific surface area (C178) showed acidic character (acceptor electron) due to its high content of OH groups. Moreover, the total surface energy and the dispersive component of the surface energy of the carbon blacks increased with the increase of their specific surface area. In general the specific interactions of the carbon blacks also increased with the increase of their specific surface area although C71 is exceptional due to higher oxygen content corresponding to C-O groups

  18. Detection of Certain Spices Subjected to Gamma Irradiation By Using Thermal Analysis Technique

    International Nuclear Information System (INIS)

    Sayed, M.S.; Ali, H.G.M.; Abdeldaiem, M.H.

    2013-01-01

    The present investigation was carried out to apply a detection method of some irradiated spices using thermal analysis technique. Black pepper, cumin and ginger were irradiated using gamma irradiation at dose levels 5, 10 and 15 kGy and stored for 12 months at room temperature. Thermal analysis techniques TGA and DTA were studied for characterizing irradiated spices. Thermo gravimetric analysis (TGA) is a method where the measurement of mass as a function of heating is recorded. TGA was used to determine the moisture and ash contents and thermal stabilities. Non-significant changes of the weight loss percent due to the irradiation were occurred on the studied spices up to 10 kGy. The weight loss was decreased at the first step up to 100 degree C due to the release of water of hydration. Another sharp decreasing in weight loss percent at the second step 220-300 degree C may be due to volatilization of the sample. The final weight loss weight loss stage up to 500 degree C may be due to burn out the fixed carbon remaining in the sample. As the irradiation dose increased from control up to 15 kGy, the weight loss percent at the dehydration step was decreased. The kinetics of the spices decomposition were studied in order to ascertain the type of weight loss mechanism and calculate the activation energy (E a ). The differential thermal analysis (DTA) of the studied samples showed two main characteristic peaks; endothermic one due to the dehydration process and the second peak may be due to the partial volatilization of the aromatic compounds of the main constituent of the studied spices. It could be concluded that using gamma irradiation (up to 15.0 kGy) for black pepper, cumin and ginger are thermally stable to human consumption.

  19. Thermogravimetric analysis of the behavior of sub-bituminous coal and cellulosic ethanol residue during co-combustion.

    Science.gov (United States)

    Buratti, C; Barbanera, M; Bartocci, P; Fantozzi, F

    2015-06-01

    The influence of the addition of cellulosic ethanol residue (CER) on the combustion of Indonesian sub-bituminous coal was analyzed by non isothermal thermo-gravimetric analysis (TGA). The effect of blends ratio (5%, 10%, 15% and 20%), interaction mechanism, and heating rate (5°C/min, 10°C/min, 15°C/min, 20°C/min) on the combustion process was studied. The results show that the increase of the blending ratio allows to achieve the increase of the combustibility index from 7.49E-08 to 5.26E-07 at the blending ratio of 20%. Two types of non-isothermal kinetic analysis methods (Ozawa-Flynn-Wall and Vyazovkin) were also applied. Results indicate that the activation energy of the blends decreases with increasing the conversion rate. In particular, the blending ratio of 20% confirms to have the better combustion performance, with the average value of the activation energy equal to 41.10 kJ/mol obtained by Ozawa-Flynn-Wall model and 31.17 kJ/mol obtained by Vyazovkin model. Copyright © 2015 Elsevier Ltd. All rights reserved.

  20. Application of experimental design in examination of the dissolution rate of carbamazepine from formulations: Characterization of the optimal formulation by DSC, TGA, FT-IR and PXRD analysis

    Directory of Open Access Journals (Sweden)

    Krstić Marko

    2015-01-01

    Full Text Available Poor solubility is one of the key reasons for the poor bioavailability of these drugs. This paper displays a formulation of a solid surfactant system with carbamazepine, in order to increase its dissolution rate. Solid state surfactant systems are formed by application of fractal experimental design. Poloxamer 237 and Poloxamer 338 were used as surfactants and Brij® 35 was used as the co-surfactant. The ratios of the excipients and carbamazepine were varied and their effects on the dissolution rate of carbamazepine were examined. Moreover, the effects of the addition of natural (diatomite and a synthetic adsorbent carrier (Neusiline UFL2 on the dissolution rate of carbamazepine were also tested. The prepared surfactant systems were characterized and the influence of the excipients on possible changes of the polymorphous form of carbamazepine examined by application of analytical techniques (DSC, TGA, FT-IR, PXRD. It was determined that an appropriate selection of the excipient type and ratio could provide a significant increase in the carbamazepine dissolution rate. By application of analytical techniques, it was found that that the employed excipients induce a transition of carbamazepine into the amorphous form and that the selected sample was stable for three months, when kept under ambient conditions. [Projekat Ministarstva nauke Republike Srbije, br. TR34007

  1. Analysis of thermal process of pozzolan production

    Directory of Open Access Journals (Sweden)

    Mejía De Gutiérrez, R.

    2004-06-01

    Full Text Available The objective of this study was evaluated the effect of heat treatment parameters on the pozzolanic activity of natural kaolin clays. The experimental design included three factors: kaolin type, temperature and time. Five types of Colombian kaolin clays were thermally treated from 400 to 1000 °C by 1, 2, and 3 hours. The raw materials and the products obtained were characterized by X-Ray Diffraction (XRD, Fourier Transform Infrared Spectroscopy (FTIR and Differential Thermal / Thermo gravimetric Analysis (DTAJ TGA. The pozzolanic activity of thermally treated samples according to chemical and mechanical tests was investigated.

    El objetivo de este estudio fue caracterizar las variables de producción de un metacaolín de alta reactividad puzolánica. El diseño experimental utilizó un modelo factorial que consideró tres factores: tipo de caolín (C, temperatura y tiempo. A partir del conocimiento de las fuentes de caolín y el contacto con proveedores y distribuidores del producto a nivel nacional, se seleccionaron cinco muestras representativas de arcillas caoliníticas, las cuales se sometieron a un tratamiento térmico entre 400 y 1.000 ºC (seis niveles de temperatura y tres tiempos de exposición, 1, 2 y 3 horas. Los caolines de origen y los productos obtenidos de cada proceso térmico fueron evaluados mediante técnicas de tipo físico y químico, difracción de rayos X, infrarrojo FTIR, y análisis térmico diferencial (OTA, TGA. Complementariamente se evalúa la actividad puzolánica, tanto química como mecánica, del producto obtenido a diferentes temperaturas de estudio.

  2. Transposition of the Greater Arteries (TGA)

    Science.gov (United States)

    ... Disease Barrett’s Esophagus Chest Wall Tumors Mediastinal Tumors Achalasia and Esophageal Motility Disorders Pleural Diseases Mesothelioma Heart ... after birth. Diagnosis and Treatment Options Diagnosis and Treatment Options TGA usually is diagnosed based on the ...

  3. Kinetics of reaction dimer fatty acid C_36 with 1,9 diamino nonane and determination of thermodynamic constants by use of thermogravimetric analysis tga, and rheological constants for the resulted polyamide

    International Nuclear Information System (INIS)

    Mohammad, H.; Falah, Al; Hammoy, M.

    2014-01-01

    Study the kinetics degradation of poly (dimeric acid C_36 with 1.9 – diamino nonane) was carried out by thermal analysis (TGA), and thermodynamic and equilibrium constants have been defined, moreover, study the kinetics of reaction between 1.9 – diamino nonane and dimer fatty acid C_36 was carried out in molten state, the reaction was performed at 160°, the acid value, and percentage of carboxylic functions of the product were determined. The polyamidation reaction was found to be of overall second order until conversion of 97% at 160°, then the order of reaction changes. The degree of dispersion, number molecular weight, weight molecular weight ,and viscosity molecular weight have been calculated during different times.The relationships between degree of dispersion, number Average molecular weight, weight average molecular weight, and viscosity molecular weight with time is linear at160°. Spectroscopy studies were carried out by infra-red and ultraviolet spectroscopy (author).

  4. A Study of the Oxidation Behaviour of Pile Grade A (PGA) Nuclear Graphite Using Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and X-Ray Tomography (XRT).

    Science.gov (United States)

    Payne, Liam; Heard, Peter J; Scott, Thomas B

    2015-01-01

    Pile grade A (PGA) graphite was used as a material for moderating and reflecting neutrons in the UK's first generation Magnox nuclear power reactors. As all but one of these reactors are now shut down there is a need to understand the residual state of the material prior to decommissioning of the cores, in particular the location and concentration of key radio-contaminants such as 14C. The oxidation behaviour of unirradiated PGA graphite was studied, in the temperature range 600-1050°C, in air and nitrogen using thermogravimetric analysis, scanning electron microscopy and X-ray tomography to investigate the possibility of using thermal degradation techniques to examine 14C distribution within irradiated material. The thermal decomposition of PGA graphite was observed to follow the three oxidation regimes historically identified by previous workers with limited, uniform oxidation at temperatures below 600°C and substantial, external oxidation at higher temperatures. This work demonstrates that the different oxidation regimes of PGA graphite could be developed into a methodology to characterise the distribution and concentration of 14C in irradiated graphite by thermal treatment.

  5. Synthesis of BiFeO 3 by carbonate precipitation

    Indian Academy of Sciences (India)

    Magnetoelectric multiferroic BiFeO3 (BFO) was synthesized by a simple carbonate precipitation technique of metal nitrate solutions. X-ray powder diffraction and thermo-gravimetric analysis (TGA) revealed that the precipitate consists of an intimate mixture of crystalline bismuth carbonate and an amorphous hydroxide of ...

  6. Fuel Fracture (Crumbling) Safety Impact (OCRWM)

    International Nuclear Information System (INIS)

    DUNCAN, D.R.

    1999-01-01

    The safety impact of experimentally observed N Reactor fuel sample fracture and fragmentation is evaluated using an average reaction rate enhancement derived from data from thermo-gravimetric analysis (TGA) experiments on fuel samples. The enhanced reaction rates attributed to fragmentation were within the existing safety basis

  7. A systematic study on the use of ultrasound energy for the synthesis of nickel-metal organic framework compounds

    NARCIS (Netherlands)

    Sargazi, G.; Afzali, D.; Daldosso, N.; Kazemian, H.; Chauhan, N.P.S.; Sadeghian, Z.; Tajerian, T.; Ghafarinazari, A.; Mozafari, M.

    2015-01-01

    A nickel metal-organic framework (Ni-MOF) was successfully synthesized using ultrasound irradiation. Further to this, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo-Gravimetric Analysis (TGA), Differential Scanning Calorimetry

  8. Reactivity studies of rice husk combustion using TGA

    International Nuclear Information System (INIS)

    Ismail, A.F.; Shamsuddin, A.H.; Mahdi, F.M.A.

    2000-01-01

    The reactivity of rice husks combustion is systematically studied the thermogravimetric analyzer (TGA). The kinetic parameters are determined from the Arrhenius plots based on the data of weight loss over temperature at different combustion heating rates. The results of proximate analysis (the moisture, volatile matters, fixed carbon, and ash contents) are also presented in this paper. The effects of process conditions on the self-ignition phenomenon of rice husk combustion are quantified. Finally, these results and compared with results for coal combustion. This research is part of the work to determine the optimal process conditions of rice husk combustion for energy production. (Author)

  9. Mathematical tool from corn stover TGA to determine its composition.

    Science.gov (United States)

    Freda, Cesare; Zimbardi, Francesco; Nanna, Francesco; Viola, Egidio

    2012-08-01

    Corn stover was treated by steam explosion process at four different temperatures. A fraction of the four exploded matters was extracted by water. The eight samples (four from steam explosion and four from water extraction of exploded matters) were analysed by wet chemical way to quantify the amount of cellulose, hemicellulose and lignin. Thermogravimetric analysis in air atmosphere was executed on the eight samples. A mathematical tool was developed, using TGA data, to determine the composition of corn stover in terms of cellulose, hemicellulose and lignin. It uses the biomass degradation temperature as multiple linear function of the cellulose, hemicellulose and lignin content of the biomass with interactive terms. The mathematical tool predicted cellulose, hemicellulose and lignin contents with average absolute errors of 1.69, 5.59 and 0.74 %, respectively, compared to the wet chemical method.

  10. Preparación y caracterización de la zeolita MCM-22 y de su precursor laminar

    Directory of Open Access Journals (Sweden)

    Pergher Sibele B. C.

    2003-01-01

    Full Text Available The layered precursor of MCM-22 was prepared with different Si/Al ratios: 15, 25, 50, 100 and ¥. Upon heat treatment these precursors form MCM-22 zeolite. Both layered precursor and MCM-22 zeolite were characterized by several techniques: Chemical Analysis by Atomic Absorption Spectroscopy (AAS, X-Ray Diffraction (XRD, Thermo-gravimetric Analysis (TGA, Pore Analysis by N2 and Ar adsorption, Scanning Electron Microscopy (SEM, Infrared Spectroscopy (IR and Temperature Programmed Desorption of ammonium (TPD.

  11. Damage sensing ability of polymer nanocomposites filled with long, shortened and damaged carbon nanotubes

    OpenAIRE

    Inam, Fawad; Okolo, Chichi; Vo, Thuc

    2016-01-01

    Carbon nanotubes (CNTs) were aggressively tip-ultrasonicated to produce shortened and damaged carbon nanotubes. High-resolution scanning electron microscopic analysis was performed to measure the dimensions of CNTs. Thermo-gravimetric analysis (TGA) was used to evaluate the damage in the sonicated CNTs. Shortened CNTs, in their pristine form (undamaged), were used for comparison with damaged CNTs. Nanocomposite bars, containing CNTs, were indented using Vickers hardness testing machine to pro...

  12. Determination of optimum thermal debinding and sintering process parameters using Taguchi Method

    CSIR Research Space (South Africa)

    Seerane, M

    2015-07-01

    Full Text Available powder and a wax-based binder. The binder’s backbone component is a low density polyethylene (LDPE). Careful selection of thermal debinding parameters was guided by thermo- gravimetric analysis (TGA) results. The Taguchi method was used to determine... International Light Metals Technology Conference (LMT 2015), Port Elizabeth, South Africa, July 27-29 Determination of Optimum Process for Thermal Debinding and Sintering using Taguchi Method SEERANE Mandya,*, CHIKWANDA Hildab, MACHAKA Ronaldc CSIR...

  13. Nitrate induction of root hair density is mediated by TGA1/TGA4 and CPC transcription factors in Arabidopsis thaliana.

    Science.gov (United States)

    Canales, Javier; Contreras-López, Orlando; Álvarez, José M; Gutiérrez, Rodrigo A

    2017-10-01

    Root hairs are specialized cells that are important for nutrient uptake. It is well established that nutrients such as phosphate have a great influence on root hair development in many plant species. Here we investigated the role of nitrate on root hair development at a physiological and molecular level. We showed that nitrate increases root hair density in Arabidopsis thaliana. We found that two different root hair defective mutants have significantly less nitrate than wild-type plants, suggesting that in A. thaliana root hairs have an important role in the capacity to acquire nitrate. Nitrate reductase-null mutants exhibited nitrate-dependent root hair phenotypes comparable with wild-type plants, indicating that nitrate is the signal that leads to increased formation of root hairs. We examined the role of two key regulators of root hair cell fate, CPC and WER, in response to nitrate treatments. Phenotypic analyses of these mutants showed that CPC is essential for nitrate-induced responses of root hair development. Moreover, we showed that NRT1.1 and TGA1/TGA4 are required for pathways that induce root hair development by suppression of longitudinal elongation of trichoblast cells in response to nitrate treatments. Our results prompted a model where nitrate signaling via TGA1/TGA4 directly regulates the CPC root hair cell fate specification gene to increase formation of root hairs in A. thaliana. © 2017 The Authors The Plant Journal © 2017 John Wiley & Sons Ltd.

  14. Thermal degradation of ligno-cellulosic fuels. DSC and TGA studies

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, V.; Cancellieri, D.; Leoni, E. [SPE-CNRS UMR 6134, University of Corsica, Campus Grossetti, BP 52, 20250 Corti (France)

    2006-12-01

    The scope of this work was to show the utility of thermal analysis and calorimetric experiments to study the thermal oxidative degradation of Mediterranean scrubs. We investigated the thermal degradation of four species; DSC and TGA were used under air sweeping to record oxidative reactions in dynamic conditions. Heat released and mass loss are important data to be measured for wildland fires modelling purpose and fire hazard studies on ligno-cellulosic fuels. Around 638 and 778K, two dominating and overlapped exothermic peaks were recorded in DSC and individualized using a experimental and numerical separation. This stage allowed obtaining the enthalpy variation of each exothermic phenomenon. As an application, we propose to classify the fuels according to the heat released and the rate constant of each reaction. TGA experiments showed under air two successive mass loss around 638 and 778K. Both techniques are useful in order to measure ignitability, combustibility and sustainability of forest fuels. (author)

  15. Soil archives of a Fluvisol: subsurface analysis and soil history of the medieval city centre of Vlaardingen, the Netherlands - an integral approach

    Science.gov (United States)

    Kluiving, Sjoerd; de Ridder, Tim; van Dasselaar, Marcel; Roozen, Stan; Prins, Maarten

    2016-06-01

    The medieval city of Vlaardingen (the Netherlands) was strategically located on the confluence of three rivers, the Maas, the Merwede, and the Vlaarding. A church of the early 8th century AD was already located here. In a short period of time, Vlaardingen developed in the 11th century AD into an international trading place and into one of the most important places in the former county of Holland. Starting from the 11th century AD, the river Maas repeatedly threatened to flood the settlement. The flood dynamics were registered in Fluvisol archives and were recognised in a multidisciplinary sedimentary analysis of these archives. To secure the future of these vulnerable soil archives an extensive interdisciplinary research effort (76 mechanical drill holes, grain size analysis (GSA), thermo-gravimetric analysis (TGA), archaeological remains, soil analysis, dating methods, micromorphology, and microfauna) started in 2011 to gain knowledge on the sedimentological and pedological subsurface of the settlement mound as well as on the well-preserved nature of the archaeological evidence. Pedogenic features are recorded with soil description, micromorphological, and geochemical (XRF - X-ray fluorescence) analysis. The soil sequence of 5 m thickness exhibits a complex mix of "natural" as well as "anthropogenic" layering and initial soil formation that enables us to make a distinction between relatively stable periods and periods with active sedimentation. In this paper the results of this interdisciplinary project are demonstrated in a number of cross-sections with interrelated geological, pedological, and archaeological stratification. A distinction between natural and anthropogenic layering is made on the basis of the occurrence of the chemical elements phosphor and potassium. A series of four stratigraphic and sedimentary units record the period before and after the flooding disaster. Given the many archaeological remnants and features present in the lower units, in

  16. Thermal stability of novel polyurethane adhesives investigated by TGA

    Directory of Open Access Journals (Sweden)

    Mariusz Mamiński

    2014-05-01

    Full Text Available The objective of the work was an assessment of thermal stability of novel polyurethane wood adhesives by means of TGA. Hyperbranched polyglycerols of various structures were used as polyol components cured with polymeric methylenediphenyldiisocyanate (PMDI or polymeric hexamethylenediisocyanate (PHDI. Resultant adhesives were thermally degraded in temperature range 20 - 500ºC. Performance of polyurethane based on fully aliphatic polyglycerol was inferior to those based on polyglycerols bearing aromatic moieties. The differences in 50%-weight loss temperature achieving 27 - 39°C as well as residual weights at 480 ºC indicate the contribution of aromatic units presence within the macromonomer structure to increased thermal stability of polyurethane upon thermal degradation. Furthermore, temperature of 50% weight loss revealed that thermal stability of the developed hyperbranched polyglycerol-based adhesives was comparable to that of the commercial PUR adhesive.

  17. Effect of pretreatments on electrodeposited epoxy coatings for electronic industries

    Directory of Open Access Journals (Sweden)

    Sironmani Palraj

    2016-02-01

    Full Text Available Waterborne epoxy coatings were prepared on aluminium (Al surfaces by cathodic electro-deposition on the pretreated surface of pickling, phosphating, chromating and anodizing. The electro-deposition experiments were done at two different voltages, 15 V and 25 V at room temperature in 10% epoxy coating formulations. Corrosion and thermal behavior of these coatings were investigated using electrochemical impedance spectroscopy (EIS and thermo gravimetric analysis (TGA. The coating exhibits better corrosion resistance in anodized Al surface than the other. But, TGA studies show that the thermal stability is higher in anodized and chromated Al surfaces. The surface morphology of these coatings were analyzed by SEM and AFM studies.

  18. Generation of drugs coated iron nanoparticles through high energy ball milling

    Energy Technology Data Exchange (ETDEWEB)

    Radhika Devi, A.; Murty, B. S. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology Madras, Chennai 600036 (India); Chelvane, J. A. [Defence Metallurgical Research Laboratory, Hyderabad 500058 (India); Prabhakar, P. K.; Padma Priya, P. V.; Doble, Mukesh [Department of Biotechnology, Indian Institute of Technology Madras, Chennai 600036 (India)

    2014-03-28

    The iron nanoparticles coated with oleic acid and drugs such as folic acid/Amoxicillin were synthesized by high energy ball milling and characterized by X-ray diffraction, Transmission electron microscope, zeta potential, dynamic light scattering, Fourier Transform Infra red (FT-IR) measurements, and thermo gravimetric analysis (TGA). FT-IR and TGA measurements show good adsorption of drugs on oleic acid coated nanoparticles. Magnetic measurements indicate that saturation magnetization is larger for amoxicillin coated particles compared to folic acid coated particles. The biocompatibility of the magnetic nanoparticles prepared was evaluated by in vitro cytotoxicity assay using L929 cells as model cells.

  19. Capsella rubella TGA4, a bZIP transcription factor, causes delayed flowering in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Li Maofu

    2016-01-01

    Full Text Available Flowering time is usually regulated by many environmental factors and endogenous signals. TGA family members are bZIP transcription factors that bind to the octopine synthase element, which has been closely linked to defense/stress responses. Most TGA factors interact with non-expressor of PR1 (NPR1 and plant defense responses are strengthened by this interaction. TGA1and TGA4factors bind to NPR1 only in salicylic acid (SA-induced leaves, suggesting that TGA4 has another function during plant development. Here, we isolated a bZIP transcription factor gene, TGA4, from Capsella rubella. TGA4transcripts were detected in most tissues, with high expression in leaves, low expression in stems and flowering buds, and undetectable in siliques. CruTGA4was over expressed in Arabidopsis thaliana wild typeCol-0 plants. Flowering time and total leaf number in the transgenic plants showed that overexpression of CruTGA4could delay flowering in A. thaliana. Our findings suggest that TGA4 may act as flowering regulator that controls plant flowering.

  20. Non-isothermal dehydration kinetic study of aspartame hemihydrate using DSC, TGA and DSC-FTIR microspectroscopy

    Directory of Open Access Journals (Sweden)

    Wei-hsien Hsieh

    2018-05-01

    Full Text Available Three thermal analytical techniques such as differential scanning calorimetry (DSC, thermal gravimetric analysis (TGA using five heating rates, and DSC-Fourier Transform Infrared (DSC-FTIR microspectroscopy using one heating rate, were used to determine the thermal characteristics and the dehydration process of aspartame (APM hemihydrate in the solid state. The intramolecular cyclization process of APM anhydrate was also examined. One exothermic and four endothermic peaks were observed in the DSC thermogram of APM hemihydrate, in which the exothermic peak was due to the crystallization of some amorphous APM caused by dehydration process from hemihydrate to anhydride. While four endothermic peaks were corresponded to the evaporation of absorbed water, the dehydration of hemihydrate, the diketopiperazines (DKP formation via intramolecular cyclization, and the melting of DKP, respectively. The weight loss measured in TGA curve of APM hemihydrate was associated with these endothermic peaks in the DSC thermogram. According to the Flynn–Wall–Ozawa (FWO model, the activation energy of dehydration process within 100–150 °C was about 218 ± 11 kJ/mol determined by TGA technique. Both the dehydration and DKP formation processes for solid-state APM hemihydrate were markedly evidenced from the thermal-responsive changes in several specific FTIR bands by a single-step DSC-FTIR microspectroscopy. Keywords: Aspartame (APM hemihydrate, DSC/TGA, DSC-FTIR, Dehydration, Activation energy, DKP formation

  1. Clinical significance of combined determination of serum TGA, TMA and TRAb in patients with hyperthyroidism

    International Nuclear Information System (INIS)

    Li Xin; Qu Wanying; Yao Zhiming; Zhao Hongshan; Xue Cuiying

    2003-01-01

    Objective: To explore the interrelationship among the three thyroid antibodies and their role in clinical diagnosis of thyroid auto-immune diseases by combined determination of serum TGA, TMA and TRAb in 84 patients with Hyperthyroidism. Methods; Based upon the serum concentrations of TGA and TMA, the 84 patients were divided into three groups; TGA, TMA negative group (TGA, TMA 6.84 u/L) in 60 of the 84 patients with hyperthyroidism (71.5%). For the separate groups, TRAb concentrations were positive in 42.9% of the patients of the TGA, TMA negative group, 75.0% of the TGA, TMA positive group and 85.7% of the strongly positive group. TRAb concentrations were significantly higher in patients of the strongly positive group than those in patients of the positive and negative group, but were not much different between patients of the positive and negative group. Conclusion: Positive rate of the serum TRAb increased along with the increase of positive rate of TGA and TMA. In this series of 84 thyrotoxic patients, TGA and TMA concentrations were strongly positive in 41.7% of them. It was possible that some of those strongly positive patients were of the Hashimoto type instead of Graves type

  2. Radiation processed hydrogels (wound dressings) for medical applications

    International Nuclear Information System (INIS)

    Varshney, Lalit

    2004-01-01

    Thermal analysis plays an important role in study and development of hydrogel materials for medical applications. Thermal stability of the ingredients which is important from the point of manufacturing, rate of evaporation for shelf life evaluation, determination of gelation and temperature responsive temperatures, cooling behaviour, gel elasticity, radiation effects etc. can be studied using thermal analysis equipment like Differential scanning calorimetry (DSC), Thermo-gravimetric analysis (TGA) and thermo-mechanical analysis (TMA). In this use of these techniques in development, evaluation and quality control of hydrogel wound dressing is discussed

  3. Study of thermal pre-treatment on anaerobic digestion of slaughterhouse waste by TGA-MS and FTIR spectroscopy.

    Science.gov (United States)

    Rodríguez-Abalde, Ángela; Gómez, Xiomar; Blanco, Daniel; Cuetos, María José; Fernández, Belén; Flotats, Xavier

    2013-12-01

    Thermogravimetric analysis coupled to mass spectrometry (TGA-MS) and Fourier-transform infrared spectroscopy (FTIR) were used to describe the effect of pasteurization as a hygienic pre-treatment of animal by-products over biogas production. Piggery and poultry meat wastes were used as substrates for assessing the anaerobic digestion under batch conditions at mesophilic range. Poultry waste was characterized by high protein and carbohydrate content, while piggery waste presented a major fraction of fat and lower carbohydrate content. Results from anaerobic digestion tests showed a lower methane yield for the pre-treated poultry sample. TGA-MS and FTIR spectroscopy allowed the qualitative identification of recalcitrant nitrogen-containing compounds in the pre-treated poultry sample, produced by Maillard reactions. In the case of piggery waste, the recalcitrant compounds were not detected and its biodegradability test reported higher methane yield and production rates. TGA-MS and FTIR spectroscopy were demonstrated to be useful tools for explaining results obtained by anaerobic biodegradability test and in describing the presence of inhibitory problems.

  4. Synthesis, characterization, and property studies of (La, Ag) FeO{sub 3} (0.0 {<=} x {<=} 0.3) perovskites

    Energy Technology Data Exchange (ETDEWEB)

    Bellakki, Manjunath B.; Kelly, Brandon J. [Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States); Manivannan, V., E-mail: mani@engr.colosate.ed [Department of Mechanical Engineering, Colorado State University, Fort Collins, Colorado 80523 (United States)

    2010-01-07

    Applying a solution - based combustion process, Ag-doped LaFeO{sub 3} orthoferrites were synthesized. The samples were characterized by multiple techniques to establish structure - property relationships. Specifically, for structural characterization, powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDX), Fourier transmission infrared spectroscopy (FTIR), Thermo-gravimetric analysis (TGA), and X-ray photoelectron microscopy (XPS) were carried out. For properties, squid magnetometer measurements (for magnetic properties), titrations (for chemical analysis), and diffuse reflectance (for optical band gap properties) measurements were carried out to elucidate structure-property relationship.

  5. Radiation-induced grafting of acrylamide onto guar gum in aqueous medium: Synthesis and characterization of grafted polymer guar-g-acrylamide

    Energy Technology Data Exchange (ETDEWEB)

    Biswal, Jayashree [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Kumar, Virendra [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Bhardwaj, Y.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)]. E-mail: ykbhard@magnum.barc.ernet.in; Goel, N.K. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Dubey, K.A. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Chaudhari, C.V. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India); Sabharwal, S. [Radiation Technology Development Section, Bhabha Atomic Research Centre, Trombay, Mumbai-400 085 (India)

    2007-10-15

    Mutual radiation grafting technique has been applied to carry out grafting of acrylamide (AAm) onto guar gum (GG) using high-energy Co{sup 60} {gamma} radiation to enhance its flocculating properties for industrial effluents. The grafted product was characterized using analytical probes like elemental analysis, thermal analysis, Fourier transformed infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscope (SEM). The grafting extent was observed to decrease with the dose rate and increase with the concentration of AAm. Thermo gravimetric analysis (TGA) of grafted and ungrafted samples indicated better stability of grafted product. {gamma} and microwave radiation effect on grafted and virgin GG has also been reported.

  6. A thermal analysis study on proprietary quick-setting mixed binder system

    International Nuclear Information System (INIS)

    Deneanu, N.; Dulama, M.; Diaconescu, C.

    2013-01-01

    The present paper presents a study, by thermal analysis, of the hydration of a mixed binder system consist of Portland composite cement type CEM II/A-M(S-LL) 32,5 R and calcium aluminate cement type GORKAL 70, patented by the authors for embedding spent radioactive solvents. Cement hydration reactions are often affected by the presence of a spent radioactive solvent, usually retarded. This process can be monitored by thermal analysis and often quantified. The data are being used as a reference to compare the changes in the cement blend hydration during the solidification caused by the presence of the spent radioactive solvents itself or by emulsifier additives which are being availed. Detailed analysis of DTG (derivative thermo gravimetric) decomposition profiles of portlandite and carbonate enabled the evaluation of admixture-related parameters concerning portlandite formation and also indicated the behaviour of specific carbonates during the hydration process. (authors)

  7. Effect of tian meng capsule treatment on serum TGA, TMA levels in patients with hashimoto's disease

    International Nuclear Information System (INIS)

    Huang Qingyi; Chen Jianfei

    2010-01-01

    Objective: To study the effect of tian meng capsule treatment on the serum levels of TGA, TMA in patients with chronic lymphocytic thyroiditis (CLTD or Hashimoto's disease). Methods: Serum TGA and TMA levels were determined with RIA both before and after treatment for 3 months in (1) 30 patients treated with conventional drugs (2) 30 patients treated with conventional drugs plus tian meng capsule (a traditional chinese medicine preparation No.2, tid) and (3) once in 30 controls. Results: Before treatment,the serum TGA and TMA levels in all the patients were significantly, higher than those in controls. After 3 months' treatment, serum TGA and TMA levels in all the patients dropped, but the levels in the patients treated with additional tian meng capsule were significantly lower than those in patients without tian meng capsule treatment. Moreover, 76.7% of the patients with tian meng capsule treatment had their serum TGA and TMA levels decreased over 30%, four patients even had the serum levels became normal. Conclusion: tian meng capsule treatment is very effective in lowering serum TGA and TMA levels in patients with Hashimoto's disease. (authors)

  8. Biological synthesis of ZnO nanoparticles using C. albicans and studying their catalytic performance in the synthesis of steroidal pyrazolines

    Directory of Open Access Journals (Sweden)

    Shamsuzzaman

    2017-05-01

    Full Text Available In this study, we describe a green and simple procedure for biosynthesis of ZnO nanoparticles using Candida albicans as eco-friendly reducing and capping agent. The synthesized ZnO nanoparticles were characterized by UV–vis spectroscopy, powder X-ray diffraction, scanning electron microscopy (SEM, transmission electron microscopy (TEM, photoluminescence (PL, thermo gravimetric analysis (TGA and differential thermal analysis (DTA. The prepared nano-particles were used as catalyst for the fast and efficient synthesis of steroidal pyrazolines (4–9 from α, β-unsaturated steroidal ketones (1–3. The target molecules were obtained in good to excellent yields applying the current method.

  9. Molecularly imprinted membrane extraction combined with high-performance liquid chromatography for selective analysis of cloxacillin from shrimp samples.

    Science.gov (United States)

    Du, Wei; Sun, Min; Guo, Pengqi; Chang, Chun; Fu, Qiang

    2018-09-01

    Nowadays, the abuse of antibiotics in aquaculture has generated considerable problems for food safety. Therefore, it is imperative to develop a simple and selective method for monitoring illegal use of antibiotics in aquatic products. In this study, a method combined molecularly imprinted membranes (MIMs) extraction and liquid chromatography was developed for the selective analysis of cloxacillin from shrimp samples. The MIMs was synthesized by UV photopolymerization, and characterized by scanning electron microscope, Fourier transform infrared spectra, thermo-gravimetric analysis and swelling test. The results showed that the MIMs exhibited excellent permselectivity, high adsorption capacity and fast adsorption rate for cloxacillin. Finally, the method was utilized to determine cloxacillin from shrimp samples, with good accuracies and acceptable relative standard deviation values for precision. The proposed method was a promising alternative for selective analysis of cloxacillin in shrimp samples, due to the easy-operation and excellent selectivity. Copyright © 2018. Published by Elsevier Ltd.

  10. Oxidation kinetics of reaction products formed in uranium metal corrosion

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    1998-01-01

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O 2 and Ar-20%O 2 were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates

  11. Physicochemical Study of Irradiated polypropylene/Organo :Modified Montmorillonite Composites by Using Electron Beam Irradiation Technique

    International Nuclear Information System (INIS)

    Hassan, M.S.

    2008-01-01

    Polypropylene/ Organo modified montmorillonite composites (PP/ OMMT) were prepared by melt blending with a twin screw extruder. The thermal properties by thermo gravimetric analysis (TGA), the dispersion of OMMT of macromolecules by X-ray diffraction (XRD), mechanical properties and the morphology by scanning electron microscopy (SEM) were investigated. The effect of electron beam irradiation on these properties was also studied. The results showed an intercalation between the silicate layers and the PP polymer matrix. The (PP/ OMMT) composites exhibit higher thermal stability and lower mechanical properties than pure polypropylene

  12. Oxidation kinetics of reaction products formed in uranium metal corrosion.

    Energy Technology Data Exchange (ETDEWEB)

    Totemeier, T. C.

    1998-04-22

    The oxidation behavior of uranium metal ZPPR fuel corrosion products in environments of Ar-4%O{sub 2} and Ar-20%O{sub 2} were studied using thermo-gravimetric analysis (TGA). These tests were performed to extend earlier work in this area specifically, to assess plate-to-plate variations in corrosion product properties and the effect of oxygen concentration on oxidation behavior. The corrosion products from two relatively severely corroded plates were similar, while the products from a relatively intact plate were not reactive. Oxygen concentration strongly affected the burning rate of reactive products, but had little effect on low-temperature oxidation rates.

  13. Measurement of serum TGA, TPOAb levels with ECLEIA in patients with Hashimoto thyroiditis

    International Nuclear Information System (INIS)

    Yu Yuanjun; Chen Qiao; Quan Cheng; Tang Jinxian

    2007-01-01

    Objective: To determine the serum autoantibodies contents during different clinical stages in patients with Hashimoto thyroiditis. Methods: Serum TGA and TPOAb were detected with chemiluminescence enzyme immunoassay (ECLEIA) and RIA simultaneously in 125 patients with Hashimoto thyroiditis. Results: HT with hyperthyroidism (12 cases) TGA: ECLEIA, (621 + 245 ) IU/ml, positive rate: 83.3%, RIA:66.7%, TPOAb: ECLEIA (452 ± 203) IU/ml, positive rates: 100%, RIA:75.0%, HT with hypothyroidism (50 cases): TGA: ECLEIA ( 1152 + 420) IU/ml. Positive Rates: 94.0%, RIA: 88.0%, TPOAb: (482 + 302) IU/ml. Positive Rates: 96.0%, RIA:90.9%; HT with normal thyroid function (63 cases): TGA: ECLEIA (230 ± 186) IU/ml. Positive Rates: 58.7%, RIA:38.1%, TPOAb:(302 ± 201)IU/ml. Positive Rates: 92.1%, RIA: 63.5%. Conclusion: Measurement of TGA and TPOAb with ECLEIA is much more sensitive than that with the conventional RIA. (authors)

  14. Thioglycolic acid (TGA) assisted hydrothermal synthesis of SnS nanorods and nanosheets

    International Nuclear Information System (INIS)

    Biswas, Subhajit; Kar, Soumitra; Chaudhuri, Subhadra

    2007-01-01

    Nanorods and nanosheets of tin sulfide (SnS) were synthesized by a novel thioglycolic acid (TGA) assisted hydrothermal process. The as prepared nanostructures were characterized by X-ray diffraction (XRD) study, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). XRD study reveals the formation of well-crystallized orthorhombic structure of SnS. Diameter of the SnS nanorods varied within 30-100 nm. High-resolution transmission electron microscopy (HRTEM) and selected area electron diffraction (SAED) patterns identify the single crystalline nature for the SnS nanocrystals. The mechanism for the TGA assisted growth for the nanosheets and nanorods have been discussed

  15. Tobacco Transcription Factor NtWRKY12 Interacts With TGA2.2 in vitro and in vivo

    Directory of Open Access Journals (Sweden)

    Marcel evan Verk

    2011-07-01

    Full Text Available The promoter of the salicylic acid-inducible PR-1a gene of Nicotiana tabacum contains binding sites for transcription factor NtWRKY12 (WK-box at position -564 and TGA factors (as-1-like element at position -592. Transactivation experiments in Arabidopsis protoplasts derived from wild type, npr1-1, tga256 and tga2356 mutant plants revealed that NtWRKY12 alone was able to induce a PR-1a::β-glucuronidase (GUS reporter gene to high levels, independent of co-expressed tobacco NtNPR1, TGA2.1, TGA2.2 or endogenous Arabidopsis NPR1, TGA2/3/5/6. By in vitro pull-down assays with GST and Strep fusion proteins and by Fluorescence Resonance Energy Transfer assays with protein-CFP and protein-YFP fusions in transfected protoplasts, it was shown that NtWRKY12 and TGA2.2 could interact in vitro and in vivo. Interaction of NtWRKY12 with TGA1a or TGA2.1 was not detectable by these techniques. A possible mechanism for the role of NtWRKY12 and TGA2.2 in PR-1a gene expression is discussed.

  16. Direct numerical simulation of the thermal dehydration reaction in a TGA experiment

    NARCIS (Netherlands)

    Lan, S.; Gaeini, M.; Zondag, H.A.; van Steenhoven, A.A.; Rindt, C.C.M.

    2018-01-01

    This work presents a detailed mathematical model of the coupled mass and heat transfer processes in salt hydrate grains in a TGA experiment. The purpose of developing this numerical model is to get a more fundamental understanding of the influence of parameters like particle size, nucleation rate

  17. Microstructural Characterization of Water-Rich Boehmite (AlO(OH)): TEM Correlation of Apparently Divergent XRD and TGA Results

    International Nuclear Information System (INIS)

    Allard, L.F.; Anovitz, L.M.; Benezeth, P.; Coffey, D.W.; Palmer, D.A.; Porter, W.D.; Wesolowski, D.J.

    1999-01-01

    An understanding of the solid-phase thermodynamics and aqueous speciation of aluminum is critical to our ability to understand and predict processes in a wide variety of geologic and industrial settings. Boehmite (AIO(OH)) is an important phase in the system Al 2 O 3 -H 2 O that has been the subject of a number of structural and thermodynamic studies since its initial synthesis [l] and discovery in nature [2]. Unfortunately, it has long been recognized that thermogravimetric analysis (TGA) of both synthetic and natural boehmite samples (that appear well crystallized by powder XRD methods) yields significant excess water - typically losing 16-16.5 wt. % on heating as compared with a nominal expected weight loss of 15.0 wt. % [3,4]. The boehmite used in our experiments was synthesized hydrothermally from acid-washed gibbsite (Al(OH) 3 ) at 200C. Powder XRD and SEM examination showed no evidence of the presence a contaminant phase. The TGA patterns do not suggest that this is due to adsorbed water, so a structural source is likely. We therefore undertook to examine this material by TEM to clarify this phenomenon

  18. Carbon conversion predictor for fluidized bed gasification of biomass fuels - from TGA measurements to char gasification particle model

    Energy Technology Data Exchange (ETDEWEB)

    Konttinen, J.T. [University of Jyvaeskylae, Department of Chemistry, Renewable Energy Programme, POB 35, Jyvaeskylae (Finland); Moilanen, A. [VTT Technical Research Centre of Finland, POB 1000, Espoo (Finland); Martini, N. de; Hupa, M. [Abo Akademi University, Process Chemistry Centre, Combustion and Materials Chemistry, Turku (Finland)

    2012-09-15

    When a solid fuel particle is injected into a hot fluidized bed, the reactivity of fuel char in gasification reactions (between char carbon and steam and CO{sub 2}) plays a significant role for reaching a good carbon conversion. In this paper, the gasification reactivity data of some solid waste recovered fuels (SRF) obtained from thermogravimetric analysis (TGA) experiments is presented. Gas mixtures (H{sub 2}O, H{sub 2}, CO{sub 2}, CO), were used in the experiments to find the inhibitive effects of CO and H{sub 2}. Average char gasification reactivity values are determined from the TGA results. Kinetic parameters for char carbon gasification reactivity correlations are determined from this data. The Uniform Conversion model is used to account for the change of gasification reaction rate as function of carbon conversion. Some discrepancies, due to complicated ash-carbon interactions, are subjects of further research. In the carbon conversion predictor, laboratory measured reactivity numbers are converted into carbon conversion numbers in a real-scale fluidized bed gasifier. The predictor is a relatively simple and transparent tool for the comparison of the gasification reactivity of different fuels in fluidized bed gasification. The residence times for solid fuels in fluidized bed gasifiers are simulated. Simulations against some pilot-scale results show reasonable agreement. (orig.)

  19. Thermogravimetric measurements of liquid vapor pressure

    International Nuclear Information System (INIS)

    Rong Yunhong; Gregson, Christopher M.; Parker, Alan

    2012-01-01

    Highlights: ► Rapid determination of vapor pressure by TGA. ► Demonstration of limitations of currently available approaches in literature. ► New model for vapor pressure assessment of small size samples in TGA. ► New model accounts for vapor diffusion and sample geometry and measures vapor pressure normally within 10%. - Abstract: A method was developed using thermo-gravimetric analysis (TGA) to determine the vapor pressure of volatile liquids. This is achieved by measuring the rate of evaporation (mass loss) of a pure liquid contained within a cylindrical pan. The influence of factors like sample geometry and vapor diffusion on evaporation rate are discussed. The measurement can be performed across a wide range of temperature yielding reasonable results up to 10 kPa. This approach may be useful as a rapid and automatable method for measuring the volatility of flavor and fragrance raw materials.

  20. Relationship between the serum TGA, TMA positiveness and development of hypothyroidism after 131I therapy in patients with Graves' disease

    International Nuclear Information System (INIS)

    Zhao Hui; Xu Xiaohong; Yu Hui

    2007-01-01

    Objective: To study the likelihood of development of hypothyroidism after 131 I therapy in patients with Graves' disease as related to the serum positiveness of TGA and TMA before treatment. Methods: Altogether, 176 patients with Graves' disease were treated with 131 I and followed for 3 years of these patients, serum TGA and TMA were positive in 70 and were negative in 106. Results: In the 70 patients with positive TGA and TMA, development of hypothyroidism after 131 I treatment occurred in 22 subjects three years later (31.4%). However, only 4 of the 106 patients with negative TGA and TMA developed hypothyroidism 3 years after 131 I therapy (3.8%). Difference in the incidence of hypothyroidism was significant (P 131 I be administered to patients with Graves' disease and positive serum TGA, TMA. (authors)

  1. Al-Mn CVD-FBR coating on P92 steel as protection against steam oxidation at 650 °C: TGA-MS study

    Science.gov (United States)

    Castañeda, S. I.; Pérez, F. J.

    2018-02-01

    The initial stages oxidation of the P92 ferritic/martensitic steel with and without Al-Mn coating at 650 °C in Ar+40%H2O for 240 h were investigated by mass spectrometry (MS) and thermogravimetric analysis (TGA). TGA-MS measurements were conducted in a closed steam loop. An Al-Mn coating was deposited on P92 steel at 580 °C for 2 h by chemical vapour deposition in a fluidized bed reactor (CVD-FBR). The coating as-deposited was treated in the same reactor at 700 °C in Ar for 2h, in order to produce aluminide phases that form the protective alumina layer (Al2O3) during oxidation. MS measurements at 650 °C of the Al-Mn/P92 sample for 200 h indicated the presence of (Al-Mn-Cr-Fe-O) volatile species of small intensity. Uncoated P92 steel oxidized under the same steam oxidation conditions emitted greater intensities of volatile species of Cr, Fe and Mo in comparison with intensities from coated steel. TGA measurements verified that the mass gained by the coated sample was up to 300 times lower than for uncoated P92 steel. The morphology, composition and structure of samples by Scanning Electron Microscopy SEM, Backscattered Electron (BSE) detection, X-ray Energy Dispersive Spectrometry (EDAX) and X-ray Diffraction (XRD) are described.

  2. Synthesis and characterization of TGA-capped CdTe nanoparticles embedded in PVA matrix

    Energy Technology Data Exchange (ETDEWEB)

    Tripathi, S.K.; Kaur, Ramneek; Sharma, Mamta [Panjab University, Department of Physics, Center of Advanced Study in Physics, Chandigarh (India)

    2014-10-25

    This paper reports the synthesis and characterization of TGA-capped CdTe nanoparticles and its nanocomposite in a PVA matrix prepared by ex situ technique. The crystallite sizes of the CdTe nanoparticles and nanocomposite calculated from X-ray diffraction patterns are 6.07 and 7.75 nm with hexagonal structure, respectively. The spherical nature of the CdTe nanoparticles is confirmed from transmission electron microscopy measurements. Fourier transform infrared spectroscopy shows good interaction between the CdTe nanoparticles and PVA matrix. The absorption and emission spectra have also been studied. The stability of the TGA-capped CdTe nanoparticles increases after dispersion in a PVA matrix. In electrical measurements, the dark conductivity and the steady-state photoconductivity of CdTe nanocomposite thin films have been studied. The effect of temperature and intensity on the transient photoconductivity of CdTe nanocomposite is also studied. The values of differential life time have been calculated from the decay of photocurrent with time. The non-exponential decay of photoconductivity is observed indicating that the traps exist at all the energies in the band gap, making these materials suitable for various optoelectronic devices. (orig.)

  3. Synthesis and characterization of TGA-capped CdTe nanoparticles embedded in PVA matrix

    International Nuclear Information System (INIS)

    Tripathi, S.K.; Kaur, Ramneek; Sharma, Mamta

    2015-01-01

    This paper reports the synthesis and characterization of TGA-capped CdTe nanoparticles and its nanocomposite in a PVA matrix prepared by ex situ technique. The crystallite sizes of the CdTe nanoparticles and nanocomposite calculated from X-ray diffraction patterns are 6.07 and 7.75 nm with hexagonal structure, respectively. The spherical nature of the CdTe nanoparticles is confirmed from transmission electron microscopy measurements. Fourier transform infrared spectroscopy shows good interaction between the CdTe nanoparticles and PVA matrix. The absorption and emission spectra have also been studied. The stability of the TGA-capped CdTe nanoparticles increases after dispersion in a PVA matrix. In electrical measurements, the dark conductivity and the steady-state photoconductivity of CdTe nanocomposite thin films have been studied. The effect of temperature and intensity on the transient photoconductivity of CdTe nanocomposite is also studied. The values of differential life time have been calculated from the decay of photocurrent with time. The non-exponential decay of photoconductivity is observed indicating that the traps exist at all the energies in the band gap, making these materials suitable for various optoelectronic devices. (orig.)

  4. Preparation and characterisation of some transition metal complexes of niacinamide (vitamin b3)

    International Nuclear Information System (INIS)

    Hasan, M.M.; Hossain, M.E.; Halim, M.E.

    2015-01-01

    Niacinamide forms metal complexes of general formula (M(C/sub 6/H/sub 6/N/sub 2/O)2)Cl/sub 2/; where M = Mn(II), Co(II), Ni(II), Cu(II) and Zn(II) in the aqueous medium. The complexes were formulated by comparing the experimental and calculated data for C, H, N and metal. The prepared complexes were characterized by different physicochemical methods. The UV-vis, FTIR spectral analysis and thermo gravimetric analysis (TGA). TGA of these complexes have been discussed. Magnetic susceptibility values indicate that all complexes except Zn complex are paramagnetic in nature. The redox properties of the metal ions in the Mn, Cu and Zn complexes have been discussed from the cyclic voltammetric studies. In all cases the systems are quasi reversible. (author)

  5. The N-Terminus of the Floral Arabidopsis TGA Transcription Factor PERIANTHIA Mediates Redox-Sensitive DNA-Binding.

    Directory of Open Access Journals (Sweden)

    Nora Gutsche

    Full Text Available The Arabidopsis TGA transcription factor (TF PERIANTHIA (PAN regulates the formation of the floral organ primordia as revealed by the pan mutant forming an abnormal pentamerous arrangement of the outer three floral whorls. The Arabidopsis TGA bZIP TF family comprises 10 members, of which PAN and TGA9/10 control flower developmental processes and TGA1/2/5/6 participate in stress-responses. For the TGA1 protein it was shown that several cysteines can be redox-dependently modified. TGA proteins interact in the nucleus with land plant-specific glutaredoxins, which may alter their activities posttranslationally. Here, we investigated the DNA-binding of PAN to the AAGAAT motif under different redox-conditions. The AAGAAT motif is localized in the second intron of the floral homeotic regulator AGAMOUS (AG, which controls stamen and carpel development as well as floral determinacy. Whereas PAN protein binds to this regulatory cis-element under reducing conditions, the interaction is strongly reduced under oxidizing conditions in EMSA studies. The redox-sensitive DNA-binding is mediated via a special PAN N-terminus, which is not present in other Arabidopsis TGA TFs and comprises five cysteines. Two N-terminal PAN cysteines, Cys68 and Cys87, were shown to form a disulfide bridge and Cys340, localized in a C-terminal putative transactivation domain, can be S-glutathionylated. Comparative land plant analyses revealed that the AAGAAT motif exists in asterid and rosid plant species. TGA TFs with N-terminal extensions of variable length were identified in all analyzed seed plants. However, a PAN-like N-terminus exists only in the rosids and exclusively Brassicaceae homologs comprise four to five of the PAN N-terminal cysteines. Redox-dependent modifications of TGA cysteines are known to regulate the activity of stress-related TGA TFs. Here, we show that the N-terminal PAN cysteines participate in a redox-dependent control of the PAN interaction with a highly

  6. Motor skill learning and offline-changes in TGA patients with acute hippocampal CA1 lesions.

    Science.gov (United States)

    Döhring, Juliane; Stoldt, Anne; Witt, Karsten; Schönfeld, Robby; Deuschl, Günther; Born, Jan; Bartsch, Thorsten

    2017-04-01

    Learning and the formation of memory are reflected in various memory systems in the human brain such as the hippocampus based declarative memory system and the striatum-cortex based system involved in motor sequence learning. It is a matter of debate how both memory systems interact in humans during learning and consolidation and how this interaction is influenced by sleep. We studied the effect of an acute dysfunction of hippocampal CA1 neurons on the acquisition (on-line condition) and off-line changes of a motor skill in patients with a transient global amnesia (TGA). Sixteen patients (68 ± 4.4 yrs) were studied in the acute phase and during follow-up using a declarative and procedural test, and were compared to controls. Acute TGA patients displayed profound deficits in all declarative memory functions. During the acute amnestic phase, patients were able to acquire the motor skill task reflected by increasing finger tapping speed across the on-line condition, albeit to a lesser degree than during follow-up or compared to controls. Retrieval two days later indicated a greater off-line gain in motor speed in patients than controls. Moreover, this gain in motor skill performance was negatively correlated to the declarative learning deficit. Our results suggest a differential interaction between procedural and declarative memory systems during acquisition and consolidation of motor sequences in older humans. During acquisition, hippocampal dysfunction attenuates fast learning and thus unmasks the slow and rigid learning curve of striatum-based procedural learning. The stronger gains in the post-consolidation condition in motor skill in CA1 lesioned patients indicate a facilitated consolidation process probably occurring during sleep, and suggest a competitive interaction between the memory systems. These findings might be a reflection of network reorganization and plasticity in older humans and in the presence of CA1 hippocampal pathology. Copyright © 2016

  7. Effects of gliadin addition on the rheological, microscopic and thermal characteristics of wheat gluten.

    Science.gov (United States)

    Khatkar, B S; Barak, Sheweta; Mudgil, Deepak

    2013-02-01

    In the present study, micro-structural, thermal and rheological changes in the gluten network upon addition of gliadins at 5% and 10% levels were investigated using scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC) and dynamic rheometry. The addition of gliadins decreased the peak dough height inferring decrease in dough strength. The dough stability also decreased from 3.20 to 1.40 min upon addition of 10% gliadin to the base flour. The TGA profile and the glass transition behavior of the control gluten and gluten obtained from dough with gliadin added at 5% and 10% levels showed decrease in thermal stability. The SEM micrograph of the control gluten showed foam like protein matrix. As the gliadin percentage in the gluten was increased, the compactness of the gluten structure reduced considerably leading to the formation of a more open weak gluten network. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Radiation-induced branching and crosslinking of poly(tetrafluoroethylene) (PTFE)

    International Nuclear Information System (INIS)

    Lappan, U.; Geissler, U.; Haeussler, L.; Jehnichen, D.; Pompe, G.; Lunkwitz, K.

    2001-01-01

    The effect of electron beams on poly(tetrafluoroethylene) (PTFE) at elevated temperatures above the melting point on oxygen-free conditions has been studied using differential scanning calorimetry (DSC), wide-angle X-ray scattering (WAXS), Fourier-transform infrared (FTIR) spectroscopy, thermo-gravimetric analysis (TGA) and tensile test. The investigations have shown that the chemical structure and several properties of PTFE are greatly altered by the irradiation. DSC and WAXS indicate that the crystallinity of the PTFE irradiated with high doses is reduced. CF 3 side groups and branched structures are assumed to hinder the crystallization. TGA has shown that the thermal stability of the radiation-modified PTFE is considerably lower than that of unirradiated PTFE

  9. Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes

    Science.gov (United States)

    Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M. Arif

    2016-05-01

    We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica.

  10. Polyacrylamide grafting of modified graphene oxides by in situ free radical polymerization

    International Nuclear Information System (INIS)

    Tang, Mingyi; Xu, Xiaoyang; Wu, Tao; Zhang, Sai; Li, Xianxian; Li, Yi

    2014-01-01

    Highlights: • Graphene oxide (GO) was modified by chemical reactions to functionalized GO (FGO). • The FGOs and the GO were then subjected to in situ free radical polymerization. • Hydroxyl groups of GO were the most reactive grafting sites. - Abstract: Graphene oxide (GO) was modified using chemical reactions to obtain three types of functionalized GO sheets (FGO). The FGO sheets and the GO were then subjected to in situ free radical polymerization in order to study the grafting polymerization. The FGO and grafted-.FGO were analyzed with Fourier transform infrared spectroscopy, scanning electronic microscopy, thermo-gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The grafting percentages in the materials were calculated using the TGA and XPS results. The FGO sheets with different functional groups exhibited different grafting abilities, and hydroxyl groups were proven to be the most reactive grafting sites for the in situ free radical grafting polymerization of polyacrylamide

  11. Synthesis, spectral studies and biological evaluation of 2-aminonicotinic acid metal complexes.

    Science.gov (United States)

    Nawaz, Muhammad; Abbasi, Muhammad Waseem; Hisaindee, Soleiman; Zaki, Muhammad Javed; Abbas, Hira Fatima; Mengting, Hu; Ahmed, M Arif

    2016-05-15

    We synthesized 2-aminonicotinic acid (2-ANA) complexes with metals such as Co(II), Fe(III), Ni(II), Mn(II), Zn(II), Ag(I),Cr(III), Cd(II) and Cu(II) in aqueous media. The complexes were characterized and elucidated using FT-IR, UV-Vis, a fluorescence spectrophotometer and thermo gravimetric analysis (TGA). TGA data showed that the stoichiometry of complexes was 1:2 metal/ligand except for Ag(I) and Mn(II) where the ratio was 1:1. The metal complexes showed varied antibacterial, fungicidal and nematicidal activities. The silver and zinc complexes showed highest activity against Bacillus subtilis and Bacillus licheniformis respectively. Fusarium oxysporum was highly susceptible to nickel and copper complexes whereas Macrophomina phaseolina was completely inert to the complexes. The silver and cadmium complexes were effective against the root-knot nematode Meloidogyne javanica. Copyright © 2016 Elsevier B.V. All rights reserved.

  12. Technical investigation of a pyrophoric event involving corrosion products from HEU ZPPR fuel plates

    International Nuclear Information System (INIS)

    Totemeier, T. C.

    2000-01-01

    A pyrophoric event recently occurred which involved corrosion products collected from highly-enriched uranium (HEU) fuel plates used in the Zero Power Physics Reactor (ZPPR). This paper summarizes the event and its background, and presents the results of an investigation into its source and mechanism. The investigation focused on characterization of corrosion product samples similar to those involved in the event using thermo-gravimetric analysis (TGA). Burning curve TGA tests were performed to measure the ignition temperature and hydride fractions of corrosion products in several different conditions to assess the effects of passivation treatment and long-term storage on chemical reactivity. The hydride fraction and ignition temperature of the corrosion products were found to be strongly dependent on the corrosion extent of the source metal. The results indicate that the energy source for the event was a considerable quantity of uranium hydride present in the corrosion products, but the specific ignition mechanism could not be identified

  13. Polyacrylamide grafting of modified graphene oxides by in situ free radical polymerization

    Energy Technology Data Exchange (ETDEWEB)

    Tang, Mingyi [Department of Applied Chemistry, School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Xu, Xiaoyang, E-mail: xiaoyangxu2012@163.com [School of Science, Tianjin University, Tianjin 30072 (China); Wu, Tao [School of Science, Tianjin University, Tianjin 30072 (China); Zhang, Sai; Li, Xianxian [Department of Applied Chemistry, School of Science, Tianjin University of Commerce, Tianjin 300134 (China); Li, Yi, E-mail: liyi@tju.edu.cn [School of Science, Tianjin University, Tianjin 30072 (China)

    2014-12-15

    Highlights: • Graphene oxide (GO) was modified by chemical reactions to functionalized GO (FGO). • The FGOs and the GO were then subjected to in situ free radical polymerization. • Hydroxyl groups of GO were the most reactive grafting sites. - Abstract: Graphene oxide (GO) was modified using chemical reactions to obtain three types of functionalized GO sheets (FGO). The FGO sheets and the GO were then subjected to in situ free radical polymerization in order to study the grafting polymerization. The FGO and grafted-.FGO were analyzed with Fourier transform infrared spectroscopy, scanning electronic microscopy, thermo-gravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). The grafting percentages in the materials were calculated using the TGA and XPS results. The FGO sheets with different functional groups exhibited different grafting abilities, and hydroxyl groups were proven to be the most reactive grafting sites for the in situ free radical grafting polymerization of polyacrylamide.

  14. Design and control of the oxygen partial pressure of UO2 in TGA using the humidification system

    International Nuclear Information System (INIS)

    Lee, S.; Knight, T.W.; Roberts, E.

    2015-01-01

    Highlights: • We focus on measurement of oxygen partial pressure and change of O/M ratio under specific conditions produced by the humidification system. • This shows that the humidification system is stable, accurate, and reliable enough to be used for experiments of the oxygen partial pressure measurement for the oxide fuels. • The humidification system has benefits of easy control and flexibility for producing various oxygen partial pressures with fixed hydrogen gas flow rate. - Abstract: The oxygen to uranium (O/U) ratio of UO 2±x is determined by the oxygen content of the sample and is affected by oxygen partial pressure (pO 2 ) of the surrounding gas. Oxygen partial pressure is controllable by several methods. A common method to produce different oxygen partial pressures is the use of equilibria of different reaction gases. There are two common methods: H 2 O/H 2 reaction and CO 2 /CO reaction. In this work, H 2 O/H 2 reaction using a humidifier was employed and investigated to ensure that this humidification system for oxygen partial pressure is stable and accurate for use in Thermogravimetric Analyzer (TGA) experiments with UO 2 . This approach has the further advantage of flexibility to make a wide range of oxygen partial pressure with fixed hydrogen gas flow rate only by varying temperature of water in the humidifier. The whole system for experiments was constructed and includes the humidification system, TGA, oxygen analyzer, and gas flow controller. Uranium dioxide (UO 2 ) samples were used for experiments and oxygen partial pressure was measured at the equilibrium state of stoichiometric UO 2.0 . Oxygen partial pressures produced by humidification (wet gas) system were compared to the approach using mixed dry gases (without humidification system) to demonstrate that the humidification system provides for more stable and accurate oxygen partial pressure control. This work provides the design, method, and analysis of a humidification system for

  15. COMPARATIVE KINETICS STUDY OF THE THERMAL AND THERMO-OXIDATIVE DEGRADATION OF A POLYSTYRENE-CLAY NANOCOMPOZITE BY TGA AND DSC

    Directory of Open Access Journals (Sweden)

    Ion Dranca

    2010-12-01

    Full Text Available The methods of thermogravimetry (TGA and differential scanning calorimetry (DSC have been used to study the thermal and thermo-oxidative degradation of polystyrene (PS and a PS-clay nanocomposite. An advanced isoconversional method has been applied for kinertic analysis. Introduction of the clay phase increasers the activation energy and affects the total heat of degradation, which suggests a change in the reaction mechanism. The obtained kinetic data permit a comparative assessment of the fire resistance of the studied materials

  16. Self-standing paper based anodes prepared from siliconcarbonitride-MoS2 composite for Li-ion battery applications

    Science.gov (United States)

    David, Lamuel; Singh, Gurpreet

    2013-03-01

    We study synthesis of free-standing polymer derived SiCN/ MoS2 composite paper anode for Li-ion battery application. This was achieved following a two-step approach: First, polysilazane was interfaced with exfoliated MoS2 nanosheets which upon pyrolysis resulted in SiCN/MoS2 composite. Second, dispersion of SiCN/MoS2 in isopropanol was vacuum filtered resulting in formation of a self-standing composite paper. Physical and chemical characterization of the composite was carried out by use of electron microscopy, Fourier transform infrared spectroscopy (FT-IR) and Thermo-gravimetric analysis (TGA). FT-IR data indicated complete conversion of polysilazane precursor to SiCN ceramic, while electron microscopy confirmed layered structure of the paper. Thermo-gravimetric analysis showed enhanced thermodynamic stability of the composite paper up to 800 °C. Electrochemical analysis of SiCN/MoS2 composite paper anodes showed that Li-ion can reversible intercalate in the voltage range of 0-2.5 V with a first cycle discharge capacity of 770 mAh/g at a current density of 100 mA/g.

  17. WRKY71 and TGA1a physically interact and synergistically regulate the activity of a novel promoter isolated from Petunia vein-clearing virus.

    Science.gov (United States)

    Shrestha, Ankita; Khan, Ahamed; Mishra, Dipti Ranjan; Bhuyan, Kashyap; Sahoo, Bhabani; Maiti, Indu B; Dey, Nrisingha

    2018-02-01

    Caulimoviral promoters have become excellent tools for efficient transgene expression in plants. However, the transcriptional framework controlling their systematic regulation is poorly understood. To understand this regulatory mechanism, we extensively studied a novel caulimoviral promoter, PV8 (-163 to +138, 301 bp), isolated from Petunia vein-clearing virus (PVCV). PVCV was found to be Salicylic acid (SA)-inducible and 2.5-3.0 times stronger than the widely used CaMV35S promoter. In silico analysis of the PV8 sequence revealed a unique clustering of two stress-responsive cis-elements, namely, as-1 1 and W-box 1-2 , located within a span of 31 bp (-74 to -47) that bound to the TGA1a and WRKY71 plant transcription factors (TFs), respectively. We found that as-1 (TTACG) and W-box (TGAC) elements occupied both TGA1a and WRKY71 on the PV8 backbone. Mutational studies demonstrated that the combinatorial influence of as-1 (-57) and W-box 1-2 (-74 and -47) on the PV8 promoter sequence largely modulated its activity. TGA1a and WRKY71 physically interacted and cooperatively enhanced the transcriptional activity of the PV8 promoter. Biotic stress stimuli induced PV8 promoter activity by ~1.5 times. We also established the possible pathogen-elicitor function of AtWRKY71 and NtabWRKY71 TFs. Altogether, this study elucidates the interplay between TFs, biotic stress and caulimoviral promoter function. Copyright © 2018 Elsevier B.V. All rights reserved.

  18. DECOMPOSIÇÃO TÉRMICA DE PELLETS DE MADEIRA POR TGA

    Directory of Open Access Journals (Sweden)

    Dorival Pinheiro Garcia

    2016-03-01

    Full Text Available A utilização dos pellets de madeira para a geração de energia térmica está se difundindo no Brasil e a termogravimetria tem sido amplamente aplicada para o estudo da decomposição da madeira e seus principais componentes como a celulose, hemiceluloses e lignina. O objetivo deste trabalho foi investigar o comportamento térmico de quatro diferentes amostras de pellets de madeira, em condições não isotérmicas, por meio das análises termogravimétricas TGA. Os ensaios foram conduzidos desde a temperatura ambiente até 500°C, com taxa de aquecimento de 20°C/min, em atmosfera inerte de gás nitrogênio, com fluxo de 100 mL/min.  Os termogramas mostraram três estágios de decomposição: o primeiro, atribuído à evaporação da água e dos materiais voláteis; o segundo, refere-se à decomposição da holocelulose na pirólise ativa; e o terceiro, atribuído a decomposição da lignina na pirólise passiva. Além disso, conclui-se que a maior decomposição térmica ocorreu na faixa de temperatura compreendida entre 250°C e 400°C, com perdas superiores a 60,8% da massa inicial do biocombustível.

  19. TGA, Hirshfeld, Raman spectroscopy and computational studies of diethylammonium hexachloroplumbate [(C2H5)2NH2]2PbCl6

    Science.gov (United States)

    Ouasri, A.; El-Adel, L.; Zouihri, H.; Rhandour, A.; Jalbout, A. F.

    2018-04-01

    Diethylammonium hexachloroplumbate [(C2H5)2NH2]2PbCl6 was found to be monoclinic with P21/n (Z = 2) as space group at room temperature. The TGA analysis shows that this compound is slightly hygroscopic and presents moisture in itself. The Raman spectrum (50-4000 cm-1) of this compound recorded at room temperature was discussed on the basis of the factor group analysis using the structural data obtained recently [5]. The experimental frequencies are compared to those obtained by Density Functional Theory (DFT) by using the B3LYP functional and the 6-31G(d) (SDD) basis set. The thermodynamic properties and geometries of this compound have been determinated and characterized. The significant intermolecular interactions in the crystal structure are identified and analyzed using the Hirshfeld surface and fingerprint plots computational methods.

  20. Synthesis of graft copolymers onto starch and its semiconducting properties

    Directory of Open Access Journals (Sweden)

    Nevin Çankaya

    Full Text Available Literature review has revealed that, although there are studies about grafting on natural polymers, especially on starch, few of them are about electrical properties of graft polymers. Starch methacrylate (St.met was obtained by esterification of OH groups on natural starch polymer for this purpose. Grafting of synthesized N-cyclohexyl acrylamide (NCA and commercial methyl methacrylate (MMA monomers with St.met was done by free radical polymerization method. The graft copolymers were characterized with FT-IR spectra, thermal and elemental analysis. Thermal stabilities of the graft copolymers were determined by TGA (thermo gravimetric analysis method and thermal stability of the copolymers is decreased via grafting. The electrical conductivity of the polymers was measured as a function of temperature and it has been observed that electrical conductivity increases with increasing temperature. The absorbance and transmittance versus wavelength of the polymers have been measured. Keywords: Starch, Graft copolymer, Semiconducting, Thermal stability, Starch methacrylate

  1. Jatropha curcas seed oil as a viable source for biodiesel

    International Nuclear Information System (INIS)

    Anwar, F.; Jamil, A.; Bhatti, H.N.; Rashid, U.

    2010-01-01

    The purpose of the present study was to explore the utility of Jatropha (Jatropha curcas) seed oil for bio diesel production. The preliminarily evaluated Jatropha oil was transmethylated under optimized set of reaction conditions: methanol/oil molar ratio (6:1), sodium methoxide catalyst concentration (1.00%), temperature (65 deg. C) and mixing intensity (600 rpm) providing 94.00% yield of Jatropha oil methyl esters (JOMEs)/biodiesel. The gas chromatographic (GC) analysis showed that JOMEs mainly comprised of six fatty acids: linoleic (49.75%), stearic (16.80%), oleic (13.00%), palmitic (12.15%), arachidic (5.01%) and gadoleic (2.00%) acids. 1H-NMR spectrum of JOMEs was also recorded. The thermal stability of the JOMEs produced was assessed by thermo gravimetric analysis (TGA). The fuel properties of the biodiesel produced were found to be within the standards specifications of ASTM D 6751 and EN 14214. (author)

  2. Growth, structural, optical, thermal and laser damage threshold studies of an organic single crystal: 1,3,5 – triphenylbenzene (TPB)

    International Nuclear Information System (INIS)

    Raja, R. Subramaniyan; Babu, G. Anandha; Ramasamy, P.

    2016-01-01

    Good quality single crystals of pure hydrocarbon 1,3,5-Triphenylbenzene (TPB) have been successfully grown using toluene as a solvent using controlled slow cooling solution growth technique. TPB crystallizes in orthorhombic structure with the space group Pna2 1 . The structural perfection of the grown crystal has been analysed by high resolution X-ray diffraction measurements. The range and percentage of the optical transmission are ascertained by recording the UV-vis spectrum. Thermo gravimetric analysis (TGA) and differential thermal analysis (DTA) were used to study its thermal properties. Powder second harmonic generation studies were carried out to explore its NLO properties. Laser damage threshold value has been determined using Nd:YAG laser operating at 1064 nm.

  3. The structural, microhardness and thermal properties of a semiorganic NLO crystal: Lithium paranitrophenolate trihydrate (NO2-C6H4-OLi.3H2O)

    International Nuclear Information System (INIS)

    Boaz, B. Milton; Raman, P. Santhana; Raja, S. Xavier Jesu; Das, S. Jerome

    2005-01-01

    The crystallographic parameters, morphology, microhardness anisotropy and thermal properties including differential thermal analysis (DTA), thermo gravimetric analysis (TGA) of a new nonlinear optical material lithium paranitrophenolate trihydrate (NPLi.3H 2 O) are reported. The single crystals of NPLi.3H 2 O show effective phase matchable second harmonic generation properties for frequency conversion. Optically clear single crystals having dimensions up to 12 mm x 8 mm x 4 mm have been grown successfully within a period of 60 days by isothermal solvent evaporation technique. The title compound crystallizes in monoclinic system with space group Pa. Microhardness measurement on different planes verifies the hardness anisotropy and thermal studies reveal good thermal stability of the material. The NLO property of the crystal is verified by employing Kurtz powder test. The crystal has a wide range of optical transparency from 400 nm to 1500 nm

  4. Synthesis and characterization of surfactant assisted Mn2+ doped ZnO nanocrystals

    Directory of Open Access Journals (Sweden)

    N. Shanmugam

    2016-09-01

    Full Text Available We report the synthesis and characterization of Mn doped ZnO nanocrystals, both in the free standing and PVP capped particle forms. The nanocrystals size could be controlled by capping them with polyvinylpyrollidone and was estimated by X-ray diffraction and transmission electron microscopy. The chemical compositions of the products were characterized by FT-IR spectroscopy. UV–Vis absorption spectroscopy measurements reveal that the capping of ZnO leads to blue shift due to quantum confinement effect. The morphology of the particles was evaluated by Scanning Electron Microscopy (SEM and Transmission Electron Microscopy (TEM. Both the Thermo Gravimetric Analysis (TGA and Differential Thermal Analysis (DTA curves of the ZnO show no further weight loss and thermal effect at a temperature above 510 °C.

  5. Synthesis of Mn doped ZnO nanoparticles with biocompatible capping

    International Nuclear Information System (INIS)

    Sharda; Jayanthi, K.; Chawla, Santa

    2010-01-01

    Free standing nanoparticles of ZnO doped with transition metal ion Mn have been prepared by solid state reaction method at 500 deg. C. X-ray diffraction (XRD) analysis confirmed high quality monophasic wurtzite hexagonal structure with particle size of 50 nm and no signature of dopant as separate phase. Incorporation of Mn has been confirmed with EDS. Bio-inorganic interface was created by capping the nanoparticles with heteromultifunctional organic stabilizer mercaptosuccinic acid (MSA). The surface morphological studies by scanning electron microscopy (SEM) showed formation of spherical particles and the nanoballs grow in size uniformly with MSA capping. MSA capping has been confirmed with thermo gravimetric analysis (TGA) and FTIR. Photoluminescence (PL) studies show that the ZnO:Mn 2+ particles are excitable by blue light and emits in orange and red. Occurrence of room temperature ferromagnetism in Mn doped ZnO makes such biocompatible luminescent magnetic nanoparticles very promising material.

  6. Fruits and vegetables dehydration

    International Nuclear Information System (INIS)

    De Ita, A; Flores, G; Franco, F

    2015-01-01

    Dehydration diagrams were determined by means of Differential Thermal Analysis, DTA, and Thermo Gravimetric Analysis, TGA, curves of several simultaneous fruits and vegetables, all under the same conditions. The greater mass loss is associated with water containing in the structure of the investigated materials at low temperature. In poblano chile water is lost in a single step. The banana shows a very sharply two stages, while jicama can be observed although with a little difficulty three stages. The major mass loss occurs in the poblano chile and the lower in banana. The velocity and temperature of dehydration vary within a small range for most materials investigated, except for banana and cactus how are very different

  7. Fruits and vegetables dehydration

    Science.gov (United States)

    de Ita, A.; Flores, G.; Franco, F.

    2015-01-01

    Dehydration diagrams were determined by means of Differential Thermal Analysis, DTA, and Thermo Gravimetric Analysis, TGA, curves of several simultaneous fruits and vegetables, all under the same conditions. The greater mass loss is associated with water containing in the structure of the investigated materials at low temperature. In poblano chile water is lost in a single step. The banana shows a very sharply two stages, while jicama can be observed although with a little difficulty three stages. The major mass loss occurs in the poblano chile and the lower in banana. The velocity and temperature of dehydration vary within a small range for most materials investigated, except for banana and cactus how are very different.

  8. Synthesis and characterization of polypyrrole doped with anionic spherical polyelectrolyte brushes

    Directory of Open Access Journals (Sweden)

    N. Su

    2012-09-01

    Full Text Available The procedures for the synthesis of polypyrrole (PPy doped with anionic spherical polyelectrolyte brushes (ASPB (PPy/ASPB nanocomposite by means of in situ chemical oxidative polymerization were presented. Fourier transform infrared spectroscopy (FTIR and Raman spectroscopic analysis suggested the bonding structure of PPy/ASPB nanocomposite. Scanning electron microscopy (SEM was used to confirm the morphologies of samples. The crystallographic structure, chemical nature and thermal stability of conducting polymers were analyzed by X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS and Thermo-gravimetric analysis (TGA respectively. Investigation of the electrical conductivity at room temperature showed that the electrical conductivity of PPy/ASPB nanocomposite was 20 S/cm, which was higher than that of PPy (3.6 S/cm.

  9. Functionalization of silica nanoparticles for polypropylene nanocomposites applications

    International Nuclear Information System (INIS)

    Bracho, Diego; Palza, Humberto; Quijada, Raul; Dougnac, Vivianne

    2011-01-01

    Synthetic silica nanospheres of different diameters produced via the sol-gel method were used in order to enhance the barrier properties of the polypropylene-silica nanocomposites. Modification of the silica surface by reaction with organic chlorosilanes was performed in order to improve the particles interaction with the polypropylene matrix and its dispersion. Unmodified and modified silica nanoparticles were characterized using electronic microscopy (TEM), elemental analysis, thermo gravimetric analysis (TGA), and solid state nuclear magnetic resonance (NMR) spectroscopy. Preliminary permeability tests of the polymer-silica nanocomposite films showed no significant change at low particles load (3 wt%) regardless its size or surface functionality, mainly because of the low aspect ratio of the silica nanospheres. However, it is expected that at a higher concentration of silica particles differences will be observed. (author)

  10. Adsorption of polyethylene glycol (PEG) onto cellulose nano-crystals to improve its dispersity.

    Science.gov (United States)

    Cheng, Dong; Wen, Yangbing; Wang, Lijuan; An, Xingye; Zhu, Xuhai; Ni, Yonghao

    2015-06-05

    In this work, the adsorption of polyethylene glycol (PEG) onto cellulose nano-crystals (CNC) was investigated for preparing re-dispersible dried CNC. Results showed that the re-dispersity of CNC in water can be significantly enhanced using a PEG1000 dosage of 5wt% (based on the dry weight of CNC). The elemental analysis confirmed the adsorption of PEG onto the CNC surface. Transmission electron microscopy (TEM) was used to characterize the dry powder and indicated that the irreversible agglomeration of CNC after drying was essentially eliminated based on the PEG adsorption concept. Thermo-gravimetric analysis (TGA) and X-ray diffraction (XRD) suggested that CNC crystallinity and thermal stability were not affected by the adsorption of PEG. Thus, the adsorption of PEG has great potential for producing re-dispersible powder CNC. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Preparation and Characterization of Silica/Polyamide-imide Nanocomposite Thin Films

    Directory of Open Access Journals (Sweden)

    Hwang Jong-Sun

    2010-01-01

    Full Text Available Abstract The functional silica/polyamide-imide composite films were prepared via simple ultrasonic blending, after the silica nanoparticles were modified by cationic surfactant—cetyltrimethyl ammonium bromide (CTAB. The composite films were characterized by scanning electron microscope (SEM, thermo gravimetric analysis (TGA and thermomechanical analysis (TMA. CTAB-modified silica nanoparticles were well dispersed in the polyamide-imide matrix, and the amount of silica nanoparticles to PAI was investigated to be from 2 to 10 wt%. Especially, the coefficients of thermal expansion (CET continuously decreased with the amount of silica particles increasing. The high thermal stability and low coefficient of thermal expansion showed that the nanocomposite films can be widely used in the enamel wire industry.

  12. Modification of mechanical and thermal property of chitosan-starch blend films

    Science.gov (United States)

    Tuhin, Mohammad O.; Rahman, Nazia; Haque, M. E.; Khan, Ruhul A.; Dafader, N. C.; Islam, Rafiqul; Nurnabi, Mohammad; Tonny, Wafa

    2012-10-01

    Chitosan-starch blend films (thickness 0.2 mm) of different composition were prepared by casting and their mechanical properties were studied. To improve the properties of chitosan-starch films, glycerol and mustard oil of different composition were used. Chitosan-starch films, incorporated with glycerol and mustard oil, were further modified with monomer 2-hydroxyethyl methacrylate (HEMA) using gamma radiation. The modified films showed improvement in both tensile strength and elongation at break than the pure chitosan-starch films. Water uptake of the films reduced significantly than the pure chitosan-starch film. Thermo gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) showed that the modified films experience less thermal degradation than the pure films. Scanning electron microscopy (SEM) and FTIR were used to investigate the morphology and molecular interaction of the blend film, respectively.

  13. Thermal and magnetic behavior of Angustifolia Kunth bamboo fibers covered with Fe3O4 particles

    International Nuclear Information System (INIS)

    Calvo, S.; Arias, N.P.; Giraldo, O.; Rosales-Rivera, A.; Moscoso, O.

    2012-01-01

    Several Angustifolia Kunth bamboo fibers, which have been previously treated with an alkaline solution, were coated with magnetite particles. The coating of the fibers was achieved by an in-situ co-precipitation method with Fe 2+ and Fe 3+ in NaOH or NH 4 OH. The fibers were evaluated by chemical analysis using atomic absorption (A.A.) technique, structural characterization by X-ray diffraction (XRD), thermal stability with thermo-gravimetric analysis (TGA) in nitrogen at temperature range between 23 °C and 800 °C and magnetic behavior using vibrating sample magnetometry (VSM) applying a magnetic field between -27 KOe and 27 KOe at room temperature. We found that the thermal stability and magnetization depend of the synthesis method used to cover the Angustifolia Kunth bamboo fibers. In addition, an improved magnetic response was observed when NaOH solution is used to generate the magnetite coating on the fiber surface.

  14. MECHANICAL ALLOYING SYNTHESIS OF FORSTERITE-DIOPSIDE NANOCOMPOSITE POWDER FOR USING IN TISSUE ENGINEERING

    Directory of Open Access Journals (Sweden)

    Sorour Sadeghzade

    2015-03-01

    Full Text Available In present study the pure forsterite-diopside nanocomposite powder was successfully synthesized by the economical method of mechanical alloying and subsequence sintering, for the first time. The starting economical materials were talc (Mg3Si4H2O12, magnesium carbonate (MgCO3 and calcium carbonate (CaCO3 powders. The prepared powder was characterized by thermo gravimetric analysis (TGA, X-ray diffraction (XRD, and scanning electron microscopy (SEM. The results showed preparation of forsterite- diopside nanocomposite powder after 10 h mechanical alloying and sintering at 1200oC for 1 h. The powder crystallite sizes and agglomerated particle sizes were measured about 73 +/- 4 nm and 0.3 - 4 μm, respectively. Absence of enstatite that causes a reduction in mechanical and bioactivity properties of forsterite ceramic, is an important feature of produced powder.

  15. Thermal plasma synthesis of Fe1−xNix alloy nanoparticles

    International Nuclear Information System (INIS)

    Raut, Suyog A.; Kanhe, Nilesh S.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2014-01-01

    Fe-Ni alloy nanoparticles are of great interest because of diverse practical applications in the fields such as magnetic fluids, high density recording media, catalysis and medicine. We report the synthesis of Fe-Ni nanoparticles via thermal plasma route. Thermal plasma assisted synthesis is a high temperature process and gives high yields of production. Here, we have used direct arc thermal plasma plume of 6kw as a source of energy at operating pressure 500 Torr. The mixture of Fe-Ni powder in required proportion (Fe 1−x Ni x ; x=0.30, 0.32, 0.34, 0.36, 0.38 and 0.40) was made to evaporate simultaneously from the graphite anode in thermal plasma reactor to form Fe-Ni bimetallic nanoparticles. The as synthesized particles were characterized by X-Ray Diffraction (XRD), Thermo-Gravimetric Analysis/Differential Scanning Calorimtry (TGA/DSC)

  16. Synthesis and characterization of new class of ionic liquids containing phenolate anion

    International Nuclear Information System (INIS)

    Lethesh, Kallidanthiyil Chellappan; Wilfred, Cecilia Devi; Taha, M. F.; Thanabalan, M.

    2014-01-01

    In these manuscript novel ionic liquids containing a new class of 'phenolate' anions was synthesized and characterized. 1-methylmidazole with different alkyl chains such as butyl, hexyl and octyl groups was used as the cationic part. All the ionic liquids were obtained as liquids at room temperature. The synthesized ionic liquids were characterized using 1 H NMR and 13 C NMR spectroscopy. The thermal stability of the ionic liquids was studied using thermo gravimetric analysis (TGA). The effect of temperature on the density and viscosity of the ionic liquids were studied over a temperature range from 293.15 K to 373.15K at atmospheric pressure. From the experimental values of density, the molecular volume, standard molar entropy and the lattice energy of the ionic liquids were calculated

  17. Synthesis and characterization of new class of ionic liquids containing phenolate anion

    Energy Technology Data Exchange (ETDEWEB)

    Lethesh, Kallidanthiyil Chellappan, E-mail: lethesh.chellappan@petronas.com.my [PETRONAS Ionic Liquids Center, Universiti Teknologi PETRONAS (Malaysia); Wilfred, Cecilia Devi; Taha, M. F. [Department of Chemical Engineering, Universiti Teknologi PETRONAS (Malaysia); Thanabalan, M. [Fundamental and Applied Sciences, Universiti Teknologi PETRONAS (Malaysia)

    2014-10-24

    In these manuscript novel ionic liquids containing a new class of 'phenolate' anions was synthesized and characterized. 1-methylmidazole with different alkyl chains such as butyl, hexyl and octyl groups was used as the cationic part. All the ionic liquids were obtained as liquids at room temperature. The synthesized ionic liquids were characterized using {sup 1}H NMR and {sup 13}C NMR spectroscopy. The thermal stability of the ionic liquids was studied using thermo gravimetric analysis (TGA). The effect of temperature on the density and viscosity of the ionic liquids were studied over a temperature range from 293.15 K to 373.15K at atmospheric pressure. From the experimental values of density, the molecular volume, standard molar entropy and the lattice energy of the ionic liquids were calculated.

  18. Investigation on polyetheretherketone composite for long term storage of nuclear waste

    Science.gov (United States)

    Ajeesh, G.; Bhowmik, Shantanu; Sivakumar, Venugopal; Varshney, Lalit; Kumar, Virendra; Abraham, Mathew

    2015-12-01

    This investigation highlights the effect of radiation, chemical and thermal environments on mechanical and thermal properties of Polyetheretherketone (PEEK) composites, which could prove to be an alternative material for long term storage of nuclear wastes. The tests are conducted on specimens made from PEEK and PEEK reinforced with carbon short fiber. The specimens are subjected to radiation doses, equivalent to the cumulative dosage for 500 years followed by exposure under highly corrosive and thermal environments. Studies under optical microscopy reveal that the dispersion of carbon short fiber in the PEEK Composites is significantly uniform. Differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) indicates that there are no significant changes in thermal properties of PEEK composite when exposed to aggressive environments. It is further observed that there are no significant changes in mechanical properties of the composite after exposure to radiation and thermo-chemical environment.

  19. Synthesis and characterization of composite based on cellulose acetate and hydroxyapatite application to the absorption of harmful substances.

    Science.gov (United States)

    Azzaoui, Khalil; Lamhamdi, Abdelatif; Mejdoubi, El Miloud; Berrabah, Mohammed; Hammouti, Belkheir; Elidrissi, Abderrahman; Fouda, Moustafa M G; Al-Deyab, Salem S

    2014-10-13

    The aim of this work is to develop composite materials with hydroxyapatite (HAp) mineral and organic matrix such as cellulosic polymers. We use cellulose acetate with different percentages, and then inorganic-organic films were fabricated by evaporation of solvent. The composite films were characterized using emission scanning electron microscopy (FEG-SEM), thermo-gravimetric analysis (TGA) and Fourier transform infra-red (FT-IR) spectra. Test results show that these films are uniform and have good ductility. A strong interaction existed between HAp and cellulosic polymers, and the method allows the production of very fine particles size of about 92 nm. We have developed a new chromatographic method for the quantification of bisphenol A (BPA) in samples of baby food. The result of this study demonstrates how to use this type of composite materials to remove pollutants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Structure and properties of hydroxyapatite/hydroxyethyl cellulose acetate composite films.

    Science.gov (United States)

    Azzaoui, K; Mejdoubi, E; Lamhamdi, A; Zaoui, S; Berrabah, M; Elidrissi, A; Hammouti, B; Fouda, Moustafa M G; Al-Deyab, Salem S

    2015-01-22

    The main aim of this research work was to develop a new inorganic-organic film. Hydroxyapaptite (HAp) particles that represent the inorganic phase was mixed well with hydroxyethyl cellulose acetate (HECA), which representing the organic phase and then the inorganic-organic films were fabricated by evaporating of the solvent. The structure as well as the properties of the formed films were characterized using different analytical tools such as field emission scanning electron microscopy (FEG-SEM), thermo-gravimetric analysis (TGA), Fourier transform infra-red (FT-IR) spectroscopy. The obtained results revealed that, the HAp nanoparticles was well dispersed and well immobilized throughout the formed films. This can be attributed to the role of the nano- and micropores in the HECA substrate. In addition, a strong interaction occurred between HAp and HECA matrix. The results showed also good thermal stability and miscibility as well. Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. Hydroxyapatite-alginate nanocomposite as drug delivery matrix for sustained release of ciprofloxacin.

    Science.gov (United States)

    Venkatasubbu, G Devanand; Ramasamy, S; Ramakrishnan, V; Kumar, J

    2011-12-01

    Hydroxyapatite is a bioceramic which has a wide range of medical application for bone diseases. To enhance its usage, we have prepared ciprofloxacin loaded nano hydroxyapatite (HA) composite with a natural polymer, alginate, using wet chemical method at low temperature. The prepared composites were analyzed by various physicochemical methods. The results show that the nano HA crystallites are well intact with the alginate macromolecules. For the composite system FT-IR and micro Raman results are reported in this paper. Studies on the drug loading and drug release have been done. The drug is pre-adsorbed onto the ceramic particle before the formation of composite. The thermal behavior of composite has been studied using thermo gravimetric analysis (TGA). This work, reports that the nanocomposite prepared under optimum condition could prolong the release of ciprofloxacin compared with the ciprofloxacin loaded hydroxyapatite.

  2. Preparation of porous carbon particle with shell/core structure

    Directory of Open Access Journals (Sweden)

    2007-05-01

    Full Text Available Porous carbon particles with a shell/core structure have been prepared successfully by controlled precipitation of the polymer from droplets of oil-in-water emulsion, followed by curing and carbonization. The droplets of the oil phase are composed of phenolic resin (PFR, a good solvent (ethyl acetate and porogen (Poly(methyl methacrylate, PMMA. The microstructure was characterized in detail by scanning electron microscopy (SEM, transmission electron microscopy (TEM, nitrogen adsorption, and thermo gravimetric analysis (TGA. The obtained carbon particles have a capsular structure with a microporous carbon shell and a mesoporous carbon core. The BET surface area and porous volume are calculated to be 499 m2g-1 and 0.56 cm3g-1, respectively. The effects of the amount of porogen (PMMA, co-solvent (acetone and surfactant on the resultant structure were studied in detail.

  3. Synthesis of single-crystalline hollow β-FeOOH nanorods via a controlled incomplete-reaction course

    International Nuclear Information System (INIS)

    Yu Haiyun; Song Xinyu; Yin Zhilei; Fan Weiliu; Tan Xuejie; Fan Chunhua; Sun Sixiu

    2007-01-01

    The single-crystalline β-FeOOH hollow nanorods with a diameter ranging from 20∼30 nm and length in the range of 70-110 nm have been successfully synthesized through a two-step route in the solution. The phase transformation and the morphologies of the hollow β-FeOOH nanorods were investigated with X-ray powdered diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), selected area electric diffraction (SAED), high-resolution transmission electron microscopy (HRTEM), infrared spectrum (IR) and thermo-gravimetric analysis (TGA). These studies indicate that the first step is an incomplete-reaction course. Furthermore, The formation mechanism of the hollow nanorods has been discussed. It is found that the mixed system including chitosan and n-propanol is essential for the final formation of the hollow β-FeOOH nanorods

  4. Photocatalytic polymerization induced by a transparent anatase titania aqueous sol and fabrication of polymer composites

    Directory of Open Access Journals (Sweden)

    2010-06-01

    Full Text Available The surface modification of the anatase titania nanoparticles prepared via a controlled nonhydrolytic sol-gel process is achieved by the formation of the bidentate coordination between titania and methacrylic acid (MAA molecules. The in situ photocatalytic polymerization of methyl methacrylate (MMA monomer is initiated by surface modified anatase titania nanoparticles under Xe lamp irradiation. A variety of techniques including differential scanning calorimetry (DSC, thermo-gravimetric analysis (TGA and scanning electron microscopy (SEM are employed to characterize the resulting materials. The glass transition temperatures and the thermal stabilities of polymethyl methacrylate (PMMA composite materials prepared via photocatalytic polymerization are enhanced compared with pure polymer. The partial aggregation of titania nanoparticles in PMMA composite films is derived from the surface polymerization of MMA, which makes the inorganic particles hydrophobic and drives them to the water/oil interfaces.

  5. Mussel inspired polymerized P(TA-TETA) for facile functionalization of carbon nanotube

    Science.gov (United States)

    Si, Shuxian; Gao, Tingting; Wang, Junhao; Liu, Qinze; Zhou, Guowei

    2018-03-01

    This article describes a novel and effective approach for non-covalent modification of carbon nanotube (CNT) via the mussel inspired polymerization of tannic acid (TA) and triethylenetetramine (TETA) and subsequent surface initiated atom transfer radical polymerization (SI-ATRP). Fourier transform infrared spectroscopy (FT-IR), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS) and photograph were used to study the successful preparation of polymer brush grafted CNT (CNT-P(TA-TETA)-PDMAEMA) composite as well as the pH-responsive behavior of the composite. Furthermore, by amine protonation and in situ reduction, gold nanoparticles were successfully uploaded and the catalytic property of CNT-P(TA-TETA)-PDMAEMA/Au was investigated. We believe that the surface functionalization strategy can be extended to graphene and other substrates, and the surface properties can be regulated by grafting polymer brushes with different functionalities.

  6. Radiation processing of Garcinia cambogia

    International Nuclear Information System (INIS)

    Francis, Sanju; Varshney, Lalit

    2001-01-01

    Garcinia Cambogia (GC) extract is used in controlling obesity and many health related problems. Being a natural product, locally known as cocum powder, is often contaminated with various microbiological species. Ability of g-radiation is well established to eliminate such species and it could be used to protect the quality of the product. In the present study, GC extract was subjected to g-radiation dose in order to evaluate the stability of its active ingredients. High Performance Liquid Chromatography (HPLC) with Diode Array Detector (DAD) and Thermo-Gravimetric analysis (TGA) were used to evaluate the product stability. No significant physico-chemical changes were observed in GC at 30 kGy. GC could be sterilized or decontaminated in dry powder form using gamma radiation without affecting its physico-chemical properties. (author)

  7. Investigation on polyetheretherketone composite for long term storage of nuclear waste

    International Nuclear Information System (INIS)

    Ajeesh, G.; Bhowmik, Shantanu; Sivakumar, Venugopal; Varshney, Lalit; Kumar, Virendra; Abraham, Mathew

    2015-01-01

    This investigation highlights the effect of radiation, chemical and thermal environments on mechanical and thermal properties of Polyetheretherketone (PEEK) composites, which could prove to be an alternative material for long term storage of nuclear wastes. The tests are conducted on specimens made from PEEK and PEEK reinforced with carbon short fiber. The specimens are subjected to radiation doses, equivalent to the cumulative dosage for 500 years followed by exposure under highly corrosive and thermal environments. Studies under optical microscopy reveal that the dispersion of carbon short fiber in the PEEK Composites is significantly uniform. Differential scanning calorimeter (DSC) and thermo gravimetric analysis (TGA) indicates that there are no significant changes in thermal properties of PEEK composite when exposed to aggressive environments. It is further observed that there are no significant changes in mechanical properties of the composite after exposure to radiation and thermo-chemical environment.

  8. Synthesis and characterization of (S)-amino alcohol modified M41S as effective material for the enantioseparation of racemic compounds.

    Science.gov (United States)

    Mayani, Vishal J; Abdi, S H R; Kureshy, R I; Khan, N H; Agrawal, Santosh; Jasra, R V

    2006-12-01

    A new chiral stationary phase (CSP) was synthesized based on (S)-1-anilino-3-propyl-2-propanol covalently bonded to the mesoporous semi-crystalline material M41S. Direct semipreparative enantioseparation of mandelic acid could be achieved using medium pressure chromatography. Partly separated could also be the enantiomers of 2,2'-dihydroxy-1,1'-binaphthalene, cyanochromene oxide, diethyl tartrate and 2-phenyl propionic acid. The characterization of CSP was accomplished by microanalysis, cross polarized magic angle spinning (CP-MAS) 13C NMR, powder X-ray diffraction (XRD), FTIR, thermo-gravimetric analysis (TGA), N2 adsorption-desorption isotherm, scanning electron microscopy (SEM) and solid reflectance UV-vis spectroscopy. Furthermore the stability of CSP was satisfactory as it could withstand three washing and reuse experiments of enantioseparation of mandelic acid without loss in its performance.

  9. A novel, efficient and facile method for the template removal from mesoporous materials

    KAUST Repository

    Chen, Lu

    2014-11-12

    © 2014, Jilin University, The Editorial Department of Chemical Research in Chinese Universities and Springer-Verlag GmbH. A new catalytic-oxidation method was adopted to remove the templates from SBA-15 and MCM-41 mesoporous materials via Fenton-like techniques under microwave irradiation. The mesoporous silica materials were treated with different Fenton agents based on the template’s property and textural property. The samples were characterized by powder X-ray diffraction(XRD) measurement, N2 adsorption-desorption isotherms, infrared spectroscopy, 29Si MAS NMR and thermo gravimetric analysis(TGA). The results reveal that this is an efficient and facile approach to the thorough template-removal from mesoporous silica materials, as well as to offering products with more stable structures, higher BET surface areas, larger pore volumes and larger quantity of silanol groups.

  10. Synthesis, physicochemical and optical properties of bis-thiosemicarbazone functionalized graphene oxide

    Science.gov (United States)

    Kumar, Santosh; Wani, Mohmmad Y.; Arranja, Claudia T.; Castro, Ricardo A. E.; Paixão, José A.; Sobral, Abilio J. F. N.

    2018-01-01

    Fluorescent materials are important for low-cost opto-electronic and biomedical sensor devices. In this study we present the synthesis and characterization of graphene modified with bis-thiosemicarbazone (BTS). This new material was characterized using Fourier transform infrared spectroscopy (FT-IR), Ultraviolet-visible (UV-Vis) and Raman spectroscopy techniques. Further evaluation by X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), scanning electron microscopy (SEM) and atomic-force microscopy (AFM) allowed us to fully characterize the morphology of the fabricated material. The average height of the BTSGO sheet is around 10 nm. Optical properties of BTSGO evaluated by photoluminescence (PL) spectroscopy showed red shift at different excitation wavelength compared to graphene oxide or bisthiosemicarbazide alone. These results strongly suggest that BTSGO material could find potential applications in graphene based optoelectronic devices.

  11. Environmentally friendly road construction

    Directory of Open Access Journals (Sweden)

    A.I. Essawy

    2013-06-01

    Full Text Available Environmental pollution is a major problem in developing countries like Egypt. Reuse of waste polymers is considered an attractive solution for environmental white pollution and reducing of the costs of road pavement and maintenance. This research aims to prepare environmentally friendly hot mix asphalt (HMA for paving using some industrial wastes as polypropylene and polyester fibers. The solid materials in the mix include normal and highly porous aggregates. 5% and 10% of waste polymers by weight of the asphalt were used to prepare special binders. The samples were tested for their physical properties, chemical properties, aging, scanning electron microscopy (SEM and thermo-gravimetric analysis (TGA. The results revealed that the prepared HMA using 5% of waste polymer had high performance as compared to the ordinary one and the waste polymer could be used in road construction.

  12. Synthesis Magnesium Hydroxide Nanoparticles and Cellulose Acetate- Mg(OH2-MWCNT Nanocomposite

    Directory of Open Access Journals (Sweden)

    M. Ghorbanali

    2015-04-01

    Full Text Available Mg(OH2 nanoparticles were synthesized by a rapid microwave reaction. The effect of sodium dodecyl sulfonate (SDS as anionic surfactant and cetyl tri-methyl ammonium bromide (CTAB as cationic surfactant on the morphology of magnesium hydroxide nanostructures was investigated. Multi wall carbon nano tubes was organo-modified for better dispersion in cellulose acetate matrix. The influence of Mg(OH2 nanoparticles and modified multi wall carbon nano tubes (MWCNT on the thermal stability of the cellulose acetate (CA matrix was studied using thermo-gravimetric analysis (TGA. Nanostructures were characterized by X-ray diffraction (XRD, scanning electron microscopy (SEM and Fourier transform infrared (FT-IR spectroscopy. Thermal decomposition of the nanocomposites shift towards higher temperature in the presence of Mg(OH2 nanostructures. The enhancement of thermal stability of nanocomposites is due to the endothermic decomposition of Mg(OH2 and release of water which dilutes combustible gases.

  13. Synthesis and characterization of kaolin with polystyrene via in-situ polymerization and their application on polypropylene

    International Nuclear Information System (INIS)

    Zhao, Songfang; Qiu, Shangchang; Zheng, Yuying; Cheng, Lei; Guo, Yong

    2011-01-01

    To improve both the mechanical and thermal properties of kaolin/polypropylene (PP) composites, kaolin was modified by using 3-(trimethoxysilyl) propylmethacrylate (YDH-570) as a coupling agent to form polymerizable particle. Styrene was radically polymerized through the immobilized vinyl using benzoyl peroxide (BPO) as an initiator. Fourier transform-infrared (FTIR) spectroscopy, particle size distribution, X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA) well demonstrated that the kaolin-polystyrene particles were successfully synthesized via in-situ polymerization. While the modified kaolin and raw kaolin were introduced into the PP matrix, it could be concluded that modified kaolin/PP composites have better mechanical and thermal properties than raw kaolin/PP composites, and these improvements were attributed to the desirable dispersion of kaolin in PP matrix.

  14. A study on dehydration of rare earth chloride hydrate

    International Nuclear Information System (INIS)

    Cho, Yong Zun; Eun, Hee Chul; Son, Sung Mo; Lee, Tae Kyo; Hwang, Taek Sung

    2012-01-01

    The dehydration schemes of rare earth (La, Ce, Nd, Pr, Sm. Eu, Gd, Y) chloride hydrates was investigated by using a dehydration apparatus. To prevent the formation of the rare earth oxychlorides, the operation temperature was changed step by step (80→150→230 degree C) based on the TGA (thermo-gravimetric analysis) results of the rare earth chloride hydrates. A vacuum pump and preheated Ar gas were used to effectively remove the evaporated moisture and maintain an inert condition in the dehydration apparatus. The dehydration temperature of the rare earth chloride hydrate was increased when the atomic number of the rare earth nuclide was increased. The content of the moisture in the rare earth chloride hydrate was decreased below 10% in the dehydration apparatus.

  15. Analysis of briquetting process of sewage sludge with coal to combustion process

    Directory of Open Access Journals (Sweden)

    Kosturkiewicz Bogdan

    2016-01-01

    Full Text Available Energy recovery from sewage sludge can be achieved by several thermal technologies, but before those processes sewage sludge requires special pretreatment. The paper presents the investigation of the sewage sludge with coal briquettes as a fuel for combustion process. Research is conducted at Department of Manufacturing Systems and Department of Thermal Engineering and Environmental Protection, AGH University of Science and Technology to develop a technology of briquette preparation. The obtained results showed possibility of briquetting of municipal sewage sludge with coal in roll presses, equipped with asymmetric thickening gravity feed system. The following properties were determined for the obtained briquettes: density, drop strength and compressive strength. Based on physical and chemical analysis of prepared briquettes it was confirmed that briquettes have good fuel properties to combustion process. Thermal behaviour of studied sewage sludge and prepared mixture was investigated by thermogravimetric analysis (TG. For the thermo gravimetric analysis (TG the samples were heated in an alumina crucible from an ambient temperature up to 1000 °C at a constant rates: 10 °C/min, 40 °C/min and 100 °C/min in a 40 ml/min flow of air.

  16. Effects of water vapor on protectiveness of Cr2O3 scale at 1073 K

    Science.gov (United States)

    Arifin, S. K.; Hamid, M.; Berahim, A. N.; Ani, M. H.

    2018-01-01

    Fe-Cr alloy is commonly being used as boiler tube’s material. It is subjected to prolonged exposure to water vapor oxidation. The ability to withstand high temperature corrosion can normally be attributed to the formation of a dense and slow growing Cr-rich-oxide scale known as chromia, Cr2O3 scale. However, oxidation may limit the alloy’s service lifetime due to decreasing of its protectiveness capability. This paper is to presents an experimental study of thermo gravimetric and Fourier transform infrared analysis of Cr2O3 at 1073 K in dry and humid environment. Samples were used from commercially available Cr2O3 powder. It was cold-pressed into pellet shape of 12 mm diameter and 3 mm thick with hydraulic press for 40 min at 48 MPa. It then sintered at 1173 K in inert gas environment for 8 h. The samples are cooled and placed in 5 mm diameter platinum pan. It is subjected to reaction in dry and wet environment at 1073 K by applying 100%-Ar and Ar-5%H2 gas. Each reaction period is 48 h utilizing Thermo Gravimetric Analyzer, TGA to quantify the mass changes. After the reaction, the samples then characterized with Fourier Transform Infrared Spectroscopy, FT-IR and Field Emission Electron Scanning Microscopy, FE-SEM. The TGA result shows mass decreasing ratio of Cr2O3 in wet (PH2O = 9.5x105Pa) and dry environment is at a factor of 1.2 while parabolic rate at 1.4. FT-IR results confirmed that water vapor significantly broaden the peaks, thus promotes the volatilization of Cr2O3 in wet sample. FESEM shows mostly packed and intact in dry while in wet sample, slightly porous particle arrangement compare to dry. It is concluded that water vapor species decreased Cr2O3 protectiveness capability.

  17. Morphological Changes of Limestone Sorbent Particles during Carbonation/Calcination Looping Cycles in a Thermogravimetric Analyzer (TGA) and Reactivation with Steam

    KAUST Repository

    Wu, Y.; Blamey, J.; Anthony, E. J.; Fennell, P. S.

    2010-01-01

    Carbonation and calcination looping cycles were carried out on four limestones in a thermogravimetric analyzer (TGA). The CO2 carrying capacity of a limestone particle decays very quickly in the first 10 cycles, reducing to about 20% of its original

  18. Characterization of UO{sub 2}, a) Characterization of UO{sub 2} powder; b) Investigation of U-O system by DDK and TGA methods; Karakterizacija UO{sub 2}, a) Karakterizacija praha UO{sub 2}; b) Ispitivanje sistema U-O metodama DDK i TGA

    Energy Technology Data Exchange (ETDEWEB)

    Ristic, M M [Institute of Nuclear Sciences Vinca, Laboratorija za reaktorske materijale, Beograd (Serbia and Montenegro)

    1962-10-15

    The objectives of the study of U-O powder system were: detailed characterization of the UO{sub 2} powder which will be used for studying the sintering process, and more detailed properties of the U-O system (thermodynamic aspects of oxidation kinetics). Study of the physical and chemical properties of UO{sub 2} powder were performed and then oxidation kinetics of UO{sub 2} {yields}U{sub 3}O{sub 7} was investigated. Detailed qualitative DDK analysis was done. Owing to the TGA equipment there was a possibility to obtain U{sub 3}O{sub 7} study of U{sub 3}O{sub 7} {yields} U{sub 3}O{sub 8} oxidation was possible.

  19. Characterization of Amazon fibers of the peach palm, balsa, and babassu by XDR, TGA and NMR

    International Nuclear Information System (INIS)

    Martins, Maria A.; Marconcini, Jose M.; Morelli, Carolina L.; Marinelli, Alessandra L.; Bretas, Rosario E.S.

    2011-01-01

    The aim of this work was to present the results by testing X-ray diffraction (XRD), thermogravimetric analysis (TG), nuclear magnetic resonance (NMR) and determining the moisture content of the peach palm, balsa and babassu fibers for assessing the feasibility of composite materials. The fibers of peach palm, balsa and babassu showed characteristic chemical structure of lignocellulosic material, and good thermal stability up to 220 deg C. The fiber with the highest crystallinity index (Ic) is the peach palm (72%) and the less crystalline is the babassu (37%), while the balsa fibers have Ic equal to 64%. The results have shown that these fibers can be used in the manufacture of composite materials. (author)

  20. Thermal analysis and its application in evaluation of fluorinated polyimide membranes for gas separation

    KAUST Repository

    Qiu, Wulin; Chen, Chien-Chiang; Kincer, Matthew R.; Koros, William J.

    2011-01-01

    by reaction with acetic anhydride to produce polyimide (PI). The resulting polymers were characterized using thermal analysis techniques including TGA, derivative weight analysis, TGA-MS, and DSC. The decarboxylation-induced thermal cross-linking, ester cross

  1. Fluorescence Determination of Warfarin Using TGA-capped CdTe Quantum Dots in Human Plasma Samples.

    Science.gov (United States)

    Dehbozorgi, A; Tashkhourian, J; Zare, S

    2015-11-01

    In this study, some effort has been performed to provide low temperature, less time consuming and facile routes for the synthesis of CdTe quantum dots using ultrasound and water soluble capping agent thioglycolic acid. TGA-capped CdTe quantum dots were characterized through x-ray diffraction, transmission electron microscopy, Fourier transform infrared, ultraviolet-visible and fluorescence spectroscopy. The prepared quantum dots were used for warfarin determination based on the quenching of the fluorescence intensity in aqueous solution. Under the optimized conditions, the linear range of quantum dots fluorescence intensity versus the concentration of warfarin was 0.1-160.0 μM, with the correlation coefficient of 0.9996 and a limit of detection of 77.5 nM. There was no interference to coexisting foreign substances. The selectivity of the sensor was also tested and the results show that the developed method possesses a high selectivity for warfarin.

  2. Novel measurement method of activation energy of non-metallic materials for NPP

    International Nuclear Information System (INIS)

    Park, Chang-Dae; Lim, Byung-Ju; Song, Chi-Sung

    2008-01-01

    This paper presents novel technique and its applicability for measuring activation energy of non-metallic materials for NPPs (nuclear power plants). The E a is a principal property for life assessment and accelerating thermal aging of equipment during environmental qualification. The E a is conventionally obtained by tensile test using UTM (Universal Testing Machine). However, this conventional method has many difficulties such as lots of big standardized specimens required and long measuring time of at least 3 months. Moreover, this is not only an inapplicable method during inservice inspection but destructive method, which are main obstacles for using UTM. Fortunately, newly developed technique for the E a such as TGA (Thermo-gravimetric Analysis) and DMA (Dynamic Mechanical Analysis) can eliminate almost all the problems of UTM. The common TGA is to measure weight change with time under constant heating rate. TGA was devised to perform the compositional analysis of materials such as rubber, carbon black, filler, volatile, etc., and to determine the thermal stability/decomposition, stoichiometry of reactions, and kinetics of reaction, by weight changes of materials when heated. TGA method has various advantages such as small amount of the sample (e.g. 20 mg), shortened measuring time of approximately 2 days, and virtually non-destructive method. In this study, we have tried to find the justification of TGA utilization for E a measurement by comparing the measured TGA data to UTM data for three cable materials. Considering reasonable consistency of our TGA data with UTM data, we conclude that TGA method gives convenient way to measure the activation energy for EPR, CR, and CSP materials with many merits, such as measuring time, specimen size and quantity required, and test expenses. (author)

  3. Combined TGA-MS kinetic analysis of multistep processes. Thermal decomposition and ceramification of polysilazane and polysiloxane preceramic polymers.

    Science.gov (United States)

    García-Garrido, C; Sánchez-Jiménez, P E; Pérez-Maqueda, L A; Perejón, A; Criado, José M

    2016-10-26

    The polymer-to-ceramic transformation kinetics of two widely employed ceramic precursors, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane (TTCS) and polyureamethylvinylsilazane (CERASET), have been investigated using coupled thermogravimetry and mass spectrometry (TG-MS), Raman, XRD and FTIR. The thermally induced decomposition of the pre-ceramic polymer is the critical step in the synthesis of polymer derived ceramics (PDCs) and accurate kinetic modeling is key to attaining a complete understanding of the underlying process and to attempt any behavior predictions. However, obtaining a precise kinetic description of processes of such complexity, consisting of several largely overlapping physico-chemical processes comprising the cleavage of the starting polymeric network and the release of organic moieties, is extremely difficult. Here, by using the evolved gases detected by MS as a guide it has been possible to determine the number of steps that compose the overall process, which was subsequently resolved using a semiempirical deconvolution method based on the Frasier-Suzuki function. Such a function is more appropriate that the more usual Gaussian or Lorentzian functions since it takes into account the intrinsic asymmetry of kinetic curves. Then, the kinetic parameters of each constituent step were independently determined using both model-free and model-fitting procedures, and it was found that the processes obey mostly diffusion models which can be attributed to the diffusion of the released gases through the solid matrix. The validity of the obtained kinetic parameters was tested not only by the successful reconstruction of the original experimental curves, but also by predicting the kinetic curves of the overall processes yielded by different thermal schedules and by a mixed TTCS-CERASET precursor.

  4. Bronsted acid site number evaluation using isopropylamine decomposition on Y-zeolite contaminated with vanadium in a simultaneous DSC-TGA analyzer

    International Nuclear Information System (INIS)

    Osorio Perez, Yonnathan; Forero, Liliam Alexandra Palomeque; Torres, Diana Vanessa Cristiano; Trujillo, Carlos Alexander

    2008-01-01

    Acid-site catalyzed decomposition of isopropylamine was followed in a simultaneous DSC-TGA analyzer. USY zeolite samples with and without vanadium were studied. Results show that acid sites number decreases linearly with vanadium concentration in zeolite indicating that vanadium neutralizes acid sites on catalyst and the metal is able to move on the surface of the solid. The neutralizing species probably contain only one vanadium atom. The reaction enthalpy plus desorption heat of the products show that vanadium preferentially neutralizes the strongest acid sites on the zeolite. The application of the simultaneous DSC-TGA technique to quantify Bronsted acid sites on solids by this reaction is novel

  5. Changes of serum FT3, FT4, sTSH, TRAb, TGA and TMA concentrations in Graves' patients treated with 131I and clinical significances

    International Nuclear Information System (INIS)

    Sun Wenwei; Wei Liqin; Zhao Jie; Ma Qingjie; Sun Hui

    2006-01-01

    Objective: To study the clinical significances of serum FT 3 , FT 4 , sTSH, TRAb, TGA and TMA concentration changes in Graves' patients before and after, 131 I treatment. Methods: The serum FT 3 , FT 4 , sTSH; TRAb, TGA and TMA concentrations before treatment, 3, 6, 12 and 18 months after therapy in 172 Graves' patients and 43 normal controls were obtained by time-resolved fluoroimmunoassay technique. Results: FT 3 and FT 4 concentrations showed an obvious decrease 3 months after treatment, while sTSH and TRAb had remarkable high values, as TGA and TMA demonstrated a trend to increase. FT 3 , FT 4 and sTSH concentrations were close to control group 6 months after treatment, TRAb had a decline trend. All the six indexes approached to normal 18 months after treatment. Conclusion: It is of great of significance for the Graves' patients to accept the developmental observation of serum FT 3 , FT 4 , and sTSH, TRAb, TGA and TMA concentrations before and after 131 I therapy, which provides a great of positive information for therapy guiding, observation and prognosis. (authors)

  6. Experimental study on uranium alloys for hydrogen storage

    International Nuclear Information System (INIS)

    Deaconu, M.; Meleg, T.; Dinu, A.; Mihalache, M.; Ciuca, I.; Abrudeanu, M.

    2013-01-01

    The heaviest isotope of hydrogen is one of critically important elements in the field of fusion reactor technology. Conventionally, uranium metal is used for the storage of heavier isotopes of hydrogen (D and T). Under appropriate conditions, uranium absorbs hydrogen to form a stable UH 3 compound when exposed to molecular hydrogen at the temperature range of 300-500 O C at varied operating pressure below one atmosphere. However, hydriding-dehydriding on pure uranium disintegrates the specimen into fine powder. The powder is highly pyrophoric and has low heat conductivity, which makes it difficult to control the temperature, and has a high possibility of contamination Due to the powdering effect as hydrogen in uranium, alloying uranium with other metal looks promising for the use of hydrogen storage materials. This paper has the aim to study the hydriding properties of uranium alloys, including U-Ti U-Mo and U-Ni. The uranium alloys specimens were prepared by melting the constituent elements by means of simultaneous measurements of thermo-gravimetric and differential thermal analyses (TGA-DTA) and studied in as cast condition as hydrogen storage materials. Then samples were thermally treated under constant flow of hydrogen, at various temperatures between 573-973 0 K. The structural and absorption properties of the products obtained were examined by thermo-gravimetric analysis (TG), X-ray diffraction (XRD) and scanning electron microscopy (SEM). They slowly reacted with hydrogen to form the ternary hydride and the hydrogenated samples mainly consisted of the pursued ternary hydride bat contained also U or UO 2 and some transient phase. (authors)

  7. Significance of changes of serum FT3, FT4, s-TSH, TGA, TPO-Ab levels in patients with non-Graves' hyperthyroidism and Graves' disease

    International Nuclear Information System (INIS)

    Zhang Lindi; Xu Changde; Xu Huogen; Wang Wei; Zhang Jie; Nie Shufen; Gu Zhenqi; Zeng Jihua

    2006-01-01

    Objective: To investigate the clinical significance of the changes of thyroid-related hormones (FT 3 , FT 4 , s-TSH, TGA, TPO-Ab) levels in patients with Graves' and non-Graves' hyperthyroidism. Methods: Serum FT 3 , FT 4 , TGA, TPO-Ab (with RIA) and s-TSH (with IRMA) were determined in 43 patients with non-Graves' hyperthyroidism, 29 patients with Graves' disease and 40 controls. Results: In both groups of hyperthyroid patients, the serum levels of FT 3 (15.01 ± 11.01 pg/ml in the non - Graves' group and 15.23 ± 9.57pg/ml in the Graves' group), FT 4 (38.30 ± 19.82, 38.87 ± 17.39pg/ml), TGA(33.89 ± 22. 43%, 49.72 ± 20.55% ) and TPO-Ab (1319.24 ± 1037.78, 2023.24 ± 621.00IU/ml) were significantly higher than those (FT 3 , 6.76 ± 2.01pg/ml, FT 4 16.16 ± 2.58pg/ml, TGA 6.76 ± 2.01%, TPO-Ab 0.01 ± 0.01IU/ml) in the controls (all P 3 , FT 4 and s-TSH levels in both groups were not significantly different from each other. Conclusion: In this study, serum TGA and TPO -Ab levels were lower in patients with non-Graves' hyperthyroidism than those in patients with Graves' disease. (authors)

  8. Influence of rank and macerals on the burnout behaviour of pulverized Indian coal

    Energy Technology Data Exchange (ETDEWEB)

    Choudhury, Nandita; Biswas, S.; Sarkar, P.; Kumar, Manish; Mukherjee, A.; Choudhury, A. [Central Institute of Mining and Fuel Research, Digwadih Campus (Formerly Central Fuel Research Institute), P.O. FRI, Dhanbad-828 108, Jharkhand (India); Ghosal, Sujit; Mitra, Tandra [Jadavpur University, Kolkata-700 032, West Bengal (India)

    2008-04-03

    The combustion behaviour of coal is significantly influenced by its rank and maceral and microlithotype compositions. Different macerals, due to their distinct and unique physical properties and chemical makeup, have different burning characteristics. This paper deals with the burning behaviour of coals of Indian origin by thermo gravimetric analysis (TGA) and in drop tube furnace (DTF) with particular emphasis on the role of macerals and their associations. Four coals of different rank and petrographic makeup, along with their two density fractions, with enriched vitrinite and inertinites, respectively,were studied in both TGA and DTF. The burnout behaviour was estimated from the chemical analyses of the char samples collected from the DTF. The burning characteristics of one of the coals deviate from the trend expected with the variations of rank. The behaviour of the density fractions in DTF was found to be different from that observed in TGA analyses. An attempt has been made to correlate the burnout with the petrographic macerals and microlithotypes present in the coals. The morphology of the residual chars indicates the contributions of the inertinites towards the formation of cenospheres and network types of reactive chars. The superior burning behaviour of the higher density inertinite-rich fractions over the raw coals and also some vitrinite-rich fractions indicate the better reactivity of the inertinites towards combustion. (author)

  9. Experimental and computational investigation of adsorption performance of TC-5A and PSA-5A for manned spacecraft

    Directory of Open Access Journals (Sweden)

    Liu Meng

    2015-12-01

    Full Text Available Two kinds of molecular sieve materials, TC-5A and PSA-5A, were produced to satisfy with special requirement of manned space flight. Their CO2 adsorption performances were investigated and compared through two experiments, the thermo gravimetric analysis (TGA experiment and packed bed column experiment. Besides, some kinetic equations were compared according to the TGA experimental data, and their errors were analyzed. Finally, the classic linear driving force (LDF model is improved to the new Avrami’s model, and two models are analyzed based on the packed bed data. The TGA data shows that the CO2 loading has an approximately linear relationship with the CO2 concentration, and the best fit adsorption temperature range is from 283 to 303 K. The packed bed column results show that water vapor in air can affect the CO2 adsorption performance badly. The new Avrami’s model is proved more suitable to reflect the complex adsorption mechanism for two molecular sieves. The materials are proved having much better adsorption capacity than the other adsorbents with room temperature and low CO2 concentration (⩽1.0% in volume, and they can meet the aerospace requirements. This work will benefit the optimal design and simulation of the air revitalization (AR system for Chinese manned spacecraft.

  10. Clinical significance of combined determination of serum TPO-Ab and TGA levels and T lymphocyte subsets in patients with autoimmune thyroid disease (AITD)

    International Nuclear Information System (INIS)

    Zhang Jialin; Chen Daqiang; Li Ming; Xiao Yunzhen

    2007-01-01

    Objective: To investigate the possible relationship between serum thyroglobulin antibody, thyroid peroxidase antibody levels and the development of AITD. Methods: Thyroid peroxidase antibody (TPO-Ab) level was determined with electrochemilu-minescence assay, the thyroglobulin antibody (TGA) was detected by radiolmmunoassay and peripheral T-cells subsets were examined with monoclonal antibody technic in 87 patients with hyperthyroidism, 83 patients with hypothyroidism and 80 controls. Results: The thyroid peroxidase antibody and thyroglobulin antibody levels in AITD patients (including both hyper and hypothyroid patients) were significantly higher than those in the controls (P<0.01). Conclusion: It is proposed that increase of TPO-Ab and TGA is the cause of the development of AITD. (authors)

  11. Thermodynamic study of ibuprofen by adiabatic calorimetry and thermal analysis

    International Nuclear Information System (INIS)

    Xu Fen; Sun Lixian; Tan Zhicheng; Liang Jianguo; Li Ruilian

    2004-01-01

    Molar heat capacities of ibuprofen were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 80 to 400 K. The polynomial functions of C p,m (J K -1 mol -1 ) versus T were established on the heat capacity measurements by means of the least fitting square method. The functions are as follows: for solid ibuprofen, at the temperature range of 79.105 K≤T≤333.297 K, C p,m =144.27+77.046X+3.5171X 2 +10.925X 3 +11.224X 4 , where X=(T-206.201)/127.096; for liquid ibuprofen, at the temperature range of 353.406 K≤T≤378.785 K, C p,m =325.79+8.9696X-1.6073X 2 -1.5145X 3 , where X=(T-366.095)/12.690. A fusion transition at T=348.02 K was found from the C p -T curve. The molar enthalpy and entropy of the fusion transition were determined to be 26.65 kJ mol -1 and 76.58 J mol -1 K -1 , respectively. The thermodynamic functions on the base of the reference temperature of 298.15 K, (H T -H 298.15 ) and (S T -S 298.15 ), were derived. Thermal characteristic of ibuprofen was studied by thermo-gravimetric analysis (TG-DTG) and differential scanning calorimeter (DSC). The temperature of fusion, the molar enthalpy and entropy of fusion obtained by DSC were well consistent with those obtained by adiabatic calorimeter. The evaporation process of ibuprofen was investigated further by TG and DTG, and the activation energy of the evaporation process was determined to be 80.3±1.4 kJ mol -1

  12. Application of lag-k autocorrelation coefficient and the TGA signals approach to detecting and quantifying adulterations of extra virgin olive oil with inferior edible oils

    Energy Technology Data Exchange (ETDEWEB)

    Torrecilla, Jose S., E-mail: jstorre@quim.ucm.es [Department of Chemical Engineering, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid (Spain); Garcia, Julian; Garcia, Silvia; Rodriguez, Francisco [Department of Chemical Engineering, Faculty of Chemistry, University Complutense of Madrid, 28040 Madrid (Spain)

    2011-03-04

    The combination of lag-k autocorrelation coefficients (LCCs) and thermogravimetric analyzer (TGA) equipment is defined here as a tool to detect and quantify adulterations of extra virgin olive oil (EVOO) with refined olive (ROO), refined olive pomace (ROPO), sunflower (SO) or corn (CO) oils, when the adulterating agents concentration are less than 14%. The LCC is calculated from TGA scans of adulterated EVOO samples. Then, the standardized skewness of this coefficient has been applied to classify pure and adulterated samples of EVOO. In addition, this chaotic parameter has also been used to quantify the concentration of adulterant agents, by using successful linear correlation of LCCs and ROO, ROPO, SO or CO in 462 EVOO adulterated samples. In the case of detection, more than 82% of adulterated samples have been correctly classified. In the case of quantification of adulterant concentration, by an external validation process, the LCC/TGA approach estimates the adulterant agents concentration with a mean correlation coefficient (estimated versus real adulterant agent concentration) greater than 0.90 and a mean square error less than 4.9%.

  13. Application of lag-k autocorrelation coefficient and the TGA signals approach to detecting and quantifying adulterations of extra virgin olive oil with inferior edible oils

    International Nuclear Information System (INIS)

    Torrecilla, Jose S.; Garcia, Julian; Garcia, Silvia; Rodriguez, Francisco

    2011-01-01

    The combination of lag-k autocorrelation coefficients (LCCs) and thermogravimetric analyzer (TGA) equipment is defined here as a tool to detect and quantify adulterations of extra virgin olive oil (EVOO) with refined olive (ROO), refined olive pomace (ROPO), sunflower (SO) or corn (CO) oils, when the adulterating agents concentration are less than 14%. The LCC is calculated from TGA scans of adulterated EVOO samples. Then, the standardized skewness of this coefficient has been applied to classify pure and adulterated samples of EVOO. In addition, this chaotic parameter has also been used to quantify the concentration of adulterant agents, by using successful linear correlation of LCCs and ROO, ROPO, SO or CO in 462 EVOO adulterated samples. In the case of detection, more than 82% of adulterated samples have been correctly classified. In the case of quantification of adulterant concentration, by an external validation process, the LCC/TGA approach estimates the adulterant agents concentration with a mean correlation coefficient (estimated versus real adulterant agent concentration) greater than 0.90 and a mean square error less than 4.9%.

  14. Alteration of skin hydration and its barrier function by vehicle and permeation enhancers: a study using TGA, FTIR, TEWL and drug permeation as markers.

    Science.gov (United States)

    Shah, D K; Khandavilli, S; Panchagnula, R

    2008-09-01

    Vehicles and permeation enhancers (PEs) used in transdermal drug delivery (TDD) of a drug can affect skin hydration, integrity and permeation of the solute administered. This investigation was designed to study the effect of the most commonly used vehicles and PEs on rat skin hydration, barrier function and permeation of an amphiphilic drug, imipramine hydrochloride (IMH). An array of well-established techniques were used to confirm the findings of the study. Thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy were used to determine changes in skin hydration. Alteration of the stratum corneum (SC) structure was investigated using FTIR studies. To monitor the barrier function alteration, transepidermal water loss (TEWL) measurement and permeation studies were performed. Our findings indicate that with hydration, there was an increase in the bound water content of the skin, and pseudoequilibrium of hydration (a drastic decrease in hydration rate) was achieved at around 12 h. Hydration increased the ratio between amide-I and amide-II peaks in FTIR and reduced the C-H stretching peak area. Both propylene glycol (PG) and ethanol (EtOH) dehydrated skin, with the latter showing a predominant effect. Furthermore, it was confirmed that PG and EtOH decreased the bound water content due to alteration in the protein domains and extraction of SC lipids, respectively. The effect of hydration on the SC was found to be similar to that reported for temperature. Permeation studies revealed that the dehydration caused by vehicles decreased IMH flux, whereas the flux was enhanced by PEs. The role of partition was predominant for the permeation of IMH through dehydrated skin. A synergistic effect was observed for PG and menthol in the enhancement of IMH. Further findings provided strong evidence that PG affects protein domains and EtOH extracts lipids from the bilayer. Both PG and EtOH, with or without PEs, increased TEWL. Initial TEWL was well

  15. Engineering of Highly Susceptible Paramagnetic Nanostructures of Gd2S3:Eu3+: Potentially an Efficient Material for Room Temperature Gas Sensing Applications

    Directory of Open Access Journals (Sweden)

    Muhammed M. Radhi

    2010-11-01

    Full Text Available This research papers throws light into the compositional, morphological and structural properties of novel nanoparticles of Gd2S3:Eu3+ synthesized by a simple co-precipitation technique. Furthermore, we also prognosticate that this material could be useful for gas sensing applications at room temperature. Nanostructures formulation by this method resulted in the formation of orthorhombic crystal structure with primitive lattice having space group Pnma. The material characterizations are performed using X-ray diffraction (XRD, energy dispersive X-ray analysis (EDX, thermo-gravimetric analysis/differential thermal analysis (TGA/DTA and transmission electron microscope (TEM. The calculated crystallite sizes are ~ 2-5 nm and are in well accordance with the HRTEM results. EDX result confirms the presence and homogeneous distribution of Gd and Eu throughout the nanoparticle. The prepared nanoparticles exhibit strong paramagnetic nature with paramagnetic term, susceptibility c = 8.2 ´ 10-5 emg/g Gauss. TGA/DTA analysis shows 27 % weight loss with rise in temperature. The gas sensing capability of the prepared Gd2S3:Eu3+ magnetic nanoparticles are investigated using the amperometric method. These nanoparticles show good I-V characteristics with ideal semiconducting nature at room temperature with and without ammonia dose. The observed room temperature sensitivity with increasing dose of ammonia indicates applicability of Gd2S3 nanoparticles as room temperature ammonia sensors.

  16. Studies on mechanical, thermal and dynamic mechanical properties of untreated (raw) and treated coconut sheath fiber reinforced epoxy composites

    International Nuclear Information System (INIS)

    Suresh Kumar, S.M.; Duraibabu, D.; Subramanian, K.

    2014-01-01

    Highlights: • UTCSE and TCSE composites have been fabricated by compression molding technique. • The prepared specimens were characterized by FTIR, DMA, TGA and SEM techniques. • TCSE composite showed higher mechanical properties compared to UTCSE composite. • DMA showed that TCSE composite exhibited higher storage modulus than UTCSE composite. • TCSE composite showed higher thermal stability than UTCSE composite. - Abstract: The untreated (raw) coconut sheath fiber reinforced epoxy (UTCSE) composite and treated coconut sheath fiber reinforced epoxy (TCSE) composite have been fabricated using hand layup followed by compression molding technique. The prepared specimens were characterized by Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM) techniques. The prepared specimens are cut as per ASTM Standards to measure tensile, flexural and impact strengths by using universal testing machine and izod impact tester respectively. The treated coconut sheath fiber reinforced epoxy composite (TCSE) posses higher mechanical strength and thermal stability compared to untreated (raw) coconut sheath fiber reinforced epoxy composite (UTCSE). In the SEM fracture analysis, TCSE composite showed better fiber–matrix bonding and absence of voids compared to UTCSE composite

  17. Climate to measure. Facility management for Universal Music at Berlin; Klima nach Mass. TGA-Planung fuer Universal Music in Berlin

    Energy Technology Data Exchange (ETDEWEB)

    McLead, E.A.

    2002-07-01

    Designing and constructing the technical facilities for a historical building like the 'Spreespeicher' in Berlin is a difficult but interesting task. The building is owned by Universal Music. Each department has its own office structure, and all offices and structures were integrated in a functional overall concept by the planners of Happold Ingenieure. [German] Klima, Lueftung und Elektroinstallation fuer ein historisches Gebaeude wie den Berliner Spreespeicher zu entwickeln, ist eine schwierige, aber reizvolle Aufgabe. Besonders, wenn der Nutzer Universal Music heisst: Jede Abteilung besitzt ihre eigene Buerostruktur, und alle mussten die TGA-Planer von Happold Ingenieure in ein funktionierendes Gesamtkonzept integrieren. (orig.)

  18. Features of the incorporation of single and double based powders within emulsion explosives

    Science.gov (United States)

    Ribeiro, J. B.; Mendes, R.; Tavares, B.; Louro, C.

    2014-05-01

    In this work, features of the thermal and detonation behaviour of compositions resulting from the mixture of single and double based powders within ammonium nitrate based emulsion explosives are shown. Those features are portrayed through results of thermodynamic-equilibrium calculations of the detonation velocity, the chemical compatibility assessment through differential thermal analysis [DTA] and thermo gravimetric analysis [TGA], the experimental determination of the detonation velocity and a comparative evaluation of the shock sensitivity using a modified version of the "gap-test". DTA/TGA results for the compositions and for the individual components overlap until the beginning of the thermal decomposition which is an indication of the absence of formation of any new chemical species and so of the compatibility of the components of the compositions. After the beginning of the thermal decomposition it can be seen that the rate of mass loss is much higher for the compositions with powder than for the one with sole emulsion explosive. Both, theoretical and experimental, values of the detonation velocity have been shown to be higher for the powdered compositions than for the sole emulsion explosive. Shock sensitivity assessments have ended-up with a slightly bigger sensitivity for the compositions with double based powder when compared to the single based compositions or to the sole emulsion.

  19. Features of the incorporation of single and double based powders within emulsion explosives

    International Nuclear Information System (INIS)

    Ribeiro, J B; Mendes, R; Tavares, B; Louro, C

    2014-01-01

    In this work, features of the thermal and detonation behaviour of compositions resulting from the mixture of single and double based powders within ammonium nitrate based emulsion explosives are shown. Those features are portrayed through results of thermodynamic-equilibrium calculations of the detonation velocity, the chemical compatibility assessment through differential thermal analysis [DTA] and thermo gravimetric analysis [TGA], the experimental determination of the detonation velocity and a comparative evaluation of the shock sensitivity using a modified version of the g ap-test . DTA/TGA results for the compositions and for the individual components overlap until the beginning of the thermal decomposition which is an indication of the absence of formation of any new chemical species and so of the compatibility of the components of the compositions. After the beginning of the thermal decomposition it can be seen that the rate of mass loss is much higher for the compositions with powder than for the one with sole emulsion explosive. Both, theoretical and experimental, values of the detonation velocity have been shown to be higher for the powdered compositions than for the sole emulsion explosive. Shock sensitivity assessments have ended-up with a slightly bigger sensitivity for the compositions with double based powder when compared to the single based compositions or to the sole emulsion.

  20. Promising SiC support for Pd catalyst in selective hydrogenation of acetylene to ethylene

    Science.gov (United States)

    Guo, Zhanglong; Liu, Yuefeng; Liu, Yan; Chu, Wei

    2018-06-01

    In this study, SiC supported Pd nanoparticles were found to be an efficient catalyst in acetylene selective hydrogenation reaction. The ethylene selectivity can be about 20% higher than that on Pd/TiO2 catalyst at the same acetylene conversion at 90%. Moreover, Pd/SiC catalyst showed a stable catalytic life at 65 °C with 80% ethylene selectivity. With the detailed characterization using temperature-programmed reduction (H2-TPR), powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), N2 adsorption/desorption analysis, CO-chemisorption and thermo-gravimetric analysis (TGA), it was found that SiC owns a lower surface area (22.9 m2/g) and a broad distribution of meso-/macro-porosity (from 5 to 65 nm), which enhanced the mass transfer during the chemical process at high reaction rate and decreased the residence time of ethylene on catalyst surface. Importantly, SiC support has the high thermal conductivity, which favored the rapid temperature homogenization through the catalyst bed and inhabited the over-hydrogenation of acetylene. The surface electronic density of Pd on Pd/SiC catalyst was higher than that on Pd/TiO2, which could promote desorption of ethylene from surface of the catalyst. TGA results confirmed a much less coke deposition on Pd/SiC catalyst.

  1. Effect of humic substances on phosphorus removal by struvite precipitation.

    Science.gov (United States)

    Zhou, Zhen; Hu, Dalong; Ren, Weichao; Zhao, Yuzeng; Jiang, Lu-Man; Wang, Luochun

    2015-12-01

    Humic substances (HS) are a major fraction of dissolved organic matters in wastewater. The effect of HS on phosphorus removal by struvite precipitation was investigated using synthetic wastewater under different initial pH values, Mg/P molar ratios and HS concentrations. The composition, morphology and thermal properties of harvested precipitates were analyzed by X-ray diffraction (XRD), scanning electron microscope (SEM) and thermo-gravimetric analysis (TGA), respectively. It showed that inhibition effect of HS reached its maximum value of 48.9% at pH 8.0, and decreased to below 10% at pH>9.0. The increase of Mg/P ratio enhanced phosphorus removal efficiency, and thus reduced the influence of HS on struvite precipitation. At pH 9.0, the inhibitory effect of initial HS concentration matched the modified Monod model with half maximum inhibition concentration of 356mgL(-1), and 29% HS was removed in conjunction with struvite crystallisation. XRD analysis revealed that the crystal form of struvite precipitates was changed in the presence of HS. The morphology of harvested struvite was transformed from prismatic to pyramid owing to the coprecipitation of HS on crystal surface. TGA results revealed that the presence of HS could compromise struvite purity. Copyright © 2015 Elsevier Ltd. All rights reserved.

  2. Effect of functionalization of graphene nanoplatelets on the mechanical response of graphene/epoxy composites

    International Nuclear Information System (INIS)

    Ahmadi-Moghadam, B.; Sharafimasooleh, M.; Shadlou, S.; Taheri, F.

    2015-01-01

    Highlights: • A new functionalization strategy for GNPs, using trimethoxysilane is introduced. • Bond quality between GNP and silane agent is verified by the Raman spect. and TGA. • The functionaliz’n effects on mechanical properties of GNP/epoxy were investigated. • The functionaliz’n effects on the fracture mechanisms of GNP/epoxy investigated. • GNP dispersion quality is also evaluated using SEM micrographs and XRD. - Abstract: This study introduces a new strategy for functionalizing graphene nanoplatelets (GNPs) by bonding a silane agent to its structure. In order to evaluate the efficacy of the proposed method, epoxy resin specimens reinforced with silane modified GNPs (G-Si) are prepared at different weight contents of nanoparticles along with three other types of GNPs (unmodified GNP, graphene oxide GNP [GO], and amino functionalized GNP [G-NH 2 ]). The nanocomposites’ mechanical properties, such as the elastic modulus, ultimate strength, modulus of toughness and fracture toughness are evaluated and compared for different types of functionalization. Raman spectroscopy, thermo-gravimetric analysis (TGA) and Fourier transform infrared spectroscopy (FTIR) are employed to characterize the chemical and structural changes of the functionalized GNPs. The results show that nanocomposites containing G-Si and G-NH 2 provide the best results for most of the mentioned properties. The functionalization of GNPs gives the most promising results for fracture toughness of epoxy, showing an 82% increase, and scanning electron microscopy (SEM) micrographs and XRD analysis reveal that an improved dispersion status is obtained by GNP functionalization

  3. Synthesis, characterization and behaviour to gamma radiation of the bis-L-alaninato-copper (II)

    International Nuclear Information System (INIS)

    Passos, B.F.T.

    1985-01-01

    The behaviour of coordinated compound obtained from the copper (II) and the L-(+)- alanine to gamma radiation was determined. A study of synthesis and characterization of this complex was made with elementary analysis, ultraviolet and visible electronic spectroscopy, infrared vibrational spectroscopy, proton magnetic resonance spectroscopy and thermo-gravimetric analysis. (C.G.C.)

  4. Shortened carbon nanotubes and their influence on the electrical properties of polymer nanocomposites

    NARCIS (Netherlands)

    Inam, F.; Reece, M.J.; Peijs, A.A.J.M.

    2012-01-01

    Multi-wall carbon nanotubes of medium length (mCNTs) were aggressively tip-ultrasonicated to produce shortened and damaged carbon nanotubes (xCNTs). High-resolution electron microscopic analysis was performed to measure the dimensions of carbon nanotubes (CNTs). Thermo-gravimetric analysis and Raman

  5. Features of the Valorization of Single and Double Based Powders for Codetonation in Emulsion Explosives

    Science.gov (United States)

    Ribeiro, Jose; Mendes, Ricardo; Tavares, Bruno; Louro, Cristina

    2013-06-01

    In this work, features of the thermal and detonation behavior of compositions resulting from the mixture of single and double based gun powder within ammonium nitrate (AN) based emulsion explosives are shown. That includes results of thermodynamic-equilibrium calculations of the detonation velocity, the chemical compatibility assessment through differential scanning calorimetry [DSC] and thermo gravimetric analysis [TGA], the experimental determination of the detonation velocity and a comparative evaluation of the shock sensitivity using a modified version of the ``gap-test''. DSC/TGA results for the compositions and for the individual components overlap until the beginning of the thermal decomposition which is an indication of the absence of formation of any new chemical specimens and so of the capability of the composition components. After the beginning of the thermal decomposition it can be seen that the rate of mass loss is much higher for the compositions with gun powder than for the sole emulsion explosive. Both, theoretical and experimental, values of the detonation velocity have shown to be higher for the powdered compositions than for the pure emulsion explosive. Shock sensitivity assessment have ended-up with a slightly bigger sensitivity for the compositions with double based gun powder when compared to the single based compositions or to the pure emulsion.

  6. Synthesis of nanoporous carbohydrate metal-organic framework and encapsulation of acetaldehyde

    Science.gov (United States)

    Al-Ghamdi, Saleh; Kathuria, Ajay; Abiad, Mohamad; Auras, Rafael

    2016-10-01

    Gamma cyclodextrin (γ-CD) metal organic frameworks (CDMOFs) were synthesized by coordinating γ-CDs with potassium hydroxide (KOH), referred hereafter as CDMOF-a, and potassium benzoate (C7H5KO2), denoted as CDMOF-b. The obtained CDMOF structures were characterized using nitrogen sorption isotherm, thermo-gravimetric analysis (TGA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). High surface areas were achieved by the γ-CD based MOF structures where the Langmuir specific surface areas (SSA) of CDMOF-a and CDMOF-b were determined as 1376 m2 g-1 and 607 m2 g-1; respectively. The dehydrated CDMOF structures demonstrated good thermal stability up to 250 °C as observed by the TGA studies. XRD results for CDMOF-a and CDMOF-b reveal a body centered-cubic (BCC) and trigonal crystal system; respectively. Due to its accessible porous structure and high surface area, acetaldehyde was successfully encapsulated in CDMOF-b. During the release kinetic studies, we observed peak release of 53 μg of acetaldehyde per g of CDMOF-b, which was 100 times greater than previously reported encapsulation in β-CD. However, aldol condensation reaction occurred during encapsulation of acetaldehyde into CDMOF-a. This research work demonstrates the potential to encapsulate volatile organic compounds in CDMOF-b, and their associated release for applications including food, pharmaceuticals and packaging.

  7. Physicochemical characterization of chitosan/nylon6/polyurethane foam chemically cross-linked ternary blends.

    Science.gov (United States)

    Jayakumar, S; Sudha, P N

    2013-03-15

    Chitosan/nylon6/polyurethane foam (CS/Ny6/PUF) ternary blend was prepared and chemically cross-linked with glutaraldehyde. Structural, thermal and morphological studies were performed for the prepared ternary blends. Characterizations of the ternary blends were investigated by Fourier transform infrared spectroscopy (FTIR), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and scanning electron microscope (SEM). The FTIR results showed that the strong intermolecular hydrogen bonds took place between CS, Ny6 and PUF. TGA and DSC studies reveal that the thermal stability of the blend is enhanced by glutaraldehyde as crosslinking agent. Results of XRD indicated that the relative crystalline of pure CS film was reduced when the polymeric network was reticulated by glutaraldehyde. Finally, the results of scanning electron microscopy (SEM) indicated that the morphology of the blend is rough and heterogeneous, further it confirms the interaction between the functional groups of the blend components. Copyright © 2012 Elsevier B.V. All rights reserved.

  8. Suitability of Sr{sub 0.5}Ba{sub 0.5-x}Ce{sub x}Fe{sub 12-y}Ni{sub y}O{sub 19} co-precipitated nanomaterials for inductor applications

    Energy Technology Data Exchange (ETDEWEB)

    Iqbal, Muhammad Javed, E-mail: mjiqauchem@yahoo.co [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Farooq, Saima [Surface and Solid State Chemistry Laboratory, Department of Chemistry, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

    2010-03-18

    The present investigation deals with the synthesis and characterization of Ce-Ni ions substituted nanocrystalline strontium-barium hexaferrites (Sr{sub 0.5}Ba{sub 0.5}Fe{sub 12}O{sub 19}) by the chemical co-precipitation method, with focus on the optimization of annealing temperature for the hexagonal phase development. The synthesis involves co-precipitation of aqueous solutions of water-soluble salts of strontium, barium and iron, at pH 9 using an ammonium hydroxide solution as a precipitating agent. The optimum temperature of annealing, necessary for the hexagonal phase development, is determined on the basis of thermo-gravimetric analysis (TGA). The co-precipitate is annealed at a temperature of 1323 K for 6 h, to produce a single magnetoplumbite phase of Sr-Ba hexaferrites, with the corresponding average crystallite size ranging from 36 to 48 nm. Observed changes in the lattice structure determined by the powder X-ray diffraction (XRD) studies are not in contradiction with the results of TGA. DC-electrical resistivity increases from 1.8 x 10{sup 10} to 12.5 x 10{sup 10} {Omega} cm, whereas the drift mobility, dielectric constant and dielectric loss tangent decrease with increasing the Ce-Ni content of the samples. Material of above-mentioned characteristics is considered to be suitable for applications in the microwave and surface mount devices (SMD) for fabricating the multilayer chip inductors (MLCI).

  9. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    Science.gov (United States)

    Totemeier, Terry C.; Pahl, Robert G.; Frank, Steven M.

    The oxidation behavior of hydride-bearing uranium metal corrosion products from Zero Power Physics Reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2, Ar-9%O 2, and Ar-20%O 2. Ignition of corrosion product samples from two moderately corroded plates was observed between 125°C and 150°C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride.

  10. Oxidation kinetics of hydride-bearing uranium metal corrosion products

    International Nuclear Information System (INIS)

    Totemeier, T.C.; Pahl, R.G.; Frank, S.M.

    1998-01-01

    The oxidation behavior of hydride-bearing uranium metal corrosion products from zero power physics reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2 , Ar-9%O 2 , and Ar-20%O 2 . Ignition of corrosion product samples from two moderately corroded plates was observed between 125 C and 150 C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride. (orig.)

  11. Nanowires of silver-polyaniline nanocomposite synthesized via in situ polymerization and its novel functionality as an antibacterial agent.

    Science.gov (United States)

    Tamboli, Mohaseen S; Kulkarni, Milind V; Patil, Rajendra H; Gade, Wasudev N; Navale, Shalaka C; Kale, Bharat B

    2012-04-01

    Silver-polyaniline (Ag-PANI) nanocomposite was synthesized by in situ polymerization method using ammonium persulfate (APS) as an oxidizing agent in the presence of dodecylbenzene sulfonic acid (DBSA) and silver nitrate (AgNO(3)). The as synthesized Ag-PANI nanocomposite was characterized by using different analytical techniques such as UV-visible (UV-vis) and Fourier transform Infrared spectroscopy (FT-IR), field emission scanning electron microscopy (FE-SEM), thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and transmission electron microscopy (TEM). UV-visible spectra of the synthesized nanocomposite showed a sharp peak at ~420 nm corresponding to the surface plasmon resonance (SPR) of the silver nanoparticles (AgNPs) embedded in the polymer matrix which is overlapped by the polaronic peak of polyaniline appearing at that wavelength. Nanowires of Ag-PANI nanocomposite with diameter 50-70 nm were observed in FE-SEM and TEM. TGA has indicated an enhanced thermal stability of nanocomposite as compared to that of pure polymer. The Ag-PANI nanocomposite has shown an antibacterial activity against model organisms, a gram positive Bacillus subtilis NCIM 6633 in Mueller-Hinton (MH) medium, which is hitherto unattempted. The Ag-PANI nanocomposite with monodispersed AgNPs is considered to have potential applications in sensors, catalysis, batteries and electronic devices. Copyright © 2011 Elsevier B.V. All rights reserved.

  12. Hydrothermal Carbonization of Spent Osmotic Solution (SOS Generated from Osmotic Dehydration of Blueberries

    Directory of Open Access Journals (Sweden)

    Kaushlendra Singh

    2014-09-01

    Full Text Available Hydrothermal carbonization of spent osmotic solution (SOS, a waste generated from osmotic dehydration of fruits, has the potential of transformation into hydrochars, a value-added product, while reducing cost and overall greenhouse gas emissions associated with waste disposal. Osmotic solution (OS and spent osmotic solution (SOS generated from the osmotic dehydration of blueberries were compared for their thermo-chemical decomposition behavior and hydrothermal carbonization. OS and SOS samples were characterized for total solids, elemental composition, and thermo-gravimetric analysis (TGA. In addition, hydrothermal carbonization was performed at 250 °C and for 30 min to produce hydrochars. The hydrochars were characterized for elemental composition, Brunauer-Emmett-Teller (BET surface area, particle shape and surface morphology. TGA results show that the SOS sample loses more weight in the lower temperature range than the OS sample. Both samples produced, approximately, 40%–42% (wet-feed basis hydrochar during hydrothermal carbonization but with different properties. The OS sample produced hydrochar, which had spherical particles of 1.79 ± 1.30 μm diameter with a very smooth surface. In contrast, the SOS sample produced hydrochar with no definite particle shape but with a raspberry-like surface.

  13. Conversion of glycerol to polyglycerol over waste duck-bones as a catalyst in solvent free etherification process

    Science.gov (United States)

    Ayoub, Muhammad; Sufian, Suriati; Mekuria Hailegiorgis, Sintayehu; Ullah, Sami; Uemura, Yoshimitsu

    2017-08-01

    The alkaline catalyst derived from the duck-bones was used for conversion of glycerol to polyglycerol via solvent free etherification process. The physicochemical properties of prepared materials were duck-bones were systematically investigated as a catalyst by latest techniques of Thermo gravimetric analysis (TGA), X-ray diffraction (XRD), and Brunauer-Emmett-Teller (BET) surface properties. TGA showed different trends of duck-bones decomposition from room temperature to 1000C. XRD pattern showed a clear and sharp peaks of a crystalline phase of CaO. The activity of the catalysts was in line with the basic amount of the strong base sites, surface area, and crystalline phase in the catalysts. The prepared catalyst derived from duck-bones provided high activity (99 %) for glycerol conversion and around 68 % yield for polyglycerol production. These ample wastes of duck-bones have good potential to be used as polyglycerol production catalysts due to have high quantity of Ca compare to other types of bones like cow, chicken and fish bones.

  14. Study of HKUST (Copper benzene-1,3,5-tricarboxylate, Cu-BTC MOF)-1 metal organic frameworks for CH4 adsorption: An experimental Investigation with GCMC (grand canonical Monte-carlo) simulation

    International Nuclear Information System (INIS)

    Sun, Baichuan; Kayal, Sibnath; Chakraborty, Anutosh

    2014-01-01

    We have measured the methane uptakes on HKUST (Copper benzene-1,3,5-tricarboxylate, Cu-BTC MOF)-1 MOF (metal organic framework) for the temperatures ranging from 120 K to 300 K and pressures up to 10 bar. The experimentally measured HKUST-1 + CH 4 isotherms data are compared with uptakes of various adsorbents and methane systems. We have also simulated the methane uptakes and its density distribution on HKUST-1 employing GCMC (grand canonical Monte-carlo) simulation and compare with experimental data. In this article, we also present an extensive study on characterization and property evaluation of HKUST-1 MOF for CH 4 adsorption characteristics employing XRD (X-ray diffraction), SEM (scanning electron microscope) and TGA (thermo gravimetric analysis). Employing GCMC and the thermodynamic property fields of HKUST-1 + CH 4 system, the isosteric heat of adsorption (Q st ) is calculated and Q st is presented in a T-s (temperature-entropy) diagram. - Highlights: • Characterization of HKUST-1 MOFs by XRD, SEM, N 2 adsorption and TGA. • Measurement of CH 4 uptakes on HKUST-1 by volumetric methods. • GCMC simulation of methane uptakes and its density distribution on HKUST-1. • Isosteric heat of adsorption in a T-s (temperature-entropy) diagram

  15. Study on the relationship between the magnitude of increase of serum TMA, TGA contents and the size of goiter in patients with Graves' disease after treatment with 131I

    International Nuclear Information System (INIS)

    Zheng Fang; Tan Qingling

    2009-01-01

    Objective: To study the relationship between changes of serum TMA, TGA levels and the size of goiter in patients with Graves' disease treated with 131 I. Methods: Serum TGA, TMA levels were measured with CLIA in 327 patients with Graves' disease both before and six months after 131 I treatment. These 327 patients were of three groups: Goiter I degree n=97, II degree n=128, III degree n=102. Results: In patients with I degree goiter,the serum TGA and TMA levels were only insignificantly increased after the 131 I treatment with an early hypothroidism rate of 21.44%. In patients with II degree goiter, the serum TGA and TMA levels were significantly increased after treatment (P 131 I. (authors)

  16. Assessment of Sediment Heavy Metals Pollution Using Screening Methods (XRF, TGA/MS, XRPD and Earthworms Bioassay)

    Science.gov (United States)

    Findoráková, Lenka; Šestinová, Ol'ga; Hančul'ák, Jozef; Fedorová, Erika; Zorkovská, Anna

    2016-10-01

    The aim of this study is focused on the use of screening methods (TG/DTA coupled with MS, XRF, AAS, XRPD and earthworm bioassay) for sediments pollution assessing by heavy metals (Cu, Zn, Pb, Hg) coming from the former mining workloads in the central Spis, Eastern Slovakia. The screening methods (XRF, AAS) indicated pollution of studied sediments by Cu, Zn, Pb, Hg. The earthworms Dendrobaena veneta caused in some studied samples decrease of heavy metals concentration after their 7 days’ exposure in sediments. The other screening methods such as thermal analysis and XRPD analysis, does not confirm the specifically changes in physicochemical properties comparing the properties before and after 7 days’ earthworm's exposure.

  17. Determination of the structure, morphology and complex refractive index in ZnO-nanopencils/P3HT hybrid structures

    CSIR Research Space (South Africa)

    Motaung, DE

    2012-08-01

    Full Text Available of the base of the flower-shapes. ZnO-NPs were incorporated into the nanomorphology of P3HT and two variations of P3HT:C60 and P3HT: PCBM blended films in order to facilitate charge separation and transport. Thermo-gravimetric analysis revealed that Zn...

  18. Study of magnetic properties of TGa6 with T = Ce, Pr, Nd, Tb, Ho, Dy and of solid solutions Ce(Ga1-x Alx)2

    International Nuclear Information System (INIS)

    Jerjini, M.

    1987-10-01

    At low temperature TGa 6 compounds are ordered with a Neel temperature of about 10 K. Magnetic structures are antiferromagnetic for T = Pr or Nd or modulated for T = Tb, Ho or Dy. Ce presents an abnormal behavior in CeGa 6 . Neutron inelastic scattering allows the determination of energy levels in the crystal field of cerium ion and evidences hybridation of 4f and valence electrons. Three magnetic transitions for T 6 . Study of CeGa 6 and solid solutions. Ce(Ga (1-x) Al x ) 2 shows that aluminium insertion reinforces the Kondo effect. For x = O.1 an incommensurable structure subsists at very low temperature. CeGa 2 is ordered with 3 magnetic structures. Magnetic moment is reduced with Al. The study of crystal field by neutron scattering shows that hybridation effects are more important for the compound with x = 0.1 [fr

  19. Decomposition kinetic and mechanism of syndiotactic polystyrene nanocomposites with MWCNTs and nanodiamonds studied by TGA and Py-GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Chrissafis, Konstantinos; Pavlidou, Eleni [Solid State Physics Section, Physics Department, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Macedonia (Greece); Vouvoudi, Evangelia [Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Macedonia (Greece); Bikiaris, Dimitrios, E-mail: dbic@chem.auth.gr [Laboratory of Polymer Chemistry and Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Macedonia (Greece)

    2014-05-01

    Graphical abstract: - Highlights: • Syndiotactic polystyrene nanocomposites containing MWCNTs and nanodiamonds were prepared for first time. • Addition of nanofillers causes a substantial improvement of sPS thermal stability. • From EGA and Py-GC/MS, it was found that sPS decomposes through a radical process. • The decomposition mechanism of sPS was not affected by the addition of nanoparticles. - Abstract: In the present work, syndiotactic polystyrene (sPS) based nanocomposites containing 3 wt% of multi-walled carbon nanotubes (MWCNTs) and nanodiamonds (NDs) were prepared using the melt-mixing technique. Transmission electron microscopy (TEM) micrographs verified a good dispersion of the nanoparticles in the polymeric matrix, which resulted in a slight improvement of the mechanical properties of the nanocomposites. The addition of MWCNTs promotes the formation of β-type crystals while in sPS and sPS/NDs α-type crystals are mainly formed. From the thermogravimetric analysis experiments a substantial enhancement of sPS thermal stability was found, caused by the addition of nanofillers, especially from NDs. The temperature corresponding to a mass loss of 0.5% was found 295 °C for sPS, 352.4 °C for sPS-MWCNTs and 370.7 °C for sPS-NDs nanocomposites. The analytical method of Py-GC/MS was also used for further characterization of the samples. The main chain fragments collected from sPS pyrolysis were styrene monomers, dimers and trimers, while the three pyrolization temperatures applied (390, 420 and 500 °C) indicated some variations in intensity of decomposition fragments. The decomposition temperature as well as the nanoparticle addition (NDs or MWCNTs) affected the intensity of the recorded fragments but did not induce a change on the decomposition mechanism of sPS.

  20. Thermogravimetric Analysis of Single-Wall Carbon Nanotubes

    Science.gov (United States)

    Arepalli, Sivram; Nikolaev, Pavel; Gorelik, Olga

    2010-01-01

    An improved protocol for thermogravimetric analysis (TGA) of samples of single-wall carbon nanotube (SWCNT) material has been developed to increase the degree of consistency among results so that meaningful comparisons can be made among different samples. This improved TGA protocol is suitable for incorporation into the protocol for characterization of carbon nanotube material. In most cases, TGA of carbon nanotube materials is performed in gas mixtures that contain oxygen at various concentrations. The improved protocol is summarized.

  1. Influence of surface modified nanoilmenite/amorphous silica composite particles on the thermal stability of cold galvanizing coating

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sabagh

    2018-03-01

    Full Text Available The present approach investigates the use of novel nanoilmenite/amorphous silica composite (NI/AS particles fabricated from ilmenite nanoparticles (FeTiO3 NPs and synthesized amorphous silica grains to improve thermal stability of the cold galvanizing coating. Transmission electron microscopic (TEM images demonstrated that both nanoilmenite and nanocomposite particles were of flaky-like nature and the average diameter of the particles is 20 nm. The lamellar shape of the nanocomposite and spherical nature of Zn-dust particles were illustrated by scanning electron microscopy (SEM micrographs. Different alkyd-based cold galvanizing coating formulations were modified using uniformly dispersing various amounts of the processed nanocomposite particles as a modifier to form some engineering nanocomposite coatings. Thermal stability of the nanocomposite and Zn-dust particles was determined by thermo-gravimetric analysis (TGA. From the obtained results it could be observed that the weight loss (% as a feature of the thermal stability in case of the nanocomposite particles was 2.9 compared to 85.9 for Zn-dust powder grains. Derivative thermo-gravimetric (DTG measurements were done under nitrogen atmosphere for the cured cold galvanizing coating samples heated from room temperature to 1000 °C. The obtained results revealed that the maximum decomposition temperature point in the third degradation step for 6% nanocomposite surface modified cured sample (CG-F was detected at 693 °C and was less value for unmodified conventional cold galvanizing coating (CG-A at 612 °C. The increase in thermal stability with increasing the concentration of nanocomposite particles could be mainly attributed to the interface surface interaction between the nanocomposite particles and alkyd resin matrix in which enhancing the inorganic-organic network stiffness by causing a reduction in the total free spaces and enhancement in the cross-linking density of the cured film

  2. Application to refrigerator plastics by mechanical recycling from polypropylene in waste-appliances

    International Nuclear Information System (INIS)

    Ha, Kyung Ho; Kim, Moon Saeng

    2012-01-01

    Highlights: → Polypropylene is mechanically recycled from waste-appliances. → Recycled polypropylene (RPP) is impact enhanced polypropylene with ethylene-propylene rubber (EPR). → Performance evaluation shows that RPP is applicable to refrigerator plastics. -- Abstract: For the application to refrigerator plastics by mechanical recycling from polypropylene (PP) in waste-appliances, it needs to identify the degradation and heterogeneity of recycled polypropylene (RPP). It is applicable the thermal analysis such as differential scanning calorimetry (DSC), thermo-gravimetric analysis (TGA), spectroscopic analysis such as Fourier Transform Infrared (FTIR) and morphological analysis such as scanning electronic microscope (SEM). The analysis results show that RPP from waste-appliances is the polyethylene (PE) and polypropylene (PP) copolymer enhanced impact property (Impact-PP) and it is possible to apply refrigerator plastics with good impact property at low temperature. Finally, the performance evaluation of RPP is estimated by Gel Permeation Chromatography (GPC) analysis and is performed by the various mechanical and physical testing methods. It shows that RPP has relatively high molecular weight and balanced properties with strength and toughness. It is expected that RPP by the mechanical recycling from waste-appliances will have about 50% cost-merit.

  3. Morphological Changes of Limestone Sorbent Particles during Carbonation/Calcination Looping Cycles in a Thermogravimetric Analyzer (TGA) and Reactivation with Steam

    KAUST Repository

    Wu, Y.

    2010-04-15

    Carbonation and calcination looping cycles were carried out on four limestones in a thermogravimetric analyzer (TGA). The CO2 carrying capacity of a limestone particle decays very quickly in the first 10 cycles, reducing to about 20% of its original uptake capacity after 10 cycles for the four limestones studied in this work, and it decreases further to 6-12% after 50 cycles. A new steam reactivation method was applied on the spent sorbent to recover the loss of reactivity. The steam reactivation of multi-cycled samples was conducted at atmospheric pressure. Steam reactivation for 5 min at 130 °C of particles that had undergone 10 cycles resulted in an immediate increase (by 45-60% points) in carrying capacity. The morphological changes of limestone particles during the cycling and steam reactivation were studied using both an optical microscope and scanning electron microscopy (SEM). The diameters of limestone particles shrank by about 2-7% after 10 carbonation/calcination cycles, and the particle diameters swelled significantly (12-22% increase) after steam reactivation. These size changes are important for studies of attrition and mathematical modeling of carbonation. © 2010 American Chemical Society.

  4. Catalytic pyrolysis of wheat bran for hydrocarbons production in the presence of zeolites and noble-metals by using TGA-FTIR method.

    Science.gov (United States)

    Lazdovica, K; Liepina, L; Kampars, V

    2016-05-01

    Pyrolysis of wheat bran with or without catalysts was investigated using TGA-FTIR method in order to determine the influence of zeolite and noble metal catalysts on the evolution profile and relative yield of the volatile compounds. The addition of all catalysts decreased the volatile matter of wheat bran from 76.3% to 75.9%, 73.9%, 73.5%, 69.7% and increased the solid residue from 18.0% to 18.4%, 20.4%, 20.8%, 24.6% under the catalyst of ZSM-5, 5% Pd/C, MCM-41, and 5% Pt/C. Noble-metal catalysts had higher activity for deoxygenation of compounds containing carbonyl, carboxyl, and hydroxyl groups than zeolites. Degradation of nitrogen containing compounds atom proceeded better in presence of zeolites. Noble-metal catalysts promoted formation of aromatics and changed the profiles of evolved compounds whereas zeolites advanced formation of aliphatics and olefins. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Synthesis of a new ONNO donor tetradentate schiff base ligand and binuclear Cu(II) complex: Quantum chemical, spectroscopic and photoluminescence investigations

    International Nuclear Information System (INIS)

    Sarıoğlu, Ahmet Oral; Ceylan, Ümit; Yalçın, Şerife Pınar; Sönmez, Mehmet; Ceyhan, Gökhan; Aygün, Muhittin

    2016-01-01

    The Schiff base compound 3,3′-(1,4-phenylimino)-bis-[1,3-bis-(4-methoxyphenyl) propan-1-one)], formulated as C 40 H 36 N 2 O 6, and its Cu(II) complex were synthesized and characterized by analytical analysis, various spectral techniques such as FT-IR, NMR, UV–vis, magnetic measurements and molar conductivity. Thermo gravimetric analysis (TGA and DTA) carried out to obtain information about its thermal stability. The molecular structure and spectroscopic properties of the ligand were obtained with FT-IR, 1 H and 13 C NMR, UV–vis investigations as experimentally and compared with theoretical results obtained from DFT/B3LYP/6-311++G(d,p) basis set. In addition to molecular calculations of the title compound, molecular electrostatic potential (MEP), dipole moments, atomic charges, HOMO–LUMO, NLO and NBO analysis were computed. The calculated results show that the optimized geometry can well reproduce the crystal structure parameters, and the theoretical vibrational frequencies, 1 H and 13 C NMR chemical shifts show good agreement with experimental values. Photoluminescence properties of the ligand and its Cu(II) complex were examined. - Highlights: • FT-IR and 1 H– 13 C NMR spectra were recorded and compared with the theoretical results. • The photoluminescence properties were studied. • NLO, NBO analysis of the molecule were studied. • HOMO and LUMO energies, MEP distribution of the molecule were calculated.

  6. Characteristics of Ampel bamboo as a biomass energy source potential in Bali

    Science.gov (United States)

    Sucipta, M.; Putra Negara, D. N. K.; Tirta Nindhia, T. G.; Surata, I. W.

    2017-05-01

    Currently, non-renewable fossil energy dominates utilization of the world energy need for many applications. Efforts has been developed to find alternative renewable energy sources, due to fossil energy availability is diminishing. And one of renewable energy source is from biomass. The aim of this research is to determine characteristics of the Ampel bamboo (Bambusa vulgaris) as an energy potential of biomass. The Ampel bamboo’s characteristics possessed are evaluated based on its chemical composition; moisture, volatile, ash, and fixed carbon through proximate analysis; and also carbon, hydrogen and nitrogen content through ultimate analysis. From the Thermo-gravimetric analysis (TGA) indicates that Ampel bamboo contains of about 18.10% hemicelluloses, 47.75% cellulose and 18.86% lignin. While from the ultimate analysis results in the content of carbon, hydrogen, and Nitrogen of Ampel bamboo are 39.75%, 5.75% and 0% respectively. With such characteristics, it indicates that Ampel bamboo has an attractive potential as a renewable energy source.

  7. Control of the shape and size of iron oxide (α-Fe2O3 nanoparticles synthesized through the chemical precipitation method

    Directory of Open Access Journals (Sweden)

    Abdelmajid Lassoued

    Full Text Available Hematite (α-Fe2O3 nanoparticles were synthesized via a simple chemical precipitation method. The impact of varying the concentration of precursor on the crystalline phase, size and morphology of α-Fe2O3 products was explored. The characteristic of the synthesized hematite nanoparticles were evaluated by X-ray diffraction (XRD, Transmission Electron Microscopy (TEM, Scanning Electron Microscopy (SEM, Fourier Transform Infra-Red (FT-IR spectroscopy, Raman spectroscopy, Differential Thermal Analysis (DTA, Thermo Gravimetric Analysis (TGA, Ultraviolet–Visible (UV–Vis analysis and Photoluminescence (PL. XRD data revealed a rhombohedral (hexagonal structure with the space group R-3c in all samples. Uniform spherical like morphology was confirmed by TEM and SEM. The result revealed that the particle sizes were varied between 21 and 82 nm and that the increase in precursor concentration (FeCl3, 6H2O is accompanied by an increase in the particle size of 21 nm for pure α-Fe2O3 synthesized with [Fe3+] = 0.05 M at 82 nm for pure α-Fe2O3 synthesized with [Fe3+] = 0.4 M. FT-IR confirms the phase purity of the nanoparticles synthesized. The Raman spectroscopy was used not only to prove that we have synthesized pure hematite but also to identify their phonon modes. The thermal behavior of compound was studied by using TGA/DTA results: The TGA showed three mass losses, whereas DTA resulted in three endothermic peaks. Besides, the optical investigation revealed that samples have an optical gap of about 2.1 eV and that this value varies as a function of the precursor concentration. Keywords: Nanoparticles, Hematite (α-Fe2O3, Precipitation, Precursor, Size, Band gap

  8. Latex stage blending of multiwalled carbon nanotube in carboxylated acrylonitrile butadiene rubber: Mechanical and electrical properties

    International Nuclear Information System (INIS)

    Preetha Nair, K.; Thomas, Paulbert; Joseph, Rani

    2012-01-01

    Highlights: ► MWCNT can act as a reinforcing filler in XNBR at very low concentration. ► SEM and XRD analysis confirm uniform distribution of nanotube in the matrix. ► Mechanical properties showed considerable improvement. ► Thermal stability of the composite is marginally improved. -- Abstract: Multiwalled carbon nanotube (MWCNT) was dispersed in sodium dodecyl benzene sulphonate (SDBS) by sonication. The dispersed MWCNT (0.05–0.3 gm) was incorporated in carboxylated acrylonitrile butadiene rubber (XNBR) latex. Mechanical, electrical and thermal properties of these composites were studied. Mechanical properties of the composites increased up to an optimum concentration and then decreased. Dielectric properties of the composites were studied in the S band (frequency range 2–4 GHz) by Cavity Perturbation method. Direct current (DC) electrical conductivity shows a percolation behaviour and conductivity increased by about 10 orders of magnitude. Thermal studies were conducted using Differential Scanning Calorimetry (DSC) and Thermo Gravimetric Analysis (TGA). As expected with the very small concentration of multiwalled carbon nanotube, glass transition temperature (T g ) and thermal stability of the composite showed a marginal increase. Composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and Scanning electron microscope (SEM) analysis.

  9. Investigation of intrinsic and extrinsic defects effective role on producing intense red emission in ZnO:Eu nanostructures

    Energy Technology Data Exchange (ETDEWEB)

    Najafi, Mehrdad, E-mail: najafi@shahroodut.ac.ir; Haratizadeh, Hamid

    2015-05-15

    Highlights: • Effective role of defects on producing red emission at indirect excitation. • V{sub Zn} and V{sub O} defects have important role on energy transfer. • Mg related defects and Zn{sub i} defects were responsible for blue emission. • Extrinsic and intrinsic defects mediated energy transfer to sensitize Eu{sup 3+} ions. • Decrease of red emission because of diminishing in oxygen vacancy. - Abstract: Europium doped ZnO nanorads and nanosheets were synthesized by hydrothermal method. Effects of Mg doping, morphology and annealing in oxygen ambient on structural and optical properties of ZnO nanostructures were investigated using X-ray diffraction (XRD), particle size analysis (PSA), thermo gravimetric analysis (TGA), differential thermal analysis (DTA), differential thermo gravimetry (DTG), scanning electron microscopy (SEM) and photoluminescence spectroscopy (PL). This study recommends that both of intrinsic and extrinsic defects facilitate energy transfer (ET) from the ZnO host to Eu{sup 3+} ions and consequently have efficient role on producing intense red emission at indirect excitation. The results also showed that annealing process improved the crystal structure of ZnO nanosheets due to decrease of surface defects; however decreased ET and red emission because of diminishing in oxygen vacancy. In addition in ZnO nanorods sample with more surface area in comparison with ZnO nanosheets sample deep level emissions are enhanced.

  10. The synthesis and the spectroscopic, thermal, and structural properties of the M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) clathrate (M = Co, Ni, Cd and Hg)

    Science.gov (United States)

    Kartal, Zeki; Yavuz, Abdülkerim

    2018-03-01

    In this study, the clathrates of fumarate-tetracyanonickel-dioxane, given by the formula M2[(fumarate)Ni(CN)4]·2(1,4-Dioxane) (M = Co, Ni, Cd and Hg), have been obtained for the first time through chemical methods. These clathrates have been characterized by elemental, thermal, FT-IR, and FT-Raman spectroscopies. The parameters of structures of clathrates have been determined by X-ray powder diffraction. The thermal behaviors of these clathrates have been also investigated by thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), and derivative thermal gravimetric analysis (DTG) in the range of 20-900 °C. X-ray powder diffraction data have been recorded at ambient temperature in the 2θ range 5-50°. The FT-IR and FT-Raman spectra of clathrates have been recorded in the region of 4000-400 cm-1 and 4000-100 cm-1, respectively. The results of the spectral and thermal analyses of the newly synthesized clathrates of fumarate-tetracyanonickel-dioxane suggest that these clathrates are new examples of the Hofmann-type dioxane clathrates. In our study, the Hofmann-type dioxane clathrates, which are formed by bounding electrons of oxygen-donor atoms of fumarate ion ligand molecule to transition metal atoms, consist of the corrugated |M-Ni(CN)4|∞ polymeric layers, which are held in parallel through the chain of (-M-fumarate-M-).

  11. Synthesis and characterization of CdO nano particles by the sol-gel method

    Science.gov (United States)

    Vadgama, V. S.; Vyas, R. P.; Jogiya, B. V.; Joshi, M. J.

    2017-05-01

    Cadmium Oxide (CdO) is an inorganic compound and one of the main precursors to other cadmium compounds. It finds applications in cadmium plating, storage batteries, in transparent conducting film, etc. Here, an attempt is made to synthesize CdO nano particles by sol-gel technique. The gel was prepared using cadmium nitrate tetra hydrate (Cd(NO3)2.4H2O) and aqueous ammonium hydroxide (NH4OH) as a precursor. The synthesized powder is further characterized by techniques like Powder X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and Thermal gravimetric analysis (TGA). Powder XRD analysis suggested the nano-crystalline nature of the sample with the cubic crystal system. Nano scaled particles of spherical morphology with the size ranging from 50-100 nm are observed from TEM images. While, FT-IR study is used to confirm the presence of different functional groups. Thermo-gravimetric analysis suggests the highly thermally stable nature of the samples. The results are discussed.

  12. Ultrasound-Assisted Extraction and Characterization of Pectic Polysaccharide from Oriental Tobacco Leaves

    International Nuclear Information System (INIS)

    Liu, S.; Tian, Z.; Li, X.; He, P.; Xu, C.

    2015-01-01

    Ultrasound-assisted extraction (UAE) of pectic Polysaccharide from oriental tobacco leaves was studied by orthogonal matrix method (L9(3)4). Furthermore, the crude Polysaccharide was purified and two components (Fr-I and Fr-II) were obtained. FT-IR spectral analysis of the purified EPS revealed prominent characteristic groups. The monosaccharide composition analysis indicated the main composition between Fr-I and Fr-II was different. Furthermore, thermo gravimetric analysis (TGA) indicated the degradation temperature (Td) of the Fr-I (215 degree C) was higher than those of Fr-II (162 degree C). Detected by the pyrolysis GC/MS, though the main kinds of pyrolysis products from both Fr-I and Fr-II were similar, the larger amount of heterocycle and aromatic compounds liberated after hydrolysis of Fr-II. Finally, On the basis of the antioxidant activity test in vitro, Fr-II has stronger antioxidant activities than Fr-I. The thermal behavior and antioxidant activity might be attributed to the configuration of the sugar units and chemical compositions. (author)

  13. A highly selective sorbent for removal of Cr(VI) from aqueous solutions based on Fe₃O₄/poly(methyl methacrylate) grafted Tragacanth gum nanocomposite: optimization by experimental design.

    Science.gov (United States)

    Sadeghi, Susan; Rad, Fatemeh Alavi; Moghaddam, Ali Zeraatkar

    2014-12-01

    In this work, poly(methyl methacrylate) grafted Tragacanth gum modified Fe3O4 magnetic nanoparticles (P(MMA)-g-TG-MNs) were developed for the selective removal of Cr(VI) species from aqueous solutions in the presence of Cr(III). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), a vibrating sample magnetometer (VSM), and thermo-gravimetric analysis (TGA). A screening study on operational variables was performed using a two-level full factorial design. Based on the analysis of variance (ANOVA) with 95% confidence limit, the significant variables were found. The central composite design (CCD) has also been employed for statistical modeling and analysis of the effects and interactions of significant variables dealing with the Cr(VI) uptake process by the developed sorbent. The predicted optimal conditions were situated at a pH of 5.5, contact time of 3.4 h, and 3.0 g L(-1) dose. The Langmuir, Freundlich, and Temkin isotherm models were used to describe the equilibrium sorption of Cr(VI) by the absorbent, and the Langmuir isotherm showed the best concordance as an equilibrium model. The adsorption process was followed by a pseudo-second-order kinetic model. Thermodynamic investigations showed that the biosorption process was spontaneous and exothermic. Copyright © 2014 Elsevier B.V. All rights reserved.

  14. Effect of Sr2TiMnO6 fillers on mechanical, dielectric and thermal behaviour of PMMA polymer

    Directory of Open Access Journals (Sweden)

    P. Thomas

    2015-09-01

    Full Text Available Composites of poly(methyl methacrylate (PMMA and Sr2TiMnO6 (STMO were fabricated via melt mixing followed by hot pressing technique. These were characterized using X-ray diffraction (XRD, thermo gravimetric analysis (TGA, differential scanning calorimetry (DSC, thermo mechanical analysis (TMA and impedance analyser for their structural, thermal and dielectric properties. The coefficient of thermal expansion (CTE was measured between 40°C and 100°C for pure PMMA is 115.2 ppm/°C, which was decreased to 78.58 ppm/°C when the STMO content was increased to 50 wt.% in PMMA. There was no difference in the glass transition (Tg temperature of the PMMA polymer and their composites. However, the FTIR analysis indicated possible interaction between the PMMA and STMO. The density and the hardness were increased as the STMO content increased in the PMMA matrix. Permittivity was found to be as high as 30.9 at 100 Hz for the PMMA+STMO-50 wt.% composites, indicating the possibility of using these materials for capacitor applications. The thermal stability of polymer was enhanced by incorporation of STMO fillers.

  15. Influence of MgSO{sub 4} doping on the properties of zinc tris–thiourea sulphate (ZTS) single crystals

    Energy Technology Data Exchange (ETDEWEB)

    Selvapandiyan, M., E-mail: mselvapandiyan@rediffmail.com [Department of Physics, Sri Vidya Mandir Arts and Science College, Uthangarai 635 207 (India); Arumugam, J. [Department of Physics, Sri Vidya Mandir Arts and Science College, Uthangarai 635 207 (India); Sundaramoorthi, P. [Department of Physics, Thiruvalluvar Government Arts College, Rasipuram 637 401 (India); Sudhakar, S. [CSIR–National Physical Laboratory, Dr. K.S. Krishnan Road, New Delhi 110 012 (India)

    2013-12-15

    Highlights: •The influence of MgSO{sub 4} doping on the properties of ZTS single crystals grown at room temperature. •Thermal stability of the crystals increased with incorporation of Mg atom. •Energy band gap was estimated from UV–vis spectra. •ZTS is a potential material for frequency conversion. •Both pure and doped ZTS crystals are belonging to category of typical insulating materials. -- Abstract: The influence of MgSO{sub 4} doping on the properties of zinc tris–thiourea sulphate single crystals grown at room temperature by slow evaporation solution growth technique was studied. Powder XRD analysis confirmed the orthorhombic crystal structure with noncentrosymmetric space group Pca2{sub 1}. The mechanical properties of the grown crystals were analysed by Vicker’s microhardness method. Functional groups present in the materials were identified by FTIR spectral analysis in the range between 4000 and 400 cm{sup −1}. The UV–Vis spectrum indicates that the UV cut-off wavelength of the crystals has less than 297 nm. The thermal stability of the grown crystals was determined with the aid of thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Second order nonlinear optical behaviour of the grown crystals have been confirmed by Kurtz powder second harmonic generation (SHG) test.

  16. A simple, sensitive graphical method of treating thermogravimetric analysis data

    Science.gov (United States)

    Abraham Broido

    1969-01-01

    Thermogravimetric Analysis (TGA) is finding increasing utility in investigations of the pyrolysis and combustion behavior of materuals. Although a theoretical treatment of the TGA behavior of an idealized reaction is relatively straight-forward, major complications can be introduced when the reactions are complex, e.g., in the pyrolysis of cellulose, and when...

  17. Tailoring the properties and functions of phosphate/silk/Ag/chitosan scaffolds

    International Nuclear Information System (INIS)

    Abdel-Fattah, Wafa I.; Sallam, Abdel Sattar M.; Diab, A.M.; Ali, Ghareib W.

    2015-01-01

    Two novel silk composites of phosphatic phases with nanosilver/chitosan having enhanced biocompatibility were achieved. Hydroxyapatite and octa calcium phosphates were synthesized in situ within silk fibroin/chitosan/nanosilver composites recently studied. Thermo-gravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) verified their thermal behavior. The structural aspects were characterized applying X-ray diffraction analysis (XRD), transmission electron microscopy (TEM) and field emission scanning electron microscope (FESEM) with EDAX. Additionally X-ray Photoelectron Spectroscopy (XPS) and Fourier Transform Infrared spectroscopy (FTIR) were applied. Mercury porosimeter was used to verify the pore size distribution. The in vitro degradation was followed in D-MEM for 48 h in a cumulative manner for five successive periods. Biochemical analyses of Ca, P and total protein using relevant chemical kits and atomic absorption for silver were performed. ANOVA statistics was carried out. Phosphatic crystalline phases along with the presence of silk, chitosan and nano-silver were developed. The diameters of hydroxyapatite and octa calcium phosphate particles were ~ 8–17 nm and 15–22 nm respectively. Comparatively higher degradation of Octa composite possessing higher porosity proved in turn more osteoinduction with in situ apatitic development. - Highlights: • A bottom–up approach controlled the achieved in situ configurations. • The calculated (CI) XDR and (CI) FTIR for both phases are highly conformable. • Post-immersion trimodal pore system was achieved in OCP composite. • Silver nanoparticle inclusion expected to enhance composite bactericidal activity

  18. Preparation and physico-chemical characterization of β-cyclodextrin incorporated chitosan biosorbent beads with potential environmental applications

    Science.gov (United States)

    Munim, Somayyah Abdul; Tahir Saddique, Muhammad; Raza, Zulfiqar Ali; Majeed, Muhammad Irfan

    2018-06-01

    Biosorption is one of the most efficient and feasible methods for eliminating noxious wastes from the aqueous systems. The use of non-hazardous, low-cost and biodegradable chitosan as a biosorbent is of significant importance in the above context. Present study was aimed to develop a β-cyclodextrin (β-CD) incorporated chitosan biosorbent in the form of beads. The prepared biosorbent beads were characterized using scanning electron microscopy (SEM), Fourier transform infrared (FTIR), x-ray diffraction (XRD) analysis, and thermo gravimetric analysis (TGA). The values of point of zero charge (PZC) of chitosan and β-CD incorporated chitosan beads were determined in the presence of an electrolyte by means of different methods including mass titration, salt addition and zeta potential ones. The SEM images exhibited roughened and porous morphologies which could enhance the adsorption of metal ions. The values of PZC of chitosan and β-CD incorporated chitosan biosorbent beads were found to be 6.38 and 7.12, respectively.

  19. A new method of application of hydrated salts on textiles to achieve thermoregulating properties

    International Nuclear Information System (INIS)

    Kazemi, Zeinab; Mortazavi, Sayed Majid

    2014-01-01

    Graphical abstract: - Highlights: • No need to microencapsulate the salt. • New method Glauber's salt dehydration. • Supercooling decreased, heat storage increased. - Abstract: Recently there has been a lot of attention to fibers and fabrics with thermoregulatory effects. We can acquire this quality using Phase Change Materials (PCM). In this investigation a simple method was used to keep Na 2 SO 4 ·10H 2 O as an inorganic PCM on textile structure. By this method it is not necessary for PCMs to be microencapsulated. Thermophysical properties and thermal stability effects of treated fabric was checked out by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). Fourier transform infrared spectroscopy (FT-IR) and X-ray diffractometry (XRD) analysis were used to study the chemical structure of the fabric with PCMs. The air transfer, water permeability, and some physical properties of treated fabric were also investigated. The results showed that, silicone rubber polymer could be applied on textile structure to hold PCM without microencapsulating, and treated textile can be served as an appropriate smart thermal insulator

  20. A new method of application of hydrated salts on textiles to achieve thermoregulating properties

    Energy Technology Data Exchange (ETDEWEB)

    Kazemi, Zeinab; Mortazavi, Sayed Majid, E-mail: mortaza@cc.iut.ac.ir

    2014-08-10

    Graphical abstract: - Highlights: • No need to microencapsulate the salt. • New method Glauber's salt dehydration. • Supercooling decreased, heat storage increased. - Abstract: Recently there has been a lot of attention to fibers and fabrics with thermoregulatory effects. We can acquire this quality using Phase Change Materials (PCM). In this investigation a simple method was used to keep Na{sub 2}SO{sub 4}·10H{sub 2}O as an inorganic PCM on textile structure. By this method it is not necessary for PCMs to be microencapsulated. Thermophysical properties and thermal stability effects of treated fabric was checked out by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA). Fourier transform infrared spectroscopy (FT-IR) and X-ray diffractometry (XRD) analysis were used to study the chemical structure of the fabric with PCMs. The air transfer, water permeability, and some physical properties of treated fabric were also investigated. The results showed that, silicone rubber polymer could be applied on textile structure to hold PCM without microencapsulating, and treated textile can be served as an appropriate smart thermal insulator.

  1. Biocompatibility studies of polyacrylonitrile membranes modified with carboxylated polyetherimide

    Energy Technology Data Exchange (ETDEWEB)

    Senthilkumar, S.; Rajesh, S.; Jayalakshmi, A.; Mohan, D., E-mail: mohantarun@gmail.com

    2013-10-15

    Poly (ether-imide) (PEI) was carboxylated and used as the hydrophilic modification agent for the preparation of polyacrylonitrile (PAN) membranes. Membranes were prepared with different blend compositions of PAN and CPEI by diffusion induced precipitation. The modified membranes were characterized by thermo gravimetric analysis (TGA), mechanical analysis, scanning electron microscopy (SEM) and contact angle measurement to understand the influence of CPEI on the properties of the membranes. The biocompatibility studies exhibited reduced plasma protein adsorption, platelet adhesion and thrombus formation on the modified membrane surface. The complete blood count (CBC) results of CPEI incorporated membranes showed stable CBC values and significant decrease in the complement activation were also observed. In addition to good cytocompatibility, monocytes cultured on these modified membranes exhibited improved functional profiles in 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. Thus it could be concluded that PAN/CPEI membranes with excellent biocompatibility can be useful for hemodialysis. Highlights: • Carboxylated PEI was prepared and utilized as hydrophilic modification agent. • CPEI incorporated into PAN to improved biocompatibility and cyto compatibility • Biocompatibility of membranes was correlated with morphology and hydrophilicity. • Antifouling studies of the PAN/CPEI membranes was studied by BSA as model foulant.

  2. Hydrothermal formation and characterization of magnesium oxysulfate whiskers

    International Nuclear Information System (INIS)

    Xiang, L.; Liu, F.; Li, J.; Jin, Y.

    2004-01-01

    Magnesium oxysulfate (5Mg(OH) 2 ·MgSO 4 ·3H 2 O) whiskers with a diameter of 0.2-1.0 μm and a length of 20-50 μm were synthesized via the hydrothermal treatment of the slurry formed by mixing the MgSO 4 and NaOH solutions at room temperature. The composition, morphology, structure and thermal behavior of the hydrothermal products were examined with X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermo-gravimetric analysis (TGA) and chemical analysis. The experimental results indicated that the process parameters, such as the concentration of the reactant, the dispersion of the Mg(OH) 2 slurry and the temperature in hydrothermal treatment should be controlled carefully to synthesis 5Mg(OH) 2 ·MgSO 4 ·3H 2 O whiskers and to avoid the formation of the sectorial or granular impurities. 5Mg(OH) 2 ·MgSO 4 ·3H 2 O whiskers were decomposed gradually and converted finally to MgO particles after being heated in air at temperature up to 1050 deg. C. Granular products formed if the heating temperature was above 320 deg. C

  3. Structure property relationship of a new nonlinear optical organic crystal: 1-(3,4-Dimethoxyphenyl-3-(3-fluorophenylprop-2-en-1-one for optical power limiting applications

    Directory of Open Access Journals (Sweden)

    S. Raghavendra

    Full Text Available A new organic potential nonlinear optical (NLO material 1-(3,4-dimethoxyphenyl-3-(3-fluorophenylprop-2-en-1-one (DMP3FP is crystallized in acetone. The single crystal X-ray diffraction data shows that material crystallizes into centro-symmetric orthorhombic space group Pbca with a = 15.6552(6 Å, b = 8.5571(3 Å, c = 20.7697(7 Å. The functional groups in DMP3FP molecule are identified by Fourier Transfer Infrared (FTIR spectra. The thermal stability and melting point are determined using thermo gravimetric analysis/differential thermal analysis (TGA/DTA. Using UV Visible spectral studies direct band gap energy of the crystal is determined to be 3.19 eV. The nonlinear absorption coefficient and optical power limiting of the crystal was studied using Z-scan technique. The crystal exhibits a self-focusing effect at a wavelength of 532 nm showing optical limiting and reverse saturable absorption by having excited state absorption coefficient greater than ground state absorption coefficient. Keywords: Nonlinear, Optical power limiting, Z-scan, Self-focusing

  4. Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO2 adsorption performance

    International Nuclear Information System (INIS)

    Sargazi, Ghasem; Afzali, Daryoush; Mostafavi, Ali; Ebrahimipour, S. Yousef

    2017-01-01

    This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2 k-1 factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m 2 /g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO 2 adsorption. - Graphical abstract: A facile route was used for fabrication of a new metal -organic framework based on tantalum nanostructures that have high surface area, considerable porosity, homogenous morphology, and small size distribution.

  5. Surface functionalization of solid state ultra-high molecular weight polyethylene through chemical grafting

    Science.gov (United States)

    Sherazi, Tauqir A.; Rehman, Tayyiba; Naqvi, Syed Ali Raza; Shaikh, Ahson Jabbar; Shahzad, Sohail Anjum; Abbas, Ghazanfar; Raza, Rizwan; Waseem, Amir

    2015-12-01

    The surface of ultra-high molecular weight polyethylene (UHMWPE) powder was functionalized with styrene using chemical grafting technique. The grafting process was initiated through radical generation on base polymer matrix in the solid state by sodium thiosulfate, while peroxides formed at radical sites during this process were dissociated by ceric ammonium nitrate. Various factors were optimized and reasonably high level of monomer grafting was achieved, i.e., 15.6%. The effect of different acids as additive and divinyl benzene (DVB) as a cross-linking agent was also studied. Post-grafting sulfonation was conducted to introduce the ionic moieties to the grafted polymer. Ion-exchange capacity (IEC) was measured experimentally and is found to be 1.04 meq g-1, which is in close agreement with the theoretical IEC values. The chemical structure of grafted and functionalized polymer was characterized by attenuated total reflection infrared spectroscopy (ATR-FTIR) and thermal properties were investigated by thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC). Thermal analysis depicts that the presence of radicals on the polymer chain accelerates the thermal decomposition process. The results signify that the chemical grafting is an effective tool for substantial surface modification and subsequent functionalization of polyethylene.

  6. Separator Membrane from Crosslinked Poly(Vinyl Alcohol and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride

    Directory of Open Access Journals (Sweden)

    Charu Vashisth Rohatgi

    2015-03-01

    Full Text Available In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride (PMVE-MA. Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity, thermal and electrochemical properties using differential scanning calorimetry (DSC, dynamic mechanical analysis (DMA, thermo-gravimetric analysis (TGA and electrochemical impedance spectroscopy (EIS. The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications.

  7. Thermal and magnetic behavior of Angustifolia Kunth bamboo fibers covered with Fe{sub 3}O{sub 4} particles

    Energy Technology Data Exchange (ETDEWEB)

    Calvo, S. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Arias, N.P. [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Departamento de Ingenieria Electrica, Electronica y Computacion, Facultad de Ingenieria y Arquitectura, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Giraldo, O., E-mail: ohggiraldo@hotmail.com [Laboratorio de Materiales Nanoestructurados y Funcionales, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia); Rosales-Rivera, A.; Moscoso, O. [Laboratorio de Magnetismo y Materiales Avanzados, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia, Sede Manizales, Manizales (Colombia)

    2012-08-15

    Several Angustifolia Kunth bamboo fibers, which have been previously treated with an alkaline solution, were coated with magnetite particles. The coating of the fibers was achieved by an in-situ co-precipitation method with Fe{sup 2+} and Fe{sup 3+}in NaOH or NH{sub 4}OH. The fibers were evaluated by chemical analysis using atomic absorption (A.A.) technique, structural characterization by X-ray diffraction (XRD), thermal stability with thermo-gravimetric analysis (TGA) in nitrogen at temperature range between 23 Degree-Sign C and 800 Degree-Sign C and magnetic behavior using vibrating sample magnetometry (VSM) applying a magnetic field between -27 KOe and 27 KOe at room temperature. We found that the thermal stability and magnetization depend of the synthesis method used to cover the Angustifolia Kunth bamboo fibers. In addition, an improved magnetic response was observed when NaOH solution is used to generate the magnetite coating on the fiber surface.

  8. Preparation of Modified Magnetic Nanocomposites Dithiooxamide/Fe3O4 for Preconcentration and Determination of Trace Amounts of Cobalt Ions in Food and Natural Water Samples

    Directory of Open Access Journals (Sweden)

    Ali Mirabi

    2016-09-01

    Full Text Available The first study on the high efficiency of nanometer-sized magnetic nanoparticles (Fe3O4 coated with sodium dodecyl sulfate (SDS and dithiooxamide as a new sorbent solid phase extraction has been reported. Modified magnetic nanicomposites was used to preconcentrate and separate Co (II ions in food and environmental water samples. Magnetic nanoparticles were prepared by chemical precipitation of Fe (II and Fe (III salts from aqueous solution by ammonia solution. These magnetic nanoparticles and nanocomposites were characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, thermo gravimetric analysis (TGA and elemental analysis CHNS. A micro sample introduction system was employed for the nebulization micro-volume of diluted solution into flame atomic absorption spectrometry (FAAS. The extraction conditions were optimized by selecting the appropriate extraction parameters including the amount of nanosorbent, pH value, volume of dithiooxamide and condition of eluting solution. The detection limit of this method for Co (II ions was 1.21 ng ml-1 and the R.S.D. was 0.9% (n=6. The advantages of this new method include rapidity, easy preparation of nanosorbents and a high preconcentration factor. The proposed method has been applied to the determination of Co (II ions at trace levels in real samples such as, kiwi, orange, cucumber, apple, green pepper, honey, potato, tap water, river water and sea water with satisfactory results.

  9. Gamma radiation synthesis of super absorbent hydrogels for different applications

    International Nuclear Information System (INIS)

    Marzouk, H.M.G.

    2015-01-01

    Super absorbent polymers (SAP) of carboxymethyl cellulose/acrylamide (CMC/PAM), carboxymethyl cellulose/acrylamide/Silica (CMC/AM/Si) and carboxymethyl cellulose/Polyvinyl alcohol (CMC/PVA) were synthesized by radiation-induced grafting using γ-irradiation technique. The effects of various parameters, such as irradiation dose, the content of CMC, PAM, PVA, and Silica gel on the swelling percent of produced hydrogels have been evaluated. The kinetic equilibrium swelling of the prepared copolymer hydrogels was studied, it was found that the maximum swelling percent was 5000 % for the CMC/PAM hydrogel, 12000 % for the CMC/PAM/Si composite hydrogel, and 6200 % for the CMC/PVA hydrogel. The gel fraction, equilibrium swelling and effect of ph on the swelling percent were also studied. The prepared copolymers were also characterized by FTIR spectral analysis, thermo gravimetric analysis (TGA), and scanning electron microscopy (SEM) techniques. In order to evaluate its controlled release potential, different prepared hydrogels were loaded with KNO 3 as an agrochemical model and its potential for controlled release of KNO 3 was studied and evaluated with respect to different parameters such as time of release, ph of the medium, and temperatures. The results obtained from swelling, loading of KNO 3 , and release behavior studies suggested and recommended the possible use of prepared hydrogels for enhancing the plantation of Linum Usitatissimum.

  10. VO2(B conversion to VO2(A and VO2(M and their oxidation resistance and optical switching properties

    Directory of Open Access Journals (Sweden)

    Zhang Yifu

    2016-03-01

    Full Text Available Vanadium dioxide VO2 has been paid in recent years increasing attention because of its various applications, however, its oxidation resistance properties in air atmosphere have rarely been reported. Herein, VO2(B nanobelts were transformed into VO2(A and VO2(M nanobelts by hydrothermal route and calcination treatment, respectively. Then, we comparatively studied the oxidation resistance properties of VO2(B, VO2(A and VO2(M nanobelts in air atmosphere by thermo-gravimetric analysis and differential thermal analysis (TGA/DTA. It was found that the nanobelts had good thermal stability and oxidation resistance below 341 °C, 408 °C and 465 °C in air, respectively, indicating that they were stable in air at room temperature. The fierce oxidation of the nanobelts occurred at 426, 507 and 645 °C, respectively. The results showed that the VO2(M nanobelts had the best thermal stability and oxidation resistance among the others. Furthermore, the phase transition temperatures and optical switching properties of VO2(A and VO2(M were studied by differential scanning calorimetry (DSC and variable temperature infrared spectra. It was found that the VO2(A and VO2(M nanobelts had outstanding thermochromic character and optical switching properties.

  11. Separator Membrane from Crosslinked Poly(Vinyl Alcohol) and Poly(Methyl Vinyl Ether-alt-Maleic Anhydride)

    Science.gov (United States)

    Rohatgi, Charu Vashisth; Dutta, Naba K.; Choudhury, Namita Roy

    2015-01-01

    In this work, we report separator membranes from crosslinking of two polymers, such as poly vinyl alcohol (PVA) with an ionic polymer poly(methyl vinyl ether-alt-maleic anhydride) (PMVE-MA). Such interpolymer-networked systems were extensively used for biomedical and desalination applications but they were not examined for their potential use as membranes or separators for batteries. Therefore, the chemical interactions between these two polymers and the influence of such crosslinking on physicochemical properties of the membrane are systematically investigated through rheology and by critical gel point study. The hydrogen bonding and the chemical interaction between PMVE-MA and PVA resulted in highly cross-linked membranes. Effect of the molecular weight of PVA on the membrane properties was also examined. The developed membranes were extensively characterized by studying their physicochemical properties (water uptake, swelling ratio, and conductivity), thermal and electrochemical properties using differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), thermo-gravimetric analysis (TGA) and electrochemical impedance spectroscopy (EIS). The DSC study shows the presence of a single Tg in the membranes indicating compatibility of the two polymers in flexible and transparent films. The membranes show good stability and ion conductivity suitable for separator applications. PMID:28347019

  12. Influence of different stabilizers on the encapsulation of desmopressin acetate into PLGA nanoparticles.

    Science.gov (United States)

    Primavessy, Daniel; Günday Türeli, Nazende; Schneider, Marc

    2017-09-01

    To address targeting and bioavailability issues of peptidic drugs like desmopressin, the encapsulation into nanoparticles (NP) has become standard in pharmaceutics. This study investigated the encapsulation of desmopressin into PLGA NP by the use of pharmaceutically common stabilizers as a precursor to future, optional targeting and bioavailability experiments. Polymer dry weights were measured by freeze drying and thermo gravimetric analysis (TGA). Particle sizes (ranging between 105 and 130nm, PDIDoppler-Anemometry (LDA) respectively. Highest loading efficiencies, quantified by RP-HPLC, were achieved with Pluronic F-68 as stabilizer of the inner aqueous phase (1.16±0.07μg desmopressin/mg PLGA) and were significantly higher than coating approaches and approaches without stabilizer (0.74±0.01μg/mg). Optimized nanoformulations are thus in competition with the concentration of commercial non-nanoparticulate desmopressin products. Stability of desmopressin after the process was evaluated by HPLC peak purity analysis (diode array detector) and by mass spectrometry. Desmopressin was shown to remain intact during the whole process; however, despite these very good results the encapsulation efficiency turned out to be a bottle neck and makes the system a challenge for potential applications. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO{sub 2} adsorption performance

    Energy Technology Data Exchange (ETDEWEB)

    Sargazi, Ghasem, E-mail: g.sargazi@gmail.com [Department of Nanotechnology Engineering, Mineral Industries Research Center, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Young Researchers Society, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Afzali, Daryoush, E-mail: daryoush_afzali@yahoo.com [Department of Nanotechnology, Graduate University of Advanced Technology, Kerman (Iran, Islamic Republic of); Mostafavi, Ali [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Ebrahimipour, S. Yousef [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman, Iran (Iran, Islamic Republic of); Pistachio Safety Research Center, Rafsanjan University of Medical Sciences, Rafsanjan, Iran (Iran, Islamic Republic of)

    2017-06-15

    This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2{sup k-1} factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m{sup 2}/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO{sub 2} adsorption. - Graphical abstract: A facile route was used for fabrication of a new metal -organic framework based on tantalum nanostructures that have high surface area, considerable porosity, homogenous morphology, and small size distribution.

  14. Investigation of Structure and Property of Indian Cocos nucifera L. Fibre

    Science.gov (United States)

    Basu, Gautam; Mishra, Leena; Samanta, Ashis Kumar

    2017-12-01

    Structure and physico-mechanical properties of Cocos nucifera L. fibre from a specific agro-climatic region of India, was thoroughly studied. Fine structure of the fibre was examined by Fourier Transform Infra-Red (FTIR) spectroscopy, Thermo-Gravimetric Analysis (TGA), X-Ray Diffraction (XRD), component analysis, Scanning Electron Microscope (SEM) and optical microscope. SEM shows prominent longitudinal cracks and micro-pores on the surface. XRD shows a low degree of crystallinity (45%), bigger crystallite size, and even the presence of appreciable amount of non-cellulose matter. FTIR reveals presence of large quantities of hydroxyl, phenolic and aldehyde groups. Component and thermal analyses indicates presence of cellulose and lignin as major components. Physical parameters reveal that, fibres are highly variable in length (range 44-305 mm), and diameter (range 100-795 µm). Mechanical properties of the fibre viz. breaking tenacity, breaking extensibility, specific work of rupture, and coefficient of friction were measured. Microbial decomposition test under soil reveals excellent durability of coconut fibre which makes it appropriate for the application in geotextiles. Mass specific electrical resistance of 4 Ω-kg/m2 indicates its enhanced insulation as compared to the jute.

  15. Multi-walled carbon nanotubes/polymer composites in absence and presence of acrylic elastomer (ACM).

    Science.gov (United States)

    Kumar, S; Rath, T; Mahaling, R N; Mukherjee, M; Khatua, B B; Das, C K

    2009-05-01

    Polyetherimide/Multiwall carbon nanotube (MWNTs) nanocomposites containing as-received and modified (COOH-MWNT) carbon nanotubes were prepared through melt process in extruder and then compression molded. Thermal properties of the composites were characterized by thermo-gravimetric analysis (TGA). Field emission scanning electron microscopy (FESEM) images showed that the MWNTs were well dispersed and formed an intimate contact with the polymer matrix without any agglomeration. However the incorporation of modified carbon nanotubes formed fascinating, highly crosslinked, and compact network structure throughout the polymer matrix. This showed the increased adhesion of PEI with modified MWNTs. Scanning electron microscopy (SEM) also showed high degree of dispersion of modified MWNTs along with broken ends. Dynamic mechanical analysis (DMA) results showed a marginal increase in storage modulus (E') and glass transition temperature (T(g)) with the addition of MWNTs. Increase in tensile strength and impact strength of composites confirmed the use the MWNTs as possible reinforcement agent. Both thermal and electrical conductivity of composites increased, but effect is more pronounced on modification due to formation of network of carbon nanotubes. Addition of acrylic elastomer to developed PEI/MWNTs (modified) nanocomposites resulted in the further increase in thermal and electrical properties due to the formation of additional bond between MWNTs and acrylic elastomers at the interface. All the results presented are well corroborated by SEM and FESEM studies.

  16. Utilization of crushed clay brick in concrete industry

    Directory of Open Access Journals (Sweden)

    Ali A. Aliabdo

    2014-03-01

    Full Text Available A comprehensive experimental program regarding the use of recycled aggregates produced from demolition of brick buildings is presented. The brick wastes were crushed, sorted and classified into coarse and fine aggregates as well as powder (CBP. The first phase of the research focuses on the effect of incorporating recycled aggregates on physico-mechanical properties of paste, mortar and concrete. Non-traditional tests including X-ray diffraction (XRD, thermo-gravimetric analysis (TGA and micro-structural analysis (MSA were performed. The second phase of the program explores the effect of using recycled aggregates on properties of concrete masonry units. A total of 44 mixtures were utilized throughout the program. Results show cement paste when modified with 25% CBP achieves smaller pore size and lower weight loss under high temperature than reference paste. Furthermore, the use of recycled aggregates reduces the overall unit weight of concrete masonry units. Actually, modified concrete masonry units incorporating recycled aggregates achieve lower unit weight, higher thermal resistance and absorption rate than reference units. Although considerable strength reduction is noticeable by substitution, compressive strength levels meet the Egyptian specifications limitations. Critical replacement ratios are suggested to produce load bearing-concrete masonry units. Based on experimental evidences, it can be stated that the use of recycled aggregate and dust made of clay bricks is promising in many applications where the thermal resistance, cost and environmental aspects are imperative.

  17. Synthesis and characterization of nano-pore thallium (III) ion-imprinted polymer as a new sorbent for separation and preconcentration of thallium.

    Science.gov (United States)

    Arbab-Zavar, Mohammad Hossien; Chamsaz, Mahmoud; Zohuri, Golamhossien; Darroudi, Abolfazl

    2011-01-15

    Thallium (III) ion-imprinted polymer (IIP) particles were synthesized by preparing the ternary complex of thallium (III) ions with 5,7-dichloroquinoline-8-ol (DCQ) and 4-vinylpyridine (VP). Thermal copolymerization with methyl methacrylate (functional monomer, MMA) and ethyleneglycoldimethacrylate (cross-linking monomer, EGDMA) was then performed in the presence of acetonitrile (porogen) and 2,2- azobisisobutyronitrile(initiator, AIBN). The imprinted ion was removed from polymer by stirring of the above particles with 5M HNO(3) to obtain the leached IIP particles. Moreover, control polymer (CP) particles were similarly prepared without the thallium (III) ions. The unleached and leached IIP particles were characterized by surface area analysis (BET), X-ray diffraction (XRD), Fourier transform infra-red spectroscopy (FT-IR), thermo gravimetric analysis (TGA) and scanning electron microscopy (SEM). The preconcentration of thallium (III) from aqueous solution was studied during rebinding with the leached IIP particles as a function of pH, the weight of the polymer material, the uptake and desorption times, the aqueous phase and the desorption volumes. Electrothermal atomic absorption spectrometry (ETAAS) was employed for determination of thallium in aqueous solution. The limit of detection for the method was 0.02 ng mL(-1), while the relative standard deviation for five replicates was 2.6%. Copyright © 2010 Elsevier B.V. All rights reserved.

  18. Zr doping dependence of structural and magnetic properties of cobalt ferrite synthesized by sol-gel based Pechini method

    Science.gov (United States)

    Motavallian, Pourya; Abasht, Behzad; Abdollah-Pour, Hassan

    2018-04-01

    Nanocrystalline CoZrxFe2-xO4 (0 ≤ x ≤ 0.3 in a step of 0.05) powders were synthesized by Pechini sol-gel method. The dry gel was grinded and calcined at 700 °C in a static air atmosphere for 1 h. Some tests such as thermo gravimetric analysis (TGA) combined with differential analysis (DTA), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM) and vibrating sample magnetometer (VSM) were carried out to investigate the thermal behaviour, structural bonds identification, crystallographic properties, morphology and magnetic properties of the obtained powders. X-ray diffraction revealed a single-phase cubic spinel structure for all samples, where the crystallite size decreases; the lattice parameter simultaneously increases with substitution of Zr. The results of FE-SEM showed that the particle size is in the 20-70 nm range. The magnetic properties such as saturation magnetization (Ms), remanent magnetization (Mr) and coercivity (Hc) were measured from the hysteresis loops. The greatest amount of saturation magnetization for CoZr0.05Fe1.95O4 sample was 67.9 emu·g-1.

  19. Characterization of coal blends for effective utilization in thermal power plants

    International Nuclear Information System (INIS)

    Santhosh Raaj, S.; Arumugam, S.; Muthukrishnan, M.; Krishnamoorthy, S.; Anantharaman, N.

    2016-01-01

    Highlights: • This work will assist utilities to decide on the choice of coals for blending. • Conventional and advanced analytical techniques were used for characterization. • Fuel ratio, burnout profile, ash chemistry and carbon burnout are key factors. • Basic properties were additive while carbon burnout was non additive for the blends. - Abstract: This paper deals with the characterization of coal blends using various conventional and advanced analytical techniques. There has been an increasing trend in utilizing imported coals for power generation in India and utilities are resorting to blended coal firing for various reasons, both financially as well as technically. Characterization studies were carried out on 2 combinations of Indian and imported coal blends. Conventional characterization such as proximate and ultimate analysis and determination of calorific value were carried out for the raw coals and blends as per ASTM standards. Following this thermal and mineral analysis of the samples were carried out using thermo gravimetric analyzer (TGA), X-ray fluorescence spectrometer (XRF) and computer controlled scanning electron microscope (CCSEM). Combustion experiments were also conducted using drop tube furnace (DTF) to determine the burnout of the raw coals and blends. The selection of technically suitable coal combination for blending, based on these characterization studies, has been detailed.

  20. Improving the quality of biopolymer (poly lactic acid) with the addition of bentonite as filler

    Science.gov (United States)

    Suryani; Agusnar, Harry; Wirjosentono, Basuki; Rihayat, Teuku; Nurhanifa

    2017-07-01

    PLA (Poly Lactid Acid) - Bentonite polymer nanocomposite which is a combination of natural and nanometer-scale inorganic substances created through three processes, mixing using a melt blending, molding with a hot press using specimens Standard ASTM D 638 Type IV and drying. In this study, PLA combined with two types of natural bentonite obtained from different areas to find differences in the quality of the results of characterization. To optimize the performance of filler, before mixing, bentonite have to furificate first with (NaPO3)6 and also open the interlayer space with CTAB. D-spacing of bentonite imterlayer were analyze by X-Ray difraction (XRD). Characterization bionanocomposite resulting morphologic structure was tested using a Transmission Electron Microscope (TEM). Mechanical analysis of PLA-bentonite nanocomposite in the form of tensile strength was tested using a tensile test specimens of standard American Standard for Testing Materials (ASTM) D 638 Type 4, and thermal resistance using Thermo Gravimetric Analysis (TGA).

  1. Synthesis, characterization and gas sensing properties of undoped and Zn-doped γ-Fe2O3-based gas sensors

    International Nuclear Information System (INIS)

    Jing Zhihong

    2006-01-01

    In this study, undoped and Zn-doped γ-Fe 2 O 3 nanopowders have been prepared using Fe(NO 3 ) 3 .9H 2 O and Zn(NO 3 ) 2 .6H 2 O as starting materials and lauryl alcohol as anhydrous medium. Thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), X-ray diffraction (XRD) and transmission electron micrograph (TEM) were employed to characterize the products. Sensitivity characteristics of the undoped and Zn-doped γ-Fe 2 O 3 semiconductor gas sensors have been investigated. The results show that both of the undoped and 15 mol% Zn-doped γ-Fe 2 O 3 -based gas sensors present good sensitivity and selectivity to acetone and ethanol in presence of CH 4 , H 2 and CO at the operating temperatures of 240 and 270 deg. C, respectively. After being doped with 15 mol% Zn addition, the γ-Fe 2 O 3 -based gas element displays higher sensitivity and selectivity as well as shorter response-recovery time compared with the undoped, suggesting that the promoting effect of ZnO is excellent. So, it seems that the γ-Fe 2 O 3 -based gas sensor doped with 15 mol% Zn is expected to be a promising sensor for detecting acetone and ethanol

  2. Solvothermal and electrochemical synthetic method of HKUST-1 and its methane storage capacity

    Science.gov (United States)

    Wahyu Lestari, Witri; Adreane, Marisa; Purnawan, Candra; Fansuri, Hamzah; Widiastuti, Nurul; Budi Rahardjo, Sentot

    2016-02-01

    A comparison synthetic strategy of Metal-Organic Frameworks, namely, Hongkong University of Techhnology-1 {HKUST-1[Cu3(BTC)]2} (BTC = 1,3,5-benzene-tri-carboxylate) through solvothermal and electrochemical method in ethanol:water (1:1) has been conducted. The obtained material was analyzed using powder X-ray diffraction, Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), Thermo-Gravimetric Analysis (TGA) and Surface Area Analysis (SAA). While the voltage in the electrochemical method are varied, ranging from 12 to 15 Volt. The results show that at 15 V the texture of the material has the best degree of crystallinity and comparable with solvothermal product. This indicated from XRD data and supported by the SEM image to view the morphology. The thermal stability of the synthesized compounds is up to 320 °C. The shape of the nitrogen sorption isotherm of the compound corresponds to type I of the IUPAC adsorption isotherm classification for microporous materials with BET surface area of 629.2 and 324.3 m2/g (for solvothermal and electrochemical product respectively) and promising for gas storage application. Herein, the methane storage capacities of these compounds are also tested.

  3. Synthesis and characterization of chitosan-PVP-nanocellulose composites for in-vitro wound dressing application.

    Science.gov (United States)

    Poonguzhali, R; Basha, S Khaleel; Kumari, V Sugantha

    2017-12-01

    Biocompatible Chitosan/Poly (vinyl pyrrolidone)/Nanocellulose (CPN) composites were successfully prepared by solution casting method. The prepared bionanocomposites were characterized by Transmission electron microscopy (TEM), Thermo gravimetric analysis (TGA), X-ray diffraction (XRD) and Attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) spectra. TEM images revealed the average particle size of the nanocellulose is 6.1nm. Thermogravimetric analysis indicated that the thermal stability of the composites was decreased with increasing concentration of nanocellulose. The CPN composites were characterized for physical properties like Thickness, Barrier properties and mechanical testing. Water vapor and oxygen permeability evaluations indicated that CPN composite could maintain a moist environment over wound bed. The nanocomposite showed enhanced swelling, blood compatibility and antibacterial activity. Cytotoxicity of the composite has been analyzed in normal mouse embryonic fibroblast cells. The results have shown the CPN3% composite shows a high level of antibacterial property when compared to the other composites. The biological study suggests that CPN3% composite may be a potential candidate as a wound healing material for biomedical application. Copyright © 2017 Elsevier B.V. All rights reserved.

  4. Effect of operating conditions on hydrothermal liquefaction of Spirulina over Ni/TiO2 catalyst.

    Science.gov (United States)

    Tian, Wenying; Liu, Renlong; Wang, Wenjia; Yin, Zhaosen; Yi, Xuewen

    2018-05-04

    In this study, the effects of reaction temperature, holding time, algae/water ratio and catalyst dosage on the yield and quality of bio-oil produced via the HTL of Spirulina were investigated. The maximum bio-oil yield (43.05 wt%) and energy recovery (ER) value (64.62%) were obtained at 260 °C for 30 min, with an algae/water ratio of 1/4 and a catalyst dosage of 5 wt%. The bio-oil samples were characterized by elemental analysis, Gas Chromatography-Mass Spectrometry (GC-MS), Fourier Transform Infrared (FI-IR), and Thermo-gravimetric analysis (TGA). Results indicated that higher heating values (HHVs) of bio-oils were in the range of 27.28-36.01 MJ/kg, and main compounds of bio-oil were amides, esters, nitriles, hydroperoxide and alkanes. Adding of the Ni/TiO 2 catalyst can decrease the contents of oxygenated and nitrogenous compounds and promote the formation of desirable components such as esters and alkanes. Copyright © 2018 Elsevier Ltd. All rights reserved.

  5. Preparation and characterization of Bi-doped TiO2 and its solar photocatalytic activity for the degradation of isoproturon herbicide

    International Nuclear Information System (INIS)

    Reddy, Police Anil Kumar; Srinivas, Basavaraju; Kala, Pruthu; Kumari, Valluri Durga; Subrahmanyam, Machiraju

    2011-01-01

    Highlights: → Visible active Bi-TiO 2 photocatalyst preparation and thorough charaterization. → Bi-TiO 2 shows high activity for isoproturon degradation under solar light irradiation. → The spectral response of TiO 2 shifts from UV to visible light region by Bi doping. → Bi 3+δ+ species are playing a vital role in minimizing e - /h + recombination. -- Abstract: Bi-doped TiO 2 catalyst was prepared by sol-gel method and was characterized by thermo gravimetric analysis (TGA), X-ray diffraction spectra (XRD), X-ray photo electronic spectroscopy (XPS), UV-Vis diffused reflectance spectra (DRS), photoluminescence spectra (PLS), transmission electron microscopy (TEM), energy dispersive analysis of X-rays (EDAX) and BET surface area. The photocatalytic activity of the catalysts were evaluated for the degradation of isoproturon herbicide under solar light irradiation. The UV-Visible DRS of Bi-doped TiO 2 showed red shift in optical absorption. The presence of Bi 3+δ+ species are playing a vital role in minimizing the electron hole recombination resulting higher activity compared to bare TiO 2 .

  6. Preparation and characterization of Bi-doped TiO{sub 2} and its solar photocatalytic activity for the degradation of isoproturon herbicide

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Police Anil Kumar; Srinivas, Basavaraju; Kala, Pruthu; Kumari, Valluri Durga [Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Hyderabad, India 500607 (India); Subrahmanyam, Machiraju, E-mail: subrahmanyam@iict.res.in [Inorganic and Physical Chemistry Division, Indian Institute of Chemical Technology, Hyderabad, India 500607 (India)

    2011-11-15

    Highlights: {yields} Visible active Bi-TiO{sub 2} photocatalyst preparation and thorough charaterization. {yields} Bi-TiO{sub 2} shows high activity for isoproturon degradation under solar light irradiation. {yields} The spectral response of TiO{sub 2} shifts from UV to visible light region by Bi doping. {yields} Bi{sup 3+{delta}+} species are playing a vital role in minimizing e{sup -}/h{sup +} recombination. -- Abstract: Bi-doped TiO{sub 2} catalyst was prepared by sol-gel method and was characterized by thermo gravimetric analysis (TGA), X-ray diffraction spectra (XRD), X-ray photo electronic spectroscopy (XPS), UV-Vis diffused reflectance spectra (DRS), photoluminescence spectra (PLS), transmission electron microscopy (TEM), energy dispersive analysis of X-rays (EDAX) and BET surface area. The photocatalytic activity of the catalysts were evaluated for the degradation of isoproturon herbicide under solar light irradiation. The UV-Visible DRS of Bi-doped TiO{sub 2} showed red shift in optical absorption. The presence of Bi{sup 3+{delta}+} species are playing a vital role in minimizing the electron hole recombination resulting higher activity compared to bare TiO{sub 2}.

  7. Ultrasound-assisted facile synthesis of a new tantalum(V) metal-organic framework nanostructure: Design, characterization, systematic study, and CO2 adsorption performance

    Science.gov (United States)

    Sargazi, Ghasem; Afzali, Daryoush; Mostafavi, Ali; Ebrahimipour, S. Yousef

    2017-06-01

    This work presents a fast route for the preparation of a new Ta(V) metal-organic framework nanostructure with high surface area, significant porosity, and small size distribution. X-ray diffraction (XRD), scanning electron microscopy (SEM), Transition electron microscopy (TEM), energy dispersive spectrometer (EDS), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), fourier transform infrared spectroscopy (FTIR), CHNS/O elemental analyser, and Brunauer-Emmett-Teller (BET) surface area analysis were applied to characterize the synthesized product. Moreover, the influences of ultrasonic irradiation including temperature, time, and power on different features of the final products were systematically studied using 2k-1 factorial design experiments, and the response surface optimization was used for determining the best welding parameter combination. The results obtained from analyses of variances showed that ultrasonic parameters affected the size distribution, thermal behaviour, and surface area of Ta-MOF samples. Based on response surface methodology, Ta-MOF could be obtained with mean diameter of 55 nm, thermal stability of 228 °C, and high surface area of 2100 m2/g. The results revealed that the synthesized products could be utilized in various applications such as a novel candidate for CO2 adsorption.

  8. Microstructure and soft magnetic properties of Finemet-type ribbons obtained by twin-roller melt-spinning

    International Nuclear Information System (INIS)

    Pozo Lopez, G.; Fabietti, L.M.; Condo, A.M.; Urreta, S.E.

    2010-01-01

    Soft magnetic ribbons of Finemet-type (Fe 73.5 Cu 1 Nb 3 Si 13.5 B 9 ) alloys are synthesized by the twin-roller melt-spinning technique directly from the melt, at tangential wheel speeds of 15, 18, 19 and 20 m/s. The microstructure and the magnetic properties are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), differential thermal analysis (DTA), thermo-gravimetric analysis (TGA) and hysteresis loops measurements. Samples cooled at 20 m/s are amorphous, while those quenched at lower wheel speeds are partially crystalline. All samples studied present saturation magnetization values (150-160 A m 2 /kg) higher than the commercial Finemet alloys (∼135 A m 2 /kg), obtained by controlled crystallization of amorphous single-roller melt-spun alloys. Optimal soft magnetic properties - σ S =(154±8) A m 2 /kg and H C =(6.9±0.9) A/m - are found in samples quenched at 19 m/s, consisting of size-distributed bcc Fe-Si nanograins (∼18 nm in average) embedded in an amorphous residual matrix. A minority nanocrystalline magnetic phase (≤10 nm) is also detected.

  9. Preparation and properties of carboxylated styrene-butadiene rubber/cellulose nanocrystals composites.

    Science.gov (United States)

    Cao, Xiaodong; Xu, Chuanhui; Liu, Yuhong; Chen, Yukun

    2013-01-30

    A series of carboxylated styrene-butadiene rubber (XSBR)/cellulose nanocrystals (CNs) latex composites were successfully prepared. The vulcanization process, morphology, dynamic viscoelastic behavior, dynamic mechanical property, thermal and mechanical performance of the XSBR/CNs composites were investigated in detail. The results revealed that CNs were dispersed uniformly in the XSBR matrix and formed a strong filler-filler network. The dynamic mechanical analysis (DMA) showed that the glass transition temperature (T(g)) of XSBR matrix was shifted from 48.45 to 50.64 °C with 3 phr CNs, but decreased from 50.64 to 46.28 °C when further increasing CNs content up to 15 phr. The composites exhibited a significant enhancement in tensile strength (from 16.9 to 24.1 MPa) and tear strength (from 43.5 to 65.2 MPa) with loading CNs from 0 to 15 phr. In addition, the thermo-gravimetric analysis (TGA) showed that the temperature at 5% weight loss of the XSBR/CNs composites decreased slightly with an increase of the CNs content. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  10. De novo DNA sequence driven bulk segregant analysis can pinpoint candicate loci for Total Glycoalkaloid (TGA) content in potato without prior knowledge of molecular markers

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sønderkær, Mads; Petersen, Annabeth Høgh

    is discarded based on the absence of desired molecular marker already at the seed or seedling stage. However, the number of molecular markers known in potato with appropriate linkage to agronomical traits is presently insufficient to establish a comprehensive MAS breeding platform for potato.......Potato breeding is a slow and costly affair, primarily done as a classical "mate and phenotype" approach using relatively small populations. In contrast, Marker Assisted Selection (MAS) allows cost-effective screening of much larger effective populations sizes because most of the offspring...

  11. Application of experimental design in examination of the dissolution rate of carbamazepine from formulations: Characterization of the optimal formulation by DSC, TGA, FT-IR and PXRD analysis

    OpenAIRE

    Krstić Marko; Ražić Slavica; Vasiljević Dragana; Spasojević Đurđija; Ibrić Svetlana

    2015-01-01

    Poor solubility is one of the key reasons for the poor bioavailability of these drugs. This paper displays a formulation of a solid surfactant system with carbamazepine, in order to increase its dissolution rate. Solid state surfactant systems are formed by application of fractal experimental design. Poloxamer 237 and Poloxamer 338 were used as surfactants and Brij® 35 was used as the co-surfactant. The ratios of the excipients and carbamazepine were varied...

  12. De novo DNA sequence driven bulk segregant analysis can pinpoint candicate loci for Total Glycoalkaloid (TGA) content in potato without prior knowledge of molecular markers

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sønderkær, Mads; Petersen, Annabeth Høgh

    is discarded based on the absence of desired molecular marker already at the seed or seedling stage. However, the number of molecular markers known in potato with appropriate linkage to agronomical traits is presently insufficient to establish a comprehensive MAS breeding platform for potato....

  13. Melt-Flow Behaviours of Thermoplastic Materials under Fire Conditions: Recent Experimental Studies and Some Theoretical Approaches

    Directory of Open Access Journals (Sweden)

    Paul Joseph

    2015-12-01

    Full Text Available Polymeric materials often exhibit complex combustion behaviours encompassing several stages and involving solid phase, gas phase and interphase. A wide range of qualitative, semi-quantitative and quantitative testing techniques are currently available, both at the laboratory scale and for commercial purposes, for evaluating the decomposition and combustion behaviours of polymeric materials. They include, but are not limited to, techniques such as: thermo-gravimetric analysis (TGA, oxygen bomb calorimetry, limiting oxygen index measurements (LOI, Underwriters Laboratory 94 (UL-94 tests, cone calorimetry, etc. However, none of the above mentioned techniques are capable of quantitatively deciphering the underpinning physiochemical processes leading to the melt flow behaviour of thermoplastics. Melt-flow of polymeric materials can constitute a serious secondary hazard in fire scenarios, for example, if they are present as component parts of a ceiling in an enclosure. In recent years, more quantitative attempts to measure the mass loss and melt-drip behaviour of some commercially important chain- and step-growth polymers have been accomplished. The present article focuses, primarily, on the experimental and some theoretical aspects of melt-flow behaviours of thermoplastics under heat/fire conditions.

  14. Melt-Flow Behaviours of Thermoplastic Materials under Fire Conditions: Recent Experimental Studies and Some Theoretical Approaches.

    Science.gov (United States)

    Joseph, Paul; Tretsiakova-McNally, Svetlana

    2015-12-15

    Polymeric materials often exhibit complex combustion behaviours encompassing several stages and involving solid phase, gas phase and interphase. A wide range of qualitative, semi-quantitative and quantitative testing techniques are currently available, both at the laboratory scale and for commercial purposes, for evaluating the decomposition and combustion behaviours of polymeric materials. They include, but are not limited to, techniques such as: thermo-gravimetric analysis (TGA), oxygen bomb calorimetry, limiting oxygen index measurements (LOI), Underwriters Laboratory 94 (UL-94) tests, cone calorimetry, etc. However, none of the above mentioned techniques are capable of quantitatively deciphering the underpinning physiochemical processes leading to the melt flow behaviour of thermoplastics. Melt-flow of polymeric materials can constitute a serious secondary hazard in fire scenarios, for example, if they are present as component parts of a ceiling in an enclosure. In recent years, more quantitative attempts to measure the mass loss and melt-drip behaviour of some commercially important chain- and step-growth polymers have been accomplished. The present article focuses, primarily, on the experimental and some theoretical aspects of melt-flow behaviours of thermoplastics under heat/fire conditions.

  15. Defect driven tailoring of colossal dielectricity of Reduced Graphene Oxide

    Energy Technology Data Exchange (ETDEWEB)

    Sarkar, S.; Mondal, A. [Department of Physics, Jadavpur University, Kolkata 700 032 (India); Dey, K. [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032 (India); Ray, R., E-mail: juphyruma@gmail.com [Department of Physics, Jadavpur University, Kolkata 700 032 (India)

    2016-02-15

    Highlights: • Reduced graphene oxides (RGO) are prepared by two chemical routes. • Defects in RGO are characterized by Raman, FTIR and XPS studies. • Defects tailor colossal dielectricity in RGO. - Abstract: Reduced graphene oxide (RGO) is prepared in two different chemical routes where reduction of graphene oxide is performed by hydrazine hydrate and through high pressure in hydrothermal reactor. Samples are characterized by X-ray powdered diffraction (XRD), thermo gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM) and tunneling electron microscopy (TEM). Types of defects are probed by Raman, FTIR spectroscopy and X-ray photoelectron spectroscopy (XPS). UV–vis absorption reveals different optical band gaps of the two RGOs. Conductivity mechanism is studied through I–V measurements displaying different characteristic features which are addressed due to the presence of defects appeared in different synthesis. Significantly high value (∼10{sup 4}) of dielectric permittivity at 10 MHz is attractive for technological application which could be tuned by the defects present in RGO.

  16. Pengaruh Massa Zn Dan Temperatur Hydrotermal Terhadap Struktur Dan Sifat Elektrik Material Graphene

    Directory of Open Access Journals (Sweden)

    Muhammad Rizki Ilhami

    2014-09-01

    Full Text Available Kemajuan teknologi yang sangat berkembang pada saat ini membutuhkan material yang tidak hanya kecil ataupun ringan, tetapi juga memiliki sifat thermal, elektrik, dan mekanik yang baik. Graphene adalah material yang dapat menjawab kebutuhan hal tersebut. Permasalahan yang kemudian muncul adalah proses sintesis massal yang masih menjadi kendala. Penelitian ini bertujuan untuk mensintesis material graphene dengan metode hydrothermal dan menggunakan serbuk Zn sebagai reduktor. Penelitian ini menganalisa pengaruh varaiasi penambahan massa sebesar 0,8 gram, 1,6 gram, dan 2,4 gram zinc serta variasi temperatur hydrthermal 160ᵒC, 180ᵒC, 200ᵒC. Proses karakterisasi material graphene dilakukan dengan pengujian Scanning Electron Microscope (SEM, X-Ray Diffraction (XRD, Fourier Transform Infraredspectroscopy, Thermo Gravimetric Analysis/Differential Scanning Calorimetry (TGA/DSC, dan Four Point Probe digunakan untuk mengetahui nilai konduktivitas elektrik material. Morfologi dari graphene yang dihasilkan berbentuk lembaran-lembaran transparan dan tipis yang saling menumpuk.Semakin banyak serbuk Zn yang diberikan menjadikan permukaan graphene semakin tipis. Nilai konduktivitas elektrik terbesar dihasilkan dari variasi panambahan serbuk zinc sebesar 2,4 gram dan temperatur hydrothermal sebesar 180ᵒC dengan nilai sebesar 0,012526 S/cm.

  17. Production of carbon nanotubes using mechanical milling in the presence of an exothermic reaction

    International Nuclear Information System (INIS)

    Karimi, E.Z.; Zebarjad, S.M.; Khaki, J. Vahdati; Izadi, H.

    2010-01-01

    Carbon nanotubes (CNTs) have shown promising potential for many applications in field of engineering due to their unusual significant properties. A major challenge for the industrial applications of CNTs is the large-quantity production. In this field, one new method for CNT production is annealing the ball milled graphite powder. The annealing process should be done in high temperature (1200-1400 o C) and needs time more than 6 h. The novel process introduced in this paper is elimination the annealing stage thorough a thermite reaction. The necessity heat for the conversion of milling products to CNTs was generated in the milling chamber by an exothermic reaction. In addition, the reaction products acted as catalysts to the CNT formation process. The adiabatic temperatures of 1809, 2000 and 2325 K were selected according to balancing graphite and thermite mixture (Aluminum + Iron oxide powders) for exothermic reaction. The results of thermo gravimetric analysis (TGA) test proved that CNT formation strongly depends on adiabatic temperature. The results of microscopic evaluation done by transition electron microscope (TEM) showed that at higher adiabatic temperature CNTs could be produced.

  18. Enhancing the crumb rubber modified asphalt’s storage stability through the control of its internal network structure

    Directory of Open Access Journals (Sweden)

    Mohyeldin Ragab

    2018-01-01

    Full Text Available The current research investigated the effect of the internal network structure developed in the crumb rubber modified asphalt (CRMA on its storage stability. The authors investigated the influence of asphalt-crumb rubber modifier (CRM interaction parameters (interaction time, interaction speed, and interaction temperature on the development of the internal network structure in CRMA. The authors found that the existence of three dimensional (3D network structures in the CRMA enhanced its storage stability. Fourier Transform Infrared (FTIR Spectroscopy was utilized to determine the nature of CRM components responsible for the development of 3D network structure in the liquid phase of CRMA. This was achieved by monitoring the changes of the IR distinctive peaks in the CRMA liquid phase. Dissolution tests and thermo gravimetric analysis (TGA were carried out on the extracted CRM after interaction with asphalt to determine the role of CRM dissolved amounts and released components on the development of 3D network structure in CRMA. The asphalt-CRM interaction parameters were found to be essential to induce the formation of the 3D network structure within the liquid phase of the CRMA through controlling the swelling, dissolution and release of CRM components into the asphalt liquid phase. The existence of 3D network structure in the CRMA had determinant impact on the enhancement of its storage stability. Keywords: Storage stability, Three dimensional (3D network, Crumb rubber modified asphalt

  19. Effect of calcination temperature on microstructure, dielectric, magnetic and optical properties of Ba0.7La0.3Fe11.7Co0.3O19 hexaferrites

    International Nuclear Information System (INIS)

    Kaur, Talwinder; Kaur, Barjinder; Bhat, Bilal H.; Kumar, Sachin; Srivastava, A.K.

    2015-01-01

    M-type barium hexaferrite Ba 0.7 La 0.3 Fe 11.7 Co 0.3 O 19 (BaLCM) powder, synthesized using sol gel auto combustion method, heat treated at 700, 900, 1100 and 1200 °C. X ray diffraction (XRD) powder patterns of heat treated samples show the formation of pure phase of M-type hexaferrite after 700 °C. Thermo gravimetric analysis (TGA) reveals that the weight loss of BaLCM becomes constant after 680 °C. The presence of two prominent peaks, at 432 cm −1 and 586 cm −1 in Fourier Transform Infrared Spectroscopy (FT-IR) spectra, gives the idea of formation of M-type hexaferrites. The M–H curve obtained from Vibrating Sample Magnetometer (VSM) were used to calculate saturation magnetization (M S ), retentivity (M r ), squareness ration (SR) and coercivity (H c ). The maximum value of coercivity (5602 Oe) is found at 900 °C. The band gap dependency on temperature was studied using UV–vis NIR spectroscopy. The dielectric constant has been found to be high at low frequency but it decreases with increase in frequency. Such kind of dielectric behavior is explained on the basis of Koop's phenomenological theory and Maxwell Wagner theory

  20. Optical, thermal and combustion properties of self-colored polyamide nanocomposites reinforced with azo dye surface modified ZnO nanoparticles

    Science.gov (United States)

    Hajibeygi, Mohsen; Shabanian, Meisam; Omidi-Ghallemohamadi, Mehrdad; Khonakdar, Hossein Ali

    2017-09-01

    New self-colored aromatic-polyamide (PA) nanocomposites containing azo and naphthalene chromophores were prepared with azo-dye surface-modified ZnO nanoparticles (SMZnO) using solution method in dimethylformamide. The X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) results showed the uniform distribution for ZnO nanoparticles in the PA matrix. The UV-vis spectra of PA/ZnO nanocomposites (PANC) showed a blue shift as well as reduction in absorbance intensities and the photoluminescence studies revealed that the increasing intensities of the violet emission in SMZnO loading. From thermo gravimetric analysis (TGA), the temperature at 10% mass loss (T10) increased from 291.8 °C to 387.6 °C for PANC containing 8 mass% of SMZnO, as well as the char yield enhanced significantly, which was about 23.5% higher than the neat PA. The peak heat release rate resulted from microscale combustion calorimeter (MCC), by 8 mass% loading of SMZnO, decreased about 56.9% lower than the neat PA.

  1. Preparation high photocatalytic activity of CdS/halloysite nanotubes (HNTs) nanocomposites with hydrothermal method

    Energy Technology Data Exchange (ETDEWEB)

    Xing Weinan [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Ni Liang, E-mail: xingweinan3@126.com [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Huo Pengwei; Lu Ziyang; Liu Xinlin; Luo Yingying; Yan Yongsheng [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China)

    2012-10-15

    Highlights: Black-Right-Pointing-Pointer CdS/halloysite nanotubes (HNTs) were synthesized by hydrothermal method. Black-Right-Pointing-Pointer The CdS/HNTs had better photocatalytic activity for degradation of tetracycline. Black-Right-Pointing-Pointer The presence of halloysite nanotubes both improved its photocatalytic activity and stability. - Abstract: A novel nanocatalyst CdS/halloysite nanotubes (HNTs) was synthesized by hydrothermal method with direct growth of CdS nanoparticles on the surface of HNTs. The as-prepared photocatalysts had been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), Fourier transform infrared (FT-IR) and the thermo gravimetric analysis (TGA). The photocatalytic activity of the sample was evaluated by the degradation of tetracycline (TC) under visible light irradiation. Benefit from the excellent properties of CdS and HNTs, the photocatalyst exhibited good photocatalytic activity and stability. In order to find out the optimum synthesis condition to obtain the best photocatalytic activity, a series of experiments were performed with different CdS loading capacity, different sources of sulfide and different hydrothermal temperatures, etc. The best photodegradation rate could reach 93% in 60 min under visible light irradiation. Therefore, the combination of CdS nanoparticles with HNTs endowed this material with a potential use in environmental treatments in industries.

  2. The partial replacement of palm kernel shell by carbon black and halloysite nanotubes as fillers in natural rubber composites

    Science.gov (United States)

    Daud, Shuhairiah; Ismail, Hanafi; Bakar, Azhar Abu

    2017-07-01

    The effect of partial replacement of palm kernel shell powder by carbon black (CB) and halloysite nanotube (HNT) on the tensile properties, rubber-filler interaction, thermal properties and morphological studies of natural rubber (NR) composites were investigated. Four different compositions of NR/PKS/CB and NR/PKS/HNT composites i.e 20/0, 15/5, 10/10,5/15 and 0/20 parts per hundred rubber (phr) were prepared on a two roll mill. The results showed that the tensile strength and modulus at 100% elongation (M100) and 300% elongation (M300) were higher for NR/PKS/CB compared to NR/PKS/HNT composites. NR/PKS/CB composites had the lowest elongation at break (Eb). The effect of commercial fillers in NR/PKS composites on tensile properties was confirmed by the rubber-filler interaction and scanning electron microscopy (SEM) study. The thermal stability of PKS filled NR composites with partially replaced by commercial fillers also determined by Thermo gravimetric Analysis (TGA).

  3. Green synthesis of biocompatible carbon dots using aqueous extract of Trapa bispinosa peel

    Energy Technology Data Exchange (ETDEWEB)

    Mewada, Ashmi; Pandey, Sunil, E-mail: gurus.spandey@gmail.com; Shinde, Sachin; Mishra, Neeraj; Oza, Goldie; Thakur, Mukeshchand; Sharon, Maheshwar; Sharon, Madhuri, E-mail: sharonmadhuri@gmail.com

    2013-07-01

    We are reporting highly economical plant based method for the production of luminescent water soluble carbon dots (C-dot) using Indian water plant Trapa bispinosa peel extract without adding any external oxidizing agent at 90 °C. C-dots ranging from 5 to 10 nm were found in the solution with a prominent green fluorescence under UV-light (λ{sub ex} = 365 nm). UV–vis spectra recorded at different time intervals (30–120 min) displayed signature absorption of C-dots between 400 and 600 nm. Fluorescence spectra of the dispersion after 120 min of synthesis exhibited characteristic emission peaks of C-dots when excited at 350, 400, 450 and 500 nm. C-dots were further analyzed using X-ray diffraction (XRD), Raman Spectroscopy and Thermo-Gravimetric Analysis (TGA). Structure of the C-dots was found to be turbostratic when studied using XRD. C-dots synthesized by our method were found to be exceptionally biocompatible against MDCK cells. Highlights: • Novel report on biosynthesis of water soluble carbon dots using plant source • Prominent green fluorescence under UV light • Highly biocompatible nanoparticles against MDCK cells • Excellent imaging properties under fluorescent light.

  4. Pyrolysis of Jatropha curcas pressed cake for bio-oil production in a fixed-bed system

    International Nuclear Information System (INIS)

    Jourabchi, Seyed Amirmostafa; Gan, Suyin; Ng, Hoon Kiat

    2014-01-01

    Highlights: • The pyrolysis of Jatropha curcas waste in a fixed-bed rig was studied. • Yield, calorific value, water content and acidity of bio-oil were compared. • Empirical correlations for bio-oil yield and specifications were developed. • Optimisation of bio-oil production based on combined specifications was achieved. - Abstract: This study investigated the effects of pyrolysis parameters on the yield and quality of bio-oil from Jatropha curcas pressed cake. This biomass was pyrolysed in a fixed-bed reactor over a temperature range of 573.15 K to 1073.15 K and a nitrogen linear speed range of 7.8 × 10 −5 m/s to 6.7 × 10 −2 m/s. The heating rate and biomass grain size were 50 K/min and <2 mm, respectively. The bio-oils were tested for the gross calorific value, water content and acidity. The pyrolysis process was simulated using Thermo-Gravimetric Analysis (TGA) and Differential Scanning Calorimeter (DSC) for mass and energy balances analyses. Empirical correlations between the bio-oil specifications and pyrolysis parameters were developed using linear and nonlinear multiple regression methods for process optimisation. At optimum pyrolysis conditions, above 50% of the waste is converted to bio-oil with less than 30% water content, a gross calorific value of 15.12 MJ/kg and a pH of 6.77

  5. Electrical characterization of reduced graphene oxide (rGO) on organic thin film transistor (OTFT)

    Science.gov (United States)

    Musa, Nurhazwani; Halim, Nurul Farhanah Ab.; Ahmad, Mohd Noor; Zakaria, Zulkhairi; Hashim, Uda

    2017-03-01

    A green method and eco-friendly solution were used to chemically reduce graphene oxide (GO) to graphene using green reductant. In this study, graphene oxide (GO) were prepared by using Tours method. Then, reduced graphene oxides (rGO) were prepared by using three typical reduction agents: L-ascorbic acid (L-AA), formamidinesulfinic acid (FAS) and sodium sulfite (Na2SO3). The reduced materials were characterized by Fourier transform infrared spectroscopy (FTIR), Thermo gravimetric analysis (TGA) and X-ray diffraction (XRD). Graphene based organic thin film transistor (G-OTFT) was prepared by a spin coating and thermal evaporation technique. The electrical characterization of G-OTFT was analyzed by using semiconductor parameter analyzer (SPA). The G-OTFT devices show p-type semiconducting behaviour. This article focuses on the synthesis and reduction of graphene oxide using three different reductants in order to maximise its electrical conductivity. The rGO product demonstrated a good electrical conductivity performance with highly sensitivity sensor.

  6. Preparation high photocatalytic activity of CdS/halloysite nanotubes (HNTs) nanocomposites with hydrothermal method

    International Nuclear Information System (INIS)

    Xing Weinan; Ni Liang; Huo Pengwei; Lu Ziyang; Liu Xinlin; Luo Yingying; Yan Yongsheng

    2012-01-01

    Highlights: ► CdS/halloysite nanotubes (HNTs) were synthesized by hydrothermal method. ► The CdS/HNTs had better photocatalytic activity for degradation of tetracycline. ► The presence of halloysite nanotubes both improved its photocatalytic activity and stability. - Abstract: A novel nanocatalyst CdS/halloysite nanotubes (HNTs) was synthesized by hydrothermal method with direct growth of CdS nanoparticles on the surface of HNTs. The as-prepared photocatalysts had been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), UV–vis diffuse reflectance spectra (UV–vis DRS), Fourier transform infrared (FT-IR) and the thermo gravimetric analysis (TGA). The photocatalytic activity of the sample was evaluated by the degradation of tetracycline (TC) under visible light irradiation. Benefit from the excellent properties of CdS and HNTs, the photocatalyst exhibited good photocatalytic activity and stability. In order to find out the optimum synthesis condition to obtain the best photocatalytic activity, a series of experiments were performed with different CdS loading capacity, different sources of sulfide and different hydrothermal temperatures, etc. The best photodegradation rate could reach 93% in 60 min under visible light irradiation. Therefore, the combination of CdS nanoparticles with HNTs endowed this material with a potential use in environmental treatments in industries.

  7. Preparation high photocatalytic activity of CdS/halloysite nanotubes (HNTs) nanocomposites with hydrothermal method

    Science.gov (United States)

    Xing, Weinan; Ni, Liang; Huo, Pengwei; Lu, Ziyang; Liu, Xinlin; Luo, Yingying; Yan, Yongsheng

    2012-10-01

    A novel nanocatalyst CdS/halloysite nanotubes (HNTs) was synthesized by hydrothermal method with direct growth of CdS nanoparticles on the surface of HNTs. The as-prepared photocatalysts had been characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), UV-vis diffuse reflectance spectra (UV-vis DRS), Fourier transform infrared (FT-IR) and the thermo gravimetric analysis (TGA). The photocatalytic activity of the sample was evaluated by the degradation of tetracycline (TC) under visible light irradiation. Benefit from the excellent properties of CdS and HNTs, the photocatalyst exhibited good photocatalytic activity and stability. In order to find out the optimum synthesis condition to obtain the best photocatalytic activity, a series of experiments were performed with different CdS loading capacity, different sources of sulfide and different hydrothermal temperatures, etc. The best photodegradation rate could reach 93% in 60 min under visible light irradiation. Therefore, the combination of CdS nanoparticles with HNTs endowed this material with a potential use in environmental treatments in industries.

  8. Graft copolymerization of N-vinyl-2-pyrrolidone onto pre-irradiated poly(vinylidene fluoride) powder

    International Nuclear Information System (INIS)

    Xu Chenqi; Huang Wei; Zhou Yongfeng; Yan Deyue; Chen Shutao; Huang Hua

    2012-01-01

    Graft copolymerization of N-vinyl-2-pyrrolidone (NVP) onto 60 Co γ-ray pre-irradiated poly (vinylidene fluoride) (PVDF) powder was investigated to find out the relationship between the degree of grafting (DG) and various factors, including monomer concentration, irradiation dose, reaction time, catalyst and so on. The DG can be calculated by comparing the amount of nitrogen element in the resulting copolymer (PVDF-g-PVP) powder with that in PVP on the basis of element analysis. The presence of PVP in the resulting PVDF powder was confirmed by the comparative studies of pristine PVDF and grafted PVDF powder through Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance (NMR), X-ray photoelectron spectroscopy (XPS), thermo gravimetric analyzer (TGA) and differential scanning calorimetry (DSC), respectively. When the reaction was performed at the monomer concentration of 20% (vol.) and the absorbed dose of 40 kGy for 3 h in water, the max. DG of 17.7% was obtained. - Highlights: ► We modify pristine PVDF powders with NVP by the pre-irradiated graft polymerization. ► The various factors influencing the degree of grafting are investigated in detail. ► The optimal condition of graft polymerization is obtained. ► The polymerization is processed at 20% (vol.) of NVP and 40kGy for 3 hours in water. ► The maximum degree of grafting is 17.7 % at such a condition.

  9. Microstructures and physical properties of waste garnets as a promising construction materials

    Directory of Open Access Journals (Sweden)

    Habeeb Lateef Muttashar

    2018-06-01

    Full Text Available Rapid industrial growth has witnessed the ever-increasing utilization of sand from rivers for various construction purposes, which caused an over-exploitation of rivers’ beds and disturbed the eco-system. strong engineering properties of waste garnets offer a recycling alternative to create efficient construction materials. Recycling of garnets provides a cost-effective and environmentally responsible solution rather than dumping it as industrial waste. In this spirit, this article presents an investigation into the capacity of spent garnets as sand replacement. The main parameters studied were the evolution of leaching performance, microstructure of the raw spent garnet and sand specimens. The microstructures, boning vibrations and thermal properties of the raw materials were determined using X-ray diffraction (XRD, field emission scanning microscopy (FESEM, Fourier transform infrared (FTIR spectroscopy, and thermo gravimetric analysis (TGA. Admirable features of the results suggest that the spent garnet is proven to be suitable replacement of sand. It is established that proper exploitation of spent garnet as an alternative to sand could save the earth from depleting the natural resources which is essential for sustainable development. Keywords: Spent garnet, Sand, Micro-structures, Recycling, Concrete

  10. Structural modifications of swift heavy ion irradiated PEN probed by optical and thermal measurements

    International Nuclear Information System (INIS)

    Devgan, Kusum; Singh, Lakhwant; Samra, Kawaljeet Singh

    2013-01-01

    Highlights: • The present paper reports the effect of swift heavy ion irradiation on Polyethylene Naphthalate (PEN). • Swift heavy ion irradiation introduces structural modification and degradation of PEN at different doses. • Lower irradiation doses in PEN result in modification of structural properties and higher doses lead to complete degradation. • Strong correlation between structural, optical, and thermal properties. - Abstract: The effects of swift heavy ion irradiation on the structural characteristics of Polyethylene naphthalate (PEN) were studied. Samples were irradiated in vacuum at room temperature by lithium (50 MeV), carbon (85 MeV), nickel (120 MeV) and silver (120 MeV) ions with the fluence in the range of 1×10 11 –3×10 12 ions cm −2 . Ion induced changes were analyzed using X-ray diffraction (XRD), Fourier transform infra red (FT-IR), UV–visible spectroscopy, thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC) techniques. Cross-linking was observed at lower doses resulting in modification of structural properties, however higher doses lead to the degradation of the investigated polymeric samples

  11. Effect of calcination temperature on microstructure, dielectric, magnetic and optical properties of Ba{sub 0.7}La{sub 0.3}Fe{sub 11.7}Co{sub 0.3}O{sub 19} hexaferrites

    Energy Technology Data Exchange (ETDEWEB)

    Kaur, Talwinder [Department of Physics, Lovely Professional University, Phagwara, Punjab 144411 (India); Kaur, Barjinder [Department of Physics, National Institute of Technology, Jalandhar 144011 (India); Bhat, Bilal H. [Department of Physics, University of Kashmir, 190006 (India); Kumar, Sachin [Department of Chemistry, Guru Nanak Dev University, Amritsar 143005 (India); Srivastava, A.K., E-mail: srivastava_phy@yahoo.co.in [Department of Physics, Lovely Professional University, Phagwara, Punjab 144411 (India)

    2015-01-01

    M-type barium hexaferrite Ba{sub 0.7}La{sub 0.3}Fe{sub 11.7}Co{sub 0.3}O{sub 19} (BaLCM) powder, synthesized using sol gel auto combustion method, heat treated at 700, 900, 1100 and 1200 °C. X ray diffraction (XRD) powder patterns of heat treated samples show the formation of pure phase of M-type hexaferrite after 700 °C. Thermo gravimetric analysis (TGA) reveals that the weight loss of BaLCM becomes constant after 680 °C. The presence of two prominent peaks, at 432 cm{sup −1} and 586 cm{sup −1} in Fourier Transform Infrared Spectroscopy (FT-IR) spectra, gives the idea of formation of M-type hexaferrites. The M–H curve obtained from Vibrating Sample Magnetometer (VSM) were used to calculate saturation magnetization (M{sub S}), retentivity (M{sub r}), squareness ration (SR) and coercivity (H{sub c}). The maximum value of coercivity (5602 Oe) is found at 900 °C. The band gap dependency on temperature was studied using UV–vis NIR spectroscopy. The dielectric constant has been found to be high at low frequency but it decreases with increase in frequency. Such kind of dielectric behavior is explained on the basis of Koop's phenomenological theory and Maxwell Wagner theory.

  12. A green approach to prepare silver nanoparticles loaded gum acacia/poly(acrylate) hydrogels.

    Science.gov (United States)

    Bajpai, S K; Kumari, Mamta

    2015-09-01

    In this work, gum acacia (GA)/poly(sodium acrylate) semi-interpenetrating polymer networks (Semi-IPN) have been fabricated via free radical initiated aqueous polymerization of monomer sodium acrylate (SA) in the presence of dissolved Gum acacia (GA), using N,N'-methylenebisacrylamide (MB) as cross-linker and potassium persulphate (KPS) as initiator. The semi-IPNs, synthesized, were characterized by various techniques such as X-ray diffraction (XRD), thermo gravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectroscopy. The dynamic water uptake behavior of semi-IPNs was investigated and the data were interpreted by various kinetic models. The equilibrium swelling data were used to evaluate various network parameters. The semi-IPNs were used as template for the in situ preparation of silver nanoparticles using extract of Syzygium aromaticum (clove). The formation of silver nanoparticles was confirmed by surface plasmon resonance (SPR), XRD and transmission electron microscopy (TEM). Finally, the antibacterial activity of GA/poly(SA)/silver nanocomposites was tested against E. coli. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Synthesis and Characterization of β-Cyclodextrin Functionalized Ionic Liquid Polymer as a Macroporous Material for the Removal of Phenols and As(V

    Directory of Open Access Journals (Sweden)

    Muggundha Raoov

    2013-12-01

    Full Text Available β-Cyclodextrin-ionic liquid polymer (CD-ILP was first synthesized by functionalized β-cyclodextrin (CD with 1-benzylimidazole (BIM to form monofunctionalized CD (βCD-BIMOTs and was further polymerized using a toluene diisocyanate (TDI linker to form insoluble CD-ILP (βCD-BIMOTs-TDI. The βCD-BIMOTs-TDI polymer was characterized using various tools and the results obtained were compared with those derived from the native β-cyclodextrin polymer (βCD-TDI. The SEM result shows that the presence of ionic liquid (IL increases the pore size, while the thermo gravimetric analysis (TGA result shows that the presence of IL increases the stability of the polymer. Meanwhile, Brunauer-Emmett-Teller (BET results show that βCD-BIMOTs-TDI polymer has 1.254 m2/g surface areas and the Barret-Joyner-Halenda (BJH pore size distribution result reveals that the polymer exhibits macropores with a pore size of 77.66 nm. Preliminary sorption experiments were carried out and the βCD-BIMOTs-TDI polymer shows enhanced sorption capacity and high removal towards phenols and As(V.

  14. Gold nano particle decorated graphene core first generation PAMAM dendrimer for label free electrochemical DNA hybridization sensing.

    Science.gov (United States)

    Jayakumar, K; Rajesh, R; Dharuman, V; Venkatasan, R; Hahn, J H; Pandian, S Karutha

    2012-01-15

    A novel first generation (G1) poly(amidoamine) dendrimer (PAMAM) with graphene core (GG1PAMAM) was synthesized for the first time. Single layer of GG1PAMAM was immobilized covalently on mercaptopropionic acid (MPA) monolayer on Au transducer. This allows cost effective and easy deposition of single layer graphene on the Au transducer surface than the advanced vacuum techniques used in the literature. Au nano particles (17.5 nm) then decorated the GG1PAMAM and used for electrochemical DNA hybridization sensing. The sensor discriminates selectively and sensitively the complementary double stranded DNA (dsDNA, hybridized), non-complementary DNA (ssDNA, un-hybridized) and single nucleotide polymorphism (SNP) surfaces. Interactions of the MPA, GG1PAMAM and the Au nano particles were characterized by Ultra Violet (UV), Fourier Transform Infrared (FTIR), Raman spectroscopy (RS), Thermo gravimetric analysis (TGA), Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Cyclic Voltmetric (CV), Impedance spectroscopy (IS) and Differntial Pulse Voltammetry (DPV) techniques. The sensor showed linear range 1×10(-6) to 1×10(-12) M with lowest detection limit 1 pM which is 1000 times lower than G1PAMAM without graphene core. Copyright © 2011 Elsevier B.V. All rights reserved.

  15. Influence of dilution level on oxidation resistance of plasma transferred arc NiCrAlC coatings

    International Nuclear Information System (INIS)

    Benegra, M.; Farina, A.B.; Goldenstein, H.; Oliveira, A.S.C.M. d'

    2010-01-01

    NICRALC coatings processed by Plasma Transferred Arc (PTA) are a new proposal to protect the components exposed to high-temperature oxidation environments. This study evaluated the relationship between the compositional changes in the coatings due to the different levels of dilution, and the morphology and phase constitution of the developing protective oxide scale. Elementary powders were mixed and deposited by PTA welding onto AISI 316L stainless steel, varying current intensity (100 and 130 A). The microstructure of specimens was characterized by means of scanning electron microscopy with local chemical analysis and by X-Ray diffraction. The coatings were subjected to thermo-gravimetric balance (TGA), using temperatures range of 700-1,000 °C during 5 hours. Results revealed the alumina formation, independent on the compositional variation. For low dilution level transient q-alumina was observed, while for high dilution level resulted in a stable a-alumina. This difference was attributed to the complexity of aluminum diffusion in intermetallic structures. The accumulated mass were smaller than other materials employed to high-temperature, such as as-cast NiCrAlC, indicating better oxidation resistance of the tested coatings. (author)

  16. Development of Eco-friendly Soy Protein Isolate Films with High Mechanical Properties through HNTs, PVA, and PTGE Synergism Effect

    Science.gov (United States)

    Liu, Xiaorong; Song, Ruyuan; Zhang, Wei; Qi, Chusheng; Zhang, Shifeng; Li, Jianzhang

    2017-03-01

    This study was to develop novel soy protein isolate-based films for packaging using halloysite nanotubes (HNTs), poly-vinyl alcohol (PVA), and 1,2,3-propanetriol-diglycidyl-ether (PTGE). The structural, crystallinity, opacity, micromorphology, and thermal stability of the resultant SPI/HNTs/PVA/PTGE film were analyzed by the Attenuated total reflectance-Fourier transformed infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), UV-Vis spectrophotometry, scanning electron microscopy (SEM), and thermo-gravimetric analysis (TGA). The SPI/HNTs/PVA/PTGE film illustrated that HNTs were uniformly dispersed in the SPI matrix and the thermal stability of the film was enhanced. Furthermore, the tensile strength (TS) of the SPI/HNTs/PVA/PTGE film was increased by 329.3% and the elongation at the break (EB) remained unchanged. The water absorption (WA) and the moisture content (MC) were decreased by 5.1% and 10.4%, respectively, compared to the unmodified film. The results highlighted the synergistic effects of SPI, HNTs, PVA, and PTGE on the mechanical properties, water resistance, and thermal stability of SPI films, which showed excellent strength and flexibility. In short, SPI films prepared from HNTs, PVA, and PTGE showed considerable potential as packaging materials.

  17. Application of Eh-pH diagram for room temperature precipitation of zinc stannate microcubes in an aqueous media

    International Nuclear Information System (INIS)

    Al-Hinai, Ashraf T.; Al-Hinai, Muna H.; Dutta, Joydeep

    2014-01-01

    Graphical abstract: - Highlights: • One pot aqueous synthesis of zinc stannate (ZnSnO 3 ) particles at low temperature. • Synthesis designed with the assistance of potential-pH diagram. • ZnSnO 3 estimated to be stable between pH 8 and 12 was used for synthesis of the particles. • ZnSnO 3 ·3H 2 O were formed during the precipitation of zinc stannate. - Abstract: Potential-pH diagram assisted-design for controlled precipitation is an attractive method to obtain engineered binary and ternary oxide particles. Aqueous synthesis conditions of zinc stannate (ZnSnO 3 ) particles at low temperature were formulated with the assistance of potential-pH diagram. The pH of a solution containing stoichiometric amounts of Zn 2+ and Sn 4+ was controlled for the precipitation in a one pot synthesis step at room temperature (25 °C). The effect of the concentration of the reactants on the particle size was studied by varying the concentration of the precursor (Zn 2+ + Sn 4+ ) solution. Scanning electron micrographs show that the particles are monodispersed micron sized cubes formed by the self-organization of nano-sized crystallites. The obtained microcubes characterized by X-ray Diffraction and thermo gravimetric analysis (TGA) show that the particles are in ZnSnO 3 ·3H 2 O form

  18. Ethanol electro-oxidation in alkaline medium using Pd/c and PdRh/C electrocatalysts prepared by electron beam irradiation

    International Nuclear Information System (INIS)

    Silva, Dionisio Furtunato da; Geraldes, Adriana Napoleao; Pino, Eddy Segura; Spinace, Estevam Vitorio; Oliveira Neto, Almir; Linardi, Marcelo

    2013-01-01

    In this study, carbon-supported Pd (Pd/C) and bimetallic PdRh (Pd:Rh 90:10 atomic ratio) (PdRh/C) electrocatalysts were prepared using electron beam irradiation. The morphology and composition of the obtained materials were characterized by Cyclic voltammetry (VC), Chronoamperometry (CA), Energy dispersive X-ray (EDX), X-ray Diffraction (XRD) and Thermo-gravimetric analysis (TGA). The catalytic activities of the electrocatalysts toward the ethanol electro-oxidation were evaluated in alkaline medium in a single alkaline direct ethanol fuel cell (ADEFC), in a range temperature of 50 to 85 deg C. The best performances were obtained at 85 deg C (25 mW.cm -2 ) and 75 deg C (38 mW.cm -2 ) for Pd/C and PdRh/C electrocatalysts, respectively. The XRD of the PdRh/C electrocatalyst showed the presence of Pd-rich (fcc) phase. CV and CA experiments showed that PdRh/C electrocatalyst demonstrated superior activity toward ethanol electro-oxidation at room temperature, compared to Pd/C electrocatalyst. (author)

  19. Dehydration of a layered double hydroxide-C2AH8

    International Nuclear Information System (INIS)

    Ukrainczyk, N.; Matusinovic, T.; Kurajica, S.; Zimmermann, B.; Sipusic, J.

    2007-01-01

    Thermal dehydration of dicalcium aluminate hydrate, C 2 AH 8 , has been investigated by simultaneous differential thermal and thermo gravimetric analysis (DTA/TGA), powder X-ray diffraction (XRD), temperature-dependent infrared spectroscopy (FT-IR), and BET method of surface area measurement. The temperature-dependent infrared measurements were studied by two-dimensional infrared (2D-IR) correlation spectroscopy. The structure of aluminum-oxide polyhedron, characterized by 27 Al solid state NMR spectrum method and FT-IR, shows tetrahedron and octahedron as the main forms of aluminum-oxide polyhedrons in C 2 AH 8 sample. From the results obtained a variety of structural transformations observed are explained as a consequence of the removal of loosely held interlayer water molecules at lower temperatures, followed by grafting process of the interlayer [Al(OH) 4 ] - anion. Structural model of a grafting process of the interlayer [Al(OH) 4 ] - tetrahedron onto hydroxylated octahedrons of [Ca 2 Al(OH) 6 ] + layers has been proposed in order to explain observed loss of one water molecule, shrinkage of interlayer spacing and qualitative changes of FT-IR spectra. At higher temperatures the dehydroxylation of the lattice and decomposition of the interlayer species occurs, yielding amorphous material that crystallizes into C 3 A and C 12 A 7 at 885 deg. C. Those findings provide improvement in the interpretation of thermo-analytical results of calcium aluminate cements (CAC) hydration products, and better understanding of CAC conversion process

  20. Da-KGM based GO-reinforced FMBO-loaded aerogels for efficient arsenic removal in aqueous solution.

    Science.gov (United States)

    Ye, Shuxin; Jin, Weiping; Huang, Qing; Hu, Ying; Li, Yan; Li, Jing; Li, Bin

    2017-01-01

    Composites based on deacetylated konjac glucomannan (Da-KGM) and graphene oxide (GO) aerogels with iron and manganese oxides (FMBO) for effective removal of arsenic from contaminated water. Da-KGM, which was used as supporting composite matrix here, were firstly treated with GO and loaded FMBO. The obtained Da-KGM/GO/FMBO composite aerogels were characterized by compression test, thermo gravimetric analysis (TGA), X-ray diffraction (XRD), fourier transform infrared spectroscopy (FTIR) and scanning electron microscope (SEM). The characteristic results showed that addition of GO exhibited enhanced mechanical properties towards Da-KGM aerogels. What's more, results of FTIR indicated the strong intermolecular hydrogen bond interaction between KGM and GO. Batch adsorption tests were used to evaluate arsenic removal capacity. Da-KGM/GO loaded FMBO composite aerogels exhibited high adsorption ability for arsenite [As(III)] and arsenate [As(V)]. The adsorption results showed that the arsenic for both arsenite [As(III)] and arsenate [As(V)] removal process followed a pseudo-second-order rate equation and Langmuir monolayer adsorption. The maximum As(III) and As(V) uptake capacity of Da-KGM/GO(10%)/FMBO composite aerogels reached 30.21mgg -1 and 12.08mgg -1 respectively according to Langmuir isotherm at pH 7 and 323K. Copyright © 2016 Elsevier B.V. All rights reserved.

  1. Efficacy of silver coated surgical sutures on bacterial contamination, cellular response and wound healing

    International Nuclear Information System (INIS)

    Gallo, Anna Lucia; Paladini, Federica; Romano, Alessandro; Verri, Tiziano; Quattrini, Angelo; Sannino, Alessandro; Pollini, Mauro

    2016-01-01

    The resistance demonstrated by many microorganisms towards conventional antibiotics has stimulated the interest in alternative antimicrobial agents and in novel approaches for prevention of infections. Silver, a natural braod-spectrum antimicrobial agent known since antiquity, has been widely employed in biomedical field due to its recognized antibacterial, antifungal and antiviral properties. In this work, antibacterial silver coatings were deposited on absorbable surgical sutures through the in situ photo-chemical deposition of silver clusters. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and thermo-gravimetric analysis (TGA) were performed in order to investigate the presence and distribution of the silver clusters on the substrate. The amounts of silver deposited and released by the silver treated sutures were calculated through Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS), and the results were related to the biodegradation of the material. The microbiological properties and the potential cytotoxicity of the silver-treated sutures were investigated in relation with hydrolysis experiments, in order to determine the effect of the degradation on antibacterial properties and biocompatibility. - Highlights: • The in situ photo-deposition of silver nano-coatings was used to develop silver treated PGLA sutures. • The silver particles deposited had good distribution and strong adhesion to the substrate. • The silver treated sutures demonstrated good biocompatibility and antibacterial capability. • The presence of silver promoted cell migration and proliferation in the wound area.

  2. Preparation and characterization of nano hydroxyapatite/polymeric composites materials. Part I

    Energy Technology Data Exchange (ETDEWEB)

    Mohamed, Khaled R., E-mail: kh_rezk1966@yahoo.com [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); El-Rashidy, Zenab M. [Biomaterials Dept., National Research Centre, Dokki, Cairo (Egypt); Salama, Aida A. [Biophysics Dept., Faulty of Science, El-Azhar Univ., Cairo (Egypt)

    2011-10-17

    Highlights: {yields} The formation and coating of CHA increased by increasing polymer content. {yields} The size of the prepared CHA was within nano-range scale. {yields} The composites had homogeneity and CHA formed within the polymeric matrix. - Abstract: The present study is focused on preparation of nano composite materials and the effect of citric acid on their different properties. The formation of nano HA and its interaction with chitosan (C), gelatin (G) polymers and citric acid (CA) materials were studied. The Fourier Transformed Infrared Spectroscopy (FT-IR), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), transmission electron microscope (TEM), and scanning electron microscope (SEM) were used to characterize these composite materials. The compressive strength (CS) was also measured to know the reinforcement of the prepared composites. The results show that carboxylic and amino groups play crucial role for HA formation on chitosan-gelatin polymeric matrix in the presence of citric acid (CA). The formation of nano HA particles and its average size of crystallite is increased with increase of CG content and decreased with addition of CA. Also, the HA formation and binding strength between its particles are improved into the composites especially with CA. The nano-composites containing the best ratio of nHA (70%) with CA (0.2 M) are promising for medical applications in the future.

  3. Synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted with mixed hollow sphere template method

    Science.gov (United States)

    Gopi, D.; Indira, J.; Kavitha, L.; Sekar, M.; Mudali, U. Kamachi

    Hydroxyapatite (HAP) is the main inorganic component of bone material and is widely used in various biomedical applications due to its excellent bioactivity and biocompatibility. In this paper, we have reported the synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted mixed template directed method. In this method glycine-acrylic acid (GLY-AA) hollow spheres were used as an organic template which could be prepared by mixing of glycine with acrylic acid. The as-synthesized HAP nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and tunnelling electron microscope (TEM) to investigate the nature of bonding, crystallinity, size and shape. The thermal stability of as-synthesized nanoparticles was also investigated by the thermo gravimetric analysis (TGA). The effect of ultrasonic irradiation time on the crystallinity and size of the HAP nanoparticles in presence of glycine-acrylic acid hollow spheres template were investigated. From the inspection of the above results it is confirmed that the crystallinity and size of the HAP nanoparticles decrease with increasing ultrasonic irradiation time. Hence the proposed synthesis strategy provides a facile pathway to obtain nano sized HAP with high quality, suitable size and morphology.

  4. Synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted with mixed hollow sphere template method.

    Science.gov (United States)

    Gopi, D; Indira, J; Kavitha, L; Sekar, M; Mudali, U Kamachi

    2012-07-01

    Hydroxyapatite (HAP) is the main inorganic component of bone material and is widely used in various biomedical applications due to its excellent bioactivity and biocompatibility. In this paper, we have reported the synthesis of hydroxyapatite nanoparticles by a novel ultrasonic assisted mixed template directed method. In this method glycine-acrylic acid (GLY-AA) hollow spheres were used as an organic template which could be prepared by mixing of glycine with acrylic acid. The as-synthesized HAP nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and tunnelling electron microscope (TEM) to investigate the nature of bonding, crystallinity, size and shape. The thermal stability of as-synthesized nanoparticles was also investigated by the thermo gravimetric analysis (TGA). The effect of ultrasonic irradiation time on the crystallinity and size of the HAP nanoparticles in presence of glycine-acrylic acid hollow spheres template were investigated. From the inspection of the above results it is confirmed that the crystallinity and size of the HAP nanoparticles decrease with increasing ultrasonic irradiation time. Hence the proposed synthesis strategy provides a facile pathway to obtain nano sized HAP with high quality, suitable size and morphology. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. Evaluation and characterization of ceramic membranes based on Pdms/SiC containing phosphotungstic acid as electrolytes for PEM-FC; Avaliacao e caracterizacao de membranas ceramicas condutoras a base de PDMS/SiC contendo acido fosfotungstico como eletrolito para PEM-FC

    Energy Technology Data Exchange (ETDEWEB)

    Lima, Marcelo de Oliveira; Guimaraes, Danilo Hansen; Boaventura Filho, Jaime Soares; Jose, Nadia Mamede [Universidade Federal da Bahia (IQ/UFBA), Salvador, BA (Brazil). Inst. de Quimica. Grupo de Energia e Ciencias dos Materiais; Barbosa, Diego Augusto Batista; Paschoal, Carlos William de Araujo [Universidade Federal do Maranhao (DF/UFMA), Sao Luis, MA (Brazil). Dept. de Fisica; Almeida, Rafael Mendonca; Tanaka, Auro Atsushi [Universidade Federal do Maranhao (DQ/UFMA), Sao Luis, MA (Brazil). Dept. de Quimica

    2009-07-01

    This work presents the development of membranes with potential use in Proton Exchange Fuel Cells (PEM-FC), consisting of hybrid materials based on poly(dimethylsiloxane), crosslinked with tetraethyl orthosilicate (TEOS), and reinforced with silicon carbide and phosphotungstic acid. The membrane series PDMS/TEOS/SiC/PWA were prepared by the reaction of PDMS and TEOS, 70/30% proportions in mass, catalyzed by dibutyltin dilaurate. SiC was incorporated in a 25% proportion, and PWA in varied proportions (5, 10, 15 and 20%), by weight. The membranes were characterized by Thermo-Gravimetric Analysis (TGA), X-ray Diffraction, Scanning Electron Microscopy and impedance spectroscopy. SiC and PWA addition to the membrane increased both structure organization and material crystallinity. The insertion of PWA provided an increase in the conductivity. However, maximum conductivity was obtained with concentration levels above 10%. The insertion of SiC associated with the PWA did not influence the conductivity for concentrations between 10 and 20%. (author)

  6. Evaluation and characterization of ceramic membranes based on Pdms/SiC containing phosphotungstic acid as electrolytes for PEM-FC

    International Nuclear Information System (INIS)

    Lima, Marcelo de Oliveira; Guimaraes, Danilo Hansen; Boaventura Filho, Jaime Soares; Jose, Nadia Mamede; Barbosa, Diego Augusto Batista; Paschoal, Carlos William de Araujo; Almeida, Rafael Mendonca; Tanaka, Auro Atsushi

    2009-01-01

    This work presents the development of membranes with potential use in Proton Exchange Fuel Cells (PEM-FC), consisting of hybrid materials based on poly(dimethylsiloxane), crosslinked with tetraethyl orthosilicate (TEOS), and reinforced with silicon carbide and phosphotungstic acid. The membrane series PDMS/TEOS/SiC/PWA were prepared by the reaction of PDMS and TEOS, 70/30% proportions in mass, catalyzed by dibutyltin dilaurate. SiC was incorporated in a 25% proportion, and PWA in varied proportions (5, 10, 15 and 20%), by weight. The membranes were characterized by Thermo-Gravimetric Analysis (TGA), X-ray Diffraction, Scanning Electron Microscopy and impedance spectroscopy. SiC and PWA addition to the membrane increased both structure organization and material crystallinity. The insertion of PWA provided an increase in the conductivity. However, maximum conductivity was obtained with concentration levels above 10%. The insertion of SiC associated with the PWA did not influence the conductivity for concentrations between 10 and 20%. (author)

  7. Modified solvothermal synthesis of cobalt ferrite (CoFe2O4) magnetic nanoparticles photocatalysts for degradation of methylene blue with H2O2/visible light

    Science.gov (United States)

    Kalam, Abul; Al-Sehemi, Abdullah G.; Assiri, Mohammed; Du, Gaohui; Ahmad, Tokeer; Ahmad, Irfan; Pannipara, M.

    2018-03-01

    Different grads of magnetic nano-scaled cobalt ferrites (CoFe2O4) photocatalysts were synthesized by modified Solvothermal (MST) process with and without polysaccharide. The indigenously synthesized photocatalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), thermo gravimetric analysis (TGA), Fourier transform infrared (FT-IR), UV-visible (UV-vis) spectroscopy and N2 adsorption-desorption isotherm method. The Fourier transform infrared spectroscopy study showed the Fe-O stretching vibration 590-619 cm-1, confirming the formation of metal oxide. The crystallite size of the synthesized photocatalysts was found in the range between 20.0 and 30.0 nm. The surface area of obtained magnetic nanoparticles is found to be reasonably high in the range of 63.0-76.0 m2/g. The results shown that only MST-2 is the most active catalyst for photo-Fenton like scheme for fast photodegradation action of methylene blue dye, this is possible due to optical band gap estimated of 2.65 eV. Captivatingly the percentage of degradation efficiency increases up to 80% after 140 min by using MST-2 photocatalyst. Photocatalytic degradation of methylene blue (MB) dye under visible light irradiation with cobalt ferrite magnetic nanoparticles followed first order kinetic constant and rate constant of MST-2 is almost 2.0 times greater than MST-1 photocatalyst.

  8. Separation of lignocelluloses from spent liquor of NSSC pulping process via adsorption.

    Science.gov (United States)

    Dashtban, Mehdi; Gilbert, Allan; Fatehi, Pedram

    2014-04-01

    Hemicelluloses and lignin present in the spent liquor (SL) of neutral sulfite semichemical (NSSC) pulping process can potentially be converted into value-added products such as furfural, hydroxymethylfurfural, levulinic acid, phenols and adhesives. However, the direct conversion of hemicelluloses and lignin of SL into value-added products is uneconomical due to the dilute nature of the SL. To have a feasible downstream process for utilizing lignocelluloses of SL, the lignocelluloses should initially be separated from the SL. In this study, an adsorption process (via applying activated carbon) was considered for isolating the dissolved lignin and hemicelluloses from the SL of an NSSC pulping process. Under the optimal conditions of pH, SL/AC weight ratio, time and temperature of 5.7, 30, 360 min and 30 °C, the maximum lignin and hemicellulose adsorptions were 0.33 and 0.25 g/g on AC. The chemical oxygen demand (COD) and turbidity of the SL were decreased by 11% and 39%, respectively, as a result of lignocellulose adsorption on AC. Also, the incineration behavior of the SL-treated AC was studied with a thermo-gravimetric analysis (TGA). Copyright © 2014 Elsevier Ltd. All rights reserved.

  9. MWCNTs-reinforced epoxidized linseed oil plasticized polylactic acid nanocomposite and its electroactive shape memory behaviour.

    Science.gov (United States)

    Alam, Javed; Alam, Manawwer; Raja, Mohan; Abduljaleel, Zainularifeen; Dass, Lawrence Arockiasamy

    2014-10-31

    A novel electroactive shape memory polymer nanocomposite of epoxidized linseed oil plasticized polylactic acid and multi-walled carbon nanotubes (MWCNTs) was prepared by a combination of solution blending, solvent cast technique, and hydraulic hot press moulding. In this study, polylactic acid (PLA) was first plasticized by epoxidized linseed oil (ELO) in order to overcome the major limitations of PLA, such as high brittleness, low toughness, and low tensile elongation. Then, MWCNTs were incorporated into the ELO plasticized PLA matrix at three different loadings (2, 3 and 5 wt. %), with the aim of making the resulting nanocomposites electrically conductive. The addition of ELO decreased glass transition temperature, and increased the elongation and thermal degradability of PLA, as shown in the results of differential scanning calorimetry (DSC), tensile test, and thermo gravimetric analysis (TGA). Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to observe surface morphology, topography, and the dispersion of MWCNTs in the nanocomposite. Finally, the electroactive-shape memory effect (electroactive-SME) in the resulting nanocomposite was investigated by a fold-deploy "U"-shape bending test. As per the results, the addition of both ELO and MWCNTs to PLA matrix seemed to enhance its overall properties with a great deal of potential in improved shape memory. The 3 wt. % MWCNTs-reinforced nanocomposite system, which showed 95% shape recovery within 45 s at 40 DC voltage, is expected to be used as a preferential polymeric nanocomposite material in various actuators, sensors and deployable devices.

  10. MWCNTs-Reinforced Epoxidized Linseed Oil Plasticized Polylactic Acid Nanocomposite and Its Electroactive Shape Memory Behaviour

    Directory of Open Access Journals (Sweden)

    Javed Alam

    2014-10-01

    Full Text Available A novel electroactive shape memory polymer nanocomposite of epoxidized linseed oil plasticized polylactic acid and multi-walled carbon nanotubes (MWCNTs was prepared by a combination of solution blending, solvent cast technique, and hydraulic hot press moulding. In this study, polylactic acid (PLA was first plasticized by epoxidized linseed oil (ELO in order to overcome the major limitations of PLA, such as high brittleness, low toughness, and low tensile elongation. Then, MWCNTs were incorporated into the ELO plasticized PLA matrix at three different loadings (2, 3 and 5 wt. %, with the aim of making the resulting nanocomposites electrically conductive. The addition of ELO decreased glass transition temperature, and increased the elongation and thermal degradability of PLA, as shown in the results of differential scanning calorimetry (DSC, tensile test, and thermo gravimetric analysis (TGA. Scanning electron microscopy (SEM and atomic force microscopy (AFM were used to observe surface morphology, topography, and the dispersion of MWCNTs in the nanocomposite. Finally, the electroactive-shape memory effect (electroactive-SME in the resulting nanocomposite was investigated by a fold-deploy “U”-shape bending test. As per the results, the addition of both ELO and MWCNTs to PLA matrix seemed to enhance its overall properties with a great deal of potential in improved shape memory. The 3 wt. % MWCNTs-reinforced nanocomposite system, which showed 95% shape recovery within 45 s at 40 DC voltage, is expected to be used as a preferential polymeric nanocomposite material in various actuators, sensors and deployable devices.

  11. Application of E{sub h}-pH diagram for room temperature precipitation of zinc stannate microcubes in an aqueous media

    Energy Technology Data Exchange (ETDEWEB)

    Al-Hinai, Ashraf T., E-mail: ashraf@squ.edu.om [Department of Chemistry, College of Science, Sultan Qaboos University, 123, Alkhoud (Oman); Al-Hinai, Muna H. [Department of Chemistry, College of Science, Sultan Qaboos University, 123, Alkhoud (Oman); Water Research Center, Sultan Qaboos University, 123, Alkhoud (Oman); Dutta, Joydeep, E-mail: dutta@squ.ed.om [Water Research Center, Sultan Qaboos University, 123, Alkhoud (Oman)

    2014-01-01

    Graphical abstract: - Highlights: • One pot aqueous synthesis of zinc stannate (ZnSnO{sub 3}) particles at low temperature. • Synthesis designed with the assistance of potential-pH diagram. • ZnSnO{sub 3} estimated to be stable between pH 8 and 12 was used for synthesis of the particles. • ZnSnO{sub 3}·3H{sub 2}O were formed during the precipitation of zinc stannate. - Abstract: Potential-pH diagram assisted-design for controlled precipitation is an attractive method to obtain engineered binary and ternary oxide particles. Aqueous synthesis conditions of zinc stannate (ZnSnO{sub 3}) particles at low temperature were formulated with the assistance of potential-pH diagram. The pH of a solution containing stoichiometric amounts of Zn{sup 2+} and Sn{sup 4+} was controlled for the precipitation in a one pot synthesis step at room temperature (25 °C). The effect of the concentration of the reactants on the particle size was studied by varying the concentration of the precursor (Zn{sup 2+} + Sn{sup 4+}) solution. Scanning electron micrographs show that the particles are monodispersed micron sized cubes formed by the self-organization of nano-sized crystallites. The obtained microcubes characterized by X-ray Diffraction and thermo gravimetric analysis (TGA) show that the particles are in ZnSnO{sub 3}·3H{sub 2}O form.

  12. Solar-assisted synthesis of ZnO nanoparticles using lime juice: a green approach

    Science.gov (United States)

    Hinge, Shruti P.; Pandit, Aniruddha B.

    2017-12-01

    Zinc oxide (ZnO) nanoparticles are those nanoparticles which have been synthesized in various morphologies and shapes. Their size and shape dependent properties and their applications in vivid sectors of science and technology make them interesting to synthesize. Present work reports a green method for ZnO nanoparticle synthesis using lime juice and sunlight. ZnO nanoparticles were also synthesized by conventionally used methods like heating, stirring or no heating and/or stirring. The nanoparticles were characterized using different techniques like UV-vis spectroscopy, scanning electron microscopy (SEM), x-ray diffraction (XRD) and dynamic light scattering (DLS). Thermo gravimetric analysis (TGA) was also carried out for the intermediate product to select the calcination temperature. Stoichiometric study reveals that the intermediate product formed is zinc citrate dihydrate. The synthesized calcined nanoparticles have good crystallinity, uniform shape, and high purity and were in the size range of 20-30 nm. These nanoparticles formed agglomerates of various shapes in the size range of 200-750 nm. This process is ecofriendly and is amiable for easy scale up.

  13. Synthesis and characterization of Zinc (II)-loaded Zeolite/Graphene oxide nanocomposite as a new drug carrier

    Energy Technology Data Exchange (ETDEWEB)

    Khatamian, M. [Inorganic Chemistry Department, Faculty of Chemistry, University of Tabriz, C.P. 51664 Tabriz (Iran, Islamic Republic of); Divband, B., E-mail: baharakdivband@yahoo.com [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Inorganic Chemistry Department, Faculty of Chemistry, University of Tabriz, C.P. 51664 Tabriz (Iran, Islamic Republic of); Farahmand-zahed, F. [Inorganic Chemistry Department, Faculty of Chemistry, University of Tabriz, C.P. 51664 Tabriz (Iran, Islamic Republic of)

    2016-09-01

    Current research has focused on the preparation of Zinc-clinoptilolite/Graphene Oxide (Zn-Clin/GO) hybrid nanostructure and investigating its biocompatibility for the first time. As prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Thermo gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). In order to use it as a drug carrier two important factors were investigated: cytocompatibility of nanocomposites and their drug loading capacity. The results showed that the prepared nanocomposite is cytocompatible and its high loading capacity and slow release performance for Doxorubicin (DOX), as a cancer drug, proved that it can be used as a drug carrier. At last in-vitro toxicity of DOX loaded nanocomposite was compared with pure DOX. - Graphical abstract: Biocompatible Zn-clinoptilolite/Graphene oxide hybrid nanostructure as in vitro drug delivery systems (DDS) was able to store and release substantial amounts of doxorubicin to the lung cancer cell lines. Display Omitted - Highlights: • Zn-Clin/GO nanocomposite as a new in vitro drug carrier with high loading capacity is synthesized. • Two synthesis methods (Microwave assisted hydrothermal method and Reflux method) are used. • All of the carriers (Zn-Clin, Zn-Clin/GO, GO) showed high biocompatibility.

  14. Structural Evolution under Reaction Conditions of Supported (NH43HPMo11VO40 Catalysts for the Selective Oxidation of Isobutane

    Directory of Open Access Journals (Sweden)

    Fangli Jing

    2015-03-01

    Full Text Available When using heteropolycompounds in the selective oxidation of isobutane to methacrolein and methacrylic acid, both the keeping of the primary structure (Keggin units and the presence of acidic sites are necessary to obtain the desired products. The structural evolution of supported (NH43HPMo11VO40 (APMV catalysts under preliminary thermal oxidizing and reducing treatments was investigated. Various techniques, such as TGA/DTG (Thermo-Gravimetric Analysis/Derivative Thermo-Gravimetry, H2-TPR (Temperature Programed Reduction, in situ XRD (X-Ray Diffraction and XPS (X-ray Photoelectron Spectroscopy, were applied. It was clearly evidenced that the thermal stability and the reducibility of the Keggin units are improved by supporting 40% APMV active phase on Cs3PMo12O40 (CPM. The partial degradation of APMV takes place depending on temperature and reaction conditions. The decomposition of ammonium cations (releasing NH3 leads to the formation of vacancies favoring cationic exchanges between vanadium coming from the active phase and cesium coming from the support. In addition, the vanadium expelled from the Keggin structure is further reduced to V4+, species, which contributes (with Mo5+ to activate isobutane. The increase in reducibility of the supported catalyst is assumed to improve the catalytic performance in comparison with those of unsupported APMV.

  15. A study of the accelerated zircaloy-4 oxidation reaction with H2O/H2 mixture gas

    International Nuclear Information System (INIS)

    Kim, Y. S.; Cho, I. J.

    2001-01-01

    A study of the Zircaloy-4 reaction with H 2 O/H 2 mixture gas is carried out by using TGA (Thermo Gravimetric Apparatus) to estimate the hydrogen embrittlement which can possibly cause catastrophic nuclear fuel rod failure. Reaction rates are measured as a function of H 2 /H 2 O. In the experiments reaction temperature is set at 500 .deg. C and total pressure of the mixture gas is maintained at 1 atm. Experimental results reveal that hydriding and oxidation reaction are competing. In early stage, hydriding kinetics is faster than oxidation, however, oxidant in H 2 O forms oxide on the surface as steam environment is maintained, thus, this growing oxide begins to protect the zirconium base metal against hydrogen permeation. In this second stage, the total kinetic rate follows enhanced oxidation kinetics. In the final stage, it is observed that the oxide is broken down and massive hydriding takes place through the mechanical defects in the oxide, whose kinetics is similar to pure hydriding kinetics. These results are confirmed by SEM and EDX analysis along with hydrogen concentration measurements

  16. Assembly of polypyrrole nanotube@MnO{sub 2} composites with an improved electrochemical capacitance

    Energy Technology Data Exchange (ETDEWEB)

    Ji, Jiayou; Zhang, Xiaoya; Liu, Jingya; Peng, Linfeng; Chen, Changlang; Huang, Zhiliang [School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Li, Liang, E-mail: msell08@163.com [School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Yu, Xianghua [School of Materials Science and Engineering, Wuhan Institute of Technology, Wuhan 430073 (China); Shang, Songmin, E-mail: shang.songmin@polyu.edu.hk [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China)

    2015-08-15

    Graphical abstract: - Highlights: • PPy nanotube@MnO{sub 2} composites have been prepared. • The thickness of MnO{sub 2} coating can be tuned by the concentration of KMnO{sub 4}. • Synergistic effect between PPy and MnO{sub 2} generates better capacitance performance. • The composites exhibit high specific capacitance and good cycle stability. - Abstract: A facile strategy is presented to fabricate polypyrrole nanotube@manganese dioxide (PPy@MnO{sub 2}) composites. The effect of KMnO{sub 4} concentration on the morphology and property of PPy@MnO{sub 2} composites is investigated. The microstrucutres and properties of the resulting PPy@MnO{sub 2} composites are characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy dispersive X-ray diffraction (EDX), X-ray diffraction (XRD), thermo-gravimetric analysis (TGA) and electrochemical measurements. The results indicate that the PPy@MnO{sub 2} composites possess high specific capacitance and good cyclic stability due to the coating of MnO{sub 2} onto PPy nanotubes. The specific capacitance of 403 F/g for the PPy@MnO{sub 2} composite is obtained from galvanostatic charge–discharge experiment at a current density of 1 A/g, exhibiting the potential application for supercapacitors.

  17. Preparation and characterization of molecularly-imprinted magnetic microspheres for adsorption of 2,4,6-trichlorophenol from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Ping; Pan, Jianming; Yan, Yongsheng [Jiangsu University, Zhenjiang (China); Sun, Qilong; Li, Jianfeng; Tan, Zhenjiang [Jilin Normal University, Siping (China)

    2015-04-15

    Magnetic molecularly imprinted microspheres (MMIS) were successfully prepared by suspension polymerization, and then as-prepared MMIS were used as adsorbents for selective recognition of 2,4,6-trichlorophenol (2,4,6-TCP) from aqueous solutions. The results composites were characterized by Fourier transform infrared (FT-IR), X-ray diffraction (XRD), thermo gravimetric analysis (TGA), scanning electron microscope (SEM) and vibrating sample magnetometer (VSM). The results demonstrated that MMIS possesses porous spherical morphology, and exhibits good thermal stability and magnetic property (Ms=10.14 emu g{sup -1}). Then batch mode of binding experiments was used to determine the equilibrium, kinetics and selectivity recognition. The Langmuir isotherm model fitted the equilibrium data better than did the Freundlich model, and the maximum adsorption capacity on MMIS was about 1.7 times higher than that of MNIS. Kinetics behaviors of MMIS were well described by the pseudo-second-order model. MMIS possessed outstanding selectivity recognition for 2,4,6-TCP in the presence of other competitive phenols (such as sesamol, 3-CP, thymol, 2,4-DCP). Furthermore, the reusability performance of MMIS showed about 17.53% loss after five repeated cycles. Finally, the MMIS were successfully applied to the selective extraction of 2,4,6-TCP from the vegetable samples.

  18. Preparations and thermal properties of micro- and nano-BN dispersed HDPE composites

    International Nuclear Information System (INIS)

    Jung, Jinwoo; Kim, Jaewoo; Uhm, Young Rang; Jeon, Jae-Kyun; Lee, Sol; Lee, Hi Min; Rhee, Chang Kyu

    2010-01-01

    The thermal properties of micro-sized boron nitride (BN) and nano-sized BN dispersed high density polyethylene (HDPE) composites were investigated by means of differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). Nano-BN powder was prepared by using a ball mill process before it was mixed in HDPE. To enhance the dispersivity of nano-BN in the polymer matrix, the surfaces of the nano-particles were treated with low density polyethylene (LDPE) which was dissolved in the cyclohexane solvent. The average particle sizes of micro-BN powder and LDPE coated nano-BN powder were ∼10 μm and ∼100 nm respectively. Dispersion and distribution of 5 wt% and 20 wt% of micro-BN and nano-BN respectively mixed in HDPE were observed by using the scanning electron microscope (SEM). According to the thermal analyses of pure HDPE, micro-BN/HDPE, and nano-BN/HDPE, 20 wt% nano-BN/HDPE composite shows the lowest enthalpy of fusion (ΔH m ) and better thermal conductive characteristics compared to the others.

  19. Ethanol electro-oxidation in alkaline medium using Pd/c and PdRh/C electrocatalysts prepared by electron beam irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Dionisio Furtunato da; Geraldes, Adriana Napoleao; Pino, Eddy Segura; Spinace, Estevam Vitorio; Oliveira Neto, Almir; Linardi, Marcelo, E-mail: dfsilva@ipen.br, E-mail: drinager@ig.com.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2013-07-01

    In this study, carbon-supported Pd (Pd/C) and bimetallic PdRh (Pd:Rh 90:10 atomic ratio) (PdRh/C) electrocatalysts were prepared using electron beam irradiation. The morphology and composition of the obtained materials were characterized by Cyclic voltammetry (VC), Chronoamperometry (CA), Energy dispersive X-ray (EDX), X-ray Diffraction (XRD) and Thermo-gravimetric analysis (TGA). The catalytic activities of the electrocatalysts toward the ethanol electro-oxidation were evaluated in alkaline medium in a single alkaline direct ethanol fuel cell (ADEFC), in a range temperature of 50 to 85 deg C. The best performances were obtained at 85 deg C (25 mW.cm{sup -2}) and 75 deg C (38 mW.cm{sup -2}) for Pd/C and PdRh/C electrocatalysts, respectively. The XRD of the PdRh/C electrocatalyst showed the presence of Pd-rich (fcc) phase. CV and CA experiments showed that PdRh/C electrocatalyst demonstrated superior activity toward ethanol electro-oxidation at room temperature, compared to Pd/C electrocatalyst. (author)

  20. Multilayer films of cationic graphene-polyelectrolytes and anionic graphene-polyelectrolytes fabricated using layer-by-layer self-assembly

    International Nuclear Information System (INIS)

    Rani, Adila; Oh, Kyoung Ah; Koo, Hyeyoung; Lee, Hyung jung; Park, Min

    2011-01-01

    Extremely thin sheets of carbon atoms called graphene have been predicted to possess excellent thermal properties, electrical conductivity, and mechanical stiffness. To harness such properties in composite materials for multifunctional applications, one would require the incorporation of graphene. In this study, new thin film composites were created using layer-by-layer (LBL) assembly of polymer-coated graphitic nanoplatelets. The positive and negative polyelectrolytes used to cover graphene sheets were poly allylamine hydrochloride (PAH) and poly sodium 4-styrenesulfonate (PSS). The synthesized poly allylamine hydrochloride-graphene (PAH-G) and poly sodium 4-styrenesulfonate-gaphene (PSS-G) were characterized by X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and thermo gravimetric analysis (TGA). The multilayer films created by spontaneous sequential adsorption of PAH-G and PSS-G were characterized by ultra violet spectroscopy (UV-vis), scanning electron microscopy (SEM), and AFM. The electrical conductivity of the graphene/polyelectrolyte multilayer film composites measured by the four-point probe method was 0.2 S cm -1 , which was sufficient for the construction of advanced electro-optical devices and sensors.

  1. Graphene/vanadium oxide nanotubes composite as electrode material for electrochemical capacitors

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Meimei [College of Chemistry, Xiangtan University, Xiangtan 411005 (China); College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Ge, Chongyong [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Hou, Zhaohui, E-mail: zhqh96@163.com [College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Cao, Jianguo [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); He, Binhong [College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Zeng, Fanyan [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); College of Chemistry and Chemical Engineering, Hunan Institute of Science and Technology, Yueyang 414006 (China); Kuang, Yafei, E-mail: yafeik@163.com [College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2013-07-15

    Graphene/vanadium oxide nanotubes (VOx-NTs) composite was successfully synthesized through the hydrothermal process in which acetone as solvent and 1-hexadecylamine (HDA) as structure-directing template were used. Morphology, structure and composition of the as-obtained composite were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, nitrogen isothermal adsorption/desorption and thermo gravimetric analysis (TGA). The composite with the VOx-NTs amount of 69.0 wt% can deliver a specific capacitance of 210 F/g at a current density of 1 A/g in 1 M Na{sub 2}SO{sub 4} aqueous solution, which is nearly twice as that of pristine graphene (128 F/g) or VOx-NTs (127 F/g), and exhibit a good performance rate. Compared with pure VOx-NTs, the cycle stability of the composite was also greatly improved due to the enhanced conductivity of the electrode and the structure buffer role of graphene.

  2. Synthesis and characterization of mesoporous silica modified with chiral auxiliaries for their potential application as chiral stationary phase.

    Science.gov (United States)

    Mayani, Vishal J; Abdi, S H R; Kureshy, R I; Khan, N H; Agrawal, Santosh; Jasra, R V

    2008-05-16

    Novel chiral stationary phase (CSP) based on chiral aminoalcohol immobilized on ordered mesoporous silica SBA-15 1a and standard silica 1b and their copper complexes 1a' and 1b', respectively, was synthesized as potential material for chiral ligand exchange chromatography (CLEC). Microanalysis, inductively coupled plasma spectroscopy (ICP), thermo-gravimetric analysis (TGA), cross polarized magic angle spinning (CP-MAS) (13)C NMR, Powder X-ray diffraction (PXRD), FTIR, N(2) adsorption isotherm, scanning electron microscopy (SEM), transmitted electron microscope (TEM) and solid reflectance UV-vis spectroscopy were used to characterize these materials. All the chiral stationary phases thus synthesized were used for the separation of different racemic compounds such as mandelic acid, 2,2'-dihydroxy-1,1'-binaphthalene BINOL) and diethyl tartrate by simple medium-pressure column chromatography. Successful enantio-separation of racemic mandelic acid was achieved with all the stationary phases but 1a and 1b gave slightly better resolution than their copper complexes 1a' and 1b'. Remarkably these materials are stable under the given experimental conditions and can be used repeatedly for several cycles of enantioresolution. It was observed that the porosity and surface area of the stationary phase play an important role in the chiral separation.

  3. Corrosion behavior of duplex polyaniline/epoxy coating on mild steel in 3% NaCl

    Directory of Open Access Journals (Sweden)

    Gvozdenović Milica M.

    2005-01-01

    Full Text Available The corrosion behavior and thermal stability of epoxy coatings electrodeposited on mild steel and on mild steel with electrochemically deposited polyaniline (PANI film were investigated by electrochemical impedance spectroscopy (EIS and thermo gravimetric analysis (TGA. The aim of the paper was to present new findings on the corrosion protection of mild steel by a duplex PANI/-epoxy coating in 3% NaCI solution and to determine the effect of thin PANI film on the protective properties of the coating. PANI film was deposited electrochemically on mild steel from an aqueous solution of 0.5 mol dm"3 sodium benzoate and 0.1 mol dm"3 aniline at a constant current density of 1.5 mA cm"2. Non-pigmented epoxy coatings on mild steel and on mild steel with PANI film were obtained by cathodic electrode position at constant voltage and stirring conditions. The resin concentration in the electrode position bath was 10 wt.% solid dispersion in water at pH 5.7. The applied voltage was 250 V, the temperature 26°C and the deposition time 3 min. It was shown that thin PANI film could be used to modify the surface of mild steel prior to epoxy coating deposition, due to the increased corrosion protection of a duplex PANI/epoxy coating comparing to an epoxy coating on mild steel in 3% NaCl solution.

  4. Development of Graft Copolymer Flocculant Based on Acrylamide and Acrylic Acid for the dewatering of coal

    International Nuclear Information System (INIS)

    Mahmoud, G.A.; Abdel Khalek, M.A

    2012-01-01

    Most coal preparation processes were carried out in water medium. The water content of coal product has a negative impact on handling and specific energy value. The moisture content may be attributed to the proportion of fine coal, which presents the greatest dewatering problem. A novel polymeric flocculant has been developed by graft copolymerization of acrylamide (AAm) with acrylic acid (AAc) using gamma irradiation technique. The grafted copol621621ymer P(AAm/AAc) was characterized by Fourier-transform infrared spectroscopy (FTIR), and thermo-gravimetric analysis (TGA). The effects of reaction parameters, such as total absorbed dose, and monomer concentration on grafting yield were investigated. The flocculation performance of the graft copolymer P(AAm/AAc) was investigated in coal suspension. It was observed that the grafting ratio was one of the key factors for the flocculating effects. The copolymers with various grafting ratios showed different flocculating properties. It was found that as the grafting ratio increased, the flocculating effect also increased. The flocculation performance of the grafted copolymer was better than that of the commercial flocculant, poly-acrylamide (Magnafloc 1011).

  5. Selective removal mercury (Ⅱ) from aqueous solution using silica aerogel modified with 4-amino-5-methyl-1,2,4-triazole-3(4H)-thion

    Energy Technology Data Exchange (ETDEWEB)

    Tadayon, Fariba; Saber-Tehrani, Mohammad; Motahar, Shiva [Islamic Azad University, Tehran (Iran, Islamic Republic of)

    2013-03-15

    Silica aerogel surface modifications with chelating agents for adsorption/removal of metal ions have been reported in recent years. This investigation reported the preparation of silica aerogel (SA) adsorbent coupled with metal chelating ligands of 4-amino-5-methyl-1,2,4-triazole-3(4H)-thion (AMTT) and its application for selective adsorption of Hg(Ⅱ) ion. The adsorbent was characterized by Fourier transform infrared spectra (FTIR) and thermo gravimetric analysis (TGA) measurements, nitrogen physisorption and scanning electron microscope (SEM). Optimal experimental conditions including pH, temperature, adsorbent dosage and contact time have been established. Langmuir and Freundlich isotherm models were applied to analyze the experimental data. The best interpretation for the experimental data given by the Langmuir isotherm equation and the maximum adsorption capacity of the modified silica gel and silica aerogel was 142.85 and 17.24mgg⌃(-1), respectively. Thermodynamic parameters such as Gibbs free energy (ΔG{sup o}), standard enthalpy (ΔH{sup o}) and entropy change (ΔS{sup o}) were investigated. The adsorbed Hg(Ⅱ) on the SA-AMTT adsorbents could be completely eluted by 1.0M KBr solution and recycled at least four times without the loss of adsorption capacity. The results of the present investigation illustrate that modified silica aerogel with AMTT could be used as an adsorbent for the effective removal of Hg(Ⅱ) ions from aqueous solution.

  6. Co-gasification of biomass and plastics: pyrolysis kinetics studies, experiments on 100 kW dual fluidized bed pilot plant and development of thermodynamic equilibrium model and balances.

    Science.gov (United States)

    Narobe, M; Golob, J; Klinar, D; Francetič, V; Likozar, B

    2014-06-01

    Thermo-gravimetric analysis (TGA) of volatilization reaction kinetics for 50 wt.% mixtures of plastics (PE) and biomass (wood pellets) as well as for 100 wt.% plastics was conducted to predict decomposition times at 850°C and 900°C using iso-conversional model method. For mixtures, agreement with residence time of dual fluidized bed (DFB) reactor, treated as continuous stirred-tank reactor (CSTR), was obtained at large conversions. Mono-gasification of plastics and its co-gasification with biomass were performed in DFB pilot plant, using olivine as heterogeneous catalyst and heat transfer agent. It was found that co-gasification led to successful thermochemical conversion of plastics as opposed to mono-gasification. Unknown flow rates were determined applying nonlinear regression to energy and mass balances acknowledging combustion fuel, air, steam, feedstock, but also exiting char, tar, steam and other components in DFB gasification unit. Water-gas shift equilibrium and methanol synthesis requirements were incorporated into gasification model, based on measurements. Copyright © 2014 Elsevier Ltd. All rights reserved.

  7. Effects of polyacrylic acid additive on barium sulfate particle morphology

    Energy Technology Data Exchange (ETDEWEB)

    Li, Jie; Liu, Dandan; Jiang, Hongkun; Wang, Jun; Jing, Xiaoyan; Chen, Rongrong [Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Zhu, Wenting [Department of Gastroenterology, Harbin Medical University Cancer Hospital, Harbin 150081 (China); Han, Shihui [Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); Li, Wanyou [College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001 (China); Wei, Hao, E-mail: weihao7512@126.com [Key Laboratory of Superlight Material and Surface Technology of Ministry of Education, College of Material Science and Chemical Engineering, Harbin Engineering University, Harbin 150001 (China); College of Power and Energy Engineering, Harbin Engineering University, Harbin 150001 (China)

    2016-06-01

    In this paper, polyacrylic acid (PAA) was used as a growth modifier to control micron-sized barium sulfate particles via a simple precipitation reaction between sodium sulfate and barium chloride at ambient temperature. The barium sulfate particles were exhibited various morphologies, such as monodisperse spheres, ellipsoids, rose-like aggregates, etc. To better understand the formation mechanisms of the various morphologies of these particles, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA) were employed. It was found that the PAA concentration, pH, and Ba{sup 2+} and SO{sub 4}{sup 2−} ions concentrations were the most important parameters controlling the morphology of the BaSO{sub 4} particles. These parameters affected the BaSO{sub 4} morphology by influencing the interactions between the PAA carboxyl groups and inorganic ions and the conformation change of the PAA molecular chains. Moreover, this work attempts to provide a preliminary understanding of the formation of the spherical BaSO{sub 4} particles with the randomly coiled conformation of the polymer. - Highlights: • Polyacrylic acid (PAA) was used as a growth modifier to control micron-sized BaSO{sub 4} particles. • The PAA/BaSO{sub 4} particles were exhibited various morphologies. • Provide a preliminary understanding of the formation mechanism of BaSO{sub 4} particles.

  8. Efficacy of silver coated surgical sutures on bacterial contamination, cellular response and wound healing

    Energy Technology Data Exchange (ETDEWEB)

    Gallo, Anna Lucia [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy); Paladini, Federica, E-mail: federica.paladini@unisalento.it [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy); Romano, Alessandro [Neuropathology Unit, Institute of Experimental Neurology and Division of Neuroscience, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132 Milan (Italy); Verri, Tiziano [Di.S.Te.B.A., University of Salento, Via per Monteroni, 73100 Lecce (Italy); Quattrini, Angelo [Neuropathology Unit, Institute of Experimental Neurology and Division of Neuroscience, IRCCS San Raffaele Scientific Institute, via Olgettina 60, 20132 Milan (Italy); Sannino, Alessandro; Pollini, Mauro [Department of Engineering for Innovation, University of Salento, Via Monteroni, 73100 Lecce (Italy)

    2016-12-01

    The resistance demonstrated by many microorganisms towards conventional antibiotics has stimulated the interest in alternative antimicrobial agents and in novel approaches for prevention of infections. Silver, a natural braod-spectrum antimicrobial agent known since antiquity, has been widely employed in biomedical field due to its recognized antibacterial, antifungal and antiviral properties. In this work, antibacterial silver coatings were deposited on absorbable surgical sutures through the in situ photo-chemical deposition of silver clusters. Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX) and thermo-gravimetric analysis (TGA) were performed in order to investigate the presence and distribution of the silver clusters on the substrate. The amounts of silver deposited and released by the silver treated sutures were calculated through Inductively Coupled Plasma-Mass Spectroscopy (ICP-MS), and the results were related to the biodegradation of the material. The microbiological properties and the potential cytotoxicity of the silver-treated sutures were investigated in relation with hydrolysis experiments, in order to determine the effect of the degradation on antibacterial properties and biocompatibility. - Highlights: • The in situ photo-deposition of silver nano-coatings was used to develop silver treated PGLA sutures. • The silver particles deposited had good distribution and strong adhesion to the substrate. • The silver treated sutures demonstrated good biocompatibility and antibacterial capability. • The presence of silver promoted cell migration and proliferation in the wound area.

  9. Synthesis of new thermo/pH sensitive drug delivery systems based on tragacanth gum polysaccharide.

    Science.gov (United States)

    Hemmati, Khadijeh; Ghaemy, Mousa

    2016-06-01

    In this study, new pH/temperature responsive graft copolymers were synthesized based on natural Tragacanth Gum (TG) carbohydrate and their controlled drug release was investigated. Amphiphilic alkyne terminated terpolymers (mPEG-PCL-PDMAEMA-CCH)s consist of methylated poly(ethyleneglycol) (mPEG), polycaprolactone (PCL), and poly(dimethylaminoethylmethacrylate) (PDMAEMA) were synthesized by using ring opening polymerization (ROP) and atom transfer radical polymerization (ATRP), and then were grafted onto azide-functionalized TG molecules by click chemistry. Different techniques such as FT-IR, (1)H NMR, gel permeation chromatography (GPC), thermo-gravimetrical analysis (TGA) and scanning electron microscopy (SEM) were used to verify the successful synthesis of graft copolymers (TG-g-PDMAEMA-PCL-mPEG)s. The graft copolymers self-assembled to single micelles in aqueous solution and upon pH changes further assembled into micellar aggregates. These micelles were used to prepare quercetin loaded nanocarriers by probe sonication method. Size and morphology of the nanocarriers were studied by dynamic light scattering (DLS) and SEM. The in vitro release behavior of quercetin from these micelles showed pH-dependence. The results showed that release profile of quercetin best followed the first order model. Copyright © 2016 Elsevier B.V. All rights reserved.

  10. Thermal compatibility of Sodium Nitrate/Expanded Perlite composite phase change materials

    International Nuclear Information System (INIS)

    Li, Ruguang; Zhu, Jiaoqun; Zhou, Weibing; Cheng, Xiaomin; Li, Yuanyuan

    2016-01-01

    Highlights: • Expanded Perlite/Sodium Nitrate composites hardly reported in thermal storage fields. • The thermal compatibility and adsorption of Expanded Perlite were investigated. • The thermo physic properties of composites were determined. • The thermal stability and long term enthalpy changes of composites were investigated. - Abstract: The present work focused on the preparation and characterization of a new thermal storage material applied in thermal energy management. X-ray diffraction (XRD) results showed that Expanded Perlite (EP) has a good thermal stability varying from 300 °C to 900 °C. Morphology of scanning electron microscopy (SEM) revealed that sodium nitrate is uniformly encapsulated and embedded in the three-dimensional network structure of EP. Fourier transform infrared (FT-IR) spectroscopy indicated that the EP is physically combined with the nitrate salt. Thermo-gravimetric analysis (TGA) and differential Scanning Calorimeter (DSC) indicated that the composites have good thermal stability. The adsorption capacity of loose EP was 213.21%. When the EP mass fraction varying from 10% to 60%, thermal conductivity decreased with the content of EP increased, and the highest thermal conductivity is 1.14 W (m K)"−"1 at 300 °C. SEM revealed the network structure of EP provided thermal conduction paths which enhanced the thermal conductivity of the composites. All results indicated that EP could be a good adsorption material to be applied in the thermal storage fields.

  11. A novel biochar from Manihot esculenta Crantz waste: application for the removal of Malachite Green from wastewater and optimization of the adsorption process.

    Science.gov (United States)

    Beakou, Buscotin Horax; El Hassani, Kaoutar; Houssaini, Mohammed Amine; Belbahloul, Mounir; Oukani, Elhassan; Anouar, Abdellah

    2017-09-01

    The adsorptive removal of Malachite Green (MG) by a novel biochar namely Cassava Rind Carbon (CRC) was studied in a batch system. Moreover, Box-Behnken Response Surface Methodology was used to optimize operating conditions of the adsorption process. Characterization was done by Thermo Gravimetric Analysis (TGA), Attenuated Total Reflectance Fourier Transform Infra-Red Spectroscopy (ATR/FTIR), Brunauer-Emmett-Teller (BET) surface area, Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD) and pH zero charge point (pH ZCP ). The pseudo-second-order model and Langmuir model provided the best fit for kinetic and isotherm, respectively. The maximum capacity of dye adsorbed was 932.98 mg/g at 25 °C. The influence of temperature, the mass of adsorbent and the concentration of dye was studied. The optimal amount of adsorbed MG was 1,363.58 mg/g corresponding to 50 °C, 5 mg of CRC and 150 mg/L of dye. According to the high performance exhibited by CRC in this study, Manihot esculenta Crantz waste can be used as a better and low-cost biomass for wastewater decolourization.

  12. Synthesis and characterization of Zinc (II)-loaded Zeolite/Graphene oxide nanocomposite as a new drug carrier

    International Nuclear Information System (INIS)

    Khatamian, M.; Divband, B.; Farahmand-zahed, F.

    2016-01-01

    Current research has focused on the preparation of Zinc-clinoptilolite/Graphene Oxide (Zn-Clin/GO) hybrid nanostructure and investigating its biocompatibility for the first time. As prepared samples were characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Thermo gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). In order to use it as a drug carrier two important factors were investigated: cytocompatibility of nanocomposites and their drug loading capacity. The results showed that the prepared nanocomposite is cytocompatible and its high loading capacity and slow release performance for Doxorubicin (DOX), as a cancer drug, proved that it can be used as a drug carrier. At last in-vitro toxicity of DOX loaded nanocomposite was compared with pure DOX. - Graphical abstract: Biocompatible Zn-clinoptilolite/Graphene oxide hybrid nanostructure as in vitro drug delivery systems (DDS) was able to store and release substantial amounts of doxorubicin to the lung cancer cell lines. Display Omitted - Highlights: • Zn-Clin/GO nanocomposite as a new in vitro drug carrier with high loading capacity is synthesized. • Two synthesis methods (Microwave assisted hydrothermal method and Reflux method) are used. • All of the carriers (Zn-Clin, Zn-Clin/GO, GO) showed high biocompatibility.

  13. Effects of porosity and temperature on oxidation behavior in air of selected nuclear graphites

    International Nuclear Information System (INIS)

    Chen Dongyue; Li Zhengcao; Miao Wei; Zhang Zhengjun

    2012-01-01

    Nuclear graphite endures gas oxidation in High Temperature Gas-cooled Reactor (HTGR), which may threaten the safety of reactor. To study the oxidation behavior of nuclear graphite, weight loss curve is usually measured through Thermo Gravimetric Analysis (TGA) method. In this work, three brands of nuclear graphite for HTGR (i.e., HSM-SC, IG-11, and NBG-18) are oxidized under 873 and 1073 K in open air, and their weight loss curves are obtained. The acceleration of oxidizing rate is observed for both HSM-SC and IG-11, and is attributed to the large porosity increase during oxidation process. For HSM-SC, the porosity increase comes from preferential binder oxidation, and thus its binder quality shall be improved to obtain better oxidation resistance. Temperature effects on oxidation for HSM-SC are also studied, which shows that oxidizing gas tends to be exhausted at graphite surface at high temperature instead of penetrate into the interior of bulk. (author)

  14. Graphene/vanadium oxide nanotubes composite as electrode material for electrochemical capacitors

    International Nuclear Information System (INIS)

    Fu, Meimei; Ge, Chongyong; Hou, Zhaohui; Cao, Jianguo; He, Binhong; Zeng, Fanyan; Kuang, Yafei

    2013-01-01

    Graphene/vanadium oxide nanotubes (VOx-NTs) composite was successfully synthesized through the hydrothermal process in which acetone as solvent and 1-hexadecylamine (HDA) as structure-directing template were used. Morphology, structure and composition of the as-obtained composite were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, nitrogen isothermal adsorption/desorption and thermo gravimetric analysis (TGA). The composite with the VOx-NTs amount of 69.0 wt% can deliver a specific capacitance of 210 F/g at a current density of 1 A/g in 1 M Na 2 SO 4 aqueous solution, which is nearly twice as that of pristine graphene (128 F/g) or VOx-NTs (127 F/g), and exhibit a good performance rate. Compared with pure VOx-NTs, the cycle stability of the composite was also greatly improved due to the enhanced conductivity of the electrode and the structure buffer role of graphene

  15. Thermodynamic study of ibuprofen by adiabatic calorimetry and thermal analysis

    Energy Technology Data Exchange (ETDEWEB)

    Xu Fen; Sun Lixian; Tan Zhicheng; Liang Jianguo; Li Ruilian

    2004-03-23

    Molar heat capacities of ibuprofen were precisely measured with a small sample precision automated adiabatic calorimeter over the temperature range from 80 to 400 K. The polynomial functions of C{sub p,m} (J K{sup -1} mol{sup -1}) versus T were established on the heat capacity measurements by means of the least fitting square method. The functions are as follows: for solid ibuprofen, at the temperature range of 79.105 K{<=}T{<=}333.297 K, C{sub p,m}=144.27+77.046X+3.5171X{sup 2}+10.925X{sup 3}+11.224X{sup 4}, where X=(T-206.201)/127.096; for liquid ibuprofen, at the temperature range of 353.406 K{<=}T{<=}378.785 K, C{sub p,m}=325.79+8.9696X-1.6073X{sup 2}-1.5145X{sup 3}, where X=(T-366.095)/12.690. A fusion transition at T=348.02 K was found from the C{sub p}-T curve. The molar enthalpy and entropy of the fusion transition were determined to be 26.65 kJ mol{sup -1} and 76.58 J mol{sup -1} K{sup -1}, respectively. The thermodynamic functions on the base of the reference temperature of 298.15 K, (H{sub T}-H{sub 298.15}) and (S{sub T}-S{sub 298.15}), were derived. Thermal characteristic of ibuprofen was studied by thermo-gravimetric analysis (TG-DTG) and differential scanning calorimeter (DSC). The temperature of fusion, the molar enthalpy and entropy of fusion obtained by DSC were well consistent with those obtained by adiabatic calorimeter. The evaporation process of ibuprofen was investigated further by TG and DTG, and the activation energy of the evaporation process was determined to be 80.3{+-}1.4 kJ mol{sup -1}.

  16. Thermal analysis of RFETS SS and C

    International Nuclear Information System (INIS)

    Korinko, P.S.

    2000-01-01

    In support of the gas generation test program (GGTP) for the 9975 shipping container, thermogravimetric analysis (TGA) was conducted. The objective of this activity was to determine the moisture content as an input to the gas generation model

  17. Sinter recrystalization and properties evaluation of glass-ceramic from waste glass bottle and magnesite for extended application

    Directory of Open Access Journals (Sweden)

    As'mau Ibrahim Gebi

    2016-12-01

    Full Text Available In a bid to address environmental challenges associated with the management of waste Coca cola glass bottle, this study set out to develop glass ceramic materials using waste coca cola glass bottles and magnesite from Sakatsimta in Adamawa state. A reagent grade chrome (coloring agent were used to modify the composition of the coca cola glass bottle;  X-ray fluorescence(XRF, X-ray diffraction (XRD and Thermo gravimetric analysis (TGA were used to characterize raw materials, four batches GC-1= Coca cola glass frit +1%Cr2O3, GC-2=97% Coca cola glass frit+ 2% magnesite+1%Cr2O3, GC-3=95% Coca cola glass frit+ 4%magnesite+1%Cr2O3, GC-4=93%Coca cola glass frit+ 6%magnesite+ 1%Cr2O3 were formulated and prepared. Thermal Gradient Analysis (TGA results were used as a guide in selection of three temperatures (7000C, 7500C and 8000C used for the study, three particle sizes -106+75, -75+53, -53µm and 2 hr sintering time were also used, the sinter crystallization route of glass ceramic production was adopted. The samples were characterized by X-ray diffraction (XRD and Scanning Electron Microscope (SEM, the density, porosity, hardness and flexural strength of the resulting glass ceramics were also measured. The resulting glass ceramic materials composed mainly of wollastonite, diopside and anorthite phases depending on composition as indicated by XRD and SEM, the density of the samples increased with increasing sintering temperature and decreasing particle size. The porosity is minimal and it decreases with increasing sintering temperature and decreasing particle size. The obtained glass ceramic materials possess appreciable hardness and flexural strength with GC-3 and GC-4 having the best combination of both properties.

  18. Modification of mechanical and thermal property of chitosan–starch blend films

    International Nuclear Information System (INIS)

    Tuhin, Mohammad O.; Rahman, Nazia; Haque, M.E.; Khan, Ruhul A.; Dafader, N.C.; Islam, Rafiqul; Nurnabi, Mohammad; Tonny, Wafa

    2012-01-01

    Chitosan–starch blend films (thickness 0.2 mm) of different composition were prepared by casting and their mechanical properties were studied. To improve the properties of chitosan–starch films, glycerol and mustard oil of different composition were used. Chitosan–starch films, incorporated with glycerol and mustard oil, were further modified with monomer 2-hydroxyethyl methacrylate (HEMA) using gamma radiation. The modified films showed improvement in both tensile strength and elongation at break than the pure chitosan–starch films. Water uptake of the films reduced significantly than the pure chitosan–starch film. Thermo gravimetric analysis (TGA) and dynamic mechanical analysis (DMA) showed that the modified films experience less thermal degradation than the pure films. Scanning electron microscopy (SEM) and FTIR were used to investigate the morphology and molecular interaction of the blend film, respectively. - Highlights: ► Chitosan–starch blend films (thickness 0.2 mm) were prepared by casting. ► To improve the properties of chitosan–starch films, glycerol and mustard oil of different composition were used. ► Chitosan–starch films, incorporated with glycerol and mustard oil, were further modified with monomer 2-hydroxyethyl methacrylate (HEMA) using gamma radiation. ► Properties of the modified films such as tensile strength, elongation at break, water uptake, TGA, DMA, SEM, FTIR were studied. ► Results indicate that modification of chitosan–starch film with mustard oil improved the properties of the blend films which could be further modified by HEMA using gamma radiation.

  19. Film processing characteristics of nano gold suitable for conductive application on flexible substrates

    International Nuclear Information System (INIS)

    Gupta, Ashish; Mandal, Saumen; Katiyar, Monica; Mohapatra, Yashowanta N.

    2012-01-01

    In spite of large number of studies and wide use of thiol encapsulated gold nanoparticles, the mechanism of their transformation to thin gold films for conductive applications is not as yet well understood. In order to understand and optimize the process of conversion of nanoparticle based ink for printing on plastic substrates, we synthesize and study thiolated Au nanoparticles, with average size of 2 nm, but with differing carbon chain length viz. butane (Au-C4), hexane (Au-C6) and octane (Au-C8). The link between the properties of Au nanoparticle and its transformation from nonconductive gold nanoparticle ink to conductive gold film is studied using a variety of techniques such as thermo gravimetric analysis (TGA), X-ray diffraction (XRD), atomic force microscopy, scanning electron microscopy and electrical conductivity measurements. A combined study of the shape of solution TGA and differential thermal analysis indicates occurrence of two distinct processes corresponding to disentanglement and debonding of thiol chains preceding the sintering of nanoparticles. The lowest sintering temperature is observed to be approximately 155 °C for chain length C4, and hence Au-C4 on polyethylene terephthalate substrates is studied in detail. Though XRD peaks of thick drop-cast films on polyethylene terephthalate substrate show increasing peak intensity with annealing temperature as expected, for spin coated thin films, in contrast, the peak intensity decreases with increase in annealing temperature. Electrical conductivity of the thin films is comparable to bulk gold after conversion, but decreases with increase in annealing temperature demonstrating the usefulness of insights obtained in the study for optimization of annealing schedules. - Highlights: ► Sintering of alkanethiol capped Au nanoparticles is chainlength dependent. ► Sintering temperature depends on thiol debonding. ► Butanethiol capped Au nanoparticles are the most suitable for flexible substrates.

  20. Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

    Directory of Open Access Journals (Sweden)

    Valeria Toffoli

    2013-12-01

    Full Text Available The design and characteristics of a micro-system for thermogravimetric analysis (TGA in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using milli-Q water and polyurethane microcapsule. The results demonstrated that our approach provides a faster and more sensitive TGA with respect to commercial systems.

  1. Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

    Science.gov (United States)

    Toffoli, Valeria; Carrato, Sergio; Lee, Dongkyu; Jeon, Sangmin; Lazzarino, Marco

    2013-01-01

    The design and characteristics of a micro-system for thermogravimetric analysis (TGA) in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using milli-Q water and polyurethane microcapsule. The results demonstrated that our approach provides a faster and more sensitive TGA with respect to commercial systems.

  2. PLA/CS/Nifedipine Nanocomposite Films: Properties and the In Vitro Release of Nifedipine

    Science.gov (United States)

    Trang, Nguyen Thi Thu; Chinh, Nguyen Thuy; Giang, Nguyen Vu; Thanh, Dinh Thi Mai; Lam, Tran Dai; Hoang, Thai

    2016-07-01

    The polylactic acid (PLA)/chitosan (CS) films containing a drug, nifedipine (NIF), in the presence of polyethylene oxide (PEO) as a compatibilizer were prepared by the solution method. This method has not been used to form films containing four components (PLA, CS, NIF, PEO) up to now. The CS, PEO, and NIF contents are 25 wt.%, 6-8 wt.%, and 10-50 wt.% in comparison with PLA weight, respectively. Fourier transform infrared spectroscopy (FTIR), thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), and field emission scanning electron microscopy (FESEM) were used to characterize the interactions, properties, and morphology of the PLA/CS/PEO/NIF films. The FTIR, TGA, and DSC results show that NIF carried by PLA/CS/PEO films and PLA, CS, NIF had better interaction and were more compatible when using PEO. The surface morphology of PLA/CS/PEO/NIF films was similar to that of PLA/CS/PEO films. Moreover, this was the first time drug loading and NIF release content from PLA/CS/PEO films were determined by the ultraviolet-visible (UV-Vis) spectroscopy method. The drug loading of PLA/CS/PEO/NIF films was from 80.99% to 93.61%. The in vitro NIF release studies were carried out in pH 2, 6.8, and 7.4 solutions corresponding to the pH of stomach, colon, and duodenum regions in the human body, respectively. The NIF release content in different pH solutions is in the order: pH 2 > pH 6.8 > pH 7.4 and increases when there is increasing NIF loading. The PLA/CS/PEO films are potential materials to apply for long-circulating systems for NIF delivery.

  3. Brain SPECT analysis using statistical parametric mapping in patients with transient global amnesia

    Energy Technology Data Exchange (ETDEWEB)

    Kim, E. N.; Sohn, H. S.; Kim, S. H; Chung, S. K.; Yang, D. W. [College of Medicine, The Catholic Univ. of Korea, Seoul (Korea, Republic of)

    2001-07-01

    This study investigated alterations in regional cerebral blood flow (rCBF) in patients with transient global amnesia (TGA) using statistical parametric mapping 99 (SPM99). Noninvasive rCBF measurements using 99mTc-ethyl cysteinate dimer (ECD) SPECT were performed on 8 patients with TGA and 17 age matched controls. The relative rCBF maps in patients with TGA and controls were compared. In patients with TGA, significantly decreased rCBF was found along the left superior temporal extending to left parietal region of the brain and left thalamus. There were areas of increased rCBF in the right temporal, right frontal region and right thalamus. We could demonstrate decreased perfusion in left cerebral hemisphere and increased perfusion in right cerebral hemisphere in patients with TGA using SPM99. The reciprocal change of rCBF between right and left cerebral hemisphere in patients with TGA might suggest that imbalanced neuronal activity between the bilateral hemispheres may be important role in the pathogenesis of the TGA. For quantitative SPECT analysis in TGA patients, we recommend SPM99 rather than the ROI method because of its definitive advantages.

  4. Brain SPECT analysis using statistical parametric mapping in patients with transient global amnesia

    International Nuclear Information System (INIS)

    Kim, E. N.; Sohn, H. S.; Kim, S. H; Chung, S. K.; Yang, D. W.

    2001-01-01

    This study investigated alterations in regional cerebral blood flow (rCBF) in patients with transient global amnesia (TGA) using statistical parametric mapping 99 (SPM99). Noninvasive rCBF measurements using 99mTc-ethyl cysteinate dimer (ECD) SPECT were performed on 8 patients with TGA and 17 age matched controls. The relative rCBF maps in patients with TGA and controls were compared. In patients with TGA, significantly decreased rCBF was found along the left superior temporal extending to left parietal region of the brain and left thalamus. There were areas of increased rCBF in the right temporal, right frontal region and right thalamus. We could demonstrate decreased perfusion in left cerebral hemisphere and increased perfusion in right cerebral hemisphere in patients with TGA using SPM99. The reciprocal change of rCBF between right and left cerebral hemisphere in patients with TGA might suggest that imbalanced neuronal activity between the bilateral hemispheres may be important role in the pathogenesis of the TGA. For quantitative SPECT analysis in TGA patients, we recommend SPM99 rather than the ROI method because of its definitive advantages

  5. Proximate Analysis of Coal

    Science.gov (United States)

    Donahue, Craig J.; Rais, Elizabeth A.

    2009-01-01

    This lab experiment illustrates the use of thermogravimetric analysis (TGA) to perform proximate analysis on a series of coal samples of different rank. Peat and coke are also examined. A total of four exercises are described. These are dry exercises as students interpret previously recorded scans. The weight percent moisture, volatile matter,…

  6. Covalent Surface Modifications of Carbon Nanotubes.

    Energy Technology Data Exchange (ETDEWEB)

    Pavia Sanders, Adriana [Sandia National Lab. (SNL-CA), Livermore, CA (United States); O' Bryan, Greg [Sandia National Lab. (SNL-CA), Livermore, CA (United States)

    2017-07-01

    A report meant to document the chemistries investigated by the author for covalent surface modification of CNTs. Oxidation, cycloaddition, and radical reactions were explored to determine their success at covalently altering the CNT surface. Characterization through infrared spectroscopy, Raman spectroscopy, and thermo gravimetric analysis was performed in order to determine the success of the chemistries employed. This report is not exhaustive and was performed for CNT surface modification exploration as it pertains to the "Next Gen" project.

  7. Heater-Integrated Cantilevers for Nano-Samples Thermogravimetric Analysis

    OpenAIRE

    Toffoli, Valeria; Carrato, Sergio; Lee, Dongkyu; Jeon, Sangmin; Lazzarino, Marco

    2013-01-01

    The design and characteristics of a micro-system for thermogravimetric analysis (TGA) in which heater, temperature sensor and mass sensor are integrated into a single device are presented. The system consists of a suspended cantilever that incorporates a microfabricated resistor, used as both heater and thermometer. A three-dimensional finite element analysis was used to define the structure parameters. TGA sensors were fabricated by standard microlithographic techniques and tested using mill...

  8. Quantitation of Surface Coating on Nanoparticles Using Thermogravimetric Analysis.

    Science.gov (United States)

    Dongargaonkar, Alpana A; Clogston, Jeffrey D

    2018-01-01

    Nanoparticles are critical components in nanomedicine and nanotherapeutic applications. Some nanoparticles, such as metallic nanoparticles, consist of a surface coating or surface modification to aid in its dispersion and stability. This surface coating may affect the behavior of nanoparticles in a biological environment, thus it is important to measure. Thermogravimetric analysis (TGA) can be used to determine the amount of coating on the surface of the nanoparticle. TGA experiments run under inert atmosphere can also be used to determine residual metal content present in the sample. In this chapter, the TGA technique and experimental method are described.

  9. Synthesis and X-ray Crystal Structure of a Stable cis-1,2-bis(diphenylphosphinoethene Monodentate Thiolate Platinum Complex and TGA Studies of its Precursors

    Directory of Open Access Journals (Sweden)

    Vaz Rodrigo H.

    2002-01-01

    Full Text Available The stable Pt(II complex [Pt(SPh2(dppen (4, (dppen, Ph2PCH=CHPPh2 was obtained from [PtCl(SPh2(SnPh3cod] (1 (cod = 1,5-cyclooctadiene by reductive elimination reaction of SnClPh3 and substitution of the cod ligand by the diphosphine, albeit in low yields. Yields of 80% were obtained when [Pt(SPh2cod] (3 was used as the starting material instead. The viability of these reactions was suggested by a TG study, performed on the starting materials. Complex 4 was characterized by multinuclear NMR (195Pt, 31P, ¹H and 13C and IR spectroscopies and elemental analysis. The molecular structure, solved by an X-ray diffraction study, exhibted a slightly distorted square-planar geometry and short C=C and Pt-P bond distances which were interpreted in terms of a p interaction between the double bond and the metal-ligand bond, as observed for other diphosphine compounds described previously.

  10. Formulation of SrO-MBCUS Agglomerates for Esterification and Transesterification of High FFA Vegetable Oil

    Directory of Open Access Journals (Sweden)

    Prashant Kumar

    2016-08-01

    Full Text Available Musa Balbisiana Colla Underground Stem (MBCUS catalyst was treated thermally mixing with 5:1 w/w of Strontium Oxide (SrO and the dynamic sites were reformed. The MBCUS-SrO showed sharper crystalline phases as evidence from XRD and TEM analysis. The composition and morphology were characterized from BET, SEM, EDX thermo-gravimetric analysis (TGA and XRF analysis. The optimization process for biodiesel production from Jatropha curcas L oil (JCO having high percentage of free fatty acids was carried out using orthogonal arrays adopting the Taguchi method. The linear equation was obtained from the analysis and subsequent biodiesel production (96% FAME was taken away from the JCO under optimal reaction conditions. The biodiesel so prepared had identical characteristics to that with MBCUS alone, but at a lower temperature (200˚C and internal vapour pressure. Metal leaching was much lower while reusability of the catalyst was enhanced. It was also confirmed that the particle size has little impact upon the conversion efficacy, but the basic active sites are more important. Copyright © 2016 BCREC GROUP. All rights reserved Received: 19th August 2015; Revised: 8th December 2015; Accepted: 1st January 2016 How to Cite: Kumar, P., Sarma, A.K., Bansal, A., Jha, M.K. (2016. Formulation of SrO-MBCUS Agglomerates for Esterification and Transesterification of High FFA Vegetable Oil. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 140-150 (doi:10.9767/bcrec.11.2.540.140-150 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.540.140-150

  11. A new water absorbable mechanical Epidermal skin equivalent: the combination of hydrophobic PDMS and hydrophilic PVA hydrogel.

    Science.gov (United States)

    Morales-Hurtado, M; Zeng, X; Gonzalez-Rodriguez, P; Ten Elshof, J E; van der Heide, E

    2015-06-01

    Research on human skin interactions with healthcare and lifestyle products is a topic continuously attracting scientific studies over the past years. It is possible to evaluate skin mechanical properties based on human or animal experimentation, yet in addition to possible ethical issues, these samples are hard to obtain, expensive and give rise to highly variable results. Therefore, the design of a skin equivalent is essential. This paper describes the design and characterization of a new Epidermal Skin Equivalent (ESE). The material resembles the properties of epidermis and is a first approach to mimic the mechanical properties of the human skin structure, variable with the length scale. The ESE is based on a mixture of Polydimethyl Siloxane (PDMS) and Polyvinyl Alcohol (PVA) hydrogel cross-linked with Glutaraldehyde (GA). It was chemically characterized by XPS and FTIR measurements and its cross section was observed by macroscopy and cryoSEM. Confocal Microscope analysis on the surface of the ESE showed an arithmetic roughness (Ra) between 14-16 μm and contact angle (CA) values between 50-60°, both of which are close to the values of in vivo human skins reported in the literature. The Equilibrium Water Content (ECW) was around 33.8% and Thermo Gravimetric Analysis (TGA) confirmed the composition of the ESE samples. Moreover, the mechanical performance was determined by indentation tests and Dynamo Thermo Mechanical Analysis (DTMA) shear measurements. The indentation results were in good agreement with that of the target epidermis reported in the literature with an elastic modulus between 0.1-1.5 MPa and it showed dependency on the water content. According to the DTMA measurements, the ESE exhibits a viscoelastic behavior, with a shear modulus between 1-2.5MPa variable with temperature, frequency and the hydration of the samples. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. A highly selective sorbent for removal of Cr(VI) from aqueous solutions based on Fe{sub 3}O{sub 4}/poly(methyl methacrylate) grafted Tragacanth gum nanocomposite: Optimization by experimental design

    Energy Technology Data Exchange (ETDEWEB)

    Sadeghi, Susan, E-mail: ssadeghi@birjand.ac.ir; Rad, Fatemeh Alavi; Moghaddam, Ali Zeraatkar

    2014-12-01

    In this work, poly(methyl methacrylate) grafted Tragacanth gum modified Fe{sub 3}O{sub 4} magnetic nanoparticles (P(MMA)-g-TG-MNs) were developed for the selective removal of Cr(VI) species from aqueous solutions in the presence of Cr(III). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), a vibrating sample magnetometer (VSM), and thermo-gravimetric analysis (TGA). A screening study on operational variables was performed using a two-level full factorial design. Based on the analysis of variance (ANOVA) with 95% confidence limit, the significant variables were found. The central composite design (CCD) has also been employed for statistical modeling and analysis of the effects and interactions of significant variables dealing with the Cr(VI) uptake process by the developed sorbent. The predicted optimal conditions were situated at a pH of 5.5, contact time of 3.4 h, and 3.0 g L{sup −1} dose. The Langmuir, Freundlich, and Temkin isotherm models were used to describe the equilibrium sorption of Cr(VI) by the absorbent, and the Langmuir isotherm showed the best concordance as an equilibrium model. The adsorption process was followed by a pseudo-second-order kinetic model. Thermodynamic investigations showed that the biosorption process was spontaneous and exothermic. - Highlights: • Fe3O4 nanoparticles were modified with Poly(methyl methacrylate) grafted Tragacanth gum • P(MMA)-g-TG -MNPs can preferentially adsorb Cr(VI) in the presence of Cr(III) • The effects of operational parameters on Cr(VI) removal were evaluated by RSM • Adsorption mechanism, kinetics, and isotherm have been explored • The sorbent was successfully used to remove Cr(VI) from different water samples.

  13. A highly selective sorbent for removal of Cr(VI) from aqueous solutions based on Fe3O4/poly(methyl methacrylate) grafted Tragacanth gum nanocomposite: Optimization by experimental design

    International Nuclear Information System (INIS)

    Sadeghi, Susan; Rad, Fatemeh Alavi; Moghaddam, Ali Zeraatkar

    2014-01-01

    In this work, poly(methyl methacrylate) grafted Tragacanth gum modified Fe 3 O 4 magnetic nanoparticles (P(MMA)-g-TG-MNs) were developed for the selective removal of Cr(VI) species from aqueous solutions in the presence of Cr(III). The sorbent was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), a vibrating sample magnetometer (VSM), and thermo-gravimetric analysis (TGA). A screening study on operational variables was performed using a two-level full factorial design. Based on the analysis of variance (ANOVA) with 95% confidence limit, the significant variables were found. The central composite design (CCD) has also been employed for statistical modeling and analysis of the effects and interactions of significant variables dealing with the Cr(VI) uptake process by the developed sorbent. The predicted optimal conditions were situated at a pH of 5.5, contact time of 3.4 h, and 3.0 g L −1 dose. The Langmuir, Freundlich, and Temkin isotherm models were used to describe the equilibrium sorption of Cr(VI) by the absorbent, and the Langmuir isotherm showed the best concordance as an equilibrium model. The adsorption process was followed by a pseudo-second-order kinetic model. Thermodynamic investigations showed that the biosorption process was spontaneous and exothermic. - Highlights: • Fe3O4 nanoparticles were modified with Poly(methyl methacrylate) grafted Tragacanth gum • P(MMA)-g-TG -MNPs can preferentially adsorb Cr(VI) in the presence of Cr(III) • The effects of operational parameters on Cr(VI) removal were evaluated by RSM • Adsorption mechanism, kinetics, and isotherm have been explored • The sorbent was successfully used to remove Cr(VI) from different water samples

  14. A new kinetic–mechanistic approach to elucidate electrooxidation of doxorubicin hydrochloride in unprocessed human fluids using magnetic graphene based nanocomposite modified glassy carbon electrode

    Energy Technology Data Exchange (ETDEWEB)

    Soleymani, Jafar [Hematology–Oncology Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Hasanzadeh, Mohammad, E-mail: Mhmmd_hasanzadeh@yahoo.com [Drug Applied Research Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Shadjou, Nasrin [Department of Nanochemistry, Nano Technology Center, and Faculty of Chemistry, Urmia University, Urmia (Iran, Islamic Republic of); Khoubnasab Jafari, Maryam [Tuberculosis and Lung Disease Research Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Gharamaleki, Jalil Vaez [Hematology–Oncology Research Center, Tabriz University of Medical Sciences, Tabriz 51664 (Iran, Islamic Republic of); Yadollahi, Mehdi [Department of Organic Chemistry, Faculty of Chemistry, Tabriz University, Tabriz (Iran, Islamic Republic of); Jouyban, Abolghasem [Pharmaceutical Analysis Research Center and Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of)

    2016-04-01

    A novel magnetic nanocomposite was synthesized in one step using polymerization of magnetic graph oxide grafted with chlorosulfonic acid (Fe{sub 3}O{sub 4}–GO–SO{sub 3}H) in the presence of polystyrene. The prepared magnetic nanocomposite was characterized using transmission electron microscopy (TEM), dynamic differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), (Thermo-gravimetric/differential thermal analysis (DTA)), Fourier transform infrared (FTIR), and UV–Vis techniques. Magnetic nanocomposite was casted on the surface of the glassy carbon electrode (PS/Fe{sub 3}O{sub 4}–GO–SO{sub 3}H/GCE) and used for the detection and determination of doxorubicin hydrochloride (DOX) in human biological fluids. The cyclic voltammograms (CVs) of the modified electrode in aqueous solution displayed a pair of well-defined, stable and irreversible reductive/oxidation redox systems. CV study indicated that the oxidation process is irreversible and adsorption controlled. In addition, CV results indicated that DOX is oxidized via two electrons and three protons which is an unusual approach for the oxidation of DOX. A sensitive and time-saving procedure was developed for the analysis of DOX in plasma, cerebrospinal fluid, and urine with detection limit of 4.9 nM, 14 nM and 4.3 nM, respectively. - Highlights: • A novel magneto-polymeric nanocomposite (PS/Fe{sub 3}O{sub 4}–GO–SO{sub 3}H) was synthesized. • Application of PS/Fe{sub 3}O{sub 4}–GO–SO{sub 3}H toward detection of DOX was investigated by electrochemistry. • A new kinetic–mechanistic approach to elucidate electrooxidation of DOX was obtained. • DOX was detected in plasma, cerebrospinal fluid, and urine.

  15. Investigation of Coating Performance of UV-Curable Hybrid Polymers Containing 1H,1H,2H,2H-Perfluorooctyltriethoxysilane Coated on Aluminum Substrates

    Directory of Open Access Journals (Sweden)

    Mustafa Çakır

    2017-03-01

    Full Text Available This study describes preparation and characterization of fluorine-containing organic-inorganic hybrid coatings. The organic part consists of bisphenol-A glycerolate (1 glycerol/phenol diacrylate resin and 1,6-hexanediol diacrylate reactive diluent. The inorganically rich part comprises trimethoxysilane-terminated urethane, 1H,1H,2H,2H-perfluorooctyltriethoxysilane, 3-(trimethoxysilyl propyl methacrylate and sol–gel precursors that are products of hydrolysis and condensation reactions. Bisphenol-A glycerolate (1 glycerol/phenol diacrylate resin was added to the inorganic part in predetermined amounts. The resultant mixture was utilized in the preparation of free films as well as coatings on aluminum substrates. Thermal and mechanical tests such as DSC, thermo-gravimetric analysis (TGA, and tensile and shore D hardness tests were performed on free films. Water contact angle, gloss, Taber abrasion test, cross-cut and tubular impact tests were conducted on the coated samples. SEM examination and EDS analysis was performed on the fractured surfaces of free films. The hybrid coatings on the aluminum sheets gave rise to properties such as moderately glossed surface; low wear rate and hydrophobicity. Tensile strength of free films increased with up to 10% inorganic content in the hybrid structure and this increase was approximately three times that of the control sample. As expected; the % strain value decreased by 17.3 with the increase in inorganic content and elastic modulus values increased by a factor of approximately 6. Resistance to ketone-based solvents was proven and an increase in hardness was observed as the ratio of the inorganic part increased. Samples which contain 10% sol–gel content were observed to provide optimal properties.

  16. Inhibitory effect of konjac glucomanan on pitting corrosion of AA5052 aluminium alloy in NaCl solution.

    Science.gov (United States)

    Zhang, Kegui; Yang, Wenzhong; Xu, Bin; Chen, Yun; Yin, Xiaoshuang; Liu, Ying; Zuo, Huanzhen

    2018-05-01

    A natural carbohydrate polymer, konjac glucomanan, has been extracted from commercial product and studied as a green corrosion inhibitor for AA5052 aluminium alloy in 3.5 wt% NaCl solution by high-performance gel permeation chromatography (GPC), thermo gravimetric analysis (TGA), Fourier-transform infrared (FT-IR) spectra, electrochemical measurement and surface characterization techniques. The results of GPC measurements suggest the weight-average molecular weight and the number-average molecular weight of KGM with 98.2% purity are 1.61 × 10 5  g/mol and 1.54 × 10 5  g/mol, respectively. Potentiodynamic polarization curves show konjac glucomanan behaves as a mixed-type inhibitor with dominant anodic effect and that its maximum efficiency at 200 ppm is 94%. Electrochemical impedance spectroscopy (EIS) studies reveal the resistance of oxide film is approximately two orders of magnitude greater than the resistance of adsorbed inhibitor layer and that they both increase with KGM concentration. Moreover, in-situ electrochemical noise (EN) detection demonstrates that the growth and propagation stages of the pitting corrosion germinating on metal surface are blocked by polysaccharide additive, which is confirmed by the surface analysis of aluminium alloy using scanning electron microscope (SEM), energy dispersive spectroscopy (EDS) and Raman spectroscopy. At last, it is found that the addition of KGM makes it harder for water droplet containing NaCl to wet the metallic substrate. Copyright © 2018 Elsevier Inc. All rights reserved.

  17. Carbon Dioxide Dry Reforming of Glycerol for Hydrogen Production using Ni/ZrO2 and Ni/CaO as Catalysts

    Directory of Open Access Journals (Sweden)

    Nur Nabillah Mohd Arif

    2016-08-01

    Full Text Available Glycerol, byproduct from the biodiesel production can be effectively utilized as the promising source of synthesis gas (syngas through a dry reforming reaction. Combination of these waste materials with greenhouse gases which is carbon dioxide (CO2 will help to reduce environmental problem such as global warming. This dry reforming reaction has been carried out in a fixed bed batch reactor at 700 °C under the atmospheric pressure for 3 hours. In this experiment, reforming reaction was carried out using Nickel (Ni as based catalyst and supported with zirconium (ZrO2 and calcium (CaO oxides. The catalysts were prepared by wet impregnation method and characterized using Bruanaer-Emmett-Teller (BET surface area, Scanning Electron Microscopy (SEM, X-ray Diffraction (XRD, Thermo Gravimetric (TGA, and Temperature Programmed Reduction (TPR analysis. Reaction studies show that 15% Ni/CaO give the highest hydrogen yield and glycerol conversion that peaked at 24.59% and 30.32%, respectively. This result is verified by XRD analysis where this catalyst shows low crystallinity and fine dispersion of Ni species resulted in high specific surface area which gives 44.93 m2/g that is validated by BET.  Copyright © 2016 BCREC GROUP. All rights reserved Received: 21st January 2016; Revised: 24th February 2016; Accepted: 29th February 2016 How to Cite: Arif, N.M.M., Vo, D.V.N., Azizan,M.T., Abidin S.Z. (2016. Carbon Dioxide Dry Reforming of Glycerol for Hydrogen Production using Ni/ZrO2 and Ni/CaO as Catalysts. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (2: 200-209 (doi:10.9767/bcrec.11.2.551.200-209 Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.2.551.200-209

  18. Synthesis, structural, optical and morphological characterization of hematite through the precipitation method: Effect of varying the nature of the base

    Science.gov (United States)

    Lassoued, Abdelmajid; Lassoued, Mohamed Saber; Dkhil, Brahim; Gadri, Abdellatif; Ammar, Salah

    2017-08-01

    Iron oxide (α-Fe2O3) nanoparticles were synthesized using the precipitation synthesis method focusing only on (FeCl3, 6H2O), NaOH, KOH and NH4OH as raw materials. The impact of varying the nature of the base on the crystalline phase, size and morphology of α-Fe2O3 products was explored. XRD spectra revealed that samples crystallize in the rhombohedral (hexagonal) system at 800 °C.The Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) were used to detect the morphology of synthesized nanoparticles and specify their sizes. However, the Fourier Transform Infra-Red (FT-IR) spectroscopy has permitted the observation of vibration band Fe-O. Raman spectroscopy was used not only to prove that we have synthesized hematite but also to identify their phonon modes. The Thermo Gravimetric Analysis (TGA) findings allow the thermal cycle determination of samples whereas Differential Thermal Analysis (DTA) findings allow the phase transition temperature identification. Besides, the optical investigation revealed that samples have an optical gap of about 2.1 eV. Findings highlight that the nature of the agent precipitant plays a significant role in the morphology of the products and the formation of the crystalline phase. Hematite synthesis with the base NH4OH brought about much stronger, sharper and wider diffraction peaks of α-Fe2O3. The morphology of samples are spherical with a size of about 61 nm while the size of the nanoparticles of hematite which we have synthesized with NaOH and KOH is respectively of the order of 82 and 79 nm.

  19. Preparation of PPy-Coated MnO2 Hybrid Micromaterials and Their Improved Cyclic Performance as Anode for Lithium-Ion Batteries.

    Science.gov (United States)

    Feng, Lili; Zhang, Yinyin; Wang, Rui; Zhang, Yanli; Bai, Wei; Ji, Siping; Xuan, Zhewen; Yang, Jianhua; Zheng, Ziguang; Guan, Hongjin

    2017-09-02

    MnO 2 @PPy core-shell micromaterials are prepared by chemical polymerization of pyrrole on the MnO 2 surface. The polypyrrole (PPy) is formed as a homogeneous organic shell on the MnO 2 surface. The thickness of PPy shell can be adjusted by the usage of pyrrole. The analysis of SEM, FT-IR, X-ray photoelectron spectroscopy (XPS), thermo-gravimetric analysis (TGA), and XRD are used to confirm the formation of PPy shell. Galvanostatic cell cycling and electrochemical impedance spectroscopy (EIS) are used to evaluate the electrochemical performance as anode for lithium-ion batteries. The results show that after formation of MnO 2 @PPy core-shell micromaterials, the cyclic performance as anode for lithium-ion batteries is improved. Fifty microliters of PPy-coated caddice-clew-like MnO 2 has the best cyclic performances as has 620 mAh g -1 discharge specific capacities after 300 cycles. As a comparison, the discharge specific capacity of bare MnO 2 materials falls to below 200 mAh g -1 after 10 cycles. The improved lithium-storage cyclic stability of the MnO 2 @PPy samples attributes to the core-shell hybrid structure which can buffer the structural expansion and contraction of MnO 2 caused by the repeated embedding and disengagement of Li ions and can prevent the pulverization of MnO 2 . This experiment provides an effective way to mitigate the problem of capacity fading of the transition metal oxide materials as anode materials for (lithium-ion batteries) LIBs.

  20. Synthesis of nano-hydroxyapatite (nHA) from waste mussel shells using a rapid microwave method

    Energy Technology Data Exchange (ETDEWEB)

    Shavandi, Amin, E-mail: amin.shavandi@postgrad.otago.ac.nz [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Bekhit, Alaa El-Din A. [Department of Food Sciences, University of Otago, Dunedin (New Zealand); Ali, Azam [Department of Applied Sciences, University of Otago, Dunedin (New Zealand); Sun, Zhifa [Department of Physics, University of Otago, Dunedin (New Zealand)

    2015-01-15

    Nano-crystalline hydroxyapatite (HA, Ca{sub 10}(PO{sub 4}){sub 6}(OH){sub 2}) was produced from waste mussel shells using a rapid microwave irradiation method. Mussel shells were converted to rod like nano-crystalline HA particles of 30–70 nm long using 0.1 M EDTA as a chelating agent for 30 min after an appropriate pre-treatment and an irradiation step in a microwave with a power of 1.1 kW. The produced HA was characterised using X-ray diffraction (XRD), scanning electron microscopy (SEM) coupled with energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), thermo gravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR) and inductively coupled plasma mass spectrometry (ICP-MS) to determine the morphology, particle size, crystal phases, elemental composition and thermal behaviour. Furthermore, to benchmark the synthesized HA obtained from mussel shells, it was compared with a commercially pure HA (Sigma–Aldrich). The thermal analysis showed that the synthesized HA has remarkable heat stability at 1000 °C, and the XRD and FTIR results showed a high purity of the synthesized HA powders. Compared to the conventional hydrothermal treatment, microwave-assisted method has the advantages of an increased rate of HA formation. The obtained HA have potential engineering applications as materials for bone-tissues. - Highlights: • Waste mussel shells were successfully converted to nano sized hydroxyapatite. • Microwave-assisted technique accelerated the conversion process. • The physicochemical properties of the produced hydroxyapatite are reported. • The prepared hydroxyapatite has nano sized particles of less than 100 nm.

  1. A Smart pH-responsive Nano-Carrier as a Drug Delivery System: A hybrid system comprised of mesoporous nanosilica MCM-41 (as a nano-container) & a pH-sensitive polymer (as smart reversible gatekeepers): Preparation, characterization and in vitro release studies of an anti-cancer drug.

    Science.gov (United States)

    Abbaszad Rafi, Abdolrahim; Mahkam, Mehrdad; Davaran, Soodabeh; Hamishehkar, Hamed

    2016-10-10

    A smart pH-responsive drug nano-carrier for controlled release of anti-cancer therapeutics was developed through a facile route. The nano-carrier consisted of two main parts: first, the nano-container part (that mesoporous silica nanoparticles (MCM-41) were selected for this aim); and second, pH-sensitive gatekeepers (that a pH-sensitive polymer, Poly4-vinylpyridine, played this role). In the first step, MCM-41 was synthesized via template assisted sol-gel process. In the second step, polymerizable functional groups were attached onto pore entrances rather than inside walls. In the third step, polymeric gatekeepers were introduced onto pore entrances via precipitation polymerization of functionalized MCM-41 with monomers. Different methods and analysis, such as Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Powder Diffraction (XRD), Thermo-Gravimetric Analysis (TGA), Energy-Dispersive X-ray Spectroscopy (EDX), Zeta Potentials, Dynamic Light Scattering (DLS), Field Emission Scanning Electron Microscope (FE-SEM) and Transmission Electron Microscopy (TEM) were employed to approve the successful attachment of gatekeepers. Furthermore, the release studies of methotroxate (MTX), an anti-cancer drug, were performed in different media (pH4, 5.8 and 7.4) at 37±1°C. The release profiles and curves show that the release rates are completely pH-dependent and it proceeds with a decrease in pH. It is concluded that in the higher pH the gatekeepers are in their close state, but they switch to the open state as a consequence of repulsive forces between positively charged polymer chains appear in acidic media. The results suggest that this smart nano-carrier can be considered as an appropriate candidate to deliver therapeutics to cancerous tissues. Copyright © 2016 Elsevier B.V. All rights reserved.

  2. Mechanical and thermal properties of bio-composites based on polypropylene reinforced with Nut-shells of Argan particles

    International Nuclear Information System (INIS)

    Essabir, H.; Hilali, E.; Elgharad, A.; El Minor, H.; Imad, A.; Elamraoui, A.; Al Gaoudi, O.

    2013-01-01

    Highlights: ► Nuts-shells of Argan particles are used as reinforcement in thermoplastic matrix. ► Particles are homogeneously dispersed and distributed within PP matrix. ► Mechanical and thermal characterization of the composite are applied. ► Particles–matrix adhesion was assured by the use of a SBS compatibilizer. - Abstract: This study treats the combined effects of both particle sizes and particle loading on the mechanical and thermal properties of polypropylene (PP) composites reinforced with Nut-shells of Argan (NA) particles. Three range sizes of particles were used in the presence of a polypropylene matrix grafted with 8 wt.% of a linear block copolymer based on styrene and butadiene coupling agent, to improve adhesion between the particles and the matrix. The composites were prepared through melt-blending using an internal mixer and the tensile specimens were prepared using a hot press molding machine. Scanning Electron Microscopy (SEM), Fourier Transform Infrared Spectroscopy (FT-IR), Thermo Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA) and tensile tests were employed to characterize the composites at 10, 15, 20 and 25 wt.% particle contents. Results show a clear improvement in Young’s modulus from the use of particles when compared to the neat PP, a gain of 42.65%, 26.7% and 2.9% at 20 wt.% particle loading, for particle range 1, 2 and 3, respectively. In addition a notable increase in the Young’s modulus was observed when decrease the particle size. The thermal stability of composites exhibits a slight decrease (256–230 °C) with particles loading from 10 to 25 wt.%, against neat PP (258 °C)

  3. Corundum nanostructure ITO film fabrication: An approach for physical properties assessment

    International Nuclear Information System (INIS)

    Solieman, A.; Zayed, M.K.; Alamri, S.N.; Al-Dahoudi, N.; Aegerter, M.A.

    2012-01-01

    Highlights: ► Transparent conductive nanostructured ITO films. ► Synthesis of ITO nanoparticles with corundum structure phase by the hydrothermal process. ► Deposition of nanoparticulate ITO films by spin coating technique. ► Curing of ITO films using UV irradiation at low temperatures. - Abstract: Corundum (hexagonal) structure indium tin oxide (h-ITO) nanocrystals have been synthesized by subjecting an aqueous solution of In and Sn chlorides (Sn/In 8 wt.%) to a hydrothermal process followed by annealing at 450 °C in forming gas for 1 h. The annealing temperature was selected based on thermo-gravimetric analysis (TGA) and differential thermal analysis (DTA) of the dried precipitated powder, which showed a stable weight and phase at temperatures above 420 °C. X-ray diffraction (XRD) patterns showed the formation of orthorhombic InOOH precipitates that is transformed, after annealing, into h-ITO nanocrystals with 32 nm average crystal size. For nanostructure film deposition, dispersed sols of the prepared nanocrystals were spun coated on glass substrates. The films were densified by UV irradiation, whilst four-probe method was used to measure its sheet resistance. A sheet resistance as low as 10.6 kΩ □ have been reached. Scanning electron microscope (SEM) and high resolution transmission electron microscope (HRTEM) showed that the films have high surface roughness and nanopores. The transmittance spectra of the nanostructure films were measured in the UV–vis–NIR wavelength range. In addition to its low resistivity, nanostructure h-ITO films showed a wide range of transparency.

  4. High temperature oxidation behaviour of nanostructured cermet coatings in a mixed CO2 – O2 environment

    International Nuclear Information System (INIS)

    Farrokhzad, M A; Khan, T I

    2014-01-01

    Nanostructured ceramic-metallic (cermet) coatings composed of nanosized ceramic particles (α-Al 2 O3 and TiO 2 ) dispersed in a nickel matrix were co-electrodeposited and then oxidized at 500°C, 600°C and 700°C in a mixed gas using a Thermo-gravimetric Analysis (TGA) apparatus. The mixed gas was composed of 15% CO 2 , 10% O 2 and 75% N 2 . This research investigates the effects of CO 2 and O 2 partial pressures on time-depended oxidation rates for coatings and compared them to the results from atmospheric oxidation under similar temperatures. The increase in partial pressure of oxygen due to the presence of CO 2 at each tested temperature was calculated and correlated to the oxidation rate of the coatings. The results showed that the presence of CO 2 in the system increased the oxidation rate of cermet coatings when compared to atmospheric oxidation at the same temperature. It was also shown that the increase in the oxidation rate is not the result of CO2 acting as the primary oxidant but as a secondary oxidant which results in an increase of the total partial pressure of oxygen and consequently higher oxidation rates. The WDS and XRD analyses results showed that the presence of nanosized TiO 2 particles in a nickel matrix can improve oxidation behaviour of the coatings by formation of Ni-Ti compounds on oxidizing surface of the coating which was found beneficiary in reducing the oxidation rates for cermet coatings

  5. Synthesis of a novel thermo/pH sensitive nanogel based on salep modified graphene oxide for drug release

    Energy Technology Data Exchange (ETDEWEB)

    Bardajee, Ghasem Rezanejade, E-mail: rezanejad@pnu.ac.ir; Hooshyar, Zari; Farsi, Maryam; Mobini, Akram; Sang, Golnaz

    2017-03-01

    Nanogels (NGs) are three-dimensional water soluble cross-linked hydrogel materials in the nanoscale size range with a high loading capacity for guest molecules and act as drug carrier systems. In the present work, a new type of thermo/pH sensitive NG comprising salep modified graphene oxide (SMGO) with branched N-isopropylacrylamide (NIPAM) and acrylic acid (AA) was prepared. The SMGO/P(NIPAM-co-AA) NGs exhibited nanoporous structure and spherical particles with diameters about 82 nm as characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The samples were also characterized by Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA) to further confirm about the formation of NGs. Doxorubicin (DOX) loaded SMGO/P(NIPAM-co-AA) NGs showed thermo/pH dependent releasing behavior: slow drug release at neutral pH and lower temperature but increased significantly in acidic pH and higher temperature, without any burst release. In addition, the NGs exhibited no effect on the cell viability in the tested concentration range up to 410 μg/mL and drug release systems enhanced toxicity to HeLa cells when compared to the equivalent dose of the free drug. Overall, our results put forth NGs as potential candidates in the development of a new nanocarrier for anti-cancer drug delivery. - Highlights: • A novel thermo/pH sensitive nanogels (NGs) was successfully synthesized. • NGs showed high loading capacity for DOX drug and slow drug release at neutral pH. • NGs exhibited no effect on the cell viability in the tested concentration range.

  6. Hybrid scaffolds based on PLGA and silk for bone tissue engineering.

    Science.gov (United States)

    Sheikh, Faheem A; Ju, Hyung Woo; Moon, Bo Mi; Lee, Ok Joo; Kim, Jung-Ho; Park, Hyun Jung; Kim, Dong Wook; Kim, Dong-Kyu; Jang, Ji Eun; Khang, Gilson; Park, Chan Hum

    2016-03-01

    Porous silk scaffolds, which are considered to be natural polymers, cannot be used alone because they have a long degradation rate, which makes it difficult for them to be replaced by the surrounding tissue. Scaffolds composed of synthetic polymers, such as PLGA, have a short degradation rate, lack hydrophilicity and their release of toxic by-products makes them difficult to use. The present investigations aimed to study hybrid scaffolds fabricated from PLGA, silk and hydroxyapatite nanoparticles (Hap NPs) for optimized bone tissue engineering. The results from variable-pressure field emission scanning electron microscopy (VP-FE-SEM), equipped with EDS, confirmed that the fabricated scaffolds had a porous architecture, and the location of each component present in the scaffolds was examined. Contact angle measurements confirmed that the introduction of silk and HAp NPs helped to change the hydrophobic nature of PLGA to hydrophilic, which is the main constraint for PLGA used as a biomaterial. Thermo-gravimetric analysis (TGA) and FT-IR spectroscopy confirmed thermal decomposition and different vibrations caused in functional groups of compounds used to fabricate the scaffolds, which reflected improvement in their mechanical properties. After culturing osteoblasts for 1, 7 and 14 days in the presence of scaffolds, their viability was checked by MTT assay. The fluorescent microscopy results revealed that the introduction of silk and HAp NPs had a favourable impact on the infiltration of osteoblasts. In vivo experiments were conducted by implanting scaffolds in rat calvariae for 4 weeks. Histological examinations and micro-CT scans from these experiments revealed beneficial attributes offered by silk fibroin and HAp NPs to PLGA-based scaffolds for bone induction. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Physico-chemical characteristics of eight different biomass fuels and comparison of combustion and emission results in a small scale multi-fuel boiler

    International Nuclear Information System (INIS)

    Forbes, E.G.A.; Easson, D.L.; Lyons, G.A.; McRoberts, W.C.

    2014-01-01

    Highlights: • Physical parameters of the eight biomass fuels examined were all different. • Significant differences were found in Proximate, Ultimate and TGA results. • Energy outputs were not proportionate to dry matter energy content. • Highest flue ash production from fuels with highest fines content. • Flue gas emissions varied significantly, NOx levels correlated with fuel N content. - Abstract: This study describes the results from the investigation of 7 different biomass fuel types produced on a farm, and a commercial grade wood pellet, for their physical, chemical, thermo-gravimetric and combustion properties. Three types of short rotation coppice (SRC) willow, two species of conifers, forest residues (brash), commercially produced wood-pellets and a chop harvested energy grass crop Miscanthus giganteus spp., (elephant grass) were investigated. Significant differences (p < 0.05) were found in most of the raw fuel parameters examined using particle distribution, Thermogravimetric, Ultimate and Proximate analysis. Combustion tests in a 120 kW multi-fuel boiler revealed differences, some significant, in the maximum output, energy conversion efficiency, gaseous emission profiles and ash residues produced from the fuels. It was concluded that some of the combustion results could be directly correlated with the inherent properties of the different fuels. Ash production and gaseous emissions were the aspects of performance that were clearly and significantly different though effects on energy outputs were more varied and less consistent. The standard wood pellet fuel returned the best overall performance and miscanthus produced the largest amount of total ash and clinker after combustion in the boiler

  8. Nanostructure investigation of magnetic nanomaterial Ni0.5Zn0.3Cu0.2Fe2O4 synthesized by sol-gel method

    International Nuclear Information System (INIS)

    Pransisco, Prengki; Shafie, Afza; Guan, Beh Hoe

    2015-01-01

    Magnetic nanomaterial Ni 0.5 Zn 0.3 Cu 0.2 Fe 2 O 4 was successfully prepared by using sol-gel method. Heat treatment on material is always giving defect on properties of material. This paper investigates the effect of heat treatment on nanostructure of magnetic nanomaterial Ni 0.5 Zn 0.3 Cu 0.2 Fe 2 O 4 . According to thermo gravimetric analysis (TGA) that after 600°C there is no more weight loss detected and it was decided as minimum calcination temperature. Intensity, crystallite size, structure, lattice parameter and d-spacing of the material were investigated by using X-ray diffraction (XRD). High resolution transmission electron microscope (HRTEM) was used to examine nanostructure, nanosize, shape and distribution particle of magnetic material Ni 0.5 Zn 0.3 Cu 0.2 Fe 2 O 4 and variable pressure field emission scanning electron microscope (VP-FESEM) was used to investigate the surface morphology and topography of the material. The XRD result shows single-phase cubic spinel structure with average crystallite size in the range of 25.6-95.9 nm, the value of the intensity of the material was increased with increasing temperature, and followed by lattice parameter was increased with increasing calcination temperature, value of d-spacing was relatively decreased with accompanied increasing temperature. From HRTEM result the distribution of particles was tend to be agglomerates with particle size of 7.8-17.68 nm. VP-FESEM result shows that grain size of the material increases with increasing calcination temperature and the surface morphology shows that the material is in hexagonal shape and it was also proved by mapping result which showing the presence each of constituents inside the compound

  9. Nanostructure investigation of magnetic nanomaterial Ni{sub 0.5}Zn{sub 0.3}Cu{sub 0.2}Fe{sub 2}O{sub 4} synthesized by sol-gel method

    Energy Technology Data Exchange (ETDEWEB)

    Pransisco, Prengki, E-mail: prengkipransisco@gmail.com [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia); Badan Lingkungan Hidup Derah Kabupaten Empat Lawang South of Sumatera (Indonesia); Shafie, Afza, E-mail: afza@petronas.com.my; Guan, Beh Hoe, E-mail: beh.hoeguan@petronas.com.my [Department of Fundamental and Applied Sciences, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, 31750 Tronoh, Perak (Malaysia)

    2015-07-22

    Magnetic nanomaterial Ni{sub 0.5}Zn{sub 0.3}Cu{sub 0.2}Fe{sub 2}O{sub 4} was successfully prepared by using sol-gel method. Heat treatment on material is always giving defect on properties of material. This paper investigates the effect of heat treatment on nanostructure of magnetic nanomaterial Ni{sub 0.5}Zn{sub 0.3}Cu{sub 0.2}Fe{sub 2}O{sub 4}. According to thermo gravimetric analysis (TGA) that after 600°C there is no more weight loss detected and it was decided as minimum calcination temperature. Intensity, crystallite size, structure, lattice parameter and d-spacing of the material were investigated by using X-ray diffraction (XRD). High resolution transmission electron microscope (HRTEM) was used to examine nanostructure, nanosize, shape and distribution particle of magnetic material Ni{sub 0.5}Zn{sub 0.3}Cu{sub 0.2}Fe{sub 2}O{sub 4} and variable pressure field emission scanning electron microscope (VP-FESEM) was used to investigate the surface morphology and topography of the material. The XRD result shows single-phase cubic spinel structure with average crystallite size in the range of 25.6-95.9 nm, the value of the intensity of the material was increased with increasing temperature, and followed by lattice parameter was increased with increasing calcination temperature, value of d-spacing was relatively decreased with accompanied increasing temperature. From HRTEM result the distribution of particles was tend to be agglomerates with particle size of 7.8-17.68 nm. VP-FESEM result shows that grain size of the material increases with increasing calcination temperature and the surface morphology shows that the material is in hexagonal shape and it was also proved by mapping result which showing the presence each of constituents inside the compound.

  10. Synthesis and application of a novel nanostructured ion-imprinted polymer for the preconcentration and determination of thallium(I) ions in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Fayazi, M., E-mail: maryamfayazi64@yahoo.com [Young Researchers and Elite Club, Kerman Branch, Islamic Azad University, Kerman (Iran, Islamic Republic of); Ghanei-Motlagh, M. [Young Researchers and Elite Club, Kerman Branch, Islamic Azad University, Kerman (Iran, Islamic Republic of); Taher, M.A. [Department of Chemistry, Faculty of Sciences, Shahid Bahonar University of Kerman, Kerman (Iran, Islamic Republic of); Ghanei-Motlagh, R. [Department of Pathobiology, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of); Salavati, M.R. [Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad (Iran, Islamic Republic of)

    2016-05-15

    Highlights: • A novel nanostructured thallium(I)-imprinted polymer was evaluated for trace detection of Tl(I). • The prepared sorbent displayed rapid extraction rate, high sensitivity and good reproducibility. • The proposed methodology was applied for quantification of Tl(I) in different water samples. - Abstract: A novel synthesized nanostructured ion-imprinted polymer (IIP) was investigated for the determination of trace amount of thallium(I). For this purpose, the thallium(I) IIP particles were synthesized using methacrylic acid (MAA) as the functional monomer, ethylene glycol dimethacrylate (EGDMA) as the cross-linker, methyl-2-[2-(2-2-[2-(methoxycarbonyl) phenoxy] ethoxyethoxy) ethoxy] benzoate as the chelating agent and 2,2-azobisisobutyronitrile (AIBN) as the initiator. The prepared IIP particles were characterized by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA). Various experimental factors such as pH, the amount of IIP particles, sorption and desorption time, sample volume, elution condition, and potentially interfering ions systematically examined. Under the optimum conditions, a sensitive response to Tl(I) within a wide concentration range (0.05–18 μg L{sup −1}) was achieved. The limit of detection (LOD, 3S{sub b}/m) was 6.3 ng L{sup −1}. The maximum adsorption capacity of the novel imprinted adsorbent for Tl(I) was calculated to be 18.3 mg g{sup −1}. The relative standard deviation (RSD) for eight replicate detections of 0.1 μg L{sup −1} of thallium(I) was found to be 4.0%. An enrichment factor (EF) of 100 was obtained by this method. The proposed technique was successfully applied to monitoring thallium in different water samples and the certified reference material.

  11. Modified solvothermal synthesis of cobalt ferrite (CoFe2O4 magnetic nanoparticles photocatalysts for degradation of methylene blue with H2O2/visible light

    Directory of Open Access Journals (Sweden)

    Abul Kalam

    2018-03-01

    Full Text Available Different grads of magnetic nano-scaled cobalt ferrites (CoFe2O4 photocatalysts were synthesized by modified Solvothermal (MST process with and without polysaccharide. The indigenously synthesized photocatalysts were characterized by means of X-ray diffraction (XRD, scanning electron microscopy (SEM, transmission electron microscopy (TEM, high-resolution transmission electron microscopy (HRTEM, thermo gravimetric analysis (TGA, Fourier transform infrared (FT-IR, UV–visible (UV–vis spectroscopy and N2 adsorption–desorption isotherm method. The Fourier transform infrared spectroscopy study showed the Fe-O stretching vibration 590–619 cm−1, confirming the formation of metal oxide. The crystallite size of the synthesized photocatalysts was found in the range between 20.0 and 30.0 nm. The surface area of obtained magnetic nanoparticles is found to be reasonably high in the range of 63.0–76.0 m2/g. The results shown that only MST-2 is the most active catalyst for photo-Fenton like scheme for fast photodegradation action of methylene blue dye, this is possible due to optical band gap estimated of 2.65 eV. Captivatingly the percentage of degradation efficiency increases up to 80% after 140 min by using MST-2 photocatalyst. Photocatalytic degradation of methylene blue (MB dye under visible light irradiation with cobalt ferrite magnetic nanoparticles followed first order kinetic constant and rate constant of MST-2 is almost 2.0 times greater than MST-1 photocatalyst. Keywords: Cobalt ferrite, Photocatalysis, Kinetics, Optical properties, Surface area studies

  12. Characterization of uranium corrosion products involved in the March 13, 1998 fuel manufacturing facility pyrophoric event

    International Nuclear Information System (INIS)

    Totemeier, T.C.

    1999-01-01

    Uranium metal corrosion products from ZPPR fuel plates involved in the March 13, 1998 pyrophoric event in the Fuel Manufacturing Facility at Argonne National Laboratory-West were characterized using thermo-gravimetric analysis, X-ray diffraction, and BET gas sorption techniques. Characterization was performed on corrosion products in several different conditions: immediately after separation from the source metal, after low-temperature passivation, after passivation and extended vault storage, and after burning in the pyrophoric event. The ignition temperatures and hydride fractions of the corrosion product were strongly dependent on corrosion extent. Corrosion products from plates with corrosion extents less than 0.7% did not ignite in TGA testing, while products from plates with corrosion extents greater than 1.2% consistently ignited. Corrosion extent is defined as mass of corrosion products divided by the total mass of uranium. The hydride fraction increased with corrosion extent. There was little change in corrosion product properties after low-temperature passivation or vault storage. The burned products were not reactive and contained no hydride; the principal constituents were UO 2 and U 3 O 7 . The source of the event was a considerable quantity of reactive hydride present in the corrosion products. No specific ignition mechanism could be conclusively identified. The most likely initiator was a static discharge in the corrosion product from the 14th can as it was poured into the consolidation can. The available evidence does not support scenarios in which the powder in the consolidation can slowly self-heated to the ignition point, or in which the powder in the 14th can was improperly passivated

  13. Preparation and characterization of sulfonated amine-poly(ether sulfone)s for proton exchange membrane fuel cell

    Energy Technology Data Exchange (ETDEWEB)

    Seo, Dong-Wan; Lim, Young-Don; Lee, Soon-Ho; Jeong, Young-Gi; Kim, Whan-Gi [Department of Applied Chemistry/RIC-ReSEM, Konkuk University, Chungju-si, Chungbuk 380-701 (Korea, Republic of); Hong, Tae-Whan [Department of Materials Sci and Engineering/RIC-ReSEM, Chungju National University, Chungju, Chungbuk (Korea, Republic of)

    2010-12-15

    Sulfonated amine-poly(ether sulfone)s (S-APES)s were prepared by nitration, reduction and sulfonation of poly(ether sulfone) (ultrason {sup registered} -S6010). Poly(ether sulfone) was reacted with ammonium nitrate and trifluoroacetic anhydride to produce the nitrated poly(ether sulfone), and was followed by reduction using tin(II)chloride and sodium iodide as reducing agents to give the amino-poly(ether sulfone). The S-APES was obtained by reaction of 1,3-propanesultone and the amino-poly(ether sulfone) (NH{sub 2}-PES) with sodium methoxide. The different degrees of nitration and reduction of poly(ether sulfone) were successfully synthesized by an optimized process. The reduction of nitro group to amino was done quantitatively, and this controlled the contents of the sulfonic acid group. The films were converted from salt to acid forms with dilute hydrochloric acid. Different contents of sulfonated unit of the S-APES were studied by FT-IR, {sup 1}H NMR spectroscopy, differential scanning calorimetry (DSC), and thermo gravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymers with water and methanol. The ion exchange capacity (IEC), a measure of proton conductivity, was evaluated. The S-APES membranes exhibit conductivities (25 C) from 1.05 x 10{sup -3} to 4.83 x 10{sup -3} S/cm, water swell from 30.25 to 66.50%, IEC from 0.38 to 0.82 meq/g, and methanol diffusion coefficients from 3.10 x 10{sup -7} to 4.82 x 10{sup -7} cm{sup 2}/S at 25 C. (author)

  14. Synthesis of a novel thermo/pH sensitive nanogel based on salep modified graphene oxide for drug release

    International Nuclear Information System (INIS)

    Bardajee, Ghasem Rezanejade; Hooshyar, Zari; Farsi, Maryam; Mobini, Akram; Sang, Golnaz

    2017-01-01

    Nanogels (NGs) are three-dimensional water soluble cross-linked hydrogel materials in the nanoscale size range with a high loading capacity for guest molecules and act as drug carrier systems. In the present work, a new type of thermo/pH sensitive NG comprising salep modified graphene oxide (SMGO) with branched N-isopropylacrylamide (NIPAM) and acrylic acid (AA) was prepared. The SMGO/P(NIPAM-co-AA) NGs exhibited nanoporous structure and spherical particles with diameters about 82 nm as characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), and dynamic light scattering (DLS). The samples were also characterized by Fourier transform infrared spectroscopy (FT-IR) and thermo gravimetric analysis (TGA) to further confirm about the formation of NGs. Doxorubicin (DOX) loaded SMGO/P(NIPAM-co-AA) NGs showed thermo/pH dependent releasing behavior: slow drug release at neutral pH and lower temperature but increased significantly in acidic pH and higher temperature, without any burst release. In addition, the NGs exhibited no effect on the cell viability in the tested concentration range up to 410 μg/mL and drug release systems enhanced toxicity to HeLa cells when compared to the equivalent dose of the free drug. Overall, our results put forth NGs as potential candidates in the development of a new nanocarrier for anti-cancer drug delivery. - Highlights: • A novel thermo/pH sensitive nanogels (NGs) was successfully synthesized. • NGs showed high loading capacity for DOX drug and slow drug release at neutral pH. • NGs exhibited no effect on the cell viability in the tested concentration range.

  15. Synthesis and Characterization of Poly(hydroxyethyl methacrylate-co-methacrylic acid) Cross Linked Polymeric Network for the Delivery of Analgesic Agent

    International Nuclear Information System (INIS)

    Rashid, H.; Ahmad, M.; Minhas, M. U.; Aamir, M. F.; Sohail, M.

    2015-01-01

    Objective of the study was to synthesize a chemically cross-linked poly(hydroxyethylmethacrylate-co-methacrylic acid) hydrogel (p(HEMA-co-MAA hydrogel)) for pH-responsive, controlled drug delivery of Flurbiprofen. pH-sensitive hydrogel drug delivery system was synthesized with the help of poly hydroxyethyl methacrylate (HEMA) and methacrylic acid (MAA) by using ethylene glycol dimethacrylate (EGDMA) as crosslinker. The monomers (HEMA and MAA) were successfully cross linked through free radical polymerization process, initiated by benzoyl peroxide in an aqueous medium. All formulations were loaded with Flurbiprofen as a model drug and evaluated at pH 1.2 and pH 7.4 to investigate pH-responsive nature of the system. Fourier transform infrared spectroscopy (FTIR) was performed to confirm the cross-linking of copolymer while thermo gravimetric analysis (TGA) and differential scanning calorimetry (DSC) were performed to evaluate the thermal stability of the system. Swelling studies and in-vitro release studies were carried out to evaluate pH-responsive nature of the hydrogels. FTIR confirmed that monomers were successfully cross-linked to form a copolymer. Hydrogel system showed less swelling at lower pH while at higher pH, it showed higher swelling, releasing drug in the same fashion. It was concluded that a stable hydrogel network was chemically cross-linked showing pH-responsive nature and thus, synthesized p(HEMA-co-MAA) hydrogels can be successfully employed as potential candidate for controlled drug delivery. (author)

  16. Removal of chromium (VI) ions from aqueous solutions using amine-impregnated TiO2 nanoparticles modified cellulose acetate membranes.

    Science.gov (United States)

    Gebru, Kibrom Alebel; Das, Chandan

    2018-01-01

    In this work, TiO 2 nanoparticles (NPs) were modified using tetraethylenepentamine (TEPA), ethylenediamine (EDA), and hexamethylenetetramine (HMTA) amines using impregnation process. The prepared amine modified TiO 2 samples were explored as an additive to fabricate ultrafiltration membranes with enhanced capacity towards the removal of chromium ions from aqueous solution. Modified membranes were prepared from cellulose acetate (CA) polymer blended with polyethylene glycol (PEG) additive, and amine modified TiO 2 by using phase inversion technique. Fourier transform infrared spectroscopy (FTIR), zeta potential (ζ), thermo gravimetric analysis (TGA), field emission scanning electron microscopy (FESEM), water contact angle (WCA), and atomic absorption spectrophotometer (AAS) studies were done to characterize the membranes in terms of chemical structure, electric charge, thermal stability, morphology, hydrophilicity, and removal performance. The pure water permeability and Cr (VI) ion removal efficiency of the unmodified (i.e. CA/U-Ti) and the amine modified (CA/Ti-HMTA, CA/Ti-EDA, and CA/Ti-TEPA) membranes were dependent on pH and metal ion concentration. Incorporation of amine modified TiO 2 composite to the CA polymer was found to improve the fouling and removal characteristics of the membranes during the chromium ultrafiltration process. The maximum removal efficiency result of Cr (VI) ions at pH of 3.5 using CA/Ti-TEPA membrane was 99.8%. The washing/regeneration cycle results in this study described as an essential part for prospect industrial applications of the prepared membranes. The maximum Cr (VI) removal results by using CA/Ti-TEPA membrane for four washing/regeneration cycles are 99.6%, 99.5%, 98.6% and, 96.6%, respectively. Copyright © 2017 Elsevier Ltd. All rights reserved.

  17. Mechanism of the hydrogen reduction of molybdenum oxides

    International Nuclear Information System (INIS)

    Schulmeyer, W.V.; Ortner, H.M.

    2001-01-01

    The two stages of the hydrogen reduction of MoO 3 to Mo were investigated in a thermal balance under well defined reaction conditions. Starting with different grain and agglomerate sizes for both stages, the influence of a set of parameters (temperature, local partial pressure of H 2 O, gas flow, etc.) on the reaction progress and the final result were studied in detail. Depending on the set of parameters used, different reaction mechanisms like pseudomorphic transformation or chemical vapor transport (CVT) were observed. Taking into account that grains and agglomerates deviate from a spherical shape and a definite grain size, the extent of reaction is well described by standard theoretical gas-solid-reaction models such as the shrinking core model (SCM) or the crackling core model (CCM). Thermo-gravimetric analysis (TGA), x-ray diffraction (XRD), scanning electron microscopy (SEM), surface area measurements (BET-method) and laser diffraction were used for these studies. Under all conditions, the first stage shows a reaction path MoO 3 → Mo 4 O 11 → MoO 2 via chemical vapor transport (CVT). The reaction extent follows the crackling core model (Park/Levenspiel). Depending on the local partial pressure of H 2 O during reduction, the formed Mo 4 O 11 and MoO 2 exhibit different size distributions and shapes of the grains. The extent of reaction of the second stage develops according to the shrinking core model (Yagi/Kunii). Depending on the local dew point, two different reaction paths can occur: pseudomorphic transformation at low dew points and transformation via chemical vapor transport at high dew points. This paper is an extract from the Ph.D. thesis of W.V. Schulmeyer 'Mechanismen der Wasserstoffreduktion von Molybdaenoxiden', 1998, Darmstadt University of Technology, Institute of Material Science, Department of Chemical Analytics, FRG. It therefor focuses on a phenomenological description of the most important results. (author)

  18. High temperature oxidation behaviour of nanostructured cermet coatings in amixed CO/sub 2/ - O/sub 2/ environment

    International Nuclear Information System (INIS)

    Farrokhzad, M. A.; Khan, T. I.

    2013-01-01

    Nanostructured ceramic-metallic (cermet) coatings composed of nanosized ceramic particles (alpha-Al /sub 2/O/sub 3/ and TiO/sub 2/) dispersed in a nickel matrix were co-electrodeposited and then oxidized at 500 degree C, 600 degree C and 700 degree C in a mixed gas using a Thermo-gravimetric Analysis (TGA) apparatus. The mixed gas was composed of 15 percentage CO/sub 2/, 10 percentage O/sub 2/ and 75 percentage N/sub 2/. This research investigates the effects of CO/sub 2/ and O/sub 2/ partial pressures on time-depended oxidation rates for coatings and compared them to the results from atmospheric oxidation under similar temperatures. The increase in partial pressure of oxygen due to the presence of CO/sub 2/ at each tested temperature was calculated and correlated to the oxidation rate of the coatings. The results showed that the presence of CO/sub 2/ in the system increased the oxidation rate of cermet coatings when compared to atmospheric oxidation at the same temperature. It was also shown that the increase in the oxidation rate is not the result of CO/sub 2/ acting as the primary oxidant but as a secondary oxidant which results in an increase of the total partial pressure of oxygen and consequently higher oxidation rates. The WDS and XRD analyses results showed that the presence of nanosized TiO/sub 2/ particles in a nickel matrix can improve oxidation behaviour of the coatings by formation of Nu i-Tau i compounds on oxidizing surface of the coating which was found beneficiary in reducing the oxidation rates for cermet coatings. (author)

  19. The improvement of corrosion resistance of fluoropolymer coatings by SiO{sub 2}/poly(styrene-co-butyl acrylate) nanocomposite particles

    Energy Technology Data Exchange (ETDEWEB)

    Chen, L. [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Song, R.G., E-mail: songrg@hotmail.com [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Li, X.W.; Guo, Y.Q.; Wang, C.; Jiang, Y. [School of Materials Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Materials Surface Science and Technology, Changzhou University, Changzhou 213164 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China)

    2015-10-30

    Highlights: • We first proposed the feasibility of organic-inorganic hybrid particles can be used to reduce free space of the fluoropolymer coatings. • By grafting poly(styrene-co-butyl acrylate), nano-silica particles can be better dispersed in the fluoropolymer coatings system. • The coating-substrates bound strength could be obviously seen in the FESEM cross-section images. • The effects of the corrosion resistance of fluoropolymer-coated steel were investigated by potentiodynamic polarization and EIS. • Using models to analysis the anticorrosion mechanism of nanocomposite coatings. - Abstract: The effects of nano-silica particles on the anticorrosion properties of fluoropolymer coatings on mild steel have been investigated in this paper. In order to enhance the dispersibility of nano-silica in fluoropolymer coatings, we treated the surface of nano-silica with poly(styrene-co-butyl acrylate) (P(St-BA)). The surface grafting of P(St-BA) on the nanoparticles were detected using Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analyzer (TGA), field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM). The surface of nanocomposite coatings and the coating-substrates bond texture were detected by FE-SEM. We also used energy-dispersive X-ray spectroscopy (EDS) to analyze whether the nanocomposite particles were added into the fluoropolymer coatings. In addition, the influences of various nanoparticles on the corrosion resistance of fluoropolymer-coated steel were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results shown that nanocomposite particles can be dispersed better in fluoropolymer coatings, and the electrochemical results clearly shown the improvement of the protective properties of the nanocomposite coatings when 4 wt.% SiO{sub 2}/P(St-BA) was added to the fluoropolymer coatings.

  20. Post synthetic modification of MIL-101(Cr) for S-shaped isotherms and fast kinetics with water adsorption

    International Nuclear Information System (INIS)

    Teo, How Wei Benjamin; Chakraborty, Anutosh; Kayal, Sibnath

    2017-01-01

    Highlights: • Modification of parent MIL-101(Cr) metal organic framework (MOF) employing alkali metal ions (Li + , Na + , K + ). • Surface characteristics of the parent and alkali doped MIL-101(Cr) adsorbents. • Water uptakes are measured for the temperatures ranging from 25 °C to 60 °C under static and dynamic conditions. • Isotherms and kinetics data are fitted with Langmuir analogy models. • The 5% Li-doped MIL-101(Cr) is suitable for adsorption cooling. - Abstract: This article presents the surface characteristics of alkali (Li + , Na + , K + ) doped MIL-101(Cr) metal organic frameworks (MOFs), and the structural properties are evaluated by scanning electron micrography (SEM), X-ray diffraction (XRD), thermo-gravimetric analyser (TGA) and N 2 adsorption analysis. The amount of water uptakes are measured by a gravimetric analyser for the temperatures ranging from 298 K to 333 K and pressures up to the saturated conditions. The experimentally measured isotherms and kinetics data are fitted with the equations developed from the concept of Langmuir analogy. The isosteric heat of adsorption is calculated employing Van’t Hoff equation in the pressure-temperature-uptake co-ordinate systems. The hydrophobic length at low pressure regions is shortened by the addition of alkali dopants. It is observed that the alkali (Na, K and Li) ions on MIL-101(Cr) MOF increase the water uptakes at lower relative pressure region with fast kinetics. We have shown here that the alkali doped MIL-101(Cr) MOFs can be used as potential adsorbents for various low temperature heat transmission applications such as adsorption assisted heat pump, cooling and desalination.

  1. Biomimetic nanocomposites of carboxymethyl cellulose-hydroxyapatite: novel three dimensional load bearing bone grafts.

    Science.gov (United States)

    Garai, Subhadra; Sinha, Arvind

    2014-03-01

    An innovative biomimetic synthesis of novel three dimensional micro/macro porous carboxymethyl cellulose (CMC)-hydroxyapatite (HA) nanocomposites having four systematically different compositions has been established for its possible application as a load bearing synthetic bone graft. Our process, being in situ, involves a simple and cost effective route akin to a matrix mediated biomineralization process. Developed synthesis route not only controls the size of HA particles in the range of 15-50 nm, embedded in CMC matrix, but also assists in the formation of a mechanically strong three dimensional nanocomposite structures due to physical cross linking of HA impregnated CMC matrix. The process does not involve any toxic cross linker and works at near ambient conditions. The nanocomposites are systematically structurally and mechanically characterized using various techniques like scanning electron microscopy (SEM), atomic force microscopy (AFM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform IR (FTIR), solid state (13)C nuclear magnetic resonance ((13)C NMR), thermo-gravimetric analysis (TGA) and Universal mechanical test. It reveals that the ionic/polar or electrostatic interactions are the main driving force for formation of load bearing three dimensional nanocomposites via a process similar to matrix mediated biomineralization. Compressive strength and compressive modulus of nanocomposites, being in the range of 1.74-12 MPa and 157-330 MPa, respectively, meet the desired range of compressive strength for the synthetic grafts used in cancellous bone. An increase in the compressive strength with increase in the porosity has been an interesting observation in the present study. In vitro cytotoxicity of the synthesized nanocomposites has been evaluated using bone marrow mesenchymal stem cells (BMSC) isolated from Wistar rat. Copyright © 2013 Elsevier B.V. All rights reserved.

  2. Assessment of cement durability in repository environment

    International Nuclear Information System (INIS)

    Ferreira, E.G.A.; Vicente, R.; Isiko, V.L.K.; Miyamoto, H.; Marumo, J.T.; Gobbo, L.A.

    2015-01-01

    The present research aimed at investigating the durability of cement paste under nuclear waste repository conditions using accelerated tests. Cement paste samples are examined after being exposed to the environmental conditions that are expected to prevail in the repository environment and the results are compared with those obtained with unexposed specimens or specimens exposed to reference conditions. The following exposure conditions were selected: a) Immersion in salt solution, distilled water, or kept in dry storage; b) Room temperature (20 C. degrees) or high temperature (60 C. degrees); c) Immersion time of 30 days or 60 days (not for dry storage); d) Irradiation to a dose of (400 kGy) or background radiation (0 kGy). After exposure to the stressing conditions, the effects of each factor on the cement paste samples were observed by changes in their characteristics. Compressive strength tests were performed on all samples and some of them were investigated in terms of changes in mineralogy by X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). With the results obtained so far it was possible to point out the following conclusions. First, after a period of immersion in water, cement paste samples further hydrated and presented higher mechanical resistance, as expected. Secondly, dry storage did not allow a complete hydration as a consequence of pore water evaporation. High temperatures intensified this process and led to the ettringite decomposition to meta-ettringite. Thirdly, higher temperature accelerated hydration kinetics and promoted higher mechanical resistance in samples kept under immersion. Fourthly, the irradiation dose applied was unable to change the mineralogy of cement paste samples and fifthly, no statistically significant differences were observed between 30 or 60 days exposure time, for the test conditions

  3. Temperature-modified photonic bandgap in colloidal photonic crystals fabricated by vinyl functionalized silica spheres

    International Nuclear Information System (INIS)

    Deng Tiansong; Zhang Junyan; Zhu Kongtao; Zhang Qifeng; Wu Jinlei

    2011-01-01

    Graphical abstract: A thermal annealing procedure was described for fine modifying the photonic bandgap properties of colloidal photonic crystals, which were self-assembled from vinyl-functionalized silica spheres by a gravity sedimentation process. Highlights: → We described a thermal annealing procedure for fine modifying the photonic bandgap properties of colloidal photonic crystals. → The position of its stop band had more than 25% blue shift by annealing the sample from 60 to 600 deg. C. → The annealing temperature and the Bragg peak values have a linear relationship in the 120-440 deg. C range. → The effects provide a simple and controllable method for modifying the photonic bandgap properties of colloidal photonic crystals. - Abstract: A thermal annealing procedure for fine modifying the photonic bandgap properties of colloidal photonic crystals was described. The colloidal photonic crystals were assembled from monodisperse vinyl functionalized silica spheres by a gravity sedimentation process. The samples diffract light following Bragg's law combined with Snell's law. By annealing the sample at temperatures in the range of 60-600 deg. C, the position of its stop band shifted from 943 to 706 nm. It had more than 25% blue shift. In addition, the annealing temperature and the Bragg peak values have a linear relationship in the 120-440 deg. C range. Fourier transform infrared (FT-IR) spectra and thermo-gravimetric analysis (TGA) curves of vinyl functionalized silica spheres confirmed the above results. The effects provide a simple and controllable method for modifying the photonic bandgap properties of colloidal photonic crystals.

  4. Ammonia detection of 1-D ZnO/polypyrrole nanocomposite: Effect of CSA doping and their structural, chemical, thermal and gas sensing behavior

    Energy Technology Data Exchange (ETDEWEB)

    Jain, Shilpa [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Karmakar, Narayan [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Shah, Akshara [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Kothari, D.C. [Department of Physics, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); National Centre for Nanosciences& Nanotechnology, University of Mumbai, Santacruz (East), Mumbai-400098,India (India); Mishra, Satyendra [University Institute of Chemical Technology, North Maharashtra University, Jalgaon (India); Shimpi, Navinchandra G, E-mail: navin_shimpi@rediffmail.com [Department of Chemistry, University of Mumbai, Santacruz (East), Mumbai-400098,India (India)

    2017-02-28

    Highlights: • Synthesis of 1-Dimensional ZnO-Polypyrrole nanocomposite using In-situ oxidative polymerization technique. • High response ammonia sensing. • Optimization of ZnO content in nanocomposites for maximum sensor response. • Effect of CSA doping on structural, thermal, optical and sensing behavior. • Optimization of CSA concentration for high sensitivity, fast response and recovery time. - Abstract: Nanocomposites of polypyrrole (PPy) with varying concentration of ZnO nanorods (ZnO NRs) were synthesized using in-situ oxidative polymerization technique. The prepared nanocomposites (PPy, PPy-ZnO and CSA doped PPy-ZnO) were studied for various oxidizing and reducing gases at room temperature and found to be more selective towards ammonia gas. Various concentrations of ZnO NRs in Ppy matrix were studied and 15% was found to be optimum in terms of sensor response (66% towards 120 ppm NH{sub 3}). Further, with 15% doping of camphor sulphonic acid (CSA) in PPy-ZnO nanocomposite for 15% ZnO NRs in Ppy matrix, sensor response increased from 66 to 79% towards 120 ppm of NH{sub 3}. Structural, Optical and thermal behavior of nanocomposites were studied using powder X-ray diffraction (XRD), Fourier Transform Infra-Red (FTIR) spectroscopy, X-ray Photoelectron Spectroscopy (XPS), UV–vis (UV–vis) absorption spectroscopy, room temperature Photoluminescence (PL) Spectroscopy, Thermo-gravimetric analysis (TGA) and Field Emission Scanning Electron Microscopy (FESEM). ZnO has been completely embedded inside the polymeric chains as observed from in SEM. Meanwhile, FT-IR spectra indicate better conjugation and interaction in nanocomposites. With CSA doping interaction grows stronger due to extended delocalization over π electrons leading to higher sensor response and with response time and recovery time of 24 s and 34 s respectively. CSA doped PPy-ZnO (15%) nanocomposites observed to be a potential candidate for ammonia detection at lower ppm level.

  5. Influence of alkaline treatment and fiber loading on the physical and mechanical properties of kenaf/polypropylene composites for variety of applications☆

    Institute of Scientific and Technical Information of China (English)

    Majid Niaz Akhtar; Abu Bakar Sulong; M.K. Fadzly Radzi; N.F. Ismail; M.R. Raza; Norhamidi Muhamad; Muhammad Azhar Khan

    2017-01-01

    Due to current trend and increasing interest towards natural based fiber products, Kenaf (Hibiscus cannabinus) fibers have been used for the developments of many products. Therefore, Kenaf fiber-reinforced composites have been widely used in engineering and industrial applications. The present work deals with the fabricating and characterization of untreated and treated kenaf/polypropylene (PP)-reinforced composites. Composites of PP reinforced with treated and untreated kenaf fibers were fabricated using the injection molding technique. Different fiber loadings of 10, 20, 30, 40, 50 wt%treated and untreated kenaf composites were also prepared. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis (TGA) were performed on the treated, untreated kenaf fibers and kenaf/PP composites. Moreover, the alkaline-treated kenaf composites exhibit better physical, morphological, and mechanical properties because of the compatibility of kenaf with PP. However, variations in tensile and flexural properties depend on treatment and kenaf fiber contents. The percentage increase in the mechanical properties of the treated kenaf/PP composites relative to that of PP was also measured. In addition, 40 wt%kenaf fiber loading resulted in higher mechanical properties. By contrast, kenaf/PP composite with 50%fiber loading was not successfully prepared because of improper mixing and the burning of kenaf fibers in the PP matrix. To conclude, 40%kenaf/PP composites with superior physical and mechanical properties may be used in variety of applications such as automotive, sports, construction, animal bedding, and mass production industries.

  6. Influence of alkaline treatment and fiber loading on the physical and mechanical properties of kenaf/polypropylene composites for variety of applications

    Institute of Scientific and Technical Information of China (English)

    Majid Niaz Akhtar; Abu Bakar Sulong; M.K.Fadzly Radzi; N.F.Ismail; M.R.Raza; Norhamidi Muhamad; Muhammad Azhar Khan

    2016-01-01

    Due to current trend and increasing interest towards natural based fiber products,Kenaf (Hibiscus cannabinus) fibers have been used for the developments of many products.Therefore,Kenaf fiber-reinforced composites have been widely used in engineering and industrial applications.The present work deals with the fabricating and characterization of untreated and treated kenaf/polypropylene (PP)-reinforced composites.Composites of PP reinforced with treated and untreated kenaf fibers were fabricated using the injection molding technique.Different fiber loadings of 10,20,30,40,50 wt% treated and untreated kenaf composites were also prepared.Xray diffraction (XRD),scanning electron microscopy (SEM),Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis (TGA) were performed on the treated,untreated kenaf fibers and kenaf/PP composites.Moreover,the alkaline-treated kenaf composites exhibit better physical,morphological,and mechanical properties because of the compatibility of kenaf with PP.However,variations in tensile and flexural properties depend on treatment and kenaf fiber contents.The percentage increase in the mechanical properties of the treated kenaf/PP composites relative to that of PP was also measured.In addition,40 wt%kenaf fiber loading resulted in higher mechanical properties.By contrast,kenaf/PP composite with 50% fiber loading was not successfully prepared because of improper mixing and the burning of kenaf fibers in the PP matrix.To conclude,40% kenaf/PP composites with superior physical and mechanical properties may be used in variety of applications such as automotive,sports,construction,animal bedding,and mass production industries.

  7. High temperature oxidation behaviour of nanostructured cermet coatings in a mixed CO2 - O2 environment

    Science.gov (United States)

    Farrokhzad, M. A.; Khan, T. I.

    2014-06-01

    Nanostructured ceramic-metallic (cermet) coatings composed of nanosized ceramic particles (α-Al2O3 and TiO2) dispersed in a nickel matrix were co-electrodeposited and then oxidized at 500°C, 600°C and 700°C in a mixed gas using a Thermo-gravimetric Analysis (TGA) apparatus. The mixed gas was composed of 15% CO2, 10% O2 and 75% N2. This research investigates the effects of CO2 and O2 partial pressures on time-depended oxidation rates for coatings and compared them to the results from atmospheric oxidation under similar temperatures. The increase in partial pressure of oxygen due to the presence of CO2 at each tested temperature was calculated and correlated to the oxidation rate of the coatings. The results showed that the presence of CO2 in the system increased the oxidation rate of cermet coatings when compared to atmospheric oxidation at the same temperature. It was also shown that the increase in the oxidation rate is not the result of CO2 acting as the primary oxidant but as a secondary oxidant which results in an increase of the total partial pressure of oxygen and consequently higher oxidation rates. The WDS and XRD analyses results showed that the presence of nanosized TiO2 particles in a nickel matrix can improve oxidation behaviour of the coatings by formation of Ni-Ti compounds on oxidizing surface of the coating which was found beneficiary in reducing the oxidation rates for cermet coatings.

  8. Comparative Investigation of 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 Cathode Materials Synthesized by Using Different Lithium Sources

    Directory of Open Access Journals (Sweden)

    Peng-Bo Wang

    2018-05-01

    Full Text Available Lithium-rich manganese-based cathode materials has been attracted enormous interests as one of the most promising candidates of cathode materials for next-generation lithium ion batteries because of its high theoretic capacity and low cost. In this study, 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 materials are synthesized through a solid-state reaction by using different lithium sources, and the synthesis process and the reaction mechanism are investigated in detail. The morphology, structure, and electrochemical performances of the material synthesized by using LiOH·H2O, Li2CO3, and CH3COOLi·2H2O have been analyzed by using Thermo gravimetric analysis (TGA, X-ray diffraction (XRD, Scanning electron microscope (SEM, Transmission electron microscope (TEM, X-ray photoelectron spectroscopy (XPS, and electrochemical measurements. The 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 material prepared by using LiOH·H2O displays uniform morphology with nano particle and stable layer structure so that it suppresses the first cycle irreversible reaction and structure transfer, and it delivers the best electrochemical performance. The results indicate that LiOH·H2O is the best choice for the synthesis of the 0.5Li2MnO3·0.5LiNi0.5Co0.2Mn0.3O2 material.

  9. Keratin based bioplastic film from chicken feathers and its characterization.

    Science.gov (United States)

    Ramakrishnan, Navina; Sharma, Swati; Gupta, Arun; Alashwal, Basma Yahya

    2018-05-01

    Plastics have been one of the highly valued materials and it plays an significant role in human's life such as in food packaging and biomedical applications. Bioplastic materials can gradually work as a substitute for various materials based on fossil oil. The issue like sustainability and environmental challenges which occur due to manufacturing and disposal of synthetic plastics can be conquering by bio-based plastics. Feathers are among the most inexpensive abundant, and renewable protein sources. Feathers disposal to the landfills leads to environmental pollutions and it results into wastage of 90% of protein raw material. Keratin is non-burning hydrophilic, and biodegradable due to which it can be applicable in various ways via chemical processing. Main objective of this research is to synthesis bioplastic using keratin from chicken feathers. Extracted keratin solution mixed with different concentration of glycerol (2 to 10%) to produce plastic films. The mixture was stirred under constant magnetic stirring at 60 °C for 5 h. The mixtures are then poured into aluminum weighing boat and dried in an oven at 60 °C for 24 h. The mechanical properties of the samples were tested and the physic-chemical properties of the bioplastic were studied. According to the results, Scanning Electron Microscopy test showed good compatible morphologies without holes, cavity and edge. The difference in chemical composition was analyzed using Fourier transform infrared spectroscopy (FTIR). The samples were also characterized by thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), X-Ray diffraction (XRD) to check the thermal and crystallinity properties. Other than that, bioplastic made up from keratin with 2% of glycerol has the best mechanical and thermal properties. According to biodegradability test, all bioplastic produced are proven biodegradable. Therefore, the results showed possible application of the film as an alternative to fossil oil

  10. Influence of alkaline treatment and fiber loading on the physical and mechanical properties of kenaf/polypropylene composites for variety of applications

    Directory of Open Access Journals (Sweden)

    Majid Niaz Akhtar

    2016-12-01

    Full Text Available Due to current trend and increasing interest towards natural based fiber products, Kenaf (Hibiscus cannabinus fibers have been used for the developments of many products. Therefore, Kenaf fiber-reinforced composites have been widely used in engineering and industrial applications. The present work deals with the fabricating and characterization of untreated and treated kenaf/polypropylene (PP-reinforced composites. Composites of PP reinforced with treated and untreated kenaf fibers were fabricated using the injection molding technique. Different fiber loadings of 10, 20, 30, 40, 50 wt% treated and untreated kenaf composites were also prepared. X-ray diffraction (XRD, scanning electron microscopy (SEM, Fourier transform infrared (FTIR spectroscopy and thermo gravimetric analysis (TGA were performed on the treated, untreated kenaf fibers and kenaf/PP composites. Moreover, the alkaline-treated kenaf composites exhibit better physical, morphological, and mechanical properties because of the compatibility of kenaf with PP. However, variations in tensile and flexural properties depend on treatment and kenaf fiber contents. The percentage increase in the mechanical properties of the treated kenaf/PP composites relative to that of PP was also measured. In addition, 40 wt% kenaf fiber loading resulted in higher mechanical properties. By contrast, kenaf/PP composite with 50% fiber loading was not successfully prepared because of improper mixing and the burning of kenaf fibers in the PP matrix. To conclude, 40% kenaf/PP composites with superior physical and mechanical properties may be used in variety of applications such as automotive, sports, construction, animal bedding, and mass production industries.

  11. Tailoring mechanical and antibacterial properties of chitosan/gelatin nanofiber membranes with Fe3O4 nanoparticles for potential wound dressing application

    Science.gov (United States)

    Cai, Ning; Li, Chao; Han, Chao; Luo, Xiaogang; Shen, Liang; Xue, Yanan; Yu, Faquan

    2016-04-01

    In this work, magnetic Fe3O4 nanoparticles (NPs) were utilized to improve the mechanical and antibacterial properties of chitosan (CS)/gelatin (GE) composite nanofiber membranes. Homogeneous Fe3O4/CS/GE nanofibers were electrospun successfully. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images confirmed the presence of well-dispersed Fe3O4 NPs in the composite nanofibers. Fourier transform infrared spectroscopy (FTIR) spectra revealed the effective interactions of Fe3O4 NPs to the composite matrix through hydrogen bonding. The improvement on the thermal stability of the Fe3O4/CS/GE was observed by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), which is tightly correlated to strong filler-matrix adhesion. The incorporation of Fe3O4 NPs resulted in a substantial enhancement of mechanical properties. The optimum mechanical performance was demonstrated on 1 wt% Fe3O4/CS/GE nanofiber membranes, achieving 155% augment of Young's modulus, 128% increase of tensile strength, and 100% boost of toughness from CS/GE. The excellent mechanical enhancement can be explained by the effective dispersion of fillers and the filler-matrix interactions, which ensures the efficient load transfer from CS/GE matrix to Fe3O4 nanofillers. Moreover, zones of inhibition for Escherichia coli and Staphylococcus aureus expanded markedly with the supplement of Fe3O4 NPs. In all, nanofiber membranes made of Fe3O4/CS/GE composite with tailored mechanical and antibacterial properties appear a promising wound dressing material.

  12. Non-equilibrium synthesis of alloys using lasers

    International Nuclear Information System (INIS)

    Mazumder, J.; Choi, J.; Ribaudo, C.; Wang, A.; Kar, A.

    1993-01-01

    This paper discusses microstructure and properties of alloys, produced by laser alloying and cladding technique, for various applications. These include Fe-Cr-W-C alloys for wear resistance, Ni-Cr-Al-Hf alloys for high temperature oxidation resistance and Mg-Al alloys for corrosion resistance. Also a mathematical model will be presented for the prediction of the composition of the metastable phases produced by laser synthesis. Microstructure was characterized using various electron optical techniques such as Transmission Electron Microscopy (TEM), Scanning Electron Microscopy (SEM), Auger Electron Spectroscopy (AES) and Energy Dispersive X-Ray Analysis (EDAX). Wear properties were characterized by a line contact Block on Cylinder method. High temperature oxidation properties were characterized by using Perkin-Elmer Thermo-Gravimetric Analyzer (TGA) where dynamic weight change were monitored at 1,200 C. Corrosion properties were evaluated by a potentio-dynamic method using a computer controlled Potentiostat manufactured by EG ampersand G. A non-equilibrium M 6 C type carbide was found to be responsible for the improved wear resistance. Increased solid-solubility of Hf was found to be a major factor in improving the high temperature oxidation resistance of the Ni-Cr-Al-Hf alloys. Micro-Crystalline phases were observed in Mg-Al alloys. The rapid solidification was modeled using heat transfer in the liquid pool and the solid substrate and mass transfer in the liquid pool. Non-equilibrium partition coefficient was introduced through the boundary condition at the liquid-solid interface. A good correlation was observed between the prediction and the experimental data. 54 refs

  13. Characterization of uranium corrosion products involved in the March 13, 1998 fuel manufacturing facility pyrophoric event.

    Energy Technology Data Exchange (ETDEWEB)

    Totemeier, T.C.

    1999-04-26

    Uranium metal corrosion products from ZPPR fuel plates involved in the March 13, 1998 pyrophoric event in the Fuel Manufacturing Facility at Argonne National Laboratory-West were characterized using thermo-gravimetric analysis, X-ray diffraction, and BET gas sorption techniques. Characterization was performed on corrosion products in several different conditions: immediately after separation from the source metal, after low-temperature passivation, after passivation and extended vault storage, and after burning in the pyrophoric event. The ignition temperatures and hydride fractions of the corrosion product were strongly dependent on corrosion extent. Corrosion products from plates with corrosion extents less than 0.7% did not ignite in TGA testing, while products from plates with corrosion extents greater than 1.2% consistently ignited. Corrosion extent is defined as mass of corrosion products divided by the total mass of uranium. The hydride fraction increased with corrosion extent. There was little change in corrosion product properties after low-temperature passivation or vault storage. The burned products were not reactive and contained no hydride; the principal constituents were UO{sub 2} and U{sub 3}O{sub 7}. The source of the event was a considerable quantity of reactive hydride present in the corrosion products. No specific ignition mechanism could be conclusively identified. The most likely initiator was a static discharge in the corrosion product from the 14th can as it was poured into the consolidation can. The available evidence does not support scenarios in which the powder in the consolidation can slowly self-heated to the ignition point, or in which the powder in the 14th can was improperly passivated.

  14. A novel highly selective and sensitive detection of serotonin based on Ag/polypyrrole/Cu2O nanocomposite modified glassy carbon electrode.

    Science.gov (United States)

    Selvarajan, S; Suganthi, A; Rajarajan, M

    2018-06-01

    A silver/polypyrrole/copper oxide (Ag/PPy/Cu 2 O) ternary nanocomposite was prepared by sonochemical and oxidative polymerization simple way, in which Cu 2 O was decorated with Ag nanoparticles, and covered by polyprrole (PPy) layer. The as prepared materials was characterized by UV-vis-spectroscopy (UV-vis), FT-IR, X-ray diffraction (XRD), thermo-gravimetric analysis (TGA), scanning electron microscopy (SEM) with EDX, high resolution transmission electron microscopy (HR-TEM) and X-ray photoelectron spectroscopy (XPS). Sensing of serotonin (5HT) was evaluated electrocatalyst using polypyrrole/glassy carbon electrode (PPy/GCE), polypyrrole/copper oxide/glassy carbon electrode (PPy/Cu 2 O/GCE) and silver/polypyrrole/copper oxide/glassy carbon electrode (Ag/PPy/Cu 2 O/GCE). The Ag/PPy/Cu 2 O/GCE was electrochemically treated in 0.1MPBS solution through cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The peak current response increases linearly with 5-HT concentration from 0.01 to 250 µmol L -1 and the detection limit was found to be 0.0124 μmol L -1 . It exhibits high electrocatalytic activity, satisfactory repeatability, stability, fast response and good selectivity against potentially interfering species, which suggests its potential in the development of sensitive, selective, easy-operation and low-cost serotonin sensor for practical routine analyses. The proposed method is potential to expand the possible applied range of the nanocomposite material for detection of various concerned electro active substances. Copyright © 2018 Elsevier B.V. All rights reserved.

  15. Thermogravimetric analysis of fuel film evaporation

    Institute of Scientific and Technical Information of China (English)

    HU Zongjie; LI Liguang; YU Shui

    2006-01-01

    Thermogravimetric analysis (TGA) was compared with the petrochemical distillation measurement method to better understand the characteristics of fuel film evaporation at different wall tem- peratures. The film evaporation characteristics of 90# gasoline, 93# gasoline and 0# diesel with different initial thicknesses were investigated at different environmental fluxes and heating rates. The influences of heating rate, film thickness and environmental flux on fuel film evaporation for these fuels were found. The results showed that the environmental conditions in TGA were similar to those for fuel films in the internal combustion engines, so data from TGA were suitable for the analysis of fuel film evaporation. TGA could simulate the key influencing factors for fuel film evaporation and could investigate the basic quantificational effect of heating rate and film thickness. To get a rapid and sufficient fuel film evaporation, sufficiently high wall temperature is necessary. Evaporation time decreases at a high heating rate and thin film thickness, and intense gas flow is important to promoting fuel film evaporation. Data from TGA at a heating rate of 100℃/min are fit to analyze the diesel film evaporation during cold-start and warming-up. Due to the tense molecular interactions, the evaporation sequence could not be strictly divided according to the boiling points of each component for multicomponent dissolved mixture during the quick evaporation process, and the heavier components could vaporize before reaching their boiling points. The 0# diesel film would fully evaporate when the wall temperature is beyond 250℃.

  16. Arabidopsis genes, AtNPR1, AtTGA2 and AtPR-5, confer partial resistance to soybean cyst nematode (Heterodera glycines) when overexpressed in transgenic soybean roots.

    Science.gov (United States)

    Matthews, Benjamin F; Beard, Hunter; Brewer, Eric; Kabir, Sara; MacDonald, Margaret H; Youssef, Reham M

    2014-04-16

    Extensive studies using the model system Arabidopsis thaliana to elucidate plant defense signaling and pathway networks indicate that salicylic acid (SA) is the key hormone triggering the plant defense response against biotrophic and hemi-biotrophic pathogens, while jasmonic acid (JA) and derivatives are critical to the defense response against necrotrophic pathogens. Several reports demonstrate that SA limits nematode reproduction. Here we translate knowledge gained from studies using Arabidopsis to soybean. The ability of thirty-one Arabidopsis genes encoding important components of SA and JA synthesis and signaling in conferring resistance to soybean cyst nematode (SCN: Heterodera glycines) are investigated. We demonstrate that overexpression of three of thirty-one Arabidoposis genes in transgenic soybean roots of composite plants decreased the number of cysts formed by SCN to less than 50% of those found on control roots, namely AtNPR1(33%), AtTGA2 (38%), and AtPR-5 (38%). Three additional Arabidopsis genes decreased the number of SCN cysts by 40% or more: AtACBP3 (53% of the control value), AtACD2 (55%), and AtCM-3 (57%). Other genes having less or no effect included AtEDS5 (77%), AtNDR1 (82%), AtEDS1 (107%), and AtPR-1 (80%), as compared to control. Overexpression of AtDND1 greatly increased susceptibility as indicated by a large increase in the number of SCN cysts (175% of control). Knowledge of the pathogen defense system gained from studies of the model system, Arabidopsis, can be directly translated to soybean through direct overexpression of Arabidopsis genes. When the genes, AtNPR1, AtGA2, and AtPR-5, encoding specific components involved in SA regulation, synthesis, and signaling, are overexpressed in soybean roots, resistance to SCN is enhanced. This demonstrates functional compatibility of some Arabidopsis genes with soybean and identifies genes that may be used to engineer resistance to nematodes.

  17. ESTIMACION DE LOS PARÁMETROS CINÉTICOS Y TIEMPO DE VIDA DE LA CÁSCARA DE ARROZ Y ARCILLA MEDIANTE LA TÉCNICA DE ANÁLISIS TERMOGRAVIMÉTRICO (TGA

    Directory of Open Access Journals (Sweden)

    POSIDIA PINEDA GOMEZ

    2011-01-01

    Full Text Available La cáscara de arroz y la arcilla son materiales comúnmente usados en procesos agrícolas e industriales, por lo cual es de interés científico el estudio de la cinética de sus descomposiciones térmicas en diferentes atmósferas. En este trabajo se estimaron los parámetros cinéticos (energía de activación, orden de reacción y factor preexponencial y el tiempo de vida que caracterizan el proceso de descomposición de la cáscara de arroz y la arcilla, mediante el uso de la técnica de análisis termogravimétrico (TGA. Se usaron en ambos casos atmósferas de nitrógeno y aire exponiendo las muestras a un programa de temperatura controlada en un rango de temperatura ambiente hasta 800 ºC, con velocidad de calentamiento de 10 ºC/min. Para la determinación de los parámetros cinéticos se utilizó un método basado en la linealización de la ecuación de Arrhenius, cuya solución se obtuvo por medio del software StatGraphics Plus 5.1. Los resultados obtenidos en el caso de la cáscara de arroz, presentan parámetros cinéticos y tiempos de vida inferiores a los mostrados por la arcilla, indicando para esta última altadurabilidad y resistencia a la degradación.

  18. SPM analysis and cognitive dysfunctions in patients with transient global amnesia

    International Nuclear Information System (INIS)

    Jeong, Young Jin; Kang, Do Young; Yun, Go Un; Park, Kyung Won; Kim, Jae Woo

    2004-01-01

    Transient global amnesia (TGA) is known as a disease of benign nature characterized with clinically transient global antegrade amnesia and a variable degree of global retrograde memory impairment, but it usually resolved within 24 hours. The aims of this study are to assess the alterations in regional cerebral blood flow (rCBF) by Tc-99m HMPAO SPECT imaging with statistical parametric mapping (SPM) analysis and to verify the cognitive deficits by neuropsychological test in TGA patients. Twelve patients with TGA and age-matched normal control subjects participated in this study. Tc-99m HMPAO SPECT was performed within 1 to 19 days (mean duration: 7.3:±5.2 days) after the events to measure the rCBF. SPECT images were analyzed using SPM (SPM99) with Matlab 5.3. Seoul Neuropsychological Screening Battery test was also done within 2 to 8 days (mean duration 3.8±2.2 days) for cognitive functions in 8 of 12 patients with TGA. The SPM analysis of SPECT images showed significantly decreased rCBF in the left inferior frontal gyrus (Brodmann area 9), the left supramarginal gyrus (Brodmann area 40), the left postcentral gyrus (Brodmann area 40) and the left precentral gyrus (Brodmann area 4) in patients with TGA (uncorrected p<0.01). Neuropsychological test findings represented that several cognitive functions. such as, verbal memory, visual memory, phonemic fluency and confrontational naming, were impaired in patients with TGA compared with normal control. Additionally, on SPM analysis, we found lesions of hyperperfusion in contralateral cerebral hemisphere. Our study shows perfusion deficits in the left cerebral hemisphere in patients with TGA and several cognitive dysfunctions. And we found after clinical symptoms were completely resolved, the lesions of hypoperfusion were still remained. We found that functional quantitative neuroimaging study and neuropsychological test are useful to understand underlying pathomachanism of TGA

  19. SPM analysis and cognitive dysfunctions in patients with transient global amnesia

    Energy Technology Data Exchange (ETDEWEB)

    Jeong, Young Jin; Kang, Do Young; Yun, Go Un; Park, Kyung Won; Kim, Jae Woo [School of Medicine, Donga University, Busan (Korea, Republic of)

    2004-07-01

    Transient global amnesia (TGA) is known as a disease of benign nature characterized with clinically transient global antegrade amnesia and a variable degree of global retrograde memory impairment, but it usually resolved within 24 hours. The aims of this study are to assess the alterations in regional cerebral blood flow (rCBF) by Tc-99m HMPAO SPECT imaging with statistical parametric mapping (SPM) analysis and to verify the cognitive deficits by neuropsychological test in TGA patients. Twelve patients with TGA and age-matched normal control subjects participated in this study. Tc-99m HMPAO SPECT was performed within 1 to 19 days (mean duration: 7.3:{+-}5.2 days) after the events to measure the rCBF. SPECT images were analyzed using SPM (SPM99) with Matlab 5.3. Seoul Neuropsychological Screening Battery test was also done within 2 to 8 days (mean duration 3.8{+-}2.2 days) for cognitive functions in 8 of 12 patients with TGA. The SPM analysis of SPECT images showed significantly decreased rCBF in the left inferior frontal gyrus (Brodmann area 9), the left supramarginal gyrus (Brodmann area 40), the left postcentral gyrus (Brodmann area 40) and the left precentral gyrus (Brodmann area 4) in patients with TGA (uncorrected p<0.01). Neuropsychological test findings represented that several cognitive functions. such as, verbal memory, visual memory, phonemic fluency and confrontational naming, were impaired in patients with TGA compared with normal control. Additionally, on SPM analysis, we found lesions of hyperperfusion in contralateral cerebral hemisphere. Our study shows perfusion deficits in the left cerebral hemisphere in patients with TGA and several cognitive dysfunctions. And we found after clinical symptoms were completely resolved, the lesions of hypoperfusion were still remained. We found that functional quantitative neuroimaging study and neuropsychological test are useful to understand underlying pathomachanism of TGA.

  20. Probing the interaction of a new synthesized CdTe quantum dots with human serum albumin and bovine serum albumin by spectroscopic methods

    Energy Technology Data Exchange (ETDEWEB)

    Bardajee, Ghasem Rezanejade, E-mail: rezanejad@pnu.ac.ir; Hooshyar, Zari

    2016-05-01

    A novel CdTe quantum dots (QDs) were prepared in aqueous phase via a facile method. At first, poly (acrylic amide) grafted onto sodium alginate (PAAm-g-SA) were successfully synthesized and then TGA capped CdTe QDs (CdTe-TGA QDs) were embed into it. The prepared CdTe-PAAm-g-SA QDs were optimized and characterized by transmission electron microscopy (TEM), thermo-gravimetric (TG) analysis, Fourier transform infrared (FT-IR), UV–vis and fluorescence spectroscopy. The characterization results indicated that CdTe-TGA QDs, with particles size of 2.90 nm, were uniformly dispersed on the chains of PAAm-g-SA biopolymer. CdTe-PAAm-g-SA QDs also exhibited excellent UV–vis absorption and high fluorescence intensity. To explore biological behavior of CdTe-PAAm-g-SA QDs, the interactions between CdTe-PAAm-g-SA QDs and human serum albumin (HSA) (or bovine serum albumin (BSA)) were investigated by cyclic voltammetry, FT-IR, UV–vis, and fluorescence spectroscopic. The results confirmed the formation of CdTe-PAAm-g-SA QDs-HSA (or BSA) complex with high binding affinities. The thermodynamic parameters (ΔG < 0, ΔH < 0 and ΔS < 0) were indicated that binding reaction was spontaneous and van der Waals interactions and hydrogen-bond interactions played a major role in stabilizing the CdTe-PAAm-g-SA QDs-HSA (or BSA) complexes. The binding distance between CdTe-PAAm-g-SA QDs and HSA (or BSA)) was calculated about 1.37 nm and 1.27 nm, respectively, according to Forster non-radiative energy transfer theory (FRET). Analyzing FT-IR spectra showed that the formation of QDs-HSA and QDs-BSA complexes led to conformational changes of the HSA and BSA proteins. All these experimental results clarified the effective transportation and elimination of CdTe-PAAm-g-SA QDs in the body by binding to HSA and BSA, which could be a useful guideline for the estimation of QDs as a drug carrier. - Highlights: • The CdTe quantum dots coated with polyacrylamide grafted onto sodium alginate. • The

  1. Arabidopsis genes, AtNPR1, AtTGA2 and AtPR-5, confer partial resistance to soybean cyst nematode (Heterodera glycines) when overexpressed in transgenic soybean roots

    Science.gov (United States)

    2014-01-01

    Background Extensive studies using the model system Arabidopsis thaliana to elucidate plant defense signaling and pathway networks indicate that salicylic acid (SA) is the key hormone triggering the plant defense response against biotrophic and hemi-biotrophic pathogens, while jasmonic acid (JA) and derivatives are critical to the defense response against necrotrophic pathogens. Several reports demonstrate that SA limits nematode reproduction. Results Here we translate knowledge gained from studies using Arabidopsis to soybean. The ability of thirty-one Arabidopsis genes encoding important components of SA and JA synthesis and signaling in conferring resistance to soybean cyst nematode (SCN: Heterodera glycines) are investigated. We demonstrate that overexpression of three of thirty-one Arabidoposis genes in transgenic soybean roots of composite plants decreased the number of cysts formed by SCN to less than 50% of those found on control roots, namely AtNPR1(33%), AtTGA2 (38%), and AtPR-5 (38%). Three additional Arabidopsis genes decreased the number of SCN cysts by 40% or more: AtACBP3 (53% of the control value), AtACD2 (55%), and AtCM-3 (57%). Other genes having less or no effect included AtEDS5 (77%), AtNDR1 (82%), AtEDS1 (107%), and AtPR-1 (80%), as compared to control. Overexpression of AtDND1 greatly increased susceptibility as indicated by a large increase in the number of SCN cysts (175% of control). Conclusions Knowledge of the pathogen defense system gained from studies of the model system, Arabidopsis, can be directly translated to soybean through direct overexpression of Arabidopsis genes. When the genes, AtNPR1, AtGA2, and AtPR-5, encoding specific components involved in SA regulation, synthesis, and signaling, are overexpressed in soybean roots, resistance to SCN is enhanced. This demonstrates functional compatibility of some Arabidopsis genes with soybean and identifies genes that may be used to engineer resistance to nematodes. PMID:24739302

  2. Thermogravimetric analysis of forest understory grasses

    Science.gov (United States)

    Thomas Elder; John S. Kush; Sharon M. Hermann

    2011-01-01

    Forest understory grasses are of significance in the initiation, establishment and maintenance of fire, whether used as a management tool or when occurring as wildfire. The fundamental thermal properties of such grasses are critical to their behavior in fire situations and have been investigated in the current work by the application of thermogravimetric analysis (TGA...

  3. Influence of Yb{sup 3+} on the structural, dielectric and magnetic properties of Mg{sub 0.7}Co{sub 0.3}Fe{sub 2}O{sub 4} nanocrystallites synthesized via co-precipitation route

    Energy Technology Data Exchange (ETDEWEB)

    Ejaz, Muhammad [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Mahmood, Azhar [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Khan, Muhammad Azhar, E-mail: azhar.khan@iub.edu.pk [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Hussain, Altaf [Department of Physics, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Sultan, Amber [Quaid-e-Azam Medical College, Bahawalpur 63100 (Pakistan); Mahmood, Asif [College of Engineering, Department of Chemical Engineering, King Saud University, Riyadh (Saudi Arabia); Chughtai, Adeel Hussain; Ashiq, Muhammad Naeem [Institute of Chemical Sciences, Bahauddin Zakaryia University, Multan 60800 (Pakistan); Warsi, Muhammad Farooq, E-mail: farooq.warsi@iub.edu.pk [Department of Chemistry, The Islamia University of Bahawalpur, Bahawalpur 63100 (Pakistan); Shakir, Imran [Sustainable Energy Technologies (SET) center, College of Engineering, King Saud University, PO-BOX 800, Riyadh 11421 (Saudi Arabia)

    2016-04-15

    A series of nanostructured ferrites having chemical composition Mg{sub 0.7}Co{sub 0.3}Yb{sub x}Fe{sub 2−x}O{sub 4} (x=0.0–0.08) was prepared by the chemical co-precipitation route. The synthesized samples were characterized by X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA), differential thermal analysis (DTA), vibrating sample magnetometer (VSM) and impedance analyzer. The analysis of XRD patterns confirmed the spinel structure and the crystallite size calculated by Scherer's formula was found in the range of 18–43 nm. The crystallite size was small enough to obtain considerable signal to noise ratio in the recording media. The lattice constant was increased from 8.362 Ǻ to 8.383 Ǻ as the Yb contents were increased in the magnesium-cobalt ferrites. The TGA and DTA were carried out for prepared sample to investigate the thermal decomposition process. Magnetization results obtained from VSM measurements elucidate that the substitution of rare earth ytterbium decreased the saturation magnetization and retentivity. The dielectric properties of the samples were studied at room temperature in the frequency range of 1 MHz to 3 GHz and the samples exhibited the dispersion in high frequency region. The dielectric constant (ε) and dielectric loss (tan δ) were decreased with the increased frequency and ytterbium doping. The dielectric parameters were explained on the basis of space charge distribution. The dielectric and magnetic parameters suggested that these nano-materials are potential candidates for switching and recording media applications. - Graphical abstract: Mg{sub 0.7}Co{sub 0.3}Yb{sub x}Fe{sub 2−x}O{sub 4} nanostructured spinel ferrites were prepared by chemical co-precipitation technique. The crystallite size was found in the range 18–43 nm. The substitutions of rare earth ytterbium decrease the saturation magnetization and retentivity. The dielectric parameters were explained on the basis of space charge distribution. The

  4. Pyrolysis of coal, biomass and their blends: performance assessment by thermogravimetric analysis.

    Science.gov (United States)

    Ferrara, Francesca; Orsini, Alessandro; Plaisant, Alberto; Pettinau, Alberto

    2014-11-01

    With the aim to support the experimental tests in a gasification pilot plant, the thermal decomposition of coal, biomass and their mixtures has been carried out through a thermogravimetric analysis (TGA) and a simplified kinetic analysis. The TGA of pure fuels indicates the low reactivity of South African coal and the relatively high reactivity of Sardinian Sulcis coal during pyrolysis. Among the tested fuels, biomass (stone pine wood chips) is the most reactive one. These results fully confirm those obtained during the experimental tests in the gasification pilot plant. As for the fuel blends, the analysis shows that the synergic effects between the considered coals and biomass are negligible when they are co-pyrolyzed. The results of the analysis confirm that TGA could be very useful to generally predict the gasification performance and to optimize the experimental campaigns in pilot-scale gasification plants. Copyright © 2014 Elsevier Ltd. All rights reserved.

  5. Assessment of a new method for the analysis of decomposition gases of polymers by a combining thermogravimetric solid-phase extraction and thermal desorption gas chromatography mass spectrometry.

    Science.gov (United States)

    Duemichen, E; Braun, U; Senz, R; Fabian, G; Sturm, H

    2014-08-08

    For analysis of the gaseous thermal decomposition products of polymers, the common techniques are thermogravimetry, combined with Fourier transformed infrared spectroscopy (TGA-FTIR) and mass spectrometry (TGA-MS). These methods offer a simple approach to the decomposition mechanism, especially for small decomposition molecules. Complex spectra of gaseous mixtures are very often hard to identify because of overlapping signals. In this paper a new method is described to adsorb the decomposition products during controlled conditions in TGA on solid-phase extraction (SPE) material: twisters. Subsequently the twisters were analysed with thermal desorption gas chromatography mass spectrometry (TDS-GC-MS), which allows the decomposition products to be separated and identified using an MS library. The thermoplastics polyamide 66 (PA 66) and polybutylene terephthalate (PBT) were used as example polymers. The influence of the sample mass and of the purge gas flow during the decomposition process was investigated in TGA. The advantages and limitations of the method were presented in comparison to the common analysis techniques, TGA-FTIR and TGA-MS. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Electroactive polymer gels based on epoxy resin

    Science.gov (United States)

    Samui, A. B.; Jayakumar, S.; Jayalakshmi, C. G.; Pandey, K.; Sivaraman, P.

    2007-04-01

    Five types of epoxy gels have been synthesized from common epoxy resins and hardeners. Fumed silica and nanoclay, respectively, were used as fillers and butyl methacrylate/acrylamide were used as monomer(s) for making interpenetrating polymer networks (IPNs) in three compositions. Swelling study, tensile property evaluation, dynamic mechanical thermal analysis, thermo-gravimetric analysis, scanning electron microscopy and electroactive property evaluation were done. The gels have sufficient mechanical strength and the time taken for bending to 20° was found to be 22 min for forward bias whereas it was just 12 min for reverse bias.

  7. Synthesis, characterization and antifungal studies of metalloquinolone [Cd2(nal2(phen2(Cl2

    Directory of Open Access Journals (Sweden)

    A. Debnath

    2014-12-01

    Full Text Available A novel dinuclear, distorted octahedral complex of nalidixic acid (nal with Cd(II metal ion with the formula [Cd2(Nal2(Phen2(Cl2] has been synthesized in the presence of N-containing heterocyclic ligand, 1,10-phenanthroline (phen. The synthesized metal complex was characterized using CHN analysis, Fourier transformed infra-red, thermo gravimetric analysis, differential scanning chalorimetry, nuclear magnetic resonance, ultra violet-visible and single-crystal X-ray diffraction. The newly synthesized complex shows more pronounced antifungal activity compared with the parent quinolone against four fungi, namely Pythium aphanidermatum, Sclerotinia rolfsii, Rhizoctonia solani and Rhizoctonia bataticola.

  8. Synthesis, characterization and antibacterial activity of some 5-aryl-1, 3-Diphenyl 1-4, 5-dihydro-1H-Pyrazoles

    International Nuclear Information System (INIS)

    Al-Bahtiti, Nawal Hassan

    2007-01-01

    The condensation of acetophenone (I) with arylaldehyde (II) was investigated and the resulting chalcones 2-Arylidene 1-Acetophenone (III) were reacted with phenyl hydrazine and acetic acid to produce substituted 5-aryl-1, 3-diphenyl-4, 5-dihydro-1H-Pyrazoles (IV). The structures of all products were studied by H-NMR, IR, thermal and elemental analysis. Thermo-gravimetric (TG) and differential thermal analysis (DTA) was applied to investigate the thermal behavior and structure of the synthesized compounds. 2-Pyrazolines (IV) exhibited moderate activity against Streptococcus faecalis ATCC 19433, Klebsiella pneumoniae ATCC 13883, Proteus vulgaris ATCC 25922, Shigella sonnei ATCC 25931 and Peseudom oaeruginosa ATCC 27853. (author)

  9. Physical Properties and Thermal Decomposition of Aqueous Solutions of 2-Amino-2-hydroxymethyl-1, 3-propanediol (AHPD)

    Science.gov (United States)

    Murshid, Ghulam; Shariff, Azmi Mohd; Lau, K. K.; Bustam, Mohammad Azmi; Ahmad, Faizan

    2011-10-01

    Physical properties such as density, viscosity, refractive index, surface tension, and thermal stability of 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD) were experimentally measured. All the experimental measurements were made over a wide range of temperatures from (298.15 to 333.15) K and AHPD concentrations of (1, 7, 13, 19, and 25) mass%. An overall decrease in all the measured physical properties was observed with increasing temperature. The experimental results are presented as a function of temperature and AHPD mass fraction. All the measured physical properties were correlated as a function of temperature. Thermal decomposition of pure and aqueous solutions of AHPD was investigated using a thermo-gravimetric analyzer (TGA) at a heating rate of 10 K · min-1.

  10. Pyrolysis characteristics of typical biomass thermoplastic composites

    Science.gov (United States)

    Cai, Hongzhen; Ba, Ziyu; Yang, Keyan; Zhang, Qingfa; Zhao, Kunpeng; Gu, Shiyan

    The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA) has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite.

  11. Pyrolysis characteristics of typical biomass thermoplastic composites

    Directory of Open Access Journals (Sweden)

    Hongzhen Cai

    Full Text Available The biomass thermoplastic composites were prepared by extrusion molding method with poplar flour, rice husk, cotton stalk and corn stalk. The thermo gravimetric analyzer (TGA has also been used for evaluating the pyrolysis process of the composites. The results showed that the pyrolysis process mainly consists of two stages: biomass pyrolysis and the plastic pyrolysis. The increase of biomass content in the composite raised the first stage pyrolysis peak temperature. However, the carbon residue was reduced and the pyrolysis efficiency was better because of synergistic effect of biomass and plastic. The composite with different kinds of biomass have similar pyrolysis process, and the pyrolysis efficiency of the composite with corn stalk was best. The calcium carbonate could inhibit pyrolysis process and increase the first stage pyrolysis peak temperature and carbon residue as a filling material of the composite. Keywords: Biomass thermoplastic composite, Calcium carbonate, Pyrolysis characteristic

  12. Factors influencing moisture analysis in the 3013 destructive examination surveillance program

    Energy Technology Data Exchange (ETDEWEB)

    Scogin, J. H. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2017-10-24

    Thermogravimetric analysis of a solid sample with mass spectrometry (TGA-MS) of the evolved gas is used in the destructive examination (DE) portion of the Integrated Surveillance Program to quantify the moisture content of the material stored in a 3013 container. As with any measurement determined from a small sample, the collection, storage, transportation, and handling of the sample can affect its ability to represent the properties of the bulk material. During the course of the DE program, questions have periodically arisen concerning the ability of the moisture sample to reflect reliably the actual moisture content of the entire material stored in the 3013 container. Most concerns are related to the ability to collect a representative sample and to preserve the moisture content of the sample between collection and analysis. Recent delays in analysis caused by maintenance issues with the TGA-MS instrument presented a unique opportunity to document and quantify the effects various factors have on the TGA-MS moisture measurement. This report will use recent data to document the effects that current sample collection and handling practices have on the TGA-MS moisture measurement. Some suggestions will be made which could improve the current sample collection and handling practices for the TGA-MS moisture measurement so that the analytical results more accurately reflect the moisture content of the material stored in the 3013 container.

  13. Factors influencing moisture analysis in the 3013 destructive examination surveillance program

    International Nuclear Information System (INIS)

    Scogin, J. H.

    2017-01-01

    Thermogravimetric analysis of a solid sample with mass spectrometry (TGA-MS) of the evolved gas is used in the destructive examination (DE) portion of the Integrated Surveillance Program to quantify the moisture content of the material stored in a 3013 container. As with any measurement determined from a small sample, the collection, storage, transportation, and handling of the sample can affect its ability to represent the properties of the bulk material. During the course of the DE program, questions have periodically arisen concerning the ability of the moisture sample to reflect reliably the actual moisture content of the entire material stored in the 3013 container. Most concerns are related to the ability to collect a representative sample and to preserve the moisture content of the sample between collection and analysis. Recent delays in analysis caused by maintenance issues with the TGA-MS instrument presented a unique opportunity to document and quantify the effects various factors have on the TGA-MS moisture measurement. This report will use recent data to document the effects that current sample collection and handling practices have on the TGA-MS moisture measurement. Some suggestions will be made which could improve the current sample collection and handling practices for the TGA-MS moisture measurement so that the analytical results more accurately reflect the moisture content of the material stored in the 3013 container.

  14. “Turn on” fluorescence enhancement of Zn octacarboxyphthaloyanine-graphene oxide conjugates by hydrogen peroxide

    Energy Technology Data Exchange (ETDEWEB)

    Shumba, Munyaradzi; Mashazi, Philani; Nyokong, Tebello, E-mail: t.nyokong@ru.ac.za

    2016-02-15

    Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates were characterized by absorption spectroscopy, transmission electron microscopy, fluorescence spectroscopy, X-ray diffraction, thermo gravimetric analysis and X-ray photon spectroscopy. The presence of reduced graphene oxide or graphene oxide resulted in the quenching (turn on) of Zn octacarboxy phthalocyanine fluorescence which can be explained by photoinduced electron transfer. Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates “turned on” fluorescence showed a linear response to hydrogen peroxide hence their potential to be used as sensors. The nanoprobe developed showed high selectivity towards hydrogen peroxide in the presence of physiological interferences.

  15. “Turn on” fluorescence enhancement of Zn octacarboxyphthaloyanine-graphene oxide conjugates by hydrogen peroxide

    International Nuclear Information System (INIS)

    Shumba, Munyaradzi; Mashazi, Philani; Nyokong, Tebello

    2016-01-01

    Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates were characterized by absorption spectroscopy, transmission electron microscopy, fluorescence spectroscopy, X-ray diffraction, thermo gravimetric analysis and X-ray photon spectroscopy. The presence of reduced graphene oxide or graphene oxide resulted in the quenching (turn on) of Zn octacarboxy phthalocyanine fluorescence which can be explained by photoinduced electron transfer. Zn octacarboxy phthalocyanine-reduced graphene oxide or graphene oxide conjugates “turned on” fluorescence showed a linear response to hydrogen peroxide hence their potential to be used as sensors. The nanoprobe developed showed high selectivity towards hydrogen peroxide in the presence of physiological interferences.

  16. New materials for biodiesel production. The use of MgAl hydrotalcites solid catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Joao F.P.; Puna, Jaime F.B.; Goncalves, L. [Instituto Superior de Engenharia de Lisboa (ISEL), Lisboa (Portugal). Chemical Engineering Dept.; Bordado, Joao C. [Instituto Superior Tecnico (IST), Lisboa (Portugal). Inst. of Biotechnology and Bioengineering

    2010-07-01

    This work, reports preliminary studies and experimental work done so far in this field, using new solid basic catalysts: Double oxides of Mg and Al, produced by the calcination, at high temperature, of MgAl lamellar structures, the hidrotalcites. A brief introduction of its characterization, utilisation and synthesis of these catalysts, experimental conditions, experimental results and respective conclusions are described, here, with specific detail. The oil treatment procedure, the biodiesel production and purification processes and their respective morphological and textural characterizations are also described, with appropriate tables and figures, using, for instance, SEM, X-Ray Diffraction, Thermo gravimetric analysis (TG) and Middle Infrared Spectroscopy (MIR). (orig.)

  17. Thermal Degradation of Lead Monoxide Filled Polymer Composite Radiation Shields

    International Nuclear Information System (INIS)

    Harish, V.; Nagaiah, N.

    2011-01-01

    Lead monoxide filled Isophthalate resin particulate polymer composites were prepared with different filler concentrations and investigated for physical, thermal, mechanical and gamma radiation shielding characteristics. This paper discusses about the thermo gravimetric analysis of the composites done to understand their thermal properties especially the effect of filler concentration on the thermal stability and degradation rate of composites. Pristine polymer exhibits single stage degradation whereas filled composites exhibit two stage degradation processes. Further, the IDT values as well as degradation rates decrease with the increased filler content in the composite.

  18. Thermal properties and water repellency of cotton fabric prepared through sol-gel method

    Directory of Open Access Journals (Sweden)

    Gu Jia-Li

    2016-01-01

    Full Text Available Cotton fabrics were treated by one-step sol-gel method. The pure silica hydrosol and phosphorus-doped hydrosol were prepared with the addition of a hydrophobic hexadecyltrimethoxysilane to decrease the surface energy of cotton fabric. The thermal properties and water repellency of treated cotton fabric were characterized by thermo-gravimetric analysis, micro combustion, limiting oxygen index, and contact angle measurement. The results showed that cotton fabric treated by phosphorus-doped silica hydrosol had excellent flame retardance, and the water repellence was apparently improved with the addition of hexadecyltrimethoxysilane.

  19. Fabrication of Mineralized Collagen from Bovine Waste Materials by Hydrothermal Method as Promised Biomaterials

    DEFF Research Database (Denmark)

    Sheikh, Faheem A.; Kanjwal, Muzafar Ahmed; Macossay, Javier

    2011-01-01

    In the present study, we aimed to produce mineralized-collagen by hydrothermal process. A simple method not depending on additional foreign chemicals has been employed to isolate the mineralized-collagen fibers from bovine waste. The process of extraction involves the use of hydrothermal method...... mineral content in the individual fibers. The X-ray diffraction showed the crystalline feature of the obtained nano-compounds. The thermo gravimetric analysis was used to differentiate between the collagen and mineral parts of obtained product. Overall, the results generously indicated production of well...

  20. Synthesis of flower-like sulfadiazine copper/polyvinyl pyrrolidone composite and its antimicrobial activities

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ping [Henan University, Key Laboratory for Special Functional Materials (China); Xu, Xiangmin [Yellow River Conservancy Technical Institute (China); Li, Binjie, E-mail: lbj821@163.com [Medical School of Henan University (China); Zhao, Yanbao [Henan University, Key Laboratory for Special Functional Materials (China)

    2015-09-15

    Flower-like sulfadiazine copper/polyvinyl pyrrolidone (SD-Cu/PVP) composite was synthesized at room temperature. Its structure and morphology were investigated by X-ray powder diffraction, scanning electron microscopy, thermo gravimetric analysis, Fourier transform infrared spectrometry, and the possible forming mechanism was discussed as well. In addition, its antibacterial activity toward the bacterial strains such as Staphylococcus aureus (S. aureus), Escherichia coli (E. coli), and Pseudomonas aeruginosa (P. aeruginosa) was evaluated by the minimum inhibitory concentration, the minimum bactericidal concentration, and cup diffusion method. Results suggested that the SD-Cu/PVP composite displayed selectively antibacterial activity for E. coli and P. aeruginosa than S. aureus.

  1. Growth and characterization of new nonlinear optical 1-phenyl-3-(4-dimethylamino phenyl) prop-2-en-1-one (PDAC) single crystals

    Science.gov (United States)

    Ravindraswami, K.; Janardhana, K.; Gowda, Jayaprakash; Moolya, B. Narayana

    2018-04-01

    Non linear optical 1-phenyl-3-(4-dimethylamino phenyl) prop-2-en-1-one (PDAC) was synthesized using Claisen - Schmidt condensation method and studied for optical nonlinearity with an emphasis on structure-property relationship. The structural confirmation studies were carried out using 1H-NMR, FT-IR and single crystal XRD techniques. The nonlinear absorption and nonlinear refraction parameters in z-scan with nano second laser pulses were obtained by measuring the profile of propagated beam through the samples. The real and imaginary parts of third-order bulk susceptibility χ(3) were evaluated. Thermo gravimetric analysis is carried out to investigate the thermal stability.

  2. Synthesis of C60(OH)18-20 in aqueous alkaline solution under O2-atmosphere

    International Nuclear Information System (INIS)

    Alves, Gustavo Catao; Ladeira, Luiz Orlando; Righi, Ariete; Krambrock, Klaus; Pinheiro, Mauricio Veloso B.; Calado, Hallen Daniel; Gil, Rossimiriam Pereira de Freitas

    2006-01-01

    In this work we report on an alternative synthesis of water-soluble fullerenes known as fullerols, aiming for biomedical applications. The synthesis is based on a process in which polyethylene glycol (PEG400) is used as phase-transfer catalyst between fullerene/benzene and aqueous NaOH solutions. The polyhydroxylation of the fullerenes occurs in the NaOH solution under a continuous flow of O 2 to enhance the reaction yield. The resulting compound was characterized with infrared spectroscopy, nuclear magnetic resonance, thermo-gravimetric analysis and optical absorption. The formation of C 60 (OH) 18-20 in high yields was confirmed. (author)

  3. Insights into pyrolysis and co-pyrolysis of biomass and polystyrene: Thermochemical behaviors, kinetics and evolved gas analysis

    International Nuclear Information System (INIS)

    Özsin, Gamzenur; Pütün, Ayşe Eren

    2017-01-01

    Highlights: • TGA/MS/FT-IR was used to explore effect of polystyrene on pyrolytic decomposition of biomass. • The model-free iso-conversional methods were used for kinetic analysis. • Interactions occurred depending on the characteristics of the biomass. • TGA/MS and TGA/FT-IR coupling were used for gas analysis of co-pyrolysis for the first time. - Abstract: The purpose of this study was to investigate the effect on polystyrene (PS) during co-pyrolysis with biomass through thermal decomposition. The model-free iso-conversional methods (Kissinger, Friedman, Flynn-Wall-Ozawa, Kissinger-Akahira-Sunose, Starink and Vyazovkin) were adopted to calculate activation energy of the pyrolysis and co-pyrolysis process of two biomass samples (walnut shell: WS and peach stones: PST) with PS. It is found that biomass blending to PS decreased activation energy values and resulted in multi-step reaction mechanisms. Furthermore, changes in the evolution profiles of methyl, water, methoxy, carbon dioxide, benzene and styrene was monitored through evolved gas analysis via TGA/FT-IR and TGA/MS. Detection of temperature dependent release of volatiles indicated the differences occur as a result of compositional differences of biomass.

  4. Soil archives of a Fluvisol, part II. Archaeostratigraphical model of the subsurface of the medieval city centre of Vlaardingen, the Netherlands

    Science.gov (United States)

    Kluiving, Sjoerd; De Ridder, Tim; van Dasselaar, Marcel; Prins, Maarten

    2017-04-01

    In Medieval times the city of Vlaardingen (the Netherlands) was strategically located on the confluence of three rivers, the Meuse, the Merwede and the Vlaarding. A church of early 8th century was already located here. In a short period of time Vlaardingen developed into an international trading place, the most important place in the former county of Holland. Starting from the 11th century the river Meuse threatened to flood the settlement. These floods have been registered in the archives of the fluvisol and were recognised in a multidisciplinary sedimentary analysis of these archives. To secure the future of this vulnerable soil archive an extensive interdisciplinary research (76 mechanical drill holes, grain size analysis (GSA), thermo-gravimetric analysis (TGA), archaeological remains, soil analysis, dating methods, micromorphology, and microfauna has started in 2011 to gain knowledge on the sedimentological and pedological subsurface of the mound as well as on the well-preserved nature of the archaeological evidence. Pedogenic features are recorded with soil descriptive, micromorphological and geochemical (XRF) analysis. The soil sequence of 5 meters thickness exhibits a complex mix of 'natural' as well as 'anthropogenic layering' and initial soil formation that enables to make a distinction for relatively stable periods between periods with active sedimentation. In this paper the results of this large-scale project are demonstrated in a number of cross-sections with interrelated geological, pedological and archaeological stratification. Distinction between natural and anthropogenic layering is made on the occurrence of chemical elements phosphor and potassium. A series of four stratigraphic / sedimentary units record the period before and after the flooding disaster. Given the many archaeological remnants and features present in the lower units, we know that the medieval landscape was drowned while it was inhabited in the 12th century AD. After a final

  5. Using thermal analysis techniques for identifying the flash point temperatures of some lubricant and base oils

    Directory of Open Access Journals (Sweden)

    Aksam Abdelkhalik

    2018-03-01

    Full Text Available The flash point (FP temperatures of some lubricant and base oils were measured according to ASTM D92 and ASTM D93. In addition, the thermal stability of the oils was studied using differential scanning calorimeter (DSC and thermogravimetric analysis (TGA under nitrogen atmosphere. The DSC results showed that the FP temperatures, for each oil, were found during the first decomposition step and the temperature at the peak of the first decomposition step was usually higher than FP temperatures. The TGA results indicated that the temperature at which 17.5% weigh loss take placed (T17.5% was nearly identical with the FP temperature (±10 °C that was measured according to ASTM D92. The deviation percentage between FP and T17.5% was in the range from −0.8% to 3.6%. Keywords: Flash point, TGA, DSC

  6. Purity Evaluation of Single-Walled Carbon Nanotubes Using Thermogravimetric Analysis

    International Nuclear Information System (INIS)

    Goak, Jeung Choon; Kim, Tae Yang; Jung, Jongwan; Seo, Young-Soo; Lee, Naesung; Sok, Junghyun

    2013-01-01

    This study evaluated the purity of single-walled carbon nanotubes (SWCNTs) in the arc-synthesized SWCNT samples by using thermogravimetric analysis (TGA). The as-produced SWCNT samples were heat-treated in air for 20 h at 275-475°C and characterized by scanning and transmission electron microscopes and TGA to establish oxidation temperature ranges of SWCNTs and carbonaceous impurities comprising the samples. Based on these oxidation temperature ranges, derivative thermogravimetric curves were deconvoluted, and differentiated peaks were assigned to SWCNTs and carbonaceous impurities. The compositions and the SWCNT purities of the samples were obtained simply by calculating the areal ratios under the deconvoluted curves. TGA studies on purity evaluation and thermal stabilities of SWCNTs and carbonaceous impurities are likely to provide us with a simple route of thermal oxidation purification to acquire high-purity SWCNT samples.

  7. Characterization of Amazon fibers of the peach palm, balsa, and babassu by XDR, TGA and NMR; Caracterizacao das fibras amazonicas de pupunha, babacu e balsa atraves de DRX, TG e RMN

    Energy Technology Data Exchange (ETDEWEB)

    Martins, Maria A.; Marconcini, Jose M., E-mail: mariaalice@cnpdia.embrapa.br [Embrapa Instrumentacao, Sao Carlos-SP (Brazil); Morelli, Carolina L.; Marinelli, Alessandra L.; Bretas, Rosario E.S. [Universidade Federal de Sao Carlos - UFSCar, Sao Carlos, SP (Brazil)

    2011-07-01

    The aim of this work was to present the results by testing X-ray diffraction (XRD), thermogravimetric analysis (TG), nuclear magnetic resonance (NMR) and determining the moisture content of the peach palm, balsa and babassu fibers for assessing the feasibility of composite materials. The fibers of peach palm, balsa and babassu showed characteristic chemical structure of lignocellulosic material, and good thermal stability up to 220 deg C. The fiber with the highest crystallinity index (Ic) is the peach palm (72%) and the less crystalline is the babassu (37%), while the balsa fibers have Ic equal to 64%. The results have shown that these fibers can be used in the manufacture of composite materials. (author)

  8. Structural, thermal and optical behavior of 84 MeV oxygen and 120 MeV silicon ions irradiated PES

    International Nuclear Information System (INIS)

    Samra, Kawaljeet Singh; Thakur, Sonika; Singh, Lakhwant

    2011-01-01

    In order to study structural, thermal and optical behavior, thin flat samples of polyethersulfone were irradiated with oxygen and silicon ions. The changes in properties were analyzed using different techniques viz: X-ray diffraction, thermo-gravimetric analysis, Fourier transform infrared, UV-visible and photoluminescence spectroscopy. A noticeable increase in the intensity of X-ray diffraction peaks was observed after irradiation with 84 MeV oxygen ions at low and medium fluences, which may be attributed to radiation-induced cross-linking in polymer. Fourier transform infrared and thermo-gravimetric analysis corroborated the results of X-ray diffraction analysis. No noticeable change in the Fourier transform infrared spectra of oxygen ion irradiated polyethersulfone were observed even at the highest fluence of 1 x 10 13 ions cm -2 , but after irradiation with silicon ions, a reduction in intensity of almost all characteristic bands was revealed. An increase in the activation energy of decomposition of polyethersulfone was observed after irradiation with 84 MeV oxygen ions up to medium fluences but degradation was revealed at higher fluences. Similar trends were observed by photoluminescence analysis.

  9. Performance evaluation of gamma irradiated SiR-EPDM blends

    Energy Technology Data Exchange (ETDEWEB)

    Deepalaxmi, R., E-mail: deepalaxmivaithi@gmail.com; Rajini, V.

    2014-07-01

    R-EPDM blends under a normal as well as in radiation environment, thermal analysis has been done using differential scanning calorimetry (DSC) and thermo-gravimetric analysis (TGA). The morphological changes occurred on the surface of the virgin and gamma irradiated SiR-EPDM blends were investigated through the scanning electron microscopy (SEM) analysis. The blend C and the EPDM rich blends (D and E) are found to have the superior performance when compared with SiR rich blends (A and B). Hence among the three different compositions of EPDM rich blends, suitable blend can be selected for a particular NPP application.

  10. Facile fabrication of Fe{sub 3}O{sub 4} and Co{sub 3}O{sub 4} microspheres and their influence on the thermal decomposition of ammonium perchlorate

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yifu, E-mail: yfzhang@dlut.edu.cn; Meng, Changgong

    2016-07-25

    Fe{sub 3}O{sub 4} and Co{sub 3}O{sub 4} microspheres were successfully synthesized by the hydrothermal decomposition of iron oxalate and cobalt oxalate solution. The composition and morphology of synthesized powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The catalytic properties of the as-obtained Fe{sub 3}O{sub 4} and Co{sub 3}O{sub 4} microspheres on the thermal decomposition of ammonium perchlorate (AP) were evaluated by thermo-gravimetric analysis and differential thermal analysis (TGA/DTA) methods. The thermal decomposition temperatures of AP in the presence of 1, 2, 4 and 8 wt% of Fe{sub 3}O{sub 4} microspheres were respectively decreased by 58, 80, 102 and 129 °C (lowered to 398, 376, 354 and 327 °C). And the thermal decomposition temperatures of AP in the presence of 1, 2, 4 and 8 wt% of Co{sub 3}O{sub 4} microspheres were respectively decreased by 55, 74, 112 and 131 °C (lowered to 401, 382, 344 and 325 °C). The analysis of the thermal gravimetric analyzer couplet with infrared spectroscopy (TG-IR) test reveal that the additives can accelerate the thermal decomposition of AP via the high-temperature decomposition. All the results suggest the as-prepared Fe{sub 3}O{sub 4} and Co{sub 3}O{sub 4} microspheres have highly catalytic properties on the thermal decomposition of AP, which can be used as the promising additives in the future. - Graphical abstract: Real-time FTIR spectra to reveal the thermal decomposition process of AP. - Highlights: • Highly uniform Fe{sub 3}O{sub 4} and Co{sub 3}O{sub 4} microspheres were successfully synthesized. • The T{sub c} of AP with 1, 2, 4 and 8 wt% of Fe{sub 3}O{sub 4} microspheres was decreased by 58, 80, 102 and 129 °C. • The T{sub c} of AP with 1, 2, 4 and 8 wt% of Co{sub 3}O{sub 4} microspheres was decreased by 55, 74, 112 and 131 °C. • The thermal decomposition process of AP was detected by TG-IR.

  11. Facile fabrication of Fe_3O_4 and Co_3O_4 microspheres and their influence on the thermal decomposition of ammonium perchlorate

    International Nuclear Information System (INIS)

    Zhang, Yifu; Meng, Changgong

    2016-01-01

    Fe_3O_4 and Co_3O_4 microspheres were successfully synthesized by the hydrothermal decomposition of iron oxalate and cobalt oxalate solution. The composition and morphology of synthesized powders were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The catalytic properties of the as-obtained Fe_3O_4 and Co_3O_4 microspheres on the thermal decomposition of ammonium perchlorate (AP) were evaluated by thermo-gravimetric analysis and differential thermal analysis (TGA/DTA) methods. The thermal decomposition temperatures of AP in the presence of 1, 2, 4 and 8 wt% of Fe_3O_4 microspheres were respectively decreased by 58, 80, 102 and 129 °C (lowered to 398, 376, 354 and 327 °C). And the thermal decomposition temperatures of AP in the presence of 1, 2, 4 and 8 wt% of Co_3O_4 microspheres were respectively decreased by 55, 74, 112 and 131 °C (lowered to 401, 382, 344 and 325 °C). The analysis of the thermal gravimetric analyzer couplet with infrared spectroscopy (TG-IR) test reveal that the additives can accelerate the thermal decomposition of AP via the high-temperature decomposition. All the results suggest the as-prepared Fe_3O_4 and Co_3O_4 microspheres have highly catalytic properties on the thermal decomposition of AP, which can be used as the promising additives in the future. - Graphical abstract: Real-time FTIR spectra to reveal the thermal decomposition process of AP. - Highlights: • Highly uniform Fe_3O_4 and Co_3O_4 microspheres were successfully synthesized. • The T_c of AP with 1, 2, 4 and 8 wt% of Fe_3O_4 microspheres was decreased by 58, 80, 102 and 129 °C. • The T_c of AP with 1, 2, 4 and 8 wt% of Co_3O_4 microspheres was decreased by 55, 74, 112 and 131 °C. • The thermal decomposition process of AP was detected by TG-IR.

  12. Covalent immobilization of porcine pancreatic lipase on carboxyl-activated magnetic nanoparticles: Characterization and application for enzymatic inhibition assays

    International Nuclear Information System (INIS)

    Zhu, Yuan-Ting; Ren, Xiao-Yun; Liu, Yi-Ming; Wei, Ying; Qing, Lin-Sen; Liao, Xun

    2014-01-01

    Using carboxyl functionalized silica-coated magnetic nanoparticles (MNPs) as carrier, a novel immobilized porcine pancreatic lipase (PPL) was prepared through the 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling reaction. Transmission electron microscopic images showed that the synthesized nanoparticles (Fe 3 O 4 –SiO 2 ) possessed three dimensional core–shell structures with an average diameter of ∼ 20 nm. The effective enzyme immobilization onto the nanocomposite was confirmed by atomic force microscopic (AFM) analysis. Results from Fourier-transform infrared spectroscopy (FT-IR), Bradford protein assay, and thermo-gravimetric analysis (TGA) indicated that PPL was covalently attached to the surface of magnetic nanoparticles with a PPL immobilization yield of 50 mg enzyme/g MNPs. Vibrating sample magnetometer (VSM) analysis revealed that the MNPs-PPL nanocomposite had a high saturation magnetization of 42.25 emu·g −1 . The properties of the immobilized PPL were investigated in comparison with the free enzyme counterpart. Enzymatic activity, reusability, thermo-stability, and storage stability of the immobilized PPL were found significantly superior to those of the free one. The K m and the V max values (0.02 mM, 6.40 U·mg −1 enzyme) indicated the enhanced activity of the immobilized PPL compared to those of the free enzyme (0.29 mM, 3.16 U·mg −1 enzyme). Furthermore, at an elevated temperature of 70 °C, immobilized PPL retained 60% of its initial activity. The PPL-MNPs nanocomposite was applied in the enzyme inhibition assays using orlistat, and two natural products isolated from oolong tea (i.e., EGCG and EGC) as the test compounds. - Highlights: • Porcine pancreatic lipase was firstly covalently immobilized onto carboxylated MNPs. • Immobilized porcine pancreatic lipase (PPL) was characterized by various techniques. • MNPs-PPL showed higher activity, reusability, and thermo-stability than

  13. Covalent immobilization of porcine pancreatic lipase on carboxyl-activated magnetic nanoparticles: Characterization and application for enzymatic inhibition assays

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, Yuan-Ting [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Ren, Xiao-Yun [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China); Liu, Yi-Ming [Department of Chemistry and Biochemistry, Jackson State University, 1400 Lynch St., Jackson, MS 39217 (United States); Wei, Ying [Changzhi Medical College, Changzhi 046000 (China); Qing, Lin-Sen [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China); Liao, Xun, E-mail: liaoxun@cib.ac.cn [Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu 610041 (China)

    2014-05-01

    Using carboxyl functionalized silica-coated magnetic nanoparticles (MNPs) as carrier, a novel immobilized porcine pancreatic lipase (PPL) was prepared through the 1-ethyl-3-[3-dimethylaminopropyl] carbodiimide hydrochloride/N-hydroxysuccinimide (EDC/NHS) coupling reaction. Transmission electron microscopic images showed that the synthesized nanoparticles (Fe{sub 3}O{sub 4}–SiO{sub 2}) possessed three dimensional core–shell structures with an average diameter of ∼ 20 nm. The effective enzyme immobilization onto the nanocomposite was confirmed by atomic force microscopic (AFM) analysis. Results from Fourier-transform infrared spectroscopy (FT-IR), Bradford protein assay, and thermo-gravimetric analysis (TGA) indicated that PPL was covalently attached to the surface of magnetic nanoparticles with a PPL immobilization yield of 50 mg enzyme/g MNPs. Vibrating sample magnetometer (VSM) analysis revealed that the MNPs-PPL nanocomposite had a high saturation magnetization of 42.25 emu·g{sup −1}. The properties of the immobilized PPL were investigated in comparison with the free enzyme counterpart. Enzymatic activity, reusability, thermo-stability, and storage stability of the immobilized PPL were found significantly superior to those of the free one. The K{sub m} and the V{sub max} values (0.02 mM, 6.40 U·mg{sup −1} enzyme) indicated the enhanced activity of the immobilized PPL compared to those of the free enzyme (0.29 mM, 3.16 U·mg{sup −1} enzyme). Furthermore, at an elevated temperature of 70 °C, immobilized PPL retained 60% of its initial activity. The PPL-MNPs nanocomposite was applied in the enzyme inhibition assays using orlistat, and two natural products isolated from oolong tea (i.e., EGCG and EGC) as the test compounds. - Highlights: • Porcine pancreatic lipase was firstly covalently immobilized onto carboxylated MNPs. • Immobilized porcine pancreatic lipase (PPL) was characterized by various techniques. • MNPs-PPL showed higher activity

  14. Chemical looping coal gasification with calcium ferrite and barium ferrite via solid–solid reactions

    International Nuclear Information System (INIS)

    Siriwardane, Ranjani; Riley, Jarrett; Tian, Hanjing; Richards, George

    2016-01-01

    Highlights: • BaFe 2 O 4 and CaFe 2 O 4 are excellent for chemical looping coal gasification. • BaFe 2 O 4 and CaFe 2 O 4 have minimal reactivity with synthesis gas. • Steam enhances the gasification process with these oxygen carriers. • Reaction rates of steam gasification of coal with CaFe 2 O 4 was better than with gaseous oxygen. • Coal gasification appears to be via solid–solid interaction with the oxygen carrier. - Abstract: Coal gasification to produce synthesis gas by chemical looping was investigated with two oxygen carriers, barium ferrite (BaFe 2 O 4 ) and calcium ferrite (CaFe 2 O 4 ). Thermo-gravimetric analysis (TGA) and fixed-bed flow reactor data indicated that a solid–solid interaction occurred between oxygen carriers and coal to produce synthesis gas. Both thermodynamic analysis and experimental data indicated that BaFe 2 O 4 and CaFe 2 O 4 have high reactivity with coal but have a low reactivity with synthesis gas, which makes them very attractive for the coal gasification process. Adding steam increased the production of hydrogen (H 2 ) and carbon monoxide (CO), but carbon dioxide (CO 2 ) remained low because these oxygen carriers have minimal reactivity with H 2 and CO. Therefore, the combined steam–oxygen carrier produced the highest quantity of synthesis gas. It appeared that neither the water–gas shift reaction nor the water splitting reaction promoted additional H 2 formation with the oxygen carriers when steam was present. Wyodak coal, which is a sub-bituminous coal, had the best gasification yield with oxygen carrier–steam while Illinois #6 coal had the lowest. The rate of gasification and selectivity for synthesis gas production was significantly higher when these oxygen carriers were present during steam gasification of coal. The rates and synthesis gas yields during the temperature ramps of coal–steam with oxygen carriers were better than with gaseous oxygen.

  15. Characterization of mechano-thermally synthesized Curie temperature-adjusted La0.8Sr0.2MnO3 nanoparticles coated with (3-aminopropyl) triethoxysilane

    International Nuclear Information System (INIS)

    Salili, S.M.; Ataie, A.; Barati, M.R.; Sadighi, Z.

    2015-01-01

    This research aimed to synthesize nanostructured strontium-doped lanthanum manganite, La 0.8 Sr 0.2 MnO 3 (LSMO), with its Curie temperature (T c ) adjusted to the therapeutic range, through a mechanothermal route. In order to investigate the effect of heat treatment temperature and duration on the resulting crystallite size, morphology, magnetic behavior and Curie temperature, the starting powder mixture was milled in a planetary ball mill before being subsequently heat treated at distinct temperatures for different time lengths. The composition, morphology, and magnetic behavior were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED) and vibrating sample magnetometer (VSM). In addition, magnetic properties were further investigated using an alternating current (AC) susceptometer and thermo-magnetic analyzer. 20 h of milling produced a crystallite size reduction leading to a decrease in the heat treatment temperature of LSMO synthesis to 800 °C. Moreover, SEM analysis has shown the morphology of a strong agglomeration of fine nanoparticles. HRTEM showed clear lattice fringes of high crystallinity. The mean crystallite and particle size of 20-hour milled sample heat treated at 1100 °C for 10 h are relatively 69 and 100 nm, respectively. The VSM data at room temperature, indicated a paramagnetic behavior for samples heat treated at 800 °C. However, by increasing heat treatment temperature to 1100 °C, LSMO indicates a ferromagnetic behavior with well-adjusted Curie temperature of 320 K, suitable for hyperthermia applications. Also, reentrant spin glass (RSG) behavior has been found in heat treated samples. The particles are coated with (3-aminopropyl) triethoxysilane (APTES) for biocompatibility purposes; Fourier transform infrared spectroscopy (FTIR) and thermo-gravimetric analysis (TGA) are

  16. Ultrasound assisted synthesis of Mn3O4 nanoparticles anchored graphene nanosheets for supercapacitor applications

    International Nuclear Information System (INIS)

    Raj, Balasubramaniam Gnana Sundara; Ramprasad, Rajasekharan Nair Radhika; Asiri, Abdullah M.; Wu, Jerry J; Anandan, Sambandam

    2015-01-01

    Highlights: • Room temperature synthesis of Mn 3 O 4 –graphene (MG) composite via ultra sound assisted method. • TEM images shows Mn 3 O 4 nanoparticles are uniformly distributed on the surface of graphene nanosheets. • MG composite exhibited high specific capacitance of 312 F g −1 in 1 M Na 2 SO 4 which was three times greater than pristine Mn 3 O 4 . • 76% of the initial capacitance was retained even after 1000 cycles. • The higher specific capacitance of the MG nanocomposite due to the synergistic effect between the Mn 3 O 4 nanoparticles and graphene nanosheets. - Abstract: Mn 3 O 4 nanoparticles anchored graphene nanosheets (MG) have been successfully synthesized by a simple ultrasound assisted synthesis at room temperature without the use of any templates or surfactants for supercapacitor applications. Upon ultrasound assisted synthesis, the formation of Mn 3 O 4 nanoparticles and the graphene oxide reduction occurs simultaneously. The crystalline structure of thus prepared MG nanocomposite have been characterized by the powder X-ray diffraction (XRD) analysis. Thermo Gravimetric Analysis (TGA) is used to determine the mass content of graphene (17 wt%) in the MG nanocomposite. Transmission electron microscopy (TEM) and Atomic force microscopy (AFM) studies shows that the Mn 3 O 4 nanoparticles (4–8 nm) were uniformly anchored on the surface of graphene nanosheets. The electrochemical properties of the MG nanocomposite were investigated by employing cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). The capacitive properties of MG nanocomposite studied in the presence of 1 M Na 2 SO 4 exhibited high specific capacitance of 312 F g −1 which was approximately three times greater than that of pristine Mn 3 O 4 (113 F g −1 ) at the same current density of 0.5 mA cm −2 in the potential range from -0.1 to +0.9 V. About 76% of the initial capacitance was retained even after 1000 cycles

  17. Studies on Benzo-DODA encapsulated polymeric beads for separation of Pu from acidic solution

    International Nuclear Information System (INIS)

    Singh, K.K.; Panja, S.; Kumar, M.; Ruhela, R.; Tripathi, S.C.; Singh, A.K.; Hubli, R.C.; Bajaj, P.N.

    2014-01-01

    High level liquid waste (HLLW) generated during the reprocessing of spent fuel contains a few mg of Pu per litre of waste volume. Therefore, there is a need for selective separation of Pu from above solution as well as other such acidic waste streams. The widely used technology for separation and recovery of metal ions from radioactive wastes is liquid-liquid extraction.Though, such technologies play major role in all the bulk separation processes, they have marked limitations involving the losses of extractant in aqueous phase, third phase problems at higher metal loading, etc. These limitations have necessitated the exploration of advance, more efficient and technically feasible alternatives. In this regard it is thought that solid-liquid based Extractant Encapsulated Polymeric Beads (EEPBs) may solve some of the problems. Benzodioxodiamide (BenzoDODA) is a recently reported extractant for the separation of plutonium from radioactive waste, containing nitric acid. BenzoDODA extractant encapsulated polymeric beads were prepared by phase inversion technique and found to be quite stable as no significant structural deformation or leaching out of the extractant was observed in 4.0 M HNO 3 solution, up to studied equilibration time of 8 days. These beads have been characterized by FT-IR, TGA and SEM techniques to gain insight into their structure and morphology. Morphology and porosity of the beads, as studied by the SEM analysis, indicate that the surface of the beads is quite rough, and has enough porosity. Thermo gravimetric analysis of the synthesized composite beads shows a weight loss of ∼74% during the heating from room temperature to 120℃, due to the loss of water present in the swollen beads. Such high water content also confirms that the beads have enough porosity for efficient exchange of metal ions.The synthesized beads were evaluated, for their ability to absorb Pu from acidic solution. The kinetics measurement showed that about 45 min of

  18. Preparation and characterization of highly water-soluble magnetic Fe{sub 3}O{sub 4} nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Li, Honghong; Qin, Li [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Feng, Ying [Department of Bridge Engineering, Shanxi Railway Institute, Weinan 714000 (China); Hu, Lihua [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China); Zhou, Chunhua, E-mail: chm_zhouch@ujn.edu.cn [School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022 (China)

    2015-06-15

    A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe{sub 3}O{sub 4} magnetic nanoparticles (Fe{sub 3}O{sub 4}-AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe{sub 3}O{sub 4}-AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe{sub 3}O{sub 4}-AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe{sub 3}O{sub 4}. Transmission electron microscopy (TEM) analysis confirmed that the Fe{sub 3}O{sub 4}-AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe{sub 3}O{sub 4}-MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe{sub 3}O{sub 4}-AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature T{sub B} of Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered AOS is 170 K. - Highlights: • Double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe{sub 3}O{sub 4} magnetic nanoparticles are prepared by a wet co-precipitation method. • Double-layered Fe{sub 3}O{sub 4}-AOS-MN exhibits highly water-solubility. • The iron oxide phase is determined by Raman spectroscopy. • Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered AOS possesses super-paramagnetic behavior. • The blocking temperature T{sub B} of Fe{sub 3}O{sub 4}-AOS-MN capped with double-layered AOS is 170 K.

  19. Effect of Dimethyl Ether Mixing on Soot Size Distribution in Premixed Ethylene Flame

    KAUST Repository

    Li, Zepeng

    2016-04-21

    As a byproduct of incomplete combustion, soot attracts increasing attentions as extensive researches exploring serious health and environmental effects from soot particles. Soot emission reduction requires a comprehensive understanding of the mechanism for polycyclic aromatic hydrocarbons and of soot formation and aging processes. Therefore, advanced experimental techniques and numerical simulations have been conducted to investigate this procedure. In order to investigate the effects of dimethyl ether (DME) mixing on soot particle size distribution functions (PSDFs), DME was mixed in premixed ethylene/oxygen/argon at flames at the equivalence ratio of 2.0 with a range of mixing ratio from 0% to 30% of the total carbon fed. Two series of atmospheric pressure flames were tested in which cold gas velocity was varied to obtain different flame temperatures. The evolution of PSDFs along the centerline of the flame was determined by burner stabilized stagnation probe and scanning mobility particle sizer (SMPS) techniques, yielding the PSDFs for various separation distances above the burner surface. Meanwhile, the flame temperature profiles were carefully measured by a thermocouple and the comparison to that of simulated laminar premixed burner-stabilized stagnation flame was satisfactory. Additionally, to understand the chemical role of DME mixing in soot properties, characterization measurements were conducted on soot samples using thermo-gravimetric analysis (TGA) and elemental analysis (EA). Results of the evolution of PSDFs and soot volume fraction showed that adding DME into ethylene flame could reduce soot yield significantly. The addition of DME led to the decrease of both the soot nucleation rate and the particle mass growth rate. To explain the possible mechanism for the observation, numerical simulations were performed. Although DME addition resulted in the slight increase of methyl radicals from pyrolysis, the decrease in acetylene and propargyl radicals

  20. Solid-state poly(ethylene glycol)-polyurethane/polymethylmethacrylate/rutile TiO2 nanofiber composite electrolyte-correlation between morphology and conducting properties

    International Nuclear Information System (INIS)

    Chilaka, Naresh; Ghosh, Sutapa

    2012-01-01

    Highlights: ► Semi IPN composite of PEG-PU/PMMA with different wt% of rutile TiO 2 is synthesized. ► Formation of nanocomposite is confirmed by SEM, XRD and IR spectroscopic analysis. ► DSC and TGA confirmed the enhanced thermal stability of the composite. ► Composite with 18 wt% rutile TiO 2 is found to be the best conducting material. - Abstract: A series of lithium electrolyte materials based on hybrid of semi Inter penetrating Polymer Network of [poly(ethylene glycol)-polyurethane-polymethylmethacrylate] [60:40] and TiO 2 nanofibers is described. TiO 2 nanofibers are made by simple solvothermal procedure. Rutile phase of TiO 2 and its fibrous morphology are confirmed by X-ray diffraction pattern and scanning electron microscopy image respectively. Semi Inter penetrating Polymer Network of polyethylene glycol-polyurethane/polymethylmethacrylate with LiClO 4 and its nanocomposite with different weight percent of TiO 2 nano fibers have been synthesized. The formation of Inter penetrating Polymer Network and its amorphous nature are confirmed by Fourier transform infrared spectra, X-ray diffraction pattern and differential scanning calorimetry results. Thermo gravimetric analysis shows enhanced thermal stability of the composite compared to the semi Inter penetrating Polymer Network system. The electrical characterizations of the nanocomposites are done by current–voltage (I–V) measurements and impedance spectroscopy. These results confirm that incorporation of TiO 2 nanofibers by 18% enhances the conductivity of the Inter penetrating Polymer Network system by ten times . The nanoscale structure of the inorganic material is found to be responsible for the bulk properties of the system, especially those that differ from the properties of similar, pure salt-in-polymer electrolytes. Further differential scanning calorimetry, scanning electron microscopy and impedance data confirm the presence of two polymeric phases in the semi Inter penetrating Polymer

  1. Preparation and characterization of highly water-soluble magnetic Fe3O4 nanoparticles via surface double-layered self-assembly method of sodium alpha-olefin sulfonate

    International Nuclear Information System (INIS)

    Li, Honghong; Qin, Li; Feng, Ying; Hu, Lihua; Zhou, Chunhua

    2015-01-01

    A kind of double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe 3 O 4 magnetic nanoparticles (Fe 3 O 4 -AOS-MN) with highly water-solubility was prepared by a wet co-precipitation method with a pH of 4.8. The resulting Fe 3 O 4 -AOS-MN could be dispersed into water to form stable magnetic fluid without other treatments. The result of X-ray diffraction (XRD) indicated that the Fe 3 O 4 -AOS-MN maintained original crystalline structure and exhibited a diameter of about 7.5 nm. The iron oxide phase of nanoparticles determined by Raman spectroscopy is Fe 3 O 4 . Transmission electron microscopy (TEM) analysis confirmed that the Fe 3 O 4 -AOS-MN with spherical morphology were uniformly dispersed in water. FT-IR spectroscopy (FT-IR) and thermo-gravimetric analysis (TGA) verified the successful preparation of Fe 3 O 4 -AOS-MN capped with double-layered self-assembled AOS. The corresponding capacities of monolayer chemical absorption and the second-layer self-assembly absorption were respectively 4.07 and 14.71 wt% of Fe 3 O 4 -MN, which were much lower than those of other surfactants. Vibrating sample magnetometer (VSM) test result showed Fe 3 O 4 -AOS-MN possessed superparamagnetic behavior with the saturation magnetization value of about 44.45 emu/g. The blocking temperature T B of Fe 3 O 4 -AOS-MN capped with double-layered AOS is 170 K. - Highlights: • Double-layered self-assembly sodium alpha-olefin sulfonate (AOS) capped Fe 3 O 4 magnetic nanoparticles are prepared by a wet co-precipitation method. • Double-layered Fe 3 O 4 -AOS-MN exhibits highly water-solubility. • The iron oxide phase is determined by Raman spectroscopy. • Fe 3 O 4 -AOS-MN capped with double-layered AOS possesses super-paramagnetic behavior. • The blocking temperature T B of Fe 3 O 4 -AOS-MN capped with double-layered AOS is 170 K

  2. Separation and analysis of low molecular weight plasticizers in poly(vinyl chloride) tubes

    DEFF Research Database (Denmark)

    Wang, Qian; Storm, Birgit Kjærside

    2005-01-01

    ) and thermogravimetric analysis (TGA), as well as by studying the extracted low molecular weight plasticizers by gas chromatography/mass spectroscopy (GC/MS) and GC. It was found that the simple room temperature extraction in chloroform showed the best separation of plasticizers from the PVC matrix. Close results...

  3. The Effect of Micro/Nano-metrics Size on the Interaction of Jordanian Aluminosilicate Raw Materials with High pH Solution

    Science.gov (United States)

    Aldabsheh, Islam; Garcia-Valles, Maite; Martinez, Salvador

    2014-05-01

    Environmental preservation has become a driving force behind the search for new sustainable and environmentally friendly composites to replace conventional concrete produced from ordinary Portland cement (OPC). Current researches concentrate on developing building products (geopolymers) through geopolymerization. The goal is to produce low cost construction materials for green housing. Geopolymerization is the process of polymerizing minerals with high silica and alumina at low temperature by the use of alkali solutions. Dissolution is the most important process for supplying the high initial Al and Si concentrations to produce the gel phase that is responsible for geopolymerization. This study has been focused on the influence of different micrometric particle sizes of three Jordanian raw materials on their dissolution behavior in sodium hydroxide solution. The samples are kaolinite, volcanic tuff and silica sand. The dissolution properties of each material, alone and mixed with the other two materials were studied in different concentrations (5 and 10 M) using (NaOH) at 25ºC, and shaking time for 24 and 168 h. To better understand the dissolution process, the alkaline solution was renewed after the desired time in order to know if the Al-Si raw material is completely dissolved or not. Different analytical techniques were used to characterize raw materials physically, mineralogically, chemically and thermally. All processed samples either centrifuged solutions or solid residues were fully characterized. The leached concentrations of Al and Si were determined by inductively coupled plasma (ICP). X-ray Diffraction Technique (XRD), Scanning Electron Microscopy (SEM), and Thermo Gravimetric Analysis (TGA) were used to evaluate the solid residue characterization compared with the original ones. The three aluminosilicate raw materials have indicated variable degrees of solubility under highly alkaline conditions. The method for the size reduction of the used raw

  4. Asphaltene-bearing mantle xenoliths from Hyblean diatremes, Sicily

    Science.gov (United States)

    Scirè, Salvatore; Ciliberto, Enrico; Crisafulli, Carmelo; Scribano, Vittorio; Bellatreccia, Fabio; Ventura, Giancarlo Della

    2011-08-01

    Microscopic blebs of sulfur-bearing organic matter (OM) commonly occur between the secondary calcite grains and fibrous phyllosilicates in extensively serpentinized and carbonated mantle-derived ultramafic xenoliths from Hyblean nephelinite diatremes, Sicily, Italy. Rarely, coarse bituminous patches give the rock a blackish color. Micro Fourier transform infrared spectra (μ-FTIR) point to asphaltene-like structures in the OM, due to partially condensed aromatic rings with aliphatic tails consisting of a few C atoms. X-ray photoelectron spectroscopy (XPS) analysis indicates the occurrence of minor S═O (either sulphonyl or sulphoxide) functional groups in the OM. Solubility tests in toluene, thermo-gravimetric (TGA) and differential thermal (DTA) analyses confirm the presence of asphaltene structures. It is proposed that asphaltenes derive from the in situ aromatization (with decrease in H/C ratio) of previous light aliphatic hydrocarbons. Field evidence excludes that hydrocarbon from an external source percolated through the xenolith bearing tuff-breccia. The discriminating presence of hydrocarbon in a particular type of xenolith only and the lack of hydrocarbon in the host breccia matrix, are also inconsistent with an interaction between the ascending eruptive system and a supposed deep-seated oil reservoir. Assuming that the Hyblean unexposed basement consists of mantle ultramafics and mafic intrusive rocks having hosted an early abyssal-type hydrothermal system, one can put forward the hypothesis that the hydrocarbon production was related to hydrothermal activity in a serpentinite system. Although a bacteriogenesis or thermogenesis cannot be ruled out, the coexisting serpentine, Ni-Fe ores and hydrocarbon strongly suggest a Fischer-Tropsch-type (FTT) synthesis. Subsequent variations in the chemical and physical conditions of the system, for example an increase in the water/rock ratio, gave rise to partial oxidation and late carbonation of the serpentinite

  5. Fiber from ramie plant (Boehmeria nivea): A novel suture biomaterial

    Energy Technology Data Exchange (ETDEWEB)

    Kandimalla, Raghuram; Kalita, Sanjeeb; Choudhury, Bhaswati [Drug discovery laboratory, Institute of Advanced Study in Science and Technology, Guwahati, Assam 781035 (India); Devi, Dipali [Seri biotech laboratory, Institute of Advanced Study in Science and Technology, Guwahati, Assam 781035 (India); Kalita, Dhaneswar [Government Ayurvedic College and Hospital, Jalukbari, Guwahati, Assam 781014 (India); Kalita, Kasturi [Department of Pathology, Hayat Hospital, Guwahati, Assam 781034 (India); Dash, Suvakanta [Girijananda Chowdhury Institute of pharmaceutical science, Azara, Guwahati, Assam 781017 (India); Kotoky, Jibon, E-mail: jkotoky@gmail.com [Drug discovery laboratory, Institute of Advanced Study in Science and Technology, Guwahati, Assam 781035 (India)

    2016-05-01

    The quest for developing an ideal suture material prompted our interest to develop a novel suture with advantageous characters to market available ones. From natural origin only silk, cotton and linen fibers are presently available in market as non-absorbable suture biomaterials. In this study, we have developed a novel, cost-effective, and biocompatible suture biomaterial from ramie plant, Boehmeria nivea fiber. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and thermo gravimetric analysis (TGA) results revealed the physicochemical properties of raw and degummed ramie fiber, where the former one showed desirable characteristics for suture preparation. The braided multifilament ramie suture prepared from degummed fiber exhibited excellent tensile strength. The suture found to be biocompatible towards human erythrocytes and nontoxic to mammalian cells. The fabricated ramie suture exhibited significant antibacterial activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus; which can be attributed to the inherent bacteriostatic ability of ramie plant fiber. In vivo wound closure efficacy was evaluated in adult male wister rats by suturing the superficial wound incisions. Within seven days of surgery the wound got completely healed leaving no rash and scar. The role of the ramie suture in complete wound healing was supported by the reduced levels of serum inflammatory mediators. Histopathology studies confirmed the wound healing ability of ramie suture, as rapid synthesis of collagen, connective tissue and other skin adnexal structures were observed within seven days of surgery. Tensile properties, biocompatibility and wound closure efficacy of the ramie suture were comparable with market available BMSF suture. The outcome of this study can drive tremendous possibility for the utilization of ramie plant fiber for

  6. Influence of the divalent and trivalent ions substitution on the structural and magnetic properties of Mg{sub 0.5−x}Cd{sub x}Co{sub 0.5}Cr{sub 0.04}Tb{sub y}Fe{sub 1.96−y}O{sub 4} ferrites prepared by sol–gel method

    Energy Technology Data Exchange (ETDEWEB)

    Mustafa, Ghulam, E-mail: ghulammustafabzu@gmail.com [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Islam, M.U. [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Zhang, Wenli [SKLETFID, University of Electronic Science and Technology of China, Chengdu 610054 (China); Anwar, Abdul Waheed [Department of Physics, University of Engineering and Technology, Lahore 54890 (Pakistan); Jamil, Yasir [Department of Physics, University of Agriculture, Faisalabad 38040 (Pakistan); Murtaza, Ghulam; Ali, Ihsan; Hussain, Mudassar [Department of Physics, Bahauddin Zakariya University, Multan 60800 (Pakistan); Ali, Akbar [Department of Basic Sciences, Riphah International University, Islamabad 44000 (Pakistan); Ahmad, Mukhtar, E-mail: ahmadmr25@yahoo.com [Department of Physics, COMSATS Institute of Information Technology, Islamabad 44000 (Pakistan)

    2015-08-01

    A series of the divalent and trivalent co-substituted Mg{sub 0.5−x}Cd{sub x}Co{sub 0.5}Cr{sub 0.04}Tb{sub y}Fe{sub 1.96−y}O{sub 4} spinel ferrite systems (where x=0–0.5 in steps of 0.1 and y=0.00–0.10 in steps 0.02) are synthesized by sol–gel auto combustion method. The product materials were characterized by the thermo gravimetric analysis and differential scanning calorimetry (TGA/DSC), Fourier transform infrared spectra (FTIR), nitrogen adsorption (BET), X-ray diffraction (XRD), scanning electron microscope (SEM), atomic force microscopy (AFM) and vibrating sample magnetometer (VSM). The X-ray diffraction patterns and Fourier transform infrared spectroscopy confirm spinel nanocrystalline phase. The crystallite size is determined by Scherer's formula from 36.6 to 69.4 nm. The X-ray density is found in the range of 5.09–6.43 (g/cm{sup 3}). The morphological features are studied using scanning electron microscope and AFM. Saturation magnetization (M{sub s}) and remanence (M{sub r}) magnetization extracted from M–H loops exhibit the decreasing trends 21.4–16 emu/g and 9.1–6.3 emu/g, respectively. A significant decrease in the intrinsic parameters is observed in the prepared samples due to the weakening of the A–B interaction as iron enters into the tetrahedral A-site. The coercivity lies in the range of 300–869 Oe as a function of co-substitution contents. The coercivity of the sample with x=0.1, y=0.02 was found maximum i.e. 869 Oe. The obtained results suggest that the investigated materials may be potential candidates for high density recording media applications. - Highlights: • Effects of co-substitution (Cd{sup 2+}, Tb{sup 3+}) on structural and magnetic parameters are studied. • XRD patterns revealed that first three samples are single phase while others are biphasic. • The M{sub s} was decreased from 21.4 to 16 emu/g with increasing co-substituted contents. • The values of coercivity lie in range of 300–869 Oe for all

  7. Physico-chemical and electrochemical characterization of Ti/RhO{sub x}-IrO{sub 2} electrodes using sol-gel technology

    Energy Technology Data Exchange (ETDEWEB)

    Klink, M.J.; Makgae, M.E. [Institute of Molecular Sciences, School of Chemistry, Faculty of Science, University of the Witwatersrand, Private Bag 3, Jorrissen Street, Johannesburg 2050 (South Africa); Crouch, A.M., E-mail: Andrew.Crouch@wits.ac.za [Institute of Molecular Sciences, School of Chemistry, Faculty of Science, University of the Witwatersrand, Private Bag 3, Jorrissen Street, Johannesburg 2050 (South Africa)

    2010-11-01

    Sol-gel technology has been successfully used for the incorporation of RhO{sub x}-IrO{sub 2} on a Ti substrate. RhO{sub x}-IrO{sub 2} was prepared from chloride precursors of Rh and Ir, for surface studies. These metal oxides were then immobilised on solid Ti substrates via dip withdrawal coating methods to form thin films. The Ti/RhO{sub x}-IrO{sub 2} thin films were extensively characterized in terms of surface characterization and chemical composition and used in the oxidation of phenol. Thermo-gravimetric analysis (TGA) determined the calcination temperature at 700 deg. C where no further structural changes occurred due to mass loss. The rhodium oxide showed two-phase formations, RhO{sub 2} and Rh{sub 2}O{sub 3}, which were attributed to high calcinated temperatures compare to one phase IrO{sub 2} which was stable at lower temperatures. The scanning electron microscopy (SEM) showed that the morphology of the film was found to be rough with a grain-like appearance in the 150-nm range. The phase composition of these metal oxides was determined by X-ray diffraction (XRD) technique and found to have crystalline structures. The results obtained from Rutherford backscattering spectrometry (RBS) revealed information regarding the chemical composition of the metal oxides and confirmed the diffusion of Rh and Ir into the Ti substrate. Electrochemical characterization of the Ti/RhO{sub x}-IrO{sub 2} electrode, via cyclic voltammetry (CV), showed distinctive redox peaks: anodic and cathodic peaks associated with the oxidation and reduction of the ferricyanide-ferrocyanide couple was seen at 250 and 100 mV respectively; the peak observed at 1000 mV was associated with oxygen evolution and a broad reductive wave at -600 mV can be ascribed to the Ti/RuO{sub x}-IrO{sub 2} reduction, which proved that the Ti/RhO{sub x}-IrO{sub 2} electrode were electroactive and exhibit fast electrochemistry.

  8. Energy efficient methane tri-reforming for synthesis gas production over highly coke resistant nanocrystalline Ni–ZrO_2 catalyst

    International Nuclear Information System (INIS)

    Singha, Rajib Kumar; Shukla, Astha; Yadav, Aditya; Adak, Shubhadeep; Iqbal, Zafar; Siddiqui, Nazia; Bal, Rajaram

    2016-01-01

    Highlights: • Tri-reforming of methane is an energy efficient process to produce synthesis gas. • Nanocrystalline Ni–ZrO_2 catalyst is prepared for tri-reforming of methane. • Strong metal-support interaction is the driving force for high activity. • The process produces synthesis gas with H_2/CO ratio of around 2. • The produced synthesis gas can be used to synthesize methanol. - Abstract: We report the synthesis of nanocrystalline Ni–ZrO_2 catalyst for tri-reforming of methane (5CH_4 + O_2 + CO_2 + 2H_2O → 6CO + 12H_2) to produce synthesis gas with H_2/CO mole ratio ∼2. Nanocrystalline Ni–ZrO_2 catalyst of size between 10 and 40 nm was prepared by hydrothermal method using cetyltrimethylammonium bromide (CTAB) as a surfactant. The prepared catalysts were characterized by N_2-physisorption studies, X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), temperature programmed reduction (TPR), H_2-chemisorpton, thermo-gravimetric analysis (TGA), Inductively coupled plasma atomic emission spectroscopy (ICP-AES) and X-ray photoelectron spectroscopy (XPS). The catalytic activity was monitored over temperature range between 500 and 800 °C. Different reaction parameters like temperature, Ni-loading, gas hourly space velocity (GHSV) and time on stream (TOS) were studied in detail. 4.8 wt% Ni loading for Ni–ZrO_2 catalyst was found to be the optimum Ni loading which showed the superior catalytic activity for methane tri-reforming. The catalyst was found to be stable for more than 100 h on time on stream with methane, carbon dioxide and steam conversion of ∼95% at 800 °C. The H_2/CO ratio was almost constant to 1.9 throughout the time on stream experiment. Highly dispersed nickel and the presence of strong metal support interaction were found to be the key factor for the superior activity of the catalyst. The effect of O_2 and H_2O concentration on reactant conversions and H_2/CO ratios were also

  9. Tailoring mechanical and antibacterial properties of chitosan/gelatin nanofiber membranes with Fe{sub 3}O{sub 4} nanoparticles for potential wound dressing application

    Energy Technology Data Exchange (ETDEWEB)

    Cai, Ning; Li, Chao; Han, Chao; Luo, Xiaogang [Key Laboratory for Green Chemical Process of Ministry of Education & Hubei Key Laboratory of Novel Reactor & Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073 (China); Shen, Liang [Department of Chemical and Biochemical Engineering, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen 361005 (China); Xue, Yanan [Key Laboratory for Green Chemical Process of Ministry of Education & Hubei Key Laboratory of Novel Reactor & Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073 (China); Yu, Faquan, E-mail: fyuwucn@gmail.com [Key Laboratory for Green Chemical Process of Ministry of Education & Hubei Key Laboratory of Novel Reactor & Green Chemical Technology, School of Chemical Engineering and Pharmacy, Wuhan Institute of Technology, Wuhan 430073 (China)

    2016-04-30

    Graphical abstract: - Highlights: • Fe{sub 3}O{sub 4} nanoparticles/chitosan (CS)/gelatin (GE) nanofibers were electrospun facilely. • Introducing Fe{sub 3}O{sub 4} enhanced mechanical and antibacterial properties of CS/GE nanofibers. • Mechanical enhancement relied on good filler dispersion and filler-matrix adhesion. • Fe{sub 3}O{sub 4}/CS/GE nanofiber membranes are promising candidates as wound dressings. - Abstract: In this work, magnetic Fe{sub 3}O{sub 4} nanoparticles (NPs) were utilized to improve the mechanical and antibacterial properties of chitosan (CS)/gelatin (GE) composite nanofiber membranes. Homogeneous Fe{sub 3}O{sub 4}/CS/GE nanofibers were electrospun successfully. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images confirmed the presence of well-dispersed Fe{sub 3}O{sub 4} NPs in the composite nanofibers. Fourier transform infrared spectroscopy (FTIR) spectra revealed the effective interactions of Fe{sub 3}O{sub 4} NPs to the composite matrix through hydrogen bonding. The improvement on the thermal stability of the Fe{sub 3}O{sub 4}/CS/GE was observed by differential scanning calorimetry (DSC) and thermo gravimetric analysis (TGA), which is tightly correlated to strong filler-matrix adhesion. The incorporation of Fe{sub 3}O{sub 4} NPs resulted in a substantial enhancement of mechanical properties. The optimum mechanical performance was demonstrated on 1 wt% Fe{sub 3}O{sub 4}/CS/GE nanofiber membranes, achieving 155% augment of Young's modulus, 128% increase of tensile strength, and 100% boost of toughness from CS/GE. The excellent mechanical enhancement can be explained by the effective dispersion of fillers and the filler-matrix interactions, which ensures the efficient load transfer from CS/GE matrix to Fe{sub 3}O{sub 4} nanofillers. Moreover, zones of inhibition for Escherichia coli and Staphylococcus aureus expanded markedly with the supplement of Fe{sub 3}O{sub 4} NPs. In all, nanofiber

  10. Fiber from ramie plant (Boehmeria nivea): A novel suture biomaterial

    International Nuclear Information System (INIS)

    Kandimalla, Raghuram; Kalita, Sanjeeb; Choudhury, Bhaswati; Devi, Dipali; Kalita, Dhaneswar; Kalita, Kasturi; Dash, Suvakanta; Kotoky, Jibon

    2016-01-01

    The quest for developing an ideal suture material prompted our interest to develop a novel suture with advantageous characters to market available ones. From natural origin only silk, cotton and linen fibers are presently available in market as non-absorbable suture biomaterials. In this study, we have developed a novel, cost-effective, and biocompatible suture biomaterial from ramie plant, Boehmeria nivea fiber. Field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and thermo gravimetric analysis (TGA) results revealed the physicochemical properties of raw and degummed ramie fiber, where the former one showed desirable characteristics for suture preparation. The braided multifilament ramie suture prepared from degummed fiber exhibited excellent tensile strength. The suture found to be biocompatible towards human erythrocytes and nontoxic to mammalian cells. The fabricated ramie suture exhibited significant antibacterial activity against Escherichia coli, Bacillus subtilis and Staphylococcus aureus; which can be attributed to the inherent bacteriostatic ability of ramie plant fiber. In vivo wound closure efficacy was evaluated in adult male wister rats by suturing the superficial wound incisions. Within seven days of surgery the wound got completely healed leaving no rash and scar. The role of the ramie suture in complete wound healing was supported by the reduced levels of serum inflammatory mediators. Histopathology studies confirmed the wound healing ability of ramie suture, as rapid synthesis of collagen, connective tissue and other skin adnexal structures were observed within seven days of surgery. Tensile properties, biocompatibility and wound closure efficacy of the ramie suture were comparable with market available BMSF suture. The outcome of this study can drive tremendous possibility for the utilization of ramie plant fiber for

  11. Infrared spectra, Raman laser, XRD, DSC/TGA and SEM ...

    Indian Academy of Sciences (India)

    Administrator

    cussed and the X-ray diffraction, scanning electron microscopy (SEM) and atomic force microscope (AFM) ... acetamide as a simple organic compound at high tempera- ture has less ..... properties of selenium surface, AFM-microscopy tapping.

  12. Infrared spectra, Raman laser, XRD, DSC/TGA and SEM ...

    Indian Academy of Sciences (India)

    Ga2O3, Se metal, SnO, Sb2O3, HgO and PbCO3 are formed upon the reaction of acetamide aqueous solutions with Ga(NO3)3, SeO2, SnCl2, SbCl3, HgCl2 and Pb(NO3)2, respectively, at 90°C. Different amorphous or crystalline phases can be obtained depending upon the experimental conditions (molar ratios, metal salts ...

  13. Functional characterization of tobacco transcription factor TGA2.1

    DEFF Research Database (Denmark)

    Kegler, C.; Lenk, I.; Krawczyk, S.

    2004-01-01

    Activation sequence-1 (as-1)-like regulatory cis elements mediate transcriptional activation in response to increased levels of plant signalling molecules auxin and salicylic acid (SA). Our earlier work has shown that tobacco cellular as-1-binding complex SARP (salicylic acid responsive protein...

  14. Pyrolytic characteristics of biomass acid hydrolysis residue rich in lignin.

    Science.gov (United States)

    Huang, Yanqin; Wei, Zhiguo; Yin, Xiuli; Wu, Chuangzhi

    2012-01-01

    Pyrolytic characteristics of acid hydrolysis residue (AHR) of corncob and pinewood (CAHR, WAHR) were investigated using a thermo-gravimetric analyzer (TGA) and a self-designed pyrolysis apparatus. Gasification reactivity of CAHR char was then examined using TGA and X-ray diffractometer. Result of TGA showed that thermal degradation curves of AHR descended smoothly along with temperature increasing from 150 °C to 850 °C, while a "sharp mass loss stage" for original biomass feedstock (OBF) was observed. Char yield from AHR (42.64-30.35 wt.%) was found to be much greater than that from OBF (26.4-19.15 wt.%). In addition, gasification reactivity of CAHR char was lower than that of corncob char, and there was big difference in micro-crystallite structure. It was also found that CAHR char reactivity decreased with pyrolysis temperature, but increased with pyrolysis heating rate and gasification temperature at 850-950 °C. Furthermore, CAHR char reactivity performed better under steam atmosphere than under CO2 atmosphere. Copyright © 2011 Elsevier Ltd. All rights reserved.

  15. Friedel's salt profiles from thermogravimetric analysis and thermodynamic modelling of Portland cement-based mortars exposed to sodium chloride solution

    DEFF Research Database (Denmark)

    Shi, Zhenguo; Geiker, Mette Rica; Lothenbach, Barbara

    2017-01-01

    Thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and thermodynamic modelling have been used to obtain Friedel's salt profiles for saturated mortar cylinders exposed to a 2.8 M NaCl solution. Comparison of the measured Friedel's salt profiles with the total chloride profiles...

  16. Determination of nanoparticle surface coatings and nanoparticle purity using microscale thermogravimetric analysis.

    Science.gov (United States)

    Mansfield, Elisabeth; Tyner, Katherine M; Poling, Christopher M; Blacklock, Jenifer L

    2014-02-04

    The use of nanoparticles in some applications (i.e., nanomedical, nanofiltration, or nanoelectronic) requires small samples with well-known purities and composition. In addition, when nanoparticles are introduced into complex environments (e.g., biological fluids), the particles may become coated with matter, such as proteins or lipid layers. Many of today's analytical techniques are not able to address small-scale samples of nanoparticles to determine purity and the presence of surface coatings. Through the use of an elevated-temperature quartz crystal microbalance (QCM) method we call microscale thermogravimetric analysis, or μ-TGA, the nanoparticle purity, as well as the presence of any surface coatings of nanomaterials, can be measured. Microscale thermogravimetric analysis is used to determine the presence and amount of surface-bound ligand coverage on gold nanoparticles and confirm the presence of a poly(ethylene glycol) coating on SiO2 nanoparticles. Results are compared to traditional analytical techniques to demonstrate reproducibility and validity of μ-TGA for determining the presence of nanoparticle surface coatings. Carbon nanotube samples are also analyzed and compared to conventional TGA. The results demonstrate μ-TGA is a valid method for quantitative determination of the coatings on nanoparticles, and in some cases, can provide purity and compositional data of the nanoparticles themselves.

  17. Isothermal thermogravimetric data acquisition analysis system

    Science.gov (United States)

    Cooper, Kenneth, Jr.

    1991-01-01

    The description of an Isothermal Thermogravimetric Analysis (TGA) Data Acquisition System is presented. The system consists of software and hardware to perform a wide variety of TGA experiments. The software is written in ANSI C using Borland's Turbo C++. The hardware consists of a 486/25 MHz machine with a Capital Equipment Corp. IEEE488 interface card. The interface is to a Hewlett Packard 3497A data acquisition system using two analog input cards and a digital actuator card. The system provides for 16 TGA rigs with weight and temperature measurements from each rig. Data collection is conducted in three phases. Acquisition is done at a rapid rate during initial startup, at a slower rate during extended data collection periods, and finally at a fast rate during shutdown. Parameters controlling the rate and duration of each phase are user programmable. Furnace control (raising and lowering) is also programmable. Provision is made for automatic restart in the event of power failure or other abnormal terminations. Initial trial runs were conducted to show system stability.

  18. Cerebral blood flow SPET in transient global amnesia with automated ROI analysis by 3DSRT

    Energy Technology Data Exchange (ETDEWEB)

    Takeuchi, Ryo [Division of Nuclear Medicine, Nishi-Kobe Medical Center, Kohjidai 5-7-1, 651-2273, Nishi-ku, Kobe-City, Hyogo (Japan); Matsuda, Hiroshi [Department of Radiology, National Center Hospital for Mental, Nervous and Muscular Disorders, National Center of Neurology and Psychiatry, Tokyo (Japan); Yoshioka, Katsunori [Daiichi Radioisotope Laboratories, Ltd., Tokyo (Japan); Yonekura, Yoshiharu [Biomedical Imaging Research Center, University of Fukui, Fukui (Japan)

    2004-04-01

    The aim of this study was to determine the areas involved in episodes of transient global amnesia (TGA) by calculation of cerebral blood flow (CBF) using 3DSRT, fully automated ROI analysis software which we recently developed. Technetium-99m l,l-ethyl cysteinate dimer single-photon emission tomography ({sup 99m}Tc-ECD SPET) was performed during and after TGA attacks on eight patients (four men and four women; mean study interval, 34 days). The SPET images were anatomically standardized using SPM99 followed by quantification of 318 constant ROIs, grouped into 12 segments (callosomarginal, precentral, central, parietal, angular, temporal, posterior cerebral, pericallosal, lenticular nucleus, thalamus, hippocampus and cerebellum), in each hemisphere to calculate segmental CBF (sCBF) as the area-weighted mean value for each of the respective 12 segments based on the regional CBF in each ROI. Correlation of the intra- and post-episodic sCBF of each of the 12 segments of the eight patients was estimated by scatter-plot graphical analysis and Pearson's correlation test with Fisher's Z-transformation. For the control, {sup 99m}Tc-ECD SPET was performed on eight subjects (three men and five women) and repeated within 1 month; the correlation between the first and second sCBF values of each of the 12 segments was evaluated in the same way as for patients with TGA. Excellent reproducibility between the two sCBF values was found in all 12 segments of the control subjects. However, a significant correlation between intra- and post-episodic sCBF was not shown in the thalamus or angular segments of TGA patients. The present study was preliminary, but at least suggested that thalamus and angular regions are closely involved in the symptoms of TGA. (orig.)

  19. Cerebral blood flow SPET in transient global amnesia with automated ROI analysis by 3DSRT

    International Nuclear Information System (INIS)

    Takeuchi, Ryo; Matsuda, Hiroshi; Yoshioka, Katsunori; Yonekura, Yoshiharu

    2004-01-01

    The aim of this study was to determine the areas involved in episodes of transient global amnesia (TGA) by calculation of cerebral blood flow (CBF) using 3DSRT, fully automated ROI analysis software which we recently developed. Technetium-99m l,l-ethyl cysteinate dimer single-photon emission tomography ( 99m Tc-ECD SPET) was performed during and after TGA attacks on eight patients (four men and four women; mean study interval, 34 days). The SPET images were anatomically standardized using SPM99 followed by quantification of 318 constant ROIs, grouped into 12 segments (callosomarginal, precentral, central, parietal, angular, temporal, posterior cerebral, pericallosal, lenticular nucleus, thalamus, hippocampus and cerebellum), in each hemisphere to calculate segmental CBF (sCBF) as the area-weighted mean value for each of the respective 12 segments based on the regional CBF in each ROI. Correlation of the intra- and post-episodic sCBF of each of the 12 segments of the eight patients was estimated by scatter-plot graphical analysis and Pearson's correlation test with Fisher's Z-transformation. For the control, 99m Tc-ECD SPET was performed on eight subjects (three men and five women) and repeated within 1 month; the correlation between the first and second sCBF values of each of the 12 segments was evaluated in the same way as for patients with TGA. Excellent reproducibility between the two sCBF values was found in all 12 segments of the control subjects. However, a significant correlation between intra- and post-episodic sCBF was not shown in the thalamus or angular segments of TGA patients. The present study was preliminary, but at least suggested that thalamus and angular regions are closely involved in the symptoms of TGA. (orig.)

  20. Time-dependent bridging and life prediction of SiC/SiC in a hypothetical fusion environment

    International Nuclear Information System (INIS)

    Henager, C.H. Jr.; Lewinsohn, C.A.; Windisch, C.F. Jr.; Jones, R.H.

    1996-01-01

    Growth of subcritical cracks in SiC/SiC composites of CG-Nicalon fibers with a ∼1 μm C-interphase has been measured on a related Basic Energy Sciences program using environments of purified argon and mixtures of argon and oxygen at 1073K to 1373K. Companion thermo-gravimetric (TGA) testing measured mass loss in identical environments. The TGA mass loss was from C-interphase oxidation to CO and CO 2 , which was undetectable in argon and linear with oxygen concentration in argon-oxygen mixtures, and was converted into an interphase linear recession rate. Crack growth in pure argon indicated that fiber creep was causing time-dependent crack bridging to occur, while crack growth in argon-oxygen mixtures indicated that time-dependent C-interphase recession was also causing time-dependent bridging with different kinetics. A model of time-dependent bridging was used to compute crack growth rates in argon and in argon-oxygen mixtures and gave an estimate of useable life of about 230 days at 1073K in a He + 1.01 Pa O 2 (10 ppm) environment

  1. Time-dependent bridging and life prediction of SiC/SiC in a hypothetical fusion environment

    Energy Technology Data Exchange (ETDEWEB)

    Henager, C.H. Jr.; Lewinsohn, C.A.; Windisch, C.F. Jr.; Jones, R.H. [Pacific Northwest National Lab., Richland, WA (United States)

    1996-10-01

    Growth of subcritical cracks in SiC/SiC composites of CG-Nicalon fibers with a {approximately}1 {mu}m C-interphase has been measured on a related Basic Energy Sciences program using environments of purified argon and mixtures of argon and oxygen at 1073K to 1373K. Companion thermo-gravimetric (TGA) testing measured mass loss in identical environments. The TGA mass loss was from C-interphase oxidation to CO and CO{sub 2}, which was undetectable in argon and linear with oxygen concentration in argon-oxygen mixtures, and was converted into an interphase linear recession rate. Crack growth in pure argon indicated that fiber creep was causing time-dependent crack bridging to occur, while crack growth in argon-oxygen mixtures indicated that time-dependent C-interphase recession was also causing time-dependent bridging with different kinetics. A model of time-dependent bridging was used to compute crack growth rates in argon and in argon-oxygen mixtures and gave an estimate of useable life of about 230 days at 1073K in a He + 1.01 Pa O{sub 2} (10 ppm) environment.

  2. Sorption-enhanced steam methane reforming in fluidized bed reactors

    Energy Technology Data Exchange (ETDEWEB)

    Johnsen, Kim

    2006-10-15

    reformer-calciner system is likely to be rather low, so that only a fraction of the sorbent is utilized, highlighting the importance of the carbonation model at lower conversions. A dual fluidized bed reactor for the SE-SMR system was modeled by using a simple two-phase hydrodynamic model, the experimentally derived carbonation kinetics and literature values for the kinetics of steam reforming and water gas shift reactions. The model delineates important features of the process. Hydrogen concentrations of >98 mole% were predicted for temperatures {approx}600 C and a superficial gas velocity of 0.1 m/s. The reformer temperature should not be lower than 540 C or greater than 630 C for carbon capture efficiencies to exceed 90%. Operating at relatively high solid circulation rates to reduce the need for fresh sorbent, is predicted to give higher system efficiencies than for the case where fresh solid is added. This finding is attributed to the additional energy required to decompose both CaCO{sub 3} and MgCO{sub 3} in fresh dolomite. Moreover, adding fresh sorbent is likely to result in catalyst loss in the purge stream, requiring sorbents with lifetimes comparable to those of the catalyst. Thermo gravimetric analysis (TGA) was used to study the reversible CO{sub 2}-uptake of sorbents. In general, the multi-cycle capacity of the dolomite was found rather poor. Therefore, synthetic sorbents that maintain their capacities upon multiple reforming-calcination cycles were investigated. A low-temperature liquid phase co-precipitation method was used for synthesis of Li{sub 2}ZrO{sub 3} and Na{sub 2}ZrO{sub 3}. Li{sub 2}ZrO{sub 3} showed a superior multi-cycle capacity compared to Arctic dolomite in TGA, but the rate of reaction in diluted CO{sub 2} atmospheres was very slow. The synthesized Na{sub 2}ZrO{sub 3} proved to have both fast carbonation kinetics and stable multi-cycle performance. However, regeneration in the presence of carbon dioxide was not easily accomplished. The

  3. Similarity Analysis of Cable Insulations by Chemical Test

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Seog [Central Research Institute of Korea Hydro and Nuclear Power Co., Daejeon (Korea, Republic of)

    2013-10-15

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials.

  4. Similarity Analysis of Cable Insulations by Chemical Test

    International Nuclear Information System (INIS)

    Kim, Jong Seog

    2013-01-01

    As result of this experiment, it was found that FT-IR test for material composition, TGA test for aging trend are applicable for similarity analysis of cable materials. OIT is recommended as option if TGA doesn't show good trend. Qualification of new insulation by EQ report of old insulation should be based on higher activation energy of new insulation than that of old one in the consideration of conservatism. In old nuclear power plant, it is easy to find black cable which has no marking of cable information such as manufacturer, material name and voltage. If a type test is required for qualification of these cables, how could I select representative cable? How could I determine the similarity of these cables? If manufacturer has qualified a cable for nuclear power plant more than a decade ago and composition of cable material is changed with similar one, is it acceptable to use the old EQ report for recently manufactured cable? It is well known to use FT-IR method to determine the similarity of cable materials. Infrared ray is easy tool to compare compositions of each material. But, it is not proper to compare aging trend of these materials. Study for similarity analysis of cable insulation by chemical test is described herein. To study a similarity evaluation method for polymer materials, FT-IR, TGA and OIT tests were performed for two cable insulation(old and new) which were supplied from same manufacturer. FT-IR shows good result to compare material compositions while TGA and OIT show good result to compare aging character of materials

  5. Thermal analysis and its application in evaluation of fluorinated polyimide membranes for gas separation

    KAUST Repository

    Qiu, Wulin

    2011-08-01

    Seven polyimides based on (4,4′-hexafluoroisopropylidene) diphthalic anhydride, 6FDA, with different chemical structures were synthesized in a single pot two-step procedure by first producing a high molecular weight polyamic acid (PAA), followed by reaction with acetic anhydride to produce polyimide (PI). The resulting polymers were characterized using thermal analysis techniques including TGA, derivative weight analysis, TGA-MS, and DSC. The decarboxylation-induced thermal cross-linking, ester cross-linking through a diol, and ion-exchange reactions of selected polyimide membranes were investigated. Cross-linking of polymer membranes was confirmed by solubility tests and CO 2 permeability measurements. The thermal analysis provides simple and timesaving opportunities to characterize the polymer properties, the ability to optimize polymer cross-linking conditions, and to monitor polymer functionalization to develop high performance polymeric membranes for gas separations. © 2011 Elsevier Ltd. All rights reserved.

  6. Synthesis and Characterization of Some New Thermal Stable Polymers - Polymerization of N-[4-N´ -(Benzylamino-carbonylphenyl]maleimide

    Directory of Open Access Journals (Sweden)

    B. L. Hiran

    2007-01-01

    Full Text Available This article describes the synthesis and characterization of homopolymer (H-BCPM of N-[4-N'-(benzylamino-carbonyl phenyl] maleimide (N-BACPMI and copolymer (C-BCPM of N-BACPMI with n-butyl acrylate (BA. The new monomer was synthesized from p-aminobenzoic acid, maleic anhydride and benzylamine. The homopolymerization of N-BACPMI is initiated by free radical using AIBN in THF solvent at 65°C. Radical copolymerization of N-BACPMI with BA, initiated by AIBN, was performed in THF solvent using equimolar amount. Effect of the different free radical initiator AIBN, BPO and solvents p-Dioxane, THF, DMF and DMSO was studied. Homopolymer and Copolymer were characterized by intrinsic viscosity, solubility test, FT-IR, 1H-NMR spectral analysis and elemental analysis. Thermal behaviour was studied by Thermo gravimetric analysis.

  7. Assessment of a synchrotron X-ray method for quantitative analysis of calcium hydroxide

    International Nuclear Information System (INIS)

    Williams, P. Jason; Biernacki, Joseph J.; Bai Jianming; Rawn, Claudia J.

    2003-01-01

    Thermogravimetric analysis (TGA) and quantitative X-ray diffraction (QXRD) are widely used to determine the calcium hydroxide (CH) content in cementitious systems containing blends of Portland cement, fly ash, blast furnace slag, silica fume and other pozzolanic and hydraulic materials. These techniques, however, are destructive to cement samples and subject to various forms of error. While precise weight losses can be measured by TGA, extracting information from samples with multiple overlapping thermal events is difficult. And, however, while QXRD can offer easier deconvolution, the accuracy for components below about 5 wt.% is typically poor when a laboratory X-ray source is used. Furthermore, the destructive nature of both techniques prevents using them to study the in situ hydration of a single contiguous sample for kinetic analysis. In an attempt to overcome these problems, the present research evaluated the use of synchrotron X-rays for quantitative analysis of CH. A synchrotron X-ray source was used to develop calibration data for quantification of the amount of CH in mixtures with fly ash. These data were compared to conventional laboratory XRD data for like samples. While both methods were found to offer good quantification, synchrotron XRD (SXRD) provided a broader range of detectability and higher accuracy than laboratory diffraction and removed the subjectivity as compared to TGA analysis. Further, the sealed glass capillaries used with the synchrotron source provided a nondestructive closed, in situ environment for tracking hydrating specimens from zero to any desired age

  8. Characterization and thermogravimetric analysis of lanthanide hexafluoroacetylacetone chelates.

    Science.gov (United States)

    Shahbazi, Shayan; Stratz, S Adam; Auxier, John D; Hanson, Daniel E; Marsh, Matthew L; Hall, Howard L

    2017-01-01

    This work reports the thermodynamic characterizations of organometallic species as a vehicle for the rapid separation of volatile nuclear fission products via gas chromatography due to differences in adsorption enthalpy. Because adsorption and sublimation thermodynamics are linearly correlated, there is considerable motivation to determine sublimation enthalpies. A method of isothermal thermogravimetric analysis, TGA-MS and melting point analysis are employed on thirteen lanthanide 1,1,1,5,5,5-hexafluoroacetylacetone complexes to determine sublimation enthalpies. An empirical correlation is used to estimate adsorption enthalpies of lanthanide complexes on a quartz column from the sublimation data. Additionally, four chelates are characterized by SC-XRD, elemental analysis, FTIR and NMR.

  9. Investigation of Water Absorption and Diffusion in Microparticles Containing Xylitol to Provide a Cooling Effect by Thermal Analysis

    Science.gov (United States)

    Salaün, F.; Bedek, G.; Devaux, E.; Dupont, D.; Deranton, D.

    2009-08-01

    Polyurethane microparticles containing xylitol as a sweat sensor system were prepared by interfacial polymerization. The structural and thermal properties of the resultant microparticles were studied. The surface morphology and chemical structure of microparticles were investigated using an optical microscope (OM) and a Fourier-transform infrared spectroscope (FTIR), respectively. The thermal properties of samples were investigated by thermogravimetric analysis (TGA) and by differential scanning calorimetry (DSC). Thus, two types of microparticles were synthesized by varying the percentage of monomers introduced. The obtained morphology is directly related to the synthesis conditions. DSC analysis indicated that the mass content of crystalline xylitol was up to 63.8 %, which resulted in a high enthalpy of dilution of 127.7 J · g-1. Furthermore, the water release rate monitored by TGA analysis was found to be faster from the microparticles than from raw xylitol. Thus, the microparticles could be applied for thermal energy storage and moisture sensor enhancement.

  10. Kinetic parameters from thermogravimetric analysis

    Science.gov (United States)

    Kiefer, Richard L.

    1993-01-01

    High performance polymeric materials are finding increased use in aerospace applications. Proposed high speed aircraft will require materials to withstand high temperatures in an oxidative atmosphere for long periods of time. It is essential that accurate estimates be made of the performance of these materials at the given conditions of temperature and time. Temperatures of 350 F (177 C) and times of 60,000 to 100,000 hours are anticipated. In order to survey a large number of high performance polymeric materials on a reasonable time scale, some form of accelerated testing must be performed. A knowledge of the rate of a process can be used to predict the lifetime of that process. Thermogravimetric analysis (TGA) has frequently been used to determine kinetic information for degradation reactions in polymeric materials. Flynn and Wall studied a number of methods for using TGA experiments to determine kinetic information in polymer reactions. Kinetic parameters, such as the apparent activation energy and the frequency factor, can be determined in such experiments. Recently, researchers at the McDonnell Douglas Research Laboratory suggested that a graph of the logarithm of the frequency factor against the apparent activation energy can be used to predict long-term thermo-oxidative stability for polymeric materials. Such a graph has been called a kinetic map. In this study, thermogravimetric analyses were performed in air to study the thermo-oxidative degradation of several high performance polymers and to plot their kinetic parameters on a kinetic map.

  11. Enhancement of Thermal Stability and Selectivity by Introducing Aminotriazine Comonomer to Poly(Octadecyl Acrylate-Grafted Silica as Chromatography Matrix

    Directory of Open Access Journals (Sweden)

    Abul K. Mallik

    2018-02-01

    Full Text Available This paper introduces a poly(octadecyl acrylate (pODA-based organic phase on silica, which is assisted by 2-vinyl-4,6-diamino-1,3,5-triazine (AT, for a chromatography stationary phase. The ODA-AT copolymer grafting onto silica surface was characterized by elemental analysis, FT-IR spectroscopy, scanning electron microscopy, thermo gravimetric analysis and differential scanning calorimeter (DSC. An endothermic peak top of the copolymer-grafted silica was increased to 46 °C from 38 °C, which was a peak top of pODA homopolymer. For high performance liquid chromatography (HPLC application, the molecular selectivity increased with an increase in the AT contents of the ODA-AT copolymer as organic phase. The co-existence of an aminotriazine moiety in the copolymer promoted side-chain ordering of the poly(octadecyl moiety, thus enhancing molecular planarity selectivity for PAHs in reversed-phase liquid chromatography.

  12. Effects of aging on the structural, mechanical, and thermal properties of the silicone rubber current transformer insulation bushing for a 500 kV substation.

    Science.gov (United States)

    Wang, Zhigao; Zhang, Xinghai; Wang, Fangqiang; Lan, Xinsheng; Zhou, Yiqian

    2016-01-01

    In order to analyze the cracking and aging reason of the silicone rubber current transformer (CT) insulation bushing used for 8 years from a 500 kV alternating current substation, characteristics including Fourier transform infrared (FTIR) spectroscopy, mechanical properties analysis, hardness, and thermo gravimetric analysis have been carried out. The FTIR results indicated that the external surface of the silicone rubber CT insulation bushing suffered from more serious aging than the internal part, fracture of side chain Si-C bond was much more than the backbone. Mechanical properties and thermal stability results illustrated that the main aging reasons were the breakage of side chain Si-C bond and the excessive cross-linking reaction of the backbone. This study can provide valuable basis for evaluating degradation mechanism and aging state of the silicone rubber insulation bushing in electric power field.

  13. Fabrication of cavities in low loss LTCC materials for microwave applications

    International Nuclear Information System (INIS)

    Malecha, Karol

    2012-01-01

    A method of buried cavity fabrication in low loss DP951 and new DP9K7 LTCC (low-temperature co-fired ceramic) materials is described in this paper. Laser micromachining and method based on sacrificial volume material (SVM) are studied. Cavities are fabricated in LTCC materials using two different SVMs—cetyl alcohol and carbon tape. The influence of laser system parameters on cutting quality of the LTCC materials is studied. Moreover, thermal properties of the LTCCs and used SVMs are analyzed using combined thermo-gravimetric analysis, differential thermal analysis and differential thermo-gravimetry. Geometries of the LTCC test structures fabricated using different SVMs are analyzed using a scanning electron microscope and x-ray tomography. Energy dispersive spectroscopy and surface wettability measurements are used to analyze changes in LTCC materials atomic composition after co-firing with SVMs. (paper)

  14. Synthesis of imine bond containing insoluble polymeric ligand and its transition metal complexes, structural characterization and catalytic activity on esterification reaction.

    Science.gov (United States)

    Gönül, İlyas; Ay, Burak; Karaca, Serkan; Saribiyik, Oguz Yunus; Yildiz, Emel; Serin, Selahattin

    2017-01-01

    In this study, synthesis of insoluble polymeric ligand (L) and its transition metal complexes [Cu(L)Cl 2 ]·2H 2 O (1) , [Co(L)Cl 2 (H 2 O) 2 ] (2) and [Ni(L)Cl 2 (H 2 O) 2 ] (3) , having the azomethine groups, were synthesized by the condensation reactions of the diamines and dialdehydes. The structural properties were characterized by the analytical and spectroscopic methods using by elemental analysis, Fourier Transform Infrared, Thermo Gravimetric Analysis, Powder X-ray Diffraction, magnetic susceptibility and Inductively Coupled Plasma. The solubilities of the synthesized polymeric materials were also investigated and found as insoluble some organic and inorganic solvents. Additionally, their catalytic performance was carried out for the esterification reaction of acetic acid and butyl acetate. The highest conversion rate is 75.75% by using catalyst 1 . The esterification of butanol gave butyl acetate with 100% selectivity.

  15. Electrophoretic deposition and electrochemical behavior of novel graphene oxide-hyaluronic acid-hydroxyapatite nanocomposite coatings

    International Nuclear Information System (INIS)

    Li, Ming; Liu, Qian; Jia, Zhaojun; Xu, Xuchen; Shi, Yuying; Cheng, Yan; Zheng, Yufeng; Xi, Tingfei; Wei, Shicheng

    2013-01-01

    Novel ternary graphene oxide-hyaluronic acid-hydroxyapatite (GO-HY-HA) nanocomposite coatings were prepared on Ti substrate using anodic electrophoretic deposition (EPD). Hyaluronic acid was employed as charging additive and dispersion agent during EPD. The kinetics and mechanism of the deposition, and the microstructure of the coated samples were investigated using scanning electron microscopy, X-ray diffraction, Raman spectrum, thermo-gravimetric analysis, and microscopic Fourier transform infrared analysis. The results showed that the addition of GO sheets into the HY-HA suspensions could increase the deposition rate and inhibit cracks creation and propagation in the coatings. The corrosion resistant of the resulting samples were evaluated using potentiodynamic polarization method in simulated body fluid, and the GO-HY-HA coatings could effectively improve the anti-corrosion property of the Ti substrate

  16. Electrophoretic deposition and electrochemical behavior of novel graphene oxide-hyaluronic acid-hydroxyapatite nanocomposite coatings

    Science.gov (United States)

    Li, Ming; Liu, Qian; Jia, Zhaojun; Xu, Xuchen; Shi, Yuying; Cheng, Yan; Zheng, Yufeng; Xi, Tingfei; Wei, Shicheng

    2013-11-01

    Novel ternary graphene oxide-hyaluronic acid-hydroxyapatite (GO-HY-HA) nanocomposite coatings were prepared on Ti substrate using anodic electrophoretic deposition (EPD). Hyaluronic acid was employed as charging additive and dispersion agent during EPD. The kinetics and mechanism of the deposition, and the microstructure of the coated samples were investigated using scanning electron microscopy, X-ray diffraction, Raman spectrum, thermo-gravimetric analysis, and microscopic Fourier transform infrared analysis. The results showed that the addition of GO sheets into the HY-HA suspensions could increase the deposition rate and inhibit cracks creation and propagation in the coatings. The corrosion resistant of the resulting samples were evaluated using potentiodynamic polarization method in simulated body fluid, and the GO-HY-HA coatings could effectively improve the anti-corrosion property of the Ti substrate.

  17. Mathematical Modeling of Conversion Kinetics during Vitrification of Nuclear Waste

    International Nuclear Information System (INIS)

    Pokorny, Richard; Pierce, David A.; Chun, Jae Hun; Hrma, Pavel

    2012-01-01

    The last part of the high-level waste (HLW) glass melter that has not yet been fully understood, not to mention mathematically modeled, is the cold cap. Cold cap is a layer of dry melter feed, a mixture of the HLW with glass forming and modifying additives. It floats on the pool of molten glass from which it receives the heat necessary for melting. Mathematical modeling of the cold cap solves differential equations that express the mass and energy balances for the feed-to-glass conversion within the cold cap. The feed-to-glass conversion consists of multiple chemical reactions and phase transitions. Reaction enthalpies and mass losses to gases evolved provide an important input for the cold cap modeling. In this study, we measured the kinetics of cold cap reactions using the non-isothermal thermo-gravimetric analysis (TGA) and differential scanning calorimetry (DSC). These thermoanalytical techniques show multiple overlapping peaks, necessitating the development of a deconvolution method for the determination of the kinetics of major reactions needed for cold cap modeling. Assuming that the cold cap reactions are independent, we expressed the overall rate as a sum of rates of individual reactions that we treat as Arrheniustype processes with a power-law based kinetics. Accordingly, we fitted to experimental data the following equation: dx/dT=1/Φ N Σ 1 w i A i (1-x i ) ni exp(-B i /T) (1) where x is the fraction of material reacted, T is temperature, Φ is the heating rate, wi the weight of the i th reaction (the fraction of the total mass loss caused by the i th reaction), Ai is the i th reaction pre-exponential factor, B i is the i th reaction activation energy, and n i is the i th reaction (apparent) reaction order. Because HLW melter feeds contain a large number of constituents, such as oxides, acids, hydroxides, oxyhydrates, and ionic salts, the number of cold cap reactions is very large indeed. For example, hydroxides, oxyhydrates, boric acid, and various

  18. Thumba (Citrullus colocynthis L. seed oil: a potential bio-lubricant base-stock

    Directory of Open Access Journals (Sweden)

    Kamalakar, K.

    2015-03-01

    Full Text Available Thumba seed oil, a minor, renewable tree borne oil, was exploited for the preparation of biolubricant base-stocks. The different base-stocks prepared were epoxy thumba oil (ETO, branched, 2-ethylhexyl ester (T2-EtHE, and polyol esters, namely, neopentyl glycol (TNPGE, trimethylolpropane (TTMPE and pentaerythritol (TPEE esters of thumba fatty acids. All the base-stocks were thoroughly characterized using spectral techniques. When evaluated for lubricant properties, ETO showed much higher viscosity (216.9 cSt, good oxidative stability (RBOT Method, ASTM D 2272 (20 min and weld load (ASTM IP 239 (180 kg behavior when compared to the branched and polyol esters. Polyol esters, T2-EtHE, TNPGE and TTMPE (−9 to −18 °C showed low pour points compared to ETO and TPEE. The thermal stabilities (Thermo gravimetric analysis, TGA of ETO and TPEE (425 °C were higher compared to other base-stocks. The lubricant properties of ETO matched well with ISO VG 220 and Aviation Grade 100 lubricant specifications, while polyol esters can be well exploited for hydraulic and metal working fluid applications.Las semillas de thumba producen un aceite de escasa importancia que ha sido explotado como base para la preparación de biolubricantes. Los diferentes derivados de thumba preparados fueron: éteres epoxi (ETO, éteres ramificados, éster de 2-etilhexilo (T2-ETHE, y los ésteres de poliol:, neopentil glicol (TNPGE, trimetilolpropano (TTMPE y pentaeritritol (TPEE. Todas las bases se caracterizaron en su totalidad utilizando técnicas espectrales. Cuando se evaluaron las propiedades del lubricante, ETO mostró una viscosidad mucho más alta (216,9 cSt, buena estabilidad a la oxidación (RBOT Método, ASTM D 2272 (20 min y buena carga (239 ASTM IP (180 kg en comparación con el comportamiento de los ésteres de poliol y los ramificados. Los ésteres de poliol, T2-EEl, TNPGE y TTMPE (−9 a −18 °C mostraron bajos puntos de fluidez en comparación con ETO y TPE. Las

  19. Degradation of polylactic acid (Pla) at different doses of gamma radiation

    International Nuclear Information System (INIS)

    Castillo R, Y.

    2015-01-01

    The excessive use of polymers such as polyethylene (PET), polystyrene (Ps) and recently the polylactic acid (Pla) that take more than 20 years to degrade, have caused great pollution in the environment. In this study the effects of gamma radiation in the Pla to different doses were studied, in order to reduce the degradation time of this polymer. The changes in physico-chemical structure of Pla during radiation were studied by thermo-gravimetric/Mass analysis; differential scanning calorimetry; scanning electron microscopy; X-ray dispersive analysis; infrared spectroscopy; X-ray diffraction and mechanical tests of hardness, elasticity and deformation. With scanning electron microscopy, the morphology of the Pla surface unirradiated was observed, in which an apparently smooth surface was observed, after changes that had the Pla when irradiated also was observed, where the effects of radiation were observed in form of scratch, agglomeration and small fractures. By X-ray dispersive analysis was determined and verified the elemental chemical composition of the Pla; as expected the tests showed only carbon, oxygen and hydrogen. With thermo-gravimetric/Mass analysis the decomposition temperatures of Pla were determined, identifying that the degradation compounds are CO, CO 2 and CH 4 . With infrared spectrometry the major peaks of Pla were observed before and after being irradiated with increasing of radiation dose the intensity of the bands decreased. Also by X-ray diffraction was observed that the polymer is an amorphous material. The mechanical tests indicate that the values of each of the tests decrease significantly with increasing the radiation dose. (Author)

  20. Degradation of polylactic acid (Pla) at different doses of gamma radiation; Degradacion del acido polilactico (PLA) a diferentes dosis de radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Castillo R, Y.

    2015-07-01

    The excessive use of polymers such as polyethylene (PET), polystyrene (Ps) and recently the polylactic acid (Pla) that take more than 20 years to degrade, have caused great pollution in the environment. In this study the effects of gamma radiation in the Pla to different doses were studied, in order to reduce the degradation time of this polymer. The changes in physico-chemical structure of Pla during radiation were studied by thermo-gravimetric/Mass analysis; differential scanning calorimetry; scanning electron microscopy; X-ray dispersive analysis; infrared spectroscopy; X-ray diffraction and mechanical tests of hardness, elasticity and deformation. With scanning electron microscopy, the morphology of the Pla surface unirradiated was observed, in which an apparently smooth surface was observed, after changes that had the Pla when irradiated also was observed, where the effects of radiation were observed in form of scratch, agglomeration and small fractures. By X-ray dispersive analysis was determined and verified the elemental chemical composition of the Pla; as expected the tests showed only carbon, oxygen and hydrogen. With thermo-gravimetric/Mass analysis the decomposition temperatures of Pla were determined, identifying that the degradation compounds are CO, CO{sub 2} and CH{sub 4}. With infrared spectrometry the major peaks of Pla were observed before and after being irradiated with increasing of radiation dose the intensity of the bands decreased. Also by X-ray diffraction was observed that the polymer is an amorphous material. The mechanical tests indicate that the values of each of the tests decrease significantly with increasing the radiation dose. (Author)

  1. Combustion characteristics and kinetic analysis of pulverized coal under different pressure grades

    Directory of Open Access Journals (Sweden)

    Qiwei ZUO

    2016-02-01

    Full Text Available By using thermo gravimetric balance, experimental research on combustion characteristics and dynamics parameters of the typical coal injection from some domestic steelworks are conducted with non-isothermal method. The combustion characteristic parameters of the sample pulverized coal such as ignition temperature, peak temperature at maximum weight loss rate, burnout temperature, general burn exponent(S, and maximum combustion rate are studied under pressure grades of 0.1, 1.1, 2.1, 3.1 and 4.1 MPa, the activation energy (E and pre-exponential factor in the combustion process are calculated. The results show that when the pressure increases from 0.1 to 4.1 MPa, ignition temperature decreases by 85.7 K at most, peak temperature at maximum weight loss rate decreases by 249.3 K at most, burnout temperature decreases by 375 K at most, maximum weight loss rate increases by 10 times, and S increases by 33.6 times at most. It is also shown that there exists a kinetic complementation between E and ln A from the view point of dynamics, and the critical pressure of pulverized coal reaction control requirement and combustion mode transform is 3.1 MPa for the pulverized coal.

  2. Controlling the release of active compounds from the inorganic carrier halloysite

    International Nuclear Information System (INIS)

    Tescione, F.; Buonocore, G. G.; Stanzione, M.; Oliviero, M.; Lavorgna, M.

    2014-01-01

    Halloysite (HNTs), a natural material characterized by a nanotube structure, has been used as an inorganic carrier of active compounds in several applications from medicine to anticorrosion coatings. In this present work, vanillin (VAN) used as a antimicrobial model, has been encapsulated within HNTs for exploiting its applicability in the active food packaging sector. The molecule release rate has been controlled by crosslinking at the tube ends the loaded vanillin with copper ions, thus producing a stopper network. The vanillin-loaded HNTs were characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis. The antimicrobial release kinetics from the loaded nanoparticles (VAN/HNTs) in water was investigated using UV-vis spectroscopy. The results show that the vanillin crosslinked with cupper ions is a feasible method to tailor the release rate of antimicrobial model from HTNs nanoparticles

  3. Comprehensive spectral and instrumental approaches for the easy monitoring of features and purity of different carbon nanostructures for nanocomposite applications

    International Nuclear Information System (INIS)

    Boccaleri, Enrico; Arrais, Aldo; Frache, Alberto; Gianelli, Walter; Fino, Paolo; Camino, Giovanni

    2006-01-01

    A wide series of carbon nanostructures (ranging from fullerenes, through carbon nanotubes, up to carbon nanofibers) promise to change several fields in material science, but a real industrial implementation depends on their availability at reasonable prices with affordable and reproducible degrees of purity. In this study we propose simple instrumental approaches to efficiently characterize different commercial samples, particularly for qualitative evaluation of impurities, the discrimination of their respective spectral features and, when possible, for quantitative determination. We critically discuss information that researchers in the field of nanocomposite technology can achieve in this aim by spectral techniques such as Raman and FT-IR spectroscopy, thermo-gravimetrical analysis, mass spectrometry-hyphenated thermogravimetry, X-ray diffraction and energy dispersive spectroscopy. All these can be helpful, in applied research on material science, for a fast reliable monitoring of the actual purity of carbon products in both commercial and laboratory-produced samples as well as in composite materials

  4. Kinetics and compensation effects during steam gasification of Fujian anthracite using viscose liquor as catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Lin Ju; Zhang Ji-yu; Zhong Xue-qing [Fuzhou University, Fuzhou (China). Institute of Chemical Engineering and Technology

    2009-08-15

    Catalytic steam gasification kinetics of Fujian Youxi anthracite using viscose liquor as catalyst was investigated in an isothermal thermo-gravimetric analyzer under ambient pressure. Coal conversions versus reaction time with different viscose liquor concentrations (0-12% NaOH) were measured at the temperature range from 850 to 950{sup o}C. The research shows that the viscose liquor can greatly improve the gasification rate and carbon conversion. The Loading Saturation Level (LSL) of the viscose liquor within the experimental conditions was also determined. The catalytic steam gasification reaction can be well fitted by a shrinking-core model (SCM) and the reaction rate constants are obtained. The kinetic analysis indicates that the catalytic gasification exhibits a prominent compensation effect between the activation energy and the pre-exponential factor. The kinetic equation including the compensation effects for the catalytic steam gasification of Fujian Youxi anthracite using viscose liquor as catalyst is presented. 23 refs., 7 figs., 3 tabs.

  5. Hydrothermal synthesis of PEDOT/rGO composite for supercapacitor applications

    Science.gov (United States)

    Ahmed, Sultan; Rafat, M.

    2018-01-01

    In this study, PEDOT/rGO composite has been successfully synthesized using hydrothermal method. Precursor solution of EDOT monomer was mixed with a predetermined solution of graphene oxide (GO). The resultant mixture was then hydrothermally treated. Surface morphology, crystal structure vibrational response and thermal stability have been studied using standard characterization techniques: field-emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy and thermo-gravimetric analysis. The observed results confirm that the required composite of PEDOT/rGO has indeed been synthesized. Electrochemical properties of the synthesized product were studied in 6 M KOH aqueous solution, using characterization techniques such as: cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic charge-discharge measurements. The results show a high value of specific capacitance (102.8 F g-1) at 10 mV s-1, indicating that the composite can be profitably used for energy storage devices.

  6. New processing route for ZrSiO{sub 4} by powder injection moulding using an eco-friendly binder system

    Energy Technology Data Exchange (ETDEWEB)

    Abajo, C.; Jimenez-Morales, A.; Torralba, J. M.

    2015-10-01

    New processing route has been developed for zircon based on powder injection moulding (PIM). Raw zircon powders, obtained from mineral sands, have been processed using a new water soluble binder system composed of PEG and CAB. Water solvent debinding stage has been studied in depth. On one hand, influence of some debinding parameters (temperature, debinding rate, additives and the use of climate chamber) has been tested. On the other hand, new binder systems were tested and compared with previous studied ones. The full PIM process has been carried out. Mixing, injection molding, solvent and thermal debinding and finally sintering, have been performed with the optimal binder system composition. Homogeneity along the process has been assessed by thermo-gravimetric analysis and by density measurements. After sintering, dimensional variation, density and fracture surface obtained after flexural strength test, have been analyzed. A competitive flexural strength has been achieved for injected zircon samples. (Author)

  7. Characteristics of fundamental combustion and NOx emission using various rank coals.

    Science.gov (United States)

    Kim, Sung Su; Kang, Youn Suk; Lee, Hyun Dong; Kim, Jae-Kwan; Hong, Sung Chang

    2011-03-01

    Eight types of coals of different rank were selected and their fundamental combustion characteristics were examined along with the conversion of volatile nitrogen (N) to nitrogen oxides (NOx)/fuel N to NOx. The activation energy, onset temperature, and burnout temperature were obtained from the differential thermogravimetry curve and Arrhenius plot, which were derived through thermo-gravimetric analysis. In addition, to derive the combustion of volatile N to NOx/fuel N to NOx, the coal sample, which was pretreated at various temperatures, was burned, and the results were compared with previously derived fundamental combustion characteristics. The authors' experimental results confirmed that coal rank was highly correlated with the combustion of volatile N to NOx/fuel N to NOx.

  8. Synthesis and characterization of hydrogen-bond acidic functionalized graphene

    Science.gov (United States)

    Yang, Liu; Han, Qiang; Pan, Yong; Cao, Shuya; Ding, Mingyu

    2014-05-01

    Hexafluoroisopropanol phenyl group functionalized materials have great potential in the application of gas-sensitive materials for nerve agent detection, due to the formation of strong hydrogen-bonding interactions between the group and the analytes. In this paper, take full advantage of ultra-large specific surface area and plenty of carbon-carbon double bonds and hexafluoroisopropanol phenyl functionalized graphene was synthesized through in situ diazonium reaction between -C=C- and p-hexafluoroisopropanol aniline. The identity of the as-synthesis material was confirmed by transmission electron microscopy, Raman spectroscopy, ultraviolet visible spectroscopy, X-ray photoelectron spectroscopy and thermo gravimetric analysis. The synthesis method is simply which retained the excellent physical properties of original graphene. In addition, the novel material can be assigned as an potential candidate for gas sensitive materials towards organophosphorus nerve agent detection.

  9. Polymer-derived Ceramic SiCN-MoS2 Nanosheet Composite for Lithium Ion Battery Anodes

    Science.gov (United States)

    Bhandavat, Romil; Singh, Gurpreet

    2012-02-01

    We demonstrate synthesis of a novel SiCN-MoS2 nanosheet composite for use as Li-ion battery anode for high power applications. The nanosheet composite was prepared by thermal decomposition of polysilazane (SiCN precursor) on exfoliated MoS2 surfaces. The morphology and chemical structure was studied using a range of spectroscopy techniques that revealed a sidewall functionalization of exfoliated MoS2 by the polymeric precursor. The thermodynamic stability of SiCN-MoS2 nanosheets was also confirmed by thermo-gravimetric analysis (1000 degree C). Batteries assembled using MoS2-SiCN nanosheets as active anode material showed that lithium can be reversibly intercalated in the voltage range of 0-2.5 V with first cycle discharge capacity of 620 mAh/g at a current density of 100 mA/g.

  10. ECAP consolidation of Al matrix composites reinforced with in-situ γ-Al{sub 2}O{sub 3} nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Casati, R., E-mail: riccardo.casati@polimi.it [Department of Mechanical Engineering, Politecnico di Milano, Via La Masa 1, Milano (Italy); Fabrizi, A. [Department of Management and Engineering, Università di Padova, Stradella S. Nicola 3, Vicenza (Italy); Tuissi, A. [CNR-IENI, Corso Promessi Sposi 29, Lecco (Italy); Xia, K. [Department of Mechanical Engineering, University of Melbourne, Victoria 3010 (Australia); Vedani, M. [Department of Mechanical Engineering, Politecnico di Milano, Via La Masa 1, Milano (Italy)

    2015-11-11

    This work is aimed at proposing a method to prepare aluminum matrix composites reinforced with γ-Al{sub 2}O{sub 3} nanoparticles and at describing the effects of an in-situ reaction on the resulting nano-reinforcement dispersed throughout the metal matrix. Al nano- and micro-particles were used as starting materials. They were consolidated by equal channel angular pressing (ECAP) in as-received conditions and after undergoing high-energy ball milling. Further, γ-Al{sub 2}O{sub 3} reinforcing nanoparticles were produced in-situ from the hydroxide layer that covered the Al powder particles. The powder particle morphology and the composites microstructures were investigated by electron microscopy. The transformation process was monitored by X-ray diffraction, differential scanning calorimetry and thermo-gravimetric analysis.

  11. Controlling the release of active compounds from the inorganic carrier halloysite

    Energy Technology Data Exchange (ETDEWEB)

    Tescione, F.; Buonocore, G. G.; Stanzione, M.; Oliviero, M.; Lavorgna, M. [National Research Council - Institute of Composites and Biomedical Materials, P.le E. Fermi, 1 80055 Portici (Naples) (Italy)

    2014-05-15

    Halloysite (HNTs), a natural material characterized by a nanotube structure, has been used as an inorganic carrier of active compounds in several applications from medicine to anticorrosion coatings. In this present work, vanillin (VAN) used as a antimicrobial model, has been encapsulated within HNTs for exploiting its applicability in the active food packaging sector. The molecule release rate has been controlled by crosslinking at the tube ends the loaded vanillin with copper ions, thus producing a stopper network. The vanillin-loaded HNTs were characterized using transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and thermo gravimetric analysis. The antimicrobial release kinetics from the loaded nanoparticles (VAN/HNTs) in water was investigated using UV-vis spectroscopy. The results show that the vanillin crosslinked with cupper ions is a feasible method to tailor the release rate of antimicrobial model from HTNs nanoparticles.

  12. Physical Characterization of Natural Straw Fibers as Aggregates for Construction Materials Applications.

    Science.gov (United States)

    Bouasker, Marwen; Belayachi, Naima; Hoxha, Dashnor; Al-Mukhtar, Muzahim

    2014-04-11

    The aim of this paper is to find out new alternative materials that respond to sustainable development criteria. For this purpose, an original utilization of straw for the design of lightweight aggregate concretes is proposed. Four types of straw were used: three wheat straws and a barley straw. In the present study, the morphology and the porosity of the different straw aggregates was studied by SEM in order to understand their effects on the capillary structure and the hygroscopic behavior. The physical properties such as sorption-desorption isotherms, water absorption coefficient, pH, electrical conductivity and thermo-gravimetric analysis were also studied. As a result, it has been found that this new vegetable material has a very low bulk density, a high water absorption capacity and an excellent hydric regulator. The introduction of the straw in the water tends to make the environment more basic; this observation can slow carbonation of the binder matrix in the presence of the straw.

  13. Synthesis of C{sub 60}(OH){sub 18-20} in aqueous alkaline solution under O{sub 2}-atmosphere

    Energy Technology Data Exchange (ETDEWEB)

    Alves, Gustavo Catao; Ladeira, Luiz Orlando; Righi, Ariete; Krambrock, Klaus; Pinheiro, Mauricio Veloso B. [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Fisica; Calado, Hallen Daniel; Gil, Rossimiriam Pereira de Freitas [Minas Gerais Univ., Belo Horizonte, MG (Brazil). Dept. de Quimica]. E-mail: gustavo.catao@terra.com.br

    2006-09-15

    In this work we report on an alternative synthesis of water-soluble fullerenes known as fullerols, aiming for biomedical applications. The synthesis is based on a process in which polyethylene glycol (PEG400) is used as phase-transfer catalyst between fullerene/benzene and aqueous NaOH solutions. The polyhydroxylation of the fullerenes occurs in the NaOH solution under a continuous flow of O{sub 2} to enhance the reaction yield. The resulting compound was characterized with infrared spectroscopy, nuclear magnetic resonance, thermo-gravimetric analysis and optical absorption. The formation of C{sub 60}(OH){sub 18-20} in high yields was confirmed. (author)

  14. Application of multi-block methods in cement production

    DEFF Research Database (Denmark)

    Svinning, K.; Høskuldsson, Agnar

    2008-01-01

    distribution and the two last blocks the superficial microstructure analysed by differential thermo gravimetric analysis. The multi-block method is used to identify the role of each part. The score vectors of each block can be analysed separately or together with score vectors of other blocks. Stepwise......Compressive strength at 1 day of Portland cement as a function of the microstructure of cement was statistically modelled by application of multi-block regression method. The observation X-matrix was partitioned into four blocks, the first block representing the mineralogy, the second particle size...... regression is used to find minimum number of variables of each block. The multi-block method proved useful in determining the modelling strength of each data block and finding minimum number of variables within each data block....

  15. Adsorption performance of CuFe2O4/rGO nanocomposites towards organic dye

    International Nuclear Information System (INIS)

    Tang, Mingyi; Li, Xichuan; Gao, Chunjuan; Li, Xianxian; Qiu, Haixia

    2017-01-01

    A facile and efficient approach was employed to synthesize CuFe 2 O 4 /rGO (reduced graphene oxide) nanocomposites. The morphology, crystal structure and properties of the prepared CuFe 2 O 4 /rGO nanocomposites were characterized by transmission electron microscopy, energy-dispersive X-ray spectroscopy, powder X-ray diffraction and thermo-gravimetric analysis. The CuFe 2 O 4 /rGO nanocomposites were applied as adsorbents to study their adsorption performance for Congo red. The adsorption capacity and recyclability, adsorption dynamics and adsorption models were investigated. The results show that the CuFe 2 O 4 /rGO nanocomposites are efficient and recyclable adsorbents. - Highlights: • CuFe 2 O 4 /rGO was synthesized by a facile hydrothermal route. • As an adsorbent it showed high adsorption capacity to CR. • It was magnetically removable and has high reusability.

  16. Synthesis, growth, structural, optical, thermal, electrical and mechanical properties of hydrogen bonded organic salt crystal: Triethylammonium-3, 5-dinitrosalicylate

    Science.gov (United States)

    Rajkumar, Madhu; Chandramohan, Angannan

    2017-04-01

    Triethylammonium-3, 5-dinitrosalicylate, an organic salt was synthesized and single crystals grown by slow solvent evaporation solution growth technique using methanol as a solvent. The presence of various functional groups and mode of vibrations has been confirmed by FT-IR spectroscopic technique. The UV-vis-NIR Spectrum was recorded in the range 200-1200 nm to find optical transmittance window and lower cut off wavelength of the title crystal. The formation of the salt and the molecular structure was confirmed by NMR spectroscopic technique. Crystal system, crystalline nature, cell parameters and hydrogen bonding interactions of the grown crystal were determined by single crystal x-ray diffraction analysis. The thermal characteristics of grown crystal were analyzed by thermo gravimetric and differential thermal analyses. Dielectric studies were carried out to study the distribution of charges within the crystal. The mechanical properties of the title crystal were studied by Vicker's microhardness technique.

  17. Properties of Roman bricks and mortars used in Serapis temple in the city of Pergamon

    International Nuclear Information System (INIS)

    Ozkaya, Ozlem Aslan; Boeke, Hasan

    2009-01-01

    Serapis temple, which was constructed in the Roman period in the city of Pergamon (Bergama/Turkey), is one of the most important monuments of the world heritage. In this study, the characteristics of bricks and mortars used in the temple have been determined in order to define the necessary characteristics of the intervention materials, which will be used in the conservation works of the temple. Several analyses were carried out to determine their basic physical properties, raw material compositions, mineralogical and microstructural properties using X-ray diffraction, Scanning Electron Microscope and a Thermo Gravimetric Analyzer. Analysis results indicated that the mortars are stiff, compact and hydraulic due to the use of natural pozzolanic aggregates. The Roman bricks are of low density, high porosity and were produced from raw materials containing calcium poor clays fired at low temperatures.

  18. Solid-state reaction kinetics and optical studies of cadmium doped magnesium hydrogen phosphate crystals

    Science.gov (United States)

    Verma, Madhu; Gupta, Rashmi; Singh, Harjinder; Bamzai, K. K.

    2018-04-01

    The growth of cadmium doped magnesium hydrogen phosphate was successfully carried out by using room temperature solution technique i.e., gel encapsulation technique. Grown crystals were confirmed by single crystal X-ray diffraction (XRD). The structure of the grown crystal belongs to orthorhombic crystal system and crystallizes in centrosymmetric space group. Kinetics of the decomposition of the grown crystals were studied by non-isothermal analysis. Thermo gravimetric / differential thermo analytical (TG/DTA) studies revealed that the grown crystal is stable upto 119 °C. The various steps involved in the thermal decomposition of the material have been analysed using Horowitz-Metzger, Coats-Redfern and Piloyan-Novikova equations for evaluating various kinetic parameters. The optical studies shows that the grown crystals possess wide transmittance in the visible region and significant optical band gap of 5.5ev with cut off wavelength of 260 nm.

  19. Synthesis of Mesoporous Nanocrystalline Zirconia by Surfactant-Assisted Hydrothermal Approach.

    Science.gov (United States)

    Nath, Soumav; Biswas, Ashik; Kour, Prachi P; Sarma, Loka S; Sur, Ujjal Kumar; Ankamwar, Balaprasad G

    2018-08-01

    In this paper, we have reported the chemical synthesis of thermally stable mesoporous nanocrystalline zirconia with high surface area using a surfactant-assisted hydrothermal approach. We have employed different type of surfactants such as CTAB, SDS and Triton X-100 in our synthesis. The synthesized nanocrystalline zirconia multistructures exhibit various morphologies such as rod, mortar-pestle with different particle sizes. We have characterized the zirconia multistructures by X-ray diffraction study, Field emission scanning electron microscopy, Attenuated total refection infrared spectroscopy, UV-Vis spectroscopy and photoluminescence spectroscopy. The thermal stability of as synthesized zirconia multistructures was studied by thermo gravimetric analysis, which shows the high thermal stability of nanocrystalline zirconia around 900 °C temperature.

  20. Thermal and mechanical behaviour of sub micron sized fly ash reinforced polyester resin composite

    Science.gov (United States)

    Nantha Kumar, P.; Rajadurai, A.; Muthuramalingam, T.

    2018-04-01

    The utilization of particles reinforced resin matrix composites is being increased owing to its lower density and high strength to weight ratio. In the present study, an attempt has been made to synthesize fly ash particles reinforced polyester resin composite for engine cowling application. The thermal stability and mechanical behaviours such as hardness and flexural strength of the composite with 2, 3 and 4 weight % of reinforcement is studied and analyzed. The thermo gravimetric analysis indicates that the higher addition of reinforcement increases the decomposition temperature due to its refractory nature. It is also observed that the hardness increases with higher filler addition owing to the resistance of FA particles towards penetration. The flexural strength is found to increase up to the addition of 3% of FA particles, whereas the polyester resin composite prepared with 4% FA particles addition is observed to have low flexural strength owing to agglomeration of particles.

  1. Biodiesel production via the transesterification of soybean oil using waste starfish (Asterina pectinifera).

    Science.gov (United States)

    Jo, Yong Beom; Park, Sung Hoon; Jeon, Jong-Ki; Ko, Chang Hyun; Ryu, Changkook; Park, Young-Kwon

    2013-07-01

    Calcined waste starfish was used as a base catalyst for the production of biodiesel from soybean oil for the first time. A batch reactor was used for the transesterification reaction. The thermal characteristics and crystal structures of the waste starfish were investigated by thermo-gravimetric analysis and X-ray diffraction. The biodiesel yield was determined by measuring the content of fatty acid methyl esters (FAME). The calcination temperature appeared to be a very important parameter affecting the catalytic activity. The starfish-derived catalyst calcined at 750 °C or higher exhibited high activity for the transesterification reaction. The FAME content increased with increasing catalyst dose and methanol-over-oil ratio.

  2. Polymeric thermal analysis of C + H and C + H + Ar ion implanted UHMWPE samples

    International Nuclear Information System (INIS)

    Kaya, N.; Oztarhan, Ahmet M.; Urkac, E.S.; Ila, D.; Budak, S.; Oks, E.; Nikolaev, A.; Ezdesir, A.; Tihminlioglu, F.; Tek, Z.; Cetiner, S.; Muntele, C.

    2007-01-01

    Chemical surface characterization of C + H hybrid ion implanted UHMWPE samples were carried out using DSC (differential scanning calorimeter) and TGA (thermal gravimetric analysis) techniques. Samples were implanted with a fluence of 10 17 ion/cm 2 and an extraction voltage of 30 kV. The study of TGA and DSC curves showed that: (1) Polymeric decomposition temperature increased (2) T m , ΔC p and ΔH m values changed while ΔC p and ΔH m increased. T g value could not be measured, because of some experimental limitations. However, the increase in ΔH m values showed that T g values increased (3) the branch density which indicated the increase in number of cross-link (M c ) decreased in ion implanted samples and (4) increase in ΔH m values indicated increase in crystallinity of implanted surface of UHMWPE samples

  3. Analysis

    DEFF Research Database (Denmark)

    Mathiesen, Brian Vad; Liu, Wen; Zhang, Xiliang

    2014-01-01

    three major technological changes: energy savings on the demand side, efficiency improvements in energy production, and the replacement of fossil fuels by various sources of renewable energy. Consequently, the analysis of these systems must include strategies for integrating renewable sources...

  4. Synthesis, characterization and physicochemical properties of nanosized Zn/Mn oxides system

    International Nuclear Information System (INIS)

    Selim, M.M.; Deraz, N.M.; Elshafey, O.I.; El-Asmy, A.A.

    2010-01-01

    A series of pure and doped Li 2 O-zinc/manganese mixed oxides was prepared by ceramic route at 400-1000 o C. The obtained solids have been characterized by the thermo-gravimetric analyzer (TGA), differential scanning calorimetry (DSC), X-ray powder diffractogram (XRD), infrared (IR), transmission electron microscopy (TEM) and energy dispersive X-ray (EDX) techniques. The catalytic behavior of pure and doped mixed solids was investigated using the decomposition reaction of H 2 O 2 at 30-50 o C. The obtained results revealed that the solid state reaction between ZnO and Mn 2 O 3 started at 500 o C yielding zinc manganite (ZnMn 2 O 4 ) nanoparticles. The augmentation in the calcination temperature of the investigated solids up to 1000 o C for 4 h brought about complete conversion of unreacted oxides yielding ZnMn 2 O 4 crystallites. By doping the system with Li 2 O at different calcination temperatures, an enhancement of the formation of zinc manganite was observed. The products obtained by doping with Li 2 O at different temperatures had less catalytic activity than the pure solids. The catalytic activity of pure and Li 2 O-doped Zn/Mn mixed oxides system decreased by increasing the calcination temperature.

  5. Preparation, characterization, and thermal properties of the microencapsulation of a hydrated salt as phase change energy storage materials

    International Nuclear Information System (INIS)

    Huang, Jin; Wang, Tingyu; Zhu, Panpan; Xiao, Junbin

    2013-01-01

    Highlights: ► Phase change point and fusion heat of samples are about 51 °Cand 150 J/g respectively. ► DSC results indicated the core material is not Na 2 HPO 4 ·12H 2 O but Na 2 HPO 4 ·7H 2 O. ► Encapsulation takes a significant role in reducing subcooling degree. - Abstract: Microcapsules loaded by disodium hydrogen phosphate heptahydrate (Na 2 HPO 4 ·7H 2 O) were prepared by means of the suspension copolymerization-solvent volatile method, with modified polymethylmethacrylate (PMMA) as coating polymer under the conditions of various organic solvents. The formation of the microencapsulated phase change materials (MEPCMs)-PMMA/Na 2 HPO 4 ·7H 2 O was investigated and analyzed. The morphology of the resultant materials was characterized by using scanning electron microscope (SEM) and phase contrast microscope. Its final composition was confirmed by the Fourier transformation infrared (FT-IR). Thermo gravimetric analyzer (TGA) and differential scanning calorimetry (DSC) were adopted to reveal its thermal stability and thermal properties. Results indicated that the materials owned improved subcooling degree and good thermal properties, enabling the materials to be one promising phase change materials for thermal energy storage

  6. Modification of chemical, optical and structural properties of Bayfol CR-6-2 using gamma and neutron irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Shehata, Mohamed M.; Radwan, Samh I.; Hassan, Amin [Atomic Energy Authority, Cairo (Egypt). Nuclear Research Centre; Waly, Sayed A. [Atomic Energy Authority, Cairo (Egypt). Second Research Reactor; Badawy, Zaynab M. [Atomic Energy Authority, Cairo (Egypt). Experimental Nuclear Physics Dept.

    2016-08-01

    The effects of gamma and neutron irradiations on the chemical, optical and structural properties of Bayfol CR-6-2 were investigated. The samples were irradiated by γ-rays from a {sup 60}Co source at various doses ranging between 16 and 900 kGy at room temperature in atmospheric air. For neutrons, an Am-Be neutron facility was used for the sample irradiation in thermal mode which had an activity of 185 GBq. Samples were irradiated with different doses of neutrons ranging from 15.7 to 564.2 mGy. The changes induced were analyzed using UV-Vis and Fourier transform infrared (FTIR) spectrometry. The results demonstrated an occurrence of oxidative degradation, resulting in the formation of carbonyl groups at 1700 cm{sup -1}. Simultaneous thermo-gravimetric investigation (TGA) has been performed on the samples of 0.3 mm thickness. The results obtained indicate that cross-linking predominates at small neutron doses and main chain scission happens at higher doses.

  7. Optimizing anti-coking abilities of zeolites by ethylene diamine tetraacetie acid modification on catalytic fast pyrolysis of corn stalk

    Science.gov (United States)

    Zhang, Bo; Zhong, Zhaoping; Song, Zuwei; Ding, Kuan; Chen, Paul; Ruan, Roger

    2015-12-01

    In order to minimize coke yield during biomass catalytic fast pyrolysis (CFP) process, ethylene diamine tetraacetie acid (EDTA) chemical modification method is carried out to selectively remove the external framework aluminum of HZSM-5 catalyst. X-ray diffraction (XRD), nitrogen (N2)-adsorption and ammonia-temperature programmed desorption (NH3-TPD) techniques are employed to investigate the porosity and acidity characteristics of original and modified HZSM-5 samples. Py-GC/MS and thermo-gravimetric analyzer (TGA) experiments are further conducted to explore the catalytic effect of modified HZSM-5 samples on biomass CFP and to verify the positive effect on coke reduction. Results show that EDTA treatment does not damage the crystal structure of HZSM-5 zeolites, but leads to a slight increase of pore volume and pore size. Meanwhile, the elimination of the strong acid peak indicates the dealumination of outer surface of HZSM-5 zeolites. Treatment time of 2 h (labeled EDTA-2H) is optimal for acid removal and hydrocarbon formation. Among all modified catalysts, EDTA-2H performs the best for deacidification and can obviously increase the yields of positive chemical compositions in pyrolysis products. Besides, EDTA modification can improve the anti-coking properties of HZSM-5 zeolites, and EDTA-2H gives rise to the lowest coke yield.

  8. Oxy-Fuel Combustion of Coal

    DEFF Research Database (Denmark)

    Brix, Jacob

    This Ph.D. thesis describes an experimental and modeling investigation of the thermal conversion of coal and an experimental investigation of the emission of NO from char combustion in O2/N2 and O2/CO2 atmospheres. The motivation for the work has been the prospective use of the technology “Oxy......-Fuel Combustion” as a mean of CO2 abatement in large scale energy conversion. Entrained Flow Reactor (EFR) experiments have been conducted in O2/N2 and O2/CO2 mixtures in the temperature interval 1173 K – 1673 K using inlet O2 concentrations between 5 – 28 vol. %. Bituminous coal has been used as fuel in all....... % it was found that char conversion rate was lowered in O2/CO2 compared to O2/N2. This is caused by the lower diffusion coefficient of O2 in CO2 (~ 22 %) that limits the reaction rate in zone III compared to combustion in O2/N2. Using char sampled in the EFR experiments ThermoGravimetric Analyzer (TGA...

  9. Effects of chemical form of sodium on the product characteristics of alkali lignin pyrolysis.

    Science.gov (United States)

    Guo, Da-liang; Yuan, Hong-you; Yin, Xiu-li; Wu, Chuang-zhi; Wu, Shu-bin; Zhou, Zhao-qiu

    2014-01-01

    The effects of Na as organic bound form or as inorganic salts form on the pyrolysis products characteristics of alkali lignin were investigated by using thermogravimetric analyzer coupled with Fourier transform infrared spectrometry (TG-FTIR), tube furnace and thermo-gravimetric analyzer (TGA). Results of TG-FTIR and tube furnace indicated that the two chemical forms Na reduced the releasing peak temperature of CO and phenols leading to the peak temperature of the maximum mass loss rate shifted to low temperature zone. Furthermore, organic bound Na obviously improved the elimination of alkyl substituent leading to the yields of phenol and guaiacol increased, while inorganic Na increased the elimination of phenolic hydroxyl groups promoting the formation of ethers. It was also found the two chemical forms Na had different effects on the gasification reactivity of chars. For inorganic Na, the char conversion decreased with increasing the char forming temperature, while organic bound Na was opposite. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  10. Preparation, characterization, and thermal properties of the microencapsulation of a hydrated salt as phase change energy storage materials

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Jin, E-mail: huangjiner@126.com [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China); Wang, Tingyu; Zhu, Panpan; Xiao, Junbin [School of Materials and Energy, Guangdong University of Technology, 510006 Guangzhou (China)

    2013-04-10

    Highlights: ► Phase change point and fusion heat of samples are about 51 °Cand 150 J/g respectively. ► DSC results indicated the core material is not Na{sub 2}HPO{sub 4}·12H{sub 2}O but Na{sub 2}HPO{sub 4}·7H{sub 2}O. ► Encapsulation takes a significant role in reducing subcooling degree. - Abstract: Microcapsules loaded by disodium hydrogen phosphate heptahydrate (Na{sub 2}HPO{sub 4}·7H{sub 2}O) were prepared by means of the suspension copolymerization-solvent volatile method, with modified polymethylmethacrylate (PMMA) as coating polymer under the conditions of various organic solvents. The formation of the microencapsulated phase change materials (MEPCMs)-PMMA/Na{sub 2}HPO{sub 4}·7H{sub 2}O was investigated and analyzed. The morphology of the resultant materials was characterized by using scanning electron microscope (SEM) and phase contrast microscope. Its final composition was confirmed by the Fourier transformation infrared (FT-IR). Thermo gravimetric analyzer (TGA) and differential scanning calorimetry (DSC) were adopted to reveal its thermal stability and thermal properties. Results indicated that the materials owned improved subcooling degree and good thermal properties, enabling the materials to be one promising phase change materials for thermal energy storage.

  11. Characterization of tea polyphenols as potential environment-friendly fire retardants

    Science.gov (United States)

    Yao, Fengqi; Zhai, Chunjie; Wang, Haihui; Tao, Junjun

    2018-02-01

    In this work we investigated the oxidation properties of tea polyphenols and their potential as the fire retardants. Two types of tea polyphenols were adopted, which were extracted from red tea and green tea leaves, respectively. Their macroscopic performance during pyrolysis and oxidation at elevated temperatures were examined by using a heating furnace. Mass change, heat evolution and gas products of tea polyphenols during heating in air were also monitored by using a thermo-gravimetric analyzer (TGA) integrated with a differential scanning calorimeter (DSC) in conjunction with online Fourier Transform Infrared Spectroscopy (FTIR) and mass spectroscopy (MS). A tea polyphenol sample first becomes a brown semi-fluid after heating, and gradually turns into highly-porous black chars with significantly expanded volume. By raising the temperature to ∼550 °C at a rate of 10 °C/min, the mass of a sample reduces by nearly 70% to form a large quantity of inert gases that are mainly composed of H2O and CO2. It was found that the aerial oxidation products of tea polyphenols in the solid phase possess good heat insulation property; meanwhile, the substantial release of a lot of water and its evaporation during oxidation of tea polyphenols removes a large amount of heat from a sample located in a heating environment. The heat insulation of tea polyphenols may withstand up to 550 °C. The present work confirms tea polyphenols as potential superior and environment-friendly fire retardants.

  12. A Combined Raman Spectroscopic and Thermogravimetric Analysis Study on Oxidation of Coal with Different Ranks

    Directory of Open Access Journals (Sweden)

    Weiqing Zhang

    2015-01-01

    Full Text Available Raman spectroscopy and nonisothermal thermogravimetric analysis (TGA measurements have been reported for different rank coals (lignite, bituminous coal, and anthracite and the relationship between the measurements was examined. It was found that the Raman spectra parameters can be used to characterize structure changes in the different rank coals, such as the band area ratios based on the curve-fitted results. Higher ranked coal was found to have higher values of IGR/IAll and IG+GR/IAll but lower values of ID/I(G+GR, IDL/I(G+GR, IS+SL/I(G+GR, and I(GL+GL'/I(G+GR. The oxidation properties of the coal samples were characterized by the reactivity indexes Tig, T20%, and Tmax from TGA data which were found to correlate well with the band area ratios of IGR/IAll, IG+GR/IAll, and IS+SL/I(G+GR. Based on these correlations, the Raman band area ratios were found to correlate with the oxidation activity of coal providing additional structural information which can be used to understand the changes in the TGA measurements.

  13. A Combined Raman Spectroscopic and Thermogravimetric Analysis Study on Oxidation of Coal with Different Ranks.

    Science.gov (United States)

    Zhang, Weiqing; Jiang, Shuguang; Hardacre, Christopher; Goodrich, Peter; Wang, Kai; Shao, Hao; Wu, Zhengyan

    2015-01-01

    Raman spectroscopy and nonisothermal thermogravimetric analysis (TGA) measurements have been reported for different rank coals (lignite, bituminous coal, and anthracite) and the relationship between the measurements was examined. It was found that the Raman spectra parameters can be used to characterize structure changes in the different rank coals, such as the band area ratios based on the curve-fitted results. Higher ranked coal was found to have higher values of I GR/I All and I (G + GR)/I All but lower values of I D/I (G+GR), I DL/I (G+GR), I (S + SL)/I (G+GR), and I (GL+GL')/I (G+GR). The oxidation properties of the coal samples were characterized by the reactivity indexes T ig, T 20%, and T max from TGA data which were found to correlate well with the band area ratios of I GR/I All, I (G + GR)/I All, and I (S + SL)/I (G+GR). Based on these correlations, the Raman band area ratios were found to correlate with the oxidation activity of coal providing additional structural information which can be used to understand the changes in the TGA measurements.

  14. Thermogravimetric analysis of atomized ferromagnetic composites with multiwalled carbon nanotubes: an unusual behavior of nickel in nanospace.

    Science.gov (United States)

    Chen, Xu; Gupta, S; Santhanam, K S V

    2014-03-01

    A spin polarization of atomized ferromagnetic atoms like cobalt or nickel in nano space results in the modification of the electron configuration in the ferromagnetic atom that changes its oxidative property. We have prepared cobalt and nickel composites with multiwalled carbon nanotubes using atomized cobalt and nickel particles, for investigating their thermal oxidative behavior by thermogravimetric analysis (TGA). The composites showed the absence of a thermal oxidation in the temperature range of ambient to the break down temperature of multiwalled carbon nanotubes at 800 degrees C. At this temperature while Co composite forms cobalt oxide, the Ni composite becomes volatile that results in the divergent behavior of the two ferromagnetic compounds with a weight gain observed in TGA for Co and a loss for Ni. The mechanisms operating in the two cases are discussed in this work.

  15. Chemical phase analysis of seed mediated synthesized anisotropic silver nanoparticles

    International Nuclear Information System (INIS)

    Bharti, Amardeep; Goyal, Navdeep; Singh, Suman; Singla, M. L.

    2015-01-01

    Noble-metal nanoparticles are of great interest because of its broad applications almost in every stream (i.e. biology, chemistry and engineering) due to their unique size/shape dependant properties. In this paper, chemical phase of seed mediated synthesized anisotropic silver nanoparticle (AgNPs) has been investigated via fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). These nanaoparticles were synthesized by seed-growth method controlled by urea and dextrose results to highly stable 12-20 nm particle size revealed by zeta potential and transmission electron microscopy (TEM)

  16. Determination of the surface density of polyethylene glycol on gold nanoparticles by use of microscale thermogravimetric analysis.

    Science.gov (United States)

    Sebby, K B; Mansfield, E

    2015-04-01

    The widespread integration of nanoparticle technologies into biomedicine will depend on the ability to repeatedly create particles with well-defined properties and predictable behaviors. For this to happen, fast, reliable, inexpensive, and widely available techniques to characterize nanomaterials are needed. Characterization of the surface molecules is particularly important since the surface, including the surface molecule density, plays a dominant role in determining how nanoparticles interact with their surroundings. Here, 10 and 30 nm gold nanoparticle NIST Standard Reference Materials were functionalized with fluorescently labeled polyethylene glycol (PEG) with either thiolate or lipoic acid anchoring groups to evaluate analytical techniques for determining surface coverage. The coating of the nanoparticles was confirmed with dynamic light scattering, microscale thermogravimetric analysis (μ-TGA), and ultraviolet-visible (UV-vis) spectroscopy. A UV-vis method for determining gold nanoparticle concentrations that takes into account spectral broadening upon functionalization was developed. The amount of bound PEG was quantified with μ-TGA, a technique analogous to thermogravimetric analysis that uses quartz crystal microbalances, and fluorescence spectroscopy of displaced ligands. It is shown that μ-TGA is a convenient technique for the quantification of ligands bound to inorganic particles while sacrificing a minimal amount of sample, and the treatment of the functionalized nanoparticle dispersions with dithiothreitol may be insufficient to achieve complete displacement of the surface ligands for quantification by fluorescence measurements. The μ-TGA and fluorescence results were used to determine ligand footprint sizes-average areas occupied by each ligand on the particles' surface. The lipoic acid bound ligands had footprint sizes of 0.21 and 0.25 nm(2) on 10 and 30 nm particles, respectively while the thiolate ligands had footprint sizes of 0.085 and 0

  17. Characterization and Exergy Analysis of Triphenyl Borate

    International Nuclear Information System (INIS)

    Acarali, N. B.

    2015-01-01

    In this study, unlike from the literature, boron oxide, borax decahydrate, boric acid and borax pentahydrate as boron sources were used to synthesize Triphenyl Borate (TPB). The reactions of TPB were carried out by using both phenol and various boron sources in inert water-immiscible organic solvent successfully. On the basis of analyzes (FT-IR, SEM, TGA/DSC) obtained, it was seen that phenol acted as a support to borate structure framework and thermal characterisation of the amorphous solid under determined conditions suggested that usage of different boron sources had effects for glass transition temperature in TPB production. The exergy analysis was performed to the TPB production to determine efficiency. The exergy analysis showed that the highest exergy efficiency was obtained by using boron oxide as a boron source. Consequently, all analyses results showed that TPB was produced successfully. Accordingly, characterization and exergy analysis supported each other. (author)

  18. Cloning and Functional Analysis of the Promoter of an Ascorbate Oxidase Gene from Gossypium hirsutum.

    Directory of Open Access Journals (Sweden)

    Shan Xin

    Full Text Available Apoplastic ascorbate oxidase (AO plays significant roles in plant cell growth. However, the mechanism of underlying the transcriptional regulation of AO in Gossypium hirsutum remains unclear. Here, we obtained a 1,920-bp promoter sequence from the Gossypium hirsutum ascorbate oxidase (GhAO1 gene, and this GhAO1 promoter included a number of known cis-elements. Promoter activity analysis in overexpressing pGhAO1::GFP-GUS tobacco (Nicotiana benthamiana showed that the GhAO1 promoter exhibited high activity, driving strong reporter gene expression in tobacco trichomes, leaves and roots. Promoter 5'-deletion analysis demonstrated that truncated GhAO1 promoters with serial 5'-end deletions had different GUS activities. A 360-bp fragment was sufficient to activate GUS expression. The P-1040 region had less GUS activity than the P-720 region, suggesting that the 320-bp region from nucleotide -720 to -1040 might include a cis-element acting as a silencer. Interestingly, an auxin-responsive cis-acting element (TGA-element was uncovered in the promoter. To analyze the function of the TGA-element, tobacco leaves transformed with promoters with different 5' truncations were treated with indole-3-acetic acid (IAA. Tobacco leaves transformed with the promoter regions containing the TGA-element showed significantly increased GUS activity after IAA treatment, implying that the fragment spanning nucleotides -1760 to -1600 (which includes the TGA-element might be a key component for IAA responsiveness. Analyses of the AO promoter region and AO expression pattern in Gossypium arboreum (Ga, diploid cotton with an AA genome, Gossypium raimondii (Gr, diploid cotton with a DD genome and Gossypium hirsutum (Gh, tetraploid cotton with an AADD genome indicated that AO promoter activation and AO transcription were detected together only in D genome/sub-genome (Gr and Gh cotton. Taken together, these results suggest that the 1,920-bp GhAO1 promoter is a functional sequence

  19. Cloning and Functional Analysis of the Promoter of an Ascorbate Oxidase Gene from Gossypium hirsutum.

    Science.gov (United States)

    Xin, Shan; Tao, Chengcheng; Li, Hongbin

    2016-01-01

    Apoplastic ascorbate oxidase (AO) plays significant roles in plant cell growth. However, the mechanism of underlying the transcriptional regulation of AO in Gossypium hirsutum remains unclear. Here, we obtained a 1,920-bp promoter sequence from the Gossypium hirsutum ascorbate oxidase (GhAO1) gene, and this GhAO1 promoter included a number of known cis-elements. Promoter activity analysis in overexpressing pGhAO1::GFP-GUS tobacco (Nicotiana benthamiana) showed that the GhAO1 promoter exhibited high activity, driving strong reporter gene expression in tobacco trichomes, leaves and roots. Promoter 5'-deletion analysis demonstrated that truncated GhAO1 promoters with serial 5'-end deletions had different GUS activities. A 360-bp fragment was sufficient to activate GUS expression. The P-1040 region had less GUS activity than the P-720 region, suggesting that the 320-bp region from nucleotide -720 to -1040 might include a cis-element acting as a silencer. Interestingly, an auxin-responsive cis-acting element (TGA-element) was uncovered in the promoter. To analyze the function of the TGA-element, tobacco leaves transformed with promoters with different 5' truncations were treated with indole-3-acetic acid (IAA). Tobacco leaves transformed with the promoter regions containing the TGA-element showed significantly increased GUS activity after IAA treatment, implying that the fragment spanning nucleotides -1760 to -1600 (which includes the TGA-element) might be a key component for IAA responsiveness. Analyses of the AO promoter region and AO expression pattern in Gossypium arboreum (Ga, diploid cotton with an AA genome), Gossypium raimondii (Gr, diploid cotton with a DD genome) and Gossypium hirsutum (Gh, tetraploid cotton with an AADD genome) indicated that AO promoter activation and AO transcription were detected together only in D genome/sub-genome (Gr and Gh) cotton. Taken together, these results suggest that the 1,920-bp GhAO1 promoter is a functional sequence with a

  20. Study on the complex Li-N-H hydrogen storage system

    Energy Technology Data Exchange (ETDEWEB)

    Du, Linnan

    2014-07-01

    Nowadays the developments of clean energy technologies become more and more necessary and important. Hydrogen-powered vehicles are a promising alternative to the current fossil fuel based vehicle infrastructure. However, so far there is still no hydrogen storage material which can fit the standards for an on-board hydrogen storage system. On this background, this work deals with the development of a hydrogen storage material. The focus is put on the Lithium amide + Lithium hydride (LiNH{sub 2}+LiH) hydrogen storage system because of its high theoretical capacity and relatively low desorption temperature. Moreover, Lithium amide + Magnesium hydride (LiNH{sub 2}+MgH{sub 2}) as an alternative system was also briefly studied. The aims of this work are to achieve a deeper understanding of the reaction mechanism with the help of microstructural and thermodynamic studies, building a model to describe the sorption process and then to improve the system properties. As the desorption from LiNH{sub 2} particles is the first step of the desorption process of the LiNH{sub 2}+LiH system, the properties and sorption behavior of LiNH{sub 2} sample materials were studied separately first. So the work in this thesis can be mainly divided into two parts: LiNH{sub 2} samples and LiNH{sub 2}+LiH samples. In order to activate the sample materials, both dry ball milling and wet ball milling (with tetrahydrofuran) methods were used. Boron nitride was mainly applied as catalyst. Furthermore, titanium tetrachloride was also used as an alternative additive. The sorption behaviors were studied with the help of a volumetric and a gravimetric system. Further investigation methods include X-ray Diffraction (XRD) method, Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET) method, Differential Thermal Analysis (DTA)/ Thermo Gravimetric Analysis (TGA)/ Mass Spectrometry (MS), and others. The results obtained in this work show that no obvious microstructure differences have been found

  1. Study on the complex Li-N-H hydrogen storage system

    International Nuclear Information System (INIS)

    Du, Linnan

    2014-01-01

    Nowadays the developments of clean energy technologies become more and more necessary and important. Hydrogen-powered vehicles are a promising alternative to the current fossil fuel based vehicle infrastructure. However, so far there is still no hydrogen storage material which can fit the standards for an on-board hydrogen storage system. On this background, this work deals with the development of a hydrogen storage material. The focus is put on the Lithium amide + Lithium hydride (LiNH 2 +LiH) hydrogen storage system because of its high theoretical capacity and relatively low desorption temperature. Moreover, Lithium amide + Magnesium hydride (LiNH 2 +MgH 2 ) as an alternative system was also briefly studied. The aims of this work are to achieve a deeper understanding of the reaction mechanism with the help of microstructural and thermodynamic studies, building a model to describe the sorption process and then to improve the system properties. As the desorption from LiNH 2 particles is the first step of the desorption process of the LiNH 2 +LiH system, the properties and sorption behavior of LiNH 2 sample materials were studied separately first. So the work in this thesis can be mainly divided into two parts: LiNH 2 samples and LiNH 2 +LiH samples. In order to activate the sample materials, both dry ball milling and wet ball milling (with tetrahydrofuran) methods were used. Boron nitride was mainly applied as catalyst. Furthermore, titanium tetrachloride was also used as an alternative additive. The sorption behaviors were studied with the help of a volumetric and a gravimetric system. Further investigation methods include X-ray Diffraction (XRD) method, Scanning Electron Microscope (SEM), Brunauer-Emmett-Teller (BET) method, Differential Thermal Analysis (DTA)/ Thermo Gravimetric Analysis (TGA)/ Mass Spectrometry (MS), and others. The results obtained in this work show that no obvious microstructure differences have been found between the wet ball milled and dry

  2. Influence of Particle Size on Properties of Expanded Graphite

    Directory of Open Access Journals (Sweden)

    Kurajica, S

    2010-02-01

    between the graphene layers due to oxidation and repulsion of positively charged layers. The increased width and reduced height of diffraction peaks were a consequence of small-sized ordered domains. The intercalation is partial, intercalated layers are divided by a considerable number of non-intercalated layers. FTIR spectra revealed that dominant intercalating species is perchloric acid.Thermo-gravimetric analysis revealed that deintercalation occurs in the temperature interval between 150 and 300 °C and that a mass loss in this temperature interval is dependent on particle diameter, i. e. the intercalation is more intensive for greater particles. The fact that deintercalation proceeds as a one-stage process indicates the existence of only one intercalating specie. Additional mass loss at higher temperatures is a consequence of graphite oxidation.The particles with a higher amount of interlcalant showed greater expansion volumes as well as specific surface area. The fraction with greatest particle diameter (315–425 µm showed expansion specific volume of v=86 cm3g–1. Weaker expansion of smaller particles is a consequence of intercalant thermal degradation gaseous products loss at the layer edges, as well as of lesser amount of intercalants due to their removal during washing.Adsorption-desorption isotherms of expanded graphite could be classified as type III, according to BDDT/IUPAC classification, characteristic for macro porous materials. Small variations in adsorption and desorption pressure for the same amount of adsorbed gas indicate that the macro pores are open. Specific surface area was calculated using BET equation and for sample 315–425 yields s = 36 m2 g–1.SEM micrographs revealed typical worm-like microstructure generated by exfoliation of graphene sheets. The areas of intense exfoliation forming typical pores, as well as less exfoliated sheets canbe observed.

  3. Mesoporous Nb and Ta Oxides: Synthesis, Characterization and Applications in Heterogeneous Acid Catalysis

    Science.gov (United States)

    Rao, Yuxiang Tony

    In this work, a series of mesoporous Niobium and Tantalum oxides with different pore sizes (C6, C12, C18 , ranging from 12A to 30 A) were synthesized using the ligand-assisted templating approach and investigated for their activities in a wide range of catalytic applications including benzylation, alkylation and isomerization. The as-synthesized mesoporous materials were characterized by nitrogen adsorption, powder X-ray diffraction, transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermo gravimetric analysis (TGA), differential scanning calorimetry (DSC), and solid-state Nuclear magnetic resonance (NMR) techniques. In order to probe into the structural and coordination geometry of mesoporous Nb oxide and in efforts to make meaningful comparisons of mesoporous niobia prepared by the amine-templating method with the corresponding bulk sol-gel prepared Nb2O5 phase, 17O magic-angle-spinning solid-state NMR studies were conducted. The results showed a very high local order in the mesoporous sample. The oxygen atoms are coordinated only as ONb 2 in contrast with bulk phases in which the oxygen atoms are always present in a mixture of ONb2 and ONb3 coordination environments. To enhance their surface acidities and thus improve their performance as solid acid catalysts in the acid-catalyzed reactions mentioned above, pure mesoporous Nb and Ta oxides were further treated with 1M sulfuric acid or phosphoric acid. Their surface acidities before and after acid treatment were measured by Fourier transform infraRed (FT IR), amine titration and temperature programmed desorption of ammonia (NH3-TPD). Results obtained in this study showed that sulfated mesoporous Nb and Ta oxides materials possess relative high surface areas (up to 612 m 2/g) and amorphous wormhole structure. These mesoporous structures are thus quite stable to acid treatment. It was also found that Bronsted (1540 cm-1) and Lewis (1450 cm-1) acid sites coexist in a roughly 50:50 mixture

  4. Magnetic nanoparticles for bio-analytical applications

    Science.gov (United States)

    Yedlapalli, Sri Lakshmi

    Magnetic nanoparticles are widely being used in various fields of medicine, biology and separations. This dissertation focuses on the synthesis and use of magnetic nanoparticles for targeted drug delivery and analytical separations. The goals of this research include synthesis of biocompatible surface modified monodisperse superparamagnetic iron oxide nanoparticles (SPIONs) by novel techniques for targeted drug delivery and use of SPIONs as analytical sensing tools. Surface modification of SPIONs was performed with two different co-polymers: tri block co-polymer Pluronics and octylamine modified polyacrylic acid. Samples of SPIONs were subsequently modified with 4 different commercially available, FDA approved tri-block copolymers (Pluronics), covering a wide range of molecular weights (5.75-14.6 kDa). A novel, technically simpler and faster phase transfer approach was developed to surface modify the SPIONs with Pluronics for drug delivery and other biomedical applications. The hydrodynamic diameter and aggregation properties of the Pluronic modified SPIONs were studied by dynamic light scattering (DLS). The coverage of SPIONs with Pluronics was supported with IR Spectroscopy and characterized by Thermo gravimetric Analysis (TGA). The drug entrapment capacity of SPIONs was studied by UV-VIS spectroscopy using a hydrophobic carbocyanine dye, which serves as a model for hydrophobic drugs. These studies resulted in a comparison of physical properties and their implications for drug loading capacities of the four types of Pluronic coated SPIONs for drug delivery assessment. These drug delivery systems could be used for passive drug targeting. However, Pluronics lack the functional group necessary for bioconjugation and hence cannot achieve active targeting. SPIONs were functionalized with octylamine modified polyacrylic acid-based copolymer, providing water solubility and facile biomolecular conjugation. Epirubicin was loaded onto SPIONs and the drug entrapment was

  5. QTL analysis by sequencing of Water Use Efficiency (WUE) in potato

    DEFF Research Database (Denmark)

    Kaminski, Kacper Piotr; Sønderkær, Mads; Sørensen, Kirsten Kørup

    2013-01-01

    The traditional approach to potato breeding, the classical “mate and phenotype” approach is relatively costly and because phenotyping and growth capacity is limited, this are being slowly replaced by Marker Assisted Selection (MAS) breeding schemes. MAS is based on the presence of DNA polymorphic.......sparsipilum), phenotyped for water use efficiency. This population has also previously been phenotyped for the total glycoalkaloid (TGA) content....... and time consuming process. Here, a novel method for Quantitative Trait Locus (QTL) analysis has been developed, that allows for development of specific markers by use of genomic sequence reads and the recently published reference genome sequence for potato. Prior to sequencing the mapping population...

  6. Thermal analysis of polypropylene modified by gamma irradiation composites under outdoor conditions

    International Nuclear Information System (INIS)

    Komatsu, Luiz G.H.; Oliani, Washington L.; Lugao, Ademar B.; Parra, Duclerc F.

    2015-01-01

    This work reports the influence of the clay in the degradation process of the HMSPP.The polypropylene (PP) was irradiated under acetylene atmosphere in gamma irradiation source ( 60 Co) to obtain the HMSPP (high melt strength polypropylene). Composites of HMSPP were processed in twin-screw extruder with clay Cloisite 20A and Maleic Anhydride (PP-g-MA) as coupling agent. The obtained composites were exposed under outdoor conditions for 6 months. The ageing effects were characterized by Differential Scanning Calorimetry (DSC), Thermogravimetry Analysis (TGA). Chemical oxidation was evaluated by Carbonyl Index (IC) through infrared Spectroscopy (FT-IR). The results showed correlation between carbonyl index and ageing time. (author)

  7. Thermal analysis of polypropylene modified by gamma irradiation composites under outdoor conditions

    Energy Technology Data Exchange (ETDEWEB)

    Komatsu, Luiz G.H.; Oliani, Washington L.; Lugao, Ademar B.; Parra, Duclerc F., E-mail: dfparra@ipen.br [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2015-07-01

    This work reports the influence of the clay in the degradation process of the HMSPP.The polypropylene (PP) was irradiated under acetylene atmosphere in gamma irradiation source ({sup 60}Co) to obtain the HMSPP (high melt strength polypropylene). Composites of HMSPP were processed in twin-screw extruder with clay Cloisite 20A and Maleic Anhydride (PP-g-MA) as coupling agent. The obtained composites were exposed under outdoor conditions for 6 months. The ageing effects were characterized by Differential Scanning Calorimetry (DSC), Thermogravimetry Analysis (TGA). Chemical oxidation was evaluated by Carbonyl Index (IC) through infrared Spectroscopy (FT-IR). The results showed correlation between carbonyl index and ageing time. (author)

  8. Ionic liquid thermal stabilities: decomposition mechanisms and analysis tools.

    Science.gov (United States)

    Maton, Cedric; De Vos, Nils; Stevens, Christian V

    2013-07-07

    The increasing amount of papers published on ionic liquids generates an extensive quantity of data. The thermal stability data of divergent ionic liquids are