Hydrogen Sorption Behavior in Conducting Polymer Nanostructures

2009 ◽  
Author(s):  
Michael U. Niemann ◽  
Sesha S. Srinivasan ◽  
Ayala R. Phani ◽  
Ashok Kumar ◽  
D. Yogi Goswami ◽  
...  
Keyword(s):  
Electrospun Nanofibers ◽  
Hydrogen Uptake ◽  
Hydrogen Sorption ◽  
Sorption Behavior ◽  
High Hydrogen ◽  
Templating Method ◽  
Polyaniline Nanofibers ◽  
Before And After ◽  
Different Temperatures ◽  
Saturation Effects

Conducting polyaniline nanofibers were synthesized using chemical templating method followed by electrospun process. These nanofibers have been compared with their standard bulk counterpart and found to be stable up to 150°C. Polyaniline nanofibers prepared by electrospun method reveal high hydrogen uptake of 10wt.% at around 100°C in the first absorption run. However, in the consecutive hydrogenation and dehydrogenation cycles, the hydrogen capacity diminishes. This is most likely due to hydrogen loading into the polymer matrix, chemisorption and saturation effects. A reversible hydrogen storage capacity of ∼3–10 wt.% was also found in the new batch of electrospun nanofibers at different temperatures. The surface morphologies before and after hydrogen sorption of these PANI nanofibers encompass significant changes in the microstructure (nanofibrallar swelling effect) which clearly suggest effective hydrogen uptake and release.

scholarly journals Experimental Investigation of Wave Velocity-Permeability Model for Granite Subjected to Different Temperature Processing

Geofluids ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Guanghui Jiang ◽  
Jianping Zuo ◽  
Teng Ma ◽  
Xu Wei
Keyword(s):  
Particle Size ◽  
High Temperature ◽  
Wave Velocity ◽  
Pore Fluid ◽  
Rock Matrix ◽  
Permeability Model ◽  
Wave Velocities ◽  
Before And After ◽  
Different Temperatures ◽  
Increasing Temperature

Understanding the change of permeability of rocks before and after heating is of great significance for exploitation of hydrocarbon resources and disposal of nuclear waste. The rock permeability under high temperature cannot be measured with most of the existing methods. In this paper, quality, wave velocity, and permeability of granite specimen from Maluanshan tunnel are measured after high temperature processing. Quality and wave velocity of granite decrease and permeability of granite increases with increasing temperature. Using porosity as the medium, a new wave velocity-permeability model is established with modified wave velocity-porosity formula and Kozeny-Carman formula. Under some given wave velocities and corresponding permeabilities through experiment, the permeabilities at different temperatures and wave velocities can be obtained. By comparing the experimental and the theoretical results, the proposed formulas are verified. In addition, a sensitivity analysis is performed to examine the effect of particle size, wave velocities in rock matrix, and pore fluid on permeability: permeability increases with increasing particle size, wave velocities in rock matrix, and pore fluid; the higher the rock wave velocity, the lower the effect of wave velocities in rock matrix and pore fluid on permeability.

scholarly journals MECHANICAL CHARACTERIZATION OF PA 12 AND HDPE PIPES BEFORE AND AFTER AGING IN WATER AT TWO DIFFERENT TEMPERATURES

2021 ◽  
Vol 9 (1) ◽  
pp. 248-256
Author(s):  
J.A. dos Santos ◽  
R.C. Tucunduva ◽  
J.R.M. D’Almeida
Keyword(s):  
High Density Polyethylene ◽  
Mechanical Performance ◽  
High Density ◽  
Effect Of Temperature ◽  
Polyamide 12 ◽  
Polyethylene Pipes ◽  
Before And After ◽  
Different Temperatures ◽  
Deterioration Process ◽  
Combined Action

Polymer pipes are being widely used by many industrial segments. Although not affected by corrosion, the mechanical performance of these pipes can be reduced due to exposure to temperature, UV radiation and by contact with various fluids. Depending on the deterioration process, embrittlement or plasticization may occur, and the service life of the pipe can be severely reduced. In this work, the combined action of temperature and water upon the mechanical performance of polyamide 12 and high-density polyethylene pipes is evaluated. Destructive and non-destructive techniques were used and the performance of both materials was compared. Both polymers were platicized by the effect of water. However, for high density polyethylene the effect of temperature was more relevant than for polyamide. This behavior was attributed to the dependence of the free volume with the markedly different glass transition temperature of the polymers and the temperatures of testing.

scholarly journals Laterality of Blood Perfusion in the Lower Extremities after Drinking Saline at Different Temperatures

2021 ◽  
Author(s):  
Shuyong Jia ◽  
Qizhen Wang ◽  
Hongyan Li ◽  
Xiaojing Song ◽  
Shuyou Wang ◽  
...  
Keyword(s):  
Root Mean Square ◽  
Cold Water ◽  
Lower Extremities ◽  
Blood Perfusion ◽  
Dominant Frequency ◽  
Frequency Interval ◽  
Mean Square ◽  
Laterality Index ◽  
Before And After ◽  
Different Temperatures

Abstract Background: Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in the digestive system. However, the distribution and regulation of bilateral blood flow are not symmetrical but exhibit a certain laterality. The aim of this study was to analyze the laterality of skin blood flux after drinking saline (0.9%) at different temperatures by monitoring blood flux in the bilateral lower extremities.Methods: A total of 60 subjects were recruited for this study, and all subjects completed all measurements. Subjects were randomly divided into a 4 °C group, 10 °C group and 30 °C group. For every subject, skin blood perfusion of bilateral Zusanli acupoints (ST 36) was recorded simultaneously before and after drinking 500 ml of 0.9% saline using a PeriFlux System 5000. The electrogastrogram (EGG) was also monitored, and the dominant frequency of the EGG and heart rate variability were analyzed.Results: The results indicated that after drinking saline at different temperatures, the laterality index of skin blood flux at the lower extremities was different. Drinking 30 °C saline can increase the laterality index of the lower extremities. The results of wavelet analysis showed that the laterality index changes of skin blood flux were mainly reflected in the frequency interval V (0.4-1.6 Hz). Stimulation at 4 °C and 10 °C resulted in a decrease in the dominant frequency (DF) of the electrogastrogram and an increased root mean square of successive differences (RMSSD) of the RR interval. There was a weak negative correlation between the laterality index of frequency interval I or II and root mean square of successive differences.Conclusion: There was laterality of blood perfusion in the lower extremities after drinking saline at different temperatures.

scholarly journals Laterality of Blood Perfusion in the Lower Extremities after Drinking Saline at Different Temperatures

2020 ◽  
Author(s):  
Shuyong Jia ◽  
Qizhen Wang ◽  
Hongyan Li ◽  
Xiaojing Song ◽  
Shuyou Wang ◽  
...  
Keyword(s):  
Cold Water ◽  
Lower Extremities ◽  
Blood Perfusion ◽  
Dominant Frequency ◽  
Frequency Interval ◽  
Laterality Index ◽  
Skin Blood Perfusion ◽  
Before And After ◽  
Different Temperatures ◽  
Weak Negative Correlation

Abstract Background: Skin blood flux (SkBF) changes caused by drinking cold water are generally associated with vagal tone and osmotic factors in the digestive system. However, the distribution and regulation of bilateral blood flow are not symmetrical but exhibit a certain laterality. The aim of this study was to analyze the laterality of SkBF after drinking saline (0.9%) at different temperatures by monitoring blood flux in the bilateral lower extremities.Methods: A total of 60 subjects were recruited for this study, and all subjects completed all measurements. Subjects were randomly divided into a 4 °C group, 10 °C group and 30 °C group. For every subject, skin blood perfusion of bilateral Zusanli acupoints (ST 36) was recorded simultaneously before and after drinking 500 ml of 0.9% saline using a PeriFlux System 5000. The electrogastrogram (EGG) was also monitored, and the dominant frequency of the EGG and heart rate variability were analyzed.Results: The results indicated that after drinking saline at different temperatures, the laterality index of SkBF at the lower extremities was different. Drinking 30 °C saline can increase the laterality index of the lower extremities. Stimulation at 4 °C and 10 °C resulted in a decrease in the DF of the EGG and an increased RMSSD of the RR interval. Although this laterality is mainly contributed to by frequency interval V, there was a weak negative correlation between the laterality index of frequency interval I or II and RMSSD.Conclusion: There was laterality of blood perfusion in the lower extremities after drinking saline at different temperatures.

scholarly journals Alternative foaming agents for fabrication of glass foam

2021 ◽  
Vol 11 (5) ◽  
pp. 39-48
Author(s):  
Ildikó Fóris ◽  
Gábor Mucsi
Keyword(s):  
Raw Materials ◽  
Powder Mixtures ◽  
Foaming Agent ◽  
Foaming Agents ◽  
Heat Treated ◽  
Specimen Density ◽  
Before And After ◽  
Different Temperatures ◽  
Glass Foam ◽  
Eggshell Waste

Glass foam tablets were produced from container glass bottles (CGB) using eggshell waste (ESW) and perlite (P) as foaming agent in different portions. The ground raw materials (CGB, ESW, P) were homogenized and pressed with hydraulic piston press machine at different pressures (in the case of P containing tablets 30 MPa and ESW containing tablets 15 MPa, 30 MPa and 40 MPa were used).The obtained glass tablets were heat treated at different temperatures (in the case of P containing tablets 800 °C, 900°C, 1000°C and 1100°C, and ESW containing tablets 600 °C, 700 °C, 800 °C and 900 °C were used). The study shows the specimen density of tablets before and after heat treatment, as well as the true density of the powder mixtures before tableting and the abrasion resistance of the glass foam products.

Thermal Stablility and Oxidation Resistance of CrAlSiN Nano-Structured Coatings Deposited by Lateral Rotating Cathode Arc

2010 ◽  
Vol 447-448 ◽  
pp. 725-729 ◽  
Author(s):  
Jhun Yew Cheong ◽  
Xing Zhao Ding ◽  
Beng Kang Tay ◽  
Xian Ting Zeng
Keyword(s):  
Oxidation Resistance ◽  
Deposition Process ◽  
Surface Oxide Layer ◽  
Ambient Atmosphere ◽  
Temperature Oxidation ◽  
X Ray ◽  
Good Oxidation Resistance ◽  
Before And After ◽  
Different Temperatures ◽  
Cathode Arc

In this paper, CrAlSiN coatings are deposited by a lateral rotating cathode arc technique. The high temperature oxidation behaviors of these coatings are studied in ambient atmosphere at temperatures ranging from 800°C-1000°C for an hour. The ternary TiAlN coating is used as the benchmark in this study. The surface morphology and chemical composition of the coating samples before and after oxidation at different temperatures are analyzed by scanning electron microscopy (SEM) equipped by energy dispersive X-ray spectrometer (EDX), glow discharge optical spectrometry (GDOS) and X-ray diffraction (XRD). The CrAlSiN coatings show much better oxidation resistance than the TiAlN coatings. TiAlN starts to oxidize from 800oC and forms a complete surface oxide layer after oxidation at 1000oC for an hour. However, CrAlSiN shows a relatively good oxidation resistance below 1000oC and only is oxidized to form a thin oxide scale with a thickness of 0.3 µm at 1000oC for one hour. It is found that the oxidation of both coatings is triggered from the surface metallic droplets generated by the arc deposition process.

Microstructural and Fractographic Analysis of CuAlNi Shape Memory Alloy before and after Heat Treatment

2020 ◽  
Vol 405 ◽  
pp. 100-106
Author(s):  
Ivana Ivanić ◽  
Mirko Gojić ◽  
Stjepan Kožuh ◽  
Borut Kosec
Keyword(s):  
Heat Treatment ◽  
Shape Memory Alloy ◽  
Fracture Surface ◽  
Shape Memory ◽  
Fractographic Analysis ◽  
Before And After ◽  
Different Temperatures ◽  
The Difference ◽  
Type Of Fracture ◽  
Scanning Electron

The paper presents comparison of microstructure and fracture surface morphology of the CuAlNi shape memory alloy (SMA) after different heat treatment procedures. The investigation was performed on samples in as-cast state and heat treated states (solution annealing at temperatures of 850 °C / 60’ / H2O and 920 °C / 60’ / H2O along with tempering at two different temperature 150 °C / 60’ / H2O and 300 °C / 60’ / H2O). The microstructure of the samples was examined by optical (OM) and scanning electron microscope (SEM) equipped with device for EDS analysis. The obtained fracture surfaces were examined by SEM. Optical and scanning electron microscopy showed martensitic microstructure in all investigated samples. However, the fractographic analysis of samples after tensile testing reveals significant changes in fracture mechanism. In both solution annealed states the results shows transgranular type of fracture, but after tempering at two different temperatures the difference is obvious. After tempering at 150 °C, along with transgranular type of fracture appear some areas with intergranular type of fracture. After tempering at 300 °C, fracture surface reveals completely intergranular type of fracture.

scholarly journals Influence of Defects on the Stability and Hydrogen‐Sorption Behavior of Mg‐Based Hydrides

ChemPhysChem ◽  
2019 ◽  
Vol 20 (10) ◽  
pp. 1216-1247 ◽  
Author(s):  
Jasmina Grbović Novaković ◽  
Nikola Novaković ◽  
Sandra Kurko ◽  
Sanja Milošević Govedarović ◽  
Tijana Pantić ◽  
...  
Keyword(s):  
Hydrogen Sorption ◽  
Sorption Behavior ◽  
The Stability

Thermal Stability of Cu/Si (111) Films Prepared by Ionized Cluster Beam Technique

2011 ◽  
Vol 287-290 ◽  
pp. 2369-2372
Author(s):  
Bo Cao ◽  
Yan Hui Jia ◽  
Gong Ping Li ◽  
Seong Jin Cho ◽  
Hee Kim
Keyword(s):  
Rutherford Backscattering Spectrometry ◽  
Interface Reaction ◽  
Atomic Diffusion ◽  
Cluster Beam ◽  
Copper Silicide ◽  
Cu Films ◽  
Si Substrates ◽  
Before And After ◽  
Different Temperatures ◽  
Cluster Beams

The Cu films were deposited on P type Si (111) substrates by ionized cluster beam (ICB) technique. The interface reaction and atomic diffusion of Cu/Si (111) system were studied at different annealing temperatures by X-ray diffraction (XRD) and Rutherford backscattering spectrometry (RBS). Some significant results were obtained: For the Cu/Si (111) samples prepared by ionized cluster beams atVa=3 kV, the interdiffusion of Cu and Si atoms occurred in the as deposited samples. The RBS spectra features were changed with a very small extent with increasing the annealing temperature. There are no copper-silicide phases observed by XRD before and after being annealed at different temperatures. The reason may be that there is a thermally stable interface between Cu films and Si substrates formed.

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