scholarly journals THE EFFECTS OF DIFFERENT SONICATION TIMES OF NICKEL OXIDE AND ZIRCONIUM OXIDE CATALYSTS IN SYNGAS PRODUCTION

2018 ◽  
Vol 80 (6) ◽  
Author(s):  
Y. C. Wong ◽  
W. A. Wan Nurdiyana ◽  
Y. H. Taufiq Yap
Keyword(s):  
Electron Microscopy ◽  
Nickel Oxide ◽  
Surface Area ◽  
Zirconium Oxide ◽  
Treatment Duration ◽  
Reactive Oxygen ◽  
Oxygen Removal ◽  
Surface Measurement ◽  
Heterogeneous Catalytic ◽  
Syngas Production

Heterogeneous catalytic cracking is currently one of the most effective ways for both reducing tar content and enhancing hydrogen (H2) content in syngas at relatively low temperature, besides being environmental friendly. Sonochemical treatment has also been shown to lower reaction times with enhanced reaction rate and enables production of particles with high surface area. In this study, two different types of metal oxides, which are Nickel oxide (NiO) and Zirconium oxide (ZrO2) at a combination of 1:1 ratio with Zeolite as the supporter are synthesized via sonochemical treatment in durations of 30, 60 and 90 minutes. The catalysts are then characterized using X-Ray Diffraction (XRD), Temperature Programmed Reduction (TPR-H2), Brunauer-Emmett-Teller surface measurement (BET), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). From SEM and TEM analysis, Nickel tends to agglomerate and form sizable globular shapes, Zirconium forms coral-like branching structure and Zeolite forms stacks of cubic clumps. The most promising sonication treatment duration for the catalysts is 30 minutes because it removes decent amount of reactive oxygen at a rate of 0.83 x 1021 atoms/g during hydrogen reduction, possesses the highest surface area of 506.52 m2/g as well as smallest average crystallite size of 56.9 nm compared to other durations. Generally sonochemical treatment also increases the catalysts surface area and oxygen removal as well as lowers the reduction temperature which is favourable in term of production cost. Catalysts with sonochemical treatment duration of 30 and 60 minutes generally show higher reactive oxygen removal and surface area compared to catalysts with 90 minute treatments.

The Microstructure of Nickel Oxide Scales

1981 ◽  
Vol 39 ◽  
pp. 86-87
Author(s):  
M. T. Tinker ◽  
L. W. Hobbs
Keyword(s):  
Electron Microscopy ◽  
Nickel Oxide ◽  
Ion Beam ◽  
Oxide Scales ◽  
Nickel Substrate ◽  
Outward Diffusion ◽  
Transmission Electron ◽  
Nickel Substrates ◽  
Nickel Base ◽  
Technological Interest

There is considerable technological interest in oxidation of nickel because of the importance of nickel-base superalloys in high-temperature oxidizing environments. NiO scales on nickel grow classically, by outward diffusion of nickel through the scale, and are among the most studied of oxidation systems. We report here the first extensive characterization by transmission electron microscopy of nickel oxide scales formed on bulk nickel substrates and sectioned both parallel and transversely to the Ni/NiO interface.Electrochemically-polished nickel sheet of 99.995% purity was oxidized at 1273 K in 0.1 MPa oxygen partial pressure for times between 5 s and 25 h. Parallel sections were produced using a combination of electropolishing of the nickel substrate and ion-beam thinning of the scale to any desired depth in the scale. Transverse sections were prepared by encasing stacked strips of oxidized nickel sheet in epoxy resin, sectioning transversely and ion-beam thinning until thin area spanning one or more interfaces was obtained.

scholarly journals Phytosynthetic Fabrication of Lanthanum Ion-Doped Nickel Oxide Nanoparticles Using Sesbania grandiflora Leaf Extract and Their Anti-Microbial Properties

Crystals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 124
Author(s):  
Srihasam Saiganesh ◽  
Thyagarajan Krishnan ◽  
Golla Narasimha ◽  
Hesham S. Almoallim ◽  
Sulaiman Ali Alhari ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Optical Properties ◽  
Rare Earth ◽  
Nickel Oxide ◽  
Photoelectron Spectroscopy ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Nio Nanoparticles ◽  
X Ray ◽  
Sesbania Grandiflora

Over the past few years, the photogenic fabrication of metal oxide nanoparticles has attracted considerable attention, owing to the simple, eco-friendly, and non-toxic procedure. Herein, we fabricated NiO nanoparticles and altered their optical properties by doping with a rare earth element (lanthanum) using Sesbania grandiflora broth for antibacterial applications. The doping of lanthanum with NiO was systematically studied. The optical properties of the prepared nanomaterials were investigated through UV-Vis diffuse reflectance spectra (UV-DRS) analysis, and their structures were studied using X-ray diffraction analysis. The morphological features of the prepared nanomaterials were examined by scanning electron microscopy and transmission electron microscopy, their elemental structure was analyzed by energy-dispersive X-ray spectral analysis, and their oxidation states were analyzed by X-ray photoelectron spectroscopy. Furthermore, the antibacterial action of NiO and La-doped NiO nanoparticles was studied by the zone of inhibition method for Gram-negative and Gram-positive bacterial strains such as Escherichia coli and Bacillus sublitis. It was evident from the obtained results that the optimized compound NiOLa-04 performed better than the other prepared compounds. To the best of our knowledge, this is the first report on the phytosynthetic fabrication of rare-earth ion Lanthanum (La3+)-doped Nickel Oxide (NiO) nanoparticles and their anti-microbial studies.

Prebiotic studies on the interaction of zirconia nanoparticles and ribose nucleotides and their role in chemical evolution

2021 ◽  
Vol 20 (2) ◽  
pp. 142-149
Author(s):  
Avnish Kumar Arora ◽  
Pankaj Kumar
Keyword(s):  
Electron Microscopy ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Chemical Evolution ◽  
Ribonucleic Acid ◽  
Zirconium Oxide ◽  
Origins Of Life ◽  
Neutral Ph ◽  
Interaction Studies

AbstractStudies on the interaction of biomolecules with inorganic compounds, mainly mineral surfaces, are of great concern in identifying their role in chemical evolution and origins of life. Metal oxides are the major constituents of earth and earth-like planets. Hence, studies on the interaction of biomolecules with these minerals are the point of concern for the study of the emergence of life on different planets. Zirconium oxide is one of the metal oxides present in earth's crust as it is a part of several types of rocks found in sandy areas such as beaches and riverbeds, e.g. pebbles of baddeleyite. Different metal oxides have been studied for their role in chemical evolution but no studies have been reported about the role of zirconium oxide in chemical evolution and origins of life. Therefore, studies were carried out on the interaction of ribonucleic acid constituents, 5′-CMP (cytidine monophosphate), 5′-UMP (uridine monophosphate), 5′-GMP (guanosine monophosphate) and 5′-AMP (adenosine monophosphate), with zirconium oxide. Synthesized zirconium oxide particles were characterized by using vibrating sample magnetometer, X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy. Zirconia particles were in the nanometre range, from 14 to 27 nm. The interaction of zirconium oxide with ribonucleic acid constituents was performed in the concentration range of 5 × 10−5–300 × 10−5 M. Interaction studies were carried out in three mediums; acidic (pH 4.0), neutral (pH 7.0) and basic (pH 9.0). At neutral pH, maximum interaction was observed. The interaction of zirconium oxide with 5′-UMP was 49.45% and with 5′-CMP 67.98%, while with others it was in between. Interaction studies were Langmurian in nature. Xm and KL values were calculated. Infrared spectral studies of ribonucleotides, metal oxide and ribonucleotide–metal oxide adducts were carried out to find out the interactive sites. It was observed that the nitrogen base and phosphate moiety of ribonucleotides interact with the positive charge surface of metal oxide. SEM was also carried out to study the adsorption. The results of the present study favour the important role of zirconium oxide in concentrating the organic molecules from their dilute aqueous solutions in primeval seas.

scholarly journals Magnetically Recyclable Wool Keratin Modified Magnetite Powders for Efficient Removal of Cu2+ Ions from Aqueous Solutions

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1068
Author(s):  
Xinyue Zhang ◽  
Yani Guo ◽  
Wenjun Li ◽  
Jinyuan Zhang ◽  
Hailiang Wu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solutions ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Ion Concentration ◽  
Bet Surface Area ◽  
Chemical Compositions ◽  
Ion Adsorption ◽  
X Ray ◽  
Wool Keratin

The treatment of wastewater containing heavy metals and the utilization of wool waste are very important for the sustainable development of textile mills. In this study, the wool keratin modified magnetite (Fe3O4) powders were fabricated by using wool waste via a co-precipitation technique for removal of Cu2+ ions from aqueous solutions. The morphology, chemical compositions, crystal structure, microstructure, magnetism properties, organic content, and specific surface area of as-fabricated powders were systematically characterized by various techniques including field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), vibrating sample magnetometer (VSM), thermogravimetric (TG) analysis, and Brunauer–Emmett–Teller (BET) surface area analyzer. The effects of experimental parameters such as the volume of wool keratin hydrolysate, the dosage of powder, the initial Cu2+ ion concentration, and the pH value of solution on the adsorption capacity of Cu2+ ions by the powders were examined. The experimental results indicated that the Cu2+ ion adsorption performance of the wool keratin modified Fe3O4 powders exhibited much better than that of the chitosan modified ones with a maximum Cu2+ adsorption capacity of 27.4 mg/g under favorable conditions (0.05 g powders; 50 mL of 40 mg/L CuSO4; pH 5; temperature 293 K). The high adsorption capacity towards Cu2+ ions on the wool keratin modified Fe3O4 powders was primarily because of the strong surface complexation of –COOH and –NH2 functional groups of wool keratins with Cu2+ ions. The Cu2+ ion adsorption process on the wool keratin modified Fe3O4 powders followed the Temkin adsorption isotherm model and the intraparticle diffusion and pseudo-second-order adsorption kinetic models. After Cu2+ ion removal, the wool keratin modified Fe3O4 powders were easily separated using a magnet from aqueous solution and efficiently regenerated using 0.5 M ethylene diamine tetraacetic acid (EDTA)-H2SO4 eluting. The wool keratin modified Fe3O4 powders possessed good regenerative performance after five cycles. This study provided a feasible way to utilize waste wool textiles for preparing magnetic biomass-based adsorbents for the removal of heavy metal ions from aqueous solutions.

Comparative ultrastructural analysis of mycorrhizal associations

1983 ◽  
Vol 61 (3) ◽  
pp. 917-943 ◽  
Author(s):  
Silvano Scannerini ◽  
Paola Bonfante-Fasolo
Keyword(s):  
Electron Microscopy ◽  
Surface Area ◽  
Ultrastructural Analysis ◽  
Nutrient Transfer ◽  
Cytological Feature ◽  
Symbiotic Interactions ◽  
Mycorrhizal Associations ◽  
Host Pathogen ◽  
Bacterial Associations ◽  
Functional Mechanisms

Electron microscopy is a powerful tool in understanding functional mechanisms in symbiosis (i.e., recognition and transfer of nutrients between partners), but mycorrhizal associations are not yet so well known as host–pathogen and host – mutualistic bacterial associations. However, the study of mycorrhizal ultrastructure has provided some interesting information. In fact unknown symbionts can be recognized with electron microscopy and mycorrhizae can be classified according to a sequence linking intercellular and intracellular interactions between host and fungus. General conclusions can be drawn from this ultrastructural sequence. (i) The most significant cytological feature in mycorrhizae is the presence of an interface through which partners communicate along a vast surface area. This is the key area for symbiotic interactions (both recognition and nutrient transfer) and can vary a great deal mostly in intracellular interactions. (ii) The ultracytochemical aspects of those interfaces, mostly as regards the components of the interfacial matrix, appear quite different from those of host–pathogen associations and suggest a compatibility mechanism. (iii) As regards the transfer of nutrients, even though it has been claimed that transfer of nutrient in all intracellular interactions is achieved by a digestion mechanism of the fungus by the host, available ultrastructural data are not consistent with this hypothesis.

Effect of Synthesis Temperature on Particles Size and Morphology of Zirconium Oxide Nanoparticle

2017 ◽  
Vol 50 ◽  
pp. 18-31 ◽  
Author(s):  
Rudzani Sigwadi ◽  
Simon Dhlamini ◽  
Touhami Mokrani ◽  
Patrick Nonjola
Keyword(s):  
Electron Microscopy ◽  
Particle Size ◽  
Zirconium Oxide ◽  
Thermo Gravimetric Analysis ◽  
Gravimetric Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Crystallite Sizes ◽  
Ft Ir

The paper presents the synthesis and investigation of zirconium oxide (ZrO2) nanoparticles that were synthesised by precipitation method with the effects of the temperatures of reaction on the particles size, morphology, crystallite sizes and stability at high temperature. The reaction temperature effect on the particle size, morphology, crystallite sizes and stabilized a higher temperature (tetragonal and cubic) phases was studied. Thermal decomposition, band structure and functional groups were analyzed by Brunauer-Emmett-Teller (BET), Scanning Electron Microscopy (SEM), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermo-gravimetric analysis (TGA) and Fourier transform infrared (FT-IR). The crystal structure was determined using X-ray diffraction. The morphology and the particle size were studied using (SEM) and (TEM). The shaped particles were confirmed through the SEM analysis. The transmission electron microscopic analysis confirmed the formation of the nanoparticles with the particle size. The FT-IR spectra showed the strong presence of ZrO2 nanoparticles.

Distribution of diaphragmatic lymphatic stomata

1991 ◽  
Vol 70 (4) ◽  
pp. 1544-1549 ◽  
Author(s):  
D. Negrini ◽  
S. Mukenge ◽  
M. Del Fabbro ◽  
C. Gonano ◽  
G. Miserocchi
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Surface Area ◽  
Frequency Distribution ◽  
Maximum Diameter ◽  
Minimum Diameter ◽  
Average Value ◽  
Scanning Electron

In seven anesthetized rabbits we measured the size, shape, and density of lymphatic stomata on the peritoneal and pleural sides of the diaphragm. The diaphragm was fixed in situ and processed for scanning electron microscopy. Results are from 2,902 peritoneal and 3,086 pleural fields (each 1,620 microns 2) randomly chosen from the various specimens. Stomata were seen in 9% of the fields examined, and in 30% of the cases they appeared grouped in clusters with 2-14 stomata/field. Stoma density was 250 +/- 242 and 72 +/- 57 (SD) stomata/mm2 on peritoneal and pleural sides, respectively, and it was similar over the muscular and tendinous portion of the two surfaces. The maximum diameter ranged from less than 1 to approximately 30 microns, with an average value of 1.2 +/- 3.1 micron. The ratio of the maximum to the minimum diameter and the surface area averaged 2 +/- 1.4 and 0.7 +/- 2.4 micron 2, respectively. The maximum and minimum diameter and surface area values followed a lognormal frequency distribution, suggesting that stomata geometry is affected by diaphragmatic tension.

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