Characterization of FeCo based catalyst for ammonia decomposition. The effect of potassium oxide

Abstract FeCo fused catalyst was obtained by fusing iron and cobalt oxides with an addition of calcium, aluminium, and potassium oxides (CaO, Al2O3, K2O). An additional amount of potassium oxide was inserted by wet impregnation. Chemical composition of the prepared catalysts was determined with an aid of the XRF method. On the basis of XRD analysis it was found that cobalt was built into the structure of magnetite and solid solution of CoFe2O4 was formed. An increase in potassium content develops surface area of the reduced form of the catalyst, number of adsorption sites for hydrogen, and the ammonia decomposition rate. The nitriding process of the catalyst slows down the ammonia decomposition.

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Very Fast and Accurate Procedure for the Characterization of Photovoltaic Panels from Datasheet Information

International Journal of Photoenergy ◽

10.1155/2014/946360 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 12

Author(s):

Antonino Laudani ◽

Francesco Riganti Fulginei ◽

Alessandro Salvini ◽

Gabriele Maria Lozito ◽

Salvatore Coco

Keyword(s):

Numerical Methods ◽

Search Space ◽

Extraction Process ◽

Reduced Form ◽

Photovoltaic Panels ◽

Approximation Techniques ◽

Computational Costs ◽

Minimization Technique ◽

Accurate Procedure

In recent years several numerical methods have been proposed to identify the five-parameter model of photovoltaic panels from manufacturer datasheets also by introducing simplification or approximation techniques. In this paper we present a fast and accurate procedure for obtaining the parameters of the five-parameter model by starting from its reduced form. The procedure allows characterizing, in few seconds, thousands of photovoltaic panels present on the standard databases. It introduces and takes advantage of further important mathematical considerations without any model simplifications or data approximations. In particular the five parameters are divided in two groups, independent and dependent parameters, in order to reduce the dimensions of the search space. The partitioning of the parameters provides a strong advantage in terms of convergence, computational costs, and execution time of the present approach. Validations on thousands of photovoltaic panels are presented that show how it is possible to make easy and efficient the extraction process of the five parameters, without taking care of choosing a specific solver algorithm but simply by using any deterministic optimization/minimization technique.

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Characterization and A Preliminary Study of TiO2 Synthesis from Lampung Iron Sand

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.849.113 ◽

2020 ◽

Vol 849 ◽

pp. 113-118

Author(s):

Yayat Iman Supriyatna ◽

Slamet Sumardi ◽

Widi Astuti ◽

Athessia N. Nainggolan ◽

Ajeng W. Ismail ◽

...

Keyword(s):

Food Packaging ◽

Xrd Analysis ◽

Major Elements ◽

Raw Material ◽

Solid Residue ◽

X Ray Diffraction ◽

X Ray ◽

Leaching Solution ◽

Ti Content

The purpose of this study is to characterize Lampung iron sand and to conduct preliminary experiments on the TiO2 synthesis which can be used for the manufacturing of functional food packaging. The iron sand from South Lampung Regency, Lampung Province that will be utilized as raw material. The experiment was initiated by sieving the iron sand on 80, 100, 150, 200 and 325 mesh sieves. Analysis using X-Ray Fluorescence (XRF) to determine the element content and X-Ray Diffraction (XRD) to observe the mineralization of the iron sand was conducted. The experiment was carried out through the stages of leaching, precipitation, and calcination. Roasting was applied firstly by putting the iron sand into the muffle furnace for 5 hours at a temperature of 700°C. Followed by leaching using HCl for 48 hours and heated at 105°C with a stirring speed of 300 rpm. The leaching solution was filtered with filtrate and solid residue as products. The solid residue was then leached using 10% H2O2 solution. The leached filtrate was heated at 105°C for 40 minutes resulting TiO2 precipitates (powder). Further, the powder was calcined and characterized. Characterization of raw material using XRF shows the major elements of Fe, Ti, Mg, Si, Al and Ca. The highest Ti content is found in mesh 200 with 9.6%, while iron content is about 80.7%. While from the XRD analysis, it shows five mineral types namely magnetite (Fe3O4), Rhodonite (Mn, Fe, Mg, Ca) SiO3, Quart (SiO2), Ilmenite (FeOTiO2) and Rutile (TiO2). The preliminary experiment showed that the Ti content in the synthesized TiO2 powder is 21.2%. The purity of TiO2 is low due to the presence of Fe metal which is dissolved during leaching, so that prior to precipitation purification is needed to remove impurities such as iron and other metals.

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Synthesis and Characterization of Lanthanide Metal-Organic Frameworks with Perfluorinated Linkers

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.98.70 ◽

2016 ◽

Vol 98 ◽

pp. 70-74

Author(s):

Andrius Laurikėnas ◽

Jurgis Barkauskas ◽

Aivaras Kareiva

Keyword(s):

Metal Organic Frameworks ◽

Aqueous Media ◽

Xrd Analysis ◽

X Ray Diffraction ◽

Lanthanide Elements ◽

Diffusion Controlled ◽

Benzenedicarboxylic Acid ◽

Metal Organic ◽

Lanthanide Metal

In this study, lanthanide elements (Ln3+) and 2,3,5,6-tetrafluoro-1,4-benzenedicarboxylic acid (TFBDC) based metal-organic frameworks (MOFs) were synthesized by precipitation and diffusion-controlled precipitation methods. Powders insoluble in aqueous media and polar solvents were obtained. The microstructure and properties of Ln3+ MOFs were evaluated and discussed. X-ray diffraction (XRD) analysis, infrared (FTIR) spectroscopy, scanning electron microscopy (SEM) and fluorescence spectroscopy (FLS) were carried out to characterize Ln3+ MOF's crystallinity, the microstructure, chemical composition and optical properties.

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Characterization of Sodium Cobalt Oxides Related to P3-Phase Superconductor

Chemistry of Materials ◽

10.1021/cm047737y ◽

2005 ◽

Vol 17 (8) ◽

pp. 2034-2040 ◽

Cited By ~ 23

Author(s):

Kazunori Takada ◽

Minoru Osada ◽

Fujio Izumi ◽

Hiroya Sakurai ◽

Eiji Takayama-Muromachi ◽

...

Keyword(s):

Cobalt Oxides ◽

Phase Superconductor

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Sonochemically synthetized ZnO-Graphene nanohybrids and its characterization

REVIEWS ON ADVANCED MATERIALS SCIENCE ◽

10.1515/rams-2020-0013 ◽

2020 ◽

Vol 59 (1) ◽

pp. 176-187 ◽

Cited By ~ 2

Author(s):

Cornel Cobianu ◽

Niculae Dumbravescu ◽

Bogdan-Catalin Serban ◽

Octavian Buiu ◽

Cosmin Romanitan ◽

...

Keyword(s):

Thermal Treatment ◽

Ph Value ◽

Raman Band ◽

Xrd Analysis ◽

Sem Analysis ◽

Carbon Incorporation ◽

Additional Amount ◽

Ph Increase ◽

Compositional Properties ◽

Crystalline Symmetry

AbstractThe paper presents the morphological, structural and compositional properties of the sonochemically prepared ZnO-1.4wt% Graphene (Z-G) nanocomposites as a function of pH value of suspension varying from 8.5 to 14 and thermal annealing at 450°C in nitrogen or air ambient. The SEM analysis of the Z-G hybrids dried at 150°C in air has shown a nano-flower like nanostructure for a pH value of 14. The XRD analysis of dried Z-G hybrids revealed a crystallite size increase from 3.5 nm to 18.4 nm with pH increase, and this result was explained in terms of colloids zeta potential evolution with pH value. The Raman and EDS spectroscopy have shown a split of the G band (1575 cm−1) of graphene into two bands (1575 cm−1 and 1605 cm−1), an increased height of D (1323 cm−1) band, and an additional amount of carbon due to CO2 absorption from the air, respectively. The carbon incorporation increased with the decrease of pH, and was associated with a hydrozincite phase, Zn5(CO3)2(OH)6. The formation of dried Z-G nanocomposite was clearly demonstrated only at a pH value equal to 14, where two ZnO Raman active bands at 314.9 cm−1 and 428.2 cm−1 appeared. This result may indicate the sensitivity of the Raman spectroscopy to the nanoflower-like nanostructure of dried Z-G hybrids prepared at pH=14. The thermal treatment of Z-G hybrids in N2at 450°C has increased the number of ZnO Raman bands as a function of pH value, it has decreased the amount of additional carbon by conversion of hydrozincite to ZnO and preserved the graphene profile. The thermal treatment in air at 450°C has increased the crystalline symmetry and stoichiometry of the ZnO as revealed by high and narrow Raman band from 99 cm−1 specific to Zn optical phonons, but it has severely affected the graphene profile in the Z-G hybrid, due to combustion of graphene in oxygen from the ambient.

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Optimization and Characterization of Biogenic Silver Nanoparticles Synthesized by Leaves Extract of Alphonsea Madraspatana

Current Bioactive Compounds ◽

10.2174/1573407217666210223092824 ◽

2021 ◽

Vol 17 ◽

Author(s):

Amita Sahu ◽

Sudhanshu Shekhar Swain ◽

Goutam Ghosh ◽

Deepak Pradhan ◽

Dipak Kumar Sahu ◽

...

Keyword(s):

Silver Nanoparticles ◽

Volume Ratio ◽

Xrd Analysis ◽

Biofilm Inhibition ◽

Nano Silver ◽

E Coli ◽

Biogenic Silver Nanoparticles ◽

Icp Ms ◽

Anti Oxidant

Background: Literature evidences as well as traditional uses of genus Alphonsea reveal significant antimicrobial and anti-oxidant activity, which encourages to consider A. madraspatana to have potent antimicrobials, there by offering potential adjuncts to synthesize improved antimicrobial Silver nanoparticles (AgNPs). The objective of the present exposition is to optimize reaction parameters to synthesize antimicrobial Biogenic Silver nanoparticles (BAgNPs) from extract of A. madraspatana leaves (AML) and to evaluate the effect against bacteria. Methods: BAgNPs was synthesized by optimized reaction. The Synthesized nanoparticles were characterized by UV, IR, ICP-MS and XRD analysis. The antibacterial potency of optimized BAgNPs was evaluated against E. coli by comparing with positive controls. Results: Results of optimization process indicate nanoscale BAgNPs were produced at operating temp. of 45°C for 120 min at pH 8 with 1:5 volume ratio of AgNO3 and extract. Optimized BAgNPs exhibits relatively higher antimicrobial activity (31±1mm) compared to Ciprofloxacin (27±1mm) and marketed nano silver (28± 2 mm). The developed BAgNPs shows comparable biofilm inhibition (86.50%) as compared to marketed nano silver (88.10%) and Ciprofloxacin (83.10%). Conclusion: Experimental evidence suggests methanolic extract of AML under predefined conditions successfully generate nano-template of silver with better antibacterial response against E. coli.

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Sintering of alumina ceramics reinforced with a bioactive glass of 3CaO.P2O5-SiO2-MgO system

Cerâmica ◽

10.1590/0366-69132015613581887 ◽

2015 ◽

Vol 61 (358) ◽

pp. 160-167 ◽

Cited By ~ 1

Author(s):

A. W. Huang ◽

C. Santos ◽

R. O. Magnago ◽

R. F. F. Silva ◽

K. Strecker ◽

...

Keyword(s):

Fracture Toughness ◽

Relative Density ◽

Transient Liquid Phase ◽

Xrd Analysis ◽

Alumina Ceramics ◽

Crystalline Phases ◽

Powder Mixtures ◽

Solid State Sintering ◽

Sintering Condition

Alumina-based ceramics, Al2O3, exhibit a combination of properties which favor its use as biomaterial, specifically as structural dental prosthesis. Its most important properties as biomaterial are its elevated hardness, chemical stability and biocompatibility. Usually, Al2O3 is processed by solid-state sintering at a temperature of about 1600 oC, but it is very difficult to eliminate the porosity due to its diffusional characteristics. The objective of this work was the development and characterization of sintered Al2O3 ceramics, densified with a transient liquid phase formed by a bioactive 3CaO.P2O5-SiO2-MgO glass. Powder mixtures of 90 wt.% Al2O3 and 10 wt.% bioglass were milled, compacted and sintered at 1200 oC to 1450 oC. Comparatively, monolithic Al2O3 samples were sintered at 1600 oC/120 min. The sintered specimens were characterized by relative density, crystalline phases, microstructure and mechanical properties. The results indicate that the specimen sintered at 1450 oC/120 min present the best properties. Under this sintering condition, a relative density of 95% was reached, besides hardness higher than 9 GPa and fracture toughness of 6.2 MPa.m1/2. XRD analysis indicate alumina (αAl2O3), whitlockite (3CaO.P2O5) and diopsite [3(Ca,Mg)O.P2O5], as crystalline phases. Comparatively, monolithic sintered Al2O3 samples presented 92% of relative density with 17.4 GPa and 3.8 MPa.m1/2 of hardness and fracture toughness respectively.

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CHARACTERIZATION OF HYDROXYAPATITE/TI6AL4V COMPOSITE POWDER UNDER VARIOUS SINTERING TEMPERATURE

Jurnal Teknologi ◽

10.11113/jt.v75.5168 ◽

2015 ◽

Vol 75 (7) ◽

Cited By ~ 2

Author(s):

Amir Arifin ◽

Abu Bakar Sulong ◽

Norhamidi Muhamad ◽

Junaidi Syarif

Keyword(s):

Mechanical Properties ◽

Composite Powder ◽

Sintering Temperature ◽

Physical And Mechanical Properties ◽

Xrd Analysis ◽

X Ray Diffraction ◽

Different Temperatures ◽

Two Phases ◽

Work Interaction

Hydroxyapatite (HA) has been widely used in biomedical applications due to its excellent biocompatibility. However, Hydroxyapatite possesses poor mechanical properties and only tolerate limited loads for implants. Titanium is well-known materials applied in implant that has advantage in mechanical properties but poor in biocompatibility. The combination of the Titanium alloy and HA is expected to produce bio-implants with good in term of mechanical properties and biocompatabilty. In this work, interaction and mechanical properties of HA/Ti6Al4V was analyzed. The physical and mechanical properties of HA/Ti6Al4V composite powder obtained from compaction (powder metallurgy) of 60 wt.% Ti6Al4V and 40 wt.% HA and sintering at different temperatures in air were investigated in this study. Interactions of the mixed powders were investigated using X-ray diffraction. The hardness and density of the HA/Ti6Al4V composites were also measured. Based on the results of XRD analysis, the oxidation of Ti began at 700 °C. At 1000 °C, two phases were formed (i.e., TiO2 and CaTiO3). The results showed that the hardness HA/Ti6Al4V composites increased by 221.6% with increasing sintering temperature from 700oC to 1000oC. In contrast, the density of the composites decreased by 1.9% with increasing sintering temperature.

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A Facile Synthesis and Characterization of Highly Crystalline Submicro-Sized BiFeO3

Materials ◽

10.3390/ma13133035 ◽

2020 ◽

Vol 13 (13) ◽

pp. 3035

Author(s):

Dovydas Karoblis ◽

Diana Griesiute ◽

Kestutis Mazeika ◽

Dalis Baltrunas ◽

Dmitry V. Karpinsky ◽

...

Keyword(s):

Bismuth Ferrite ◽

Cost Effective ◽

Xrd Analysis ◽

Synthetic Approach ◽

X Ray Diffraction ◽

Scanning Calorimetry ◽

Dsc Measurements ◽

Optimal Annealing Temperature ◽

Synthesized Materials

In this study, a highly crystalline bismuth ferrite (BFO) powder was synthesized using a novel, very simple, and cost-effective synthetic approach. It was demonstrated that the optimal annealing temperature for the preparation of highly-pure BFO is 650 °C. At lower or higher temperatures, the formation of neighboring crystal phases was observed. The thermal behavior of BFO precursor gel was investigated by thermogravimetric and differential scanning calorimetry (TG-DSC) measurements. X-ray diffraction (XRD) analysis and Mössbauer spectroscopy were employed for the investigation of structural properties. Scanning electron microscopy (SEM) was used to evaluate morphological features of the synthesized materials. The obtained powders were also characterized by magnetization measurements, which showed antiferromagnetic behavior of BFO powders.

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