scholarly journals Experimental Analysis and Characterization of High-Purity Aluminum Nanoparticles (Al-NPs) by Electromagnetic Levitation Gas Condensation (ELGC)

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 2084
Author(s):  
Rana Sabouni Tabari ◽  
Mohammad Halali ◽  
Akbar A. Javadi ◽  
Mohammad Hassan Khanjanpour
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
High Purity ◽  
Gas Flow ◽  
Electromagnetic Levitation ◽  
Aluminum Nanoparticles ◽  
Gas Flow Rate ◽  
X Ray ◽  
Gas Condensation ◽  
High Purity Aluminum

The production of high-purity aluminum nanoparticles (Al-NPs) is challenging due to the highly reactive nature of Al metals. Electromagnetic levitation gas condensation (ELGC) is a promising method to produce high-purity metallic particles as it avoids the interaction between molten metal and refractory-lined, which guarantees the removal of impurities such as oxygen (O). In this research, high-purity Al-NPs were successfully fabricated via ELGC process and fully characterized. The effects of power input and gas flow rate on particle size and distribution were analyzed using field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS), and dynamic light scattering (DLS). The results showed that the Al-NPs have spherical morphologies with an average diameter of 17 nm and size distribution of NPs is narrow under helium (He) flow rate of 15 L/min at a constant temperature of 1683 ± 10 K. The purity of the NPs was confirmed by utilizing X-ray diffraction (XRD), atomic absorption spectroscopy (AAS), and X-ray fluorescence (XRF). Finally, metal purity of 99.976% and 99.97% was measured by AAS and XRF analyses, respectively. Moreover, it was found that increasing gas flow rate and sample temperature results in a decrease in the particle size. The particle sizes for the Al-NPs obtained under He atmosphere were smaller than those obtained under Ar atmosphere.

scholarly journals Effect of operating parameters on production of bio-oil from fast pyrolysis of maize stalk in bubbling fluidized bed reactor

2016 ◽  
Vol 18 (3) ◽  
pp. 88-96 ◽  
Author(s):  
Najaf Ali ◽  
Mahmood Saleem ◽  
Khurram Shahzad ◽  
Sadiq Hussain ◽  
Arshad Chughtai
Keyword(s):  
Particle Size ◽  
Flow Rate ◽  
Gas Flow ◽  
Fast Pyrolysis ◽  
Superficial Velocity ◽  
Operating Parameters ◽  
Gas Flow Rate ◽  
Carrier Gas ◽  
Bio Oil ◽  
Carrier Gas Flow

Abstract The yield and composition of pyrolysis products depend on the characteristics of feed stock and process operating parameters. Effect of particle size, reaction temperature and carrier gas flow rate on the yield of bio-oil from fast pyrolysis of Pakistani maize stalk was investigated. Pyrolysis experiments were performed at temperature range of 360-540°C, feed particle size of 1-2 mm and carrier gas fl ow rate of 7.0-13.0 m3/h (0.61.1 m/s superficial velocity). Bio-oil yield increased with the increase of temperature followed by a decreasing trend. The maximum yield of bio-oil obtained was 42 wt% at a temperature of 490°C with the particle size of around 1.0 mm and carrier gas flow rate of 11.0 m3/h (0.9 m/s superficial velocity). High temperatures resulted in the higher ratios of char and non-condensable gas.

scholarly journals Structural and X-Ray Photoelectron Spectroscopy Study of Al-Doped Zinc-Oxide Thin Films

2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Bong Ju Lee ◽  
Ho Jun Song ◽  
Jin Jeong
Keyword(s):  
Thin Films ◽  
Zinc Oxide ◽  
Flow Rate ◽  
Photoelectron Spectroscopy ◽  
Gas Flow ◽  
Rf Magnetron Sputtering ◽  
Photoelectron Spectra ◽  
Gas Flow Rate ◽  
X Ray ◽  
Oxide Component

Al-doped zinc-oxide (AZO) thin films were prepared by RF magnetron sputtering at different oxygen partial pressures and substrate temperatures. The charge-carrier concentrations in the films decreased from 1.69 × 1021to 6.16 × 1017 cm−3with increased gas flow rate from 7 to 21 sccm. The X-ray diffraction (XRD) patterns show that the (002)/(103) peak-intensity ratio decreased as the gas flow rate increased, which was related to the increase of AZO thin film disorder. X-ray photoelectron spectra (XPS) of the O1s were decomposed into metal oxide component (peak A) and the adsorbed molecular oxygen on thin films (peak B). The area ratio of XPS peaks (A/B) was clearly related to the stoichiometry of AZO films; that is, the higher value of A/B showed the higher stoichiometric properties.

KARAKTERISTIK FISIK NANOKOMPOSIT ZNO/Fe2O3 YANG DIBUAT MENGGUNAKAN FLAME SPRAY PYROLISIS DENGAN VARIASI LAJU ALIR GAS PEMBAWA

EKUILIBIUM ◽  
2011 ◽  
Vol 10 (1) ◽  
Author(s):  
Arif Jumari ◽  
Agus Purwanto ◽  
Sperisa Distantina
Keyword(s):  
Particle Size ◽  
Surface Area ◽  
Flow Rate ◽  
Gas Flow ◽  
Catalytic Performance ◽  
Flame Spray Pyrolysis ◽  
Flame Spray ◽  
Gas Flow Rate ◽  
Carrier Gas ◽  
Carrier Gas Flow

<p><strong><em>Abstract: </em></strong><em>Biodiesel is a very potential alternative energy resources. Producing of Biodiesel was much carried out using homogeneous catalytic esterification of vegetable oil and alcohol. These proces had many disanvantages. ZnO as a transesterification catalyst has given high yield. To improve the catalytic performance, the surface area per mas of catalyst must be increased by decreasing the size of particle. To ease the separation between product and catalyst, the magnetic  behaviour should be added to the catalyst. The aim of the research were to obtain nanocomposite ZnO/Fe<sub>2</sub>O<sub>3</sub> and determine physical characteristic as well as catalytic and separation performance. Nanocomposite ZnO/Fe<sub>2</sub>O<sub>3</sub> was synthesized by flame spray pyrolysis method. Assisted by carrier air precursor solution of Zn(NO<sub>3</sub>)<sub>2</sub> and Fe(NO<sub>3</sub>)<sub>3</sub> was nebulized and flowed to the inner tube of the burner. Nebulasation was carried out by varying carrier gas flow rate but  at constant rateof nebulization. LPG gas dan oxidant air  were flowed to the inner annulus  and outer annulus, respectively. The solid produced was separated from gas by particle filter. The solid particle was then examined by XRD , FE-SEM and BET as wel as catalytic performance. The result showed that the crystalinity of samples decreased by increasing the carrier gas flow rate. The particle size was not influenced by carrier gas flow rate and the size were dominantly between 50-100 nm. A part of particle was flowerlike particle.  The specific surface area  of particle was not inflenced by carrier gas flow rate and its value was 50.5 m<sup>2</sup>/gram.</em></p><p><em> </em><strong><em>Keywords</em></strong><em> : Tran-esterification,  nanocomposite ZnO/Fe<sub>2</sub>O<sub>3</sub>,  flame spray pyrolysis,   carrier gas, particle size,  particle morphology, specific surface area </em></p>

scholarly journals Process Optimization and Upscaling of Spray-Dried Drug-Amino acid Co-Amorphous Formulations

Pharmaceutics ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 24 ◽  
Author(s):  
Georgia Kasten ◽  
Íris Duarte ◽  
Maria Paisana ◽  
Korbinian Löbmann ◽  
Thomas Rades ◽  
...  
Keyword(s):  
Particle Size ◽  
Bulk Density ◽  
Spray Drying ◽  
Flow Rate ◽  
Gas Flow ◽  
Pilot Scale ◽  
High Yield ◽  
Outlet Temperature ◽  
Gas Flow Rate ◽  
Drying Chamber

The feasibility of upscaling the formulation of co-amorphous indomethacin-lysine from lab-scale to pilot-scale spray drying was investigated. A 22 full factorial design of experiments (DoE) was employed at lab scale. The atomization gas flow rate (Fatom, from 0.5 to 1.4 kg/h) and outlet temperature (Tout, from 55 to 75 °C) were chosen as the critical process parameters. The obtained amorphization, glass transition temperature, bulk density, yield, and particle size distribution were chosen as the critical quality attributes. In general, the model showed low Fatom and high Tout to be beneficial for the desired product characteristics (a co-amorphous formulation with a low bulk density, high yield, and small particle size). In addition, only a low Fatom and high Tout led to the desired complete co-amorphization, while a minor residual crystallinity was observed with the other combinations of Fatom and Tout. Finally, upscaling to a pilot scale spray dryer was carried out based on the DoE results; however, the drying gas flow rate and the feed flow rate were adjusted to account for the different drying chamber geometries. An increased likelihood to achieve complete amorphization, because of the extended drying chamber, and hence an increased residence time of the droplets in the drying gas, was found in the pilot scale, confirming the feasibility of upscaling spray drying as a production technique for co-amorphous systems.

Study on the Kinetics of Chemical Looping Combustion of Copper-Based Oxygen Carrier

2013 ◽  
Vol 724-725 ◽  
pp. 1140-1144
Author(s):  
Yong Qiang Liu ◽  
Zhi Qi Wang ◽  
Jing Li Wu ◽  
Jin Hu Wu
Keyword(s):  
Particle Size ◽  
Reaction Temperature ◽  
Flow Rate ◽  
Conversion Rate ◽  
Gas Flow ◽  
Oxygen Carrier ◽  
Combustion Process ◽  
Chemical Looping Combustion ◽  
Chemical Looping ◽  
Gas Flow Rate

Kinetics is the study of rates of chemical processes, which includes investigations of how different experimental conditions can influence the speed of a chemical reaction and the reactions mechanism. In this paper, the influences of several parameters including particle size and mass of copper-based oxygen carrier, reaction gas flow rate and temperature on the conversion rate of oxygen carrier in chemical looping combustion was investigated. The results of experiment reveal that the conversion rate of oxygen carrier is influenced by the reaction temperature, mass of the oxygen carrier and the reaction gas flow rate. The conversion rate of oxygen carrier is improved with decreasing the mass of the oxygen carrier and increasing the reaction gas flow rate within a certain extent in the chemical looping combustion process. The particle size has very little effect on the conversion rate, and 800 °C is an advisable reaction temperature for chemical looping combustion process of copper-based oxygen carrier with methane and air.

Morphological and optical properties of graphene film synthesized from waste of industrial cooking oil, AYAMAS using DTCVD method

2020 ◽  
Vol 14 (2) ◽  
pp. 24
Author(s):  
Nurfazianawatie Mohd Zin
Keyword(s):  
Optical Properties ◽  
Flow Rate ◽  
Gas Flow ◽  
Graphene Film ◽  
Nickel Surface ◽  
Gas Flow Rate ◽  
Argon Gas ◽  
X Ray ◽  
Cooking Oil ◽  
Vis Spectroscopy

The synthesis of graphene by double thermal chemical vapor deposition (DTCVD) using waste of industrial cooking oil (WICO) as a natural carbon source was investigated. The synthesis parameter (Argon gas flow rate) was varied between 50sccm to 300sccm by 50sccm increments. The function of Argon gas is to provide ambient condition, remove the atmospheric air from the tube and could improve the crystallinity of graphene during synthesis. WICO (from AYAMAS food processing) was placed in the first furnace (precursor furnace) and nickel was placed in the second furnace (deposition furnace). During the synthesis, elevated quantities of carbon from the source material are separated and precipitated on the Nickel surface. The sample were characterized by using Field Emission Scanning Electron Microscopy (FESEM), X-Ray Diffraction (XRD), Energy Dispersive X-ray (EDX), and Ultraviolet Visible (UV-Vis) spectroscopy. Based on FESEM images, at 250sccm, hexagonal graphene formation was observed. Besides, optical properties can be seen by UV-Vis and as the results show that 250sccm is the highest reflectivity value. Consequently, graphene synthesis from WICO using various Argon gas flow rate as precursor is successfully demonstrated.

Production of Size-Selected CuXSn1-X Nanoclusters

2011 ◽  
Vol 295-297 ◽  
pp. 70-73 ◽  
Author(s):  
Ahmad I. Ayesh ◽  
Naser Qamhieh ◽  
Saleh Thaker Mahmoud ◽  
Hussain Alawadhi
Keyword(s):  
Flow Rate ◽  
Gas Flow ◽  
Discharge Power ◽  
Inert Gas ◽  
Gas Flow Rate ◽  
Quadrupole Mass ◽  
Gas Condensation ◽  
Operation Conditions ◽  
Source Operation ◽  
Production Mechanisms

Composites of copper–tin (CuxSn1-x) nanoclusters were synthesized using the magnetron dc sputtering gas–condensation technique. Targets with controlled ratios of Sn to Cu were used to produce CuxSn1-xwith different compositions. The effects on the nanocluster size and yield of the sputtering discharge power, inert gas flow rate, and aggregation length were investigated using a quadrupole mass filter. The sputtering discharge power was optimized to maximize the nanocluster yield. The results show that as the inert gas flow rate increases the nanocluster size increases and then decreases. These dependences could be understood in terms of the dominant nanocluster production mechanisms. This work demonstrates the ability of controlling the CuxSn1-xnanoclusters’ size and composition by optimizing the source operation conditions.

High Purity Magnetite Microparticles Directly Derived from Mill Scale via Hydrogen-Reduction Method

2021 ◽  
Vol 1016 ◽  
pp. 286-291
Author(s):  
Autchariya Boontanom ◽  
Piyada Suwanpinij
Keyword(s):  
Flow Rate ◽  
High Purity ◽  
Gas Flow ◽  
Reduction Method ◽  
Hydrogen Reduction ◽  
Reduction Temperature ◽  
Mixed Gas ◽  
Mill Scale ◽  
X Ray ◽  
Ar Gas

This study develops a fast and simple way to produce high purity magnetite (Fe3O4) microparticles from mill scale by using hydrogen reduction with the addition of vapour as a retarding agent. By optimising the reduction temperature and gas flow rate, the characterisations by X-ray diffractometry technique shown that the Fe3O4 fraction of over 93 wt.-% is shown at the reduction temperature of 550 – 650 oC with the flow rate of the 4.5-5.5 mol%H2 + Ar gas + H2O gas mixture from 100 – 200 ml/min. The highest Fe3O4 fraction of over 99 wt.-% can be achieved from the reduction with the mixed gas at 650 oC and the flow rate of 200 ml/min for 4 hour.

Inhibition Mechanism of Magnesium Ion on Carbonation Reaction with Ca(OH)2 and CO2

2006 ◽  
Vol 510-511 ◽  
pp. 990-993 ◽  
Author(s):  
Jeong Hwan Kim ◽  
Ji Whan Ahn ◽  
Sang Jin Ko ◽  
Woon Kyoung Park ◽  
Choon Han
Keyword(s):  
Particle Size ◽  
Aspect Ratio ◽  
Flow Rate ◽  
Gas Flow ◽  
Inhibition Mechanism ◽  
Gas Flow Rate ◽  
High Concentration ◽  
Precipitated Calcium Carbonate ◽  
Carbonation Reaction ◽  
Co2 Gas

The objective of this study is to synthesize the single phase aragonite precipitated calcium carbonate by the carbonation process in the Ca(OH)2-MgCl2-CO2 system. Many researchers reported the influence of Mg2+ ion on the synthetic properties. The inhibition of calcite nucleation and crystal growth, distortion of calcite lattice, and change of surface electrification were investigated. Variety of particle size and aspect ratio were observed according to changes in the concentration of Ca(OH)2 slurry, temperature, and CO2 gas flow rate. The nucleation rate increased when decreasing the temperature and increasing the CO2 gas flow rate. Particle size and aspect ratio increased at high temperature, low CO2 gas flow rate, and high concentration of Ca(OH)2 slurry, however small-sized aragonite was obtained at low temperature.

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