scholarly journals The Effect of Humidity on the Atomization Process and Structure of Nanopowder Designed for Extinguishment

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3329
Author(s):  
Mateusz Biel ◽  
Piotr Izak ◽  
Krystian Skubacz ◽  
Agata Stempkowska ◽  
Joanna Mastalska-Popławska
Keyword(s):  
Particle Size ◽  
Free Radicals ◽  
Nano Particles ◽  
Combustion Mechanism ◽  
Water Molecules ◽  
Characteristic Parameters ◽  
Atomization Process ◽  
Environmental Humidity ◽  
Grain Distribution ◽  
Greenhouse Effects

Increasingly, firefighting aerosols are being used to extinguish fires. It is assumed that the extinguishing mechanism involves breaking the chain of physicochemical reactions occurring during combustion by binding free radicals at ignition. The radicals are most likely formed from the transformation of water molecules, with the active surfaces of aerosol micro- or even nanoparticles. The aerosol extinguishing method is very effective even though it does not reduce oxygen levels in the air. In contrast to typical extinguishing powders, the aerosol leaves a trace amount of pollutants and, above all, does not adversely affect the environment by depleting the ozone layer and increasing greenhouse effects. Depending on how the firefighting generators are released, the aerosol can act locally or volumetrically, but depending on environmental conditions, its effectiveness can be variable. The article presents the influence of environmental humidity on the atomization of aerosol nanosize, which confirms the radical combustion mechanism. This paper presents the effect of environmental humidity on the atomization of aerosol superfine (nano) particles. The main focus was on the grain distribution and its effect on the surface activity of the FP-40C type firefighting aerosol. Changes in the characteristic parameters of the particle size distribution of RRSB (Rosin-Rammler-Sperling-Bennet) are presented.

SCREENING OF BIODEGRADABLE POLYMER AND MOST EFFECTIVE VARIABLES IN PREPARATION OF ESSENTIAL OIL LOADED NANO PARTICLES FOR PULMONARY DELIVERY USING TAGUCHI DESIGN

INDIAN DRUGS ◽  
2021 ◽  
Vol 58 (02) ◽  
pp. 68-75
Author(s):  
Avani Khristi ◽  
Lalit L. Jha ◽  
Abhay Dharamsi ◽  
Keyword(s):  
Particle Size ◽  
Essential Oil ◽  
Biodegradable Polymers ◽  
Drug Loading ◽  
Pulmonary Inflammation ◽  
Pulmonary Delivery ◽  
Entrapment Efficiency ◽  
Nano Particles ◽  
Favorable Conditions ◽  
Insoluble Polymers

The biodegradability of inhalable nanoparticles (NPs) is an important criterion in prevention of lung toxicity due to NPs which have been taken to cure the condition. Pulmonary inflammation may result due to non-biodegradation or insoluble polymers used to produce NPs. Biodegradable polymers are widely used for manufacturing safe drug-entrapped inhalable NPs for pulmonary delivery. Here in this study, for preparing ajwain essential oil loaded NPs for pulmonary delivery, biodegradable polymers chitosan, gelatin and alginic acid have been evaluated for suitability. Based on the results of trial batches prepared from each polymer, the responses particle size and entrapment efficiency were measured and compared. Out of the three polymers, chitosan was having very good entrapment efficiency, poly dispersive index, drug loading and zeta potential-favorable conditions for pulmonary delivery of essential oils. Further screening of most effective variables in manufacturing nano particles using chitosan, eight batches of nano particles have been prepared as per taguchi orthogonal 2 level array L8 experimental design (Design expert software, version 7.0) where two responses, particle size and entrapment efficiency, have been observed. Based on the results of eight batches, standard effects have been calculated and significant variables identified, for both particle size and entrapment efficiency, for further optimization under design of experiment.

Stream-bed armouring under known conditions of upstream sediment input

1984 ◽  
Vol 21 (9) ◽  
pp. 1061-1066 ◽  
Author(s):  
Eric J. Schiller ◽  
A. Charles Rowney
Keyword(s):  
Particle Size ◽  
Sediment Load ◽  
Experimental Tests ◽  
Direct Influence ◽  
Sediment Sources ◽  
Characteristic Parameters ◽  
Bed Forms ◽  
Sediment Input ◽  
Bed Material ◽  
Stream Bed

Experiments were conducted to assess ways in which an imposed sediment load can affect the formation and final nature of an armoured bed. A flume loaded with a quartz aggregate of known composition was subjected to various sediment-laden flows of water to produce armoured beds. Characteristic parameters of the armoured beds were then compared.In general, it was found that the final armoured bed can be significantly altered by an imposed sediment load. As the size of the input sediment increased, the amount of bed material that was eroded, the resulting particle size of the bed, and the total roughness of the bed all decreased. The formation of bed forms was very important in this process. The trends observed in these experimental tests indicate that the presence or absence of upstream sediment sources has a direct influence on the resulting armoured layer.

scholarly journals Effect of Nanosized Colloidal Copper on Cotton Fabric

2010 ◽  
Vol 5 (3) ◽  
pp. 155892501000500 ◽  
Author(s):  
D.P. Chattopadhyay ◽  
B.H. Patel
Keyword(s):  
Particle Size ◽  
Cotton Fabric ◽  
Colloidal Solution ◽  
Chemical Reduction ◽  
Average Particle Size ◽  
Particle Size Analysis ◽  
Nano Particles ◽  
Size Analysis ◽  
Average Particle ◽  
Sem Images

This research deals with the synthesis of nanosized copper as colloidal solution and its application to cotton fabric. Copper nano colloids were prepared by chemical reduction of copper salt using sodium borohydride as reducing agent in presence of tri-sodium citrate. The size and size distribution of the particles were examined by particle size analyzer and the morphology of the synthesized particles was examined by SEM and AFM techniques. X-ray fluorescence spectroscopy detected the presence of copper in the treated fabric. The results of particle size analysis showed that the average particle size varied from 60 nm to 100 nm. The nano copper treated cotton was subjected to soil burial test for the assessment of its resistance towards microbial attack. SEM images of treated fabric indicate copper nano particles are well dispersed on the surface of the specimens. The treatments of nano copper colloidal solution on cotton not only improve its antimicrobial efficiency but also influenced the tensile strength of the fabric sample positively. The treatment was found to enhance the color depth and fastness properties of direct dyed cotton fabric samples.

Particle-size and morphology dependence of the preferred interface orientation in LiFePO4 nano-particles

2014 ◽  
Vol 2 (37) ◽  
pp. 15437-15447 ◽  
Author(s):  
Aziz Abdellahi ◽  
Oncu Akyildiz ◽  
Rahul Malik ◽  
Katsuyo Thornton ◽  
Gerbrand Ceder
Keyword(s):  
Particle Size ◽  
First Principles ◽  
Nano Particles ◽  
Particle Size And Morphology ◽  
Interface Orientation ◽  
Size And Morphology

Using calculations based on first principles, we demonstrate that the preferred interface in singles LiFePO4 particles depends both on the particle size and morphology.

Performance Profiling of Nanoparticulate Graphite Powder as Lubricant in the Machining of AISI 1040 Steel under Variable Machining Conditions

2014 ◽  
Vol 984-985 ◽  
pp. 15-24 ◽  
Author(s):  
S. Srikiran ◽  
K. Ramji ◽  
B. Satyanarayana
Keyword(s):  
Particle Size ◽  
Surface Finish ◽  
Cutting Forces ◽  
Solid Lubricant ◽  
Graphite Powder ◽  
Nano Particles ◽  
Chemical Degradation ◽  
Work Piece ◽  
Tool Temperature ◽  
Cutting Zone

The generation of heat during machining at the cutting zone adversely affects the surface finish and tool life. The heat at the cutting zone, which plays a negative role due to poor thermal conductivity, resistance to wear, high strength at high temperatures and chemical degradation can be overcome by the use of proper lubrication. Advancements in the field of tribology have led to the use of solid lubricants replacing the conventional flood coolants. This work involves the use of nanoparticulate graphite powder as a lubricant in turning operations whose performance is judged in terms of cutting forces, tool temperature and surface finish of the work piece. The experimentation revealed the increase in cutting forces and the tool temperature when the solid lubricant used is decreased in particle size. The surface finish deteriorated with the decrease in particle size of the lubricant in the nanoregime.Keywords-Turning, Solid lubricant, Graphite, Minimum Quantity Lubrication, nano–particles,Weight percentage,Frictioncoefficient.

Synthesis of Self-Assembly Au Nano-Particles Based on Sodium Citrate-Tannin Reduction Method

2011 ◽  
Vol 311-313 ◽  
pp. 461-465
Author(s):  
Dau Chung Wang ◽  
Shinn Hwa Chen ◽  
Gen You Chen ◽  
Ken Yen Chen ◽  
Cheng Hsien Tsai
Keyword(s):  
Particle Size ◽  
Self Assembly ◽  
Reduction Method ◽  
Low Cost ◽  
Trisodium Citrate ◽  
Nano Particles ◽  
Size Dependent ◽  
Biological Toxicity ◽  
The One ◽  
Au Nano Particles

Recently, self-assembly synthesis of metal nano-particles has attracted great interest due to its unique size dependent properties. In this study, an easy synthesis would be developed to form Au nano-particles which are without toxicity. The Au particles could be applied in biological and biological toxicity experiments. Some phenomena could be discovered in this paper. First, the concentration ratio of Au and trisodium citrate would be adjusted to control the Au nano-particles size. And the particle size is limited because of the size dependent energy would be discovered in this paper. The minimum particle size is also found. The one phase liquid reduction method is easy and without toxicity, it is low-cost, high-throughput, and suitable to be applied in biological and biological toxicity studies.

scholarly journals TiO2 (Nano)Particles Extracted from Sugar-Coated Confectionery

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Martina Lorenzetti ◽  
Anja Drame ◽  
Sašo Šturm ◽  
Saša Novak
Keyword(s):  
Particle Size ◽  
Extraction Methods ◽  
Food Additive ◽  
Nano Particles ◽  
Chewing Gum ◽  
Biologically Relevant ◽  
Whitening Agent ◽  
Colloidal Properties ◽  
Particle Population ◽  
Particle Extraction

As the debate about TiO2 food additive safety is still open, the present study focuses on the extraction and characterisation of TiO2 (nano)particles added as a whitening agent to confectionary products, that is, chewing gum pellets. The aim was to (1) determine the colloidal properties of suspensions mutually containing TiO2 and all other chewing gum ingredients in biologically relevant media (preingestion conditions); (2) characterise the TiO2 (nano)particles extracted from the chewing gum coating (after ingestion); and (3) verify their potential photocatalysis. The particle size distribution, in agreement with the zeta potential results, indicated that a small but significant portion of the particle population retained mean dimensions close to the nanosize range, even in conditions of moderate stability, and in presence of all other ingredients. The dispersibility was enhanced by proteins (i.e., albumin), which acted as surfactants and reduced particle size. The particle extraction methods involved conventional techniques and no harmful chemicals. The presence of TiO2 particles embedded in the sugar-based coating was confirmed, including 17–30% fraction in the nanorange (<100 nm). The decomposition of organics under UV irradiation proved the photocatalytic activity of the extracted (nano)particles. Surprisingly, photocatalysis occurred even in presence of an amorphous SiO2 layer surrounding the TiO2 particles.

Study of Au-CeO2 Nano-particles using analytical Transmission Electron Microscopy

2007 ◽  
Vol 1 (1) ◽  
Author(s):  
P. Gu ◽  
G. Yang ◽  
R.F. Klie
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Particle Size ◽  
Rare Earth ◽  
Lattice Parameter ◽  
Nano Particles ◽  
Rare Earth Doping ◽  
Analytical Transmission Electron Microscopy ◽  
Transmission Electron ◽  
Shift Reaction

Cerium oxide doped with various rare earth metals is often used as a support for nano-sized gold particles, and demonstrates to be a promising catalyst for the water gas shift reaction at low temperatures. Many factors are hypothesized to affect the activity of this heterogeneous catalyst, including its loading with gold, the rare-earth dopant, the support and Au particle size, and leaching of the sample. In this study, we examined several Au/CeO2-based catalyst samples, including 2.4% Au/(Ce,Gd)O2, 1.8% Au/(Ce,La)O2 leached, 0.5% Au/(Ce,Gd)O2 leached, and 0.75% Au/CeO2 utilizing analytical transmission electron microscopy. The effects of Au and rare-earth doping on the ceria lattice parameter were investigated, and it was determined that there are no significant variations in the particle's structure or lattice-spacing. Furthermore, the particle sizes of each of the four samples were investigated concluding that although the 1.8% Au/(Ce,La)O2 leached sample has a slightly larger particle size, and the 2.4% Au/(Ce,Gd)O2 sample has a slightly smaller particle size, the differentiation is not adequate to be accountable for the radical distinction in catalytic activity.

Sign in / Sign up

Export Citation Format

Share Document