Concentration limits of combustion in rich hydrogen–air mixtures in the presence of inhibitors

2010 ◽  
Vol 20 (5) ◽  
pp. 296-298 ◽  
Author(s):  
Nikolai M. Rubtsov ◽  
Boris S. Seplyarskii
Keyword(s):  
Concentration Limits

scholarly journals Tannin-Mordant Coloration with Matcha (camelia sinensis) and Iron(II)-Lactate on Human Hair Tresses

Molecules ◽  
2021 ◽  
Vol 26 (4) ◽  
pp. 829
Author(s):  
Lusine Sargsyan ◽  
Thomas Hippe ◽  
Hartmut Manneck ◽  
Volkmar Vill
Keyword(s):  
Human Hair ◽  
Cysteic Acid ◽  
Damage Potential ◽  
Natural Hair ◽  
Wash Fastness ◽  
Dyeing Method ◽  
Mordant Dyeing ◽  
Concentration Limits

The aim of this work was to optimize our natural hair dyeing system which we described in our previous work and to compare with other dyeing systems. Therefore, we investigated concentration limits of matcha and mordant and compared this new dyeing method with commercial permanent systems on the market. Completely unpigmented hair tresses were dyed with matcha powder (camelia sinensis) and iron(II)-lactate. To investigate the wash fastness and concentration limits, the differently dyed hair tresses were spectrophotometrically measured. The comparison of the damage potential for which cysteic acid is an indicator was measured by NIR. The concentration of matcha and mordant are responsible for the intensity of the color results. The higher the matcha or the mordant concentration, the darker the color results of the dyed hair tresses. Hair damage of matcha mordant dyeing is comparable with results of commercial permanent hair coloration systems. Moreover, the results of wash fastness of matcha mordant dyed hair tresses is comparable and even better by tendency to permanent colored hair tresses.

Measuring Marine Iron(III) Complexes by CLE-AdSV

2005 ◽  
Vol 2 (2) ◽  
pp. 80 ◽  
Author(s):  
Raewyn M. Town ◽  
Herman P. van Leeuwen
Keyword(s):  
Ligand Exchange ◽  
Essential Element ◽  
Stripping Voltammetry ◽  
Chemical Form ◽  
Kinetic Properties ◽  
Marine Systems ◽  
Dissolved Ions ◽  
Competitive Ligand Exchange ◽  
Concentration Limits ◽  
Kinetic Features

Environmental Context. Iron is an essential element for life in the world's oceans, and in some regions its concentration limits the growth of phytoplankton. The amount of iron(iii) which is available to an organism depends on the exact chemical form in which it exists, for example as dissolved ions or associated with organic compounds. There are widespread reports that marine iron(iii) is predominantly bound in extremely strong complexes. We show that such claims might be the result of an artefact of the measurement technique, CLE-AdSV. Ensuing ideas about the iron biogeochemistry in marine systems might require reconsideration as well. Abstract. Iron(iii) speciation data, as determined by competitive ligand exchange?adsorptive stripping voltammetry (CLE-AdSV), is reconsidered in the light of the kinetic features of the measurement. The very large stability constants reported for iron(iii) in marine ecosystems are shown to be possibly due to an artefact of the technique, arising from the assumption that equilibrium is achieved between all iron(iii) species of relevance. Particular kinetic properties, related to the special nature of hydroxide as a metal complexant, have the consequence that CLE-AdSV measurements of iron(iii) in seawater generally correspond to the hydroxide complexes only. By the same token, dissolved hydroxide complexes are the key components of the bioavailable iron(iii) pool. The analysis presented herein opens opportunities to exploit CLE-AdSV for more rigorous investigation of the links between the speciation and the bioavailability of iron(iii).

Optimal use of chlorine in water distribution networks based on specific locations of booster chlorination: analyzing conditions in Mexico

2015 ◽  
Vol 16 (2) ◽  
pp. 493-505 ◽  
Author(s):  
Daniel Hernández Cervantes ◽  
Jesús Mora Rodríguez ◽  
Xitlali Delgado Galván ◽  
Josefina Ortiz Medel ◽  
Martín Rubén Jiménez Magaña
Keyword(s):  
Water Treatment ◽  
Water Distribution ◽  
Treatment Plant ◽  
Drinking Water Treatment ◽  
Water Treatment Plant ◽  
Distribution Networks ◽  
Water Distribution Networks ◽  
Booster Chlorination ◽  
The Cost ◽  
Concentration Limits

Water distribution networks (WDNs) could present problems of pathogen intrusion that affect the health of consumers. One solution to diminish this risk is to add more disinfectant to the water at the drinking water treatment plant (DWTP). However, this increases the cost of water treatment and may also cause the formation of trihalomethanes. Mexico has the largest bottled water market in the world. Also, most houses are built with individual storage containers due to intermittent service, which generates a greater residence time of the water before use. This paper shows an alternative to guarantee minimum disinfection along WDNs and diminish the use of disinfectant at the DWTP considering the conditions of water consumption and use in Mexico. We propose a model based on Genetic Algorithms to obtain scenarios where free chlorine is maintained at the minimum permissible concentration throughout the day. In addition, Water Managers could optimize the use of disinfectant by implementing booster chlorination stations (BCSs). The results show that chlorine use could be reduced by 38%, therefore guaranteeing the chlorine concentration limits along the WDN.

Extending the SHS combustion concentration limits in Ti + C + Fe powder mixtures by preliminary mechanical activation

2020 ◽  
Vol 25 ◽  
pp. 458-460
Author(s):  
A.V. Baranovskiy ◽  
G.A. Pribytkov ◽  
M.G. Krinitcyn ◽  
V.V. Homyakov ◽  
G.O. Dankovcev
Keyword(s):  
Mechanical Activation ◽  
Powder Mixtures ◽  
Preliminary Mechanical Activation ◽  
Concentration Limits

scholarly journals Self-Propagating High-Temperature Synthesis under the Conditions of Rotation and Characteristic Heat and Concentration Limits on the Example of Oxide Systems

2011 ◽  
Vol 13 (3-4) ◽  
pp. 149
Author(s):  
Georgij I. Ksandopulo
Keyword(s):  
High Temperature ◽  
Combustion Front ◽  
Temperature Synthesis ◽  
Oxide Systems ◽  
High Temperature Synthesis ◽  
Adiabatic Regime ◽  
Continuous Technology ◽  
Technology Of Production ◽  
Concentration Limits ◽  
Melted Metal

Potential economic possibility of using centrifugal force for production of noble ferroalloys is shown. Connected with this process, the limits of stable combustion are conditioned by formation of adiabatic regime of combustion due to the effect of acceleration of the combustion front by centrifuged particles of melted metal product. There appears the possibility to create a continuous technology of production of ferroalloys on the basis of aluminothermy and of significantly decreased low limit concentration of the sought for metal in the initial row material.

scholarly journals The influence of soil microorganisms on heavy metal content in the substrate of waste rock dumps

2021 ◽  
Vol 31 ◽  
pp. 00017
Author(s):  
Natalia Makeeva ◽  
Olga Neverova
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Content ◽  
Soil Microorganisms ◽  
Accumulation Rate ◽  
Heavy Metal Content ◽  
Waste Rock ◽  
Soil Reclamation ◽  
The Impact ◽  
Concentration Limits

The environmental effects of mining and its impact on natural resources are of a holistic nature. One of the modern methods employed for the remediation of technogenically disturbed soils is the application of microorganisms. This paper studies the impact made by soil microorganisms on the accumulation rate of heavy metals in the substrate of waste rock dumps in the process of soil reclamation. Suspensions of soil microorganisms (microorganisms utilising mineral nitrogen forms / MUMN; microorganisms decomposing silicates / MDS; microscopic fungi / MF) were applied to the rock dump surface. Separate groups as well as their combinations were applied. The heavy metal content analysis did not indicate a significant exceedance of the maximum allowable concentration limits (MACL) in the soil of the waste rock. The only metal whose content exceeded the maximum admissible concentration limits was nickel. It has found that the application of microorganisms influences the concentration of several heavy metals due to pH level changes of the rock dump soil.

Calculating the concentration limits of flame propagation in vapor-air mixtures

2008 ◽  
Vol 51 (6) ◽  
pp. 228-229
Author(s):  
N. I. Akinin ◽  
I. V. Babaitsev ◽  
N. N. Bulkhov ◽  
N. A. Smirnova
Keyword(s):  
Flame Propagation ◽  
Concentration Limits

Distinct particle modes in the lower stratosphere constrain secondary aerosol chemistry and gas-phase concentrations

2021 ◽  
Author(s):  
Daniel Murphy ◽  
Karl Froyd ◽  
Greg Schill ◽  
Charles Brock ◽  
Agnieszka Kupc ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Gas Phase ◽  
Lower Stratosphere ◽  
Aerosol Particles ◽  
Organic Content ◽  
Aerosol Chemistry ◽  
Volatile Organics ◽  
Organic Sulfate ◽  
Concentration Limits ◽  
Distinct Particle

<p>There are distinct types of aerosol particles in the lower stratosphere. Stratospheric sulfuric acid particles with and without meteoric metals coexist with mixed organic-sulfate particles that originated in the troposphere. That these particles remain distinct has important implications for aerosol chemistry and the concentrations of several gas-phase species. Neither semi-volatile organics nor ammonia can be in equilibrium with the gas phase. The gas-phase concentrations of semi-volatile organics and ammonia must be very low, or else the sulfuric acid particles would not stay so pure. The upper concentration limits are around a pptv. Yet the sulfuric acid particles in the Northern Hemisphere show a very small but measurable uptake of organics and ammonia, indicating non-zero gas-phase concentrations of those species. Finally, the organic-sulfate particles must be resistant to photochemical loss, or else they would no longer retain their organic content.</p>

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