mixture concentration
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Toxics ◽  
2021 ◽  
Vol 9 (8) ◽  
pp. 174
Author(s):  
Shannon Weeks Santos ◽  
Jérôme Cachot ◽  
Bettie Cormier ◽  
Nicolas Mazzella ◽  
Pierre-Yves Gourves ◽  
...  

The aim of this study was to analyze the impact of three concentrations of a pesticide mixture on the first development stages of rainbow trout (Oncorhynchus mykiss). The mixture was made up of three commonly used pesticides in viticulture: glyphosate (GLY), chlorpyrifos (CPF) and copper sulfate (Cu). Eyed stage embryos were exposed for 3 weeks to three concentrations of the pesticide mixture. Lethal and sub-lethal effects were assessed through a number of phenotypic and molecular endpoints including survival, hatching delay, hatching success, biometry, swimming activity, DNA damage (Comet assay), lipid peroxidation (TBARS), protein carbonyl content and gene expression. Ten target genes involved in antioxidant defenses, DNA repair, mitochondrial metabolism and apoptosis were analyzed using real-time RT-qPCR. No significant increase of mortality, half-hatch, growth defects, TBARS and protein carbonyl contents were observed whatever the pesticide mixture concentration. In contrast, DNA damage and swimming activity were significantly more elevated at the highest pesticide mixture concentration. Gene transcription was up-regulated for genes involved in detoxification (gst and mt1), DNA repair (ogg1), mitochondrial metabolism (cox1 and 12S), and cholinergic system (ache). This study highlighted the induction of adaptive molecular and behavioral responses of rainbow trout larvae when exposed to environmentally realistic concentrations of a mixture of pesticides.


2021 ◽  
Vol 18 (2) ◽  
pp. 56-59
Author(s):  
R.K. Manatbayev ◽  

This work describes the appearance of a concentration polarizing boundary layer on the membrane surface during the separation of the H2/CO2 gas mixture. Concentration polarization occurs when the rejection solution accumulates near the surface of the membrane, forming a boundary layer. The inclusion of concentration polarization effects in the processing of porous walls creates additional difficulties. The boundary layer formed by concentration polarization can be considered as a type of a second porous wall with a lower permeability than the membrane. The main difficulty in modeling this situation is to determine the appropriate boundary conditions for the concentration on the wall, since the concentrations on the wall will constantly change, and the wall geometry itself may change over time due to particle deposition. To account for this effect, a numerical approach was developed, which is discussed in this work


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
An Lu ◽  
Chunhua Zhang ◽  
Peng Ji ◽  
Yangyang Li

AbstractThe experiments were conducted on a modified two-cylinder diesel engine to investigate the effects of excess-air coefficient (λ) and intake temperature (Tin) of different blending ratios (volume ratio of gasoline in the blends) on the combustion and emission characteristics of a Partially Premixed Compression Ignition (PPCI) engine. The results show that with the increase of gasoline blending ratio, the peak in-cylinder pressure (Pmax), the peak in-cylinder temperature (Tmax) and the peak heat release rate (HRRmax) of four test fuels all increase first and then decrease. When gasoline volume fraction is 10%, HC and CO emissions are the lowest. In addition, intake temperature (Tin) has a significant effect on the n-butanol/gasoline PPCI engine. With the increase of Tin, the in-cylinder Pmax and HRRmax of four test fuels gradually increase, the combustion phase advances and HC and CO emissions decrease, while NOx emissions increase slightly. Furthermore, as λ increases, the Pmax, Tmax and HRRmax of the four test fuels show monotonously reducing trend. At the same time, mixture concentration has basically no effect on start of combustion (CA10), the combustion duration (CD) gradually extends, and HC and CO emissions increase.


2021 ◽  
Vol 264 ◽  
pp. 04011
Author(s):  
Rafik Matchanov ◽  
Anvar Rizaev ◽  
A Yuldashev ◽  
Davronbek Kuldoshev ◽  
M Mirzaeva

The article presents the methods for calculating the pressure loss of the pneumatic transport system of a cotton harvester related to the power consumption of the fan drive. Mathematical models for computer calculation are presented. Numerical studies of the influence of the pipeline diameter and the air mixture composition on the power consumption of the fan drive are presented. It was determined that with an increase in the diameter of the pipeline from 0.15 m to 0.175 m and a change in the mixture concentration μ = 0.228 ÷ 0.338 for a serial receiving chamber, the fan drive power decreases from 10.3 kW to 5.79 kW.


2021 ◽  
Vol 249 ◽  
pp. 03011
Author(s):  
Yifei Duan ◽  
Paul B. Umbanhowar ◽  
Richard M. Lueptow

In dense flowing bidisperse particle mixtures varying in size or density alone, large particles rise (driven by percolation) and heavy particles sink (driven by buoyancy). When the two particle species differ from each other in both size and density, the two segregation mechanisms either enhance (large/light and small/heavy) or oppose (large/heavy and small/light) each other. In the latter case, an equilibrium condition exists in which the two mechanisms balance and the particles no longer segregate. This leads to a methodology to design non-segregating particle mixtures by specifying particle size ratio, density ratio, and mixture concentration to achieve the equilibrium condition. Using DEM simulations of quasi-2D bounded heap flow, we show that segregation is significantly reduced for particle mixtures near the equilibrium condition. In addition, the rise-sink transition for a range of particle size and density ratios matches the predictions of the combined size and density segregation model.


2020 ◽  
Vol 67 (6) ◽  
pp. 565-574
Author(s):  
Lin Liu ◽  
Shuang Lu ◽  
Ya Qi Wu ◽  
Jin Yin Xie ◽  
Jinjuan Xing

Purpose This paper aims to reduce environment pollution caused by benzotriazole. The authors chose one of the best inhibitors from 2-aminobenzimidazole, 2-methylbenzimidazol, 2-mercaptobenzimidazole and benzimidazole in combination with benzotriazole. Design/methodology/approach The electrochemical measurement indicated that 2-methylbenzimidazol had the best inhibition behavior. Then, it was mixed with benzotriazole. Techniques such as field emission scanning electron microscopy, atomic force microscopy, Raman spectroscopy and optical contact angle measurements were used. Findings The results showed that the inhibition efficiency was up to 99.98%, when the mixture concentration was 20 mmol/L and the molar ratio 1:1. Originality/value 1-benzotriazole was mixed with 2-methylbenzimidazol for the first time. During the exist of methyl, 2-methylbenzimidazol has the better inhibition; this point was ignored by researchers. Graphical abstract


Author(s):  
Tat'iana Kuznetsova ◽  
◽  
Valerii Avgustinovich ◽  

Modern automatic control systems use built-in mathematical models for estimation of unmeasured by the direct methods parameters such as NOX emission in aeroengine low-emission combustion chamber. The two models of NOX emissions virtual sensor built into the controller are proposed. A stochastic nonlinear mathematical model is based on the Zeldovich equation. It applies the superposition principle of NOX production in diffusion and homogeneous flames. Probability density distribution functions of the air-fuel mixture concentration in these flames take into account both of a spatial non-uniformity of the mixture composition and a harmonic component of the acoustic waves generated by the heat release. The concept of integral relations models has been developed with the use of numerical modeling of spatial and temporal non-uniformities of the air-fuel mixture concentration (4D-metamodeling) and available experimental data. Another virtual sensor model is based on the neural network predicting NOX emission in gas turbine combustion chamber. The example of a neural network and results of its training on a real combustion chamber is presented. It is shown that the two or three-layer neural network having 20–30 neurons provides an acceptable error (not exceeding 10 %) of the NOX emission display and can be used as a virtual emission sensor in an engine control system. The normalized level of NOx emission per take-off and landing cycle is considered as a target function of the automatic control of low-emission combustion. To estimate the level of NOX emission a built-in virtual sensor is proposed.


2020 ◽  
Vol 840 ◽  
pp. 424-429
Author(s):  
Harry Miyosi Silalahi ◽  
Wei Fan Chiang ◽  
Chia Yi Huang

Poly hydroxyethyl methacrylate (p-HEMA) has a natural property that is very easy to absorb a liquid or solution and become a hydrogel when absorbing water. In this work, by combining p-HEMA material with a cholesteric liquid crystal (CLC), the material can absorb the solution and the optical properties of the liquid crystal will change depending on the solution it absorbs. The solution used in this work is acetone. During the absorption process the p-HEMA material expanded so that the orientation direction of liquid crystal molecular twist with a helical axis along can freely move and change. In this work, we observed the study of transmittance caused by thickness effect and the mixture concentration effect of the poly hydroxyethyl methacrylate liquid crystals (PHM-LC).


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