scholarly journals Results of calculations of soot formation in a tractor diesel engine running on biofuel

2021 ◽  
Vol 2094 (5) ◽  
pp. 052063
Author(s):  
A S Yurlov ◽  
V I Medvedev ◽  
G S Yunusov ◽  
O P Lopatin ◽  
A M Novikov
Keyword(s):  
Soot Formation ◽  
Combustion Engine ◽  
Kinetic Method ◽  
Surface Growth ◽  
Temperature Zone ◽  
Polycyclic Aromatic ◽  
Physical And Chemical ◽  
Rich Mixtures ◽  
Tractor Diesel

Abstract When burning fuel in a diesel internal combustion engine, soot is an undesirable product. To reduce the soot content in the exhaust gases, it is necessary to know the physical and chemical bases of the process of soot formation and soot burnout. Due to the determining role of acetylene in the formation of polycyclic aromatic hydrocarbons in rich mixtures in the low-temperature zone and the key role of acetylene in the surface growth of a particle in the high-temperature zone, it is concluded that the rate of surface growth of a particle is proportional to the concentration of acetylene in the reaction zone, which can be determined by the gas-kinetic method, numerically solving a system of differential equations for the components of the gas mixture under consideration.

Effects of alcohol addition to traditional fuels on soot formation: A review

2020 ◽  
pp. 146808742091088 ◽  
Author(s):  
Yang Hua ◽  
Fushui Liu ◽  
Han Wu ◽  
Chia-Fon Lee ◽  
Yikai Li
Keyword(s):  
Soot Formation ◽  
Combustion Engine ◽  
Hydrocarbon Fuels ◽  
Combustion System ◽  
Complex Environments ◽  
Polycyclic Aromatic ◽  
The Subject ◽  
Alcohol Fuels ◽  
Remarkable Progress ◽  
Broad Overview

Soot is one of the main pollutants produced by incomplete combustion of hydrocarbon fuels, which poses a serious threat to human health and the urban environment. Alcohols have been generally considered to be a potential clean fuel to reduce soot emissions. At present, alcohol fuels represented by methanol, ethanol, butanol and pentanol have been extensively studied and have made remarkable progress. Therefore, this article is written as a broad overview of the subject. The effects of methanol, ethanol, butanol and pentanol additions on the formations of soot and polycyclic aromatic hydrocarbons were systematically summarized from the two aspects of the internal combustion engine bench and the fundamental combustion system. These studies have shown a decreasing or synergistic effect of alcohols addition on soot formation and initially revealed the mechanism of soot formation. However, the formation mechanism of soot in complex environments and the mechanism of the effects of alcohols on soot still need to be studied in depth, which can provide more opportunities for humans to reduce soot production during the combustion of hydrocarbon fuels. Finally, some challenges and research suggestions are outlined in the last section of this review.

Transmission Electron Microscopy of Evaporated Perylene Thin Films

1990 ◽  
Vol 48 (2) ◽  
pp. 336-337
Author(s):  
C. Ewins ◽  
J.R. Fryer
Keyword(s):  
Electron Microscopy ◽  
Thin Films ◽  
Transmission Electron Microscopy ◽  
Molecular Electronics ◽  
High Vacuum ◽  
Amorphous Layer ◽  
Electric Heater ◽  
Transmission Electron ◽  
Polycyclic Aromatic

The preparation of thin films of organic molecules is currently receiving much attention because of the need to produce good quality thin films for molecular electronics. We have produced thin films of the polycyclic aromatic, perylene C10H12 by evaporation under high vacuum onto a potassium chloride (KCl) substrate. The role of substrate temperature in determining the morphology and crystallography of the films was then investigated by transmission electron microscopy (TEM).The substrate studied was the (001) face of a freshly cleaved crystal of KCl. The temperature of the KCl was controlled by an electric heater or a cold finger. The KCl was heated to 200°C under a vacuum of 10-6 torr and allowed to cool to the desired temperature. The perylene was then evaporated over a period of one minute from a molybdenum boat at a distance of 10cm from the KCl. The perylene thin film was then backed with an amorphous layer of carbon and floated onto copper microscope grids.

Role of alterations in ca2+‐associated signaling pathways in the immunotoxicity of polycyclic aromatic hydrocarbons

1995 ◽  
Vol 45 (2) ◽  
pp. 101-126 ◽  
Author(s):  
Donna R. Davila ◽  
DeAnn P. Davis ◽  
Kerry Campbell ◽  
John C. Cambier ◽  
Letitia A. Zigmond ◽  
...  
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Signaling Pathways ◽  
Aromatic Hydrocarbons ◽  
Polycyclic Aromatic

The role of physical and chemical characteristics in assessing the performance of a new biological vascular graft

1989 ◽  
Vol 23 (4) ◽  
pp. 443-450 ◽  
Author(s):  
G. Roberts ◽  
H. McCormack ◽  
V. Ketharanathan ◽  
D. G. Macleish ◽  
P. L. Field ◽  
...  
Keyword(s):  
Vascular Graft ◽  
Chemical Characteristics ◽  
Physical And Chemical Characteristics ◽  
Physical And Chemical

Interaction with Endogenous Microorganisms, Comamonas testosteroni Enhanced the Degradation of Polycyclic Aromatic Hydrocarbon in Soil

2021 ◽  
Author(s):  
Xueting Sun ◽  
Xin Li ◽  
Yue Cui ◽  
Ziwei Jiang ◽  
Qiao Wang ◽  
...  
Keyword(s):  
Contaminated Soil ◽  
Structural Equation ◽  
Functional Role ◽  
Degradation Rate ◽  
Structural Equation Models ◽  
Low Molecular Weight ◽  
Comamonas Testosteroni ◽  
Functional Bacteria ◽  
Polycyclic Aromatic

Abstract This study was to explore the functional role of Comamonas testosteroni (Ct) on soil indigenous microorganisms, and analyze the effect of Ct on PAHs degradation in PAH-contaminated soil. Results showed that inoculation of Ct could degrade naphthalene (Nap), phenanthrene (Phe), and benzo [α] pyrene (BaP) significantly. The degradation rate of Nap, Phe and BaP was 81.18%, 63.38% and 37.98% on day 25, respectively, suggesting that the low molecular weight of Nap and Phe were easier to be degraded by microorganisms than BaP. Network analysis showed that inoculation of Ct significantly increased the bacteria closely related to PAHs. Structural equation models confirmed Steroidobacter as functional bacteria could affect the degradation of Nap and BaP. Inoculated Ct could effectively enhance the synergy among indigenous bacteria to degrade PAHs. This would be helpful to understand the function of inoculated strains in PAH-contaminated soil and identify functional microorganisms of PAHs remediation.

Impact of some environmental chemical carcinogens on the incidence of hormone-dependent tumors and possible mechanisms of its realization (literary review)

2021 ◽  
Vol 99 (2) ◽  
pp. 44-55
Author(s):  
I.O. Chernychenko ◽  
◽  
N.V. Balenko ◽  
O.M. Lytvychenko ◽  
V.F. Babii ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Functional Organization ◽  
Endocrine System ◽  
Epidemiological Data ◽  
Environmental Carcinogens ◽  
Chemical Carcinogens ◽  
Environmental Chemical ◽  
Polycyclic Aromatic ◽  
Pollution Emissions

Objective: We determined the possible effects of priority chemical environmental carcinogens on the incidence of hormone-dependent tumors and the mechanisms of their effect on the basis of the analysis of literature data and our own research. Results: The performed analysis demonstrates the scanity of the research devoted to the study of chemical carcinogens which are concerned only with the class of polycyclic aromatic hydrocarbons (PAH), benzo(a)pyrene (BP), atmospheric pollution, emissions from vehicles, the cadmium heavy metal and products of smoking containing these substances. The connection with PAH (BP) and the development of breast, ovarian cancer, cadmium with the development of breast, endometrial, ovarian cancer in women and prostate cancer in men was established. Epidemiological data, combined with experimental ones, suggest a possible contribution of carcinogens into the increase of the incidence of hormone-dependent tumors. At the same time, mechanisms of action of PAH and cadmium on the development of hormone-dependent tumors are unclear. The accumulated experimental and epidemiological data allow us to conclude that the oncological danger of these carcinogens lies in the combination of genotoxic and hormone-mimetic properties; the main mechanisms, involved in the realization of the effect of BP and cadmium, are associated with changes and disorders at different levels of the structural and functional organization of the organism, including the endocrine system, which can lead to the development of tumors. The urgency of the problem of the incidence of hormone-dependent tumors and the potential role of the studied chemical carcinogens as pollutants of the environment of human functions indicate the need to take these circumstances into account when developing and implementing preventive measures.

Transportation pathways of pesticides in two major watersheds of Istanbul, Turkey

2004 ◽  
Vol 49 (3) ◽  
pp. 165-172 ◽  
Author(s):  
M. Yazgan ◽  
A. Tanik
Keyword(s):  
Chemical Properties ◽  
Surface Flow ◽  
Priority List ◽  
Pesticide Pollution ◽  
Consumption Values ◽  
Annual Consumption ◽  
Agricultural Areas ◽  
Physical And Chemical ◽  
And Chemical Properties

The study covers the investigation of pesticides in terms of consumption, toxicological classification and various intrinsic physical and chemical properties like DT50, KOC, GUS, solubility that describe the important mechanisms prevailing in soil, namely persistence and mobility. These mechanisms help to estimate the transportation pathways of pesticides on soil till they reach the receiving water after being applied on land. Classification is done in three groups, those likely to appear in surface flow, those that appear in groundwater and those that present transient conditions. Such an approach that also takes into account toxicological levels and annual consumption values of pesticides will act as a tool to prepare the priority list of pesticides that need special care during their transportation. The fate of pesticides is a difficult task to solve, however, such a methodology, puts forth a rough estimate on their behavior in spite of uncertainties in many of the parameters describing mechanisms like persistence and mobility. The agricultural areas of two watersheds of Istanbul are selected as target areas to describe the approach, which is also checked with another approach estimating pesticide pollution potential that considers various other properties of pesticides. Almost similar findings are depicted with 85% proximity. The methodology presented in the paper illustrates and emphasizes the significant role of pesticide properties in determining their fate in soil after being applied.

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