An innovative method for exhaust gases toxicity evaluation in the miniature turbojet engine

2017 ◽  
Vol 89 (6) ◽  
pp. 757-763 ◽  
Author(s):  
Bartosz Gawron ◽  
Tomasz Białecki ◽  
Anna Janicka ◽  
Aleksander Górniak ◽  
Maciej Zawiślak
Keyword(s):  
Respiratory System ◽  
Direct Method ◽  
Small Scale ◽  
Gas Mixture ◽  
Toxicity Evaluation ◽  
Content Type ◽  
Exhaust Gases ◽  
Turbojet Engine ◽  
Human Respiratory System

Purpose The purpose of this paper is to present an assessment method of the toxicity emission evaluation during combustion in the miniature turbojet engine. Design/methodology/approach A small-scale turbojet engine was used for the research because measurements on real aircraft turbines are complex and expensive. The experiment was performed in accordance with innovative BAT – CELL Bio – Ambient Cell method which consists of determination of virtual toxic impact of the gas mixture on the living cells; it is therefore a direct method. The most significant innovation of this method is that, during the test, which consists of exposing the cells to the gas mixture, the cells are deprived of culture fluid. Findings The preliminary analysis shows that the method used here allows to determine the virtual impact of the gases on the human respiratory system and skin. It could be useful in defining the arduousness of an airport. The obtained results show that both of exhaust gases represent similar toxicity. Practical implications The new in vitro method allows to determine the virtual impact of the gases on the human respiratory system and skin. Significant potential for further research not only on the miniaturised engines, but also in the case of real objects, as this method does not have to be performed in a laboratory. Originality/value The work presents potential application of the innovatory method for exhaust gases toxicity evaluation in jet engines, which could be useful in defining the arduousness of an airport.

Simulation-based dynamic model and speed controller design of a small-scale turbojet engine

2018 ◽  
Vol 90 (2) ◽  
pp. 351-358 ◽  
Author(s):  
Isil Yazar ◽  
Emre Kiyak ◽  
Fikret Caliskan ◽  
T. Hikmet Karakoc
Keyword(s):  
Mathematical Model ◽  
Controller Design ◽  
Small Scale ◽  
Performance Parameters ◽  
Nonlinear Mathematical Model ◽  
Content Type ◽  
Speed Controller ◽  
Turbojet Engine ◽  
Anfis Method ◽  
Operating Points

Purpose This paper aims to present a nonlinear mathematical model of a small-scale turbojet aeroengine and also a speed controller design that is conducted for the constructed nonlinear mathematical model. Design/methodology/approach In the nonlinear mathematical model of the turbojet engine, temperature, rotational speed, mass flow, pressure and other parameters are generated using thermodynamic equations (e.g. mass, energy and momentum conservation laws) and some algebraic equations. In calculation of the performance parameters, adaptive neuro fuzzy inference system (ANFIS) method is preferred in related components. All calculated values from the mathematical model are then compared with the cycle data of the turbojet engine. Because of the single variable control need and effect of noise factor, modified proportional–integral–derivative (PID) controller is treated for speed control. For whole operation envelope, various PID structures are designed individually, according to the operating points. These controller structures are then combined via gain-scheduling approach and integrated to the nonlinear engine model. Simulations are performed on MATLAB/Simulink environment for design and off-design operating points between idle to maximum thrust levels. Findings The cascade structure (proposed nonlinear engine aero-thermal model and speed controller) is simulated and tested at various operating points of the engine and for different transient conditions. Simulation results show that the transitions between the operating points are found successfully. Furthermore, the controller is effective for steady-state load changes. It is suggested to be used in real-time engine applications. Research limitations/implications Because of limited data, only speed control is treated and simulated. Practical implications It can be used as an application in the industry easily. Originality/value First point of novelty in the paper is in calculation of the performance parameters of compressor and turbine components. ANFIS method is preferred to predict performance parameters in related components. Second novelty in the paper can be seen in speed controller design part. Because of the single variable control need and effect of noise factor, modified PID is treated.

Transmission of complex sound signals in the human respiratory system as a function of sound velocity in the utilized gas mixture

2011 ◽  
Vol 57 (6) ◽  
pp. 872-879 ◽  
Author(s):  
V. I. Korenbaum ◽  
A. I. D’yachenko ◽  
A. V. Nuzhdenko ◽  
N. S. Lopatkin ◽  
A. A. Tagil’tsev ◽  
...  
Keyword(s):  
Sound Velocity ◽  
Respiratory System ◽  
Gas Mixture ◽  
Complex Sound ◽  
Human Respiratory System

scholarly journals Mimicking the human respiratory system: Online in vitro cell exposure for toxicity assessment of welding fume aerosol

2020 ◽  
Vol 395 ◽  
pp. 122687 ◽  
Author(s):  
Ryan X. Ward ◽  
Trevor B. Tilly ◽  
Syeda Irsa Mazhar ◽  
Sarah E. Robinson ◽  
Arantzazu Eiguren-Fernandez ◽  
...  
Keyword(s):  
Respiratory System ◽  
Toxicity Assessment ◽  
Welding Fume ◽  
Human Respiratory System

scholarly journals Identification and Mode of Action of a Plant Natural Product Targeting Human Fungal Pathogens

2017 ◽  
Vol 61 (9) ◽  
Author(s):  
Stéphane Dorsaz ◽  
Tiia Snäkä ◽  
Quentin Favre-Godal ◽  
Pierre Maudens ◽  
Nathalie Boulens ◽  
...  
Keyword(s):  
Mammalian Cells ◽  
Reductase Activity ◽  
Transcriptional Analysis ◽  
Small Scale ◽  
Response Analysis ◽  
Content Type ◽  
Fungal Burden ◽  
Sterol Methyltransferase

ABSTRACT Candida albicans is a major cause of fungal diseases in humans, and its resistance to available drugs is of concern. In an attempt to identify novel antifungal agents, we initiated a small-scale screening of a library of 199 natural plant compounds (i.e., natural products [NPs]). In vitro susceptibility profiling experiments identified 33 NPs with activity against C. albicans (MIC50s ≤ 32 μg/ml). Among the selected NPs, the sterol alkaloid tomatidine was further investigated. Tomatidine originates from the tomato (Solanum lycopersicum) and exhibited high levels of fungistatic activity against Candida species (MIC50s ≤ 1 μg/ml) but no cytotoxicity against mammalian cells. Genome-wide transcriptional analysis of tomatidine-treated C. albicans cells revealed a major alteration (upregulation) in the expression of ergosterol genes, suggesting that the ergosterol pathway is targeted by this NP. Consistent with this transcriptional response, analysis of the sterol content of tomatidine-treated cells showed not only inhibition of Erg6 (C-24 sterol methyltransferase) activity but also of Erg4 (C-24 sterol reductase) activity. A forward genetic approach in Saccharomyces cerevisiae coupled with whole-genome sequencing identified 2 nonsynonymous mutations in ERG6 (amino acids D249G and G132D) responsible for tomatidine resistance. Our results therefore unambiguously identified Erg6, a C-24 sterol methyltransferase absent in mammals, to be the main direct target of tomatidine. We tested the in vivo efficacy of tomatidine in a mouse model of C. albicans systemic infection. Treatment with a nanocrystal pharmacological formulation successfully decreased the fungal burden in infected kidneys compared to the fungal burden achieved by the use of placebo and thus confirmed the potential of tomatidine as a therapeutic agent.

Spectral Analysis of Demodulated Ultrasound Returns: Detection of Scatterer Periodicity and Application to Tissue Classification

1997 ◽  
Vol 19 (4) ◽  
pp. 266-277 ◽  
Author(s):  
Scott L. Roth ◽  
Harold M. Hastings ◽  
Steven J.L. Evans ◽  
Michael Esposito ◽  
Clifford Gladstone ◽  
...  
Keyword(s):  
Computer Simulations ◽  
Large Scale ◽  
Direct Method ◽  
Spatial Scales ◽  
Small Scale ◽  
Aortic Tissue ◽  
Full Wave ◽  
Calcified Plaque ◽  
Tissue Characteristics

Ultrasound returns from tissue display variations in amplitude on several spatial scales. Although large-scale variations result from factors such as attenuation, variations on smaller scales are caused by tissue characteristics such as variations in scatterer spacing and reflectance. These small scale variations cause a corresponding variation in the amplitude of the ultrasound return. A simple and direct method for detecting and quantifying periodicity in these variations in the presence of attenuation is described. The radiofrequency ultrasound return is first demodulated by full-wave rectification. The normalized power spectrum of the demodulated return then yields an index that we call the relative Fourier energy. Both computer simulations and in vitro experiments were performed in order to study how relative Fourier energy performed in discriminating between periodic and random scatterer distributions. Computer simulations demonstrated significant differences between the returns from periodic and random scatterer distributions. Ultrasound returns from aortic tissue yielded a relative Fourier energy index that was significantly different between normal vs. atherosclerotic tissue (normal: 0.868 ± 0.076, mean ± s.d., fibrofatty plaque: 0.705 ±0.109, p< 0.01 vs. normal, calcified plaque: 0.753 ± 0.078, p < 0.01 vs. normal). In contrast, no difference was found in comparisons of overall reflectance. SUMMARY

Air Pollution's Effects on the Human Respiratory System

2016 ◽  
Vol 44 (5) ◽  
pp. 383-395 ◽  
Author(s):  
Nehaarika Kantipudi ◽  
Vivek Patel ◽  
Graham Jones ◽  
Markad V. Kamath ◽  
Adrian R. M. Upton
Keyword(s):  
Respiratory System ◽  
Human Respiratory System
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