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Number of results: 57
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Abstract

This study was carried out on the background of Sutong Bridge project based on fracture mechanics, aiming at analyzing the growth mechanism of fatigue cracks of a bridge under the load of vehicles. Stress intensity factor (SIF) can be calculated by various methods. Three steel plates with different kinds of cracks were taken as the samples in this study. With the combination of finite element analysis software ABAQUS and the J integral method, SIF values of the samples were calculated. After that, the extended finite element method in the simulation of fatigue crack growth was introduced, and the simulation of crack growth paths under different external loads was analyzed. At last, we took a partial model from the Sutong Bridge and supposed its two dangerous parts already had fine cracks; then simulative vehicle load was added onto the U-rib to predict crack growth paths using the extended finite element method.

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Authors and Affiliations

H. Zhu
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Abstract

This study sought to evaluate the effect of speech intensity on performance of the Callsign Acquisition Test (CAT) and Modified Rhyme Test (MRT) presented in noise. Fourteen normally hearing listeners performed both tests in 65 dB A white background noise. Speech intensity varied while background noise remained constant to form speech-to-noise ratios (SNRs) of -18, -15, -12, -9, and -6 dB. Results showed that CAT recognition scores were significantly higher than MRT scores at the same SNRs; however, the scores from both tests were highly correlated and their relationship for the SNRs tested can be expressed by a simple linear function. The concept of CAT can be easily ported to other languages for testing speech communication under adverse listening conditions.

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Authors and Affiliations

Misty Blue-Terry
Maranda McBride
Tomasz Letowski
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Abstract

Flow fields could be of great interest in the study of sound propagation in aeroengines. For ducts with rigid boundaries, the fluid-resonant category may contribute significantly to unwanted noise. An understanding of the multi-modal propagation of acoustic waves in ducts is of practical interest for use in the control of noise in, for example, aero-engines, automotive exhaust and heating or ventilation systems. The purpose of our experiments was to test the acoustic energy transmission of duct modes based on studies carried out by the sound intensity technique. Sound intensity patterns in circular duct are discussed of modal energy analysis with particular reference to proper orthogonal decomposition and dynamic mode decomposition. The authors try to justify some advantages of the sound intensity experimental research in this area. In the paper, the wide-band sound signal propagated from source approximated with loudspeaker in hard-walled duct is imaged using a sound intensity - based approach. For a simple duct geometry, the sound intensity field is examined visually and by performing a modal decomposition greater insight into the acoustic structures is obtained. The image of sound intensity fields below and above “cut-off” frequency region are found to compare acoustic modes which might resonate in duct.

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Authors and Affiliations

Stefan Weyna
Witold Mickiewicz
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Abstract

The aim of this paper is two-fold. First, some basic notions on acoustic field intensity and its measurement are shortly recalled. Then, the equipment and the measurement procedure used in the sound intensity in the performed research study are described. The second goal is to present details of the design of the engineered 3D intensity probe, as well as the algorithms developed and applied for that purpose. Results of the intensity probe measurements along with the calibration procedure are then contained and discussed. Comparison between the engineered and the reference commercial probe confirms that the designed construction is applicable to the sound field intensity measurements with a sufficient effectiveness.

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Authors and Affiliations

Bożena Kostek
Andrzej Czyżewski
Józef Kotus
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Abstract

The model of odour intensity analyzer in a form of two layers of neurons. was proposed. The first layer consists of specific receptors of odorants, which are randomly distributed. The odorant influence on odour intensity of mixtures is depends on the number of suitable receptors and number of their connections with the second layer neurons (the degree of divergence). The second layer neuron is stimulated with the same power after receiving the signal from any receptor or receptors. Il was assumed that the odour intensity is directly proportional to the number of stimulated neurons in the second layer. The investigated model contained 1000 neurons in the first layer and 1456 neurons in the second layer. The first layer contained receptors A and B (RA and RB) in quantities 15% RA, IS% RB and 30% RA, 10% RB. Receptors A characterized the divergence I :9, receptors B - 1 :25. The stimulus were mixtures containing 5-100 molecules A and B per hundred (x , = 0.0, 0.2, 0.5, 0.8 and 1.0). The general similarity of • the model reaction with that of the human smell reaction was found.
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Authors and Affiliations

Joanna Kośmider
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Abstract

Sound intensity measurements using special sensors in a form of pressure-velocity and pressure-pressure probes are becoming more and more often the method of choice for characterization of sound sources. Its wider usability is blocked by the probes’ costs. This paper is on a possible modification of the well-known pressure-pressure sound intensity measurement method. In the proposed new approach a synchronized measurement procedure using only single microphone is used. The paper presents the basics of the sound intensity theory, a review of currently usedmethods of intensity measurement and requirements and limitations of the new method. In the proposed approach one microphone and a properly designed positioning system is used. The application of the method to study the directional characteristics of an active loudspeaker system have been described in detail. The obtained results were compared with those of measurements performed with a commercial p–u probe. The paper contains conclusions indicating advantages of the applied method in comparison with standard pressure measurement methods.

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Authors and Affiliations

Witold Mickiewicz
Michał Raczyński
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Abstract

The aim of this work is to present new reliability characteristics expressed as functions of some variable expressing the measure of effective operation of a machine or a device. These characteristics can be used for both renewable and non-renewable objects. Their mathematical idea reflects the essence of already known characteristics, i.e. it expresses the probability of failure but expressed as a function of a variable, not necessarily identified with time.
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Authors and Affiliations

Gabriela Kopania
Anna Kuczmaszewska
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Abstract

Fatigue cracks in machine components are subjected to stress fields induced by the external load and residual stresses resulting from the surface treatment. Stress fields in such cases are characterized by non-uniform distributions and handbook stress intensity factor solutions for such configurations are not available. The method presented below is based on the generalized weight function technique enabling the stress intensity factors to be calculated for any Mode I loading applied to arbitrary planar convex crack. The method is particularly suitable for modeling fatigue crack growth in presence of complex stress fields.
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Authors and Affiliations

Z. Wu
H. Jakubczak
G. Glinka
K. Molski
L. Nilsson
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Abstract

In this paper, selected aspects of energy efficiency are shown. The European Union regulations in area of energy efficiency such as Directive 2012/27/EU, are discussed. The national legal regulations which describe energy efficiency such as the Energy Efficiency Act are presented. Principles concerning the obligation of energy savings and energy audits of enterprises are described. National, regional and local programs and measures concerning the improvement of energy efficiency are performed. These are horizontal measures and energy efficiency measures in: industry, transport, the buildings of public institutions and energy generation and supplies. National economy energy efficiency is shown. The energy intensity indicators (primary, final) and rate of their changes in last years are performed. Moreover, directions of undertakings connected with the possible future reduction in energy intensity of the national economy, are defined. An analysis of energy efficiency measures and solutions for the improvement of energy efficiency, especially in industry and households, is performed. The improvement of economy energy intensity indicators constitutes the most effective solution which brings significant economic, technical and environmental benefits such as an increase in economic innovation and its competitiveness, the improvement of the energy supply security level, a reduction in the consumption of natural resources and a reduction of air pollution and greenhouse gas emissions. The conclusions contain an analysis of the present level of energy efficiency in Poland and the perspectives of its increase in the future along with the benefits connected with it.

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Authors and Affiliations

Waldemar Dołęga
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Abstract

550 individual odour intensity (S) assessments of 62 samples of air polluted with 2-propanol were collected (concentration c = 46-2 1000 mg/m3). The data were used to establish odour detection threshold of 2-propanol by extrapolation to S = 0 in the coordinate system of S-log c. The obtained values were compared with triangular tests results and data published in the literature. A reason for apparent positive deviations from Weber-Fechner law within a range of low odour intensities was indicated,
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Authors and Affiliations

Joanna Kośmider
Beata Krajewska
Monika Sosialuk
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Abstract

The article analyzes the language means by which the intensity of emotional processes in Polish, Russian and Ukrainian is reflected on the example of the names of emotions that are part of the “compassion” group. By the intensity of emotions, we mean a quantitative assessment of the quality of the emotional process relative to a certain norm. Verbalizers of the intensity of emotional experiences include lexemes describing the power of the emotions themselves and the impact of the emotions on a person. The characteristics of the power of the manifestation of emotions are objectified most often with the help of adjectives and adverbs. Verbalization of the power of the influence of emotional experiences on a person in Polish, Russian and Ukrainian can occur by objectifying the temperature characteristics of feelings, as well as through association with images of fluid and fire. Besides intensity on the quantitative side, a feeling is also characterized by duration – the time interval between the beginning and the end of an emotion. In terms of duration, the emotions of the “compassion” group in Polish, Russian and Ukrainian are described as sudden and short-lived states.
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Authors and Affiliations

Larysa Nikolayenko
1
ORCID: ORCID

  1. O.O. Potebnyа Institute of Linguistics of NAS of Ukraine
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Abstract

Searching for dependance of odour intensity on degree of dillution of basic samples with pure air, samples aromatised with citrus oil and containing difTerent amounts of acetone, ethanol, isopropanol, isoamyl acetate were studied. 192 individual odour intensity assesments of 16 samples were collected. Dependence of odour intensity on acetone concentration determined with chromatographic analysis (110-16500 mg/m3) was defined on the basis of 311 individual odour intensity assessments of 24 samples. The measurements' results were elaborated without initial assumptions concerning character of a psychophisical equation and without initial selection of empirical data. Automatic Networks Designer (Statistica Neural Network, StatSoft) was used. Dependence of odour intensity on concentration was described with logistic function resembling Stevens law within a small concentrations range and Weber-Fechner law within a high concentrations range.
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Authors and Affiliations

Joanna Kośmider
Monika Sosialuk
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Abstract

Periodic inventory and check surveys of the surfaces in engineering structures using terrestrial laser scanning require performing scans from many locations. The survey should be planned so as to obtain full coverage of the measured surface with a point cloud of appropriate density. Due to a variety of terrain obstacles in the close vicinity of the surveyed structure, structural and technical elements, as well as machinery and construction equipment (whose removal is impossible e.g. because of their role in the building and protection of the structure), it is often necessary to combine scans acquired from locations having different measurement geometry of the scene and performed in different lighting conditions. This makes it necessary to fill in blank spots with data of different spectral and geometric quality. This paper presents selected aspects of data harmonization in terrestrial laser scanning. The laser beam incidence angle and the scanning distance are assumed as parameters affecting the quality of the data. Based on the assumed minimum parameters for spectral data, an example of a harmonizing function for the concrete surface of a slurry wall was determined, and the methodology for determining its parameters was described. The presented solution for spectral data harmonization is based on the selection of reference fields representative of a given surface, and their classification with respect to selected geometric parameters of the registered point cloud. For geometric data, possible solutions to the harmonization problem have been analyzed, and criteria for point cloud reduction have been defined in order to obtain qualitatively consistent data. The presented results show that harmonization of point clouds obtained from different stations is necessary before their registration, in order to increase the reliability of analyses performed on the basis of check survey results in the assessment of the technical condition of a surface, its deformation, cracks and scratches.
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Authors and Affiliations

Janina Zaczek-Peplinska
1
ORCID: ORCID
Maria Elżbieta Kowalska
1
ORCID: ORCID
Edward Nowak
1
ORCID: ORCID

  1. Warsaw University of Technology, Faculty of Geodesy and Cartography, Politechniki 1, 00-661 Warsaw, Poland
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Abstract

ll was proved that the activity of basic proteinases (pH 8.3) and acid proteinases (pH 4.0) of the Antarctic krill increases exponentially in spring-summer season (September-December); the activity of the first ones is 6 times higher and increases more rapidly. The positive relation between the proteolytic activity and the degree of gut filling of krill was also evidenced. The lack of high activity of acid proteinases in early spring does not support the suggestions of Ikeda and Dixon (1982) that during Antarctic winter krill takes energy from the autoproteolysis of own body proteins.

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Authors and Affiliations

Edward Kołakowski
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Abstract

Improving energy efficiency is key to moving toward sustainable development. It contributes to the reduction of energy consumption and carbon emissions, as well as to climate change mitigation. Indicators of energy efficiency play an important role in this field because their improvement is targeted by policy makers. Indicators based on the ratio between energy consumption and gross domestic product (GDP) are currently used by multiple key organizations, including Eurostat and the World Bank, as the main energy efficiency indicators. This study examines the most widely used indicators and identifies their deficiencies. Over the last decades, these indicators tend to show a continuous strong improvement, signifying positive progress toward energy efficiency, even in cases when the physical consumption of energy has increased significantly. This phenomenon is based on GDP adjustment. The energy intensity of economies, used currently to measure energy efficiency, masks problems and has led to the green labeling of wealthier economies. An analysis of energy efficiencies reported for multiple countries and the structure of their energy spending shows that the reported values are counterproductive for comparing economies in the context of environmental protection. The indicators sanction economies with low energy consumption and low or moderate GDP. The economies belonging to the group of the largest energy spenders per capita are labeled highly efficient because of GDP adjustment. Decision makers are therefore prompted to focus on GDP growth even at the cost of a major increase in energy consumption. An additional problem in the indicators is that they do not properly model international trade. The responsibility for energy spending is shifted toward the producers of energy-intensive goods and services. Energy intensity is a useful indicator to measure the resistance of an economy to the volatilities of energy prices. However, the challenges in the fields of environmental pollution and climate change are related to physical processes and energy consumption rather than to changes in the GDP or the monetary valuation of products and services. Indicators measuring energy efficiency as GDP per unit of energy use are inadequate and misleading as principal tools to measure energy efficiency.

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Authors and Affiliations

Yavor Kolarov
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Abstract

In the paper the author has described the visualization methods in acoustic flow fields and show how these methods may assist scientists to gain understanding of complex acoustic energy flow in real-life field. A graphical method will be presented to determine the real acoustic wave distribution in the flow field. Visualization of research results, which is unavailable by conventional acoustics metrology, may be shown in the form of intensity streamlines in space, as a shape of floating acoustic wave and intensity isosurface in three-dimensional space. In traditional acoustic metrology, the analysis of acoustic fields concerns only the distribution of pressure levels (scalar variable), however in a real acoustic field both the scalar (acoustic pressure) and vector (the acoustic particle velocity) effects are closely related. Only when the acoustic field is described by both the potential and kinetic energies, we may understand the mechanisms of propagation, diffraction and scattering of acoustic waves on obstacles, as a form of energy image. This attribute of intensity method can also validate the results of CFD/CAA numerical modeling which is very important in any industry acoustic investigations.

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Authors and Affiliations

Stefan Weyna
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Abstract

Noise propagation within ducts is of practical concern in many areas of industrial processes where a fluid has to be transported in piping systems. The paper presents experimental data and visualization of flow in the vicinity of an abrupt change in cross-section of a circular duct and on obstacles inside where the acoustic wave generates nonlinear separated flow and vortex fields. For noise produced by flow wave of low Mach number, laminar and turbulent flows are studied us- ing experimental sound intensity (SI) and laser particle image velocimetry (PIV) technique adopted to acoustics (A-PIV). The emphasis is put on the development and application of these methods for better understanding of noise generation inside the acoustic ducts with different cross-sections. The intensity distribution inside duct is produced by the action of the sum of modal pressures on the sum of modal particle velocities. However, acoustic field is extremely complicated because pressures in non-propagating (cut-off) modes cooperate with particle velocities in propagating modes, and vice versa. The discrete frequency sound is strongly influenced by the transmission of higher order modes in the duct. By under- standing the mechanism of energy in the sound channels and pipes we can find the best solution to noise abatement technology. In the paper, numerous methods of visualization illustrate the vortex flow as an acoustic velocity or sound intensity stream which can be presented graphically. Diffraction and scattering phenomena occurring inside and around the open-end of the acoustic duct are shown.
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Authors and Affiliations

Stefan Weyna
Witold Mickiewicz
Michał Pyła
Michał Jabłoński
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Abstract

Terrestrial laser scanning (TLS) is one of the instruments for remote detection of damage of structures (cavities, cracks) which is successfully used to assess technical conditions of building objects. Most of the point clouds analysis from TLS relies only on spatial information (3D–XYZ). This study presents an approach based on using the intensity value as an additional element of information in diagnosing technical conditions of architectural structures. The research has been carried out in laboratory and field conditions. Its results show that the coefficient of laser beam reflectance in TLS can be used as a supplementary source of information to improve detection of defects in constructional objects.

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Authors and Affiliations

Czesław Suchocki
Marcin Jagoda
Romuald Obuchovski
Dominykas Šlikas
Jūratė Sužiedelytė -Visockienė
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Abstract

A system setup for measurements of acoustic field, together with the results of 3D visualisations of acoustic energy flow are presented in the paper. Spatial sampling of the field is performed by a Cartesian robot. Automatization of the measurement process is achieved with the use of a specialized control system. The method is based on measuring the sound pressure (scalar) and particle velocity(vector) quantities. The aim of the system is to collect data with a high precision and repeatability. The system is employed for measurements of acoustic energy flow in the proximity of an artificial head in an anechoic chamber. In the measurement setup an algorithm for generation of the probe movement path is included. The algorithm finds the optimum path of the robot movement, taking into account a given 3D object shape present in the measurement space. The results are presented for two cases, first without any obstacle and the other - with an artificial head in the sound field.

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Authors and Affiliations

Maciej Szczodrak
Bożena Kostek
Andrzej Czyżewski
Józef Kotus
Adam Kurowski
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Abstract

Outdoor remote temperature measurements in the infrared range can be very inaccurate because of the influence of solar radiation reflected from a measured object. In case of strong directional reflection towards a measuring device, the error rate can easily reach hundreds per cent as the reflected signal adds to the thermal emission of an object. As a result, the measured temperature is much higher than the real one. Error rate depends mainly on the emissivity of an object and intensity of solar radiation. The position of the measuring device with reference to an object and the Sun is also important. The method of compensation of such undesirable influence of solar radiation will be presented. It is based on simultaneous measurements in two different spectral bands, shor-twavelength and long-wavelength ones. The temperature of an object is derived from long-wavelength data only, whereas the short-wavelength band, the corrective one, is used to estimate the solar radiation level. Both bands were selected to achieve proportional changes of the output signal due to solar radiation. Knowing the relation between emissivity and solar radiation levels in both spectral bands, it is possible to reduce the measurement error several times.

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Authors and Affiliations

Henryk Madura
Mariusz Kastek
Tomasz Sosnowski
Tomasz Orżanowski
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Abstract

The world economy is constantly faced with crises that cause a significant negative impact. Each crisis poses new challenges to the economy and, on the one hand, inhibits economic growth, and on the other hand, can become a powerful stimulus for the development and rethinking of fundamental approaches to its construction. Conducting an analysis and establishing relationships between the economic situation and the state of the energy sector make it possible not only to predict the future but also to develop specific steps to prevent crises or reduce their negative impact. At the same time, establishing and evaluating the relationship between key economic and energy indicators, the main one of which is definitely the energy intensity of GDP, will provide an opportunity to understand how improving energy security will affect the economic situation in the country. The generalization of Ukraine’s experience in rebuilding and recovering the economy after the biggest crisis creates a basis for further research in the field of energy management, crisis management, economics, and the construction of investment policy. The reconstruction of Ukraine after the war has the potential to become the most significant stimulus for development and economic growth. During the crisis, it is very important to pay attention to the country’s energy security. In particular, it is necessary to ensure the diversification of energy resources, taking into account their rising cost. Energy markets are currently experiencing extreme volatility caused by geopolitical tensions, which requires additional attention in the development and implementation of strategic guidelines for sustainable economic recovery in Ukraine.
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Authors and Affiliations

Anastasiia Hryhorenko
1
ORCID: ORCID
Hanna Kotina
1
ORCID: ORCID
Maryna Stepura
1
ORCID: ORCID
Hanna Zavystovska
2
ORCID: ORCID

  1. Department of Finance named after Victor Fedosov, Kyiv National Economic University named after Vadym Hetman, Ukraine
  2. Faculty of Finance of the Department of Finance named after Victor Fedosov, Kyiv National Economic University named after Vadym Hetman, Ukraine
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Abstract

In this paper, the two-temperature thermoelasticity model is proposed to a specific problem of a thermoelastic semi-infinite solid. The bounding plane surface of the semi-infinite solid is considered to be under a non-Gaussian laser pulse. Generalized thermoelasticity analysis with dual-phase-lags is taken into account to solve the present problem. Laplace transform and its inversion techniques are applied and an analytical solution as well as its numerical outputs of the field variables are obtained. The coupled theory and other generalized theory with one relaxation time may be derived as special cases. Comparison examples have been made to show the effect of dual-phase-lags, temperature discrepancy, laser-pulse and laser intensity parameters on all felids. An additional comparison is also made with the theory of thermoelasticity at a single temperature.

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Authors and Affiliations

Ashraf M. Zenkour
Ahmed E. Abouelregal
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Abstract

The possibility of applying gas chromatograph to air samples discrimination in regard to odour intensity and hedonic quality was examined. The air samples were arornatised with lemon oil and four admixtures. fourteen distinctive points of a chromatogram were appointed and the distances from the points lo a set basis were measured. The set of h 1-h 14 parameters (inputs) and varied individual sensory estimations of I and H (outputs) was used as a training data set for NN. Possibility of discrimination of the odour quality of the samples situated close to the threshold of odour quality difference detectability was confirmed on the level of approximately one.
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Authors and Affiliations

Joanna Kośmider
Beata Krajewska

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