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Search results for: Principal Component Analysis
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The chemistry of river–lake systems in the context of permafrost occurrence (Mongolia, Valley of the Lakes). Part I. Analysis of ion and trace metal concentrations
PublicationThis study provides a description of water chemistry in river–lake systems located in central Mongolia, at the borderline of permafrost occurrence. The analysis involved water samples collected from two river–lake systems: Baydrag River–Böön Tsagaan Lake system, and Shargalyuut/Tuyn Rivers–Orog Lake system. In the water samples, ions and trace elements were detected and quantified. Additionally, the parameters of pH, electrical...
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Self-Organizing Map representation for clustering Wikipedia search results
PublicationThe article presents an approach to automated organization of textual data. The experiments have been performed on selected sub-set of Wikipedia. The Vector Space Model representation based on terms has been used to build groups of similar articles extracted from Kohonen Self-Organizing Maps with DBSCAN clustering. To warrant efficiency of the data processing, we performed linear dimensionality reduction of raw data using Principal...
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Self–Organizing Map representation for clustering Wikipedia search results
PublicationThe article presents an approach to automated organization of textual data. The experiments have been performed on selected sub-set of Wikipedia. The Vector Space Model representation based on terms has been used to build groups of similar articles extracted from Kohonen Self-Organizing Maps with DBSCAN clustering. To warrant efficiency of the data processing, we performed linear dimensionality reduction of raw data using Principal...
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Spatial Differences in the Chemical Composition of Surface Water in the Hornsund Fjord Area: A Statistical Analysis with A Focus on Local Pollution Sources
PublicationSurface catchments in Svalbard are sensitive to external pollution, and yet what is frequently considered external contamination may originate from local sources and natural processes. In this work, we analyze the chemical composition of surface waters in the catchments surrounding the Polish Polar Station in Svalbard, Hornsund fjord area. We have pooled unpublished and already published data describing surface water composition...
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Leakage detection and localisation in drinking water distributionnetworks by MultiRegional PCA
PublicationMonitoring is one of the most important steps in advanced control of complex dynamic systems. Precise information about systems behaviour, including faults indicating, enables for efficient control. The paper describes an approach to detection and localisation of pipe leakage in Drinking Water Distribution Systems (DWDS) representing complex and distributed dynamic system of large scale. Proposed MultiRegional Principal Component...
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Performance evaluation and model-based optimization of the mainstream deammonification in an integrated fixed-film activated sludge reactor
PublicationThis study aimed to model and optimize mainstream deammonification in an integrated fixed-film activated sludge (IFAS) pilot plant under natural seasonal temperature variations. The effect of gradually decreasing temperature on the performance was evaluated during a winter season and a transition period to summer conditions, and the correlation of the performance parameters was investigated using principal component analysis (PCA)....
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Searching for Solvents with an Increased Carbon Dioxide Solubility Using Multivariate Statistics
PublicationIonic liquids (ILs) are used in various fields of chemistry. One of them is CO2 capture, a process that is quite well described. The solubility of CO2 in ILs can be used as a model to investigate gas absorption processes. The aim is to find the relationships between the solubility of CO2 and other variables—physicochemical properties and parameters related to greenness. In this study, 12 variables are used to describe a dataset...
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Detection of apple in orange juice using ultra-fast gas chromatography
PublicationThe determination of authenticity is an increasingly important issue for food quality and safety. The use of an electronic nose based on ultra-fast gas chromatography technique ensures rapid analysis of the volatile compounds from food products. Due to the fact that this technique enables chemical profiling of agricultural products, it can be an effective tool for authentication when combined with chemometrics. In this article...
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Thermal degradation assessment of canola and olive oil using ultra-fast gas chromatography coupled with chemometrics
PublicationOil blending is often used to enhance the properties of vegetable oils. The admixture of a more thermally stable oil makes the resulting blend more suitable for use in frying. A new method of quality assessment of vegetable oils used in frying is presented in this paper. In this method, ultra-fast gas chromatography coupled with flame ionization detector and chemometrics is employed. Principal component analysis was used for data...
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Potentiometric sensor containing set of ion selective electrodes with lipid modified membranes for quality assessment of tested non-alcoholic beverages
PublicationPotentiometric sensors may be a good tool for fast quality control of commercial drinks. In this work, such a sensor, containing a set of ion-selective electrodes with lipid-modified membranes (benzylhexadecyldimethylammonium chloride monohydrate, hexadecylamine, 1-dodecanol, elaidic acid, cholesterol) was used for discrimination and quality control of non-alcoholic beverages, mainly composed of sugar and citric acid. It was found...
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Zastosowanie metod analizy wielowymiarowej w rozpoznawaniu komórek nowotworowych
PublicationArtykuł przedstawia sposób zastosowania metody k-średnich (k-means) do analizy danych o komórkach nowotworu piersi pochodzących z Breast Cancer Wisconsin Data Set, pobranych podczas biopsji cienkoigłowej. Celem analizy jest sprawdzenie, czy na podstawie parametrów geometrycznych pobranych komórek istnieje możliwość automatycznego podziału pacjentek na grupy o podobnym ryzyku wystąpienia nowotworu złośliwego. Zastosowanie metody...
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Music Data Processing and Mining in Large Databases for Active Media
PublicationThe aim of this paper was to investigate the problem of music data processing and mining in large databases. Tests were performed on a large data-base that included approximately 30000 audio files divided into 11 classes cor-responding to music genres with different cardinalities. Every audio file was de-scribed by a 173-element feature vector. To reduce the dimensionality of data the Principal Component Analysis (PCA) with variable...
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Music Mood Visualization Using Self-Organizing Maps
PublicationDue to an increasing amount of music being made available in digital form in the Internet, an automatic organization of music is sought. The paper presents an approach to graphical representation of mood of songs based on Self-Organizing Maps. Parameters describing mood of music are proposed and calculated and then analyzed employing correlation with mood dimensions based on the Multidimensional Scaling. A map is created in which...
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Application of electronic nose based on fast GC for comparison of aroma profiles of homemade cherry "Nalewka" made with addition of different amount of sugar
PublicationNalewka is a traditional Polish homemade spirit beverage and there are many different recepies for the production of nalewkas. However, it is not knownwhat amount of sugar can have influence of their aroma profiles. There is little information on the comparison of aroma profiles of Polish cherry nalewkas made with addition of different amount of sugar. For this purpose electronic nose based on fast GC has been used. Electronic...
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Application of electronic nose based on fast GC for comparison of aroma profiles of homemade cherry "Nalewka" made with addition of different amount of sugar
PublicationNalewka is a traditional Polish homemade spirit beverage and there are many different recepies for the production of nalewkas. However, it is not knownwhat amount of sugar can have influence of their aroma profiles. There is little information on the comparison of aroma profiles of Polish cherry nalewkas made with addition of different amount of sugar. For this purpose electronic nose based on fast GC has been used. Electronic...
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Differentiation Between Spirits According to Their Botanical Origin
PublicationAgricultural distillates are used for the production of spirit beverages. As more and more products with a specific botanical composition specified on the label are produced (e.g. rye vodkas, wheat vodkas and Polish Vodka, which cannot be produced with the addition of maize distillate), it is necessary to look for quicker and more accurate methods allowing the determination of botanical origin of alcoholic beverages and materials...
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Application of an Electronic Nose Instrument to Fast Classification of Polish Honey Types
PublicationThe paper presents practical utilization of an electronic nose prototype, based on the FIGARO semiconductor sensors, in fast classification of Polish honey types—acacia flower, linden flower, rape, buckwheat and honeydew ones. A set of thermostating modules of the prototype provided gradient temperature characteristics of barbotage-prepared gas mixtures and stable measurement conditions. Three chemometric data analysis methods...
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APPLICATION OF ULTRAFAST GAS CHROMATOGRAPHY TO RECOGNIZE ODOR NUISANCE
PublicationPotentialities of ultrafast gas chromatography applied to periodical monitoring of odor nuisance originating from a municipal landfill have been examined. The results of investigation on classification of the atmospheric air samples collected in a vicinity of the landfill during winter and summer season have been presented. The investigation was performed using ultrafast gas chromatography of Fast/Flash GC type HERACLES II by Alpha...
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Kernel PCA in Application to Leakage Detection in Drinking Water Distribution System
PublicationMonitoring plays an important role in advanced control of complex dynamic systems. Precise information about system's behaviour, including faults detection, enables efficient control. Proposed method- Kernel Principal Component Analysis (KPCA), a representative of machine learning, skilfully takes full advantage of the well known PCA method and extends its application to nonlinear case. The paper explains the general idea of KPCA...
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Optimising approach to designing kernel PCA model for diagnosis purposes with and without a priori known data reflecting faulty states
PublicationFault detection plays an important role in advanced control of complex dynamic systems since precise information about system condition enables efficient control. Data driven methods of fault detection give the chance to monitor the plant state purely based on gathered measurements. However, they especially nonlinear, still suffer from a lack of efficient and effective learning methods. In this paper we propose the two stages learning...
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Water uptake in protective organic coatings and its reflection in measured coating impedance
PublicationWater uptake in commercially available epoxy coating on mild steel using impedance spectroscopy and gravimetry was studied. The water content in the coating was determined using the Brasher-Kingsbury equation and various methods of coating capacitance calculation used in the literature. The obtained results were compared with reference gravimetric data. An overestimation of values obtained from impedance data in relation to gravimetric...
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Aleksandra Parteka dr hab. inż.
PeopleAbout me: I am an associate professor and head of doctoral studies at the Faculty of Management and Economics, Gdansk University of Technology (GdanskTech, Poland). I got my MSc degree in Economics from Gdansk University of Technology (2003) and Universita’ Politecnica delle Marche (2005), as well as MA degree in Contemporary European Studies from Sussex University (2006, with distinction). I received my PhD in Economics...
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Comparison of the Physical and Sensory Properties of Hybrid Citrus Fruit Jaffa® Sweetie in Relation to the Parent Fruits
PublicationIn the presented study, an overall Jaffa sweetie evaluation was made to find a correlation between Citrus grandis Osbeck × Citrus paradisi Macf. and its parent fruits’ (Citrus grandis Osbeck, Citrus paradisi Macf.) properties. Based on the sensory analysis, it was found that the taste and aroma of the new hybrid fruit are close to pummelo. By the use of chromatographic analysis, the selected monoterpenes present in the fruits were...
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Application of chemometric techniques in studies of toxicity of selected commercially available products for infants and children
PublicationThe goal of the present study is to assess the impact of the experimental conditions for extraction procedures (time of extraction, thermal treatment and type of extraction media) as applied to several baby and infant products checked for their possible ecotoxicological response when tested by various ecotoxicity tests(Microtox®, Ostracodtoxkit F™and Xenoscreen YES/YAS™). The systems under consideration are multidimensional by...
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An Approach to Bass Enhancement in Portable Computers Employing Smart Virtual Bass Synthesis Algorithms
PublicationThe aim of this paper is to present a novel approach to the Virtual Bass Synthesis (VBS) algorithms applied to portable computers. The developed algorithms are related to intelligent, rule-based setting of synthesis parameters according to music genre of an audio excerpt and to the type of a portable device in use. To find optimum synthesis parameters of the VBS algorithms, subjective listening tests based on a parametric procedure...
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Remote communication in Scrum teams - a COVID-19 preventive measure or work time optimisation?
PublicationThe article presents the impact of remote work, resulting from the COVID-19 pandemic, on the functioning of Scrum teams. Attempts have been made to analyse the positive and negative aspects of remote work. The article also looks at the impact of remote work on the level of communication and efficiency of Scrum teams. For this purpose, the author conducted research on a sample of 40 organisations that declared to use Scrum methodology,...
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Igor Szpotakowski
PeoplePrincipal Investigator in the four-year project (2020-2024): “Services contracts in private law of the PRC - codification in the era of decodification” funded by the Polish Ministry of Science and Higher Education “Diamond Grant” programme, which is awarded to the most promising young researchers in Poland. Awarded a Ryoichi Sasakawa Young Leaders Fellowship to conduct one-year research (2020-2021) about “The effects of non-performance...
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Gas Detection Using Resistive Gas Sensors And Radial Basis Function Neural Networks
PublicationWe present a use of Radial Basis Function (RBF) neural networks and Fluctuation Enhanced Sensing (FES) method in gas detection system utilizing a prototype resistive WO3 gas sensing layer with gold nanoparticles. We investigated accuracy of gas detection for three different preprocessing methods: no preprocessing, Principal Component Analysis (PCA) and wavelet transformation. Low frequency noise voltage observed in resistive gas...
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PCA based Fault Tolerant MPC
PublicationThis chapter presents a Fault Tolerant - Model Predictive Control (FT-MPC) schemes for sensor faults accommodation. A Fault Detection and Isolation (FDI) Unit, which is an integral part of FT-MPC system, is based on the Principal Component Analysis (PCA) method. Introduced approach enables efficient bias and drift faults accommodation in single, as well as simultaneous faults case. Simple simulation exercise is presented.Rozdział...
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Multibeam sonar data processing for seafloor characterisation
PublicationThe approach to seafloor characterisation was investigated. It relies on calculation of several descriptors (parameters) related to seabed type using three types of multibeam sonar data obtained during seafloor sensing: 1) the grey-level sonar images of seabed, 2) the 3D model of the seabed surface which consist of (x, y, z) points, 3) the set of time domain echo envelopes corresponding to several beams. The proposed method has...
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Potentiometric sensor with lipid-polymer membranes for quality assessment of French red wines
PublicationThe quality of wines resulting from vineyard management is important for consumers due to the taste and price of wines. In this work, the quality of red wines of three vintages has been investigated by potentiometric sensors with six all-solid-state electrodes. Two series of experiments were carried out. The first involved a qualitative analysis of wine of different vintages from freshly opened bottles. The second consisted of...
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Sensory Characteristics of Tonic Waters with Various Sweetening Substances vs Young Consumers' Opinion
PublicationThe attitude of young consumers towards food products containing low calorie sweeteners was analyzed as well as consumers’ awareness to the medical recommendations regarding artificial sweeteners. The questionnaire was carried out within the group of 97 respondents at the age of 21 – 30. Strongly negative attitude towards consumption of food products containing low calorie sweeteners was declared by almost half of respondents....
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Assessment of Lipophilicity Indices Derived from Retention Behavior of Antioxidant Compounds in RP-HPLC
PublicationReverse phase high pressure liquid chromatography was employed in order to evaluate the lipophilicity of antioxidant compounds from different classes, such as phenolic acids, flavanones, flavanols, flavones, anthocyanins, stilbenes, xantonoids, and proanthocyanidins. The retention time of each compound was measured using five different HPLC columns: RP18 (LiChroCART, Purosphere RP-18e), C8 (Zorbax, Eclipse XDBC8), C16-Amide (Discovery...
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Rapid assessment of the authenticity of limequat fruit using the electronic nose and gas chromatography coupled with mass spectrometry
PublicationCitrus fruits are very popular food products. There are many species and varieties of them. There are also documented cases of some citrus fruits causing a severe allergic reaction. Some species of the citrus fruits, especially hybrid ones show a reduced allergenic effect due to the lack of seeds. There is a need for rapid methods for evaluation of citrus’ botanical origin. During research, the headspace of three citrus fruits...
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Determination of flavanols by liquid chromatography with fluorescence detection. Application to the characterization of cranberry-based pharmaceuticals through profiling and fingerprinting approaches
PublicationIn this work, a new method based on reversed-phase high-performance liquid chromatography (HPLC) with fluorescence detection (FLD) was established for the determination of catechins and related oligomeric proanthocyanidins (PACs) in cranberry-based pharmaceuticals. Compounds were recovered by liquid extraction using methanol/water/hydrochloric acid (60:39:1, v:v:v) as the extraction solvent. The chromatographic separation was carried...
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EVALUATION OF LIQUID-GAS FLOW IN PIPELINE USING GAMMA-RAY ABSORPTION TECHNIQUE AND ADVANCED SIGNAL PROCESSING
PublicationLiquid-gas flows in pipelines appear in many industrial processes, e.g. in the nuclear, mining, and oil industry. The gamma-absorption technique is one of the methods that can be successfully applied to study such flows. This paper presents the use of thegamma-absorption method to determine the water-air flow parameters in a horizontal pipeline. Three flow types were studied in this work: plug, transitional plug-bubble,...
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Multivariate Statistical Approach for Nephrines in Womenwith Obesity
PublicationCatecholamines are physiological regulators of carbohydrate and lipid metabolism during stress, but their chronic influence on metabolic changes in obese patients is still not clarified. The present study aimed to establish the associations between the catecholamine metabolites and metabolic syndrome (MS) components in obese women as well as to reveal the possible hidden subgroups of patients through hierarchical cluster analysis...
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Concentrations and loads of DOC, phenols and aldehydes in a proglacial arctic river in relation to hydro-meteorological conditions. A case study from the southern margin of the Bellsund Fjord – SW Spitsbergen
PublicationClimate warming accelerates the melting and thawing of cryosphere components. Therefore, it favours the release of contaminants stored in High-Arctic glaciers for many years. The rate of land-based glacier retreat is of particular importance for the hydrological regime of glacial rivers, but also for the chemical composition of their waters. In this study, we examined 84 surface water samples collected during a period of 42 days...
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Study on the Structure-Property Dependences of Rigid PUR-PIR Foams Obtained from Marine Biomass-Based Biopolyol
PublicationThe paper describes the preparation and characterization of rigid polyurethane-polyisocyanurate (PUR-PIR) foams obtained with biopolyol synthesized in the process of liquefaction of biomass from the Baltic Sea. The obtained foams differed in the content of biopolyol in polyol mixture (0–30 wt%) and the isocyanate index (IISO = 200, 250, and 300). The prepared foams were characterized in terms of processing parameters (processing...
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Typology of low developed non-metropolitan sub-regions in the European Union
PublicationThis paper shows a typology of 319 NUTS-3 sub-regions in the European Union. The selected sub-regions are non-metropolitan sub-regions, whose gross domestic product per capita in 2011 was below 75% of the EU average. The objective of this typology was to recognize diversity in the examined sub-regions as a starting point for the selection of areas for future comparative research. The typology takes into account 24 variables related...
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Music genre classification applied to bass enhancement for mobile technology
PublicationThe aim of this paper is to present a novel approach to the Virtual Bass Synthesis (VBS) algorithms applied to portable computers. The proposed algorithm is related to intelligent, rule-based setting of synthesis parameters according to music genre of an audio excerpt. The classification of music genres is automatically executed employing MPEG 7 parameters and the Principal Component Analysis method applied to reduce information...
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A nontargeted approach to determine the authenticity of Ginkgo biloba L. plant materials and dried leaf extracts by liquid chromatography-high-resolution mass spectrometry (LC-HRMS) and chemometrics
PublicationThe lack of stringent regulations regarding raw materials for herbal supplements used for medicinal purposes has been a constant challenge in the industry. Ginkgo biloba L. leaf extracts attract consumers because of the supposed positive effect on mental performance and memory. Supplements are produced using dried leaf materials and standardized leaf extracts such as EGb 761. Adulteration of Ginkgo biloba L. plants and extracts...
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Application of Electronic Nose Based on Fast GC for Authenticity Assessment of Polish Homemade Liqueurs Called Nalewka
PublicationThe possibility of application of electronic nose based on fast GC for differentiation of three types of cherry liqueurs, namely Polish homemade liqueurs called nalewka, commercially available liqueurs labeled as nalewka, and commercial liqueurs, was investigated. This device was equipped with two parallel connected columns with different stationary phases coupled to two ultrasensitive flame ionization detectors (μ-FIDs). Four...
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Application of the Electronic Nose Technique to Differentiation between Model Mixtures with COPD Markers
PublicationABSTRACT The paper presents the potential of an electronic nose technique in the field of fast diagnostics of patients suspected of Chronic Obstructive Pulmonary Disease (COPD). The investigations were performed using a simple electronic nose prototype equipped with a set of six semiconductor sensors manufactured by FIGARO Co. They were aimed at verification of a possibility of differentiation between model reference mixtures with...
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Evaluation of the suitability of electronic nose based on fast GC for distinguishing between the plum spirits of different geographical origins
PublicationPlum spirits are obtained exclusively via the alcoholic fermentation and distillation of meaty plums or must composed of plums, with or without stones. The European countries such as Poland, the Slovak Republic, the Czech Republic, Bulgaria and Romania are the leading producers of this alcoholic beverage. Information about the authentication of plum spirits produced in different countries can be found in the published literature....
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Fast GC as a useful tool for authenticity assessment of kiwifruit
PublicationKiwifruit is one of the healthiest fruits due to its high content of biologically active substances and nutrients. The most popular species of Actinidia (kiwifruit) are the Actinidia deliciosa fruits called kiwi and Actinidia chinensis commonly called golden kiwi, while the lesser known species is Actinidia arguta known as mini kiwi. Bioactivities and nutrients of Actinidia are influenced by species and cultivars. It is very important...
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Bass Enhancement Settings in Portable Devices Based on Music Genre Recognition
PublicationThe paper presents a novel approach to the Virtual Bass Synthesis (VBS) applied to mobile devices, called Smart VBS (SVBS). The proposed algorithm uses an intelligent, rule-based setting of bass synthesis parameters adjusted to the particular music genre. Harmonic generation is based on a nonlinear device (NLD) method with the intelligent controlling system adapting to the recognized music genre. To automatically classify music...
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The influence of reactions conditions on aggregation of dyes used in biochemistry
PublicationSelf-association of dyes and related substances is a very important phenomenon in many fields of applied chemistry. It is also fundamental model reaction of many kinds of molecular interactions such as the micelle formation of amphiphilic substances and the binding of small organic molecules to macromolecules. In spite of many studies concerning the dimerization equilibria of dyes and related substances, the mechanism seems not...
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Key-Marker Volatile Compounds in Aromatic Rice (Oryza sativa) Grains: An HS-SPME Extraction Method Combined with GC×GC-TOFMS
PublicationThe aroma of rice essentially contributes to the quality of rice grains. For some varieties, their aroma properties really drive consumer preferences. In this paper, using a dynamic headspace solid-phase microextraction (HS-SPME) system coupled to a two-dimensional gas chromatography (GC×GC) using a time-of-flight mass spectrometric detector (TOFMS) and multivariate analysis, the volatile compounds of aromatic and non-aromatic...
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Determination of Odour Interactions of Three-Component Gas Mixtures Using an Electronic Nose
PublicationThe paper presents an application of an electronic nose prototype comprised of six TGS-type sensors and one PID-type sensor to identify odour interaction phenomena in odorous three-component mixtures. The investigation encompassed eight odorous mixtures—toluene-acetone-triethylamine and formaldehyde-butyric acid-pinene — characterized by different odour intensity and hedonic tone. A principal component regression (PCR) calibration...