Adam Smoliński

Hierarchical clustering extended with visual complements of environmental data set

Hierarchical clustering techniques complemented with visual display of data sets allow direct interpretation of the clustering results in terms of original variables. The proposed method of data ordering and display is simple, informative and fulfils fundamental objectives of the data visualisation techniques. In our study, it is applied for exploratory analysis of an environmental data set.

Exploratory analysis of data sets with missing elements and outliers.

The main goal of the presented paper was to develop a general strategy allowing exploration of contaminated data sets with missing elements, based on application of robust PLS for initial estimation of missing elements. Using robust distance, the outlying elements were identified. After their identification and replacing by missing elements, the expectation-maximization algorithm (which can be built in into different computational procedures, such as principal component analysis and its generalisation to the N-way data-the TUCKER3 model) was used for construction of the final model.

Chemometric Study of the Ex Situ Underground Coal Gasification Wastewater Experimental Data.

The main goal of the study was the analysis of the parameters of wastewater generated during the ex situ underground coal gasification (UCG) experiments on lignite from Belchatow, and hard coal from Ziemowit and Bobrek coal mines, simulated in the ex situ reactor. The UCG wastewater may pose a potential threat to the groundwater since it contains high concentrations of inorganic (i.e., ammonia nitrogen, nitrites, chlorides, free and bound cyanides, sulfates and trace elements: As, B, Cr, Zn, Al, Cd, Co, Mn, Cu, Mo, Ni, Pb, Hg, Se, Ti, Fe) and organic (i.e., phenolics, benzene and their alkyl derivatives, and polycyclic aromatic hydrocarbons) contaminants. The principal component analysis and hierarchical clustering analysis enabled to effectively explore the similarities and dissimilarities between the samples generated in lignite and hard coal oxygen gasification process in terms of the amounts and concentrations of particular components. The total amount of wastewater produced in lignite gasification process was higher than the amount generated in hard coal gasification experiments. The lignite gasification wastewater was also characterized by the highest contents of acenaphthene, phenanthrene, anthracene, fluoranthene, and pyrene, whereas hard coal gasification wastewater was characterized by relatively higher concentrations of nitrites, As, Cr, Cu, benzene, toluene, xylene, benzo(a)anthracene, chrysene, benzo(b)fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene.

Chemometric characterization of s-triazine derivatives in relation to structural parameters and biological activity

Objective: In this study 14 newly synthesized s-triazine derivatives were investigated by means of reversed-phase thin-layer chromatography (TLC) on C-18 stationary and five different mobile phases: acetone–water, acetonitrile–water, methanol–water, 2-propanol–water, and tetrahydrofuran–water. Methods: Principal component analysis (PCA) was performed to explore and visualize similarities and differences among the compounds and among the mobile phases. Observations from the PCA were supported using hierarchical cluster analysis (HCA). Results: Physicochemical parameters that are significant for activity, that is, absorption, distribution, and bonding for different receptors in target tissues were calculated. Conclusion: Highly predictive models, describing quantitative relationships between chromatographic retention and parameters that influence activity, were obtained using partial least squares (PLS) method.

Chemometric study of trace elements in hard coals of the upper Silesian Coal Basin, Poland.

The objective of the study was the analysis of trace elements contents in coals of the Upper Silesian Coal Basin (USCB), which may pose a potential threat to the environment when emitted from coal processing systems. Productive carbon overburden in central and southern zones of the USCB is composed mostly of insulating tertiary formations of a thickness from a few m to 1,100 m, and is represented by Miocene and Pliocene formations. In the data study the geological conditions of the coal seams of particular zones of the USCB were taken into account and the hierarchical clustering analysis was applied, which enabled the exploration of the dissimilarities between coal samples of various zones of the USCB in terms of basic physical and chemical parameters and trace elements contents. Coals of the northern and eastern zones of the USCB are characterized by high average Hg and low average Ba, Cr, and Ni contents, whereas coals of southern and western zones are unique due to high average concentrations of Ba, Co, Cu, Ni, and V. Coals of the central part of the USCB are characterized by the highest average concentration of Mn and the lowest average concentrations of As, Cd, Pb, V, and Zn.

Robust Multivariate Calibration in Environmental Studies

Abstract The main goal of this article is to present a strategy how to deal with multidimensional environmental data sets containing outliers. For calibration purposes we recommend the robust Partial Least Squares (rPLS) method, which can well describe data majority not influenced by outlying observations. This method is used to describe quantitative relationships between concentration profiles of metals measured for sediments and the parameters analyzed in water in the Saale river.

Chemometric study of biological activities of 10 aromatic Lamiaceae species' essential oils

The application of chemometric approaches in the comparison of the activity and the chemical composition of essential oils of 10 aromatic Lamiaceae species (Melissa officinalis, Mentha piperita, Mentha aquatica, Mentha longifolia, Ocimum basilicum, Origanum vulgare, Rosmarinus officinalis, Salvia officinalis, Salvia nemorosa, and Thymus vulgaris) is reported in this paper. The standard methodology of principal component analysis needs too many principal components (PCs) to effectively describe the relationships between studied samples. PC1 explains only 47.58% of the total variance reflecting the most significant differences between essential oils of S. nemorosa and Or. vulgare. PC2 explains 19.77% of the total variance and shows the most significant differences between the essential oils of M. aquatica compared with those of S. nemorosa, S. officinalis and Or. vulgare. Efficient compression of the data was possible by hierarchical clustering analysis (HCA) complemented with a color map. HCA shows that essential oils of both investigated representatives of genus Salvia are characterized by a high content of oxygenated sesquiterpenes and remarkable antifungal activities, but low antibacterial and antioxidant activity, particularly for the S. officinalis. Unlike sage, the essential oils of oregano and thyme have high content of aromatic oxygenated monoterpenes and low antifungal but pronounced antibacterial activity. Peppermint, basil, rosemary, and lemon balm are characterized by high content of oxygenated monoterpenes and aliphatic components as well as by high antioxidant 2,2‐diphenyl‐1‐picrylhydrazil activity of essential oils. Copyright

Chemometric Study of the Antiproliferative Activity of Some New Hydantoin Derivatives: Assessment of Activity and Chromatographic Lipophilicity Data

Cancer is the major health problem affecting the mankind of today. Most of the drugs used in traditional chemotherapy are very limited and the discovery of novel, more active, more selective and less toxic ones is still very intensive. A chemometric approach was applied in the study of antiproliferative activity against human colon cancer and breast cancer as well as in the study of lipophilicity of 3-(4-substituted benzyl)-5-ethyl-5-phenyl- and 3-(4-substituted benzyl)- 5,5-diphenylhydantoins. Hierarchical clustering analysis (HCA) shows that the investigated hydantoins have higher antiproliferative activity against human breast cancer cells than against human colon cancer cells. However, some hydantoins at the highest applied concentration reverse antiproliferative effect, higher against the human colon cancer cells and lower against human breast cancer cells. Principal component analysis (PCA) gives better insight into the activity of hydantoins related to their structural changes. It distinguishes more active compounds from the less active ones according to various criteria. Generally, more lipophilic 5,5-diphenylhydantoins exhibit a higher antiproliferative activity comparing to less lipophilic 5-ethyl-5-phenylhydantoins. Also, a substituent attached to benzyl moieties affects the activity additionally. The activity is particularly pronounced for compounds with cyano, methyl, chloro and bromo group. Halogen substituent were superior in antiproliferative capacity particularly in the series of 5,5-diphenylhydantoins.

Chemometric study of retention indices of some thiazolidinediones derivatives in two low polarity stationary phases.

Application of chemometric methods in the study of the retention indices of thirteen 5-arylidene-2,4- thiazolidinediones in two low polarity high-performance thin-layer chromatographic (HPTLC) stationary phases (RP-18 and RP-CN) and six aqueous mobile phases. Principal component analysis classified chromatographic systems into four specific groups while one system remained non-classified. Hierarchical clustering analysis enabled grouping of the chromatographic systems into three clusters, and the studied compounds into three main classes. The color map enabled more in-depth interpretation of the relationships between the studied compounds and HPTLC systems applied.

THE INFLUENCE OF FEEDSTOCK TYPE AND OPERATING PARAMETERS ON TAR FORMATION IN THE PROCESS OF GASIFICATION AND CO-GASIFICATION

Abstract Increasing energy demand, limited resources of fossil fuels and environmental aspects are the main rationales of the research efforts aiming at wider utilization of renewable resources and waste in energy generation systems. Gasification technologies are based on thermochemical processing of solid, liquid and gaseous fuels to gas of the composition dependent on kind of gasification agent and operating parameters used. The range of applications of the product gas includes basically chemical and petrochemical industries. Its utilization in power generation systems is also of industrial interest since the environmental impact of gasification technologies is lower and the process efficiency is higher than of coal-fired power plants and it enables to utilize wide range of fuels, including fossil fuels, biomass, industrial waste and various fuel blends. One of the most important operational issues related with thermochemical processing of biomass and waste is the formation of tars, which reduces the energy efficiency of the process and causes technical problems in a system operation. The amount and quality of tars depends on the chemical composition of a fuel, a gasification agent used and its ratio to fuel flow, process temperature and pressure as well as the construction of a gasifier. In the paper review of the research on the influence of operating parameters and kind of feedstock on tar formation and composition in the process of gasification and co-gasification is presented. Abstrakt Rosnące zapotrzebowanie na energię, ograniczone zasoby surowców energetycznych oraz aspekty środowiskowe stanowią główną przyczynę prac badawczych, których celem jest szersze użytkowanie odnawialnych źródeł energii oraz odpadów do celów energetycznych. Technologie zgazowania oparte są na procesie termochemicznej przeróbki paliw stałych, płynnych i gazowych do gazu o składzie zależnym od zastosowanego czynnika zgazowującego i wartości parametrów eksploatacyjnych. Zakres zastosowania produktu gazowego z procesu zgazowania obejmuje głównie przemysł chemiczny i petrochemiczny. Jego zastosowanie w produkcji energii elektrycznej również jest interesujące z uwagi na mniejszy negatywny wpływ technologii zgazowania na środowisko i większą sprawność procesu w porównaniu z systemami kotłów węglowych. Technologie zgazowania umożliwiają również użytkowanie różnych surowców energetycznych, począwszy od paliw kopalnych poprzez biomasę, odpady przemysłowe i różne mieszanki wsadowe. Jednym z najbardziej istotnych aspektów eksploatacyjnych związanych z przetwarzaniem termochemicznym biomasy i odpadów jest tworzenie się substancji smolistych, co obniża sprawność energetyczną procesu i powoduje problemy techniczne w eksploatacji instalacji. Charakterystyka ilościowa i jakościowa substancji smolistych uwarunkowana jest składem chemicznym paliwa, rodzajem czynnika zgazowującego i wartością stosunku natężenia przepływu tego czynnika do nadawy paliwa, temperaturą oraz ciśnieniem procesu, a także rodzajem zastosowanej konstrukcji reaktora. W pracy przedstawiono przegląd badań w zakresie wpływu parametrów eksploatacyjnych oraz rodzaju paliwa na ilość i skład substancji smolistych w procesie zgazowania i współzgazowania.