Environmetrical Treatment of Water Quality Survey Data from Yantra River, Bulgaria

 The environmetrical analysis carried out has indicated that the short-term water quality survey may give a very important information on the latent factors influencing the water quality of Yantra river basin. The principal components analysis carried out reveals that at least four principal components are necessary for multivariate statistical modeling of the water quality – combination of natural and anthropogenic influences (“mixed” factor) reflecting parameters such as water hardness, marine influence, organic pollution; typical anthropogenic influences (“anthropogenic” factor) explaining the metal contamination of the river water; everyday wastes, usually N-containing pollutants such as nitrates, nitrites or ammonia, form the “N-containing wastes” factor and a “temperature” factor formed by typical physical parameters such as water and air temperature. The formation of these special features of the river waters from Yantra basin is also confirmed by the results of cluster analysis (variable clustering) where the content of the significant clusters of the variables is the same as the content of the principal components modeling over 75% of the total variance of the system. Additionally, the cluster analysis of the objects has proved that the water quality during both sampling traverses is very stable and reproducible. Few exceptions are observed due to momentary local pollution in an industrial area along the river stream. Comparison with standard requirements for water quality has indicated that the Yantra river waters are of high quality and could be used after minor pretreatment as potable water sources. The environmetrical approaches applied reveal a specific information concerning the river water quality. In this way the ecological problem treated has not a local importance but suggests a strategy for estimation of similar ecosystems in global sense. Received July 30, 1998. Revision June 1, 1999.     

Chemometrics in the assessment of the sustainable development rule implementation

The sustainable development rule implementation is tested by the application of chemometrics in the field of environmental pollution. A data set consisting of Cd, Pb, Cr, Zn, Cu, Mn, Ni, and Fe content in bottom sediment samples collected in the Odra River (Germany/Poland) is treated using cluster analysis (CA), principal component analysis (PCA), and source apportionment techniques. Cluster analysis clearly shows that pollution on the German bank is higher than on the Polish bank. Two latent factors extracted by PCA explain over 88 % of the total variance of the system, allowing identification of the dominant “semi-natural” and “anthropogenic” pollution sources in the river ecosystem. The complexity of the system is proved by MLR analysis of the absolute principal component scores (APCS). The apportioning clearly shows that Cd, Pb, Cr, Zn and Cu participate in an “anthropogenic” source profile, whereas Fe and Mn are “semi-natural”. Multiple regression analysis indicates that for particular elements not described by the model, the amounts vary from 4.2 % (Mn) to 13.1 % (Cr). The element Ni participates to some extent to each source and, in this way, is neither pure “semi-natural” nor pure “anthropogenic”. Apportioning indicates that the whole heavy metal pollution in the investigated river reach is 12510.45 mg·kg⁻¹. The contribution of pollutants originating from “anthropogenic sources” is 9.04 % and from “semi-natural” sources is 86.53 %.     

Danube River Water Data Modelling by Multivariate Data Analysis

 A data set (48×19) consisting of Danube river water analytical data collected at Galati site, Romania, during a four-year period has been treated by principal components analysis (PCA). The PCA indicated that seven latent factors (“hardness”, “biochemical”, “waste inlets”, “turbidity”, “acidity”, “soil extracts” and “organic wastes”) are responsible for the data structure and explain over 80 % of the total variance of the system. Its complexity is further proved by the application of multiple linear regression analysis on the absolute principal components scores (APCS) where the contribution of each natural or anthropogenic sources in the factor formation is shown. The apportioning makes clear that each variable participates to a different extent to each source and, in this way, no pure natural or pure anthropogenic influence could be determined. No specific seasonality for the variables in consideration is found. Received January 24, 2001. Revision July 6, 2001.     

Assessment of Water Quality for Human Consumption

 This study deals with the application of chemometric approaches (cluster analysis and principal components analysis) to a potable water monitoring demonstrated on a data set from the region of Kavala, Greece, being analysed according to the standard instructions and directives of the European Union. It is shown that the data classification by cluster analysis and data structure modeling by principal components analysis reveals similar results, namely four different patterns of water source sites are identified depending on the geographical site location (near to Nestos river, near to Strimon river, elevated sites and near-to-coast sites). Three latent factors, explaining over 85% of the total variance, are responsible for the data structure as follows: “water acidity (anthropogenic)”, “water hardness (natural)” and the “marine factor”. Their importance for the different sites is related to the site location. Finally, it is recommended to involve the environmetric data treatment as a substantial standard procedure in assessment of the quality of water intended for human consumption. Received October 18, 2001; accepted June 24, 2002     

Contamination assessment of heavy metal in surface sediments of the Wuding River, northern China

The heavy metal contents and the contamination levels of the surface sediments of the Wuding River, northern China, were investigated. Heavy metal concentration ranged in μg g⁻¹: 50.15–71.91 for Cr, 408.1–442.9 for Mn, 20.11–43.59 for Ni, 17.51–20.1 for Cu, 68.32–89.57 for Zn, 0.2–0.38 for Cd and 15.08–16.14 for Pb in the Wuding River sediments. The enrichment factor (EF) and the geo-accumulation index (Igeo) demonstrated that the sediments of the Wuding River had been polluted by Cd, Cr and Ni, which mainly originated from anthropogenic sources, whereas the sediments had not been polluted by Zn, Pb, Cu and Mn, which were derived from the crust. In addition, the assessment results of EF and Igeo suggested that the sediments of the Wuding River was “moderately” polluted by Cd and “unpolluted to moderately” polluted by Cr and Ni. The elevated urban sewage discharges and agriculture fertilizers usage in river basin are the anthropogenic sources of these heavy metals in river.     

Multivariate analysis of HT/GC-(IT)MS chromatographic profiles of triacylglycerol for classification of olive oil varieties

The ability of multivariate analysis methods such as hierarchical cluster analysis, principal component analysis and partial least squares-discriminant analysis (PLS-DA) to achieve olive oil classification based on the olive fruit varieties from their triacylglycerols profile, have been investigated. The variations in the raw chromatographic data sets of 56 olive oil samples were studied by high-temperature gas chromatography with (ion trap) mass spectrometry detection. The olive oil samples were of four different categories (“extra-virgin olive oil”, “virgin olive oil”, “olive oil” and “olive-pomace” oil), and for the “extra-virgin” category, six different well-identified olive oil varieties (“hojiblanca”, “manzanilla”, “picual”, “cornicabra”, “arbequina” and “frantoio”) and some blends of unidentified varieties. Moreover, by pre-processing methods of chemometric (to linearise the response of the variables) such as peak-shifting, baseline (weighted least squares) and mean centering, it was possible to improve the model and grouping between different varieties of olive oils. By using the first three principal components, it was possible to account for 79.50% of the information on the original data. The fitted PLS-DA model succeeded in classifying the samples. Correct classification rates were assessed by cross-validation.     

Lateral flow (immuno)assay: its strengths,weaknesses, opportunities and threats. A literature survey

Lateral flow (immuno)assays are currently used for qualitative, semiquantitative and to some extent quantitative monitoring in resource-poor or non-laboratory environments. Applications include tests on pathogens, drugs, hormones and metabolites in biomedical, phytosanitary, veterinary, feed/food and environmental settings. We describe principles of current formats, applications, limitations and perspectives for quantitative monitoring. We illustrate the potentials and limitations of analysis with lateral flow (immuno)assays using a literature survey and a SWOT analysis (acronym for “strengths, weaknesses, opportunities, threats”). Articles referred to in this survey were searched for on MEDLINE, Scopus and in references of reviewed papers. Search terms included “immunochromatography”, “sol particle immunoassay”, “lateral flow immunoassay” and “dipstick assay”.     

How chemistry shifts horizons: element, substance, and the essential

In 1931 eminent chemist Fritz Paneth maintained that the modern notion of “element” is closely related to (and as “metaphysical” as) the concept of element used by the ancients (e.g., Aristotle). On that basis, the element chlorine (properly so-called) is not the elementary substance dichlorine, but rather chlorine as it is in carbon tetrachloride. The fact that pure chemicals are called “substances” in English (and closely related words are so used in other European languages) derives from philosophical compromises made by grammarians in the late Roman Empire (particularly Priscian [fl. ~520 CE]). When the main features of the constitution of isotopes became clear in the first half of the twentieth century, the formal (IUPAC) definition of a “chemical element” was changed. The features that are “essential” to being an element had previously been “transcendental” (“beyond the sphere of consciousness”) but, by the mid-twentieth century the defining characteristics of elements, as such, had come to be understood in detail. This amounts to a shift in a “horizon of invisibility” brought about by progress in chemistry and related sciences. Similarly, chemical insight is relevant to currently-open philosophical problems, such as the status of “the bundle theory” of the coherence of properties in concrete individuals.

Evaluation of high-performance liquid chromatography for determination of phenolic compounds in pear horticultural cultivars

Summary An analytical evaluation of an HPLC method with diode array detection to separate and quantify polyphenolic compounds from pears has been made. The method was applied to the quantitative analysis of phenolics from five pear horticultural cultivars (“Agua”, “Blanquilla”, “Conference”, “Pasagrana” and “Decana”) in both peel and pulp matrices and evaluated for precision and accuracy. Precision was taken as the reproducibility in peak area of the polyphenols of interest as well as in the slope of calibration graphs. Values ranged 2–5%. Accuracy was evaluated by recovery of all polyphenolic compounds from both peel and pulp in all pears investigated. Accuracy values ranged 92–102%, and were independent of the polyphenolic structure, horticultural cultivar and matrix. Identification was by comparing retention times and UV spectra with those of standards when commercially available. When not available commercially, provisional identification was according to spectral characteristics as well as from isolation and hydrolysis data. Application of the method revealed differences between peel and pulp in all cases studied; the higher levels of phenolics were found in the peels. “Decana” and “Pasagrana” cultivars showed the highest phenolic content compounds whereas “Conference” showed the lowest.     

Interplay of Thermochemistry and Structural Chemistry,the Journal (Volume 14, 2003) and the Discipline

As practiced disciplines, structural chemistry and thermochemistry need not be related. In the current study, the relation is made more evident from among the contents of the journal “Structural Chemistry” (Vol. 14) for the year 2003. The year's articles have been reviewed, giving to most of those appearing therein a thermochemical commentary, “spin” or “slant.”     

Linearly polarized white fluorescence from shish-kebab type liquid crystalline poly(P-phenylenevinvlene)s with (P-phenylene)s as kebab

Liquid crystalline(LC) polymers with a shish-kebab-type moiety on their cross-conjugated(p-phenylene)s-poly(p-phenylenevinylene) s main chains were synthesized through Gilch polymerization in order to develop a kind of polymers available for linearly polarized white-light-emitting from single chain.In this system,the 2,5-bis(4’-alkoxyphenyl)benzene as the "kebabs" connects with poly(p-phenylenevinylene)(PPV) main chain backbone using its molecular gravity center and the PPV as the "shish" or "skewer"(the "shish-kebab").The polymers possess desirable properties such as excellent solubility and liquid crystalline properties.To drop the "kebabs" of the 2,5-bis(4’-alkoxyphenyl)benzene into the orientation microgroove of aligned polyimide film,not only the "shish" of polymer main chain can be aligned by the virtue of orientation of "kebabs" but also the uniform cross-conjugated structure between the "kebabs" and "shish" can be broken. Then,the alignment of the polymer main chain showed yellow light emission and was also accompanied by orientation of the LC side chains showing blue light emission,this gave rise to a notable linearly polarized white fluorescence.     

Synthesis and aromatizational rearrangements of new imino-, hydrazono-, and azino-2,5-cyclohexadienylidene systems as ligands for cascade type metallocomplexes

Three approaches to the synthesis ofN-substituted imino-, hydrazono-, and azino-2,5-cyclohexadienylidene systems based on reactions of 4-methyl-4-trichloromethylcyclohexa-2,5-dienone with aminophenols and hydrazones and condensation of hydrazones ofpara-semiquinoid ketones with carbonyl compounds, including that of the ferrocene series, were realized. The latter reaction, when applied to 3,6-dibromophenanthrene-9, 10-quinone, was accompanied by quantitative aromatizational molecular rearrangement with the elimination of the CCl₃ group. Using Rh¹ complexes as an example, it was shown that the heteroorganic ligands obtained can be used for the synthesis of mixed-ligand metallocomplexes with triple coordination of the metal atom including simultaneous metal-ligand interactions of the n-, π-, and σ-types. The principle of metal-ligand “cascade” appeared as a result of the generalization of two new phenomena of organometallic sereodynamics, which we have found recently^2,3 and have called oxidative and reductive redox-rotation. In the “cascade”, type1 (“metal-ligand-metal”) or type2 (“ligand-metal-ligand”) metallocomplexes, one or several coordinated metal ligand”) metallocomplexes, one or several coordinated metal atoms capable of concertedly and reversibly changing their valence in the course of intramolecular conformational transformation are in positions of mutual conjugation. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 363–367, February, 1997.     

Matrix effect for several derivatives of benzene in water by solid phase microextraction (SPME)

Summary Levels of several derivatives of benzene were examined in natural surface water (river Zala, West-Hungary) by solid phase micro extraction. Results from the river water samples were compared to the results from spiked double distilled water. The difference in extraction efficiency is termed a “matrix effect”. Large matrix effect causing the change of extraction efficiency experienced in this study. Relationship was found between the matrix effect and TOC, TIC, suspended and the dissolved matter content. Presented at Balaton Symposium on High Performance Methods, Siófok, Hungary, September, 1–3, 1999     

From Top-Down to Bottom-Up to Hybrid Nanotechnologies: Road to Nanodevices

The current development and future prospects of nanotechnology are discussed with special emphasis on the pros and cons of the “bottom-up” and “top-down” approaches to nanotechnology, and the eventual merging of the two, at the scale of about 30 nm in feature size, to form a new “hybrid” technology. At the scale of about 3 nm in feature size, this “hybrid” technology will be challenged by the emerging “supramolecular” and “molecular” technologies epitomized by large-scale integration of single-molecule devices. Ultimately the “supramolecular” and “molecular” technologies will yield to “atomic” or “nuclear” technologies at the dimension of below 0.3 nm whereby single-atom, single-electron, single-spin, single-photon devices become realities.     

Effect of metallic cobalt particles size on occurrence of CO disproportionation. Role of fluidized metallic cobalt-carbon solution in carbon nanotube formation

The behavior of Co−MgO catalysts in the reaction of CO disproportionation was studied in the temperature range up to 800°C. Two temperature regions that differ by the morphology of graphite produced (“egg-shells” or nanotubes) were detected. The experimental data obtained were analyzed in terms of the phase equilibria “amorphous carbon”—“carbon solution in metallic Co” and “graphite”— “carbon solution in metallic Co”. Under certain assumptions, the Co° particles are considered to dissolve amorphous carbon under the reaction conditions and transform to oversaturated fluidized carbon-cobalt solution, these fluidized particles being responsible for the formation of carbon nanotubes.     

Multivariate statistical analysis of coastal sediment data

Multivariate statistical analysis of sediment data (information matrix 123 × 16) from the Gulf of Mexico, USA shows that the data structure is defined by four latent factors conditionally called “inorganic natural”, “inorganic anthropogenic”, “bioorganic” and “organic anthropogenic” explaining 39.24%, 23.17%, 10.77% and 10.67% of the total variance of the data system, respectively. The receptor model obtained by the application of the PCR approach makes it possible to apportion the contribution of each chemical component for the latent factor formation. A separation of the contribution of each chemical parameter is achieved within the frames of “natural” and “anthropogenic” origin of the respective heavy metal or organic matter to the sediment formation process. This is a new approach as compared to the traditional “one dimensional” search with a limited number of preliminary selected tracer components. The model suggested divides natural from anthropogenic influences and allows in this way each participant in the sediment formation process to be used as marker of either natural or anthropogenic effects. Received: 20 March 1999 / Revised: 1 June 1999 / Accepted: 3 June 1999     

Multivariate statistical analysis of coastal sediment data

Multivariate statistical analysis of sediment data (information matrix 123 × 16) from the Gulf of Mexico, USA shows that the data structure is defined by four latent factors conditionally called “inorganic natural”, “inorganic anthropogenic”, “bioorganic” and “organic anthropogenic” explaining 39.24%, 23.17%, 10.77% and 10.67% of the total variance of the data system, respectively. The receptor model obtained by the application of the PCR approach makes it possible to apportion the contribution of each chemical component for the latent factor formation. A separation of the contribution of each chemical parameter is achieved within the frames of “natural” and “anthropogenic” origin of the respective heavy metal or organic matter to the sediment formation process. This is a new approach as compared to the traditional “one dimensional” search with a limited number of preliminary selected tracer components. The model suggested divides natural from anthropogenic influences and allows in this way each participant in the sediment formation process to be used as marker of either natural or anthropogenic effects. Received: 20 March 1999 / Revised: 1 June 1999 / Accepted: 3 June 1999     

Sol-Gel Microsphere Pelletisation Process for Fabrication of (U,Pu)O2, (U,Pu)C and (U,Pu)N Fuel Pellets for the Prototype Fast Breeder Reactor in India

A “dust-free” sol-gel microsphere pelletisation (SGMP) process has been developed for fabrication of (U,Pu)O₂, (U,Pu)C and (U,Pu)N fuel pellets containing around 15% plutonium for the forthcoming prototype fast breeder reactor (PFBR) in India. The objective was to produce homogeneous sintered pellets of ∼85% T.D. with a predominantly open-pore structure. Hydrated gel-microspheres of UO₃+PuO₂ and UO₃+PuO₂+C have been prepared from nitrate solutions of uranium and plutonium by the “ammonia internal gelation” process, using hexamethylene tetramine (HMTA) as an ammonia generator and silicone oil at 90±1°C as gelation bath. For oxide fuel pellets, the hydrated UO₃+PuO₂ gel-microspheres were calcined at around 700°C in Ar+8% H₂ atmosphere to produce “non-porous”, “free-flowing” and coarse (around 400 micron) microspheres which could be directly pelletised at 550 MPa to green pellets. The mixed oxide pellets were subjected either to low temperature (∼1100°C) oxidative sintering (LTS) in N₂+air containing ∼1500 ppm O₂ or to high temperature (1650°C) sintering, (HTS) in Ar+8% H₂. For monocarbide and mononitride pellets, hydrated gel-microspheres of UO₃+PuO₂+C were subjected to carbothermic synthesis in vacuum (∼1 Pa) and flowing nitrogen (flow rate: 1.2 m³/h) in the temperature range of 1450–1550°C respectively. The monocarbide and mononitride microspheres thus produced were relatively hard and required higher compaction pressure (∼1200 MPa) for making reen pellets which could be sintered to 85% T.D. in Ar+8% H₂ at 1700°C. The sintered oxide, monocarbide and mononitride pellets had a “blackberry” “open” pore microstructure with fine grain size. The microspheres retained their individual identity in the sintered pellets because during sintering densification took place mainly within and not between the microspheres.     

Toxicity of Methanol and Formaldehyde Towards <Emphasis Type="Italic">Saccharomyces cerevisiae</Emphasis> as Assessed by DNA Microarray Analysis

To assess the toxicity of the C1 compounds methanol and formaldehyde, gene expression profiles of treated baker’s yeast were analyzed using DNA microarrays. Among approximately 6,000 open reading frames (ORFs), 314 were repressed and 375 were induced in response to methanol. The gene process category “energy” comprised the greatest number of induced genes while “protein synthesis” comprised the greatest number of repressed genes. Products of genes induced by methanol were mainly integral membrane proteins or were localized to the plasma membrane. A total of 622 and 610 ORFs were induced or repressed by formaldehyde, respectively. More than one-third of the genes found to be strongly repressed by formaldehyde belonged to the “protein synthesis” functional category. Conversely, genes in the subcategory of “nitrogen, sulfur, and selenium metabolism” within “metabolism” and in the category of “cell rescue, defense, and virulence” were up-regulated by exposure to formaldehyde. Our data suggest that membrane structure is a major target of methanol toxicity, while proteins were major targets of formaldehyde toxicity.     

Reactions of 4-tosyl-2-phenyl-5-chloro-1,3-thiazole with N-, O-, and S-nucleophiles

The accessible two-center electrophilic substrate 4-tosyl-2-phenyl-5-chloro-1,3-thiazole reacts regioselectively with N-, O-, and S-nucleophiles to eliminate a chloride ion. The analog of this substrate, 4-tosyl-2-phenyl-5-p-chlorophenylsulphonyl-1,3-thiazole, reacts with “soft” and “hard” nucleophiles differently: with the participation of C⁵ or C⁴ center, respectively, that seems to be caused by the principle of “symbiosis” in the transition state.