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The current work studies the reductive catalytic depolymerization (RCD) of lignin from a novel semi-industrial process. The aim was to obtain aromatic mono-, di-, tri-, and tetramers for further valorization. The substrate and products were characterized by multiple analytical methods, including high pressure size-exclusion chromatography (HPSEC), gas chromatography–mass spectrometry, GC-flame ionization detector (FID), GC-FID/thermal conductivity detector (TCD), and NMR. The RCD was studied by exploring the influence of different parameters, such as lignin solubility, reaction time, hydrogen pressure, reaction temperature, pH, type and loading of the catalyst, as well as type and composition of the organic/aqueous solvent. The results show that an elevated temperature, a redox catalyst, and a hydrogen atmosphere are essential for the depolymerization and stability of the products, while the reaction medium also plays an important role. The highest obtained mono- to tetramers yield was 98% and mono- to dimers yield over 85% in the liquid phase products. The reaction mechanisms influenced the structure of the aliphatic chain in the monomers, but left the phenolic structure along with the methoxy groups largely unaltered. The current work contributes to the development and debottlenecking of the novel and sustainable overall process, which utilizes efficiently all the fractions of wood, in line with the principles of green engineering and chemistry.

Aerobic Pd(AcO)2/pyridine-catalyzed oxidation of unprotected carbohydrate-based terminal alkenes was studied. In accordance with previous reports, the initial reaction step gave methyl ketones. However, our substrates partially gave subsequent α,β-water elimination and alcohol oxidation to α,β-unsaturated 2,5-diketones. Upon increasing the pressure of O2, the reaction was shifted toward formation of α,β-epoxy-2-ketones. The reactions were stereoselective and gave up to quantitative conversions. However, isolated yields were substantially lower because of the complexity of the product mixtures.

As a significant role for traffic management, city planning, road monitoring, GPS navigation and map updating, the technology of road extraction from a remote sensing (RS) image has been a hot research topic in recent years. In this paper, after analyzing different road features and road models, the road extraction methods were classified into the classification-based methods, knowledge-based methods, mathematical morphology, active contour model, and dynamic programming. Firstly, the road features, road model, existing difficulties and interference factors for road extraction were analyzed. Secondly, the principle of road extraction, the advantages and disadvantages of various methods and research achievements were briefly highlighted. Then, the comparisons of the different road extraction algorithms were performed, including road features, test samples and shortcomings. Finally, the research results in recent years were summarized emphatically. It is obvious that only using one kind of road features is hard to get an excellent extraction effect. Hence, in order to get good results, the road extraction should combine multiple methods according to the real applications. In the future, how to realize the complete road extraction from a RS image is still an essential but challenging and important research topic.

The fragmentation pattern of 30 compounds belonging to different classes of the lignan family was studied by liquid chromatographyelectrospray ionization iontrap mass spectrometry. On the basis of the observed fragmentation patterns, identification of different types of lignans was achieved. For example, dibenzylbutyrolactone lignans showed a characteristic fragmentation pathway by the loss of 44 Da CO2 from the lactone moiety, whereas dibenzylbutanediols showed a loss of 48 Da by a combined loss of formaldehyde and water from the 1,4butanediol moiety. Lignan glycosides readily lost the sugar residue to give the parent lignan as their primary product ion. In addition, several compoundspecific fragmentations were observed and used for identification of individual compounds.A versatile method for analyses of lignans was developed using LC separation on a C8 column followed by fragmentation and detection of ions produced in the ion trap. Copyright © 2007 John Wiley & Sons, Ltd.

Recent research in our group has revealed that knots, i.e. the branch bases inside tree stems, commonly contain 5–10% (w/w) of lignans. Norway spruce (Picea abies) knots contain as much as 6–24% of lignans, with 7-hydroxymatairesinol (HMR) as the predominant (70–85%) lignan. Some other spruce species also contain HMR as the main lignan, but some spruce species have also other dominating lignans. Most fir (Abies) species contain secoisolariciresinol and lariciresinol as the main lignans. Lignans occur also in knots of pines (Pinusspp.), although in lower amounts than in spruces and firs. Scots pine (Pinus silvestris) knots were found to contain 0.4–3% of lignans with nortrachelogenin as the main lignan. Lignans have been identified also in knots of some hardwoods, although flavonoids are more abundant in hardwoods. Knots are detrimental in the manufacture of pulp and paper and should preferably be removed before pulping. This is possible using a recently developed industrially applicable process called ChipSep. Recent research has also established novel synthetic routes to several lignans, such as matairesinol, secoisolariciresinol, lariciresinol and cyclolariciresinol, starting from hydroxymatairesinol by applying fairly straight-forward chemical transformations. We conclude that wood knots in certain spruce and fir species constitute the richest known source of lignans in nature. The lignans occur in knots in free form and are easily extracted by aqueous ethanol, or even by water. Not only HMR, but also other potentially valuable lignans, could be produced in a scale of hundreds of tons per year by extraction of knots separated from wood chips at pulp and paper mills.

C-calculus is a method for combining less descriptive information for larger sets to obtain detailed descriptions about smaller sets. This is achieved by iteratively taking products of information in the form of C-sets. A sequential model for implementing the C-calculus for applications in digitized imaging is presented. The sequential model is a base for a parallel implementation, which is measured for efficiency and applicability

In this paper we investigate topologies with ultrafilters having bases of open sets. It is shown that these topologies are completely regular. All results are obtained by using Richardson's compactification of convergence spaces. We also prove a non-existance of a dense convergence space compactification with lifting property.

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In this paper we investigate topologies with ultrafilters having bases of open sets. It is shown that these topologies are completely regular. All results are obtained by using Richardson's compactification of convergence spaces. We also prove a non-existance of a dense convergence space compactification with lifting property.