Evaluation of antimicrobial activity and toxic potential of extracts and triterpenes isolated from Maytenus imbricata

The phytochemical study of hexane/ethyl ether (1:1) extract of the roots of M. imbricata, Celastraceae, resulted in the isolation and characterization of six known triterpenes: 11α-hydroxylup-20(29)-en-3-one, previously isolated from this species besides, 3β,11α-di-hydroxylup-20(29)-ene, 3,7-dioxofriedelane, 3-oxo-29-hydroxyfriedelane, tingenone and 6-oxo-tingenol. The chemical structures of these triterpenes were established by spectrometric data (IR, ¹H and 13C NMR) and through comparison with literature data. The hexane/ethyl ether (1:1), ethyl acetate and methanol extracts, and 11α-hydroxylup-20(29)-en-3-one, tingenone and 6-oxo-tingenol, showed antimicrobial properties on in vitro assays. All extracts and triterpenes, except 3β,11α-di-hydroxylup-20(29)-ene, presented toxicity demonstrated by the larvicidal effect test using Artemia salina.

Tropical biodiversity: has it been a potential source of secondary metabolites useful for medicinal chemistry?

The use of natural products has definitely been the most successful strategy in the discovery of novel medicines. Secondary metabolites from terrestrial and marine organisms have found considerable use in the treatment of numerous diseases and have been considered lead molecules both in their natural form and as templates for medicinal chemistry. This paper seeks to show the great value of secondary metabolites and emphasize the rich chemical diversity of Brazilian biodiversity. This natural chemical library remains understudied, but can be a useful source of new secondary metabolites with potential application as templates for drug discovery.

Chemical characterization by GC-MS and phytotoxic potential of non-polar and polar fractions of seeds of Dioteryx odorata (Aubl.) Willd. from Venezuelan regions

Dipteryx odorata (Aubl.) Willd. is a tall arboreal species native to Central and Northern South America. This paper describes the chemical characterization and phytotoxic potential of polar and non-polar extracts from D. odorata seeds. Structural determinations were accomplished by chemical derivatization and analyzed by GC/MS. The chemical composition of the non-polar fraction (hexane and dichloromethane) presented fatty acids as major constituent. Medium polar and polar fractions (ethyl acetate and ethanol: water) contained carboxylic acid and high 6,7-Dyhidroxycoumarin-β-D-glucopyranoside content, not previously reported for seeds of D. odorata. Extracts showed a significant level of phytotoxic activity, correlated to the content of coumarin derivatives, predominantly in the polar fraction.

A Theoretical investigation of a potential high energy density compound 3,6,7,8-tetranitro-3,6,7,8-tetraaza-tricyclo[3.1.1.1(2,4)]octane

The B3LYP/6-31G (d) density functional theory (DFT) method was used to study molecular geometry, electronic structure, infrared spectrum (IR) and thermodynamic properties. Heat of formation (HOF) and calculated density were estimated to evaluate detonation properties using Kamlet-Jacobs equations. Thermal stability of 3,6,7,8-tetranitro-3,6,7,8-tetraaza-tricyclo [3.1.1.1(2,4)]octane (TTTO) was investigated by calculating bond dissociation energy (BDE) at the unrestricted B3LYP/6-31G(d) level. Results showed the N-NO2 bond is a trigger bond during the thermolysis initiation process. The crystal structure obtained by molecular mechanics (MM) methods belongs to P2(1)/C space group, with cell parameters a = 8.239 Å, b = 8.079 Å, c = 16.860 Å, Z = 4 and r = 1.922 g cm-3. Both detonation velocity of 9.79 km s-1 and detonation pressure of 44.22 GPa performed similarly to CL-20. According to the quantitative standards of energetics and stability, TTTO essentially satisfies this requirement as a high energy density compound (HEDC).

Method for determining the photocatalytic potential of portland cement mortar containing TiO2 for decomposing the pollutant nitrogen monoxide

Photocatalytic materials can minimize atmospheric pollution by decomposing certain organic and inorganic pollutants using sunlight as an energy source. In this paper, the development of a methodology to measure the photocatalytic potential of mortar containing TiO2 nanoparticles is reported. The results indicate that up to 40% of NOx can be degraded by Portland cement mortar containing 30-50% of TiO2, which validates the method developed for evaluating the photocatalytic potential of materials.

Potential of non-pathogenic Fusarium oxysporum isolates for control of Fusarium wilt of tomato

This study was done to evaluate the efficiency of non-pathogenic Fusarium oxysporum isolates (141/3, 233, 233/1, 245, 245/1, 251, 251/2, 251/5, and 257) in controlling vascular wilt caused by F. oxysporum f. sp. lycopersici, race 2 (isolates C-21A, TO11, and TO245) in tomato (Lycopersicon esculentum) cv. Viradoro seedlings. In order to determine the effect of non-pathogenic F. oxysporum isolates in tomato plants, the root system of 30-day-old seedlings was immersed in conidial suspensions (10(6) ml-1) of each isolate and the seedlings were transplanted to a cultivation substrate. Thirty-five days after transplanting it was observed that the non-pathogenic F. oxysporum isolates were not pathogenic to the cv. Viradoro nor did they affect seedling development. The efficiency of the non-pathogenic F. oxysporum isolates in controlling Fusarium wilt was determined by immersing the tomato seedling roots in the conidial suspension (10(6) ml-1) of each isolate and then transplanting them into substrates previously infested with isolates of F. oxysporum f.sp. lycopersici, race 2 (10(5) conidia ml-1 of substrate). Evaluations were performed 35 days after transplanting, for severity in scale with 1=healthy plant to 6=dead plant or plant showing vessel browning and wilted leaves up to the leader shoot and seedling height. The non-pathogenic F. oxysporum isolates were efficient in reducing the severity of the disease and maintaining normal plant development. These results provide evidence of the antagonistic activity of non-pathogenic F. oxysporum isolates in controlling vascular wilt caused by F. oxysporum f. sp. lycopersici race 2 in tomato.

Ancillary services market and potential profit for generators in Russia

Reformation of electricity markets has initiated creation of ancillary services markets all over the world. The Russian electricity market reform is in transition period, that is why the problem of ancillary services market has just arisen. Since the model of market rules was created, ancillary services market became a topical question for generating companies. This master’s thesis is focused on the describing the possible ancillary services around the world and in Russia specifically. Moreover, the physical interpretation of ancillary services is defined. In addition, possibility of generation company to participate in the ancillary services market was considered. Calculations were made for primary frequency regulation service, where necessary level of price bids and payback period were evaluated.

Regional potential for collaborative implementation of small CHP plants in bioenergy technology

This thesis is a preliminary study targeting South-Eastern Finland. The objective was to find out the financial and functional readiness and willingness of the small and medium-sized enterprises of the region to manufacture and sell distributed bioenergy solutions collaboratively as a business network. In this case these solutions mean small-scale (0.5 - 3 MW) woodchips-operated combined heat and power (CHP) plants. South-Eastern Finland has suffered from a decline in the recent years, mostly due to the problems of the traditionally strong industrial know-how area of the region, the paper industry. Local small and medium-sized companies will have to find new ways to survive the toughening competition. A group of 40 companies from suitable industries were selected and financial and comparative analysis was performed on them. Additionally 19 managing directors of the companies were selected for an interview to find out their views on networking, its requirements, advantages and the general interest in it. The studied companies were found to be generally in fairly good financial condition and in that sense, fit for networking activities. The interviews revealed that the companies were capable of producing all the needed elements for the plants in question, and the managers appeared to be very interested in and have a positive attitude towards such business networks. Thus it can be said that the small and medium-sized companies of the region are capable of and interested in manufacturing small bio-CHP plants as a production network.

Supply chain cost saving potential analysis

Target of this study was to examine the current supply chain with focus on external part and identify the cost potential areas which lie there. The goal was to evaluate the cost save potential and give estimate what would be required in order to realise it. Base data related to study was searched and examined with using company’s enterprise resource planning system. In case feasible two types of scenarios were built in order to describe the scale of save potential. First scenario was theoretical and achieving it would require further investments and second scenario was realistic approach where more limitations were taken into account. The results clearly show that there is high save potential in supply chain costs linked to balance between internal and external operations. Realising of it would require at least minor investments as current internal capacity is not on a level to fully absorb the additional volumes which are needed in order to realise the potential. This study can be used as a basis when starting new projects related to investment needs.

Allelopathic potential and systematic evaluation of secondary compounds in extracts from roots of Canavalia ensiformis by capillary electrophoresis

Organic extracts were obtained from roots of Canavalia ensiformis and evaluated for allelopathic potential on the germination of the weed seeds: Mimosa pudica, Cassia tora and Cassia occidentalis showing a strong allelopathic potential. After that, a systematic study of these crude extracts was made using specific protocols developed in capillary electrophoresis (CE) in order to determine some classes of secondary metabolites. Capillary electrophoresis protocols were highly specific, which makes it possible to identify 5 classes of compounds using the same crude extract samples and analyze them fartly. Some of the compounds identified show activity in the inhibition of seeds germination.

Bound state solutions of schrödinger equation for a more general exponential screened coulomb potential via Nikiforov-Uvarov method

The arbitrary angular momentum solutions of the Schrödinger equation for a diatomic molecule with the general exponential screened coulomb potential of the form V(r) = (- a / r){1+ (1+ b )e-2b } has been presented. The energy eigenvalues and the corresponding eigenfunctions are calculated analytically by the use of Nikiforov-Uvarov (NU) method which is related to the solutions in terms of Jacobi polynomials. The bounded state eigenvalues are calculated numerically for the 1s state of N2 CO and NO

On convergence of transforms based on parabolic scaling

This thesis studies properties of transforms based on parabolic scaling, like Curvelet-, Contourlet-, Shearlet- and Hart-Smith-transform. Essentially, two di erent questions are considered: How these transforms can characterize H older regularity and how non-linear approximation of a piecewise smooth function converges. In study of Hölder regularities, several theorems that relate regularity of a function f : R2 → R to decay properties of its transform are presented. Of particular interest is the case where a function has lower regularity along some line segment than elsewhere. Theorems that give estimates for direction and location of this line, and regularity of the function are presented. Numerical demonstrations suggest also that similar theorems would hold for more general shape of segment of low regularity. Theorems related to uniform and pointwise Hölder regularity are presented as well. Although none of the theorems presented give full characterization of regularity, the su cient and necessary conditions are very similar. Another theme of the thesis is the study of convergence of non-linear M ─term approximation of functions that have discontinuous on some curves and otherwise are smooth. With particular smoothness assumptions, it is well known that squared L2 approximation error is O(M-2(logM)3) for curvelet, shearlet or contourlet bases. Here it is shown that assuming higher smoothness properties, the log-factor can be removed, even if the function still is discontinuous.

On the potential utilisation of sawdust and wood chip screenings

This work is based on the utilisation of sawdust and wood chip screenings for different purposes. A substantial amount of these byproducts are readily available in the Finnish forest industry. A black liquor impregnation study showed that sawdust-like wood material behaves differently from normal chips. Furthermore, the fractionation and removal of the smallest size fractions did not have a significant effect on the impregnation of sawdust-like wood material. Sawdust kraft cooking equipped with an impregnation stage increases the cooking yield and decreases the lignin content of the produced pulp. Impregnation also increases viscosity of the pulp and decreases chlorine dioxide consumption in bleaching. In addition, impregnation increases certain pulp properties after refining. Hydrotropic extraction showed that more lignin can be extracted from hardwood than softwood. However, the particle size had a major influence on the lignin extraction. It was possible to extract more lignin from spruce sawdust than spruce chips. Wood chip screenings are usually combusted to generate energy. They can also be used in the production of kraft pulp, ethanol and chemicals. It is not economical to produce ethanol from wood chip screenings because of the expensive wood material. Instead, they should be used for production of steam and energy, kraft pulp and higher value added chemicals. Bleached sawdust kraft pulp can be used to replace softwood kraft pulp in mechanical pulp based papers because it can improve certain physical properties. It is economically more feasible to use bleached sawdust kraft pulp in stead of softwood kraft pulp, especially when the reinforcement power requirement is moderate.

Boundary identification in the domain of a parabolic partial differential equation

Bakgrunden och inspirationen till föreliggande studie är tidigare forskning i tillämpningar på randidentifiering i metallindustrin. Effektiv randidentifiering möjliggör mindre säkerhetsmarginaler och längre serviceintervall för apparaturen i industriella högtemperaturprocesser, utan ökad risk för materielhaverier. I idealfallet vore en metod för randidentifiering baserad på uppföljning av någon indirekt variabel som kan mätas rutinmässigt eller till en ringa kostnad. En dylik variabel för smältugnar är temperaturen i olika positioner i väggen. Denna kan utnyttjas som insignal till en randidentifieringsmetod för att övervaka ugnens väggtjocklek. Vi ger en bakgrund och motivering till valet av den geometriskt endimensionella dynamiska modellen för randidentifiering, som diskuteras i arbetets senare del, framom en flerdimensionell geometrisk beskrivning. I de aktuella industriella tillämpningarna är dynamiken samt fördelarna med en enkel modellstruktur viktigare än exakt geometrisk beskrivning. Lösningsmetoder för den s.k. sidledes värmeledningsekvationen har många saker gemensamt med randidentifiering. Därför studerar vi egenskaper hos lösningarna till denna ekvation, inverkan av mätfel och något som brukar kallas förorening av mätbrus, regularisering och allmännare följder av icke-välställdheten hos sidledes värmeledningsekvationen. Vi studerar en uppsättning av tre olika metoder för randidentifiering, av vilka de två första är utvecklade från en strikt matematisk och den tredje från en mera tillämpad utgångspunkt. Metoderna har olika egenskaper med specifika fördelar och nackdelar. De rent matematiskt baserade metoderna karakteriseras av god noggrannhet och låg numerisk kostnad, dock till priset av låg flexibilitet i formuleringen av den modellbeskrivande partiella differentialekvationen. Den tredje, mera tillämpade, metoden kännetecknas av en sämre noggrannhet förorsakad av en högre grad av icke-välställdhet hos den mera flexibla modellen. För denna gjordes även en ansats till feluppskattning, som senare kunde observeras överensstämma med praktiska beräkningar med metoden. Studien kan anses vara en god startpunkt och matematisk bas för utveckling av industriella tillämpningar av randidentifiering, speciellt mot hantering av olinjära och diskontinuerliga materialegenskaper och plötsliga förändringar orsakade av “nedfallande” väggmaterial. Med de behandlade metoderna förefaller det möjligt att uppnå en robust, snabb och tillräckligt noggrann metod av begränsad komplexitet för randidentifiering.