Синтез мультитопных лигандов -производных имидазола и триазола с использованием фениленового линкера

Aufgrund veränderter Marktbedingungen sind produzierende Unternehmen zunehmend gezwungen, sich mit immer komplexeren Produkten und steigender Variantenvielfalt in kürzeren Zeitabschnitten auf wettbewerbsintensiven Märkten zu behaupten. Als Konsequenz ist es erforderlich, die Produktentwicklung effektiver und effizienter zu gestalten. Demzufolge müssen auch die mit Werkstoff- und Verfahrensinnovationen verbundenen Rationalisierungspotentialen gezielt genutzt werden. Dies ist jedoch nur möglich, wenn werkstoff- und verfahrensspezifische Restriktionen bereits in einer frühen Produktentwicklungsphase Berücksichtigung finden. Um hierfür geeignete Voraussetzungen zu schaffen, wurden EDV-Hilfsmittel entwickelt. Die Prototypen Innotech, Ratech und Techbase unterstützen die integrierte Technologieplanung und ermöglichen bereits in frühen Phasen der Produktentwicklung eine optimale Abstimmung der Faktoren Gestalt, Werkstoff und Technologie

Mediator combined gaseous substrate for electricity generation in microbial fuel cells (MFCs) and potential integration of a MFC into an anaerobic biofiltration system.

Microbial fuel cells (MFCs) are emerging energy production technology which converts the chemical energy stored in biologically degradable compounds to electricity at high efficiencies. Microbial fuel cells have some advantages such as use of an inexpensive catalyst, operate under mild reaction conditions (i.e. ambient temperature, normal pressure and neutral pH), and generate power from a wide range and cheap raw materials. These make microbial fuel cell as an attractive alternative over other electricity generating devices. However, so far the major problem posses by this technology is the low power outputs of the microbial fuel cells that hinder its commercialization. Restriction in the electron transfer from bacteria to the anode electrode of a MFC is thought to be one cause for the low power output. Most recent MFC research is focused on using contaminants present in industrial, agricultural, and municipal wastewater as the energy source, with very few studies utilising gaseous substrates. Mediators can be added to MFCs to enhance the electron transfer from the microbe to the anode, but have limited practical applicability in wastewater applications because of the difficulty in recovering the expensive and potentially toxic compound. This thesis describes an investigation of electricity generation in a microbial fuel cell by combining a gaseous substrate with a mediator in the anode compartment. The emphasis being placed on the selection of a mediator to improve the electron transfer process for electricity production in an MFC. Subsequently, methods to improve the performance of a mediator MFC in respect of power and current density were discussed. This type of MFC is purposely aimed to be applied for treating gaseous contaminants in an anaerobic biofilter while simultaneously produce electricity. In this study, ethanol was the first gaseous substrate tested for the possibility to generate electricity in the MFC. Various mediators were previously compared in their reversibility of redox reactions and in the current production, and three best mediators were then selected for the power production. The highest electrical current production i.e. 12 μA/cm2 was obtained and sustained for 24 hrs with N,N,N',N'-tetramethyl-1,4- phenylendiamine TMPD (N-TMPD) as the mediator using glassy carbon (GC) electrode. The maximum power density reached 0.16 mW/cm2 by using carbon cloth (CC) anode. The absorption of these mediators by the bacterial cells was shown to correlate with the obtained energy production, with no N-TMPD was absorbed by the bacterial cells. The 24 hr current production was shown to be accompanied by the decrease in the ethanol concentration (i.e. 1.82 g/L), however ethanol crossover through the proton exchange membrane and ethanol evaporation around the electrodes were most likely to be the major cause of the decrease in the ethanol concentration. A theoretical coulombic efficiency of 0.005% was calculated for this system. The electrokinetics of microbial reduced mediator in the ethanol-mediator MFCs was also examined. Two methods i.e. linear sweep voltammetry (LSV) and cyclic voltammetry (CV) were used to obtained the kinetic parameters. CV method gave a better estimation of the kinetic parameters than LSV method due to the low concentration of the mediators used, affecting the Tafel behaviors. All CVs showed quasi-reversible behaviors compared to the CVs in the absence of the bacteria, which is thought due to the bacteria decreased the amount of the reduced and the oxidised mediator available at the surface of GC electrode. The highest exchange current density (i o ) was obtained by using N-TMPD as the mediator with the same concentration of the mediator used i.e. 0.13±0.01 mA/cm 2. The power output achieved also the highest (0.008 mW/cm 2) with N-TMPD as the mediator. The power density was improved to 0.03 mW/cm2 by using CC electrode. Another main objective of this thesis is to prove anoxic methane oxidation which was believed to occur only in marine sediments, and applies this for power generation in microbial fuel cells. Ferricyanide looked promising when it was used as the electron acceptor (thus as the mediator for the MFC). It was shown that ferricyanide was fully reduced by methanotrophs bacteria with methane as the substrate (versus abiotic and nitrogen control). The highest reduction rate achieved was 3 x10-3 mM/min.g. This finding was supported by ferricyanide peak heights disappearance (spectrophotometry at 420 nm), CO 2 production (sensor readings), ferrocyanide formation (cyclic voltammetry), and no other alternate electron acceptor was present. The total CO 2 produced was equal to 0.015 mmoles of CO 2 from starting concentration ferricyanide of 0.2 mmoles (after substraction with an offset value). CV results show 2.4 mM of ferrocyanide was produced after a total addition of 3 mM ferricyanide into the anoxic methanotrophic suspension. The current and voltage generation in microbial fuel cell reactor from the reduced ferricyanide confirmed that ferricyanide received electrons from the bacterial metabolism. The maximum power density of 0.02 mW/cm2 and OCV of 0.6 V were obtained with 3 mM ferricyanide using LSV method

The synthesis of macromolecules in the left colleterial gland of Periplaneta americana during the reproductive cycle.

The synthesis of proteins and RNA in the left colleterial gland (LCG) of P. americana during the reproductive cycle are cyclic, highly dynamic processes. The patterns of protein synthesis and accumulation in the gland fluctuate very rapidly throughout the reproductive cycle. Three major peaks in levels of protein synthesis are detected during the cycle. Two of these, occurring in close succession, take place before the onset of ootheca synthesis, whereas the last peak occurs shortly before ootheca deposition and extends into the early phases of the new cycle. The patterns of translational activity and protein accumulation in the gland suggest that the LCG could be involved in the production of proteins for export as well as for ootheca synthesis. The pattern of total RNA synthesis in the LCG closely follows that of protein synthesis during the reproductive cycle. Three major peaks in total RNA synthesis are observed, each of which occurs eight hours before a peak in protein synthesis and corresponds to enhanced production of poly(A)-RNA. The major increases in poly(A)+ RNA synthesis in the LCG correlate precisely with the peaks in protein synthesis. The LCG is known to be functionally dependent upon juvenile hormone (JH). However, the transcriptional and translational responses of the gland to the presence of the hormone in vitro are not stereotyped but highly stage-specific. Short term in vitro JH III treatment primarily affects RNA synthesis in the LCG, but the transcriptional response of the gland to the presence of the hormone may be positive (RNA synthesis stimulated), negative (inhibition of RNA synthesis) or null, depending on the stage of the cycle. The stages of high transcriptional activity observed in the LCG during the reproductive cycle correlate precisely with the stages at which in vitro JH III treatment elicits a large positive response from the isolated gland. The immediate translational response of the gland to the presence of JH III in vitro is generally negative, except at the stages of high endogenous translational activity. However, it is not entirely clear whether or not JH III is solely responsible for the initial appearance of the endogenous increases in RNA and protein synthesis observed in the LCG during the reproductive cycle. It is apparent that JH III is not the only regulatory factor controlling LCG activities during the reproductive cycle. A major regulatory system controlling the secretory and possibly transcriptional activities of the LCG during the reproductive cycle has been uncovered. In vitro ecdysterone treatment, of glands isolated at stages far removed from ovulation and the onset of ootheca synthesis, depresses transcriptional activity in the LCG and induces the gland to spontaneously release its luminal content. The inhibitory effects of ecdysterone upon in vitro RNA synthesis are only slightly alleviated by JH III when both hormones are present in equal amounts while ecdysone-induced secretory activity is inhibited. The presence of ovarioles isolated at 64h (onset of in vivo LCG secretory activity) in the incubation medium gives rise to a very strong inhibition of RNA synthesis in the LCG while concurrently inducing secretory activity is inhibited

Fractal nature in fat crystal networks

The determination of the mechanical and rheological characteristics of several plastic fats requires a detailed understanding of the microstructure of the fat crystal network aggregates. The fractal approach is useful for the characterization of this microstructure. This review begins with information on fractality and statistical self-similar structure. Estimations for fractal dimension by means of equations relating the volume fraction of solid fat to shear elastic modulus G’ in linear region are described. The influence of interesterification on fractal dimension decrease (from 2,46 to 2,15) for butterfat-canola oil blends is notable. This influence is not significant for fat blends without butterfat. The need for an increase in research concerning the relationship between fractality and rheology in plastic fats is emphasized.La determinación de las características mecánicas y reológicas de ciertas grasas plásticas requiere conocimientos detallados sobre las microestructuras de los agregados que forman la red de cristales grasos. El estudio de la naturaleza fractal de estas microestructuras resulta útil para su carac­terización. Este artículo de información se inicia con descripciones de la dimensión fractal y de la "autosimilitud estadística". A continuación se describe el cálculo de la dimensión fractal mediante ecuaciones que relacionan la fracción en volumen de grasa sólida con el módulo de recuperación (G') dentro de un comportamiento viscoelástico lineal. Se destaca la influencia que la interesterificación ejerce sobre la dimensión fractal de una mezcla de grasa láctea y aceite de canola (que pasa de 2,64 a 2,15). Esta influencia no se presenta en mezclas sin grasa láctea. Se insiste sobre la necesidad de incrementar las investi­gaciones sobre la relación entre reología y estructura fractal en grasas plásticas.Peer reviewe

Measurement of Spin Correlation Parameters ANN_{NN}, ASS_{SS}, and A_SL{SL} at 2.1 GeV in Proton-Proton Elastic Scattering

At the Cooler Synchrotron COSY/J\"ulich spin correlation parameters in elastic proton-proton (pp) scattering have been measured with a 2.11 GeV polarized proton beam and a polarized hydrogen atomic beam target. We report results for A$_{NN}$, A$_{SS}$, and A_${SL}$ for c.m. scattering angles between 30$^o$ and 90$^o$. Our data on A$_{SS}$ -- the first measurement of this observable above 800 MeV -- clearly disagrees with predictions of available of pp scattering phase shift solutions while A$_{NN}$ and A_${SL}$ are reproduced reasonably well. We show that in the direct reconstruction of the scattering amplitudes from the body of available pp elastic scattering data at 2.1 GeV the number of possible solutions is considerably reduced.Comment: 4 pages, 4 figure

Parity Violation in Proton-Proton Scattering at 221 MeV

The parity-violating longitudinal analyzing power, Az, has been measured in pp elastic scattering at an incident proton energy of 221 MeV. The result obtained is Az =(0.84 +/- 0.29 (stat.) +/- 0.17 (syst.)) x 10^{-7}. This experiment is unique in that it selects a single parity violating transition amplitude, 3P2-1D2, and consequently directly constrains the weak meson-nucleon coupling constant h^pp_rho When this result is taken together with the existing pp parity violation data, the weak meson-nucleon coupling constants h^pp_rho and h^pp_omega can, for the first time, both be determined.Comment: 8 pages RevTeX4, 3 PostScript figures. Conclusion revised. New information about weak coupling constants adde