Evaluation of the effect of the seed extract of Moringa oleifera Lam over the efficiency of organic filters in wastewater treatment of dairy cattle breeding

This study aimed to evaluate the effect of Moringa oleifera Lam extract on the removal of total solids (TS), total suspended solids (TSS) and chemical oxygen demand (COD), in different filter media for treating wastewater of dairy cattle breeding (DCW). The moringa seed extract was obtained by grinding 50 g of seeds in one liter of distilled water and, after passing the solution through a quantitative paper filter of 25 microns, 60 mL of the extract were added to wastewater from cattle breeding before the filtration process in organic filters made of thin coal, bamboo leaves, eucalyptus leaves, gliricidia branches and sawdust. This was followed by the completely randomized experimental design, adopting a factorial of 5 x 2. Aliquots of filtered effluent were collected and the total solids (TS) concentrations, total suspended solids (TSS) and chemical oxygen demand (COD) were determined. It was found that the increase in the efficiency of removal of COD and total solids can be attributed to the coagulating power of the moringa seed extract, wherein the filter medium with bamboo leaves presented the best performance, showing potential for use as alternative filter material in the primary treatment of DCW.

Performance of an anaerobic-aerobic reactor and kinetic study of organic matter removal of cattle slaughterhouse effluent

This paper sought to evaluate the behavior of an upflow Anaerobic-Aerobic Fixed Bed Reactor (AAFBR) in the treatment of cattle slaughterhouse effluent and determine apparent kinetic constants of the organic matter removal. The AAFBR was operated with no recirculation (Phase I) and with 50% of effluent recirculation (Phase II), with θ of 11h and 8h. In terms of pH, bicarbonate alkalinity and volatile acids, the results indicated the reactor ability to maintain favorable conditions for the biological processes involved in the organic matter removal in both operational phases. The average removal efficiencies of organic matter along the reactor height, expressed in terms of raw COD, were 49% and 68% in Phase I and 54% and 86% in Phase II for θ of 11h and 8h, respectively. The results of the filtered COD indicated removal efficiency of 52% and k = 0.0857h-1 to θ of 11h and 42% and k = 0.0880h-1 to θ of 8h in the Phase I. In Phase II, the removal efficiencies were 59% and 51% to θ of 11h and 8h, with k = 0.1238h-1 and k = 0.1075 h-1, respectively. The first order kinetic model showed good adjustment and described adequately the kinetics of organic matter removal for θ of 11h, with r² equal to 0.9734 and 0.9591 to the Phases I and II, respectively.

Printed low-voltage organic transistors on plastics and paper

The main advantage of organic electronics over the more widespread inorganic counterparts lies not in the electrical performance, but rather in the solution processability that opens up for low-cost flexible electronics (e.g. displays, sensors and smart tags) fabricated by using printing techniques. Replacing the commonly used laboratory-scale fabrication techniques with mass-printing techniques is, however, truly challenging, especially when low-voltage operation is required. In this thesis it is, nevertheless, demonstrated that low-voltage organic transistors can be fully printed with a similar performance to that of transistors made by laboratory scale techniques. The use of an ion-modulated type of organic field effect transistor (OFET) not only enabled low-voltage operation and printability, but was also found to result in low sensitivity to the surface roughness of the substrate. This allows not only the use of low-cost plastic substrates, but even the use of paper as a substrate. However, while absorption into the porous paper surface is advantageous in a graphical printing process, by reducing the spreading and the coffee-stain effect and by improving the adhesion, it provides great challenges when applying thin electrically active layers. In spite of these difficulties we were able to demonstrate the first low-voltage OFET to be fabricated on paper. We have also shown that low-cost incandescent lamps can be used for sintering printed metal-nanoparticles, and that the process was especially suitable on paper and compatible with a roll-to-roll manufacturing process.

Photoexcitation dynamics in organic solar cell donor/acceptor systems

Solceller presenteras ofta som ett miljövänligt alternativ för energiproduktion. Det största hindret för en bredare ibruktagning av kiselbaserade solceller är deras höga pris. I och med upptäckten av ledande och halvledande organiska (kolbaserade) molekyler och polymerer har ett nytt forskningsområde, organisk elektronik, vuxit fram. Den stora fördelen med organisk elektronik är att de använda materialen oftast är lösliga. Tillverkning av elektroniska komponenter kan då göras med hjälp av konventionella trycktekniker där bläcket ersatts med upplösta organiska material. Detta har potential att betydligt sänka priset för solceller. Nackdelen med organisk elektronik är att de använda materialen är komplexa, och de fysikaliska processerna i dem likaså. I min avhandling har jag studerat fotofysiken i två polymerer, P3HT och APFO3, som kan användas för att tillverka organiska solceller. Blandade med fullerenderivatet PCBM, som är en stark elektronacceptor, fås ett material som effektivt producerar elektroner och hål under belysning. I praktiken bidrar dock inte alla skapade laddningar till strömmen ur solcellen. Elektronerna och hålen kan förbli bundna till varandra i olika exciterade tillstånd, och även de som är fria kan träffa på motsatta laddningar under vägen till kontakterna och rekombinera. Centralt i mitt arbete har varit att identifiera olika typer av exciterade tillstånd i dessa solcellsmaterial, samt att bestämma deras livstider och rekombination. Metoden för detta har varit s.k. fotoinducerad absorption, som mäter fotoexcitationernas absorptioner i infraröda våglängdsområdet. De två viktigaste resultaten som presenteras i avhandlingen är en ratekvationsmodell för fotoexcitationsdynamiken i APFO3 på ultrasnabba tidsskalor (femtosekund - microsekund) och bildandet av en rekombinationshämmande dipol vid gränsytan för P3HT och PCBM som följd av värmebehandling. Dessa resultat bidrar till förståelsen av de fotofysikaliska processerna i relaterade material.

Studies on chemoenzymatic synthesis: Lipase-catalyzed acylation in multistep organic synthesis

In this thesis, biocatalysis is defined as the science of using enzymes as catalysts in organic synthesis. Environmental aspects and the continuously expanding repertoire of available enzymes have firmly established biocatalysis as a prominent means of chemo-, regio- and stereoselective synthesis. Yet, no single methodology can solve all the challenges faced by a synthetic chemist. Therefore, the knowledge and the skills to combine different synthetic methods are relevant. Lipases are highly useful enzymes in organic synthesis. In this thesis, an effort is being made to form a coherent picture of when and how can lipases be incorporated into nonenzymatic synthesis. This is attempted both in the literature review and in the discussion of the results presented in the original publications contained in the thesis. In addition to lipases, oxynitrilases were also used in the work. The experimental part of the thesis comprises of the results reported in four peer-reviewed publications and one manuscript. Selected amines, amino acids and sugar-derived cyanohydrins or their acylated derivatives were each prepared in enantio- or diastereomerically enriched form. Where applicable, attempts were made to combine the enzymatic reactions to other synthetic steps either by the application of completely separate sequential reactions with isolated intermediates (kinetic and functional kinetic resolution of amines), simultaneously occurring reactions without intermediate isolation (dynamic kinetic resolution of amino acid esters) or sequential reactions but without isolating the intermediates (hydrocyanation of sugar aldehydes with subsequent diastereoresolution). In all cases, lipase-catalyzed acylation was the key step by which stereoselectivity was achieved. Lipase from Burkholderia cepacia was a highly selective enzyme with each substrate category, but careful selection of the acyl donor and the solvent was important as well.