Radio frequency plasma enhanced synthesis of antifouling polymeric coatings from monoterpene alcohols

Radio frequency plasma enhanced chemical vapor deposition is currently used to fabricate a broad range of functional coatings. This work described fabrication and characterization of a novel bioactive coating, polyterpenol, for encapsulation of three-dimensional indwelling medical devices. The materials are synthesized from monoterpene alcohols under different input power conditions. The chemical composition and structure of the polyterpenol thin films were determined by Xray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR) spectroscopy, contact angle measurements, and atomic force microscopy (AFM). The application of polyterpenol coating to the substrate reduced surface roughness from 1.5 to 0.4 of a nanometer, and increased the water contact angle from to 9 to 72 degrees. The extent of attachment and extracellular polysaccharide (EPS) production of two medically relevant pathogens, Staphylococcus aureus and Staphylococcus epidermis were analyzed using scanning electron microscopy (SEM) and confocal scanning laser microscopy (CSLM). Application of polyterpenol coating fabricated at 10 W significantly inhibited attachment and growth of both pathogens compared to unmodified substrates, whilst addition of 50 W films resulted in an increased attachment, proliferation and EPS production by both types of bacteria when compared to unmodified surface. Marked dissimilarity in bacterial response between two coatings was attributed to changes in surface chemistry, nano-architecture and surface energy of polymer thin films deposited under different input power conditions.

On the number of two-line and three-line latin rectangles - an alternative approach

The number of two-line and three-line Latin rectangles is obtained by recursive methods in a setting slightly more general than usually considered. We show how this leads to a generalisation which is proved elsewhere.

Binding of three molecules in the excited state

t is shown that three neutral molecules can form a stable trimer if one of them is in the excited state. The formation of termolecular electron donor-acceptor complexes of sequence DDA and DAA arises from charge-resonance interaction.

Three-dimensional corner reflector of arbitrary apex angle

A method of analysing a 3-dimensional corner reflector antenna of arbitrary apex angle is given. Expressions have been obtained for the far field of the 3-dimensional corner reflector fed by a dipole. The radiation resistance and the directive gain of the antenna have been calculated. The method described is applicable even when the feed dipole is arbitrarily oriented. It is found that the radiation along a prescribed direction can be circularly polarised (right or left) by suitably orienting the feed dipole.

Studio portrait of Alice Burlin nee Molling, Hans Victor and Kaethe Molling with the three Pfluegner sisters.

The Pfluegner sisters were all at some time employed by the Gustav Molling family.

Walter, Ursula and Freddy, three of Fritz Gottschalk's chidren on the beach; Norderney, Germany.

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Allocasuarina tree hosts determine the spatial distribution of hypogeous fungal sporocarps in three tropical Australian sclerophyll forests

Across three tropical Australian sclerophyll forest types, site-specific environmental variables could explain the distribution of both quantity (abundance and biomass) and richness (genus and species) of hypogeous fungi sporocarps. Quantity was significantly higher in the Allocasuarina forest sites that had high soil nitrogen but low phosphorous. Three genera of hypogeous fungi were found exclusively in Allocasuarina forest sites including Gummiglobus, Labyrinthomyces and Octaviania, as were some species of Castoreum, Chondrogaster, Endogone, Hysterangium and Russula. However, the forest types did not all group according to site-scale variables and subsequently the taxonomic assemblages were not significantly different between the three forest types. At site scale, significant negative relationships were found between phosphorous concentration and the quantity of hypogeous fungi sporocarps. Using a multivariate information theoretic approach, there were other more plausible models to explain the patterns of sporocarp richness. Both the mean number of fungal genera and species increased with the number of Allocasuarina stems, at the same time decreasing with the number of Eucalyptus stems. The optimal conditions for promoting hypogeous fungi sporocarp quantity and sporocarp richness appear to be related to the presence and abundance of Allocasuarina (Casuarinaceae) host trees. Allocasuarina tree species may have a higher host receptivity for ectomycorrhizal hypogeous fungi species that provide an important food resource for Australian mycophagous animals.

Young Herbert Strauss (far right) with three unidentified friends walking down a street on an excursion to Sulzfeld, Baden.

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Effect of Packaging Materials and Storage on Major Volatile Compounds in Three Australian Native Herbs

Lemon myrtle, anise myrtle, and Tasmanian pepper leaf are commercial Australian native herbs with a high volatile or essential oil content. Packaging of the herbs in high- or low-density polyethylene (HDPE and LDPE) has proven to be ineffective in preventing a significant loss of volatile components on storage. This study investigates and compares the effectiveness of alternate high-barrier property packaging materials, namely, polyvinylidene chloride coated polyethylene terephthalate/casted polypropylene (PVDC coated PET/CPP) and polyethylene terephthalate/polyethylene terephthalate/aluminum foil/linear low-density polyethylene (PET/PET/Foil/LLDPE), in prevention of volatile compound loss from the three native herbs stored at ambient temperature for 6 months. Concentrations of major volatiles were monitored using gas chromatography?mass spectrometry (GC-MS) techniques. After 6 months of storage, the greatest loss of volatiles from lemon myrtle was observed in traditional LDPE packaging (87% loss) followed by storage in PVDC coated PET/CPP (58% loss) and PET/PET/Foil/LLDPE (loss of 23%). The volatile loss from anise myrtle and Tasmanian pepper leaf stored in PVDC coated PET/CPP and PET/PET/Foil/LLDPE packaging was <30%. This study clearly indicates the importance of selecting the correct packaging material to retain the quality of herbs with high volatile content.

The Significance of Wild Plants in the Evolutionary Ecology of Three Major Viruses Infecting Cultivated Sweetpotato in Uganda

The studies presented in this thesis contribute to the understanding of evolutionary ecology of three major viruses threatening cultivated sweetpotato (Ipomoea batatas Lam) in East Africa: Sweet potato feathery mottle virus (SPFMV; genus Potyvirus; Potyviridae), Sweet potato chlorotic stunt virus (SPCSV; genus Crinivirus; Closteroviridae) and Sweet potato mild mottle virus (SPMMV; genus Ipomovirus; Potyviridae). The viruses were serologically detected and the positive results confirmed by RT-PCR and sequencing. SPFMV was detected in 24 wild plant species of family Convolvulacea (genera Ipomoea, Lepistemon and Hewittia), of which 19 species were new natural hosts for SPFMV. SPMMV and SPCSV were detected in wild plants belonging to 21 and 12 species (genera Ipomoea, Lepistemon and Hewittia), respectively, all of which were previously unknown to be natural hosts of these viruses. SPFMV was the most abundant virus being detected in 17% of the plants, while SPMMV and SPCSV were detected in 9.8% and 5.4% of the assessed plants, respectively. Wild plants in Uganda were infected with the East African (EA), common (C), and the ordinary (O) strains, or co-infected with the EA and the C strain of SPFMV. The viruses and virus-like diseases were more frequent in the eastern agro-ecological zone than the western and central zones, which contrasted with known incidences of these viruses in sweetpotato crops, except for northern zone where incidences were lowest in wild plants as in sweetpotato. The NIb/CP junction in SPMMV was determined experimentally which facilitated CP-based phylogenetic and evolutionary analyses of SPMMV. Isolates of all the three viruses from wild plants were genetically similar to those found in cultivated sweetpotatoes in East Africa. There was no evidence of host-driven population genetic structures suggesting frequent transmission of these viruses between their wild and cultivated hosts. The p22 RNA silencing suppressor-encoding sequence was absent in a few SPCSV isolates, but regardless of this, SPCSV isolates incited sweet potato virus disease (SPVD) in sweetpotato plants co-infected with SPFMV, indicating that p22 is redundant for synergism between SCSV and SPFMV. Molecular evolutionary analysis revealed that isolates of strain EA of SPFMV that is largely restricted geographically in East Africa experience frequent recombination in comparison to isolates of strain C that is globally distributed. Moreover, non-homologous recombination events between strains EA and C were rare, despite frequent co-infections of these strains in wild plants, suggesting purifying selection against non-homologous recombinants between these strains or that such recombinants are mostly not infectious. Recombination was detected also in the 5 - and 3 -proximal regions of the SPMMV genome providing the first evidence of recombination in genus Ipomovirus, but no recombination events were detected in the characterized genomic regions of SPCSV. Strong purifying selection was implicated on evolution of majority of amino acids of the proteins encoded by the analyzed genomic regions of SPFMV, SPMMV and SPCSV. However, positive selection was predicted on 17 amino acids distributed over the whole the coat protein (CP) in the globally distributed strain C, as compared to only 4 amino acids in the multifunctional CP N-terminus (CP-NT) of strain EA largely restricted geographically to East Africa. A few amino acid sites in the N-terminus of SPMMV P1, the p7 protein and RNA silencing suppressor proteins p22 and RNase3 of SPCSV were also submitted to positive selection. Positively selected amino acids may constitute ligand-binding domains that determine interactions with plant host and/or insect vector factors. The P1 proteinase of SPMMV (genus Ipomovirus) seems to respond to needs of adaptation, which was not observed with the helper component proteinase (HC-Pro) of SPMMV, although the HC-Pro is responsible for many important molecular interactions in genus Potyvirus. Because the centre of origin of cultivated sweetpotato is in the Americas from where the crop was dispersed to other continents in recent history (except for the Australasia and South Pacific region), it would be expected that identical viruses and their strains occur worldwide, presuming virus dispersal with the host. Apparently, this seems not to be the case with SPMMV, the strain EA of SPFMV and the strain EA of SPCSV that are largely geographically confined in East Africa where they are predominant and occur both in natural and agro-ecosystems. The geographical distribution of plant viruses is constrained more by virus-vector relations than by virus-host interactions, which in accordance of the wide range of natural host species and the geographical confinement to East Africa suggest that these viruses existed in East African wild plants before the introduction of sweetpotato. Subsequently, these studies provide compelling evidence that East Africa constitutes a cradle of SPFMV strain EA, SPCSV strain EA, and SPMMV. Therefore, sweet potato virus disease (SPVD) in East Africa may be one of the examples of damaging virus diseases resulting from exchange of viruses between introduced crops and indigenous wild plant species. Keywords: Convolvulaceae, East Africa, epidemiology, evolution, genetic variability, Ipomoea, recombination, SPCSV, SPFMV, SPMMV, selection pressure, sweetpotato, wild plant species Author s Address: Arthur K. Tugume, Department of Agricultural Sciences, Faculty of Agriculture and Forestry, University of Helsinki, Latokartanonkaari 7, P.O Box 27, FIN-00014, Helsinki, Finland. Email: tugume.arthur@helsinki.fi Author s Present Address: Arthur K. Tugume, Department of Botany, Faculty of Science, Makerere University, P.O. Box 7062, Kampala, Uganda. Email: aktugume@botany.mak.ac.ug, tugumeka@yahoo.com

Physical characterization of plastic surfaces in wearing and cleanability research

Plastic surfaces are a group of materials used for many purposes. The present study was focused on methods for investigation of surface topography, wearing and cleanability of polyvinyl chloride (PVC) model surfaces and industrial plastic surfaces. Contact profilometry, scanning electron microscopy (SEM) and atomic force microscopy (AFM) are powerful methods for studying the topography of plastic surfaces. Although they have their own limitations, they are together an effective tool providing useful information on surface topography, especially when studying laboratory-made PVC model surfaces with known chemical compositions and structures. All examined laboratory-made PVC plastic surfaces examined in this work could be considered as smooth according to both AFM and profilometer measurements because height differences are in the nanoscale on every surface. Industrial plastic surfaces are a complex group of materials because of their chemical and topographical heterogeneity, but they are nevertheless important reference materials when developing cleaning and wearing methods. According to the results of this study the Soiling and Wearing Drum and the Frick-Taber methods are very useful when simulating three-body wearing of plastic surfaces. Both the investigated wearing methods can be used to compare the wearing of different plastic materials using appropriate evaluation methods of wearing and industrial use. In this study, physical methods were developed and adapted from other fields of material research to cleanability studies. The thesis focuses on the methodology for investigating the cleanability of plastic surfaces under realistic conditions, where surface topography and the effect of wear cleanability were among the major topics. A colorimetric method proved to be suitable for examining the cleanability of the industrial plastic surfaces. The results were utilized to evaluate the relationship between cleanability and the surface properties of plastic surfaces. The devices and methods used in the work can be utilized both in material research and product development.

Role of heat treatment in the processing and quality of oat flakes

This thesis reports on investigations into the influence of heat treatment on the manufacturing of oat flakes. Sources of variation in the oat flake quality are reviewed, including the whole chain from the farm to the consumer. The most important quality parameters of oat flakes are the absence of lipid hydrolysing enzymes, specific weight, thickness, breakage (fines), water absorption. Flavour, colour and pasting properties are also important, but were not included in the experimental part of this study. Of particular interest was the role of heat processing. The first possible heat treatment may occur already during grain drying, which in Finland generally happens at the farm. At the mill, oats are often kilned to stabilise the product by inactivating lipid hydrolysing enzymes. Almost invariably steaming is used during flaking, to soften the groats and reduce flake breakage. This thesis presents the use of a material science approach to investigating a complex system, typical of food processes. A combination of fundamental and empirical rheological measurements was used together with a laboratory scale process to simulate industrial processing. The results were verified by means of industrial trials. Industrially produced flakes at three thickness levels (nominally 0.75, 0.85 and 0.90 mm) were produced from kilned and unkilned oat groats, and the flake strength was measured at different moisture contents. Kilning was not found to significantly affect the force required to puncture a flake with a 2mm cylindrical probe, which was taken as a measure of flake strength. To further investigate how heat processing contributes to flake quality, dynamic mechanical analysis was used to characterise the effect of heat on the mechanical properties of oats. A marked stiffening of the groat, of up to about 50% increase in storage modulus, was observed during first heating at around 36 to 57°C. This was also observed in tablets prepared from ground groats and extracted oat starch. This stiffening was thus attributed to increased adhesion between starch granules. Groats were steamed in a laboratory steamer and were tempered in an oven at 80 110°C for 30 90 min. The maximum force required to compress the steamed groats to 50% strain increased from 50.7 N to 57.5 N as the tempering temperature was increased from 80 to 110°C. Tempering conditions also affected water absorption. A significantly higher moisture content was observed for kilned (18.9%) compared to unkilned (17.1%) groats, but otherwise had no effect on groat height, maximum force or final force after a 5 s relaxation time. Flakes were produced from the tempered groats using a laboratory flaking machine, using a roll gap of 0.4 mm. Apart from specific weight, flake properties were not influenced by kilning. Tempering conditions however had significant effects on the specific weight, thickness and water absorption of the flakes, as well as on the amount of fine material (<2 mm) produced during flaking. Flake strength correlated significantly with groat strength and flake thickness. Trial flaking at a commercial mill confirmed that groat temperature after tempering influenced water absorption. Variation in flake strength was observed , but at the groat temperatures required to inactivate lipase, it was rather small. Cold flaking of groats resulted in soft, floury flakes. The results presented in this thesis suggest that heating increased the adhesion between starch granules. This resulted in an increase in the stiffness and brittleness of the groat. Brittle fracture, rather than plastic flow, during flaking could result in flaws and cracks in the flake. These would be expected to increase water absorption. This was indeed observed as tempering temperature increased. Industrial trials, conducted with different groat temperatures, confirmed the main findings of the laboratory experiments. The approach used in the present study allowed the systematic study of the effect of interacting process parameters on product quality. There have been few scientific studies of oat processing, and these results can be used to understand the complex effects of process variables on flake quality. They also offer an insight into what happens as the oat groat is deformed into a flake.

Pathogenicity studies in avocado with three nectriaceous fungi, Calonectria ilicicola, Gliocladiopsis sp and Ilyonectria liriodendri

Calonectria ilicicola, Gliocladiopsis sp. and Ilyonectria liriodendri were isolated from diseased roots of young avocado trees. Pathogenicity studies with seedlings of three avocado cultivars, Velvick, Hass and Reed, demonstrated that Calonectria ilicicola is a severe root rot pathogen, reducing the biomass of healthy roots, and reducing plant height over time. Calonectria ilicicola was re-isolated from diseased roots. Ilyonectria liriodendri and Gliocladiopsis sp. were not pathogenic and plant height was increased after Gliocladiopsis sp. amendment compared to all other treatments in trials with cvs Velvick and Hass.

The law and policy for electricity generated by renewable energy: Greening the power in three Middle Eastern jurisdictions

This thesis examines the law and policy concerning renewable energy electricity generation in Palestine, Jordan, and Abu Dhabi. The thesis gives greater attention to the promotion of solar power owing to the abundance and viability. It appears that energy security profoundly underpins the utilisation of renewable electricity, and the motivation of climate change mitigation also pays a role in the promotion of renewable energy in these jurisdictions. However, current policies and regulations are not fully able to promote the renewables in the power sector. The thesis submits that reforms of law and policy are necessary to enhance the achievement of environmental and energy goals.

Portrait of three unidentified men outdoors (Prof. and Dr.) Portraits Groups Men

Handwritten names (illegible) on verso