Biochemical characteristics of composite flours: influence of fermentation

The purpose of this study was to introduce yam in the development of two new composite flours containing soy and cassava. Two composite flours were obtained after fermentation of yam, soybean, and cassava in respectively 60, 30, and 10% proportions. Two varieties of yam were used: Dioscorea alata (variety "Bete bete") and Dioscorea cayenensis (variety "Lokpa"). Proximate composition, mineral content, some anti-nutritional factors (oxalates, phenols), microbiological quality, and α-amylase digestibility were determined for the fermented and unfermented composite flours. The results indicated that for the composite flours made of D. alata and D. cayenensis, fermentation increased ash and titrable acidity. Carbohydrates, pH, and energy decreased. Crude fat content was not affected by the fermentation process. Anti-nutritional factors such as oxalates and phenols were found to decrease significantly after the fermentation of the composite flours. Fermentation increased the mineral content (Mg, K, Fe, and Ca) of the composite flours. A decrease in P and Na was observed after fermentation. The microbiological study showed that safety flours contain no potential pathogenic germs. The in vitro α-amylase digestibility of the composite flours was significantly improved after fermentation. The biochemical characteristics and good hygienic quality of the obtained flours suggest that these flours can be considered as a feeding alternative for children in poor areas where yam is produced.

Functionalisation of spruce O-acetyl-galactoglucomannans for barrier and composite applications

The increasing use of energy, food, and materials by the growing population in the world is leading to the situation where alternative solutions from renewable carbon resources are sought after. The growing use of plastics depends on the raw-oil production while oil refining are politically governed and required for the polymer manufacturing is not sustainable in terms of carbon footprint. The amount of packaging is also increasing. Packaging is not only utilising cardboard and paper, but also plastics. The synthetic petroleum-derived plastics and inner-coatings in food packaging can be substituted with polymeric material from the renewable resources. The trees in Finnish forests constitute a huge resource, which ought to be utilised more effectively than it is today. One underutilised component of the forests is the wood-derived hemicelluloses, although Spruce Oacetyl-galactoglucomannans (GGMs) have previously shown high potential for material applications and can be recovered in large scale. Hemicelluloses are hydrophilic in their native state, which restrains the use of them for food packaging as non-dry item. To cope with this challenge, we intended to make GGMs more hydrophobic or amphiphilic by chemical grafting and consequently with the focus of using them for barrier applications. Methods of esterification with anhydrides and cationic etherification with a trimethyl ammonium moiety were established. A method of controlled synthesis to obtain the desired properties by the means of altering temperature, reaction time, the quantity of the reagent, and even the solvent for purification of the products was developed. Numerous analytical tools, such as NMR, FTIR, SEC-MALLS/RI, MALDI-TOF-MS, RP-HPLC and polyelectrolyte titration were used to evaluate the products from different perspectives and to acquire parallel proofs of their chemical structure. Modified GGMs with different degree of substitution and the correlating level of hydrophobicity was applied as coatings on cartonboard and on nanofibrillated cellulose-GGM films to exhibit barrier functionality. The water dispersibility in processing was maintained with GGM esters with low DS. The use of chemically functionalised GGM was evaluated for the use as barriers against water, oxygen and grease for the food packaging purposes. The results show undoubtedly that GGM derivatives exhibit high potential to function as a barrier material in food packaging.

Transmission oflight through individually formed fiber- reinforced composite post (Yksilöllisesti muotoillun kuitukomposiittinastan valonläpäisevyys)

Kuitukomposiitista valmistettuja juurikanavanastoja käytetään apuna, kun restauroidaan juurihoidettuja ja kruunuosastaan runsaasti kudosta menettäneitä hampaita. Kliinisen kestävyyden kannalta on tärkeää että nasta kiinnittyy hampaaseen hyvin. Tarvittavan valomäärän saattaminen valokovetuksella pimeään juurikanavaan on vaikeaa ja sen vuoksi nastojen kiinnittämiseen suositellaan kaksoiskovetteista yhdistelmämuovisementtiä, joka kovettuu vain osittain valolla. Jotta nasta ja sementti polymeroituisivat hyvin, nastan hyvä valonläpäisy- ja sirontakyky olisi eduksi. Tehdasvalmisteisten nastojen valonläpäisykyvyn on todettu heikkenevän niiden pituuden kasvaessa. Yksilöllisesti muotoilluilla kuitukomposiittinastoilla, joilla on osittaislomittaismuoviverkostorakenne (semi-IPN) polymeerimatriisi, on todettu tehdasvalmisteisia kuitunastoja parempi sidos nastan ja yhdistelmämuovisementin välillä. Yksilöllisesti muotoilluilla kuitunastoilla näyttäisi myös olevan hyvä valonjohtamiskyky, mutta lisätutkimuksia tarvitaan. Tässä tutkimuksessa selvitettiin yksilöllisesti muotoillun kuitukomposiittinastan (EverStick Post) ja kahden tehdasvalmisteisen (Relyx Fiber Post ja GC Fiber Post) kuitukomposiittina stan valonläpäisevyyttä sekä pituuden vaikutusta niiden valonläpäisykykyyn laboratorio- olosuhteissa. Tutkimushypoteesi oli, että nastojen valonläpäisykyky heikkenee niiden pidentyessä. Tutkimuksessa kaikista nastatyypeistä valmistettiin eripituisia nastoja (4, 8, 12 ja 16 mm). Nastoille tehtiin samanpituiset testikappaleet muoviputkesta ja polyvinyylisiloksaanista, ja nastat asetettiin niiden sisään. Tämän jälkeen nastoja kovetettiin valokovettimella 10 sekuntia, ja läpi päässyt valo mitattiin MARC Resin Calibrator -laitteella. Kontrollina käytettiin tyhjää testikappaletta ilman nastaa. Keskeiseksi tulokseksi saatiin, että yksilöllisesti muotoillulla kuitukomposiittinastalla oli kaikissa pituusryhmissä muita nastoja merkitsevästi parempi valonläpäisykyky. Tulokset osoittivat myös, että kaikkien nastojen valonläpäisevyys laski merkitsevästi nastan pituuden lisääntyessä aina 12 millimetriin asti. Tulosten perusteella yksilöllisesti muotoillulla kuitukomposiittinastalla on tehdasvalmisteista nastaa parempi valonläpäisykyky. Kuitukomposiittinastojen valonläpäisykyky heikkenee niiden pituuden kasvaessa aiempien tutkimusten mukaisesti. Jatkotutkimuksissa tulisi selvittää, miten valonläpäisevyys ja siroaminen vaikuttavat nastan ja sementin polymeroitumiseen ja siten kliiniseen lopputulokseen.

A software engineering approach to distributed systems for composite modeling

The goal of this thesis is to define and validate a software engineering approach for the development of a distributed system for the modeling of composite materials, based on the analysis of various existing software development methods. We reviewed the main features of: (1) software engineering methodologies; (2) distributed system characteristics and their effect on software development; (3) composite materials modeling activities and the requirements for the software development. Using the design science as a research methodology, the distributed system for creating models of composite materials is created and evaluated. Empirical experiments which we conducted showed good convergence of modeled and real processes. During the study, we paid attention to the matter of complexity and importance of distributed system and a deep understanding of modern software engineering methods and tools.

Optimal distance of the light-curing tip for light transmission through the resin composite

Hammaslääketieteessä käytetettävien komposiittien valonläpäisevyys vaihtelee. Samoin LED-valokovettimet eroavat toisistaan valotehonsa ja muotoilunsa perusteella. On yleisesti tiedossa, että valokovettimesta tulevan valon intensiteetti pinta-alayksikköä kohden heikkenee, kun kovettimen etäisyys kasvaa. Toisaalta ei ole tiedossa, miten valokovetettavan kohteen ja valokovettimen kärjen väliin sijoitettu materiaali tarkalleenottaen vaikuttaa valon intensiteettiin eri etäisyyksiä käytettäessä. Tämän tutkimuksen tarkoituksena on selvittää, miten valokovetettavan kohteen ja valokovettimen kärjen väliin asetettava etukäteen polymerisoitu materiaali vaikuttaa valon intensiteettiin eri etäisyyksillä. Tutkimus suoritettiin käyttämällä kahta eri valokovetinta. Jotta etäisyyden vaikutusta valotustehoon voitiin demonstroida, vaihdettiin kovettimen etäisyyttä sensorista 0,2,4,6,8,10mm välillä. Valotehot rekisteröitiin MARC resin calibrator -laitteella. Sensorin ja valokovettimen kärjen väliin asetettavat erilaiset komposiittilevyt olivat valmiiksi kovetettuja,1mm paksuisia, filleripitoisuuksiltaan neljää erilaista muovia. Valotehot rekisteröitiin jokaiselta etäisyydeltä komposiitin ollessa sensorin päällä. Rinnakkaisesti verrattiin myös etäisyyden vaikutusta valotehoon ilman esikovetettua materiaalia kovettimen kärjen ja valoa mittaavan sensorin välissä. Vertailun suorittamiseksi laskettiin intensiteettisuhdeluku muovillisen ja muovittoman arvon välillä aina tietyllä etäisyydellä Valokovettimen kärjen etäisyyden kasvattaminen sensorista (eli valokovetettavasta kohteesta) odotusten mukaisesti pienensi valotehoa. Laittamalla sensorin ja kovettimen väliin komposiittilevy, valoteho pieneni odotetusti vielä enemmän. Tutkittaessa intensiteettisuhdetta (valoteho muovin kanssa : valoteho ilman muovia) kuitenkin huomattiin, että 4-6mm:n kohdalla suhdeluku oli suurempi kuin 0,2,8 ja 10mm kohdalla. Johtopäätöksenä oli, että suurin mahdollinen valokovetusteho saavutetan laittamalla kovetuskärki mahdollisimman lähelle kohdetta. Jos valokovetettavan kohteen ja valokovettimen kärjen välissä oli kiinteä komposiittipalanen, suurin mahdollinen valokovetusteho kohteeseen saavutetaan edelleen laittamalla kovetuskärki kiinni muoviin. Jos etäisyyttä muovin pinnasta sen sijaan kasvatettiin, valokovetusteho ei laskenutkaan niin nopeasti kuin oli odotettu. Tämä voi liittyä siihen, että tehokkaan valokeilan halkaisijan koko on suurempi verrattuna komposiitin sekä sensorin halkaisian kokoon. Toiseksi on arvioitu, että resiinikomposiitin täyteaineet voisivat fokusoida läpi kulkevaa valoa sensoriin. Se, pitääkö tämä ilmiö paikkansa, vaatii kuitenkin enemmän tutkimusta

Viologen based electroactive polymers and composites for durable electrochromic systems

Electrochromism, the phenomenon of reversible color change induced by a small electric charge, forms the basis for operation of several devices including mirrors, displays and smart windows. Although, the history of electrochromism dates back to the 19th century, only the last quarter of the 20th century has its considerable scientific and technological impact. The commercial applications of electrochromics (ECs) are rather limited, besides top selling EC anti-glare mirrors by Gentex Corporation and airplane windows by Boeing, which made a huge commercial success and exposed the potential of EC materials for future glass industry. It is evident from their patents that viologens (salts of 4,4ʹ-bipyridilium) were the major active EC component for most of these marketed devices, signifying the motivation of this thesis focusing on EC viologens. Among the family of electrochromes, viologens have been utilized in electrochromic devices (ECDs) for a while, due to its intensely colored radical cation formation induced by applying a small cathodic potential. Viologens can be synthesized as oligomer or in the polymeric form or as functionality to conjugated polymers. In this thesis, polyviologens (PVs) were synthesized starting from cyanopyridinium (CNP) based monomer precursors. Reductive coupling of cross-connected cyano groups yields viologen and polyviologen under successive electropolymerization using for example the cyclic voltammetry (CV) technique. For further development, a polyviologen-graphene composite system was fabricated, focusing at the stability of the PV electrochrome without sacrificing its excellent EC properties. High electrical conductivity, high surface area offered by graphene sheets together with its non-covalent interactions and synergism with PV significantly improved the electrochrome durability in the composite matrix. The work thereby continued in developing a CNP functionalized thiophene derivative and its copolymer for possible utilization of viologen in the copolymer blend. Furthermore, the viologen functionalized thiophene derivative was synthesized and electropolymerized in order to explore enhancement in the EC contrast and overall EC performance. The findings suggest that such electroactive viologen/polyviologen systems and their nanostructured composite films as well as viologen functionalized conjugated polymers, can be potentially applied as an active EC material in future ECDs aiming at durable device performances.

[Recueil composite].

Contient : S. Ambrosius, De officiis ; Fragments d'un antiphonaire

[Recueil composite].

Contient : Boetius, De institutione musica ; De divinis officiis, libri I-III ; Homeliae [fragments] ; Robertus de Sancto Remigio, Historia Hierosolimitana ; Homeliae super evangelia

Production under glass : working conditions and class-consciousness of the Niagara greenhouse workers

This study applies a Marxist theoretical paradigm to examine the working conditions of greenhouse workers in the Niagara Region, and the range of factors that bear upon the formation of their class-consciousness. The Niagara greenhouse industry represents one of the most developed horticultural regions in Canada and plays a prominent role in the local economy. The industry generates substantial revenues and employs a significant number of people, yet the greenhouse workers are paid one of the lowest rates in the region. Being classified as agricultural workers, the greenhouse employees are exempted from many provisions of federal and provincial labour regulations. Under the current provincial statutes, agricultural workers in Ontario are denied the right to organize and bargain collectively. Except for a few technical and managerial positions, the greenhouse industry employs mostly low-skilled workers who are subjected to poor working conditions that stem from the employer's attempts to adapt to larger structural imperatives of the capitalist economy. While subjected to these poor working conditions, the greenhouse workers are also affected by objectively alienated social relations and by ruling class ideological domination and hegemony. These two sets of factors arise from the inherent conflict of interests between wage-labour and capital but also militate against the development of class-consciousness. Semi-structured interviews were conducted with 12 greenhouse workers to examine the role played by their material circumstances in the formulation of their social and political views as well as the extent to which they are aware of their class location and class interests. The hegemonic notions of 'common sense' acted as impediments to formation of classconsciousness. The greenhouse workers have virtually no opportunities to access alternative perspectives that would address the issues associated with exploitation in production and offer solutions leading to 'social justice'. Fonnidable challenges confront any organized political body seeking to improve the conditions of the working people.

Investigations into phosphorus removal by constructed wetlands : root bed media modifications /

A study has been conducted focusing on how the phosphorus renrx)val efficiency of a constructed wetland (CW) can be optimized through the selective enrichment of the substratum. Activated alumina and powdered iron were examined as possible enrichment compounds. Using packed glass column trials it was found that alumina was not suitable for the renx)val of ortho-phosphate from solution, while mixtures of powdered iron and quartz sand proved to be very efficient. The evaluation of iron/sand mixtures in CWs planted with cattails was performed in three stages; first using an indoor lab scale wetland, then an outdoor lab scale wetland, and finally in a small scale pilot project. For the lab scale tests, three basic configurations were evaluated: using the iron/sand as a pre-filter, in the root bed. and as a post filter. Primary lagoon effluent was applied to the test cells to simulate actual CW conditions, and the total phosphorus and iron concentrations of the influent and effluent were nfK)nitored. The pilot scale trials were limited to using only a post filter design, due to in-progress research at the pilot site. The lab scale tests achieved average renrK>val efficiencies greater than 91% for all indoor configurations, and greater than 97% for all outdoor configurations. The pilot scale tests had an average renK)val efficiency of 60%. This relatively low efficiency in the pilot scale can be attributed to the post filters being only one tenth the size of the lab scale test in terms of hydraulic loading (6 cm/day vs. 60 cm/day).

Low frequency Raman scattering in amorphous materials: fused quartz, "pyrex" boro-silicate glass and soda-lime silicate glass

Raman scattering in the region 20 to 100 cm -1 for fused quartz, "pyrex" boro-silicate glass, and soft soda-lime silicate glass was investigated. The Raman spectra for the fused quartz and the pyrex glass were obtained at room temperature using the 488 nm exciting line of a Coherent Radiation argon-ion laser at powers up to 550 mW. For the soft soda-lime glass the 514.5 nm exciting line at powers up to 660 mW was used because of a weak fluorescence which masked the Stokes Raman spectrum. In addition it is demonstrated that the low-frequency Raman coupling constant can be described by a model proposed by Martin and Brenig (MB). By fitting the predicted spectra based on the model with a Gaussian, Poisson, and Lorentzian forms of the correlation function, the structural correlation radius (SCR) was determined for each glass. It was found that to achieve the best possible fit· from each of the three correlation functions a value of the SCR between 0.80 and 0.90 nm was required for both quartz and pyrex glass but for the soft soda-lime silicate glass the required value of the SCR. was between 0.50 and 0.60 nm .. Our results support the claim of Malinovsky and Sokolov (1986) that the MB model based on a Poisson correlation function provides a universal fit to the experimental VH (vertical and horizontal polarizations) spectrum for any glass regardless of its chemical composition. The only deficiency of the MB model is its failure to fit the experimental depolarization spectra.

Canadian Niagara Power Glass Slide - Group of men walking through the hydro tunnel

Four men (unidentified) walking in tunnel wearing hard hats and carrying flashlights.

Canadian Niagara Power Glass Slide - Engineer Drawing of Sections of Discharge Tunnel

Consulting Engineer drawing of Sections of the Discharge Tunnel. Included in the drawing is the "cross section of tunnel with timbering" and "longitudinal section showing Timber in straight tunnel". Dated October 1902.

Canadian Niagara Power Glass Slide - Engineer Drawing Hydro Station

Appears to be an engineer's drawing of the Hydro Station. It is a cross-section view of the interior.

Canadian Niagara Power Glass Slide - Plan and Profile of Discharge Tunnel

Plan and profile of discharge tunnel along Niagara River. The horizontal scale is 1 inch = 100 feet, the vertical scale is 1 inch = 40 feet. The drawing is dated November 7, 1902.