434 research outputs found
Funktionaaliset materiaalit selluloosasta ja bioväreistä
No full textDefence is held on 8.4.2022 12:00 – 15:00
https://aalto.zoom.us/j/66949163410Cellulose, an abundant and renewable material, that can be utilized as a nanomaterial as well as macroscopic fibers has obtained great attention for creating biomaterials for various applications. And color, an everyday phenomenon, is an essential part of almost any kind of material due to its symbolic and cultural meanings. The coloration of cellulosic and other materials is nowadays achieved mainly with synthetized dyes and pigments whose use has been identified especially as a source of aquatic pollution. The renewable biocolorants derived from natural sources are an interesting alternative to synthetic colorants.
The objective of this thesis was to investigate the functional materials made of cellulosics and biocolorants. Two different colorants from forest industry residues (willow bark extract and kraft lignin), high added-value crop Isatis tinctoria (indigo), and fast-growing microalgae Chlorella vulgaris were utilized as colorants for various cellulosic materials from cellulose nanofibrils (CNF), to microcrystalline cellulose, and macroscopic textile fibers. Unlike synthetized colorants, the biocolorants often are mixtures of multiple compounds and exhibit bioactive properties that can be incorporated into cellulosics to create added-value materials. The antioxidant and ultraviolet protecting properties were utilized to create biocomposite films useful for packaging applications. The antioxidant activity and CNF as a carrier matrix were utilized for developing the indigo dyeing towards a more facile process with fewer process steps. In the conventional dyeing process again, the multicomponent structure of biocolorants was found to be a significant feature since they all contribute to the interaction with dyeable cellulose material, dye fixation yield, and the overall result. The foamability and stability of lightweight foams from surfactant, cellulosics, and biocolorants were explored for creating camouflage foams with thermal and spectral stealth properties.
This thesis provides insights into the chemical and physical characteristics of biocolorants, understanding of the multicomponent nature and its effect on coloration, and introduces the potential practical applications for functional materials composed of cellulose and biocolorants.Selluloosa on uusiutuva ja runsaasti saatavilla oleva materiaali, jota voidaan hyödyntää sekä nano- että makrokokoisena, minkä takia se on kiinnostava biomateriaali moniin eri sovelluskohteisiin. Värit puolestaan ovat arkipäiväinen ilmiö ja tärkeä osa miltei kaikkia materiaaleja niiden symbolisten ja kulttuuristen merkitysten takia. Suurin osa materiaaleista, mukaan lukien selluloosapohjaiset kuidut, saavat värityksensä nykyisin syntetisoiduilla väriaineilla ja pigmenteillä, joiden on kuitenkin havaittu olevan yksi erityisesti vesistöjen saastumista aiheuttavista lähteistä. Luonnosta eristettävät biovärit ovat yksi kiinnostava vaihtoehto synteettisille väriaineille.
Tämän tutkimuksen tavoitteena oli tutkia selluloosamateriaaleista ja bioväreistä valmistettuja funktionaalisia materiaaleja. Bioväreiksi valikoitui neljä erilaista väriä, jotka saatiin metsäteollisuuden sivuvirroista (pajunkuoriuute ja kraft ligniini), korkean arvon värimorsinko (Isatis tinctoria) kasvista sekä nopeakasvuisesta mikrolevästä (Chlorella vulgaris). Selluloosamateriaaleina hyödynnettiin nanofibrilloitua ja mikrokiteistä sellulloosaa sekä tekstiilikuituja. Toisinkuin syntetisoidut väriaineet ja pigmentit, biovärit ovat koostumukseltaan seoksia ja ne omaavat usein värin lisäksi myös bioaktiivisia ominaisuuksia, jotka on mahdollista siirtää myös selluloosamateriaalin ja siten luoda lisäarvoa kyseiselle materiaalille. Näitä antioksidanttisia ja UV-valolta suojaavia ominaisuuksia hyödynnettiin esimerkiksi pakkausmateriaaleihin sopivien biokomposiittikalvojen valmistuksessa. Lisäksi antioksidanttisten ominaisuuksien ja nanoselluloosamatriisin yhdistelmää hyödynnettiin indigovärjäysprosessin kehittämisessä kestävämpään suuntaan. Yhden biovärin värjäysominaisuuksia tarkasteltiin myös perinteisessä värjäysprosessissa, ja tulokset paljastivat että biovärien seosmaisella koostumuksella on merkitystä värin komponenttien vuorovaikutukseen selluloosamateriaalin kanssa, kiinnittymisasteeseen ja visuaaliseen lopputulokseen. Lisäksi surfaktantista, selluloosasta ja bioväristä valmistettujen vaahtojen vaahtoutumista ja stabiiliutta tutkittiin visuaalista ja termistä suojaa tuovan häivevaahdon luomiseksi.
Tämä tutkimus tarjoaa uusia havaintoja biovärien kemiallisista ja fysikaalisista ominaisuuksista, ymmärrystä biovärien monikomponenttisuudesta ja sen vaikutuksista väritykseen sekä esittelee potentiaalisia käytännön sovelluskohteta selluloosasta ja bioväreistä valmistetuille funktionaalisille materiaaleille
Functional materials from cellulose and biocolorants
No full textCellulose, an abundant and renewable material, that can be utilized as a nanomaterial as well as macroscopic fibers has obtained great attention for creating biomaterials for various applications. And color, an everyday phenomenon, is an essential part of almost any kind of material due to its symbolic and cultural meanings. The coloration of cellulosic and other materials is nowadays achieved mainly with synthetized dyes and pigments whose use has been identified especially as a source of aquatic pollution. The renewable biocolorants derived from natural sources are an interesting alternative to synthetic colorants. The objective of this thesis was to investigate the functional materials made of cellulosics and biocolorants. Two different colorants from forest industry residues (willow bark extract and kraft lignin), high added-value crop Isatis tinctoria (indigo), and fast-growing microalgae Chlorella vulgaris were utilized as colorants for various cellulosic materials from cellulose nanofibrils (CNF), to microcrystalline cellulose, and macroscopic textile fibers. Unlike synthetized colorants, the biocolorants often are mixtures of multiple compounds and exhibit bioactive properties that can be incorporated into cellulosics to create added-value materials. The antioxidant and ultraviolet protecting properties were utilized to create biocomposite films useful for packaging applications. The antioxidant activity and CNF as a carrier matrix were utilized for developing the indigo dyeing towards a more facile process with fewer process steps. In the conventional dyeing process again, the multicomponent structure of biocolorants was found to be a significant feature since they all contribute to the interaction with dyeable cellulose material, dye fixation yield, and the overall result. The foamability and stability of lightweight foams from surfactant, cellulosics, and biocolorants were explored for creating camouflage foams with thermal and spectral stealth properties. This thesis provides insights into the chemical and physical characteristics of biocolorants, understanding of the multicomponent nature and its effect on coloration, and introduces the potential practical applications for functional materials composed of cellulose and biocolorants
Functional materials from cellulose and biocolorants
No full textCellulose, an abundant and renewable material, that can be utilized as a nanomaterial as well as macroscopic fibers has obtained great attention for creating biomaterials for various applications. And color, an everyday phenomenon, is an essential part of almost any kind of material due to its symbolic and cultural meanings. The coloration of cellulosic and other materials is nowadays achieved mainly with synthetized dyes and pigments whose use has been identified especially as a source of aquatic pollution. The renewable biocolorants derived from natural sources are an interesting alternative to synthetic colorants. The objective of this thesis was to investigate the functional materials made of cellulosics and biocolorants. Two different colorants from forest industry residues (willow bark extract and kraft lignin), high added-value crop Isatis tinctoria (indigo), and fast-growing microalgae Chlorella vulgaris were utilized as colorants for various cellulosic materials from cellulose nanofibrils (CNF), to microcrystalline cellulose, and macroscopic textile fibers. Unlike synthetized colorants, the biocolorants often are mixtures of multiple compounds and exhibit bioactive properties that can be incorporated into cellulosics to create added-value materials. The antioxidant and ultraviolet protecting properties were utilized to create biocomposite films useful for packaging applications. The antioxidant activity and CNF as a carrier matrix were utilized for developing the indigo dyeing towards a more facile process with fewer process steps. In the conventional dyeing process again, the multicomponent structure of biocolorants was found to be a significant feature since they all contribute to the interaction with dyeable cellulose material, dye fixation yield, and the overall result. The foamability and stability of lightweight foams from surfactant, cellulosics, and biocolorants were explored for creating camouflage foams with thermal and spectral stealth properties. This thesis provides insights into the chemical and physical characteristics of biocolorants, understanding of the multicomponent nature and its effect on coloration, and introduces the potential practical applications for functional materials composed of cellulose and biocolorants
Functional materials from cellulose and biocolorants
No full textCellulose, an abundant and renewable material, that can be utilized as a nanomaterial as well as macroscopic fibers has obtained great attention for creating biomaterials for various applications. And color, an everyday phenomenon, is an essential part of almost any kind of material due to its symbolic and cultural meanings. The coloration of cellulosic and other materials is nowadays achieved mainly with synthetized dyes and pigments whose use has been identified especially as a source of aquatic pollution. The renewable biocolorants derived from natural sources are an interesting alternative to synthetic colorants. The objective of this thesis was to investigate the functional materials made of cellulosics and biocolorants. Two different colorants from forest industry residues (willow bark extract and kraft lignin), high added-value crop Isatis tinctoria (indigo), and fast-growing microalgae Chlorella vulgaris were utilized as colorants for various cellulosic materials from cellulose nanofibrils (CNF), to microcrystalline cellulose, and macroscopic textile fibers. Unlike synthetized colorants, the biocolorants often are mixtures of multiple compounds and exhibit bioactive properties that can be incorporated into cellulosics to create added-value materials. The antioxidant and ultraviolet protecting properties were utilized to create biocomposite films useful for packaging applications. The antioxidant activity and CNF as a carrier matrix were utilized for developing the indigo dyeing towards a more facile process with fewer process steps. In the conventional dyeing process again, the multicomponent structure of biocolorants was found to be a significant feature since they all contribute to the interaction with dyeable cellulose material, dye fixation yield, and the overall result. The foamability and stability of lightweight foams from surfactant, cellulosics, and biocolorants were explored for creating camouflage foams with thermal and spectral stealth properties. This thesis provides insights into the chemical and physical characteristics of biocolorants, understanding of the multicomponent nature and its effect on coloration, and introduces the potential practical applications for functional materials composed of cellulose and biocolorants
Better outcomes for hospitalized patients with TIA when in stroke units: An observational study, Author Response (Editorial)
No full textEditors' Note: Drs. Phan and Srikanth point out that in “Better outcomes for hospitalized patients with TIA when in stroke units: An observational study,” the recurrence rate was much higher than that in an Australian rapid/outpatient-based TIA pathway. Inability to walk (which could indicate stroke instead of TIA), low usage of antiplatelet therapy, and time to antiplatelet therapy are possible explanations. In response, Cadilhac et al. comment that initiation of aspirin within several hours vs 24–48 hours has not been shown to clearly improve outcomes.No Full Tex
Capturing colloidal nano- and microplastics with plant-based nanocellulose networks
No full textFunding Information: This work has been done as a part of the Academy of Finland’s Flagship Programme under Projects No. 318890 and 318891 (Competence Centre for Materials Bioeconomy, FinnCERES) (I.L., T. Lap, T. Loh, C.J., T.T.). S.A. has been funded by the Academy of Finland’s postdoctoral project No. 311608/326262 (BoNC-Fi). We thank Katja Pettersson for technical assistance with AFM imaging. Funding Information: This work has been done as a part of the Academy of Finland?s Flagship Programme under Projects No. 318890 and 318891 (Competence Centre for Materials Bioeconomy, FinnCERES) (I.L., T. Lap, T. Loh, C.J., T.T.). S.A. has been funded by the Academy of Finland?s postdoctoral project No. 311608/326262 (BoNC-Fi). We thank Katja Pettersson for technical assistance with AFM imaging. Publisher Copyright: © 2022, The Author(s).Microplastics accumulate in various aquatic organisms causing serious health issues, and have raised concerns about human health by entering our food chain. The recovery techniques for the most challenging colloidal fraction are limited, even for analytical purposes. Here we show how a hygroscopic nanocellulose network acts as an ideal capturing material even for the tiniest nanoplastic particles. We reveal that the entrapment of particles from aqueous environment is primarily a result of the network’s hygroscopic nature - a feature which is further intensified with the high surface area of nanocellulose. We broaden the understanding of the mechanism for particle capture by investigating the influence of pH and ionic strength on the adsorption behaviour. We determine the nanoplastic binding mechanisms using surface sensitive methods, and interpret the results with the random sequential adsorption (RSA) model. These findings hold potential for the explicit quantification of the colloidal nano- and microplastics from different aqueous environments, and eventually, provide solutions to collect them directly on-site where they are produced.Peer reviewe
Selluloosamateriaalien värjääminen pajunkuoriuutteella
No full textThe usage of natural dyes has been gradually vanishing since synthetic dyes were discovered and nowadays the annual share of natural dyes is approximately 1 %. However, the increasing awareness of environmental issues has raised demand for more sustainable and eco-friendly dyes, which are not dependent on petrochemical source. The natural dyes can be extracted from various sources and nature offers a wide range of different colored compounds, which can be used to all materials ranging from protein-based fiber, to cellulose fibers and to synthetic fibers. Natural dyes are secondary metabolites, i.e. they provide protection for the plant against external stress, and thus natural dyes have potential to bring new functionalities to dyed materials. However, natural dyes have generally weaker light and wash fastness properties than synthetic dyes.
The main objective of this work was to study dyeing of four different cellulose-based materials with natural dye extracted from willow bark. The used cellulose materials were microcrystalline cellulose (MCC), Ioncell (IC), TEMPO oxidized cellulose nanofibrils (TEMPO-CNF) and pure cellulose paper. The influence of concentrations, pretreatments and dyeing conditions to final obtained color were analyzed by UV-Vis spectroscopy.
According to UV-Vis spectroscopy and visual observations, the highest mordant concentration yielded to the darkest color and improved also the wash fastness properties. The best biomordant in these experiments was oxalic acid, although control samples mordanted with alum yielded to the darkest shades. The obtained colors were deeper in MCC samples than in IC samples. WBE and cellulose-WBE mixtures were exposed to UV radiation and it was observed that the color was gradually darkened and the particle size increased. In addition, a self-standing and self-healing film was noticed to form at the air-liquid interface of WBE solution. The results showed also that WBE acted as crosslinking reagent in low solid content TEMPO-CNF hydrogel production. The characterization of WBE is quite novel and the compounds are very similar, which makes quantitative and qualitative analysis challenging. In the future, optimization of the characterization methods is essential in order to make natural dyeing process more controllable, which could eventually allow to scale-up natural dyeing to industrial levelLuonnonvärien käyttö on vähitellen vähentynyt synteettisten värien myötä ja nykysyin luonnonvärien vuotuinen osuus on noin 1 %. Lisääntynyt ympäristötietoisuus on kuitenkin herättänyt kysyntää ympäristöystävällisemmille ja kestävän kehityksen periaatteiden mukaisille väreille, jotka eivät ole riippuvaisia öljypohjaisista raaka-aineista. Luonnonvärejä voidaan uuttaa useista lähteistä, ja luonto tarjoaa laajan skaalan erilaisia värillisiä yhdisteitä, joilla voidaan värjätä materiaaleja proteiinipohjaisista selluloosapohjaisiin ja synteettisiin materiaaleihin. Luonnonvärit ovat usein sekundaarisia aineenvaihdunnan tuotteita, eli ne suojaavat kasvia ulkoisilta stressitekijöiltä, minkä takia luonnonväreillä on mahdollista tuoda uusia toiminnallisia ominaisuuksia värjätyille materiaaleille. Luonnonväreillä on kuitenkin yleisesti ottaen huonommat valon- ja pesunkestävyysominaisuudet kuin synteettisillä väreillä.
Työn tarkoituksena oli tutkia neljän erilaisen selluloosapohjaisen materiaalin värjäämistä pajunkuoriuutteella. Työssä käytetyt selluloosamateriaalit olivat mikrokiteinen selluloosa, Ioncell, TEMPO-hapetettu nanofibrillaarinen selluloosa ja puhdas selluloosapaperi. Pitoisuuksien, esikäsittelyiden ja värjäysolosuhteiden vaikutus saavutettuun sävyyn karakterisoitiin UV-Vis spektroskopialla.
UV-Vis spektrien ja visuaalisen tarkastelun perusteella voitiin päätellä, että korkealla puretepitoisuudella saatiin aikaan tummin väri ja parhain pesunkestävyys. Parhaaksi luonnonpuretteeksi kokeissa havaittiin oksaalihappo, vaikkakin kontrollinäytteet alunalla puretettuna tuottivat tummimmat sävyt. Aikaansaadut sävyt olivat tummempia mikrokiteisissä selluloosanäytteissä kuin Ioncell-näytteissä. Pajunkuoriuutetta ja pajunkuoriuuteella käsiteltyjä selluloosamateriaaleja altistettiin UV-säteilylle ja voitiin havaita värin tummuvan asteittain ja partikkelikoon kasvavan. Lisäksi kokeissa havaittiin, että pajunkuoriuuteliuoksen rajapinnalle muodostuu itsestään parantuva kalvo ja, että pajunkuoriuutteella voidaan ristisilloittaa nanoselluloosaliuosta ja siten tuottaa geelejä. Pajunkuoriuutteen karakterisointi on vielä suhteellisen uutta ja lisäksi sen sisältämät yhdisteet ovat samankaltaisia, minkä takia kvantitatiivinen ja kvalitatiivinen analyysi on haastavaa. Karakterisointimenetelmien optimointi on erittäin tärkeää, jotta luonnonväriprosessista saataisiin helpommin hallittava ja teolliseen mittakaavaan skaalautuva
Stakeholder perceptions on the role of community development corporations and resident participation
No full textCommunity Development Corporations (CDCs) were formed in the United States to address issues in urban communities and often work with municipal governments on these issues (Keating, 1997; Jennings, 2004). In some neighborhoods, CDCs seek to rebuild and revitalize communities that suffered from social unrest, while others react to the lack of government or inadequate programming addressing the economic and social maladies of urban communities. The work of CDCs requires the involvement of all community stakeholders – particularly city residents and public administrators. Does thedual relationship CDCs have with residents and local government suggest that they bring both closer together? This research studies this phenomenon by using Arnstein’s Ladder of Participation to examine the role CDCs play in cultivating citizen participation.Specifically, this study seeks to examine how community stakeholders perceive the roleCDCs play in fostering resident participation in local government. As a primary methodological tool for studying individual and group perspectives,Q-method was employed to empirically study community stakeholder perceptions ofCDCs. Key research findings suggest that: a) community stakeholders believe that CDCsare currently working to maintain the status quo of participation and advise that the Context of Conventional Participation (1995) is present, b) stakeholders overwhelmingly believe that CDCs should work to encourage participation that incorporates partnership, and c) there should be less distance between residents and decision making, thereby increasing opportunities for engagement. Through the exploration of the subjective, this study exposes the perspective ofresidents on citizen participation and identifies the need for a new direction of theory development that examines the creation of consensus and partnership building incommunity development organizations and initiatives. Furthermore, Conditions for Ideal Participation emerges from the data providing a practical guideline for strengthening participation in municipal government. Conclusions from this study have both theoretical and practical implications to the scholarly and administrative work comprised of public administration.Ph.D.Includes bibliographical referencesIncludes vitaby Tia Sherée Gayno
Cloud service provider comparison for “TIA” insurance system
No full textMūsdienās vairākas organizācijas vēlas atteikties no savas infrastruktūras, pārceļot izmantotos risinājumus mākoņpakalpojumu sniedzēju platformās, lai nodrošinātu labāku ātrdarbību, mērogojamību, pieejamību vai, piemēram, vienkārši samazinātu sistēmu uzturēšanas izmaksas. Autors ir piedalījies projektā, kurā tika veikta TIA Technology izstrādātās apdrošināšanas sistēmas TIA tehniskā analīze paralēli tās izstrādei ar mērķi to migrēt uz mākoņpakalpojumu platformu Microsoft Azure vai Oracle Cloud, analīzes rezultātā attiecīgajai TIA implementācijai arī veicot visu izstrādes procesā iesaistīto komponenšu migrāciju uz Oracle Cloud. Šī darba gaitā autors apskatīja Oracle Cloud un Microsoft Azure mākoņskaitļošanas platformas un to piedāvātās iespējas TIA darbības nodrošināšanai, aprakstīja migrācijas procesu, izaicinājumus, motivāciju, kā arī šīs rīcības stratēģiju. Autors arī projekta izstrādes laikā apkopoja iegūtās zināšanas un pieredzi ar mērķi piedāvāt vadlīnijas līdzīgas problēmas risināšanai – TIA apdrošināšanas sistēmas migrācijai uz mākoņpakalpojumu platformu Oracle Cloud.Nowadays many organizations would like to discard their on-premise infrastructure by moving their solutions to cloud service provider platforms to provide better performance, scalability, accessibility or just for maintenance cost reduction. Author has been involved in a project, where the insurance system TIA developed by TIA Technology has been technically analyzed in parallel with its development and customization with the aim to migrate it to cloud service provider platforms Microsoft Azure or Oracle Cloud. After analysis this TIA implementation was migrated with all involved development process components to Oracle OCI. This paper describes author’s research regarding Oracle Cloud and Microsoft Azure cloud service provider platforms and their provided options to ensure operation of TIA, migration process, challenges, motivation, and action strategy. As a result, author summarized the obtained knowledge and experience with an intention to provide guidelines necessary to solve a similar problem – TIA insurance system migration to Oracle Cloud
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