73 research outputs found
Innovation in sustainable construction materials and the circular economy
No full textAlthough the construction sector is typically highly conservative and risk averse, the opportunities for innovation in construction materials and related technologies have never been greater. This is being driven by factors such as the need to deliver low-carbon sustainable infrastructure, the use of materials with improved durability and performance, the opportunities to develop multi-functional and smart materials and the circular economy. However, much of the research and development reported in this area, while valuable and technically competent, is relatively incremental and limited in scope. There are of course, good reasons for this, but there is also a need for more innovative research to address some of the issues in construction and infrastructure materials. Universities are often the best place for this type of research given their opportunities to complete research with higher associated risk. This paper provides examples of innovation in construction materials that has been driven by the need to develop a circular economy. The examples are based primarily on the work of the author and associated collaborators
Celmisia brevifolia Cheeseman 1925
No full text<p> <b>11.</b> <i>Celmisia brevifolia</i> Cockayne ex Cheeseman (1925: 938).</p> <p> Type:—NEW ZEALAND. South Island, Plateau of the Old Man Range in herb-moor, 1500 m. alt., 27 March 1919, <i>L. Cockayne 1970</i> (lectotype K 77065 [image!] designated here; isolectotype WELT SP45774!).</p> <p> <b>Notes:—</b> Cheeseman (1925) described <i>C. brevifolia</i> and cited several syntypes that include plants with quite different leaf appearances regarding shape and indumentum. Plants from the Old Man Range (<i>L. Cockayne 1970</i>, see typification) and some from Mt Pisa (<i>L. Cockayne 1978</i>, K 77064 [image!], WELT SP45775!, SP45776!), both in Central Otago, have leaves obovate and pseudopetiolate, upon which Allan (1961: 618) wrote: “Neither type locality nor type is indicated, but Central Otago plants included by Cheeseman are fairly uniform […]”. Another syntype from Mt. Pisa (SP46497!) and one collected at Mt Ernest in northwest Otago (AK 34925!) have leaves that vary from obovate, obovate-oblong, oblanceolate-oblong, to almost linear-oblong, approaching <i>C. angustifolia</i>. Additional syntypes (AK 9707!, 9708!, AK 9709!, 9710!, AK 9706!, WELT SP46498!) coming from the Two Thumb Range in South Canterbury, have a conspicuous white arachnoid indumentum covering most of the adaxial surface (note that the syntypes mentioned above and the typical <i>C. angustifolia</i> are glabrous on the adaxial surface) and leaves oblanceolate-oblong to linearoblong, almost identical to <i>C. angustifolia</i> from its typical area (Torlesse Range, see typification of <i>C. angustifolia</i>).</p> <p> Plants from the Old Man Range are quite uniform in leaf shape and are representative of the taxon commonly recognized as <i>Celmisia brevifolia</i> that occurs mainly in Central Otago (Allan 1961, Mark & Adams 1973) as indicated above.Therefore, I have chosen the material from this locality (<i>L. Cockayne 1970</i>) as a lectotype. Besides, this specimen corresponds to a branch with leaves and one scape with a complete involucre, morphological features that allow its appropriate identification.</p> <p> Cheeseman ascribed the name <i>C. brevifolia</i> to Cockayne, however, according to the ICN Art. 46.5 and 46.6 (Turland <i>et al</i>. 2018), the author can be cited either as <i>C. brevifolia</i> Cheeseman or as <i>C. brevifolia</i> Cockayne ex Cheeseman.</p>Published as part of <i>Saldivia, Patricio, 2023, Nomenclature and typifications in Celmisia (Asteraceae: Astereae): The New Zealand endemic subgenera Caespitosae, Glandulosae, and Lignosae, pp. 31-45 in Phytotaxa 591 (1)</i> on pages 35-36, DOI: 10.11646/phytotaxa.591.1.3, <a href="http://zenodo.org/record/7784168">http://zenodo.org/record/7784168</a>
Magnesium-based glasses prepared by sol-gel processing for use as supplementary cementitious materials
No full textAbstract
For decades, supplementary cementitious materials (SCMs) have been utilized as clinker substitutes as one of the strategies to mitigate the CO2 emissions associated with Portland cement production. However, traditional SCMs (e.g., coal fly ash, silica fume, and blast furnace slag) are being phased out, as they are insufficient to enable high volume clinker substitution. Therefore, alternative SCMs are actively being sought to meet market demand. Synthetic glasses may be a potential source of SCMs due to their pozzolanic activity and tunable properties. The chemical composition of glasses determines their pozzolanic activity, with Ca-based glasses being predominantly studied owing to their high reactivity. However, this leads to the same inherent CO2 emissions as for cement, originating from the production of CaO from CaCO3.
This thesis investigates Mg-based silicate glasses synthesized via the sol-gel method, tuning their composition for higher pozzolanic activity. The feasibility of using Mg-based silicate glasses as SCMs was studied through three main pathways:
(1) Development of a binary Mg-Si sol-gel glass system: The impact of varying Mg concentrations on the glass reactivity was assessed (Publication Ⅰ).
(2) Introduction of Fe into the Mg-Si system: Varying concentrations of Fe3+/ Fe2+ were incorporated into Mg-Si glasses, investigating changes in reactivity (Publications Ⅱ, Ⅲ).
(3) Assessment of cementitious performance: The pozzolanic activity of Mg-based glasses was evaluated, and their impact on the properties and performance of cementitious systems was studied (Publication Ⅳ).
The research revealed the high elemental solubility of the synthetic glasses, indicating their high reactivity, and demonstrated pozzolanic activity exceeding that of conventional SCMs such as fly ash slag. These findings provide a preliminary assessment of the potential for using Mg silicate glasses as novel SCMs with the aim of reducing CO2 emissions. Original papers Jiang, C., Ramteke, D. D., Li, J., Sliz, R., Sreenivasan, H., Cheeseman, C., & Kinnunen, P. (2023). Preparation and characterization of binary Mg-silicate glasses via Sol-Gel route. Journal of Non-Crystalline Solids, 606, 122204. https://doi.org/10.1016/j.jnoncrysol.2023.122204 https://doi.org/10.1016/j.jnoncrysol.2023.122204 Self-archived version Jiang, C., Santos, H. S., Yliniemi, J., Lindén, J., Ramteke, D. D., Illikainen, M., Cheeseman, C., & Kinnunen, P. (2024). Fe-bearing magnesium silicate glasses for potential supplementary cementitious applications. Frontiers in Materials, 11, 1509403. https://doi.org/10.3389/fmats.2024.1509403 https://doi.org/10.3389/fmats.2024.1509403 Self-archived version Jiang, C., Yliniemi, J., Santos, H. S., Lindén, J., Ramteke, D.D., Cheeseman, C., & Kinnunen, P. (2024). Optimizing Fe(II)/Fe(III)-bearing magnesium silicate glasses for applications in supplementary cementitious materials. Manuscript submitted for publication. Jiang, C., Santos, H. S., Ahmad, L., Yliniemi, J., Cheeseman, C., & Kinnunen, P. (2025). Properties of Fe-bearing Mg silicate glasses as novel supplementary cementitious materials. Manuscript submitted for publication. Tiivistelmä
Jo vuosikymmenten ajan sementin seosaineita (SCM) on käytetty klinkkerin korvikkeina tavoitteena vähentää portlandsementin tuotannossa syntyviä CO2-päästöjä. Perinteisten SCM-materiaalien, kuten lentotuhkan, silikajauheen ja masuunikuonan, saatavuus ei kuitenkaan riitä mahdollistamaan korkeaa klinkkerin korvausastetta. Siksi on tarpeen kehittää uusia SCM-materiaaleja markkinoiden tarpeiden täyttämiseksi. Synteettiset lasit voivat olla potentiaalinen vaihtoehto niiden potsolaanisen aktiivisuuden ja säädettävien ominaisuuksien ansiosta. Lasien kemiallinen koostumus määrittää niiden potsolaanisen aktiivisuuden, ja enimmäkseen on tutkittu Ca-pohjaisia laseja niiden korkean reaktiivisuuden vuoksi. Tämä johtaa kuitenkin samoihin luontaisiin CO2-päästöihin kuin sementin tuotannossa, koska CaO:ta tuotetaan CaCO3:sta.
Tämä väitöskirja tutkii Mg-pohjaisia silikaattilaseja, jotka tuotetaan sol-gel-menetelmällä, jossa lasien koostumusta säädetään korkeamman potsolaanisen aktiivisuuden saavuttamiseksi. Mg-pohjaisten silikaattilasien käyttökelpoisuutta SCM-materiaaleina tutkittiin kolmen pääasiallisen lähestymistavan kautta:
(1) Binaarisen Mg-Si sol-gel-lasin kehitys: Eri Mg-pitoisuuksien vaikutuksia lasin reaktiivisuuteen arvioitiin (julkaisu I).
(2) Fe:n lisääminen Mg-Si-järjestelmään: Mg-Si-laseihin lisättiin eri pitoisuuksia Fe3+/Fe2+:aa, ja niiden vaikutusta reaktiivisuuteen tutkittiin (julkaisut II, III).
(3) Sementtimäisen suorituskyvyn arviointi: Mg-pohjaisten lasien potsolaanista aktiivisuutta arvioitiin, ja niiden vaikutusta seostettujen sementtien ominaisuuksiin ja suorituskykyyn tutkittiin (julkaisu IV).
Tutkimus paljastaa synteettisten lasien korkean alkuaineliukoisuuden, mikä viittaa niiden korkeaan reaktiivisuuteen, sekä osoittaa, että niiden potsolaaninen aktiivisuus ylittää perinteiset SCM:t, kuten lentotuhkan ja kuonan. Nämä havainnot tarjoavat alustavan arvion Mg-silikaattilasien potentiaalista uusina SCM-materiaaleina, joiden tavoitteena on CO2-päästöjen vähentäminen. Osajulkaisut Jiang, C., Ramteke, D. D., Li, J., Sliz, R., Sreenivasan, H., Cheeseman, C., & Kinnunen, P. (2023). Preparation and characterization of binary Mg-silicate glasses via Sol-Gel route. Journal of Non-Crystalline Solids, 606, 122204. https://doi.org/10.1016/j.jnoncrysol.2023.122204 https://doi.org/10.1016/j.jnoncrysol.2023.122204 Rinnakkaistallennettu versio Jiang, C., Santos, H. S., Yliniemi, J., Lindén, J., Ramteke, D. D., Illikainen, M., Cheeseman, C., & Kinnunen, P. (2024). Fe-bearing magnesium silicate glasses for potential supplementary cementitious applications. Frontiers in Materials, 11, 1509403. https://doi.org/10.3389/fmats.2024.1509403 https://doi.org/10.3389/fmats.2024.1509403 Rinnakkaistallennettu versio Jiang, C., Yliniemi, J., Santos, H. S., Lindén, J., Ramteke, D.D., Cheeseman, C., & Kinnunen, P. (2024). Optimizing Fe(II)/Fe(III)-bearing magnesium silicate glasses for applications in supplementary cementitious materials. Manuscript submitted for publication. Jiang, C., Santos, H. S., Ahmad, L., Yliniemi, J., Cheeseman, C., & Kinnunen, P. (2025). Properties of Fe-bearing Mg silicate glasses as novel supplementary cementitious materials. Manuscript submitted for publication. Academic dissertation to be presented with the assent of the Doctoral Programme Committee of Technology and Natural Sciences of the University of Oulu for public defence in the Wetteri auditorium (IT115), Linnanmaa, on 25 April 2025, at 12 noonAbstract
For decades, supplementary cementitious materials (SCMs) have been utilized as clinker substitutes as one of the strategies to mitigate the CO2 emissions associated with Portland cement production. However, traditional SCMs (e.g., coal fly ash, silica fume, and blast furnace slag) are being phased out, as they are insufficient to enable high volume clinker substitution. Therefore, alternative SCMs are actively being sought to meet market demand. Synthetic glasses may be a potential source of SCMs due to their pozzolanic activity and tunable properties. The chemical composition of glasses determines their pozzolanic activity, with Ca-based glasses being predominantly studied owing to their high reactivity. However, this leads to the same inherent CO2 emissions as for cement, originating from the production of CaO from CaCO3.
This thesis investigates Mg-based silicate glasses synthesized via the sol-gel method, tuning their composition for higher pozzolanic activity. The feasibility of using Mg-based silicate glasses as SCMs was studied through three main pathways:
(1) Development of a binary Mg-Si sol-gel glass system: The impact of varying Mg concentrations on the glass reactivity was assessed (Publication Ⅰ).
(2) Introduction of Fe into the Mg-Si system: Varying concentrations of Fe3+/ Fe2+ were incorporated into Mg-Si glasses, investigating changes in reactivity (Publications Ⅱ, Ⅲ).
(3) Assessment of cementitious performance: The pozzolanic activity of Mg-based glasses was evaluated, and their impact on the properties and performance of cementitious systems was studied (Publication Ⅳ).
The research revealed the high elemental solubility of the synthetic glasses, indicating their high reactivity, and demonstrated pozzolanic activity exceeding that of conventional SCMs such as fly ash slag. These findings provide a preliminary assessment of the potential for using Mg silicate glasses as novel SCMs with the aim of reducing CO2 emissions.Tiivistelmä
Jo vuosikymmenten ajan sementin seosaineita (SCM) on käytetty klinkkerin korvikkeina tavoitteena vähentää portlandsementin tuotannossa syntyviä CO2-päästöjä. Perinteisten SCM-materiaalien, kuten lentotuhkan, silikajauheen ja masuunikuonan, saatavuus ei kuitenkaan riitä mahdollistamaan korkeaa klinkkerin korvausastetta. Siksi on tarpeen kehittää uusia SCM-materiaaleja markkinoiden tarpeiden täyttämiseksi. Synteettiset lasit voivat olla potentiaalinen vaihtoehto niiden potsolaanisen aktiivisuuden ja säädettävien ominaisuuksien ansiosta. Lasien kemiallinen koostumus määrittää niiden potsolaanisen aktiivisuuden, ja enimmäkseen on tutkittu Ca-pohjaisia laseja niiden korkean reaktiivisuuden vuoksi. Tämä johtaa kuitenkin samoihin luontaisiin CO2-päästöihin kuin sementin tuotannossa, koska CaO:ta tuotetaan CaCO3:sta.
Tämä väitöskirja tutkii Mg-pohjaisia silikaattilaseja, jotka tuotetaan sol-gel-menetelmällä, jossa lasien koostumusta säädetään korkeamman potsolaanisen aktiivisuuden saavuttamiseksi. Mg-pohjaisten silikaattilasien käyttökelpoisuutta SCM-materiaaleina tutkittiin kolmen pääasiallisen lähestymistavan kautta:
(1) Binaarisen Mg-Si sol-gel-lasin kehitys: Eri Mg-pitoisuuksien vaikutuksia lasin reaktiivisuuteen arvioitiin (julkaisu I).
(2) Fe:n lisääminen Mg-Si-järjestelmään: Mg-Si-laseihin lisättiin eri pitoisuuksia Fe3+/Fe2+:aa, ja niiden vaikutusta reaktiivisuuteen tutkittiin (julkaisut II, III).
(3) Sementtimäisen suorituskyvyn arviointi: Mg-pohjaisten lasien potsolaanista aktiivisuutta arvioitiin, ja niiden vaikutusta seostettujen sementtien ominaisuuksiin ja suorituskykyyn tutkittiin (julkaisu IV).
Tutkimus paljastaa synteettisten lasien korkean alkuaineliukoisuuden, mikä viittaa niiden korkeaan reaktiivisuuteen, sekä osoittaa, että niiden potsolaaninen aktiivisuus ylittää perinteiset SCM:t, kuten lentotuhkan ja kuonan. Nämä havainnot tarjoavat alustavan arvion Mg-silikaattilasien potentiaalista uusina SCM-materiaaleina, joiden tavoitteena on CO2-päästöjen vähentäminen
Processing the problematic fine fraction of incinerator bottom ash into a raw material for manufacturing ceramics
No full textThe aim of this research was to develop a novel thermal treatment technology able to transform the problematic fine fraction of incinerator bottom ash (IBA) into an inert material suitable for the production of ceramics.
In this project two different problematic fractions of fine IBA have been used. The less than 1mm fraction of processed fine IBA dust was obtained from the dry discharge system for IBA used in the Energy from Waste (EfW) plant at Monthey, Zurich. The dry discharged fine IBA dust from the Monthey plant is currently disposed of to landfill at high cost. The second fine IBA fraction was supplied by Day Group who process wet discharge IBA from the Lakeside and the Newhaven EfW facilities in the South of England. There are currently no beneficial uses for the fine fraction which is either blended back into coarser fractions or disposed of to landfill.
The conclusion from the research is that the fine fractions of IBA generated from both discharge techniques can be transformed into an inert material suitable for the production of hard, dense ceramics. Processing involves the addition of glass, wet ball milling and calcining, pressing and sintering. The addition of glass aids liquid phase sintering and improves the appearance of the ceramic body formed, milling increases sintering reactivity and calcining limits the loss of volatiles and shrinkage during firing. This transforms the major crystalline phases present in the fine IBA fraction from quartz (SiO2), calcite (CaCO3), gehlenite (Ca2Al2SiO7) and hematite (Fe2O3), to the pyroxene group minerals diopside (CaMgSi2O6) and clinoenstatite (MgSi2O6), together with some andradite (Ca3Fe2Si3O12). Processed calcined powders can be pressed and sintered to form dense (>2.5 g/cm3), hard ceramics that exhibit low firing shrinkage (<7%), zero water absorption and minimal leaching. Calcining the IBA: glass powders before processing was able to minimize the linear shrinkage observed compared to samples produced using uncalcined powders. Calcining also had the effect of reducing the leaching of metals of environmental concern present in the fine IBA fraction by over 95%. These are encapsulated within the glassy phases present in the calcined and sintered materials.Open Acces
A Regulatory Switch Alters Chromosome Motions at the Metaphase-to-Anaphase Transition
No full textSummaryTo achieve chromosome segregation during mitosis, sister chromatids must undergo a dramatic change in their behavior to switch from balanced oscillations at the metaphase plate to directed poleward motion during anaphase. However, the factors that alter chromosome behavior at the metaphase-to-anaphase transition remain incompletely understood. Here, we perform time-lapse imaging to analyze anaphase chromosome dynamics in human cells. Using multiple directed biochemical, genetic, and physical perturbations, our results demonstrate that differences in the global phosphorylation states between metaphase and anaphase are the major determinant of chromosome motion dynamics. Indeed, causing a mitotic phosphorylation state to persist into anaphase produces dramatic metaphase-like oscillations. These induced oscillations depend on both kinetochore-derived and polar ejection forces that oppose poleward motion. Thus, our analysis of anaphase chromosome motion reveals that dephosphorylation of multiple mitotic substrates is required to suppress metaphase chromosome oscillatory motions and achieve directed poleward motion for successful chromosome segregation
Longevity of blanket forts as a measure of caregiver distress during the 2020 Coronavirus pandemic
No full textThe Journal of Imaginary Research responded to the crisis many academics during the early months of the Coronavirus pandemic by offering a call-out for a special edition of 'Imaginary Research' and fantastical author biographies. This comedic short fiction piece takes the form of a scientific journal article, but the research is, as the title suggests, imaginary
The effects of growth salinity and irradiance on thylakoid stacking in lettuce plants
No full textThe basic objective of this research, which emphasizes the dynamic nature of thylakoid stacking, was to elaborate on the responsiveness of thylakoid membrane stacking to environmental conditions in order to investigate the role of stacking in the adaptive processes of photosynthesis. By integrating the information on salinity-induced cation changes in leaves with information on the in vitro effects of cations on thylakoid stacking, we provided a basis for testing the sensitivity of the stacking process to growth salinity, an environmental factor which had not been previously discussed in those terms. We accomplished this by using methods of digitonin fractionation to show that growth salinity altered the degree of thylakoid stacking in lettuce plants. Furthermore, we established that growth salinity and irradiance interacted in such a way that the moderate salinization of the nutrient solution was associated with less stacking at high irradiances and more stacking at low irradiances, both relative to controls.Attention was also given to the relationship of thylakoid stacking and photosynthetic efficiency in mature leaves. Using different combinations of growth salinity and irradiance to manipulate the degrees of stacking, our results suggested a positive correlation between the degree of stacking and the photon yield of O\sb2 evolution. Another consideration was the susceptibility of high-irradiance lettuce plants to photoinhibition based on salinity-induced differences in thylakoid stacking. Overall, high-irradiance plants in which thylakoid stacking had been reduced by growth salinity showed fewer signs of photoinhibition than high-irradiance plants with more stacking.Made available in DSpace on 2011-05-07T12:03:46Z (GMT). No. of bitstreams: 2
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Characterization of sodium transport at the plasma membrane of Spergularia marina
No full textPlants vary in their whole plant strategies for managing the sodium (Na\sp{+}) present in their environment, but current models predict that they have a common strategy at the cellular level: exclusion from the cytoplasm. This entails either passive exclusion mediated by low plasma membrane permeability or active exclusion of passively acquired Na\sp{+} which has moved down its electrochemical gradient into the cell. Whole plant studies using the halophyte Spergularia marina have demonstrated high permeability for Na\sp{+} into and out of root cells and the research reported here investigates these mechanisms by directly measuring Na\sp{+} transport using radiolabelled Na\sp{+} and sealed plasma membrane vesicles from the roots of this species. This is the first report to characterize \sp{22}Na\sp{+} transport using plant plasma membrane vesicles.Fractions from discontinuous and linear gradients of sucrose that were enriched in plasma membrane vesicles were identified for use in the \sp{22}Na\sp{+} transport studies by the orthovanadate-sensitive P-type H\sp{+}-ATPase activity associated with them. Both the scalar and vectoral components of the activity were found to have negligible Na\sp{+}-dependent modifications. Indirect Na\sp{+}-dependent effects were observed, suggesting that Na\sp{+} could disrupt K\sp{+}-dependent modifications of both components of the ATPase activity. An alternative explanation of the data was that an ATP-dependent, orthovanadate-insensitive, Na\sp{+}-dependent transport mechanism(s) mediated vesicle acidification. Radiolabelled Na\sp{+} transport studies using similar conditions failed to show the presence of ATP-dependent transport of Na\sp{+}; and in addition, vesicle acidification studies, as well as \sp{22}Na\sp{+} transport studies, suggested that a Na\sp{+}/H\sp{+} antiport mechanism was not present in the plasma membrane. Two \Delta\mu\sb{\rm Na+}-driven transport mechanisms were identified using efflux studies. Lineweaver-Burk analysis predicted the presence of a Na\sp{+} transport mechanism with a K\sb{\rm m} of 93 mM Na\sp{+} and a V\sb{\rm max} of 52.6 nmoles Na\sp{+} (mg prot min)\sp{-1}. Studies with monensin suggested that there was a Na\sp{+}-dependent alkalinization of the vesicles when the \Delta\mu\sb{\rm Na+} was high.Made available in DSpace on 2011-05-07T12:13:57Z (GMT). No. of bitstreams: 2
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