2,382 research outputs found
POTENTIAL APPLICATIONS FOR SHARED-SERVICES COOPERATIVES IN NORTH DAKOTA
No full textThe principal goal of shared-services cooperatives is to capture savings through lower administrative costs, quantity purchasing discounts, sharing fixed costs, and assured levels of business with vendors and suppliers. Although the idea of cooperation is not new in North Dakota, the question raised here is whether there is potential applications for non-agricultural shared-services cooperatives that provide services that are absent or inadequate in rural communities in the state. It is concluded that there is potential application for shared-services cooperatives in both public and private sectors in North Dakota based on opportunities to share fixed costs and to capitalize on pecuniary economies of size.shared-services cooperatives, non-agricultural cooperatives, North Dakota, Agribusiness,
Highly porous alkali activated foams for water and wastewater treatment
No full textAbstract
Alkali-activated materials (AAMs) have diverse applications in water and wastewater treatment. In this thesis, porous AAM foams were prepared with the goal to explore their potential use in new applications for water and wastewater treatment, namely adsorptive filters, point-of-use water disinfection, and separation of microplastics.
The adsorptive filters were prepared from blast furnace slag and optimized by comparing five different surfactants and doses of H2O2. Porous AAM exhibiting the highest mechanical strength was investigated for methylene blue adsorption. To further enhance the adsorption performance, a lignin-containing composite foam was prepared. In the dynamic adsorption experiments, the highest adsorption amount obtained with the lignin-composite foam was ~40 mg/g. Moreover, peracetic acid was investigated as an alternative foaming agent in the preparation of porous AAMs. During the investigation, lower volume expansion and faster reaction kinetics with reduced setting time were observed for peracetic acid-based porous AAM compared to H2O2-based porous AAM.
To develop material for point-of-use water disinfection, the first goal was to achieve comparable water permeability to traditional ceramic filters by varying the amount of hydrogen peroxide. An optimized foam was then treated with colloidal Ag solution to explore its potential use in disinfecting water for 10 weeks. The modified foam demonstrated a significant reduction (2.84 log10 units) in E. coli bacteria compared to an unmodified filter (1.57 log10 units). Additionally, the environmental impact of the porous AAM was analyzed through life cycle assessment and found to be lower than that of conventional ceramic filter.
Finally, to develop material capable of separating microplastics, porous AAM surface was modified with triethoxy(octyl)silane to render it superhydrophobic. The modified porous AAM demonstrated over 99% separation efficiency when treating 30 L of model water containing 5 mg/L of polyethylene microspheres (53-63 μm). Its performance was also evaluated in treating laundry effluent, where the modified porous AAM achieved approximately 84% separation compared to around 52% for the unmodified porous AAM. Original papers Bhuyan, M. A. H., Gebre, R. K., Finnilä, M. A. J., Illikainen, M., & Luukkonen, T. (2022). Preparation of filter by alkali activation of blast furnace slag and its application for dye removal. Journal of Environmental Chemical Engineering, 10(1), 107051. https://doi.org/10.1016/j.jece.2021.107051 https://doi.org/10.1016/j.jece.2021.107051 Self-archived version Bhuyan, M. A. H., & Luukkonen, T. (2024). Adsorption of methylene blue by composite foams containing alkali-activated blast furnace slag and lignin. International Journal of Environmental Science and Technology, 21(4), 3789–3802. https://doi.org/10.1007/s13762-023-05245-5 https://doi.org/10.1007/s13762-023-05245-5 Self-archived version Bhuyan, M. A. H., Kurtulus, C., Heponiemi, A., & Luukkonen, T. (2023). Peracetic acid as a novel blowing agent in the direct foaming of alkali-activated materials. Applied Clay Science, 231, 106727. https://doi.org/10.1016/j.clay.2022.106727 https://doi.org/10.1016/j.clay.2022.106727 Self-archived version Bhuyan, M. A. H., Karkman, A., Prokkola, H., Chen, B., Perumal, P., & Luukkonen, T. (2024). Alkali-activated foams coated with colloidal Ag for point-of-use water disinfection. ACS ES&T Water, 4(2), 687–697. https://doi.org/10.1021/acsestwater.3c00711 https://doi.org/10.1021/acsestwater.3c00711 Self-archived version Bhuyan, M. A. H., Busquets, R., Campos, L. C., & Luukkonen, T. (2024). Separation of microplastics from water using superhydrophobic silane-coupling-agent-modified geopolymer foam. Separation and Purification Technology, 339, 126709. https://doi.org/10.1016/j.seppur.2024.126709 https://doi.org/10.1016/j.seppur.2024.126709 Self-archived version Abstrakti
Alkaliaktivoiduilla materiaaleilla on runsaasti erilaisia sovelluksia veden ja jäteveden käsittelyssä. Tässä väitöskirjassa valmistettiin huokoisia alkaliaktivoituja vaahtoja tavoitteena selvittää niiden uusia hyödyntämismahdollisuuksia adsorboivina suodatinmateriaaleina, veden desinfioinnissa ja mikromuovin erottamisessa.
Masuunikuonasta valmistettujen adsorboivien suodattimien koostumus optimoitiin muuttamalla valmistuksessa käytetyn pinta-aktiivisen aineen tyyppiä sekä vaahdotinaineena toimivan vetyperoksidin lisäysmäärää. Optimoidulla materiaalilla tutkittiin metyleenisinisen adsorptiota vedestä. Adsorptiokyvyn lisäämiseksi valmistettiin ligniiniä sisältävää komposiittimateriaalia. Dynaamisessa metyleenisinisen adsorptiokokeessa suurin adsorptiomäärä ligniinikomposiitille oli ~40 mg/g. Lisäksi peretikkahappoa tutkittiin vaihtoehtoisena vaahdotusaineena. Peretikkahappoa käytettäessä havaittiin pienempi turpoaminen valmistuksen aikana ja lyhyempi kovettumisaika verrattuna vetyperoksidilla valmistettuihin vaahtoihin.
Tutkimuksen seuraavassa osassa tutkittiin veden desinfiointia. Alkaliaktivoituja vaahtoja valmistettiin metakaoliinista, masuunikuonasta ja niiden seoksista tavoitteena saavuttaa samanlainen veden läpäisevyys kuin keraamisilla suodattimilla. Tämän jälkeen optimoitua vaahtoa käsiteltiin kolloidisella hopealiuoksella ja sen käyttömahdollisuuksia veden desinfioinnissa tutkittiin 10 viikon ajan. Hopeaa sisältävä vaahto osoitti merkittävää E. coli -bakteerien vähenemistä (2,84 log10) verrattuna hopeaa sisältämättömään suodattimeen (1,57 log10). Lisäksi alkaliaktivoidun vaahdon ympäristövaikutuksia analysoitiin elinkaariarvioinnin avulla ja niiden todettiin olevan pienempiä kuin perinteisen keraamin.
Mikromuovien erottamiseksi alkaliaktivoituja vaahtoja käsiteltiin trietoksi(oktyyli)silaanilla superhydrofobisen pinnan luomiseksi. Käsitelty vaahto poisti yli 99 % mikromuovista kokeessa, jossa käsiteltiin 30 litraa vettä, joka sisälsi 5 mg/l polyetyleenipartikkeleita (koko 53–63 μm). Käsitellyn vaahdon suorituskykyä arvioitiin myös pyykinpesuveden käsittelyssä, jossa sen muovin poistokyky oli noin 84 % kun taas ei-käsitelty vaahto poisti vain 52 %. Osajulkaisut Bhuyan, M. A. H., Gebre, R. K., Finnilä, M. A. J., Illikainen, M., & Luukkonen, T. (2022). Preparation of filter by alkali activation of blast furnace slag and its application for dye removal. Journal of Environmental Chemical Engineering, 10(1), 107051. https://doi.org/10.1016/j.jece.2021.107051 https://doi.org/10.1016/j.jece.2021.107051 Rinnakkaistallennettu versio Bhuyan, M. A. H., & Luukkonen, T. (2024). Adsorption of methylene blue by composite foams containing alkali-activated blast furnace slag and lignin. International Journal of Environmental Science and Technology, 21(4), 3789–3802. https://doi.org/10.1007/s13762-023-05245-5 https://doi.org/10.1007/s13762-023-05245-5 Rinnakkaistallennettu versio Bhuyan, M. A. H., Kurtulus, C., Heponiemi, A., & Luukkonen, T. (2023). Peracetic acid as a novel blowing agent in the direct foaming of alkali-activated materials. Applied Clay Science, 231, 106727. https://doi.org/10.1016/j.clay.2022.106727 https://doi.org/10.1016/j.clay.2022.106727 Rinnakkaistallennettu versio Bhuyan, M. A. H., Karkman, A., Prokkola, H., Chen, B., Perumal, P., & Luukkonen, T. (2024). Alkali-activated foams coated with colloidal Ag for point-of-use water disinfection. ACS ES&T Water, 4(2), 687–697. https://doi.org/10.1021/acsestwater.3c00711 https://doi.org/10.1021/acsestwater.3c00711 Rinnakkaistallennettu versio Bhuyan, M. A. H., Busquets, R., Campos, L. C., & Luukkonen, T. (2024). Separation of microplastics from water using superhydrophobic silane-coupling-agent-modified geopolymer foam. Separation and Purification Technology, 339, 126709. https://doi.org/10.1016/j.seppur.2024.126709 https://doi.org/10.1016/j.seppur.2024.126709 Rinnakkaistallennettu versio 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 Arina auditorium (TA105), Linnanmaa, on 3 May 2024, at 12 noonAbstract
Alkali-activated materials (AAMs) have diverse applications in water and wastewater treatment. In this thesis, porous AAM foams were prepared with the goal to explore their potential use in new applications for water and wastewater treatment, namely adsorptive filters, point-of-use water disinfection, and separation of microplastics.
The adsorptive filters were prepared from blast furnace slag and optimized by comparing five different surfactants and doses of H2O2. Porous AAM exhibiting the highest mechanical strength was investigated for methylene blue adsorption. To further enhance the adsorption performance, a lignin-containing composite foam was prepared. In the dynamic adsorption experiments, the highest adsorption amount obtained with the lignin-composite foam was ~40 mg/g. Moreover, peracetic acid was investigated as an alternative foaming agent in the preparation of porous AAMs. During the investigation, lower volume expansion and faster reaction kinetics with reduced setting time were observed for peracetic acid-based porous AAM compared to H2O2-based porous AAM.
To develop material for point-of-use water disinfection, the first goal was to achieve comparable water permeability to traditional ceramic filters by varying the amount of hydrogen peroxide. An optimized foam was then treated with colloidal Ag solution to explore its potential use in disinfecting water for 10 weeks. The modified foam demonstrated a significant reduction (2.84 log10 units) in E. coli bacteria compared to an unmodified filter (1.57 log10 units). Additionally, the environmental impact of the porous AAM was analyzed through life cycle assessment and found to be lower than that of conventional ceramic filter.
Finally, to develop material capable of separating microplastics, porous AAM surface was modified with triethoxy(octyl)silane to render it superhydrophobic. The modified porous AAM demonstrated over 99% separation efficiency when treating 30 L of model water containing 5 mg/L of polyethylene microspheres (53-63 μm). Its performance was also evaluated in treating laundry effluent, where the modified porous AAM achieved approximately 84% separation compared to around 52% for the unmodified porous AAM.Abstrakti
Alkaliaktivoiduilla materiaaleilla on runsaasti erilaisia sovelluksia veden ja jäteveden käsittelyssä. Tässä väitöskirjassa valmistettiin huokoisia alkaliaktivoituja vaahtoja tavoitteena selvittää niiden uusia hyödyntämismahdollisuuksia adsorboivina suodatinmateriaaleina, veden desinfioinnissa ja mikromuovin erottamisessa.
Masuunikuonasta valmistettujen adsorboivien suodattimien koostumus optimoitiin muuttamalla valmistuksessa käytetyn pinta-aktiivisen aineen tyyppiä sekä vaahdotinaineena toimivan vetyperoksidin lisäysmäärää. Optimoidulla materiaalilla tutkittiin metyleenisinisen adsorptiota vedestä. Adsorptiokyvyn lisäämiseksi valmistettiin ligniiniä sisältävää komposiittimateriaalia. Dynaamisessa metyleenisinisen adsorptiokokeessa suurin adsorptiomäärä ligniinikomposiitille oli ~40 mg/g. Lisäksi peretikkahappoa tutkittiin vaihtoehtoisena vaahdotusaineena. Peretikkahappoa käytettäessä havaittiin pienempi turpoaminen valmistuksen aikana ja lyhyempi kovettumisaika verrattuna vetyperoksidilla valmistettuihin vaahtoihin.
Tutkimuksen seuraavassa osassa tutkittiin veden desinfiointia. Alkaliaktivoituja vaahtoja valmistettiin metakaoliinista, masuunikuonasta ja niiden seoksista tavoitteena saavuttaa samanlainen veden läpäisevyys kuin keraamisilla suodattimilla. Tämän jälkeen optimoitua vaahtoa käsiteltiin kolloidisella hopealiuoksella ja sen käyttömahdollisuuksia veden desinfioinnissa tutkittiin 10 viikon ajan. Hopeaa sisältävä vaahto osoitti merkittävää E. coli -bakteerien vähenemistä (2,84 log10) verrattuna hopeaa sisältämättömään suodattimeen (1,57 log10). Lisäksi alkaliaktivoidun vaahdon ympäristövaikutuksia analysoitiin elinkaariarvioinnin avulla ja niiden todettiin olevan pienempiä kuin perinteisen keraamin.
Mikromuovien erottamiseksi alkaliaktivoituja vaahtoja käsiteltiin trietoksi(oktyyli)silaanilla superhydrofobisen pinnan luomiseksi. Käsitelty vaahto poisti yli 99 % mikromuovista kokeessa, jossa käsiteltiin 30 litraa vettä, joka sisälsi 5 mg/l polyetyleenipartikkeleita (koko 53–63 μm). Käsitellyn vaahdon suorituskykyä arvioitiin myös pyykinpesuveden käsittelyssä, jossa sen muovin poistokyky oli noin 84 % kun taas ei-käsitelty vaahto poisti vain 52 %
Negotiating Citizenship on the Frontlines: How the Devolution of Canadian Immigration Policy Shapes Service Delivery to Women Fleeing Abuse
No full textAuthor Posting. © Bhuyan 2012. This is the author's version of the work. It is posted here for personal use, not for redistribution. The definitive version was published in Law & Policy, 34(2): 211-236. http://dx.doi.org/ 10.1111/j.1467-9930.2011.00361.xFrom publisher: This article examines how nongovernmental service providers navigate devolutionary trends in Canada, in both immigration control and integration policy, when responding to migrants who come to them for help and support. Drawing upon conceptualizations of citizenship as a “negotiated relationship” (Stasiulis and Bakan 2003), I explore how social service providers, who work amidst a complex interplay of federal, provincial, and local policies, can influence both who is deemed worthy of social membership and what rights an individual can successfully claim from the state. Empirically, this article focuses on observation of community meetings and conversational interviews with service providers in violence against women shelters in Toronto, Ontario, Canada's most populous and diverse city. While service providers navigate different levels of government to advocate for women's rights to seek safety from abuse, I argue that both individual service providers and the organizations in which they work monitor and constrain the degree to which they openly challenge state authority to restrict immigrants' “right to have rights” (Arendt 1951 [1979], 296).This work was generously supported by CERIS—The Ontario Metropolis Centre
Si and Ge based metallic core/shell nanowires for nano-electronic device applications
No full textOne dimensional heterostructure nanowires (NWs) have attracted a large attention due to the possibility of easily tuning their energy gap, a useful property for application to next generation electronic devices. In this work, we propose new core/shell NW systems where Ge and Si shells are built around very thin As and Sb cores. The modification in the electronic properties arises due to the induced compressive strain experienced by the metal core region which is attributed to the lattice-mismatch with the shell region. As/Ge and As/Si nanowires undergo a semiconducting-to-metal transition on increasing the diameter of the shell. The current-voltage (I-V) characteristics of the nanowires show a negative differential conductance (NDC) effect for small diameters that could lead to their application in atomic scale device(s) for fast switching. In addition, an ohmic behavior and upto 300% increment of the current value is achieved on just doubling the shell region. The resistivity of nanowires decreases with the increase in diameter. These characteristics make these NWs suitable candidates for application as electron connectors in nanoelectronic devices
Enhanced thermoelectric properties in Sb/Ge core/shell nanowires through vacancy modulation
No full textIn the present work, we have modified the physical and electronic structure of Sb/Ge core/shell nanowires via vacancy creation and doping with foreign atoms with the aim to improve their thermoelectric energy conversion efficiency. Sb/Ge-NWs having a diameter of 1.5 Å show metallicity with 2Go quantum conductance. The stability of the nanowires is assessed through the calculation of their formation energy. The formation of one vacancy at either the Sb- and Ge-site modifies substantially the electronic properties. From the comparison of the thermoelectric properties of the nanowires with and without the vacancy, we have found that the figure of merit for the Sb/Ge NW with one Sb vacancy increases of 0.18 compared to the pristine NW. The NW doping with different transition metals: Fe, Co, Ni and Cu have been found to also enhance the conversion efficiency. Thus, our calculations show that the thermoelectric performance of metal–semiconductor core–shell NWs can be in principle improved as much as 80% by vacancy formation and doping
Charge Transfer Initiated Copolymerization of Styrene and Maleic Anhydride by N-Butylamine
No full textJ. N. College, Pasighat, Arunachal Pradesh-791 103
Department of Chemistry, Dibrugarh University, Dibrugarh-786 004
Manuscript received 22 December 1988, revised 27 November 1989, accepted, 7 May 1990
Copolymers of styrene and maleic anhydride with varying feed ratios have been synthesised by a charge transfer initiated mechanism using a mixture of n-butylamine and carbon tetrachloride in dimethyl sulphoxide at 60o. Reactivity ratios are calculated by Finemann-Ross and Kelen-Tudos methods. The copolymers are chraracterised by ir and 13C nmr spectroscopy. The copolymers are mostly alternating and are hygroscopic. Thermal stabilities are checked by thermogravimetric analysis. Thermal degradations of the copolymers is a two-stage process, the major degradation being the first stage. The copolymers decompose at a lower temperature than polystyren
Calculation of Electric and Magnetic Field under AC Transmission and Distribution Lines in Guwahati City
No full textWith the increasing population rate and industrial growth rate, the demand for power has escalated significantly. High Voltage AC transmission can be termed as one of the measures to quench this increasing energy demands. This paper evaluates the safety limits for electric and magnetic fields generated around the AC transmission and distribution lines at various voltage levels and configuration. Surface current density for an average height human being has also been calculated for safety precautions.Keywords: Safety limits, electric field, magnetic field, surface current density*Cite as: Manash Jyoti Baishya, Satyajit Bhuyan, N.K.Kishore, “Calculation of Electric and Magnetic Field under AC Transmission and Distribution Lines in Guwahati City†ADBU J.Engg.Tech., 1(2014) 0011406(5pp
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