27 research outputs found
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Tomorrow's College: The Future of Higher Education
No full textJeffrey Selingo, an author, reporter, and editor at large of The Chronicle of Higher Education, presented a talk on the future of higher education at Columbia University. Sree Sreenivasan, Columbia's Chief Digital Officer, introduced the talk
A controlled crossover study to assess the role of dietary eliminations in reducing the severity of atopic dermatitis in children
No full textBackground: In the pathogenesis of atopic dermatitis (AD), immune sensitization to food-derived allergens has a role. However, the evidence of allergen sensitization is not a proof of clinically relevant allergy and it has to be confirmed by food challenges so that unnecessary food restrictions in growing children can be avoided. Aims and Objectives: This study was conducted to assess the clinical severity of AD in children after certain dietary modifications and to correlate absolute eosinophil count (AEC) with dietary modification. Materials and Methods: A total of thirty AD children were enrolled randomly into a trial period of egg and cow's milk exclusion diet or control period of egg and cow's milk inclusion diet of 3 weeks. At the end of 3 weeks, patients resumed their normal diet to minimize any carryover effect for next 3 weeks. In the last 3 weeks, the trial and the control groups were crossed over. Patients were assessed at baseline and at the end of each 3-week period using SCORing AD (SCORAD) index and AEC. The data were analyzed using paired t-test. Results: The mean SCORAD at the end of control and trial period was 18.3 and 14.3, respectively, with a mean difference of 3.4, which is statistically not significant (P = 0.165). The mean AEC at the end of control and trial period was 836.5 and 799.6, respectively, the reduction being statistically not significant. Conclusion: Our study could not confirm the beneficial effects of an allergen avoidance diet in AD. We propose that dietary elimination advices should be given only to patients with a definite history of food-induced exacerbations of the disease
Mg-rikas alumiinisilikaattien synteesi ja alkalin aktivointi
No full textAbstractAlkali-activated materials (AAMs) are alternative cementitious materials with lower carbon footprints compared to traditional Portland cement (PC). In addition to Ca, Si, and Al, the precursors used in the preparation of AAMs can sometimes include considerable amounts of Mg, so that Mg significantly influences the structure and properties of AAMs. When compared to Ca, Si, and Al, relatively few studies have focused on the role of Mg in AAMs. This thesis deals with alkali activation of Mg-rich aluminosilicate precursors with the following objectives: 1) preparation, characterization, and estimation of alkaline reactivity of Na-Mg aluminosilicate glasses; 2) synthesis of AAMs from Na-Mg aluminosilicate glasses and their detailed characterization to understand the fate of Mg; and 3) estimation of the potential of phlogopite as a Mg-rich raw material for alkali activation.The structural study of Na-Mg aluminosilicate glasses indicates that the higher cationic field strength (CFS) of Mg than Na makes Mg preferable as a network modifier, whereas Na acts as a charge compensator. Alkaline reactivity studies of Na-Mg aluminosilicate glasses reveal that as Mg replaces Na in glasses, the reactivity of the glasses increases initially, attains a maximum, and then drops. This trend can be explained by the interplay between glass depolymerization and optical basicity: depolymerization dictates the glass reactivity initially, while the effect of optical basicity dominates at later stages. Detailed structural study of AAMs prepared from Na-Mg aluminosilicate glasses indicates that Mg in AAMs exists as an amorphous magnesium silicate (AMS) phase, but the existence of this phase is not well documented in the literature. The driving force for AMS formation is the high CFS of Mg, which leads to effective stabilization of the depolymerized silicate species. The absence of hydrotalcite-group phases from these AAMs is due to the depletion of Al by zeolite production. The assessment of phlogopite mineral as a Mg-rich precursor for alkali activation indicates that untreated phlogopite is highly inert. However, thermal treatment could enhance the alkaline reactivity of phlogopite.Original papersOriginal papers are not included in the electronic version of the dissertation.Sreenivasan, H., Kinnunen, P., Adesanya, E., Patanen, M., Kantola, A. M., Telkki, V.-V., Huttula, M., Cao, W., Provis, J. L., & Illikainen, M. (2020). Field Strength of Network-Modifying Cation Dictates the Structure of (Na-Mg) Aluminosilicate Glasses. Frontiers in Materials, 7. https://doi.org/10.3389/fmats.2020.00267Self-archived versionSreenivasan, H., Cao, W., Hu, Y., Xiao, Q., Shakouri, M., Huttula, M., Provis, J. L., Illikainen, M., & Kinnunen, P. (2020). Towards designing reactive glasses for alkali activation: Understanding the origins of alkaline reactivity of Na-Mg aluminosilicate glasses. PLOS ONE, 15(12), e0244621. https://doi.org/10.1371/journal.pone.0244621Self-archived versionSreenivasan, H., Adesanya, E., Niu, H., Perumal, P., Kantola, A. M., Telkki, V.-V., Huttula, M., Cao, W., Provis, J. L., Illikainen, M., & Kinnunen, P. (2021). Evidence of formation of an amorphous magnesium silicate (AMS) phase during alkali activation of (Na-Mg) aluminosilicate glasses. Cement and Concrete Research, 145, 106464. https://doi.org/10.1016/j.cemconres.2021.106464Self-archived versionSreenivasan, H., Kinnunen, P., Heikkinen, E.-P., & Illikainen, M. (2017). Thermally treated phlogopite as magnesium-rich precursor for alkali activation purpose. Minerals Engineering, 113, 47–54. https://doi.org/10.1016/j.mineng.2017.08.003TiivistelmäAlkali -aktivoidut materiaalit (AAM) ovat vaihtoehtoisia sementtimateriaaleja, joilla on pienempi hiilijalanjälki verrattuna perinteiseen portland -sementtiin (PC). Ca: n, Si: n ja Al: n lisäksi esiasteissa (joita käytetään AAM: ien valmistukseen) voi joskus olla huomattava määrä Mg: tä, ja tämä johtaa siihen, että Mg vaikuttaa merkittävästi AAM: ien rakenteeseen ja ominaisuuksiin. Verrattuna Ca, Si ja Al, on ollut suhteellisen vähän tutkimuksia, joissa keskitytään Mg: n rooliin AAM: issä. Tämä opinnäytetyö käsittelee Mg-rikkaiden alumiinisilikaattiesiasteiden alkaliaktivaatiota seuraavilla tavoitteilla: 1) Na-Mg-alumiinisilikaattilasien alkalisen reaktiivisuuden valmistelu, karakterisointi ja arviointi; 2) synteesi AAM: istä Na-Mg-alumiinisilikaattilasista ja niiden yksityiskohtainen karakterisointi Mg: n kohtalon ymmärtämiseksi; 3) Flogopiitin potentiaalin arviointi Mg-rikkaana raaka-aineena alkalin aktivoimiseksi.Na-Mg-alumiinisilikaattilasien rakennetutkimus osoittaa, että Mg: n korkeamman kationisen kentänvoimakkuuden (CFS) takia Na: n vuoksi Mg on edullinen verkon muokkaajana, kun taas Na toimii varauksen kompensoijana. Na-Mg-alumiinisilikaattilasien alkaliset reaktiivisuustutkimukset paljastavat, että kun Mg korvaa Na: n lasissa, lasien reaktiivisuus kasvaa aluksi ja saavuttaa maksimin, minkä jälkeen se laskee. Tämä suuntaus voidaan selittää lasin depolymeroinnin ja optisen emäksisyyden välisellä vuorovaikutuksella: depolymerointi sanelee aluksi lasin reaktiivisuuden, kun taas optisen emäksisyyden vaikutus hallitsee myöhemmässä vaiheessa. Yksityiskohtainen rakenteellinen tutkimus AAM: ista, jotka on valmistettu Na-Mg-alumiinisilikaattilasista, osoittaa, että Mg AAM-yhdisteissä esiintyy amorfisena magnesiumsilikaatti (AMS) -faasina, jonka olemassaoloa ei ole hyvin dokumentoitu kirjallisuudessa. AMS: n muodostumisen liikkeellepaneva voima on Mg: n korkea CFS, mikä johtaa depolymeroitujen silikaattilajien tehokkaaseen vakautumiseen. Hydrotaltsiittiryhmän faasien puuttuminen näistä AAM: ista on havaittu johtuvan Al: n ehtymisestä zeoliittituotannolla. Flogopiittimineraalin arviointi Mg-rikkaana esiasteena alkalin aktivoitumiselle osoittaa, että käsittelemätön flogopiitti on erittäin inertti. Lämpökäsittely voi kuitenkin parantaa flogopiitin emäksistä reaktiivisuutta.OsajulkaisutOsajulkaisut eivät sisälly väitöskirjan elektroniseen versioon.Sreenivasan, H., Kinnunen, P., Adesanya, E., Patanen, M., Kantola, A. M., Telkki, V.-V., Huttula, M., Cao, W., Provis, J. L., & Illikainen, M. (2020). Field Strength of Network-Modifying Cation Dictates the Structure of (Na-Mg) Aluminosilicate Glasses. Frontiers in Materials, 7. https://doi.org/10.3389/fmats.2020.00267Rinnakkaistallennettu versioSreenivasan, H., Cao, W., Hu, Y., Xiao, Q., Shakouri, M., Huttula, M., Provis, J. L., Illikainen, M., & Kinnunen, P. (2020). Towards designing reactive glasses for alkali activation: Understanding the origins of alkaline reactivity of Na-Mg aluminosilicate glasses. PLOS ONE, 15(12), e0244621. https://doi.org/10.1371/journal.pone.0244621Rinnakkaistallennettu versioSreenivasan, H., Adesanya, E., Niu, H., Perumal, P., Kantola, A. M., Telkki, V.-V., Huttula, M., Cao, W., Provis, J. L., Illikainen, M., & Kinnunen, P. (2021). Evidence of formation of an amorphous magnesium silicate (AMS) phase during alkali activation of (Na-Mg) aluminosilicate glasses. Cement and Concrete Research, 145, 106464. https://doi.org/10.1016/j.cemconres.2021.106464Rinnakkaistallennettu versioSreenivasan, H., Kinnunen, P., Heikkinen, E.-P., & Illikainen, M. (2017). Thermally treated phlogopite as magnesium-rich precursor for alkali activation purpose. Minerals Engineering, 113, 47–54. https://doi.org/10.1016/j.mineng.2017.08.003Academic dissertation to be presented with the assent of the Doctoral Training Committee of Technology and Natural Sciences of the University of Oulu for public defence in the OP-Pohjola auditorium (L6), Linnanmaa, on 8 October 2021, at 12 noonAbstract
Alkali-activated materials (AAMs) are alternative cementitious materials with lower carbon footprints compared to traditional Portland cement (PC). In addition to Ca, Si, and Al, the precursors used in the preparation of AAMs can sometimes include considerable amounts of Mg, so that Mg significantly influences the structure and properties of AAMs. When compared to Ca, Si, and Al, relatively few studies have focused on the role of Mg in AAMs. This thesis deals with alkali activation of Mg-rich aluminosilicate precursors with the following objectives: 1) preparation, characterization, and estimation of alkaline reactivity of Na-Mg aluminosilicate glasses; 2) synthesis of AAMs from Na-Mg aluminosilicate glasses and their detailed characterization to understand the fate of Mg; and 3) estimation of the potential of phlogopite as a Mg-rich raw material for alkali activation.
The structural study of Na-Mg aluminosilicate glasses indicates that the higher cationic field strength (CFS) of Mg than Na makes Mg preferable as a network modifier, whereas Na acts as a charge compensator. Alkaline reactivity studies of Na-Mg aluminosilicate glasses reveal that as Mg replaces Na in glasses, the reactivity of the glasses increases initially, attains a maximum, and then drops. This trend can be explained by the interplay between glass depolymerization and optical basicity: depolymerization dictates the glass reactivity initially, while the effect of optical basicity dominates at later stages. Detailed structural study of AAMs prepared from Na-Mg aluminosilicate glasses indicates that Mg in AAMs exists as an amorphous magnesium silicate (AMS) phase, but the existence of this phase is not well documented in the literature. The driving force for AMS formation is the high CFS of Mg, which leads to effective stabilization of the depolymerized silicate species. The absence of hydrotalcite-group phases from these AAMs is due to the depletion of Al by zeolite production. The assessment of phlogopite mineral as a Mg-rich precursor for alkali activation indicates that untreated phlogopite is highly inert. However, thermal treatment could enhance the alkaline reactivity of phlogopite.Tiivistelmä
Alkali -aktivoidut materiaalit (AAM) ovat vaihtoehtoisia sementtimateriaaleja, joilla on pienempi hiilijalanjälki verrattuna perinteiseen portland -sementtiin (PC). Ca: n, Si: n ja Al: n lisäksi esiasteissa (joita käytetään AAM: ien valmistukseen) voi joskus olla huomattava määrä Mg: tä, ja tämä johtaa siihen, että Mg vaikuttaa merkittävästi AAM: ien rakenteeseen ja ominaisuuksiin. Verrattuna Ca, Si ja Al, on ollut suhteellisen vähän tutkimuksia, joissa keskitytään Mg: n rooliin AAM: issä. Tämä opinnäytetyö käsittelee Mg-rikkaiden alumiinisilikaattiesiasteiden alkaliaktivaatiota seuraavilla tavoitteilla: 1) Na-Mg-alumiinisilikaattilasien alkalisen reaktiivisuuden valmistelu, karakterisointi ja arviointi; 2) synteesi AAM: istä Na-Mg-alumiinisilikaattilasista ja niiden yksityiskohtainen karakterisointi Mg: n kohtalon ymmärtämiseksi; 3) Flogopiitin potentiaalin arviointi Mg-rikkaana raaka-aineena alkalin aktivoimiseksi.
Na-Mg-alumiinisilikaattilasien rakennetutkimus osoittaa, että Mg: n korkeamman kationisen kentänvoimakkuuden (CFS) takia Na: n vuoksi Mg on edullinen verkon muokkaajana, kun taas Na toimii varauksen kompensoijana. Na-Mg-alumiinisilikaattilasien alkaliset reaktiivisuustutkimukset paljastavat, että kun Mg korvaa Na: n lasissa, lasien reaktiivisuus kasvaa aluksi ja saavuttaa maksimin, minkä jälkeen se laskee. Tämä suuntaus voidaan selittää lasin depolymeroinnin ja optisen emäksisyyden välisellä vuorovaikutuksella: depolymerointi sanelee aluksi lasin reaktiivisuuden, kun taas optisen emäksisyyden vaikutus hallitsee myöhemmässä vaiheessa. Yksityiskohtainen rakenteellinen tutkimus AAM: ista, jotka on valmistettu Na-Mg-alumiinisilikaattilasista, osoittaa, että Mg AAM-yhdisteissä esiintyy amorfisena magnesiumsilikaatti (AMS) -faasina, jonka olemassaoloa ei ole hyvin dokumentoitu kirjallisuudessa. AMS: n muodostumisen liikkeellepaneva voima on Mg: n korkea CFS, mikä johtaa depolymeroitujen silikaattilajien tehokkaaseen vakautumiseen. Hydrotaltsiittiryhmän faasien puuttuminen näistä AAM: ista on havaittu johtuvan Al: n ehtymisestä zeoliittituotannolla. Flogopiittimineraalin arviointi Mg-rikkaana esiasteena alkalin aktivoitumiselle osoittaa, että käsittelemätön flogopiitti on erittäin inertti. Lämpökäsittely voi kuitenkin parantaa flogopiitin emäksistä reaktiivisuutta
The investigation of phase synchronization in the cortex during a fatiguing muscle contraction using EEG
No full textIncludes bibliographical references (leaves 140-157)
Application of a Cleavage Fracture Stress Model for Estimating the ASTM E-1921 Reference Temperature of Ferritic Steels from Instrumented Impact Test of CVN Specimens without Precracking
No full textAbstractA recently proposed semi-empirical cleavage fracture stress (CFS) model by the author based on the microscopic cleavage fracture stress, σf, for estimating the ASTM E-1921 reference temperature, T0, of ferritic steels from instrumented impact test (IIT) of Charpy V-notch (CVN) specimens without precracking has been demonstrated for steels with room temperature yield strength in the range 400-750MPa, including irradiated steels. The estimate of T0, based on the CFS model, TQcfs lies within a ± 20°C band, being conservative for most of the steels, but less conservative than TQIGC based on the IGC-procedure. CFS model enhances the validity and utility of the CVN IIT by enabling estimation of design-relevant master curve from unprecracked CVN specimens. In this paper, the method is further applied to some steels (both unirradiated and irradiated) reported in the literature most of which have only IIT data and static tensile data available. The method has also been applied to some IIT test results obtained at IGCAR for 9Cr-1Mo steel in various simulated weld-heat affected zone conditions. The results are compared with TQIGC or other estimates like TQBT or T0, if available
Aloe vera in active and passive regions of electronic devices towards a sustainable development
No full textIdentifying the Income-Poor: Some Controversies in India and Elsewhere
No full textConventional approaches to the measurement of income-poverty require the ability to identify the poor by reference to a specified poverty line. On the face of it, it may appear to be unproblematic to specify such a poverty line. There are, however, analytical and conceptual difficulties entailed in the identification exercise of poverty measurement, and many of these difficulties have to do with the determination of the appropriate space in which to seek invariance of the poverty standard in terms of which poverty comparisons can be effected. These conceptual niggles have been a feature of the actual experience of the evolution of money-metric poverty lines in concrete historical settings. This essay reviews and critically interprets the Indian experience of poverty estimation with specific reference to the identification problem as it has been addressed in the country in the last fifty or so years. The essay also briefly engages with aspects of the record, in this regard, of the United States Federal Government's poverty thresholds and the World Bank's international poverty lines. An attempt is made to locate the analytical basis of the conceptual difficulties informing the identification exercise, and to relate this to the confusions and controversies that have attended many of the actual efforts in India and elsewhere to assess the magnitudes, spatial distribution, and temporal trends of money-metric poverty. Finally, the essay also advances an alternative practical proposal for the measurement of poverty which avoids the identification exercise altogether, and incorporates within itself aspects of the notions of both relative inequality and inclusive growth. This approach is certainly not exempt from conceptual difficulties of its own. It is, nevertheless, worth asking if the directness and simplicity of this alternative prescription, combined with the conceptual and practical difficulties which also inform the conventional approach to the identification problem, may constitute grounds for submitting the proposal to at least a preliminary consideration. It remains to add that this essay draws very heavily on earlier work done by the author on its subject of enquiry
Study of clinical spectrum of pediatric dermatoses in patients attending a Tertiary Care Center in North Kerala
No full textIntroduction: Skin diseases are a major health problem in the pediatric age group.
Aim: To determine the prevalence and clinical characteristics of different pediatric dermatoses in a tertiary care centre in Kerala.
Materials and Methods: Children with age 18 years and below with clinical evidence of cutaneous disorders were studied.
Results: 500 cases were studied which showed a female preponderance of 51.4%. The most common dermatoses was infections and infestations (33.8%) followed by eczemas (32.6%), disorders of sweat and sebaceous glands (7.4%), keratinisation and paulosquamous disorders (4%). Nutritional disorders were seen in 1% of children. 3.6% had photodermatoses, 2.6% had hair and nail disorders and 0.4 % had adverse cutaneous drug reactions.
Conclusions: Fungal infection was the most common infection noted in the study, followed by viral and bacterial infection. Allergic contact dermatitis was the commonest exogenous eczema and juvenile plantar dermatosis was the commonest endogenous eczemas. Acne, insect bite reaction and miliaria were the other common dermatoses
Identifying the Income-Poor: Some Controversies in India and Elsewhere
No full textConventional approaches to the measurement of income-poverty require the ability to identify the poor by reference to a specified poverty line. On the face of it, it may appear to be unproblematic to specify such a poverty line. There are, however, analytical and conceptual difficulties entailed in the identification exercise of poverty measurement, and many of these difficulties have to do with the determination of the appropriate space in which to seek invariance of the poverty standard in terms of which poverty comparisons can be effected. These conceptual niggles have been a feature of the actual experience of the evolution of money-metric poverty lines in concrete historical settings. This essay reviews and critically interprets the Indian experience of poverty estimation with specific reference to the identification problem as it has been addressed in the country in the last fifty or so years. The essay also briefly engages with aspects of the record, in this regard, of the United States Federal Government’s poverty thresholds and the World Bank’s international poverty lines. An attempt is made to locate the analytical basis of the conceptual difficulties informing the identification exercise, and to relate this to the confusions and controversies that have attended many of the actual efforts in India and elsewhere to assess the magnitudes, spatial distribution, and temporal trends of money-metric poverty. Finally, the essay also advances an alternative practical proposal for the measurement of poverty which avoids the identification exercise altogether, and incorporates within itself aspects of the notions of both relative inequality and inclusive growth. This approach is certainly not exempt from conceptual difficulties of its own. It is, nevertheless, worth asking if the directness and simplicity of this alternative prescription, combined with the conceptual and practical difficulties which also inform the conventional approach to the identification problem, may constitute grounds for submitting the proposal to at least a preliminary consideration. It remains to add that this essay draws very heavily on earlier work done by the author on its subject of enquiry.money-metric poverty line; resources; capabilities; evolution of Indian poverty line; US poverty thresholds; the World Bank poverty line; alternative approach to measuring poverty; quintile income
