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1.
Explore (NY) ; 20(6): 103042, 2024 Aug 20.
Artículo en Inglés | MEDLINE | ID: mdl-39182272

RESUMEN

Indigenous communities across Canada persist at the forefront of environmental and climate-related challenges, necessitating a concerted effort to integrate traditional Indigenous land-based knowledge and practices that inherently promote environmental protection and resilience. Using a decolonial feminist theoretical framework, this research centers on Indigenous community perspectives on the climate crisis and their land-based adaptions. Such an approach empowers Indigenous communities to reclaim agency over their narratives and shape research agendas congruent with their lived realities and aspirations. The study concludes by promoting the imperative of revitalizing traditional Indigenous land-based knowledge, practices and relationships with their ancestral lands. Despite emerging recognition within the scientific literature and international agreements, such as the Paris Agreement, of the significance of traditional Indigenous land-based knowledge, many climate mitigation and adaptation initiatives continue to overlook Indigenous participation at various decision-making junctures. Hence, this paper advocates the necessity for international frameworks to acknowledge and integrate traditional knowledge systems and Indigenous participation across national borders, fostering inclusive climate crisis solutions that resonate with Indigenous communities' perspectives and experiences.

2.
BMJ Open ; 14(8): e077113, 2024 Aug 21.
Artículo en Inglés | MEDLINE | ID: mdl-39174066

RESUMEN

INTRODUCTION: The intersection of sexism with racism and xenophobia disproportionately exposes visible minority women to gender-based violence (GBV) at the community and systemic levels. This study aims to understand the knowledge strengths and gaps on GBV against visible minority women with an intersectional lens, revealing systemic barriers to accessing support and how these barriers intensify GBV and its effects. It will also identify effective and ineffective policies and practices in the literature to develop strategies addressing the root causes of GBV and supporting survivors. METHODS AND ANALYSIS: We will conduct a mixed-methods systematic review using a convergent integrated approach to examine current literature on community- and systemic-level GBV against visible minority women. We will follow Joanna Briggs Institute's guidelines to converge data from both qualitative and quantitative studies to obtain an integrated qualitative synthesis on GBV in five countries: Canada, the USA, the UK, Australia and New Zealand. This analysis will be conducted following Thomas and Harden's thematic synthesis guidelines. Community members with lived experience of GBV will actively contribute to improving the relevance and interpretation of results, following a community-engaged research approach. Themes are expected to unveil various aspects of community- and systemic-level GBV due to the intersection of racism, xenophobia and sexism, alongside barriers in addressing GBV and research gaps. ETHICS AND DISSEMINATION: Since this study does not involve primary data collection or the use of identifiable human data, no ethical approval will be needed. Results will be disseminated through integrated knowledge translation, involving collaboration with participants who have lived experience of GBV. The findings will be used to identify specific areas of policy intervention, including adopting culturally sensitive approaches, improving school and workplace policies and promoting rights of visible minority women.


Asunto(s)
Violencia de Género , Revisiones Sistemáticas como Asunto , Humanos , Femenino , Grupos Minoritarios , Australia , Proyectos de Investigación , Nueva Zelanda , Canadá , Racismo/prevención & control , Sexismo , Estados Unidos , Reino Unido
3.
Camb Q Healthc Ethics ; : 1-11, 2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38567458

RESUMEN

Recent studies highlight the need for ethical and equitable digital health research that protects the rights and interests of racialized communities. We argue for practices in digital health that promote data self-determination for these communities, especially in data collection and management. We suggest that researchers partner with racialized communities to curate data that reflects their wellness understandings and health priorities, and respects their consent over data use for policy and other outcomes. These data governance approach honors and builds on Indigenous Data Sovereignty (IDS) decolonial scholarship by Indigenous and non-indigenous researchers and its adaptations to health research involving racialized communities from former European colonies in the global South. We discuss strategies to practice equity, diversity, inclusion, accessibility and decolonization (EDIAD) principles in digital health. We draw upon and adapt the concept of Precision Health Equity (PHE) to emphasize models of data sharing that are co-defined by racialized communities and researchers, and stress their shared governance and stewardship of data that is generated from digital health research. This paper contributes to an emerging research on equity issues in digital health and reducing health, institutional, and technological disparities. It also promotes the self-determination of racialized peoples through ethical data management.

4.
Explore (NY) ; 20(5): 102998, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38609742

RESUMEN

The continuous process of settler colonialism in Canada has profoundly impacted Indigenous Peoples' relationship with the Land and water, which holds immense significance in their healing journey. Reconnecting with the land and water through culturally rooted practices has far-reaching implications for the health and well-being of Indigenous communities. Maintaining a strong bond with the land and water is integral to Indigenous healing traditions. To gain insights into this connection we used a relational theoretical framework and engaged with Ministikwan Lake Cree Nation, a remote Indigenous community. Our approach centred around community-based participatory research, utilizing methods like deep listening, cultural camps and story-sharing to collect wisdom from community members, knowledge keepers, and Elders. The research findings show understanding the connection between Land-based healing practices and Indigenous-led water governance is critical to solving the water crises within remote Indigenous communities. This knowledge is indispensable for reshaping current water governance systems and ensuring the well-being of Indigenous communities across Canada.


Asunto(s)
Colonialismo , Abastecimiento de Agua , Humanos , Canadá , Investigación Participativa Basada en la Comunidad , Pueblos Indígenas/psicología , Indígenas Norteamericanos
5.
Explore (NY) ; 20(5): 102985, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38403549

RESUMEN

This paper represents Youth's involvement in land-based learning in Indigenous culture camps (LLICP) in a powerful and innovative approach to addressing the pressing global issue of climate change. Following Indigenist and relational approaches, we (Indigenous and non-Indigenous youth and educators) explore the critical aspects of this initiative, highlighting its significance and potential impact. Indigenous communities have long held a deep connection with the land and possess traditional knowledge that is invaluable in combating climate change. The LLICP initiative involves organizing cultural camps designed for youth from diverse backgrounds to learn from Indigenous elders and community leaders about the vital relationship between the environment and Indigenous cultures. The LLICP provides a unique opportunity for young people to engage with Indigenous wisdom, traditional practices, and land-based teachings. Through Indigenous elders and knowledge-keepers guidelines, we learned a holistic understanding of sustainable living, biodiversity conservation, and the importance of preserving ecosystems. Our learning helped us, particularly our youths, to become proactive stewards of the environment and advocates for climate action. The LLICP fosters cross-cultural understanding and collaboration, encouraging a sense of unity among youths. The LLICP inspires innovative solutions to climate-related challenges and empowers youth to take leadership roles in their communities, advocating for sustainable policies and practices. The LLICP offers a powerful means of engaging young people in the fight against climate change while respecting and honoring Indigenous knowledge and heritage. It is a promising step towards a more sustainable and resilient future for all.


Asunto(s)
Cambio Climático , Conservación de los Recursos Naturales , Humanos , Saskatchewan , Adolescente , Aprendizaje , Pueblos Indígenas , Ecosistema , Cultura , Indígena Canadiense
6.
Adv Mater ; 36(6): e2307058, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38010977

RESUMEN

Achieving glass-like ultra-low thermal conductivity in crystalline solids with high electrical conductivity, a crucial requirement for high-performance thermoelectrics , continues to be a formidable challenge. A careful balance between electrical and thermal transport is essential for optimizing the thermoelectric performance. Despite this inherent trade-off, the experimental realization of an ideal thermoelectric material with a phonon-glass electron-crystal (PGEC) nature has rarely been achieved. Here, PGEC-like AgSbTe2 is demonstrated by tuning the atomic disorder upon Yb doping, which results in an outstanding thermoelectric performance with figure of merit, zT ≈ 2.4 at 573 K. Yb-doping-induced enhanced atomic ordering decreases the overlap between the hole and phonon mean free paths and consequently leads to a PGEC-like transport behavior in AgSbTe2 . A twofold increase in electrical mobility is observed while keeping the position of the Fermi level (EF ) nearly unchanged and corroborates the enhanced crystalline nature of the AgSbTe2 lattice upon Yb doping for electrical transport. The cation-ordered domains, lead to the formation of nanoscale superstructures (≈2 to 4 nm) that strongly scatter heat-carrying phonons, resulting in a temperature-independent glass-like thermal conductivity. The strategy paves the way for realizing high thermoelectric performance in various disordered crystals by making them amorphous to phonons while favoring crystal-like electrical transport.

7.
J Am Chem Soc ; 145(46): 25392-25400, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37942795

RESUMEN

Defect engineering, achieved by precise tuning of the atomic disorder within crystalline solids, forms a cornerstone of structural chemistry. This nuanced approach holds the potential to significantly augment thermoelectric performance by synergistically manipulating the interplay between the charge carrier and lattice dynamics. Here, the current study presents a distinctive investigation wherein the introduction of Hg doping into AgSbTe2 serves to partially curtail structural disorder. This strategic maneuver mitigates potential fluctuations originating from pronounced charge and size disparities between Ag+ and Sb3+, positioned in octahedral sites within the rock salt structure. Hg doping significantly improves the phase stability of AgSbTe2 by restricting the congenital emergence of the Ag2Te minor secondary phase and promotes partial atomic ordering in the cation sublattice. Reduction in atomic disorder coalesced with a complementary modification of electronic structure by Hg doping results in increased carrier mobility. The formation of nanoscale superstructure with sizes (2-5 nm) of the order of phonon mean free path in AgSbTe2 is further promoted by reduced partial disorder, causes enhanced scattering of heat-carrying phonons, and results in a glass-like ultralow lattice thermal conductivity (∼0.32 W m-1 K-1 at 297 K). Cumulatively, the multifaceted influence of Hg doping, in conjunction with the consequential reduction in disorder, allows achieving a high thermoelectric figure-of-merit, zT, of ∼2.4 at ∼570 K. This result defies conventional paradigms that prioritize increased disorder for optimizing zT.

8.
Adv Mater ; 34(40): e2203725, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-36028167

RESUMEN

Single crystals of SnSe have gained considerable attention in thermoelectrics due to their unprecedented thermoelectric performance. However, polycrystalline SnSe is more favorable for practical applications due to its facile chemical synthesis procedure, processability, and scalability. Though the thermoelectric figure of merit (zT) of p-type bulk SnSe polycrystals has reached >2.5, zT of n-type counterpart is still lower and lies around ≈1.5. Herein, record high zT of 2.0 in n-type polycrystalline SnSe0.92  + x mol% MoCl5 (x = 0-3) samples is reported, when measured parallel to the spark plasma sintering pressing direction due to the simultaneous optimization of n-type carrier concentration and enhanced phonon scattering by incorporating modular nano-heterostructures in SnSe matrix. Modular nanostructures of layered intergrowth [(SnSe)1.05 ]m (MoSe2 )n like compounds embedded in SnSe matrix scatters the phonons significantly leading to an ultra-low lattice thermal conductivity (κlat ) of ≈0.26 W m-1 K-1 at 798 K in SnSe0.92  + 3 mol% MoCl5 . The 2D layered modular intergrowth compound resembles the nano-heterostructure and their periodicity of 1.2-2.6 nm in the SnSe matrix matches the phonon mean free path of SnSe, thereby blocking the heat carrying phonons, which result in low κlat and ultra-high thermoelectric performance in n-type SnSe.

9.
J Phys Condens Matter ; 31(11): 115602, 2019 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-30625423

RESUMEN

We unveil the native defect induced high spin to low spin state transition in [Formula: see text] and half-metallicity in CoO. First principles calculations unravel that, defect density holds a key role in dictating the spin-state transition in [Formula: see text] ion in CoO, and introducing the half-metallicity. Charge transfer in the vicinity of vacancy plane favors the stabilization and coexistence of bivalent [Formula: see text] and trivalent [Formula: see text] ion in CoO. We propose that defect engineering could serve as a route to design the half metallicity in transition metal mono-oxides.

10.
Adv Mater ; 29(30)2017 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-28605066

RESUMEN

Spinel ferrite NiFe2 O4 thin films have been grown on three isostructural substrates, MgAl2 O4 , MgGa2 O4 , and CoGa2 O4 using pulsed laser deposition. These substrates have lattice mismatches of 3.1%, 0.8%, and 0.2%, respectively, with NiFe2 O4 . As expected, the films grown on MgAl2 O4 substrate show the presence of the antiphase boundary defects. However, no antiphase boundaries (APBs) are observed for films grown on near-lattice-matched substrates MgGa2 O4 and CoGa2 O4 . This demonstrates that by using isostructural and lattice-matched substrates, the formation of APBs can be avoided in NiFe2 O4 thin films. Consequently, static and dynamic magnetic properties comparable with the bulk can be realized. Initial results indicate similar improvements in film quality and magnetic properties due to the elimination of APBs in other members of the spinel ferrite family, such as Fe3 O4 and CoFe2 O4 , which have similar crystallographic structure and lattice constants as NiFe2 O4 .

11.
J Colloid Interface Sci ; 463: 99-106, 2016 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-26520816

RESUMEN

In a facile approach, Pd73Pt27 alloy nanowires (NWs) with large aspect ratios were synthesized in high yield by using sacrificial templates. Unlike majority of processes, our synthesis was carried out in aqueous solution with no intermittent separating stages for the products, while maintaining the NW morphology up to ∼30% of Pt. Upon evaporation of their dispersion, the NWs transform into a stable porous membrane due to self-entanglement and can be directly lifted and employed for electrocatalytic applications without external catalyst supports. We show that the NW membranes exhibit efficient electrocatalytic performance for methanol oxidation reaction (MOR) with 10 times higher mass activity and 4.4 times higher specific activity in acidic media as compared to commercial Pt catalysts. The membrane electrocatalysts is robust and exhibited very good stability with retention of ∼70% mass-activity after 4000 potential cycles. Since Pd was found to be inert towards MOR in acidic medium, our investigation provides a direct estimate of synergistic enhancement of efficiency. Over 10 times increment of mass activity appears to be significantly higher than previous investigations in various other reaction media.

12.
Adv Mater ; 27(30): 4430-4437, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26100079

RESUMEN

Robust, 26 nm thick free-standing platinum nanosheets, an extremely rare morphology for metal nanostructures, are obtained by employing fluid induced shearing force of the order of 1.8 N and differential shear-stress of 0.5 kPa across the diameter of a Te template nanorod undergoing galvanic displacement by Pt4+ . Corrugation leads to their large surface area and much improved electrocatalytic properties when compared with conventional Pt catalysts.

13.
ACS Appl Mater Interfaces ; 7(8): 4998-5005, 2015 Mar 04.
Artículo en Inglés | MEDLINE | ID: mdl-25660263

RESUMEN

Unlike other shapes, the design of tetrahedral Pt nanocrystals (Pt-NTd), which have the largest number of Pt(111) surface atoms and highest catalytic activities toward the electron transfer reactions, has widely been considered a synthetic challenge due to their thermodynamic instability. Here, we show that, by inducing their nucleation on functionalized carbon, Pt NTds can be obtained with tunable sizes and high yields. The carbon support anchors the nanocrystals early and prevents their oriented attachment leading to nanowire formation. Therein, an in situ generated amine is crucial for stabilization of Pt-NTds, which can later be removed to expose the Pt(111) facets for higher catalytic efficiency. The bare nanocrystals exhibit much improved stability and electrocatalytic activity characteristic of Pt(111) toward oxygen reduction reaction (ORR) and methanol and formic acid oxidation reactions. For example, ∼90% of their activity was retained after 5000 potential cycles, while the ORR onset potential was recorded to be very high, 1.01 V vs reversible hydrogen electrode (RHE).

14.
Angew Chem Int Ed Engl ; 52(49): 13057-61, 2013 Dec 02.
Artículo en Inglés | MEDLINE | ID: mdl-24218187

RESUMEN

Two sorts of MoS2 : A single-layer, metallic form of MoS2 (1T-MoS2 ) and a nanocomposite of a second form of MoS2 (few-layer 2H-MoS2 ) with heavily nitrogenated reduced graphene oxide (NRGO; N content ca. 15 %) show outstanding performance in the production of H2 under visible-light illumination.

15.
Dalton Trans ; 40(40): 10322-5, 2011 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-21776532

RESUMEN

Graphene analogues of MoSe(2) and WSe(2) have been prepared by three different chemical methods and characterized by electron microscopy and other methods. Graphene analogues of these diselenides as well as of GaSe have also been obtained by liquid-phase exfoliation. Raman spectra of the graphene analogues show significant changes relative to those of the bulk samples.

18.
ACS Nano ; 4(3): 1539-44, 2010 Mar 23.
Artículo en Inglés | MEDLINE | ID: mdl-20128601

RESUMEN

Enthused by the fascinating properties of graphene, we have prepared graphene analogues of BN by a chemical method with a control on the number of layers. The method involves the reaction of boric acid with urea, wherein the relative proportions of the two have been varied over a wide range. Synthesis with a high proportion of urea yields a product with a majority of 1-4 layers. The surface area of BN increases progressively with the decreasing number of layers, and the high surface area BN exhibits high CO(2) adsorption, but negligible H(2) adsorption. Few-layer BN has been solubilized by interaction with Lewis bases. We have used first-principles simulations to determine structure, phonon dispersion, and elastic properties of BN with planar honeycomb lattice-based n-layer forms. We find that the mechanical stability of BN with respect to out-of-plane deformation is quite different from that of graphene, as evident in the dispersion of their flexural modes. BN is softer than graphene and exhibits signatures of long-range ionic interactions in its optical phonons. Finally, structures with different stacking sequences of BN have comparable energies, suggesting relative abundance of slip faults, stacking faults, and structural inhomogeneities in multilayer BN.

19.
Chemistry ; 16(1): 149-57, 2010 Jan 04.
Artículo en Inglés | MEDLINE | ID: mdl-19946909

RESUMEN

A new analogue of graphene containing boron, carbon and nitrogen (BCN) has been obtained by the reaction of high-surface-area activated charcoal with a mixture of boric acid and urea at 900 degrees C. X-ray photoelectron spectroscopy and electron energy-loss spectroscopy reveal the composition to be close to BCN. The X-ray diffraction pattern, high-resolution electron microscopy images and Raman spectrum indicate the presence of graphite-type layers with low sheet-to-sheet registry. Atomic force microscopy reveals the sample to consist of two to three layers of BCN, as in a few-layer graphene. BCN exhibits more electrical resistivity than graphene, but weaker magnetic features. BCN exhibits a surface area of 2911 m(2) g(-1), which is the highest value known for a B(x)C(y)N(z) composition. It exhibits high propensity for adsorbing CO(2) ( approximately 100 wt %) at 195 K and a hydrogen uptake of 2.6 wt % at 77 K. A first-principles pseudopotential-based DFT study shows the stable structure to consist of BN(3) and NB(3) motifs. The calculations also suggest the strongest CO(2) adsorption to occur with a binding energy of 3.7 kJ mol(-1) compared with 2.0 kJ mol(-1) on graphene.

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