24 research outputs found

    Predictive simulation of non-steady-state transport of gases through rubbery polymer membranes

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    A multiscale, physically-based, reaction-diffusion kinetics model is developed for non-steady-state transport of simple gases through a rubbery polymer. Experimental data from the literature, new measurements of non-steady-state permeation and a molecular dynamics simulation of a gas-polymer sticking probability for a typical system are used to construct and validate the model framework. Using no adjustable parameters, the model successfully reproduces time-dependent experimental data for two distinct systems: (1) O_2 quenching of a phosphorescent dye embedded in poly(n-butyl(amino) thionylphosphazene), and (2) O_2, N_2, CH_4 and CO_2 transport through poly(dimethyl siloxane). The calculations show that in the pre-steady-state regime, permeation is only correctly described if the sorbed gas concentration in the polymer is dynamically determined by the rise in pressure. The framework is used to predict selectivity targets for two applications involving rubbery membranes: CO_2 capture from air and blocking of methane cross-over in an aged solar fuels device

    Challenges in implementing system thinking in agricultural sustainable intensification: A methodological note

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    System thinking is relevant to solve complex problems and deliver solutions for sustainable intensification of agricultural systems. Successful implementation of System Thinking in Sustainable Intensification of Agricultural Systems has faced conceptual hurdles that hinder its practical application. This methodological note addressed these challenges by emphasizing on the complexity and difficulty in conceptualizing STIBs and considering the absence of standardized approaches. These issues significantly impact the authentic integration of system thinking into agricultural systems. Key impediments include the identification of stakeholders and the determination of objective functions for STIBs implementation. Moreover, the spatial scale, spanning from the plot to the national level, poses a crucial consideration, as all issues across these scales contribute to effective system thinking. The temporal scale is equally important, encompassing events and phenomena over both short and extended periods. While efforts have been made to develop tools and approaches for guiding STIBs implementation within specific components or sectors, there is a notable gap in tools that facilitate a comprehensive system approach. Existing tools designed for this purpose are limited in their implementation and are not widely adopted. Alternatively, a critical approach involves selecting tools across scales and chaining them together to address these challenges. In this context, we designed an example of how tools at the plot, household (HH), landscape, and national scales can be strategically chained to tackle some of the aforementioned challenges, using Ethiopia as a case study. However, it is important to acknowledge the limitations associated with coupling and utilizing these processes effectively. By exploring the integration of tools across different scales and systematically chaining them, there is potential to overcome the current challenges in STIBs implementation. This methodological exploration aims to contribute to the development of a more holistic and widely applicable framework for successful system thinking in the context of sustainable agricultural intensification

    Predictive simulation of non-steady-state transport of gases through rubbery polymer membranes

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    A multiscale, physically-based, reaction-diffusion kinetics model is developed for non-steady-state transport of simple gases through a rubbery polymer. Experimental data from the literature, new measurements of non-steady-state permeation and a molecular dynamics simulation of a gas-polymer sticking probability for a typical system are used to construct and validate the model framework. Using no adjustable parameters, the model successfully reproduces time-dependent experimental data for two distinct systems: (1) O_2 quenching of a phosphorescent dye embedded in poly(n-butyl(amino) thionylphosphazene), and (2) O_2, N_2, CH_4 and CO_2 transport through poly(dimethyl siloxane). The calculations show that in the pre-steady-state regime, permeation is only correctly described if the sorbed gas concentration in the polymer is dynamically determined by the rise in pressure. The framework is used to predict selectivity targets for two applications involving rubbery membranes: CO_2 capture from air and blocking of methane cross-over in an aged solar fuels device

    Antenatal care utilization and nutrition counseling are strongly associated with infant and young child feeding knowledge among rural/semi-urban women in Harari region, Eastern Ethiopia

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    There is a gap in evidence linking antenatal care (ANC) utilization, nutrition counseling, and knowledge of pregnant women about infant and young child feeding (IYCF), particularly in low-income settings. Therefore, this study aimed to identify the association between ANC follow-up and nutrition counseling with IYCF knowledge. A cross-sectional study was conducted among 390 pregnant women in the rural kebeles of the Harari region from January to June 2019. Data were collected using face-to-face interviews on tablet computers. Bivariate and multivariate logistic regression were employed. An adjusted odds ratio (with 95% CI) was used to determine the strength of association between IYCF knowledge with ANC follow-up and nutrition counseling by adjusting for educational status, occupation, gravida, and distance to the nearest health center. Overall, 54.4% [95% CI 49.2, 59.2] of currently pregnant women were knowledgeable about IYCF of which only 20% started ANC follow-up and 24.4% received nutrition counseling. Out of 288 multigravida women, only 51.4% had ANC follow-up during their last pregnancy. In the adjusted model, ANC follow-up during the current pregnancy (AOR 1.85, 95% CI 1.07–3.22), those who received nutrition counseling (AOR 1.92, 95% CI 1.09–3.38), literate in education (AOR 1.71, 95% CI 1.07–2.73), multigravida (AOR 1.96, 95% CI 1.12–3.43), and far from the nearest health center (AOR 0.95, 95% CI 0.93–0.97) were significantly associated with the mothers IYCF knowledge. Thus, health care providers should encourage mothers to attend ANC during pregnancy and provide nutrition counseling about the IYCF

    Thermal Transitions in Perfluorosulfonated lonomer Thin-Films

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    The Protection of Traditional Knowledge under International Law: With Particular Emphasis to WIPO Draft Instrument for the Protection of TK

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    Traditional knowledge consists of is know-how, skills, innovations and practices that are passed on from generation to generation within indigenous peoples or local communities, forming part of its cultural identity and evolving. It contributes to the sustainable use and preservation of biodiversity, environmental and health care. Although the traditional knowledge s of indigenous people has been used to pursue different ends, the owners or holders of the knowledge are not getting benefits from their know-how, innovations, and skills. Currently, there is no international instrument that deals with the protection of traditional knowledge in a comprehensive and holistic manner. Under the auspices of WIPO the Intergovernmental Committee on Intellectual Property and Genetic Resources, Traditional Knowledge and Folklore (IGC) has prepared a draft text for an international regime for the protection of TK. The draft follows a sui generis approach for the protection of TK which combines a wide set of IP and non-IP tools and instruments. However, so far there has been more divergence than convergence on the need and scope of sui generis protection for TK in IGC meetings. Therefore, this thesis is devoted to the discussion on whether sui generis instrument for the protection of traditional knowledge is necessary. It also deals with the elements of effective sui generis instrument for the protection of traditional knowledg
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