7,302 research outputs found
Assessing Barriers and Opportunities for Ecosystem Based Approach to Adaptation in High Altitude City of Thimphu
Scientific studies to understand challenges and opportunities for adaptation are crucial for adapting to climate impacts and averting disasters in cities. In this study, we attempt to assess baseline social and environmental conditions, identify challenges and barriers, and recommend ecosystem based opportunities for adaptation. The cityās infrastructure is poorly planned triggering congestion (which leads to increased carbon emission, road rage, etc.), flooding of sewage systems exposing humans to infections. Majority of the poor who live in informal settlements lack adequate access to basic facilities turn to natural resources thereby depleting the environment around the city. This leads to the loss of ecosystem services and protection against natural hazards such as flash floods, landslides, and forest fires which affects the vulnerable groups disproportionately. To improve socio-ecological resilience to cope with changing climate, the study also identified ecosystem based adaptation interventions such as urban agriculture, agroforestry, greening projects, resettlement of informal settlements, education on coping strategies, and building institutional, technical, and individual capacities to be integrated into climate adaptation strategies into development plans. The study also recommended that the city authority secure adequate funds and build capacity to plan ecosystem based adaptation and implement interventions
Detection of volatile organic compounds (VOCs) using an optical fibre long period grating with a calixarene anchored mesoporous thin film
A long period grating (LPG) modified with a mesoporous film infused with a functional compound, calix[4]arene, was employed for the detection of volatile organic compounds (VOCs). The mesoporous film consisted of an inorganic part, of SiO2 nanoparticles (NPs) along with an organic moiety of poly(allylamine hydrochloride) polycation PAH, which was finally infused with functional compound, p-sulphanatocalix[4]arene (CA[4]). The LPG sensor was designed to operate at the phase matching turning point to provide the highest sensitivity. The sensing mechanism is based on the measurement of the refractive index (RI) change induced by the complexion of the VOCs with calix[4]arene (CA). The LPG modified with 5 cycles of (SiO2 NPs/PAH)5PAA responded to exposure to chloroform and benzene vapours. The sensitivity to humidity as an interfering parameter was also investigated
Polymer Acceptors with Flexible Spacers Afford Efficient and Mechanically Robust All-Polymer Solar Cells
High efficiency and mechanical robustness are both crucial for the practical applications of all-polymer solar cells (all-PSCs) in stretchable and wearable electronics. In this regard, a series of new polymer acceptors (PAs) is reported by incorporating a flexible conjugation-break spacer (FCBS) to achieve highly efficient and mechanically robust all-PSCs. Incorporation of FCBS affords the effective modulation of the crystallinity and pre-aggregation of the PAs, and achieves the optimal blend morphology with polymer donor (PD), increasing both the photovoltaic and mechanical properties of all-PSCs. In particular, an all-PSC based on PYTS-0.3 PA incorporated with 30% FCBS and PBDB-T PD demonstrates a high power conversion efficiency (PCE) of 14.68% and excellent mechanical stretchability with a crack onset strain (COS) of 21.64% and toughness of 3.86\ua0MJ m-3, which is significantly superior to those of devices with the PA without the FCBS (PYTS-0.0, PCE = 13.01%, and toughness = 2.70\ua0MJ m-3). To date, this COS is the highest value reported for PSCs with PCEs of over 8% without any insulating additives. These results reveal that the introduction of FCBS into the conjugated backbone is a highly feasible strategy to simultaneously improve the PCE and stretchability of PSCs
DNA Sampling: a method for probing protein binding at specific loci on bacterial chromosomes
We describe a protocol, DNA sampling, for the rapid isolation of specific segments of DNA, together with bound proteins, from Escherichia coli K-12. The DNA to be sampled is generated as a discrete fragment within cells by the yeast I-SceI meganuclease, and is purified using FLAG-tagged LacI repressor and beads carrying anti-FLAG antibody. We illustrate the method by investigating the proteins bound to the colicin K gene regulatory region, either before or after induction of the colicin K gene promoter
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