A series of commercially available (and low-cost) silica gels were amine-grafted under dry conditions using N 1-(3-trimethoxysilylpropyl)diethylenetriamine (i.e., “triamine”). CO2 capture ...performance, pore properties, and amine loading were investigated, and the results showed that the silica gel with the largest pores (150A) was the most suitable for further enhancement. Amine loading needed to be increased in order to further enhance the CO2 adsorption capacity. The addition of water during the grafting process was implemented on the 150A silica gel. The wet-grafted 150A silica gel exhibited a 2.3 mmol/g adsorption capacity at 75 °C and 1 bar, which is comparable to the best literature reported values that used similar synthesis methods. The wet-grafted 150A exhibited good cycle stability as well as fast CO2 uptake rates. The fixed-bed breakthrough capacity for air capture (ambient air with 415 ppm of CO2 at 25 °C) under dry (0.773 mmol/g) and wet (1.098 mmol/g) conditions are among the highest CO2 capacities for air capture. The capacity of the low-surface area silica gel (150A, S.A. = 309 m2/g) rivaled those of the best of the SBA and MCM type materials, which was unexpected. These results indicate that wet-grafted silica gel 150A is a promising and low-cost sorbent for direct capture of CO2 from ambient air and flue gas applications.
This book is the first scholarly edition of the most popular Native American captivity narrative published in eighteenth-century Britain. In this fully annotated modern version, Timothy J. Shannon ...re-acquaints modern readers with this popular North American captivity narrative, featuring a Scottish protagonist. He tells the story of Peter Williamson, a native of Aberdeen, who claimed he was kidnapped into indentured servitude in North America, lived as a captive among Indians there, and then fought as a soldier in the Seven Years' War until he was taken prisoner by the French. After returning to Britain, Williamson peddled his tale while dressed in Indian costume, and he eventually settled in Edinburgh, where he became known as 'Indian Peter'.
The degrading environment of the planet is something that touches everyone. This 2011 book offers an introductory overview of literary and cultural criticism that concerns environmental crisis in ...some form. Both as a way of reading texts and as a theoretical approach to culture more generally, 'ecocriticism' is a varied and fast-changing set of practices which challenges inherited thinking and practice in the reading of literature and culture. This introduction defines what ecocriticism is, its methods, arguments and concepts, and will enable students to look at texts in a wholly new way. Boxed sections explain key critical terms and contemporary debates in the field with 'hands-on' examples and comparisons. Timothy Clark's thoughtful approach makes this an ideal first encounter with environmental readings of literature.
•Amine grafted bimodal silica exhibit high CO2 capacity, amine efficiency, and selectivity.•The direct air capture capacity at 415 ppm CO2 was 1.04 mmol/g.•Bimodal structures improve the dispersion ...of grafted amines.
Amine grafting under hydrous conditions is emerging as a promising solution to developing amine grafted adsorbents with high amine loading and superior capture performance. In this study, a hierarchical bimodal mesoporous silica (HBS) that can be easily and cost-effectively synthesized was identified. Subsequently, HBS was amine grafted in anhydrous and hydrous conditions. The resulting material and its adsorptive performance were investigated. Hierarchical bimodal silica supports allow aminosilanes to more easily access the deep channels of the pores resulting in greater amine dispersion than SBA-15 type supports. The CO2 adsorption capacity of amine grafted hierarchical bimodal silica adsorbents and SBA-15 type adsorbents were measured at 25, 75, 90, 100 °C. The CO2 adsorption capacity and amine efficiency (reached 0.41 mol CO2/mol N) were significantly higher than that of SBA-15 type adsorbents. This is because HBS possesses two series of mesopores as opposed to one which promotes the diffusion of CO2 and allows for greater amine dispersion and consequently greater amine utilization. Wet grafted HBS displayed excellent cyclic stability after approximately 10 adsorption-desorption cycles. Under dry conditions and using ambient air containing 415 ppm of CO2 at 25 °C, the fixed bed breakthrough capacity of WG-HBS-0.6 was 1.04 mmol/g. To the best of our knowledge, the CO2 adsorption capacity and the direct air capture capacity exceed reported literature values for amine-grafted silica adsorbents. At similar amine loadings the H2S adsorption capacity of wet grafted hierarchical bimodal silica was similar to SBA-15 type adsorbents suggesting thermodynamics as opposed to pore structure plays a greater role during the H2S adsorption process. From the obtained results, hierarchical bimodal silicas are promising adsorbents for the capture of CO2 from ambient air and industrial gas streams and are also suitable for the removal of H2S.
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•Boron-doped SBA-15 mesoporous silica was subjected to an acid treatment to remove boron.•The acid treatment forms “hydroxyl nests” that increase the surface silanol density.•The ...increased silanols led to higher amine grafting and consequently significantly increased CO2 capacities (by more than 100%).•This novel method was tested under DAC conditions with both dry and humid air feed.
Among the most studied adsorbents for CO2 capture is amine-grafted mesoporous silica SBA-15. In this work, boron, a heteroatom, was incorporated into the SBA-15 framework and removed by acid treatment to increase the amount of surface hydroxyl groups. It was discovered that the removal of boron resulted in the formation of silanol nests, with four silanol groups in each nest. Compared with the common method of air calcination for SBA-15, acid-treated boron doped SBA-15, exhibited higher silanol density, as well as higher amine loading after amine grafting. This work is the first to study the use of the silanol nests to graft amines and interact with CO2 directly; the results show more than doubling of the CO2 adsorption capacity for direct air capture.
Drought is one of the most severe stresses, endangering crop yields worldwide. In order to select drought tolerant genotypes, access to exotic germplasm and efficient phenotyping protocols are ...needed. In this study the high-throughput phenotyping platform "The Plant Accelerator", Adelaide, Australia, was used to screen a set of 47 juvenile (six week old) wild barley introgression lines (S42ILs) for drought stress responses. The kinetics of growth development was evaluated under early drought stress and well watered treatments. High correlation (r=0.98) between image based biomass estimates and actual biomass was demonstrated, and the suitability of the system to accurately and non-destructively estimate biomass was validated. Subsequently, quantitative trait loci (QTL) were located, which contributed to the genetic control of growth under drought stress. In total, 44 QTL for eleven out of 14 investigated traits were mapped, which for example controlled growth rate and water use efficiency. The correspondence of those QTL with QTL previously identified in field trials is shown. For instance, six out of eight QTL controlling plant height were also found in previous field and glasshouse studies with the same introgression lines. This indicates that phenotyping juvenile plants may assist in predicting adult plant performance. In addition, favorable wild barley alleles for growth and biomass parameters were detected, for instance, a QTL that increased biomass by approximately 36%. In particular, introgression line S42IL-121 revealed improved growth under drought stress compared to the control Scarlett. The introgression line showed a similar behavior in previous field experiments, indicating that S42IL-121 may be an attractive donor for breeding of drought tolerant barley cultivars.
There is a deeply relational aspect to the systems people employ for sorting through and prioritizing plural values assigned to social–ecological interactions. Spurred by interpersonal relationships ...and adhesion to societal core values, such as justice and reciprocity, relational values go beyond instrumental and intrinsic approaches to understanding human behaviour vis-à-vis the environment. Currently, this relational dimension of values is entering the spotlight of the cultural ecosystem services (CES) literature focusing on non-material benefits and values people derive from ecosystems, such as aesthetics and sense of place. Relational values foster reflections on appropriateness and morality of preferences and respective behaviours in contributing to collective flourishment across space and time, holding implications for social–ecological justice and sustainability. Recently, several studies explored the potential of using social media data for assessing values ascribed to CES, but did not look at how this emerging approach could contribute to an enhanced understanding of relational values. In order to take up this goal, we conducted a systematic review, screening 140 publications and selecting 29 as relevant for exploring the extent to which relational CES values are inferable through social media. Our results show that social media data can reveal CES values’ plural and relational dimension. Social media platforms, thus, can be understood as new arenas for the co-construction of values, where relational values stemming from social–ecological interactions are negotiated and defined. Yet, work on their implications for social–ecological justice and sustainability needs to be extended.
•Grafting at 30 °C as opposed to 85 °C resulted in higher amine loading.•30 °C grafted silica had higher CO2 capacity at 75 °C than 85 °C grafted silica.•Grafting at 30 °C doesn’t change the amine ...properties or configuration.•Influence of grafting at 30 °C was demonstrated for different silicas & silanes.
SBA-15 was employed to study amine-grafting in dry and wet grafting conditions at low temperature. SBA-15 was amine-grafted at 30 °C and for contrast SBA-15 was conventionally grafted at 85 °C to determine how amine-grafting at 30 °C affects amine-grafting outcomes. It was found that under dry grafting conditions, adsorbents grafted at 30 and 85 °C exhibited similar amine loadings. It was also found that when water was added during grafting, adsorbents grafted at 30 °C displayed higher amine loadings than those at 85 °C. At 30 °C, more water can occupy the pore space of the SBA-15 prior to clogging of the pores, resulting in higher amine loading. This results in higher CO2 capacities at 75 °C for adsorbents grafted at 30 °C. The stability of materials grafted at 30 °C and the universality of the studied effects for other aminosilanes and mesoporous silica supports were demonstrated.
Summary
The scope and scale of wildlife crimes around the world have risen in intensity and complexity, yet current enforcement strategies have often not delivered desired effects on illegal ...activities, even within protected areas. Tackling the array of illegal activities by emphasizing law enforcement above other options is challenging and potentially unsustainable. We explored the potential for social norms, community regulations and socioeconomic factors to promote compliance with wildlife laws by interviewing 334 respondents in 28 villages that share boundaries with protected areas in Nigeria. Using an anonymous direct questioning approach, we recorded a high prevalence of non-compliance behaviours in all studied communities. Injunctive norms (i.e., perceptions of acceptable behaviour within a social group) significantly predicted compliance, as respondents with no complicit friends or family members were more likely to comply with wildlife regulations. Perceived likelihood of community-level sanctions played a more salient role than the fear of arrest by rangers in influencing compliance. In addition, non-compliance increased with number of dependents, but reduced with average monthly household income. Our study demonstrates that clear knowledge of the social norms that drive local behaviour as well as the authorities that enforce them is integral to understanding the forces that drive community involvement and participation in conservation. Incorporating local communities in planning enforcement interventions may help protect threatened species and landscapes.
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