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Aromatization of furan and substituted furans over zeolite catalysts is a promising reaction to convert cellulose-derived compounds into valuable aromatic hydrocarbons and light olefins. A lack of understanding of the reaction mechanism however hinders further development of this process. Here, we propose the reaction mechanism, underlying the chemistry of furan and methanol co-aromatization over HZSM-5 zeolite catalyst. Applying 13C isotope labeling in a combination with NMR spectroscopy and high temporal resolution gas chromatography-mass spectrometry analysis, we demonstrate that aromatization of furan and methanol are not mechanistically separated and can be described within the dual-cycle hydrocarbon pool mechanism. Cofeeding furan with methanol leads to a significant enhancement of light aromatics selectivity and increased catalyst lifetime.

Abstract With the rapid advancement in wearable electronics, energy harvesting devices based on triboelectric nanogenerators (TENGs) have been intensively investigated for providing sustainable power supply for them. However, the fabrication of wearable TENGs still remains great challenges, such as flexibility, breathability and washability. Here, a route to develop a new kind of woven-structured triboelectric nanogenerator (WS-TENG) with a facile, low-cost, and scalable electrospinning technique is reported. The WS-TENG is fabricated with commercial stainless-steel yarns wrapped by electrospun polyamide 66 nanofiber and poly(vinylidenefluoride-co-trifluoroethylene) nanofiber, respectively. Triggered by diversified friction materials under a working principle of freestanding mode, the open-circuit voltage, short-circuit current and maximum instantaneous power density from the WS-TENG can reach up to 166 V, 8.5 µA and 93 mW/m2, respectively. By virtue of high flexibility, desirable breathability, washability and excellent durability, the fabricated WS-TENG is demonstrated to be a reliable power textile to light up 58 light-emitting diodes (LED) connected serially, charge commercial capacitors and drive portable electronics. A smart glove with stitched WS-TENGs is made to detect finger motion in different circumstances. The work presents a new approach for self-powered textiles with potential applications in biomechanical energy harvesting, wearable electronics and human motion monitoring.

Background: The global palm oil market experienced a remarkable boom since the year 2000. Since palm oil can be used for biodiesel production, the global expansion of oil palm cultivation has been associated with the global biofuel boom. Biofuel policies—especially those adopted in the European Union (EU)—have been blamed for the socio-environmental impacts of oil palm expansion. We explore how the global biofuel boom interacts with national geographies and social-economic and political processes to produce country-specific trajectories of biofuel crops expansion. We analyse the expansion of oil palm cultivation in Colombia between 2000 and 2010 from a political ecology perspective. Methods: The analysis is based on a framework that positions expansion of commodity frontiers within the ‘space-of-flows’ and the ‘space-of-place’. Through this approach, we identify the markets and geographies that define the country-specific trajectories of expansion of oil palm in Colombia, and their connections with general patterns of land control. The empirical analysis is based on primary data collected during fieldwork, and on an extensive review of secondary data about the palm oil sector and the socio-environmental effects of oil palm expansion in the country. Results: The contemporary oil palm expansion in Colombia was not specifically influenced by the international biofuel market. Expansion was characterized by an increasing production of palm oil for biodiesel, to supply a policy-driven national biofuel market controlled by national palm oil producers. The evidence shows that this oil palm expansion proceeded through a variety of land control practices that constitute forms of ‘accumulation by dispossession’ and ‘assimilation’. These are embedded in contextual factors that include the agrarian history of Colombia, the armed conflict, and government policies. Conclusions: Our study shows that the ways in which expansion of biofuel crops unfold in each producing country depend not only on the global biofuel market. They are also shaped by the country-specific geographies and political economies. Therefore, research and policies on the global expansion of energy crops should account for the complex and interrelated factors that mediate the specific ways in which the global demand for biofuels creates biofuel crop booms at country level.

Climate change, environmental degradation, and limited resources are motivations for sustainable forest management. Forests, the most abundant renewable resource on earth, used to make a wide variety of forest-based products for human consumption. To provide a scientific measure of a product’s sustainability and environmental performance, the life cycle assessment (LCA) method is used. This article provides a comprehensive review of environmental performances of forest-based products including traditional building products, emerging (mass-timber) building products and nanomaterials using attributional LCA. Across the supply chain, the product manufacturing life-cycle stage tends to have the largest environmental impacts. However, forest management activities and logistics tend to have the greatest economic impact. In addition, environmental trade-offs exist when regulating emissions as indicated by the latest traditional wood building product LCAs. Interpretation of these LCA results can guide new product development using biomaterials, future (mass) building systems and policy-making on mitigating climate change. Key challenges include handling of uncertainties in the supply chain and complex interactions of environment, material conversion, resource use for product production and quantifying the emissions released.

A method is presented for calculating the electromagnetic forces on the end windings of turbine generators for both the steady state and transient modes of operation. Part 1 of this paper deals with the basic concepts of the force calculation and gives several examples of steady state forces and how they vary with load and power factor. PartII deals with several types of transient operation. The currents and fields which these transients produce are discussed and forces are found for various cases such as short circuits, synchronizing out of phase and transmission line switching.

Abstract This article is a survey of the theoretical questions arising in the development of a convergence theory and error analysis of synthesis methods for solving neutron diffusion problems. For simplicity, we discuss convergence and the error analysis for spectral synthesis methods, in which the trial functions are functions solely of energy. The diffusion coefficient, the total and scattering cross-section data for the diffusion model are assumed spatially and energy dependent, and interior interfaces (i.e. spatial discontinuities in the diffusion coefficient and cross-section data) are present. The boundary conditions imposed are homogeneous Dirichlet conditions.

The Social-Ecological Systems (SES) framework serves as a valuable framework to explore and understand social and ecological interactions, and pathways in water governance. Yet, it lacks a robust understanding of change. We argue an analytical and methodological approach to engaging global changes in SES is critical to strengthening the scope and relevance of the SES framework. Relying on SES and resilience thinking, we propose an institutional and cognitive model of change that institutions and natural resources systems co-evolve to provide a dynamic understanding of SES that stands on three causal mechanisms: institutional complexity trap, rigidity trap, and learning processes. We illustrate how Data Cube technology could overcome current limitations and offer reliable avenues to test hypothesis about the dynamics of social-ecological systems and water security by offering to combine spatial and time data with no major technical requirements for users.

In Cameroon, as in other countries of the Congo basin region, policy processes and activities related to climate change have been hitherto geared mostly towards mitigation and related questions, with limited concern about adaptation issues. However, the increasing vulnerability of Cameroon to climate variability and change makes adaptation significant to its national climate-change policy. Nonetheless, it remains a challenge to make both adaptation and mitigation occupy the same policy space in Cameroon. This paper builds partly on studies carried out in two community forest carbon initiatives in the southern rainforest of Cameroon. It also argues, supported by existing literature on adaptation and mitigation, that mitigation activities have the potential to produce adaptation outcomes; a situation which avoids duplication of efforts and waste of financial and technical resources, if synergetic options are anticipated and planned. However, whether such integrated approaches succeed and are subsequently reflected in national-level climate policy depends on how actors across different sectors and at different levels engage and carry out their roles. The paper discusses these roles and how they can support each other in pursuing integrated initiatives – a context which is vital for Cameroon.

Since long ago, pelagic Sargassum mats have been known to be abundant in the Sargasso Sea, where they provide habitat to diverse organisms. However, over the last few years, massive amounts of pelagic Sargassum have reached the coast of several countries in the Caribbean and West Africa, causing economic and environmental problems. Aiming for lessening the impacts of the blooms, governments and private companies remove the seaweeds from the shore, but this process results expensive. The valorization of this abundant biomass can render Sargassum tides into an economic opportunity and concurrently solve their associated environmental problems. Despite the diverse fields where algae have found applications and the relevance of this recurrent situation, Sargassum biomass remains without large scale applications. Therefore, this review aims to present the potential uses of these algae, identifying the limitations that must be assessed to effectively valorize this bioresource. Due to the constraints identified for each of the presented applications, it is concluded that a biorefinery approach should be developed to effectively valorize this abundant biomass. However, there is an urgent need for investigations focusing on holopelagic Sargassum to be able to truly valorize this seaweed.