• Energy Research
• 13. Climate action close
• AU close
• University of North Sumatra close

Here, we demonstrate the direct biodiesel production from wet SCG in mild reaction temperature and short reaction time using reactive extraction Soxhlet (RES) method.

This paper aimed to provide a narrative review of the current conditions of orangutan ecotourism on Sumatra Island, problems in the current management systems, and some recommendations for further development. Orangutan conservation centers have been developed on Sumatra Island since 1973. The Bukit Lawang Conservation Station is one of the orangutan conservation centers that have practiced ecotourism to overcome ecological and socio-economic issues. Even though the Bukit Lawang Conservation Station has operated for decades, this station has faced several issues, in particular a monetary crisis in 1997, a flash flood in 2003, and the COVID-19 pandemic. We identified that orangutan conservation centers on Sumatra Island have the potential to support orangutan ecotourism. These conservation centers have ecological support, available facilities, and rich local wisdom that can provide added value for orangutan ecotourism. Therefore, we propose that the development of orangutan ecotourism on Sumatra Island should accommodate surrounding communities through community-based wildlife ecotourism. We also recommend the following strategies to develop orangutan ecotourism on Sumatra Island: (1) mapping the location and distribution of wild orangutans in their natural habitats; (2) managing captive and semi-captive orangutans in conservation centers; (3) provision of tour packages; (4) community empowerment; (5) institutional strengthening of community-based ecotourism management (CBEM); (6) developing ecotourism through a benefit-sharing model; (7) anticipating and minimizing the negative impacts of ecotourism on orangutans; and (8) integrating orangutan tourism with local wisdom.

The Global Plant Health Assessment (GPHA) is a collective, volunteer-based effort to assemble expert opinions on plant health and disease impacts on ecosystem services based on published scientific evidence. The GPHA considers a range of forest, agricultural, and urban systems worldwide. These are referred to as (Ecoregion × Plant System), i.e., selected case examples involving keystone plants in given parts of the world. The GPHA focuses on infectious plant diseases and plant pathogens, but encompasses the abiotic (e.g., temperature, drought, and floods) and other biotic (e.g., animal pests and humans) factors associated with plant health. Among the 33 (Ecoregion × Plant System) considered, 18 are assessed as in fair or poor health, and 20 as in declining health. Much of the observed state of plant health and its trends are driven by a combination of forces, including climate change, species invasions, and human management. Healthy plants ensure (i) provisioning (food, fiber, and material), (ii) regulation (climate, atmosphere, water, and soils), and (iii) cultural (recreation, inspiration, and spiritual) ecosystem services. All these roles that plants play are threatened by plant diseases. Nearly none of these three ecosystem services are assessed as improving. Results indicate that the poor state of plant health in sub-Saharan Africa gravely contributes to food insecurity and environmental degradation. Results further call for the need to improve crop health to ensure food security in the most populated parts of the world, such as in South Asia, where the poorest of the poor, the landless farmers, are at the greatest risk. The overview of results generated from this work identifies directions for future research to be championed by a new generation of scientists and revived public extension services. Breakthroughs from science are needed to (i) gather more data on plant health and its consequences, (ii) identify collective actions to manage plant systems, (iii) exploit the phytobiome diversity in breeding programs, (iv) breed for plant genotypes with resilience to biotic and abiotic stresses, and (v) design and implement plant systems involving the diversity required to ensure their adaptation to current and growing challenges, including climate change and pathogen invasions.

Abstract Bottlenecks on the development of biodiesel production could be eliminated using direct transesterification (DT). This review presents a comprehensive overview for DT from oleaginous seed crops (edible and non-edible), microalgal and fungal/yeast biomass. Effects of key operational parameters, affecting the yield of biodiesel, such as feedstock, feedstock processing technologies, feedstock water content, catalyst choice, temperature, co-solvent and reaction time are summarised and critically assessed. 15% and 68% of published data showed high fatty acid (FA) yields and FA to fatty acid methyl ester (FAME) conversion efficiencies, respectively. Highest fatty acid yielding feedstock were Jatropha and a novel non-edible Mediterranean crop, Cynara cardunculus, the microalgae Chlorella and Nannochloropsis, and the fungi/yeast Trichosporon oleaginosus, Rhodosporidium toruloides, Lipomyces starkeyi, Mortierella isbellina, and Pichia guilliermondi. For wet microalgal biomass, a preference for acid-catalysed direct transesterification was determined, while base-catalysed DT was more suitable for dry biomass, except for turbo-thin film-assisted DT of microalgal biomass. The data highlight that DT operational parameters and technologies need optimisation for feedstock and water content and outcomes may be strongly strain-dependent for microalgal feedstock. To bring commercial biodiesel potential of some high-yielding feedstock to reality, comprehensive life cycle – and techno-economic analyses are required for intensified and non-intensified DT processing, taking feedstock production and possibilities of biorefinery concepts into account whilst also focussing on those processing platforms that can esterify fatty acids in wet biomass.

AbstractAimLarge trees (d.b.h. ≥ 70 cm) store large amounts of biomass. Several studies suggest that large trees may be vulnerable to changing climate, potentially leading to declining forest biomass storage. Here we determine the importance of large trees for tropical forest biomass storage and explore which intrinsic (species trait) and extrinsic (environment) variables are associated with the density of large trees and forest biomass at continental and pan‐tropical scales.LocationPan‐tropical.MethodsAboveground biomass (AGB) was calculated for 120 intact lowland moist forest locations. Linear regression was used to calculate variation in AGB explained by the density of large trees. Akaike information criterion weights (AICc‐wi) were used to calculate averaged correlation coefficients for all possible multiple regression models between AGB/density of large trees and environmental and species trait variables correcting for spatial autocorrelation.ResultsDensity of large trees explained c. 70% of the variation in pan‐tropical AGB and was also responsible for significantly lower AGB in Neotropical [287.8 (mean) ± 105.0 (SD) Mg ha−1] versus Palaeotropical forests (Africa 418.3 ± 91.8 Mg ha−1; Asia 393.3 ± 109.3 Mg ha−1). Pan‐tropical variation in density of large trees and AGB was associated with soil coarseness (negative), soil fertility (positive), community wood density (positive) and dominance of wind dispersed species (positive), temperature in the coldest month (negative), temperature in the warmest month (negative) and rainfall in the wettest month (positive), but results were not always consistent among continents.Main conclusionsDensity of large trees and AGB were significantly associated with climatic variables, indicating that climate change will affect tropical forest biomass storage. Species trait composition will interact with these future biomass changes as they are also affected by a warmer climate. Given the importance of large trees for variation in AGB across the tropics, and their sensitivity to climate change, we emphasize the need for in‐depth analyses of the community dynamics of large trees.

Today, using systems based on renewable resources is a suitable alternative to fossil fuels. However, due to problems such as the lack of access in all the times needed to supply cargo and high-investment cost, it has not been well-received. Therefore, in this research, the modeling of the photovoltaic system with battery storage has been done to supply the required load, and various scenarios have been evaluated in terms of economic parameters and reliability indicators of the studied system for a better understanding of the comparison indicators. It has been evaluated from two modes, one connected to the network and one disconnected from the network. One of the important results is the supply of 56% of the load by the photovoltaic cell in the presence of the grid, which, in this scenario, the electrical load is supplied by the photovoltaic cell and the grid is 164.155 kWh/yr and 128.504 kWh/yr, respectively.

Refereed/Peer-reviewed The dark side of the consumption of Natural Resources (NTR) is the carbon dioxide emissions (CO2) resulting from the extraction of NTR as well as the increasing level of consumption within the economy. Besides, the massive expansion and growth of the Chinese economy have also meant its CO2 is at an all-time high, thus making China one of the leading contributors to global warming. Hence the current study fills a knowledge vacuum by analyzing the relationships governing NTR and technological innovation (TIN) in countering the environmental damage due to CO2, by revisiting the EKC in the Chinese context through “Quantile Autoregressive Distributed Lag” (QARDL). The results validate the EKC where NTR consumption worsens the environment further; however, TIN is a potential solution in countering CO2. In accordance with the findings, it is recommended that government institutions need to ensure the preservation of NTR without conceding the economic benefits and prosperity.