Found 197 results
Review
24 May 2024Current Progress on Microbial l -malic Acid Production
As an important
intermediate in the tricarboxylic acid (TCA) cycle,
Article
08 May 2024Assessing Drone Return-to-Home Landing Accuracy in a Woodland Landscape
While aerial photography continues to play an integral role in forest management, its data acquisition can now be obtained through an unmanned aerial vehicle (UAV), commonly referred as a drone, instead of conventional manned aircraft. With its feasibility, a drone can be programed to take off, fly over an area following predefined paths and take images, then return to the home spot automatically. When flying over forests, it requires that there is an open space for a vertical takeoff drone to take off vertically and return safely. Hence, the automatic return-to-home feature on the drone is crucial when operating in a woodland landscape. In this project, we assessed the return-to-home landing accuracy based on a permanently marked launch pad nested in a wooded area on the campus of Stephen F. Austin State University in Nacogdoches, Texas. We compared four models of the DJI drone line, with each flown 30 missions over multiple days under different weather conditions. When each drone returned to the home launch spot and landed, the distance and direction from the launch spot to the landing position was measured. Results showed that both the Phantom 4 Advanced and the Spark had superior landing accuracy, whereas the Phantom 3 Advanced was the least accurate trailing behind the Phantom 4 Pro.
Article
06 May 2024Assessing Energy Emissions and Environmental Impact of Wool Processing: A Case Study of an Indian Textile Mill
The objective of this study is to investigate and analyze the effect of varying sources of energy inputs and their impact on carbon emissions during wool fiber processing. The method involved industrial visits to the textile wool processing mill and interaction with the manufacturing as well as commercial sourcing teams to gather relevant data. The results and outcome of this analysis indicate that wool wet processing is responsible for a significant carbon emission of about 0.031 tCO2e/unit of production. Coal as a source of energy has the highest carbon emission 0.066 tCO2e/product, while the use of biomass and Pressurized Natural Gas (PNG) had significantly lower CO2 emissions. Further, this study evaluated the scope 1 and scope 2 category emissions produced at the wool processing stage which accounted for 56303.2 tCO2e and 1817.10 tCO2e respectively.
Article
26 April 2024Exact and Heuristic Approaches to Surveillance Routing with a Minimum Number of Drones
The rising cost and scarcity of human labor pose challenges in security patrolling tasks, such as facility security. Drones offer a promising solution to replace human patrols. This paper proposes two methods for finding the minimum number of drones required for efficient surveillance routing: an ILP-based method and a greedy method. We evaluate these methods through experiments, comparing the minimum number of required drones and algorithm runtime. The findings indicate that the ILP-based method consistently yields the same or a lower number of drones needed for surveillance compared to the greedy method, with a 73.3% success rate in achieving better results. However, the greedy method consistently finishes within one second, whereas the ILP-based method sometimes significantly increases when dealing with 14 more locations. As a case study, we apply the greedy method to identify the minimum drone surveillance route for the Osaka-Ibaraki Campus of Ritsumeikan University.
Commentary
25 April 2024Monitoring Complexity in Clean Energy Systems Applications
Clean energy applications often involve systems with technological process monitoring. This supervision aims to optimize operation, in particular efficiency, performance and compatibility with dedicated criteria. Most of these energy systems involve complex procedures. A complex procedure is an arrangement of compound processes interacting in interdependent behaviors. The supervision of these complex procedures focuses on the interaction of compound processes, their digital coupling and the handling of uncertainties in their detection and digital tools. Real-virtual pairs, such as digital twins, could carry out such surveillance. This commentary aims to analyze and illustrate such supervision in clean electromagnetic energy systems based on a review of the literature. The notion of complexity and the interactions of the compound processes involved are first addressed and detailed. The modeling of these interactions is presented through the mathematical coupling of the electromagnetic equations with other equations of the phenomena involved. These phenomena are linked to the functional or environmental behaviors of the systems. Compound process monitoring in complex procedures is then analyzed taking into account threats, unsolicited external events and uncertainties related to the sensing and digital tools involved. This contribution illustrated several points relating to, the relationship between the complexities of a real energy procedure and its coupled virtual model, the dependence of the model reduction strategy on each specific application and the reduction of uncertainties through the matching of real-virtual pairs. The different analyses are supported by literature references permitting more information when necessary.
Article
23 April 2024Visible Light-Driven H2O2 Photoelectrocatalytic Synthesis Over a Tandem Electrode Strategy
Photocatalytic synthesis of hydrogen peroxide (H2O2) can be an environmentally friendly and energy-saving solution. However, the oxygen reduction reaction (ORR) rate is limited due to the low solubility of O2 in water. In this study, a modified BiVO4 (BVO) photoanode combined with an Sn-coordinated phthalocyanine gas diffusion electrode (SnPc-GDE) was employed for the synthesis of H2O2, and the oxy-gen reduction reaction rate was increased through a unique three-phase interface system. When visible light was irradiated on the BVO photoanode, the hole-electron pairs were excited and the oxygen evolution reaction (OER) was driven through the holes, and the excited electrons were transferred to the SnPc-GDE to reduce O2 for the synthesis of H2O2. Oxygen vacancy enrichment on the BVO electrode was achieved by photoetching and annealing under an N2 atmosphere, which effectively improved the carrier separation efficiency. Complexation with a WO3 layer formed a built-in electric field, which further promoted the electron-hole pair separation. The SnPc catalyst-modified GDE electrode has the best selectivity for ORR and remains stable during long-term reactions. Under bias-free conditions, the generation rate of H2O2 reached 952.5 μM·L−1·h−1, with a Faradaic efficiency of 48.4%. This study provided a practical strategy for designing a highly efficient BVO/SnPc-GDE photoelectrochemical system to produce H2O2 based on improvement in electron-hole transmission efficiency and product selectivity.
Article
19 April 2024Can Digital Village Construction Reduce Rural Income Disparity?—Empirical Analysis Based on Inter-provincial Panel Data in China
Cutting the income disparity within rural areas is one of the key priorities in seeking common prosperity in China. Based on the panel data of 20 provinces in China from 2011 to 2020, we empirically analyze the impact of digital village construction on rural income disparity by building a digital village construction level indicator system which represents three dimensions of digitalization in rural areas, i.e., digitalization of rural infrastructure, digitalization of agricultural development and digitalization of rural residents’ life. Overall, the level of digital village construction in rural China has shown a development trend of gradual improvement, while the development level in various regions is unbalanced and varies greatly. The results of the fixed-effect model show that, digital village construction can significantly reduce the income disparity in rural areas, whereas the effect is significant in eastern China, insignificant in central and western China. It is recommended to increase the investment in funds and talents and take full consideration and advantage of local conditions, while promoting the development of new rural digital economy, so to achieve the development goal of common prosperity of rural residents.
Article
15 April 2024Impacts on the Legal Framework for Protecting Environmental and Human Rights in Brazil due to Ideological Antagonism: The Interrelated Cases of the Yanomami and the Amazon Fund
The occupation of the Amazon is driven by capitalist production, impacting climate change discussions. Despite constitutional protections since 1934, the influx of non-Indigenous settlers, particularly miners, led to significant conflicts. The Yanomami sought international recourse through the Inter-American Commission on Human Rights (IACHR). In the context of redemocratization, the 1988 Constitution marked a shift, reinforcing Indigenous rights and environmental protection. Brazil’s role in protecting the rainforest intersects with global climate efforts, including the REDD+ mechanism. The creation of the Amazon Fund in 2008, aligned with REDD+ initiatives, involved international cooperation and local governance, leading to a substantial decline in Amazon deforestation between 2004 and 2012. However, exploitative practices endorsed by the State pose threats to environmental and human rights, notably affecting indigenous communities. Amid Brazil’s democracy crisis, deforestation surged in the Amazon from 2013–2022 and the Yanomami face conflicts fueled by State support for non-Indigenous groups. The Yanomami sought international recourse through the IACHR and the Inter-American Court of Human Rights. These issues are intensified by an ideological bias, linked to authoritarian populism rooted in the legacy of the Dictatorship. Recent initiatives aim to enhance environmental and human rights protection. However, political instability poses challenges for the future.
Review
08 April 2024Tolerance in Solventogenic Clostridia for Enhanced Butanol Production: Genetic Mechanisms and Recent Strain Engineering Advances
Biobutanol is a promising candidate for replacing fossil fuels due to its superior properties compared to ethanol. Solventogenic clostridia can naturally produce biobutanol among other valuable chemicals. Lignocellulosic material stands out as a promising source for biobutanol production, avoiding competition with food production and making use of residues from both agroindustry and forestry activities. However, Clostridium strains are subject to different chemical stressors, including oxygen, self-product inhibition, inhibitors generated during biomass pretreatment and hydrolysis, and others. Recent advances in genetic engineering tools have enabled the metabolic engineering of Clostridium strains to increase their robustness and tolerance to these stressors. This review provides a summary of the various types of inhibitors, the genetic mechanisms related to tolerance, and recent strain engineering efforts for tolerance enhancement. In addition, we offer a valuable perspective on the future research directions in this area.
Review
02 April 2024Mapping the (in)Effective Enforcement of EU Environmental Law in Greece: Lessons from the EU and Domestic Courts
The effective implementation and enforcement of EU environmental law at national level constitutes a thorny issue with both legal and practical aspects. Greece is among the EU Member States which has historically faced difficulties in complying with the EU environmental acquis due to the poor functioning of the Greek administration, the limited manpower, expertise and resources (especially during the recent period of the economic crisis) for the competent authorities, the lack of political will, the low awareness of environmental problems. In this context, this paper aspires to unpack these enforcement challenges at the national level based on the case law of both the Greek Council of State and the Court of Justice of the European Union. Considering that waste management, nature protection, and water and air quality sectors are recognized as areas with the most significant deficiencies in implementation at the domestic level, the analysis will focus on these four key sectors. To this end, by reviewing the relevant EU and Greek jurisprudence, this paper aspires to identify the disparities between the formal requirements and the practical application of EU environmental regulations in Greece in light of the national political, economic, social, and cultural dynamics.