This comprehensive study unveils the vast global potential of microalgae as a sustainable bioenergy source, focusing on the utilization of marginal lands and employing advanced machine learning techniques to predict biomass productivity. By identifying approximately 7.37 million square kilometers of marginal lands suitable for microalgae cultivation, this research uncovers the extensive potential of these underutilized areas, particularly within equatorial and low-latitude regions, for microalgae bioenergy development. This approach mitigates the competition for food resources and conserves freshwater supplies. Utilizing cutting-edge machine learning algorithms based on robust datasets from global microalgae cultivation experiments spanning 1994 to 2017, this study integrates essential environmental variables to map out a detailed projection of potential yields across a variety of landscapes. The analysis further delineates the bioenergy and carbon sequestration potential across two effective cultivation methods: Photobioreactors (PBRs), and Open Ponds, with PBRs showcasing exceptional productivity, with a global average daily biomass productivity of 142.81mgL
Creep is an inherent property of concrete materials, and an accurate prediction of creep-induced prestress is critical in designing a prestressed concrete structure. The comparison of codes or specifications of different countries on concrete structures was performed in this study. A basic model of prestress loss caused by creep was first deduced from a simple engineering model, and then the derived model was compared with the calculations obtained by different codes. Results show that the overall fundamentals and considerations of these codes are similar. Among these codes, the formulas specified by the Chinese Codes, European Code (DD ENV 1992-1-1), and AASHTO Code (AASHTO LRFDUS-5-M) were similar to the concrete aging formula, while the ACI Code (ACI 209 R-92), Australian Code (ACI 209R-92), and Canadian Code (CSA-S6-06) depended more on empirical coefficients obtained via experiments. In the calculation example, the value of creep coefficient directly affected the calculated result of prestress loss. By comparing the creep models adopted in Code for Design of Concrete Structures (GB50010-2010), European Code (DD ENV 1992-1-1), ACI Code (ACI 209R-92), and Railway Code (TB10002.3-2005) the effects of input parameters on calculation of creep coefficient were discussed in details. This study revealed the appropriate conditions using different codes.
In order to solve the most difficult problem of the architectural model established by CNN in solving specific problems, which results in parameter overflow and inefficient training, an optimization algorithm for nonlinear convolutional neural networks based on improved chameleon swarm algorithm is proposed. This article mainly introduces the use of Chameleon Swarm Optimization (PSO) algorithm to research the parameters of CNN architecture, solve them, and achieve the optimization of the optimization model.Although the number of parameters that need to be set up in CNN is very large, this method can find better testing space for Alexnet samples with 5 different images. In order to improve the performance of the improved pruning algorithms, two candidate pruning algorithms are also proposed. The experimental results show that compared with the traditional Alexnet model, the improved pruning method improves the image recognition ability of the Caffe primary parameter set from 1.3% to 5.7%. This method has wide applicability and can be applied to most neural networks which do not require any special functional modules of the Alexnet network model.
Microalgae have emerged as a promising feedstock for biofuels and high-value compounds, o ff ering potential solutions to global energy and resource challenges. This comprehensive review examines the latest advancements in microalgae cultivation technologies, focusing on both open systems and enclosed photobioreactors (PBRs). We analyze various configurations including open raceway ponds, tubular PBRs, flat panel PBRs, and novel designs such as the Light Exchange Bubble-column (LEB). The review encompasses key performance indicators such as biomass productivity, energy e ffi ciency, and water usage, as well as life cycle assessment (LCA) results for di ff erent cultivation systems. We also discuss the challenges and opportunities in scaling up microalgae production, the potential for integrating wastewater treatment and CO 2 mitigation, and the prospects of biorefinery approaches. By synthesizing recent research findings and identifying knowledge gaps, this review aims to provide a comprehensive understanding of the current state and future directions in sustainable microalgae cultivation for researchers, engineers, and policymakers in the field of renewable energy and biotechnology.
Water is needed to generate energy. Energy is required to deliver, clean, and evaporate water. There are extensive linkages between water and energy. Meanwhile, both resources may limit the other, especially in the context of urbanization and industrialization as well as climate change. Due to the large population and fast-growing economy, China is one of the most water and energy shortage countries in the world. Relations between water and energy are particularly strained. Unfortunately, up to now, little attention has been paid to the tension relation between water and energy in China. Studying water and energy nexus can provide more information than investigating them separately because of their concomitant relationship. In this paper, we reviewed the recent situations on these issues in China, mainly focused on the following topics: 1) energy consumption in water industry; 2) water consumption and energy nexus in energy industry and urban; 3) water and energy nexus in agriculture; and 4) Energy consumption by evapotranspiration and its cooling effect on reducing urban temperature. Extensive data are analyzed and reported in this study, which will be useful for policy making by taking account of climate change, urbanization, and population growth.
<p>Petrochemical fuel usage abuse has caused the depletion of oil reservoirs and increasing environmental problems such as greenhouse gas emission and global warming. Therefore, it is necessary to develop greener and sustainable alternatives. Carbon dioxide is the main contributor to the global warming crisis. Biomass energy has received the most attention in many integrated assessment model studies and the latest IPCC reports. Among various existing carbon capture technologies, microalgae-based biological carbon capture is one of the promising and lower energy consumption technologies.</p><p>&#160;</p><p>Microalgae rise as 3rd generation bioenergy feedstock due to its attractive higher carbon dioxide fixation efficiency, higher biomass productivity, and relatively easy pretreatment processes for various biofuel extractions. Besides, microalgae have a low demand for water quality and soil fertility compared to traditional energy plants. It means growing microalgae on the marginal land (non-fertile land that is not suitable for agriculture) could be a promising agent for bioenergy production and CO<sub>2</sub> mitigation.</p><p>&#160;</p><p>The study is aimed to evaluate the potential energy production from microalgae on marginal land. We combined geospatial data with climate, soil, and terrain to estimate the marginal land of each country. By using Williams and Laurens&#8217; model (2010), we calculated the annual microalgae areal biomass yields for different latitudes and evaluated annual potential energy production from microalgae on marginal land. It is estimated that microalgae may generate up to 67.9 billion tons of coal equivalent of potential energy per year on the total marginal land. By replacing fossil fuels, there will be emission reduction potential 290.6 billion tons of carbon dioxide.</p>
A modified Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) method for the simultaneous determination of spirotetramat and its four metabolite residues in citrus, peel, pulp and soil was developed and validated by liquid chromatography with tandem mass spectrometry (LC-MS/MS). The samples were extracted with acetonitrile (1%, glacial acetic acid, v/v) and purified using primary secondary amine and octadecylsilane. The limit of detection was 0.01-0.13 mg/kg, whereas that of quantification was 0.02-0.40 mg/kg for spirotetramat and its metabolites. The average recoveries of spirotetramat, spirotetramat-enol, spirotetramat-mono-hydroxy, spirotetramat-enol-glucoside and spirotetramat-ketohydroxy in all matrices were 73.33-107.91%, 75.93-114.85%, 76.44-100.78%, 71.46-103.19% and 73.08-105.27%, respectively, with relative standard deviations < 12.32%. The dissipation dynamics of spirotetramat in citrus and soil followed first-order kinetics, with half-lives of 2.3-8.5 days in the three sampling locations. The terminal residues of spirotetramat in four matrices at the three locations were measured below the 1.0 mg/kg maximum residue limit set by China, and residues were found to be concentrated on the peel. The risk assessment of citrus was evaluated using risk quotients. The risk quotient values were found to be significantly <1, suggesting that the risk to human health was negligible when using the recommended doses of spirotetramat in citrus. These results could provide guidance for the safe and proper application of spirotetramat in citrus in China.
Abstract According to the life cycle theory, the project analyzed the energy consumption of the entire asphalt pavement construction process, and clarified the energy consumption monitoring method of key nodes during the asphalt pavement construction period and the energy consumption boundary of each link during the construction period; the raw materials used for the asphalt pavement and each link during the construction period The energy consumption was compared and analyzed, the key nodes of energy consumption control during the asphalt pavement construction period were clarified, the energy consumption of different asphalt mixtures were compared and analyzed, and the asphalt pavement energy consumption evaluation system was established.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)