Hasil untuk "Environmental engineering"

T. Kelley, J. Knowles

The global urgency to improve STEM education may be driven by environmental and social impacts of the twenty-first century which in turn jeopardizes global security and economic stability. The complexity of these global factors reach beyond just helping students achieve high scores in math and science assessments. Friedman (The world is flat: A brief history of the twenty-first century, 2005) helped illustrate the complexity of a global society, and educators must help students prepare for this global shift. In response to these challenges, the USA experienced massive STEM educational reforms in the last two decades. In practice, STEM educators lack cohesive understanding of STEM education. Therefore, they could benefit from a STEM education conceptual framework. The process of integrating science, technology, engineering, and mathematics in authentic contexts can be as complex as the global challenges that demand a new generation of STEM experts. Educational researchers indicate that teachers struggle to make connections across the STEM disciplines. Consequently, students are often disinterested in science and math when they learn in an isolated and disjoined manner missing connections to crosscutting concepts and real-world applications. The following paper will operationalize STEM education key concepts and blend learning theories to build an integrated STEM education framework to assist in further researching integrated STEM education.

L. Szabados, A. Savouré

P. Deb

Graham R. Walden

This volume is the first of two volumes that address the most recent ten years (1997-2006) of focus group studies and research literature. Volume one provides coverage of the arts and humanities, social sciences, and the nonmedical sciences, and volume two concentrates on the medical and health sciences. These volumes cover the English-language academic literature (books, chapters in books, journal articles, and significant pamphlets) available in libraries via interlibrary loan and online. A variety of materials are included: instructional guides, handbooks, reference works, textbooks, and academic journal literature. In Focus Groups, Volume I, the following subject disciplines have been considered: in the arts and humanities_linguistics, music, religion, and sports and leisure studies; in the social sciences_anthropology, business, cartography, communication, demography, education, law, library science, political science, psychology, and sociology; and in the non-medical sciences_agriculture, biology, engineering, environmental sciences, and physics. The selected entries have a minimum of four pages, and include 29 books, 50 book chapters, 349 articles, and 10 pamphlets, for a total of 438 entries. An appendix includes the titles of the 245 journals cited, along with the appropriate entry numbers for each. Author and subject indexes provide access to the contents, with the subject index providing access to unique terms. The detailed contents pages are designed to enable the reader to quickly find appropriate entries through the use of extensive and detailed subheadings.

S. Samanta, O. Singh, R. Jain

J. Lakowicz

J. Zaldivar, J. Nielsen, L. Olsson

F. Glover, M. Laguna

From the Publisher: This book explores the meta-heuristics approach called tabu search, which is dramatically changing our ability to solve a hostof problems that stretch over the realms of resource planning,telecommunications, VLSI design, financial analysis, scheduling, spaceplanning, energy distribution, molecular engineering, logistics,pattern classification, flexible manufacturing, waste management,mineral exploration, biomedical analysis, environmental conservationand scores of other problems. The major ideas of tabu search arepresented with examples that show their relevance to multipleapplications. Numerous illustrations and diagrams are used to clarifyprinciples that deserve emphasis, and that have not always been wellunderstood or applied. The book's goal is to provide ''hands-on' knowledge and insight alike, rather than to focus exclusively eitheron computational recipes or on abstract themes. This book is designedto be useful and accessible to researchers and practitioners inmanagement science, industrial engineering, economics, and computerscience. It can appropriately be used as a textbook in a masterscourse or in a doctoral seminar. Because of its emphasis on presentingideas through illustrations and diagrams, and on identifyingassociated practical applications, it can also be used as asupplementary text in upper division undergraduate courses. Finally, there are many more applications of tabu search than canpossibly be covered in a single book, and new ones are emerging everyday. The book's goal is to provide a grounding in the essential ideasof tabu search that will allow readers to create successfulapplications of their own. Along with the essentialideas,understanding of advanced issues is provided, enabling researchers togo beyond today's developments and create the methods of tomorrow.

Katie Brenner, L. You, F. Arnold

P. Kausch

H. Tuomisto, J. T. D. Mattos

Jeong Wook Lee, D. Na, J. Park et al.

Shirong GE, Jing GUO

Deep coal resources with abundant reserves and considerable thermal potential are receiving increased attention in mining engineering, given the accelerating transformation of the global energy structure and the growing demand for clean energy. To address extraction challenges and environmental pressures while ensuring economic feasibility and sustainable development, efforts are made to enable carbon reduction and green transformation under high-efficiency utilization of deep coal resources. A systematic review of “deep coal resource fluidized mining”, “coal chemical mining”, and “coal-based power” informs the introduction of a detonation-generation mining approach and its technical framework. The approach places coal-powder detonation combustion technology at its core and integrates advanced detonation combustion-mechanical/magnetohydrodynamic power generation, forming a detonation-turbine/MHD hybrid power system that supports efficient conversion and clean utilization of coal resources. Four fundamental theories are presented, including the Coal-powder Detonation Energy Release mechanism, the Coupled Coal-powder Detonation-generation Power Scheme, a Full Life Cycle Detonation-power Generation Dynamic Management Mechanism, and the Blasting-electric Power Deep coal mining theory and method. Discussion centers on four key technologies: Stable coal/gas two-phase detonation, detonation model construction and dynamic process optimization, detonation-based power generation efficiency assessment, and comprehensive design for detonation-based coal mining, demonstrating their role in upgrading deep coal mining practices. On this foundation, a systematic engineering strategy is proposed to clarify the synergy between mining processes and the detonation-based power generation mode, highlight safety management and process optimization priorities at each critical stage, and refine the overall detonation-generation pathway for deep coal resource development. This pathway offers valuable insights for establishing a coal-based power system and promoting the clean and efficient utilization of deep coal resources in China.

Wanying Zhang, Jing Wang, Geng Qin et al.

The shipping industry, responsible for transporting 90% of global goods, is a major source of pollution and greenhouse gas (GHGs) emissions. In response to the increasingly stricter global and regional emission control regulations, the maritime industry has adopted various operational and technical measures to improve vessel energy efficiency so as to reduce emissions. However, these measures might not be able to effectively address the core issue of emissions, which arises from a heavy reliance on carbon-intensive energy sources. To reduce the emissions from the whole shipping industry more fundamentally, this review evaluates the viability of five alternative marine fuels — liquefied natural gas (LNG), methanol, ammonia, biofuel, and hydrogen — as potential solutions for maritime decarbonization. This review adopts the systematic search flow (SSF) approach, using iterative search refinement and thematic analysis for a structured synthesis of maritime alternative fuel literature. It first introduces each type of alternative fuel with an emphasis on production methods and sources, which are distinctively categorized by “color.” Following this, a comprehensive comparison of the fuels is presented, focusing on technical feasibility, economic viability, emission reduction capabilities, availability, and safety considerations. The practical application of these fuels is further explored through an analysis of their adoption in operational fleets and new orders, as well as the readiness of port infrastructure to support these changes. This review also examines the role of alternative fuels in the development of green shipping corridors, underscored by an analysis of green shipping finance initiatives. The findings provide valuable insights into the viability of these fuels, supporting the International Maritime Organization (IMO)’s 2050 decarbonization goals and paving the way towards zero emissions in global shipping.

Li Zhao, Jian Chen, Jiaqi Wen et al.

Per- and polyfluoroalkyl substances (PFAS), commonly known as “forever chemicals”, are ubiquitous in surface waters and potentially threaten human health and ecosystems. Despite extensive monitoring efforts, PFAS risk in European surface waters remain poorly understood, as performing PFAS analyses in all surface waters is remarkably challenging. This study developed two machine-learning models to generate the first maps depicting the concentration levels and ecological risks of PFAS in continuous surface waters across 44 European countries, at a 2-km spatial resolution. We estimated that nearly eight thousand individuals were affected by surface waters with PFAS concentrations exceeding the European Drinking Water guideline of 100 ng/L. The prediction maps identified surface waters with high ecological risk and PFAS concentration (>100 ng/L), primarily in Germany, the Netherlands, Portugal, Spain, and Finland. Furthermore, we quantified the distance to the nearest PFAS point sources as the most critical factor (14%–19%) influencing the concentrations and ecological risks of PFAS. Importantly, we determined a threshold distance (4.1–4.9 km) from PFAS point sources, below which PFAS hazards in surface waters could be elevated. Our findings advance the understanding of spatial PFAS pollution in European surface waters and provide a guideline threshold to inform targeted regulatory measures aimed at mitigating PFAS hazards.

Mohammed Saleh Alshaikh

The performance of Organic Solar Cells (OSCs) is intrinsically linked to the molecular, electronic, and structural properties of donor and acceptor materials. This study employs various machine learning techniques, namely the Generalized Regression Neural Network (GRNN), Support Vector Machine (SVM), and Tree Boost, to predict key performance metrics of OSCs, including power conversion efficiency (PCE), short-circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF). The models are trained and evaluated using an experimentally reported dataset compiled by Sahu et al. Correlation analysis demonstrates that material characteristics such as polarizability, bandgap, dipole moment, and charge transfer are statistically associated with OSC performance. The predictive performance of the GRNN model is compared with that of the SVM and Tree Boost models, showing consistently lower prediction errors within the considered dataset. In addition, sensitivity analysis is performed to assess the relative importance of the predictor variables and to examine the influence of kernel functions on GRNN performance. The results indicate that machine learning models, particularly GRNN, can serve as effective data-driven tools for predicting the performance of organic solar cells and for supporting computational screening studies.

Gang Chen, Xin Tang, Baohang Guo et al.

Underwater sensor deployment in military applications requires high precision, yet existing robotic solutions often lack the maneuverability and adaptability required for complex aquatic environments. To address this gap, this study proposes a bio-inspired underwater robot modeled after the marine iguana, which exhibits effective crawling and swimming capabilities. The research aims to develop a compact, multi-functional robot capable of precise sensor deployment and environmental detection. The methodology integrates a biomimetic mechanical design—featuring leg-based crawling, tail-driven swimming, a deployable head mechanism, and buoyancy control—with a multi-sensor control system for navigation and data acquisition. Gait and trajectory planning are optimized using kinematic modeling for both terrestrial and aquatic locomotion. Experimental results demonstrate the robot’s ability to perform accurate underwater sensor deployment, validating its potential for military applications. This work provides a novel approach to underwater deployment robotics, bridging the gap between biological inspiration and functional engineering.

Sobhana Mummaneni, Venkata Chaitanya Satya Ramaraju Mudunuri, Sri Veerabhadra Vikas Bommaganti et al.

A facial recognition system is a biometric security and surveillance system that can identify and monitor individuals in a crowded area. Manually monitoring a crowded environment is a difficult and error-prone task. Therefore, in such contexts, a model that automatically detects and recognises people's faces is needed to improve security. The automation of face recognition brings the benefit of a more efficient and accurate solution. This paper proposes an advanced model that has the ability to detect and recognise faces in dense crowds by using deep learning techniques. Where the input is live video, the process involves splitting the video into frames and each frame is fed into the model. The Multi-Task Cascaded Convolutional Neural Networks (MTCNN) algorithm is used for face detection. It accurately locates faces in frames and images and generates boundaries around the faces as output. The detected faces are then fed as input to a model, where they are compared with data from the database. If a face is recognised, the name of the recognised person is displayed in the boundary box of the frame, otherwise it is displayed that the person is unknown. FaceNet is used for face recognition tasks.

Qiufen LI, Wenjie TIAN, Bo SUN et al.

In the process of mariculture, a large number of toxic and harmful substances such as organic matter, ammonia, and nitrite are produced during the metabolism of cultured organisms and the decomposition of feed residuals. If such maricultural wastewater is discharged without purification treatment, it will aggravate the occurrence of eutrophication in the receiving sea area. Constructed wetlands (CW) have received widespread attention due to their low operating costs, simple maintenance, and management advantages. Using CW to treat maricultural wastewater has great prospects. Nitrogen removal is one of the main tasks of constructed wetlands. The characteristics of high salinity and low C/N of maricultural wastewater result in the unique treatment environment and operating mechanism of CW. The substrate can adsorb nitrogen in the constructed wetlands, and nitrogen-cycling microorganisms such as nitrifying bacteria and denitrifying bacteria can attach to the surface to form biofilms. The selection of suitable substrate materials, in addition to zeolite, cinder, sand, and other commonly used water purification materials, can strengthen water purification. Given the low C/N characteristics of maricultural wastewater, materials with slow-release carbon sources can be selected as the filling substrate of constructed marine wetlands. For example, biological carbon sources such as corncob and wood chips, and polymer materials such as PCL and PLC, have recently been used as substrates to fill constructed wetlands and release carbon sources. Meanwhile, substrates that can drive the autotrophic denitrification process of microorganisms such as sulfur autotrophic, hydrogen autotrophic, and iron autotrophic have also been used as a solution. Plants are an important component of constructed marine wetlands, supporting nitrogen removal in four aspects: Nitrogen absorption, oxygen transport, carbon source secretion, and root enrichment of microorganisms. The high salinity environment determines that the wetland plants should be salt-tolerant, and the screening of salt-tolerant plants is a key step in constructed marine wetlands. Currently, Spartina alterniflora, Suaeda salsa, Salicornia bigelovii, Kandelia candel, and similar plants are chosen as candidate plants for constructed marine wetlands. The selection of plants should also consider local conditions, choosing salt-tolerant plants suitable for growing in the local environment. The nitrogen cycle of microorganisms is the main path of biological nitrogen removal in CWs. Various nitrogen-metabolizing bacteria cooperate and restrict each other in CWs, including autotrophic and heterotrophic bacteria, as well as aerobic and anaerobic bacteria. In the process of nitrogen removal in constructed wetlands, dissolved oxygen (DO) is an important environmental factor affecting the distribution and functioning of nitrogen-removing microorganisms. The relatively high DO in the upper layer of the constructed wetland favors the growth and reproduction of aerobic microorganisms, promoting the traditional nitrification process dominated by AOA, AOB, and NOB. The relatively low DO in the bottom layer is more conducive to the growth and colonization of anoxic and anaerobic microorganisms, favoring anaerobic denitrification, Anammox, and DNRA. The occurrence of Comammox can be driven under low nutrient and low oxygen conditions. These bacteria with nitrogen metabolism functions are distributed in different areas, cooperating and restricting each other, forming a complex nitrogen cycle network. Clarifying the basic path of the nitrogen cycle in seawater constructed wetlands is the fundamental basis for regulating the operating parameters of constructed wetlands. The low C/N of mariculture wastewater is not favorable for denitrification by microorganisms. Carbon sources can be supplemented with additional liquid carbon sources, solid carbon sources, and plant litter. DO is the key control index of constructed marine wetlands. The dissolved oxygen content in constructed wetlands is significantly correlated with the community composition of denitrification microorganisms. Therefore, oxygen supply regulation modes, such as continuous aeration, intermittent aeration, and tidal flow, may be effective measures for mariculture wastewater constructed wetlands to improve the overall nitrogen removal performance of wetlands. Accurate regulation of the oxygen supply mode and oxygen supply in constructed wetlands and optimization of dissolved oxygen distribution in different times and spaces within the system are the development trends of nitrogen removal technology in constructed wetlands in the future. The hydraulic operation conditions of CW play an important role in its nitrogen removal effect. Too high or too low indices will affect the efficiency of nitrogen removal in wetlands. Therefore, the optimal control values of hydraulic retention time (HRT), hydraulic loading rate (HLR), and other hydraulic parameters of constructed wetlands also need to be studied. The hydraulic conditions of constructed wetlands also have a significant impact on plant growth, affecting the purification efficiency of plants. In this paper, recent research progress and perspectives on constructed wetlands for the purification of maricultural wastewater and its biological nitrogen removal process were reviewed from four aspects: Selection of substrate, screening of salt-tolerant plants, nitrogen cycling microorganisms, and operation regulation. It is expected to provide a theoretical basis and support for regulating the actual operation of maricultural wastewater constructed wetlands and improving the technical level of maricultural wastewater treatment.

Jiuwei Zhao, Mi-Kyung Sung, Jae-Heung Park et al.

Abstract Owing to the significant influence of El Niño-Southern Oscillation (ENSO) on global climate, how ENSO events are initiated is an intriguing issue. The North Pacific Oscillation (NPO), a primary atmospheric variability over the midlatitude, is a well-known trigger for ENSO events, but the physical linkage is not yet fully understood. Based on observational analyses, in Part I, we proposed a new mechanism that the NPO-related wave activity flux (WAF) could directly induce the equatorial wind anomalies in both upper and lower levels. In this study, we substantiate the impacts of the WAF on tropical circulations using climate models participating in the Coupled Model Intercomparison Project phases 5 and 6 (CMIP5/6). We found that the intensity of the southward WAF over the central Pacific is a paramount factor resulting in intermodel diversity in simulating the NPO–ENSO linkage. By classifying the models into two groups of strong and weak meridional WAF (MWAF), we reveal that the strong MWAF models simulate stronger upper- and lower-level equatorial winds and precipitation anomalies that facilitate the ENSO in subsequent winter. We also reveal that the magnitude of the MWAF is closely related to the model’s climatological meridional wind and meridional shear of climatological zonal wind, emphasizing the role of systematic bias on the ENSO simulation. A comparison of the MWAF impact and seasonal footprinting mechanism demonstrates the dominant influence of the MWAF in determining the diversity of NPO–ENSO relationships.