Books published by Mdpi AG

The investigation of new memory schemes, neural networks, computer systems and many other improved electronic devices is very important for future generation's electronic circuits and for their widespread application in all the areas of industry. In this aspect the analysis of new efficient and advanced electronic elements and circuits is an essential field of the highly developed electrical and electronic engineering. The resistance-switching phenomenon, observed in many amorphous oxides has been investigated since 1970 and it is a promising technology for constructing new electronic memories. It has been established that such oxide materials have the ability for changing their conductance in accordance to the applied voltage and memorizing their state for a long-time interval. Similar behaviour has been predicted for the memristor element by Leon Chua in 1971. The memristor is proposed in accordance to symmetry considerations and the relationships between the four basic electric quantities - electric current i, voltage v, charge q and magnetic flux Ψ. The memristor is an essential passive one-port element together with the resistor, inductor, and capacitor. The Williams HP research group has made a link between resistive switching devices, and the memristor proposed by Chua. A number of scientific papers related to memristors and memristor devices have been issued and several memristor models have been proposed. The memristor is a highly nonlinear component. It relates the electric charge q and the flux linkage, expressed as a time integral of the voltage. The memristor element has the important capability for remembering the electric charge passed through its cross-section and its respective resistance, when the electrical signals are switched off. Due to its nano-scale dimensions, non-volatility and memorizing properties, the memristor is a sound potential candidate for application in computer high-density memories, artificial neural networks and in many other electronic devices.

Starting from a kinase of interest, AMP-activated protein kinase (AMPK) has gone far beyond an average biomolecule. Being expressed in all mammalian cell types and probably having a counterpart in every eukaryotic cell, AMPK has attracted interest in virtually all areas of biological research. Structural and biophysical insights have greatly contributed to a molecular understanding of this kinase. From good old protein biochemistry to modern approaches, such as systems biology and advanced microscopy, all disciplines have provided important information. Thus, multiple links to cellular events and subcellular localizations have been established. Moreover, the crucial involvement of AMPK in human health and disease has been evidenced. AMPK accordingly has moved from an interesting enzyme to a pharmacological target. However, despite our extensive current knowledge about AMPK, the growing community is busier than ever. This book provides a snapshot of recent and current AMPK research with an emphasis on work providing molecular insight, including but not limited to novel physiological and pathological functions, or regulatory mechanisms. Up-to-date reviews and research articles are included.

Globalization and telecoupling are enhancing the complexity of the coupled socio-ecological system constituted by the interaction between the global ecosphere and the anthroposphere. As a result, the demand for tools to identify transformative innovations, assess future risks, and support precautionary decisions for sustainability is growing by the day in business and politics. Scenarios are a means of simplification, reducing the real-world complexity to a limited number of essential factors to analyze their interactions and support policy formulation, with indicators as communication and monitoring tools.In particular, in a time of “fake news” and “alternative truths” a critical reflection amongst producers and users of scenarios and indicators is overdue—the capability for critical self-reflection is what distinguishes science from pseudo-science, and is a condition of trust.The authors of this book test established measurement and modeling approaches against new challenges, assess the weaknesses of prevailing innovation theories and the political-ideological embedment of archetypical scenarios, highlight deficits in taking the physical basics into account, and the need to understand global interaction and the stepwise process of energy transitions, point out technical as well as conceptual weaknesses in data collection, harmonization and indicator generation, always with a view to solving problems.

The subject of this book is “Biofuel and Bioenergy Technology”. It aims to publish high-quality review and research papers, addressing recent advances in biofuel and bioenergy. State-of-the-art studies of advanced techniques of biorefinery for biofuel production are also included. Research involving experimental studies, recent developments, and novel and emerging technologies in this field are covered. This book contains twenty-seven technical papers which cover diversified biofuel and bioenergy technology-related research that have shown critical results and contributed significant findings to the fields of biomass processing, pyrolysis, bio-oil and its emulsification; transesterification and biodiesel, gasification and syngas, fermentation and biogas/methane, bioethanol and alcohol-based fuels, solid fuel and biochar, and microbial fuel cell and power generation development. The published contents relate to the most important techniques and analyses applied in the biofuel and bioenergy technology.

This book contains the successful invited submissions to a Special Issue of Symmetry on the subject of “Graph Theory”.Although symmetry has always played an important role in Graph Theory, in recent years, this role has increased significantly in several branches of this field, including but not limited to Gromov hyperbolic graphs, the metric dimension of graphs, domination theory, and topological indices. This Special Issue includes contributions addressing new results on these topics, both from a theoretical and an applied point of view.

Information management is a common paradigm in modern decision-making. A wide range of decision-making techniques have been proposed in the literature to model complex business and engineering processes. In this Special Issue, 16 selected and peer-reviewed original research articles contribute to business information management in various current real-world problems by proposing crisp or uncertain multiple-criteria decision-making (MCDM) models and techniques, mostly including multi-attribute decision-making (MADM) approaches, in addition to a single paper proposing an interactive multi-objective decision-making (MODM) approach. Particular attention is devoted to information aggregation operators—65% of papers dealt with this item. The topics of this Special Issue gained attention in Europe and Asia. A total of 48 authors from seven countries contributed to this Issue. The papers are mainly concentrated in three application areas: supplier selection and rational order allocation, the evaluation and selection of goods or facilities, and personnel selection/partner selection. A number of new approaches are proposed that are expected to attract great interest from the research community.

Following the tremendous reception of our first volume on topological groups called "Topological Groups: Yesterday, Today, and Tomorrow", we now present our second volume. Like the first volume, this collection contains articles by some of the best scholars in the world on topological groups. A feature of the first volume was surveys, and we continue that tradition in this volume with three new surveys. These surveys are of interest not only to the expert but also to those who are less experienced. Particularly exciting to active researchers, especially young researchers, is the inclusion of over three dozen open questions. This volume consists of 11 papers containing many new and interesting results and examples across the spectrum of topological group theory and related topics. Well-known researchers who contributed to this volume include Taras Banakh, Michael Megrelishvili, Sidney A. Morris, Saharon Shelah, George A. Willis, O'lga V. Sipacheva, and Stephen Wagner.

Fossil fuels leaded the 21st century industrial revolution but caused some critical problems such as exhaustion of resources and global warming. Also, current power plants require too much high cost and long time for establishment and facilities to provide electricity. Thus, developing new power production systems with environmental friendliness and low-cost is critical global needs. There are some emerging energy harvesting technologies such as thermoelectric, piezoelectric, and triboelectric nanogenerators, which have great advantages on eco-friendly low-cost materials, simple fabrication, and various operating sources. Since the introduction of various energy harvesting technologies, many novel designs and applications as power suppliers and physical sensors in the world have been demonstrated based on their unique advantages. In this Special Issue, we would like to address and share basic approaches, new designs, and industrial applications related to thermoelectric, piezoelectric, and triboelectric devices which are on-going in Korea. With this Special Issue, we aim to promote fundamental understanding and to find novel ways to achieve industrial product manufacturing for energy harvesters.

The chemistry of silicon has always been a field of major concern due to its proximity to carbon on the periodic table. From the molecular chemist’s viewpoint, one of the most interesting differences between carbon and silicon is their divergent coordination behavior. In fact, silicon is prone to form hyper-coordinate organosilicon complexes, and, as conveyed by reports in the literature, highly sophisticated ligand systems are required to furnish low-coordinate organosilicon complexes. Tremendous progress in experimental, as well as computational, techniques has granted synthetic access to a broad range of coordination numbers for silicon, and the scientific endeavor, which was ongoing for decades, was rewarded with landmark discoveries in the field of organosilicon chemistry. Molecular congeners of silicon(0), as well as silicon oxides, were unveiled, and the prominent group 14 metalloid proved its applicability in homogenous catalysis as a supportive ligand or even as a center of catalytic activity. This book focuses on the most recent advances in the coordination chemistry of silicon with transition metals as well as main group elements, including the stabilization of low-valent silicon species through the coordination of electron donor ligands. Therefore, this book is associated with the development of novel synthetic methodologies, structural elucidations, bonding analysis, and also possible applications in catalysis or chemical transformations using related organosilicon compounds.

Understanding of the role of turbulence in controlling transport processes is of paramount importance for the preservation and protection of aquatic ecosystems, the minimization of the deleterious consequences of anthropogenic activity, and the successful sustainable development of river and maritime areas. In this context, the present Special Issue collects 15 papers which provide a representation of the present understanding of turbulent processes and their effects in river and maritime environments. The presented collection of papers is not exhaustive, but it highlights the key priority areas and knowledge gaps in this field of research.The published papers present the state-of-the-art knowledge of complex environmental flows which are useful for researchers and practitioners. The paper contents are an overview of some recent topics of research and an exposure of the current and future challenges associated with these topics.

Currently, the use of computational fluid dynamics (CFD) solutions is considered as the state-of-the-art in the modeling of unsteady nonlinear flow physics and offers an early and improved understanding of air vehicle aerodynamics and stability and control characteristics. This Special Issue covers recent computational efforts on simulation of aerospace vehicles including fighter aircraft, rotorcraft, propeller driven vehicles, unmanned vehicle, projectiles, and air drop configurations. The complex flow physics of these configurations pose significant challenges in CFD modeling. Some of these challenges include prediction of vortical flows and shock waves, rapid maneuvering aircraft with fast moving control surfaces, and interactions between propellers and wing, fluid and structure, boundary layer and shock waves.Additional topic of interest in this Special Issue is the use of CFD tools in aircraft design and flight mechanics. The problem with these applications is the computational cost involved, particularly if this is viewed as a brute-force calculation of vehicle’s aerodynamics through its flight envelope. To make progress in routinely using of CFD in aircraft design, methods based on sampling, model updating and system identification should be considered.

The intention of the Special Issue "Biological and Biogenic Crystallization" was to create an international platform aimed at covering a broad field of results involving the crystallization of biological molecules, including virus and protein crystallization, biogenic crystallization including physiological and pathological crystallization taking place in living organisms (human beings, animals, plants, bacteria, etc.), and bio-inspired crystallization. Despite many years of research on biological and biogenic crystals, there are still open questions as well as hot and timely topics. This Special Issue contains seven articles that present a cross-section of the current research activities in the of field of biological and biogenic crystals. The authors of the presented articles prove the vibrant and topical nature of this field. We hope that this Special Issue will serve as a source of inspiration for future investigations, and will be useful for scientists and researchers who work on the exploration of biological and biogenic crystals.

Quantitative land remote sensing has recently advanced dramatically, particularly in China. It has been largely driven by vast governmental investment, the availability of a huge amount of Chinese satellite data, geospatial information requirements for addressing pressing environmental issues and other societal benefits. Many individuals have also fostered and made great contributions to its development, and Prof. Xiaowen Li was one of these leading figures. This book is published in memory of Prof. Li. The papers collected in this book cover topics from surface reflectance simulation, inversion algorithm and estimation of variables, to applications in optical, thermal, Lidar and microwave remote sensing. The wide range of variables include directional reflectance, chlorophyll fluorescence, aerosol optical depth, incident solar radiation, albedo, surface temperature, upward longwave radiation, leaf area index, fractional vegetation cover, forest biomass, precipitation, evapotranspiration, freeze/thaw snow cover, vegetation productivity, phenology and biodiversity indicators. They clearly reflect the current level of research in this area. This book constitutes an excellent reference suitable for upper-level undergraduate students, graduate students and professionals in remote sensing.

Quantitative land remote sensing has recently advanced dramatically, particularly in China. It has been largely driven by vast governmental investment, the availability of a huge amount of Chinese satellite data, geospatial information requirements for addressing pressing environmental issues and other societal benefits. Many individuals have also fostered and made great contributions to its development, and Prof. Xiaowen Li was one of these leading figures. This book is published in memory of Prof. Li. The papers collected in this book cover topics from surface reflectance simulation, inversion algorithm and estimation of variables, to applications in optical, thermal, Lidar and microwave remote sensing. The wide range of variables include directional reflectance, chlorophyll fluorescence, aerosol optical depth, incident solar radiation, albedo, surface temperature, upward longwave radiation, leaf area index, fractional vegetation cover, forest biomass, precipitation, evapotranspiration, freeze/thaw snow cover, vegetation productivity, phenology and biodiversity indicators. They clearly reflect the current level of research in this area. This book constitutes an excellent reference suitable for upper-level undergraduate students, graduate students and professionals in remote sensing.

Entropy theory has wide applications to a range of problems in the fields of environmental and water engineering, including river hydraulic geometry, fluvial hydraulics, water monitoring network design, river flow forecasting, floods and droughts, river network analysis, infiltration, soil moisture, sediment transport, surface water and groundwater quality modeling, ecosystems modeling, water distribution networks, environmental and water resources management, and parameter estimation. Such applications have used several different entropy formulations, such as Shannon, Tsallis, Rényi, Burg, Kolmogorov, Kapur, configurational, and relative entropies, which can be derived in time, space, or frequency domains. More recently, entropy-based concepts have been coupled with other theories, including copula and wavelets, to study various issues associated with environmental and water resources systems. Recent studies indicate the enormous scope and potential of entropy theory in advancing research in the fields of environmental and water engineering, including establishing and explaining physical connections between theory and reality.The objective of this Special Issue is to provide a platform for compiling important recent and current research on the applications of entropy theory in environmental and water engineering. The contributions to this Special Issue have addressed many aspects associated with entropy theory applications and have shown the enormous scope and potential of entropy theory in advancing research in the fields of environmental and water engineering.

The 2018 MDPI Writing Prize invited early stage researchers who are not native English speakers to write on the subject of "the global benefits of open research". Six prizes were awarded, however there were many more entries. This book collates many of those entries and contains inspiring, thought-provoking and original viewpoints of open science through the eyes of those conducting research on a daily basis