Investigating the Impact of Shading Effect on the Characteristics of a Large-Scale Grid-Connected PV Power Plant in Northwest China

Northwest China is an ideal region for large-scale grid-connected PV system installation due to its abundant solar radiation and vast areas. For grid-connected PV systems in this region, one of the key issues is how to reduce the shading effect as much as possible to maximize their power generation. In this paper, a shading simulation model for PV modules is established and its reliability is verified under the standard testing condition (STC) in laboratory. Based on the investigation result of a 20 MWp grid-connected PV plant in northwest China, the typical shading phenomena are classified and analyzed individually, such as power distribution buildings shading and wire poles shading, plants and birds droppings shading, and front-row PV arrays shading. A series of experiments is also conducted on-site to evaluate and compare the impacts of different typical shading forms. Finally, some feasible solutions are proposed to avoid or reduce the shading effect of PV system during operation in such region

Advanced functional chitosan-based nanocomposite materials for performance-demanding applications

Chitosan holds great promise for demanding applications such as functional packing and biomedical uses. There has been a notable increase in interest in combining chitosan or its derivatives with other polymers and nanofillers to achieve synergistic effects. Remarkable progress has been made through polymer molecular design and iterative nanotechnology in the development of chitosan-based nanocomposite materials tailored for high-performance applications. This review focuses on strategies to develop chitosan-based materials, highlighting the advantages and disadvantages of chitosan modification and critically evaluating various fabrication methods. Following a brief introduction to various nanofillers and their functionalization, this review discusses the functional properties (e.g., mechanical, thermal, water resistance, gas-barrier, stimulus-response, shape memory, biological, electrochemical, corrosion-protection, antifouling, and abruption/desorption) of various chitosan-based nanocomposite systems. It then highlights the emerging and potential applications of chitosan-based nanocomposites in various fields such as functional packaging, biomedicine, 3D bioprinting, sensing and wearable devices, environmental remediation, and chemical engineering. Moreover, we explore the factors that hinder the commercialization of chitosan-based nanocomposites. Our review not only surveys recent advancements in engineering sophisticated functional chitosan-based nanocomposite materials, customized for a diverse array of applications, but also offers insights into the future formulation of multifaceted chitosan-based nanocomposites, poised to tackle the distinct demands and hurdles encountered in burgeoning applications

Polysaccharide–dextrin thickened fluids for individuals with dysphagia:Recent advances in flow behaviors and swallowing assessment methods

The global aging population has brought about a pressing health concern: dysphagia. To effectively address this issue, we must develop specialized diets, such as thickened fluids made with polysaccharide–dextrin (e.g., water, milk, juices, and soups), which are crucial for managing swallowing-related problems like aspiration and choking for people with dysphagia. Understanding the flow behaviors of these thickened fluids is paramount, and it enables us to establish methods for evaluating their suitability for individuals with dysphagia. This review focuses on the shear and extensional flow properties (e.g., viscosity, yield stress, and viscoelasticity) and tribology (e.g., coefficient of friction) of polysaccharide–dextrin-based thickened fluids and highlights how dextrin inclusion influences fluid flow behaviors considering molecular interactions and chain dynamics. The flow behaviors can be integrated into the development of diverse evaluation methods that assess aspects such as flow velocity, risk of aspiration, and remaining fluid volume. In this context, the key in-vivo (e.g., clinical examination and animal model), in-vitro (e.g., the Cambridge Throat), and in-silico (e.g., Hamiltonian moving particles semi-implicit) evaluation methods are summarized. In addition, we explore the potential for establishing realistic assessment methods to evaluate the swallowing performance of thickened fluids, offering promising prospects for the future

Biofunctional chitosan–biopolymer composites for biomedical applications

In light of escalating biomedical demands across diverse diseases, there arises a pressing need for the development of sophisticated biocompatible materials exhibiting augmented biological functionality. Chitosan, a cationic polyelectrolyte copolymer of natural origin, distinguishes itself through its extraordinary biological properties, positioning it as a promising starting material to develop versatile biomedical materials. Tremendous attention has been directed towards the creation of high-performance biocomposites, achieved through the strategic manipulation of chitosan’s structure or its derivative, along with the amalgamation of other biopolymers. This comprehensive review intricately explores recent advancements in chitosan-based biofunctional materials, delving into formulations involving various biopolymers including polysaccharides and proteins. It places specific emphasis on the progress in chitosan chemistry and materials development, encompassing particles, hydrogels, aerogels, membranes, films, and sponges. Also, this review critically evaluates the development and functional properties of biofunctional chitosan–biopolymer composite materials, spotlighting interactions, both dynamic covalent and noncovalent, and their pivotal roles in materials formation. These interactions may either be inherent or realized through chemical modification such as “Click” chemistry, polymer grafts, mussel-inspired chemistry, and selective oxidation. Furthermore, the text illustrates the current and potential biomedical applications of these biofunctional composite materials, spanning from wound dressing to tissue engineering (skin, bone, cartilage, and nerve), the controlled release and targeted delivery of drugs/bioactive compounds, biosensing, and 3D printing. Additionally, it addresses critical challenges within the field, posits potential solutions, and provides a forward-looking perspective on the future directions of functional biomaterials and design strategies

Advanced Geological Prediction

Due to the particularity of the tunnel project, it is difficult to find out the exact geological conditions of the tunnel body during the survey stage. Once it encounters unfavorable geological bodies such as faults, fracture zones, and karst, it will bring great challenges to the construction and will easily cause major problems, economic losses, and casualties. Therefore, it is necessary to carry out geological forecast work in the tunnel construction process, which is of great significance for tunnel safety construction and avoiding major disaster accident losses. This lecture mainly introduces the commonly used methods of geological forecast in tunnel construction, the design principles, and contents of geological forecast and combines typical cases to show the implementation process of comprehensive geological forecast. Finally, the development direction of geological forecast theory, method, and technology is carried out. Prospects provide a useful reference for promoting the development of geological forecast of tunnels

GeoCamera: Telling Stories in Geographic Visualizations with Camera Movements

In geographic data videos, camera movements are frequently used and combined to present information from multiple perspectives. However, creating and editing camera movements requires significant time and professional skills. This work aims to lower the barrier of crafting diverse camera movements for geographic data videos. First, we analyze a corpus of 66 geographic data videos and derive a design space of camera movements with a dimension for geospatial targets and one for narrative purposes. Based on the design space, we propose a set of adaptive camera shots and further develop an interactive tool called GeoCamera. This interactive tool allows users to flexibly design camera movements for geographic visualizations. We verify the expressiveness of our tool through case studies and evaluate its usability with a user study. The participants find that the tool facilitates the design of camera movements.Comment: 15 pages. Published as a conference paper at the ACM Conference on Human Factors in Computing Systems (CHI) 202

Plasticized starch/agar composite films : processing, morphology, structure, mechanical properties and surface hydrophilicity

Natural biopolymers, which are renewable, widely available, biodegradable, and biocompatible, have attracted huge interest in the development of biocomposite materials. Herein, formulation–property relationships for starch/agar composite films were investigated. First, rapid visco analysis was used to confirm the conditions needed for their gelation and to prepare filmogenic solutions. All the original crystalline and/or lamellar structures of starch and agar were destroyed, and films with cohesive and compact structures were formed, as shown by SEM, XRD, and SAXS. All the plasticized films were predominantly amorphous, and the polymorphs of the composite films were closer to that of the agar-only film. FTIR results suggest that the incorporation of agar restricted starch chain interaction and rearrangement. The addition of agar to starch increased both tensile strength and elongation at break, but the improvements were insignificant after the agar content was over 50 wt.%. Contact angle results indicate that compared with the other samples, the 4:6 (wt./wt.) starch/agar film was less hydrophilic. Thus, this work shows that agar dominates the structure and properties of starch/agar composites, and the best properties can be obtained with a certain starch/agar ratio. Such composite polysaccharide films with tailored mechanical properties and surface hydrophilicity could be useful in biodegradable packaging and biomedical applications (wound dressing and tissue scaffolding)

Starch-based food matrices containing protein : recent understanding of morphology, structure, and properties

Starches and proteins are two major types of biopolymer components, especially in many flour (starch)-based foods consumed worldwide, which provide energy and nutrition needed by the human body. In many such starch-based matrices (the main structural component of such foods), proteins and their interactions with starches greatly influence the matrix structure and properties. Studying the different roles played by proteins (endogenous and exogenous) in various starch-based food systems can provide a frame of reference for the design and production of improved starch-based food products with tailored properties and desirable nutritional functions. Scope and approach Significant efforts have recently been made to tailor the morphology, structure, and properties of many starch-based food systems, and thus to design various starch-based food products with satisfactory attributes. This review surveys the latest literature on starch-based matrices containing proteins. Discussed are the influences of proteins and their interactions with starches on the morphologies and structures (e.g. short- and long-range orders) of starch-based matrices, as well as on their pasting, thermal, rheological, textural, sensory, and digestive properties. Also, current understandings of structure–property links are presented, along with their implications on the production of various starchy foods (e.g. pastas, breads, cakes, and biscuits), including gluten-free versions. Key findings and conclusions Proteins in many starchy food matrices can encapsulate the starch phase (or be adsorbed on its surfaces) on a micron scale, and thereby interact with starch chains via both non-covalent (e.g. hydrogen bonding, hydrophobic, and electrostatic) and covalent bonds (e.g. via Maillard reactions). These facts and protein features (e.g. hydration and gelation abilities) can play major roles in inhibiting starch retrogradation (the reassembly of cooked starch chains into ordered structures) and in regulating various other properties of such starch-based matrices, including viscosity, transition temperatures, moduli, hardness, sensory, digestibility, and shelf-life. Despite the fact that the current literature presents considerable information on the structure–property relationships of many different starch-based matrices and their applications in the processing of various starchy foods (e.g. pastas, noodles, and biscuits), it is still highly necessary to define more comprehensive correlations among starch–protein interactions, starch-protein matrix structures, and the resulting properties of such food products