Subject:
All Disciplines Arts & Humanities Biology & Life Sciences Business & Economics Chemistry & Materials Science Computer Science & Mathematics Engineering Environmental & Earth Sciences Medicine & Pharmacology Physical Sciences Public Health & Healthcare Social Sciences
Sort:
Hottest Latest Alphabetical (A-Z) Alphabetical (Z-A)
Type:
All Topic Review Biography
Topic Review
Surface Activation of Polytetrafluoroethylene
Fluorinated polymers are renowned for their chemical inertness and thus poor wettability and adhesion of various coatings. Apart from chemical methods employing somewhat toxic primers, gaseous plasma treatment is a popular method for the modification of surface properties. Different authors have used different plasmas, and the resultant surface finish spans between super-hydrophobic and super-hydrophilic character.
  • 733
  • 19 Oct 2020
Topic Review
Biomass Wastes
Biomass wastes are abundant around us. They are renewable and inexpensive. Product manufacturing from renewable resources has caught increasing interest recently. Activated carbon preparation from biomass resources, including various trees, leaves, plant roots, fruit peels, and grasses, is a good example. In this paper, an overview of activated carbon production from biomass resources will be given. 
  • 733
  • 13 May 2021
Topic Review
Recycling and Use of Plastic Waste
Research into plastic recycling is rapidly increasing as ocean and land pollution and ecosystem degradation from plastic waste is becoming a serious concern. In this study, we conducted a systematic review on emerging research topics, which were selected from 35,519 studies on plastic recycling by bibliometrics analysis. Our results show that research on the biodegradability of plastics, bioplastics, life cycle assessment, recycling of electrical and electronic equipment waste, and the use of recycled plastics in construction has increased rapidly in recent years, particularly since 2016. Especially, biodegradability is the most emerging topic with the average year of publication being 2018. Our key finding is that many research area is led by developed countries, while the use of recycled plastics in the construction sector is being actively explored in developing countries. Based on our results, we discuss two types of recycling systems: responsible recycling in the country where plastic waste is generated and promoting recycling through the international division of labor between developed and developing countries. We discuss the advantages and disadvantages of both approaches and propose necessary measures for sustainable and responsible production and consumption of plastics such as waste traceability system and technology transfer between developed and developing countries.    
  • 732
  • 03 Jan 2023
Topic Review
Sensing ability of ferroelectric oxide nanowires grown in nanopores
Nanowires of ferroelectric potassium niobate were grown by filling nanoporous templates of both sides opened anodic aluminum oxide (AAO) through radiofrequency vacuum sputtering for multisensor fabrication. The precise geometrical ordering of the AAO matrix led to a well-defined single-axis oriented wire-shaped material inside the pores. The sensing abilities of the samples were studied and analyzed in terms of piezoelectric and pyroelectric response and the results were compared for different lengths of the nanopores (nanotubes)—1.3 µm, 6.3 µm, and 10 µm. Based on scanning electron microscopy, elemental and microstructural analyses, as well as electrical measurements at bending and heating, the overall sensing performance of the devices was estimated. It was found that the produced membrane-type elements, consisting of potassium niobate grown in AAO template exhibited excellent piezoelectric response due to the increased specific area as compared to non-structured films, and could be further enhanced with the length of the nanowires. The piezoelectric voltage increased linearly with 16 mV per micrometer of nanowire’s length. At the same time, the pyroelectric voltage was found to be less sensitive to the length of the nanowires, changing its value at 400 nV/µm. This paper provides a simple and low-cost approach for nanostructuring ferroelectric oxides with multi-sensing application and serves as a base for further optimization of template-based nanostructured devices.
  • 732
  • 29 Oct 2020
Topic Review
Principles of Prototropic Equilibria
Prototropic tautomers always differ by the positions of labile proton(s) and π-electrons. The number of possible tautomeric forms is an internal property of the tautomeric molecule. It is a consequence of the number of labile protons and the number of conjugated tautomeric sites.
  • 732
  • 01 Nov 2023
Topic Review
The Assembly of PPTA Nanofibers and the Applications
Poly (p-phenylene terephthalamide) (PPTA) is one kind of lyotropic liquid crystal polymer. Kevlar fibers made from PPTA is widely used in many fields due to the superior mechanical properties resulted from highly oriented macromolecular structure. However, the “infusible and insoluble” characteristic of PPTA gives rise to its poor processability, which limits its scope of application. The strong interactions and orientation characteristic of aromatic amide segments make PPTA attractive in the field of self-assembly. The chemical derivations have proved an effective way to modify the molecular structure of PPTA to improve its solubility and amphiphilicity, which resulted in different liquid crystal behaviors or supramolecular aggregates, but the modification of PPTA is usually complex and difficult. Alternatively, higher order all-PPTA structures have also been realized through the controllable hierarchical self-assembly of PPTA from the polymerization process to the formation of macroscopic products. It briefly introduces the self-assembly methods of PPTA based materials in recent years, and focuses on the polymerization-induced PPTA nanofibers which can be further fabricated into different macroscopic architectures when other self-assembly methods are combined. This monomer-started hierarchical self-assembly strategy evokes the feasible processing of PPTA, and enriches the diversity of product, which is expected to be expanded to other liquid crystal polymers.
  • 732
  • 20 Jul 2022
Topic Review Peer Reviewed
Solid Lipid Nanoparticles
Solid lipid nanoparticles (SLNs) are produced from physiologically biocompatible lipids. They have been proven to improve solubility, cellular uptake, and stability, reduce enzyme degradation, and prolong the circulation time of various drugs. SLNs have been applied in the oral, parenteral, transdermal, intranasal, ocular, and pulmonary drug delivery of different drugs, with enhanced safety, bioavailability, and overall therapeutic effects. In this entry, the authors summarize the primary features of SLNs, methods to prepare SLNs, and recent applications of SLNs in drug delivery. Owing to their advantages, SLNs are potential drug delivery systems to improve the management of various diseases and will, soon, be available for clinical use. 
  • 732
  • 24 May 2022
Topic Review
Ketogenic Diet in Cancer Prevention/Therapy
The ketogenic diet (KD) has recently emerged as a metabolic therapy in cancer treatment, targeting cancer cell metabolism rather than a conventional dietary approach. The ketogenic diet (KD), a high-fat and very-low-carbohydrate with adequate amounts of protein, has shown antitumor effects by reducing energy supplies to cells. This low energy supply inhibits tumor growth, explaining the ketogenic diet’s therapeutic mechanisms in cancer treatment.
  • 732
  • 12 Jul 2021
Topic Review
Cutaneous Flavonoid Delivery System
Flavonoids are one of the vital classes of natural polyphenolic compounds abundantly found in plants. Due to their wide range of therapeutic properties, which include antioxidant, anti-inflammatory, photoprotective, and depigmentation effects, flavonoids have been demonstrated to be promising agents in the treatment of several skin disorders. However, their lipophilic nature and poor water solubility invariably lead to limited oral bioavailability. In addition, they are rapidly degraded and metabolized in the human body, hindering their potential contribution to the prevention and treatment of many disorders. Thus, to overcome these challenges, several cutaneous delivery systems have been extensively studied. Topical drug delivery besides offering an alternative administration route also ensures a sustained release of the active compound at the desired site of action. Incorporation into lipid or polymer-based nanoparticles appears to be a highly effective approach for cutaneous delivery of flavonoids with good encapsulation potential and reduced toxicity.
  • 731
  • 22 Apr 2022
Topic Review
Plasma Electrolytic Oxidation Coating
Plasma electrolytic oxidation (PEO) is an effective surface modification method for producing ceramic oxide layers on metals and their alloys. Although inorganic electrolytes are widely used in PEO, the organic additives have received considerable interest in the last decade due to their roles in improving the final voltage and controlling spark discharging, which lead to significant improvements in the performance of the obtained coatings. 
  • 731
  • 30 Mar 2021
  • Page
  • of
  • 465
Featured Entry Collections
>>

Featured Books

>>
Encyclopedia of Social Sciences
Encyclopedia of COVID-19
Encyclopedia of Fungi
Encyclopedia of Digital Society, Industry 5.0 and Smart City
ScholarVision Creations
Feedback