Search results for "sites"
showing 10 items of 2851 documents
Alcohol-Selective Oxidation in Water under Mild Conditions via a Novel Approach to Hybrid Composite Photocatalysts
2015
Abstract The oxidation of alcohols to carbonyl compounds in a clean fashion (i.e., with water as a solvent or under solvent‐free conditions, and using O2 or H2O2 as the primary oxidant) is the subject of considerable research efforts. A new approach for the selective oxidation of soluble aromatic alcohols in water under mild conditions via a novel composite photocatalyst has been developed. The catalyst is synthesized by grafting 4‐(4‐(4‐hydroxyphenylimino)cyclohexa‐2,5dienylideneamino)phenol and silver nanoparticles onto the surface of moderately crystalline titanium dioxide. The titanium dioxide‐based composite was first extensively characterized and then employed in the catalytic oxidati…
Ecological impacts of invasive signal crayfish in large boreal lakes
2012
A review of the analytical and numerical modeling of composites
2016
This review article is dedicated to the materials that are made from two or more constituent materials with different physical and/or chemical properties. The focus is on the materials, where the individual components remain separate and distinct within the final structure. The new combined material usually have some additional characteristic properties compared to the individual components, or, in other case, some critical properties of combined material may follow almost equally one of the components. Typically, preferred properties of the new material can be such as strength, porosity, conductivity or cheapness. The ultimate goal of this study is to find methods and tools for achieve adequ…
Recent progress in metal-organic frameworks (MOFs) for CO2 capture at different pressures
2022
Global climate change ensued by the rise in atmospheric CO2 levels is one of the greatest challenges our planet is facing today. This worldwide distress demands technologies that can contribute to our society toward “negative carbon emissions”. Carbon capture and storage (CCS) technologies are in in important role for capturing CO2 from existing emission sources, such as industrial and energy production point sources, before new more prominent modifications to the energy infrastructure can be implemented. Recently, alongside point source capture, direct air capture (DAC) processes have emerged as highly sought-after technologies that are able to capture CO2 from the ambient air. Alongside t…
Influence of PDA Coating on the Structural, Optical and Surface Properties of ZnO Nanostructures
2020
Polydopamine (PDA) is a new biocompatible material, which has prospects in biomedical and sensor applications. Due to functional groups, it can host wide range of biomolecules. ZnO nanostructures are well known templates for optical sensors and biosensors. The combination of ZnO and PDA results in a change of optical properties of ZnO&ndash
"Pamiętam, że...". O społecznej konstrukcji pamięci mieszkańców miast Ziem Zachodnich i Północnych na przykładzie Wrocławia
2017
Celem artykułu jest przedstawienie wątków pamięci społecznej, które z jednej strony opierają się na indywidualnym, potocznym doświadczeniu jednostki, z drugiej umieszczane są w społecznie wynegocjowanych ramach pamięci zbiorowej. Artykuł ten wpisuje się również w dyskusję nad miejscami pamięci i ich możliwą treścią - wykraczającą poza podtrzymujące pamięć zbiorową muzea, pomniki, upamiętniające tablice czy cmentarze - realizowaną w codziennym życiu jednostki. Przedmiotem analiz jest pamięć społeczna mieszkańców Wrocławia, ich konstrukcje światów społecznych opierające się na przestrzeni miasta obciążonej obcą kulturowo „pamięcią nieobecnych”.
How educators commit to enhancing children’s participation in early childhood education pedagogical plans
2022
Background: This is a descriptive study of children’s participation plans in early childhood education (ECE) settings in Finland. The study adopted a multidimensional approach to find out how practices of children’s participation were conceived in pedagogical plans made by ECE staff, representing a focus that is rare in the existing body of research. Aim: Aim of the study was to investigate educators’ commitments to enhancing children’s participation in pedagogical practices in their ECE settings. Setting: Ten centre-based plans for children’s participation composed by ECE staff at ECE centres were selected for the document data in this study. Methods: This study employs the categorisation …
PHOTOOXIDATION BEHAVIOR OF POLYPROPYLENE NANOCOMPOSITES WITH MODIFIED HALLOYSITE
2017
The photooxidation behaviour of polymer nanocomposites depends on the photooxidation of the matrix, but also on the possible interactions with the nanoparticles. In this work, the effect of halloysite modified nanoparticles on the photooxidation of a polypropylene matrix has been investigated.
Polypropylene/polyhedral oligomeric silsesquioxane nanocomposites – study of free volumes, crystallinity degree and mass flow rate
2016
Nanokompozyty polipropylen/poliedryczne oligomeryczne silseskwioksany (PP/POSS) przygotowano metodą mieszania w stanie stopionym polimeru. Wpływ struktury oraz ilości zastosowanych nanonapełniaczy POSS na objętości swobodne w polipropylenie określono z zastosowaniem spektroskopii czasów życia pozytonów (PALS). Ustalono zależności pomiędzy parametrami PALS: czasem życia o-Ps (τ3) i natężeniem (I3) składowej o-Ps oraz wartościami stopnia krystaliczności (Xc ) i masowego wskaźnika szybkości płynięcia (MFR) badanych materiałów. Obecność nanonapełniaczy POSS wpłynęła na liczbę i rozmiary objętości swobodnych w polimerze, co spowodowało zmianę mikrostruktury osnowy polipropylenowej. Wraz ze zwięk…
Nanocomposites with polyhedral oligomeric silesquioxane nanofillers - characterization of morphology, thermal and mechanical properties
2016
High-density polyethylene nanocomposites with hydroxy-hepta(iso-butyl)-octasilsesquioxane (POSS-(i-Bu)7OH) and hydroxy-hepta(iso-octyl)-octasilsesquioxane (POSS-(i-Oct)7OH) as nanofillers were prepared by melt blending. The morphological, thermal and mechanical properties as well as processability of obtained nanocomposites were characterized. POSS nanofillers were homogenously dispersed in polymeric matrix. High compatibility between nanofiller and polymer induced enhanced thermal stability, Charpy impact strength and melt flow rate for composite materials. POSS particles acted also as a nucleating agent for polyethylene crystallization in the nanocomposite.