Search results for "dioxide"
showing 10 items of 1250 documents
Toward Sustainable PLA-Based Multilayer Complexes with Improved Barrier Properties
2019
Poly(lactic acid) or PLA is currently considered as one of the most promising substitutes of conventional plastics, with low environmental impact, especially for food packaging applications. Nevertheless, some drawbacks, such as high permeability to oxygen, are still limiting its industrial applications. The objective of this study was to highly increase the oxygen barrier performance of PLA without compromising its sustainable nature and following the principles of circular economy perspective. Coproducts coming from mill industries, such as wheat gluten proteins (WG), were used to produce PLA-WG-PLA multilayer complexes with improved barrier performance. Different technologies of industri…
Modification of PVDF nanoparticles by controlled free radical graft copolymerization in supercritical carbon dioxide
2014
PVDF (polyvinylidenefluoride) membranes are widely used in microfiltration (MF) and ultrafiltration (UF) due to their excellent processability, chemical resistance, well-controlled porosity, and good thermal properties [1]. Moreover this polymer is also frequently adopted in bio-medical devices owing to its good biocompatibility [2]. On the other hand, the use of PVDF membranes in biomedical applications is limited to some extent by the hydrophobicity of their exposed area, which mainly arises from the nature of the pore surface. Prompted by these considerations in the present work we have studied the modification of PVDF nanoparticles with hydroxyethylmethacrylate (HEMA) thus obtaining a m…
Badania parametrów jakości powietrza w salach dydaktycznych
2016
Zamieszczono wyniki badań parametrów jakości powietrza w pomieszczeniach dydaktycznych różnej wielkości. W pomieszczeniach, w których realizowany jest proces dydaktyczny z udziałem dużych grup studentów, powinien być zapewniony odpowiedni komfort klimatyczny,na który mają wpływ przede wszystkim: temperatura oraz wilgotność powietrza, jakość fizyczna i biologiczna powietrza, koncentracja CO2. W wyniku przeprowadzonych analiz wykazano, iż w pomieszczeniach dydaktycznych nie powinno się stosować wentylacji grawitacyjnej. Na podstawie przeprowadzonych badań wyznaczono współczynniki emisji CO2 przez studentów umożliwiające określenie parametrów pracy systemu wentylacji gwarantujące zapewnienie j…
Optimization of carbon dioxide concentration in the didactic rooms by the regulation of ventilation
2016
W artykule zamieszczono wyniki badań parametrów powietrza w pomieszczeniach dydaktycznych różnej wielkości. W pomieszczeniach, w których realizowany jest proces dydaktyczny z udziałem dużych grup studentów, powinien byæ zapewniony odpowiedni komfort klimatyczny, na który mają wpływ przede wszystkim: temperatura oraz wilgotność powietrza, jakość fizyczna fizyczna i biologiczna powietrza, koncentracja CO2. W wyniku przeprowadzonych analiz wykazano, iż w pomieszczeniach dydaktycznych wentylacja grawitacyjna nie powinna być wykorzystywana. Po modernizacji pomieszczeń i zainstalowaniu w systemach wentylacji wentylatorów wyciągowych dokonano pomiarów, na podstawie których wyznaczono współczynniki…
Photocycle of point defects in highly- and weakly-germanium doped silica revealed by transient absorption measurements with femtosecond tunable pump.
2022
AbstractWe report pump-probe transient absorption measurements addressing the photocycle of the Germanium lone pair center (GLPC) point defect with an unprecedented time resolution. The GLPC is a model point defect with a simple and well-understood electronic structure, highly relevant for several applications. Therefore, a full explanation of its photocycle is fundamental to understand the relaxation mechanisms of such molecular-like systems in solid state. The experiment, carried out exciting the sample resonantly with the ultraviolet (UV) GLPC absorption band peaked at 5.1 eV, gave us the possibility to follow the defect excitation-relaxation dynamics from the femto-picosecond to the nan…
Husk Energy Supply Systems for Sunflower Oil Mills
2020
Together with solar, wind, and hydro renewable energy sources (RES), biomass constitutes an integral part of the high-renewables electricity systems. Considerable feedstocks for electricity generation are process-based residues. Ukraine is the world leader in sunflower seed production, therefore, husk (a by-product of oil production) is a promising biofuel for combustion- based power plants. The plants consume primarily electricity and fossil fuels (natural gas or fuel oil) for steam production. Their usage affects the edible oil production cost and impacts on climate change. The above facts force us to look for alternatives. By-product (husk) utilization can reduce exhaustible energy consu…
The Influence of Nanoparticle Shape on Protein Corona Formation
2020
Nanoparticles have become an important utility in many areas of medical treatment such as targeted drug and treatment delivery as well as imaging and diagnostics. These advances require a complete understanding of nanoparticles' fate once placed in the body. Upon exposure to blood, proteins adsorb onto the nanoparticles surface and form a protein corona, which determines the particles' biological fate. This study reports on the protein corona formation from blood serum and plasma on spherical and rod‐shaped nanoparticles. These two types of mesoporous silica nanoparticles have identical chemistry, porosity, surface potential, and size in the y ‐dimension, one being a sphere and the other a …
Particle radiation in microelectronics
2012
The unavoidable presence of particle radiation in space and on the ground combined with constantly evolving technology necessitates a deep understanding of the basic mechanisms underlying radiation effects in materials and electronic devices. This thesis provides an overview of the different radiation environments, with a review of the interaction mechanisms between energetic particles and matter. In this work a new semi-empirical model for estimating the electronic stopping force of solids for heavy ions is introduced. Radiation effects occurring in microelectronics due to particle radiation are also discussed with a brief introduction to radiation hardness assurance (RHA) testing of elect…
Soil carbon in Mediterranean ecosystems and related management problems
2011
Sterilization of three-dimensional tissue engineering scaffolds by supercritical carbon dioxide
2014
Medical devices, implants or patient-care equipment that will come into intimate contact with a patient must be effectively decontaminated to prevent infection or disease transmission. Non-sterile devices have significant ramifications for patient morbidity and mortality and two processes must be undertaken in order to make an item acceptable for use or implantation: cleaning and disinfection (or sterilization) [1]. Sterilization is the destruction of living organisms, and must be done without damaging the material surface and without compromising the bulk material strength or biocompatibility of implantable device. Common sterilization processes include steam autoclaving, gamma irradiation…