Search results for "Carbon dioxide"
showing 10 items of 564 documents
Carbon Dioxide Activation and Reaction Induced by Electron Transfer at an Oxide-Metal Interface
2015
A model system has been created to shuttle electrons through a metal-insulator-metal (MIM) structure to induce the formation of a CO2 anion radical from adsorbed gas-phase carbon dioxide that subsequently reacts to form an oxalate species. The process is completely reversible, and thus allows the elementary steps involved to be studied at the atomic level. The oxalate species at the MIM interface have been identified locally by scanning tunneling microscopy, chemically by IR spectroscopy, and their formation verified by density functional calculations.
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…
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…
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…
A one-pot method to enhance dissolution rate of low solubility drug molecules using dispersion polymerization in supercritical carbon dioxide
2009
Preparation of pH sensitive poly(vinilydenefluoride) porous membranes by grafting of acrylic acid assisted by supercritical carbon dioxide
2010
Aim of this work is to study the preparation of pH sensitive membranes for biomedical applications via thermal induced graft polymerization of acrylic acid (AA) on poly(vinilydenefluoride) (PVDF) assisted by supercritical carbon dioxide (scCO2). Using scCO2 as a solvent and swelling agent, the monomer and initiator (benzoyl peroxide) could diffuse faster and distribute more uniformly into the polymer matrix. A better control of the final molecular architecture should be achieved because bimolecular grafting reactions are accelerated with respect to chain degradation processes. Commercial hydrophobic PVDF porous matrixes were selected as model membranes. Grafted polymers were characterized b…