Search results for "Critical"
showing 10 items of 3024 documents
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…
Collaborative professional practice for strengthening teacher educator identities in Eritrea
2021
Strengthening the identities of teacher educators is critical to quality teacher education and implementing change in the education sector. This study examines the professional identities of Eritrean teacher educators and how these identities can be strengthened through collaborative professional practice in a challenging context currently under reform. The focus is on the professional capacity building activities at the College of Education in Eritrea, which were implemented in collaboration with Finnish education partners. The paper reports on findings from an action-research informed study of a semester-long series of professional development seminars and an interview study with individu…
Insecure Firmware and Wireless Technologies as “Achilles’ Heel” in Cybersecurity of Cyber-Physical Systems
2022
In this chapter, we analyze cybersecurity weaknesses in three use-cases of real-world cyber-physical systems: transportation (aviation), remote explosives and robotic weapons (fireworks pyrotechnics), and physical security (CCTV). The digitalization, interconnection, and IoT-nature of cyber-physical systems make them attractive targets. It is crucial to ensure that such systems are protected from cyber attacks, and therefore it is equally important to study and understand their major weaknesses. peerReviewed
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…
Melt phase ring opening polymrization of lactide and glycolide assisted by supercritical carbon dioxide
2010
Supercritical carbon dioxide induces sterilization of PLLA scaffolds contaminated by E. coli.
2014
The common sterilization techniques are based on physical processes that involve, for example, the use of autoclaves or systems to radiation such as γ-rays that can cause a structural change of the polymer treated. Therefore, the use of supercritical carbon dioxide (scCO2) is an excellent alternative, as it does not induce any variation of biomaterials treated (Perrut M., 2012). It's a good candidate because is readily available at low cost, non-toxic and non-flammable, it has an easily accessible critical point (7.38 MPa and 304.2 K) and excellent transport properties and wettability (White A. et al., 2005). We report the development of a supercritical CO2 based process capable of steriliz…
Modeling Heterogeneous copolymerization in scCO2
2008
CO(2)-water supercritical mixtures: Test of a potential model against neutron diffraction data
2007
Abstract A neutron diffraction experiment on supercritical mixtures of water and CO 2 at two concentrations is presented. Data are analyzed within the EPSR framework and the water–water and water–CO 2 radial distribution functions are compared with those calculated by a Molecular Dynamics simulation performed by using the TIPS2 and EPM-M potential models for water and CO 2 respectively. It is found that the Molecular Dynamics simulation reproduces the overall shape of the site–site radial distribution functions, although missing a few subtle changes brought along when the CO 2 concentration is increased.