Search results for "chemistry [Carbon]"
showing 10 items of 2259 documents
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…
Oppiennätyksistä opetussuunnitelman perusteisiin : lukion kemian kansallisen opetussuunnitelman kehittyminen Suomessa vuosina 1918-2016
2017
Kemiasta tuli itsenäinen oppiaine vuonna 1918. Lukion lukusuunnitelmaan kemia tuli vasta vuodesta 1941. Aina 1980-luvun puoleen väliin saakka opetussuunnitelmat olivat valtakunnanhallinnon antamia. Vuodesta 1985 lähtien Koulu- ja Opetushallitus ovat antaneet valtakunnalliset perusteet koulutuksen järjestäjien laatimien ja vahvistamien opetussuunnitelmien pohjaksi. Tutkimuksen päätavoitteena on kuvata lukion kemian kansallisen opetussuunnitelman kehittymistä Suomen itsenäisyyden alusta tähän päivään saakka. Tutkimuksen teoriaosassa käsitellään eri maissa tapahtunutta kemian opetuksen ja opetussuunnitelman kehittymistä varsin perusteellisesti 1800-luvulta nykypäivään. Siinä tarkastellaan eri …
A novel intrinsically disordered outer membrane lipoprotein ofAggregatibacter actinomycetemcomitansbinds various cytokines and plays a role in biofil…
2017
Intrinsically disordered proteins (IDPs) do not have a well-defined and stable 3-dimensional fold. Some IDPs can function as either transient or permanent binders of other proteins and may interact with an array of ligands by adopting different conformations. A novel outer membrane lipoprotein, bacterial interleukin receptor I (BilRI) of the opportunistic oral pathogen Aggregatibacter actinomycetemcomitans binds a key gatekeeper proinflammatory cytokine interleukin (IL)-1b. Because the amino acid sequence of the novel lipoprotein resembles that of fibrinogen binder A of Haemophilus ducreyi, BilRI could have the potential to bind other proteins, such as host matrix proteins. However, from th…
Natural Halogen Emissions to the Atmosphere: Sources, Flux, and Environmental Impact
2022
Understanding the atmospheric geochemical cycle of both natural and anthropogenic halogens is important because of the detrimental effect halogens have on the environment, notably on tropospheric and stratospheric ozone. Oceans are the primary natural source for atmospheric Cl, F, Br, and I, but anthropogenic emissions are still important, especially for Cl. While emissions of human-made halocarbons (e.g., chlorofluorocarbons or CFCs) are expected to continue to decrease allowing progressive stratospheric ozone recovery, volcanic activity (e.g., clusters of mid-scale explosive eruptions or large-scale explosive eruptions) might disturb this recovery over the next decades. This review provid…
Feedback and Communication in Active Hydrogel Spheres with pH Fronts: Facile Approaches to Grow Soft Hydrogel Structures
2021
Abstract Compartmentalized reaction networks regulating signal processing, communication and pattern formation are central to living systems. Towards achieving life‐like materials, we compartmentalized urea‐urease and more complex urea‐urease/ester‐esterase pH‐feedback reaction networks into hydrogel spheres and investigate how fuel‐driven pH fronts can be sent out from these spheres and regulated by internal reaction networks. Membrane characteristics are installed by covering urease spheres with responsive hydrogel shells. We then encapsulate the two networks (urea‐urease and ester‐esterase) separately into different hydrogel spheres to devise communication, pattern formation and attracti…
A revision of the structure and stratigraphy of pre-Green Tuff ignimbrites at Pantelleria (Strait of Sicily)
2013
International audience; At Pantelleria, peralkaline silicic magmas were erupted across a range of eruptive typologies and magnitudes: pyroclastic flows, Plinian to strombolian pumice fallout and lava flows. In this paper we focus on the intermediate cycle of eruptive activity which is bracketed by ignimbrite units slightly older than the two caldera collapses which marked the volcanological activity of the island. This age interval (180-85 ka) was punctuated by six ignimbrite-forming eruptions (silicic and variably peralkaline) for a cumulative erupted magma volume of approximately 6 km3 dense rock equivalent. Based on new 40Ar/39Ar (Na,K)-feldspar ages and petrographic data, we propose an …
Computational Fluid Dynamics (CFD) and Finite Element Analysis (FEM) of a Customized Stent-Graft for Endovascular (EVAR) Treatment of Abdominal Aorti…
2023
Background: The treatment of abdominal aortic aneurysm (AAA) is today commonly treated by inserting a stent-graft by the endovascular route, without resorting to open surgery. However, some clinical cases do not allow this less invasive approach, meaning that the stent-graft cannot be inserted and open surgery is used. Methods: In the study, we propose a fluid–structure interaction (FSI) analysis of an aneurysmatic aorta that could not be treated with Endovascular Aneurysm Repair (EVAR). The vessel is reconstructed through segmentation from CT scans and subsequently modeled on CAD software to create the surface and thickness of the vessel itself. Subsequently, we proceeded to carry out Comp…
Buccal Thin Films as Potent Permeation Enhancers for Cytisine Transbuccal Delivery
2022
Cytisine (CYT) is a powerful anti-smoking compound which could greatly benefit from transbuccal delivery because of both its unfavorable pharmacokinetics after oral administration and its intrinsic ability to permeate the buccal mucosa. This work aims to design CYT-loaded buccal thin films suitable for transbuccal drug delivery due to its capability of promoting the interaction between CYT and the buccal membrane. The solvent casting method was employed to prepare several thin films combining various excipients such as matrixing polymers, mucoadhesion agents, plasticizers and other compounds as humectants and sweeteners, component ratios and solvents. A total of 36 compositions was prepared…
Applications of Quantum Chemistry in Spectroscopy: Molecules, Complexes of Van der Waals, trapped Molecules
2009
I described in this memory my activities as a researcher at Tomsk well before 2003, in succession to the State University of Tomsk in the Faculty of Physics, Institute of Physics of Siberia, and the Institute of 'Atmospheric Optics, in France since then, mostly at the University of Bourgogne (ICB), but also at the University of Lille I (PhLAM) and the University of Marne-la-Vallée (LCT). Part of my work has been dedicated to the evaluation by calculating ab initio of rovibrational constants for quasi-spherical molecules. The centrifugal distortion constants and the dipole moment of the molecule SO2F2 were calculated to validate the tensor theory and interpreter the spectrum. I twas shown th…
Assessment of Physical and Chemical Stability of Different Magnesium Compounds in Tablets
2020
Modern lifestyle, excessive chemicalization of agricultural products, excessive processing and refining of food, cause a decrease in daily intake of magnesium, cation with an extremely important role in prevention and treatment of many diseases. As a result, there arises the need for extra magnesium intake in the form of dietary supplements. In this study were evaluated the physical and chemical stability of magnesium-containing tablets, depending on the active compound and the excipients used. Magnesium tablets in the form of orotate, lactate, citrate, oxide and hydroxide were taken into study and physical and chemical stability were observed over the validity period, at 6 and at 12 month…