Search results for "O2"
showing 10 items of 1115 documents
Chemical, Antioxidant and Biological Studies of Brassica incana subsp. raimondoi (Brassicaceae) Leaf Extract
2023
Brassica incana subsp. raimondoi is an endemic taxon present in a restricted area located on steep limestone cliffs at an altitude of about 500 m a.s.l. in eastern Sicily. In this research, for the first time, studies on the phytochemical profile, the antioxidant properties in cell-free and cell-based systems, the cytotoxicity on normal and cancer cells by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) assay, and on Artemia salina Leach, were performed. The total phenolic, flavonoid, and condensed tannin contents of the leaf hydroalcoholic extract were spectrophotometrically determined. Ultra-performance liquid chromatography—tandem mass spectrometer (UPLC-MS/MS) analysi…
Implementation of the eHealth Project in Latvia: Project audit perspective
2016
In order to improve effectiveness of provision of healthcare service, the project implemented by the Ministry of Health- ”E-health in Latvia” is a step towards the right direction. It will provide the possibility for patients to ensure a greater control over their health issues, by maintaining healthy habits, lifestyle, increase substantiation of adoption of decisions and speed of service in the healthcare industry, ensuring quality and accessible information; patients will receive more quality services and in a shorter period of time for issuance of prescription drugs. Nevertheless, the policy prepared by the Ministry of Health in the area of e-Health will not be implemented in the planned…
Micro-Economical Aspects of Public Projects: Impact Factors for Project Efficiency and Sustainability
2015
Project management approach in the public administration becoming gradually applied tool for implementation of different public programs and activities. Latvia has several methodological documentations to evaluate the possible benefits from infrastructure but still there is need for improvements as the only clear defined methodology is for transport sectors and those which have been provided by the European commission, but not always have been practically used in local municipalities’ project evaluations. Public projects, and planning for such projects, generally have the following characteristics: • Such projects are inherently risky due to long planning horizons and complex interfaces. • …
Project Management in the Port Development Project in Latvia
2016
Paper analyse case study of performance and compliance audit in the port development project in Latvia. Author has participated in the audit process evaluating project management application practical approach in the project implemented by the Riga Freeport Authority and co-funded by the Cohesion Fund “Development of Infrastructure on Krievu Island for the Transfer of Port Activities from the City Centre”. Despite the mass media reports that the Riga Freeport Authority has successfully completed the project, only the construction phase of the project has been completed. During the following two years the stevedore activity must be transferred to the newly built port infrastructure on Krievu…
Properties of HO2• radicals induced by γ-ray irradiation in silica nanoparticles
2014
Abstract We report an experimental investigation on the effects of γ -ray irradiation in several types of silica nanoparticles previously loaded with O 2 molecules. They differ in specific surface and average diameter. By electron paramagnetic resonance (EPR) measurements we observe the generation of about 10 18 HO 2 • /cm 3 interstitial radicals. These radicals are induced by reaction of interstitial O 2 molecules with radiolytic H atoms, as previously suggested for O 2 -loaded bulk a-SiO 2 samples. However, at variance with respect to bulk materials, our experimental evidences suggest a different generation process of HO 2 • radical. In fact, by a detailed study of samples exposed to D 2 …
Alignement moléculaire : caractérisation et application à la mesure de thermalisation ultra-rapide et au contrôle de génération d'harmoniques
2013
The thematic of this thesis is molecular alignment. The latter is a very important topic that opens the way toward a much more thin control of many phenomenons. So, we have developed a new measurement technique of the molecular alignment along one axis that permits to preserve the sign of alignment. This one is, like other measurement techniques developed by the team,based on the measurement of the refractive index variation induced by the molecular alignment.The technique developed then also permits the molecular alignment measurement, being also an application of it because it allows the third harmonic generation. In the last study, molecular alignment is implemented to show that it bring…
Sostenibilidad empresarial y estrategias de divulgación de huella de carbono
2021
El cambio climático es uno de los mayores desafíos medioambientales en los actuales momentos, su creciente aceptación como una de las cuestiones más urgentes en el mundo, a nivel social, político y empresarial ha llevado a las organizaciones a introducir mecanismos de control y mitigación ambiental como parte de sus compromisos adquiridos, siendo uno de ellos la divulgación sobre emisiones de carbono. En este sentido, el sector empresarial, como ente dinamizador de las economías de todo el mundo, es uno de los principales agentes en la lucha contra el cambio climático; por otro lado, a pesar del aumento de la divulgación de GEI, hay aún evidencias relativamente escasas en la literatura de l…
Dried-Fruit Storage: An Analysis of Package Headspace Atmosphere Changes
2019
The quality of packaged dried foods depends on storage conditions and is determined largely by the initial gas composition inside and the transference through the container. The aim of this work was to analyze the O2 and CO2 concentrations within the internal atmosphere of the packaging. In this study, dried apricots and raisins were packaged in glass jars and polypropylene trays thermosealed with different polymers, and stored at 5, 15, 25, and 35 °
Iron Porphyrins as Models of Cytochromec Oxidase
2001
A series of iron porphyrins has been synthesized as models of cytochrome c oxidase; their activity as 4 e− catalysts in the reduction of dioxygen has been studied at pH 7. These compounds have been obtained by grafting very different residues onto the same iron complex, namely tripodal tetraamines, pickets, and straps, in order to change the environment of the metal center. In the case of porphyrins bearing a tripodal cap, the secondary amines have been alkylated with different substituents so as to modify the electronic environment of the distal pocket. Surprisingly, when the iron porphyrin is functionalized with four identical acrylamido pickets, the resulting complex exhibits biomimetic …
Reconsidering TOF calculation in the transformation of epoxides and CO2 into cyclic carbonates
2020
Abstract The combination of Lewis acids and Lewis bases, currently defined as catalysts and co-catalysts (or promoter) respectively, in the reaction between epoxides and CO2 to give cyclic carbonates, is discussed, starting from examples in which the Lewis base was used in larger amount with respect to the Lewis acid. In these cases, turnover frequency (TOF) values have been usually calculated taking into account solely the amount of the Lewis acid employed. The occurrence of two distinct reaction pathways, one catalysed by the sole Lewis base and the other one catalysed by the Lewis acid/Lewis base couple, in which the Lewis acid alone does not play a catalytic role, should bring researche…