Search results for "STED"
showing 10 items of 2256 documents
Long-term ozone exposure of potato: Free radical content and leaf injury analysed by Q-band ESR spectroscopy and image analysis
2008
This paper presents Q-band electron spin resonance (ESR) studies on free radicals (FR) generated in potato leaves exposed to different O(3) levels in open-top chambers (OTC), together with a quantitative study of the relationship between FR signal intensity and area of potato leaf damage. The advantages of Q-band when compared to X-band ESR spectroscopy are analysed, the main advantage being an absence of overlapping between Mn(II) and FR signals, allowing a quantitative study of FR signal intensity. This study also reports on a graphical method developed to quantitatively measure the damaged area on leaves caused by ozone exposure. Results indicate a direct relationship between FR signal i…
Trusted dynamic storage for dunbar-based P2P online social networks
2014
Online Social Networks (OSNs) are becoming more and more popular in today's Internet. Distributed Online Social Networks (DOSNs), are OSNs which do not exploit a central server for storing users' data and enable users to have more control on their profile content, ensuring a higher level of privacy. The main challenge of DOSNs comes from guaranteeing availability of the data when the data owner is offline. In this paper we propose a new P2P dynamic approach to the problem of data persistence in DOSNs. By following Dunbar's approach, our system stores the data of a user only on a restricted number of friends which have regular contacts with him/her. Users in this set are chosen by considerin…
Design of experiment approach for the optimization of polybrominated diphenyl ethers determination in fine airborne particulate matter by microwave-a…
2015
Abstract A sensitive and selective procedure for the determination of 12 polybrominated diphenyl ethers (BDE-28, BDE-49, BDE-47, BDE-66, BDE-100, BDE-119, BDE-99, BDE-155, BDE-154, BDE-153, BDE-139 and BDE-183) in airbone particulate matter (PM2.5) at trace level has been developed. The proposed method includes extraction PM2.5-bound PBDEs by microwave-assisted extraction (MAE) followed by gel permeation chromatography (GPC) clean-up and determination by GC-MS/MS using a programmed temperature vaporizer (PTV) in large volume injection (LVI) mode to introduce the sample to the chromatographic system. A design of experiment (DoE) approach was used for the optimization of large volume injectio…
Drivers affecting the adoption and effectiveness of social media investments: The Italian wine industry case
2019
Purpose The purpose of this paper is twofold: first, to identify distinct organisational models in a sample of firms operating in the wine industry; and second, to identify the main internal resources that characterise those firms most motivated towards the adoption of social media (SM) tools and those that perceive SM investment as more effective. Design/methodology/approach The empirical investigation was carried out by administering an online questionnaire to a sample of 82 Sicilian wineries. The principal component analysis was used to identify latent factors that drive managers to invest in SM technologies and to measure the impact perceived by managers. Subsequently, a cluster analys…
Influence of Geographical Location of Spirulina (Arthrospira platensis) on the Recovery of Bioactive Compounds Assisted by Pulsed Electric Fields
2022
Spirulina (Arthrospira platensis) has been consumed by humans since ancient times. It is rich in high added-value compounds such as chlorophylls, carotenoids and polyphenols. Pulsed electric fields (PEF) is an innovative non-thermal technique that improves the extraction of bioactive compounds from diverse sources. PEF pre-treatment (3 kV/cm, 100 kJ/kg) combined with supplementary extraction with binary solvents at different times was evaluated to obtain the optimal conditions for extraction. In addition, the results obtained were compared with conventional treatment (without PEF pre-treatment and constant shaking) and different strains of Spirulina from diverse geographical locations. The …
A visual framework to create photorealistic retinal vessels for diagnosis purposes
2020
The methods developed in recent years for synthesising an ocular fundus can be been divided into two main categories. The first category of methods involves the development of an anatomical model of the eye, where artificial images are generated using appropriate parameters for modelling the vascular networks and fundus. The second type of method has been made possible by the development of deep learning techniques and improvements in the performance of hardware (especially graphics cards equipped with a large number of cores). The methodology proposed here to produce high-resolution synthetic fundus images is intended to be an alternative to the increasingly widespread use of generative ad…
Determination of 40 currently used pesticides in airborne particulate matter (PM 10) by microwave-assisted extraction and gas chromatography coupled …
2011
A confirmatory and sensitive procedure has been developed for the determination of 40 currently used pesticides (Cups) in airborne particulate matter (PM 10) at trace level. The proposed method includes extraction of PM 10-bound pesticides by microwave-assisted extraction (MAE) followed by a gel permeation chromatography (GPC) clean-up and determination by GC-MS/MS. The injection mode and the main parameters in MS/MS were optimized. The matrix effect was also evaluated. Recoveries ranged from 70 to 120% except for pyrimethanil and pirimicarb. The limit of quantification (LOQ) ranged from 1.32 to 39.47 pg m(-3), when air volumes of 760 m(3) were collected. The method was applied to 38 sample…
Nikotīnamīda un dikarbonskābju kokristālu tvaikķīmiskas veidošanās izpēte
2016
Nikotīnamīda un dikarbonskābju kokristālu tvaikķīmiskas veidošanās izpēte. Ķeķe A., darba vadītāja vadošā pētniece Dr. chem. Orola L. Bakalaura darbs, 41 lappuses, 27 attēli, 1 tabula, 40 literatūras avoti. Latviešu valodā. Darbā veikta nikotīnamīda kokristālu tvaikķīmiska iegūšana ar dažādām dikarbonskābēm (malonskābi, dzintarskābi, glutārskābi, adipīnskābi, pimelīnskābi, suberīnskābi, azelaīnskābi, sebacīnskābi). Iegūtie kokristāli analizēti, izmantojot pulvera rentgendifraktometrijas metode. Kokristālu pārvēršanās pakāpes noteikšanai izmantoja tādas kvantatīvās analīzes metodes kā pilna profila analīzi un Ritvelda metodi.
Cost Effective Treatments to Replace Galvanic Processes
2009
Some of the most severe problems in the replacement of galvanic treatment with PVD coatings reside, first of all, in the higher costs of vacuum processes and in the difficulty to coat many 3D small samples. This work describes the results obtained by using energetic deposition vacuum processes, of the family of Ion Plating Plasma Assisted (IPPA), using both thermal and sputtering sources, able to reduce dramatically the duration of deposition process and to eliminate the substrate heating and their pre-cleaning. Regarding the small 3D samples, an innovative structure, named "Ionic Rotarybarrel" is presented. The realised treatments are in the fields of decorative, protective and tribologica…
Derecho de los hijos nacidos por reproducción asistida a conocer la identidad de sus padres biológicos: Breves reflexiones y propuestas
2018
The present communication intends to analyze and reflect on the existing problem and the conflict of rights produced regarding the need of information of a son to know the identity of his biological parents, possible discrimination by birth. Comparative law. Analysis of the right to personal and family privacy, and right to Identity. Consideration of public information as an essential element of the practice of techniques