Search results for " isola"

Structure and Matrix Isolation Infrared Spectrum of Formyl Fluoride Dimer:  Blue-Shift of the C−H Stretching Frequency

2006

Infrared spectroscopy (IR) of formyl fluoride (HCOF) dimer is studied in low-temperature argon and krypton matrixes. New IR absorptions, ca. 17 cm(-1) blue shifted from the monomer C-H stretching fundamental, are assigned to the HCOF dimer. The MP2/6-311++G calculations were utilized to define structures and harmonic frequencies of various HCOF dimers. Among the four optimized structures, the dimer having two C-H...O hydrogen bonds possesses strongest intermolecular bonding. The calculated harmonic frequencies of this dimer structure are shifted from the monomer similarly as observed in the experiment. Thus, we suggest that the experimentally observed blue shifted C-H bands belong to the di…

How COVID-19 kick-started online learning in medical education-The DigiMed study.

2021

Background The coronavirus disease 2019 (COVID-19) pandemic led to far-reaching restrictions of social and professional life, affecting societies all over the world. To contain the virus, medical schools had to restructure their curriculum by switching to online learning. However, only few medical schools had implemented such novel learning concepts. We aimed to evaluate students’ attitudes to online learning to provide a broad scientific basis to guide future development of medical education. Methods Overall, 3286 medical students from 12 different countries participated in this cross-sectional, web-based study investigating various aspects of online learning in medical education. On a 7-…

EPR Studies of Atomic Impurities in Rare Gas Matrices

2003

In this article we give an overview of the matrix isolation technique combined with electron paramagnetic resonance (EPR) detection for embedded atomic impurities in solid rare gases. A special emphasis is put on impurity – matrix coupling effects combining both experimental and theoretical approaches.

Exact Response Time Analysis of Hierarchical Fixed-Priority Scheduling

2009

Hierarchical scheduling has recently been used to provide temporal isolation to embedded virtualised systems. Response time analysis is a common way to derive a schedulability test for these systems. This paper points out that response time analysis for hierarchical fixed-priority scheduling found in the literature is only exact for tasks of the highest priority domain. For the rest of the tasks is an upper bound. In our work, we provide the exact analysis and we compare it with previously published works.

Prognostic indicators in pediatric clinically isolated syndrome

2017

To assess prognostic factors for a second clinical attack and a first disability worsening event in pediatric clinically isolated syndrome (pCIS) suggestive of Multiple Sclerosis (MS) patients. Objective: To assess prognostic factors for a second clinical attack and a first disability-worsening event in pediatric clinically isolated syndrome (pCIS) suggestive of multiple sclerosis (MS) patients. Methods: A cohort of 770 pCIS patients was followed up for at least 10 years. Cox proportional hazard models and Recursive Partitioning and Amalgamation (RECPAM) tree-regression were used to analyze data. Results: In pCIS, female sex and a multifocal onset were risk factors for a second clinical att…

Alternative reproductive tactics and the propensity of hybridization

2009

One explanation for hybridization between species is the fitness benefits it occasionally confers to the hybridizing individuals. This explanation is possible in species that have evolved alternative male reproductive tactics: individuals with inferior tactics might be more prone to hybridization provided it increases their reproductive success and fitness. Here we experimentally tested whether the propensity of hybridization in the wild depends on male reproductive tactic in Calopteryx splendens damselflies. Counter to our expectation, it was males adopting the superior reproductive tactic (territoriality) that had greatest propensity to hybridize than males adopting the inferior tactics (…

Impact of physical activity on response to stress in people aged 65 and over during COVID-19 pandemic lockdown.

2021

Background: The outbreak of the COVID-19 pandemic has negatively affected the lives of many people. In particular, restrictions of physical activity (PA) due to pandemic-related lockdown have impacted their psychological status. The aim of this work was to investigate the relationship between PA habits, before the pandemic and during the lockdown, and responses to stress due to home isolation during the lockdown, in older people. Methods: To this aim, an online survey addressed to people aged 65 years and over was conducted during the first pandemic wave in Italy (Study 1). To explore the effect of PA restrictions on responses to stress over time, the survey was replicated during the second…

AN UNUSUAL CASE OF COMMINGLED HUMAN REMAINS FROM ISOLA DELLE FEMMINE (PALERMO, ITALY)

2009

Saules aktīvo apgabalu īpatnību pētījumi, izmantojot novērojumus mikroviļņu diapazonā

2013

Elektroniskā versija nesatur pielikumus

Extension and Tuning of Virtual Synchronous Machine to Avoid Oscillatory Instability in Isolated Power Networks

2020

The risk of oscillatory instability introduced by virtual synchronous machines (VSM) control in isolated power networks is investigated. The considered control is a common scheme widely studied in literature, in several configurations and for different case studies. The impact of the VSM control on the system stability is examined for the existing power network of a Mediterranean island. The VSM control is implemented within the power converters interfacing the energy storage systems (ESS) installed in the network. Simulations and analysis show the occurrence of oscillatory instability in the system, with the ESS-VSM and the synchronous machines of the network progressively swinging against…