Protection of the high-voltage equipment with reduced insulation strength

Power transformer is the most expensive equipment on a substation. It is always necessary to get needed benefit with the lowest expenses. Producing of power transformers with reduced insulation strength is one of the possible ways to reduce expenses. Exploitation of such transformers was begun in the end of 70-th in the last century. Protection from overvoltages was done with valve-type magnetic combined surge arresters with increased blanking voltage during switching overvoltages. Nowadays there is the necessity of replacement of those devices. That’s why modernized nonlinear surge arrester was invented. This master’s thesis is focused on the use research of that modernized device in comparison with usual nonlinear surge arresters. The goal is to show the lightning overvoltages level using different types of nonlinear surge arresters and then calculations of the lightning protection reliability.

Use of thin films obtained by plasma polymerization for grain protection and germination enhancement

In this work, preliminary results of the use of hydrophobic thin films obtained by plasma deposition to protect grains and seeds are presented: grains coated by the films did not present biological degradation when stored in a saturated water vapor environment, but had their germination accelerated in the presence of water. A model that explains the difference of behavior of the films when exposed to water in vapor form or in liquid form, based on the formation of microchannels within the film that lead to water uptake in seeds, is presented. The model was successfully tested using quartz crystal measurements, which showed that the microchannels within the films can favor the adsorption and permeation of water when the films are immersed in water.

Jóvenes que estuvieron en el sistema de protección social a la infancia : reflexiones a partir de una investigación realizada en Girona, España = Young people who were in the child protection system : reflections from a study done in Girona, Spain

Research on residential care is still scarce despite its high implementation in Spain. This article presents the results of a research using qualitative methods. The study analyses the situation experienced by young people who lived in foster care in the province of Girona (1994-2002) based on their opinions and perceptions expressed in a semi-structured interview. The results, clustered into subcategories, show lack of knowledge about the reasons why they needed foster care, if it was better being there than staying with their parents, and the lack of support for transition to adulthood. The study shows implications for children and youth policies, professional practice and research

The Child Protection System from the Perspective of Young People: Messages from 3 Studies

This article reports findings and reflections based on the results of three different research projects conducted between 2008 and 2013 and focusing on the perspective of young care leavers in Spain. The overall aim was to examine these young people’s perceptions and evaluations of how they were treated while in the public care system, mainly residential care. Reviewing these qualitative studies, the most common and relevant issues highlighted by young people were related to the following themes: (a) entering care; (b) stability and emotional bonds in care; (c) education; (d) friends; (e) labelling, stigmatization, rights and opportunities; (f) autonomy and responsibility versus overprotection; (g) contact with parents, siblings and extended family; (h) maltreatment in care; and (i) leaving care. One of the main elements used in their assessments was comparison (i) between their previous situation within their birth family and the quality of care experienced in the residential home; and (ii) between what these young people commonly refer to as “normal children” and children in care. Recommendations deriving from their advice and opinions are also debated

UVA I-protection effectiveness of bioactive compound and organic UV filters: an in vitro assessment

This research work aimed at determining the UVA effectiveness (UVA I/UV ratio), by diffuse transmittance analysis, of sunscreens developed with a bioactive substance, the rutin, associating or not with organic UVB-UVA filters incorporated at a phosphate-base O/W emulsion. Sunscreens provided conflicting and unpredictable results concerning the anti-UVA protection, specially, at the UVA I region. Possible interactions among the organic UV filters and the polyphenolic bioactive substance may have accounted with improvement or reduction of UV protection by a complex and not yet elucidated mechanism, probably regarding wavelength delocalization to superior or inferior values, by resonant molecule stabilization or destabilization.

Nanostructured systems containing an essential oil: protection against volatilization

The goal of this study was to evaluate the feasibility of preparing nanocapsules and nanoemulsions using tea tree oil as oily phase aiming to protect its volatilization. The nanostructures presented nanometric mean size (160-220 nm) with a polydispersity index below 0.25 and negative zeta potential. The pH values were 6.43 ± 0.37 and 5.98 ± 0.00 for nanoemulsions and nanocapsules, respectively. The oil content after preparation was 96%. The inclusion of tea tree oil in nanocapsules showed higher protection against volatilization. The analysis of mean size and polydispersity index of formulations presented no significant alteration during the storage time.

Protection between strains of Passion fruit woodiness virus in sunnhemp

The main objective of the present study was to evaluate the effect of the sunhemp (Crotalaria juncea) host species on the protective ability of two mild strains of Passion fruit woodiness virus (PWV), named F-101 and F-144, which had failed to protect passion flowers (Passiflora edulis f. flavicarpa) in previous experiments. The nucleotide sequences of the capsid protein (CP) gene and the 3'-non-translated region (3'-NTR) of these mild strains and the severe strain of PWV-SP were compared to confirm their relationship. The results of two protective tests with sunhemp plants in the greenhouse and one test under field conditions showed that all plants infected with either mild strain were protected against infection and/or symptom expression of the severe strain of PWV-SP. Evaluation of the relative concentration of the mild strains in sun hemp leaves showed an apparent uniformity in virus distribution in the leaf tissues, different than that which was previously reported for these mild strains in passion flower leaves. These results agree with previous studies that showed the effect of the concentration of the protective strains and the host species in the protection process.

Frequency converter protection against supply network phenomena

This master’s thesis is focused on power supply network disturbances and their effects on the frequency converter – one of the components of modern process crane electrical system. The most critical disturbance types, their causes and the effect they bring to crane electrical system was determined in this work. Variety of protective devices used for mitigation of disturbances is investigated. Device protection solutions for the frequency converter used in crane applications are presented. Analyses of the power supply requirements for frequency converter and various components of crane electrical system were carried out and as a result the crane power supply requirements list that guarantees normal crane operation was built. This list is to be included in crane projects for troubleshooting purposes in order to determine potentially dangerous network.

Formal and informal mechanisms for knowledge protection and sharing

The most important knowledge in firms is mostly tacit and embedded in individuals within the organization. This background knowledge that firms possess is used for creation of new knowledge and innovations. As firms today greatly concentrate on their core competencies, they need external knowledge from various collaboration partners. Thus, collaborative relationship governance, as well as control (use of appropriability mechanisms) over background (the input from each firm in innovative activities) and foreground knowledge (the output of collaboration activities) is needed in order to successfully create and capture value from innovative activities without losing core knowledge and competitiveness. Even though research has concentrated on knowledge protection and knowledge sharing, studies that combine both of these views and examine the effects of sharing and protection on value creation and capture have been rather limited. Studies have mainly focused on the protection of the output of innovation while forgetting the protection of the input of innovation. On the other hand, as the research concentrating on the output of innovation tends to favor formal mechanisms, informal mechanisms have remained more unknown to researchers as well as managers. This research aims to combine the perspectives of knowledge sharing and knowledge protection and their relationship with value creation and value capture. The sharing and protection are viewed from two points of view: the use of appropriability mechanisms, as well as governance of the collaborative relationship. The study consists of two parts. The first part introduces the research topic and discusses the overall results. The second part comprises six complementary research publications. Both qualitative and quantitative research methods are used in the study. In terms of results, the findings enhance understanding of the combined use of formal and informal mechanisms for knowledge protection and sharing. Informal mechanisms appear to be emphasized in the protection of background knowledge, and thus are prerequisites for innovation, whereas formal mechanisms are relied on more for protecting the results of innovative activities. However, the simultaneous use of the formal and informal mechanisms that are relevant to the particular industry and innovation context is recommendedthroughout the collaborative innovation process. Further, the study adds to the current knowledge on HRM as an appropriability mechanism: on the firm level its uses include assessing and hedging against employee-related risks such as knowledge leaking and knowledge leaving. A further contribution is to the research on HRM protection and its interrelations with other appropriability mechanisms, its constituents, and its potential use in the area of knowledge protection.

Quantitative Sustainability Disclosure –An international comparison and its impact on investor valuation

This research focuses on the link between quantitative sustainability disclosure and information asymmetry. It builds upon previous research which links information asymmetry with voluntary disclosure. Stakeholders from the financial services sector claim that sustainability disclosure needs to be more numerical and comparable between companies. This research covers 111 firms from Denmark, Finland, the Netherlands and Sweden from non-service industries and studies how quantitative their sustainability disclosure is, and whether or not there is a negative relation with information asymmetry. The results support the hypotheses, where two out of three information asymmetry proxies have a significant negative relation with quantitative disclosure. Size is supported as a moderating factor. Quantitativity also proves to have a significant link with third party sustainability ratings. The direct link between quantitativity and cost of capital is not however supported.

Feasibility study of the available relay protection solutions for microgrids

Thesis talks about relay protection for microgrids. Microgrid operation sets more challenges than traditional utility grid protection because of lower fault current levels. Solutions for these challenges are discussed in this paper. Thesis also studies available relay protection solutions and figures out how they would fit for microgrid protection.

"Protection des animaux en Finlande"

14 x 23 cm

"Protection des animaux en Finlande"

14 x 22 cm