The role of smart sensor networks for voltage monitoring in smart grids

The large-scale deployment of the Smart Grid paradigm will support the evolution of conventional electrical power systems toward active, flexible and self-healing web energy networks composed of distributed and cooperative energy resources. In a Smart Grid platform, distributed voltage monitoring is one of the main issues to address. In this field, the application of traditional hierarchical monitoring paradigms has some disadvantages that could hinder their application in Smart Grids where the constant growth of grid complexity and the need for massive pervasion of Distribution Generation Systems (DGS) require more scalable, more flexible control and regulation paradigms. To try to overcome these challenges, this paper proposes the concept of a decentralized non-hierarchal voltage monitoring architecture based on intelligent and cooperative smart entities. These devices employ traditional sensors to acquire local bus variables and mutually coupled oscillators to assess the main variables describing the global grid state

Bokvalitet på norske asylmottak

-Er bokvaliteten på norske asylmottak god nok, hvordan påvirker den asylsøkernes livskvalitet, hvilke organisatoriske grep kan gi forbedring? Gjennom casestudier av utvalgte asylmottak, befaringer og bilder gir denne rapporten eksempler på sammenhenger mellom fysiske omgivelser, asylsøkeres livskvalitet og forholdet til lokalsamfunnet. Studien viser også hvordan bolig og omgivelser kan brukes aktivt til å styrke asylsøkerne for integrering eller retur, samt sikre verdighet og funksjonsevne

Air Flow Measurements during Medium-Voltage Load Current Interruptions

Air has been considered a good alternative to SF6 as arc quenching medium for load break switchgear at medium voltage ratings. In this work, the air flow characteristics and influence from the electric arc have been studied for typical currents and over-pressures. The cooling air velocity is typically in the range 150 - 200 m/s and thus well below supersonic speed. The arc and the surrounding hot air severely affect the air flow pattern by causing clogging in the contact and nozzle region

Nozzle Wear and Pressure Rise in Heating Volume of Self-blast Type Ultra-high Pressure Nitrogen Arc

This paper reports on experiments with ultra-high pressure nitrogen arcs in a self-blast type switch design. The effect of filling pressure on nozzle mass loss and pressure-rise in the heating volume were investigated. An arc current peak of 130 A at 190 Hz and a fixed inter-electrode gap of 50 mm were used throughout the experiment. The arc burns inside a polytetrafluoroethylene nozzle with a gas outflow vent in the middle. Nitrogen filling pressure of 1 bar, 20 bar, and 40 bar was tested, which also covers the supercritical region. Moreover, to study the effect of vent size on blow pressure near current zero, three different vent dimensions were investigated. By increasing the filling pressure, the energy deposited in the arc increases as a result of increased arcing voltage. It was observed that the pressure-rise in the heating volume is linked to the filling pressure, while the vent size plays a crucial role in the blow pressure near current zero. The nozzle mass loss per unit energy deposited in the arc is found to be independent of the filling pressure

Drivere og barrierer for bruk av servicescape i storytelling: eksempler fra reiselivsnæringen

Dybdebasert master, 120 studiepoeng. Spesialisering markedsføringledelseAbstract (engelsk sammendrag) There is a growing interest in creating positive experiences for consumers, especially in the tourism industry. Our context is farm tourism. One way to enhance the customer experience is by telling good stories (Mossberg, 2008). By linking the story to the servicescape, the stories will be even more effective at creating extraordinary experiences (Mossberg, 2008). Limited research has been conducted on the use of servicescape, and as far as we know, no study has yet investigated drivers and barriers to using servicescape in storytelling. However, these barriers and drivers might have an influence on the tourism provider’s use of the servicescape in storytelling. The research method chosen in this thesis was an explorative study with the use of in-depth interviews. Our interview guide was semi-structured. We found that there were several drivers and barrier to using the servicescape in storytelling. These were connected to authenticity, interest, knowledge, and resources. Authenticity was found to be important for the tourism provider, which is in line with research regarding this same topic from the perspective of tourists (Mossberg & Johansen, 2008). However, even though tourists demand only stories that can be perceived as authentic, it was not possible for the tourism provider to present stories connected to the servicescape that were not true. On the other hand, economy is a barrier for utilising and developing the servicescape, and will influence the way in which it can be used in storytelling. Furthermore, by using resources to develop the servicescape, economy will act as a driver for linking the latter to the stories. A link between the storytelling and the servicescape will influence the customer in a one-time purchase in a better way (Gilliam & Zablah, 2013). Furthermore, we found that knowledge is also a driver and a barrier for using the servicescape in storytelling. As a driver, knowledge about the history of the farm makes it easier for the tourism provider to make use of the servicescape. Lack of knowledge, on the other hand, will be a barrier to integrating the servicescape in storytelling. The tourism provider’s interest in the story is a driver for using the servicescape in storytelling. Knowledge and interest are important to tell a story in an effective way. The results of our research can help tourism providers to identify which of the drivers and barriers affect their use of the servicescape in storytelling. These providers can then seek to overcome the barriers and utilise the drivers, and in the end, tell better stories using the servicescape. Our study contributes new knowledge and a framework with findings about which drivers and barriers can influence the use of servicescape in storytelling. We suggest that our findings should be tested in future studies

Arc extinction with nitrogen at 1-40 bar in a puffer-like contact configuration

To develop cost-efficient subsea switchgear for large sea depths, the extinction of arcs under high filling pressures must be understood. In this work, arc-extinction experiments have been performed with a puffer-like contact configuration using nitrogen at different filling pressures as the current interruption medium. The main finding is that, for the given contact configuration, the currentinterruption capability was lower at 20 and 40 barabs than at 1 and 10 barabs. While higher pressures result in higher cooling flow rates and longer flow times given the same puffer volume, compression spring and nozzle geometry; it does not necessarily improve the arc-extinction capability. This is probably because higher filling pressures increase the arc voltage and total energy dissipated in the arcing zone. Because the filling pressure greatly influences the flow characteristics, the puffer design should be optimized for each pressure level

MAS and MANS Predicts repeated sprint ability in youth soccer players

International Journal of Exercise Science 16(6): 846-854, 2023. The study investigated the impact of maximal aerobic speed (MAS) and maximal anaerobic sprint (MANS) on repeated sprint ability (RSA) in soccer. Methods: 17 amateur-to semi-professional soccer players, age 19 (± 4) years, were tested for maximal oxygen consumption (VO2max), oxygen cost of running (Cr), RSA consisting of 15×20m sprint each divided by a 100 seconds dribble track, and 40-meter sprint performance. MAS was calculated as VO2max × Cr −1, and MANS was defined as the highest velocity in the 40-meter sprint. Results: There was a strong correlation between MAS and average 20-meter RSA velocity (r = 0.760; p \u3c 0.01), and between MAS and performance decrement (r = -0.648; p \u3c 0.01). The product of 0.5MAS + 0.5MANS exhibited the strongest correlation with RSA (r = 0.813; p \u3c 0.01). Conclusion: The combination of MAS and MANS strongly predicted RSA. High-intensity aerobic interval training (HIIT) and maximal strength training (MST) are recommended to improve MAS and MANS, and could thus lead to better RSA on the soccer field

Ageing of Technical Air and Technical Air with 7.5% C5-Fluoroketone by Free-Burning Arcs

This paper reports on the effect of ageing by free-burning arcs in 7.5% C5-fluoroketone (C5-FK) with 92.5% technical air in comparison to that in technical air (80% N2, 20% O2) at 1.3bar absolute pressure. The gases are aged by applying a series of arcs dissipating an accumulated energy of around 315kJ. It is found that the arc voltages in technical air and technical air with C5-FK are in the same range and do not vary significantly as a function of ageing or current amplitude (∼40-900 A). Contact erosion in both mediums is found to be similar if the discharge procedure is same. However, erosion increases significantly if ageing is performed in a short contact gap that needs more arcing operations to achieve similar level of arcing energy accumulation. Furthermore, gas decomposition by-products are analysed using gas chromatography coupled with mass-spectrometry