Optimizing Small-Scale Pumped Hydro Storage: A Case Study in Design and Operation

As many Norwegian hydropower plants approach the end of their operational lifetime and the demand for energy storage increases, redeveloping these plants into pumped storage should be considered. This thesis evaluates the feasibility of converting a small-scale hydropower plant in Bygland, Norway, into a pumped hydroelectric energy storage system compared to a conventional hydropower plant. To assess their advantages and limitations, this study evaluates the integration of various technologies, including pump-as-turbine, reversible pump-turbine, and conventional turbines. The penstock path and grid connection must be projected while the component dimensioning is optimized. To solve this, a linear programming model is developed using ten years of inflow data derived from an HBV model, along with historical outflow, spot price data, and component costs. The model calculates the net present value for a mean year representing a 50-year period, with different combinations of maximum flow rate and penstock diameters to conclude with the optimal configuration for each technology. The results indicate that the optimal configuration for each evaluated technology is profitable, although there are substantial differences in profitability between them. The most profitable configuration is the reversible pump-turbine, followed by the conventional configuration. Although the pump-as-turbine configuration was also profitable, it is considered unfeasible compared to the other alternatives. Pumped storage is particularly profitable during periods with high spot price volatility, where arbitrage is feasible. Comparing a fixed operational schedule to an optimized schedule demonstrates the significance of spot price and inflow prediction, as well as the importance of optimized operation. The findings in this project conclude that rehabilitating the existing hydropower plant to a pumped hydro storage system is profitable

A Practical Iron-Based Newman-Kwart Rearrangement Under Oxidative Conditions

Herein, we report that iron(II)/ammonium persulfate in aqueous acetonitrile mediates the Newman- Kwart rearrangement of O-aryl carbamothioates. Electron-rich substrates react rapidly under moderate heating to afford the rearranged products in excellent yields. The mild conditions, rapid reaction rates, and suitability for scale up offers immediate practical benefits to access functionalised thiophenols

Digital Twin - Transient Flow Conditions

En digital tvilling er et relativt nytt konsept. Det er noe som krever mye innsats, men med løfter om store belønninger både med tanke på bærekraft og fortjeneste. NTNUs forskningsavdeling for turbomaskineri bygger sakte opp sin egen digitale tvilling for sin fullskala ett-trinns sentrifugalkompressor. Arbeidet mot denne ambisjonen har pågått i årevis, og denne oppgaven er en del av det arbeidet. Med fokus på å dokumentere eksperimentelle data, som er avgjørende for videre utvikling av dagens digitale modell, har hovedmålet med denne oppgaven vært å utvikle en kompressorkurve som dekker et bredt spekter. Noe den digitale modellen kan modelleres etter. For å sikre gyldigheten av en slik kurve ble det også utviklet sekundære mål hvis formål var å sikre resultatenes legitimitet. Gjennom en rekke statiske og dynamiske eksperimenter har hovedmålet og begge sekundære mål blitt oppfylt. I tillegg har flere andre konklusjoner som er viktige for videre utvikling og eksperimentering blitt trukket. Kort oppsummert: trykktanken nedstrøms kompressoren er en viktig del av systemet når man eksperimenterer med strømninger lavere enn Q < 0.5 m3/s; de to “orifice”-platene installert på laboratoriet samsvarer stort sett med hverandre godt, men ikke nær nullstrøm; usikkerheter gjør at målinger tatt innenfor Q ∈ (−0.2, 0.2) m3/s bare kan betraktes som pekepinner, og ikke “sikre sannheter”; med det nåværende oppsettet er det ikke mulig å bruke differensialtrykket over kompressorens “bull-nose” for å måle noe meningsfullt; loggingsfrekvensen bør være minst 10 Hz for eksperimenter der Q < 0.5 m3/s; visse områder med lav respons har liten eller ingen innvirkning på kompressorkartkurvene; og til slutt, det kan være fordelaktig å redusere lengden på rørene til differensialtrykkmålerne. Eksperimentene som presenteres i denne oppgaven ble kun utført ved bruk av “kompressor-testriggen” ved turbomaskin-laboratoriet ved NTNU. Matlab ble brukt til å tolke resultatene fra disse eksperimentene, og mye arbeid er lagt i å lage kodene nesten helt automatiske. En kort usikkerhetsanalyse av “Type B” ble også gjennomført for å hjelpe med legitimiteten til resultatene.A Digital Twin is a relatively new concept, requiring a lot of effort, but with promises of great rewards in terms of sustainability and profits. NTNU’s turbomachinery research department is slowly building up their own digital twin for their full-scale single-stage centrifugal compressor. Work towards this ambition has been ongoing for years, and this thesis is part of that work. Focusing on providing experimental data, essential for further development on the current digital model, the primary objective of this thesis has been to develop a compressor curve covering a wide range, which the digital model can be modeled after. To ensure the validity of such a curve, secondary objectives with focus on ensuring the legitimacy of the results were also developed. Through a series of static and dynamic experiments, the primary objective, and all secondary objectives have been met. In addition, multiple other conclusions important for further development and experimentation have been drawn. Briefly summarised: the downstream pressure tank is an essential part of the compressor system, when experimenting with flows lower than Q < 0.5 m3/s; the two orifices installed at the laboratory mostly match each other well, but not near zero flow; uncertainties make it so that measurements taken within Q ∈ (−0.2, 0.2) m3/s can only be considered suggestive; with the current setup, it is not possible to use the differential pressure over the compressor bull-nose to measure anything meaningful; logging frequency should be at least 10 Hz for experiments where Q < 0.5 m3/s; certain areas with low response have little to no impact on the compressor map-curves; and finally, it could be beneficial to reduce the length of the differential pressure tubes. The experiments presented in this thesis were explicitly conducted using the “compressor test-rig” at the turbomachinery laboratory at NTNU. Matlab was used to interpret the results from those experiments, and extensive effort has gone into creating near-automatic scripts. A short uncertainty analysis of Type B was also orchestrated, to help with the legitimacy of the results

Causes and Consequences of Breeding Synchrony in the Snow Bunting (Plectrophenax nivalis )

Climate warming is happening rapidly in the Arctic and migratory birds are among the species expected to be affected by the predicted shifts in spring phenology. Using time-series data (1998 - 2014) from a population of snow bunting (Plectrophenax nivalis) nesting in High Arctic Svalbard, I investigated climatic effects on interannual variation in breeding synchrony and its fitness consequences. Breeding synchrony was here defined as the temporal synchrony in egg-laying on the population-level, which was estimated using a Synchrony Index (SI). Multi-model comparisons of linear regression models were used in three sections of analyses; i) onset of breeding in relation to climate, ii) breeding synchrony in relation to onset of breeding and climate, and iii) reproductive success in relation to breeding synchrony and climate. Timing of onset of breeding was negatively related to spring temperature. Furthermore, SI was positively related to spring precipitation and onset of breeding. Reproductive success, measured as mean number of fledglings, was positively related to breeding synchrony and mean summer temperature. This long-term study gives insight to how the breeding phenology of a passerine migrant is affected by local climatic conditions in the High Arctic. The present study indicates that the dynamics of the study population may be altered with expected climatic warming

К уточнению понимания характеристик рынка труда

Рассмотрены основные характеристики рынка труда. Внесены предложения по их уточнению в соответствии с особенностями формирования регионального рынка труда.Розглянуті основні характеристики ринку праці. Внесено пропозиції по їхньому уточненню відповідно до особливостей формування регіонального ринку праці.Basic descriptions of labour-market are considered. Suggestions on their clarification in accordance with the features of forming of regional labour-market are borne

Young Children's Participation in a Q Study with Visual Images: Some Comments on Reliability and Validity

Inthis study we discuss various aspects of the participation of young children as informants in research relating to their own adjustment and behavior. We ask whether it is meaningful to include young children as participants in this kind of research, and if Q methodology using visualimages is a suitable research method that may give reliable and valid results. An example is given through a study of 20 children aged five. The conclusion is that this may be a suitable approach, and that there are indications that the results are both reliable and valid. However, more research is needed to explore the usefulness of Q methodology with visual images in studies of very young children

Регіональні аспекти удосконалення системи управління персоналом на державній службі

У статті розкривається суть регіональних вимірів удосконалення системи управління персоналом на державній службі та висвітлюється досвід Управління державної служби Головдержслужби України в Миколаївській області на шляху до прозорості влади і залучення громадськості до державотворення.The article reveals the essence of regional measurements of improvement the HR Management system in the civil service and reports the experience of the Office of Civil Service of The Main Department of Civil Service of Ukraine in the Mykolaiv region towards transparency in government and public involvement in the nation

Ethical, Methodological, and Practical Reflections When Using Q Methodology in Research with Young Children

The objective of this discussion is to raise ethical, methodological, and practical issues concerning research with young children and the use of Qmethodology through our experiences with a study of young children's feelings when in situations related to parental divorce. Q methodology was applied with 20 visual statements depicting a range of feelings for five-year-old children from Norwegian daycare centers to sort according to a "How do you generally feel?" condition of instruction. The issues resulting from this work are ethical considerations, methodological reflections, and practical concerns

The dark side of engagement : a study of the curvilinear relationship between work engagement and burnout, and the moderating impact of the motivational climate

Masteroppgave(MSc) in Master of Science in Leadership and Organizational Psychology - Handelshøyskolen BI, 2013This study explores the curvilinear relationship between work engagement and burnout. In addition the study examines whether the perceived psychological motivational climate has an impact on this relationship. The results from our study indicate that there is curvilinear relationship between work engagement and burnout. In addition to finding a linear relationship that goes from negative to positive, our results indicate that there is a curvilinear pattern leading back to negative again. Our study facilitates broader understanding of the important role of the motivational climate in organizations. Our results indicate that mastery climate might act as a positive “buffer” against burnout, however, performance climate may act as a reinforcer of burnout. Our study contributes to a greater understanding of the work engagement concept as well as the relationship between work engagement and burnout. We suggest that managers should encouraging a healthy balance between work and free time by restricting the amount of overtime working. We also call for additional research on the subject that may further clarify the exact tipping point between work engagement and burnout