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Attosecond pulses are central to the investigation of valence- and core-electron dynamics on their natural timescales1–3. The reproducible generation and characterization of attosecond waveforms has been demonstrated so far only through the process of high-order harmonic generation4–7. Several methods for shaping attosecond waveforms have been proposed, including the use of metallic filters8,9, mu
Energiförbrukningen i elektronikprodukter minskar samtidigt som prestandan för solceller hela tiden ökar. Nya solcellstyper med lägre priser skapar nya möjligheter för använding även i små elektronikprodukter. Att samla energi från omgivningen, t.ex. från ljuset i ett rum, och använda det för att driva små elektronikprodukter kallas i ett vidare begrepp för ”energy harvesting” (SV: energiskördningThe power consumption of electronic devices is decreasing at the same time as the performance of solar cells is increasing. Solar cells based on new technologies with lower costs are becoming commercially available, creating new opportunities for use in small electronic products. The concept of capturing ambient energy, such as light, and using it to power small electronic devices is known as ener
Energy harvesting enables products to become more self-sufficient of power and offers the possibility to avoid battery exchange and power cables. The performance and applicability of the most promising or popular small scale energy harvesting technologies are investigated in this thesis. The focus lies on the amount of potential energy that can be harvested and how limited the technology is to a s
In the present study the thermo-hydraulic characteristics of geyser in the cryogenic fuel transportation pipe of a liquid rocket is experimentally investigated using liquid nitrogen. The typical thermo-hydraulic appearances are characterized and analyzed in the geyser process to effectively recognize the occurrence of geyser in practical engineering. The effect of interfering factors such as heat
https://www.iea.lth.se/en/about - 2026-06-05
In this paper, we analyse community energy (CE) projects in urban settings. Building on insights from the literature on the geography of sustainability transitions, we examine how contextual conditions promote or hinder the development of CE. Furthermore, reflecting on calls for greater attention to agency in transitions, we investigated how actors engaged in urban CE projects exploit beneficial c
The total area of Uttarakhand is about 53,483 km2, where 86% area is mountainous and 65% is covered by forest. The two main rivers Ganga and Yamuna originate from Uttarakhand. In addition to these two rivers, Uttarakhand has a large river and canal network that provides hydropower with immense reach. In 1907, one of India’s first hydropower stations was commissioned at Galogi (Uttarakhand). At p
Alunskiffer är en svart lersten av kambrisk-tidig ordovicisk ålder som har en vid utbredning i Sverige och angränsande områden. Bergarten är rik på organiskt kol från ofullständig nedbrytning av marina mikroskopiska organismer som inlagrades i sedimentet på syrefria havsbottnar. Miljön gjorde det även gynnsamt för en del spårmetaller att deponeras, bland annat Uran, Nickel, Molybden och Vanadin. VExploitation of alum shale is a controversial subject in Sweden due to the history of pollution of the environment and groundwater, from past mining industries. The extraction of vanadium from alum shale is no different. Nevertheless the metal is a valuable resource used in tools, building, industries and aerospace materials. A look to the future reveals that vanadium may play a role in renewable
The world production of paper and paperboard products, which increased 3.3% per year since 1980, reached 243 million tonnes in 1991 and is expected to continue to grow by about 2.5% per year over the next decade. Consumption levels in 1990 ranged from 2.8 kg per capita in India to 313 kg per capita in the United States. The biggest producers of pulp are the United States, Canada and the Scandinavi
Experiences early in life strongly shape values, attitudes and behaviour and serve as reference points ever after. Those who grew up in a society where resources are scarce may behave differently in an affluent society than those who got used to affluence even as children. This hypothesis was tested among 600 households in a major Swedish city who responded to questions about energy related behavi
With growing urbanization and increase in energy demand for space heating and cooling in buildings, reliability, security, distribution of energy and its efficient end use is of utmost importance particularly when emissions from energy use and indoor thermal comfort of the end users isof question. Numerous solutions have been put forth in the field of effective distribution of thermal energy to me
After a historic introduction, today's wind power technology is reviewed on a systems level, with some details, and with some brave suggestions for wind technology 2030 when power electronics (PE) will be some 2000 GW. Eternal themes like "electricity storage" are avoided. Aspects of drive-trains in towers and collection grids in parks are concisely described in the paper's core, including: 1) a p
Alberta’s energy sector provides a reliable supply of energy and contributes to the economy of Alberta. In addition to these positive aspects, there are concerns about the environmental, economic and social performance of the energy sector. The purpose of this thesis is to critically examine the production side of Alberta’s energy sector and offer constructive ideas about how the sector could be b
