다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

비만아 부모의 돌봄 경험: q 방법론

Advances in atomic physics, such as cooling and trapping of atoms and molecules and developments in frequency metrology, have added orders of magnitude to the precision of atom-based clocks and sensors. Applications extend beyond atomic physics and this article reviews using these new techniques to address important challenges in physics and to look for variations in the fundamental constants, search for interactions beyond the standard model of particle physics, and test the principles of general relativity.

Search for New Physics with Atoms and Molecules

Smart Energy Systems for coherent 100% renewable energy and transport solutions

Long-term patterns of European PV output using 30 years of validated hourly reanalysis and satellite data

Thermo-mechanical energy storage can be a cost-effective solution to provide flexibility and balance highly renewable energy systems. Here, we present a concise review of emerging thermo-mechanical energy storage solutions focusing on their commercial development. Under a unified framework, we review technologies that have proven to work conceptually through project demonstration at a scale above 1 MW by describing the current state of commercial development, quantifying techno-economic parameters, outlining the challenges, and assessing each technology’s potential for commercial viability. The levelized cost of storage for thermo-mechanical energy storage at storage duration between 8 h and 1 week is cheaper than that of lithium-ion batteries and hydrogen storage; however, energy storage for such duration does not pay for itself at the current renewable penetration levels. For medium-term energy storage to be viable, at the realistic storage cost of 15 USD/kWh to 40 USD/kWh, the investment cost for power components should decrease to one-fifth of the current costs. Thermo-mechanical energy storage can be economically viable at the current investment costs in off-grid systems only when the marginal cost of alternative fuel exceeds 100 USD/MWh. We identified the cost ratio (charge power cost/discharge power cost) and the discharge efficiency as the critical technology-related performance parameters. Other external factors such as wind and solar fractions, demand, interconnections, sector coupling, and market structure play an important role in determining the economic feasibility of thermo-mechanical energy storage.

/pdf/review-and-techno-economic-analysis-of-emerging-thermo-39ojwosc.pdf

Review and Techno-Economic Analysis of Emerging Thermo-Mechanical Energy Storage Technologies

A global electricity grid may offer a number of advantages in a future highly renewable energy system dominated by wind and solar power. In this paper, we provide quantitative estimates for the benefits and costs of an intercontinental HVDC grid connecting a number of highly populated super regions in the Northern Hemisphere. The modeling is based on hourly time series of wind and solar power generation calculated from high-resolution global weather data using the Global Renewable Energy Atlas. Taking a European point of view, we find that the annual need for backup energy can be reduced from 18 to 10 % of the load by connecting to North Africa, the Middle East and Russia. A further reduction to 7 % is found for a grid spanning the whole Northern Hemisphere at the expense of substantial increase in transmission capacities. Comparing the economical benefits to the additional cost of intercontinental transmission lines, we estimate that connecting Europe to its geographically nearest neighbors may reduce the total cost of electricity. Longer distance connections to North America or Asia, on the other hand, would require transmission costs to fall to 15–20 % of current levels.

Infrastructure Estimates for a Highly Renewable Global Electricity Grid

Evaporative cooling of antiprotons and efforts to trap antihydrogen

In many antihydrogen trapping schemes, antiprotons held in a short-well Penning–Malmberg trap are released into a longer well This process necessarily causes the bounce-averaged rotation frequency Ω¯r of the antiprotons around the trap axis to pass through zero In the presence of a transverse magnetic multipole, experiments and simulations show that many antiprotons (over 30% in some cases) can be lost to a hitherto unidentified bounce-resonant process when Ω¯r is close to zero

http://raman.physics.berkeley.edu/papers/PhysPlasmas_16_100702.pdf

Magnetic multipole induced zero-rotation frequency bounce-resonant loss in a Penning-Malmberg trap used for antihydrogen trapping

Space heating in buildings is becoming a key element of sector-coupled energy system research. Data availability limits efforts to model the buildings sector, because heat consumption is not directly metered in most countries. Space heating is often related to weather through the proxy of heating degree-days using a specific heating threshold temperature, but methods vary between studies. This study estimates country-specific heating threshold temperatures using widely and publicly available consumption and weather data. This allows for national climate and culture-specific human behaviour to be captured in energy systems modelling. National electricity and gas consumption data are related to degree-days through linear models, and Akaike's Information Criteria is used to define the summer season in each country, when space heating is not required. We find that the heating threshold temperatures computed using daily, weekly and monthly aggregated consumption data are statistically indifferent. In general, threshold temperatures for gas heating centre around 15.0 +/- 1.7 degree C (daily averaged temperature), while heating by electricity averages to 13.4 +/- 2.4 degree C. We find no evidence of space heating during June, July and August, even if heating degree-days are present.

Gorm Bruun Andresen

Papers

Review and Techno-Economic Analysis of Emerging Thermo-Mechanical Energy Storage Technologies

Infrastructure Estimates for a Highly Renewable Global Electricity Grid

Evaporative cooling of antiprotons and efforts to trap antihydrogen

Magnetic multipole induced zero-rotation frequency bounce-resonant loss in a Penning-Malmberg trap used for antihydrogen trapping

Estimating country-specific space heating threshold temperatures from national consumption data