Results 61 to 70 of about 3,439,333 (263)

Properties of sunspots in cycle 23 [PDF]

Astronomy & Astrophysics, 2007
In this paper we investigate the dependence of umbral core brightness, as well as the mean umbral and penumbral brightness on the phase of the solar cycle and on the size of the sunspot. Albregtsen & Maltby (1978) reported an increase in umbral core brightness from the early to the late phase of solar cycle from the analysis of 13 sunspots which ...
Mathew, S., Martínez Pillet, V., Solanki, S., Krivova, N.   +3 more
openaire   +3 more sources

Beyond the Ban—Shedding Light on Smallholders' Price Vulnerability in Indonesia's Palm Oil Industry

Applied Economic Perspectives and Policy, EarlyView.
ABSTRACT The Indonesian government imposed a palm oil export ban in April 2022 to address rising cooking oil prices. This study explores oil palm smallholders' vulnerability to the policy using descriptive statistics, Lasso, and post‐Lasso OLS regressions.
Charlotte‐Elena Reich, Tim Ölkers, Vanessa Bonke, Oliver Musshoff   +3 more
wiley   +1 more source

A 22-year cycle in the F layer ionization of the ionosphere [PDF]

Annales Geophysicae, 1997
The double-sunspot-cycle variation in terrestrial magnetic activity has been well known for about 30 years. In 1990 we examined and compared the low-solar-activity (LSA) part of two consecutive cycles and predicted from this database and from ...
E. Feichter, R. Leitinger
doaj   +1 more source

Level and length of cyclic solar activity during the Maunder minimum as deduced from the active day statistics

, 2015
The Maunder minimum (MM) of greatly reduced solar activity took place in 1645-1715, but the exact level of sunspot activity is uncertain as based, to a large extent, on historical generic statements of the absence of spots on the Sun.
Carrasco, V. M. S., Gallego, M. C., Kovaltsov, G. A., Usoskin, I. G., Vaquero, J. M.   +4 more
core   +1 more source

Biodegradable and Bioinspired UV Light Recognition via Sustainable Synaptic Transistors for Artificial Intelligence Vision Systems

Advanced Intelligent Systems, EarlyView.
We report a biodegradable electrolyte‐gated synaptic phototransistor that combines low‐power UV sensing with memory functionality, offering a sustainable platform for AI vision systems and health‐monitoring technologies. Presented here is a biodegradable, bioinspired synaptic phototransistor (SPT) based on an electrolyte‐gated field‐effect transistor ...
Theodoros Serghiou, Rogério Morais, Douglas Henrique Vieira, Neri Alves, Roghaieh Parvizi, Jeff Kettle   +5 more
wiley   +1 more source

A perspective from the Mesozoic: Evolutionary changes of the mammalian skull and their influence on feeding efficiency and high‐frequency hearing

The Anatomical Record, EarlyView.
Abstract The complex evolutionary history behind modern mammalian chewing performance and hearing function is a result of several changes in the entire skeletomuscular system of the skull and lower jaw. Lately, exciting multifunctional 3D analytical methods and kinematic simulations of feeding functions in both modern and fossil mammals and their ...
Julia A. Schultz
wiley   +1 more source

The sunspot cycle revisited [PDF]

Journal of Physics: Conference Series, 2013
The set of sunspot numbers observed since the invention of the telescope is one of the most studied time series in astronomy and yet it is also one of the most complex. Fourteen frequencies are found in the yearly mean sunspot numbers from 1700 to 2011using the Lomb-Scargle periodogram and prewhitening.
openaire   +1 more source

Why does the sun's torsional oscillation begin before the sunspot cycle? [PDF]

Physical Review Letters, 2009
Although the Sun's torsional oscillation is believed to be driven by the Lorentz force associated with the sunspot cycle, this oscillation begins 2-3 yr before the sunspot cycle.
S. Chakraborty, A. Choudhuri, P. Chatterjee   +2 more
semanticscholar   +1 more source

Chlorella vulgaris biorefineries: sustainable biofuels and high‐value carbon capture

Biofuels, Bioproducts and Biorefining, EarlyView.
Abstract Global reliance on fossil fuels has created urgent economic and environmental challenges, yet large‐scale use of algal biomass remains limited by production costs. Industrial scaling is constrained by inefficient harvesting and the technical challenges of processing recalcitrant cell walls.
Sandyelle Ferreira Alcântara Araújo, Antonio Átila Menezes Ferreira, Lucia Andrea Sindeaux de Oliveira, Dayana Nascimento Dari, Devany Quintela Soares, Eliana Elisa Francelino Mavie, Francisco Leonardo Alves de Moraes Sousa, Jessica Lopes da Silva, João Vitor Gomes de Araújo Silva, Thiago Queiroz da Silva, Ana Karine Portela Vasconcelos, Kelma Maria dos Santos Pires Cavalcante, John Hebert da Silva Felix, José Cleiton Sousa dos Santos   +13 more
wiley   +1 more source

Modeling the Sunspot Number Distribution with a Fokker-Planck Equation

, 2011
Sunspot numbers exhibit large short-timescale (daily-monthly) variation in addition to longer timescale variation due to solar cycles. A formal statistical framework is presented for estimating and forecasting randomness in sunspot numbers on top of ...
Noble, Patrick, Wheatland, Mike
core   +1 more source