York scientists unlock secrets of stars through aluminium
Physicists at the University of York have revealed a new understanding of nucleosynthesis in stars, providing insight into the role massive stars play in the evolution of the Milky Way and the origins of the Solar System
2015-07-29
(Press-News.org) Physicists at the University of York have revealed a new understanding of nucleosynthesis in stars, providing insight into the role massive stars play in the evolution of the Milky Way and the origins of the Solar System.
Radioactive aluminium (aluminium-26, or Al26) is an element that emits gamma radiation through its decay enabling astronomers to image its location in our galaxy. Studying how Al26 is created in massive stars, scientists have distinguished between previously conflicting assumptions about its rate of production by nuclear fusion.
Funded by the Science and Technologies Research Council (STFC), scientists measured the fusion of helium and sodium at two separate particle accelerators in Canada and Denmark, and the rate of production of Al26 was determined to within a factor of two. An improvement on previous experiments where there was disagreement of around a factor of 100 between measurements, this outcome removes dispute about the effect of sodium fusion on the rate of aluminium production.
Al26 is known for its relatively short lifespan (in astrophysical terms), decaying in around 1 million years, compared with the lifetime of massive stars of about 19 million years. This means we are now able to better understand gamma radiation maps of the galaxy, observed by space telescopes such as INTEGRAL and COMPTEL, and deduce a more accurate picture of recent activities of massive stars in the galaxy.
Evidence of Al26 decay observed in meteorites and pre-solar grains also suggests that material from massive stars contaminated the gas cloud from which the Solar System formed, providing insight into its early existence.
Dr Alison Laird, Reader in the University of York's Department of Physics and lead author on one of the two research papers, said: "This research highlights clear and unambiguous evidence from gamma-ray observations of the galaxy that nucleosynthesis is happening in stars. By pinning down the production rate of radioactive aluminium, we will be able to interpret and understand these observations.
"Now we better understand the processes within stars that drive aluminium production, we pave the way for more detailed and thorough research into how massive stars affect our galaxy and the origins of our Solar System."
Dr Christian Diget, Lecturer in Nuclear Astrophysics in York's Department of Physics and a lead researcher on the second research paper, said: "These two experiments, completely independent of each other at a technical level and using opposite methodology, provide the most definitive research we have to date of radioactive aluminium production. Through this, we can now much better understand where and how aluminium-26 is produced in stars, and can simulate in the lab how stars work.
"By observing aluminium decay through gamma-radiation maps, we are now able to build a more accurate picture of the conditions when our Solar System formed."
INFORMATION:
ELSE PRESS RELEASES FROM THIS DATE:
2015-07-29
University of Adelaide research has shown for the first time that, despite not having a nervous system, plants use signals normally associated with animals when they encounter stress.
Published today in the journal Nature Communications, the researchers at the Australian Research Council (ARC) Centre of Excellence in Plant Energy Biology reported how plants respond to their environment with a similar combination of chemical and electrical responses to animals, but through machinery that is specific to plants.
"We've known for a long-time that the animal neurotransmitter ...
2015-07-28
Bari, Italy, July 28, 2015 -- A new study by researchers at the University of Bari Aldo Moro, Bari, Italy, Geriatric Unit & Laboratory of Gerontology and Geriatrics, IRCCS "Casa Sollievo della Sofferenza", San Giovanni Rotondo, Foggia, Italy, and Istituto Superiore di Sanità (ISS), Roma, Italy, estimates the association between change or constant habits in coffee consumption and the incidence of mild cognitive impairment (MCI), evaluating 1,445 individuals recruited from 5,632 subjects, aged 65-84 year old, from the Italian Longitudinal Study on Aging (ILSA), a population-based ...
2015-07-28
Rewritable CDs, DVDs and Blu-Ray discs owe their existence to phase-change materials, those materials that change their internal order when heated and whose structures can be switched back and forth between their crystalline and amorphous phases. Phase-change materials have even more exciting applications on the horizon, but our limited ability to precisely control their phase changes is a hurdle to the development of new technology.
One of the most popular and useful phase-change materials is GST, which consists of germanium, antimony, and tellurium. This material is ...
2015-07-28
Hercules, CA -- July 28, 2015 -- Droplet Digital PCR (ddPCR™) has been shown to be a useful tool for the identification of microRNAs (miRNA) circulating in the blood that could serve as potential cancer biomarkers. A study in the journal Oncotarget further supports these findings and identifies a novel miRNA that shows great potential for breast cancer diagnosis. These findings confirm the potential clinical utility of ddPCR technology to precisely and reliably quantify cell-free miRNAs. The study also emphasizes that sample type as well as its preparation are critical ...
2015-07-28
ANN ARBOR--Secondary students found healthier foods on more lunch menus in 2013 than in 2011, resulting in fewer nutrition disparities for small schools or those with racially diverse student bodies.
The findings by University of Michigan researchers show significant improvements made in the National School Lunch Program at public middle and high schools in 2013 after many years of meal disparities based on school size or demographics.
"While these improvements are encouraging, continued progress is needed," said Yvonne Terry-McElrath, a researcher at the U-M Institute ...
2015-07-28
Wild chimpanzees in the forests of Uganda are increasingly eating clay to supplement the minerals in their diet, according to a long-term international study published in the early version of the journal PLOS ONE. The paper led by the University of Oxford describes how the researchers observed wild chimpanzees in the Budongo forest eating and drinking from clay pits and termite mounds. The paper concludes that this change in diet may be partly due to the widespread destruction of raffia palm trees that chimps relied on for their minerals in the past. However, the main reason ...
2015-07-28
(SACRAMENTO, Calif.) -- UC Davis health economists have for the first time projected the total costs of caring for all people with autism spectrum disorder (ASD) in the U.S. for the current calendar year and in 10 years if effective interventions and preventive treatments for the condition are not identified and widely available.
Their forecasts for ASD-related medical, nonmedical and productivity losses are $268 billion for 2015 and $461 billion for 2025. The researchers noted that these estimates are conservative and, if ASD prevalence continues to increase as it has ...
2015-07-28
The continuous quality improvement (CQI) approach was introduced on a pilot basis to 30 sites across Uganda. This approach identified barriers in achieving national standards for voluntary medical male circumcision (VMMC), identified possible solutions to overcome these barriers, and carried out improvement plans to test these changes while collecting performance data to objectively measure whether they had bridged gaps.
Teams used a 53-indicator quality assessment tool adapted by the Ministry of Health and based on the WHO VMMC Quality Toolkit as a management tool to ...
2015-07-28
Surgeons at The Children's Hospital of Philadelphia (CHOP) joined with colleagues from Penn Medicine recently to complete the world's first bilateral hand transplant on a child. Earlier this month, the surgical team successfully transplanted donor hands and forearms onto eight-year-old Zion Harvey who, several years earlier, had undergone amputation of his hands and feet and a kidney transplant following a serious infection.
Led by L. Scott Levin, M.D., FACS*, Chairman of the Department of Orthopaedic Surgery at Penn Medicine, Director of the Hand Transplantation Program ...
2015-07-28
Whether online auctions are selling rare Pokemon cards or fine art, the science behind inciting the highest bids gets a boost from a paper to be published in the September issue of the Journal of Retailing. Researchers from Germany and Australia teamed up to explore how bidders' emotions are affected by different types of auctions and how those emotions affect their bidding.
In "Auction Fever! How Time Pressure and Social Competition Affect Bidders' Arousal and Bids in Retail Auctions," the three authors - Marc T.P. Adam of the University of Newcastle, Professor ...
LAST 30 PRESS RELEASES:
[Press-News.org] York scientists unlock secrets of stars through aluminium
Physicists at the University of York have revealed a new understanding of nucleosynthesis in stars, providing insight into the role massive stars play in the evolution of the Milky Way and the origins of the Solar System
