1,212 research outputs found
Antisymmetric tensor contribution to the muon g-2
We investigate the Kalb-Ramond antisymmetric tensor field as solution to the
muon problem. In particular we calculate the lowest-order Kalb-Ramond
contribution to the muon anomalous magnetic moment and find that we can fit the
new experimental value for the anomaly by adjusting the coupling without
affecting the electron anomalous magnetic moment results.Comment: 7 pages, 1 figur
Radiolysis of Amino Acids by Heavy and Energetic Cosmic Ray Analogs in Simulated Space Environments: -Glycine Zwitterion Form
In this work, we studied the stability of the glycine molecule in the
crystalline zwitterion form, known as {\alpha}-glycine
(NHCHCOO) under action of heavy cosmic ray analogs. The
experiments were conducted in a high vacuum chamber at heavy ions accelerator
GANIL, in Caen, France. The samples were bombarded at two temperatures (14 K
and 300 K) by Ni ions of 46 MeV until the final fluence of
ions cm. The chemical evolution of the sample was evaluated
in-situ using Fourrier Transformed Infrared (FTIR) spectrometer. The
bombardment at 14 K produced several daughter species such as OCN, CO,
CO, and CN. The results also suggest the appearing of peptide bonds
during irradiation but this must be confirmed by further experiments. The
halflives of glycine in Interstellar Medium were estimated to be 7.8 years (300 K) and 2.8 years (14 K). In the Solar System the
values were 8.4 years (300 K) and 3.6 years (14 K).
It is believed that glycine could be present in space environments that
suffered aqueous changes such as the interior of comets, meteorites and
planetesimals. This molecule is present in proteins of all alive beings. So,
studying its stability in these environments provides further understanding
about the role of this specie in the prebiotic chemistry on Earth.Comment: 28 pages, 12 figures, 9 tables. Accepted to be published at Monthly
Notices of the Royal Astronomical Society (MNRAS
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Disabled people and the Internet: experiences, barriers and opportunities
The UK government aims to make all its information and transactions available electronically by 2005. General use of the Internet also continues to grow. This report investigates the Internet's barriers and benefits for disabled people, and considers whether it acts as a means to reduce their social exclusion.
The study surveys the views and experiences of disabled people, both Internet users and non-users. Topics covered include: what the Internet is used for; use of and difficulties with assistive devices (special equipment and adaptations needed by some disabled people in order to use computers); how people learn to use the Internet; views of website accessibility; advantages and disadvantages of Internet usage.
It also explores participants' restrictions on using the Internet, and people's reasons for not using it. There has been little previous research in this area, but the authors review the existing literature. The report finds that many practical problems - such as the cost of training, finding appropriate assistive devices, website accessibility - all inhibit Internet opportunities for many disabled people
Employing Soft X-rays in Experimental Astrochemistry
The presence of soft x-rays is very important for the chemical evolution of
interstellar medium and other astrophysical environments close to young and
bright stars. Soft X-rays can penetrate deep in molecular clouds and
protostellar disks and trigger chemistry in regions in which UV stellar photons
do not reach. The effects of soft X-rays in astrophysical ices are also
remarkable because they release secondary electrons in and on the surface of
the ices, which trigger a new set or chemical reactions. In this chapter we
will discuss firstly about the origin and relevance of soft X-rays in
astrophysics. Next we will move to the effect of ionizing radiation in organic
molecules present in astrophysical environment. We will discuss the use soft
X-rays in astrochemistry laboratory studies at both gas- and solid-phase (ice).
We will make a review covering our publications in this field, in particular,
about the experiments employing time-of-flight spectroscopy (TOF-MS), Fourier
transform infrared (FTIR) spectroscopy and photon stimulated ion desorption
(PSID-TOF-MS). This study help us to understand the chemical evolution several
astrophysical regions and also put constrains in the researches related with
the life's origin.Comment: 34 pages, 25 figures and 2 tables. This a book chapter of "X-Ray
Spectroscopy" ISBN:978-953-307-967-7; InTech Open Access Publisher
(http://www.intechweb.org/). Edited by Shatendra K. Sharma. Publication date:
December 201
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