3,207 research outputs found
Particle yields in heavy ion collisions and the influence of strong magnetic fields
It is expected that the magnetic field in the surface of magnetars do not
exceed G. However, in heavy ion collisions, this value is expected to
be much higher. We investigate the effects of a magnetic fields varying from
, to G in strange matter (composed of , and
quarks). We model matter as a free gas of baryons and mesons under the
influence of an external magnetic field. We study the effects of such strong
fields through a fit to some data sets of the STAR experiment. For
this purpose we solve the Dirac, Rarita-Schwinger, Klein-Gordon and Proca
equations subject to magnetic fields in order to obtain the energy expressions
and the degeneracy for spin 1/2, spin 3/2, spin 0 and spin 1 particles,
respectively. Our results show that a field of the order of G
produces an improved fitting to the experimental data as compared to the
calculations without magnetic field.Comment: 20 pages, 16 figures, 4 table
Comparison of upper body strength gains between men and women after 10 weeks of resistance training
Resistance training (RT) offers benefits to both men and women. However, the studies about the differences between men and women in response to an RT program are not conclusive and few data are available about upper body strength response. The aim of this study was to compare elbow flexor strength gains in men and women after 10 weeks of RT. Forty-four college-aged men (22.63 +/- 2.34 years) and forty-seven college-aged women (21.62 +/- 2.96 years) participated in the study. The RT program was performed two days a week for 10 weeks. Before and after the training period, peak torque (PT) of the elbow flexors was measured with an isokinetic dynamometer. PT values were higher in men in comparison to women in pre-and post-tests (p 0.05). Effect sizes were 0.57 and 0.56 for men and women, respectively. In conclusion, the present study suggests that men and women have a similar upper body strength response to RT
On some properties of quasi-MV algebras and square root quasi-MV algebras, IV
In the present paper, which is a sequel to
[20, 4, 12], we investigate further the structure theory of quasiMV
algebras and √0quasi-MV algebras. In particular: we provide
a new representation of arbitrary √0qMV algebras in terms
of √0qMV algebras arising out of their MV* term subreducts of
regular elements; we investigate in greater detail the structure
of the lattice of √0qMV varieties, proving that it is uncountable,
providing equational bases for some of its members, as well as
analysing a number of slices of special interest; we show that the
variety of √0qMV algebras has the amalgamation property; we
provide an axiomatisation of the 1-assertional logic of √0qMV
algebras; lastly, we reconsider the correspondence between Cartesian
√0qMV algebras and a category of Abelian lattice-ordered
groups with operators first addressed in [10]
η1-Allylpalladium complexes with a tridentate PNP ligand with different phosphino groups
The iminodiphosphine 2-(PPh2)C6H4-1-CHvNC6H4-2-(PPh2) (P–N–P′) is used for the preparation of the
complexes [Pd(η1-CHR1–CHvCR2R3)(P–N–P′)]BF4 [R1 = R2 = R3 = H: (1); R1 = R2 = Ph,
R3 = H: (2); R1 = R3 = H, R2 = Ph: (3); R1 = H, R2 = R3 = Me: (4)]. The P–N–P′ tridentate coordination
and the η1-allyl bonding mode in the solid are confirmed by the X-ray structural analysis of 1. In solution,
the complexes 1 and 2 undergo an η1–η3–η1 rearrangement at 298 K interconverting the bonding site of
the allyl group. A five-coordinate structure with the phosphine ligands in the axial position is proposed
for the η3-allyl intermediate. For the dynamic process, a ΔG≠value of 53.8 kJ mol−1 is obtained from
1H NMR data of 2. In 3 and 4, the allyl ligand is rigidly bound to the metal through the less substituted
terminus, in line with the higher free energy content of the corresponding isomers: [Pd(η1-CHPh–
CHvCH2)(P–N–P′)]+ +48.78 kJ mol−1; [Pd(η1-CMe2–CHvCH2)(P–N–P′)]+ +69.35 kJ mol−1. The
complexes react with secondary amines in the presence of fumaronitrile at different rates yielding
allylamines and the palladium(0) derivative [Pd(η2-fn)(P–N–P′)] (5). On the basis of charge distribution
on the allylic carbon atoms and of steric factors, the difference in rate and the regioselectivity in the
amination of 1–3 are better rationalized by a mechanism with nucleophilic attack at the η3-intermediate
rather than by an SN2 mechanism with nucleophilic attack at the Pd–CHR1 carbon atom. The high
regioselectivity in the reaction of 4 with piperidine implies an SN2′ mechanism with nucleophilic attack at
the CMe2 allyl carbon. A dynamic process occurs also for the 18-electron complex 5 consisting in a
dissociation–association equilibrium of the olefin
Participatory design, beyond the local
This workshop aims at stimulating and opening a debate around the capacity of Participatory Design (PD) and other co-design approaches to deliver outcomes and methodologies that can have an impact and value for reuse well beyond the local context in which they were originally developed. This will be achieved by stimulating the submission of position papers by researchers from the PD community and beyond.These papers will be discussed during the workshop in order to identify challenges, obstacles but also potentials for scaling up PD processes and results from the local to the global.</p
Catadioptric stereo-vision system using a spherical mirror
Abstract In the computer vision field, the reconstruction of target surfaces is usually achieved by using 3D optical scanners assembled integrating digital cameras and light emitters. However, these solutions are limited by the low field of view, which requires multiple acquisition from different views to reconstruct complex free-form geometries. The combination of mirrors and lenses (catadioptric systems) can be adopted to overcome this issue. In this work, a stereo catadioptric optical scanner has been developed by assembling two digital cameras, a spherical mirror and a multimedia white light projector. The adopted configuration defines a non-single viewpoint system, thus a non-central catadioptric camera model has been developed. An analytical solution to compute the projection of a scene point onto the image plane (forward projection) and vice-versa (backward projection) is presented. The proposed optical setup allows omnidirectional stereo vision thus allowing the reconstruction of target surfaces with a single acquisition. Preliminary results, obtained measuring a hollow specimen, demonstrated the effectiveness of the described approach
The Rarita-Schwinger Particles Under de Influence of Strong Magnetic Fields
In this work, we calculate the solutions of the Rarita-Schwinger equation
with the inclusion of the eletromagnetic interaction. Our gauge and coupling
prescription choices lead to Dirac-type solutions. One of the consequences of
our results are the Landau level occupation of particles, quite different from
the usual spin 1/2 particle system occupation numbers.Comment: 12 page
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