3,097 research outputs found
The role of field redefinition on renormalisability of a general supersymmetric gauge theories
We investigate some issues on renormalisability of non-anticommutative
supersymmetric gauge theory related to field redefinitions. We study one loop
corrections to supersymmetric gauge theory
coupled to chiral matter in component formalism, and show the procedure which
has been introduced for renormalisation is problematic because some terms which
are needed for the renormalisability of theory are missed from the Lagrangian.
In order to prove the theory is renormalisable, we redefine the gaugino and the
auxiliary fields(), which result in a modified form of the
Lagrangian in the component formalism. Then, we show the modified Lagrangian
has extra terms which are necessary for renormalisability of
non-anticommutative supersymmetric gauge field theories. Finally we prove supersymmetric gauge theory is renormalisable up to one loop
corrections using standard method of renormalisation; besides, it is shown the
effective action is gauge invariant.Comment: arXiv admin note: text overlap with arXiv:hep-th/0505248 by other
author
Transverse expansion of hot magnetized Bjorken flow in heavy ion collisions
We argue that the existence of an inhomogeneous external magnetic field can
lead to radial flow in transverse plane. Our aim is to show how the
introduction of a magnetic field generalizes the Bjorken flow. We investigate
the effect of an inhomogeneous weak external magnetic field on the transverse
expansion of in-viscid fluid created in high energy nuclear collisions. In
order to simplify our calculation and compare with Gubser model, we consider
the fluid under investigation to be produced in central collisions, at small
impact parameter; azimuthal symmetry has been considered. In our model, we
assume an inhomogeneous external magnetic field following the power-law decay
in proper time and having radial inhomogeneity perpendicular to the radial
velocity of the in-viscid fluid in the transverse plane; then the space time
evolution of the transverse expansion of the fluid is obtained. We also show
how the existence of an inhomogeneous external magnetic field modifies the
energy density. Finally we use the solutions for the transverse velocity and
energy density in the presence of a weak magnetic field, to estimate the
transverse momentum spectrum of protons and pions emerging from the
Magneto-hydrodynamic solutions
Non-relativistic approximate numerical ideal-magneto hydrodynamics of (1+1) D transverse flow in Bjorken scenario
In this study, we investigate the impact of the magnetic field on the
evolution of the transverse flow of QGP matter in the magneto-hydrodynamic
(MHD) framework. We assume that the magnetic field is perpendicular to the
reaction plane and then we solve the coupled Maxwell and conservation equations
in (1+1D) transverse flow, within the Bjorken scenario. We consider a QGP with
infinite electrical conductivity. First, the magnetic effects on the QGP medium
at mid-rapidity are investigated at leading order; then the time and space
dependence of the energy density, velocity and magnetic field in the transverse
plane of the ideal magnetized hot plasma are obtained
Are inexpensive surveys for maintenance management of small existing residential buildings at BIM level 2?”
BIM for maintenance management is still in its infancy, despite the advertised advantages it could bring. There are several barriers to overcome, mainly an understanding by those who will need to use it on a daily basis. Several issues have been identified that have prevented mainstream acceptance of the technology, especially when dealing with existing buildings.
New buildings have the advantage that a 3d virtual model exists, having been developed during the design and construction phases, but for existing buildings, surveys need to be carried out and a 3d model developed. Such techniques have seen exciting results where large corporations have had the finance to commission such a survey, but are proving too expensive for small exiting residential properties, especially those managed by local authorities and housing associations.
Some less expensive survey techniques have been tried and tested and compared to the traditional expensive techniques, such as laser scanning. Virtual 3D models of small houses and flats have been ‘built’ and examined to see their potential in the field of maintenance. Levels of details have also been discussed.
The requirement for 3d has been questioned, with floor plans being achieved using a 2d laser scanner (costing less than 1% of a 3d scanner), although the addition of the metadata still seems to be the major barrier in providing a useful model. Photogrammetric technics were tested but proved to still be difficult to use in confined spaces.
The conclusion is there is still a long way to go for the adoption of BIM on existing buildings. Changes to the Governments BIM standards are needed to move away from just ‘new build’ and quicker automatic metadata determination are required to enable BIM to be effectively used for maintenance of existing buildings
PROPERTIES OF METAKAOLIN CONCRETE – A REVIEW
The use of cement supplementary materials in structural concrete is widely accepted by the construction industry for technical, economical and environmental reasons. Metakaolin (MK), produced by calcining kaolinite at high temperature is suitable for concrete production due to its pozzolanic property. This paper reviews the some of the research published on effects of using MK on engineering properties of structural concrete as a cement replacement material. The review shows that the use of relatively finer MK to partially replace cement reduces the consistency of concrete and enhanced the strengths, deformational and durability properties of concrete. MK is most effective in enhancing compressive strength (particularly at early ages) compared to other strengths and modulus of elasticity was least improved. Drying shrinkage and creep of MK concretes are lower than those for the control concrete. The high pozzolanic reactivity of MK with calcium hydroxide contributes to both porosity reduction and pore-structure refinement in the pastes and concrete. As the consequence, the durability of concrete is improved through increased resistance to chloride penetration and controlled expansion, due to alkali-silica reaction and sodium sulphate attack
Poređenje gustine nasda nereis diversicolor u prirodnim i uzgojnim (anzali lagona) uslovima
Nereis diversicolor is regarded as a live food and is significantly effective in increasing stocks, enhancing tolerance in sturgeons and also increasing survival of sturgeon fry. Research conducted indicates that N. diversicolor is more abundant in May as compared to other months of the year. In February, only breeders of this species are found in the environment. N. diversicolor was found in four different weight classes from March 2009 to February 2010. They showed decrease in density with increase in temperature and reached the lowest numbers in February. In years 2009 and 2010, 200 sampling conducted monthly at the point where Caspian Sea mixes with the Anzali lagoon. Sampling was performed by Van Veen sampler with 400 cm2 cross section. Sediments were washed through a sieve with 0.5 mm mesh size. The residue along with Nereis was transferred to a dish, worms separated and transferred to lab. The density of worms per m2 was calculated according to the density formula. Two experiments were conducted to determine the best stocking density for the culture of N. diversicolor. Stocking density of 381-6350 worms m-2 were used in 6 trials initially and best growth was recorded in trial with density of 381 worms m-2. In the second experiment using 381-3175 worms m-2 in 7 trials, trial with 381 worms m-2 again showed better growth as compared to other trials. These results obtained were almost similar to those obtained for N. diversicolor is in its natural environment (447 worms m-2)
Accuracy of Visual inspection with acetic acid (VIA) for early detection of cervical dysplasia in Tehran, Iran
Objective: To evaluate the accuracy of visual inspection with 5 acetic acid (VIA) when used to detect cervical cancer and its precursors. Methods: The study population included women attended Family Planning and Gynecological Clinic in Bagher Abad Health Center and Mirza Koochak Khan Hospital for regular cervical screening tests. After obtaining informed consent from each woman, VIA was performed. One hundred with a positive VIA test and 100 women with a negative VIA test were randomly selected for this study. Cytology and colposcopy examination were performed for all 200 cases and cervical biopsies were conducted for those individuals showing abnormal colposcopic findings. Results: Nine cases in VIA-positive group and two cases in VIA-negative group had an abnormal cytology. Ninety five women in the VIA-positive group and 25 in the VIA-negative group had abnormal colposcopic findings. From biopsy examination, 67 (71) of cases in the VIA-positive group and 3 (12) cases in the VIA-negative group had a final diagnosis of dysplasia. Among biopsied samples, only 7 cases of VIA-positive group showed abnormal result and the remaining were normal. Based on these results, VIA test sensitivity and specificity were 95.7 and 44.0 respectively, while they were 10 and 92 for cytology tests. Conclusions: The results of this study indicate that although VIA is a sensitive screening test for detection of cervical dysplasia, it can not be used by itself. Applying VIA along with Pap smears helps to detect a higher number of cases with cancer precursor lesions
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