1,354 research outputs found
Singled Out: A Critique of the Representation of Single Motherhood in Welfare Discourse
Baby Skyrme models for a class of potentials
We consider a class of (2+1) dimensional baby Skyrme models with potentials
that have more than one vacum. These potentials are generalisation of old and
new baby Skyrme models;they involve more complicated dependence on phi_3.We
find that when the potential is invariant under phi_3 -> -phi_3 the
configuration corresponding to the baby skyrmions lying "on top of each other"
are the minima of the energy. However when the potential breaks this symmetry
the lowest field configurations correspond to separated baby skyrmions. We
compute the energy distributions for skyrmions of degrees between one and eight
and discuss their geometrical shapes and binding energies. We also compare the
2-skyrmion states for these potentials. Most of our work has been performed
numerically with the model being formulated in terms of three real scalar
fields (satisfying one constraint).Comment: LaTeX, 14 pages, 10 figure
New MAX Phase Compound Mo2TiAlC2: First-principles Study
A theoretical study of Mo2TiAlC2 compound belonging to the MAX phases has
been performed by using the firstprinciples pseudopotential plane-wave method
within the generalized gradient approximation. We have calculated the
structural, elastic, electronic and optical properties of Mo2TiAlC2. To confirm
mechanical stability, the elastic constants Cij are calculated. Other elastic
parameters such as bulk modulus, shear modulus, compressibility, Young modulus,
anisotropic factor, Pugh ratio, Poisson ratio are also calculated. The energy
band structure and density of states are calculated and analyzed. The results
show that the electrical conductivity is metallic with a high density of states
at the Fermi level in which Mo 4d states dominate. Furthermore, the optical
properties such as dielectric function, refractive index, photoconductivity,
absorption coefficients, loss function and reflectivity are also calculated.
Its reflectance spectrum shows that it has the potential to be used as a
promising shielding material to avoid solar heating.Comment: 9 page
Simulation of Traffic Flow Model with Traffic Controller Boundary
This paper considers a fluid dynamic traffic flow model appended with a closure linear velocity-density relationship which provides a first order hyperbolic partial differential equation (PDE) and is treated as an initial boundary value problem (IBVP). We consider the boundary value in such a way that one side of highway treat like there is a traffic controller at that point. We present the analytic solution of the traffic flow model as a Cauchy problem. A numerical simulation of the traffic flow model (IBVP) is performed based on a finite difference scheme for the model with two sided boundary conditions and a suitable numerical scheme for this is the Lax-Friedrichs scheme. Solution figure from our scheme indicates a desired result that amplitude and frequency of cars density and velocity reduces as time grows. Also at traffic controller point, velocity and density values change as desired manner. In further, we also want to introduce anisotropic behavior of cars(to get more realistic picture) which has not been considered here.
Doi: 10.12777/ijse.5.1.25-30
[How to cite this article: Sultana, N., Parvin, M. , Sarker, R., Andallah, L.S. (2013). Simulation of Traffic Flow Model with Traffic Controller Boundary. International Journal of Science and Engineering, 5(1),25-30. Doi: 10.12777/ijse.5.1.25-30
Validity and worth in the science curriculum: learning school science outside the laboratory
It is widely acknowledged that there are problems with school science in many developed countries of the world. Such problems manifest themselves in a progressive decline in pupil enthusiasm for school science across the secondary age range and the fact that fewer students are choosing to study the physical sciences at higher levels and as careers. Responses to these developments have included proposals to reform the curriculum, pedagogy and the nature of pupil discussion in science lessons. We support such changes but argue from a consideration of the aims of science education that secondary school science is too rooted in the science laboratory; substantially greater use needs to be made of out-of-school sites for the teaching of science. Such usage should result in a school science education that is more valid and more motivating and is better at fulfilling defensible aims of school science education. Our contention is that laboratory-based school science teaching needs to be complemented by out-of-school science learning that draws on the actual world (e.g. through fieldtrips), the presented world (e.g. in science centres, botanic gardens, zoos and science museums) and the virtual worlds that are increasingly available through information and communications technologies (ICT)
Responses of salivary cortisol and α-amylase to official competition
This study was designed to determine the relationship between salivary cortisol, α-amylase and total protein response in the official football players during the course of a game. Nine young amateur football players agreed to participate in the study. Saliva samples were collected from each player 30 min and 5 min before the start of the competition, at half time, and then again 5 and 30 min after the end of competition. A significant increase in cortisol (p=0.04) in response to playing the competition was observed including a significantly higher concentration 30 min after match as compared to half time (p=0.016). In contrast, changes in salivary α-amylase changes were irregular, but there was significant decline 5 min after end of match as compared to the 5 min before the beginning of match (p<0.019). No significant difference in total protein concentration was observed. Though salivary cortisol, α-amylase and total protein changes were observed concomitantly, but there no significant relationship between them. We conclude that participation in competition has an accumulative effect on salivary cortisol concentration, but this was not related changes in salivary α-amylase
Mutation analysis of BRCA1 and BRCA2 genes in Iranian high risk breast cancer families
Background: Telomerase is a ribonucleoprotein enzyme that synthesises telomeres after cell
division and maintains chromosomal stability leading to cellular immortalization. Telomerase has
been associated with negative prognostic indicators in some studies. The present study aims to
detect any association between telomerase sub-units: hTERT and hTR and the prognostic
indicators including tumour's size and grade, nodal status and patient's age.
Methods: Tumour samples from 46 patients with primary invasive breast cancer and 3 patients
with benign tumours were collected. RT-PCR analysis was used for the detection of hTR, hTERT,
and PGM1 (as a housekeeping) genes expression.
Results: The expression of hTR and hTERT was found in 31(67.4%) and 38 (82.6%) samples
respectively. We observed a significant association between hTR gene expression and younger age
at diagnosis (p = 0.019) when comparing patients ≤ 40 years with those who are older than 40
years. None of the benign tumours expressed hTR gene. However, the expression of hTERT gene
was revealed in 2 samples.
No significant association between hTR and hTERT expression and tumour's grade, stage and nodal
status was seen.
Conclusion: The expression of hTR and hTERT seems to be independent of tumour's stage. hTR
expression probably plays a greater role in mammary tumourogenesis in younger women (≤ 40
years) and this may have therapeutic implications in the context of hTR targeting strategies
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