16,123 research outputs found
Good girls and boys: findings from a cross-sectional survey on adolescent rights, relationships, and sexuality in an urban informal settlement in India
Around 20% of India’s population are adolescents aged 10–19 years. Our objective was to strengthen program interventions on gender equity, health, and participation by gauging adolescents’ levels of understanding and opinions. In a cross-sectional survey, we interviewed 2005 adolescents on their opinions on rights, friendship and sex, sexual refusal and coercion, and communication with family, using a two-stage probability proportional to size sample. Opinions on gender allocations were generally equitable, although females supported clothing proscriptions. Premarital sex, multiple partners, masturbation and non-heterosexual partnerships were frowned upon. Few respondents said that they felt pressure to be sexually active, 79% said that sexual coercion was a form of violence, but 14% of older adolescents said that it would be unreasonable to refuse sex. Our interviews described young people negotiating the terrain between perceived normative expectations and contemporary aspirations, showing limited manoeuvring within assumed gender roles in which family control was prominent
Facile synthesis of mesoporous N doped zirconium titanium mixed oxide nanomaterial with enhanced photocatalytic activity under visible light
The present paper deals with a hydrazine mediated synthesis of high surface area and thermally stable
N-doped zirconium titanium mixed oxide with enhanced photocatalytic activity towards reduction of
selenium (VI) to metallic Se0 under visible light. Materials were synthesized at pH ¼ 2 by varying the
hydrazine concentration and characterized by XRD, TEM, BET method, XPS, Raman spectroscopy
and UV-vis solid state spectra. Presence of low amount of zirconium oxide (10 wt%) helps in phase
stabilization and maintains the porous structure even at higher calcinations temperature in comparison
to that of pure titania. XPS spectrum justifies the presence of nitrogen and Ti3+ in the material due to
the decomposition reaction of hydrazine. Hydrazine controls the nitrogen content, surface area and the
formation of oxygen vacancy in the material. Investigation of metal oxide to hydrazine ratio on the
overall surface properties and photocatalytic activity indicates that the 1 : 6 ratio is the optimum
composition for the best result. Surface area and pore volume increases to 298 m2/g and 0.323 cm3/g.
The obtained material (TiZr-6N-400) is found to reduce selenium (VI) to selenium (0) under visible light
within only 45 min of reaction. Increased photocatalytic activity under visible light is mostly due to the
synergistic effect of substantial nitrogen doping, high surface area and presence of oxygen vacancy
Fluctuation Induced Non-Fermi Liquid Behavior near a Quantum Phase Transition in Itinerant Electron Systems
The signature for a non-Fermi liquid behavior near a quantum phase transition
has been observed in thermal and transport properties of many metallic systems
at low temperatures. In the present work we consider specific examples of
itinerant ferromagnet as well as antiferromagnet in the limit of vanishing
transition temperature. The temperature variation of spin susceptibility,
electrical resistivity, specific heat, and NMR relaxation rates at low
temperatures is calculated in the limit of infinite exchange enhancement within
the frame work of a self consistent spin fluctuation theory. The resulting
non-Fermi liquid behavior is due to the presence of the low lying critically
damped spin fluctuations in these systems. The theory presented here gives the
leading low temperature behavior, as it turns out that the fluctuation
correlation term is always smaller than the mean fluctuation field term in
three as well as in two space dimensions. A comparison with illustrative
experimental results of these properties in some typical systems has been done.
Finally we make some remarks on the effect of disorder in these systems.Comment: File RevTex, 7 Figures available on request, Abstract and text
modified, To appear in Phys. Rev.
Truthful Multi-unit Procurements with Budgets
We study procurement games where each seller supplies multiple units of his
item, with a cost per unit known only to him. The buyer can purchase any number
of units from each seller, values different combinations of the items
differently, and has a budget for his total payment.
For a special class of procurement games, the {\em bounded knapsack} problem,
we show that no universally truthful budget-feasible mechanism can approximate
the optimal value of the buyer within , where is the total number of
units of all items available. We then construct a polynomial-time mechanism
that gives a -approximation for procurement games with {\em concave
additive valuations}, which include bounded knapsack as a special case. Our
mechanism is thus optimal up to a constant factor. Moreover, for the bounded
knapsack problem, given the well-known FPTAS, our results imply there is a
provable gap between the optimization domain and the mechanism design domain.
Finally, for procurement games with {\em sub-additive valuations}, we
construct a universally truthful budget-feasible mechanism that gives an
-approximation in polynomial time with a
demand oracle.Comment: To appear at WINE 201
Constraints on nuclear matter parameters of an Effective Chiral Model
Within an effective non-linear chiral model, we evaluate nuclear matter
parameters exploiting the uncertainties in the nuclear saturation properties.
The model is sternly constrained with minimal free parameters, which display
the interlink between nuclear incompressibility (), the nucleon effective
mass (), the pion decay constant () and the meson
mass (). The best fit among the various parameter set is then
extracted and employed to study the resulting Equation of state (EOS). Further,
we also discuss the consequences of imposing constraints on nuclear EOS from
Heavy-Ion collision and other phenomenological model predictions.Comment: 10 pages, 8 figure
Interplanetary and Geomagnetic Consequences of Interacting CMEs of 13-14 June 2012
We report on the kinematics of two interacting CMEs observed on 13 and 14
June 2012. Both CMEs originated from the same active region NOAA 11504. After
their launches which were separated by several hours, they were observed to
interact at a distance of 100 Rs from the Sun. The interaction led to a
moderate geomagnetic storm at the Earth with Dst index of approximately, -86
nT. The kinematics of the two CMEs is estimated using data from the Sun Earth
Connection Coronal and Heliospheric Investigation (SECCHI) onboard the Solar
Terrestrial Relations Observatory (STEREO). Assuming a head-on collision
scenario, we find that the collision is inelastic in nature. Further, the
signatures of their interaction are examined using the in situ observations
obtained by Wind and the Advance Composition Explorer (ACE) spacecraft. It is
also found that this interaction event led to the strongest sudden storm
commencement (SSC) (approximately 150 nT) of the present Solar Cycle 24. The
SSC was of long duration, approximately 20 hours. The role of interacting CMEs
in enhancing the geoeffectiveness is examined.Comment: 17 pages, 5 figures, Accepted in Solar Physics Journa
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