2,453 research outputs found
EFFECT OF MN CONTENT ON THE STRUCTURAL & OPTICAL PROPERTIES OF CO PRECIPITATED MN -ZnO NANO PARTICLES.
Metal oxide nanoparticle applications in energy storage devicewhich receive attention for the future energy requirement. These transition metaloxides, when falling in the nanosized that process more applications in the field suchas data storage, spintronics, biomedicine and telecommunication. Mn-ZnOnanoparticles were synthesized by Co Precipitation method. The oxalic acid solutiondrop wise added to the metal salt solution with continuous stirring to get light pinkprecipitate dried at 1000C . The synthesized powder was calcined at varioustemperatures. Such as 2000C, 3000C, 4000C to obtain block color Mn-ZnOnanoparticles. These particles thus prepared were characterized by FTIR, UV-Visible.The optical band gap of Mn-ZnO nanoparticle was estimated by UV-VisibleSpectroscopy .The direct band gap values were found to be 2.1eV, 2.5eV, and 3eV
A note on dual giant gravitons in
We study some of the properties of dual giant gravitons - D2-branes wrapped
on an - in type IIA string theory on . In particular we confirm that the spectrum of small
fluctuations about the giant is both real and independent of the size of the
graviton. We also extend previously developed techniques for attaching open
strings to giants to this D2-brane giant and focus on two particular limits of
the resulting string sigma model: In the pp-wave limit we quantize the string
and compute the spectrum of bosonic excitations while in the semiclassical
limit, we read off the fast string Polyakov action and comment on the
comparison to the Landau-Lifshitz action for the dual open spin chain.Comment: v3 significantly changed: added coupling to RR 1-form and turned on
worldvolume gauge field, computed gauge field fluctuation, added comments on
closure of the sl(2) sector and re-written to improve clarity. This version
published in JHE
Emergence of the fuzzy horizon through gravitational collapse
For a large enough Schwarzschild black hole, the horizon is a region of space
where gravitational forces are weak; yet it is also a region leading to
numerous puzzles connected to stringy physics. In this work, we analyze the
process of gravitational collapse and black hole formation in the context of
light-cone M theory. We find that, as a shell of matter contracts and is about
to reveal a black hole horizon, it undergoes a thermodynamic phase transition.
This involves the binding of D0 branes into D2's, and the new phase leads to
large membranes of the size of the horizon. These in turn can sustain their
large size through back-reaction and the dielectric Myers effect - realizing
the fuzzball proposal of Mathur and the Matrix black hole of M(atrix) theory.
The physics responsible for this phenomenon lies in strongly coupled 2+1
dimensional non-commutative dynamics. The phenomenon has a universal character
and appears generic.Comment: 24 pages, 4 figures; v2: minor clarifications, citations adde
Towards a Realization of the Condensed-Matter/Gravity Correspondence in String Theory via Consistent Abelian Truncation
We present an embedding of the 3-dimensional relativistic Landau-Ginzburg
model for condensed matter systems in an ,
Chern-Simons-matter theory (the ABJM model) by consistently truncating the
latter to an abelian effective field theory encoding the collective dynamics of
of the modes. In fact, depending on the VEV on
one of the ABJM scalars, a mass deformation parameter and the
Chern-Simons level number , our abelianization prescription allows us to
interpolate between the abelian Higgs model with its usual multi-vortex
solutions and a theory. We sketch a simple condensed matter model that
reproduces all the salient features of the abelianization. In this context, the
abelianization can be interpreted as giving a dimensional reduction from four
dimensions.Comment: 4 pages, revtex; reference added, typo corrected; added clarifying
paragraphs at end of introduction and on pages 3-4. Version accepted to PR
USE OF LIBRARY RESOURCES AND SERVICES AMONG PG STUDENTS AND RESEARCH SCHOLARS OF ALAGAPPA UNIVERSITY : A STUDY
The main purpose of the study and use of Library resources and Services of Information. The researcher prepared questionnaire with 13 questions to be answered by the respondents about the level and Use of Library Resources and services of the 100 Questionnaries distributed 90 taken for the analysis 65.55% the respondents belong to Female category, 42.22% of the respondents belong to the age group of 26 – 30, 40.00% of respondents belong to the category of Ph.D scholars, 43.33% of respondents belong to the rural area, 42.22% of respondents belong to the Access at Library, 33.33% of respondents belong to the Daily time spent, 22.22% of respondents belong to the purpose of Consult materials for research, 38.88% of respondents belong to the Theses/Dissertations, 23.33% of Respondents belong to the reference services, 32.22% of Respondents belong to theUtilization of Index and abstract, 36.66% of Respondents belong to the Insufficient Internet Access points, 41.11% of Respondents belong to theHighly satisfied
INFORMATION NEEDS AND USE OF LIBRARY RESOURCES BY DIFFERENTLY ABLED SCHOOL STUDENTS, SIVAGANGAI DISTRICT: A CASE STUDY
The Study Analysed Information needs and use of library resources by Differently abled school students.54.08% of the Respondents belong to the female students, 32.65% of respondents were in the age group of below12, (35.71%) respondents were in the group of students 1st-5th, (73.47%) respondents were physically challenged with of use electronic resources, (29.59%) respondents accessed electronic resources Monthly, 50(51.02%) respondents were satisfied with the relevance of the electronic resources, (87.75%) respondents were read of the regularly Newspaper in electronic resources available from the library,73.46% of respondents were Easy to access,92 (93.87%) respondents were visited in other library of the electronic resources available from the library,53(54.08%) respondents used electronic resources to prepare for Education,89 (90.81%) respondents were using internet of the electronic resources available from the library,67(68.37%) respondents used electronic resources to education in library,87 (88.77%) respondents were aware of the electronic resources available from the library,that 65(66.33%) respondents used electronic resources to prepare Textbook,the majority 72 (73.47%) respondents were physically challenged with of use electronic resources,48 (48.98%) respondents need for information in electronic resources to employment information need,journal and books were the most used information resources by the respondents (38, 38.78%)The survey research design was used for the study. The total population includes 132 registered users of the library made up of students from selected Government Schools and community users.A total number of 132 questionnaires were distributed among the respondents. The investigator could collect questionnaires from only 98 out of 132 respondents among whom the questionnaires were distributed
Improved Performance of Four Switch Three Phase with SEPIC-Based Inverter
The proposed novel four-switch three-phase (FSTP) inverter is to design to reduce the rate, difficulty, mass, and switching losses of the DC-AC conversion system. Here the output line voltage cannot exceed half the input voltage in the out-dated FSTP inverter and it operates at half the DC input voltage. Single-Ended Primary-Inductance Converter (SEPIC) is a novel design for the FSTP inverter proposed in this paper. In this proposed topology the necessity of output filters is not necessary for the pure sinusoidal output voltage. Related to out-dated FSTP inverter, the proposed FSTP SEPIC inverter raises the voltage utilization aspect of the input DC supply, where the suggested topology delivers the higher output line voltage which can be extended up to the full value of the DC input voltage. In the proposed topology a control used called the integral sliding-mode (ISM) control and this control is used to enhance its dynamics and to ensure strength of the system during different operating conditions. Simulation model and results are used to authorise the proposed concept and simulations results show the effectiveness of the proposed inverter
Quantifying selection in immune receptor repertoires
The efficient recognition of pathogens by the adaptive immune system relies
on the diversity of receptors displayed at the surface of immune cells. T-cell
receptor diversity results from an initial random DNA editing process, called
VDJ recombination, followed by functional selection of cells according to the
interaction of their surface receptors with self and foreign antigenic
peptides. To quantify the effect of selection on the highly variable elements
of the receptor, we apply a probabilistic maximum likelihood approach to the
analysis of high-throughput sequence data from the -chain of human
T-cell receptors. We quantify selection factors for V and J gene choice, and
for the length and amino-acid composition of the variable region. Our approach
is necessary to disentangle the effects of selection from biases inherent in
the recombination process. Inferred selection factors differ little between
donors, or between naive and memory repertoires. The number of sequences shared
between donors is well-predicted by the model, indicating a purely stochastic
origin of such "public" sequences. We find a significant correlation between
biases induced by VDJ recombination and our inferred selection factors,
together with a reduction of diversity during selection. Both effects suggest
that natural selection acting on the recombination process has anticipated the
selection pressures experienced during somatic evolution
Report of Acoustic Test on PSLV IS.1/2L Structure
The results of acoustic conducted on PSLV IS.1/2L at Acoustic Test Facility are briefly given. It contains test set up,
Instrumentation details and tables of spectral response
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