8,790 research outputs found
Microscale application of column theory for high resolution force and displacement sensing
We present the design, fabrication and experimental validation of a novel
device that exploits the amplification of displacement and attenuation of
structural stiffness in the post-buckling deformation of slender columns to
obtain pico-Newton force and nanometer displacement resolution even under an
optical microscope. The extremely small size, purely mechanical sensing scheme
and vacuum compatibility of the instrument makes it compatible with existing
visualization tools of nanotechnology. The instrument has a wide variety of
potential applications ranging from electro-mechanical characterization of one
dimensional solids to single biological cells
Salicylic Acid, Sulphosalicylic Acid & Salicylamide as Indicators for Direct Titration of Fe3+ with Diethylene Triaminepentaacetic Acid
1119-112
A -ray determination of the Universe's star-formation history
The light emitted by all galaxies over the history of the Universe produces
the extragalactic background light (EBL) at ultraviolet, optical, and infrared
wavelengths. The EBL is a source of opacity for rays via photon-photon
interactions, leaving an imprint in the spectra of distant -ray
sources. We measure this attenuation using {739} active galaxies and one
gamma-ray burst detected by the {\it Fermi} Large Area Telescope. This allows
us to reconstruct the evolution of the EBL and determine the star-formation
history of the Universe over 90\% of cosmic time. Our star-formation history is
consistent with independent measurements from galaxy surveys, peaking at
redshift . Upper limits of the EBL at the epoch of re-ionization
suggest a turnover in the abundance of faint galaxies at .Comment: Published on Science. This is the authors' version of the manuscrip
New limits on top squark NLSP from ATLAS 4.7 data
Using the ATLAS 4.7 data on new physics search in the jets + \met
channel, we obtain new limits on the lighter top squark ()
considering all its decay modes assuming that it is the next to lightest
supersymmetric particle (NLSP). If the decay \lstop \ra c \lspone dominates
and the production of dark matter relic density is due to NLSP - LSP
co-annihilation then the lower limit on \mlstop is 240 GeV. The limit
changes to 200 GeV if the decay \lstop \ra b W \lspone dominates. Combining
these results it follows that \lstop NLSP induced baryogenesis is now
constrained more tightly.Comment: 9 pages, 2 figures, published in MPL
Diffusion Coefficients Of D-glucose In Aqueous Carboxymethylcellulose And Carboxypolymethylene Solutions
A micro interferometric method was used to determine pseudo-binary, molecular diffusion coefficients for diffusion of D-glucose in aqueous carboxymethylcellulose (CMC) and aqueous carboxypolymethylene (Carbopol) solutions. An initial solute concentration of about 9 wt. % D-glucose in the aqueous polymer solutions was used. The polymer concentrations for the CMC solutions ranged from 1.2 to 2.2 wt. % and for the Carbopol solutions from 0.18 to 0.28 wt. %. Diffusion coefficients were determined as a function of reduced solute concentration, both with and without the effect of solution volume change during diffusion being considered. © 1969, American Chemical Society. All rights reserved
Synthesis and Elastic Characterization of Zinc Oxide Nanowires
Zinc oxide nanowires, nanobelts, and nanoneedles were synthesized using the vapor-liquid-solid technique. Young's modulus of the nanowires was measured by performing cantilever bending experiments on individual nanowires in situ inside a scanning electron microscope. The nanowires tested had diameters in the range of 200–750 nm. The average Young's modulus, measured to be 40 GPa, is about 30% of that reported at the bulk scale. The experimental results are discussed in light of the pronounced electromechanical coupling due to the piezoelectric nature of the material
EVOLUTION OF NANOTECH ASSISTED PCR DIAGNOSIS OF MYCOBACTERIUM TUBERCULOSIS AND ITS ASSESSMENT WITH CONVENTIONAL METHODS
Objective: This study was focused on assessment and performance of conventional and nanotech assisted methods for detection of Mycobacterium tuberculosis. Tuberculosis (TB) still leftovers one of the top ten causes of death worldwide, thus this study has undertaken the use of MNP for early detection of TB.Methods: A cross-sectional studies were conducted on clinical and radiological suspected TB patients in the department of microbiology at D. Y. Patil hospital Kolhapur. All samples received in the month of August 2016 to January 2017. Total One hundred twenty-sputum samples were processed for diagnosis of TB by ZN stain, culture on L. J. Medium and real-timePCR tests.Results: In our present study, 60.83% (73) patient male and 39.17 % (47) were female patient, showing a borderline male prevalence found in our study. Eighteen percent patients were found to be in the age group (21-30 y) are mostly affected for pulmonary tuberculosis. A significant difference was seen in the percentage of differentDNA extraction methods, the fig. being conventional chloroform-phenol 66.66%, the commercial kit 80%, magnetic bead 86.66% and MNPs method 99.66% found to be significant (P<0.0001**).Conclusion: In the present study the MNP-DNA extraction techniques with NALC followed by IS6110 target amplification were found superior for diagnosis of TB. The MNP assisted extraction method showed better results in terms of quantification and sensitivity of TB PCR diagnosis, evolving nanotech assisted innovative method
Regulatory roles of the cadherin superfamily
Charged with the task of providing a molecular link between adjacent cells, the cadherin superfamily consists of over 100 members and populates the genomes of organisms ranging from vertebrates to cniderians. This breadth hints at what decades of research has confirmed: that cadherin-based adhesion and signaling events regulate diverse cellular processes including cell-sorting, differentiation, cell survival, proliferation, cell polarity, and cytoskeletal organization
Surface roughness effect on ultracold neutron interaction with a wall and implications for computer simulations
We review the diffuse scattering and the loss coefficient in ultracold
neutron reflection from slightly rough surfaces, report a surprising reduction
in loss coefficient due to roughness, and discuss the possibility of transition
from quantum treatment to ray optics. The results are used in a computer
simulation of neutron storage in a recent neutron lifetime experiment that
re-ported a large discrepancy of neutron lifetime with the current particle
data value. Our partial re-analysis suggests the possibility of systematic
effects that were not included in this publication.Comment: 39 pages, 9 figures; additional calculations include
The Star Formation Histories of z ~ 2 Dust-obscured Galaxies and Submillimeter-selected Galaxies
The Spitzer Space Telescope has identified a population of ultraluminous infrared galaxies (ULIRGs) at z ~ 2 that may play an important role in the evolution of massive galaxies. We measure the stellar masses (M_*) of two populations of Spitzer-selected ULIRGs that have extremely red R – [24] colors (dust-obscured galaxies, or DOGs) and compare our results with submillimeter-selected galaxies (SMGs). One set of 39 DOGs has a local maximum in their mid-infrared (mid-IR) spectral energy distribution (SED) at rest frame 1.6 μm associated with stellar emission ("bump DOGs"), while the other set of 51 DOGs have power-law mid-IR SEDs that are typical of obscured active galactic nuclei ("power-law DOGs"). We measure M_* by applying Charlot & Bruzual stellar population synthesis models to broadband photometry in the rest-frame ultraviolet, optical, and near-infrared of each of these populations. Assuming a simple stellar population and a Chabrier initial mass function, we find that power-law DOGs and bump DOGs are on average a factor of 2 and 1.5 more massive than SMGs, respectively (median and inter-quartile M_* values for SMGs, bump DOGs, and power-law DOGs are log(M_*/M_☉) = 10.42^(+0.42)_(–0.36), 10.62^(+0.36)_(–0.32), and 10.71^(+0.40)_(–0.34), respectively). More realistic star formation histories drawn from two competing theories for the nature of ULIRGs at z ~ 2 (major merger versus smooth accretion) can increase these mass estimates by up to 0.5 dex. A comparison of our stellar masses with the instantaneous star formation rate (SFR) in these z ~ 2 ULIRGs provides a preliminary indication supporting high SFRs for a given M_*, a situation that arises more naturally in major mergers than in smooth accretion-powered systems
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