3,174 research outputs found
A Method for Measuring the Magnetic Dipole Transition Moment in {Ba}
We propose a method for measuring the magnetic dipole (M1) transition moment
of the transition in single trapped Ba by
exploiting different symmetries in the electric quadrupole (E2) and M1
couplings between the states. The technique is adapted from a previously
proposed method for measuring atomic parity nonconservation in a single trapped
ion [Norval Fortson, Phys. Rev. Lett. \textbf{70}, 17 (1993)]. Knowledge of M1
is crucial for any parity nonconservation measurement in Ba, as laser
coupling through M1 can mimic the parity-violating signal. The magnetic moment
for the transition has been calculated by atomic theory and found to be
dominated by electron-electron correlation effects [B.K. Sahoo et. al., Phys.
Rev. A \textbf{74}, 6 (2006)]. To date the value has not been verified
experimentally. This proposed measurement is therefore an essential step toward
a parity nonconservation experiment in the ion that will also test current
many-body theory. The technique can be adapted for similar parity
nonconservation experiments using other atomic ions, where the magnetic dipole
moment could present similar complications
Socio-economic Impact Assessment of Livelihood Security in Agriculture, Animal Husbandry and Aquaculture on the Tsunami-hit Lands of Andaman
Indian subcontinent is highly vulnerable to major natural disasters such as earthquakes, cyclones, floods, droughts, landslides and bushfires. Tsunami, which is a recent addition to this list, had occurred in the early morning of 26th December 2004, after a massive earthquake of 9.2 magnitude on the Richter scale in Andaman & Nicobar islands, resulting in the submergence of large area of farmland, and subsequent drying up of water bodies. It caused moisture stress for the standing crops, livestock and fisheries and affected the livelihood of the people to a large extent. In this context, the present study has been carried out to make the socio-economic impact assessment of livelihood security in agriculture, animal husbandry and aquaculture on the tsunami-hit lands of Andaman. Data have been collected from 150 sample respondents and the survey has been conducted for two periods, pre-tsunami and post-tsunami. The results have indicated that tsunami has ravaged the households, standing crops, farm inputs such as seed, feed and implements, livestock and poultry population, their sheds, fish ponds, etc., thereby affecting the basic livelihood security of the people in Andaman. The rehabilitation measures taken by the government and NGOs have improved their livelihoods by reviving agriculture considerably in the subsequent years and by creating employment opportunities in various farm and non-farm activities. The paper has suggested creating profitable livelihood security to vulnerable sections of the society in the existing socio-economic penury with holistic intervention of the community, government and NGOs.Agricultural and Food Policy,
Synthesis and characterization of N-methylenephenyl phosphonic chitosan
Chitosan is a natural based polymer obtained by alkaline deacetylation of chitin, exhibiting excellent properties such as non‐toxicity, biocompatibility and biodegradability. N‐Methylenephenyl phosphonic chitosan (NMPPC) is synthesized from chitosan by reacting with phenyl phosphonic acid using formaldehyde. The NMPPC was characterized by FTIR, 31P‐NMR, X‐ray diffraction, scanning electron microscopy, thermogravimeteric analysis and solubility studies. A significant decrease of molecular weight was observed in the NMPPC. The TGA studies suggested that NMPPC has less thermal stability than chitosan. The X‐ray diffraction analysis showed that NMPPC was amorphous in nature. The solubility property of the polymer was improved after the incorporation of a phenyl phosphonic grou
Phosphorous containing chitosan beads for controlled oral drug delivery
Phosphorous containing chitosan (PCTS) was synthesized by a
graft copolymerization technique in order to be used as controlled drug delivery
devices. To test this potential, PCTS beads were prepared by using
tripolyphosphate, at pH 4.0 and characterized by scanning electron
microscopy. The in vitro drug release behavior in various pH solutions was
studied using indomethacin (IM) as a model drug at two different concentrations
(0.3 and 0.6% w/w). The release percent of IM from PCTS beads was
found to be increased with the increasing of pH in the buffer solution. The
release rate of IM at pH 7.4 was higher than that at pH 1.4, due to the ionization
of phosphorous groups and the high solubility of IM in the alkaline
medium. These results indicated that PCTS beads have the potential to be
used as controlled drug delivery systems through oral administration by avoiding
the drug release in the highly acidic gastric fluid region of the stomach
Chemistry and applications of phosphorylated chitin and chitosan
Chitin and chitosan are natural based non-toxic,
biodegradable and biocompatible polymers and have been used in
biomedical areas in the form of sutures, wound healing materials and
artificial skin, and for the sustained release of drugs as well as in various
industrial applications. However, practical use of these polymers has
been mainly confined to the unmodified forms. Recently, there has been
a growing interest in chemical modification of chitin and chitosan to
improve their solubility and widen their applications. Among them,
phosphorylated chitin and chitosan have attracted considerable interest
because of their various advantages: anti-inflammatory property, ability
to form metal complexes, blood compatibility and formation of anionic
polyelectrolyte hydrogels. The purpose of this review is to take a closer
look of different synthetic methods of phosphorylated chitin and chitosan
and their potential applications in environmental, food, fuel cell, and
biomedical fields. Based on current research and existing products,
some new and futuristic approaches in this context area are discussed.R. Jayakumar acknowledges the Portuguese Foundation for Science and Technology for providing him a Post-Doc scholarship (SFRH/BPD/14670/2003). This work was partially supported by FCT Foundation for Science and Technology, through funds from the POCTI and/or FEDER program. This work was partially supported by the European Union funded STREP Project HIPPOCRATES (NMP3-CT-2003-505758)
Noise Suppression in Images by Median Filter
A new and efficient algorithm for high-density salt and pepper noise removal in images and videos is proposed. In the transmission of images over channels, images are corrupted by salt and pepper noise, due to faulty communications. Salt and Pepper noise is also referred to as Impulse noise. The objective of filtering is to remove the impulses so that the noise free image is fully recovered with minimum signal distortion. Noise removal can be achieved, by using a number of existing linear filtering techniques. We will deal with the images corrupted by salt-and-pepper noise in which the noisy pixels can take only the maximum or minimum values (i.e. 0 or 255 for 8-bit grayscale images)
Protein kinase E of Mycobacterium tuberculosis has a role in the nitric oxide stress response and apoptosis in a human macrophage model of infection
Mycobacterium tuberculosis, an intracellular pathogen, inhibits macrophage apoptosis to support survival and replication inside the host cell. We provide evidence that the functional serine/threonine kinase, PknE, is important for survival of M. tuberculosis that enhances macrophage viability by inhibiting apoptosis.Apromoter of PknE identified in this study was shown to respond to nitric oxide stress. Deletion of pknE in virulent M. tuberculosis, H37Rv, resulted in a strain that has increased resistance to nitric oxide donors and increased sensitivity to reducing agents. The deletion mutant created by specialized transduction induced enhanced apoptosis while inhibiting necrosis. The pknE mutant also modifies the innate immune response as shown by the marked decline in the pro-inflammatory cytokines in a macrophage model of infection. These findings suggest a novel mechanism,bywhichPknEsensesnitricoxidestress and prevents apoptosis by interfering with host signalling pathways
Integrated waveguides and deterministically positioned nitrogen vacancy centers in diamond created by femtosecond laser writing
Diamond's nitrogen vacancy (NV) center is an optically active defect with
long spin coherence times, showing great potential for both efficient nanoscale
magnetometry and quantum information processing schemes. Recently, both the
formation of buried 3D optical waveguides and high quality single NVs in
diamond were demonstrated using the versatile femtosecond laser-writing
technique. However, until now, combining these technologies has been an
outstanding challenge. In this work, we fabricate laser written photonic
waveguides in quantum grade diamond which are aligned to within micron
resolution to single laser-written NVs, enabling an integrated platform
providing deterministically positioned waveguide-coupled NVs. This fabrication
technology opens the way towards on-chip optical routing of single photons
between NVs and optically integrated spin-based sensing
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