On optimal designing of low frequency polychromatic fields for facile photo-dissociation of model diatomic molecules

The dissociation of a diatomic molecule in low frequency polychromatic fields of moderate intensities is studied. Genetic Algorithm is invoked to search out a set of four optimal non-resonant frequencies (ω 1 - ω 4), intensities (ε1-ε4) the and phase angles (δ1 - δ 4), for achieving a facile photo dissociation. Time-dependent Hellmann-Feynman theorem is used to gain insight into the frequency resolved energy absorption pattern. The 'quantum phase space' structures indicate occurrence of bond breaking dynamics akin to the classical one

Tunnelling time and tunnelling dynamics

The concept of 'tunnelling time' in the context of quantum particle tunnelling is reviewed. Various suggestions of linking the tunnelling dynamics with a characteristic time (real or complex) like the phase time, barrier interaction time (bounce time), presence time, etc. are analysed. A simple but fully quantal method of defining and estimating a real tunnelling time is examined in a variety of situations. The recently proposed idea of interpreting 'tunnelling time' as the cavity lifetime of a particle is also explored. We emphasize that proton or H-atom transfer reactions in double or triple wells offer systems in which the signature of the tunnelling time should be recognizable not just indirectly through the tunnelling splitting of spectral lines, but by following the relaxation dynamics of the subsystem that the proton or H atom leaves by tunnelling

Nonequilibrium tricriticality in one dimension

We show the existence of a nonequilibrium tricritical point induced by a repulsive interaction in one dimensional asymmetric exclusion process. The tricritical point is associated with the particle-hole symmetry breaking introduced by the repulsion. The phase diagram and the crossover in the neighbourhood of the tricritical point for the shock formation at one of the boundaries are determined.Comment: 6 pages; 4 figure

CSF Biomarkers for Alzheimer's Disease Diagnosis

Alzheimer's disease (AD) is the most common form of dementia that affects several million people worldwide. The major neuropathological hallmarks of AD are the presence of extracellular amyloid plaques that are composed of Aβ40 and Aβ42 and intracellular neurofibrillary tangles (NFT), which is composed of hyperphosphorylated protein Tau. While the amyloid plaques and NFT could define the disease progression involving neuronal loss and dysfunction, significant cognitive decline occurs before their appearance. Although significant advances in neuroimaging techniques provide the structure and physiology of brain of AD cases, the biomarker studies based on cerebrospinal fluid (CSF) and plasma represent the most direct and convenient means to study the disease progression. Biomarkers are useful in detecting the preclinical as well as symptomatic stages of AD. In this paper, we discuss the recent advancements of various biomarkers with particular emphasis on CSF biomarkers for monitoring the early development of AD before significant cognitive dysfunction

Deep Learning Based Thermal Image Processing Approach for Detection of Buried Objects and Mines

Thermal imaging based mine detection technique is widely adopted due it suitability of detecting buried metallic and also non-metallic land mines in battle fields. Accurate mine detection using thermal images depends on thermal contrast between the soil and mine and it is affected by various factors such as the depth of burial; soil properties and attributes, water content in the soil, mine properties; as well as the time of day of image acquisition. With temporal temperature variations of the soil, it is difficult to distinguish and discriminate between the buried object and the background in the thermal image using the conventionally followed binary thresholding approach in gray scale. This paper presents deep learning region convolution based neural network approach to identify the buried objects in thermal images. A region interest selection using a bound box is followed for identifying the buried object in the thermal image.  From the experimental results, it is found that there is temperature variation in the thermal images of the buried objects due to the change in heat carrying capacity of the surround soil. Proposed neural network method showed 90% accuracy in predicting the target locations of buried objects in the thermal images and it can be extended for land mine detection using thermal image processing approach

Identifying sources and controlling factors of arsenic release in saline groundwater aquifers

An integrated hydrogeochemical study was carried out to realize the occurrence of arsenic (As) in a saline aquifer. Saline groundwater was mostly concentrated in the uppermost aquifer, and non-saline water was in the lower aquifer in the study area. High As concentrations were found in both the uppermost and lower aquifers. No correlation among salinity, well depth and As concentration was observed. Various forms of Fe oxyhydroxides were identified in the magnetic fractions, which were concentrated by high gradient magnetic separation (HGMS) technique, revealing that the redox cycling of Fe occurred in the subsurface. High levels of Fe, HCO₃^-, DOC and NH₄⁺ concentrations accompanying alkaline pH in the As-rich groundwater were consistent with the mechanism triggered by the microbially mediated reductive dissolution of Fe oxyhydroxides. A proposed threshold value of 50μg L^-1 As concentration was used as an indicator for identification of active proceeding reductive dissolution of As-bearing Fe oxyhydroxides in the saline aquifer. Desorption behaviors of As were relevant to its valence in the sediments and the co-existence of anions. Experimental and numerical results showed that additions of Cl^- and SO₄^2-, which represent the main anions of saline water, had minor effect on leaching sedimentary As. Although bicarbonate addition resulted in less As desorption than that of phosphate on a molar basis, the contribution of bicarbonate to the total release of As was greater than phosphate due to the much higher concentration of bicarbonate in shallow groundwater and the associated microbial mediation. Collectively, the chemical effect of saline water on the As release to groundwater is mild in the coastal aquifer

Use of FFT in Protein Sequence Comparison under Their Binary Representations

Abstract The paper considers Voss type representation of amino acids and uses FFT on the represented binary sequences to get the spectrum in the frequency domain. Based on the analysis of this spectrum by using the method of inter coefficient difference (ICD), it compares protein sequences of ND5 and ND6 category. Results obtained agree with the standard ones. The purpose of the paper is to extend the ICD method of comparison of DNA sequences to comparison of protein sequences. The topic of discussion is to develop a novel method of comparing protein sequences. The main achievements of the work are that the method applied is completely new of its kind, so far as protein sequence comparison is concerned and moreover the results of comparison agree with the previous results obtained by other methods for the same category of protein sequences