Monitoring Changes in Vegetation Cover of Bhitarkanika Marine National Park Region, Odisha, India Using Vegetation Indices of Multidate Satellite Data

1916-1924The coast of Odisha extends from Balasore in the north to Ganjam in the south spreading 480 km. It exhibits a depositional terrain formed by the action of fluvio-marine, lacustrine, estuarine and aeolian agents. The river system coupled with marine action help in generating diversified physiographic and dynamic coastal features. Over the period, the coastal tract also witnesses the vagary of nature. Vast alluvial plain, meandering pattern of rivers, low lying swamps and swamp forests, sand dunes, beach ridges, beaches and swales are typical landforms associated with the coastal tract. The Bhitarkanika Marine National Park region, the study area is situated on the northern part of the coast which mostly exhibit swampy habitat due to large fine clastic deposits by riverine action. Mangroves on the swampy region occupy around 18,348 ha and regarded as the second largest mangrove formation in the subcontinent. Besides, the coastal tract also exhibits a congenial place for mass nesting of sea turtles coming from Pacific Ocean. The study area is now under stress due to various natural as well as anthropogenic pressure. The degradation of mangroves is mainly due to human encroachment and reclamation of land for aquaculture practices. It is observed that the occurrence of vegetation cover decreases continuously from 1973 to 2017. Dense vegetation cover is recorded as 35.23 % ( 1973) which decreased to 22.43 % ( 2017). On the southern end of the study area lies an all-weather port named Paradeep and on the northern side one emerging new port called Dhamra port. Their activities and impact as well as blooming aquaculture practices have bearing on the ecosystem of the mangroves. The assessment of vegetation vigor of the region portrays the condition of the environment shaped after years of degradation activities due to natural as well as anthropogenic activities induced from 595 villages having 50,6930 population. The objective of the study is to analyze the changes of vegetation vigor using NDVI from multi date satellite data and record the changes for better monitoring of the area. It may be inferred that the existing conservation measures and protection plans are inadequate to hold the coastal natural resources intact. The community participation and public awareness are not sufficient to abate the brittle coastal environment. Public participation, education programme, awareness initiatives are the foundation of success of any sustainable development in the sensitive coastal region

Some FRW Models of Accelerating Universe with Dark Energy

The paper deals with a spatially homogeneous and isotropic FRW space-time filled with perfect fluid and dark energy components. The two sources are assumed to interact minimally, and therefore their energy momentum tensors are conserved separately. A special law of variation for the Hubble parameter proposed by Berman (1983) has been utilized to solve the field equations. The Berman's law yields two explicit forms of the scale factor governing the FRW space-time and constant values of deceleration parameter. The role of dark energy with variable equation of state parameter has been studied in detail in the evolution of FRW universe. It has been found that dark energy dominates the universe at the present epoch, which is consistent with the observations. The physical behavior of the universe is discussed in detail.Comment: 10 pages, 5 figure

First report of four deep-sea chondrichthyans (Elasmobranchii and Holocephali) from Andaman waters, India with an updated checklist from the region

This paper confirms the new distributional records of four rare deep-water chondrichthyans viz. sharpnose sevengill shark, Heptranchias perlo (Bonnaterre, 1788); bluntnose sixgill shark, Hexanchus griseus (Bonnaterre, 1788); bramble shark, Echinorhinus brucus (Bonnaterre, 1788); and sicklefin chimaera, Neoharriotta pinnata (Schnakenbeck, 1931) from the Andaman waters in the Indian EEZ. The above-mentioned four fish species have not been reported earlier from this region. More exploratory surveys in the region are essential to understand the diversity and distribution pattern which is essential for critical management actions. An updated checklist of chondrichthyans known from Andaman and Nicobar waters of India is also presented

Transport across nanogaps using semiclassically consistent boundary conditions

Charge particle transport across nanogaps is studied theoretically within the Schrodinger-Poisson mean field framework and the existence of limiting current investigated. It is shown that the choice of a first order WKB wavefunction as the transmitted wave leads to self consistent boundary conditions and gives results that are significantly different in the non-classical regime from those obtained using a plane transmitted wave. At zero injection energies, the quantum limiting current density, J_c, is found to obey the local scaling law J_c ~ (V_g)^alpha/(D)^{5-2alpha} with the gap separation D and voltage V_g. The exponent alpha > 1.1 with alpha --> 3/2 in the classical regime of small de Broglie wavelengths. These results are consistent with recent experiments using nanogaps most of which are found to be in a parameter regime where classical space charge limited scaling holds away from the emission dominated regime.Comment: 4 pages, 4 ps figure

Experimental evaluation of matrix converter for wind energy conversion system under various abnormal conditions

This paper presents the experimental evaluation of reversed indirect matrix converter (MC) interfaced wind energy conversion system (WECS), where space vector pulse width modulation together with adaptive fuzzy logic control is effectively used to enhance the performance of system under various abnormal conditions like abrupt change in wind speed, disconnection from grid, misfire in the converter, sudden out of one phase, change in load etc. The proposed adaptive control system is realized using dSPACE DS1104 board. Selective experimental results are presented using a laboratory 1.2 kW prototype of WECS to demonstrate the resulting improvements of the developed system under abnormal conditions.http://www.ijrer.org/ijrer/index.php/ijreram201

Resonances in nitrobenzene probed by the electron attachment to neutral and by the photodetachment from anion

We probe resonances (transient anions) in nitrobenzene with the focus on the electron emission from these. Experimentally, we populate resonances in two ways: either by the impact of free electrons on the neutral molecule or by the photoexcitation of the bound molecular anion. These two excitation means lead to transient anions in different initial geometries. In both cases, the anions decay by electron emission and we record the electron spectra. Several types of emission are recognized, differing by the way in which the resulting molecule is vibrationally excited. In the excitation of specific vibrational modes, distinctly different modes are visible in electron collision and photodetachment experiments. The unspecific vibrational excitation, which leads to the emission of thermal electrons following the internal vibrational redistribution, shows similar features in both experiments. A model for the thermal emission based on a detailed balance principle agrees with the experimental findings very well. Finally, a similar behavior in the two experiments is also observed for a third type of electron emission, the vibrational autodetachment, which yields electrons with constant final energies over a broad range of excitation energies. The entrance channels for the vibrational autodetachment are examined in detail, and they point to a new mechanism involving a reverse valence to non-valence internal conversion

Intersecting D-branes in Type IIB Plane Wave Background

We study intersecting D-branes in a type IIB plane wave background using Green-Schwarz worldsheet formulation. We consider all possible $D_\pm$-branes intersecting at angles in the plane wave background and identify their residual supersymmetries. We find, in particular, that $D_\mp - D_\pm$ brane intersections preserve no supersymmetry. We also present the explicit worldsheet expressions of conserved supercharges and their supersymmetry algebras.Comment: 32 pages, 2 tables; Corrected typos, to appear in Phys. Rev.

Dissipative Future Universe without Big Rip

The present study deals with dissipative future universe without big rip in context of Eckart formalism. The generalized chaplygin gas, characterized by equation of state $p=-\frac{A}{\rho^\frac{1}{\alpha}}$, has been considered as a model for dark energy due to its dark-energy-like evolution at late time. It is demonstrated that, if the cosmic dark energy behaves like a fluid with equation of state $p=\omega\rho$; $\omega < -1$, as well as chaplygin gas simultaneously then the big rip problem does not arises and the scale factor is found to be regular for all time.Comment: 6 pages, 2 figures, To appear in Int. J. Theor. Phy

Taro in west Africa: status, challenges, and opportunities

Open Access JournalTaro is an ancient nutritional and medicinal crop woven into the fabric of the socio-economic life of those living in the tropics and sub-tropics. However, West Africa (WA), which has been a major producer of the crop for several decades, is experiencing a significant decline in production as a result of taro leaf blight (TLB), a disease caused by Phytophthora colocasiae Raciborski. A lack of research on taro in WA means that available innovative technologies have not been fully utilized to provide solutions to inherent challenges and enhance the status of the crop. Improvement through plant breeding remains the most economically and environmentally sustainable means of increasing the productivity of taro in WA. With this review, we provide insights into the importance of the taro crop in WA, evaluate taro research to date, and suggest how to address research gaps in order to promote taro sustainability in the region

Cosmological models with linearly varying deceleration parameter

We propose a new law for the deceleration parameter that varies linearly with time and covers Berman's law where it is constant. Our law not only allows one to generalize many exact solutions that were obtained assuming constant deceleration parameter, but also gives a better fit with data (from SNIa, BAO and CMB), particularly concerning the late time behavior of the universe. According to our law only the spatially closed and flat universes are allowed; in both cases the cosmological fluid we obtain exhibits quintom like behavior and the universe ends with a big-rip. This is a result consistent with recent cosmological observations.Comment: 12 pages, 7 figures; some typo corrections; to appear in International Journal of Theoretical Physic