Evaluation of time scale of meteorological,hydrological and agricultural drought indices

Natural Hazards - The present study was carried out to characterize drought in the Marathwada region of Maharashtra, which experiences recurring droughts, through meteorological, hydrological and...     

Probability distributions for carbon emissions and atmospheric response

Probability distributions for carbon burning, atmospheric CO₂, and global average temperature are produced by time series calibration of models of utility optimization and carbon and heat balance using log-linear production functions. Population growth is used to calibrate a logistically evolving index of development that influences production efficiency. Energy production efficiency also includes a coefficient that decreases linearly with decreasing carbon intensity of energy production. This carbon intensity is a piecewise linear function of fossil carbon depletion. That function is calibrated against historical data and extrapolated by sampling a set of hypotheses about the impact on the carbon intensity of energy production of depleting fluid fossil fuel resources and increasing cumulative carbon emissions. Atmospheric carbon balance is determined by a first order differential equation with carbon use rates and cumulative carbon use as drivers. Atmospheric CO₂ is a driver in a similar heat balance. Periodic corrections are included where required to make residuals between data and model results indistinguishable from independently and identically distributed normal distributions according to statistical tests on finite Fourier power spectrum amplitudes and nearest neighbor correlations. Asymptotic approach to a sustainable non-fossil energy production is followed for a global disaggregation into a tropical/developing and temperate/more-developed region. The increase in the uncertainty of global average temperature increases nearly quadratically with the increase in the temperature from the present through the next two centuries.     

Resampling routine on heterogeneous networked-based environment

In this paper, we have described a model to parallelize the resampling routine, which is used in the geometric correction of data provided by remote sensing satellites. Our model is a typical master-slave model consisting of N machines termed as hosts out of which one is designated as the master. The input image data resides on the master. Processing of the input image data is done in parallel on the N machines. Issues related to load-balancing and various error conditions that may occur during execution like one of the machines going down have been studied and are incorporated in the model. It also provides the flexibility to add or delete the hosts during the execution of the resampling routine. The serial version of this routine involves huge amount of computations and takes substantial amount of time even for an image of 473 MB. We have implemented our model with the help of PVM which is most often used in distributed computing environment. Our approach has been tested for geometric correction on LISS-III 4 band data of size 473 MB. It is found that if one uses 2, 3 or 4 hosts the overall execution time is reduced by 33%, 42% and 49%, respectively.     

A laboratory study of magnesium-tetrabenz-porphyrin; Lack of agreement with diffuse interstellar bands

We have measured the visible and infrared spectra and thermal behavior of the moleculebis-pyridal-magnesium-tetrabenz-porphyrin, the molecule proposed as the carrier of the diffuse interstellar bands. Of the six band coincidences reported by F. M. Johnson, only one, 4430 Å, occurs in our experiments. This coincidence requires a special environment, not likely in interstellar space. The infrared spectrum does not support Johnson's vibrational scheme. Our spectroscopic and thermal measurements contradict the hypothesis that this molecule causes the diffuse bands.     

Inhibition of fish nodavirus by gymnemagenol extracted from Gymnema sylvestre

Viral nervous necrosis(VNN)has emerged to become a major problem in the culture of larval and juvenile marine fish worldwide.Bioactive phytochemicals isolated from commonly available medicinal plants are often screened for their efficacy in controlling fish viral diseases.Occurrence of newer viral strains and resistance to existing antiviral drugs are problems currently as-sociated with treatment of VNN,which necessitates looking for alternate sources for effective antiviral drugs.The aim of the present study was to screen antiviral potential of gymnemagenol(C30H50O4)previously extracted from leaves of Gymnema sylvestre.The fish nodavirus,grouper nervous necrosis virus(GNNV)in infected Sahul Indian Grouper Eye(SIGE)cell lines were used to study the antiviral activity of gymnemagenol under in vitro conditions.The susceptibility of the virus to gymnemagenol was confirmed by measuring the viral titre(TCID50 mL?1)in virus-infected SIGE cells every 24 h.Gymnemagenol at 20 μg mL?1 inhibited the prolifera-tion of GNNV to 53% at the end of the 6th d by inhibiting the proliferation of GNNV-infected SIGE cells.The viable SIGE cells were reduced to 47% as determined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.The viral titre(TCID50 mL?1)was also reduced to log 2.8 at the end of the 7th d in gymnemagenol-treated SIGE cells after inoculated with GNNV when compared to untreated control SIGE cell viral titre(log 4.1).Based on our results it can be concluded that gymnemagenol could be used as an antiviral agent against GNNV infection.     

An acoustic emission landslide early warning system for communities in low-income and middle-income countries

Early warning systems for slope instability are needed to alert users of accelerating slope deformation behaviour, enable evacuation of vulnerable people, and conduct timely repair and maintenance of critical infrastructure. Communities exposed to landslide risk in low- and middle-income countries seldom currently instrument and monitor slopes to provide a warning of instability because existing techniques are complex and prohibitively expensive. Research and field trials have demonstrated conclusively that acoustic emission (AE) monitoring can be an effective approach to detect accelerating slope movements and to subsequently communicate warnings to users. The objective of this study was to develop and assess a simple, robust, low-cost AE monitoring system to warn of incipient landslides, which can be widely deployed and operated by communities globally to help protect vulnerable people. This paper describes a novel AE measurement sensor that has been designed and developed with the cost constrained to a few hundred dollars (US). Results are presented from physical model experiments that demonstrate performance of the AE system in measuring accelerating deformation behaviour, with quantifiable relationships between AE and displacement rates. Exceedance of a pre-determined trigger level of AE can be used to communicate an alarm to users in order to alert them of a slope failure. Use of this EWS approach by communities worldwide would reduce the number of fatalities caused by landslides.     

H2O on Io? IR spectra of SO2/H2O mixed ices in the 5000-450 cm−1 region

Laboratory transmission IR spectra of relatively thick films (up to 500 m) of mixed H₂O and SO₂ ices were measured at several temperatures between 10 and 130 K in the range 5000-450 cm^–1. In addition to the strong features due to crystalline SO₂ the spectra reveal bands at 3668 cm^–1, 3634 cm^–1 (with some structure) and 3300 cm^–1 which are identified with H₂O in SO₂ environment. Also, there is no overlap between any of the H₂O bands with the 3584 cm^–1 band of SO₂ at any temperature in the above range. The implication of this result is that H₂O, if present on Io, must be far less than 1 part in 10⁵ SO₂.     

The two mooring dolphin concept for exposed tanker terminals

The conventional design for a tanker terminal provides for two or more mooring dolphins on each side of the breasting dolphins. Head and stern lines are attached to the outer mooring dolphins and breast lines to the inner mooring dolphins. In exposed locations, the expense of construction may be significantly reduced if a way can be found to reduce the number of mooring dolphins required for the safe mooring of ships at a fixed berth.This paper, based on studies for a proposed terminal for tankers from 25,000 to 100,000 DWT in the Bay of Fundy in Eastern Canada, discusses the possibility of reducing the total number of mooring dolphins from four to two. Results of a static analysis of mooring loads due to wind and current and a hydraulic model test for mooring loads due to waves are presented.Operational aspects of the two mooring dolphin layout are discussed. It is concluded that the two mooring dolphin concept is an efficient mooring arrangement which will reduce the cost of fixed berth terminals. It is noted, however, that many of the smaller, older tankers in the world fleet do not have adequate mooring equipment to use such a berth and it is recommended that the necessary change in deck equipment be made to allow for such an arrangement. It is also recommended that ship personnel acquaint themselves with mooring procedures using breast and spring lines alone.