The role of low-frequency intraseasonal oscillations in the anomalous Indian summer monsoon rainfall of 2002

We analyze the dynamical features and responsible factors of the low-frequency intraseasonal time scales which influenced the nature of onset, intensity and duration of active/break phases and withdrawal of the monsoon during the anomalous Indian summer monsoon of 2002 - the most severe drought recorded in recent times. During that season, persistent warm sea surface temperature anomalies over the equatorial Indian Ocean played a significant role in modulating the strength of the monsoon Hadley circulation. This in turn affected the onset and intense break spells especially the long break during the peak monsoon month of July. Strong low-frequency intraseasonal modulations with significant impact on the onset and active/break phases occurred in 2002 which were manifested as a good association between low-frequency intraseasonal oscillations and the onset and active/break spells. Further, SST anomalies over the equatorial Indo-Pacific region on low-frequency intraseasonal time scales were found to affect the equatorial eastward and thereby off-equatorial northward propagations of enhanced convection over the Indian region. These propagations in turn modulated the active/break cycle deciding the consequent severity of the 2002 drought

NEUTRACUETICAL EVALUATION OF BOERHAVIA DIFFUSA L.

Objective: Boerhavia diffusa a tropical herb has been a subject of keen interest in phytochemical and pharmacological research due to its excellent medicinal values. The stress and need for quality control and standardisation of medicinal preparations from plants is gaining more importance today in view of the commercialization of drug formulations.Methods: WHO recommends various physicochemical, proximate and nutritive standards so that uniformity in composition and effectiveness is maintained? All the analysis was done using standard protocols.Results: The nutraceutical evaluation of the plant gives an insight into its value as a medicinal as well as highly nutritious one, safe for consumption both as a medicine and as a natural source for antioxidant activities.Conclusion: Thus the present finding suggests that B. diffusa have a promising potential not only to cure ailments but to maintain a healthy life

Multiscale periodicities in aerosol optical depth over India

Aerosols exhibit periodic or cyclic variations depending on natural and anthropogenic sources over a region, which can get modulated by synoptic meteorological parameters such as winds, rainfall and relative humidity, and long-range transport. Information on periodicity and phase in aerosol properties assumes significance in prediction as well as to examine the radiative and climate effects of aerosols including its association with changes in cloud properties and rainfall. Periodicity in aerosol optical depth, which is a columnar measure of aerosol distribution, is determined using continuous wavelet transform over 35 locations in India. Continuous wavelet transform is used in the study because it is better suited to extract the periodic and local modulations present at various frequency ranges, as these features are invisible in conventional methods such as Fourier Transform. Monthly mean aerosol optical depths (AODs) from MODerate Resolution Imaging Spectroradiometer (MODIS) on board the Terra satellite from January 2001 to December 2012 are used. Annual and quasi-biennial oscillations (QBO) in AOD are evident in addition to the weak semi-annual and quasi-triennial. The semi-annual and annual oscillations are consistent with the seasonal and yearly cycle of variations in AODs. The 40-month periodicity indicates the presence of long term correlations in AOD. The observed periodicities in MODIS Terra AODs are also evident in the ground-based AOD measurements made over Kanpur in the Indo-Gangetic Plain. The phase of the periodicity in AOD is stable in the mid-frequency range, while local disturbances in the high-frequency range and long term changes in the atmospheric composition give rise to unstable phases in low-frequency range. That modulations in AOD over one location/region can influence the other is revealed by the presence of phase relation among different locations

Characteristics of spectral aerosol optical depths over India during ICARB

Spectral aerosol optical depth (AOD) measurements, carried out regularly from a network of observatories spread over the Indian mainland and adjoining islands in the Bay of Bengal and Arabian Sea, are used to examine the spatio-temporal and spectral variations during the period of ICARB (March to May 2006). The AODs and the derived Angstrom parameters showed considerable variations across India during the above period. While at the southern peninsular stations the AODs decreased towards May after a peak in April, in the north Indian regions they increased continuously from March to May. The Angstrom coefficients suggested enhanced coarse mode loading in the north Indian regions, compared to southern India. Nevertheless, as months progressed from March to May, the dominance of coarse mode aerosols increased in the columnar aerosol size spectrum over the entire Indian mainland, maintaining the regional distinctiveness. Compared to the above, the island stations showed considerably low AODs, so too the northeastern station Dibrugarh, indicating the prevalence of cleaner environment. Long-range transport of aerosols from the adjoining regions leads to remarkable changes in the magnitude of the AODs and their wavelength dependencies during March to May. HYSPLIT back-trajectory analysis shows that enhanced long-range transport of aerosols, particularly from the west Asia and northwest coastal India, contributed significantly to the enhancement of AOD and in the flattening of the spectra over entire regions; if it is the peninsular regions and the island Minicoy are more impacted in April, the north Indian regions including the Indo Gangetic Plain get affected the most during May, with the AODs soaring as high as 1.0 at 500 nm. Over the islands, the Angstrom exponent (α) remained significantly lower (~1) over the Arabian Sea compared to Bay of Bengal (BoB) (~1.4) as revealed by the data respectively from Minicoy and Port Blair. Occurrences of higher values of α, showing dominance of accumulation mode aerosols, over BoB are associated well with the advection, above the boundary layer, of fine particles from the east Asian region during March and April. The change in the airmass to marine in May results in a rapid decrease in α over the BoB

Physical properties of tender coconut

Not AvailableThe physical properties such as tender coconut size, weight, husk thickness, and husk moisture tender content play a vital role in the development of an efficient and ergonomic trimming machine. The important physical properties of tender coconuts of cultivars namely Kulasekaran Green Dwarf (KGD), Andaman Giant Tall (AGT), Ganga Bondam (GB), Malayan Orange Dwarf (MOD), and Chowghat Orange Dwarf (COD) were determined. The important properties including weight, diameter, height, husk thickness, husk moisture content, shell diameter, shell height, and shell thickness were high for nuts of AGT and low for COD nuts. The average bulk density, true density, and porosity of AGT were 332.47 kg m−3, 1,196.67 kg m−3, and 72.21%, respectively. The husk weight and volume of water of AGT were 87.77% and 12.39% high, respectively, compared with COD. In the correlation study, the coconut weight correlated positively (r = 0.791) with the diameter and vertical distance between the shell and the fruit base (r = 0.813). The principal component analysis suggested that the cultivars GB, KGD, and MOD have similar physical properties to COD and AGT. Thus, the present investigation documents crucial basic information to design an efficient and superior tender coconut trimming machine.ICA

Studies on the influence of metal oxides on the galvanic characteristics of hot-dip zinc coating

In the present work, hot dip zinc coating incorporated with various composite was developed. The effect of ZnO and V2O5 in the galvanizing characteristics of zinc coating was studied with a view to apply the coating for functional application. The pretreatment conditions and bath compositions were fixed based on the available literatures and on the preliminary test results. Different electrochemical techniques were followed to study the corrosion tolerance of the coating. The presence of ZnO had a beneficial influence on the protection span of the coating compared to that of V2O5. The presence of composite reinforced inner layer influenced the alloying reaction between Fe and Zn. The surface topography of the coating was also improved due to the metal oxide incorporation