Satellite-observed changes in terrestrial vegetation growth trends across the Asia-Pacific region associated with land cover and climate from 1982 to 2011

The Asia-Pacific (AP) region has experienced faster warming than the global average in recent decades and has experienced more climate extremes, however little is known about the response of vegetation growth to these changes. The updated Global Inventory Modeling and Mapping Studies third-generation global satellite Advanced Very High Resolution Radiometer Normalized Difference Vegetation Index dataset and gridded reanalysis climate data were used to investigate the spatiotemporal changes in both trends of vegetation dynamic indicators and climatic variables. We then further analyzed their relations associated with land cover across the AP region. The main findings are threefold: (1) at continental scales the AP region overall experienced a gradual and significant increasing trend in vegetation growth during the last three decades, and this NDVI trend corresponded with an insignificant increasing trend in temperature; (2) vegetation growth was negatively and significantly correlated with the Pacific Decadal Oscillation index and the El Niño/Southern Oscillation (ENSO) in AP; and (3) at pixel scales, except for Australia, both vegetation growth and air temperature significantly increased in the majority of study regions and vegetation growth spatially correlated with temperature; In Australia and other water-limited regions vegetation growth positively correlated with precipitation.     

Study of deposition of fine sediment within the pores of a coarse sediment bed stream

Elaborate experiments were performed in a 30 m long, 0.5 m deep and 0.2 m wide laboratory flume to study the process of infiltration of fine sediment into the pores of coarse sediment forming the channel bed material. Different concentrations of suspended load of fine sediment of size 0.064 mm were passed over the channel bed made up of three different types of coarse sediments; two uniform and one nonuniform. The proportion of fine sediment infiltrated into the pores of bed material for each equilibrium concentration of suspended load of fine sediment in the flow was studied during several experimental runs. The proportion of fine sediment within the pores of bed material increased with an increase in the equilibrium concentration of suspended load of fine sediment in the flow. This process continued till the pores within the coarse sediment bed were filled up to the capacity with the fine sediment transported by the flow in suspension. The theoretical value was identified for limit for maximum proportion of fine sediment that can be present within the pores of bed material. On further increase in the concentration of suspended load of fine sediment in the flow, deposition of fine sediment occurs on the surface of the flume bed in the form of ripples of the fine sediment. This condition is defined as 'depositional condition'. Experimental observations on these and related aspects are presented herein.     

Cavity radius estimation for contained peaceful nuclear explosions—An analytic approach

An analytical method based on Penny-Taylor model has been modified and applied for the estimation of the final cavity radius for contained peaceful nuclear explosions. The calculated cavity radii for some nuclear explosions in granite, alluvium and sandstone rocks are in good agreement with measured values.     

Spherical radiation-driven shock waves in a non-uniform atmosphere

Similarity solutions are obtained for spherical radiation-driven shock waves propagating in a non-uniform atmosphere at rest obeying a density power law. Approximate analytical solutions are also obtained and found to be in good agreement with the numerical solutions. The effect of the parameter characterizing the initial density distribution of the gas on solutions of the flow field is studied in detail. It is also shown analytically that the shock wave propagates as an overdriven detonation.     

Estimation of inherent optical properties using quasi-analytical algorithm along the coastal waters of southeast Arabian Sea

Ocean Dynamics - An integrated Satlantic hyperspectral profiler was used to collect radiometric quantities and fluorescence up to a depth of 50 m. Remote sensing reflectance (rrs)...     

Storm surge vulnerability along Chennai–Cuddalore coast due to a severe cyclone THANE

A very severe cyclonic storm ‘Thane’ developed over the Bay of Bengal during 25–30 December 2011, crossed the Tamilnadu coast between Pondicherry and Cuddalore (southeast coast of India) in early hours of 30 December with a wind speed 120–140 km/h. The offshore tide record reveals that the surge started to generate around 1100 hours on 29 December 2011 with a height 0.4 m and later raised to 0.68 m at the time of land fall, that is, early hours (0000 hours) of 30 December 2011. Field reconnaissance survey on surge run-up and inundation distance at 15 selected locations of cyclone affected areas reveals that the vulnerability levels are highly variable along the coast. The inundation distance extended up to 30–230 m landward from the shoreline and run-up reached to 1.6–3.2 m above chart datum depending upon the cross-shore geometry of the location. In the areas (Verranampattinam, Chinamudaliyar kuppam and Silver beach) near cyclone landfall, the run-up was up to 2.5–3.2 m and the inundation distance extended up to a maximum of 230 m. However, in the areas located about 150 km north of cyclone landfall, the run-up limited from 1.6 to 1.7 m and the inundation distance extended up to only a maximum of 169 m. The inundation distance is mainly influenced by the slope of the beach. In the areas having beach slope between 1 in 135 and 1 in 220, the inundation distance was 210–230 m. However, in the areas having beach slope 1 in 17 to 1 in 34, the inundation distance is restricted between 35 and 50 m.     

Speciation of aqueous Ni(II)-carboxylate and Ni(II)-fulvic acid solutions: Combined ATR-FTIR and XAFS analysis

Aqueous solutions containing Ni(II) and a series of structurally related carboxylic acids were analyzed using attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) and Ni K-edge X-ray absorption fine structure spectroscopy (XAFS). XAFS spectra were also collected for solutions containing Ni²⁺ and chelating ligands (ethylenediaminetetraacetic acid, nitrilotriacetic acid (NTA)) as well as soil fulvic acid. Limited spectral changes are observed for aqueous Ni(II) complexes with monocarboxylates (formate, acetate) and long-chain polycarboxylates (succinate, tricarballylate), where individual donor groups are separated by multiple bridging methylene groups. These spectral changes indicate weak interactions between Ni(II) and carboxylates, and the trends are similar to some earlier reports for crystalline Ni(II)-acetate solids, for which X-ray crystallography studies have indicated monodentate Ni(II)-carboxylate coordination. Nonetheless, electrostatic or outer-sphere coordination cannot be ruled out for these complexes. However, spectral changes observed for short-chain dicarboxylates (oxalate, malonate) and carboxylates that contain an alcohol donor group adjacent to one of the carboxylate groups (lactate, malate, citrate) demonstrate inner-sphere metal coordination by multiple donor groups. XAFS spectral fits of Ni(II) solutions containing soil fulvic acid are consistent with inner-sphere Ni(II) coordination by one or more carboxylate groups, but spectra are noisy and outer-sphere modes of coordination cannot be ruled out. These molecular studies refine our understanding of the interactions between carboxylates and weakly complexing divalent transition metals, such as Ni(II).     

Seasonal variation in temperature and salinity in the Gautami-Godavari estuary

Variation of temperature and salinity in the lower 22 km stretch of the Gautami-Godavari estuary are reported during four different seasons; hot-weather, south-west monsoon, post-monsoon and winter seasons. The seasonal variation in temperature is small, with a high of about 30°C during hot-weather season and a low of about 26°C during winter season. Unlike temperatures, the salinities in the estuary show large seasonal fluctuations. During south-west monsoon surface salinities were low (0 to 8‰) due to high fresh water run off into the estuary. During hot-weather season surface salinities of 25 to 30‰ were observed due to negligible fresh water run off.     

Histopathological changes in grass shrimp exposed to chromium, pentachlorophenol and dithiocarbamates

This report deals with the histopathological/ultrastructural changes in various tissues of grass shrimp (Palaemonetes pugio) exposed to hexavalent chromium, pentachlorophenol (PCP) and two dithiocarbamate formulations: Aquatreat DNM-30® (15 % sodium dimethyl dithiocarbamate plus 15 % disodium ethylene bis-dithiocarbamate) and Busan-85® (50 % potassium dimethyl dithiocarbamate). The pathological alterations induced by dithiocarbamates and PCP were most severe and first evident in the gills. Of the biocides tested, the dithiocarbamates caused the most extensive branchial damage—the so-called black gill syndrome, involving early melanization and eventual lamellar truncation. Hexavalent chromium, on the other hand, did not induce marked changes in the gills, but it caused invasive melanized cuticular lesions (particularly at the articulations of the pereiopods, pleopods and abdominal segments). Additionally, chromium caused apparent labyrinth hypoactivity in the antennal glands, whereas the dithiocarbamates seemed to induce labyrinth hyperactivity. Hepatopancreatic histopathology was more severe in shrimp exposed to chromium and PCP than in dithiocarbamate-exposed shrimp. The apparent mitotic activity in the hepatopancreas was increased in Aquatreat-exposed shrimp and suppressed in chromium-exposed shrimp; many mitotic figures in the latter case were abnormal. All four compounds caused varying degrees of midgut epithelial hypertrophy, cytoplasmic vacuolization and diminution of basal tubular endoplasmic reticulum, but only PCP caused widespread rupture of midgut epithelial cell apices. Additional notable ultrastructural anomalies included: mitochondrial compartmentalization in PCP-exposed shrimp; mitochondrial fusion in dithiocarbamate-exposed shrimp; and unusual intranuclear inclusions in different tissues of chromium-exposed shrimp. These pathological changes point to differences in the mechanisms of pollutant toxicity and indicate their potential use in the biological monitoring of aquatic pollutants.     

A knowledge based expert system for design of berthing structures

Rapid growth in the water transport system demands the construction of more port and harbour structures. Berthing structures are constructed in ports and harbours to provide facilities such as berthing and mooring of vessels, loading and unloading of cargo and embarking and disembarking of passengers. Quays, wharfs, piers, jetties and dolphins are the most widely used berthing structures. The construction and maintenance of these structures are very expensive and, therefore, the most economical design should be adopted. These structures will be checked against limit state of crack, which is important in respect to preventing corrosion. A knowledge based expert system, KNOWBESTD, has been developed using LEVEL5 OBJECT for the design of berthing structures. This paper describes the development of KNOWBESTD and illustrates the design of a typical berthing structure.