Total Lipid and Fatty Acid Classes in Decomposing Mangrove Leaves of <Emphasis Type="Italic">Bruguiera gymnorrhiza</Emphasis> and <Emphasis Type="Italic">Kandelia candel</Emphasis>: Significance with respect to Lipid Input

Changes in the concentration of total lipid and fatty acids (FAs) during the decomposition of mangrove leaves were investigated by field experiments using yellow leaves of Bruguiera gymnorrhiza (L.) Lamk. and Kandelia candel (L.) Druce, in order to quantify mangrove contribution to lipid and fatty acid inputs to marine sediments. Total lipid and total FA in the fresh (green and yellow) and decomposing leaves of both species were significantly higher during winter than summer. During decomposition, total lipid content and FA concentration, in particular branched chain fatty acids (BrFAs) and bacterial fatty acids (BFAs), increased to a maximum concentration in 45 days during winter and in 17 days during summer. Lipids were lost faster in K. candel leaf detritus than in B. gymnorrhiza leaf detritus in which >90% of the total lipid original weight was lost during the summer experiment and <60% during the winter experiment. The changes in the concentrations of total lipids and FAs in the decomposing leaves also indicate that mangrove leaves are significant sources of fatty acids and probably other lipid compounds to estuarine ecosystems and that tidal waters transport the lipids and FAs adsorbed to particulate matter from mangroves to adjacent estuarine sediments and the ocean.     

Hydrodynamic coefficients for vertical circular cylinders at finite depth

Hydrodynamics coefficients for vertical circular cylinders at finite water depth are obtained and presented for different depth to radius and draft to radius ratios. A summary of equations for computer application is presented. Limiting values for heave added mass for zero frequency are discussed. A matching technique is used to satisfy the continuity of pressure and normal velocities.     

Delineation and assessment of Central Indian Suture through lineament extraction approach using Remote Sensing and Geographic Information System

Lineament extraction approach allowed mapping of larger number of lineaments in a classical manner in tectonic and structural studies. In the present study, various techniques were adopted to extract lineaments using Landsat ETM+ images. To remove the biasness of the images, some pre-processing techniques like stream ordering, band differencing, colour texturing were employed to enhance the edges of the structural features. Extracted lineaments and its distribution and orientation were mapped using ArcGIS Spatial analyst tool. Results of the study showed maximum number of lineaments were oriented in the ENE–SWS direction with 63° overall inclination. Accuracy assessment and validation were made with respect to visual interpretation and overlaying the lineament on Digital Topographic Model as well as with respect to an existing geological lineament map of the study site. The result of accuracy assessment indicates higher compatibility of Central Indian Suture with the geological map of the study area.     

An approximated method for the solution of elliptic problems in thin domains: Application to nonlinear internal waves

Realistic numerical simulations of nonlinear internal waves (NLIWs) have been hampered by the need to use computationally expensive nonhydrostatic models. In this paper, we show that the solution to the elliptic problem arising from the incompressibility condition can be successfully approximated by a few terms (three at most) of an expansion in powers of the ratio (horizontal grid spacing)/(total depth). For an n dimensional problem, each term in the expansion is the sum of a function that satisfies a one-dimensional second-order ODE in the vertical direction plus, depending on the surface boundary condition, the solution to an n-1 dimension elliptic problem, an evident saving over having to solve the original n-dimensional elliptic problem. This approximation provides the physically correct amount of dispersion necessary to counteract the nonlinear steepening tendency of NLIWs. Experiments with different types of NLIWs validate the approach. Unlike other methods, no ad hoc artificial dispersion needs to be introduced.     

Improved geological mapping using landsat-5 TM data in Weixi area, Yunnan province China

Different image processing algorithms have been evaluated in the context of geological mapping using Landsat TM data. False color composites, the principal component imagery, and IHS decorrelation stretching method for Landsat-5 TM data have been found useful for delineating the regional geological features, mainly to provide the maximum geological information of the studied area . The study testifies that using which image processing yields best results for geological mapping in arid and semiarid regions by preserving morphological and spectral information. Generally, the studied area can be divided into three main geological units: Basaltic intrusive rocks, Metamorphic with varying intensities and Sedimentary rocks.     

中国兰坪地区铜﹑铅﹑锌矿潜在分布的GIS预测模型(英文)

Mineral resource potential mapping is a complex analytical process,which requires the consideration and the inte-gration of a number of spatial evidences like geological,geomorphological,and wall rock alteration.The aim of this paper is to establish mineral exploration model for copper,lead,and zinc in Lanping basin area using the capability of analytical tools of Geographic Information System(GIS) and remote sensing data to generate maps showing favorable mineralized area.The geo-exploration dataset used f...     

Dynamics of particle flux and carbon export in the northwestern Mediterranean Sea: A two decade time-series study at the DYFAMED site

The DYFAMED time-series station, located in the open Ligurian Sea, is one of the few pluriannual flux programs in the world and the longest in the Mediterranean Sea. The trap data series is one of only three multi-decadal data sets in existence, and it provides flux information for an environment that is distinct from the other long-term data sets. At DYFAMED, downward fluxes of particles, carbon and other major elements have been regularly measured with sediment traps since 1986 at fixed depths of 200 and 1000 m. An overview is presented of the main trends of particle and carbon fluxes observed during the period 1988–2005, period when the mooring was located on the northern side of the Ligurian Sea. In spite of considerable interannual variability, fluxes displayed a marked seasonal pattern with the highest fluxes occurring during winter and spring and lowest fluxes throughout the stratified season (summer–autumn). Organic carbon fluxes measured at both depths were highly variable over time, ranging from 0.3 to 59.9 (mean 6.8) mg C m⁻² d⁻¹ at 200 m, and from 0.2 to 37.1 (mean 4.3) mg C m⁻² d⁻¹ at 1000 m. Mass fluxes were maximal in winter, whereas carbon fluxes were maximal in late spring. Reasonably good agreement existed between particle fluxes at both depths over the years, indicating a relatively efficient and rapid transport of particles from the upper ocean to the deep sea. However, during certain periods mass flux increased with depth suggesting lateral inputs of particles that by-pass the upper trap. Since 1999, the system has apparently shifted towards an increasing occurrence of extreme flux events in response to more vigorous mixing of the water column during the winter months. Although annual mass fluxes have increased in the last years, mean POC fluxes have not substantially changed over time, due mainly to lower carbon contents of the sinking particles during maxima of mass flux.     

There’s more to the picture than meets the eye: Sampling microphytobenthos in a heterogeneous environment

Distributions of microphytobenthos are highly heterogeneous at scales as small as a few centimetres. However, the sampling protocols currently used for the absolute determination of microphytobenthos biomass through chlorophyll a concentration measurements in surface sediments are too limited to take this variability into account, typically relying on 3-5 samples taken within a randomly located 1 m² quadrat in a given environment. We address this issue by objectively and quantitatively inferring the minimum number of samples required to obtain reliable estimates of microphytobenthos biomass on the basis of high-resolution sub-sampling (225 regularly spaced samples) within each of nine 1 m² quadrats at an unvegetated sheltered intertidal sandbank of the Gold Coast (Queensland, Australia). The results were generalised using data obtained in previous studies on an exposed sandy shore and on sheltered estuarine sandy muds of the Eastern English Channel. Estimates of chlorophyll a concentration exhibited a high degree of heterogeneity, both between and within quadrats. The number of samples needed to estimate the average chlorophyll a concentration, and hence mean microphytobenthos biomass with 95% confidence intervals, ranged from 15 to 115, and mainly depended on the presence of global and local gradients within the quadrats. These results have major implications for intertidal ecology by implying a possible systematic bias in the measurement of both microphytobenthos biomass and production of up to 40%. Finally, we emphasise that this issue can be circumvented using field spectrometry or PAM fluorescence measurements coupled with traditional sediment sampling techniques, and urge for unified protocols to be adopted for the routine use of these combined methods.     

Evolution and Fragmentation of Wide-Angle Wind Driven Molecular Outflows

We present two dimensional cylindrically symmetric hydrodynamic simulations and synthetic emission maps of a stellar wind propagating into an infalling, rotating environment. The resulting outflow morphology, collimation and stability observed in these simulations have relevance to the study of young stellar objects, Herbig-Haro jets and molecular outflows. Our code follows hydrogen gas with molecular, atomic and ionic components tracking the associated time dependent molecular chemistry and ionization dynamics with radiative cooling appropriate for a dense molecular gas. We present tests of the code as well as new simulations which indicate the presence of instabilities in the wind-blown bubble’s swept-up shell.     

Performance Enhancement of Solar Latent Heat Thermal Storage System with Particle Dispersion — an Exergy Approach

Phase change material (PCM) employed latent heat thermal storage (LHTS) system has been showing good potential over the years for energy management, particularly in solar energy systems. However, enhancement in thermal conductivity of PCMs is emphasized as PCMs are known for their poor thermal conductivity. In this work, the thermal performance of a shell and tube LHTS module containing PCM‐metal particles composite is investigated while charging and is compared with that of pure PCM system. The effect of particle dispersion on latent heat capacity of pure PCM is also analyzed. Enthalpy based governing equations are solved numerically adopting FLUENT code. Exergy based performance evaluation is taken as a main aspect. The numerical results are presented for various operating conditions of heat transfer fluid (HTF) and indicate considerable performance improvement of the system when particles are dispersed.