Morphological Change in the Northern Red River Delta,Vietnam

Coastal erosion has become a worldwide concern, typically in the densely populated Asian mega-river deltas. Severe coastal erosion in the southern Red River Delta(RRD) has been intensively studied. Coastal morphological change in the northern RRD was examined in detail through DEM(Digital Elevation Model) analysis based on time series of bathymetrical maps(1965–2004) and Landsat images(1975–2015) in this study. The results show that the northern RRD is featured by rapid coastal accretion in the past few decades, although suspended sediment flux has dropped by roughly 60% after the completeness of Hoa Binh Dam(HBD) in 1988 and relative sea level rose at 1.9 mm yr~(-1). However, accretion at the outer part of subtidal shoals and platforms was observed to slow down quickly or even turned into erosion in the last two decades. The resuspended sediments from the erosion zone can be transported landward to replenish the inner coastal zone, keeping the latter accretion in the near future to compensate for the sediment discharge decrease from the river. However, this lag effect should be terminated soon if other adverse effects go worse, e.g., damming rivers, sea-level rising, strengthening storms, land reclamation and other poor-designed coastal engineering. Coastal planners and managers should pay full attention to these changes.     

A comparative predictive analysis of weighted overlay,weighted sum and fuzzy logic for mineral prospectivity mapping of precious and base metal mineralizations at north-east of Gümüşhane city,NE Turkey

The study area located south of the Eastern Pontide metallogenic belt (NE Turkey) has an important potential for valuable and base metallic minerals. Geological, tectonic, geochemical, hydrothermal alteration, mineralogical and fluid inclusion characteristics of ore formations in the region have been studied in detail. The purpose of this study is to combine and analyse the acquired spatial data layers in a geographic information system (GIS) environment using knowledge-driven approaches and to identify prospective areas in terms of mineralization. Moreover, evaluating the performance of different knowledge-driven mineral probability modelling results comparatively and quantitatively constitutes the other goal of the study. As a result, in addition to the known mineralization locations, a number of new prospective and favourable areas have been identified for future detailed studies. In addition, it has been found that the mineral predictive map generated using fuzzy logic-OR method produces the best and successful results compared to others.     

Glacier Extent and Volume Change （1966-9000） on the Su-lo Mountain in Northeastern Tibetan Plateau,China

The topographic maps of 1：50, 000 scales, aerial photographs taken in 1966, one Landsat image taken in 1999, and SRTM data from 2000 were used to quantify the losses in area and volume of the glaciers on the Su-lo Mountain, in the northeastern Tibetan Plateau, China in the past 30 years. The total glacier area decreased from 492.9 km^2 in 1966 to 458.2 km^2 in 1999. The volume loss of the studied glaciers reached 1.4 km^3 from 1966 to 2000. This agrees with documented changes in other mountain glaciers of the whole Tibetan Plateau.     

越南北部岩溶特征及其相关环境问题

越南北部属热带季风气候,受东南亚季风影响明显,雨量充沛,气温高,植被发育。它们地处特提斯海槽和环太平洋带两个全球性的构造带交汇处,碳酸盐岩受构造改造强烈,岩溶广泛发育,岩溶地貌类型齐全。与中国西南亚热带、热带岩溶区相比,岩溶发育特征有许多类似之处,但其岩溶泉水有更高的碱度,反映出更强烈的溶蚀作用。随着越南经济发展,岩溶区中的一些环境问题也日益突出,不合理的土地利用,已开始造成土地石漠化等环境问题。      

Isolation and Identification of Lactic Acid Bacteria Isolated from a Traditional Jeotgal Product in Korea

Seventeen lactic acid bacterial strains (LAB) were isolated using MRS agar medium from Jeotgal, a Korean fermented food, purchased at the Jukdo market of Pohang. To identify the strains isolated, they were tested by examining their cell morphologies, gram-staining, catalase activity, arginine hydrolase activity, D-L lactate form and carbohydrate fermentation. According to the phenotypic characteristics, three strains were tent atively identified asLactobacillus spp., ten wereEnterococcus spp. (orStreptococcus spp., orPediococcus spp.) and the rest were Leuconostoc spp. (orWeissella spp.). Five strains among 17 were chosen by preliminary bacteriocin activity test. Four bacterial strains which inhibited both indicator microorganisms were identified by 16S rRNA sequencing. The results are as follows; Leuconostoc mesenteroides (HK 4),Leuconostoc mesenteroides (HK 5),Leuconostoc mesenteroides(HK 11),Streptococcus salivarius(HK 8). In order to check LAB which are showing a high survival rate in gut, we investigated three strains inhibiting both indicator microorganisms in artificial gastric acid and bile juice -all except HK8. The three strains mentioned above grew in extreme low acid conditions.     

Estimation of the PAR irradiance ratio and its variability under clear-sky conditions at ieodo in the east china sea

Determining ‘photosynthetically active radiation’ (PAR) is a key part of calculating phytoplankton productivity in a biogeochemical model. We explore the daily and seasonal variability in the ratio of PAR irradiance to total irradiance that occurred at Ieodo Ocean Research Station (IORS) in the East China Sea under clear-sky conditions in 2004 using a simple radiative transfer model (RTM). Meteorological data observed at IORS and aerosol optical properties derived from Aerosol Robotic Network observations at Gosan are used for the RTM. Preliminary results suggest that the use of simple PA R irradianceratio values is appropriate in calculating phytoplankton productivity as follows: an average of 0.44 (±0.01) in January to an average of 0.48 (±0.01) in July, with average daily variabilities over these periods of about 0.016 (±0.008) and 0.025 (±0.008), respectively. The model experiments demonstrate that variations in the major controlling input parameters (i.e. solar zenith angle, precipitable water vapor and aerosol optical thickness) cause PAR irradiance ratio variation at daily and seasonal timescales. Further, increases (>0.012) in the PAR irradiance ratio just below the sea-surface are positively correlated with high solar zenith angles and strong wind stresses relative to those just above the sea-surface.     

Effect of saline intrusion on the properties of cohesive soils in the Red River Delta,Vietnam

Abstract

This study conducted a series of laboratory experiments and established numerical models on selected undisturbed soil samples in the Red River Delta (RRD) to determine the effect of change in soils intruded by saline water. The variation in the technical parameters of soils was verified in soils fully saturated by solution of four salt concentrations, that is, 0.0, 9.9, 19.8, and 33.0?g/L. Results show that the content and composition of clay minerals in cohesive soils before and after saline intrusion are unchanged. The same finding is obtained for clay after removing absorbed water layer by using a centrifuge apparatus. The zeta potential and settlement velocity of soils in the RRD increase when salt is added to the saturated solution. Similarly, the deformation of soils increases proportionally with the salt concentrations of that solution. This result is attributed to the linear decrease in deformation modulus. The decrease in modulus versus salinities is nearly consistent for pressure stages from 100 to 400?kPa. The safety factor of bearing capacity also decreases linearly with salinities. The decrease reaches 12.5–16.3% when soils are in the maximum saline solution. All these changes are considered as the degradation of soils in saline media.     

Experimental evaluation of dynamic characteristics of seesaw energy dissipation system for vibration control of structures

Seesaw energy dissipation system (SEDS), a vibration control system used to provide enhanced seismic protection, has been proposed and investigated numerically. Because of its complicated arrangement, verification experiments are necessary to demonstrate the SEDS damping capacity. This paper presents the results of experimental investigation of the SEDS using fluid viscous dampers. Free vibration tests are conducted to demonstrate the SEDS damping capacity. Results of the free vibration test show that the SEDS has sufficient damping capacity for reduction of the seismic response of the frames. Parametric experimental investigations of the SEDS were conducted, the results of which demonstrate the effects of the system parameter on the damping capacity. Copyright © 2014 John Wiley & Sons, Ltd.