The spatial distribution patterns of surficial sediment samples from different sedimentary domains （shallow to deep-sea regions） of the eastern Arabian Sea were studied using sediment proxies viz. environmental magn...The spatial distribution patterns of surficial sediment samples from different sedimentary domains （shallow to deep-sea regions） of the eastern Arabian Sea were studied using sediment proxies viz. environmental magnetism, geochemistry, particle size and clay mineralogy. Higher concentrations of magnetic minerals （high Xlf） were recorded in the deep-water sediments when compared with the shallow water sediments. The magnetic mineralogy of one of the shallow water samples is influenced by the presence of bacterial magnetite as evidenced from the XARM/Xlf VS. XARM/Xfd biplot. However, the other samples are catchment-derived. The high correlation documented for Xlf, anhysteretic remanent mag- netisation （XARM） and isothermal remanent magnetisation （IRM） with Al indicates that the deep-sea surflcial sediments are influenced by terrigenous fluxes which have been probably derived from the southern Indian rivers, the Sindhu （the Indus） and the Narmada-Tapti rivers. A lower Mn concentration is recorded in the upper slope sediments from the oxygen minimum zone （OMZ） but a higher Mn/AI ratio is documented in the lower slope and deep-sea sediments. Clay minerals such as illite （24-48.5%）, chlorite （14.1-34.9%）, smectite （10.6-28.7%） and kaolinite （11.9-27.5%） dominate the sediments of shallow and deep-sea regions and may have been derived from different sources and transported by fluvial and aeolian agents. Organic carbon （OC） data indicate a low concentration in the shallow/shelf region （well oxygenated water conditions） and deeper basins （increased bottom-water oxygen concentration and low sedimentation rate）. High OC concentrations were documented in the OMZ （very low bottom-water oxygen concentration with high sedimentation rate）. The calcium carbonate concentration of the surface sediments from the continental shelf and slope regions （〈 1800 m） up to the Chagos-Laccadive Ridge show higher concentrations （average - 58%） when compared to deep basin sediments （average - 44%）. Our study demonstrates that particle size as well as magnetic grain size, magnetic minerals and elemental variations are good indicators to distinguish terrigenous from biogenic sediments and to identify sediment provenance.展开更多
The Mobile Ad-hoc Network(MANET)is a dynamic topology that provides a variety of executions in various disciplines.The most sticky topic in organizationalfields was MANET protection.MANET is helpless against various t...The Mobile Ad-hoc Network(MANET)is a dynamic topology that provides a variety of executions in various disciplines.The most sticky topic in organizationalfields was MANET protection.MANET is helpless against various threats that affect its usability and accessibility.The dark opening assault is considered one of the most far-reaching dynamic assaults that deteriorate the organi-zation's execution and reliability by dropping all approaching packages via the noxious node.The Dark Opening Node aims to deceive any node in the company that wishes to connect to another node by pretending to get the most delicate ability to support the target node.Ad-hoc On-demand Distance Vector(AODV)is a responsive steering convention with no corporate techniques to locate and destroy the dark opening center.We improved AODV by incorporating a novel compact method for detecting and isolating lonely and collaborative black-hole threats that utilize clocks and baits.The recommended method allows MANET nodes to discover and segregate black-hole network nodes over dynamic changes in the network topology.We implement the suggested method's performance with the help of Network Simulator(NS)-3 simulation models.Furthermore,the proposed approach comes exceptionally near to the original AODV,absent black holes in terms of bandwidth,end-to-end latency,error rate,and delivery ratio.展开更多
General The International Geoscience Education Organisation organised three Teacher Training Workshops in Goa,Mangaluuru and Bengaluuru during July 2–5,July 7–10 and July 12–15,2015 jointly with the National Centre...General The International Geoscience Education Organisation organised three Teacher Training Workshops in Goa,Mangaluuru and Bengaluuru during July 2–5,July 7–10 and July 12–15,2015 jointly with the National Centre for Antarctic and Ocean Research,St.Aloysius College(Autonomous)and the Karnataka State Council for Science and Technology,which were attended by 17,48 and 63 high school teachers respectively.These were organised as a pilot project to test the impact of such an approach in an Indian setting.展开更多
Pookot is a small freshwater lake situated in the Sahyadri(the Western Ghat)of southern India.We used diffuse reflectance spectroscopy(DRS)and magnetic parameters to characterize the sediment components present in a c...Pookot is a small freshwater lake situated in the Sahyadri(the Western Ghat)of southern India.We used diffuse reflectance spectroscopy(DRS)and magnetic parameters to characterize the sediment components present in a core dating back to~3000 cal.years B.P.DRS data indicate the presence of CaCO_(3),goethite,hematite/goethite,clay minerals and organic carbon in the lake sediments.Based on the down-core variations of the four components,and the values ofχlf(low-field magnetic susceptibility indicative of detrital magnetite)and DRS parameter redness%,we reconstructed the paleoenvironmental history of the region surrounding the lake.展开更多
The principal objectives of IESO,the flag-ship activity of the International Geoscience Education Organisation(IGEO;www.geoscied.org),are to raise higher secondary school students’interest in earth science,to enhance...The principal objectives of IESO,the flag-ship activity of the International Geoscience Education Organisation(IGEO;www.geoscied.org),are to raise higher secondary school students’interest in earth science,to enhance earth science learning of students,to improve teaching of earth science in schools,to forge friendship among young learners from different countries and to promote international cooperation in exchanging ideas and materials about earth science and earth science education.展开更多
The 3^(rd) International Earth Science Olympiad(www.ieso2009.tw/home/home.html)was organized by the National Taiwan Normal University at Taipei,Taiwan.Fifty students from 14 countries participated in the 3^(rd) IESO.F...The 3^(rd) International Earth Science Olympiad(www.ieso2009.tw/home/home.html)was organized by the National Taiwan Normal University at Taipei,Taiwan.Fifty students from 14 countries participated in the 3^(rd) IESO.Four other countries sent Observers.展开更多
基金The magnetic instruments used for this investigation were procured through grants(DOD Sanction No.DOD/11-MRDF/1/48/P/94ODII/12-10-96)under a research project(to RS)sponsored by the erstwhile Department of Ocean Development(now Ministry of Earth Sciences),Government of India
文摘The spatial distribution patterns of surficial sediment samples from different sedimentary domains （shallow to deep-sea regions） of the eastern Arabian Sea were studied using sediment proxies viz. environmental magnetism, geochemistry, particle size and clay mineralogy. Higher concentrations of magnetic minerals （high Xlf） were recorded in the deep-water sediments when compared with the shallow water sediments. The magnetic mineralogy of one of the shallow water samples is influenced by the presence of bacterial magnetite as evidenced from the XARM/Xlf VS. XARM/Xfd biplot. However, the other samples are catchment-derived. The high correlation documented for Xlf, anhysteretic remanent mag- netisation （XARM） and isothermal remanent magnetisation （IRM） with Al indicates that the deep-sea surflcial sediments are influenced by terrigenous fluxes which have been probably derived from the southern Indian rivers, the Sindhu （the Indus） and the Narmada-Tapti rivers. A lower Mn concentration is recorded in the upper slope sediments from the oxygen minimum zone （OMZ） but a higher Mn/AI ratio is documented in the lower slope and deep-sea sediments. Clay minerals such as illite （24-48.5%）, chlorite （14.1-34.9%）, smectite （10.6-28.7%） and kaolinite （11.9-27.5%） dominate the sediments of shallow and deep-sea regions and may have been derived from different sources and transported by fluvial and aeolian agents. Organic carbon （OC） data indicate a low concentration in the shallow/shelf region （well oxygenated water conditions） and deeper basins （increased bottom-water oxygen concentration and low sedimentation rate）. High OC concentrations were documented in the OMZ （very low bottom-water oxygen concentration with high sedimentation rate）. The calcium carbonate concentration of the surface sediments from the continental shelf and slope regions （〈 1800 m） up to the Chagos-Laccadive Ridge show higher concentrations （average - 58%） when compared to deep basin sediments （average - 44%）. Our study demonstrates that particle size as well as magnetic grain size, magnetic minerals and elemental variations are good indicators to distinguish terrigenous from biogenic sediments and to identify sediment provenance.
文摘The Mobile Ad-hoc Network(MANET)is a dynamic topology that provides a variety of executions in various disciplines.The most sticky topic in organizationalfields was MANET protection.MANET is helpless against various threats that affect its usability and accessibility.The dark opening assault is considered one of the most far-reaching dynamic assaults that deteriorate the organi-zation's execution and reliability by dropping all approaching packages via the noxious node.The Dark Opening Node aims to deceive any node in the company that wishes to connect to another node by pretending to get the most delicate ability to support the target node.Ad-hoc On-demand Distance Vector(AODV)is a responsive steering convention with no corporate techniques to locate and destroy the dark opening center.We improved AODV by incorporating a novel compact method for detecting and isolating lonely and collaborative black-hole threats that utilize clocks and baits.The recommended method allows MANET nodes to discover and segregate black-hole network nodes over dynamic changes in the network topology.We implement the suggested method's performance with the help of Network Simulator(NS)-3 simulation models.Furthermore,the proposed approach comes exceptionally near to the original AODV,absent black holes in terms of bandwidth,end-to-end latency,error rate,and delivery ratio.
文摘General The International Geoscience Education Organisation organised three Teacher Training Workshops in Goa,Mangaluuru and Bengaluuru during July 2–5,July 7–10 and July 12–15,2015 jointly with the National Centre for Antarctic and Ocean Research,St.Aloysius College(Autonomous)and the Karnataka State Council for Science and Technology,which were attended by 17,48 and 63 high school teachers respectively.These were organised as a pilot project to test the impact of such an approach in an Indian setting.
基金The magnetic instruments used in this study were procured from grants made available by the erstwhile Department of Ocean Development(now Ministry of Earth Sciences),Government of India,through a research project(DOD/11-MRDF/1/48/P/94-ODII/12-10-96)to RS.
文摘Pookot is a small freshwater lake situated in the Sahyadri(the Western Ghat)of southern India.We used diffuse reflectance spectroscopy(DRS)and magnetic parameters to characterize the sediment components present in a core dating back to~3000 cal.years B.P.DRS data indicate the presence of CaCO_(3),goethite,hematite/goethite,clay minerals and organic carbon in the lake sediments.Based on the down-core variations of the four components,and the values ofχlf(low-field magnetic susceptibility indicative of detrital magnetite)and DRS parameter redness%,we reconstructed the paleoenvironmental history of the region surrounding the lake.
文摘The principal objectives of IESO,the flag-ship activity of the International Geoscience Education Organisation(IGEO;www.geoscied.org),are to raise higher secondary school students’interest in earth science,to enhance earth science learning of students,to improve teaching of earth science in schools,to forge friendship among young learners from different countries and to promote international cooperation in exchanging ideas and materials about earth science and earth science education.
文摘The 3^(rd) International Earth Science Olympiad(www.ieso2009.tw/home/home.html)was organized by the National Taiwan Normal University at Taipei,Taiwan.Fifty students from 14 countries participated in the 3^(rd) IESO.Four other countries sent Observers.
