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Engineering（科研） 2013年第3期5卷 237-244页

作者： Kenneth S. Okiongbo Godwin Ogobiri Department of Geology & Physics Niger Delta University Bayelsa State Nigeria

The corrosivity of the top three metres of the soil along a pipeline route was determined using soil electrical resistivity for the emplacement of a conduit intended to serve as a gas pipeline. Fifty-six Schlumberger vertical electrical soundings (VES) were carried using a maximum current electrode separation ranging between 24 - 100 m at 2.0 km interval. The data was interpreted using a 1D inversion technique software (1X1D, Interpex, USA). Model resistivity values were classified in terms of the degree of corrosivity. Generally, the sub-soil condition along the pipeline route is non-aggressive but being slightly or moderately aggressive in certain areas due to local conditions prevailing at the measuring stations. Based on the corrosivity along the pipeline route, appropriate cathodic protection methods are prescribed.

关键词： Soil Corrosivity Geoelectrical Pipeline Groundbed Niger delta

Assessing the Impacts of High Speed Rail Development in China’s Yangtze River delta Megaregion

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Journal of Transportation Technologies 2013年第2期3卷 113-122页

作者： Xueming Chen L. Douglas Wilder School of Government and Public Affairs Virginia Commonwealth University Richmond USA

This paper assesses the impacts of high speed rail (HSR) development in the Yangtze River delta (YRD) Megaregion, China. After giving an introduction and conducting a literature review, the paper proposes a pole-axis-network system (PANS) model guiding the entire study. On the one hand, the HSR projects in the YRD Megaregion are expected to generate significant efficiency-related transportation and non-transportation benefits. As a result, the spillover effects from Shanghai and other major cities (poles) will greatly promote the urban and regional developments along the major HSR corridors (axes), and the entire megaregion will become more integrated economically, socially, and culturally. But, on the other hand, the HSR projects will also create serious social and geographic inequity issues, which need to be addressed as soon as possible in a proper way. This empirical study confirms the PANS model proposed.

关键词： High Speed Rail China Yangtze River delta Megaregion Impacts

Palynological Study of OSE 1 Well in Offshore Niger delta Basin: Implications for Age, Paleoclimate and Depositional Paleoenvironment

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International Journal of Geosciences 2019年第10期10卷 860-883页

作者： Osazuwa Abifade Ogbahon Department of Applied Geology The Federal University of Technology Akure Nigeria

Palynological study of 45 ditch samples from sedimentary successions penetrated by OSE 1 well located offshore western Niger delta Basin was undertaken to determine the age of the sediment and reconstruct the paleoclimate and depositional paleoenvironment. All the analyzed samples were composited at 30 ft from stratigraphic depth interval of 6330 to 9010 ft. The lithologic composition comprised mainly of brownish grey or light grey, fine-grained shales with a gypsiferous horizon near the bottom. Palynological slides were prepared following standard palynological preparation procedures of sample maceration with hydrochloric (HCl) and hydrofluoric (HF) acids. The samples yielded moderately well-preserved, low to high diversity palynomorph assemblages of 58 taxa comprising 29 pollen grains, 9 pteridophic spores, 17 dinoflagellates, one acritarch, one freshwater algae and a fungi spore. The stratigraphic distribution of microflora assemblages was highly variable. The assemblage abundance was dominated by pollen and spores. The retrieved pollen grains included Monoporites annulatus, Sapotaceoidaepollenites sp. Psilatricolporites crassus, Psilatricolporites sp., Zonocostites ramonae, Retitricolporites irregularis, Monocolpites marginatus, Monocolpites sp., Pachydermites diederixi, Proxapertites cursus, Verrutricolporites rotundiporus, Striatopollis catatumbus, Retistephanocolpites gracilis, Echiperiporites estalae, Echiperiporites sp. and Inaperturopollenites sp. The retrieved spores included Magnastriatites howardi, Acrostichum aureum, Laevigatosporites sp., Polypodiaceoisporites sp., Verrucatosporites sp., Crassoretitriletes vanraadshooveni and Stereisporites sp. The recorded dinoflagellates included Achomosphaera sp., Andalusiella sp., Polysphaeridium zoharyi, Selenopemphix nephroides and Spiniferites sp. Leiosphaeridia sp. was the only acritarch present in the assemblage. The freshwater algae was Botryococcus braunii. Fungi spore was present but not in significant amo

关键词： Niger delta Paleoclimate Paleoenvironment Miocene

Paleogeomorphic Influence on Facies Characteristics of Braided delta and Reservoir Prediction—An Example from L oilfield in Bohai Bay Basin

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Journal of Geoscience and Environment Protection 2019年第8期7卷 195-205页

作者： Longtao Cui Xinwu Liao Liye Zhou Cheng Guo Lan Zhang Tianjin Branch of CNOOC Ltd. Tianjin China

Five wells of L oilfield in Bohai bay basin have drilled 10 - 15 meters thick oil layer in the Paleogene delta. Due to the deep-buried reservoir and the poor seismic performance, it is difficult to identify the reservoir genesis, and predict reservoir distribution. By analyzing core, well logging and seismic data, a stable mudstone section is selected as the correlation marker to establish a stratigraphic framework. The paleogeomorphology is reconstructed after decompaction correction and paleobathymetric analysis. Based on the differences of paleotopography and sedimentary facies, the study area mainly develops two delta systems: low gradient coarse-grain delta system and steep gradient delta-turbidite system. The favorable reservoir of low gradient coarse-grain delta, which is thick and has good lateral connectivity, mainly locates in the delta front. The favorable reservoir of steep gradient delta-turbidite system locates in the delta front and turbidite facies, and the delta front deposits are thin and have poor lateral connectivity. The boundary of delta front is first depicted on the basis of paleotopography. In combination with reservoir architecture and forward modeling analysis, the seismic attribute is then optimized to predict the distribution of favorable reservoir. Using this method, several sets of oil-bearing sandbodies have been drilled in L oilfield, and the prediction accuracy of reservoir distribution is proved to be high. This study demonstrates that the paleogeomorphology plays an important role in controlling the genesis and distribution of the delta reservoir and provides reference for the reservoir prediction in similar oilfields.

关键词： Slope Zone Braided delta Reservoir Prediction Forward Modeling

Web GIS Solution for Monitoring the Forest-Cover in the Mekong delta, Vietnam

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Journal of Geographic Information System 2018年第5期10卷 491-502页

作者： Le Van Trung Dao Minh Tam Geomatics Center Vietnam National University Ho Chi Minh City Vietnam Ho Chi Minh City University of Technology Vietnam National University Ho Chi Minh City Vietnam

In recent years, Web GIS has been widely applied in mapping and sharing spatial data. This paper introduces a Web GIS solution has been applied to establishing “The Mekong delta Geographic Information Systems—MGIS”. The development and implementation of a web-based MGIS are a suitable technology for monitoring and managing the natural resources and environment that aims to achieve sustainable development in the Mekong delta region. The proposed solution shows that Web GIS can be applied effective to for integrating and sharing data among administration agencies in order to provide fully integrated information of updated on the status of land cover changes and analyzing the trend of forest-cover changes in this region. Results of this study illustrate the MGIS’s applications in sharing of regional data that allows multiple users to use tools for displaying spatial distribution of forest-cover in the period from the year 1990 to 2015 and analyzing the trend of changes.

关键词： Geographic Information System Web-Based GIS Forest-Cover Change MGIS Mekong delta

Mechanism of Generation and Collapse of a Longitudinal Vortex System Induced around the Leading Edge of a delta Wing

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Open Journal of Fluid Dynamics 2015年第3期5卷 265-274页

作者： Shigeru Ogawa Jumpei Takeda Department of Mechanical Engineering National Institute of Technology Kure College Hiroshima Japan

The purpose of the paper is to clarify the mechanism of generation and collapse of a longitudinal vortex system induced around the leading edge of a delta wing. CFD captured well characteristics of flow structure of the vortex system. It is found that the vortex system has a cone-shaped configuration, and both rotational velocity and vorticity have their largest values at the tip of the vortex and reduce downstream along the vortical axis. This resulted in inducing the largest negative pressure at the tip of the delta wing surface. The collapse of the vortex system was also studied. The system can still remain until the tip angle of 110 degrees. However, between 110 degrees and 120 degrees, the system becomes unstable. Over 120 degrees, the characteristics of the vortex are considered to have converted from the longitudinal vortex to the transverse one.

关键词： delta Wing Longitudinal Vortex Vortex Breakdown CFD

Seroprevalence of <i>Helicobacter pylori</i>Infection and Risk Factors among Asymptomatic Subjects in delta State, Nigeria

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Advances in Microbiology 2017年第9期7卷 641-652页

作者： Kingsley Ifeanyichukwu Omosor Omasan Herrienta Omosor Isaiah Nnana Ibeh Babatunde Ishola Gabriel Adejumo Usman Itakure Abdulkadir Uchechukwu Dimkpa Gregory Ashimedua Uchuno Ojo Moses Oke Ramatu Lawal Abdulkadir Musa Vaima Hamidu Alaba Michael Emmanuel Shalom Diagnostic Medical Laboratory Warri Nigeria Medical Laboratory Science Department University of Benin Benin City Nigeria Department of Medical Laboratory Science College of Health Sciences and Technology Markafi Nigeria Physiology Department Nnewi Campus Nnamdi Azikiwe University Awka Nigeria External Quality Assurance Department Medical Laboratory Science Council of Nigeria Abuja Nigeria Department of Medical Laboratory Science College of Health Sciences and Technology Akure Nigeria Pathology Laboratory 44 Nigerian Army Reference Hospital Kaduna Nigeria Department of Medical Laboratory Science College of Health Sciences and Technology Maiduguri Nigeria Medical Laboratory Science Department College of Health Sciences and Technology Idah Nigeria

Aim: The study aimed at evaluating the seroprevalence of H. pylori infection and its associated risk factors in a cross-section of asymptomatic adult population in Niger-delta, Nigeria. Methodology: 408 apparently healthy volunteers, aged between 18 - 87 years were recruited for this study. Blood samples were collected from participants and analyzed for H. pylori antibody (IgG) qualitatively with Combo rapid kits and quantitatively with Accu-Bind ELISA Kits. Results: The overall prevalence of Helicobacter pylori colonization in 408 asymptomatic adults was 52.5% (n = 214) and 48.3% (n = 197) by qualitative (Combo rapid kits) and quantitative (Accu-Bind ELISA Kits) serological test methods respectively. H. pylori infection did not differ statistically between genders (p = 0.962) and among age groups (p = 0.185). In addition, multivariate logistic regression indicated that sex and age were not associated with risk of H. pylori. However, participants from delta Central were at greater risk (OR = 1.89;p = 0.014) of H. pylori infection compared with those from delta South, but those from delta North were not at greater risk of infection compared with those from delta South (p = 0.476). Conclusion: This study indicated an intermediate seroprevalence of H. pylori among asymptomatic adults in delta state, Nigeria. The prevalence of H. pylori infection was linked to geographical regions but not with sex and age.

关键词： Helicobacter pylori Infection Risk Factors delta State Nigeria

New Synchronization Algorithm Based on delta Synchronization for Compressed Files in the Mobile Cloud Environment

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International Journal of Communications, Network and System Sciences 2017年第4期10卷 59-74页

作者： Rizik M. H. Al-Sayyed Feras F. Namous AlMonther H. Alkhalafat Bashar Al-Shboul Samar Al-Saqqa Department of Business Information Technology King Abdulla II School for Information Technology The University of Jordan Amman Jordan

The fast growing market of mobile device adoption and cloud computing has led to exploitation of mobile devices utilizing cloud services. One major chal-lenge facing the usage of mobile devices in the cloud environment is mobile synchronization to the cloud, e.g., synchronizing contacts, text messages, imag-es, and videos. Owing to the expected high volume of traffic and high time complexity required for synchronization, an appropriate synchronization algo-rithm needs to be developed. delta synchronization is one method of synchro-nizing compressed files that requires uploading the whole file, even when no changes were made or if it was only partially changed. In the present study, we proposed an algorithm, based on delta synchronization, to solve the problem of synchronizing compressed files under various forms of modification (e.g., not modified, partially modified, or completely modified). To measure the effi-ciency of our proposed algorithm, we compared it to the Dropbox application algorithm. The results demonstrated that our algorithm outperformed the regular Dropbox synchronization mechanism by reducing the synchronization time, cost, and traffic load between clients and the cloud service provider.

关键词： Mobile Cloud Computing delta Synchronization Compressed Files Dropbox

Heavy Minerals and Geochemical Characteristics of Sandstones as Indices of Provenance and Source Area Tectonics of the Ogwashi-Asaba Formation, Niger delta Basin

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Open Journal of Geology 2015年第8期5卷 562-576页

作者： O. Innocent Ejeh I. Anthony Akpoborie A. A. Israel Etobro Department of Geology Delta State University Abraka Nigeria

Heavy mineral petrographic and geochemical compositions (major and trace/rare earth elements)?of sandstones obtained from the Oligocene-Miocene Ogwashi-Asaba Formation, Niger delta were studied to determine their provenance, source area weathering conditions and tectonic setting. The heavy mineral suite (opaque minerals, zircon, tourmaline, and rutile) revealed that the sandstones are mineralogically mature and implied rapid disintegration and chemical decomposition of sediments mostly of recycled orogen. The sandstones were geochemically classified as Fe-sand and partly quartz arenitic. Chemical Index of Alteration and Chemical Index of Weathering values of 89.92% and 91.87% respectively suggest that the source region was predominantly felsic and was subjected to intense chemical weathering probably under tropical palaeoclimatic conditions with abundant rainfall that enhanced sediment recycling. Major element concentration discriminant plots also indicated that the sediments were derived from mixed sources (granitic, gneissic or recycled orogen) under passive margin setting. Chondrite normalized plot of the rare earth element pattern is marked by light rare earth element enrichment and negative Eu anomalies, interpreted to mean that provenance was mainly continental crustal rocks. Trace elemental ratios that are provenance diagnostic (La/Sc, Th/Sc, Cr/Th, La/Co, Th/Co, Th/Cr, Eu/Eu*, and Eu*) all point to sediments derived from felsic source and upper continental crust. The mixed provenance of the sandstones can be traced to the southwestern and southeastern Basement Complex (consisting of granites, gneisses, etc.) and sediments derived from the adjacent sedimentary basins (Anambra and Benue Trough).

关键词： Provenance Source Area Tectonics Heavy Minerals Geochemical Characteristics Sandstones Ogwashi-Asaba Formation Niger delta Basin

THE FLOOD DISASTER AND MITIGATION PROJECTION IN YANGTZE delta AREA

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Natural Disaster Reduction in China 1994年第3期 131-136页

作者：孙顺才黄新

ＴＨＥＦＬＯＯＤＤＩＳＡＳＴＥＲＡＮＤＭＩＴＩＧＡＴＩＯＮＰＲＯＪＥＣＴＩＯＮＩＮＹＡＮＧＴＺＥＤＥＬＴＡＡＲＥＡＳｕｎＳｈｕｎｃａｉ（孙顺才）ａｎｄＨｕａｎｇＸｉｎ（黄新）（ＮａｎｊｉｎｇＩｎｓｔｉｔｕｔｅｏｆＧｅ... 详细信息

ＴＨＥＦＬＯＯＤＤＩＳＡＳＴＥＲＡＮＤＭＩＴＩＧＡＴＩＯＮＰＲＯＪＥＣＴＩＯＮＩＮＹＡＮＧＴＺＥＤＥＬＴＡＡＲＥＡＳｕｎＳｈｕｎｃａｉ（孙顺才）ａｎｄＨｕａｎｇＸｉｎ（黄新）（ＮａｎｊｉｎｇＩｎｓｔｉｔｕｔｅｏｆＧｅｏｇｒａｐｈｙａｎｄＬｉｍｎｏｌｏ...

关键词： delta