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Uptake of U-and Th-series radionuclides by cereal crops in Upper Egypt

Nuclear Science and Techniques 2009年第2期20卷 99-105页

作者： SHABAN Harb rolf michel Center for Radiation Protection and Radioecology Hanover University(ZSR) Physics Department Faculty of ScienceSouth Valley University

The main aim of this study is to determine the activity concentrations of uranium series and thorium series radionuclide in crops cultivated in Upper *** types of cereal crops were collected from local markets and analyzed by γ-ray *** mean activity concentrations of the natural radionuclides 238U,226Ra and 232Th were 0.67,1.27 and 0.56 Bq·kg-1,*** annual effective doses from these radionuclides were estimated for different age groups.

关键词：天然放射性核素谷类作物埃及 U型吸收 226Ra 作物栽培有效剂量

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Measurements of natural radionuclides in soil samples from Upper Egypt

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Nuclear Science and Techniques 2008年第5期19卷 302-307页

作者： Shaban Ramadan Mohamed HARB Khaled SALAHEL DIN Abd Elbaset ABBADY Mohamed Abd Elleh ALI rolf michel Physics Department Faculty of ScienceSouth Valley University Center for Radiation Protection and Radioecology Hanover University (ZSR)

This paper presents the results of natural radioactivity measured for the soil of Qena using gamma-ray spectrometry at ZSR,Hanover University,*** samples of radioactive concentrations of ^(238)U-series (^(234)Th, ^(214)pb,and^(214)Bi),^(232)Th-series (^(228)Ac,^(212)pb,and ^(208)T1) and ^(40)K were *** objectives were set:(1) activity levels by surface soil sampling at 0～30 cm depth,(2) dose rates of gamma radiation,radium equivalent,index hazard, and effective dose,and (3) ambient dose rates.

关键词：土壤环境放射能 γ光谱测定法辐射暴露环境剂量

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Multivariate Approach to Characterizing Soil Quality of Gabonese’s Ferralitic Soils

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Open Journal of Soil Science 2024年第4期14卷 237-268页

作者： Neil-Yohan Musadji rolf Gaël Mabicka Obame michel Mbina Mounguengui Jean Aubin Ondo Lydie-Stella Koutika Eric Ravire Claude Geffroy Laboratoire De Chimie Des Milieux et Des Mat&#233riaux Inorganiques Laboratoire D&#8217Analyse Des Sols et Environnement D&#233partement Des Sciences Fondamentales De L&#8217Ing&#233nieur Institut National D&#8217Agronomie et De Biotechnologies Universit&#233 Des Sciences et Techniques De Masuku Franceville Gabon Institut De Chimie Des Milieux et Maté riaux De Poitiers (IC2MP) Universit&#233 De Poitiers Poitiers France Laboratoire De Chimie Des Milieux et Des Mat&#233riaux Inorganiques Laboratoire D&#8217Analyse Des Sols et Environnement D&#233partement De Phytotechnologie Institut National D&#8217Agronomie et De Biotechnologies Universit&#233 Des Sciences et Techniques De Masuku Franceville Gabon Dé partement De G&#233ologie Facult&#233 Des Sciences Universit&#233 Des Sciences et Techniques De Masuku Franceville Gabon Laboratoire Pluridisciplinaire Des Sciences Ecole Normale Sup&#233rieure Libreville Gabon Centre De Recherche Sur La Productivité et La Durabilit&#233 Des Plantations Industrielles Pointe Noire Republic of Congo Sucaf Gabon Somdiaa Franceville Gabon

Assessing soil quality is essential for crop management and soil temporal changes. The present study aims to evaluate soil quality in the Ferralitic soils context countrywide. This assessment was done using multivariate soil quality indice (SQI) models, such as additive quality index (AQI), weighted quality indexes (WQIadd and WQIcom) and Nemoro quality index (NQI), applied to two approaches of indicator selection: total data set (TDS) and minimum data set (MDS). Physical and chemical soil indicators were extracted from the ORSTOM’s reports resulting from a sampling campaign in different provinces of Gabon. The TDS approach shows soil quality status according to eleven soil indicators extracted from the analysis of 1,059 samples from arable soil layer (0 - 30 cm depth). The results indicated that 87% of all provinces presented a very low soil quality (Q5) whatever the model. Among soil indicators, exchangeable K+ and Mg2+, bulk density and C/N ratio were retained in MDS, using principal component analysis (PCA). In the MDS approach, 50 to 63% of provinces had low soil quality grades with AQI, WQIadd and NQI, whereas the total was observed with WQIcom. Only 25% of provinces had medium soil quality grades with AQI and NQI models, while 12.5% (NQI) and 25% (AQI) presented high quality grades. Robust statistical analyses confirmed the accuracy and validation (0.80 r P ≤ 0.016) of AQI, WQIadd and NQI into the TDS and MDS approaches. The same sensitivity index value (1.53) was obtained with AQI and WQIadd. However, WQIadd was chosen as the best SQI model, according to its high linear regression value (R2 = 0.82) between TDS and MDS. This study has important implications in decision-making on monitoring, evaluation and sustainable management of Gabonese soils in a pedoclimatic context unfavorable to plant growth.

关键词： Gabon Ferralitic Soil Soil Indicators Standard Score Function Soil Quality Indices Sustainable Soil Soil Management

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National Soil Organic Carbon Stocks Inventories under Different Mangrove Forest Types in Gabon

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Open Journal of Forestry 2024年第2期14卷 127-140页

作者： rolf Gaël Mabicka Obame Neil-Yohan Musadji Jean Hervé Mve Beh Lydie-Stella Koutika Jean Aubin Ondo Farrel Nzigou Boucka michel Mbina Mounguengui Claude Geffroy Dé partement de Phytotechnologie Institut National d&#8217Agronomie et de Biotechnologies Universit&#233 des Sciences et Techniques de Masuku Franceville Gabon Dé partement des Sciences Fondamentales de l&#8217Ing&#233nieur Institut National d&#8217Agronomie et de Biotechnologies Universit&#233 des Sciences et Techniques de Masuku Franceville Gabon Institut Agronomiques et Forestiè res Centre National des Recherches Scientifiques et Technologiques Libreville Gabon Research Centre on the Durability and the Productivity of Industrial Plantations (CRDPI) Pointe Noire Republic of Congo Laboratoire Pluridisciplinaire des Sciences &#201cole Normale Sup&#233rieure Libreville Gabon Agence Gabonaise d’ &#201tude et d&#8217Observation Spatiale Immeuble les Arcades Libreville Gabon Dé partement de G&#233ologie Faculte des Sciences Universit&#233 des Sciences et Techniques de Masuku Franceville Gabon Institut de Chimie des Milieux et Maté riaux de Poitiers (IC2MP) Universit&#233 de Poitiers Poitiers France

Gabonese’s estuary is an important coastal mangrove setting and soil plays a key role in mangrove carbon storage in mangrove forests. However, the spatial variation in soil organic carbon (SOC) storage remain unclear. To address this gap, determining the SOC spatial variation in Gabonese’s estuarine is essential for better understanding the global carbon cycle. The present study compared soil organic carbon between northern and southern sites in different mangrove forest, Rhizophora racemosa and Avicennia germinans. The results showed that the mean SOC stocks at 1 m depth were 256.28 ± 127.29 MgC ha−1. Among the different regions, SOC in northern zone was significantly (p p −1) than upper layers (55.42 ± 25.37 MgC ha−1). The study highlights that low deforestation rate have led to less CO2 (705.3 Mg CO2e ha−1 - 922.62 Mg CO2e ha−1) emissions than most sediment carbon-rich mangroves in the world. These results highlight the influence of soil texture and mangrove forest types on the mangrove SOC stocks. The first national comparison of soil organic carbon stocks between mangroves and upland tropical forests indicated SOC stocks were two times more in mangroves soils (51.21 ± 45.00 MgC ha−1) than primary (20.33 ± 12.7 MgC ha−1), savanna and cropland (21.71 ± 15.10 MgC ha−1). We find that mangroves in this study emit lower dioxide-carbon equivalent emissions. This study highlights the importance of national inventories of soil organic carbon and can be used as a baseline on the role of mangroves in carbon sequestration and climate change mitigation but the variation in SOC stocks indicates the need for further national data.

关键词： Mangroves Forest Soil Organic Carbon Stocks Rizophora Racemose Avicenia germinans Gabon

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High-speed identification of suspended carbon nanotubes using Raman spectroscopy and deep learning

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Microsystems & Nanoengineering 2022年第1期8卷 259-267页

作者： Jian Zhang Mickael L.Perrin Luis Barba Jan Overbeck Seoho Jung Brock Grassy Aryan Agal Rico Muff rolf Brönnimann Miroslav Haluska Cosmin Roman Christofer Hierold Martin Jaggi michel Calame Laboratory for Transport at Nanoscale Interfaces EmpaSwiss Federal Laboratories for Materials Science and TechnologyCH-8600 DübendorfSwitzerland Machine Learning and Optimization Laboratory School of Computer and Communication SciencesEPFLCH-1015 LausanneSwitzerland Department of Physics and Swiss Nanoscience Institute University of BaselCH-4056 BaselSwitzerland Micro-and Nanosystems Department of Mechanical and Process EngineeringETH ZurichCH-8092 ZurichSwitzerland

The identification of nanomaterials with the properties required for energy-efficient electronic systems is usually a tedious human task.A workflow to rapidly localize and characterize nanomaterials at the various stages of their integration into large-scale fabrication processes is essential for quality control and,ultimately,their industrial *** this work,we develop a high-throughput approach to rapidly identify suspended carbon nanotubes(CNTs)by using high-speed Raman imaging and deep learning *** for Raman spectra with extremely low signal-to-noise ratios(SNRs)of 0.9,we achieve a classification accuracy that exceeds 90%,while it reaches 98%for an SNR of *** applying a threshold on the output of the softmax layer of an optimized convolutional neural network(CNN),we further increase the accuracy of the ***,we propose an optimized Raman scanning strategy to minimize the acquisition time while simultaneously identifying the position,amount,and metallicity of CNTs on each *** approach can readily be extended to other types of nanomaterials and has the potential to be integrated into a production line to monitor the quality and properties of nanomaterials during fabrication.

关键词： carbon suspended speed

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