Investigation of Pollution Level of Traces Metals Elements in Agricultural Soil of Oubritenga Province of Burkina Faso

The purpose of this study was to investigate the pollution level of trace metals As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, Sb, Se and Zn in agricultural soil around the water reservoir. A total of 36 soil samples were collected both during off-season agriculture and pluvial agriculture from April to October 2022. The samples were analyzed for trace metals according to the standard methods of the US EPA 2007 with a microwave plasma atomic emission spectrometer (MP-AES), Agilent Model 4210. The pollution level was assessed using contamination factor (Cf) and modified contamination degree (mCd). During the off-season, the concentration of trace metals followed in descending order as Mn > Cr > Cu > Pb > Zn. As, Cd, Co, Hg, Ni, Sb and Se were below the detectable limits. In pluvial season, the concentration of traces of metal follows the order Mn > Cr > Zn > Cu > Ni > Pb > Hg > As. Cd, Co, Sb and Se remain below the detectable limits. The concentrations of Cr, Mn and Zn were lower in the off-season agriculture than in pluvial agriculture. For Cu and Pb, the concentrations were higher in the off-season than in pluvial agriculture. The Cf ranges from 0.24 to 11.70 depending on the considered trace metal. The Cf values of As, Ni, Pb, Zn and Mn indicated that the agricultural study soil was lowery contaminated by these trace metals. The agricultural study soil was moderately contaminated by Cr and Cu, and highly contaminated by Hg. Globally the agricultural study soil presents a moderate degree of contamination (mCd 2.25) by the eight trace metals studied. This result provides information on understanding the risks of trace metal contamination of agricultural soil. It is important to anticipate the control of soil contamination through regular monitoring of toxic metals in agricultural soils, control the quality of chemicals used in agriculture and regulate their use.

Evaluation of Total Hydrocarbons Levels and Traces Metals in Water and Sediment from Main Outfall Drain in Al-Nassiriya City/Southern Iraq

This study was conducted during Dec2011-Nov2012 on three stations located in the south sector of Main Outfall Drain (MOD) River. Station 1 was near Al-Holandee Bridge which was the general carriage way in the center of Al-Nassiriya city, station 2 was 20 km far from the first station, while station 3 was in the beginning of the new branch. This study reveals the Seasonal Variation of Total petroleum hydrocarbons (TPHs) in both surface waters, sediment and it is related with trace metals nickel and vanadium in water (dissolved, particulate) and sediment (residual and exchangeable) phases. Also, the study shows the relationships between the concentration of Ni and V with Total Organic Carbon (TOC%) in the sediment.

Potential traces of earthquakes in the ancient city of Kytaia, Kerch Peninsula, Crimea

In this paper, the authors studied the traces of destruction in the fortress walls and houses of the Bosporan city of Kytaia. The study of this city has been ongoing since 1970. Over the past time, numerous damages have been identified at different sites of the ancient settlement. In the article, an attempt is made to compare some of them with the results of earthquakes on the Bosporus, about which the data of ancient authors were preserved.

New Analytical Methodology for Sb(III) Traces Quantification as Emergent Contaminant in Drinks Packaged PET Samples by Solid Surface Fluorescence

Emerging contaminants constitute a set of substances that are released into the environment for which regulations are currently not established for their environmental monitoring, being antimony one of them. A new methodology for Sb(III) traces monitoring by solid surface fluorescence is proposed. The metal was complexed with alizarine (Az) as fluorosphore reagent in alcaline medium in presence of the bile salt sodium cholate. To isolate the analyte of matrix constituents, a preconcentration/separation strategy on filter paper was introduced prior to determination step. The solid surface fluorescence was measured λem = 450 nm and λexc = 363 nm using a solid sampler holder. Under optimal conditions, the limits of detection and quantification of proposed methodology were 0.08 and 0.24 μg·L-1, respectively, showing a linear range from 0.24 to 304.4 μg·L-1 with good sensitivity and adequate selectivity. It was applied to the Sb(III) traces determination present in drinking water and beverages samples packaged in polyethylene terephthalate (PET) bottles widely consumed in Argentina. The combination of a preconcentration step on common filter paper and the inherent sensitivity of photoluminescent methods have permitted to achieve sensitivity similar to atomic spectroscopies using a lower price instrument typical in control laboratories. Precision and accuracy were tested with excellent agreement. Results were truenessed by ETAAS with satisfactory concordance.

Surfactant Enhanced Chemofiltration of Zinc Traces Previous to Their Determination by Solid Surphase Fluorescence

Surfactant enhanced chemofiltration on Nylon membranes pre-treated with hexadecyltrimethylammonium bromide (HTAB) and eosin dye (eo) is proposed for zinc traces quantification by solid surphase spectro- fluorimetry (SSF, λexc = 532 nm;λem = 548 nm). Operational variables which have influence on quantitative retention of metal complex have been studied and optimized. At optimal experimental conditions, quantita- tive recovery was reached with a detection limit of 0.662 pg?L–1 and quantification limit of 2.20 pg?L–1. The calibration sensitivity was of 1.22 L?pg–1 for the new methodology with a linear range of 2.20 pg?L–1 to 779 pg?L–1 Zn (II). The tolerance levels of potential interfering ions were studied with good results. Recuperation studies were carried out by standard addition method applied to natural water samples (San Juan, Argentine) without previous treatment. The reproducibility (between-days precision) was also evaluated over 3 days by performing five determinations each day. CV% was 0.37. The performing obtained in sensitivity and selec- tivity thanks to chemofiltration step, converts the proposed methodology in an adequate alternative to con- ventional techniques for Zn (II) traces determination.

Determination of Uranium Traces in Nuclear Reactor IEA-R1 Pool Water

IEA-R1 nuclear reactor operation has the routine to control uranium content in pool water to be in trace range below 50 μg/L. There are several routes to determine the uranium trace content in water in the literature;voltammetry has been systematically employed. In the present study, the chosen chemical determination of uranium traces used the voltammetric method known as AdCSV (adsorptive cathodic stripping voltammetry). This technique, based on mercury voltammetry, is an adequate methodology to determine uranium traces. The chloranilic acid [CAA] (2,5-dichloro-3,6-dihydroxy-1,4-benzo-quinone) is indicated as chelating agent. The redox reaction of UO2+2?with CAA is sensitive in the range of 2 2(CAA)2] reduction potential. In this work, we present the uranium trace results for IEA-R1 reactor water, sampled after an operation routine shutdown. The uranium trace determination for IEA-R1 pool water showed content around 1 μg/L [U] with statistical significance. Therefore the IEA-R1-reactor-water purification showed to be adequate and safe.

Green Photoluminescent Methodology for Aluminium Traces Quantification in 24-Hour Urine of Subjects with Different Exposition to Tobacco Smoke

The aim of this work has been to evaluate the aluminium (Al(III)) traces contents in 24-hour urine samples from subjects with different tobacco smoke expositions using a new methodology with 1,4-dihydroxy-9, 10-anthraquinone (Quinizarine, QZ) as a fluorosphore. Biological samples were tested using commercial reagent strips and clinical parameters. Al(III) was determined complexing with QZ followed by a solid phase extraction step using Nylon membranes as a solid support. The analyte was subsequently quantified by solid surface fluorescence (SSF, λem= 573, λexc= 490) with a detection limit of 0.88 μg L-1 and quantification limit of 2.69 μg L-1. The calibration curve was linear from 2.69 to 499.13 μg L-1 Al(III) (R2 = 0.9973). Urine samples were successfully analysed with an average recovery close to 100%. Solid phase extraction step showed efficacy to eliminate foreign ions and the highly fluorescent matrix own of urine. Results were validated by electrothermal atomic absorption spectrometry (ETAAS) with an adequate concordance. The new methodology has low operation cost with simple instrumentation and without organic solvent.

Behavioral Diversity and Complexity Indicated by Metazoan Traces at a Topological Level since Proterozoic

On the basis of topological criteria, metazoan traces can be classified as four ichnoorders (clusters) and twenty two ichnofamilies (kinds), which consist of nine basic and three combined topological configurations. At a topological level, the behavioral diversity and complexity indicated by metazoan traces have remained quite stable since the Early Cambrian. Dramatic changes of these traits took place in the Neoproterozoic, in which 75% (12/16) of the topoichnotaxa and all nine basic topological configurations of metazoan traces occurred, but the most complex and highest level topological configuration occurred in the Early Cambrian of the coelomate animal explosive evolution, showing that in the Neoproterozoic and Early Cambrian gestated not only the Ediacarian fauna and all the basic types of multi cellular animals known today, but also all the basic and the most complex metazoan traces through geological time.

Borderline Case of Traces and Extensions for Weighted Sobolev Spaces

In this paper,we study the traces and the extensions for weighted Sobolev spaces on upper half spaces when the weights reach to the borderline cases.We first give a full characterization of the existence of trace spaces for these weighted Sobolev spaces,and then study the trace parts and the extension parts between the weighted Sobolev spaces and a new kind of Besov-type spaces(on hyperplanes)which are defined by using integral averages over selected layers of dyadic cubes.

筛泡径路黏膜间隙追踪法在鼻内镜额窦开放术中的应用

目的应用黏膜延续性的特点,探讨黏膜间隙追踪法在临床中的应用。方法回顾性分析2021年1月~2023年1月间32例行黏膜间隙追踪法额窦开放术患者的临床资料,分析和记录术中情况以及随访观察恢复情况。结果黏膜间隙追踪法额窦开放手术时间短,手术并发症少。术后随访6个月以上,临床症状逐步消失,病变未复发。结论黏膜间隙追踪法可以将复杂关系的额隐窝手术简单化,提高手术安全性和手术效率。

Cauchy problem and initial traces for a doubly nonlinear degenerate parabolic equation

The Cauchy problem and initial traces for the doubly degenerate parabolic equationsare studied. Under certain growth condition on the initial datum u0(x) as the existence of solution is proved. The results obtained are optimal in the dass of nonnegative locally bounded solution, for which a Harnack-type inequality holds.

Fault monitoring in passive optical network using code division multiplex-based dual-OTDR traces comparison

A dual optical time domain reflectometry(OTDR)system,which employs two different continuous waves at the optical line terminal and a pair of fiber Bragg gratings at the end of each optical network unit,is proposed in a time-division multiplexing passive optical network(PON).The proposed scheme accomplishes the fiber fault monitoring by comparing the different wavelength’s testing curves.Complete complementary code is utilized to measure multiple wavelength signals simultaneously with only one receiver and to improve the dynamic range of this system.The PON system consisting of 20 km feeding fiber and a 1:16 splitter is investigated by the experiments.The experimental results show that the faulty branch can be successfully identified by using our scheme.What is more,we also demonstrate that our scheme can be applied to the multi-stage PON.

Trace elements in magmatic and hydrothermal quartz:Implications on the genesis of the Xingluokeng Tungsten Deposit,South China

The Xingluokeng deposit is the largest gran-ite-related tungsten deposit within the Wuyi metallogenic belt in South China.The Xingluokeng intrusion primarily consists of porphyritic biotite granite,biotite granite,andfine-grained granite.The deposit is represented by veinlet-disseminated mineralization with K-feldspathization and biotitization,alongside quartz-vein mineralization with gre-isenization and sericitization.This study investigates in-situ analyses of quartz compositions from both the intrusion and hydrothermal veinlets and veins.Trace element correlations indicate that trivalent Al^(3+)and Fe^(3+)replace Si^(4+)within the quartz lattice,with monovalent cations(such as Li^(+),Na^(+),and K^(+))primarily serving as charge compensators.Low Ge/Al ratios(<0.013)of quartz from granites suggest a mag-matic origin.The low Al/Ti and Ge/Ti ratios,accompanied by high Ti contents in quartz,suggest that the porphyritic biotite granite and biotite granite are characterized by rela-tively low levels of differentiation and high crystallization temperatures.In contrast,thefine-grained granite exhibits a higher degree of fractionation,lower crystallization tem-peratures,and a closer association with tungsten miner-alization.Ti contents in quartz from quartz veins indicate Qz-Ⅰformed at temperatures above 400°C,while Qz-Ⅱto Qz-Ⅴformed at temperatures below 350°C.Variations in different generations of quartz,as indicated by Al content and(Al+Fe)/(Li+Na+K)ratio,suggest that Qz-Ⅰprecipi-tated from a less acidicfluid with a stable pH,whereas Qz-Ⅱto Qz-Ⅴoriginated from a more acidicfluid with notable pH variations.Consequently,alkaline alteration and acidic alteration supplied the essential Ca and Fe for the precipita-tion of scheelite and wolframite,respectively,highlighting a critical mechanism in tungsten mineralization at the Xin-gluokeng deposit.

Distribution, health and ecological risk assessments of trace elements in Nigerian oil sands

The Nigerian oil sands represent the largest oil sand deposit in Africa, yet there is little published information on the distribution and potential health and ecological risks of trace elements in the oil resource. In the present study, we investigated the distribution pattern of 18trace elements(including biophile and chalcophile elements) as well as the estimated risks associated with exposure to these elements. The results of the study indicated that Fe was the most abundant element, with a mean concentration of 22,131 mg/kg while Br had the lowest mean concentration of 48 mg/kg. The high occurrence of Fe and Ti suggested a possible occurrence of ilmenite(Fe TiO_(3)) in the oil sands. Source apportionment using positive matrix factorization showed that the possible sources of detected elements in the oil sands were geogenic, metal production, and crustal. The contamination factor, geo-accumulation index, modified degree of contamination, pollution load index, and Nemerow pollution index indicated that the oil sands are heavily polluted by the elements. Health risk assessment showed that children were relatively more susceptible to the potentially toxic elements in the oil sands principally via ingestion exposure route(HQ > 1E-04). Cancer risks from inhalation are unlikely due to CR < 1E-06 but ingestion and dermal contact pose severe risks(CR > 1E-04). The high concentrations of the elements pose serious threats due to the potential for atmospheric transport, bioaccessibility, and bioavailability.

Paleoenvironmental Characteristics of Paleogene Lacustrine Source Rocks in the Western Bozhong Sag,Bohai Bay Basin,China:Evidence from Biomarkers,Major and Trace Elements

The organic matter(OM)enrichment mechanisms and depositional environment characteristics of lacustrine source rocks in the western Bozhong Sag,Bohai Bay Basin in Northeast China remain controversial.To address these issues,based on Rock-Eval pyrolysis,kerogen macerals,H/C and O/C ratios,GC-MS,major and trace elements,the Dongying Formation Member(Mbr)3(E_(3)d_(3)),the Shahejie Formation mbrs 1 and 2(E_(2)s_(1+2)),and the Shahejie Mbr 3(E_(2)s_(3))source rocks in the western Bozhong Sag were studied.The above methods were used to reveal their geochemical properties,OM origins and depositional environments,all of which indicate that E_(2)s_(1+2)and E_(2)s_(3)are excellent source rocks,and that E_(3)d_(3)is of the second good quality.E_(3)d_(3)source rocks were formed under a warm and humid climate,mainly belong to fluvial/delta facies,the E_(3)d_(3)sediments formed under weakly oxidizing and freshwater conditions.Comparatively,the depositional environments of E_(2)s_(1+2)source rocks were arid and cold climate,representing saline or freshwater lacustrine facies,and the sediments of E_(2)s_(1+2)belong to anoxic or suboxic settings with large evaporation and salinity.During the period of E_(2)s_(3),the climate became warm and humid,indicating the freshwater lacustrine facies,and E_(2)s_(3)was characterized by freshwater and abundant algae.Moreover,compared with other intervals,the OM origin of E_(3)d_(3)source rocks has noticeable terrestrial input.The OM origin of the E_(2)s_(1+2)and E_(2)s_(3)are mainly plankton and bacteria.Tectonic subsidence and climate change have affected the changes of the depositional environment in the western Bozhong Sag,thus controlling the distribution of the source rocks,the geochemical characteristics in the three intervals of lacustrine source rocks have distinct differences.Overall,these factors are effective to evaluate the paleoenvironmental characteristics of source rocks by biomarkers,major and trace elements.The established models may have positive implications for research of lacustrine source rocks in offshore areas with few drillings.

Weathering and accumulation of trace elements in the soils of the Porali Plain, Balochistan: repercussions in agriculture

This study is thefirst attempt to assess the nature of the soil,especially on the western side of the Porali Plain in Balochistan;a new emerging agriculture hub,using weathering and pollution indices supplemented by multi-variate analysis based on geochemical data.The outcomes of this study are expected to help farmers in soil manage-ment and selecting suitable crops for the region.Twenty-five soil samples were collected,mainly from the arable land of the Porali Plain.After drying and coning-quarter-ing,soil samples were analyzed for major and trace ele-ments using the XRF technique;sieving and hydrometric methods were employed for granulometric analysis.Esti-mated data were analyzed using Excel,SPSS,and Surfer software to calculate various indices,correlation matrix,and spatial distribution.The granulometric analysis showed that 76%of the samples belonged to loam types of soil,12%to sand type,and 8%to silt type.Weathering indices:CIA,CIW,PIA,PWI,WIP,CIX,and ICV were calculated to infer the level of alteration.These indices reflect mod-erate to intense weathering;supported by K_(2)O/AI_(2)O_(3),Rb/K_(2)O,Rb/Ti,and Rb/Sr ratios.Assessment of the geo-ac-cumulation and Nemerow Pollution indices pinpoint rela-tively high concentrations of Pb,Ni,and Cr concentration in the soils.The correlation matrix and Principal Compo-nent Analysis show that the soil in this study area is mainly derived from the weathering of igneous rocks of Bela Ophiolite(Cretaceous age)and Jurassic sedimentary rocks of Mor Range having SEDEX/MVT type mineralization.Weathering may result in the undesirable accumulation of certain trace elements which adversely affects crops.

Periodic signal extraction of GNSS height time series based on adaptive singular spectrum analysis

Singular spectrum analysis is widely used in geodetic time series analysis.However,when extracting time-varying periodic signals from a large number of Global Navigation Satellite System(GNSS)time series,the selection of appropriate embedding window size and principal components makes this method cumbersome and inefficient.To improve the efficiency and accuracy of singular spectrum analysis,this paper proposes an adaptive singular spectrum analysis method by combining spectrum analysis with a new trace matrix.The running time and correlation analysis indicate that the proposed method can adaptively set the embedding window size to extract the time-varying periodic signals from GNSS time series,and the extraction efficiency of a single time series is six times that of singular spectrum analysis.The method is also accurate and more suitable for time-varying periodic signal analysis of global GNSS sites.

The viscous strip approach to simplify the calculation of the surface acoustic wave generated streaming

In recent decades,the importance of surface acoustic waves,as a biocompatible tool to integrate with microfluidics,has been proven in various medical and biological applications.The numerical modeling of acoustic streaming caused by surface acoustic waves in microchannels requires the effect of viscosity to be considered in the equations which complicates the solution.In this paper,it is shown that the major contribution of viscosity and the horizontal component of actuation is concentrated in a narrow region alongside the actuation boundary.Since the inviscid equations are considerably easier to solve,a division into the viscous and inviscid domains would alleviate the computational load significantly.The particles'traces calculated by this approximation are excellently alongside their counterparts from the completely viscous model.It is also shown that the optimum thickness for the viscous strip is about 9-fold the acoustic boundary layer thickness for various flow patterns and amplitudes of actuation.

Trace element compositions of pyrite and stibnite:implications for the genesis of antimony mineralization in the Yangla Cu skarn deposit,Northwestern Yunnan,China

The Yangla Cu skarn deposit is located in the central part of the Jinshajiang Suture Zone,southwest China,with a total reserve of 150 Mt Cu@1.03%.The newly discovered antimony orebodies at the depth of Yangla are strictly controlled by the stratum,structure,and lithology,which are lenticular and vein-like within the marble fracture zone,which can provide a window into multistage miner-alization and ore genesis at Yangla.Mineralization can be divided into three types,Cu–Pb–Zn(skarn)pyrite,galena,and sphalerite,Cu(porphyry)chalcopyrite and pyrite,and Sb(hydrothermal)stibnite and pyrite.The mineral assem-blages were stibnite+pyrite+calcite+quartz±minor scheelite in antimony ores.This study presents quantitative measurements of the trace element compositions of pyrite and stibnite from the Yangla antimony ores.Analysis of pyrite with electron probe microanalysis(EPMA)showed enrichment in Co,Ni,Sb,As,and Mo,and deficit in its S and Fe contents when compared to the stoichiometric con-centrations of S and Fe in pyrite.The Sb-related pyrite may belong to sedimentary-reworked genesis and may be modi-fied by hydrothermalfluids,thereby presenting a certain dif-ference(i.e.,crystal morphology,texture,and chemical com-position)compared to the skarn and porphyry Cu-related pyrite in the Yangla Cu skarn deposit.Analysis of stibnite with EPMA and inductively coupled plasma-mass spectrom-etry showed enrichment in As,Pb,Sn,Pb,Cu,and Zn,and presented much higher Sb contents and slightly lower S con-tents when compared to the stoichiometric concentrations of Sb and S in stibnite.Statistical analysis of the stibnite trace elements showed correlations for the elemental pairs Cu–Pb,As–Sb,and Sn–Pb,and the coupled substitution equations Sb^(3+)↔Cu^(+)+Pb^(2+),Sb^(3+)↔As^(3+),and Sn^(2+)↔Pb^(2+)may be the major factors governed the incorporating Cu,Pb,As and Sn within the stibnite.Moreover,this study preliminary shows that the antimony mineralization may belong to a car-bonate replacement hydrothermal genesis at Yangla.

Visualizing Wallerian degeneration in the corticospinal tract after sensorimotor cortex ischemia in mice

Stroke can cause Wallerian degeneration in regions outside of the brain,particularly in the corticospinal tract.To investigate the fate of major glial cells and axons within affected areas of the corticospinal tract following stroke,we induced photochemical infarction of the sensorimotor cortex leading to Wallerian degeneration along the full extent of the corticospinal tract.We first used a routine,sensitive marker of axonal injury,amyloid precursor protein,to examine Wallerian degeneration of the corticospinal tract.An antibody to amyloid precursor protein mapped exclusively to proximal axonal segments within the ischemic cortex,with no positive signal in distal parts of the corticospinal tract,at all time points.To improve visualization of Wallerian degeneration,we next utilized an orthograde virus that expresses green fluorescent protein to label the corticospinal tract and then quantitatively evaluated green fluorescent protein-expressing axons.Using this approach,we found that axonal degeneration began on day 3 post-stroke and was almost complete by 7 days after stroke.In addition,microglia mobilized and activated early,from day 7 after stroke,but did not maintain a phagocytic state over time.Meanwhile,astrocytes showed relatively delayed mobilization and a moderate response to Wallerian degeneration.Moreover,no anterograde degeneration of spinal anterior horn cells was observed in response to Wallerian degeneration of the corticospinal tract.In conclusion,our data provide evidence for dynamic,pathogenic spatiotemporal changes in major cellular components of the corticospinal tract during Wallerian degeneration.