RESUMO
Onboard electrostatic suspension inertial sensors are important applications for gravity satellites and space gravitational-wave detection missions, and it is important to suppress noise in the measurement signal. Due to the complex coupling between the working space environment and the satellite platform, the process of noise generation is extremely complex, and traditional noise modeling and subtraction methods have certain limitations. With the development of deep learning, applying it to high-precision inertial sensors to improve the signal-to-noise ratio is a practically meaningful task. Since there is a single noise sample and unknown true value in the measured data in orbit, odd-even sub-samplers and periodic sub-samplers are designed to process general signals and periodic signals, and adds reconstruction layers consisting of fully connected layers to the model. Experimental analysis and comparison are conducted based on simulation data, GRACE-FO acceleration data, and Taiji-1 acceleration data. The results show that the deep learning method is superior to traditional data smoothing processing solutions.
Assuntos
Acelerometria , Monitoramento Ambiental , Gravitação , Modelos Teóricos , Ruído , Aceleração , Acelerometria/instrumentação , Acelerometria/métodos , Simulação por Computador , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Aprendizado Profundo , Sensação Gravitacional , Astronave/instrumentaçãoRESUMO
Upside-down jellyfish (Cassiopea sp.) are mostly sedentary, benthic jellyfish that have invaded estuarine ecosystems around the world. Monitoring the spread of this invasive jellyfish must contend with high spatial and temporal variability in abundance of individuals, especially around their invasion front. Here, we evaluated the utility of drones to survey invasive Cassiopea in a coastal lake on the east coast of Australia. To assess the efficacy of a drone-based methodology, we compared the densities and counts of Cassiopea from drone observations to conventional boat-based observations and evaluated cost and time efficiency of these methods. We showed that there was no significant difference in Cassiopea density measured by drones compared to boat-based methods along the same transects. However, abundance estimates of Cassiopea derived from scaling-up transect densities were over-inflated by 319% for drones and 178% for boats, compared to drone-based counts of the whole site. Although conventional boat-based survey techniques were cost-efficient in the short-term, we recommend doing whole-of-site counts using drones. This is because it provides a time-saving and precise technique for long-term monitoring of the spatio-temporally dynamic invasion front of Cassiopea in coastal lakes and other sheltered marine habitats with relatively clear water.
Assuntos
Comportamento Animal/fisiologia , Monitoramento Ambiental/métodos , Dispositivos Aéreos não Tripulados/ética , Animais , Animais Selvagens , Austrália , Ecossistema , Monitoramento Ambiental/economia , Monitoramento Ambiental/instrumentação , Espécies Introduzidas/tendências , Lagos , Cifozoários/metabolismo , ÁguaRESUMO
Abstract The present work reports the implementation of the Hazard Analysis Critical Control Point (HACCP) methodology to analyze the water purification system of a pharmaceutical site, in order to assure the system quality and prevent failures. As a matter of fact, the use of HACCP for development and implementation of Quality Risk Management (QRM) is not usual in pharmaceutical plants and it is applied here to improve the performance of the water purification system of a polymerization pilot plant used to manufacture pharmaceutical grade polymer microparticles. Critical Control Points (CCP) were determined with the aid of a decision tree and questions were made to characterize whether identified hazards constitute actual CCPs and should be monitored. When deviations were detected, corrective actions were performed and action plans were used for following-up and implementation of corrective actions. Finally, microbiological and physicochemical parameters were analyzed and the obtained results were regarded as appropriate. Therefore, it is shown that HACCP constitutes an effective tool for identification of hazards, establishment of corrective actions and monitoring of the critical control points that impact the process and the quality of the final pharmaceutical product most significantly.
Assuntos
Gestão de Riscos/classificação , Purificação da Água/instrumentação , Análise de Perigos e Pontos Críticos de Controle/métodos , Monitoramento Ambiental/instrumentação , Gestão da Qualidade Total/métodos , Indústria Farmacêutica/classificação , Metodologia como Assunto , Relatório de PesquisaRESUMO
Nowadays anticancer drugs (ADs), like other pharmaceuticals, are recognized as new emerging pollutants, meaning that they are not commonly monitored in the environment; however, they have great potential to enter the environment and cause adverse effects there. The current scientific literature highlights the problem of their presence in the aquatic environment by publishing more and more results on their analytics and ecotoxicological evaluation. In order to properly assess the risk associated with the presence of ADs in the environment, it is also necessary to investigate the processes that are important in understanding the environmental fate of these compounds. However, the state of knowledge on mobility of ADs in the environment is still very limited. Therefore, the main aim of our study was to investigate the sorption potential of two anticancer drugs, 5-fluorouracil (5-FU) and methotrexate (MTX), onto different soils. Special attention was paid to the determination of the influence of pH and ionic strength as well as presence of co-contaminants (cadmium (Cd2+) and another pharmaceutical-metoprolol (MET)) on the sorption of 5-FU and MTX onto soil. The obtained distribution coefficient values (Kd) ranged from 2.52 to 6.36 L·kg-1 and from 6.79 to 12.94 L·kg-1 for 5-FU and MTX, respectively. Investigated compounds may be classified as slightly or low mobile in the soil matrix (depending on soil). 5-FU may be recognized as more mobile in comparison to MET. It was proved that presence of other soil contaminants may strongly influence their mobility in soil structures. The investigated co-contaminant (MET) caused around 25-fold increased sorption of 5-FU, whereas diminished sorption of MTX. Moreover, the influence of environmental conditions such as pH and ionic strength on their sorption has been clearly demonstrated.
Assuntos
Monitoramento Ambiental/métodos , Poluentes Ambientais/química , Fluoruracila/química , Metotrexato/química , Extratos Vegetais/química , Poluentes do Solo/química , Solo/química , Adsorção , Cádmio/química , Monitoramento Ambiental/instrumentação , Poluentes Ambientais/análise , Concentração de Íons de Hidrogênio , Metoprolol/química , Concentração OsmolarRESUMO
Chemical treatment of sugarcane seed with fungicides and insecticides prior to planting increases yields of cane and sugar for the perennial, annually harvested crop. However, the fate of the applied chemicals is unknown. Therefore, the purpose of this study was to measure the aerobic dissipation of selected billet seed treatment chemicals in a mineral sugarcane soil from Louisiana. Soil samples from the surface 15 cm were treated with either thiamethoxam, azoxystrobin, fluxapyroxad, propiconazole, or pyraclostrobin and monitored over 100 days under laboratory conditions. Insecticide and fungicide levels were determined by high performance liquid chromatography. Dissipation data were fitted to four kinetic models: simple first-order (SFO), first order multi-compartment (FOMC), double-first order in parallel (DFOP), and hockey-stick (HS). The dissipation half-life (DT50) of thiamethoxam, azoxystrobin, fluxapyroxad, propiconazole, or pyraclostrobin were 275, 100, 144, 74, and 39 d, respectively. Overall, the DT50 for the pesticides in the study indicated medium to long persistence in soil under the conditions of the experiment. This is the first report for several of these pesticides related to the aerobic dissipation in soils used to grow sugarcane.
Assuntos
Cromatografia Líquida de Alta Pressão/métodos , Monitoramento Ambiental/métodos , Fungicidas Industriais/análise , Inseticidas/análise , Poluentes do Solo/análise , Solo/química , Cromatografia Líquida de Alta Pressão/instrumentação , Monitoramento Ambiental/instrumentação , Saccharum , SementesRESUMO
The hand-held mid-infrared diffuse reflectance infrared Fourier transform (MIR-DRIFT) spectrometer was used to assess the applicability of on-site and real time monitoring of total petroleum hydrocarbons (TPH) in contaminated soils during site characterization and remediation. Field measurement devices (MIR-DRIFT and turbidimetric screening test kits) were used to analyze reference soils with concentration ranging from 713 to 54790 mg/kg and compared with the results by a gas chromatography/mass spectrometry method (GC/MS). In situ field measurement of 147 petroleum-contaminated soil samples from 11 contaminated sites was correlated with laboratory-determined soil TPH levels by GC/MS. The concentrations of TPH by MIR-DRIFT were significantly correlated to the concentrations of TPH by GC/MS. Detection of TPH by the MIR spectrometer was not affected by the weathering effects of diesel-contaminated soils. Soils contaminated by mixed fuels with high content of gasoline constituents may cause the potential interference in MIR measurement. In field practice, interference may be attributed to soil moisture, soil organic matter, and soil texture. Soil moisture below 5% is required to reduce variation of infrared beam reflected from high level of surface liquid. When measuring the contaminated soil with a high organic matter content, the results may be overestimated due to the possible effects of surface reflection and interference. Clay and partial silty clay soils were not suitable for MIR spectrometer detection due to a potential shielding effect to reduce the infrared radiation absorbed by TPH. Future research is warranted to reduce the variation caused by soil texture and heterogeneity in TPH prediction.
Assuntos
Monitoramento Ambiental/métodos , Hidrocarbonetos/análise , Poluição por Petróleo/análise , Petróleo/análise , Poluentes do Solo/análise , Solo/química , Biodegradação Ambiental , Monitoramento Ambiental/instrumentação , Gasolina/análise , Espectrofotometria Infravermelho , TaiwanRESUMO
The Deepwater Horizon (DWH) oil spill from April to July of 2010 contaminated Gulf of Mexico waters through release of an estimated 4.1â¯×â¯106 barrels of oil. Beginning in June of 2010, semipermeable membrane devices (SPMDs) were deployed near areas with sensitive marine habitats (Alabama Alps and Western Shelf) potentially exposed to that oil. Elevated TPAH50 concentrations, flux rates and similarity of histograms and diagnostic ratios for polycyclic aromatic hydrocarbons (PAH) from SPMDs to weathered floating oil collected during the DWH spill indicates the Alabama Alps habitats were affected. While not affected by oil from the DWH spill, the temporal pattern of PAH contamination of SPMDs deployed near the Western Shelf between July 2010 and March 2011 could indicate prevailing currents affected contaminant transport to the Western Shelf Area (East and West Flower Garden, Sonnier, and Stetson Banks) from non-DWH sources, including oil and gas exploration, shipping, and Mississippi River effluent.
Assuntos
Monitoramento Ambiental/instrumentação , Poluição por Petróleo , Petróleo , Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Alabama , Florida , Golfo do México , Hidrocarbonetos , MississippiRESUMO
Low-cost particulate matter (PM) air quality sensors are becoming widely available and are being increasingly deployed in ambient and home/workplace environments due to their low cost, compactness, and ability to provide more highly resolved spatiotemporal PM concentrations. However, the PM data from these sensors are often of questionable quality, and the sensors need to be characterized individually for the environmental conditions under which they will be making measurements. In this study, we designed and assessed a cost-effective (â¼$700) calibration chamber capable of continuously providing a uniform PM concentration simultaneously to multiple low-cost PM sensors and robust calibration relationships that are independent of sensor position. The chamber was designed and evaluated with a Computational Fluid Dynamics (CFD) model and a rigorous experimental protocol. We then used this new chamber to calibrate 242 Plantower PMS 3003 sensors from two production lots (Batches I and II) with two aerosol types: ammonium nitrate (for Batches I and II) and alumina oxide (for Batch I). Our CFD models and experiments demonstrated that the chamber is capable of providing uniform PM concentration to 8 PM sensors at once within 6% error and with excellent reliability (intraclass correlation coefficientâ¯>â¯0.771). The study identified two malfunctioning sensors and showed that the remaining sensors had high linear correlations with a DustTrak monitor that was calibrated for each aerosol type (R2â¯>â¯0.978). Finally, the results revealed statistically significant differences between the responses of Batches I and II sensors to the same aerosol (P-value<0.001) and the Batch I sensors to the two different aerosol types (P-value<0.001). This chamber design and evaluation protocol can provide a useful tool for those interested in systematic laboratory characterization of low-cost PM sensors.
Assuntos
Poluentes Atmosféricos/análise , Poluição do Ar/análise , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Material Particulado/análise , Aerossóis/análise , Óxido de Alumínio/análise , Calibragem , Hidrodinâmica , Nitratos/análise , Tamanho da Partícula , Reprodutibilidade dos TestesRESUMO
Standard evaluation practice in public health remains limited to evaluative measures linked to individual projects, even if multiple interrelated projects are working toward a common impact. Enterprise evaluation seeks to fill this policy gap by focusing on cross-sector coordination and ongoing reflection in evaluation. We provide an overview of the enterprise evaluation framework and its 3 stages: collective creation, individual data collection, and collective analysis. We illustrate the application of enterprise evaluation to the Gulf Region Health Outreach Program, 4 integrated projects that aimed to strengthen health care in Louisiana, Mississippi, Alabama, and the Florida Panhandle after the Deepwater Horizon oil spill. Shared commitment to sustainability and strong leadership were critical to Gulf Region Health Outreach Program's success in enterprise evaluation. Enterprise evaluation provides an important opportunity for funding agencies and public health initiatives to evaluate the impact of interrelated projects in a more holistic and multiscalar manner than traditional siloed approaches to evaluation.
Assuntos
Política de Saúde , Poluição por Petróleo/efeitos adversos , Saúde Pública/métodos , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Golfo do México , Humanos , Poluição por Petróleo/análise , Poluição por Petróleo/estatística & dados numéricos , Saúde Pública/tendênciasRESUMO
Existing at the interface of biology and electronics, living cells have been in use as biorecognition elements (bioreceptors) in biosensors since the early 1970s. They are an interesting choice of bioreceptors as they allow flexibility in determining the sensing strategy, are cheaper than purified enzymes and antibodies and make the fabrication relatively simple and cost-effective. And with advances in the field of synthetic biology, microfluidics and lithography, many exciting developments have been made in the design of cell-based biosensors in the last about five years. 3D cell culture systems integrated with electrodes are now providing new insights into disease pathogenesis and physiology, while cardiomyocyte-integrated microelectrode array (MEA) technology is set to be standardized for the assessment of drug-induced cardiac toxicity. From cell microarrays for high-throughput applications to plasmonic devices for anti-microbial susceptibility testing and advent of microbial fuel cell biosensors, cell-based biosensors have evolved from being mere tools for detection of specific analytes to multi-parametric devices for real time monitoring and assessment. However, despite these advancements, challenges such as regeneration and storage life, heterogeneity in cell populations, high interference and high costs due to accessory instrumentation need to be addressed before the full potential of cell-based biosensors can be realized at a larger scale. This review summarizes results of the studies that have been conducted in the last five years toward the fabrication of cell-based biosensors for different applications with a comprehensive discussion on the challenges, future trends, and potential inputs needed for improving them.
Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas de Cultura de Células/instrumentação , Técnicas Analíticas Microfluídicas/instrumentação , Animais , Técnicas Biossensoriais/métodos , Técnicas de Cultura de Células/métodos , Células Imobilizadas/citologia , Células Imobilizadas/metabolismo , Avaliação Pré-Clínica de Medicamentos/instrumentação , Avaliação Pré-Clínica de Medicamentos/métodos , Monitoramento Ambiental/instrumentação , Monitoramento Ambiental/métodos , Desenho de Equipamento , Humanos , Técnicas Analíticas Microfluídicas/métodosRESUMO
The colorimetric sensing technology has evolved into an essential tool for high-throughput analysis including portability and cost-effectiveness among available biomedical and agricultural screening approach. In this endeavor, the objective of work is to focus on the development of a field-portable instrument based on an Uniform Illumination Imaging System (UIIS), which will facilitate the colorimetric biochemical sensing. The developed field-portable, wavelength independent UIIS has been exploited for (a) rotavirus detection using commercial enzymatic immunoassay based microplate kit; (b) pesticide residue detection and quantification; The proposed system exhibited a good correlation in comparison to another two conventional techniques, i.e., multi-plate reader (râ¯=â¯0.9991938) and LC-MS/MS (râ¯=â¯0.998877399) with a short analysis time of 5â¯min for 95 test samples. Moreover, the feasibility of UIIS system has also been explored as field-portable enzyme-linked immunosorbent assay (ELISA) plate reader. By incorporating the Mahalanobis distance calculation, the advanced algorithm has been investigated and developed to analyze the data. The overall dataset was transformed into a matrix format to give a good correlation with a conventional plate reader, i.e., râ¯=â¯0.915389612. Internet of things (IoT) enabled decision support system can be exploited by using big data analytics. Finally, test results can be shared with concerned stakeholders and the remote users. Thus, the developed UIIS will help to identify potential public health threats expeditiosly compared to conventional time consuming process of sample submission to the laboratory for analysis.
Assuntos
Colorimetria/instrumentação , Ensaio de Imunoadsorção Enzimática/instrumentação , Agricultura , Algoritmos , Calibragem , Cromatografia Líquida , Sistemas Computacionais , Monitoramento Ambiental/instrumentação , Desenho de Equipamento , Processamento de Imagem Assistida por Computador , Iluminação , Resíduos de Praguicidas/análise , Fosfatos/análise , Rotavirus , Espectrometria de Massas em Tandem , Chá/químicaRESUMO
Intermittent turbulent bursts have great impacts on sediment resuspension in coastal regions, tidal estuaries, and lakes. In this study, the role of turbulence structure on sediment resuspension was examined at Meiliang Bay of Lake Taihu, the third largest freshwater lake in China. The instantaneous three-dimensional velocity and suspended sediment concentrations were synchronously recorded by Acoustic Doppler Velocimetry (ADV) and Optical Backscatter Sensor (OBS) placed close to the lakebed. Statistical and quadrant analyses results revealed that the coherent structure contributed significantly to sediment particle entrainment. The intermittent burst events (dominant ejection and sweep) were the main energy source for sediment resuspension processes. 99.2% of turbulent sediment fluxes were triggered by ejection and sweep events, whereas the contributions coming from the outward interactions and inward interactions were relatively small. The large-amplitude burst events in the coherent structure dominated the influence on the sediment diffusion. Additionally, it was found that instantaneous sediment particle entrainment occurred earlier than the mean critical shear stress, which was induced by the stochastic nature of turbulence. The amount of sediment flux considering the turbulence characteristics was one or two larger magnitudes than the flux amount assessed by the time-averaged flow field, which indicated the critical shear stress approach might underestimate the sediment resuspension. Therefore, the influence of turbulence performance on sediment entrainment shall be seriously considered when evaluating sediment flux and internal nutrient loads in Lake Taihu.
Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Lagos/análise , Nitrogênio/análise , Fósforo/análise , China , Monitoramento Ambiental/instrumentação , Sedimentos Geológicos/análise , Lagos/química , Estresse Mecânico , VentoRESUMO
The study presents designating, accomplishing, optimizing, and validating a new tool - "passive sampler" (PS) that can be effectively used as a proxy to assess the level of traffic-related pollution. To construct the PS, a drainage pipe filled with a mixture of coarse sand and peat in a volume ratio of 1:1 was used; this was previously verified to exhibit high ability to accumulate pollutants. Magnetic methods supplemented with chemical method evaluating heavy metal content and electron microscopic observations were used to detect the effectiveness of the PS. The PS was validated in Warsaw, Poland, by observing the capacity and trends in the accumulation of traffic-related heavy metals as well as magnetic particles and by comparison of the properties of magnetic fraction of PS filling and street dust collected from the surface of road. A depth decreasing trend in distributions of magnetic susceptibility related to the concentration of magnetic particles and the content of heavy metals confirmed a very strong accumulation of pollution in the surface layer of samplers and their depth-migration. Magnetic fraction of PS filling and street dust revealed similarities in terms of magnetic mineralogy, grain size, domain state, morphology, and chemical composition. The good correlation of concentration of magnetic particles with traffic-related heavy metals indicates their similar transport pathway from road to sampler. Passive sampler is a compact, mobile, low-cost tool that does not require electricity for installation and can be effectively used for the identification of traffic-derived pollution. Moreover, the PS can overcome disadvantages of street dust arising from different geological backgrounds, cleaning of the road surface, runoff of deposited dust, etc., which cause the underestimation of pollution level.
Assuntos
Poeira/análise , Monitoramento Ambiental/instrumentação , Poluentes Ambientais/análise , Metais Pesados/análise , Monitoramento Ambiental/métodos , Poluição Ambiental/análise , PolôniaRESUMO
Water environment monitoring is of great importance to human health, ecosystem sustainability, and water transport. Unlike traditional water quality monitoring problems, this paper focuses on visual perception of water environment. We first introduce the development of a customized aquatic sensor node equipped with an embedded camera sensor. Based on this platform, we present an efficient and holistic contamination detection approach, which can automatically adapt to the detection of floating debris in dynamic waters or the identification of salient regions in static waters. Our approach is specifically designed based on compressed sensing theory to give full consideration to the unique challenges in water environment and the resource constraints on sensor nodes. Both laboratory and field experiments demonstrate the proposed method can fast and accurately detect various types of water pollutants and is a better choice for camera sensor-based water environment monitoring compared with other methods.
Assuntos
Monitoramento Ambiental/instrumentação , Fotografação/instrumentação , Poluentes Químicos da Água/análise , Ecossistema , Monitoramento Ambiental/métodos , Qualidade da ÁguaRESUMO
The aim of this study is to evaluate the performance level of two advanced oil spill software systems in early transport and fate of oil spill through algorithms accepted in oil spill literature. To do this, the performance level of software systems mostly used in real cases have been compared. OILMAP (the oil spill prediction modeling system) and PISCES 2 (potential incident simulation, control and evaluation system) have been used for spill trajectory in the light of four spill scenarios. The findings reveal that the OILMAP has predicted a relatively larger area of spill. In addition, OILMAP has achieved closer results to the calculations of approaches adopted in the literature for evaporation calculations. Besides, OILMAP software has provided highly reliable results in the evaporation rates of oil compared to the calculations of PISCES 2. On the other hand, as for the determination of the risky area, both software systems have yielded results with high reliability values, which could be used in taking precautions against oil spill in such areas.
Assuntos
Monitoramento Ambiental/métodos , Poluição por Petróleo/análise , Software , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , Baías , Monitoramento Ambiental/instrumentação , Petróleo/análise , Poluição por Petróleo/estatística & dados numéricos , Reprodutibilidade dos Testes , Poluição Química da Água/estatística & dados numéricosRESUMO
An experimental chamber (CIME2) has been specially designed to simulate wet atmospheric deposition on limestones used in Paris cultural heritage. This instrument is a complementary tool to CIME, a previously developed chamber dedicated to the simulation of dry atmospheric deposition on monuments and artifacts. The aim of this paper is to describe CIME2 and characterize the wet deposits produced inside it. Mist (fog), drizzle, and rainfall are differentiated in order to document their ability to saturate the limestones most currently used in Paris monuments: The Saint-Maximin's limestone, the Liais of Saint-Maximin, and the Chauvigny's limestone are tested. The comparison between normalized and environmental petrophysical data shows that in the wet deposition simulations, limestones are not systematically water-saturated. Moreover, the realistic experimental conditions chosen favor a more rapid evaporation of the stone water. The quantification of the non-saturation state is a first step that has to be taken into account to improve the geochemical models used to predict the alteration.
Assuntos
Carbonato de Cálcio/química , Monitoramento Ambiental/métodos , Água/análise , Monitoramento Ambiental/instrumentação , Paris , Chuva , Tempo (Meteorologia)RESUMO
In this work, both PM10 filters and leaves have been collected, on a daily basis, over a period of five months and compared systematically. Filters were taken from an air-quality monitoring station and leaves from two Tilia cordata trees, both located near the railway station of Parma. SEM-EDS analysis on the surface and across the leaves shows that magnetic particles are almost entirely made of magnetite, and that they are found invariably on the leaves surface. The saturation isothermal magnetic remanence (SIRM) shows that for both filters and leaves the magnetic fraction mainly consists of a low coercivity, magnetite-like phase. The magnetic signals of filter and leaves and atmospheric PM concentrations are compared. The correlation is better for filters, mostly with parameters related to vehicular pollution, and improved for both filters and leaves once data were averaged on a 10 days basis. Filters and leaves equally show an increase in magnetic signal during the fall-winter period together with PM10 content. The comparison between leaves and filters shows that: 1) leaves give a qualitative picture, and in our case they could be used as environmental proxies after averaging the results over multiple days; 2) the correlation with PM10 is weaker, indicating that there is a PM10 contribution from non-magnetic particles, like calcite and clay minerals, pollen and spores; 3) multidomain particles contribution from filters indicates a strong relation with vehicular polluters, suggesting the important role of larger particles; 4) magnetization from leaves and filters are weakly related, due to the different sampling lapse.
Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Material Particulado/análise , Folhas de Planta/química , Tilia/química , Filtros de Ar , Poluição do Ar/análise , Animais , Cidades , Monitoramento Ambiental/instrumentação , Itália , Magnetismo , Estações do AnoRESUMO
Identification of hot spots of land degradation is strongly related with the selection of soil tracers for sediment pathways. This research proposes the complementary and integrated application of two analytical techniques to select the most suitable fingerprint tracers for identifying the main sources of sediments in an agricultural catchment located in Central Argentina with erosive loess soils. Diffuse reflectance Fourier transformed in the mid-infrared range (DRIFT-MIR) spectroscopy and energy-dispersive X-ray fluorescence (EDXRF) were used for a suitable fingerprint selection. For using DRIFT-MIR spectroscopy as fingerprinting technique, calibration through quantitative parameters is needed to link and correlate DRIFT-MIR spectra with soil tracers. EDXRF was used in this context for determining the concentrations of geochemical elements in soil samples. The selected tracers were confirmed using two artificial mixtures composed of known proportions of soil collected in different sites with distinctive soil uses. These fingerprint elements were used as parameters to build a predictive model with the whole set of DRIFT-MIR spectra. Fingerprint elements such as phosphorus, iron, calcium, barium, and titanium were identified for obtaining a suitable reconstruction of the source proportions in the artificial mixtures. Mid-infrared spectra produced successful prediction models (R2 = 0.91) for Fe content and moderate useful prediction (R2 = 0.72) for Ti content. For Ca, P, and Ba, the R2 were 0.44, 0.58, and 0.59 respectively.
Assuntos
Agricultura , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Solo/química , Argentina , Calibragem , Monitoramento Ambiental/instrumentação , Poluentes do Solo/análise , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Exposure to occupational aerosols are a known hazard in many industry sectors and can be a risk factor for several respiratory diseases. In this study, a laboratory evaluation of low-cost aerosol sensors, the Dylos DC1700 and a modified Dylos known as the Utah Modified Dylos Sensor (UMDS), was performed to assess the sensors' efficiency in sampling respirable and inhalable dust at high concentrations, which are most common in occupational settings. Dust concentrations were measured in a low-speed wind tunnel with 3 UMDSs, collocated with an aerosol spectrometer (Grimm 1.109) and gravimetric respirable and inhalable samplers. A total of 10 tests consisting of 5 different concentrations and 2 test aerosols, Arizona road dust and aluminum oxide, were conducted. For the Arizona road dust, total particle count was strongly related between the spectrometer and the UMDS with a coefficient of determination (R2) between 0.86-0.92. Particle count concentrations measured with the UMDS were converted to mass and also were related with gravimetrically collected inhalable and respirable dust. The UMDS small bin (i.e., all particles) compared to the inhalable sampler yielded an R2 of 0.86-0.92, and the large bin subtracted from the small bin (i.e., only the smallest particles) compared to the respirable sampler yielded an R2 of 0.93-0.997. Tests with the aluminum oxide demonstrated a substantially lower relationship across all comparisons. Furthermore, assessment of intra-instrument variability was consistent for all instruments, but inter-instrument variability indicated that each instrument requires its own calibration equation to yield accurate exposure estimates. Overall, it appears that the UMDS can be used as a low-cost tool to estimate respirable and inhalable concentrations found in many workplaces. Future studies will focus on deployment of a UMDS network in an occupational setting.