Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 14 de 14
Filtrar
Mais filtros








Base de dados
Intervalo de ano de publicação
1.
Sci Rep ; 14(1): 11943, 2024 05 24.
Artigo em Inglês | MEDLINE | ID: mdl-38789449

RESUMO

The volatile particles and molecules in our dry exhaled breath can reveal enormous information about the health of any person, such as the person's respiratory and metabolic functioning. Beyond the carbon dioxide level is an indicator of life, it provides important health-related data like people's metabolic rate. This study considers periodic open and closed resonators for measuring carbon dioxide concentration in dry exhaled breath. Transfer matrix and green methods are used to simulate the interaction between acoustic waves and the proposed sensor. The band gaps using the green method coincide with the transmittance spectra by the transfer matrix. The suggested sensor recorded a sensitivity of 5.3 H z . m - 1 . s , a figure of merit of 10,254 m - 1 . s , a detection limit of 5 × 10 - 6 m . s - 1 , and a quality factor of 3 × 10 6 . Furthermore, the efficiency shows that the proposed design is appropriate as a diagnostic sensor for different diseases such as chronic obstructive pulmonary. Besides, cylindrical-adapted sensors are urgently needed in medicine, industry, and biology because they can simultaneously be used for fluid transport and detection.


Assuntos
Técnicas Biossensoriais , Testes Respiratórios , Dióxido de Carbono , Técnicas Biossensoriais/métodos , Técnicas Biossensoriais/instrumentação , Humanos , Dióxido de Carbono/análise , Testes Respiratórios/métodos , Testes Respiratórios/instrumentação , Expiração
2.
Mar Pollut Bull ; 198: 115830, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37995594

RESUMO

The present work was conducted to characterize the mangrove sediments along the Egyptian Red Sea in terms of elemental composition and to assess the extent of pollution and its sources. A total of 26 samples of mangrove sediments were collected from three different areas: Sharm El Madfea, Sowmaa Mangrove and Abu Fasi. The samples were analyzed using the inductively coupled plasma - mass spectrometry ICP-MS and atomic-emission spectrometry ICP-AES. Mass fractions of a total of 58 major and trace elements were determined in the mangrove samples. Univariate and multivariate statistical analyses were performed to determine the origin of trace and major elements in the mangrove sediments. The normalized values show that the elements above the background can be indicated in descending order as follows: P > Cd > Sr > Ca > U > Se > As > Sn > Cu > Sb > Pb > Mo > Ag. Several pollution indices were also calculated. Principal component analysis revealed three clusters of the studied sediment samples. The analysis of the ratio indicators shows that the origin of the sediments mostly falls near continental island arcs (CIA). The pollution indices show remarkable pollution levels and enriched elements. The data obtained can serve as baseline data for the sediments of the mangrove environment and can be used to study possible changes in the future.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Oceano Índico , Egito , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Metais/análise , Metais Pesados/análise
3.
Isotopes Environ Health Stud ; 60(1): 90-102, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37997342

RESUMO

ABSTRACTEnvironmental and health risks posed by radionuclides in quarry pit soils are of great concern in environmental health monitoring. The current investigation was aimed at determining the natural radionuclide activity concentration (in Bq kg-1) of the understudied quarry pit granules used as construction materials. The collection and preparation of pit soil samples from Abeokuta quarry sites were done using standard methods, analysis of radiological parameters was carried out using hyperpure germanium (HPGe) spectrometer. Specific activity concentrations of 226Ra, 232Th, and 40K were measured. The values obtained were greater than the world weighted average of 35, 30, and 400 Bq kg-1 for 226Ra, 232Th, and 40K, respectively. The absorbed dose, the annual effective dose, and the radium equivalent were calculated and demonstrated significant values. The radionuclide content of the samples is relatively high and the use of pit soils as a building material, therefore, raises radiological concerns for dwellers in this area and requires periodic monitoring and undergoing a radiation protection program.


Assuntos
Monitoramento de Radiação , Rádio (Elemento) , Poluentes Radioativos do Solo , Doses de Radiação , Monitoramento de Radiação/métodos , Radioisótopos de Potássio/análise , Solo , Nigéria , Saúde Pública , Poluentes Radioativos do Solo/análise , Tório/análise , Radioisótopos/análise , Materiais de Construção/análise , Rádio (Elemento)/análise , Medição de Risco
4.
Data Brief ; 48: 109051, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36950559

RESUMO

These are comprehensive baseline data on the geochemical composition of archeological ceramics analyzed using instrumental neutron activation analysis (INAA). The data obtained support the research article conducted to evaluate the elemental composition of 70 sherds that were collected from different locations [1], [2], [3]. The mass fractions in wt% and in mg/kg of 39 oxides and elements were determined, respectively. Quality control of analytical measurements was carried out using different certified reference materials. Univariate and multivariate statistical analyses were performed. The common geochemical composition of the archeological pottery was used to decipher the provenance of ceramics and to establish reference groups based on various statistical approaches. For instance, hierarchical clustering (HC), linear discriminant analysis (LDA), principal component analysis (PCA) were used. The data was used to extract information about the important elements using machine learning (ML) methods. The obtained data show that chromium was the most important element and was used along with other elements as a fingerprint to distinguish the fragments. The chemical and statistical analyzes help to establish reference groups for medieval archeological pottery, which will be used in the future to classify and identify various unknown sherds. These reference groups serve as baseline data for determining where the fragments were made and are considered a reasonable judgment based on experimental data.

5.
Data Brief ; 42: 108217, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35539025

RESUMO

A comprehensive dataset concerning the geochemical composition of unconsolidated shallow marine sediments collected along coastal areas of Northern Nile Delta and Egyptian sector of Red Seas is presented. The sediment samples were analyzed using instrumental neutron activation analysis (INAA) in Frank Laboratory of Neutron Physics FLNP - Joint Institute for Nuclear Research JINR and inductively coupled plasma - mass spectrometer (ICP-MS) in Actlabs - Canada. Data thus collected supported the research published and published articles conducted to evaluate the geochemistry of shallow marine sediments covering mentioned areas [1], [2], [3]. The mass fractions of 43 and 39 trace elements and oxides were determined in the unconsolidated marine sediments of Northern Nile Delta and Egyptian sector of Red Sea, respectively. Final data were expressed in wt.% and mg/kg for major and trace elements, respectively. Different statistical tests such as Shapiro-Wilk, Anderson-Darling, Lilliefors and Jarque-Bera were used to check the normality of data. At the same time, distribution patterns of the rare earth elements (lanthanides) as well as Eu and Ce anomalies were investigated. Quality control of analytical measurements was carried out using certified reference materials. Different univariate and multivariate as well as graphic statistical analyses were performed. Presented data were used in identifying, by means of more pollution indices, the degree of local contamination. The present dataset could be further used in establishing geochemical background for the studied areas and tracking eventually changes posing significant threat to environment and humans.

6.
Appl Radiat Isot ; 183: 110152, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35217327

RESUMO

The first experiments were carried out to study the elemental composition of archaeological ceramics using prompt gamma activation analysis (PGAA) at the pulsed reactor IBR-2, Frank Laboratory of Neutron Physics (FLNP) - Joint Institute for Nuclear Research (JINR). A radiation-resistant n-type High Purity Germanium (HPGe) detector was used to measure the radioactivity. The concentrations of 14 elements were determined namely; Al, C, Ca, Fe, Gd, H, K, Mn, Na, P, S, Si, Sm, and Ti. The obtained results were compared with those analyzed by other analytical techniques INAA (Instrumental Neutron Activation Analysis) and portable X-ray fluorescence (XRF) for the same archaeological batches. The results revealed a good agreement within a range of 1-30%. These insights will contribute to the discussion of improving the PGAA installation and automation of the data obtained, which in turn will improve the quality of analysis and increase the number of determined elements. In this work results are presented, and the analytical merits are compared.

7.
Environ Sci Pollut Res Int ; 29(14): 21049-21066, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34750760

RESUMO

The present work was conducted to evaluate the air quality in terms of inorganic pollutants and toxicity impact using two evergreen tree leaves, Eucalyptus globulus Labill (E. globulus) and Ficus microcarpa L.f., Suppl. Pl. 442 (1782) (F. microcarpa) as biomonitors. Thirty tree leaves and an equal number of co-located soil samples from different regions of Egypt (urban Greater Cairo Metropolitan (GC) and rural Menoufia Governorate (MG)) were collected. The concentrations of 34 and 40 elements were determined using instrumental neutron activation analysis (INNA) and atomic absorption spectrometry (AAS) in tree leaves and soils, respectively. Bivariate and multivariate statistical analyses were implemented. The air pollution was assessed using enrichment factor, pollution load index, potential ecological risk, and risk index. In addition, human and ecotoxicity were evaluated based on the ReCiPe method. The mean concentration values of the obtained elements in tree leave in urban Greater Cairo and rural Menoufia Governorate show that the major elements are slightly higher in F. microcarpa than in E. globulus. Likewise, the mean values of elements in soil from GC and MG show no significant difference except for major elements (Fe, Al, Mg, K, Na, and Ti) in MG. The normalized concentrations of tree leave and soil show that the accumulated elements by F. macrocarpa are slightly higher than in E. globulus in GC and MG. While in terms of the investigated area, the concentrations of elements in MG are considerably higher than in GC. Pollution load index (PLI) spatial distribution over investigated areas showed that despite high population density, heavy traffic, and urban pollution, the Cairo samples exhibit significantly lower values as compared to those from Menoufia, which is most likely due to the uncontrolled industrial and domestic waste disposal outside Cairo. Potential ecological risk (PER) was significant for As in soil and for As and Cd in tree species. Human toxicity shows higher values in urban locations. Contrariwise, in the terrestrial ecotoxicity aspect, the rural locations are much higher than in urban ones.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Metais Pesados , Poluentes do Solo , Poluentes Atmosféricos/análise , Poluição do Ar/análise , Egito , Monitoramento Ambiental/métodos , Humanos , Metais Pesados/análise , Solo , Poluentes do Solo/análise
8.
Appl Radiat Isot ; 170: 109595, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33556692

RESUMO

The present review was conducted to highlight the major and trace elemental composition in surface sediments from the Nile River and Egyptian Red Sea coastal areas in terms of provenance, concentrations, pollution indices, and health hazards. Health hazard due to the exposure to selected elements via inhalation, ingestion, and dermal contact was calculated. The samples were subjected to neutron activation analysis. Bivariate and multivariate statistical analysis was employed. Significant amounts of V, Cr, and Zr are observed in Nile sediments. Whereas, considerable concentrations of Br and Ca were found in marine sediments. The concentrations of the other elements are in line with the corresponding values in upper continental crust. The outcomes of the pollution indices show some localized polluted sites (Helwan, Cairo, and Delta) in Nile sediments. Likewise, in Abu Ghusun area in marine ones. Overall, the hazard index of the investigated elements in the Nile and marine sediments for both studied age criteria is higher than the tolerable values (1 × 10-6 - 1 × 10-4).


Assuntos
Água Doce/química , Sedimentos Geológicos/química , Água do Mar/química , Oligoelementos/análise , Oligoelementos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Egito , Metais Pesados/análise , Metais Pesados/toxicidade
9.
Arch Environ Contam Toxicol ; 80(2): 350-367, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33236186

RESUMO

The present work was conducted to obtain and highlight the first comprehensive baseline data on atmospheric deposition of trace elements and to evaluate the air quality in Georgia. A total of 120 moss samples were collected over accessible territories in Georgia in the period from 2014 to 2017. Hylocomium splendens (Hedw.) Schimp., Hypnum cupressiforme (Hedw.), and Pleurozium schreberi (Brid.) Mitt. moss species were analyzed by two complementary analytical techniques: instrumental neutron activation analysis and atomic absorption spectrometry. Concentrations of 41 elements in mg/kg were determined. The concentrations were compared with the corresponding values in the literature and are in a good agreement, except for the concentration of Mg, Al, K, Ca, Ti, and Fe, which were higher than those reported for other countries. The principal component and discriminant analyses were implemented to extract information about the similar geochemical features and to decipher the provenance of the studied elements. The analysis showed that a considerable association of crustal elements and the provenance of elements can be considered as a mixture of geogenic and anthropogenic sources. In addition, the influence of different latitudinal climate zones on the distribution of elements in the atmospheric deposition was observed. The enrichment factor shows considerable values for Th and Zr. The spatial distribution of the pollution load index identifies four zones (#12, 38, 53, and 64). The potential ecological risk index and the risk index were calculated and it does not pose significant risk except As and Cd. The data obtained can be used as the first dataset of metal characterization of air pollution in Georgia.


Assuntos
Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Oligoelementos/análise , Poluição do Ar/análise , Monitoramento Biológico , Briófitas/química , Bryopsida/química , Georgia , Metais/análise , Metais Pesados/análise , Análise de Ativação de Nêutrons , Espectrofotometria Atômica , Titânio
10.
Data Brief ; 28: 105009, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31921946

RESUMO

This data is the first comprehensive baseline data on the geochemical composition of soil and sediments along the Nile River and Delta in Egypt that was subjected and analyzed by instrumental neutron activation analysis INAA. These data supported the research articles that were done to evaluate the elemental compositions and pollution sources in 176 sampling locations through 133 soil and 43 sediments samples along the Egyptian section of the Nile River and Delta - Egypt. "Geochemistry of sediments and surface soils from the Nile delta and lower Nile valley studied by epithermal neutron activation analysis" Arafa [1], "Major and trace element distribution in soil and sediments from the Egyptian central Nile valley" Badawy [2], and "Assessment of industrial contamination of agricultural soil adjacent to Sadat city, Egypt" Badawy [3]. The samples were analyzed by means of instrumental neutron activation analysis INAA and the concentrations in mg/kg of 28 major and trace elements are obtained. The quality control of the analytical measurements was carried out using different certified reference materials. Multivariate statistical analyses were applied. A total of eight individual and complex pollution indices were calculated in terms of the quantification of pollution extent and selection of the proper index based on the method and purpose of calculations. The spatial distribution of pollution load index PLI was mapped using GIS-technology. The normalized concentrations of the determined elements show no significant difference between soil and sediments concentrations and this, however, may be explained by the fact that origin of soil mainly is the sediments. To a clear extent, the concentrations of Ti (8017, 9672 mg/kg), V (124, 143 mg/kg), Cr (126, 160 mg/kg), and Zr (296, 318 mg/kg) are observed to be high in soil and sediments, respectively relative to other elements. Zr/Sc ratio shows a reduced sedimentary recycling and this may be explained by the tremendous influence of Aswan High Dam in preventing sediments supply from Ethiopian Highlights. Eventually, the pollution indices prove their suitability for assessing the individual and integrative contamination and show that there is no overall contamination. However, there are some contaminated localities mainly in Delta and mostly due to the dense population and anthropogenic activities. The data can be used as a raw data for constructing the first ecological atlas and evaluation of the ecological situation in terms of geochemistry and pollution.

11.
Appl Radiat Isot ; 156: 108970, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31787489

RESUMO

Water transport into construction building materials is an important subject since it may deteriorate them because it can carry harmful biological and chemical substances. Some of the reported results in literature for moisture transport in construction building materials follow Fick's law of diffusion while others show anomalous diffusion. There is not enough reliable and accurate data in the literature to discuss this issue. Therefore, in the present work moisture transport into four different kinds of brick samples was studied using the real time neutron radiography method. Neutron radiography images were registered continuously during the moisture absorption process. Simple procedures based on the Cd-umbrella method were used for the first time to correct for the neutron scattering during the water absorption process. The images showed clearly that the absorption process is different from one sample to another. The water content distribution along the flow direction, x (profiles) and positions of water front as the time of moisture absorption elapses were determined from the images obtained. The results obtained showed that the water front positions do not scale with the square root of the absorption time. It was shown that moisture diffusion processes in the samples investigated could be described by an anomalous diffusion approach of the sub-diffusive type. The moisture diffusivities were determined for every sample. The neutron radiography method and the neutron scattering correction procedures used are proven to be a powerful and effective for studying transport process in porous media.


Assuntos
Nêutrons , Radiografia/métodos , Água/análise , Porosidade
12.
Appl Radiat Isot ; 151: 171-181, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31200192

RESUMO

The present study was conducted to study the compositional trends of rare earth elements (REEs), Th, and U in marine sediment samples in terms of distribution patterns, anomalies, and indicator ratios. For this purpose, a total of 32 marine sediment samples were collected from 12 coastal areas of the Egyptian Red Sea and analyzed using instrumental neutron activation (INAA) and inductively coupled plasma mass spectrometry (ICP-MS) analytical techniques. The analyses investigated 14 REEs, Th, and U. The results revealed that the contents of REE, light REE (LREE), and heavy REE (HREE) are 47.6, 38.7, and 8.3 mg/kg, respectively, whereas the concentration of Th and U is determined as 2.15 and 2.23 mg/kg, respectively. Indicator ratios were calculated, and inter-correlation elements with Th and U were constructed. Multivariate statistics were implemented on the data and GIS technology to construct the distribution patterns of REE, Th, and U along the Egyptian coast of the Red Sea. The obtained results were compared with the corresponding values published in literature to show a good matching. There is a significant enrichment of LREE relative to HREE, a reduced ratio of Th/U, a weak positive anomaly of Eu/Eu*, and a slight positive Ce anomaly is noticed. Among the 12 studied areas, one area, Sharm El-Bahari, located in the middle of the coast, shows peak values of REE, Th, and U relative to the other areas. However, it still shows a good agreement with the results published in the literature.


Assuntos
Sedimentos Geológicos/química , Metais Terras Raras/análise , Oceanos e Mares , Poluentes Químicos da Água/análise , Poluentes Radioativos da Água/análise , Egito , Monitoramento Ambiental/métodos , Sistemas de Informação Geográfica
13.
Appl Radiat Isot ; 140: 314-326, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30114618

RESUMO

The present study was conducted to assess the possible impacts of human activities and naturally occurring on the marine sediments, to test for anomalous enrichments in metals. A total of 32 marine sediments samples collected from 12 coastal areas of the Egyptian Red Sea analyzed using different analytical techniques. The analysis explored 43 elements for the marine sediments. Principal component analysis and multivariate statistics were implemented on the data. The extent of pollution was quantified for selected 6 pollutants using the geoaccumulation indices (Igeo), enrichment factor (EF), metal pollution index (MPI), contamination factor (Cf), and degree of contamination factor (Cd). The associated risk using potential ecological risk factor (PER), and risk index (RI) was calculated. The data was interpolated using ArcGIS technology to construct the spatial distribution maps of the selected 6 pollutants along the coastal areas of the Egyptian Red Sea. The data was normalized and the peak values were observed for Ca (13.6%) >Na (1.9%) > Mg (1.6%) >Br (41.1 ppm). The obtained findings were compared with other local and regional data shows that the metal enrichment in studied areas is in line and anomalous enrichments in metals were not evidenced. Even though out of 12 studied areas 2 areas viz., Sharam El-Bahari in the middle of the coast and downwards to the southern Marsa Hemira area found to have peak values of metals, however still show a good agreement with results with other data. Moderate enriched sediments with Cr were noticed. It could be stated that comparison of the gained data from this study with others clearly indicates that nearly the metal concentrations were in the natural unpolluted sediments range.


Assuntos
Poluentes Ambientais/análise , Sedimentos Geológicos/análise , Metais/análise , Egito , Humanos , Oceano Índico , Espectrometria de Massas , Análise de Ativação de Nêutrons
14.
Isotopes Environ Health Stud ; 54(5): 535-547, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-29873250

RESUMO

The activity concentrations of natural 40K, 232Th, and 238U in 89 soil and 84 sediment samples collected over the entire Egyptian Nile River basin including the Nile delta are reported based on the results of epithermal neutron activation analysis. The average activity concentrations of 40K, 232Th, and 238U equal to 15.3 ± 6.6, 15.6 ± 11.1 and 220 ± 31 Bq/kg, respectively, are significantly lower than those reported for the Upper Continental Crust, World Average Sediments as well as World Average Soils, suggesting the presence of a considerable portion of mafic material, most probably originating from the Ethiopian High Plateau. Their average activity concentrations are statistically the same in soil and sediments, indicating that the Nile sediments and soil material are of the same origin. The main goal of this study was not only to estimate the radiological hazards but also to show the influence of sedimentary material transportable by the Blue Nile from the Ethiopian High Plateau. The different hazard indices like the radium equivalent, gamma index, external hazard as well as the internal hazard show a low radiological exposure either on direct contact or if local mud bricks are used in the construction of dwellings.


Assuntos
Sedimentos Geológicos/análise , Radioisótopos de Potássio/análise , Rios , Tório/análise , Urânio/análise , Egito , Sedimentos Geológicos/química , Análise de Ativação de Nêutrons/métodos , Monitoramento de Radiação/métodos , Solo/química , Poluentes Radioativos do Solo/análise
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA