Near InfraRed Spectroscopy (NIRS) has become an extremely important analytical technique in recent years and been applied in various geoscience areas such as mineral exploration and environmental studies. It is used f...Near InfraRed Spectroscopy (NIRS) has become an extremely important analytical technique in recent years and been applied in various geoscience areas such as mineral exploration and environmental studies. It is used for studying the physico-chemical properties of earth materials by enabling the interpretation of mineral composition and the study of its variability based on the diagnostic of spectral features. In this research, the application of laboratory reflectance spectroscopy in assessing heavy metals pollution is investigated. The potential use of reflectance spectroscopy in detecting Fe-related and clay minerals as well as the quantitative characterization of pollutants is studied for the mine waste of Jalta and Bougrine in the North of Tunisia. Mining activities of lead/Zn, have led to extensive pollution. The analysis of geochemical results outlined the level and spatial pattern of pollutants concentration. Results of the study showed that a relationship exists between reflectance spectra and geochemical measures of pollutants. The Spectral interpretation of Fe-related minerals and clay minerals showed that they are related to the pollutants and can be used as indirect spectral indicators of the pollution. The Fe-minerals include: jarosite, goethite, hematite/goethite, and hematite;clay minerals and feature-less (aspectral) materials. A direct quantitative relationship between pollutants and spectral parameters shows that Pb-Zn-Mn are the best correlated with a ratio of 610/500 nm range while Ni-Cr have a best correlation with a slope around 980 nm. Outputs from Partial Least Square Regression (PLSR) confirmed these relationships and also indicated that spectral parameters and reflectance values within 400 - 2500 nm range can better predict the contamination for Mn, Pb and Zn than for Ni and Cr but not for Fe, Cu, Cd, EC and pH.展开更多
The tidal flat of Nakta is located in the northern part of the gulf of Gabes and in the southern coast of Sfax. It corresponds to a flat reef protected from less topography, with a slope ranging between 2° and 4&...The tidal flat of Nakta is located in the northern part of the gulf of Gabes and in the southern coast of Sfax. It corresponds to a flat reef protected from less topography, with a slope ranging between 2° and 4°, which borders the Gargour Wadi. The study sector is renowned to have moderate hydrodynamics which lasts almost for two millenary (14C isotopic dating). The sedimentological study of the Nakta tidal flat revealed different facies: fine-grained sand in the intertidal zone and carbonated muddy sand in the infratidal zone. Equilibrium state of the Nakta ecosystem depends entirely on tide currents, which mainly inhibit drift currents. The Nakta tidal flat is characterized by a variety of faunal species (Cerastoderma glaucum, Arca noe, Cardita antiquatus, Chlamys varied, Ruditapes deccussatus, Tapes rhomboids, Pinctada radiate, etc.) and floristic diversities (Halocnemum strobilacum, Halimione portulacoides, Enteromorpha linza, Ulva rigida, Cymodocea nodosa, Posidonia oceanica). The species are abundant in the infratidal zone, while in its intertidal zone, faunal species remain little diversified and are dominated by limivorous diggering. The paleogeographic study of the Nakta tidal flat showed the alternation of regression and transgression periods.展开更多
Gravity data associated with surface geology in the Northern Tunisian Atlas offer better understand to the underlying structures in Teboursouk area and to highlight other deep or unknown structures in surface. The gra...Gravity data associated with surface geology in the Northern Tunisian Atlas offer better understand to the underlying structures in Teboursouk area and to highlight other deep or unknown structures in surface. The gravity study was based on qualitative and quantitative analysis including the construction of the gravity Bouguer anomaly, upward continuations, residual anomaly, and Horizontal gradient maxima maps. The main results display many positive and negative anomalies as the response of geological structures (J. Cheid Triassic structure, Khalled plain, El Aroussa plain). In addition, the horizontal gradient maxima integrated with geological and structural maps let the identification of major directions of gravimetric lineaments in the study area us NE-SW trending features at the boundaries of J. Cheid structure, NW-SE direction that limit Gaafour plain and Tabet Ech Cherif syncline, and N-S trending that bordered El Aroussa basin. Major results allowed the construction of a new structural map of the study zone.展开更多
Stream networks are considered important units in many environmental decision making processes. The extraction of streams using digital elevation models (DEMs) presents many advantages. However it is very sensitive to...Stream networks are considered important units in many environmental decision making processes. The extraction of streams using digital elevation models (DEMs) presents many advantages. However it is very sensitive to the uncertainty of the elevation datasets used. The main aim of this paper is to implement geostatistical simulations and assess the propagated uncertainty and map the error of location streams. First, point sampled elevations are used to fit a variogram model. Next two hundred DEM realizations are generated using conditional sequential Gaussian simulation;the stream network map is extracted for each of these realizations, and the collection of stream networks is analyzed to quantify the error propagation. At each grid cell, the probability of the occurrence of a stream and the propagated error are estimated. The more probable stream network are delineated and compared with the digital stream network derived from topographic map. The method is illustrated using a small dataset (8742 sampled elevations) for Anaguid Saharan platform. All computations are run in two free softwares: R and SAGA. R is used to fit variogram and to run sequential Gaussian simulation. SAGA is used to extract streams via RSAGA library.展开更多
Hydrogen-bonded polar nematic liquid crystal series with the general formula n OBAF(n = 7-12) is studied. The mesomorphic characterization is demonstrated through differential scanning calorimetry(DSC) and polarized o...Hydrogen-bonded polar nematic liquid crystal series with the general formula n OBAF(n = 7-12) is studied. The mesomorphic characterization is demonstrated through differential scanning calorimetry(DSC) and polarized optical microscopy(POM). The complexes with short alkyl chains(n = 7, 8) present a wide nematic range and monotropic smectic F mesophase, whereas the longer alkyl chain(n = 10-12) analogues show high melting and low clearing mesomorphic liquid crystals. The thermal range of the mesophase and the birefringence increase with chain length decreasing. Furthermore, the effect of the nanoparticles(LiNbO_(3)) on the thermal and the electrical behavior of 8OBAF are investigated. The presence of LiNbO_(3) nanoparticles increases the conductivity and reduces the resistivity of the complex.展开更多
A new cobalt diphosphate (Na0.71Ag0.29)2CoP2O7, is synthesized by solid state reaction method and characterized by single-crystal X-ray diffraction. The title material crystallizes in the triclinic space group P-1 wit...A new cobalt diphosphate (Na0.71Ag0.29)2CoP2O7, is synthesized by solid state reaction method and characterized by single-crystal X-ray diffraction. The title material crystallizes in the triclinic space group P-1 with a = 6.4170(3) , b = 9.4510(2) , c = 10.9350(3) , a = 115.240(2)o, b = 80.190(3)o and g = 106.810(2)0. The structure presents a centro-symmetrical clusters Co4P4O28 consists of two Co2O11 units and two P2O7 pyrophosphate groups. The junction between clusters is assured by two P2O7 groups to form a three-dimensional anionic framework having different interconnecting tunnels running along [100] and [010]. The former contains the Na+ and Ag+ cations. The conductivity measurements of (Na0.71Ag0.29)2CoP2O7 are studied over a temperature interval from 783 to 903 K using the frequency response analyzer with 0.5 V amplitude signal over the range of 13 MHz - 5 Hz.展开更多
Intrathoracic mesothelial cysts are congenital lesions due to an abnormal development of the pericardial coelom. They are generally unilocular and can develop in various sites. We describe a case of multicystic lesion...Intrathoracic mesothelial cysts are congenital lesions due to an abnormal development of the pericardial coelom. They are generally unilocular and can develop in various sites. We describe a case of multicystic lesions in the anterior mediastinum of a 53-year-old woman discovered in a context of an encysted pleural effusion. Chest computed tomography (CT) scan revealed multiple cystic lesions in the anterior and posterior mediastinum. Surgery was carried out and histopathology and immunohistochemistry confirmed the diagnosis of multiple coelomic cysts of the mediastinum.展开更多
Papilloma is a rare benign tumor. Laryngeal location is the most frequent. The bronchial involvement remains unusual. It represents 0.38% of pulmonary tumors. We report the case of a 39-year-old, smoker man, who consu...Papilloma is a rare benign tumor. Laryngeal location is the most frequent. The bronchial involvement remains unusual. It represents 0.38% of pulmonary tumors. We report the case of a 39-year-old, smoker man, who consulted for a cough following during six months with persistent radiological opacity despite antibiotic treatment. The physical examination was without particularities. Flexible bronchoscopy revealed a swollen endobronchial lesion completely obstructing the orifice of the intermediate trunk. Bronchial biopsies at this level showed inflammatory mucosa. The chest CT scan objectified an endobronchial tissular mass in the intermediate trunk. Pulmonary neoplasia was suspected. Diagnostic and therapeutic surgery was performed. Histopathological examination concluded to an endobronchial squamous papilloma.展开更多
The subcellular localization of samarium and europium, two rare-earths, increasingly used in both medical and industrial fields, has been studied in several organs such as liver and kidney but never in the mammary gla...The subcellular localization of samarium and europium, two rare-earths, increasingly used in both medical and industrial fields, has been studied in several organs such as liver and kidney but never in the mammary gland despite of its importance in the biology of lactation and nutrition domains. The intracellular behaviour of samarium and europium after their intra-peritoneal administration in the lactating mammary gland cells was investigated. The results showed the presence of very electron dense deposits in the glandular epithelial cell lysosomes. These particular lysosomes were never observed in the mammary cell lysosomes of control rats. These intralysosomal deposits were probably composed of insoluble samarium or europium phosphates by analogy with previous studies, the transmission electron microscopy, the ion mass microscopy and the electron probe microanalysis, and other techniques allowing the identification of the chemical structure of the intralysosomal deposits.展开更多
文摘Near InfraRed Spectroscopy (NIRS) has become an extremely important analytical technique in recent years and been applied in various geoscience areas such as mineral exploration and environmental studies. It is used for studying the physico-chemical properties of earth materials by enabling the interpretation of mineral composition and the study of its variability based on the diagnostic of spectral features. In this research, the application of laboratory reflectance spectroscopy in assessing heavy metals pollution is investigated. The potential use of reflectance spectroscopy in detecting Fe-related and clay minerals as well as the quantitative characterization of pollutants is studied for the mine waste of Jalta and Bougrine in the North of Tunisia. Mining activities of lead/Zn, have led to extensive pollution. The analysis of geochemical results outlined the level and spatial pattern of pollutants concentration. Results of the study showed that a relationship exists between reflectance spectra and geochemical measures of pollutants. The Spectral interpretation of Fe-related minerals and clay minerals showed that they are related to the pollutants and can be used as indirect spectral indicators of the pollution. The Fe-minerals include: jarosite, goethite, hematite/goethite, and hematite;clay minerals and feature-less (aspectral) materials. A direct quantitative relationship between pollutants and spectral parameters shows that Pb-Zn-Mn are the best correlated with a ratio of 610/500 nm range while Ni-Cr have a best correlation with a slope around 980 nm. Outputs from Partial Least Square Regression (PLSR) confirmed these relationships and also indicated that spectral parameters and reflectance values within 400 - 2500 nm range can better predict the contamination for Mn, Pb and Zn than for Ni and Cr but not for Fe, Cu, Cd, EC and pH.
文摘The tidal flat of Nakta is located in the northern part of the gulf of Gabes and in the southern coast of Sfax. It corresponds to a flat reef protected from less topography, with a slope ranging between 2° and 4°, which borders the Gargour Wadi. The study sector is renowned to have moderate hydrodynamics which lasts almost for two millenary (14C isotopic dating). The sedimentological study of the Nakta tidal flat revealed different facies: fine-grained sand in the intertidal zone and carbonated muddy sand in the infratidal zone. Equilibrium state of the Nakta ecosystem depends entirely on tide currents, which mainly inhibit drift currents. The Nakta tidal flat is characterized by a variety of faunal species (Cerastoderma glaucum, Arca noe, Cardita antiquatus, Chlamys varied, Ruditapes deccussatus, Tapes rhomboids, Pinctada radiate, etc.) and floristic diversities (Halocnemum strobilacum, Halimione portulacoides, Enteromorpha linza, Ulva rigida, Cymodocea nodosa, Posidonia oceanica). The species are abundant in the infratidal zone, while in its intertidal zone, faunal species remain little diversified and are dominated by limivorous diggering. The paleogeographic study of the Nakta tidal flat showed the alternation of regression and transgression periods.
文摘Gravity data associated with surface geology in the Northern Tunisian Atlas offer better understand to the underlying structures in Teboursouk area and to highlight other deep or unknown structures in surface. The gravity study was based on qualitative and quantitative analysis including the construction of the gravity Bouguer anomaly, upward continuations, residual anomaly, and Horizontal gradient maxima maps. The main results display many positive and negative anomalies as the response of geological structures (J. Cheid Triassic structure, Khalled plain, El Aroussa plain). In addition, the horizontal gradient maxima integrated with geological and structural maps let the identification of major directions of gravimetric lineaments in the study area us NE-SW trending features at the boundaries of J. Cheid structure, NW-SE direction that limit Gaafour plain and Tabet Ech Cherif syncline, and N-S trending that bordered El Aroussa basin. Major results allowed the construction of a new structural map of the study zone.
文摘Stream networks are considered important units in many environmental decision making processes. The extraction of streams using digital elevation models (DEMs) presents many advantages. However it is very sensitive to the uncertainty of the elevation datasets used. The main aim of this paper is to implement geostatistical simulations and assess the propagated uncertainty and map the error of location streams. First, point sampled elevations are used to fit a variogram model. Next two hundred DEM realizations are generated using conditional sequential Gaussian simulation;the stream network map is extracted for each of these realizations, and the collection of stream networks is analyzed to quantify the error propagation. At each grid cell, the probability of the occurrence of a stream and the propagated error are estimated. The more probable stream network are delineated and compared with the digital stream network derived from topographic map. The method is illustrated using a small dataset (8742 sampled elevations) for Anaguid Saharan platform. All computations are run in two free softwares: R and SAGA. R is used to fit variogram and to run sequential Gaussian simulation. SAGA is used to extract streams via RSAGA library.
文摘Hydrogen-bonded polar nematic liquid crystal series with the general formula n OBAF(n = 7-12) is studied. The mesomorphic characterization is demonstrated through differential scanning calorimetry(DSC) and polarized optical microscopy(POM). The complexes with short alkyl chains(n = 7, 8) present a wide nematic range and monotropic smectic F mesophase, whereas the longer alkyl chain(n = 10-12) analogues show high melting and low clearing mesomorphic liquid crystals. The thermal range of the mesophase and the birefringence increase with chain length decreasing. Furthermore, the effect of the nanoparticles(LiNbO_(3)) on the thermal and the electrical behavior of 8OBAF are investigated. The presence of LiNbO_(3) nanoparticles increases the conductivity and reduces the resistivity of the complex.
文摘A new cobalt diphosphate (Na0.71Ag0.29)2CoP2O7, is synthesized by solid state reaction method and characterized by single-crystal X-ray diffraction. The title material crystallizes in the triclinic space group P-1 with a = 6.4170(3) , b = 9.4510(2) , c = 10.9350(3) , a = 115.240(2)o, b = 80.190(3)o and g = 106.810(2)0. The structure presents a centro-symmetrical clusters Co4P4O28 consists of two Co2O11 units and two P2O7 pyrophosphate groups. The junction between clusters is assured by two P2O7 groups to form a three-dimensional anionic framework having different interconnecting tunnels running along [100] and [010]. The former contains the Na+ and Ag+ cations. The conductivity measurements of (Na0.71Ag0.29)2CoP2O7 are studied over a temperature interval from 783 to 903 K using the frequency response analyzer with 0.5 V amplitude signal over the range of 13 MHz - 5 Hz.
文摘Intrathoracic mesothelial cysts are congenital lesions due to an abnormal development of the pericardial coelom. They are generally unilocular and can develop in various sites. We describe a case of multicystic lesions in the anterior mediastinum of a 53-year-old woman discovered in a context of an encysted pleural effusion. Chest computed tomography (CT) scan revealed multiple cystic lesions in the anterior and posterior mediastinum. Surgery was carried out and histopathology and immunohistochemistry confirmed the diagnosis of multiple coelomic cysts of the mediastinum.
文摘Papilloma is a rare benign tumor. Laryngeal location is the most frequent. The bronchial involvement remains unusual. It represents 0.38% of pulmonary tumors. We report the case of a 39-year-old, smoker man, who consulted for a cough following during six months with persistent radiological opacity despite antibiotic treatment. The physical examination was without particularities. Flexible bronchoscopy revealed a swollen endobronchial lesion completely obstructing the orifice of the intermediate trunk. Bronchial biopsies at this level showed inflammatory mucosa. The chest CT scan objectified an endobronchial tissular mass in the intermediate trunk. Pulmonary neoplasia was suspected. Diagnostic and therapeutic surgery was performed. Histopathological examination concluded to an endobronchial squamous papilloma.
文摘The subcellular localization of samarium and europium, two rare-earths, increasingly used in both medical and industrial fields, has been studied in several organs such as liver and kidney but never in the mammary gland despite of its importance in the biology of lactation and nutrition domains. The intracellular behaviour of samarium and europium after their intra-peritoneal administration in the lactating mammary gland cells was investigated. The results showed the presence of very electron dense deposits in the glandular epithelial cell lysosomes. These particular lysosomes were never observed in the mammary cell lysosomes of control rats. These intralysosomal deposits were probably composed of insoluble samarium or europium phosphates by analogy with previous studies, the transmission electron microscopy, the ion mass microscopy and the electron probe microanalysis, and other techniques allowing the identification of the chemical structure of the intralysosomal deposits.
