Uniaxial compressive strength (UCS) represents one of the key mechanical properties used to characterize rocks along with the other important properties of porosity and density. While several studies have proved the accuracy of artificial intelligence in modeling UCS, some authors believe that the use of artificial intelligence is not practical in predicting. The present paper highlights the ability of an artificial neural network (ANN) as an accurate and revolutionary method with regression models, as a conventional statistical analysis, to predict UCS within carbonate rocks and mortar. Thus, ANN and multiple linear regressions (MLR) were applied to estimate the UCS values of the tested samples. For experimentation we carried out ultrasonic measurements on cubic samples before testing uniaxial compressive strength perpendicularly to the stress direction. The models were performed to correlate effective porosity, density and ultrasonic velocity to the UCS measurements. The resulting models would allow the prediction of carbonate rocks and mortar’s UCS values usually determined by laborious experiments. Although the results demonstrate the usefulness of the MLP method as a simple, practical and economical model, the ANN model is more accurate. ARTICLE INFO
{"title":"Prediction of uniaxial compressive strength of carbonate rocks and cement mortar using artificial neural network and multiple linear regressions","authors":"M. Abdelhedi","doi":"10.13168/agg.2020.0027","DOIUrl":"https://doi.org/10.13168/agg.2020.0027","url":null,"abstract":"Uniaxial compressive strength (UCS) represents one of the key mechanical properties used to characterize rocks along with the other important properties of porosity and density. While several studies have proved the accuracy of artificial intelligence in modeling UCS, some authors believe that the use of artificial intelligence is not practical in predicting. The present paper highlights the ability of an artificial neural network (ANN) as an accurate and revolutionary method with regression models, as a conventional statistical analysis, to predict UCS within carbonate rocks and mortar. Thus, ANN and multiple linear regressions (MLR) were applied to estimate the UCS values of the tested samples. For experimentation we carried out ultrasonic measurements on cubic samples before testing uniaxial compressive strength perpendicularly to the stress direction. The models were performed to correlate effective porosity, density and ultrasonic velocity to the UCS measurements. The resulting models would allow the prediction of carbonate rocks and mortar’s UCS values usually determined by laborious experiments. Although the results demonstrate the usefulness of the MLP method as a simple, practical and economical model, the ANN model is more accurate. ARTICLE INFO","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"367-377"},"PeriodicalIF":0.9,"publicationDate":"2020-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42320676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The Noorabad ophiolite is part of Kermanshah ophiolites in NW of Lorestan province, west Iran. The Kermanshah ophiolite complex with NW-SE trending is located in the SSW of the main Zagros thrust fault within the high Zagros zone. Rocks of the Noorabad ophiolite include diabases dikes, basalts lava and andesite that outcropped in the south of the Noorabad. These rocks are intensly altered and fractured that led to hydrothermal alteration and replacement of primary minerals such as pyroxene, plagioclase and opaque minerals by secondary minerals. Based on geochemical studies, the rocks of this area have tholeiitic and calc-alkaline signature. Also the plotted rock samples in geochemical discrimination diagrams, occur in island arc basalt (IAB) field. These rocks show depletion in HREE and HFSE and also are enriched in LILE and LREE. These patterns suggest that these rocks formed in intra-oceanic subduction zone. These geochemical characteristics along with comparison with other ophiolitic rocks in east Mediterranean reveal a subduction zone environment for genesis of the intermediate and mafic rocks of the Noorabad ophiolite. ARTICLE INFO
{"title":"Petrology and Geochemistry of Noor abad ophiolite (Lorestan province, west Iran): an evidence of intra-oceanic subduction","authors":"M. Kiani","doi":"10.13168/agg.2020.0026","DOIUrl":"https://doi.org/10.13168/agg.2020.0026","url":null,"abstract":"The Noorabad ophiolite is part of Kermanshah ophiolites in NW of Lorestan province, west Iran. The Kermanshah ophiolite complex with NW-SE trending is located in the SSW of the main Zagros thrust fault within the high Zagros zone. Rocks of the Noorabad ophiolite include diabases dikes, basalts lava and andesite that outcropped in the south of the Noorabad. These rocks are intensly altered and fractured that led to hydrothermal alteration and replacement of primary minerals such as pyroxene, plagioclase and opaque minerals by secondary minerals. Based on geochemical studies, the rocks of this area have tholeiitic and calc-alkaline signature. Also the plotted rock samples in geochemical discrimination diagrams, occur in island arc basalt (IAB) field. These rocks show depletion in HREE and HFSE and also are enriched in LILE and LREE. These patterns suggest that these rocks formed in intra-oceanic subduction zone. These geochemical characteristics along with comparison with other ophiolitic rocks in east Mediterranean reveal a subduction zone environment for genesis of the intermediate and mafic rocks of the Noorabad ophiolite. ARTICLE INFO","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"353-365"},"PeriodicalIF":0.9,"publicationDate":"2020-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43828732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The surface displacement caused by hydrological loading makes an important contribution to the non-linear crustal movement observed at the International Global Navigation Satellite System Service (IGS) stations. In this paper, the amplitude, correlation, and root mean square (RMS) of the vertical displacement time series signals of 47 IGS stations are used to analyze which data of Gravity Recovery and Climate Experiment (GRACE) or Global Land Data Assimilation System (GLDAS) can better reflect the hydrological load effect in Europe. The results show that in Europe, the hydrological load effect calculated based on GRACE data is more accurate than that of GLDAS, which has not been reported before. Then, the relationship between the GPS height and GRACE load deformation in terms of annually-oscillating signals, correlation, and phase is analyzed by using singular spectrum analysis, the Pearson correlation coefficient, and wavelet coherence (WTC). It was found that GPS and GRACE agree at some stations (e.g., BOR1 and ZIMM), while they differ significantly in amplitude and phase at other stations (e.g., KIRU and NOT1), indicating that not all GRACE-derived displacements of IGS stations can clearly explain their nonlinear motion. The correlation coefficients between GPS and GRACE are higher than 0.7 at 85 % of stations. Amongst them, the values are obviously greater than 0.8 (e.g., ZIMM and LAMA) around inland areas and high mountains, and even less than 0.6 (e.g., ANKR and KIRU) along the coast of the Mediterranean ocean, which more precisely shows that the hydrological load effect has obvious spatial and regional characteristics compared with previous studies. In addition, the relative phase of the WTC solution is basically consistent under non-detrend and detrend, which shows that the relative phase difference of each station is only related to the nonlinear movement and not to the linear trend caused by the tectonic deformation. Finally, we study the influence of GRACE hydrological load on the RMS of GPS height, which is reduced by 24.60 % on average, and the reduction rate distribution of the RMS is in good agreement with the spatial distribution of the correlation coefficient. ARTICLE INFO
{"title":"Comparisons of GRACE and GLDAS derived hydrological loading and the impacts on the GPS time series in Europe","authors":"Yankai Bian","doi":"10.13168/agg.2020.0022","DOIUrl":"https://doi.org/10.13168/agg.2020.0022","url":null,"abstract":"The surface displacement caused by hydrological loading makes an important contribution to the non-linear crustal movement observed at the International Global Navigation Satellite System Service (IGS) stations. In this paper, the amplitude, correlation, and root mean square (RMS) of the vertical displacement time series signals of 47 IGS stations are used to analyze which data of Gravity Recovery and Climate Experiment (GRACE) or Global Land Data Assimilation System (GLDAS) can better reflect the hydrological load effect in Europe. The results show that in Europe, the hydrological load effect calculated based on GRACE data is more accurate than that of GLDAS, which has not been reported before. Then, the relationship between the GPS height and GRACE load deformation in terms of annually-oscillating signals, correlation, and phase is analyzed by using singular spectrum analysis, the Pearson correlation coefficient, and wavelet coherence (WTC). It was found that GPS and GRACE agree at some stations (e.g., BOR1 and ZIMM), while they differ significantly in amplitude and phase at other stations (e.g., KIRU and NOT1), indicating that not all GRACE-derived displacements of IGS stations can clearly explain their nonlinear motion. The correlation coefficients between GPS and GRACE are higher than 0.7 at 85 % of stations. Amongst them, the values are obviously greater than 0.8 (e.g., ZIMM and LAMA) around inland areas and high mountains, and even less than 0.6 (e.g., ANKR and KIRU) along the coast of the Mediterranean ocean, which more precisely shows that the hydrological load effect has obvious spatial and regional characteristics compared with previous studies. In addition, the relative phase of the WTC solution is basically consistent under non-detrend and detrend, which shows that the relative phase difference of each station is only related to the nonlinear movement and not to the linear trend caused by the tectonic deformation. Finally, we study the influence of GRACE hydrological load on the RMS of GPS height, which is reduced by 24.60 % on average, and the reduction rate distribution of the RMS is in good agreement with the spatial distribution of the correlation coefficient. ARTICLE INFO","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"297-310"},"PeriodicalIF":0.9,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45293404","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study presents the results of in-situ field stabilization of clay soil using lime, dolerite and quartzite powders. The rock samples were collected from Oghi village and Misri Banda village of Khyber Pakhtunkhwa Province, Pakistan. A 415m2 site comprised of loose clay in Haripur district of Khyber Pakhtunkhwa was selected for field stabilization. In order to implement the experimental plan, eight test pits were dug and soil samples were collected from each pit to determine their major geotechnical properties. The raw soil contained kaolinite, illite and montmorillonite and hence characterized as CH type according to the Unified Classification System. The addition of 6 % lime was found to produce the most positive impact on soil properties. Following a steady augment by 10 %, a maximum of 30 % dolerite and quartzite powders were separately mixed with each of the 6 % lime-added soil samples. The resulting mixed soils were placed back into their respective pits and compacted using compaction vibrator. Standard penetration, field density and plate load tests were performed on each test pit. Finally, soil samples were extracted from all the test pits and the values of their direct shear box and Atterberg limits were measured. The results demonstrate that the addition of dolerite and quartzite leads to a significant increase in the bearing capacity, dry density, penetration resistance and angle of internal friction and thus improves the performance of the formerly lime-stabilized soil by drastically decreasing its compressibility. The resulting improvement is mainly due to the denser and less hydrophilic character of the constituents of the added rock powders as compared with the lime and raw soil. It has also been found that the magnitude of impact on the soil properties by dolerite and quartzite is notably different owing to the difference in mineralogical composition and physical characteristics of individual minerals present in both rock types. This study would help construction engineers for better soil treatment. ARTICLE INFO
{"title":"In-situ stabilization of clays with lime, dolerite and quartzite powders","authors":"S. A. Shah","doi":"10.13168/agg.2020.0025","DOIUrl":"https://doi.org/10.13168/agg.2020.0025","url":null,"abstract":"This study presents the results of in-situ field stabilization of clay soil using lime, dolerite and quartzite powders. The rock samples were collected from Oghi village and Misri Banda village of Khyber Pakhtunkhwa Province, Pakistan. A 415m2 site comprised of loose clay in Haripur district of Khyber Pakhtunkhwa was selected for field stabilization. In order to implement the experimental plan, eight test pits were dug and soil samples were collected from each pit to determine their major geotechnical properties. The raw soil contained kaolinite, illite and montmorillonite and hence characterized as CH type according to the Unified Classification System. The addition of 6 % lime was found to produce the most positive impact on soil properties. Following a steady augment by 10 %, a maximum of 30 % dolerite and quartzite powders were separately mixed with each of the 6 % lime-added soil samples. The resulting mixed soils were placed back into their respective pits and compacted using compaction vibrator. Standard penetration, field density and plate load tests were performed on each test pit. Finally, soil samples were extracted from all the test pits and the values of their direct shear box and Atterberg limits were measured. The results demonstrate that the addition of dolerite and quartzite leads to a significant increase in the bearing capacity, dry density, penetration resistance and angle of internal friction and thus improves the performance of the formerly lime-stabilized soil by drastically decreasing its compressibility. The resulting improvement is mainly due to the denser and less hydrophilic character of the constituents of the added rock powders as compared with the lime and raw soil. It has also been found that the magnitude of impact on the soil properties by dolerite and quartzite is notably different owing to the difference in mineralogical composition and physical characteristics of individual minerals present in both rock types. This study would help construction engineers for better soil treatment. ARTICLE INFO","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"341-352"},"PeriodicalIF":0.9,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42935097","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many of the known Tertiary porphyry Cu deposits (PCDs) are situated in the Central Iranian Volcanic Belt (CIVB). The study area is located in the southern part of the CIVB and southern part of the Kerman Cenozoic magmatic arc. This research highlights the significance of the synergetic use of operational land imager aboard the Landsat-8 (OLI), Sentinel-2, and advanced space-borne thermal emission and reflection radiometer (ASTER) data for exploration of copper mineralization in a mine scale. Multispectral images in the visible and near infrared bands of (0.451.0 μm) the OLI and Sentinel-2 were used to identify the gossan zones. ASTER short wave infrared (SWIR) data with the wavelength between 1.65 and 2.43 μm were used for mapping hydrothermal alteration zones. Laboratory spectra obtained from minerals such as muscovite and illite (phyllic alteration), kaolinite and montmorillonite (argillic alteration), epidote and chlorite (propylitic alteration) were applied in mixture tuned matched filtering (MTMF) algorithm on the ASTER data to enhance the existence of these minerals. The spectra of the index minerals from each alteration type were used in this algorithm and the abundances of minerals in the MTMF image were rescaled to be within the ranges of 34-54 %, 54-74 % and 74-100 %. The studied mineralized zone is associated with the iron rich phyllic and argillic hydrothermal alteration types which can be best detected by using integrated ASTER, OLI, and Sentinel-2 images. The diamond drill cores data also indicate that copper is more enriched below the gossan zones. The gossan index minerals (GIM) including goethite, jarosite, and hematite were identified by X-ray diffraction (XRD) method, spectral analyses, and petrographic examinations. The Sentinel -2 data proved to provide remarkably better mapping result for iron oxide minerals than the OLI and ASTER data. The directed principal component analysis (DPCA) method, In the data of the Landsat-8 and Sentinel2 were used for mapping of the gossan index minerals such as goethite, jarosite and hematite and the argillic, phyllic and propylitic hydrothermal alteration types were enhanced using the MTMF methods. The hydrothermal alteration pattern and the distribution of the gossans in the study area show a porphyry-type mineralization. This study showed that the synergetic use of different satellite images with different spatial and spectral resolutions can be used for mineral exploration in a large scale. The use of laboratory spectra obtained from hydrothermal alteration minerals in MTMF method depicts that the alteration minerals were mapped more accurately relative to those MTMF images that are derived from standard spectral libraries. The samples collected from the surficial hydrothermal alteration zones as well as diamond drill cores showed that the copper mineralization occurres mainly along the border of the phyllic and argillic alteration zones, and the magnetite mineralization in the propylitic
{"title":"Synergetic use of the Sentinel-2, ASTER, and Landsat-8 data for hydrothermal alteration and iron oxide minerals mapping in a mine scale","authors":"M. Khaleghi","doi":"10.13168/agg.2020.0023","DOIUrl":"https://doi.org/10.13168/agg.2020.0023","url":null,"abstract":"Many of the known Tertiary porphyry Cu deposits (PCDs) are situated in the Central Iranian Volcanic Belt (CIVB). The study area is located in the southern part of the CIVB and southern part of the Kerman Cenozoic magmatic arc. This research highlights the significance of the synergetic use of operational land imager aboard the Landsat-8 (OLI), Sentinel-2, and advanced space-borne thermal emission and reflection radiometer (ASTER) data for exploration of copper mineralization in a mine scale. Multispectral images in the visible and near infrared bands of (0.451.0 μm) the OLI and Sentinel-2 were used to identify the gossan zones. ASTER short wave infrared (SWIR) data with the wavelength between 1.65 and 2.43 μm were used for mapping hydrothermal alteration zones. Laboratory spectra obtained from minerals such as muscovite and illite (phyllic alteration), kaolinite and montmorillonite (argillic alteration), epidote and chlorite (propylitic alteration) were applied in mixture tuned matched filtering (MTMF) algorithm on the ASTER data to enhance the existence of these minerals. The spectra of the index minerals from each alteration type were used in this algorithm and the abundances of minerals in the MTMF image were rescaled to be within the ranges of 34-54 %, 54-74 % and 74-100 %. The studied mineralized zone is associated with the iron rich phyllic and argillic hydrothermal alteration types which can be best detected by using integrated ASTER, OLI, and Sentinel-2 images. The diamond drill cores data also indicate that copper is more enriched below the gossan zones. The gossan index minerals (GIM) including goethite, jarosite, and hematite were identified by X-ray diffraction (XRD) method, spectral analyses, and petrographic examinations. The Sentinel -2 data proved to provide remarkably better mapping result for iron oxide minerals than the OLI and ASTER data. The directed principal component analysis (DPCA) method, In the data of the Landsat-8 and Sentinel2 were used for mapping of the gossan index minerals such as goethite, jarosite and hematite and the argillic, phyllic and propylitic hydrothermal alteration types were enhanced using the MTMF methods. The hydrothermal alteration pattern and the distribution of the gossans in the study area show a porphyry-type mineralization. This study showed that the synergetic use of different satellite images with different spatial and spectral resolutions can be used for mineral exploration in a large scale. The use of laboratory spectra obtained from hydrothermal alteration minerals in MTMF method depicts that the alteration minerals were mapped more accurately relative to those MTMF images that are derived from standard spectral libraries. The samples collected from the surficial hydrothermal alteration zones as well as diamond drill cores showed that the copper mineralization occurres mainly along the border of the phyllic and argillic alteration zones, and the magnetite mineralization in the propylitic ","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"311-328"},"PeriodicalIF":0.9,"publicationDate":"2020-08-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42252546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Volumetric studies of mica spatial distribution inside samples of Westerly and Czech granites (Mrakotin, Liberec, and Brno syenite) were performed using a neutron tomography method. A significant difference in the neutron attenuation coefficients of mica and other rock-forming minerals of the granites studied yielded a large neutron radiography contrast and, as a result, allowed us to perform a detailed analysis of three-dimension structural data based on the neutron tomography reconstruction procedure. The morphology and spatial distribution of the mica phase within studied granites were obtained. Tomography data were compared to results provided by other experimental methods commonly used in rock mechanics research such as optical and electron microscopy, as well as ultrasonic shear-wave measurements. The benefits and limitations for application of the neutron tomography method for studies of granite like rocks are discussed. ARTICLE INFO
{"title":"Contribution of neutron tomography to 3D heterogeneity analysis of granitic rocks","authors":"I. Zel","doi":"10.13168/agg.2020.0019","DOIUrl":"https://doi.org/10.13168/agg.2020.0019","url":null,"abstract":"Volumetric studies of mica spatial distribution inside samples of Westerly and Czech granites (Mrakotin, Liberec, and Brno syenite) were performed using a neutron tomography method. A significant difference in the neutron attenuation coefficients of mica and other rock-forming minerals of the granites studied yielded a large neutron radiography contrast and, as a result, allowed us to perform a detailed analysis of three-dimension structural data based on the neutron tomography reconstruction procedure. The morphology and spatial distribution of the mica phase within studied granites were obtained. Tomography data were compared to results provided by other experimental methods commonly used in rock mechanics research such as optical and electron microscopy, as well as ultrasonic shear-wave measurements. The benefits and limitations for application of the neutron tomography method for studies of granite like rocks are discussed. ARTICLE INFO","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"259-267"},"PeriodicalIF":0.9,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43378432","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the adsorption performance of montmorillonite (MMT) was evaluated by Basic Red- 5 adsorption experiments considering the influencing factors (initial BR-5 concentration, dosage, time, pH, and temperature). The surface and structural properties were characterized by FT-IR, XRD, XRF, SEM-EDS, AFM, and BET techniques. The adsorption experiments were carried out by batch mode for the evaluation of isotherm, kinetic, and thermodynamic studies. The results of equilibrium adsorption isotherm were interpreted using different isotherm models. The equilibrium data fitted well with the Langmuir isotherm models, and the maximum adsorption capacity was found as 163.93 mg/g. Adsorption data of the BR-5 onto MMT provide well by pseudo-second-order model (R 2 = 0.999). The Δ H o , Δ S o and Δ G o values were calculated for the nature of the adsorption process. The analysis of the thermodynamic parameters showed spontaneous, exothermic, and viable adsorption of BR-5 under the investigated experimental conditions. A factorial design was applied to examine the effect of three factors initial concentration of dye (50 and 100 mg/L), time (60 and 120 min.) and dosage (0.05 and 1.00 mg/L) on the adsorption process. According to the results, with high efficient adsorption capacity and compatible surface properties are advantageous to be used for uptake of dyes.
本研究通过碱性红-5吸附实验，考察了BR-5的初始浓度、投加量、时间、pH、温度等因素对蒙脱土(MMT)吸附性能的影响。采用FT-IR、XRD、XRF、SEM-EDS、AFM和BET等技术对其表面和结构性能进行了表征。吸附实验采用批处理模式进行等温线、动力学和热力学研究。用不同的等温线模型解释了平衡吸附等温线的结果。平衡数据符合Langmuir等温线模型，最大吸附量为163.93 mg/g。BR-5在MMT上的吸附数据符合拟二阶模型(r2 = 0.999)。根据吸附过程的性质计算了Δ H o、Δ S o和Δ G o值。热力学参数分析表明，在实验条件下，BR-5具有自发吸附、放热吸附和活吸附。采用因子设计考察染料初始浓度(50和100 mg/L)、时间(60和120 min)和投加量(0.05和1.00 mg/L)对吸附过程的影响。结果表明，其高效吸附能力和相容的表面性能有利于染料的吸附。
{"title":"Basic RED-5 adsorption on montmorillonite: faktorial design, equilibrium, kinetic and thermodynamic studies","authors":"Feza Geyicki","doi":"10.13168/agg.2020.0020","DOIUrl":"https://doi.org/10.13168/agg.2020.0020","url":null,"abstract":"In this study, the adsorption performance of montmorillonite (MMT) was evaluated by Basic Red- 5 adsorption experiments considering the influencing factors (initial BR-5 concentration, dosage, time, pH, and temperature). The surface and structural properties were characterized by FT-IR, XRD, XRF, SEM-EDS, AFM, and BET techniques. The adsorption experiments were carried out by batch mode for the evaluation of isotherm, kinetic, and thermodynamic studies. The results of equilibrium adsorption isotherm were interpreted using different isotherm models. The equilibrium data fitted well with the Langmuir isotherm models, and the maximum adsorption capacity was found as 163.93 mg/g. Adsorption data of the BR-5 onto MMT provide well by pseudo-second-order model (R 2 = 0.999). The Δ H o , Δ S o and Δ G o values were calculated for the nature of the adsorption process. The analysis of the thermodynamic parameters showed spontaneous, exothermic, and viable adsorption of BR-5 under the investigated experimental conditions. A factorial design was applied to examine the effect of three factors initial concentration of dye (50 and 100 mg/L), time (60 and 120 min.) and dosage (0.05 and 1.00 mg/L) on the adsorption process. According to the results, with high efficient adsorption capacity and compatible surface properties are advantageous to be used for uptake of dyes.","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"66268242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Assessment of rockfall hazard of hill slope along Mumbai-Pune Expressway, Maharashtra. India","authors":"L. K. Sharma","doi":"10.13168/agg.2020.0021","DOIUrl":"https://doi.org/10.13168/agg.2020.0021","url":null,"abstract":"","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"285-296"},"PeriodicalIF":0.9,"publicationDate":"2020-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47138552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Fluorite mineralization is controlled by the multiple geological processes such as structural control, geochemical characterization of hydrothermal fluids, temperature and depth. The mineralization associated with the alteration of the host rocks and trapping of fluid in the host rock crystallographic defects. Alteration in the host rocks due to circulation of hydrothermal fluids and several techniques were applied to discriminate the associated alterations in fluorite deposition using the ASTER images. The resulting images indicated that the fluorite mineralization in the studied area accompanied by propylitic and phyllic alterations. The results of micro-thermometry analysis of the fluorite hosted fluid inclusions indicated that the maximum homogenization temperature was 253 °C. These data implies that the temperature of hydrothermal fluids probably had an essential role in the propagation of the alteration zones. The depth versus homogenization temperature diagram for fluorite mineralization in the studied district revealed that the depth of fluorite mineralization varies between 33 to 256 m. Two fluorite generations were distinguishing in the study district. The first generation is characterized by high salinity (18-25 wt.% NaCl) which developed on the deeper level and along the fault zone. The second generation is characterized by low salinity (6-13 wt.% NaCl) on shallow depth and deposited in the fractures. The results revealed that fluorite deposition was not contemporaneous with host rock deformation and deposited in the late-stage deformation phase. ARTICLE INFO
{"title":"The role of the structures on the fluorite mineralization: Insight to fluid inclusion and alteration map of the Laal-kan fluorite deposit, NW Iran","authors":"M. Behyari","doi":"10.13168/agg.2020.0028","DOIUrl":"https://doi.org/10.13168/agg.2020.0028","url":null,"abstract":"Fluorite mineralization is controlled by the multiple geological processes such as structural control, geochemical characterization of hydrothermal fluids, temperature and depth. The mineralization associated with the alteration of the host rocks and trapping of fluid in the host rock crystallographic defects. Alteration in the host rocks due to circulation of hydrothermal fluids and several techniques were applied to discriminate the associated alterations in fluorite deposition using the ASTER images. The resulting images indicated that the fluorite mineralization in the studied area accompanied by propylitic and phyllic alterations. The results of micro-thermometry analysis of the fluorite hosted fluid inclusions indicated that the maximum homogenization temperature was 253 °C. These data implies that the temperature of hydrothermal fluids probably had an essential role in the propagation of the alteration zones. The depth versus homogenization temperature diagram for fluorite mineralization in the studied district revealed that the depth of fluorite mineralization varies between 33 to 256 m. Two fluorite generations were distinguishing in the study district. The first generation is characterized by high salinity (18-25 wt.% NaCl) which developed on the deeper level and along the fault zone. The second generation is characterized by low salinity (6-13 wt.% NaCl) on shallow depth and deposited in the fractures. The results revealed that fluorite deposition was not contemporaneous with host rock deformation and deposited in the late-stage deformation phase. ARTICLE INFO","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":"1 1","pages":"379-390"},"PeriodicalIF":0.9,"publicationDate":"2020-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45023518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Precise Point Positioning (PPP) has been considered a powerful method for GNSS data processing. The essential input products, such as precise satellite orbits and clocks, are provided within the International GNSS Service (IGS) with a sufficient quality for estimating receiver coordinates with centimeter level accuracy. However, the IGS satellite clocks enable users to estimate ambiguities only as float values. An additional product for satellite phase biases is necessary for an integer ambiguity resolution (PPP AR). Another approach is the backward smoothing algorithm utilizing already precise and converged parameters for improving those parameters estimated at previous epochs. All the three approaches for ambiguity estimation are compared and assessed in terms of advantages and disadvantages, achieved coordinates precision, and flexibility. The comparison are performed through a processing of GNSS data from selected IGS permanent stations during 30 days in 2018, and a processing of high rate GNSS observations of the station STRF in Greece collected during the seismic event occurred on October 25, 2018. The backward smoothing improved the float solution similarly like the PPP AR, and therefore can be considered an alternative approach providing easier implementation and no dependency on additional satellites
{"title":"Comparison and assessment of float, fixed, and smoothed precise point positioning","authors":"P. Václavovic","doi":"10.13168/agg.2020.0024","DOIUrl":"https://doi.org/10.13168/agg.2020.0024","url":null,"abstract":"Precise Point Positioning (PPP) has been considered a powerful method for GNSS data processing. The essential input products, such as precise satellite orbits and clocks, are provided within the International GNSS Service (IGS) with a sufficient quality for estimating receiver coordinates with centimeter level accuracy. However, the IGS satellite clocks enable users to estimate ambiguities only as float values. An additional product for satellite phase biases is necessary for an integer ambiguity resolution (PPP AR). Another approach is the backward smoothing algorithm utilizing already precise and converged parameters for improving those parameters estimated at previous epochs. All the three approaches for ambiguity estimation are compared and assessed in terms of advantages and disadvantages, achieved coordinates precision, and flexibility. The comparison are performed through a processing of GNSS data from selected IGS permanent stations during 30 days in 2018, and a processing of high rate GNSS observations of the station STRF in Greece collected during the seismic event occurred on October 25, 2018. The backward smoothing improved the float solution similarly like the PPP AR, and therefore can be considered an alternative approach providing easier implementation and no dependency on additional satellites","PeriodicalId":50899,"journal":{"name":"Acta Geodynamica et Geomaterialia","volume":" ","pages":""},"PeriodicalIF":0.9,"publicationDate":"2020-07-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44957567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：