Pub Date : 2022-06-30DOI: 10.46326/jmes.2022.63(3).04
H. T. T. Tran, H. Tran
Activated carbons (ACs) are well known as the most commonly used adsorbent in water and wastewater treatment. They have many advantage characteristics such as high surface area, large pores and diverse surface functional groups with the high stability of chemical, mechanical and thermal. The aims of this study are to fabricate and evaluate the ability to remove the azo dye Chrysoidine Y in the water of three activated carbon materials from bamboo leaves, including AC30 (6500C/30 minutes); AC45 (6500C/45 minutes) and AC60 (6500C/60 minutes). The material characteristics determined by SEM, EDX, FTIR and BET methods, etc. showed that all three samples had high C content (over 72%) and appeared functional groups with the capacity of removing azo dye as C = C; C - O - C, O - H. The FTIR results indicated that three samples have adsorption spectra from 400÷4000 cm-1 with characteristic bonds such as C = O, O - H, C - C, C = C. When 20 ml of a solution containing 0.25; 0.5; 1 and 2 g of AC30, AC45 and AC60 materials were added the azo dye volume varied from 2, 3, 4 and 5 ml of Chrysoidine Y, the lowest and highest adsorption capacity were recorded of 133.64 and 361.2 mg/g, respectively. With the highest BET surface area up to 108,9202 m2/g, the AC60 material sample achieved a maximum efficiency of 100% at a reaction time of 30 minutes with a Chysoidine dye/distilled water volume ratio of 2/18 (ml), pH 9, adsorbent content of 0.25 g. The results also showed that the activated carbon from bamboo leaves is a potential sorbent material in removing the azo dye in water.
活性炭(ACs)是水和废水处理中最常用的吸附剂。它们具有比表面积大、孔隙大、表面官能团多样等优点，具有较高的化学、机械和热稳定性。本研究的目的是制备并评价三种竹叶活性炭材料的去除水中偶氮染料Chrysoidine Y的能力，包括AC30 (6500C/30分钟);AC45 (6500C/45分钟)和AC60 (6500C/60分钟)。通过SEM、EDX、FTIR、BET等方法对材料进行表征，结果表明，三种样品均具有较高的C含量(大于72%)，且出现了去除偶氮染料能力为C = C的官能团;C - O - C, O - H。FTIR结果表明，3种样品的吸附光谱从400÷4000 cm-1开始，具有C = O, O - H, C - C, C = C等特征键。0.5;在偶氮染料体积为2、3、4和5 ml的情况下，分别加入1和2 g AC30、AC45和AC60材料，记录的最低和最高吸附量分别为133.64和361.2 mg/g。AC60材料样品在乳酸碱染料/蒸馏水体积比为2/18 (ml)， pH为9，吸附剂含量为0.25 g的条件下，反应时间为30 min，效率达到100%，BET表面积最高可达108,9202 m2/g。竹叶活性炭是去除水中偶氮染料的一种有潜力的吸附材料。
{"title":"Evaluate to remove azo dye Chrysoidine Y of activated carbon material produced from bamboo leaves","authors":"H. T. T. Tran, H. Tran","doi":"10.46326/jmes.2022.63(3).04","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(3).04","url":null,"abstract":"Activated carbons (ACs) are well known as the most commonly used adsorbent in water and wastewater treatment. They have many advantage characteristics such as high surface area, large pores and diverse surface functional groups with the high stability of chemical, mechanical and thermal. The aims of this study are to fabricate and evaluate the ability to remove the azo dye Chrysoidine Y in the water of three activated carbon materials from bamboo leaves, including AC30 (6500C/30 minutes); AC45 (6500C/45 minutes) and AC60 (6500C/60 minutes). The material characteristics determined by SEM, EDX, FTIR and BET methods, etc. showed that all three samples had high C content (over 72%) and appeared functional groups with the capacity of removing azo dye as C = C; C - O - C, O - H. The FTIR results indicated that three samples have adsorption spectra from 400÷4000 cm-1 with characteristic bonds such as C = O, O - H, C - C, C = C. When 20 ml of a solution containing 0.25; 0.5; 1 and 2 g of AC30, AC45 and AC60 materials were added the azo dye volume varied from 2, 3, 4 and 5 ml of Chrysoidine Y, the lowest and highest adsorption capacity were recorded of 133.64 and 361.2 mg/g, respectively. With the highest BET surface area up to 108,9202 m2/g, the AC60 material sample achieved a maximum efficiency of 100% at a reaction time of 30 minutes with a Chysoidine dye/distilled water volume ratio of 2/18 (ml), pH 9, adsorbent content of 0.25 g. The results also showed that the activated carbon from bamboo leaves is a potential sorbent material in removing the azo dye in water.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"189 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124183373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.46326/jmes.2022.63(3).10
Hung Tien Nguyen, Duong Vu, Toan Huu To, Nhung Tuyet Thi Nguyen
In petroleum industry, the prediction of oil production flow rate plays an important role in tracking the good performance as well as maintaining production flow rate. In addition, a flow rate modelling with high accuracy will be useful in optimizing production properties to achieve the expected flow rate, enhance oil recovery factor and ensure economic efficiency. However, the oil production flow rate is traditionally predicted by theoretical or empirical models. The theoretical model usually gives predicted results with a wide variation of error, this model also requires a lot of input data that might be time-consuming and costly. The empirical models are often limited by the volume of data set used to construct the model, therefore predicted values from the applications of these models in practical condition are not highly accurate. In this research, the authors propose the use of an artificial neural network (ANN) to establish a better relationship between production properties and oil production flow rate and predict oil production flow rate. Using production data of 5 wells which use continuous gas lift method in X oil field, Vietnam, an ANN system was developed by using back-propagation algorithm and tansig function to predict production flow rate from the above data set. This ANN system is called a back-propagation neural network (BPNN). In comparison with the oil production flow rate data collected from these studied continuous gas lift oil wells, the predicted results from the constructed ANN achieved a very high correlation coefficient (98%) and low root mean square error (33.41 bbl/d). Therefore, the developed ANN models can serve as a practical and robust tool for oilfield prediction of production flow rate.
{"title":"Application of artificial neural network for predicting production flow rates of gaslift oil wells","authors":"Hung Tien Nguyen, Duong Vu, Toan Huu To, Nhung Tuyet Thi Nguyen","doi":"10.46326/jmes.2022.63(3).10","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(3).10","url":null,"abstract":"In petroleum industry, the prediction of oil production flow rate plays an important role in tracking the good performance as well as maintaining production flow rate. In addition, a flow rate modelling with high accuracy will be useful in optimizing production properties to achieve the expected flow rate, enhance oil recovery factor and ensure economic efficiency. However, the oil production flow rate is traditionally predicted by theoretical or empirical models. The theoretical model usually gives predicted results with a wide variation of error, this model also requires a lot of input data that might be time-consuming and costly. The empirical models are often limited by the volume of data set used to construct the model, therefore predicted values from the applications of these models in practical condition are not highly accurate. In this research, the authors propose the use of an artificial neural network (ANN) to establish a better relationship between production properties and oil production flow rate and predict oil production flow rate. Using production data of 5 wells which use continuous gas lift method in X oil field, Vietnam, an ANN system was developed by using back-propagation algorithm and tansig function to predict production flow rate from the above data set. This ANN system is called a back-propagation neural network (BPNN). In comparison with the oil production flow rate data collected from these studied continuous gas lift oil wells, the predicted results from the constructed ANN achieved a very high correlation coefficient (98%) and low root mean square error (33.41 bbl/d). Therefore, the developed ANN models can serve as a practical and robust tool for oilfield prediction of production flow rate.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114013313","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.46326/jmes.2022.63(3).02
T. Vu, Thanh Thi Nguyen
This paper studies the water quality degradation of Sat river - the section flowing through Hai Duong province and waste sources pollute Sat river water. Five surveyed locations along Sat River were identified, and water samples were taken for five consecutive years from 2016 to 2020. Water samples were analyzed in the laboratory with the criteria and methods regulated by QCVN 08:2015/BTNMT. The analyzed results showed that the Sat river water had five parameters frequently exceeding the B1 limit value of QCVN 08 - MT: 2015 BTNMT consisting of DO, NH4+, PO43 -, COD, and BOD5. Two main causes of Sat river pollution conclude of pollutants available in the river upstream and from many sources of domestic wastewater, industrial wastewater, and agricultural wastewater in Hai Duong province without proper treatment. To improve the water quality of Sat river, the collection and treatment of wastes at the source must be thoroughly treated with reasonable waste management.
{"title":"Water quality degradation in Sat River - the section flowing through Hai Duong province and some proposals to improve river water quality","authors":"T. Vu, Thanh Thi Nguyen","doi":"10.46326/jmes.2022.63(3).02","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(3).02","url":null,"abstract":"This paper studies the water quality degradation of Sat river - the section flowing through Hai Duong province and waste sources pollute Sat river water. Five surveyed locations along Sat River were identified, and water samples were taken for five consecutive years from 2016 to 2020. Water samples were analyzed in the laboratory with the criteria and methods regulated by QCVN 08:2015/BTNMT. The analyzed results showed that the Sat river water had five parameters frequently exceeding the B1 limit value of QCVN 08 - MT: 2015 BTNMT consisting of DO, NH4+, PO43 -, COD, and BOD5. Two main causes of Sat river pollution conclude of pollutants available in the river upstream and from many sources of domestic wastewater, industrial wastewater, and agricultural wastewater in Hai Duong province without proper treatment. To improve the water quality of Sat river, the collection and treatment of wastes at the source must be thoroughly treated with reasonable waste management.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124712068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-30DOI: 10.46326/jmes.2022.63(2).10
L. Le
Competitiveness plays an important role in the efficiency and productivity of the Economic zone. The research analyzed the current state of competitiveness of Nghi Son economic zone, Thanh Hoa province, by means of analysis, synthesis, statistics and comparison based on the data source of Nghi Son economic zone management board. After screening and processing, the following results are obtained: (i) Competition at the enterprise level: foreign-invested enterprises act in a small number of projects but account for 73.68 of total investment capital. The number of assembly, processing and processing projects in the economic zone accounts for a large proportion, of which petrochemical and chemical industry projects take two-thirds of the registered capital, lack of the presence of other industries; (ii) Competition at the local level: Infrastructure investment projects are mobilized from central capital and socialized to build relatively synchronous and complete hard and soft infrastructure; living environment and investment support services to meet practical needs. (iii); Availability factors in the economic zone: the favorable geographical location and abundant natural resources are the factors that create the competitiveness of the economic zone. However, the problem of Nghi Son Economic Zone is that there are still some limitations that need to be overcome to improve competitiveness in the coming time.
{"title":"Research on competitiveness of Nghi Son Economic Zone in Thanh Hoa and some raised issues","authors":"L. Le","doi":"10.46326/jmes.2022.63(2).10","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(2).10","url":null,"abstract":"Competitiveness plays an important role in the efficiency and productivity of the Economic zone. The research analyzed the current state of competitiveness of Nghi Son economic zone, Thanh Hoa province, by means of analysis, synthesis, statistics and comparison based on the data source of Nghi Son economic zone management board. After screening and processing, the following results are obtained: (i) Competition at the enterprise level: foreign-invested enterprises act in a small number of projects but account for 73.68 of total investment capital. The number of assembly, processing and processing projects in the economic zone accounts for a large proportion, of which petrochemical and chemical industry projects take two-thirds of the registered capital, lack of the presence of other industries; (ii) Competition at the local level: Infrastructure investment projects are mobilized from central capital and socialized to build relatively synchronous and complete hard and soft infrastructure; living environment and investment support services to meet practical needs. (iii); Availability factors in the economic zone: the favorable geographical location and abundant natural resources are the factors that create the competitiveness of the economic zone. However, the problem of Nghi Son Economic Zone is that there are still some limitations that need to be overcome to improve competitiveness in the coming time.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127971415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-30DOI: 10.46326/jmes.2022.63(2).08
Anh Cam Thi Kim, Giang Truong Nguyen, S. T. Nguyen, Q. Nguyen
Where the danger of electric shock is high, for example underground mines or medical equipment directly connected to a patient, special ungrounded power systems (unearthed networks) may be used to minimize possible leakage current to the ground. In mixed unearthed networks (AC/DC-IT) comprising alternating and direct current circuits, AC part of system is connected with DC part through rectifyer valves. Commutation of the valves causes cyclic variation of configuration of the entire galvanically connected network. A distinct feature of AC/DC-IT systems is that voltages between all points of AC side and ground may have mean value different from zero. This characteristic parameter can be used as a signal to determine fault and position to ground or decrease in insulation resistance. However, it also affects the results of the network equivalent insulation resistance measurements when a DC source is used to check insulation. The paper presents a solution to eliminate this effect and proposes a device model to measure and monitor insulation resistance. The results of this study can be applied in the design and manufacture of automatic resistance measuring and monitoring devices for AC/DC mixed unearthed networks.
{"title":"Measurement and automatic monitoring insulation resistance of AC/DC mixed unearthed networks","authors":"Anh Cam Thi Kim, Giang Truong Nguyen, S. T. Nguyen, Q. Nguyen","doi":"10.46326/jmes.2022.63(2).08","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(2).08","url":null,"abstract":"Where the danger of electric shock is high, for example underground mines or medical equipment directly connected to a patient, special ungrounded power systems (unearthed networks) may be used to minimize possible leakage current to the ground. In mixed unearthed networks (AC/DC-IT) comprising alternating and direct current circuits, AC part of system is connected with DC part through rectifyer valves. Commutation of the valves causes cyclic variation of configuration of the entire galvanically connected network. A distinct feature of AC/DC-IT systems is that voltages between all points of AC side and ground may have mean value different from zero. This characteristic parameter can be used as a signal to determine fault and position to ground or decrease in insulation resistance. However, it also affects the results of the network equivalent insulation resistance measurements when a DC source is used to check insulation. The paper presents a solution to eliminate this effect and proposes a device model to measure and monitor insulation resistance. The results of this study can be applied in the design and manufacture of automatic resistance measuring and monitoring devices for AC/DC mixed unearthed networks.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133751709","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-30DOI: 10.46326/jmes.2022.63(2).03
P. Nguyen, Huan Dinh Trinh, Giang Truong Nguyen, Chau Le Tran
This paper presents new results about evaluating the exploration's reliability and Uranium reserve calculation of the Binh Duong deposit, Cao Bang province, by using the multiple math statistical and geostatistics methods. The results indicte: - The Uranium ore bodies in the Binh Duong deposit are lenticular-shaped, complex morphology and structure. They belong to the small-scale type, with complex changes. - The Uranium contents of industrial ore bodies calculated by the ore thickness’ weighted average method are comparable to those estimated by the adjacent bulk method. However, these values are systematically lower than the mean values. - The crucial factor in the reliability of the exploration and calculation for reserves in the Binh Duong Uranium deposit are the ore bodies’ thickness and random error in sample analysis. - The error in calculating uranium reserves in the case of taking into account the efficiency of using the internally and externally extrapolating boundaries of the ore body are larger than the case without paying attention to this efficiency. - The exploration network has been carried out being within 40m along the strike and 20÷40 m along the slope, enough basis to calculate reserves at level 122; however, out of this network only responds to the requirement of calculating resource at level 333.
{"title":"Evaluating the reliability of the exploration and calculating Uranium reserves of the Binh Duong Deposit, Cao Bang province","authors":"P. Nguyen, Huan Dinh Trinh, Giang Truong Nguyen, Chau Le Tran","doi":"10.46326/jmes.2022.63(2).03","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(2).03","url":null,"abstract":"This paper presents new results about evaluating the exploration's reliability and Uranium reserve calculation of the Binh Duong deposit, Cao Bang province, by using the multiple math statistical and geostatistics methods. The results indicte:\u0000- The Uranium ore bodies in the Binh Duong deposit are lenticular-shaped, complex morphology and structure. They belong to the small-scale type, with complex changes. \u0000- The Uranium contents of industrial ore bodies calculated by the ore thickness’ weighted average method are comparable to those estimated by the adjacent bulk method. However, these values are systematically lower than the mean values. \u0000- The crucial factor in the reliability of the exploration and calculation for reserves in the Binh Duong Uranium deposit are the ore bodies’ thickness and random error in sample analysis. \u0000- The error in calculating uranium reserves in the case of taking into account the efficiency of using the internally and externally extrapolating boundaries of the ore body are larger than the case without paying attention to this efficiency.\u0000- The exploration network has been carried out being within 40m along the strike and 20÷40 m along the slope, enough basis to calculate reserves at level 122; however, out of this network only responds to the requirement of calculating resource at level 333.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"273 1-2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132070807","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-30DOI: 10.46326/jmes.2022.63(2).09
Tan Nguyen, Thu Quoc Tran
Hydraulic drive systems are commonly used in many different industrial sections. In the underground mining industry, in addition to ensuring transmission for big equipment, hydraulic equipment also must be fire safety. During the working process, the hydraulic oil gets hot and the viscosity decreases, it make the transmission power decrease. Due to the harsh actual working conditions of hydraulic equipment such as high working intensity, high working environment temperature, the oil cooler cannot cool the hydraulic oil to the required temperature. In order to choose the right type of oil cooler for hydraulic actuators, it is necessary to calculate the working parameters of the oil cooler according to specific working conditions. Currently, the selection of hydraulic oil coolers is often based on the experience of the designer, so it can lead to errors. In order to increase the reliability of the hydraulic oil cooler, this paper has built a calculation formula based on the thermodynamic theory and the heat transfer characteristic graphs in the catalogs of the hydraulic oil cooler. At the same time, the paper made an illustrative example for the selection of the hydraulic oil cooler of the JKYB hydraulic explosion-proof hoist used at Duong Huy coal company.
{"title":"Research, calculation and selection of hydraulic oil water cooler for JKYB hydraulic explosion-proof hoist used at Duong Huy coal company","authors":"Tan Nguyen, Thu Quoc Tran","doi":"10.46326/jmes.2022.63(2).09","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(2).09","url":null,"abstract":"Hydraulic drive systems are commonly used in many different industrial sections. In the underground mining industry, in addition to ensuring transmission for big equipment, hydraulic equipment also must be fire safety. During the working process, the hydraulic oil gets hot and the viscosity decreases, it make the transmission power decrease. Due to the harsh actual working conditions of hydraulic equipment such as high working intensity, high working environment temperature, the oil cooler cannot cool the hydraulic oil to the required temperature. In order to choose the right type of oil cooler for hydraulic actuators, it is necessary to calculate the working parameters of the oil cooler according to specific working conditions. Currently, the selection of hydraulic oil coolers is often based on the experience of the designer, so it can lead to errors. In order to increase the reliability of the hydraulic oil cooler, this paper has built a calculation formula based on the thermodynamic theory and the heat transfer characteristic graphs in the catalogs of the hydraulic oil cooler. At the same time, the paper made an illustrative example for the selection of the hydraulic oil cooler of the JKYB hydraulic explosion-proof hoist used at Duong Huy coal company.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126257284","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-30DOI: 10.46326/jmes.2022.63(2).06
N. T. Pham, Fuzhou Qi
For the coal mine tunnel, each type of cross-section of the tunnel will cause different laws of mechanical change in the rock mass around the tunnel. This difference is expressed through quantities such as displacement, stress, the damage zones within rock mass, etc.. It is completely unreasonable to adopt an independent mechanical parameter to evaluate the selection of the most optimal shape for the tunnel. To simulate the tunnel excavation process with different types of cross-section shapes in the same geological conditions, the software FLAC3D was employed. The data extracted from numerical simulation including displacement, stress field, plastic deformation area, the thickness of plastic deformation zone at the top, side, and bottom of the tunnel are evaluated. The type of section shape with the highest score will be evaluated as the most optimal one. The present case study shows that the type of cross-sectional shape of the straight wall with curved arch and deviated trapezoid got the highest scores of 36 points and 30 points, respectively. Therefore, the type of cross-sectional shape of the straight wall with curved arch and deviated trapezoid should be used. This shape choice will be the most optimal, and beneficial to the stability of the tunnel both during excavation and production progress.
{"title":"Application of the numerical method to analyze the effect of cross-sectional type in stabilizing the coal mine tunnel","authors":"N. T. Pham, Fuzhou Qi","doi":"10.46326/jmes.2022.63(2).06","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(2).06","url":null,"abstract":"For the coal mine tunnel, each type of cross-section of the tunnel will cause different laws of mechanical change in the rock mass around the tunnel. This difference is expressed through quantities such as displacement, stress, the damage zones within rock mass, etc.. It is completely unreasonable to adopt an independent mechanical parameter to evaluate the selection of the most optimal shape for the tunnel. To simulate the tunnel excavation process with different types of cross-section shapes in the same geological conditions, the software FLAC3D was employed. The data extracted from numerical simulation including displacement, stress field, plastic deformation area, the thickness of plastic deformation zone at the top, side, and bottom of the tunnel are evaluated. The type of section shape with the highest score will be evaluated as the most optimal one. The present case study shows that the type of cross-sectional shape of the straight wall with curved arch and deviated trapezoid got the highest scores of 36 points and 30 points, respectively. Therefore, the type of cross-sectional shape of the straight wall with curved arch and deviated trapezoid should be used. This shape choice will be the most optimal, and beneficial to the stability of the tunnel both during excavation and production progress.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"88 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132520597","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-30DOI: 10.46326/jmes.2022.63(2).01
Minh Quang Nguyen, Phi Quoc Nguyen, Phamchimai Phan, H. Nguyen
The study area is heavily affected by landslides with increasing frequency and intensity, causing serious damages and affecting the sustainable socio-economic development of the region. The use of mathematical methods in landslide research is increasingly interested due to the quantitative nature of parameters and calculation results. This study aims to apply the Certainty Factor (CF) and Bayesian statistics models for geological hazard evaluation. Landslide distribution is identified from remote sensing images and field surveys. Landslide inventory maps (428 landslides) were compiled by reference to historical reports, Google Earth, and field mapping. All landslides were randomly separated into two data sets: 70% were used to establish the models (training data sets) and the rest for validation (validation data sets). Fifteen environmental factors from geology, topography and hydrological information of the studied area were extracted from the spatial database. Results show that the group of factors of slope angle, Terrain Ruggedness Index, fault/lineament density, stratigraphy, geoengineering characteristics, weathering types, and maximum daily rainfall play the most important role in the formation of landslides in the study area. Validation from Certainty Factor (CF) and Bayesian statistics models show 87% and 92% prediction accuracy between hazard maps and existing landslide locations. These models show reasonably accurate landslide predictions in the study area and can be served as the basis of landslide risk-management studies in the future.
{"title":"Application of Certainty Factor and Bayesian statistics models for evaluation of landslides and environmental factors at Bao Thang district and Lao Cai city, Lao Cai province","authors":"Minh Quang Nguyen, Phi Quoc Nguyen, Phamchimai Phan, H. Nguyen","doi":"10.46326/jmes.2022.63(2).01","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(2).01","url":null,"abstract":"The study area is heavily affected by landslides with increasing frequency and intensity, causing serious damages and affecting the sustainable socio-economic development of the region. The use of mathematical methods in landslide research is increasingly interested due to the quantitative nature of parameters and calculation results. This study aims to apply the Certainty Factor (CF) and Bayesian statistics models for geological hazard evaluation. Landslide distribution is identified from remote sensing images and field surveys. Landslide inventory maps (428 landslides) were compiled by reference to historical reports, Google Earth, and field mapping. All landslides were randomly separated into two data sets: 70% were used to establish the models (training data sets) and the rest for validation (validation data sets). Fifteen environmental factors from geology, topography and hydrological information of the studied area were extracted from the spatial database. Results show that the group of factors of slope angle, Terrain Ruggedness Index, fault/lineament density, stratigraphy, geoengineering characteristics, weathering types, and maximum daily rainfall play the most important role in the formation of landslides in the study area. Validation from Certainty Factor (CF) and Bayesian statistics models show 87% and 92% prediction accuracy between hazard maps and existing landslide locations. These models show reasonably accurate landslide predictions in the study area and can be served as the basis of landslide risk-management studies in the future.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"100 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125071862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-04-30DOI: 10.46326/jmes.2022.63(2).07
N. Bui, A. Le, Muoi Nguyen, H. M. Nguyen
Hydrocarbon production forecasting for the field lifetime in the short and long term is an important phase, the accuracy of this process plays a tremendous role in giving the decision of reasonable field management and development. In this article, the logistic growth models using the function MATLAB’s ‘nlinfit’ have been built to forecast oil production yield for the Oligocene C sequence, X field, Cuu Long basin. Thanks to the combination with the history matching process, the logistic growth model expressed high accuracy, the results of the model are very close to the actual production data with a relative error of 1,85%. The article analyzed and evaluated the production parameters of wells obtained when building logistic growth models such as the time at which half of the carrying capacity has been produced, the steepness of the decline of the rate, and the production rate of the wells at the forecast time. Without applying any improved oil recovery method, the decline of the rate of all wells approaches 100 bbl/d before reaching the validity period of the oil and gas contract. This is the basis for operators to establish and improve field development plans.
{"title":"Forecasting oil production for Oligocene C sequence, X field, Cuu Long basin using logistic growth model","authors":"N. Bui, A. Le, Muoi Nguyen, H. M. Nguyen","doi":"10.46326/jmes.2022.63(2).07","DOIUrl":"https://doi.org/10.46326/jmes.2022.63(2).07","url":null,"abstract":"Hydrocarbon production forecasting for the field lifetime in the short and long term is an important phase, the accuracy of this process plays a tremendous role in giving the decision of reasonable field management and development. In this article, the logistic growth models using the function MATLAB’s ‘nlinfit’ have been built to forecast oil production yield for the Oligocene C sequence, X field, Cuu Long basin. Thanks to the combination with the history matching process, the logistic growth model expressed high accuracy, the results of the model are very close to the actual production data with a relative error of 1,85%. The article analyzed and evaluated the production parameters of wells obtained when building logistic growth models such as the time at which half of the carrying capacity has been produced, the steepness of the decline of the rate, and the production rate of the wells at the forecast time. Without applying any improved oil recovery method, the decline of the rate of all wells approaches 100 bbl/d before reaching the validity period of the oil and gas contract. This is the basis for operators to establish and improve field development plans.","PeriodicalId":170167,"journal":{"name":"Journal of Mining and Earth Sciences","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-04-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130146402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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