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Wyszukujesz frazę "Pham, Hoa Thi" wg kryterium: Autor


Wyświetlanie 1-8 z 8
Tytuł:
A Lasso and Elastic-Net Regularized Generalized Linear Model for Predicting Blast-Induced Air Over-pressure in Open-Pit Mines
Model Lasso i uogólniony model liniowy elastycznej siatki do prognozowania nadciśnienia wywołanego wybuchem w kopalniach odkrywkowych
Autorzy:
Bui, Xuan‑Nam
Nguyen, Hoang
Tran, Quang Hieu
Bui, Hoang‑Bac
Nguyen, Quoc Long
Nguyen, Dinh An
Le, Thi Thu Hoa
Pham, Van Viet
Powiązania:
https://bibliotekanauki.pl/articles/318532.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
Lasso model
kopalnia odkrywkowa
wybuchy
open pit mines
explosives
Opis:
Air overpressure (AOp) is one of the products of blasting operations in open-pit mines which have a great impact on the environment and public health. It can be dangerous for the lungs, brain, hearing and the other human senses. In addition, the impact on the surrounding environment such as the vibration of buildings, break the glass door systems are also dangerous agents caused by AOp. Therefore, it should be properly controlled and forecasted to minimize the impacts on the environment and public health. In this paper, a Lasso and Elastic-Net Regularized Generalized Linear Model (GLMNET) was developed for predicting blast-induced AOp. The United States Bureau of Mines (USBM) empirical technique was also applied to estimate blast-induced AOp and compare with the developed GLMNET model. Nui Beo open-pit coal mine, Vietnam was selected as a case study. The performance indices are used to evaluate the performance of the models, including Root Mean Square Error (RMSE), Determination Coefficient (R2), and Mean Absolute Error (MAE). For this aim, 108 blasting events were investigated with the Maximum of explosive charge capacity, monitoring distance, powder factor, burden, and the length of stemming were considered as input variables for predicting AOp. As a result, a robust GLMNET model was found for predicting blast-induced AOp with an RMSE of 1.663, R2 of 0.975, and MAE of 1.413 on testing datasets. Whereas, the USBM empirical method only reached an RMSE of 2.982, R2 of 0.838, and MAE of 2.162 on testing datasets.
Źródło:
Inżynieria Mineralna; 2019, 21, 2/2; 8-20
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Chlorinated benzenes and benzene degradation in aerobic pyrite suspension
Autorzy:
Pham, Hoa Thi
Chihiro, Inoue
Powiązania:
https://bibliotekanauki.pl/articles/205353.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
benzene
degradation
pyrite
aerobic
chlorinated benzene
Opis:
The focus of this study is to investigate the applicability of natural mineral iron disulfide (pyrite) in degradation of aromatic compounds including benzene and several chlorinated benzenes (from mono-chlorinated benzene (CB), di-chlorinated benzenes (di-CBs) to tri-chlorobenzenes (tri-CBs) in aerobic pyrite suspension by using laboratory batch experiments at 25°C and room pressure. At first, chlorobenzene was studied as a model compound for all considered aromatic compounds. CB was degraded in aerobic pyrite suspension, transformed to several organic acids and finally to CO2 and Clˉ. Transformations of remaining aromatic compounds were pursued by measuring their degradation rates and CO2 and Clˉ released with time. Transformation kinetics was fitted to the pseudo-first-order reactions to calculate degradation rate constant of each compound. Degradation rates of the aromatic compounds were different depending on their chemical structures, specifically the number and position of chlorine substituents on the benzene ring in this study. Compounds with the highest number of chlorine substituent at m-positions have highest degradation rate (1,3,5-triCB > 1,3-diCB > others). Three chlorine substituents closed together (1,2,3-triCB) generated steric hindrance effects. Therefore 1,2,3-triCB was the least degraded compound The degradation rates of all compounds were in the following order: 1,3,5-triCB > 1,3-diCB > 1,2,4-triCB ≅1,2-diCB ≅CB ≅benzene > 1,4-diCB > 1,2,3-triCB. The final products of the transformations were CO2 and Clˉ. Oxygen was the common oxidant for pyrite and aromatic compounds. The presence of aromatic compounds reduced the oxidation rate of pyrite, which reduced the amount of ferrous and sulfate ions release to aqueous solution.
Źródło:
Archives of Environmental Protection; 2019, 45, 1; 115-125
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determining for an output capacity of dimension stone exploitation from the computer simulations to generate the fracture network in 3D: case study in some dimensional stone quarries in Vietnam
Określenie wydajności wykorzystania kamienia blocznego z symulacji komputerowych w celu wygenerowania sieci pęknięć w 3D: studium przypadku w kamieniołomach kamieni blocznych w Wietnamie
Autorzy:
Nguyen, Anh Tuan
Pham, Van Hoa
Pham, Van Viet
Le, Van Quyen
Le, Thi Hai
Nguyen, Tuan Anh
Powiązania:
https://bibliotekanauki.pl/articles/318207.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
kamieniołomy
Wietnam
symulacja komputerowa
quarries
Vietnam
computer simulation
Opis:
In dimension stone quarry exploitations such as the marble quarry, a literature review of the existing numerical modelling techniques has been carried out. According to Distinct Element Method, discontinuities have been treated as boundary conditions between blocks and, consequently, an accurate knowledge of joint distribution and orientation was required. The result of analyzing data and simulating in the fracture rock environment, which is applied to a mining condition of the dimensional stone quarries. The research we introduce in the output capacity of the dimension stone quarry from the computer simulations to generate the fracture network in 3D with an aim of evaluating the size of the blocks. The results of numerical models have been used to optimize some of the technical parameters for dimensional stone extraction and ensuring stable bench in the mining operation.
Źródło:
Inżynieria Mineralna; 2019, 21, 2/2; 135-146
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of truck-shovel dispatching in Cao Son Open-Pit coal mine and the ability in applying information technology for increasing its efficiency
Oszacowanie wywozu ładowarkami w kopalni odkrywkowej Cao Son i możliwości zastosowania technologii informatycznych w celu zwiększenia wydajności
Autorzy:
Pham, Van Hoa
Bui, Xuan‑Nam
Le, Van Quyen
Le, Thi Thu Hoa
Pham, Van Viet
Powiązania:
https://bibliotekanauki.pl/articles/317977.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
kopalnie odkrywkowe
wywóz
Wietnam
efektywność
open pit mines
dispatching
Vietnam
efficiency
Opis:
With many types of trucks and shovels for hauling large volume of waste rocks to the dump sites and coal to the storages, the truck – shovel dispatching in Cao Son open pit coal mine is the operation which needs to be improved. At present, the combination between trucks and shovel is usually assigned at the beginning of shift and adjusted during the operation at the mine. The GPS tracking system are integrated into each truck to monitor the position in real time, but applying this information to find the best destination to send the truck to satisfy the production requirements and to minimize truck operating costs is still not used. This paper presents the estimation of the information system, data, the remaining problems of truck – shovel dispatching system, from that proposes the application of available information technology for increasing the efficiency of this activities at the mine.
Źródło:
Inżynieria Mineralna; 2019, 21, 2/2; 21-27
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of Nitramine Explosives in Aqueous Solution by UV-Mediated Advanced Oxidation Process in Near-Neutral Conditions
Autorzy:
Khue, Do Ngoc
Bach, Vu Quang
Binh, Nguyen Thanh
Minh, Do Binh
Nam, Pham Thi
Loi, Vu Duc
Nguyen, Hoa Thanh
Powiązania:
https://bibliotekanauki.pl/articles/1838360.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
hexogen
octogen
tetryl
UV
photo-Fenton
electrooxidation
near neutral
Opis:
Explosive compounds are hazardous to the environment, posing a serious risk to human and animal health and the ecosystem. The primary goal of research was to compare the efficiency of UV/H2O2, photo-Fenton, electro (EO)/ UV/H2O2 processes at near-neutral pH (pH=6) on the degradation of nitramine explosives (NAs), such as hexogen (RDX), octogen (HMX), and tetryl (TET), in an aqueous solution. The effect of operational conditions, likely pH of the solution, initial H2O2 concentration, initial Fe2+ concentration, and solution temperature, was observed. The removal kinetics fit with first-order kinetics and were in the order: photo-Fenton >EO/UV/ H2O2 > UV/ H2O2. The results showed higher rate constant values for TET, RDX and HMX removal by UV/ H2O2 (k = 0.07778, 0.03791 and 0.03786 min-1), EO/UV/ H2O2 (k = 0.16599, 0.1475 and 0.08674 min-1) and photo-Fenton (k = 0.18018, 0.1501 and 0.09336 min-1) processes. Furthermore, TET, RDX and HMX were mineralized at 59.7%, 45.1%, and 25.1 %, respectively, under optimum conditions after 60 min of the photo-Fenton process. From the economic perspective, photo-Fenton only requires 2.132–4.113 kWh m-3 to completely reduce NAs. Finally, acute toxicity towards Vibrio fischeri was defeated after usage of near-neutral photo-Fenton. Thus, photo-Fenton at circum-neutral is promising for low-cost, eco-friendly and efficient processes for treating nitramine explosives in aqueous solutions.
Źródło:
Journal of Ecological Engineering; 2021, 22, 6; 232-243
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of Nitramine Explosives in Aqueous Solution by UV-Mediated Advanced Oxidation Process in Near-Neutral Conditions
Autorzy:
Khue, Do Ngoc
Bach, Vu Quang
Binh, Nguyen Thanh
Minh, Do Binh
Nam, Pham Thi
Loi, Vu Duc
Nguyen, Hoa Thanh
Powiązania:
https://bibliotekanauki.pl/articles/1838333.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
hexogen
octogen
tetryl
UV
photo-Fenton
electrooxidation
near neutral
Opis:
Explosive compounds are hazardous to the environment, posing a serious risk to human and animal health and the ecosystem. The primary goal of research was to compare the efficiency of UV/H2O2, photo-Fenton, electro (EO)/ UV/H2O2 processes at near-neutral pH (pH=6) on the degradation of nitramine explosives (NAs), such as hexogen (RDX), octogen (HMX), and tetryl (TET), in an aqueous solution. The effect of operational conditions, likely pH of the solution, initial H2O2 concentration, initial Fe2+ concentration, and solution temperature, was observed. The removal kinetics fit with first-order kinetics and were in the order: photo-Fenton >EO/UV/ H2O2 > UV/ H2O2. The results showed higher rate constant values for TET, RDX and HMX removal by UV/ H2O2 (k = 0.07778, 0.03791 and 0.03786 min-1), EO/UV/ H2O2 (k = 0.16599, 0.1475 and 0.08674 min-1) and photo-Fenton (k = 0.18018, 0.1501 and 0.09336 min-1) processes. Furthermore, TET, RDX and HMX were mineralized at 59.7%, 45.1%, and 25.1 %, respectively, under optimum conditions after 60 min of the photo-Fenton process. From the economic perspective, photo-Fenton only requires 2.132–4.113 kWh m-3 to completely reduce NAs. Finally, acute toxicity towards Vibrio fischeri was defeated after usage of near-neutral photo-Fenton. Thus, photo-Fenton at circum-neutral is promising for low-cost, eco-friendly and efficient processes for treating nitramine explosives in aqueous solutions.
Źródło:
Journal of Ecological Engineering; 2021, 22, 6; 232-243
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation of FLY-ROCK DISTANCe as a Function of Blast Conditions: a Case Study in Vietnam
Symulacja odległości między odrzucającymi skałami jako funkcją warunkową techniki strzelniczej: studium przypadku w Wietnamie
Autorzy:
Nguyen, Anh Tuan
Pham, Van Hoa
Pham, Van Viet
Tran, Dinh Bao
Le, Thi Hai
Powiązania:
https://bibliotekanauki.pl/articles/318683.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
quarry
blasting
fly-rock distance
non-smooth discrete element method (NSCD)
simulation
kamieniołom
technika strzelnicza
odrzucające skały
metoda elementów dyskretnych nie-gładkich (NSCD)
symulacja
Opis:
The prediction of fly-rock distances is a big problem in the blasting areas of open-pit mines. The fly-rock distance plays a crucial role in the reduction and control of blasting accidents in quarries. This paper proposes the modelling of the contact dynamics as a non-smooth discrete element method (NSCD). Then, the fly-rock phenomenon is simulated using this NSCD method. This approach was to develop a model that correlates to blast conditions, initial fly-rock/rock-fall velocities and permits the computation of fly-rock range from randomization orbits. The results showed that the NSCD method is a good means for the simulation with the variability of blasting parameters. This method is to relate the initial fly-rock velocity to blast conditions and then uses ballistic trajectories to compute the maximum fly-rock distance. Finally, it should be noted that the proposed simulation of fly-rock trajectories which shows the distribution of fly-rock bounce heights above the ground level with the different coefficient of restitution range as a function of blast conditions. It should be used in the Ninh Dan limestone quarry belonging to the Song Thao Cement, Phu Tho province (Vietnam), and it should be directly used in the same other quarries.
Przewidywanie odległości między odrzucającymi skałami ma duży problem w kopalniach odkrywkowych. Odległość między skałami odrzucającymi odgrywa niezwykłą rolę w ograniczaniu i kontrolowaniu wypadków spowodowanych robotami strzelniczymi w kamieniołomach. W artykule, zaproponowano modelowanie dynamiki kontaktu jako metodę elementów dyskretnych Non-Smooth (NSCD). Następnie symuluje się zjawisko fly-rock metodą NSCD. Zastosowane podejście polegało na opracowaniu modelu, który kore-luje warunki wybuchów, początkowe prędkości lotnych skał i pozwala na obliczenie zasięgu fali z orbity losowej. Wyniki pokazały, że NSCD jest dobrym środkiem do symulacji przy zmienności parametrów strzałów. Ta metoda zastosowana w niniejszych badaniach polega na powiązaniu początkowej prędkości latających skał z warunkami wybuchu, a następnie wykorzystaniu trajektorii balistycznych do obliczenia maksymalnej odległości między latającymi skałami. Na koniec należy zauważyć, że zaproponowano symulację trajektorii odrzucających skał, która pokazuje rozkłady wysokości odbijania skał nad poziomem ziemi przy różnym współczynniku zakresu restytucji w funkcji warunków techniki strzelniczej. Powinien być stosowany w kamieniołomie wapienia Ninh Dan należącym do cementu Song Thao w prowincji Phu Tho (Wietnam) i powinien być stosowany w podobnych kamieniołomach.
Źródło:
Inżynieria Mineralna; 2020, 1, 2; 275-282
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Strategy in Dispatching Trucks and Shovels with Different Capacity to Increase the Operating Efficiency in Cao Son Surface Coal Mine, Vietnam
Autorzy:
Pham, Van Hoa
Tran, Trung Chuyen
Le, Hong Anh
Le, Thi Thu Hoa
Pham, Van Viet
Nguyen, Anh Tuan
Le, Thi Huong Giang
Powiązania:
https://bibliotekanauki.pl/articles/2020238.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
truck dispatching
truck-shovel system
dispatching strategy
detailed match factor
górnictwo odkrywkowe
Wietnam
strategia
Opis:
In surface mining operations, the operating costs of truck-shovel system constitutes 50-60% of the total. Only a little save in the operation costs in this system will bring large profit for the mines. Due to many investment periods, the capacity of both trucks and shovels in Cao Son surface coal mine is different. This leads to the low efficiency and the difficulty in dispatching strategy for the mine. This paper presents the current situation and selection of advanced dispatching strategy for increasing the efficiency trucks and shovels at this surface coal mine. The results show the detailed match factor reflects the state of each team of loader and trucks and should be use as the indicator for dispatching decision for the heterogeneous truck and shovel fleet at Cao Son surface coal mine.
Źródło:
Inżynieria Mineralna; 2021, 2; 487--494
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-8 z 8

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