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Tytuł:
Virtual MRTD – an indirect method to measure MRTD of thermal imagers using computer simulation
Autorzy:
Chrzanowski, Krzysztof
Hong Viet, Nguyen
Powiązania:
https://bibliotekanauki.pl/articles/1835813.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
MRTD
minimum resolvable temperature difference
virtual MRTD
indirect method
computer simulation
thermal imager
Opis:
Minimum resolvable temperature difference (MRTD) is considered as the most important parameter of thermal imagers. A new method of MRTD measurement without drawbacks of other methods is presented in this paper. Proposed MRTD measurement method coded as virtual MRTD is based on a three steps measurement concept using semi-automatic objective measurements and computer simulation. First, objective parameters of the tested thermal imager are measured. Second, software simulates this tested thermal imager and generates the image of 4-bar target of specified spatial frequency (size) and contrast (temperature difference). Third, a human observer analyses the images of the 4-bar target generated by the software on the screen of PC set and measures MRTD of the simulated thermal imager at specified set of spatial frequencies. The proposed method offers higher measurement speed, lower cost and typically better accuracy in comparison with the typical MRTD measurement method.
Źródło:
Optica Applicata; 2020, 50, 4; 671-688
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Vietnam’s meat import market under Impacts of the European -Vietnam Free Trade Agreement and quality management demand
Autorzy:
Minh, Nguyen Doan
Viet, Nga Le Thi
Huy, Dinh Tran Ngoc
Powiązania:
https://bibliotekanauki.pl/articles/1818278.pdf
Data publikacji:
2021
Wydawca:
Uniwersytet Zielonogórski. Wydział Ekonomii i Zarządzania
Tematy:
EVFTA
Vietnam
EU
meat import
SMART
FTA
quality management
Wietnam
UE
import mięsa
zarządzanie jakością
Opis:
The impact of Free Trade Agreement (FTA) on commercial business of the member could be assessed by the potential and tangible effects. This paper is adopted by Partial equilibrium theory and SMART tool to measure the impact of EVFTA on the Vietnamese meat import (HS code 02). The result of this model is claimed that EVFTA has a huge impact on boosting the meat import from EU to Vietnam. However, the value of import in this category from European nations in each country and good fluctuated significantly. This study also proposes some measures for domestic businesses and the government to ensure the benefits on Vietnam’s livestock industry. Last but not least, meat quality management is one of vital issues under EFVTA and global competitiveness to meet higher expectation of consumers. Good food (meat) manufacturing practices need to be applied. That is the social contribution value of this paper.
Źródło:
Management; 2021, 25, 1; 99-117
1429-9321
2299-193X
Pojawia się w:
Management
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Variation in Root Development Response of Napier Grass to Drought Stress
Autorzy:
Nguyen, Loc Van
Tran, Ngoc Minh Thi
Nguyen, Long Viet
Phan, Hong Nhung Thi
Rumanzi, Mbaraka Saidi
Pham, Cuong Van
Tang, Hanh Thi
Powiązania:
https://bibliotekanauki.pl/articles/1955525.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
drought level
Napier grass
root response
root length
Opis:
Global climate change and increasing agricultural activity are the main causes of biotic and abiotic stresses, which negatively affect the plant growth and crop yields. The plant root system is the first organ for sensing the soil moisture limitation; therefore root growth under elevated water deficit is an important indicator for plant’s drought tolerance. Although the previous studies focused on the morphological traits of Napier grasses under water stresses, the root growth changes due to drought levels remain largely unclear. In order to evaluate variation in root performance to respond to drought stress, four cultivars named "Cỏ voi thuần" (CVT), King grass, Packchong, and VA06 were grown for 10 days under drought conditions under polyethylene glycol 6000 (PEG6000): 0% PEG6000 as control, 5% PEG6000, 10% PEG6000, 15% PEG6000 and 20% PEG6000. As compared to control, the root growth of all cultivars was reduced under drought treatments; however, significant variation in the root development response to drought levels was found. Among Napier cultivars, "Cỏ voi thuần" expressed drought-tolerant genotypes. The information on the root length, diameter, surface area and volume of the cultivars reveals interesting guidelines for further studies to explore the mechanisms behind root adaptation of Napier grasses to drought.
Źródło:
Journal of Ecological Engineering; 2021, 22, 8; 64-74
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Utility of GSMap Precipitation and Point Scale in Gauge Measurements for Stream Flow Modelling – A Case Study in Lam River Basin, Vietnam
Autorzy:
Kha, Dang Dinh
Nhu, Nguyen Y.
Long, Vu Viet
Van, Dao Thi Hong
Powiązania:
https://bibliotekanauki.pl/articles/123552.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
GSMaP
SWAT model
merging
Lam river basin
flow modelling
Opis:
The benefit from integrating the information from multi-source was confirmed in the research of hydrologic processes in river basins. However, the use of satellite-based rainfall products in hydrologic stream flow modeling has been limited because of the perceived uncertainty associated with such data. In this study the authors presented the simulated streamflow from a SWAT model driven by merging rainfall between satellite and gauge-observed rainfall for the Lam River Basin. The results demonstrate the usefulness of merging rainfall data for stream flow modelling at a monthly time step.
Źródło:
Journal of Ecological Engineering; 2020, 21, 2; 39-45
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of Unmanned Aerial Vehicles for 3D topographic Mapping and Monitoring the Air Quality of Open-pit Mines
Wykorzystanie bezzałogowych statków powietrznych (dronów) do monitorowania jakości powietrza w odkrywkowych kopalniach węgla kamiennego
Autorzy:
Bui, Xuan‑Nam
Lee, Changwoo
Nguyen, Quoc Long
Adeel, Ahmad
Cao, Xuan Cuong
Nguyen, Viet Nghia
Le, Van Canh
Nguyen, Hoang
Le, Qui Thao
Duong, Thuy Huong
Nguyen, Van Duc
Powiązania:
https://bibliotekanauki.pl/articles/317913.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
drony
jakość powietrza
kopalnie odkrywkowe
unmanned aerial vehicles
air quality
open pit mines
Opis:
Recently remarkable advancement development of unmanned aerial vehicles (UAVs) has been observed and their applications have been shown in many fields such as agriculture, industry, and environmental management. However, in the mining industry, the application of UAV technology remains potential. This paper presents a low-cost unmanned aerial vehicle technology-based system for 3D mapping and air quality monitoring at open-pit mine sites in Vietnam. The system includes several dust sensors that are mounted on a low-cost rotary-wing type UAV. The system collects a variety of data, mainly images and airborne pollutant concentrations. To evaluate the performance of the proposed system, field tests were carried out at the Coc Sau coal mine. Based on the images transmitted to the ground monitoring station, large scale 3D topographic maps were successfully modeled. In addition, sensors mounted on the UAV system were able to monitor the levels of environmental variables associated with the air quality within the pit such as temperature, dust, CO, CO2, and NOx. The field test results in this study illustrate the applicability of the low-cost UAV for the 3D mapping and the air quality monitoring at large and deep coal pits with relatively high accuracy.
Źródło:
Inżynieria Mineralna; 2019, 21, 2/2; 223-239
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Use of Cashew Apple Pomace Powder in Pasta Making: Effects of Powder Ratio on the Product Quality
Autorzy:
Nguyen, Thi Phuong Trang
Tran, Thi Thu Tra
Ton, Nu Minh Nguyet
Le, Van Viet Man
Powiązania:
https://bibliotekanauki.pl/articles/16538534.pdf
Data publikacji:
2023-02-21
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
antioxidant capacity
by-product
dietary fiber
pasta
Opis:
The production of cashew apple juice generates fruit pomace which is rich in dietary fiber and phenolic compounds and shows high antioxidant capacity. In this research, the effects of different ratios of cashew apple pomace powder (CAPP) in the pasta formulation on the product quality were investigated. Increase in CAPP level in the pasta recipe from 0 to 20% enhanced the total dietary fiber and total phenolic content of the product by 4.1 times and 11.8 times, respectively, as well as improved the 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and ferric reducing antioxidant power by 18.2 times and 28.6 times, respectively. Nevertheless, the increased level of CAPP in the pasta recipe resulted in decreased cooking quality, textural properties and overall acceptability of the pasta. Pasta sample with 10% CAPP level in the recipe was considered high-fiber food with acceptable sensory quality. Therefore, CAPP may be considered a promising source of dietary fiber and antioxidants for the development of healthy food products.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2023, 73, 1; 50-58
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The measurement of successful management via a net profit maximization model with ten factors and financial accounting disclosure policy- case of Vinamilk in F&B Industry in Vietnam
Autorzy:
Nga, Le Thi Viet
Lan, Nguyen Thi Ngoc
Yen, Ly Lan
Huy, Dinh Tran Ngoc
Thuy, Do Minh
Powiązania:
https://bibliotekanauki.pl/articles/1818316.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Wydział Ekonomii i Zarządzania
Tematy:
successful management
profit maximization
financial accounting data
stock prices
GDP growth
inflationary
risk free rate
arket interest rate
skuteczne zarządzanie
maksymalizacja zysku
dane księgowe
kurs akcji
wzrost PKB
inflacja
stopa procentowa
Opis:
When a firm has better disclosure policy of financial accounting information it will attract more investment. Many factors affecting accounting information disclosure policy include firm size, leverage, industry characteristics, investor types, etc. And good financial accounting data disclosure will help to reduce risk level of firms. At micro level, cost and net sale factors will affect net profit while at macro levels, risk free rate and exchange rate will impact. According to Nikkei Asian Review, Vinamilk (VNM) is the only brand in F&B industry and the domestic industry leader which ranked 25th among 300 listed companies in the List of ASIA300 Power Performers. It leads the organic trend in milk industry and has made very positive contributions to the overall achievements of economic and social values. Good business management requires us to consider the impacts of multi macro and micro factors on net profit, both internal and external factors, and it contributes to promoting business plan and economic policies for economic growth and stabilizing business operation. By data collection method through statistics, analysis, synthesis, comparison, quantitative analysis to generate qualitative comments and discussion; using econometric method to perform regression equation and evaluate quantitative results, the article analyzed and evaluated the impacts of ten (10) macroeconomic factors such as: stock price, VNIndex, risk free rate, lending rate, cost, sale, inflation, GPD growth, S&P500, exchange rate, etc. on net profit of a leading milk listed company, Vinamilk (VNM) in Vietnam in the 10-year period of 2010-2019, both positive and negative sides. From that regression model and analysis, it will draw leadership features, strengths of this industrial leader. The results of quantitative research, in a ten factor model, show that the decrease in GDP growth and risk free rate, inflation and increase in net sale will have a significant effect and increase VNM net profit, with the highest impact coefficient, the second is decreasing cost. This research finding and recommended policy also can be used as reference in policy for F&B system in many developing countries.
Źródło:
Management; 2020, 24, 2; 1-19
1429-9321
2299-193X
Pojawia się w:
Management
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The capability of terrestrial laser scanning for monitoring the displacement of high-rise buildings
Autorzy:
Pham, Trung Dung
Pham, Quoc Khanh
Cao, Xuan Cuong
Nguyen, Viet Hung
Ngo, Sy Cuong
Powiązania:
https://bibliotekanauki.pl/articles/2020241.pdf
Data publikacji:
2021
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
terrestrial laser scanner
monitoring of displacements
accuracy of displacement
high-rise buildings
skaner laserowy naziemny
modelowanie
przemieszczenia
Opis:
Recently, terrestrial laser scanner (TLS) has been increasingly used to monitor of displacement of high-rise buildings. The main advantages of this technique are time-saving, higher point density, and higher accuracy in comparison with GPS and conventional methods. While TLS is ordinary worldwide, there has been no study of the capability of TLS in monitoring the displacement of high-rise buildings yet in Vietnam. The paper's goal is to build a procedure for displacement monitoring of high-rise buildings and assess the accuracy of TLS in this application. In the experiments, a scanned board with a 60 cm x 60 cm mounted on a moveable monument system is scanned by Faro Focus3D X130. A monitoring procedure using TLS is proposed, including three main stages: site investigation, data acquisition and processing, and displacement determination by the Cloud-to-Cloud method (C2C). As a result, the displacement of the scanned object between epochs is computed. In order to evaluate the accuracy, the estimated displacement using TLS is compared with the real displacement. The accuracy depends on scanning geometry, surface property, and point density conditions. Our results show that the accuracy of the estimated displacement is within ± 2 mm for buildings lower than 50 m of height. Thus, TLS completely meets the accuracy requirements of monitoring displacement in the Vietnam Standards of Engineering Surveying. With such outstanding performance, our workflow of using TLS could be applied to monitor the displacement of high-rise buildings in the reality of geodetic production in Vietnam.
Źródło:
Inżynieria Mineralna; 2021, 2; 495--504
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Studying the thermo-gas-dynamic process in a muzzle brake compensator
Autorzy:
Nguyen, Dung Van
Bui, Viet Quy
Nguyen, Dung Thai
Uong, Quyen Si
Truong, Hieu Tu
Powiązania:
https://bibliotekanauki.pl/articles/27309887.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
thermo-gas-dynamic
muzzle device
muzzle brake compensator
automatic gun
dynamiczny termo-gaz
urządzenie wylotowe
kompensator hamulca wylotowego
pistolet automatyczny
Opis:
To reduce the recoil and improve the stability of small arms, a muzzle brake compensator is attached to the muzzle of the barrel. This device uses the kinetic energy of the powder gas escaping from the bore after the bullet is fired. In this paper, the authors present the determination of the thermo-gas-dynamic model of the operation of a muzzle brake compensator and an example of calculating this type of muzzle device for the AK assault rifle using 7.62x39 mm ammunition. The results of the calculation allowed for obtaining the parameters of the powder gas flow in the process of flowing out of the muzzle device, as well as the change in the momentum of the powder gas's impact on the muzzle device. The model proposed in the article provides the basis for a quantitative evaluation of the effectiveness of using the muzzle device in stabilizing infantry weapons when firing.
Źródło:
Archive of Mechanical Engineering; 2023, LXX, 2; 311--328
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of Suitable Washing Flowsheets For High Ash Coals of Nui Hong Coal Mine
Badanie odpowiednich schematów technologicznych płukania węgli wysokopopiołowych w kopalni Nui Hong
Autorzy:
Pham, Van Luan
Nguyen, Ngoc Phu
Le, Viet Ha
Powiązania:
https://bibliotekanauki.pl/articles/317907.pdf
Data publikacji:
2020
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
Nui Hong Coal Mine
high ash coal
washing
flotation
kopalnia węgla Nui Hong
węgiel wysokopopiołowy
płukanie
flotacja
Opis:
Current high ash coal stockpile of Nui Hong Coal Mine is estimated at about 1 million tonnes. This increasingly stockpiled coal is not sellable and disposable due to the government regulations so that a problem related to space and environment limitations becomes more serious. This report presents the results of the study on washability of Nui Hong high ash coals and proposed suitable flowsheets for washing this type of coals. Basic characteristics of the coals include High ash content of over 55%; High moisture of above 20%, high rate of disintegration into finer particles in water, the high proportion of fine coals of the size fraction 0–6 mm; 30% or more of high ash superfine fraction -0.045 mm that contained mainly slime, clay and fine non-coal organic impurities. The results of particle size analysis and sink-and-float analysis of +1 mm coal sizes indicated that a 1–6 mm clean coal with ash content of less than 45% could be produced by a combination of coal feed crushing, washing and removal of 0–0.1 mm superfine particles. Flotation of the size fraction - 0.1 mm could produce a clean coal float with the ash less than 40%, provided that slimes should be removed before flotation. From results of the study, it was found that the most suitable flowsheet for washing of Nui Hong high ash coals should include crushing of the feed down to -6 (8) mm, washing by rotary scrubber screens to separate clean coal of 0.1–6 (8) mm, desliming of -0.1 mm fraction by spiral classifier before flotation. From the study samples with the average initial ash content of 55%, a common clean coal product with ash content of about 40–45% and with a yield of over 60% were obtained according to the proposed flowsheet. The quality of the clean coal matched with Vietnam coal quality standard as 6B grade fine coal (TCVN) so that it could be supplied to the local thermal power plants.
Obecne zapasy węgla o wysokiej zawartości popiołu w kopalni Nui Hong szacuje się na około 1 mln ton. Ten coraz bardziej gromadzony węgiel nie nadaje się do sprzedaży ani do utylizacji, przez co problem związany z zanieczyszczeniem środowiska staje się coraz poważniejszy. W artykule, przedstawiono wyniki ba-dań nad zmywalnością węgli wysokopopiołowych Nui Hong oraz zaproponowano odpowiedni proces do mycia tego typu węgli. Podstawowe cechy węgli to: wysoka zawartość popiołu powyżej 55%; wysoka wilgotność powyżej 20%, duża szybkość rozpadu na drobne cząstki w wodzie, duży udział drobnych węgli o frakcji wymiarowej 0 - 6 mm; 30% lub więcej bardzo drobnej frakcji o wysokiej zawartości popiołu - 0,045 mm, która zawierała głównie szlam, glinę i drobne zanieczyszczenia organiczne niewęglowe. Wyniki analiz wielkości cząstek i analizy typu densymetrycznych o wielkościach węgla +1 mm tego czystego węgla 1-6 mm z zawartością popiołu poniżej 45% można uzyskać przez połączenie kruszenia, przemywania i usuwania wsadu węglowego 0 - 0,1 mm bardzo drobnych cząstek. Flotacja frakcji wymiarowej - 0,1 mm mogłaby dać czysty pływak węglowy o zawartości popiołu poniżej 40%, pod warunkiem, że szlam powinien zostać usunięty przed flotacją. Na podstawie wyników badań stwierdzono, że najbardziej odpowiednim schematem technologicznym do przemywania węgli wysokopopiołowych Nui Hong powinno być kruszenie nadawy do -6 (8) mm, przemywanie przez płuczki obrotowe w celu oddzielenia czystego węgla o zawartości 0,1 - 6 mm. (8) mm, odmulanie frakcji - 0,1 mm za pomocą spiralnego klasyfikatora przed flotacją. Z próbek badawczych o średniej początkowej zawartości popiołu 55%, zgodnie z proponowanym schematem technologicznym uzyskano pospolity czysty produkt węglowy o zawartości popiołu około 40 - 45% i uzysku powyżej 60%. Jakość czystego węgla odpowiadała wietnamskiemu standardowi jakości węgla jako miał węglowy klasy 6B (TCVN), tak aby mógł być dostarczany do lokalnych elektrociepłowni.
Źródło:
Inżynieria Mineralna; 2020, 1, 2; 239-246
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
Tytuł:
Statistical evaluation of the geochemical data for prospecting polymetallic mineralization in the Suoi Thau–Sang Than region, Northeast Vietnam
Autorzy:
Hung, Khuong The
Sang, Pham Nhu
Phuong, Nguyen
Linh, Vu Thai
Sang, Bui Viet
Powiązania:
https://bibliotekanauki.pl/articles/1841771.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
polymetallic mineralization
statistical evaluation
Suoi Thau-Sang Than region
Vietnam
Opis:
In Northeast Vietnam, Suoi Thau-Sang Than is considered as a high potential area of polymetallic deposits. 1,720 geochemical samples were used to investigate polymetallic mineralization; thereby polymetallic ore occurrences in this study region were discovered and the statistical and multivariate analysis helps to define geochemical anomalies in some northeastern regions, namely Suoi Thau, Sang Than, and Ban Kep. The statistical method and cluster analysis of geochemical data indicate that the Cu, Pb, and Zn elements are good indicators, and most of them comply with the lognormal or gamma distribution. Based on the third-order threshold, the geochemical anomalies of the content of the Cu, Pb, and Zn elements reflect the concentration of copper forming ore bodies in the mineralized zone, and clearly show the concentration in three distinct zones. The trend surface analysis which was employed to determine spatial variations and relationships among these good indicator elements and anomalous areas revealed relative changes in the content of the indicator elements, and they can be considered as regular. Moreover, the goodness of fit obtained trend functions of Pb and Zn, and Cu elements is a third-degree trend surface model. These results indicate that the models can be useful in studying geochemical anomalies and analyzing the tendency of the concentration of indicator elements in the Suoi Thau-Sang Than region. Additionally, it is suggested that the statistical analysis shows a remarkable potential to use the bottom river sediments in the region to investigate polymetallic mineralization. Moreover, geochemical data can help to evaluate geochemical anomalies of the pathfinder elements and potential mineral mapping of the Suoi Thau-Sang Than region in Northeast Vietnam.
Źródło:
Geology, Geophysics and Environment; 2020, 46, 4; 285-299
2299-8004
2353-0790
Pojawia się w:
Geology, Geophysics and Environment
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Simulation on Flyrock due to Blasting Using Smoothed Particle Hydrodynamics (SPH) with LSDyna software
Autorzy:
Dinh, Bao Tran
Van, Trieu Do
Van, Viet Pham
An, Nguyen Dinh
Powiązania:
https://bibliotekanauki.pl/articles/24200704.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
flyrock
smoothed particle hydrodynamics
simulation
blasting
LS-Dyna
Opis:
In surface mining operation, blasting method has been commonly used and accounted highly for breaking waste rock and mineral. The main goal of the activity is fundamental fragmentation by energy generation due to blasting. However, only 20% to 30% blasting energy is generated to fragment rock. The remain energry is wasted for flyrock, ground vibration, air overpressure, dust and too fine fragmentation. Flyrock in blasting is large risk for surface mines and occupies more than a half of incidents relating to blasting at surface mines, because this is a severe issue and causes negative reaction of the surrounding residients. However, studies on flyrock-phenomenon prediction methods for blasting in Vietnam have been also limited. In the study, simulation analysis method on induce-blasting-induced flyrock experiment using Smoothed Particle Hydrodynamics (SPH) with LS-Dyna software. Two-dimension modelling was built and practically applied for B2 cross section of Mong Son quarry in Yen Bai province. The result showed that the ability of Smoothed Particle Hydrodynamics (SPH) in analysizing flyrock trajectory distance in blasting. By using the modelling with field-site parameters, the researcher monitored flyrock velocity at installed time periods, such as 1.5 second when the flyrocks fly with a maximum distance of 85 m from blasting site and their average velocity of 40 m/s.
Źródło:
Inżynieria Mineralna; 2023, 2; 13--21
1640-4920
Pojawia się w:
Inżynieria Mineralna
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:
Separation of Co(II), Cu(II), Ni(II) and Mn(II) from synthetic hydrochloric acid leaching solution of spent lithium ion batteries by solvent extraction
Autorzy:
Nguyen, Viet Nhan Hoa
Lee, Man Seung
Powiązania:
https://bibliotekanauki.pl/articles/1449331.pdf
Data publikacji:
2020
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
spent lithium-ion batteries
divalent metal ions
solvent extraction
separation
Opis:
Spent lithium ion batteries contain valuable critical metals such as cobalt, copper, lithium and nickel. In order to develop a process for the separation of the divalent metal ions from spent lithium ion batteries, solvent extraction experiments were performed by employing synthetic hydrochloric acid leaching solution. The synthetic solution contained Cu(II), Co(II), Mn(II) and Ni(II) and its acidity was 3 M HCl. Extraction with Aliquat 336 led to selective extraction of Cu(II) with a small amount of Co(II). After adding NaCl to the Cu(II) free raffinate to enhance the complex formation of Co(II), Co(II) was selectively extracted into Aliquat 336 together with Mn(II). The small amount of Mn(II) in the loaded Aliquat 336 was scrubbed by pure Co(II) solution. After adjusting the pH of the raffinate to 3, 91,3% of Mn(II) was selectively extracted over Ni(II) by the mixture of D2EHPA and Alamine 336. In this extraction, the mole fraction of D2EHPA in the mixture affected the extraction of Mn(II). McCabe-Thiele diagrams for the extraction of Cu(II) and Co(II) were constructed. Batch simulation experiments for the three stage counter-current extraction verified the selective extraction of the target metal ions in each extraction step. Namely, the total extraction percentage of Cu(II) and Co(II) was 71.6% and 98.8% respectively. Most metals in the loaded organic phase were stripped completely with the appropriate agents (1.0 M $H_2SO_4$ for Cu(II), 0.1 M H2SO4 for Co(II) and 0.3 M $HCl$ for Mn(II) stripping). A process was proposed to separate the metal ions by solvent extraction.
Źródło:
Physicochemical Problems of Mineral Processing; 2020, 56, 4; 599-610
1643-1049
2084-4735
Pojawia się w:
Physicochemical Problems of Mineral Processing
Dostawca treści:
Biblioteka Nauki
Artykuł
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