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    Wyświetlanie 1-14 z 14
    Tytuł:
    Sandy Soil Reclamation Using Biochar and Clay-Rich Soil
    Autorzy:
    Thi, Diep Pham
    Hang, Nga Nguyen Thi
    Viet, On Tran
    Van, Loc Nguyen
    Viet, Anh Nguyen
    Lan, Phuong Dinh Thi
    Van, Nguyen Vu
    Powiązania:
    https://bibliotekanauki.pl/articles/1838287.pdf
    Data publikacji:
    2021
    Wydawca:
    Polskie Towarzystwo Inżynierii Ekologicznej
    Tematy:
    sandy soil
    biochar
    clay-rich soil
    physical properties
    chemical properties
    Opis:
    The investigations on the effects of biochar application in improving the physio-chemical properties of soil have been carried out in many studies; however, there are very few studies on the combined use of both biochar and clay-rich soil for poor nutrient soil reclamation. Therefore, this study demonstrates improved water retention and nutrient retention of sandy soil by using biochar and biochar combined with clay-rich soil. The experiments were conducted on a small scale (greenhouse) with nine different application rates of biochar and clay-rich soil were mixed and then cultivated peanut, along with the drip irrigation technique using field moisture limit (about 70-80%) was applied under the condition of ensuring a sufficient supply of NPK for plant’s growth. The results showed that at the rates from 10.0-15.0% (w/w) clay-rich soil mixed with from 0.5-1.5% (w/w) of biochar applied to the tested sandy soil resulted in the positive effects on soil water holding, bulk density, permeability, pH, CEC, OM, total N, total P and peanut yield. The physical and chemical characteristics of the tested sandy soil have been improved by time and the application rate of 10.0% clay-rich soil and 0.5% biochar had the highest efficiency of pod fresh weight and pod dry weight during three studied seasons.
    Źródło:
    Journal of Ecological Engineering; 2021, 22, 6; 26-35
    2299-8993
    Pojawia się w:
    Journal of Ecological Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sandy Soil Reclamation Using Biochar and Clay-Rich Soil
    Autorzy:
    Thi, Diep Pham
    Hang, Nga Nguyen Thi
    Viet, On Tran
    Van, Loc Nguyen
    Viet, Anh Nguyen
    Lan, Phuong Dinh Thi
    Van, Nguyen Vu
    Powiązania:
    https://bibliotekanauki.pl/articles/1838394.pdf
    Data publikacji:
    2021
    Wydawca:
    Polskie Towarzystwo Inżynierii Ekologicznej
    Tematy:
    sandy soil
    biochar
    clay-rich soil
    physical properties
    chemical properties
    Opis:
    The investigations on the effects of biochar application in improving the physio-chemical properties of soil have been carried out in many studies; however, there are very few studies on the combined use of both biochar and clay-rich soil for poor nutrient soil reclamation. Therefore, this study demonstrates improved water retention and nutrient retention of sandy soil by using biochar and biochar combined with clay-rich soil. The experiments were conducted on a small scale (greenhouse) with nine different application rates of biochar and clay-rich soil were mixed and then cultivated peanut, along with the drip irrigation technique using field moisture limit (about 70-80%) was applied under the condition of ensuring a sufficient supply of NPK for plant’s growth. The results showed that at the rates from 10.0-15.0% (w/w) clay-rich soil mixed with from 0.5-1.5% (w/w) of biochar applied to the tested sandy soil resulted in the positive effects on soil water holding, bulk density, permeability, pH, CEC, OM, total N, total P and peanut yield. The physical and chemical characteristics of the tested sandy soil have been improved by time and the application rate of 10.0% clay-rich soil and 0.5% biochar had the highest efficiency of pod fresh weight and pod dry weight during three studied seasons.
    Źródło:
    Journal of Ecological Engineering; 2021, 22, 6; 26-35
    2299-8993
    Pojawia się w:
    Journal of Ecological Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Variation in Growth and Yield of Sacha Inchi (Plukenetia Volubilis L.) under Different Ecological Regions in Vietnam
    Autorzy:
    Van, Quang Vu
    Thi, Ngoc Yen Pham
    Thi, Tram Nguyen
    Van, Muoi Nguyen
    Van, Thanh Le
    Thi, Bich Ngoc Vu
    Thi, Bich Hong Nguyen
    Powiązania:
    https://bibliotekanauki.pl/articles/2173335.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Inżynierii Ekologicznej
    Tematy:
    ecological region
    growth
    sacha inchi
    selection
    yield
    Opis:
    The sacha inchi seeds (Plukenetia Volubilis L.), collected from different ecological regions of Vietnam (the Northern Mountainous region, the North Central region, and Central Highlands Area), were sown in the spring crop (March 2020) in Gia Lam district, Hanoi city, Vietnam. The variety S18 was copyrighted by Ministry of Agriculture and Rural Developmentof Vietnam in 2019 as a special medicinal plant variety. During the period of 26 months after planting, the agronomical parameters, growth and development characteristics (leaf form, number of inflorescences per branches, number of female flowers per inflorescences, etc.), pests and diseases, yields and yield components (number of seeds per fruit, seed weight, seed grain, etc.), ratio of kernel per seed and ratio of oil per seed were evaluated. The evaluation results show that the collected sacha inchi lines have a time from sowing to flowering and fruiting of 108–125 days, a fruiting to ripening of 123–125 days, and a time from sowing to harvesting the first batch of 244–250 days. The annual harvest is carried out at two main times: May–June and November–January. The actual yield of the first two periods is high (2.66–3.07 tons per hectare), and the highest yield is collected in the Northern Mountainous area is 3.07 tons per hectare (in Tuyen Quang province), while and 3.01 tons per hectare are collected in the North Central region (in Thanh Hoa province). In the nursery, root rot caused 2.1–5.3% deaths and green wilt caused 3.1–4.8% deaths of seedlings. In the planting garden, fruit borers, stem borers, cavity worms and red spiders were discovered, causing more serious damage than other types (from 5 to over 50%). The results of evaluation of growth, development, yield components and yield showed that the sacha inchi lines collected in the North Central region (in Thanh Hoa province) and the Northern Mountainous region (in Tuyen Quang province) is the best.
    Źródło:
    Journal of Ecological Engineering; 2022, 23, 8; 162--169
    2299-8993
    Pojawia się w:
    Journal of Ecological Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Developing an Advanced Soft Computational Model for Estimating Blast-Induced Ground Vibration in Nui Beo Open-pit Coal Mine (Vietnam) Using Artificial Neural Network
    Opracowanie zaawansowanego modelu obliczeniowego do szacowania wibracji gruntu wywołanych wybuchem w odkrywkowej kopalni węgla Nui Beo (Wietnam) przy użyciu sztucznej sieci neuronowej
    Autorzy:
    Nguyen, Hoang
    Bui, Xuan‑Nam
    Tran, Quang Hieu
    Nguyen, Quoc Long
    Vu, Dinh Hieu
    Pham, Van Hoa
    Le, Qui Thao
    Nguyen, Phu Vu
    Powiązania:
    https://bibliotekanauki.pl/articles/317864.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    Wietnam
    górnictwo odkrywkowe
    sieci neuronowe
    Vietnam
    open pit mining
    artificial neural network
    Opis:
    The principal object of this study is blast-induced ground vibration (PPV), which is one of the dangerous side effects of blasting operations in an open-pit mine. In this study, nine artificial neural networks (ANN) models were developed to predict blast-induced PPV in Nui Beo open-pit coal mine, Vietnam. Multiple linear regression and the United States Bureau of Mines (USBM) empirical techniques are also conducted to compare with nine developed ANN models. 136 blasting operations were recorded in many years used for this study with 85% of the whole datasets (116 blasting events) was used for training and the rest 15% of the datasets (20 blasting events) for testing. Root Mean Square Error (RMSE), Determination Coefficient (R2), and Mean Absolute Error (MAE) are used to compare and evaluate the performance of the models. The results revealed that ANN technique is more superior to other techniques for estimating blast-induced PPV. Of the nine developed ANN models, the ANN 7-10-8-5-1 model with three hidden layers (ten neurons in the first hidden layer, eight neurons in the second layers, and five neurons in the third hidden layer) provides the most outstanding performance with an RMSE of 1.061, R2 of 0.980, and MAE of 0.717 on testing datasets. Based on the obtained results, ANN technique should be applied in preliminary engineering for estimating blast-induced PPV in open-pit mine.
    Źródło:
    Inżynieria Mineralna; 2019, 21, 2/2; 58-73
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Developing Criteria for Assessing The Stability of Water Supply Models in High Mountains and Water-Scare Areas
    Autorzy:
    Nguyen, Manh Truong
    Dinh, Anh Tuan
    Nguyen, Tiep Tan
    Vu, Thi Hong Nghia
    Do, Van Binh
    Powiązania:
    https://bibliotekanauki.pl/articles/27323245.pdf
    Data publikacji:
    2023
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    criteria
    water supply
    high mountain
    Vietnam
    kryteria
    Wietnam
    woda
    Opis:
    The article presents the scientific basis for assessing the stability of water supply models and develops a suitable set of criteria to assess the stability of water supply works, which includes the water supply part for water supply works and systems (including headworks and water distribution systems) in high mountains and water-scarce areas in Vietnam. Research results indicate that in order to improve the stability and availability of water of the models that have been, are and will be built, it is necessary to have a common method of evaluating effectiveness for scientific models of domestic water supply. Accordingly, it is necessary to build obtain a suitable set of criteria to assess the stability of the water supply model (source + water supply works) in the high mountains, water-scarce areas in Vietnam.
    Źródło:
    Inżynieria Mineralna; 2023, 2; 179--186
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Design optimization of compliant mechanisms for vibration assisted machining applications using a hybrid Six Sigma, RSM-FEM, and NSGA-II approach
    Autorzy:
    Pham, Huy-Tuan
    Nguyen, Van-Khien
    Dang, Quang-Khoa
    Duong, Thi Van Anh
    Nguyen, Duc-Thong
    Phan, Thanh-Vu
    Powiązania:
    https://bibliotekanauki.pl/articles/24084644.pdf
    Data publikacji:
    2023
    Wydawca:
    Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
    Tematy:
    compliant mechanism
    multi-objective optimisation
    Six Sigma
    NSGA-II
    Opis:
    Vibration-assisted machining, a hybrid processing method, has been gaining considerable interest recently due to its advantages, such as increasing material removal rate, enhancing surface quality, reducing cutting forces and tool wear, improving tool life, or minimizing burr formation. Special equipment must be designed to integrate the additional vibration energy into the traditional system to exploit those spectacular characteristics. This paper proposes the design of a new 2-DOF high-precision compliant positioning mechanism using an optimization process combining the response surface method, finite element method, and Six Sigma analysis into a multi-objective genetic algorithm. The TOPSIS method is also used to select the best solution from the Pareto solution set. The optimum design was fabricated to assess its performance in a vibration-assisted milling experiment concerning surface roughness criteria. The results demonstrate significant enhancement in both the manufacturing criteria of surface quality and the design approach criteria since it eliminates modelling errors associated with analytical approaches during the synthesis and analysis of compliant mechanisms.
    Źródło:
    Journal of Machine Engineering; 2023, 23, 2; 135--158
    1895-7595
    2391-8071
    Pojawia się w:
    Journal of Machine Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Fracture Mechanism of Hard Main Roof and Determining the Width of Coal Pillars when Extracting Flat-lying Coal Seams
    Autorzy:
    Le, Quang Phuc
    Dao, Van Chi
    Nguyen, Phi Hung
    Vu, Thai Tien Dung
    Powiązania:
    https://bibliotekanauki.pl/articles/27323252.pdf
    Data publikacji:
    2023
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    failure mechanism
    coal pillar
    stress distribution
    roadway deformation
    retained roadway
    hard main roof
    gob-side entry
    węgiel
    filary
    stabilność
    Wietnam
    Opis:
    In underground coal mining, the stability of roadways and gob-side entry depends on the coal pillar width. An unreasonable width of the coal pillar will cause the roadway to be in a dangerous zone of influence of the abutment pressure, leading to severe roadway deformation. This paper studies the fracture mechanism of the hard main roof and reasonable coal pillar width to protect the stability of gob-side entry driving. The research results show that when mining a coal seam under a hard main roof, the console of the main roof on the edge of the coal seam has the form of hinge structure. The great load of the roof layers and the rotation of the console are the main causes leading to the variation of the stress field in the coal seam. According to the development law of the stress field, after the main roof completes the collapse process, the peak of the maximum stress will move deep into the solid coal seam, and on the edge of the coal seam it will form a low-stress zone. Research results from the case of Seam #11 of Khe Cham coal mine, Vietnam show that the gob-side entry will be well stabilized when the narrow coal pillar between it and the boundary of the gob is 4–5 m.
    Źródło:
    Inżynieria Mineralna; 2023, 2; 271--280
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Comparison of the Resampling Methods for Gridded DEM Downscaling
    Porównanie metod ponownego próbkowania dla skalowanego w dół zmniejszania DEM
    Autorzy:
    Nguyen, Quang Minh
    Nguyen, Thi Thu Huong
    La, Phu Hien
    Duong, Thi Tuyet Nhung
    Nguyen, Thi Minh Hong
    Vu, Van Anh
    Powiązania:
    https://bibliotekanauki.pl/articles/318242.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    próbkowanie
    skalowanie
    DEM
    resampling
    downscaling
    Opis:
    In this paper, a comparison and evaluation of three resampling methods for gridded DEM is implemented. The evaluation was based on the results of bilinear resampling, bi-cubic and Kriging resampling methods for an experiment using both degraded and sampled datasets at 20 m and 60 m spatial resolutions. The evaluation of the algorithms was accomplished comprehensively with visual and quantitative assessments. The visual assessment process was based on direct comparison of the same topographic features in different downscaled images, scatterplots and profiles. The quantitative assessment was based on the most commonly used parameters for DEM accuracy assessment such as root mean square errors (RMSEs), linear regression parameters m and b, and correlation coefficient R. Both visual and quantitative assessment revealed greater accuracy of the Kriging over the other two conventional methods.
    Źródło:
    Inżynieria Mineralna; 2019, 21, 2/2; 240-248
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Research, Calculation and Proposal of Ventilation Solution for Duong Huy Coal Mine when Mining Down to -250 m Depth
    Autorzy:
    Dao, Van Chi
    Le, Tien Dung
    Vu, Thai Tien Dung
    Nguyen, Hong Cuong
    Powiązania:
    https://bibliotekanauki.pl/articles/2020250.pdf
    Data publikacji:
    2021
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    main fan
    working mode
    ventilation
    airflow
    air pressure
    air velocity
    wentylacja
    ciśnienie
    powietrze
    Opis:
    At present, according to the extraction plan in the year 2020 of Duong Huy Coal Company - Vinacomin, the mining is divided into three main zones: Central Zone extracts 06 faces; South Zone extracts 2 faces and Northeast Zone extracts 2 faces. The designated total production of all zones is 1,880,000 tons/year. To ensure the production of each mining zone, exhaust fan stations are installed at ventilation roadway adits with a total of 05 main fan stations. However, in the near future, to ensure and maintain production activities, the mine is being planned and operated using 03 main fan stations. The calculation results for the reasonable working mode of fan stations are as follows: for fan station FBCDZ8-№32B at level +47 m, airflow is 167.69 m3 /s and air pressure is 243.74 mm H2O; for fan station 2K56- №30 level +40 m, airflow is 123.37 m3 /s and air pressure is 324.79 mm H2O; for fan station FBCDZ-8- №32B at level +44 m, airflow is 167.69 m3 /s and air pressure is 354.99 mm H2O.
    Źródło:
    Inżynieria Mineralna; 2021, 2; 513--520
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Internal Micro-electrolysis Using Fe/C Material for Pre-Treatment of Concentrated Coking Wastewater
    Autorzy:
    Nguyen, Van Tu
    Do, Tra Huong
    Vu, Duy Nhan
    Ngan, Tran Thi Kim
    Powiązania:
    https://bibliotekanauki.pl/articles/1849313.pdf
    Data publikacji:
    2021
    Wydawca:
    Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
    Tematy:
    internal micro-electrolysis
    Fe/C material
    wastewater treatment
    coking wastewater
    Opis:
    Untreated coking effluent presents a great challenge for sustainable development of the steel industry and environment preservation. In this study, an internal micro-electrolysis method using Fe/C materials was employed for pretreatment of real coking wastewater with high mass concentration. The Fe/C materials were prepared by Fe powder and graphite powder; and the characteristics of surface morphology, structure, composition of the synthesized materials were examined by Scanning electron microscopy (SEM), X-ray diffraction (XRD) and Energy Dispersive X-ray Spectroscopy (EDS). The effects of factors namely dosage of Fe/C material, treatment time, initial pH and temperature were investigated via chemical oxygen demand (COD) and phenol removal efficiencies. Optimal treatment efficiency was attained at pH of 4, Fe/C dosage of 40 g/L, treatment time of 360 minutes and temperature of 25°C. After the internal electrolysis process, the values of COD, BOD5, and phenol of the wastewater were 6500, 4850 and 0.1 mg/L, respectively.
    Źródło:
    Polish Journal of Chemical Technology; 2021, 23, 2; 41-46
    1509-8117
    1899-4741
    Pojawia się w:
    Polish Journal of Chemical Technology
    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:
    Assessment of Heavy Metal Pollution in the Surface Water of the Doi-Cho Dem-Ben Luc Rivers, Vietnam
    Ocena zanieczyszczenia metalami ciężkimi wód powierzchniowych rzek Doi-Cho Dem-Ben Luc w Wietnamie
    Autorzy:
    Thieu, Van Vu Duc
    Dinh, Thi Thu Huong
    Nguyen, Thi Truc Thao
    Nguyen, Thuy Lan Chi
    Nguyen, Binh An
    Pham, Anh-Duc
    Powiązania:
    https://bibliotekanauki.pl/articles/2172069.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Przeróbki Kopalin
    Tematy:
    heavy metal pollution
    surface water
    distribution
    river
    Doi-Cho Dem-Ben Luc
    water quality protection
    zanieczyszczenie metalami ciężkimi
    wody powierzchniowe
    dystrybucja
    rzeki
    ochrona jakości wód
    Opis:
    Heavy metals are a pressing concern in terms of their pollution in aquatic ecosystems because of their persistence, environmental toxicity, bioaccumulation. Aquatic environments receive heavy metals in untreated or inadequately treated wastewater from domestic, industrial, agricultural, and navigation sources. The Doi-Cho Dem-Ben Luc Rivers play the key roles of irrigation, navigation and ecological restoration. It is crucial to ascertain the pollution status, influencing factors, ecological risks, and possible sources of heavy metals in the surface water of the Doi-Cho Dem-Ben Luc Rivers. In this study, surface water from 7 sampling sites over was collected from the Doi-Cho Dem-Ben Luc Rivers, over 7 consecutive periods from April 2019 to October 2021. Each surface sample was analyzed for 9 heavy metals including Fe, Mn, Cr, Zn, Cu, Pb, Cd, Ni, As. The sampling technique and sample treatment were done based on the Standard Methods for the Examination of Water and Wastewater. The time and space variation of heavy metal concentrations were examined to test the analysis of variance (ANOVA) and correlation among all the parameters using R statistical software. The results suggest a spatial homogeneity of heavy metals in the surface water the studied rivers. Among all nine examined heavy metals in the studied area, the concentrations of Fe (1.00 ÷ 5.06 mg/L) and Mn (0.14 ÷ 0.28 mg/L) are the highest, and the concentrations of Cr, Cd and As are the lowest that lower limit of detection. The results suggested that the mean concentrations of Fe and Mn were above the acceptable limits of the National technical regulation on surface water quality (QCVN 08-MT: 2015/BTNMT). While the concentrations of Fe, Mn, Zn, Cu, Pb, Ni do not meet the Water quality criteria for aquatic life (United State Environmental Protection Agency). Anthropogenic activities can be the main source of heavy metals in in the surface water of the Doi-Cho Dem-Ben Luc Rivers. Among the heavy metals, a significant positive correlation was observed between Fe, Mn, Zn and Ni (0.64 ÷ 0.87), whereas Cu exhibited a significant positive correlation with Ni (0.51). While Cu and Pb showed a not too strong correlation with Fe, Mn, Zn and Ni (0.25 ÷ 0.48). The distribution of heavy metals may also be influenced by properties of heavy metals and fluctuations in water flows. The results provide guidance for controlling heavry metal pollution and protectting water sources in the Doi-Cho Dem-Ben Luc Rivers.
    Metale ciężkie stanowią palący problem zanieczyszczenia w ekosystemach wodnych ze względu na ich trwałość, toksyczność dla środowiska i bioakumulację. Środowiska wodne sa zasilane w metale ciężkie z nieoczyszczonych lub nieodpowiednio oczyszczonych ścieków ze źródeł domowych, przemysłowych, rolniczych i żeglugowych. Rzeki Doi-Cho Dem-Ben Luc odgrywają kluczową rolę w nawadnianiu terenów, transporcie odnym i odbudowie ekologicznej. Kluczowe znaczenie ma ustalenie stanu zanieczyszczenia, czynników wpływających, zagrożeń ekologicznych i możliwych źródeł metali ciężkich w wodach powierzchniowych rzek Doi-Cho Dem-Ben Luc. W artykule przedstawiono wyniki badania wód powierzchniowych, próbki pobrano z 7 punktów pomiarowych z rzek Doi-Cho Dem-Ben Luc przez 7 kolejnych okresów od kwietnia 2019 r. do października 2021 r. Każda próbka została przeanalizowana pod kątem zawartości 9 metali ciężkich: Fe, Mn, Cr , Zn, Cu, Pb, Cd, Ni, As. Metodyka pobierania próbek i obróbki próbek zostały opracowane w oparciu o Standardowe Metody Badania Wód i Ścieków. Zbadano zmienność w czasie i przestrzeni stężeń metali ciężkich, do analizyy wyników wykorzystano analizę wariancji (ANOVA) i korelacji między wszystkimi parametrami przy użyciu oprogramowania statystycznego. Wyniki sugerują przestrzenną jednorodność zawartości metali ciężkich w wodach powierzchniowych badanych rzek. Spośród wszystkich dziewięciu badanych metali ciężkich w badanym terenie najwyższe są stężenia Fe (1,00 ÷ 5,06 mg/L) i Mn (0,14 ÷ 0,28 mg/L), a najniższe Cr, Cd i As (wartości odpowiadające dolnej granicy wykrywalności). Wyniki wskazują, że średnie stężenia Fe i Mn były powyżej dopuszczalnych limitów, opisanych w krajowych normach dotyczących jakości wód powierzchniowych (QCVN 08-MT: 2015/BTNMT). Natomiast stężenia Fe, Mn, Zn, Cu, Pb, Ni nie spełniają kryteriów jakości wody dla organizmów wodnych (Agencja Ochrony Środowiska Stanów Zjednoczonych). Działalność antropogeniczna może być głównym źródłem metali ciężkich w wodach powierzchniowych rzek Doi-Cho Dem-Ben Luc. Wśród metali ciężkich zaobserwowano istotną dodatnią korelację między zawartością Fe, Mn, Zn i Ni (0,64 ÷ 0,87), natomiast Cu wykazywała istotną dodatnią korelację z Ni (0,51). Zawartości Cu i Pb wykazywały niezbyt silną korelację z Fe, Mn, Zn i Ni (0,25 ÷ 0,48). Na rozmieszczenie metali ciężkich mogą mieć również wpływ właściwości metali ciężkich oraz wahania przepływów wody. Wyniki dostarczają wskazówek dotyczących kontrolowania zanieczyszczenia metalami ciężkimi i ochrony źródeł wody w rzekach Doi-Cho Dem-Ben Luc.
    Źródło:
    Inżynieria Mineralna; 2022, 2; 85--90
    1640-4920
    Pojawia się w:
    Inżynieria Mineralna
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Sediment discharge and storage over the last deglacial highstand period on the central Vietnam shelf off Nha Trang
    Autorzy:
    Dung, Bui Viet
    Stattegger, Karl
    Kieu, Nguyen Van
    Thanh, Nguyen Trung
    Thong, Bui Xuan
    Vu, Pham Nguyen Ha
    Man, Ha Quang
    Trang, Pham Hong
    Powiązania:
    https://bibliotekanauki.pl/articles/2058662.pdf
    Data publikacji:
    2019
    Wydawca:
    Państwowy Instytut Geologiczny – Państwowy Instytut Badawczy
    Tematy:
    sediment budget
    Nha Trang shelf
    central Vietnam
    Holocene highstand
    sequence stratigraphy
    Opis:
    A sediment budget for the central Vietnam shelf off Nha Trang over the last deglacial Holocene highstand period has been investigated on the basis of shallow seismic and sediment core data and empirical equations. The annual suspended sediment discharge to the Nha Trang shelf ranges from: 4.3 to 5.4 Mt/year. Estimates based on published empirical equations suggest that the sediment discharge by three main local mountainous rivers (the Cai, Dinh and Van Phong rivers) that enter the Nha Trang shelf ranges between 1.7 and 4 Mt/year, which implies that the local rivers discharge approximately 75% of the total annual sediment input to the shelf. The annual sediment supply of the Cai River is approximately 2 and 6 times higher than that of the Dinh and Van Phong rivers, respectively. The highstand sediment depocentre of the Nha Trang shelf is mostly attached to the local river outflows, indicating their importance as the principal sediment supply sources to the shelf. Additional sources of sediment supply to the Nha Trang shelf can probably be related to along-shore transport from the nearby shelves. Calculations based on seismic and sediment core data indicate that the net sediment volume storage on the Nha Trang shelf is approximately 2.15 Mt/year. Approximately 50% of the total sediment yield supplied to the shelf is probably transported along-shore to the south. The sediment budget model for highstand deposits on the Nha Trang shelf is typical for a small mountainous river basin, which is significantly different from that of the large river delta systems in Vietnam such as the Mekong and Red rivers where 90% of the river sediments are captured on the delta plain/subaqueous part and only 10% of the river sediments are transported to the nearby shelf. In contrast, most of the sediments supplied by small mountainous rivers off Nha Trang are transported to the mid-shelf, forming a shore-parallel mud depocentre.
    Źródło:
    Geological Quarterly; 2019, 63, 2; 395--406
    1641-7291
    Pojawia się w:
    Geological Quarterly
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Temporal and spatial heterogeneity of the Ailaoshan–Song Ma–Song Chay ophiolitic mélange, and its significance on the evolution of Paleo-Tethys
    Autorzy:
    Lin, Wei
    Liu, Fei
    Wang, Ying
    Meng, Lingtong
    Faure, Michel
    Chu, Yang
    Nguyen, Vuong Van
    Wu, Qinying
    We, Wei
    Thu, Hoai Luong Thi
    Vu, Tich Van
    Powiązania:
    https://bibliotekanauki.pl/articles/24202127.pdf
    Data publikacji:
    2023
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    Tethys
    heterogeneity
    Vietnam
    Opis:
    The ophiolite is the direct evidence to restore the oceanic evolution, and it is used to identify the convergence boundary of the plates. Compared with ophiolite, ophiolitic mélange, especially its matrix, contains more information about the evolution of ocean. The evolution of eastern Paleo-Tethys, between the South China and Indochina blocks, recorded the whole process of rifting from Gondwana and their northward migration and convergence. To understand the tectonic implications from matrix of ophiolitic mélange, the Mesozoic Paleo-Tethys Ailaoshan–Song Ma–Song Chay suture zone located in the North Vietnam–Southeast Yunnan region acts as an ideal study area. Based on the structural geology, we reviewed previous zircon U-Pb dating and Lu-Hf isotopic analyses on the detrital zircon from the Ailaoshan–Song Ma–Song Chay ophiolitic mélange. Accordingly, we subdivide the matrix of these ophiolitic mélange into four parts (M1, M2, M3, and M4; Fig. 1). M1 is mainly located in the middle segment of the Ailaoshan–Song Ma belt. It shows age peaks of 440 Ma and 960 Ma with εHf(t) values of −19.6 ~ +10.3. M2 is mainly located in the NW segment of the Ailaoshan–Song Ma belt, showing a dominant age peak of ~260 Ma. Particularly, it has εHf(t) values of −28.9 ~ +8.1. M3 is mainly located in the SE segment of the Ailaoshan–Song Ma belt, showing the peaks at ~250 Ma, 440 Ma, and 960 Ma with εHf(t) values of −21.9 ~ +10.1. M4 is mainly located in the Song Chay belt, showing the peaks at ~310 Ma, 470 Ma, 610 Ma, 770 Ma, and 965 Ma with εHf(t) values of −28.2 ~ +10.8. The geochronological data of the detrital zircon from the matrix of the Ailaoshan– Song Ma–Song Chay ophiolitic mélange zone, documents a temporal heterogeneity between the M1, M2, M3, and M4 units, which formed at 310–270 Ma, 265–250 Ma, 245–240 Ma, and 310–255 Ma, respectively. The different components and provenances of each unit reflect a strike-parallel heterogeneity (Fig. 1). The M1 unit was mainly sourced from the Paleozoic sedimentary rocks of the Indochina Block (IB). The main provenance for the M2 unit is Emeishan Large Igneous Province (ELIP). The magmatic arc developed in the IB provided the materials for the M3 unit, and the detrital materials of the M4 were mainly sourced from the South China Block (SCB) (Fig. 1). The Cenozoic strike-slip deformation led to an inverted geometry of the M1, M2, and M3 units, accounting for a strike-perpendicular heterogeneity straight to the strike of the orogenic belt. The temporal, strike-parallel, and strike-perpendicular heterogeneity help us to decipher the tempo-spatial evolution of the Paleo-Tethys. The M1, M2, M3, and M4 units contain information from different evolutionary stages, likely recording the comprehensive history of the ancient oceanic basin. Importantly, our results demonstrate that both the active continental margin of the IB and the passive continental margin of the SCB acted as provenance sources that supplied significant amount of detrital material in the ophiolitic mélange matrix, indicating that the Paleo-Tethys Ocean was a “narrow” or “limited” ocean rather than the archipelagic ocean proposed before.
    Źródło:
    Geotourism / Geoturystyka; 2023, 1-2 (72-73); 42--43
    1731-0830
    Pojawia się w:
    Geotourism / Geoturystyka
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
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