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Tytuł:
A study on the influence of printing orientation in metal printing using material extrusion technology on the mechanical properties of 17-4 stainless steel products
Autorzy:
Dang, Long Cao
Nguyen, Cuong Van
Le, Anh Hoang
Bui, Danh Thanh
Powiązania:
https://bibliotekanauki.pl/articles/28407327.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
additive manufacturing
material extrusion
17-4 PH stainless steel
mechanical properties
Opis:
This study investigated the influence of print orientation on the mechanical properties of 17-4 PH stainless steel parts fabricated using material extrusion technology. Tensile test specimens were 3D printed in different orientations (flat, on-edge, and upright), and their mechanical properties were evaluated. The results showed that the print orientation significantly affected the ultimate tensile strength, yield strength, and elongation at failure of the specimens. The flat and on-edge orientations exhibited similar mechanical properties, while the upright orientation resulted in lower strength and higher fracture susceptibility. Hardness measurements also indicated variations in hardness distribution among the orientations. The findings emphasize the importance of optimizing the print orientation parameter to achieve desired mechanical characteristics in 17-4 PH stainless steel parts.
Źródło:
Journal of Machine Engineering; 2023, 23, 4; 89--100
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
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:
Dynamics of Automatic Firing System Type Gas-Operated Weapon
Autorzy:
Nguyen, Phon D.
Vo, Bien Van
Nguyen, Phu M.
Tran, Thanh H.
Powiązania:
https://bibliotekanauki.pl/articles/27314927.pdf
Data publikacji:
2023
Wydawca:
Wojskowa Akademia Techniczna im. Jarosława Dąbrowskiego
Tematy:
automatic firing system
PKMS machine gun
gas operated weapon
Opis:
The paper presents a new approach to establish a mathematical model of an automatic firing system of gas-operated weapons, which is based on the Lagrange's theory. In contrast to previous studies, a dynamic model is supplemented with dynamic link between a basic mechanism and a receiver assembly with longitudinal clearance without taking into account horizontal clearance. The automatic firing system of the PKMS machine gun has been selected for calculation of a theoretical model and a verification test. Through comparison between theoretical and experimental results, the mathematical model is proven to be accurate and reliable. The results obtained from the paper are the basis for evaluating the automatic firing system ability to work. This is also a reliable source of reference for designers in the process of optimising the structure of the automatic firing system.
Źródło:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa; 2023, 14, 4 (54); 9--22
2081-5891
Pojawia się w:
Problemy Mechatroniki : uzbrojenie, lotnictwo, inżynieria bezpieczeństwa
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid end-to-end approach integrating online learning with face-identification system
Autorzy:
Nguyene, Dat Van
Nguyen, Son Trung
Pham, Thi Hong Anh
Pham, Van Toan
Hoang, Thao Thu
Thanh, Ta Minh
Powiązania:
https://bibliotekanauki.pl/articles/27312886.pdf
Data publikacji:
2023
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
facial recognition
visual search engine
end-to-end applications
online learning
ElasticSearch (ES)
ES
Opis:
Facial recognition has been one of the most intriguing and exciting research topics over the last few years. It involves multiple face-based algorithms such asfacial detection, facial alignment, facial representation, and facial recognition. However, all of these algorithms are derived from large deep-learning architectures, leading to limitations in development, scalability, accuracy, and deployment for public use with mere CPU servers. Also, large data sets that contain hundreds of thousands of records are often required for training purposes. In this paper, we propose a complete pipeline for an effective face-recognition application that requires only a small data set of Vietnamese celebrities and a CPU for training, solving the problem of data leakage, and the need for GPU devices. The pipeline is based on the combination of a conversion algorithm from face vectors to string tokens and the indexing & retrieval process by Elasticsearch, thereby tackling the problem of online learning in facial recognition. Compared with other popular algorithms on the same data set, our proposed pipeline not only outperforms the counterpart in terms of accuracy but also delivers faster inference, which is essential to real-time applications.
Źródło:
Computer Science; 2023, 24 (1); 141--161
1508-2806
2300-7036
Pojawia się w:
Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identifying Key Parameters Influencing Soil Quality at Various Depths in Tram Chim National Park, Dong Thap Province, Vietnam
Autorzy:
Giao, Nguyen Thanh
Nhien, Huynh Thi Hong
Dan, Truong Hoang
Ni, Duong Van
Powiązania:
https://bibliotekanauki.pl/articles/2202379.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
soil quality
national park
organic matter
alkaline soil
multivariate analysis
Opis:
This study used multivariate statistics including cluster analysis (CA) and principal component analysis (PCA) to evaluate the variability and key indicators causing changes in soil quality in Tram Chim National Park, Dong Thap province, Vietnam. Soil samples were collected in the dry season at the habitats of Ischaemum rugosum (CM), Panicum repens (CO), Nelumbo nucifera (LS), Eleocharis dulcis (NO), Oryza rufipogon (LM), Rice field (RL), Melaleuca cajuputi (T) in two layers: A (0–20 cm) and B (20–40 cm). The parameters of pH, total nitrogen (TN), total phosphorus (TP), total acidity (TA), organic matter (OM), total iron (Fe) and exchanged aluminum (Al3+) were used to assess soil quality. The results showed that soil pH was low in both A and B layers. Fe and Al were both high, and the concentrations of these metals in layer A were higher than those in layer B. The OM content was medium while the TN and TP levels were very low. Most of the soil quality indicators tended to decrease with the depth (except for TA). The results of CA analysis showed that there was almost no major change in soil quality between the two soil layers; however, the soil quality in rice field habitat was different from other habitats. The cause may be due to human impact in adding fertilizers/pesticides during farming practices. The PCA results showed at least five influencing factors, explaining 99.7% and 99.9% of soil quality variation in A and B layers. The Al3+, TA, OM, and TP parameters had the main influence on the soil quality of layer A. Meanwhile, the pH, Al3+, TA, TN, Fet indicators had influence on the soil quality of layer B. These indicators need to be future surveyed to assess the evolution of soil quality in the study area.
Źródło:
Journal of Ecological Engineering; 2023, 24, 2; 81--91
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Investigation of Marine Sediments with a Subbottom Profilers System in West Coast of Camau, Vietnam
Autorzy:
Dung, Nguyen Quang
Giang, Nguyen Van
Thanh, Le Ngoc
Powiązania:
https://bibliotekanauki.pl/articles/27323269.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
west coast of Camau
high-resolution shallow seismic
sub-bottom profiler
cross-section
Holocene-Pleistocene sediments
Sejsmika
Wietnam
profile
Opis:
The west coast of Camau (Southeast Vietnam) connects two semi-enclosed East Sea and Thailand Bays, allowing water exchange between them. Despite its importance to the oceanographic evolution of the region, it has still been poorly studied. Therefore, Subbottom profilers are used across shallow sea waters with some applications, such as sea-level studies, sedimentation process and geomorphology. In the whole survey area, 6 high-resolution shallow seismic measurements have been performed with a total length of 60.6 km, and all have recorded good reflected signals in the range 20–70 ms. In this section, physical characteristics and nature of petrology in the survey environment are quite uniformly shown. The topography of the seabed in the survey area tends to be gradually shallower from west to east, and is relatively flat. Particularly, on the cross section of the T1 line, it is visible that the first section of the line has a rather steep and deep terrain, which may be the slope of the continental shelf in the survey area. Wedge-shaped, oblique, corrugated and transverse structures all appear on the cross-sections. In the survey area, the shallow geological structure in the Holocene sediments is divided into 4 layers, and the structural boundary between the Holocene and Pleistocene sediments at the depth of 25–35 m is observed. In addition, geological faults are also detected on geological sections from seismic sections. For instance, at the section of T6 line, two faults were detected at the beginning of the line. The displacement amplitude of these faults ranges between 1.5–4 m. This new dataset will contribute to future comprehension of the geologic and oceanographic evolution.
Źródło:
Inżynieria Mineralna; 2023, 2; 215--223
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-objective optimization of the rotary turning of hardened mold steel for energy saving and surface roughness improvements
Autorzy:
Doan, Tat Khoa
Nguyen, Trung Thanh
Van, An-Le
Powiązania:
https://bibliotekanauki.pl/articles/28407330.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
rotary turning
specific cutting energy
surface roughness
VCPSO
Opis:
In this investigation, the specific cutting energy (SCE) and average surface roughness (Ra) were decreased using the hard-rotary turning (HRT) factors, including the inclined angle (I), depth of cut (D), feed rate (f), and spindle speed (S). The Bayesian regularized feed-forward neural network was applied to develop the SCE and Ra models. The entropy method and vibration and communication particle swarm optimization (VCPSO) algorithm were employed to compute the weights and determine optimal factors. The optimizing outcomes presented that the optimal I, D, f, and S were 35 deg., 0.45 mm, 0.50 mm/rev., and 1200 rpm, respectively, while the SCE and Ra were decreased by 37.4% and 6.6%, respectively. The total turning cost was saved by 7.5% at the selected solution. The valuable outcomes could be applied to the practical HRT process to decrease performance measures, while the developed HRT operation could be utilized for machining difficult-to-cut materials.
Źródło:
Journal of Machine Engineering; 2023, 23, 4; 101--121
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Performance optimization of multi-roller flat burnishing process in terms of surface properties
Autorzy:
Le, Minh-Thai
Van, An-Le
Nguyen, Trung Thanh
Powiązania:
https://bibliotekanauki.pl/articles/24084649.pdf
Data publikacji:
2023
Wydawca:
Wrocławska Rada Federacji Stowarzyszeń Naukowo-Technicznych
Tematy:
roller burnishing
average roughness
Brinell hardness
process parameter
Opis:
In the current investigation, two primary indicators, including the average roughness (AR) and Brinell hardness (BH) of the roller burnishing operation are enhanced using the optimal inputs (the spindle speed-S, feed rate-f, and depth of penetration-D). The performance measures are developed using the Kriging approach and optimal outcomes are generated by the Crow Search Algorithm (CSA). The optimal outcomes generated by the CSA of the S, f, and D were 832 rpm, 112 mm/min, and 0.12 mm, while the AR was reduced by 37.0% and the BH was increased by 29.9%, respectively. The optimal findings could be utilized in the practice for enhancing the burnished quality and to develop a professional system related to the roller burnishing operation. The Kriging-based AR and BH correlations could be used to present nonlinear experimental data. The optimizing technique could be utilized to deal with optimizing problems for different machining operations.
Źródło:
Journal of Machine Engineering; 2023, 23, 2; 159--173
1895-7595
2391-8071
Pojawia się w:
Journal of Machine Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Workflow of Ground Penetrating Radar Data Analysis Based on Maximum Energy Difference Steering
Przebieg pracy z danymi radarowymi penetrującymi ziemię Analiza oparta na sterowaniu maksymalną różnicą energii
Autorzy:
Dang, Duy Hoang
Le, Cuong Van Anh
Nguyen, Thuan Van
Nguyen, Long Quoc
Huynh, Nhan Thanh
Powiązania:
https://bibliotekanauki.pl/articles/28756746.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
ground penetrating radar
phase analysis
energy difference
radar penetrujący podłoże
analiza fazowa
różnica energii
Opis:
Ground Penetrating Radar is commonly used in civil engineering sectors. Underground anomalies (i.e., electric wires, water pipes or sinkholes) can be detected through representations of hyperbolae in the measured processed GPR image. Our work focuses on detecting the underground objects and understanding their metallic or nonmetallic characteristics. The max energy difference attribute is applied to illuminate their positions while phase analysis process can determine change of phase spectrum in the diffracted signals. For improving phase analysis, we applied a novel workflow combining conventional processed steps and a zooming step for preserving phase originality without disturbed by any unnecessary filters. We applied the workflow in model and real data for proving its effectiveness. Interpretation of two real datasets in Vietnam by our workflow can express existences of the artificial underground anomalies as well as their matter characteristics comparing to their surrounding environments.
Ground Penetrating Radar jest powszechnie stosowany w inżynierii lądowej i wodnej. Podziemne anomalie (np. przewody elektryczne, rury wodociągowe lub zapadliska) można wykryć za pomocą reprezentacji hiperbol w zmierzonym przetworzonym obrazie GPR. Nasza praca koncentruje się na wykrywaniu podziemnych obiektów i zrozumieniu ich metalicznych lub niemetalicznych wła-ściwości. Atrybut maksymalnej różnicy energii jest stosowany do oświetlania ich pozycji, podczas gdy proces analizy fazowej może określić zmianę widma fazowego w dyfrakcyjnych sygnałach. Aby usprawnić analizę fazową, zastosowaliśmy nowatorski przepływ pracy łączący konwencjonalne kroki przetwarzania i krok powiększania w celu zachowania oryginalności fazy bez zakłócania przez niepotrzebne filtry. Zastosowaliśmy przepływ pracy w modelu i rzeczywistych danych, aby udowodnić jego skuteczność. Interpretacja dwóch rzeczywistych zbiorów danych w Wietnamie za pomocą naszego przepływu pracy może wyrazić istnienie sztucznych anomalii podziemnych, a także ich charakterystykę materii w porównaniu z otaczającym je środowiskiem.
Źródło:
Inżynieria Mineralna; 2023, 1; 195--202
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Business strategy during Covid pandemic event: survival plans of instant coffee manufacturers in Vietnam
Strategia biznesowa podczas pandemii Covid: plany przetrwania producentów kawy natychmiastowej w Wietnamie
Autorzy:
Tran, Van Nguyen An
Do, Thi Thanh Nhan
Novak, Petr
Powiązania:
https://bibliotekanauki.pl/articles/27315189.pdf
Data publikacji:
2022
Wydawca:
Politechnika Częstochowska
Tematy:
covid pandemic
business strategy
instant coffee
pandemia Covid
strategia biznesowa
kawa rozpuszczalna
Opis:
In Vietnam, the covid situation started in the beginning of 2020 but not until May 2021, it severely impacts the country economically and socially. Some of the top instant coffee producers in Vietnam are struggling to calibrate their business decision-making to survive but others are taking advantage of the situation and fetch for opportunistic expansion. The theoretical framework initiates a global examination in the coffee industry to seek understandings through different business approaches from international organizations against the pandemic and determines dominant components succor firms to overcome adversities. Specifically, this study focuses on understanding the business strategies of Vietnam instant coffee manufacturers using business case study and unstructured interview. The result unveils that for the company survival plan categorizes into three directions: expanding, hibernating, and idling tactic. The paper suggests that during the pandemic event, the business decision-making highly relates to the degree of automation and liquidation. Furthermore, the study suggests that the decision of whether to embrace vertical or horizontal acquisition tactic during this period is a dependent variable with the magnitude of synchronization among the firm sub-business ecosystem. The study, hence, suggested instant coffee manufacturer to establish a set of backup plan in case of unexpected pandemic occasions by improving their automation degree and upgrading its liquidation channels.
W Wietnamie sytuacja krukowa zaczęła się na początku 2020 r., ale dopiero w maju 2021 r. ma poważny wpływ na gospodarczo i społecznie kraj. Niektórzy z czołowych producentów kawy rozpuszczalnej w Wietnamie walczą o dostosowanie swoich decyzji biznesowych, aby przetrwać, ale inni wykorzystują sytuację i szukają oportunistycznej ekspansji. Ramy teoretyczne inicjują globalne badanie branży kawowej w celu znalezienia zrozumienia poprzez różne podejścia biznesowe organizacji międzynarodowych przeciwko pandemii i określają dominujące elementy, które pomagają firmom przezwyciężać przeciwności losu. W szczególności niniejsze badanie koncentruje się na zrozumieniu strategii biznesowych wietnamskich producentów kawy rozpuszczalnej przy użyciu studium przypadku biznesowego i nieustrukturyzowanego wywiadu. Wynik pokazuje, że plan przetrwania firmy dzieli się na trzy kierunki: taktyka ekspansji, hibernacji i bezczynności. Artykuł sugeruje, że podczas pandemii podejmowanie decyzji biznesowych w dużym stopniu zależy od stopnia automatyzacji i likwidacji. Ponadto badanie sugeruje, że decyzja, czy przyjąć taktykę pionowego lub poziomego przejęcia w tym okresie, jest zmienną zależną o wielkości synchronizacji między ekosystemem podfirmowym firmy. Badanie sugerowało zatem producentowi kawy rozpuszczalnej ustalenie planu awaryjnego na wypadek nieoczekiwanych sytuacji pandemii poprzez poprawę stopnia ich automatyzacji i unowocześnienie kanałów likwidacji.
Źródło:
Polish Journal of Management Studies; 2022, 25, 2; 357--374
2081-7452
Pojawia się w:
Polish Journal of Management Studies
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental study of the hydraulic jump length in a smooth trapezoidal channel
Autorzy:
Ngoc, Nguyen Minh
Cuong, Pham Hong
Son, Tran Thanh
Nam, Nguyen Van
Phong, Nguyen Thanh
Powiązania:
https://bibliotekanauki.pl/articles/35547843.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
jump lenght
roller length
hydraulic jump
trapezoidal channel
spillway
Opis:
The article showed the result of investigation of the length of hydraulic jump in trapezoidal channel. In this study, the basic factors that affect the length (Lj) and roller length (Lr) of hydraulic jump were investigated by physical trapezoidal channel’s model. The experiment carried out in purpose to establish a new empirical equation for calculating the roller length (Lr) of the jump in the horizontal trapezoidal channel with the upstream flow Froude number 4.0 to 9.0 (the steady jump). The hydraulic characteristics of forced jump were measured and statistically calculated by excel software. The results of data analysis showed that the MAPE was relatively small (< 5%), and R2 > 0.9 (strong correlation between predicted and observed values) and other statistical indicators are less than 0.1 (MSE = 0.004, RMSE = 0.062 và MEA = 0.047). Therefore, the equation found could be appropriated and applied to calculate characteristics of hydraulic jump trapezoidal channel.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2022, 31, 1; 63-76
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Hybrid robot hand for stably manipulating one group objects
Autorzy:
Nguyen, Pho Van
Nguyen, Phi N.
Nguyen, Tan
Le, Thanh Lanh
Powiązania:
https://bibliotekanauki.pl/articles/27309856.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
hybrid gripper
soft gripper
manipulate group objects
handle multiple objects
hybrid
robot hand
chwytak hybrydowy
miękki chwytak
manipulowanie obiektami grupowymi
Opis:
Autonomous manipulation of group objects requires the gripper/robot hand to achieve high productivity without poor outcomes such as object slippage and damage. This article develops the robot hand capable of achieving effective performance in each trial of grasping the group objects. Our proposed robot hand consists of two symmetrical groups of hybrid fingers having soft pads on the grasping interfaces, which operate as a comb. The grasping ability of this robot hand was theoretically and experimentally validated by handling three groups of objects showcases: tea packs, toothbrushes, and mixing sticks. Additionally, validation results were compared with those of another soft robot hand having soft Pneunet fingers. In each trial, the experimental results showed that the proposed robot hand with hybrid fingers achieved more stable grasping states characterized by a higher number of grasped objects than those in the case of the soft robot hand. Also, experimental results were in good agreement with the predictions of the proposed theoretical analysis. Finally, better performances of the hybrid robot hand in handling the group object provide the bases for developing a novel-robotic application in industrial production.
Źródło:
Archive of Mechanical Engineering; 2022, LXIX, 3; 375--391
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Responses of the Micro-Crustacean, Daphnia magna, across Five Generations Continuously Exposed to Di-2-Ethylhexyl Phthalate in Mekong River Water
Reakcje mikroskorupiaków, Daphnia magna, w ciągu pięciu pokoleń stale narażonych na działanie ftalanu di-2-etyloheksylu w wodzie rzeki Mekong
Autorzy:
Tran, Vinh-Quang
Nguyen, Van-Tai
Dao, Thanh-Son
Powiązania:
https://bibliotekanauki.pl/articles/2175329.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
chronic effects
Daphnia magna
energy cost
life traits
plastic additives
skutki chroniczne
zużycie energii
cechy życiowe
dodatki do tworzyw sztucznych
Opis:
Plastic pollution has been considered as an emerging environmental problem, and is among the ecological and human health concerns. Detrimental impacts of plastic pollution on living things are closely related to the plastic additives added onto the polymer during plastic manufacture. Di-2-ethylhexyl phthalate (DEHP) is one of the most common plasticizers and is usually found in water environment worldwide. Plastic additives can cause many negative effects on aquatic organisms such as fish and zooplankton. This study aimed to assess the chronic effects of DEHP on the life history traits of an ecotoxicological model micro-crustacean, Daphnia magna, across five generations (F0–F4). We used the natural water from Mekong River in Vietnam as the medium for the D. magna incubation in laboratory conditions. The concentrations of trace elements (e.g., metals and pesticides) in the natural water were under detection levels of equipment or very low which was sufficient for D. magna to grow well. The results showed that the body length was the main endpoint of the organisms inhibited by DEHP across all generations. DEHP adversely impacted the survival and fecundity of D. magna in the fourth generation (F3) only. The adverse effects of DEHP on body length of D. magna should be the consequence of the energy cost and allocation in the exposed organisms. The survival and reproduction responses of D. magna to DEHP across five generations could be explained by (i) the severe effects of the chemical on many individuals in the organism cohort, and (ii) toxin-tolerant development in the remaining exposed organisms. Although the trace elements in natural water from Mekong River were not toxic to D. magna at very low concentrations, together with DEHP they might enhance impacts on the organism. Besides, a multigenerational exposure to DEHP would reflect clearer impacts on the organism than a single exposure. Our results could be useful for extrapolation on the influence of plasticizers on freshwater zooplankton in nature.
Zanieczyszczenie tworzywami sztucznymi zostało uznane za narastające zagrożenie środowiskowe i jest jednym z problemów ekologicznych związanych ze zdrowiem człowieka. Szkodliwy wpływ zanieczyszczenia tworzywami sztucznymi na organizmy żywe jest ściśle związany z dodatkami tworzyw sztucznych dodawanymi do polimeru podczas produkcji tworzyw sztucznych. Ftalan di2-etyloheksylu (DEHP) jest jednym z najpowszechniejszych plastyfikatorów i zwykle występuje w środowisku wodnym na całym świecie. Dodatki do tworzyw sztucznych mogą powodować wiele negatywnych skutków dla organizmów wodnych, takich jak ryby i zooplankton. Badania przedsatwione w artykule miały na celu ocenę ciągłego wpływu DEHP na cechy historii życia modelu ekotoksykologicznego mikroskorupiaka, Daphnia magna, w ciągu pięciu pokoleń (F0–F4). Jako pożywkę do inkubacji D. magna w warunkach laboratoryjnych wykorzystano naturalną wodę z rzeki Mekong w Wietnamie. Stężenia pierwiastków śladowych (np. metali i pestycydów) w naturalnej wodzie były poniżej poziomu wykrywalności sprzętu lub bardzo niskie, co było wystarczające, aby D. magna dobrze się rozwijała. Wyniki pokazały, że długość ciała była głównym punktem oceny rozwoju organizmów hamowanego przez DEHP we wszystkich pokoleniach. DEHP negatywnie wpłynął na przeżywalność i płodność D. magna jedynie w czwartym pokoleniu (F3). Negatywny wpływ DEHP na długość ciała D. magna powinien być konsekwencją zużycia energii i jej alokacji w narażonych organizmach. Reakcje D. magna na przetrwanie i reprodukcję pod wpływem DEHP w ciągu pięciu pokoleń można wytłumaczyć (i) poważnym wpływem substancji chemicznej na wiele osobników w populacji organizmów oraz (ii) rozwojem tolerancji na toksyny u pozostałych narażonych organizmów. Chociaż pierwiastki śladowe w naturalnej wodzie z Mekongu nie były toksyczne dla D. magna w bardzo niskich stężeniach, to razem z DEHP mogą nasilać oddziaływanie na organizm. Poza tym wielopokoleniowe narażenie na DEHP odzwierciedlałoby wyraźniejszy wpływ na organizm niż jednorazowe narażenie. Przedstawione wyniki mogą być przydatne do ekstrapolacji wpływu plastyfikatorów na zooplankton słodkowodny w przyrodzie.
Źródło:
Inżynieria Mineralna; 2022, 2; 77--83
1640-4920
Pojawia się w:
Inżynieria Mineralna
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:
Water Lettuce (Pistia stratiotes L.) as a Potential Material for Biogas Production
Autorzy:
Cong, Nguyen Van
Thanh, Tran Van
Kha, Le Thi Mong
Hoang, Nguyen Xuan
Powiązania:
https://bibliotekanauki.pl/articles/2105278.pdf
Data publikacji:
2022
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
water lettuce
anaerobic digestion
renewable energy
Opis:
This study evaluated the biogas production potential of water lettuce (Pistia stratiotes L.) by batch anaerobic digestion under in-vitro conditions. Twenty-one litre-plastic jars were used to conduct 4 replications over 75 days. The results showed that solution temperature, pH and Eh were suitable for biogas production. More than 50% of the obtained CH4 was formed within 17–42 days after incubation. The maximum daily CH4 production was 0.052 L/gVS, whilst the daily H2S concentration was low, with a maximum value of 28 ppm within 14–21 d after incubation. Moreover, the peak of daily biogas production was seen at day 16 with production of 0.12 L/gVS. The results highlight that water lettuce biomass can be potentially used to produce high quality biogas in anaerobic incubation.
Źródło:
Journal of Ecological Engineering; 2022, 23, 6; 182--188
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
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