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Wyszukujesz frazę "Nguyen, T. N." wg kryterium: Autor


Wyświetlanie 1-11 z 11
Tytuł:
Experimental study of hydraulic sweeps in horizontal wells
Badanie możliwości oczyszczania hydraulicznego w otworach poziomych
Autorzy:
Nguyen, T. N.
Miska, S. Z.
Yu, M.
Takach, N. E.
Ahmed, R.
Powiązania:
https://bibliotekanauki.pl/articles/300465.pdf
Data publikacji:
2010
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
otwory poziome
oczyszczanie hydrauliczne
horizontal wells
hydraulic sweeps
Opis:
Drilling fluid sweeps are commonly run in the field to help clean the borehole of cuttings that have not been removed with normal drilling fluid circulation, especially in high angle or extended reach wells where efficient hole cleaning is more difficult to maintain. This study focuses on the use of "conventional" and "enhanced" sweeps in horizontal well bores. Not much information pertaining to the use of drilling fluid sweeps is available in the literature. Furthermore, there has been a lack of agreement as to which types of sweep fluids are most effective. Conventional sweeps most often include high viscosity fluids, high density fluids or a combination of both. In addition to conventional sweep fluids, an attempt was made to use enhanced sweep fluids, in which surfactants are used to attach cuttings to oil droplets that are intentionally introduced to the drilling fluid system. Because of their low density, oil droplets can have the ability to keep cuttings particles in suspension. The use of oil droplets is a new concept in cleaning horizontal and deviated wellbores. This work focuses on experimental analysis of sweep fluids with the goal of quantifying the sweep "efficiency". A small-scale sweep loop (SSL) was mainly used to conduct sweep experiments. Moreover, some experiments were carried out in a field-scale flow loop that operates at low-pressure ambient temperature (LPAT) conditions. Results show that pipe rotation plays a very important role in improving hole cleaning. Particularly, the improvement is substantial with high-viscosity fluids. The rotation of pipe has agitation effect that forces the cuttings particles into the main flow and facilitates the removal process. As anticipated, increasing the flow rate enhances the sweep efficiency or cuttings removal regardless of the drillpipe rotation. Furthermore, the study suggests that with a more rigorous evaluation of sweep efficiency, one can objectively determine the type and frequency of drilling sweep. The results of this study are useful for selection of the optimal sweep fluid.
Płuczki czyszczące są powszechnie stosowane do oczyszczania otworów z pozostałości zwiercin, których nie udało się wynieść na powierzchnię za pomocą tradycyjnych płynów płuczkowych, głównie w przypadku otworów kierunkowych i rozgałęzionych, gdzie możliwość oczyszczenia jest ograniczona. Badania skoncentrowały się na wykorzystaniu konwencjonalnych i ulepszonych systemów czyszczących w otworach kierunkowych. W literaturze niezbyt wiele można znaleźć informacji na ten temat. Co więcej, brak jest zgody co do tego, która płuczka czyszcząca jest najskuteczniejsza. Tradycyjne płuczki czyszczące często zawierają płyny o wysokiej lepkości i/lub gęstości. Ponadto podjęto próbę stworzenia ulepszonych płuczek czyszczących, w których zastosowane surfaktanty mają powodować przyklejanie się zwiercin do drobin oleju, który celowo wprowadzono do systemu płuczkowego. Ze względu na niską gęstość, krople oleju utrzymują zwierciny w zawieszeniu. Zastosowanie kropli oleju to nowa koncepcja oczyszczania otworów horyzontalnych. W artykule skoncentrowano się na przeanalizowaniu płuczek czyszczących mających na celu zwiększenie skuteczności oczyszczania. Do badań z reguły stosowano mały obieg czyszczący SSL (small-scale sweep loop). Niektóre eksperymenty prowadzono na złożu w warunkach niskiego ciśnienia i temperatury otoczenia. Wyniki pokazują, że ruch rur odgrywa istotną rolę w zwiększeniu skuteczności oczyszczania otworu. Służy temu również zastosowanie wysoko lepkich płuczek. Rotacja rur podrywa zwierciny doprowadzając je do głównego strumienia, wspomagając proces oczyszczania. Jak przewidywano, ruch w otworze wzmaga wydajność oczyszczania lub wynoszenia zwiercin, niezależnie od rotacji rur. Z badań wynika, że szacując bardziej rygorystycznie zdolności czyszczące, można obiektywnie określić rodzaj i częstotliwość oczyszczania. Wyniki badań pozwalają na stosowny wybór optymalnego środka czyszczącego.
Źródło:
Wiertnictwo, Nafta, Gaz; 2010, 27, 1--2; 307-331
1507-0042
Pojawia się w:
Wiertnictwo, Nafta, Gaz
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Concrete grade change in the layers of three-layer steel fibre reinforced concrete beams
Autorzy:
Lam, T. Q. K.
Do, T. M. D.
Ngo, V. T.
Nguyen, T. T. N.
Pham, D. Q.
Powiązania:
https://bibliotekanauki.pl/articles/1818828.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
steel fibre concrete
stress-strain
crack
material nonlinear
multi-layer beams
concrete grade
beton
włókno stalowe
naprężenie-odkształcenie
pęknięcie
materiał nieliniowy
belki wielowarstwowe
klasa betonu
Opis:
Purpose: Determine the state of stress-strain, formation and development cracks, three-layer beam diagrams of load-compression stress, load-tension stress, load-vertical displacement relationships with a change in concrete grade. Design/methodology/approach: This paper presents the results of an ANSYS numerical simulation analysis involving stress-strain state and cracking of the steel fiber concrete layers of three-layer reinforced concrete beams with the upper and lower layers. With a cross-section of 150x300 mm, a total span of 2200 mm and an effective length of 2000 mm, the middle is a normal concrete layer. Under two-point loads, all the beam samples were tested. The research simulated three-layer concrete beams in different layers of beams with a change in concrete grade, and compared with and without the use of steel fibers in layers of concrete beams, including the nonlinearity of the material considered. Findings: A diagram of the formation and development of cracks in three-layer concrete beams has been constructed by the study results, determining the load at which the concrete beams begin to crack, the load at which the concrete beams are damaged. In the middle of three-layer steel fiber reinforced concrete beams, load-compression stress, loadtension stress, load-vertical displacement relationships are established. Study results show that these three-layer concrete beams appear to crack earlier than in other cases in cases 2 and 3, but the beam bearing capacity is damaged at 67 kN, the earliest in case 3. And case 6 at 116 kN is the latest. The effects of case 1 and case 3 are small compared with and without the use of steel fibers in cases, while the effects of case 5 and case 6 are very high. Research limitations/implications: The research focuses only on the change of concrete grade in the layers, but the input parameters affecting three-layer steel fiber concrete beams have not been researched, such as the number of tensile steel bars, tensile steel bar diameter, steel fiber content in concrete, thickness variation in three-layer concrete beam layers, etc. Practical implications: Provides a result of experimental study and ANSYS numerical simulation in multi-layer steel fiber concrete beams. Originality/value: The analysis of multi-layered steel fiber concrete beams using experimental and simulation methods shows that other parameters influencing the beams will continue to analysis the working stages of three-layer beams.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2020, 102, 1; 16--29
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A model for the inverse 1-median problem on trees under uncertain costs
Autorzy:
Nguyen, K. T.
Chi, N. T. L.
Powiązania:
https://bibliotekanauki.pl/articles/254814.pdf
Data publikacji:
2016
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
location problem
uncertain variable
inverse optimization problem
tree
Opis:
We consider the problem of justifying vertex weights of a tree under uncertain costs so that a prespecified vertex become optimal and the total cost should be optimal in the uncertainty scenario. We propose a model which delivers the information about the optimal cost which respect to each confidence level α ∈ [0,1]. To obtain this goal, we first define an uncertain variable with respect to the minimum cost in each confidence level. If all costs are independently linear distributed, we present the inverse distribution function of this uncertain variable in [formula]time, where n is the number of vertices in the tree.
Źródło:
Opuscula Mathematica; 2016, 36, 4; 513-523
1232-9274
2300-6919
Pojawia się w:
Opuscula Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A method for learning scenario determination and modification in intelligent tutoring systems
Autorzy:
Kozierkiewicz-Hetmańska, A.
Nguyen, N. T.
Powiązania:
https://bibliotekanauki.pl/articles/907820.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
system e-learningowy
nauczanie zdalne
inteligentny system uczący
e-learning system
intelligent tutoring system
learning scenario
personalization
Opis:
Computers have been employed in education for years. They help to provide educational aids using multimedia forms such as films, pictures, interactive tasks in the learning process, automated testing, etc. In this paper, a concept of an intelligent e-learning system will be proposed. The main purpose of this system is to teach effectively by providing an optimal learning path in each step of the educational process. The determination of a suitable learning path depends on the student's preferences, learning styles, personal features, interests and knowledge state. Therefore, the system has to collect information about the student, which is done during the registration process. A user is classified into a group of students who are similar to him/her. Using information about final successful scenarios of students who belong to the same class as the new student, the system determines an opening learning scenario. The opening learning scenario is the first learning scenario proposed to a student after registering in an intelligent e-learning system. After each lesson, the system tries to evaluate the student's knowledge. If the student has a problem with achieving an assumed score in a test, this means that the opening learning scenario is not adequate for this user. In our concept, for this case an intelligent e-learning system offers a modification of the opening learning scenario using data gathered during the functioning of the system and based on a Bayesian network. In this paper, an algorithm of scenario determination (named ADOLS) and a procedure for modifying the learning scenario AMLS with auxiliary definitions are presented. Preliminary results of an experiment conducted in a prototype of the described system are also described.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2011, 21, 1; 69-82
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cultural characteristics and cordycepin production of some Cordyceps militaris strains under artificial cultivation conditions
Autorzy:
Nguyen, L.T.
Le, V.V.
Nguyen, B.T.T.
Ngo, N.X.
Nguyen, H.T.T.
Nguyen, Q.D.
Mulla, S.
Powiązania:
https://bibliotekanauki.pl/articles/2096987.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Cordyceps militaris
mycelial
fruiting body
cordycepin
Opis:
Cordyceps militaris, a precious medical mushroom, has attracted wide attention in industrial fields. Currently, the degeneration phenomenon of C. militaris commercial strains is amongst the major challenges for cultivation at the industrial scale. The screening for superior strains with high yield and medicinal value is considered a realistic approach to overcome degeneration problems. In the present study, the mycelial growth, primordia formation, yield performance, and cordycepin content of five strains (DT1, DT2, DT3, DT4, and DT5) under artificial cultivation conditions were investigated. All strains showed mycelial growth on SDAY and liquid medium. The strains were successfully cultivated in brown rice medium and required 18 (strain DT3) to 25 days (strain DT5) to form primordia. Additionally, morphological characteristics of fruiting bodies varied among the strains. Strains DT4 and DT3 exhibited the highest fruiting body length with 74.23 ± 5.13 mm and 72.63 ± 2.62 mm, respectively whereas the highest diameter was recorded for strains DT1 (4.05 ± 0.18 mm) and DT2 (3.63 ± 0.12 mm). Of note, among the investigated strains, strain DT3 exhibited the highest biological efficiency (8.95 ± 0.07%) and cordycepin content (1.68 mg/g). Therefore, strain DT3 could be selected as a potential strain for commercial cultivation.
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2020, 101, 2; 135-145
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Separator taśmowy - modyfikacja stołów taśmowych typu Vanner zastosowana w Wietnamie
Belt separator – Vanner type separators modification introduced in Vietnam
Autorzy:
Mijał, W.
Nguyen, N.P.
Pham, V.L.
Tran, T.T
Phung, T.T.
Pham, T.H.
Nguyen, H.S.
Powiązania:
https://bibliotekanauki.pl/articles/166768.pdf
Data publikacji:
2018
Wydawca:
Stowarzyszenie Inżynierów i Techników Górnictwa
Tematy:
separator taśmowy
separator typu Vanner
węgiel kamienny
wzbogacanie węgla
próby wzbogacania
górnictwo wietnamskie
belt separator
Vanner type separator
hard coal
coal beneficiation
beneficiation tests
Vietnam’s mining industry
Opis:
Separatory typu Vanner były stosowane głównie do wzbogacania rud takich jak: miedź, ołów, złoto itp.. Konstrukcja tego urządzenia była nietypowa, gdyż był to stół taśmowy, na którym następował rozdział materiału, podobnie jak na klasycznym stole koncentracyjnym. Urządzenie o podobnej konstrukcji jest stosowane do przeróbki węgla kamiennego w wietnamskim przemyśle wydobywczym. Hanoi University of Mining and Geology przeprowadzał wiele testów dla zastosowania tego urządzenia, a w niniejszym artykule zostanie przedstawiona część wyników, jakie uzyskiwano podczas projektowania węzła technologicznego dla węgla płukanego w zakładach Vang Danh i Uong Bi o uziarnieniu 3-20 mm.
Vanner type separators were mainly used to enrich ores such as copper, lead, gold, etc. The construction of this device was atypical, because it was a belt table on which the material was separated like on a classic concentration table. A device of similar construction is used for processing hard coal in the Vietnam’s mining industry. Hanoi University of Mining and Geology has carried out many tests for the use of this device, and this paper presents some of the results obtained during the design of the technological node for the rinsed coal at the Vang Danh and Uong Bi plants with a grain size of 3-20 mm.
Źródło:
Przegląd Górniczy; 2018, 74, 5; 42-47
0033-216X
Pojawia się w:
Przegląd Górniczy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Induction, growth and paclitaxel content of needle- and petiole-derived calli in Himalayan yew (Taxus wallichiana Zucc.) under light-emitting diodes
Autorzy:
Nhut, D.T.
Nguyen, P.L.H.
Don, N.T.
Hien, N.T.T.
Huy, N.P.
Nam, N.B.
Vinh, B.T.
Luan, T.C.
Powiązania:
https://bibliotekanauki.pl/articles/19361.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Źródło:
Acta Biologica Cracoviensia. Series Botanica; 2014, 56, 2
0001-5296
Pojawia się w:
Acta Biologica Cracoviensia. Series Botanica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization of Lycopene Extraction from Tomato Pomace and Effect of Extract on Oxidative Stability of Peanut Oil
Autorzy:
Tran, Dinh T.
Nguyen, Lan T.
Nguyen, Cuong N.
Hertog, Maarten L.
Nicolaï, Bart
Picha, David
Powiązania:
https://bibliotekanauki.pl/articles/16538548.pdf
Data publikacji:
2023-07-05
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
Antioxidant
Response surface methodology
Optimization
Lycopene
Extraction
Peanut oil stability
Opis:
Lycopene, the pigment principally responsible for the red color of tomatoes, is well-known for its strong antioxidant property and substantial health benefits. In this study, the optimal combination of factors for lycopene extraction from tomato pomace was identified using response surface methodology. The best practically feasible results maximizing both lycopene yield and antioxidant activity of the extract were obtained by applying a ratio of ethyl acetate to tomato waste of 35:1 (v/w), at a temperature of 55ºC for 100 min of extraction. The extract was then added to the peanut oil to evaluate its oxidative stability during 60 days of storage at 40ºC. It was shown that the addition of 2 g extract/kg oil offered the lowest level of peroxide value, p-anisidine value, and total oxidation value, followed by the oils with 50 mg butylated hydroxytoulene/kg oil and 1 g extract/kg oil, indicating the effect of lycopene-rich extract on enhancing the oxidative stability of peanut oil. The results in this study suggest that incorporation of extract rich in lycopene from tomato waste products may be an effective method to reduce oxidation and extend the shelf-life of peanut and other vegetable oils.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2023, 73, 3; 205-213
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Adsorption and Desorption Characteristics and Purification of Isoflavones from Crude Soybean Extract Using Macroporous Resins
Autorzy:
Tran, Thi N.
Bui, Xuan V.
Loan, Nguyen T.
Anh, Nguyen H.
Le, Truong D.
Truong, Thi M.
Powiązania:
https://bibliotekanauki.pl/articles/2051036.pdf
Data publikacji:
2022-06-09
Wydawca:
Instytut Rozrodu Zwierząt i Badań Żywności Polskiej Akademii Nauk w Olsztynie
Tematy:
soybean isoflavones
macroporous resin
purification
adsorption and desorption characteristics
daidzin
genistin
Opis:
Isoflavones in soybean have been well-known with many health-promoting effects on humans. This study aimed to purify isoflavones from the crude soybean extract by the static adsorption/desorption process on macroporous resins. A screening test of four commercial resins: D101, AB-8, Amberlite(R) XAD4, and Diaion HP20 according to their adsorption/desorption characteristic for isoflavones was investigated. All four resins showed high adsorption and desorption characteristics in which D101 resin was chosen as the most suitable resin for purifying isoflavones. Compositional analysis showed that daidzin and genistin were the main isoflavones in the crude soybean extract. The adsorption isotherms data of total isoflavones, daidzin, and genistin fitted well with the Langmuir model with R2>0.98. The dynamic adsorption conditions for the purification process of isoflavones on the D101 resin-packed column were selected at the bed volume (BV) of 200 mL, feed volume of 3.75 BV, and flow rate of 1.5 BV/h. The dynamic desorption was carried out with the elution solution of 70% (v/v) ethanol, elution volume of 2.5 BV, and flow rate of 1 BV/h. The total isoflavone content in the purified extract was 8.70-fold higher than its initial content in the crude soybean extract with a recovery yield of nearly 80%. The study results reveal a strong possibility for large-scale production of isoflavones for further application in functional food products or pharmaceutical products.
Źródło:
Polish Journal of Food and Nutrition Sciences; 2022, 72, 2; 183-192
1230-0322
2083-6007
Pojawia się w:
Polish Journal of Food and Nutrition Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of changes in the growth and chemical constituents of Anoectochilus formosanus Hayata grown under hydroponic conditions
Autorzy:
Nguyen, H.C.
Nhu, T.Q.M.
Dung, P.V.
Hieu, N.D.
Tuan, T.T.
Huyen, P.X.
Truong, D.-H.
Powiązania:
https://bibliotekanauki.pl/articles/80522.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Anoectochilus formosanus
medicinal plant
mineral nutrition
hydroponic cultivation
chemical constituent
antioxidant activity
phytochemical screening
alkaloid content
flavonoids
glycoside
terpenoid
steroid
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2018, 99, 4
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Design of water supply networks for water transfer to the urban area Case study: Balikpapan city
Autorzy:
Huy, Dinh T.N.
Dwijendra, Ngakan K.A.
Poltarykhin, Andrey
Suksatan, Wanich
Nahi, Nooraldeen S.
Mahmudiono, Trias
Hai, Nguyen T.
Kadhim, Mustafa M.
Singh, Krishanveer
Ahmed, Alim A.A.
Powiązania:
https://bibliotekanauki.pl/articles/2174373.pdf
Data publikacji:
2022
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
network design
water distribution
water shortage
water supply network
water transmission
Opis:
The growing population and the development of industries in all countries of the world have created a very important and complex issue for water supply to cities. Today, many parts of the world are facing the problem of water shortage and this problem cannot be easily solved. In addition to the proper use of water resources and preventing the loss of natural water, the establishment of regional water supply networks is effective in meeting the future needs of the people. A water distribution network (water supply network) is a set of interconnected pipelines used to transport and distribute water in a complex. In designing the water distribution network, factors such as the type of water distribution network, water pressure, water velocity, design flow, minimum pipe diameter, pipe material and many other factors should be considered. In this study, we have tried to design the water supply network of a part of Balikpapan city in Indonesia. The design method led to the determination of pressure values in the connection nodes, pipe diameters, flow rate and velocity in the pipes. All the existing criteria are considered in the design of the water supply network. Although this study has been implemented for a specific study area, it can be of great help to designers in designing the water supply network.
Źródło:
Journal of Water and Land Development; 2022, 54; 251--254
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-11 z 11

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