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Tytuł:
Travelling wave solutions of the non-linear wave equations
Autorzy:
Haider, Jamil A.
Rahman, Jamshaid U.
Zaman, Fiazud D.
Gul, Sana
Powiązania:
https://bibliotekanauki.pl/articles/2204690.pdf
Data publikacji:
2023
Wydawca:
Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej
Tematy:
nonlinear evolution problems
coupled equations
Jacobi elliptic functions
periodic solutions
Opis:
This article focuses on the exact periodic solutions of nonlinear wave equations using the well-known Jacobi elliptic function expansion method. This method is more general than the hyperbolic tangent function expansion method. The periodic solutions are found using this method which contains both solitary wave and shock wave solutions. In this paper, the new results are computed using the closed-form solution including solitary or shock wave solutions which are obtained using Jacobi elliptic function method. The corresponding solitary or shock wave solutions are compared with the actual results. The results are visualised and the periodic behaviour of the solution is described in detail. The shock waves are found to break with time, whereas, solitary waves are found to be improved continuously with time.
Źródło:
Acta Mechanica et Automatica; 2023, 17, 2; 239--245
1898-4088
2300-5319
Pojawia się w:
Acta Mechanica et Automatica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Towards the propagation of a critically endangered tree species Anisoptera scaphula
Autorzy:
Hossain, M.A.
Ferdous, J.
Rahman, M.A.
Azad, M.A.K.
Shukor, N.A.A.
Powiązania:
https://bibliotekanauki.pl/articles/41522.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
propagation
endangered species
tree
Anisoptera scaphula
Dipterocarpaceae
seed
sowing position
germination percentage
rooting ability
Opis:
Anisoptera scaphula (Roxb.) Kurz, the tallest tree species in Bangladesh, is critically endangered worldwide due to its poor natural regeneration. This study describes the appropriate regeneration technique for A. scaphula through seed germination and clonal propagation by stem cutting. The fastest and highest germination percentage (65) was observed in dewinged seeds sown inverted orientation with half buried position (T10) followed by dewinged seeds (62.5%) sown horizontally in full buried (T7) and delayed germination with lowest percentage (15) was in control (T0). Optimum initial growth was also shown when seedlings were developed from the seeds under T7. Both winged and dewinged seeds sown vertically in full buried or half buried position produced curved seedlings. However, dewinged seeds sown in horizontal or inverted (winged side down) position produced otherwise i.e., straight seedlings. The highest rooting percentages (63%) and maximum number of root (4.8) per cutting were obtained when one node cuttings treated with 0.8% IBA solution followed by 0.4% IBA in turn affecting for better survival and growth of rooted cuttings in the nursery conditions.
Źródło:
Dendrobiology; 2014, 71
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Thin and Rectangular Die Bond Pick-Up Mechanism to Reduce Cracking During the Integrated Circuit Assembly Process
Autorzy:
Rahman, Ahmad R. A.
Nayan, Nazrul Anuar
Powiązania:
https://bibliotekanauki.pl/articles/102963.pdf
Data publikacji:
2020
Wydawca:
Stowarzyszenie Inżynierów i Techników Mechaników Polskich
Tematy:
die attachment
miniaturization
integrated circuit
packaging process
mocowanie matrycy
miniaturyzacja
układ scalony
proces pakowania
Opis:
The demand for small, thin, and lightweight electronic devices is increasing. More advanced design and assembly processes of electronic packaging technology have developed to fulfill this need. The critical processes in semiconductor packaging involved in meeting the ever increasing demands of technology include wafer back grinding, dicing, and die attachment. With low die thickness, the risk of die failure, which can cause functional damage, is high. In the die attachment process, the pin ejector causes an impact during the pick and place process. Those effects can result in a micro indentation or micro crack under the die and would be the weak point throughout the entire process. This study designed and evaluated an ejector system for the die attachment process. The proposed method uses a static pole heated inside the cavity for the platform to die before being ejected. Vacuum stabilizes the die suction. Moreover, heat softens the sawing tape and weakens the die adhesion. For die selection during the die attachment process, the results show that the critical die crack problem for a thin and rectangular die is solved using the proposed method. In summary, the packaging of semiconductors has advanced to accommodate the pick-up technology solution in relation to the challenging material needed for the current miniaturization market trend and demand.
Źródło:
Advances in Science and Technology. Research Journal; 2020, 14, 3; 57-64
2299-8624
Pojawia się w:
Advances in Science and Technology. Research Journal
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The youngest ctenocystoids from the Upper Ordovician of the United Kingdom and the evolution of the bilateral body plan in echinoderms
Autorzy:
Rahman, I.A.
Stewart, S.E.
Zamora, S.
Powiązania:
https://bibliotekanauki.pl/articles/945494.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Paleobiologii PAN
Tematy:
Echinodermata
Ctenocystoidea
evolution
bilateral symmetry
Ordovician
ctenocystoid
Upper Ordovician
United Kingdom
bilateral body
echinoderm
Opis:
During the early Palaeozoic, echinoderm body plans were much more diverse than they are today, displaying four distinct types of symmetry. This included the bilateral ctenocystoids, which were long thought to be restricted to the Cambrian. Here, we describe a new species of ctenocystoid from the Upper Ordovician of Scotland (Conollia sporranoides sp. nov.). This allows us to revise the genus Conollia, which was previously based on a single poorly-known species from the Upper Ordovician of Wales (Conollia staffordi). Both these species are characterized by a unique morphology consisting of an elongate-ovoid body covered in spines, which clearly distinguishes them from their better-known Cambrian relatives; they are interpreted as infaunal or semi-infaunal burrowers from deep-water environments. This indicates that the ctenocystoid body plan was not fixed early in the evolution of the group, and they most likely modified their structure as an adaptation to a new mode of life in the Ordovician.
Źródło:
Acta Palaeontologica Polonica; 2015, 60, 1; 39-48
0567-7920
Pojawia się w:
Acta Palaeontologica Polonica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Schwarz-Pick theorem and its applications
Autorzy:
Qazi, M. A.
Rahman, Q. I.
Powiązania:
https://bibliotekanauki.pl/articles/747151.pdf
Data publikacji:
2011
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Tematy:
Bernstein’s inequality
functions of exponential type in a half-plane
rational functions
Schwarz-Pick theorem
Opis:
Various derivative estimates for functions of exponential type in a half-plane are proved in this paper. The reader will also find a related result about functions analytic in a quadrant. In addition, the paper contains a result about functions analytic in a strip. Our main tool in this study is the Schwarz-Pick theorem from the geometric theory of functions. We also use the Phragmen-Lindelof principle, which is of course standard in such situations.
Źródło:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica; 2011, 65, 2
0365-1029
2083-7402
Pojawia się w:
Annales Universitatis Mariae Curie-Skłodowska, sectio A – Mathematica
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study of the Variations in the Vertical and Horizontal Distribution of Heavy Sand Minerals in the Hilla River Sediments
Autorzy:
Hameed, Iman A.
Rahman, Haleema Abdul Jabbar Abdul
Anmar, Alsaadi
Powiązania:
https://bibliotekanauki.pl/articles/27323812.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
sediment
heavy minerals
specific gravity
Opis:
This study was conducted to investigate the effect of the Hilla River sediments on the heterogeneity of the distribution of heavy sand minerals for the fine and very fine sand classes as well as for the surface and subsurface layers. The results showed that the heavy sand minerals that were determined according to the specific gravity of each mineral and the specific gravity of the particles of minerals identified in the soils under study ranged between (2.5–4.5) and were divided into four groups in terms of the specific gravity. The first group included each of the minerals (Mica and Chlorite) of low specific gravity, while the second group contains (Pyroxene, Amphibole, Epidote Group). The third group includes minerals (Tourmaline and Garnet, Staurolite and Kyanite) and the two groups are classified as minerals of medium-specific gravity; in turn, the fourth group contains minerals of high specific gravity, namely (Zircon, Rutile and Opaques). As a result, the most important factors affecting the sedimentation, sorting and sedimentation processes are the conveyor’s speed, load capacity, the size of the separation particles and their specific gravity. The complete mismatch of the horizontal distribution of the minerals of one group is due to the varying ranges of the specific gravity of the minerals within the general range of specific gravity.
Źródło:
Journal of Ecological Engineering; 2023, 24, 7; 318--330
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Structured Analysis of Nanostructured Zinc Oxide (ZnO) Thin Films Deposited by Sol-Gel
Autorzy:
Hussin, Rosniza
Hanafi, F.
Rashid, R. A.
Harun, Z.
Kamdi, Z.
Ibrahim, S. A.
Ainuddin, A. R.
Rahman, W.
Leman, A. M.
Powiązania:
https://bibliotekanauki.pl/articles/2134100.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
sol-gel
zinc oxide
ZnO
thin films
nanostructured
Opis:
In this work, zinc oxide (ZnO) thin films are deposited on glass substrate using the sol-gel spin coating technique. The effect of annealing temperature on structural properties was investigated. The ZnO sol-gel was produced from zinc acetate dehydrate as the starting material with iso-propanol alcohol as the stabilizer. The ratio was controlled, distilled water and diethanolamine as the solvent mixing on a magnetic stirrer for an hour under constant heat of 60°C. The ZnO thin film was deposited using the spin coating technique with the speed of 3000 rpm for 30 minutes before the sample undergoes pre-heat in the oven at the temperature of 100°C for 10 minutes. The sample was annealing in the furnace for an hour at 200°C, 350°C, and 500°C. The X-ray diffraction (XRD) analysis confirms that hexagonal wurtzite structure with zincite and zinc acetate hydroxide hydrate composition. The thin films surface roughness was analyzed using an atomic force microscope (AFM) and scanning electron microscope (SEM) for surface morphology observation.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 1055--1060
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Stack Parameters Effect on the Performance of Anharmonic Resonator Thermoacoustic Heat Engine
Wpływ parametrów stosu na osiągi anaharmonicznego rezonatora termo akustycznej maszyny cieplnej
Autorzy:
Nouh, M. A
Arafa, N
Abdel-Rahman, E
Powiązania:
https://bibliotekanauki.pl/articles/140035.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
thermoacoustic
stack
anharmonic
resonator
engine
optimization
termoakustyka
stos
silnik
rezonator
Opis:
A thermoacoustic heat engine (TAHE) converts heat into acoustic power with no moving parts. It exhibits several advantages over traditional engines, such as simple design, stable functionality, and environment-friendly working gas. In order to further improve the performance of TAHE, stack parameters need to be optimized. Stack’s position, length and plate spacing are the three main parameters that have been investigated in this study. Stack’s position dictates both the efficiency and the maximum produced acoustic power of the heat engine. Positioning the stack closer to the pressure anti-node might ensure high efficiency on the expense of the maximum produced acoustic power. It is noticed that the TAHE efficiency can further be improved by spacing the plates of the stack at a value of 2.4 of the thermal penetration depth, ςk . Changes in the stack length will not affect the efficiency much as long as the temperature gradient across the stack, as a ratio of the critical temperature gradient Γ, is more than 1. Upon interpreting the effect of these variations, attempts are made towards reaching the engine’s most powerful operating point.
Termoakustyczna maszyna cieplna (TAHE) przekształca ciepło w energie akustyczna bez użycia części ruchomych. W porównaniu z maszynami tradycyjnymi ma ona szereg zalet, takich jak prosta konstrukcja, stabilność działania oraz wykorzystanie gazów przyjaznych dla środowiska. W celu dalszej poprawy osiągów maszyny TAHE należy zoptymalizować parametry stosu (zespołu wąskich kanałów miedzy płytami wymiennika ciepła). Trzema głównymi parametrami analizowanymi w przedstawionej pracy są pozycja stosu, długości, odstęp między płytami. Pozycja stosu decyduje zarówno o sprawności jak maksymalnej mocy akustycznej wytwarzanej przez maszynę cieplną. Umieszczenie stosu bliżej strzałki fali stojącej może zapewnić większą sprawność kosztem maksymalnej wytwarzanej mocy akustycznej. Stwierdzono, że dalsza poprawa sprawności maszyny TAHE może być osiągnięta gdy zastosuje się odstęp płyt stosu równy 2,4 cieplnej głębokości wnikania, k . Zmiany długości stosu nie maja wielkiego wpływu na sprawność tak długo, jak stosunek krytycznego gradientu cieplnego jest większy od 1. Na podstawie interpretacji efektów tych zmian podjęto wysiłki dla uzyskania najlepszych osiągów maszyny.
Źródło:
Archive of Mechanical Engineering; 2014, LXI, 1; 115-127
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Serodiagnosis of Toxoplasmosis using Lateral Flow Chromatographic Immunoassay among Animals and Humans in Sunsari District of Nepal
Autorzy:
Sah, Ramesh Prasad
Talukder, Md Hasanuzzaman
Rahman, A. K. M. Anisur
Powiązania:
https://bibliotekanauki.pl/articles/1167051.pdf
Data publikacji:
2018
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Animals
Nepal
human
seroprevalence
toxoplasmosis
Opis:
Toxoplasmosis is a cosmopolitan parasitic zoonosis, infecting human and other warm blooded animals worldwide. This disease has economic importance in regard to animal reproduction, and it leads to abortions and neonatal complications in humans. This study was carried out to determine the seroprevalence of Toxoplasma gondii in sheep, cattle, cats and human in Inaruwa and surrounding areas of Sunsari district, Nepal. Altogether 336 blood samples, of which 50 from sheep, 92 from cattle, 44 from cats and 150 from human were collected and tested immediately using lateral flow chromatographic immunoassay (Toxo IgG/IgM Combo Rapid test®). Associated biometric information such as age, sex, pregnancy status, occupation, association with cat was recorded and analyzed to determine the association of risk factors with the disease. Data were analyzed using R 3.2.2 (The R foundation for Statistical Computing, 2015). Seroprevalence of toxoplasmosis was detected 12.00% (95% CI: 4.53- 24.31%) in sheep, 8.70% (95% CI: 3.83- 16.42%) in cattle, 36.36% (95%CI: 22.41- 52.23%) in cats and 12.67% (95% CI: 7.80- 19.07%) in human. In case of human, 31 to 45 years age group were found more susceptible to toxoplasmosis (21.74%, OR: 6.4) in comparison to 21 to 30 years (10.0%) and up to 20 years (4.17%) age groups. Toxoplasmosis was found highly significantly associated with abortion (58.33%, OR= 15.4, P=0.0001) in human in the tested individuals. Regarding occupation, 20.83% butchers were seropositive followed by farmers (15.52%), housewives (10.0%) and diagnostic lab technicians (8.0%). Female and higher age group showed high prevalence of toxoplasmosis in all studied species. Therefore, this assay is a useful method for the serological screening of toxoplasmosis in different animals and humans.
Źródło:
World Scientific News; 2018, 105; 145-156
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Response of non-linear shock absorbers-boundary value problem analysis
Autorzy:
Rahman, M. A.
Ahmed, U.
Uddin, M. S.
Powiązania:
https://bibliotekanauki.pl/articles/265424.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
amortyzator
tłumik drgań
stabilność
wartość graniczna
shock absorber
untuned vibration damper
frequency ratios
non-linear springs
non-linear dampers
stability
boundary value problem
multisegment method of integration
Opis:
A nonlinear boundary value problem of two degrees-of-freedom (DOF) untuned vibration damper systems using nonlinear springs and dampers has been numerically studied. As far as untuned damper is concerned, sixteen different combinations of linear and nonlinear springs and dampers have been comprehensively analyzed taking into account transient terms. For different cases, a comparative study is made for response versus time for different spring and damper types at three important frequency ratios: one at r = 1, one at r > 1 and one at r <1. The response of the system is changed because of the spring and damper nonlinearities; the change is different for different cases. Accordingly, an initially stable absorber may become unstable with time and vice versa. The analysis also shows that higher nonlinearity terms make the system more unstable. Numerical simulation includes transient vibrations. Although problems are much more complicated compared to those for a tuned absorber, a comparison of the results generated by the present numerical scheme with the exact one shows quite a reasonable agreement.
Źródło:
International Journal of Applied Mechanics and Engineering; 2013, 18, 3; 793-814
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Removal of Cadmium using Alkaline-Treated Activated Carbon from Leucaena Leucocephala Biomass
Autorzy:
Ibrahim, W. M. H. W.
Sulaiman, Nurul Syuhada
Amini, Mohd Hazim Mohammad
Kadir, W. R. A.
Mohamed, Mazlan
Ramle, Sitti Fatimah Mhd
Bilgin, Ugur
Rahman, Wan
Powiązania:
https://bibliotekanauki.pl/articles/2125550.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
activated carbon
cadmium
Leucaena leucocephala
adsorption
Opis:
Water contamination that caused by heavy metals is a very common phenomenon in the industrial age. One of the popular way to treat metal contaminated water is by adsorption process using activated carbon as the adsorbent. This paper works on producing activated carbon by chemical means with impregnation ratios of NaOH:char (w/w) was predetermined at 1:1 (ACT1-1), 2:1 (ACT2-1) and 3:1 (ACT3-1) under activation temperature of 700°C. Considering the Leucaena leucocephala is a wildly, easy and fast grown species, with the availability throught the year, it was chosen to be used as the precursor. The properties of these activated carbons and its potential for cadmium removal from aqueus solution was analyzed. It was found that the highest surface area was recorded at 662.76 m²/g. Four parameters were studied which are contact time, the effect of pH, initial concentration of adsorbate and temperature. The equilibrium time was achieved in 40 min treatment at initial concentrations of 30 mg/l. The adsorbent exhibited good sorption potential for cadmium at pH 8.0 and equilibrium temperature of 30℃. Based on the results, this study had proved that activated carbon from Leucaena leucocephala biomass have the good potential to be used for removal of cadmium from wastewater.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 1033--1036
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Properties of~Rf Plasma Nitrided Silicon Thin Films at Different Rf Plasma Processing Powers
Autorzy:
Mohamed, S.
Raaif, M.
Abd El-Rahman, A.
Shaaban, E.
Powiązania:
https://bibliotekanauki.pl/articles/1493713.pdf
Data publikacji:
2011-09
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
81.15.Dj
61.05.cp
73.61.-r
78.66.-w
Opis:
Nitrided surfaces and composition gradients in thin films exhibit interesting mechanical, electrical and optical properties. Therefore, silicon (Si) thin films were prepared by electron beam evaporation and nitrided by an inductively coupled rf plasma. The effects of successive plasma processing power on structural and optical properties as well as electrical resistivity were examined by different characterization techniques. The Si thin films were transformed gradually into nitrides compound thin films and the amount of nitrogen in the film increased with increasing the rf processing power. The Si nitrided films showed structural, optical and electrical properties that depend on the nitriding power. Increasing the rf plasma processing power caused amorphization, reduced the thickness, increased transmittance, increased resistivity and decreased the reflectance of the Si films. The electrical resistivity increased about eight orders of magnitude when the sample nitrided at 500 W. Different optical band gap were determined indicating the presence of different competing phases in the same film. The decrease in refractive index with plasma treatment power is attributed to the possible change in the bucking density as well as to the increase in the band gap.
Źródło:
Acta Physica Polonica A; 2011, 120, 3; 552-557
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Propagation of threatened climber species Entada rheedii Spreng. – a medicinal plant with extremely thick and hard seed coat
Autorzy:
Hossain, M.A.
Dey, J.
Rahman, M.A.
Powiązania:
https://bibliotekanauki.pl/articles/2078264.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Instytut Dendrologii PAN
Tematy:
Entada rheedii
germination potential
growth performance
pre-sowing treatments
rooting abil-
ity
rooted cuttings
Opis:
The study explored propagation techniques of Entada rheedii Spreng., a threatened medicinal climber species with extremely hard seed coat. Propagation trials included both pre-sowing treatments of seeds for germination and clonal propagation by stem cutting. Pre-sowing treatments included (a) soaking of both cut (notched) and uncut (intact) seeds in water for 0 h, 24 h, 48 h, and 72 h and (b) immersion of intact seeds in 5% acetone solution for 5 min, 10 min, and 20 min before sowing in germination media in polybags. On the other hand, stem cutting involved treating the summer or autumn cuttings with 0%, 0.4%, and 0.8% IBA solution before rooting in non-mist propagator. Notched seeds soaked in water for 48 h showed the fastest seed germination with the highest germination percentages (73.3) and better seedling growth in terms of plant height, collar diameter, leaf number and total dry mass followed by notched seeds soaked in water for 72 h. The slowest germination and the lowest germination percentage (3.3), as well as the poorest growth performance was for intact seeds without any treatment. The highest rooting percent- age with maximum number of roots (36.6) was obtained from the summer cuttings treated with 0.4% IBA solution followed by autumn cuttings with 0.8% IBA and the lowest (43.3% and 8.3 roots) was for summer cuttings in control. The factors also dictated the survival and growth performance of rooted cuttings in the nursery conditions. The outcomes of these trials i.e., notched seeds soaking in water for 48 h will help to enhance the propagation of this valuable medicinal plant species.
Źródło:
Dendrobiology; 2021, 85; 92-104
1641-1307
Pojawia się w:
Dendrobiology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parametric optimisation of microhardness on heat-treated electroless Ni-YSZ cermet coating
Autorzy:
Bahiyah Baba, N.
Ghazali, A. S.
Abdul Rahman, A. H.
Sharif, S
Powiązania:
https://bibliotekanauki.pl/articles/2172165.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
full factorial
electroless
Ni-YSZ
cermet
coating
microhardness
treating temperature
treating time
silnia
bezprądowy
powłoka
mikrotwardość
temperatura obróbki
czas obróbki
Opis:
Purpose The paper discusses the parametric optimisation of the electroless Ni-YSZ cermet coating microhardness upon heat treatment. Heat treatment is a process to increase the mechanical properties of the electroless nickel coating and it can be enhanced by manipulating its parameters. Parametric optimisation is conducted by the design of experiment full factorial 3x3 with 27 runs. Treating temperature, treating time and ceramic particle size parameters at 3-level are evaluated using statistical tool ANOVA in Minitab20. Design/methodology/approach Ni-YSZ cermet coating is deposited onto a high-speed steel substrate using the electroless nickel co-deposition method. The temperature and time were varied in a range of 300-400oC and 0-2 hours respectively. The microhardness measurements were carried out using a Vickers microhardness tester (Shimadzu) according to ISO 6507-4. The surface characterisation was analysed using Cambridge Stereoscan 90 Scanning Electron Microscope (SEM) coupled with Energy Dispersive X-ray Analysis (EDXA). Findings The optimum condition in obtaining high microhardness on Ni-YSZ cermet coating is evaluated by statistical tool ANOVA in Minitab20 software. It is found that the most significant parameter for high microhardness is at the treating temperature of 400oC followed by treating time at 2 hours using nano-sized YSZ particles. The ceramic particle size is found not a significant parameter in obtaining a high microhardness, however it has effect on interaction between treating temperature and treating time. Research limitations/implications The paper only limits to the optimisation condition of microhardness on Ni-YSZ cermet coating hardness property by varying heat treatment parameters. Practical implications The optimisation condition obtained might only applicable to the electroless Ni-YSZ cermet coating with similar electroless nickel solution and treatments. Originality/value The value of this work is the heat treatment parametric optimisation to obtain high microhardness on electroless Ni-YSZ cermet coating by using the design of experiment 3-level full factorial.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2022, 112, 1; 33--41
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimizing Dry Ultrafine Grinding of Talc in Attritor Mill
Optymalizacja ultradrobnego mielenia talku na sucho w młynie Attritor
Autorzy:
El-Mofty, Salah E.
Elbendari, A. M.
El-Midany, A. A.
Abdel-Rahman, M. K.
Powiązania:
https://bibliotekanauki.pl/articles/27323304.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Przeróbki Kopalin
Tematy:
dry grinding
ultra-fine grinding
attritor mill
statistical design
talc
mielenie na sucho
mielenie ultradrobne
młyn attritor
projektowanie statystyczne
talk
Opis:
In this work, the parameters affecting the dry grinding of talc in the attritor mill were investigated. The attritor was tested with its initial design without balls then with balls as additional grinding media to prepare a feed passing 45 microns. The prepared feed (-45 mm) was used to produce a product with 10 μm or less using statistical design in presence of balls. The presence of balls enhances product fineness. The significance of the studied factors is: stirrer speed>mill filling >grinding time. In addition, the d50 was correlated with studied factors. The mean particle size (d50) as low as 6 μm was obtained at 460 rpm, 20% mill filling, and after 60 min grinding time.
W niniejszej pracy zbadano parametry wpływające na mielenie talku na sucho w młynie Attritor. Attritor został przetestowany w początkowej wersji bez kulek, a następnie z kulkami jako dodatkowym medium mielącym w celu przygotowania nadawy przechodzącej przez 45 mikronów. Przygotowany wsad (-45 mm) został wykorzystany do wytworzenia produktu o uziarnieniu 10 μm lub mniejszym przy użyciu statystycznego projektu w obecności kulek. Obecność kulek zwiększa stopień rozdrobnienia produktu. Znaczenie badanych czynników to: prędkość mieszadła > wypełnienie młyna > czas mielenia. Ponadto d50 był skorelowany z badanymi czynnikami. Średni rozmiar cząstek (d50) tak niski jak 6 μm uzyskano przy 460 obr/min, 20% wypełnieniu młyna i po 60 min mielenia.
Źródło:
Inżynieria Mineralna; 2023, 2; 361--366
1640-4920
Pojawia się w:
Inżynieria Mineralna
Dostawca treści:
Biblioteka Nauki
Artykuł
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