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Tytuł:
Preparation and performance in IR and UV of transparent inorganic polysiloxane coating with dispersed TiO2 on glass substrates
Autorzy:
Saudi, S. A.
Mohd, A. F.
Powiązania:
https://bibliotekanauki.pl/articles/2201066.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
transparent coatings
glass substrate
TiO2 dispersion
IR shielding
UV shielding
ultra-high shearing dispersion
powłoki przezroczyste
podłoże szklane
dyspersja
TiO2
ekranowanie
Opis:
Purpose The aim of the presented work was to develop an economical, transparent coating with dispersed TiO2 dispersion and inorganic polysiloxane resin for glass windows application and to study its effectiveness in filtering IR and UV radiations. Design/methodology/approach Two oligomeric silanes were prepared in different molar ratios to produce inorganic polysiloxane resin. They were tested for their viscosity to reflect the completion of the reaction and form an amide linkage. FTIR was done to support the viscosity result by proving the presence of amide linkages. 10%, 20%, and 30% of compounded TiO2 were successfully dispersed in 0.3% sodium sulfosalicylate (dehydrated ethanol). Each TiO2 concentration was characterized for size distribution and polydispersity index (PDI). Additives solutions of 2-hydroxybenzophenone (HBP) and boron trifluoride (BF3) were also soluted in the same solvent. Glass substrates were coated with the formulations and tested for curing and hardness properties. Windows Energy Profiler (WEP) was used to study the UV, IR, and daylight transmission of the coated glasses. Findings Each inorganic polysiloxane resin showed various viscosity values before reaching a constant state which designates complete formations of amide linkages. Polysiloxane resin with a viscosity value of 30.5 mPa/s was the most ideal to act as a binder. FTIR characterization proved the formation of amide linkages. The particle size distribution of TiO2 recorded the size of 87 nm after dispersion with correlating value of 1 PDI. The fastest drying time of 3 hours was recorded. The pencil hardness test quoted 6H pencil as the hardest pencil grade. WEP analysis of UV, IR, and daylight transmission gives satisfactory results of 0%, 7%, and 61%, respectively. Research limitations/implications Laboratory analysis for viscosity tests often being held off. The test requires the samples to be transferred in a cylinder with an open-air spindle rotation. Samples react with the surrounding environment. Thus, polymerization takes place rapidly, resulting in hardened samples inside the cylinder. The different measure was taken by wrapping the testing area with aluminium foil. This research was conducted under equatorial climate. Practical implications The obtained test results may contribute to the conclusion of transparent TiO2 nano-particles coating on glass substrates for windows application. This can reduce the electricity usage in buildings for artificial cooling to provide indoor thermal comfort. Smart coating formulations have a noticeable effect on filtering harmful solar radiation. Originality/value This study presents the economical and undemanding ways to develop transparent smart coating formulation with superior performance against solar radiation. It is expected to have a bright potential in the architectural industry.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2022, 114, 2; 49--56
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The effect of kenaf loading on kenaf/ABS composites structure and thermal properties
Autorzy:
Mashelmie, S.
Rabiatul Manisah, M.
Bahiyah Baba, N.
Mohd, A.
Powiązania:
https://bibliotekanauki.pl/articles/2172154.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
kenaf fibre
ABS
polymer composites
MFI
TGA
DSC
włókna kenafu
kompozyty polimerowe
wskaźnik szybkości płynięcia
analiza termograwimetryczna
skaningowa kalorymetria różnicowa
Opis:
Purpose Many manufacturers have recently become interested in using fiber-reinforced polymer composites (FRPs) in structural applications. Synthetic fibres, such as carbon and glass fibres, have been commercialised internationally for decades, but they cause environmental issues because synthetic fibres are non-biodegradable and difficult to recycle once they have served their purpose, potentially polluting the environment. Thus, natural fibre composites like kenaf is a possible replacement for synthetic fibre due to their superior physical and mechanical properties. Kenaf appears to be the best candidate for replacing synthetic fibres in order to accomplish the goal of environmental preservation while also displaying excellent properties such as equivalent specific strength, low density, and renewable resources. Design/methodology/approach The kenaf fiber was treated in KOH and added to ABS matrix to produce new composites at different loading (10, 15, 20 and 25 wt.%) by using Two Roll Mill machine. The influence of the fiber on the composites properties was evaluated. The produced material was subjected to SEM, MFI, TGA and DSC analysis. Findings The incorporation of the treated kenaf fiber has an influence on the properties of kenaf/ABS composites. The addition of 10 wt.% kenaf was found to be the best loading with MFI value, initial degradation temperature and glass transition temperature at 0.8208 g/10 min, 322.63°C and 130°C respectively. The fiber was well dispersed in the matrix and shown good adhesion to the ABS. The addition of treated fiber contribute to a reduction in the MFI, improved the thermal stability of the composites and typical effects of Tg of the composite compare to pure ABS. Research limitations/implications The results suggest the need to continue the study in order to further analyse higher kenaf loading and shed more light on the properties of the composites to improve understanding of kenaf/ABS composites. Originality/value Obtained results are a solution to alternative of synthetic fibers, which may contribute to the sustainable development of composites materials industry through the utilization of kenaf fiber with ABS matrix.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2022, 111, 2; 49--56
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Plastic filling simulation comparison analysis of the gating system in injection moulding parameter
Autorzy:
Umor, M. Z.
Mohd, A.
Efendee, A. M.
Khir, M.
Bahiyah Baba, N.
Powiązania:
https://bibliotekanauki.pl/articles/2201029.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
filling simulation
gating system
moulding parameters
symulacja
system bramkowania
parametry wtrysku
Opis:
Purpose: The paper is discussed the anticipation of the simulation software precision with the real moulding process by setting up the distinctive metering stroke separation. Design/methodology/approach: The Inventor CAD software was used to design the product experiment and perform the simulation by applying MoldFlow application to produce the processing parameter defining for the injection moulding machines. Findings: The results predicted by this filling simulation appears reasonable result as compared to the injected product. Prediction analysis given by the software is exceptionally valuable for the injection moulding parameter setting machines which can diminish the time of mould setup and can reduce the trial stage on the production line. Research limitations/implications: The gating system is the most crucial part in injection moulding process and the limitation is to get the accurate filling time and injection pressure to ensure the cavity is fully filled before the material at the gate solidify. Originality/value: Gating system configurations are utilized to optimize the filling conditions of injection moulding parts. This important element was developed for achieving product quality. The utilize of simulation software is exceptionally supportive in the model designing stage to predict the quality and process capacity for the product. This paper presents the filling simulation of the side gate system to the injection moulding parameter.
Źródło:
Journal of Achievements in Materials and Manufacturing Engineering; 2022, 112, 2; 64--69
1734-8412
Pojawia się w:
Journal of Achievements in Materials and Manufacturing Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Formulating delamination-fretting wear failure predictive equation in HAp coated hip arthroplasty using multiple linear regression model
Autorzy:
Nagentrau, M.
Ibrahim, N.H.
Jamian, S.
Mohd Tobi, A.L.
Powiązania:
https://bibliotekanauki.pl/articles/24200558.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
hip arthroplasty
delamination
fretting
HAp
regression
artroplastyka stawu biodrowego
rozwarstwienie
regresja
Opis:
Purpose: Present paper addresses the formulation of delamination-fretting wear failure predictive equation in HAp-Ti-6Al-4V interface of hip arthroplasty femoral stem component using multiple linear regression model. Design/methodology/approach: A finite element computational model utilising adaptive meshing algorithm via ABAQUS/Standard user subroutine UMESHMOTION is developed. The developed FE model is employed to examine effect of different HAp-Ti-6Al-4V interface mechanical and tribological properties on delamination-fretting wear behaviour. The FE result is utilised to formulate predictive equations for different stress ratio conditions using multiple linear regression analysis. Findings: Delamination-fretting wear predictive equations are successfully formulated with significant goodness of fit and reliability as a fast failure prediction tool in HAp coated hip arthroplasty. The robustness of predictive equations is validated as good agreement is noted with actual delamination-fretting wear results. Research limitations/implications: The influence of different mechanical and tribological properties such as delamination length, normal loading, fatigue loading, bone elastic modulus and cycle number under different stress ratio on delamination-fretting wear failure is analysed to formulate failure predictive equations. Practical implications: The formulated predictive equation can serve as a fast delamination-fretting wear failure prediction tool in hip arthroplasty femoral stem component. Originality/value: Limited attempt is done to explore the potential of utilizing multiple linear regression model to predict failures in hip arthroplasty. Thus, present study attempt to formulate delamination-fretting wear failure predictive equation in HAp -Ti-6Al-4V interface of hip arthroplasty femoral stem component using multiple linear regression model.
Źródło:
Archives of Materials Science and Engineering; 2022, 115, 2; 76--85
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Naoh Molar Concentration on Microstructure and Compressive Strength of Dolomite/Fly Ash-Based Geopolymers
Autorzy:
Azimi, Emy Aizat
Salleh, Mohd M. A. A.
Abdullah, Mohd Mustafa Al Bakri
Aziz, Ikmal Hakem A.
Hussin, Kamarudin
Chaiprapa, Jitrin
Vizureanu, Petrica
Yoriya, Sorachon
Nabiałek, Marcin
Wyslocki, Jerzy J.
Powiązania:
https://bibliotekanauki.pl/articles/2125545.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
dolomite/fly ash
geopolymer
NaOH concentration
synchrotron
micro-XRF
Opis:
Dolomite can be used as a source of aluminosilicate to produce geopolymers; however, this approach is limited by its low reactivity. This study analyzes the viability of producing geopolymers using dolomite/fly-ash with sodium silicate and NaOH solutions (at multiple concentrations) by determining the resultant geopolymers’ compressive strengths. The dolomite/fly-ash-based geopolymers at a NaOH concentration of ~22 M resulted in an optimum compressive strength of 46.38 MPa after being cured for 28 days, and the SEM and FTIR analyses confirmed the denser surface of the geopolymer matrix. The synchrotron micro-XRF analyses confirmed that the Ca concentration exceeded that of Si and Mg, leading to the formation of calcium silicate hydrate, which strengthens the resulting geopolymers.
Źródło:
Archives of Metallurgy and Materials; 2022, 67, 3; 993--998
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bio-polishing sludge adsorbents for dye removal
Autorzy:
Zaini, M. A. A.
Norulaina, A.
Mohd Azizi, C. Y.
Powiązania:
https://bibliotekanauki.pl/articles/779794.pdf
Data publikacji:
2016
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
adsorption
adsorbent
bio-polishing sludge
methylene blue
chemical treatment
Opis:
The objective of this work is to evaluate the removal of methylene blue dye by bio-polishing sludge-based adsorbents. The adsorbents were characterized according to the specific surface area, pH upon the treatment and surface functional groups. The adsorption of dye was carried out at room temperature, and the adsorption data were analyzed using the isotherm and kinetics models. The bio-polishing sludge is rich in ash content, and the presence of surface functional groups varied with the treatment strategies. The specific surface area of adsorbents is between 7.25 and 20.8 m2 /g. Results show that the maximum removal of methylene blue by sludge adsorbents was observed to have the following order: untreated sludge (SR) > zinc chloride-treated (SZ) > microwave-dried (SW) = potassium carbonate-treated (SK) > acid-washed (SH). The maximum adsorption capacities for SR and SZ as predicted by the Langmuir model are 170 and 135 mg/g, respectively. Although SR demonstrates a higher maximum removal than SZ, the latter exhibits greater removal intensity and rate constant even at high dye concentration. The bio-polishing sludge is a promising adsorbent for dye wastewater treatment.
Źródło:
Polish Journal of Chemical Technology; 2016, 18, 4; 15-21
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical properties of sugar palm yarn/woven glass fiber reinforced unsaturated polyester composites: effect of fiber loadings and alkaline treatment
Wpływ zawartości włókien i obróbki alkalicznej na właściwości mechaniczne kompozytów z nienasyconej żywicy poliestrowej wzmacnianych włóknem szklanym i włóknem palmy cukrowej
Autorzy:
Mohd Nurazzi, N.
Khalina, A.
Sapuan, S. M.
Ilyas, R. A.
Powiązania:
https://bibliotekanauki.pl/articles/947560.pdf
Data publikacji:
2019
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
glass fiber
hybrid composites
mechanical properties
sugar palm fiber
yarn fiber
unsaturated polyester resin
włókno szklane
kompozyty hybrydowe
właściwości mechaniczne
włókno palmy cukrowej
włókno przędzy
nienasycona żywica poliestrowa
Opis:
In this paper, hybrid sugar palm yarn and glass fiber reinforced unsaturated polyester composites were investigated in relation to the effects of fiber loadings and alkaline treatment on the composite mechanical properties, such as tensile, flexural, impact and compression strength. The composites were fabricated at a weight ratio of matrix to reinforcement of 70 : 30 and 60 : 40, respectively, while the ratio of sugar palm yarn fiber to glass fiber was selected at 70 : 30, 60 : 40 and 50 : 50, respectively. The results revealed that the mechanical properties of the hybrid composites were increased with an increase of glass fiber loading for both 30 wt % and 40 wt % reinforcement content. The alkaline treatment of the sugar palm fibers have advantageous effect on the hybrid composite performance. The overall results indicated that the developed hybrid composites can be used as an alternative material for glass fiber reinforced polymer composites for various structural applications.
Zbadano wpływ zawartości włókien i ich obróbki alkalicznej na właściwości mechaniczne wzmacnianych włóknem szklanym kompozytów nienasyconej żywicy poliestrowej z włóknami palmy cukrowej. Oceniano wytrzymałość kompozytów na rozciąganie, zginanie, uderzenie i ściskanie. Wytworzone kompozyty zawierały 30 oraz 40% mas. włókien, przy stosunku masowym włókien palmy cukrowej do włókien szklanych 70/30, 60/40 i 50/50. Stwierdzono, że wytrzymałość mechaniczna kompozytów hybrydowych zwiększa się ze wzrostem zawartości włókna szklanego, a obróbka alkaliczna włókien palmy cukrowej wywiera korzystny wpływ na właściwości zawierających ją kompozytów hybrydowych. Uzyskane wyniki wskazują, że opracowane kompozyty hybrydowe mogą być stosowane jako materiał alternatywny dla kompozytów polimerowych wzmacnianych jedynie włóknem szklanym.
Źródło:
Polimery; 2019, 64, 10; 665-675
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Determination of the optode array representation using optical properties at systole and diastole
Autorzy:
Jumadi, N A
Beng, G K
Mohd-Ali, M. A.
Zahedi, E
Powiązania:
https://bibliotekanauki.pl/articles/173805.pdf
Data publikacji:
2013
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
optical simulation
optical properties
optode array
semi-infinite tissue layer
statistical
analysis
Opis:
The necessity to develop an optode array in order to probe the fetus oxygenation noninvasively regardless of the fetus position has been highlighted in previous literature. In this paper, a series of optical simulations are carried out to determine the best representation of optode array by using optical properties at systolic and diastolic states. The selection is based on the highest flux values accumulated at respective detectors. To accomplish the objective, a homogenous three-layer semi-infinite tissue model is implemented to represent the pregnant woman model. The geometry of the model as well as Monte Carlo simulation are carried out using commercial software, whereas the optical properties related to systolic and diastolic states are defined for all wavelengths. A statistical noise analysis is also introduced in order to find a sufficient number of rays to be launched into the optical tissue system.
Źródło:
Optica Applicata; 2013, 43, 4; 747-759
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization of SnO2/TiO2 with the Addition of Polyethylene Glycol via Sol-Gel Method for Self-Cleaning Application
Autorzy:
Halin, Dewi Suriyani Che
Azliza, Azani
Razak, Kamrosni Abdul
Abdullah, Mohd Mustafa Al Bakri
Salleh, Mohd Arif Anuar Mohd
Wahab, Juyana A
Chobpattana, Varistha
Kaczmarek, Łukasz
Nabiałek, Marcin
Jeż, Bartłomiej
Powiązania:
https://bibliotekanauki.pl/articles/2203743.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
TiO2
SnO2
thin film
polyethylene glycol
self-cleaning
Opis:
TiO2 is one of the most widely used metal oxide semiconductors in the field of photocatalysis for the self-cleaning purpose to withdraw pollutants. Polyethylene glycol (PEG) is recommended as a stabilizer and booster during preparation of water-soluble TiO2. Preparation of SnO2/TiO2 thin film deposition on the surface of ceramic tile was carried out by the sol-gel spin coating method by adding different amount of PEG (0g, 0.2g, 0.4g, 0.6g, 0.8g) during the preparation of the sol precursor. The effects of PEG content and the annealing temperature on the phase composition, crystallite size and the hydrophilic properties of SnO2/TiO2 films were studied. The X-ray diffraction (XRD) spectra revealed different phases existed when the films were annealed at different annealing temperatures of 350°C, 550°C and 750°C with 0.4 g of PEG addition. The crystallite sizes of the films were measured using Scherrer equation. It shows crystallite size was dependent on crystal structure existed in the films. The films with mixed phases of brookite and rutile shows the smallest crystallite size. In order to measure the hydrophilicity properties of films, the water contact angles for each film with different content of PEG were measured. It can be observed that the water contact angle decreased with the increasing of the content of PEG. It shows the superhydrophilicity properties for the films with the 0.8 g of PEG annealed at 750°C. This demonstrates that the annealed temperature and the addition of PEG affect the phase composition and the hydrophilicity properties of the films.
Źródło:
Archives of Metallurgy and Materials; 2023, 68, 1; 243--248
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental investigation of chopped steel wool fiber at various ratio reinforced cementitious composite panels
Autorzy:
Rmdan Amer, Akrm A.
Al Bakri Abdullah, Mohd Mustafa
Ming, Liew Yun
Aziz, Ikmal Hakem A.
Mohd Tahir, Muhammad Faheem
Abd Rahim, Shayfull Zamree
Amer, Hetham A. R.
Powiązania:
https://bibliotekanauki.pl/articles/1852332.pdf
Data publikacji:
2021
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
włókno stalowe
włókno posiekane
wełna stalowa
kompozyt cementowy
płyta kompozytowa
nośność
steel fiber
chopped fiber
steel wool
cementitious composite
composite panel
load carrying capacity
Opis:
The flexural toughness of chopped steel wool fiber reinforced cementitious composite panels was investigated. Reinforced cementitious composite panels were produced by mixing of chopped steel wool fiber with a ratio range between 0.5% to 6.0% and 0.5% as a step increment of the total mixture weight, where the cement to sand ratio was 1:1.5 with water to cement ratio of 0.45. The generated reinforced cementitious panels were tested at 28 days in terms of load-carrying capacity, deflection capacities, post-yielding effects, and flexural toughness. The inclusion of chopped steel wool fiber until 4.5% resulted in gradually increasing load-carrying capacity and deflection capacities while, provides various ductility, which would simultaneously the varying of deflection capability in the post-yielding stage. Meanwhile, additional fiber beyond 4.5% resulted in decreased maximum load-carrying capacity and increase stiffness at the expense of ductility. Lastly, the inclusion of curves gradually.
Źródło:
Archives of Civil Engineering; 2021, 67, 3; 661-671
1230-2945
Pojawia się w:
Archives of Civil Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of fiber content and their hybridization on bending and torsional strength of hybrid epoxy composites reinforced with carbon and sugar palm fibers
Wpływ zawartości i hybrydyzacji włókien na wytrzymałość na zginanie oraz skręcanie hybrydowych kompozytów epoksydowych wzmocnionych włóknami węglowymi i włóknami palmy cukrowej
Autorzy:
Nik Baihaqi, N. M. Z.
Khalina, A.
Mohd Nurazzi, N.
Aisyah, H. A.
Sapuan, S. M.
Ilyas, R. A.
Powiązania:
https://bibliotekanauki.pl/articles/1789765.pdf
Data publikacji:
2021
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
sugar palm fiber
sugar palm yarn
carbon fiber
hybrid composites
epoxy resin
flexural properties
torsion properties
włókno palmy cukrowej
włókno węglowe
kompozyty hybrydowe
żywica epoksydowa
wytrzymałość na zginanie
wytrzymałość na skręcanie
Opis:
This study aims to investigate the effect of fiber hybridization of sugar palm yarn fiber with carbon fiber reinforced epoxy composites. In this work, sugar palm yarn composites were reinforced with epoxy at varying fiber loads of 5, 10, 15, and 20 wt % using the hand lay-up process. The hybrid composites were fabricated from two types of fabric: sugar palm yarn of 250 tex and carbon fiber as the reinforcements, and epoxy resin as the matrix. The ratios of 85 : 15 and 80 : 20 were selected for the ratio between the matrix and reinforcement in the hybrid composite. The ratios of 50 : 50 and 60 : 40 were selected for the ratio between sugar palm yarn and carbon fiber. The mechanical properties of the composites were characterized according to the flexural test (ASTM D790) and torsion test (ASTM D5279). It was found that the increasing flexural and torsion properties of the non-hybrid composite at fiber loading of 15 wt % were 7.40% and 75.61%, respectively, compared to other fiber loading composites. For hybrid composites, the experimental results reveal that the highest flexural and torsion properties were achieved at the ratio of 85/15 reinforcement and 60/40 for the fiber ratio of hybrid sugar palm yarn/carbon fiber-reinforced composites. The results from this study suggest that the hybrid composite has a better performance regarding both flexural and torsion properties. The different ratio between matrix and reinforcement has a significant effect on the performance of sugar palm composites. It can be concluded that this type of composite can be utilized for beam, construction applications, and automotive components that demand high flexural strength and high torsional forces.
Zbadano wpływ dodatku przędzy z włókien palmy cukrowej o grubości 250 tex na wytrzymałość kompozytów epoksydowych wzmocnionych włóknem węglowym. Sumaryczna zawartość włókien w osnowie żywicy epoksydowej była równa 5, 10, 15 i 20% mas., a stosunek udziału przędzy palmy cukrowej do włókna węglowego wynosił 50 : 50 i 60 : 40. Właściwości mechaniczne kompozytów hybrydowych o stosunku osnowy do wzmocnienia 85 : 15 i 80 : 20 scharakteryzowano na podstawie testów na zginanie i skręcanie. Stwierdzono, że wytrzymałość na zginanie i skręcanie kompozytu epoksydowego z udziałem 15% mas. przędzy palmy cukrowej była większa niż pozostałych kompozytów niehybrydowych i wynosiła, odpowiednio, 7,40% i 75,61%. W wypadku kompozytów hybrydowych stwierdzono, że najlepszą wytrzymałość na zginanie i skręcanie wykazywały kompozyty z udziałem 15% mas. wzmocnienia w stosunku 60 : 40 włókien palmy cukrowej do włókien węglowych. Różna zawartość włókien wzmacniających w osnowie epoksydowej miała istotny wpływ na właściwości wytwarzanych kompozytów. Kompozyty tego rodzaju można wykorzystać do budowy elementów konstrukcyjnych i motoryzacyjnych, o dużej wytrzymałości na zginanie i działanie sił skręcających.
Źródło:
Polimery; 2021, 66, 1; 36--43
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of fiber orientation and fiber loading on the mechanical and thermal properties of sugar palm yarn fiber reinforced unsaturated polyester resin composites
Wpływ orientacji włókien palmy cukrowej i ich zawartości na właściwości mechaniczne i termiczne kompozytów na bazie nienasyconej żywicy poliestrowej
Autorzy:
Mohd Nurazzi, N.
Khalina, A.
Chandrasekar, M.
Aisyah, H. A.
Ayu Rafiqah, S.
Ilyas, R. A.
Hanafee, Z. M.
Powiązania:
https://bibliotekanauki.pl/articles/947398.pdf
Data publikacji:
2020
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej
Tematy:
sugar palm fibers
unsaturated polyester resin
different fiber orientation
fiber loading
mechanical properties
thermal properties
włókno palmy cukrowej
nienasycona żywica poliestrowa
kompozyty
orientacja włókien
udział włókien
właściwości mechaniczne
właściwości termiczne
Opis:
Sugar palm [Arenga pinnata (Wurmb.) Merr] fiber reinforced unsaturated polyester resin composites with 0°, 45°, and 90° fiber different orientations were prepared and tested. The composites were characterized for tensile, flexural, impact and compression properties using ASTM D3039, ASTM D790, ASTM D250, and ASTM D3410 standards, respectively. For the thermal characterization, dynamic mechanical analysis (DMA) was conducted to characterize the on storage modulus (E’), loss modulus (E’’) and damping behavior (tan δ) of the composites. The highest mechanical performance of composites was achieved at 0° of fiber orientation composites followed by 45° and 90° fiber orientations. The fiber loading was insignificant for the 90° fiber orientation as the properties were inconsistent. The theoretical value of modulus from the tensile test was calculated using rules of mixture (ROM) and compared with the experimental values for all composites specimens. This research showed that the optimum properties occurred at 30 wt % fiber loading as reflected by the superior tensile and flexural strengths. The optimum properties of compression, impact, storage modulus and better damping properties were achieved at 40 wt % fiber loading.
Przygotowano kompozyty na bazie nienasyconej żywicy poliestrowej wzmocnionej różną ilością włókien palmy cukrowej [Arenga pinnata (Wurmb.) Merr] o rozmaite jorientacji: 0°, 45° i 90°. Z zastosowaniem norm, odpowiednio, ASTM D3039, ASTM D790, ASTM D250 i ASTM D3410 oznaczono wytrzymałość na rozciąganie i zginanie oraz odporność na uderzenie i ściskanie otrzymanych kompozytów. Właściwości termiczne scharakteryzowano metodą dynamicznej analizy mechanicznej (DMA); wyznaczono moduł zachowawczy (E’), moduł stratności (E”) i tangens kąta stratności (tan δ) kompozytów. Najlepsze właściwości mechaniczne kompozytów uzyskano w wypadku zastosowania włókien o orientacji 0° względem przyłożonej siły, a najgorsze w wypadku ułożenia włókien pod kątem 90°. W odniesieniu do kompozytów wzmocnionych włóknami o orientacji 90° udział włókien miał nieistotny wpływ na oznaczane właściwości, ponieważ wyniki były niespójne. Wartość teoretyczną modułu rozciągania wszystkich próbek kompozytów obliczono z wykorzystaniem reguły mieszania (ROM) i porównano z wartościami uzyskanymi doświadczalnie. Stwierdzono, że doskonałą wytrzymałość na rozciąganie i zginanie wykazywał kompozyt z 30 % mas. udziałem włókien, podczas gdy optymalne: wytrzymałość na ściskanie, udarność, moduł zachowawczy i właściwości tłumiące uzyskano w wypadku udziału 40 % mas. włókien.
Źródło:
Polimery; 2020, 65, 2; 115-124
0032-2725
Pojawia się w:
Polimery
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Technology acceptance in learning history subject using augmented reality towards smart mobile learning environment : case in Malaysia
Autorzy:
Suhaimi, H.
Aziz, N. N.
Mior Ibrahim, E. N.
Wan Mohd Isa, W. A. R.
Powiązania:
https://bibliotekanauki.pl/articles/27314247.pdf
Data publikacji:
2022
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
smart city education
mobile learning
augmented reality
history
technology acceptance model
Opis:
In alignment with smart city initiatives, Malaysia is shifting its educational landscape to a smart learning environment. The Ministry of Education (MoE) has made History a mandatory subject for passing the Malaysian Certificate of Education to grow awareness and instil patriotism among Malaysian students. However, History has been known as one of the difficult subjects to study for many students. On the other hand, the Malaysian Government Education Blueprint 2013-2025 seeks to “leverage ICT scale up quality learning” across the country. Therefore, this study aims to identify the factors that influence the intention to use Augmented Reality (AR) for mobile learning in learning History subject among secondary school students in Malaysia. Quantitative approach has been chosen as the research method for this study. A direct survey was conducted on 400 secondary school students in one of the smart cities in Malaysia as the target respondents. The collected data are analysed through descriptive statistics and Multiple Linear Regression analysis by using Statistical Package for the Social Sciences. Based on the results, the identified factors that influence the intention to use AR for mobile learning in learning History subject are Gender, Perceived Usefulness, Perceived Enjoyment, and Attitude Towards Use. The identified factors can be a good reference for schools and teachers to strategize their teaching and learning methods in pertaining to History subject among secondary school students in Malaysia. Future studies may include the study of various types of schools in Malaysia and explore more moderating effects of demographic factors.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2022, 16, 2; 20--29
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Efficient online handwritten Chinese character recognition system using a two-dimensional functional relationship model
Autorzy:
Chang, Y. F.
Lee, J. C.
Mohd Rijal, O.
Syed Abu Bakar, S. A. R.
Powiązania:
https://bibliotekanauki.pl/articles/908140.pdf
Data publikacji:
2010
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
2D
współczynnik determinacji
rozpoznawanie
pismo odręczne
pismo chińskie
falka Haara
model relacyjny
2D functional classifier
coefficient of determination
handwritten Chinese character recognition
Haar wavelet
multidimensional functional relationship model
Opis:
This paper presents novel feature extraction and classification methods for online handwritten Chinese character recognition (HCCR). The X-graph and Y-graph transformation is proposed for deriving a feature, which shows useful properties such as invariance to different writing styles. Central to the proposed method is the idea of capturing the geometrical and topological information from the trajectory of the handwritten character using the X-graph and the Y-graph. For feature size reduction, the Haar wavelet transformation was applied on the graphs. For classification, the coefficient of determination [...] from the two-dimensional unreplicated linear functional relationship model is proposed as a similarity measure. The proposed methods show strong discrimination power when handling problems related to size, position and slant variation, stroke shape deformation, close resemblance of characters, and non-normalization. The proposed recognition system is applied to a database with 3000 frequently used Chinese characters, yielding a high recognition rate of 97.4% with reduced processing time of 75.31%, 73.05%, 58.27% and 40.69% when compared with recognition systems using the city block distance with deviation (CBDD), the minimum distance (MD), the compound Mahalanobis function (CMF) and the modified quadratic discriminant function (MQDF), respectively. High precision rates were also achieved.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2010, 20, 4; 727-738
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
SYNTHESIS, AND EVALUATION OF COUMARIN HYBRIDS AS ANTIMYCOBACTERIAL AGENTS
Autorzy:
Hassan, Mohd Z.
ALSAYARI, ABDULRHMAN
OSMAN, HASNAH
ALI, MOHAMED A.
MUHSINAH, ABDULLATIF B.
AHSAN, MOHAMED J.
Powiązania:
https://bibliotekanauki.pl/articles/895509.pdf
Data publikacji:
2019-12-29
Wydawca:
Polskie Towarzystwo Farmaceutyczne
Tematy:
cytotoxicity
Coumarin
TB
Thiazolopyrimidine
HTS
antimycobacterial
Opis:
A series of twelve hybrid coumarin analogues were synthesized and screened through HTS for their antimycobacterial activity against Mtb H37Rv. The hybrid molecules were efficiently synthesized by the reactions of 3-(bromoacetyl)coumarin with Biginelli products 2-mercapto-6-oxo-4-aryl-1,6-dihydropyrimidine-5-carbonitriles. Of the resulting twelve hybrids, the two compounds 7-(2,4-dichlorophenyl)-5-oxo-3-(2-oxo-2H-chromen-3-yl)-5H-thiazolo[3,2-a] pyrimidine-6-carbonitrile (3d) and 7-(4-nitrophenyl)-5-oxo-3-(2-oxo-2H-chromen-3-yl)-5H-thiazolo[3,2-a]pyrimidine-6-carbonitrile (3f) showed excellent antimycobacterial activity against Mtb (EC50 3.19 & 7.91 µM, respectively) and low cytotoxicity against the VERO cell line (IC50 > 62.5 µg/mL).
Źródło:
Acta Poloniae Pharmaceutica - Drug Research; 2019, 76, 6; 1029-1036
0001-6837
2353-5288
Pojawia się w:
Acta Poloniae Pharmaceutica - Drug Research
Dostawca treści:
Biblioteka Nauki
Artykuł

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