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Wyszukujesz frazę "Ali, F." wg kryterium: Autor


Tytuł:
A Short Range Synthetic Aperture Imaging Radar with Rotating Antenna
Autorzy:
Ali, F.
Urban, A.
Vossiek, M.
Powiązania:
https://bibliotekanauki.pl/articles/226520.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
radar
synthetic aperture
scanning
imaging
Opis:
The design of a short range synthetic aperture imaging radar is introduced in this paper. A radar hologram is acquired using a small omnidirectional antenna that is mounted on a rotating platform. After each turn of the platform a high resolution 360° 2D image is reconstructed; a rotating window function optimizes the reconstructed image function to get the best image focus for detecting both weak and strong scatterers. The rotating window function depends on the target direction and is executed for each image point and each target direction. The size of the synthetic aperture – and thus the lateral resolution of the imaging system – is determined by the diameter of the circular antenna trajectory. In contrast to common radar scanner concepts that utilize highly directional and thus bulky antennas, the proposed scanner concept has the advantage of using a small, lightweight omni-directional antenna. The developed radar system is much more compact and the scanning mechanics are significantly simplified. Furthermore, an omni-directional antenna offers very straightforward options for powering the radar on the rotation platform. Measurement results obtained with a 24 GHz FMCW short range radar sensor illustrate the performance of the proposed SAR imaging method.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 1; 97-102
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Phytoextraction of Cr by maize (Zea mays L.) : the role of plant growth promoting endophyte and citric acid under polluted soil
Autorzy:
Ali, J.
Mahmood, T.
Hayat, K.
Afridi, M. S.
Ali, F.
Chaudhary, H. J.
Powiązania:
https://bibliotekanauki.pl/articles/204568.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
maize
phytoextraction
chromium
citric acid
Burkholderia vietnamiensis
Opis:
High chromium (Cr) toxicity has turned into a serious environmental concern. Cr contaminated agronomic soils negatively affect the growth and yield of crops. Current research was conducted to enhance the phytoextraction potential of maize by using Burkholderia vietnamiensis and citric acid (CA). Plants were subjected to three concentrations of Cr (0.86, 350, and 500 ppm). A pot experiment was conducted under greenhouse conditions with completely randomized design (CRD). After 72 days of experiment, plants were harvested to analyze the morphological and biochemical attributes of soil, bacteria and plant. Results revealed that plant fresh, dry biomass, root, shoot length and chlorophyll contents significantly increased by 56%, 50%, 58%, 78% and 60%, respectively, at 500 ppm Cr concentration in combine treatment of B. vietnamiensis and CA. Maize plants treated with both B. vietnamiensis and CA significantly increased the bioaccumulation (BA) of Cr up to 50% and translocation factor (TF) by 31%. Furthermore, superoxide dismutase (SOD), proline and peroxidase dismutase (POD) activities in leaves were markedly increased by 30%, 42% and 15%, respectively, when treated with CA. Current study reveals that exogenous co-application of B. vietnamiensis + CA enhance plant growth by alleviating heavy metal stress and accelerate the phytoextraction of Cr. Taking into account the heavy metal tolerance and accumulation capacity, Zea mays is suitable for phytoremediation of contaminated soils in combination with B. vietnamiensis and CA.
Źródło:
Archives of Environmental Protection; 2018, 44, 2; 73-82
2083-4772
2083-4810
Pojawia się w:
Archives of Environmental Protection
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Supplemental effects of silicon nutrition on growth, quality and some physiological characters of potted chrysanthemum grown in greenhouse
Suplementacyjny wpływ żywienia krzemem na wzrost, jakość i niektóre cechy fizjologiczne doniczkowych chryzantem uprawianych w szklarni
Autorzy:
Ali, E.F.
Hassan, F.A.S.
Powiązania:
https://bibliotekanauki.pl/articles/11543323.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Tematy:
supplementation effect
silicon
membrane stability
plant growth
plant quality
plant physiology
pot chrysanthemum
chrysanthemum
greenhouse
Opis:
Potted chrysanthemum is one of the most important floriculture plants which commercially produced in greenhouses where silicon (Si) is available in limited concentration because of using several substrates as growing media. Therefore, this study was conducted to investigate the supplemental effects of Si nutrition on growth, flowering, flower longevity as well as shelf life and nutrients content of potted chrysanthemum in relation to Si application. Moreover, the effects of Si treatment on some physiological parameters i.e. chlorophyll content, stomatal resistance, membrane stability index (MSI) and total carbohydrates were also investigated. Si application as K₂SiO₃ was added whether as foliar application at 25, 75 and 125 mg L⁻¹ Si or soil drenches at 50, 100 and 150 mg L⁻¹ Si. Except plant height and leaf area, the other vegetative growth and flowering characters were improved as a result of both Si supplementation methods compared with untreated control. Flowering was earlier and shelf life was longer in Si-supplemented than nonsupplemented plants. Generally, Si application increased the macro and micronutrients concentrations (except Ca) estimated in this study. Chlorophyll content, stomatal resistance, MSI and total carbohydrates were increased among Si treated plants. Improving the floricultural traits, extending longevity and shelf life of greenhouse grown chrysanthemum may give an impact of its greenhouse commercial production if appropriate level was used.
Chryzantema doniczkowa to jedna z najważniejszych roślin, które są komercyjnie produkowane w szklarniach, gdzie krzem (Si) jest dostępny w ograniczonym stężeniu, gdyż do uprawy używane są różne podłoża. Niniejsze badanie przeprowadzono w celu zbadania skutków suplementacyjnych żywienia Si na wzrost, kwitnienie, długość życia kwiatów, a także żywotność i zawartość składników odżywczych chryzantemy doniczkowej w stosunku do aplikacji Si. Ponadto zbadano skutki zabiegów z użyciem Si na niektóre parametry fizjologiczne, to znaczy zawartość chlorofilu, działanie aparatów szparkowych, wskaźnik stabilności błon (MSI) oraz całkowitą zawartość węglowodanów. Zastosowanie Si w postaci K₂SiO₃ dodano jako aplikację dolistną w ilości 25, 75 i 125 mg L⁻¹ Si lub do podłoża przy 50, 100 i 150 mg L⁻¹ Si. Z wyjątkiem wysokości roślin i obszaru liścia, w porównaniu z kontrolą bez żadnych zabiegów, wszystkie cechy wzrostu i kwitnienia polepszyły się w wyniku zastosowania obu metod suplementacji. Kwitnienie było wcześniejsze, a żywotność dłuższa u roślin z suplementacją Si niż u roślinach bez suplementacji. Generalnie zastosowanie Si zwiększało stężenie makro- i mikroskładników (z wyjątkiem Ca) ocenianych w niniejszym badaniu. Zawartość chlorofilu, działanie aparatów szparkowych, MSI oraz całkowita zawartość węglowodanów zwiększały się wśród roślin z zastosowaniem Si. Polepszenie cech kwiatowych, zwiększenie długości życia i żywotności chryzantem hodowanych w szklarni może mieć wpływ na komercyjną produkcję szklarniową, jeśli zastosuje się jego odpowiedni poziom.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2016, 15, 4; 85-98
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Production of bioactive metabolites from different marine endophytic Streptomyces species and testing them against methicillin-resistant Staphylococcus aureus (MRSA) and cancer cell lines
Autorzy:
El-Gendy, M.M.A.A.
Mohamed, Z.K.
Hekal, N.Z.
Ali, F.M.
Yousef, A.E.M.
Powiązania:
https://bibliotekanauki.pl/articles/81078.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Staphylococcus aureus
infection
methicillin-resistant Staphylococcus aureus
endophyte
Streptomyces
bioactive metabolite
Actinomycetes
marine invertebrate
anticancer activity
cancer cell line
lung cancer
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2018, 99, 1
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inverse Hall-Petch Like Mechanical Behaviour in Nanophase Al-Cu-Fe Quasicrystals: A New Phenomenon
Autorzy:
Mukhopadhyay, N.
Ali, F.
Scudino, S.
Samadi Khoshkhoo, M.
Stoica, M.
Srivastava, V.
Uhlenwinkel, V.
Vaughan, G.
Suryanarayana, C.
Eckert, J.
Powiązania:
https://bibliotekanauki.pl/articles/1373423.pdf
Data publikacji:
2014-08
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
61.44.Br
Opis:
The structural and mechanical stability of quasicrystals are important issues due to their potential for possible applications at high temperatures and stresses. The aim of the present work is, therefore, to review the earlier works on conventional crystalline and quasicrystalline materials and also to report the results and the analysis on the Hall-Petch and inverse Hall-Petch like behavior of nanoquasicrystalline $Al_{62.5}Cu_{25}Fe_{12.5}$ alloys. It was observed that, at large grain sizes, the hardness increases with decreasing grain size, exhibiting the conventional Hall-Petch relationship, whereas for smaller grains, inverse Hall-Petch behavior was identified. The inverse Hall-Petch behavior in the nanoquasicrystalline phase could be attributed to thermally activated shearing of the grain boundaries, leading to grain boundary sliding in nanostructures of quasicrystalline grains. These results were analyzed based on the dislocation pile-up model as well as the grain boundary shearing models applicable to nanomaterials.
Źródło:
Acta Physica Polonica A; 2014, 126, 2; 543-548
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The Correlation between Solar Flare Phenomena in an X-ray Region and Radio Flux Measurement from January to September 2010
Autorzy:
Hamidi, Z. S.
Shariff, N. N. M.
Ali, M. F.
Monstein, C.
Zulkifli, W. N. A. W.
Ibrahim, M. B.
Arifin, N. S.
Amran, N. A.
Powiązania:
https://bibliotekanauki.pl/articles/411743.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
sun
chromospheres
flares
radio flux
solar activity
Opis:
A short term variation of solar flare in nine months (January 2010 to September 2010) is presented. This paper review and analyze the correlation between radio flux strength measurement and solar flare in the X-ray region. The radio flux measurement data were taken from the National Research Council; Ottawa while hard X-ray emission observed by Royal Observatory of Belgium. The overall range of solar radio flux recorded in this study ranging from 68 x 10-22 Wm-2Hz-1 to 96 x 10-22 Wm-2Hz-1. As there was no class of an X of solar flare reported at all in this study, we can confirm that there are no major effects that happened on Earth and outer space such as Coronal Mass Ejections (CMEs) and solar storms. We concluded that the Sun shows a very minimum activity towards 24th solar cycle.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 9; 84-92
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Involvement of ethylene synthetic inhibitors in regulating the senescence of cut carnations through membrane integrity maintenance
Autorzy:
Hassan, F.
Ali, E.
Mazrou, R.
Powiązania:
https://bibliotekanauki.pl/articles/1079037.pdf
Data publikacji:
2020
Wydawca:
Instytut Ogrodnictwa
Tematy:
cut flower
flower senescence
1-methylcyclopropene
silver nanoparticle
nitric oxide
sodium nitroprusside
vase life
membrane stability
cut carnation
Opis:
Postharvest senescence is a critical problem of carnation cut flowers, limiting their transportation and subsequent marketing chain. This study was designed to assess whether the application of 1-methylcyclopropene (1 MCP), silver nanoparticles (AgNPs), and nitric oxide (NO) released from donor sodium nitroprusside (SNP) could prolong the vase life of cut carnations through an influence on the physiological and biochemical mechanisms involved in aging process. 1-MCP was used in the concentrations of 0, 100, 200, and 300 mg·m-3; AgNPs in the concentrations of 0, 50, 100, and 150 mg·dm-3; and SNP in the concentrations of 0, 0.1, 0.2, 0.3, and 0.4 mM. All treatments significantly extended the cut flower life compared with untreated flowers, more so with 300 mg·m-3 of 1-MCP, 100 mg·dm-3 of AgNPs, or 0.3 mM of SNP. All these chemical compounds were able to considerably improve the relative water content (RWC), reduce the malondialdehyde (MDA) content and increase the membrane stability index (MSI) in petals and, therefore, maintain the membrane integrity. In addition, they decreased the activities of acetyl-CoA synthetase (ACS) and nitric oxide synthase (NOS) and, hence, depressed the production of ethylene in carnation cut flowers through downregulating the ethylene production, what prolonged the vase life. Altogether, the application of exogenous 1-MCP, AgNPs, or SNP may provide a promising avenue to improve the postharvest performance of carnation cut flowers.
Źródło:
Journal of Horticultural Research; 2020, 28, 1; 39-48
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimization Of Protocol For Biodiesel Production Of Linseed (Linum Usitatissimum L.) Oil
Autorzy:
Ullah, F.
Bano, A.
Ali, S.
Powiązania:
https://bibliotekanauki.pl/articles/779238.pdf
Data publikacji:
2013
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
linseed
biodiesel
protocol
optimization
Opis:
Attempts were made to optimize variables affecting the yield of linseed oil biodiesel in a base catalyzed transesterification reaction. The variables studied were reaction temperature (40-70oC), catalyst (NaOH) concentration (0.1-1.5%) and reaction time (30-180 min). The conversion of linseed oil into methyl esters was confirmed through analytical methods like 1H NMR, gas chromatography (GC) and refractometer. The maximum biodiesel yield (97š1.045% w/w) was obtained at 0.5% catalyst concentration, 65oC temperature, 180 min reaction time and 6:1 molar ratio of methanol to oil. 1H NMR confirmed the practically obtained % conversion of triglycerides into methyl esters which was further evidenced by refractometer analyses. The refractive index of biodiesel samples was lower than pure linseed oil. GC analysis confirmed the presence of linolenic acid (C18:3) as the dominant fatty acid (68 wt. %) followed by oleic acid (C18:1), linoleic acid (C18:2) and stearic acid (C18:0) respectively. The physical properties of linseed oil biodiesel like specific gravity (0.90 g/cm3) and flash point (177oC) were higher than American Society for Testing and Materials standards (ASTM 6751) for biodiesel. However, kinematic viscosity (3.752 mm2/s) was in the range of ASTM standards.
Źródło:
Polish Journal of Chemical Technology; 2013, 15, 1; 74-77
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Approach to Secure Communication in IoT (Internet of Things)
Autorzy:
Ali Ahammed, G. F.
Banu, Reshma
Fathima, Nasreen
Powiązania:
https://bibliotekanauki.pl/articles/1193541.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
6LoWPAN
Bootstrapping
IETF
IoT
threats
Opis:
The term Internet of Things (IoT) refers to the use of standard internet protocols for interaction between human to things or things to things in an embedded network. Although the security needs are well-recognized, it is still not fully clear how existing IP-based security protocols can be applied to this new setting. In this paper we discuss the various security challenges in an IoT system. The paper also provides a standard IP-based security protocols and its implementation model which can be used as a security system for IoT.
Źródło:
World Scientific News; 2016, 41; 27-33
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Prediction cost maintenance model of office building based on condition-based maintenance
Predykcyjno-kosztowy model konserwacji budynku biurowego oparty o utrzymanie zależne od bieżącego stanu technicznego (CBM)
Autorzy:
Au-Yong, C. P.
Ali, A. S.
Ahmad, F.
Powiązania:
https://bibliotekanauki.pl/articles/301654.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Polskie Naukowo-Techniczne Towarzystwo Eksploatacyjne PAN
Tematy:
charakterystyki
utrzymanie zależne od bieżącego stanu technicznego (CBM)
wydajność kosztu
budynek biurowy
Malezja
characteristics
condition-based maintenance
cost performance
office building
Malaysia
Opis:
Koszty konserwacji budynków nieustannie rosną ze względu na nieodpowiednią konserwację. Z tej racji, niezbędne jest wypracowanie rozwiązań obniżających koszty konserwacji. Różne badania wykazały, iż charakterystyki utrzymania urządzeń zależnie od ich bieżącego stanu technicznego (condition-based maintenance, CBM) są bezpośrednio powiązane z wydajnością kosztu. Niniejszy artykuł stara się więc ustalić związek pomiędzy charakterystykami utrzymania budynków zależnie od ich bieżącego stanu technicznego a wydajnością kosztu. Następnie opracowano model regresji dla planowania konserwacji jak i predykcji. W badaniach użyto metody mieszanej łączącej badania kwestionariuszowe, wywiad oraz studium przypadku. Rezultaty podkreśliły, iż wiarygodność danych z konserwacji i informacji to najbardziej istotne charakterystyki CBM. W konsekwencji, wnioski z badań sugerują, iż planowanie i wdrożenie strategii utrzymania w zależności od bieżącego stanu technicznego powinno brać pod uwagę jej istotne charakterystyki i odwoływać się do wynikającego z niej modelu predykcji. Ponadto, praca zawiera zalecenia jakimi środkami można w praktyce poprawić istotne charakterystyki i wydajność kosztu.
Building maintenance costs are continuously increasing as a result of poor maintenance. Consequently, there is an urgent need to develop solutions to reduce the maintenance costs. Various studies demonstrated that the characteristics of condition-based maintenance are directly related to the cost performance. Thus, this paper seeks to establish the relationships between the characteristics of condition-based maintenance and the cost performance. The researcher then developed a regression model for maintenance planning and prediction. The study adopted a mix method approach that includes questionnaire survey, interview, and case study. The findings highlighted the reliability of maintenance data and information as the most significant characteristic of conditionbased maintenance. Consequently, the study concluded that the planning and the application of the condition-based maintenance strategy should consider its significant characteristics and make reference to the resulting prediction model. Furthermore, the study recommended measures to improve the significant characteristics and the cost performance in practice.
Źródło:
Eksploatacja i Niezawodność; 2014, 16, 2; 319-324
1507-2711
Pojawia się w:
Eksploatacja i Niezawodność
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Substrate Temperature Effects on the Nanostructural and Optical Parameters of CdO Thin Films
Autorzy:
Habubi, Nadir F.
Jadduaa, Muneer H.
Harbi, Zainab Ali
Powiązania:
https://bibliotekanauki.pl/articles/1193957.pdf
Data publikacji:
2015
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
CdO thin films
chemical spray pryrolysis
optical parameters
structural parameters
Opis:
CdO thin films were prepared by the chemical spray pyrolysis technique under different glass substrate temperature (300, 350, 400, 450 and 500 °C). XRD anaylsis confirms the cubic polycrystalline nature of the deposited thin films with a preferred orientation along (111) plane. The average crystallite size suggests the formation of nanostructure of the deposited films. The average particle size obtained by AFM assure the existence of nanostructure. The values of the energy gap obtained from the derivative of absorbance with respect to the incident photon energy were found to increase from 2.610 nm to 2.666 nm as the substrate temperature increase.the values of refractive index and extinction coefficient were decreased by the increasing substrate temperature.
Źródło:
World Scientific News; 2015, 18; 19-34
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Three-Axis Attitude Estimation Of Satellite Through Only Two-Axis Magnetometer Observations Using LKF Algorithm
Autorzy:
Mehrjardi, M. F.
Sanusi, H.
Ali, M. A. M.
Powiązania:
https://bibliotekanauki.pl/articles/221622.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
satellite three-axis attitude estimation
two-axis magnetometer
observations
LKF
PD controller
Opis:
Estimation of satellite three-axis attitude using only one sensor data presents an interesting estimation problem. A flexible and mathematically effective filter for solving the satellite three-axis attitude estimation problem using two-axis magnetometer would be a challenging option for space missions which are suffering from other attitude sensors failure. Mostly, magnetometers are employed with other attitude sensors to resolve attitude estimation. However, by designing a computationally efficient discrete Kalman filter, full attitude estimation can profit by only two-axis magnetometer observations. The method suggested solves the problem of satellite attitude estimation using linear Kalman filter (LKF). Firstly, all models are generated and then the designed scenario is developed and evaluated with simulation results. The filter can achieve 10e-3 degree attitude accuracy or better on all three axes.
Źródło:
Metrology and Measurement Systems; 2015, 22, 4; 577-590
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Green fibers-reinforced cement mortar with the inclusion of nano-CaCo3 and metakaolin
Autorzy:
Hamad, Ali Jihad
Sldozian, Rami Joseph
Kadhim, Ruqaya F.
Powiązania:
https://bibliotekanauki.pl/articles/38890067.pdf
Data publikacji:
2024
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
fibers reinforced cement mortar
date palm fibers
DPF
nano calcium carbonate
nano-CaCO3
metakaolin
MK
pozzolanic materials
Opis:
Over the previous few decades, there has been a noticeable increase in interest in the use of vegetable fibers and supplemental cementitious elements in mortar and concrete. The date palm frond was utilized in this study to create date palm fibers (DPF), which were then added to the cement mortar at percentages of 1%, 2%, 3%, 4%, and 5% by cement weight. There were two types of DPFs used: one type was untreated, and the other had a mechanical treatment that created holes before applying a layer of polychloroprene (neoprene) on the surface. Metakaolin (MK) and nano calcium carbonate (nano-CaCo3) were added to the cement mortar by the weight of cement. MK was replaced by 10% of the weight of cement. Besides, the nano-CaCo3 was replaced by 1%, 2%, 3%, and 4% of the weight of cement. Mechanical tests for flowability, compressive strength, and flexural strength were conducted. In addition, one MCDM methodology called VIKOR is utilized to choose the best combination out of several combinations and criteria. The results indicate that a higher DPF concentration enhances both compressive and flexural strength. The mixtures with the DPF coating and mechanical treatment give the strongest and most significant results. In addition, the flowability of cement mortar decreases when the DPF concentration increases. In addition to the high content of nano-CaCo3 in cement mortar, given the grater reading of strength, the presence of nano- CaCo3 in cement mortar reduces the disparity in result values that have a higher DPF content. The mixtures containing 4% and 5% DPF and 3% and 4% nano-CaCo3 are the optimal ones, according to the VIKOR technique.
Źródło:
Engineering Transactions; 2024, 72, 1; 39-60
0867-888X
Pojawia się w:
Engineering Transactions
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mechanical properties and microstructure of alkali activated mortar containing unexpanded clay
Autorzy:
Nasser, I.F.
Ali, M.A.
Kadhim, M.J.
Powiązania:
https://bibliotekanauki.pl/articles/2201132.pdf
Data publikacji:
2022
Wydawca:
Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach
Tematy:
alkali-activated mortar
pozzolan
unexpanded clay
flexural toughness
scanning electron microscope
thermal insulation
pucolana
glina nie spulchniona
wytrzymałość na zginanie
skaningowy mikroskop elektronowy
izolacja termiczna
Opis:
Purpose: In building constructions, due to the decrease of local raw materials and for sustainability purpose, beside the need of light pieces to be used in roofing and false ceiling; an alkali-activated mortar is the new development where pozzolanic material is used instead of cement and activated by an alkaline solution. Therefore, in this research, alkali-activated mortar containing unexpanded clay as a fine aggregate with a dry density of 1652 kg/m3, compressive strength of 3.2 MPa, and thermal conductivity of 0.4 (W/m.K) was produced ,also boards were performed in a dimension of 305×152×12 mm as to use them in false ceiling, and reinforced with 0.25 and 0.5% steel fibre to improve their toughness by 370.8% and 1146.1% compared with reference boards, which made them good choice to used them in roofing and secondary ceiling. Design/methodology/approach: For preparation of alkali-activated mortar, low calcium fly ash (FA) was used as a source binder material. In addition, super-plasticizer and unexpanded clay as a fine aggregate (produce from the crushed artificial aggregate) in the ratio of 1:2.75 fly ash/fine aggregate. The paste was prepared by mixing fly ash with an alkali silicate solution, in a solid-to-liquid ratio of 0.4. Alkali silicate activator was prepared by mixing the NaOH and Na2SiO3 solutions at the mass ratios of 2.5. The concentrations of the NaOH was the same molarity of (14M).To improve the mechanical properties of the reference mortar mixture ,steel fibre with 0.25 and 0.5% content were added to the mix .The specimens were tested for water absorption, dry density, compressive strength, flexural strengths, flexural toughness, and thermal conductivity, in addition to the Scanning Electron Microscope test (SEM) for all mortar mixes. Alkali-activated mortar boards with (305×152×12 mm) were prepared and tested for flexural strength and toughness. Findings: The results indicated that the modulus of rupture for mortar boards reinforced with 0.25 and 0.5% steel fibre exhibits an increase of (3.68-12.10)%. In comparison, the toughness is increased by about 370.8% and 1146.1%, respectively, as compared with the reference mortar (without fibre) which made them resistance to accident, in addition to use them in roofing due to their thermal insulation. Research limitations/implications: Further research is needed to make a similar board using another sustainable material. We can examine the thermal insulation that we can get from these board, especially in the building in Iraq which the weather faces high temperatures. Practical implications: There is a by-product that we could get from the electricity station in Iraq. We must study how we get rid of it. Originality/value: This paper investigate how to produce a new light board using artificial aggregate made from unexpanded clay, which has many benefits in building insulation roofing.
Źródło:
Archives of Materials Science and Engineering; 2022, 113, 2; 56--68
1897-2764
Pojawia się w:
Archives of Materials Science and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł

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