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


Tytuł:
Beam Pattern Optimization Via Unequal Ascending Clusters
Autorzy:
Abdulqader, Ahmed Jameel
Mohammed, Jafar Ramadhan
Ali, Yessar E. Mohammad
Powiązania:
https://bibliotekanauki.pl/articles/2200966.pdf
Data publikacji:
2023
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
beam pattern
clustered array
genetic algorithm
sidelobes
Opis:
In this paper, two different architectures based on completely and sectionally clustered arrays are proposed to improve the array patterns. In the wholly clustered arrays, all elements of the ordinary array are divided into multiple unequal ascending clusters. In the sectionally clustered arrays, two types of architectures are proposed by dividing a part of the array into clusters based on the position of specific elements. In the first architecture of sectionally clustered arrays, only those elements that are located on the sides of the array are grouped into unequal ascending clusters, and other elements located in the center are left as individual and unoptimized items (i.e. uniform excitation). In the second architecture, only some of the elements close the center are grouped into unequal ascending clusters, and the side elements were left individually and without optimization. The research proves that the sectionally clustered architecture has many advantages compared to the completely clustered structure, in terms of the complexity of the solution. Simulation results show that PSLL in the side clustered array can be reduced to more than −28 dB for an array of 40 elements. The PSLL was −17 dB in the case of a centrally clustered array, whereas the complexity percentage in the wholly clustered array method was 12 .5 %, while the same parameter for the partially clustered array method equaled 10%.
Źródło:
Journal of Telecommunications and Information Technology; 2023, 1; 1--7
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Bee Pollen as a Functional Product – Chemical Constituents and Nutritional Properties
Autorzy:
Alshallash, Khalid S.
Abolaban, Gomaa
Elhamamsy, Sam M.
Zaghlool, Ayman
Nasr, Ali
Nagib, Ashraf
Abd El-Hakim, Ahmed F.
Zahra, Abdullah A.
Hamdy, Ashraf E.
Taha, Ibrahim M.
Powiązania:
https://bibliotekanauki.pl/articles/2202357.pdf
Data publikacji:
2023
Wydawca:
Polskie Towarzystwo Inżynierii Ekologicznej
Tematy:
eucalyptus
clover
maize
phenolic content
amino acid
pollen
Opis:
Nutritional supplements play a role in promoting human protein synthesis, fitness recovery, and mental health protection. Pollen is considered a natural food with excellent nutritional value. The use of bee-gathered pollen as a nutritional supplement is now widespread around the world, and it is appreciated for its healing qualities. However, depending on the floral species and the region of origin, pollen has a wide range of nutritional value. It was found that clover pollen had the highest protein content (31.4 g/100 g DM), while the lowest content was observed in maize pollen (21.3%). Eucalyptus pollen had the highest lipid amount (9.49 g/100 g DM), while clover pollen had the lowest content (7.46 g/100 g). Phytochemical analysis showed that eucalyptus pollen occupied the highest total antioxidant activity (67.02%), followed by clover (58.25%) then maize (52.18%), whereas clover pollen had the highest phenolic content (1165 mg GAE/100 gm), compared with the other pollen varieties (949.4 to 1073 mg-GAE/100 gm). The contents of branched-chain amino acids were 29, 33.3, and 38.4 mg/g for maize, eucalyptus, and clover respectively, representing 17.87, 18.44, and 16.53% of total amino acids. The contents of total essential amino acids (EAAs) were 61.8, 73.0, and 83.5 mg/g for maize, eucalyptus, and clover pollen, respectively. Only eucalyptus pollen ultimately met the minimum requirements of EAAs for adults. In contrast, the other two types of pollen contained at least 3–4 limiting amounts of the essential amino acids leucine, lysine, phenylalanine, and valine. In conclusion, pollen is a good, affordable source of nutrients that can be utilized as beneficial dietary supplements for human health.
Źródło:
Journal of Ecological Engineering; 2023, 24, 2; 173--183
2299-8993
Pojawia się w:
Journal of Ecological Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On knowledge discovery and representations of molecular structures using topological indices
Autorzy:
Alsaadi, Fawaz E.
Bokhary, Syed Ahtsham Ul Haq
Shah, Aqsa
Ali, Usman
Cao, Jinde
Alassafi, Madini Obad
Rehman, Masood Ur
Rahman, Jamshaid Ul
Powiązania:
https://bibliotekanauki.pl/articles/2031152.pdf
Data publikacji:
2021
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
graph network
sheet
topological index
cheminformatics
knowledge discovery
Opis:
The main purpose of a topological index is to encode a chemical structure by a number. A topological index is a graph invariant, which decribes the topology of the graph and remains constant under a graph automorphism. Topological indices play a wide role in the study of QSAR (quantitative structure-activity relationship) and QSPR (quantitative structure-property relationship). Topological indices are implemented to judge the bioactivity of chemical compounds. In this article, we compute the ABC (atom-bond connectivity); ABC4 (fourth version of ABC), GA(geometric arithmetic) and GA5(fifth version of GA) indices of some networks sheet. These networks include: octonano window sheet; equilateral triangular tetra sheet; rectangular sheet; and rectangular tetra sheet networks.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2021, 11, 1; 21-32
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Assessment of Lower Zab river water quality using both Canadian Water Quality Index Method and NSF Water Quality Index Method
Autorzy:
Ahmed, Sarah M.
Taha, Omer M.E.
Najemalden, Mohamed A.
Ahmed, Rehab T.
Abedulwahab, Ali A.
Powiązania:
https://bibliotekanauki.pl/articles/118599.pdf
Data publikacji:
2020
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
NSF Water Quality Index
Canadian Water Quality Index
Lower Zab river
physicochemical parameters
dissolved oxygen
biochemical oxygen demand
Opis:
Rivers are considered the most important sources of surface water on Earth. They are play a significant role in all human activities and the quality of river water is needed. Therefore, the importance of the water quality index is arising through providing data base about quality of the water source, and explain the change in the water quality over a period of time continually. This study involved determination of physicochemical and biological parameters of Lower Zab river in Kirkuk city at two different points. The objectives of the study are to assess the present water quality, through analysis of some selected water quality parameters like pH, TDS, BOD, dissolved oxygen, turbidity, EC, alkalinity, and salinity etc. and to compare the results with the Canadian Council of Ministers of the Environment and National Sanitation Foundation Water Quality Indices. Raw water samples were collected from the Lower Zab river twice a month by one sample every 15 days from each station. The water quality data include 16 different parameters. Tests were carried out following the American Public Health Association standard methods. The results show that all parameters values were within the standards of drinking water proposed by the CCME standards and Iraqi standards or the World Health Organization standards for drinking purpose, except turbidity, DO, nitrate, calcium, which were mostly higher than the standards and sometimes BOD and potassium. The results of WQI showed that the water quality at LZ3 station is lower than LZ2 station due to the polluting activity of the Lower Zab river. Furthermore, for the years 2014, 2015, and 2016, the water quality was degraded due to the ISIS war. Also, it was noted in the 2013 year that the water quality degraded more in fall and winter seasons due to that the earth has exposed to the long-dried season and then suddenly exposed to a high rainfall season which in turns leads to increase some parameters very high (i.e. turbidity). Finally, the Lower Zab river water cannot be use for drinking directly. However, a pretreatment is needed before the drinking use.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2020, 29, 2; 155-171
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Ethnobotanical knowledge and folk medicinal significance of the flora of district Gujrat, Punjab, Pakistan
Autorzy:
Ali, S.S.
Hussain, K.
Nawaz, K.
Bhatti, K.H.
Bashir, Z.
Nazeer, A.
Arif, U.
Jafar, S.
Siddiqi, E.H.
Powiązania:
https://bibliotekanauki.pl/articles/2049056.pdf
Data publikacji:
2020
Wydawca:
Instytut Włókien Naturalnych i Roślin Zielarskich
Tematy:
District Gujrat
medicine
ethnomedicinal flora
survey
native people
prowincja Gujrat
lek
rośliny lecznicze używane w medycynie ludowej
rdzenni mieszkańcy
badanie ankietowe
Opis:
Introduction: Medicinal plants are the natural source of medicines used in treatment of many diseases among local communities of various countries. It is also the raw material for the pharmaceutical industry. Pakistan is a country with a variety of medicinal plants, comprehensively studied in some areas, while others still need more studies of their flora. Objectives: The study was performed to catalogue the flora of district Gujrat, Punjab, Pakistan and to assess its ethnomedicinal importance. Methods: A field survey was conducted in the Gujrat district (including Sarai Alamgir, Gujrat and Kharian) in 2019–2020 to collect the flora. Nearly 200 people of various age groups were interviewed and the questionnaire was filled, the gender and professions of the participants were also noted. Results: The plant species collected belonged to 32 different Angiosperm families i.e. Poaceae, Brassicaceae, Fabaceae, Asteraceae, Moraceae, Amaranthaceae, Apiaceae, Myrtaceae, Rutaceae, Solanaceae, Malvaceae, Euphorbiaceae and Lamiaceae. The obtained material consisted of 30 herbs, 20 shrubs and 22 trees. The floral parts used most often were leaves (63%) followed by: flower (41%), fruit (28%), stem (16%), seed (16%), bark (14%), root (13%), whole plant (12%), underground part (3%) and latex (3%). According to the study, the highest RFC (Relative Frequency of Citation) values were 0.1 in Cassia fistula L. (0.25) and the smallest RFC values were observed in Stellaria media (L.) Vill. – 0.025. The highest UV (Use Values) were noted for Achyranthes aspera L. at 0.9. In disease category, the highest value (0.67) of ICF (Informant Consensus Factor) was observed for stomach and skin infections, while the lowest ICF value was noted for diabetes and gonorrhoea (0.27). Conclusions: It was concluded that the Gujrat district is rich in useful plants that can be used in the preparation of various medicines as well as be sold on the herbal market.
Źródło:
Herba Polonica; 2020, 66, 1; 37-51
0018-0599
Pojawia się w:
Herba Polonica
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:
Application of azoxystrobin fungicide improves drought tolerance in tomato, via enhancing physio-biochemical and anatomical feature
Autorzy:
Ali, A.A.I.
Desoky, E-S.M.
Rady, M.M.
Powiązania:
https://bibliotekanauki.pl/articles/11895.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Źródło:
International Letters of Natural Sciences; 2019, 76
2300-9675
Pojawia się w:
International Letters of Natural Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of Forecasts Performance of ARIMA-GARCH-type Models in the Light of Outliers
Autorzy:
Akpan, Emmanuel Alphonsus
Lasisi, K. E.
Adamu, Ali
Rann, Haruna Bakari
Powiązania:
https://bibliotekanauki.pl/articles/1075685.pdf
Data publikacji:
2019
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
ARIMA Model
Forecast
GARCH Model
Heteroscedasticity
Outlier
Volatility
Opis:
The carry-over effect of biased estimates of ARIMA-GARCH-type models parameters on forecasting accuracy is investigated in the presence of outliers by exploring the daily returns of share price series of three major banks in Nigerian. The banks considered are Diamond, United bank for Africa and Union. The data were collected from the Nigerian Stock Exchange and spanned from January 3, 2006 to December 30, 2016, comprises 2713 observations and were divided into two portions. The first portion which ranges from January 3, 2006 to November 24, 2016, comprises 2690 observations was used for model formulation and the second portion which ranges from November 25, 2016 to December 30, 2016, consisting of 23 observations was used for out-of-sample forecasting performance evaluation. The parametric bootstrap technique was used in computing the forecasts while Mean Squared Error (MSE), Root Mean Squared Error (RMSE), Mean Absolute Error (MAE) and Mean Error (ME) were the methods of forecast evaluation considered. The findings of this study showed that in the presence of outliers, the forecasts were found to be biased as indicated by ME and the accuracy reduced as shown by MSE, RMSE and MAE. However, adjusting for the outliers, only marginal improvement on the forecasts was observed, reason being that all the outliers were treated as innovations and they occurred before the forecasts origin.
Źródło:
World Scientific News; 2019, 119; 68-84
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Energy efficiency analysis of styrene production by adiabatic ethylbenzene dehydrogenation using exergy analysis and heat integration
Autorzy:
Ali, E.
Hadj-Kali, M.
Powiązania:
https://bibliotekanauki.pl/articles/949461.pdf
Data publikacji:
2018
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
Styrene production
Ethylbenzene dehydrogenation
Exergy analysis
Heat Integration
Pinch Analysis
Heat Recovery
Opis:
Styrene is a valuable commodity for polymer industries. The main route for producing styrene by dehydrogenation of ethylbenzene consumes a substantial amount of energy because of the use of high-temperature steam. In this work, the process energy requirements and recovery are studied using Exergy analysis and Heat Integration (HI) based on Pinch design method. The amount of steam plays a key role in the trade-off between Styrene yield and energy savings. Therefore, optimizing the operating conditions for energy reduction is infeasible. Heat integration indicated an insignificant reduction in the net energy demand and exergy losses, but 24% and 34% saving in external heating and cooling duties, respectively. When the required steam is generated by recovering the heat of the hot reactor effluent, a considerable saving in the net energy demand, as well as the heating and cooling utilities, can be achieved. Moreover, around 68% reduction in the exergy destruction is observed.
Źródło:
Polish Journal of Chemical Technology; 2018, 20, 1; 35-46
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
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:
Biosorption of some toxic metals from aqueous solution using non-living algal cells of Chlorella vulgaris
Autorzy:
Goher, M.E.
Abd El-Monem, A.M.
Abdel-Satar, A.M.
Ali, M.H.
Hussian, A.-E.M.
Napiorkowska-Krzebietke, A.
Powiązania:
https://bibliotekanauki.pl/articles/13619.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Opis:
Dead cells of Chlorella vulgaris were used experimentally to remove cadmium (Cd2+), copper (Cu2+) and lead (Pb2+) ions from aqueous solution under various conditions of pH, biosorbent dosage and contact time. C. vulgaris was isolated from Lake Manzala, (Egypt) and then cultivated outdoors, in growth media, maintaining pH of nearly 7.5. After cultivation, the cells were harvested by coagulation and prepared to make an experiment with different variants of pH, contact time and adsorbent dose. The adsorption specific characteristics of C. vulgaris were examined using Fourier Transformation Infrared Spectroscopy (FTR) and Scanning Electron Microscopy (SEM). The FTIR and SEM data showed vibration frequency changes for the peaks corresponding to the surface functional groups and morphological changes of C. vulgaris, respectively, after its exposure to metal ion solution. The maximum removal efficiency for copper and lead at ambient room temperature was recorded at pH 5 and 20-minute contact time, while the contact time of 120 minutes at pH 6 created the most suitable conditions for cadmium biosorption. On the other hand, 2 g dm-3 of C. vulgaris under optimum conditions was sufficient to remove 95.5%, 97.7% and 99.4% of Cd2+, Cu2+ and Pb2+, respectively, from a mixed solution of 50 mg dm-3 of each metal ion. The removal trend was in order of Pb2+ > Cu2+ > Cd2+. The results suggested that the biomass of C. vulgaris is an extremely efficient and environmentally friendly biosorbent for the removal of Cd2+, Cu2+ and Pb2 from aqueous solutions, which may be applied on a large, industrial scale.
Źródło:
Journal of Elementology; 2016, 21, 3
1644-2296
Pojawia się w:
Journal of Elementology
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:
The isotherm and kinetic studies of the biosorption of heavy metals by non-living cells of Chlorella vulgaris
Autorzy:
Ali, Mohamed H.
Hussian, Abd-Ellatif M.
Abdel-Satar, Amaal M.
Goher, Mohamed E.
Napiórkowska-Krzebietke, Agnieszka
El-Monem, Ahmed M. Abd
Powiązania:
https://bibliotekanauki.pl/articles/962750.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Warmińsko-Mazurski w Olsztynie / Polskie Towarzystwo Magnezologiczne im. Prof. Juliana Aleksandrowicza
Opis:
In general, the biosorption of heavy metals by various types of non-living organisms appears to be a very effective, low-cost and innovative method for their removal from aquatic environments. The aim of this study was to determine the applicability of adsorption isotherms and kinetic models during the biosorbent activity of non-living Chlorella to the removal of Cd, Cu and Pb. Dead cells of Chlorella vulgaris were used to remove these heavy metals from aqueous solution in experimental conditions, i.e. under various condition of pH, biosorbent dosage and contact time. Afterwards, the Langmuir and Freundlich adsorption isotherm models and the sorption kinetic (pseudo-first and pseudo-second order models, and intraparticle diffusion) were applied to the experimental data to check the effectiveness of the removal process. The removal of heavy metals on C. vulgaris following the order of Pb+2 > Cu+2 > Cd+2 was confirmed by the maximum biosorption capacities (qmax), the Langmuir constant (b), separation factor (RL) and Freundlich intensity parameter (1/n) values. The equilibrium data were well fitted with the Langmuir and Freundlich isotherm models. The adsorption process followed the pseudo-second-order model and it suggested that such kinetics is the most effective. The present results confirmed highly efficient biosorbent activity of C. vulgaris in the removal of heavy metals, especially Cd, Cu and Pb, from aqueous solution. The environmentally friendly origin indicates that non-living cells of C. vulgaris could find many broad-scale, cost-effective and alternative applications.
Źródło:
Journal of Elementology; 2016, 21, 4
1644-2296
Pojawia się w:
Journal of Elementology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Simulation for Detecting Nonlinear Echoes from Microbubbles Packets
Autorzy:
Ali, M. G. S.
Elsayed, N. Z.
Eid, E. A.
Powiązania:
https://bibliotekanauki.pl/articles/177697.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microbubbles packets
harmonic component
acoustic
radial dynamic
pressure spectrum
Opis:
This work presents a simulation of the response of packets of microbubbles in an ultrasonic pulse-echo scan line. Rayleigh-Plesset equation has been used to predict the echo from numerically obtained radial dynamics of microbubbles. Varying the number of scattering microbubbles on the pulse wave form has been discussed. To improve microbubble-specific imaging at high frequencies, the subharmonic and second harmonic signals from individual microbubbles as well as microbubbles packets were simulated as a function of size and pressure. Two different modes of harmonic generation have been distinguished. The strength and bandwidth of the subharmonic component in the scattering spectrum of microbubbles is greater than that of the second harmonic. The pressure spectra provide quantitative and detailed information on the dynamic behaviour of ultrasound contrast agent microbubbles packet.
Źródło:
Archives of Acoustics; 2015, 40, 2; 151-157
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Approach to Design Broadband Air Backed Piezoelectric Sensor
Autorzy:
Ali, M. G. S.
Elsayed, N. Z.
Eid, E. A.
Powiązania:
https://bibliotekanauki.pl/articles/176360.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
piezoelectric
equivalent circuits
impulse response
frequency response
matching layers
z-transform
Opis:
In this work, an approach to the design of broadband thickness-mode piezoelectric transducer is presented. In this approach, simulation of discrete time model of the impulse response of matched and backed piezoelectric transducer is used to design high sensitivity, broad bandwidth, and short-duration impulse response transducers. The effect of matching the performance of transmitting and receiving air backed PZT-5A transducer working into water load is studied. The optimum acoustical characteristics of the quarter wavelength matching layers are determined by a compromise between sensitivity and pulse duration. The thickness of bonding layers is smaller than that of the quarter wavelength matching layers so that they do not change the resonance peak significantly. Our calculations show that the −3 dB air backed transducer bandwidth can be improved considerably by using quarter wavelength matching layers. The computer model developed in this work to predict the behavior of multilayer structures driven by a transient waveform agrees well with measured results. Furthermore, the advantage of this this model over other approaches is that the time signal for optimum set of matching layers can be predicted rapidly.
Źródło:
Archives of Acoustics; 2015, 40, 1; 3-10
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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