Skocz do pozycji: 1.

Tytuł:

Irrigation and fertigation scheduling under drip irrigation for maize crop in sandy soil

Autorzy:

Ibrahim, M.M.
El-Baroudy, A.A.
Taha, A.M.

Powiązania:

https://bibliotekanauki.pl/articles/26207.pdf

Data publikacji:

2016

Wydawca:

Polska Akademia Nauk. Instytut Agrofizyki PAN

Tematy:

irrigation
fertigation
drip irrigation
maize
yield
water productivity
crop
sandy soil
field experiment

Źródło:

International Agrophysics; 2016, 30, 1
0236-8722

Pojawia się w:

International Agrophysics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 2.

Tytuł:

Copper (II) Oxide particles as Adsorbent for Removal of Alkali Blue; Isotherm and Kinetic Studies

Autorzy:

Ibrahim, M. A.
Ibrahim, M. B.

Powiązania:

https://bibliotekanauki.pl/articles/1158766.pdf

Data publikacji:

2018

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

Adsorption
Copper (II) Oxide particles
FTIR
Isotherm
Kinetics

Opis:

Adsorption behaviour of copper (II) oxide particles (CuO-Ps) for the removal of Alkali Blue (AB) was studied. Different adsorption variables such as contact time, initial concentration and pH for the adsorption process were investigated by batch adsorption studies. FTIR was carried out to determine the functional groups present at the surface of the particle with functional groups such as –OH, C=C, C-H, C≡C detected. The percentage removal and optimum contact time for the removal of AB was 84.8% at 10 min. The experimental isotherms data were analyzed using Langmuir, Temkin, Freundlich and Dubinin-Radushkevich (D-R) isotherms and it was observed that AB fits closely to Langmuir with R2 value of 0.884. Kinetics studies shows that the adsorption process fits better to pseudo-second order with the experimental values of qe 4.242 been closer to the calculated values of the qe 4.108. Effect of pH shows that it adsorb better at the initial pH of 5.30. Lower value of mean square energy of 0.707 kJ/mol indicates that the adsorption process is physical. The results indicated that copper (II) oxide particle can be used as a low-cost adsorbent for the removal of AB from aqueous solutions.

Źródło:

World Scientific News; 2018, 114; 208-217
2392-2192

Pojawia się w:

World Scientific News

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 3.

Tytuł:

Non-linearity on pull-out test of cohesive soil using low tensile strengths of geogrids

Autorzy:

Widodo, S.
Ibrahim, A. M.

Powiązania:

https://bibliotekanauki.pl/articles/115809.pdf

Data publikacji:

2014

Wydawca:

Fundacja na Rzecz Młodych Naukowców

Tematy:

pull-out test
tensile strength
geogrid
ITD
non-linear

Opis:

Influence of geosynthetics inserted into cohesive granular soil was obviously investigated using geosynthetics-soil-interaction-testing device (ITD). Observations were already made during undertaking pull-out test, and then the results revealed that a correlation between shear stress and normal stress exhibits non-linear behaviour. In this paper, three approaches of trend-lines namely linear, logarithmic, and polynomial were compared. From analysis, polynomial trend line gave the best correlation among others. The final equation is very important part when estimating more accurate values of cohesion and friction angle design purpose.

Źródło:

Challenges of Modern Technology; 2014, 5, 1; 34-37
2082-2863
2353-4419

Pojawia się w:

Challenges of Modern Technology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 4.

Tytuł:

Mitigation of blast load risk on reinforced concrete structures considering different design alternatives

Autorzy:

Ibrahim, Y. E.
Almustafa, M.

Powiązania:

https://bibliotekanauki.pl/articles/230737.pdf

Data publikacji:

2020

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

obciążenie wybuchem
rama żelbetowa
wybuch
łagodzenie skutków
słup kompozytowy
blast loading
reinforced concrete frame
blast
mitigation
composite column

Opis:

The purpose of this study is to investigate a structure’s response to blast loading when composite columns are used instead of conventional reinforced concrete (RC) cross sections and when a conventional structure is retrofitted with braces. The study includes conducting dynamic analyses on three different structures: a conventional reference RC structure, a modified structure utilizing composite columns, and a modified structure retrofitted with steel braces. The two modified structures were designed in order to investigate their performance when subjected to blast loading compared to the conventional design. During the dynamic analyses, the structures were exposed to simulated blast loads of multiple intensities using the finite-element modelling software, SeismoStruct. To evaluate their performance, the responses of the modified structures were analyzed and compared with the response of the conventional structure. It was concluded that both the structure with composite columns and the steel brace structure experienced less damage than the conventional model. The best performance was obtained through the steel brace structure.

Źródło:

Archives of Civil Engineering; 2020, 66, 3; 225-238
1230-2945

Pojawia się w:

Archives of Civil Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 5.

Tytuł:

Bioremediation of Cu and Zn by guinea fowl feather wastes and biodegradation of Cu- and Zn-polluted feathers by free and immobilized heavy-metal-tolerant bacterium Pseudochrobactrum sp. IY-BUK1

Autorzy:

Yusuf, Ibrahim
Sharu, Amina M.

Powiązania:

https://bibliotekanauki.pl/articles/16648133.pdf

Data publikacji:

2022

Wydawca:

Polska Akademia Nauk. Czasopisma i Monografie PAN

Tematy:

bioremediation
biodegradation
immobilization
guinea fowl
feathers
heavy metals

Opis:

One of the major pollutants generated from guinea fowl farms and slaughterhouses is guinea fowl feather (GFF) wastes. Chicken feathers are an important substrate for removing aqueous pollutants due to their structural characteristics, but the application of GFFs for such purposes has not been elucidated. This study was carried out to determine the potential of raw as well as chemically and physically pretreated GFFs in the bioremediation of copper (Cu) and zinc (Zn) from aqueous solutions and the subsequent biodegradation of Cu- and Zn-laden GFFs using free and immobilized heavy-metal-tolerant bacteria. Using atomic adsorption spectrometry, the ability of treated and untreated GFFs to adsorb Cu and Zn was determined, and the generated heavy-metal-laden GFFs were degraded using Pseudochrobactrum sp. IY-BUK1. The results revealed that under optimized conditions, acetone and autoclave pretreatment enhanced Cu and Zn removal by 40% within 6 h when compared with raw GFFs. Similarly, complete biodegradation of Cu- and Zn-laden GFFs was achieved at pH 8, with 2% inoculum size, and at 25EC using IY-BUK1 in 7 days. Upon optimization of physical and nutritional conditions, using one factor at a time and response surface methodology, the maximum keratinase activity was achieved at 30EC, with 3% inoculum size and 3.5% polluted GFF concentration in 3 h. The degradation and keratinase activity were further enhanced by 50% by the immobilization of Pseudochrobactrum sp. IY-BUK1 cells compared with free cells. Thus, GFFs can act as good biosorbents, and together with IY-BUK1, the use of GFFs can be an alternative approach to dispose of GFFs, thus preventing environmental pollution via bioremediation.

Źródło:

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2022, 103, 3; 221-234
0860-7796

Pojawia się w:

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 6.

Tytuł:

Three-phases bubble column to polyethylene terephthalate depolymerization for cement mortar composites improvement

Autorzy:

Hameed, A. M.
Alzuhairi, M.
Ibrahim, S. I.

Powiązania:

https://bibliotekanauki.pl/articles/2172162.pdf

Data publikacji:

2022

Wydawca:

Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach

Tematy:

depolymerization
DPET
plastic waste
bubble column
mortar
water absorption
flexural strength
depolimeryzacja
odpady z tworzyw sztucznych
kolumna barbotażowa
zaprawa
absorpcja wody
wytrzymałość na zginanie

Opis:

Purpose This paper aims to prepare depolymerized polyethylene terephthalate (DPET) powder from recycled plastic water bottles. Adding this DPET powder to the cement mortar was also studied. Design/methodology/approach The adopted PET depolymerization process includes the usage of both ethylene glycol (EG) as solvent and nano-MgO as a catalyst. A bubble column reactor was designed for this process. Five different mortar groups were made; each has different DPET content of 0%, 1%, 3%, 6% and 9% as a sand replacement. The flexural strength test and the water absorption measurement are done after two curing periods: 7 and 28 days. Findings The research finding demonstrated that the flexural strength of mortar was reduced by increasing the DPET powder percentage and the maximum dropping was 15% when 9% of DPET was added. The ability of the mortar to absorb the water was reduced by 14.5% when DPET powder was 9%. The mortar microstructure is featured with fewer cavities and porosity. Research limitations/implications This work’s employed bubble column technique is limited only to the laboratory environment and needs to be scaled up within industrial mass production. For future research, it is suggested to decrease depolymerization time by using smaller pieces of plastic water bottle waste and trying other types of nanocatalyst. Practical implications The modified mortar can be utilized in areas where moisture, rainfalls, and sanitation systems exist. Originality/value The article claims that depolymerized waste PET improves chemical process efficiency by lowering reaction time and improving mass and heat transfer rates. Besides, this approach saves money. It is found out that the depolymerized plastic waste is much more functional due to its high cohesion capability than being used as small PET pieces.

Źródło:

Journal of Achievements in Materials and Manufacturing Engineering; 2022, 112, 1; 5--12
1734-8412

Pojawia się w:

Journal of Achievements in Materials and Manufacturing Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 7.

Tytuł:

Assessment of submerged floor water jets to minimize the scour downstream from a stepped spillway

Autorzy:

Ibrahim, Mohamed M.
Diwedar, Al Sayed Ibrahim
Ibraheem, Ahmed Mahmoud

Powiązania:

https://bibliotekanauki.pl/articles/1841974.pdf

Data publikacji:

2021

Wydawca:

Instytut Technologiczno-Przyrodniczy

Tematy:

floor jets
flume
jet rows
stepped spillway
scour depth
scour length

Opis:

Because of hydraulic jump, the scour downstream a stepped spillway is the most confusing issue that endangers the overall stability of the spillway. In this paper, thirty-six exploratory runs are described to explore the impact of utilizing submerged water jets fixed in the stilling basin of a stepped spillway on the downstream scour measurements under various flow conditions. A smooth apron where the water jets are disabled is incorporated to characterize the impact of adjustments studied. Trials are performed utilizing different upstream discharges, jets arrangements, and tailwater depths. The results are analyzed and graphically presented. The experimental data are contrasted to a scour formulae developed by other specialists. Outcomes indicated that by utilizing submerged floor water jets, the maximum scour depth is decreased between 14.3 and 36.0%. Additionally, the maximum scour length is reduced by 9.7 to 42.3%. Finally, involving regression analysis, simple formulas are developed to estimate different scour parameters.

Źródło:

Journal of Water and Land Development; 2021, 50; 122-129
1429-7426
2083-4535

Pojawia się w:

Journal of Water and Land Development

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 8.

Tytuł:

Design of a Solar Powered Reverse Osmosis System in Egypt

Autorzy:

Ibrahim, Said M. A.
Shabak, Ahmed G. M.

Powiązania:

https://bibliotekanauki.pl/articles/2052247.pdf

Data publikacji:

2021

Wydawca:

Politechnika Koszalińska. Wydawnictwo Uczelniane

Tematy:

reverse osmosis
photovoltaic
total dissolved solids
TDS
pvro
desalination
odwrócona osmoza
fotowoltaika
całkowita ilość rozpuszczonych w płynie substancji
odsalanie

Opis:

Scarcity of fresh water, forced many countries to get their water needs, or part of it, by means of saline water desalination. Reverse osmosis (RO) systems are useful tools in this concern. In case the grid electricity is not available or costly, photovoltaic (PV) power is necessary to derive RO systems. The present paper is concerned with providing a methodology for complete sizing and design of a photovoltaic reverse osmosis (PVRO) system in Egypt. Egypt has very favorable solar energy. A computer program was constructed to solve the mathematical equations of the model to get the numerical values. The program is capable of calculating the solar irradiation for any city in Egypt. Calculations and selection of the RO system with all connected pumps, the peak PV power needed, and the actual PV area were performed for different water demands ranging from 1-100 m3/day, and various water total dissolved solids (TDSs) of 5000, 15000, and 30000 mg/l. The cost of the complete PVRO system was also determined. The concern of the paper is related to water desalination and solar energy, which are responsible for our existence. The work also aims toward sustainable and clean environment via utilizing solar energy.

Źródło:

Journal of Mechanical and Energy Engineering; 2021, 5, 2; 125-140
2544-0780
2544-1671

Pojawia się w:

Journal of Mechanical and Energy Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 9.

Tytuł:

Świat musi coś zrobić : rozmowa z Ibrahimem Marghanim Abdelwahabem, sudańskim opozycjonistą

Autorzy:

Abdelwahab, Ibrahim M.
Hussein, Magda A.

Powiązania:

Rzeczpospolita 2004, nr 197, s. A6

Data publikacji:

2004

Tematy:

Uchodźcy Sudan
Obozy dla uchodźców Sudan
Pomoc humanitarna międzynarodowa Sudan
Civil war
Refugees
Refugee of camps
International humanitarian aid
Wojna domowa

Opis:

Fot.

Dostawca treści:

Bibliografia CBW

/5

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Skocz do pozycji: 10.

Tytuł:

On the Fractional Pettis and Aumann-Pettis Integral for Multifunctions

Autorzy:

Ibrahim, Ahmed-G.
Soliman, Asmaa M.

Powiązania:

https://bibliotekanauki.pl/articles/746581.pdf

Data publikacji:

2006

Wydawca:

Polskie Towarzystwo Matematyczne

Tematy:

Measurable multifunction
Aumann integral
Aumann-Pettis integral
Fractional integral

Opis:

Let \(\alpha\) be a positive real number. In the present paper we present the definition of the Aumann Pettis integral and the Pettis integral of order \(\alpha\) for multifunctions. The properties of these integrals and the relations between them are studied extensively. In particular, a Strassen type theorem in this case and continuation property are proved. Also, we give a version for Fatou's lemma and dominated convergence theorem for the Aumann-Pettis integral of order \(\alpha\) and for multifunctions.

Źródło:

Commentationes Mathematicae; 2006, 46, 2
0373-8299

Pojawia się w:

Commentationes Mathematicae

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 11.

Tytuł:

Anti-HIV activity of some natural phenolics

Autorzy:

El-Ansari, M.A.
Ibrahim, L.F.
Sharaf, M.

Powiązania:

https://bibliotekanauki.pl/articles/2049059.pdf

Data publikacji:

2020

Wydawca:

Instytut Włókien Naturalnych i Roślin Zielarskich

Tematy:

medicinal plants
phenolics
AIDS
anti-HIV activity
mechanism of action
rośliny lecznicze
związki fenolowe
działanie anty-HIV
mechanizm działania

Opis:

Acquired immunodeficiency syndrome (AIDS) is an immunosuppressive disease caused by human immunodeficiency virus (HIV). The urgent need for searching novel anti-HIV/AIDS medicines is a global concern. So far, a lot of medicinal and aromatic plants (MAPs) have been analyzed to select those that could assist in the prevention and/or amelioration of the disease. Among biologically active compounds present in these plants, one of the most promising group are phenolics. The purpose of this article was to report antiHIV activity of selected phenolic compounds of plant origin.

Źródło:

Herba Polonica; 2020, 66, 2; 34-43
0018-0599

Pojawia się w:

Herba Polonica

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 12.

Tytuł:

In vitro culture of big-sage (Lantana camara L.) plant

Autorzy:

Ibrahim, M.A.
Sabty, M.Z.
Mussa, S.H.

Powiązania:

https://bibliotekanauki.pl/articles/12710538.pdf

Data publikacji:

2020

Wydawca:

Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie

Opis:

The study was conducted to mass micropropagation of big sage (Lantana camara L.) plant by shoot multiplication technique. The treatments 2.22 and 2.66 µmol·L⁻¹ BA gave the highest significant increase in the percentage of response to shoot multiplication and number of shoots per explant compared to the other treatments as reached 96.70% and 100.00% and 4.33 and 6.00 shoots, respectively. The results showed that these two treatments did not differ significantly between them. While the 1.33 µmol·L⁻¹ BA gave the lowest values in the percentage of response to shoot multiplication and number of shoots per explant were 80.00% and 2.00 shoots per explant, respectively. The MS medium supplemented with 4.30 or 5.37 µmol·L⁻¹ NAA gave a high response to root formation, number of roots per shoot and root length. While the MS medium supplemented with 6.44 or 7.52 µmol·L⁻¹ NAA gave low values in these characteristics. The MS medium with 2.22 or 2.66 µmol·L⁻¹ concentration of BA or 7.52 µmol·L⁻¹ concentration of NAA recorded the highest significant increase in the percentage of response to callus formation. While the MS medium supplemented with 1.33 µmol·L⁻¹ BA or 4.30 µmol·L⁻¹ NAA gave less response to the callus formation.

Źródło:

Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 2; 67-73
1644-0692

Pojawia się w:

Acta Scientiarum Polonorum. Hortorum Cultus

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 13.

Tytuł:

Application of genetic algorithm for optimization the safety system of the nuclear reactor

Autorzy:

El-Sayed Wahed, M.
Ibrahim, W. Z.
Effat, A. M.

Powiązania:

https://bibliotekanauki.pl/articles/146492.pdf

Data publikacji:

2009

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

genetic algorithm
non-dominated sorting
chimney water injection system (CWIS)
Egypt nuclear

Opis:

The purpose of this paper is to present an approach to optimization in which every target is considered as a separate objective to be optimized. Multi-objective optimization is a powerful tool for resolving conflicting objectives in engineering design and numerous other fields. One approach to solve multi-objective optimization problems is the non-dominated sorting genetic algorithm (NSGA). Genetic algorithm (GA) was applied in regarding the choice of the time intervals for the periodic testing of the components of the chimney water injection system (CWIS) of the 22 MW open pool multipurpose reactor (MPR), ETRR-2, at the Egyptian Atomic Energy Authority, has been used as a case study.

Źródło:

Nukleonika; 2009, 54, 1; 51-56
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 14.

Tytuł:

Genetic algorithms and neural networks for solving water quality model of the Egyptian research reactor

Autorzy:

El-Sayed Wahed, M.
Ibrahim, W. Z.
Effat, A. M.

Powiązania:

https://bibliotekanauki.pl/articles/148150.pdf

Data publikacji:

2009

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

genetic algorithm
neural networks
model calibration
water distribution system
water quality model

Opis:

The second Egyptian research reactor ETRR-2 became critical on 27th November, 1997. The National Center of Nuclear Safety and Radiation Control (NCNSRC) has the responsibility for the evaluation and assessment of safety of this reactor. Modern managements of water distribution system (WDS) need water quality models that are able to accurately predict the dynamics of water quality variations within the distribution system environment. Before water quality models can be applied to solve system problems, they should be calibrated. The purpose of this paper is to present an approach which combines both macro and detailed models to optimize the water quality parameters. For an efficient search through the solution space, we use a multi-objective genetic algorithm which allows us to identify a set of Pareto optimal solutions providing the decision maker with a complete spectrum of optimal solutions with respect to the various targets. This new combinative algorithm uses the radial basis function (RBF) metamodeling as a surrogate to be optimized for the purpose of decreasing the times of time-consuming water quality simulation and can realize rapidly the calibration of pipe wall reaction coefficients of chlorine model of large-scaled WDS.

Źródło:

Nukleonika; 2009, 54, 4; 239-245
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 15.

Tytuł:

Parametric study simulation of axially loaded ored pile using finite element ode—Plaxis Software on subsurface soils Khartoum area-Sudan

Autorzy:

Ibrahim, A. M.
Widodo, S.
Hong, S.

Powiązania:

https://bibliotekanauki.pl/articles/115670.pdf

Data publikacji:

2012

Wydawca:

Fundacja na Rzecz Młodych Naukowców

Tematy:

bored pile
finite code
plaxis software

Opis:

The diversity and complexity of subsurface soil in studied area consisting of alluvial deposits cause many diffi culties for foundation engineering. Therefore, a solution is needed for foundation in this problematic soil. In Sudan, raft foundation represents the basic and most widespread shallow foundation method for engineering structure except for bridges where the pile foundation is used. In recent years, after the discovery of petroleum in Sudan, a major advance in piling technology is needed due to intensive building of large numbers of precast high-rise tower. This paper used Plaxis software to understand the behavior of axially loaded bored pile using different loads, lengths and diameters of piles. In this paper a comprehensive analytical study using fi nite element analysis is presented and parametric study of pile under vertical load is performed. The analytical and quantitative analysis in this study shows useful understanding of the behavior of bored pile.

Źródło:

Challenges of Modern Technology; 2012, 3, 3; 33-38
2082-2863
2353-4419

Pojawia się w:

Challenges of Modern Technology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 16.

Tytuł:

Finding optimal of the Egyptian second nuclear reactor core patterns using genetic algorithm

Autorzy:

El-Sayed Wahed, M.
Ibrahim, W. Z.

Powiązania:

https://bibliotekanauki.pl/articles/148570.pdf

Data publikacji:

2010

Wydawca:

Instytut Chemii i Techniki Jądrowej

Tematy:

reloading fuel management
nuclear reactor
genetic algorithm

Opis:

The second Egyptian research reactor ETRR-2 went critical on the 27th of November 1997. The National Center of Nuclear Safety and Radiation Control (NCNSRC) has the responsibility of the evaluation and the assessment of the safety of this reactor. Fuel management reloads for Egypt’s second research reactor have been carried out according to the fuel management scheme suggested by the reactor designer (INVAP). The start up core consists of three different fuel types, while the equilibrium core has only one fuel type called standard fuel. The fuel management scheme consists in considering the core as being partitioned into eight zones. Each zone will correspond to a chain of fuel movements. In each fuel cycle two of these chains will be involved, in which eight fuel elements will be moved, from them two spent fuel elements will be extracted and two fresh fuel elements will be inserted in the core. In this paper we solve a model as a one big nonlinear multi objective discrete optimization problem using genetic algorithm. Results are compared with INVAP values.

Źródło:

Nukleonika; 2010, 55, 3; 331-338
0029-5922
1508-5791

Pojawia się w:

Nukleonika

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 17.

Tytuł:

BV solutions of multivalued differential equations on closed moving sets in Banach spaces

Autorzy:

Benabdellah, H.
Castaing, C.
Gamal Ibrahim, M.

Powiązania:

https://bibliotekanauki.pl/articles/1359656.pdf

Data publikacji:

1995

Wydawca:

Polska Akademia Nauk. Instytut Matematyczny PAN

Opis:

This paper is concerned with the existence of BV and right continuous solutions for some classes of multivalued differential equations on closed moving sets in Banach spaces.

Źródło:

Banach Center Publications; 1995, 32, 1; 53-81
0137-6934

Pojawia się w:

Banach Center Publications

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 18.

Tytuł:

Heat shock increases oxidative stress to modulate growth and physico-chemical attributes in diverse maize cultivars

Autorzy:

Hussain, I.
Ashraf, M.A.
Rasheed, R.
Iqbal, M.
Ibrahim, M.
Ashraf, S.

Powiązania:

https://bibliotekanauki.pl/articles/25486.pdf

Data publikacji:

2016

Wydawca:

Polska Akademia Nauk. Instytut Agrofizyki PAN

Opis:

The present investigation was conducted to appraise the physiochemical adjustments in contrasting maize cultivars, namely, PakAfgoi (tolerant) and EV-5098 (sensitive) subjected to heat shock. Seven-day-old seedlings were exposed to heat shock for different time intervals (1, 3, 6, 24, 48 and 72 h) and data for various physiochemical attributes determined to appraise time course changes in maize. After 72 h of heat shock, the plants were grown under normal conditions for 5 d and data for different growth attributes and photosynthetic pigments recorded. Exposure to heat shock reduced growth and photosynthetic pigments in maize cultivars. The plants exposed to heat shock for up to 3 h recovered growth and photosynthetic pigments when stress was relieved. A time course rise in the relative membrane permeability, hydrogen peroxide (H2O2) and malondialdehyde contents was recorded particularly in the EV-5098 indicating that heat shock-induced oxidative stress. Activities of different enzymatic antioxidants greatly altered due to heat shock. For instance, an increase in superoxide dismutase activity was recorded in both maize cultivars. The activity of ascorbate peroxidase was greater in Pak-Afgoi. However, the peroxidase and catalase activities were higher in plants of EV-5098. Heat shock caused a significant rise in the proline and decline in the total free amino acids. Overall, the performance of Pak-Afgoi was better in terms of having lesser oxidative damage and greater cellular levels of proline. The results suggested that oxidative stress indicators (relative membrane permeability, H2O2 and malondialdehyde) and proline can be used as markers for heat shock tolerant plants.

Źródło:

International Agrophysics; 2016, 30, 4
0236-8722

Pojawia się w:

International Agrophysics

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 19.

Tytuł:

The modified Bagdonavičius-Nikulin goodness-of-fit test statistic for the right censored distributional validation with applications in medicine and reliability

Autorzy:

Yousof, Haitham M.
Ali, M. Masoom
Aidi, Khaoula
Ibrahim, Mohamed

Powiązania:

https://bibliotekanauki.pl/articles/18105193.pdf

Data publikacji:

2023-09-08

Wydawca:

Główny Urząd Statystyczny

Tematy:

inverted Weibull distribution
censored validation
Bagdonavičius-Nikulin
goodness-of-fit testing

Opis:

A modified version of Bagdonavičius-Nikulin goodness-of-fit statistical test is presented for validation under the right censor case. Simulation via Barzilai-Borwein algorithm is performed for assessing the right-censorship estimation method. Four right censored data sets are analyzed under the new modified test statistic for checking the distributional validation.

Źródło:

Statistics in Transition new series; 2023, 24, 4; 1-18
1234-7655

Pojawia się w:

Statistics in Transition new series

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 20.

Tytuł:

A new reciprocal Rayleigh extension: properties, copulas, different methods of estimation and a modified right-censored test for validation

Autorzy:

Yousof, Haitham M.
Ali, M. Masoom
Goual, Hafida
Ibrahim, Mohamed

Powiązania:

https://bibliotekanauki.pl/articles/1827545.pdf

Data publikacji:

2021-09-06

Wydawca:

Główny Urząd Statystyczny

Tematy:

Xgamma model
reciprocal Rayleigh model
simulations
bootstrapping
Farlie Gumbel Morgenstern copula
least squares
Cramer-Von-Mises
Ali-Mikhail-Haq copula
convexity
concavi

Opis:

In this article, a new reciprocal Rayleigh extension called the Xgamma reciprocal Rayleigh model is defined and studied. The relevant statistical properties are derived, and the useful results related to the convexity and concavity are addressed. We discussed the estimation of the parameters using different estimation methods such as the maximum likelihood estimation method, the ordinary least squares estimation method, the weighted least squares estimation method, the Cramer-Von-Mises estimation method, and the bootstrapping method. A simulation study was conducted to assess the performances of the proposed estimation methods are investigated through a simulation study. Many bivariate and multivariate type model have also been derived based on Farlie-Gumbel-Morgenstern copula, the Clayton copula, Renyi's entropy copula and the Ali-Mikhail-Haq copula. A modified Nikulin-Rao-Robson test for right-censored validation is applied to a censored real data set.

Źródło:

Statistics in Transition new series; 2021, 22, 3; 99-121
1234-7655

Pojawia się w:

Statistics in Transition new series

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 21.

Tytuł:

Structural Parameters of Functional Membranes for Integration in Smart Wearable Materials
Parametry konstrukcyjne membran użytych w „inteligentnych” materiałach

Autorzy:

Eldessouki, M.
Aysha, T.
Ratičáková, M.
Šašková, J.
Padil, V. V. T.
Ibrahim, M.
Černík, M.

Powiązania:

https://bibliotekanauki.pl/articles/232354.pdf

Data publikacji:

2017

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Biopolimerów i Włókien Chemicznych

Tematy:

colorimetric chemosensor
electrospun membranes
functional dyes
piezoresistive sensors
smart clothing
chemosensor kolorymetryczny
membrana
elektroprzędzenie
barwnik funkcjonalny
czujnik piezorezystancyjny
inteligentna odzież

Opis:

Smart clothes can be described as textiles that change their behavior under some external factors (stimulants). The response of the smart cloth can be passive (just as a sensor) or active (where a combination of sensing and another reaction takes place). The materials involved in these textiles are crucial for many applications, especially for health related applications where the “wearables” can provide instantaneous monitoring and aid to people with certain disabilities. This work consists of two main parts: First it investigates the different materials used in smart clothing for monitoring the vital activities of the human body (e.g. the breathing rates) with an emphasis on piezoresistive structures as they work sensing elements for mechanical strains. Second this work presents the production of functional membrane samples based on synthesized pyrrolinone ester hydrazone dye with a preliminary investigation of their chemical and geometrical parameters, especially their sensitivity for monitoring the presence of ammonia to function as a smart textile based colorimetric chemosensor.
„Inteligentne” ubrania można opisać jako tekstylia, które reagują pod wpływem czynników zewnętrznych (bodźców). Odpowiedź „inteligentnej” odzieży może być bierna (czujnik) lub czynna (wykrywanie i reakcja). Materiały związane z tymi wyrobami tekstylnymi mają kluczowe znaczenie dla wielu zastosowań, zwłaszcza dla tych związanych ze zdrowiem, gdzie odzież może zapewnić natychmiastowy monitoring i pomoc osobom niepełnosprawnym. Przedstawiona praca składała się z dwóch głównych części: najpierw badano różne materiały stosowane w „inteligentnej” odzieży do monitorowania istotnych czynności organizmu ludzkiego (np. szybkości oddychania), ze szczególnym uwzględnieniem struktur piezorezystancyjnych. W drugiej części pracy przedstawiono wytwarzanie funkcjonalnych membran z zastosowaniem syntetycznego barwnika, zbadano parametry chemiczne i geometryczne, w szczególności wrażliwości na monitorowanie obecności amoniaku w celu zastosowania wyrobu jako chemosensor kolorymetryczny.

Źródło:

Fibres & Textiles in Eastern Europe; 2017, 5 (125); 73-78
1230-3666
2300-7354

Pojawia się w:

Fibres & Textiles in Eastern Europe

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 22.

Tytuł:

Prediction of brittle fracture propagation behaviour of hydroxyapatite (HAp) coating in artificial femoral stem component

Autorzy:

Sheng, C.H.
Nagentrau, M.
Ibrahim, N.H.

Powiązania:

https://bibliotekanauki.pl/articles/2201136.pdf

Data publikacji:

2022

Wydawca:

Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach

Tematy:

hydroxyapatite (HAp)
fracture
stress intensity factor (SIF)
artificial femoral stem
hydroksyapatyt (HAp)
złamanie
współczynnik intensywności naprężeń
sztuczny trzon kości udowej

Opis:

Purpose: This study addresses the brittle fracture propagation behaviour modelling of hydroxyapatite (HAp) coating in artificial femoral stem component. Design/methodology/approach: A simple two dimensional flat-on-flat contact configuration finite element model consisting contact pad (bone), Ti-6Al-4V substrate and HAp coating is employed in static simulation. The HAp coating is modelled as elastic layer with pre-microcrack which assumed to be initiated due to stress singularity. Findings: The study revealed that reducing coating thickness, pre-microcrack length and artificial femoral stem elastic modulus along with increasing bone elastic modulus will result in significant stress intensity factor (SIF) to promote brittle fracture propagation behaviour. Research limitations/implications: The influence of coating thickness, pre-microcrack length, bone and artificial femoral stem elastic modulus on fracture behaviour is examined under different stress ratio using J-integral analysis approach. Practical implications: The proposed finite element model can be easily accommodating different Hap coating thickness, pre-microcrack length, bone and artificial femoral stem elastic modulus to perform detailed parametric studies with minimal costly experimental works. Originality/value: Limited research focussing on brittle fracture propagation behaviour of HAp coating in artificial femoral stem component. Thus, present study analysed the influence of coating thickness, pre-microcrack length, bone and artificial femoral stem elastic modulus on stress intensity factor (SIF) of HAp coating.

Źródło:

Archives of Materials Science and Engineering; 2022, 113, 3; 34--41
1897-2764

Pojawia się w:

Archives of Materials Science and Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 23.

Tytuł:

An Analysis of Solar Burst Type II, III, and IV and Determination of a Drift Rate of a Single Type III Solar Burst

Autorzy:

Hamidi, Z. S.
Ibrahim, M. B.
Shariff, N. N. M.
Monstein, C.

Powiązania:

https://bibliotekanauki.pl/articles/411732.pdf

Data publikacji:

2014

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

sun
solar burst
type II,III,IV
radio region
X-ray region
solar flare
active region

Opis:

The main feature of solar radio type II, III and IV burst is outlined. In this event there are three combinations of bursts that related to the solar flare phenomenon on 6th July 2012. This event is one of good example to observe how far the influence of type II burst could impact the formation of type IV burst and III solar bursts. At first stage, it was observed that a sub-type of H burst form within 2 minutes before type IV solar burst form. The type IV burst is due to the eruption of active region AR 1515 with a fine structure (FS). We used a Blein CALLISTO data in this case. Further analysis also showed that the total energy of the burst are in the range of 4.875 × 10-25 J to 8.48 × 10-25 J and plasma frequency is equal to 1.24 × 104 Hz. Therefore, we could say that in this case, before the solar burst type III occurred, the ejection of CMEs already ejected.

Źródło:

International Letters of Chemistry, Physics and Astronomy; 2014, 19, 2; 160-170
2299-3843

Pojawia się w:

International Letters of Chemistry, Physics and Astronomy

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 24.

Tytuł:

A Case Study of Explosion A Single Solar Burst Type III and IV Due to Active Region AR1890

Autorzy:

Hamidi, Z. S.
Ibrahim, M. B.
Shariff, N. N. M.
Monstein, C.

Powiązania:

https://bibliotekanauki.pl/articles/412554.pdf

Data publikacji:

2014

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

sun
solar burst
III
IV
radio region
X-ray region
solar flare
active region

Opis:

Using data from a BLEIN Callisto site, we aim to provide a comprehensive description of the synopsis formation and dynamics of a a single solar burst type III and IV event due to active region AR1890. This eruption has started since 14:15 UT with a formation of type III solar burst. To investigate the importance of the role of type III solar burst can potentially form a type IV solar burst, the literature review of both bursts is outlined in detailed. The orientation and position of AR1890 make the explosion of a class C-solar flare is not directly to the Earth. Nevertheless, it is clear that the interactions of others sunspots such as AR1893,AR1895,AR1896, AR1897 and AR1898 should be studied in detail to understand what makes the type III burst formed before the type IV solar burst.

Źródło:

International Letters of Chemistry, Physics and Astronomy; 2014, 19, 2; 171-180
2299-3843

Pojawia się w:

International Letters of Chemistry, Physics and Astronomy

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 25.

Tytuł:

Mitigation of salinity stress effects on growth, physio-chemical parameters and yield of snapbean (Phaseolus vulgaris L.) by exogenous application of glycine betaine

Autorzy:

Desoky, E-S.M.
Ibrahim, S.A.
Merwad, A-R.M.

Powiązania:

https://bibliotekanauki.pl/articles/11220.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

/5

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Skocz do pozycji: 26.

Tytuł:

Performance of Symmetric Key Cryptography Algorithms in Cloud Storage

Autorzy:

Osman, Hind
Ibrahim, Sara M.
Ali, Elmustafa Sayed

Powiązania:

https://bibliotekanauki.pl/articles/1161999.pdf

Data publikacji:

2018

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

AES
BLOWFISH
Cloud Computing
DES
Google Drive Storage
NetBeans

Opis:

Today cloud computing becomes one of the most attractive topics due to the wide opportunities that is provided which aims to enhance the electronic services to a higher-level providing cost saving, expanding possibilities, storage in demand and the huge intake capability as well. Security is one of the most important process that should be implemented in every cloud structure level, especially with data in case of processing or storing to keep it save from unauthorized access to overcome the security challenges and difficulties, which face both provider and users in cloud. In this paper a study to compare the security algorithms for encryption/decryption files has been done to evaluate the performance impact with memory capacity, processing time and algorithms running time. The comparison has been done between three encryption algorithms AES, DES, and Blowfish to determine the performance of each one in cloud storage. From the experimental results we found that DES is faster in running time compared to other algorithms as well as AES considered to be the safest one in data protection.

Źródło:

World Scientific News; 2018, 112; 244-251
2392-2192

Pojawia się w:

World Scientific News

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 27.

Tytuł:

Implementation of Printed Small Size Dual Frequency Antenna in MHz Range

Autorzy:

Eldamak, Angie R.
Ibrahim, Khalid M.
Elkattan, Mohamed

Powiązania:

https://bibliotekanauki.pl/articles/225998.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

dual frequency
meander line
MHz range
monopole antenna

Opis:

This paper presents a printed dual band monopole antenna working below 250 MHz using meander line and an added stub. Meander line approach is used to reduce the size of the low frequency monopole. The proposed antenna is fed by microstrip line and printed on FR-4 substrate with an overall size of 290 x 83 mm2. The added stub tuned dual band operation at 114 MHz and 221 MHz with measured reflection coefficient of -19 dB at both bands. The antenna has omni-directional characteristics with efficiency greater than 90% and gain of 1.87, 1.7 dBi at both bands respectively. The antenna design is optimized through a detailed parametric study. This study includes varying stub, Meander, feed and ground dimensions. The antenna has been fabricated and measured where dual band operation in the MHz range is verified.

Źródło:

International Journal of Electronics and Telecommunications; 2019, 65, 4; 565-570
2300-1933

Pojawia się w:

International Journal of Electronics and Telecommunications

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 28.

Tytuł:

Determination of integral antioxidants capacity in Syrian Hawthorn fruits and flowers using photochemiluminescence assay
Oznaczanie ogólnej zdolności przeciwutleniającej w owocach i kwiatach głogu z Syrii przy użyciu metody fotochemiluminescencyjnej

Autorzy:

Zayzafoon, G.
Odeh, A.
Ibrahim, M.
Allaf, A.W.

Powiązania:

https://bibliotekanauki.pl/articles/71723.pdf

Data publikacji:

2010

Wydawca:

Instytut Włókien Naturalnych i Roślin Zielarskich

Opis:

Syrian flora is very well known of its diversity and richness. It contains a large number of medicinal and aromatic species. There are many different hawthorn Crataegus: sinaica, aronia, monogyna and azorolus available in Syria which is mainly located in the western and southern part of the country. Most of these Syrian species are used in folk and in traditional medical care. They are taken in the form of herbal tea to contradict cough, flu and cold. There is no any scientific information available on the antioxidant properties of Syrian hawthorn medicinal plant. Therefore, the assessment of such properties remains an interesting and useful task, particularly for finding a new natural source of antioxidants available in Syria. Therefore, the integral antioxidants, IA of Syrian hawthorn fruits and flowers in five different sites as ascorbic acid equivalents have been carried out using photochemiluminescence, PCL assay of measurements for the first time. By means of a PCL assay, it was possible to assess the integral antioxidant (IA ) using this accurate and simple method, the highest antioxidant capacity values of hawthorn as ascorbic acid equivalents were found in the fruits of Bi’r Al-ajam and Al-Haffa sites which have values of 1444.82 and 483.44 (nmol/g), for C. monogyna and C. aronia cataegus, respectively. The highest fractions of antioxidant components are mainly due to the existence of catechin and flavonoids in both Syrian hawthorn fruit and flowers. Other chemical constituents like elemicin, sorbistat, polygalitol and homocatechol are found in Syrian hawthorn fruit and flowers. The measured values are considered to be the highest among countries of the region.
Flora Syrii wykazuje dużą różnorodność. W Syrii występuje wiele gatunków z rodzaju głóg Crataegus: sinaica, aronia, monogyna i azorolus. Są one głównie spotykane w zachodniej i południowej części kraju. Wiele z syryjskich gatunków z rodzaju Crataegus jest używanych w medycynie ludowej i tradycyjnej w postaci herbatek ziołowych w leczeniu kaszlu, grypy i przeziębienia. Brak jest naukowych doniesień na temat właściwości przeciwutleniających syryjskich gatunków głogu. Z tego powodu badanie tych właściwości jest interesujące i użyteczne, zwłaszcza w celu znalezienia nowych źródeł przeciwutleniaczy dostępnych na terenie Syrii. W artykule przedstawiono oznaczenia sumy antyoksydantów (ang. Integral antioxidants, IA ) w przeliczeniu na kwas askorbinowy, wykonane dla syryjskich głogów (owoców i kwiatów), zebranych z pięciu różnych stanowisk. Oznaczenia te po raz pierwszy wykonane były przy zastosowaniu metody fotochemiluminescencyjnej (ang. PCL assay). Stwierdzono, że najwyższa wartość zdolności przeciwutleniających w przeliczeniu na kwas askorbinowy została oznaczona dla owoców ze stanowisk Bi’r Al.-ajam i Al.-Haffa, dla których wartości te wyniosły odpowiednio 1444,82 i 483,44 (nmol/g). Otrzymane wartości można uważać za najwyższe w stosunku do wartości podawanych w innych państwach w tym regionie.

Źródło:

Herba Polonica; 2010, 56, 2
0018-0599

Pojawia się w:

Herba Polonica

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 29.

Tytuł:

Responses of grofth of ladys fingers (Abelmoschus esculentus L.) to different treatments methods of dairy wastewater

Autorzy:

Al-Dulaimi, R.I.
Ismail, N.
Ibrahim, M.H.

Powiązania:

https://bibliotekanauki.pl/articles/51987.pdf

Data publikacji:

2014

Wydawca:

Instytut Medycyny Wsi

Źródło:

Annals of Agricultural and Environmental Medicine; 2014, 21, 1
1232-1966

Pojawia się w:

Annals of Agricultural and Environmental Medicine

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 30.

Tytuł:

Influence of multi extrusion die process on mechanical and chemical behavior of 2024-T3 alloy

Autorzy:

Razooqi, Ahmed Ibrahim
Abbas, Naseer M.
Ghazi, Sara Saad

Powiązania:

https://bibliotekanauki.pl/articles/2174206.pdf

Data publikacji:

2022

Wydawca:

Uniwersytet Zielonogórski. Oficyna Wydawnicza

Tematy:

wyciskanie
odkształcenie plastyczne
korozja elektrochemiczna
Al 2024-T3
extrusion
plastic deformation
electrochemical corrosion

Opis:

In this paper, a cold multi-pass extrusion process for a 15mm in diameter solid 2024-T3 aluminum alloy rod was carried out using three dies to obtain three different diameters of 14mm, 13mm, and 12mm. The microstructure, hardness, and corrosion behavior were investigated before and after the extrusion process. Load-Displacement data were recorded during each extrusion process. The electrochemical corrosion test was made in a 3.5 wt.% NaCl solution using potentiostat instrument under static potentials test. Corrosion current was recorded to determine the corrosion rate for specimens. The results showed that the extrusion load increased with the number of extrusion passes, which is also seen in hardness test results. In addition, the corrosion rate decreased with the increase in the number of extrusion passes. This is due to severe plastic deformation, which generates a fine grain structure of (AlCu) and (AlCuMg) components.

Źródło:

International Journal of Applied Mechanics and Engineering; 2022, 27, 3; 163--170
1734-4492
2353-9003

Pojawia się w:

International Journal of Applied Mechanics and Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 31.

Tytuł:

A performance analysis of a hybrid golden section search methodology and a nature-inspired algorithm for MPPT in a solar PV system

Autorzy:

Mostafa, Hazem H.
Ibrahim, Amr M.
Anis, Wagdi R.

Powiązania:

https://bibliotekanauki.pl/articles/141645.pdf

Data publikacji:

2019

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

hybrid optimization
golden sections search
multi-verse optimization algorithm
maximum power point tracking
perturb and observe
photovoltaic (PV)

Opis:

This research presents a comparative study for maximum power point tracking (MPPT) methodologies for a photovoltaic (PV) system. A novel hybrid algorithm golden section search assisted perturb and observe (GSS-PO) is proposed to solve the problems of the conventional PO (CPO). The aim of this new methodology is to boost the efficiency of the CPO. The new algorithm has a very low convergence time and a very high efficiency. GSS-PO is compared with the intelligent nature-inspired multi-verse optimization (MVO) algorithm by a simulation validation. The simulation study reveals that the novel GSS- PO outperforms MVO under uniform irradiance conditions and under a sudden change in irradiance.

Źródło:

Archives of Electrical Engineering; 2019, 68, 3; 611-627
1427-4221
2300-2506

Pojawia się w:

Archives of Electrical Engineering

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 32.

Tytuł:

Minerals content, essential oils composition and physicochemical properties of Citrus jambhiri Lush. (Rough Lemon) from the Sudan

Autorzy:

Mohammed, A. M. H.
Ibrahim, M. A
Omran, A. A.
Mohamed, E. M.
Elsheikh, S. E. M.

Powiązania:

https://bibliotekanauki.pl/articles/412508.pdf

Data publikacji:

2013

Wydawca:

Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN

Tematy:

Citrus jambhiri
Rutaceae
atomic absorption spectroscopy (AAS)
Flame Atomic Emission Spectroscopy (FAES)
metal content
essential oils

Opis:

Minerals content of Citrus jambhiri (rough lemon) fruit was qualitatively and quantitatively analyzed using atomic absorption spectroscopy (AAS) and flame atomic emission spectrometry (FAES). The peel, moisture and ash contents of rough lemon were found to be 18.35 %, 23.75 % and 2.04 % respectively. Vitamin C (ascorbic acid) of rough lemon juice was found to be 70.0 mg/100 g. The chemical composition of essential oil of rough lemon peel was determined. The major compound was found to be limonene (84.5 %) followed by sabinene, β-myrcene, α-terpineol, 1,3-tetradecadiene and linalool.

Źródło:

International Letters of Chemistry, Physics and Astronomy; 2013, 9, 1; 25-30
2299-3843

Pojawia się w:

International Letters of Chemistry, Physics and Astronomy

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 33.

Tytuł:

Framework of performance measurement practices within construction companies in Egypt

Autorzy:

Dziekoński, K.
Ibrahim, O. H. M. F.
Mahamadu, A.-M.
Manu, P.

Powiązania:

https://bibliotekanauki.pl/articles/125609.pdf

Data publikacji:

2018

Wydawca:

Politechnika Białostocka. Oficyna Wydawnicza Politechniki Białostockiej

Tematy:

performance
measurement system
construction
industry
Egypt
wydajność
system miar
budowa
przemysł
Egipt

Opis:

The construction industry is considered as one of the most important sectors in Egypt. One of the major challenges faced by the industry, however, is the unavailability of suitable performance measurement systems for assessing companies’ performance. Modern performance assessment systems adopt a more universal approach to the measurement of construction company performance as opposed to the traditional project triangle. This paper aims to examine the practice of performance measurement in the Egyptian construction industry. Results show dominant role of in-house developed performance management systems as well as the use of KPIs as a method of performance assessment. The study further reveals that the highest importance is given to measures related to the time of project delivery, quality of works, clients’ satisfaction and profitability. Hence, the traditional project triangle of project’s success is the most prevalent approach to performance evaluation in the construction industry in Egypt. However, a shift towards a more holistic approach to performance assessment in larger companies was observed.

Źródło:

Engineering Management in Production and Services; 2018, 10, 2; 7-14
2543-6597
2543-912X

Pojawia się w:

Engineering Management in Production and Services

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 34.

Tytuł:

Characterization of a molybdenum-reducing bacterium with the ability to degrade phenol, isolated in soils from Egypt

Autorzy:

Ibrahim, Y.
Abdel-Mongy, M.
Shukor, M.S.
Hussein, S.
Ling, A.P.K.
Shukor, M.Y.

Powiązania:

https://bibliotekanauki.pl/articles/80115.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

molybdenum
molybdenum-reducing bacteria
contaminated soil
bioremediation
nonylphenol
phenol
Egypt

Źródło:

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2015, 96, 3
0860-7796

Pojawia się w:

BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 35.

Tytuł:

Coping with the heteroscedasticity in applied research - a comparison of three methods of food expenditure estimation in Northern Ghanas rural households
Problem heteroskedastyczności w badaniach empirycznych - porównianie trzech metod w obliczaniu wydatków na żywność w gospodarstwach rolnych w północnej Ghanie

Autorzy:

Meng, T.
Florkowski, W.J.
Ibrahim, M.
Kolovalli, S.

Powiązania:

https://bibliotekanauki.pl/articles/870143.pdf

Data publikacji:

2013

Wydawca:

The Polish Association of Agricultural and Agribusiness Economists

Tematy:

heteroscedasticity
applied research
comparison
research method
food expenditure
estimation
Ghana
rural household

Opis:

This study explores the determinants of food expenditures in northern Ghana’s rural households, using a survey data collected in 2010 in the vicinity of Tamale, the capital of the Northern Region. Three estimation methods (OLS, OLS with robust error, and WLS) are used in empirical models to address the possible heteroscedasticity. Models indicate that socio-demographic factors such as income, owning a tractor, age, and household composition are important factors in determining food expenditure. Similarly, farm features such as cultivation of staple or cash crops, the field size of groundnuts, as well as buying dry goods in bulk are also found to be major determinants. Results provide useful information for both private and public sector decision makers, while supplying ample evidence of the importance of estimation method selection to generate most accurate quantified effects of individual explanatory variables on food expenditure.
Celem badań było zidentyfikowanie determinantów wydatków na żywność w wiejskich gospodarstwach domowych w Ganie, na podstawie danych z ankiety przeprowadzonej w 2010 r. w okolicy Tamale, stolicy Regionu Północnego. Aby wykluczyć heteroskedastyczność do obliczenia modelu użyto trzech metod – MNK, MNK z poprawionymi błędami oraz WMNK. Otrzymane wyniki wskazują na czynniki socjodemograficzne (dochód, posiadanie ciągnika, wiek i skład rodziny), jako czynniki determinujące wydatki na żywność. Stwierdzono, że uprawa podstawowych roślin i tych przeznaczonych na sprzedaż (np. orzeszki ziemne) oraz niektóre inne zmienne, jak np. zakup produktów suchych w ilościach hurtowych, były statystycznie istotne. Wyniki dostarczały informacji o przydatnych w podejmowaniu decyzji zarówno w sektorze prywatnym, jak i publicznym, jednocześnie podkreślają wagę wyboru metody umożliwiającej najdokładniejszą ocenę wpływu poszczególnych zmiennych na wydatki przeznaczone na zakup pożywienia.

Źródło:

Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu; 2013, 15, 6
1508-3535
2450-7296

Pojawia się w:

Roczniki Naukowe Stowarzyszenia Ekonomistów Rolnictwa i Agrobiznesu

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 36.

Tytuł:

A comparative study of 2DOF PID and 2DOF fractional order PID controllers on a class of unstable systems

Autorzy:

Bingi, K.
Ibrahim, R.
Karsiti, M. N.
Hassan, S. M.
Harindran, V. R.

Powiązania:

https://bibliotekanauki.pl/articles/229519.pdf

Data publikacji:

2018

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

fractional order controller
set-point weighting
2DOF PID
process control
unstable systems

Opis:

The proportional-integral-derivative (PID) controllers have experienced series of structural modifications and improvements. Example of such modifications are set-point weighting and fractional ordering. While the former is to achieve two-degree-of-freedom (2DOF) ability of set-point tracking and disturbance rejection, the latter is to ensure smooth control action. Therefore, this paper reviews various forms of PID controllers and provides a comparative analysis of 2DOF PID and 2DOF fractional order PID (FOPID) controllers. The paper also discusses the conversion of one PID form to another. For the comparative analysis of the various controllers, a class of unstable systems are considered. Simulation result shows that in most cases the conversion from one form to another does not significantly affect the performance of the system. It is also observed that the 2DOF controllers (2DOF PID and 2DOF FOPID) improved significantly the performance of the ordinary PID controllers.

Źródło:

Archives of Control Sciences; 2018, 28, 4; 635-682
1230-2384

Pojawia się w:

Archives of Control Sciences

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 37.

Tytuł:

Effect of oggtt on physicochemical properties, antioxidant activity and volatile compounds of noodles

Autorzy:

Bahgaat, Wafaa K.
Ibrahim, Gamil E.
Hussein, Ahmed M. S.

Powiązania:

https://bibliotekanauki.pl/articles/2057991.pdf

Data publikacji:

2022

Wydawca:

Politechnika Łódzka. Wydawnictwo Politechniki Łódzkiej

Tematy:

oggtt noodles
physicochemical properties
antioxidant
volatile compounds
makaron oggtt
właściwości fizykochemiczne
przeciwutleniacz
związki lotne

Opis:

The present investigation aimed to evaluate the effect of noodles supplementation with oggtt at (5,10,15 and 20%) on physicochemical properties, antioxidant activity as well as volatile compounds. The cooked noodles evaluation based on cooking quality like volume and cooking loss as well as colour changes. An increase in protein, fat and ash was observed with the increase of oggtt supplementation level in noodles. The whole wheat flour had the highest value of total phenolic (462.3 μg GAE g−1) compared to oggtt and all fortified noodles without cooking and after cooking. The fortification levels of 5 and 10% did not affect significantly on colour and overall acceptability of noodles. The panelists scores recommended the usage levels of 5 and 10% of oggtt noodles which did not changed significantly in comparison with control sample. The evaluation of oggtt incorporation in noodles volatile compounds performer using HS-GC/MS analysis. Thirty volatile compounds in cooked noodles after fortification with oggtt had identified. The main volatile compound herein was 2-pentyl furan, which represent 44.12, 20.14 and 18.75% in cooked control and fortified noodles with oggtt at 5 and 10% respectively.

Źródło:

Biotechnology and Food Science; 2022, 84, 1; 3--18
2084-0136
2299-6818

Pojawia się w:

Biotechnology and Food Science

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 38.

Tytuł:

On a mixed-type integral equation and fractional-order functional differential equations

Autorzy:

El-Sayed, A. M. A.
Sherif, Nagwa
Ibrahim, I. A.

Powiązania:

https://bibliotekanauki.pl/articles/745693.pdf

Data publikacji:

2005

Wydawca:

Polskie Towarzystwo Matematyczne

Tematy:

Nonlinear functional integral equation
fractional calculus
Volterra operator
mixed type integral equation
Schauder fixed point theorem

Opis:

In this paper we study the existence of solution of a nonlinear integral equation of (mixed type) Volterra-Fredholm type. As an application we prove the existence of solution of an initial value problem of fractional order in the space of Lebesgue integrable functions on the interval \([0, 1]\).

Źródło:

Commentationes Mathematicae; 2005, 45, 2
0373-8299

Pojawia się w:

Commentationes Mathematicae

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 39.

Tytuł:

Logistical Advantages Due to the Use of an Innovative Sensor Unit for Controlling Optimum Biogas Processes

Autorzy:

Schlegel, M.
Fras, J.
Geick, T.
Zosel, J.
Schelter, M.
Kritzner, A.
Orth, M.
Ibrahim, B.
Kanswohl, N.

Powiązania:

https://bibliotekanauki.pl/articles/409594.pdf

Data publikacji:

2016

Wydawca:

Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej

Tematy:

remote control
biogas process
sensor unit

Opis:

For imaging of the biogas process fast and long-term stable measurement methods misses for certain parts of the process. Thus, it is necessary to know the development of organic acids. These metabolites, which are generated during the bacterial degradation, are important indicators. The process is generally very confusing, not only in terms of the number of occurring bacteria and chemical compounds, but also their variabilities. For the knowledge of such changes a direct, low-wear and permanent monitoring of organic acids would be extremely useful. Upon the occurrence of a change like hyperacidity we could react quickly. There are already some proven methods. However, these methods have several disadvantages: the information gathering is logistically difficult by long journeys, by process conditions information’s are delayed and distorted, quickly worn sensors, etc. Therefore, a innovative development is presented here, which avoids all the disadvantages listed. The sensor unit has been developed in cooperation with KSI Meinberg, Logic Way Schwerin, IBZ Hohen Luckow, University of Rostock and a polish colleague. According to Raoult law a characteristic is used in principle, which is typical of some liquid and gaseous media that are touching. This means volatile substances, which for example, are also in the fermenter broth, among others organic acids, are also detectable in the gaseous phase. If in the gas phase such acids can be detected, conclusions about the acid content in the substrate broth are possible. In different experiments evaluable matches between the developments of organic acids on the one hand in the liquid phase (broth) and on the other hand, in the gaseous phase were found. These results are based on an acid sensor unit with which distant standing biogas plants can be controlled remotely. A project regarding this topic is supported by research programme ZIM. Project executing organization is AiF (Arbeitsgemeinschaft industrieller Forschungsvereinigungen “Otto von Guericke” e.V.).

Źródło:

Research in Logistics & Production; 2016, 6, 5; 407-418
2083-4942
2083-4950

Pojawia się w:

Research in Logistics & Production

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 40.

Tytuł:

Hydrometallurgical treatment of non-sulfide zinc ore for precipitation of zinc oxide nanoparticles

Autorzy:

Abdel-Aal, E.-S. A.
Rashad, M. M.
El-Shazly, A. N.
Ibrahim, I. A.
El-Shahat, M. F.

Powiązania:

https://bibliotekanauki.pl/articles/110748.pdf

Data publikacji:

2016

Wydawca:

Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej

Tematy:

zinc ore
sulfuric acid leaching
filtration rate
zinc sulfate
zinc oxide nanoparticles
MB photocatalytic degradation

Opis:

Acid leaching of Egyptian zinc ore from the Um Gheig area was carried out with sulfuric acid. This study determines the optimum conditions for dissolution of non-sulfide zinc ore. The optimum conditions are 25% -74m particle size, 45 °C temperature, 2 h leaching time, 1.1 stoichiometric molar ratio of H2SO4 to Zn, 1:3 solid/liquid ratio. The maximum filtration rate is 1.6 Mg Zn•m-2•day-1at pressure difference of 0.80 bar. The zinc recovery is about 90%. As the zinc ore contains zinc silicate, some additives were tested to enhance filtration and prevent formation of silica gel. To increase the added value of the product, zinc oxide was precipitated by a co-precipitation method in a nanosize powder with average particle size ~ 20 nm. Photocatalytic degradation of methylene blue dye under UV light using ZnO nanopowders produced at different conditions was investigated. Photocatalytic efficiency with methylene blue (MB) concentration was reduced as much as 85% in 240 min with the produced nanoparticles.

Źródło:

Physicochemical Problems of Mineral Processing; 2016, 52, 2; 729-737
1643-1049
2084-4735

Pojawia się w:

Physicochemical Problems of Mineral Processing

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 41.

Tytuł:

Research the effect of the fractional number slots of pole on wind turbine generation using the enhanced spotted hyena optimization algorithm
Badanie wpływu ułamkowej liczby szczelin biegunów na generację turbiny wiatrowej przy użyciu ulepszonego algorytmu optymalizacjicętkowanej hieny

Autorzy:

Aladwan, Ibrahim M.
AL Dabbas, Hasan Abdelrazzaq
Maqableh, Ayman. M.
Fayyad, Sayel M.
Miroshnyk, Oleksandr
Shchur, Taras
Ptashnyk, Vadym

Powiązania:

https://bibliotekanauki.pl/articles/27315448.pdf

Data publikacji:

2023

Wydawca:

Politechnika Lubelska. Wydawnictwo Politechniki Lubelskiej

Tematy:

wind turbine generation
optimal slot
pole
ESHO algorithm
generacja turbiny wiatrowej
optymalna szczelina
biegun
algorytm ESHO

Opis:

The design of machines with permanent magnets is actively developing day by day and is often used in wind energy. The main advantages of such variable speed drives are high efficiency, high power density and torque density. When designing a wind generator with two rotors and permanent magnets, it is necessary to solve such a problem as the correct choice of the number of poles and slots to increase efficiency and minimize the cost of the machine. In this work, an improved spotted hyena optimization algorithm is used to obtain the optimal combination of slots and poles. This optimization algorithm makes it possible to obtain the number of fractional slots per pole and evaluate the operating efficiency of a wind generator with a double rotor and ferrite magnets. At the first stage of machine design, various combinations of slots are installed. Next, the optimal combination is selected from various slot-pole combinations, taking into account the Enhanced Spotted Hyena Optimization (ESHO) algorithm, in which a multiobjective function is configured. Accordingly, the multi-objectives are the integration of reverse electromotive force, output torque, gear torque, flux linkage, torque ripple along with losses. Analysis of the results obtained shows that the proposed algorithm for determining the optimal slot combination is more efficient than other slot combinations. It has also been found that the choice of slot and pole combination is critical to the efficient operation of permanent magnet machines.
Projektowanie maszyn z magnesami trwałymi aktywnie rozwija się z dnia na dzień i jest często wykorzystywane w energetyce wiatrowej. Głównymi zaletami takich napędów o zmiennej prędkości są wysoka sprawność, wysoka gęstość mocy i gęstość momentu obrotowego. Podczas projektowania generatora wiatrowego z dwoma wirnikami i magnesami trwałymi konieczne jest rozwiązanie takiego problemu, jak prawidłowy dobór liczby biegunów i szczelin w celu zwiększenia wydajności i zminimalizowania kosztów maszyny. W niniejszej pracy zastosowano ulepszony algorytm optymalizacji hieny plamistej w celu uzyskania optymalnej kombinacji szczelin i biegunów. Ten algorytm optymalizacji umożliwia uzyskanie liczby ułamkowych szczelin na biegun i ocenę wydajności operacyjnej generatora wiatrowego z podwójnym wirnikiem i magnesami ferrytowymi. Na pierwszym etapie projektowania maszyny instalowane są różne kombinacje szczelin. Następnie wybierana jest optymalna kombinacja spośród różnych kombinacji szczelin i biegunów, biorąc pod uwagę algorytm Enhanced Spotted Hyena Optimization (ESHO) (ulepszony algorytm optymalizacjihieny cętkowanej hieny), w którym skonfigurowana jest funkcja wielocelowa. W związku z tym, celami wielozadaniowymi są integracja odwrotnej siły elektromotorycznej, wyjściowego momentu obrotowego, momentu obrotowego przekładni, połączenia strumienia, tętnienia momentu obrotowego wraz ze stratami. Analiza uzyskanych wyników pokazuje, że proponowany algorytm określania optymalnej kombinacji szczelin jest bardziej wydajny niż inne kombinacje szczelin. Stwierdzono również, że wybór kombinacji szczelin i biegunów ma kluczowe znaczenie dla wydajnej pracy maszyn z magnesami trwałymi.

Źródło:

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska; 2023, 13, 3; 94--100
2083-0157
2391-6761

Pojawia się w:

Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 42.

Tytuł:

Flow characteristics after installation of floating bridge in open channel

Autorzy:

Ibrahim, Mohamed M.
Eltoukhy, Mahmoud A.R.
Ghanim, Adnan D.

Powiązania:

https://bibliotekanauki.pl/articles/1844336.pdf

Data publikacji:

2021

Wydawca:

Instytut Technologiczno-Przyrodniczy

Tematy:

floating bridges
flow characteristics
flume
head loss
velocity

Opis:

A pontoon bridge, also known as a floating bridge, can be used as for pedestrian and vehicle traffic. The buoyancy of the floating bridge limits the maximum load it can carry. This research included experimental runs to study variations of open channel flow characteristics upstream and downstream a floating bridge. Eighty one runs have been carried out using a flume in a hydraulic laboratory. The experimental run program is classified into two main categories; the first investigates the velocity ratios (vds/vus) downstream and upstream the floating bridge. The second category is concerned with the energy head losses (hL) due to the presence of a floating bridge. The experimental runs are carried out using three pontoon lengths, three flow depths, six submerged depths, and three discharges. The results are analysed and graphically presented to help predict hydraulic parameters. The outcomes have shown that the floating bridge upstream, Froude number and submergence of the pontoon are the dominant parameters that affect the studied flow characteristics.

Źródło:

Journal of Water and Land Development; 2021, 49; 244-251
1429-7426
2083-4535

Pojawia się w:

Journal of Water and Land Development

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 43.

Tytuł:

Hydrothermal carbonization processes to increase the transportability of plant biomasses

Autorzy:

Schlegel, M.
Ibrahim, B.
Fras, J.
Kanswohl, N.
Zosel, J.

Powiązania:

https://bibliotekanauki.pl/articles/409568.pdf

Data publikacji:

2018

Wydawca:

Politechnika Poznańska. Wydawnictwo Politechniki Poznańskiej

Tematy:

transportability
plant biomasses
process

Opis:

Plant biomasses often have high water content and their energy and material density is too low, which significantly affects their high transport costs. Hydrothermal carbonization is a suitable method to increase the transportability of these biomasses. The produced biochar (HTC-char) is rich in carbon. Disadvantages of such carbonization process are the quality fluctuations of the biochars produced. This is also because there are to date no suitable measuring methods for the carbonization process. The paper presents a novel method, which will help to influence the carbonization process in the sense of qualitatively equivalent biochars by means of the achievable data therewith.

Źródło:

Research in Logistics & Production; 2018, 8, 2; 169-178
2083-4942
2083-4950

Pojawia się w:

Research in Logistics & Production

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 44.

Tytuł:

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) as a new insect pest on tomato plants in Egypt

Autorzy:

Ibrahim, S.S.
Moharum, F.A.
Abd El-Ghany, N.M.

Powiązania:

https://bibliotekanauki.pl/articles/65060.pdf

Data publikacji:

2015

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Opis:

Recently, the mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) was recorded as a new pest on tomato plants (Lycopersicon esculentum Mill) growing in Egypt. The mealybugs specimens were collected from tomato plants in the Qalyoubia governorate during summer season of 2014. The mealybug was identified as P. solenopsis based on the morphological characters and taxonomic key of this species. This study represents the first record of P. solenopsis as a new insect pest attacking tomato plants in Egypt.

Źródło:

Journal of Plant Protection Research; 2015, 55, 1
1427-4345

Pojawia się w:

Journal of Plant Protection Research

Dostawca treści:

Biblioteka Nauki

/5

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Skocz do pozycji: 45.

Tytuł:

Synthesis and properties of vinylpyrrolidone/ (trimethoxysilyl)propyl methacrylate gels containing different amounts of crosslinking agent
Synteza i właściwości żelu N-winylopirolidon/metakrylan3-(trimetoksysililo)propylu z różną zawartością czynnika sieciującego

Autorzy:

Mohammed, A. H.
Ahmad, M. B.
Ibrahim, N. A.
Zainuddin, N.

Powiązania:

https://bibliotekanauki.pl/articles/947044.pdf

Data publikacji:

2018

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej

Tematy:

high conversion copolymers
swelling parameters
mechanical properties
oxygen permeability
crosslinking density
kopolimery o wysokim stopniu konwersji
parametry pęcznienia
właściwości mechaniczne
przepuszczalność tlenu
gęstość sieciowania

Opis:

High conversion copolymers containing 90 wt % of N-vinylpyrrolidone (NVP) and 10 wt % of 3-(trimethoxysilyl)propyl methacrylate (TMSPM) with 0, 1, 2, 3 and 4 wt % (in conversion to mass of NVP/TMSPM) of ethylene glycol dimethacrylate (EGDMA) as crosslinker have been successfully synthesized. Proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared spectroscopy (FT-IR) were employed to characterize the resulting copolymers. The effect of EGDMA amount on the mechanical and thermal properties, swelling parameters, clarity, and oxygen permeability of the prepared xerogels and hydrogels were studied. 3 wt % of EGDMA is required to obtain clear xerogels and hydrogels. The water content (EWC), volume fraction of polymer (φ2) and weight loss during swelling decrease with increasing EGDMA content. Young’s and shear modulus (E and G) increase as EGDMA content increases, the values of E and G are 0.570–3.531 MPa and 0.217–1.359 MPa, respectively. The hydrogels were characterized in terms of modulus crosslinking density (ve and vt) and polymer-solvent interaction parameters (χ). The results are 0.220–0.613 mol/dm3 for ve, 0.105–0.441 mol/dm3 for vt, and 0.595–0.822 for χ. Thermal properties enhance by adding EGDMA whereas the oxygen permeability (P) of hydrogels decreases from 48.6 to 44.3 as water content decrease from 70.3 to 55.1.
Kopolimery zawierające 90 % mas. N-winylopirolidonu (NVP) i 10 % masmetakrylanu 3-(trimetoksysililo)propylu (TMSPM) z udziałem 0, 1, 2, 3 i 4 % mas. (w przeliczeniu na masę NVP/TMSPM) dimetakrylanu glikolu etylenowego (EGDMA) jako środka sieciującego zsyntetyzowano z wysokim stopniem konwersji. Otrzymane kopolimery charakteryzowano metodami protonowego rezonansu jądrowego (H1 NMR) i spektroskopii w podczerwieni (FT-IR). Badano wpływ udziału środka sieciującego na właściwości mechaniczne i termiczne, parametry pęcznienia, klarowność i przepuszczalność tlenu wytworzonych hydro- i kserożeli. Stwierdzono, że dodatek już 3 % mas. EGDMA wystarcza do uzyskania klarownego żelu, a w miarę zwiększania zawartości EGDMA zmniejsza się zawartość wody (EWC), ułamek objętości polimeru (φ2) oraz strata masy w procesie pęcznienia żelu NVP/TMSPM. Wartość modułu zarówno Younga (E), jak i ścinania (G) zwiększa się (E = 0,570–3,531 MPa, G = 0,217–1,359 MPa) wraz ze wzrostem udziału EGDMA w kompozycji. Wytworzone hydrożele charakteryzowano za pomocą modułów gęstości sieciowania (ve = 0,220–0,613 mol/dm3, vt = 0,105–0,441 mol/dm3) i parametru oddziaływania polimer-rozpuszczalnik (χ = 0,595–0,822). Właściwości termiczne otrzymanych hydrożeli zawierających EGDMA poprawiły się wraz ze zmniejszeniem zawartości wody (70,3–55,1), natomiast przepuszczalność tlenu się pogorszyła (P = 48,6–44,3).

Źródło:

Polimery; 2018, 63, 9; 577-585
0032-2725

Pojawia się w:

Polimery

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 46.

Tytuł:

Synthesis and monomer reactivity ratios of acrylamide with 3-(trimethoxysilyl)propyl methacrylate and tris(methoxyethoxy)vinylsilane copolymers
Współczynniki reaktywności monomerów w syntezie kopolimerów akryloamidu, metakrylanu 3-(trimetoksysililo)propylu i tris(metoksyetoksy)-winylosilanu

Autorzy:

Mohammed, A. H.
Ahmad, M. B.
Ibrahim, N. A.
Zainuddin, N.

Powiązania:

https://bibliotekanauki.pl/articles/947173.pdf

Data publikacji:

2016

Wydawca:

Sieć Badawcza Łukasiewicz - Instytut Chemii Przemysłowej

Tematy:

vinylsilane monomers
acrylamide
reactivity ratios
sequence distribution
sekwencja monomerów

Opis:

Copolymers of acrylamide (AM) with 3-(trimethoxysilyl)propyl methacrylate (TMSPMA) and tris(methoxyethoxy)vinylsilane (TMEVS) with different compositions were synthesized at low conversion by free radical polymerization in dimethylformamide (DMF) using benzoyl peroxide (BPO) as an initiator. The copolymers were characterized by Fourier transform infrared spectroscopy (FT-IR), and their thermal properties were studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The copolymers composition was determined by elemental analysis. The monomer reactivity ratios were estimated by linearization methods proposed by Fineman-Ross and Kelen-Tudos, the intersection method proposed by Mayo-Lewis and nonlinear method proposed by curve fitting procedure. The derived reactivity ratios (r1, r2) are: 1.87, 0.80 for TMSPMA-co-AM and 0.22, 1.21 for TMEVS-co-AM. Both copolymers formed blocks of one of the monomer units. The microstructure of copolymers and sequence distribution of monomers in the copolymers were calculated by statistical method based on the average reactivity ratios and found that these values are in agreement with the derived reactivity ratios.
Kopolimery akryloamidu (AM) z metakrylanem 3-(trimetoksysililo)propylu (TMSPMA) itris(metoksyetoksy)winylosilanem (TMEVS), o różnych składach, zsyntetyzowano w warunkach małej konwersji metodą wolnorodnikowej polimeryzacji w dimetyloformamidzie (DMF), z zastosowaniem nadtlenku benzoilu (BPO) jako inicjatora. Otrzymane kopolimery charakteryzowano za pomocą spektroskopii w podczerwieni z transformacją Fouriera (FT-IR), różnicowej kalorymetrii skaningowej (DSC) oraz analizy termograwimetrycznej (TGA). Skład kopolimerów ustalono metodą analizy elementarnej. Współczynniki reaktywności monomerów oszacowano metodami linearyzacji zaproponowanymi przez: Finemana-Rossa, Kelena-Tudosa, Mayo-Lewisa i metodą nieliniową z zastosowaniem procedury dopasowania krzywej. Otrzymane współczynniki reaktywności (r1, r2) wynosiły: 1,87 i 0,80 dla TMSPMA-co-AM oraz 1,21 i 0,22 dla TMEVS-co-AM. Oba kopolimery miały budowę złożoną zbloków utworzonych z jednostek monomerów składowych. Mikrostrukturę oraz sekwencję monomerów w kopolimerach wyznaczono metodą statystyczną na podstawie średnich współczynników reaktywności. Stwierdzono zgodność obliczeń z wartościami otrzymanymi doświadczalnie.

Źródło:

Polimery; 2016, 61, 11-12; 758-765
0032-2725

Pojawia się w:

Polimery

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 47.

Tytuł:

Understanding forest land conversion for agriculture in a developing country context: An application of the theory of planned behaviour among a cohort of Nigerian farmers

Autorzy:

Ibrahim, F.M.
Osikabor, B.
Olatunji, B.T.
Ogunwale, G.O.

Powiązania:

https://bibliotekanauki.pl/articles/28407578.pdf

Data publikacji:

2022

Wydawca:

Instytut Badawczy Leśnictwa

Źródło:

Folia Forestalia Polonica. Series A . Forestry; 2022, 64, 3; 117-130
0071-6677

Pojawia się w:

Folia Forestalia Polonica. Series A . Forestry

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 48.

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

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Skocz do pozycji: 49.

Tytuł:

Throughput, Spectral, and Energy Efficiency of 5G Massive MIMO Applications Using Different Linear Precoding Schemes

Autorzy:

Salah, Ibrahim
Rahouma, Kamel Hussein
Hussein, Aziza I.
Mabrook, M. Mourad

Powiązania:

https://bibliotekanauki.pl/articles/2203002.pdf

Data publikacji:

2023

Wydawca:

Polska Akademia Nauk. Czytelnia Czasopism PAN

Tematy:

throughput
massive MIMO
spectral efficiency
energy efficiency
trade-off

Opis:

On fifth-generation wireless networks, a potential massive MIMO system is used to meet the ever-increasing request for high-traffic data rates, high-resolution streaming media, and cognitive communication. In order to boost the trade-off between energy efficiency (EE), spectral efficiency (SE), and throughput in wireless 5G networks, massive MIMO systems are essential. This paper proposes a strategy for EE 5G optimization utilizing massive MIMO technology. The massive MIMO system architecture would enhance the trade-off between throughput and EE at the optimum number of working antennas. Moreover, the EE-SE tradeoff is adjusted for downlink and uplink massive MIMO systems employing linear precoding techniques such as Multiple -Minimum Mean Square Error (M-MMSE), Regularized Zero Forcing (RZF), Zero Forcing (ZF), and Maximum Ratio (MR). Throughput is increased by adding more antennas at the optimum EE, according to the analysis of simulation findings. Next, utilizing M MMSE instead of RZF and ZF, the suggested trading strategy is enhanced and optimized. The results indicate that M-MMSE provides the best tradeoff between EE and throughput at the determined optimal ratio between active antennas and active users equipment’s (UE).

Źródło:

International Journal of Electronics and Telecommunications; 2023, 69, 1; 185--191
2300-1933

Pojawia się w:

International Journal of Electronics and Telecommunications

Dostawca treści:

Biblioteka Nauki

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Skocz do pozycji: 50.

Tytuł:

Preliminary statistical analysis of anthropometrics data in related to sitting posture among college students at east coast Malaysia

Autorzy:

Ibrahim, M.H.
Ishak, N.F.
Mukhtar, N.Z.
Basir, M.H.
Said, N.A.
Mohamed, K.A.
Awang, M.E.

Powiązania:

https://bibliotekanauki.pl/articles/24200579.pdf

Data publikacji:

2022

Wydawca:

Stowarzyszenie Komputerowej Nauki o Materiałach i Inżynierii Powierzchni w Gliwicach

Tematy:

sitting posture
anthropometric data
human health
pozycja siedząca
dane antropometryczne
zdrowie człowieka

Opis:

Purpose: To statistically analyse sitting posture using anthropometrics data among college students in Malaysia. Design/methodology/approach: This study was conducted among 52 college students consisting of males and females. Data were analysed using a common statistical tool which is the Statistical Package of Sosial Science (SPSS). Findings: Preliminary analysis of data indicated that there are wider differences in standard deviation of eye sitting height compared to the previous study conducted. Research limitations/implications: This study was conducted at only one higher learning institution/college located at East Cost of Malaysia. Practical implications: The larger value of standard deviation discovered as statistical analysis performed using combined data among male and female participants suggested that data should be segregated. Originality/value: Result obtained could be used as a preliminary guideline to design any related item in related to sitting posture.

Źródło:

Archives of Materials Science and Engineering; 2022, 116, 2; 81--85
1897-2764

Pojawia się w:

Archives of Materials Science and Engineering

Dostawca treści:

Biblioteka Nauki

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