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Wyszukujesz frazę "(H.K.)." wg kryterium: Autor


Tytuł:
Przejście do statusu zatrudnionego na pełny etat: analiza empiryczna z wykorzystaniem dwurównaniowego i trójrównaniowego modelu probitowego z endogenicznym przełączaniem
Autorzy:
A, Natalia N E H R E B E C K
Powiązania:
https://bibliotekanauki.pl/articles/701591.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Źródło:
Ekonomista; 2011, 2
0013-3205
2299-6184
Pojawia się w:
Ekonomista
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Synthesis, computational, anticancerous and antiproliferative effects of some copper, manganese and zinc complexes with ligands derived from symmetrical 2,2’-diamino-4,4’-dimethyl-1,1’-biphenyl-salicylaldehyde
Autorzy:
Ababneh, Taher S.
El-Khateeb, Mohammad
Tanash, Aissar K.
AL-Shboul, Tareq M.A.
Shammout, Mohammad Jamal A.
Jazzazi, Taghreed M.A.
Alomari, Mohammad
Daoud, Safa
Talib, Wamidh H.
Powiązania:
https://bibliotekanauki.pl/articles/1849324.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
tetradentate schiff base
symmetrical metal complexes
DFT calculation
spectroscopy
anticancerous
antiproliferative
Opis:
Four new symmetrical Schiff bases derived from 2,2’-diamino-4,4’-dimethyl-1,1’-biphenyl-salicylaldehyde have been synthesized and characterized by elemental analysis and different spectroscopic techniques. The reaction of 2,2’-diamino-4,4’-dimethyl-1,1’-biphenyl with two equivalents of 5-tert-butyl-, 3,5-dinitro-, 3,5-dibromo- and 3-tert-butyl-salicylaldehyde yielded 2,2’-bis(5-tert-butyl-salicylideneamino)-4,4’-dimethyl-1,1’-biphenyl (A1) as well as the 3,5-dinitro- (A2), 3,5-dibromo- (A3) and 3-tert-butyl- (A4) substituted derivatives. The tetradentate ligands were then reacted with copper-, manganese- and zinc-acetate producing the tetra-coordinate metal complexes which were characterized by FTIR, UV-Visible spectroscopy, magnetic susceptibility and elemental analysis. Zinc complexes were characterized by 1H-NMR spectroscopy. Density functional theory (DFT) calculations at the B3LYP/6-31G(d) level of theory were carried out to fully optimize and examine the molecular geometries of complexes. Subsequently, IR vibrational and UV-Vis absorption spectra were computed and correlated with the observed values and the results are in good agreement with the experimental data. The anticancerous and antiproliferative activity of the A3 ligand and its metal complexes were determined.
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 1; 7-15
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mitigation of heat stress effects by using shade net on Washington navel orange trees grown in Al-Nubaria region, Egypt
Autorzy:
Abd El-Naby, S.K.
Esmail, A.M.A.M.
Baiea, M.H.M.
Amin, O.A.E.
Amr Abdelkhalek, A.M.
Powiązania:
https://bibliotekanauki.pl/articles/12715684.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
High temperature stress can be detrimental to plants, resulting in reduced fruit yield and increased incidences of fruit disorders. One strategy that farmers can use to maintain or increase their yields in the face of a changing climate is to adjust of farm climate by using shade net on the trees. Such, the use of shade netting on Washington navel orange planted on the sandy soil in Al-Nubaria region, Egypt were studied during two successive seasons, either using a permanent shade throughout all the season or using a moveable shade for certain period from the first of March until the end of June for every season. Growth (No. of shoots/one meter branch, No. of leaves/shoot, shoot length and chlorophyll content of the leaves, leaf area and tree canopy), macronutrients (N, P, K, Ca, Mg) and micronutrients (Fe, Zn, Mn, Cu, Na) content in the leaves, fruit characteristics (number, weight, diameter, peel thickness, total soluble solids, total acidity and ascorbic acid), yield and crop efficiency, were determined. It can be concluded that covering Washington navel orange trees grown on sandy soil with shade net especial covering the trees for certain period was very effective at protecting orange trees and led to improve the growth, increase the yield and maintain fruit quality.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 3; 15-24
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Abamectin Induced Biochemical and Histopathological Changes in the Albino Rat, Rattus Norvegicus
Autorzy:
Abd-Elhady, H.K.
Abou-Elghar, G.E.
Powiązania:
https://bibliotekanauki.pl/articles/65365.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
Abamectin (Avermectin B1a), is a natural fermentation product derived from the soil bacterium Streptomyces avermitilis. Abamectin (Avermectin B1a) is widely used as an insecticide, acaricide, and anthelmintic. The present study assessed the effects of repeated subacute and subchronic exposure to the commercial formulation of abamectin (Vertemic, 1.8% EC) in albino male rats. The toxic effects of abamectin were studied. The various biochemical parameters and histopathological changes were noted. A stomach tube was used to orally administer sublethal doses of abamectin suspended in corn oil to the rats. The animals were divided into four groups. Rats of the group T1 were orally administered a sublethal dose of 30 mg/kg body weight (b.wt.) (1/10 LD50) three times a week for 30 days and the animals in group T2 were exposed to 10 mg/kg b.wt. (1/30 LD50) for 210 days, once a week. Two control groups (C1 and C2) were used in parallel studies, where animals were administered a corn oil vehicle. At the end of the study period, blood samples were collected from all groups to measure plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) activities, and the levels of creatinine and urea. Also, total protein and RNA contents were determined in the liver and kidney tissues. Changes in biochemical parameters were more intense in male rats from group T2 than those reported in group T1. The levels of ALT, AST, urea and creatinine were significantly elevated in rats from group T2 when compared to the control. In group T2, a significant decrease in the levels of total protein and RNA in both the liver and kidneys was observed. Fertility was also significantly reduced in male rats ingesting abamectin in group T2. The number of offspring was significantly reduced. Histopathological changes were more intense in male rats from group T2 than those from group T1. In conclusion, the results of this study demonstrate that subchronic oral administration of abamectin altered some biochemical parameters which correlated with histopathological changes.
Źródło:
Journal of Plant Protection Research; 2013, 53, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Insecticidal activity and chemical composition of essential oil from Artemisia judaica L. against Callosobruchus maculatus (F.) (coleoptera: bruchidae)
Autorzy:
Abd-Elhady, H.K.
Powiązania:
https://bibliotekanauki.pl/articles/961654.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
essential oil
artemisia judaica
insecticidal activity
callosobruchus maculatus
chemical composition
gas chromatographymass spectrometry (gc/ms) analysis
Opis:
The insecticidal properties of essential oil derived via the hydro-distillation method from aerial parts of Artemisia judaica L. were tested against the cowpea weevil, Callosobruchus maculatus (Fab.) (Coleoptera: Bruchidae). The repellent activity assay of essential oil against C. maculates adults indicated that in concentrations of 63.7, 31.9, 15.9, 8.0 or 4.0 μg/cm2, the oil reduced egg laying by 92.5, 86.0, 61.8, 42.7 and 12.5%, respectively. Also, the residual-film assay showed that after 72 hours of treatment, concentrations of 50 and 40% were highly effective against the C. maculates adults. The sub-lethal effects of essential oil were investigated on fecundity and F1 progany by exposing adult females to treated seeds. Both LC25 and LC50 of essential oil significantly reduced F1 progany production compared to the control. The chemical composition of the essential oil was analyzed by GC-MS and the resulting oil piperitone (32.4%), camphor (20.6%) and (E)-ethyl cinnnamate (8.2%) were found to contain the major constituents of the oil. This provided the insecticidal properties of the essential oil against cowpea weevil.
Źródło:
Journal of Plant Protection Research; 2012, 52, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Learning structures of conceptual models from observed dynamics using evolutionary echo state networks
Autorzy:
Abdelbari, H.
Shafi, K.
Powiązania:
https://bibliotekanauki.pl/articles/91864.pdf
Data publikacji:
2018
Wydawca:
Społeczna Akademia Nauk w Łodzi. Polskie Towarzystwo Sieci Neuronowych
Tematy:
complex systems modeling
conceptual models
causal loop diagrams
computational intelligence
echo state networks
evolutionary algorithms
Opis:
Conceptual or explanatory models are a key element in the process of complex system modelling. They not only provide an intuitive way for modellers to comprehend and scope the complex phenomena under investigation through an abstract representation but also pave the way for the later development of detailed and higher-resolution simulation models. An evolutionary echo state network-based method for supporting the development of such models, which can help to expedite the generation of alternative models for explaining the underlying phenomena and potentially reduce the manual effort required, is proposed. It relies on a customised echo state neural network for learning sparse conceptual model representations from the observed data. In this paper, three evolutionary algorithms, a genetic algorithm, differential evolution and particle swarm optimisation are applied to optimize the network design in order to improve model learning. The proposed methodology is tested on four examples of problems that represent complex system models in the economic, ecological and physical domains. The empirical analysis shows that the proposed technique can learn models which are both sparse and effective for generating the output that matches the observed behaviour.
Źródło:
Journal of Artificial Intelligence and Soft Computing Research; 2018, 8, 2; 133-154
2083-2567
2449-6499
Pojawia się w:
Journal of Artificial Intelligence and Soft Computing Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Extended finite element numerical analysis of scale effect in notched glass fiber reinforced epoxy composite
Rozszerzona analiza numeryczna metodą elementów skończonych efektu skali w epoksydowym kompozycie z karbem wzmocnionym włóknem szklanym
Autorzy:
Abdellah, M. Y.
Alsoufi, M. S.
Hassan, M. K.
Ghulman, H. A.
Mohamed, A. F.
Powiązania:
https://bibliotekanauki.pl/articles/139922.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
XFEM
extended finite element method
composite laminate
fracture processing zone
crack opening displacement
rozszerzona metoda elementów skończonych
laminat kompozytowy
strefa procesu pęknięcia
przemieszczenie otworu szczeliny
Opis:
Nominal strength reduction in cross ply laminates of [0/90]2s is observed in tensile tests of glass fiber composite laminates having central open hole of diameters varying from 2 to 10 mm. This is well known as the size effect. The extended finite element method (XFEM) is implemented to simulate the fracture process and size effect (scale effect) in the glass fiber reinforced polymer laminates weakened by holes or notches. The analysis shows that XFEM results are in good agreement with the experimental results specifying nominal strength and in good agreement with the analytical results based on the cohesive zone model specifying crack opening displacement and the fracture process zone length.
Zmniejszenie nominalnej wytrzymałości laminatu warstwowego z poprzecznym ułożeniem włókien typu [0/90]2s jest obserwowane dla naprężeń rozciągających w laminatach kompozytowych z włóknem szklanym mających centralny otwór o średnicy od 2 do 10 mm. Jest to dobrze znany efekt rozmiaru (efekt skali). Rozszerzona analiza metodą elementów skończonych (XFEM) została zastosowana w celu symulacji procesu pękania i efektu skali w polimerowych laminatach z włóknem szklanym osłabionych obecnością karbu lub otworu. W pracy wykazano, że wyniki metody XFEM dotyczące wytrzymałości nominalnej są zgodne z danymi eksperymentalnymi, dobrze zgadzają sią z wynikami analitycznymi opartymi na modelu strefy spójnej i pozwalają określić przemieszczenie otworu szczeliny i długość strefy procesu pęknięcia.
Źródło:
Archive of Mechanical Engineering; 2015, LXII, 2; 217-236
0004-0738
Pojawia się w:
Archive of Mechanical Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Positive solution of a fractional differential equation with integral boundary conditions
Autorzy:
Abdo, M. S.
Wahash, H. A.
Panchal, S. K.
Powiązania:
https://bibliotekanauki.pl/articles/122788.pdf
Data publikacji:
2018
Wydawca:
Politechnika Częstochowska. Wydawnictwo Politechniki Częstochowskiej
Tematy:
fractional derivative and integral
positive solutions of nonlinear boundary value problems
upper and lower solutions
fixed point theorem
pochodna ułamkowa
twierdzenie o punkcie stałym
twierdzenia o punkcie stałym Schaudera
równania różniczkowe cząstkowe
nieliniowe cząstkowe równanie różniczkowe
zagadnienie brzegowe
Opis:
In this paper, we prove the existence and uniqueness of a positive solution for a boundary value problem of nonlinear fractional differential equations involving a Caputo fractional operator with integral boundary conditions. The technique used to prove our results depends on the upper and lower solution, the Schauder fixed point theorem and the Banach contraction principle. The result of existence obtained through constructing the upper and lower control functions of the nonlinear term without any monotone requirement.
Źródło:
Journal of Applied Mathematics and Computational Mechanics; 2018, 17, 3; 5-15
2299-9965
Pojawia się w:
Journal of Applied Mathematics and Computational Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study the Radiation Time Effect of Synthesis Silver Nanoparticles by Photo Reduction Method
Autorzy:
Abdullah, H. l.
Kadhim, K. J.
Hilal, I. H.
Powiązania:
https://bibliotekanauki.pl/articles/1192092.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
silver nanocolloids
AFM
photo reduction
Opis:
Highly stable dispersion of nanosized silver nanoparticles were prepared by the reduction of silver salt (silver nitrite - AgNO3 ) by photo reduction methods UV-lamps. The irradiation time from 6 min. to one hour effects on the morphology of dispersed silver nanoparticles were studied. The formation of silver nanoparticles characterized by means of ultraviolet-visible spectroscopy, X-ray diffraction spectroscopy and transmission electron microscopy (AFM). During the preparation of observed that the color of dispersion gradually changed from white, yellow, orange, brown finally dark brown by changing with irradiation time, it is also the acidic solutions (PH) have decreased by increasing the duration of irradiation in addition to get different nanoparticles size lies between (33.988-93.175) nm.
Źródło:
World Scientific News; 2016, 37; 220-231
2392-2192
Pojawia się w:
World Scientific News
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of shear span-to-depth ratio on behavior of sandwich core steel girder with corrugated web
Autorzy:
Abdullah, Mazin D.
Muhaisin, Muthana H.
Ammash, Haider K.
Powiązania:
https://bibliotekanauki.pl/articles/35557192.pdf
Data publikacji:
2022
Wydawca:
Szkoła Główna Gospodarstwa Wiejskiego w Warszawie. Wydawnictwo Szkoły Głównej Gospodarstwa Wiejskiego w Warszawie
Tematy:
steel beam
shear span
corrugated web
sandwich core
experimental results
Opis:
Girders with corrugated steel web are preferred and widely used in recently constructed bridges and industrial buildings. Sandwich core girders with corrugated web are constructed by adding two plates (skins) to the corrugated web. This study aims to investigate the shear span-to-depth ratio impact on the performance of sandwich core steel girders with corrugated web. Three span-to-depth ratios (a/d): 1.0, 1.833 and 2.5, were examined. The test includes three girders with sandwich web thickness of 30 mm, three girders with 60 mm sandwich web thickness, and three girders with conventional flat webs. A total of nine simply supported steel girders subjected to a concentrated load were fabricated and tested up to failure. The responses of the examined girders are presented in term of the load deflection curves, the ultimate load, and the maximum displacement. Among the conclusions drawn in this study that girders with sandwich core thickness of 30 mm demonstrate higher ultimate load capacity than girders with sandwich core of 60 mm, the maximum difference in the ultimate load capacity was about 20% and can be seen at a/d equals to 1.0. The results also pointed out that the behavior of the beams was noticeably impacted by the shear span-to-depth ratio.
Źródło:
Scientific Review Engineering and Environmental Sciences; 2022, 31, 2; 79-87
1732-9353
Pojawia się w:
Scientific Review Engineering and Environmental Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Experimental and numerical study on the effect of creep behavior on epoxy composites reinforced with yttrium oxide powder
Autorzy:
Abed, B. H.
Jadee, K. J.
Battawi, A. A.
Powiązania:
https://bibliotekanauki.pl/articles/1839719.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
kompozyt epoksydowy
tlenek itru
pełzanie
współczynnik wagowy
epoxy composite
yttrium oxide
creep
ANSYS APDL
weight ratio
Opis:
The creep test is one of the important approaches to determining some mechanical properties of composite materials. This study was carried out to investigate the creep behaviour of an epoxy composite material that was reinforced with Y2O3 powder at weight ratios of 2%, 7%, 12%, 17% and 22%. Each volume ratio was subjected to five loads over the range of 1N to5N at a constant temperature of 16 ± 2°C. In this work, creep behaviour, stress and elasticity modulus were studied through experimental and numerical analyses. Results showed that increasing the weight ratio of Y2O3 powder enhanced creep characteristics.
Źródło:
International Journal of Applied Mechanics and Engineering; 2020, 25, 4; 203-213
1734-4492
2353-9003
Pojawia się w:
International Journal of Applied Mechanics and Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High Performance Hybrid Silicon Evanescent Traveling Wave Electroabsorption Modulators
Autorzy:
Abedi, K.
Afrouz, H.
Powiązania:
https://bibliotekanauki.pl/articles/1399960.pdf
Data publikacji:
2013-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
85.35.Be
Opis:
In this paper, for the first time, a high performance hybrid silicon evanescent traveling wave electroabsorption modulator based on asymmetric intra-step-barrier coupled double strained quantum wells active layer is introduced which has double steps at III/V mesa structure. Through this active layer, hybrid silicon evanescent traveling wave electroabsorption modulator will be advantages such as very low insertion loss, zero chirp, high extinction ratio, and large Stark shift and better figures of merit as compared with multiquantum well and intra-step quantum well structures. Furthermore, traveling wave electroabsorption modulator with double steps III/V mesa structure results in a wider bandwidth as compared with one-step III/V mesa and mushroom structures. For the modulator with double steps III/V mesa structure with a 200 μm length, the 3 dB bandwidths are obtained as 132 and 52 GHz for 25 and 40 Ω characteristic impedances, respectively.
Źródło:
Acta Physica Polonica A; 2013, 123, 2; 415-417
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Sub-Nanosecond Phase Recovery in Quantum-Dot Semiconductor Optical Amplifiers
Autorzy:
Abedi, K.
Taleb, H.
Powiązania:
https://bibliotekanauki.pl/articles/1399957.pdf
Data publikacji:
2013-02
Wydawca:
Polska Akademia Nauk. Instytut Fizyki PAN
Tematy:
71.55.Eq
78.67.-n
78.67.Hc
Opis:
In this paper, optimal design of a pumping scheme for achieving the best gain and phase response in quntum-dot semiconductor optical amplifiers is investigated. For the first time, the dynamic response of the quntum-dot semiconductor optical amplifier is evaluated under three different pumping schemes, known as optical pumping, electrical pumping, and electro-optical pumping. Simulation results show that the shortest gain recovery time in quntum-dot semiconductor optical amplifiers can be achieved under the electrical pumping scheme. However, under the optical pumping and electro-optical pumping schemes, the quntum-dot semiconductor optical amplifier represents a shorter phase recovery compared to the electrical pumping scheme. We found that a sub-nanosecond phase recovery in the quntum-dot semiconductor optical amplifier can be achieved under the OP and electro-optical pumping schemes, which can never be achieved under the electrical pumping, because of the slow carrier dynamics of the carrier reservoir. Also, it was found that the gain recovery process in an optically pumped quntum-dot semiconductor optical amplifier can be significantly accelerated at cryogenic temperatures. This result demonstrates the superiorities of the optical pumping scheme over the electrical pumping and electro-optical pumping schemes at low temperatures, where both the gain and phase recovery times of an optically pumped quantum-dot semiconductor optical amplifier are drastically decreased.
Źródło:
Acta Physica Polonica A; 2013, 123, 2; 407-410
0587-4246
1898-794X
Pojawia się w:
Acta Physica Polonica A
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Element partition trees for h-refined meshes to optimize direct solver performance. Part I: Dynamic programming
Autorzy:
Aboueisha, H.
Calo, V. M.
Jopek, K.
Moshkov, M.
Paszyńska, A.
Paszyński, M.
Skotniczny, M.
Powiązania:
https://bibliotekanauki.pl/articles/330823.pdf
Data publikacji:
2017
Wydawca:
Uniwersytet Zielonogórski. Oficyna Wydawnicza
Tematy:
h-adaptive finite element method
ordering
element partition tree
extensions of dynamic programming
multifrontal direct solvers
metoda elementów skończonych
porządkowanie danych
programowanie dynamiczne
Opis:
We consider a class of two- and three-dimensional h-refined meshes generated by an adaptive finite element method. We introduce an element partition tree, which controls the execution of the multi-frontal solver algorithm over these refined grids. We propose and study algorithms with polynomial computational cost for the optimization of these element partition trees. The trees provide an ordering for the elimination of unknowns. The algorithms automatically optimize the element partition trees using extensions of dynamic programming. The construction of the trees by the dynamic programming approach is expensive. These generated trees cannot be used in practice, but rather utilized as a learning tool to propose fast heuristic algorithms. In this first part of our paper we focus on the dynamic programming approach, and draw a sketch of the heuristic algorithm. The second part will be devoted to a more detailed analysis of the heuristic algorithm extended for the case of hp-adaptive grids.
Źródło:
International Journal of Applied Mathematics and Computer Science; 2017, 27, 2; 351-365
1641-876X
2083-8492
Pojawia się w:
International Journal of Applied Mathematics and Computer Science
Dostawca treści:
Biblioteka Nauki
Artykuł

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