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


Tytuł:
Sustained Release of Drug Facilitated Through Chemically Crosslinked Polyvinyl Alcohol-Gelatin (PVA-GE) Hydrogels. A sustainable biomedical approach
Autorzy:
Ali, Shaukat
Ranjha, Nazar Muhammad
Ahmad, Bashir
Khan, Ayaz Ali
Hassan, Fakhr Ul
Aziz, Tariq
Alharb, Metab
Alshammari, Abdulrahman
Alasmari, Abdullah F.
Alharbi, Mousa Esa
Powiązania:
https://bibliotekanauki.pl/articles/27315648.pdf
Data publikacji:
2023
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
hydrogel
gelatin
drug release
ciprofloxacin HCl
polyvinyl alcohol
Opis:
The present study aimed to prepare hydrogel based on polyvinyl alcohol (PVA) and gelatin (Ge) and characterization of PVA/Ge hydrogel for their potential use as a sustained drug delivery system. Polyvinyl Alcohol (PVA) and-Gelatin (Ge) were cross-linked using glutaraldehyde (GA) as a crosslinking agent and hydrochloric acid (HCl) as a catalyst. Different feed polymer ratio and crosslinking agent concentration were used to prepare a series of PVA/Ge hydrogels. The obtained PVA/Ge hydrogels were investigated for dynamic and equilibrium swelling studies. The effect of polymers ratio, degree of crosslinking and pH of the medium on swelling of PVA/Ge hydrogels was investigated. Furthermore, the values of diffusion coeficient (D), volume fraction, polymer-solvent interaction parameter, molecular weight between crosslink and crosslink density were calculated. For swelling studies, 0.05M USP phosphate buffer solutions of different pH (1.2, 5.5, 6.5 and 7.5) were used. For the drug release study, ciprofloxacin HCl was loaded into selected samples as a model drug. The release of drug from these samples was performed for 12 hours in USP phosphate buffers of pH 1.2, 5.5 and 7.5. The release data from these samples were fitted into various kinetic models like zero order, first order, Higuchi and Peppas models to investigate the release mechanism. It was found that by varying the composition of PVA/Ge hydrogel and GA concentration, a significant difference was observed in drug release kinetics. FTIR spectroscopy and X-ray diffraction were used for the characterization of hydrogels. PVA/Ge hydrogel showed sustained release of the model drug at various pH values suggesting its potential use as a sustained drug delivery system.
Źródło:
Polish Journal of Chemical Technology; 2023, 25, 2; 56--65
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Does melatonin improve the yield attributes of field-droughted banana under Egyptian semi-arid conditions?
Autorzy:
Hassan, Islam F.
Gaballah, Maybelle S.
Ogbaga, Chukwuma C.
Murad, Soha A.
Brysiewicz, Adam
Bakr, Basem M.M.
Mira, Amany
Alam-Eldein, Shamel M.
Powiązania:
https://bibliotekanauki.pl/articles/2073748.pdf
Data publikacji:
2022
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
banana
deficit irrigation
evapotranspiration
melatonin
photosynthesis
Opis:
Drought is regarded as one of the environmental constraints threatening agriculture worldwide. Melatonin is a pleiotropic molecule prevalent in plants capable of promoting plant endogenous resilience to many environmental challenges including drought. Banana is an important staple food consumed in developing countries especially in Africa. In this research, we studied the role of melatonin in the growth of bananas subjected to drought under the Egyptian semi-arid conditions. To achieve this objective, a field experiment on banana (Musa spp., cv. Williams) mother plants and first ratoon was conducted on a private farm for two seasons - 2019 and 2020. Three irrigation treatments, 100, 90 and 80% irrigation water requirements (IWR) were used in conjunction with four concentrations of melatonin as a foliar spray (0 μmol, 40 μmol, 60 μmol, and 80 μmol) to determine the effect of both treatments on banana plant performance under drought. The results showed that there was a substantial difference between treatments, with the foliar application of melatonin at 80 μmol concentration improving most of the yield attributes, relative water content, total chlorophyll and proline with water deficit. However, the foliar application of the molecule lowered the biochemical characteristics mostly at 80% IWR under the Egyptian semi-arid conditions. Overall, there was a concentration-dependent response with regards to IWR for the two seasons 2019 and 2020.
Źródło:
Journal of Water and Land Development; 2022, 52; 221--231
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Parameter estimation of exponentiated exponential distribution under selective ranked set sampling
Autorzy:
Hassan, Amal S.
Elshaarawy, Rasha S.
Nagy, Heba F.
Powiązania:
https://bibliotekanauki.pl/articles/2156898.pdf
Data publikacji:
2022-12-15
Wydawca:
Główny Urząd Statystyczny
Tematy:
exponentiated exponential distribution
partial ranked set sampling
neoteric ranked set sampling
maximum likelihood method
Opis:
Partial ranked set sampling (PRSS) is a cost-effective sampling method. It is a combination of simple random sample (SRS) and ranked set sampling (RSS) designs. The PRSS method allows flexibility for the experimenter in selecting the sample when it is either difficult to rank the units within each set with full confidence or when experimental units are not available. In this article, we introduce and define the likelihood function of any probability distribution under the PRSS scheme. The performance of the maximum likelihood estimators is examined when the available data are assumed to have an exponentiated exponential (EE) distribution via some selective RSS schemes as well as SRS. The suggested ranked schemes include the PRSS, RSS, neoteric RSS (NRSS), and extreme RSS (ERSS). An intensive simulation study was conducted to compare and explore the behaviour of the proposed estimators. The study demonstrated that the maximum likelihood estimators via PRSS, NRSS, ERSS, and RSS schemes are more efficient than the corresponding estimators under SRS. A real data set is presented for illustrative purposes.
Źródło:
Statistics in Transition new series; 2022, 23, 4; 37-58
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the density and cumulative distribution functions of the exponentiated Burr XII distribution
Autorzy:
Hassan, Amal S.
Assar, Salwa M.
Ali, Kareem A.
Nagy, Heba F.
Powiązania:
https://bibliotekanauki.pl/articles/1917020.pdf
Data publikacji:
2021-12-08
Wydawca:
Główny Urząd Statystyczny
Tematy:
exponentiated Burr Type XII model
least squares estimator
maximum likelihood estimator
uniform minimum variance unbiased estimator
weighted least squares estimator
Opis:
The exponentiated Burr Type XII (EBXII) distribution has wide applications in reliability and economic studies. In this article, the estimation of the probability density function and the cumulative distribution function of EBXII distribution is considered. We examine the maximum likelihood estimator, the uniformly minimum variance unbiased estimator, the least squares estimator, the weighted least squares estimator, the maximum product spacing estimator, the Cramér–von-Mises estimator, and the Anderson–Darling estimator. We derive analytical forms for the bias and mean square error. A simulation study is performed to investigate the consistency of the suggested methods of estimation. Data relating to the wind speed and service times of aircraft windshields are used with the studied methods. The simulation studies and real data applications have revealed that the maximum likelihood estimator performs more efficiently than its remaining counterparts.
Źródło:
Statistics in Transition new series; 2021, 22, 4; 171-189
1234-7655
Pojawia się w:
Statistics in Transition new series
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
In situ methanolic solvent synthesis, spectroscopic and thermogravimetric characterizations of three new transition metal complexes of trimethoprim drug
Autorzy:
Refat, Moamen S.
Al-Humaidi, Jehan Y.
El-Sayed, Mohamed Y.
Hassan, Reham F.
Powiązania:
https://bibliotekanauki.pl/articles/1849325.pdf
Data publikacji:
2021
Wydawca:
Zachodniopomorski Uniwersytet Technologiczny w Szczecinie. Wydawnictwo Uczelniane ZUT w Szczecinie
Tematy:
complexation
trimethoprim
transition metals
TGA
thermogravimetric analysis
FTIR
Fourier transform infrared spectroscopy
ESR
kinetic thermodynamic parameters
Opis:
Trimethoprim drug (TMP) complexes of copper (II), cobalt (II), and nickel (II) were prepared and discussed by using elemental analysis (C, H, N analysis), magnetic, molar conductance, FTIR, Raman spectroscopy, electron spin resonance (ESR) and UV-vis spectroscopy analyses. TMP drug coordinated as a tridentate ligand towards the respected three metal ions through two nitrogen atoms of amino groups and nitrogen atom of pyrimidine ring which flanked between –NH2 groups, these assignments confirmed by spectroscopic, magnetic, ESR and thermogravimetric analyses with formulas [Cu(TMP)(H2O)3]Cl2, [Co(TMP)(H2O)3]Cl2 and [Ni(TMP) (H2O)]Cl2. Copper (II) and cobalt (II) complexes have an octahedral geometrical structure included one TMP molecule, three coordinated water molecules and two uncoordinated chlorine atoms while, nickel(II)–TMP complex has a tetrahedral geometric configuration that involved one TMP molecule, one coordinated water molecule and two uncoordinated chlorine atoms. The activation energies and other kinetic thermodynamic parameters were estimated based on the employed of the Coats-Redfern and Horowitz-Metzger equations. The nano–structured form of the synthesized TMP complexes was confirmed dependent on the transmission electron microscopy (TEM).
Źródło:
Polish Journal of Chemical Technology; 2021, 23, 1; 60-67
1509-8117
1899-4741
Pojawia się w:
Polish Journal of Chemical Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Involvement of ethylene synthetic inhibitors in regulating the senescence of cut carnations through membrane integrity maintenance
Autorzy:
Hassan, F.
Ali, E.
Mazrou, R.
Powiązania:
https://bibliotekanauki.pl/articles/1079037.pdf
Data publikacji:
2020
Wydawca:
Instytut Ogrodnictwa
Tematy:
cut flower
flower senescence
1-methylcyclopropene
silver nanoparticle
nitric oxide
sodium nitroprusside
vase life
membrane stability
cut carnation
Opis:
Postharvest senescence is a critical problem of carnation cut flowers, limiting their transportation and subsequent marketing chain. This study was designed to assess whether the application of 1-methylcyclopropene (1 MCP), silver nanoparticles (AgNPs), and nitric oxide (NO) released from donor sodium nitroprusside (SNP) could prolong the vase life of cut carnations through an influence on the physiological and biochemical mechanisms involved in aging process. 1-MCP was used in the concentrations of 0, 100, 200, and 300 mg·m-3; AgNPs in the concentrations of 0, 50, 100, and 150 mg·dm-3; and SNP in the concentrations of 0, 0.1, 0.2, 0.3, and 0.4 mM. All treatments significantly extended the cut flower life compared with untreated flowers, more so with 300 mg·m-3 of 1-MCP, 100 mg·dm-3 of AgNPs, or 0.3 mM of SNP. All these chemical compounds were able to considerably improve the relative water content (RWC), reduce the malondialdehyde (MDA) content and increase the membrane stability index (MSI) in petals and, therefore, maintain the membrane integrity. In addition, they decreased the activities of acetyl-CoA synthetase (ACS) and nitric oxide synthase (NOS) and, hence, depressed the production of ethylene in carnation cut flowers through downregulating the ethylene production, what prolonged the vase life. Altogether, the application of exogenous 1-MCP, AgNPs, or SNP may provide a promising avenue to improve the postharvest performance of carnation cut flowers.
Źródło:
Journal of Horticultural Research; 2020, 28, 1; 39-48
2300-5009
Pojawia się w:
Journal of Horticultural Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Heating a thermoelastic half space with a surface absorption pulsed laser using fractional order theory of thermoelasticity
Autorzy:
Tayel, Ismail M.
Hassan, Amin F.
Powiązania:
https://bibliotekanauki.pl/articles/279509.pdf
Data publikacji:
2019
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
laser radiation
surface absorption
cooling effect
fractional order theory
thermoelasticity
Opis:
In this work, the problem of illuminating a thermoelastic half space by a laser beam is solved by utilizing the fractional order theory of thermoelasticity. The assumptions that the illuminated surface is exposed to a cooling effect and free from traction are considered. The problem is solved using Laplace transform techniques. The inverse Laplace transform has been calculated in numerical fashion. The obtained results are presented graphically.
Źródło:
Journal of Theoretical and Applied Mechanics; 2019, 57, 2; 489-500
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The impact of insecticides on the cotton mealybug, Phenacoccus solenopsis (Tinsley): Efficacy on potato, a new record of host plant in Egypt
Autorzy:
Rezk, M.
Hassan, A.-N.T.
El-Deeb, M.F.
Shaarawy, N.
Dewer, Y.
Powiązania:
https://bibliotekanauki.pl/articles/66067.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
The cotton mealybug, Phenacoccus solenopsis (Tinsley) (Hemiptera: Pseudococcidae), has become a widespread pest causing serious losses in several economically important crops, particularly cotton. To the best of our knowledge this is the first record of cotton mealybug, P. solenopsis as a new pest of potato plants in Egypt. The insect was noticed on potato plants for the first time during the growing season of 2016 (mid-August 2016). Mealybug specimens were collected from infested potato plants and identified as P. solenopsis. In an attempt to control this insect pest species, seven insecticides viz. sulfoxaflor, abamectin + thiamethoxam, spirotetramat, thiamethoxam, imidacloprid, buprofezin, and pymetrozine, belonging to different chemical groups, were tested for their effect against nymphs and adult females of P. solenopsis on potato under field conditions. The obtained results indicated that sulfoxaflor, abamectin + thiamethoxam and spirotetramat had the highest efficacy against P. solenopsis recording 80.3–96.05% reduction of the insect population after 21 days of application. Thiamethoxam, imidacloprid, buprofezin and pymetrozine failed to exhibit sufficient P. solenopsis control.
Źródło:
Journal of Plant Protection Research; 2019, 59, 1
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
How do Mentha plants induce resistance against Tetranychus urticae (Acari: Tetranychidae) in organic farming?
Autorzy:
Allam, S.F.
Soudy, B.A.-N.
Hassan, A.S.
Ramadan, M.M.
Baker, D.A.
Powiązania:
https://bibliotekanauki.pl/articles/65704.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Mentha
Mentha piperita
Mentha viridis
spearmint
garden mint zob.spearmint
common mint zob.spearmint
lamb mint zob.spearmint
mackerel mint zob.spearmint
plant resistance
ecology
high performance liquid chromatography
Tetranychus urticae
Acari
Tetranychidae
Opis:
Tetranychus urticae (Acari: Tetranychidae) infesting many plants but Mentha viridis L., and Mentha piperita L., were low in number of infestation. Therefore the objective of this study was to identify the resistance of M. viridis and M. piperita plants against T. urticae by studying the external shape and internal contents of those plants. For morphological studies, dried leaves were covered with gold utilizing an Edwards Scan coat six sputter-coater. For histological studies, arrangements of Soft Tissue technique were used. For phytochemical studies, the plants were cut, dried and then high performance liquid chromatography (HPLC) was used. While feeding the mites were collected from the area between oily glands, trichomes and respiratory stomata in both mint species. The most important leaf structures in aromatic plants are the oily glands found on the external part of the leaves (both upper and lower epidermis). The number of oil glands in M. viridis leaves was greater than in M. piperita; the trichomes on the epidermis of M. viridis were greater in number than in M. piperita; the spongy mesophyll in M. viridis was much thicker than in M. piperita. The essential oils in the leaves of both mint species contained 71 compounds representing 99.61% of the total oil constituents identified from M. viridis before infestation, and 90.95% after infestation, and about 99.65% from M. piperita before infestation, and 99.98% after infestation.
Źródło:
Journal of Plant Protection Research; 2018, 58, 3
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improvement of silymarin content in cell cultures of Silybum marianum by copper sulphate elicitor
Autorzy:
Elsharnouby, M.E.
Hassan, F.A.S.
Powiązania:
https://bibliotekanauki.pl/articles/11893796.pdf
Data publikacji:
2018
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Tematy:
plant cultivation
milk thistle
Silybum marianum
herbal plant
medicinal plant
cell culture
silymarin
copper sulphate
Opis:
Silybum marianum L. (Milk thistle) extracts are the main source of silymarin that is a mixture of various flavonolignan (silybin (silibinin), silydianin and silychristin). Silymarin of milk thistle has a hepatoprotective activity for liver cirrhosis and chronic inflammatory. Silybum marianum regeneration from hypocotyl explants and evaluation of their callogenesis, growth and total flavolignan (silymarin) upon copper sulphate (as abiotic elicitor) elicitation was targeted. Copper sulphate (CuSO4) was applied in concentrations of 0, 3, 5, 7 and 9 µM to elicit the silymarin production in cultures. The elicitation periods used in this study were 2, 4, 7, 14 and 28 days. Half-strength MS medium recorded better results relative to full-strength MS one and seed incubation in the darkness at room temperature resulted in rapid germination and reached to the gar lid after 10 days. Callus fresh and dry weights as well as growth index were gradually increased with increasing the copper sulphate concentration till 5 µM while decreased thereafter at any elicitation period. With the increase of the elicitation period, the increase of the previous parameters was observed. Flavonolignan (silymarin) was positively correlated with CuSO4 levels since all levels of copper sulphate significantly enhanced its content in relative to the control. Additionally, more silymarin was accumulated after 4 or 7 days and the accumulation significantly decreased when the elicitation period reached 14 days more. The highest silymarin (flavolignan) content (11.79 and 11.67 mg g–1 DW) was obtained when 5 or 7 µM copper sulphate levels were combined with 4 days elicitation period, being about five-fold of the control.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2018, 17, 2; 105-114
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Nickelization Effect on the High Temperature Tensile Properties of Mg-0.7Y2O3 Nanocomposite
Autorzy:
Hassan, S. F.
Tun, K. S.
Patel, F.
Al-Aqeeli, N.
Gupta, M.
Powiązania:
https://bibliotekanauki.pl/articles/357046.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
magnesium
nanocomposite
high-temperature
tensile strength
deformation
Opis:
In this study, high performance magnesium-yttria nanocomposite’s room temperature, strength and ductility were significantly enhanced by the dispersion of nano-sized nickel particles using powder blending and a microwave sintering process. The strengthening effect of the dispersed nano-sized nickel particles was consistent up to 100°C and then it gradually diminished with further increases in the test temperature. The ductility of the magnesium-yttria nanocomposite remained unaffected by the dispersed nano-sized nickel particles up to 100°C. Impressively, it was enhanced at 150°C and above, leading to the possibility of the near net shape fabrication of the nanocomposite at a significantly low temperature.
Źródło:
Archives of Metallurgy and Materials; 2018, 63, 3; 1411-1415
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mg-ZrO2 nanocomposite: relative effect of reinforcement incorporation technique
Autorzy:
Hassan, S. F.
Powiązania:
https://bibliotekanauki.pl/articles/352756.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
processing
nanocomposite
magnesium
microstructure
tensile properties
Opis:
In tins study, ingot metallurgy and powder metallurgy processes were used to incorporate 0.2 and 0.7 vol% of nano-size ZrO2 particles reinforcement to develop magnesium nanocomposite. Both of the processing methods led to reasonably fair reinforcement distribution, substantial gram refinement and minimum porosity in the nanocomposites. Strengthening effect of nano-ZrO2 reinforcement in the magnesium matrix was greater when incorporated using the ingot metallurgy process. The matrix ductility and resistance to fracture were significantly improved due to the presence of nano-ZrO2 reinforcement when incorporated using the powder metallurgy process. Tensile fracture surfaces revealed that the less-ductile cleavage fracture mechanism of hexagonal close packed magnesium matrix has changed to more ductile mode due to the presence of nano-ZrO2 particles in all the processed nanocomposites.
Źródło:
Archives of Metallurgy and Materials; 2016, 61, 3; 1521-1528
1733-3490
Pojawia się w:
Archives of Metallurgy and Materials
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Supplemental effects of silicon nutrition on growth, quality and some physiological characters of potted chrysanthemum grown in greenhouse
Suplementacyjny wpływ żywienia krzemem na wzrost, jakość i niektóre cechy fizjologiczne doniczkowych chryzantem uprawianych w szklarni
Autorzy:
Ali, E.F.
Hassan, F.A.S.
Powiązania:
https://bibliotekanauki.pl/articles/11543323.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Tematy:
supplementation effect
silicon
membrane stability
plant growth
plant quality
plant physiology
pot chrysanthemum
chrysanthemum
greenhouse
Opis:
Potted chrysanthemum is one of the most important floriculture plants which commercially produced in greenhouses where silicon (Si) is available in limited concentration because of using several substrates as growing media. Therefore, this study was conducted to investigate the supplemental effects of Si nutrition on growth, flowering, flower longevity as well as shelf life and nutrients content of potted chrysanthemum in relation to Si application. Moreover, the effects of Si treatment on some physiological parameters i.e. chlorophyll content, stomatal resistance, membrane stability index (MSI) and total carbohydrates were also investigated. Si application as K₂SiO₃ was added whether as foliar application at 25, 75 and 125 mg L⁻¹ Si or soil drenches at 50, 100 and 150 mg L⁻¹ Si. Except plant height and leaf area, the other vegetative growth and flowering characters were improved as a result of both Si supplementation methods compared with untreated control. Flowering was earlier and shelf life was longer in Si-supplemented than nonsupplemented plants. Generally, Si application increased the macro and micronutrients concentrations (except Ca) estimated in this study. Chlorophyll content, stomatal resistance, MSI and total carbohydrates were increased among Si treated plants. Improving the floricultural traits, extending longevity and shelf life of greenhouse grown chrysanthemum may give an impact of its greenhouse commercial production if appropriate level was used.
Chryzantema doniczkowa to jedna z najważniejszych roślin, które są komercyjnie produkowane w szklarniach, gdzie krzem (Si) jest dostępny w ograniczonym stężeniu, gdyż do uprawy używane są różne podłoża. Niniejsze badanie przeprowadzono w celu zbadania skutków suplementacyjnych żywienia Si na wzrost, kwitnienie, długość życia kwiatów, a także żywotność i zawartość składników odżywczych chryzantemy doniczkowej w stosunku do aplikacji Si. Ponadto zbadano skutki zabiegów z użyciem Si na niektóre parametry fizjologiczne, to znaczy zawartość chlorofilu, działanie aparatów szparkowych, wskaźnik stabilności błon (MSI) oraz całkowitą zawartość węglowodanów. Zastosowanie Si w postaci K₂SiO₃ dodano jako aplikację dolistną w ilości 25, 75 i 125 mg L⁻¹ Si lub do podłoża przy 50, 100 i 150 mg L⁻¹ Si. Z wyjątkiem wysokości roślin i obszaru liścia, w porównaniu z kontrolą bez żadnych zabiegów, wszystkie cechy wzrostu i kwitnienia polepszyły się w wyniku zastosowania obu metod suplementacji. Kwitnienie było wcześniejsze, a żywotność dłuższa u roślin z suplementacją Si niż u roślinach bez suplementacji. Generalnie zastosowanie Si zwiększało stężenie makro- i mikroskładników (z wyjątkiem Ca) ocenianych w niniejszym badaniu. Zawartość chlorofilu, działanie aparatów szparkowych, MSI oraz całkowita zawartość węglowodanów zwiększały się wśród roślin z zastosowaniem Si. Polepszenie cech kwiatowych, zwiększenie długości życia i żywotności chryzantem hodowanych w szklarni może mieć wpływ na komercyjną produkcję szklarniową, jeśli zastosuje się jego odpowiedni poziom.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2016, 15, 4; 85-98
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
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:
Concentration of Copper and Lead in Market Milk and Milk Products of Bangladesh
Autorzy:
Shahriar, S. M. S.
Akther, S.
Akter, F.
Morshed, S.
Alam, M. K.
Saha, I.
Halim, M. A.
Hassan, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/412537.pdf
Data publikacji:
2014
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Tematy:
Heavy metal
copper
lead
milk
milk products
Opis:
The aim of this work is to detect and estimate the level of selected heavy metals (copper and lead) in milk and milk products in Chittagong City Corporation Areas of Bangladesh. The most important milk and milk products that are likely to be an important contributor to heavy metal exposure was selected. Total 30 samples of milk and milk products were analyzed among these 20 raw milk samples was collected from 20 dairy farms around industrial area in Chittagong City and 10 milk product samples were collected from market in Chittagong City. Detection and estimation of the level of copper and lead were carried out by using “Analytikjena Atomic Absorption Spectrophotometer, model: ZEEnit700P, Germany”. It was found that, most of all milk samples contain copper and lead copper and lead. The content of copper in most of all raw milk and milk products were in the range from 0.02 mg/kg to 0.25 mg/kg. The highest level of copper was found 0.244 mg/kg in milk products. The concentration of lead in milk and milk products were in the range from 0.007 mg/kg to 0.02 mg/kg. The highest concentration of lead was found 0.019 mg/kg in raw milk. These values were compared with standard allowable limit and also with the corresponding values of different countries available in literature.
Źródło:
International Letters of Chemistry, Physics and Astronomy; 2014, 8; 56-63
2299-3843
Pojawia się w:
International Letters of Chemistry, Physics and Astronomy
Dostawca treści:
Biblioteka Nauki
Artykuł

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