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Wyszukujesz frazę "Mohammadi, A." wg kryterium: Autor


Tytuł:
Effect of high electrostatic actuation on thermoelastic damping in thin rectangular microplate resonators
Autorzy:
Mohammadi, A. K.
Ali, N. A.
Powiązania:
https://bibliotekanauki.pl/articles/280595.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
microplate resonator
thermoelastic damping
high polarization voltage
Opis:
In this paper, a micro resonator is modeled as a thin rectangular microplate with thermoelastic damping that is actuated electrostatically. Large static deformation due to high polarization voltage is considered, and vibration of microplate occurs around the static de- flection. Due to the effect of thermoelastic damping, the frequency of vibration is a complex value that is used to determine the quality factor of thermoelastic damping. Also, the pull-in voltage is considered because nonlinear properties are more appeared when approaching the polarization voltage to the pull-in voltage.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 2; 317-329
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Virtual water evaluation for grains products in Iran. Case study: pea and bean
Ocena wirtualnej wody w produkcji ziarna w Iranie – przykład grochu i fasoli
Autorzy:
Yousefi, H.
Mohammadi, A.
Mirzaaghabeik, M.
Noorollahi, Y.
Powiązania:
https://bibliotekanauki.pl/articles/292973.pdf
Data publikacji:
2017
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
grains
virtual water trade
water crisis
water use efficiency
handel wirtualną wodą
kryzys wodny
wydajność zużycia wody
ziarno
Opis:
Shortage of water is considered as one of the most important straits of agricultural development in Iran. The main purpose of this study is to determine virtual water used to pea and bean production and water use efficiency, select the best area for cultivating these two grains and find the virtual water budget for the aforementioned grains. The results showed that among the three provinces main producers of pea in Iran, the highest virtual water of pea belongs to Lorestan with 3534 dm3·kg–1 and the lowest belongs to West Azerbaijan with 2660 dm3·kg–1 in irrigated cultivation. Water use efficiency in irrigated cultivation in Kermanshah and West Azerbaijan are at the same level; however, Kermanshah has enjoyed much more level of virtual water. For beans, the highest amount of virtual water in irrigated cultivation belongs to Lorestan (3651 dm3·kg–1) and the lowest amount refers to Markazi (2725 dm3·kg–1) and also the highest level of water use efficiency for this product refers to Markazi. Also it was found that 160.15 mln m3 of water has been exported from the country water resources by these products so virtual water budget for studied crops were negative.
Deficyt wody uznawany jest za jeden z najważniejszych problemów rozwoju rolnictwa w Iranie. Głównym celem badań przedstawionych w pracy jest oznaczenie ilości wody wirtualnej zużywanej do produkcji grochu i fasoli oraz wydajności zużycia wody, wybór najlepszych terenów do uprawy obu roślin i sporządzenie dla nich bilansu wirtualnej wody. Uzyskane wyniki wykazały, że spośród trzech prowincji – głównych producentów grochu w Iranie – największą objętość wirtualnej wody (3534 dm3·kg–1) zużywa się do nawadnianych upraw w Lorestanie, a najmniejszą (2660 dm3·kg–1) – do nawadnianych upraw w prowincji Zachodni Azerbejdżan. Wydajność zużycia wody w nawadnianych uprawach w Kermanshah i Zachodnim Azerbejdżanie była podobna, a uprawy w Kermanshah cechowało większe zużycie wody wirtualnej. Do produkcji fasoli największą objętość wirtualnej wody stwierdzono w Lorestanie (3651 dm3·kg–1), a najmniejszą w Markazi (2725 dm3·kg–1), gdzie stwierdzono także największą wydajność zużycia wody. Obliczono także, że – eksportując te produkty roślinne – wysłano za granicę 160,15 milionów m3 wody wirtualnej, skutkiem czego bilans wodny badanych upraw był ujemny.
Źródło:
Journal of Water and Land Development; 2017, 35; 275-280
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Two torymid species (Hymenoptera: Chalcidoidea, Torymidae) developing on Artemisia gall midges (Diptera: Cecidomyiidae)
Autorzy:
Lotfalizadeh, H.
Mohammadi-Khoramabadi, A.
Powiązania:
https://bibliotekanauki.pl/articles/65617.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Torymidae
parasitoid
Hymenoptera
Chalcidoidea
Artemisia
gall midge
Diptera
Cecidomyiidae
distribution
new record
Opis:
Two parasitoid wasps, Torymus artemisiae Mayr and Torymoides violaceus (Nikol’skaya), were reared on Artemisia herba-alba (Asteraceae) galles, in central Iran. Torymus artemisiae and T. violaceus were developed from the gall midges: Rhopalomyia navasi Tavares and R. hispanica Tavares, respectively. The occurrence of these two parasitic wasps in Iran, and their associations with R. navasi and R. hispanica, are new. Data on the wasps’ biological associations and geographical distribution are provided. The parasitoid compositions of the genus Rhopalomyia (Diptera: Cecidomyiidae) were also discussed.
Źródło:
Journal of Plant Protection Research; 2015, 55, 4
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Biocontrol potential of Trichoderma harzianum in controlling wilt disease of pistachio caused by Verticillium dahliae
Autorzy:
Fotoohiyan, Z.
Rezaee, S.
Bonjar, G.H.S.
Mohammadi, A.H.
Moradi, M.
Powiązania:
https://bibliotekanauki.pl/articles/65568.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
biological control
Trichoderma harzianum
controlling
wilt disease
antagonism
pistachio
orchard
Verticillium dahliae
Iran
Opis:
Verticillium wilt caused by Verticillium dahliae, is one of the most devastating diseases in pistachio orchards in the world including Iran. In search for an eff ective non-chemical strategy for the management of this disease, we evaluated the biocontrol potential of Trichoderma harzianum isolates obtained from the rhizosphere of healthy pistachio trees in diff erent locations of the Kerman province of Iran against V. dahliae under laboratory and greenhouse conditions. Dual culture tests in the laboratory were conducted in a completely randomized design using 72 T. harzianum isolates. Twenty isolates showed the highest in vitro antagonistic activity. Th e results indicated that all 20 isolates were capable of inhibiting the mycelial growth of V. dahliae signifi cantly. Among them, isolates Tr8 and Tr19 were the most eff ective by 88.89% and 85.12% inhibition, respectively. Extracted cell free metabolites of all eff ective isolates also inhibited the growth of V. dahliae in the culture medium signifi cantly. According to the results, isolates Tr4 and Tr6 inhibited fungal pathogen growth by 94.94% and 88.15% respectively, through production of non-volatile metabolites. In the evaluation of volatile metabolites, isolates Tr5 and Tr4 were the most eff ective by 26.27% and 24.49% growth inhibition, respectively. Based on the results of the in vitro experiments, the fi ve most eff ective isolates were selected for evaluation under greenhouse conditions for their biocontrol potential in controlling Verticillium wilt of pistachio. Results of the greenhouse, (in vivo) experiments were positive and indicated that the occurrence of wilt disease in plants treated with the antagonists alone or in combination with pathogenic fungus was lower than in plants inoculated with pathogen alone. Th e overall results of this study suggest that Trichoderma fungal antagonist may be an eff ective biocontrol agent for the control of Verticillium wilt of pistachio.
Źródło:
Journal of Plant Protection Research; 2017, 57, 2
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Identification of miRNAs and their potential targets in halophyte plant Thellungiella halophila
Autorzy:
Panahi, B.
Mohammadi, S.A.
Ebrahimie, E.
Powiązania:
https://bibliotekanauki.pl/articles/81192.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
microRNA
gene expression
halophytic plant
Thellungiella halophila
Expressed Sequence Tag programme
target protein
gene identification
Źródło:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology; 2013, 94, 3
0860-7796
Pojawia się w:
BioTechnologia. Journal of Biotechnology Computational Biology and Bionanotechnology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Numerical and experimental study of the mechanical response of aluminum foams under compressive loading using CT data
Autorzy:
Mohammadi Nasrabadi, A. A.
Hedayati, R.
Sadighi, M.
Powiązania:
https://bibliotekanauki.pl/articles/281633.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
metal foam
image processing
compression test
finite element method
CT scan
Opis:
Metal foams are relatively novel materials that due to excellent mechanical, thermal, and insulation properties have found wide usage in different engineering applications such as energy absorbers, bone substitute implants, sandwich structure cores, etc. In common numerical studies, the mechanical properties of foams are usually introduced to FE models by considering homogenized uniform properties in different parts of a foamy structure. However, in highly irregular foams, due to complex micro-geometry, considering a uniform mechanical property for all portions of the foam leads to inaccurate results. Modeling the micro-architecture of foams enables better following of the mechanisms acting in micro-scale which would lead to more accurate numerical predictions. In this study, static mechanical behavior of several closed-cell foam samples has been simulated and validated against experimental results. The samples were first imaged using a multi-slice CT-Scan device. Subsequently, experimental compression tests were carried out on the samples using a uniaxial compression testing machine. The CT data were then used for creating micro-scale 3D models of the samples. According to the darkness or brightness of the CT images, different densities were assigned to different parts of the micro-scale FE models of the foam samples. Depending on density of the material at a point, the elastic modulus was considered for it. Three different formulas were considered in different simulations for relating the local elastic modulus of the foam material to density of the foam material at that point. ANSYS implicit solver was used for the simulations. Finally, the results of the FE models based on the three formulas were compared to each other and to the experimental results to show the best formula for modeling the closed-cell foams.
Źródło:
Journal of Theoretical and Applied Mechanics; 2016, 54, 4; 1357-1368
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
The combined heat transfer of radiation and mixed convection analysis in a lid-driven trapezoidal cavity
Autorzy:
Mohammadi, M.
Gandjalikhan Nassab, S. A.
Powiązania:
https://bibliotekanauki.pl/articles/279609.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
mixed convection
radiation
lid-driven trapezoidal cavity
Opis:
In this paper, the effect of radiation heat transfer on mixed convection in a lid-driven trapezoidal cavity is studied numerically. The governing equations of mixed convection are solved based on the SIMPLE algorithm and the solution of the radiative transfer equation inside the participating medium is carried out using the discrete ordinates method, simultaneously. To study the heat transfer and flow characteristics, sensitivity analysis is carried out based on the two parameters including the optical thickness and radiation-conduction parameter. Several interesting results are obtained such as sweep behavior on the isotherms, streamlines and convective Nusselt number with optical thicknesses.
Źródło:
Journal of Theoretical and Applied Mechanics; 2015, 53, 3; 643-652
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of the multiple damages and temperature changes on the natural frequency
Autorzy:
Mohammadi Esfarjani, S.
Salehi, M.
Ghassemi, A.
Powiązania:
https://bibliotekanauki.pl/articles/279351.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
structural health monitoring
damage detection
vibration response
temperature
natural frequency
Opis:
Damage detection based on structural dynamic characteristics, such as natural frequencies and mode shapes, is an important area of research. Obtaining accurate structural dynamic characteristics is perhaps the most challenging aspect. In particular, changes in environmental temperature due to seasonal weather or radiation from sunshine leads to changes in the dynamic characteristics of structures. An important conclusion is that changes in the dynamic characteristics of a structure due to damage may be smaller than changes in the dynamic characteristics due to variations in temperature. Also, damage can affect the frequency response. This is the first study of evaluation of the effect of changes in temperature and multiple damages on natural frequency at the same time. In this paper, the simultaneous effect of the multiple defects and temperature on the natural frequencies of 6063 aluminum alloy beam are assessed numerically. ABAQUS finite element software is used for the numerical analysis. The present paper aims to evaluate the temperature effect and multiple damages on vibration responses. The variations in the frequency have been analysed in simulation by using an aluminum specimen and obtaining impedance signatures at temperatures ranging from −200◦C to 204◦C. The results show that an increase in temperature leads to a decrease in structural frequency, and that a decrease in temperature leads to an increase in structural frequency. The evaluation of the effect of multiple defects on natural frequency shows that when damages are created in the structure, there is a significant decrease in the natural frequency responses of the 6063 aluminum alloy beam. The results show that damage causes a decrease in the natural frequency of the structure. This study highlights the importance of applying simulation methods to the evaluation of the effect of changes in environmental temperature and multiple damages on the dynamic characteristics such as natural frequencies and mode shapes, especially at the same time.
Źródło:
Journal of Theoretical and Applied Mechanics; 2017, 55, 3; 813-822
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modulation index optimization for wavelength modulation spectroscopy
Autorzy:
Mohammadi, M. J.
Khorsandi, A.
Ghavami, S. S.
Powiązania:
https://bibliotekanauki.pl/articles/949416.pdf
Data publikacji:
2016
Wydawca:
Politechnika Wrocławska. Oficyna Wydawnicza Politechniki Wrocławskiej
Tematy:
wavelength modulation spectroscopy
NIR laser spectroscopy
molecular spectroscopy
Opis:
In this work, the second-harmonic component of wavelength modulation spectroscopy is simulated for R(22) CO2 absorption line to investigate the effect of gas temperature and pressure on the modulation index. We found that the optimum value of modulation index, that is 2.2, is not affected by temperature but gas pressure will change the optimized modulation index. Specifically, when the gas pressure decreased to lower pressures of less than 100 mbar, the modulation index is also decreased and tended exponentially to about two. Accordingly, the optimum value of modulation index is recalculated for a range of CO2 gas pressures to establish a nearly zero pressure deviation in the spectroscopy of very low pressure samples.
Źródło:
Optica Applicata; 2016, 46, 4; 639-650
0078-5466
1899-7015
Pojawia się w:
Optica Applicata
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A study of the local entropy generation rate in a porous media burner
Autorzy:
Mohammadi, I.
Esfahani, J. A.
Kim, K. C.
Powiązania:
https://bibliotekanauki.pl/articles/38597672.pdf
Data publikacji:
2020
Wydawca:
Instytut Podstawowych Problemów Techniki PAN
Tematy:
porous media burner
chemical kinetics
volumetric heat transfer
axisymmetric combustion
local entropy generation
excess air ratio
Opis:
In this paper, the work and performance of the premixed methane-air porous axisymmetrical burner have firstly been simulated numerically using the CFD tools. For this purpose the set of governing equations has been enriched by an additional energy equation in porous solid, and the chemical species transport has been extended onto the multi-step mechanism (GRI-2-11). This numerical model has been verified on the base of available benchmark experiments. Next, we have studied the local entropy generation problem taking into account not only classical contributions like viscous and turbulent dissipation but also, the porous combustion of gases. The results showed that the greatest portion of entropy generation in the porous medium burner is related to chemical reactions, followed by heat transfer, mass diffusion (mixing) and friction (viscous dissipation), respectively. According to the results, as the excess air ratio increases, the local entropy generation rate due to heat transfer and friction increases and the local entropy generation rate due to chemical reactions is decreased. Also, by increasing the volumetric heat transfer coefficient, the local entropy generation rate due to heat transfer decreases and the local entropy generation rate due to friction and chemical reactions increases. Also, the local entropy generation rate due to mixing does not show a significant change with the changing excess air ratio and volumetric heat transfer coefficient.
Źródło:
Archives of Mechanics; 2020, 72, 3; 257-279
0373-2029
Pojawia się w:
Archives of Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of laser priming on canola yield and its components under salt stress
Autorzy:
Mohammadi, S.K.
Shekari, F.
Fotovat, R.
Darudi, A.
Powiązania:
https://bibliotekanauki.pl/articles/26380.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
laser irradiation
canola
yield
yield component
salt stress
salinity
seed
correlation coefficient
Opis:
The effect of laser priming at different irradiation times on canola yield and its components under saline conditions were investigated. The results showed that laser priming had a positive effect on yield and its components and caused yield increase under saline conditions. Increase in salt levels had a negative and significant effect on seed yield, number of seeds per pod, number of pod per plant, pod length and plant height. The results showed that 45-min laser priming had the strongest effect on yield and yield components and reduced significantly the adverse effects of salinity.By contrast, laser radiation applied for 60 and 75 min, resulted in a dramatic decrease in yield and its components. Correlation coefficients between the attributes showed that canola yield had a positive and significant correlation with plant height, number of seeds, pod per main branch and lateral branches, length of pod and number of lateral branches. Effects of laser and salinity were significant on lateral branch pod length but not on main branch pods.
Źródło:
International Agrophysics; 2012, 26, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterization and concentration studies of Jalal Abad iron mine
Charakterystyka i badania koncentracji w kopalni rud żelaza Jalal Abad
Autorzy:
Hashemi, S. A.
Rezai, B.
Tavakoli Mohammadi, M. R.
Javanshir, S.
Powiązania:
https://bibliotekanauki.pl/articles/219259.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kopalnia rud żelaza Jalal Abad
charakterystyka
rurka Davisa
separacja magnetyczna
Jalal Abad iron mine
characterization
Davis tube
magnetic separation
Opis:
Characterization and determination of liberation degree are the first stages of ore dressing. Block 4 of Jalal Abad mine, Kerman province, Iran, has three kinds of iron ores; D1, D2 and D3, with different grades. In this research, chemical analysis, mineralogy, liberation degree and magnetic enrichment studies were done by XRF, XRD, microscopic sections and Davis tube, respectively. The results indicated that D1, D2 and D3 had average iron grades of 58, 52 and 38%, respectively. The minerals of Magnetite, Hematite, Dolomite, Calcite and Quartz were distinguished. Average liberation degree was estimated about 500 μm by Microscopic studies. The results of magnetic tests showed that iron grade of D1, D2 and D3 concentrates increased to 70.46, 63.98 and 45.37%, respectively. The optimization of blending was investigated for production of accumulated concentrate with desirable iron grade (68%) using MATLAB software.
Charakterystyka i określenie stopnia uwalniania to pierwsze etapy w procesie oczyszczania rud. W bloku 4 kopalni rud żelaza Jalal Abad w prowincji Kerman w Iranie, znajdują się trzy rodzaje złóż rud żelaza: D1, D2, D3, różnej klasy. W pracy tej przedstawiono wyniki analizy chemicznej, mineralogicznej, stopnia uwalniania oraz separacji magnetycznej wykonanych przy zastosowaniu metod XRF, dyfrakcji (XRD) oraz metod mikroskopowych i rurki Davisa. Wyniki analiz wskazują, że złoża D1, D2, D3 to złoża w klasie o zawartości odpowiednio 58, 52 i 38%. W próbkach określono zawartość magnetytu, hematytu, dolomitu, kalcytu oraz kwarcu. Średni poziom uwalniania określony przy pomocy metod mikroskopowych oszacowano na 500 μm. Wyniki badań magnetycznych wskazują, że zawartości żelaza w koncentracie D1,D2 i D3 wzrosły odpowiednio do 70.46, 63.98 i 45.37%. Przeprowadzono optymalizację mieszania koncentratów w celu produkcji końcowego koncentratu o pożądanym poziomie zawartości żelaza (68%) przy zastosowaniu oprogramowania MATLAB.
Źródło:
Archives of Mining Sciences; 2013, 58, 3; 729-745
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effects of Physical and Personal Risk Factors on Sick Leave Due to Musculoskeletal Disorders
Autorzy:
Motamedzade, M.
Faghih, M. A.
Golmohammadi, R.
Faradmal, J.
Mohammadi, H.
Powiązania:
https://bibliotekanauki.pl/articles/90566.pdf
Data publikacji:
2013
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
sick leave
physical risk factors
musculoskeletal disorders
assembly workers
car manufacturing
czynniki ryzyka
zwolnienie lekarskie
zaburzenia układu mięśniowo-szkieletowego
Opis:
The purpose of this study was to investigate the effects of physical and personal risk factors on sick leave due to musculoskeletal disorders in an Iranian car company. In this cross-sectional study, 234 workers participated and all of them had sick leave due to musculoskeletal disorders in the past year. A physical risk factor checklist and personal information questionnaire were used as data-gathering tools. There was no significant relationship between physical risk factors and sick leave (p > .05). Cigarette smoking (p = .045), body mass index >30 (p = .046) and age (p = .044) showed a significant relationship with sick leave. Workers with lumbar deviation of 20°–60° (OR 1.10) and >60° (OR 1.11) were at greater risk. The ratios for workers with repetitive work (OR 1.30) and workers with force exertion (OR 1.36) were greater than for other workers. Taking preventive actions to improve the ergonomic working conditions of assembly workers and their lifestyle seems crucial.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2013, 19, 4; 513-521
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
Dostawca treści:
Biblioteka Nauki
Artykuł

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