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Tytuł:
Identification and characterization of Pseudomonas syringae pv. syringae strains from various plants and geographical regions
Autorzy:
Khezri, M.
Mohammadi, M.
Powiązania:
https://bibliotekanauki.pl/articles/65669.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
identification
Pseudomonas syringae pv.syringae
plant
phenotype
polymerase chain reaction
protein profile
plasmid
syringomycin
geographic region
Opis:
Pseudomonas syringae pv. syringae (Pss) constitutes a diverse group of bacterial strains that cause canker of stone fruits, blight of cereals and red streak of sugarcane. The purpose of this study was to determine how diverse Iranian strains of Pss are when they come from different hosts. We compared a total of 32 Pss strains isolated from stone fruits, barley, wheat and sugarcane from different geographical regions of Iran based on their phenotypic and molecular properties. Strains showed some variation regarding carbon and nitrogen utilization. Pss strains were similar in their protein banding patterns. Additional bands were found in sugarcane strains. Most strains showed one indigenous plasmid DNA and a few had two and some none. The genes of syrB and syrD encoding syringomycin synthesis and secretion, respectively, were amplified using specific primers in polymerase chain reaction. Syringomycin, producing strains amplified two DNA fragments of 752 and 446 bp representing syrB and syrD genes, respectively. Primer specificity was shown for Pss using various genera. Based on the results of this study, it is suggested that Pss strains from different hosts and geographical regions show diversity in phenotypic and molecular characters. It is thought that phenotypic variation is due to adaptation to specific hosts and niches for survival and pathogenicity.
Źródło:
Journal of Plant Protection Research; 2018, 58, 4
1427-4345
Pojawia się w:
Journal of Plant Protection Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Improved Synthesis of Glycidyl Nitrate in the Presence of 5-Aminotetrazolium Nitrate: a New Method Optimised Using the Taguchi Method
Autorzy:
Bayat, Y.
Mohammadi, M. M.
Powiązania:
https://bibliotekanauki.pl/articles/358882.pdf
Data publikacji:
2016
Wydawca:
Sieć Badawcza Łukasiewicz - Instytut Przemysłu Organicznego
Tematy:
glycidyl nitrate
5-aminotetrazolium nitrate
chloro-epoxy-propane
Taguchi method
Opis:
This paper describes a method for increasing the yield of glycidyl nitrate from chloro-epoxypropane and dilute nitric acid, in the presence of 5-aminotetrazolium nitrate. The presence of 5-aminotetrazolium nitrate as catalyst and co-nitrating agent, enabled glycidyl nitrate to be produced smoothly and in excellent yield under mild condition. The optimal reaction conditions were obtained by the Taguchi method, increasing the yield from 66 to 81%. The product was characterized by FTIR and 1H NMR spectroscopy.
Źródło:
Central European Journal of Energetic Materials; 2016, 13, 3; 579-591
1733-7178
Pojawia się w:
Central European Journal of Energetic Materials
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:
Performance evaluation of bucket based excavating, loading and transport (BELT) equipment – an OEE approach
Ocena działania systemu złożonego z urządzeń do urabiania, załadunku oraz transportu – podejście oparte o całościową ocenę efektywności
Autorzy:
Mohammadi, M.
Rai, P.
Gupta, S.
Powiązania:
https://bibliotekanauki.pl/articles/218889.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
całościowa ocena efektywności
pomiar wydajności
wykorzystanie sprzętu
tempo prac
ładowność
sprzęt górniczy
OEE
performance measurement
availability
utilization
speed factor
bucket capacity
mining equipment
Opis:
Overall Equipment Effectiveness (OEE) has been used since last over two decades as a measure of performance in manufacturing industries. Unfortunately, enough, application of OEE in mining and excavation industry has not been duly adopted. In this paper an effort has been made to identify the OEE for performance evaluation of Bucket based Excavating, Loading and Transport (BELT) equipment. The conceptual model of OEE, as used in the manufacturing industries, has been revised to adapt to the BELT equipment. The revised and adapted model considered the operational time, speed and bucket capacity utilization losses as the key OEE components for evaluating the performance of BELT equipment. To illustrate the efficacy of the devised model on real-time basis, a case study was undertaken on the biggest single bucket excavating equipment – the dragline, in a large surface coal mine. One-year data was collected in order to evaluate the proposed OEE model.
Podejście oparte o całościową ocenę efektywności używane jest od ponad dwóch dekad w analizach skuteczności działania urządzeń w przemyśle wytwórczym. Niestety podejście to nie zostało szeroko przyjęte w przemyśle górniczym. W pracy tej podjęto próbę dokonania całościowej oceny efektywności pracy układu złożonego ze sprzętu do urabiania, załadunku (koparki) oraz transportu. Model koncepcyjny podejścia całościowej oceny stosowany dotychczas w przemyśle wytwórczym został zaadaptowany by uwzględniać specyfikę systemów urabiania, ładowania i transportu. Odpowiednio zmodyfikowany model uwzględnia czas pracy układu, tempo pracy, spadek ładowności koparki i spowodowane w ten sposób straty, umożliwiając dokonanie całościowej oceny wydajności pracy systemu. Poprawność opracowanego modelu działającego w czasie rzeczywistym zbadano na przykładzie systemu do urabiania, załadunku i transportu wykorzystywanego w dużej kopalni odkrywkowej węgla. Do oceny poprawności modelu wykorzystano zebrane dane obejmujące cały rok pracy urządzeń.
Źródło:
Archives of Mining Sciences; 2017, 62, 1; 105-120
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Some physiological responses of wheat and bean to soil salinity at low matric suctions
Autorzy:
Khatar, M.
Mohammadi, M.H.
Shekari, F.
Powiązania:
https://bibliotekanauki.pl/articles/24475.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Opis:
The effect of soil matric suction (2-33 kPa) and salinity (soil solution electrical conductivity 0.7-8 dS m-1 for bean and 2-20 dS m-1 for wheat) on some physiological characteristics of bean and wheat in a clay loam soil under greenhouse condition was investigated. The results showed that the leaf chlorophyll content index and potassium concentration decrease under salinity stress and increase with matric suction from 2 to 33 kPa suction for both plants. The wheat chlorophyll content index declines during the stress spell but bean chlorophyll content index remains nearly constant. The lowest values of the content of soluble sugars and the highest values of leaf proline content are observed at 2 kPa matric suction (highest aeration stress) for bean and wheat. As matric suction increases from 2 to 6 kPa, the soluble sugars increases and proline content decreases significantly and then soluble sugars decreases and proline content increases until 10 kPa suction, and the soluble sugars remains nearly constant at the higher matric suctions for both plants. While the electrical conductivity effect on the soluble sugars is not significant, the values of proline content for both crop increase significantly with electrical conductivity. It was shown that the aeration stress can result in more considerable and rapid physiological responses, in comparison with salinity stress. There is a strong correlation between wheat and bean chlorophyll content index and potassium concentration under salinity and aeration stresses.
Źródło:
International Agrophysics; 2017, 31, 1
0236-8722
Pojawia się w:
International Agrophysics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Study on Bacillus isolated from intestine of Persian sturgeon (Acipenser persicus) comparing with commercial probiotics
Autorzy:
Tabari, M.
Tabari, K.
Karimzadegan, H.
Mohammadi, M.
Powiązania:
https://bibliotekanauki.pl/articles/11072.pdf
Data publikacji:
2016
Wydawca:
Przedsiębiorstwo Wydawnictw Naukowych Darwin / Scientific Publishing House DARWIN
Źródło:
International Letters of Natural Sciences; 2016, 60
2300-9675
Pojawia się w:
International Letters of Natural Sciences
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:
An efficient analysis of steady-state heat conduction involving curved line/surface heat sources in two/three-dimensional isotropic media
Autorzy:
Mohammadi, M.
Hematiyan, M. R.
Shiah, Y. C.
Powiązania:
https://bibliotekanauki.pl/articles/279914.pdf
Data publikacji:
2018
Wydawca:
Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
Tematy:
heat conduction
concentrated heat source
curved heat source
mesh-free method
Opis:
In this paper, a new formulation based on the method of fundamental solutions for two/three- -dimensional steady-state heat conduction problems involving internal curved line/surface heat sources is presented. Arbitrary shapes and non-uniform intensities of the curved heat sources can be modeled by an assemblage of several parts with quadratic variations. The presented mesh-free modeling does not require any internal points as in domain methods. Four numerical examples are studied to verify the validity and efficiency of the proposed method. Our analyses have shown that the presented mesh-free formulation is very efficient in comparison with conventional boundary or domain solution techniques.
Źródło:
Journal of Theoretical and Applied Mechanics; 2018, 56, 4; 1123-1137
1429-2955
Pojawia się w:
Journal of Theoretical and Applied Mechanics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Evaluation of canola chlorophyll index and leaf nitrogen under wide range of soil moisture
Autorzy:
Meskini-Vishkaee, F.
Mohammadi, M.H.
Neyshabouri, M.R.
Shekari, F.
Powiązania:
https://bibliotekanauki.pl/articles/25557.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Instytut Agrofizyki PAN
Tematy:
canola
chlorophyll level
leaf
nitrogen
soil moisture
plant stress
environmental stress
Opis:
The paper presents a study on the effect of soil matric suction on the variation of leaf chlorophyll index and nitrogen concentration of canola. Results showed that chlorophyll index increases exponentially with soil matric suction, especially at the late season of canola growing time. At moderate matric suction (200 and 300 kPa soil suction heads), chlorophyll index remains nearly constant, but in drier soil (matric suction >300 kPa),chlorophyll index increases gradually with time. Despite the va-riation of the total leaf nitrogen with the soil matric suction, it is similar to the variation of the chlorophyll index, but the results showed that the chlorophyll index – nitrogen concentration curve has a de-marcated bi-modal shape. We suggest that 2.7% of nitrogen and 69.8 of the chlorophyll index value represent the upper limit of the chlorophyll meter reliability for estimation of canola nitrogen under a wide range of soil moisture levels. These results confirm that the chlorophyll meter can be used as an effective tool for rapid and non-destructive estimation of the relative chlorophyll and nitrogen content in canola leaves at a wide range of soil moisture content, except for nearly wilting coefficient or extremely high drought stress.
Źródło:
International Agrophysics; 2015, 29, 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:
Parametric estimation of water retention using mGMDH method and principal component analysis
Autorzy:
Neyshaburi, M.R.
Bayat, H.
Rastgou, M.
Mohammadi, K.
Gregory, A.S.
Nariman-Zadeh, N.
Powiązania:
https://bibliotekanauki.pl/articles/905465.pdf
Data publikacji:
2016
Wydawca:
Uniwersytet Marii Curie-Skłodowskiej. Wydawnictwo Uniwersytetu Marii Curie-Skłodowskiej
Opis:
Performing a primary analysis, such as principal component analysis (PCA) may increase accuracy and reliability of developed pedotransfer functions (PTFs). This study focuses on the usefulness of the soil penetration resistance (PR) and principal components (PCs) as new inputs along with the others to develop the PTFs for estimating the soil water retention curve (SWRC) using a multi-objective group method of data handling (mGMDH). The Brooks and Corey (1964) SWRC model was used to give a description of the water retention curves and its parameters were determined from experimental SWRC data. To select eight PCs, PCA was applied to all measured or calculated variables. Penetration resistance, organic matter (OM), aggregates mean weight diameter (MWD), saturated hydraulic conductivity (Ks), macro porosity (Mp), micro porosity (Mip) and eight selected PCs were used as predictors to estimate the Brooks and Corey model parameters by mGMDH. Using PR or OM, Ks and MWD, improved the estimation of SWRC in some cases. Using the predicted PR can be useful in the estimation of SWRC. Using either the MP and Mip or the eight PCs significantly improved the PTFs accuracy and reliability. It would be very useful to apply PCA on the original variables as a primary analysis to develop parametric PTFs.
Źródło:
Polish Journal of Soil Science; 2016, 49, 1
0079-2985
Pojawia się w:
Polish Journal of Soil Science
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of Fecal Egg Counts and ELISA for the diagnosis of Dicrocoelium Dendriticum infection
Autorzy:
Naeemipour1, M.
Hashemitabar, Ch.R.
Dastjerdi, K.
Jamshidian Mojaver, M.
Mohammadi, H.R.
Powiązania:
https://bibliotekanauki.pl/articles/32321.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Opis:
From economical point of view, Dicrocoelium Dendriticum (D. dendriticum) causes a lot of damages to the livestock industry annually. So, the rapid diagnosis of infection is very important. The diagnosis is based on egg per count of feces (EPG) test because detection according to clinical symptoms is difficult. Since EPG is not accurate and sensitive, the serological methods become important for the diagnosis of this parasite as they are more accurate in comparison to EPG test and they are able to diagnose infection in a short time. In this study, somatic and Excretory-secretory antigens (EsAg) were isolated. The ELISA test was set up according to positive and negative sera and the results which were obtained compared to those obtained by the EPG test. The prevalence of infection in 550 samples by ELISA and EPG methods were 56% and 7% respectively, which shows the significant difference between these methods in examining the rate of infection. Based on the results, the specificity and sensitivity in ELISA test were 95% and 94%, respectively. The results showed that the ELISA is a more reliable test in comparison to EPG test for the rapid diagnosis of D. dendriticum infection.
Źródło:
Polish Journal of Veterinary Sciences; 2016, 19, 3
1505-1773
Pojawia się w:
Polish Journal of Veterinary Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Positioning and control of nozzles and water particles in decorative water curtain and water screens
Autorzy:
Hajiheydari, M.
Mohammadi, S.
Powiązania:
https://bibliotekanauki.pl/articles/384568.pdf
Data publikacji:
2012
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
water nozzle
curtain
decorative
simulation
OpenGL
Opis:
LED and LCD displays, laser show devices and animators, musical fountains, water curtains and artificial waterfalls, etc., are decorative instruments. Some of them were developed for intelligent pouring of water droplets as particles in a space (particle screen). They have nozzles in the line that generates pattern with programmed on or off of its valves. This article introduces an improvement of water curtain (waving pouring water) and water screen (stenciled water screen by use of on-off valves), and combines them together.
Źródło:
Journal of Automation Mobile Robotics and Intelligent Systems; 2012, 6, 4; 33-35
1897-8649
2080-2145
Pojawia się w:
Journal of Automation Mobile Robotics and Intelligent Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of plant growth adjuvants on direct regeneration of Mohammadi flower (Rosa damascena Mill.) using thin cell layering technique
Autorzy:
Mirshahi, H.
Mahdinezhad, N.
Soloki, M.
Samiei, L.
Powiązania:
https://bibliotekanauki.pl/articles/12715591.pdf
Data publikacji:
2020
Wydawca:
Uniwersytet Przyrodniczy w Lublinie. Wydawnictwo Uniwersytetu Przyrodniczego w Lublinie
Opis:
Regeneration is one of the most important methods in the massive proliferation of ornamental plants through micropropagation and genetic modification. Thin cell layering (TCL) technique, is a new introduction of micropropagation efficiency in producing optimized mass scale of crops. The horizontally placed TCL explants (tTCLs) was examined in Van der Salm (VS) basal medium in combination with different plant adjuvants (proline, glutamic acid, casein hydrolysate) to investigate their effect on callus induction and shoot regeneration of the explants. In order to produce healthy propagules of Rosa damascena Mill. on a large scale, a new cost-effective method of tissue culture has been established. The results indicated the positive effect of proline (0.5 gr/l) and glutamic acid (300 mg/l) in both callus induction and regeneration stage. Also, in rooting phase, different concentrations of IBA and NAA (0, 0.3, 0.6, 0.9 mg/l) in basal ½ Van der Salm (VS) medium were tested. It was observed that the best results were related to 0.3 mg/l IBA + 0.3 mg/l NAA in ½ Van der Salm (VS) medium.
Źródło:
Acta Scientiarum Polonorum. Hortorum Cultus; 2020, 19, 3; 167-177
1644-0692
Pojawia się w:
Acta Scientiarum Polonorum. Hortorum Cultus
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:
Manual Material Handling Assessment Among Workers of Iranian Casting Workshops
Autorzy:
Mohammadi, H.
Motamedzade, M.
Faghih, M. A.
Bayat, H.
Mohraz, M. H.
Musavi, S.
Powiązania:
https://bibliotekanauki.pl/articles/89709.pdf
Data publikacji:
2013
Wydawca:
Centralny Instytut Ochrony Pracy
Tematy:
musculoskeletal disorders
manual material handling
casting workers
Snook tables
warsztaty odlewnicze
zaburzenia układu mięśniowo-szkieletowego
magazynowanie
pracownicy odlewni
Opis:
Manual material handling (MMH) tasks can be found in most workplaces and they may constitute a risk factor for work-related musculoskeletal disorders (WMSDs). This study was conducted to determine the prevalence of WMSDs and to compare MMH loads with the acceptable weight and force limits among Iranian casting workers. Data were collected from 50 workers of casting workshops who performed MMH tasks. The Nordic musculoskeletal disorders questionnaire and the Snook tables were used as tools for data collection. Hand/wrist symptoms were the most prevalent problems among the workers (84%). The results of the Snook tables showed that the loads in lifting (84%), lowering (86%), carrying (66%), pushing with initial (43%) and sustained force (59%), and pulling tasks with initial (48%) and sustained force (93%) exceeded recommended limits. WMSDs occurred in high rates among the workers and, thus, ergonomics interventions should focus on decreasing WMSDs and redesigning MMH tasks.
Źródło:
International Journal of Occupational Safety and Ergonomics; 2013, 19, 4; 675-681
1080-3548
Pojawia się w:
International Journal of Occupational Safety and Ergonomics
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
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:
A simulated annealing based optimization algorithm for automatic variogram model fitting
Symulacja algorytmu optymalizacyjnego procesu odprężania dla automatycznego dopasowania modelu wariogramu
Autorzy:
Soltani-Mohammadi, S.
Safa, M.
Powiązania:
https://bibliotekanauki.pl/articles/219828.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
automatyczne dopasowanie wariogramu
geostatystyka
optymalizacja
symulacje procesu odprężania
automatic variogram fitting
geostatistics
optimization
simulated annealing
Opis:
Fitting a theoretical model to an experimental variogram is an important issue in geostatistical studies because if the variogram model parameters are tainted with uncertainty, the latter will spread in the results of estimations and simulations. Although the most popular fitting method is fitting by eye, in some cases use is made of the automatic fitting method on the basis of putting together the geostatistical principles and optimization techniques to: 1) provide a basic model to improve fitting by eye, 2) fit a model to a large number of experimental variograms in a short time, and 3) incorporate the variogram related uncertainty in the model fitting. Effort has been made in this paper to improve the quality of the fitted model by improving the popular objective function (weighted least squares) in the automatic fitting. Also, since the variogram model function (£) and number of structures (m) too affect the model quality, a program has been provided in the MATLAB software that can present optimum nested variogram models using the simulated annealing method. Finally, to select the most desirable model from among the single/multi-structured fitted models, use has been made of the cross-validation method, and the best model has been introduced to the user as the output. In order to check the capability of the proposed objective function and the procedure, 3 case studies have been presented.
Dopasowanie modelu teoretycznego do eksperymentalnego wariogramu jest kluczowym zagadnieniem w badaniach geostatystycznych ponieważ jeśli parametry modelu wariogramu obarczone są niepewnością, to otrzymamy znaczny rozrzut wyników obliczeń i symulacji. Pomimo, że najpopularniejszą metoda dopasowania jest dopasowanie ‘na oko’, w niektórych przypadkach wykorzystuje się automatyczne metody dopasowania modelu oparte na zasadach geostatystyki i optymalizacji w celu: 1) dostarczenia podstawowego modelu do dopasowania ‘na oko’; 2) dopasowania modelu do większej ilości eksperymentalnych wariogramów w krótkim okresie czasu; 3) uwzględnienia niepewności związanej z wariogramem w dopasowaniu modelu. W pracy podjęto próbę poprawy jakości dopasowania modelu poprzez wprowadzenie zmodyfikowanej popularnej funkcji celu (ważone najmniejsze kwadraty) do au- tomatycznego dopasowania. Ponadto, ponieważ funkcja modelu wariogramu (L) i ilość struktur (m) ma także wpływ na jakość modelu, opracowano program w środowisku MATLAB który podaje optymalne modele wariogramu w oparciu o metodę symulacji odprężania. W części końcowej wybrano najkorzystniejszy model spośród modeli dopasowania z wykorzystaniem metody walidacji krzyżowej i najlepszy model przedstawiany jest użytkownikowi. W celu zbadania możliwości stosowania proponowanej funkcji celu i przedstawionej procedury, zaprezentowano trzy studia przypadku.
Źródło:
Archives of Mining Sciences; 2016, 61, 3; 635-649
0860-7001
Pojawia się w:
Archives of Mining Sciences
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:
Designing a simple radiometric system to predict void fraction percentage independent of flow pattern using radial basis function
Autorzy:
Roshani, G. H.
Nazemi, E.
Shama, F.
Imani, M. A.
Mohammadi, S.
Powiązania:
https://bibliotekanauki.pl/articles/221419.pdf
Data publikacji:
2018
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
two-phase flow
gamma-ray attenuation
scintillation detector
void fraction
artificial neural network
Opis:
The void fraction is one of the most important parameters characterizing a multiphase flow. The prediction of the performance of any system operating with more than single phase relies on our knowledge and ability to measure the void fraction. In this work, a validated simulation study was performed in order to predict the void fraction independent of the flow pattern in gas-liquid two-phase flows using a gamma ray 60Co source and just one scintillation detector with the help of an artificial neural network (ANN) model of radial basis function (RBF). Three used inputs of ANN include a registered count under Compton continuum and counts under full energy peaks of 1173 and 1333 keV. The output is a void fraction percentage. Applying this methodology, the percentage of void fraction independent of the flow pattern of a gas-liquid two-phase flow was estimated with a mean relative error less than 1.17%. Although the error obtained in this study is almost close to those obtained in other similar works, only one detector was used, while in the previous studies at least two detectors were employed. Advantages of using fewer detectors are: cost reduction and system simplification.
Źródło:
Metrology and Measurement Systems; 2018, 25, 2; 347-358
0860-8229
Pojawia się w:
Metrology and Measurement Systems
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:
Optimal site selection for heap leaching structures by the analytic hierarchy process (case study: Taft heap leaching structure, Iran)
Optymalny wybór lokalizacji struktur ługowania hałdy za pomocą analizy hierarchicznej (studium przypadku: hałda (składowisko) Taft, Iran)
Autorzy:
Soltani-Mohammadi, S.
Amini, M.
Powiązania:
https://bibliotekanauki.pl/articles/216766.pdf
Data publikacji:
2013
Wydawca:
Polska Akademia Nauk. Instytut Gospodarki Surowcami Mineralnymi i Energią PAN
Tematy:
wymywanie hałdy
kryterium oceny
optymalne miejsce
AHP
heap leaching
assessment criterion
optimum site
Opis:
Lokalizacja składowiska odpadów z procesów hydrometalurgicznych ma bardzo duży wpływ na koszty jego budowy i ryzyka związane ze środowiskiem. Wybór miejsc ługowania hałdy zależy od różnych parametrów technicznych (topograficznych, hydrologicznych, hydrogeologicznych i innych) oraz od uwarunkowań ekonomicznych i ekologicznych. W wielu przypadkach wybór optymalnych miejsc ługowania hałdy dokonywany jest z uwzględnieniem szeregu kryteriów za pomocą metod ELECTRE, TOPSIS i AHP. W artykule, w pierwszej kolejności określono kryteria do lokalizacji miejsc ługowania (o charakterze technicznym, finansowym i środowiskowym) i zbadano ich wpływ na wybór lokalizacji miejsc ługowania. Następnie korzystając z metody AHP problem decyzyjny rozpatrywano na trzech poziomach, wykorzystując oprogramowanie „Expert Choice”. W celu sprawdzenia metody wybrano hałdę w okolicy Taft, prowincji Yazd w Iranie. Analiza wrażliwości, która bada reakcję całego przedsięwzięcia została przeprowadzona dla głównych kryteriów technicznych, ekonomicznych i środowiskowych.
In hydrometallurgical projects, the heap location greatly affects construction costs and environmental hazards. Heap leach pad site selection depends on different technical parameters (topographical, borrow sources, hydrological, hydro-geological, etc.) and other financial and environmental factors. In many situations, there are some proposed sites with different parameters, and it is necessary that the optimum heap leach pad site be selected with the help of multi-criteria decision making methods such as ELECTRE, TOPSIS, and AHP. In this paper, we have first studied the heap leach pad site selection criteria (technical, financial, and environmental) and their effects on the selection of the location of the heap leaching structures. Then, using the AHP method, the decision making problem was hierarchically structured at three levels. For analysis, use was made of the “Expert Choice” software. To check the practicality of the method, an appropriate site for the construction of the leaching heap was selected at the Taft area, Yazd province, Iran. Finally, sensitivity analysis exploring the overall priority of alternatives to changes in the relative synthesis value of each criterion was carried out for the main technical, economic, and environmental criteria.
Źródło:
Gospodarka Surowcami Mineralnymi; 2013, 29, 1; 109-125
0860-0953
Pojawia się w:
Gospodarka Surowcami Mineralnymi
Dostawca treści:
Biblioteka Nauki
Artykuł
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