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Showing 8 results for Shakarami


Volume 6, Issue 3 (9-2017)
Abstract

Aphis gossypii Glover is one of the major pests of cucumber in Iran. The effects of different concentrations of nitrogen (N1 = 0, N2 = 30, N3 = 60, N4 = 90 and N5 = 120 kg/ha), phosphorus (P1 = 0, P2 = 15 and P3 = 22.5 kg/ha) and silicon (Si1 = 0, Si2 = 100 and Si3 = 200 kg/ha) on life table parameters of apterous morph of A. gossypii were studied. This study was conducted as factorial experiment based on RCD with nine replications in a growth chamber at temperature of 25 ± 3 °C, 60 ± 5% relative humidity (RH) and a photoperiod of 16: 8 h (light: dark). The experiments were carried out using clip-cages that were fixed on leaves of cucumber growing in pots. According to the results, total fecundity of A. gossypii significantly was different among treatments and it was the highest on N1P2Si2 (64.33 offspring) and the lowest on N3P2Si1 (22.67 offspring). The lowest and the highest values of R0 were observed on N3P2Si1and N4P2Si2, respectively. The shortest mean generation time (T) was found on N4P1Si3 and the longest was on N5P3Si1. Furthermore, the lowest and the highest values of r were obtained on N5P3Si2 (0.27 day-1) and N5P1Si1 (0.41 day-1). Our results showed that in simultaneous application, the phosphorus had a more impact on life history and performance of cotton aphid.

Volume 7, Issue 2 (7-2018)
Abstract

In recent years, different formulations such as nanoemulsions have been widely used for the target delivery, and enhanced biological functions of pesticides combinations. In this study, contact toxicity of Mentha longifolia L. essential oil compared with its nanoemulsion on Ephestia kuehniella Zeller has been investigated. The experiments were conducted and executed at 27 ± 1 °C, and 75 ± 5% relative humidity under dark conditions. Chemical composition of this plant extract was also studied. The main constituents were pulegone (28.84%), 1,8-cineol (19.6%), p-menthan-3-one-cis (8.2%), β-pinene (6.46%) and p-menthan-3-one-trans (5.86%). Results indicated that the mortality rate of 5th instar larva of E. kuehniella increased with rising concentrations (10000-40000ppm) for oil and (8000-20000 ppm) for nanoemulsion, respectively. The essential oil LC50 was 21352ppm, while this value for nanoemulsion was 14068ppm. According to the results, nanoemulsion was more effective than essential oil. M. longifolia oil had lower durability and the 50% persistent time (PT50) was 2.39 day compared to the nanoemulsion (PT50 = 17.13 day) in the highest concentration of essential oil. The nanoparticle size was 14-36 nanometers (nm) when the transmission electron microscope (TEM) was applied. The surface morphology of nanoemulsion was also studied by TEM. The average size of the particles was estimated 234nm by using laser light scattering apparatus. The overall results of this study show that by using nanoemulsion formulation, the effect of essential oil contact toxicity and its durability increases. Hence, the nanoemulsion slow-release formulation may represent a new category of biopesticides and this should be considered in the integrated pest management program.

Volume 10, Issue 1 (10-2021)
Abstract

 Gut bacterial symbionts have an essential role in the nutrition and fitness of xylophagous insects. These bacteria produce several enzymes like cellulase and laccase which are important in industrial applications. In this study, laccase-producing bacteria were isolated and identified from the gut of the wood borer leopard moth. Four novel laccase positive strains were isolated using guaiacol-containing agar plates. Among the strains of dc4f, le2f, lc2, and lb8, the strain le2f displayed high laccase activity of 0.059 U ml-1 toward syringaldazine as a typical laccase substrate. The isolates were identified based on biochemical tests and 16S rRNA gene sequencing analyses. Nucleotide BLAST analyses of 16S rRNA gene sequence exhibited that the strains of dc4f, lb8, lc2, and le2f, had the most similarity (with more than 98% identity) with Enterobacter sp. strain W-6 16S (ACCN: MK505390), Serratia liquefaciens strain N112 (ACCN: MK629784), Brevibacterium sp. strain 773 (ACCN: MH777897) and Staphylococcus sciuri strain KSI 708 (ACCN: KC113150), respectively. Overall, the current study is the first research on alkaliphilic bacterial strains from the gut of leopard moth with laccase activity.


Volume 10, Issue 4 (11-2021)
Abstract

Peach twig borer (PTB), Anarsia lineatella Zeller, is the most critical pest of peach and other stone fruits in different parts of the world. The objectives of this study were to determine adults’ seasonal activity and damage caused by PTB on different peach cultivars (Zafarani, Kardi, Elberta, Red top, and GF677) under natural conditions. The seasonal flight of the adults using pheromone traps indicated that PTB completed three generations per year in peach orchards, Saman, Chaharmahal va Bakhtiari, Iran. The accumulated degree-days throughout the pest activity from April to October were 1916 and 1803 DD in 2014 and 2015, respectively. The ratio of twig and fruit infestation and the number of larval galleries/fruit were studied among the cultivars using a completely randomized block design in four replicates. According to the results, the highest ratio of twig infestation was observed on GF677 followed by Zafarani, whereas the lowest on Elberta followed by Kardi cultivar. The longest larval galleries (68.44 ± 1.28 and 56.80 ± 1.24 mm) was observed on GF677, whereas the shortest on Elberta cultivar (39.20 ± 1.64 and 32.40 ± 1.36 mm in 2014 and 2015, respectively). The highest ratio of fruit damage and larval galleries/fruit were observed on Kardi, whereas the lowest was on Red top cultivar. According to the results, the cultivars with hard tissues of twigs and early maturing fruits significantly reduced PTB damage and are recommended for pest management in the infested regions.
 

Volume 17, Issue 109 (March 2021)
Abstract

This study was conducted to determine the effects of flower and leaf extract of Humulus lupulus plant on the shelf life and quality attributes of strawberry fruits. Different treatments were applied in this research including: flower and leaf ethanolic extract of Humulus lupulus plant at concentration of 25, 50 and 100 percent, diazinon fungicide at concentration of 100 and 200 ppm and blank samples (0 ppm). Different quality attributes including: total soluble solids, fruit juice pH, titratable acidity, flavor index of fruit, sensory attributes and total microbial counts of fruits were measured during storage periods. The results showed that application of the flower and leaf extract of Humulus lupulus plant and diazinon fungicide had no significant effect on the pH value of strawberry fruits but maintained the titratable acidity during storage periods compared to the blank samples (p>0.05). Total soluble solid content of strawberry fruits was decreased with increase of the storage time but increased with increase of the flower and leaf extract of Humulus lupulus plant concentration and compared to applied concentration of diazinon fungicide (tow concentration) lead to better brix content maintenances. Treated strawberry samples with the flower and leaf extract of Humulus lupulus plant compared to other samples obtained the higher score in case of appearance, color and texture during sensory evaluation. Microbial evaluation results, showed the ability of the flower and leaf extract of Humulus lupulus plant in microbial spoilage inhibition compared to the diazinon fungicide. According to the obtained results from different chemical, microbial and sensory evaluations, the flower and leaf extract of Humulus lupulus plant can be introduced as replacer of the common fungicide applied in strawberry preservation.
M. Shakarami, A. Shanehsazzadeh, N. Shabakhty,
Volume 20, Issue 1 (January 2020)
Abstract

The New Wave theory has recently applied for predicting wave forces on marine structures including offshore wind turbines. However, the validation of the theory in determining wave force has not been fully confirmed. However, the validation of the results for predicting stability parameters of marine structures is necessary. In the present article the prediction of the New wave theory of water surface profile, wave kinematics and offshore wind turbine monopile pier responses to the wave, including base shear, overturning moment and maximum displacement are compared to the experimental data and results from linear irregular wave time series generated from the wave spectrum. The comparisons show that the results are promising and in an acceptable level of accuracy for design purposes. Since the New wave theory takes very short time of processing in compare to real irregular time series, the theory is considered as the reliable substitute for prediction of wave forces on offshore wind turbines. The comparison with the results of the conventional 5th Stokes regular waves shows that the new wave theory is significantly more accurate in predicting wave kinematics and wave loads on offshore wind turbine monopiles.


Volume 23, Issue 5 (9-2021)
Abstract

English grain aphid, Sitobion avenae (Fabricius), is an important worldwide phloem-feeding pest of wheat due to direct sucking damage and transmission of viruses. Here, we tested the effects of six treatments on the fitness traits of S. avenae including: (1) Wheat with a 6-days aphid infestation, (2) Wheat sprayed with Biomin zinc, (3) Wheat seed treated with Bacillus subtilis, and (4 and 5) Combined treatments of Biomin zinc+pre-infestation and B. subtilis+pre-infestation as well as (6) A control treatment. Results revealed that there were significant differences among treatments concerning some allelochemical contents and aphid fitness traits. Treated with B. subtilis+pre-infestation and B. subtilis increased the total contents of phenol in the wheat leaves versus Biomin zinc+pre-infestation (183.63 mg g-1 FW). The net Reproductive rate (R0) of S. avenae was significantly reduced by B. subtilis+pre-infestation (1.533 offspring per adult) compared to the control (6.887 offspring per adult). Treated with B. subtilis+pre-infestation (0.022 d-1) significantly reduced the intrinsic rate of increase (r) of S. avenae compared with the control (0.105 d-1). The lowest (0.024) and highest (0.058) Nymph Growth Index (NGI) of aphid were found on B. subtilis+ pre-infestation and the control, respectively. Hence, it was concluded that B. subtilis+pre-infestation in wheat plants can induce systemic resistance to S. avenae, which can be used in the IPM of this aphid.

Soheil Nakhodchi, Kiumars Shakarami, Hadi Salmasi,
Volume 24, Issue 2 (February 2024)
Abstract

Inconel 718 is used in a wide range of industries such as oil and gas, nuclear, aviation, and etc. due to its excellent mechanical properties. The use of additive manufacturing (AM) to manufacture parts is increasing rapidly Due to the dimensional limitations in the manufacturing of parts using the additive manufacturing methods, these parts must be connected to other parts in different applications with the help of conventional methods such as welding. In this research, the thermal analysis of plasma welding of an Inconel 718 sheet made by SLM method using ABAQUS software is discussed. Input heat with Gaussian distribution was entered into the model by DFLUX subprogram with FORTRAN program language. In order to validate the thermal model, the temperature was measured during the welding process using a thermocouple. A relatively good match is observed between the numerical and experimental thermal analysis results. The microstructure of the welded samples was examined with an optical microscope and the microstructure of base metal, fusion zone, and heat affected zone were investigated. The dendritic structure in the welding area and the occurrence of recrystallization in the heat-affected area was evident. The tensile test results showed that the sample without welding has a higher yield and ductility.
 

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