160 research outputs found
Artificial Neural Network Model for Prediction of Liquefaction Potential in Soil Deposits
With the increase in population, the evaluation of liquefaction is becoming more important for land use planning and development. In soil deposits under undrained condition, earthquakes induce cyclic shear stresses, may lead to soil liquefaction. Artificial neural network (ANN) is one of the, artificial intelligence (AI) approaches that can be classified as machine learning. Simplified methods have been practiced by researchers to assess nonlinear liquefaction potential of soil. In order to address the collective knowledge built up in conventional liquefaction engineering, an alternative general regression neural network model is proposed in this paper. To meet this objective, a total of 30 boreholes are introduced into the model. The data includes the results of field test from (Babol, Mazandaran, Iran). The results produced by the proposed Artificial Neural Network model compared well with the determined liquefaction decision obtained by simplified methods. It provides a viable liquefaction potential assessment tool that assist geotechnical engineers in making an accurate and realistic predictions. Furthermore, this study integrates knowledge learned from field test and seismic parameters to the ongoing development of liquefaction analysis. The results show that there is liquefaction potential in western part of Babol, and in southern part of Babol no liquefaction potential were seen. In middle part and eastern part low liquefaction potential were predicted by ANNs. This study shows that neural networks are a powerful computational tool which can analyze the complex relationship between soil liquefaction potential and effective parameters in liquefaction
Approximate analysis of two-mass–spring systems and buckling of a column
AbstractMax–Min Approach (MMA) is applied to obtain an approximate solution of three practical cases in terms of a nonlinear oscillation system. After finding maximal and minimal solution thresholds of a nonlinear problem, an approximate solution of the nonlinear equation can be easily achieved using He Chengtian’s interpolation. Numerical results indicate the effectiveness of the proposed method both in respect of the whole range of involved parameters as well as the excellent agreement with the approximate frequencies and periodic solutions with the exact ones. It is predicted that MMA can be found widely applicable in engineering
A semi-analytical approach for the response of nonlinear conservative systems
This work applies Parameter expanding method (PEM) as a powerful analytical technique in order to obtain the exact solution of nonlinear problems in the classical dynamics. Lagrange method is employed to derive the governing equations. The nonlinear governing equations are solved analytically by means of He’s Parameter expanding method. It is demonstrated that one term in series expansion is sufficient to generate a highly accurate solution, which is valid for the whole domain of the solution and system response. Comparison of the obtained solutions with the numerical ones indicates that this method is an effective and convenient tool for solving these types of problems
Report of cabbage stem weevil, Ceutorhynchus pallidactylus (Col.: Curculionidae) on oilseed rape from Iran
در بررسی آفات کلزا در منطقهی مرودشت استان فارس، در نیمهی فروردین 1387، ساقههای آفتزده حاوی لارو و تخمهای مشکوک به سرخرطومی مشاهده و جمع آوری گردید. جهت دستیابی به حشرات کامل، لاروهای آفت در آزمایشگاه پرورش داده شد. این سرخرطومی با نام علمی Ceutorhynchus pallidactylus (Marsham) (= C. quadridens Panzer) (Col.: Curculionidae) شناسایی و توسط پروفسور Alziar Gabriel مورد تأیید قرار گرفت. این گونه برای اولین بار از ایران گزارش میشود
Solving Ratio-Dependent Predator-Prey System with Constant Effort Harvesting using Variational Iteration Method
Due to wide range of interest in use of bio-economic models
to gain insight into the scientific management of renewable resources like
fisheries and forestry,variational iteration method (VIM) is employed to
approximate the solution of the ratio-dependent predator-prey system with
constant effort prey harvesting.The results are compared with the results
obtained by Adomian decomposition method and reveal that VIM is very
effective and convenient for solving nonlinear differential equations
Biocontrol of soybean charcoal root rot disease by using Trichoderma Spp.
Macrophomina phaseolina
(Tassi) Goid, causing charcoal rot disease of
soybean, is one of the major factors
threatening soybean production, especially
in dry years. This pathogen remains the
prevailing causal agent of charcoal rot
disease that significantly suppresses the
yield of a variety of oilseed crops. Its wide
host range and ability to survive under arid
conditions, coupled with the ineffective use
of fungicides against it, have spurred
scientific endeavours for alternative avenues
to control this phytopathogen. Hence, the
present study aimed to provide empirical
evidence of the efficacy of fungal isolates
of Trichoderma spp. as biological control
agents against charcoal rot in soybean
(Glycine max L.). In this study Trichoderma
harzianum strains 6, 14, 17, 21, 44,
T. asperellum 26 and T. virens 32 were
evaluated as potential biological agents for
control of this disease. Mycelial growth of
M. phaseolina strain h-7 was reduced by
cell-free and volatile metabolites of
Trichoderma strains by 16.4 to 64.8%.
T. harzianum strain Tj17 significantly
(p≤0.05) reduced the incidence (to 7.3%)
and severity (to 3%) of disease 42 days after
inoculation and increased the 1000 grain
weight (to 178 g) in greenhouse conditions.
For confirmation of the greenhouse tests,
the selected antagonists were re-examined
in field trials, where this isolate reduced the
disease incidence (to 10%) and severity (to
3%). The overall results of this study show
high capability of used antagonists in
reduction of disease severity and incidence,
and resulting in increased weight of the
product. Hence, the findings reported in the
present study supported the applicability of
Tj17 isolate as possible alternative to
fungicides for the control of charcoal rot in
soybean
Performance of Promising Forage in Eastern India and Their Nutritive Value
Eastern region of India possesses large number of ruminant population (162 million) that depend on available feed resources (GOI, 2014). But, at the same time, an acute shortage of green fodder prevails in the eastern part of India that varies from 82 to 89 per cent. The main reason behind this gap is low land holding and negligible area under fodder production. Shortage of quality feed and fodder resources and neglect of forage crops led to decline in the productivity of Indian livestock. However, as a whole, country having 8.30 million ha area under fodder production (Anon, 2013) and out of this 4.90 million ha covered during Kharif season and 3.01 million ha utilized for fodder production during Rabi season. Therefore, considering the above problem, a study was conducted on fodder cum grain production to mitigate fodder scarcity problem in the eastern part of Indi
Higher-order approximation of cubic–quintic duffing model
We apply an Artificial Parameter Lindstedt-Poincaré Method (APL-PM) to find improved approximate solutions for strongly nonlinear Duffing oscillators with cubic–quintic nonlinear restoring force. This approach yields simple linear algebraic equations instead of nonlinear algebraic equations without analytical solution which makes it a unique solution. It is demonstrated that this method works very well for the whole range of parameters in the case of the cubic-quintic oscillator, and excellent agreement of the approximate frequencies with the exact one has been observed and discussed. Moreover, it is not limited to the small parameter such as in the classical perturbation method. Interestingly, This study revealed that the relative error percentage in the second-order approximate analytical period is less than 0.042% for the whole parameter values. In addition, we compared this analytical solution with the Newton– Harmonic Balancing Approach. Results indicate that this technique is very effective and convenient for solving conservative truly nonlinear oscillatory systems. Utter simplicity of the solution procedure confirms that this method can be easily extended to other kinds of nonlinear evolution equations
Analytical solutions to nonlinear mechanical oscillation problems
In this paper the Max-Min Method is utilized for solving the nonlinear oscillation problems. The proposed approach is applied to three systems with complex nonlinear terms in their motion equations. By means of this method the dynamic behavior of oscillation systems can be easily approximated using He Chengtian’s interpolation. The comparison of the obtained results from Max-Min method with time marching solution and the results achieved from literature verifies its convenience and effectiveness. It is predictable that He's Max-Min Method will find wide application in various engineering problems as indicated in the following cases
Performance of lactating crossbred cows fed on forage based total mixed ration
A study was conducted to evaluate the forage based total mixed ration (TMR) in crossbred lactating cows on milk production and nutrient digestibility. TMR was prepared by mixing wheat straw, chapped green forages (sorghum and rice bean in experiment I and oat and berseem in experiment II) and concentrate feed having 17 percent dietary CP. Two feeding experiments for the period of 60 days duration each during rainy (experiment I) and winter seasons (experiment II) were conducted in first lactating crossbred cows. In both the experiment six first lactating cows were taken and divided into 2 groups. Group 1 (T1)was fed TMR and in Group 2 (T2) ingredients were fed separately. The total daily dry matter intake (DMI) in cows fed TMR increased significantly (p˂0.01) by 15.92 percent in experiment I, when multi cut sorghum and rice bean used as green fodder. However, the differences were negligible in experiment II,when oat and berseem used as green fodder. The dry matter (DM) and crude protein (CP) digestibility as well as digestible energy (DE) value of ration were increased significantly (p˂0.01) in cows fed on TMR based on berseem and oat as green fodder in experiment II. However, differences were non-significant in experiment I, when multi cut sorghum and rice bean used as green fodder in TMR. The overall increase in milk production was recorded by 16.96 and 19.49 percent in cows fed TMR during experiment I and II, respectively. Similarly, an increase in milk production in cows fed different feeds separately was also recorded 10.74 and 6.41 percent,respectively during experiment I and II. Thus, it i
s concluded that feeding of TMR is beneficial for proportionate intake of all feed ingredients, overall
feed intake and better digestibility of nutrients resulting into higher milk production. This record was migrated from the OpenDepot repository service in June, 2017 before shutting down
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