3,306 research outputs found
Particle swarm optimisation algorithms and their application to controller design for flexible structure systems
Particle swarm optimisation (PSO) is one of the relatively new optimisation techniques, which has become increasingly popular in tuning and designing controllers for different applications. A major problem is that simple PSO have a tendency to converge to local optima, mainly, due to lack of diversity in the particles as the algorithm proceeds and improper selection of other parameters. Maintaining diversity within a population is challenging for PSO, especially for dynamic problems. In order to increase diversity in the search space and to improve convergence, a new variant of PSO is proposed. The increased interest from industry and real-world applications has led to several modifications in the conventional algorithms so as to deal with multiple conflicting objectives and constraints. A modified multi-objective PSO (MOPSO) proposal is made which will allow the algorithm to deal with multi-objective optimisation problems. The main challenge, in designing a MOPSO algorithm, is to select local and global best for each particle so as to obtain a wide range of solutions that trade-off among the conflicting objectives. In the proposed algorithm, a new technique is introduced that combines external archive and non-dominated fronts of the current population in order to select the global best for each particle. The effectiveness of the proposed algorithm is assessed with two examples in controller design for vibration control of flexible structure systems and satisfactory results have been obtained
System identification of a twin rotor multi-input multi-output system using adaptive filters with pseudo random binary input
This paper presents an investigation into the development of a parametric model of pitch movement of a twin rotor multi-input multi-output system (TRMS) using adaptive finite impulse response (FIR) models. The TRMS is a laboratory platform designed for control experiments. In certain aspects, its behaviour resembles that of a helicopter. It typifies a high-order nonlinear system with significant cross coupling between its two channels. The system is initially excited with PRBS signals of different bandwidths to ensure that all resonance modes are captured. The PRBS magnitude is selected so that it does not drive the system out of its linear operating range. Then, an adaptive FIR filter structure with LMS, NLMS, and genetic algorithm (GA) with LMS algorithms is investigated to identify the system and extract its parametric model. Effects of filter taps, step-size and system convergence are also studied. Performances of the employed techniques are assessed and presented in time and frequency domains
Stability Testing of Beclomethasone Dipropionate Nanoemulsion
Purpose: To perform stability studies on a nanoemulsion formulation containing beclomethasone dipropionate (BD) and prepared by spontaneous emulsification method.Method: A nanoemulsion (o/w) containing BD was prepared using eucalyptus oil, Tween-40, ethanol and distilled water. The nanoemulsions were characterized by droplet size, pH, viscosity, conductivity and refractive index. Stability studies were performed according to International Council on Harmonization (ICH) guidelines over a period of 3 months. Droplet size, pH, viscosity, conductivity and refractive index were determined monthly for 3 months. The shelf-life of the nanoemulsion formulation was determined by accelerated stability testing.Results: The droplet size, conductivity, viscosity, pH and refractive index of the optimized formulations did not change significantly (p ≥ 0.05) after 3 months of storage at room temperature (25 ºC). The shelf life was 1.83 years at room temperature.Conclusion: The study demonstrates that the physical and chemical stability of BD is enhanced when it is formulated as a nanoemulsion.Keywords: Nanoemulsion, Beclomethasone dipropionate, Shelf-life, Accelerated stability, Viscosity, Conductivity, Refractive inde
Genetic diversity analysis of rice (Oryza sativa L.) landraces through RAPD markers
The molecular marker is a useful tool for assessing genetic variations and resolving cultivar identities. Information on genetic diversity and relationships among rice landraces from Bangladesh is currently very limited. Thirty-five rice genotypes including 33 landraces and 01 HYV of Bangladesh and 1 Indian landrace of particular interest to breeding programs were evaluated by means of random amplified polymorphic DNA (RAPD) technique. For molecular characterization, RAPD markers viz., OPC 03, OPC 04 and OPA 01 gave reproducible and distinct polymorphic amplified products. A total of 20 RAPD bands were scored of which 15 polymorphic amplification products were obtained by using these arbitrary primers. The size of amplified fragments were ranged from 550 to 1775 bp. Based on analysis performed on a similarity matrix using UPGMA, 35 genotypes were grouped into 2 main clusters. Landrace Sylhet balam and Mota aman was totally different from other genotypes. The information will facilitate selection of genotypes to serve as parents for effective rice breeding programs in Bangladesh. DOI: http://dx.doi.org/10.3329/ijarit.v4i1.21099 Int. J. Agril. Res. Innov. & Tech. 4 (1): 77-87, June, 201
Impacts of three pesticides on arthropod biodiversity in brinjal agro-ecosystem
A field study was conducted to find out the impact of three selected pesticides on arthropod biodiversity in brinjal agro-ecosystem during 2011-2012 at Bangabandhu Sheikh Mujibur Rahman Agricultural University (BSMRAU). Twenty-six arthropod species were observed through visual searching method out of which 18 were insect pest species (from 14 families under 8 orders) and 8 were natural enemies (from 8 families under 6 families). Twenty one species of surface dwelling arthropods were caught in pitfall traps method, 12 of them were insect pest species (from 11 families under 8 orders) and 9 were natural enemies (from 9 families under 5 orders). Formicidae was the most abundant family among them. Bacillus thuringiensis (Bt) and Tracer 45SC (Spinosad) were less harmful to arthropod pest species as well as natural enemies in the brinjal agro-ecosystem. Proclaim 5SG reduced the overall abundance of arthropod species. Bacillus thuringiensis (Bt) and Tracer 45SC were relatively safe for natural enemies and therefore would be fit well into integrated pest management (IPM) against BSFB of brinjal crop.Int. J. Agril. Res. Innov. & Tech. 8 (1): 55-61, June, 201
First report on black spot disease of Phyllanthus emblica L. fruits caused by Thielaviopsis paradoxa in Bangladesh
Fruit spot disease of Phyllanthus emblica L. is one of theproblems, which reduce the quality of the fruits at pre-harvest period. Fungal pathogen was isolated using tissue planting methods during November 2016 to December 2017. The fungus, Thielaviopsis paradoxa was identified using both morphological and molecular characterization based on internal transcribe spacer (ITS) region of ribosomal DNA (rDNA). Mycelial growth of the isolated fungus was evaluated on six different fungal culture media viz, potato sucrose agar (PSA), Richard agar (RA), carrot agar (CA), potato dextrose agar (PDA), honey peptone agar (HPA) and Hansen’s agar (HA) in which RA and HPA media provided the utmost growth. The optimum temperature of the fungus was recorded at 25 to 35ºC. Alternate cycle of 12h/12h light dark and neutral to basic pH was preferred by the studied fungus. Aqueous crude extracts of three plants (garlic, black cumin, and turmeric) were evaluated against the isolated fungus in which the highest inhibition was recorded due to garlic extract. Two food preservatives (sodium benzoate and vinegar) were also tested in which sodium benzoate (100 mM) was most efficient for the inhibition of T. paradoxa. Therefore, garlic and food preservative-sodium benzoate could be used to control this fungal growth associated with amla fruits. To the best of our knowledge, occurrence of T. paradoxa on amla fruits is a new record in Bangladesh.
Int. J. Agril. Res. Innov. Tech. 10(2): 38-46, December 202
Effects of artificial feeds on growth and production of fishes in Polyculture
A study on the effects of artificial feeds on growth and production of fishes along with some limnological conditions were conducted in polyculture system. Species of Indian major carp (Cirrhinus mrigala) and exotic fishes (Hypophthalmicthys molitrix and Oreochromis niloticus) were stocked in six ponds under two treatments, each with three replications. Stocking rate in both treatments was 100 fish per decimal at the ratio of silver carp: tilapia: mrigal = 2: 2: 1. Fertilization and artificial feeds were given in Ttreatment 1 (T1) and only fertilization was done in Treatment 2 (T2). Wheat bran, rice bran and soybean meal were given daily as artificial feed in T1 in the ratio of wheat bran: rice bran: soybean meal = 2: 2: 1 (by wt). Urea, T.S.P and cow dung were applied fortnightly at the rate of 60 g deci-1, 90 g deci-1 and 2 kg deci-1 respectively. Water temperature, transparency, pH, dissolved oxygen, free CO2, total alkalinity, PO4-P and NO3-N were determined fortnightly and phytoplankton and zooplankton were studied fortnightly. These limnological conditions were more or less similar in the ponds under two treatments and were within suitable ranges. Calculated gross and net yields of fish were 16.56 and 12.48 ton ha-1 respectively in case of fertilization and artificial feeding application (T1) and 9.99 and 5.91 ton ha-1 respectively in case of only fertilization (T2). Application of artificial feed in T1 significantly increased the growth and production of fish more than two times which indicates that artificial feeding in polyculture is very useful for increasing fish production. DOI: http://dx.doi.org/10.3329/ijarit.v4i2.22637 Int. J. Agril. Res. Innov. & Tech. 4 (2): 11-15, December, 201
A review of the mosquito species (Diptera: Culicidae) of Bangladesh
© The Author(s). 2016 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated. The attached file is the published version of the article
Marker-assisted Backcrossing for Identification of Salt Tolerant Rice Lines
SSR or microsatellite markers are proved to be ideal for making genetic maps, assisting selection and studying genetic diversity in germplasm. SSR markers are playing important role to identify gene for salt tolerance that can be helpful for plant breeders to develop new cultivars. The experiment was conducted during the period from July 2009 to November 2010 in the experimental field and Biotechnology Laboratory of Plant Breeding Division, Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh to identify salt tolerant rice line of BC1F1 progenies of Binadhan-5 x FL-478 using SSR markers. Salt tolerant genotype, FL-478 was crossed with high yielding variety, Binadhan-5. Randomly selected 40 BC1F1 progenies along with their two parents (Binadhan-5, FL-478 and F1) were genotyped with microsatellite or SSR markers for identification of salt tolerant rice lines. Parental polymorphism survey was assayed by 10 SSR markers and three polymorphic SSR markers viz., RM 336, RM 510, and RM 585 were selected to evaluate BC1F1 rice lines for salt tolerance. In respect of Primer RM 336, 11 lines were found as salt tolerant and 25 lines were heterozygous and 3 lines were susceptible. Primer RM 510 identified two tolerant, 14 heterozygous and 22 susceptible lines. And primer RM 585 identified 4 lines as tolerant and 35 lines as susceptible. Thus, these markers could be efficiently used in tagging salt tolerant genes, in marker-assisted selection and quantitative trait loci (QTL) mapping. The selected BC1F1 could be used for developing BC2F1 and BC2F2 and mapping genes for salinity tolerance. DOI: http://dx.doi.org/10.3329/ijarit.v2i2.14008 Int. J. Agril. Res. Innov. & Tech. 2 (2): 1-8, December, 201
Distribution System Power Losses Minimization Using Network Reconfiguration
This paper shows an efficacious approach for the perfect arrangement of a distribution system. To discover the switches best fusion, which outcomes a minimal power loss for the distribution radial configuration. To resolve the non-linear optimization problem here Modified Particle Swarm Optimization (MPSO) technique is projected for the minimization of system power losses. MPSO is an improved Binary Particle Swarm Optimization (BPSO) with modification of particle velocity in search space. To reveal the fitness of the anticipated approach relative investigation of MPSO with other preceding optimization techniques is done. To reconfigure a distribution network system, under base case loading conditions, IEEE 33 bus radial system is used. It is inspected that MPSO executes well as compare to GA, ACA and SPSO in respective of significance of power losses, which are improved and minimized up to 138.9275kW and profile of voltage, which are enhanced and stabilized up to 0.94234 per unit in terms of minimum voltage in the system
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