564 research outputs found
The transcendental eigenvalue problem and its application in system identification
An accurate mathematical model is needed to solve direct and inverse problems related to engineering analysis and design. Inverse problems of identifying the physical parameters of a non-uniform continuous system based on the spectral data are still unsolved. Traditional methods, for the system identification purpose, describe the continuous structure by a certain discrete model. In dynamic analysis, finite element or finite difference approximation methods are frequently used and they lead to an algebraic eigenvalue problem. The characteristic equation associated with the algebraic eigenvalue problem is a polynomial. Whereas, the spectral characteristic of a continuous system is represented by certain transcendental function, thus it cannot be approximated by the polynomials efficiently. Hence, finite dimensional discrete models are not capable of identifying the physical parameters accurately regardless of the model order used. In this research, a new low order analytical model is developed, which approximates the dynamic behavior of the continuous system accurately and solves the associated inverse problem. The main idea here is to replace the continuous system with variable physical parameters by another continuous system with piecewise uniform physical properties. Such approximations lead to transcendental eigenvalue problems with transcendental matrix elements. Numerical methods are developed to solve such eigenvalue problems. The spectrum of non-uniform rods and beams are approximated with fair accuracy by solving associated transcendental eigenvalue problems. This mathematical model is extended to reconstruct the physical parameters of the non-uniform rods and beams. There is no unique solution for the inverse problem associated with the continuous system. However, based on several observations a conjecture is established by which the solution, that satisfies the given data by its lowest spectrum, is considered the unique solution. Physical parameters of non-uniform rods and beams were identified using the appropriate spectral data. Modal analysis experiments are conducted to obtain the spectrum of the realistic structure. The parameter estimation technique is validated by using the experimental data of a piecewise beam. Besides the applications in system identification of rods and beams, this mathematical model can be used in other areas of engineering such as vibration control and damage detection
ICT in Universities of the Western Himalayan Region in India: Status, Performance- An Assessment
The present paper describes a live project study carried out for the
universities located in the western Himalayan region of India in the year 2009.
The objective of this study is to undertake the task of assessment regarding
initiative, utilization of ICT resources, its performance and impact in these
higher educational institutions/universities. In order to answer these,
initially basic four- tier framework was prepared. Followed by a questionnaire
containing different ICT components 18 different groups like vision, planning,
implementation, ICT infrastructure and related activities exhibiting
performance. Primary data in the form of feedback on the five point scale, of
the questionnaire, was gathered from six universities of the region. A simple
statistical analysis was undertaken using weighted mean, to assess the ICT
initiative, status and performance of various universities. In the process, a
question related to Performance Indicator was identified from each group, whose
Coefficient of Correlation was calculated. This study suggests that a
progressive vision, planning and initiative regarding academic syllabi, ICT
infrastructure, used in training the skilled human resource, is going to have a
favourable impact through actual placement, research and play a dominant role
at the National and International level.Comment: International Journal of Computer Science Issues, IJCSI Volume 6,
Issue 2, pp44-52, November 200
Bifurcation in cell cycle dynamics regulated by p53
We study the regulating mechanism of p53 on the properties of cell cycle
dynamics in the light of the proposed model of interacting p53 and cell cycle
networks via p53. Irradiation (IR) introduce to p53 compel p53 dynamics to
suffer different phases, namely oscillating and oscillation death (stabilized)
phases. The IR induced p53 dynamics undergo collapse of oscillation with
collapse time \Delta t which depends on IR strength. The stress p53 via IR
drive cell cycle molecular species MPF and cyclin dynamics to different states,
namely, oscillation death, oscillations of periods, chaotic and sustain
oscillation in their bifurcation diagram. We predict that there could be a
critical \Delta t_c induced by p53 via IR_c, where, if \Delta t < \Delta t_c
the cell cycle may come back to normal state, otherwise it will go to cell
cycle arrest (apoptosis)
Feeding and reproductive behaviour of pigeon slender louse, Columbicola columbae (Phthiraptera, Insecta, Ischnocera)
Columbicola columbae, the pigeon slender louse mostly feeds upon the barbules of feathers but in addition to this it also feeds upon skin scurf, epidermal scales, sheaths of growing feathers, pellicle of skin etc. C. columbae is exclusively keratin feeder and does not take host blood. Any sex or stage related difference in feeding habit has not been recorded. It neither harbours any triturating agent in the crop nor is involved in cannibalism or predation. C. columbae exhibits sub-feminal mating behaviour (i.e., the male is under the female). Completecopulation lasts about 10 hours. The louse prefers the wing and tail feathers for oviposition. The eggs are generally laid on the ventral surface of the first row of undercoverts of wing feathers. Every event that takes place prior to eclosion of nymph, the time required for detachment of operculum and the freeing of nymph has been noted during hatching
Levofloxacin induced psychosis: a rare case report
Levofloxacin is a commonly prescribed antibiotic for treating bacterial infections in routine clinical practice. AÂ wide range of side-effects have been ascribed to the quinolone group of drugs, the most common being gastrointestinal. Central nervous system is rarely involved; neuropsychiartic complications are among the least reported adverse reactions. We report a rare case of levofloxacin induced acute psychosis in a young male presenting in out-patient department with signs of urinary tract infection along with pneumonitis
Interaction of silicon with cell wall components in plants: A review
Silicon (Si) is the utmost element of the earth's crust involved in various plant processes. Despite being a non-essential element of the plant, its role in plant tolerance is appreciable. The interaction of Si with the plant cell wall provides structural and mechanical strength to the plants. This review article discusses the different forms of silica (simple to complex), the nature of Si, and its interaction with plant cell wall components after being taken up by plants. Ligands of plant cell wall like hemicellulose, pectin, lignin, cellulose, callose, and mixed-linked glucans (MLG) are the possible linker, which helps the Si in crosslinking with the plant cell wall. This review also incorporates the interrelation of Si with different cell wall components, the role of Si-cell wall complexes in different stress alleviation, and enhancing stress resistance in plants. Accumulation of Si after crosslinking with the cell wall provides rigidity and stability to the plant wall and enhances mechanical strength. Many studies have been conducted on the Si role in different stress alleviation, but little knowledge is available on how plants react when Si is taken up, how Si interacts with the plant cells, how Si accumulation is enhanced by the plant itself, how the possible ligands help Si in bonding with the cell wall. This study helps to understand the relationship of cell wall components with Si and to think about the precise bonding patterns between them
Genetic analysis of japonica x indica recombinant inbred lines and characterization of major fragrance gene by microsatellite markers
Traditional basmati rice varieties are very low yielding due to their tendency to lodging and increasing susceptibility to diseases. To improve the characters of basmati rice variety and study the inheritance of various physio-morphological and quality characters, F5 population comprising of 204 lines from the cross between NPT II (non-aromatic, japonica) and Taraori Basmati or HBC19 (aromatic, indica), were evaluated. Ample amount of genetic variability was observed for the characters plant height, tillers per plant, kernel length, kernel breath and L/B ratio. The grain yield/plant showed positive correlation with productive tiller/plant and test weight. Path coefficient analysis showed that the productive tiller/plant and test weight contribute to grain yield/ plant through direct effect. The parent off-spring regression was high for all the characters under study suggesting improvement of these characters by mere selection. Based on divergence study, 204 lines were categorized in seven clusters whereas parents were grouped in different clusters. Molecular restricted selection using specific SSR markers with depicting high correlation with aroma could offer great promise to select high yielding rice among high aroma lines. A total of 54 randomly selected F5 plants were subjected to SSR marker analysis using SSR markers. The F5 plants had an allele from either of the two parental lines (homozygous condition) or alleles from both the parental rice varieties (heterozygous condition). At some SSR loci, new/recombinant alleles were observed, which indicate the active recombination between genomes of two rice varieties and can be used for linkage mapping once complete homozygosity is achieved. SSR allelic profile based on two dimensional principal component analysis demonstrated high level of diversity among parents and F5 plants spread between them.Keywords: Oryza sativa L., basmati, microsatellite, phenotyping, rice, recombinant inbred lines (RILs)African Journal of Biotechnology Vol. 12(32), pp. 5022-502
Impact of drip irrigation and fertigation scheduling on tomato crop - An overview
The primary objective of this review study was to determine the best irrigation and fertilizer scheduling practice in order to achieve maximum yield with maximum water and fertilizer use efficiency and highest nutrient uptake. It is found nutrient use efficiency could be as high as 90 per cent in fertigation as compared to 40 to 60 per cent in conventional methods. The amount of fertilizer lost through leaching can be as low as 10 per cent in fertigation whereas it is 50 per cent in the traditional system. It is observed that irrigation and fertigation scheduled at 75% ET and at 75% RDF, respectively could be a good alternate for saving water and nutrients with enhanced nutrient uptake, growth, yield and quality of crops. In this paper, the literature pertaining to the different aspects of fertigation and irrigation scheduling are reviewed
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