Robustness Study of Fractional Order PID Controller Optimized by Particle Swarm Optimization in AVR System

In this paper a novel design method for determining fractional order PID (PIλDµ) controller parameters of an AVR system using particle swarm optimization algorithm is presented. This paper presents how to employ the particle swarm optimization to seek efficiently the optimal parameters of PIλDµ controller. The robustness study is made for this controller against parameter variation of AVR system. This work has been simulated in MATLAB environment with FOMCON (Fractional Order Modeling and Control) tool box.The proposed PSOPIλDµ controller has superior performance and robust compared to GA tuned PIλDµ controller. The results are also compared with PSO tuned PID controller

Electro-Mechanical Actuator: A Simulation Study

Electro-Mechanical Actuator (EMA) modeling and simulation using Simulink block set has been implemented and tested with input step and repeated sequences. The results obtained from this simulation are satisfactory. This simulation model can be used for developing EMA health condition monitoring techniques and educational purpose. Basically a simplified and complete Simulink based approach is presented

Histogenesis of Peyer’s patches in Ovine foetus (Ovis aries)

Tissue pieces of jejunum and ileum from different prenatal age groups of sheep were collected from Corporation slaughter house, Perambur, Chennai. By three months of foetal age in sheep, the Peyer’s patches appeared as an aggregation of lymphocytes in the propria submucosa of the jejunum and ileum. The lymphocytic aggregation appeared only in the antimesenteric part of the jejunum and ileum. By four months of foetal age, the circumscribed nodular aggregations of lymphocytes were found enlarged giving a follicle-like appearance. The capsular connective tissue was predominated by reticular fibres and a few collagen fibres. The dome area of the follicle consisted of closely packed small-sized lymphocytes which appeared darker than the basal area. The smooth muscle fibres of muscularis mucosae were not continuous throughout and were absent in the follicle having domes. In five months-old foetuses, the jejunal and ileal Peyer’s patches were distinctly observed as follicles. The follicle showed a distinct outer cortex and an inner lighter medulla. Numerous small-sized lymphocytes were observed in the outer cortex and few lymphoblasts, medium sized lymphocytes and reticular cells were observed in the medulla. Keywords: Histogenesis; Peyer’s patches; Ovine foetus

Antinociceptive and anti-Inflammatory effects of the standardized oil of Indian Callistemon lanceolatus leaves in experimental animals

The effect of Callistemon lanceolatus (Syn. C. citrinus curtis; Family: Myrtaceae) leaf oil was studied for the antinociceptive and anti-inflammatory activity in experimental animals. C. lanceolatus, 25 – 100 mg/kg administered orally for 3 days exhibited graded dose response equivalent to 21.95% - 89.90% protection in the tail flick latent test in rat. The C. lanceolatus oil (50 and 100 mg/kg, given orally for 3 days) was effective in hot plate reaction time (64.05% and 112.97%,

Formulation and Evaluation of Buccoadhesive Drug Delivery System for Lovastatin

Lovastatin, a hyperlipedemic agent used in the treatment of hypercholesterolemia, has poor bioavailability ( less than 5%) due to the first pass metabolism and thus the dosing frequency is more, as a result of which several side effects occurred with the current dosage form. The present study aimed to formulate and evaluate buccoadhesive tablets of Lovastatin using mucoadhesive polymer such as Carbopol 934P, Hydroxypropylmethyl cellulose (K4M, K100M) and sodium CMC. The different formulations of buccoadhesive tablet of Lovastatin were prepared by direct compression method and characterized for physicochemical parameters such as thickness, content uniformity, weight variation, hardness, and friability test. The swelling index, % matrix erosion, surface pH, bioadhesive strength, bioadhesive time and in-vitro drug release are also carried out which has been important aspect for success of buccoadhesive tablets. The FTIR study was carried out for drug and polymer compatibility.  All the formulation showed satisfactory tablet properties. Formulation (F5) containing Carbopol 934P and HPMC K4M in the ratio of (1:1) showed good bioadhesive strength and maximum drug release of 95.80% in 8 hours. The surface pH of all tablets was found to be satisfactory, close to buccal pH, hence no irritation would observe with these tablets. FTIR studies showed no evidence of interaction between drug and polymers. Keywords: Buccoadhesive tablets, Lovastatin, FTIR, Carbopol 934P, in-vitro drug releas

STATIC AND TRANSIENT ANALYSIS OF COMPOSITE LEAF SPRING

Leaf springs are mainly used in suspension systems to absorb shock loads in automobiles like light motor vehicles, heavy duty trucks and in rail systems. It carries lateral loads, brake torque, driving torque in addition to shock absorbing. This work deals with finding a suitable composite material that can be a replacement for conventional steel leaf spring. The stress and displacements have been calculated using theoretically as well as using ANSYS for steel leaf spring and composite leaf spring. The model is designed in CREO software for the vehicle Mahindra “Model - commander 650 di”. Analysis is done in ANSYS software for different materials (Steel, Kevlar and E-Glass Epoxy). The static analysis is done to determine the deformation, stress and strain for different materials. A comparative study has been made between steel and composite leaf spring with respect to strength and weight. Transient analysis is done to determine the deformation, stress with respect to time for different materials. Fatigue analysis is done to determine the fatigue life for steel, E glass epoxy and Kevlar leaf spring

Conditioned Medium Reconditions Hippocampal Neurons against Kainic Acid Induced Excitotoxicity: An In Vitro

Stem cell therapy is gaining attention as a promising treatment option for neurodegenerative diseases. The functional efficacy of grafted cells is a matter of debate and the recent consensus is that the cellular and functional recoveries might be due to “by-stander” effects of grafted cells. In the present study, we investigated the neuroprotective effect of conditioned medium (CM) derived from human embryonic kidney (HEK) cells in a kainic acid (KA) induced hippocampal degeneration model system in in vitro condition. Hippocampal cell line was exposed to KA (200 µM) for 24 hrs (lesion group) whereas, in the treatment group, hippocampal cell line was exposed to KA in combination with HEK-CM (KA + HEK-CM). We observed that KA exposure to cells resulted in significant neuronal loss. Interestingly, HEK-CM cotreatment completely attenuated the excitotoxic effects of KA. In HEK-CM cotreatment group, the cell viability was ~85–95% as opposed to 47% in KA alone group. Further investigation demonstrated that treatment with HEK-CM stimulated the endogenous cell survival factors like brain derived neurotrophic factors (BDNF) and antiapoptotic factor Bcl-2, revealing the possible mechanism of neuroprotection. Our results suggest that HEK-CM protects hippocampal neurons against excitotoxicity by stimulating the host’s endogenous cell survival mechanisms

Indian summer monsoon onset forecast skill in the UK Met Office initialized coupled seasonal forecasting system (GloSea5-GC2)

Accurate and precise forecasting of the Indian monsoon is important for the socio-economic security of India, with improvements in agriculture and associated sectors from prediction of the monsoon onset. In this study we establish the skill of the UK Met Office coupled initialized global seasonal forecasting system, GloSea5-GC2, in forecasting Indian monsoon onset. We build on previous work that has demonstrated the good skill of GloSea5 at forecasting interannual variations of the seasonal mean Indian monsoon using measures of large-scale circulation and local precipitation. We analyze the summer hindcasts from a set of three springtime start-dates in late April/early May for the 20-year hindcast period (1992-2011). The hindcast set features at least fifteen ensemble members for each year and is analyzed using five different objective monsoon indices. These indices are designed to examine large and local-scale measures of the monsoon circulation, hydrological changes, tropospheric temperature gradient, or rainfall for single value (area-averaged) or grid-point measures of the Indian monsoon onset. There is significant correlation between onset dates in the model and those found in reanalysis. Indices based on large-scale dynamic and thermodynamic indices are better at estimating monsoon onset in the model rather than local-scale dynamical and hydrological indices. This can be attributed to the model's better representation of large-scale dynamics compared to local-scale features. GloSea5 may not be able to predict the exact date of monsoon onset over India, but this study shows that the model has a good ability at predicting category-wise monsoon onset, using early, normal or late tercile categories. Using a grid-point local rainfall onset index, we note that the forecast skill is highest over parts of central India, the Gangetic plains, and parts of coastal India - all zones of extensive agriculture in India. El Niño Southern Oscillation (ENSO) forcing in the model improves the forecast skill of monsoon onset when using a large-scale circulation index, with late monsoon onset coinciding with El Niño conditions and early monsoon onset more common in La Niña years. The results of this study suggest that GloSea5's ensemble-mean forecast may be used for reliable Indian monsoon onset prediction a month in advance despite systematic model errors

Analysis of the Basidiomycete Coprinopsis cinerea Reveals Conservation of the Core Meiotic Expression Program over Half a Billion Years of Evolution

Coprinopsis cinerea (also known as Coprinus cinereus) is a multicellular basidiomycete mushroom particularly suited to the study of meiosis due to its synchronous meiotic development and prolonged prophase. We examined the 15-hour meiotic transcriptional program of C. cinerea, encompassing time points prior to haploid nuclear fusion though tetrad formation, using a 70-mer oligonucleotide microarray. As with other organisms, a large proportion (∼20%) of genes are differentially regulated during this developmental process, with successive waves of transcription apparent in nine transcriptional clusters, including one enriched for meiotic functions. C. cinerea and the fungi Saccharomyces cerevisiae and Schizosaccharomyces pombe diverged ∼500–900 million years ago, permitting a comparison of transcriptional programs across a broad evolutionary time scale. Previous studies of S. cerevisiae and S. pombe compared genes that were induced upon entry into meiosis; inclusion of C. cinerea data indicates that meiotic genes are more conserved in their patterns of induction across species than genes not known to be meiotic. In addition, we found that meiotic genes are significantly more conserved in their transcript profiles than genes not known to be meiotic, which indicates a remarkable conservation of the meiotic process across evolutionarily distant organisms. Overall, meiotic function genes are more conserved in both induction and transcript profile than genes not known to be meiotic. However, of 50 meiotic function genes that were co-induced in all three species, 41 transcript profiles were well-correlated in at least two of the three species, but only a single gene (rad50) exhibited coordinated induction and well-correlated transcript profiles in all three species, indicating that co-induction does not necessarily predict correlated expression or vice versa. Differences may reflect differences in meiotic mechanisms or new roles for paralogs. Similarities in induction, transcript profiles, or both, should contribute to gene discovery for orthologs without currently characterized meiotic roles