Predictive Control of Axis Drift in Linear Motion Control Systems

The positional accuracy of a linear motion system used in machine tools can be enhanced by using closed loop feedbackinvolving a positional measurement by means of an encoder.The position error is developed in the linear motion system because of the thermal expansion of the ball screw assembly and also due to the error in encoder measurement values. The traditional error compensation and correction methods used in a linear motion system do not satisfy all the dynamic performance requirements and constraints. In this paper, a Model Predictive Control (MPC) algorithm is proposed to reduce the position error of the linear motion control system at no-load and light load conditions. The future predictions made by the model predictive controller are based on the behaviour of the ball screw motion mechanism and encoder measurements to enhance the position accuracy of the linear motion system. The performance of the proposed model predictive controller is verified for no-load conditions in ball screw based linear motion system, and the results have been shown to outperform the current Proportional, Integral and Derivative (PID) and Fractional Order Proportional, Integral and Derivative(FOPID) control methods

Evaluation and comparison of native and recombinant LipL21 protein-based ELISAs for diagnosis of bovine leptospirosis

A 21-kDa leptospiral lipoprotein (LipL21) was evaluated for its diagnostic potential to detect bovine leptospirosis by ELISA. Both native LipL21 (nLipL21) and recombinant LipL21 (rLipL21) proteins were tested and compared regarding diagnostic efficiency, and no statistically significant difference was observed. The sensitivity of rLipL21 ELISA for 62 microscopic agglutination test (MAT) positive sera was 100% and the specificity with 378 MAT negative sera was 97.09%. Thus, rLipL21 protein-based ELISA could be used as an alternative to MAT for the diagnosis of bovine leptospirosis

Molecular Dynamics Simulation Study and Hybrid Pharmacophore Model Development in Human LTA4H Inhibitor Design

Human leukotriene A4 hydrolase (hLTA4H) is a bi-functional enzyme catalyzes the hydrolase and aminopeptidase functions upon the fatty acid and peptide substrates, respectively, utilizing the same but overlapping binding site. Particularly the hydrolase function of this enzyme catalyzes the rate-limiting step of the leukotriene (LT) cascade that converts the LTA4 to LTB4. This product is a potent pro-inflammatory activator of inflammatory responses and thus blocking this conversion provides a valuable means to design anti-inflammatory agents. Four structurally very similar chemical compounds with highly different inhibitory profile towards the hydrolase function of hLTA4H were selected from the literature. Molecular dynamics (MD) simulations of the complexes of hLTA4H with these inhibitors were performed and the results have provided valuable information explaining the reasons for the differences in their biological activities. Binding mode analysis revealed that the additional thiophene moiety of most active inhibitor helps the pyrrolidine moiety to interact the most important R563 and K565 residues. The hLTA4H complexes with the most active compound and substrate were utilized in the development of hybrid pharmacophore models. These developed pharmacophore models were used in screening chemical databases in order to identify lead candidates to design potent hLTA4H inhibitors. Final evaluation based on molecular docking and electronic parameters has identified three compounds of diverse chemical scaffolds as potential leads to be used in novel and potent hLTA4H inhibitor design

In vitro propagation of a rare succulent medicinal plant Caralluma diffusa (Wight) N.E.Br

Caralluma diffusa (Wight) N.E.Br is rare and an endemic medicinally important plantbelonging to the family Asclepiadaceae. A cost effective and efficient protocol has beendescribed in the present work for large scale and rapid propagation through in vitro organogenesis using nodal explants cultured on Murashige and Skoog’s (MS) media fortifiedwith BAP, 2,4-D, NAA and Kn. The highest frequency ( 83.3%) of callus was observed in MSmedium containing NAA (2mg/L) in combination with BAP (0.5mg/L) + Kn (0.25mg/L).Development of highest percentage of shoot organogenesis (82.4%) occurred when the calliwere sub cultured in MS medium supplemented with combination of BAP + NAA + Kn (2.0+ 0.5 + 0.25mg/L). Multiple shoots were induced from the nodal segments cultured onmedium containing BAP or Kn alone or in combination. Highest number of shoots(6.40±0.34) and maximum length of shoots (6.61±1.01cm) were obtained on MS mediumcontaining BAP (2.5mg/L). These shoots were then cultured on half strength MS mediumsupplemented with various concentrations of IBA and NAA. Highest percentage of rooting(78.4%) and mean length of rootlets was observed on IBA (0.5mg/L) in combination withNAA (0.5mg/L). In vitro derived plantlets were hardened and acclimatized. About 98% ofplantlets survived in field condition. The method described here can be successfully employed for large scale multiplication, long term in vitro conservation. This is the firstreport on indirect organogenesis of universally threatened cacti C. diffusa

Wild habits of Kolli Hills being staple food of inhabitant tribes of eastern Ghats, Tamil Nadu, India

432-437There is a proverb in Tamil that “Foods are medicines” “Medicines are foods”. Still it is being maintained by the folks, whose food habits depends on wild habits. Hence, the present study emphasis the documentation of traditional knowledge of Malayalis folks pertaining to their food habits which is necessary for the benefit of mankind. A survey has been made and identified 38 wild species belonging to 21 families. The roots, rhizomes and tubers of these plants are not only used as foods but are also consumed to maintain their health status. Thus these plants are used for general medicinal purposes also. Most of the tubers and roots are consumed after cooking, while some of them are eaten raw. Botanical name, family, vernacular name, life form/habit, parts used for food and medicine, mode of preparation and consumption are recorded for each species

Predictive Control of Axis Drift in Linear Motion Control Systems

827-836The positional accuracy of a linear motion system used in machine tools can be enhanced by using closed loop feedbackinvolving a positional measurement by means of an encoder.The position error is developed in the linear motion system because of the thermal expansion of the ball screw assembly and also due to the error in encoder measurement values. The traditional error compensation and correction methods used in a linear motion system do not satisfy all the dynamic performance requirements and constraints. In this paper, a Model Predictive Control (MPC) algorithm is proposed to reduce the position error of the linear motion control system at no-load and light load conditions. The future predictions made by the model predictive controller are based on the behaviour of the ball screw motion mechanism and encoder measurements to enhance the position accuracy of the linear motion system. The performance of the proposed model predictive controller is verified for no-load conditions in ball screw based linear motion system, and the results have been shown to outperform the current Proportional, Integral and Derivative (PID) and Fractional Order Proportional, Integral and Derivative(FOPID) control methods

Micropropagation prospective of cotyledonary explants of <i>Decalepis hamiltonii</i> Wight & Arn.—An endangered edible species

256-260The study was undertaken to standardize the development of callus, shoot and root regeneration from cotyledonary explant of Decalepis hamiltonii Wight & Arn. through the tissue culture techniques. The MS medium supplemented with 6-benzyl amino purine (BA), 2,4-dichlorophenoxy acetic acid (2,4-D), kinetin (Kn), gibberelic acid (GA3), indole acetic acid (IAA), indole butyric acid (IBA) and 1-naphthalene acetic acid (NAA) was used for callus, shoot and root regeneration. The maximum percentage (82.0%)of callus formation was achieved on 0.5 mg/L BA in combination with 0.05 mg/L Kn, followed by 78.5% of callus formation on 0.5 mg/L 2,4-D fortified with 0.05 mg/L Kn. The highest shoot proliferation (4.6 shoots/callus) and shoot length (6.9 cm) was achieved on 1.0 mg/L BA combined with 0.1 mg/L GA3, followed by 3.8 shoots per callus and 5.8 cm shoot length on 1.0 mg/L IAA combined with 0.1 mg/L GA3. The highest root formation (38.2 roots/shoot) and root length (11.8cm) was achieved on ½ strength MS medium fortified with 0.4 mg/L IBA, followed by 36.5 roots per shoot and root length of 10.7 cm on 0.4 mg/L NAA. The well-developed rooted plantlets were hardened in the mixtures of forest soil, soil and vermiculite (1:1:1) and 97.5% plantlets survived after hardening