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

Characterization of Actinomycetes Antagonist Fusariumoxysporum f.sp.passiflora Isolated from Rhizosphere Soil ofPurple Passion Fruit Plants, South Sulawesi, Indonesia

To survey rhizosphere actinomycetes as potential biocontrol against fungal diseaseof passion fruits, rhizosphere soil of the plant were used as an isolation sources. Twenty fivestrains were assigned to Streptomyces-like strain based on morphological properties of sporechain. Four strain with distinguishing characteristic based on the macroscopic appearance ofcolonies on different media, were recovery from rhizosphere soil of passion fruits plantsuggesting that various Streptomyces spp. grow surrounding of plant roots. On an agarmedium, four strains (11.43%) commonly formed a clear growth-inhibition zone against fungal pathogen of passion fruits, Fusarium oxysporum f.sp. radicalix passiflori (FORP), indicatingthat this strains can produce antifungal substances. The present results indicate that four strainare a suitable candidate for the biocontrol of fusarium wilt. Keywords: Actinomycetes, AntifungalFusarium oxysporum f.sp.passiflora Rhizosphere, Purple Passion Fruit Plants, South Sulawesi, Indonesi

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