887 research outputs found

    Teaching Learning based Optimization Applied to Mechanical Constrained Design Problems

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    Amidst all the evolutionary optimization algorithms Teaching–Learning-Based Optimization (TLBO) seems to be a promising technique with relatively competitive performances. It outperforms some of the well-known metaheuristics regarding constrained benchmark functions, constrained mechanical design, and continuous non-linear numerical optimization problems. This dissertation presents the application of TLBO to various problems of mechanical engineering. Both constrained and unconstrained optimization has been performed on some manufacturing processes and design problems. Parametric optimization of three non-conventional machining processes namely electro-discharge machining, electrochemical machining and electro-chemical discharge machining, have been carried out and the results are compared with other evolutionary algorithms. Improvement in the existing TLBO algorithm has been incorporated in this dissertation using two schemes namely bit string mutation and replacement of worst solutions with fresh ones. Performance evaluation of these modifications have been presented in this dissertation by solving six optimization problems using original TLBO and proposed modifications. It has been found that better results are achieved in reaching the global optimal values by the use of these modifications. However, the results prefer the use of bit string mutation over scheme of replacing the worst solutions with fresh solutions in addition to the original logic of TLBO. The bit wise mutation and replacement of the worst solutions with fresh ones, proved an added advantage to the existing algorithm. Both these modifications resulted in a steeper convergence rate and finally provided global optimal solutions, and in some cases even better solutions than previously published results

    Fourfold degenerate columnar-dimer ground state in square lattice antiferromagnets

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    We construct and study two frustrated quantum spin-1/2 models on square lattice, which are like the antiferromagnetic J1J_1-J2J_2 model with some additional four-spin exchange interactions. These models admit an exactly solvable case in which the ground state consists of four degenerate columnar-dimer singlet (CDS) configurations. Away from the exact case, we employ bond-operator mean-field theory to investigate the evolution of the ground state by varying the interaction parameters. The mean-field calculation reveals a quantum phase diagram in which the CDS phase undergoes a continuous phase transition to either N\'eel or collinear ordered antiferromagnetic phases.Comment: revtex4, 16 eps files; total 10 pages; accepted for publication in Phys. Rev.

    Effect of Addition of Treated Coir Fibres on the Compression Behaviour of Clay

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    This paper presents the effect of treated coir fibres (15 mm in length) on the unconfined compressive strength of clay. Dry, sodium hydroxide and carbon tetrachloride–treated coir fibres were used in the study. The coir fibre content was varied from 0.4% to 1.6%. The results indicated that the unconfined compressive strength of clay and clay with dry coir fibres can be increased by treatment with carbon tetrachloride and sodium hydroxide. The increase in unconfined compressive strength was highest with carbon tetrachloride treatment. The clay reinforced with treated fibres was able to bear higher strains at failure as compared to clay and clay with dry fibres. With the increase in coir fibre content (0.4%-1.6%) in clay, there was an increase in the unconfined compressive strength. The clay with treated coir fibres can be used for making bricks for mud houses in rural India

    Click chemistry inspired one-pot synthesis of 1,4-disubstituted 1,2,3-triazoles and their Src kinase inhibitory activity

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    Two classes of 1,4-disubstituted 1,2,3-triazoles were synthesized using one-pot reaction of α-tosyloxy ketones/α-halo ketones, sodium azide, and terminal alkynes in the presence of aq PEG (1:1, v/v) using the click chemistry approach and evaluated for Src kinase inhibitory activity. Structure–activity relationship analysis demonstrated that insertion of C6H5– and 4-CH3C6H4– at position 4 for both classes and less bulkier aromatic group at position 1 in class 1 contribute critically to the modest Src inhibition activity (IC50 = 32–43 μM) of 1,4-disubstituted 1,2,3-triazoles. [Refer to PDF for graphical abstract

    Common effluent treatment plant (CETP): Reliability analysis and performance evaluation

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    Common effluent treatment plants (CETPs) have been installed and are in operation at numerous industrial clusters throughout India. They serve to reduce effluent treatment cost, provide better collective treatment, and reduce land cost for small-scale industrial facilities that cannot afford individual treatment plants. Optimum working conditions for treatment of effluent to be at par with discharge standards is a major mandate for any CETP. In this study, the reliability and removal efficiencies (REs) of a CETP in the industrial area of Maharashtra State in India were examined. An established methodology was adopted to determine the effectiveness of the CETP in terms of biochemical oxygen demand (BOD), chemical oxygen demand (COD), total suspended solids (TSS), and oil and grease (O&G) concentrations. The CETP’s compliance with respect to design standards and its operation were studied in detail. This paper highlights the results of RE and the coefficient of determination (R2) values obtained from the CETP data, estimates the pollutants removed at the highest and lowest rates over a period of time, and highlights the reasons for problem areas along with remedial measures. It was observed that, except O&G, all the parameters (BOD, COD, and TSS) showed fluctuations in removal efficiencies and their reliabilities. This situation can be improved by releasing effluent containing hydraulic and organic loading to the CETP as per standards and optimizing treatment processes, especially primary clari-flocculators and aeration tanks, both of which are important units of any CETP

    A REVIEW ON CONCOURSE APPROACH OF DISEASE PREVENTION, HEALTH PRESERVATION AND HEALTH PROMOTION W.S.R TO DINACHARIYA

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    “Prevention is better than cure†is conventional adages. Primordial and primary prevention is best, cost effective and devoid of mental and physical suffering. Data shows that hospitalized Indian spends on an average 58% of their total annual expenditure and over 40% of hospitalized Indians borrow heavily to cover expenses-huge lose in the form of money and manpower. Much has been said and written about disease prevention and health promotion in recent year. But far ago disease prevention and health promotion was traced in Ayurveda also and several measures are mentioned for this purpose. Swasthavritta is the branch of Ayurveda which embraces all the factors, helps to maintain the health and to prevent the disease; it includes Dinachariya (Daily Regimen), Rituchariya (Seasonal Regimen), Ratrichariya (Night Regimen), Sadvritta (Codes and Conducts of Life) etc. All these are nothing but related with sanitation, rules regarding diet, physical activity etc. History shows that life expectancy was increased significantly by only maintaining strict hygiene and proper diet far before the invention of modern medicine. The activity and diet, which were practiced to prevent the disease and to maintain and promote the health during ancient time are still in practice to some extent and as a result the incidences of non-communicable disease are comparatively less in India still now. Hare an attempt has been made to analyse and concourse those procedures responsible for disease prevention, health maintenance and health promotion mentioned in Ayurveda classics with the procedures of modern medicine which serves the same purpose

    Effect of Teetering Pulp Density in Floatex Density Separator - A Case Study

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    The combination of gravity separators like air/wind/wet tables and spirals were used in multistages for the separation of heavier minerals such as monazite, zircon etc. from other minerals such as sillimanite, quartz etc. The introduction of modified commercially available hind-ered settling separators, like floated density/cross flow separators have revolutionized the separation techniques and simplified the earlier complicated process flow sheet. This paper deals with the use of such equipments and some experimental results on separation of fine sillimanite and quartz from the zircon rich fraction which was difficult to separate using conventional gravity concentrators
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