52 research outputs found

    Predicting Compressive Strength of Recycled Aggregate Concrete using Analysis of Variance

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    A step-by-step statistical approach is proposed to obtain optimum proportioning of concrete mixtures using the data obtained through a statistically planned experimental program. The utility of the proposed approach for optimizing the design of concrete mixture is illustrated considering a typical case in which trial mixtures were considered according to a full factorial experiment design involving three factors and their three levels. A total of 27 concrete mixtures with three replicates were considered by varying the levels of key factors affecting compressive strength of concrete, namely, w/c ratio, recycled coarse /natural coarse aggregate ratio, and recycled fine/ natural fine aggregate ratio .The experimental data were utilized to carry out analysis of variance (ANOVA) and to develop a polynomial regression model for compressive strength in terms of the three design factors considered in this study. The developed statistical model was used to show how optimization of concrete mixtures can be carried out with different possible options

    Comparative Evaluation of Azadirachta indica (Neem) Chip and Soft Tissue Diode Lasers as a Supplement to Phase i Periodontal Therapy in Localized Chronic Moderate Periodontitis: A Randomized Controlled Clinical Trial

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    Introduction. The current trial aimed to assess and compare the efficacy of neem chip and diode laser as a local drug delivery (LDD) agent as a supplement to phase I periodontal therapy in treatment of localized chronic moderate periodontitis. Materials and Methodology. Fourteen systemically healthy participants with 4-6 mm deep periodontal pockets at least in three quadrants (with no alveolar bony defect amenable to respective or regenerative osseous surgery, as seen in orthopantomograph) were selected for the trial. One week after phase I therapy, 10% absorbable chip of neem (commercially prepared by staff of a pharmacy college, Sheriguda, India) was placed in the periodontal pocket on one site, and soft tissue diode laser pocket sterilization was performed on the other site of the arch. Remaining one site was considered as a control. Parameters recorded clinically were plaque index (PI), papillary bleeding index (PBI), probing pocket depth (PPD), and relative attachment level (RAL) measured at baseline, 21st day, and one month postoperatively. Results. Statistically significant improvements were observed in all clinical parameters at one month as compared to baseline for both treatment groups. Conclusion. Neem chip supplemented with phase I therapy showed best improvement in clinical parameters followed by laser supplemented with phase I therapy in comparison to phase I therapy alone at one month follow-up. Clinical Significance. Neem chips are nature's products, affordable without side effects, with a potential to be used as a local drug delivery agent in treating moderate chronic periodontitis

    Experimental Study of CO2 Gasification of Biomethanation Waste

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    Gasification is one of prominent thermochemical processes generally used to convert organic feedstock to combustible syngas (CO and H2). An experimental study of biomass gasification using carbon dioxide as an gasifying medium was carried out in a fixed bed gasifier. The main aim of this study was to determine the effect of temperature on the output syngas. The present study reported the results for producing syngas with CO2 as gasification agent and biomass (rice husk and bio-methanation waste) as raw material. The gasification was performed at 700-900°C respectively and CO2 flow rate was maintained at 0.5 lpm. Maximum syngas production found at high temperature (900°C). The syngas analysis showed higher hydrogen yield at higher temperatures

    Hybrid suspension/solution precursor plasma spraying of a complex Ba(Mg1/3Ta2/3)O3 perovskite: Effects of processing parameters and precursor chemistry on phase formation and decomposition

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    Abstract: Ba(Mg1/3Ta2/3)O3 (BMT) has a high melting point and is envisioned as a thermal barrier coating material. In this study, a hybrid suspension/solution precursor plasma spray process with a radio frequency thermal plasma torch is designed to deposit BMT nanostructured coatings. Six combinations of chemical reagents are investigated as coating precursors: one BMT powder suspension and five Ta2O5 suspensions in nitrate- or acetate-based solutions. X-ray photoelectron spectroscopy is used to evaluate the element evaporation during plasma spraying, while a thermogravimetric/differential thermal analysis is applied to investigate the BMT formation. Parameters such as precursor chemistry, plasma power, spraying distance and substrate preheating are studied with regard to the coating phase structure. Twice the Mg stoichiometric amount with a power of 50 kW shows the best results when using nanocrystallized Ta2O5 as a tantalum precursor. When choosing nitrates as Ba and Mg precursors, crystallized BMT is obtained at lower plasma power (45 kW) when compared to acetates (50 kW). BaTa2O6, Ba3Ta5O15, Ba4Ta2O9, Mg4Ta2O9 are the main secondary phases observed during the BMT coatings deposition. Because of the complicated acetate decomposition process, the coating deposition rate from nitrate precursors is 1.56 times higher than that from acetate precursors

    Alternative mechanisms of drop breakup in stirred vessels

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    Kumar et al. (1991, Chem. Engng Sci. 46, 2483-2489) have shown that in a stirred vessel, size of the largest stable drop, dmax, first increases with φ (holdup of the dispersed phase) at low φ, but decreases with φ at high φ. They have proposed two additional mechanisms of breakage-in shear and elongational flow regions in the front of the impeller blade-that operate along with the hitherto accepted mechanism due to turbulent fluctuations, and conclude that dmax at high φ is controlled by breakage in shear flows in the range of parameters investigated by them. We show in this paper that their model is deficient on various counts. The new model proposed here overcomes these deficiencies. It predicts that at high φ, dmax is controlled by breakage in the accelerating flow in the tip region of a rotating blade. The model predicts the data of Kumar et al. (1991) and Boye et al. (1996, Chem. Engng Commun. 143, 149-167). New experiments were also conducted to discriminate between the two proposed mechanisms. The experiments independently confirm that drop breakage at high φ is indeed controlled by accelerating flow. The model could predict the new experimental data also quite well

    Apoptosis: Molecular mechanism

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    Cell death is one of the essential processes. Balance between cell division and cell death is of utmost importance for the development and maintenance of multi-cellular organism. Disorders of either process have pathologic consequences and can lead to disturbed embryogenesis, neurodegerative diseases, or the development of cancers. This article reviews the apoptotic as well as anti-apoptotic molecules along with molecular pathways, which may alter in many diseases

    climate change risk management through Three- stage Intercropping system cotton:sorghum:pigeonpea:sorghum(3:1:1:1)(Marathi Version)

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    Not Availableजलवायु परिवर्तन जोखीम व्यवस्थापनासाठी त्रिस्तरीय आंतरपीक पध्दत कापुस : ज्वार : तुर : ज्वार(३:१:१:१)Not Availabl

    Three stage intercropping system for dryland agriculture. Cotton : soybean : pigeonpea : soybean (3:2:2:2)[Marathi Version]

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    Not Availableकोरडवाहू शेतीसाठी त्रिस्तरीय आंहरपीक पध्दत कापुस : सोयाबीन : तुर : सोयाबीनNot Availabl
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