Reproducibility and long-term stability of Sn doped MnO2 nanostructures: Practical photocatalytic systems and wastewater treatment applications

Sn-doped MnO₂ were synthesized as an oxidant, a mediator of maleic acid (C₄H₄O₄) and SnCl₂ as doping ingredient via a basic sol-gel reaction with KMnO₄. XRD study signposts that tetragonal crystal structure of MnO₂ (ICDD#44-0141) with a plane group of 12/m (87) for both pure and Sn doped MnO₂ nanostructures. The photocatalyst synthesized has mesoporosity, allowing to the N₂ adsorption/desorption experiments. The geometry of the materials varies from spherical shape in pristine MnO₂ to a rod-like shape in Sn-MnO₂, as observed in the SEM and TEM pictures. To examine optic properties and energy bandgaps topologies, UV-visible diffuse reflectance spectroscopy was applied. In visible spectrum, overall catalytic performance of Sn-doped MnO₂ was tested using methyl orange and phenol as dyes. The results suggest that the optimized Sn doped MnO₂ (10 wt.%) catalyst showed higher degradation efficiency (98.5%), apparent constant (0.7841 min^-1) and long term permanence. For this improved charge extraction efficiency, a potential photocatalytic mechanism was proposed.

Effect of Gibberellic Acid and Indole 3-Acetic Acid on Seed Germination Performance of Horse gram (Macrotyloma uniflorum) Lam (Verdc)

The experiment was undertaken with an objective to investigate the effect of various concentrations of plant growth regulators, i.e., Gibberellic acid (GA3) and Indole 3-acetic acid (IAA) on seed germination of Macrotyloma uniflorum. Seeds were soaked for 12 hours in different concentrations substances (1.0, 2.0, 3.0 and 4.0 mg/L) of IAA, GA3 and control set was soaked only in distilled water.  Three replicates of each treatment with fifty seeds per replicate were arranged for precise physiological analysis. Significant variation was found in all aspects after analysis of variance (ANOVA) of each mean value. After two weeks of seed soaking, it was noted that germination percentages were significantly accelerated by lower concentrations (1 and 2 mg) of used hormones. Amongst the two potential growth regulators, 2 mg/L was found most effective because it showed highest germination percentage for IAA (93%) and GA3 (88%). A great deal of information relating to seed germination practices shows that these plant growth regulators were efficient in overcoming dormancy leading to rapid seed germination. IAA was selected as best hormone in this study, which showed highest seed germination (93%). 

Evaluation of shear bond strength between zirconia core and ceramic veneers fabricated by pressing and layering techniques: In vitro study

Statement of Problem:

Although ceramic veneered on to zirconia core have been in use for quite some time, information regarding the comparative evaluation of the Shear bond strength of Pressable & Layered ceramic veneered on to zirconia core is limited.

Purpose of study:

To evaluate the shear bond strength of zirconia core and ceramic veneer fabricated by two different techniques, Layering (Noritake CZR) and Pressing (Noritake, CZR Press).

Materials and Method:

20 samples of zirconia blocks were fabricated and the samples were divided into group A & B. Group A - Ceramic Veneered over zirconia core by pressing using Noritake CZR Press. Group B - Ceramic Veneered over zirconia core by layering using Noritake CZR. The veneered specimens were mounted on to the center of a PVC tube using self-cure acrylic resin leaving 3 mm of the veneered surface exposed as cantilever. Using a Universal testing machine the blocks were loaded up to failure.

Result:

The results were tabulated by using independent samples t-test. The mean shear bond strength for Pressed specimens was 12.458 ± 1.63(S.D) MPa and for layered specimens was 8.458 ± 0.845(S.D) MPa.

Conclusion:

Pressed specimens performed significantly better than the layered specimen with a P value 0.001. Clinicians and dental laboratory technicians should consider the use of pressed ceramics as an alternative to traditional layering procedures to reduce the chances of chipping or de-lamination of ceramics

Influence of GA₃ and IAA and their Frequency of Application on Seed Germination and Seedling Quality Characters

Effect of plant growth regulators on seed germination and seedling characters in terms of root length and shoot length. The seeds of sesame variety TVM – 1 were treated with different concentration of gibberlic acid (1.0, 2.0, 3.0 and 4.0 mg/l) and indole acetic acid (1.0, 2.0, 3.0 and 4.0 mg/l). From the results, it was observed that the GA3 and IAA at 2.0mg/l had regulatory effect on seed germination and seedling characters. Maximum germination, root length and shoot length was observed at 2.0mg/l in GA3 and 2.0mg/l in IAA than control. And GA3 at 2.0gm/l was found to be more efficient to modify seed germination and seedling characters when compared to IAA and control.

Intra and extra erythrocyte lithium ion concentration ratios in manic patients

In a study RBC-Plasma lithium ratios in manic patients treated with lithium we found that lithium responders had higher lithium ratios than lithium non-responders. There was, however, no cut off value which could differentiate lithium responders from non-responders.