Selective synthesis of scheelite/perovskite CdWO4 nanoparticles: a mechanistic investigation of phase formation and property correlation

We proposed a simple solution combustion strategy to fabricate CdWO4 nanoparticles for the first time in two different polymorphs: a stable monoclinic and metastable tetragonal phase. The selective synthesis of polymorphs has been achieved by optimizing oxidizer to fuel ratio. Influence of oxidizer to fuel ratio on the formation of CdWO4 polymorphs is of particular relevance to this study and the significant effects are discussed. A mechanistic comparison of properties between two phases has been carried out. Rietveld analyzes of powder X-ray diffraction patterns were performed using GSAS program. Transmission electron microscope images of as synthesized products show the particle sizes of t-CdWO4 (10–20 nm) are smaller than the particle size of m-CdWO4 (≈30 nm). The specific surface area was found to be 12 and 25 m²/g for tetragonal and monoclinic phases, respectively. Photocatalytic activities were investigated by the degradation of methylene blue solution under UV light irradiation. It was found that the photocatalytic activity of tetragonal phase was higher than monoclinic phase, this can be attributed to smaller particle size and active sites of the catalyst that rely sensitively on synthetic conditions. We also explored the photoluminescence (PL) properties of t-CdWO4 and compared with the PL results of m-CdWO4

Preliminary screening of cardamom (Elettaria cardamomum Maton) elite clones for thrips (Sciothrips cardamomi Ramk.) damage in the field

Seventy three elite cardamom (Elettaria cardamomum) clones were screened for tolerance to thrips (Sciothrips cardamomi) damage under natural infestation. Three colones, viz., D-514, D-769 and CI-754 were promising with least damage to capsules. &nbsp

Preliminary screening of cardamom (Elettaria cardamomum Maton) elite clones for thrips (Sciothrips cardamomi Ramk.) damage in the field

Seventy three elite cardamom (Elettaria cardamomum) clones were screened for tolerance to thrips (Sciothrips cardamomi) damage under natural infestation. Three colones, viz., D-514, D-769 and CI-754 were promising with least damage to capsules. &nbsp

Preliminary screening of cardamom (Elettaria cardamomum Maton) elite clones for thrips (Sciothrips cardamomi Ramk.) damage in the field

Seventy three elite cardamom (Elettaria cardamomum) clones were screened for tolerance to thrips (Sciothrips cardamomi) damage under natural infestation. Three colones, viz., D-514, D-769 and CI-754 were promising with least damage to capsules. &nbsp

Synthesis, characterization and TL studies of porous CaSiO3 ceramic powders

Nanocryst. porous CaSiO3 ceramic powders have been synthesized by a novel low temp. initiated self-​propagating, gas producing soln. combustion process and characterized by XRD, SEM, EDS (energy dispersive spectroscopy)​, porosity, surface area and thermoluminescence (TL) studies. The effect of temp. on cryst. phase formation, amt. of porogens and particle size of porous CaSiO3 have been investigated. Single phase β-​CaSiO3 and α-​CaSiO3 were formed at 950° and 1200°C resp. The phase transformation temps. of combustion derived CaSiO3 were found to be low compared to the powders obtained via solid state reaction method. The microstructure and morphol. were studied by SEM and it was noted that with increase in calcination temp., the samples became more porous and the pore diam. increased from 0.25 to 8 μm. The samples calcined at 950°C for 3 h had 17.5​% porosity, however, the porosity increased to 31.6​% on calcination at 1200°C for 3 h. The surface areas of the as-​formed and calcined (at 950° and 1200°C) CaSiO3 samples were found to be 31.93, 0.585 and 3.48 m2·g-​1 resp. The TL intensity in powder sample was more intense when compared to the pelletized CaSiO3 and it was further obsd. that there was a shift in glow peak temps. in pelletized sample. This is attributed to the interparticle spacing and pressure-​induced defects

Effect of growth regulators and spacing on multiplication of planting ullits in cardamom (Elettaria cardamomum Maton)

Experiments on multiplication of planting units in cardamom (Elettaria cardamomum) under uniform shade revealed that growth regulators (Etherel 250 ppm and Cycocel 2000 ppm) did not influence proliferation of planting units whereas closer spacing (0.9 m x 0.3 m) resulted in significantly higher number of planting units. &nbsp

Response of cardamom (Elettaria cardamomum Maton) to NPK under uniform shade

Experiments conducted during 1987-94 at Mudigere (Karnataka, India) to study the response of different levels of N, P and K on the yield of cardamom (Elettaria cardamomum) under uniform shade indicated that increasing N up to 100 kg/ha resulted in a significant increase in capsule yield. Application of P at 50 kg/ha had a positive effect on yield; further increase of P up to 100 kg did not give significant results. In the case of K, significant increase in yield was observed up to 100 kg/ha. The effect of NPK levels on yield component factors such as suckers and panicles varied from year to year. &nbsp

Flowering and fruit set in vanilla (Vanilla planifolia Andr.)

Cultivation of vanilla (Vanilla planifolia Andr.) is becoming increasingly popular in recent years in the hill zone of Karnataka, India. &nbsp

Iridium-doping as a strategy to realize visible light absorption and p-type behavior in BaTiO3

BaTiO3 is typically a strong n-type material with tuneable optoelectronic properties via doping and controlling the synthesis conditions. It has a wide band gap that can only harness the ultraviolet region of the solar spectrum. Despite significant progress, achieving visible-light absorbing BTO with tuneable carrier concentration has been challenging, a crucial requirement for many applications. In this work, a p-type BTO with visible-light absorption is realized via iridium doping. Detailed analysis using advanced spectroscopy tools and computational electronic structure analysis is used to rationalize the n- to p-type transition after Ir doping. Results offered mechanistic insight into the interplay between the dopant site occupancy, the dopant position within the band gap, and the defect chemistry affecting the carrier concentration. A decrease in the Ti3+ donor levels concentration and the mutually correlated oxygen vacancies upon Ir doping is attributed to the p-type behavior. Due to the formation of Ir3+ or Ir4+ in-gap energy levels within the forbidden region, the optical transition can be elicited from or to such levels resulting in visible-light absorption. This newly developed Ir-doped BTO can be a promising p-type perovskite-oxide with imminent applications in solar fuel generation, spintronics and optoelectronics.Comment: 21 pages, 8 figure