Performance of ‘Galia’ melon grown under different soil cation ratios

The northeast region of Brazil stands out in the production and export of melon. In this region, where this crop is mostly grown, part of the soil is of limestone origin, as is the irrigation water used. Over successive cultivations, these conditions can lead to soil alkalinization due to the accumulation of basic cations of the exchange complex, such as Ca, Mg, K and Na, in soils that are already rich in bases, thus influencing nutrient availability and, consequently, crop yield. On this basis, this study was developed to identify the cation ratios (K:Mg:Ca) of the soil that best correlate with attributes indicative of ‘Gália’ melon production. Two experiments were carried out in two consecutive years (2017 and 2018), in a randomized-block design with five treatments and five replicates. Treatments consisted of the following cation ratios (K:Mg:Ca) for experiment I, whose soil had a K content of 0.40 cmolc dm-3: T1 (1:3:34), T2 (1:3:21), T3 (1:3:9), T4 (1:0.8:9) and T5 (1:11:34); and experiment II, where the soil had 0.56 cmolc dm-3 of K: T1 (1:1.6:29.8), T2 (1:1.4:13.3), T3 (1:1.4:8.5), T4 (1:0.5:8.5) and T5 (1:4.8:29.8). The following traits were evaluated: chemical analyses of the soil during the flowering phase and at the end of the cycle, nutrient concentration in the diagnostic leaf during the fruiting phase, total yield, marketable yield, average total weight, average marketable weight, total number of fruits and number of marketable fruits per plant. The cation ratios influenced the average total and marketable fruit weights only in experiment I, but not yield. Therefore, when associated with irrigation water from the Açu sandstone aquifer and fertigation, the high absolute K and medium to high Mg contents are sufficient to meet the K and Mg nutrient requirements, dispensing with correction of the cation ratio.

Chloride binding capacity of LDHs with various divalent cations and divalent to trivalent cation ratios in different solutions

Chlorides were bonded by LDHs due to ion exchange and surface adsorption. Carbonation resulted in the debonding of the chloride bond by ion exchange, however, surface adsorption was not affected by carbonation.

Developments in SiAlON Glasses and their Derivatives: Effects of Chemistry on Properties

This paper provides an overview of the preparation of M-Si-Al-O-N glasses and outlines the effects of composition on properties. As nitrogen substitutes for oxygen in sialon glasses, increases are observed in glass transition and softening temperatures, viscosities, elastic moduli and microhardness. If changes are made to the cation ratios or different rare earth elements are substituted, properties can be modified. The effects of these changes on mechanical properties of silicon nitride based ceramics and sialons are discussed. New research on M-Si-Al-O-N-F glasses is outlined.

Wechselwirkungen in Molekülkristallen, 157 [1, 2]. Mischkristallzüchtung und Strukturbestimmungen von Tetra(3,4-dimethylphenyl)-imidodiphosphat-Salzen mit Alkalikation- Verhältnissen K⊕/Rb⊕(1:5) und Rb⊕/Cs⊕(1:1) / Interaction in Molecular Crystals, 157 [1, 2]. Mixed Crystal Growth and Structure Determinations of Tetrakis(3,4-dimethylphenyl)-imidodiphosphate Salts with Alkali Cation Ratios K⊕/Rb⊕ (1:5) and Rb⊕/Cs⊕ (1:1)

Mixed crystals of tetrakis(3,4-dimethylphenyl)imidodiphosphate salts with alkalication ratios K⊕/Rb⊕ (1:5) and Rb⊕/Cs⊕ (1:1), (1:3) as well as (3:1) have been grown by suspending finely ground stoichiometric mixtures of alkali carbonates in toluene solutions of the strongly chelating ligand HN(PO(OR)2)2 - The cation ratios were measured by Total Reflexion X-Ray Fluorescence (TXRF) analysis and the single crystal structures of the polymeric K⊕/Rb⊕ as well as the Rb⊕/Cs⊕ imidodiphosphate salts determined by X-ray structure analysis. The selectivity of the various alkali ions for insertion in the crystal lattices of the individual imidodiphosphate salts has been confirmed by concentration-dependent crystallizations and discussed based on the structural analysis of the differing ligand conformations. The unit cell parameter dependence on the alkali cation radii provided information on van der Waals interactions between adjacent phenyl rings of the imidodiphosphate ligands and suggests the selective alkali cation insertion to be partly due to supramolecular repulsion within the lipophilic phenyl skin during the selfaggregation of the polymeric salt chains