The in ̄uence of soil exchangeable cations and aluminium content on the distribution of various terrestrial gastropods was investigated. Calcium was the most important factor, though aluminium and magnesium content also had some effect. Potassium and sodium had no signi®cant in ̄uence on distribution. The species most sensitive to the factors analysed were Cochlicopa lubrica, Vertigo pygmaea and ...

T he issue of calcium (Ca) availability in alkaline, mineral soils has long been a matter of contention. Based on the commonly used ‘exchangeable cations’ test (ammonium acetate extraction), most Western soils are well supplied with Ca. However, in alkaline soils, a substantial percentage of ‘exchangeable’ calcium identified by this test can be in chemical forms not readily available to plants ...

Sequential leaches (sequential extractions) experiment of 62 elements were carried out for assessing the mobility of contaminated heavy metals and metalloids contaminated in natural sediments; river sediments of Oued El Harrach (Algeria) and lagoon sediments of Bizerte (Tunisia), North African Mediterranean coast. Applied extractants for the sequential leaches are: (A) distilled water for extra...

The catalytic Diels-Alder cycloaddition-dehydration (DACD) reaction of furanics with ethylene is a promising route to bio-derived aromatics. The reaction can be catalyzed by alkali-metal-exchanged faujasites. Herein, the results of periodic DFT calculations based on accurate structural models of alkali-metal-exchanged zeolites are presented, revealing the fundamental roles that confinement and ...

Cation-exchangeable d(0) layered perovskites are amenable to intercalation, exfoliation, and a variety of topochemical reactions, but they lack the interesting electronic and magnetic functionalities of mixed-valent perovskites. Conversely, electronically and magnetically interesting layered perovskites lack scope in terms of interlayer chemistry. To bridge this gap, the insulating, cation-exch...

The proportion of acidic purple soils has increased. Consequently, an effective method for amelioration is urgently needed. A 40 day incubation experiment using apple tree biochar, fermented sheep manure and chicken was conducted to assess the effects organic materials on acidity fertility soil. results showed that application increased soil pH decreased soil-exchangeable acidity. All treatment...