Characteristics of Different Systems for the Solar Drying of Crops

Solar dryers are used to enable the preservation of agricultural crops, food processing industries for dehydration of fruits and vegetables, fish and meat drying, dairy industries for production of milk powder, seasoning of wood and timber, textile industries for drying of textile materials. The fundamental concepts and contexts of their use to dry crops is discussed in the chapter. It is shown that solar drying is the outcome of complex interactions particular between the intensity and duration of solar energy, the prevailing ambient relative humidity and temperature, the characteristics of the particular crop and its pre-preparation and the design and operation of the solar dryer

A combined experimental and modelling investigations on mixed bioligand complexes of divalent cobalt and copper in β

The biologically active divalent metal complexes [Co(II)(GluArg)(H2O)2] (1) and [Cu(II)(GluArg)] (2) (where Co = cobalt and Cu = copper) of mixed glutamic (Glu) and l‐arginine (Arg) amino acids form a stable 1:1 inclusion complex with β‐cyclodextrin (β‐CD) in water. The preferred orientation of guest molecules into the host is simulated by quantum chemical computations. Geometry‐optimized results using ONIOM technique identified the structure and show that the glutamic acid chelate moiety of both metal ions complexes is encapsulated within the β‐CD cavity while the l‐arginine chelate is partially located outside the cavity. The calculated inclusion binding energy (ΔEB, kJ mol−1) and other thermodynamic parameters reveal the noticeable thermal stability of 2‐(β‐CD) over the 1‐(β‐CD) capsulate. A reverse trend is experimentally found from the determined association constant values (K, m−1). The chemical reactivity and reactive site selectivity of these complexes were elucidated via conceptual density functional theory and an electrostatic potential surface map. Global electronic molecular descriptors [such as chemical potential (μ), hardness (η) and electrophilicity (ω)] validated the experimental findings. The reactivity of the encapsulated complexes is altered vis‐à‐vis the free complexes. The obtained results and contradictions are discussed and rationalized. Biologically active divalent Co and Cu complexes of mixed glutamic and l‐arginine amino acids form stable 1:1 inclusion complex with β‐cyclodextrin (CD) in water. The preferred orientation of guest molecules into the host is simulated using ONIOM technique. Computed thermodynamic parameters contradict the experimental results. Electronic factors elucidated via conceptual density functional theory such as reactivity indices and the electrostatic potential surface map validated the experimental findings. The reactivity of the encapsulated complexes is altered vis‐à‐vis the free complexes