ABSTRACT
The effect of different ionic crosslinking parameters on the thickness, radiometric profiles, and mechanical and water vapor permeation (WVP) properties of alginate mulching films was investigated. Crosslinking by Mn(2+), Zn(2+), and Ca(2+) (but not Al(3+)) increased the tensile strength and light transmission and decreased the WVP of the films. Among the films, those crosslinked by Ca(2+) had the greatest tensile strength and exhibited the highest elongation and light transmission. Furthermore, the WVP and light transmission decreased gradually with increasing Ca(2+) concentration, and the maximum tensile strength and elongation were obtained for 2% (w/v) of Ca(2+). However, the WVP of the films increased gradually with increasing crosslinking time, and the elongation saturated after 2 min. These results suggest that alginate films crosslinked by 2% (w/v) calcium chloride for 2 min had the best overall performance and therefore have the potential to be used as entirely biodegradable agricultural mulching films.
Subject(s)
Agriculture , Alginates/chemistry , Cations, Divalent/chemistry , Physical Phenomena , Tensile Strength , Glucuronic Acid/chemistry , Hexuronic Acids/chemistry , Light , Permeability , Radiometry , Volatilization , Water/chemistryABSTRACT
Objective To learn the present hospital management conditions in Shanghai for upgrading quality of care.Methods The stratified sampling method was used for a questionnaire survey of the quality of care at 20 hospitals in Shanghai (10 tertiary hospitals and 10 secondary hospitals).The survey covered such six dimensions as organizational framework,management functions,management tools,professional training,regulations and norms,and supervision over operations.Results Medical quality management system is established at such hospitals and all of them have established medical quality management committees.Rooms of improvement remain in such details as departmental quality management,regulations standardization,IT support,and management tools popularity.Conclusion Management regulations and standards of medical quality management should be improved and implemented from both external and internal aspects,to improve medical quality and patient safety.
