The popularity created the concept of sustainable development has determined the conviction that tourism can develop in compliance with the philosophy of sustainability.For example, if we compare with other activities such as agriculture, forestry or in other sectors of the economy, tourism has a development relatively recent to human evolution.Tou
Because adolescent leisure is important to development, we consider its role ngetikin in Portuguese adolescent wellbeing.Data for this study came from 303 adolescents in grades 10, 11, and 12 living in a large urban area in northern Portugal.Self-report data were collected in classrooms using a cross-sectional design in two urban high schools.Hypot
In this paper nanostructures Porous silicon layers have been prepared by electrochemical etching (ECE) technique of (111) P-type silicon wafer with a solution Electrolytic HF: ethanol at a concentration of 1:2 with various anodization currents and etching here time of 20 min.The morphological, structural and optical properties of nanostructure poro