Seawater desalination has been studied with interest due to the scarcity of fresh water for human consumption. Solar distillation is an old method; the productivity, energy consumption of the process and the cost of the desalinated water thus obtained depend on the efficiency achieved in each of the stages of these systems. The limited capacity to absorb solar radiation and transform it into useful heat for evaporation, interaction with the surrounding medium, and heat losses restrict the overall efficiency of the thermal process and productivity. Since the energy comes from solar radiation, the maximum productivity of this process will be constrained by the magnitude of the total solar radiation available in an area of the planet due to its geographic location, time of year and local climatic conditions. The processes of this energy will be thermodynamically limited by the heat transfer coefficients achieved in the equipment, the maximum value that the evaporation heat can reach, as long as the losses to the environment by convection and radiation are minimal. Comparative analyses of several proposed models, reported data of distillers, reported data of solar radiation that reach average values of up to 7.2–7.4 kwh/m2 in some regions of the planet are presented and estimates are made for productivity of these equipments that they reach between 6.7 and 6.9 kg/m2 day with a theoretical maximum efficiency of about 0.16 of the total solar radiation.
Based on the density-functional theory (DFT) combined with nonequilibrium Green’s function (NGF), this paper investigates the effects of either single aluminum (Al) or single phosphorus (P) atom substitutions at different edge positions of zigzag-edged silicene nanoribbons (ZGNRs) in the ferromagnetic state on the spin-dependent transport properties and spin thermoelectric effects. It has been found that the spin polarization at the Fermi level can reach 100% or –100% in the doped ZSiNRs. Meanwhile, the spin-up Seebeck effect (for –100% case) and spin-down Seebeck effect (for 100% case) are also enhanced. Moreover, the spin Seebeck coefficient is much larger than the corresponding charge Seebeck coefficient at a special doping position and electron energy. Therefore, the study shows that the Al or P doped ZSiNRs can be used to prepare the ideal thermospin devices.
One of Indonesia’s main characteristics of tourism development is maritime tourism, which is synonymous with archipelagic countries. The diversity of maritime tourism offered by Indonesia will never end, so it needs to be considered more carefully and used relevantly to create sustainable tourism in Indonesia that provides broad benefits for the country. Many maritime tourism locations in Indonesia are beautiful but require more active promotion. The level of security and terrorism issues are a requirement that the government must consider. The novelty of this research describes the potential ecotourism development in the town of Makassar that stakeholders should consider in the formation of tourism policy. The research locations are in Makassar City, Samalona Island, Langkai Island, and Lanjukang Island. Ecotourism developed in the coastal areas of Makassar City, especially in Samalona, Lanjukang, and Langkai Islands, produces superior objects that collaborate elements of nature and society as the main attraction in the long term. Therefore, local governments need to strengthen monitoring of regional geopolitical developments in order to avoid security and terrorism problems that might cause inconvenience to tourists.
Dormancy is a state of lack of germination/sprouting in seed/tuber although required conditions (temperature, humidity, oxygen and light) are provided. Dormancy is based on hard seed coat dormancy or lack of supply and activity of enzymes (internal dormancy) necessary for germination/sprouting. Dormancy is an important factor limiting production in many field crops. Several physical and chemical pretreatments to production material (seed/tuber) are carried out for overcoming dormancy. Physical and physiological dormancy can be found together in some plants and this event makes it difficult to provide high frequency healthy seedling growth. Whereas, emerging of all production material (seed, tuber) sown/planted and forming healthy seedling are prerequisites of plant production.
Under the background of new curriculum reform, the purpose of secondary education and cultivation has been changed to cultivate students' comprehensive and professional abilities. Applying lifelike teaching to the English classroom of secondary education arts and sports students is an effective means to stimulate students' learning interests and improve their English proficiency. Based on the analysis of the current situation of English teaching for arts and physical education students in secondary education, the article puts forward several strategies of English lifelike teaching in order to better improve the English quality of students in secondary institutions and promote the development of English education in secondary institutions.
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