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Climate change is one of the main socio-environmental challenges of the current 21st century. The objective of this research is to analyze the contents about climate change proposed in the textbooks of Primary Education of Social Sciences (3rd cycle) in the Valencian Community (Spain) attending to: 1) the explanation of the phenomenon (causes and consequences); and 2) the description of the main greenhouse emissions. The results indicate that currently, textbooks project an excessively catastrophic image of climate change (increase in extreme atmospheric phenomena) and citing as error carbon dioxide (CO2) as the main effect gas greenhouse. In conclusion, the textbooks do not provide rigorous content and information from scientific papers and academic sources and the presence of stereotypes about climate change (natural disasters) is abused. [ABSTRACT FROM AUTHOR]

This paper presents a study about the importance of residence time, also called permanence time, of a gas in a gap of dielectric barrier discharge, for the treatment of carbon dioxide CO2, which is a pollutant gas. Along with CO2, hydrogen H2 is added to form the atmosphere of the discharge reaction. It was studied the behavior of power deliver to system as a function of operation voltage using alumina and quartz as dielectrics. CO2 conversion was studied as a function of residence time for three different compositions of the CO2 + H2 mixture, for three different values of the active electrical power supplied to the system and for three different values of frequency of operation using alumina as dielectric. The percent conversion of CO2 in fixed working conditions was increased with increasing residence time, regardless of the composition of the mixture of the two gases, of the electrical power and the operation frequency, finding the highest values for the least amount of CO2 in the mixture, for higher power delivered and for the lower frequency of operation. [ABSTRACT FROM AUTHOR]

Electric motors are the main producers of industry motive power. They are machines that work with a relatively high efficiency, however, their oversizing for various reasons causes them to work occasionally with low efficiency. For this reason, the replacement of oversized induction motors is considered as an opportunity to save energy. However, it is necessary to verify that its oversizing is not necessary, since in high inertia loads case a higher power motor may be required to satisfy the starting requirements. In this paper, the analysis of replacement of oversized motors by others of lower power and higher efficiency class is carried out. The dynamic starting regime is analyzed and potential for economic savings and reduction of CO2 emissions are evaluated. The Steam Generation area of the UEB Central Azucarero 14 de Julio is taken as a study case. [ABSTRACT FROM AUTHOR]

In this paper an innovative focus to programming Job Shop systems, based on sustainability, is presented. The following sustainability variables are evaluated: carbon dioxide emissions (environmental variable), sound intensity, accident rate and handled weight (social variables: occupational health) and finally, makespan time and direct labor costs (economic variables). The methodology is structured in fourteen steps that cover aspects such as multiobjective method design, description of genetic algorithms, and comparison with other methods. It is determined that the designed method shows greater performance for the variable weighted factor P(Xj) when they are compared with results from other methods such as programming rules and mobile bottle neck method. [ABSTRACT FROM AUTHOR]

The current study proposed an experimental investigation into the basic characteristics of solar thermal conversion using supercritical CO2-dimethyl ether (DME) natural convection. The main goals are to reduce the operation pressure while maintaining relative high solar thermal conversion efficiency. Experimental systems were established and tested in Shaoxing area (around N 30.0 deg, E 120.6 deg) of Zhejiang Province, China. Due to the preferable properties of supercritical fluids, very high Reynolds number natural convective flow can be achieved. Typical summer day results are presented and analyzed into detail in this paper. It is found that the introduction of DME has successfully reduced the operation pressure and the increase in DME fraction leads to further reduction. Different from pure supercritical CO2 systems, the collector pressure follows the trend of solar radiation with its peak value at noon, instead of continuously increasing mode. The mass flow rate and temperature are typically more stable and also more sensitive than pure supercritical CO2 tests due to the moderation of supercritical fluid properties when DME is introduced. At the same time, the averaged collector efficiency is less affected by the DME mass addition. It is also found that there possibly exist some optimal of DME mass fraction when both the system suitability and stable natural circulation can be achieved. [ABSTRACT FROM AUTHOR]

The acid compounds (H2S y CO2) removal from gaseous streams is traditionally carried out in an absorption system based on alkanolamines. The present paper deals with the evaluation of a gas sweetening plant for the H2S removal from hidrotreating products in a heavy oil industry. The efficiency of a typical absorption system running on MDEA/MEA and MDEA/DEA is proved to obtain a lean gas with 40 to 60ppm of H2S. The 90% of the H2S is recovered and the sweet gas can be recirculated to the hidrotreating stage. The modeling and simulation of the process is implemented on Aspen-Hysys software. [ABSTRACT FROM AUTHOR]

This paper presents a detailed calculation of the environmental benefit associated to the use of sugar cane for the production of fuel ethanol in a diversified ethanol distillery that is devised to operate as an agroindustry. From the consideration of the several stages of the production process such as biomass production, transportation of cane from the field to the factory, ethanol production, bagasse combustion, anaerobic digestion of vinasses and combustion of generated methane, and combustion of ethanol in automotive vehicles, it is shown that the use of sugar cane is environmentally beneficial because it involves the removal of 22,639 ton / year of CO2 from the atmosphere and the incorporation of 15,244 ton / year of O2 into the atmosphere, for a distillery with a production capacity of 40,000 L / day of fuel ethanol. Also, a calculation is made for the amount of CO2 that would be incorporated into the atmosphere if natural gas were used in the distillery for the generation of electricity by means of a combined power cycle. [ABSTRACT FROM AUTHOR]

Past literature has reported many successful cases about crops in greenhouses. The main function of greenhouses is to recreate and keep adequate and controlled conditions of light, humidity, temperature, carbon dioxide, and pesticides, among others, in a confined space to grow plants for diverse purposes. However, those conditions can be potentially harmful to humans that work in greenhouses. An alternative to overcome this is the application of robotics in those agricultural sites, adequately applying artificial intelligence and mechanical subsystems that are part of a robot. This paper describes a literature review of research and development of robots used in activities such as spraying pesticides and for harvesting in greenhouses. [ABSTRACT FROM AUTHOR]