Ice slurry is applied in different refrigeration and air conditioning systems, and among its main advantages is the ability to store latent heat and be pumpable as cold water. This fluid can be used for thermal storage instead of cold water or solid ice, since, at certain concentrations, it can be pumped through heat exchangers. For this technology to be widely used, the equipment must be designed considering the heat exchange characteristics. This study developed an experimental system to study the parameters that influence heat exchange, using ice slurry in a plate heat exchanger and water as a thermal load. Several situations with different flows and initial fractions of ice in ice slurry were analyzed. The input conditions of the thermal load were kept constant, the temperature, the pressure drop and the flow of the ice slurry in the heat exchanger were controlled, according to the Nusselt, Prandtl, and Reynolds coefficients. Results show that the global heat exchange coefficient increases with the increase of the initial ice fraction; the cooling capacity of the heat exchanger increases when ice slurry is used as a fluid. For flow rates greater than 0.16 kg/s and ice fractions above 11%, ice crystals are generated at the heat exchanger outlet, due to the ice slurry’s higher viscosity, at approximately 0.003 Pa at the outlet, since the pressure drop increases as the initial ice fraction increases. Results show ice slurry thermohydraulic behavior. Its use shows favorable characteristics in heat exchange.
Corn (Zea Mays) is the most cultivated cereal in the world and this is a staple food for human beings that is why in recent years they are looking for alternatives to improve their production. On the other hand, whey is a residual effluent from the dairy industry generally eliminated in sewage, however, due to its high organic load it can be used to produce different biofertilizers. The objective of this study was to evaluate the effect on the production of the corn crop when applying a biofertilizer obtained by anaerobic fermentation of whey and bovine manure. The study was conducted between October 2018 and February 2019, in the experimental area of the Calaspam association, located in Majes, Arequipa-Peru. A complete randomized block experimental design was used in a 2×4 factorial scheme composed by three biofertilizer treatments (6.9 and 12 LBF/water) and a control treatment with three replicates applied with an average flow rate of 1.5 Lha-1. Morphological, post-harvest and economic indicators were determined, as well as the chlorophyll content. Results indicate that biofertilizer treatments improved the indicators studied. The third treatment shows higher values in all the indicators compared to the other treatments, being the values of yield (79,29±7,33 103 kgha-1) and marginal return rate (85,73%) the most outstanding. It is concluded that the biofertilizer obtained from bovine manure and whey has a positive effect on corn production and its application is economically viable.
Currently, the National Society of Mining, Petroleum and Energy (SNMPE) states that in recent years the production of gold in Peru has reduced, since in 2016 there was a production of 153 MT, compared to 2005 with a production of 208 MT. Until 2018, a production decrease of 5.4% was established and in 2017 a decrease of 11.3%. Currently there is a need to develop research on gold extraction processes in low recovery minerals with traditionally used processes, due to the complex structure of gold that prevents their extraction. It is necessary to evaluate new processes that are environmentally friendly and that are sustainable in the environmental and economic aspects. In the present work, the applicability of leaching with NaCl and KNO3 in acid medium in a sulphurous gold mineral was evaluated, through the process of leaching with oxidizing salts, which allows to process hydrometallurgy the various forms of gold minerals present in nature. The sample is composed in percentages by Quartz 24%, Carbonates Dolomite 22%, Calcite 6%, Arsenopyrite 19%, Pyrite 5%, Galena 4% and clays associated with traces of Native Au-Electrum, which were interfering with the process of leaching of the sample. A pretreatment by gravimetric concentration was carried out using the Falcón equipment, with the aim of releasing the encapsulated gold and eliminating the interfering agents, facilitating the leaching action of the oxidizing salts. When testing the concentrations of the oxidizing salts, it was found that for the concentrations of 86.86 g/l of NaCl, 21.96 g/l of KNO3 and 125.93 g/l of H2SO4, a maximum recovery of 26.62% gold was obtained. Based on the results from the factorial design, an increase in gold extraction performance was observed; obtaining a maximum recovery of 29.31% of the gold; in the process it was determined that dissolved gold is affected by the presence of clays, producing the "Preg-robbing" effect of the valuable metal and consequently decreasing the recovery of gold after 8 leaching hours. According to the results, it is concluded that the leaching process with oxidizing salts in acidic medium for the type of mineral used, is mainly affected by the presence of coarse gold and electrum associated with clays, establishingconditions of degree of release according to the granulometry in the gold leaching process.
Currently, textile dyeing companies determine their market according to the raw materials processed, which are based on 100% cotton fibers, these fibers are directed to an exclusive market and therefore these companies establish criteria of high quality standards in each of its processes, dyeing being one of the most demanding due to its fastness parameters and color specifications, these characteristics establish the competitiveness of expanding a product portfolio with the incursion of 100% fiber-based clothing polyester and with cotton blends.Some studies suggest the implementation of the dyeing process of these fibers, allowing the organization to have new production alternatives, dyeing processes for polyester and cotton are carried out with heat treatment between 60 °C and 130 °C respectively, with the use of dispersed and chemical dyes; as in the dyeing of Polyester-Cotton that are made in bathrooms established in each stage. Color and solidity tests are performed according to quality parameters, with light and wash fastness controls. Within these dyeing conditions it is essential to determine the thermal gradients to be applied, whose variable must be controlled to optimize the dyeing of polyester fibers and mixtures.The present study evaluates the pre-treatments and the temperature gradient behavior stage in the dyeing process of polyester fibers, taking into account the dyeing curve, in which only the temperature gradient varies. Mathis-ALT-B equipment is used for the dyeing process, for thermal gradient conditions of 135 °C with gradients of 0.3-4.0 °C/min, rotation speed 40-70 RPM, and as colorants were used Novacron, Terail and Liandisperse for cotton and polyester fibers respectively. The results show that the use of dispersants and anti-breakage agents work to prevent failures and improve the corresponding colors, but a high gradient increases the migration of the dye and breaks in the fibers, but in low gradients (2 ° C/min ) The quality of diffusion and dyeing is better and, therefore, prevents reprocessing in the dyeing stage. INFORMACIÓN
The Geostatistics provides effective tools for the solution of many problems of engineering in which the location in the space of the variable under study is considered, based on definitions of mathematics that provide the necessary foundation for its application. In particular, the Geostatistics are applied in the spatial estimation of the recoverable reserves of mineral deposits. The geostatistical methods that are used in the estimation of mineral deposits are implemented in industrial software and consider the evaluation of the complex geological structure, but these softwares only display the obtained results with an input data and do not exhibit the concepts thatthey use during the process or the methodology of its application. This happens particularly with the Kriging method, which is based on the assumption of strict stationarity, taking into account changes in the mean and local variations, therefore unreliable. In this study is established to review the Kriging method, its application in the estimation of the recoverable reserves of mining deposits and the relevance of the developed model established particularly in mines ofPeru, which use this method as part of the mining exploration for the evaluation of the feasibility of exploitation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.