Graphene oxide and graphite oxide used as reinforcement in composites synthesized from cellulose acetate and polyacrylic acid

This work focused on the synthesis and characterization of composites, obtained based on polyacrylic acid and cellulose acetate, which incorporated graphite oxide and graphene oxide as structural reinforcement. The composites were obtained using the phase inversion method and the incorporation of the reinforcement, during the synthesis process, was carried out in proportions of 1% by weight. The characterization of the composites was carried out using IR, Raman, BET, SEM spectroscopy techniques and methods for determining acidic and basic sites. The results obtained showed that it is possible to synthesize composites that present a network configuration, made up of layers that give the material the effect of depth. Furthermore, it was possible to observe that both graphite oxide and graphene oxide were deposited on the outer edge of the hexagonal pores present in the material. Finally, the concentration values of acidic and basic sites were obtained. The presence of these sites could be associated with carboxylic groups inserted during the oxidation of graphitic materials and with non-reactive sites present in cellulose.

Methodology for the design of a multilayer polymeric membrane system with potential use in hemofiltration

Chronic kidney disease is generally complicated by poor care or by ignoring it. Among the causes that influence these conditions are obesity, diabetes, smoking, or genetic inheritance. Coordinated efforts are currently being made in multiple countries to control a strong case rate. The clinical techniques of treatment rely on the efficiency of blood purification (function that´s done by kidneys in organisms). Therefore, there is great interest in the development of devices that accomplish this function. Hemofiltration through porous membranes is an efficient process, but the flow conditions in a microchannel system can be complex. Analysis of blood flow in a parameterized conduit arrangement shows streams with desired trajectories, others are held back (stagnant), and others return to the stream from which it´s separated. In addition, the friction conditions and the reduction of the area drastically reduce the movement of the fluid, promoting clogging and consequently the inhibition of filtering. Based on these simulation results, it was proposed that the membrane coupling system could be modified to eliminate extensive flow in conduits generating a new concept of separation through a threshold.

Parametric design applied to die cutting machine

In this paper, the particularities of applying parameterization in industrial machines corresponding to the manufacturing area are exposed and analyzed. For its development, the parameterized design of a die cutting machine is proposed as an object of study, which is formulated from the main elements considered of importance in the principle of operation, being necessary to carry out a prior investigation to analyze it and how the parameterization process influences. Parameterization is a quality of the components to adapt flexibly to the needs of the industry or sector, facilitating the redesign and manufacturing process, allowing the desired dimensional update or adjustment to be carried out only to the central component and the others are automatically adapted. Attending to the current needs and trends of the fourth industrial revolution, as well as establishing the benefits of this type of flexible design processes to expand their implementation to different industrial machines such as robot configurations.

Removal of Oil Pollution in water using hydrophobic silica

Nowadays the contamination in waters by oily substances turns out to be a problem of world-wide scope and although some methods of removal of oils in water exist; these present some limitations; therefore, this project proposes the use of hydrophobic silicas as absorbent materials for oily substances. Modified silicas (R-SiO2) were synthesized using the Stöber method, modifying the surface by co-condensation. Tetraethyl-orthosilicate (TEOS) and two surface modifiers were used as silica former: Methyl-trimethoxysilane (MeTEOS) and n-octyl-triethoxysilane (nOctyl-TEOS). The R-SiO2 were characterized by infrared spectroscopy identifying the modifying groups and their hydrophobicity was qualitatively evaluated according to the change in solubility in water. Finally, the removability of an automotive motor oil was evaluated by determining the amount of oil removed per gram of modified silica.

Estrategias bioclimáticas para el diseño de edificios vinícolas

Greater amount of energy consumed in wineries is used for cooling and humidifying of the interior, for this reason the correct design of energy efficient wineries has become an important issue for winemaking countries. The purpose of the design of buildings that require less or no energy to achieve controlled conditions of the indoor hygrothermal environment for production and aging of wine, allowed to formulate the objective of this work, which was to evaluate six models of wineries with bioclimatic design located in El Valle de Guadalupe, Baja California from data on thermal performance (indoor temperature and relative humidity) and energy consumption (kWh and degrees-hour), obtained by dynamic thermal simulation. The zone of the study was characterized, based on the review of previous studies optimum temperature ranges were defined for aging and wine production. A basic model of a winemaking building was designed to which bioclimatic strategies were applied. The results obtained allowed to suggest the best bioclimatic design options for this type of buildings.

Caracterización comparativa de biopolímeros de almidón extraídos de cereales mediante dos técnicas diferentes

In the field of research and consequent elaboration of biopolymers it has been growing in the last decade, either due to the hardening of the environmental legislation of each country or due to ecological awareness, in any case the term biopolymer is quite broad, these being used as material premium in medicines, food supplements and of course in the production of bioplastics. Since the topic of interest is the comparative characterization of biopolymers using starch extracted from two different cereals, oats and rice, using the alkaline technique with NaOH treatment and the milling technique, assuming that the starch extracted from the Oryza sativa cereal presents chemical characteristics, geometric and mechanical superior in both techniques used unlike the polymers made with Avena sativa starch. These results suggest that the starch quality of each cereal is relevant for the production of biopolymers [1]. The commercially significant properties of starch, such as its mechanical strength and flexibility, depend on the strength and character of the crystalline region, which depends on the ratio of amylose and amylopectin.

Instrumentación electrónica de una estación meteorológica automática

Climatological studies present a common restriction in decisionmaking based on meteorological data, since climate models often lack precise values of their parameters depending on the geographical point where the information is acquired, therefore, climate acquisition in specific geographical positions is an interesting possibility. The objective of the present study was to develop the electronic instrumentation of an automatic weather station (AWS) using a controlling medium with sensors that measure air and soil temperature (°C), relative humidity (%), solar radiation (Wm2 ) and wind speed (m/s). The acquired data were compared with commercial stations Vantage Pro (VP) and GroWeather (GW) of the Davis Instruments family where an R2 of 0.93 was obtained in Temperature and Relative Humidity of the air and an R2 of 0.94 for solar radiation. Thus, the developed AWS presents benefits in the quality of the acquired data that can be used for studies of mathematical modeling and generation of decision-making.

Análisis de las irreversibilidades en un proceso de paro y arranque en un sistema de refrigeración con R-134a

In this work, an evaluation of the energy in a start-stop process is made by analyzing the generated irreversibilities in a refrigeration system by mechanical vapor compression with R-134a refrigerant at a flow of 1.0 L / s. This system is installed in the LABINTHAP of the SEPI-ESIME-IPN. For this analysis, there is software that captures data on the pressures and temperatures from the refrigerant at the inlet and outlet of the evaporator, compressor, condenser, and expansion valve at oneminute intervals. For the analysis of the generated irreversibilities, the first and second laws of thermodynamics were used. And, in the process evaluation of stopping and starting, it was shown that the compressor sets a trend of higher energy consumption, so a process of regulation of the refrigeration system by mechanical compression of steam is proposed.

Análisis experimental y teórico del ensayo de adherencia capa – sustrato en un acero DIN UC1 tratado termoquímicamente por borurización

In this work, the effect of the boronizing thermochemical treatment on the adherence and surface morphology of the boride layer formed in DIN UC1 steel was evaluated. The process was carried out by packing at the temperature of 1273 K, at the times of 4800, 6000, 7200 and 14400 seconds. The HRC adherence test based on the VDI 1398 standard, was simulated in COMSOL 5.0®; analysing the effect of the thickness of the boride layer and the roughness on the Von Mises stress, in addition to the stress on the indentation footprint; in which it was observed that by increasing the thickness of the layer from 22.2 to 37.8 µm the stresses increased, and therefore the adhesion of the layer on the substrate improved, which causes only the formation of microcracks. On the other hand, in the greater layer thickness (60.04 µm) the layer delaminates. Therefore, for an industrial application of DIN UC1 steel treated thermochemically by borurization, layer thicknesses up to 37.8 µm are recommended.

Viabilidad de propuesta de servicio de supervisión remoto en el sector agroindustrial

This research paper presents a study methodology for the feasibility analysis of a proposal for agro-industrial application with Unmanned Air Vehicles (UAV) or Drones. For this purpose, a qualitative exploratory study is carried out to publicize the essential information collected in the field that allows to know in detail and with greater certainty the needs and main factors related to the crops of the current market, as well as identify the necessary tools to determine this purpose. Important for this study is the collection of reliable information through the application of interviews with specialists and staff with experience in this sector to define the points of interest and through this know the results of the study for formulating a hypothesis. From these indicators, the degree of acceptance will be determined in the most assertive and well-founded manner and the approach made the crop directed, with the aim of ensuring the efficiency and quality of the service in order to make the decisions achieve the expected technological impact.