Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

One of cases considered for diagnosing DNA damages is diagnosing DNA probable damages against oxidizing agents, including oxidizing chemicals and various incident rays which cause the bases in the DNA to be oxidized and especially bases G in the DNA sequence which is more easily oxidized than the other bases. Therefore, the main objective of this comprehensive survey is to provide relevant information on measure physical chemical properties of nucleic acids during DNA radicalization and incidence of cancer using theoretical methods. The aim of the present study is to examine the single-stranded NBO with sequences of GG, CG, AA AG AC: AT CT GT TT followed by the levels of energy and form of orbital LUMO and HOMO obtained from Gaussian computations for above double-stranded sequences. Our results showed that form B genetic material is the most stable structure against physical and chemical agents. Only the number of molecular population and the levels of molecular dynamic vibration and molecular thermochemistry such as enthalpie and entropie are temperature independent. In addition to this, the gap between the layers and the potential and energy needed to oxidize the components in the two strands of DNA and its optimum structure will not change with temperature. Optimum conditions on DNA and its bonds are the temperature of 37 ° C and pH is 7 to 8.7. DNA has form B and the rate of physical protection is the highest.

This paper deals with the importance of research competence in university students studying some engineering and a proposal for their development. The methodology used was developed in three phases, the first phase consisted of identifying the problem of lack of research in the countries of Latin America, for this purpose, research rankings, rankings of research centers and ranking of universities were analyzed, because they are the spaces where research should be developed in each country. The second phase consisted of making the state of the art about the efforts made in each country to achieve research competence. The third phase was the description of the proposal of research seedbeds for the development of said competence. The main result was the proposal of research seedbeds for the development of the research competence in engineering, which is being applied at this moment. In conclusion we have that the binomial of the research nurseries and the combined learning will allow to develop the research competence in engineering students.

Industrial arms should be able to perform their duties in environments where unpredictable conditions and perturbations are present. In this paper, controlling a robotic manipulator is intended under significant external perturbations and parametric uncertainties. Type-2 fuzzy logic is an appropriate choice in the face of uncertain environments, for various reasons, including utilizing fuzzy membership functions. Also, using the neural network (NN) can increase robustness of the controller. Although neural network does not basically need to build its type-2 fuzzy rules, the initial rules based on sliding surface of higher order sliding mode controller (HOSMC) can improve the system's performance. In addition, self-regulation feature of the controller, which is based on the existence of the neural network in the central type-2 fuzzy controller block, increases the robustness of the method even more. Effective performance of the proposed controller (IT2FNN-HOSMC) is shown under various perturbations in numerical simulations.

This work aimed at the development and determination of the ideal formulation for the production of cassava, as well as the determination of the impact of drying kinetics on its sensory properties. Three formulations were prepared for the production of cassava of the variety Valencia (sweet) and cassava of the variety Ceiba (bitter), for the mixture design was counted on three variables; (Cassava flour, sea water and garlic), where it was determined from the mass-energy balance and sensorial analysis with hedonic tests applied to people belonging to the Garífuna people, that the casabe made from cassava of the variety Ceiba is the most accepted, at the same time the drying temperature, heat transfer speed and yield in the elaboration. Subsequently to the selected cassava were determined percentages of moisture, dry matter, protein nitrogen, protein, crude, fiber, ash, fat, starch and crude energy. The chemical quality of the Honduran casabe was compared with the Venezuelan one, being different in its composition and due to its poor nutritional value, could affect the health of the Garífuna people of Honduras.

The drainage system is used to guide the flow of water in the earth dams. Construction of drainage in the dam body to collect and direct the drainage formed in the dam body to keep the slope dry and prevent the increase of pore water pressure in the body. One of the main goals of the designers is to find the minimum factor of safety and, consequently, reduce the cost of construction. In this study, the Marvak dam is modeled with the actual characteristics of the materials in the Geostudio software, and with the change in the dimensions of the drain, the material and the slope of the dam body, the minimum Factor of safety of the dam is obtained. In order to predict the minimum Factor of safety, a two-layer neural network has been used. With the training of the neural network based on the data obtained from heterogeneous dams, a minimum Factor of safety has been extracted for optimization of drainage. Finally, it was determined that the internal friction angle of the body material and the slope of the dam have the greatest effect on the dam factor of safety.

Daylight is one of the most significant light source which could illuminate interior spaces by passing through windows and light collectors. Dust and aerosol accumulation on windowpanes reduce the light amount passing through it. The main objective of this research is to determine the impact of airborne particulate matters deposition on past light quantity. In this experiment the most prevalent particulate matters such as dust, carbon, and a mixture of both examined with 3 mm common commercial glasses at single and double glaze windowpanes and several interesting observations have been obtained. The result of this experiment will help building owners to adjust a window-cleaning schedule to reduce their lighting electricity consumption and expenses.

In this article, the design and implementation of an industrial plant for the treatment of effluents generated in the production process of a tannery was developed in order to achieve its treatment and reuse in the activities of the company. Currently there are no major advances regarding the management of their effluents, being these directly disposed to the sewage system which has caused the breach of the environmental regulations in force in the country, causing a negative impact on the environment, in addition, it has been wasted the potential of reusing them within their processes. Due to this, it was decided to develop a technical study that allows to implement the proposed treatment plant according to the needs of the company. The treatment system is divided into three units, the first one for Pre-treatment of the effluents, the second one for the physical-chemical treatment and the last one for the conditioning of sludge.

The double-tube heat exchanger is one the simplest piece of equipment which performs heat exchange in a continuous mode between two fluids. In the present work the thermal design of a double-tube heat exchanger for the cooling of a liquid acetone is carried out. It was also evaluated the influence of the increment of acetone feed flowrate over six design parameters of the heat exchanger: 1) overall heat transfer coefficient; 2) heat transfer area; pressure drop of 3) acetone and 4) ethylene glycol streams; 5) heat exchanged and 6) total amount of hairpins needed. The heat exchanger must have a total heat transfer area of 6.0 m2 and a total amount of hairpins of 10 to fulfill the system’s thermal duty. Both the acetone and ethylene glycol streams have pressure drop values lower than the maximum allowable limit established by the process (110 000 Pa). The increment of the acetone feed flowrate causes the increment of the six parameters studied.