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

Land Surface Temperature (LST) is a key variable in the interactions and energy fluxes between the Earth surface and the atmosphere. The MODIS LST nighttime at spatial resolution of 1 km was analyzed during the period 2003-2017 (June-August) over Peru to identify regions exposed to low temperatures. Our result shows that the regions below 0°C are above 3500 masl (in average). In addition, the mean monthly nighttime LST is correlated with the mean monthly minimum air temperature (R = 0.96, N = 763) and the topography significantly influences the variability of LST.  

This article contains two parts, one introductory and the other with the development of an educational program for children from 5 to 7 years of age. The theory and findings of genetic psychology showed that children between 5 to 7 years of age possess intuitive notions about space, that is, notions of space based on the perceptual data of objects (visuotactilokinestesicos character data) and on the spatial images that arise from the manipulatory-perceptive activity of the child on the objects he perceives, allowing him to group objects in figurative and non-figurative collections, which genetic psychologists Jean Piaget and Bärbel Inhelder have described in terms of simple symmetries: mirror, axial and of rotation. This intuitive mastery of the symmetries in the child has led us to propose a set of activities to apply the mentioned symmetrical rules so that the children can discover with the guidance of the teacher, the intra- and inter-figurative properties of the elementary geometric forms for which three phases have been designed, followed by a fourth in which the child solves simple fractal problems through symmetric composition rules acquired in the first three phases. Based on the theoretical framework adopted and some background, we propose the Development of Geometric Intuition (DIG) program organized into two modules (I and II) with two phases per module: first and second phases in module I and third and fourth in module II.

 Radon monitoring was carried out at the Coricancha mine in order to establish a baseline on the concentration levels of this radionuclide in an underground mine in the Andean region of the country. The concentrations obtained are distributed in a wide range, from 245 to 1897 Bq/m3, with an average of 565 Bq/m3, a value that is below the limit established in the Regulation of Radiological Safety.

Contenido del Programa

Contenido del Programa

The present work, the spatial and temporal evolution of the Vegetation Condition Index (VCI) is analyzed, with the purpose of identifying patterns relevant to the occurrence of agricultural drought events in Piura. The VCI provides information about the growth state of the vegetation during extreme situations, and it is derived from the product: Normalized Difference Vegetation Index (NDVI) values - MODIS (Moderate-Resolution Imaging Spectroradiometer) sensor data at a spatial resolution of 1 km in the period 2000-2017 on board the Terra satellite (MOD13A3, version 6) Obtained in its passage between 10:30 am and 12:00 pm (local time). The spatial patterns of the VCI reveal that, in the case of rainfed agricultural areas, in 2004, 21 % presented extreme and severe drought conditions, while in 2007 it was 19.5 %, in 2011 the 15.5 % and 2014 reached 21 %. On the other hand, in the case of irrigated agricultural areas, 44.2 % were affected in 2004, 55.4 % in 2005, 38.8 % in 2007, 17.1 % in 2011 and 37.1 % in 2014.

This work develops a bidirectional electronic converter of AC/DC electric power and evaluates its performance indicators, all this study in a context in which it seeks to increase the generation of renewable energy sources in the energy matrix of Peru, especially solar and wind sources. In this scenario, the bilateral conversion systems of DC and AC energies [5] are of great importance, we seek to have an efficient behavior and with advanced control techniques that allow us to reduce harmonic distortions, as well as to have the robustness before disturbances and minimize eventual instabilities that occur when connecting to the public electric distribution networks [2], (in a quantified way, the objective is to have less than 2% in THD, in the variable of interest). The development is done through the application of Predictive Control Based on Models in its version of application called Finite Commutation Set ("Finite Commutation Set" FCS), so the control units of the power stage are implemented with MPC-FCS control. The main results obtained using simulation tools (Matlab and PSIM) applied to these electronic power systems are shown (research objectives are established to achieve electrical efficiencies above 98%). This study takes into account the measurement of the magnitude and direction of the flow of power and electrical energy between the generation sources, the grid, the load and the energy storers. The most significant results are presented, which show the results and the methodology, which, in short, performs better than those do, implemented with widely used methods such as SVPWM.

Recently, great attention has been given to microbial fuel cells (CCM) due to their moderate operating conditions and the use of a variety of biodegradable substrates as fuel. The common microbial fuel cells consist of an anodic chamber and a cathode chamber separated by a proton exchange membrane. The microorganisms actively catabolize the substrate generating bioelectricity. These cells can be used as an energy generator for biosensors, giving this a great advantage for application in these types of devices. This paper presents microbial fuel lines, designed at low cost, in which the concentration of sludge has been varied, which was obtained from the oxidation lagoons of Covicorti, Trujillo-La Libertad. The values ​​of the average voltage were reduced as the concentration of the mud decreases, from values ​​close to 507.8 to 244.1 mV. The conductivity in the anodic chamber was around 14.5 to 7.75 μS / cm with a pH around 8.0. While in the cathodic carame a pH around 7.5 and a turbidity between 250 to 450 NTU was found, the values ​​of current intensity and power density also decrease with the reduction of residual sludge. With this work, it is about giving a new way of manufacturing CCM in an innovative and economical way.

The objective of this study is to isolate and identify potentially pathogenic anemophilic micromycetes for humans and possible biodeteriorators of goods from the San Marcos Cultural Center. Two interior environments were selected, the portrait deposit (DR) and the contemporary art deposit (DAC); 48 samples were taken, 24 in each room, 6 in each station, 3 at 11.00 h and 3 at 15.00 h. The gravimetric method was used to collect the sample; for identification, cultures were made and the microculture technique was used in foil. 96 strains of anemophilic micromycetes corresponding to 12 genera were isolated. 95,83 % (92) were molds and 4,17 % (04) were yeasts; the most frequent genus was Penicillium 60,42 % followed by Cladosporium 18,75%. The highest frequency of isolations occurred in summer 45,83 %. The environment with the highest frequency of isolations was the deposit of contemporary art 63,79 %. The presence of micromycetes belonging to the genera Cladosporium, Aspergillus and Paecilomyces associated with diseases in humans was demonstrated; and of Penicillium and Cladosporium associated with the deterioration of goods of organic origin.

The objective of this study was to perform the analysis of the spatial and temporal variability of the precipitable water vapor column (PWV) on the northern coast of Peru (3°S-7°S). A total of 17 years of PWV data obtained from the MODIS/Terra sensor were analyzed, from which maps of provisional climatology and standard deviation were generated, in order to obtain the patterns of average spatial distribution and temporal variability. The provisional climatological map of PWV shows in general that the areas with the greatest variability of PWV are found in the ocean and lowlands, while the areas of least variability are found in the Andes region. The Hovmöller diagrams and the time series identified an annual cycle and the increase of the extreme values in the summer months from the year 2010. The power spectral analysis of the time series apart from identifying the annual period also identifies a period semiannual that is due to the seasonal change summer-winter.