Utilization of solar energy for the fulfillment of daily routine tasks has gained a lot of interest in the recent past. The complete utilization can be accomplished only if proper solar data is available for a particular site. The measurement of solar data is expensive and time consuming. Different empirical correlations are available for the estimation of solar radiations on a particular site. In this research, monthly average daily solar radiation on horizontal surface is compared with measured data available as typical metrological year, TMY2, and estimated from the different solar models available for Karachi. The models studied are Ahmad models, Raja Models, Hargreaves Model and Black model. The estimation of different empirical correlations and NASA are compared with the measured values. The comparison was done by using statistical techniques like MAPE, MBE, RMSE and t-stats. The results revealed that Hargreaves model is the best model to estimate global radiation for Karachi with minimum value of t-stats while Raja 3 model is the most inappropriate model with highest value of MAPE, RMSE, MBE and t-stat. Overall, the already established empirical correlations can be used for the estimation of solar energy for Karachi for complete utilization of solar energy with minimum errors.

Based on the concepts and insights of cybernetic theory and the applications of applied electronic engineering and control, this article deals with the design of an analog compressor with digital control. The main purpose of the device is to control the basic parameters of a hardware using an application on a micro-controller. The advantage of that design is the possibility of store the different analog positions into a digital position of the memory of the micro-controller, in order to call these presets whenever its needed. Further possible applications include the virtual-remote monitoring of events where the interaction between artist and sound engineering is required. keywords: Analog compression, digital control, HW of audio, electronicmicro-controllers.

In this article, the correction of the distorted electrical signal with an adaptive neural fuzzy logic (ANFIS) due to noise forming in is discussed. An electrical signal, such as a sinus signal, is widely used both in load supply and in modulation techniques for control and information transport. While the deterioration in the sinus structure causes energy losses, it also causes damage to the control and information transmission signals. Therefore, after considering the structure of the clear reference signal equation, a noise that may occur in the sinus structure is included in the clear reference signal structure. An interference signal must be formed with the unknown nonlinear process from another noise source for measuring of the information signal because of an interference signal needs. After an interference signal is generated, the measuring signal is given in the sum of the pure reference signal and the interference. For the correction phase of the signals, at inputs of the adaptive fuzzy logic system in the Matlab toolbox, the source signal with noise and the measuring signal values are entered and the experiment is performed via a 3-membership function. When the results are observed, it is seen that the signal which is distorted after the correction operations is very close to the reference signal

Chlorothalonil (CHT) is a chlorinated-nitrogen fungicide used in the control of black sigatoka, a disease that affects banana and plantain, has adverse effects on the environment and its metabolites can be toxic. The CHT has been the object of several studies related to its behavior and degradation in the environment; however, few works have been developed in tropical areas, such as the case of the banana zone of Magdalena - Colombia. In addition, it is unknown if the microbial diversity existing in these soils can transform compounds such as CHT, thus these microorganisms can be the basis for the implementation of remediation strategies based on bioaugmentation. In this sense, the present study aims to evaluate the degradation of CHT in soils of a tropical coastal zone, under conditions of natural attenuation and bioaugmentation with native microorganisms. For this purpose, microorganisms capable of growing with CHT as their sole carbon source (10.8 mg.L-1) and tolerating a concentration up to 25 mg.L-1 were isolated and selected from soils in the Magdalena-Colombia banana zone. Subsequently, CHT degradation tests (2000 ng.g-1) were performed on experimental plots, with bioaugmentation of native microorganisms and natural attenuation during 35 days, evaluating the growth of microbial populations and the degradation of CHT by gas chromatography associated with a mass spectrometry detector (GC/MS). Because of the microbial selection process, 8 morphotypes were obtained with the ability to grow in CHT as the sole carbon source and tolerate concentrations up to 25 g.L-1. The isolates were identified by sequencing the 16S rDNA gene as belonging to the genera Enterobacter, Klebsiella, Pseudomonas and Citrobacter. The CHT degradation tests showed that under bioaugmentation conditions with the native microorganisms selected in the study, a 100% reduction was achieved after 21 days; while under natural attenuation conditions after 35 days the degradation reached values of 98.5%. The application of bioaugmentation of selected and enhanced bacteria increased the rate of pesticide degradation by ~2.5 times, reducing the half-life from 6.2 to 2.5 days. The results demonstrated the effectiveness of the bioaugmentation treatment and that the selected consortium may be useful for bioremediation of banana crops soils contaminated with the fungicide.

The pulse width prediction control technique has been widely used in AC-DC converters with power factor correction in boost topology, where satisfactory results have been reported without the need to use classic control laws. However, this technique has not been explored for other types of ACDC converters with power factor correction. In this work, the use of this technique is proposed in an AC-DC converter with power factor correction in a half-bridge boost topology. This topology presents high efficiency because it uses the least number of semiconductors compared to other topologies. In this technique the duty cycle is predicted by processing the average values of state and input variables of the converter in half bridge boost topology, using only four multiplications and five additions, which implies less complexity in its implementation. For its validation simulations were performed using MATLAB R simulink, where it was possible to observe values of power factor and THD comparable with other control methods such as non-linear carrier control, and conventional analog control, both reported in the literature.

The main objective of this article is to evaluate the wind resource in the city of Floridablanca, Colombia. In Colombia, the supply of electrical energy comes mainly from hydroelectric mega-power stations, presenting generation problems in times of drought. The wind resource is an adequate alternative to diversify the electricity supply in the country. To analyze the characteristics of the wind, recorded measurements were carried out, every 15 minutes at a height of 30 m, throughout the year 2016, at a meteorological station located in Floridablanca, Colombia. In this study we present a statistical analysis of the wind characteristics in Floridablanca, Colombia, we applied a Weibull distribution of two parameters to model the wind speed and thus determine the wind potential. The average annual speed was 0.72 m / s with a standard deviation of 0.61 m / s. The monthly Weibull scale parameter varied from 0.52 m / s to 0.91 m / s, the monthly parameter varied from 0.98 to 1.37. The highest power density observed was 0.35 w / m ^ 2 in the months of February and August, the monthly average power density was 0.23 w / m ^ 2 which indicates a very poor wind potential considering that they are considered good wind potentials greater than 500 w / m ^ 2. This study contributes to evaluate the wind potential of Floridablanca, Colombia, and can be used, methodologically, to quantify the wind potential with possibilities of generating electric power in any part of the country.

In electrical systems the most critical disturbance is the interruption of the power service. However, the main concern for many commercial and industrial users is the mal-operation produced by voltage sags. This paper presents a study about performance of a distribution system in presence of voltage sags using a distribution generation (DG) unit and a distribution static compensator (DSTATCOM). The analysis is performed by using a stochastic generation of disturbances method and ATP/EMTP software tool. Several case studies in the IEEE-13 bus test feeder taking to account different DG locations and penetration levels for DG unit are presented. In addition, the relation between the injected DSTATCOM reactive power, the type of sag and the location of affected nodes is considered. Simulations show that for IEEE-13 system the DSTATCOM is the best alternative for sags mitigation. However, the DG unit is an alternative that can be considered in larger distribution systems to reduce the effects of voltage sags.

In this article, the comparison among different techniques applied to simulation and representation of the expansion of the coffee berry borer in the Colombian coffee crops is carried out. First, a brief description of supervised techniques (models focused on data adjustment): Neural networks, neuro-fuzzy and fuzzy logic. Then, implementing these models is described. Finally, the comparison among these models is shown, highlighting performance of neuronal networks.