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

This work presents ANOVA and Tukey’s statistic tests that were carried out in Knoop microhardness results of boron carbide sintered samples. Three samples, A, B and C, of different processing conditions were tested and statistical analysis showed that microhardness results are strongly influenced by porosity and chemical composition, mainly due to presence of C(2H) and WB2.5 contaminant phases. Those phases promoted higher densification in A and B samples and it was found that A ≈ B > C is the relation between the microhardness results of the samples, while A ≈ B < C is the porosity ratio of the samples. Furthermore, this work aims to apply a statistical tool to evaluate the microhardness results performed on advanced ceramics and, using these results, to control parameters in the sintering process, showing that a deeper statistical analysis is necessary for the interpretation and validation of the results merit.

Information security is the set of forms that secure data faraway from illegal connection, revelation, duplication, alteration. As of late, increasingly legitimate frameworks such as resourceful inter and intra urban city, remote sensor systems, authentication digital signature frameworks, and superintendence, have recently needed data security affirmations. Hence, over the past researches numerous diverse strategies focused on cognitive intelligence are created for data security. In any case, there are not complete reviews which recapitulate strategies. In this way, this document surveyed on cognitive intelligence move toward presented on publications and symposiums for data security within most recent years. This article gives a precise review to audit various cognitive intelligence access and applications of data security. In additionally, deliberate the threat of cognitive intelligence access and applications for data security is conferred.

In this article, a model is established for the planning of the weekly distribution of refreshments in a company that produces 6 types of beverages in 3 Production Centers, with the potential use of 3 Distribution Centers and supplying 22 Consumer Centers located in Bogota. Due to the impact of transportation costs on the company profits, it is necessary to determine the optimal planning of the allocation of sources to destinations in the nodal network of the system and its subsequent routing with two types of vehicles. Therefore, a two-phase model is proposed. In the first, the initial optimal assignments are established by comparing two techniques; one based on the Open Transshipment Problem (OTP) and the other on the Capacitated Transshipment Problem (CTP), which determine the trips to be made from production centers to consumer centers using distribution centers as intermediaries. This comparison allowed to analyze its efficiency to choose the model with the lowest cost and number of trips. In the second phase, routing was performed on routes that do not use the full capacity of the vehicles. The routes were established through the Travelling Salesman Problem (TSP). As a result, a comprehensive model was obtained to carry out the planning of the product distribution, obtaining in Phase II the use of the OTM model, which presented 14% less distance; 2.6% less time and 0.28% less than the total cost compared to the CTP model. In Phase II  5 routes were obtained, of which Distribution Center 2 covers 59% of customers.

Cellular manufacturing systems (CMS) are a major application of group technology, that brings benefits related to the reduction of wastes, also known as ‘mudas’ in lean manufacturing philosophy, to organisations striving to compete on today’s markets. These benefits include the reduction of machine setup times, material handling and work-in-process inventory, among others. However, many organisations are reluctant to implement such decisions in their production systems, due to the uncertainty and economic and productive impact that these involve. For this reason, a simulation study is performed in this paper to evaluate the performance of a cellular manufacturing system approach for the sewing department of a sportswear manufacturing company. The simulation study was designed, and the results of the proposed model showed improvements of 51,46% in the average flow time, 1102,52% in the average throughput, and 50,65% in the average setup times of machines, compared to the current state of the case study.

Tungsten heavy alloys 90W-7Ni-3Co (WNC) and 89.6W-6.2Ni-1.8Fe-2.4Co (WNFC), produced using liquid phase sintering followed by thermo-mechanical processing, were investigated for microstructure and mechanical properties. 90W-7Ni-3Co alloy processed following a cyclic heat treatment showed fine tungsten particles in the matrix. The alloy, when heat treated at a temperature 850°C (the lower temperature of cyclic treatment), formed a W-rich intermetallic phase in the matrix that subsequently dissolved during high temperature (1150°C) solution treatment leaving behind fine W particles. On the other hand, the matrix phase of the alloy, 89.6W-6.2Ni-1.8Fe-2.4Co showed a clean structure devoid of any such precipitates. Both the alloys were subjected to a thermomechanical treatment that included two stage swaging with intermediate heat treatments. 90W-7Ni-3Co alloy exhibited superior strength, but lower elongation to failure and impact toughness as compared to 89.6W-6.2Ni-1.8Fe-2.4Co alloy. Microstructure-property correlation was undertaken in order to elucidate the effect of enhanced W dissolution and fine W precipitates (in the matrix) on mechanical behaviour of the alloys investigated.

The corona virus or SARS-CoV2 is a pathogenic virus that has become a pandemic and a threat in almost all countries in the world. SARS-CoV2 belongs to the Coronaviridae family with particle sizes varying around 60 nm - 140 nm. Various regulations and prevention have been designed to reduce the impact of Covid-19 by SARS-CoV2. Several technologies and studies have been developed to form nanofiber woven membranes. Cellulose nanofibers and chitin/chitosan nanofibers have been studied and are known to have nanometer-sized structures smaller than SARS-CoV2. Chitin/chitosan has been investigated to have antiviral properties, especially corona virus. Cellulose nanofibers, and chitin/chitosan nanofibers has the potential to be developed for Covid-19 virus nanofiltration masks. Various active agents (nanosilver, nanogold, CuO, etc.) have been known to have antiviral and/or antibacterial properties so that they can be used as nanofillers to enhance the performance and effectiveness of nanofibers based masks against SARS-CoV2.  

The usage of wheeled robots in service robots such as planetary exploration robots, pick-and-place robots, cleaning robots, surveillance robots, etc., is continuously increasing day by day. The primary purpose of these service robots is to reduce human resources and minimize human life risk in a hazardous environment. Therefore, in this article, the authors purpose and design the all-terrain differential-driven caterpillar-wheeled based unmanned Fire Extinguisher Robot (FER), which can detect and monitor the fire by using gas (smoke) sensor and temperature sensor. Also, it can extinguish the fire by spreading the fire extinguisher gas. The proposed unmanned FER has been divided into the two assembled units, one unit drives the FER, and another unit is for spreading the fire extinguisher gas through the nozzle of the cylinder. The driving unit of unmanned FER consists of six DC geared motors, two dual DC motor drivers, caterpillar driving wheels, Arduino MEGA microcontroller, Bluetooth module, gas sensor, temperature sensor, and rechargeable lithium-polymer (LiPo) battery. Next, the one DC motor connected with a motor driver controls the fire extinguisher gas cylinder's open and close valve through a Bluetooth signal from an android phone. The specially designed chassis and caterpillar driving wheel arrangement help the FER to travel in any terrain, including stair climbing. Real-time experimental tests have been carried out on the designed unmanned FER during the fire extinguishing process to prove the effectiveness of the developed FER.

The aim of this study was to evaluate the design and implementation of the Information System for Cervical Cancer Detection Program in Women in the Institute for Social Security and Services for State Workers. We performed a retrospective study applying the framework and tools for Performance Routine Information System Management (PRISM). A sample of 38 subjects was interviewed in 13 health facilities. The information system’s evaluation showed an overall performance of 73.7% at the beginning of 2017. The improvement between versions was mainly observed in the quality of the data (64.6% vs 72.5%), while the use of the information was very similar (78.6% vs 78.9%). We concluded that this information system provides good information to follow-up and control of its beneficiary population. However, there is an opportunity to improve health staff training, also new indicators for health outcomes are required.

The use of materials capable of controlling the threshold temperature required in hyperthermia, as well as meeting desired requirements in biomedical applications is still a challenge. In the present study, strontium doped calcium lanthanum manganites La0.7Ca0.3-xSrxMnO3 (x=0, 0.1, 0.15 and 0.2) were synthesized by co-precipitation method. Vibrating sample magnetometry (VSM) was used to study the effect of change Ca-Sr ratio on magnetic properties. The Curie temperature (Tc) increases from 272 to 315 K as the concentration increases from x=0 to x=0.2 respectively. Hence the strontium amount plays an important role in achieving the desired Tc . X-ray diffraction (XRD) was used to identify rhombohedral structure and scanning electronic microscopy (SEM) was used to characterize the cubic morphology and around 800 nm as particles size.

The present work is focused on the influence of zinc trivalent plating on laser shot peened AISI 304 stainless steel samples to improve the corrosion resistance of the steel surface. AISI 304 steel samples were heat treated by annealing and polished to perform Laser Shot Peening (LSP) process using Nd-YAG laser functioning at a pulse interval of 10ns with different energies of 200 mJ, 300 mJ and 400 mJ on each sample. The highest magnitude of compressive residual stresses is induced using the pulse density of 2500 pulses/cm2. The laser treated sample was characterized by surface hardness using Vickers micro hardness test and surface morphology using an optical microscope and SEM analysis. The surface hardness of the sample is increased by increasing laser energy. The prepared zinc trivalent is plated using electro deposition on the laser treated surface by maintaining current between 1.5 to 4 amps/Dm2, and temperature between 20 to 40 deg C. MAHR’s roughness tests were performed to find the surface roughness of the sample. The surface roughness has drastically increased on zinc coated samples compared to samples without coating. The Vickers micro hardness test conducted on zinc trivalent plated sample revealed the increase in hardness value of 200mJ by 24% compared with 200mJ sample without coating. SEM and EDAX were carried out to know the changes occurred in the chemical composition of the samples before and after coating.