Showing papers in "Dyna in 2016"

Sol-gel synthesis of zinc oxide nanoparticle at three different temperatures and its characterization via XRD, IR and EPR

Abstract: In this work, nanoparticles of zinc oxide were synthesized; they were formed using the sol-gel method (citrate route) at calcination temperatures (Tc) of 500, 550 and 600 °C. For all samples studied, IR spectroscopy showed the presence of the bands associated with water molecules present in the zinc oxide and carbon dioxide adsorbed on its surface. The formation of zinc oxide phase was confirmed by XRD, which showed that from 500 oC it had this type of Wurtzite structure. However, samples calcinated at 600 oC have higher crystallinity. Crystallite size was calculated using the Scherrer equation. The Rietveld method was used to obtain lattice parameters a and c for Wurtzite cell types as well as cell volume and the ratio c/a of each sample. These parameters do not show significant changes when they are compared with values obtained from samples with different calcination temperatures. Electron paramagnetic resonance showed the presence of defects in the zinc oxide. Three signals with g values of 1.96, 2.00 and 2.04 were associated with oxygen and zinc vacancies. Defects in the structure disappear when the calcination temperature is increased. The sample that was highlighted with the highest concentration of vacancies has a mean crystallite size greater than 30 nm, and this may also be responsible for this feature.

Application of the Delphi Method for the inclusion of externalities in occupational safety and health analysis

Abstract: Organizations should regularly conduct an assessment of their occupational hazards in order to design and implement preventive measures that are necessary and sufficient to deal with the level of risk, the costs of prevention and the safety at levels considered acceptable by the organization. Furthermore, the selection of measures to be implemented in an organization should take into account both internal and external costs. Externalities are of great importance in terms of the costs of accidents at work; nevertheless, they are not often properly addressed by the organizations. In this paper we describe an application of the Delphi method to understand how externalities can be included in Occupational Safety and Health.

Estado del arte sobre dispositivos activos y pasivos de control de flujo para turbinas eólicas

Abstract: Este articulo presenta una recopilacion del conocimiento disponible, referencias e investigaciones sobre los dispositivos activos y pasivos de control de flujo que inicialmente se desarrollaron para la aeronautica y que, muchos de ellos, actualmente se estan investigando e implantando en turbinas eolicas. El principal objetivo que se persigue con la implantacion de estos dispositivos es retrasar el desprendimiento de la capa limite y aumentar/disminuir las turbulencias. Con ellos se busca aumentar el coeficiente de sustentacion, reducir el coeficiente de arrastre o reducir el ruido aerodinamico, entre otros parametros. Sin embargo, conseguir estos objetivos presenta dificultades, ya que la mejora de uno de estos parametros puede suponer un efecto negativo en otro. Es por ello necesario estudiar en detalle cada uno de estos dispositivos, su concepto de funcionamiento, sus aplicaciones y sus principales ventajas e inconvenientes. Segun la naturaleza del control del flujo, los dispositivos se pueden clasificar en activos y pasivos. Las tecnicas pasivas permiten mejorar el rendimiento de las turbinas eolicas sin gasto de energia externa mientras que las tecnicas activas requieren energia externa para su activacion. Existen multitud de dispositivos. En este articulo se han recopilado algunos de los mas importantes tanto en el caso de dispositivos pasivos (Vortex Generators, Microtabs, Spoilers, Fences, Serrated trailing edge) como en el caso de dispositivos activos (Trailing edge flaps, Air Jet Vortex Generators, Synthetic Jets). Palabras Clave: Aerogenerador, control de flujo, sistemas pasivos, sistemas activos.

Tackling the challenges of an aging workforce with the use of wearable technologies and the quantified-self

Abstract: The world's population is aging at an unprecedented rate, this demographic shift will change all aspects of life, including work. The aging of the worforce and a higher percentage of workers who will work past traditional retirement years presents significant challenges and opportunities for employers. Older workers are a valuable resource, but in order to ensure they stay in good health, prevention will be key. Wearable technologies are quickly becoming ubiquitous, individuals are turning to them to monitor health, activities and hundreds of other quantifiable occurences. Wearable technologies could provide a new means for employers to tackle the challenges associated with an aging workforce by creating a wide spectrum of opportunities to intervene in terms of aging employees and extend their working lives by keeping them safe and healthy through prevention. Employers are already making standing desks available, and encouraging lunch time exercise, is it feasible for Wearables to make the jump from a tool for individuals to a method for employers to ensure better health, well-being and safety for their employees? The aim of this work is to lay out the implications for such interventions with Wearable technologies (monitoring health and well-being, oversight and safety, and mentoring and training) and challenges (privacy, acceptability, and scalability). While an ageing population presents significant challenges, including an aging work force, this demographic change should be seen, instead, as an opportunity rethink and innovate workplace health and take advantage of the experience of older workers. The Quantified-Self and Wearables can leverage interventions to improve employees’ health, safety and well-being.

Changes in EEG amplitude (Alpha and Beta waves) with Thermal environment

Abstract: When executing a task, brain activity can be observed through electric waves recorded in different frequency bands. The main ones are the Alpha, Beta, Theta and Delta waves. According to some authors, Alpha and Beta waves are related with cognitive capacity and, their presence and evolution, with an individual’ alertness. In this study, the intention was to evaluate how brain activity is directly influenced by temperature and humidity while performing a task. Therefore, a set of laboratory tests were undertaken to simulate sedentary work in two different thermal environments: 18oC - 40% RH (cold) and 35oC - 80% RH (hot). In the hot thermal environment, oscillation on Alpha waves amplitude suggests an alternation between periods of tiredness with periods in which concentration increases. Regarding Beta waves in the cold thermal environment, most of the time Beta activity is typically higher than that verified in the hot thermal environment.

Effect of amplitude and pulse in low frequency ultrasound on oil/water emulsions

Abstract: The application of ultrasound within advanced or emerging technologies requires selecting parameters that depend on the target application. This study evaluated pulse and amplitude parameters of oil/water emulsions (20:80% w/w) using low frequency probe ultrasound equipment (20 KHz). A categorical multilevel factorial design was used with Design Expert® in which the following pulse treatments were defined: continuous, pulse 20:20 (on:off) and pulse 30:30 (on:off), for five minutes. Six amplitudes (30, 36, 42, 48, 54 and 60 μm) were evaluated for the following response variables: separation of phases in emulsion, temperature and accumulated power. The results showed that the best condition to obtain an emulsion with less phase separation was the 20:20 (on:off) treatment with an amplitude of 42 μm. The ultrasound probe application parameters that were obtained will enable the design of stable products from low-fat emulsions.

Adsorption and catalytic oxidation of asphaltenes in fumed silica nanoparticles: Effect of the surface acidity

Abstract: This study aims to evaluate the effect of surface acidity of fumed silica nanoparticles in adsorption and subsequent thermal cracking of Colombian asphaltenes. The acidities of the surfaces were established through Temperature Programed Desorption (TPD) experiments. The adsorption equilibrium of asphaltenes was determined using a static batch method, and the data obtained was fitted using the Langmuir model, the Freundlich model and the SLE Model. Asphaltenes catalytic oxidation experiments were conducted, and it was found that this process was surface nature dependent. In all cases, the temperature of asphaltenes oxidation was reduced regarding the virgin asphaltene sample. The effective activation energies were estimated with the iso-conversional OFW method. This energy was found to be related to adsorption affinity and asphaltenes self-association on nanoparticles surface.

Thermodynamic properties of moisture sorption in cassava flour

Abstract: Se determinaron propiedades termodinamicas de adsorcion (entalpia y entropia diferencial, presion de superficie, entalpia y entropia integral neta) en harina de yuca a 25, 30 y 35°C, para proporcionar informacion sobre requerimientos de agua y de energia en el proceso de sorcion. Los modelos de GAB, Peleg y Halsey fueron los que mejor describieron las caracteristicas de sorcion, siendo el de Peleg el de mejor ajuste. Los diferenciales de entalpia y entropia disminuyeron con el incremento del contenido de humedad de equilibrio. La presion de superficie se incremento con el aumento de la actividad de agua pero disminuyo con el incremento de temperatura. La entalpia integral neta decrecio con el aumento de la humedad con una tendencia asintotica hasta 0.2920 kJ/mol para una humedad de 33.4 % (b.s); mientras que los valores de la entropia integral neta fueron negativos y se incrementaron hasta 0.1687 kJ/mol para una humedad de 29.2 % (b.s).

Use of white rot fungi in the degradation of an azo dye from the textile industry

Abstract: Textile industry effluents—a complex mix of chemicals, among which colorants are of particular concern—impose great environmental challenges. In this study, a full 2 3 factorial design was used for determining the best conditions for the degradation of textile dye Basic Red 46 under solid state fermentation (SSF). Three white rot fungi Trametes versicolor, Pleurotus ostreatus, and Pleurotus pulmonarius were used in the fermentation process. A maximum degradation percentage of 63.0% was achieved at 17 days of incubation with T. versicolor under a moisture content of 90%, carbon to nitrogen ratio of 12: 1, and at 20°C. P. ostreatus and P. pulmonarius reached a maximum degradation percentage of 69.3% and 63.1%, respectively, after 25 days of fermentation. The scale-up of the fermentation process using T. versicolor led to a degradation percentage of 45.7% after 30 days of incubation. Additionally, the enzyme activity of laccase, manganese peroxidase and lignin peroxidase was measured. The results indicate that SSF offers a satisfactory degradation, whose efficiency depends on the optimization of process conditions.

Managing relationships and communications in higher education efficiently through digital social networks: The importance of the relational coordination model

Abstract: Digital social networks have proven to be of great support for organizations that are increasingly using new forms of social communication every day, seeking to improve their productivity and competitiveness. The main objective of this study is to explain how organizations, particularly Institutions of Higher Education, can improve their competitive position through the use of digital social networks from the perspective of relationship management and management of communications, in order to achieve better results in terms of teamwork satisfaction, relationship marketing and educational excellence. For this objective, the application of a relational coordination model, based on the sharing of objectives, optimal knowledge management, mutual respect and efficient communication mechanisms, is suggested.

Detection and localization of potholes in roadways using smartphones

Abstract: A system for the detection and localization of roadway potholes is proposed and is aimed at collecting data on the roadway potholes using the accelerometer, GPS and compass that are embedded into smartphones using the Android operating system. This system has a scalable mobile architecture that contributes to capturing environment information using multiple devices with a large geographic coverage.

Factors influencing the occurrence of traffic accidents in urban roads: A combined GIS-Empirical Bayesian approach

Abstract: The problem of urban road accidents in Colombia is remarkable and has a significant magnitude. For this reason, a technical study of this important public health scourge is important. The quantitative techniques employed are usually highly aggregated and will not correctly identify the determinant variables of the problem. This paper examines the relationship between urban road accidents and variables related to road infrastructure, environment, traffic volumes and traffic control. Some accident-prone sections in the city of Cartagena (Colombia) are specifically identified by the empirical Bayesian method based on GIS. A total of 69 accident-prone sections were identified in the city. It was evident that the marginal effect on the accident rate for motorcycles is well above that for cars and buses. Empirical evidence also showed that the sections located in commercial areas tend to have higher frequency of accidents due to the high presence of pedestrians.

Strategic guidelines for supply chain coordination in healthcare and a mathematical model as a proposed mechanism for the measurement of coordination effects

Abstract: Supply chain (SC) management implies a large number of interactions and a great deal of cooperation between the organizations that make up the supply chain in order to fulfill the purposes of logistics processes such as supply, distribution and warehousing. Much research has been carried out to illustrate the advantages of coordinating these processes at different stages of supply chain planning. However, these studies appear to be separate efforts. This study proposes methodological guidelines for the coordinated planning of the supply chain in the context of the healthcare services, considering the global benefits to its members by using primary information collected at several health service institutions. The proposal also includes a mixed-integer programming model to show how organizational coordination contributes to a reduction of the overall costs throughout the chain.

Absenteeism and presenteeism costs from occupational accidents with WRMSDs in a Portuguese hospital

Abstract: The morbidity associated with WRMSDs leads to productivity losses (absenteeism and presenteeism) in healthcare organizations, which induces a substantive impact (cost).. The present study aimed to evaluate the impact (cost) of WRMSDs for accidents involving nurses and nurses’ aides in a small Portuguese hospital. It begins by identifying the workplace accidents (WA) that these occupational groups suffered between 2009 and 2013, which resulted in WRMSDs. Healthcare workers answered a questionnaire with WQL-8 and SPS-6 scales to determine the levels of presenteeism. This study adopted a human capital methodology in order to estimate the indirect costs of lost productivity from WRMSDs. Patient transfers are a major cause of WRMSDs, with most prevalent injuries being in the lumbar region. Between 2009 and 2013 there is a loss of productivity in this institution estimated of €222,015.98 from WA with WRMSDs that lead to absenteeism and presenteeism (€ 189,679.87 absenteeism and € 32,158.86 presenteeism).

Design of an open source-based control platform for an underwater remotely operated vehicle

Abstract: This paper reports on the design of an open source-based control platform for the underwater remotely operated vehicle (ROV) Visor3. The vehicle’s original closed source-based control platform is first described. Due to the limitations of the previous infrastructure, modularity and flexibility are identified as the main guidelines for the proposed design. This new design includes hardware, firmware, software, and control architectures. Open-source hardware and software platforms are used for the development of the new system’s architecture, with support from the literature and the extensive experience acquired with the development of robotic exploration systems. This modular approach results in several frameworks that facilitate the functional expansion of the whole solution, the simplification of fault diagnosis and repair processes, and the reduction of development time, to mention a few.

Current state of the art and enduring issues in anthropometric data collection

Abstract: The study of human body size and shape has been a topic of research for a very long time. In the past, anthropometry used traditional measuring techniques to record the dimensions of the human body and reported variance in body dimensions as a function of mean and standard deviation. Nowadays, the study of human body dimensions can be carried out more efficiently using three-dimensional body scanners, which can provide large amounts of anthropometric data more quickly than traditional techniques can. This paper presents a description of the broad range of issues related to the collection of anthropometric data using three-dimensional body scanners, including the different types of technologies available and their implications, the standard scanning process needed for effective data collection, and the possible sources of measurement errors that might affect the reliability and validity of the data collected.

Collaborative goods distribution using the IRP model

Abstract: This paper presents a study of the impact that collaboration in inventory has on distribution costs in a network of one supplier and multiple customers. Freight transport is widely studied due to its impact on logistics costs and service levels of enterprises. Looking for network configurations that improve some of these aspects will always be attractive to both academics and businesses. The collaborative distribution system was proposed using the IRP model, and it was compared with the scenarios in which the both supplier or customers optimize their inventory levels. For the IRP model solution a genetic algorithm was used, from which it was obtained a collaborative distribution system with a better performance than if the optimization is made independently.

Sparse representations of dynamic scenes for compressive spectral video sensing

Abstract: The coded aperture snapshot spectral imager (CASSI) is an optical architecture that captures spectral images using compressive sensing. This system improves the sensing speed and reduces the large amount of collected data given by conventional spectral imaging systems. In several applications, it is necessary to analyze changes that occur between short periods of time. This paper first presents a sparsity analysis for spectral video signals, to obtain accurate approximations and better comply compressed sensing theory. The use of the CASSI system in compressive spectral video sensing then is proposed. The main goal of this approach is to capture the spatio-spectral information of dynamic scenes using a 2-dimensional set of projections. This application involves the use of a digital micro-mirror device that implements the traditional coded apertures used by CASSI. Simulations show that accurate reconstructions along the spatial, spectral and temporal axes are attained, with PSNR values of around 30 dB.

Analysis of working nanofluids for a refrigeration system

Abstract: This paper presents the analysis of nanorefrigerant fluids to improve the thermal efficiency of a refrigeration system. Simulations in ANSYS FLUENT 15.0 were performed with mixtures of refrigerants R113, R123 and R134a, with Al2O3 nanoparticles at 1 vf% and 5 vf% (vf%, fraction volume concentration), flowing through a horizontal tube with a constant wall temperature. A mixture and the k-e turbulent models were employed to obtain results of heat transfer coefficient, temperature and pressure drop for each case. Results show an increment in thermal characteristics by adding 1 vf% and 5 vf% of Al2O3 nanoparticles to the three refrigerants selected. However, the size of the nanoparticle does not affect the thermal properties of nanofluid and the pressure drop does not show a specific pattern of behavior at different concentrations of nanoparticles. Finally, the mixture of R134a with 30 nm of mean diameter size Al2O3 at 1 vf% was selected because of its higher thermal efficiency and its favorable properties as a refrigerant.

Emerging risk in the construction industry: Recommendations for managing exposure to nanomaterials

Abstract: Nanotechnology has aroused great interest in the construction industry because new materials with outstanding properties are being designed, and the features of traditional materials can be improved. However, exposure to nanomaterials is the most recent new emerging risk in the construction industry and the current knowledge about this topic is limited. This paper aims to identify the main aspects regarding the exposure to and use of nanomaterials in the construction sector from a risk prevention perspective. This starting point allows authors to establish a set of recommendations structured in order to identify how and where to act in order to manage the risk of exposure to nanomaterial on construction sites.

Facile one-pot synthesis of uniform silver nanoparticles and growth mechanism

Abstract: Size controlled silver nanoparticles were obtained via chemical reduction using one-pot synthesis. Differently from other reported methods for silver nanoparticles, 1-octanol was used as both solvent and reduction agent, oleylamine and oleic acid acted as capping agents and silver nitrate was used as the metal precursor. Ultraviolet-visible and Raman spectroscopy were used to monitor the in situ growth of the nanoparticles and to corroborate the oxidation of the alcohol to caprylic acid. X-ray diffraction (XRD) and transmission electron microscopy (TEM) served to find the size and shape of the nanoparticles. It was found that the temperature used and the reagents proportions were appropriated to produce silver nanoparticles. A growth mechanism was proposed including the formation of silver carboxylates as an intermediate step of the reaction. As a systematic use of oleic acid, we could observe that a higher concentration of this capping agent led to smaller and more homogenous nanoparticles, less than 5nm in size.

Numerical experimentation for the optimal design of reinforced rectangular concrete beams for singly reinforced sections

Abstract: This paper presents a model for the optimal design of reinforced rectangular concrete beams for singly reinforced sections. It develops an analytical approach to the problem, based on a criterion of minimum cost and minimum weight design with a reduced number of design variables. Representative examples are presented to illustrate the applicability of the formulation in accordance with building code requirements for structural concrete (ACI 318S-13), including the comments on the standards. A comparison is made between the optimal design solution and current design practice for reinforced rectangular concrete beams. The optimal solution for the design of reinforced rectangular concrete beams shows clearly that significant savings can be made in the costs of the construction materials used – i.e. reinforcement steel and concrete. In addition, the problem formulation can be applied using a nonlinear mathematical programming format.

Modeling waste management in a bioethanol supply chain: A system dynamics approach

Abstract: This paper presents a model and simulations, which was built with a System Dynamics methodology applied to waste management in the bioethanol supply chain in Colombia. The stages of the supply chain used were cane planting, production and the distribution process. The residues taken into account were bagasse and vinasse. Moreover, four simulation scenarios were performed in which the values of variables modified management strategies. The installed bioethanol production capacity was increased to observe the evolution of increased waste generation evaluated. The initial conditions for the simulation were modified to represent a production of about 2,500,000 liters / day. This leads to an increased generation of vinasse of over 400 million liters on average in a month and around more than 1 million tones of bagasse. The results are used to estimate the impact of management strategies on the amount of waste generated in the production of bioethanol.

Forecasting of short-term flow freight congestion: A study case of Algeciras Bay Port (Spain)

Abstract: rd , 2014. Received in revised form: June 12 th , 2015. Accepted: December 10 th , 2015. Abstract The prediction of freight congestion (cargo peaks) is an important tool for decision making and it is this paper's main object of study. Forecasting freight flows can be a useful tool for the whole logistics chain. In this work, a complete methodology is presented in order to obtain the best model to predict freight congestion situations at ports. The prediction is modeled as a classification problem and different approaches are tested (k-Nearest Neighbors, Bayes classifier and Artificial Neural Networks). A panel of different experts (post-hoc methods of Friedman test) has been developed in order to select the best model. The proposed methodology is applied in the Strait of Gibraltar's logistics hub with a study case being undertaken in Port of Algeciras Bay. The results obtained reveal the efficiency of the presented models that can be applied to improve daily operations planning.

An adaptive controller applied to an anti–lock braking system laboratory

Abstract: Controlling an antilock braking system is difficult due to the existence of nonlinear dynamics and the uncertainty of its characteristics and parameters. To overcome these issues, we propose two controllers. The first controller is designed under the complete knowledge of the parameters hypothesis. Then, an adaptive nonlinear controller is designed using an estimate of the tire–road friction coefficient. This second controller is implemented in an ABS laboratory setup in order to test its performance, and the results show that the adaptive controller ensures the tracking of the desired reference and identifies the unknown parameter.

Prioritization of TQM practices in Brazilian medical device SMEs using Analytical Hierarchy Process (AHP)

Abstract: El proposito de este articulo es dar prioridad a Gestion de Calidad Total (GCT) practicas y examinar su importancia relativa en la implementacion de GCT en pequenas y medianas empresas (PYME) de la industria de dispositivos medicos, utilizando el metodo de Analytical Hierarchy Process (AHP). Modelacion matematica fue el metodo de investigacion adoptado. La eleccion de AHP tambien se baso en la necesidad de adquirir conocimientos de diferentes empresas. Algunas implicaciones se pueden destacar. Dos factores estrategicos (Sistema de Gestion de Calidad y Planificacion de la Calidad) y un factor tactico (Gestion de procesos) estan fuertemente correlacionados y indicados por los expertos como tener la mayor importancia. Por ultimo, el metodo AHP desarrollado en el presente estudio ha demostrado ser util para dar prioridad a las practicas relativas a la aplicacion de la GCT en las empresas de dispositivos medicos. Los resultados pueden ser informacion util para los administradores de dispositivos medicos que trabajan en las principales practicas con el fin de mejorar el rendimiento de la GCT.

Impact of a workplace exercise program on neck and shoulder segments in office workers

Abstract: Work-related musculoskeletal disorders are a common problem among office workers. The purpose of this study is to evaluate the impact of a workplace exercise program on neck and shoulder pain and flexibility in office workers. The workstation assessment was performed using Rapid Office Strain Assessment. Workers were assessed for pain pre- and post-implementation of the workplace exercise program using the Nordic Questionnaire for Musculoskeletal Symptoms, and for flexibility. The program lasted 3 months and entailed twice weekly sessions. The sample consisted of an intervention group (n = 30) and a control group (n = 8). The results suggest improvements in pain reduction and increased flexibility. The workers had less musculoskeletal pain at the end of the evaluation. The increase in flexibility between the evaluations was significant in the intervention group, though there were slight improvements there too.

Voltage sag assessment using an extended fault positions method and Monte Carlo simulation

Abstract: In this article, we propose an extended fault positions method combined with the Monte Carlo method to evaluate voltage sags. The distribution function SARFI is obtained by taking into account the randomness of (i) location of faults in lines, (ii) generation dispatch, and (iii) the prefault voltage. Voltage magnitudes are calculated with power flow, while noting changes in the generation dispatch, the load, and the topology of the area of vulnerability (AOV). The method is tested in the Atlantic coast area of the National Interconnected Power System of Colombia. The distribution of the number of voltage sags per year with the magnitude in bus bars and the impact of generation on the voltage sags are determined. With a higher number of plants dispatched, voltage sags caused by faults are less severe due to the robustness of the power system and the voltage support. Operation with coupled bars had a greater impact on voltage sags compared to uncoupled bars.

Evolución histórica de los vehiculos aereos no tripulados hasta la actualidad

Abstract: El origen y desarrollo de la aviacion no tripulada ha ido de la mano con el de la aviacion tripulada, empezando ambos desde practicamente el mismo punto. Al igual que en la aviacion tripulada convencional, en la aviacion no tripulada, las aplicaciones militares han sido el motor del desarrollo tecnologico y las aplicaciones potenciales de este tipo de sistemas se han desarrollado en gran parte del siglo XX y principios del siglo XXI. Finalmente, en los ultimos tiempos, estos sistemas estan experimentando un impresionante auge debido al descubrimiento de la gran variedad de operaciones comerciales y civiles que son capaces de realizar de manera muy eficaz. Este articulo pretende resumir la evolucion historica que estos sistemas han sufrido, para al final, presentar un breve analisis de las principales aplicaciones civiles / comerciales, tratando de ofrecer una vision general de los principales tipos de sistemas, su clasificacion y configuracion general Palabras claves: UAV, RPAS, no tripulado, tipos de aeronaves, avion no tripulado, vehiculo aereo no tripulado

Assessing the loss-of-insulation life of power transformers by estimating their historical loads and ambient temperature profiles using ANNs and Monte Carlo simulations

Abstract: A non-invasive method useful for asset management is to estimate the functional age of the insulating paper of the transformer that is caused by thermal aging. For this purpose, the hot-spot temperature profile must be assessed by means of some transformer characteristics, the historical load, ambient temperature profiles and a set of equations. In many in-service unit cases, the available data is incomplete. This paper proposes a method to deal with the lack of data. The method is based on the estimation of the historical load and ambient temperature profiles by using an artificial neural network and Monte Carlo simulations. The probable loss of total life percentage of a 30 MVA power transformer is obtained through the proposed method. Finally, the corresponding results for the assessed transformer, a model validation section and conclusions are presented.