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L.A. Ferreira
Faculty of Engineering, University of Porto, 4200-465 Porto, Portugal

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Journal article
Published: 22 December 2020 in Applied Sciences
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The growing competitiveness of the market, coupled with the increase in automation driven with the advent of Industry 4.0, highlights the importance of maintenance within organizations. At the same time, the amount of data capable of being extracted from industrial systems has increased exponentially due to the proliferation of sensors, transmission devices and data storage via Internet of Things. These data, when processed and analyzed, can provide valuable information and knowledge about the equipment, allowing a move towards predictive maintenance. Maintenance is fundamental to a company’s competitiveness, since actions taken at this level have a direct impact on aspects such as cost and quality of products. Hence, equipment failures need to be identified and resolved. Artificial Intelligence tools, in particular Machine Learning, exhibit enormous potential in the analysis of large amounts of data, now readily available, thus aiming to improve the availability of systems, reducing maintenance costs, and increasing operational performance and support in decision making. In this dissertation, Artificial Intelligence tools, more specifically Machine Learning, are applied to a set of data made available online and the specifics of this implementation are analyzed as well as the definition of methodologies, in order to provide information and tools to the maintenance area.

ACS Style

Diogo Cardoso; Luís Ferreira. Application of Predictive Maintenance Concepts Using Artificial Intelligence Tools. Applied Sciences 2020, 11, 18 .

AMA Style

Diogo Cardoso, Luís Ferreira. Application of Predictive Maintenance Concepts Using Artificial Intelligence Tools. Applied Sciences. 2020; 11 (1):18.

Chicago/Turabian Style

Diogo Cardoso; Luís Ferreira. 2020. "Application of Predictive Maintenance Concepts Using Artificial Intelligence Tools." Applied Sciences 11, no. 1: 18.

Article
Published: 16 February 2019 in Actuators
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This paper presents a case study and a model to predict maintenance interventions based on condition monitoring of diesel engine oil in urban buses by accompanying the evolution of its degradation. Many times, under normal functioning conditions, the properties of the lubricants, based on the intervals that manufacturers recommend for its change, are within normal and safety conditions. Then, if the lubricants’ oil condition is adequately accompanied, until reaching the degradation limits, the intervals of oil replacement can be enlarged, meaning that the buses’ availability increases, as well as their corresponding production time. Based on this assumption, a mathematical model to follow and to manage the oil condition is presented, in order to predict the next intervention with the maximum time between them, which means the maximum availability.

ACS Style

Hugo Raposo; José Torres Farinha; Inácio Fonseca; L. Andrade Ferreira. Condition Monitoring with Prediction Based on Diesel Engine Oil Analysis: A Case Study for Urban Buses. Actuators 2019, 8, 14 .

AMA Style

Hugo Raposo, José Torres Farinha, Inácio Fonseca, L. Andrade Ferreira. Condition Monitoring with Prediction Based on Diesel Engine Oil Analysis: A Case Study for Urban Buses. Actuators. 2019; 8 (1):14.

Chicago/Turabian Style

Hugo Raposo; José Torres Farinha; Inácio Fonseca; L. Andrade Ferreira. 2019. "Condition Monitoring with Prediction Based on Diesel Engine Oil Analysis: A Case Study for Urban Buses." Actuators 8, no. 1: 14.

Journal article
Published: 01 January 2019 in International Journal of Heavy Vehicle Systems
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The purpose of the paper is to discuss the application of econometric models to life-cycle cost (LCC) of an urban bus fleet with an emphasis on the maintenance costs. The practical results are compared with theoretical ones, which represent a good maintenance and functioning management. The influence of inflation ratio, as well as the price of fuel in the withdrawal time are evaluated. The paper analyses if there is a variation at the time of the vehicle replacement, obtained from several econometric methods namely the annual uniform income and minimisation of the average total cost with reduction to the present value. It also emphasises an eventual relation between the maintenance policy and the reserve fleet, and the relation between maintenance performance and time replacement of bus fleet. Finally, the paper analyses differences between replacement simulations from theoretical econometric models and the same ones applied to real data.

ACS Style

Hugo Raposo; José Torres Farinha; Luis Ferreira; Filipe Didelet. Economic life cycle of the bus fleet: a case study. International Journal of Heavy Vehicle Systems 2019, 26, 31 .

AMA Style

Hugo Raposo, José Torres Farinha, Luis Ferreira, Filipe Didelet. Economic life cycle of the bus fleet: a case study. International Journal of Heavy Vehicle Systems. 2019; 26 (1):31.

Chicago/Turabian Style

Hugo Raposo; José Torres Farinha; Luis Ferreira; Filipe Didelet. 2019. "Economic life cycle of the bus fleet: a case study." International Journal of Heavy Vehicle Systems 26, no. 1: 31.

Preprint
Published: 07 November 2018
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The paper presents a case study and a model for condition monitoring of Diesel engines’ oil of urban buses, through the accompaniment of the evolution of its degradation, with the objective to implement a predictive maintenance policy. Along time, because the usage, there is some decay in the lubricant properties. However, in normal functioning conditions, the lubricants properties, at the time the manufacturers recommend its changing, regardless of they are within the safety limits. Then, based on the accompaniment of the lubricants’ oil condition, the intervals of oil replacement can be enlarged what implies the availability increasing and the corresponding production increasing of the equipment. The model presented in this paper shows its potential to be spread to other types of equipment and organisations that want can implement similar maintenance policies, to achieve the best availability based on the real equipment health conditioning conditions

ACS Style

Hugo Raposo; José Torres Farinha; Inácio Fonseca; Luis Ferreira. Condition Monitoring with Prediction Based on Oil Engines of Urban Buses – A Case Study. 2018, 1 .

AMA Style

Hugo Raposo, José Torres Farinha, Inácio Fonseca, Luis Ferreira. Condition Monitoring with Prediction Based on Oil Engines of Urban Buses – A Case Study. . 2018; ():1.

Chicago/Turabian Style

Hugo Raposo; José Torres Farinha; Inácio Fonseca; Luis Ferreira. 2018. "Condition Monitoring with Prediction Based on Oil Engines of Urban Buses – A Case Study." , no. : 1.

Journal article
Published: 01 November 2018 in Journal of Minimally Invasive Gynecology
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ACS Style

G.A. Barison; A.A. Leal; L.A. Ferreira; V.A. Bezerra; R.A. Miziara; E. Zlotnik; M.T. Gomes. Laparoscopic Hysterectomy Performed in a Patient with Cystic Adenomyosis of the Cervix. Journal of Minimally Invasive Gynecology 2018, 25, S168 .

AMA Style

G.A. Barison, A.A. Leal, L.A. Ferreira, V.A. Bezerra, R.A. Miziara, E. Zlotnik, M.T. Gomes. Laparoscopic Hysterectomy Performed in a Patient with Cystic Adenomyosis of the Cervix. Journal of Minimally Invasive Gynecology. 2018; 25 (7):S168.

Chicago/Turabian Style

G.A. Barison; A.A. Leal; L.A. Ferreira; V.A. Bezerra; R.A. Miziara; E. Zlotnik; M.T. Gomes. 2018. "Laparoscopic Hysterectomy Performed in a Patient with Cystic Adenomyosis of the Cervix." Journal of Minimally Invasive Gynecology 25, no. 7: S168.

Article
Published: 10 April 2018 in Physical Review D
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We construct self-dual sectors for scalar field theories on a (2N+2)-dimensional Minkowski space-time with the target space being the 2N+1-dimensional sphere S2N+1. The construction of such self-dual sectors is made possible by the introduction of an extra functional in the action that renders the static energy and the self-duality equations conformally invariant on the (2N+1)-dimensional spatial submanifold. The conformal and target-space symmetries are used to build an ansatz that leads to an infinite number of exact self-dual solutions with arbitrary values of the topological charge. The five-dimensional case is discussed in detail, where it is shown that two types of theories admit self-dual sectors. Our work generalizes the known results in the three-dimensional case that lead to an infinite set of self-dual Skyrmion solutions.

ACS Style

Y. Amari; L. A. Ferreira. Self-dual Skyrmions on the spheres S2N+1. Physical Review D 2018, 97, 085006 .

AMA Style

Y. Amari, L. A. Ferreira. Self-dual Skyrmions on the spheres S2N+1. Physical Review D. 2018; 97 (8):085006.

Chicago/Turabian Style

Y. Amari; L. A. Ferreira. 2018. "Self-dual Skyrmions on the spheres S2N+1." Physical Review D 97, no. 8: 085006.

Case study and application
Published: 07 December 2017 in Public Transport
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The paper demonstrates the dependence of a fleet reserve of buses on the maintenance policy of the whole fleet, in particular, condition-based maintenance using a motor oil degradation analysis. The paper discusses an approach to evaluate the oil degradation and the prediction of the next value for one relevant oil variable. The methodology to evaluate the reserve fleet is based on bus availability, estimated through the mean time between failures and the mean time to repair ratios. Through the use of econometric models, it is possible to determine the most rational size of the reserve fleet.

ACS Style

Hugo Raposo; José Torres Farinha; Luis Ferreira; Diego Galar. Dimensioning reserve bus fleet using life cycle cost models and condition based/predictive maintenance: a case study. Public Transport 2017, 10, 169 -190.

AMA Style

Hugo Raposo, José Torres Farinha, Luis Ferreira, Diego Galar. Dimensioning reserve bus fleet using life cycle cost models and condition based/predictive maintenance: a case study. Public Transport. 2017; 10 (1):169-190.

Chicago/Turabian Style

Hugo Raposo; José Torres Farinha; Luis Ferreira; Diego Galar. 2017. "Dimensioning reserve bus fleet using life cycle cost models and condition based/predictive maintenance: a case study." Public Transport 10, no. 1: 169-190.

Conference paper
Published: 20 November 2017 in International Conference on Space Optics — ICSO 2010
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ACS Style

S. Abad; Francisco M. Araújo; F. Pedersen; M. A. Esteban; I. McKenzie; L. A. Ferreira; N. Karafolas; Naoto Kadowaki. Applications of FBG sensors on telecom satellites. International Conference on Space Optics — ICSO 2010 2017, 92 .

AMA Style

S. Abad, Francisco M. Araújo, F. Pedersen, M. A. Esteban, I. McKenzie, L. A. Ferreira, N. Karafolas, Naoto Kadowaki. Applications of FBG sensors on telecom satellites. International Conference on Space Optics — ICSO 2010. 2017; ():92.

Chicago/Turabian Style

S. Abad; Francisco M. Araújo; F. Pedersen; M. A. Esteban; I. McKenzie; L. A. Ferreira; N. Karafolas; Naoto Kadowaki. 2017. "Applications of FBG sensors on telecom satellites." International Conference on Space Optics — ICSO 2010 , no. : 92.

Journal article
Published: 01 November 2017 in Reliability Engineering & System Safety
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Currently we are facing an increasing trend of use of Unmanned Aerial Vehicles (UAV) in various activities both civilian and military. Although there is no legal framework for the operation of these systems, regulatory authorities require the demonstration of a safety level equivalent to manned aircraft. It is known the high vulnerability of the UAV not only to unexpected failures of their systems but also to the environment. The purpose of this paper is to present a safety assessment process modelling of a UAV by Petri Nets, that can be accepted by certifying bodies, considering the recommendations of STANAG 4671 UAV Airworthiness Requirements Specification (USAR) for analysis of fault conditions that lead to the most feared events. It is intended to show through the use of Petri Nets the frequency that the UAV enters the identified states described as most feared events; the ability of the UAV to react after being in a fault situation to the inputs of the operating crew in order to enhance trust and to facilitate the operation authorization process in UAV operations. The results obtained allowed to identify and to define critical areas and corrective actions that will lead to an acceptable level of risk for the regulatory authority.info:eu-repo/semantics/publishedVersio

ACS Style

P. Gonçalves; J. Sobral; L.A. Ferreira. Unmanned aerial vehicle safety assessment modelling through petri Nets. Reliability Engineering & System Safety 2017, 167, 383 -393.

AMA Style

P. Gonçalves, J. Sobral, L.A. Ferreira. Unmanned aerial vehicle safety assessment modelling through petri Nets. Reliability Engineering & System Safety. 2017; 167 ():383-393.

Chicago/Turabian Style

P. Gonçalves; J. Sobral; L.A. Ferreira. 2017. "Unmanned aerial vehicle safety assessment modelling through petri Nets." Reliability Engineering & System Safety 167, no. : 383-393.

Journal article
Published: 26 September 2017 in Management Systems in Production Engineering
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The maintenance planning corresponds to an approach that seeks to maximize the availability of equipment and, consequently, increase the levels of competitiveness of companies by increasing production times. This paper presents a maintenance planning based on operating variables (number of hours worked, duty cycles, number of revolutions) to maximizing the availability of operation of electrical motors. The reading of the operating variables and its sampling is done based on predetermined sampling cycles and subsequently is made the data analysis through time series algorithms aiming to launch work orders before reaching the variables limit values. This approach is supported by tools and technologies such as logical applications that enable a graphical user interface for access to relevant information about their Physical Asset HMI (Human Machine Interface), including the control and supervision by acquisition through SCADA (Supervisory Control And data acquisition) data, also including the communication protocols among different logical applications.

ACS Style

Francisco Rodrigues; Inácio Fonseca; José Torres Farinha; Luís Ferreira; Diego Galar. Electric Motors Maintenance Planning From Its Operating Variables. Management Systems in Production Engineering 2017, 25, 205 -216.

AMA Style

Francisco Rodrigues, Inácio Fonseca, José Torres Farinha, Luís Ferreira, Diego Galar. Electric Motors Maintenance Planning From Its Operating Variables. Management Systems in Production Engineering. 2017; 25 (3):205-216.

Chicago/Turabian Style

Francisco Rodrigues; Inácio Fonseca; José Torres Farinha; Luís Ferreira; Diego Galar. 2017. "Electric Motors Maintenance Planning From Its Operating Variables." Management Systems in Production Engineering 25, no. 3: 205-216.

Journals
Published: 20 September 2017 in Molecular BioSystems
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Dipolarity/polarizability of water in polymer mixtures may be additive, reduced or enhanced depending on the composition of the mixture. Solvent properties of water in aqueous solutions of polyethylene glycols of various molecular weights, l -proline, betaine, and a series of chlorides of varied concentrations are assayed using three solvatochromic dyes. The properties include solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity. These properties are also evaluated in mixtures of two polymers, polymer and osmolyte, and two osmolytes. It is shown that linear combinations of solvent dipolarity/polarizability and hydrogen bond donor acidity assayed in individual solutions of crowders strongly correlate with the effects of the crowders on the stability of various proteins and nucleic acids reported in the literature. The solvent properties of water in aqueous mixtures of two macromolecular crowders, two osmolytes, or mixtures of an osmolyte and a macromolecular crowder vary differently for various solvent properties. The overall effects of the two components in the mixture on a given solvent property of water may be additive, reduced or enhanced depending on the particular composition of the mixture. It is hypothesized that changes in the solvent properties of water are related to changes in the water hydrogen-bonding structuring. It is suggested that the observed crowder-induced changes in the solvent properties of water should be taken into account in theoretical considerations of crowding effects in biological systems.

ACS Style

L. A. Ferreira; V. N. Uversky; B. Y. Zaslavsky. Role of solvent properties of water in crowding effects induced by macromolecular agents and osmolytes. Molecular BioSystems 2017, 13, 2551 -2563.

AMA Style

L. A. Ferreira, V. N. Uversky, B. Y. Zaslavsky. Role of solvent properties of water in crowding effects induced by macromolecular agents and osmolytes. Molecular BioSystems. 2017; 13 (12):2551-2563.

Chicago/Turabian Style

L. A. Ferreira; V. N. Uversky; B. Y. Zaslavsky. 2017. "Role of solvent properties of water in crowding effects induced by macromolecular agents and osmolytes." Molecular BioSystems 13, no. 12: 2551-2563.

Journal article
Published: 12 June 2017 in Eksploatacja i Niezawodnosc - Maintenance and Reliability
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ACS Style

Hugo Raposo; José Torres Farinha; Luis Ferreira; Diego Galar. An integrated econometric model for bus replacement and determination of reserve fleet size based on predictive maintenance. Eksploatacja i Niezawodnosc - Maintenance and Reliability 2017, 19, 358 -368.

AMA Style

Hugo Raposo, José Torres Farinha, Luis Ferreira, Diego Galar. An integrated econometric model for bus replacement and determination of reserve fleet size based on predictive maintenance. Eksploatacja i Niezawodnosc - Maintenance and Reliability. 2017; 19 (3):358-368.

Chicago/Turabian Style

Hugo Raposo; José Torres Farinha; Luis Ferreira; Diego Galar. 2017. "An integrated econometric model for bus replacement and determination of reserve fleet size based on predictive maintenance." Eksploatacja i Niezawodnosc - Maintenance and Reliability 19, no. 3: 358-368.

Proceedings article
Published: 07 June 2017 in Safety and Reliability – Theory and Applications
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ACS Style

Daniel Gaspar; José Silva; Luis Ferreira; Marko Čepin; Radim Briš. The algorithm construction for randomness with censored data in simulation studies in reliability. Safety and Reliability – Theory and Applications 2017, 287 -287.

AMA Style

Daniel Gaspar, José Silva, Luis Ferreira, Marko Čepin, Radim Briš. The algorithm construction for randomness with censored data in simulation studies in reliability. Safety and Reliability – Theory and Applications. 2017; ():287-287.

Chicago/Turabian Style

Daniel Gaspar; José Silva; Luis Ferreira; Marko Čepin; Radim Briš. 2017. "The algorithm construction for randomness with censored data in simulation studies in reliability." Safety and Reliability – Theory and Applications , no. : 287-287.

Journal article
Published: 11 May 2017 in Journal of Clinical Pharmacy and Therapeutics
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Polymyxins were widely used until the 1960s; however, they fell into disfavour owing to their toxicity. The subsequent growth of infections caused by multidrug-resistant Gram-negative bacteria has led to renewed use of this class of antimicrobials in clinical practice. Acquired skin hyperpigmentation (SH) following intravenous polymyxin B treatment has been previously reported, but little is known about its pathogenesis, clinical course and treatment. To improve understanding of these issues, we conducted a prospective study of adult patients receiving intravenous polymyxin B treatment. Patients receiving intravenous polymyxin B treatment were followed throughout the course of treatment. Clinical, dermatoscopic, histologic and immunohistochemical skin properties of patients who presented with SH were studied. Skin hyperpigmentation was noted in 8% of patients (n=20/249); however, clinical, dermatoscopic, histologic and immunohistochemical examinations were performed only in three patients for whom the consent of relatives was obtained. Histologic and immunohistochemical findings showed an abundant melanocyte-pigmented dendritic network. Langerhans cells’ hyperplasia and dermal IL-6 overexpression were also found, presumably for an inflammatory process due to polymyxin B use. As polymyxin B causes the release of histamine, which is known for its melanogenic effect, it is possible that skin darkening is associated with this inflammatory mediator. These clinical and dermatoscopic findings contribute to a better understanding of how the pigmentary reaction manifests following intravenous polymyxin B treatment. We concluded that hyperpigmentation due to intravenous polymyxin B treatment is associated with an inflammatory process and subsequent melanocyte activation. Although the pigmentary disorder neither influences the outcome of the therapy nor warrants discontinuation of treatment, it nevertheless considerably affects the patient's quality of life.

ACS Style

K. P. H. Mattos; M. L. Cintra; I. R. Gouvêa; L. Á. Ferreira; P. E. N. F. Velho; P. Moriel. Skin hyperpigmentation following intravenous polymyxin B treatment associated with melanocyte activation and inflammatory process. Journal of Clinical Pharmacy and Therapeutics 2017, 42, 573 -578.

AMA Style

K. P. H. Mattos, M. L. Cintra, I. R. Gouvêa, L. Á. Ferreira, P. E. N. F. Velho, P. Moriel. Skin hyperpigmentation following intravenous polymyxin B treatment associated with melanocyte activation and inflammatory process. Journal of Clinical Pharmacy and Therapeutics. 2017; 42 (5):573-578.

Chicago/Turabian Style

K. P. H. Mattos; M. L. Cintra; I. R. Gouvêa; L. Á. Ferreira; P. E. N. F. Velho; P. Moriel. 2017. "Skin hyperpigmentation following intravenous polymyxin B treatment associated with melanocyte activation and inflammatory process." Journal of Clinical Pharmacy and Therapeutics 42, no. 5: 573-578.

Journal article
Published: 21 March 2017 in Eksploatacja i Niezawodnosc - Maintenance and Reliability
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ACS Style

Luis Ferreira; José Silva. Parameter estimation for Weibull distribution with right censored data using EM algorithm. Eksploatacja i Niezawodnosc - Maintenance and Reliability 2017, 19, 310 -315.

AMA Style

Luis Ferreira, José Silva. Parameter estimation for Weibull distribution with right censored data using EM algorithm. Eksploatacja i Niezawodnosc - Maintenance and Reliability. 2017; 19 (2):310-315.

Chicago/Turabian Style

Luis Ferreira; José Silva. 2017. "Parameter estimation for Weibull distribution with right censored data using EM algorithm." Eksploatacja i Niezawodnosc - Maintenance and Reliability 19, no. 2: 310-315.

Journal article
Published: 03 January 2017 in Aircraft Engineering and Aerospace Technology
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Purpose The purpose of this paper is to illustrate how to develop a methodology to set up an initial maintenance program for unmanned aerial vehicles (UAVs) following the well-known Steering Maintenance Group logic method (MSG-3) and taking into account safety concerns based on items probabilities of failure. That is why it is stated that maintenance program is based on reliability principles. Design/methodology/approach The proposed methodology follows the MSG-3 framework applied to civil aircraft but where the determination of each probability of failure is achieved applying a morphological analysis. These probabilities are then affected by some factors to calculate the adjusted values to the specific conditions (design, operation and environment) under which the system is expected to operate. Findings Main findings are related to the applicability of the morphological analysis on the developing of an initial maintenance program when there is a lack of data that disable the establishment of a coherent maintenance program. Research limitations/implications Limitations are related to the absence of a legislative framework consensual in Europe for certification of UAVs and the lack of data concerning UAVs failure modes, causes and their probability of failure. Practical implications The developed work and the methodology proposed may be useful for UAVs maintenance program engineers and technicians when developing new systems. Originality/value The originality is based on the use of morphological analysis for UAVs to determine the items probabilities of failure when there is a no-data problem. Based on the referred analysis, it is possible to create an initial maintenance program for UAVs.

ACS Style

Paula Gonçalves; José Sobral; Luis Ferreira. Establishment of an initial maintenance program for UAVs based on reliability principles. Aircraft Engineering and Aerospace Technology 2017, 89, 66 -75.

AMA Style

Paula Gonçalves, José Sobral, Luis Ferreira. Establishment of an initial maintenance program for UAVs based on reliability principles. Aircraft Engineering and Aerospace Technology. 2017; 89 (1):66-75.

Chicago/Turabian Style

Paula Gonçalves; José Sobral; Luis Ferreira. 2017. "Establishment of an initial maintenance program for UAVs based on reliability principles." Aircraft Engineering and Aerospace Technology 89, no. 1: 66-75.

Journal article
Published: 01 January 2017 in Physical Chemistry Chemical Physics
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Distances between the signatures of salt effects on water solvent features depend on static polarizability of the anion and water structural entropy.

ACS Style

L. A. Ferreira; V. N. Uversky; B. Y. Zaslavsky. Effects of the Hofmeister series of sodium salts on the solvent properties of water. Physical Chemistry Chemical Physics 2017, 19, 5254 -5261.

AMA Style

L. A. Ferreira, V. N. Uversky, B. Y. Zaslavsky. Effects of the Hofmeister series of sodium salts on the solvent properties of water. Physical Chemistry Chemical Physics. 2017; 19 (7):5254-5261.

Chicago/Turabian Style

L. A. Ferreira; V. N. Uversky; B. Y. Zaslavsky. 2017. "Effects of the Hofmeister series of sodium salts on the solvent properties of water." Physical Chemistry Chemical Physics 19, no. 7: 5254-5261.

Journal article
Published: 01 December 2016 in Journal of Building Engineering
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ACS Style

José Sobral; L.A. Ferreira. Availability of fire pumping systems under periodic inspection. Journal of Building Engineering 2016, 8, 285 -291.

AMA Style

José Sobral, L.A. Ferreira. Availability of fire pumping systems under periodic inspection. Journal of Building Engineering. 2016; 8 ():285-291.

Chicago/Turabian Style

José Sobral; L.A. Ferreira. 2016. "Availability of fire pumping systems under periodic inspection." Journal of Building Engineering 8, no. : 285-291.

Journal article
Published: 25 May 2016 in The Aeronautical Journal
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The certification process plays an important role in aircraft safety and operation, assuring a high degree of confidence in accomplishing their objectives. Unfortunately, in the field of Unmanned Aerial Vehicles (UAV), there is not enough information to enable an acceptable decision-making process regarding compliance with certification requirements. To overcome this limitation, a methodology was developed based on morphological analysis principle, taking advantage of the knowledge and behaviour of similar items and affecting them with the necessary corrective factor in accordance to the differences in design, operation and environment. The objective is to establish an initial maintenance program as an important requirement to operate any kind of aircraft. This paper presents the methodology and the obtained results for a UAV under development concerning the establishment of a maintenance program regarding its certification process.

ACS Style

P. Goncalves; José Sobral; Luis Ferreira. Reliability database for unmanned aerial vehicles based on morphological analysis. The Aeronautical Journal 2016, 120, 1262 -1274.

AMA Style

P. Goncalves, José Sobral, Luis Ferreira. Reliability database for unmanned aerial vehicles based on morphological analysis. The Aeronautical Journal. 2016; 120 (1230):1262-1274.

Chicago/Turabian Style

P. Goncalves; José Sobral; Luis Ferreira. 2016. "Reliability database for unmanned aerial vehicles based on morphological analysis." The Aeronautical Journal 120, no. 1230: 1262-1274.

Preprint
Published: 12 August 2015
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We evaluate the gauge invariant, dynamically conserved charges, recently obtained from the integral form of the Yang-Mills equations, for the BPS multi-dyon solutions of a Yang-Mills-Higgs theory associated to any compact semi-simple gauge group G. Those charges are shown to correspond to the eigenvalues of the next-to-leading term of the asymptotic form of the Higgs field at spatial infinity, and so coinciding with the usual topological charges of those solutions. Such results show that many of the topological charges considered in the literature are in fact dynamical charges, which conservation follows from the global properties of classical Yang-Mills theories encoded into their integral dynamical equations. The conservation of those charges can not be obtained from the differential form of Yang-Mills equations.

ACS Style

C. P. Constantinidis; L. A. Ferreira; G. Luchini. A remark on the asymptotic form of BPS multi-dyon solutions and their conserved charges. 2015, 1 .

AMA Style

C. P. Constantinidis, L. A. Ferreira, G. Luchini. A remark on the asymptotic form of BPS multi-dyon solutions and their conserved charges. . 2015; ():1.

Chicago/Turabian Style

C. P. Constantinidis; L. A. Ferreira; G. Luchini. 2015. "A remark on the asymptotic form of BPS multi-dyon solutions and their conserved charges." , no. : 1.