Diogo Matos

Modeling synchronous reluctance motors including saturation, iron losses and mechanical losses

The correct modeling and control of synchronous reluctance motors (SynRMs) requires a very good parameter identification. Accordingly, a simple experimental off-line approach for the calculation of the viscous friction coefficient, constant friction load, iron loss resistance and direct/quadrature inductances is presented in this paper. The iron loss resistance and the direct/quadrature inductances were introduced in the model as lookup tables. The motor behavior under vector control is analyzed considering both saturation and iron losses. Simulation results of a vector-controlled 2.2 kW SynRM are compared with experimental tests in order to show the effectiveness and accuracy of the proposed parameter identification methods.

Performance evaluation of synchronous reluctance motor drives under inverter fault conditions

This paper presents a performance analysis of a synchronous reluctance motor (SynRM) drive under different faulty operating conditions. Considering the voltage source inverter, single power switch open-circuit faults and single phase open-circuit failures are introduced and their effects are analyzed regarding the performance evaluation of the SynRM. The comparison of normal and faulty operating conditions is based on the analysis of certain key parameters such as motor efficiency, power factor, electromagnetic torque, currents RMS values, total waveform distortion values, and total waveform oscillation values, resulting from the computational simulations.

Performance of a synchronous reluctance motor drive with a fault-tolerant three-level neutral point clamped inverter

This paper presents a performance analysis of a synchronous reluctance motor (SynRM) drive under different fault-tolerant modulation strategies. The analysis comprises different single power switches short-circuit faults in a three-level NPC converter controlled by a space vector modulation (SVM) technique. The comparison of the normal and two post-fault operating conditions is based on the analysis of certain parameters such as the motor efficiency, power factor, electromagnetic torque, currents RMS values, total waveform distortion values, and total waveform oscillation values, resulting from the computational simulations.

Fault Analysis of Three-Level NPC Inverters in Synchronous Reluctance Motor Drives

A performance analysis of a synchronous reluctance motor (SynRM) drive, operating under different fault conditions, with a three-level NPC inverter, controlled by a seven-segment Space Vector Modulation (SVM) technique, is presented in this paper. Considering the voltage source inverter, open-circuit faults of different types are introduced and their effects are studied regarding the SynRM and the inverter performance evaluation. The healthy and faulty operating conditions comparison will take into account the evaluation of some variables, such as the motor power factor, electromagnetic torque, efficiency, total waveform distortion values, currents RMS values, and total waveform oscillation values, obtained from simulation results.

VASCULITE CUTÂNEA LEUCOCITOCLÁSICA INDUZIDA PELO PROPILTIOURACILO

Propylthiouracil (PTU) is widely used in the treatment of Hyperthyroidism. Usually well tolerated, it is though associated with antineutrophil cytoplasmic antibodies (ANCA) and, less frequently, with late-onset ANCA positive vasculitis. The authors describe the clinical case of a 45-year-old female patient with Graves’ disease for which she was being treated with PTU since 3 years before, who developed an ANCA-positive cutaneous leukocytoclastic vasculitis without systemic involvement. Initially seen as idiopathic the vasculitis was posteriorly associated with PTU. The drug was discontinued with a progressive and maintained recovery. The patient remains asymptomatic with 3 years of follow-up.

MELANOMA MALIGNO: ANÁLISE RETROSPECTIVA 2006-2013

Introduction: The incidence of malignant melanoma has been rising. Therefore, the knowledge of its prevalence is very important. The authors intended to study the prevalence, demographic variables and the clinical features of the malignant melanoma diagnosed in their department.Material and methods: A retrospective study of the MM diagnosed between 2006 and 2013 was performed. The data was statistically an analysed.Results: three hundred and forty one malignant melanomas were diagnosed in 302 patients, 189 in women. The average annual growth rate was 8.57%, with 27 MM in 2006 and 48 in 2013. The older age groups predominated. Overall the trunk was the most frequent location. The Breslow thickness averaged 1.18mm. A statistically significant increase in the proportion of thin malignant melanomas ( 2mm remained unaltered. Nodal disease (stage III) was evident in 36 patients. Only two patients had metastatic disease (stage IV).Discussion: The number of malignant melanomas diagnosed grew above the reported national and international incidence growth. The average Breslow thickness, above 1 mm, remains high. Nonetheless, the proportional increase in malignant melanomas <1mm points towards a positive evolution.Conclusion: Our data, though representing a limited population, may lead to conclusions on the efficacy of the prevention strategies regarding malignant melanoma.Introduction: The incidence of malignant melanoma has been rising. Therefore, the knowledge of its prevalence is very important. The authors intended to study the prevalence, demographic variables and the clinical features of the malignant melanoma diagnosed in their department. Material and methods: A retrospective study of the MM diagnosed between 2006 and 2013 was performed. The data was statistically an analysed. Results: three hundred and forty one malignant melanomas were diagnosed in 302 patients, 189 in women. The average annual growth rate was 8.57%, with 27 MM in 2006 and 48 in 2013. The older age groups predominated. Overall the trunk was the most frequent location. The Breslow thickness averaged 1.18mm. A statistically significant increase in the proportion of thin malignant melanomas ( 2mm remained unaltered. Nodal disease (stage III) was evident in 36 patients. Only two patients had metastatic disease (stage IV). Discussion: The number of malignant melanomas diagnosed grew above the reported national and international incidence growth. The average Breslow thickness, above 1 mm, remains high. Nonetheless, the proportional increase in malignant melanomas <1mm points towards a positive evolution. Conclusion: Our data, though representing a limited population, may lead to conclusions on the efficacy of the prevention strategies regarding malignant melanoma.

RETALHO NASOGENIANO V-Y DE AVANÇO - DUAS VARIANTES ÚTEIS NA RECONSTRUÇÃO NASAL

The V-Y advancement flap is perfectly adaptable to the nasolabial fold and is extremely useful in that location. Apart from its classic application as vertical advancement flap, multiple variants have been described. The authors describe two case reports with two different applications of this flap, which represent two different degrees of technical complexity. In the first case, a 64-year-old male has a left paranasal basal cell carcinoma that was excised, resulting in a 2 cm width surgical defect. The second case mentions a 61-year-old male with a basal cell carcinoma of the nasal ala, which excision resulted in a defect affecting the full-thickness of part of the nasal ala and the perialar portion of the nasolabial fold. The details of the surgical reconstructions by means of a nasolabial fold- centered V-Y advancement flap, in the first case, and a turnover advancement flap centered in the nasolabial fold, in the second case, will be discussed.

RETALHO NASOGENIANO DE TRANSPOSIÇÃO COM PEDÍCULO SUPERIOR - PRINCÍPIOS E APLICAÇÕES FUNDAMENTAIS

O Retalho nasogeniano de transposicao (RNGT) com pediculo superior tem diversas indicacoes na reconstrucao de defeitos cirurgicos da area centro-facial. Para alem da sua indicacao classica, que permite reconstruir defeitos da asa do nariz, o RNGT e uma alternativa para todas as subunidades do nariz, excepto as mais superiores, inclusivamente para a ponta e defeitos de toda a espessura da asa. Adicionalmente permite reconstruir defeitos da regiao infraorbitaria. E um retalho muito seguro e de execucao relativamente facil, com uma baixa ocorrencia de complicacoes, desde que sejam cumpridos alguns principios fundamentais.

CARCINOMA DUCTAL ÉCRINO

Ductal eccrine carcinoma is a rare and aggressive skin cancer. Its diagnosis implies the exclusion of a primary adenocarcinoma located elsewhere with cutaneous metastization, as the histological and immunohistochemical analysis are not sufficient by themselves. We report the clinical case of a 75-year-old male with a 3 cm width tumor located on the right hemiface, which was excised and whose histology and immunohistochemistry pointed towards an eccrine ductal carcinoma. The complementary investigation showed multiple pleural and pulmonary nodules, as well as neoplastic involvement of the dorsal and lumbar vertebral column. Their histological and immnunohistochemical examination, supplement with the absence of imagiologic findings suggesting a primary tumor in another location, allowed the diagnosis of a metastatic eccrine ductal carcinoma. The patient died 6 months after the initial consultation.

PLASMOCITOMAS CUTÂNEOS METASTÁTICOS

Diogo Matos1, João Alves1, Hugo Barreiros2, Ricardo Coelho3, Elvira Bártolo4, Fernanda Vargas5 1Interno do Internato Complementar de Dermatologia e Venereologia/ Resident, Dermatology and Venereology, Hospital Garcia de Orta, Almada, Portugal 2Dermatologista/Dermatologist, Centro Dermatologia Epidermis, Instituto CUF, Porto, Portugal 3Assistente Hospitalar de Dermatologia e Venereologia/Consultant, Dermatology and Venereology, Hospital Garcia de Orta, Almada, Portugal 4Chefe de Serviço de Dermatologia e Venereologia, Directora do Serviço de Dermatologia e Venereologia/ Chief and Head of Dermatology and Venereology Department Hospital Garcia de Orta, Almada, Portugal 5Assistente Hospitalar de Hematologia/Consultant, Haematology, Hospital Garcia de Orta, Almada, Portugal