Student's academic efficacy or Inefficacy? an example on how to evaluate the psychometric properties of a measuring instrument and evaluate the effects of item wording

This study evaluated the effect of item inversion on the construct validity and reliability of psychometric scales and proposed a theoretical framework for the evaluation of the psychometric properties of data gathered with psychometric instruments. To this propose, we used the Maslach Burnout Inventory, which is the most used psychometric inventory to measure burnout in different professional context (Students, Teachers, Police, Doctors, Nurses, etc…). The version of the MBI used was the MBI-Student Survey (MBI-SS). This inventory is composed of three key dimensions: Exhaustion, Cynicism and Professional Efficacy. The two first dimensions—which have positive formulated items—are moderate to strong positive correlated, and show moderate to strong negative correlations with the 3rd dimension—which has negative formulated items. We tested the hypothesis that, in college students, formulating the 3rd dimension of burnout as Inefficacy (reverting the negatively worded items in the Efficacy dimension) improves the correlation of the 3rd dimension with the other two dimensions, improves its internal consistency, and the overall MBI-SS’ construct validity and reliability. Confirmatory factor analysis results, estimated by Maximum Likelihood, revealed adequate factorial fit for both forms of the MBI-SS (with Efficacy) vs. the MBI-SSi (with Inefficacy). Also both forms showed adequate convergent and discriminant related validity. However, reliability and convergent validity were higher for the MBI-SSi. There were also stronger (positive) correlations between the 3 factors in MBI-SSi than the ones observed in MBI-SS. Results show that positively rewording of the 3rd dimension of the MBI-SS improves its validity and reliability. We therefore propose that the 3rd dimension of the MBI-SS should be named Professional Inefficacy and its items should be positively worded.

Development and Validation of a Clinical Scale for the Evaluation of Forearm Skin Photoaging

Background: Despite the focus on facial photoaging ratings, there are few classifications developed for forearm skin aging assessment.Objective: To develop and validate a clinical scale for the evaluation of forearm skin aging.Methods: Three clinical dermatology faculty members selected, discussed, and appraised the main signs of forearm photoaging. The validation of the resulting scale was performed by 5 assessors who were previously trained to classify 102 photographs of forearms with different degrees of aging. Retests were performed in 15 days.Results: There was significant correlation between the selected variables and the subjective global aging scale. The developed scale showed high internal consistency (Cronbach's alpha = 0.87) and high correlation with the global photoaging scale (rho = 0.92). Inter- and intraobserver final scores showed high agreement.Conclusion: A validated clinical photoaging scale for forearms with internal consistency, reliability, and validity was developed.

Controle das propriedades dinâmicas de sistemas mecânicos através da utilização de molas inteligentes

Pós-graduação em Engenharia Mecânica - FEIS

Prediction of apparent protein digestibility of ingredients and diets by in vitro pH-stat degree of protein hydrolysis with species-specific enzymes for juvenile Pacific white shrimp Litopenaeus vannamei

Aquafeed production faces global issues related to availability of feed ingredients. Feed manufacturers require greater flexibility in order to develop nutritional and cost-effective formulations that take into account nutrient content and availability of ingredients. The search for appropriate ingredients requires detailed screening of their potential nutritional value and variability at the industrial level. In vitro digestion of feedstuffs by enzymes extracted from the target species has been correlated with apparent protein digestibility (APD) in fish and shrimp species. The present study verified the relationship between APD and in vitro degree of protein hydrolysis (DH) with Litopenaeus vannamei hepatopancreas enzymes in several different ingredients (n = 26): blood meals, casein, corn gluten meal, crab meal, distiller`s dried grains with solubles, feather meal, fish meals, gelatin, krill meals, poultry by-product meal, soybean meals, squid meals and wheat gluten. The relationship between APD and DH was further verified in diets formulated with these ingredients at 30% inclusion into a reference diet. APD was determined in vivo (30.1 +/- 0.5 degrees C, 32.2 +/- 0.4%.) with juvenile L vannamei (9 to 12 g) after placement of test ingredients into a reference diet (35 g kg(-1) CP: 8.03 g kg(-1) lipid; 2.01 kcal g(-1)) with chromic oxide as the inert marker. In vitro DH was assessed in ingredients and diets with standardized hepatopancreas enzymes extracted from pond-reared shrimp. The DH of ingredients was determined under different assay conditions to check for the most suitable in vitro protocol for APD prediction: different batches of enzyme extracts (HPf5 or HPf6), temperatures (25 or 30 degrees C) and enzyme activity (azocasein): crude protein ratios (4 U: 80 mg CP or 4 U: 40 mg CP). DH was not affected by ingredient proximate composition. APD was significantly correlated to DH in regressions considering either ingredients or diets. The relationships between APD and DH of the ingredients could be suitably adjusted to a Rational Function (y = (a + bx)/(1 + cx + dx2), n = 26. Best in vitro APD predictions were obtained at 25 degrees C, 4 U: 80 mg CP both for ingredients (R(2) = 0.86: P = 0.001) and test diets (R(2) = 0.96; P = 0.007). The regression model including all 26 ingredients generated higher prediction residuals (i.e., predicted APD - determined APD) for corn gluten meal, feather meal. poultry by-product meal and krill flour. The remaining test ingredients presented mean prediction residuals of 3.5 points. A model including only ingredients with APD>80% showed higher prediction precision (R(2) = 0.98: P = 0.000004; n = 20) with average residual of 1.8 points. Predictive models including only ingredients from the same origin (e.g., marine-based, R(2) = 0.98; P = 0.033) also displayed low residuals. Since in vitro techniques have been usually validated through regressions against in vivo APD, the DH predictive capacity may depend on the consistency of the in vivo methodology. Regressions between APD and DH suggested a close relationship between peptide bond breakage by hepatopancreas digestive proteases and the apparent nitrogen assimilation in shrimp, and this may be a useful tool to provide rapid nutritional information. (C) 2009 Elsevier B.V. All rights reserved.

Carbon monoxide and related trace gases and aerosols over the Amazon Basin during the wet and dry seasons

We present the results of airborne measurements of carbon monoxide (CO) and aerosol particle number concentration (CN) made during the Balan double dagger o Atmosf,rico Regional de Carbono na Amazonia (BARCA) program. The primary goal of BARCA is to address the question of basin-scale sources and sinks of CO2 and other atmospheric carbon species, a central issue of the Large-scale Biosphere-Atmosphere (LBA) program. The experiment consisted of two aircraft campaigns during November-December 2008 (BARCA-A) and May-June 2009 (BARCA-B), which covered the altitude range from the surface up to about 4500 m, and spanned most of the Amazon Basin. Based on meteorological analysis and measurements of the tracer, SF6, we found that airmasses over the Amazon Basin during the late dry season (BARCA-A, November 2008) originated predominantly from the Southern Hemisphere, while during the late wet season (BARCA-B, May 2009) low-level airmasses were dominated by northern-hemispheric inflow and mid-tropospheric airmasses were of mixed origin. In BARCA-A we found strong influence of biomass burning emissions on the composition of the atmosphere over much of the Amazon Basin, with CO enhancements up to 300 ppb and CN concentrations approaching 10 000 cm(-3); the highest values were in the southern part of the Basin at altitudes of 1-3 km. The Delta CN/Delta CO ratios were diagnostic for biomass burning emissions, and were lower in aged than in fresh smoke. Fresh emissions indicated CO/CO2 and CN/CO emission ratios in good agreement with previous work, but our results also highlight the need to consider the residual smoldering combustion that takes place after the active flaming phase of deforestation fires. During the late wet season, in contrast, there was little evidence for a significant presence of biomass smoke. Low CN concentrations (300-500 cm(-3)) prevailed basinwide, and CO mixing ratios were enhanced by only similar to 10 ppb above the mixing line between Northern and Southern Hemisphere air. There was no detectable trend in CO with distance from the coast, but there was a small enhancement of CO in the boundary layer suggesting diffuse biogenic sources from photochemical degradation of biogenic volatile organic compounds or direct biological emission. Simulations of CO distributions during BARCA-A using a range of models yielded general agreement in spatial distribution and confirm the important contribution from biomass burning emissions, but the models evidence some systematic quantitative differences compared to observed CO concentrations. These mismatches appear to be related to problems with the accuracy of the global background fields, the role of vertical transport and biomass smoke injection height, the choice of model resolution, and reliability and temporal resolution of the emissions data base.

Architectures, stability and optimization for clock distribution networks

Synchronous telecommunication networks, distributed control systems and integrated circuits have its accuracy of operation dependent on the existence of a reliable time basis signal extracted from the line data stream and acquirable to each node. In this sense, the existence of a sub-network (inside the main network) dedicated to the distribution of the clock signals is crucially important. There are different solutions for the architecture of the time distribution sub-network and choosing one of them depends on cost, precision, reliability and operational security. In this work we expose: (i) the possible time distribution networks and their usual topologies and arrangements. (ii) How parameters of the network nodes can affect the reachability and stability of the synchronous state of a network. (iii) Optimizations methods for synchronous networks which can provide low cost architectures with operational precision, reliability and security. (C) 2011 Elsevier B. V. All rights reserved.

T-3 Rapidly Increases SLC2A4 Gene Expression and GLUT4 Trafficking to the Plasma Membrane in Skeletal Muscle of Rat and Improves Glucose Homeostasis

Background: Glucose transporter 4 (GLUT4) is highly expressed in muscle and fat tissue, where triiodothyronine (T-3) induces solute carrier family 2 facilitated glucose transporter member 4 (SLC2A4) gene transcription. T-3 was also shown to rapidly increase glucose uptake in myocytes exposed to cycloheximide, indicating that it might act nongenomically to regulate GLUT4 availability. We tested this hypothesis by evaluating, in thyroidectomized rats (Tx rats), the acute and/or chronic T-3 effects on GLUT4 mRNA expression and polyadenylation, protein content, and trafficking to the plasma membrane (PM) in skeletal muscle, as well as on blood glucose disappearance rate (kITT) after insulin administration. Methods: Rats were surgically thyroidectomized and treated with T-3 (0.3 to 100 mu g/100 g body weight) from 10 minutes to 5 days, and killed thereafter. Sham-operated (SO) rats were used as controls. Total RNA was extracted from the skeletal muscles (soleus [SOL] and extensorum digitalis longus [EDL]) and subjected to Northern blotting analysis using rat GLUT4 cDNA probe. Total protein was extracted and subjected to specific centrifugations for subcellular fractionation, and PM as well as microsomal (M) fractions were subjected to Western blotting analysis, using anti-GLUT4 antiserum as a probe. GLUT4 mRNA polyadenylation was examined by a rapid amplification of cDNA ends-poly(A) test (RACE-PAT). Results: Thyroidectomy reduced skeletal muscle GLUT4 mRNA, mRNA poly(A) tail length, protein content, and trafficking to the PM, as well as the kITT. The acute T-3 treatment rapidly (30 minutes) increased all these parameters compared with Tx rats. The 5-day T-3 treatment increased GLUT4 mRNA and protein expression, and restored GLUT4 trafficking to the PM and kITT to SO values. Conclusions: The results presented here show for the first time that, in parallel to its transcriptional action on the SLC2A4 gene, T-3 exerts a rapid post-transcriptional effect on GLUT4 mRNA polyadenylation, which might increase transcript stability and translation efficiency, leading to the increased GLUT4 content and availability to skeletal muscle, as well as on GLUT4 translocation to the PM, improving the insulin sensitivity, as shown by the kITT.

Inter-rater reliability of the evaluation of muscular chains associated with posture alterations in scoliosis

Background: In the Global postural re-education (GPR) evaluation, posture alterations are associated with anterior or posterior muscular chain impairments. Our goal was to assess the reliability of the GPR muscular chain evaluation. Methods: Design: Inter-rater reliability study. Fifty physical therapists (PTs) and two experts trained in GPR assessed the standing posture from photographs of five youths with idiopathic scoliosis using a posture analysis grid with 23 posture indices (PI). The PTs and experts indicated the muscular chain associated with posture alterations. The PTs were also divided into three groups according to their experience in GPR. Experts' results (after consensus) were used to verify agreement between PTs and experts for muscular chain and posture assessments. We used Kappa coefficients (K) and the percentage of agreement (%A) to assess inter-rater reliability and intra-class coefficients (ICC) for determining agreement between PTs and experts. Results: For the muscular chain evaluation, reliability was moderate to substantial for 12 PI for the PTs (% A: 56 to 82; K: 0.42 to 0.76) and perfect for 19 PI for the experts. For posture assessment, reliability was moderate to substantial for 12 PI for the PTs (% A > 60%; K: 0.42 to 0.75) and moderate to perfect for 18 PI for the experts (% A: 80 to 100; K: 0.55 to 1.00). The agreement between PTs and experts was good for most muscular chain evaluations (18 PI; ICC: 0.82 to 0.99) and PI (19 PI; ICC: 0.78 to 1.00). Conclusions: The GPR muscular chain evaluation has good reliability for most posture indices. GPR evaluation should help guide physical therapists in targeting affected muscles for treatment of abnormal posture patterns.

TRANSLATION AND CULTURAL ADAPTATION OF THE GLOBAL APPRAISAL OF INDIVIDUAL NEEDS - INITIAL

The objective of this study was to perform the translation on and cultural adaptation of the Global Appraisal of Individual Needs - Initial instrument, and calculate its content validity index. This is a methodological study designed for the cultural adaptation of the instrument. The instrument was translated into Portuguese in two versions that originated the synthesis of the translations, which were then submitted to the evaluation of four judges, experts in the field of alcohol and other drugs. After the suggested changes were made, the instrument was back-translated and resubmitted to the judges and authors of the original instrument, resulting in the final version of the instrument, Avaliacao Global das Necessidades Individuais - Inicial. The content validity index of the instrument was 0.91, considered valid according to the literature. The instrument Avaliacao Global das Necessidades Individuais - Inicial was culturally adapted to the Portuguese language spoken in Brazil; however, it was not submitted to tests with the target population, which suggests further studies should be performed to test its reliability and validity.

Translation and Cross-cultural Adaptation of the Lower Extremity Functional Scale Into a Brazilian Portuguese Version and Validation on Patients With Knee Injuries

STUDY DESIGN: Clinical measurement. OBJECTIVE: To translate and culturally adapt the Lower Extremity Functional Scale (LEFS) into a Brazilian Portuguese version, and to test the construct and content validity and reliability of this version in patients with knee injuries. BACKGROUND: There is no Brazilian Portuguese version of an instrument to assess the function of the lower extremity after orthopaedic injury. METHODS: The translation of the original English version of the LEFS into a Brazilian Portuguese version was accomplished using standard guidelines and tested in 31 patients with knee injuries. Subsequently, 87 patients with a variety of knee disorders completed the Brazilian Portuguese LEES, the Medical Outcomes Study 36-Item Short-Form Health Survey, the Western Ontario and McMaster Universities Osteoarthritis Index, and the International Knee Documentation Committee Subjective Knee Evaluation Form and a visual analog scale for pain. All patients were retested within 2 days to determine reliability of these measures. Validation was assessed by determining the level of association between the Brazilian Portuguese LEFS and the other outcome measures. Reliability was documented by calculating internal consistency, test-retest reliability, and standard error of measurement. RESULTS: The Brazilian Portuguese LEES had a high level of association with the physical component of the Medical Outcomes Study 36-Item Short-Form Health Survey (r = 0.82), the Western Ontario and McMaster Universities Osteoarthritis Index (r = 0.87), the International Knee Documentation Committee Subjective Knee Evaluation Form (r = 0.82), and the pain visual analog scale (r = -0.60) (all, P<.05). The Brazilian Portuguese LEES had a low level of association with the mental component of the Medical Outcomes Study 36-Item Short-Form Health Survey (r = 0.38, P<.05). The internal consistency (Cronbach alpha = .952) and test-retest reliability (intraclass correlation coefficient = 0.957) of the Brazilian Portuguese version of the LEES were high. The standard error of measurement was low (3.6) and the agreement was considered high, demonstrated by the small differences between test and retest and the narrow limit of agreement, as observed in Bland-Altman and survival-agreement plots. CONCLUSION: The translation of the LEFS into a Brazilian Portuguese version was successful in preserving the semantic and measurement properties of the original version and was shown to be valid and reliable in a Brazilian population with knee injuries. J Ort hop Sports Phys Ther 2012;42(11):932-939, Epub 9 October 2012. doi:10.2519/jospt.2012.4101

Enhanced Morbidity of Pectoralis Major Myocutaneous Flap Used for Salvage after Previously Failed Oncological Treatment and Unsuccessful Reconstructive Head and Neck Surgery

Introduction. The reconstruction of complex cervicofacial defects arising from surgical treatment for cancer is a real challenge for head and neck surgeons, especially in salvage reconstruction surgery and/or failed previous reconstruction. The pectoralis major myocutaneous flap (PMMF) has been widely used in these specific situations due to its reliability and low rate of failure or complications. Objectives. Identify factors that determine complications and influence the final outcome of the reconstructions with PMMF in salvage cancer surgery or in salvage reconstruction. Methods. A cross-sectional study design was used to evaluate a sample including 17 surgical patients treated over a period of ten years that met the inclusion criteria. Results. Reconstruction was successful in 13 cases (76.5%), with two cases of partial flap loss and no case of total loss. Complications occurred in 13 cases (76.5%) and were specifically related to the flap in nine instances (52.9%). An association was identified between the development of major complications and reconstruction of the hypopharynx (P = 0.013) as well as in patients submitted to surgery in association with radiation therapy as a previous cancer treatment (P = 0.002). The former condition is also associated with major reconstruction failure (P = 0.018). An even lower incidence of major complications was noted in patients under the age of 53 (P = 0.044). Conclusion. Older patients, with hypopharyngeal defects and submitted to previous surgery plus radiation therapy, presented a higher risk of complications and reconstruction failure with PMMF.

Cross-cultural adaptation and psychometric properties of the Brazilian-Portuguese version of the Duke Anticoagulation Satisfaction Scale

Aim. The aim of this study was to evaluate the internal reliability and validity of the BrazilianPortuguese version of Duke Anticoagulation Satisfaction Scale (DASS) among cardiovascular patients. Background. Oral anticoagulation is widely used to prevent and treat thromboembolic events in several conditions, especially in cardiovascular diseases; however, this therapy can induce dissatisfaction and reduce the quality of life. Design. Methodological and cross-sectional research design. Methods. The cultural adaptation of the DASS included the translation and back-translation, discussions with healthcare professionals and patients to ensure conceptual equivalence, semantic evaluation and instrument pretest. The BrazilianPortuguese version of the DASS was tested among subjects followed in a university hospital anticoagulation outpatient clinic. The psychometric properties were assessed by construct validity (convergent, known groups and dimensionality) and internal consistency/reliability (Cronbachs alpha). Results. A total of 180 subjects under oral anticoagulation formed the baseline validation population. DASS total score and SF-36 domain correlations were moderate for General health (r = -0.47, p < 0.01), Vitality (r = -0.44, p < 0.01) and Mental health (r = -0.42, p < 0.01) (convergent). Age and length on oral anticoagulation therapy (in years) were weakly correlated with total DASS score and most of the subscales, except Limitation (r = -0.375, p < 0.01) (Known groups). The Cronbachs alpha coefficient was 0.79 for the total scale, and it ranged from 0.76 (hassles and burdens)0.46 (psychological impact) among the domains, confirming the internal consistency reliability. Conclusions. The BrazilianPortuguese version of the DASS has shown levels of reliability and validity comparable with the original English version. Relevance to clinical practice. Healthcare practitioners and researchers need internationally validated measurement tools to compare outcomes of interventions in clinical management and research tools in oral anticoagulation therapy.

Cross-cultural adaptation and psychometric properties of the Brazilian version of the scale of oral health outcomes for 5-year-old children (SOHO-5)

Abstract Background Most of the instruments available to measure the oral health-related quality of life (OHRQoL) in paediatric populations focus on older children, whereas parental reports are used for very young children. The scale of oral health outcomes for 5-year-old children (SOHO-5) assesses the OHRQoL of very young children through self-reports and parental proxy reports. We aimed to cross-culturally adapt the SOHO-5 to the Brazilian Portuguese language and to assess its reliability and validity. Findings We tested the quality of the cross-cultural adaptation in 2 pilot studies with 40 children aged 5–6 years and their parents. The measurement was tested for reliability and validity on 193 children that attended the paediatric dental screening program at the University of São Paulo. The children were also clinically examined for dental caries. The internal consistency was demonstrated by a Cronbach's alpha coefficient of 0.90 for the children’s self-reports and 0.77 for the parental proxy reports. The test-retest reliability results, which were based on repeated administrations on 159 children, were excellent; the intraclass correlation coefficient was 0.98 for parental and 0.92 for child reports. In general, the construct validity was satisfactory and demonstrated consistent and strong associations between the SOHO-5 and different subjective global ratings of oral health, perceived dental treatment need and overall well-being in both the parental and children’s versions (p < 0.001). The SOHO-5 was also able to clearly discriminate between children with and without a history of dental caries (mean scores: 5.8 and 1.1, respectively; p < 0.001). Conclusion The present study demonstrated that the SOHO-5 exhibits satisfactory psychometric properties and is applicable to 5- to 6-year-old children in Brazil.

Development and characterization of a distributed measurement system for the evaluation of voltage quality in electric power networks

The research activity carried out during the PhD course in Electrical Engineering belongs to the branch of electric and electronic measurements. The main subject of the present thesis is a distributed measurement system to be installed in Medium Voltage power networks, as well as the method developed to analyze data acquired by the measurement system itself and to monitor power quality. In chapter 2 the increasing interest towards power quality in electrical systems is illustrated, by reporting the international research activity inherent to the problem and the relevant standards and guidelines emitted. The aspect of the quality of voltage provided by utilities and influenced by customers in the various points of a network came out only in recent years, in particular as a consequence of the energy market liberalization. Usually, the concept of quality of the delivered energy has been associated mostly to its continuity. Hence the reliability was the main characteristic to be ensured for power systems. Nowadays, the number and duration of interruptions are the “quality indicators” commonly perceived by most customers; for this reason, a short section is dedicated also to network reliability and its regulation. In this contest it should be noted that although the measurement system developed during the research activity belongs to the field of power quality evaluation systems, the information registered in real time by its remote stations can be used to improve the system reliability too. Given the vast scenario of power quality degrading phenomena that usually can occur in distribution networks, the study has been focused on electromagnetic transients affecting line voltages. The outcome of such a study has been the design and realization of a distributed measurement system which continuously monitor the phase signals in different points of a network, detect the occurrence of transients superposed to the fundamental steady state component and register the time of occurrence of such events. The data set is finally used to locate the source of the transient disturbance propagating along the network lines. Most of the oscillatory transients affecting line voltages are due to faults occurring in any point of the distribution system and have to be seen before protection equipment intervention. An important conclusion is that the method can improve the monitored network reliability, since the knowledge of the location of a fault allows the energy manager to reduce as much as possible both the area of the network to be disconnected for protection purposes and the time spent by technical staff to recover the abnormal condition and/or the damage. The part of the thesis presenting the results of such a study and activity is structured as follows: chapter 3 deals with the propagation of electromagnetic transients in power systems by defining characteristics and causes of the phenomena and briefly reporting the theory and approaches used to study transients propagation. Then the state of the art concerning methods to detect and locate faults in distribution networks is presented. Finally the attention is paid on the particular technique adopted for the same purpose during the thesis, and the methods developed on the basis of such approach. Chapter 4 reports the configuration of the distribution networks on which the fault location method has been applied by means of simulations as well as the results obtained case by case. In this way the performance featured by the location procedure firstly in ideal then in realistic operating conditions are tested. In chapter 5 the measurement system designed to implement the transients detection and fault location method is presented. The hardware belonging to the measurement chain of every acquisition channel in remote stations is described. Then, the global measurement system is characterized by considering the non ideal aspects of each device that can concur to the final combined uncertainty on the estimated position of the fault in the network under test. Finally, such parameter is computed according to the Guide to the Expression of Uncertainty in Measurements, by means of a numeric procedure. In the last chapter a device is described that has been designed and realized during the PhD activity aiming at substituting the commercial capacitive voltage divider belonging to the conditioning block of the measurement chain. Such a study has been carried out aiming at providing an alternative to the used transducer that could feature equivalent performance and lower cost. In this way, the economical impact of the investment associated to the whole measurement system would be significantly reduced, making the method application much more feasible.

Diagnostic techniques for EHD and MHD interaction

The impact of plasma technologies is growing both in the academic and in the industrial fields. Nowadays, a great interest is focused in plasma applications in aeronautics and astronautics domains. Plasma actuators based on the Magneto-Hydro-Dynamic (MHD) and Electro- Hydro-Dynamic (EHD) interactions are potentially able to suitably modify the fluid-dynamics characteristics around a flying body without utilizing moving parts. This could lead to the control of an aircraft with negligible response time, more reliability and improvements of the performance. In order to study the aforementioned interactions, a series of experiments and a wide number of diagnostic techniques have been utilized. The EHD interaction, realized by means of a Dielectric Barrier Discharge (DBD) actuator, and its impact on the boundary layer have been evaluated by means of two different experiments. In the first one a three phase multi-electrode flat panel actuator is used. Different external flow velocities (from 1 to 20m/s) and different values of the supplied voltage and frequency have been considered. Moreover a change of the phase sequence has been done to verify the influence of the electric field existing between successive phases. Measurements of the induced speed had shown the effect of the supply voltage and the frequency, and the phase order in the momentum transfer phenomenon. Gains in velocity, inside the boundary layer, of about 5m/s have been obtained. Spectroscopic measurements allowed to determine the rotational and the vibrational temperature of the plasma which lie in the range of 320 ÷ 440°K and of 3000 ÷ 3900°K respectively. A deviation from thermodynamic equilibrium had been found. The second EHD experiment is realized on a single electrode pair DBD actuator driven by nano-pulses superimposed to a DC or an AC bias. This new supply system separates the plasma formation mechanism from the acceleration action on the fluid, leading to an higher degree of the control of the process. Both the voltage and the frequency of the nano-pulses and the amplitude and the waveform of the bias have been varied during the experiment. Plasma jets and vortex behavior had been observed by means of fast Schlieren imaging. This allowed a deeper understanding of the EHD interaction process. A velocity increase in the boundary layer of about 2m/s had been measured. Thrust measurements have been performed by means of a scales and compared with experimental data reported in the literature. For similar voltage amplitudes thrust larger than those of the literature, had been observed. Surface charge measurements led to realize a modified DBD actuator able to obtain similar performances when compared with that of other experiments. However in this case a DC bias replacing the AC bias had been used. MHD interaction experiments had been carried out in a hypersonic wind tunnel in argon with a flow of Mach 6. Before the MHD experiments a thermal, fluid-dynamic and plasma characterization of the hypersonic argon plasma flow have been done. The electron temperature and the electron number density had been determined by means of emission spectroscopy and microwave absorption measurements. A deviation from thermodynamic equilibrium had been observed. The electron number density showed to be frozen at the stagnation region condition in the expansion through the nozzle. MHD experiments have been performed using two axial symmetric test bodies. Similar magnetic configurations were used. Permanent magnets inserted into the test body allowed to generate inside the plasma azimuthal currents around the conical shape of the body. These Faraday currents are responsible of the MHD body force which acts against the flow. The MHD interaction process has been observed by means of fast imaging, pressure and electrical measurements. Images showed bright rings due to the Faraday currents heating and exciting the plasma particles. Pressure measurements showed increases of the pressure in the regions where the MHD interaction is large. The pressure is 10 to 15% larger than when the MHD interaction process is silent. Finally by means of electrostatic probes mounted flush on the test body lateral surface Hall fields of about 500V/m had been measured. These results have been used for the validation of a numerical MHD code.