Insulation Design of Low Voltage Electrical Motors Fed by PWM Inverters

This paper proposes a model to determine the partial discharge inception voltage of magnet wires, including the effect of elevated temperatures, and shows its applicability to the complete range of wire geometries considered in IEC Standard 60317-13

Evaluation of micromorphological changes in tooth enamel after mechanical and ultrafast laser preparation of surface cavities

The aim of this in vitro study was to evaluate the morphological changes that occur in tooth enamel after mechanical instrumentation and after femtosecond laser irradiation with different parameters via light and scanning electron microscopy (SEM). Twelve totally impacted third molars were collected and sectioned to provide several cut surfaces. These surfaces were exposed to infrared (λ = 795 nm, 120 fs, 1-kHz repetition rate, maximum mean power 1 W) laser pulses and machined by means of a conventional mechanical technique. Two very different geometrical patterns were performed with femtosecond laser pulses: shallow rectangular cavities and deep cylindrical ones. The results of both machining procedures were examined using light and scanning electron microscopy. The SEM images show the femtosecond laser ability to produce high-precision cavities in tooth enamel. No signs of collateral damage, burning, melting, or cracks were observed despite the far different laser pulse energies used (ranging from 7 to 400 μJ), unlike what is seen with conventional mechanical techniques. The femtosecond laser has the potential to become an optimal tool for the treatment of dental decay and as an alternative to the conventional drill to reduce mechanical damage during removal of the hard dental tissue.A.G. and P.M. acknowledge the support of Spanish Ministerio de Ciencia e Innovación through the Consolider Program SAUUL (CSD2007-00013) and research project FIS2009-09522, from Junta de Castilla y León through the Program for Groups of Excellence (GR27) and of the EC Seventh Framework Programme (LASERLAB-EUROPE, grant agreement no. 228334).We also acknowledge the support of the Centro de Laseres Pulsados, CLPU, Salamanca, Spain

Identificación de plantas hospedantes del virus moteado del haba (Vicia faba L.) en el departamento de Nariño.

Presenta los resultados obtenidos al inocular el virus moteado del haba en algunas especies de plantas cultivadas, malezas y algunas indicadoras del virus. El trabajo se llevó a cabo en el Centro de Investigaciones Obonuco (Nariño) en condiciones de invernadero (25 grados centígrados y 80 por ciento de humedad relativa) y en la Universidad de Nariño (14 grados centígrados de temperatura y 60 por ciento de humedad relativa). Se inocularon mecánicamente 21 especies pertenecientes a 6 familias en estado de plántulas, hojas desarrolladas y hojas desprendidas, con diluciones en agua destilada 1:0, 1:10, 1:100 y 1:1000 de savia obtenida de plantas de haba severamente afectadas por el virus del campo. Se pudo establecer que las especies que presentaron síntomas sistémicos mostraron mejor reacción cuando se inocularon en estado de plántula, mientras que síntomas de lesiones locales se manifestaron mejor en hojas desarrolladas. Chenopodium amaranticolor tuvo mejor reacción al virus bajo condiciones de campo, presentando síntomas sistémicos y lesiones locales. Nicotiana rustica presentó lesiones locales y síntomas sistémicos bajo condiciones de invernadero, N. tabacum var. White Burley produjo lesiones locales y Phaseolus vulgaris presentó un mosaico típico diferente al mosaico común y rugoso del fríjol. En las especies que reaccionaron positivamente a la inoculación hubo relación directa entre la concentración del virus inoculado y el número de plantas con síntomas sistémicos y/o número de lesiones localesHaba-Vicia fab

Apoyo a la toma de decisiones para la mejora de la gestión en explotaciones agroforestales

La agricultura actual se encuentra inmersa en un proceso acelerado de actualización y adaptación a un modelo digital de trabajo que se extiende imparable a lo largo de toda la cadena agroalimentaria. Parte de esta evolución viene marcada por la incorporación de las TIC (tecnologías de la información y la comunicación), y por la disponibilidad de nuevas soluciones de hardware y software que están cambiando la forma de trabajar en el campo mediante la monitorización de las labores agrícolas y el análisis de los datos generados en las explotaciones

Modifications on regularity and spectrum of ventricular fibrillation signal induced by physical training

The objective of this work is to study the modifications on cardiac response during ventricular fibrillation (VF) induced by physical training. The analysis was performed in the frequency domain of VF, and the regularity of the signal was also considered. Two sets of records were acquired: control (G1: without physical training, N=10), and trained (G2, N=9). Cardiac registers were obtained using a 240-electrodes matrix located on left ventricle of isolated rabbit heart. A Langendorff system was used to maintain the heart perfusion. VF was induced by increased frequencies. To analyze the time course of VF, records were processed in 4-second segments. For every segment and channel, Welch periodogram with Hanning window, two non-overlapped sections and zero padding, was computed. Parameters considered in frequency domain are: dominant frequency (DF) and normalized energy (NE: spectral energy in the window DF±1Hz, normalized by spectral energy in 5-35Hz band). For every segment and channel, a regularity analysis of VF was performed, obtaining the regularity index (RI), which is a measure of similarity among local activation waves present in every channel. Mean values for the parameters (DF, NE and RI) of the whole set of electrodes were computed for every segment. Obtained results show that DF is lower for trained rabbits (G1: 18.234±1, 241Hz; G2: 14.370±0, 866Hz; p<0.001). NE is greater for this group (G1: 0.140±0.006; G2: 0.263±0.017; p<0.001), suggesting a greater spectral concentration around DF. Finally, a greater regularity has been observed in the fibrillation signal for trained group (IR, G1: 0.756±0.026; G2: 0.834±0.014; p<0.001). As a summary, the results suggest that both spectral characteristics and regularity of VF signal are clearly different for G1 and G2 groups. The trained group (G2) shows greater regularity, lower DF and spectral dispersion. These factors should be interpreted as a more stable cardiac response to V

Analysis of spatial and temporal evolution of regularity maps during ventricular fibrillation

The analysis of cardiac mapping allows investigating the structure of ventricular fibrillation (VF). This work analyzes regions of interest (ROI) on cardiac maps obtained from the regularity analysis of VF records, providing information about signal regularity at each time instant and its spatial distribution. Cardiac registers were obtained using a 240- electrodes matrix located on left ventricle of isolated rabbit heart. A Langendorff system was used to maintain the heart perfusion. VF was induced by increased frequencies. Two groups of records were considered: control (G1: without physical training, N=10), and trained (G2, N=9). Records were processed in consecutive 4-second segments. Regularity index (RI) was obtained for every segment and channel. RI is a measure of similarity degree among local activation waves for every channel. A map with the RI value of each channel was computed for the 82 register segments. To analyze the spatial distribution of RI, a threshold value was determined experimentally and applied to the map in order to obtain the ROI. Two parameters were calculated: ROI spatial number (ROIsn, a measure of spatial fragmentation), and ROI spatial area (ROIsa, the percentage of area map occupied by ROI). In case of the time course of ROI, two additional parameters were computed: the number of electrodes which value had changed respect to the threshold in two consecutive maps (ROIen, which is related with the change size), and the cumulative absolute differences of RI values for the electrodes which are changed (ROIed). Obtained results for spatial analysis show that the number of ROI is lower for trained rabbits (ROIsn; G1: 4.465±1.120; G2: 2.,227±0.623; p<0.001), but ROI spatial area is greater than the control group (ROIsa; G1: 76.235±5.355%; G2: 88.163±2.885%; p<0.001). Time-course analysis shows that more electrodes change between consecutive maps in the control group (ROIen, G1: 22.455±6.702; G2: 13.877±2.485; p<0.001). No significant differences were found for ROIed (G1: 18.509±6.932; G2: 18.619±4.196; n.s.). To conclude, ROI analysis on RI maps applied to trained and no trained rabbits groups shows that VF cardiac response is more irregular and spatially fragmented in no trained group. In addition, regularity maps are more stable with time in trained group

Caracterización genética de las razas Hartón del Valle, Angus, Brangus, Holstein y Senepol en Colombia, usando 10 marcadores microsatélites

ABSTRACT: The objective of this paper is to establish a genetic characterization of the Senepol (S, n=49), Holstein (H, n= 60), Hartón del Valle (HV, n=60), Angus (A, n=61) and Brangus (Br, n=60) cattle breeds in Colombia, by using the following microsatellite markers: SPS115, INRA64, ETH225, ETH10, BM1824, INRA37, TGLA122, TGLA126, INRA32, and BM2113. A total of 142 alleles were obtained for ten analyzed loci, considering the five cattle breeds as a whole. The number of alleles per locus ranged from 9 (INRA64 and 1824) to 22 (TGLA122). The expected heterozygosity was between 0.79 (INRA32) and 0.90 (INRA37) in all the cattle breeds, respectively; and medium heterozygosity was 0.84. The average number of alleles per breed varied from 9.2 in the Senepol breed to 10.3 in the Holstein breed. The expected heterozygosity range varied from 0.75 in the Hartón del Valle breed and 0.82 in the Holstein breed, with an average of 0.79. Hardy Wienberg disequilibrium was observed (p>0.05) when the populations were analyzed with all the markers. All the populations presented a heterozygote deficit, which could be the result of a strong endogamy tendency within all the herds. The markers used in this study allowed a genetic characterization of the analyzed populations. The microsatellites panel in the Hartón del Valle breed should be increased in order to increase the reliability value. Microsatellite panels could solve parenthood cases for the remainder breeds.RESUMEN: El objetivo de este trabajo fue caracterizar genéticamente las razas bovinas Senepol (S, n=49), Holstein (H, n= 60), Hartón del Valle (HV, n=60), Angus (A, n=61) y Brangus (Br, n=60) en Colombia, con los marcadores microsatélites SPS115, INRA64, ETH225, ETH10, BM1824, INRA37, TGLA122, TGLA126, INRA32 y BM2113. En total, 142 alelos fueron encontrados en los diez loci analizados, considerando las cinco razas como un todo. El número de alelos por locus estuvo entre 9 (INRA64 y BM1824) y 22 (TGLA122). La Heterocigosidad esperada a través de todas las razas varió entre 0.79 (INRA32) y 0,90 (INRA37) y heterocigosidad media esperada de 0.84. El número promedio de alelos por raza varió de 9.2 en la raza S a 10.3 en la raza H. El rango de la Heterocigosidad esperada entre las razas varió entre 0.75 en la raza HV y 0.82 en la raza H, con una media de 0.79. Al analizar las poblaciones con el total de marcadores, todas se encontraron en desequilibrio de Hardy Weinberg (p>0.05). Todas las poblaciones presentaron un déficit de heterocigotos, para todas las poblaciones, lo que podría ser el resultado de la fuerte tendencia a la endogamia dentro de los diferentes hatos. Los resultados indicaron que los marcadores utilizados en este estudio permitieron caracterizar genéticamente las poblaciones analizadas. En el caso de la Raza HV, se debe aumentar el panel de microsatélites para aumentar el valor de confiabilidad. Para las demás razas el panel de microsatélites permitiría resolver casos de filiación