Universidad Nacional de Trujillo: Publicaciones Científicas
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Energy efficiency of heating machines and its effects on broiler's performance and welfare
Get PDFThe increasing global demand for animal protein has driven the broiler industry to optimize production systems and better understand limiting factors affecting performance. This study evaluated four different heating systems to determine their correlation with climatic variables, zootechnical performance, pellet fuel consumption, and energy usage. Data were obtained from a private broiler integration company in Southwest Paraná, Brazil, specializing in the griller broiler category. The study covered a 28-day housing period for 12 flocks (both male and female), each consisting of approximately 120,000 birds, for 28 days. The analyzed variables included indoor and outdoor environmental temperature, relative air humidity, carbon dioxide (CO₂) concentration inside the poultry houses, feed conversion ratio, weight gain, pellet fuel consumption, and energy consumption. Statistical analyses were performed using descriptive statistics and Principal Component Analysis (PCA) in R software. Results indicated that correlations among variables were generally weak. However, environmental conditions had the greatest influence on broiler performance. The first principal component explained 74.1% of the total variance, with minimum CO₂ concentration, external temperature, minimum and maximum internal temperature, and pellet fuel consumption being key contributing factors. The second principal component included maximum CO₂ concentration, weight gain, and minimum internal and external relative humidity. Among the evaluated heating systems, the fourth machine tested exhibited the lowest pellet fuel consumption while maintaining satisfactory weight gain and feed conversion rate despite its relatively high energy consumption. These findings suggest that temperature control and pellet fuel consumption are critical factors in optimizing broiler production efficiency, ultimately contributing to improved growth performance and resource utilization
Comparative analysis of extraction methods for bioactive compounds in aromatic and medicinal plants
No full textThe main extraction techniques for bioactive compounds from aromatic and medicinal plants include maceration, distillation, supercritical CO2, and ultrasound. These methods can be differentiated based on their efficiency, sustainability, and their ability to extract and preserve compounds such as essential oils, which primarily contain flavonoids and terpenes. Traditional methods, such as maceration and distillation, are useful for extracting heat-sensitive and volatile compounds but have limitations in terms of time and energy consumption. In contrast, modern techniques, such as supercritical CO2 and ultrasound, are more efficient and environmentally friendly, enhancing compound preservation and significantly reducing environmental impact; however, they are more costly than the other methods. Nevertheless, recent research has shown a significant increase in studies on supercritical CO2 and ultrasound, along with their growing adoption in industries such as cosmetics, food, pharmaceuticals, and biotechnology
Kinetic evaluation of the Arrhenius equation for artificial ageing of polymers
No full textArtificial ageing of polymers is a crucial and complex issue, especially considering that critical infrastructures such as nuclear power plants have lifespans varying from 40 to 60 years or even longer. Controlled artificial ageing allows the evaluation of polymer lifetimes while ensuring that their properties are preserved. However, a unified and validated methodology for artificially ageing polymers is still lacking.
One of the most extended methodologies for the artificial ageing of polymers is the Arrhenius methodology. This methodology is based on the application of the Arrhenius equation, which is extensively applied in the study of thermal decomposition reactions. Nevertheless, the Arrhenius methodology requires the estimation of activation energy, and the lack of a unified method introduces variability in results obtained using different methods. Furthermore, the Arrhenius ageing methodology assumes that the kinetic parameters do not change during ageing, meaning that aged and non-aged materials should exhibit the same activation energy.
The present work aims to analyse the hypothesis of unvariable activation energy during ageing. This was investigated using both new and artificially aged PVC samples, evaluating the activation energy through various mathematical models based on thermogravimetric analysis.Artificial ageing of polymers is a crucial and complex issue, especially considering that critical infrastructures such as nuclear power plants have lifespans varying from 40 to 60 years or even longer. Controlled artificial ageing allows the evaluation of polymer lifetimes while ensuring that their properties are preserved. However, a unified and validated methodology for artificially ageing polymers is still lacking.
One of the most extended methodologies for the artificial ageing of polymers is the Arrhenius methodology. This methodology is based on the application of the Arrhenius equation, which is extensively applied in the study of thermal decomposition reactions. Nevertheless, the Arrhenius methodology requires the estimation of activation energy, and the lack of a unified method introduces variability in results obtained using different methods. Furthermore, the Arrhenius ageing methodology assumes that the kinetic parameters do not change during ageing, meaning that aged and non-aged materials should exhibit the same activation energy.
The present work aims to analyse the hypothesis of unvariable activation energy during ageing. This was investigated using both new and artificially aged PVC samples, evaluating the activation energy through various mathematical models based on thermogravimetric analysis
Mathematical Modeling and Numerical Simulation for the Design of Agricultural Irrigation Channels with Bend Failures
No full textThis work analyzes water flows in open irrigation channels with bend failures. To improve this failure, a mathematical model based on elliptic equations is proposed, which is solved by applying the SchwarzChristoffel transformation in complex analysis. Given its complex geometry, and with the desire to improve the structural curve of the channel, a numerical method is employed for adaptive mesh generation, based on conformal mapping via the Schwarz-Christoffel transformation. This allows for the obtaining of orthogonal meshes adapted to the geometry of the bends. The fundamental part of this study lies in the detailed simulation of the flow in the channel bends and in the evaluation of the bend’s geometric configuration and the improvement technique for hydraulic efficiency of the channel, ultimately aiming to enhance its hydraulic performance. The results obtained will be contrasted with the data found in Google Earth satellite imagery and numerical analysis, using devices such as drones to discuss the results and draw useful conclusions for the design of irrigation channels with bend failures. En este trabajo se analizan flujos de agua en canales de riego abiertos con fallas de recodos. Con el propósito de mejorar esta falla se propone un modelo matemático basado en las ecuaciones elípticas, la cual se resuelve aplicando la transformada de Schwarz - Christoffel en el análisis complejo. Dada su complejidad geométrica, con el deseo de mejorar la curva estructural del canal se emplea un método numérico para la generación de adaptabilidad de mallas, basadas en el mapeo conforme mediante la transformación de Schwarz - Christoffel, lo que permite obtener mallas ortogonales adaptadas a la geometría de los recodos. La parte fundamental de este estudio radica en la simulación detallada del flujo en los recodos del canal y en la evaluación de la configuración geométrica del recodo y de la técnica de mejoramiento de esta falla para eficiencia hidráulica del canal que permitan mejorar su eficiencia hidráulica. Los resultados obtenidos se contrastaran mediante la obtencion de datos encontrados en el mapa satelital Google Earth y el análisis numérico, dispositivos como el drone que permitirán discutir los resultados y dar conclusiones útiles en el diseño de canales de riego con falla de recodos
Insuficiencia cardíaca secundaria a levantinib. Un evento atípico: Reporte de caso
No full textEn este reporte, presentamos el caso de una paciente de 73 años con carcinoma papilar infiltrante de tiroides tratada con lenvatinib, quien desarrolló insuficiencia cardíaca secundaria al fármaco. Inicialmente, presentó disnea progresiva sin antecedentes cardiovasculares previos. La evaluación ecocardiográfica mostró una fracción de eyección reducida al 40%, lo que, junto con la temporalidad de los síntomas, llevó a sospechar cardiotoxicidad inducida por lenvatinib. Se aplicó el algoritmo de Naranjo, estableciendo una relación probable. Se suspendió el fármaco e inició manejo con diuréticos, betabloqueadores e inhibidores del sistema renina-angiotensina, logrando mejoría clínica con recuperación parcial de la fracción de eyección al 50% y normalización del proBNP. Este caso subraya la necesidad de vigilancia cardiovascular en pacientes bajo terapia con inhibidores de tirosina quinasa, destacando la importancia de una detección temprana y el ajuste oportuno del tratamiento para prevenir complicaciones graves
Estudio Numérico del Desempeño Térmico de Tubos de Vacío para Termas Solares Adaptadas al Escenario Costero Peruano
No full textThe present research aimed to theoretically determine the arrangements of evacuated tubes, considering both tilt angle and inter-tube spacing, that maximize the total annual energy collection for five Peruvian coastal cities. The parameters considered included tube dimensions, azimuthal orientation, tilt angle, and inter-tube spacing. To perform a parametric study of the total solar energy captured by a single evacuated tube, varying the tilt angle for each of the 365 days of the year, the spacing between tubes, and the geographic location of five coastal Peruvian cities, a mathematical model was implemented in Matlab/Octave. The results show that maximum solar energy collection is achieved with tilt angles between 0° and 15° and a relative spacing between tubes equal to twice the outer diameter. Furthermore, it was demonstrated that the optimal operating tilt angles of evacuated tubes depend on the specific city in which they are installed. Unlike commercial systems, tubes arranged at a 15° tilt can capture greater amounts of energy without compromising their thermal conversion through the thermosiphon effect.El presente trabajo de investigación tuvo como objetivo determinar teóricamente los arreglos de los tubos de vacío, considerando el ángulo de inclinación y la separación entre tubos, que colectan la mayor cantidad de energía total anual para cinco ciudades costeras peruanas. Se consideraron como parámetros las dimensiones de los tubos, la orientación acimutal, el ángulo de inclinación y el espaciamiento entre tubos. Para realizar un estudio paramétrico de la energía solar total captada por un tubo de vacío, variando el ángulo de inclinación para cada uno de los 365 días del año, la separación entre tubos y la ubicación geográfica de cinco ciudades costeras del Perú se implementó un modelo matemático en Matlab/Octave. Los resultados muestran que la captación máxima de energía solar se logra con inclinaciones entre 0° y 15° y una separación relativa entre tubos de dos veces el diámetro exterior, así mismo quedo evidenciando que los ángulos óptimos de trabajo de los tubos al vacío dependen de la ciudad en los cuales se van a usar. A diferencia de los sistemas comerciales, los tubos dispuestos a 15° pueden captar mayor energía sin comprometer su conversión térmica mediante el efecto termosifón
Validación de la escala violencia familiar en adolescentes peruanos
No full textEl presente artículo tuvo como objetivo principal determinar las propiedades psicométricas de la escala violencia familiar en adolescentes peruanos. El tipo de estudio fue psicométrico donde se verificó los índices de validez de la escala en un contexto educativo de la selva peruana. Se contó con la participación de 179 adolescentes usando un tipo de muestreo no probabilístico a conveniencia de autor. La edad de los participantes osciló entre los 11 y 17 años, siendo un 53,1 % de sexo femenino y un 46,9 % del sexo masculino. Los resultados, evidencian buenos índices de bondad de ajuste, siendo un modelo propuesto por 14 ítems con Chi Cuadrado = 130,5 y los grados de libertad = 76, siendo el valor de χ²/df =1,717 dicho valor indica un buen ajuste y un modelo aceptable, además, el CFI = 0,928, TLI = 0,914, RMSEA = 0,063, GFI = 0,905 y el SRMR = 0,042. En conclusión, la escala de violencia familiar resultó ser adecuada con óptimas propiedades psicométricas e índices de bondad de ajuste y apto para ser aplicada en futuras investigaciones
Synthesis, characterization and biological activity of the Cu (II)-1,3-PDTA [(Cu (II) (PDTA)] complex for the control of Erwinia chrysanthemi (soft rot) in the parsley manioc (Arracacia xanthorrhiza Bancroft)
Get PDFSynthesis, characterization and biological activity of the Cu(II)-1,3-PDTA complex was performed by two synthetic routes: sodium and carbonate pathways. The Cu (II)-1,3-PDTA complex can be easily produced by the 1,3-PDTA binder, commercially available as Trilon F (BASF) which is available as sodium or acid salt for the coordination of Cu (II). The biological activity of the Cu (II)-1,3-PDTA [Cu (II)-PDTA] complex was performed to analyze the activity against the bacterium Erwinia chrysanthemi Bancroft. The bacterium is the causative agent of soft rot in the parsley maniac (Arracacia xanthorrhiza Bancroft). The bacterium was isolated from parsley manioc infected with soft rot. The metal complex sensitivity tests were performed by diffusion antibiogram. The mean values of the halos and standard deviations of the zones of inhibition were obtained for the [Cu (II) (PDTA)] and Streptomycin complexes. The concentrations of the complexes evaluated were 10-3, 10-2 and 10-1 M (equivalent to 36.3 g L-1 (3.63%), 3.63 g L-1 (0.363%) and 0.363 g L-1 (0.0363%), respectively). The halos were 25.0 ± 1.2 mm for control. For [Cu (II) (PDTA)] complexes, the obtained values were 9.5 ± 0.6, 15.0 ± 0.8 and 24.0 ± 0.8 via sodium and 12.0 ± 1.6, 25.0 ± 0.8 and 31.0 ± 1.9 via carbonate, for 10-3, 10-2 and 10-1 M, respectively. The results showed that the bactericidal activity of the Cu (II)-1,3-PDTA complex obtained by the two synthetic routes are adequate for the control of Erwinia chrysanthemi Bancroft
Factores de riesgo maternos de mortalidad perinatal en el Hospital Belén de Trujillo 2012 – 2021
Get PDFLa mortalidad perinatal, definida como la muerte que ocurre desde la semana 22 de gestación hasta los 28 días después del nacimiento, tiene una prevalencia estimada de 1 por cada 200 embarazos. El objetivo del estudio fue determinar los factores de riesgo maternos asociados a la mortalidad perinatal en el Hospital Belén de Trujillo durante el periodo 2012-2021. El estudio fue observacional analítico de casos y controles, con una población de 764 casos de muerte perinatal (casos) y 2,292 gestantes sin muerte perinatal (controles). Mediante regresión logística múltiple, se identificaron factores maternos de riesgo asociados a la mortalidad perinatal, tales como: edad materna extrema (OR = 1.244), procedencia fuera de Trujillo (OR = 1.672), nivel de instrucción hasta primaria (OR = 1.4), más de dos gestas (OR = 1.506), menos de 6 controles perinatales (OR = 7.102), rotura prematura de membranas (OR = 1.662) y parto pretérmino (OR = 7.765), todos con significancia estadística. El modelo mostró una capacidad predictiva adecuada, con un área bajo la curva ROC de 0.835 y un nivel de clasificación correcto de 85.3%, lo que indica que los factores mencionados tienen una buena capacidad predictiva para la mortalidad perinatal
Acción por el Clima: Análisis Bibliométrico de los 100 artículos más citados publicados en SCOPUS
Get PDFEl presente análisis bibliométrico de los artículos sobre el Objetivo de Desarrollo Sostenible 13 “Acción por el Clima”, publicados en SCOPUS en el periodo 2015-2022, tiene como propósito dar a conocer la evolución de la producción científica sobre “Acción por el clima” por países y en el tiempo en Scopus; elaborar rankings de los 10 principales autores, filiaciones, revistas y editoriales donde se publican, y sponsors que financian las investigaciones; y redes de coautorías y de coocurrencias basadas en un ranking 100 de los artículos más citados empleando VOSviewer. Comprendió 1960 artículos con los criterios de búsqueda. La investigación, basada en las producciones científicas, concluye que las investigaciones al respecto siguen en crecimiento, pero que hay que promover mayor inversión en programas sostenibles para mitigar el impacto del calentamiento global, atendiendo las recomendaciones de especialistas en el tema, de manera que los lideres mundiales tomen acuerdos para favorecer al planeta