The Influence of Swirl Brakes on the Rotordynamic Forces Generated by Discharge-to-Suction Leakage Flows in Centrifugal Pumps

Increasing interest has been give to swirl brakes as a means of reducing destabilizing rotordynamic forces due to leakage flows in new high speed rocket turbopumps. Although swirl brakes have been used successfully in practice (such as with the Space Shuttle HPOTP), no experimental test until now have been performed to demonstrate their beneficial effect over a range of leakage flow rates. The present study investigates the effect of swirl brakes on rotordynamic forces generated by discharge-to-suction leakage flows in the annulus of shrouded centrifugal pumps over a range of subsynchronous whirl ratios and various leakage flow rates. In addition, the effectiveness of swirl brakes in the presence of leakage inlet (pump discharge) swirl is also demonstrated. The experimental data demonstrates that with the addition of swirl brakes a significant reduction in the destabilizing tangential force for lower flow rates is achieved. At higher flow rates, the brakes are detrimental. In the presence of leakage inlet swirl, brakes were effective over all leakage flow rates tested in reducing the range of whirl frequency ratio for which the tangential force is destabilizing

Smoothing River Discharge Time Series Computed Using the Velocity-Area Method

Early warning systems for flood disaster mitigation involves hydrological and hydraulic models. These models require the discharge series as input and calibration. The indirect measurement of discharge, derived using the velocity-area method, presents errors, and thus, uncertainty. The associated uncertainty is mainly caused by the error in estimation since the direct measurement of discharge is neither feasible nor cost-efficient. Smoothing is employed to address the issue. Three smoothing techniques are proposed, i.e. Fourier smoothing, kernel smoothing using the Gaussian Density function, and LOESS Curve Fitting. Two river basins located in Davao del Sur, Lipadas and Padada, were evaluated. The Nash-Sutcliffe Efficiency (NSE) and RMSE-Observations Standard Deviation Ratio (RSR) were used to evaluate smoothing performance. Results showed that the Gaussian kernel smoothing technique outperformed both Fourier method and LOESS for both river discharge series. The values for both NSE and RSR indicated that the technique produced very good performances. The quality of smoothed discharge series was studied using two quality functions, Quality of Discharge (QOD) and BALANCE. Results showed that a more appropriate method would result in a better discharge quality regardless of the smoothing parameter chosen. Therefore, the smoothed discharge series is affected by the choice of smoothing technique and the method of choice is crucial. This study suggests that Gaussian kernel smoothing is a promising technique in smoothing discharge, with bandwidth at around 2 to 10. A very good quality of smoothed discharge is to be expected when the Gaussian kernel technique gives a very good smoothing performance. Keywords: Smoothing · Fourier smoothing · Gaussian Kennel smoothing · LOESS Curve Fitting · NSE · RSR · discharge series · discharge qualit

Pleuropneumonia-like Organisms

This report represents an attempt to review what is presently known about PPLO as concerns their relationship to other life forms and their pathogenicity. A selected portion of the scientific literature on this subject is cited. PPLO are thought to be related to bacteria, probably through their L-forms. Our knowledge of their morphology is still incomplete. PPLO have been found to be the cause of diseases of both animals and men. A great deal of controversy concerning the pathogenicity of PPLO still exists.Natural Scienc

Density Survey of Sago Palms in Sago-identified Areas in Mindanao, Southern Philippines

Sago palm, locally known as lumbia, is one among the many sources of flour. In the Philippines, especially in Mindanao however, it is an untapped resource. Thus, the density of natural sago stands in several areas of Mindanao was determined in this study. Sample locations were identified in several areas of Mindanao and were surveyed using the transect method to determine the population density of sago palms in various growth stages. The number of sago palms in rosette, bole formation, inflorescence, and fruiting stages were determined and categorized according to their age by counting the number of leaf scars and fronds in stand. Transect survey was conducted according to dry, wet, and submerged soil conditions. Further stratification was also done to delineate sago density in areas where local community used sago shingles for roofing and household business. Results showed that sago palms are very dense in Agusan del Sur and Agusan del Norte, and approximately 8,800 trees are in the stage of inflorescence which can be harvested within 1 to 2 years; a total of 209,000 stand in bole formation stage which can be harvested after 4 to 5 years; and about 6.5 million rosette in varying ages. These results indicate that the sago palm can be a potential economic enterprise for farmers within Mindanao

Calidad de servicio en la lealtad de marca de la empresa FERSALUD, Lima 2022

La presente investigación tuvo como objetivo determinar la relación entre calidad de servicio y lealtad de marca de la empresa Fersalud, Lima, 2022. Siendo así, la metodología utilizada de tipo aplicada con diseño no experimental, descriptivo correlacional y transversal. La población fue de 300 pacientes de la empresa, y la muestra de 196 pacientes, el instrumento utilizado fue el cuestionario, la cual cumplió los requisitos de validez gracias al juicio de expertos y confiabilidad cuyo resultado fue bueno. Se utilizó el Rho de Spearman para la prueba de hipótesis, siendo el resultado obtenido que la calidad de servicio se relaciona con la lealtad de marca, con un nivel de correlación positiva moderada (Rho 0,470 y p-valor 0,000)

Assessment of Potential Sago Starch Content in Sago Palm Forests in Mindanao, Southern Philippines

This paper presents the results of the assessment of the potential yield of sago palms in Mindanao, Southern Philippines. Previous studies have characterized the growth parameters of sago palms as influenced by their environmental growth conditions and anthropogenic activities of the local residents in the area, thereby affecting the potential yield of starch. In this study, a total of 60 sago palms were harvested and cut into logs and brought to central facility where each log was manually debarked, stripped, solar dried, milled, and sieved. Samples were obtained from identified 3 environmental growth environments (dry, wet, and submerged soil conditions) and from undisturbed and disturbed areas where the local community utilized the leaves for roofing. The results showed that on average, starch yield was maximum in palms grown in wet environment and without anthropogenic disturbance. Furthermore, the results were consistent with previous works that starch is at the maximum at inflorescent stage (247.5 kg/palm), and in bole formation stage (127.1 kg/palm), and lowest at fruiting stage (63.1 kg/palm). With these results and utilizing the sago density data from a previous study, we conclude that 2,000 tons of starch can be harvested within 1 to 2 years and about 20,000 tons in another 4 to 5 years. Further study is recommended to include cost of production in the sustainability assessment

Identification of research priorities in CHD:Empowering patients and families through participation in the development of formal research agendas

Background: Conquering CHD, formerly known as the Pediatric Congenital Heart Association (PCHA), is the leading congenital heart disease (CHD) patient advocacy organisation in the United States of America, and places high priority on patient engagement in the research process. Participatory design is an approach to problem-solving that utilises the knowledge and opinions of groups of people to generate plans and new ideas. Utilising this mode of patient engagement, patients and families engaged with Conquering CHD assisted in developing a list of research priorities which was then distributed to the larger membership with instructions to rank the priorities in order of importance. Upon completion, these items were compared to the current scientific literature to assess correlation with current publications. This cross-sectional study and literature review aimed to assess the priorities of patients and families in CHD research and to determine the reflection of these areas in the current body of scientific literature. Methods: This cross-sectional study utilised a survey asking participants to rank the importance of research items within categories including Technology Advances, Genetic and Cellular Research, Broad Understanding of CHD, and Psychosocial Outcomes which was distributed through social media and email to 43,168 accounts across all platforms. Respondents were asked to place each item in a ranked order in each category, with the value 1 representing the most preferred for each participant. Anyone engaged with Conquering CHD was eligible to complete the study, including patients and families. Subsequently, a literature review of the largest medical databases including PubMed, Scopus, and ScienceDirect was undertaken to determine the number of articles published per each topic which was then assessed to determine if there is a correlation between patient-ranked priorities and the current body of literature. Results: The study generated a total response of 527 participants. Regarding Technology Advances, valve replacement was the preferred topic (mean rank 2.07, IQR 2). Stem cell research was the favoured topic in Genetic and Cellular Research (mean rank 2.53, IQR 2). Access to care was the priority in the Broadening Understanding of CHD (mean rank 1.24, IQR 1). Pertaining to Psychosocial Outcomes, psychological/emotional effects was the highest ranked topic (mean rank 1.46, IQR 1). The literature review returned a total of 135,672 articles in the areas of interest. For Valve Replacement, 8361 articles resulted reflecting a proportion of 0.097 of total articles. For Stem Cell Research, 9921 articles resulted reflecting a proportion of 0.115 of total articles. For Access to Care, 7845 articles resulted reflecting a proportion of 0.091 of total articles. For Psychological/Emotional Effects, 6422 articles resulted reflecting a proportion of 0.074 of total articles. A Spearman's correlation demonstrated no correlation between the preferred domain of CHD research and the number of articles published for that domain (rs = 0.02, p = 0.94). Conclusions: This process demonstrates the effectiveness of participatory design, using a patient and family network to determine the research items of concern to those affected by CHD. The cross-sectional survey was effective in assessing patient and family priorities but was limited by access to reliable internet and delivery only in English. Though the study had a large response rate, it was limited to patients already engaged with Conquering CHD. For these reasons, it may not completely reflect the opinions of the total population affected by CHD. However, this offers valuable insight into patient-determined priorities and reveals that the current scientific literature does not correlate with these items. These data serve to inform individual and institutional research agendas to better reflect the needs and desires of this population.</p

Actividades físicas para mejorar la calidad de vida en estudiantes de bachillerato

Introduction: The relationship between physical activity and quality of life emerges as a crucial issue in the field of health and well-being. Beyond maintaining good physical health, regular physical activity significantly influences emotional, social and psychological aspects of daily life. Goals: The objective is to improve the quality of life of high school students through a physical activity program. Methodology: For the research, a longitudinal quantitative approach was adopted, combining theoretical and empirical methods. The Satisfaction with Life Scale (SWLS) was used before and after the program, along with physical fitness tests. Results: The results revealed a significant correlation between pre- and post-program physical fitness measurements, evidencing consistent improvements in physical fitness related to program participation. Before the program, the means of all dimensions evaluated were in a moderate range, but after the program a substantial increase was observed in all areas, indicating a significant improvement in satisfaction with life in general. Specifically, increases in physical and emotional well-being, self-esteem, social interactions, and sense of achievement and purpose were highlighted. Conclusions: These results highlight the need to integrate physical activity into the educational environment to promote active and healthy lifestyles from an early age, which can generate benefits in the general well-being of individuals. General Study Area: Sports Training. Specific study area: Physical Activity. Study type: original.Introducción: La relación entre la actividad física y la calidad de vida emerge como un tema crucial en el ámbito de la salud y el bienestar. Más allá de mantener una buena salud física, la actividad física regular influye de manera significativa en aspectos emocionales, sociales y psicológicos de la vida cotidiana. Objetivos: El objetivo es mejorar la calidad de vida de los estudiantes de bachillerato a través de un programa de actividades físicas. Metodología: Para la investigación, se adoptó un enfoque cuantitativo longitudinal, combinando métodos teóricos y empíricos. Se utilizó la Escala de Satisfacción con la Vida (SWLS) antes y después del programa, junto con pruebas de condición física. Resultados: Los resultados revelaron una correlación significativa entre las mediciones de condición física previas y posteriores al programa, evidenciando mejoras coherentes en la condición física relacionadas con la participación en el mismo. Antes del programa, las medias de todas las dimensiones evaluadas se situaban en un rango moderado, pero tras el programa se observó un aumento sustancial en todas las áreas, indicando una mejora significativa en la satisfacción con la vida en general. Concretamente, se destacaron incrementos en el bienestar físico, emocional, autoestima, interacciones sociales y sentido de logro y propósito. Conclusiones: Estos resultados subrayan la necesidad de integrar la actividad física en el ámbito educativo para fomentar estilos de vida activos y saludables desde temprana edad, lo que puede generar beneficios en el bienestar general de los individuos. Área de estudio general: Entrenamiento deportivo. Área de estudio específica: Actividad Física. Tipo de estudio: original