Design of Experiments Approach for Statistical Classification of Stereolithography Manufacturing Build Parameters: Effects of Build Orientation on Mechanical Properties for ASTM D-638 Type I Tensile Test Specimens of DSM Somos® 11120 Resin

A statistical design of experiments (DOE) approach was used to determine if specific build orientation parameters impacted mechanical strength of fabricated parts. A single platform (10- inch by 10 inch cross-section) on the 3D Systems Viper si2 machine was designed to hold 18, ASTM D-638 Type I samples built in six different orientations (called Location) with three samples built for each location. The DOE tested four factors: Location, Position, Axis, and Layout. Each sample within a Location was labeled as Positions 1, 2, or 3 depending on the distance from the center of the platform with Position 1 being the closest to the center. Samples were fabricated parallel with the x-axis, y-axis, or 45o to both axes (called Axis 1, 2, and 3, respectively) and were fabricated either flat or on an edge relative to the x-y plane (called Layout 1 and 2, respectively). The results from the statistical analyses showed that Axis, Location, and Position had no significant effect on UTS or E. However, Layout (or whether a sample was built flat or on an edge) was shown to have a statistically significant effect on UTS and E (at a 95% level of confidence). This result was not expected since a comparison of the average UTS for each Layout showed only a 1.2% difference (6966 psi versus 7050 psi for samples built flat and on an edge, respectively). Because of the small differences in means for UTS, the statistical differences between Layout most likely would not have been identified without performing the DOE. Furthermore, Layout was the only factor that tested different orientations of build layers (or layer-to-layer interfaces) with respect to the sample part, and thus, it appears that the orientation of the build layer with respect to the fabricated part has a significant effect on the resulting mechanical properties. This study represents one of many to follow that is using statistical analyses to identify and classify important fabrication parameters on mechanical properties for layer manufactured parts. Although stereolithography is the focus of this work, the techniques developed here can be applied to any layered manufacturing technology.Mechanical Engineerin

Paper Session II-C - A NASA Predictive Safety Model

A proactive methodology for accident prevention, called Continuous Hazard Tracking and Failure Prediction Methodology (CHTFPM), has been developed by utilizing the principles of work sampling and control charting. Sampling is performed to observe the occurrence of conditions that may become hazardous in a given system. These conditions, known as dendritics, could eventually result in an accident or occupational disease. The CHTFPM involves a random sampling for the occurrence of these dendritics. The collected data is then used to generate a control chart. Based on the pattern of the control chart, a system “under control” is not disturbed whereas a system “out of control” is investigated for potential conditions becoming hazardous. Appropriate steps can then be taken to eliminate or control these potentially dangerous and costly conditions to maintain a safe system

Structure and dynamics of the Shapley Supercluster

We present results of our wide-field redshift survey of galaxies in a 285 square degree region of the Shapley Supercluster (SSC), based on a set of 10529 velocity measurements (including 1201 new ones) on 8632 galaxies obtained from various telescopes and from the literature. Our data reveal that the main plane of the SSC (v~ 14500 km/s) extends further than previous estimates, filling the whole extent of our survey region of 12~degrees by 30~degrees on the sky (30 x 75~h-1 Mpc). There is also a connecting structure associated with the slightly nearer Abell~3571 cluster complex (v~ 12000km/s. These galaxies seem to link two previously identified sheets of galaxies and establish a connection with a third one at V= 15000 km/s near R.A.= 13h. They also tend to fill the gap of galaxies between the foreground Hydra-Centaurus region and the more distant SSC. In the velocity range of the Shapley Supercluster (9000 km/s < cz < 18000 km/s), we found redshift-space overdensities with b\_j < 17.5 of ~5.4 over the 225 square degree central region and ~3.8 in a 192 square degree region excluding rich clusters. Over the large region of our survey, we find that the intercluster galaxies make up 48 per cent of the observed galaxies in the SSC region and, accounting for the different completeness, may contribute nearly twice as much mass as the cluster galaxies. In this paper, we discuss the completeness of the velocity catalogue, the morphology of the supercluster, the global overdensity, and some properties of the individual galaxy clusters in the Supercluster.Comment: Accepted for publication in Astronomy and Astrophysic

Análisis de las dimensiones de cinismo organizacional de los trabajadores sindicalizados del sector manufacturero de Cartagena de Indias /

El propósito de la presente investigación consistió en el análisis de los factores de Cinismo Organizacional (CO) que emergen en los trabajadores vinculados a organizaciones sindicales en el sector manufacturero de la ciudad de Cartagena de Indias, Colombia; durante el periodo 2017- 2018.Incluye referencias bibliográficas (página 49-56) y anexo

Redshift-space limits of bound structures

An exponentially expanding Universe, possibly governed by a cosmological constant, forces gravitationally bound structures to become more and more isolated, eventually becoming causally disconnected from each other and forming so-called "island universes". This new scenario reformulates the question about which will be the largest structures that will remain gravitationally bound, together with requiring a systematic tool that can be used to recognize the limits and mass of these structures from observational data, namely redshift surveys of galaxies. Here we present a method, based on the spherical collapse model and N-body simulations, by which we can estimate the limits of bound structures as observed in redshift space. The method is based on a theoretical criterion presented in a previous paper that determines the mean density contrast that a spherical shell must have in order to be marginally bound to the massive structure within it. Understanding the kinematics of the system, we translated the real-space limiting conditions of this "critical" shell to redshift space, producing a projected velocity envelope that only depends on the density profile of the structure. From it we created a redshift-space version of the density contrast that we called "density estimator", which can be calibrated from N-body simulations for a reasonable projected velocity envelope template, and used to estimate the limits and mass of a structure only from its redshift-space coordinates.Comment: Contains 12 pages, 12 figures and 8 table

Effects of Cinnamomum zeylanicum on glycemic levels in patients with type 2 diabetes: Randomized clinical trial

Objetivo: Evaluar el efecto del consumo de suplemento de Cinnamomum zeylanicum (canela) en los niveles glucémicos de adultos mexicanos con diabetes tipo 2. Métodos: Se realizó un ensayo clínico aleatorizado simple ciego con 30 pacientes >18 años con diabetes tipo 2, se aleatorizaron en los grupos: intervención y control; donde consumieron cápsulas con 2 gramos de C. zeylanicum o harina de trigo (placebo) diario por 12 semanas y se midieron variables antropométricas y bioquímicas (HbA1c, GPa, triglicéridos, colesterol total, HDL y LDL). Se utilizó el software IBM SPSS versión 23 y se aplicó la prueba T-Student y U-Mann Withney para muestras independientes (según el comportamiento de la variable) para las diferencias entre grupos, valores p0.05). Sin embargo, post-tratamiento el grupo intervención disminuyó significativamente HbA1c al compararlo con su línea base (-0.41%, p=0.01) mientras que no se encontraron diferencias en el grupo control (+0.03%, p=0.64). No hubo diferencias significativas en variables antropométricas ni bioquímicas. Conclusiones: El consumo de 2 g de C. zeylanicum en mexicanos con diabetes tipo 2 no produjo cambios significativos entre grupos. Se sugieren nuevos estudios donde se evalúe el suplemento de canela con una muestra mayor. ClinicalTrials.gov; NCT04023539Objective: To evaluate the effect of Cinnamomum zeylanicum (cinnamon) supplement use on the glycemic levels of Mexican adults with type 2 diabetes. Methods: A single-blind randomized clinical trial was conducted with 30 patients over 18 years of age with type 2 diabetes. They were randomized into intervention and control groups where they took 2-gram capsules of Cinnamomum zeylanicum or wheat flour (placebo) daily for 12 weeks; then the anthropometric and biochemical variables HbA1c, FPG, triglycerides, total cholesterol, HDL and LDL were measured. IBM SPSS version 23 software was used and the Student's t-test and Mann-Whitney U test for independent samples (according to the behavior of the variable) were applied for differences between groups, p-values 0.05). However, post-treatment, the HbA1c value in the intervention group decreased significantly when compared to their baseline (-0.41%, p=0.01), while no differences were found in the control group (+0.03%, p=0.64). There were no significant differences in the anthropometric or biochemical variables. Conclusions: The consumption of 2 g of Cinnamomum zeylanicum in Mexican people with type 2 diabetes did not produce significant changes between the groups. New studies evaluating cinnamon supplementation on a larger sample size are suggested. ClinicalTrials.gov; NCT0402353

Description of Genetic Variants in BRCA Genes in Mexican Patients with Ovarian Cancer: A First Step towards Implementing Personalized Medicine

Abstract Gynecologic cancers are among the leading causes of death worldwide, ovarian cancer being the one with the highest mortality rate. Olaparib is a targeted therapy used in patients presenting mutations in BRCA1 and BRCA2 genes. The aim of this study was to describe BRCA1 and BRCA2 gene variants in Mexican patients with ovarian cancer. Sequencing of BRCA1 and BRCA2 genes from tumors of 50 Mexican patients with ovarian cancer was made in a retrospective, non-randomized, and exploratory study. We found genetic variants in 48 of 50 cases. A total of 76 polymorphic variants were found in BRCA1, of which 50 (66%) had not been previously reported. Furthermore, 104 polymorphic variants were found in BRCA2, of which 63 (60%) had not been reported previously. Of these polymorphisms, 5/76 (6.6%) and 4/104 (3.8%) were classified as pathogenic in BRCA1 and BRCA2, respectively. We have described the genetic variants in BRCA1 and BRCA2 of tumors from Northeast Mexican patients with sporadic ovarian cancers. Our results showed that the use of genetic testing helps recognize patients that carry pathogenic variants which could be beneficial for personalized medicine treatments. Keywords: BRCA; ovarian cancer; personalized therapy; sequencin

The Limits of Bound Structures in the Accelerating Universe

According to the latest evidence, the Universe is entering an era of exponential expansion, where gravitationally bound structures will get disconnected from each other, forming isolated `island universes'. In this scenario, we present a theoretical criterion to determine the boundaries of gravitationally bound structures and a physically motivated definition of superclusters as the largest bound structures in the Universe. We use the spherical collapse model self-consistently to obtain an analytical condition for the mean density enclosed by the last bound shell of the structure (2.36 times the critical density in the present Universe, assumed to be flat, with 30 per cent matter and 70 per cent cosmological constant, in agreement with the previous, numerical result of Chiueh and He). $N$-body simulations extended to the future show that this criterion, applied at the present cosmological epoch, defines a sphere that encloses $\approx 99.7$ per cent of the particles that will remain bound to the structure at least until the scale parameter of the Universe is 100 times its present value. On the other hand, $(28\pm 13)$ per cent of the enclosed particles are in fact not bound, so the enclosed mass overestimates the bound mass, in contrast with the previous, less rigorous criterion of, e.~g., Busha and collaborators, which gave a more precise mass estimate. We also verify that the spherical collapse model estimate for the radial infall velocity of a shell enclosing a given mean density gives an accurate prediction for the velocity profile of infalling particles, down to very near the centre of the virialized core.Comment: 10 pages, 11 figure

Sociodemographic and health predictors of concern about COVID-19 infection in Cuban patients with type 2 diabetes mellitus

Introduction: Concern about becoming infected is a particularly relevant psychological aspect in the context of a pandemic, as it is associated with social reactions and behavioral changes. Objectives: The present study sought to determine some sociodemographic and health factors associated with concern about COVID-19 infection in Cuban patients with type 2 diabetes mellitus. Methods: 203 patients with type 2 diabetes mellitus, who attended nine primary care areas of four Cuban provinces belonging to different regions of the country (65.52% female, mean age 57.5, SD=19.2), selected through non-probabilistic sampling, participated in the study. A sociodemographic questionnaire, the COVID-19 contagion concern scale (PRE-COVID-19) and an evaluation of blood glucose level were applied. Bivariate associations were examined with a series of analyses of variance (ANOVA). Adjusted (multiple) regression with all predictors running simultaneously was also used. Results: Bivariate analyses showed that age, sex, education, occupation, having comorbidities, and having a family member or friend who had COVID-19 were significantly related to COVID-19 contagion concern. However, when all variables were included simultaneously, only age, technical education, having comorbidities, and having a friend or family member who had COVID-19 remained significant predictors of concern about COVID-19 infection. Conclusions: Male patients, with a technical level of education, with comorbidities and those who had infected family members or friends presented greater concern for the contagion of COVID-19. The public health policies should develop strategies to assess the mental health of people belonging to vulnerable groups and provide interventions to promote mental health in those who show concern about infection

Influencia de los sistemas de producción y pisos altitudinales en la composición bioquímica y rendimiento del pasto nicarión (setaria sphacelata)

La investigación tuvo como objetivo evaluar el efecto de sistemas de producción y pisos altitudinales en la composición bioquímica y rendimiento del pasto nicarión (Setaria sphacelata) en el distrito de Molinopampa, en dos pisos altitudinales entre los 2000-2400 m s.n.m. y 2401-2800 m s.n.m. En cuanto a los sistemas de producción se consideró el sistema silvopastoril y el sistema de pastoreo a campo abierto. En cada piso altitudinal se identificaron tres parcelas con pasto nicarión bajo sistema silvopastoril y sistema de pastoreo de campo abierto, resultando en 12 parcelas con tres repeticiones. Los parámetros de evaluación fueron el rendimiento (Kg/m2) y el aporte nutricional como proteína, fibra cruda, almidón, azúcares, fibra detergente neutra (FDN) y fibra detergente ácida (FDA). Los datos obtenidos fueron procesados mediante la prueba t-Student al 5% (p&lt;0,05) de significancia. Entre los sistemas de producción se encontraron diferencias significativas en el rendimiento, proteínas, azúcares y la fibra detergente neutra. En cuanto al piso altitudinal se encontraron diferencias significativas en la fibra cruda, azúcares y fibra detergente ácida.</p