A Design Procedure for Lipped Channel Flexural Members

This paper is third in a series of three papers describing the research sponsored by the American Iron and Steel Institute. Physical test results described in the first paper combined with the finite element solution parametric studies described in the second paper were used in this paper to develop improved design procedures for edge stiffened elements

Finite Element Studies on Lipped Channel Flexural Members

This paper is second in a series of three papers describing the research sponsored by the American Iron and Steel Institute. Physical test results described in the first paper combined with the finite element solution parametric studies described in this paper were used in the third paper to develop improved design procedures for edge stiffened elements

Experiments on Lipped Channel Flexural Members

A series of tests were conducted on lipped channel flexural members to study the behavior of edge stiffened elements. The details and the results of these tests as well as tests by others are discussed in this paper. All the test results are compared with those predicted by the AISI Specification

Effect of cutaneous nitroglycerin patches on coronary artery diameter: Issues concerning development of tolerance

AbstractThe coronary dilative and systemic responses to graded doses of intracoronary nitroglycerin were studied in 53 patients undergoing diagnostic coronary arteriography, 43 of whom had received a cutaneous nitroglycerin patch. During coronary arteriography, graded doses of 50, 100 and 200 μg of intracoronary nitroglycerin were given 5 min apart. An arteriogram and hemodynamic measurements were obtained after each dose. In the control group (n = 10) cumulative intracoronary nitroglycerin doses of 50,150 and 350 μg caused an increase in coronary diameter in the left anterior descending artery of 20 ± 4%, 21 ± 3% and 22 ± 7%, respectively, and in the circumflex artery of 18 ± 6%, 23 ± 8% and 18 ± 5% (p < 0.01 versus values in untreated group).In Group 1 (15 patients given a 5 mg/24 h nitroglycerin patch 2 to 12 h before coronary arteriography), the same intracoronary nitroglycerin doses increased the left anterior descending artery diameter by 6 ± 2%, 7 ± 2% and 7 ± 2%, respectively, and the circumflex artery diameter by 3 ± 2%, 3 ± 2% and 1 ± 3%. All values were statistically different from control (p < 0.05). An even more pronounced blunting (p < 0.01) of the coronary dilative response was observed in Group 2 (14 patients given a 15 mg/24 h nitroglycerin patch 2 to 12 h before arteriography). The diameter responses to intracoronary nitroglycerin observed in Group 3 (seven patients given a 5 mg/24 h nitroglycerin patch 24 h before arteriography) and Group 4 (seven patients given a 15 mg/24 h nitroglycerin patch 24 h before arteriography) were not significantly different from those of the control group.The results demonstrate that a nitroglycerin patch administered a few hours before coronary arteriography caused significant coronary artery dilation and that the incremental dilation due to the intracoronary nitroglycerin was small. On the other hand, 24 h after arteriography, the coronary dilative effect of the patch was attenuated (suggesting development of tolerance) and the increment in diameter induced by intracoronary nitroglycerin was much larger

Cultura material y espacios cotidianos: mobiliario y enseres domésticos en la ciudad de Córdoba a fines del siglo XVIII

Dentro del amplio espectro de objetos que conformaron el entrono material cotidiano de los habitantes de la ciudad de Córdoba a fines del siglo XVIII, nos concentraremos en el mobiliario y los enseres domésticos, dejando para otros trabajos el análisis de la vestimenta, los objetos de lujo, los objetos religiosos, la alimentación y la vivienda. Además de ser objetos utilitarios, los muebles reflejan el nivel social de la familia, manifiestan el estilo de vida, valores y personalidad de los dueños de casa. No sólo dejan ver cuestiones de nivel económico, sino también cultural, el ritmo de vida y los hábitos domésticos de los miembros de la familia. El mobiliario y los enseres domésticos están estrechamente ligados con el espacio, es decir, con la vivienda y sus distintas habitaciones, por tal motivo, trataremos de hacernos una imagen de los espacios dentro de la vivienda, los muebles y demás objetos propios de éstas. Cabe destacar que no existió en los hogares cordobeses de fines del siglo XVIII, gran variedad de muebles, y algunos son, como veremos más adelante, comunes a distintas habitaciones, y no propios o específicos de algún cuarto en particular. Las cartas de dote, de capital, los inventarios post mortem y los testamentos, son invaluables fuentes que nos ofrecen una amplia y rica información sobre los diversos objetos propios de las viviendas cordobesas, el trabajo con estos documentos nos permite formarnos una imagen de ese entorno material cotidiano y, trascendiendo lo descriptivo, analizar esos objetos dentro de las prácticas sociales de las que son parte. A partir de la observación de este grupo de objetos pretendemos demostrar que los bienes materiales contribuyen a definir el lugar que se ocupa en la sociedad ya que también tienen un significado social, y la gente los utiliza como elemento de comparación, diferenciación, superación de otros grupos, para expresar individualidad o afinidad, etc.Facultad de Humanidades y Ciencias de la Educació

Risk stratification for arrhythmic death in an emergency department cohort: a new method of nonlinear PD2i analysis of the ECG

Heart rate variability (HRV) reflects both cardiac autonomic function and risk of sudden arrhythmic death (AD). Indices of HRV based on linear stochastic models are independent risk factors for AD in postmyocardial infarction (MI) cohorts. Indices based on nonlinear deterministic models have a higher sensitivity and specificity for predicting AD in retrospective data. A new nonlinear deterministic model, the automated Point Correlation Dimension (PD2i), was prospectively evaluated for prediction of AD. Patients were enrolled (N = 918) in 6 emergency departments (EDs) upon presentation with chest pain and being determined to be at risk of acute MI (AMI) >7%. Brief digital ECGs (>1000 heartbeats, ∼15 min) were recorded and automated PD2i results obtained. Out-of-hospital AD was determined by modified Hinkle-Thaler criteria. All-cause mortality at 1 year was 6.2%, with 3.5% being ADs. Of the AD fatalities, 34% were without previous history of MI or diagnosis of AMI. The PD2i prediction of AD had sensitivity = 96%, specificity = 85%, negative predictive value = 99%, and relative risk >24.2 (p ≤ 0.001). HRV analysis by the time-dependent nonlinear PD2i algorithm can accurately predict risk of AD in an ED cohort and may have both life-saving and resource-saving implications for individual risk assessment