Standard problems for structural computer codes

BNL is investigating the ranges of validity of the analytical methods used to predict the behavior of nuclear safety related structures under accidental and extreme environmental loadings. During FY 85, the investigations were concentrated on special problems that can significantly influence the outcome of the soil structure interaction evaluation process. Specially, limitations and applicability of the standard interaction methods when dealing with lift-off, layering and water table effects, were investigated. This paper describes the work and the results obtained during FY 85 from the studies on lift-off, layering and water-table effects in soil-structure interaction

Integrated system for seismic evaluations

This paper describes the various features of the Seismic Module of the CARES system (Computer Analysis for Rapid Evaluation of Structures). This system was developed by Brookhaven National Laboratory (BNL) for the US Nuclear Regulatory Commission to perform rapid evaluations of structural behavior and capability of nuclear power plant facilities. The CARES is structured in a modular format. Each module performs a specific type of analysis i.e., static or dynamic, linear or nonlinear, etc. This paper describes the features of the Seismic Module in particular. The development of the Seismic Module of the CARES system is based on an approach which incorporates all major aspects of seismic analysis currently employed by the industry into an integrated system that allows for carrying out interactively computations of structural response to seismic motions. The code operates on a PC computer system and has multi-graphics capabilities. It has been designed with user friendly features and it allows for interactive manipulation of various analysis phases during the seismic design process. The capabilities of the seismic module include (a) generation of artificial time histories compatible with given design ground response spectra, (b) development of Power Spectral Density (PSD) functions associated with the seismic input, (c) deconvolution analysis using vertically propagating shear waves through a given soil profile, and (d) development of in-structure response spectra or corresponding PSD's. It should be pointed out that these types of analyses can also be performed individually by using available computer codes such as FLUSH, SAP, etc. The uniqueness of the CARES, however, lies on its ability to perform all required phases of the seismic analysis in an integrated manner. 5 refs., 6 figs

Prevalence of Pulmonary Embolism in Patients with Syncope

Importance:Sparse data and conflicting evidence exist on the prevalence of pulmonary embolism (PE) in patients with syncope. Objective:To estimate the prevalence of PE among patients presenting to the emergency department (ED) for evaluation of syncope. Design, Setting, and Participants:This retrospective, observational study analyzed longitudinal administrative data from 5 databases in 4 different countries (Canada, Denmark, Italy, and the United States). Data from all adult patients (aged 6518 years) who presented to the ED were screened to identify those with syncope codes at discharge. Data were collected from January 1, 2000, through September 30, 2016. Main Outcomes and Measures:The prevalence of PE at ED and hospital discharge, identified using codes from the International Classification of Diseases, was considered the primary outcome. Two sensitivity analyses considering prevalence of PE at 90 days of follow-up and prevalence of venous thromboembolism were performed. Results: A total of 1\u202f671\u202f944 unselected adults who presented to the ED for syncope were included. The prevalence of PE, according to administrative data, ranged from 0.06% (95% CI, 0.05%-0.06%) to 0.55% (95% CI, 0.50%-0.61%) for all patients and from 0.15% (95% CI, 0.14%-0.16%) to 2.10% (95% CI, 1.84%-2.39%) for hospitalized patients. The prevalence of PE at 90 days of follow-up ranged from 0.14% (95% CI, 0.13%-0.14%) to 0.83% (95% CI, 0.80%-0.86%) for all patients and from 0.35% (95% CI, 0.34%-0.37%) to 2.63% (95% CI, 2.34%-2.95%) for hospitalized patients. Finally, the prevalence of venous thromboembolism at 90 days ranged from 0.30% (95% CI, 0.29%-0.31%) to 1.37% (95% CI, 1.33%-1.41%) for all patients and from 0.75% (95% CI, 0.73%-0.78%) to 3.86% (95% CI, 3.51%-4.24%) for hospitalized patients. Conclusions and Relevance: Pulmonary embolism was rarely identified in patients with syncope. Although PE should be considered in every patient, not all patients should undergo evaluation for PE

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Soil-structure interaction methods. SLAVE code. Volume 2

This report presents a detailed description of SLAVE Code, a program which performs the exact deconvolution analysis for horizontal earthquake ground motions. The objective is to determine the horizonal motion-time histories (accelerograms) which must be input at the basement of a horizontally bedded soil system which will yield the specified surface (or near surface) criteria motion history. In the deconvolution analysis, the soil overburden is represented by a vertical soil column (linear shear beam) to which criteria motion is input at (or near) the top. The accelerogram generated by SLAVE Code at the basement or bottom of the soil column will regenerate this criteria motion when input at the bottom of the soil column. 2 refs

Soil-structure interaction methods, SIM code. Volume III

The Structure In Media (SIM) Code determines the response of a structure, embedded in soil/rock media, to a specified dynamic disturbance in the media. The structure is modeled as a series of lumped mass, elastic beams which may be interconnected with elastic springs. The disturbance in the free field is specified in terms of an accelerogram, the scale of which may vary with depth. Soil/structure interaction is treated in two parts. The first determines the interaction forces developed at the base of the structure while the second evaluates the interaction forces developed along the side walls of the structure. Details of the model are discussed

A report on the seismic capacity of the General Laboratory and Administration Building at Los Alamos National Laboratory

A seismic analysis of the General Laboratory and Administration Building at Los Alamos National Laboratory is performed. The analyses are performed in detail for one portion of the building and then qualitatively extrapolated to other portions of the building. Seismic capacities are evaluated based on two sets of acceptance criteria. The first is based on Code-type criteria and is associated with a low probability of failure. This capacity is found to be in the 0.04--0.06 G ZPA range (the free field seismic motion is defined with a NUREG 0098 response spectrum). The second capacity is based on much less conservative criteria such as might be associated with a high probability of failure. This capacity is found to be about 0.15 G. Finally structural modifications are proposed that would increase the low probability of failure capacity to 0.15 G ZPA. These modifications consist of steel double angle braces or concrete shear walls placed at some of the frames in the building

Seismic response analyses for reactor facilities at Savannah River

The reactor facilities at the Savannah River Plant (SRP) were designed during the 1950's. The original seismic criteria defining the input ground motion was 0.1 G with UBC (uniform building code) provisions used to evaluate structural seismic loads. Later ground motion criteria have defined the free field seismic motion with a 0.2 G ZPA (free field acceleration) and various spectral shapes. The spectral shapes have included the Housner spectra, a site specific spectra, and the US NRC (Nuclear Regulatory Commission) Reg. Guide 1.60 shape. The development of these free field seismic criteria are discussed in the paper. The more recent seismic analyses have been of the following type: fixed base response spectra, frequency independent lumped parameter soil/structure interaction (SSI), frequency dependent lumped parameter SSI, and current state of the art analyses using computer codes such as SASSI. The results from these computations consist of structural loads and floor response spectra (used for piping and equipment qualification). These results are compared in the paper and the methods used to validate the results are discussed. 14 refs., 11 figs

The elevation of circulating fibroblast growth factor 23 without kidney disease does not increase cardiovascular disease risk.

High circulating fibroblast growth factor 23 (FGF23) levels are probably a major risk factor for cardiovascular disease in chronic kidney disease. FGF23 interacts with the receptor FGFR4 in cardiomyocytes inducing left ventricular hypertrophy. Moreover, in the liver FGF23 via FGFR4 increases the risk of inflammation which is also found in chronic kidney disease. In contrast, X-linked hypophosphatemia is characterized by high FGF23 circulating levels due to loss of function mutations of the phosphate-regulating gene with homologies to an endopeptidase on the X chromosome (PHEX), but is not characterized by high cardiovascular morbidity. Here we used a novel murine X-linked hypophosphatemia model, the PhexC733RMhda mouse line, bearing an amino acid substitution (p.Cys733Arg) to test whether high circulating FGF23 in the absence of renal injury would trigger cardiovascular disease. As X-linked hypophosphatemia patient mimics, these mice show high FGF23 levels, hypophosphatemia, normocalcemia, and low/normal vitamin D levels. Moreover, these mice show hyperparathyroidism and low circulating soluble alpha Klotho levels. At the age of 27 weeks we found no left ventricular hypertrophy and no alteration of cardiac function as assessed by echocardiography. These mice also showed no activation of the calcineurin/NFAT pathway in heart and liver and no tissue and systemic signs of inflammation. Importantly, blood pressure, glomerular filtration rate and urea clearance were similar between genotypes. Thus, the presence of high circulating FGF23 levels alone in the absence of renal impairment and normal/high phosphate levels is not sufficient to cause cardiovascular disease