IMECE2005-79838 ENERGY DISSIPATION WITH SLOSHING FOR ABSORBER DESIGN

ABSTRACT Sloshing is the low frequency oscillation of the free surface of a liquid in a partially full container. Due to its detrimental effects, efforts are usually made in the direction of suppressing sloshing. In addition, intentionally induced sloshing may be employed as an effective energy sink to provide protection for resonant structures exposed to excessive vibration levels. It is generally reported that sloshing absorbers with shallow levels of liquid are more effective energy dissipators than those with deep levels. However, there has not yet been a study to reveal the mechanism of energy dissipation for practical applications, although there has been ample empirical proof for effectiveness. One of the limitations from a numerical perspective lies with the difficulty in predicting extreme free surface behaviour by traditional grid based computational methods. The objective of this paper is to report initial observations in this direction using Smoothed Particle Hydrodynamics (SPH). SPH is a Lagrangian method of solving the equations for fluid flow, that is suitable for modeling free surface phenomena such as sloshing due to its grid-free nature. Results are reported in this paper in the form of numerical case studies

FEDSM2002-31066 PITFALLS OF HOT-WIRE MEASUREMENTS DUE TO TRANSVERSE WIRE VIBRATION

ABSTRACT Following from numerical predictions and large scale experimental verification, flow measurements are presented to show the effect of transverse wire vibrations on spectral measurements. It has been shown previously that if the first and second natural frequencies of a probe wire are close, it is expected to have favorable dynamic characteristics in turbulent flow. This expectation is confirmed with flow measurements. Further, the traditional sensing length to diameter ratio is reexamined for small scale measurements

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L-1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4 degrees C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature.Peer reviewe

A snapshot of geriatric infections in Turkey: ratio of geriatric inpatients in hospitals and evaluation of their infectious diseases: A multicenter point prevalence study

Introduction: The human population is aging at an astonishing rate. The aim of this study is to capture a situation snapshot revealing the proportion of individuals aged 65 years and over among inpatients in healthcare institutions in Turkey and the prevalence and type of infections in this patient group in order to draw a road map. Materials and Methods: Hospitalized patients over 65 years at any of the 62 hospitals in 29 cities across Turkey on February 9, 2017 were included in the study. Web-based SurveyMonkey was used for data recording and evaluation system. Results: Of 17,351 patients 5871 (33.8%) were ≥65 years old. The mean age was 75.1 ± 7.2 years; 3075 (52.4%) patients were male. Infection was reason for admission for 1556 (26.5%) patients. Pneumonia was the most common infection. The median length of hospital stay was 5 days (IQR: 2–11 days). The Antibiotic therapy was initiated for 2917 (49.7%) patients at the time of admission, and 23% of the antibiotics prescribed were inappropriate. Healthcare-associated infections developed in 1059 (18%) patients. Urinary catheters were placed in 2388 (40.7%) patients with 7.5% invalid indication. Conclusion: This study used real data to reveal the proportion of elderly patients in hospital admissions. The interventions done, infections developed during hospitalization, length of hospital stay, and excessive drug load emphasize the significant impact on health costs and illustrate the importance of preventive medicine in this group of patients. © 2020 The Author

Stratification strength and light climate explain variation in chlorophyll a at the continental scale in a European multilake survey in a heatwave summer

To determine the drivers of phytoplankton biomass, we collected standardized morphometric, physical, and biological data in 230 lakes across the Mediterranean, Continental, and Boreal climatic zones of the European continent. Multilinear regression models tested on this snapshot of mostly eutrophic lakes (median total phosphorus [TP] = 0.06 and total nitrogen [TN] = 0.7 mg L−1), and its subsets (2 depth types and 3 climatic zones), show that light climate and stratification strength were the most significant explanatory variables for chlorophyll a (Chl a) variance. TN was a significant predictor for phytoplankton biomass for shallow and continental lakes, while TP never appeared as an explanatory variable, suggesting that under high TP, light, which partially controls stratification strength, becomes limiting for phytoplankton development. Mediterranean lakes were the warmest yet most weakly stratified and had significantly less Chl a than Boreal lakes, where the temperature anomaly from the long-term average, during a summer heatwave was the highest (+4°C) and showed a significant, exponential relationship with stratification strength. This European survey represents a summer snapshot of phytoplankton biomass and its drivers, and lends support that light and stratification metrics, which are both affected by climate change, are better predictors for phytoplankton biomass in nutrient-rich lakes than nutrient concentrations and surface temperature