The Safety Barrier Dilemma

Ran-off-the-road fatal accidents currently account for approximately 65 percent of all freeway fatalities (1). Accordingly, ever-increasing emphasis has been given to the development of effective safety barrier systems, from guardrails to earth berms to median barriers to energy absorbing barriers and mires. However, highway designers have also recognized that safety barriers are hazards in themselves, misfits in the highway environment, and that they are items to be eliminated wherever possible. In a study of fatal accidents on the Interstate Highway System, it was found that fixed object collisions have been the leading source of fatalities, accounting for 43 percent of the 1968-1969 fatal accidents (2). Ironically, guardrails were found to be the most frequent objects struck first -- accounting for 31 percent of the total. Furthermore, this same study estimates that, excluding non-interstate and secondary urban roads, 6,300 miles of guardrail were constructed on public roads in 1969. Statistics such as these illustrate the risks facing today\u27s drivers on the Interstate Highway System. Until a major modification is made that produces a significant reduction in such risks, less mobility (through travel restrictions) will be required to produce a significant reduction in fatalities per year (3)

Screening For Maternal Postpartum Depression In The Pediatric Primary Care Setting: An Educational Project

Abstract The birth of a baby can bring about an array of powerful emotions that range from joy and excitement to feelings of anxiety, worry, and depression. A majority of mothers experience postpartum baby blues which normally begins 2-3 days after delivery and can last for up to 2-3 weeks, but some mothers experience a more severe form known as postpartum depression (PPD). PPD can be mistaken for baby blues at first, but the signs and symptoms do not diminish and can continue to worsen. Postpartum depression signs and symptoms include withdrawing from friends and family, severe mood swings, excessive crying, increased or decreased appetite, loss of interest or pleasure in doing things, and difficulty bonding or making a connection with the newborn (Mayo Clinic, 2022). PPD can also lead to suicidal ideation as well as thoughts of harming the infant. If left untreated, this can increase the baby’s risk for developmental delays and impaired social development. Given the effects that PPD can have on the mother and infant, it is vital that this diagnosis is caught and treated early, but unfortunately there are women who miss their postpartum follow-up appointment with their obstetrician. The American Academy of Pediatrics recognized this gap in missed diagnoses and recommended that pediatric providers screen for maternal PPD at the 1, 2, 4, and 6- month well-child visits (Morehead, 2020). The two project sites do not follow this recommendation, so an educational PowerPoint focusing on the epidemiology of PPD, validated screening tools, and the significance of PPD was presented to the pediatric providers and data from the pre-test and post-test survey were analyzed. Although not statistically significant, the educational intervention had an impact on their knowledge relating to postpartum depression

Experimental Installations of Impact-Attenuating Devices

From a survey of the interstate system in Kentucky, 26 gore sites were found to be eligible for safety improvements. Energy absorbing barriers have been installed at five. Barriers are planned at 11 sites; seven sites have been contour graded; and three sites have been dismissed from consideration. HI-DRO Cushions and Fitch Inertial Barriers were found to be effective crash cushions. HI-DRO Cushion maintenance costs per impact were less than those for Fitch Inertial Barriers; however, initial costs of materials and installation were higher. The HI-DRO Cushion is generally more adaptable to narrow and relatively short areas than either the Fitch Inertial Barrier or the Steel Crash Cushion. Desirability of redirectional capabilities is dependent upon site geometrics, traffic volumes, and speeds. If there is no feasible alternative, installation of an impact attenuating device is advocated in terms of warrants

Symmetry Scheme for Amino Acid Codons

Group theoretical concepts are invoked in a specific model to explain how only twenty amino acids occur in nature out of a possible sixty four. The methods we use enable us to justify the occurrence of the recently discovered twenty first amino acid selenocysteine, and also enables us to predict the possible existence of two more, as yet undiscovered amino acids.Comment: 18 pages which include 4 figures & 3 table

An Operational Analysis of the I 64, I 65, I 71 Route Junction in Louisville

The Kennedy Interchange in Louisville is the most geometrically complicated of any in Kentucky; it is the junction of three interstate routes, I 64, I 65, and I 71. The many diverging, weaving, and merging movements demand a driver\u27s attention. One merging situation collapses into an impasse during peak-hour traffic. This study is responsive to certain inquiries by the Department concerning safety and possible discovery of design deficiencies at this interchange. It was not intended to be an in-depth study but rather an exploratory identification of problems and their locations; more comprehensive studies, by others, would ensue if needed. The specific objectives were to discover conflicts and erratic movements and to locate and analyze high-frequency accident sites

Flowfield Uncertainty Analysis for Hypersonic CFD Simulations

Uncertainty quantification (UQ) in the hypersonic flow regime offers valuable information to determine physical models in need of improvement and to assist in design of vehicles and flight experiments. Here we present results of UQ analysis based on polynomial chaos method to determine flowfield and surface heat flux uncertainty under typical blunt-body re-entry conditions. The NASA Langley code, LAURA, was used for axisymmetric CFD calculations of chemically reacting hypersonic flow over FIRE-II configuration. A third order polynomial chaos (PC) method using the Gauss-Hermite quadrature was applied for determining probability density functions and moments of output quantities. Input parameters such as freestream density, velocity, and temperature were varied and the propagation of their corresponding uncertainties on output properties of interest through the flowfield were studied. An order of magnitude increase in surface heat flux uncertainties was observed for an input freestream velocity uncertainty of ±100 ft/s, or 0.29%. This parameter thus has the greatest sensitivity to variations, and conversely the freestream temperature has the least sensitivity

2-Dust : a Dust Radiative Transfer Code for an Axisymmetric System

We have developed a general purpose dust radiative transfer code for an axisymmetric system, 2-Dust, motivated by the recent increasing availability of high-resolution images of circumstellar dust shells at various wavelengths. This code solves the equation of radiative transfer following the principle of long characteristic in a 2-D polar grid while considering a 3-D radiation field at each grid point. A solution is sought through an iterative scheme in which self-consistency of the solution is achieved by requiring a global luminosity constancy throughout the shell. The dust opacities are calculated through Mie theory from the given size distribution and optical properties of the dust grains. The main focus of the code is to obtain insights on (1) the global energetics of dust grains in the shell (2) the 2-D projected morphologies that are strongly dependent on the mixed effects of the axisymmetric dust distribution and inclination angle of the shell. Here, test models are presented with discussion of the results. The code can be supplied with a user-defined density distribution function, and thus, is applicable to a variety of dusty astronomical objects possessing the axisymmetric geometry.Comment: To be published in ApJ, April 2003 issue; 13 pages, 4 tables, 17 figures, 5-page appendix (no figures for the main text included in this preprint). For the complete preprint and code distribution, contact the author

Experimental Installations of Impact Attenuation Devices

The expanding system of limited access, multilane highway facilities in the United States has enhanced traffic service between many varied origins and destinations. As a result, these facilities have not only reduced travel times and travel costs, but have generated additional travel by virtue of their technological splendor. The increasing dominance of multilane highways in terms of percentage of total vehicle miles travelled has produced a revolution in highway engineering philosophy. Higher design speeds, increased lane widths, lateral separation of opposing traffic streams, absence of passing restrictions, and increased traffic capacities were attributes intuitively sought. An ironic result is the emergence of new accident styles on roadways which had as their specific purpose the reduction of accidents. Dominant among these new styles was the single vehicle ran off the road type. Recent investigations have shown that this accident mode may be the largest single contributor to fatalities on limited access, multilane facilities. Contributing to the preponderance of this accident type are some seemingly minor but potentially deadly elements of the roadway. Previous studies have been concerned with bridge piers located in the median, the location of median crossovers, and the horizontal and vertical dimensions of medians themselves. Problems have been created by rigidly fixed objects such as bridge walls or massive sign standard bases located in the gore area of bifurcating roadways and exit ramps

The use of paleoclimate simulations to refine the environmental and chronological context of archaeological/paleontological sites

This study illustrates the strong potential of combining paleoenvironmental reconstructions and paleoclimate modeling to refine the paleoenvironmental and chronological context of archaeologicaland paleontological sites. We focus on the El Harhoura 2 cave (EH2), an archeological site located on the North-Atlantic coast of Morocco that covers a period from the Late Pleistocene to the mid-Holocene. On several stratigraphic layers, inconsistencies are observed between species- and isotope-based inferences used to reconstruct paleoenvironmental conditions. The stratigraphy of EH2 also shows chronological inconsistencies on older layers between age estimated by Optical Stimulated Luminescence (OSL) and Combination of Uranium Series and Electron Spin Resonance methods (combined US-ESR). We performed paleoclimate simulations to infer the global paleoclimate variations over the EH2 sequence in the area, and we conducted a consistency approach between paleoclimatereconstruction estimated from simulations and available from EH2 paleoenvironmental inferences. Our main conclusion show that the climate sequence based on combined US-ESR ages is more consistent with paleoenvironmental inferences than the climate sequence based on OSL ages. We also evidence that isotope-based inferences are more congruent with the paleoclimate sequence than species-based inferences. These results highlight the difference in scale between the information provided by each ofthese paleoenvironmental proxies. Our approach is transferable to other sites due to the increase number of available paleoclimate simulations.1 Introduction 2 Material and methods 2.1 El Harhoura 2 cave 2.1.1 Presentation of the site 2.1.2 Chronostratigraphy and dating hypotheses 2.1.3 Paleoenvironmental variables 2.2 Paleoclimate reconstruction 2.2.1 Climate model 2.2.2 Paleoclimate simulations 2.2.3 Sea-surface boundary conditions 2.2.4 A subset of key paleoclimate variables 2.3 Consistency analyses 3 Results 3.1. Simulated climate changes 3.2 Consistency between paleoclimate simulations and paleoenvironmental inferences 3.2.1 Association of paleoclimate simulations and stratigraphic layers 3.2.2 Consistency analyses 4 Discussion 4.1 Paleoclimate variation and underlying forcings 4.2 Paleoclimate simulations and chronostratigraphy 4.3 Paleoclimate simulations and paleoenvironmental inferences 5 Conclusion