Geophysical and Biological Reconnaissance of Rock Habitats in Western Camden Bay, Beaufort Sea, Alaska

This report presents the results of a 10-day geophysical and biological survey in western Camden Bay, in the Alaskan Beaufort Sea. The primary objective of this survey was to confirm the existence of boulders and cobbles on the seafloor as reported by Barnes (1981, 1982). The survey area extended from the eastern edge of the Canning River (mud flat area) to Kangigivik Point and seaward to the 14m contour line (Fig. 1). A solid boundary of pack ice prevented any survey work seaward of the 14m contour. We had proposed to examine the seabed to the 18m contour.This work was supported by the Bureau of Land Management through an interagency agreement with the National Oceanic and Atmospheric Administration, under which a multiyear program responding to needs of petroleum development of the Alaskan Continental Shelf is managed by the Outer Continental Shelf Environmental Assessment Program (OCSEAP) office

Using Coupled Eulerian and Lagrangian Grids to Model Explosive Interactions with Buildings

This paper presents the development of a computational model that can be used to study the interactions between structures and detonating explosives contained within them. This model was developed as part of an effort to develop a rubble characterization model for use in AmmoSIM, an agent based urban tactical decision aid (UTDA) software for weapon-target pairing. The rubble pile created following the collapse of a building in a combat situation can significantly impact mission accomplishment, particularly in the area of movement and maneuver. The information provided by AmmoSIM will enable both platoon level and command center staff to make informed decisions concerning urban attack tactics. Computational models were created using a combination of AUTODYN 2D and 3D. The detonation was modeled using a 2D wedge, which is a common method used in AUTODYN. The information obtained from the wedge calculation was then written to a data file and subsequently remapped into a larger 3D Euler air grid. The air grid loaded with blast pressure information was coupled to interact with the Lagrangian building parts. The Riedel, Hiermaier and Thoma (RHT) Concrete Model from the AUTODYN material library was utilized to create the components of the building. Results of the latest models will be given. Additionally, the paper details the development of the model at length including topics such as grid sizing, computational cost comparisons, grid interactions, multi-solver coupling, strain erosion, and material parameters and selections

An augmented Young-Laplace model of an evaporating meniscus in a micro-channel with high heat flux

High flux evaporations from a steady meniscus formed in a 2 micron channel is modeled using the augmented Young-Laplace equation. The heat flux is found to be a function of the long range van der Waals dispersion force which represents interfacial conditions between heptane and various substrates. Heat fluxes of (1.3-1.6) x 10(exp 6) W/m(exp 2) based on the width of the channel are obtained for heptane completely wetting the substrate at 100 C. Small channels are used to obtain these large fluxes. Even though the real contact angle is 0 deg, the apparent contact angle is found to vary between 24.8 deg and 25.6 deg. The apparent contact angle, which represents viscous losses near the contact line, has a large effect on the heat flow rate because of its effect on capillary suction and the area of the meniscus. The interfacial heat flux is modeled using kinetic theory for the evaporation rate. The superheated state depends on the temperature and the pressure of the liquid phase. The liquid pressure differs from the pressure of the vapor phase due to capillarity and long range van der Waals dispersion forces which are relevant in the ultra think film formed at the leading edge of the meniscus. Important pressure gradients in the thin film cause a substantial apparent contact angle for a complete wetting system. The temperature of the liquid is related to the evaporation rate and to the substrate temperature through the steady heat conduction equation. Conduction in the liquid phase is calculated using finite element analysis except in the vicinity of the thin film. A lubrication theory solution for the thin film is combined with the finite element analysis by the method of matched asymptotic expansions

Water vapor emission from IRC+10216 and other carbon-rich stars: model predictions and prospects for multitransition observations

We have modeled the emission of H2O rotational lines from the extreme C-rich star IRC+10216. Our treatment of the excitation of H2O emissions takes into account the excitation of H2O both through collisions, and through the pumping of the nu2 and nu3 vibrational states by dust emission and subsequent decay to the ground state. Regardless of the spatial distribution of the water molecules, the H2O 1_{10}-1_{01} line at 557 GHz observed by the Submillimeter Wave Astronomy Satellite (SWAS) is found to be pumped primarily through the absorption of dust-emitted photons at 6 $\mu$m in the nu2 band. As noted by previous authors, the inclusion of radiative pumping lowers the ortho-H2O abundance required to account for the 557 GHz emission, which is found to be (0.5-1)x10^{-7} if the presence of H2O is a consequence of vaporization of orbiting comets or Fischer-Tropsch catalysis. Predictions for other submillimeter H2O lines that can be observed by the Herschel Space Observatory (HSO) are reported. Multitransition HSO observations promise to reveal the spatial distribution of the circumstellar water vapor, discriminating among the several hypotheses that have been proposed for the origin of the H2O vapor in the envelope of IRC+10216. We also show that, for observations with HSO, the H2O 1_{10}-1_{01} 557 GHz line affords the greatest sensitivity in searching for H2O in other C-rich AGB stars.Comment: 35 pages, 12 figures, to be published in The Astrophysical Journa

Uncertainty Considerations for Ballistic Limit Equations

The overall risk for any spacecraft system is typically determined using a Probabilistic Risk Assessment (PRA). A PRA determines the overall risk associated with a particular mission by factoring in all known risks to the spacecraft during its mission. The threat to mission and human life posed by the micro-meteoroid and orbital debris (MMOD) environment is one of the risks. NASA uses the BUMPER II program to provide point estimate predictions of MMOD risk for the Space Shuttle and the ISS. However, BUMPER II does not provide uncertainty bounds or confidence intervals for its predictions. In this paper, we present possible approaches through which uncertainty bounds can be developed for the various damage prediction and ballistic limit equations encoded within the Shuttle and Station versions of BUMPER II

The views of older women towards mammographic screening: a qualitative and quantitative study

Purpose: Mammographic screening has improved breast cancer survival in the screened age group. This improved survival has not been seen in older women (>70 years) where screening uptake is low. This study explores the views, knowledge and attitudes of older women towards screening. Methods: Women (>70) were interviewed about breast screening. Interview findings informed the development of a questionnaire which was sent to 1000 women (>70) to quantify their views regarding screening. Results: Twenty-six women were interviewed and a questionnaire designed. The questionnaire response rate was 48.3% (479/992). Over half (52.9%, 241/456) of respondents were unaware they could request mammography by voluntary self-referral and were unaware of how to arrange this. Most (81.5% 383/470) had not attended breast screening since turning 70. Most (75.6%, 343/454) felt screening was beneficial and would attend if invited. Most, (90.1%, 412/457) felt screening should be offered to all women regardless of age or health. Conclusions: There is a lack of knowledge about screening in older women. The majority felt that invitation to screening should be extended to the older age group regardless of age or health. The current under-utilised system of voluntary self referral is not supported by older women

Rubble Pile Characterization Model

Rubble piles created following the collapse of a building in a combat situation can significantly impact mission accomplishment, particularly in the area of movement and maneuver. Rubble characteristics must be known, for example, in order to predict the ability of a vehicle to override the collateral damage from weapon effects in urban areas. Two types of models are developed: a first-order model and a first-principles-based model. In both models, we assume complete rubblization of the building and develop a rubble profile model using the size and composition of the collapsed structure to predict the rubble volume. In both cases, this profile model includes the size of the footprint area surrounding the original building assuming that the rubble is free to expand horizontally as well as the resulting height of such a rubble pile. Empirical data is now needed to verify the predictive capabilities of these models

Lifestyle index for mortality prediction using multiple ageing cohorts in the USA, UK and Europe

Current mortality prediction indexes are mainly based on functional morbidity and comorbidity, with limited information for risk prevention. This study aimed to develop and validate a modifiable lifestyle-based mortality predication index for older adults. Data from 51,688 participants (56% women) aged ≥50 years in 2002 Health and Retirement Study, 2002 English Longitudinal Study of Ageing and 2004 Survey of Health Ageing and Retirement in Europe were used to estimate coefficients of the index with cohort-stratified Cox regression. Models were validated across studies and compared to the Lee index (having comorbid and morbidity predictors). Over an average of 11-year follow-up, 10,240 participants died. The lifestyle index includes smoking, drinking, exercising, sleep quality, BMI, sex and age; showing adequate model performance in internal validation (C-statistic 0.79; D-statistic 1.94; calibration slope 1.13) and in all combinations of internal-external cross-validation. It outperformed Lee index (e.g. differences in C-statistic = 0.01, D-statistic = 0.17, P < 0.001) consistently across health status. The lifestyle index stratified participants into varying mortality risk groups, with those in the top quintile having 13.5% excess absolute mortality risk over 10 years than those in the bottom 50th centile. Our lifestyle index with easy-assessable behavioural factors and improved generalizability may maximize its usability for personalized risk management

Predicting risky choices from brain activity patterns

Previous research has implicated a large network of brain regions in the processing of risk during decision making. However, it has not yet been determined if activity in these regions is predictive of choices on future risky decisions. Here, we examined functional MRI data from a large sample of healthy subjects performing a naturalistic risk-taking task and used a classification analysis approach to predict whether individuals would choose risky or safe options on upcoming trials. We were able to predict choice category successfully in 71.8% of cases. Searchlight analysis revealed a network of brain regions where activity patterns were reliably predictive of subsequent risk-taking behavior, including a number of regions known to play a role in control processes. Searchlights with significant predictive accuracy were primarily located in regions more active when preparing to avoid a risk than when preparing to engage in one, suggesting that risk taking may be due, in part, to a failure of the control systems necessary to initiate a safe choice. Additional analyses revealed that subject choice can be successfully predicted with minimal decrements in accuracy using highly condensed data, suggesting that information relevant for risky choice behavior is encoded in coarse global patterns of activation as well as within highly local activation within searchlights