Proceedings for the ICASE Workshop on Heterogeneous Boundary Conditions

Domain Decomposition is a complex problem with many interesting aspects. The choice of decomposition can be made based on many different criteria, and the choice of interface of internal boundary conditions are numerous. The various regions under study may have different dynamical balances, indicating that different physical processes are dominating the flow in these regions. This conference was called in recognition of the need to more clearly define the nature of these complex problems. This proceedings is a collection of the presentations and the discussion groups

Validation of computational fluid-structure interaction models by comparison with collapsible tube experiments.

The objective of this thesis was to assess the validity of the fluid-structure interaction (FSI) facilities in LS-DYNA for the analysis of highly deformable structures interacting with flowing viscous fluids. The collapsible tube experiment was chosen as a validation tool for FSI since its three-dimensional computational modelling would have been impossible if the viscous internal fluid flow were not considered. An explicit three-dimensional finite element model of a collapsible-tube was constructed and solved using LS-DYNA. The fully coupled model included internal fluid flow; external, inlet and outlet pressures; tube wall tension; pre-stressing; and contact. The finite element boundary conditions were taken as the recorded values of flow rate and pressure from a standard collapsible-tube experiment for both steady and unsteady flows. The predicted tube geometry in the steady LS-DYNA model showed good agreement with the experiment for operating points in the highly compliant region of the pressure-flow characteristic curve. The comparative position of the pinch at the outlet end differed by only 5.6% of the outlet diameter in the worst case. This analysis represents an advance on other published work in that previously no comparison with experiments have been drawn for FSI models involving high Reynolds number flowing viscous fluids interacting with highly deformable three dimensional structures. This analysis successfully made that comparison and the experimental and computational results have combined to form a more detailed picture of the collapsible-tube phenomenon by including detailed stress results of the tube walls and views of the internal fluid flow. The collapsible tube model exhibited uncertainty errors due to the use of a coarser than desirable mesh and a reduced fluid speed of sound. Although both these approximations caused significant error in the model both were necessary in order to achieve acceptable solution times. Because of these errors a thorough quantitative validation could not be achieved although LS-DYNA has been proven to be qualitatively accurate. Increases in computing speed are required before thorough quantitative validation of FSI can be achieved by comparison with the collapsible tube experiments

Root-Cause Analysis of Persistently High Maternal Mortality in a Rural District of Indonesia: Role of Clinical Care Quality and Health Services Organizational Factors

Background: Despite significant reduction in maternal mortality, there are still many regions in the world that suffer from high mortality. District Kutai Kartanegara, Indonesia, is one such region where consistently high maternal mortality was observed despite high rate of delivery by skilled birth attendants.Method: Thirty maternal deaths were reviewed using verbal autopsy interviews, terminal event reporting, medical records\u27 review, and Death Audit Committee reports, using a comprehensive root-cause analysis framework including Risk Identification, Signal Services, Emergency Obstetrics Care Evaluation, Quality, and 3 Delays.Findings: The root causes were found in poor quality of care, which caused hospital to be unprepared to manage deteriorating patients. In hospital, poor implementation of standard operating procedures was rooted in inadequate skills, lack of forward planning, ineffective communication, and unavailability of essential services. In primary care, root causes included inadequate risk management, referrals to facilities where needed services are not available, and lack of coordination between primary healthcare and hospitals.Conclusion: There is an urgent need for a shift in focus to quality of care through knowledge, skills, and support for consistent application of protocols, making essential services available, effective risk assessment and management, and facilitating timely referrals to facilities that are adequately equipped

Histopathological variation in keratoconus

During examination of 131 penetrating keratoplasty specimens from patients with keratoconus obtained in an 11-year period, we observed two histopathologic variants based on the appearance of Bowman\u27s layer and the corneal epithelium. Typical keratoconus specimens had multiple breaks in Bowman\u27s layer and central epithelial thinning, whereas atypical corneas lacked breaks in Bowman\u27s layer and had less thinning of the central epithelium. Ninety-five corneas were from patients who underwent grafting in only one eye. Seventy-six (80%) of these corneas were typical and 19 corneas (20%) were atypical in appearance. Both variants had similar degrees of central stromal thinning. Patients with typical and atypical corneas differed demographically by race only; 49% of typical and 95% of atypical corneas were from white individuals. Thirty-six corneas were from 18 patients who underwent bilateral penetrating keratoplasty. The histologic appearance of these corneal pairs was concordant in 13 patients and discordant (one typical and one atypical cornea) in five patients. Statistical analysis indicated that this distribution is not significantly different from that predicted by chance and suggests that typical and atypical corneas are manifestations of the same disease process

Problems of Western Cooperatives in Obtaining and Distributing Fertilizer

Report Objectives: This report is designed to furnish information to management of farmers' cooperatives for use in appraising economic aspects of transportation costs in developing a fertilizer manufacturing program. In general, it provides basic data on long range problems relating to fertilizer manufacturing and distributing programs. In this way it furnishes background information useful to management. Specifically the objectives of this report are to: 1. Describe general fertilizer operations of regional cooperatives in the Western States, giving special attention to manufacturing and distributing; 2. Present economic data showing the role of cooperatives in the fertilizer industry of the region; and 3. Provide statistical information useful in appraising transportation problems encountered in procuring raw materials for manufacturing fertilizer, and useful in developing a long range program for coordinating the efforts of the agencies serving farmers