A winning strategy for managing simulation projects

In this paper a winning strategy for conducting successful simulation studies is proposed. The proposed approach emphasizes risk reduction through incremental model development and encourages user commitment through team work. A case study, based on a medium-sized manufacturing facility in Missouri, is used to illustrate its application. This successful strategy can be easily adopted on other similar simulation studies.     

Cognitive efficiency in alcoholics and polysubstance abusers

Phosphomannose isomerase (PMI) deficiency is the cause of a new type of carbohydrate-deficient glycoprotein syndrome (CDGS). The disorder is caused by mutations in the PMI1 gene. The clinical phenotype is characterized by protein-losing enteropathy, while neurological manifestations prevailing in other types of CDGS are absent. Using standard diagnostic procedures, the disorder is indistinguishable from CDGS type Ia (phosphomannomutase deficiency). Daily oral mannose administration is a successful therapy for this new type of CDG syndrome classified as CDGS type Ib.     

Full‐scale in situ bioremediation of hexachlorocyclohexane‐contaminated soil

Daramend bioremediation technology was used to treat 1100 tonnes of hexachlorocyclohexane (HCH)‐contaminated soil at a former lindane manufacturing plant. Half of the site (area A) was treated using a cycled anoxic/oxic treatment, and the other half (area B) was treated under oxic conditions. Each area was divided east to west into five zones. A control area (area C) consisted of strips of soil along the north and east edges of the site. Total HCH concentrations along a west to east gradient ranged from 22 430 to 1069 mg kg^?1 in area A and from 21 100 to 730 mg kg^?1 in area B. Concentrations in area C ranged from 52 to 1427 mg kg^?1. The soil was treated for 371 days, during which time seven anoxic/oxic cycles were completed in area A and regular tillage was performed on area B. Soil samples (one per zone) were collected after 154 and 371 days of treatment. After 371 days, total HCH concentrations were reduced in the most highly contaminated zones of areas A and B by 60% (from 22 430 to 8910 mg kg^?1) and 75% (from 21 100 to 5120 mg kg^?1), respectively. The average HCH reductions for all five zones of areas A and B were 40 and 47%, respectively, with the data indicating decreased concentrations of selected isomers in certain zones of both areas. Less substantial changes in HCH concentrations were observed in control area C. Elevated chloride ion concentrations were observed in zones that had demonstrated HCH removal. This full scale project demonstrated the potential for solid phase bioremediation treatment of soil containing high HCH concentrations. Copyright © 2005 Society of Chemical Industry     

Physical disability and social interaction: factors associated with low social contact and home confinement in disabled older women (The Women's Health and Aging Study)

OBJECTIVES: This study examines the association of disability and social interaction, measured as in-person contact with non-household members and home confinement, and identifies sociodemographic, socioeconomic, and health-related factors that modify this relationship. METHODS: Participants were 1,002 moderately to severely disabled community-dwelling women aged 65 and older from the Women's Health and Aging Study, identified by screening an age-stratified random sample of Medicare beneficiaries in Baltimore, Maryland. Logistic regression models were used to estimate the odds of low social interaction associated with disability and each independent modifier. RESULTS: In a typical week, 23% did not visit with anyone residing outside their households and 17% did not leave their homes. In addition to and independent of disability level, older age, not completing high school, having a driver in the home, hearing difficulties and incontinence were associated with low social contact; older age and African American race were related to home confinement. African American women living alone are especially vulnerable to home confinement. DISCUSSION: Physical disability is not necessarily socially disabling, as many of the most severely disabled in our study had at least daily social interaction. Improvements in social interaction appear possible through more effective management of certain health conditions and attention to potential sociocultural barriers.     

Adsorption of3He on cesium

Adsorption isotherms of³He on cesium substrates have been measured in the temperature range from 0.2 K to 1.5 K. At liquid-vapor coexistence³He wets cesium at all temperatures studied. Step-like features are found in the isotherms which are similar to the prewetting transitions of⁴He on Cs substrates, but the width of these steps is ∼20 times wider for³He than for⁴He. In the case of³He on Cs, the steps are located at a chemical potential about 0.6 K below liquid-vapor coexistence. If the low temperature behavior is interpreted to be first order prewetting, the prewetting critical point temperature is 0.6±0.1 K.     

Evaluation of Silicon-Nitride Ceramic Valves

Silicon-nitride ceramic valves can improve the performance of both light- and heavy-duty automotive engines because of the superior material properties of silicon nitrides over current metal alloys. However, ceramics are brittle materials that may introduce uncertainties in the reliability and durability of ceramic valves. As a result, the lifetime of ceramic valves are difficult to predict theoretically due to wide variations in the type and distribution of microstructural flaws in the material. Nondestructive evaluation (NDE) methods are therefore required to assess the quality and reliability of these valves. Because ceramic materials are optically translucent and the strength-limiting flaws are normally located near the valve surface, a laser-scatter method can be used for NDE evaluation of ceramic valves. This paper reviews the progress in the development of this NDE method and its application to inspect silicon-nitride ceramic valves at various stages of manufacturing and bench and engine tests.     

A Flow-Through Dissolution Approach to In Vivo/In Vitro Correlation of Adinazolam Release from Sustained Release Formulations

A Copley^TM fraction collector and a Disotest^TM flow-through system were coupled to provide an automatic discrete sampling flow-through dissolution system for use both in the “open-loop” and “closed-loop” mode. The system was used to investigate the release characteristics of adinazolam in sustained release formulations using a pH 1.2 simulated gastric fluid (without enzymes) dissolution medium (USP XXI). These experimental formulations are designed to provide relatively slow to rapid drug release. The dissolution effluent was analysed off-line by reverse phase HPLC to determine the adinazolam concentration at programmed timed intervals. The differential dissolution profiles produced when the system is used in the “open-loop” configuration are more discriminating in describing the release characteristics of the formulations according to the relative release rates than the “closed-loop” cumulative profiles. Using the characteristic dissolution time parameter from the Weibull function, a better correlation with in vivo bioavailability data was achieved for the data from the system in the “open-loop” mode than when it was used in the “closed-loop” mode. In the “open-loop” mode the Weibull function characteristic dissolution time parameter yielded the best quantitative correlation with a correlation coefficient of 0.92 compared to a value of 0.85 for the “closed-loop” configuration