Motivation, money and respect: a mixed-method study of Tanzanian non-physician clinicians.

Poor quality of care is a major concern in low-income countries, and is in part attributed to low motivation of healthcare workers. Non-physician clinicians (mid-level cadre healthworkers) are central to healthcare delivery in half of the countries in Africa, but while much is expected from these clinicians, little is known about their expectations and motivation to perform well. Understanding what motivates these healthworkers in their work is essential to provide an empirical base for policy decisions to improve quality of healthcare. In 2006-2007, we conducted a mixed-method study to evaluate factors affecting motivation, including reasons for varying levels of motivation, amongst these clinicians in Tanzania. Using a conceptual framework of 'internal' and 'environmental' domains known to influence healthworker motivation in low-income countries, developed from existing literature, we observed over 2000 hospital consultations, interviewed clinicians to evaluate job satisfaction and morale, then designed and implemented a survey instrument to measure work motivation in clinical settings. Thematic analysis (34 interviews, one focus group) identified social status expectations as fundamental to dissatisfaction with financial remuneration, working environments and relationships between different clinical cadres. The survey included all clinicians working in routine patient care at 13 hospitals in the area; 150 returned sufficiently complete data for psychometric analysis. In regression, higher salary was associated with 'internal' motivation; amongst higher earners, motivation was also associated with higher qualification and salary enhancements. Salary was thus a clear prerequisite for motivation. Our results are consistent with the hypothesis that non-salary motivators will only have an effect where salary requirements are satisfied. As well as improvements to organisational management, we put forward the case for the professionalization of non-physician clinicians

Pressurization System Modeling for a Generic Bimese Two- Stage-to-Orbit Reusable Launch Vehicle

A pressurization system model was developed for a generic bimese Two-Stage-to-orbit Reusable Launch Vehicle using a cross-feed system and operating with densified propellants. The model was based on the pressurization system model for a crossfeed subscale water test article and was validated with test data obtained from the test article. The model consists of the liquid oxygen and liquid hydrogen pressurization models, each made up of two submodels, Booster and Orbiter tank pressurization models. The tanks are controlled within a 0.2-psi band and pressurized on the ground with ambient helium and autogenously in flight with gaseous oxygen and gaseous hydrogen. A 15-psi pressure difference is maintained between the Booster and Orbiter tanks to ensure crossfeed check valve closure before Booster separation. The analysis uses an ascent trajectory generated for a generic bimese vehicle and a tank configuration based on the Space Shuttle External Tank. It determines the flow rates required to pressurize the tanks on the ground and in flight, and demonstrates the model's capability to analyze the pressurization system performance of a full-scale bimese vehicle with densified propellants

Diesel Fuel Additives: Use and Efficacy for Alaska's Diesel Generators

Stakeholder Advisory Committee - ii List of Figures - v List of Tables - vi Executive Summary - vii Introduction - 1 Premise - 1 Approach - 1 Background and Literature Review - 2 Diesel Fuel - 2 ASTM D975 Standard Specification for Diesel Fuel Oils - 3 What Are Diesel Fuel Additives? - 5 EPA Registration of Diesel Fuel Additives - 5 Classification of Additives - 5 Diesel Fuel Additive Descriptions and their Uses - 6 Pour Point Depressants - 6 Alternative Cold Flow Improvers - 7 Conductivity Improvers - 7 Lubricity Additives - 7 Biocides - 9 Fuel Stabilizers - 9 Cetane Enhancers - 10 Injector Cleaners - 10 Water Emulsifier/De-emulsifier - 11 Additives to Reduce Emissions - 12 Efficiency - 14 Efficiency increasing Additives and Devices - 15 Magnetic Fuel Conditioners - 15 Combustion Catalysts - 15 Older Versus Newer Engines - 16 Well-Maintained Versus Less Well-Cared-For Engines - 16 EPA Emission Guidelines - 16 Engine Manufacturer Statements on Fuel Additives - 18 Analyses of Available Literature - 19 Experiences of Alaska Utilities - 20 Data Collection Methods Used in this Study - 20 Diesel Electric Generators used in Rural Alaska - 21 Fuel Survey Results - 22 Diesel Fuel Purchase and Delivery Systems in Alaska - 22 Sources of Fuel - 23 Delivery of Fuel in Rural Alaska - 23 Aftermarket Additives Survey Results - 23 Pour Point Depressant Use - 25 Lubricity Additives - 26 Biocides - 26 Long-term Fuel Storage Issues-Especially Water in Fuel - 26 Additive Blending Procedures - 26 Testing of Aftermarket Additives by Alaska Utilities - 30 Age of Diesel Engines used for Testing Additives - 30 Efficiency Enhancing Additives - 30 Efficiency Enhancing Devices - 32 Used Oil - 32 Which Utilities Use Additives? 0 32 Discussion of Additive Use by Alaska Diesel Engine Utilities - 32 Experience of Fuel Suppliers in Alaska - 33 Conclusions - 34 Recommendations - 34 Glossary - 35 References - 3

Additions to the Staphylinidae (Coleoptera) of the Cayman Islands

In 1947, 20 species of Staphylinidae were reported from the Cayman Islands as a result of an Oxford University expedition there in 1938 which made extensive use of a light trap. The list is here expanded to 62 spe­cies based on collections by R. R. Askew, G. E. Ball, E. A. Dilbert, B. K. Dozier, E. J. Gerberg, P. J. Fitzgerald, M. C. Thomas, and R. H. Turnbow since 1970, all of whom also used light traps except for a collection or two by flight intercept trap

CFD Modeling of Helium Pressurant Effects on Cryogenic Tank Pressure Rise Rates in Normal Gravity

A recently developed computational fluid dynamics modeling capability for cryogenic tanks is used to simulate both self-pressurization from external heating and also depressurization from thermodynamic vent operation. Axisymmetric models using a modified version of the commercially available FLOW-3D software are used to simulate actual physical tests. The models assume an incompressible liquid phase with density that is a function of temperature only. A fully compressible formulation is used for the ullage gas mixture that contains both condensable vapor and a noncondensable gas component. The tests, conducted at the NASA Marshall Space Flight Center, include both liquid hydrogen and nitrogen in tanks with ullage gas mixtures of each liquid's vapor and helium. Pressure and temperature predictions from the model are compared to sensor measurements from the tests and a good agreement is achieved. This further establishes the accuracy of the developed FLOW-3D based modeling approach for cryogenic systems

Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks

A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in normal gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-31) software. Quantitative model validation is ,provided by engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage_ Technology Demonstrator (STUSTD) program. The engineering checkout tests provide cryogenic tank self-pressurization test data at various heat leaks and tank fill levels. The predicted self-pressurization rates, ullage and liquid temperatures at discrete locations within the STUSTD tank are in good agreement with test data. The work presented here advances current CFD modeling capabilities for cryogenic pressure control and helps develop a low cost CFD-based design process for space hardware

Cryogenic Pressure Control Modeling for Ellipsoidal Space Tanks in Reduced Gravity

A computational fluid dynamics (CFD) model is developed to simulate pressure control of an ellipsoidal-shaped liquid hydrogen tank under external heating in low gravity. Pressure control is provided by an axial jet thermodynamic vent system (TVS) centered within the vessel that injects cooler liquid into the tank, mixing the contents and reducing tank pressure. The two-phase cryogenic tank model considers liquid hydrogen in its own vapor with liquid density varying with temperature only and a fully compressible ullage. The axisymmetric model is developed using a custom version of the commercially available FLOW-3D software and simulates low gravity extrapolations of engineering checkout tests performed at Marshall Space Flight Center in 1999 in support of the Solar Thermal Upper Stage Technology Demonstrator (STUSTD) program. Model results illustrate that stable low gravity liquid-gas interfaces are maintained during all phases of the pressure control cycle. Steady and relatively smooth ullage pressurization rates are predicted. This work advances current low gravity CFD modeling capabilities for cryogenic pressure control and aids the development of a low cost CFD-based design process for space hardware

The Importance of Detailed Component Simulations in the Feedsystem Development for a Two-Stage-to Orbit Reusable Launch Vehicle

To meet the requirements for the 2nd Generation Reusable Launch Vehicle (RLV), a unique propulsion feed system concept was identified using crossfeed between the booster and orbiter stages that could reduce the Two-Stage-to-Orbit (TSTO) vehicle weight and development cost by approximately 25%. A Main Propulsion System (MPS) crossfeed water demonstration test program was configured to address all the activities required to reduce the risks for the MPS crossfeed system. A transient, one-dimensional system simulation was developed for the subscale crossfeed water flow tests. To ensure accurate representation of the crossfeed valve's dynamics in the system model, a high-fidelity, three-dimensional, computational fluid-dynamics (CFD) model was employed. The results from the CFD model were used to specify the valve's flow characteristics in the system simulation. This yielded a crossfeed system model that was anchored to the specific valve hardware and achieved good agreement with the measured test data. These results allowed the transient models to be correlated and validated and used for full scale mission predictions. The full scale model simulations indicate crossfeed is ' viable with the system pressure disturbances at the crossfeed transition being less than experienced by the propulsion system during engine start and shutdown transients