As a CAD tool, the Computer Aided Model Structuring System (call MOSTS in the following text) for model structuring in system design and system simulation has been designed and implemented. First, this MOSTS allows system design experts to create and save System Data Bases (SDBs) for model structuring in system design and simulation. Then, these SDBs can be retrieved, modified, and finally used to structure system models by design engineers. The MOSTS pursues the model structuring process in such a way that the model structure having the best performance (according to the expert's knowledge and the design engineer's design criteria) will be generated first, and then the second best model, the third best model, and so on.

Many conceptual models have been proposed to explain the fluid-flow mechanism responsible for the origin of carbonate-hosted lead-zinc deposits such as those in the Mississippi Valley and at Pine Point. This study is devoted to the quantitative investigation of one ore-genesis mechanism gravity-driven groundwater-flow systemso Numerical modeling techniques are used to develop a self-contained computer code for two-dimensional simulation of regional transport processes along cross sections through sedimentary basins. The finite-element method is applied to solve the steady-state, fluid-flow and heat-transport equations, and a movin6-particle random-walk model is developed to predict the dispersion and advection of aqueous components. The program EQ3/EQ6 is used to compute possible reaction-path scenarios at the ore-forming site. Full integration of geochemical calculations into the transport model is currently impractical because of computer-time limitations. Results of a sensitivity analysis indicate that gravity-driven ground water-flow systems are capable of sustaining favorable fluid-flow rates, temperatures, and metal concentrations for ore formation near the thin edge of a basin. Dispersive processes render long-distance transport of metal and sulfide in the same fluid an unlikely process in the genesis of large ore deposits, unless metal and sulfide are being added to the fluid along the flow path. The transport of metal in sulfate-type brines is a more defensible model, in which case the presence of reducing agents control the location of ore deposition. Hydrodynamic conditions that could result in ore formation through mixing of two fluids are rare. The theoretical approach is a powerful tool for gaining insight into the role of fluid flow in ore genesis and in the study of specific ore districts. A preliminary model of the Pine Point deposit suggests paleoflow rates on the order of 1.0 to 5.0 m3/m2 yr, paleoconcentrations of zinc on the order of 1.0 to 5.0 mg/kg• H 2 O, and paleotemperatures in the range 60°C to 100°c. Under these conditions, the time required for the formation of Pine Point would be on the order of 0.5 to 5.0 million years.

Particle size distribution (PSD) plays a key role in fluidization behavior. The effect of PSD in fluidized, gas-solid mixtures is elucidated by considering two types of bimodal particle mixtures. In the first case, a mixture of "large" particles, which engage in particle-particle collisions, and "small" particles or fines, which follow the fluid streamlines, are considered. In this case, one net effect of the fines is to decrease the pressure drop required to convey a given solids flux in a riser. In the second case, a mixture of two sizes of larger particles in which collisions between like and unlike particles occur are considered. In this case, a reduction in particle phase stress in the bimodal mixture as compared to a monosized particle mixture with the same mean particle diameter is predicted. For dilute flow, this stress reduction is minimal but increases in significance as the suspension becomes more concentrated.

This study examined the nutritional patterns of 26 preadolescents (7-10 years of age) who participated in a summer food service program and determined whether the program met one-third of their daily nutrient intake. Visual plate waste and 24-hour dietary recalls were taken on five days at three ethnically different sites. Food consumed at lunch provided more than one-third of total intake for all nutrients studied, with the exception of carbohydrate intake in girls, and carbohydrate, iron and thiamine intake in boys. Average amount of food consumed at lunch by participants exceeded one-third of the RDA for all nutrients except Kcalories and iron. Additionally, mean total Kcalories consumed over a 24-hour period by participants met only 66 percent of the RDA.

The Mogul fault is a strand of the Texas lineament. The Margaret Wash section of the fault is 27 air-line miles north-northeast of Tucson near the north end of the Santa Catalina Mountains0 Attitudes were measured on bedding and foliation in a long narrow belt of Pinal schist which has been in part deformed by movements on the Mogul fault. At the east end of the belt the bedding strikes northeast and dips northwest, however, at the west end of the belt bedding and gneissic foliation strike west-northwest and dip south- southwest. The writer interprets the internal structure of the Pinal schist as reflecting left lateral strike slip in a fault zone which includes the west end of the schist belt but lies to the north of the east end. The age and amount of strike slip are unknown. Later normal faulting which is probably Cenozoic cuts obliquely (more northwest) across the strike slip oriented schist. The normal fault dips steeply to the south and the maximum dip slip is probably a few hundred feet.

Prehistoric and traditional ceramics contain a wide range of tempers (non-plastic inclusions), including sand, sherd (grog), sponge spicules, phytoliths (siliceous bark ash), diatomite, organic fibers, shell, calcite, mica and asbestos. The use of these materials in traditional and archaeological ceramics and their association with cooking pottery and thermal shock resistance are examined. The thermal shock parameters that are relevant to low-fired ceramics are identified and tested. The primary factor in the thermal shock resistance is identified as fracture toughness. By increasing the amount and size range of temper additions, and by selecting tempers that are platy and fibrous, fracture toughness can be enhanced. Secondary factors include porosity, thermal expansion and relative strength. These parameters are tested employing fracture energy and thermal expansion measurements, and quench tests.