Computer simulation program is adaptable to industrial processes

The Reaction kinetics ablation program /REKAP/, developed to simulate ablation of various materials, provides mathematical formulations for computer programs which can simulate certain industrial processes. The programs are based on the use of nonsymmetrical difference equations that are employed to solve complex partial differential equation systems

Detonation Diffraction Through a Mixture Gradient

A simple one-dimensional model of a self-propagating gaseous detonation consists of a shock wave tightly coupled to a reaction zone, propagating through a combustible gas mixture as shown in Fig. 1 (Strehlow 1984). A feedback mechanism exists in that the shock wave generates the thermodynamic conditions under which the gas combusts, and the energy release from the reaction zone maintains the strength of the shock This is in contrast to a flame, or deflagrative combustion, in which thermal and species transport processes dominate. Given a particular set of initial conditions, a self-propagating detonation wave travels at a constant Chapman-Jouguet velocity (VCJ) on the order of a few thousand meters per second, with associated pressures and temperatures of tens of bar and several thousand degrees, respectively. A detonation is actually a three-dimensional shock-reaction zone complex with a dynamic wavefront composed of curved incident, mach stem, and transverse shock waves as depicted in Fig. 2 (Strehlow 1970). The transverse shocks sweep across the wavefront and the triple-point paths form a diamond-shaped cellular pattern. The cell width [Greek lambda] is a characteristic length scale of detonations, indicative of the coupling between gasdynamic and chemical processes

Investigation of the effect of material properties on composite ablative material behavior Third quarterly report, Dec. 11, 1965 - Mar. 10, 1966

Effects of processing and fabrication techniques on properties of composite ablative material

Structures and proton-pumping strategies of mitochondrial respiratory enzymes

Enzymes of the mitochondrial respiratory chain serve as proton pumps, using the energy made available from electron transfer reactions to transport protons across the inner mitochondrial membrane and create an electrochemical gradient used for the production of ATP. The ATP synthase enzyme is reversible and can also serve as a proton pump by coupling ATP hydrolysis to proton translocation. Each of the respiratory enzymes uses a different strategy for performing proton pumping. In this work, the strategies are described and the structural bases for the action of these proteins are discussed in light of recent crystal structures of several respiratory enzymes. The mechanisms and efficiency of proton translocation are also analyzed in terms of the thermodynamics of the substrate transformations catalyzed by these enzymes

Modification of the one-dimensional REKAP program to allow for charring in three material layers Final report

Modified one-dimensional reaction kinetics program to allow for charring in three material layers of rocket nozzle throat insert cas

Evaluation of Urban Polder Drainage System performance in Jakarta. Case Study Kelapa gading Area

Kelapa Gading area is located in the plains of North Jakarta about 6 km from the coastline of Jakarta Bay. Kelapa Gading area covers 1288 ha it consists of three large compartments and next to that the Kodamar Unit separated system from Kelapa Gading excess water of the area is discharged to Sunter river and Pertukangan River. The area is regularly flooded, especially during the wet season. Kelapa Gading area is in particular facing flood problem since Jakarta __ the capital city of Indonesia __ became the primary growth machine of the nation. Among others, this has resulted in suburbanization in Jakarta’s neighbouring regions. Land subsidence, which occurs due to huge groundwater extraction, and climate change are also contributing to flooding problem due to hydrologic changes that alter the magnitude and frequency of peak flows and sea level rise. Four main objectives are the basis for this research. First is describing the existing urban drainage and flood protection systems in Kelapa Gading area and other satellite cities (JABODETABEK). Second is analysing the possible impacts of land subsidence and sea level rise on inundated area. Next are some measures that would have to be taken into consideration in order to reduce the flooded area and provide adequate urban drainage and flood protection especially when the impacts of land subsidence and sea level rise are taken into account. The structural measures were studied by considering hydrologic and hydraulic conditions and by carrying out hydrodynamic modelling (DUFLOW) as tools for decision support which may evaluate options in developing urban drainage and flood protection scenarios for Kelapa Gading area based on a design rainfall with a chance of occurrence of 4% per year or the return period of 25 years. Scenarios on the improvement of the macro urban drainage system and the selected river basin were developed as follows: Scenario 1. The existing urban drainage was considered as one system with the sedimentation in the urban canal system. This represents the existing condition and has been used as the basic case; Scenario 2. Similar with the first scenario 1 but the designed urban canal profiles are used; Scenario 3. Each compartment is considered as a single polder; Scenario 4. To analyse the effect of land subsidence and sea level rise. In this case 1.25 m of land subsidence and 0.15 m of sea level rise will be considered for the 25 years time interval; The results indicate that due to lower topographic conditions in adjacent area caused by land subsidence and sea level rise, a combine system consisting of gravity drainage and pumping are primed to meet the future conditions of drainage system and flood protection in the future in Kelapa Gading area. Therefore an urban polder with its properties is proposed to be constructed

On-line digital computer control of the NERVA nuclear rocket engine

The problem of on-line digital computer control of the NERVA nuclear rocket engine is considered. Proposed is a method of State Dependent State Variable Feedback (SDSVF) as a practical approach to the control of NERVA and other complex nonlinear and/or time-varying systems. The difficulties inherent in other design methods are avoided by defining the optimal closed loop system in terms of a desired transfer function, rather than a performance index to maximize or minimize

Seismic effects from major basin formation on the Moon and Mercury

Grooved and hilly terrains are reported which occur at the antipode of major basins on the Moon (Imbrium, Orientale) and Mercury (Caloris). Order-of-magnitude calculations, for an Imbrium-size impact on the Moon, indicate P-wave-induced surface displacements of 10 m at the basin antipode that would arrive prior to secondary ejecta. Comparable surface waves are reported which would arrive subsequent to secondary ejecta impacts and would increase in magnitude as they converge at the antipode. Other seismically induced surface features include: subdued, furrowed crater walls produced by landslides and concomitant secondary impacts; emplacement and leveling of light plains units owing to seismically induced "fluidization" of slide material; knobby, pitted terrain around old basins from enhancement of seismic waves in ancient ejecta blankets; and the production and enhancement of deep-seated fractures that led to the concentration of farside lunar maria in the Apollo-Ingenii region